FN ISI Export Format VR 1.0 PT J AU Alvarez-Cadena, JN Ordonez-Lopez, U Almaral-Mendivil, AR Ornelas-Roa, M Uicab-Sabido, A AF Alvarez-Cadena, Jose N. Ordonez-Lopez, Uriel Rosa Almaral-Mendivil, Alma Ornelas-Roa, Margarita Uicab-Sabido, Amira TI Fish larvae from the north littoral reef of Quintana Roo, Mexican Caribbean SO HIDROBIOLOGICA LA Spanish DT Article DE fish larvae; Mexican Caribbean sea ID GREAT-BARRIER-REEF; ASSEMBLAGES; LAGOON; ISLAND AB Neuston samples (144) collected monthly from January to December 2004 from the north of the Mexican Caribbean Sea were analyzed. Trawlings were made at twelve sites along the coast, from Puerto Morelos to Cancun with a neuston net (0.60X 0.80 m; mesh 330 mu) for 10 min., near surface. Salinity (spu), temperature (degrees C), and Oxygen (mg/l), were measured in situ, allowing the characterization of two climatic regimes: dry and wet season, and three environments: coastal (with oceanic characteristics), lagoon, and reef areas. A total of 5,577 fish larvae were captured (4,398.5 larvae/100 m(3)) corresponding to 55 families and 115 taxa. Gobies were the most conspicuous taxa, they were found in all three environments and ratify previous reports by other workers. Ctenogobius sp. (26.6%), Gobionellus sp.1 (17.9%), and Harengula jaguana (6.7%), made up more than 51%. Seasonally, highest average abundance was recorded in the dry season (56.9%) peaking in March (9.1 +/- 4.5 larvae/100 m(3)), The lagoon environment contained the lowest species richness (44) than the coastal (78) or reef (82) areas, but more larvae were caught (2,865.6 larvas/100 m(3)), a number higher than those collected at the other two environments put together. C1 Univ Nacl Autonoma Mexico, Inst Ciencias Mar & Limnol, Unidad Acad Puerto Morelos, Cancun 77501, Quintana Roo, Mexico. Inst Politecn Nacl, Ctr Invest & Estud Avanzados, Unidad Merida, Cordemex 97310, Mexico. RP Alvarez-Cadena, JN, Univ Nacl Autonoma Mexico, Inst Ciencias Mar & Limnol, Unidad Acad Puerto Morelos, Apartado Postal 1152, Cancun 77501, Quintana Roo, Mexico. EM nac@mar.icmyl.unam.mx CR *COMM NAC AG, 2004, 6 FOR PRED CLIM REP *I GEOFISICA, 1991, TABLAS PREDICCION MA ALVAREZCADENA JN, 1996, B MAR SCI, V58, P694 ALVAREZCADENA JN, 1996, GULF RES REP, V9, P97 FAHAY MP, 1983, J NW ATLANTIC FISHER, V4 FLORESCOTO C, 1980, AN CTR CIENC MAR LIM, V7, P67 FROESE R, 2006, FISHBASE HOUDE ED, 1993, B MAR SCI, V53, P290 LEIS JM, 1987, AUST J MAR FRESH RES, V38, P211 LEIS JM, 1991, B MAR SCI, V48, P150 LEIS JM, 1993, B MAR SCI, V53, P362 LONGHURST AR, 1987, ECOLOGY TROPICAL OCE MCCUNE B, 2002, ANAL ECOLOGICAL COMM MERINO M, 1986, AN I CIENC MAR LIMNO, V13, P31 MERINO M, 1990, ESTUAR COAST SHELF S, V30, P223 MERINO M, 1991, ATLAS AMBIENTAL COST MOSER HG, 1984, ONTOGENY SYSTEMATIC, V1 RICHARDS WJ, 2006, EARLY STAGES ATLANTI, P1 ROBINS CR, 1991, BIOSCIENCE, V41, P458 SANCHEZVELASCO L, 1994, SCI MAR, V58, P289 SANVICENTEANORVE L, 1999, REV BIOL TROP S1, V47, P175 SCHMITTERSOTO JJ, 2000, SERIE ZOOLOGIA, V71, P143 SMITH PE, 1977, 175 FAO STRICKLAND JDH, 1972, PARTICAL HDB SEA WAT THOMSON RE, 1984, J MAR RES, V42, P787 VASQUEZ L, 1992, DIVERSIDAD BIOL RESE, V2, P287 VASQUEZYEOMANS L, 1990, DIVERSIDAD BIOL RESE, P321 VASQUEZYEOMANS L, 1998, B MAR SCI, V62, P229 VASQUEZYEOMANS L, 2003, B MAR SCI, V73, P141 ZAR JH, 1988, BIOSTATISTICAL ANAL NR 30 TC 0 PU UNIV AUTONOMA METROPOLITANA-IZTAPALAPA PI MEXICO PA SAN RAFAEL ATLIXCO NO 186, COL VICENTINA, DELEGACION IZTAPALAPA, MEXICO, 09340, MEXICO SN 0188-8897 J9 HIDROBIOLOGICA JI Hidrobiologica PD AUG PY 2007 VL 17 IS 2 BP 139 EP 150 PG 12 GA 217LI UT ISI:000249949000006 ER PT J AU Trujillo-Jimenez, P Beto, HT AF Trujillo-Jimenez, Patricia Beto, Hector Toledo TI Diet of the tropical freshwater fish Heterandria bimaculata (Haeckel) and Poecilia sphenops Valenciennes (Cyprinidontiformes : Poeciliidae) SO REVISTA DE BIOLOGIA TROPICAL LA Spanish DT Article DE diet; food habits; Heterandria bimaculata; Poecilia sphenops; "Los carros"; Morelos; Mexico ID OCCIDENTALIS; COMPETITION; FLORIDA; HABITS; STREAM AB We analyzed the diet and feeding habits of the fishes Heterandria bimaculata and Poecilia sphenops. Specimens were captured monthly in "Los Carros" damp, Morelos, Mexico (18 degrees 37' N, 98 degrees 43' W). We quantified gut content by the numerical method and by the frequency of occurrence method; and used the MacArthur and Levin's indices for niche overlap. The diet of H. bimaculata was composed by 16 prey categories. mainly dipterans (Culicidae predominated), independently of sex, size and season. The index of niche overlap was high, from 0.74 to 0.99. The diet of P. sphenops consisted of I I items, detritus being the most consumed, also independently of sex, size and season, The niche overlap index was high (0.99), indicating overlapping for all analyses. There was little diet overlap (0.26) between the two species. C1 Univ Autonoma Estado Morelos, Biol Res Ctr, Cuernavaca 62210, Morelos, Mexico. RP Trujillo-Jimenez, P, Univ Autonoma Estado Morelos, Biol Res Ctr, Av Univ 1001 Col Chamilpa, Cuernavaca 62210, Morelos, Mexico. EM trujill@cib.uaem.mx CR ALAYO P, 1973, TORRCIA NUEVA SERIE, V29, P1 BARRINGTON EJW, 1957, FISH PHYSL ACAD, P109 BLAND RG, 1979, KNOW INSECTS CHU HF, 1979, KNOW INMATURE INSECT DELVILLAR A, 1970, MEXICO SERIE INVESTI DUARTE SMP, 1981, THESIS I POLITECNICO GERKING DS, 1994, FEEDING ECOLOGY FISH GREENFIELD DW, 1983, COPEIA, P598 GREENFIELD DW, 1983, FIELDIANA ZOOL, V14, P1 HARRINGTON RW, 1961, ECOLOGY, V42, P649 HARRINGTON RW, 1982, B MAR SCI, V32, P523 HESS AD, 1942, AM J HYG, V35, P142 KREBS JC, 1999, ECOLOGICAL METHODOLO LAGLER KF, 1956, FRESHWATER FISHERY B MACHADOALLISON A, 1987, PECES ILANOS VENEZUE MAGALLONBARAJAS S, 1992, U CIENC TECNOL, V2, P121 MARTINEZ TM, 1989, BIOL UMSNH MEXICO, V2, P49 MEFFE G, 1989, ECOLOGY EVOLUTION LI MEFFE GK, 1983, BIOL CONSERV, V25, P135 MEFFE GK, 1984, SW NATURALIST, V29, P500 MERRIT WR, 1996, INTRO AQUATIC INSECT MILEY WW, 1978, THESIS U FLORIDA FLO MOYLE BP, 1988, FISHES INTRO ICHTHYO NEEDHAM JG, 1978, GUIA ESTUDIO SERES V NIKOLSKII GV, 1969, THEORY FISH POPULATI ORTAZ M, 1992, BIOTROPICA, V24, P550 ORTAZ M, 2001, REV BIOL TROP, V49, P191 PAREDES LME, 1998, THESIS U AUTONOMA ES PARENTI RL, 1989, ECOLOGY EVOLUTION LI, P3 PENNAK K, 1978, FRESHWATER INVERTEBR SATO H, 1989, JAPANESE J TROP MED, V2, P157 SCHOENER TW, 1982, AM SCI, V70, P586 SCHOENHERR AA, 1981, FISHES N AM DESERTS, P173 SIEGEL S, 1976, ESTADISTICA PARAMETR SUAREZ TSL, 2002, AVACIENT, V33, P56 TORRENTE A, 1993, MEMORIAS I OSWALDO C, V4, P625 TRUJILLO JP, 1998, THESIS U NACL AUTONO TRUJILLOJIMENEZ P, 1996, MEXICO REV BIOL TROP, V44, P755 TURNER JS, 1984, ENVIRON BIOL FISH, V10, P89 VRIJENHOEK RC, 1974, EVOLUTION, V28, P306 WETZEL RL, 1971, THESIS U W FLORIDA P WIKRAMANAYAKE DE, 1990, ECOLOGY, V7, P1756 WINDELL JT, 1978, METHODS ASSESSMENT F, P219 WOOTON RJ, 1991, ECOLOGY TELEOST FISH WOOTTON RJ, 1992, FISH ECOLOGY ZARET TM, 1971, ECOLOGY, V52, P336 NR 46 TC 0 PU REVISTA DE BIOLOGIA TROPICAL PI SAN JOSE PA UNIVERSIDAD DE COSTA RICA CIUDAD UNIVERSITARIA, SAN JOSE, COSTA RICA SN 0034-7744 J9 REV BIOL TROP JI Rev. Biol. Trop. PD JUN PY 2007 VL 55 IS 2 BP 603 EP 615 PG 13 SC Biology GA 218KB UT ISI:000250013300021 ER PT J AU Hernandez-Uribe, JP Agama-Acevedo, E Islas-Hernandez, JJ Tovar, J Bello-Perez, LA AF Hernandez-Uribe, Juan Pablo Agama-Acevedo, Edith Islas-Hernandez, Jose Juan Tovar, Juscelino Bello-Perez, Luis A. TI Chemical composition and in vitro starch digestibility of pigmented corn tortilla SO JOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE LA English DT Article DE tortilla; pigmented maize; chemical composition; starch digestibility; glycemic index ID RESISTANT STARCH; ALKALINE COOKING; STORAGE TIME; DIGESTION; FOODS; ANTHOCYANINS; MASA AB BACKGROUND: Tortillas were prepared from two (blue and regular white) maize varieties and compared with regard to chemical composition and in vitro starch digestibility, i.e., available starch (AS), total (RS) and retrograde (RRS) resistant starch contents, amylolysis rate and predicted glycemic index (pGI). The impact of cold storage (4 degrees C) on digestibility was also investigated. RESULTS: Despite its higher protein and lipid contents, pigmented tortilla exhibited lower AS content than the white product. AS in both types of tortilla decreased during the first 2 days of storage, and remained stable thereafter. Blue tortilla had lower RS content (21 g kg(-1) dry matter basis) than the white tortilla (30 g kg(-1) dry matter basis). RS values were slightly higher in 2 day-stored tortillas than in their fresh counterparts. Although the RRS content in recently made white tortillas was greater than in the colored preparation, stored blue tortillas exhibited double RRS values compared with freshly baked samples. alpha-Amylolysis of blue tortilla was slower than in the white sample. Consequently, blue tortilla exhibited a lower pGI value. pGI for the white tortilla decreased upon cold storage, a change that was not be observed for the colored preparation. CONCLUSION: Starch digestibility characteristics of blue tortilla make it suitable for people with special nutritional or metabolic requirements. (C) 2007 Society of Chemical Industry. C1 IPN, Ctr Desarrollo Prod Biot, Yautepec 62731, Morelos, Mexico. Cent Univ Venezuela, Fac Ciencias, Inst Expt Biol, Caracas, Venezuela. RP Bello-Perez, LA, IPN, Ctr Desarrollo Prod Biot, Km 8-5 Carr,Yautepec Jojutla,Colonia San Isidro,A, Yautepec 62731, Morelos, Mexico. EM labellop@ipn.mx CR *AACC, 2000, APPROVED METHODS AAC AGAMAACEVEDO E, 2004, NAHRUNG, V48, P38 AGAMAACEVEDO E, 2005, ARCH LATINOAM NUTR, V55, P86 ASP NG, 1992, EUR J CLIN NUTR S2, V46, S1 BELLOPEREZ LA, 2006, CEREAL CHEM, V83, P188 BILIADERIS CG, 1991, CAN J PHYSIOL PHARM, V69, P60 BJORCK I, 1994, AM J CLIN NUTR, V59, S699 CAMPASBAYPOLI ON, 1999, STARCH-STARKE, V5, P173 CAMPASBAYPOLI ON, 2002, STARCH-STARKE, V54, P358 CORTESGOMEZ A, 2005, J FOOD ENG, V66, P273 DELATORRE RRR, 1986, THESIS MEXICO ENGLYST HN, 1992, EUR J CLIN NUTR S2, V46, P33 GONI I, 1996, FOOD CHEM, V56, P445 GONI I, 1997, NUTR RES, V17, P427 HOLM J, 1986, STARCH-STARKE, V38, P224 HOLMES CA, 1993, SCHOLARLY INQUIRY NU, V7, P3 LEE TH, 1997, MECHATRONICS, V7, P83 MORENO YS, 2000, ANTOCIANINAS GRANOS ORTEGA RA, 1991, ESTUDIO RECURSOS FIT, P161 RANGELMEZA E, 2004, AGROCIENCIA-MEXICO, V38, P53 RENDONVILLALOBOS R, 2002, CEREAL CHEM, V79, P340 SALINASMORENO Y, 2003, AGROCIENCIA-MEXICO, V37, P617 SAURACALIXTO F, 1993, J FOOD SCI, V58, P642 STAVRIC B, 1994, FOOD CHEM TOXICOL, V32, P79 TOVAR J, 1992, J NUTR, V122, P1500 TOVAR J, 2001, FIBRA DIETETICA IBER, P143 WANG H, 1997, J AGR FOOD CHEM, V45, P304 WELLHAUSEN EJ, 1951, XOLOCOTZIA OBRAS EFR, P609 YUAN RC, 1993, CEREAL CHEM, V70, P81 NR 29 TC 0 PU JOHN WILEY & SONS LTD PI CHICHESTER PA THE ATRIUM, SOUTHERN GATE, CHICHESTER PO19 8SQ, W SUSSEX, ENGLAND SN 0022-5142 J9 J SCI FOOD AGR JI J. Sci. Food Agric. PD OCT PY 2007 VL 87 IS 13 BP 2482 EP 2487 PG 6 SC Agriculture, Multidisciplinary; Chemistry, Applied; Food Science & Technology GA 220MS UT ISI:000250161400014 ER PT J AU Calogero, F Leyvraz, F AF Calogero, F. Leyvraz, F. TI General technique to produce isochronous Hamiltonians SO JOURNAL OF PHYSICS A-MATHEMATICAL AND THEORETICAL LA English DT Article AB We introduce a new technique-characterized by an arbitrary positive constant Omega, with which we associate the period T = 2 pi/Omega-to 'Omega-modify' a Hamiltonian so that the new Hamiltonian thereby obtained is entirely isochronous, namely it yields motions all of which (except possibly for a lower dimensional set of singular motions) are periodic with the same fixed period T in all their degrees of freedom. This technique transforms real autonomous Hamiltonians into Omega-modified Hamiltonians which are also real and autonomous, and it is widely applicable, for instance, to the most general many-body problem characterized by Newtonian equations of motion ('acceleration equal force') provided it is translation invariant. The Omega-modified Hamiltonians are of course not translation invariant, but for Omega = 0 they reduce (up to marginal changes) to the unmodified Hamiltonians they were obtained from. Hence, when this technique is applied to translation-invariant Hamiltonians yielding, in their center-of-mass systems, chaotic motions with a natural time scale much smaller than T, the corresponding Omega-modified Hamiltonians shall display a chaotic behavior for quite some time before the isochronous character of the motions takes over. We moreover show that the quantized versions of these Omega-modified Hamiltonians feature equispaced spectra. C1 Univ Roma La Sapienza, Dipartimento Fis, Rome, Italy. Ist Nazl Fis Nucl, Sez Roma, Rome, Italy. UNAM, Inst Ciencias Fis, Cuernavaca, Morelos, Mexico. Ctr Int Ciencias, Cuernavaca, Morelos, Mexico. RP Calogero, F, Univ Roma La Sapienza, Dipartimento Fis, Rome, Italy. EM francesco.calogero@uniroma1.it leyvraz@fis.unam.mx CR CALOGERO F, 1997, J MATH PHYS, V38, P5711 CALOGERO F, 2002, J PHYS A, V35, P10365 CALOGERO F, 2006, ENCY MATH PHYS, V3, P166 CALOGERO F, 2006, J MATH PHYS, V47, P1 CALOGERO F, 2006, J PHYS A-MATH GEN, V39, P11803 CALOGERO F, 2007, IN PRESS J MATH PHYS CALOGERO F, 2008, ISOCHRONOUS SYSTEMS SCHUTZ BF, 1985, 1 COURSE GEN RELATIV NR 8 TC 0 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 1751-8113 J9 J PHYS A-MATH THEOR JI J. Phys. A-Math. Theor. PD OCT 26 PY 2007 VL 40 IS 43 BP 12931 EP 12944 PG 14 SC Physics, Multidisciplinary; Physics, Mathematical GA 220GZ UT ISI:000250146500010 ER PT J AU Jimenez-Cruz, F Hernandez, JA Laredo, GC Mares-Gallardo, MT Garcia-Gutierrez, JL AF Jimenez-Cruz, Federico Hernandez, J. A. Laredo, Georgina C. Mares-Gallardo, Maria Teresa Garcia-Gutierrez, Jose Luis TI Adsorption of n-heptane and 2-methylheptane in the gas phase on polyvinylidene chloride-based microporous activated carbon SO ENERGY & FUELS LA English DT Article ID CH/PI-INTERACTION; MOLECULAR-SIEVE; ALKANES; SARAN; ZEOLITES; MAGNITUDE; CHEMISTRY; BENZENE; SURFACE; ZSM-22 AB The selective adsorption of n-heptane and 2-methylheptane was tested on polyvinylidene chloride-based microporous carbon (CMS-IMP12) prepared from pyrolysis of poly(vinylidene chloride-co-vinyl chloride) (PVDC-PVC) copolymer. CMS-IMP12 was characterized by textural analysis, scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), and Fourier transform infrared (FTIR) and Raman spectroscopies. These results indicate the presence of graphene subunits inside the amorphous carbon and great quantity of sp 2 carbon type in CMS-IMP12. It was found that 2-methylbeptane is better adsorbed than n-heptane on the carbon sample by an inverse gas chromatography (IGC) adsorption study at 275-350 degrees C. Structural features of the carbonaceous material, entropy restrictions by steric parameters, diffusion conditions, and cooperative CH/pi interactions between CH in n-heptane and 2-methylheptane and pi electrons in the carbon walls determine the selective adsorption. C1 Inst Mexicano Petr, Programa Invest Proc & Reactores, Mexico City 07730, DF, Mexico. Univ Autonoma Estado Morelos, Ctr Invest Ingn & Ciencias Aplicadas, Cuernavaca 62210, Morelos, Mexico. RP Jimenez-Cruz, F, Inst Mexicano Petr, Programa Invest Proc & Reactores, Eje Cent Lazaro Cardenas 152,Col San Bartolo A, Mexico City 07730, DF, Mexico. EM jimenezf@imp.mx CR ARIK IC, 2003, MICROPOR MESOPOR MAT, V60, P111 ATKINSON D, 1979, J CHEM EDUC, V56, P802 BARTON SS, 1974, J COLLOID INTERF SCI, V49, P462 BROUGHTON DB, 1968, CHEM ENGNG PROGR, V64, P60 CALERO S, 2001, PHYS CHEM CHEM PHYS, V3, P4390 CONDER JR, 1979, PHYSICOCHEMICAL MEAS DEMUTH H, 2000, OPTIMIZATION TOOLBOX DENAYER JF, 1998, J PHYS CHEM B, V102, P4588 DENAYER JF, 2003, CHEM COMMUN, P1880 DO DD, 1998, ADSORPTION ANAL EQUI ENDO M, 2001, J ELECTROCHEM SOC, V148, S1135 ENDO M, 2002, J ELECTROCHEM SOC, V149, A1473 FERNANDEZMORALE.I, 1984, CARBON, V22, P301 HSIEH TH, 1999, J POLYM SCI POL CHEM, V37, P3269 JIMENEZCRUZ F, 2004, FUEL, V83, P2183 KISELEV AV, 1969, GAS ADSORPTION CHROM, P104 KITAGAWA H, 1981, CARBON, V19, P470 LAMOND TG, 1965, CARBON, V3, P59 LIPPENS BC, 1965, J CATAL, V4, P319 MONTESMORAN MA, 2002, J COLLOID INTERF SCI, V247, P290 MORENOCASTILLA C, 2000, CARBON, V38, P1995 NAKAI K, 1993, PURE APPL CHEM, V65, P2181 NISHIO M, 1989, TETRAHEDRON, V45, P7201 NISHIO M, 1998, CH PIE INTERACTION PIERCE C, 1949, J PHYS CHEM-US, V53, P669 POOLE CP, 2003, INTRO NANOTECHNOLOGY, P207 RAGIL K, 2002, 6338791, US RUTHVEN DM, 1984, PRINCIPLES ADSORPPTI SADEZKY A, 2005, CARBON, V43, P1731 SHIBASAKI K, 2006, J PHYS CHEM A, V110, P4397 STARSINIC M, 1983, CARBON, V21, P69 SUZUKI M, 1990, ADSORPTION ENG TSUZUKI S, 2000, J AM CHEM SOC, V122, P3746 UMEZAWA Y, 1999, TETRAHEDRON, V55, P10047 WANKAT PC, 1986, LARGE SCALE ADSORPTI WEBB EB, 1999, J PHYS CHEM B, V103, P4949 ZAWADZKI J, 1989, INFRARED SPECTROSCOP, V21 NR 37 TC 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0887-0624 J9 ENERG FUEL JI Energy Fuels PD SEP-OCT PY 2007 VL 21 IS 5 BP 2929 EP 2934 PG 6 SC Energy & Fuels; Engineering, Chemical GA 212PC UT ISI:000249608300057 ER PT J AU Heyd, B Broyart, B Hernandez, JA Valdovinos-Tijerino, B Trystram, G AF Heyd, B. Broyart, B. Hernandez, J. A. Valdovinos-Tijerino, B. Trystram, G. TI Physical model of heat and mass transfer in a spouted bed coffee roaster SO DRYING TECHNOLOGY LA English DT Article DE drying; modeling; roasting coffee AB A key step in coffee processing is roasting, where green coffee beans are heated at high temperatures ( over 190 degrees C), initiating a series of complex chemical reactions. This process can be divided in two phases ( drying < 160 degrees C and roasting > 160 degrees C). Therefore, the quality of coffee is highly correlated with bean temperature during roasting. The aim of this work is to measure and model coffee bean temperature and moisture content during the roasting process, in order to determine on-line quality of the product allowing the control of the process. A spouted bed roaster, using hot air flow as heating medium, was developed. The surface and center bean temperature, as well as input and output air temperatures, were measured on-line. At each minute interval of roasting, samples of coffee beans were taken to measure the moisture content. A dynamical model, which takes in account heat and mass transfer at the surface and inside of the beans, is proposed. This model, where only the water diffusivity in the bean was adjusted, gave a good prediction of bean temperature (center and surface), average moisture content, and output air temperature for all the experiments. However, in the industry, only the output air temperature can be measured. Consequently, this model could assist in on-line determination of the bean temperature and hence constitutes the first stage in developing a smart sensor for on-line checking including quality control. C1 INRA, Dept GIA, ENSIA,INAPG, Joint Res Unit Food Proc Engn, F-91744 Massy, France. Univ Autonoma Estado Morelos, Res Ctr Engn & Appl Sci, Cuernavaca, Morelos, Mexico. RP Heyd, B, INRA, Dept GIA, ENSIA,INAPG, Joint Res Unit Food Proc Engn, 1,Ave Des Olympiades, F-91744 Massy, France. EM heyd@ensia.fr CR *AFNOR, 1976, NF V03 310 V03 311 BIRD RB, 1960, TRANSPORT PHENOMENA CHANDRASEKAR V, 1999, J AGR ENG RES, V73, P227 GUPTA, 1999, PERRYS CHEM ENG HDB, P5 HERNANDEZ JA, 2002, THESIS ECOLE NATL SU HERNANDEZ JA, 2007, J FOOD ENG, V78, P1141 IGLESIAS H, 1982, HDB FOOD ISOTHERMS W NADEAU A, 1995, SECHAGE PROCESSUS PH OZISIK MN, 1994, FINITE DIFFERNECE ME, P126 RANKINE WJM, 1859, MANUAL STEAM ENGINE SCHWARTZBERG HG, 2000, ENG FOOD 21 CENTURY, P871 SHAMPINE LF, 1997, SIAM J SCI COMPUT, V18, P1 TRELEA IC, 1997, DRY TECHNOL, V15, P1095 NR 13 TC 0 PU TAYLOR & FRANCIS INC PI PHILADELPHIA PA 325 CHESTNUT ST, SUITE 800, PHILADELPHIA, PA 19106 USA SN 0737-3937 J9 DRY TECHNOL JI Dry. Technol. PY 2007 VL 25 IS 7-8 BP 1243 EP 1248 PG 6 SC Engineering, Chemical; Engineering, Mechanical GA 216HF UT ISI:000249868400012 ER PT J AU Avila-Fernandez, A Olvera-Carranza, C Rudino-Pinera, E Cassab, GI Nieto-Sotelo, J Lopez-Munguia, A AF Avila-Fernandez, Angela Olvera-Carranza, Clarita Rudino-Pinera, Enrique Cassab, Gladys Iliana Nieto-Sotelo, Jorge Lopez-Munguia, Agustin TI Molecular characterization of sucrose: sucrose 1-fructosyltransferase (1-SST) from Agave tequilana Weber var. azul. SO PLANT SCIENCE LA English DT Article DE agave; fructan; fructooligosaccharides; 1-Kestose; 1-SST ID CICHORIUM-INTYBUS; FRUCTAN 6-FRUCTOSYLTRANSFERASE; HELIANTHUS-TUBEROSUS; KEY ENZYME; PURIFICATION; EXPRESSION; CLONING; CHICORY; INULIN; FRUCTOSYLTRANSFERASES AB A full-length cDNA encoding for I-SST in Agave tequilana Weber var. azul. was isolated, cloned and expressed in Pichia pastoris. The heterologous protein, with a molecular mass of 75 kDa, shows identity with different plant fructosyltransferases and invertases, which belong to the glycoside hydrolase 32 family. When sucrose was used as substrate, only the transference products 1-kestose and glucose were identified, while from 1-kestose, nystose and fructose were obtained as transference and hydrolysis products respectively, with sucrose as a secondary product. The enzyme has a low turnover number (260 min(-1)) at 30 degrees C, with optimal stability at 25 degrees C and pH 5.5. In order to identify the probable residues involved in the active site, a three-dimensional model was built using the fructan I-exohydrolase IIa from Cichorium intybus (PDB entry 1st8) as template. This is the first report concerning cloning and expression of an Agave fructosyltransferase. (c) 2007 Elsevier Ireland Ltd. All rights reserved. C1 Univ Nacl Autonoma Mexico, Inst Biotecnol, Cuernavaca 62250, Morelos, Mexico. RP Lopez-Munguia, A, Univ Nacl Autonoma Mexico, Inst Biotecnol, Apartado Postal 510-3, Cuernavaca 62250, Morelos, Mexico. EM agustin@ibt.unam.mx CR BATISTA FR, 1999, BIOCHEM J 3, V337, P503 CEDENO M, 1995, CRIT REV BIOTECHNOL, V15, P1 DELZENNE NM, 2001, AM J CLIN NUTR, V73, P456 FRANCK A, 2006, NUTR B, V31, P341 GHAZI I, 2007, J BIOTECHNOL, V128, P204 GIBSON GR, 1995, J NUTR, V128, P11 HENDRY GAF, 1993, NEW PHYTOL, V123, P3 HENRISSAT B, 1997, CURR OPIN STRUC BIOL, V7, P637 KAPLAN H, 2003, APPL ENVIRON MICROB, V69, P2217 KAWAKAMI A, 2002, BIOSCI BIOTECH BIOCH, V66, P2297 KOOPS AJ, 1996, PLANT PHYSIOL, V110, P1167 LASKOWSKI RA, 1993, J APPL CRYSTALLOGR, V26, P283 LHOCINE L, 2000, J BIOTECHNOL, V81, P73 LOPEZ MG, 2003, J AGR FOOD CHEM, V51, P7835 LUND O, 2002, CASP5 C, A102 LUSCHER M, 1996, FEBS LETT, V385, P39 LUSCHER M, 2000, NEW PHYTOL, V145, P225 LUSCHER M, 2000, PLANT PHYSIOL, V124, P1217 NAGEM RAP, 2004, J MOL BIOL, V344, P471 PARTIDA V, 1998, 5846333, US PONS T, 2000, PROTEIN SCI, V9, P2285 ROCHESTER DE, 1986, EMBO J, V5, P451 SATYANARAYANA MN, 1976, J BIOCH BIOPHYS, V13, P261 SPRENGER N, 1995, P NATL ACAD SCI USA, V92, P11652 UENO K, 2005, NEW PHYTOL, V165, P813 VANDENENDE W, 1996, PHYSIOL PLANTARUM, V98, P455 VANDENENDE W, 2005, PHYSIOL PLANTARUM, V125, P419 VERGAUWEN R, 2003, PLANT PHYSIOL, V133, P391 VERHAEST M, 2005, PLANT J, V41, P400 VIJN I, 1997, PLANT J, V11, P387 VIJN I, 1998, PLANT PHYSIOL, V117, P1507 NR 31 TC 0 PU ELSEVIER IRELAND LTD PI CLARE PA ELSEVIER HOUSE, BROOKVALE PLAZA, EAST PARK SHANNON, CO, CLARE, 00000, IRELAND SN 0168-9452 J9 PLANT SCI JI Plant Sci. PD OCT PY 2007 VL 173 IS 4 BP 478 EP 486 PG 9 SC Biochemistry & Molecular Biology; Plant Sciences GA 211TD UT ISI:000249545300012 ER PT J AU Sepulveda, J Tapia-Conyer, R Velasquez, O Valdespino, JL Olaiz-Fernandez, G Kuri, P Sarti, E Conde-Gonzalez, CJ AF Sepulveda, Jaime Tapia-Conyer, Roberto Velasquez, Oscar Valdespino, Jose Luis Olaiz-Fernandez, Gustavo Kuri, Pablo Sarti, Elsa Conde-Gonzalez, Carlos J. TI National Health Survey 2000: design and methodology SO SALUD PUBLICA DE MEXICO LA Spanish DT Article DE methodology; demographic analysis; cross-sectional analysis; Mexico AB Objective. The 2000 Mexican National Health Survey (NHS) was created as part of the System for National Health Surveys conducted during the last months of 1999 and the first three of 2000. The 2000 NHS is a probabilistic survey of households from which users of health services were selected according to three age groups. Information was gathered through direct interviews with appropriate informants. Biological samples were taken for clinical tests as well as for measuring biological and somatometric parameters. Material and Methods. The sample design of the 2000 NHS was stratified and clustered. Sample size was 1 470 households per state for a total of 47 040 households nationwide (there are 32 states in Mexico). Sample weights were calculated and modified according to the non-response and post-stratified to calibrate for population distribution. Interviewers were trained in order to maintain a high response rate, especially for biological samples. Results. A total of 83 157 blood samples were collected from the 94 000 expected (88% response rate). All samples were refrigerated immediately after collection and divided in four vials for storage at the National Institute for Public Health's laboratory. Samples were frozen at - 150 degrees Celsius until further analysis. C1 Inst Nacl Salud Publ, Cuernavaca 62508, Morelos, Mexico. Secretaria Salud Mexico, Mexico City, DF, Mexico. Ctr Nacl Vigilancia Epidemiol & Control Enfermeda, Mexico City, DF, Mexico. RP Olaiz-Fernandez, G, Inst Nacl Salud Publ, Av Univ 655,Col Santa Maria Ahuacatitlan, Cuernavaca 62508, Morelos, Mexico. EM olaiz@insp.mx CR *SECR MED AMB, 1996, NOM087ECOL1995 SECR *SECR SAL, 1985, DIR GEN EP ENC NAC S *SECR SAL, 1988, DIR GEN EP ENC NAC N *SECR SAL, 1992, DIR GEN EP ENC NAC C *SECR SAL, 1993, DIR GEN EP ENC NAC C *SECR SAL, 1998, DIR GEN EP ENC NAC A ANDERSEN R, 1978, MED CARE, V16, P533 ARREDONDO A, 1992, SALUD PUBLICA MEXICO, V34, P36 AVEDIS D, 1988, JAMA-J AM MED ASSOC, V260, P1743 COCHRAN WG, 1982, TECNICAS MUESTREO, P513 FRENK J, 1985, SALUD PUBLICA MEXICO, V27, P438 GUTIERREZ G, 1988, SALUD PUBLICA MEXICO, V30, P836 LEE E, 1989, ANAL COMPLEX SURVEY RIVERADOMARCO J, 2001, ENCUESTA NACL NUTR 1 TAPIACONYER R, 1994, SALUD PUBLICA MEXICO, V30, P843 TINAJERO M, 2000, SERIE MONOGRAFIAS, V9, P113 NR 16 TC 0 PU INST NACIONAL SALUD PUBLICA PI CUERNAVACA PA AV UNIVERSIDAD 655, COL SANTA MARIA AHUACATITLAN, CUERNAVACA 62508, MORELOS, MEXICO SN 0036-3634 J9 SALUD PUBLICA MEXICO JI Salud Publica Mexico PY 2007 VL 49 SU Suppl. 3 BP S427 EP S432 PG 6 SC Public, Environmental & Occupational Health GA 196MV UT ISI:000248487600015 ER PT J AU Fragiel, A Serna, S Campillo, B Cota, L AF Fragiel, A. Serna, S. Campillo, B. Cota, L. TI Dissimilar mechanical properties - micro structures microalloyed pipeline steels cracking performance under sour environment SO MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING LA English DT Article DE microalloyed steels; microstructure; sour environment; strength; cracking mechanisms AB The cracking behavior of an API 5L X52 microalloyed pipeline steel at 25 and 50 degrees C, under a sour environment, is compared with the cracking behavior of an API 5L X65 microalloyed pipeline steel with different microstructure and mechanical properties. The results show that the microstructure of X65 steel is much more resistant to develop and propagate a crack under proportional stress intensity factors and the same sour environmental conditions at room temperature (25 degrees C). The reverse result was obtained at 50 degrees C, however, a comparative growth in % criteria shows that X52 steel does not present a much better resistance to propagate a crack than X65 steel. These behaviors at both temperatures are indicative that steels microstructures might play an important role to resist cracking. (c) 2007 Elsevier B.V. All rights reserved. C1 UAEM, Ctr Invest Ingn & Ciencias Aplicadas, Cuernavaca 62209, Morelos, Mexico. Univ Nacl Autonoma Mexico, Ctr Ciencias Mat Condensada, Ensenada, Baja California, Mexico. Univ Nacl Autonoma Mexico, Inst Ciencias Fis, Fac Quim, Cuernavaca, Morelos, Mexico. RP Serna, S, UAEM, Ctr Invest Ingn & Ciencias Aplicadas, Av Univ 1001, Cuernavaca 62209, Morelos, Mexico. EM aserna@uaem.mx CR *ASTM, 1998, E399 ASTM, P745 *NACE INT, 1999, MR017599 NACE INT *NACE INT, 1999, TM017799 NACE ANELLI E, 1988, PROCESSING MICROSTRU, P489 ASAHI H, 1987, CORROSION, P87 BIRNBAUM HK, 1990, ENV INDUCED CRACKING, V10, P21 CAMPBELL JE, 1982, APPL FRACTURE MECH S, P47 DEANS WF, 1979, J TEST EVAL, V7, P147 EBOUJDAINI M, 1998, 748 NACE INT FRAGIEL B, 2005, INT J HYDROGEN ENERG, V30, P1303 MILITZER M, 1998, ADV IND MAT, P63 MILITZER M, 2000, METALL MATER TRANS A, V31, P1247 NOVAK SR, 1969, J MATER, V4, P701 PERELOMA EV, 1996, MATER SCI TECH SER, V12, P808 SEDRIKS AJ, 1990, CORROS TEST MADE EAS, V1, P50 SERNA S, 2005, INT J HYDROGEN ENERG, V30, P1333 VENEGAS V, 2005, SCRIPTA MATER, V52, P147 VERMILYEA DA, 1977, STRESS CORROSION CRA, P208 NR 18 TC 0 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0921-5093 J9 MATER SCI ENG A-STRUCT MATER JI Mater. Sci. Eng. A-Struct. Mater. Prop. Microstruct. Process. PD OCT 15 PY 2007 VL 467 IS 1-2 BP 1 EP 7 PG 7 SC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary GA 205WX UT ISI:000249146400001 ER PT J AU Contreras, A Angeles-Chavez, C Flores, O Perez, R AF Contreras, A. Angeles-Chavez, C. Flores, O. Perez, R. TI Structural, morphological and interfacial characterization of Al-Mg/TiC composites SO MATERIALS CHARACTERIZATION LA English DT Article DE composites; wetting; infiltration; TiC; Al-Mg-alloys ID MELT INFILTRATION; MATRIX COMPOSITES; ALUMINUM-ALLOYS; WETTABILITY; REFINEMENT; MAGNESIUM; KINETICS AB Morphological and structural characterization of Al-Mg/TiC composites obtained by infiltration process and wetting by the sessile drop technique were studied. Focusing at the interface, wetting of TiC substrates by molten Al-Mg-alloys at 900 C was investigated. Electron probe microanalysis (EPMA) indicated that aluminum carbide (Al4C3) is formed at the interface and traces of TiAl3 in the wetting assemblies were detected. Scanning Electron Microscopy (SEM) observations show that TiC particles do not appear to be uniformly attacked to produce a continuous layer of Al4C3 at the interface. Molten Al-Mg-alloys were infiltrated into TiC preforms with flowing argon at a temperature of 900 degrees C. In the composites no reaction phase was observed by SEM. Quantification of the Al phase in the composite was carried out by X-ray diffraction (XRD) and Rietveld analysis. Chemical mapping analyzed by SEM shows that the Al-Mg alloy surrounds TiC particles. In the composites with 20 wt.% of Mg the Al-Mg-beta phase was detected through XRD. (C) 2006 Elsevier Inc. All rights reserved. C1 Inst Mexicano Petr, Programa Invest Ductos Corros & Mat, Mexico City 07730, DF, Mexico. Univ Nacl Autonoma Mexico, Inst Ciencias Fis, Cuernavaca 62191, Morelos, Mexico. RP Contreras, A, Inst Mexicano Petr, Programa Invest Ductos Corros & Mat, Eje Cent Lazaro Cardenas 152, Mexico City 07730, DF, Mexico. EM acontrer@imp.mx CR AGUILAR EA, 2002, COMPOS PART A-APPL S, V33, P1425 BALE CW, 2000, FACT WIN VER 3 0 CONTRERAS A, 2000, MATER MANUF PROCESS, V15, P163 CONTRERAS A, 2003, SCRIPTA MATER, V48, P1625 CONTRERAS A, 2004, SCRIPTA MATER, V51, P249 FINE ME, 1990, METALL TRANS A, V21, P2609 FROUMIN N, 1997, SCRIPTA METALL, V37, P1263 JIANG QC, 2003, SCRIPTA MATER, V48, P713 LEON CA, 2002, J MATER SCI, V37, P3509 LIU LM, 2004, SURF SCI, V550, P46 LLYOD DJ, 1994, INT MATER REV, V39, P1 MUSCAT D, 1992, MATER SCI TECH SER, V8, P971 MUSCAT D, 1994, METALL MATER TRANS A, V25, P2357 PAI BC, 1995, J MATER SCI, V30, P1903 PRINCE E, 1981, J APPL CRYSTALLOGR, V14, P157 THOMPSON P, 1987, J APPL CRYSTALLOGR, V20, P79 YOUNG RA, 1995, J APPL CRYSTALLOGR, V28, P366 NR 17 TC 0 PU ELSEVIER SCIENCE INC PI NEW YORK PA 360 PARK AVE SOUTH, NEW YORK, NY 10010-1710 USA SN 1044-5803 J9 MATER CHARACT JI Mater. Charact. PD AUG-SEP PY 2007 VL 58 IS 8-9 SI Sp. Iss. SI BP 685 EP 693 PG 9 SC Materials Science, Characterization & Testing GA 195TW UT ISI:000248435800004 ER PT J AU Rosas, G Reyes-Gasga, J Perez, R AF Rosas, G. Reyes-Gasga, J. Perez, R. TI Morphological characteristics of the rapidly and conventionally solidified alloys of the AlCuFe system SO MATERIALS CHARACTERIZATION LA English DT Article DE conventional casting; rapid solidification; morphology; quasicrystal; phase transformations ID AL-CU-FE; QUASI-CRYSTALS; ICOSAHEDRAL PHASE; TRANSFORMATIONS; DIAGRAM AB Different alloy compositions of AlCuFe in the composition range of Al (75-65), Cu (25-15) and Fe (15-7) at.% have been studied. Experimental results obtained in the Al70Cu20Fe10 and Al65Cu20Fe15 alloys prepared by conventional casting and Al74Cu18Fe8 and Al66Cu21Fe13 alloys produced by rapidly solidified techniques are presented. All these alloys were annealed at 600, 700, 850 and 950 degrees C and characterized using X-ray diffraction, scanning and transmission electron microscopy techniques. Several morphological aspects of the crystalline and the quasicrystalline phases as a function of the different solidification processes were observed. The experimental conditions where both crystalline and quasicrystalline phases coexist were analysed. The experimental results suggest the decomposition of ternary alloys such as: omega-Al7Cu2Fe, beta-Al-6(Cu,Fe) and psi-Al6Cu2Fe to binary compounds such as: theta-Al2Cu and Al13Fe4. C1 UMSNH, Inst Invest Met, Morelia 58000, Michoacan, Mexico. UNAM, Inst Fis, Mexico City 01000, DF, Mexico. Univ Nacl Autonoma Mexico, Inst Ciencias Fis, Cuernavaca 62251, Morelos, Mexico. RP Rosas, G, UMSNH, Inst Invest Met, Edificio U,Ciudad Univ, Morelia 58000, Michoacan, Mexico. EM grtrejo@jupiter.umich.mx CR BRADLEY AJ, 1939, J I MET, V65, P403 CHENG YF, 1990, PHIL MAG LETT, V61, P173 DELAISSARDIERE GT, 1994, MATER SCI FORUM, V150, P417 DONG C, 1990, J PHYS-CONDENS MAT, V2, P6339 EBALARD S, 1989, J MATER RES, V4, P39 EBALARD S, 1990, J MATER RES, V5, P62 FAUDOT F, 1991, MAT SCI ENG A-STRUCT, V133, P383 GAYLE FW, 1992, METALL TRANS A, V23, P2409 GIGLA M, 1997, P 17 C APPL CRYST KA GRATIAS D, 1993, J NON-CRYST SOLIDS, V153, P482 HOLLANDMORITZ D, 1997, MAT SCI ENG A-STRUCT, V226, P976 LIU W, 1991, Z METALLKD, V82, P791 ROSAS G, 1998, MATER LETT, V36, P229 ROSAS G, 2001, MAT SCI ENG A-STRUCT, V298, P79 ROSAS G, 2001, MATER LETT, V47, P225 STEURER W, 1994, MATER SCI FORUM, V150, P15 TAKEUCHI S, 1994, MATER SCI FORUM, V150, P35 ZHANG Z, 1990, SCRIPTA METALL MATER, V24, P1329 NR 18 TC 0 PU ELSEVIER SCIENCE INC PI NEW YORK PA 360 PARK AVE SOUTH, NEW YORK, NY 10010-1710 USA SN 1044-5803 J9 MATER CHARACT JI Mater. Charact. PD AUG-SEP PY 2007 VL 58 IS 8-9 SI Sp. Iss. SI BP 765 EP 770 PG 6 SC Materials Science, Characterization & Testing GA 195TW UT ISI:000248435800016 ER PT J AU Garcia-Hernandez, L Deciga-Campos, M Guevara-Lopez, U Lopez-Munoz, FJ AF Garcia-Hernandez, Liliana Deciga-Campos, Myma Guevara-Lopez, Uriah Lopez-Munoz, Francisco Javier TI Co-administration of rofecoxib and tramadol results in additive or sub-additive interaction during arthritic nociception in rat SO PHARMACOLOGY BIOCHEMISTRY AND BEHAVIOR LA English DT Article DE inflammatory pain; cyclooxygenase; rofecoxib; tramadol; synergism ID SYNERGISTIC ANTINOCICEPTIVE INTERACTION; GASTROINTESTINAL MOTOR FUNCTION; KETOROLAC POTENTIATES MORPHINE; INDUCED FUNCTIONAL IMPAIRMENT; NITRIC-OXIDE; CYCLOOXYGENASE-2 INHIBITOR; ANALGESIC INTERACTIONS; RHEUMATOID-ARTHRITIS; SEROTONERGIC SYSTEM; DIRECT ANTAGONISM AB Over the decades, nonsteroidal anti-inflammatory drugs (NSAIDs) and opioids are the most commonly used analgesics in the management of acute and chronic pain. In order to assess a possible antinociceptive interactions, the antinociceptive effects of rofecoxib p.o., a preferential inhibitor of cyclooxygenase-2, and tramadol-hydrochloride p.o., an atypical opioid analgesic, administered either separately or in combination, were determined using a rat model of arthritic pain. The data were interpreted using the surface of synergistic interaction (SSI) analysis and an isobolographic analysis to establish the nature of the interaction. The SSI was calculated from the total antinociceptive effect produced by the combination after subtraction of the antinociceptive effect produced by each individual drug. Female rats received orally rofecoxib alone (1.0, 1.8. 3.2. 5.6. 10.0, 17.8, 31.6 and 56.2 mg/kg), tramadol alone (1.8, 3.2, 5.6, 10.0, 17.8, 31.6 and 56.2 mg/kg) or 12 different combinations of rofecoxib plus tramadol. Five combinations exhibited various degrees of sub-additive (i.e. less than the sum of the effects produced by the each drug alone) antinociceptive effects (3.2 mg/kg tramadol with 7.8 mg/kg rofecoxib; 5.6 mg/kg tramadol with either 10.0 or 17.8 mg/kg rofecoxib; 10.0 mg/kg tramadol with either 10.0 or 17.8 mg/kg rofecoxib), whereas the other 7 combinations showed additive antinociceptive effects (i.e. the sum of the effects produced by each agent alone). Three combination of rofecoxib+tramadol (10.0+5.6, 10.0+10.0, and 17.8+5.6 mg/kg respectively) presented high sub-additive interactions (P<0.002: Q 9.5). The combination rofecoxib (17.8 mg/kg)+tramadol (10.0 mg/kg) caused gastric injuries less severe than those observed with indomethacin, but more severe than those obtained with rofecoxib or tramadol in single administration. The antinociceptive interaction of rofecoxib and tramadol suggests that combinations with these drugs may have no clinical utility in pain therapy. (c) 2007 Elsevier Inc. All rights reserved. C1 Dept Farmacobiol, Mexico City, DF, Mexico. Univ Autonoma estado Morelos, Fac Farm, Cuernavaca, Morelos, Mexico. IMSS, UMAE Magdalena Salinas, Inst Nacl med & Nutr Salvador Subiran Invest, Clin Dolor, Mexico City, DF, Mexico. RP Lopez-Munoz, FJ, Dept Farmacobiol, 7 Doior & Analgesia Calz tenorios 235 Col Granuja, Mexico City, DF, Mexico. EM flopez@cinvestav.mx CR BERROCOSO E, 2006, NEUROPHARMACOLOGY, V51, P146 BOMBARDIER C, 2000, NEW ENGL J MED, V343, P1520 BURIAN M, 2005, PHARMACOL THERAPEUT, V107, P139 CHAN CC, 1999, J PHARMACOL EXP THER, V290, P551 COVINO BG, 1980, PAIN, V9, P141 DEBRECENI A, 1997, J PHYSIOLOGY-PARIS, V91, P189 DECIGACAMPOS M, 2003, EUR J PHARMACOL, V460, P99 DECIGACAMPOS M, 2003, P W PHARMACOL SOC, V46, P165 DECIGACAMPOS M, 2004, P W PHARMACOL SOC, V47, P100 DEMBO G, 2005, ANESTHESIOLOGY, V102, P409 DUARTE IDG, 1992, EUR J PHARMACOL, V217, P225 EHRLICH K, 2004, J PHARMACOL EXP THER, V308, P277 ESPLUGUES JV, 1992, BRIT J PHARMACOL, V106, P846 GRIFFIN MR, 1998, AM J MED, V104, P23 HAWKEY CJ, 2003, GUT, V52, P820 HEIM HK, 2006, DIG DIS, V96, P423 HOYOVADILLO C, 1995, J PHARM PHARMACOL, V47, P462 KWON MS, 2005, PHARMACOLOGY, V74, P152 LAYTON D, 2003, BRIT J CLIN PHARMACO, V55, P166 LEE YH, 1971, ARCH INT PHARMAC0DYN, V191, P370 LEWIS KS, 1997, AM J HEALTH-SYST PH, V54, P643 LIZARRAGA I, 2006, RES VET SCI, V80, P194 LOPEZ JRM, 2006, EUR J PHARMACOL, V544, P31 LOPEZMUNOZ FJ, 1993, DRUG DEVELOP RES, V28, P169 LOPEZMUNOZ FJ, 1993, DRUG DEVELOP RES, V29, P229 LOPEZMUNOZ FJ, 1994, DRUG DEVELOP RES, V33, P26 LOPEZMUNOZ FJ, 1994, P W PHARMACOL SOC, V37, P17 LOPEZMUNOZ FJ, 1995, DRUG DEVELOP RES, V35, P13 LOPEZMUNOZ FJ, 1995, DRUG DEVELOP RES, V35, P94 LOPEZMUNOZ FJ, 1995, METHOD FIND EXP CLIN, V17, P311 LOPEZMUNOZ FJ, 2004, EUR J PHARMACOL, V484, P157 LORENZETTI BB, 1985, EUR J PHARMACOL, V114, P375 MAVES TJ, 1994, ANESTHESIOLOGY, V80, P1094 MEHLISCH DR, 2002, J AM DENT ASSOC, V133, P861 MOTILVA V, 2005, INT IMMUNOPHARMACOL, V5, P369 MOTSKO SP, 2006, DRUG SAFETY, V29, P621 PICARD P, 1997, PAIN, V73, P401 RAFFA RB, 1993, J PHARMACOL EXP THER, V267, P331 ROWLAND M, 1989, CLIN PHARMACOKINET, P255 SALAZAR LA, 1995, DRUG DEVELOP RES, V36, P119 SANDRINI M, 1998, EUR J PHARMACOL, V355, P133 SANDRINI M, 1999, INFLAMM RES, V48, P120 SATYANARAYANA PSV, 2004, PROG NEURO-PSYCHOPH, V28, P641 SCHMASSMANN A, 2006, AM J PHYSIOL-GASTR L, V290, G747 SEEGERS AJM, 1981, ARCH INT PHARMACOD T, V251, P237 TALLARIDA RJ, 1989, LIFE SCI, V45, P947 TAYLOR J, 1998, EUR J PHARMACOL, V351, P39 TORTORICI V, 1995, EUR J NEUROSCI, V7, P1857 VAUGHAN CW, 1997, NATURE, V390, P611 VAUGHAN CW, 1998, BRIT J PHARMACOL, V123, P1479 WATSON DJ, 2004, CURR MED RES OPIN, V20, P1539 WEIWU P, 1999, ANESTH ANALG, V689, P995 WIDEMAN GL, 1999, CLIN PHARMACOL THER, V65, P66 WILDERSMITH CH, 1997, BRIT J CLIN PHARMACO, V43, P71 WILDERSMITH CH, 1999, ANESTHESIOLOGY, V91, P639 WILDERSMITH CH, 1999, DIGEST DIS SCI, V44, P1107 ZIMMERMANN M, 1983, PAIN, V16, P109 NR 57 TC 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0091-3057 J9 PHARMACOL BIOCHEM BEHAV JI Pharmacol. Biochem. Behav. PD AUG-SEP PY 2007 VL 87 IS 3 BP 331 EP 340 PG 10 SC Behavioral Sciences; Neurosciences; Pharmacology & Pharmacy GA 206MU UT ISI:000249188400005 ER PT J AU Fuentes, BE Tejeda, A Martinez, H AF Fuentes, B. E. Tejeda, A. Martinez, H. TI Dissociative capture and collision-induced dissociation of H-2(+) in SF6 SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS LA English DT Article DE dissociative capture; collision induced dissociation; fragmentation mechanism; ion fragmentation energies; differential cross-sections; crosssection; H-2(+); SF6 ID ELECTRON-CAPTURE; IONS AB Absolute differential and total cross-sections for the production of H+ and H-0 fragments in the energy range of 1-5 keV and scattering angles from -4.6 degrees to 4.6 degrees, for the collision of H-2(+) on SF6 are reported. The differential and total cross-sections for dissociative capture 2 (DC) and collision-induced dissociation (CID) were estimated. The differential cross-sections (DCS) of DC and CID for all acceleration energies show a monotonic decrease with increasing angle, showing an overall decrease of three and two orders of magnitude for DC and CID respectively. The total cross-section for the DC process is found to be in the range of 10.0-40.0 angstrom(2), while for the CID process it is between 0.8 and 2.3 angstrom(2). Both measured total cross-sections display a slowly increasing behavior as a function of the incident energy. The results show that the cross-section for the DC process is about 13.2 times higher in average than that for the CID process. (c) 2007 Elsevier B.V. All rights reserved. C1 Univ Nacl Autonoma Mexico, Fac Ciencias, Mexico City 04510, DF, Mexico. Univ Nacl Autonoma Mexico, Inst Ciencias Fis, Cuernavaca 04510, Morelos, Mexico. RP Fuentes, BE, Univ Nacl Autonoma Mexico, Fac Ciencias, Mexico City 04510, DF, Mexico. EM befm@hp.fciencias.unam.mx hm@fis.unam.mx CR BENHENNI M, 2005, PHYS REV E 2, V71 BENITZHAK I, 2005, PHYS REV LETT, V95 CHRISTOPHOROU LG, 2000, J PHYS CHEM REF DATA, V29, P267 HASAN AT, 2005, INT J MASS SPECTROM, V247, P81 LOS J, 1978, COLLISION SPECTROSCO, P289 MARTINEZ H, 2004, PHYS REV A, V69 SUZUKI Y, 1986, NUCL INSTRUM METH B, V16, P397 YANG X, 2005, PLASMA SOURCES SCI T, V14, P412 NR 8 TC 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-583X J9 NUCL INSTRUM METH PHYS RES B JI Nucl. Instrum. Methods Phys. Res. Sect. B-Beam Interact. Mater. Atoms PD AUG PY 2007 VL 261 IS 1-2 BP 197 EP 199 PG 3 SC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Atomic, Molecular & Chemical; Physics, Nuclear GA 200SW UT ISI:000248784100050 ER PT J AU Santiago, MDN Tecante, A AF Santiago, Maria del Carmen Nunez Tecante, Alberto TI Viscoelastic properties of cross-linked waxy cornstarch and kappa-carrageenan mixtures under a wide range of potassium counter-ion concentrations SO JOURNAL OF CENTRAL SOUTH UNIVERSITY OF TECHNOLOGY LA English DT Article DE kappa-carrageenan; starch; gels; viscoelasticity AB The small-deformation shear behavior at 25 degrees C of 1%-4%(mass fraction) cross-linked waxy corn starch (CWCS) and 0.5%(mass fraction) KC mixtures with and without KCI were studied. Dispersions were heated (1.5 degrees C/min) to 90 V, held for 10 min, then cooled (1.5 degrees C/min) to 90 degrees C. When the volume fraction of CWCS is about 0.5 to 0.7, the rheological behavior is governed by the continuous phase, while above these values the disperse phase dominates the theological behavior. When carrageenan is in a disordered state without KCI, the swollen granules are dispersed in a macromolecular solution. With KCI, the rigidity of the gels increases by effect of CWCS, carrageenan and salt concentrations. However, salt concentrations above 100 mmol/L lead to a marginal increase in rigidity. Results can be interpreted in terms of two types of systems: particles suspended in a macromolecular solution and composite gels of particles embedded in a network matrix when both KC and KCI were added. C1 CEPROBI IPN, Dept Desarrollo Tecnol, Yautepec Morelos 62731, Mexico. Univ Nacl Autonoma Mexico, Fac Quim, Dept Aliment & Biotecnol, Mexico City 04510, DF, Mexico. RP Santiago, MDN, CEPROBI IPN, Dept Desarrollo Tecnol, Km 8 5 Carretera Yautepec Jojutla,Col San Isidro, Yautepec Morelos 62731, Mexico. EM mnunez@ipn.mx CR ACQUARONE VM, 2003, CARBOHYD POLYM, V51, P451 ARGUELLESMONAL W, 1998, POLYM GELS NETW, V6, P429 DESCAMPS O, 1986, FOOD TECHNOL-CHICAGO, V40, P81 FERRY JD, 1980, VISCOELASTIC PROPERT NICKERSON MT, 2004, CARBOHYD POLYM, V58, P15 ROCHAS C, 1982, STUDY SOLGEL TRANSIT TECANTE A, 1999, CARBOHYD POLYM, V40, P221 NR 7 TC 0 PU JOURNAL OF CENTRAL SOUTH UNIV TECHNOLOGY PI HUNAN PA EDITORIAL OFFICE, CHANGSHA, HUNAN 410083, PEOPLES R CHINA SN 1005-9784 J9 J CENT SOUTH UNIV TECHNOL JI J. Cent. South Univ. Technol. PD AUG PY 2007 VL 14 SU Suppl. 1 BP 210 EP 212 PG 3 SC Metallurgy & Metallurgical Engineering GA 202PK UT ISI:000248915300048 ER PT J AU Andres, AC Guadalupe, MM Javier, SF Arturo, BPL AF Andres, Aguirre-Cruz Guadalupe, Mendez-Montealvo Javier, Solorza-Feria Luis Arturo, Bello-Perez TI Effect of carboxymethylcellulose and xanthan gum on rheological profile of dried maize masa SO JOURNAL OF CENTRAL SOUTH UNIVERSITY OF TECHNOLOGY LA English DT Article DE dried masa; nixtamalisation; carboxymethylcellulose; xanthan gum; rheology; zea mays ID STARCH AB Maize masa was obtained using a traditional nixtarnalisation process, and then freeze-dried to obtain dried masa. Both masa dispersions with 10%(w/V) total solids control (DM), masa dispersions mixed with carboxymethylcellulose (CMC) and xanthan gum (0.2% and 0.5%(mass fraction) gum solids) named masa with hydrocolloid (DMH) were prepared by distilled water, and the rheological properties were tested. Dynamic oscillatory measurements were performed on a TA Instruments AR-1000 Controlled Strain Rheometer using a parallel plates system with a diameter of 60 mm and a gap of 200 gm. The strain amplitude sweeps were run from 0.1% to 3% in the 1st stage (at 25 degrees C) and from 0.1 % to 5% in the 2nd (at 90 degrees C) and 3rd stages (at 25 degrees C) of a heating (at 25-95 degrees C, stage 1) - cooking (95 degrees C, 10 min, stage 2)-cooling (95 degrees C to 25 degrees C, stage3) kinetics at a frequency value of 1 Hz. Once the linear viscoelastic region was found, the frequency sweeps (0.1-10 Hz) were run when a constant strain value of 0.3% was used in the 1st and 2nd stages and of 0.5% in the 3rd stage of the kinetics. All masa samples (DM and DMH) behave as viscoelastic gels with G' (elastic modulus) >G '' (viscous modulus), when all masu samples are subjected to three stages of heating-cooking-cooling kinetics using increments in the moduli values as progressing from one stage to another. Overall, the hydrocolloid addition decreases both moduli values, probably by interfiring with the masa components structure in an aqueous environment. The smoothest gel is the one of DMH-xanthan with 0.5% (mass fraction) of solids. C1 IPN, Ctr Desarrollo Productos Biot, Yautepec, Morelos, Mexico. RP Javier, SF, IPN, Ctr Desarrollo Productos Biot, Km 85 Carr Yautepec Jojutla Col San Isidro Aparta, Yautepec, Morelos, Mexico. EM jsolorza@ipn.mx CR CHRISTIANSON DD, 1981, CEREAL CHEM, V58, P513 FERRY JR, 1980, VISCOELASTIC PROPERT FOX E, 1995, MANUAL USUARIO SIGMA RENDONVILLALOBOS R, 2002, CEREAL CHEM, V79, P340 ROJAS JA, 1999, FOOD HYDROCOLLOID, V13, P27 SHI XH, 2002, CARBOHYD POLYM, V50, P7 TWILLMAN TJ, 1988, CEREAL CHEM, V65, P253 WALPOLE ER, 1991, PROBABILIDAD ESTADIS NR 8 TC 0 PU JOURNAL OF CENTRAL SOUTH UNIV TECHNOLOGY PI HUNAN PA EDITORIAL OFFICE, CHANGSHA, HUNAN 410083, PEOPLES R CHINA SN 1005-9784 J9 J CENT SOUTH UNIV TECHNOL JI J. Cent. South Univ. Technol. PD AUG PY 2007 VL 14 SU Suppl. 1 BP 514 EP 517 PG 4 SC Metallurgy & Metallurgical Engineering GA 202PK UT ISI:000248915300119 ER PT J AU Guadalupe, MM Javier, SF Francisco, GS Arturo, BPL AF Guadalupe, Mendez-Montealvo Javier, Solorza-Feria Francisco, Garcia-Suarez Luis Arturo, Bello-Perez TI Rheological changes in nixtamalised maize starch SO JOURNAL OF CENTRAL SOUTH UNIVERSITY OF TECHNOLOGY LA English DT Article DE nixtamalisation; starch; theology; zea mays ID TORTILLA AB In Mexico, a great deal of maize lines are growth, most of them go through the process of nixtamalisation (lye treatment at boiling temperature) to produce masa, which is used to mainly elaborate tortillas. During this process, the heat treatment brings about biochemical reactions, cross-links and molecular interactions that modify the physicochemical, structural and rheological properties of the masa as well as those of the tortillas produced. A high percentage of these changes is due to modifications in the structure of starch, the main chemical component of maize. Control starch (S) was isolated from a lot of maize and another lot of the same maize sample was subjected to lye treatment to obtain nixtamalised starch (NS). Rheological studies were carried out to determine its amylographic profile (Bravender), following a heating-cooking-cooling kinetics. Flow curves were carried out at 25 degrees C and 40 degrees C (heating-cooling,25 degrees C-90 degrees C-40 degrees C), using a strain controlled rheometer (TA Instruments AR-1000) with a cone and plate system, angle of 1 degrees. The dynamic oscillatory tests were carried out in a heating-cooling kinetics (25 degrees C-90 degrees C-25 degrees C) with the same geometry (angle of 1 degrees), in dispersions with 10%(w/V) of total solids. Maximum viscosity and molecular dissociation were higher in the control starch. The flow curves show that all samples (S and NS) behave as Newtonian fluids at 25 degrees C, which shifts to a shear-thinning behaviour at 40 degrees C and show a more pronounced tendency. In the dynamic tests, all starch gels obtained present weak viscoelastic gel-like behaviour predominating the elastic or storage modulus (G') over the viscous or loss modulus (G '') during the three stages of the heating-cooling kinetics. According to tan delta values, nixtamalised starch forms amorphous gels, while control starch starch produces gels with a crystalline structure. C1 IPN, Ctr Desarrollo Productos Biot, Yautepec, Morelos, Mexico. RP Guadalupe, MM, IPN, Ctr Desarrollo Productos Biot, Km 85 Carr Yautepec Jojutla Col San Isidro Aparta, Yautepec, Morelos, Mexico. EM cmendez@ipn.mx CR *AM ASS CER CHEM, 2000, APPR METH AACC CAMPUSBAYPOLI ON, 1999, STARCH-STARKE, V51, P173 FERRY JR, 1980, VISCOELASTIC PROPERT GOMEZ MH, 1992, CEREAL CHEM, V69, P275 ROONEY LW, 1999, CEREAL FOOD WORLD, V44, P466 STEFFE JF, 1992, PHEOLOGICAL METHODS NR 6 TC 0 PU JOURNAL OF CENTRAL SOUTH UNIV TECHNOLOGY PI HUNAN PA EDITORIAL OFFICE, CHANGSHA, HUNAN 410083, PEOPLES R CHINA SN 1005-9784 J9 J CENT SOUTH UNIV TECHNOL JI J. Cent. South Univ. Technol. PD AUG PY 2007 VL 14 SU Suppl. 1 BP 518 EP 521 PG 4 SC Metallurgy & Metallurgical Engineering GA 202PK UT ISI:000248915300120 ER PT J AU Iglesias, AL Munoz-Hernandez, M Garcia, JJ AF Iglesias, Ana L. Munoz-Hernandez, Miguel Garcia, Juventino J. TI Fluoro aromatic imine nickel(0) complexes: Synthesis and structural studies SO JOURNAL OF ORGANOMETALLIC CHEMISTRY LA English DT Article DE nickel(0); imines; fluorinated ligands; crystal structure ID CARBON-CARBON BONDS; C-N BONDS; CATALYTIC HYDRATION; METAL-COMPLEXES; ACTIVATION; CLEAVAGE; ISOMERIZATION; BENZONITRILE; ALDIMINES; NITRILES AB The reaction of [Ni(dippe)](2)(mu-H)(2) with a series of fluoroaromatic imines affords nickel(0) complexes of the type [(dippe)Ni(eta(2)-C, N)PhHC=NR ' Ph], dippe = 1,2-bis(diisopropylphosphine)ethane. Solution NMR experiments as well as X-ray diffraction studies confirmed the pi-coordination of the ligand through the C=N moiety; the resulting complex found to adopt a distorted tetrahedral geometry around the nickel center. The compounds are thermally stable and decomposition is only observed after long periods of heating above 150 degrees C. (c) 2007 Elsevier B.V. All rights reserved. C1 Univ Nacl Autonoma Mexico, Fac Quim, Mexico City 04510, DF, Mexico. Univ Autonoma Estado Morelos, Ctr Invest Quim, Morelos 62210, Mexico. RP Garcia, JJ, Univ Nacl Autonoma Mexico, Fac Quim, Mexico City 04510, DF, Mexico. EM juvent@servidor.unam.mx CR ACOSTARAMIREZ A, 2006, J ORGANOMET CHEM, V691, P3895 ANDERSON CM, 1992, ORGANOMETALLICS, V11, P1177 BAAR C, 2004, ORGANOMETALLICS, V19, P4150 BACH I, 1996, ORGANOMETALLICS, V15, P4959 BRUNKAN NM, 2004, J AM CHEM SOC, V126, P3627 BURGESS DA, 1984, AUS J CHEM, V37, P176 BURGI HB, 1970, HELV CHIM ACTA, V53, P1747 BURLING S, 2005, J CHEM SOC DA, P3686 CALLIGARIS ML, 1986, COMPREHENSIVE ORGANO, V2, P717 CEDER RM, 1998, DALTON T, P1047 CLEMENS J, 1971, J CHEM SOC CHEM COMM, P1095 CLOT E, 2003, DALTON T, P4065 CRESPO M, 1993, ORGANOMETALLICS, V12, P4297 CRESTANI MG, 2006, ADV SYNTH CATAL, V348, P732 CRISOSTOMO C, 2007, J MOL CATAL A-CHEM, V266, P139 CRONIN L, 1997, ORGANOMETALLICS, V16, P4920 EAGLE CT, 1998, ORGANOMETALLICS, V17, P4523 FRYZUK MD, 1990, ORGANOMETALLICS, V9, P986 GABOR B, 1991, ANGEW CHEM INT EDIT, V30, P1666 GAMOVSKII AD, 1998, COORDIN CHEM REV, V126, P1 GARCIA JJ, 2000, ORGANOMETALLICS, V19, P5544 GARCIA JJ, 2002, J AM CHEM SOC, V124, P9547 GARCIA JJ, 2004, ORGANOMETALLICS, V23, P3997 HOLTZ D, 1971, CHEM REV, V1, P139 HORBERF H, 1979, J ORGANOMET CHEM, V169, P209 IGLESIAS AL, UNPUB J FLUOR CHEM JAMES BR, 1997, CATAL TODAY, V37, P209 KARSCH HH, 1999, ORGANOMETALLICS, V18, P90 KIPLINGER JL, 1994, CHEM REV, V94, P373 KUKUSHKIN VY, 2005, INORG CHIM ACTA, V358, P1 LI AW, 1994, J FLUORINE CHEM, V68, P145 LIN BL, 2002, J AM CHEM SOC, V124, P2890 LIU XY, 2004, SYNTHESIS-STUTT 0402, P683 OLAH GA, 1974, J ORG CHEM, V39, P2394 REINHOLD M, 2004, J AM CHEM SOC, V126, P5268 TAFT RW, 1963, J AM CHEM SOC, V85, P3146 TOTI A, 2004, CR CHIM, V7, P769 VICIC DA, 1997, J AM CHEM SOC, V119, P10855 NR 38 TC 0 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0022-328X J9 J ORGANOMET CHEM JI J. Organomet. Chem. PD JUL 15 PY 2007 VL 692 IS 16 BP 3498 EP 3507 PG 10 SC Chemistry, Inorganic & Nuclear; Chemistry, Organic GA 194ZQ UT ISI:000248382700023 ER PT J AU Nunez-Santiago, MD Tecante, A AF Nunez-Santiago, Maria del Carmen Tecante, Alberto TI Rheological and calorimetric study of the sol-gel transition of kappa-carrageenan SO CARBOHYDRATE POLYMERS LA English DT Article DE kappa-carrageenan; gels; sol-gel transition; viscoelasticity; DSC ID CONFORMATIONAL TRANSITION; STRUCTURAL CHARACTERISTICS; CONCENTRATION-DEPENDENCE; LINEAR VISCOELASTICITY; POINT; BEHAVIOR; GELATION; DSC AB Rheological and DSC techniques were used to study the effect Of K-carrageenan and KCl concentrations, 0-300 mM, on the sol-gel transition as well as on the linear viscoelasticity, at 25 degrees C, of the resulting gels. In heating and cooling DSC tests, the peak temperature was taken as the sol-gel transition point. In theological tests, sol-gel transitions were determined from the variation of dynamic moduli with frequency and temperature, the independence of the phase angle on frequency and the evolution with temperature of dynamic moduli on cooling and heating at constant frequency and strain. Transition temperatures from DSC and theology were in good agreement among them and with those previously reported. The three procedures yielded similar results, but the transition temperatures were more easily determined through the independence of the phase angle on frequency. Frequency sweeps showed gel behavior with stiffness increasing with polysaccharide and salt concentration. Below 100 mM KCI, G' increased notably, whereas higher concentrations produced only marginal increases. (c) 2007 Elsevier Ltd. All rights reserved. C1 Ctr Desarrollo Prod Bioticos, Yautpec 62731, Morelos, Mexico. Univ Nacl Autonoma Mexico, Dept Alimentos & Biotecnol, Fac Quim E, Mexico City 04510, DF, Mexico. RP Tecante, A, Ctr Desarrollo Prod Bioticos, Km 8-5 Carr, Yautpec 62731, Morelos, Mexico. EM tecante@servidor.unam.mx CR BOUTEBBA A, 1997, BIOPOLYMERS, V42, P811 CHAMBON F, 1987, J RHEOL, V31, P683 CHEN Y, 2002, CARBOHYD POLYM, V50, P109 CORDOBES F, 2004, RHEOL ACTA, V43, P184 DOUBLIER JL, 1996, CARBOHYDRATES FOOD, P312 ELDRIDGE JE, 1954, J PHYS CHEM-US, V58, P992 FERRY JD, 1980, VISCOELASTIC PROPERT FUCHS T, 1997, POLYM GELS NETW, V5, P541 GOYCOOLEA FM, 2001, INT J BIOL MACROMOL, V29, P181 HOSSAIN KS, 2001, BIOMACROMOLECULES, V2, P442 HSU S, 1999, J FOOD SCI, V64, P136 HSU S, 2000, J FOOD SCI, V65, P215 KARA S, 2003, INT J BIOL MACROMOL, V31, P177 LABROPOULOS AE, 1996, J FOOD SCI, V61, P65 MACARTAIN P, 2003, CARBOHYD POLYM, V53, P395 MANGIONE MR, 2003, BIOPHYS CHEM, V104, P95 MANGIONE MR, 2004, BIOPHYS CHEM, V113, P129 MICHON C, 1993, RHEOL ACTA, V32, P94 MICHON C, 1995, FOOD MACROMOLECULES, P462 MILAS M, 1996, CARBOHYD POLYM, V30, P177 MIYOSHI E, 1996, CARBOHYD POLYM, V30, P109 NAYOUF M, 2003, THESIS ECOLE NATL IN NISHINARI K, 1997, COLLOID POLYM SCI, V275, P1093 NISHINARI K, 2003, CURR OPIN COLLOID IN, V8, P396 NITTA Y, 2003, BIOMACROMOLECULES, V4, P1654 NITTA Y, 2004, BIOMACROMOLECULES, V5, P1206 REGINALD HW, 1998, POLYSACCHARIDE DISPE RINAUDO M, 2001, FOOD HYDROCOLLOID, V15, P433 ROCHAS C, 1982, CARBOHYD RES, V105, P227 ROCHAS C, 1982, THESIS I NATL POLYTE ROCHAS C, 1987, CARBOHYD POLYM, V7, P435 ROOD AB, 2001, RHEOL ACTA, V40, P23 ROSSMURPHY SB, 1991, RHEOL ACTA, V30, P401 SCANLAN JC, 1991, MACROMOLECULES, V24, P47 SUGIYAMA M, 1998, PHYS B, P999 TAKEMASA M, 2001, MACROMOLECULES, V34, P7427 TECANTE A, 1999, CARBOHYD POLYM, V40, P221 WINTER HH, 1986, J RHEOL, V30, P367 YUGUCHI Y, 2002, FOOD HYDROCOLLOID, V16, P515 YUGUCHI Y, 2003, FOOD HYDROCOLLOID, V17, P481 NR 40 TC 0 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0144-8617 J9 CARBOHYD POLYM JI Carbohydr. Polym. PD JUL 2 PY 2007 VL 69 IS 4 BP 763 EP 773 PG 11 SC Chemistry, Applied; Chemistry, Organic; Polymer Science GA 180US UT ISI:000247392200019 ER PT J AU Corona, AM Toledo, VH Morrone, JJ AF Corona, Angelica Ma. Toledo, Victor H. Morrone, Juan J. TI Does the Trans-mexican Volcanic Belt represent a natural biogeographical unit? An analysis of the distributional patterns of Coleoptera SO JOURNAL OF BIOGEOGRAPHY LA English DT Review DE biogeography; Buprestidae; Cerambycidae; Dryophthoridae; Melolonthidae; Mexico; Nearctic; Neotropics; Passalidae; Staphylinidae ID TROPICAL DRY FOREST; CERAMBYCIDAE COLEOPTERA; SUBTRIBE HIPPOMELANINA; LECONTE COLEOPTERA; CENTRAL-AMERICA; BUPRESTIDAE; REVISION; RECORDS; ENTOMOFAUNA; DIVERSITY AB Aim We analysed the geographical distribution of beetle species of the families Buprestidae, Cerambycidae, Dryophthoridae, Melolonthidae, Passalidae and Staphylinidae from the Trans-mexican Volcanic Belt (TVB) through a track analysis and a parsimony analysis of endemicity (PAE), in order to test its naturalness and determine its affinities. Location The area analysed corresponds to the TVB, which is a biogeographical province of the Mexican Transition Zone. Methods The panbiogeographical analysis was based on the comparison of the individual tracks of 299 species of Buprestidae, Cerambycidae, Dryophthoridae, Melolonthidae, Passaliclae and Staphylinidae (Coleoptera). The TVB was divided into 1 degrees x 1 degrees grid cells and we also included in the analysis the remaining Mexican biogeographical provinces. Parsimony analysis of endemicity with progressive character elimination (PAE-PCE) was applied to classify areas by their shared taxa according to the most parsimonious cladograms. The nested sets of areas were represented as generalized tracks. Results Three generalized tracks were obtained: (1) grid cells 9C, 9D, 10D, 10E, Sierra Madre Oriental, Chiapas, Mexican Gulf and the Sierra Madre del Sur; (2) grid cells 3B, 3C, 4B, 4C, 5C, 6C, 7C, Sierra Madre Occidental, Sierra Madre del Sur, Balsas Basin and the Mexican Pacific Coast, and (3) grid cells 8D, 9C, 9D, 10D, 10E, Yucatan Peninsula, Chiapas, Sierra Madre Oriental and the Mexican Gulf. Main conclusions We conclude that the TVB does not represent a natural biogeographical unit because it shows different relationships with other biogeographical provinces, being clearly transitional between the Nearctic and Neotropical provinces. Some parts of the TVB are related to Neotropical provinces (Chiapas, Mexican Gulf and Mexican Pacific Coast) and others to the remaining provinces of the Mexican Transition Zone (Sierra Madre Oriental, Sierra Madre del Sur, Sierra Madre Occidental and Balsas Basin). C1 UNAM, Museum Zool, Fac Ciencias, Dept Evolut Biol, Mexico City 04510, DF, Mexico. UAEM, Ctr Educ Ambiental & Invest Sierra Huautla, Cuernavaca 62209, Morelos, Mexico. RP Morrone, JJ, UNAM, Museum Zool, Fac Ciencias, Dept Evolut Biol, Apartado Postal 70-399, Mexico City 04510, DF, Mexico. 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Biogeogr. PD JUN PY 2007 VL 34 IS 6 BP 1008 EP 1015 PG 8 SC Ecology; Geography, Physical GA 179BR UT ISI:000247264800007 ER PT J AU Mendez, YE Vlasova, M Leone, I Kakazey, MG Dominguez-Patino, M Isaeva, L Tomila, T AF Mendez, Y. Enriquez Vlasova, M. Leone, I. Kakazey, M. G. Dominguez-Patino, M. Isaeva, L. Tomila, T. TI Low temperature synthesis of porous silicate ceramics SO SCIENCE OF SINTERING LA English DT Article DE kaolin; feldspar; glass; polyurethane sponge; synthesis AB Impregnation of a polyurethane sponge with kaolin, feldspar, silica, fusible glass slurry followed by temperature treatment in air in the temperature range 800-1000 degrees C leads to the formation of aluminosilicate ceramics with a set pore size. The low-temperature synthesis of porous ceramics is based on the stage-by-stage formation of low-temperature eutectics and thermodestruction of polyurethane sponge. C1 Autonomous Univ State Moreols, Cuernavaca, Morelos, Mexico. Natl Acad Sci Ukraine, Inst Problems Mat Sci, UA-252680 Kiev, Ukraine. RP Kakazey, MG, Autonomous Univ State Moreols, Av Univ 1001, Cuernavaca, Morelos, Mexico. EM kakazey@hotmail.com CR BELOMERYA NI, 2004, VOPR KHIM KHIM TEKHN, V1, P58 BUDNIKOV PP, 1968, TECHNOLOGY CERAMICS DAS SK, 2003, THERMOCHIM ACTA, V406, P199 FEND T, 2004, SOL ENERG MAT SOL C, V84, P291 GORYAINOV VV, 2002, THESIS GUZMAN IY, 1971, REFRACTORY HIGH PORO JULBE A, 2005, CATAL TODAY, V104, P102 KINGERY WD, 1963, INTRO CERAMICS NACAMOTO K, 1970, INFRA RED SPECTRA IN NETTLESHIP I, 1996, KEY ENG MAT, V122, P305 OSBORN EF, 1964, PHASE DIAGRAMS CERAM SEPULVEDA P, 1999, J EUR CERAM SOC, V19, P2059 SHARAFAT S, 2004, 16 ANS TOP M TECHN F SOMIYA S, HDB ADV CERAMICS, P291 NR 14 TC 0 PU INT INST SCIENCE SINTERING (I I S S) PI BELGRADE PA C/O ITN SANU, KNEZ MIHAILOVA 35/IV, PO BOX 315, 11000 BELGRADE, YUGOSLAVIA SN 0350-820X J9 SCI SINTER JI Sci. Sinter. PD JAN-APR PY 2007 VL 39 IS 1 BP 39 EP 49 PG 11 SC Materials Science, Ceramics; Metallurgy & Metallurgical Engineering GA 176ZI UT ISI:000247123000006 ER PT J AU Cabrera-Trujillo, R Deumens, E Ohrn, Y Quinet, O Sabin, JR Stolterfoht, N AF Cabrera-Trujillo, R. Deumens, E. Ohrn, Y. Quinet, O. Sabin, J. R. Stolterfoht, N. TI Water-molecule fragmentation induced by charge exchange in slow collisions with He+ and He2+ ions in the keV-energy region SO PHYSICAL REVIEW A LA English DT Article ID ELECTRON-NUCLEAR-DYNAMICS; DENSITY-FUNCTIONAL THEORY; GAUSSIAN-BASIS SETS; CROSS-SECTIONS; VELOCITY DEPENDENCE; O5++H-2 COLLISIONS; X-RAY; IONIZATION; CAPTURE; IMPACT AB Charge exchange and fragmentation in the collision systems He2+ + H2O and He+ + H2O are theoretically investigated at projectile energies of a few keV. The calculations are based on the electron nuclear dynamics (END) method which solves the time-dependent Schrodinger equation. Total and differential cross sections for charge exchange are evaluated by averaging over 10 orientations of the H2O molecule. Summed total electron capture cross sections are found to be in good agreement with available experimental data. Projectile scattering was studied in the full angular range with respect to the incident beam direction. The theory provides a description of the fragmentation mechanisms such as Coulomb explosion and binary collision processes. For impact parameters below 3.5 a.u., we find that single and double electron capture occurs, resulting always in full fragmentation of H2O independent of the target orientation for He-3(2+) ions. Hydrogen and oxygen fragments and its respective ions, are studied as a function of emission angle and energy. In the binary collisions regime the theoretical results are found to be in excellent agreement with previous experimental data. In the Coulomb explosion regime the theoretical data are found to peak at specific angles including 90 degrees which is consistent with the experiment. C1 Univ Nacl Autonoma Mexico, Inst Ciencias Fis, Cuernavaca 62251, Morelos, Mexico. Univ Florida, Dept Phys, Quantum Theory Project, Gainesville, FL 32610 USA. Univ Florida, Dept Chem, Quantum Theory Project, Gainesville, FL 32610 USA. Hahn Meitner Inst Berlin GmbH, D-14109 Berlin, Germany. RP Cabrera-Trujillo, R, Univ Nacl Autonoma Mexico, Inst Ciencias Fis, Apartado Postal 48-3, Cuernavaca 62251, Morelos, Mexico. CR ABUHAIJA O, 2003, NUCL INSTRUM METH B, V205, P634 ALVERADO F, 2005, J PHYS B ATOM MOL PH, V38, P4085 ANUSIEWICZ I, 2004, J PHYS CHEM A, V108, P11381 BENITZHAK I, 1988, PHYS REV A, V37, P3685 BENITZHAK I, 1994, PHYS REV A, V49, P881 BENITZHAK I, 2000, PHYS REV LETT, V85, P58 BERDYS J, 2004, J PHYS CHEM B, V108, P5800 BIAGLOW JE, 1987, RAD CHEM PRINCIPLES, P527 BISHOF G, 1986, Z PHYS D, V1, P303 BRANSDEN BH, 1992, CHARGE EXCHANGE THEO BRENA B, 2004, PHYS REV LETT, V93 BROECKHOVE J, 1992, TIME DEPENDENT QUANT CABRERATRUJILLO R, 2000, PHYS REV A, V61 CABRERATRUJILLO R, 2000, PHYS REV A, V62 CAR R, 1985, PHYS REV LETT, V55, P2471 CHENG S, 1993, PHYS REV A, V47, P3923 CRAVENS TE, 1997, GEOPHYS RES LETT, V24, P105 DELOS JB, 1981, REV MOD PHYS, V53, P287 DEUMENS E, 1988, J PHYS CHEM-US, V92, P3181 DEUMENS E, 1992, J CHEM PHYS, V96, P6820 DEUMENS E, 1994, REV MOD PHYS, V66, P917 DEUMENS E, 1997, J CHEM SOC FARADAY T, V93, P919 DEUMENS E, 2001, J PHYS CHEM A, V105, P2660 DEUMENS E, 2002, ENDYNE VERSION 5 SOF DUNNING TH, 1989, J CHEM PHYS, V90, P1007 FAASEN MV, 2006, INT J MOD PHYS B, V20, P3419 FEELER CR, 1999, PHYS REV A, V60, P2112 FEELER CR, 1999, PHYS SCR, V59, P106 FOLKERTS HO, 1996, PHYS REV LETT, V77, P3339 FREMONT F, 2000, J PHYS B-AT MOL OPT, V33, L249 GOBET F, 2001, PHYS REV LETT, V86, P3751 GOBET F, 2004, PHYS REV A, V70 GREENWOOD JB, 2000, ASTROPHYS J 1, V529, P605 GREENWOOD JB, 2004, PHYS SCR T, V110, P358 JACQUEMIN D, 1997, J CHEM PHYS, V107, P6146 KHARCHENKO V, 2000, J GEOPHYS RES, V105, P18 LISSE CM, 1996, SCIENCE, V274, P205 LUNA H, 2005, PHYS REV LETT, V94 MULLIKEN RS, 1955, J CHEM PHYS, V23, P1833 NEWTON RG, 1982, SCATTERING THEORY WA PESIC ZD, 2004, J PHYS B-AT MOL OPT, V37, P1405 REMSCHEID A, 1995, NUCL INSTRUM METH B, V98, P257 RICHARDSON PJ, 1986, J CHEM PHYS, V84, P3189 RUDD ME, 1985, PHYS REV A, V32, P2499 RUNGE E, 1984, PHYS REV LETT, V52, P997 SAYLER AM, 2006, J PHYS B-AT MOL OPT, V39, P1701 SCHIFF LI, 1956, PHYS REV, V103, P443 SEREDYUK B, 2005, PHYS REV A, V71 SOBOCINSKI P, 2001, AIP CONF PROC, V576, P114 SOBOCINSKI P, 2002, J PHYS B-AT MOL OPT, V35, P1353 SOBOCINSKI P, 2005, J PHYS B-AT MOL OPT, V38, P2495 SOBOCINSKI P, 2006, J PHYS B-AT MOL OPT, V39, P927 TAO JM, 2005, PHYS REV LETT, V95 TARISIEN M, 2000, J PHYS B-AT MOL OPT, V33, L11 THOULESS DJ, 1960, NUCL PHYS, V21, P225 WARGELIN JB, 2001, ASTROPHYS J, V546, L57 WERNER U, 1995, NUCL INSTRUM METH B, V98, P385 WERNER U, 1995, PHYS REV LETT, V74, P1962 WOOD CJ, 1999, PHYS REV A, V59, P1317 WOON DE, 1994, J CHEM PHYS, V100, P2975 YOUSIF FB, 1988, J PHYS B ATOM MOL PH, V21, P4157 NR 61 TC 1 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1050-2947 J9 PHYS REV A JI Phys. Rev. A PD MAY PY 2007 VL 75 IS 5 AR 052702 DI ARTN 052702 PG 13 SC Optics; Physics, Atomic, Molecular & Chemical GA 173RO UT ISI:000246890400089 ER PT J AU Bello-Perez, LA Islas-Hernandez, JJ Rendon-Villalobos, JR Agama-Acevedo, E Morales-Franco, L Tovar, J AF Bello-Perez, Luis A. Islas-Hernandez, Jose Juan Rendon-Villalobos, J. Rodolfo Agama-Acevedo, Edith Morales-Franco, Leticia Tovar, Juscelino TI In vitro starch digestibility of fresh and sun-dried faba beans (Vicia faba L.) SO JOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE LA English DT Article DE broad bean; cold storage; faba bean; glycaemic index; starch; starch digestibility ID PHASEOLUS-VULGARIS L.; RESISTANT STARCH; GLYCEMIC INDEX; INVITRO DIGESTIBILITY; CHEMICAL-COMPOSITION; INSULIN RESPONSES; LEGUME STARCHES; HUMAN-NUTRITION; STEAM-COOKING; BLOOD-GLUCOSE AB Fresh and sun-dried faba beans (Vicia faba L.) were cooked, stored for various times at 4 degrees C and analysed for available starch (AS), resistant starch (RS) and fibre-associated resistant starch (FARS) contents as wen as a-amylolysis. Fresh beans required a shorter cooking time (25 min) than dried beans (158 min). Cooked fresh faba beans had a higher AS content than cooked dried faba beans. The AS content in both decreased during cold storage, with fresh beans showing a smaller decrease than dried beans with increasing storage time. Cooked fresh faba beans also had a higher total RS content than cooked dried faba beans, although a greater increase in RS content was recorded in the latter upon storage. Starch retrogradation was more prominent in cooked dried faba beans than in cooked fresh faba beans, as indicated by the consistently higher FARS content. The alpha-amylolysis rate decreased with increasing storage time, i.e. long-stored (72 h) cooked faba beans exhibited slower starch digestion, and differences were recorded between fresh and dried beans. The predicted glycaemic index ranged between 60.9 and 58.0% for cooked fresh faba beans and between 57.9 and 55.8% for cooked dried faba beans, which is suggestive of slow glucose release from starch in faba beans. (c) 2007 Society of Chemical Industry. C1 IPN, Ctr Desarrolo Prod Bioticos, Yautepec, Morelos, Mexico. Cent Univ Venezuela, Fac Ciencias, Inst Expt Biol, Caracas, Venezuela. Cent Univ Venezuela, Fac Ciencias, Inst Expt Biol, Caracas 1041A, Venezuela. RP Bello-Perez, LA, IPN, Ctr Desarrolo Prod Bioticos, Km 8-5 Carr Yautepec Jojutla,Apartado Postal 24, Yautepec, Morelos, Mexico. 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Sci. Food Agric. PD JUN PY 2007 VL 87 IS 8 BP 1517 EP 1522 PG 6 SC Agriculture, Multidisciplinary; Chemistry, Applied; Food Science & Technology GA 174EV UT ISI:000246925300012 ER PT J AU Garcia-Valladares, O AF Garcia-Valladares, O. TI Numerical simulation of non-adiabatic capillary tubes considering metastable region. Part II: Experimental validation SO INTERNATIONAL JOURNAL OF REFRIGERATION-REVUE INTERNATIONALE DU FROID LA English DT Article DE refrigeration; air conditioning; two-phase flow; capillary tube; modeling; transient; metastable state; experiment AB A detailed one-dimensional steady and transient numerical simulation of the thermal and fluid-dynamic behavior of capillary tube-suction line heat exchangers considering metastable region and separated flow has been developed in Part I of this paper. The developed numerical model allows analysis of aspects such as geometry, type of fluid, critical or non-critical flow conditions and metastable region. The accuracy of the detailed simulation model is demonstrated in this part (Part II) of the paper by comparing simulation results with a wide range of steady state experimental data from the technical literature, which include the refrigerant mass flow rate, outlet suction line temperature, and temperature profile along concentric and lateral capillary tube-suction line heat exchangers. Of the 196 data points evaluated for mass flow rate 96.4% are within an error of +/- 15%, 81.1% are within +/- 10% with a mean deviation of +/- 6.3%. Of the 143 data points evaluated for outlet suction line temperature 89.5% are within an error of +/- 2 degrees C, with a mean deviation of +/- 0.98 degrees C. The numerical results obtained are used to understand the refrigerant flow behavior inside non-adiabatic capillary tubes. Some divergence problems in the numerical solution process is found to be the discontinuity in non-adiabatic capillary tube flow characteristics caused by re-condensation of the refrigerant within the heat exchanger zone; this aspect needs special attention while modeling the non-adiabatic capillary tube flow. Other important parameter to be evaluated experimentally with special care is the capillary tube internal diameter due to its strong influence on the refrigerant flow results (results of any study based on the nominal diameter are to be used with caution). (C) 2006 Elsevier Ltd and IIR. All rights reserved. C1 Univ Nacl Autonoma Mexico, Ctr Invest Energia, Temixco 62580, Morelos, Mexico. RP Garcia-Valladares, O, Univ Nacl Autonoma Mexico, Ctr Invest Energia, Apdo Postal 34, Temixco 62580, Morelos, Mexico. EM ogv@cie.unam.mx CR BITTLE RR, 1995, ASHRAE TRAN 1, V101, P124 CHEN ZH, 1990, ASHRAE T, V96, P550 DIRIK E, 1994, P 1994 INT REFR C PU, P365 GARCIAVALLADARES O, 2007, INT J REFRIG, V30, P642 MELO C, 1999, ASHRAE T, V105, P51 MELO C, 2000, P INT REFR C PURD, P305 MELO C, 2002, APPL THERM ENG, V22, P1661 MENDOCA KC, 1998, P INT REFR C PURD, P437 PEIXOTO RA, 1995, P 19 INT C REFR HAG, V3, P437 WOLF DA, 2002, 948RP ASHRAE NR 10 TC 0 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0140-7007 J9 INT J REFRIG JI Int. J. Refrig.-Rev. Int. Froid PD JUN PY 2007 VL 30 IS 4 BP 654 EP 663 PG 10 SC Thermodynamics; Engineering, Mechanical GA 174JF UT ISI:000246937500009 ER PT J AU Iniguez-Covarrubias, M de Leon-Mojarro, B Prado-Hernandez, JV Rendon-Pimentel, L AF Iniguez-Covarrubias, Mauro de Leon-Mojarro, Benjamin Prado-Hernandez, Jorge Victor Rendon-Pimentel, Luis TI Comparative analysis of three methods to determine canal capacities, applied to the La Begona irrigation district. Hydraulic engineering in Mexico SO INGENIERIA HIDRAULICA EN MEXICO LA Spanish DT Article DE canal capacity; continuous flow; irrigation flexibility AB Distribution and regulation methods are based on the conveyance capacity of canals. Currently, there are three methods widely used for estimating the conveyance capacity of networks: the Irrigation Unit Coefficient (IUC) method, the Clement method, and the Clemmens method. Each was applied in the La Begona Irrigation District. This work shows the application of these methods in irrigation canal design and we discuss the results obtained through the performance evaluation of the main right-bank conveyance canal in the La Begona District, which covers 8,132 hectares. Constructed more than 40 years ago, it was based on crop pattern, design and operation criteria that were much different than the present demands of flexibility and efficiency of water use. For the application of these methods we considered the average crop pattern of the last fourteen agricultural cycles, the global water use efficiency and the agronomic, climate, technological and operational information of the irrigation district. The results show that the three methods provide a conveyance capacity above the continuous flow and with which all provide different flexibility degrees. However, the most feasible is the Clement probabilistic method for estimating the conveyance capacity of the irrigation canals, since it relates the parcel irrigation operation with the water distribution network. C1 Inst Mexicano Tecnol Agua, Jiutepec 62550, Morelos, Mexico. Comis Nacl Agua, Mexico City 04340, DF, Mexico. RP Iniguez-Covarrubias, M, Inst Mexicano Tecnol Agua, Paseo Cuauhnahuac 8232, Jiutepec 62550, Morelos, Mexico. EM mic@tlaloc.imta.mx bleon@tlaloc.imta.mx joviph@colpos.mx luis.rendon@cna.gob.mx CR *ICID, 2005, INT C IRR DRAIN BE C, V1 *IMTA, 1997, MAN DIS ZON RIEG PEQ, P41 *INIGUEZ, 1994, THESIS CTR HIDROCIEN *SRH, 1973, PROYECT ZON RIEG BURT MC, 1987, S P NEW YORK ASCE CLEMENT R, 1979, COMPUTATION FLOW IRR CLEMMENS AJ, 1986, J IRRIG DRAIN ENG, V112, P331 CLEMMENS AJ, 1987, S P NEW YORK ASCE DELEON B, 1981, AGROCIENCIA, V45, P105 DELEON B, 1992, PROPUESTA AUTOMATIZA GONZALEZ J, 1999, INGENIERIA HIDRAULIC, V14, P11 INFANTE S, 1984, METODES ESTADISTICOS, P616 KEMPTHORNE O, 1971, PROBABILITY STAT DAT, P85 MONSERRAT J, 2004, J IRRIG DRAIN E-ASCE, V130, P99 OJEDA BW, 1999, PRONOSTICO RIEGO TIE ZIEROLD RL, 1969, INGENIERIA HIDRAULIC, V23, P78 NR 16 TC 0 PU INSTITUTO MEXICANO TECHNOLOGIAAGUA PI MORELOS PA APARTADO POSTAL 202, MORELOS 62550 CIVAC, MEXICO SN 0186-4076 J9 ING HIDRAUL MEX JI Ing. Hidraul. Mex. PD APR-JUN PY 2007 VL 22 IS 2 BP 81 EP 90 PG 10 SC Engineering, Civil; Water Resources GA 174GV UT ISI:000246931100007 ER PT J AU Messina, S Nair, MTS Nair, PK AF Messina, Sarah Nair, M. T. S. Nair, P. K. TI Antimony sulfide thin films in chemically deposited thin film photovoltaic cells SO THIN SOLID FILMS LA English DT Article DE chemical deposition; antimony sulfide; thin films; photovoltaic structures ID BATH DEPOSITION; LAYERS; SB2S3 AB Antimony sulfide thin films of thickness approximate to 500 nm have been deposited on glass slides fi-om chemical baths constituted with SbCl3 and sodium thiosulfate. Smooth specularly reflective thin films are obtained at deposition temperatures from - 3 to 10 degrees C. The differences in the film thickness and improvement in the crystallinity and photoconductivity upon annealing the film in nitrogen are presented. These films can be partially converted into a solid solution of the type Sb2SxSe3 -(x3) detected in X-ray diffraction, through heating them in contact with a chemically deposited selenium thin film. This would decrease the optical band gap of the film from approximate to 1.7 eV (Sb2S3) to approximate to 1.3 eV for the films heated al. 300 degrees C. Similarly, heating at 300 degrees C of sequentially deposited thin film layers of Sb2S3-Ag2Se, the latter also from a chemical bath at 10 degrees C results in the formation of AgSb(S/Se)(2) with an optical gap of approximate to 1.2 eV. All these thin films have been integrated into photovoltaic structures using a US window layer deposited on 3 mm glass sheets with a SnO2:F coating (TEC-15, Pilkington). Characteristics obtained in these cells under an illumination of 850 W/m(2) (tungsten halogen) are as follows: SnO2:F-CdS-Sb2S3-Ag(paint) with open circuit voltage (V-oc) 470 mV and short circuit current density (J(sc) 0.02 mA/cm(2). SnO2:F-CdS-Sb2S3-CuS-Ag(paint), V-oc approximate to 460 mV and J(sc) approximate to 0.4 mA/cm(2); SnO2:F-CdS-Sb2Sx Se-3-(x)-Ag(paint), V-oc approximate to 670 mV and J(sc) approximate to 0.05 mA/cm(2); SnO2:F-CdS-Sb2S3-AgSb(S/Se)(2)-Ag(paint), V-oc approximate to 450 mV and J(sc) approximate to 1.4 mA/cm(2). we consider that the materials and the deposition techniques reported here are promising toward developing 'all-chemically deposited solar cell technologies. (C) 2007 Elsevier B.V. All rights reserved. C1 Univ Nacl Autonoma Mexico, Ctr Invest Energia, Dept Solar Energy Mat, Temixco 62580, Morelos, Mexico. RP Messina, S, Univ Nacl Autonoma Mexico, Ctr Invest Energia, Dept Solar Energy Mat, Temixco 62580, Morelos, Mexico. EM mtsn@cie.unam.mx CR BINDU K, 2004, SEMICOND SCI TECH, V19, P1348 BINDU K, 2005, SEMICOND SCI TECH, V20, P496 BINDU K, 2006, J ELECTROCHEM SOC, V153, C526 BINDU K, 2006, J ELECTROCHEM SOLID, V9, G195 GROZDANOV I, 1994, SEMICOND SCI TECH, V9, P1234 MADELUNG O, 1992, SEMICONDUCTORS OTHER NAIR MTS, 1998, J ELECTROCHEM SOC, V145, P2113 PEJOVA B, 2000, MATER LETT, V43, P269 RODRIGUEZLAZCANO Y, 2001, J CRYST GROWTH, V223, P399 RODRIGUEZLAZCANO Y, 2005, J ELECTROCHEM SOC, V152, G635 SAVADOGO O, 1992, SOL ENERG MAT SOL C, V26, P117 SAVADOGO O, 1994, J ELECTROCHEM SOC, V141, P2781 SAVADOGO O, 1994, J PHYS D APPL PHYS, V27, P1070 SMITH RA, 1978, SEMICONDUCTORS+, P314 SUAREZSANDOVAL DY, 2006, J ELECTROCHEM SOC, V153, C91 NR 15 TC 0 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0040-6090 J9 THIN SOLID FILMS JI Thin Solid Films PD MAY 31 PY 2007 VL 515 IS 15 BP 5777 EP 5782 PG 6 SC Materials Science, Multidisciplinary; Materials Science, Coatings & Films; Physics, Applied; Physics, Condensed Matter GA 172VC UT ISI:000246831600008 ER PT J AU Gonzalez, AEJ Santiago, SG AF Jimenez Gonzalez, A. E. Gelover Santiago, S. TI Structural and optoelectronic characterization of TiO2 films prepared using the sol-gel technique SO SEMICONDUCTOR SCIENCE AND TECHNOLOGY LA English DT Article ID THIN-FILMS; OPTICAL-PROPERTIES; ANATASE TIO2; ZINC-OXIDE; CELL; MICROSTRUCTURE; DEPOSITION; PARTICLES; DEFECTS; WATER AB TiO2 is a versatile material that makes for fascinating study in any of its several physical forms: monocrystal, polycrystal, powder or thin film. Its enhanced photosensitivity to UV radiation and excellent chemical stability in acidic and aqueous media point to its excellent potential for use in a variety of applications, such as solar cells, electronic devices, chemical sensors and photocatalysts. Of late, thin films of TiO2 have permitted the study of physical and chemical properties that are almost impossible to examine in powders. Using the sol - gel technique, it was possible to prepare TiO2 films, and to specifically modify their characteristic properties by means of annealing treatments. Optical measurements carried out on sol - gel derived films produced results similar to those found in films prepared using the sputtering technique. The use of TiO2 films facilitates the study of the behaviour of crystalline structure, grain size, photoresponse, electrical conductivity in both darkness and light and energy band gap (E-g) as a function of treatment temperature. For the first time, it has been demonstrated that the photoconductivity of TiO2 becomes apparent at a treatment temperature of 350 degrees C, which means that below this temperature the material is not photosensitive. The photosensitivity (S) of TiO2 films prepared by the sol - gel technique reaches values between 10(0) and 10(4), surpassing by more than two orders of magnitude the photosensitivity of TiO2 in powder form. In addition, it was possible to study the surface crystalline structure, where TEM studies clearly revealed both the polycrystalline order and the atomic arrangements of the TiO2 films. Our findings will afford us an opportunity to better study the nature of TiO2 and to enhance its performance with respect to the above-mentioned applications. C1 Univ Nacl Autonoma Mexico, Ctr Invest Energia, Dept Mat Solares, Temixco 62580, Morelos, Mexico. RP Gonzalez, AEJ, Univ Nacl Autonoma Mexico, Ctr Invest Energia, Dept Mat Solares, Temixco 62580, Morelos, Mexico. EM ajg@mazatl.cie.unam.mx CR ANAST M, 1994, THIN SOLID FILMS, V253, P303 BATTISTON GA, 1994, THIN SOLID FILMS, V239, P186 BIANCONI A, 1979, PHYS REV B, V19, P2837 BRINKER JC, 1990, SOL GEL SCI PHYS CHE, P4 CHEREPY NJ, 1997, J PHYS CHEM B, V101, P9342 CHOI H, 2006, THIN SOLID FILMS, V510, P107 CHRYSICOPOULOU P, 1998, THIN SOLID FILMS, V323, P188 DING XZ, 1997, MAT SCI ENG A-STRUCT, V224, P210 DOMARADZKI J, 2006, THIN SOLID FILMS, V513, P269 DUENAS S, 2005, SEMICOND SCI TECH, V20, P1044 FORRO L, 1994, J APPL PHYS, V75, P633 GARCIA CG, 1998, J PHOTOCH PHOTOBIO A, V115, P239 GARCIA VM, 1997, SEMICOND SCI TECH, V12, P645 GERISCHER H, 1992, J ELECTROCHEM SOC, V139, P113 GOPEL W, 1980, PHYS REV B, V22, P6447 HAGFELDT A, 1992, SOL ENERG MAT SOL C, V27, P293 HEILAND G, 1961, J PHYS CHEM SOLIDS, V22, P227 HU LL, 1992, THIN SOLID FILMS, V219, P18 JIMENEZGONZALEZ A, 1996, J CRYST GROWTH, V167, P649 JIMENEZGONZALEZ AE, 1998, J CRYST GROWTH, V192, P430 KARUNAGARAN B, 2003, CRYST RES TECHNOL, V38, P773 KOENENKAMP R, 1994, THIN SOLID FILMS, V246, P13 KOPFSTADT P, 1983, NONSTOICHCHIOMETRY D, P57 KROEGER FH, 1956, SOLID STATE PHYS, V3, P154 MADELUNG O, 1981, SPRINGER SERIES SOLI, V2, P270 MAJOR S, 1986, J MATER RES, V1, P300 MIYATA T, 2006, THIN SOLID FILMS, V496, P136 MOSADDEQURRAHMAN M, 1997, SOL ENERG MAT SOL C, V48, P123 MUSTAFA S, 2004, J COLLOID INTERF SCI, V275, P523 NAIR MTS, 1998, SEMICOND SCI TECH, V13, P1164 PELIZETTI E, 1983, ENERGY RESOURCES PHO, P173 RACHEVA TM, 1997, THIN SOLID FILMS, V292, P299 RADECKA M, 1993, APPL SURF SCI, V65, P227 SMITH RA, 1978, SEMICONDUCTORS+, P315 SU LY, 1997, THIN SOLID FILMS, V306, P133 TANG H, 1994, J APPL PHYS, V75, P2042 VASANELLI L, 1987, SOL ENERG MATER, V16, P91 WANG JY, 2005, SEMICOND SCI TECH, V20, L36 WARREN BE, 1990, XRAY DIFFRACTION, P251 WEIDMANN J, 1999, SOL ENERG MAT SOL C, V56, P153 ZAKRZEWSKA K, 1997, THIN SOLID FILMS, V310, P161 ZHANG DH, 1997, THIN SOLID FILMS, V295, P83 NR 42 TC 0 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0268-1242 J9 SEMICOND SCI TECHNOL JI Semicond. Sci. Technol. PD JUL PY 2007 VL 22 IS 7 BP 709 EP 716 PG 8 SC Engineering, Electrical & Electronic; Materials Science, Multidisciplinary; Physics, Condensed Matter GA 180XJ UT ISI:000247401000006 ER PT J AU Gonzalez-Rodriguez, JG Lucio-Garcia, MA Nicho, ME Cruz-Silva, R Casales, M Valenzuela, E AF Gonzalez-Rodriguez, J. G. Lucio-Garcia, M. A. Nicho, M. E. Cruz-Silva, R. Casales, M. Valenzuela, E. TI Improvement on the corrosion protection of conductive polymers in pemfc environmets by adhesives SO JOURNAL OF POWER SOURCES LA English DT Article DE conductive polymers; corrosion; sulfuric acid; fuel cells ID STAINLESS-STEEL; POLYPYRROLE; POLYANILINE; PYRROLE AB The corrosion protection of polypirrol (PPY) and polyaniline (PANI) coatings electrochemically deposited with and without polyvinil alcohol (PVA) as adhesive onto 304 type stainless steel has been evaluated using electrochemical techniques. Environment included 0.5 M H2SO4 at 60 degrees C whereas employed techniques included pothentiodynamic polarization curves (PQ, linear polarization resistance (LPR) and electrochemical impedance spectroscopy (EIS) measurements. Results showed that the free corrosion potential, of the substrate, E-corr, was made more noble up to 500 mV with the polymeric coatings. The corrosion rate was lowered by using the polymers, but with the addition of PVA, it was decreased further, one order of magnitude for PPY and up to three orders of magnitude for PANI. Impedance spectra showed that the corrosion mechanism is under a Warburgh-type diffussional process of the electrolyte throughout the coating, and that the uptake of the environment causes the eventual failure of the coating corroding the substrate. (C) 2007 Published by Elsevier B.V. C1 UAEM, CIICAP, Cuernavaca 62209, Morelos, Mexico. Univ Nacl Autonoma Mexico, Inst Ciencias Fis, Cuernavaca 62210, Morelos, Mexico. Univ Politecn Chiapas, Chiapas, Mexico. RP Gonzalez-Rodriguez, JG, UAEM, CIICAP, Av Univ 1001,Col Chamilpa, Cuernavaca 62209, Morelos, Mexico. EM ggonzalez@uaem.mx CR BECK F, 1994, ELECTROCHIM ACTA, V39, P229 DEBERRY DW, 1985, J ELECTROCHEM SOC, V132, P132 DIAZ AF, 1979, J CHEM SOC CHEM COMM, P635 HERMANN A, 2005, INT J HYDROGEN ENERG, V30, P1297 HERMAS AA, 2005, ELECTROCHIM ACTA, V50, P3640 HERRASTI P, 2001, APPL SURF SCI, V172, P276 HOEGER AJ, 2001, CURR APPL OPHYS, V1, P247 IVERSEN AK, 2006, CORROS SCI, V48 KAMAZAWA KK, 1979, J CHEM SOC CHEM COMM, P854 KOENE L, 2006, J APPL ELECTROCHEM, V36, P545 LUCIO MA, 2006, J POWER SOURCES, V158, P397 METHA V, 2003, J POWER SOURCES, V114, P32 NICHO ME, 2006, J APPL ELECTROCHEM, V36, P153 RAMMELT U, 2005, J APPL ELECTROCHEM, V35, P1225 STEARN M, 1958, J ELECTROCHEM SOC, V105, P638 TRIVEDI DC, 1997, HDB ORGANIC CONDUCTI, V2, P514 WESSLING B, 1994, ADV MATER, V6, P226 NR 17 TC 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0378-7753 J9 J POWER SOURCES JI J. Power Sources PD MAY 25 PY 2007 VL 168 IS 1 SI Sp. Iss. SI BP 184 EP 190 PG 7 SC Electrochemistry; Energy & Fuels GA 171OQ UT ISI:000246745700025 ER PT J AU Santoyo, E Garcia, R Galicia-Alanis, KA Verma, SP Aparicio, A Santoyo-Castelazo, A AF Santoyo, E. Garcia, R. Galicia-Alanis, K. A. Verma, S. P. Aparicio, A. Santoyo-Castelazo, A. TI Separation and quantification of lanthanides in synthetic standards by capillary electrophoresis: A new experimental evidence of the systematic "odd-even" pattern observed in sensitivities and detection limits SO JOURNAL OF CHROMATOGRAPHY A LA English DT Article DE UV-absorbance; rare earth elements; alpha-hydroxyisobutyric acid; chemometrics; metal complexes; indirect UV detection ID RARE-EARTH-ELEMENTS; PERFORMANCE LIQUID-CHROMATOGRAPHY; PLASMA-MASS SPECTROMETRY; ZONE-ELECTROPHORESIS; GEOLOGICAL SAMPLES; METAL-IONS; HPLC; UPDATE; PLANTS; ACID AB The systematic zigzag pattern of sensitivities and detection limits (LODs) of lanthanides, previously observed in mass spectrometric and chromatographic measurements, was once more investigated through the indirect photometric detection with capillary electrophoresis. Well-designed chemometric experiments were performed for the electrophoretic separation and detection of lanthanides using standards with similar concentrations. A fused silica capillary 355 mm x 75 mu m was used. Complete separation for all 14 lanthanides was achieved in similar to 3 min at a capillary temperature of 15 degrees C. Indirect photometric detection at 214 nm using a voltage of +25 kV and a hydrostatic injection (100 mm for 20 s) were used. The background electrolyte used consisted of an optimum mixture of 0.004M HIBA (as complexing agent) and 0.010M UVCat-1 (as a UV-absorbing co-ion) with a pH 4.4. A good reproducibility in migration times (< 2.7% RSD), peak areas (< 3.8% RSD) and peak heights (2.7% RSD) were systematically obtained. Calibration curves based on both peak areas and peak heights (from seven replicates) were prepared using weighted least-squares regressions, which were employed for the correct estimation of individual sensitivities and LODs. For a better estimation of LODs, the lowest concentration standard was injected 30 times. A new experimental evidence of the systematic "odd-even" pattern was again observed in the lanthanide sensitivities (and therefore in LODs). The calculated sensitivities were greater for lanthanides with an odd-atomic number than for their corresponding neighboring element with an even-atomic number (i.e., La-57-Ce-58; Pr-59-Nd-60; Eu-63-Gd-64, etc.). Concerning the LODs, a systematic zigzag pattern was observed where the odd atomic number elements have lower LODs than the even atomic number neighbor elements (i.e., La-57-Ce-58; Pr-59-Nd-60; Eu-63-Gd-64, etc.). The possible origin of this "odd-even" effect is briefly discussed. Accuracy errors were less than 5% for lanthanide concentrations of three synthetic standard solutions, which were considered as "unknown" samples. (c) 2007 Elsevier B.V. All rights reserved. C1 Univ Nacl Autonoma Mexico, Ctr Invest Energia, Temixco, Morelos, Mexico. CSIC, Museo Nacl Ciencias Nat, Dept Volcanol, E-28006 Madrid, Spain. Univ Nottingham, Sch Pharm, Ctr Analyt Biosci, Nottingham NG7 2RD, England. RP Santoyo, E, Univ Nacl Autonoma Mexico, Ctr Invest Energia, Priv Xochicalco,S-N,Col Ctr, Temixco, Morelos, Mexico. EM esg@cie.unam.mx CR *AM METH COMM, 1987, ANALYST, V112, P199 *IUPAC, 1978, SPECTROCHIM ACTA B, V33, P241 BACON JR, 2006, J ANAL ATOM SPECTROM, V21, P785 BETTINELLI M, 2005, ATOM SPECTROSC, V26, P41 BEVINGTON PR, 2003, DATA REDUCTION ERROR BUCHMEISER MR, 2000, ANAL CHEM, V72, P2595 BUCHMEISER MR, 2001, REV ANAL CHEM, V20, P161 CHURCH MN, 1998, ANAL CHEM, V70, P2475 FORET F, 1990, ELECTROPHORESIS, V11, P780 FRICKER SP, 2006, CHEM SOC REV, V35, P524 HALICZ L, 1996, J ANAL ATOM SPECTROM, V11, P811 HENDERSON P, 1984, RARE EARTH ELEMENT G HIROKAWA T, 2001, ELECTROPHORESIS, V22, P3483 JANOS P, 2003, ELECTROPHORESIS, V24, P1982 JOHNS C, 2003, J CHROMATOGR A, V997, P87 KAPLAN L, 1963, NUCL PHYS KULKARNI P, 2007, ANAL CHIM ACTA, V581, P247 LANDERS JP, 1997, HDB CAPILLARY ELECTR LIPSCHUTZ ME, 2001, ANAL CHEM, V73, P2687 LLOYD DK, 1995, J CHROMATOGR B, V663, P400 LONG GL, 1983, ANAL CHEM, V55, P713 MAO Q, 1998, J CHROMATOGR A, V802, P203 MAYER BX, 2001, J CHROMATOGR A, V907, P21 MILLER JN, 2000, STAT CHEMOMETRICS AN OZTEKIN N, 2000, J CHROMATOGR A, V895, P263 PEDREIRA WR, 2003, J SOLID STATE CHEM, V171, P3 RAO TP, 2000, CRIT REV ANAL CHEM, V30, P179 SAITO S, 2004, ANAL BIOANAL CHEM, V378, P1644 SAITO S, 2006, ELECTROPHORESIS, V27, P3093 SANTOYO E, 2003, J CHROMATOGR A, V997, P171 SANTOYO E, 2006, J CHROMATOGR A, V1118, P73 SHANNON RD, 1970, ACTA CRYSTALLOGR B, V26, P1046 SHI YC, 1993, J CHROMATOGR, V640, P473 SUN YL, 2006, ANAL SCI, V22, P551 THOMPSON M, 1998, ANALYST, V123, P405 TIMERBAEV AR, 2000, ELECTROPHORESIS, V21, P4179 TIMERBAEV AR, 2004, ELECTROPHORESIS, V25, P4008 TSAKANIKA LV, 2004, ANAL BIOANAL CHEM, V379, P796 VERMA SP, 2000, J CHROMATOGR A, V884, P317 VERMA SP, 2002, INT GEOL REV, V44, P287 VERMA SP, 2003, ANAL BIOANAL CHEM, V377, P82 VERMA SP, 2005, ACCREDIT QUAL ASSUR, V10, P144 VOGELGESANG J, 1998, ACCREDIT QUAL ASSUR, V3, P242 WEDEPHOL KH, 1971, GEOCHEMISTRY XU XK, 2003, PLANT SOIL, V252, P267 NR 45 TC 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0021-9673 J9 J CHROMATOGR A JI J. Chromatogr. A PD MAY 11 PY 2007 VL 1149 IS 1 BP 12 EP 19 PG 8 SC Biochemical Research Methods; Chemistry, Analytical GA 170YH UT ISI:000246701600003 ER PT J AU Romero-Vadillo, E Zaytsev, O Morales-Perez, R AF Romero-Vadillo, E. Zaytsev, O. Morales-Perez, R. TI Tropical cyclone statistics in the northeastern Pacific SO ATMOSFERA LA English DT Article DE tropical cyclone; Northeastern Pacific; hurricane track statistics ID EASTERLY WAVES; INTENSITIES; ATLANTIC; CYCLOGENESIS; VICINITY; SYSTEMS; HAWAII; OCEAN AB The principal area of tropical cyclogenesis in the tropical eastern Pacific Ocean is offshore in the Gulf of Tehuantepec, between 8 and 15 degrees N, and most of these cyclones move towards the west and northwest during their initial phase. Historical analysis of tropical cyclone data in the Northeastern (NE) Pacific over the last 38 years (from 1966 to 2004) shows a mean of 16.3 tropical cyclones per year, consisting of 8.8 hurricanes and 7.4 tropical storms. The analysis shows great geographical variability of cyclone tracks, and that there were a considerable number of hurricane strikes along the Mexican coast. About 50% of the tropical cyclones formed turned north to northeast. It was rare that any passed further north than 30 degrees N in latitude because of the cold California Current. Hurricane tracks that affected the NE Pacific may be separated into 5 groups. We compared the historical record of the sea surface temperature (SST), related with the El Nino events with a data set of tropical cyclones, including frequency, intensity, trajectory, and duration. Although the statistical dependence between the frequencies of tropical cyclones of the most abundant categories, 1 and 2, over this region and SST data was not convincing, the percentage of high intensity hurricanes and hurricanes with a long life-time (greater than 12 days) was more during El Nino years than in non-El Nino years. C1 Inst Politecn Nacl, Ctr Interdisciplinario Ciencias Marinas, La Paz 23096, Baja California, Mexico. Univ Autonoma Baja California, La Paz, Baja California, Mexico. IMTA, Yautepec, Morelos, Mexico. RP Zaytsev, O, Inst Politecn Nacl, Ctr Interdisciplinario Ciencias Marinas, La Paz 23096, Baja California, Mexico. EM ozaytsev@ipn.mx CR 2004, UNISYS CORPORATION W 2006, NOAA CLIMATE PREDICT *NOAA CIRES, 2006, CLIM DIAGN CTR WEB P AVILA LA, 1992, MON WEATHER REV, V120, P2688 CARLSON TN, 1969, MON WEA REV, V97, P716 CHU PS, 1997, J CLIMATE, V10, P2683 CHU PS, 1998, J APPL METEOROL, V37, P951 DEMARIA M, 1994, J CLIMATE, V7, P1324 EMERY WJ, 1997, DATA ANAL METHODS PH FLORES ZE, 1998, GEOSUDCALIFORNIA, P23 FULLER RD, 2000, MON WEATHER REV 2, V128, P2983 HOBGOOD JS, 1998, WEATHER FORECAST 2, V13, P632 HOLLAND GJ, 1993, J ATMOS SCI, V50, P1254 JAUREGUI E, 1981, 3 INT S URB EM, P1 MADDEN RA, 1994, MON WEATHER REV, V122, P814 MAGANA V, 1999, IMPACTOS NINO MEXICO, P23 MALONEY ED, 2000, J CLIMATE, V13, P451 MCBRIDE JL, 1981, J ATMOS SCI, V38, P1132 MOLINARI J, 1997, MON WEATHER REV, V125, P2699 MOLINARI J, 2000, MON WEATHER REV, V128, P3296 MONTGOMERY M, 1992, J ATMOS SCI, V50, P285 PEREZ E, 1998, EUR PHYS J B, V6, P1 RENARD R, 1976, 776 NAV PRED RES FAC, P113 ROSENDAL HE, 1962, MARINERS WEATHER LOG, V6, P195 SADLER JC, 1964, J APPL METEOROL, V3, P347 WHITNEY LD, 1997, J CLIMATE, V10, P2921 NR 26 TC 0 PU CENTRO CIENCIAS ATMOSFERA UNAM PI MEXICO CITY PA CIRCUITO EXTERIOR, MEXICO CITY CU 04510, MEXICO SN 0187-6236 J9 ATMOSFERA JI Atmosfera PD APR 1 PY 2007 VL 20 IS 2 BP 197 EP 213 PG 17 SC Meteorology & Atmospheric Sciences GA 169BY UT ISI:000246568900005 ER PT S AU Canto, GJ Figueroa, JV Ramos, JA Rojas, EE Garcia-Tapia, D Alvarez, JA Allred, DR Carson, CA AF Canto, Germinal J. Figueroa, Julio V. Ramos, Juan A. Rojas, Edmundo E. Garcia-Tapia, David Alvarez, J. Antonio Allred, David R. Carson, Charles A. TI Evaluation of cattle inoculated with Babesia bovis clones adhesive in vitro to bovine brain endothelial cells SO IMPACT OF EMERGING ZOONOTIC DISEASES ON ANIMAL HEALTH SE ANNALS OF THE NEW YORK ACADEMY OF SCIENCES LA English DT Article DE Babesia bovis; in vitro adhesive clones; in vivo assessment ID PLASMODIUM-FALCIPARUM; PERSISTENCE; INFECTIONS AB A comparative assessment of the virulence of Babesia bovis clones that adhere or not to bovine brain endothelial cells was done using two clones of B. bovis: (1) a clone phenotypically characterized as virulent (2F8) and (2) a clone of reduced virulence (RAD). Of these subpopulations, we selected those that had adhesive characteristics (a) or nonadhesive characteristics (na) in cultured endothelial cells. Twenty Holstein cattle, 12 months of age or older, were used in this study, and these cattle were randomly assigned to five groups of four animals each. The clones and their respective subpopulations were inoculated via intramuscular injection at a 0.5 X 10(7) infected erythrocyte dosage. Group A was inoculated with aRAD, group B with naRAD, group C with a2F8, group D with na2F8, and group E remained as a control. All inoculated animals showed a decrease in the packed cell volume (PCV), with group D showing the largest decrease (39.53%) and longest time (7 days) with rectal temperature above 39.5 degrees C. Babesia was observed in stained blood smears from only six cattle. While the four parasite subpopulations were pathogenic, significant differences were not noted among them, despite that the subpopulations considered to be virulent caused the greatest reduction in PCV per individual. C1 INIFAP, PAVET, CENID, Morelos 76280, Mexico. INIFAP, CENID, Morelos 62550, Mexico. Univ Missouri, Dept Vet Pathobiol, Columbia, MO 65211 USA. Univ Florida, Coll Vet Med, Dept Pathobiol, Gainesville, FL 32611 USA. RP Figueroa, JV, INIFAP, PAVET, CENID, Apartado Postal 206, Morelos 76280, Mexico. EM figueroa.julio@inifap.gob.inx CR ALLRED DR, 1995, PARASITOL TODAY, V11, P100 ALLRED DR, 2003, TRENDS PARASITOL, V19, P51 CALDER JAM, 1996, J CLIN MICROBIOL, V34, P2748 CALLOW L, 1963, AUST VET J, V39, P15 MAHONEY DF, 1973, ANN TROP MED PARASIT, V67, P197 MCCORD JM, 1998, OXIDAT STRESS DIS, V1, P1 MOLLOY JB, 2003, EXP PARASITOL, V103, P182 NEVILS MA, 2000, PARASITOL RES, V86, P437 OCONNOR RM, 1999, INFECT IMMUN, V67, P3921 OCONNOR RM, 2000, J IMMUNOL, V164, P2031 PALMER DA, 1982, PARASITOLOGY, V84, P567 WRIGHT IG, 1988, PARASITOL TODAY, V4, P214 NR 12 TC 1 PU BLACKWELL PUBLISHING PI OXFORD PA 9600 GARSINGTON RD, OXFORD OX4 2DQ, OXEN, ENGLAND SN 0077-8923 J9 ANN N Y ACAD SCI JI Ann.NY Acad.Sci. PY 2006 VL 1081 BP 397 EP 404 PG 8 SC Multidisciplinary Sciences GA BFZ67 UT ISI:000245654200054 ER PT J AU de Munoz, FGG Lanz-Mendoza, H Hernandez-Hernandez, FC AF Garcia-Gil de Munoz, F. Lanz-Mendoza, H. Hernandez-Hernandez, F. C. TI Free radical generation during the activation of hemolymph prepared from the homopteran Dactylopius coccus SO ARCHIVES OF INSECT BIOCHEMISTRY AND PHYSIOLOGY LA English DT Article DE Dactylopius coccus; free radicals; superoxide anion; nitric oxide; chromatocytes; hemolymph ID NITRIC-OXIDE; DROSOPHILA-MELANOGASTER; MELANOTIC ENCAPSULATION; CYTOTOXIC REACTIONS; SUPEROXIDE ANION; AROMATIC-AMINES; REACTIVE OXYGEN; INSECT; IMMUNITY; MELANOGENESIS AB Superoxide anion (O-2(-)) and nitric oxide (NO) generation in Dactylopius coccus hemolymph obtained by perfusion and activated with zymoson was studied. Activated hemolymph reduced 3-[4,5 dimethylthiazolil-2]-2,5-diphenyl tetrazolium bromide. This reduction was prevented by superoxide dismutase (SOD) indicating O-2(-) generation. This activity was dependent on temperature, and hemolymph incubated at 75 degrees C lost its activity. Chromatocytes incubated with zymoson released their content and produced O-2(-). Activated hemolymph also produced NO and this activity was prevented in the presence of NG-nitro-L-orginine methyl ester, suggesting that nitric oxide synthase (NOS) might be present in D. coccus hemolymph. The probable source of O-2(-) in the D. coccus hemolymph is the anthroquinone oxidation, since commercial carminic dye produced O-2(-) during its oxidation by Agoricus bisporus tytosinase. Gram + Microccus luteus exposed to activated hemolymph were killed in vitro, and addition of NG-nitro-L-arginine methyl ester and D-Mannitol (a hydroxyl radical scavenger) prevented their killing. The cytotoxic effect produced by the activated hemolymph was not observed with the Gram- bacteria Serratia marcescens. These results suggest that D. coccus activated hemolymph generates reactive oxygen intermediates (ROI) and reactive nitrogen intermediates (RNI) that may limit M. luteus growth. C1 Inst Nacl Salud Publ, Ctr Invest Enfermedades Infecc, Cuernavaca 62508, Morelos, Mexico. Inst Politecn Nacl, Ctr Invest & Estudios Avanzados, Dept Patol Expt, Mexico City 07360, DF, Mexico. Univ Simon Bolivar, Escuela Biol, Mexico City 03920, DF, Mexico. RP Lanz-Mendoza, H, Inst Nacl Salud Publ, Ctr Invest Enfermedades Infecc, Av Univ 655,Col Sta Maria Ahuacatitlan, Cuernavaca 62508, Morelos, Mexico. 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Insect Biochem. Physiol. PD MAY PY 2007 VL 65 IS 1 BP 20 EP 28 PG 9 SC Biochemistry & Molecular Biology; Entomology; Physiology GA 161XJ UT ISI:000246050000003 ER PT J AU Torres-Alvarado, IS Pandarinath, K Verma, SP Dulski, P AF Torres-Alvarado, Ignacio S. Pandarinath, Kailasa Verma, Surendra P. Dulski, Peter TI Mineralogical and geochemical effects due to hydrothermal alteration in the Los Azufres geothermal field, Mexico SO REVISTA MEXICANA DE CIENCIAS GEOLOGICAS LA English DT Article DE geothermal systems; element mobility; water-rock interaction; HFSE; REE; Los Azufres; Mexican Volcanic Belt; Mexico ID STRENGTH ELEMENTS; VOLCANIC-ROCKS; TRACE-ELEMENTS; REFERENCE SAMPLES; PB; EARTH; CLASSIFICATION; OPHIOLITE; COMPLEX; DEPOSIT AB To investigate the effects of hydrothermal alteration on the chemistry of volcanic rocks, we analyzed the whole rock chemical composition (major and trace elements, including rare-earth elements - REE) of two distinct portions of a drill well core sample from the Los Azufres geothermal field, Mexico. This highly hydrothermally-altered sample allowed us to study, for the first time, the mineralogical and chemical effects imposed by hydrothermal alteration on the mm scale in this important geothermal system. Mineralogically, hydrothermal alteration in the sample is mainly represented by chloritization of primary olivine and pyroxene, argillitization of primary plagioclase, as well as banded chlorite and quartz, with significant amounts of epidote and hematite. The "altered" part of the sample contains intensely altered remnants of the fresh rock, which show intense silicication, hematization, and dissolution boundaries. Most major and trace elements were mobilized from the original rock. Major element composition reflects the silicification, chloritization, and epidotization processes taking place in the geothermal system. The rare-earth elements La and Cc, as well as Yb and Lu were probably partially re-deposited during alteration. The positive anomaly ofEu may suggest that Eu is being concentrated in hydrothermal epidote after its release from plagioclase to the geothermal, fluid. The high field strength elements such as Zr, Ti, and P, show as well signficant hydrothermal alteration-related decrease in the highly-altered rock. The geothermal fluid responsible for this hydrothernaal alteration was probably oxidizing, of high temperature (> 250 degrees C), and enriched in REE and other trace elements. C1 Univ Nacl Autonoma Mexico, Ctr Invest Energia, Dept Sistemas Energet, Temixco 62580, Morelos, Mexico. Geoforschungszentrum Potsdam, D-14473 Potsdam, Germany. RP Torres-Alvarado, IS, Univ Nacl Autonoma Mexico, Ctr Invest Energia, Dept Sistemas Energet, Priv Xochicalco S-N,Col Ctr,Apartado Postal 34, Temixco 62580, Morelos, Mexico. 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Mex. Cienc. Geol. PD APR PY 2006 VL 24 IS 1 BP 15 EP 24 PG 10 SC Geosciences, Multidisciplinary GA 158GP UT ISI:000245780000002 ER PT J AU Santos-Contreras, RJ Martinez-Martinez, FJ Garcia-Baez, EV Padilla-Martinez, II Peraza, AL Hopfl, H AF Santos-Contreras, Rocio J. Martinez-Martinez, Francisco J. Garcia-Baez, Efren V. Padilla-Martinez, Itzia I. Peraza, Ana L. Hopfl, Herbert TI Carbonyl-carbonyl, carbonyl-pi and carbonyl-halogen dipolar interactions as the directing motifs of the supramolecular structure of ethyl 6-chloro-2-oxo-2H-chromene-3-carboxylate and ethyl 6-bromo-2-oxo-2H-chromene-3-carboxylate SO ACTA CRYSTALLOGRAPHICA SECTION C-CRYSTAL STRUCTURE COMMUNICATIONS LA English DT Article ID COUMARIN DERIVATIVES; CRYSTAL-STRUCTURES; DATABASE; GEOMETRY; BONDS AB The title compounds, C12H9ClO4, (I), and C12H9BrO4, (II), are isomorphous and crystallize in the monoclinic space group P2(1)/c. Both compounds present an anti conformation between the 3-carboxy and the lactone carbonyl groups. Both carbonyl groups are out of the plane defined by the remaining chromene atoms, by 8.37 (6) and 17.57 (6)degrees for ( I), and by 9.07 (8) and 18.96 (18)degrees for (II), owing to their involvement in intermolecular interactions. In both compounds, layers of centrosymmetric hydrogen- bonded dimers are developed in the [5222] plane through C-(HO)-O-... interactions, involving both carbonyl groups as acceptors. Two families of dimers stack through C=(OC)-C-...=O, C=O-...pi and C - (XC)-C-...=O (X = Cl and Br) dipolar interactions, as well as a C-H-...pi interaction, developing the three- dimensional structure along the c axis. C1 Inst Politecn Nacl, Unidad Profes Interdisciplinaria Biotecnol, Barrio La Laguna Ticoman 07340, DF, Mexico. Univ Colima, Fac Ciencias Quim, Colima 28400, Mexico. Univ Autonoma Estado Morelos, Ctr Invest Quim, Cuernavaca 62210, Morelos, Mexico. RP Padilla-Martinez, II, Inst Politecn Nacl, Unidad Profes Interdisciplinaria Biotecnol, Ave Acueducto SN, Barrio La Laguna Ticoman 07340, DF, Mexico. EM ipadilla@acei.upibi.ipn.mx CR *BRUK, 2002, SMART SAINT ALLEN FH, 1998, ACTA CRYSTALLOGR B 3, V54, P320 ALLEN FH, 2002, ACTA CRYSTALLOGR B 3, V58, P380 AUFFINGER P, 2004, P NATL ACAD SCI USA, V101, P16789 BERNSTEIN J, 1995, ANGEW CHEM INT EDIT, V34, P1555 BONDI A, 1964, J PHYS CHEM-US, V68, P441 BONSIGNORE L, 1995, J HETEROCYCLIC CHEM, V32, P573 BOSCH E, 2002, CRYST GROWTH DES, V2, P299 BRUNO IJ, 2002, ACTA CRYSTALLOGR B 3, V58, P389 CHIMENTI F, 2004, BIOORG MED CHEM LETT, V14, P3697 FARRUGIA LJ, 1999, J APPL CRYSTALLOGR, V32, P837 FUJII I, 2005, ACTA CRYSTALLOGR E 5, V61, O1456 GARCIABAEZ EV, 2003, CRYST GROWTH DES, V3, P35 GNANAGURU K, 1985, J ORG CHEM, V50, P2337 GURSOY A, 2003, TURK J CHEM, V27, P545 KONTOGIORGIS CA, 2005, J MED CHEM, V48, P6400 LACY A, 2004, CURR PHARM DESIGN, V10, P3797 LEE KH, 1999, PURE APPL CHEM, V71, P1045 LOMMERSE JPM, 1996, J AM CHEM SOC, V118, P3108 MAGANAVERGARA NE, 2004, ACTA CRYSTALLOGR 12, V60, O2306 MARCHI AA, 2004, BIOORGAN MED CHEM, V12, P4823 OUVRARD C, 2003, ACTA CRYSTALLOGR B 4, V59, P512 SANTANA L, 2006, J MED CHEM, V49, P1149 SHELDRICK GM, 1996, SADABS SHELDRICK GM, 1997, SHELXS97 SHELXL97 UMEZAWA Y, 1998, B CHEM SOC JPN, V71, P1207 NR 26 TC 0 PU BLACKWELL PUBLISHING PI OXFORD PA 9600 GARSINGTON RD, OXFORD OX4 2DQ, OXON, ENGLAND SN 0108-2701 J9 ACTA CRYSTALLOGR C-CRYST STR JI Acta Crystallogr. Sect. C-Cryst. Struct. Commun. PD APR PY 2007 VL 63 PN Part 4 BP O239 EP O242 PG 4 SC Crystallography GA 153WZ UT ISI:000245469800029 ER PT J AU Diaz-Rodriguez, G Reyes-Morales, H Lopez-Caudana, AE AF Diaz-Rodriguez, Gustavo Reyes-Morales, Hortensia Ethelia Lopez-Caudana, Alma TI Validation of a clinimetric scale for the diagnosis for depression in patients with diabetes mellitus type 2, in primary healt care SO REVISTA DE INVESTIGACION CLINICA LA Spanish DT Article DE depression; diabetes mellitus; scale for the diagnosis of depression (CSDD); composite international diagnostic interview (CIDI); primary care ID COMORBID DEPRESSION; PREVALENCE; GUIDELINES; PHYSICIANS; DISORDERS; INVENTORY; MEXICO AB Background. The prevalence of depression in patients with type 2 diabetes mellitus (DM2) is of up to 49.3% in primary care clinics. Nevertheless, medical doctors only recognize only 30% of these cases. Depression is associated with poor glycemic control, increase of diabetes complications, deterioration in patient's quality of life, and increase in demand and resources to provide care. The objective was to design and validate a clinimetric scale for the diagnosis of depression (CSDD in patients with DM2, in primary care units. Patients and methods. The study was conducted on 528 DM2 patients in Family Medicine Unit No. 10 of the Instituto Mexicano del Seguro Social (Mexican Social Security Institute), during 2003. A diagnostic test design was employed, with the golden standard consisting of the composite international diagnostic interview. Samples were constructed around consecutive cases. Depression and its degrees were the dependent variables. Absolute and relative frequencies were calculated, along with the Kappa index, sensibility, specificity, positive predictive values (PPV) and negative predictive values (NPV) and ROC curves. Results. The CSDD presented a concordance between observers of 0.7739. The best cut-off point in the ROC curves for diagnosis of depression was 6, which obtained a sensibility of 95.3%, a specificity of 96.8%, a PPV of 92.2%, and a NPV of 98.1%. Conclusions. The CSDD is a consistent and valid instrument and easy to use for the diagnosis of depression in patients with DM2 in primary care clinic. C1 Inst Mexicano Selguro Social, Direcc Prestac Med, Mexico City 06600, DF, Mexico. Inst Mexicano Seguro Social, Hosp Gen Reg Med Familiar T Lic Ignacio Garcia Te, Cuernavaca, Morelos, Mexico. RP Diaz-Rodriguez, G, Inst Mexicano Selguro Social, Direcc Prestac Med, Reforma 476,3er Piso, Mexico City 06600, DF, Mexico. 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Invest. Clin. PD SEP-OCT PY 2006 VL 58 IS 5 BP 432 EP 440 PG 9 SC Medicine, General & Internal GA 149YT UT ISI:000245183500003 ER PT J AU Islas-Flores, I Villanueva, MA AF Islas-Flores, Ignacio Villanueva, Marco A. TI Inositol-1 (or 4)-monophosphatase from Glycine max embryo axes is a phosphatase with broad substrate specificity that includes phytate dephosphorylation SO BIOCHIMICA ET BIOPHYSICA ACTA-GENERAL SUBJECTS LA English DT Article DE germination; Glycine max; IMPase; seeds; phosphatase; phytate ID MYOINOSITOL MONOPHOSPHATASE; INORGANIC PYROPHOSPHATASE; PHASEOLUS-VULGARIS; PLANTS; EXPRESSION; CYCLIN; ENZYME; GENES; ACID; PURIFICATION AB A phosphate-hydrolyzing activity from Glycine max embryo axes was purified by a series of chromatographic steps and electroelution from activity gels, and demonstrated to be an inositol-1 (or 4)-monophosphatase by partial internal amino acid sequence. This enzyme hydrolyzed ATP, sodium pyrophosphate (NaPPi), mositol hexakisphosphate, and inositol 1-monophosphate, but not p-nitrophenyl phosphate, ADP, AMP or glucose 6-P. Using NaPPi as substrate, the highly purified protein hydrolyzed up to 0.4 mmol phosphate min(-1) mg(-1) protein and had a Km(avg) of 235 mu M for NaPPi. Since NaPPi is relatively inexpensive and readily available, we used this as substrate for the subsequent characterization. We observed the following: (a) specific inhibition by Li and NaF but not by butanedione monoxime, or orthovanadate; (b) activation by Cu2+ and Mg2+; (c) optimum activity at pH 7.4; and (d) temperature stability after 1-h incubations at 37-80 degrees C, with maximum activity at 37 degrees C. The partially purified protein was detected by in-gel activity assays and the band was electroeluted to yield a highly purified protein. Analysis by SDS-PAGE and native IEF-PAGE yielded a single major polypeptide of 29 kDa and pI similar to 5.9, respectively. In addition, in-gel activity from embryo axes and whole hypocotyls at early germination times revealed one high and one intermediate molecular weight isoforrn, but only the intermediate one corresponded to IMPase. Throughout the post-imbibition period, the activity of the high molecular weight isoform disappeared and IMPase increased, indicating an increasing expression of the enzyme as germination and growth proceeded. These data indicate that the inositol-1 (or 4)monophosphatase present in the embryo axis of G. max has a wide phosphate substrate specificity, and may play an important role in phosphate metabolism during the germination process. (c) 2006 Elsevier B.V. All rights reserved. C1 Univ Nacl Autonoma Mexico, Inst Biotecnol, Dept Biol Mol Plantas, Cuernavaca 62250, Morelos, Mexico. RP Villanueva, MA, Univ Nacl Autonoma Mexico, Unidad Acad Puerto Morelos, Inst Ciencias Mar & Limnol, Av Ninos Heroes S-N, Puerto Morelos 77580, Quintana Roo, Mexico. 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Biophys. Acta-Gen. Subj. PD APR PY 2007 VL 1770 IS 4 BP 543 EP 550 PG 8 SC Biochemistry & Molecular Biology; Biophysics GA 149SC UT ISI:000245165900005 ER PT J AU Trujillo-Jimenez, P Viveros, EED AF Trujillo-Jimenez, Patricia de los Monteros Viveros, Efren Espinosa TI The feeding ecology of the endemic fish Girardinichthys multiradiatus (Cyprinidontiformes : Goodeidae) in Lagunas of Zempoala National Park, Mexico. SO REVISTA DE BIOLOGIA TROPICAL LA Spanish DT Article DE Goodeidae; Girardinichthys multiradiatus; Zempoala; feeding ecology; carnivorous ID GAMBUSIA-AFFINIS; NICHE AB Girardinichthys multiradiatus, locally known as "mexcalpique", is a small endemic fish of the Lerma river basin. Its presence in lakes (Zempoala) suggests a long-standing connection between these lakes and the river basin. The current range of this species in the Mexico and Toluca valley appears to have been reduced, making this park a refuge for the species. Nevertheless, little is known about its biology. We studied its diet and feeding habits in Acoyotongo Lake, Lagunas de Zempoala National Park (19 degrees 01'30"-19 degrees 06' N, 99 degrees 16'20"-99 degrees 21' W) where seasonal collections were carried out. The gut contents of 97 specimens were identified to the most specific taxonomic category possible and analyzed with numeric and frequency of occurrence methods. The general diet of this species consists of twelve dietary components, eleven of which are of animal origin. Hymenopterans, springtails and chironomids represented the highest percentage of ingestion and preference. G. multiradiatus is as a carnivorous species with entomophagous tendencies. C1 Univ Autonoma Estado Morelos, Ctr Invest Biol, Cuernavaca 62210, Morelos, Mexico. RP Trujillo-Jimenez, P, Univ Autonoma Estado Morelos, Ctr Invest Biol, Av Univ 1001 Col Chamilpa, Cuernavaca 62210, Morelos, Mexico. EM trujill@cib.uaem.mx CR ALBERTINIBERHAU.J, 1973, AQUACULTURE, V2, P251 ALLAN JD, 1995, STREAM ECOLOGY STRUC BARRAGAN J, 1994, ZOOL INF IPN, V28, P27 BLAND RG, 1979, KNOW IMMATURE INSECT BONILLABARBOSA J, 1997, LISTADOS FLORISTICOS, V14 CHU HF, 1979, IMMATURE INSECTS DANIELS GL, 1992, SOUTHWEST NAT, V37, P157 DUARTE SP, 1981, THESIS ESCUELA NACL GERKING DS, 1994, FEEDING ECOLOGY FISH GODINEZ RMA, 1989, THESIS ESCUELA NACL HESS AD, 1942, AM J HYG, V35, P142 HOLBROOK SJ, 1988, ECOLOGY, V69, P125 KREBS JCH, 1999, ECOLOICAL METHODOLOG LAGLER KF, 1977, FRESHWATER FISHERY B LIVINGSTON RJ, 1982, MAR ECOL-PROG SER, V7, P1 LUDWING JA, 1988, STAT ECOLOGY MACARTHUR RH, 1967, AM NAT, V101, P377 MCCAFFERTY WP, 1983, AQUATIC ENTOMOLOGY NEEDHAM JG, 1979, GUIA ESTUDIO SERES V PAULOMAYA J, 2000, REV BIOL TROP, V48, P465 PENNAK K, 1978, FRESHWATER INVERTEBR ROSS ST, 1978, FISHERY B, V76, P225 ROSS ST, 1986, COPEIA, P352 SOTOGALERA E, 1995, ZOOL INFORMA ESC NAC, V31, P5 TOLEDO BH, 1996, THESIS FACULTAD CIEN TRUJILLO JP, 1998, THESIS UNAM MEXICO TRUJILLOJIMENEZ P, 1996, REV BIOL TROP, V44, P755 WERNER EE, 1976, SCIENCE, V191, P404 WERNER EE, 1984, ANNU REV ECOL SYST, V15, P393 WINDELL JT, 1978, METHODS ASSESSMENT F, P219 WOOTTON RJ, 1990, ECOLOGY TELEOST FISH ZARET TM, 1971, ECOLOGY, V52, P336 NR 32 TC 0 PU REVISTA DE BIOLOGIA TROPICAL PI SAN JOSE PA UNIVERSIDAD DE COSTA RICA CIUDAD UNIVERSITARIA, SAN JOSE, COSTA RICA SN 0034-7744 J9 REV BIOL TROP JI Rev. Biol. Trop. PD DEC PY 2006 VL 54 IS 4 BP 1247 EP 1255 PG 9 SC Biology GA 143ON UT ISI:000244732200023 ER PT J AU Lovy-Wheeler, A Cardenas, L Kunkel, JG Hepler, PK AF Lovy-Wheeler, Alenka Cardenas, Luis Kunkel, Joseph G. Hepler, Peter K. TI Differential organelle movement on the actin cytoskeleton in lily pollen tubes SO CELL MOTILITY AND THE CYTOSKELETON LA English DT Article DE endoplasmic reticulum; mitochondria; vacuole; actin; myosin ID GREEN FLUORESCENT PROTEIN; ENDOPLASMIC-RETICULUM; TIP GROWTH; MYOSIN-V; LILIUM-LONGIFLORUM; PLANT-CELLS; F-ACTIN; 3-DIMENSIONAL RECONSTRUCTION; TRANSVACUOLAR STRAND; ARABIDOPSIS-THALIANA AB We have examined the arrangement and movement of three major compartments, the endoplasmic reticulum (ER), mitochondria, and the vacuole during oscillatory, polarized growth in lily pollen tubes. These movements are dependent on the actin cytoskeleton, because they are strongly perturbed by the anti-microfilament drug, latrunculin-B, and unaffected by the anti-microtubule agent, oryzalin. The ER, which has been labeled with mGFP5-HDEL or cytochalasin D tetramethylrhodamine, displays an oscillatory motion in the pollen tube apex. First it moves apically in the cortical region, presumably along the cortical actin fringe, and then periodically folds inward creating a platform that transects the apical domain in a plate-like structure. Finally, the ER reverses its direction and moves basipetally through the central core of the pollen tube. When subjected to cross-correlation analysis, the formation of the platform precedes maximal growth rates by an average of 3 s (35-40 degrees). Mitochondria, labeled with Mitotracker Green, are enriched in the subapical region, and their movement closely resembles that of the ER. The vacuole, labeled with carboxy-dichlorofluorescein diacetate, consists of thin tubules arranged longitudinally in a reticulate network, which undergoes active motion. In contrast to the mitochondria and ER, the vacuole is located back from the apex, and never extends into the apical clear zone. We have not been able to decipher an oscillatory pattern in vacuole motion. Because this motion is dependent on actin and not tubulin, we think this is due to a different myosin from that which drives the ER and mitochondria. C1 Univ Massachusetts, Morrill Sci Ctr 3, Dept Biol, Amherst, MA 01003 USA. Univ Massachusetts, Morrill Sci Ctr 3, Plant Biol Grad Program, Amherst, MA 01003 USA. Inst Biotechnol, Dept Biol Mol Plantas, Cuernavaca, Morelos, Mexico. RP Hepler, PK, Univ Massachusetts, Morrill Sci Ctr 3, Dept Biol, 611 N Pleasant St, Amherst, MA 01003 USA. EM hepler@bio.umass.edu CR BOEVINK P, 1998, PLANT J, V15, P441 BRILLINGER D, 1981, TIME SERIES DATA ANA CAI G, 2006, POLLEN TUBE CELLULAR, P157 CARDENAS L, 2005, CELL MOTIL CYTOSKEL, V61, P112 CARDENAS L, 2006, PLANT PHYSIOL, V142, P1460 CHEUNG AY, 2002, PLANT CELL, V14, P945 CLEVELAND WS, 1981, AM STAT, V35, P54 COLLINGS DA, 2003, PLANTA, V218, P204 DERKSEN J, 1985, EUR J CELL BIOL, V38, P142 DERKSEN J, 1995, ACTA BOT NEERL, V44, P93 DEWIN AHN, 1999, BIOPHYS J, V76, P1648 ESTRADA P, 2003, J CELL BIOL, V163, P1255 FOISSNER I, 2002, PROTOPLASMA, V220, P1 FU Y, 2001, J CELL BIOL, V152, P1019 GEITMANN A, 2000, J MICROSC-OXFORD 3, V198, P218 GIBBON BC, 1999, PLANT CELL, V11, P2349 GU Y, 2005, J CELL BIOL, V169, P127 HASELOFF J, 1997, P NATL ACAD SCI USA, V94, P2122 HASHIMOTO K, 2005, PLANT CELL PHYSIOL, V46, P782 HEPLER PK, 2001, ANNU REV CELL DEV BI, V17, P159 HESLOPHARRISON J, 1988, J CELL SCI 1, V91, P49 HESLOPHARRISON J, 1990, SEX PLANT REPROD, V3, P187 HICKS GR, 2004, PLANT PHYSIOL, V134, P1227 HOLDAWAYCLARKE TL, 1997, PLANT CELL, V9, P1999 HOLDAWAYCLARKE TL, 2003, NEW PHYTOL, V159, P539 HOLWEG C, 2004, P NATL ACAD SCI USA, V101, P10488 HUANG SJ, 2004, J BIOL CHEM, V279, P23364 HWANG JU, 2005, MOL BIOL CELL, V16, P5385 ISHIKAWA K, 2003, J CELL BIOL, V160, P887 JOOS U, 1994, PROTOPLASMA, V179, P5 KETELAAR T, 2004, PLANT PHYSIOL, V136, P3990 KIM H, 2005, PLANT CELL, V17, P888 KINKEMA M, 1994, PLANT MOL BIOL, V26, P1139 KURODA K, 1990, INT REV CYTOL, V121, P267 KUTSUNA N, 2003, PLANT CELL PHYSIOL, V44, P1045 KUTSUNA N, 2005, MICROSC RES TECHNIQ, V68, P296 LANCELLE SA, 1986, PROTOPLASMA, V131, P153 LANCELLE SA, 1992, PROTOPLASMA, V167, P215 LEVINE T, 2005, CURR OPIN CELL BIOL, V17, P362 LICHTSCHEIDL IK, 1990, PROTOPLASMA, V155, P116 LIEBE S, 1995, BIOL CELL, V85, P207 LOVYWHEELER A, 2005, PLANTA, V221, P95 LOVYWHEELER A, 2006, PLANT CELL, V18, P1 MAINDONALD J, 2003, DATA ANAL GRAPHICS U MANO S, 2002, PLANT CELL PHYSIOL, V43, P331 MESSERLI M, 1997, J CELL SCI 11, V110, P1269 MESSERLI MA, 2000, DEV BIOL, V222, P84 MILLER DD, 1995, J CELL SCI 7, V108, P2549 NEBENFUHR A, 1999, PLANT PHYSIOL, V121, P1127 PARTON RM, 2003, J CELL SCI, V116, P2707 PASHKOVA N, 2005, J CELL BIOL, V168, P359 PIERSON ES, 1996, DEV BIOL, V174, P160 REDDY AS, 2001, GENOME BIOL, V2 RUNIONS J, 2006, J EXP BOT, V57, P43 RUTHARDT N, 2005, PROTOPLASMA, V225, P205 SHIMMEN T, 2004, CURR OPIN CELL BIOL, V16, P68 SOLOVYOVA N, 2002, J NEUROSCI METH, V122, P1 STAEHELIN LA, 1997, PLANT J, V11, P1151 STEER MW, 1989, NEW PHYTOL, V111, P323 STEER MW, 1990, TIP GROWTH PLANT FUN, P119 TABB JS, 1998, J CELL SCI 21, V111, P3221 TOMINAGA M, 2000, PLANTA, V210, P836 VANGESTEL K, 2002, J EXP BOT, V53, P659 VIDALI L, 2001, MOL BIOL CELL, V12, P2534 VIDALI L, 2001, PROTOPLASMA, V215, P64 WANG ZY, 2004, CELL MOTIL CYTOSKEL, V57, P218 WILLIAMSON RE, 1993, ANNU REV PLANT PHYS, V44, P181 WILSEN KL, 2005, MONITORING ACTIN CYT WILSEN KL, 2006, SEX PLANT REPROD, V19, P51 WOLLERT T, 2002, J CELL BIOL, V159, P571 YOKOTA E, 1995, PROTOPLASMA, V185, P178 YOKOTA E, 1999, PLANT PHYSIOL, V119, P231 NR 72 TC 0 PU WILEY-LISS PI HOBOKEN PA DIV JOHN WILEY & SONS INC, 111 RIVER ST, HOBOKEN, NJ 07030 USA SN 0886-1544 J9 CELL MOTILITY CYTOSKEL JI Cell Motil. Cytoskeleton PD MAR PY 2007 VL 64 IS 3 BP 217 EP 232 PG 16 SC Cell Biology GA 138RE UT ISI:000244379200006 ER PT J AU Villamizar, W Casales, M Gonzalez-Rodriguez, JG Martinez, L AF Villamizar, W. Casales, M. Gonzalez-Rodriguez, J. G. Martinez, L. TI CO2 corrosion inhibition by hydroxyethyl, aminoethyl, and amidoethyl imidazolines in water-oil mixtures SO JOURNAL OF SOLID STATE ELECTROCHEMISTRY LA English DT Article DE CO2 corrosion; imidazolines; diesel; electrochemical techniques ID CARBON-DIOXIDE CORROSION; MILD-STEEL; MOLECULAR-STRUCTURE; MEDIA AB The corrosion behavior of hydroxyethyl, amino ethyl and amid ethyl imidazolines corrosion inhibitors was evaluated by using potenthiodynamic polarization curves, linear polarization resistance, and electrochemical impedance spectroscopy techniques. Solutions included deaerated 3% NaCl, 3% NaCl+diesel saturated with CO2 at 50 degrees C with and without inhibitors. Regardless of the presence of diesel, the corrosion rate was decreased with the addition of the inhibitors, but the time to reach a steady state was longer than when the oily part, i.e., diesel, was present. In the absence of the oily part, the impedance results showed that the film formed was porous, allowing the electrolyte to diffuse through it and corrode the metal. When the oily part was present, the film formed was much more stable, not porous, and did not allow the electrolyte to corrode the sample. The most efficient inhibitor was the amid ethyl imidazoline, whereas the least efficient was the hydroxyethyl imidazoline, because the film formed by the former was much more stable from the beginning of the test. C1 UAEM, CIICAp, Cuernavaca 62210, Morelos, Mexico. UNAM, Ctr Ciencias Fis, Cuernavaca 62210, Morelos, Mexico. RP Gonzalez-Rodriguez, JG, UAEM, CIICAp, Av Univ 1001,Col Chamilpa, Cuernavaca 62210, Morelos, Mexico. EM ggonzalez@uaem.mx CR BENTISS F, 1999, CORROS SCI, V41, P789 BENTISS F, 2001, J APPL ELECTROCHEM, V31, P449 BILKOVA K, 2002, P NACE CORR 2002 DEN CRUZ J, 2001, INT J QUANTUM CHEM, V85, P1911 CRUZ J, 2004, J ELECTROANAL CHEM, V566, P111 DEMORALES FD, 2000, P NACE CORR 2000 ORL JOVANCICEVIC V, 1999, CORROSION, V55, P449 KERMANI MB, 2003, CORROSION, V59, P659 MACDONALD JR, 1987, J ELECTROANAL CH INF, V223, P25 RAMACHANDRAN S, 1996, LANGMUIR, V12, P6419 RAMACHANDRAN S, 1999, CORROSION, V55, P259 RODRIGUEZVALDEZ LM, 2004, J MOL STRUC-THEOCHEM, V681, P83 RODRIGUEZVALDEZ LM, 2005, J MOL STRUC-THEOCHEM, V713, P65 WALTER GW, 1986, CORROS SCI, V26, P681 WANG D, 1999, CORROS SCI, V49, P911 XUEYUAN Z, 2001, CORROS SCI, V43, P1417 NR 16 TC 0 PU SPRINGER PI NEW YORK PA 233 SPRING STREET, NEW YORK, NY 10013 USA SN 1432-8488 J9 J SOLID STATE ELECTROCHEM JI J. Solid State Electrochem. PD MAY PY 2007 VL 11 IS 5 BP 619 EP 629 PG 11 SC Electrochemistry GA 136CE UT ISI:000244199400008 ER PT J AU Ramirez, EB Huanosta, A Sebastian, JP Huerta, L Ortiz, A Alonso, JC AF Ramirez, E. B. Huanosta, A. Sebastian, J. P. Huerta, L. Ortiz, A. Alonso, J. C. TI Structure, composition and electrical properties of YSZ films deposited by ultrasonic spray pyrolysis SO JOURNAL OF MATERIALS SCIENCE LA English DT Article ID YTTRIA-STABILIZED ZIRCONIA; OXIDE FUEL-CELLS; THIN-FILMS; ELECTROLYTE FILMS; IONIC-CONDUCTIVITY; SILICON; PHASE AB Yttria-stabilized zirconia (YSZ) films with different yttria concentrations were prepared by ultrasonic spray pyrolysis on Si substrates at 525 degrees C, using solutions of zirconium and yttrium acetylacetonates in methanol. The chemical composition, structure and electrical properties of the films were studied by X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), and electrochemical impedance spectroscopy (EIS). XPS measurements show that the Y content in the films increases as the Y precursor in the solution increases. Carbon incorporation was also found in the films, although the concentration of this impurity was reduced as the incorporation of Y increased. XRD spectra show that the Zr1-x Y (x) O2-x/2 polycrystalline films have the cubic phase of ZrO2 and fully stabilized 8YSZ (8 at.% Y2O3 + 92 at.% ZrO2), and that their lattice constant increases slightly as the Y content increases. The conductivity of all the as-deposited films as a function of temperature, showed an Arrhenius behavior, and with the exception of the film with the maximum Y content, the activation energies were in the range of 0.98-1.11 eV. The ionic conductivity of one of these films was similar to that measured for a pellet made of the 8YSZ standard powder. C1 Univ Nacl Autonoma Mexico, Inst Invest Mat, Mexico City 04510, DF, Mexico. Univ Nacl Autonoma Mexico, Ctr Invest Energia, Temixco 62580, Morelos, Mexico. RP Alonso, JC, Univ Nacl Autonoma Mexico, Inst Invest Mat, Ciudad Univ, Mexico City 04510, DF, Mexico. EM alonso@servidor.unam.mx CR BAO WT, 2005, SOLID STATE IONICS, V176, P669 BARTOLOME JF, 2004, J AM CERAM SOC, V87, P2282 BOULCH F, 2002, SOLID STATE IONICS B, V154, P143 CATANEDA L, 2002, MATER CHEM PHYS, V77, P938 CHEVALIER S, 2003, APPL SURF SCI, V205, P188 CHIODELLI G, 1988, J MATER SCI, V23, P1159 DIBARTOLOMEO E, 2004, SOLID STATE IONICS, V171, P173 HAERING C, 2005, SOLID STATE IONICS, V176, P253 HARTMANOVA M, 1998, J MATER SCI, V33, P969 HUGHES AE, 1989, J MATER SCI, V24, P1057 JIANG SP, 1997, KEY ENG MATER, V125, P133 KEIJSER TH, 1982, J APPL CRYSTALLOGR, V15, P308 KOSACKI I, 2005, SOLID STATE IONICS, V176, P1319 KOZHUKHAROV V, 2002, BOL SOC ESP CERAM V, V41, P471 LANGLET M, 1993, CHEM ADV MAT, P55 MENG GY, 2004, SOLID STATE IONICS, V175, P29 MINH NQ, 1993, J AM CERAM SOC, V76, P563 MORI T, 2002, SOLID STATE IONICS B, V154, P529 NASIBULIN AG, 2005, COLLOID J+, V67, P1 ORTIZ A, 2001, J ELECTROCHEM SOC, V148, F26 ORTIZ A, 2002, J MATER SCI-MATER EL, V13, P7 ORTIZ A, 2005, J ELECTRON MATER, V34, P150 PEREDNIS D, 2004, SOLID STATE IONICS, V166, P229 RALPH JM, 2001, J MATER SCI, V36, P1161 RUDDELL DE, 2003, THIN SOLID FILMS, V445, P14 VALVODA V, 1992, DIAGNOSTICS APPL THI, P115 WANG SJ, 2002, APPL PHYS LETT, V80, P2541 WANZENBERG E, 2003, SOLID STATE IONICS, V159, P1 WANZENBERG E, 2003, SOLID STATE IONICS, V164, P121 WILL J, 2000, SOLID STATE IONICS, V131, P79 YAMAMOTO O, 1995, SOLID STATE IONICS, V79, P137 ZHANG NL, 2002, APPL SURF SCI, V202, P126 NR 32 TC 0 PU SPRINGER PI NEW YORK PA 233 SPRING STREET, NEW YORK, NY 10013 USA SN 0022-2461 J9 J MATER SCI JI J. Mater. Sci. PD FEB PY 2007 VL 42 IS 3 BP 901 EP 907 PG 7 SC Materials Science, Multidisciplinary GA 136BW UT ISI:000244198600025 ER PT J AU Gonzalez-Soto, RA Mora-Escobedo, R Hernandez-Sanchez, H Sanchez-Rivera, M Bello-Perez, LA AF Gonzalez-Soto, R. A. Mora-Escobedo, R. Hernandez-Sanchez, H. Sanchez-Rivera, M. Bello-Perez, L. A. TI The influence of time and storage temperature on resistant starch formation from autoclaved debranched banana starch SO FOOD RESEARCH INTERNATIONAL LA English DT Article DE banana starch; resistant starch; autoclaving; functional properties; x-ray diffraction ID SMALL-INTESTINE; DIGESTION; RAW AB Debranching and autoclaving processes of banana starch were carried out for obtaining a resistant starch-rich powder with functional characteristics. Debranching was carried out using pullulanase for 24 h and the autoclaving was done at 121 degrees C for 30 min, the samples were then cooled down and stored between 24 and 48 h, and temperatures between 4 and 60 degrees C. The resistant starch level increased due to the debranching and autoclaving processes. The water absorption index values decreased when the storage time increased, pattern that agrees with the higher RS content. The water solubility index (WSI) was affected by the storage temperature but not by the storage time. The autoclaved sample was hydrolyzed to a lesser extent than native starch. The RS-rich powder presented also crystallinity because the process of autoclaving and storage induced starch retrogradation. The procedure proposed might be used for production of a RS-rich powder from banana starch with high RS level and functional properties. (c) 2006 Elsevier Ltd. All rights reserved. C1 IPN, Ctr Desarrollo Prod Biot, Yautepec 62731, Morelos, Mexico. IPN, Escuela Nacl Ciencias Biol, Dept Grad Inv Alimentos, Mexico City 11340, DF, Mexico. RP Bello-Perez, LA, IPN, Ctr Desarrollo Prod Biot, Km 8-5 Carr Yautepec-Jojutla,Colonia San Isidro,A, Yautepec 62731, Morelos, Mexico. EM labellop@ipn.mx CR APARICIOSAGUILAN A, 2005, STARCH-STARKE, V57, P405 ASP NG, 1992, EUR J CLIN NUTR S2, V46, S1 ASP NG, 1996, NUTR RES REV, V9, P1 BANKS W, 1971, STARKE, V23, P222 BELLOPEREZ LA, 2000, STARCH-STARKE, V52, P68 BERRY CS, 1986, J CEREAL SCI, V4, P301 CASSIDY A, 1994, BRIT J CANCER, V69, P937 CHIU CW, 1994, 5281276, US DEDECKERE EAM, 1995, BRIT J NUTR, V73, P287 EERLINGEN RC, 1995, J CEREAL SCI, V22, P129 ENGLYST HN, 1992, EUR J CLIN NUTR S2, V46, P33 ESCARPA A, 1996, J AGR FOOD CHEM, V44, P924 FAISANT N, 1995, BRIT J NUTR, V73, P111 FAISANT N, 1995, EUR J CLIN NUTR, V49, P98 GIDLEY MJ, 1987, CARBOHYD RES, V161, P301 GONI I, 1996, FOOD CHEM, V56, P445 HOLM J, 1985, J CEREAL SCI, V3, P193 HOLM J, 1986, STARCH-STARKE, V38, P224 HOOVER R, 2001, CARBOHYD POLYM, V45, P253 IYENGAR R, 1991, 5051271, US JENKINS DJA, 1987, AM J CLIN NUTR, V46, P968 LAURENTIN A, 2003, J AGR FOOD CHEM, V51, P5510 LEHMANN U, 2002, J AGR FOOD CHEM, V50, P5236 LIU Q, 2003, AACC ANN M, P139 MORELL MK, 2004, J AOAC INT, V87, P740 ROSIN PM, 2002, J FOOD COMPOS ANAL, V15, P367 SCHMIEDL D, 2000, CARBOHYD POLYM, V43, P183 SCHOCH TJ, 1964, METHODS CARBOHYDRATE, V4, P106 SHARP R, 2000, APPL ENVIRON MICROB, V66, P4212 SIEVERT D, 1989, CEREAL CHEM, V66, P342 SKRABANJA V, 1999, J AGR FOOD CHEM, V47, P2033 SLADE L, 1991, CRIT REV FOOD SCI, V30, P115 SPENCE KE, 1999, CARBOHYD POLYM, V40, P261 TOPPING DL, 2001, PHYSIOL REV, V81, P1031 TOVAR J, 1999, RRD AGR FOOD CHEM 1, V3, P1 NR 35 TC 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0963-9969 J9 FOOD RES INT JI Food Res. Int. PY 2007 VL 40 IS 2 BP 304 EP 310 PG 7 SC Food Science & Technology GA 134IM UT ISI:000244076700013 ER PT J AU Pascual, I Lopez, A Gomez, H Chappe, M Saroyan, A Gonzalez, Y Cisneros, M Charli, JL Chavez, MDA AF Pascual, Isel Lopez, Ali Gomez, Hansel Chappe, Mae Saroyan, Angelika Gonzalez, Yamile Cisneros, Miguel Charli, Jean Louis de los Angeles Chavez, Maria TI Screening of inhibitors of porcine dipeptidyl peptidase IV activity in aqueous extracts from marine organisms SO ENZYME AND MICROBIAL TECHNOLOGY LA English DT Article DE dipeptidyl peptidase IV; screening; marine organisms; inhibitors ID STRUCTURAL CONFIRMATION; PROTEINASE-INHIBITORS; PROTEASE INHIBITORS; SPONGE; CYCLOTHEONAMIDES; AMINOPEPTIDASE; PURIFICATION; THEONELLA; THROMBIN AB Dipeptidyl peptidase IV (DPPIV, EC 3.4.14.5) hydrolyses biologically active peptides that control critical functions. For example, action of glucagons-like peptide 1, an hormone that plays multiple roles in metabolic homeostasis and a potential agent for the treatment of type 2 diabetes mellitus is diminished by its susceptibility to DPPIV activity. The goal of this work was to the search for DPPIV inhibitory activity in the Caribbean marine fauna. The screening was done in aqueous crude extracts of species belonging to phyla Cnidaria, Mollusca, Annelida, Echinodermata, Poriphera, Chordata, Chlorophycota and Chlorophyta collected on the Northern coast of Havana (Cuba). An inhibitory activity was found in extracts of three species belonging to phyla Poriphera and Cnidaria: the sponge Xetospongia muta and the sea anemones Bunodosoma granulifera and Bartholomea annulata. The crude extracts from these species were treated with 2.5% final concentration of trichloroacetic acid (TCA) or with heat (60 degrees C, 10 min). Both treatments increased inhibitory activity in X. muta but failed in B. granulifera and B. annulata extracts. Preliminary characterization indicated that in each case the effect on DPPIV activity is dose-dependent, the inhibition is slow and the molecule responsible for DPPIV inhibition has a low molecular weight. The present contribution shows that the detected species are promising sources of DPPIV natural inhibitors with potential therapeutic applications (c) 2006 Elsevier Inc. All rights reserved. C1 Univ La Habana, Fac Biol, Havana 10400, Cuba. Univ Nacl Autonoma Mexico, Inst Biotecnol, Dept Genet & Desarrollo & Fisiol Mol, Cuernavaca 62210, Morelos, Mexico. RP Pascual, I, Univ La Habana, Fac Biol, 25 455 J & L Vedado,Plaza Revoluc, Havana 10400, Cuba. EM isel@fbio.uh.cu CR ABBENANTE G, 2005, MED CHEM, V1, P71 ALVAREZ C, 2003, COMM TOXICOL, V9, P117 BIETH JG, 1995, METHOD ENZYMOL, V248, P59 DELFIN J, 1996, TOXICON, V34, P1367 FRITZ H, 1972, HOPPESEYLERS Z PHYSL, V553, P19 GAUTIER JF, 2005, DIABETES METAB 1, V31, P233 GORRELL MD, 2005, CLIN SCI, V108, P1 HANESSIAN S, 2002, J AM CHEM SOC, V124, P13342 HANESSIAN S, 2004, J AM CHEM SOC, V126, P6064 KOLKENBROCK H, 1987, BIOL CHEM H-S, V368, P93 LEUNG D, 2000, J MED CHEM, V43, P305 MEBS D, 1983, TOXICON, V21, P257 MURAKAMI Y, 2002, J NAT PROD, V65, P259 NAGATSU T, 1976, ANAL BIOCHEM, V74, P466 NAKAO Y, 1995, BIOORGAN MED CHEM, V3, P1115 NAKAO Y, 1998, J NAT PROD, V61, P667 PASCUAL I, 2004, INT J BIOCHEM CELL B, V36, P138 SCHWEITZ H, 1995, J BIOL CHEM, V270, P25121 SCOPES R, 1982, PROTEIN PURIFICATION, V1987, P329 VANHOOF G, 1992, EUR J CLIN CHEM CLIN, V30, P333 WUNDERER G, 1976, METHOD ENZYMOL, V45, P881 NR 21 TC 0 PU ELSEVIER SCIENCE INC PI NEW YORK PA 360 PARK AVE SOUTH, NEW YORK, NY 10010-1710 USA SN 0141-0229 J9 ENZYME MICROB TECHNOL JI Enzyme Microb. Technol. PD FEB 5 PY 2007 VL 40 IS 3 SI Sp. Iss. SI BP 414 EP 419 PG 6 SC Biotechnology & Applied Microbiology GA 134GW UT ISI:000244072500007 ER PT J AU Metta-Magana, AJ Reyes-Martinez, R Tlahuext, H AF Metta-Magana, Alejandro J. Reyes-Martinez, Reyna Tlahuext, Hugo TI Crystal structure and NMR spectroscopy of aldonamides derived from D-glycero-D-gulo-heptono-1,4-lactone SO CARBOHYDRATE RESEARCH LA English DT Article DE aldonamides; conformation; N-15 NMR; crystal packing; hydrogen bonding ID D-GLUCONAMIDE; AMIDE LINKAGES; AMPHIPHILES; PACKING; DIFFRACTION AB We report the preparation of 12 aldonamides derived from D-glycero-D-gulo-heptono-1,4-lactone, their NMR characterization and study (C-13, H-1, N-15 NMR) in Me2SO-d(6) solution. The evaluation of the coupling constants (3)J(H,H) has shown that the sugar chain conformation in solution is all-trans for the studied amides. Because some amides crystallized, we discussed the crystal packing and found motifs. The conformation of the amides in the crystal structures displays two sickles at C2 and C3, with the exception of one that is all-trans. The bends cause the formation of the mean planes C1-C2-C3 and C3-C4-C5-C6-C7 with an average interplanar angle of 88 degrees. We found three main kinds of crystal packing depending on the N-substituent; head-to-tail, bilayer and pseudo-hexagonal mode, all the three show hydrogen-bonding networks that stabilize the crystal lattice, (c) 2006 Elsevier Ltd. All rights reserved. C1 Univ Autonoma Estado Morelos, Ctr Invest Quim, Cuernavaca 62209, Morelos, Mexico. RP Metta-Magana, AJ, Univ Autonoma Estado Morelos, Ctr Invest Quim, Av Univ 1001, Cuernavaca 62209, Morelos, Mexico. EM memaljo@yahoo.com CR *BRUK AXS, SMART VERS 5 618 SAI ANDRE C, 1992, CARBOHYD RES, V230, P31 ANDRE C, 1993, CARBOHYD RES, V240, P47 ANDRE C, 1994, CARBOHYD RES, V261, P1 ANDRE C, 1995, CARBOHYD RES, V266, P15 ANDRE C, 1995, CARBOHYD RES, V272, P129 ANGYAL SJ, 1989, J ORG CHEM, V54, P1927 AU V, 1993, 0550106, EP BHATTACHARYA S, 1999, CHEM MATER, V11, P3504 BRUNO IJ, 2002, ACTA CRYSTALLOGR B 3, V58, P389 DARBON N, 1984, ACTA CRYSTALLOGR C, V40, P1105 DARBONMEYSSONNI.N, 1985, ACTA CRYSTALLOGR C, V41, P1324 DESIRAJU GR, 2002, ACCOUNTS CHEM RES, V35, P565 DUBOIS GE, 1992, 9206601, WO ESTROFF LA, 2004, CHEM REV, V104, P1201 HAFKAMP RJH, 1999, J ORG CHEM, V64, P412 HARRIS RK, 2001, PURE APPL CHEM, V73, P1795 HORTON D, 1998, CARBOHYD RES, V308, P85 JEFFREY GA, 1990, CARBOHYD RES, V207, P211 JEFFREY GA, 1997, INTRO HYDROGEN BONDI KYELY DE, 1994, J AM CHEM SOC, V116, P571 METTAMAGANA AJ, 2004, ACTA CRYSTALLOGR E 6, V60, O1046 MULLERFAHRNOW A, 1988, CARBOHYD RES, V176, P165 MULLERFAHRNOW A, 1993, CARBOHYD RES, V242, P11 ODDON Y, 1986, ACTA CRYSTALLOGR C, V42, P1764 RIECKERT H, 1997, 5952274, US SHELDRICK GM, 1990, ACTA CRYSTALLOGR A, V46, P467 SHELDRICK GM, 1997, SHELXL97 SINDT AC, 1977, ACTA CRYSTALLOGR B, V33, P2659 TINANT B, 1986, ACTA CRYSTALLOGR C, V42, P579 WITANOWSKI M, 1981, ANN REPORTS NMR SP B, V11, P1 WITANOWSKI M, 1988, ANNU REP NMR SPECTRO, V18, P1 ZABEL V, 1986, CHEM PHYS LIPIDS, V39, P313 NR 33 TC 0 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0008-6215 J9 CARBOHYD RES JI Carbohydr. Res. PD FEB 5 PY 2007 VL 342 IS 2 BP 243 EP 253 PG 11 SC Biochemistry & Molecular Biology; Chemistry, Applied; Chemistry, Organic GA 133IC UT ISI:000244005600010 ER PT J AU Wang, Q Han, JL Xiao, ZG Xu, HS Sun, ZY Hu, ZG Zhang, XY Wang, HW Mao, RS Yuan, XH Xu, ZG Zhao, TC Zhang, HB Xu, HG Qi, HR Wang, Y Jia, F Wu, LJ Ding, XL Gao, Q Gao, H Li, SL Bai, Z Xiao, GQ Jin, GM Ren, ZZ Zhou, SG Sergey, YK AF Wang Qi Han Jian-Long Xiao Zhi-Gang Xu Hu-Shan Sun Zhi-Yu Hu Zheng-Guo Zhang Xue-Yin Wang Hong-Wei Mao Rui-Shi Yuan Xiao-Hua Xu Zhi-Guo Zhao Tie-Cheng Zhang Hong-Bin Xu Hua-Gen Qi Hui-Rong Wang Yue Jia Fei Wu Li-Jie Ding Xian-Li Gao Qi Gao Hui Li Song-Lin Bai Zhen Xiao Guo-Qing Jin Gen-Ming Ren Zhong-Zhou Zhou Shan-Gui Sergey Yu-Kun TI Elastic scattering angular dispersion of weakly bound nucleus F-17 SO HIGH ENERGY PHYSICS AND NUCLEAR PHYSICS-CHINESE EDITION LA Chinese DT Article DE elastic scattering; differential cross-section; angulax dispersion; halo nuclei ID INTERACTION CROSS-SECTIONS; PROTON HALO; REACTION-MECHANISMS; RICH NUCLEI; COLLISIONS; SHELL; COHERENCE; STATE; RIBLL AB The differential cross-sections for elastic scattering of F-17 and O-17 on Pb-208 have been measured at Radioactive Ion Beam Line at Lanzhou (RIBLL). The variation of the logarithms of differential cross-sections with the square of scattering angles, viz. angulax dispersion plot, shows clearly that there exists a turning point in the range of small scattering angles (6 degrees-20 degrees) for F-17 due to its exotic structure, while no turning point was observed for O-17. The experimental results have been compared with previous data of other groups. Systematical analysis on the available data seems to conclude that there is an exotic behavior of elastic scattering angular dispersion of weakly bound nuclei with halo or skin structure as compared with that of the stable nuclei. Therefore the fact that the turning point of the elastic scattering angular dispersion plot appears at small angle for weakly bound nuclei can be used as a new probe to investigate the halo and skin phenomenon. C1 Chinese Acad Sci, Inst Modern Phys, Lanzhou 730000, Peoples R China. Natl Lab Heavy Ion Accelerator Lanzhou, Ctr Theoret Nucl Phys, Lanzhou 730000, Peoples R China. Nanjing Univ, Dept Phys, Nanjing 210008, Peoples R China. Chinese Acad Sci, Inst Theoret Phys, Beijing 100080, Peoples R China. Chinese Acad Sci, Grad Sch, Beijing 100049, Peoples R China. UNAM, Ctr Ciencias Fis, Cuernavaca, Morelos, Mexico. Australian Natl Univ, Ctr Nonlinear Phys, Canberra, ACT 0020, Australia. RP Wang, Q, Chinese Acad Sci, Inst Modern Phys, Lanzhou 730000, Peoples R China. EM wangqi@impcas.ac.cn CR ABULMAGD AY, 1979, PHYS LETT B, V83, P27 BAKER SD, 1967, PHYS REV, V161, P1200 BROWN BA, 1996, PHYS LETT B, V381, P391 CAI XZ, 2002, PHYS REV C, V65 DEROSA A, 1989, PHYS REV C, V40, P627 DEROSA A, 1990, PHYS REV C, V41, P2062 DEROSA A, 1991, PHYS REV C, V44, P747 DONG YC, 2005, HIGH ENERG PHYS NUC, V29, P147 GOBBI A, 1980, HEAVY ION COLLISIONS, V2, P127 HUIZENGA JR, 1977, COO349665 USERDA, P131 KAKUEE OR, 2003, NUCL PHYS A, V728, P339 LI ZH, 2005, PHYS REV C, V72 LIN CJ, 2002, PHYS REV C, V66 LIU ZH, 2004, CHINESE PHYS LETT, V21, P1711 MARION JB, 1968, NUCL REACTION ANAL MITTIG W, 1987, PHYS REV LETT, V59, P1889 MORLOCK R, 1997, PHYS REV LETT, V79, P3837 NAVIN A, 1998, PHYS REV LETT, V81, P5089 NORENBERG W, 1980, HEAVY ION COLLISIONS, V2, P1 OZAWA A, 2006, NUCL INSTRUM METH B, V247, P155 PERRY R, 1981, PHYS REV C, V24, P1471 REN ZZ, 1996, PHYS REV C, V53, R572 REN ZZ, 1998, PHYS REV C, V57, P2752 RUSEK K, 2003, PHYS REV C, V67, P41604 SAINTLAURENT MG, 1989, Z PHYS A ATOMS NUCL, V332, P457 STRUTINSKY VM, 1973, PHYS LETT B, V44, P245 SUN Z, 2003, NUCL INSTRUM METH A, V503, P496 TANIHATA I, 1985, PHYS REV LETT, V55, P2676 WANG Q, 2004, CHINESE PHYS LETT, V21, P1911 WARNER RE, 1995, PHYS REV C, V52, P1166 ZELLER AF, 1978, NUCL PHYS A, V309, P255 ZHANG HY, 2002, NUCL PHYS A, V707, P303 NR 32 TC 0 PU SCIENCE CHINA PRESS PI BEIJING PA 16 DONGHUANGCHENGGEN NORTH ST, BEIJING 100717, PEOPLES R CHINA SN 0254-3052 J9 HIGH ENERGY PHYS NUCL PHYS-CH JI High Energy Phys. Nucl. Phys.-Chin. Ed. PD DEC PY 2006 VL 30 SU Suppl. 2 BP 136 EP 140 PG 5 SC Physics, Nuclear; Physics, Particles & Fields GA 125DR UT ISI:000243422700037 ER PT J AU Mendez-Montealvo, G Sanchez-Rivera, MM Paredes-Lopez, O Bello-Perez, LA AF Mendez-Montealvo, G. Sanchez-Rivera, M. M. Paredes-Lopez, O. Bello-Perez, L. A. TI Thermal and rheological properties of nixtamalized maize starch SO INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES LA English DT Article DE starch; retrogradation; nixtamalization ID CORN FLOUR; GELATINIZATION; AMYLOPECTIN; TORTILLA; LIME; RETROGRADATION; HYDROCOLLOIDS; VARIETIES; COOKING; PASTES AB The effect of nixtamalization process on thermal and rheological characteristics of corn starch was studied. Starch of raw sample had higher gelatinization temperature than its raw counterpart, because, the Ca2+ ions stabilize starch structure of nixtamalized sample; however, the enthalpy values were not different in both samples. The temperature of the phase transition of the retrograded starches (raw and nixtamalized) were not different at the storage times assessed, but the enthalpy values of the above mentioned transition was different, indicating a lower reorganization of the starch structure in the nixtamalized sample. The viscoamylographic profile showed differences between both starches, since raw starch had higher peak viscosity than the nixtamalized sample due to partial gelatinization of some granules during this heat treatment. Rheological test showed that at low temperature (25 degrees C) the raw and nixtamalized starches presented different behaviour; however, the elastic characteristic was more important in the starch gel structure. The nixtamalization process produced changes in thermal and rheological characteristics becoming important in those products elaborated from nixtamalized maize. (c) 2006 Elsevier B.V. All rights reserved. C1 IPN, Ctr Desarrollo Prod Biot, Yautepec 62731, Morelos, Mexico. IPN, Ctr Invest & Estudios Avanzados, Guanajuato 36500, Mexico. RP Bello-Perez, LA, IPN, Ctr Desarrollo Prod Biot, Apartado Postal 24, Yautepec 62731, Morelos, Mexico. EM labellop@ipn.mx CR *AM ASS CER CHEM, 2000, APPR METH AACC AGAMAACEVEDO E, 2004, INTERCIENCIA, V29, P643 ARAMBULA VG, 1999, J FOOD SCI, V64, P120 BILIADERIS CG, 1991, CAN J PHYSIOL PHARM, V69, P60 CAMPUSBAYPOLI ON, 1999, STARCH-STARKE, V51, P173 DOUBLIER JL, 1987, J CEREAL SCI, V5, P247 FERRY JD, 1980, VISCOELASTIC PROPERT FREITAS RA, 2000, CARBOHYD POLYM, V55, P3 FRENCH AD, 1984, STARCH CHEM TECHNOLO, P183 GIMENO E, 2004, CEREAL CHEM, V81, P100 GOMEZ MH, 1992, CEREAL CHEM, V69, P275 HERNANDEZLAUZARDO AN, 2004, STARCH-STARKE, V56, P357 JANE J, 1999, CEREAL CHEM, V76, P629 JI Y, 2003, CARBOHYD POLYM, V51, P439 KAUR L, 2002, FOOD CHEM, V79, P183 KAUR M, 2004, FOOD CHEM, V85, P131 KIM YS, 1997, STARCH-STARKE, V49, P97 MALI S, 2003, LEBENSM-WISS TECHNOL, V36, P475 MENDEZMONTEALVO G, 2005, AGROCIENCIA-MEXICO, V39, P267 MONDRAGON M, 2004, STARCH-STARKE, V56, P248 PAREDESLOPEZ O, 1994, FOOD CHEM, V50, P411 ROBLES RR, 1988, INT J FOOD SCI TECH, V23, P91 ROONEY LW, 1999, CEREAL FOOD WORLD, V44, P466 TECANTE A, 2001, ENCY LIFE SUPPORT SY, P292 THEBAUDIN JY, 1998, FOOD SCI TECHNOL-LEB, V31, P354 WANG LZ, 1994, CEREAL CHEM, V71, P451 YUAN RC, 1993, CEREAL CHEM, V70, P81 NR 27 TC 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0141-8130 J9 INT J BIOL MACROMOL JI Int. J. Biol. Macromol. PD DEC 15 PY 2006 VL 40 IS 1 BP 59 EP 63 PG 5 SC Biochemistry & Molecular Biology GA 119ZD UT ISI:000243052100009 ER PT J AU Rodriguez-Valdez, LM Villamisar, W Casales, M Gonzalez-Rodriguez, JG Martinez-Villafane, A Martinez, L Glossman-Mitnik, D AF Rodriguez-Valdez, Luz Maria Villamisar, W. Casales, M. Gonzalez-Rodriguez, J. G. Martinez-Villafane, Alberto Martinez, L. Glossman-Mitnik, Daniel TI Computational simulations of the molecular structure and corrosion properties of amidoethyl, aminoethyl and hydroxyethyl imidazolines inhibitors SO CORROSION SCIENCE LA English DT Article DE imidazolines; electrochemical techniques; DFT calculations; fukui indices; CO2 corrosion ID CARBON-DIOXIDE CORROSION; CHIH-DFT DETERMINATION; HYDROGEN-SULFIDE CORROSION; SET MODEL CHEMISTRY; ULTRAVIOLET-SPECTRA; MILD-STEEL; ABSOLUTE ELECTRONEGATIVITY; TOTAL ENERGIES; DERIVATIVES; PARAMETERS AB To proof the corrosion efficiency of hydroxyethyl, aminoethyl and amidoethyl imidazolines, they were evaluated by linear polarization resistance and polarization curves in deacrated 3% NaCl + Diesel + inhibitors saturated with CO2 at 50 degrees C. The most efficient inhibit or was the amido ethyl imidazoline, with an efficiency of 97.88% whereas the least efficient was the hydroxyethyl imidazoline, with an efficiency of 88.8%. A theoretical study of the corrosion inhibition efficiency of these imidazoline derivatives, was carried out using density functional theory (DFT). The computational calculations were used to obtain information about their molecular structure and those properties related with the inhibition efficiency of these inhibitors. The obtained correlations and theoretical conclusions agree well with the experimental results. (c) 2006 Elsevier Ltd. All rights reserved. C1 CIMAV, Chihuahua 31109, Mexico. UNAM, Ctr Ciencias Fis, Cuernavaca 62210, Morelos, Mexico. UAEM, CIICAp, Cuernavaca 62210, Morelos, Mexico. RP Glossman-Mitnik, D, CIMAV, Miguel de Cervantes 120,Complejo Ind Chihuahua, Chihuahua 31109, Mexico. EM daniel.glossman@cimav.edu.mx CR *ACC INC, 2004, MAT STUD DENS FUNCT ABDULAHAD PG, 1989, CORROSION, V45, P978 ADAMO C, 1999, J CHEM PHYS, V110, P6158 AWAD MK, 2004, J ELECTROANAL CHEM, V567, P219 BARONE V, 1998, J PHYS CHEM A, V102, P1995 BENTISS F, 2003, CORROS SCI, V45, P371 BENTISS F, 2004, CORROS SCI, V46, P2781 BEREKET G, 2003, J MOL STRUC-THEOCHEM, V663, P39 BLAJIEV O, 2004, ELECTROCHIM ACTA, V49, P2761 CRUZ J, 2003, J ELECTROCHEM SOC, V150, P26 DELLEY B, 1990, J CHEM PHYS, V92, P508 DELLEY B, 2000, J CHEM PHYS, V113, P7756 DEWAR MJS, 1977, J AM CHEM SOC, V99, P4899 FLORESHOLGUIN N, 2004, J MOL STRUC-THEOCHEM, V681, P77 FORESMAN JB, 1996, EXPLORING CHEM ELECT FRISCH MJ, 2004, GAUSSIAN 03 REVISION GEERLINGS P, 2003, CHEM REV, V103, P1793 GROWCOCK FB, 1989, CORROSION, V45, P1003 HIRSHFELD FL, 1977, THEOR CHIM ACTA, V44, P129 JOVANCICEVIC V, 1999, CORROSION, V55, P449 KERMANI MB, 2003, CORROSION, V59, P659 KHALIL N, 2003, ELECTROCHIM ACTA, V48, P2635 LEE C, 1988, J MOL STRUC-THEOCHEM, V163, P305 LI SL, 1999, CORROS SCI, V41, P1769 LOPEZ DA, 2005, CORROS SCI, V47, P735 LUKOVITS I, 1997, CORROSION, V53, P915 LUKOVITS I, 2001, CORROSION, V57, P3 MARTINEZ S, 2002, MATER CHEM PHYS, V77, P97 MARTINEZ S, 2003, J MOL STRUC-THEOCHEM, V640, P167 MENDEZ F, 1992, J MOL STRUCT, V277, P1981 MENDOZAWILSON AM, 2004, J MOL STRUC-THEOCHEM, V681, P71 MULLIKEN RS, 1955, J CHEM PHYS, V23, P1833 OGRETIR C, 1999, J MOL STRUC-THEOCHEM, V488, P223 PARR RG, 1978, J CHEM PHYS, V68, P3801 PARR RG, 1983, J AM CHEM SOC, V105, P7512 PARR RG, 1989, DENSITY FUNCTIONAL T PEARSON RG, 1988, INORG CHEM, V27, P734 PERDEW JP, 1996, PHYS REV LETT, V77, P3865 PERDEW JP, 1997, PHYS REV LETT, V78, P1396 PETERSSON GA, 1988, J CHEM PHYS, V89, P2193 PETERSSON GA, 1991, J CHEM PHYS, V94, P6081 QURAISHI A, 2002, MATER CHEM PHYS, V78, P18 RAMACHANDRAN S, 1999, CORROSION, V55, P259 RODRIGUEZVALDEZ LM, 2004, J MOL STRUC-THEOCHEM, V681, P83 RODRIGUEZVALDEZ LM, 2005, J MOL STRUC-THEOCHEM, V713, P65 SASTRI VS, 1997, CORROSION, V53, P617 SAYOS R, 1986, CORROS SCI, V26, P927 SZYPROWSKI AJ, 2000, BRIT CORROS J, V35, P155 SZYPROWSKI AJ, 2002, BRIT CORROS J, V37, P141 TAN YJ, 1996, CORROS SCI, V38, P1681 XUEYUAN Z, 2001, CORROS SCI, V43, P1417 YANG W, 1986, J AM CHEM SOC, V108, P5708 NR 52 TC 3 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0010-938X J9 CORROS SCI JI Corrosion Sci. PD DEC PY 2006 VL 48 IS 12 BP 4053 EP 4064 PG 12 SC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering GA 115XE UT ISI:000242766300012 ER PT J AU Aguilar, A Albarran, JL Lopez, HF Martinez, L AF Aguilar, A. Albarran, J. L. Lopez, H. F. Martinez, L. TI Microstructural response on the cracking resistance of alloy 600 SO MATERIALS LETTERS LA English DT Article DE nickel alloys; microstructure; heat treatment; grain boundaries; mechanical properties; deformation; fracture ID STRESS-CORROSION CRACKING; INTERGRANULAR CORROSION; HYDROGEN AB Precipitation of chromium rich carbides promotes the development of a Cr-depleted zone which in turn provided a weak path for the intergranular crack propagation. The role of low temperature anneals on the intergranular cracking resistance (IGC) of alloy 600 was investigated using modified wedge opening loading specimens heat treated at 930, 800 and 600 degrees C and exposed to high purity water pressurized with hydrogen at 300 degrees C. Mill annealing at 930 degrees C did lead to IGC susceptible microstructures. In this condition the alloy 600 exhibited the least crack growth rates (da/dt) of the order of 1.86 x 10(-12) m/s and characterized the substantial work hardening ahead of the crack front. In contrast, annealing at 600 degrees C (HT600) resulted in increasing IGC susceptibilities. Under these conditions, crack growth rates, da/dt, as high as 7.10 x 10(-10) m/s were found (HT600). Accordingly, significant interactions between the slip bands and the crack path lead to crack bifurcation into the slip planes and cavity formation. (c) 2006 Elsevier B.V. All rights reserved. C1 UNAM, Ctr Ciencias Fis, Cuernavaca 62251, Morelos, Mexico. Univ Wisconsin, Dept Mat, Milwaukee, WI 53201 USA. UNAM, Fac Quim, Cuernavaca 62251, Morelos, Mexico. RP Albarran, JL, UNAM, Ctr Ciencias Fis, POB 48-3, Cuernavaca 62251, Morelos, Mexico. EM jlag@fis.unam.mx CR BROWN CM, CORROSION ENG SECTIO, V55, P173 BRUEMMER SM, 1988, CORROS SCI NOV, P782 DEANS WF, 1979, J TEST EVAL, V7, P147 DELAFOSSE D, 2001, ENG FRACT MECH, V68, P693 NOVAK SR, 1969, J MATER, V4, P701 PAYNE SM, 1988, CORROSION, V44 SAHLAOUI H, 2004, MAT SCI ENG A-STRUCT, V372, P98 SUI G, 1997, CORROS SCI, V39, P565 TOTSUKA N, 2002, CORROSION, P1 UHLEMANN M, 1998, CORROS SCI, V40, P645 WAS GS, 1998, CORROSION, V54, P675 YOUNES CM, 1997, BRIT CORROS J, V32, P185 NR 12 TC 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0167-577X J9 MATER LETT JI Mater. Lett. PD JAN PY 2007 VL 61 IS 1 BP 274 EP 277 PG 4 SC Materials Science, Multidisciplinary; Physics, Applied GA 112FO UT ISI:000242511300068 ER PT J AU Romo-Uribe, A AF Romo-Uribe, A. TI Shear-induced long-range spatial correlation and banded texture in thermotropic copolyester. In situ light and X-ray scattering SO EUROPHYSICS LETTERS LA English DT Article ID LIQUID-CRYSTALLINE POLYMERS; MOLECULAR-ORIENTATION; MESOPHASE MACROMOLECULES; RHEOLOGICAL BEHAVIOR; PHASE-TRANSITIONS; FLOW; TRANSIENT; ACID; FIELD AB In situ small-angle light scattering (SALS) has enabled to elucidate shear-induced orientation correlations and monitor their relaxation in the thermotropic copolyester of 60 mol% hydroxybenzoic acid (B) and 40mol% ethylene terephthalate (ET). At 280 degrees C BET displays a nematic polydomain texture, the SALS and WAXS patterns are amorphous and isotropic. Applying steady shear, optical defect multiplication occurred and the microdomain sizes were reduced. However, the SALS pattern now showed anisotropy, the SALS pattern transitioned from a unimodal to a bimodal orientation. After cessation of shear, the orientation correlation rapidly relaxed to a polydomain and the SALS pattern became again isotropic. Above a threshold shear rate of about gamma(c) similar to 2 s(-1) shear now induced line defects oriented nearly orthogonal to the velocity axis. The texture relaxation above gamma(c) was also distinctly different, the well-known "banded texture" was formed upon cessation of shear. In situ X-ray scattering showed that the molecular chains always aligned along the flow direction regardless of the shear rate. However, the degree of macromolecular alignment improved significantly above gamma(c) and this is a condition to obtain the banded texture. C1 UNAM, Inst Ciencias Fis, Lab Nanopolimeros & Coloides, Cuernavaca 62210, Morelos, Mexico. RP Romo-Uribe, A, UNAM, Inst Ciencias Fis, Lab Nanopolimeros & Coloides, Av Univ S-N, Cuernavaca 62210, Morelos, Mexico. EM ARomo-Uribe@fis.unam.mx CR ALDERMAN, 1985, FARADAY DISCUSS CHEM, V79, P55 ANDRESEN EM, 1998, EUROPHYS LETT, V43, P296 BAEK SG, 1994, J RHEOL, V38, P1473 BEEKMANS F, 1996, J RHEOL, V40, P947 BLACKWELL J, 1983, MACROMOLECULES, V16, P1418 BURGHARDT WR, 1990, J RHEOL, V34, P959 DENEVE T, 1993, J RHEOL, V37, P515 ELIAS F, 2000, MACROMOLECULES, V33, P2060 GERVAT L, 1995, PHILOS T ROY SOC A, V350, P1 GLEESON JT, 1992, LIQ CRYST, V11, P341 GRAZIANO DJ, 1983, THESIS U CAMBRIDGE GRAZIANO DJ, 1984, MOL CRYST LIQ CRYST, V106, P73 HASHIMOTO T, 1989, MACROMOLECULES, V22, P422 HONGLADAROM K, 1994, J RHEOL, V38, P1505 HONGLADAROM K, 1996, MACROMOLECULES, V29, P5346 JACKSON WJ, 1976, J POLYM SCI POL CHEM, V14, P2043 KALIKA DS, 1990, J RHEOL, V34, P139 KISS G, 1980, MOL CRYST LIQUID CRY, V60, P267 LARSON RG, 1991, J RHEOL, V35, P539 LARSON RG, 1993, LIQ CRYST, V15, P151 MARRUCCI G, 1989, MACROMOLECULES, V22, P4076 MEESIRI W, 1982, J POLYM SCI PP, V20, P719 MENCZEL J, 1980, J POLYM SCI POL PHYS, V18, P1433 NICELY VA, 1987, MACROMOLECULES, V20, P573 PICKEN SJ, 1991, MACROMOLECULES, V24, P1366 POPLE JA, 1996, POLYMER, V37, P4187 RITI JB, 1997, J RHEOL, V41, P1247 ROMOURIBE A, 1997, MAT RES S C, V461, P63 ROMOURIBE A, 1999, P ROY SOC LOND A MAT, V455, P1175 ROMOURIBE A, 2001, P ROY SOC LOND A MAT, V457, P207 SHIMODA T, 1997, MACROMOLECULES, V30, P5045 VERMANT J, 1994, J NON-NEWTON FLUID, V53, P1 VERMANT J, 1994, J RHEOL, V38, P1571 VINEY C, 1983, J MATER SCI, V18, P1136 WINDLE AH, 1985, FARADAY DISCUSS, V79, P55 WISSBRUN KF, 1980, BRIT POLYM J, V12, P163 NR 36 TC 1 PU EDP SCIENCES S A PI LES ULIS CEDEX A PA 17, AVE DU HOGGAR, PA COURTABOEUF, BP 112, F-91944 LES ULIS CEDEX A, FRANCE SN 0295-5075 J9 EUROPHYS LETT JI Europhys. Lett. PD NOV PY 2006 VL 76 IS 4 BP 609 EP 615 PG 7 SC Physics, Multidisciplinary GA 108AA UT ISI:000242210900011 ER PT J AU Gonzalez-Rodriguez, JG Haro, S Martinez-Villafane, A Salinas-Bravo, VM Porcayo-Calderon, J AF Gonzalez-Rodriguez, J. G. Haro, S. Martinez-Villafane, A. Salinas-Bravo, V. M. Porcayo-Calderon, J. TI Corrosion performance of heat resistant alloys in Na2SO4-V2O5 molten salts SO MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING LA English DT Article DE hot corrosion; heat resistant alloys; acidic fluxing ID HOT CORROSION; INITIATION AB The corrosion resistant of three heat resistant alloys in molten vanadium pentoxide (V2O5), sodium sulfate (Na2SO4) and 80(mol%) V2O5-20Na(2)SO(4) has been evaluated using the weight loss technique. Materials included Fe-25Cr-35Ni-0.45C, Fe-35Cr-45Ni with 0.12 and 0.45C alloys. Temperatures included 600, 700 and 800 degrees C for V2O5 and the 80V(2)O(5)-20Na(2)SO(4) mixture, and 800, 900 and 1000 degrees C for Na2SO4. The tests were supplemented by detailed electronic microscopy and microanalysis studies. In all cases, the least resistant alloy was the Fe-25Cr-35Ni-0.45C one whereas the most resistant was the Fe-35Cr-45Ni-0.12C one. The results are discussed in terms of the acidic dissolution of the external protective Cr2O3, Al2O3 and SiO2 layers, by the salts and internal sulfidation. (c) 2006 Published by Elsevier B.V. C1 Univ Autonoma Estado Morelos, FCQI, CIICAP, Cuernavaca 62210, Morelos, Mexico. Univ Autonoma Zacatecas, Zacatecas, Mexico. CIMAV, Chihuahua, Mexico. Inst Invest Elect, Cuernavaca, Morelos, Mexico. RP Gonzalez-Rodriguez, JG, Univ Autonoma Estado Morelos, FCQI, CIICAP, Av Univ 1001,Col Chamilpa, Cuernavaca 62210, Morelos, Mexico. EM ggonzalez@uaem.mx CR BACKENSTO EB, 1957, 22 MIDY M APIS DIV R BACKENSTO EB, 1958, NACE PUBLICATION, V5910 CUNNINGHAM GW, 1956, CORROSION, V12, T389 DEMEL O, 2538 SGAW FRYBURG GC, 1982, J ELECTROCHEM SOC, V129, P571 FRYBURG GC, 1984, J ELECTROCHEM SOC, V131, P2985 GRABKE HJ, 1976, WERKST KORROS, V27, P291 GREENERT WJ, 1962, CORROSION, V18, P575 HARPER MA, 2000, OXID MET, V53, P5 HWANG YS, 1987, CORROSION, V43, P353 HWANG YS, 1989, CORROSION, V45, P933 KAI W, 2001, OXID MET, V56, P1 SINGH IB, 2003, CORROS SCI, V51, P765 SORREL G, 1956, NACE PUBLICATION, V567 STEEL C, 1981, CAST MET J, P28 WONGMORENO A, 1994, CORROSION 94, P185 YOUNG DJ, 1980, REV HIGH TEMP MATER, V4, P299 NR 17 TC 1 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0921-5093 J9 MATER SCI ENG A-STRUCT MATER JI Mater. Sci. Eng. A-Struct. Mater. Prop. Microstruct. Process. PD NOV 5 PY 2006 VL 435 BP 258 EP 265 PG 8 SC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary GA 100QI UT ISI:000241683200034 ER PT J AU Cuevas-Arteaga, C Porcayo-Calderon, J AF Cuevas-Arteaga, C. Porcayo-Calderon, J. TI Electrochemical noise analysis in the frequency domain and determination of corrosion rates for SS-304 stainless steel SO MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING LA English DT Article DE current time series; electrochemical noise; resistance noise; pitting ID IMPEDANCE AB Studies of the corrosion evaluation of SS-304 stainless steel exposed in lithium bromide aqueous solution have been carried out applying the electrochemical noise technique and polarization curves, as well as the weight loss method. The test temperatures were ambient to 80 degrees C, and the exposure time was during 15 days. The main objective was to determine the corrosion rates and the type of corrosion that SS-304 suffers under the mentioned conditions, with the purpose of evaluating its application to heat pumps/transformers. Polarization curves revealed the formation of a passive film, which under increased temperature changed its protective properties. The electrochemical noise results suggested that at the test temperatures the type of corrosion was mixed or pitting corrosion. The noise resistance was calculated through statistical analysis, and then, the Stern-Geary equation and Faraday law were applied to determine mass loss, which was compared to that obtained from weight loss method. Two localized corrosion indicators were also obtained: pitting index (PI) and the coefficient of variation of current (CV), which were compared each other and interrelated with the noise signals and visual observations. To support the type of corrosion process, scanning electron microscopy (SEM) coupled with energy dispersive X-ray analyzer (EDX) was used to study the surface morphology of the corroded specimens and for determining qualitative analyses. (c) 2006 Elsevier B.V. All rights reserved. C1 UAEM, Ctr Investigac Ingn & Ciencias Aplicadas, Cuernavaca 62209, Morelos, Mexico. Inst Investigac Elect, Cuernavaca 62440, Morelos, Mexico. RP Cuevas-Arteaga, C, UAEM, Ctr Investigac Ingn & Ciencias Aplicadas, Av Univ 1001,Col Chamilpa, Cuernavaca 62209, Morelos, Mexico. EM ccuevas@uaem.mx CR *ASTM, 1994, G1 ASTM *ASTM, 1994, G102 ASTM *ASTM, 1995, G31 ASTM ALAWADHI AA, 1999, P CORROSION 1999 CHENG YF, 1999, CORROS SCI, V41, P1245 COTTIS R, 1999, ELECTROCHEMICAL IMPE, P78 CUEVASARTEAGA C, 2004, CORROSION, V60, P548 CUEVASARTEAGA C, 2005, P EUR CORR C LISB PO CUEVASARTEAGA C, 2006, REV MEX ING QUIM, V5, P27 GOELLNER A, 2000, P CORROSION 2000 HOLLAND FA, 2000, APPL THERM ENG, V20, P863 IGUAL MA, 2004, CORROS SCI, V46, P2955 IMAI H, 2001, CORRROSION BEHAV CAR MANSFELD F, 1997, CORROS SCI, V39, P255 MANSFELD F, 1998, ELECTROCHIM ACTA, V43, P435 MANSFELD F, 2000, P CORROSION 2000 ROMERO RJ, 2006, IN PRESS APPL THERM SANCHEZAMAYA JM, 2005, CORROS SCI, V47, P3280 SCULLY JR, 1995, ASTM MANUAL SERIES, V20, CH7 ZHOU XY, 2002, CORROS SCI, V44, P841 NR 20 TC 0 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0921-5093 J9 MATER SCI ENG A-STRUCT MATER JI Mater. Sci. Eng. A-Struct. Mater. Prop. Microstruct. Process. PD NOV 5 PY 2006 VL 435 BP 439 EP 446 PG 8 SC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary GA 100QI UT ISI:000241683200058 ER PT J AU Salcedo, D AF Salcedo, Dara TI Equilibrium phase diagrams of aqueous mixtures of malonic acid and sulfate/ammonium salts SO JOURNAL OF PHYSICAL CHEMISTRY A LA English DT Article ID DICARBOXYLIC-ACIDS; AMMONIUM-SULFATE; HYGROSCOPIC PROPERTIES; ATMOSPHERIC AEROSOLS; ORGANIC-COMPOUNDS; 298.15 K; PARTICLES; CRYSTALLIZATION; DELIQUESCENCE; CLIMATE AB Tropospheric aerosols are usually complex mixtures of inorganic and organic components. Although the thermodynamic properties of inorganic aerosols have been widely studied, the effect of organics on such properties is still under discussion. In this study, solubility in water, water activity (a(w)) of aqueous solutions, deliquescence relative humidity (DRH), eutonic composition, and eutonic DRH were determined for bulk mixtures of malonic acid (MA) with ammonium sulfate (AS) and ammonium bisulfate (ABS) at 25 degrees C over the full range of composition (from 0 wt % to the solubility limit of the mixture components). The data were used to construct equilibrium phase diagrams, which show the phase of the mixtures as a function of total composition, dry mixture composition, water content, and ambient relative humidity (RH). This work complements previous reports on the thermodynamic properties of AS/MA mixtures because the range of concentrations investigated is larger than in any other published single study. On the other hand, this is the first report on the aw, deliquescence, and water absorption of ABS/MA mixtures. The eutonic composition for AS/MA mixtures was found to be 66.8 MA dry wt % (MA dry wt %) MA mass x 100/(AS mass + MA mass) with a DRH of 0.437. The eutonic composition for the ABS/MA mixtures was lower than for the AS/MA mixtures: 20.9 MA dry wt % with a DRH of 0.327. Measured aw of liquid AS/MA and ABS/MA solutions is compared with an extended Zdanovskii-Stokes-Robinson expression, obtaining a good agreement (error < 5-6%). The expression was used to predict water uptake of mixtures and might be useful to interpret particle hygroscopic growth experiments. Comparison of the AS/MA and ABS/MA systems indicates that ABS reduces the DRH and enhances water uptake, relative to mixtures with AS. The results confirm that ambient particles containing sulfate and water-soluble organic compounds can remain liquid or partially liquid at very low ambient RH conditions, especially if the sulfate is not completely neutralized. C1 Univ Auton Estado Morelos, Ctr Invest Quim, Cuernavaca 62209, Morelos, Mexico. RP Salcedo, D, Univ Auton Estado Morelos, Ctr Invest Quim, Cuernavaca 62209, Morelos, Mexico. EM dara@ciq.uaem.mx CR *IPCC, 2001, IPCC 3 ASS REP CLIM BRABAN CF, 2003, J PHYS CHEM A, V107, P6594 BRABAN CF, 2004, ATMOS CHEM PHYS, V4, P1451 BROOKS SD, 2002, GEOPHYS RES LETT, V29 CHOI MY, 2002, ENVIRON SCI TECHNOL, V36, P2422 CLEGG SL, 1998, J PHYS CHEM A, V102, P2155 CLEGG SL, 2003, AEROSOL SCI, V34, P667 CLEGG SL, 2006, J PHYS CHEM A, V110, P5692 CRUZ CN, 2000, ENVIRON SCI TECHNOL, V34, P4313 CZICZO DJ, 1997, J GEOPHYS RES-ATMOS, V102, P18843 FREDENSLUND A, 1975, AICHE J, V21, P1086 HAMERI K, 2002, AICHE J, V48, P1309 HANSEN HK, 1991, IND ENG CHEM RES, V30, P2352 KANAKIDOU M, 2005, ATMOS CHEM PHYS, V5, P1053 MADER BT, 2004, J GEOPHYS RES-ATMOS, V109 MARCOLLI C, 2004, J PHYS CHEM A, V108, P2216 MCMURRY P, 2004, PARTICULATE MATTER S ONASCH TB, 1999, J GEOPHYS RES, V104, P21 PARSONS MT, 2004, J GEOPHYS RES, V109 PARSONS MT, 2004, J PHYS CHEM A, V108, P11600 PARSONS MT, 2006, J PHYS CHEM A, V110, P8108 PATHAK RK, 2004, ATMOS ENVIRON, V38, P2965 PENG C, 2001, ENVIRON SCI TECHNOL, V35, P4495 POSCHL U, 2005, ANGEW CHEM INT EDIT, V44, P7520 PRENNI AJ, 2003, ATMOS ENVIRON, V37, P4243 RAATIKAINEN T, 2005, ATMOS CHEM PHYS, V5, P2475 SALCEDO D, 2006, ATMOS CHEM PHYS, V6, P925 SATHEESH SK, 2005, ATMOS ENVIRON, V39, P2089 SEINFELD JH, 1998, ATMOSPHERIC CHEM PHY SEINFELD JH, 2004, AICHE J, V50, P1096 STOKES RH, 1966, J PHYS CHEM-US, V70, P2126 TANG IN, 1994, J GEOPHYS RES-OCEANS, V99, P18 WANG HB, 2006, J ATMOS CHEM, V53, P43 WEXLER AS, 2002, J GEOPHYS RES, V107, D14 WISE ME, 2003, J GEOPHYS RES-ATMOS, V108 YU LE, 2005, ENVIRON SCI TECHNOL, V39, P707 NR 36 TC 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 1089-5639 J9 J PHYS CHEM A JI J. Phys. Chem. A PD NOV 9 PY 2006 VL 110 IS 44 BP 12158 EP 12165 PG 8 SC Chemistry, Physical; Physics, Atomic, Molecular & Chemical GA 101GO UT ISI:000241729200013 ER PT J AU Han, JL Wang, Q Xiao, ZG Xu, HS Sun, ZY Hu, ZG Zhang, XY Wang, HW Mao, RS Yuan, XH Xu, ZG Zhao, TC Zhang, HB Xu, HG Qi, HR Wang, Y Jia, F Wu, LJ Ding, XL Gao, Q Gao, H Li, SL Bai, Z Xiao, GQ Jin, GM Ren, ZZ Zhou, SG Sergey, YK AF Han Jian-Long Wang Qi Xiao Zhi-Gang Xu Hu-Shan Sun Zhi-Yu Hu Zheng-Guo Zhang Xue-Yin Wang Hong-Wei Mao Rui-Shi Yuan Xiao-Hua Xu Zhi-Guo Zhao Tie-Cheng Zhang Hong-Bin Xu Hua-Gen Qi Hui-Rong Wang Yue Jia Fei Wu Li-Jie Ding Xian-Li Gao Qi Gao Hui Li Song-Lin Bai Zhen Xiao Guo-Qing Jin Gen-Ming Ren Zhong-Zhou Zhou Shan-Gui Sergey Yu-Kun TI Exotic behavior of elastic scattering differential cross-sections of weakly bound nucleus F-17 at small angles SO HIGH ENERGY PHYSICS AND NUCLEAR PHYSICS-CHINESE EDITION LA English DT Article DE elastic scattering; differential cross-section; halo nuclei ID RICH NUCLEI; PROTON HALO; SHELL; STATE AB The differential cross-sections for elastic scattering of F-17 and O-17 on Pb-208 have been measured at Radioactive Ion Beam Line at Lanzhou (RIBLL). The variation of the logarithms of differential cross-sections with the square of scattering angles shows clearly that there exists a turning point in the range of small scattering angles (6 degrees-20 degrees) for F-17 having exotic structure, while no turning point was observed in the O-17 elastic scattering. The experimental results have been compared with previous data. Systematical analysis on the available data seems to conclude that there is an exotic behavior of elastic scattering differential cross-sections of weakly bound nuclei with halo or skin structure as compared with that of the ordinary nuclei near stable line. Therefore the fact that the turning point of the logarithms of differential cross-sections appears at small angle for weakly bound nuclei could be used as a new probe to investigate the halo and skin phenomenon. C1 Chinese Acad Sci, Inst Modern Phys, Lanzhou 730000, Peoples R China. Grad Univ, Chinese Acad Sci, Beijing 100049, Peoples R China. Natl Lab Heavy Ion Accelerator Lanzhou, Ctr Theoret Nucl Phys, Lanzhou 730000, Peoples R China. Nanjing Univ, Dept Phys, Nanjing 210008, Peoples R China. Chinese Acad Sci, Inst Theoret Phys, Beijing 100080, Peoples R China. UNAM, Ctr Ciencias Fis, Cuernavaca, Morelos, Mexico. Australian Natl Univ, Ctr Nonlinear Phys, RSPhysSE, Canberra, ACT 0200, Australia. RP Han, JL, Chinese Acad Sci, Inst Modern Phys, Lanzhou 730000, Peoples R China. EM wangqi@impcas.ac.cn CR AUDI G, 2003, NUCL PHYS A, V729, P337 BAKER SD, 1967, PHYS REV, V161, P1200 BROWN BA, 1996, PHYS LETT B, V381, P391 CAI XZ, 2002, PHYS REV C, V65 KAKUEE OR, 2003, NUCL PHYS A, V728, P339 LIN CJ, 2002, PHYS REV C, V66 MITTIG W, 1987, PHYS REV LETT, V59, P1889 MORLOCK R, 1997, PHYS REV LETT, V79, P3837 NAVIN A, 1998, PHYS REV LETT, V81, P5089 REN ZZ, 1996, PHYS REV C, V53, P572 REN ZZ, 1998, PHYS REV C, V57, P2752 SAINTLAURENT MG, 1989, Z PHYS A ATOMS NUCL, V332, P457 SUN Z, 2003, NUCL INSTRUM METH A, V503, P496 TANIHATA I, 1985, PHYS REV LETT, V55, P2676 WARNER RE, 1995, PHYS REV C, V52, P1166 ZHANG HY, 2002, NUCL PHYS A, V707, P303 NR 16 TC 0 PU SCIENCE CHINA PRESS PI BEIJING PA 16 DONGHUANGCHENGGEN NORTH ST, BEIJING 100717, PEOPLES R CHINA SN 0254-3052 J9 HIGH ENERGY PHYS NUCL PHYS-CH JI High Energy Phys. Nucl. Phys.-Chin. Ed. PD NOV PY 2006 VL 30 IS 11 BP 1058 EP 1061 PG 4 SC Physics, Nuclear; Physics, Particles & Fields GA 102SN UT ISI:000241833700004 ER PT J AU Navarrete-Vazquez, G Moreno-Diaz, H Estrada-Soto, S Tlahuext, H AF Navarrete-Vazquez, Gabriel Moreno-Diaz, Hermenegilda Estrada-Soto, Samuel Tlahuext, Hugo TI 2-(2-methoxyphenyl)-1H-benzimidazole SO ACTA CRYSTALLOGRAPHICA SECTION E-STRUCTURE REPORTS ONLINE LA English DT Article ID HYDROGEN-BOND; DESIGN; DERIVATIVES; CRYSTALS AB The asymmetric unit of the title compound, C14H12N2O, contains two different conformational isomers of 2-( 2-methoxyphenyl)-1H-benzimidazole. The dihedral angles between the benzimidazole ring systems and the 2- methoxyphenyl substituents are 26.9 (3) and -13.3 (3)degrees. The conformers are linked by bifurcated three-centre hydrogen bonds, forming chains running along the a axis. The packing is further stabilized by offset and edge-to-face pi-pi interactions. C1 Univ Autonoma Estado Morelos, Ctr Invest Quim, Cuernavaca 62100, Morelos, Mexico. Univ Autonoma Estado Morelos, Fac Farm, Cuernavaca 62100, Morelos, Mexico. RP Tlahuext, H, Univ Autonoma Estado Morelos, Ctr Invest Quim, Av Univ 1001 Col, Cuernavaca 62100, Morelos, Mexico. EM tlahuext@ciq.uaem.mx CR *BRUK AXS INC, 2000, SMART VERS 5 618 SAI ADAMS H, 1996, ANGEW CHEM INT EDIT, V35, P1542 BALI A, 2005, BIOORG MED CHEM LETT, V15, P3962 BERNSTEIN J, 1995, ANGEW CHEM INT EDIT, V34, P1555 DESIRAJU GR, 1991, ACCOUNTS CHEM RES, V24, P290 DESIRAJU GR, 1999, WEAK HYDROGEN BOND, P5 ESTRADASOTO S, 2006, LIFE SCI, V79, P430 HANTON LR, 1992, J CHEM SOC CHEM 0815, P1134 HUNTER CA, 1994, CHEM SOC REV, P101 LEHN JM, 1990, ANGEW CHEM INT EDIT, V29, P1304 LEHN JM, 1995, SUPRAMOLECULAR CHEM MORENODIAZ H, 2006, ACTA CRYSTALLOGR E 7, V62, O2601 NAVARRETEVAZQUEZ G, 2006, BIOORG MED CHEM LETT, V16, P4169 SHELDRICK GM, 1997, SHELXS97 SHELXL97 SHELDRICK GM, 2003, SADABS VERS 2 10 SPEK AL, 2003, J APPL CRYSTALLOGR 1, V36, P7 WESTRIP SP, 2006, UNPUB NR 17 TC 1 PU BLACKWELL PUBLISHING PI OXFORD PA 9600 GARSINGTON RD, OXFORD OX4 2DQ, OXON, ENGLAND SN 1600-5368 J9 ACTA CRYSTALLOGR E-STRUCT REP JI Acta Crystallogr. Sect. E.-Struct Rep. Online PD NOV PY 2006 VL 62 PN Part 11 BP O4816 EP O4818 PG 3 SC Crystallography GA 100TK UT ISI:000241691500177 ER PT J AU Mochan, WL Villarreal, C AF Mochan, W. L. Villarreal, C. TI Casimir effect for arbitrary materials: contributions within and beyond the light cone SO NEW JOURNAL OF PHYSICS LA English DT Article ID MU-M; FORCE; MEDIA; MIRRORS; ROUGHNESS; PLATES; RANGE AB We obtain an expression for the Casimir force within a planar cavity without making particular models or assumptions about the nature of its walls. We obtain the energy and stress tensor in a closed ancillary system that has the same optical response as the target system, but that allows a fully quantum-mechanical treatment of the electromagnetic degrees of freedom. Our results constitute a generalization of the Lifshitz formula, applicable to a wide class of materials, which could be semi-infinite or finite, local or spatially dispersive, homogeneous or layered, dissipative or dissipationless. We discuss the incorporation of evanescent fields in the formalism, the electromagnetic normal modes of the system, its thermodynamic properties, and the generalization of our results to arbitrary geometries. C1 Univ Nacl Autonoma Mexico, Ctr Ciencias Fis, Cuernavaca 62251, Morelos, Mexico. Univ Nacl Autonoma Mexico, Inst Fis, Mexico City 01000, DF, Mexico. RP Mochan, WL, Univ Nacl Autonoma Mexico, Ctr Ciencias Fis, Apartado Postal 48-3, Cuernavaca 62251, Morelos, Mexico. 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Phys. PD OCT 20 PY 2006 VL 8 AR 242 DI ARTN 242 PG 21 SC Physics, Multidisciplinary GA 096YM UT ISI:000241412800009 ER PT J AU Luo, XF Wang, XY Liao, L Wang, XM Gamboa, S Sebastian, PJ AF Luo, Xufang Wang, Xianyou Liao, Li Wang, Ximin Gamboa, Sergio Sebastian, P. J. TI Effects of synthesis conditions on the structural and electrochemical properties of layered Li[Ni1/3Co1/3Mn1/3]O-2 cathode material via the hydroxide co-precipitation method LIB SCITECH SO JOURNAL OF POWER SOURCES LA English DT Article DE lithium ion battery; Li[Ni1/3Co1/3Mn1/3]O-2; hydroxide co-precipitation; structure characteristics; electrochemical properties ID LITHIUM-ION BATTERIES; INSERTION MATERIAL; LI(NI1/3CO1/3MN1/3)O-2; LICO1/3NI1/3MN1/3O2; LINI1/3MN1/3CO1/3O2; PERFORMANCE AB The uniform layered Li[Ni1/3Co1/3Mn1/3]O-2 cathode material for lithium ion batteries was prepared by using (Ni1/3Co1/3Mn1/3)(OH)(2) synthesized by a liquid phase co-precipitation method as precursor. The effects of calcination temperature and time on the structural and electrochemical properties of the Li[Ni1/3Co1/3Mn1/3]O-2 were systemically studied. XRD results revealed that the optimal prepared conditions of the layered Li[Ni1/3CO1/3Mn1/3]O-2 were 850 degrees C for 18 h. Electrochemical measurement showed that the sample prepared under the above conditions has the highest initial discharge capacity of 162.1 mAh g(-1) and the smallest irreversible capacity loss of 9.2% as well as stable cycling performance at a constant current density of 16 mA g(-1) between 3 and 4.3 V versus Li at room temperature. (c) 2006 Elsevier B.V. All rights reserved. C1 Xiangtan Univ, Coll Chem, Hunan 411105, Peoples R China. UNAM, CIE, Solar Hydrogen Fuel Cell Grp, Temixco 62580, Morelos, Mexico. RP Wang, XY, Xiangtan Univ, Coll Chem, Hunan 411105, Peoples R China. EM wxianyou@yahoo.com CR BELHAROUAK I, 2003, J POWER SOURCES, V123, P247 CHO TH, 2005, J POWER SOURCES, V142, P306 CHOI J, 2005, J ELECTROCHEM SOC, V152, A1714 DAHN JR, 1990, SOLID STATE IONICS, V44, P87 GAO Y, 2003, 6620400, US HENRIKSEN G, 2003, 204 M EL SOC ORL 12 JOUANNEAU S, 2003, J ELECTROCHEM SOC, V150, A1637 KANG SH, 2003, J POWER SOURCES, V119, P150 KIM JM, 2004, ELECTROCHIM ACTA, V49, P937 KIM MG, 2005, J ELECTROCHEM SOC, V152, A1320 LEE MH, 2004, ELECTROCHIM ACTA, V50, P939 LI DC, 2004, J POWER SOURCES, V132, P150 LIU ZL, 1999, J POWER SOURCES, V81, P416 LU ZH, 2001, ELECTROCHEM SOLID ST, V4, A200 LUO XF, 2005, IN PRESS J POWER SOU OHZUKU T, 2001, CHEM LETT 0705, P642 PATOUX S, 2004, ELECTROCHEM COMMUN, V6, P767 REIMERS JN, 1993, SOLID STATE IONICS, V61, P335 SHAJU KM, 2002, ELECTROCHIM ACTA, V48, P145 STOREY C, 2001, J POWER SOURCES, V97, P541 YABUUCHI N, 2003, J POWER SOURCES, V119, P171 NR 21 TC 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0378-7753 J9 J POWER SOURCES JI J. Power Sources PD OCT 20 PY 2006 VL 161 IS 1 BP 601 EP 605 PG 5 SC Electrochemistry; Energy & Fuels GA 096YE UT ISI:000241412000075 ER PT J AU Lagunas-Munoz, VH Cabrera-Valladares, N Bolivar, F Gosset, G Martinez, A AF Lagunas-Munoz, V. H. Cabrera-Valladares, N. Bolivar, F. Gosset, G. Martinez, A. TI Optimum melanin production using recombinant Escherichia coli SO JOURNAL OF APPLIED MICROBIOLOGY LA English DT Article DE aromatics; Escherichia coli; melanin; Rhizobium etli; tyrosinase; tyrosine ID ELECTRON-SPIN RESONANCE; TYROSINASE GENE; PURIFICATION; EXPRESSION; EUMELANIN; PROTEINS; RADICALS; PIGMENT; CLONING AB Aims: A parametric study was conducted to define optimum conditions to achieve high yields in the conversion of tyrosine to eumelanin (EuMel) using recombinant Escherichia coli. Methods and Results: Escherichia coli W3110 (pTrcMutmelA) expressing the tyrosinase coding gene from Rhizobium etli and glucose-mineral media were used to transform tyrosine into EuMel. Batch aerobic fermentor cultures were performed to study the effect of temperature, pH and inducer concentration (isopropyl-D-thio-galactopyranoside) on melanin production. Under optimum conditions, 0.1 mmol l(-1) of isopropyl-D-thio-galactopyranoside, temperature of 30 degrees C, and changing pH from 7.0 to 7.5 during the production phase, a 100% conversion of tyrosine into EuMel is obtained. Furthermore, tyrosine feeding allowed us to obtain the highest level (6 g l(-1)) of EuMel produced by recombinant E. coli reported until now. Conclusions: The most important factors affecting melanin formation and hence influencing the rate and efficiency in the conversion of tyrosine into EuMel in this system, are the temperature and pH. Significance and Impact of the Study: Maximum theoretical yield was obtained using a simple culture process and mineral media to convert tyrosine (a medium value compound) into melanin, a high value compound. The process reported here avoids the use of purified tyrosinase, expensive chemical methods or the cumbersome extraction of this polymer from animal or plant tissues. C1 Univ Nacl Autonoma Mexico, Inst Biotecnol, Dept Ingn Celular & Biocatalisis, Cuernavaca 62250, Morelos, Mexico. RP Martinez, A, Univ Nacl Autonoma Mexico, Inst Biotecnol, Dept Ingn Celular & Biocatalisis, Apdo Postal 510-3, Cuernavaca 62250, Morelos, Mexico. 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Appl. Microbiol. PD NOV PY 2006 VL 101 IS 5 BP 1002 EP 1008 PG 7 SC Biotechnology & Applied Microbiology; Microbiology GA 093VT UT ISI:000241199100004 ER PT J AU Vidal, A Best, R Rivero, R Cervantes, J AF Vidal, A. Best, R. Rivero, R. Cervantes, J. TI Analysis of a combined power and refrigeration cycle by the exergy method SO ENERGY LA English DT Article DE ammonia-water; Kalina cycle; waste heat; renewable energy; ASPEN Plus; Lorenz cycle ID THERMODYNAMIC CYCLE; 2ND LAW; ENERGY AB The exergy analysis method was applied in order to evaluate the new combined cycle proposed by Goswami [Solar thermal technology: present status and ideas for the future. Energy Sources 1998;20:137-45], using Hasan-Goswami-Vijayaraghavan parameters. This new combined cycle was proposed to produce both power and cooling simultaneously with only one heat source and using ammonia-water mixture as the working fluid. The simulation of the cycle was carried out in the process simulator ASPEN Plus. The Redlich-Kwong-Soave equation of state was used to calculate the thermodynamic properties. The cycle was simulated as a reversible as well as an irreversible process to clearly show the effect of the irreversibilities in each component of the cycle. At the irreversible process two cases were considered, changing the environmental temperature. However, in order to know the performance of the new cycle at different conditions of operation, the second irreversible case was analyzed varying the rectification temperatures, the isentropic efficiency of the turbine and the return temperature of the chilled water. Exergy effectiveness values of similar to 53% and similar to 51% were obtained for the irreversible cycles; with heat input requirements at temperatures of 125 and 150 degrees C. Solar collectors or waste heat are suggested as heat sources to operate the cycle. (c) 2006 Elsevier Ltd. All rights reserved. C1 UNAM, Sede CIE, Posgrado Ingn Energia, Temixco 62580, Morelos, Mexico. UNAM, Ctr Invest Energia, Temixco 62580, Morelos, Mexico. Inst Mexicano Petr, Grp Exergia, Mexico City 07730, DF, Mexico. UNAM, Fac Ingn, Mexico City, DF, Mexico. RP Vidal, A, UNAM, Sede CIE, Posgrado Ingn Energia, Privada Xochicalco S-N,Col Ctr, Temixco 62580, Morelos, Mexico. 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Iss. SI BP 3401 EP 3414 PG 14 SC Thermodynamics; Energy & Fuels GA 094NQ UT ISI:000241246600026 ER PT J AU Mossmann, S Jung, C AF Mossmann, S. Jung, C. TI Semiclassical approach to Bose-Einstein condensates in a triple well potential SO PHYSICAL REVIEW A LA English DT Article ID QUANTUM; DYNAMICS; INSTABILITY; ACETYLENE; SPECTRUM; ENERGY AB We present an approach for the analysis of Bose-Einstein condensates in a few mode approximation. This method has already been used to successfully analyze the vibrational modes in various molecular systems and offers a perspective on the dynamics in many particle bosonic systems. We discuss a system consisting of a Bose-Einstein condensate in a triple well potential. Such systems correspond to classical Hamiltonian systems with three degrees of freedom. The semiclassical approach allows a simple visualization of the eigenstates of the quantum system referring to the underlying classical dynamics. From this classification we can read off the dynamical properties of the eigenstates such as particle exchange between the wells and entanglement without further calculations. In addition, this approach offers insights into the validity of the mean-field description of the many particle system by the Gross-Pitaevskii equation, since we make use of exactly this correspondence in our semiclassical analysis. We choose a three mode system in order to visualize it easily and, moreover, to have a sufficiently interesting structure, although the method can also be extended to higher dimensional systems. C1 UNAM, Ctr Ciencias Fis, Cuernavaca 62251, Morelos, Mexico. RP Mossmann, S, UNAM, Ctr Ciencias Fis, Cuernavaca 62251, Morelos, Mexico. 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Rev. A PD SEP PY 2006 VL 74 IS 3 AR 033601 DI ARTN 033601 PG 16 SC Optics; Physics, Atomic, Molecular & Chemical GA 091ZP UT ISI:000241067100103 ER PT J AU Hernandez, JA Heyd, B Irles, C Valdovinos, B Trystram, G AF Hernandez, J. A. Heyd, B. Irles, C. Valdovinos, B. Trystram, G. TI Analysis of the heat and mass transfer during coffee batch roasting SO JOURNAL OF FOOD ENGINEERING LA English DT Article DE heat and mass transfer; coffee roasting; on-line measures ID CHICORY AB In this paper, an experimental and theoretical analysis of the heat and mass transfer was carried out to evaluate the coffee bean's temperature and moisture content during the roasting in batch system. Arabica coffee from Colombian origin was roasted using different air temperatures between 190 and 300 degrees C, during 10 min. Bean's temperature and weight loss have been measured on-line by robust sensors. The experimental results allowed better understanding of the phenomena that appears during roasting. For example, an evident increase of the bean's temperature curve tendency is observed when this one exceeds the 250 degrees C, it is probably due to the end of exothermic reactions and to the beginning of the bean burn. The experimental data of moisture shown a decrease of 10.5% d.b. to 0-7% d.b. A dynamic model is evaluated and analyzed to predict bean's temperature and moisture content during roasting. The results (simulations and experimental kinetics) were in good agreement. This model can be used for on-line estimation and control of coffee roasting. (c) 2006 Elsevier Ltd. All rights reserved. C1 Autonomous Univ Morelos State, Res Ctr Engn & Appl Sci CIICAp, Cuernavaca 62210, Morelos, Mexico. ENSIA, INAPG, Cemagref, Joint Res Unit Food Proc Engn, F-91744 Massy, France. Natl Inst Perinatol, Mexico City 11000, DF, Mexico. RP Hernandez, JA, Autonomous Univ Morelos State, Res Ctr Engn & Appl Sci CIICAp, Av Univ 1001 Col Chamilpa, Cuernavaca 62210, Morelos, Mexico. 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PD FEB PY 2007 VL 78 IS 4 BP 1141 EP 1148 PG 8 SC Engineering, Chemical; Food Science & Technology GA 092ZI UT ISI:000241136300005 ER PT J AU Verma, SP Andaverde, J Santoyo, E AF Verma, Surendra P. Andaverde, Jorge Santoyo, E. TI Application of the error propagation theory in estimates of static formation temperatures in geothermal and petroleum boreholes SO ENERGY CONVERSION AND MANAGEMENT LA English DT Article DE regression models; bottom-hole temperatures; ordinary least squares linear regression; weighted least squares linear regression; temperature uncertainties ID BOTTOM-HOLE TEMPERATURE; REGRESSION-MODELS; HEAT-FLOW; WELLS; LOGS AB We used the error propagation theory to calculate uncertainties in static formation temperature estimates in geothermal and petroleum wells from three widely used methods (line-source or Horner method; spherical and radial heat flow method; and cylindrical heat source method). Although these methods commonly use an ordinary least-squares linear regression model considered in this study, we also evaluated two variants of a weighted least-squares linear regression model for the actual relationship between the bottom-hole temperature and the corresponding time functions. Equations based on the error propagation theory were derived for estimating uncertainties in the time function of each analytical method. These uncertainties in conjunction with those on bottom-hole temperatures were used to estimate individual weighting factors required for applying the two variants of the weighted least-squares regression model. Standard deviations and 95% confidence limits of intercept were calculated for both types of linear regressions. Applications showed that static formation temperatures computed with the spherical and radial heat flow method were generally greater (at the 95% confidence level) than those from the other two methods under study. When typical measurement errors of 0.25 h in time and 5 degrees C in bottom-hole temperature were assumed for the weighted least-squares model, the uncertainties in the estimated static formation temperatures were greater than those for the ordinary least-squares model. However, if these errors were smaller (about 1% in time and 0.5% in temperature measurements), the weighted least-squares linear regression model would generally provide smaller uncertainties for the estimated temperatures than the ordinary least-squares linear regression model. Therefore, the weighted model would be statistically correct and more appropriate for such applications. We also suggest that at least 30 precise and accurate BHT and time measurements along with the respective errors should be obtained for a reliable application of the proposed regression procedure. (c) 2006 Elsevier Ltd. All rights reserved. C1 Natl Autonoma Univ Mexico, Ctr Invest Energia, Temixco 62580, Morelos, Mexico. RP Verma, SP, Natl Autonoma Univ Mexico, Ctr Invest Energia, Priv Xochicalco S-No,Col Ctr,Apartado Postal 34, Temixco 62580, Morelos, Mexico. 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Manag. PD DEC PY 2006 VL 47 IS 20 BP 3659 EP 3671 PG 13 SC Thermodynamics; Energy & Fuels; Mechanics; Physics, Nuclear GA 093AI UT ISI:000241139100018 ER PT J AU Han, JL Qi, W Dong, YC Li, SL Duan, LM Xu, HS Xu, HG Chen, RF Zhen, B Wu, HY Li, ZC Lu, XQ Kui, Z Ping, Z Liu, JC Xu, GJ Kun, SY AF Han Jian-Long Qi, Wang Dong Yu-Chuan Li Song-Lin Duan Li-Min Xu Hu-Shan Xu Hua-Gen Chen Ruo-Fu Zhen, Bai Wu He-Yu Li Zhi-Chang Lu Xiu-Qin Kui, Zhao Ping, Zhou Liu Jian-Cheng Xu Guo-Ji Kun, Sergey Yu TI Largely deformed dinuclear system formed in F-19+Al-27 dissipative collision SO CHINESE PHYSICS LETTERS LA English DT Article ID HEAVY-ION COLLISIONS; EXCITATION-FUNCTIONS; QUANTUM CHAOS; FLUCTUATIONS; DECOHERENCE; RESONANCES; SCATTERING; STATES; SPIN AB Excitation functions are measured for different charge products of the F-19+(27) Al reaction in the laboratory energy range 110.25-118.75MeV in steps of 250keV at theta(lab) = 57 degrees, 31 degrees and -29 degrees. The coherence rotation angular velocities of the intermediate dinuclear systems formed in the reaction are extracted from the cross section energy autocorrelation functions. Compared the angular velocity extracted from the experimental data with the ones deduced from the sticking limit, it is indicated that a larger deformation of the intermediate dinuclear system exists. C1 Chinese Acad Sci, Inst Modern Phys, Lanzhou 730000, Peoples R China. China Inst Atom Phys, Beijing 102413, Peoples R China. Chinese Acad Sci, Grad Sch, Beijing 100049, Peoples R China. Natl Autonomous Univ Mexico, Ctr Ciencias Fis, Cuernavaca, Morelos, Mexico. Australian Natl Univ, Ctr Nonlinear Phys, RSphysSE, Canberra, ACT 0200, Australia. RP Han, JL, Chinese Acad Sci, Inst Modern Phys, Lanzhou 730000, Peoples R China. EM wangqi@impcas.ac.cn CR ABBONDANNO U, 1991, PHYS REV C, V43, P1484 BASS R, 1980, NUCL REACTIONS HEAVY, P259 BERCEANU I, 1998, PHYS REV C, V57, P2359 BRAUNMUNZINGER P, 1982, PHYS REP, V87, P209 CINDRO N, 1980, J PHYS G, V6, P359 DONG YC, 2005, HIGH ENERG PHYS NUC, V29, P147 EISENBERG JM, 1987, NUCL THEORY, V1, P759 KUN SY, 1997, Z PHYS A-HADRON NUCL, V357, P255 KUN SY, 1997, Z PHYS A-HADRON NUCL, V357, P271 KUN SY, 1997, Z PHYS A-HADRON NUCL, V357, P367 KUN SY, 1999, PHYS REV LETT, V83, P504 PAPA M, 1995, Z PHYS A HADRON NUCL, V353, P205 PAPPALARDO G, 1988, NUCL PHYS A, V488, C395 RICHTER A, 1974, NUCL SPECTROSCOPY B, P343 ROSA AD, 1985, PHYS LETT B, V160, P239 SCHEID W, 1970, PHYS REV LETT, V25, P176 SUOMIJARVI T, 1987, PHYS REV C, V36, P181 WANG Q, 1993, CHINESE PHYS LETT, V10, P656 WANG Q, 1996, PHYS LETT B, V388, P462 WANG Q, 1999, CHINESE PHYS LETT, V12, P876 WANG Q, 2001, NUCL SCI TECHNOL, V12, P9 NR 21 TC 0 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0256-307X J9 CHIN PHYS LETT JI Chin. Phys. Lett. PD OCT PY 2006 VL 23 IS 10 BP 2706 EP 2709 PG 4 SC Physics, Multidisciplinary GA 091PH UT ISI:000241040300023 ER PT J AU Mazur, Z Carvajal-Martinez, A Munoz-Quezada, R Garcia-Illescas, R AF Mazur, Z. Carvajal-Martinez, A. Munoz-Quezada, R. Garcia-Illescas, R. TI Failure analysis of a leak-off oil pipe from injection valves of an off-shore operating diesel engine SO ENGINEERING FAILURE ANALYSIS LA English DT Article DE failure analysis; high cycle fatigue; diesel engine failures; oil pipe failure; diesel engine fire AB The failure analysis of a four-stroke 3000 kW off-shore operating diesel engine is presented. The failure occurred during engine normal operation period in the leak-off oil pipe from the injection valves, which experienced a fracture through the pipe wall and a diesel engine fire as a result. A detailed analysis of all elements which had an influence on the failure initiation was carried out, namely leak-off oil pipe vibration level, pipe stress level, presence of corrosion pits on the pipe external surface under the zinc coating and engine components temperature distribution in the failure zone, It was found that the crack initiation and propagation of the leak-off oil pipe from injection valves was driven by a fatigue mechanism, which was facilitated by loose pipe supports (excessive pipe vibration) and corrosion pits on the pipe surface that acted as stress concentrators. The contact of leak-off atomized oil due to the pipe through wall fracture with the hot engine exhaust muff (390 degrees C approximately) caused local fire of the diesel engine. (C) 2005 Elsevier Ltd. All rights reserved. C1 Inst Invest Elect, Cuernavaca 62490, Morelos, Mexico. RP Mazur, Z, Inst Invest Elect, Calle Reforma 113,Col Palmira, Cuernavaca 62490, Morelos, Mexico. EM mazur@iie.org.mx CR 2001, PROGRAM MATHCAD PROF *INT LTD, 2001, PROGR NCODE *WARTS SWED AB, 1999, SERV DAT FUEL SYST *WARTS SWED, 1992, 9193909800 E WARTS S ARDON G, 2004, COMMUNICATION 0104 HUTCHINGS FR, 1981, FAILURE ANAL BRIT EN, P99 VISWANATHAN R, 1995, DAMAGE MECH LIFE ASS NR 7 TC 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 1350-6307 J9 ENG FAIL ANAL JI Eng. Fail. Anal. PD JAN PY 2007 VL 14 IS 1 BP 196 EP 208 PG 13 SC Engineering, Mechanical; Materials Science, Characterization & Testing GA 089VQ UT ISI:000240910000018 ER PT J AU Villamizar, W Casales, M Gonzales-Rodriguez, JG Martinez, L AF Villamizar, W. Casales, M. Gonzales-Rodriguez, J. G. Martinez, L. TI An EIS study of the effect of the pedant group in imidazolines as corrosion inhibitors for carbon steel in CO2 environments SO MATERIALS AND CORROSION-WERKSTOFFE UND KORROSION LA English DT Article ID DIOXIDE CORROSION; MILD-STEEL; ACID-MEDIA; IMPEDANCE AB Electrochemical impedance spectroscopy (EIS) measurements were carried out to study the corrosion inhibition of carbon steel in 3% NaCl with and without diesel saturated with CO2 at 50 degrees C. The inhibitors examined were hydroxyethyl (HEI-18), amino ethyl (AEI-18), and amide ethyl imidazolines (AMEI-18). When the oily phase, i.e diesel, is absent, the inhibition efficiency of the imidazolines is low, around 80 %. It was found, however, that the inhibition dramatically increased with the presence of the oily phase, because the imidazolines are able to act as both emulsifiers and corrosion inhibitors. Experimental results showed an increase in the film resistance (R-f), charge transfer resistance (R-ct), capacitance of the film and the capacitance of the double layer values with the addition of inhibitor in presence of the oily phase also in several orders of magnitude. The most effective inhibitor in presence of diesel is a solution of AMEI-18, as the oily phase is carried to the surface also. This is due to the presence of two large alkyl groups than the only chain present in the HEI-18 and AEI-18 imidazolines with better hydrophobic properties associated with the formation of a protective film that reduces drastically the corrosion process. The effects of the interaction of inhibitors with hydrocarbons and the correlation on the performance of inhibitor films have been examined. C1 UAEM, CIICAp, Cuernavaca 62210, Morelos, Mexico. UNAM, Ctr Ciencias Fis, Cuernavaca 62210, Morelos, Mexico. RP Gonzales-Rodriguez, JG, UAEM, CIICAp, Univ 1001,Col Chamilpa, Cuernavaca 62210, Morelos, Mexico. EM ggonzalez@uaem.mx CR CRUZ J, 2001, INT J QUANTUM CHEM, V85, P1911 CRUZ J, 2004, J ELECTROANAL CHEM, V566, P111 DEMARCO R, 2002, CORROSION, V58, P354 DEMORAES FD, 2000, P NACE CORR 2000 NAC HONG T, 2001, CORROS SCI, V43, P1839 JOVANCICEVIC V, 1999, CORROSION, V55, P449 LOPEZ DA, 2003, CORROS SCI, V45, P845 LOPEZ DA, 2005, CORROS SCI, V47, P735 POPOVA A, 1996, LANGMUIR, V12, P2083 RAMACHANDRAN S, 1999, CORROSION, V55, P259 ROBERGE PR, 2000, HDB CORROSION ENG TAN YJ, 1996, CORROS SCI, V38, P1545 TSAI CH, 1993, CORROSION, V49, P726 WANG D, 1999, CORROS SCI, V49, P1911 ZHANG XY, 2001, CORROS SCI, V43, P1417 NR 15 TC 0 PU WILEY-V C H VERLAG GMBH PI WEINHEIM PA PO BOX 10 11 61, D-69451 WEINHEIM, GERMANY SN 0947-5117 J9 MATER CORROS JI Mater. Corros. PD SEP PY 2006 VL 57 IS 9 BP 696 EP 704 PG 9 SC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering GA 087XB UT ISI:000240775000003 ER PT J AU Martinez-Morales, A Alia-Tejacal, I Lopez-Martinez, V Bautista, C AF Martinez-Morales, Arturo Alia-Tejacal, Iran Lopez-Martinez, Victor Bautista, Cecilio TI Quality of sapote mamey fruits treated with hot water and stored at 12 degrees C SO HORTSCIENCE LA English DT Meeting Abstract C1 Univ Zona Cultura, Univ Juarez Autonoma Tabasco, Tabasco 86040, Mexico. Univ Autonoma Edo Morelos, Cuernavaca 62210, Morelos, Mexico. Univ Autonoma Chapingo, Chapingo 56230, Texcoco, Mexico. Univ Autonoma Estado Puebla, Cuernavaca 62210, Morelos, Mexico. NR 0 TC 0 PU AMER SOC HORTICULTURAL SCIENCE PI ALEXANDRIA PA 113 S WEST ST, STE 200, ALEXANDRIA, VA 22314-2851 USA SN 0018-5345 J9 HORTSCIENCE JI Hortscience PD JUL PY 2006 VL 41 IS 4 BP 1051 EP 1052 PG 2 SC Horticulture GA 063UP UT ISI:000239045700491 ER PT J AU Hernandez-Salazar, M Agama-Acevedo, E Sayago-Ayerdi, SG Tovar, J Bello-Perez, LA AF Hernandez-Salazar, M. Agama-Acevedo, E. Sayago-Ayerdi, S. G. Tovar, J. Bello-Perez, L. A. TI Chemical composition and starch digestibility of tortillas prepared with non-conventional commercial nixtamalized maize flours SO INTERNATIONAL JOURNAL OF FOOD SCIENCES AND NUTRITION LA English DT Article DE tortilla; blue tortilla; bean; nixtamalized maize flours; starch digestibility ID RESISTANT STARCH; PHASEOLUS-VULGARIS; GLYCEMIC INDEX; ZEA-MAYS; STORAGE; BEANS; VARIETIES; LEGUMES; FOODS AB Non- conventional nixtamalized maize flours elaborated by a factory in Mexico were used for tortilla preparation. Tortillas were stored at 4 degrees C for up to 72 h and the total starch, available starch, resistant starch and retrograded resistant starch were assessed. The traditional white tortilla, used as a control, showed higher protein and fat contents than blue maize tortilla, whereas a maize-bean mixed tortilla had the highest protein, ash and fat contents. Lower total starch was obtained in the maize-bean tortilla than in white and blue maize tortillas. The available starch content in all tortillas decreased with the cold-storage, although the change was more marked for blue-maize tortillas. The maize-bean mixed tortillas exhibited the lowest in vitro digestibility, which is consistent with the relatively high resistant starch levels in the bean. Differences in resistant starch content were found between the two maize tortillas, which might be related to the softer texture of blue-maize tortilla. The starch digestibility features of these new types of nixtamalized maize flours open up the possibility of producing tortillas with variable nutritional properties. C1 Inst Politecn Nacl, Ctr Desarrollo Prod Biot, Yautepec, Morelos, Mexico. Inst Tecnol Acapulco, Acapulco, Guerrero, Mexico. Cent Univ Venezuela, Fac Ciencias, Inst Expt Biol, Caracas, Venezuela. RP Bello-Perez, LA, Km 8-5,Carretera Yautepec Jojutla,Colonia San Isi, Yautepec 62731, Morelos, Mexico. EM labellop@ipn.mx CR *AACC, 2000, APPR METH AACC AGAMAACEVEDO E, 2004, NAHRUNG, V48, P38 ALMEIDADOMINGUEZ HD, 1996, CEREAL FOOD WORLD, V41, P624 BEDOLLA S, 1984, CEREAL FOOD WORLD, V29, P732 BILIADERIS CG, 1991, CAN J PHYSIOL PHARM, V69, P60 BRAVO L, 1999, FOOD CHEM, V64, P185 CAMPASBAYPOLI ON, 2002, STARCH-STARKE, V54, P358 CAMPUSBAYPOLI ON, 1999, STARCH-STARKE, V51, P173 CORTESGOMEZ A, 2005, J FOOD ENG, V66, P273 ENGLYST HN, 1992, EUR J CLIN NUTR S2, V46, P33 FARHAT IA, 2001, STARCH-STARKE, V53, P431 GARCIAOSORIO C, 1997, ARCH LATINOAM NUTR, V47, P377 GONI I, 1996, FOOD CHEM, V56, P445 GONI I, 1997, NUTR RES, V17, P427 HERNANDEZLAUZARDO AN, 2004, STARCH-STARKE, V56, P357 HOLM J, 1986, STARCH-STARKE, V38, P224 MANEK RV, 2005, STARCH-STARKE, V57, P55 MENDEZMONTEALVO G, 2005, AGROCIENCIA-MEXICO, V39, P267 OSORIODIAZ P, 2005, J SCI FOOD AGR, V85, P499 PAREDESLOPEZ O, 2000, ALIMENTOS MAGICOS CU RENDONVILLALOBOS R, 2002, CEREAL CHEM, V79, P340 REYES CP, 1990, MAIZ CULTIVO REYESMORENO C, 1993, CRIT REV FOOD SCI, V33, P227 ROSIN PM, 2002, J FOOD COMPOS ANAL, V15, P367 SAURACALIXTO F, 1993, J FOOD SCI, V58, P642 SAYAGOAYERDI SG, 2005, J AGR FOOD CHEM, V53, P1281 TOVAR J, 1994, ARCH LATIN NUTR, V44, P36 TOVAR J, 1996, J AGR FOOD CHEM, V44, P2642 TOVAR J, 2002, FOOD CHEM, V76, P455 VARGASTORRES A, 2004, J FOOD COMPOS ANAL, V17, P605 WHISTLER RL, 1984, STARCH CHEM TECHNOLO, P154 WURSCH P, 1986, AM J CLIN NUTR, V43, P25 YAU JC, 1994, CEREAL FOOD WORLD, V39, P396 ZAZUETAMORALES JJ, 2000, J SCI FOOD AGR, V81, P1379 NR 34 TC 0 PU TAYLOR & FRANCIS LTD PI ABINGDON PA 4 PARK SQUARE, MILTON PARK, ABINGDON OX14 4RN, OXON, ENGLAND SN 0963-7486 J9 INT J FOOD SCI NUTR JI Int. J. Food Sci. Nutr. PD FEB-MAR PY 2006 VL 57 IS 1-2 BP 143 EP 150 PG 8 SC Food Science & Technology; Nutrition & Dietetics GA 074MJ UT ISI:000239816200014 ER PT J AU Martinez, H AF Martinez, H. TI Absolute cross sections for the production of positive atomic ions from dissociative collisions of H-3(+), D-3(+) and HD2+ in He SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS LA English DT Article DE cross section; collision induced dissociation; H-3(+); HD2+; D-3(+); fragmentation mechanism ID RECOMBINATION; ELECTRONS; PLASMA; H-3+ AB Absolute total cross sections are reported for the production of positive atomic ions from dissociative collisions of 1-5 keV H-3(+), D-3(+) and HD2+ with He for scattering angles up to 5 degrees. The cross sections are of 10(-17) cm(2) for all the processes studied in this work. In order to investigate the mass effect in the dissociation processes, the data are plotted as a function of the projectile speed. The cross sections from HD2+ are normalized to compensate for the relative fragment yield making possible the comparison of the mass effect over the dissociation processes, i.e. 3 sigma(H+) and 1.5 sigma(D+) have been considered. For equivelocity incident H-3(+) D-3(+) and HD2+, the H+ and D+ formation cross sections were the same within the accuracy of the experiment. (c) 2006 Elsevier B.V. All rights reserved. C1 Univ Nacl Autonoma Mexico, Ctr Ciencias Fis, Cuernavaca 62210, Morelos, Mexico. RP Martinez, H, Univ Nacl Autonoma Mexico, Ctr Ciencias Fis, Apartado Postal 48-3, Cuernavaca 62210, Morelos, Mexico. EM hm@fis.unam.mx CR CARRINGTON A, 1984, J CHEM PHYS, V81, P91 FARIZON M, 1992, PHYS REV A, V45, P179 GLOSIK J, 2003, PLASMA SOURCES SCI T, V12, S117 GOUGOUSI T, 1995, INT J MASS SPECTROM, V149, P131 JALBERT G, 1992, PHYS REV A, V46, P2957 JALBERT G, 1993, PHYS REV A, V47, P4768 JANEV RK, 1991, COMMENTS AT MOL PHYS, V26, P83 MARTINEZ H, 1987, PHYS REV A, V36, P5425 MARTINEZ H, 2004, PHYS REV A, V69 MCCALL BJ, 1999, ASTROPHYS J 1, V522, P338 PEART B, 1979, J PHYS B ATOM MOL PH, V12, P3441 QAYYUM A, 2003, CHEM PHYS LETT, V372, P166 STRASSER D, 2004, PHYS REV A, V69 TENNYSON J, 1990, J CHEM PHYS, V92, P3005 WATSON WD, 1973, APJ, V183, L17 WIESE LM, 1997, PHYS REV LETT, V79, P4982 WILLIAMS JF, 1966, PHYS REV, V149, P64 NR 17 TC 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-583X J9 NUCL INSTRUM METH PHYS RES B JI Nucl. Instrum. Methods Phys. Res. Sect. B-Beam Interact. Mater. Atoms PD AUG PY 2006 VL 249 BP 89 EP 91 PG 3 SC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Atomic, Molecular & Chemical; Physics, Nuclear GA 070ST UT ISI:000239545000023 ER PT J AU Mazur, Z Hernandez-Rossette, A Garcia-Illescas, R AF Mazur, Z. Hernandez-Rossette, A. Garcia-Illescas, R. TI Investigation of the failure of the L-0 blades SO ENGINEERING FAILURE ANALYSIS LA English DT Article DE failure analysis; high cycle fatigue; steam turbine failures; L-0 blade failure; metallurgical examination ID TURBINE AB A last stage (L-0) turbine blades failure was experienced at the 110 MW geothermal unit after 1 year of operation period. This unit has two tandem-compound intermediate/low-pressure turbines (turbine A and turbine B) with 23 in./3600 rpm last-stage blades. There were flexible blades continuously coupled 360 degrees around the row by loose cover segment at the tip and loose sleeve and lug at the mid-span (pre-twist design). The failed blades were in the L-0 row of the LP turbine B connected to the generator. The visual examination indicated that the group of 12 L-0 blades of rotor B on the generator side was bent and another group of 5 blades at 140 degrees from the first damaged group was also bent. The cover segments were spread out from the damaged blades and had cracks. Laboratory evaluation of the cracking in the cover segments indicates the failure mechanism to be high cycle fatigue (HCF), initiating at the cover segment holes outer fillet radius. The L-0 blades failure investigation was carried out. The investigation included a metallographic analysis of the cracked cover segments and bent blades, Finite Element Method (FEM) stress and natural frequency analysis (of blades/cover segments), fracture mechanics and crack propagation analysis. This paper provides an overview of the L-0 blades failure investigation, which led to the identification of the blades vibrations within the range 250-588 Hz induced due to unstable flow excitation (stall flutter) as the primary contribution to the observed failure. (C) 2005 Elsevier Ltd. All rights reserved. C1 Inst Invest Elect, Cuernavaca 62490, Morelos, Mexico. RP Mazur, Z, Inst Invest Elect, Av Reforma 113, Cuernavaca 62490, Morelos, Mexico. EM mazur@iie.org.mx CR *INT LTD, 2001, PROGR NCODE VERS 1 COFFER JI, 1996, GER3713E GE POW SYST FILSINGER D, 2002, J TURBOMACH, V124, P125 GRIFFIN JK, 96GT402 ASME HSIAOWEI D, 2003, P ASME TURB EXP 2003 KIELB JJ, 2003, J ENG GAS TURB POWER, V125, P102 KIELB R, 2003, P ASME TURB EXP 2003 KUBIAK JA, 1995, ASME PWR, V28, P289 ORTOLANO RJ, 1991, ASME PWR, V13, P147 PANOVSKY J, 2000, J ENG GAS TURB POWER, V122, P89 PURI A, 1995, ASME PWR, V28, P403 SEXTRO W, 2000, 2000GT540 ASME SEXTRO W, 2002, LECT NOTES APPL MECH, V3 SILKOWSKI PD, 2001, P ASME TURB EXP 2001 SUZUKI T, 2005, ASME POWER, P577 SZWEDOWICZ J, 2003, P ASME TURB EXP 2003 TROYANOWSKIJ BM, 1985, PAROVYE GAZOVYE TURB VOGT DM, 2002, 16 S MEAS TECHN TRAN NR 18 TC 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 1350-6307 J9 ENG FAIL ANAL JI Eng. Fail. Anal. PD DEC PY 2006 VL 13 IS 8 BP 1338 EP 1350 PG 13 SC Engineering, Mechanical; Materials Science, Characterization & Testing GA 073CC UT ISI:000239719200015 ER PT J AU Cuevas-Rodriguez, EO Verdugo-Montoya, NM Angulo-Bejarano, PI Milan-Carrillo, J Mora-Escobedo, R Bello-Perez, LA Garzon-Tiznado, JA Reyes-Moreno, C AF Cuevas-Rodriguez, E. O. Verdugo-Montoya, N. M. Angulo-Bejarano, P. I. Milan-Carrillo, J. Mora-Escobedo, R. Bello-Perez, L. A. Garzon-Tiznado, J. A. Reyes-Moreno, C. TI Nutritional properties of tempeh flour from quality protein maize (Zea mays L.) SO LWT-FOOD SCIENCE AND TECHNOLOGY LA English DT Article DE nutritional; quality protein maize; tempeh ID RESISTANT STARCH; RHIZOPUS-OLIGOSPORUS; DIGESTIBILITY; FERMENTATION; ACID; FOOD; TORTILLA; SOYBEANS; COOKING; MASA AB The objective of this investigation was to evaluate physico-chemical and nutritional properties of tempeh flour from a quality protein maize (QPM). In comparison to untreated QPM, the QPM tempeh flour showed a higher (P <= 0.05) gelatinization temperature (81.7 vs 73.9 degrees C), and resistant starch (4.24 vs 1.9 g/100 g dry flour), and a lower (P <= 0.05) gelatinization enthalpy (1.94 vs 2.74 J/g) and total starch content (56.9 vs 62.6 g/100 g dry flour). The essential amino acids (EAAs) content of raw QPM flour was improved by the solid-state fermentation process. The contents of His, Ile, and Leu increased (P < 0.05) in 0.81, 0.52, and 1.46 g/100g protein, respectively. The total sulphur and total aromatic EAAs increased (P <= 0.05) in 0.55 and 3.45g/100g protein, respectively. In untreated QPM flour, the first and second limiting EAAs were Lys and Trp, with EAAs score of 0.72. First and second limiting EAAs in QPM tempeh flour were Trp and Lys, with an EAAs score of 0.84. The SSF process increased (P <= 0.05) nutritional indicators as follows: protein efficiency ratio (PER) from 1.78 to 2.10, calculated PER from 1.43 to 1.74, and protein digestibility corrected amino acid score from 0.55 to 0.83. It is concluded that based mainly on its nutritive value, fermented flour may be considered for the fortification of widely consumed cereal-based food product (tortillas, bread, cookies, atoles). (c) 2005 Swiss Society of Food Science and Technology. Published by Elsevier Ltd. All rights reserved. C1 Univ Autonoma Sinaloa, Fac Ciencias Quim Biol, Programa Reg Noreste Doctorado Biotecnol, Culiacan 80060, Sinaloa, Mexico. Inst Politecn Nacl, Escuela Nacl Ciencias Biol, Dept Grad Alimentos, Mexico City 07738, DF, Mexico. Inst Politecn Nacl, Ctr Desarrollo Prod Bioticos, Yautepec, Morelos, Mexico. Inst Nacl Invest Forestales Agr & Pecuarias, Ctr Invest Reg Noroeste, Valle Culiacan, Sinaloa, Mexico. RP Reyes-Moreno, C, Univ Autonoma Sinaloa, Fac Ciencias Quim Biol, Programa Reg Noreste Doctorado Biotecnol, Lichis 1986,La Campina, Culiacan 80060, Sinaloa, Mexico. EM creyes@uas.uasnet.mx CR *AACC, 1995, APPR METH AM ASS CER *AOAC, 1998, OFF METH AN *CIMMYT, 1985, CIMMYT RES HIGH LIGH *FAO WHO, 1991, PROT QUAL EV, P66 *INIFAP, 1999, QPM MAIZ ALT CAL PRO *STAT EASE INC, 2002, DES EXP VERS 6 04 ADDO K, 1996, FOOD CHEM, V57, P377 ANDERSON RA, 1969, CEREAL SCI TODAY, V14, P11 ASP NG, 1996, NUTR RES REV, V9, P1 BARRAGANSALGADO ML, 2000, CEREAL CHEM, V77, P652 BEDOLLA S, 1982, CEREAL FOODS WORLD, V27, P219 BELLOPEREZ IA, 2002, AGROCIENCIA, V36, P319 BILIADERIS CG, 1992, FOOD TECHNOL-CHICAGO, V46, P98 BINDLINGMEYER BA, 1984, J CHROMATOGR, V336, P93 BUZZIGOLI G, 1990, J CHROMATOGR, V507, P85 COHEN SA, 1988, ANAL BIOCHEM, V174, P1 CUEVASRODRIGUEZ EO, 2004, LEBENSM-WISS TECHNOL, V37, P59 EGGUM BO, 1973, PUBLICATION REP NATL, V406 EGOUNLETY M, 2003, J FOOD ENG, V56, P249 GARCIAALONSO A, 1999, FOOD CHEM, V66, P181 GONI I, 1997, NUTR RES, V17, P427 HACHMEISTER KA, 1993, CRIT REV MICROBIOL, V19, P137 HAMAD AM, 1979, J FOOD SCI, V44, P456 HENLEY EC, 1994, FOOD TECHNOL-CHICAGO, V48, P74 HIRS CHW, 1967, METHOD ENZYMOL, V11, P197 HSU HW, 1977, J FOOD SCI, V42, P1269 HSU HW, 1978, FOOD TECHNOL, V32, P69 HUGLI TE, 1972, J BIOL CHEM, V247, P2828 LINDER M, 1997, J FOOD SCI, V62, P183 MORAESCOBEDO R, 1994, LEBENSMITTELWISSENSC, V24, P241 MOREYRA R, 1981, J FOOD SCI, V46, P1948 MUGULA JK, 1992, INT J FOOD SCI NUTR, V43, P113 MUGULA JK, 2000, INT J FOOD SCI NUTR, V51, P269 NARAYANA K, 1982, J FOOD SCI, V47, P1534 ORTEGA EI, 1983, CEREAL CHEM, V60, P107 PAREDESLOPEZ O, 1988, CRC C R F S, V27, P159 PAREDESLOPEZ O, 1989, J FOOD SCI, V54, P968 PAREDESLOPEZ O, 2000, ALIMENTOS MAGICOS CU RENDONVILLALOBOS R, 2002, CEREAL CHEM, V79, P340 SARWAR G, 1990, J ASSOC OFF ANA CHEM, V73, P103 SATTERLEE LD, 1979, J AM OIL CHEM SOC, V56, P109 SAURACALIXTO F, 1993, J FOOD SCI, V58, P642 SPROULE AM, 1988, CEREAL FOODS WORLD, V33, P233 SULLIVAN DM, 1993, METHODS ANAL NUTR LA, P425 WANG HL, 1968, J NUTR, V96, P109 NR 45 TC 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0023-6438 J9 LWT-FOOD SCI TECHNOL JI LWT-Food Sci. Technol. PY 2006 VL 39 IS 10 BP 1072 EP 1079 PG 8 SC Food Science & Technology GA 062UX UT ISI:000238971400004 ER PT J AU Garcia, MAL Smit, MA AF Lucio Garcia, M. A. Smit, Mascha A. TI Study of electrodeposited polypyrrole coatings for the corrosion protection of stainless steel bipolar plates for the PEM fuel cell SO JOURNAL OF POWER SOURCES LA English DT Article DE PEM fuel cell; bipolar plates; polypyrrole; corrosion; stainless steel AB Polypyrrole coatings were prepared on stainless steel SS304 in order to study the corrosion protection provided by the conductive polymer in a simulated PEM fuel cell environment. The polypyrrole was deposited by electrochemical polymerization with 0.04, 0.07 and 0. 14 g cm(-2) onto SS304 electrodes. Polarization curves, taken after immersion for 1, 3 or 24 It in 0. 1 M sulphuric acid at either room temperature or 60 degrees C were used as an accelerated test. For short immersion times, it was found that corrosion current densities (at free corrosion potentials), diminished up to 2 orders of magnitude for samples tested at room temperature and up to 4 orders of magnitude for samples tested at 60 degrees C. Furthermore, at potentials in the range of the PEM fuel cell anode potential, corrosion rates also decreased up to several orders of magnitude. However, these protective properties were lost at longer times of immersion. The addition of DBSA to the polypyrrole coatings did lead to improved corrosion current densities at the free corrosion potential, however due to the loss of passivity of these samples, the corrosion rates in the potential range applicable to PEM fuel cells were either similar to or larger than bare metal. SEM was used to determine the morphology of the coatings and showed that the most homogeneous coating was obtained for 0.07 g cm(-2) polypyrrole, without the incorporation of DBSA. (c) 2005 Elsevier B.V. All rights reserved. C1 Ctr Invest Cientif Yucatan, Unidad Mat, Merida 97200, Yucatan, Venezuela. UNAM, CIE, Temixco 62580, Morelos, Mexico. RP Smit, MA, Ctr Invest Cientif Yucatan, Unidad Mat, Calle 43 130,Col Chuburna Hidalgo, Merida 97200, Yucatan, Venezuela. EM mascha@cicy.mx CR DAVIES DP, 2000, J POWER SOURCES, V86, P237 DEBERRY DW, 1985, J ELECTROCHEM SOC, V132, P132 GRGUR BN, 1998, PROG ORG COAT, V33, P1 HERMANN A, 2005, INT J HYDROGEN ENERG, V30, P1297 HERMAS AA, 2005, ELECTROCHIM ACTA, V50, P3640 HERRASTI P, 2001, APPL SURF SCI, V172, P276 HUDSON RM, 1966, MET FINISH, V64, P63 MAKKUS RC, 2000, J POWER SOURCES, V86, P274 MEHTA V, 2003, J POWER SOURCES, V114, P32 SKOTHEIM TA, 1998, HDB CONDUCTING POLYM WANG HL, 2004, J POWER SOURCES, V128, P193 WESSLING B, 1994, ADV MATER, V6, P226 WIND J, 2002, J POWER SOURCES, V105, P256 NR 13 TC 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0378-7753 J9 J POWER SOURCES JI J. Power Sources PD JUL 14 PY 2006 VL 158 IS 1 BP 397 EP 402 PG 6 SC Electrochemistry; Energy & Fuels GA 062SG UT ISI:000238964200047 ER PT J AU Wang, Q Han, JL Xiao, ZG Xu, HS Sun, ZY Hu, ZG Zhang, XY Wang, HW Mao, RS Yuan, XH Xu, ZG Zhao, TC Zhang, HB Xu, HG Qi, HR Wang, Y Jia, F Wu, LJ Ding, XL Gao, Q Gao, H Li, SL Bai, Z Xiao, GQ Jin, GM Ren, ZZ Zhou, SG Sergey, YK AF Wang Qi Han Jian-Long Xiao Zhi-Gang Xu Hu-Shan Sun Zhi-Yu Hu Zheng-Guo Zhang Xue-Ying Wang Hong-Wei Mao Rui-Shi Yuan Xiao-Hua Xu Zhi-Guo Zhao Tie-Cheng Zhang Hong-Bin Xu Hua-Gen Qi Hui-Rong Wang Yue Jia Fei Wu Li-Jie Ding Xian-Li Gao Qi Gao Hui Li Song-Lin Bai Zhen Xiao Guo-Qing Jin Gen-Ming Ren Zhong-Zhou Zhou Shan-Gui Sergey Yu -Kun TI Exotic behaviour of angular dispersion of weakly bound nucleus F-17 at small angles SO CHINESE PHYSICS LETTERS LA English DT Article ID CROSS-SECTIONS; PROTON HALO; ELASTIC-SCATTERING; RICH NUCLEI; SHELL; STATE AB The differential cross sections of F-17 and O-17 elastic scattering products on Pb-208 have been measured at the Radioactive Ion Beam Line at Lanzhou (RIBLL). Two angular dispersion plots of ln(d sigma/d theta) versus theta 2 are obtained from the angular distribution of the elastic scattering differential cross sections. The angular dispersion plot exhibits a clear turning point for F-17 in the range of small scattering angles 6 degrees-20 degrees due to its exotic structure, but for O-17, the turning point is not observed in the same angular range. The experimental results have been compared with previous data of other groups. Systematical analysis on the available data supports the above conclusion that there is an exotic behaviour of the angular dispersion plot of weakly bound nuclei with halo or skin structure as compared with that of the ordinary nuclei near stable line. Therefore the turning point of the angular dispersion plot appears at small angle for weakly bound nuclei with halo or skin structure, and can be used as a new probe to investigate the halo and skin phenomena of weakly bound nuclei. C1 Chinese Acad Sci, Inst Modern Phys, Lanzhou 730000, Peoples R China. Chinese Acad Sci, Grad Sch, Beijing 100049, Peoples R China. Ctr Theoret Nucl Phys, Natl Lab Heavy Ion Accelerator, Lanzhou 730000, Peoples R China. Nanjing Univ, Dept Phys, Nanjing 210008, Peoples R China. Chinese Acad Sci, Inst Theoret Phys, Beijing 100080, Peoples R China. UNAM, Ctr Ciencias Fis, Cuernavaca, Morelos, Mexico. Australian Natl Univ, Ctr Nonlinear Phys, RSPyhsSE, Canberra, ACT 0200, Australia. RP Wang, Q, Chinese Acad Sci, Inst Modern Phys, Lanzhou 730000, Peoples R China. EM wangqi@impcas.ac.cn CR BAKER SD, 1967, PHYS REV, V161, P1200 BROWN BA, 1996, PHYS LETT B, V381, P391 CAI XZ, 2002, PHYS REV C, V65 KAKUEE OR, 2003, NUCL PHYS A, V728, P339 LIN CJ, 2005, PHYS REV C, V66 LIU ZH, 2004, CHINESE PHYS LETT, V21, P1711 MITTIG W, 1987, PHYS REV LETT, V59, P1889 MORLOCK R, 1997, PHYS REV LETT, V79, P3837 NAVIN A, 1998, PHYS REV LETT, V81, P5089 REN ZZ, 1996, PHYS REV C, V53, R572 REN ZZ, 1998, PHYS REV C, V57, P2752 SAINTLAURENT MG, 1989, Z PHYS A ATOMS NUCL, V332, P457 STRUTINSKY VM, 1973, PHYS LETT B, V44, P245 SUN Z, 2003, NUCL INSTRUM METH A, V503, P496 TANIHATA I, 1985, PHYS REV LETT, V55, P2676 WARNER RE, 1995, PHYS REV C, V52, P1166 ZHANG HY, 2002, NUCL PHYS A, V707, P303 NR 17 TC 0 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0256-307X J9 CHIN PHYS LETT JI Chin. Phys. Lett. PD JUL PY 2006 VL 23 IS 7 BP 1731 EP 1733 PG 3 SC Physics, Multidisciplinary GA 063EN UT ISI:000238999500021 ER PT J AU Sreevidya, VS Rao, CS Sullia, SB Ladha, JK Reddy, PM AF Sreevidya, V. S. Rao, C. Srinivasa Sullia, S. B. Ladha, Jagdish K. Reddy, Pallavolu M. TI Metabolic engineering of rice with soybean isoflavone synthase for promoting nodulation gene expression in rhizobia SO JOURNAL OF EXPERIMENTAL BOTANY LA English DT Article DE flavonoids; isoflavone synthase; nod gene induction; Oryza sativa; rhizobia ID BRADYRHIZOBIUM-JAPONICUM; NOD GENES; BIOSYNTHESIS; INDUCTION; NGR234; TRANSCRIPTION; COLONIZATION; FLAVONOIDS; TISSUES; ENZYME AB Isoflavonoids are derived from a flavonone intermediate, naringenin, that is ubiquitously present in plants, and play a critical role in plant development and defence response. Isoflavonoids secreted by the legumes also play an important role in promoting the formation of nitrogen-fixing nodules by symbiotic rhizobia. In these plants, the key enzyme that redirects phenylpropanoid pathway intermediates from flavonoids to isoflavonoids is the cytochrome P450 mono-oxygenase, isoflavone synthase. In an effort to develop a rice variety possessing the ability to induce nodulation (nod) genes in rhizobia, the IFS gene from soybean was incorporated into rice (Oryza sativa L. cv. Murasaki R86) under the control of the 35S promoter. The presence of IFS in transgenic rice was confirmed by PCR and Southern blot analysis. Analyses of the 35S-IFS transgenic lines demonstrated that the expression of the IFS gene led to the production of the isoflavone genistein in rice tissues. These results showed that the soybean IFS gene-expressed enzyme is active in the R86 rice plant, and that the naringenin intermediate of the anthocyanin pathway is available as a substrate for the introduced foreign enzyme. The genistein produced in rice cells was present in a glycoside form, indicating that endogenous glycosyltransferases were capable of recognizing genistein as a substrate. Studies with rhizobia demonstrated that the expression of isoflavone synthase confers rice plants with the ability to produce flavonoids that are able to induce nod gene expression, albeit to varied degrees, in different rhizobia. C1 Int Rice Res Inst, Manila, Philippines. Bangalore Univ, Dept Microbiol & Biotechnol, Bangalore 560056, Karnataka, India. Univ Nacl Autonoma Mexico, Programa Genom Funct Eucariotes, Ctr Ciencias Genom, Cuernavaca 62210, Morelos, Mexico. RP Reddy, PM, Int Rice Res Inst, DAPO Box 7777, Manila, Philippines. EM pmreddy@ccg.unam.mx CR AKASHI T, 1999, PLANT PHYSIOL, V121, P821 BANFALVI Z, 1988, MOL GEN GENET, V214, P420 BASSAM BJ, 1988, MOL PLANT MICROBE IN, V1, P161 BROUGHTON WJ, 2000, J BACTERIOL, V182, P5641 DELLAPORTA SL, 1983, PLANT MOL BIOL REP, V1, P19 DIXON RA, 1999, TRENDS PLANT SCI, V4, P394 FADER GM, 2000, 0044909, WO GOETHALS K, 1989, MOL GEN GENET, V219, P289 GRAHAM TL, 1991, PLANT PHYSIOL, V95, P594 GROTEWOLD E, 1998, PLANT CELL, V10, P721 JUNG W, 2000, NAT BIOTECHNOL, V18, P208 JUNG WS, 2003, J PLANT BIOTECHNOL, V5, P149 KAWASAKI T, 1999, P NATL ACAD SCI USA, V96, P10922 KOBAYASHI H, 2004, MOL MICROBIOL, V51, P335 KOCHS G, 1986, EUR J BIOCHEM, V155, P311 KOSSLAK RM, 1987, P NATL ACAD SCI USA, V84, P7428 LADHA JK, 2000, QUEST NITROGEN FIXAT, P1 LADHA JK, 2003, PLANT SOIL, V252, P151 LESTRANGE KK, 1990, MOL PLANT MICROBE IN, V3, P214 LEWIN A, 1990, MOL PLANT MICROBE IN, V3, P317 LIU CJ, 2002, P NATL ACAD SCI USA, V99, P14578 MILLER JH, 1972, EXPT MOL GENETICS MULLIGAN JT, 1985, P NATL ACAD SCI USA, V82, P6609 NAGEL R, 1990, FEMS MICROBIOL LETT, V67, P325 NAKAI K, 1998, PLANT BIOTECH, V15, P221 PETERS NK, 1986, SCIENCE, V233, P977 REDDY PM, 1997, PLANT SOIL, V194, P81 REDDY PM, 2000, NITROGEN FIXATION MO, P331 REDDY PM, 2000, QUEST NITROGEN FIXAT, P241 REDDY PM, 2002, NITROGEN FIXATION MI, P421 ROLFE BG, 2000, QUEST NITROGEN FIXAT, P291 SABLOWSKI RWM, 1994, EMBO J, V13, P128 SAMBROOK J, 1989, MOL CLONNING LAB MAN SIMINSZKY B, 1999, P NATL ACAD SCI USA, V96, P1750 SPAINK HP, 2000, ANNU REV MICROBIOL, V54, P257 SREEVIDYA VS, 2005, PLANT SCI, V169, P726 STEELE CL, 1999, ARCH BIOCHEM BIOPHYS, V367, P146 TAYLOR BH, 1993, METHODS PLANT MOL BI, P37 VINCENT JM, 1970, IPB HDB, V15 WINKELSHIRLEY B, 2001, PLANT PHYSIOL, V126, P485 YAMAGUCHI MA, 1999, PHYTOCHEMISTRY, V52, P15 YOSHIDA S, 1976, LAB MANUAL PHYSL STU, P61 YU O, 2000, PLANT PHYSIOL, V124, P781 NR 43 TC 1 PU OXFORD UNIV PRESS PI OXFORD PA GREAT CLARENDON ST, OXFORD OX2 6DP, ENGLAND SN 0022-0957 J9 J EXP BOT JI J. Exp. Bot. PD JUN PY 2006 VL 57 IS 9 BP 1957 EP 1969 PG 13 SC Plant Sciences GA 061XM UT ISI:000238907200012 ER PT J AU Moreno-Diaz, H Navarrete-Vazquez, G Estrada-Soto, S Tlahuext, H AF Moreno-Diaz, Hermenegilda Navarrete-Vazquez, Gabriel Estrada-Soto, Samuel Tlahuext, Hugo TI 2-(4-Methoxyphenyl)-1H-benzimidazole SO ACTA CRYSTALLOGRAPHICA SECTION E-STRUCTURE REPORTS ONLINE LA English DT Article AB In the title compound, C14H12N2O, the dihedral angle between the benzimidazole ring system and the 4-methoxyphenyl substituent is 34.12(6)degrees. The molecules are linked by intermolecular N-(HN)-N-... hydrogen bonds, forming chains running along the c axis. C1 Univ Autonoma Estado Morelos, Ctr Invest Quim, Cuernavaca, Morelos, Mexico. Univ Autonoma Estado Morelos, Fac Farm, Cuernavaca 62100, Morelos, Mexico. RP Tlahuext, H, Univ Autonoma Estado Morelos, Ctr Invest Quim, Ave Univ 1001 Col Chamilpa, Cuernavaca, Morelos, Mexico. EM tlahuext@ciq.uaem.mx CR ANDRZEJEWSKA M, 2002, EUR J MED CHEM, V37, P973 BALI A, 2005, BIOORG MED CHEM LETT, V15, P3962 BRUKER, 2000, SMART VERSION 5 618 KUCUKBAY H, 2003, FARMACO, V58, P431 NAVARRETEVAZQUEZ G, 2003, BIOORGAN MED CHEM, V11, P4615 OZDEN S, 2005, BIOORGAN MED CHEM, V13, P1587 SHELDRICK GM, 1990, ACTA CRYSTALLOGR A, V46, P467 SHELDRICK GM, 1997, SHELXL97 NR 8 TC 1 PU BLACKWELL PUBLISHING PI OXFORD PA 9600 GARSINGTON RD, OXFORD OX4 2DQ, OXON, ENGLAND SN 1600-5368 J9 ACTA CRYSTALLOGR E-STRUCT REP JI Acta Crystallogr. Sect. E.-Struct Rep. Online PD JUL PY 2006 VL 62 PN Part 7 BP O2601 EP O2602 PG 2 SC Crystallography GA 059KO UT ISI:000238731900129 ER PT J AU Perez-Vivar, TL Reyes-Bonilla, H Padilla, C TI Stony corals (Scleractinia) from the marias islands, Mexican pacific SO CIENCIAS MARINAS LA Spanish DT Article DE Marias Islands; Scleractinia; Mexican Pacific; coral reefs; biogeography ID EASTERN PACIFIC; EL-NINO; REEFS; GULF AB Recent studies performed off the Pacific coast of Mexico have shown a large number of reefs or coral patches in the region, but information is still lacking for some areas. One of these is the Marias Archipelago (21 degrees N), composed of four islands: Maria Madre, Maria Magdalena, Maria Cleofas and San Juanito. The objective of this paper was to make a general evaluation of the status of the corales in the archipelago by revising the systematic list of species and analyzing the community structure and biogeographic patterns of the fauna. Twenty-one locations at Maria Madre Island and two at San Juanito Island were visited in August 1997, and at each we conducted a video transect (150 m long) to describe zonation and a line transect (20 m long) for quantitative analyses. This information was complemented with literature reviews and data from specimens deposited in museums in Mexico and the United States. After obtaining the systematic list of corals from the islands, we compared the level of similarity of the fauna with that from five nearby regions (including the Revillagigedo Islands and the mainland from 23 degrees N to 18 degrees N), and ordination analyses were run. In the field we observed 13 species of stony corals (including eight new records), but did not find Porites baueri, a nominally endemic species from the Marias Islands. The museum revisions produced two new records. Thus, analyzing the full data set, 20 species are considered residents of the study area. There were no constructional reefs in the archipelago, but coral abundance was high, especially at Maria Madre Island. The communities showed a clear zonation, with Pocillopora in shallow water and Porites, Pavona and Psammocora in deeper localities. Finally, the biogeographic analysis indicated that the mouth of the Gulf of California represents a key area for species immigration from the western Pacific, and that the Marias Islands seem to act as a nodal point for coral dispersal to the north. C1 Univ Nacl Autonoma Mexico, Inst Ciencias Mar & Limnol, Mexico City, DF, Mexico. Univ Autonoma Baja California, Dept Biol Marina, La Paz, Baja California, Mexico. Inst Nacl Pesca, Ctr Reg Invest Pesqueras Puerto Morelos, Quintana Roo, Mexico. RP Perez-Vivar, TL, Univ Nacl Autonoma Mexico, Inst Ciencias Mar & Limnol, Apartado Postal 70-305,Ciudad Univ,CP 04510, Mexico City, DF, Mexico. EM hreyes@uabcs.mx CR *WOA, 2001, WORLD OC ATL CARRIQUIRY JD, 1997, CIENC MAR, V23, P227 CARRIQUIRY JD, 2001, B MAR SCI, V69, P237 CLARKE KR, 2001, CHANGE MARINE COMMUN CRISCI JV, 2003, HIST BIOGEOGRAPHY DURHAM JW, 1952, A HANCOCK PAC EXPED, V16, P1 ENGLISH S, 1997, SURVEY MANUAL TROPIC GARCIA E, 1989, CLIMAS GLYNN PW, 1997, REV BIOL TROP, V45, P1033 GLYNN PW, 2000, CORAL REEFS, V19, P1 GLYNN PW, 2000, P 9 INT COR REEF S B, V2, P1169 GUZMAN HM, 1993, REV BIOL TROP, V41, P535 GUZMAN ML, 1959, ISLAS MARIAS IGLESIASPRIETO R, 2004, P ROY SOC LOND B BIO, V271, P1757 KETCHUM JT, 2001, REV BIOL TROP, V49, P803 KNOWLTON N, 1993, ANNU REV ECOL SYST, V24, P189 QUINN GP, 2002, EXPT DESIGN DATA ANA REVUELTAS J, 1988, MUROS AGUA REYESBONILLA H, 1993, BIODIVERSIDAD MARINA, P207 REYESBONILLA H, 1998, CIENC MAR, V24, P211 REYESBONILLA H, 1999, REV BIOL TROP, V47, P273 REYESBONILLA H, 2002, CORAL REEFS, V21, P368 REYESBONILLA H, 2002, J NAT HIST, V36, P1 REYESBONILLA H, 2003, LATIN AM CORAL REEFS, P331 REYESBONILLA H, 2005, ATLAS CORALES PETREO ROBERTSON DR, 2002, SHOREFISHES TROPICAL SMALL M, 1998, FESTIVUS, V30, P75 SPALDING M, 2000, WORLD ATLAS CORAL RE SQUIRES DF, 1959, B AM MUS NAT HIST, V118, P367 VERON JEN, 1986, CORALS AUSTR INDOPAC VERON JEN, 2000, CORALS WORLD, V1 VIDALZEPEDA R, 1989, PRECIPITACION WELLINGTON GM, 1982, ECOL MONOGR, V52, P223 WELLS JW, 1983, CORALS CORAL REEFS G, P209 WELLS SM, 1988, CORAL REEFS WORLD, V1 NR 35 TC 0 PU INSTITUTO INVESTIGACIONES OCEANOLOGICAS, U A B C PI BAJA CALIFORNIA PA APARTADO POSTAL 423, ENSENADA, BAJA CALIFORNIA 22800, MEXICO SN 0185-3880 J9 CIENC MAR JI Ceinc. Mar. PD JUN PY 2006 VL 32 IS 2 BP 259 EP 270 PG 12 SC Marine & Freshwater Biology GA 056CG UT ISI:000238498100005 ER PT J AU Martinez, H Hernandez, CL Yousif, FB TI Absolute differential and total cross sections for charge transfer of O+ ground and mixed states ions in N-2 SO JOURNAL OF PHYSICS B-ATOMIC MOLECULAR AND OPTICAL PHYSICS LA English DT Article ID H-2-MOLECULES; COLLISIONS; MOLECULES; O&(D-2); H-2 AB We report measurements of the total and absolute differential cross sections for charge transfer of ground- and excited-states O+ ions at 1.0, 1.5, 2.0, 2.5, 3.0, 3.5, 4.0, 4.5 and 5 keV in collisions with N-2 at scattering angles - 5.2 degrees <= Theta <= 5.2 degrees in the laboratory frame. Total cross sections for groundand mixed state ions are compared with previous measurements. The behaviour of the absolute differential cross sections display an expected decreasing behaviour with increasing angle. The mixed state ions cross sections are considerably higher than those measured for the ground state ions. C1 Univ Nacl Autonoma Mexico, Ctr Ciencias Fis, Cuernavaca 62251, Morelos, Mexico. Univ Autonoma Estado Morelos, Fac Ciencias, Cuernavaca 62210, Morelos, Mexico. RP Martinez, H, Univ Nacl Autonoma Mexico, Ctr Ciencias Fis, POB 48-3, Cuernavaca 62251, Morelos, Mexico. EM fbyousif@servm.fc.uaem.mx CR FERGUSON EE, 1979, GAS PHASE ION CHEM FLESCH GD, 1990, J CHEM PHYS, V92, P3235 HOFFMAN JM, 1982, PHYS REV A, V25, P1930 IRVINE AD, 1991, J PHYS B ATOM MOL PH, V24, L145 ISHIMOTO M, 1986, J GEOPHYS RES, V91, P5783 LAVOLLEE M, 1989, J PHYS B ATOM MOL PH, V22, P2019 LI X, 1997, J CHEM PHYS, V106, P1373 LINDSAY BG, 1998, PHYS REV A, V57, P331 LUNA H, 2003, J GEOPHYS RES-PLANET, V108 MARTINEZ H, 2004, PHYS REV A, V69 MORAN TF, 1978, J CHEM PHYS, V69, P1397 MORAN TF, 1980, PHYS REV A, V21, P1051 RUTHERFORD JA, 1971, J CHEM PHYS, V55, P5622 STEBBINGS RF, 1966, J GEOPHYS RES, V71, P771 TURNER BR, 1968, J CHEM PHYS, V48, P1602 XU YD, 1990, J PHYS B ATOM MOL PH, V23, P1235 NR 16 TC 0 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0953-4075 J9 J PHYS-B-AT MOL OPT PHYS JI J. Phys. B-At. Mol. Opt. Phys. PD JUN 14 PY 2006 VL 39 IS 11 BP 2535 EP 2543 PG 9 SC Optics; Physics, Atomic, Molecular & Chemical GA 054LP UT ISI:000238378500021 ER PT J AU Gamboa, SA Gonzalez-Rodriguez, JG Valenzuela, E Campillo, B Sebastian, PJ Reyes-Rojas, A TI Evaluation of the corrosion resistance of Ni-Co-B coatings in simulated PEMFC environment SO ELECTROCHIMICA ACTA LA English DT Article DE Ni-Co-B coating; rietveld profile; PEMFC; bipolar plates; corrosion resistance ID TYPE-316 STAINLESS-STEEL; FUEL-CELL; BIPOLAR PLATES; ALLOY; HYDROGENATION AB The corrosion resistance behavior of Ni-Co-B coated carbon steel, Al 6061 alloy and 304 stainless steel was evaluated in simulated proton exchange membrane fuel cell (PEMFC) environment. The phase structure of the NiCoB based alloy was determined by Rietveld analysis. The PEMFC environment was constituted of 0.5 M H2SO4 at 60 degrees C and the evaluation techniques employed included potentiodynamic polarization, linear polarization resistance, open circuit potential measurements and electrochemical impedance spectroscopy. The results showed that in all cases the corrosion resistance of the Ni-Co-B coating was higher than that of the uncoated alloys; about two orders of magnitude with respect to carbon steel and an order of magnitude compared to 304 stainless steel. Except for the uncoated 304 type stainless steel, the polarization curves for the coated specimens did not exhibit a passive region but only anodic dissolution. The corrosion potential value, E-corr, was always nobler for the coated samples than for the uncoated specimens. This was true for the stainless steel in the passive region, but in the active state for the carbon steel and Al 6061 alloy. The corrosion of the underlying alloy occurred due to filtering of the solution through coating defects like microcracks, pinholes, etc. During the filtering process the E-corr value of the coating decreased slowly until it reached a steady state value, close to the E-corr value of the underlying alloy. (c) 2005 Elsevier Ltd. All rights reserved. C1 UNAM, CIE, Temixco 62580, Morelos, Mexico. UAEM, CIICAp, Cuernavaca 62210, Morelos, Mexico. UNAM, Fac Quim, Mexico City 04510, DF, Mexico. UNAM, CCF, Cuernavaca 62210, Morelos, Mexico. Univ Politecn Chiapas, Tuxtla Gutierrez 29082, Chiapas, Mexico. CIMAV, Chihuahua 31109, Chih, Mexico. RP Gamboa, SA, UNAM, CIE, Temixco 62580, Morelos, Mexico. EM sags@cie.unam.mx CR *DEP COMM US AM NA, 1989, 674A DEP COMM US AM CABALLERO LX, 1995, 5413804, US CAMPILLO B, 2002, MAT SCI ENG C-BIO S, V19, P115 DENG JF, 1999, CATAL TODAY, V51, P113 HERNAS AA, 1999, CORROS SCI, V41, P2251 LEE SJ, 2003, J MATER PROCESS TECH, V140, P688 LI MC, 2003, ELECTROCHIM ACTA, V48, P1735 LI MC, 2004, CORROS SCI, V46, P1369 LUO HS, 2001, CHEM LETT 0505, P404 NARAYANAN TSNS, 2004, SURF COAT TECH, V179, P56 ONODA M, 1993, J MAGN MAGN MATER, V126, P595 POZIO A, 2003, ELECTROCHIM ACTA, V48, P1543 RODRIGUEZCARVAJ.J, 1998, PROGRAM FULLPROF98 V ROJAS AR, 2005, J PHYS D APPL PHYS, V38, P2276 SAITO T, 1998, J APPL ELECTROCHEM, V28, P559 STEARN M, 1958, J ELECTROCHEM SOC, V105, P638 UEDA M, 2004, INTERMETALLICS, V12, P55 WANG H, 1995, APPL CATAL A-GEN, V129, P143 WANG H, 2004, J POWER SOURCES, V138, P86 YU ZB, 1997, APPL CATAL A-GEN, V163, P1 NR 20 TC 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0013-4686 J9 ELECTROCHIM ACTA JI Electrochim. Acta PD MAY 20 PY 2006 VL 51 IS 19 BP 4045 EP 4051 PG 7 SC Electrochemistry GA 051AR UT ISI:000238133200023 ER PT J AU Bindu, K Nair, MTS Nair, PK TI Chemically deposited se thin films and their use as a planar source of selenium for the formation of metal selenide layers SO JOURNAL OF THE ELECTROCHEMICAL SOCIETY LA English DT Article ID BATH DEPOSITION; AQUEOUS-SOLUTIONS; PRECURSOR; SILVER AB Selenium thin films of thickness similar to 300 nm were deposited from a solution of sodium selenosulfate of pH 4.5. These films are amorphous, but they are crystalline and photoconductive through annealing for 15 min at 150-200 degrees C. In this paper we present the properties of these films and their use as a planar source of selenium vapor (1.7 x 10(-6) mol/cm(2) of the film) to react with metal films to form metal selenide layers. For this, metal films of Ag, Sn, In, Cu, Sb, etc., deposited by thermal evaporation, are kept in contact with the Se-thin film and are heated at temperatures typically < 350 degrees C in nitrogen. This process leads to the formation of thin films of Ag2Se, SnSe2, In2Se3, CuSe/Cu2-xSe, Sb2Se3, etc. Se-metal reaction also takes place under microwave heating. In the case of an evaporated Ag film on a chemically deposited thin film of Sb2S3, AgSbSe2 is produced through heating at 200-300 degrees C. Photovoltaic structures SnO2: F-CdS-Sb2S3-AgSbSe2 fabricated this way show open-circuit voltage > 500 mV and short-circuit current density of 2-5 mA/cm(2). (c) 2006 The Electrochemical Society. C1 Univ Nacl Autonoma Mexico, Ctr Invest Energia, Dept Solar Energy Mat, Temixco 62580, Morelos, Mexico. RP Bindu, K, Univ Nacl Autonoma Mexico, Ctr Invest Energia, Dept Solar Energy Mat, Temixco 62580, Morelos, Mexico. EM mtsn@cie.unam.mx CR ARENAS OL, 1997, SEMICOND SCI TECH, V12, P1323 BHATTACHARYA RN, 1997, J ELECTROCHEM SOC, V144, P1376 BINDU K, 2002, APPL SURF SCI, V191, P138 BINDU K, 2002, SEMICOND SCI TECH, V17, P270 BINDU K, 2003, SOL ENERG MAT SOL C, V79, P67 BINDU K, 2004, SEMICOND SCI TECH, V19, P1348 BINDU K, 2005, SEMICOND SCI TECH, V20, P496 CHEN RZ, 2002, J MATER CHEM, V12, P1437 CULLITY BD, 2001, ELEMENTS XRAY DIFFRA FOFANOV GM, 1969, RUSS J INORG CHEM, V14, P322 GARCIA VM, 1999, J CRYST GROWTH, V203, P113 GROZDANOV I, 1994, SYNTHETIC MET, V63, P213 GUPTA A, 1998, SOL ENERG MAT SOL C, V53, P385 HODES G, 2003, CHEM SOLUTOIN DEPOSI HOUMES JD, 1997, J SOLID STATE CHEM, V130, P266 HSU HH, 2003, J ELECTROCHEM SOC, V150, C813 IBRAGIMOV NI, 2000, THIN SOLID FILMS, V359, P125 KAPUR VK, 2001, MAT RES SOC S P, V668 KAPUR VK, 2003, THIN SOLID FILMS, V431, P53 KITAEV GA, 1970, RUSS J INORG CHEM, V15, P167 KITAEV GA, 1970, ZH PRIKL KHIM, V43, P169 MADELUNG O, 1992, SEMICONDUCTORS OTHER, P72 MANE RS, 2000, MATER CHEM PHYS, V65, P1 MANOHARAN SS, 2001, PHYS REV B, V63 NAIR MTS, 1994, J APPL PHYS, V75, P1557 NAIR MTS, 1998, J ELECTROCHEM SOC, V145, P2113 NIESEN TP, 2001, J ELECTROCERAM, V6, P169 PEDERSON LR, 1982, SOL ENERG MATER, V6, P221 PEJOVA B, 2001, APPL SURF SCI, V177, P152 RAMANATHAN K, 2005, THIN SOLID FILMS, V480, P499 RODRIGUEZLAZCANO Y, 2005, THIN SOLID FILMS, V493, P77 SAMPATH PI, 1966, J CHEM PHYS, V45, P3519 SUAREZSANDOVAL DY, 2006, J ELECTROCHEM SOC, V153, C91 VOSSEN JL, 1978, THIN FILM PROCESSES, P210 WADA T, 2003, THIN SOLID FILMS, V431, P11 ZINGARO RA, 1953, J ORG CHEM, V18, P292 NR 36 TC 1 PU ELECTROCHEMICAL SOC INC PI PENNINGTON PA 65 SOUTH MAIN STREET, PENNINGTON, NJ 08534 USA SN 0013-4651 J9 J ELECTROCHEM SOC JI J. Electrochem. Soc. PY 2006 VL 153 IS 7 BP C526 EP C534 PG 9 SC Electrochemistry; Materials Science, Coatings & Films GA 048KF UT ISI:000237945300044 ER PT J AU Natividad, C Salazar, M Contreras, A Albiter, A Perez, R Gonzalez-Rodriguez, JG TI Sulfide stress cracking susceptibility of welded X-60 and X-65 pipeline steels SO CORROSION LA English DT Article DE hydrogen embrittlement; sulfide stress corrosion cracking; X-60 and X-65 steel weldments AB The susceptibility of API X-60 and X-65 longitudinal weld beads to sulfide stress cracking (SSC) has been evaluated using slow strain rate tests (SSRT) in the NACE solution saturated with hydrogen sulfide (H2S). The tests were supplemented by potentiodynamic polarization curves and hydrogen permeation measurements. The weld beads were produced using the submerged arc welding (SAM) process. Three different temperatures were used: room temperature (25 degrees C), 37 degrees C, and 50 degrees C. The corrosion rate, taken as the corrosion current density, I-corr, the amount of hydrogen uptake for the weldments, C-0, and the SSC susceptibility increased with an increase in the temperature from 25 degrees C to 50 degrees C. Although anodic dissolution seems to play an important role in the cracking mechanism, the most likely mechanism for the cracking susceptibility of X-60 and X-65 weldments in H2S solutions seems to be hydrogen embrittlement. C1 UAEM, CIICAP, Cuernavaca 6225, Morelos, Mexico. Univ Nacl Autonoma Mexico, Fac Quim Circuito Interior, CU, Mexico City 04510, DF, Mexico. Inst Mexicano Petr, Programa Invest & Desarrollo Ductos, Mexico City 07730, DF, Mexico. RP Gonzalez-Rodriguez, JG, UAEM, CIICAP, Av Univ 1001,Col Chamilpa, Cuernavaca 6225, Morelos, Mexico. EM ggonzalez@uaem.mx CR *ASTM, 1999, ANN BOOK ASTM STAND *NACE, 2005, MR0175 NACE, P1 *NACE, 2005, TM0177 NACE ASAHI H, 1994, CORROSION, V50, P537 BHATTI AR, 1984, WELD J, V63, P224 CHARBONNIER JC, 1988, REV METAL, V1, P91 DAWSON JL, 1999, EUROPEAN FEDERATION, V6, P155 DEVANATHAN MAV, 1962, P ROY SOC LOND A MAT, V270, P90 DOLBY RE, 1976, 141976M WELD I MEMB ECHANIZ G, 1999, EUROPEAN FEDERATION, V6, P135 GINGELL A, 1999, EUROPEAN FEDERATION, V6, P127 GRIFFITHS AJ, 1997, CORROSION, V53, P700 KIRKWOOD PR, 1978, MET CONSTR, V5, P260 LIOU HY, 2002, CORROS SCI, V44, P2841 NR 14 TC 0 PU NATL ASSN CORROSION ENG PI HOUSTON PA 1440 SOUTH CREEK DRIVE, HOUSTON, TX 77084-4906 USA SN 0010-9312 J9 CORROSION JI Corrosion PD MAY PY 2006 VL 62 IS 5 BP 375 EP 382 PG 8 SC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering GA 046VY UT ISI:000237840400002 ER PT J AU Salinas-Bravo, VM Porcayo-Calderon, J Gonzalez-Rodriguez, JG TI Corrosion monitoring using electrochemical noise and linear polarization resistance in fuel oil combustion gas environment SO RUSSIAN JOURNAL OF ELECTROCHEMISTRY LA English DT Article DE online corrosion monitoring; electrochemical noise; linear polarization; high-temperature corrosion; fuel oil ashes ID FIRED BOILERS AB Corrosion monitoring of different steels is carried out online in a combustion rig firing 32 kg/h of fuel oil. Two temperature-control led probes are designed to allow control of the specimens temperature and the use of electrochemical noise (EN) and linear polarization resistance (LPR) techniques for corrosion monitoring Two probes are placed where the combustion gas reached a temperature of 850-900 degrees C, and another one at the combustion gas exit where the rig was at 200-240 degrees C. Corrosion rates of an austenitic and a ferritic steel are obtained where the temperature of the combustion gas is 850-900 degrees C, firing fuel oils with different content of Na-V-S. Corrosion monitoring of mild steel is carried out in the test burning a fuel oil with the higher content of Na-V-S by placing a corrosion probe in the low combustion gas temperature zone. The EN results show that this technique is able to assess the corrosion rate in an environment at high temperature where fuel oil ashes deposited and at a temperature high enough where they start to melt and a corrosion process proceeds. Results show that this technique is able to assess the corrosivity of fuel oil ashes originated from fuel oil containing different amounts of sodium, vanadium, and sulfur as corrosion causing impurities. Results of the low-temperature probe show that EN and LPR are able to detect the onset of corrosion on mild steel as a result of sulfuric acid condensation on the probe. However, the corrosion rates are not the same, because localized corrosion is taking place as detected by the EN technique. It is demonstrated that the use of two techniques for corrosion monitoring can give a better understanding of the corrosion process. Electrochemical techniques used to assess the corrosion resistance of alloys at high and low temperatures prove to be a valuable tool for the purposes of materials selection or controlling the main process variables that affect the corrosion resistance of materials in industrial equipment. C1 Inst Invest Elect, Cuernavaca 62490, Morelos, Mexico. UAEM, CIICAp, Cuernavaca 62210, Morelos, Mexico. RP Salinas-Bravo, VM, Inst Invest Elect, Av Reforma 113 Col Palmira, Cuernavaca 62490, Morelos, Mexico. EM vsalinas@iie.org.mx CR 1978, IND CORROSION MONITO CALLOW LM, 1976, BR CORROS J, V11, P123 COATS AW, 1969, J I FUEL, V42, P75 DAVIS K, 2000, P 25 INT C COAL UT F, P25 DEMO JJ, 1978, CORROSION ELLIOT P, 1973, J I FUEL, V46, P35 FARREL DM, 1987, SOLVING CORROSION PR FARRELL DM, 1989, MAT SCI ENG GITANJALY PS, 2002, BR CORROS J, V37, P56 HARADA Y, 1984, P 2 INT C FUT HEAV C, P2 HARB JN, 1990, PROG ENERG COMBUST, V16, P169 HLADKY K, 1985, UK CORROSION JASKE CE, 2002, CORROS PREVENT CONTR, V49, P3 KANE RD, 1999, CHEM ENG PROG, V94, P49 KAWAMURA T, 1980, MITSUBISHI TECH B LINJEWILE TM, 2003, MATER HIGH TEMP, V20, P175 PAUL LD, 1990, CORROSION SCRIVASTAVA SC, 1997, J MATER SCI, V32, P835 WHITLOW GA, 1991, CORROSION NR 19 TC 1 PU MAIK NAUKA/INTERPERIODICA/SPRINGER PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013-1578 USA SN 1023-1935 J9 RUSSIAN J ELECTROCHEMISTRY JI Russ. J. Electrochem. PD MAY PY 2006 VL 42 IS 5 BP 560 EP 565 PG 6 SC Electrochemistry GA 045VY UT ISI:000237772000015 ER PT J AU Xaman, J Alvarez, G TI Effect of heat conduction of SnS-CuXS solar control coated semitransparent wall on turbulent natural convection in a square cavity SO NUMERICAL HEAT TRANSFER PART A-APPLICATIONS LA English DT Article ID COMPARISON EXERCISE; RADIATION; PERFORMANCE; ENCLOSURES; TRANSIENT; LAMINAR; FLUID; FLOWS AB Interaction effects of semitransparent glazing with SnS-CuxS solar control coating on the turbulent natural convection in a square cavity containing air is analyzed numerically. The size of the cavity covers a range from 0.70 to 6.98m ( Ra = 10(9)-10(12)). One vertical wall of the cavity is isothermal, and the opposite one is the semitransparent glazing. Top and bottom walls are adiabatic. The 2-D mass, momentum, and energy equations using the turbulent k-epsilon model are solved by the finite-volume technique. The model is verified, reducing the problem to a differentially heated square cavity and indicating very good agreement. The isotherms, turbulent viscosity distributions, temperatures of the interior and exterior surfaces of the glazing with solar control coating ( SCCG) and without solar control coating ( WSCCG) for the 6.98-m cavity are presented. The average semitransparent wall temperatures were 64 degrees C for SCCG and 40 degrees C for WSCCG. The Nusselt numbers for SCCG and WSCCG versus the length of the cavity show that the difference is a range of 17% to 22%. Correlations for the average Nusselt numbers for steady state are presented for 0.70m <= W <= 6.98m and Pr = 0.71. The solar heat gain coefficient SHGC indicates that for the glazing with SnS-CuxS solar control coating, the energy gain toward the interior decreases by 48.8%. C1 CENIDET, Dept Mech Engn, Thermal Syst Area, Cuernavaca 62490, Morelos, Mexico. RP Alvarez, G, CENIDET, Dept Ingn Mecan Term, Prol Av Palmira S-N Col Palmira, Cuernavaca 62490, Morelos, Mexico. EM gaby@cenidet.edu.mx CR *ASHRAE, 2002, ASHRAE FUND ALVAREZ G, 2000, INT J NUMER METH FL, V34, P585 BEHNIA M, 1990, INT J NUMER METH FL, V10, P305 DAVIS GD, 1983, INT J NUMER METH FL, V3, P227 GRIMMER DP, 1979, SOL ENERGY, V22, P351 HENKES R, 1990, THESIS DELFT U TECHN HENKES RAWM, 1991, INT J HEAT MASS TRAN, V34, P377 HENKES RAWM, 1995, NUMER HEAT TR B-FUND, V28, P59 HINOJOSA JF, 2005, NUMER HEAT TR A-APPL, V48, P179 KWON SS, 1993, 6 INT S TRANSP PHEN, P299 MALLINSON GD, 1973, J COMPUT PHYS, V12, P435 MARCONDES F, 2001, NUMER HEAT TR A-APPL, V40, P403 MARKATOS NC, 1984, INT J HEAT MASS TRAN, V27, P755 MODEST M, 1993, RAD HEAT HEAT TRANSF MOHAMED B, 1998, THESIS CAIRO U CAIRO NAIR MTS, 1991, J PHYS D APPL PHYS, V24, P450 PATANKAR S, 1980, NUMERICAL HEAT TRANS PEREZSEGARRA CD, 1995, INT J NUMER METHOD H, V5, P13 POPE S, 2000, TURBULENT FLOWS RAMEY M, 1998, THESIS OKLAHOMA STAT RIDOUANE EH, 2004, NUMER HEAT TR A-APPL, V45, P289 SHAVIV E, 1984, ENERG BUILDINGS, V7, P315 STRAW M, 2000, THESIS NOTTINGHAM U VANDOORMAAL JP, 1984, NUMER HEAT TRANSFER, V7, P147 VELUSAMY K, 2001, J HEAT TRANS-T ASME, V123, P1062 XAMAN J, 2005, ENERG BUILDINGS, V37, P787 NR 26 TC 1 PU TAYLOR & FRANCIS INC PI PHILADELPHIA PA 325 CHESTNUT ST, SUITE 800, PHILADELPHIA, PA 19106 USA SN 1040-7782 J9 NUMER HEAT TRANSFER PT A-APPL JI Numer. Heat Tranf. A-Appl. PD JUL 1 PY 2006 VL 50 IS 1 BP 79 EP 98 PG 20 SC Thermodynamics; Mechanics GA 042ST UT ISI:000237550500005 ER PT J AU Islas-Hernandez, JJ Rendon-Villalobos, R Agama-Acevedo, E Gutierrez-Meraz, F Tovar, J Arambula-Villa, G Bello-Perez, LA TI In vitro digestion rate and resistant starch content of tortillas stored at two different temperatures SO LWT-FOOD SCIENCE AND TECHNOLOGY LA English DT Article DE tortilla; storage; resistant starch; digestion rate; digestibility ID WAXY MAIZE; STORAGE; RETROGRADATION; GELATINIZATION; DIGESTIBILITY; AMYLOPECTIN; FOODS; GELS AB In vitro indicators of starch bioavailability were evaluated in freshly prepared maize tortillas and compared to those exhibited by 24, 48 or 72 h-stored samples. Storage took place either at room temperature (approx. 25 degrees C) or under refrigeration (4 degrees C). Potentially available starch (AS) content decreased from 670 g kg(-1) in the control tortilla to 583 g kg(-1) in 72 h-stored preparations. Concomitant increases in total resistant starch (RS) and retrograded resistant starch (RRS) were recorded upon storage. RRS content in 72h-stored samples (35-39g kg(-1)) doubled that of freshly prepared tortillas. Changes in AS, RS and RRS were not affected by storage temperature. Both initial rate and final point of starch hydrolysis by pancreatic amylase were reduced in samples kept for 48 and 72h, without influence of storage temperature. Storage length is suggested as a major determinant of the bioavailability of starch in tortillas. (c) 2005 Swiss Society of Food Science and Technology. Published by Elsevier Ltd. All rights reserved. C1 IPN, Ctr Desarrollo Prod Bioticos, Yautepec 62731, Morelos, Mexico. Cent Univ Venezuela, Fac Ciencias, Inst Expt Biol, Caracas 1041A, Venezuela. IPN, Unidad Queretato, Ctr Invest & Estudios Avanzados, Real De Juriquilla 76230, Queretaro, Mexico. RP Bello-Perez, LA, IPN, Ctr Desarrollo Prod Bioticos, Apartado Postal 24 CP, Yautepec 62731, Morelos, Mexico. EM labellop@ipn.mx CR AGAMAACEVEDO E, 2004, NAHRUNG, V48, P38 ASP NG, 1992, EUR J CLIN NUTR S2, V46, S1 BJORCK I, 1994, AM J CLIN NUTR, V59, S699 CAMPASBAYPOLI ON, 2002, STARCH-STARKE, V54, P358 CAMPUSBAYPOLI ON, 1999, STARCH-STARKE, V51, P173 ENGLYST HN, 1992, EUR J CLIN NUTR S2, V46, P33 FARHAT IA, 2000, BIOPOLYMERS, V53, P411 FERRAN M, 1996, SPSS WINDOWS PROGRAM FREDRIKSSON H, 2000, CARBOHYD POLYM, V43, P81 FRENCH D, 1984, ORG STARCH GRANULES, P183 GARCIAALONSO A, 1999, FOOD CHEM, V66, P181 GONI I, 1996, FOOD CHEM, V56, P445 HOLM J, 1985, J CEREAL SCI, V3, P193 HOLM J, 1986, STARCH-STARKE, V38, P224 PAREDESLOPEZ O, 1994, FOOD CHEM, V50, P411 RENDONVILLALOBOS R, 2002, CEREAL CHEM, V79, P340 SAURACALIXTO F, 1993, J FOOD SCI, V58, P642 THEBAUDIN JY, 1998, FOOD SCI TECHNOL-LEB, V31, P354 THYGESEN LG, 2003, STARCH-STARKE, V55, P241 TOVAR J, 2001, METODOS DETERMINACIO, P143 TOVAR J, 2002, FOOD CHEM, V76, P455 TOVAR J, 2003, CEREAL CHEM, V80, P533 YAU JC, 1994, CEREAL FOOD WORLD, V39, P396 ZELEZNAK KJ, 1987, CEREAL CHEM, V64, P121 NR 24 TC 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0023-6438 J9 LWT-FOOD SCI TECHNOL JI LWT-Food Sci. Technol. PY 2006 VL 39 IS 8 BP 947 EP 951 PG 5 SC Food Science & Technology GA 044KQ UT ISI:000237671600013 ER PT J AU Aparicio-Saguilan, A Mendez-Montealvo, G Solorza-Feria, J Bello-Perez, LA TI Thermal and viscoelastic properties of starch gels from maize varieties SO JOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE LA English DT Article DE maize starch; calorimetry; functional properties; viscoelasticity ID GELATINIZATION; BEHAVIOR; RETROGRADATION; AMYLOPECTIN; WHEAT AB The aim of this work was to determine the thermal, functional and rheological properties of maize (Zea mays) starch isolated from seven varieties. Chemical analysis was undertaken in all starch samples. The gelatinization and retrogradation temperature at different storage times, as well as the enthalpy of the isolated starches, were determined using differential scanning calorimetry (DSC). Swelling and solubility were also measured in individual samples. Dynamic oscillatory tests (amplitude and frequency sweeps) were undertaken on starch samples with 10% (w/v) of total solids during a cycle of three stages (kinetics) of heating/cooling, using a strain-controlled rheometer. The samples presented an amylose content which ranged from 22% to 29%, typical in normal starches, the lipid values were under 1%, while the protein contents were just over 1%. The calorimetric profile for the studied starches showed a peak temperature (gelatinization) over the temperature range from 72.5 to 75.7 degrees C and enthalpy values between 13.68 and 17.58 Jg(-1). Four starches presented enthalpy values of the retrogradation transition that increased with the storage time, showing differences among the starches analysed. Maximum swelling and solubility were usually found at the second stage of the above-mentioned cycle. The rheological profile showed that the gels formed during the first stage of the above-mentioned kinetics presented the behaviour of weak viscoelastic gels with the storage or elastic modulus (G) higher than the loss or viscous modulus (G") over the applied strain and frequency ranges. All samples showed a more elastic character as the kinetics progressed. Starches isolated from diverse maize varieties showed differences in their characteristics studied, and might produce different functional properties in the products where they are used. (c) 2006 Society of Chemical Industry. C1 IPN, Ctr Desarrollo Prod Biot, Yautepec 62731, Morelos, Mexico. RP Solorza-Feria, J, IPN, Ctr Desarrollo Prod Biot, 8-5 Carr,Yautepec Jojulta Col San Isidro Apartado, Yautepec 62731, Morelos, Mexico. EM jsolorza@ipn.mx CR 1995, MINITAB WINDOWS USER ADKINS GK, 1966, STARCH-STARKE, V18, P213 BILIADERIS CG, 1991, CAN J PHYSIOL PHARM, V69, P60 BILIADERIS CG, 1992, FOOD TECHNOL-CHICAGO, V46, P98 BURCHARD W, 1993, PLANT POLYM CARBOHYD, P215 CHAMP M, 2003, NUTR RES REV, V16, P143 COOKE D, 1992, CARBOHYD RES, V227, P103 CZUCHAJOWSKA Z, 1993, CEREAL CHEM, V70, P701 DOUBLIER JL, 1989, CARBOHYD RES, V193, P215 DUBOIS M, 1956, ANAL CHEM, V28, P350 ELIASSON AC, 1986, J TEXTURE STUD, V17, P253 FERRY JD, 1980, VISCOELASTIC PROPERT GILBERT GA, 1964, METHODS CARBOHYDRATE, V4, P168 GONZALEZREYES E, 2003, CARBOHYD POLYM, V52, P297 HIZUKURI S, 1986, CARBOHYD RES, V147, P342 JIANGSU YQ, 1997, STARCH-STARKE, V49, P458 LANGE RHM, 1987, INTRO BOTANICA AGR, P18 LII CY, 1995, CEREAL CHEM, V72, P393 LINEBACK DR, 1984, BAKERS DIGEST 0316 LUALLEN TE, 1988, CEREAL FOODS WORLD, V33, P924 MACALLISTER RV, 1979, ADV CARBOHYD CHEM, P15 MOORE BO, 1985, STARCH CHEM TECHNOLO, P575 MORELL MK, 2005, CURR OPIN PLANT BIOL, V8, P204 PAREDESLOPEZ O, 1994, FOOD CHEM, V50, P411 SHI YC, 1992, CARBOHYD RES, V227, P133 TECANTE A, 1999, CARBOHYD POLYM, V40, P221 THOMAS DJ, 1999, STARCHES HDB SERIES TREJOGONZALEZ A, 1982, MODIFICATION PROTEIN, V198, P245 WALPOLE ER, 1999, PROBABILIDAD ESTADIS WANG LZ, 1994, CEREAL CHEM, V71, P451 WHISTLER RL, 1985, FOOD CHEM, P69 YUAN RC, 1993, CEREAL CHEM, V70, P81 NR 32 TC 0 PU JOHN WILEY & SONS LTD PI CHICHESTER PA THE ATRIUM, SOUTHERN GATE, CHICHESTER PO19 8SQ, W SUSSEX, ENGLAND SN 0022-5142 J9 J SCI FOOD AGR JI J. Sci. Food Agric. PD MAY PY 2006 VL 86 IS 7 BP 1078 EP 1086 PG 9 SC Agriculture, Multidisciplinary; Chemistry, Applied; Food Science & Technology GA 042LB UT ISI:000237528400008 ER PT J AU Mathew, X Hays, J Mejia-Garcia, C Contreras-Puente, G Punnoose, A TI Effect of annealing conditions on the Fe incorporation and ferromagnetism of Sn1-xFexO2: A Raman spectroscopic investigation SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID ROOM-TEMPERATURE FERROMAGNETISM; MAGNETIC-PROPERTIES; LATTICE-DYNAMICS; RUTILE STRUCTURE; THIN-FILMS; SNO2; OXIDES AB In order to investigate the effect of annealing conditions on the structural and magnetic properties, we have employed detailed Raman spectroscopic investigations on 5% Fe-doped SnO2 samples annealed at different temperatures in the range 200-900 degrees C. Systematic changes observed in the Raman spectra with increasing annealing temperature are correlated with similar changes in the structural and magnetic properties of these samples. The presence of incorporated Fe ions was confirmed from the appearance of vibrational local modes of Fe in the Raman spectra. It is concluded that the ferromagnetism in Sn0.95Fe0.05O2 annealed in the 350-600 degrees C temperature range is due to the incorporated Fe ions and is destroyed completely when TA>600 degrees C due to the expulsion of Fe from the SnO2 lattice, which is in agreement with the disappearance of the Fe local modes in the Raman spectra. (C) 2006 American Institute of Physics. C1 UNAM, CIE, Temixco 62580, Morelos, Mexico. Boise State Univ, Dept Phys, Boise, ID 83725 USA. IPN, Escuela Super Fis & Matemat, Mexico City 07738, DF, Mexico. RP Mathew, X, UNAM, CIE, Temixco 62580, Morelos, Mexico. EM xm@cie.unam.mx apunnoos@boisestate.edu CR ABELLO L, 1998, J SOLID STATE CHEM, V135, P78 BILZ H, 1979, PHONON DISPERSION RE, P135 BRYAN JD, 2004, J AM CHEM SOC, V126, P11640 COEY JMD, 2004, APPL PHYS LETT, V84, P1332 DAVIS SR, 1997, J PHYS CHEM B, V101, P9901 FOUCHET A, 2004, J APPL PHYS 2, V95, P7187 GERVAIS F, 1985, PHYS REV B, V31, P4809 KATIYAR RS, 1971, J PHYS C SOLID STATE, V4, P2421 MATSUMOTO Y, 2001, SCIENCE, V291, P854 OGALE SB, 2003, PHYS REV LETT, V91 PUNNOOSE A, 2004, APPL PHYS LETT, V85, P1559 PUNNOOSE A, 2005, PHYS REV B, V72 RISBUD AS, 2003, PHYS REV B, V68 YAN SS, 2004, APPL PHYS LETT, V84, P2376 YANG SG, 2002, IEEE T MAGN 1, V38, P2877 ZBORIL R, 2002, CHEM MATER, V14, P969 ZYSLER D, 2003, PHYS REV B, V68 NR 17 TC 3 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD APR 15 PY 2006 VL 99 IS 8 AR 08M101 DI ARTN 08M101 PG 3 SC Physics, Applied GA 040TV UT ISI:000237404200510 ER PT S AU Molina, A Campillo, B Mendoza, R Guardian, R Gonzalez, C Juarez-Islas, J TI Mechanical properties of ultra clean low C/Cr stabilized annealed sheets SO ADVANCED STRUCTURAL MATERIALS II SE MATERIALS SCIENCE FORUM LA English DT Article DE ultra low carbon steel; Cr stabilized; rolling; annealing; recrystallization texture; mechanical properties ID HSLA STEELS; IF-STEEL; PRECIPITATION; RECRYSTALLIZATION; BEHAVIOR; NIOBIUM AB The microstructural and mechanical properties of an ultra-clean low carbon steel sheet with 0.035% Cr have been evaluated. The isothermal recrystallization kinetics at 800 degrees C is analyzed by using the Kolomogorov-Johnson-Mehl-Avrami (KJMA) equation. The obtained results indicate that Cr retards the recrystallization kinetics owing to the presence of fine particles of chromium carbides. The annealing process produces a fully recrystallized microstructure. The main texture components in the specimens are: {111} < 112 >, {112} < 110 > and {111} < 110 >. These are related with the Lankford value and the elongation. The obtained results suggest that the formability of this steel is excellent. C1 UNAM, Inst Invest Mat, Mexico City, DF, Mexico. Ispat Mexicana SA CV, Michoacan, Mexico. UNAM, Fac Quim, Mexico City, DF, Mexico. UNAM, Ctr Ciencias Fis, Morelos, Mexico. UAEM, Fac Ciencias Quim & Ingn, Cuernavaca, Morelos, Mexico. RP Molina, A, UNAM, Inst Invest Mat, Mexico City, DF, Mexico. CR BLECK W, 1990, INTERSTITIAL FREE ST, P73 CUDDY LJ, 1981, METALL T A, V12, P1313 CUNDY LJ, 1982, THERMOMECHANICAL PRO, P613 GUPTA I, 1990, METALLURGY VACUUM DE, P57 HANSEN SS, 1980, METALLURG T A, V11, P387 HASHIMOTO N, 1998, ISIJ INT, V38, P617 HUA M, 1997, METALL MATER TRANS A, V28, P1769 HUA MJ, 1993, SCRIPTA METALL MATER, V28, P973 HUTCHINSON WB, 1990, METALLURGY VACUUM DE, P109 KCKAWA YH, 1997, ACTA MAT, V45, P3271 MENDOZA R, 1997, ISIJ INT, V37, P176 MENDOZA R, 2000, J MATER PROCESS TECH, V101, P238 MENDOZA R, 2003, SCRIPTA MATER, V48, P391 MORRISON WB, 1995, IRONMAK STEELMAK, V22, P453 MORRISON WB, 2000, HSLA STEELS 2000, P11 RAINFORTH WM, 2002, ACTA MATER, V50, P735 SAMAJDAR I, 1997, SCRIPTA MATER, V37, P869 TAKECHI H, 1988, TSETSU TO HAGANE, V74, P1617 TAKECHI H, 1994, ISIJ INT, V34, P1 WEISS I, 1980, METALL T A, V11, P403 WILSHYNSKYDRESL.O, 1994, INT S PHYS MET IF ST, P13 NR 21 TC 0 PU TRANS TECH PUBLICATIONS LTD PI ZURICH-UETIKON PA BRANDRAIN 6, CH-8707 ZURICH-UETIKON, SWITZERLAND SN 0255-5476 J9 MATER SCI FORUM PY 2006 VL 509 BP 31 EP 36 PG 6 SC Materials Science, Multidisciplinary GA BEF46 UT ISI:000237089800005 ER PT J AU Verma, SP Pandarinath, K Santoyo, E Gonzalez-Partida, E Torres-Alvarado, IS Tello-Hinojosa, E TI Fluid chemistry and temperatures prior to exploitation at the Las Tres Virgenes geothermal field, Mexico SO GEOTHERMICS LA English DT Article DE hydrogeochemistry; fluid inclusions; static formation temperatures; geothermometers; seawater component; heat balance; Baja California; Mexico ID BAJA-CALIFORNIA-SUR; HYDROTHERMAL SYSTEM; OUTLIER DETECTION; COMPUTER-PROGRAM; EVOLUTION; PRESSURE; MODELS; SILICA; ENERGY; WATER AB Generation of electricity at the Las Tres Virgenes (LTV) geothermal field, Mexico, began in 2001. There are currently nine geothermal wells in the field, which has an installed electricity generating capacity of 10 MW,. The chemical and temperature conditions prevailing in the field prior to its exploitation have been estimated, including their central tendency and dispersion parameters. These conditions were computed on the basis of: (i) geochemical data on waters from springs and domestic wells, and on geothermal well fluids (waters and gases); most of the sampling took place between 1995 and 1999; (ii) fluid inclusion studies; (iii) geothermometric data; and (iv) static formation temperatures computed using a modified quadratic regression Horner method. Fluid inclusion homogenization temperatures (in the 100-290 degrees C range) suggest that there is a high-temperature fluid upflow zone near wells LV3 and LV4 in the southern part of the field. Computed average chemical equilibrium temperatures for the geothermal fluids are similar to 260 degrees C, based on the Na/K and SiO2 geothermometers, and similar to 265 degrees C, based on the H-2/Ar, and CO2/Ar geothermometers. In general, the fluid inclusion homogenization temperatures are consistent with geothermometric data, as well as with static fort-nation temperatures. Some of the observed differences could be related to well interference effects and different fluid production/sampling depths. The deeper geothermal waters show higher concentrations of Cl, Na, K, B, Ba, but lower concentrations Of SO4, Ca, and Mg than the shallower waters. Fluid inclusion salinities are also higher in the deeper rocks. The measured Na/Cl ratios of the geothermal well waters are more or less uniform throughout the field and are very similar to that of seawater, strongly suggesting a seawater component in the fluid of the LTV system. The heat stored in the LTV geothermal system was estimated to be at least 9 x 10(12) MJ, of which some 4 x 10(11) MJ (equivalent to about 148 MWe for 30 years of operation, assuming a conversion efficiency of similar to 35%) might be extracted using wells. These results indicate that the installed capacity at LTV could be safely increased from the current 10 MWe. (c) 2006 CNR. Published by Elsevier Ltd. All rights reserved. C1 UNAM, Ctr Invest Energia, Temixco 62580, Morelos, Mexico. Univ Autonoma Estado Morelos, CIICAp, Cuernavaca 62210, Morelos, Mexico. UNAM, Ctr Geociencias, Queretaro 76001, Mexico. Comis Fed Elect, Morelia 58290, Michoacan, Mexico. RP Verma, SP, UNAM, Ctr Invest Energia, Privada Xochicalco S-N,Col Ctr,Apartado Postal 34, Temixco 62580, Morelos, Mexico. EM spv@cie.unam.mx CR ANDAVERDE J, 2005, GEOPHYS J INT, V160, P1112 ANGULO R, 1987, HEAT REC SYST, V7, P129 BARNETT V, 1994, OUTLIERS STAT DATA BEARMAN G, 1989, OCEAN CHEM DEEP SEA BERTANI R, 2005, GEOTHERMICS, V34, P651 BEVINGTON PR, 1969, DATA REDUCTION ERROR BRUTON CJ, 1997, 22 WORKSH GEOTH RES, P457 CAPRA L, 1998, J VOLCANOL GEOTH RES, V80, P239 DEMICCO RV, 2005, GEOLOGY, V33, P877 DOWDLE WL, 1975, J PETROL TECHNOL, V27, P1326 EBDON D, 1988, STAT GEOGRAPHY FLORESARMENTA M, 2001, GEOTHERM RESOUR COUN, V25, P525 GARDUNOMONROY VH, 1993, J VOLCANOL GEOTH RES, V59, P47 GIGGENBACH WF, 1991, APPL GEOCHEMISTRY GE, P119 GOLDBERG ED, 1963, COMPOSITION SEA WATE, V2, P3 GONZALEZPARTIDA E, 2005, APPL GEOCHEM, V20, P23 GUTIERREZNEGRIN LC, 2004, GEOTERMIA REV MEX GE, V17, P21 HAAS JL, 1971, ECON GEOL, V66, P940 HINOJOSA ET, 2005, THESIS U NACL AUTONO HOME RA, 1969, MAR CHEM, P568 KORONEOS C, 2003, RENEW ENERG, V28, P295 LOPEZ HA, 1998, GEOTERMIA REV MEXICA, V14, P3 MENDIOLA JML, 1989, GEOTERMIA REV MEX GE, V5, P89 NICHOLSON K, 1993, GEOTHERMAL FLUIDS PARTIDA EG, 2001, ING HIDRAUL MEX, V16, P47 PORTUGAL E, 2000, J VOLCANOL GEOTH RES, V101, P223 PROLLEDESMA RM, 2004, J VOLCANOL GEOTH RES, V137, P311 RAO NS, 1998, COMPUT GEOSCI, V24, P991 SANCHEZUPTON P, THESIS U NACL AUTONO SANTOYO E, 1991, J VOLCANOL GEOTH RES, V47, P161 SCHIFFMAN P, 1984, GEOLOGY, V12, P12 TORRESALVARADO IS, 2002, INT GEOL REV, V44, P639 VERMA MP, 2000, GEOTHERMICS, V29, P323 VERMA MP, 2002, GEOTHERMICS, V31, P677 VERMA SP, 1997, J VOLCANOL GEOTH RES, V79, P9 VERMA SP, 1998, GEOSTANDARD NEWSLETT, V22, P209 VERMA SP, 2002, GEOTHERMAL ENERGY RE, P195 VERMA SP, 2005, ESTADISTICA MANEJO D YOSHINOBU AS, 1998, J STRUCT GEOL, V20, P1205 NR 39 TC 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0375-6505 J9 GEOTHERMICS JI Geothermics PD APR PY 2006 VL 35 IS 2 BP 156 EP 180 PG 25 SC Energy & Fuels; Geosciences, Multidisciplinary GA 037OJ UT ISI:000237156100005 ER PT J AU Pena-Mendez, Y Nair, MTS Nair, PK TI Thin films of arsenic sulfide by chemical deposition and formation of InAs SO SEMICONDUCTOR SCIENCE AND TECHNOLOGY LA English DT Article ID BATH DEPOSITION; ELECTRICAL PROPERTIES; N-TYPE; SB2S3; SELENIDE; GROWTH; BI2S3 AB We report a method for obtaining thin films of arsenic sulfide by chemical bath deposition and the subsequent formation of InAs by heating the films with a vacuum-deposited coating of In. X-ray diffraction (XRD) studies have shown that the thin film deposited from chemical baths of pH similar to 2, prepared by mixing aqueous acidic solutions of As(III) with sodium thiosulfate, is a composite film of crystalline As2O3 and As2S3, with the incorporation of sulfur. When heated at 150-250 degrees C, the As2O3 component transforms to AS(2)S(3), but still with very few identifiable peaks in the XRD patterns of the annealed samples. The films have a direct band gap of approximate to 2.7 eV (as-prepared) and 2.52 eV (heated at 250 degrees C), with forbidden optical transitions. The sheet resistance of the film (300 nm thick) is 10(12) Omega, and the electrical conductivity is 10(-8) Omega(-1) cm(-1). After being heated in a sulfur-rich atmosphere at > 200 degrees C, the films show photosensitivity. The As2O3/As2S3 thin film with an evaporated indium film, when heated at 250 degrees C in nitrogen or air, produces InAs as a major crystalline component. In this case, In2S3 or In2O3 may be present as a minor component in the films, depending on whether heating is done in nitrogen or air, respectively. The optical band gap of this InAs component is direct, 0.5 to 0.8 eV, depending on the film thickness and heating process. These composite films are photosensitive; a dark conductivity of 0.05 Omega(-1) cm(-1) in the films formed in nitrogen is ascribed to InAs and 5 Omega(-1) cm(-1) in the films formed by heating in air is ascribed to the In2O3 component. The photoconductivity of the films is of the same order of magnitude as the dark conductivity in each case. C1 Univ Nacl Autonoma Mexico, Ctr Invest Energia, Dept Solar Energy Mat, Temixco 62580, Morelos, Mexico. RP Pena-Mendez, Y, Univ Nacl Autonoma Mexico, Ctr Invest Energia, Dept Solar Energy Mat, Temixco 62580, Morelos, Mexico. EM mtsn@cie.unam.mx CR AYLWARD GH, 1974, SI CHEM DATA BINDU K, 2005, SEMICOND SCI TECH, V20, P496 CIMPL Z, 1997, J NONCRYST SOLIDS, V97, P439 DIKOVA J, 2000, VACUUM, V58, P490 FITZGERALD AG, 1982, THIN SOLID FILMS, V98, P101 FORNERIS R, 1969, AM MINERAL, V54, P1062 FRANK G, 1981, THIN SOLID FILMS, V77, P107 GARCIA VM, 1996, J ELECTROCHEM SOC, V143, P2892 GARCIA VM, 1997, SEMICOND SCI TECH, V12, P645 GEORGE PJ, 1996, J CRYST GROWTH, V158, P53 GREENWOOD NN, 1984, CHEM ELEMENTS, P674 HERZBERG G, 1945, ATOMIC SPECTRA ATOMI, P154 HOWSON RP, 1968, J PHYS D APPL PHYS, V1, P939 HUANG L, 1995, THIN SOLID FILMS, V268, P49 MADELUNG O, 1992, SEMICONDUCTORS OTHER, P49 MANE RS, 2000, MATER CHEM PHYS, V64, P215 MICHELETTI FB, 1967, APPL PHYS LETT, V10, P136 MITTAL KL, 1992, SILANES OTHER COUPLI NAIR MTS, 1990, SEMICOND SCI TECH, V5, P1225 NAIR MTS, 1998, J ELECTROCHEM SOC, V145, P2113 NAIR MTS, 2000, J CRYST GROWTH, V208, P248 NAIR PK, 1998, SOL ENERG MAT SOL C, V52, P313 NAIR PK, 1999, J CRYST GROWTH, V206, P68 NAIR PK, 2001, SEMICOND SCI TECH, V16, P855 NIESEN TP, 2001, J ELECTROCERAM, V6, P169 ORTON JW, 1982, J APPL PHYS, V53, P1602 RODE AV, 2002, APPL SURF SCI, V197, P481 RODRIGUEZLAZCANO Y, 2001, J CRYST GROWTH, V223, P399 RODRIGUEZLAZCANO Y, 2005, J ELECTROCHEM SOC, V152, G635 RODRIGUEZLAZCANO Y, 2005, THIN SOLID FILMS, V493, P77 SAINOV S, 2003, VACUUM, V69, P365 SANTIAGO JJ, 1987, THIN SOLID FILMS, V147, P275 SARTALE SD, 2000, MATER RES BULL, V35, P1345 SCHRODER DK, 1990, SEMICONDUCTOR MAT DE SMITH JD, 1973, COMPREHENSIVE INORGA, P547 SMITH RA, 1978, SEMICONDUCTORS+, P313 SZE SM, 1981, PHYSICS SEMICONDUCTO, P849 WHITE K, 1988, THIN SOLID FILMS, V161, P139 YESUGADE NS, 1995, THIN SOLID FILMS, V263, P145 NR 39 TC 0 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0268-1242 J9 SEMICOND SCI TECHNOL JI Semicond. Sci. Technol. PD APR PY 2006 VL 21 IS 4 BP 450 EP 461 PG 12 SC Engineering, Electrical & Electronic; Materials Science, Multidisciplinary; Physics, Condensed Matter GA 036DZ UT ISI:000237052500009 ER PT J AU Hinojosa, JF Alvarez, G Estrada, CA TI Three-dimensional numerical simulation of the natural convection in an open tilted cubic cavity SO REVISTA MEXICANA DE FISICA LA English DT Article DE open cavities; natural convection; three dimensional numerical simulation ID BUOYANCY-DRIVEN FLOWS; SHALLOW OPEN CAVITIES; HEAT-TRANSFER; ENCLOSURES; BOUNDARIES AB In this work the numerical results of the heat transfer by natural convection in a tilted open cubic cavity are presented. The most important assumptions in the mathematical formulation are two: the flow is laminar, and the Boussinesq approximation is valid. The conservation equations in primitive variables are solved using the finite volume method, and the SIMPLEC algorithm. The advective terms are approximated by the SMART scheme, and the diffusive terms are approximated using the central differencing scheme. The results in the steady state are obtained for a Rayleigh range from 10(4) to 10(7) and for a range of 0-180 degrees for the inclination angles of the cavity. The results show that for high Rayleigh numbers, the Nusselt number changes substantially with the inclination angle of tile cavity. The numerical model predicted Nusselt number oscillations for low angles and high Rayleigh numbers. C1 Univ Sonora, Dept Ingn Quim & Met, Hermosillo, Sonora, Mexico. UNAM, Ctr Invest Energia, Temixco 62580, Morelos, Mexico. CENIDET, SNIT, SEP, Cuernavaca, Morelos, Mexico. RP Hinojosa, JF, Univ Sonora, Dept Ingn Quim & Met, Hermosillo, Sonora, Mexico. EM fhinojosa@iq.uson.mx gaby@cenidet.edu.mx cestrada@cie.unam.mx CR ANGIRASA D, 1992, NUMER HEAT TR A-APPL, V22, P223 CHAKROUN W, 1997, J SOL ENERG-T ASME, V119, P298 CHAN YL, 1985, INT J HEAT MASS TRAN, V28, P603 CHAN YL, 1985, NUMER HEAT TRANSFER, V8, P65 CHAN YL, 1986, J HEAT TRANS-T ASME, V108, P305 ELSAYED MM, 1999, J HEAT TRANS-T ASME, V121, P819 GASKELL PH, 1988, INT J NUMER METH ENG, V8, P617 HUMPHREY JAC, 1986, INT J HEAT MASS TRAN, V29, P593 KHANAFER K, 2000, INT J HEAT MASS TRAN, V43, P4087 KHANAFER K, 2002, INT J HEAT MASS TRAN, V45, P2527 LEQUERE P, 1981, NUMERICAL HEAT TRANS, V4, P249 MOHAMAD AA, 1995, NUMER HEAT TR A-APPL, V27, P705 PENOT F, 1982, NUMERICAL HEAT TRANS, V5, P421 POLAT O, 2003, INT J HEAT MASS TRAN, V46, P1563 SEZAI I, 1998, INT J NUMER METHOD H, V8, P800 SHOWOLE RA, 1993, J HEAT TRANS-T ASME, V115, P592 STONE HL, 1968, SIAM J NUMER ANAL, V5, P530 VAFAI K, 1990, INT J HEAT MASS TRAN, V33, P2311 VANDOORMAAL JP, 1984, NUMER HEAT TRANSFER, V7, P147 WAKASHIMA S, 2004, INT J HEAT MASS TRAN, V47, P853 NR 20 TC 0 PU SOCIEDAD MEXICANA DE FISICA PI COYOACAN PA APARTADO POSTAL 70-348, COYOACAN 04511, MEXICO SN 0035-001X J9 REV MEX FIS JI Rev. Mex. Fis. PD APR PY 2006 VL 52 IS 2 BP 111 EP 119 PG 9 SC Physics, Multidisciplinary GA 038GN UT ISI:000237207200004 ER PT J AU Marin-Santibanez, BM Perez-Gonzalez, J de Vargas, L Rodriguez-Gonzalez, F Huelsz, G TI Rheometry - PIV of shear-thickening wormlike micelles SO LANGMUIR LA English DT Article ID DILUTE SURFACTANT SOLUTIONS; MAGNETIC-RESONANCE MICROSCOPY; FLOW BIREFRINGENCE; CETYLTRIMETHYLAMMONIUM BROMIDE; ELONGATIONAL FLOW; AQUEOUS-SOLUTIONS; PHASE-TRANSITION; MODEL; BEHAVIOR; STRESS AB The shear-thickening behavior of an equimolar semidilute aqueous solution of 40 mM/L cetylpyridinium chloride and sodium salicylate was studied in this work by using a combined method of rheometry and particle image velocimetry (PIV). Experiments were conducted at 27.5 degrees C with Couette, vane-bob, and capillary rheometers in order to explore a wide shear stress range as well as the effect of boundary conditions and time of flow on the creation and destruction of shear-induced structures (SIS). The use of the combined method of capillary rheometry with PIV allowed the detection of fast spatial and temporal variations in the flow kinematics, which are related to the shear-thickening behavior and the dynamics of the SIS but are not distinguished by pure rheometrical measurements. A rich-in-details flow curve was found for this solution, which includes five different regimes. Namely, at very low shear rates a Newtonian behavior was found, followed by a shear thinning one in the second regime. In the third, shear banding was observed, which served as a precursor of the SIS and shear-thickening. The fourth and fifth regimes in the flow curve were separated by a spurtlike behavior, and they clearly evidenced the existence of shear-thickening accompanied by stick-slip oscillations at the wall of the rheometer, which subsequently produced variations in the shear rate under shear stress controlled flow. Such a stick-slip phenomenon prevailed up to the highest shear stresses used in this work and was reflected in asymmetric velocity profiles with spatial and temporal variations linked to the dynamics of creation and breakage of the SIS. The presence of apparent slip at the wall of the rheometer provides an energy release mechanism which leads to breakage of the SIS, followed by their further reformation during the stick part of the cycles. In addition, PIV measurements allowed the detection of apparent slip at the wall, as well as mechanical failures in the bulk of the fluid, which suggests an extra contribution of the shear stress field to the SIS dynamics. Increasing the residence time of the fluid in the flow system enhanced the shear-thickening behavior. Finally, the flow kinematics is described in detail and the true flow curve is obtained, which only partially fits into the scheme of existing theoretical models for shear-thickening solutions. C1 Inst Politecn Nacl, Escuela Super Fis & Matemat, Lab Reol, Mexico City 07051, DF, Mexico. UNAM, Mexico City, DF, Mexico. UNAM, Ctr Invest Energia, Temixco, Morelos, Mexico. RP Perez-Gonzalez, J, Inst Politecn Nacl, Escuela Super Fis & Matemat, Lab Reol, Apdo Postal 118-209, Mexico City 07051, DF, Mexico. EM jpg@esfm.ipn.mx CR ADRIAN A, 2005, EUROPHYS LETT, V70, P397 AZZOUZI H, 2005, EUR PHYS J E, V17, P507 BANDYOPADHYAY R, 2000, PHYS REV LETT, V84, P2022 BERRET JF, 1994, EUROPHYS LETT, V25, P521 BERRET JF, 1994, J PHYS II, V4, P1261 BERRET JF, 2000, EUR PHYS J E, V2, P343 BERRET JF, 2001, EUROPHYS LETT, V54, P605 BERRET JF, 2002, LANGMUIR, V18, P7279 BOLTENHAGEN P, 1997, PHYS REV LETT, V79, P2359 BRITTON MM, 1999, J RHEOL, V43, P897 CALLAGHAN PT, 1996, J PHYS II, V6, P375 CATES ME, 1990, J PHYS-CONDENS MAT, V2, P6869 FIELDING SM, 2004, PHYS REV LETT, V92 FISCHER P, 2000, RHEOL ACTA, V39, P234 FISCHER P, 2002, RHEOL ACTA, V41, P36 HARTMANN V, 1997, J PHYS II, V7, P1087 HASHIMOTO T, 2005, NIHON REOROJI GAKK, V33, P1 HEAD DA, 2002, EUROPHYS LETT, V57, P120 HERLE V, 2005, LANGMUIR, V21, P9051 HERNANDEZACOSTA S, 1999, J NON-NEWTON FLUID, V85, P229 HOFMANN S, 1991, BER BUNSEN PHYS CHEM, V95, P153 HU HT, 1998, J RHEOL, V42, P1185 HU HT, 1998, J RHEOL, V42, P1209 HU Y, 1993, COLLOID INTERFACE SC, V156, P31 HU Y, 1994, J PHYS CHEM-US, V98, P8555 HU Y, 1994, LANGMUIR, V10, P80 HU YT, 1993, J RHEOL, V37, P531 KOCH S, 1998, J NON-NEWTON FLUID, V78, P47 MACIAS ER, 2001, J NON-NEWTON FLUID, V101, P149 MACIAS ER, 2003, J RHEOL, V47, P643 MAIR RW, 1997, J RHEOL, V41, P901 MAKHLOUFI R, 1995, EUROPHYS LETT, V32, P253 MENDEZSANCHEZ AF, 2003, J RHEOL, V47, P1455 MENDEZSANCHEZ AF, 2003, RHEOL ACTA, V42, P56 ODA R, 1997, LANGMUIR, V13, P6407 OHLENDORF D, 1984, ADV RHEOLOGY, V2, P41 OLMSTED PD, 1997, PHYS REV E, V56, P55 PALBERG T, 1996, J PHYS I, V6, P237 PORTE G, 1997, J PHYS II, V7, P459 PROTZL B, 1997, J COLLOID INTERF SCI, V190, P327 PRUDHOMME RK, 1994, LANGMUIR, V10, P3419 RADULESCU O, 1999, RHEOL ACTA, V38, P606 RAFFEL M, 1998, PARTICLE IMAGE VELOC REHAGE H, 1991, MOL PHYS, V74, P933 ROFE CJ, 1996, J RHEOL, V40, P1115 ROLONGARRIDO VH, 2003, REV MEX FIS, V49, P40 SPENLEY NA, 1996, J PHYS II, V6, P551 WUNDERLICH I, 1987, RHEOL ACTA, V26, P532 NR 48 TC 4 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0743-7463 J9 LANGMUIR JI Langmuir PD APR 25 PY 2006 VL 22 IS 9 BP 4015 EP 4026 PG 12 SC Chemistry, Physical GA 035GR UT ISI:000236989300012 ER PT J AU van Afferden, M Hansen, AM Kaiser, C Chapelain, N TI Laboratory test system to measure microbial respiration rate SO INTERNATIONAL JOURNAL OF ENVIRONMENT AND POLLUTION LA English DT Article DE soil respiration; CO2 evolution; online conductivity measurement; soil studies ID SOIL RESPIRATION; CHAMBER SYSTEM; FIELD; RESPIROMETER AB This Study reports a sensible, accurate and economic method for continuous measuring microbial respiration. The Measuring principle is ail open system, with a continuous air-flow through. Evolved CO, is absorbed and precipitated as carbonate by a Ba(OH)(2) solution, causing a stoichiometrical decrease in ionic strength of the Solution and in electrical conductivity. Conductivity and Ba(OH)2 concentration correlate over a range of more than three orders of magnitude with a determination coefficient of r(2) = 0.999. Between 20 degrees C and 50 degrees C and Ba(OH)(2) concentrations of up to 0.099M, all automated temperature correction was developed. The system detects evolved CO, quantitatively up to a maximum of 0.22 mmol O-2 min(-1) (825 mbar, 20 degrees C) before limiting microbial respiration. A maximum CO, flow of 1.06 mmol min(-1) is quantitatively absorbed under these conditions. The method was applied to characterise soil respiration of a soil sample from ail agricultural experimental site in Tabasco, Mexico. C1 Inst Mexicano Tecnol Agua, Jiutepec 62550, Morelos, Mexico. RP van Afferden, M, Inst Mexicano Tecnol Agua, Paseo Cuauhnahuac 8532,Col Progreso, Jiutepec 62550, Morelos, Mexico. EM afferden@tlaloc.imta.mx ahansen@tlaloc.imta.mx kaiser_mexli@web.de chappy.fr@gmail.com CR *DEV G 1, 1981, WASS GES FACHGR GDCH *OECD, 1981, TEST GUID 304 A INH *OECD, 1992, GUID TEST CHEM READ *OECD, 1992, READ BIOD 301 B CO2 *OECD, 2002, DRAFT PROP NEW GUID *OECD, 2002, GUID TEST CHEM *OECD, 2002, PROP NEW GUID 307 AE *USDA, 1975, SOIL TAX ALEF K, 1994, BIOL BODENSANIERUNG, P43 ALEF K, 1994, BIOL BODENSANIERUNG, P43 BLANKE MM, 1996, ENVIRON EXP BOT, V36, P339 CHAPMAN SB, 1971, OIKOS, V22, P348 DEV GI, 1981, WASSERCHEMISCHE GESE DOTT W, 1995, BIOASSAYS SOIL FANG C, 1998, FUNCTIONAL ECOLOGY, V12, P325 HANSEN AM, 2000, 16 C NAC HIDR MEM AV, P3 HANSEN AM, 2000, MEMORIAS AVANCES HID, V6, P3 JANSSENS IA, 1998, ECOL LETT, V1, P98 KING JA, 2002, COMMUN SOIL SCI PLAN, V33, P403 KIRSCH A, 2000, Z PFLANZENERNAHRUNG, V163, P165 NORDGREN A, 1988, SOIL BIOL BIOCHEM, V20, P955 PAUSTENBACH DJ, 2000, J TOXICOL ENV HEAL B, V3, P179 RAYMENT MB, 1997, J GEOPHYS RES-ATMOS, V102, P28779 VANAFFERDEN M, 2001, INT WORKSH ENV RISK, P102 WEAST RC, 1972, HDB CHEM PHYS ZIMAKOWSKAGNOINSKA D, 2000, ENVIRON MONIT ASSESS, V64, P583 NR 26 TC 0 PU INDERSCIENCE ENTERPRISES LTD PI GENEVA PA WORLD TRADE CENTER BLDG, 29 ROUTE DE PRE-BOIS, CASE POSTALE 896, CH-1215 GENEVA, SWITZERLAND SN 0957-4352 J9 INT J ENVIRON POLLUTION JI Int. J. Environ. Pollut. PY 2006 VL 26 IS 1-3 BP 220 EP 233 PG 14 SC Environmental Sciences GA 037AB UT ISI:000237118000014 ER PT J AU Natividad, C Salazar, M Garcia, R Gonzalez-Rodriguez, JG Perez, R TI Sulphide stress cracking behaviour of weldments produced by indirect electric arc welding SO CORROSION ENGINEERING SCIENCE AND TECHNOLOGY LA English DT Article DE indirect electric arc; sulphide stress cracking; hydrogen embrittlement AB The aim of the present study was to evaluate the corrosion resistance of weldments produced by the Indirect Electric Arc technique. The material studied was API grade X-65 steel, which was corroded in NACE solution saturated with H2S. Three different temperatures were employed, room temperature (25 degrees C), 37 degrees C and 50 degrees C. The test methods used included potentiodynamic polarisation curves, hydrogen permeation measurements and slow strain rate tests. The anodic corrosion current density and sulphide stress cracking susceptibility of the weldments were found to be unaffected by temperature over the range 25-50 degrees C. However, values of the steady-state hydrogen permeation current, hydrogen permeation rate, effective diffusion coefficient, and the concentration of hydrogen atoms at the entrance side all increased with temperature. The cracking of the X-65 weldments is explained in terms of a hydrogen embrittlement mechanism. C1 Univ Nacl Autonoma Mexico, Fac Quim, Mexico City 04510, DF, Mexico. Inst Mexicano Petr, Programa Invest & Desarrollo Ductos, Mexico City 07730, DF, Mexico. UMSNH, Inst Invest Met, Morelia, Michoacan, Mexico. UAEM, CIICAP, Cuernavaca 6225, Morelos, Mexico. RP Salazar, M, Univ Nacl Autonoma Mexico, Fac Quim, Circuito Interior,CU Edificio B, Mexico City 04510, DF, Mexico. EM salazarm@imp.mx CR *NACE TECHN COMM, 1993, SSC RES PIP WELD JAN, P58 ABDELHAMID MH, 2001, CORROSION, V57, P428 BHATTI AR, 1984, WELDING RES S JUL, P224 CRAIG BD, 1998, WELDING J JAN, P61 DEVANATHAN MAV, 1962, P ROY SOC LOND A MAT, V270, P90 GARCIA R, 2002, J MATER SCI LETT, V21, P1965 GARCIA R, 2002, METALL MATER TRANS B, V33, P930 GARCIA R, 2003, J MATER SCI, V38, P2771 GREER JB, 1975, MAT PERFORMANCE MAR, P11 GRONG O, 1994, METALLURGICAL MODELL NR 10 TC 1 PU MANEY PUBLISHING PI LEEDS PA HUDSON RD, LEEDS LS9 7DL, ENGLAND SN 1478-422X J9 CORROS ENG SCI TECHNOL JI Corros. Eng. Sci. Technol. PD MAR PY 2006 VL 41 IS 1 BP 91 EP 95 PG 5 SC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering GA 034JN UT ISI:000236925400021 ER PT J AU Bindu, K Nair, MTS Das Roy, TK Nair, PK TI Chemically deposited photovoltaic structure using antimony sulfide and silver antimony selenide absorber films SO ELECTROCHEMICAL AND SOLID STATE LETTERS LA English DT Article ID THIN-FILMS; OPTICAL-PROPERTIES; BATH DEPOSITION; SB2S3 AB A photovoltaic structure, glass/SnO2:F/n-CdS/Sb2S3/p-AgSbSe2/Ag-print, showing V-oc 550 mV and J(sc) 2.3 mA/cm(2) under 1 kW/m(2) (tungsten halogen) intensity has been developed on commercial SnO2:F-coated glass from chemically deposited thin films of CdS (80 nm), Sb2S3 (450 nm), and Ag2Se (150 nm), and subsequently heating the layer at 200-300 degrees C in contact with a chemically deposited Se thin film. The reaction between Sb2S3 and Ag2Se in the Se vapor forms p-type AgSbSe2 thin film with a bandgap approximate to 1 eV. The methodology for preparing all-chemically deposited photovoltaic structures at process temperatures 300 degrees C or below presented here is compatible with solar cell technology. C1 Univ Nacl Autonoma Mexico, Ctr Invest Energia, Dept Solar Energy Mat, Temixco 62580, Morelos, Mexico. Univ Autonoma Nuevo Leon, Fac Ingn Mecan & Elect, San Nicolas De Los Garza 66450, Nuevo Leon, Mexico. RP Bindu, K, Univ Nacl Autonoma Mexico, Ctr Invest Energia, Dept Solar Energy Mat, Temixco 62580, Morelos, Mexico. EM mtsn@cie.unam.mx CR BINDU K, 2004, SEMICOND SCI TECH, V19, P1348 BINDU K, 2005, SEMICOND SCI TECH, V20, P496 HERMANN D, 2005, MRS SPRING M S SAN F, P164 HODES G, 2003, CHEM SOLUTION DEPOSI, P273 ITO K, 1988, JPN J APPL PHYS, V27, P2094 JAEGERMANN W, 2005, MRS SPRING M S SAN F, P150 KAPUR VK, 2003, THIN SOLID FILMS, V431, P53 KATAGIRI H, 2005, THIN SOLID FILMS, V480, P426 KUKU TA, 1987, SOLAR ENERGY MAT, V16, P199 MADELUNG O, 1992, SEMICONDUCTORS OTHER, P72 NAIR MTS, 1994, J APPL PHYS, V75, P1557 NAIR MTS, 1998, J ELECTROCHEM SOC, V145, P2113 NOGUCHI H, 1994, SOL ENERG MAT SOL C, V35, P325 PEJOVA B, 2000, MATER LETT, V43, P269 RODRIGUEZLAZCANO Y, 2005, J ELECTROCHEM SOC, V152, G635 SMITH RA, 1978, SEMICONDUCTORS+, P313 SOLIMAN HS, 1998, J PHYS-CONDENS MAT, V10, P847 SUAREZSANDOVAL D, 2006, J ELECTROCHEM SOC, V153, P91 TIWARI AN, 2005, THIN SOLID FILMS, V480, P1 NR 19 TC 0 PU ELECTROCHEMICAL SOC INC PI PENNINGTON PA 65 SOUTH MAIN STREET, PENNINGTON, NJ 08534 USA SN 1099-0062 J9 ELECTROCHEM SOLID STATE LETT JI Electrochem. Solid State Lett. PY 2006 VL 9 IS 6 BP G195 EP G199 PG 5 SC Electrochemistry; Materials Science, Multidisciplinary GA 031BQ UT ISI:000236679500024 ER PT J AU Dove, S Ortiz, JC Enriquez, S Fine, M Fisher, P Iglesias-Prieto, R Thornhill, D Hoegh-Guldberg, O TI Response of holosymbiont pigments from the scleractinian coral Montipora monasteriata to short-term heat stress SO LIMNOLOGY AND OCEANOGRAPHY LA English DT Article ID REEF-BUILDING CORALS; PHOTOSYSTEM-II; PHOTOSYNTHETIC RESPONSE; STYLOPHORA-PISTILLATA; XANTHOPHYLL-CYCLE; HERMATYPIC CORAL; SYMBIOTIC ALGAE; LIGHT; CHLOROPHYLL; TEMPERATURE AB Heating the scleractinian coral, Montipora monasteriata (Forskal 1775) to 32 degrees C under < 650 mu mol quanta m(-2) s(-1) led to bleaching in the form of a reduction in Peridinin, xanthophyll pool, chlorophyll c(2) and chlorophyll a, but areal dinoflagellates densities did not decline. Associated with this bleaching, chlorophyll (Chl) allomerization and dinoflagellate xanthophyll cycling increased. Chl allomerization is believed to result from the interaction of Chl with singlet oxygen (O-1(2)) or other reactive oxygen species. Thermally induced increases in Chl allomerization are consistent with other studies that have demonstrated that thermal stress generates reactive oxygen species in symbiotic dinoflagellates. Xanthophyll cycling requires the establishment of a pH gradient across the thylakoid membrane. Our results indicate that, during the early stages of thermal stress, thylakoid membranes are intact. Different morphs of M. monasteriata responded differently to the heat stress applied: heavily pigmented coral hosts taken from a high-light environment showed significant reductions in green fluorescent protein (GFP)-like homologues, whereas nonhost pigmented high-light morphs experienced a significant reduction in water-soluble protein content. Paradoxically, the more shade acclimated cave morph were, based on Chl fluorescence data, less thermally stressed than either of the high-light morphs. These results Support the importance of coral pigments for the regulation of the light environment within the host tissue. C1 Univ Queensland, Ctr Marine Sci, Brisbane, Qld 4072, Australia. Univ Nacl Autonoma Mexico, Unidad Acad Puerto Morelos, Inst Ciencias Mar & Limnol, Cancun 77500, Mexico. Univ Georgia, Inst Ecol, Athens, GA 30602 USA. RP Dove, S, Univ Queensland, Ctr Marine Sci, Brisbane, Qld 4072, Australia. EM Sophie@uq.edu.au CR ADAMSKA I, 1993, J BIOL CHEM, V268, P5438 AMBARSARI I, 1997, MAR ECOL-PROG SER, V159, P303 ANTHONY KRN, 2003, FUNCT ECOL, V17, P246 BAKER AC, 2001, NATURE, V411, P765 BROWN BE, 1999, CORAL REEFS, V18, P99 BUDDERMEIR RW, 1993, BIOSCIENCE, V43, P321 BUMANN D, 1995, P NATL ACAD SCI USA, V92, P12195 COLES SL, 2003, ADV MAR BIOL, V46, P183 DOVE S, 2004, MAR ECOL-PROG SER, V272, P99 DOVE SG, 1995, BIOL BULL, V189, P288 DOVE SG, 2001, CORAL REEFS, V19, P197 DOVE SG, 2002, PCTGB0200928 WORLD I DUNN SR, 2002, J EXP MAR BIOL ECOL, V272, P29 ENRIQUEZ S, 2005, LIMNOL OCEANOGR, V50, P1025 FAGOONEE I, 1999, SCIENCE, V283, P843 FALKOWSKI PG, 1981, NATURE, V289, P172 FITT WK, 2000, LIMNOL OCEANOGR, V45, P667 FITT WK, 2001, CORAL REEFS, V20, P51 FITT WK, 2001, J EXP MAR BIOL ECOL, V256, P15 GATES RD, 1992, BIOL BULL, V182, P324 GREEN BR, 1996, ANNU REV PLANT PHYS, V47, P685 HAGAR A, 1970, ARCH MICROBIOL, V73, P7 HAVAUX M, 1996, PLANTA, V198, P324 HAVAUX M, 1999, P NATL ACAD SCI USA, V96, P8762 HIGHSMITH RC, 1981, J EXP MAR BIOL ECOL, V55, P267 HOEGHGULDBERG O, 1989, J EXP MAR BIOL ECOL, V129, P279 HOEGHGULDBERG O, 1999, MAR FRESHWATER RES, V50, P839 HYNNINEN PH, 1991, CHLOROPHYLLS, P145 IGLESIASPRIETO R, 1992, P NATL ACAD SCI USA, V89, P10302 IGLESIASPRIETO R, 1997, MAR BIOL, V130, P23 IGLESIASPRIETO R, 1997, P 8 INT COR REEF S, V2, P1313 JONES RJ, 1998, PLANT CELL ENVIRON, V21, P1219 KROL M, 1995, PLANT PHYSIOL, V107, P873 LAJEUNESSE TC, 2001, J PHYCOL, V37, P866 LAJEUNESSE TC, 2003, LIMNOL OCEANOGR, V48, P2046 LIU K, 2004, PHOTOSYNTH RES, V81, P41 MAXWELL DP, 1995, PLANT PHYSIOL, V107, P687 MEWES H, 2002, PLANT PHYSIOL, V130, P1527 MONTANE MH, 1998, PLANT PHYSIOL, V118, P227 MUNEKAGE U, 2004, NAT BIOTECHNOL, V479, P579 NEUBAUER C, 1992, PLANT PHYSIOL, V99, P1354 NIYOGI KK, 1999, ANNU REV PLANT PHYS, V50, P333 TAKAHASHI S, 2004, PLANT CELL PHYSIOL, V45, P251 TARDY F, 1997, BBA-BIOMEMBRANES, V1330, P179 TAYLOR DL, 1973, ANNU REV MICROBIOL, V27, P171 TCHERNOV D, 2004, P NATL ACAD SCI USA, V101, P13531 TELFER A, 1994, J BIOL CHEM, V269, P13244 THOMAS H, 1997, NEW PHYTOL, V136, P163 THOMPSON LK, 1988, BIOCHEMISTRY-US, V27, P6653 TRENCH RK, 1979, ANNU REV PLANT PHYS, V30, P485 VICENTINI F, 1995, NEW PHYTOL, V129, P247 WALTERS RG, 2004, J EXP BOT, V56, P435 WANG JM, 2000, PHOTOCHEM PHOTOBIOL, V71, P84 WARNER ME, 1999, P NATL ACAD SCI USA, V96, P8007 WARNER ME, 2002, MAR BIOL, V141, P31 WHITAKER JR, 1980, ANAL BIOCHEM, V109, P156 ZAPATA M, 2000, MAR ECOL-PROG SER, V195, P29 NR 57 TC 6 PU AMER SOC LIMNOLOGY OCEANOGRAPHY PI WACO PA 5400 BOSQUE BLVD, STE 680, WACO, TX 76710-4446 USA SN 0024-3590 J9 LIMNOL OCEANOGR JI Limnol. Oceanogr. PD MAR PY 2006 VL 51 IS 2 BP 1149 EP 1158 PG 10 SC Limnology; Oceanography GA 026MS UT ISI:000236343600035 ER PT J AU Birkle, P Angulo, M Lima, S TI Hydrochemical-isotopic tendencies to define hydraulic mobility of formation water at the Samaria-Sitio Grande oil field, Mexico SO JOURNAL OF HYDROLOGY LA English DT Article DE oil reservoir; formation water; stable isotopes; tracer tests; hydraulic communication; geochemical processes ID CANADA SEDIMENTARY BASIN; GROUNDWATER-FLOW; FLUID-FLOW; ORIGIN; METHANE; BRINES AB The chemical (major elements) and isotopic (H-2, H-3, C-13, O-18) composition of formation water is presented for the Sitio Grande oilfield, SE-Mexico, extracted from 28 production wells from the carbonate reservoir at a depth between 3585 and 4545 m.b.s.l. The linear delta O-18/delta D-trend explains the formation of reservoir water as part of three subsequent stages: a) the evaporation of marine water at the surface, causing enrichment of both, delta O-18 and delta D-values, b) a reversal trend with decreasing delta O-18-and delta D-ratios by the extreme evaporation of brines and, c) the subsequent mixing with isotopically depleted meteoric water. A SW-NE directed flow direction of deep groundwater systems is indicated by parallel-oriented isoline trends of stable isotope ratios and conservative elements, supported by the dominance of parallel directed microfractures and extensional faults, and by tracer test results. The arrival of artificial tritium, three years after tracer injection in the well SG-85, reflects a) the importance of long-term monitoring of tracer tests, and b) an estimated flow velocity of 2.2X10(-5) m/s. As the arrival of the tracer was detected exclusively in three production wells towards the SW of the injection site, lateral migration of groundwater occurs mainly along defined, channel-like conducts with a narrow dispersion angle of 39 degrees. Surface water, injected as part of an enhanced oil recovery program, was not detected in the production zone by chemical and isotopic methods. This fact is not a proof for lacking hydraulic conductivity, as the large reservoir size and the termination of the injection program in 1996 could have caused a complete dilution of the injected fluids. Restricted vertical flow movement between reservoir layers and insignificant temperature-dependent reaction processes is indicated by the heterogeneous distribution of delta O-18-and Cl-values throughout the groundwater column of most reservoir zones. Little influence of water-rock interaction, such as Ca-Mg exchange processes between formation water and host rock is reflected by the heterogeneous abundance of calcium in the liquid phase in both, dolomite-free and dolomitized carbonate host rock layers. (c) 2005 Elsevier B.V. All rights reserved. C1 Inst Invest Elect Gerencia Geotermia, Cuernavaca, Morelos, Mexico. PEMEX Explorac & Prod, Chiapas, Mexico. RP Birkle, P, Inst Invest Elect Gerencia Geotermia, Av Reforms 113 Col Palmire, Cuernavaca, Morelos, Mexico. EM birkle@iie.org.mx CR *IAEA, 1992, TECHN REP SER, V331 *IMP, 1997, EST RAD CAMP SIT GRA AGUILAR AR, 1998, B TRIMESTRAL PEMEX E, V5, P1 AGUILAR AR, 1999, B TRIMESTRAL PEMEX E, V6, P5 AGUILAR AR, 2001, B TRIMESTRAL PEMEX E, V9, P5 AGUILAR AR, 2003, B TRIMESTRAL PEMEX E, P8 BARKER JF, 1981, CAN J EARTH SCI, V18, P1802 BETHKE CM, 1988, SCIENCE, V239, P261 BIRKBECK DP, 2001, ATHLET THER TODAY, V6, P6 BIRKLE P, IN PRESS APPL GEOCHE BIRKLE P, 2002, AAPG BULL, V86, P457 BIRKLE P, 2003, J GEOCHEM EXPLOR, V78, P453 BITZER K, 2000, J GEOCHEM EXPLOR, V69, P127 CLAYTON RN, 1966, J GEOPHYS RES, V71, P3869 EPSTEIN S, 1953, GEOCHIMICA COSMOCHIM, V4, P89 EVANS DG, 1991, GEOPHYS RES LETT, V18, P927 FRITZ P, 1987, GEOL ASSOC CAN SPEC, V33, P211 FUNAYAMA M, 1992, AM ASS PETR GEOL ABS, P44 GARVEN G, 1989, AM J SCI, V289, P105 GONFIANTINI R, 1965, ATTI SOC TOSCANA S A, V72, P550 GUZMAN VM, 2000, GEOQUIMICA YACIMIENT GUZMANVEGA MA, 1999, AAPG BULL, V83, P1068 HANOR JS, 1994, MAR PETROL GEOL, V11, P31 KHARAKA YK, 1973, GEOCHIM COSMOCHIM AC, V37, P1899 MACHEL HG, 2000, J GEOCHEM EXPLOR, V69, P213 MANN WB, 1983, P 11 INT RAD DAT C R, V25 PEARSON FJ, 1970, ISOTOPE HYDROLOGY, P271 SALVADOR A, 1991, GEOLOGY N AM, V4 SCHOELL M, 1980, GEOCHIM COSMOCHIM AC, V44, P649 STAHL WJ, 1979, LECT ISOTOPE GEOLOGY, P274 TANWEER A, 1993, ANALYST, V118, P835 WEAVER TR, 1995, GEOL SOC AM BULL, V107, P697 WEST RC, 1987, TIERRAS BAJAS TABASC YEH HW, 1980, GEOCHIMICA COSMOCHIM, V47, P1487 NR 34 TC 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-1694 J9 J HYDROL JI J. Hydrol. PD FEB 20 PY 2006 VL 317 IS 3-4 BP 202 EP 220 PG 19 SC Engineering, Civil; Geosciences, Multidisciplinary; Water Resources GA 022MB UT ISI:000236058800004 ER PT J AU Barba, V Villamil, R Luna, R Godoy-Alcantar, C Hopfl, H Beltran, HI Zamudio-Rivera, LS Santillan, R Farfan, N TI Boron macrocycles having a calix-like shape. Synthesis, characterization, X-ray analysis, and inclusion properties SO INORGANIC CHEMISTRY LA English DT Article ID HETEROATOM-BRIDGED CALIXARENES; BINDING-PROPERTIES; METAL-BINDING; COMPLEXES; CAVITY; CONSTRUCTION; RECOGNITION; MOLECULES; LIGANDS; IONS AB The syntheses, structure, and inclusion properties of trinuclear boron compounds having a calix-like shape are described. The compounds have been obtained via self-assembly reactions between salicylaldehyde derivatives and 3-aminophenylboronic acid, whereby the formation of three N -> B coordination bonds favored the oligomerization. The products have high melting points (> 370 degrees C), are stable to moisture, and have good solubility in organic solvents; the latter property is useful for host-guest recognition experiments. The structural analysis by X-ray diffraction revealed that diverse conformations are possible because of the presence of two different units of aromatic rims. A cone-cone (double-cone) conformation is observed for three of these compounds, while the remaining one has a cone-partial cone conformation. An analysis of the molecular packing showed that the molecules are stacked in columns in two different orientations in relation to the organization of the macrocycles when referred to the N-B bonds. The inclusion properties toward primary amines and ammonium chlorides were analyzed by titration experiments and monitored by UV spectroscopy, whereby association constants on the order of 10(2)-10(3) M-1 were determined. C1 Univ Autonoma Estado Morelos, Ctr Invest Quim, Cuernavaca 62209, Morelos, Mexico. UNAM, Inst Quim, Mexico City 04510, DF, Mexico. Inst Mexicano Petr, Programa Ingn Mol, Mexico City 07730, DF, Mexico. Inst Politecn Nacl, Ctr Invest & Estudios Avanzados, Dept Quim, Mexico City 07000, DF, Mexico. UNAM, Fac Quim, Dept Quim Organ, Mexico City 04510, DF, Mexico. RP Barba, V, Univ Autonoma Estado Morelos, Ctr Invest Quim, Ave Univ 101, Cuernavaca 62209, Morelos, Mexico. EM vbarba@ciq.uaem.mx CR *ADV CHEM DEV INC, 1994, ACD LABS *BRUK AN XRAY SYST, 2000, SHELXTL NT VERS 6 10 *BRUK AN XRAY SYST, 2001, SAINT NT VERS 6 04 AKDAS H, 1998, TETRAHEDRON LETT, V39, P2311 ARAKI K, 1993, TETRAHEDRON, V49, P9465 ARAKI K, 1996, ANGEW CHEM INT EDIT, V35, P72 ARDUINI A, 2000, EUR J ORG CHEM JUN, P2325 ATWOOD JL, 2002, SCIENCE, V296, P2367 BARBA V, 2001, J ORGANOMET CHEM, V622, P259 BARBA V, 2004, CHEM COMMUN, P2834 BARBA V, 2005, J ORGANOMET CHEM, V690, P2351 BOHMER V, 1995, ANGEW CHEM INT EDIT, V34, P713 BOTTINO A, 1999, J ORG CHEM, V64, P8018 BUHLER RE, 1972, J PHYS CHEM-US, V76, P3220 CHRISTINAT N, 2004, CHEM COMMUN 0521, P1158 CONNORS KA, 1987, BINDING CONSTANTS ME, P24 DAITCH CE, 1996, J AM CHEM SOC, V118, P7769 GOPALSAMUTHIRAM V, 2004, J AM CHEM SOC, V126, P13936 GUTSCHE CD, 1981, J AM CHEM SOC, V103, P3782 HAMPTON PD, 1996, J CHEM SOC PERK JUN, P1127 HOLLIDAY BJ, 2001, ANGEW CHEM INT EDIT, V40, P2022 HOPFL H, 2002, STRUCT BOND, V103, P1 IKEDA A, 1997, CHEM REV, V97, P1713 IKI N, 2000, TETRAHEDRON, V56, P1437 JAMES TD, 1996, ANGEW CHEM INT EDIT, V35, P1910 KONIG B, 2000, EUR J INORG CHEM NOV, P2303 KUSUKAWA T, 1998, ANGEW CHEM INT EDIT, V37, P3142 LEON S, 2002, CHEM-EUR J, V8, P4854 LEVERD PC, 2000, EUR J ORG CHEM JAN, P133 LEVERD PC, 2001, EUR J INORG CHEM AUG, P2021 SCHNEIDER HJ, 2000, PRINCIPLES METHODS S, P142 SUGIHARA Y, 1996, J ORG CHEM, V61, P6829 THUERY P, 2001, EUR J INORG CHEM MAR, P637 WANG MX, 2004, J AM CHEM SOC, V126, P15412 WEISS A, 2003, J ORGANOMET CHEM, V680, P294 YAMATO T, 2001, EUR J ORG CHEM MAR, P1069 NR 36 TC 3 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0020-1669 J9 INORG CHEM JI Inorg. Chem. PD MAR 20 PY 2006 VL 45 IS 6 BP 2553 EP 2561 PG 9 SC Chemistry, Inorganic & Nuclear GA 023IG UT ISI:000236119700034 ER PT J AU Cabrera-Valladares, N Martinez, A Pinero, S Lagunas-Munoz, VH Tinoco, R de Anda, R Vazquez-Duhalt, R Bolivar, F Gosset, G TI Expression of the melA gene from Rhizobium etli CFN42 in Escherichia coli and characterization of the encoded tyrosinase SO ENZYME AND MICROBIAL TECHNOLOGY LA English DT Article DE Rhizobium etli; Escherichia coli; melA gene; tyrosinase; melanin ID NITROGEN-FIXATION; PURIFICATION; BIOSYNTHESIS; PHASEOLI; PLASMID; TRANSCRIPTION; CLONING; MUTANT AB The gene melA from the nitrogen-fixing bacterium Rhizobium etli CFN42 was amplified using PCR, cloned in the expression vector pTtrc99A to obtain plasmid pTrcmelA, and transformed into E. coli strain W3110. The resulting recombinant strain W3110/pTrcmelA synthesized a dark pigment when growing in solid or liquid media containing L-tyrosine and copper. This pigment was identified as melanin by comparing it with analytical grade melanin using a spectrophotometric assay. Melanin was synthesized when recombinant E. coli cells were incubated at 30 degrees C;. however, at 37 degrees C significantly less polymer was produced. The recombinant tyrosinase expressed intracellularly in E. coli was purified 40-fold with a 25% yield from a cell extract by ammonium sulfate precipitation and ion exchange chromatography. With the partially purified tyrosinase, the K. for L-dopa and L-tyrosine were determined as 2.44 and 0.19 mM, respectively. Temperature and pH for maximum activity were 50 degrees C and 6.5-7.5, respectively. Activation energy for thermal inactivation (50.77 kJ/mol; using L-dopa as substrate at pH 7) and half-life values indicate a higher thermal stability of R. etli tyrosinase in comparison with mushroom tyrosinase. Interestingly, for a bacterial tyrosinase, MelA showed an unusually higher activity for L-tyrosine than for L-dopa. (c) 2005 Elsevier Inc. All rights reserved. C1 Univ Nacl Autonoma Mexico, Inst Biotechnol, Dept Ingn Celular & Biocatalisis, Cuernavaca 62250, Morelos, Mexico. RP Gosset, G, Univ Nacl Autonoma Mexico, Inst Biotechnol, Dept Ingn Celular & Biocatalisis, Apdo Postal 510-3, Cuernavaca 62250, Morelos, Mexico. EM gosset@ibt.unam.mx CR BELL AA, 1986, ANNU REV PHYTOPATHOL, V24, P411 BORTHAKUR D, 1987, MOL GEN GENET, V207, P155 COYNE VE, 1992, APPL ENVIRON MICROB, V58, P2861 CUBO MT, 1988, APPL ENVIRON MICROB, V54, P1812 DELLACIOPPA G, 1998, 5837505, US FUQUA WC, 1993, J GEN MICROBIOL, V139, P1105 GARCIABORRON JC, 2002, PIGM CELL RES, V15, P162 GONZALEZ V, 2003, GENOME BIOL, V4 HAWKINS FKL, 1988, MOL MICROBIOL, V2, P331 HEARING VJ, 1987, METHOD ENZYMOL, V142, P154 HENSON JM, 2001, BIOPOLYMERS, P229 HILL HZ, 1992, BIOESSAYS, V14, P49 IKEHATA K, 2000, BIOTECHNOL PROGR, V16, P533 JENSEN KF, 1993, J BACTERIOL, V175, P3401 KONG KH, 1998, BIOCHEM MOL BIOL INT, V45, P717 KONG KH, 2000, BIOTECHNOL APPL BI 2, V31, P113 KONG KH, 2000, COMP BIOCHEM PHYS B, V125, P563 KUPPER U, 1989, J BIOL CHEM, V264, P17250 LAMB JW, 1982, MOL GEN GENET, V186, P449 LERCH K, 1972, EUR J BIOCHEM, V31, P427 MERCADOBLANCO J, 1993, J BACTERIOL, V175, P5403 POMERANTZ SH, 1974, ARCH BIOCHEM, V160, P73 SAXENA D, 2002, CURR MICROBIOL, V44, P25 SHARMA NM, 2003, BIOTECHNOL APPL BI 2, V38, P137 SOLANO F, 2000, J BACTERIOL, V182, P3754 VACHTENHEIM J, 1985, ANAL BIOCHEM, V146, P405 WANG GL, 2000, FEMS MICROBIOL LETT, V185, P23 WANG HT, 1995, BBA-GEN SUBJECTS, V1243, P251 YOSHIMOTO T, 1985, J BIOCHEM-TOKYO, V97, P1747 NR 29 TC 2 PU ELSEVIER SCIENCE INC PI NEW YORK PA 360 PARK AVE SOUTH, NEW YORK, NY 10010-1710 USA SN 0141-0229 J9 ENZYME MICROB TECHNOL JI Enzyme Microb. Technol. PD APR 1 PY 2006 VL 38 IS 6 BP 772 EP 779 PG 8 SC Biotechnology & Applied Microbiology GA 022TJ UT ISI:000236078500008 ER PT J AU San-Roman, M Carrillo-Tripp, M Saint-Martin, H Hernandez-Cobos, J Ortega-Blake, I TI A theoretical study of the hydration of Li+ by Monte Carlo simulations with refined ab initio based model potentials SO THEORETICAL CHEMISTRY ACCOUNTS LA English DT Article DE lithium ion hydration; polarizable force fields; Monte Carlo simulation ID MOLECULAR-DYNAMICS SIMULATION; MOBILE CHARGE-DENSITIES; EFFECTIVE 3-BODY POTENTIALS; HARMONIC-OSCILLATORS MODEL; EFFECTIVE PAIR POTENTIALS; POLARIZABLE FORCE-FIELDS; AQUEOUS-SOLUTIONS; LIQUID WATER; ALKALI-METAL; FLEXIBLE CONSTRAINTS AB Four water models that have the same analytical potential but different degrees of freedom were used to examine the hydration of Li+: (a) a polarizable and flexible molecule with constraints that account for the quantal nature of the vibration, (b) a polarizable and classically flexible molecule, (c) a polarizable and rigid molecule, and finally (d) a nonpolarizable and rigid molecule. The goal was to determine how individual molecular properties affect the correct description of the hydration of ions by comparing the structural and thermodynamic predictions for the aqueous solution as made by the different models, which ranged from a very refined one to a simple effective potential. The length of the Monte Carlo runs was large enough to ensure convergence and provide statistically meaningful results; the four models attained good agreement with the experimental data available for the hydration of Li+, as well as with the results of the most refined simulations. A well-defined first hydration shell was found. It had four water molecules whose dipoles were not aligned to the electric field of the ion because of their hydrogen-bonding with water molecules in outer shells. In the case of the most refined water model, the results showed this pattern clearly. On the other hand, the rigid nonpolarizable version produced a slightly higher hydration number and an almost complete alignment of the dipoles to the ion's electric field. Moreover, a detailed analysis of a microscopic molecular model of hydration showed that the average intramolecular geometry of the water molecules in the first hydration shell was the same as the one for those in the bulk, whereas the electric field of the ion induced a dipole 0.2 D higher in the water molecules of the first hydration shell. The value of the bulk was recovered at the second shell, which explains the good performance of the simplest model. Thus, despite the differences found in the description of the first hydration shell between the polarizable and the nonpolarizable models, the major effect on the polarization of the water molecules resulted from the water-water interaction. C1 Ctr Invest & Estud Avanzados, Dept Fis Aplicada, Unidad Merida, Merida 97310, Yucatan, Mexico. Univ Autonoma Estado Morelos, Ctr Invest Quim, Cuernavaca 62210, Morelos, Mexico. Wabash Coll, Dept Chem, Crawfordsville, IN 47933 USA. Univ Nacl Autonoma Mexico, Ctr Ciencias Fis, Cuernavaca 62251, Morelos, Mexico. RP Ortega-Blake, I, Ctr Invest & Estud Avanzados, Dept Fis Aplicada, Unidad Merida, Merida 97310, Yucatan, Mexico. 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Chem. Acc. PD MAR PY 2006 VL 115 IS 2-3 BP 177 EP 189 PG 13 SC Chemistry, Physical GA 020DF UT ISI:000235887500011 ER PT J AU Romero, RJ Basurto-Pensado, MA Jimenez-Heredia, AH Sanchez-Mondragon, JJ TI Working fluid concentration measurement in solar air conditioning systems SO SOLAR ENERGY LA English DT Article DE refractive index; solar air conditioning systems; lithium bromide; weight concentration; corrosive working fluids ID BROMIDE AB In order to evaluate on-line corrosive electrolyte concentration in solar air conditioning systems, an optical technique to determine the concentration is being proposed. With this optical sensing method, it is possible to measure the percentage concentration of the aqueous corrosive lithium bromide solution at temperatures ranging from 25 degrees C to 70 degrees C and a maximum concentration of 60%. The measurement system is based on the refractive index of the solution and the data correlation, at several temperature and concentration values. The results of this work present a direct method for concentration measurement of corrosive liquids and also show the correlation among the three parameters: refractive index, temperature and weight concentration. This correlation can be used to develop the optical device for solar air conditioning systems to control and improve efficiency. (c) 2005 Elsevier Ltd. All rights reserved. C1 Univ Autonoma Estado Morelos, Ctr Invest Ingn & Ciencias Aplicadas, Cuernavaca 62210, Morelos, Mexico. Inst Nacl Astrofis Opt & Elect, Dept Opt, Puebla 72000, Mexico. RP Romero, RJ, Univ Autonoma Estado Morelos, Ctr Invest Ingn & Ciencias Aplicadas, Av Univ 1001,Col Chamilpa, Cuernavaca 62210, Morelos, Mexico. EM rosenberg@uaem.mx CR BASURTOPENSADO MA, 2004, P 13 INT MAT RES C C, P14 CUEVASARTEAGA C, 2004, P 13 INT MAT RES C C, P5 HEROLD KE, 1991, INT J REFRIG, V14, P264 RIVERA W, 2000, SOL ENERGY, V69, P369 ROMERO RJ, 2000, SOL ENERG MAT SOL C, V63, P387 USBECK K, 1999, P 13 OPT FIB SENS C, P163 NR 6 TC 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0038-092X J9 SOLAR ENERG JI Sol. Energy PY 2006 VL 80 IS 2 BP 177 EP 181 PG 5 SC Energy & Fuels GA 016QJ UT ISI:000235634700007 ER PT J AU Martinez-Toledo, A Rios-Leal, E Vazquez-Duhalt, R Gonzalez-Chavez, MD Esparza-Garcia, JF Rodriguez-Vazquez, R TI Role of phenanthrene in rhamnolipid production by P-putida in different media SO ENVIRONMENTAL TECHNOLOGY LA English DT Article DE biosurfactants; rhamnose; fractional factorial experimental design; surface tension; fatty acids; P. putida; phenanthrene ID POLYCYCLIC AROMATIC-HYDROCARBONS; PSEUDOMONAS-AERUGINOSA; BIOSURFACTANT PRODUCTION; CONTINUOUS CULTURE; BIODEGRADATION; SURFACTANT; CARBON AB The role of phenanthrene in rhamnolipid production by P. putida in eight media with different culture conditions was investigated. Cultures using Fe2SO4.7H(2)0, KH2PO4, NH4Cl, yeast extract, glucose, and corn oil, with and without 200 mg l(-1) of phenanthrene, were evaluated under shaking for rhamnolipid production through a 2(7-4) fractional factorial experimental design. The biosurfactant production, decrease in the surface tension of the broth and the total cell growth in media without phenanthrene were affected significantly (p<0.001) by yeast extract, glucose, corn oil and NH4Cl, and in media with phenanthrene by glucose and yeast extract. The non polar fraction of the biosurfactant in all media was composed of linoleic (C18:2), arachidic (C20:0) and behenic (C22:0) fatty acids. The medium with phenanthrene (200 mg l(-1)), Fe2SO4.7H(2)0 (5x10(-4) g l(-1)), KH2PO4 (0.2g l(-1)), glucose (50 g l(-1)), yeast extract (1 g l(-1)), corn oil (2% vol), and NH4Cl (1 g l(-1)), shaken at 150 rpm at 37 degrees C, and pH 7.0, presented the highest biosurfactant production. For this medium the surface tension decreased by 35.9 mN m(-1) in relation to the initial value, and only this medium showed an emulsion capacity of 20%. The polar fraction (Rhamnose) in media 1, 3, 7 and 8 with phenanthrene was c.a 100%, in contrast to those without phenanthrene where this fraction was undetectable. C1 IPN, Ctr Invest & Estudios Avanzados, Mexico City 07360, DF, Mexico. UNAM, Inst Biotecnol, Cuernavaca 62270, Morelos, Mexico. Univ Nacl Autonoma Mexico, Inst Biotecnol, Cuernavaca 62210, Morelos, Mexico. Colegio Posgrad, Inst Recursos Nat, Dept Edafol, Montecillos, Edo De Mexico, Mexico. RP Rodriguez-Vazquez, R, IPN, Ctr Invest & Estudios Avanzados, Av IPN 2508,Col San Pedro Zacatenco, Mexico City 07360, DF, Mexico. CR DESING EXPERT 6 TRIA AMBRAMOWICZ DA, 1990, CRIT REV BIOTECHNOL, V10, P241 AMEZCUAVEGA C, IN PRESS BIORES TECH ATLAS R, 1998, MICROBIAL ECOLOGY FU, P414 CHAYABUTRA C, 2001, BIOTECHNOL BIOENG, V72, P25 CHAYABUTRA C, 2001, BIOTECHNOL PROGR, V17, P419 COOPER DG, 1987, APPL ENVIRON MICROB, V53, P224 CUNY P, 1999, LETT APPL MICROBIOL, V29, P242 EDWARDS DA, 1991, ENVIRON SCI TECHNOL, V25, P127 FOX SL, 2000, BIORESOURCE TECHNOL, V75, P325 GUERRASANTOS L, 1984, APPL ENVIRON MICROB, V48, P301 GUERRASANTOS LH, 1986, APPL MICROBIOL BIOT, V24, P443 HAMMARSTRAND K, 1966, GAS CHROMATOGRAPHIC, P1 JAIN DK, 1992, J IND MICROBIOL, V10, P87 MAIER RM, 2000, APPL MICROBIOL BIOT, V54, P625 MAKKAR RS, 2002, APPL MICROBIOL BIOT, V58, P428 MONTGOMERY DC, 2003, DESIGN ANAL EXPT, P458 MULLIGAN CN, 1989, J BIOTECHNOL, V12, P199 PERALES ER, 2002, CURR OPIN MICROBIOL, V5, P266 PIRCE AE, 1968, LCCCN6856442 PRIC CH, P259 RODRIGUEZVAZQUE.R, 2003, 4 C INT MICR AMB 2 S ROSENBERG E, 1999, APPL MICROBIOL BIOT, V52, P154 SAMANTA SK, 2002, TRENDS BIOTECHNOL, V20, P243 SMITH JA, 1997, ENVIRON SCI TECHNOL, V31, P3565 TULEVA BK, 2002, Z NATURFORSCH C, V57, P356 WALKER AW, 2002, BIOTECHNOL BIOENG, V78, P715 WILLUMSEN PA, 1997, BIODEGRADATION, V7, P415 ZHANG YM, 1997, ENVIRON SCI TECHNOL, V31, P2211 NR 28 TC 0 PU SELPER LTD, PUBLICATIONS DIV PI LONDON PA 79 RUSTHALL AVENUE, LONDON W4 1BN, ENGLAND SN 0959-3330 J9 ENVIRON TECHNOL JI Environ. Technol. PD FEB PY 2006 VL 27 IS 2 BP 137 EP 142 PG 6 SC Environmental Sciences GA 013JC UT ISI:000235404600003 ER PT J AU Sandoval-Jabalera, R Arias-Del Campo, E Chacon-Nava, JG Malo-Tamayo, JM Mora-Mendoza, JL Martinez-Villafane, A TI Corrosion behavior of engineering alloys in synthetic wastewater SO JOURNAL OF MATERIALS ENGINEERING AND PERFORMANCE LA English DT Article DE carbon steel; corrosion behavior; electrochemical techniques; stainless steels; synthetic wastewater ID POLARIZATION CURVES; ELECTROCHEMICAL NOISE; OHMIC DROP; IMPEDANCE; RESISTANCE; ALUMINUM; RATES AB The corrosion behavior of 1018, 410, and 800 steels exposed to synthetic wastewater have been studied using linear polarization resistance, cyclic potentiodynamic curves (CPCs), electrochemical noise (EN), and electrochemical impedance spectroscopy (EIS) tests. The conditions were: a biochemical oxygen demand of 776 ppm; a chemical oxygen demand of 1293 ppm; a pH of 8; and a cell temperature of 25 degrees C. From the CPC and EN results, no localized corrosion was found for the stainless steels. However, small indications of a possible localized corrosion process were detected for the 1018 steel. The EIS results revealed that different corrosion mechanisms occurred in the carbon steel compared with the stainless steels. The results show that the corrosion mechanism strongly depends on the type of steel. Overall, the 1018 steel exhibited the highest corrosion rate, followed by the 410 alloy. The highest corrosion resistance was achieved by the 800 alloy. In addition, scanning electron microscopy analyses were carried out to explain the experimental findings. C1 Ctr Adv Mat Res, Div Mat Deteriorat & Struct Integr, Chihuahua 31109, Mexico. Elect Res Inst, Mech Syst Div, Cuernavaca 62490, Morelos, Mexico. Petr Mexicanos, Pemex Gas Petroquim Basica, Mexico City 11311, DF, Mexico. RP Sandoval-Jabalera, R, Ctr Adv Mat Res, Div Mat Deteriorat & Struct Integr, Miguel de Cervantes 120,Complejo Ind, Chihuahua 31109, Mexico. EM raul.sandoval@cimav.edu.mx CR *ASTM, 1998, ANN BOOK ASTM STAND, P340 ABALLE A, 2001, CORROSION, V57, P35 AGARWAL P, 1993, CORROSION, V49, P278 BERTOCCI U, 2000, CORROSION, V56, P675 COTTIS RA, 2001, CORROSION, V57, P265 DOMINGUES L, 2002, ELECTROCHIM ACTA, V47, P2253 EDEN DA, 2001, CORR 2001 HOUST TX N GABRIELLI C, 1992, CORROSION, V48, P794 GEBLER SH, 2002, MATER PERFORMANCE, V41, P32 GONZALEZNUNEZ MA, 2003, CORR SCI 21 CENT MAN HLADKY K, 1980, BR CORROS J, V15, P20 IVERSEN A, 2001, BRIT CORROS J, V36, P277 KEARNS JR, 1996, ASTM STP, V1277, P446 KORSHIN GV, 2000, CORROS SCI, V42, P53 MACDONALD DD, 1990, CORROSION, V46, P229 MICKALONIS J, 1996, ASTM STP, V1277, P210 PEARSON BR, 1991, CORROS SCI, V32, P387 PESIC B, 2001, CORR 2001 HOUST TX N PICKERING HW, 1983, CORROS SCI, V23, P1107 POULSON B, 1983, CORROS SCI, V23, P391 ROCCHINI G, 1993, CORROS SCI, V34, P2019 ROCCHINI G, 1996, CORROS SCI, V38, P2095 ROCCHINI G, 1996, CORROS SCI, V38, P655 ROTHWELL AN, CORR 92 NACE 1992 HO SCULLY JR, 1993, STP, V1188 SCULLY JR, 2000, CORROSION, V56, P199 SIEBERT OW, 1986, ELECTROCHEMICAL TECH, P81 STEARN M, 1957, ELECTROCHEMICAL POLA, V104, P56 TAN YJ, 1996, CORROS SCI, V38, P1681 TATOR KB, 2003, MATER PERFORMANCE, V42, P32 TUTHILL AH, 1995, NIDI TECHNICAL SERIE URUCHURTU JC, 1987, CORROSION, V43, P19 URUCHURTUCHAVAR.J, 1997, RES TRENDS, V2, P49 WEBSTER S, 1992, CORR 92 MANCH UK NR 34 TC 0 PU ASM INTERNATIONAL PI MATERIALS PARK PA SUBSCRIPTIONS SPECIALIST CUSTOMER SERVICE, MATERIALS PARK, OH 44073-0002 USA SN 1059-9495 J9 J MATER ENG PERFORM JI J. Mater. Eng. Perform. PD FEB PY 2006 VL 15 IS 1 BP 53 EP 58 PG 6 SC Materials Science, Multidisciplinary GA 010HD UT ISI:000235177300010 ER PT J AU Navarrete, A Avula, B Joshi, VC Ji, XH Hersh, P Khan, IA TI Quantitative determination of triterpenes from Amphiptherygium adstringens by liquid chromatography and morphological analysis of cuachalalate preparations SO JOURNAL OF AOAC INTERNATIONAL LA English DT Article ID AMPHIPTERYGIUM-ADSTRINGENS; STEM BARK; PHENOLS; ACID AB Amphiptherygium adstringens (Anacardiaceae/Julianaceae), local name '' cuachalalate,'' is used in folk medicine for the treatment of cholelithiasis, fevers, fresh wounds, hypercholesterolemia, gastritis, gastric ulcers, and cancer of the gastrointestinal tract. The development of column high-performance liquid chromatography-photodiode array detector (LC-PDA) and high-performance thin-layer chromatography (HPTLC)-densitometry methods for the determination of masticadienonic acid and 3-hydroxymasticadienonic acid in cuachalalate preparations is described in this paper. Good separation of the compounds could be achieved by both methods. Either might be preparable depending on the requirements. The LC separation was performed on a Phenomenex Synergi MAX-RP 80A reversed-phase column operated at 40 degrees C with detection at 215 nm. The plant materials were extracted with methanol by sonication. The triterpenes present in the plant material and commercial extracts were separated with an acetonitrile-water reagent alcohol isocratic system. The limit of detection was 0.1-0.2 mu g/mL. The relative standard deviation values for the determination of triterpenes in plant extracts were less than 1.00%. This is the first report of an analytical method developed for the quantitative analysis of triterpenes from Amphiptherygium adstringens by LC-PDA and HPTLC. The stem bark showed higher amounts of triterpenes, and low amounts in root and stem root. The microscopic description of the crude drug of cuachalalate was also provided. C1 Univ Mississippi, Natl Ctr Nat Prod Res, Res Inst Pharmaceut Sci, University, MS 38677 USA. Inst Nacl Antropol & Hist, Delegac Morelos, Cuernavaca 62440, Morelos, Mexico. Univ Mississippi, Sch Pharm, Dept Pharmacognosy, Natl Ctr Nat Prod Res,Res Inst Pharmaceut Sci, University, MS 38677 USA. RP Navarrete, A, Natl Autonomous Univ Mexico, Fac Quim, Dept Farm, Ciudad Univ, Mexico City 04510, DF, Mexico. EM anavarrt@servidor.unam.mx CR *COM PERM FARM EST, 2001, FARM HERB EST UN MEX, P12 ABOURASHED EA, 2003, PHYTOTHER RES, V17, P657 AGUILARORTIGOZA CJ, 2003, ECON BOT, V57, P354 ARRIETA J, 2003, PLANTA MED, V69, P905 DOMINGUEZ X, 1983, REV LATINOAM QUIM, V14, P99 FAHN AF, 1974, AM J BOT, V16, P1 KUBO J, 1999, J AGR FOOD CHEM, V47, P533 LOGAN BK, 1994, ANAL CHIM ACTA, V288, P111 MAKINO M, 2004, PHYTOCHEMISTRY, V65, P891 MATA R, 1991, J ETHNOPHARMACOL, V34, P147 MATA R, 1993, PHYTOCHEMICAL POTENT, P41 NAVARRETE A, 1989, PLANTA MED, V55, P579 NAVARRETE A, 1990, REV MEX CIENC FARM, V21, P28 NAVARRETE A, 1998, PHYTOTHER RES, V12, P1 OLIVERA AG, 1999, J ETHNOPHARMACOL, V68, P109 OVIEDOCHAVEZ I, 2004, PHYTOMEDICINE, V11, P436 PEREZ R, 1993, INT J PHARMACOGN, V31, P185 SATOH M, 2001, CHEM PHARM BULL, V49, P18 SORIANOGARCIA M, 1987, ACTA CRYSTALLOGR C, V43, P990 STERN WL, 1952, AM J BOT, V39, P220 WATSON WH, 1987, REV LATINOAM QUIM, V18, P89 YOUNG DA, 1976, SYST BOT, V1, P149 NR 22 TC 0 PU AOAC INTERNATIONAL PI GAITHERSBURG PA 481 NORTH FREDRICK AVE, STE 500, GAITHERSBURG, MD 20877-2504 USA SN 1060-3271 J9 J AOAC INT JI J. AOAC Int. PD JAN-FEB PY 2006 VL 89 IS 1 BP 1 EP 7 PG 7 SC Chemistry, Analytical; Food Science & Technology GA 010GJ UT ISI:000235175000004 ER PT J AU Albiter, A Contreras, A Salazar, M Gonzalez-Rodriguez, JG TI Corrosion behaviour of aluminium metal matrix composites reinforced with TiC processed by pressureless melt infiltration SO JOURNAL OF APPLIED ELECTROCHEMISTRY LA English DT Article DE Al-2024 alloy; composites; corrosion; infiltration; TiC ID AL; WETTABILITY; MG; ALLOYS AB The corrosion resistance of commercial aluminium alloy (2024) and binary Al-Cu (x) and Al-Mg (x) alloys reinforced with TiC particles using a pressureless infiltration method has been evaluated in 3.5% NaCl solution using potentiodynamic polarization curves and linear polarization resistance measurements. The TiC preforms were sintered at 1250, 1350 and 1450 degrees C and infiltrated in the range of 900-1200 degrees C under argon atmosphere. Some specimens were heat treated at 530 degrees C for 150 min, water quenched and subsequently artificially aged at 190 degrees C for 12 h in an argon atmosphere and naturally aged at room temperature for 96 h, respectively. The corrosion resistance of the composites was evaluated as a function of the addition of Cu and Mg into the aluminium. In all cases pitting corrosion was observed with or without additions of Cu or Mg, but these elements increased the anodic corrosion current. However, it was found that addition of TiC particles in the composite without heat treatment reduced the anodic current density and the number and size of pits in the Al-2024 alloy. When the heat treatment was applied to the composite, either artificially or naturally aged, the anodic current density of the Al-2024 alloy increased. C1 Inst Mexicano Petr, Mexico City 07730, DF, Mexico. UAEM, CIICAP, Cuernavaca 6225, Morelos, Mexico. RP Albiter, A, Inst Mexicano Petr, Eje Cent Lazaro Cardenas 152, Mexico City 07730, DF, Mexico. EM aalbiter@imp.mx CR *NACE, MARC POURB ATL EL EQ, P168 ALBITER A, 2003, COMPOS PART A-APPL S, V34, P17 CONTRERAS A, 2003, SCRIPTA MATER, V48, P1625 CONTRERAS A, 2004, ACTA MATER, V52, P985 CONTRERAS A, 2004, J PHYS-CONDENS MAT, V16, S2241 CONTRERAS A, 2004, SCRIPTA MATER, V51, P249 DEUIS RL, 1997, CORROSION, V53, P880 HIHARA LH, 1992, CORROSION, V48, P546 KIOURTSIDIS G, 1998, MAT SCI ENG A-STRUCT, V248, P165 LEON CA, 2002, J MATER SCI, V37, P3509 MODI OP, 1992, J MATER SCI, V27, P3897 MUSCAT D, 1992, MATER SCI TECH SER, V8, P971 NATH D, 1989, CORROS SCI, V29, P1215 NUNES PCR, 1995, CORROSION, V51, P610 PACIEJ RC, 1988, CORROSION, V44, P680 SHIMIZU Y, 1995, MAT SCI ENG A-STRUCT, V198, P113 STEARN M, 1958, J ELECTROCHEM SOC, V105, P638 SUN H, 1991, CORROSION, V47, P741 TRZASKOMA PP, 1990, CORROSION, V46, P402 WRINKLER SL, 2004, CORROS SCI, V46, P893 YAO HY, 1998, CORROSION, V54, P499 NR 21 TC 0 PU SPRINGER PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0021-891X J9 J APPL ELECTROCHEM JI J. Appl. Electrochem. PD MAR PY 2006 VL 36 IS 3 BP 303 EP 308 PG 6 SC Electrochemistry GA 009MH UT ISI:000235115600005 ER PT J AU Flores-Palacios, A Garcia-Franco, JG TI The relationship between tree size and epiphyte species richness: testing four different hypotheses SO JOURNAL OF BIOGEOGRAPHY LA English DT Article DE community saturation; diversity; Mexico; montane forest; species-area relationship; Veracruz; vertical stratification ID SPATIAL-DISTRIBUTION; VASCULAR EPIPHYTES; CLOUD FOREST; AREA RELATIONSHIP; CENTRAL VERACRUZ; RAIN-FOREST; COMMUNITIES; DIVERSITY; BIOGEOGRAPHY; VEGETATION AB Aim For epiphytic plants trees are habitat units, and tree size determines epiphyte species richness. While growing, trees generate vertical microhabitats that are exploited by epiphytes. One would expect to find four different types of relationship between tree size and epiphyte species richness: positive linear (young trees), neutral (old trees), negative (old decaying trees) and positive asymptotic (trees of mixed size class in a mature forest). We tested these relationships in plots of colonizing sweetgum trees in pastureland, isolated remnant trees in pastureland (old oaks) and sweetgum and oaks in a pristine forest. Location The study was carried out in a landscape shaped by the fragmentation of lower montane cloud forest in San Andres Tlalnelhuayocan (19 degrees 30'56 ''' N and 96 degrees 59'50 '' W; 1500-1600 m a.s.l.) in central Veracruz, Mexico. Methods We measured the d.b.h. of all oaks and sweetgum trees (d.b.h. >= 5 cm) present in pastureland and in three 100 m(2) plots of a lower montane cloud forest. All trees were climbed and species richness of the epiphytes recorded. Results As expected, colonizer trees in pastureland showed a linear positive relationship. Although we found evidence that remnant oaks in pastureland had a neutral relationship between tree size and epiphyte species richness, the low power of the test did not allow us to make conclusions about the kind of relationship. Mixed size-class pristine forest trees showed a positive linear relationship between tree size and epiphyte species richness instead of a positive asymptotic one. Main conclusions Our results suggest that in the study area epiphyte communities are unsaturated, as the number of species increases with tree size and does not reach a ceiling. This evidence supports the idea that the species-area relationship is not asymptotic. However, the epiphyte community on remnant pastureland oaks may be saturated as epiphyte species richness did not increase with tree size, but a larger sample size is needed to confirm the neutral pattern. Neutral, asymptotic and negative patterns in the relationship between tree size and epiphyte species richness depend on the saturation of the trees by epiphytes. Other studies have suggested tree saturation, but further research is necessary in order to confirm or rule out these patterns. C1 Univ Autonoma Estado Morelos, CEAMISH, Cuernavaca 62209, Morelos, Mexico. Inst Ecol AC, Dept Ecol Func, Xalapa, Veracruz, Mexico. RP Flores-Palacios, A, Univ Autonoma Estado Morelos, CEAMISH, Av Univ 1001, Cuernavaca 62209, Morelos, Mexico. EM alejandro.florez@uaem.mx CR ARRENIUS O, 1921, J ECOL, V9, P95 BARTOLI CG, 1993, FOREST ECOL MANAG, V59, P289 BENNETT BC, 1987, B TORREY BOT CLUB, V114, P265 BENZING D, 1978, SELBYANA, V2, P133 CALDIZ DO, 1995, INT J ECOLOGY ENV SC, V21, P177 CATLING PM, 1989, BIOTROPICA, V21, P35 CONNOR EF, 1979, AM NAT, V113, P791 CORDOBA J, 2001, LIFE FORMS DYNAMICS, P79 DUNN RR, 2000, SELBYANA, V21, P137 FLORESPALACIOS A, 2001, SELBYANA, V22, P181 FLORESPALACIOS A, 2003, THESIS I ECOLOGIA AC FLORESPALACIOS A, 2004, PLANT ECOL, V173, P259 FOX E, 1994, SIGMASTAT 1 0 USERS FREIBERG M, 1996, BIOTROPICA, V28, P345 FREIBERG M, 1999, ECOTROPICA, V5, P75 GENTRY AH, 1987, ANN MO BOT GARD, V74, P205 HIETZ P, 1995, J VEG SCI, V6, P487 HIETZ P, 1995, J VEG SCI, V6, P719 HIETZ P, 1996, ECOTROPICA, V2, P59 INGRAM SW, 1995, FOREST CANOPIES, P587 JEPSON J, 1998, TREE CLIMBERS COMPAN KELLY DL, 1994, J BIOGEOGR, V21, P421 KIKUCHI T, 1992, ECOL REV, V22, P121 KOCH GW, 2004, NATURE, V428, P851 KRESS WJ, 1986, SELBYANA, V9, P2 LENNON JJ, 2001, J ANIM ECOL, V70, P966 LOREAU M, 2000, ECOL LETT, V3, P73 LYONS B, 2000, CAN J BOT, V78, P957 MACARTHUR RH, 1967, THEORY ISLAND BIOGEO MADISON M, 1979, SELBYANA, V5, P207 MUELLERDOMBOIS D, 1974, AIMS METHODS VEGETAT PEDRAZA RA, 2003, THESIS I ECOLOGIA AC RUCHTY A, 2001, BRYOLOGIST, V104, P274 RUDOLPH D, 1998, SELBYANA, V19, P27 SHAW JD, 1997, SELBYANA, V18, P195 SHAW JD, 2004, FOREST CANOPIES, P73 SIMBERLOFF D, 1984, BIOL CONSERV, V29, P27 SIMBERLOFF D, 1992, TROPICAL DEFORESTATI, P75 SOUTHWOOD TRE, 1983, OIKOS, V41, P359 THOMAS SC, 1996, AM J BOT, V83, P556 VALDIVIA PE, 1977, BIOTICA, V2, P55 VANPELT R, 2004, FOREST SCI, V50, P326 WHITTAKER RH, 1972, TAXON, V21, P213 WILLIAMSLINERA G, 1996, MADERA BOSQUES, V2, P53 WILLIAMSLINERA G, 2002, BIODIVERS CONSERV, V11, P1825 WILLIAMSON M, 2001, J BIOGEOGR, V28, P827 YEATON RI, 1982, BIOTROPICA, V14, P137 ZAMORACRESCENCI.P, 1997, VEGETACION FLORA MUN ZAR JH, 1996, BIOSTATISTICAL ANAL ZOTZ G, 1999, J BIOGEOGR, V26, P761 ZOTZ G, 2003, J TROP ECOL 1, V19, P81 NR 51 TC 2 PU BLACKWELL PUBLISHING PI OXFORD PA 9600 GARSINGTON RD, OXFORD OX4 2DQ, OXON, ENGLAND SN 0305-0270 J9 J BIOGEOGR JI J. Biogeogr. PD FEB PY 2006 VL 33 IS 2 BP 323 EP 330 PG 8 SC Ecology; Geography, Physical GA 004GY UT ISI:000234741200012 ER PT J AU Suarez-Sandoval, DY Nair, MTS Nair, PK TI Photoconductive antimony sulfide-selenide thin films produced by heating a chemically deposited Se-Sb2S3 layer SO JOURNAL OF THE ELECTROCHEMICAL SOCIETY LA English DT Article ID BATH DEPOSITION; SB2S3; SE AB Photoconductive thin films of antimony sulfide-selenide have been obtained by heating thin films of Se-Sb2S3, deposited sequentially by the chemical bath method. Heating these layers in nitrogen results in films of a composite of Sb2Se3, Sb2S3, and Sb2SxSe3-x for temperatures up to 300 degrees C and in a complete solid solution of Sb-2(SxSe3-x) near 400 degrees C. Heating the layer at 150 degrees C for 15-24 h also leads to the formation of the solid solution. X-ray diffraction (XRD) studies have indicated the presence of the compounds and the solid solution in the respective films. X-ray fluorescence (XRF) analyses indicate loss of sulfur and selenium from the films, up to 25 and 45%, respectively, during the formation of the solid solution. For the Sb2SxSe3-x solid solution formed at 350 - 400 S C, x is estimated to be 1.5 (XRF)-1.8 (XRD). The composite film formed at 300 degrees C shows three distinctive bandgaps corresponding to Sb2S3 (1.8 eV), Sb2Se3 (0.9 eV), and Sb2SxSe3-x (1.29 eV), while the solid solution formed at 400 degrees C shows a bandgap of 1.2 eV and an absorption coefficient 10(5) cm(-1) in the visible region. The dark conductivity of the films is approximate to 10(-9) - 10(-8) Omega(-1) cm(-1), and the photoconductivity (300 W/m(2), tungsten-halogen) is 50 - 80 times higher in each case. (c) 2005 The Electrochemical Society. C1 Univ Nacl Autonoma Mexico, Ctr Invest & Energia, Dept Solar Energy Mat, Morelos 62580, Mexico. RP Suarez-Sandoval, DY, Univ Nacl Autonoma Mexico, Ctr Invest & Energia, Dept Solar Energy Mat, Morelos 62580, Mexico. EM mtsn@cie.unam.mx CR ALBERTS V, 2000, THIN SOLID FILMS, V361, P432 ARENAS OL, 1997, SEMICOND SCI TECH, V12, P1323 BINDU K, 2002, APPL SURF SCI, V191, P138 BINDU K, 2002, SEMICOND SCI TECH, V17, P270 BINDU K, 2003, SOL ENERG MAT SOL C, V79, P67 BINDU K, 2004, SEMICOND SCI TECH, V19, P1348 BINDU K, 2005, SEMICOND SCI TECH, V20, P496 DEHREHAY A, 1993, AIP C P, V306, P370 DESHMUKH LP, 1994, J ELECTROCHEM SOC, V141, P1779 GROZDANOV I, 1994, SEMICOND SCI TECH, V9, P1234 GUPTA A, 1998, SOL ENERG MAT SOL C, V53, P385 KITAEV GA, 1970, ZH PRIKL KHIM, V43, P169 MADELUNG O, 1992, SEMICONDUCTORS OTHER, P49 NAIR MTS, 1998, J ELECTROCHEM SOC, V145, P2113 RODRIGUEZLAZCANO Y, 2001, J CRYST GROWTH, V223, P399 RODRIGUEZLAZCANO Y, 2005, J ELECTROCHEM SOC, V152, G635 RODRIGUEZLAZCANO Y, 2005, THIN SOLID FILMS, V493, P77 SAVADOGO O, 1994, J PHYS D APPL PHYS, V27, P1070 SAVODOGO O, 1992, SOL ENERG MAT SOL C, V26, P117 SAVODOGO O, 1994, J ELECTORCHEM SOC, V141, P2871 NR 20 TC 3 PU ELECTROCHEMICAL SOC INC PI PENNINGTON PA 65 SOUTH MAIN STREET, PENNINGTON, NJ 08534 USA SN 0013-4651 J9 J ELECTROCHEM SOC JI J. Electrochem. Soc. PY 2006 VL 153 IS 2 BP C91 EP C96 PG 6 SC Electrochemistry; Materials Science, Coatings & Films GA 001NK UT ISI:000234543400042 ER PT J AU Alarcon, FB Fuentes, BE Martinez, H TI Absolute cross section measurements for dissociative capture of H-2(+) in Ar SO INTERNATIONAL JOURNAL OF MASS SPECTROMETRY LA English DT Article DE H-2(+); angular distribution; absolute cross section; collision induced dissociation; fragmentation mechanism; ion fragmentation energies ID ELECTRON-CAPTURE; ANGULAR-DISTRIBUTIONS; COLLISIONS AB Absolute differential and total cross sections for dissociative capture of H-2(+) in Ar to produce H-, at projectile energies between 1.0 and 5.0 keV and for scattering angles from -4 degrees to 4 degrees were measured. The absolute total cross sections (TCS) for the dissociative capture to produce H- are of the order of magnitude of 10(-17) cm(2) and our measurements appear to merge well with previous experimental results. The measured TCS are one order of magnitude lower than the dissociative capture for the formation of Ho atoms. The angular distributions of the H- fragment show a monotonic decrease in the differential cross sections with increasing angle and several interesting structures are observed, which give information on the production of H-, i.e., attributed to the predissociative states of H-2(+) interacting with the target and with the two electron capture to form the excited state H-2(-). (c) 2005 Elsevier B.V. All rights reserved. C1 Univ Nacl Autonoma Mexico, Ctr Ciencias Fis, Cuernavaca 62191, Morelos, Mexico. Univ Nacl Autonoma Mexico, Posgrado Ciencias Fis, Cuernavaca 62191, Morelos, Mexico. Univ Nacl Autonoma Mexico, Fac Ciencias, Cuernavaca 62191, Morelos, Mexico. RP Martinez, H, Univ Nacl Autonoma Mexico, Ctr Ciencias Fis, Apartado Postal 48-3, Cuernavaca 62191, Morelos, Mexico. EM hm@fis.unam.mx CR BRUIJN DP, 1984, CHEM PHYS, V85, P215 CISNEROS C, 1991, NUCL INSTRUM METH 1, V56, P285 FEDORENKO NV, 1959, SOV PHYS JETP, V36, P267 FUENTES BE, 1995, NUCL INSTRUM METH B, V95, P158 GORSE C, 1992, PURE APPL CHEM, V64, P691 JANEV RK, 1991, COMMENTS AT MOL PHYS, V26, P83 MARTINEZ H, 1989, NUCL INSTRUM METH 1, V40, P44 MARTINEZ H, 2004, PHYS REV A, V69 MCCALL BJ, 1999, ASTROPHYS J 1, V522, P338 PETERSON JR, 1984, PHYS REV A, V30, P2807 SHARP TE, 1971, ATOM DATA, V2, P119 SIDIS V, 1984, CHEM PHYS, V85, P201 SUZUKI Y, 1986, NUCL INSTRUM METH B, V16, P397 WATSON WD, 1973, APJ, V183, L17 YASUFUMI S, 1986, J PHYS SOC JPN, V55, P3037 NR 15 TC 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 1387-3806 J9 INT J MASS SPECTROM JI Int. J. Mass Spectrom. PD JAN 1 PY 2006 VL 248 IS 1-2 BP 21 EP 24 PG 4 SC Physics, Atomic, Molecular & Chemical; Spectroscopy GA 001GG UT ISI:000234521000004 ER PT J AU Martinez, H Yousif, FB TI Formation of O2+ in collisions between O+ ions and N-2 molecules SO INTERNATIONAL JOURNAL OF MASS SPECTROMETRY LA English DT Article DE electron loss; ion-molecule collisions; total cross section; angular distribution ID DOUBLY CHARGED IONS; IONIZATION; O-2(2+) AB We report measurements of the total and absolute differential electron loss cross sections of 2.0-5.0 keV O+ ions in collisions by N-2 target at scattering angles between -3.2 degrees <= Theta < 3.2 degrees in the laboratory frame. The behavior of the absolute differential cross sections display an expected decreasing behavior with increasing angle. The measured total electron loss cross section show a monotonically increasing behavior as a function of the incident kinetic energy and found to be within the order of magnitude between 10(-19) and 10(-21) cm(2). (c) 2005 Elsevier B.V.. All rights reserved. C1 Univ Autonoma Estado Morelos, Fac Ciencias, Cuernavaca 62210, Morelos, Mexico. Univ Nacl Autonoma Mexico, Ctr Ciencias Fis, Cuernavaca 62251, Morelos, Mexico. RP Yousif, FB, Univ Autonoma Estado Morelos, Fac Ciencias, Avenida Univ 1001, Cuernavaca 62210, Morelos, Mexico. EM fbyousif@servm.fc.uaem.mx CR CURTIS DM, 1985, INT J MASS SPECTROM, V63, P241 FERGUSON EE, 1979, GAS PHASE ION CHEM FOGEL M, 1957, SOV PHYS-TECH PHYS, V2, P902 FURUHASHI O, 2004, PHYS REV A, V70 HAMDAN M, 1989, CHEM PHYS LETT, V164, P413 ISHIMOTO M, 1986, J GEOPHYS RES, V91, P5793 LARSSON M, 1990, J PHYS B ATOM MOL PH, V23, P1175 LI X, 1997, J CHEM PHYS, V106, P1373 LINDSAY BG, 1998, PHYS REV A, V57, P331 LO HH, 1970, ATOM DATA, V1, P305 LUNA H, 2003, J GEOPHYS RES-PLANET, V108 MARTINEZ H, 2004, PHYS REV A, V69 MASSEY HSW, 1952, ELECTRON IONIC IMP, P450 MORAN TF, 1980, PHYS REV A, V21, P1051 PRASAD SS, 1975, J GEOPHYS RES, V80, P1360 PRICE SD, 1991, J PHYS B ATOM MOL PH, V24, P4379 RUTHERFORD JA, 1971, J CHEM PHYS, V55, P5622 SMITH D, 1980, TOP CURR CHEM, V89, P1 STEBBINGS RF, 1966, J GEOPHYS RES, V71, P771 NR 19 TC 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 1387-3806 J9 INT J MASS SPECTROM JI Int. J. Mass Spectrom. PD JAN 1 PY 2006 VL 248 IS 1-2 BP 25 EP 28 PG 4 SC Physics, Atomic, Molecular & Chemical; Spectroscopy GA 001GG UT ISI:000234521000005 ER PT J AU Pandarinath, K Torres-Alvarado, IS Pushparani, DE Verma, SP TI X-ray diffraction analysis of hydrothermal minerals from the Los Azufres geothermal system, Mexico SO INTERNATIONAL GEOLOGY REVIEW LA English DT Article ID CHLORITE TRANSITION; EL SALVADOR; FIELD; CLAY; PERMEABILITY; TEMPERATURE; EVOLUTION; WAIRAKEI; SMECTITE; ZEALAND AB Los Azufres is an active geothermal field located in the middle of the Mexican Volcanic Belt (MVB), a vast Miocene-Recent, E-W-oriented volcanic province spanning central Mexico. Three wells-Az-5, Az-28, and Az-31-from this geothermal field were selected to investigate the distribution, alteration sequence, and thermal stability of hydrothermal minerals. Maximum in situ measured temperatures are 280 degrees C at 1493 m 265 degrees C at 1700 in, and 288 degrees C at 1300 in depths ill Az-5, Az-28, and Az-31., respectively. The host rocks in these wells are dominantly andesite followed by dacite, rhyolite, and basalt. Rock cuttings from different depths were analyzed for clay and non-clay minerals by X-ray Diffraction (XRD) methods. Hydrothermal quartz, calcite, and pyrite, as well as other alteration mineral phases (e.g., chabazite and chlorite) that are difficult to identify by traditional petrography were identified and their abundances semi-quantitatively estimated by XRD. We show that these mineral data present a better perception of distribution trends of hydrothermal minerals in geothermal wells than the qualitative mineral identifications generally used for this purpose. Homogenization temperatures measured in fluid inclusions of hydrothermal minerals, in situ measured temperatures in the wells, and K+/H+ vs. Mg2+/(H+)(2) activity diagrams for the chemical characteristics of the present geothermal fluids were used to define the thermal regime and the resultant stability conditions of the clay minerals. Smectite, illite, and chlorite are present in the < 2 mu m size fraction. Gradual variations in relative abundances of clay minerals range from smectite dominant at shallow well depths to a combination of smectite, illite, and chlorite at intermediate depths, and to illite and chlorite in the deepest levels. Excellent crystallinity and lack of mixed-layered clay minerals support a model involving a discontinuous change from smectite to chlorite and/or illite, rather than that involving continuous mixed-layering of smectite-illite and/or smectite-chlorite. Mineralogical and fluid inclusion data suggest that mineral distribution trends documented for the Los Azufres geothermal system reflect the prevailing thermal regime. The mineral parageneses of the Los Azufres geothermal field are broadly comparable with those reported in other geothermal systems of the world. C1 UNAM, Ctr Invest Energia, Temixco 62580, Morelos, Mexico. Mangalore Univ, Mangalore 574199, India. RP Pandarinath, K, UNAM, Ctr Invest Energia, Priv Xochicalco S-No,Col Ctr,Apartado Postal 34, Temixco 62580, Morelos, Mexico. EM pk@cie.unam.mx CR ALVARADO IST, 1996, WASSER GESTEINS WE E, V2 BEAUFORT D, 1995, B CENT RECH EXPL, V19, P267 BETHKE C, 1992, GEOCHEMISTS WORKBENC BIRD DK, 1984, ECON GEOL, V79, P671 BIRD DK, 2004, REV MINERAL GEOCHEM, V56, P235 BISCAYE PE, 1965, GEOL SOC AM BULL, V76, P803 BROWNE PRL, 1978, ANN REV EARTH PLANET, V6, P229 BROWNE PRL, 1984, LECT GEOTHERMAL GEOL CATHELINEAU M, 1985, CONTRIB MINERAL PETR, V91, P235 CATHELINEAU M, 1985, GEOTHERMICS, V14, P49 CATHELINEAU M, 1988, CONTRIB MINERAL PETR, V100, P418 DOBSON PF, 1985, J VOLCANOL GEOTH RES, V25, P273 ELDERS WA, 1984, GEOTHERMICS, V13, P27 ESSENE EJ, 1995, CLAY CLAY MINER, V43, P540 GONZALEZPARTIDA E, 2000, J VOLCANOL GEOTH RES, V104, P277 GONZALEZPARTIDA E, 2005, APPL GEOCHEM, V20, P23 GUTIERREZ NA, 1982, J HYDROL, V56, P137 HARVEY C, 2000, P WORLD GEOTH C KYUS, P1201 HARVEY CC, 1991, CLAY CLAY MINER, V39, P614 HENLEY RW, 1984, REV EC GEOLOGY, V1, P1 HIRIART G, 2003, GEOTHERMICS, V32, P389 IZQUIERDO MG, 1988, UNPUB CARACTERIZACIO KEITH TEC, 1988, J GEOPHYS RES, V93, P10174 KRISTMANNSDOTTI.H, 1975, P 2 UN S DEV US GEOT, P441 KRISTMANNSDOTTI.H, 1978, NATURAL ZEOLITES OCC KRISTMANNSDOTTI.H, 1979, P 6 INT CLAY C, P359 PATRIER P, 1996, J VOLCANOL GEOTH RES, V72, P101 ROBINSON D, 1999, AM MINERAL, V84, P607 SCHIFFMAN P, 1995, J METAMORPH GEOL, V13, P487 SCHMIDT ST, 1997, GEOL SOC AM BULL, V109, P683 SENER M, 2000, J VOLCANOL GEOTH RES, V96, P215 SIMMONS SF, 1998, P WAT ROCK INT ROTT, V9, P691 STEINER A, 1968, CLAYS CLAY MINERALS, V16, P193 TORRESALVARADO IS, 2002, INT GEOL REV, V44, P639 VERMA MP, 1989, P 6 INT S WAT ROCK I, P723 VERMA SP, 2005, GEOCHEM J, V39, P141 NR 36 TC 1 PU V H WINSTON & SON INC PI PALM BEACH PA 360 SOUTH OCEAN BLVD, PH-B, PALM BEACH, FL 33480 USA SN 0020-6814 J9 INT GEOL REV JI Int. Geol. Rev. PD FEB PY 2006 VL 48 IS 2 BP 174 EP 190 PG 17 SC Geology GA 001QK UT ISI:000234551200004 ER PT J AU Martinez, H Fuentes, BE TI Absolute differential and total cross sections for N+ formation from the interaction of N-2(+) with He and Ar SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS LA English DT Article DE N-2(+); collision induced dissociation; differential cross sections; total cross section; fragmentation mechanism ID SELECTIVE ELECTRON-CAPTURE; ION-MOLECULE REACTIONS; CHARGE-TRANSFER; COLLISIONS; SINGLE; IMPACT; ATOMS; H-2; FRAGMENTATION; IONIZATION AB Differential and total cross sections for the production of N+ fragment formed by the collision of N-2(+) on He and Ar, at projectile energies between 1.0 and 5.0 keV and for scattering angles from -4 degrees to 4 degrees are reported. The replotting of the angular distributions in terms of the scaled variable V(0)theta(2) as a function of (1/V-0)(d sigma/d Omega), indicates the same scaling law is followed in all the study. The reduced differential cross sections show an overall increase of at least one order of magnitude and a monotonic decreasing behavior at all the collision energies studied in this work. The cross sections for the N-2(+)-He system are found to be in the range of 0.85-1.60 angstrom(2), while for the N-2(+)-Ar system are between 2.40 and 3.90 angstrom(2). Both measured total cross sections for N+ formation display a slowly increasing behavior as a function of the incident energy. The absolute cross sections for DE (sigma(DE)) and DI (sigma(DI)) were estimated. Both cross sections for the He and Ar targets show the same behavior, with those for the Ar target slightly higher than those for the He target, while the DE process for both targets is a factor of 1.86 higher than that for DI. The measurements reported here are not found in the literature and the increasing availability of the data on these systems may stimulate work in this direction. (c) 2005 Elsevier B.V. All rights reserved. C1 UNAM, Ctr Ciencias Fis, Cuernavaca 62251, Morelos, Mexico. Univ Nacl Autonoma Mexico, Fac Ciencias, Mexico City 04510, DF, Mexico. RP Fuentes, BE, UNAM, Ctr Ciencias Fis, Apartado Postal 48-3, Cuernavaca 62251, Morelos, Mexico. EM hm@fis.unam.mx befm@hp.fciencias.unam.mx CR BAHATI EM, 2001, J PHYS B-AT MOL OPT, V34, P2963 BEIJERS JPM, 1996, J PHYS B-AT MOL OPT, V29, P1397 BLIEK FW, 1998, PHYS REV A, V57, P221 CISNEROS C, 1976, PHYS REV A, V14, P88 CRANDALL DA, 1995, REV SCI INSTRUM, V46, P562 EHRICH M, 2002, PHYS REV A A, V65 EHRICH M, 2003, RADIAT PHYS CHEM, V68, P127 FANG Z, 1997, PHYS REV A, V55, P440 GROZDANOV TP, 1978, PHYS REV A, V17, P880 HASAN AT, 2003, INT J MOL SCI, V4, P284 HENRI G, 1988, J CHEM PHYS, V88, P6381 KANEYASU T, 2003, NUCL INSTRUM METH B, V205, P624 MANN R, 1981, J PHYS B ATOM MOL PH, V14, P1161 MARTINEZ H, 2001, PHYS REV A, V63 MARTINEZ H, 2002, INT J MASS SPECTROM, V218, P161 MELO WS, 1999, PHYS REV A, V60, P1124 MORAN TF, 1965, J CHEM PHYS, V42, P2391 NICOLAS C, 2003, J PHYS B-AT MOL OPT, V36, P2239 OLSON RE, 1976, PHYS REV A, V14, P579 REYES PG, 2001, J PHYS B-AT MOL OPT, V34, P1485 SIEGLAFF DR, 1999, PHYS REV A, V59, P3538 NR 21 TC 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-583X J9 NUCL INSTRUM METH PHYS RES B JI Nucl. Instrum. Methods Phys. Res. Sect. B-Beam Interact. Mater. Atoms PD DEC PY 2005 VL 241 IS 1-4 BP 459 EP 464 PG 6 SC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Atomic, Molecular & Chemical; Physics, Nuclear GA 997PX UT ISI:000234260000097 ER PT J AU Aguilar, JO Gomez-Daza, O Brito, A Nair, MTS Nair, PK TI Optical and mechanical characteristics of clear and solar control laminated glass using zinc sulphide and copper sulphide thin films SO SURFACE & COATINGS TECHNOLOGY LA English DT Article DE laminated glass; ZnS; CuS ID CHEMICAL BATH DEPOSITION; CONTROL COATINGS; CUXS; PERFORMANCE; ADHESION; BISMUTH AB Due to their structural integrity, laminated sheet glass is used in safety, security and transportation applications. In the simplest form, it is produced at temperature of 130-140 degrees C under a pressure of 10-16 kg/cm(2), applied to a glass-polyvinyl butyral (PVB)-glass sandwich for 30 min to a few hours. In this work, we report that the presence of a coating of ZnS thin film (40-80 nm) applied by chemical bath deposition on 2-mm-thick sheet glass improves the adhesion strength of laminated glass by about 20%, from 11.08 +/- 0.85 to 13.29 +/- 1.8 MPa. The optical transmittance of the laminated glass with ZnS thin film in the visible region is about 80%, essentially the same as that of the simple glass-PVB-glass laminate. The addition of a CuS thin film of 100-150 nm in thickness over the ZnS coating confers solar radiation control properties to the glass laminate: visible transmittance of 22% to 40% and very low transmittance, < 10%, in the near infrared region, with the adhesion strength maintained at 12-14 MPa, which is above that of glass-PVB-glass laminates. These results may be of interest toward developing architectural glazings for tropical hot climates, and which can withstand windstorms efficiently. (c) 2004 Elsevier B.V. All rights reserved. C1 Univ Nacl Autonoma Mexico, Dept Solar Energy Mat, Ctr Invest Energia, Temixco 62580, Morelos, Mexico. Inst Invest Elect, Temixco, Morelos, Mexico. RP Nair, PK, Univ Nacl Autonoma Mexico, Dept Solar Energy Mat, Ctr Invest Energia, Temixco 62580, Morelos, Mexico. EM joaa@cie.unam.mx pkn@cie.unam.mx CR *US DEP EN, 1998, DOEEE0173 ALVAREZ G, 2001, APPL THERM ENG, V21, P1813 ARENAS OL, 1997, SEMICOND SCI TECH, V12, P1323 ESTRADAGASCA CA, 1993, J PHYS D APPL PHYS, V26, P1304 GARCIA VM, 1999, J CRYST GROWTH, V203, P113 GOROKHOVSKY A, 2001, J NON-CRYST SOLIDS, V291, P43 HUNTSBERGER JR, 1981, J ADHESION, V13, P107 JAGOTA A, 2000, INT J FRACTURE, V104, P105 MURALIDHAR S, 2000, ACTA MATER, V48, P4577 NAIR MTS, 1989, SEMICOND SCI TECH, V4, P599 NAIR MTS, 1997, P SOC PHOTO-OPT INS, V3138, P186 NAIR PK, 1989, J PHYS D APPL PHYS, V22, P829 NAIR PK, 1991, J PHYS D APPL PHYS, V24, P441 NAIR PK, 1992, SEMICOND SCI TECH, V7, P239 NAIR PK, 1993, J ELECTROCHEM SOC, V140, P1085 SAUNDERS KJ, 1973, ORGANIC POLYM CHEM NR 16 TC 0 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0257-8972 J9 SURF COAT TECH JI Surf. Coat. Technol. PD DEC 21 PY 2005 VL 200 IS 7 BP 2557 EP 2565 PG 9 SC Materials Science, Coatings & Films; Physics, Applied GA 995JO UT ISI:000234096800071 ER PT J AU Aguirre-Cruz, A Mendez-Montealvo, G Solorza-Feria, J Bello-Perez, LA TI Effect of carboxymethylcellulose and xanthan gum on the thermal, functional and rheological properties of dried nixtamalised maize masa SO CARBOHYDRATE POLYMERS LA English DT Article DE dried masa; nixtamalisation; carboxymethylcellulose; xanthan gum; thermal analysis; rheology; Zea mays ID TORTILLA PRODUCTION; STARCH PASTES; CORN FLOUR; HYDROCOLLOIDS; GELATINIZATION; RETROGRADATION; AMYLOPECTIN; SUSPENSIONS; STABILITY; BEHAVIOR AB Maize masa was mixed with carboxymethylcellulose (CMC) and xanthan gum at 0.2 and 0.5% (w/w) solids and then freeze-dried for obtaining dried masa (DM) samples which were tested for chemical composition, thermal analysis, water retention capacity (WRC), solubility and rheological properties. The thermal properties of dried masa with hydrocolloids (DMH), showed a transition temperature higher than DM but lower enthalpies, in an interval between 80.5-81.6 degrees C and 5.4-11.4 J/g, respectively. Masa samples with hydrocolloids stored for 7 and 14 days, showed similar values of transition temperatures but different enthalpy values, being usually lower than that of the control. The WRC and the solubility of the DMH, were higher than those of the control. The addition of hydrocolloids to DM increased the viscosity expressed in Brabender Unities. All masa samples behaved as 'weak' viscoelastic gels, with G' (elastic modulus)> G" (viscous modulus), when subjected to a three stages of heating-cooking-cooling kinetics, with an increase in the moduli values as, the kinetics progressed. Overall the hydrocolloids addition decreased both moduli values. (c) 2005 Elsevier Ltd. All rights reserved. C1 IPN, Ctr Desarrollo Prod Biot, Yautepec 62731, Morelos, Mexico. RP Solorza-Feria, J, IPN, Ctr Desarrollo Prod Biot, Km 8-5 Carr Yautepec-Jojutla Col San Isidro Apart, Yautepec 62731, Morelos, Mexico. 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Polym. PD DEC 1 PY 2005 VL 62 IS 3 BP 222 EP 231 PG 10 SC Chemistry, Applied; Chemistry, Organic; Polymer Science GA 995LS UT ISI:000234102400003 ER PT J AU De la Cruz-Cordero, R Hernandes-Nunez, E Fernandez-Zertuche, M Munoz-Hernandez, MA Ordonez, M TI Preparation of phosphostatine and phosphoepistatine from L-leucine via high diastereoselective reduction of 3-amino-2-ketophosphonates SO ARKIVOC LA English DT Article DE phosphostatine; phosphoepistatine; aminophosphonic acids; beta-ketophosphonates; diastereoselective reduction; statine analogues ID BETA-AMINO ALCOHOLS; N-BOC-STATINE; STEREOSELECTIVE-SYNTHESIS; UNSATURATED PHOSPHONATES; PROTEASE INHIBITORS; GAMMA-AMINO; ACIDS; ANALOGS; DERIVATIVES; KETONES AB The reduction of (3S)-N,N-dibenzylamino-2-ketophosphonate 5 derived from L-leucine with catecholborane at -20 degrees C afford the (3S)-N, N-dibenzylamino-(2R)-hydroxyphosphonate syn-6, whereas the reduction of (3S)-N-benzylamino-2-ketophosphonate 9 with Zn(BH4)(2) at -78 degrees C gave the (3S)-N-benzylamino-(2S)-hydroxyphosphonate anti-10. The reduction in both cases was in good chemical yields and high diastereoselectivity. The hydrolysis and hydrogenolysis of syn-6 and anti-10 gave phosphostatine 12 and phosphoepistatine 13, respectively. C1 Univ Auton Estado Morelos, Ctr Invest Quim, Cuernavaca 62210, Morelos, Mexico. RP Ordonez, M, Univ Auton Estado Morelos, Ctr Invest Quim, Av Univ 1001, Cuernavaca 62210, Morelos, Mexico. 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A high-resolution NMR solution structure of pin1 showed that the two distinct alpha-helical regions move around the central hinge region, which contains Pro(19). P-31 NMR spectra of lipid membrane in the presence of pin1, at various temperatures, showed that pin1 induces various lipid phase behaviors depending on the acyl chain length and charge of phospholipids. Notably, it was found that pin1 induced formation of the cubic phase in shorter lipid membranes above T-m. Further, the 13 C NMR spectra of pin1 labeled at Leu(28) under magic angle spinning (MAS) indicated that the motion of pin1 bound to the lipid bilayer was very slow, with a correlation time of the order of 10(-3) s. P-31 NMRspectra of dispersions of four saturated phosphatidyl-cholines in the presence of three types of pin1 derivatives, [W4A, W6A, W15A]-pin1, pin1(1- 18), and pin1(20- 44), at various temperatures demonstrated that all three pin1 derivatives have a reduced ability to trigger the cubic phase. 13 C chemical shift values for pin1(1- 18) labeled at Val(3), Ala(10), or Ala(11) under static or slow MAS conditions indicate that pin1( 1- 18) rapidly rotates around the average helical axis, and the helical rods are inclined at similar to 30 degrees to the lipid long axis. C-13 chemical shift values for pin1(20-44) labeled at Gly(25), Leu(28), or Ala(31) under static conditions indicate that pin1( 20- 44) may be isotropically tumbling. 1 H MAS chemical shift measurements suggest that pin1 is located at the membrane-water interface approximately parallel to the bilayer surface. Solid-state NMR results correlated well with the observed biological activity of pin1 in red blood cells and bacteria. C1 Suntory Inst Bioorgan Res, Osaka 6188503, Japan. CNRS, UMR 6098, AFMB, F-13402 Marseille, France. Univ Aix Marseille 1, F-13402 Marseille, France. Univ Aix Marseille 2, F-13402 Marseille, France. UNAM, Inst Biotechnol, Cuernavaca 62210, Morelos, Mexico. RP Nomura, K, Suntory Inst Bioorgan Res, Osaka 6188503, Japan. 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J. PD DEC PY 2005 VL 89 IS 6 BP 4067 EP 4080 PG 14 SC Biophysics GA 988JO UT ISI:000233590800044 ER PT J AU Renugopalakrishnan, V Garduno-Juarez, R Narasimhan, G Verma, CS Wei, X Li, PZ TI Rational design of thermally stable proteins: Relevance to bionanotechnology SO JOURNAL OF NANOSCIENCE AND NANOTECHNOLOGY LA English DT Review DE thermally stable protein; rational design; protein thermal stability; bacteriorhodopsin; rubredoxin; ferredoxin ID COLD SHOCK PROTEIN; OPTIMIZED ELECTROSTATIC SURFACES; TEMPERATURE-SENSITIVE MUTANTS; ENGINEERED DISULFIDE BONDS; AMINO-ACID-SEQUENCE; CRYSTAL-STRUCTURE; THERMOPHILIC PROTEINS; PYROCOCCUS-FURIOSUS; SALT BRIDGES; HYPERTHERMOPHILIC PROTEINS AB Design of thermally stable proteins is spurred by their applications in bionanotechnology. There are three major issues governing this: first, the upper limit on the temperature at which proteins remain physiologically active and are available for technological applications (answers may emerge from the discovery of new, natural hyperthermophilic enzymes that are active above 125 degrees C or from the selection of mutants of hyperthermophilic enzymes that are more stable); second, the use of hyperthermophilic enzymes as molecular templates to design highly stable enzymes that have high activity at low temperatures; third, the link between rigidity and flexibility to thermostability and activity, respectively. We review progress in these areas. C1 Harvard Univ, Childrens Hosp, Sch Med, Boston, MA 02115 USA. Univ Nacl Autonoma Mexico, Ctr Ciencias Fis, Cuernavaca 62210, Morelos, Mexico. Florida Int Univ, Sch Comp & Informat Sci, Bioinformat Res Grp, BioRG, Miami, FL 33199 USA. Bioinformat Inst, Singapore 138671, Singapore. Chinese Acad Sci, Shanghai Res Ctr Biotechnol, Shanghai 200233, Peoples R China. RP Renugopalakrishnan, V, Harvard Univ, Childrens Hosp, Sch Med, Boston, MA 02115 USA. 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Nanosci. Nanotechnol. PD NOV PY 2005 VL 5 IS 11 BP 1759 EP 1767 PG 9 SC Chemistry, Multidisciplinary; Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Physics, Applied; Physics, Condensed Matter GA 987RE UT ISI:000233534200001 ER PT J AU Gonzalez-Segura, L Velasco-Garcia, R Rudino-Pinera, E Mujica-Jimenez, C Munoz-Clares, RA TI Site-directed mutagenesis and homology modeling indicate an important role of cysteine 439 in the stability of betaine aldehyde dehydrogenase from Pseudomonas aeruginosa SO BIOCHIMIE LA English DT Article DE betaine aldehyde dehydrogenase; cysteine residues; homology modeling; site directed mutagenesis; protein stability; oligomeric state ID RETINAL SPECIFICITY; ANGSTROM RESOLUTION; CRYSTAL-STRUCTURE; PROTEIN; PURIFICATION; REACTIVITY; REVEALS; BINDING; PAO1 AB Betaine aldehyde dehydrogenase (BADH) from the human pathogen Pseudomonas aeruginosa is a tetrameric enzyme that contains a catalytic Cys286 and three additional cysteine residues, Cys353, 377, and 439, per subunit. In the present study, we have investigated the role of the three non-essentials in enzyme activity and stability by homology modeling and site-directed mutagenesis. Cys353 and Cys377 are located at the protein surface with their sulfur atoms buried, while Cys439 is at the subunit interface between the monomers forming a dimeric pair. All three residues were individually mutated to alanine and Cys439 also to serime and valine. The five mutant proteins were expressed in Escherichia coli and purified to homogeneity. Their steady-state kinetics was not significantly affected, neither was their structure as indicated by circular dicroism spectropolarimetry, protein intrinsic fluorescence, and size-exclusion chromatography. However, stability was severely reduced in the Cys439 mutants particularly in C439S and C439V, which were inactive when expressed at 37 degrees C. They also exhibited higher sensitivity to thermal and chemical inactivation, and higher propensity to dissociation by dilution or exposure to low ionic strength than the wild-type enzyme. Size-exclusion chromatography indicates that substitution of Cys439 lead to unstable dimers or to stable dimeric conformations not compatible with a stable tetrameric structure. To the best of our knowledge, this is the first study of an aldehyde dehydrogenase revealing a residue at the dimer interface involved in holding the dimer, and consequently the tetramer, together. (C) 2005 Elsevier SAS. All rights reserved. C1 Univ Nacl Autonoma Mexico, Fac Quim, Dept Bioquim, Mexico City 04510, DF, Mexico. FES Iztacala, Lab Osmorregulac, Tlalnepantla 54090, Edo Mexico, Mexico. Univ Nacl Autonoma Mexico, Inst Biotecnol, Dept Med Mol & Bioproc, Cuernavaca 62210, Morelos, Mexico. RP Munoz-Clares, RA, Univ Nacl Autonoma Mexico, Fac Quim, Dept Bioquim, Mexico City 04510, DF, Mexico. EM clares@servidor.unam.mx CR AHVAZI B, 2000, BIOCHEM J 3, V349, P853 BRADFORD MM, 1976, ANAL BIOCHEM, V72, P248 BRUNGER AT, 1998, ACTA CRYSTALLOGR D 5, V54, P905 COBESSI D, 1999, J MOL BIOL, V290, P161 GONZALEZSEGURA L, 2002, BIOCHEM J 3, V361, P577 GRUEZ A, 2004, J MOL BIOL, V343, P29 HANSON AD, 1985, P NATL ACAD SCI USA, V82, P3678 HE JJ, 1991, SCIENCE, V251, P1479 JOHANSSON K, 1998, PROTEIN SCI, V7, P2106 JONES TA, 1991, ACTA CRYSTALLOGR A, V47, P110 KILBOURN JP, 1978, LANCET, V1, P334 LAMB AL, 1999, BIOCHEMISTRY-US, V38, P6003 LIU ZJ, 1997, NAT STRUCT BIOL, V4, P317 MOORE SA, 1998, STRUCTURE, V6, P1541 NAGASAWA T, 1976, AGR BIOL CHEM TOKYO, V40, P1743 NI L, 1999, PROTEIN SCI, V8, P2784 NICHOLLS A, 1991, PROTEINS, V11, P281 PEPSIN SR, 1982, INVEST OPHTH VIS SCI, V22, P651 POLGAR L, 1975, EUR J BIOCHEM, V51, P63 ROSE GD, 1985, SCIENCE, V229, P834 SAGE AE, 1997, MOL MICROBIOL, V23, P43 SCHWEDE T, 2003, NUCLEIC ACIDS RES, V31, P3381 SINGH J, 1992, ATLAS PROTEIN SIDE C, V1 SINGH J, 1992, ATLAS PROTEIN SIDE C, V2 STEINMETZ CG, 1997, STRUCTURE, V5, P701 STOVER CK, 2000, NATURE, V406, P959 VALENZUELASOTO EM, 2003, CHEM-BIOL INTERACT, V143, P139 VELASCOGARCIA R, 1999, J BACTERIOL, V181, P1292 VELASCOGARCIA R, 2000, BIOCHEM J 3, V352, P675 WILKEN DR, 1970, BIOCHIM BIOPHYS ACTA, V216, P305 WRIGHT JR, 1987, AM REV RESPIR DIS, V136, P426 YANCEY PH, 1982, SCIENCE, V217, P1214 NR 32 TC 1 PU ELSEVIER FRANCE-EDITIONS SCIENTIFIQUES MEDICALES ELSEVIER PI PARIS PA 23 RUE LINOIS, 75724 PARIS, FRANCE SN 0300-9084 J9 BIOCHIMIE JI Biochimie PD DEC PY 2005 VL 87 IS 12 BP 1056 EP 1064 PG 9 SC Biochemistry & Molecular Biology GA 987KA UT ISI:000233515600003 ER PT J AU Rodas-Grapain, A Arenas-Alatorre, J Gomez-Cortes, A Diaz, G TI Catalytic properties of a CuO-CeO2 sorbent-catalyst for de-SOx reaction SO CATALYSIS TODAY LA English DT Article DE de-SOx; ceria; copper oxide; flue gas desulfurization; sulfur dioxide; surfactants ID CERIA-BASED CATALYSTS; TEMPERATURE CO OXIDATION; ELEMENTAL SULFUR; REDUCTION; OXIDE; TPD; DESULFURIZATION; BEHAVIOR; DIOXIDE; CU/CEO2 AB The preparation and characterization of a CuO-CeO2 sorbent-catalyst was performed by an inorganic/organic synthesis route and the materials were tested in de-SOx type reactions. The preparation of mesostructured CeO2 was made using hexadecylamine surfactant and cerium acetate as the inorganic precursor. This procedure was modified by inclusion of the CuO precursor during the synthesis. These sorbent-catalysts were characterized by transmission electronic microscopy (TEM), N-2 physisorption, X-ray diffraction (XRD) and temperature-programmed reduction (TPR). The adsorbent-catalysts were tested by means of sulfurization from room temperature to 760 degrees C using a combined SO2/N-2 gas mixture (3600 ppm) and the gain of weight was recorded in a thermo-balance. The materials prepared with those surfactants showed high surface area due to mesopores and small CuO particles dispersed on the ceria support. The catalytic performance in the de-SOx reaction was higher than conventional sorbent-catalysts prepared by impregnation of commercial ceria. The improved SO2 adsorption capacity of these materials is attributed to a better distribution and interaction of the copper species with the ceria support. (c) 2005 Elsevier B.V. All rights reserved. C1 UNAM, Inst Fis, Mexico City 01000, DF, Mexico. IIE, Cuernavaca 62490, Morelos, Mexico. RP Diaz, G, UNAM, Inst Fis, POB 20-364, Mexico City 01000, DF, Mexico. EM diaz@fisica.unam.mx CR BOARO M, 2001, TOP CATAL, V16, P299 FERRIZ RM, 2002, CATAL LETT, V82, P123 FLYTZANISTEPHANOPOULOS M, 2000, CATAL TODAY, V62, P145 GREEN DW, 1997, PERRYS CHEM ENG HDB, P2 HEDGES SW, 2002, INT J ENVIRON POLLUT, V17, P44 LI ZJ, 1997, IND ENG CHEM RES, V36, P187 LIU W, 1996, CATAL TODAY, V28, P391 LUO MF, 1997, APPL CATAL A-GEN, V162, P121 LYONS DM, 2002, J MATER CHEM, V12, P1207 OCONNELL M, 2000, CATAL TODAY, V59, P387 OVERBURY SH, 1999, J PHYS CHEM B, V103, P11308 RODAS A, 2004, INT S ADV HYDR OIL F RODRIGUEZ JA, 1999, CATAL LETT, V62, P113 SEDMAK G, 2003, J CATAL, V213, P135 TERRIBILE D, 1997, CHEM MATER, V9, P2676 TERRIBILE D, 1998, J CATAL, V178, P299 TROVARELLI A, 1999, CATAL TODAY, V50, P353 WANG JB, 2002, APPL CATAL A-GEN, V232, P107 WEN B, 2002, APPL CATAL B-ENVIRON, V37, P75 XIAOYUAN J, 2003, J MOL CATAL A-CHEM, V197, P193 ZENG Y, 2000, CHEM ENG SCI, V55, P4893 ZHANG SM, 2002, CATAL LETT, V80, P41 ZHU TL, 1999, APPL CATAL B-ENVIRON, V21, P103 NR 23 TC 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0920-5861 J9 CATAL TODAY JI Catal. Today PD OCT 30 PY 2005 VL 107-08 BP 168 EP 174 PG 7 SC Chemistry, Applied; Chemistry, Physical; Engineering, Chemical GA 984HM UT ISI:000233293600023 ER PT J AU Portugal, E Izquierdo, G Truesdell, A Alvarez, J TI The geochemistry and isotope hydrology of the Southern Mexicali Valley in the area of the Cerro Prieto, Baja California (Mexico) geothermal field SO JOURNAL OF HYDROLOGY LA English DT Article DE arid land; stable isotopes; hydrogeochemistry; Cerro Prieto; Mexico ID GROUNDWATER; SALINITY; WATER AB Groundwaters from the phreatic aquifer within and surrounding of the Cerro Prieto geothermal field were analyzed geochemically and isotopically in order to establish a hydrodynamic model of the study zone, which is located in the Mexicali Valley between 655,000-685,000 m E-W and 3,605,000-3,576,000 m N-S relative to UTM coordinates. Based on their chemical composition three types of water were recognized: chloride, sulfate and bicarbonate. However four groups of water were identified on a statistical multi-variable method of cluster analysis (A-D). The average temperature is 25 degrees C; with a few exceptions in the south where temperature can be as high as 47 degrees C. Stable isotope ratios for some waters plot close to the world meteoric line, corresponding to the original unaltered waters of the zone. The hydrogeochemistry varies in relation to three principal processes: evaporation, infiltration of water used in agriculture and rock interaction by reaction with evaporitic deposits. Major quartz, calcite and plagioclase and minor smectite, kaolinite, halite, sylvite and gypsum were identified by X-ray diffraction in lacustrine sediments of the central part of the zone. Chemical modeling indicates saturation with respect to calcite and undersaturation with respect to gypsum. By incorporating chemical and isotope data into geological and isopotential well information, a hydrodynamic model has been postulated. In this hydrodynamic model the water (A) enters the study zone from the east and it is originally of the old Colorado River water. The water samples on which the model is based were draw from agricultural wells that intersected two aquifers, a shallow and a deep one, representing the recharge to the zone. The salinity of the deep aquifer water (B) is lower than that of the shallow aquifer water (C) and so is the stable isotope ratio. The difference is though to be due to dissolution of evaporates, evaporation and possible infiltration of spent agriculture water. Both waters then pass through lacustrine sediments and gain in salinity and become isotopically heavier mainly by evaporation in a stagnate flow. They eventually emerge as a saline water (D) in the central part of the study zone. This saline water is the one that mixes with thermal fluid discharges from the geothermal reservoir in the south. (c) 2005 Elsevier B.V. All rights reserved. C1 Inst Invest Elect, Gerencia Geotermia, Cuernavaca 62490, Morelos, Mexico. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Earth Sci, Berkeley, CA 94720 USA. Comis Fed Elect, Mexico City, DF, Mexico. RP Portugal, E, Inst Invest Elect, Gerencia Geotermia, Reforma 113, Cuernavaca 62490, Morelos, Mexico. 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Hydrol. PD NOV 10 PY 2005 VL 313 IS 3-4 BP 132 EP 148 PG 17 SC Engineering, Civil; Geosciences, Multidisciplinary; Water Resources GA 979PL UT ISI:000232957200002 ER PT J AU Kotsarenko, A Molchanov, O Enriquez, RP Cruz-Abeyro, JAL Koshevaya, S Grimalsky, V Kremenetsky, I TI Possible seismogenic origin of changes in the ULF EM resonant structure observed at Teoloyucan geomagnetic station, Mexico, 1999-2001 SO NATURAL HAZARDS AND EARTH SYSTEM SCIENCES LA English DT Article AB The evolution of the ULF resonant structure observed at Teoloyucan geomagnetic station has been provisionally studied in a possible relation with seismic activity in Mexico in the period 1999-2001. Two resonant lines were observed in the H-component (linear polarization) in the frequency bands f(R2)=10.2-11.1 mHz and f(R2)=13.6-14.5 mHz, sometimes accompanied by other harmonics. The source of the observed resonances is possibly related with the geomagnetic location of the station (geomagnetic latitude lambda=29.1 degrees) and its proximity to the equatorial electrojet (lambda similar to 30 degrees). An enhancement of the carrier frequency of both resonances in the period 1 month-2 weeks was found before the strongest EQs. Also, a depression of the resonant structure just a few days before and a few days after some EQs seems to be correlated with seismic activity. C1 UNAM, Ctr Geociencias Juriquilla, Queretaro 76001, Mexico. Inst Phys Earth, Moscow, Russia. UAEM, Cuernavaca, Morelos, Mexico. INAOE, Puebla, Mexico. RP Kotsarenko, A, UNAM, Ctr Geociencias Juriquilla, Apdo Postal 1-742, Queretaro 76001, Mexico. EM kotsarenko@geociencias.unam.mx CR HATTORI K, 2004, PHYS CHEM EARTH, V29, P425 HAYAKAWA M, 2002, TERRA PUBL TOKYO, P353 KOPYTENKO Y, 2001, NAT HAZ EARTH SYST, V1, P23 KOTSARENKO A, 2004, NAT HAZARD EARTH SYS, V4, P679 MOLCHANOV OA, 2004, PHYS CHEM EARTH, V29, P649 PULINETS S, 2004, IONOSPHERIC PRECURSO PULINETS SA, 2004, GEOMAGN AERONOMY+, V44, P102 SOROKIN V, 2003, GEOPHYS RES, V5 SURKOV VV, 2003, J ATMOS SOL-TERR PHY, V65, P31 NR 9 TC 0 PU EUROPEAN GEOSCIENCES UNION PI KATLENBURG-LINDAU PA MAX-PLANCK-STR 13, 37191 KATLENBURG-LINDAU, GERMANY SN 1561-8633 J9 NAT HAZARDS EARTH SYST SCI JI Nat. Hazards Earth Syst. Sci. PY 2005 VL 5 IS 5 BP 711 EP 715 PG 5 SC Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences; Water Resources GA 978JN UT ISI:000232869500013 ER PT J AU Hinojosa, JF Cabanillas, RE Alvarez, G Estrada, CE TI Nusselt number for the natural convection and surface thermal radiation in a square tilted open cavity SO INTERNATIONAL COMMUNICATIONS IN HEAT AND MASS TRANSFER LA English DT Article DE convection; open cavity; Nusselt number ID BUOYANCY-DRIVEN FLOWS; SHALLOW OPEN CAVITIES; HEAT-TRANSFER; ENCLOSURES; BOUNDARIES; SIMULATION AB In this communication, the numeric results of the heat transfer by natural convection and surface thermal radiation in a tilted 2D open cavity are presented. This study has importance in the thermal design of receivers for solar concentrators. The opposite wall to the aperture in the cavity holds a constant temperature of 500 K, while the temperature of the surrounding fluid interacting with the aperture is 300 K. The other walls are kept insulated. The results in the steady state are obtained for a Rayleigh range from 104 to 107 and for an inclination angles range of the cavity from 0 degrees to 180 degrees. The results show that the Nusselt numbers increase with the Rayleigh number except the convective Nusselt number for 180 degrees, where it stays almost constant. The convective Nusselt number changes substantially with the inclination angle of the cavity, while the radiative Nusselt number is insensitive to the orientation change of the cavity. (c) 2005 Elsevier Ltd. All rights reserved. C1 UNAM, CIE, Morelos 62580, Mexico. Univ Sonora, Dept Ing Quim & Met, Hermosillo, Sonora, Mexico. CENIDET, SNIT, SEP, Cuernavaca, Morelos, Mexico. RP Estrada, CE, UNAM, CIE, AP 24, Morelos 62580, Mexico. EM cestrada@cie.unam.mx CR AKIYAMA M, 1997, NUM HEAT TRANSFER A, V31, P419 ANGIRASA D, 1992, NUMER HEAT TR A-APPL, V22, P223 BALAJI C, 1994, INT J HEAT FLUID FL, V15, P317 CHAKROUN W, 1997, J SOL ENERG-T ASME, V119, P298 CHAN YL, 1985, INT J HEAT MASS TRAN, V28, P603 CHAN YL, 1985, NUMER HEAT TRANSFER, V8, P65 CHAN YL, 1986, J HEAT TRANS-T ASME, V108, P305 DEHGHAN AA, 1996, J HEAT TRANS-T ASME, V118, P56 ELSAYED MM, 1999, J HEAT TRANS-T ASME, V121, P819 GASKELL PH, 1988, INT J NUMER METH ENG, V8, P617 HUMPHREY JAC, 1986, INT J HEAT MASS TRAN, V29, P593 KHANAFER K, 2000, INT J HEAT MASS TRAN, V43, P4087 KHANAFER K, 2002, INT J HEAT MASS TRAN, V45, P2527 LAGE JL, 1992, J HEAT TRANS-T ASME, V114, P479 LEQUERE P, 1981, NUMERICAL HEAT TRANS, V4, P249 MODEST M, 1993, RADIATIVE HEAT TRANS MOHAMAD AA, 1995, NUMER HEAT TR A-APPL, V27, P705 PENOT F, 1982, NUMERICAL HEAT TRANS, V5, P421 POLAT O, 2003, INT J HEAT MASS TRAN, V46, P1563 RAMESH N, 2001, INT J HEAT FLUID FL, V22, P180 SEZAI I, 1998, INT J NUMER METHOD H, V8, P800 SHOWOLE RA, 1993, J HEAT TRANS-T ASME, V115, P592 VAFAI K, 1990, INT J HEAT MASS TRAN, V33, P2311 VANDOORMAAL JP, 1984, NUMER HEAT TRANSFER, V7, P147 VIERENDEELS J, 2003, INT J NUMER METHOD H, V13, P1057 NR 25 TC 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0735-1933 J9 INT COMMUN HEAT MASS TRANS JI Int. Commun. Heat Mass Transf. PD OCT PY 2005 VL 32 IS 9 BP 1184 EP 1192 PG 9 SC Thermodynamics; Mechanics GA 973FO UT ISI:000232508500009 ER PT J AU Bello-Perez, LA De Francisco, A Agama-Acevedo, E Gutierrez-Meraz, F Garcia-Suarez, FJL TI Morphological and molecular studies of banana starch SO FOOD SCIENCE AND TECHNOLOGY INTERNATIONAL LA English DT Article DE banana; starch; X-ray diffraction; microscopy; differential scanning calorimetry ID DIFFERENTIAL SCANNING CALORIMETRY; POTATO STARCH; CHAIN-LENGTH; NATIVE STARCHES; SMALL-INTESTINE; AMYLOPECTIN; CRYSTALLINITY; SPECTROSCOPY; GELATINIZATION; TEMPERATURE AB Molecular and morphological characteristics of banana starch were determined by different spectroscopic techniques. Light and scanning electron microscopy showed the molecular order, shape and size of starch granules. Banana starch granules had a lenticular shape with an average size of 39 mu m. The Xray diffraction study showed starch granules with a pattern of a mixture between the A- and B-type polymorphs, also referred to as C-type. The absorbance ratio (1045/1022 cm(-1)) measured by infrared spectroscopy was 1.12, suggesting that the crystalline component was higher than the amorphous regions. Gelatinisation temperature assessed by differential scanning calorimetry was 77.6 degrees C with a gelatinisation enthalpy of 23.4J/g. These data stated that banana starch had a high crystallinity level, which might be important in several food applications. C1 IPN, Ctr Desarrollo Prod Biot, Yautepec 62731, Morelos, Mexico. Univ Fed Santa Catarina, CERES Cereals Lab, Dept Food Sci & Technol, Florianopolis, SC, Brazil. RP Bello-Perez, LA, IPN, Ctr Desarrollo Prod Biot, POB 24, Yautepec 62731, Morelos, Mexico. EM labellop@ipn.mx CR BELLOPEREZ LA, 1999, J AGR FOOD CHEM, V47, P854 BULEON A, 1982, STARCH-STARKE, V34, P361 BULEON A, 1998, PROPERTIES WATER FOO, P160 CHINACHOTI P, 1986, J FOOD SCI, V51, P997 FAISANT N, 1995, BRIT J NUTR, V73, P111 FAISANT N, 1995, EUR J CLIN NUTR, V49, P98 FLORESGOROZQUIE.E, 2003, THESIS I POLITECNICO FRENCH AD, 1984, STARCH CHEM TECHNOLO, P183 FUJITA S, 1992, STARCH-STARKE, V44, P456 GIDLEY MJ, 1987, CARBOHYD RES, V161, P301 HERMANS PH, 1948, J APPL PHYS, V19, P491 HIZUKURI S, 1983, BIOCHIM BIOPHYS ACTA, V760, P188 HIZUKURI S, 1985, CARBOHYD RES, V141, P295 HOOVER R, 2001, CARBOHYD POLYM, V45, P253 HOOVER R, 2002, FOOD CHEM, V78, P489 JANE J, 1999, CEREAL CHEM, V76, P629 KAUPPINEN JK, 1981, APPL SPECTROSC, V35, P271 KAYISU K, 1981, J FOOD SCI, V46, P1885 LII CY, 1982, J FOOD SCI, V47, P1493 LIU H, 1991, CARBOHYD POLYM, V210, P175 NARA S, 1983, STARCH-STARKE, V35, P407 NYQVIST H, 1983, INT J PHARM TECH PRO, V4, P47 ONG MH, 1994, CARBOHYD RES, V260, P99 RUSSELL PL, 1983, STARCH-STARKE, V35, P382 SEVENOU O, 2002, INT J BIOL MACROMOL, V31, P79 SMITS ALM, 1998, STARCH-STARKE, V50, P478 SPENCE KE, 1999, CARBOHYD POLYM, V40, P261 VANSOEST JJG, 1995, CARBOHYD RES, V279, P201 YOO SH, 2002, CARBOHYD POLYM, V49, P297 YUAN RC, 1993, CEREAL CHEM, V70, P81 NR 30 TC 0 PU SAGE PUBLICATIONS LTD PI LONDON PA 1 OLIVERS YARD, 55 CITY ROAD, LONDON EC1Y 1SP, ENGLAND SN 1082-0132 J9 FOOD SCI TECHNOL INT JI Food Sci. Technol. Int. PD OCT PY 2005 VL 11 IS 5 BP 367 EP 372 PG 6 SC Chemistry, Applied; Food Science & Technology GA 968ZS UT ISI:000232203800006 ER PT J AU Aparicio-Saguilan, A Flores-Huicochea, E Tovar, J Garcia-Suarez, F Gutierrez-Meraz, F Bello-Perez, LA TI Resistant starch-rich powders prepared by autoclaving of native and lintnerized banana starch: Partial characterization SO STARCH-STARKE LA English DT Article DE banana starch; lintnerized starch; resistant starch; thermal analysis ID DIGESTIBILITY; POTATO; GELS AB Powdered preparations enriched in resistant starch (RS) were obtained from native and lintnerized (prolonged acid treatment) banana starches by consecutive autoclaving/cooling treatments. The preparations were tested for indigestible starch content, swelling and solubility properties, thermal analysis and pasting profile. The autoclaved samples had higher RS content than their parental counterparts, but the chemical modification (lintnerization process) allowed development of higher RS proportions (19%, dry matter basis, dmb). The autoclaved samples (RS-enriched products) showed similar swelling values (alpha = 0.05) at the temperatures assessed. These RS-rich products exhibited a lower solubility in water than the corresponding raw materials. The peak temperatures of the thermal transition were 155.5 and 145.8 degrees C for native autoclaved and lintnerized autoclaved starch, respectively. These values indicate that RS products have a marked thermal stability. The pasting behavior of the RS products was less pronounced than that of the raw counterparts. Hence, their potential use as processed food ingredients should not impact final product viscosity. These RS-enriched products appear suitable for the formulation of functional foods. C1 IPN, Ctr Desarrollo Prod Biot, Yautepec 62731, Morelos, Mexico. Cent Univ Venezuela, Fac Ciencias, Inst Expt Biol, Caracas, Venezuela. RP Bello-Perez, LA, IPN, Ctr Desarrollo Prod Biot, Km 8-5 Carr Yautepec Jojutla, Yautepec 62731, Morelos, Mexico. EM labellop@ipn.mx CR *AACC, 2000, APPR METH AACC ASP NG, 1992, TRENDS FOOD SCI TECH, V3, P111 BELLOPEREZ LA, 2000, STARCH-STARKE, V52, P68 BERRY CS, 1986, J CEREAL SCI, V4, P301 BROUNS F, 2002, TRENDS FOOD SCI TECH, V13, P251 ENGLYST HN, 1992, EUR J CLIN NUTR S2, V46, P33 FARHAT IA, 2001, STARCH-STARKE, V53, P431 FREDRIKSSON H, 2000, CARBOHYD POLYM, V43, P81 GONI I, 1996, FOOD CHEM, V56, P445 HERNANDEZLAUZARDO AN, 2004, STARCH-STARKE, V56, P357 HOOVER R, 2001, CARBOHYD POLYM, V45, P253 HOOVER R, 2002, CURRENT PROTOCOLS FO LAURENTIN A, 2003, J AGR FOOD CHEM, V51, P5510 LEHMANN U, 2003, NAHRUNG, V47, P60 MURPHY P, 2000, HDB HYDROCOLLOIDS, P41 NUNEZSANTIAGO MC, 2004, CARBOHYD POLYM, V56, P65 PAREDESLOPEZ L, 1994, FOOD CHEM, V50, P411 SCHOCH TJ, 1964, METHODS CARBOHYDRATE, V4, P106 SHAMAI K, 2003, CARBOHYD POLYM, V54, P363 SHIN M, 2003, CEREAL CHEM, V80, P564 SIEVERT D, 1989, CEREAL CHEM, V66, P342 SKRABANJA V, 1999, J AGR FOOD CHEM, V47, P2033 TOVAR J, 1999, RRD AGR FOOD CHEM 1, V3, P1 TOVAR J, 2002, FOOD CHEM, V76, P455 NR 24 TC 4 PU WILEY-V C H VERLAG GMBH PI WEINHEIM PA PO BOX 10 11 61, D-69451 WEINHEIM, GERMANY SN 0038-9056 J9 STARCH JI Starch-Starke PD SEP PY 2005 VL 57 IS 9 BP 405 EP 412 PG 8 SC Food Science & Technology GA 967AX UT ISI:000232065000002 ER PT J AU Patino-Vera, M Jimenez, B Balderas, K Ortiz, M Allende, R Carrillo, A Galindo, E TI Pilot-scale production and liquid formulation of Rhodotorula minuta, a potential biocontrol agent of mango anthracnose SO JOURNAL OF APPLIED MICROBIOLOGY LA English DT Article DE anthracnose; fermentation; formulation; mango; Rhodotorula; scale-up ID BIOLOGICAL-CONTROL; CANDIDA-SAKE; CAROTENOID PRODUCTION; POSTHARVEST DISEASES; GLUTINIS MUTANT-32; WATER ACTIVITY; GRACILIS; CULTURES; STRAINS; FRUITS AB Aims: To develop a pilot-plant fermentation process for the production of the yeast Rhodotorula minuta, to be used as a blocontrol agent of mango anthracnose, using a low-cost culture medium. To develop a stable liquid formulation that preserve high viability of the yeast stored at 4 degrees C. Methods and Results: Keeping constant the volumetric power input, a fermentation process was scaled-up from shake flasks to a 100 1 bioreactor. Preharvest applications of the yeast resulted in postharvest anthracnose severity equal or lower than that observed with a chemical fungicide. Glycerol was added to the formulation as water activity reducer and xanthan gum as a viscosity-enhancing agent. Yeast initial concentration of 10(10) CFU ml(-1) resulted in 4-5 orders of magnitude decrease after 1 month of storage at VC, whereas when it was formulated at 109 CFU ml(-1), the decrease was of two orders of magnitude in. 6 months. Conclusions: The fermentation process was successfully scaled-up using a low-cost culture medium. Postharvest anthracnose severity could be considerably reduced using this yeast. Formulating the yeast at 109 CFU ml(-1) and adding glycerol (20%) and xanthan (5 g l(-1)) avoided both contamination and yeast sedimentation and it was able to preserve up to 10(7) CFU ml(-1) after 6 months at VC. Significance and Impact of the Study: The yeast R. minuta is reported as a novel antagonistic micro-organism against the pathogen Colletotrichum gloeosportoides. Pilot plant production of this yeast allowed us to conduct field tests in commercial orchards during three harvest seasons. Yeast suspensions applied to mango trees reduced the fruit anthracnose severity in levels similar or better than chemical fungicides. C1 Natl Autonomous Univ Mexico, Inst Biotechnol, Dept Cellular Engn & Biocatalysis, Scaling Up & Pilot Plant Unit, Cuernavaca 62250, Morelos, Mexico. Culiacan Unit, Res Ctr Food & Dev, Sinaloa, Mexico. RP Galindo, E, Natl Autonomous Univ Mexico, Inst Biotechnol, Dept Cellular Engn & Biocatalysis, Scaling Up & Pilot Plant Unit, Apdo Postal 510-3, Cuernavaca 62250, Morelos, Mexico. EM galindo@ibt.unam.mx CR *FAO, 2002, STAT 1990 2002 MANG ABADIAS M, 2003, PHYTOPATHOLOGY, V93, P436 ABD EHM, 2000, ANN AGR SCI A SHAMS, V45, P633 ALLENDE R, 2001, BRAZ PHYTOPATHOL S, V26, P461 ARAUZ LF, 2000, PLANT DIS, V84, P600 BENBOW JM, 1999, PLANT DIS, V83, P839 BHOSALE P, 2001, LETT APPL MICROBIOL, V33, P12 BHOSALE P, 2003, J APPL MICROBIOL, V95, P584 BUCHS J, 2000, BIOTECHNOL BIOENG, V68, P589 BURGES HD, 1998, FORMULATION MICROBIA, P165 BUZZINI P, 2001, J APPL MICROBIOL, V90, P843 CALVENTE V, 2001, J IND MICROBIOL BIOT, V26, P226 DEJAGER ES, 2001, MICROBIAL ECOL, V42, P201 FREEMAN S, 1998, PLANT DIS, V82, P596 GALAN SV, 1999, CULTIVO MANGO, P291 GOVINDASWAMY V, 2001, EUR FOOD RES TECHNOL, V213, P234 HELBIG J, 2001, J PL DIS PROT, V108, P356 HENZLER HJ, 1991, BIOPROCESS ENG, V7, P123 HOFSTEIN R, 1994, BIOL CONTROL POSTHAR, P89 JAKUBOWSKI W, 2000, FREE RADICAL BIO MED, V28, P659 JANISIEWICZ WJ, 2002, ANNU REV PHYTOPATHOL, V40, P411 KOOMEN I, 1993, PLANT PATHOL, V42, P230 MARTINEZ A, 1989, J FERMENT BIOENG, V68, P71 MORA AJ, 1998, MANGO MANEJO INTEGRA, P1 MUGNIER J, 1985, APPL ENVIRON MICROB, V50, P108 NAIDU HA, 1999, Z LEBENSM UNTERS F A, V208, P444 ONISHI N, 1996, J FERMENT BIOENG, V82, P124 PERRIER V, 1995, ARCH MICROBIOL, V164, P173 PIANO S, 1998, ATTI GIORNATE FITOPA, P495 PLOETZ RC, 1994, COMPENDIUM TROPICAL, P35 PLOETZ RC, 1997, MANGO BOT PRODUCTION, P281 PRENEY L, 2003, MYCOSES, V46, P492 RESENDIZ R, 1991, CHEM ENG TECHNOL, V14, P105 RODHAM DK, 1999, PESTIC SCI, V55, P340 SMOOT JJ, 1963, PLANT DIS REP, V47, P739 SOMASHEKAR D, 2000, WORLD J MICROB BIOT, V16, P491 SPADARO D, 2004, INT J FOOD MICROBIOL, V91, P185 TORRES R, 2003, J APPL MICROBIOL, V94, P330 VEGA PA, 2001, ENFERMEDADES NORMATI, P49 VINAS I, 1998, INT J FOOD MICROBIOL, V40, P9 WANG DN, 2002, MOL BIOTECHNOL, V21, P1 NR 41 TC 0 PU BLACKWELL PUBLISHING PI OXFORD PA 9600 GARSINGTON RD, OXFORD OX4 2DQ, OXON, ENGLAND SN 1364-5072 J9 J APPL MICROBIOL JI J. Appl. Microbiol. PY 2005 VL 99 IS 3 BP 540 EP 550 PG 11 SC Biotechnology & Applied Microbiology; Microbiology GA 961ZO UT ISI:000231701000012 ER PT J AU Agustiniano-Osornio, JC Gonzalez-Soto, RA Flores-Huicochea, E Manrique-Quevedo, N Sanchez-Hernandez, L Bello-Perez, LA TI Resistant starch production from mango starch using a single-screw extruder SO JOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE LA English DT Article DE extrusion; mango; starch; physicochemical properties ID DIFFERENTIAL SCANNING CALORIMETRY; SMALL-INTESTINE; DIGESTION; L.; HYDROLYSIS; COOKING; POTATO; TIME; PEA AB Resistant starches were prepared from mango starch by extrusion. An experimental design with independent variables temperature, screw speed and moisture content produced 20 samples that were studied to determine the effect of these variables on resistant starch (RS) content, water absorption index (WAI) and water solubility index (WSI). RS content was affected by moisture content and temperature. Screw speed and temperature also influenced RS content, the highest level (97 g kg(-1)) being obtained at low screw speed and high temperature, this pattern can be associated with a longer residence time, which gives rise to more opportunity for amylose chain association. The regression model fitted to the RS experimental results showed a good correlation coefficient (0.80). When moisture content and temperature decreased, WAI increased (105-142 g kg(-1)), but low WAI values (70-77 g kg(-1)) were obtained at moisture contents between 200 and 300 g kg(-1) and high temperatures (140-150 degrees C). When moisture content and temperature increased, WSI increased (222-332 g kg(-1)), but at high temperature value (120 degrees C) assayed and the lowest moisture content (150 g kg(-1)), WSI also increased. In the range of moisture contents tested and at low temperatures, only partial gelatinisation occurred and low solubility was obtained. (c) 2005 Society of Chemical Industry. C1 Ctr Desarrollo Prod Biot IPN, Morelos 62731, Mexico. Inst Tecnol Acapulco, Acapulco, Guerrero, Mexico. RP Bello-Perez, LA, Ctr Desarrollo Prod Biot IPN, Km 8-5 Carr Yautepec Jojutla,Apartado Postal 24, Morelos 62731, Mexico. EM labellop@ipn.mx CR *AACC, 2000, APPR METH AN ALTOMARE RE, 1986, BIOTECHNOL PROGR, V2, P157 ALVES RML, 1999, FOOD CHEM, V67, P123 ANDERSON RA, 1969, CEREAL SCI TODAY, V14, P4 ASP NG, 1992, EUR J CLIN NUTR S2, V46, S1 ASP NG, 1996, NUTR RES REV, V9, P1 ASP NG, 1998, EXTRUSION COOKING, P339 BELLOPEREZ LA, 1999, J AGR FOOD CHEM, V47, P854 BERRY CS, 1988, J CEREAL SCI, V8, P203 CHIU CW, 1994, 5281276, US COLONNA P, 1994, EXTRUSION COOKING, P18 DELLAVALLE G, 1989, LEBENSM WISS TECHNOL, V22, P279 DONOVAN JW, 1979, BIOPOLYMERS, V18, P263 EERLINGEN RC, 1993, CEREAL CHEM, V70, P339 EERLINGEN RC, 1993, CEREAL CHEM, V70, P345 EERLINGEN RC, 1994, CEREAL CHEM, V71, P472 ENGLYST HN, 1987, AM J CLIN NUTR, V45, P423 ENGLYST HN, 1992, EUR J CLIN NUTR S2, V46, P33 ESCARPA A, 1996, J AGR FOOD CHEM, V44, P924 FAISANT N, 1995, EUR J CLIN NUTR, V49, P98 GARCIAALONSO A, 1998, CEREAL CHEM, V75, P802 GONI I, 1996, FOOD CHEM, V56, P445 GONI I, 1997, NUTR RES, V17, P427 GONZALEZREYES E, 2003, CARBOHYD POLYM, V52, P297 HOOVER R, 2001, CARBOHYD POLYM, V45, P253 HOOVER R, 2002, FOOD CHEM, V78, P489 IYENGAR R, 1991, 5051271, US KAUR M, 2004, FOOD CHEM, V85, P131 KIM YS, 1995, J FOOD SCI, V60, P1060 LAURENTIN A, 2003, J AGR FOOD CHEM, V51, P5510 LEHMANN U, 2002, J AGR FOOD CHEM, V50, P5236 LEHMANN U, 2003, NAHRUNG, V47, P60 LEONEL M, 2003, CARBOHYD POLYM, V54, P385 LINTAS C, 1992, EUR J CLIN NUTR S2, V46, S103 NOAH L, 1998, J NUTR, V128, P977 SHIN M, 2003, CEREAL CHEM, V80, P564 SIEVERT D, 1989, CEREAL CHEM, V66, P342 SIEVERT D, 1990, CEREAL CHEM, V67, P217 SKRABANJA V, 1999, J AGR FOOD CHEM, V47, P2033 SZCZODRAK J, 1992, CEREAL CHEM, V69, P626 TOVAR J, 1992, J NUTR, V122, P1500 UNLU E, 1998, CEREAL CHEM, V75, P346 VERGNES B, 1987, J CEREAL SCI, V5, P189 NR 43 TC 3 PU JOHN WILEY & SONS LTD PI CHICHESTER PA THE ATRIUM, SOUTHERN GATE, CHICHESTER PO19 8SQ, W SUSSEX, ENGLAND SN 0022-5142 J9 J SCI FOOD AGR JI J. Sci. Food Agric. PD SEP PY 2005 VL 85 IS 12 BP 2105 EP 2110 PG 6 SC Agriculture, Multidisciplinary; Chemistry, Applied; Food Science & Technology GA 961AH UT ISI:000231633800021 ER PT J AU Munoz-Rojas, J Fuentes-Ramirez, LE Caballero-Mellado, J TI Antagonism among Gluconacetobacter diazotrophicus strains in culture media and in endophytic association SO FEMS MICROBIOLOGY ECOLOGY LA English DT Article DE antagonism; bacteriocins; endophytic bacteria; sugarcane ID GRAM-POSITIVE BACTERIA; LACTIC-ACID BACTERIA; ACETOBACTER-DIAZOTROPHICUS; AZOSPIRILLUM-BRASILENSE; SUGARCANE CULTIVARS; HOST-PLANT; ELECTROPHORESIS; IDENTIFICATION; PERSPECTIVES; DIVERSITY AB In this study the antagonistic activity among 55 Gluconacetobacter diazotrophicus strains, belonging to 13 electrophoretic types (ETs), in culture media was analyzed. Antagonistic effects were seen only in strains belonging to two ETs named ET-1 and ET-3. Two out of 29 ET-1 strains, and 3 out of 7 ET-3 strains of G. diazotrophicus showed antagonistic effects against many other strains belonging to all the ETs of this species analyzed, and against closely related strains of Gluconacetobacter species, including Gluconacetobacter johannae, Gluconacetobacter azotocaptans and Gluconacetobacter liquefaciens but not against other phylogenetically distant bacterial species. Results showed that the substance responsible of such antagonistic activity is a low molecular mass molecule (approximately 3400 Da), stable from pH 3.5 to 8.5, and very stable at 4 degrees C for 10 months. This substance was sensitive to proteases, and the antagonistic activity was lost after 2 h at 95 degrees C. All of these features show that the substance is related to bacterlocin-like molecules. The antagonistic substance should be chromosomally encoded because ET-3 strains of G. diazotrophicus do not harbor any plasmids. The antagonistic ability of ET-3 strains of G. diazotrophicus could be an advantage for the natural colonization of the sugarcane environment, as was observed in experiments with micropropagated sterile sugarcane plantlets co-inoculated with a bacteriocin-producer strain and a bacteriocin-sensitive strain of G. diazotrophicus. In these experiments, both in the rhizosphere as well as inside the roots, the bacteriocin-sensitive population decreased drastically. In addition, this study shows that inside the plants there may exist antagonistic interactions among endophytic bacteria like to those described among the rhizospheric community. (c) 2005 Federation of European Microbiological Societies. Published by Elsevier B.V. All rights reserved. C1 Univ Nacl Autonoma Mexico, Ctr Invest Fijac Nitrogeno, Programa Ecol Mol & Microbiana, Cuernavaca, Morelos, Mexico. Univ Autonoma Puebla, Ctr Invest Microbiol, Lab Microbiol Suelos, Puebla, Mexico. RP Caballero-Mellado, J, Univ Nacl Autonoma Mexico, Ctr Invest Fijac Nitrogeno, Programa Ecol Mol & Microbiana, Ap Postal No 565-A, Cuernavaca, Morelos, Mexico. EM jesuscab@cifn.unam.mx CR ASHBOLT NJ, 1990, APPL ENVIRON MICROB, V56, P707 ASSMUS B, 1995, APPL ENVIRON MICROB, V61, P1013 BRUNO MEC, 1993, APPL ENVIRON MICROB, V59, P3003 CABALLEROMELLADO J, 1994, APPL ENVIRON MICROB, V60, P1532 CABALLEROMELLADO J, 1995, APPL ENVIRON MICROB, V61, P3008 CABALLEROMELLADO J, 1999, FEMS MICROBIOL LETT, V178, P283 CAVALCANTE VA, 1988, PLANT SOIL, V108, P23 CURI EA, 1986, RHIZOSPHERE DEVUYST L, 1995, J APPL BACTERIOL, V78, P28 DOBEREINER J, 1992, SYMBIOSIS, V13, P1 FUENTESRAMIREZ LE, 1993, PLANT SOIL, V154, P145 FUENTESRAMIREZ LE, 1999, FEMS MICROBIOL ECOL, V29, P117 GOEL AK, 2001, INDIAN J EXP BIOL, V39, P821 GONZALEZPASTOR JE, 1995, J BACTERIOL, V177, P7131 HANCOCK REW, 1999, ANTIMICROB AGENTS CH, V43, P1317 HIRSCH PR, 1979, J GEN MICROBIOL, V113, P219 HODGSON ALM, 1985, SOIL BIOL BIOCHEM, V17, P475 JACK RW, 1995, MICROBIOL REV, V59, P171 JIMENEZSALGADO T, 1997, APPL ENVIRON MICROB, V63, P3676 LI RP, 1992, SOIL BIOL BIOCHEM, V24, P413 LOGANATHAN P, 1999, J APPL MICROBIOL, V87, P167 LOPER JE, 1991, MOL PLANT MICROBE IN, V4, P5 MADHAIYAN M, 2004, MICROBIOL RES, V159, P233 MUNOZROJAS J, 2003, MICROBIAL ECOL, V46, P454 MURASHIGE T, 1962, PHYSIOL PLANTARUM, V15, P473 PARENTE E, 1999, APPL MICROBIOL BIOT, V52, P628 PINON D, 2002, RES MICROBIOL, V153, P345 RILEY MA, 2002, BIOCHIMIE, V84, P357 RODRIGUEZCACERE.EA, 1982, APPL ENVIRON MICROB, V44, P990 SCHAGGER H, 1987, ANAL BIOCHEM, V166, P368 SELANDER RK, 1985, J BACTERIOL, V163 SELANDER RK, 1986, APPL ENVIRON MICROB, V51, P873 SMAJS D, 1997, J BACTERIOL, V179, P4919 SMIDT ML, 1982, CAN J MICROBIOL, V28, P600 SMITH DR, 1994, J BACTERIOL, V1761, P201 SOLBIATI JO, 1996, J BACTERIOL, V178, P3661 TAGG JR, 1976, BACTERIOL REV, V40, P722 TAPIAHERNANDEZ A, 2000, MICROBIAL ECOL, V39, P49 TEXEIRA KRS, 1994, NITROGEN FIXATION NO, P273 VANZYL FGH, 1986, APPL ENVIRON MICROB, V52, P234 NR 40 TC 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-6496 J9 FEMS MICROBIOL ECOL JI FEMS Microbiol. Ecol. PD SEP 1 PY 2005 VL 54 IS 1 BP 57 EP 66 PG 10 SC Microbiology GA 959VV UT ISI:000231548300006 ER PT J AU Agama-Acevedo, E Rendon-Villalobos, R Tovar, J Trejo-Estrada, SR Bello-Perez, LA TI Effect of storage time on in vitro digestion rate and resistant starch content of tortillas elaborated from commercial corn masas SO ARCHIVOS LATINOAMERICANOS DE NUTRICION LA English DT Article DE corn; texture; tortillas; resistant starch; starch digestibility ID PHASEOLUS-VULGARIS L.; SMALL-INTESTINE; GLYCEMIC-INDEX; FOOD; MAIZE; HYDROLYSIS; FLOURS; DIGESTIBILITY; FRACTIONS; POTATO AB Tortilla samples were elaborated by four small commercial factories in Mexico, employing masas prepared with the traditional nixtamalization process. Samples were stored at 4 degrees C for up to 72 hours and their chemical composition and in vitro starch digestibility features were evaluated. Chemical composition did not change with the storage time, but soluble carbohydrates decreased slightly during storage. A significant decrease in available starch content upon storage was observed, concomitant with increased resistant starch (RS) levels. These changes are possibly due to retrogradation. Retrograded resistant starch (RRS) values increased with storage time; in some samples, RRS represented more than 75% of total RS whereas in others it only accounted for 25%. The digestion rate (DR) in the freshly prepared tortillas was similar for the various samples, but after 72 h storage some differences among tortillas were found. Also, when a single tortilla sample was compared throughout the different storage times, lower DRs were determined in samples subjected to prolonged storage, which is related to the concomitant increase in RRS. The differences found among the various tortilla samples may be due to minor variations in the commercial processing conditions and to the use of different corn varieties. C1 IPN, Ctr Desarrollo Prod Biot, Yautepec, Morelos, Mexico. Cent Univ Venezuela, Fac Ciencias, Inst Expt Biol, Caracas, Venezuela. IPN, Ctr Invest Ciencia Aplicada & Tecnol Avanzada, Puebla, Mexico. RP Agama-Acevedo, E, IPN, Ctr Desarrollo Prod Biot, Yautepec, Morelos, Mexico. CR *AACC, 2000, APPR METH AACC STPAU *SPSS, 1996, PROGR AN EST MEX MCG ASP NG, 1992, EUR J CLIN NUTR S2, V46, S1 ASP NG, 1996, NUTR RES REV, V9, P1 BILIADERIS CG, 1991, CAN J PHYSIOL PHARM, V69, P60 BJORCK I, 1994, AM J CLIN NUTR, V59, S699 BRAVO L, 1998, J AGR FOOD CHEM, V46, P4667 CAMPASBAYPOLI ON, 2002, STARCH-STARKE, V54, P358 CAMPUSBAYPOLI ON, 1999, STARCH-STARKE, V51, P173 CASSIDY A, 1994, BRIT J CANCER, V69, P937 DEDECKERE EAM, 1995, BRIT J NUTR, V73, P287 DUBOIS M, 1956, ANAL CHEM, V28, P350 ENGLYST HN, 1987, AM J CLIN NUTR, V45, P423 ENGLYST HN, 1992, EUR J CLIN NUTR S2, V46, P33 FAISANT N, 1995, EUR J CLIN NUTR, V49, P98 FLORESFARIAS R, 2002, AGROCIENCIA, V36, P557 FREDRIKSSON H, 2000, CARBOHYD POLYM, V43, P81 GARCIAALONSO A, 1999, FOOD CHEM, V66, P181 GOMEZ MH, 1987, CEREAL FOOD WORLD, V32, P372 GONI I, 1996, FOOD CHEM, V56, P445 GONI I, 1997, NUTR RES, V3, P423 HOLM J, 1985, J CEREAL SCI, V3, P193 HOLM J, 1986, STARCH-STARKE, V38, P224 JENKINS DJA, 1987, AM J CLIN NUTR, V46, P968 NOAH L, 1998, J NUTR, V128, P977 RENDONVILLALOBOS R, 2002, CEREAL CHEM, V79, P340 SALDANA G, 1984, J FOOD SCI, V49, P1202 SANMARTINMARTINEZ E, 2003, CEREAL CHEM, V80, P13 SAURACALIXTO F, 1993, J FOOD SCI, V58, P642 SKRABANJA V, 1999, J AGR FOOD CHEM, V47, P2033 SNOW P, 1981, AM J CLIN NUTR, V34, P2721 TOVAR J, 1992, J NUTR, V122, P1500 TOVAR J, 2001, FIBRA DIETETICA IBER, P143 TOVAR J, 2002, FOOD CHEM, V76, P455 TOVAR J, 2003, CEREAL CHEM, V80, P533 YAU JC, 1994, CEREAL FOOD WORLD, V39, P396 NR 36 TC 2 PU ARCHIVOS LATINOAMERICANOS NUTRICION PI CARACAS PA APARTADO 62778 CHACAO, AVENIDA FRANCISCO MIRANDA, CARACAS 1060, VENEZUELA SN 0004-0622 J9 ARCH LATINOAMER NUTR JI Arch. Latinoam. Nutr. PD MAR PY 2005 VL 55 IS 1 BP 86 EP 92 PG 7 SC Nutrition & Dietetics GA 958VW UT ISI:000231477300012 ER PT J AU Fragiel, B Serna, S Perez, R TI Electrochemical study of two microalloyed pipeline steels in H2S environments SO INTERNATIONAL JOURNAL OF HYDROGEN ENERGY LA English DT Article DE H2S environment; microalloyed steel; localized corrosion; diffusion control ID CORROSION AB The electrochemical behavior of microalloyed steel under H2S environment at room temperature and at 55 degrees C suggests that the superficial degradation in this steel is due to the combination of several mechanisms in which uniform corrosion plays a less relevant role, while localized corrosion and diffusion control (where diffusion of species such as H2S, HS- is possible) are key mechanisms for the corrosion process of this steel. It also was found that the limiting current (it) increases proportionally with increase in temperature, leaving clear evidence for the existence of diffusion control. The estimation of corrosion rates by means of the Rp technique, taking into account the diffusion control shows that, at room temperature, steel 2 presents the lowest corrosion rate with respect to steel 1. This behavior is reversed at 55 degrees C, steel 2 being more susceptible to corrosion. (c) 2005 International Association for Hydrogen Energy. Published by Elsevier Ltd. All rights reserved. C1 Inst Mexicano Petr, Mexico City 07730, DF, Mexico. UNAM, Ctr Ciencias Mat Condensada, Ensenada, Baja California, Mexico. UNAM, Fac Quim, Mexico City, DF, Mexico. UAEM, Ctr Invest Ingn & Ciencias Aplicadas, Cuernavaca 62251, Morelos, Mexico. RP Perez, R, Inst Mexicano Petr, Eje Cent 152,Col Sn Bartolo Atepehuacan, Mexico City 07730, DF, Mexico. EM rcamposp@imp.mx CR 1980, ASM COMM CARB ALL ST, V3, P3 ANDERKO A, 1999, CORROSION P ARIETA FG, 1993, MINERALS METALS MAT, P101 EDEN DA, 1998, CORROSION P GERUS BRD, 1981, H2S CORROSION OIL GA, P888 JUN HJ, 2003, SCRIPTA MATER, V49, P1081 MA HY, 2000, CORROS SCI, V42, P1669 MANSFELD F, 1999, CORROSION, V55, P915 SRINIVASAN S, 1999, CORROSION P VELOZ MA, 2002, ELECTROCHIM ACTA, V48, P135 NR 10 TC 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0360-3199 J9 INT J HYDROGEN ENERG JI Int. J. Hydrog. Energy PD SEP PY 2005 VL 30 IS 12 BP 1303 EP 1309 PG 7 SC Chemistry, Physical; Energy & Fuels; Environmental Sciences; Physics, Atomic, Molecular & Chemical GA 954MH UT ISI:000231158700003 ER PT J AU Torres-Islas, A Salinas-Bravo, VM Albarran, JL Gonzalez-Rodriguez, JG TI Effect of hydrogen on the mechanical properties of X-70 pipeline steel in diluted NaHCO3 solutions at different heat treatments SO INTERNATIONAL JOURNAL OF HYDROGEN ENERGY LA English DT Article DE pipeline X-70 steel; diluted bicarbonate solutions; stress corrosion cracking ID STRESS-CORROSION CRACKING; NEAR-NEUTRAL-PH; BICARBONATE SOLUTION; CARBONATE SOLUTIONS; FERRITIC STEELS; X-80 AB Studies were carried out on the effect of hydrogen on the mechanical properties of X-70 pipeline steel at different heat treatment conditions. Heat treatments were carried out as-received, under water-quenched, water-quenched and tempered and water-sprayed conditions. The solutions used consisted of 0.1, 0.05, 0.01 and 0.005 M sodium bicarbonate (NaHCO3) for the slow strain rate testing (SSRT) technique and hydrogen permeation measurements at 50 degrees C. Hydrogen permeation increased with solution concentration and was maximum for the quenched steel. Pre-charging of specimens with hydrogen did not have any effect on the mechanical properties of the as-received or water-sprayed steel but it did in the quenched and the quenched+tempered steels. In all the heat treatments, the mechanical properties of the steel were seriously affected only in 0.005 M NaHCO3, the steel in the quenched condition being the most susceptible. The cracking mechanism is dominated by anodic dissolution, film rupture of the steel in the as-received and water-sprayed conditions. But it was dominated by hydrogen embrittlement for the quenched and the quenched+tempered steels. (c) 2005 International Association for Hydrogen Energy. Published by Elsevier Ltd. All rights reserved. C1 UAEM, CIICAp, Cuernavaca 62210, Morelos, Mexico. UNAM, Fac Quim, Circuito Univ, Mexico City, DF, Mexico. IIE Sistemas Combust, Temixco, Morelos, Mexico. RP Gonzalez-Rodriguez, JG, UAEM, CIICAp, Av Univ 1001,Col Chamilpa, Cuernavaca 62210, Morelos, Mexico. EM ggonzalez@uaem.mx CR BEAVERS JA, 1996, INT PIP C, V1, P565 DELANTY B, 1985, OIL GAS J, V20, P139 DEVANATHAN MAV, 1962, P ROY SOC LOND A MAT, V270, P90 GU B, 1999, CORROSION, V55, P312 JUSTICE RH, 1988, P NG 19 EPRG 7 BIENN LOPEZ HF, 1996, METALL MATER TRANS A, V27, P3601 LOPEZ HF, 1999, METALL MATER TRANS A, V30, P2419 MAO X, 1994, CORROSION, V50, P651 MIGHT J, 1996, CORROSION, V52, P428 PARKINS RN, 1974, 5 S PIP LIN RES PARKINS RN, 1994, CORROSION, V50, P394 PARKINS RN, 1996, CORROSION, V52, P363 PARKINS RN, 2003, CORROSION, V59, P258 PILKEY AK, 1995, CORROSION, V51, P91 SUTCLIFFE JM, 1972, CORROSION, V28, P313 SZLARSKASMIALOW.Z, 1994, CORROSION, V50, P334 ZHANG XY, 1999, CORROSION, V55, P297 NR 17 TC 2 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0360-3199 J9 INT J HYDROGEN ENERG JI Int. J. Hydrog. Energy PD SEP PY 2005 VL 30 IS 12 BP 1317 EP 1322 PG 6 SC Chemistry, Physical; Energy & Fuels; Environmental Sciences; Physics, Atomic, Molecular & Chemical GA 954MH UT ISI:000231158700005 ER PT J AU Serna, S Martinez, H Lopez, SY Gonzalez-Rodriguez, JG Albarran, JL TI Electrochemical technique applied to evaluate the hydrogen permeability in microalloyed steels SO INTERNATIONAL JOURNAL OF HYDROGEN ENERGY LA English DT Article DE electrochemical technique; hydrogen diffusion; irreversible-reversible traps; microalloyed steels; working temperature ID STRESS-CORROSION CRACKING; ENVIRONMENTS AB A potentiostatic electrochemical technique was used in order to assess the hydrogen permeation performance in relation to the microstructural characteristics of two microalloyed steels with similar strength produced by different manufacturing processes, taking into account the fact that one of the steels is considered to be in the developmental stage (steel 13). The tests were carried out at steels' rest potentials in an aqueous sour environment at 25 and 50 degrees C. The results indicate that steel B is better than steel A at 25 degrees C to resist any embrittlement effect related to hydrogen. This behavior could be explained in terms of reversible and irreversible sites for hydrogen trapping. At 50 degrees C, both steels have a dramatically better hydrogen permeability performance. Moreover, hydrogen diffusion activation energies, effective diffusive coefficients and sub-surface hydrogen concentration values are in accordance with the observed behavior of the steels. (c) 2005 Published by Elsevier Ltd on behalf of the International Association for Hydrogen Energy. C1 UAEM, Ctr Invest Ingn & Ciencias Aplicadas, Cuernavaca 82210, Morelos, Mexico. UNAN, Ctr Ciencias Fis, Cuernavaca 62251, Morelos, Mexico. UNAM, Fac Quim, Mexico City, DF, Mexico. RP Serna, S, UAEM, Ctr Invest Ingn & Ciencias Aplicadas, Av Univ 1001, Cuernavaca 82210, Morelos, Mexico. EM aserna@uaem.mx CR BARTERI M, 1987, CORROS SCI, V27, P1239 CHARLEUX M, 2001, METALL MATER TRANS A, V32, P1635 CRAIG B, 1990, P C HYDR EFF MAT BEH, P955 CRAIG BD, 1982, METALL T A, V13, P1099 DEVANATHAN MAV, 1962, P ROY SOC LOND A MAT, V270, P90 DURAIRAJAN A, 2000, CORROSION, V56, P284 HILL RT, 1985, P INT C HSLA STEELS, P753 HUDGINS CM, 1981, H2S CORROSION OIL GA, P90 LE TT, 1994, P 2 CAN JAP S MOD ST, P29 MERRICK RD, 1988, MP, V27, P30 OHRING M, 1995, ENG MAT SCI, P266 RICHERT JP, 1988, MP, V27, P9 TESSEDER RS, 1981, H2S CORROSION OIL GA, P147 TOMITA Y, 1994, J MATER SCI, V29, P2873 TURNBULL A, 1992, METALL TRANS A, V23, P3231 TURNBULL A, 1994, P HYDROGEN TRANSPORT, P1219 VANGELDER K, 1987, CORROS SCI, V27, P1271 YANG SW, 2000, P 4 INT C HSLA STEEL, P227 NR 18 TC 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0360-3199 J9 INT J HYDROGEN ENERG JI Int. J. Hydrog. Energy PD SEP PY 2005 VL 30 IS 12 BP 1333 EP 1338 PG 6 SC Chemistry, Physical; Energy & Fuels; Environmental Sciences; Physics, Atomic, Molecular & Chemical GA 954MH UT ISI:000231158700007 ER PT J AU Salinas-Bravo, VM Porcayo-Calderon, J Romero-Castanon, T Dominguez-Patino, G Gonzalez-Rodriguez, JG TI Corrosion behavior of Fe-Si metallic coatings added with NiCrAlY in an environment of fuel oil ashes at 700 degrees C SO MATERIALS AND CORROSION-WERKSTOFFE UND KORROSION LA English DT Article AB Electrochemical potentiodynamic polarization curves and immersion tests for 300 h at 700 degrees C in a furnace have been used to evaluate the corrosion resistance of Fe-Si metallic coatings added with up to 50 wt.% of NiCrAIY. The corrosive environment was fuel oil ashes from a steam generator. The composition of fuel oil ashes includes high content of vanadium, sodium and sulfur. The results obtained show that only the addition of 20 wt.% NiCrAIY to the Fe-Si coating improves its corrosion resistance. The behavior of all tested coatings is explained by the results obtained from the analysis of every coating using electron microscopy and energy dispersive X-ray analysis. C1 UAEM, Ctr Invest Ingn & Ciencias Aplicadas, Cuernavaca, Morelos, Mexico. Inst Invest Elect, Temixco, Morelos, Mexico. RP Gonzalez-Rodriguez, JG, UAEM, Ctr Invest Ingn & Ciencias Aplicadas, Av Univ 1001,CP 62210, Cuernavaca, Morelos, Mexico. EM ggonzalez@uaem.nix CR CALDERON JP, 1995, MAT PERFORMANCE, V34 CALDERON JP, 1997, THESIS U NACL AUTONO CUTLER AJB, 1978, CEGB RES OCT, P13 DOOLEY RB, 1996, 105261 EPRI TR GRUNLING HW, 1982, THIN SOLID FILMS, V95, P3 MCDOWELL DW, 1960, 60WA20 ASME PAUL LD, 1990, 267 NACE INT QUADAKKERS WJ, 1994, MATER SCI TECH SER, V10, P126 WARNES BM, 2002, OXID MET, V58, P587 WHITTINGHAM G, 1961, OIL FIRED BOILERS WILSON JR, 1976, 12 NACE INT WOLF I, 1988, OXID MET, V29, P289 NR 12 TC 0 PU WILEY-V C H VERLAG GMBH PI WEINHEIM PA PO BOX 10 11 61, D-69451 WEINHEIM, GERMANY SN 0947-5117 J9 MATER CORROS JI Mater. Corros. PD JUL PY 2005 VL 56 IS 7 BP 481 EP 484 PG 4 SC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering GA 949DG UT ISI:000230764500005 ER PT J AU Martinez, H Rosales, I TI Pulsed plasma nitrided Nb alloyed Mo3Si intermetallic alloy SO SURFACE ENGINEERING LA English DT Article DE intermetallic; molybdenum silicides; hardness; nitrided treatment; pulsed plasma nitrided; alloys; surface modifications; mechanical properties; diffusion; X-ray diffraction; optical emission spectroscopy; SEM; nitricled specimens; thermochernical treatment; energy dispersive spectroscopy ID MECHANICAL-PROPERTIES; OXIDATION BEHAVIOR AB Pulsed nitrided plasma of Mo3Si intermetallic alloys with different Nb concentrations were treated in a nitrided atmosphere of 50%H-2-50%N-2 at pressure 533 Pa and temperature 950 degrees C for 8 h. The pulsed nitrided plasma was studied by optical emission spectroscopy (OES). Strong intensities of N-2, N-2(+) and NH excited states were observed in the OES in the negative glow of H-2-N-2 pulsed plasma. Several alloys with different additions of Nb solid solution were treated. Nitrided specimens were analsed by SEM and X-ray diffraction;, microhardness measurements were also evaluated. After the nitrided treatment, the alloy with more than 10 at.-%Nb increased its surface hardness by 16.6%, presumably by the formation of NbN. C1 UNAM, Ctr Ciencias Fis, Cuernavaca 62210, Morelos, Mexico. Ctr Invest Ingn & Ciencias Aplicadas, Cuernavaca 62210, Morelos, Mexico. RP Martinez, H, UNAM, Ctr Ciencias Fis, Apdo Postal 48-3, Cuernavaca 62210, Morelos, Mexico. EM hm@fis.unam.mx CR AKINC M, 1999, MAT SCI ENG A-STRUCT, V261, P15 CRANDALL DH, 1974, PHYS REV A, V9, P2545 GEYANG L, 2002, J VAC SCI TECHNOL A, V20, P674 MELETIS EI, 1993, J VAC SCI TECHNOL A, V11, P25 MEYER MK, 1996, J AM CERAM SOC, V79, P2763 MEYER MK, 1996, J AM CERAM SOC, V79, P938 MISRA A, 1999, SCRIPTA MATER, V40, P191 MOORE CE, 1949, ATOMIC ENERGY LEVELS, V1 PANAIOTI TA, 2002, MET SCI HEAT TREAT+, V44, P437 PEARSE RWB, 1976, IDENTIFICATION MOL S RICARD A, 1996, REACTIVE PLASMAS ROSALES I, 2000, INTERMETALLICS, V8, P885 SCHNEIBEL JH, 1999, MAT SCI ENG A-STRUCT, V261, P78 SLOVETSKII DI, 1980, MECH CHEM REACTIONS VASUDEVAN AK, 1992, MAT SCI ENG A-STRUCT, V155, P1 VEPREK S, 1999, J VAC SCI TECHNOL A, V17, P2401 NR 16 TC 3 PU MANEY PUBLISHING PI LEEDS PA HUDSON RD, LEEDS LS9 7DL, ENGLAND SN 0267-0844 J9 SURF ENG JI Surf. Eng. PD APR PY 2005 VL 21 IS 2 BP 139 EP 143 PG 5 SC Materials Science, Coatings & Films GA 945OS UT ISI:000230512600009 ER PT J AU Maldonado-Ruiz, SI Martinez, DI Velasco, A Colas, R TI Wear of white cast irons by impact of direct reduced iron pellets SO WEAR LA English DT Article DE erosion; castings; microstructure; alloyed irons ID HIGH CHROMIUM AB A series of eight experimental white iron castings were subjected to the impact of direct reduced iron pellets at a temperature of 550 degrees C. The samples were cast in permanent moulds following an experimental design in which the ratio of chromium to carbon equivalent, the amount of molybdenum and that of vanadium plus titanium were varied each in two different levels. It was found that the amount of material removed from the samples was related to the chemical composition of the alloys, in such a way that the samples with the higher amounts of molybdenum were the ones that exhibit higher wear. It was observed that the samples that exhibited a high resistance to erosion were those in which the eutectic aggregate had a fine distribution, and with a high proportion of the pre-eutectic carbides above 500 mu m(2). A mechanism that relates these experimental observations is proposed. (c) 2005 Elsevier B.V. All rights reserved. C1 Univ Autonoma Zacatecas, Fac Ingn, Zacatecas 98068, Zac, Mexico. Univ Autonoma Estado Morelos, Doctorado Ciencia & Ingn Mat, Cuernavaca, Morelos, Mexico. Univ Autonoma Neuvo Leon, Fac Ingn Mecan & Elect, San Nicolas de Los Garza 66451, NL, Mexico. Nemak, Garcia, NL, Mexico. RP Martinez, DI, Av Pedro Alba S-N Cd, San Nicolas de Los Garza 66451, NL, Mexico. EM dorairma@gama.fime.uanl.mx CR HEINE RW, 1967, PRINCIPLES METAL CAS HUTCHINS M, 1979, ASTM, V66, P59 KNOP K, 1997, METALL PLANT TECHN I, V20, P50 MALDONADORUIZ SI, 2003, INT J CAST METAL RES, V15, P589 MALDONADORUIZ SI, 2004, MATER SCI TECH-LOND, V20, P393 PECKNER D, 1977, HDB STAINLESS STEEL PEREZUNZUETA AJ, 1998, ASTM, V1362, P1137 RODRIGUEZ J, 2003, MATER CHARACT, V51, P95 STEFFEN R, 2004, REV METALL-PARIS, V101, P171 THORPE WR, 1993, METALL T A, V24, P981 TILLY GP, 1979, TREATISE MATERIALS S, V13, P287 VANDERVOORT GF, 1985, MET PROG, V127, P31 NR 12 TC 0 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0043-1648 J9 WEAR JI Wear PD JUL-AUG PY 2005 VL 259 IS 1-6 PN Part 1 Sp. Iss. SI BP 361 EP 366 PG 6 SC Engineering, Mechanical; Materials Science, Multidisciplinary GA 943EJ UT ISI:000230334800043 ER PT J AU Mahalingam, T Chitra, JSP Chu, JP Velumani, S Sebastian, PJ TI Structural and annealing studies of potentiostatically deposited Cu2O thin films SO SOLAR ENERGY MATERIALS AND SOLAR CELLS LA English DT Article DE Cu2O films; structural properties; photoelectrochemical solar cells AB Cuprous oxide (Cu2O) thin films were deposited on Cu and tin oxide coated glass substrates through potentiostatic electrodeposition. The optimum range of deposition parameters was experimentally investigated. X-ray diffraction studies revealed the formation of single-phase cubic Cu2O films in the deposition potential range from -0.355 to -0.555 V versus SCE. Studies revealed that an optimum pH of 9.0 yielded single-phase cubic films with improved crystallinity. The preferential orientation of (200) cubic Cu2O peak was found to increase with bath temperature in the range 30-70 degrees C. The effects of annealing on the preferred orientation, grain size and optical band gap were studied. The energy conversion efficiencies of as-deposited and annealed p-Cu2O films as photocathodes in photoelectrochemical (PEC) solar cells were studied and the results were discussed. (c) 2004 Elsevier B.V. All rights reserved. C1 Alagappa Univ, Dept Phys, Karaikkudi 630003, Tamil Nadu, India. Natl Taiwan Ocean Univ, Inst Mat Engn, Chilung 202, Taiwan. Inst Mexicano Petr, Programa Invest & Desarrollo Ductos, Mexico City 07730, DF, Mexico. UNAM, Energy Res Ctr, Solar H2 Fuel Cell Grp, Temixco 62580, Morelos, Mexico. RP Mahalingam, T, Alagappa Univ, Dept Phys, Karaikkudi 630003, Tamil Nadu, India. EM tmaha51@yahoo.com CR ABUZEID ME, 1986, PHYS STATUS SOLIDI A, V93, P613 BOUNDAR FA, 1978, THIN SOLID FILMS, V55, P201 FERNANDO CAN, 2000, SOL ENERG MAT SOL C, V63, P299 FUJINAKA M, 1983, J APPL PHYS, V54, P3582 GUILLEN C, 1991, SOL ENERG MATER, V23, P31 JANDA M, 1976, PHYS STATUS SOLIDI A, V35, P391 JAYEWARDENA C, 1998, SOL ENERG MAT SOL C, V56, P29 KOSUGI T, 1998, J AM CERAM SOC, V81, P3117 MUKHOPADHYAY AK, 1992, THIN SOLID FILMS, V209, P92 OGALE SB, 1992, J APPL PHYS, V72, P3765 ROOS A, 1983, SOL ENERG MATER, V7, P467 SANTRA K, 1999, SOL ENERG MAT SOL C, V57, P345 NR 12 TC 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0927-0248 J9 SOLAR ENERG MATER SOLAR CELLS JI Sol. Energy Mater. Sol. Cells PD JUL 15 PY 2005 VL 88 IS 2 BP 209 EP 216 PG 8 SC Energy & Fuels; Materials Science, Multidisciplinary GA 942BE UT ISI:000230257100009 ER PT J AU Mahalingam, T John, VS Raja, M Su, YK Sebastian, PJ TI Electrodeposition and characterization of transparent ZnO thin films SO SOLAR ENERGY MATERIALS AND SOLAR CELLS LA English DT Article DE zinc oxide; wurtzite structure; X-ray diffraction; optical properties; surface morphology ID ZINC-OXIDE FILMS; ELECTROCHEMICAL DEPOSITION AB Thin films of zinc oxide (ZnO) have been grown by potentiostatic cathodic deposition onto tin oxide-coated glass from a simple aqueous zinc nitrate electrolyte. Cyclic voltammetry (CV) experiments were performed to determine the reaction kinetics of the species. The various optimum deposition parameters like potential, pH and bath temperature are found to be -1.1 V (SCE), 5 +/- 0.1 and 80 degrees C, respectively. Structural characterization by X-ray diffraction indicates the formation of ZnO film with a preferred c-axis orientation and exhibits the wurtzite structure. Optical studies revealed a band gap energy 3.32 eV which is characteristic of ZnO films. SEM micrographs show a compact structure with nodular appearance, which is in agreement with the reported value of ZnO and the results are discussed. (c) 2004 Elsevier B.V. All rights reserved. C1 Alagappa Univ, Dept Phys, Karaikkudi 630003, Tamil Nadu, India. Natl Cheng Kung Univ, Dept Elect Engn, Inst Microelect, Tainan 70101, Taiwan. UNAM, CIE, Solar Hydrogen Fuel Cell Grp, Temixco 62580, Morelos, Mexico. RP Mahalingam, T, Alagappa Univ, Dept Phys, Karaikkudi 630003, Tamil Nadu, India. EM maha51@lycos.com CR BONASEWICZ P, 1986, THIN SOLID FILMS, V142, P77 GAL D, 2000, THIN SOLID FILMS, V361, P79 GHOSH A, 1991, MATER CHEM PHYS, V27, P45 GOPALASWAMY H, 1990, SEMICOND SCI TECH, V5, P980 GU ZH, 1999, J ELECTROCHEM SOC, V146, P156 IKEDA T, 1994, SOL ENERG MAT SOL C, V34, P379 IZAKI M, 1996, APPL PHYS LETT, V68, P2439 IZAKI M, 1996, J ELECTROCHEM SOC, V143, L53 KATAYAMA J, 2000, J APPL ELECTROCHEM, V30, P855 KUROYANAGI A, 1989, JPN J APPL PHYS PT 1, V28, P219 MAHNMOOD FS, 1995, THIN SOLID FILMS, V270, P376 NUNES P, 2001, THIN SOLID FILMS, V383, P277 PEULON S, 1996, ADV MATER, V8, P166 ROTH AP, 1981, SOLID STATE COMMUN, V39, P1269 SANG B, 1996, JPN J APPL PHYS, V35, P602 STOTT L, 1993, APPL PHYS LETT, V62, P597 WENAS WW, 1994, J APPL PHYS, V33, P283 NR 17 TC 5 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0927-0248 J9 SOLAR ENERG MATER SOLAR CELLS JI Sol. Energy Mater. Sol. Cells PD JUL 15 PY 2005 VL 88 IS 2 BP 227 EP 235 PG 9 SC Energy & Fuels; Materials Science, Multidisciplinary GA 942BE UT ISI:000230257100011 ER PT J AU Bindu, K Campos, J Nair, MTS Sanchez, A Nair, PK TI Semiconducting AgSbSe2 thin film and its application in a photovoltaic structure SO SEMICONDUCTOR SCIENCE AND TECHNOLOGY LA English DT Article ID CHEMICAL BATH DEPOSITION AB Thin films of AgSbSe2 have been prepared by heating a Sb2S3-Ag stack, with the Ag side in contact with a chemically deposited Se thin film, which served as a planar-source,of Se. vapour. A two-state, process,consisting of the formation of an Ag2Se film through the reaction of a vacuum deposited Ag film in the Se vapour at about 80 degrees C, and its reaction at 300 degrees C with a chemically deposited Sb2S3 film, results in the formation of the AgSbSe2 film. X-ray diffraction studies illustrate the structural evolution in the formation of this film. The material possesses an indirect optical band gap of about 0.9 eV. Thermoelectric measurements on the films showed a Seebeck coefficient of 500 mu V K-1 (p-type), and thus a hole concentration of similar to 10(22) m(-3). The feasibility of application of these films as a photovoltaic absorber material is illustrated for the structure SnO2-CdS-(i)Sb2S3(p)AgSbSe2, in which an open circuit voltage of 530 mV has been observed under an intensity of illumination of 2 kW m(-2) using a tungsten-halogen lamp. C1 Univ Nacl Autonoma Mexico, Ctr Invest Energia, Dept Solar Energy Mat, Temixco 62580, Morelos, Mexico. RP Bindu, K, Univ Nacl Autonoma Mexico, Ctr Invest Energia, Dept Solar Energy Mat, Temixco 62580, Morelos, Mexico. CR BINDU K, MAT RES SOC S P BINDU K, 2002, SEMICOND SCI TECH, V17, P270 BINDU K, 2004, SEMICOND SCI TECH, V19, P1348 ELZAHED H, 1994, THIN SOLID FILMS, V238, P104 GEORGE PJ, 1995, APPL PHYS LETT, V152, P150 KUMAR SR, 1999, J ALLOY COMPD, V285, P48 MADELUNG O, 1992, SEMICONDUCTORS OTHER, P72 NAIR MTS, 1994, J APPL PHYS, V75, P1557 NAIR MTS, 1998, J ELECTROCHEM SOC, V145, P2113 NAIR PK, 1998, SOL ENERG MAT SOL C, V52, P313 PATEL AR, 1982, THIN SOLID FILMS, V94, P51 PATEL AR, 1982, THIN SOLID FILMS, V98, P59 RAMANATHAN K, 2003, J PHYS CHEM SOLIDS, V64, P1495 RODERIGUEZLAZCA.Y, 2001, J CRYST GROWTH, V223, P399 SHAHANE GS, 2001, MATER CHEM PHYS, V70, P112 SMITH RA, 1978, SEMICONDUCTORS+, P153 SOLIMAN HS, 1998, J PHYS-CONDENS MAT, V10, P847 SZE SM, 1981, PHYS SEMICONDUCTORS NR 18 TC 6 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0268-1242 J9 SEMICOND SCI TECHNOL JI Semicond. Sci. Technol. PD JUN PY 2005 VL 20 IS 6 BP 496 EP 504 PG 9 SC Engineering, Electrical & Electronic; Materials Science, Multidisciplinary; Physics, Condensed Matter GA 942CO UT ISI:000230260700005 ER PT J AU Rodriguez, AN Nair, MTS Nair, PK TI Structural, optical and electrical properties of chemically deposited silver sulfide thin films SO SEMICONDUCTOR SCIENCE AND TECHNOLOGY LA English DT Article ID BATH DEPOSITION; SOLUTION GROWTH; AG2S FILMS; ORGANOSILANES; SUBSTRATE; BI2S3 AB Ag2S thin films of 90-300 nm thickness were deposited in 3-8 h at 60-70 degrees C on glass substrates from a chemical bath containing silver nitrate, sodium thiosulfate and dimethylthiourea (DMTU) or tetramethylthiourea (TMTU). The glass substrates used for this purpose were previously immersed in a chemical deposition bath to deposit a ZnS thin film of 40 nm thickness in the case of the bath with DMTU or subjected to a pretreatment in a methanol solution of 3-(trimethoxysilyl)propyl.methacrylate for deposition from the TMTU bath. Thin film yield is > 40% for the TMTU bath, when the deposition produces 60 nm films at a substrate separation of 0.4 mm, and is about 30% for film thicknesses of 90-300, nm for both baths at a substrate separation of 1-5 mm. X-ray diffraction patterns similar to that of the mineral acanthite (Ag2S) are observed in the case of the films heated in nitrogen at temperatures 100-200 degrees C; heating at 300-400 degrees C leads to freezing-in of the high temperature phase, argentite. Films annealed at 300 degrees C possess a direct (forbidden) optical band gap of about 1.0 eV. Typical electrical conductivity of the films is 10(-3) (Omega cm)(-1). A photosensitivity of approximately 100 is observed in films annealed at 200 degrees C, under an intensity of illumination 2 kW m(-2) from a tungsten halogen lamp. Mobility-lifetime product is of the order of 10(-5) cm(2) V-1, which suggests a free carrier lifetime of about 0.1 As. C1 Univ Nacl Autonoma Mexico, Ctr Invest Energia, Dept Solar Energy Mat, Temixco 62580, Morelos, Mexico. RP Rodriguez, AN, Univ Nacl Autonoma Mexico, Ctr Invest Energia, Dept Solar Energy Mat, Temixco 62580, Morelos, Mexico. EM pkn@cie.unam.mx CR ALLEN KW, 1992, SILANES OTHER COUPLI, P81 ARIASCREADIGOS A, 2000, SEMICOND SCI TECH, V15, P1022 CHOPRA KL, 1982, PHYS THIN FILMS, V12, P201 DARLING P, 1991, CRYSTAL IDENTIFIER, P70 DHUMURE SS, 1991, MATER CHEM PHYS, V27, P321 DHUMURE SS, 1991, MATER CHEM PHYS, V28, P141 GROZDANOV I, 1994, SEMICOND SCI TECH, V9, P1234 HERZBERG G, 1945, ATOMIC SPECTRA ATOMI, P28 HUANG L, 1995, PHOSPHORUS SULFUR, V105, P175 HUANG L, 1995, THIN SOLID FILMS, V268, P49 KITAEV GA, 1967, IZV AKAD SSSR NEORG, V3, P1080 KRAUS W, 2000, POWDERCELL WINDOWS V LOKHANDE CD, 1991, MATER CHEM PHYS, V27, P1 MADELUNG O, 1992, SEMICONDUCTORS GROUP, P13 MANE RS, 2000, MATER CHEM PHYS, V65, P1 MEHERZIMAGHRAOUI H, 1996, THIN SOLID FILMS, V288, P217 MICHELETTI FB, 1967, APPL PHYS LETT, V10, P136 NAIR MTS, 1998, SEMICOND SCI TECH, V13, P1164 NAIR PK, 1992, SEMICOND SCI TECH, V7, P239 NAIR PK, 1999, J CRYST GROWTH, V206, P68 NAIR PK, 2001, SEMICOND SCI TECH, V16, P855 ORTON JW, 1982, J APPL PHYS, V53, P1602 PANKOVE JI, 1975, OPTICAL PROCESSES SE, P36 RAI BK, 1997, J APPL PHYS, V82, P1310 SANDMAN DJ, 1982, ORGANOMETALLICS, V1, P739 SMITH RA, 1978, SEMICONDUCTORS+, P309 VARKEY AJ, 1991, SOL ENERG MATER, V21, P291 NR 27 TC 3 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0268-1242 J9 SEMICOND SCI TECHNOL JI Semicond. Sci. Technol. PD JUN PY 2005 VL 20 IS 6 BP 576 EP 585 PG 10 SC Engineering, Electrical & Electronic; Materials Science, Multidisciplinary; Physics, Condensed Matter GA 942CO UT ISI:000230260700018 ER PT J AU Espitia-Cabrera, I Contreras-Garcia, ME Bartolo-Perez, P Pena, JL Reyes-Gasga, J Martinez, L TI Coverings of zirconia deposited by electrophoresis on steel 316L SO REVISTA MEXICANA DE FISICA LA Spanish DT Article DE Zirconia; electrophoretic deposition; coatings; XPS ID COATINGS; OXIDES; ZRO2 AB The present research involved zirconia coatings prepared using electrophoretic deposition (EPD) on 316L stainless steel, via hydrolysis of ZrOCl2 aqueous solution. Initially, a first zircoma thin film was obtained and treated at 400 degrees C for consolidation. Then a second zirconia film was deposited to obtain a homogeneous and fully covered 316L stainless steel plate. The XPS analyses show that on the first zirconia film, the elements Fe, Cr, O and Zr are present. In this first film the compounds Cr2O3, Fe2O3 and ZrO2 are formed. While in the second film only the Zr and O are observed so that the surface is formed by ZrO2. C1 Univ Michoacana San Nicolas Hidalgo, Fac Ingn Quim, Morelia 58060, Michoacan, Mexico. Univ Michoacana San Nicolas Hidalgo, Inst Invest Met, Morelia, Michoacan, Mexico. Inst Politecn Nacl, Ctr Invest & Estudios Avanzados, Dept Fis Apl, Merida 97310, Venezuela. Univ Nacl Autonoma Mexico, Inst Fis, Mexico City, DF, Mexico. Univ Nacl Autonoma Mexico, Ctr Ciencias Fis, Cuernavaca, Morelos, Mexico. RP Espitia-Cabrera, I, Univ Michoacana San Nicolas Hidalgo, Fac Ingn Quim, Morelia 58060, Michoacan, Mexico. EM pascual@mda.cinvestav.na CR CHO BO, 2001, J VAC SCI TECHNOL A, V19, P2751 DEDEBNATH, 1999, J AM CERA SOC, V82, P3031 DIMAGGIO R, 1997, SURF COAT TECH, V89, P292 FERRARI B, 1998, BOL SOC ESP CERAM V, V37, P369 MOON J, 2002, SURF COAT TECH, V155, P1 SARKARY P, 1996, J AM CERAM SOC, V79, P1997 STEVENS R, 1986, INTRO ZIRCONIA ZIRCO SUZUKI S, 2000, SURF INTERFACE ANAL, V30, P372 TANABE K, 1994, CATAL TODAY, V20, P185 WAGNER CD, 1979, HDB XRAY PHOTOELECTR ZHITOMIRSKY I, 2000, J EUR CERAM SOC, V20, P2055 NR 11 TC 0 PU SOCIEDAD MEXICANA DE FISICA PI COYOACAN PA APARTADO POSTAL 70-348, COYOACAN 04511, MEXICO SN 0035-001X J9 REV MEX FIS JI Rev. Mex. Fis. PD JUN PY 2005 VL 51 IS 3 BP 311 EP 315 PG 5 SC Physics, Multidisciplinary GA 939WC UT ISI:000230102300014 ER PT J AU Saint-Martin, H Hernandez-Cobos, J Ortega-Blake, I TI Water models based on a single potential energy surface and different molecular degrees of freedom SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID MOBILE CHARGE-DENSITIES; AB-INITIO CALCULATIONS; TRANSFERABLE INTERACTION MODELS; STATIC DIELECTRIC-CONSTANT; HARMONIC-OSCILLATORS MODEL; POLARIZABLE FORCE-FIELDS; MONTE-CARLO SIMULATIONS; LIQUID WATER; FLUCTUATING CHARGE; 1ST PRINCIPLES AB Up to now it has not been possible to neatly assess whether a deficient performance of a model is due to poor parametrization of the force field or the lack of inclusion of enough molecular properties. This work compares several molecular models in the framework of the same force field, which was designed to include many-body nonadditive effects: (a) a polarizable and flexible molecule with constraints that account for the quantal nature of the vibration [B. Hess, H. Saint-Martin, and H. J. C. Berendsen, J. Chem. Phys. 116, 9602 (2002), H. Saint-Martin, B. Hess, and H. J. C. Berendsen, J. Chem. Phys. 120, 11133 (2004)], (b) a polarizable and classically flexible molecule [H. Saint-Martin, J. Hernandez-Cobos, M. I. Bernal-Uruchurtu, I. Ortega-Blake, and H. J. C. Berendsen, J. Chem. Phys. 113, 10899 (2000)], (c) a polarizable and rigid molecule, and finally (d) a nonpolarizable and rigid molecule. The goal is to determine how significant the different molecular properties are. The results indicate that all factors-nonadditivity, polarizability, and intramolecular flexibility-are important. Still, approximations can be made in order to diminish the computational cost of the simulations with a small decrease in the accuracy of the predictions, provided that those approximations are counterbalanced by the proper inclusion of an effective molecular property, that is, an average molecular geometry or an average dipole. Hence instead of building an effective force field by parametrizing it in order to reproduce the properties of a specific phase, a building approach is proposed that is based on adequately restricting the molecular flexibility and/or polarizability of a model potential fitted to unimolecular properties, pair interactions, and many-body nonadditive contributions. In this manner, the same parental model can be used to simulate the same substance under a wide range of thermodynamic conditions. An additional advantage of this approach is that, as the force field improves by the quality of the molecular calculations, all levels of modeling can be improved. C1 Univ Nacl Autonoma Mexico, Ctr Ciencias Fis, Cuernavaca 62251, Morelos, Mexico. Ctr Invest & Estudios Avanzados, Unidad Merida, Dept Fis Aplicada, Merida 97310, Yucatan, Mexico. RP Saint-Martin, H, Univ Nacl Autonoma Mexico, Ctr Ciencias Fis, Apartado Postal 48-3, Cuernavaca 62251, Morelos, Mexico. EM hstmartin@fis.unam.mx CR ALFREDSSON M, 1998, MOL PHYS, V94, P873 ALLESCH M, 2004, J CHEM PHYS, V120, P5192 BADYAL YS, 2000, J CHEM PHYS, V112, P9206 BENEDICT WS, 1956, J CHEM PHYS, V24, P1139 BERENDSEN HJC, 1981, INTERMOLECULAR FORCE, P331 BERENDSEN HJC, 1987, J PHYS CHEM-US, V91, P6269 BRODHOLT J, 1995, MOL PHYS, V85, P81 BRODSKY A, 1996, CHEM PHYS LETT, V261, P563 BUCKINGHAM AD, 1956, P ROY SOC LOND A MAT, V238, P235 BURNHAM CJ, 1999, J CHEM PHYS, V110, P4566 BURNHAM CJ, 2002, J CHEM PHYS, V116, P1479 BURSULAYA BD, 1998, J CHEM PHYS, V108, P3277 CAR R, 1985, PHYS REV LETT, V55, P2471 CARRILLOTRIPP M, 2003, J CHEM PHYS, V118, P7062 CHEN B, 2000, J PHYS CHEM B, V104, P2378 CHIALVO AA, 1996, J CHEM PHYS, V105, P8274 CLOUGH SA, 1973, J CHEM PHYS, V59, P2254 FERNANDEZ DP, 1995, J PHYS CHEM REF DATA, V24, P33 FINNEY JL, 2001, J MOL LIQ, V90, P303 FLYVBJERG H, 1989, J CHEM PHYS, V91, P461 GIESE TJ, 2004, J CHEM PHYS, V120, P9903 GROENENBOOM GC, 2000, PHYS REV LETT, V84, P4072 GUILLOT B, 2001, J CHEM PHYS, V114, P6720 GUILLOT B, 2002, J MOL LIQ, V101, P219 HALLE B, 1981, J CHEM PHYS, V75, P1928 HASTED JB, 1972, WATER COMPREHENSIVE, V1, P255 HERNANDEZCOBOS J, IN PRESS J CHEM PHYS HESS B, 2002, J CHEM PHYS, V116, P9602 HOCHTL P, 1998, J CHEM PHYS, V109, P4927 HODGES MP, 1997, J PHYS CHEM A, V101, P9163 HUNENBERGER PH, 1998, J CHEM PHYS, V108, P6117 ICHIKAWA K, 1991, MOL PHYS, V73, P79 JORGENSEN WL, 1983, J CHEM PHYS, V79, P926 KAMINSKI GA, 2004, J PHYS CHEM A, V108, P621 KELL GS, 1975, J CHEM ENG DATA, V20, P97 KIM J, 1998, J CHEM PHYS, V109, P5886 KIRKWOOD JG, 1939, J CHEM PHYS, V7, P911 KLOPPER W, 1922, PHYS CHEM CHEM PHYS, P2 KRYNICKI K, 1978, FARADAY DISCUSS, V66, P199 LAASONEN K, 1993, J CHEM PHYS, V99, P9080 LAMOUREUX G, 2003, J CHEM PHYS, V119, P5185 MAHONEY MW, 2000, J CHEM PHYS, V112, P8910 MARTIN MG, 1998, J CHEM PHYS, V108, P3383 MATSUOKA O, 1976, J CHEM PHYS, V64, P2314 MORIARTY NW, 1997, J CHEM PHYS, V106, P6470 MORITA A, 2002, J COMPUT CHEM, V23, P1466 NEUMANN M, 1983, CHEM PHYS LETT, V95, P417 NEUMANN M, 1984, CHEM PHYS LETT, V106, P563 NIESAR U, 1990, J PHYS CHEM-US, V94, P7949 NYMAND TM, 1997, J PHYS CHEM A, V101, P10039 PARTRIDGE H, 1997, J CHEM PHYS, V106, P4618 PASTOR N, 1993, J CHEM PHYS, V99, P7899 RICK SW, 1994, J CHEM PHYS, V101, P6141 SAINTMARTIN H, 1990, J CHEM PHYS, V93, P6448 SAINTMARTIN H, 2000, J CHEM PHYS, V113, P10899 SAINTMARTIN H, 2004, J CHEM PHYS, V120, P11133 SATO H, 1988, J PHYS CHEM REF DATA, V17, P1439 SATO H, 1999, J CHEM PHYS, V111, P8545 SILVESTRELLI PL, 1999, J CHEM PHYS, V111, P3572 SOPER AK, 2000, CHEM PHYS, V258, P121 SOPER AK, 2001, MOL PHYS, V99, P1503 SPRIK M, 1991, J CHEM PHYS, V95, P6762 STERN HA, 2001, J CHEM PHYS, V115, P2237 STERN HA, 2001, J CHEM PHYS, V115, P7622 THIESSEN WE, 1982, J CHEM PHYS, V77, P2656 VECHI SM, 2002, J BRAZIL CHEM SOC, V13, P583 WALLQVIST A, 1999, REV COMP CH, V13, P183 WU Y, 2004, J PHYS CHEM A, V108, P7563 XANTHEAS SS, 2002, J CHEM PHYS, V116, P1493 NR 69 TC 4 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD JUN 8 PY 2005 VL 122 IS 22 AR 224509 DI ARTN 224509 PG 12 SC Physics, Atomic, Molecular & Chemical GA 936LW UT ISI:000229858500051 ER PT J AU Mendez-Montealvo, G Solorza-Feria, J del Valle, MV Gomez-Montiel, N Paredes-Lopez, Y Bello-Perez, LA TI Chemical composition and calorimetric characterization of hybrids and varieties of maize cultivated in Mexico SO AGROCIENCIA LA Spanish DT Article DE starch; thermal behavior; chemical composition; gelatinization; hybrids ID THERMAL-PROPERTIES; RESISTANT STARCH; GELATINIZATION; LINES; RETROGRADATION; AMYLOPECTIN; HYDROLYSIS; GENOTYPES; PRODUCTS; TORTILLA AB A study was made of the chemical composition and thermal behavior of twenty maize hybrids and varieties generated through a breeding program of the INIFAP-Iguala, Mexico. The semicristalline and crystalline maize grains had a lower moisture content than those of the semidented and dented types, which in turn, had the highest values of protein. The quality protein maize (QPM) varieties did not have the highest content of protein. Differential scanning calorimetry (DSC) analysis showed gelatinization temperature values ranging from 73.4 to 77.1 degrees C and enthalpy values between 1.9-4.7 J g(-1). This result is important for the design of equipment used for the cooking or thermal treatment of maize grain, as well as in the production of tortillas. C1 IPN, Ctr Desarrollo Prod Biot, Yautepec 62731, Morelos, Mexico. IPN, Inst Nacl Invest Forestales Agr & Pecuarias, Guanajuato 45000, Mexico. IPN, Ctr Invest & Estudios Avanzados, Guanajuato 45000, Mexico. RP Mendez-Montealvo, G, IPN, Ctr Desarrollo Prod Biot, Apartado Postal 24, Yautepec 62731, Morelos, Mexico. EM labellop@ipn.mx CR *AACC, 2000, APPR METH AACC *AOAC, 1990, OFF METH AN, V2 ARMSTRONG CL, 2000, TRANSGENIC CEREALS, P115 ASP NG, 1996, NUTR RES REV, V9, P1 BILIADERIS CG, 1991, CAN J PHYSIOL PHARM, V69, P60 CAMPUSBAYPOLI ON, 1999, STARCH-STARKE, V51, P173 DESINIBALDI ACB, 2001, ARCH LATINOAM NUTR, V51, P86 DUBOIS M, 1956, ANAL CHEM, V28, P350 ENGLYST HN, 1992, EUR J CLIN NUTR S2, V46, P33 FOX E, 1995, SIGMA STAT USER MANU GARCIAALONSO A, 1999, FOOD CHEM, V66, P181 GONI I, 1996, FOOD CHEM, V56, P445 GONI I, 1997, NUTR RES, V17, P427 GONZALEZREYES E, 2003, CARBOHYD POLYM, V52, P297 HOLM J, 1986, STARCH-STARKE, V38, P224 JI Y, 2003, CARBOHYD POLYM, V51, P439 KRIEGER KM, 1998, CEREAL CHEM, V75, P656 NG KY, 1997, CEREAL CHEM, V74, P288 NG KY, 1997, CEREAL CHEM, V74, P837 PAREDESLOPEZ O, 1994, FOOD CHEM, V50, P411 PAREDESLOPEZ O, 2000, ALIMENTOS MAGICOS CU, P18 RENDONVILLALOBOS R, 2002, CEREAL CHEM, V79, P340 SALINASMORENO Y, 2003, AGROCIENCIA-MEXICO, V37, P617 SKRABANJA V, 1999, J AGR FOOD CHEM, V47, P2033 TOVAR J, 1992, J NUTR, V122, P1500 WATSON SA, 1987, CORN CHEM TECHNOLOGY, P125 WATSON SA, 1987, CORN CHEM TECHNOLOGY, P53 YUAN RC, 1993, CEREAL CHEM, V70, P81 YUAN RC, 1998, CEREAL CHEM, V75, P117 ZAZUETAMORALES JJ, 2001, J SCI FOOD AGR, V81, P1379 NR 30 TC 3 PU COLEGIO DE POSTGRADUADOS PI TEXCOCO PA PO BOX 199, TEXCOCO 56190, MEXICO SN 1405-3195 J9 AGROCIENCIA JI Agrociencia PD MAY-JUN PY 2005 VL 39 IS 3 BP 267 EP 274 PG 8 SC Agriculture, Multidisciplinary GA 935CN UT ISI:000229757000003 ER PT J AU Ojeda-Robertos, NF Mendoza-de Gives, P Torres-Acosta, JFJ Rodriguez-Vivas, RI Aguilar-Caballero, AJ TI Evaluating the effectiveness of a Mexican strain of Duddingtonia flagrans as a biological control agent against gastrointestinal nematodes in goat faeces SO JOURNAL OF HELMINTHOLOGY LA English DT Article ID FREE-LIVING STAGES; NEMATOPHAGOUS FUNGI; INFECTIVE LARVAE; PARASITIC NEMATODES; HAEMONCHUS-CONTORTUS; SHEEP; EFFICACY; CHLAMYDOSPORES; FIELD; PLOT AB The use of Duddingtonia flagrans in the control of goat nematodes was investigated. Initially, the time of passage of chlamydospores through the digestive tract of goats was evaluated. Two groups of seven parasite-free kids were formed. Group A received a single dose of 3.5x10(6) D. flagrans chlamydospores (FTHO-8 strain) per kg of live weight. Group B did not receive any chlamydospores. Faeces were obtained from each kid daily from day 4 prior to inoculation until day 5 post-inoculation (PI) and were placed in Petri dishes containing water agar. Gastrointestinal nematode infective larvae were added to each Petri dish and incubated at 25 degrees C for 7 days. Petri dishes were examined to detect the fungus and trapped nematodes. A second trial evaluated the effect of D. flagrans on the number of gastrointestinal nematode larvae harvested from goat faecal cultures in naturally infected goats. Two groups of seven goats were formed. The treated group received a single dose of 3.5x10(6) D. flagrans chlamydospores per kg of liveweight. The control group did not receive any chlamydospores. Faeces were obtained twice daily from each kid. Two faecal cultures were made for each kid. One was incubated for 7 days and the other for 14 days. Gastrointestinal nematode larvae were recovered from each culture and counted. Percentage of larval development reduction was determined using a ratio of larvae/eggs deposited in the control and treated groups. Duddingtonia flagrans survived the digestive process of goats, and maintained its predatory activity, being observed from 21 to 81 h PI (3 to 4 days). A reduction in the infective larvae population in the treated group compared to the non-treated group was observed in both incubation periods (7 days: 5.3-36.0%; 14 days: 0-52.8%, P > 0.05). Although a single inoculation of D. flagrans can induce a reduction of infective larvae collected from faeces, a different scheme of dosing may be needed to enhance the efficacy of D. flagrans in goats. C1 Univ Autonoma Yucatan, Fac Med Vet & Zootecn, Merida, Yucatan, Mexico. INIFAP, Disciplinarias Parasitol Vet, Ctr Nacl Invest, Jiutepec 062550, Morelos, Mexico. RP Torres-Acosta, JFJ, Univ Autonoma Yucatan, Fac Med Vet & Zootecn, Km 15-5 Carretera, Merida, Yucatan, Mexico. EM tacosta@tunku.uady.mx CR *MAFF, 1986, MAN VET PAR LAB TECH, P1 BARRON GL, 1977, TOPICS MYCOBIOLOGY, V1 BOWMAN DD, 1999, GEORGIS PARASITOLOGY, P303 CHANDRAWATHANI P, 2003, VET PARASITOL, V117, P173 CHANDRAWATHANI P, 2004, VET PARASITOL, V120, P177 CHARTIER C, 2003, VET RES, V34, P221 CHAUHAN JB, 2002, INDIAN J VET PARASIT, V16, P17 COOKE RC, 1964, T BRIT MYCOL SOC, V47, P61 DEGIVES PM, 1998, J HELMINTHOL, V72, P343 DEGIVES PM, 2005, IN PRESS SMALL RUMIN FAEDO M, 1997, VET PARASITOL, V72, P149 FERNANDEZ AS, 1997, VET PARASITOL, V73, P257 FERNANDEZ AS, 1999, PARASITOL RES, V85, P661 HOSTE H, 2000, CONTROL GASTROINTEST, P32 KNOX MR, 2001, VET PARASITOL, V101, P155 LARSEN M, 1995, VET PARASITOL, V60, P321 LARSEN M, 1998, VET PARASITOL, V76, P121 LARSEN M, 1999, INT J PARASITOL, V29, P139 LARSEN M, 2000, PARASITOLOGY S, V120, S121 LLERANDIJUAREZ RD, 1998, J HELMINTHOL, V72, P155 PARAUD C, 2003, PARASITOL RES, V89, P102 PARAUD C, 2004, SMALL RUMINANT RES, V55, P199 PENA MT, 2002, VET PARASITOL, V103, P259 RODRIGUEZ VRI, 1994, TECNICAS DIAGNOSTICA, P78 ROSSANIGO CE, 1995, J HELMINTHOL, V69, P357 SANYAL PK, 2002, INDIAN J ANIM SCI, V72, P215 TERRILL TH, 2004, VET PARASITOL, V120, P285 THAMSBORG SM, 1999, VET PARASITOL, V84, P169 TORRESACOSTA JF, 1999, THESIS U LONDON TORRESACOSTA JF, 2002, 17 REUN NAC CAPR DUR, P210 TORRESACOSTA JF, 2003, REV BIOMEDICA, V14, P75 ULLOA M, 1978, ATLAS MICOLOGIA BASI VANSOEST PJ, 1994, NUTR ECOLOGY RUMINAN, P230 WAGHORN TS, 2003, VET PARASITOL, V118, P227 WALLER PJ, 2001, VET PARASITOL, V102, P321 WRIGHT DA, 2003, VET PARASITOL, V118, P61 NR 36 TC 0 PU CABI PUBLISHING PI WALLINGFORD PA C/O PUBLISHING DIVISION, NOSWORTHY WAY, WALLINGFORD OX10 8DE, OXON, ENGLAND SN 0022-149X J9 J HELMINTHOL JI J. Helminthol. PD JUN PY 2005 VL 79 IS 2 BP 151 EP 157 PG 7 SC Parasitology; Zoology GA 934AS UT ISI:000229679500009 ER PT J AU Morales, R Albiter, A Salazar, M Tavera, FJ Escudero, R Gonzalez-Rodriguez, JG TI Corrosion behavior of uniaxially cold-pressed Fe2MO intermetallic in 0.5M H2SO4 SO MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING LA English DT Article DE aqueous corrosion; Fe2Mo intermetallic; electrochemical techniques ID ELECTROCHEMICAL NOISE-ANALYSIS; ALLOYS; SPECTROSCOPY; FILMS AB The effect of sintering pressure and temperature on the corrosion resistance of uniaxially cold-pressed FeMo intermetallic alloy in 0.5M H2SO4 has been evaluated using electrochemical techniques at room temperature. The intermetallic Fe2MO powder was sintered at 750 degrees C at 607, 884 and 1223 MPa and at 900 degrees C at 480, 540, 822, 873 and 1040 MPa to produce different porosities. Electrochemical techniques included potentiodynamic polarization curves, electrochemical noise in Current, evolution of the free corrosion potential (E-corr) with time and linear polarization resistance to know the change of the corrosion rate with time. Results showed that all the; alloys showed a passive region of several hundreds of millivolts wide, and that, regardless the compacting pressure or temperature, practically neither the E-corr nor the anodic current density values were affected by these variables, which rapidly reached a steady-state value. At 750 degrees C, the corrosion rate increased as the sintering pressure decreased, probably due to the retention of electrolyte inside the porous. At T = 900 degrees C, this was not so evident, but it followed a similar tendency. Thus, the electrochemical noise reading showed that precisely at the lowest compacting pressure for 750 degrees C, where is expected the highest porosity density, the corrosion type is a localized one, probably pitting, whereas in all the other compacting conditions, where a lower porosity density is expected, the corrosion type is uniform generalized one. (c) 2005 Published by Elsevier B.V. C1 Univ Autonoma Estado Morelos, FCQI, CIICAP, Cuernavaca 62210, Morelos, Mexico. Univ Michoacana, Inst Invest Quim Biol, Morelia 58240, Michoacan, Mexico. Inst Mexicano Petr, Mexico City 07730, DF, Mexico. RP Gonzalez-Rodriguez, JG, Univ Autonoma Estado Morelos, FCQI, CIICAP, Av Univ 1001,Col Chamilpa, Cuernavaca 62210, Morelos, Mexico. EM ggonzalez@uaem.mx CR AMBROSE TR, 1983, TREATISE MAT SCI TEC, V123 CLAYTON CR, 1989, CORROS SCI, V29, P881 COSCIA M, 2003, MATER PERFORMANCE, V27, P52 GABRIELLI C, 1986, ELECTROCHIM ACTA, V31, P1025 HARA N, 1979, J ELECTROCHEM SOC, V126, P1328 HASHIMOTO K, 1979, CORROS SCI, V19, P857 HAZZA MI, 1997, DESALINATION, V95, P199 HDLAKY K, 1981, CORROS SCI, V21, P317 HDLAKY K, 1982, CORROS SCI, V22, P231 ITAGAKI M, 1997, CORROS SCI, V40, P1255 MANSFELD F, 1993, J ELECTROCHEM SOC, V140, P2205 MCDONALD DD, 1992, J ELECTROCHEM SOC, V139, P3434 MORALES R, 2002, J MATER RES, V17, P1954 MORALES R, 2003, METALL MATER TRANS B, V34, P661 POURBAIX M, 1973, LECT ELECTROCHEMICAL ROBIN A, 2003, CORROS ENG SCI TECH, V38, P205 STEARN M, 1958, J ELECTROCHEM SOC, V105, P638 STOUT DA, 1979, CORROSION, V35, P165 THIERRY D, 1991, CORROS SCI, V32, P273 NR 19 TC 0 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0921-5093 J9 MATER SCI ENG A-STRUCT MATER JI Mater. Sci. Eng. A-Struct. Mater. Prop. Microstruct. Process. PD APR 25 PY 2005 VL 397 IS 1-2 BP 1 EP 7 PG 7 SC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary GA 929WO UT ISI:000229377500001 ER PT J AU Hernandez-Abarca, JT Otero-Colina, G Vera-Graziano, J Carrillo-Sanchez, JL Alvarado-Rosales, D Aranda-Escobar, E TI Life tables and thermal constants of Pediculaster mesembrinae (Acari : Siteroptidae) fed on the fungus, Trichoderma harzianum rifai SO INTERNATIONAL JOURNAL OF ACAROLOGY LA English DT Article AB Life and fecundity table studies on Pediculaster mesembrinae (Canestrini) (Acari: Siteroptidae) were conducted under controlled conditions (15, 20, 25 and 30 degrees C, relative humidity 60 +/- 5%), using cohorts of 40 individually confined mites in observation arenas. Fermented wheat straw (compost) previously inoculated with Trichoderma harzianum Rifai spores was used as substrate and food source. The study started with mite eggs approximately 5 h old. The life cycle of P. mesembrinae included the stages of egg, larva, quiescent larva or nymphocrysalis, and adult; only females were observed in our population. The length of the life cycle, as well as total longevity, showed an inverse (linear) relation with temperature. Values of r(m) (intrinsic rate of increase) were 0.146, 0.132, 0.170 and 0.204, for 15, 20, 25 and 30 degrees C, respectively. Developmental rates had a direct and linear relationship with temperature; and threshold temperatures ranged between -0.53 and -3.22 degrees C. Development from egg to adult required 152 degree days. C1 Colegio Postgrad, Inst Fitosanidad, Programa Entomol & Acarol, Mexico City 56230, DF, Mexico. Colegio Postgrad, Inst Fitosanidad, Programa Fitopatol, Mexico City, DF, Mexico. Univ Autonoma Estado Morelos, Ctr Invest & Biotecnol, Cuernavaca 62210, Morelos, Mexico. RP Hernandez-Abarca, JT, Colegio Postgrad, Inst Fitosanidad, Programa Entomol & Acarol, Km 36-5, Mexico City 56230, DF, Mexico. EM gotero@colpos.mx CR ARNOLD CY, 1959, P AM SOC HORTIC SCI, V74, P430 CAMERIK AM, 1995, MITTEL HAMB ZOOL MUS, V92, P73 CAMERIK AM, 2004, FAUNA EUROPAEA ACARI CLIFT AD, 1995, SCI CULTIVATION EDIB, P507 CROSS EA, 1988, ENVIRON ENTOMOL, V17, P309 DELILLO E, 1990, PROFESSIONE AGR, V2, P132 DELILLO E, 1997, ENTOMOLOGICA BARI, V31, P7 DELILLO E, 1998, ACAROLOGY, P243 DELILLO E, 1998, AGR RICERCA, V176, P71 FERRAGUT F, 1997, B SAN VEG PLAGAS, V23, P301 GURNEY B, 1967, ACAROLOGIA, V9, P353 KOSIR M, 1975, PEDOBIOLOGIA, V15, P313 KREBS CJ, 1985, EXPT ANAL DISTRIBUTI, P123 LINDQUIST EE, 1986, MEM ENTOMOL SOC CAN, V136, P1 LOTKA AJ, 1907, AM J SCI, V24, P199 LOTKA AJ, 1913, J WASH ACAD SCI, V3, P241 MENDEZ RI, 2000, PROTOCOLO INVESTIGAC MOSER JC, 1975, ANN ENTOMOLOGICAL SO, V68, P820 SABELIS MW, 1985, SPIDER MITES THEIR A, V1, P265 SMILEY RL, 1978, INT J ACAROL, V4, P125 VEDDER PJC, 1986, CULTIVO MODERNO CAMP VERA GJ, 1991, AGROCIENCIA SERIE PR, V2, P7 VERA GJ, 2002, ECOLOGIA POBLACIONES WICHT HC, 1971, ENTOMOL NEWS, V82, P83 WRENSCH DA, 1985, SPIDER MITES THEIR B, P165 NR 25 TC 0 PU INDIRA PUBLISHING HOUSE PI WEST BLOOMFIELD PA P O BOX 250456, WEST BLOOMFIELD, MI 48325-0456 USA SN 0164-7954 J9 INT J ACAROL JI Int. J. Acarol. PD JUN PY 2005 VL 31 IS 2 BP 165 EP 170 PG 6 SC Entomology GA 930VW UT ISI:000229446200012 ER PT J AU Calixto-Rodriguez, M Tiburcio-Silver, A Ortiz, A Sanchez-Juarez, A TI Optoelectronical properties of indium sulfide thin films prepared by spray pyrolysis for photovoltaic applications SO THIN SOLID FILMS LA English DT Article DE indium sulfide; spray pyrolysis; solar cell ID BETA-IN2S3 AB Indium sulfide (In2S3) thin films have been prepared by the spray pyrolysis (SP) technique using indium acetate and N-N dimethyl thiourea as precursor compounds. Samples prepared at different temperatures and atomic ratio of In to S in the starting solution, (In/S)(sol), have been characterized using several techniques. X-ray diffraction studies have shown that the preparation temperature (T-p) affects the crystallinity of the deposited materials as well as the optoelectronic properties. For (In/S)(sol)=1/8, the optical band gap (E,) increases from 2.2 up to 2.67 eV when T-p increases from 250 up to 450 degrees C. For (In/S)(sol)=1 and T-p=450 degrees C, the deposited material shows n-type electrical conductivity with a dark value of 1 (Omega cm)(-1), and E-g=2.04 eV. The In2S3 thin films prepared under these conditions have a big potential use as a window material for photovoltaic heterojunction devices. (c) 2004 Published by Elsevier B.V. C1 UAEM, CIICAp, Cuernavaca, Morelos, Mexico. UNAM, CIE, Temixco 62580, Morelos, Mexico. UNAM, IIM, Mexico City, DF, Mexico. RP Tiburcio-Silver, A, UAEM, CIICAp, Cuernavaca, Morelos, Mexico. EM atsilver@yahoo.com CR BARREAU N, 2003, THIN SOLID FILMS, V431, P326 BHIRA L, 2000, PHYS STATUS SOLIDI A, V181, P427 BOUGUILA N, 1997, J PHYS III, V7, P1647 CHOE SH, 2001, SEMICOND SCI TECH, V16, P98 CHOPRA KL, 1983, THIN FILMS SOLAR CEL JOHN TT, 2003, SEMICOND SCI TECH, V18, P491 JUAREZ AS, 1995, THESIS FACULTAD CIEN KAZMERSKI LL, 1980, POLYCRYSTALLINE AMOR KIM CD, 1993, THIN SOLID FILMS, V224, P69 KIM WT, 1986, J APPL PHYS, V60, P2631 MADELUNG O, 1992, DATA SCI TECHNOLOGY MAISSEL LI, 1970, HDB THIN FILM TECHNO MOSS TS, 1959, OPTICAL PROPERTIES S NAIR PK, 1998, SOL ENERG MAT SOL C, V52, P313 OKTIK S, 1988, PROG CRYST GROWTH CH, V17, P171 RUNYAN WR, 1975, SEMICONDUCTOR MEASUR, P145 VOSSEN JL, 1978, THIN FILMS PROCESSES NR 17 TC 5 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0040-6090 J9 THIN SOLID FILMS JI Thin Solid Films PD JUN 1 PY 2005 VL 480 SI Sp. Iss. SI BP 133 EP 137 PG 5 SC Materials Science, Multidisciplinary; Materials Science, Coatings & Films; Physics, Applied; Physics, Condensed Matter GA 927DW UT ISI:000229173600027 ER PT J AU Santoyo, E Garcia, R Aparicio, A Verma, SP Verma, MP TI Evaluation of capillary electrophoresis for determining the concentration of dissolved silica in geothermal brines SO JOURNAL OF CHROMATOGRAPHY A LA English DT Article DE hydrothermal waters; separation methods; silica scaling; geochemistry; silicates; linear regression ID WATER; CHROMATOGRAPHY; ANIONS; SAMPLES AB The determination of silica concentrations in geothermal brines is widely recognized as a difficult analytical task due to its complex chemical polymerization kinetics that occurs during sample collection and chemical analysis. Capillary electrophoresis (CE) has been evaluated as a new reliable analytical method to measure silica (as silicates) in geothermal brines. Synthetic and geothermal brine samples were used to evaluate CE methodology. A capillary electrophoresis instrument, Quanta 4000 (Waters-Millipore) coupled with a Waters 820 workstation was used to carry out the experimental work. The separation of silicates was completed in similar to 5.5 min using a conventional fused-silica capillary (75 mu m i.d. x 375 mu m o.d. x 60 cm total length). A hydrostatic injection (10 cm for 20 s at 25 degrees C) was employed for introducing the samples. The carrier electrolyte consisted of 10 mM sodium chromate, 3 mM tetradecyltrimethyl-ammonium hydroxide (TTAOH), 2 mM sodium carbonate, and 1 mM sodium hydroxide, adjusted to a pH 11.0 +/- 0.1. Silicates were determined using an indirect UV detection at a wavelength of 254 run with a mercury lamp and with a negative power supply (-15 kV). A good reproducibility in the migration times (%R.S.D. similar to 1.6%) based on six non-consecutive injections of synthetic brine solutions was obtained. A linear response between silica concentration and corrected peak area was observed. Ordinary (OLR) and weighted (WLR) linear regression models were used for calculating silica concentrations in all samples using the corresponding fitted calibration curves. The analytical results of CE were finally compared with the most probable values of synthetic reference standards of silica using the Student's t-test. No significant differences were found between them at P = 0.01. Similarly, the atomic absorption spectrometry (AAS) results were also compared with the most probable concentrations of the same reference standards, finding significant differences at P = 0.01. (c) 2004 Elsevier B.V. All rights reserved. C1 Univ Nacl Autonoma Mexico, Ctr Invest & Energia, Temixco 62580, Mor, Mexico. CSIC, Dept Volcanol, Madrid 28006, Spain. Inst Invest Elect, Unidad Geotermia, Cuernavaca 62001, Morelos, Mexico. RP Santoyo, E, Univ Nacl Autonoma Mexico, Ctr Invest & Energia, Priv Xochicalco Sno,Apto Postal 34, Temixco 62580, Mor, Mexico. EM esg@cie.unam.mx CR *APHA, 1992, STAND METH EX WAT WA *ASTM, 1990, ANN BOOK ASTM STAND *DION, 1989, DION APPL UPD AU, V113, P1 *DION, 2003, 03168805 DION, P10 BAKER DR, 1995, CAPILLARY ELECTROPHO BARCIELAALONSO MC, 2000, ANAL CHIM ACTA, V416, P21 BARRAGAN RM, 1991, GEOTERMIA REV MEX GE, V7, P23 BEVINGTON PR, 1969, DATA REDUCTION ERROR BURGUERA M, 2002, TALANTA, V58, P1157 DOBLE P, 1999, J CHROMATOGR A, V834, P189 FUJIWARA K, 1996, ANAL LETT, V29, P1985 GEROGE S, 2000, CHEMOSPHERE, V40, P57 GIACOMELLI MC, 1999, ANAL CHIM ACTA, V396, P285 HARAKUWE AH, 1999, J CHROMATOGR A, V834, P213 HIOKI A, 2000, ANAL CHIM ACTA, V416, P21 ILR RK, 1979, CHEM SILICA LANGMUIR D, 1997, AQUEOUS ENV GEOCHEMI LI HB, 2000, J CHROMATOGR A, V874, P143 LICO MS, 1988, US GEOLOGICAL SURVEY LONG GL, 1983, ANAL CHEM, V55, P713 MERCADO S, 1985, GEOTH RES COUNCIL T, V9, P263 MILLER JN, 2000, STAT CHEMOMETRICS AN NICHOLSON K, 1993, GEOTHERMAL FLUIDS CH POTAPOV VV, 2002, THEOR FOUND CHEM ENG, V36, P589 ROTHBAUM HP, 1979, GEOTHERMICS, V8, P1 SANTOYO E, 2001, J CHROMATOGR A, V920, P325 SANTOYO E, 2003, J CHROMATOGR A, V997, P171 VERMA MP, 2002, GEOTHERMICS, V31, P677 VERMA SP, 1997, J VOLCANOL GEOTH RES, V79, P9 VERMA SP, 2000, CHEM GEOL, V164, P35 WESTON A, 1997, HPLC CE PRINCIPLES P WILSHIRE JP, 1983, LC, V1, P290 XU Q, 2001, CHROMATOGRAPHIA, V53, P81 ZHANG JZ, 1999, WATER RES, V33, P2879 NR 34 TC 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0021-9673 J9 J CHROMATOGR A JI J. Chromatogr. A PD APR 15 PY 2005 VL 1071 IS 1-2 BP 197 EP 204 PG 8 SC Biochemical Research Methods; Chemistry, Analytical GA 916QS UT ISI:000228401300029 ER PT J AU Aguilar, A Emmons, ED Gharaibeh, MF Covington, AM Bozek, JD Ackerman, G Canton, S Rude, B Schlachter, AS Hinojosa, G Alvarez, I Cisneros, C McLaughlin, BM Phaneuf, RA TI Photoionization of ions of the nitrogen isoelectronic sequence: experiment and theory for F2+ and Ne3+ SO JOURNAL OF PHYSICS B-ATOMIC MOLECULAR AND OPTICAL PHYSICS LA English DT Article ID X-RAY SPECTROSCOPY; CROSS-SECTIONS; RADIATIVE RECOMBINATION; OSCILLATOR-STRENGTHS; HIGH-RESOLUTION; TRANSITIONS; HELIUM; OXYGEN; STATES AB Absolute photoionization measurements are reported for admixtures of the ground and metastable states of F2+ from 56.3 eV to 75.6 eV, and of Ne3+ from 89.3 eV to 113.8 eV. The S-4 degrees ground-state and the D-2 degrees and P-2 degrees metastable-state fractions present in the primary ion beams were estimated from photoion yield measurements near their respective threshold energies. Most of the observed resonance structure has been spectroscopically assigned. The measurements are compared with new R-matrix theoretical calculations and with those in the TOPbase astrophysical database. The systematic behaviour of the quantum-defect parameter is analysed as a function of the nuclear charge for four Rydberg series observed in both species, and compared to published data for O+ and N. C1 Univ Nevada, Dept Phys, Reno, NV 89557 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. Univ Nacl Autonoma Mexico, Ctr Ciencias Fis, Cuernavaca 62131, Morelos, Mexico. Harvard Smithsonian Ctr Astrophys, Inst Theoret Atom & Mol Phys, Cambridge, MA 02138 USA. Queens Univ Belfast, Sch Math & Phys, Belfast BT7 1NN, Antrim, North Ireland. RP Aguilar, A, NIST, Atom Phys Div, 100 Bur Dr,Stop 8421, Gaithersburg, MD 20899 USA. EM phaneuf@physics.unr.edu CR AGGARWAL KM, 1998, ASTROPHYS J SUPPL S, V118, P589 AGGARWAL KM, 2001, ASTROPHYS J SUPPL S, V136, P763 AGUILAR A, 2003, ASTROPHYS J SUPPL S, V146, P467 AGUILAR A, 2003, PHYS REV A, V67 BERRINGTON KA, 1995, COMPUT PHYS COMMUN, V92, P290 BROETZ F, 2001, PHYS SCRIPTA T, V92, P278 BURKE PG, 1993, ATOMIC MOL PROCESSES CARR SS, 1993, GEOPHYS RES LETT, V20, P2035 CHAMPEAUX JP, 2003, ASTROPHYS J SUPPL S, V148, P583 CONDON E, 1980, ATOMIC STRUCTURE COVINGTON AM, 2001, PHYS REV LETT, V87 CUNTO W, 1993, ASTRON ASTROPHYS, V275, P5 DOMKE M, 1996, PHYS REV A, V53, P1424 GOULD RJ, 1978, ASTROPHYS J, V219, P250 GUDEL M, 2001, ASTRON ASTROPHYS, V365, L336 HUDSON E, 1993, PHYS REV A, V47, P361 JENKINS EB, 2000, ASTROPHYS J LETT, V358, L81 JOHN TL, 1974, J QUANT SPECTROSC RA, V14, P777 LEVENSON NA, 2002, ASTROPHYS J 1, V576, P798 MARTIN WC, 2004, NIST ATOMIC SPECTRA MEIER RR, 1991, SPACE SCI REV, V58, P1 MELENDEZALVIRA DJ, 1999, J GEOPHYS RES-SPACE, V104, P14901 NAHAR SN, 2004, PHYS REV A, V69 PRADHAN AK, 1980, MON NOT R ASTRON SOC, V190, P5 RAJU PK, 1990, ASTROPHYS SPACE SCI, V173, P13 ROBICHEAUX F, 1995, PHYS REV A, V52, P1319 WEST JB, 2001, J PHYS B ATOM MOL PH, V34, P45 WEST JB, 2004, RADIAT PHYS CHEM, V70, P275 NR 28 TC 3 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0953-4075 J9 J PHYS-B-AT MOL OPT PHYS JI J. Phys. B-At. Mol. Opt. Phys. PD FEB 28 PY 2005 VL 38 IS 4 BP 343 EP 361 PG 19 SC Optics; Physics, Atomic, Molecular & Chemical GA 914TD UT ISI:000228249700004 ER PT J AU Castrellon-Uribe, J TI Experimental results of the performance of a laser fiber as a remote sensor of temperature SO OPTICS AND LASERS IN ENGINEERING LA English DT Article DE temperature sensor; erbium-doped fiber; fluorescence spectral bands ID SILICA FIBER; FLUORESCENCE AB We present experimental results demonstrating the performance of an erbium-doped silica fiber as a remote temperature sensor. The sensor is based on the fluorescence intensity-ratio change of two spectral bands as a function of temperature in the wavelength interval from 515 to 570 nm. We apply a radiometric analysis to the fluorescence spectrum that we have measured to determine the optimal spectral bands to use in the power ratio of the sensor. The spectral bands used in the power ratio, with best performance, are 525-535 nm/555-565 nm, with a signal-noise ratio of 57 and 56 dB, respectively. The sensor sensitivity is about 10 x 10(-3)/1 degrees C, and the resolutio'n is approximately 0.06 degrees C. (C) 2004 Elsevier Ltd. All rights reserved. C1 UAEM, Ctr Invest Ingn & Ciencias Aplicadas, CIICAp, Cuernavaca 62210, Morelos, Mexico. RP Castrellon-Uribe, J, UAEM, Ctr Invest Ingn & Ciencias Aplicadas, CIICAp, Av Univ 1001,Col Chamilpa, Cuernavaca 62210, Morelos, Mexico. EM jcastrellon@mexico.com CR CASTRELLON J, 1999, P SOC PHOTO-OPT INS, V3759, P410 CASTRELLON J, 2002, INFRARED PHYS TECHN, V43, P219 CASTRELLON J, 2002, OPT ENG, V41, P1255 DESURVIRE E, 1994, ERBIUM DOPED FIBER A FARRIES MC, 1986, ELECTRON LETT, V22, P418 MAURICE E, 1994, OPT LETT, V19, P990 MAURICE E, 1997, APPL OPTICS, V36, P8264 SUN T, 1997, REV SCI INSTRUM, V68, P3447 WICKERSHEIM KA, 1990, SPIE, V1267, P84 ZHANG ZY, 1998, REV SCI INSTRUM, V69, P3210 NR 10 TC 1 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0143-8166 J9 OPT LASER ENG JI Opt. Lasers Eng. PD JUN PY 2005 VL 43 IS 6 BP 633 EP 644 PG 12 SC Optics GA 910WB UT ISI:000227961800003 ER PT J AU Hernandez, JI Best, R Dorantes, RJ Estrada, CA TI Study of a solar booster assisted ejector refrigeration system with R134a SO JOURNAL OF SOLAR ENERGY ENGINEERING-TRANSACTIONS OF THE ASME LA English DT Article DE ejector compression; refrigeration; cooling; low temperature energy; efficient use of energy ID LOW-GRADE HEAT AB The studies of ejector refrigeration systems employing refrigerant R134a for air conditioning are scarce and nonexistent for ice making when its potential application in developing countries will lessen their refrigeration needs. So, a parametric study for an ice making solar booster assisted ejector refrigeration system operating with R134a is carried out. System energy and exergy efficiencies as well as ejector efficiency are presented as a function of generator and condenser temperatures and booster discharge pressure. A discussion on maximum ejector efficiency and its effect in system behavior is also carried out. With results indicating that for an evaporator temperature of -10 degrees C, the system can operate at a generator temperature of 85 degrees C with average energy efficiencies between 0.21 and 0.58, depending on the condenser temperature. Consequently, these systems could be a solution for solar refrigeration using off-the-shelf components. C1 UNAM, Ctr Invest Energia, Temixco 62580, Morelos, Mexico. UAM Azcapotzalco, Dept Energy, Mexico City 02200, DF, Mexico. RP Hernandez, JI, UNAM, Ctr Invest Energia, Apdo Postal 34, Temixco 62580, Morelos, Mexico. EM jhg@cie.unam.mx rbb@cie.unam.mx rjdr@correo.azc.uam.mx cestrada@cie.unam.mx CR DORANTES R, 1996, APPL THERM ENG, V16, P669 LU LT, 1984, THESIS INSA LYON FRA MOONEY DA, 1955, INTRO THERMODYNAMICS, P279 NAHDI E, 1993, INT J REFRIG, V16, P67 SOKOLOV M, 1990, INT J REFRIG, V13, P351 SOKOLOV M, 1990, INT J REFRIG, V13, P357 NR 6 TC 0 PU ASME-AMER SOC MECHANICAL ENG PI NEW YORK PA THREE PARK AVE, NEW YORK, NY 10016-5990 USA SN 0199-6231 J9 J SOL ENERGY ENG JI J. Sol. Energy Eng. Trans.-ASME PD FEB PY 2005 VL 127 IS 1 BP 53 EP 59 PG 7 SC Energy & Fuels; Engineering, Mechanical GA 905OI UT ISI:000227577800008 ER PT J AU Garcia-Sanchez, A Padilla-Martinez, II Martinez-Martinez, FJ Hopfl, H Garcia-Baez, EV TI 1,1,2,2-tetrachloro-1,2-diphenylethane SO ACTA CRYSTALLOGRAPHICA SECTION E-STRUCTURE REPORTS ONLINE LA English DT Article ID X-RAY; CONFORMATIONAL PREFERENCES; INTERNAL-ROTATION; ORGANIC-COMPOUNDS; DERIVATIVES; DATABASE; H-1 AB The title compound, C14H10Cl4, Possesses C-i symmetry and crystallizes with one half-molecule in the asymmetric unit. The two phenyl rings are antiperiplanar and inclined to one, another by 180degrees by symmetry. The central C-C bond distance and the Cl-C-Cl bond angle [1.5887 (18) Angstrom and 106.02 (7)degrees, respectively] are significantly different from ideal sp(3) values. In the crystal, a supramolecular structure is achieved by soft parallel-displaced pi-pi stacking and C-H...pi intermolecular interactions. C1 Inst Politecn Nacl, Unidad Profes Interdisciplinaria Biotecnol, Mexico City 07340, DF, Mexico. Univ Autonoma Estado Morelos, Ctr Invest Quim, Cuernavaca, Morelos, Mexico. RP Garcia-Baez, EV, Inst Politecn Nacl, Unidad Profes Interdisciplinaria Biotecnol, Ave Acueducto S-N,Barrio La Laguna Ticoman, Mexico City 07340, DF, Mexico. EM vgarcia@acei.upibi.ipn.mx CR *BRUK AXS INC, 2000, SMART SAINT SHELXTL ALLEN FH, 1987, J CHEM SOC P2, S1 ALLEN FH, 2002, ACTA CRYSTALLOGR B 3, V58, P380 ANTOLINI L, 1994, J CHEM SOC P2, P1107 ANTOLINI L, 1995, J CHEM SOC P2, P1007 CORNIA A, 1993, J CHEM SOC PERK OCT, P1847 FARRUGIA LJ, 1999, J APPL CRYSTALLOGR, V32, P837 HOVMOLLER S, 1978, ACTA CRYSTALLOGR B, V34, P3016 SHELDRICK GM, 1997, SHELXS97 SHELXL97 SINGH J, 1990, J MOL BIOL, V211, P595 UMEZAWA Y, 1998, B CHEM SOC JPN, V71, P1207 NR 11 TC 0 PU BLACKWELL MUNKSGAARD PI COPENHAGEN PA 35 NORRE SOGADE, PO BOX 2148, DK-1016 COPENHAGEN, DENMARK SN 1600-5368 J9 ACTA CRYSTALLOGR E-STRUCT REP JI Acta Crystallogr. Sect. E.-Struct Rep. Online PD MAR PY 2005 VL 61 PN Part 3 BP O678 EP O680 PG 3 SC Crystallography GA 902ST UT ISI:000227377500151 ER PT J AU Martinez-Martinez, FJ Rojas-Perez, RE Garcia-Baez, EV Hopfl, H Padilla-Martinez, II TI Diethyl piperazine-1,4-diyldioxalate SO ACTA CRYSTALLOGRAPHICA SECTION C-CRYSTAL STRUCTURE COMMUNICATIONS LA English DT Article ID CRYSTAL-STRUCTURES; BOND AB The ethyl oxamate group, N-C(O)-C(O)-OEt, in the title compound, alternatively called diethyl N,N':N,N'-bis(ethylene)dioxamate, C12H18N2O6, can be considered as being composed of two singly bonded amide and ester functionalities. The ethyl oxamate group is not planar. The two carbonyl groups are almost perpendicular, with an oxalyl O=C-C=O torsion angle of. 111.34 (17)degrees. The molecule is located on an inversion centre. Infinite supramolecular tapes, propagating along the b axis, are formed through soft C-H...O interactions which form a centrosymmetric R-2(2)(12) motif. C1 Inst Politecn Nacl, Unidad Profes Interdisciplinaria Biotecnol, Mexico City 07340, DF, Mexico. Univ Autonoma Estado Morelos, Ctr Invest Quim, Cuernavaca, Morelos, Mexico. RP Padilla-Martinez, II, Inst Politecn Nacl, Unidad Profes Interdisciplinaria Biotecnol, Ave Acueducto S-N,Barrio La Laguna Ticoman, Mexico City 07340, DF, Mexico. EM ipadilla@acei.upibi.ipn.mx CR *BRUK AXS INC, 2000, SMART VERS 5 054 SAI ALLEN FH, 1987, J CHEM SOC P2, V2, P1 ALLEN FH, 2002, ACTA CRYSTALLOGR B 3, V58, P380 ANDERSEN HS, 2002, J MED CHEM, V45, P4443 BERNSTEIN J, 1995, ANGEW CHEM INT EDIT, V34, P1555 BONDI A, 1964, J PHYS CHEM-US, V68, P441 DESIRAJU GR, 1996, ACCOUNTS CHEM RES, V29, P441 DEWAR MJS, 1960, TETRAHEDRON, V11, P96 FARRUGIA LJ, 1999, J APPL CRYSTALLOGR, V32, P837 GARCIABAEZ EV, 2003, ACTA CRYSTALLOGR 10, V59, O541 MARTIN S, 2002, ACTA CRYSTALLOGR E 8, V58, O913 MARTINEZMARTINEZ FJ, 1998, J CHEM SOC PERK FEB, P401 PADILLAMARTINEZ II, 2001, J CHEM SOC PERK SEP, P1817 PADILLAMARTINEZ II, 2003, ACTA CRYSTALLOGR E 6, V59, O825 SHELDRICK GM, 1997, SHELXS97 SHELXL97 TODA F, 1986, B CHEM SOC JPN, V59, P1189 VENKATRAMANI L, 1994, INT J PEPT PROT RES, V43, P520 NR 17 TC 3 PU BLACKWELL MUNKSGAARD PI COPENHAGEN PA 35 NORRE SOGADE, PO BOX 2148, DK-1016 COPENHAGEN, DENMARK SN 0108-2701 J9 ACTA CRYSTALLOGR C-CRYST STR JI Acta Crystallogr. Sect. C-Cryst. Struct. Commun. PD SEP PY 2004 VL 60 PN Part 9 BP O699 EP O701 PG 3 SC Crystallography GA 858XT UT ISI:000224226700047 ER PT J AU Brito-Arias, MA Garcia-Baez, EV del Toro, GV Hopfl, H TI (E)-3-Nitrobenzaldehyde O-acetyloxime SO ACTA CRYSTALLOGRAPHICA SECTION E-STRUCTURE REPORTS ONLINE LA English DT Article AB In the title compound, C9H8N2O4, the 3-nitrobenzaldehyde oxime and acetyl group have a dihedral angle of 19.5 (4)degrees. The acetyl carbonyl and 3-nitrobenzaldehyde oxime groups both adopt a trans configuration (E). In the crystal structure, molecules are linked by a series of weak intermolecular C-H...O interactions, forming a sheet-like structure parallel to the (303) plane. C1 Inst Politecn Nacl, Unidad Profes Interdisciplinaria Biotecnol, Mexico City 07340, DF, Mexico. Univ Autonoma Estado Morelos, Ctr Invest Quim, Cuernavaca, Morelos, Mexico. RP Garcia-Baez, EV, Inst Politecn Nacl, Unidad Profes Interdisciplinaria Biotecnol, Ave Acueducto S-N,Barrio Laguna Ticoman, Mexico City 07340, DF, Mexico. EM vgarcia@acei.upibi.ipn.mx CR *BRUK AXS INC, 2000, SMART SAINT SHELXTL FARRUGIA LJ, 1999, J APPL CRYSTALLOGR, V32, P837 SHELDRICK GM, 1997, SHELXS97 SHELXL97 TAGA T, 1987, ACTA CRYSTALLOGR C, V43, P748 NR 4 TC 1 PU BLACKWELL MUNKSGAARD PI COPENHAGEN PA 35 NORRE SOGADE, PO BOX 2148, DK-1016 COPENHAGEN, DENMARK SN 1600-5368 J9 ACTA CRYSTALLOGR E-STRUCT REP JI Acta Crystallogr. Sect. E.-Struct Rep. Online PD JUL PY 2004 VL 60 PN Part 8 BP O1451 EP O1452 PG 2 SC Crystallography GA 843HJ UT ISI:000223069000145 ER PT J AU Jung, C Mejia-Monasterio, C Taylor, HS TI Analysis of an algebraic model for the chromophore vibrations of CF3CHFI SO PHYSICAL CHEMISTRY CHEMICAL PHYSICS LA English DT Article ID BENDING SPECTRUM; CLASSICAL CHAOS; DYNAMICS; ACETYLENE; CHBRCLF; CM(-1); STATE; REDISTRIBUTION; ASSIGNMENT; ENERGY AB We extract the dynamics implicit in an algebraic fitted model Hamiltonian for the hydrogen chromophore's vibrational motion in the molecule CF3CHFI. The original model has four degrees of freedom, a conserved polyad allows the reduction to three degrees of freedom. For most quantum states we can identify the underlying motion that when quantized gives the said state. Most of the classifications, identifications and assignments are done by visual inspection of the already available wave function serniclassically transformed from the number representation to a representation on the reduced dimension toroidal configuration space corresponding to the classical action and angle variables. The concentration of the wave function density to lower dimensional subsets centered on idealized simple lower dimensional organizing structures and the behavior of the phase along such organizing centers already reveals the atomic motion. Extremely little computational work is needed. C1 Univ So Calif, Dept Chem, Los Angeles, CA 90089 USA. UNAM, Ctr Ciencias Fis, Cuernavaca 62251, Morelos, Mexico. RP Taylor, HS, Univ So Calif, Dept Chem, Los Angeles, CA 90089 USA. CR BEIL A, 1994, J CHEM SOC CHEM COMM, V99, P49 BEIL A, 1996, BER BUNSEN PHYS CHEM, V100, P1853 BEIL A, 1997, BER BUNSEN PHYS CHEM, V101, P311 BENET L, 1993, PHYS REV LETT, V71, P529 JACOBSON MP, 1998, J CHEM PHYS, V109, P121 JACOBSON MP, 1999, J CHEM PHYS, V111, P600 JUNG C, 2001, J CHEM PHYS, V115, P2499 JUNG C, 2001, J PHYS CHEM A, V105, P681 JUNG C, 2002, J PHYS CHEM A, V106, P3092 JUNG C, 2004, J CHEM PHYS, V120, P4194 POCHERT J, 2000, J CHEM PHYS, V113, P2719 SIEBERT EL, 1996, J CHEM PHYS, V105, P469 TEFFO JL, 1994, J MOL SPECTROSC, V168, P390 TEMSAMANI MA, 1996, J CHEM PHYS, V105, P11357 TROELLSCH A, 2001, Z PHYS CHEM 2, V215, P207 WAALKENS H, 2002, J PHYS CHEM A, V106, P911 NR 16 TC 2 PU ROYAL SOC CHEMISTRY PI CAMBRIDGE PA THOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLAND SN 1463-9076 J9 PHYS CHEM CHEM PHYS JI Phys. Chem. Chem. Phys. PD JUN 21 PY 2004 VL 6 IS 12 BP 3069 EP 3076 PG 8 SC Chemistry, Physical; Physics, Atomic, Molecular & Chemical GA 839ZG UT ISI:000222826200004 ER PT J AU Gonzalez-Rodriguez, JG Casales, M Espinoza-Medina, MA Angeles-Chavez, C Izquierdo, G Guardian, R TI Microstructural evolution of Alloy 690 during sensitization at 700 degrees C SO MATERIALS CHARACTERIZATION LA English DT Article DE alloy 690; sensitization; microstructure evolution; intergranular corrosion AB A structural characterization of sensitized Alloy 690 has been carried out. Alloy 690 was solution annealed (SA; 1100 degreesC for 30 min, water quenched, WQ) and sensitized at 700 degreesC for 5, 12, 24, 36, 48 and 72 It, followed by water quenched. Techniques employed included scanning electron microscope (SEM), transmission electron microscopy (TEM), X-ray diffraction and corrosion weight-loss tests. It was found that the cubic Cr0.19Fe0.7Ni0.11 phase was the main component in all the conditions. In addition, a grain refinement was observed when the aging time was increased; but after 48 h of aging, a discrete, semicontinuous network of Cr23C6 precipitates was detected by X-ray diffraction, in addition to the NiCrO4, Ni9S8 and (Fe,Ni)(9)S-8 phases found by TEM at the grain boundaries, making this alloy more susceptible to intergranular attack (IGA). After 72 h of aging, chromium continues diffusing, "back-filling" the prior depletion profile, recovering the IGA resistance. (C) 2004 Elsevier Inc. All rights reserved. C1 UAEM, FCQI, Ctr Invest Ingn & Ciencas Aplicadas, Cuernavaca 62210, Morelos, Mexico. UNAM, Ctr Ciencias Fis, Cuernavaca, Morelos, Mexico. Inst Mexicano Petr, Programa Invest & Desarrollo Ductos, Mexico City 07730, DF, Mexico. Inst Invest Elect, Temixco, Morelos, Mexico. RP Gonzalez-Rodriguez, JG, UAEM, FCQI, Ctr Invest Ingn & Ciencas Aplicadas, Av Univ 1001,Col Chamilpa, Cuernavaca 62210, Morelos, Mexico. EM ggonzalez@buzon.uaem.mx CR BAUMEL A, 1964, CORROS SCI, V4, P89 BRIANT CL, 1987, CORROSION, V47, P437 CASALES M, 2000, CORROSION, V56, P1133 DUTTA RS, 1999, BRIT CORROS J, V34, P201 JOE MZ, 1999, BRIT CORROS J, V34, P210 NORRING K, 1991, 5 INT S ENV DEGR MAT, P855 REBAK RB, 2000, ADV MATER PROCESS, P37 THUVANDER M, 2000, MAT SCI ENG A-STRUCT, V281, P96 YUNES CM, 1997, BR CORROS J, V32, P185 NR 9 TC 0 PU ELSEVIER SCIENCE INC PI NEW YORK PA 360 PARK AVE SOUTH, NEW YORK, NY 10010-1710 USA SN 1044-5803 J9 MATER CHARACT JI Mater. Charact. PD DEC PY 2003 VL 51 IS 5 BP 309 EP 314 PG 6 SC Materials Science, Characterization & Testing GA 824LH UT ISI:000221687600005 ER PT J AU Jung, C Mejia-Monasterio, C Taylor, HS TI Spectroscopic interpretation: The high vibrations of CDBrClF SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID BENDING SPECTRUM; CLASSICAL CHAOS; DYNAMICS; ACETYLENE; CHBRCLF; CM(-1); STATE; REDISTRIBUTION; ASSIGNMENT; ENERGY AB We extract the dynamics implicit in an algebraic fitted model Hamiltonian for the deuterium chromophore's vibrational motion in the molecule CDBrClF. The original model has four degrees of freedom, three positions and one representing interbond couplings. A conserved polyad allows in a semiclassical approach the reduction to three degrees of freedom. For most quantum states we can identify the underlying motion that when quantized gives the said state. Most of the classifications, identifications, and assignments are done by visual inspection of the already available wave function semiclassically transformed from the number representation to a representation on the reduced dimension toroidal configuration space corresponding to the classical action and angle variables. The concentration of the wave function density to lower dimensional subsets centered on idealized simple lower dimensional organizing structures and the behavior of the phase along such organizing centers already reveals the atomic motion. Extremely little computational work is needed. (C) 2004 American Institute of Physics. C1 UNAM, Ctr Ciencias Fis, Cuernavaca 62251, Morelos, Mexico. Univ So Calif, Dept Chem, Los Angeles, CA 90089 USA. RP Jung, C, UNAM, Ctr Ciencias Fis, Av Univ, Cuernavaca 62251, Morelos, Mexico. CR BEIL A, 1994, J CHEM SOC CHEM COMM, V99, P49 BEIL A, 1996, BER BUNSEN PHYS CHEM, V100, P1853 BEIL A, 1997, BER BUNSEN PHYS CHEM, V101, P311 BEIL A, 2000, J CHEM PHYS, V113, P2701 BENET L, 1993, PHYS REV LETT, V71, P529 FRIED LE, 1987, J CHEM PHYS, V86, P6270 JACOBSON MP, 1998, J CHEM PHYS, V109, P121 JACOBSON MP, 1999, J CHEM PHYS, V111, P600 JOYEUX M, 1998, J CHEM PHYS, V109, P2111 JOYEUX M, 2002, J PHYS CHEM A, V106, P5407 JUNG C, 2001, J CHEM PHYS, V115, P2499 JUNG C, 2001, J PHYS CHEM A, V105, P681 JUNG C, 2002, J PHYS CHEM A, V106, P3092 SIEBERT EL, 1996, J CHEM PHYS, V105, P469 TEFFO JL, 1994, J MOL SPECTROSC, V168, P390 TEMSAMANI MA, 1996, J CHEM PHYS, V105, P11357 TREOLLSCH A, 2001, Z PHYS CHEM, V215, P207 WAALKENS H, 2002, J PHYS CHEM A, V106, P911 NR 18 TC 9 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD MAR 1 PY 2004 VL 120 IS 9 BP 4194 EP 4206 PG 13 SC Physics, Atomic, Molecular & Chemical GA 777XM UT ISI:000189209200016 ER PT J AU Benet, L Leyvraz, F Seligman, TH TI Wigner-Dyson statistics for a class of integrable models SO PHYSICAL REVIEW E LA English DT Article ID INTERACTING BOSON SYSTEMS; RANDOM-MATRIX ENSEMBLES; SPECTRUM; BEHAVIOR; CHAOS AB We construct an ensemble of second-quantized Hamiltonians with two bosonic degrees of freedom, whose members display with probability one Gaussian orthogonal ensemble (GOE) or Gaussian unitary ensemble (GUE) statistics. Nevertheless, these Hamiltonians have a second integral of motion, namely, the boson number, and thus are integrable. To construct this ensemble we use some "reverse engineering" starting from the fact that n bosons in a two-level system with random interactions have an integrable classical limit by the old Heisenberg association of boson operators to actions and angles. By choosing an n-body random interaction and degenerate levels we end up with GOE or GUE Hamiltonians. Ergodicity of these ensembles completes the example. C1 UNAM, Ctr Ciencias Fis, Cuernavaca 62251, Morelos, Mexico. Ctr Int Ciencias AC, Cuernavaca 62131, Morelos, Mexico. Univ Paris 11, Ctr Sci Orsay, LPTMS, F-91405 Orsay, France. RP Benet, L, UNAM, Ctr Ciencias Fis, Apartado Postal 48-3, Cuernavaca 62251, Morelos, Mexico. CR ANDREEV AV, 1996, PHYS REV LETT, V76, P3947 ASAGA T, 2001, EUROPHYS LETT, V56, P340 ASAGA T, 2002, ANN PHYS-NEW YORK, V298, P229 BENET L, 2003, J PHYS A-MATH GEN, V36, P3569 BENET L, 2003, J PHYS A-MATH GEN, V36, L217 BERRY MV, 1981, ANN PHYS-NEW YORK, V131, P163 BERRY MV, 1984, WAVE PARTICLE DUALIS, P231 BERRY MV, 1985, P ROY SOC LOND A MAT, V400, P229 BOHIGAS O, 1984, PHYS REV LETT, V52, P1 CASATI G, 1980, LETT NUOVO CIMENTO, V28, P279 CHAVDA ND, 2003, PHYS LETT A, V311, P331 FRENCH JB, 1978, PHYS LETT B, V80, P17 GUHR T, 1998, PHYS REP, V299, P189 HEISENBERG W, 1925, Z PHYS, V33, P879 JACOBSON MP, 1999, J CHEM PHYS, V111, P600 KOTA VKB, 2001, PHYS REP, V347, P223 LEYVRAZ F, 1996, P 4 WIGN S, P429 MCDONALD SW, 1979, PHYS REV LETT, V42, P1189 MEHTA ML, 1991, RANDOM MATRICES PATEL K, 2000, PHYS LETT A, V275, P329 WU H, 1990, PHYS REV A, V42, P1027 YAFFE LG, 1982, REV MOD PHYS, V54, P407 NR 22 TC 1 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1063-651X J9 PHYS REV E JI Phys. Rev. E PD OCT PY 2003 VL 68 IS 4 PN Part 2 AR 045201 DI ARTN 045201 PG 3 SC Physics, Fluids & Plasmas; Physics, Mathematical GA 743KP UT ISI:000186571200005 ER PT J AU Vega, R Pinero, D Ramanankandrasana, B Dumas, M Bouteille, B Fleury, A Sciutto, E Larralde, C Fragoso, G TI Population genetic structure of Taenia solium from Madagascar and Mexico: implications for clinical profile diversity and immunological technology SO INTERNATIONAL JOURNAL FOR PARASITOLOGY LA English DT Article DE Taenia solium; cysticercosis; random amplified polymorphic DNA; genetic variability; population structure ID HUMAN CYSTICERCOSIS; CENTRAL-AMERICA; DIAGNOSIS; NEUROCYSTICERCOSIS; CRASSICEPS; PREVALENCE; ANTIGENS; DISEASE; HUMANS; MURINE AB Taenia solium is a cestode parasitic of humans and pigs that strongly impacts on public health in developing countries. Its larvae (cysticercus) lodge in the brain, causing neurocysticercosis, and in other tissues, like skeletal muscle and subcutaneous space, causing extraneuronal cysticercosis. Prevalences of these two clinical manifestations vary greatly among continents. Also, neurocysticercosis may be clinically heterogeneous. ranging from asymptomatic forms to severely incapacitating and even fatal presentation. Further, vaccine design and diagnosis technology have met with difficulties in sensitivity, specificity and reproducibility. Parasite diversity underlying clinical heterogeneity and technological difficulties is little explored. Here, T. solium genetic population structure and diversity was studied by way of random amplified polymorphic DNA in individual cysticerci collected from pigs in Madagascar and two regions in Mexico. The amplification profiles of T solium were also compared with those of the murine cysticercus Taenia crassiceps (ORF strain). We show significant genetic differentiation between Madagascar and Mexico and between regions in Mexico, but less so between cysticerci from different localities in Mexico and none between cysticerci from different tissues from the same pig. We also found restricted genetic variability within populations and gene flow was estimated to be low between populations. Thus, genetic differentiation of T solium suggests that different evolutionary paths have been taken and provides support for its involvement in the differential tissue distribution of cysticerci and varying degrees of severity of the disease. It may also explain difficulties in the development of vaccines and tools for immunodiagnosis. (C) 2003 Australian Society for Parasitology Inc. Published by Elsevier Ltd. All rights reserved. C1 Natl Autonomous Univ Mexico, Inst Invest Biomed, Dept Immunol, Mexico City 04510, DF, Mexico. Natl Autonomous Univ Mexico, Dept Ecol Evolut, Inst Ecol, Mexico City 04510, DF, Mexico. Fac Med Limoges, Inst Epidemiol Neurol & Neurol Trop, F-87025 Limoges, France. Inst Nacl Neurol & Neurocirurg, Mexico City 14269, DF, Mexico. Ctr Int Ciencias, Cuernavaca 62131, Morelos, Mexico. RP Vega, R, Natl Autonomous Univ Mexico, Inst Invest Biomed, Dept Immunol, Circuito Interior S-N,Ciudad Univ, Mexico City 04510, DF, Mexico. 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J. Parasit. PD NOV PY 2003 VL 33 IS 13 BP 1479 EP 1485 PG 7 SC Parasitology GA 740DW UT ISI:000186387500005 ER PT J AU Koenigsberger, G Moffat, AFJ Auer, LH TI Ultraviolet spectroscopy of the massive LMC multiple systems Sk-67 degrees 18 (Br 5) and HD 36402 (Br31) SO REVISTA MEXICANA DE ASTRONOMIA Y ASTROFISICA LA English DT Article DE galaxies : Large Magellanic Cloud; stars : binaries; stars : individual (Sk-67 degrees 18, HD 36402); stars : Wolf-Rayet; ultraviolet : spectra ID WOLF-RAYET STARS; LARGE-MAGELLANIC-CLOUD; ATMOSPHERIC ECLIPSES; COLLIDING WINDS; BINARY HD-5980; SPECTRAL CLASSIFICATION; SUPERGIANTS; EVOLUTION AB Following previous IUE-based spectroscopic studies of WR+O binaries in the Galaxy and in the SMC, we present a similar study of the two systems, Br5 [O3 If* (+O) + O8- B0I(+OB?)] and Br 31 [WC4(+O?) + O8 I:] in the Large Magellanic Cloud. We detect wind eclipse effects in the WC4+O (P = 3.033d) pair in Br 31 similar to, but weaker than those observed in the Small Magellanic Cloud system Sk 188 (WO4+O4 V). A low-amplitude (similar to 40 km s(-1)) variation in the radial velocity of UV photospheric absorption lines and the O V 1371 emission with the 3 day period is detected. The radial velocity variations of the photospheric lines may be due to the superposition of the stationary set of absorption lines belonging to the O8 I: star and a broader set of lines belonging to the O-type companion in the close binary pair. The UV continuum energy distribution of Br 31 also supports the optical results that the system contains at least 3 bright stars, one of which is a late O-type supergiant. Contrasting with Br 31, the absence of significant Si IV 1400 Angstrom emission in the UV spectrum of Br 5 contradicts the results from optical spectroscopy that imply that it is triple, with the presence of a late O-type supergiant in the system. Orbital phase-coverage of the IUE observations does not allow the detection of possible atmospheric eclipse effects in Br 5, with P = 2.001 d, but radial velocity variations attributable to orbital motion of the O3 If* star axe detected. C1 UNAM, Ctr Ciencias Fis, Cuernavaca, Morelos, Mexico. Univ Montreal, Dept Phys, Montreal, PQ H3C 3A7, Canada. Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Koenigsberger, G, UNAM, Ctr Ciencias Fis, Apdo Postal 48-3, Cuernavaca, Morelos, Mexico. 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Mex. Astron. Astrofis. PD OCT PY 2003 VL 39 IS 2 BP 213 EP 223 PG 11 SC Astronomy & Astrophysics GA 734NN UT ISI:000186062800007 ER PT J AU Yamamoto, Y Espinasa, L Stock, DW Jeffery, WR TI Development and evolution of craniofacial patterning is mediated by eye-dependent and -independent processes in the cavefish Astyanax SO EVOLUTION & DEVELOPMENT LA English DT Article ID DEGENERATION; MEXICANUS; LENS AB We studied the development and evolution of craniofacial features in the teleost fish, Astyanax mexicanus. This species has an eyed surface dwelling form (surface fish) and many different cave dwelling forms (cavefish) with various degrees of reduced eyes and pigmentation. The craniofacial features we examined are the tooth-bearing maxillary bones, the nasal and antorbital bones, the circumorbital bones, and the opercular bones, all of which show evolutionary modifications in different cavefish populations. Manipulations of eye formation by transplantation of the embryonic lens, by lentectomy, or by removing the optic vesicle showed that eye-dependent and -independent processes change both the surface fish and cavefish craniofacial skeletons. The size of the olfactory pits, which the nasal and antorbital bones define, and the size and positioning of the circumorbital bones were found to correlate with eye development. For the six suborbital bones (SO1 - 6), the relationship with the developing eye appears to be due to ossification initiated from foci in the suborbital canal of cranial neuromasts, whose patterning is also highly correlated with the presence or absence of an eye. By contrast, we found that the number of maxillary teeth, the number of SO3 bone elements, the positioning of SO4 - 6 with respect to the opercular bone, and the shape of the opercular bone are not dependent on eye formation and vary among different cavefish populations. The results suggest that evolution of the cavefish craniofacial skeleton is controlled by multiple developmental events, some a direct consequence of eye degeneration and others unrelated to loss of the eye. C1 Univ Maryland, Dept Biol, College Pk, MD 20742 USA. Univ Autonoma Estado Morelos, CEAMISH, Cuernavaca, Morelos, Mexico. Univ Colorado, Dept Environm Populat & Organism Biol, Boulder, CO 80309 USA. RP Jeffery, WR, Univ Maryland, Dept Biol, College Pk, MD 20742 USA. 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Dev. PD SEP-OCT PY 2003 VL 5 IS 5 BP 435 EP 446 PG 12 SC Evolutionary Biology; Developmental Biology; Genetics & Heredity GA 724KR UT ISI:000185487200001 ER PT J AU Holguin, F Tellez-Rojo, MM Hernandez, M Cortez, M Chow, JC Watsow, JG Mannino, D Romieu, I TI Air pollution and heart rate variability among the elderly in Mexico City SO EPIDEMIOLOGY LA English DT Article DE particulate air pollution; ozone; heart rate variability; Mexico; elderly ID ENVIRONMENTAL EXPOSURE; PARTICULATE; MORTALITY; RISK; ASSOCIATION; RECORDINGS; PARTICLES; HEALTH; COHORT AB Background: Suspended particles and ozone have been associated with varying degrees of cardiac autonomic dysfunction. Methods: In Mexico City, residents from a nursing home underwent heart rate variability analysis every other day for 3 months. Indoor and outdoor PM2.5 (particulate matter less than 2.5 mm in diameter) were measured daily at the nursing home. Levels of ozone and other atmospheric pollutants were obtained from a nearby automated monitoring station. Results: Of the initial 42 screened participants, 34 (81%) were followed during the study period. The 24-hour average levels of indoor PM2.5 ranged from 15 to 67 mug/m(3), and outdoor PM2.5 ranged from 9 to 87 mug/m(3). Daily 1-hour maximum ozone levels ranged from 47 to 228 ppb. After adjusting for age and heart rate, we observed a strong decrease in the high frequency component of heart rate variability and the average 24-hour concentrations of PM2.5. Participants with hypertension had considerably larger reductions in their HF-HRV (high frequency-heart rate variability) component in relation to both ozone and PM2.5 exposure. Conclusions: Our results suggest that ambient levels of PM2.5 and ozone can reduce the high-frequency component of heart rate variability in elderly subjects living in Mexico City and that subjects with underlying hypertension are particularly susceptible to this effect. C1 Emory Univ, Sch Med, Atlanta, GA USA. Inst Nacl Salud Publ, Cuernavaca, Morelos, Mexico. Hosp ABC, Mexico City, DF, Mexico. Univ Nevada, Desert Res Inst, Reno, NV 89506 USA. Ctr Dis Control & Prevent, Atlanta, GA USA. RP Holguin, F, Emory Univ, Sch Med, Grady Mem Hosp, Suite 2C007,80 Jesse Hill Jr Dr, Atlanta, GA 30335 USA. CR BORJAABURTO VH, 1998, ENVIRON HEALTH PERSP, V106, P849 BURNETT RT, 1999, ARCH ENVIRON HEALTH, V54, P130 CAMM AJ, 1996, CIRCULATION, V93, P1043 CARABIAS LJ, 2000, ALMANAQUE DATOS TEND DEKKER JM, 1997, AM J EPIDEMIOL, V145, P899 DIGGLE PJ, 2001, ANAL LONGITUDINAL DA GODLESKI JJ, 2000, HLTH EFFECTS I RES R GOLD DR, 2000, CIRCULATION, V101, P1267 KENNEDY HL, 1995, HEART RATE VARIABILI, P127 KOENIG W, 2000, BRIT J HAEMATOL, V109, P453 LIAO DP, 1999, ENVIRON HEALTH PERSP, V107, P521 MAGARI SR, 2001, CIRCULATION, V104, P986 MAGARI SR, 2002, EPIDEMIOLOGY, V13, P305 NEMMAR A, 2002, CIRCULATION, V105, P411 POPE CA, 1999, AM HEART J 1, V138, P890 POPE CA, 1999, AM J RESP CRIT CARE, V159, P365 POPE CA, 2000, ENVIRON HEALTH PE S4, V108, P713 SCHWARTZ J, 1994, ENVIRON RES, V64, P36 SCHWARTZ J, 2001, ENVIRON HEALTH PE S3, V109, P405 SINGH JP, 1998, HYPERTENSION, V32, P293 SINNREICH R, 1998, HEART, V80, P156 STEIN PK, 1994, AM HEART J, V127, P1376 TOLBERT PE, 2000, J EXPO ANAL ENV EPID, V10, P446 TSUJI H, 1994, CIRCULATION, V90, P878 TSUJI H, 1996, CIRCULATION, V94, P2850 WATKINSON WP, 2001, ENVIRON HEALTH PE S4, V109, P539 WORDLEY J, 1997, OCCUP ENVIRON MED, V54, P108 NR 27 TC 40 PU LIPPINCOTT WILLIAMS & WILKINS PI PHILADELPHIA PA 530 WALNUT ST, PHILADELPHIA, PA 19106-3621 USA SN 1044-3983 J9 EPIDEMIOLOGY JI Epidemiology PD SEP PY 2003 VL 14 IS 5 BP 521 EP 527 PG 7 SC Public, Environmental & Occupational Health GA 718EV UT ISI:000185132900005 ER PT J AU Nieva, D Barragan, RM TI HCO-TERNARY: A FORTRAN code for calculating P-V-T-X properties and liquid vapor equilibria of fluids in the system H2O-CO2-CH4 SO COMPUTERS & GEOSCIENCES LA English DT Article DE equation of state; volumetric properties; vapor-liquid equilibria; H2O-CO2-CH4 fluids ID CH4-CO2-H2O SYSTEM; CO2-H2O SYSTEM; EQUATION; MIXTURES; STATE; 1000-DEGREES-C; TEMPERATURES; PRESSURES; DENSITIES; BAR AB The equation of state (EOS) for the system H2O-CO2-CH4 was programmed in a FORTRAN code which allows for its utilization in several modes. In one mode, specifically designed for mathematical modeling of two-phase, two-component flow, the code accepts as independent variables (1) pressure and (2) the composition of the gas phase. Other modes allow for the calculation of phase equilibria and/or the molar volumes of H2O and binary mixtures, with pressure and temperature as the input variables (just pressure in the case of H2O). Another mode is used to calculate phase equilibria for ternary mixtures, with pressure, temperature and the mole fraction of water in the gas phase as input variables. The algorithms for automatic convergence utilized in each mode are described. The code was tested extensively against experimental data from the literature. Some of these data were applied in the development of the EOS, and others were published subsequently. Analyses of the performance of the code and EOS for the modes described above, in the range 50-1000degreesC, 0-1000 bar, are presented. P-T-X regions of best applicability of the code and EOS are also identified. (C) 2003 Elsevier Science Ltd. All rights reserved. C1 Inst Invest Elect, Temixco 62490, Morelos, Mexico. RP Nieva, D, Inst Invest Elect, Av Reforma 113,Col Palmira, Temixco 62490, Morelos, Mexico. CR ARAI Y, 1971, J CHEM ENG JAPAN, V4, P113 BAKKER RJ, 2000, GEOCHIM COSMOCHIM AC, V64, P1753 BLENCOE JG, 1996, INT J THERMOPHYS, V17, P179 BLENCOE JG, 2001, AM MINERAL, V86, P1100 BURNHAM CW, 1969, AM J SCI A, V267, P70 CALLEN HB, 1960, THERMODYNAMICS CULBERSON OL, 1952, METALLURGICAL PROBLE, V192, P223 DONNELLY HG, 1954, IND ENG CHEM, V46, P511 DOUSLIN DR, 1964, J CHEM ENG DATA, V9, P358 DUAN ZH, 1992, GEOCHIM COSMOCHIM AC, V56, P2605 DUAN ZH, 1992, GEOCHIM COSMOCHIM AC, V56, P2619 DUAN ZH, 1996, GEOCHIM COSMOCHIM AC, V60, P1209 FENGHOUR A, 1996, J CHEM THERMODYN, V28, P433 JOFFRION LL, 1989, J CHEM ENG DATA, V34, P215 KEENAN JH, 1978, STEAM TABLES THERMOD KENNEDY GC, 1954, AM J SCI, V252, P225 MALININ SD, 1959, GEOCHEM INT, V3, P292 OLDS RH, 1942, IND ENG CHEM, V34, P1223 OLDS RH, 1943, IND ENG CHEM, V35, P922 OSULLIVAN MJ, 1981, WATER RESOUR RES, V17, P390 PRICE LC, 1979, AAPG BULL, V63, P1527 RAMBOZ C, 1985, GEOCHIM COSMOCHIM AC, V49, P205 REAMER HH, 1944, IND ENG CHEM, V36, P88 ROEDDER E, 1984, REV MINERAL, V12, P644 SEITZ JC, 1997, P 5 INT S HYDR REACT, P109 SEITZ JC, 1999, GEOCHIM COSMOCHIM AC, V63, P1559 SULTANOV RG, 1971, CAZOVAIA PROMYSHLENN, V16, P6 TAKENOUCHI S, 1964, AM J SCI, V262, P1055 TODHEIDE K, 1963, Z PHYS CHEM, V37, P387 VUKALOVICH MP, 1963, TEPLOENERGETICA, V10, P85 ZAKIROV IV, 1984, GEOCHEM INT, V21, P13 NR 31 TC 2 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0098-3004 J9 COMPUT GEOSCI JI Comput. Geosci. PD MAY PY 2003 VL 29 IS 4 BP 469 EP 485 PG 17 SC Computer Science, Interdisciplinary Applications; Geosciences, Multidisciplinary GA 684DL UT ISI:000183190100006 ER PT J AU Padilla-Martinez, II Chaparro-Huerta, M Martinez-Martinez, FJ Hopfl, H Garcia-Baez, EV TI Diethyl N,N''-m-phenylenedioxamate SO ACTA CRYSTALLOGRAPHICA SECTION E-STRUCTURE REPORTS ONLINE LA English DT Article ID HYDROGEN-BOND AB The title compound, C14H16N2O6, crystallizes in the monoclinic space group, C2/c. C-2 symmetry is imposed on the molecule. The ethyl oxamate groups are twisted out of the aromatic ring plane by 34.53 (6)degrees and both carbonyl groups are antiperiplanar. The intramolecular hydrogen-bonding pattern is depicted by a soft C-H...O/O' three-centered hydrogen bond, and N-H...O and C-H...O hydrogen-bonding interactions which form an S(5) S(5) S(6) S(6) 'S(5) 'S(5)' motif. The molecules are linked into C(3) and C(4) chain motifs, forming supramolecular layers in the ac plane. C1 Inst Politecn Nacl, Unidad Profes Interdisciplinaria Biotecnol, Barrio La Laguna Ticoman 07340, DF, Mexico. Univ Autonoma Morelos, Ctr Invest Quim, Cuernavaca, Morelos, Mexico. RP Garcia-Baez, EV, Inst Politecn Nacl, Unidad Profes Interdisciplinaria Biotecnol, Ave Acueducto S-N,Barrio Laguna, Ticoman 07340, DF, Mexico. CR *BRUK AXS INC, 2000, SMART SAINT SHELXTL ALLEN FH, 1987, J CHEM SOC P2, V2, P1 BERNSTEIN J, 1995, ANGEW CHEM INT EDIT, V34, P1555 BONDI A, 1964, J PHYS CHEM-US, V68, P441 DESIRAJU GR, 1996, ACCOUNTS CHEM RES, V29, P441 DEWAR MJS, 1960, TETRAHEDRON, V11, P96 FARRUGIA LJ, 1999, J APPL CRYSTALLOGR, V32, P837 MARTIN S, 2002, ACTA CRYSTALLOGR E 8, V58, O913 MARTINEZMARTINEZ FJ, 1998, J CHEM SOC PERK FEB, P401 PADILLAMARTINEZ II, 2001, J CHEM SOC PERK SEP, P1817 SHELDRICK GM, 1997, SHELXS97 SHELXL97 STEINER T, 2002, ANGEW CHEM INT EDIT, V41, P48 VARGAS R, 2000, J AM CHEM SOC, V122, P4750 NR 13 TC 6 PU BLACKWELL MUNKSGAARD PI COPENHAGEN PA 35 NORRE SOGADE, PO BOX 2148, DK-1016 COPENHAGEN, DENMARK SN 1600-5368 J9 ACTA CRYSTALLOGR E-STRUCT REP JI Acta Crystallogr. Sect. E.-Struct Rep. Online PD JUN PY 2003 VL 59 PN Part 6 BP O825 EP O827 PG 3 SC Crystallography GA 683TR UT ISI:000183166300070 ER PT J AU Castillo, E Pezzotti, F Navarro, A Lopez-Munguia, A TI Lipase-catalyzed synthesis of xylitol monoesters: solvent engineering approach SO JOURNAL OF BIOTECHNOLOGY LA English DT Article DE solvent engineering; solvent mixtures hydrophobicity; lipase; organic solvents; polyol esters; selective synthesis; xylitol ID FATTY-ACID ESTERS; ENZYMATIC-SYNTHESIS; CANDIDA-ANTARCTICA; REDUCED PRESSURE; SUGAR ALCOHOLS; ORGANIC MEDIA; BIOSURFACTANTS; OPTIMIZATION; DISACCHARIDE; ACYLATION AB A solvent engineering strategy was applied to the lipase-catalyzed synthesis of xylitol-oleic acid monoesters. The different esterification degrees for this polyhydroxylated molecule were examined in different organic solvent mixtures. In this context, conditions for high selectivity towards monooleoyl xylitol synthesis were enhanced from 6 mol% in pure n-hexane to 73 mol% in 2-methyl-2-propanol/dimethylsulfoxide (DMSO) 80:20 (v/v). On the contrary, the highest production of di- and trioleoyl xylitol, corresponding to 94 mol%, was achieved in n-hexane. Changes in polarity of the reaction medium and in the molecular interactions between solvents and reactants were correlated with the activity coefficients of products. Based on experimental results and calculated thermodynamic activities, the effect of different binary mixtures of solvents on the selective production of xylitol esters is reported. From this analysis, it is concluded that in the more polar conditions (100% dimethylsulfoxide (DMSO)), the synthesis of xylitol monoesters is favored. However, these conditions are unfavorable in terms of enzyme stability. As an alternative, binary mixtures of solvents were proposed. Each mixture of solvents was characterized in terms of the quantitative polarity parameter ET(30) and related with the activity coefficients of xylitol esters. To our knowledge, the characterization of solvent mixtures in terms of this polarity parameter and its relationship with the selectivity of the process has not been previously reported. (C) 2003 Elsevier Science B.V. All rights reserved. C1 UNAM, Inst Biotecnol, Dept Bioingn, Cuernavaca 62271, Morelos, Mexico. Univ Nacl Autonoma Mexico, Fac Quim, Dept Alimentos & Biotecnol, Mexico City 04510, DF, Mexico. RP Castillo, E, UNAM, Inst Biotecnol, Dept Bioingn, Apartado Postal 510-3, Cuernavaca 62271, Morelos, Mexico. CR ARCOS JA, 1998, BIOTECHNOL BIOENG, V60, P53 BALDWIN PJ, 1998, 005830872, US BELLOT JC, 2001, ENZYME MICROB TECH, V28, P362 CASTILLO E, 1994, BIOTECHNOL LETT, V16, P169 CASTILLO E, 1998, J AM OIL CHEM SOC, V75, P309 CHOPINEAU J, 1988, BIOTECHNOL BIOENG, V31, P208 CHUNG HY, 1996, J AM OIL CHEM SOC, V73, P637 COULON D, 1999, PROCESS BIOCHEM, V34, P913 DEGN P, 1999, BIOTECHNOL LETT, V21, P275 DEGN P, 2001, BIOTECHNOL BIOENG, V74, P483 DUCRET A, 1995, BIOTECHNOL BIOENG, V48, P214 DUCRET A, 1996, J AM OIL CHEM SOC, V73, P109 FREDENSLUND A, 1975, AICHE J, V21, P1086 GEBHARDT S, 2002, HELV CHIM ACTA, V85, P1943 GMEHLING J, 1993, IND ENG CHEM RES, V32, P178 HALLING PJ, 1994, ENZYME MICROB TECH, V16, P178 IKEDA I, 1993, BIOTECHNOL BIOENG, V42, P788 JANSSEN AEM, 1993, BIOTECHNOL BIOENG, V41, P95 KHALED N, 1991, BIOTECHNOL LETT, V13, P167 OTERO C, 2001, J MOL CATAL B-ENZYM, V11, P883 PLOU FJ, 2002, J BIOTECHNOL, V96, P55 REICHARDT C, 1979, ANGEW CHEM INT EDIT, V18, P98 RENDON X, 2001, J AM OIL CHEM SOC, V78, P1061 SARNEY DB, 1994, J AM OIL CHEM SOC, V71, P711 SARNEY DB, 1997, BIOTECHNOL BIOENG, V54, P351 WELTON T, 1999, CHEM REV, V99, P2071 NR 26 TC 20 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-1656 J9 J BIOTECHNOL JI J. Biotechnol. PD MAY 8 PY 2003 VL 102 IS 3 BP 251 EP 259 PG 9 SC Biotechnology & Applied Microbiology GA 678WA UT ISI:000182888600005 ER PT J AU Kubiak, J Garcia-Gutierrez, A Urquiza, G TI The diagnosis of turbine component degradation - case histories SO APPLIED THERMAL ENGINEERING LA English DT Article DE component degradation; flow analysis; thermodynamic analysis; power losses; efficiency; steam and gas turbines AB Four case histories of steam and gas turbine components degradation identified during operation and verified during overhaul are presented. The diagnosis was carried out before the overhauls to indicate major problems to the personal of the plants. The estimation of degrees of degradation of the steam turbine components was carried out applying simplified flow equation [1] considering three key pressures. In the case of the gas turbine the output capacity and pressures, temperature and air and gas flow were analyzed. The results obtained during on-line analysis were confirmed by measurements of the dimensions of degraded components during an overhaul. Also, the results obtained from a sophisticated computer program proved the usefulness of the applied methods. (C) 2002 Elsevier Science Ltd. All rights reserved. C1 Univ Autonoma Estado Morelos, Ctr Invest Ingn & Ciencias Aplicadas, Cuernavaca 62210, Morelos, Mexico. Inst Invest Elect, Garencia Geotermia, Temixco 62490, Mexico. Inst Invest Elect, Garencia Turbomaquinaria, Temixco 62490, Mexico. RP Kubiak, J, Univ Autonoma Estado Morelos, Ctr Invest Ingn & Ciencias Aplicadas, Av Univ 1001,Col Chamilpa, Cuernavaca 62210, Morelos, Mexico. CR BLAZKO E, 1994, TURBINA COMPUTER PRO COTTON KC, 1993, EVALUATING IMPROVING KUBIAK J, UNPUB APPL THERMAL E KUBIAK J, 1996, P ASME IJPGC HOUST O, V2, P463 KUBIAK J, 2002, GEOTHERMICS, V31, P542 LUNIEWICZ B, 1990, IIE342257040P TURBOF URQUIZA G, 1998, 7 INT S TRANSP PHEN, P1693 NR 7 TC 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 1359-4311 J9 APPL THERM ENG JI Appl. Therm. Eng. PD DEC PY 2002 VL 22 IS 17 BP 1955 EP 1963 PG 9 SC Thermodynamics; Energy & Fuels; Engineering, Mechanical; Mechanics GA 619ZQ UT ISI:000179508300007 ER PT J AU de Haro, ML del Rio, JA Vazquez, F TI Light-scattering spectrum of a viscoelastic fluid subjected to an external temperature gradient SO REVISTA MEXICANA DE FISICA LA English DT Article DE fluctuating hydrodynamics; nonequilibrium steady states; Maxwell fluid; dynamic structure factor ID EQUILIBRIUM STEADY-STATE; RAYLEIGH-BRILLOUIN SCATTERING; HYDRODYNAMIC FLUCTUATIONS; THERMAL-EQUILIBRIUM; INTERNAL DEGREES; LIQUID; THERMODYNAMICS; FREEDOM AB The light-scattering spectrum for a Maxwell fluid in a steady state due to the presence of an external temperature gradient is computed. In such a fluid beat conduction is assumed to be governed by the classical Fourier law. The calculation is carried out through the use of fluctuating hydrodynamics. The effect of the non-Newtonian character of the fluid in the resulting spectrum is discussed. C1 Univ Nacl Autonoma Mexico, Ctr Invest & Energia, Temixco 62580, Morelos, Mexico. Univ Autonoma Estado Morelos, Fac Ciencias, Cuernavaca 62210, Morelos, Mexico. RP de Haro, ML, Univ Nacl Autonoma Mexico, Ctr Invest & Energia, Temixco 62580, Morelos, Mexico. 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Mex. Fis. PD SEP PY 2002 VL 48 SU Suppl. 1 BP 230 EP 237 PG 8 SC Physics, Multidisciplinary GA 601BC UT ISI:000178425400025 ER PT J AU Hernandez-Cobos, J Vega, LF TI The influence of the density in the hydrophobic hydration of methane in supercritical water. SO JOURNAL OF MOLECULAR LIQUIDS LA English DT Article ID VAPOR COEXISTENCE CURVE; MOLECULAR SIMULATION; COMPUTER-SIMULATION; LIQUID; 25-DEGREES-C; TEMPERATURE; EQUILIBRIA; MODEL AB We present a molecular simulation study for the hydrophobic hydration of methane as a function of density, at supercritical temperature. Thermodynamics and structural properties of methane in water for a wide range of densities of water, at a given temperature are presented here. In order to check the influence of the molecular model on these properties, two different intermolecular potentials are used, a semiempirical, well-known model for water, the TIP4P model, and an ab-initio based, polarizable model, the MCHO potential. Both models predict the same qualitative behavior at all conditions studied. The main results obtained from this work are that while the free energy is a strong function of the water density, the water-water structure remains almost unaltered, from medium to high density of water. The strong dependency of the free energy on density is then attributed to changes in entropy, reflected in the water-methane correlation functions. (C) 2002 Elsevier Science B.V. All rights reserved. C1 Univ Nacl Autonoma Mexico, Ctr Ciencias Fis, Cuernavaca 62251, Morelos, Mexico. Univ Rovira & Virgili, Dept Engn Quim, Escola Tecn Super Engn Quim, Tarragona 43007, Spain. RP Hernandez-Cobos, J, Univ Nacl Autonoma Mexico, Ctr Ciencias Fis, Apdo Postal 48-3, Cuernavaca 62251, Morelos, Mexico. 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Mol. Liq. PD NOV PY 2002 VL 101 IS 1-3 BP 113 EP 125 PG 13 SC Chemistry, Physical; Physics, Atomic, Molecular & Chemical GA 594TN UT ISI:000178067200011 ER PT J AU Sanchez, J Wallerstrom, G Fredriksson, M Angstrom, J Holmgren, J TI Detoxification of cholera toxin without removal of its immunoadjuvanticity by the addition of (STa-related) peptides to the catalytic subunit - A potential new strategy to generate immunostimulants for vaccination SO JOURNAL OF BIOLOGICAL CHEMISTRY LA English DT Article ID HEAT-LABILE ENTEROTOXIN; ADP-RIBOSYLTRANSFERASE ACTIVITY; TOXIGENIC ESCHERICHIA-COLI; CRYSTAL-STRUCTURE; VIBRIO-CHOLERAE; A-SUBUNIT; B-SUBUNIT; MONOCLONAL-ANTIBODIES; ADENYLATE-CYCLASE; MUCOSAL ADJUVANT AB Peptides related to the heat-stable enterotoxin STa were fused to the N terminus of the A-subunit of cholera toxin (CTA) to explore whether peptide additions could help generate detoxified cholera toxin (CT) derivatives. Proteins carrying APRPGP (6-CTA), ASRCAELCC-NPACPAP (16-CTA), or ANSSNYCCELCCNPACTGCYPGP (23-CTA) were genetically constructed. Using a two-plasmid system these derivatives were co-expressed in Vibrio cholerae with cholera toxin B-subunit (CTB) to allow formation and secretion of holotoxin-like molecules (engineered CT, eCTs). Purified eCTs maintained all normal CT properties yet they were more than 10-fold (eCT-6), 100-fold (eCT-16), or 1000-fold (eCT-23) less enterotoxic than wild-type CT. The inverse correlation between enterotoxicity and peptide length indicated sterical interference with the ADP-ribosylating active site in CTA. This interpretation agreed with greater than 1000-fold reductions in cAMP induction, with reductions, albeit not proportional, in in vitro agmatine ADP-ribosylation, and was supported by molecular simulations. Intranasal immunization of mice demonstrated that eCTs retained their inherent immunogenicity and ability to potentiate immune responses to a co-administered heterologous protein antigen, although in variable degrees. Therefore, the addition of STa-related peptides to CTA reduced the toxicity of CT while partly preserving its natural immunoadjuvanticity. These results suggest peptide extensions to CTA are a useful alternative to site-directed mutagenesis to detoxify CT. The simplicity of the procedure, combined with efficient expression and assembly of derivatives, suggests this approach could allow for large scale production of de. toxified, yet immunologically active CT molecules. C1 Univ Autonoma Estado Morelos, Fac Med, Cuernavaca 62210, Morelos, Mexico. Gothenburg Univ, Dept Med Microbiol & Immunol, SE-41346 Gothenburg, Sweden. Gothenburg Univ, Vaccine Res Inst, SE-41346 Gothenburg, Sweden. Gothenburg Univ, Inst Med Biochem, SE-40530 Gothenburg, Sweden. RP Sanchez, J, Univ Autonoma Estado Morelos, Fac Med, Av Univ 101,Col Chamilpa, Cuernavaca 62210, Morelos, Mexico. 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PD SEP 6 PY 2002 VL 277 IS 36 BP 33369 EP 33377 PG 9 SC Biochemistry & Molecular Biology GA 591BC UT ISI:000177859000126 ER PT J AU Sanchez, G Latombe, JC TI On delaying collision checking in PRM planning: Application to multi-robot coordination SO INTERNATIONAL JOURNAL OF ROBOTICS RESEARCH LA English DT Article DE motion planning; probabilistic roadmaps; lazy collision checking; multi-robot coordination ID PROBABILISTIC ROADMAPS; CONFIGURATION-SPACES; MOTION; PATH; OBJECTS; OBSTACLES AB This paper describes the foundations and algorithms of a new probabilistic roadmap (PRM) planner that is: single-query-instead of pre-computing a roadmap covering the entire free space, it uses the two input query configurations to explore as little space as possible; bi-directional-it explores the robot's free space by building a roadmap made of two trees rooted at the query configurations,and lazy in checking collisions-it delays collision tests along the edges of the roadmap until they are absolutely needed. Several observations motivated this strategy: (1) PRM planners spend a large fraction of their time testing connections for collision; (2) most connections in a roadmap are not on the final path; (3) the collision test for a connection is most expensive when there is no collision; and (4) any short connection between two collision-free configurations has high prior probability of being collision-free. The strengths of single-query and bi-directional sampling techniques and those of delayed collision checking reinforce each other. Experimental results show that this combination reduces planning time by a large factor, making it possible to efficiently handle difficult planning problems, such as problems involving multiple robots in geometrically complex environments. This paper specifically describes the application of the planner to multi-robot planning and compares results obtained when the planner uses a centralized planning approach (PRM planning is then performed in the joint configuration space of the robots) and when it uses a decoupled approach (the PRM planner is invoked several times, first to compute a path of each robot independent of the others, and then to coordinate those paths). On a simulated six-robot welding station combining 36 degrees of freedom, centralized planning has proven to be a much more effective approach than decoupled planning. C1 ITESM, Cuernavaca, Morelos, Mexico. Stanford Univ, Dept Comp Sci, Stanford, CA 94305 USA. RP Sanchez, G, ITESM, Campus Cuernavaca, Cuernavaca, Morelos, Mexico. 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J. Robot. Res. PD JAN PY 2002 VL 21 IS 1 BP 5 EP 26 PG 22 SC Robotics GA 577FT UT ISI:000177051400001 ER PT J AU Hess, B Saint-Martin, H Berendsen, HJC TI Flexible constraints: An adiabatic treatment of quantum degrees of freedom, with application to the flexible and polarizable mobile charge densities in harmonic oscillators model for water SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID MOLECULAR-DYNAMICS SIMULATION; PATH CENTROID DENSITY; LIQUID WATER; NEUTRON-DIFFRACTION; POTASSIUM CHANNEL; FORMULATION; GEOMETRY; SYSTEMS; ENERGY; EQUILIBRIUM AB In classical molecular simulations chemical bonds and bond angles have been modeled either as rigid constraints, or as nearly harmonic oscillators. However, neither model is a good description of a chemical bond, which is a quantum oscillator that in most cases occupies the ground state only. A quantum oscillator in the ground state can be represented more faithfully by a flexible constraint. This means that the constraint length adapts itself, in time, to the environment, such that the rotational and potential forces on the constraint cancel out. An accurate algorithm for flexible constraints is presented in this work and applied to study liquid water with the flexible and the polarizable "mobile charge densities in harmonic oscillators" model. The iterations for the flexible constraints are done simultaneously with those for the electronic polarization, resulting in negligible additional computational costs. A comparison with fully flexible and rigidly constrained simulations shows little effect on structure and energetics of the liquid, while the dynamics is somewhat faster with flexible constraints. (C) 2002 American Institute of Physics. C1 Univ Groningen, Dept Biophys Chem, NL-9747 AG Groningen, Netherlands. Univ Nacl Autonoma Mexico, Ctr Ciencias Fis, Cuernavaca 62251, Morelos, Mexico. RP Hess, B, Univ Groningen, Dept Biophys Chem, Nijenborgh 4, NL-9747 AG Groningen, Netherlands. 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Chem. Phys. PD JUN 8 PY 2002 VL 116 IS 22 BP 9602 EP 9610 PG 9 SC Physics, Atomic, Molecular & Chemical GA 554PL UT ISI:000175744600007 ER PT J AU Villegas-Garcia, JC Santillan-Alarcon, S TI Sylvatic focus of American Trypanosomiasis in the State of Morelos, Mexico SO REVISTA DE BIOLOGIA TROPICAL LA English DT Article DE Trypanosoma cruzi; wild mammals; Triatoma pallidipennis; Mexico ID CRUZI AB Wild vectors and reservoir hosts of Trypanosoma cruzi were surveyed from February 1993 to June 1994 in Ticuman (18 degrees 46'N, 99 degrees 07'W), Mexico (Deciduous Tropical Forest). Direct faeces examination showed that 87% of Triatoma pallidipennis hosted the parasite; T cruzi forms were present in cultures inoculated with faeces of fifty 67% triatomine bugs and thirty CD-1 strain mice (10 d old) inoculated (peritoneum) with faeces of positive insects T cruzi amastigotes were found in heart 67%, kidneys 47%, liver 80%, lungs 50%, oesophagus 60%, skin 23%, spleen 73% and stomach 60%. T cruzi was isolated by direct blood examination from seven 21% chiropterans and five 38% rodents and T cruz! forms were present in cultures inoculated with blood of twenty-three 68% chiropterans and seven 54% rodents and T cruzi amastigotes were seen in the kidneys of one 3% chiropterans and four 31% rodents and only in one Pteronotus parnellii mexicanus, organisms were seen in skin 2%. There was no association between organs and T cruzi infection (p > 0.05). C1 Univ Autonoma Estado Morelos, Lab Mastozool, Dept Biol Anim, Ctr Invest Biol, Cuernavaca 62210, Morelos, Mexico. RP Villegas-Garcia, JC, Univ Autonoma Estado Morelos, Lab Mastozool, Dept Biol Anim, Ctr Invest Biol, Ave Univ 1 001, Cuernavaca 62210, Morelos, Mexico. CR ARRIOLA GMT, 1989, 1 ENC EST ENT MED VE, P109 BAUTISTA LNL, 1992, 3 REUN NAC ENF CHAG BOTERO D, 1994, PARASITOSIS HUMANA C, P191 BUSH AO, 1997, J PARASITOL, V83, P575 CARCAVALLO RU, 1985, FACTORES BIOL ECOLOG, V1, P49 DALESSANDRO A, 1984, AM J TROP MED HYG, V33, P1084 GARCIA E, 1988, MODIFICACIONES SISTE HERLINDOJAIMES F, 1998, THESIS U AUTONOMA ES LENT H, 1979, B AM MUS NAT HIST, V163, P123 MAGDALENO PN, 1990, 2 REUN NAC ENF CHAG PARRA TRL, 1992, 3 REUN NAC ENF CHAG PEREIRABARRETTO M, 1985, FACTORES BIOL ECOLOG, P275 RAMIREZPULIDO J, 1989, MANEJO MANTENIMIENTO ROSARIO CR, 1989, THESIS U AUTONOMA ES WILSON DE, 1993, MAMMAL SPECIES WORLD WISNIVESKYCOLLI C, 1992, T ROY SOC TROP MED H, V86, P38 NR 16 TC 3 PU REVISTA DE BIOLOGIA TROPICAL PI SAN JOSE PA UNIVERSIDAD DE COSTA RICA CIUDAD UNIVERSITARIA, SAN JOSE, COSTA RICA SN 0034-7744 J9 REV BIOL TROP JI Rev. Biol. Trop. PD JUN PY 2001 VL 49 IS 2 BP 685 EP 688 PG 4 SC Biology GA 506HN UT ISI:000172964200029 ER PT J AU Jauregui, R Recamier, J Quinto-Su, PA TI On decoherence and nonlinear effects in the generation of quantum states of motion in Paul traps SO JOURNAL OF OPTICS B-QUANTUM AND SEMICLASSICAL OPTICS LA English DT Article DE decoherence; nonclassical states; nonlinear effects ID COHERENT STATES; IONS; OPTICS; ATOM; ENTANGLEMENT; CRYPTOGRAPHY; OSCILLATIONS AB We study some possible sources of decoherence in the generation of nonclassical states of motion of ions in Paul traps by means of numerical simulations based on reported experiments. In particular we study the consequences of the spontaneous decay of the internal energy state \0 > (i) which couples the two hyperfine internal states \1 > (i) and \2 > (i) in the two-photon Raman transitions used to manipulate the ion motional state. We also consider some possible experimental limitations to generate coherent states due to nonlinear effects in the coupling of the centre-of-mass coordinates with the laser field. A similar analysis is performed for carrier pulses taking into account nonlinearities and micromotion. The quantum evolution of the ion internal and centre-of-mass degrees of freedom are studied using amplitude equations derived from Schrodinger's equation. The limitations of such an approach are also discussed. C1 Univ Nacl Autonoma Mexico, Inst Fis, Mexico City 01000, DF, Mexico. UNAM, Ctr Ciencias Fis, Cuernavaca 62251, Morelos, Mexico. RP Jauregui, R, Univ Nacl Autonoma Mexico, Inst Fis, Apdo Postal 20364, Mexico City 01000, DF, Mexico. CR BARDROFF PJ, 1996, PHYS REV LETT, V77, P2198 BARENCO A, 1995, J MOD OPTIC, V42, P1253 BENNETT CH, 1992, SCI AM, V267, P50 BENNETT CH, 1995, PHYS TODAY, V48, P24 BERKELAND DJ, 1998, J APPL PHYS, V83, P5025 CARRUTHERS P, 1965, AM J PHYS, V33, P537 CASTANOS O, 1997, PHYS REV A, V55, P1208 CIRAC JI, 1995, PHYS REV LETT, V74, P4091 COHENTANNOUDJI C, 1994, WORLD SCI SERIES ATO, V1 DALIBARD J, 1992, PHYS REV LETT, V68, P580 DEHLMELT H, 1985, B AM PHYS SOC, V30, P111 DEMATOS RL, 1996, PHYS REV A, V54, P4560 DIFIDIO C, 2000, PHYS REV A, V62 DODONOV VV, 1974, PHYSICA, V72, P597 EKERT AK, 1991, PHYS REV LETT, V67, P661 GILMORE R, 1974, LIE GROUPS LIE ALGEB GREENBERGER DM, 1993, PHYS TODAY, V46, P22 GROVER LK, 1997, PHYS REV LETT, V79, P325 HEINZEN DJ, 1990, PHYS REV A, V42, P2977 JAUREGUI R, UNPUB JAYNES ET, 1963, P IEEE, V51, P89 JEFFERTS SR, 1995, PHYS REV A, V51, P3112 KAHILL KE, 1969, PHYS REV, V177, P1857 KING BE, 1998, PHYS REV LETT, V81, P1525 LANDAU LD, 1978, MECANICA CUANTICA TE LINDBERG M, 1986, J OPT SOC AM B, V3, P1008 MEEKHOF DM, 1996, PHYS REV LETT, V76, P1796 MOLMER K, 1993, J OPT SOC AM B, V10, P524 MONROE C, 1995, PHYS REV LETT, V75, P4011 MONROE C, 1996, SCIENCE, V272, P1131 PLENIO MB, 1998, REV MOD PHYS, V70, P101 ROOS CF, 2000, PHYS REV LETT 1, V85, P5547 SCHNEIDER S, 1998, PHYS REV A, V57, P3748 SHOR PW, 1997, SIAM J COMPUT, V26, P1484 TOSCHEK PE, 1989, J OPT SOC AM B, V6, P2220 TURCHETTE QA, 1998, PHYS REV LETT, V81, P3631 WINELAND DJ, 1979, PHYS REV A, V20, P1521 WINELAND DJ, 1994, PHYS REV A, V50, P67 WINELAND DJ, 1998, J RES NATL INST STAN, V103, P259 NR 39 TC 2 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 1464-4266 J9 J OPT B-QUANTUM SEMICL OPT JI J. Opt. B-Quantum Semicl. Opt. PD AUG PY 2001 VL 3 IS 4 BP 194 EP 205 PG 12 SC Optics; Physics, Applied GA 481WH UT ISI:000171543100003 ER PT J AU Olivares-Robles, MA Ulloa, SE TI Interaction potential between dynamic dipoles: Polarized excitons in strong magnetic fields SO PHYSICAL REVIEW B LA English DT Article ID COUPLED QUANTUM-WELLS; DIELECTRIC FUNCTION; ELECTRONS; SYSTEMS; CONDENSATION; TRANSITIONS; BOSONS; HOLES; STATE AB The interaction potential of a two-dimensional system of excitons with spatially separated electron-hole layers is considered in the strong magnetic field limit. The excitons are assumed to have free dynamics in the x-y plane, while being constrained or "polarized" in the z direction. The model simulates semiconductor double layer systems under strong magnetic field normal to the layers. The residual interaction between excitons exhibits interesting features, arising from the coupling of the center-of-mass and internal degrees of freedom of the exciton in the magnetic field. This coupling induces a dynamical dipole moment proportional to the center-of-mass magnetic moment of the exciton. We show the explicit dependence of the interexciton potential matrix elements, and discuss the underlying physics. The unusual features of the interaction potential would be reflected in the collective response and nonequilibrium properties of such system. C1 Ohio Univ, Dept Phys & Astron, Athens, OH 45701 USA. Ohio Univ, Condensed Matter & Surface Sci Program, Athens, OH 45701 USA. RP Olivares-Robles, MA, Univ Autonoma Estado Morelos, Fac Ciencias, Dept Fis, Av Univ 1001,Col Chamilpa, Cuernavaca 62210, Morelos, Mexico. CR BUTOV LV, 1994, PHYS REV LETT, V73, P304 DZYUBENKO AB, 1997, JETP LETT+, V66, P617 EHRENREICH H, 1959, PHYS REV, V115, P786 FUKUZAWA T, 1990, PHYS REV LETT, V64, P3066 GORAL K, 2000, PHYS REV A, V61 GORKOV LP, 1968, SOV PHYS JETP, V26, P449 KACHINTSEV DM, 1994, PHYS REV B, V50, P8715 KASH JA, 1991, PHYS REV LETT, V66, P2247 KELDYSH LV, 1968, ZH EKSP TEOR FIZ, V27, P521 KOGAN VG, 1969, PHYSICS PN JUNCTIONS, P37 KONO J, 1997, PHYS REV B, V55, P1617 LANDAU LD, 1977, QUANTUM MECH LERNER IV, 1980, ZH EKSP TEOR FIZ, V51, P588 LOZOVIK YE, 1975, JETP LETT, V22, P274 LOZOVIK YE, 1976, ZH EKSP TEOR FIZ, V44, P389 LOZOVIK YE, 1999, J EXP THEOR PHYS+, V89, P775 LOZOVIK YE, 1999, PHYS REV B, V59, P5627 NEGOITA V, 1999, PHYS REV B, V60, P2661 READ N, 1998, PHYS REV B, V58, P16262 SANTOS L, CONDMAT0005009 SHEVCHENKO SI, 1976, SOV J LOW TEMP PHYS, V2, P251 SHEVCHENKO SI, 1997, PHYS REV B, V56, P10355 VAZQUEZNAVA RA, 2000, PHYS STATUS SOLIDI B, V221, P797 VOHRALIK PF, 1990, J CHEM PHYS, V93, P3983 YU PY, 1996, FUNDAMENTALS SEMICON NR 25 TC 9 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0163-1829 J9 PHYS REV B JI Phys. Rev. B PD SEP 15 PY 2001 VL 6411 IS 11 AR 115302 DI ARTN 115302 PG 8 SC Physics, Condensed Matter GA 474ZG UT ISI:000171136700066 ER PT J AU Santoyo, E Garcia, A Morales, JM Contreras, E Espinosa-Paredes, G TI Effective thermal conductivity of Mexican geothermal cementing systems in the temperature range from 28 degrees C to 200 degrees C SO APPLIED THERMAL ENGINEERING LA English DT Article DE thermal conductivity; thermophysical properties; geothermal energy; well drilling; wellbore simulators; temperature distribution AB The effective thermal conductivity of six Mexican cementing systems used in geothermal well completion were experimentally determined in the temperature range from 28 degreesC to 200 degreesC. Measurements were carried using the classical line-source method. The experimental system was calibrated by measuring the thermal conductivity of standard fused quartz samples. An experimental procedure for preparation of the cement specimen samples was also developed. Results show that thermal conductivity depends on the particular cement system and tends to increase with temperature for most cement systems. Experimental uncertainties of thermal conductivity were less than 4%. From this experimental work, new empirical equations for correlating thermal conductivity with temperature for geothermal cementing samples were obtained. (C) 2001 Elsevier Science Ltd. All rights reserved. C1 UNAM, Ctr Invest Energia, Temixco 62580, Morelos, Mexico. RP Espinosa-Paredes, G, Univ Autonoma Metropolitana Iztapalapa, Dept Ingn Proc & Hidraul, San Rafael Atlixco 186,Apartado Postal 55-534, Mexico City 09340, DF, Mexico. CR *AM PETR I, 1990, 10 AM PETR I, P9 *AM PETR I, 1992, 5CTM API, P11 BEIRUTE RM, 1991, J PETROLEUM TECH SEP, P1140 BEVINGTON PR, 1969, DATA REDUCTION ERROR BJORNSSON G, 1990, GEOTHERMICS, V19, P17 BLACKWELL JH, 1956, CAN J PHYS, V34, P412 CONTRERAS E, 1990, J HEAT RECOVERY SYS, V10, P213 CORRE B, 1984, P 59 ANN TECHN C EXH, P12 ESPINOSAPAREDES G, 2001, UNPUB APPL THERM ENG GARCIA A, 1989, INT J THERMOPHY, V10, P1063 GOODMAN MA, 1977, WORLD OIL, V177, P81 HOLLAND FA, 1992, HEAT RECOV SYST CHP, V12, P451 MAHON KI, 1996, INT GEOL REV, V38, P293 MARSHALL DW, 1982, J CANADIAN PETRO JAN, P63 MORALES JM, 1997, THESIS U SALFORD UK PERRY RH, 1997, CHEM ENG HDB SANTOYO E, 2000, APPL THERM ENG, V21, P283 YORK D, 1969, EARTH PLANET SC LETT, V5, P320 NR 18 TC 4 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 1359-4311 J9 APPL THERM ENG JI Appl. Therm. Eng. PD DEC PY 2001 VL 21 IS 17 BP 1799 EP 1812 PG 14 SC Thermodynamics; Energy & Fuels; Engineering, Mechanical; Mechanics GA 470LL UT ISI:000170873400007 ER PT J AU Portugal, E Verma, MP TI Hydrochemistry of the geothermal brine in Cerro Prieto, Baja California, Mexico SO INGENIERIA HIDRAULICA EN MEXICO LA Spanish DT Article DE hydrochemistry; simulation; chemical equilibrium and evaporation model; lakes; Cerro Prieto; geothermal brine ID NATURAL-WATERS; MINERAL SOLUBILITIES; PREDICTION; 25-DEGREES-C; SYSTEM AB The chemical equilibrium and evaporation models are developed in order to study the reaction mechanisms and processes occurring in the stored geothermal brine in a lake at Cerro Prieto. Taking into account the different methods for activity calculations, four equilibrium models (MSPF; MCPF; M-3 y M-4) were developed The models MSPF and MCPF use the "B-dot" equations, while M-3 and M-4 use the methods for saline water According to the MSPF and MCPF models, the brine is in equilibrium with amorphous silica, and calcite is only in equilibrium at some points in the lake, whereas it is supersaturated for mineral strontianite and polymorphous silica. Similarly the evaporation model suggests that the content of chloride, sodium, potassium and calcium in the lake is controlled by evaporation. Additional processes like mixing and redox affect the concentration of magnesium and sulfate, respectively. Polynomial relations based on the chloride concentration were derived to determine the amount of evaporation in the lake. The application of this method suggested that 58% of the lake's brine was evaporated along its way: The MSPF and MCPF models provide good simulation of the brine's chemical behavior for low evaporation, while the other models. M-3 and M-4, are better for high evaporation about 90%, where the minerals halite, sylvite and anhydrite are in equilibrium. C1 Inst Invest Elect Gerencia Geotermia, Temixco 62490, Morelos, Mexico. RP Portugal, E, Inst Invest Elect Gerencia Geotermia, Ave Reforma 113,Colonia Paimira, Temixco 62490, Morelos, Mexico. CR *ERIC, 1996, EXTR RAP INF CLIM ALDROUBI A, 1980, AM J SCI, V280, P560 APPELO CAJ, 1993, GEOCHEMISTRY GROUNDW BETHKE CM, 1996, GEOCHEMICAL REACTION BEVINGTON P, 1969, DATA REDUCTION ERROR CARPENTER AB, 1978, OKLAHOMA GEOLOGICAL, V79, P60 CUSTODIO E, 1983, HIDROLOGIA SUBTERRAN DEER WA, 1982, INTRO ROCK FORMING M DREVER JI, 1988, GEOCHEMISTRY NATURAL FOURNIER RO, 1966, AM J SCI, V264, P685 FRITZ B, 1981, THESIS U L PASTEUR S GARRELS RM, 1967, ADV CHEM SER, V67, P222 GIGGENBAH WF, 1989, COLLECTION ANAL GEOT HARDIE LA, 1970, MINERALOG SOC AM SPE, V3, P273 HARDIE LA, 1991, ANNU REV EARTH PL SC, V19, P131 HARVIE CE, 1980, GEOCHIM COSMOCHIM AC, V44, P981 HARVIE CE, 1980, SCIENCE, V208, P498 HARVIE CE, 1984, GEOCHIM COSMOCHIM AC, V48, P723 HELGESON HC, 1969, AM J SCI, V267, P729 HELGESON HC, 1974, AM J SCI, V274, P1199 LICO MC, 1982, 2194 US GEOL SURV LIPPMANN MJ, 1989, P 14 WORKSH GEOHT RE, P24 MOONING C, 1984, GEOCHEM COSMOCHEM AC, V48, P571 PITZER KS, 1961, REVISADA THERMODYNAM REYES CS, 1990, CIOFIT9001 CICESE SKOUGSTAD MW, 1979, TECHNIQUES WATER RES, CHA1 STOESSELL RK, 1986, GEOCHIM COSMOCHIM AC, V50, P1465 ZHEREBTSOVA IK, 1966, GEOCHEM INT, V3, P656 NR 28 TC 1 PU INSTITUTO MEXICANO TECHNOLOGIAAGUA PI MORELOS PA APARTADO POSTAL 202, MORELOS 62550 CIVAC, MEXICO SN 0186-4076 J9 ING HIDRAUL MEX JI Ing. Hidraul. Mex. PD APR-JUN PY 2001 VL 16 IS 2 BP 153 EP 173 PG 21 SC Engineering, Civil; Water Resources GA 430DK UT ISI:000168558100012 ER PT J AU Gonzalez-Partida, E Birkle, P Torres-Alvarado, IS TI Evolution of the hydrothermal system at Los Azufres, Mexico, based on petrologic, fluid inclusion and isotopic data SO JOURNAL OF VOLCANOLOGY AND GEOTHERMAL RESEARCH LA English DT Article DE hydrothermal system; isotopic data; fluid inclusion data ID GEOTHERMAL SYSTEMS; DEPOSITS; LARDERELLO; WATERS; ORIGIN; MAGMAS; AREA AB The Los Azufres geothermal reservoir, formed in a fractured, Upper Miocene to Pliocene andesite and basalt base complex, is sealed to the surface by a silicic, mainly rhyolitic sequence of Pleistocene age. Almost the entire sequence is affected by hydrothermal alteration to varying extent. Petrological and fluid inclusion studies confirmed vertical zonation of the reservoir by secondary processes: Hydrothermal alteration processes under low temperature conditions (<170C) caused argillitization of the shallow zone of the reservoir (depth <500 m). Smectite, zeolite, calcite, and chlorite predominate the mineral assemblage in the shallow zone. At a depth of 1200-1500 m, the maximum ice melting temperatures (T-mi) values of -0.7 to -4C and salinities of 6.4 wt% NaCl eq. indicate boiling conditions of the geothermal brine in a vapor-rich zone. Chlorite, calcite, quartz, zeolite, anhydrite, albite, sphene, pyrite, hematite, and illite form the hydrothermal mineral paragenesis with maximum temperatures of 250 degreesC and pressure conditions of 150 bar. Below 1500 m, T-mi reach maximum values of -0.1 degreesC and low salinities of 0.2 wt% NaCl eq. The minerals epidote, amphibole, prehnite, and garnet indicate temperatures above 250 degreesC and pressure conditions between 150 and 200 bar. The measured homogenization temperatures (T-h) Of fluid inclusions (FI) are consistently higher than the in-situ measured temperatures, which indicates retrograde cooling of the Los Azufres geothermal reservoir since the time of the hydrothermal mineral formation. Updoming temperature isotherms at the center of the geothermal field (below well Az-9, Az-23, and Az-25) indicate the heating up of the fluids by a shallow magma chamber. Stable isotope data (delta O-18, deltaD) of the geothermal brine indicates mixing processes between meteoric water and a minor magmatic component. Secondary reactions forming sericite may have caused a further positive shift in O-18 in the shallow part of the geothermal reservoir. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Univ Nacl Autonoma Mexico, Unidad Invest Ciencias Tierra, Juriquilla, Oro, Mexico. Inst Invest Elect, Unidad Geotermia, Cuernavaca 62001, Morelos, Mexico. Univ Nacl Autonoma Mexico, Ctr Invest Energia, Temixco 62580, Morelos, Mexico. RP Gonzalez-Partida, E, Univ Nacl Autonoma Mexico, Unidad Invest Ciencias Tierra, Juriquilla, Oro, Mexico. 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Volcanol. Geotherm. Res. PD DEC 30 PY 2000 VL 104 IS 1-4 BP 277 EP 296 PG 20 SC Geosciences, Multidisciplinary GA 402DR UT ISI:000166971200015 ER PT J AU Vazquez-Nava, RA Ulloa, SE del Castillo-Mussot, M TI Excited state effects in the dielectric function of a 2D boson system SO PHYSICA STATUS SOLIDI B-BASIC RESEARCH LA English DT Article ID COUPLED QUANTUM-WELLS; MAGNETIC-FIELD; ELECTRONS; HOLES AB We present calculations for the dielectric function and collective modes of a two-dimensional interacting gas of bosons (excitons) in the xy plane which can be polarized by the application of an electric field in the z direction. previous work has explored the response of the density fluctuations while excitons lie in their intrinsic ground state. We extend the Formalism here by taking into account the internal degrees of freedom of the excitons, and their possible interplay with the density fluctuation modes of the system. In the limit of low temperature, we find collective normal modes related to the Various degrees of freedom. Our calculations of the corresponding intrinsic oscillator strength show that optical-like modes associated to the excited states become increasingly damped when temperature is raised, as the occupation factors change the overall response. C1 Univ Autonoma Estado morelos, Fac Ciencias, Cuernavaca 62000, Morelos, Mexico. Ohio Univ, Condensed Matter & Surface Sci Program, Athens, OH 45701 USA. Ohio Univ, Dept Phys & Astron, Athens, OH 45701 USA. Univ Nacl Autonoma Mexico, Inst Fis, Mexico City 01000, DF, Mexico. RP Vazquez-Nava, RA, Univ Autonoma Estado morelos, Fac Ciencias, Av Univ S-N, Cuernavaca 62000, Morelos, Mexico. CR ANDO T, 1982, REV MOD PHYS, V54, P437 BANYAI L, 1993, SERIES ATOMIC MOL OP, V2 BARDOS DC, 1994, PHYS REV B, V49, P4082 BUTOV LV, 1994, PHYS REV LETT, V73, P304 DZYUBENKO AB, 1997, JETP LETT+, V66, P617 EHRENREICH H, 1959, PHYS REV, V115, P786 FUKUZAWA T, 1990, IEEE J QUANTUM ELECT, V26, P811 FUKUZAWA T, 1990, PHYS REV LETT, V64, P3066 GIBBS HM, 1985, OPTICAL BISTABILITY HANSEN W, 1996, FESTKOR A S, V35, P81 HAUG H, 1990, QUANTUM THEORY OPTIC HINES DF, 1979, PHYS REV B, V20, P972 KACHINTSEV DM, 1994, PHYS REV B, V50, P8715 KASH JA, 1991, PHYS REV LETT, V66, P2247 KOGAN VG, 1969, PHYSICS PN JUNCTIONS, P37 KONO J, 1997, PHYS REV B, V55, P1617 LOZOVIK YE, 1976, ZH EKSP TEOR FIZ, V71, P738 MANDEL P, 1987, BISTABILITY OPTICAL NEGOITA V, 1999, PHYS REV B, V60, P2661 PEREYRA P, 2000, PHYS REV B, V61, P2128 SHEVCHENKO SI, 1976, FIZ NIZK TEMP, V2, P505 SHEVCHENKO SI, 1997, PHYS REV B, V56, P10355 SONG J, 1995, PHYS REV B, V52, P9015 WARREN M, 1987, IEEE COMPUT, V20, P68 YU PY, 1996, FUNDAMENTALS SEMICON NR 25 TC 1 PU WILEY-V C H VERLAG GMBH PI BERLIN PA PO BOX 10 11 61, D-69451 BERLIN, GERMANY SN 0370-1972 J9 PHYS STATUS SOLIDI B-BASIC RE JI Phys. Status Solidi B-Basic Res. PD OCT PY 2000 VL 221 IS 2 BP 797 EP 813 PG 17 SC Physics, Condensed Matter GA 373NB UT ISI:000165294600027 ER PT J AU Sanchez-Juarez, A Ortiz, A TI Structural properties of SnxSy thin films prepared by plasma-enhanced chemical vapor deposition SO JOURNAL OF THE ELECTROCHEMICAL SOCIETY LA English DT Article ID TIN SULFIDE FILMS; HYDROGEN-SULFIDE; SPRAY-PYROLYSIS; SINGLE-CRYSTALS; SNS; TEMPERATURE; GROWTH; DISSOCIATION; DISULFIDE; TRANSPORT AB The growth and structural properties of SnxSy (SnS2, Sn2S3) prepared by the plasma-enhanced chemical vapor deposition process have been studied systematically. SnxSy, thin films were prepared by the decomposition of H2S and SnCl4 vapors mixture in a capacitively coupled 13.56 MHz radio frequency glow discharge chamber with a radially symmetric flow pattern. Hydrogen was used as a diluent gas and for removing chlorine radicals generated by the SnCl4 decomposition. The deposition pressure, substrate temperature, and plasma power density were kept constant at 50 mTorr, 150 degrees C, and 25 mW/cm(2), respectively. The relative concentration of the precursor materials, g, defined as the ratio of tin chloride mass flow rate to the sum of tin chloride and hydrogen sulfide mass flow rates, was varied from 0 to 1.0. A total mass flow rate of 25 standard cubic centimeter per minute fur the precursor materials and the diluent gas was used in all the casts. It was found that (i) For g < 0.2, the deposited thin films contain only the 2H-SnS2 phase, and show a hexagonal crystalline structure with a preferential growth of the c axes perpendicular to the plane of the substrate; (ii) For 0.2 less than or equal to g < 0.5, and g > 0.6, the deposited films contain a mixture of hexagonal SnS2 and orthorhombic Sn2S3 compounds; and (iii) For g close to 0.5, the deposited material has only the Sn2S3 compound. In all the samples, the size of the crystallites and the lattice parameters were estimated from the width of the X-ray diffraction peaks and the interplanar distances. It was found that the chemical composition, the crystallinity, and the preferential growth of the deposited material are well controlled by adjusting the value of g. (C) 2000 The Electrochemical Society. S0013-4651(00)02-060-7. All rights reserved. C1 Univ Nacl Autonoma Mexico, Energy Res Ctr, Dept Solar Mat, Temixco 62580, Morelos, Mexico. Univ Nacl Autonoma Mexico, Mat Res Inst, Mexico City 04510, DF, Mexico. RP Sanchez-Juarez, A, Univ Nacl Autonoma Mexico, Energy Res Ctr, Dept Solar Mat, Temixco 62580, Morelos, Mexico. CR ALBERS W, 1960, J PHYS CHEM SOLIDS, V15, P306 ALBERS W, 1961, J APPL PHYS, V32, P2220 ALONSO JC, 1998, J VAC SCI TECHNOL A, V16, P1 ARORA SK, 1994, J MATER SCI, V29, P3979 BUSCH G, 1961, HELV PHYS ACTA, V34, P359 CHAPMAN B, 1980, GLOW DISCHARGE PROCE CHATTOPADHYAY T, 1986, J PHYS CHEM SOLIDS, V44, P879 DOMINGO G, 1966, PHYS REV, V143, P536 ENGELKEN RD, 1987, J ELECTROCHEM SOC, V134, P2696 GEORGE J, 1983, J CRYST GROWTH, V63, P233 KLUG HP, 1954, XRAY DIFFRACTION PRO KOURTAKIS K, 1988, J SOLID STATE CHEM, V76, P186 LIDE DR, 1991, CRC HDB CHEM PHYSICS LIEBERMAN MA, 1994, PRINCIPLES PLASMA DI LOFERSKY JJ, 1956, J APPL PHYS, V27, P77 LOPEZ S, 1994, SEMICOND SCI TECH, V9, P1 LOPEZ S, 1996, SEMICOND SCI TECH, V11, P433 MOOSER E, 1956, PHYS REV, V101, P492 NAIR MTS, 1991, SEMICOND SCI TECH, V6, P132 NAIR PK, 1991, J PHYS D APPL PHYS, V24, P83 ORTIZ A, 1996, SEMICOND SCI TECH, V11, P243 PARENTEAU M, 1990, PHYS REV B, V41, P5227 RAY SC, 1999, THIN SOLID FILMS, V350, P72 REDDY NK, 1997, P 26 IEEE PHOT SPEC, P515 REDDY NK, 1998, THIN SOLID FILMS, V325, P4 SAID G, 1973, PHYS STATUS SOLIDI, V15, P99 SCHONHERR E, 1975, J CRYST GROWTH, V30, P96 SHIBATA T, 1991, J MATER SCI, V26, P5107 SOLOMON I, 1988, PHYS REV B, V38, P9895 TRAUS I, 1992, PLASMA CHEM PLASMA P, V12, P275 TRAUS I, 1993, PLASMA CHEM PLASMA P, V13, P77 VALIUKONIS G, 1986, PHYS STATUS SOLIDI B, V135, P299 VONENGEL A, 1965, IONIZED GASES WANG C, 1986, PHILOS MAG B, V53, P183 WHITEHOUSE CR, 1979, J CRYST GROWTH, V47, P203 ZAINAL Z, 1996, SOL ENERG MAT SOL C, V40, P347 NR 36 TC 4 PU ELECTROCHEMICAL SOC INC PI PENNINGTON PA 65 SOUTH MAIN STREET, PENNINGTON, NJ 08534 USA SN 0013-4651 J9 J ELECTROCHEM SOC JI J. Electrochem. Soc. PD OCT PY 2000 VL 147 IS 10 BP 3708 EP 3717 PG 10 SC Electrochemistry; Materials Science, Coatings & Films GA 359GJ UT ISI:000089602900022 ER PT J AU Albarran, JL Campillo, B Constantino, ME TI Precipitation and hardening mechanisms of an ion nitrided H-12 tool steel SO SURFACE ENGINEERING LA English DT Article AB In order to investigate the combined effects of tempering and ion nitriding on H-12 tool steel, specimens were tempered at 550 and 580 degrees C and subsequently ion nitrided at 500 degrees C for various times. The effect of the specimen treatments was analysed by microhardness testing, fractography, X-ray diffractometry, and transmission electron microscopy (TEM). A linear increase in the surface microhardness was observed up to 27 ks, however at longer times the surface microhardness decreased. The hardness increase is related to precipitation of iron nitrides, chromium carbonitrides, and tungsten carbides. The maximum hardness reached correlated with the maximum numbers of chromium carbonitrides and tungsten carbides, as demonstrated by the X-ray diffraction analysis. The TEM study shows that the increase is mainly a result of the coherent precipitation of W2C in an Fe4N matrix. Also, TEM observations reveal that in specimens nitrided for shorter times (9 and 18 ks) martensite is transformed into the nitride Fe16N2 (alpha "). The microhardness decrease observed in specimens treated for longer times is caused by loss of toughness in the grain boundaries. C1 UNAM, Ctr Ciencias Fis, Cuernavaca 62251, Morelos, Mexico. RP Albarran, JL, UNAM, Ctr Ciencias Fis, POB 48-3, Cuernavaca 62251, Morelos, Mexico. CR FERGUSON P, 1984, SCRIPTA METALL, V18, P1189 OZBAYSAL K, 1986, MATER SCI ENG, V78, P179 REMBGES W, 1993, HEAT TREAT, V8, P20 STRAVER WTM, 1984, METALL TRANS A, V15, P627 NR 4 TC 0 PU MANEY PUBLISHING PI LEEDS PA HUDSON RD, LEEDS LS9 7DL, ENGLAND SN 0267-0844 J9 SURF ENG JI Surf. Eng. PY 2000 VL 16 IS 4 BP 333 EP 336 PG 4 SC Materials Science, Coatings & Films GA 356NN UT ISI:000089449500010 ER PT J AU Mackie, AD Hernandez-Cobos, J Vega, LF TI Predicting liquid-vapour equilibria for water using an ab-initio potential from histogram reweighting Monte Carlo simulations SO MOLECULAR SIMULATION LA English DT Article DE vapour liquid equilibria; water; histogram reweighting ID NONADDITIVITY; 25-DEGREES-C AB The coexisting densities for an ab-initio model for water have been calculated using grand canonical Monte Carlo simulations with the histogram reweighting technique. Although good agreement with experimental data is found for the radial distribution function at room temperature, the predicted critical density and temperature are well below both the experimental value as well as predictions from semi-empirical potentials. Improvement in the repulsive part of the nb-initio potential is suggested as a way to obtain better agreement with experiment. C1 ETSEQ Univ Rovira & Virgili, Dept Enginyeria, Tarragona, Spain. UNAM, Ctr Ciencias Fis, Cuernavaca, Morelos, Mexico. RP Mackie, AD, ETSEQ Univ Rovira & Virgili, Dept Enginyeria, Tarragona, Spain. CR BERENDSEN HJC, 1981, INTERMOLECULAR FORCE, P331 BERENDSEN HJC, 1987, J PHYS CHEM-US, V91, P6269 CLEMENTI E, 1980, INT J QUANTUM CHEM, V17, P377 FERRENBERG AM, 1988, PHYS REV LETT, V61, P2635 FERRENBERG AM, 1989, PHYS REV LETT, V63, P1195 GILADALID L, COMMUNICATION KIYOHARA K, 1998, MOL PHYS, V94, P803 MACKIE AD, 1999, J CHEM PHYS, V111, P2103 MATSUOKA O, 1976, J CHEM PHYS, V64, P1351 SAINTMARTIN H, 1990, J CHEM PHYS, V93, P6448 SOPER AK, 1986, CHEM PHYS, V107, P47 STRAUCH HJ, 1992, J CHEM PHYS, V96, P864 NR 12 TC 3 PU GORDON BREACH SCI PUBL LTD PI READING PA C/O STBS LTD, PO BOX 90, READING RG1 8JL, BERKS, ENGLAND SN 0892-7022 J9 MOL SIMULAT JI Mol. Simul. PY 2000 VL 24 IS 1-3 BP 63 EP 69 PG 7 SC Chemistry, Physical; Physics, Atomic, Molecular & Chemical GA 355VK UT ISI:000089409100005 ER PT J AU Rivera, W Romero, RJ TI Evaluation of a heat transformer powered by a solar pond SO SOLAR ENERGY MATERIALS AND SOLAR CELLS LA English DT Article DE heat transformers; solar ponds ID EXPERIMENTAL PERFORMANCE AB A single-stage heat transformer operating with the water/lithium bromide mixture was operated to demonstrate the feasibility of the use of these systems to increase the temperature of the heat obtained from solar ponds. Electrical heaters at temperatures not higher than 80 degrees C were used to simulate the heat input to an absorption heat transformer from a solar pond. Gross temperature lifts, useful heat and coefficients of performance are plotted for the heat transformer against temperatures and solution concentrations. Gross temperature lifts as high as 44 degrees C were obtained. The maximum temperature of the useful heat produced by the heat transformer operating with the water/lithium bromide mixture was 124 degrees C. The maximum coefficient of performance for the unit was 0.16. (C) 2000 Elsevier Science B.V. All rights reserved. C1 UNAM, Ctr Invest Energia, Temixco 65280, Morelos, Mexico. RP Rivera, W, UNAM, Ctr Invest Energia, POB 34, Temixco 65280, Morelos, Mexico. CR BARRAGAN RM, 1996, INT J ENERG RES, V20, P651 BARRAGAN RM, 1998, INT J ENERG RES, V22, P73 GOMMED K, 1988, SOL ENERGY, V41, P81 MASHIMO K, 1987, P IEA HEAT PUMP C CH, P271 MOHAMAD BES, 1982, THESIS U SALFORD UK TABOR H, 1981, SOL ENERGY, V27, P181 NR 6 TC 5 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0927-0248 J9 SOLAR ENERG MATER SOLAR CELLS JI Sol. Energy Mater. Sol. Cells PD AUG 31 PY 2000 VL 63 IS 4 BP 413 EP 422 PG 10 SC Energy & Fuels; Materials Science, Multidisciplinary GA 350HR UT ISI:000089095600012 ER PT J AU Garcia-Garibay, M Lopez-Munguia, A Barzana, E TI Alcoholysis and reverse hydrolysis reactions in organic one-phase system with a hyperthermophilic beta-glycosidase SO BIOTECHNOLOGY AND BIOENGINEERING LA English DT Article DE alcoholysis; reverse hydrolysis; hyperthermophilic beta-glycosidase; organic phase enzymatic reaction ID ENZYMATIC-SYNTHESIS; GLUCOSIDE SYNTHESIS; 2-PHASE SYSTEM; WATER ACTIVITY; SOLVENTS; XYLOSIDASE; CONDENSATION AB Alcoholysis and reverse hydrolysis reactions were performed enzymatically in one-phase water-saturated 1-heptanol systems. Lactose or glucose was used as substrate to produce heptyl-beta-galactoside and/or heptyl-beta-glucoside, respectively. When alcoholysis of lactose was performed at 37 degrees C with beta-galactosidase from Escherichia coli, the initial rate was 14 nmol/mL min, and the limiting factors were the poor solubility of the substrate in 1-heptanol and low thermal stability of the enzyme. When a hyperthermophilic beta-glycosidase was used at 90 degrees C, the rate was 3.14-fold higher; in this case a higher concentration of soluble lactose in the water-saturated heptanol was available to the enzyme due to the higher temperature. The hyperthermophilic beta-glycosidase was also able to use glucose and galactose as substrates to achieve the reverse hydrolysis reaction. As a consequence, when lactose was used as substrate, heptyl-beta-galactoside was formed by alcoholysis, while the released glucose moiety was used in a secondary reverse hydrolysis reaction to produce heptyl-beta-glucoside. Both reactions followed Michaelis-Menten kinetics behavior. Neither lactose nor heptyl glycosides were hydrolyzed by this enzyme in water-saturated heptanol. However, the conversion was limited by a strong product inhibition and the formation of oligosaccharides, especially at high substrate concentrations, reducing the final glycoside yield. (C) 2000 John Wiley & Sons, Inc. C1 Univ Nacl Autonoma Mexico, Fac Quim, Dept Alimentos & Biotechnol, Mexico City 04510, DF, Mexico. Univ Autonoma Metropolitana Iztapalapa, Dept Biotecnol, Mexico City 09340, DF, Mexico. Univ Nacl Autonoma Mexico, Inst Biotecnol, Dept Bioingn, Cuernavaca 62210, Morelos, Mexico. RP Barzana, E, Univ Nacl Autonoma Mexico, Fac Quim, Dept Alimentos & Biotechnol, Mexico City 04510, DF, Mexico. CR BEECHER JE, 1990, ENZYME MICROB TECH, V12, P955 BELL G, 1995, TRENDS BIOTECHNOL, V13, P468 CHAHID Z, 1992, BIOTECHNOL LETT, V14, P281 CHAHID Z, 1994, BIOTECHNOL LETT, V16, P795 DORDICK JS, 1991, CURR OPIN BIOTECH, V2, P401 GARCIAGARIBAY M, 1996, REV INVEST CLIN S, V48, P51 KLIBANOV AM, 1989, TRENDS BIOCHEM SCI, V14, P141 LAROUTE V, 1992, BIOTECHNOL LETT, V14, P169 LJUNGER G, 1994, ENZYME MICROB TECH, V16, P751 MATSUMURA S, 1990, J AM OIL CHEM SOC, V67, P996 PANINTRARUX C, 1995, ENZYME MICROB TECH, V17, P32 PANINTRARUX C, 1997, BIOTECHNOL LETT, V19, P899 SHINOYAMA H, 1988, AGR BIOL CHEM TOKYO, V52, P2197 SHINOYAMA H, 1988, AGR BIOL CHEM TOKYO, V52, P2375 SHINOYAMA H, 1991, AGR BIOL CHEM TOKYO, V55, P1679 SHINOYAMA H, 1991, B CHEM SOC JPN, V64, P291 TRICONE A, 1991, BIOTECHNOL LETT, V13, P235 VIC G, 1997, ENZYME MICROB TECH, V20, P597 VULFSON EN, 1990, BIOTECHNOL LETT, V12, P397 VULFSON EN, 1990, ENZYME MICROB TECH, V12, P950 WALLENFELS K, 1961, ADV CARBOHYD CHEM, V16, P239 WALLENFELS K, 1972, ENZYMES, V7, P617 NR 22 TC 6 PU JOHN WILEY & SONS INC PI NEW YORK PA 605 THIRD AVE, NEW YORK, NY 10158-0012 USA SN 0006-3592 J9 BIOTECHNOL BIOENG JI Biotechnol. Bioeng. PD SEP 20 PY 2000 VL 69 IS 6 BP 627 EP 632 PG 6 SC Biotechnology & Applied Microbiology GA 349AY UT ISI:000089022700006 ER PT J AU Chandrasekharam, D Vaselli, O Sheth, HC Keshav, S TI Petrogenetic significance of ferro-enstatite orthopyroxene in basaltic dikes from the Tapi rift, Deccan flood basalt province, India SO EARTH AND PLANETARY SCIENCE LETTERS LA English DT Article DE assimilation; flood basalts; Deccan Plateau; dikes; orthopyroxene; igneous rocks; genesis ID TRAPS AB Some basaltic dikes from the Tapi rift in the Deccan flood basalt province, India, contain abundant clusters of prismatic quench crystals of ferro-enstatite orthopyroxene (Fe39-42Mg53-57Ca2-4) Such profuse orthopyroxene clusters are not yet known from any other flood basalt province in the world. Based on petrography, mineral chemistry and whole-rock chemistry, we conclude that these crystals are formed due to assimilation of shale by Deccan basalt magma. This interpretation is consistent with the known bedrock geology of the area. These quench crystals constitute the first direct, petrographic evidence for crustal contamination in the Deccan province. The liquidus temperature for the dikes is estimated at 1220 +/- 10 degrees C, with the crystallization temperature of the orthopyroxene at 1080 degrees C or less. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Indian Inst Technol, Dept Earth Sci, Bombay 400076, Maharashtra, India. Univ Florence, Dept Earth Sci, I-50121 Florence, Italy. Univ Nacl Autonoma Mexico, Ctr Invest Energia, Temixco 62580, Morelos, Mexico. Florida Int Univ, Dept Geol, Miami, FL 33199 USA. RP Chandrasekharam, D, Indian Inst Technol, Dept Earth Sci, Bombay 400076, Maharashtra, India. CR BENCE AE, 1968, J GEOL, V76, P382 BOWEN NL, 1928, EVOLUTION IGNEOUS RO CAMPBELL IH, 1985, CONTRIB MINERAL PETR, V20, P244 CHANDRASEKHARAM D, 1999, J VOLCANOL GEOTH RES, V93, P111 COHEN TH, 1994, VOLCANISM, P173 COX KG, 1979, INTERPRETATION IGNEO DAVIDSON PM, 1989, AM MINERAL, V74, P18 DEER WA, 1992, INTRO ROCK FORMING M GOVINDARAJU K, 1989, GEOSTANDARD NEWSLETT, V13, P1 HALL A, 1988, IGNEOUS PETROLOGY ISHII T, 1975, MINERALOG J JAPAN, V8, P48 KAILA KL, 1988, GEOLOGICAL SOC INDIA, V10, P91 KESHAV S, 1998, CURR SCI INDIA, V74, P252 KRISHNAMURTHY P, 1980, CONTRIB MINERAL PETR, V73, P179 LIGHTFOOT PC, 1990, J PETROL, V31, P1165 LONGHI J, 1981, WORKSH MAGM PROC EAR, P90 MAHONEY JJ, 1988, CONTINENTAL FLOOD BA, P151 MCBIRNEY AR, 1984, IGNEOUS PETROLOGY MELLUSO L, 1995, J PETROL, V36, P1393 MELLUSO L, 1999, MEM GEOL SOC INDIA, V43, P735 PENG ZX, 1994, GEOCHIM COSMOCHIM AC, V58, P267 PHILPOTTS AR, 1990, PRINCIPLES IGNEOUS M SANT DA, 1990, MAFIC DYKES EMPLACEM, P383 SEN G, 1986, J PETROL, V27, P627 SEN G, 2000, COMMUNICATION SETHNA SF, 1988, MEM GEOL SOC INDIA, V10, P69 SHETH HC, 1997, CURR SCI INDIA, V72, P755 SHETH HC, 1997, PHYS EARTH PLANET IN, V99, P179 SUN SS, 1989, GEOL SOC SPEC PUBL, V42, P313 TURNER FJ, 1961, IGNEOUS METAMORPHIC WADIA DN, 1975, GEOLOGY INDIA WEAVER JS, 1990, COMPUT GEOSCI, V16, P1 NR 32 TC 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0012-821X J9 EARTH PLANET SCI LETT JI Earth Planet. Sci. Lett. PD JUL 15 PY 2000 VL 179 IS 3-4 BP 469 EP 476 PG 8 SC Geochemistry & Geophysics GA 334YG UT ISI:000088213600004 ER PT J AU Pattabi, M Castellanos, RH Sebastian, PJ Mathew, X TI A novel electrocatalyst based on W-x(CO)(n) for oxygen reduction reaction SO ELECTROCHEMICAL AND SOLID STATE LETTERS LA English DT Article AB A novel electrocatalyst based on W-x(CO)(n) was synthesized from W(CO)(6) in xylene at 140 degrees C. Linear voltametry studies revealed significant catalytic activity for the material for the oxygen reduction reaction. Koutecky-Levich analysis of the voltametry data showed that the reaction follows first-order kinetics and the value of the Koutecky-Levich slope indicates a multielectron charge transfer during the oxygen reduction reaction. The value of the Tafel slope was -120 mV/decade from the mass transfer corrected Tafel plots. The charge-transfer coefficient and exchange current density were 0.66 and 8.4 x 10(-5) A/cm(2), respectively. (C) 2000 The Electrochemical Society. S1099-0062(00)05-082-3. All rights available. C1 UNAM, CIE, Solar Mat Dept, Temixco 62580, Morelos, Mexico. RP Sebastian, PJ, UNAM, CIE, Solar Mat Dept, Temixco 62580, Morelos, Mexico. CR ALONSOVANTE N, 1986, NATURE, V323, P431 ALONSOVANTE N, 1987, J AM CHEM SOC, V109, P3251 BARD AJ, 1980, ELECTROCHEMICAL METH CASTELLANOS RH, 1998, INT J HYDROGEN ENERG, V23, P1037 FOURNIER J, 1997, J ELECTROCHEM SOC, V144, P145 ROMERO T, 1999, J NEW MAT ELECT SYST, V2, P111 SASIKUMAR G, 1995, ELECTROCHIM ACTA, V40, P285 SAVADOGO O, 1996, J ELECTROCHEM SOC, V143, P1814 NR 8 TC 4 PU ELECTROCHEMICAL SOC INC PI PENNINGTON PA 65 SOUTH MAIN STREET, PENNINGTON, NJ 08534 USA SN 1099-0062 J9 ELECTROCHEM SOLID STATE LETT JI Electrochem. Solid State Lett. PD SEP PY 2000 VL 3 IS 9 BP 431 EP 432 PG 2 SC Electrochemistry; Materials Science, Multidisciplinary GA 335TN UT ISI:000088261000011 ER PT J AU Bello-Perez, LA Romero-Manilla, R Paredes-Lopez, O TI Preparation and properties of physically modified banana starch prepared by alcoholic-alkaline treatment SO STARCH-STARKE LA English DT Article DE starch; banana; modification, functional properties; physicochemical properties ID AMYLOSE; GELATION AB Granular cold-water-soluble (GCWS) starches were prepared from banana starch treating it with 40 and 60%; aqueous ethanol at two controlled temperatures (25 and 35 degrees C). GCWS starches prepared at 25 degrees C and with 40 and 60% aqueous ethanol had the lowest cold-water solubility. that prepared with 40% aqueous ethanol at 35 degrees C and stored at room temperature showed]low tendency to retrogradation, as assessed by transmittance. solubility and swelling profiles were similar for GCWS starches and the freeze-thaw stability of GCWS starches was increased as compared with native starch. The apparent viscosity of GCWS banana starches was higher than that of its native starch counterpart. C1 Inst Tecnol Acapulco, Acapulco 39905, Guerrero, Mexico. IPN, Ctr Desarrollo Prod Biot, Yautepec 45000, Morelos, Mexico. IPN, Ctr Invest & Estudios Avanzados, Guanajuato 36500, Mexico. RP Bello-Perez, LA, Inst Tecnol Acapulco, Av Inst Tecnol,S-N Crucero Cayaco Puerto Marques, Acapulco 39905, Guerrero, Mexico. CR *AACC, 1983, APPR METH AN AGBOOLA SO, 1991, STARCH-STARKE, V43, P62 BELLOPEREZ LA, 1999, J AGR FOOD CHEM, V47, P854 BILIADERIS CG, 1991, CAN J PHYSIOL PHARM, V69, P60 BRYANT CM, 1997, CEREAL CHEM, V74, P171 CHEN J, 1994, CEREAL CHEM, V71, P618 CHEN J, 1994, CEREAL CHEM, V71, P622 CLARK AH, 1989, MACROMOLECULES, V22, P346 COUSIDINE DM, 1982, FOODS FOOD PRODUCTIO, P142 DELLAVALLE G, 1996, J RHEOL, V40, P347 DOUBLIER JL, 1986, CEREAL CHEM, V63, P240 DUBOIS M, 1956, ANAL CHEM, V28, P350 EASTMAN JE, 1984, 4465702, US FLECHE G, 1985, STARCH CONVERSION TE, P73 FRENCH D, 1984, STARCH CHEM TECHNOLO, P183 GIDLEY MJ, 1987, CARBOHYD RES, V161, P301 GILBERT GA, 1964, METHODS CARBOHYDRATE, V4, P168 IMBERTY A, 1988, BIOPOLYMERS, V27, P1205 KAYISU K, 1981, J FOOD SCI, V46, P1885 KIM YS, 1995, J FOOD SCI, V60, P1060 LIGHT JM, 1990, CEREAL FOOD WORLD, V35, P1081 LII CY, 1982, J FOOD SCI, V47, P1493 MILES MJ, 1985, CARBOHYD RES, V135, P257 MILES MJ, 1985, CARBOHYD RES, V135, P271 NR 24 TC 11 PU WILEY-V C H VERLAG GMBH PI BERLIN PA MUHLENSTRASSE 33-34, D-13187 BERLIN, GERMANY SN 0038-9056 J9 STARCH JI Starch-Starke PD MAY PY 2000 VL 52 IS 5 BP 154 EP 159 PG 6 SC Food Science & Technology GA 333EN UT ISI:000088116400004 ER PT J AU Verma, SP Garcia, R Santoyo, E Aparicio, A TI Improved capillary electrophoresis method for measuring rare-earth elements in synthetic geochemical standards SO JOURNAL OF CHROMATOGRAPHY A LA English DT Article DE geochemistry; rare earth elements; lanthanides; metal cations ID PERFORMANCE LIQUID-CHROMATOGRAPHY; CHELATION ION CHROMATOGRAPHY; ZONE-ELECTROPHORESIS; MASS-SPECTROMETRY; SEPARATION EFFICIENCY; GEOLOGICAL-MATERIALS; REFERENCE SAMPLES; LANTHANIDES; ROCKS; YTTRIUM AB An improved capillary electrophoresis (CE) method for quantifying rare-earth elements (REEs) in synthetic geochemical standards was developed. Synthetic standard solutions were obtained from high purity metal oxides. The separation of REE total group (lanthanum to lutetium) was defined as a primary objective. Special attention was also focused on the optimized separation of europium (Eu) and gadolinium (Gd) because in earlier applications they presented overlapping problems. Their separation and quantitative determinations are essential for geological applications. For the rapid separation of REEs in synthetic geochemical standards, the temperature of the separation device was optimized. An analysis temperature of 15 degrees C enabled both the rapid separation of REEs within 2 min and the overlapping problem of Eu-Gd to be resolved. The detection limits (<0.1 ng) and precision estimates (generally better than 5%) were found to be satisfactory for most geological applications. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Univ Nacl Autonoma Mexico, Ctr Invest Energia, Temixco 62580, Morelos, Mexico. CSIC, Museo Nacl Ciencias Nat, Dept Volcanol, E-28006 Madrid, Spain. RP Verma, SP, Univ Nacl Autonoma Mexico, Ctr Invest Energia, Priv Xochicalso S-N,Col Ctr,Apartado Postal 34, Temixco 62580, Morelos, Mexico. CR ALMEREY R, 1991, J RADIOAN NUCL CH LE, V153, P221 BOTTAZZI P, 1991, GEOSTANDARD NEWSLETT, V15, P51 CASSIDY RM, 1981, J LIQ CHROMATOGR, V4, P379 CASSIDY RM, 1988, CHEM GEOL, V67, P185 FORET F, 1990, ELECTROPHORESIS, V11, P780 GJERDE DT, 1987, ION CHROMATOGRAPHY GOVINDARAJU K, 1994, GEOSTANDARD NEWSLETT, V18, P1 GUTTMAN A, 1996, TRAC-TREND ANAL CHEM, V15, P194 HADDAD PR, 1990, J CHROMATOGRAPHY LIB, V46 HADDAD PR, 1997, J CHROMATOGR A, V770, P281 HEBERLING SS, 1987, RES DEV SEP, P74 HENDERSON P, 1984, RARE EARTH ELEMENT G JARVIS KE, 1988, CHEM GEOL, V68, P31 LU HT, 1997, TALANTA, V45, P119 MA S, 1998, J CHROMATOGR A, V825, P55 MACKA M, 1998, J CHROMATOGR A, V803, P279 MAO Q, 1998, J CHROMATOGR A, V802, P203 MAZZUCOTELLI A, 1985, J CHROMATOGR, V349, P137 NESTERENKO PN, 1998, J CHROMATOGR A, V804, P223 RAMANAIAH GV, 1998, TALANTA, V46, P533 ROLLINSON HR, 1993, USING GEOCHEMICAL DA SMALL H, 1975, ANAL CHEM, V47, P1801 TERAKADO Y, 1998, GEOCHIM COSMOCHIM AC, V62, P1903 VERMA SP, 1991, ACTIN RES, V3, P237 VERMA SP, 1991, GEOSTANDARD NEWSLETT, V15, P129 WEISS J, 1995, ION CHROMATOGRAPHY NR 26 TC 16 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0021-9673 J9 J CHROMATOGR A JI J. Chromatogr. A PD JUL 7 PY 2000 VL 884 IS 1-2 BP 317 EP 328 PG 12 SC Biochemical Research Methods; Chemistry, Analytical GA 330AJ UT ISI:000087940400034 ER PT J AU Fernandez, AM Merino, MG TI Preparation and characterization of Sb2Se3 thin films prepared by electrodeposition for photovoltaic applications SO THIN SOLID FILMS LA English DT Article DE antimonium selenide; deposition process; thin films; X-ray diffraction ID DEPENDENCE AB Thin films of semiconductors are commonly used for the fabrication of cost-effective solar cells. Sb2Se3 thin films are suitable for use as absorber films in the polycrystalline thin film forms solar cells. The aim of the present study is to analyze die different experimental conditions to prepare Sb2Se3 film using electrodeposition process. The differences in the structural and compositional properties of the film before and after heat treatment in N-2 atmosphere are also investigated. The electrodeposited films were characterized using X-ray diffraction, scanning electron microscopy (SEM) and electron probe microanalysis (EPMA). Sb2Se3 (JCPDS 15861), Sb (JCPDS 5562) and Se (JCPDS 27603) were found after the films are annealed at 300 degrees C. The optical bandgap value of the film was estimated as 2.00 eV from the optical spectral analyses. (C) 2000 Published by Elsevier Science S.A. All rights reserved. C1 UNAM, Ctr Invest Energia, Col Ctr, Temixco 62580, Morelos, Mexico. RP Fernandez, AM, UNAM, Ctr Invest Energia, Col Ctr, Av Xochicalco S-N, Temixco 62580, Morelos, Mexico. CR BRAITTACHAYRA RN, 1951, SOLAR ENERGY MAT, V64, P274 BRANSEN D, 1974, NONCRYST SOLIDS, V15, P395 HANSEN M, CONSTITUTION BIANARY, P1172 KAITO C, 1998, THIN SOLID FILMS, V312, P93 MADELUNG O, 1992, SEMICONDUCTORS OTHER PLATAKIS NS, 1972, PHYS STATUS SOLIDI A, V13, K1 RAJAPURE K, 1997, THIN SOLID FILMS, V311, P114 WATANABE K, 1983, J APPL PHYS, V54, P1256 ZAYED HA, 1994, INDIAN J PURE AP PHY, V32, P334 ZAYED HA, 1994, THIN SOLID FILMS, V247, P94 NR 10 TC 18 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0040-6090 J9 THIN SOLID FILMS JI Thin Solid Films PD MAY 1 PY 2000 VL 366 IS 1-2 BP 202 EP 206 PG 5 SC Materials Science, Multidisciplinary; Materials Science, Coatings & Films; Physics, Applied; Physics, Condensed Matter GA 314VT UT ISI:000087078800034 ER PT J AU Verma, MP TI Chemical thermodynamics of silica: a critique on its geothermometer SO GEOTHERMICS LA English DT Article DE chemical thermodynamics; quartz solubility; PVT characteristics of water; quartz geothermometer; Cerro Prieto; Mexico ID SODIUM-CHLORIDE SOLUTIONS; QUARTZ SOLUBILITY; SYSTEM NA2O-K2O-CAO-MGO-FEO-FE2O3-AL2O3-SIO2-TIO2-H2O-CO2; SUPERCRITICAL H2O; DISSOLUTION; 25-DEGREES-C; TEMPERATURE; IONIZATION; EQUILIBRIA; KINETICS AB The chemical thermodynamic concepts used in the calculation of solubility data of silica (quartz) are presented taking into account the PVT characteristics of water. The temperature-dependcnce trends between the thermodynamically calculated and the experimental quartz solubility data are very similar, but the values are widely different at high temperatures. The experimental solubility, especially along the saturation curve at high temperature and thermodynamic data for silica need to be reevaluated in order to use silica chemistry to understand geological processes. There could exist a wide range of values for silica solubility at a specified temperature, depending upon the amount of water in the reaction vessel. Thus the silica contents in geothermal fluid, in general, cannot be used as a geothermometer to estimate the reservoir temperature. The derivation of a silica geothermometer needs an extra assumption about the total amount of water in the system. The solubility data for the two extreme cases, i.e. when the vessel (bomb) is completely filled with water and when there is just enough water to make the total specific volume equal to the critical volume of water at room temperature (25 degrees C), are considered here, These lie on the two respective straight lines of log (SiO2(ppm)) against temperature (K). The equations for the two straight lines are log (SiO2 (ppm)) = 0.0179 T (K)-4.3214 and log SiO2 (ppm) = 0.0088 T (K)-1.6513, respectively. In the case of the well M-19A at Cerro Prieto, the silica concentration in the reservoir liquid is higher than the experimental solubility, but is lower than the calculated solubility value. (C) 2000 CNR. Published by Elsevier Science Ltd. All rights reserved. C1 Geotermia, Inst Invest Elect, Cuernavaca 62001, Morelos, Mexico. RP Verma, MP, Geotermia, Inst Invest Elect, Apdo 1-475, Cuernavaca 62001, Morelos, Mexico. CR ALEXANDER GB, 1954, J PHYS CHEM-US, V58, P453 ANDERSON GM, 1965, AM J SCI, V263, P494 ANDERSON GM, 1967, AM J SCI, V265, P12 ARNORSSON S, 1970, GEOTHERMICS, V2, P536 ARNORSSON S, 1975, AM J SCI, V275, P763 ARNORSSON S, 1985, GEOTHERM RESOUR COUN, V9, P293 ARNORSSON S, 1985, J VOLCANOL GEOTH RES, V23, P299 BECKWITH RS, 1969, GEOCHIM COSMOCHIM AC, V33, P745 BENNETT PC, 1991, GEOCHIM COSMOCHIM AC, V55, P1781 BERMAN RG, 1985, CONTRIB MINERAL PETR, V89, P168 BERMAN RG, 1988, J PETROL, V29, P445 BODVARSSON G, 1960, B VOLCANOL SER, V2, P241 BODVARSSON G, 1961, P UN C NEW SOURC E G, V24, P82 BRADY EL, 1953, J PHYS CHEM-US, V57, P706 BRISCO HVA, 1936, I MIN METALL T, V46, P291 BUSEY RH, 1977, INORG CHEM, V16, P2444 DAMORE F, 1987, GEOTHERMICS, V16, P271 DOVE PM, 1990, GEOCHIM COSMOCHIM AC, V54, P955 DOVE PM, 1992, GEOCHIM COSMOCHIM AC, V56, P4147 FAUSTO JJ, 1979, 2 S CERR PRIET GEOTH, P199 FLEMING BA, 1982, GEOTHERMICS, V11, P15 FOURNIER RO, 1962, AM MINERAL, V47, P897 FOURNIER RO, 1966, AM J SCI, V264, P685 FOURNIER RO, 1970, GEOTHERMICS, V2, P529 FOURNIER RO, 1973, 1970 P INT S HYDR BI, V1, P122 FOURNIER RO, 1974, US GEOL SURV J RES, V2, P263 FOURNIER RO, 1977, GEOTHERMICS, V5, P41 FOURNIER RO, 1982, GEOCHIM COSMOCHIM AC, V46, P1969 FOURNIER RO, 1982, GEOTHERMAL RES COUNC, V11, P3 FOURNIER RO, 1983, GEOCHIM COSMOCHIM AC, V47, P579 FOURNIER RO, 1983, GEOCHIM COSMOCHIM AC, V47, P587 FOURNIER RO, 1989, LECT GEOCH INT HYDR, P21 FRANCK EU, 1956, Z PHYS CHEM, V6, P345 FREDERICKSON AF, 1954, AM MINERAL, V39, P886 GISLASON SR, 1993, CHEM GEOL, V107, P363 GISLASON SR, 1997, GEOCHIM COSMOCHIM AC, V61, P1193 GRATZ AJ, 1993, GEOCHIM COSMOCHIM AC, V57, P965 GREENBERG SA, 1958, J AM CHEM SOC, V80, P6508 HAAR L, 1984, NBS NRC STEAM TABLES HEMLEY JJ, 1980, ECON GEOL, V75, P210 HENLEY RW, 1984, REV EC GEOL, V1, P267 HOLLAND TJB, 1990, J METAMORPH GEOL, V8, P89 ILER R, 1979, CHEM SILICA SOLUBILI JASMUND K, 1952, J GEOL, V6, P595 KENNEDY GC, 1950, ECON GEOL, V45, P629 KITAHARA S, 1960, REV PHYS CHEM JAPAN, V30, P109 KRAUSKOPF KB, 1956, GEOCHIM COSMOCHIM AC, V10, P1 LAUDISE RA, 1961, J PHYS CHEM-US, V65, P1396 LEVITTE D, 1979, GEOTHERMICS, V7, P1 MAHON WAJ, 1966, NZ J SCI, V9, P135 MOREY GW, 1962, GEOCHIM COSMOCHIM AC, V26, P1029 MOREY GW, 1964, J GEOPHYS RES, V69, P1995 MOSEBACH R, 1957, J GEOL, V65, P347 NAUMOV GB, 1971, HDB THERMODYNAMIC DA, P226 OKAMOTO G, 1957, GEOCHIM COSMOCHIM AC, V12, P123 PANG ZH, 1998, GEOCHIM COSMOCHIM AC, V62, P1083 POWELL R, 1985, J METAMORPH GEOL, V3, P327 RAGNARSDOTTIR KV, 1983, GEOCHIM COSMOCHIM AC, V47, P941 REED M, 1984, GEOCHIM COSMOCHIM AC, V48, P1479 RICHET P, 1982, GEOCHIM COSMOCHIM AC, V46, P2639 RIMSTIDT JD, 1980, GEOCHIM COSMOCHIM AC, V44, P1683 ROBIE RA, 1978, US GEOL SURV B, V1452, P1 ROLLER PS, 1940, J AM CHEM SOC, V62, P123 RYZHENKO BN, 1967, GEOCHEM INT, V4, P99 SAXENA S, 1992, ADV PHYSICAL GEOCHEM, P79 SEWARD TM, 1974, GEOCHIM COSMOCHIM AC, V38, P1651 SIGVALDASON GE, 1966, B VOLCANOL, V29, P589 SMITH FG, 1958, QUARTZ CANADA MINERA, V5, P210 SMITH JM, 1975, INTRO CHEM THERMODYN, P632 SOMMERFELD RA, 1967, J GEOPHYS RES, V72, P4253 STUMM W, 1981, AQUATIC CHEM INTRO E SWAMY V, 1994, J GEOPHYS RES-SOLID, V99, P11787 TOLE MP, 1993, GEOTHERMICS, V22, P17 TRUESDELL AH, 1977, J RES US GEOL SURV, V5, P49 TRUESDELL AH, 1979, 2 S CERR PREIT GEOTH, P224 VANLIER JA, 1960, J PHYS CHEM-US, V64, P1675 VERMA MP, 1989, P 6 INT S WAT ROCK I, P723 VERMA MP, 1997, GEOFISICA INT, V36, P181 VERMA SP, 1997, J VOLCANOL GEOTH RES, V79, P9 VOLOSOV AG, 1972, GEOCHEM INT, V9, P362 VONDAMM KL, 1991, AM J SCI, V291, P977 WALTHER JV, 1977, AM J SCI, V277, P1315 WALTHER JV, 1983, AM MINERAL, V68, P731 WALTHER JV, 1993, GEOCHIM COSMOCHIM AC, V57, P2431 WASSERBURG GJ, 1958, AM J SCI, V256, P438 WASSERBURG GJ, 1958, J GEOL, V66, P559 WEILL DF, 1964, GEOCHIM COSMOCHIM AC, V28, P1243 WHITE DE, 1956, GEOCHIM COSMOCHIM AC, V10, P27 WOOD JA, 1958, AM J SCI, V256, P40 WOODLAND AB, 1987, GEOCHIM COSMOCHIM AC, V51, P365 WYART J, 1955, COMPT REND HEBDOMAD, V240, P1905 XIE Z, 1997, GEOCHIM COSMOCHIM AC, V57, P1947 XIE ZX, 1993, AM J SCI, V293, P235 NR 93 TC 4 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0375-6505 J9 GEOTHERMICS JI Geothermics PD JUN PY 2000 VL 29 IS 3 BP 323 EP 346 PG 24 SC Energy & Fuels; Geosciences, Multidisciplinary GA 308ZP UT ISI:000086743000001 ER PT J AU Palmeros, B Wild, J Szybalski, W Le Borgne, S Hernandez-Chavez, G Gosset, G Valle, F Bolivar, F TI Family of removable cassettes designed to obtain antibiotic-resistance-free genomic modifications of Escherichia coli and other bacteria SO GENE LA English DT Article DE Cre; loxP; recombinant DNA tools; site-specific recombination; unmarked strains ID SITE-SPECIFIC RECOMBINATION; CHROMOSOMAL INTEGRATION; RESOLUTION SYSTEM; PLASMID PSC101; SUICIDE VECTOR; CONSTRUCTION; GENE; EXCISION; CLONING; LOXP AB Modifications of microbial genomes often require the use of the antibiotic-resistance CAnb(R))-encoding genes and other easily selectable markers. We have developed a set of such selectable markers (Cm-R, Km(R) and Gm(R)), which could easily be inserted into the genome and subsequently removed by using the Cre/loxP site-specific recombination system of bacteriophage pi. In this manner the same marker could be used more than once in the same background, while the resulting strain could or would remain Anb(R) marker-free. Three plasmids were constructed, each containing a cassette consisting of the Cm-R, Km(,)(R) or Gm(R) gene flanked by two parallel loxP sites and two polylinkers (MCS). To test insertion and excision, cassettes were inserted into the lacZ or galE genes carried on an ori gamma/pir-dependent suicide plasmid, which contained a dominant Sm-R gene. The cassettes were crossed into the E. coli genome by homologous recombination (allelic exchange), in a manner analogous to that described by Posfai et al. [Nucl. Acids Res. 22 (1994) 2392-2398], selecting for the Cm-R, Km(R), or Gm(R), for the LacZ(-) or GalE(-) and for the Sm-S phenotypes (the latter to assure allelic exchange rather than insertion of the entire plasmid). When required, after selecting the strain with the desired modification, the CmR, KmR, or GmR marker was excised by supplying the Cre function. Cre was provided by the thermosensitive plasmid pJW168, which was transformed into the Anb(R) host at 30 degrees C, and was subsequently eliminated at 42 degrees C. Thus the Anb(R) marker was removed, whereas the lacZ or galE gene remained interrupted by the retained loxP site. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Univ Nacl Autonoma Mexico, Inst Biotechnol, Dept Mol Microbiol, Cuernavaca 62210, Morelos, Mexico. Univ Wisconsin, Sch Med, Mcardle Lab Canc Res, Madison, WI 53706 USA. Genencor Int Inc, Palo Alto, CA 94304 USA. RP Bolivar, F, Univ Nacl Autonoma Mexico, Inst Biotechnol, Dept Mol Microbiol, Cuernavaca 62210, Morelos, Mexico. CR ALEXEYEV MF, 1995, GENE, V160, P63 ARMSTRONG KA, 1984, J MOL BIOL, V175, P331 BOLIVAR F, 1977, GENE, V2, P95 BUCHHOLZ F, 1996, NUCLEIC ACIDS RES, V24, P3118 CASADABAN MJ, 1980, J BACTERIOL, V143, P971 CHEREPANOV PP, 1995, GENE, V158, P9 COLWELL RR, 1991, CURR OPIN BIOTECH, V2, P470 CRAIG NL, 1988, ANNU REV GENET, V22, P77 DELORENZO V, 1992, CURR OPIN BIOTECH, V3, P227 FUQUA WC, 1992, BIOTECHNIQUES, V12, P223 HASAN N, 1994, GENE, V150, P51 HASHIMOTOGOTOH T, 1977, J BACTERIOL, V131, P405 HIGGINS NP, 1996, J BACTERIOL, V178, P2825 HOANG TT, 1998, GENE, V212, P77 HOESS RH, 1986, NUCLEIC ACIDS RES, V14, P2287 JENSEN KF, 1993, J BACTERIOL, V175, P3401 KANIGA K, 1991, GENE, V109, P137 KILBY NJ, 1993, TRENDS GENET, V9, P413 KORNBERG A, 1992, DNA REPLICATION, P655 KRISTENSEN CS, 1995, J BACTERIOL, V177, P52 LEBORGNE S, 1998, GENE, V223, P213 MIKKELSEN TR, 1996, NATURE, V380, P31 MILLER VL, 1988, J BACTERIOL, V170, P2575 PEREDELCHUK MY, 1997, GENE, V187, P231 POSFAI G, 1994, NUCLEIC ACIDS RES, V22, P2392 SAMBROOK J, 1989, MOL CLONING LAB MANU SAUER B, 1994, BIOTECHNIQUES, V16, P1086 SAUER B, 1994, CURR OPIN BIOTECH, V5, P521 SNAITH MR, 1995, GENE, V166, P173 STERNBERG N, 1981, J MOL BIOL, V150, P467 UEKI T, 1996, GENE, V183, P153 WILD J, 1998, GENE, V223, P55 WILSON K, 1987, CURRENT PROTOCOLS MO NR 33 TC 21 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0378-1119 J9 GENE JI Gene PD APR 18 PY 2000 VL 247 IS 1-2 BP 255 EP 264 PG 10 SC Genetics & Heredity GA 308BR UT ISI:000086689100026 ER PT J AU Alvarez, G Palacios, MJ Flores, JJ TI A test method to evaluate the thermal performance of window glazings SO APPLIED THERMAL ENGINEERING LA English DT Article DE buildings; glazing; thermal performance; comparative test data AB An apparatus and a methodology to evaluate the thermal performance of window glazing are presented. Single glazings commercially available in Mexico are currently tested. During the test sequence, the glass samples are mounted in a specially designed calorimeter apparatus. The test is conducted in controlled laboratory conditions at the National Centre for Research and Technology Development in Mexico using a solar simulator test lamp. The calorimeter apparatus and the solar simulator test lamp were characterised and the overall heat loss coefficient U-c measured was of 1.7 +/- 0.1 W/m(2)degrees C. Overall heat transfer and shading coefficients are derived from the experimental results. The test method described allows the testing of practically any kind of glazing array. Glasses under investigation were of the reflective, absorbing coloured and common ones. This test method can be adequate to evaluate film coating glazing or multiple solar control coating glazing. Also, it can be of assistance to researchers, glass manufacturers and building designers in the development of rating and comparing of glazing options. (C) 2000 Elsevier Science Ltd. All rights reserved. C1 Natl Ctr Res & Tehcnol Dev, DGIT, SEP, Cuernavaca 62050, Morelos, Mexico. RP Alvarez, G, Natl Ctr Res & Tehcnol Dev, DGIT, SEP, AP 5-164, Cuernavaca 62050, Morelos, Mexico. CR 1980, 0406 ASTM 1996, VITRO VIDRIO PLANO M *ASHRAE, 1977, ASHRAE HDB ARASTEH DK, 1989, ASHRAE T 2, V95, P755 DUBROUS FM, 1985, INT 85 ISES C MONTR, P533 KISS LI, 1975, ENERGY CONSERVATION, V2, P883 MOORE F, 1982, PASSIVE SOLAR J, V1, P91 NR 7 TC 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 1359-4311 J9 APPL THERM ENG JI Appl. Therm. Eng. PD JUN PY 2000 VL 20 IS 9 BP 803 EP 812 PG 10 SC Thermodynamics; Energy & Fuels; Engineering, Mechanical; Mechanics GA 306XU UT ISI:000086624600003 ER PT J AU Sebastian, PJ Rodriguez, FJ TI Development of MoxRuySez(CO)(n) electrocatalysts by screen printing and sintering for fuel cell applications SO SURFACE ENGINEERING LA English DT Article ID METAL-CLUSTERS; CATALYSIS; REDUCTION; CHEMISTRY; PLATINUM; OSMIUM; OXYGEN AB Electrocatalysts based on molybdenum, ruthenium, and selenium were prepared by screen printing Ru-3(CO)(12) + Se and Ru-3(CO)(12) + Ma(CO)(6) + Se mixtures and subsequent sintering at 250 degrees C in air or Se atmosphere in a tubular furnace. The catalysts were characterised using techniques such as XRD, SEM, TEM voltammetry, and polarisation (current-potential) measurements. The results indicate that screen printed RuxSey(CO)(n) and MoxRuySez(CO)(n) are near amorphous in nature and possess appreciable catalytic activity for the oxygen reduction reaction in a polymer electrolyte (Nafion membrane) fuel cell. The electrocatalytic activity seems to diminish with selenium incorporation in the lattice of the carbonyl clusters formed during synthesis. C1 UNAM, Energy Res Ctr, Temixco 62580, Morelos, Mexico. RP Sebastian, PJ, UNAM, Energy Res Ctr, Temixco 62580, Morelos, Mexico. CR ADAMS RD, 1985, POLYHEDRON, V4, P2003 BOND AM, 1997, COORDIN CHEM REV, V166, P161 DEEMING AJ, 1995, COMPREHENSIVE ORGANO, V7, P684 FOURNIER J, 1997, J ELECTROCHEM SOC, V144, P145 GATES BC, 1995, CHEM REV, V95, P511 LIN Z, 1997, STRUCTURAL ELECT PAR MUETTERTIES EL, 1983, ANGEW CHEM INT EDIT, V22, P135 POIRIER JA, 1994, J ELECTROCHEM SOC, V141, P425 RIAZ U, 1994, J AM CHEM SOC, V116, P4357 RODRIGUEZ FJ, 1996, P INT MAT RES C CANC, P25 RODRIGUEZ FJ, 1998, INT J HYDROGEN ENERG, V23, P1031 ROMERO T, IN PRESS J NEW MAT E ROMERO T, 1996, THESIS CINVESTAV IPN ROMERO T, 1998, INT J HYDROGEN ENERG, V23, P1041 ROTHSTEIN J, 1996, INT J HYDROGEN ENERG, V21, P137 SAVADOGO O, 1994, J ELECTROCHEM SOC, V141, P292 SAVADOGO O, 1995, P 1 INT S NEW MAT FU, P544 SEBASTIAN PJ, IN PRESS IND J HYDRO SEBASTIAN PJ, 1994, SOL ENERG MAT SOL C, V32, P159 SEBASTIAN PJ, 1996, SOL ENERG MAT SOL C, V44, P1 SHI CN, 1995, PURE APPL CHEM, V67, P319 SHRIVER DF, 1990, CHEM METAL CLUSTER C SOLORZA O, 1994, ELECTROCHIM ACTA, V39, P1547 SOMORJAI GA, 1995, SURF SCI, V335, P10 TAVAGNACCO C, 1998, J ELECTROANAL CHEM, V448, P41 WONG WT, 1998, J CHEM SOC DALT 0421, P1253 YE SY, 1997, J ELECTROCHEM SOC, V144, P90 NR 27 TC 1 PU INST MATERIALS PI LONDON PA 1 CARLTON HOUSE TERRACE, LONDON SW1Y 5DB, ENGLAND SN 0267-0844 J9 SURFACE ENG JI Surf. Eng. PY 2000 VL 16 IS 1 BP 43 EP 46 PG 4 SC Materials Science, Coatings & Films GA 305KL UT ISI:000086538900006 ER PT J AU Jimenez-Gonzalez, AE Cambray, JG TI Deposition of NiOx thin films by sol-gel technique SO SURFACE ENGINEERING LA English DT Article ID NICKEL-OXIDE AB High quality NiOx thin films have been prepared by the sol-gel technique following alternative routes to the classic metal alkoxide route. Using nickel (II) diacetate as precursor reagent, a nickel complex was deposited on glass substrates. The nickel complex transforms to NiOx after a heat treatment in air above 250 degrees C. X-ray diffraction analysis confirmed the crystalline --> amorphous phase transition during annealing of the films. The NiOx thin films prepared in this way are very homogeneous and mostly amorphous. Compared with intrinsic single crystals, they have relatively high electrical conductivity and low optical transmittance in the visible and infrared regions. An optical band gap narrowing from 3.90 to 380 eV with increasing film thickness tvas measured in the films. Sol-gel prepared NiOx thin films are well suited for use as electrochromic films. C1 UNAM, Energy Res Ctr, Temixco 62580, Morelos, Mexico. RP Jimenez-Gonzalez, AE, UNAM, Energy Res Ctr, Temixco 62580, Morelos, Mexico. CR ADLER D, 1992, PHYS REV B, V45, P3112 ATKINSON A, 1982, CORROS SCI, V22, P347 CARPENTER MK, 1987, SOL ENERG MATER, V16, P333 CHOPRA KL, 1983, THIN SOLID FILMS, V102, P1 GARCIA VM, 1997, SEMICOND SCI TECH, V12, P645 JIMENEZGONZALEZ AE, IN PRESS J CRYST GRO JIMENEZGONZALEZ AE, 1998, SOL ENERG MAT SOL C, V52, P345 KEEM JE, 1978, PHILOS MAG B, V37, P537 LAMPERT CM, 1989, SPIE, V1149, P56 LUNKENHEIMER P, 1991, PHYS REV B, V44, P5927 LYNAM NR, 1987, P SOC PHOTO-OPT INS, V823, P130 MIKI T, 1997, P SPIE, V2531 SATO H, 1993, THIN SOLID FILMS, V236, P27 SMITH RA, 1978, SEMICONDUCTORS+, P442 TERAKURA K, 1984, PHYS REV LETT, V52, P1830 TORRESI RM, 1993, THIN SOLID FILMS, V229, P180 YU PC, 1987, SOL ENERG MATER, V16, P1 NR 17 TC 5 PU INST MATERIALS PI LONDON PA 1 CARLTON HOUSE TERRACE, LONDON SW1Y 5DB, ENGLAND SN 0267-0844 J9 SURFACE ENG JI Surf. Eng. PY 2000 VL 16 IS 1 BP 73 EP 76 PG 4 SC Materials Science, Coatings & Films GA 305KL UT ISI:000086538900013 ER PT J AU Gonzalez-Rodriguez, JG Bahena-Martinez, G Salinas-Bravo, VM TI Effect of heat treatment on the stress corrosion cracking behaviour of 403 stainless steel in NaCl at 95 degrees C SO MATERIALS LETTERS LA English DT Article DE heat treatment; stress corrosion cracking; stainless steel AB Slow strain rate tests have been used to evaluate the effect of heat treatment on the susceptibility to stress corrosion cracking (SCC) of type AISI 403 martensitic stainless steel in 20% NaCl at 95 degrees C. Heat-treated specimens included water quenched, quenched and tempered at 200 degrees C, 400 degrees C and 600 degrees C, respectively, and annealed at 850 degrees C. When tested in an inert environment, the lowest elongation to failure and percentage reduction in area was shown by the quenched specimen, and the highest by the annealed specimen, and between these two specimens, there were the specimens tempered at 200 degrees C, 400 degrees C and 600 degrees C, respectively. When tested in 20% NaCl (wt.%), pH 7, without exception, all the specimens were embrittled by the environment, showing, at least, 50% of the elongation exhibited in the inert environment, indicating a cracking-induced environmentally. The fracture morphology presented completely intergranular cracks along the prior austenite for the quenched specimen to completely transgranular cracking for the annealed specimen. The percentage of intergranular cracks decreased as the tempering temperature increased from 200 degrees C to 600 degrees C. The fracture mechanism is thought to occur in terms of a hydrogen embrittlement. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Univ Autonoma Estado Morelos, Fac Ciencias Quim & Ingn, Cuernavaca 62215, Morelos, Mexico. Inst Invest Elect, Dept Proc Term Interior Internado Palmira, Cuernavaca 62001, Morelos, Mexico. RP Gonzalez-Rodriguez, JG, Univ Autonoma Estado Morelos, Fac Ciencias Quim & Ingn, Av Univ 1001,Col Chamilpa, Cuernavaca 62215, Morelos, Mexico. CR DESANTAMARIA MS, 1989, CORROS SCI, V29, P69 DOIG P, 1982, MET T A, V13, P913 ELSAYED HA, 1981, SURF TECHNOL, V16, P245 ELSAYED HA, 1986, PREV CONTROL, V12, P142 GOUDA VK, 1983, SURF TECHNOL, V18, P327 KNUTSEN RD, 1991, CORROSION, V47, P359 LINDINGER RJ, 1981, CORROSION 81 MAIER I, 1980, CORROSION, V36, P60 POURBAIX M, 1966, ATLAS ELECTROCHEMICA SHALVOY RS, 1981, CORROSION 81 SPACHN H, 1988, ENV INDUCED CRACKING, P449 VISWANATHAN R, 1991, LIFE PREDICTION CORR WILDE BE, 1971, CORROSION, V27, P326 NR 13 TC 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0167-577X J9 MATER LETT JI Mater. Lett. PD APR PY 2000 VL 43 IS 4 BP 208 EP 214 PG 7 SC Materials Science, Multidisciplinary; Physics, Applied GA 305JE UT ISI:000086535700010 ER PT J AU Diaz-Perez, JC Bautista, S Villanueva, R TI Quality changes in sapote mamey fruit during ripening and storage SO POSTHARVEST BIOLOGY AND TECHNOLOGY LA English DT Article DE chilling injury; postharvest; quality; ripening; fruit transpiration; Pouteria sapota AB Physical and chemical changes in sapote mamey (Pouteria sapota (Jacq.) H.E. Moore and Steam) fruit during ripening and storage at various temperatures were evaluated. Ripening was associated with flesh softening, an increase in soluble solids content (SSC), and a change in flesh color from yellow or pale pink to a dark pink or red. No changes in fruit skin color or in flesh acidity were observed as ripening progressed. Ripe fruit had 30% or higher SSC, orange or red flesh (hue angle = 52; chroma = 45; L = 60), acidity of 6-8 mM H+, and flesh firmness (compression force) less than or equal to 50 N. Flesh turned brown (L* value declined) in overripe fruit. Fruit held at 27, 25, or 20 degrees C ripened in 3.5, 5 or 7 days after harvest, respectively. Fruit kept at 10 degrees C showed minor changes in color and firmness and a slow rate of SSC increase. Fruit stored at 10 or 15 degrees C and then ripened at 20 degrees C had portions of the flesh with a much higher firmness and poorer development of red color compared to other parts of the fruit. This uneven ripening was probably a result of chilling injury. The number of fruit with injury was higher at 10 degrees C than at 15 degrees C, and increased with storage time. The rates of fruit weight loss relative to the initial fruit weight were 0.58, 0.98 and 1.83% d(-1) at 10, 20 and 27 degrees C, respectively. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Univ Georgia, Coastal Plain Expt Stn, Dept Hort, Tifton, GA 31793 USA. Natl Polytech Inst, Ctr Dev Biot Prod, Dept Biotechnol, Yautepec 62730, Morelos, Mexico. RP Diaz-Perez, JC, Univ Georgia, Coastal Plain Expt Stn, Dept Hort, Tifton Campus, Tifton, GA 31793 USA. CR *CONARFRUT, 1974, 14 CONAFRUT SAG COM *SAS I, 1988, SAS US GUID ALENCASTER NC, 1977, THESIS I POILTECNICO ALMEYDA N, 1976, ARSS156 USDA BALERDI CF, 1996, FC30 U FLOR I FOOD A BAUTISTA S, 1997, MEXICO HORTIC MEX, V5, P168 BURTON WG, 1982, POSTHARVEST PHYSL FO, P43 CAMPBELL CA, 1994, HORTSCIENCE, V29, P975 CLAYPOOL LL, 1942, P AM SOC HORTIC SCI, V40, P177 FRANCIS FJ, 1980, HORTSCIENCE, V15, P58 GEORGE JB, 1985, ACTA HORTIC, V158, P439 GROSS J, 1979, GARTENBAUWISSENSCHAF, V44, P27 KADER AA, 1992, U CALIFORNIA PUBLICA, V3311, P15 LAKSHMINARAYANA S, 1980, TROPICAL SUBTROPICAL LEWIS CE, 1978, J SCI FOOD AGR, V29, P857 MARTINEZ M, 1959, PLANTAS UTILES FLORA, P393 MORALESVAZQUEZ MD, 1983, THESIS COMISION NACL PAULL RE, 1990, CHILLING INJURY HORT, P17 POPENOE W, 1948, MANUAL TROPICAL SUBT, P340 ROY SK, 1997, POSTHARVEST PHYSL ST, P387 SNOWDON AL, 1990, COLOR ATLAS POST HAR, V1 NR 21 TC 9 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0925-5214 J9 POSTHARVEST BIOL TECHNOL JI Postharvest Biol. Technol. PD JAN PY 2000 VL 18 IS 1 BP 67 EP 73 PG 7 SC Agronomy; Food Science & Technology; Horticulture GA 297YJ UT ISI:000086110400009 ER PT J AU Parra, RS George, PJ Sanchez, GG Gonzalez, AEJ Banos, L Nair, PK TI Optical and electrical properties of Pbs plus In thin films subjected to thermal processing SO JOURNAL OF PHYSICS AND CHEMISTRY OF SOLIDS LA English DT Article DE indium; thin films; optical properties; electrical properties ID N-TYPE; CDS AB Indium thin film (similar to 20 nm) deposited on intrinsic lead sulfide films leads to the formation of an n-type composite layer when annealed in nitrogen atmosphere at 350-400 degrees C, The formation of metallic lead and indium oxide is observed in the X-ray diffraction patterns of the films. The dark conductivity of the PbS + In films after nitrogen annealing at 400 degrees C attains a value of 500 Omega(-1) cm(-1), which is higher by five orders of magnitude compared with as-prepared PbS films. Modifications in the optical and electrical properties of PbS + In films after annealing are attributed to the presence of metallic lead and indium oxide in the films. (C) 2000 Elsevier Science Ltd. All rights reserved. C1 Univ Nacl Autonoma Mexico, Ctr Invest Energia, Temixco 62580, Morelos, Mexico. Kurukshetra Univ, Dept Elect Sci, Kurukshetra 132119, Haryana, India. RP Parra, RS, Univ Nacl Autonoma Mexico, Ctr Invest Energia, Temixco 62580, Morelos, Mexico. CR CHATTERJEE S, 1992, INT C THERM ARL US O, P7 CHAUDHURI TK, 1981, THIN SOLID FILMS, V83, P169 CHAUDHURI TK, 1992, INT C THERM ARL US O, P7 CHAUDHURI TK, 1992, INT J ENERG RES, V16, P481 CULLITY BD, 1978, ELEMENTS XRAY DIFFRA, V2 GARCIA VM, 1996, J ELECTROCHEM SOC, V143, P2892 GEORGE PJ, 1995, APPL PHYS LETT, V66, P3624 GEORGE PJ, 1995, J CRYST GROWTH, V4055, P1 KOVALEV AN, 1988, THIN SOLID FILMS, V161, P281 MADELUNG O, 1992, SEMICONDUCTORS OTHER NAIR PK, 1989, SEMICOND SCI TECH, V4, P807 NAIR PK, 1990, J PHYS D APPL PHYS, V23, P150 NAIR PK, 1998, SOL ENERG MAT SOL C, V52, P313 PARRA RS, 1996, J SOLID STATE CHEM, V123, P296 PARRA RS, 1998, J SOLID STATE CHEM, V138, P290 REDDY GB, 1981, SOL ENERG MATER, V5, P187 RINCON ME, 1996, J PHYS CHEM SOLIDS, V57, P1947 SHALIMOVA KV, 1975, FISICA SEMICONDUCTOR, P264 SHARMA NC, 1979, THIN SOLID FILMS, V62, P97 VOGEL R, 1994, J PHYS CHEM-US, V98, P3183 ZINGARO RA, 1964, J ELECTROCHEM SOC, V111, P42 NR 21 TC 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0022-3697 J9 J PHYS CHEM SOLIDS JI J. Phys. Chem. Solids PD MAY PY 2000 VL 61 IS 5 BP 659 EP 668 PG 10 SC Chemistry, Multidisciplinary; Physics, Condensed Matter GA 293NL UT ISI:000085859000002 ER PT J AU Cruz-Vera, LR Toledo, I Hernandez-Sanchez, J Guarneros, G TI Molecular basis for the temperature sensitivity of Escherichia coli pth(Ts) SO JOURNAL OF BACTERIOLOGY LA English DT Article ID TRANSFER-RNA HYDROLASE; PEPTIDYL-TRANSFER-RNA; PROTEIN-SYNTHESIS; METABOLIC ROLE; MUTANT; LAMBDA; DNAJ; BACTERIOPHAGE; ACCUMULATION; DEGRADATION AB The gene pth, encoding peptidyl-tRNA hydrolase (Pth), is essential for protein synthesis and viability of Escherichia coli. Two pth mutants have been studied in depth: a pth(Ts) mutant isolated as temperature sensitive and a pth(rap) mutant selected as nonpermissive for bacteriophage lambda vegetative growth. Here we show that each mutant protein is defective in a different way. The Pth(Ts) protein was very unstable in vivo, both at 43 degrees C and at permissive temperatures, but its specific activity was comparable to that of the wild-type enzyme, Pth(wt). Conversely, the mutant Pth(rap) protein had the same stability as Pth(wt), but its specific activity was low. The thermosensitivity of the pth(Ts) mutant, presumably, ensues after Pth(Ts) protein levels are reduced at 43 degrees C. Conditions that increased the cellular Pth(Ts) concentration, a rise in gene copy number or diminished protein degradation, allowed cell growth at a nonpermissive temperature. Antibiotic-mediated inhibition of mRNA and protein synthesis, but not of peptidyl-tRNA drop-off, reduced pth(Ts) cell viability even at a permissive temperature. Based on these results, we suggest that Pth(Ts) protein, being unstable in vivo, supports cell viability only if its concentration is maintained above a threshold that allows general protein synthesis. C1 Inst Politecn Nacl, Ctr Invest & Estudios Avanzados, Dept Genet & Mol Biol, Mexico City 07000, DF, Mexico. UNAM, Ctr Invest Fijac Nitrogeno, Dept Mol Genet, Cuernavaca, Morelos, Mexico. RP Guarneros, G, Inst Politecn Nacl, Ctr Invest & Estudios Avanzados, Dept Genet & Mol Biol, Apartado Postal 14-740, Mexico City 07000, DF, Mexico. 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Bacteriol. PD MAR PY 2000 VL 182 IS 6 BP 1523 EP 1528 PG 6 SC Microbiology GA 288VK UT ISI:000085585000008 ER PT J AU Santoyo, E Garcia, A Espinosa, G Hernandez, I Santoyo, S TI STATIC_TEMP: a useful computer code for calculating static formation temperatures in geothermal wells SO COMPUTERS & GEOSCIENCES LA English DT Article DE true formation temperature; bottomhole temperature; drilling; cementing; shut-in ID BOREHOLE MEASUREMENTS; FLUID INCLUSION; KAKKONDA; FIELD; JAPAN; 500-DEGREES-C; CIRCULATION; INVERSION; BOTTOM; FLOW AB The development and application of the computer code STATIC_TEMP, a useful tool for calculating static formation temperatures from actual bottomhole temperature data logged in geothermal wells is described. STATIC_TEMP is based on five analytical methods which are the most frequently used in the geothermal industry. Conductive and convective heat flow models (radial, spherical/radial and cylindrical/radial) were selected. The computer code is a useful tool that can be reliable used in situ to determine static formation temperatures before or during the completion stages of geothermal wells (drilling and cementing). Shut-in time and bottomhole temperature measurements logged during well completion activities are required as input data. Output results can include up to seven computations of the static formation temperature by each wellbore temperature data set analysed. STATIC_TEMP was written in Fortran-77 Microsoft language for MS-DOS environment using structured programming techniques. It runs on most IBM compatible personal computers. The source code and its computational architecture as well as the input and output files are described in detail. Validation and application examples on the use of this computer code with wellbore temperature data (obtained from specialised literature) and with actual bottomhole temperature data (taken from completion operations of some geothermal wells) are also presented. (C) 2000 Elsevier Science Ltd. All rights reserved. C1 Univ Nacl Autonoma Mexico, Ctr Invest Energia, Temixco 65280, Morelos, Mexico. Inst Invest Elect, Unidad Geotermia, Temixco 62490, Morelos, Mexico. Univ Autonoma Metropolitana, Vicentina 09340, Mexico. ITESM, Ctr Sistemas Manufactura, Monterrey 64849, NL, Mexico. RP Santoyo, E, Univ Nacl Autonoma Mexico, Ctr Invest Energia, Apartado Postal 34, Temixco 65280, Morelos, Mexico. 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Geosci. PD MAR PY 2000 VL 26 IS 2 BP 201 EP 217 PG 17 SC Computer Science, Interdisciplinary Applications; Geosciences, Multidisciplinary GA 288BZ UT ISI:000085543100006 ER PT J AU Rodriguez, FJ Sebastian, PJ TI Chemically synthesized RuxSey-(CO)n electrocatalyst for application in fuel cell electrode SO JOURNAL OF NEW MATERIALS FOR ELECTROCHEMICAL SYSTEMS LA English DT Article DE Ru-3(CO)(12); Se; RuxSey-(CO)n; electrocatalyst; fuel cell; oxygen reduction ID MOLECULAR-OXYGEN REDUCTION; METAL-CLUSTERS; CATALYSIS; CHEMISTRY; OSMIUM AB RuxSey-(CO)n electrocatalyst was prepared by a chemical pyrolysis of Ru-3(CO)(12) + Se mixture at 140 degrees C and sintering in Se atmosphere in a tubular at 250 degrees C. The catalyst was characterized using techniques such as XRD (x-ray diffraction) SEM (scanning electron microscopy), TEM (transmission electron microscopy), voluntary and polarization (current-potential) measurements. The results indicated that chemically synthesized RuxSey-(CO)(n), is near amorphous in nature and possesses appreciable catalytic activity for oxygen reduction reaction in a polymer electrolyte (nafion(R) membrane) fuel cell. The electrocatalytic activity seems to diminish with Se incorporation in the lattice of the Ru-carbonyl clusters formed during synthesis. C1 UNAM, CIE, Solar Mat Dept, Solar H2 Fuel Cell Grp, Temixco 62580, Morelos, Mexico. RP Sebastian, PJ, UNAM, CIE, Solar Mat Dept, Solar H2 Fuel Cell Grp, Temixco 62580, Morelos, Mexico. CR ADAMS RD, 1985, POLYHEDRON, V4, P2003 ANSON FC, 1997, ACCOUNTS CHEM RES, V30, P437 BOND AM, 1997, COORDIN CHEM REV, V166, P161 DEEMING AJ, 1995, COMPREHENSIVE ORGANO, V7, P684 GATES BC, 1995, CHEM REV, V95, P511 LIN Z, 1997, STRUCTURAL ELECT PAR MUETTERTIES EL, 1983, ANGEW CHEM INT EDIT, V22, P135 RIAZ U, 1994, J AM CHEM SOC, V116, P4357 RODRIGUEZ FJ, 1998, INT J HYDROGEN ENERG, V23, P1031 ROMERO T, 1998, INT J HYDROGEN ENERG, V23, P1041 SAVADOGO O, 1997, P 2 INT S NEW MAT FU SHI CN, 1995, PURE APPL CHEM, V67, P319 SHRIVER DF, 1990, CHEM METAL CLUSTER C SOLORZA O, 1996, 11 C IB EL 9 ENC VEN SOLORZAFERIA O, 1994, ELECTROCHIM ACTA, V39, P1647 SOLORZAFERIA O, 1997, THIN SOLID FILMS, V311, P164 SOMORJAI GA, 1995, SURF SCI, V335, P10 TAVAGNACCO C, 1998, J ELECTROANAL CHEM, V448, P41 WONG WT, 1998, J CHEM SOC DALT 0421, P1253 NR 19 TC 7 PU ECOLE POLYTECHNIQUE MONTREAL PI MONTREAL PA C P 6079, SUCC CENTRE-VILLE, MONTREAL, QC H3C 3A7, CANADA SN 1480-2422 J9 J NEW MATER ELECTROCHEM SYST JI J. New Mat.Electrochem. Syst. PD APR PY 1999 VL 2 IS 2 BP 107 EP 110 PG 4 SC Electrochemistry; Materials Science, Multidisciplinary GA 283NE UT ISI:000085281000006 ER PT J AU Romero, T Solorza, O Rivera, R Sebastian, PJ TI Synthesis and characterization of Ru-x(CO)(n) electrocatalyst for oxygen reduction reaction in a PEM (Proton Exchange Membrane) fuel cell SO JOURNAL OF NEW MATERIALS FOR ELECTROCHEMICAL SYSTEMS LA English DT Article DE Ru-x(CO)(n); oxygen reduction; Tafel slope; fuel cell; polymer electrolyte ID CHALCOGENIDE AB A chemical synthesis process was used for preparing Ru-x(CO)(n) electrocatalyst in 1,2-dichlorobenzene medium at 180 degrees C. The catalyst was characterized using techniques such as XRD (x-ray diffraction), SEM (scanning electron microscopy), rotating disc electrode (RDE) stationary and polarization (current-potential) measurements. The kinetic parameters such as Tafel slope, exchange current density, change transfer coefficient and over potential at i=1 mAcm(-2), were determined from electrochemical studies. The results indicated that chemically synthesized Ru-x(CO)(n) possesses appreciable catalytic activity for oxygen reduction reaction in a polymer electrolyte (Nafion(R) membrane) fuel cell. C1 UNAM, CIE, Temixco 62580, Morelos, Mexico. Inst Politecn Nacl, Ctr Invest & Estudios Avanzados, Dept Quim, Mexico City 07000, DF, Mexico. RP Sebastian, PJ, UNAM, CIE, Temixco 62580, Morelos, Mexico. CR ANSON FC, 1997, ACCOUNTS CHEM RES, V30, P437 BARD AJ, 1980, ELECTROCHEMICAL METH RODRIGUEZ FJ, 1998, INT J HYDROGEN ENERG, V23, P1031 ROMERO T, 1998, INT J HYDROGEN ENERG, V23, P1041 SAVADOGO O, 1997, P 2 INT S NEW MAT FU SOLORZAFERIA O, 1994, ELECTROCHIM ACTA, V39, P1647 SOLORZAFERIA O, 1997, THIN SOLID FILMS, V311, P164 NR 7 TC 16 PU ECOLE POLYTECHNIQUE MONTREAL PI MONTREAL PA C P 6079, SUCC CENTRE-VILLE, MONTREAL, QC H3C 3A7, CANADA SN 1480-2422 J9 J NEW MATER ELECTROCHEM SYST JI J. New Mat.Electrochem. Syst. PD APR PY 1999 VL 2 IS 2 BP 111 EP 114 PG 4 SC Electrochemistry; Materials Science, Multidisciplinary GA 283NE UT ISI:000085281000007 ER PT J AU Sierra-Espinosa, FZ Bates, CJ O'Doherty, T TI Turbulent flow in a 90 degrees pipe junction Part 1. Decay of fluctuations upstream the flow bifurcation SO COMPUTERS & FLUIDS LA English DT Article DE turbulence modelling; turbulence fluctuations; laser Doppler; separation AB A water flow at the inlet and downstream, before the bifurcation, of a 90 degrees tee pipe junction has been investigated. The tee junction bifurcates the flow of Reynolds number 1.26 x 10(5), based on the inlet bulk velocity and a pipe diameter of 50 mm, into a branch exit-to-inlet mass flow ratio Q(1)/Q(3) = 0.5. Predictions and measurements of the streamwise component of velocity conducted with laser Doppler anemometry compared well in general. However, the fact that the flow bifurcates downstream to 90 degrees causes the converged solution from three models for turbulence k-epsilon, renormalization group theory (RNG) and Reynolds stress model (RSM) to differ from each other. At the inlet the second moment normalised with respect to both the outer and inner scales of velocity, u(x) and u*, respectively, indicate non-symmetry, whereas the profiles of the streamwise component of velocity indicate symmetry. Downstream, close to the onset of flow bifurcation at the chamfer of the tee junction, the measured turbulence fluctuations damp down drastically within the inner and outer layers. The RSM model performs the best in reproducing the experimental data. Decay of turbulence has been observed also in U bends where measurements show typical behaviour of separation. In a separate paper the characteristics of the how at the branch exit of the tee are analysed. (C) 2000 Elsevier Science Ltd. All rights reserved. C1 Univ Wales, Sch Engn, Div Mech Engn & Energy Studies, Cardiff CF2 3TA, S Glam, Wales. RP Sierra-Espinosa, FZ, UNAM, Ctr Invest Energia, AP 34, Temixco 62580, Morelos, Mexico. CR ABERNETHY RB, 1985, J FLUID ENG-T ASME, V107, P161 ANWER M, 1990, J FLUID MECH, V210, P415 CHEN H, 1992, J HYDRODYNAMICS, V4, P50 DURBIN PA, 1993, J FLUID MECH, V249, P465 DURST F, 1995, J FLUID MECH, V295, P305 FU H, 1991, ASME FLUIDS ENG C, V1, P33 KARINO T, 1979, BIORHEOLOGY, V16, P231 LAUNDER BE, 1972, MATH MODELS TURBULEN LE H, 1994, TF58 STANF U DEP MEC LE H, 1997, J FLUID MECH, V330, P349 MONSON DJ, 1990, 901484 AIAA SCHWARZ AC, 1996, J FLUID ENG-T ASME, V118, P787 SIERRAESPINOSA FZ, COMPUTERS FLUIDS, V29, P215 SORIA J, 1996, EXP THERM FLUID SCI, V12, P221 SPENCER EA, 1995, FLOW MEAS INSTRUM, V6, P3 TERRY PA, 1998, B MEXICAN PHYSICAL S, P12 TOWNSEND AA, 1976, STRUCTURE TURBULENT YAKHOT V, 1986, J SCI COMPUT, P1 YANTA WJ, 1973, AIAA 11 AER SC M NR 19 TC 4 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0045-7930 J9 COMPUT FLUIDS JI Comput. Fluids PD FEB PY 2000 VL 29 IS 2 BP 197 EP 213 PG 17 SC Computer Science, Interdisciplinary Applications; Mechanics GA 275NT UT ISI:000084826800004 ER PT J AU Sierra-Espinosa, FZ Bates, CJ O'Doherty, T TI Turbulent flow in a 90 degrees pipe junction Part 2: Reverse flow at the branch exit SO COMPUTERS & FLUIDS LA English DT Article DE predicted turbulent flow; pipe flow; reattachment; backflow; laser Doppler ID MODEL AB The turbulence structure of a water flow in the branch exit of a tee pipe junction has been investigated experimentally and numerically. A mass flow rate branch exit-to-inlet ratio of 50% was used. The Reynolds number based on the inlet bulk mean velocity and the pipe diameter D = 50 mm was 1.26 x 10(5). The numerical solution was conducted employing three models for turbulence, k-epsilon, renormalization group theory (RNG) and Reynolds stress model, using a refined grid to model the smooth chamfer of radius, r = 0.25D as part of the physical tee junction. Within the branch exit the flow has a separation region with recirculation, which extends up to half of the diameter. In this paper the differences noticed between the numerical and experimental results and between the results from each model are discussed. The predicted recirculating flow was attached to the pipe wall up to 2.05D downstream from the separation region, contrary to the 0.65D experimentally observed. In the Vertical direction, the experimental data gave evidence that the near-wall flows are substantially asymmetric. (C) 2000 Elsevier Science Ltd. All rights reserved. C1 Univ Wales, Sch Engn, Div Mech Engn & Energy Studies, Cardiff CF2 3TA, S Glam, Wales. RP Sierra-Espinosa, FZ, UNAM, Ctr Invest Energia, AP 34, Temixco 62580, Morelos, Mexico. CR *BRIT STAND, 1991, 5167 ISO, P17 *FLUENT INC, 1995, FLUENT US GUID VERS ANWER M, 1990, J FLUID MECH, V210, P415 APSLEY DD, 1998, INT J HEAT FLUID FL, V19, P209 CHEN H, 1992, J HYDRODYNAMICS, V4, P50 CHENG KC, 1997, J FLOW VISUALIZATION, V4, P9 COLLINS W, 1990, P EXP M HARN SKEL MU DURBIN PA, 1993, J FLUID MECH, V249, P465 FERZIGER H, 1996, COMPUTATIONAL METHOD FU H, 1991, ASME FLUIDS ENG C, V1, P33 HAGER WH, 1984, P I MECH ENG C-J MEC, V198, P63 HINZE JO, 1959, MCGRAW HILL SERIES M KARINO T, 1979, BIORHEOLOGY, V16, P231 LAUNDER BE, 1972, MATH MODELS TURBULEN MILLER S, 1978, INTERNAL FLOW SYSTEM POP M, 1983, INT C PHYS MOD MULT SIERRAESPINOSA FZ, 2000, COMPUT FLUIDS, V29, P197 SIMPSON RL, 1985, AIAA 23 M REN NEV JA YAKHOT V, 1986, J SCI COMPUT, V1, P3 NR 19 TC 3 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0045-7930 J9 COMPUT FLUIDS JI Comput. Fluids PD FEB PY 2000 VL 29 IS 2 BP 215 EP 233 PG 19 SC Computer Science, Interdisciplinary Applications; Mechanics GA 275NT UT ISI:000084826800005 ER PT J AU Nair, MTS Rodriguez-Lazcano, Y Nair, PK TI Formation of InSb by annealing Sb2S3-In thin films SO JOURNAL OF CRYSTAL GROWTH LA English DT Article DE chemical bath deposition; indium antimonide; antimony sulfide ID N-TYPE; INDIUM; GROWTH AB We report a method to produce large area indium antimonide thin films through a reaction in solid state between thin films of Sb2S3 and In (Sb2S3 + 2 In --> 2 InSb + 3 S up arrow). A thin him of Sb2S3 with typically 0.2. mu m thickness is produced on glass substrate by chemical bath deposition at 10 degrees C using thiosulfatoantimonate(III) complex. Subsequently, a thin film of indium is deposited on the Sb2S3 film by thermal evaporation. Annealing the thin film stack of Sb2S3-In at 300 degrees C under nitrogen atmosphere produces the InSb thin film. The formation of this him is confirmed by X-ray diffraction studies. We discuss the optimization of the individual film thickness in the Sb2S3-In stack to produce a thin film of single-phase InSb or a heterostructure, Sb2S3-InSb. The electrical and optical properties of the films are presented. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Univ Nacl Autonoma Mexico, Dept Solar Energy Mat, Ctr Invest Energia, Temixco 62580, Morelos, Mexico. RP Nair, MTS, Univ Nacl Autonoma Mexico, Dept Solar Energy Mat, Ctr Invest Energia, Temixco 62580, Morelos, Mexico. CR CARPENTER MK, 1994, J MATER RES, V9, P2584 GARCIA VM, 1996, J ELECTROCHEM SOC, V143, P2892 GARCIA VM, 1999, SEMICOND SCI TECH, V14, P366 GEORGE PJ, 1995, APPL PHYS LETT, V66, P3624 NAIR MTS, 1998, J ELECTROCHEM SOC, V145, P2113 NAIR PK, 1997, J MATER RES, V12, P651 NAIR PK, 1998, SOL ENERG MAT SOL C, V52, P313 NEMETH S, 1998, THIN SOLID FILMS, V317, P52 SZE SM, 1981, PHYSICS SEMICONDUCTO, P849 YAMAUCHI S, 1998, THIN SOLID FILMS, V316, P93 NR 10 TC 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-0248 J9 J CRYST GROWTH JI J. Cryst. Growth PD JAN PY 2000 VL 208 IS 1-4 BP 248 EP 252 PG 5 SC Crystallography GA 269PH UT ISI:000084486400036 ER PT J AU Rodriguez, FJ Sebastian, PJ TI MoxSey-(CO)(n) electrocatalyst prepared by screen-printing and sintering SO INTERNATIONAL JOURNAL OF HYDROGEN ENERGY LA English DT Article ID MOLECULAR-OXYGEN REDUCTION; CHALCOGENIDE AB MoxSey-(CO)n electrocatalyst was prepared by screen printing Mo(CO)(6) + Se mixture and subsequent sintering of the same at 250 degrees C in air as well as in Se atmosphere in a tubular furnace. 0978.msi 0978.qrt contents.3t figurelist.txt The catalyst was characterized using techniques such as X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), voltametry and polarization (current-potential) measurements. The results indicated that screen printed MoxSey-(CO)n is near amorphous in nature and possesses appreciable catalytic activity for oxygen reduction reaction in acid electrolyte (H2SO4) The catalytic particles are formed with porous nature and varying compositional zones. The electrocatalytic activity seems to diminish with Se incorporation in the lattice of the Mo-carbonyl clusters formed during sintering. (C) 1999 International Association for Hydrogen Energy. Published by Elsevier Science Ltd. All rights reserved. C1 CIE UNAM, Solar Hydrogen Fuel Cell Grp, Temixco 62580, Morelos, Mexico. RP Rodriguez, FJ, CIE UNAM, Solar Hydrogen Fuel Cell Grp, Temixco 62580, Morelos, Mexico. CR ANSON FC, 1997, ACCOUNTS CHEM RES, V30, P437 RODRIGUEZ FJ, 1998, INT J HYDROGEN ENERG, V23, P1031 ROMERO T, 1998, INT J HYDROGEN ENERG, V23, P1041 ROMERO T, 1999, J NEW MAT ELECT SYST, V2, P111 SAVADOGO O, 1997, NEW MAT FUEL CELL MO, V2 SEBASTIAN PJ, UNPUB INT J HYDROGEN SOLORZA O, 1996, 11 C IB EL 9 ENC VEN SOLORZAFERIA O, 1994, ELECTROCHIM ACTA, V39, P1647 SOLORZAFERIA O, 1997, THIN SOLID FILMS, V311, P164 NR 9 TC 4 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0360-3199 J9 INT J HYDROGEN ENERG JI Int. J. Hydrog. Energy PD MAR PY 2000 VL 25 IS 3 BP 243 EP 247 PG 5 SC Chemistry, Physical; Energy & Fuels; Environmental Sciences; Physics, Atomic, Molecular & Chemical GA 266LR UT ISI:000084301900008 ER PT J AU Sebastian, PJ TI Chemical synthesis and characterization of MoxRuySez-(CO)(n) electrocatalysts SO INTERNATIONAL JOURNAL OF HYDROGEN ENERGY LA English DT Article ID METAL-CLUSTERS; FUEL; CATALYSIS; CHEMISTRY; OSMIUM AB MoxRuySez-(CO)(n) electrocatalyst was prepared by a chemical pyrolysis of Ru-3(CO)(12) + Mo(CO)(6) + Se mixture at 140 degrees C and sintering in Se atmosphere in a tubular furnace at 250 degrees C. The catalyst was characterized using techniques such as XRD (X-ray diffraction) SEM (scanning electron microscopy), TEM (transmission electron microscopy), voltametry and polarization (current-potential) measurements. The results indicated that chemically synthesized MoxRuySez-(CO)(n) is near amorphous in nature and possesses appreciable catalytic activity for oxygen reduction reaction in a polymer electrolyte (nafion membrane) fuel cell. The electrocatalytic activity seems to diminish with Se incorporation in the lattice of the Mo-Ru-carbonyl clusters formed during synthesis. (C) 1999 International Association for Hydrogen Energy. Published by Elsevier Science Ltd. All rights reserved. C1 UNAM, Solar Hydrogen Fuel Cell Grp, Energy Res Ctr, Temixco 62580, Morelos, Mexico. RP Sebastian, PJ, UNAM, Solar Hydrogen Fuel Cell Grp, Energy Res Ctr, Temixco 62580, Morelos, Mexico. CR ADAMS RD, 1985, POLYHEDRON, V4, P2003 BOND AM, 1997, COORDIN CHEM REV, V166, P161 DEEMING AJ, 1995, COMPREHENSIVE ORGANO, V7, P684 FOURNIER J, 1997, J ELECTROCHEM SOC, V144, P145 GATES BC, 1995, CHEM REV, V95, P511 LIN Z, 1997, STRUCTURAL ELECT PAR MUETTERTIES EL, 1983, ANGEW CHEM INT EDIT, V22, P135 RIAZ U, 1994, J AM CHEM SOC, V116, P4357 RODRIGUEZ FJ, 1996, INT MAT RES C, P25 RODRIGUEZ FJ, 1998, INT J HYDROGEN ENERG, V23, P1031 ROMERO T, 1998, INT J HYDROGEN ENERG, V23, P1041 ROMERO T, 1999, J NEW MAT ELECT SYST, V2, P111 ROTHSTEIN J, 1996, INT J HYDROGEN ENERG, V21, P137 SEBASTIAN PJ, UNPUB INT J HYDROGEN SHI CN, 1995, PURE APPL CHEM, V67, P319 SHRIDHAR L, 1995, IEEE T ENERGY CONVER, V10, P10 TAVAGNACCO C, 1998, J ELECTROANAL CHEM, V448, P41 WONG WT, 1998, J CHEM SOC DALT 0421, P1253 YE SY, 1997, J ELECTROCHEM SOC, V144, P90 NR 19 TC 3 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0360-3199 J9 INT J HYDROGEN ENERG JI Int. J. Hydrog. Energy PD MAR PY 2000 VL 25 IS 3 BP 255 EP 259 PG 5 SC Chemistry, Physical; Energy & Fuels; Environmental Sciences; Physics, Atomic, Molecular & Chemical GA 266LR UT ISI:000084301900010 ER PT J AU Leyvraz, F TI Scaling and crossover properties of a new solvable model of aggregation kinetics SO JOURNAL OF PHYSICS A-MATHEMATICAL AND GENERAL LA English DT Article ID SMOLUCHOWSKI COAGULATION EQUATION; POLYMERIZATION AB In a previous paper, a new reaction kernel for the Smoluchowski equations of aggregation was solved exactly. This kernel, K(j, k) = 2 - q(j) - q(k), for 0 < q < 1 a real positive quantity, interpolates between two well understood exactly solved cases, namely that of K(j, k) = 2 and that of K(j, k) = j + k. This new model, however, shows a number of unexpected features, not found in either of the two limiting cases. It is shown that this model has a remarkable behaviour with respect to the commonly accepted scaling theory. On the one hand, it satisfies a rigorous form of the scaling hypothesis, but, on the other hand, it clearly violates some relations which are ordinarily assumed to follow from it. These issues are discussed, as well as the nature of the singular limit in which q is very close to one, for which our kernel becomes close to the sum kernel mentioned above. In particular, the form of the crossover between two kernels with different degrees of homogeneity can be discussed here in an exact way. C1 Ctr Int Ciencias, Cuernavaca, Morelos, Mexico. Univ Mexico, Ctr Ciencias Fis, Cuernavaca, Morelos, Mexico. RP Leyvraz, F, Ctr Int Ciencias, Cuernavaca, Morelos, Mexico. CR CALOGERO F, 1999, J PHYS A-MATH GEN, V32, P7697 CHANDRASEKHAR S, 1943, REV MOD PHYS, V15, P1 ERNST MH, 1984, J PHYS A, V17, P2137 FRIEDLANDER SK, 1966, J COLLOID INTERF SCI, V22, P126 GASPER G, 1990, ENCY MATH ITS APPL, V35 HENDRIKS EM, 1983, J STAT PHYS, V31, P519 KOLB M, 1984, PHYS REV LETT, V53, P1653 LEYVRAZ F, 1980, J PHYS A, V13, P1867 LEYVRAZ F, 1982, J PHYS A, V15, P1951 LEYVRAZ F, 1986, PHYS REV LETT, V57, P163 LEYVRAZ F, 1987, PHYS REV A, V36, P4033 LUSHNIKOV AA, 1973, J COLLOID INTERF SCI, V45, P549 SMOLUCHOWSKI MV, 1916, PHYS Z, V17, P557 SPOUGE JL, 1983, J PHYS A-MATH GEN, V16, P767 VANDONGEN PGJ, 1983, J PHYS A, V16, L327 VANDONGEN PGJ, 1985, PHYS REV LETT, V54, P1396 VANDONGEN PGJ, 1987, PHYSICA A, V145, P15 VANDONGEN PGJ, 1988, J STAT PHYS, V50, P295 VICSEK T, 1984, PHYS REV LETT, V52, P1669 WHITTAKER ET, 1944, COURSE MODERN ANAL ZIFF RM, 1980, J STAT PHYS, V23, P241 NR 21 TC 6 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0305-4470 J9 J PHYS-A-MATH GEN JI J. Phys. A-Math. Gen. PD NOV 5 PY 1999 VL 32 IS 44 BP 7719 EP 7744 PG 26 SC Physics, Multidisciplinary; Physics, Mathematical GA 259FK UT ISI:000083883700013 ER PT J AU Sanchez-Gonzalez, M Alagon, A Rodriguez-Sotres, R Lopez-Munguia, A TI Proteolytic processing of dextransucrase of Leuconostoc mesenteroides SO FEMS MICROBIOLOGY LETTERS LA English DT Article DE dextransucrase molecular mass; protease; Leuconostoc mesenteroides ID MULTIPLE FORMS; PROTEINS; MUTANTS AB Various dextransucrase molecular mass forms found in enzyme preparations may sometimes be products of proteolytic activity. Extracellular protease in Leuconostoc mesenteroides strains NRRL B-512F and B-512FMC dextransucrase preparations was identified. Protease had a molecular mass of 30 kDa and was the predominant form derived from a high molecular mass precursor. The production and activity of protease in culture medium was strongly dependent on pH. When L. mesenteroides dextransucrase (173 kDa) was hydrolyzed by protease, at pH 7 and 37 degrees C, various dextransucrase forms with molecular masses as low as 120 kDa conserving dextransucrase activity were obtained. (C) 1999 Published by Elsevier Science B.V. All rights reserved. C1 Univ Nacl Autonoma Mexico, Inst Biotecnol, Cuernavaca 62271, Morelos, Mexico. Natl Autonomous Univ Mexico, Fac Quim, Dept Bioquim, Mexico City 04510, DF, Mexico. RP Lopez-Munguia, A, Univ Nacl Autonoma Mexico, Inst Biotecnol, Apdo Postal 510-3, Cuernavaca 62271, Morelos, Mexico. CR ALSOP RM, 1983, PROGR IND MICROBIOL, V18, P1 BRADFORD MM, 1976, ANAL BIOCHEM, V72, P248 CREIGHTON TE, 1993, PROTEINS STRUCTURES, P1 FU DT, 1990, PREP BIOCHEM, V20, P93 GRAHAME DA, 1984, BIOCHIM BIOPHYS ACTA, V786, P42 HARRINGTON DJ, 1994, FEMS MICROBIOL LETT, V121, P237 HENSEN C, 1980, ANAL BIOCHEM, V102, P196 HOMER KA, 1990, FEMS MICROBIOL LETT, V67, P257 KIM D, 1994, ENZYME MICROB TECH, V16, P1010 KIM D, 1994, ENZYME MICROB TECH, V16, P659 KING TP, 1983, MOL IMMUNOL, V20, P297 KOBAYASHI M, 1980, BIOCHIM BIOPHYS ACTA, V614, P46 KOBAYASHI M, 1986, J BIOCHEM-TOKYO, V100, P615 LAEMMLI UK, 1970, NATURE, V227, P680 MILLER A, 1986, BIOCHIM BIOPHYS ACTA, V80, P198 NORTH MJ, 1989, PROTEOLYTIC ENZYMES, P105 QUIRASCO M, IN PRESS APPL ENV MI ROBYT JF, 1986, ENCY POLYM SCI ENG, V4, P752 ROBYT JF, 1995, ADV CARBOHYD CHEM BI, V51, P133 SMITH MR, 1997, APPL ENVIRON MICROB, V63, P581 WILKEDOUGLAS M, 1989, 12386, US NR 21 TC 4 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0378-1097 J9 FEMS MICROBIOL LETT JI FEMS Microbiol. Lett. PD DEC 1 PY 1999 VL 181 IS 1 BP 25 EP 30 PG 6 SC Microbiology GA 258NC UT ISI:000083844400004 ER PT J AU Vidal, VMV Vidal, FV Meza, E Portilla, J Zambrano, L Jaimes, B TI Ring-slope interactions and the formation of the western boundary current in the Gulf of Mexico SO JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS LA English DT Article ID LOOP CURRENT EDDY; OF-MEXICO; STREAM RINGS; EVOLUTION; TOPOGRAPHY AB Hydrographic data from the Gulf of Mexico (gulf) provide evidence that a western boundary current was set up by the interaction of an anticyclonic Loop Current (LC) ring with the continental margin of the western gulf during March-August 1985. The March 1985 geostrophic circulation reveals a remnant anticyclonic ring colliding with the slope. During this collision, two cyclonic rings were shea as the anticyclone transferred vorticity to the surrounding slope water. During July-August 1985, the ring triad weakened and evolved into a similar to 900-km-long, north flowing, along-slope, western boundary current and cyclonic-anticyclonic ring pairs distributed throughout the central and western gulf. This western boundary current attained maximum northward flow speeds of 25 cm s(-1) and an 8.3-Sv mass transport between 94 degrees-96 degrees W at 25 degrees N. Our March-August 1985 observations reveal that the residence time and decay period of LC anticyclones in the western gulf may exceed 150 days. Within this time period the western gulf's cyclonic-anticyclonic vorticity field decayed similar to 50%. Thus the western boundary current's evolutionary period, from its gestation to its absolute decay, is estimated to be of the order of 300 days. Although the presence of a western boundary current in the gulf has been attributed to the annual wind stress curl cycle [Sturges, 1993], our analyses of the western gulf March and July-August 1985 ring-driven geostrophic circulation and corresponding (January, February and May, June 1985) monthly mean synoptic wind stress curl distributions reveal that these constitute competing forcing mechanisms for the gulf's regional circulation. However, when very strong local forcing such as large eddies are present, the wind-driven background circulation is overwhelmed by such eddy forcing. C1 Inst Politecn Nacl, Ctr Invest Ciencia Aplicada & Tecnol Avanzada, Grp Estudios Oceanog, Cuernavaca 62001, Morelos, Mexico. RP Vidal, VMV, Inst Politecn Nacl, Ctr Invest Ciencia Aplicada & Tecnol Avanzada, Grp Estudios Oceanog, Apartado Postal 1-475, Cuernavaca 62001, Morelos, Mexico. 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Geophys. Res.-Oceans PD SEP 15 PY 1999 VL 104 IS C9 BP 20523 EP 20550 PG 28 SC Oceanography GA 251YD UT ISI:000083473200004 ER PT J AU Avila, YR Cadena, JNA TI Chaetognath species composition from a coral reef lagoon in the Mexican Caribbean Sea SO REVISTA DE BIOLOGIA TROPICAL LA English DT Article DE coral reef; chaetognath; taxonomy; abundance; Caribbean sea ID ZOOPLANKTON AB Monthly species composition and abundance of Chaetognaths from January to December 1991 at two sampling sites, from the Puerto Morelos coral reef lagoon were examined. The species were: Ferosagitta hispida, Flaccisagitta enflata, Flaccisagitta hexaptera, Krohnitta pacifica, Pterosagitta draco. Sagitta bipunctata, Sagitta helenae, Sagitta tenuis and Serratosagitta serratodentata, most of them being common at both survey areas. F. hispida (station A: 2 801 org./100m(3); station B: 11 285 org./100m(3)) and F: enflata (station A:2 878 org./100m(3); station B: 5 470 org./100m(3)) were the most abundant species, representing more than 90% of the total capture. Maximum numbers were registered in the rainy season and minimal in the "Nortes" season. The remaining species were not collected consistently and due to their sporadic caught and scarcity it was not possible to determine any abundance pattern. The coral reef lagoon presented stenohaline conditions (+/-1.2 psu all the year round); temperatures showed also small changes (+/-1.6 degrees C) and varied according to the season, being highest during the dry and rainy periods and slightly lower in the "Nortes". C1 UNAM, Estac Puerto Morelos, Inst Ciencias Mar & Limnol, Cancun 77501, Q Roo, Mexico. RP Avila, YR, UNAM, Estac Puerto Morelos, Inst Ciencias Mar & Limnol, Apartado Postal 1152, Cancun 77501, Q Roo, Mexico. CR ALMEIDAPRADO MS, 1968, B I OCEANOGR U SAO P, V17, P35 ALVAREZCADENA JN, 1996, B MAR SCI, V58, P694 ALVAREZCADENA JN, 1996, GULF RES REP, V9, P197 ALVAREZCADENA JN, 1998, CRUSTACEANA, V71, P41 ALVARINO A, 1964, PAC SCI, V18, P64 ALVARINO A, 1965, OCEANOGR MAR BIOL AN, V3, P115 BIERI R, 1991, GULF RES REP, V8, P221 DUNBAR MJ, 1962, J MAR RES, V20, P76 FEIGENBAUM DL, 1984, OCEANOGR MAR BIOL, V22, P343 GARCIA E, 1964, MODIFICACIONES SISTE GASWCA S, 1996, CARIBB MAR STUD, V5, P41 KING KR, 1979, J PLANKTON RES, V1, P153 LEGARE JEH, 1961, B I OCEANOGR U ORIEN, V1, P1 MCLELLAND JA, 1984, NE GULF SCI, V7, P49 MCLELLAND JA, 1989, GULF RES REP, V8, P145 MERINO IM, 1991, ATLAS AMBIENTAL COST MERINO M, 1986, AN I CIENC MAR LIMNO, V13, P31 MICHEL HB, 1976, CARIBBEANB ZOOPLAN 1 MICHEL HB, 1984, 15 NOAA NMFS US DEP MOSTAJO LE, 1978, PHYSIS A, V38, P47 OMORI M, 1994, METHODS MARINE ZOOPL ORESLAND V, 1986, MAR ECOL-PROG SER, V29, P55 ORESLAND V, 1990, MAR ECOL-PROG SER, V63, P201 OWRE HB, 1960, B MAR SCI GULF CARIB, V10, P255 REEVE MR, 1972, BIOL BULL, V143, P207 RUSSELL FS, 1935, J MAR BIOL ASSOC UK, V20, P309 SUAREZCAABRO JA, 1955, MEM SOC CUBA HIST NA, V22, P125 SUAREZMORALES E, 1990, DIVERSIDAD BIOL RESE, P137 SUAREZMORALES E, 1994, CARIBB J SCI, V30, P116 SWEATT AJ, 1985, BIOL BULL, V168, P32 YOUNGBLUTH MJ, 1979, NE GULF SCI, V3, P15 YOUNGBLUTH MJ, 1980, ESTUARINE COASTAL MA, V10, P265 NR 32 TC 0 PU REVISTA DE BIOLOGIA TROPICAL PI SAN JOSE PA UNIVERSIDAD DE COSTA RICA CIUDAD UNIVERSITARIA, SAN JOSE, COSTA RICA SN 0034-7744 J9 REV BIOL TROP JI Rev. Biol. Trop. PD MAR PY 1999 VL 47 SU Suppl. 1 BP 157 EP 163 PG 7 SC Biology GA 247EG UT ISI:000083207200020 ER PT J AU Gonzalez-Rodriguez, JG Salinas-Bravo, VM Martinez-Villafane, A TI Stress corrosion cracking of type 403 stainless steel in sodium chloride at 95 degrees C under different heat treatment conditions SO CORROSION LA English DT Article DE annealing; hydrogen embrittlement; martensitic stainless steel; slow strain rate tests; sodium chloride; stress corrosion cracking AB Slow strain rare tests were used to evaluate the effect of heat treatment on the stress corrosion cracking (SCC) susceptibility of type AISI 403 (UNS S40300) martensitic stainless steel in 20% sodium chloride (NaCl) at 95 degrees C. Heat treatments included water-quenched, quenched, and tempered at 200 degrees C, 400 degrees C, and 600 degrees C and annealed at 850 degrees C, When tested in oil (90 degrees C), the highest loss in ductility was shown by the quenched specimen, and the lowest by the annealed specimen. Between these two specimens, there were specimens tempered at 200 degrees C, 400 degrees C, and 600 degrees C, respectively, When tested in 20% NaCl (wt%) at pH 7, 6, and 5, all specimens were embrittled by the environment, the most severe one being the solution with pH 5, showing at least 50% reduction in the elongation exhibited in oil. Fracture morphology was completely intergranular along the prior austenite for the quenched specimen and completely transgranular for the annealed specimen. The percentage of intergranular cracking decreased as the tempering temperature increased from 200 degrees C to 600 degrees C, and as the pH increased from 5 to 7, The fracture mechanism was thought to be hydrogen embrittlement. C1 UAEM Fac Ciencias Quim & Ingn 1, Cuernavaca 62215, Morelos, Mexico. Inst Invest Elect, Dept Proc Term, Cuernavaca 62001, Morelos, Mexico. CIMAV, Chih, Mexico. RP Gonzalez-Rodriguez, JG, UAEM Fac Ciencias Quim & Ingn 1, Av Univ 1001, Cuernavaca 62215, Morelos, Mexico. CR DESANTAMARIA MS, 1989, CORROS SCI, V29, P69 ELSAYED HA, 1981, SURF TECHNOL, V16, P245 ELSAYED HA, 1986, CORROS PREV CONT, V12, P142 GOUDA VK, 1983, SURF TECHNOL, V18, P327 LINDINGER RJ, 1981, CORROSION 81 MAIER I, 1980, CORROSION, V36, P60 MATSUI H, 1979, MATER SCI ENG, V40, P207 SCULLY JC, 1973, STRESS CORROSION CRA, V10, P496 SHALVOY RS, 1981, CORROSION 81 SPAHN H, 1988, ENV INDUCED CRACKING, V10, P449 VISWANATHAN R, 1991, P LIF PRED CORR STRU NR 11 TC 0 PU NATL ASSN CORROSION ENG PI HOUSTON PA 1440 SOUTH CREEK DRIVE, HOUSTON, TX 77084-4906 USA SN 0010-9312 J9 CORROSION JI Corrosion PD OCT PY 1999 VL 55 IS 10 BP 991 EP 996 PG 6 SC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering GA 245RA UT ISI:000083120900011 ER PT J AU Reyes, P Pickard, MA Vazquez-Duhalt, R TI Hydroxybenzotriazole increases the range of textile dyes decolorized by immobilized laccase SO BIOTECHNOLOGY LETTERS LA English DT Article DE dye; immobilized enzyme; laccase; mediators; textile wastewater ID WHITE-ROT FUNGI; PHANEROCHAETE-CHRYSOSPORIUM; TRAMETES-VERSICOLOR; ORGANIC-SOLVENTS; LIGNIN PEROXIDASE; DEGRADATION; AZO; OXIDATION; BIODEGRADATION; MINERALIZATION AB Laccase from Coriolopsis gallica UAMH8260 was immobilized on activated agarose and tested for repeated decolorization of industrial dyes. Immobilized enzyme retained 85% of the initial activity after 10 cycles, and 70% after 3 months of intermittant use in the decolorization of Reactive Blue 198 dye. Free laccase decolorized 13 of 38 industrial dyes tested but, in the presence of 1 mM 1-hydroxybenzotriazole as a free radical mediator, the enzyme decolorized 26 of the 38 dyes increasing both the range and rate of decolorization. Immobilized laccase showed a higher thermal stability at 70 degrees C than free enzyme but no increased resistance to organic solvents. C1 UNAM, Inst Biotecnol, Cuernavaca 62250, Morelos, Mexico. Univ Alberta, Dept Biol Sci, Edmonton, AB T6G 2E9, Canada. RP Vazquez-Duhalt, R, UNAM, Inst Biotecnol, Apartado Postal 510-3, Cuernavaca 62250, Morelos, Mexico. CR *EPA, 1996, EPA625R96004 ARCHIBALD F, 1990, ENZYME MICROB TECH, V12, P846 ARJMAND M, 1985, J AGR FOOD CHEM, V33, P1055 BEAUDETTE LA, 1998, APPL ENVIRON MICROB, V64, P2020 BOGAN BW, 1996, APPL ENVIRON MICROB, V62, P1597 BOURBONNAIS R, 1990, FEBS LETT, V267, P99 BROWN D, 1981, CHEMOSPHERE, V10, P245 CHIVUKULA M, 1995, APPL ENVIRON MICROB, V61, P4374 CHUNG KT, 1992, CRIT REV MICROBIOL, V18, P175 CRIPPS C, 1990, APPL ENVIRON MICROB, V56, P1114 DAMKUS T, 1996, 06930, WO DAVIS S, 1992, APPL MICROBIOL BIOT, V37, P474 GORONTZY T, 1994, CRIT REV MICROBIOL, V20, P265 HUTZINGER O, 1980, HDB ENV CHEM A, V3 JOHANNES C, 1996, APPL MICROBIOL BIOT, V46, P313 KIRBY N, 1995, BIOTECHNOL LETT, V17, P761 KULKARNI SV, 1985, EPA600285010 KULLMAN SW, 1996, APPL ENVIRON MICROB, V62, P593 LUTEREK J, 1998, HOLZFORSCHUNG, V52, P589 MAJCHERCZYK A, 1998, ENZYME MICROB TECH, V22, P335 MICHAELS GB, 1985, ENVIRON TOXICOL CHEM, V4, P45 MILSTEIN O, 1989, APPL MICROBIOL BIOT, V31, P70 MILSTEIN O, 1993, J BIOTECHNOL, V30, P37 MUNOZ C, 1997, APPL ENVIRON MICROB, V63, P2166 OLLIKKA P, 1993, APPL ENVIRON MICROB, V59, P4010 PAGGA U, 1986, CHEMOSPHERE, V15, P479 PASZCZYNSKI A, 1991, BIOCHEM BIOPH RES CO, V178, P1056 PICKARD MA, 1999, IN PRESS APPL ENV MI, V65 REID ID, 1994, FEMS MICROBIOL REV, V13, P369 RODRIGUEZ E, 1999, CURR MICROBIOL, V38, P27 ROGALSKI J, 1999, J MOL CATAL B-ENZYM, V6, P29 RUCKENSTEIN E, 1994, BIOTECHNOL BIOENG, V44, P79 SASEK V, 1993, BIOTECHNOL LETT, V15, P521 SCHLIEPHAKE K, 1996, BIOTECHNOL LETT, V18, P881 SHIN KS, 1997, APPL ENVIRON MICROB, V63, P1744 TAKADA S, 1996, APPL ENVIRON MICROB, V62, P4323 VASDEV K, 1995, CURR MICROBIOL, V30, P268 NR 37 TC 38 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0141-5492 J9 BIOTECHNOL LETT JI Biotechnol. Lett. PD OCT PY 1999 VL 21 IS 10 BP 875 EP 880 PG 6 SC Biotechnology & Applied Microbiology GA 243BH UT ISI:000082976900007 ER PT J AU Calixto, ME Sebastian, PJ Bhattacharya, RN Noufi, R TI Compositional and optoelectronic properties of CIS and CIGS thin films formed by electrodeposition SO SOLAR ENERGY MATERIALS AND SOLAR CELLS LA English DT Article DE CIS; CIGS; thin films; film deposition ID CUINSE2 AB CuInSe2 (CIS) and Cu(In,Ga)Se-2 (CIGS) thin films were prepared by electrodeposition and processing. The influence of film deposition parameters such as bath composition, pH, deposition potential and material purity on film properties was studied. The structural, morphological, compositional and opto-electronic properties of electrodeposited and selenized CIS and CIGS thin films were characterized using various techniques. As-deposited as well as selenized films exhibited a compact or a granular morphology depending on the composition. The film stoichiometry was improved after selenization at 550 degrees C in a tubular furnace. The films are formed with a mixed phase composition of CuInSe2 and CuIn2Se3.5 ternary phases. (C) 1999 Elsevier Science B.V. All rights reserved. C1 UNAM, Ctr Invest Energia, Solar H2 Fuel Cell Area, Temixco 62580, Morelos, Mexico. NREL, Golden, CO USA. RP Calixto, ME, UNAM, Ctr Invest Energia, Solar H2 Fuel Cell Area, Temixco 62580, Morelos, Mexico. CR BHATTACHARYA RN, 1983, J ELECTROCHEM SOC, V130, P2040 CONTRERAS MA, 1994, P 1 WORLD C PHOT EN, P68 GUILLEN C, 1995, J ELECTROCHEM SOC, V142, P1834 HERRERO J, 1991, J APPL PHYS, V69, P429 JEYAKUMAR R, 1994, MATER RES BULL, V29, P195 KAPUR VK, 1987, SOL CELLS, V21, P65 LINCOT D, 1994, P 1 WORLD C PHOT EN, P136 QUI CX, 1989, J PHYS, V67, P444 ROCKETT A, 1994, THIN SOLID FILMS, V237, P1 SEBASTIAN PJ, 1998, J ELECTROCHEM SOC, V145, P3613 THOUIN L, 1992, P 11 EC PHOT SOL EN, P866 THOUIN L, 1995, J ELECTROCHEM SOC, V142, P2996 NR 12 TC 8 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0927-0248 J9 SOLAR ENERG MATER SOLAR CELLS JI Sol. Energy Mater. Sol. Cells PD SEP PY 1999 VL 59 IS 1-2 BP 75 EP 84 PG 10 SC Energy & Fuels; Materials Science, Multidisciplinary GA 233YV UT ISI:000082455500009 ER PT J AU Mathew, X Sebastian, PJ TI Optical properties of electrodeposited CdTe thin films SO SOLAR ENERGY MATERIALS AND SOLAR CELLS LA English DT Article DE CdTe; thin films; optical properties AB The absorption coefficient spectra of the electrodeposited CdTe thin films were analyzed and compared with that of the single crystal. Pinhole-free thin films facilitated the analysis of the high-energy regions of the absorption coefficient spectra. The various allowed direct and indirect transitions were detected successively by subtracting the extrapolated values of the lower-energy transitions. The effect of heat treatment on the optical transitions were analyzed with films annealed at 300 degrees C in air, argon and CdCl2. The direct band gap of the electrodeposited films decreased with increasing film thickness and approaches the value of the single crystal. The films annealed at different environments show slightly lower value for the band gap. Annealing in argon caused significant change in the optical transition spectra. (C) 1999 Elsevier Science B.V. All rights reserved. C1 UNAM, Ctr Invest Energia, Solar HYdrogen Fuel Cell Grp, Temixco 62580, Morelos, Mexico. RP Mathew, X, UNAM, Ctr Invest Energia, Solar HYdrogen Fuel Cell Grp, Temixco 62580, Morelos, Mexico. CR AMIRTHARAJ PM, 1991, HDB OPTICAL CONSTANT, V2, P655 ARWIN H, 1984, J VAC SCI TECHNOL A, V2, P1316 BASOL BM, 1988, SOL CELLS, V23, P69 BELL RO, 1977, REV PHYS APPL, V12, P391 BRITT J, 1993, APPL PHYS LETT, V62, P2851 BROWN HM, 1972, CAN JPHYS, V50, P2502 CHOUDHURI S, 1987, THIN SOLID FILMS, V147, P9 COHEN ML, 1966, PHYS REV, V141, P789 CONNELL GAN, 1973, PHYS STATUS SOLIDI B, V60, P291 DANAHER WJ, 1984, AUST J CHEM, V37, P689 DOW JD, 1970, PHYS REV B-SOLID ST, V1, P3358 DUBROVSKY GB, 1961, SOV PHYS-SOLID STATE, V3, P943 ELSHAZLY AA, 1981, THIN SOLID FILMS, V78, P287 KIREEV PS, 1972, SOV PHYS SEMICOND, V6, P109 LEWIS JE, 1987, PHYS STATUS SOLIDI B, V143, P307 MARPLE DTF, 1966, PHYS REV, V150, P728 MYERS TH, 1981, J APPL PHYS, V52, P4231 OU SS, 1984, J APPL PHYS, V55, P3769 RAKHSHANI AE, 1997, J APPL PHYS, V81, P7988 RAPPAPORT P, 1961, ACTA ELECT, V5, P364 REDFIELD D, 1967, APPL PHYS LETT, V11, P138 SAHA S, 1989, PHYS STATUS SOLIDI A, V114, P721 NR 22 TC 28 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0927-0248 J9 SOLAR ENERG MATER SOLAR CELLS JI Sol. Energy Mater. Sol. Cells PD SEP PY 1999 VL 59 IS 1-2 BP 85 EP 98 PG 14 SC Energy & Fuels; Materials Science, Multidisciplinary GA 233YV UT ISI:000082455500010 ER PT J AU Gamboa, SA Sebastian, PJ Mathew, X Nguyen-Cong, H Chartier, P TI A CdTe/PMeT photovoltaic structure formed by electrodeposition and processing SO SOLAR ENERGY MATERIALS AND SOLAR CELLS LA English DT Article DE CdTe; thin films; electrodeposition ID CDTE-FILMS; DEPOSITION; JUNCTION; CELLS; CVTG AB CdTe thin films were electrodeposited from an ethylene-glyco-based bath by the galvanostatic method. As-deposited and tellurized films were characterized by structural, optoelectronic and photoelectrochemical methods. The film stoichiometry improved after tellurization of the film at 300 degrees C by a technique called chemical vapor transport by Gas (CVTG) in a tubular furnace. Tellurized films showed near stoichiometry with p-type conductivity in the bulk and n-type surface conductivity. Schottky barrier type photovoltaic junctions were obtained using a heavily doped PMeT (poly-3(methylthiophene), prepared by electropolymerization, displaying nearly metallic behavior, and CdTe obtained by electrodeposition. A solar to electrical conversion efficiency of the order of 1% was obtained in the case of PMeT/CdTe junction. (C) 1999 Elsevier Science B.V. All rights reserved. C1 UNAM, CIE, Solar H2 Fuel Cell Grp, Temixco 62580, Morelos, Mexico. Univ Strasbourg 1, Fac Chim, Lab Electrochim & Chim Phys Corps Solide, Strasbourg, France. RP Gamboa, SA, UNAM, CIE, Solar H2 Fuel Cell Grp, Temixco 62580, Morelos, Mexico. CR BOCKRIS JO, 1989, MATER CHEM PHYS, V22, P249 CARLOS A, 1996, ADV MATER OPT ELECTR, V7, P29 CHARTIER P, 1998, SOL ENERG MAT SOL C, V52, P413 DAS SK, 1993, SOL ENERG MAT SOL C, V30, P107 FRANK AJ, 1989, J PHYS CHEM-US, V93, P3818 GAMBOA SA, 1998, SOL ENERG MAT SOL C, V52, P293 GOMES WP, 1982, PROG SURF SCI, V12, P155 GUO YP, 1993, SOL ENERG MAT SOL C, V29, P115 HOROWITZ G, 1986, SOL ENERG MATER, V13, P47 KKOLYER CL, 1992, J ELECTROCHEM SOC, V139, P406 KROGER FA, 1978, J ELECTROCHEM SOC, V125, P2028 LOAEZA P, 1990, J MATER SCI LETT, V9, P11 MAUSIN G, 1986, J ELECTROANAL CHEM, V202, P323 NGUYENCONG H, 1993, SOLAR ENERGY MAT SOL, V29, P127 NGUYENCONG H, 1993, SOLAR ENERGY MAT SOL, V30, P209 NGUYENCONG H, 1995, J CHIM PHYS PCB, V92, P979 NGUYENCONG H, 1996, SOLAR ENERGY MAT SOL, V40, P261 PANDEY RK, 1992, SOL ENERG MAT SOL C, V26, P285 RAJESHWAR K, 1992, ADV MATER, V4, P1 RASTOGI AC, 1995, SOL ENERG MAT SOL C, V36, P121 SEBASTIAN PJ, 1996, J PHYS D APPL PHYS, V29, P1356 TAKAHASHI M, 1985, J APPL PHYS, V58, P4292 NR 22 TC 5 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0927-0248 J9 SOLAR ENERG MATER SOLAR CELLS JI Sol. Energy Mater. Sol. Cells PD SEP PY 1999 VL 59 IS 1-2 BP 115 EP 124 PG 10 SC Energy & Fuels; Materials Science, Multidisciplinary GA 233YV UT ISI:000082455500012 ER PT J AU Olea, A Ponce, G Sebastian, PJ TI Electron transfer via organic dyes for solar conversion SO SOLAR ENERGY MATERIALS AND SOLAR CELLS LA English DT Article DE dye-sensitized solar cells; TiO2; absorption ID LOW-COST; LIGHT AB The dye-sensitized solar cells are formed by a wide band gap semiconductor such as TiO2, an organic dye coated on the semiconductor for light absorption, an electrolyte containing a suitable redox couple and a counterelectrode. In the present study, we investigated the functioning of black berry extract to sensitize TiO2 for light absorption. TiO2 thick films were screen-printed and sintered at 450 degrees C in air. It was sensitized with a fruit extract that contains anthocynin kind of organic dye, for example black berry extract. The black berry extract sensitized TiO2 exhibited an increase in the photocurrent response indicating excess generation of photoelectrons due to light absorption by black berry extract. The photocurrent response in this case depends on parameters such as soaking time of TiO2 in black berry juice, period of illumination, etc. The black berry extract was analyzed by optical absorption spectroscopy to characterize its absorption band. An absorption peak was observed at 517 nm, the intensity of which depends on the concentration of the black berry extract. (C) 1999 Elsevier Science B.V. All rights reserved. C1 UNAM, CIE, Solar H2 Celda Combustible, Temixco 62580, Morelos, Mexico. UNAM, Inst Biotechnol, Chamilpa, Morelos, Mexico. RP Olea, A, UNAM, CIE, Solar H2 Celda Combustible, Temixco 62580, Morelos, Mexico. CR BEKKERMAN LI, 1976, RUSS J INORG CHEM, V21, P223 HAGFELDT A, 1995, CHEM REV, V95, P49 KAY A, 1996, SOL ENERG MAT SOL C, V44, P99 KEY A, 1996, SOLAR ENERGY MATER S, V44, P99 NAZEERUDDIN MK, 1993, J AM CHEM SOC, V115, P6382 OREGAN B, 1991, NATURE, V353, P737 PAPAGEORGIOU N, 1996, J ELECTROCHEM SOC, V143, P3099 REDMOND G, 1994, CHEM MATER, V6, P49 SMESTAD G, 1994, SOL ENERG MAT SOL C, V32, P259 WEISER HB, 1941, J PHYS CHEM-US, V45, P1227 NR 10 TC 7 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0927-0248 J9 SOLAR ENERG MATER SOLAR CELLS JI Sol. Energy Mater. Sol. Cells PD SEP PY 1999 VL 59 IS 1-2 BP 137 EP 143 PG 7 SC Energy & Fuels; Materials Science, Multidisciplinary GA 233YV UT ISI:000082455500014 ER PT J AU Nair, MTS Guerrero, L Arenas, OL Nair, PK TI Chemically deposited copper oxide thin films: structural, optical and electrical characteristics SO APPLIED SURFACE SCIENCE LA English DT Article DE thin film; copper oxide; chemical deposition ID IONIC-LAYER ADSORPTION; CU2O; GROWTH; ZNS; CDS AB Thin films of copper oxide with thickness ranging from 0.05-0.45 mu m were deposited on microscope glass slides by successively dipping them for 20 s each in a solution of 1 M NaOH and then in a solution of copper complex. Temperature of the NaOH solution was varied from 50-90 degrees C, while that of the copper solution was maintained at room temperature. X-ray diffraction patterns showed that the films, as prepared, are of cuprite structure with composition Cu2O. Annealing the films in air at 350 degrees C converts these films to CuO. This conversion is accompanied by a shift in the optical band gap from 2.1 eV (direct) to 1.75 eV (direct). The films show p-type conductivity, similar to 5 X 10(-4) Omega(-1) cm(-1)for a film of thickness 0.15 mu m. Electrical conductivity of this film increases by a factor of 3 when illuminated with 1 kW m(-2) tungsten halogen radiation. Annealing in a nitrogen atmosphere at temperatures up to 400 degrees C does not change the composition of the films. However, the conductivity in the dark as well as the photoconductivity of the film increases by an order of magnitude. The electrical conductivity of the CuO thin films produced by air annealing at 400 degrees C, is high, 7 X 10(-3) Omega(-1) cm(-1). These films are also photoconductive. (C) 1999 Elsevier Science B.V. All rights reserved. C1 Univ Nacl Autonoma Mexico, Ctr Invest Energia, Dept Solar Energy Mat, Temixco 62580, Morelos, Mexico. RP Nair, MTS, Univ Nacl Autonoma Mexico, Ctr Invest Energia, Dept Solar Energy Mat, Temixco 62580, Morelos, Mexico. CR AVELINE A, 1981, SOL ENERG MATER, V5, P211 BEENSHMARCHWICK.G, 1982, THIN SOLID FILMS, V88, P33 COTTON FA, 1980, ADV INORG CHEM, P801 GARCIA VM, 1997, SEMICOND SCI TECH, V12, P645 HODES G, 1987, PHYS REV B, V36, P4215 JIMENEZGONZAILE.AE, 1995, SEMICOND SCI TECH, V10, P1277 NAIR PK, 1998, SOL ENERG MAT SOL C, V52, P313 NICOLAU YF, 1985, APPL SURF SCI, V22, P1061 NICOLAU YF, 1988, J CRYST GROWTH, V92, P128 NICOLAU YF, 1990, J ELECTROCHEM SOC, V137, P2915 OLSEN LC, 1979, APPL PHYS LETT, V34, P47 OZER N, 1993, SOL ENERG MAT SOL C, V30, P13 PANKOV JD, 1978, IZV VUZ FIZ, V3, P126 RAI BP, 1988, SOL CELLS, V25, P265 RAKSHANI AE, 1986, SOLID STATE ELECTRON, V29, P7 RISTOV M, 1985, THIN SOLID FILMS, V123, P63 RISTOV M, 1987, THIN SOLID FILMS, V149, P65 RITCHHARIA P, 1990, SOLAR ENERGY MAT, V20, P199 ROSS A, 1983, SOLAR ENERGY MAT, V7, P467 TROTMANDICKENSO.AF, 1973, COMPREHENSIVE INORGA, V3, P16 VALKONEN MP, 1997, APPL SURF SCI, V120, P58 VALKONEN MP, 1998, APPL SURF SCI, V136, P131 VANDEHULST HC, 1981, LIGHT SCATTERING SMA, P114 VULETIN J, 1989, SOLAR ENERGY MAT, V19, P249 NR 24 TC 25 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0169-4332 J9 APPL SURF SCI JI Appl. Surf. Sci. PD AUG PY 1999 VL 150 IS 1-4 BP 143 EP 151 PG 9 SC Chemistry, Physical; Materials Science, Coatings & Films; Physics, Applied; Physics, Condensed Matter GA 234FE UT ISI:000082473200020 ER PT J AU Brostow, W Castano, VM Huanosta, A de Icaza, M Nicho, ME Saniger, JM TI Poly(acrylic acid) plus zinc diacetate composites: High temperature service and electric conductivity SO MATERIALS RESEARCH INNOVATIONS LA English DT Article DE high temperature polymers; polymer-based composites; poly(acrylic acid); zinc acetate; polymer electric conductivity; dynamic dielectric properties ID POLYACRYLIC-ACID; STRESS-RELAXATION; CEMENTS AB Poly(acrylic acid) + zinc diacetate hybrid composites have been prepared by precipitation from aqueous solutions and drying. The lowest glass transition temperature T-g determined by differential scanning calorimetry (DSC) Is 392 degrees C, providing a service temperature range unusually large for polymer-based materials (PBMs). Thermogravimetric analysis (TGA) shows that thermal decomposition begins some 10-20 K above each T-g. The alternating current impedance was determined in the nitrogen atmosphere from 370 degrees C to 530 degrees C. Dynamic dielectric measurements were performed between 20 degrees C and 350 degrees C, also under nitrogen. In contrast to typical PBMs, there is evidence of ionic conduction in some of the composites. The dynamic dielectric properties depend on the composition. The materials obtained are usable in medical applications and as high durability low friction coatings. C1 Univ N Texas, Dept Mat Sci, Denton, TX 76230 USA. Natl Autonomous Univ Mexico, Dept Appl Phys & Adv Technol, Queretaro 67000, Mexico. Natl Autonomous Univ Mexico, Inst Mat Res, Mexico City 04510, DF, Mexico. Elect Res Inst, Curenavaca 62000, Morelos, Mexico. Natl Autonomous Univ Mexico, Ctr Instrumentat, Mexico City 04510, DF, Mexico. RP Brostow, W, Univ N Texas, Dept Mat Sci, Denton, TX 76230 USA. CR BLONSKI S, 1994, PHYS REV B, V49, P6494 BROSTOW W, 1993, PHYS REV B, V47, P7659 BROSTOW W, 1996, PHYSICAL PROPERTIES, CH33 BROSTOW W, 1998, MECH THERMOPHYSICAL BROSTOW W, 1998, POLYM ENG SCI, V38, P204 BROSTOW W, 1999, IN PRESS POLYM ENG S, V39 FELDMAN D, 1996, SYNTHETIC POLYM TECH GIAMBERINI M, 1995, MOL CRYST LIQ CRYS A, V266, P9 HILL RG, 1991, J MATER SCI, V26, P69 HU H, 1991, MATER LETT, V12, P281 IRVINE JTS, 1990, ADV MATER, V2, P132 KUBAT J, 1982, PHYS STATUS SOLIDI B, V111, P599 KUBAT J, 1982, RES MECH, V5, P309 KUBAT J, 1986, FAILURE PLASTICS, CH4 MCDONALD JR, 1987, IMPEDANCE SPECTROSCO NARKIS M, 1995, POLYM POWDER TECHNOL NICHO ME, 1995, THESIS NATL AUTONOMO NICHO ME, 1997, J APPL POLYM SCI, V66, P861 NICHOLSON JW, 1987, BRIT POLYM J, V19, P67 NICHOLSON JW, 1993, J MATER SCI-MATER M, V4, P32 PADILLA A, 1992, MATER LETT, V12, P445 SANIGER JM, 1992, MATER LETT, V15, P113 SAWABY A, 1988, J MATER SCI LETT, V7, P1166 VELEZ D, 1994, MATER LETT, V19, P309 NR 24 TC 14 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 USA SN 1432-8917 J9 MATER RES INNOV JI Mater. Res. Innov. PD AUG PY 1999 VL 3 IS 2 BP 85 EP 91 PG 7 SC Materials Science, Multidisciplinary GA 229MH UT ISI:000082198000004 ER PT J AU Gonzalez-Rodriquez, JG Diaz-Sanchez, A Salinas-Bravo, VM TI Stress corrosion cracking of 17-4PH steel in steam turbine environments SO CORROSION REVIEWS LA English DT Article AB Slow strain rate tests (SSRT) were conducted to determine the susceptibility of the 17-4-PH type steel to stress corrosion cracking: (SCC) in simulated low pressure (LP) steam turbine environments. Environments tested included solutions of NaCl, NaOH and Na2SO4 at different pH values, electrochemical potentials, concentrations, mixtures and strain rates at 95 degrees C. It was concluded that this steel was susceptible to SCC in acidic NaCl solutions and with the application of both anodic and cathodic potentials and lowering of the strain rate. It is concluded that both hydrogen embrittlement and anodic dissolution mechanisms are responsible for the SCC susceptibility. C1 UAEM, Fac Ciencias Quim & Ingn, Cuernavaca, Morelos, Mexico. Inst Nacl Invest Nucl, Dept Mat, Salazar Edo de Mexico, Mexico. Inst Invest Elect Sistemas Combust, Cuernavaca 62001, Morelos, Mexico. RP Gonzalez-Rodriquez, JG, UAEM, Fac Ciencias Quim & Ingn, Av Univ 1001,CP 62215,Col Chamilpa, Cuernavaca, Morelos, Mexico. CR BERMAN DA, 1974, HYDROGEN METALS, P575 DEVANATHAN MAV, 1969, J ELECTROCHEM SOC, V111, P619 ELSAYED HA, 1981, SURF TECHNOL, V16, P245 ELSAYED HA, 1986, CORROS PREV CONT, V12, P142 GOUDA VK, 1983, SURF TECHNOL, V18, P327 LINDINGER RJ, 1981, CORROSION 81 LYLE FF, 1980, CORROSION 80 MARIA MSD, 1989, CORROS SCI, V29, P69 SCULLY JC, 1973, STRESS CORROSION CRA, P496 SHALABY HM, 1996, CORROSION, V52, P275 SHALVOY RS, 1981, CORROSION 81 SPACHN H, 1988, ENV INDUCED CRACKING, P449 STELTZ WG, 1980, WEST STEAM TURB GEN WEI RP, 1976, SCRIPTA METALL, V10, P153 NR 14 TC 0 PU FREUND PUBLISHING HOUSE LTD PI LONDON PA STE 500, CHESHAM HOUSE, 150 REGENT ST, LONDON W1R 5FA, ENGLAND SN 0048-7538 J9 CORROS REV JI Corros. Rev. PY 1999 VL 17 IS 2 BP 99 EP 112 PG 14 SC Electrochemistry; Metallurgy & Metallurgical Engineering; Materials Science, Coatings & Films GA 210HD UT ISI:000081098300002 ER PT J AU Almeraya-Calderon, F Martinez-Villafane, A Gonzalez-Rodriguez, JG TI Electrochemical studies of hot corrosion of type 347H stainless steel SO BRITISH CORROSION JOURNAL LA English DT Article ID CRACKING; NOISE; ALLOYS; NI AB Electrochemical studies of the hot corrosion of AISI SA 213 TP 347H stainless steel have been carried out in a mixture of 80 wt-% V2O5 + 20 wt% Na2SO4. The range of temperature was 540-680 degrees C at intervals of 20 K and the techniques employed included corrosion potential, Tafel polarisation, and electrochemical noise measurements. At 620 degrees C the corrosion potential, measured against a platinum reference electrode (PRE), decreases from -350 mV to -480 mV and remains at this level during the first 8 h. Using Tafel polarisation, it was found that, with change in the temperature from 540 to 680 degrees C, the corrosion potential decreased on initial heating to 600 degrees C and then increased again at higher temperatures, the corrosion rate increasing continuously with increasing temperature. However, at constant temperature (620 degrees C) the corrosion rate increased with time during the first 8 h, after which it decreased and reached a steady state after 27 h, probably owing to tlte formation of a surface film. Electrochemical noise measurements, of both voltage and current noise, indicated a combination of general corrosion, probably owing to the formation of a surface layer, and localised corrosion in the grain boundaries. C1 Ctr Invest Mat Avanzados, Chihuahua, Mexico. Univ Autonoma Estado Morelos, Fac Ciencias Quim & Ingn, Cuernavaca, Morelos, Mexico. CR HLADKY K, 1982, CORROS SCI, V22, P231 MANSFELD F, 1993, J ELECTROCHEM SOC, V140, P2205 NEWMAN RC, 1983, SCRIPTA METALL, V17, P621 NISHIKATA A, 1986, CORROSION, V42, P578 NUMATA H, 1983, P C JIMIS 3, P303 OKADA T, 1993, J ELECTROCHEM SOC, V140, P1261 RAHMEL A, 1982, OXID MET, V18, P195 SHIBATA T, 1989, CORROS ENG, V38, P175 SHORES DA, 1975, CORROSION, V31, P434 STEWART J, 1992, CORROS SCI, V33, P73 WELLS DB, 1992, CORROS SCI, V33, P39 WU WT, 1983, OXID MET, V19, P201 YAMAKAWA K, 1990, CORROS SCI, V31, P503 NR 13 TC 2 PU INST MATERIALS PI LONDON PA 1 CARLTON HOUSE TERRACE, LONDON SW1Y 5DB, ENGLAND SN 0007-0599 J9 BRIT CORROS J JI Br. Corros. J. PY 1998 VL 33 IS 4 BP 288 EP 291 PG 4 SC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering GA 209RW UT ISI:000081063500005 ER PT J AU Garcia, VM Nair, PK Nair, MTS TI Copper selenide thin films by chemical bath deposition SO JOURNAL OF CRYSTAL GROWTH LA English DT Article DE chemical bath deposition; electronic materials; copper selenide films ID ELECTROLESS DEPOSITION; N,N-DIMETHYLSELENOUREA; DEVICES; CU2-XSE AB We report the structural, optical, and electrical properties of thin films (0.05 to 0.25 mu m) of copper selenide obtained from chemical baths using sodium selenosulfate or N,N-dimethylselenourea as a source of selenide ions. X-ray diffraction (XRD) studies on the films obtained from baths using sodium selenosulfate suggest a cubic structure as in berzelianite, Cu2-xSe with x = 0.15. Annealing the films at 400 degrees C in nitrogen leads to a partial conversion of the films to Cu,Se. In the case of films obtained from the baths containing dimethylselenourea, the XRD patterns match that of klockmannite, CuSe. Annealing these films in nitrogen at 400 degrees C results in loss of selenium, and consequently a composition rich in copper, similar to Cu2-xSe, is reached. Optical absorption in the films result from free carrier absorption in the near infrared region with absorption coefficient of similar to 10(5) cm(-1). Band-to-band transitions which gives rise to the optical absorption in the visible-ultraviolet region may be interpreted in terms of direct allowed transitions with band gap in the 2.1-2.3 eV range and indirect allowed transitions with band gap 1.2-1.4 eV. All the films, as prepared and annealed, show p-type conductivity, in the range of (1-5) x 10(3) Omega(-1) cm(-1). This results in high near infrared reflectance, of 30-80%. (C) 1999 Elsevier Science B.V. All rights reserved. C1 Univ Nacl Autonoma Mexico, Ctr Invest Energia, Dept Solar Energy Mat, Temixco 62580, Morelos, Mexico. RP Nair, MTS, Univ Nacl Autonoma Mexico, Ctr Invest Energia, Dept Solar Energy Mat, Temixco 62580, Morelos, Mexico. CR BARRETT CS, 1966, STRUCTURE METALS, P155 BARROW GM, 1973, PHYSICAL CHEM, P668 BHATTACHARYA RN, 1997, P SOC PHOTO-OPT INS, V3138, P90 BULDHAUPT LF, 1983, THIN FILM SOLAR CELL CHOPRA KL, 1982, PHYS THIN FILMS, V12, P201 CHOPRA KL, 1983, THIN FILM SOLAR CELL ESTRADA CA, 1994, J ELECTROCHEM SOC, V141, P802 GARCIA VM, 1997, SEMICOND SCI TECH, V12, P645 GROZDANOV I, 1994, SEMICOND SCI TECH, V9, P1234 GROZDANOV I, 1994, SYNTHETIC MET, V63, P213 HARAM SK, 1994, THIN SOLID FILMS, V238, P21 HERMANN AM, 1983, J CRYST GROWTH, V61, P658 HODES G, 1987, PHYS REV B, V36, P4215 KORZHUEV MA, 1991, PHYS STATUS SOLIDI A, V123, P131 LOFERSKI JJ, 1956, J APPL PHYS, V27, P777 MADELUNG O, 1992, SEMICONDUCTORS OTHER, P51 MASSACCESI S, 1993, J ELECTROCHEM SOC, V140, P2540 MONDAL A, 1983, J SOLID STATE CHEM, V47, P81 MONDAL A, 1984, J SOLID STATE CHEM, V55, P116 NAIR PK, 1998, SOL ENERG MAT SOL C, V52, P313 OKIMURA H, 1980, THIN SOLID FILMS, V71, P53 PADAM GK, 1987, THIN SOLID FILMS, V150, L89 PAIN HJ, 1979, PHYSICS VIBRATIONS W SAKUMA T, 1989, J PHYS SOC JPN, V58, P3061 STEVELS ALN, 1971, RECUEIL, V111, P273 TONEJC A, 1975, APPL CRYSTALLOGR, V8, P375 TROTMANDICKENSO.AF, 1973, COMPREHENSIVE INORGA, V3, P16 TUTTLE JR, 1995, P SOC PHOTO-OPT INS, V2531, P194 YAKAMOTO K, 1991, J SOLID STATE CHEM, V93, P202 NR 29 TC 32 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-0248 J9 J CRYST GROWTH JI J. Cryst. Growth PD MAY PY 1999 VL 203 IS 1-2 BP 113 EP 124 PG 12 SC Crystallography GA 197MA UT ISI:000080367500015 ER PT J AU Villasenor, R Garcia, F TI An experimental study of the effects of asphaltenes on heavy fuel oil droplet combustion SO FUEL LA English DT Article DE asphaltenes; captive droplet technique; oil droplet combustion; ignition time delay ID MICROEXPLOSION; VAPORIZATION; IGNITION AB Experiments of isolated heavy fuel oil droplets containing high asphaltene concentrations were carried out by the captive droplet technique. High-resolution video methods were used to monitor the transients experienced by the burning droplets. The suspended droplets confined in a highly radiative oxidizing environment were exposed to a maximum heating rate of 1000 degrees C/s. Data on size and temperature histories were obtained for different initial droplet diameters. A critical artificial lower bound for ignition time delay was determined by applying classical thermal theory to the monitored temperature histories. The ignition temperatures so predicted were comparable in magnitude to the observed values within experimental uncertainty. The occurrence of disruptive boiling, swelling, splashing and the formation of coke were clearly identified by three characteristic combustion times. Under the experimental conditions to which the droplets were subjected, disruption behavior was found to be attributed to the volatility differential of the high asphaltenic fuels rather than the presence of the suspended fiber. Coking of these asphaltenic fuels was accompanied by a dramatic eruption effect during the last moments of the droplet lifetime when the molecular structure of the cenosphere is molded. Excess burnout time or the ratio of burnout time of a high to a low asphaltenic fuel oil was strongly dependent on the initial droplet diameter. The experimental results strongly indicate that less oxidation time was required for coke particles that were low in asphaltenes. In boiler and furnace operation this means that greater residence times are required to oxidize conospheric residues if the heavy fuel oils have a substantial asphaltene content compared to droplets of the same size but with less aromaticity. (C) 1999 Elsevier Science Ltd. All rights reserved. C1 Washington State Univ, Dept Civil & Environm Engn, Pullman, WA 99163 USA. Inst Invest Elect Sistemas Combust, Cuernavaca 62001, Morelos, Mexico. RP Villasenor, R, Washington State Univ, Dept Civil & Environm Engn, Pullman, WA 99163 USA. CR BAERT RSG, 1993, COMBUST SCI TECHNOL, V90, P125 CHEN M, 1984, 20TH S INT COMB PITT, P1513 CUNNINGHAM ATS, 1989, P ROY SOC LOND A MAT, V423, P233 ESSENHIGH RH, 1989, COMBUST FLAME, V77, P3 GODSAVE GAE, 1952, 4 S INT COMB COMB I, P819 HOTTEL HC, 1955, 5 S INT COMB COMB I, P101 JACQUES MT, 1976, 16TH S INT COMB PITT, P307 KOBAYASI K, 1955, 5 S INT COMB COMB I, P141 LAGE PLC, 1995, COMBUST FLAME, V101, P36 LASHERAS JC, 1980, COMBUST SCI TECHNOL, V22, P195 LASHERAS JC, 1981, 18 S INT COMB COMB I, P293 LIGHTMAN P, 1983, J I ENERGY, V56, P3 MARRONE NJ, 1984, COMBUST SCI TECHNOL, V36, P149 MICHEAL MI, 1967, 11 S INT COMB COMB I, P1027 RUIZ G, 1983, IIE121675I SEFER NR, 1988, AP5826 EPRI SHYU RR, 1972, FUEL, V51, P135 TAKEI M, 1993, COMBUST FLAME, V93, P149 URBAN DL, 1990, 23 S INT COMB COMB I, P1437 URBAN DL, 1992, 24 S INT COMB COMB I, P1357 WANG CH, 1984, COMBUST FLAME, V56, P175 WANG CH, 1985, COMBUST FLAME, V59, P53 WILLIAMS A, 1976, PROG ENERG COMBUST, V2, P167 WILLIAMS A, 1990, COMBUSTION LIQUID FU, V1 YAP LT, 1984, COMBUST SCI TECHNOL, V41, P291 NR 25 TC 14 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0016-2361 J9 FUEL JI Fuel PD JUN PY 1999 VL 78 IS 8 BP 933 EP 944 PG 12 SC Energy & Fuels; Engineering, Chemical GA 197PK UT ISI:000080373900008 ER PT J AU Garcia, VM Nair, MTS Nair, PK TI Formation of a ZnSe : In2O3 heterostructure by air annealing ZnSe-In thin film SO SEMICONDUCTOR SCIENCE AND TECHNOLOGY LA English DT Article ID CHEMICAL-BATH DEPOSITION; DIODE-LASERS; N-TYPE AB A thin film of indium approximately 10 nm thick was deposited by thermal evaporation onto a chemically deposited ZnSe thin film of thickness 0.16 mu m. Annealing the ZnSe-In films in air at 250 to 300 degrees C for 15 min resulted in the formation of a ZnSe-In2O3 heterostructure, The In2O3 layer was approximately 10 nm thick with an average grain diameter of 20 nm, A sheet resistance of 4.5 k Omega/square was observed over the film surface which is attributed to a non-stoichiometric In2O3-x film formed on the surface, with an n-type conductivity of similar to 200 Omega(-1) cm(-1). Annealing at 300 degrees C or for a longer duration at 250 degrees C could reduce this conductivity through improve in the stoichiometry. The optical transmittance of the In2O3 film for the visible and near-infrared region was sc 80%. The underlying ZnSe film showed a direct bandgap of 2.7-2.75 eV, Etching in a dilute HCl solution removed the In2O3 him and revealed a near-intrinsic ZnSe film, showing electrical properties similar to those of the ZnSe films annealed at the same temperature, with sheet resistance similar to 10(13) Ohm/square Applications of the (i)ZnSe-(n)In2O3 heterastructure to the fabrication of photonic devices are suggested. C1 Univ Nacl Autonoma Mexico, Ctr Invest Energia, Dept Solar Energy Mat, Temixco 62580, Morelos, Mexico. RP Garcia, VM, Univ Nacl Autonoma Mexico, Ctr Invest Energia, Dept Solar Energy Mat, Temixco 62580, Morelos, Mexico. CR ARENAS OL, 1997, SEMICOND SCI TECH, V12, P1323 AYLWARD GH, 1974, SI CHEM DATA, P38 BARRETT CS, 1966, STRUCTURE METALS, P155 DONA JM, 1995, J ELECTROCHEM SOC, V142, P764 DUTTA J, 1995, SOL ENERG MAT SOL C, V36, P357 ESTRADA CA, 1994, J ELECTROCHEM SOC, V141, P802 GARCIA VM, 1996, J ELECTROCHEM SOC, V143, P2892 GEORGE PJ, 1995, APPL PHYS LETT, V66, P3624 GRILLO DC, 1993, J ELECTRON MATER, V22, P441 HODES G, 1987, PHYS REV B, V36, P4215 JEON H, 1992, APPL PHYS LETT, V60, P2045 MADELUNG O, 1992, SEMICONDUCTORS OTHER, P26 PARBROOK PJ, 1993, J CRYST GROWTH, V128, P239 TUTTLE JR, 1995, P SOC PHOTO-OPT INS, V2531, P194 ZINGARO RA, 1964, J ELECTROCHEM SOC, V111, P42 NR 15 TC 7 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0268-1242 J9 SEMICOND SCI TECHNOL JI Semicond. Sci. Technol. PD APR PY 1999 VL 14 IS 4 BP 366 EP 372 PG 7 SC Engineering, Electrical & Electronic; Materials Science, Multidisciplinary; Physics, Condensed Matter GA 187ZJ UT ISI:000079818500015 ER PT J AU Zentella, R Mascorro-Gallardo, JO Van Dijck, P Folch-Mallol, J Bonini, B Van Vaeck, C Gaxiola, R Covarrubias, AA Nieto-Sotelo, J Thevelein, JM Iturriaga, G TI A Selaginella lepidophylla trehalose-6-phosphate synthase complements growth and stress-tolerance defects in a yeast tps1 mutant SO PLANT PHYSIOLOGY LA English DT Article ID OSMOREGULATORY TREHALOSE SYNTHESIS; SACCHAROMYCES-CEREVISIAE; ESCHERICHIA-COLI; PHOSPHATASE COMPLEX; WATER-STRESS; GENE; GLUCOSE; PLANTS; GLYCOLYSIS; PROTEINS AB The accumulation of the disaccharide trehalose in anhydrobiotic organisms allows them to survive severe environmental stress. A plant cDNA, SlTPS1, encoding a 109-kD protein, was isolated from the resurrection plant Selaginella lepidophylla, which accumulates high levels of trehalose. Protein-sequence comparison showed that SlTPS1 shares high similarity to trehalose-6-phosphate synthase genes from prokaryotes and eukaryotes. SlTPS1 mRNA was constitutively expressed in S. lepidophylla. DNA gel-blot analysis indicated that SlTPS1 is present as a single-copy gene. Transformation of a Saccharomyces cerevisiae tps1 Delta mutant disrupted in the ScTPS1 gene with S. lepidophylla SlTPS1 restored growth on fermentable sugars and the synthesis of trehalose at high levels. Moreover, the SlTPS1 gene introduced into the tps1 Delta mutant was able to complement both deficiencies: sensitivity to sublethal heat treatment at 39 degrees C and induced thermotolerance at 50 degrees C. The osmosensitive phenotype of the yeast tps1 Delta mutant grown in NaCl and sorbitol was also restored by the SlTPS1 gene. Thus, SITPS1 protein is a functional plant homolog capable of sustaining trehalose biosynthesis and could play a major role in stress tolerance in S. lepidophylla. C1 Univ Nacl Autonoma Mexico, Inst Biotecnol, Dept Biol Mol Plantas, Cuernavaca 62210, Morelos, Mexico. Katholieke Univ Leuven, Lab Mol Celbiol, B-3000 Louvain, Belgium. Katholieke Univ Leuven VIB, B-3000 Louvain, Belgium. RP Iturriaga, G, Univ Nacl Autonoma Mexico, Inst Biotecnol, Dept Biol Mol Plantas, Ave Univ 2001, Cuernavaca 62210, Morelos, Mexico. EM iturri@ibt.unam.mx CR ADAMS RP, 1990, BIOCHEM SYST ECOL, V18, P107 BLAZQUEZ MA, 1998, PLANT J, V13, P685 BURKE MJ, 1985, MEMBRANES METABOLISM, P358 CABIB E, 1958, J BIOL CHEM, V231, P259 CHRISTIANSON TW, 1992, GENE, V110, P119 CLEGG JS, 1965, COMP BIOCH PHYSL, V14, P135 CLEGG JS, 1985, MEMBRANES METABOLISM, P169 COLACO C, 1992, BIO-TECHNOL, V10, P1007 CROWE JH, 1984, SCIENCE, V223, P701 CROWE JH, 1987, BIOCHEM J, V242, P1 CROWE JH, 1992, ANNU REV PHYSIOL, V54, P579 DEVIRGILIO C, 1993, EUR J BIOCHEM, V212, P315 DIVIRGILIO C, 1994, EUR J BIOCHEM, V219, P179 ELBLE R, 1992, BIOTECHNIQUES, V13, P18 ELLIOTT B, 1996, GENETICS, V144, P923 GAFF DF, 1971, SCIENCE, V174, P1033 GARCIA AB, 1997, PLANT PHYSIOL, V115, P159 GIAEVER HM, 1988, J BACTERIOL, V170, P2841 GODDIJN OJM, 1997, PLANT PHYSIOL, V113, P181 HENGGEARONIS R, 1991, J BACTERIOL, V173, P7918 HOHMANN S, 1993, CURR GENET, V23, P281 HOHMANN S, 1996, MOL MICROBIOL, V20, P981 HOUNSA CG, 1998, MICROBIOL-UK 3, V144, P671 KAASEN I, 1994, GENE, V145, P9 LONDESBOROUGH J, 1993, EUR J BIOCHEM, V216, P841 LUYTEN K, 1993, EUR J BIOCHEM, V217, P701 MACKENZIE KF, 1988, J GEN MICROBIOL, V134, P1661 MASCORROGALLARDO JO, 1996, GENE, V172, P169 MULLER J, 1995, PLANT SCI, V112, P1 NEVES MJ, 1994, WORLD J MICROB BIOT, V10, P17 NEVES MJ, 1995, CURR GENET, V27, P110 REINDERS A, 1997, MOL MICROBIOL, V24, P687 SAMBROOK J, 1989, MOL CLONING LAB MANU SERRANO R, 1995, METHOD CELL BIOL, V50, P481 THEVELEIN JM, 1984, MICROBIOL REV, V48, P42 THEVELEIN JM, 1995, TRENDS BIOCHEM SCI, V20, P3 THOMAS BJ, 1989, CELL, V56, P619 THOMPSON JD, 1994, NUCLEIC ACIDS RES, V22, P4673 VANAELST L, 1993, MOL MICROBIOL, V8, P927 VANDERCAMMEN A, 1989, EUR J BIOCHEM, V182, P613 VOGEL G, 1998, PLANT J, V13, P673 WEISBURD S, 1988, SCI NEWS, V133, P107 YANCEY PH, 1982, SCIENCE, V217, P1214 NR 43 TC 41 PU AMER SOC PLANT PHYSIOLOGISTS PI ROCKVILLE PA 15501 MONONA DRIVE, ROCKVILLE, MD 20855 USA SN 0032-0889 J9 PLANT PHYSIOL JI Plant Physiol. PD APR PY 1999 VL 119 IS 4 BP 1473 EP 1482 PG 10 SC Plant Sciences GA 186PJ UT ISI:000079737900035 ER PT J AU Rincon, ME Campos, J Suarez, R TI A comparison of the various thermal treatments of chemically deposited bismuth sulfide thin films and the effect on the structural and electrical properties SO JOURNAL OF PHYSICS AND CHEMISTRY OF SOLIDS LA English DT Article DE chalcogenides; semiconductors; thin films; electrical conductivity ID CONDUCTIVITY ENHANCEMENT; KINETICS AB The physicochemical transformations of chemically precipitated bismuth sulfide powder have been studied by differential scanning calorimetry (DSC) and X-ray diffraction analysis (XRD). The structural changes have been con-elated to the electrical properties of chemically deposited bismuth sulfide thin films annealed at different temperatures (T) and pressures (P-t). Two irreversible exothermic transformations are observed at 210 and 253 degrees C in the powder, which correspond to the crystallization of Bi2S3, and to the crystallization and decomposition of local defects and their reaction to form Bi2S3. As in the case of the precipitate, the conductivity of chemically deposited bismuth sulfide thin films upon annealing is due to the formation of multicomponent phases assisted by further sulfur loss. The complex mechanism that enhances the film conductivity shows a compensating effect between P-t and T. The temperature and pressure regime at which conductive films were obtained with Bi2S3 as the only component of the crystalline phase were: 190 degrees C under vacuum, and 250 degrees C in the P-t range of 10-1000 mbar. Under these conditions, the dark conductivity and photoconductivity of the films are in the range of 10(-2) to 3 Ohm(-1) cm(-1), mainly determined by the charge transport through Bi2S3 crystals. (C) 1999 Elsevier Science Ltd. All rights reserved. C1 Univ Nacl Autonoma Mexico, Ctr Invest Energia, Temixco 62580, Morelos, Mexico. RP Rincon, ME, Univ Nacl Autonoma Mexico, Ctr Invest Energia, Temixco 62580, Morelos, Mexico. CR COTTON FA, 1980, ADV INORG CHEM, P508 DESAI JD, 1995, MATER CHEM PHYS, V41, P98 KALYANASUNDARAM K, 1985, SOL CELLS, V15, P93 NAIR MTS, 1990, SEMICOND SCI TECH, V5, P1225 NAIR PK, 1993, J ELECTROCHEM SOC, V140, P754 RINCON ME, 1996, J PHYS CHEM SOLIDS, V57, P1937 RINCON ME, 1996, J PHYS CHEM SOLIDS, V57, P1947 SILVERMAN MS, 1964, INORG CHEM, V3, P1041 NR 8 TC 8 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0022-3697 J9 J PHYS CHEM SOLIDS JI J. Phys. Chem. Solids PD MAR PY 1999 VL 60 IS 3 BP 385 EP 392 PG 8 SC Chemistry, Multidisciplinary; Physics, Condensed Matter GA 179HD UT ISI:000079320000016 ER PT J AU Gonzalez-Rodriguez, JG Luna-Ramirez, A Martinez-Villafane, A TI Effect of hot corrosion on the creep properties of types 321 and 347 stainless steels SO JOURNAL OF MATERIALS ENGINEERING AND PERFORMANCE LA English DT Article DE creep; hot corrosion; stainless steel type 321H; stainless steel type 347H AB Problems caused by hot corrosion and creep damage on superheater and reheater tubes of power plants using heavy oil as fuel inhibit the continuous service of the boilers and shorten their design lives. The acceleration of hot corrosion attack of boilers is caused by the presence of fuel ash deposits containing V, Na, and S, in the form of Na2SO4 and V2O5, which form low melting point phases. In addition to this, the tubes are exposed to the action of both high stresses and high temperatures, producing a continuous plastic deformation of the tube walls called creep damage, Creep rupture tests were carried out in the temperature range 620 to 670 degrees C in static air in the presence of corrosive environments using 321H and 347H type stainless steels used in superheater and reheater tubes under hot corrosion and creep environments. The corrosive environment includes synthetic Na2SO4, V2O5, and the mixture 80%V2O5-20%Na2SO4. Also, the role of the different elements present in the environments on corrosion was investigated using electronic microscopy and x-ray diffraction techniques. C1 Univ Autonoma Estado Morelos, Fac Ciencias Quim & Ingn, Cuernavaca, Morelos, Mexico. Inst Invest Elect, Dept Equipos Mecan Rotatorios, Temixco 62490, Morelos, Mexico. Ctr Invest Mat Avanzados, Chihuahua 31109, Mexico. RP Gonzalez-Rodriguez, JG, Univ Autonoma Estado Morelos, Fac Ciencias Quim & Ingn, Av Univ 1001, Cuernavaca, Morelos, Mexico. CR AHILA S, 1993, T INDIAN I METALS, V46, P215 KOFSTAD P, 1984, P S HIGH TEMP CORR C, P207 PARKER JD, 1987, CS5500SR EPRI, P3 SURYANARAYANAN V, 1989, MAT SCI ENG A-STRUCT, V112, P107 NR 4 TC 1 PU ASM INTERNATIONAL PI MATERIALS PARK PA SUBSCRIPTIONS SPECIALIST CUSTOMER SERVICE, MATERIALS PARK, OH 44073-0002 USA SN 1059-9495 J9 J MATER ENG PERFORM JI J. Mater. Eng. Perform. PD FEB PY 1999 VL 8 IS 1 BP 91 EP 97 PG 7 SC Materials Science, Multidisciplinary GA 177TL UT ISI:000079227100011 ER PT J AU Villarreal, C Arredondo-Jimenez, JI Rodriguez, MH Ulloa, A TI Colonization of Anopheles pseudopunctipennis from Mexico SO JOURNAL OF THE AMERICAN MOSQUITO CONTROL ASSOCIATION LA English DT Article DE Anopheles pseudopunctipennis; laboratory colony; flashlight plus thermoperiod method; malaria; Mexico AB Two colonies of Anopheles pseudopunctipennis, Tapachula and Abasolo strains, were established under laboratory conditions with a thermoperiod (29 degrees C during the day; 24 degrees C during the night) and artificial dusk. To stimulate mating, a light beam from a flashlight was shone on the cage shortly after lights off. This procedure was repented for the first 6 mosquito generations (parental to F-6) and thereafter light stimulation was unnecessary for mating. The Tapachula colony has been maintained for 24 generations in 24 months, with insemination rates in females >80% since the F-3, and a monthly production of 30,000 pupae since the F-7. Using the same procedure, the Abasolo colony from northeastern Mexico has been maintained for 13 generations in 14 months, with insemination rates of 26-52%. C1 Inst Nacl Salud Publ, Ctr Invest Paludismo, Tapachula 30700, Chiapas, Mexico. Inst Nacl Salud Publ, Ctr Invest Sobre Enfermedades Infeciosas, Cuernavaca 62508, Morelos, Mexico. RP Villarreal, C, Inst Nacl Salud Publ, Ctr Invest Paludismo, Apartado Postal 537, Tapachula 30700, Chiapas, Mexico. CR *WHO, 1975, MAN PRACT ENT MAL 2 BAERG DC, 1971, J MED ENTOMOL, V8, P180 BAKER RH, 1962, MOSQ NEWS, V22, P16 BRUCECHWATT LJ, 1985, ESSENTIAL MALARIOLOG DARSIE RW, 1980, MOSQ NEWS, V40, P194 ESTRADAFRANCO JG, 1993, AM J TROP MED, V49, P746 FERNANDEZSALAS I, 1994, J AM MOSQUITO CONTR, V10, P477 GERBERG EJ, 1994, B AM MOSQ CONTROL AS, V5 MARTINEZPALACIO.A, 1967, MOSQ NEWS, V27, P55 RODRIGUEZ MH, 1989, 4 S NAC ENT MED VET RODRIGUEZPEREZ AA, 1991, J AM MOSQUITO CONTR, V7, P316 WARREN M, 1980, AM J TROP MED HYG, V29, P503 ZAR JH, 1984, BIOSTATISTICAL ANAL NR 13 TC 11 PU AMER MOSQUITO CONTROL ASSN INC PI LAKE CHARLES PA 2200 E PRIEN LAKE RD, LAKE CHARLES, LA 70601 USA SN 8756-971X J9 J AMER MOSQUITO CONTR ASSN JI J. Am. Mosq. Control Assoc. PD DEC PY 1998 VL 14 IS 4 BP 369 EP 372 PG 4 SC Entomology GA 174BE UT ISI:000079013600003 ER PT J AU Siqueiros, J Bonilla, O TI An experimental study of a three-phase, direct-contact heat exchanger SO APPLIED THERMAL ENGINEERING LA English DT Article ID MODEL AB An experimental pilot scale three-phase, direct-contact heat exchanger was constructed and tested. Experiments were performed using normal pentane as the dispersed phase and water as the continuous phase. The inlet water temperatures ranged from 75 to 88 degrees C, and the inlet pentane temperatures varied from 23 to 38 degrees C. The volumetric heat transfer coefficient, hold-up and heat flow-rate are functions of pentane mass flow-rate. For high pentane/water volumetric flow ratios flooding was reached. Before reaching flooding conditions, accumulation of liquid pentane at the top of the active volume was found. The experimental volumetric heat transfer coefficient values are on average 30% greater than those estimated with the correlation previously proposed by Jacobs. (C) 1998 Elsevier Science Ltd. All rights reserved. C1 Inst Invest Elect, Div Energias Alternas & Informat, Unidad Energias No Convenc, Cuernavaca 62490, Morelos, Mexico. RP Siqueiros, J, Inst Invest Elect, Div Energias Alternas & Informat, Unidad Energias No Convenc, Cuernavaca 62490, Morelos, Mexico. CR BOEHM RF, 1985, SERISTR2522678 CORE KL, 1990, AICHE J, V36, P1137 GOODWIN P, 1985, 22 NAT HEAT TRANSF C HEARD CL, 1986, J HEAT RECOV SYST, V6, P185 JACOBS HR, 1980, DIRECT CONTACT BINAR, P413 JACOBS HR, 1988, DIRECT CONTACT HEAT, P343 LETAN R, 1968, AICHE J, V14, P398 LETAN R, 1988, DIRECT CONTACT HEAT, P83 MORI YH, 1991, AICHE J, V37, P539 PLASS SB, 1979, AICHE S SERIES HEAT, V75, P227 RICHARDSON JF, 1954, T I CHEM ENG-LOND, V32, P35 SEETHARAMU KN, 1989, T ASME, V111, P780 SHIMIZU Y, 1988, INT J HEAT MASS TRAN, V31, P1843 SIDEMAN S, 1966, AICHE J, V12, P296 SIQUEIROS J, 1997, 12 C AN TERM MEX DF, P139 SKELLAND AHP, 1974, CAN J CHEM ENG, V52, P732 SMITH RC, 1982, T ASME, V104, P264 SOON A, 1982, J SOLAR ENERGY ENG, V104, P262 SUMMERS SM, 1991, AICHE J, V37, P1673 SURATT WB, 1977, AICHE ASME HEAT TRAN TRADIST L, 1987, INT J HEAT MASS TRAN, V30, P1773 WRIGHT JD, 1981, SERITR6311122R WRIGHT JD, 1982, SERITR2521401 WRIGHT JD, 1988, DIRECT CONTACT HEAT, P299 NR 24 TC 2 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 1359-4311 J9 APPL THERM ENG JI Appl. Therm. Eng. PD MAY PY 1999 VL 19 IS 5 BP 477 EP 493 PG 17 SC Thermodynamics; Energy & Fuels; Engineering, Mechanical; Mechanics GA 172NQ UT ISI:000078931000003 ER PT J AU Barragan, RM Arellano, VM Birkle, P Portugal, E Diaz, G TI Chemical description of spring waters from the Tutupaca and Rio Calientes (Peru) geothermal zones SO INTERNATIONAL JOURNAL OF ENERGY RESEARCH LA English DT Article DE geothermal energy; thermal springs; reservoir temperatures; mixing models; Republic of Peru ID CA AB Analysis of chemical data from 34 spring samples from the Tutupaca and Rio Calientes (Republic of Peru) geothermal zones is presented in this paper. The main objective of the work was to characterize geothermal resources to be exploited in the future The investigated zones were: Tutupaca and Rio Calientes-Ancocollo-Challapalca. Thermal waters from Tutupaca showed low pH values and they were classified as sulphate type waters. Thermal springs from the Rio Calientes zone showed almost neutral pH values and they were classified as sodium chloride type waters with a probably geothermal origin. Reservoir temperatures were estimated and the results indicated that water-rock equilibrium in the hydrothermal system was not completely attained. Taking into account the chemical composition of some equilibrated or 'mature' waters from the Rio Calientes zone, reservoir temperatures in the range of 210-240 degrees C were estimated. Mixing models based on silica, chloride and specific enthalpy of the samples were used to estimate the composition of the reservoir liquid. Isotopic data showed oxygen-18 shift for the waters from Rio Calientes-Ancocollo regarding the waters from Tutupaca tone which were found on the world meteoric line. Copyright (C) 1999 John Wiley & Sons, Ltd. C1 Inst Invest Elect, Unidad Geotermia, Temixco 62490, Morelos, Mexico. RP Barragan, RM, Inst Invest Elect, Unidad Geotermia, Reforma 113,Col Palmira, Temixco 62490, Morelos, Mexico. CR BARRON BA, 1996, J OCCUP REHABIL, V6, P87 BIRKLE P, 1996, ESTUDIO GEOLOGICO ES ELECTROPERU SA, 1994, ESTUDIO GEOVOLCALOGI, P264 FOURNIER RO, 1973, GEOCHIM COSMOCHIM AC, V37, P1255 FOURNIER RO, 1979, GEOCHIM COSMOCHIM AC, V43, P1543 FOURNIER RO, 1979, GEOTHERM RESOUR COUN, V3, P221 FOURNIER RO, 1979, J VOLCANOL GEOTHERM, V5, P1 FOURNIER RO, 1982, GEOTHERMAL RES COUNC, V11, P3 FOURNIER RO, 1992, APPL GEOCHEMISTRY GE, P37 GIGGENBACH WF, 1988, GEOCHIM COSMOCHIM AC, V52, P2749 GIGGENBACH WF, 1991, APPL GEOCHEMISTRY GE, P119 GIGGENBACH WF, 1995, P WORLD GEOTHERMAL C, V2, P995 MERCADO S, 1980, IIEFEG232 NIEVA D, 1987, HEAT RECOVERY SYSTEM, V7, P243 NR 14 TC 0 PU JOHN WILEY & SONS LTD PI W SUSSEX PA BAFFINS LANE CHICHESTER, W SUSSEX PO19 1UD, ENGLAND SN 0363-907X J9 INT J ENERG RES JI Int. J. Energy Res. PD FEB PY 1999 VL 23 IS 2 BP 125 EP 139 PG 15 SC Energy & Fuels; Nuclear Science & Technology GA 165ML UT ISI:000078524900004 ER PT J AU Porcayo-Calderon, J Brito-Figueroa, E Gonzalez-Rodriguez, JG TI Oxidation behaviour of Fe-Si thermal spray coatings SO MATERIALS LETTERS LA English DT Article DE Fe-Si metallic coatings; oxidation; corrosion ID RESISTANCE; ALLOYS AB The oxidation resistance of FexSi metallic coatings, with x = 17, 25, 35, 45 and 75% in weight, have been evaluated in pure O-2, in the temperature range of 600-900 degrees C after exposure for up to 24 h. The substrate was a 304 type stainless steel, and between the alloy and the coating a Ni20Cr coating was used to improve the adhesion of the Si-base. The coatings were applied with a powder flame spraying gun. The Ni-20%Cr thermal spray coating had the lowest oxidation resistance, followed by the FexSi coating. The uncoated 304 type stainless steel had the highest oxidation resistance. The FexSi coatings had a higher oxidation rate than the 304 type stainless steel due to the fact that the coatings had a very high porosity regardless of the content of Si and also to the fact that the diffusion coefficients for Si in Fe-Cr alloys is at least two orders of magnitude lower than that of Cr, so the time required to form a protective SiO2 layer is much longer than the one for Cr2O3. There was no major effect of the Si content in the metallic coatings on their oxidation resistance in the range of temperatures tested here. The Ni-20%Cr has a higher oxidation rate than the uncoated 304 type stainless steel, although the Cr content is very similar in both of them, due to the fact that the Cr diffuses much faster in Fe-Cr than in Ni-Cr alloys, and the solubility and diffusivity of O-2 is higher in Ni-Cr than in Fe-Cr alloys. (C) 1999 Elsevier Science B.V. All rights reserved. C1 Inst Invest Elect, Dept Sistemas Combust, Cuernavaca, Morelos, Mexico. Univ Autonoma Estado Morelos, Fac Ciencias Quim & Ingn, Cuernavaca, Morelos, Mexico. RP Porcayo-Calderon, J, Inst Invest Elect, Dept Sistemas Combust, Apdo Postal 1-475,CP 62001, Cuernavaca, Morelos, Mexico. CR ADACHI T, 1987, OXID MET, V27, P347 ANSARI AA, 1987, MATER SCI ENG, V88, P135 ATKINSON A, 1981, CORROS SCI, V21, P49 ATKINSON A, 1982, CORROS SCI, V22, P87 EVANS HE, 1983, OXID MET, V19, P1 FITZER F, 1981, HIGH TEMPERATURE COR, P604 PORCAYOCALDERON J, 1995, CORROSION 95 ROBERTSON J, 1989, MATER SCI TECH SER, V5, P741 SAUNDERS SRJ, 1989, MATER SCI TECH SER, V5, P780 STOTT FH, 1989, MAT SCI TECHNOLOGY, V5, P34 NR 10 TC 8 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0167-577X J9 MATER LETT JI Mater. Lett. PD JAN PY 1999 VL 38 IS 1 BP 45 EP 53 PG 9 SC Materials Science, Multidisciplinary; Physics, Applied GA 158NG UT ISI:000078121200009 ER PT J AU Hu, H Gomez-Daza, O Banos, L TI Screen printed conductive CuS-poly(acrylic acid) composite coatings SO SOLAR ENERGY MATERIALS AND SOLAR CELLS LA English DT Article DE screen printed coatings; composite materials; electrical properties ID SOLAR CONTROL COATINGS; THIN-FILMS; OPTICAL-PROPERTIES; DEPOSITION AB Copper sulfide (CuS) powder precipitated from two different chemical baths (citrate and triethanolamine baths) was dispersed in a poly(acrylic acid) aqueous solution and the resulting mixtures were screen-printed over glass slides. Compared to the coatings of the same composite materials obtained by casting, the screen-printed coatings show better homogeneity and an improved thermal stability (up to 300 degrees C). Sheet resistances of 50 Omega/square were typical in 20 mu m thick coatings and these values remained stable even after baking in nitrogen or vacuum at 20-300 degrees C. The X-ray diffraction pattern indicates degradation of CuS to Cu1.8S and Cu1.96S, particularly in air-baked samples at 250-300 degrees C. The XRD, TGA and R-square results show CuS(Cit)-PAA samples as superior conductive coatings. (C) 1998 Published by Elsevier Science B.V. All rights reserved. C1 Univ Nacl Autonoma Mexico, Ctr Invest Energia, Temixco 62580, Morelos, Mexico. UNAM, Inst Invest Mat, Mexico City, DF, Mexico. RP Hu, H, Univ Nacl Autonoma Mexico, Ctr Invest Energia, Temixco 62580, Morelos, Mexico. CR AGNIHOTRI OP, 1981, SOLAR SELECTIVE SURF, P115 ESTRADAGASCA CA, 1993, J PHYS D APPL PHYS, V26, P1304 GREENBERG AR, 1977, J POLYM SCI POL CHEM, V15, P2137 HU H, UNPUB HU H, 1996, J MATER RES, V11, P739 HU HL, 1996, SURF COAT TECH, V81, P183 HUANG L, 1995, PHOSPHORUS SULFUR, V105, P175 MATSUMOTO H, 1989, JPN J APPL PHYS, V19, P129 MAYCOCK PD, 1981, PHOTOVALTAICS SUNLIG, P39 NAIR MTS, 1989, SEMICOND SCI TECH, V4, P191 NAIR PK, 1991, J PHYS D APPL PHYS, V24, P441 SEBASTIAN PJ, 1994, SOL ENERG MAT SOL C, V32, P159 NR 12 TC 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0927-0248 J9 SOLAR ENERG MATER SOLAR CELLS JI Sol. Energy Mater. Sol. Cells PD DEC PY 1998 VL 56 IS 1 BP 57 EP 65 PG 9 SC Energy & Fuels; Materials Science, Multidisciplinary GA 158DP UT ISI:000078101000007 ER PT J AU Gonzalez-Rodriguez, JG Salinas-Bravo, VM Martinez-Villafane, A TI Low-temperature stress corrosion cracking of alloy 601 in thiosulfate and chloride solutions SO CORROSION LA English DT Article DE alloy 600; alloy 601; electrochemical potentiokinetic reactivation test; intergranular stress corrosion cracking; Huey test; nitric acid; potassium thiocyanate; slow strain rate testing; sodium chloride; sodium thiosulfate; sulfuric acid ID PITTING CORROSION; INCONEL 600 AB The stress corrosion cracking (SCC) susceptibility of unsensitized and sensitized alloy 601 (UNS N06601) was studied in sodium thiosulfate (Na2S2O3) and sodium chloride (NaCl) solutions using slow strain rate testing (SSRT). Specimens were tested in the as-received condition (mill-annealed) after solution annealing at 1,050 degrees C for 30 min and after solution annealing and sensitizing for 2, 5, 24, or 72 h at 700 degrees for 30 min. Environments included Na2S2O3 and NaCl at different concentrations ranging from 0.01 M to 1.0 M at 25 degrees C and 95 degrees C. Double-loop electrochemical potentiokinetic reactivation (DL-EPR) tests in 0.01 M sulfuric acid (H2SO4) + 0.001 M potassium thiocyanate (KSCN) and immersion tests in boiling 25% nitric acid (HNO3) solution were used to evaluate the effect of heat treatment on the degree of sensitization (DOS) and on intergranular corrosion (IGC) of alloy 601. In all environments tested, the unsensitized alloy was immune to SCC and showed only ductile failure. The alloy sensitized for 24 h showed the highest degree of susceptibility to SCC in 0.1 M Na2S2O3, followed by the alloys sensitized for 72, 5, and 2 h, followed by the as-received and solution-annealed alloys. Except for the of her times of sensitization, ductility for the specimen sensitized for 24 h was always lower at 25 degrees C than at 95 degrees C. The modified Huey and the DL-EPR tests also revealed the highest susceptibility to IGC for specimens sensitized for 24 h. This susceptibility did not change as Na2S2O3 concentration decreased from 0.5 M to 0.01 M, but ductility decreased as solution pH was increased from 3 to 7. Addition of NaCl to Na2S2O3 did not have a clear effect on susceptibility to SCC of the sensitized alloy since ductility sometimes increased but at other times decreased. C1 UAEM, Fac Ciencias Quim & Ingn, Cuernavaca, Morelos, Mexico. IIE, Cuernavaca, Morelos, Mexico. CIMAV, Complejo Ind, Chihuahua, Mexico. RP Gonzalez-Rodriguez, JG, UAEM, Fac Ciencias Quim & Ingn, Av Univ 1001,CP 6225,Col Chamilpa, Cuernavaca, Morelos, Mexico. CR BANDY R, 1983, CORROS SCI, V23, P995 CLARKE WL, 1978, ASTM STP, V656, P99 GONZALEZRODRIGU.JG, 1998, MAT CHEM PHYS, V56 HO JT, 1992, CORROSION, V48, P147 LECKIE HP, 1966, J ELECTROCHEM SOC, V113, P1262 NEWMAN RC, 1983, CORROSION, V39, P387 PARK JR, 1985, CORROSION, V41, P665 SKYES JF, 1985, NP3905 EPRI TOTSUKA N, 1987, CORROSION, V43, P734 TSAI MC, 1993, CORROS SCI, V34, P741 TSAI WT, 1989, MAT SCI ENG A-STRUCT, V118, P121 TSAI WT, 1994, CORROSION, V50, P98 NR 12 TC 0 PU NATL ASSN CORROSION ENG PI HOUSTON PA 1440 SOUTH CREEK DRIVE, HOUSTON, TX 77084-4906 USA SN 0010-9312 J9 CORROSION JI Corrosion PD JAN PY 1999 VL 55 IS 1 BP 38 EP 44 PG 7 SC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering GA 157BJ UT ISI:000078038900006 ER PT J AU Maytorena, JA Lopez-Bastidas, C Mochan, WL TI Theory of 45 degrees reflectometry from metal surfaces SO PHYSICA STATUS SOLIDI A-APPLIED RESEARCH LA English DT Article ID AG SINGLE-CRYSTALS; PLASMON DISPERSION; MODES; ANISOTROPY; AG(110) AB The use of optical spectroscopies to study surfaces is hindered by the difficulty of disentangling bulk and surface contributions to the signal. According to Fresnel formulae, the a and p reflectances R of a semi-infinite system obey the simple relation Delta = R-s(2) - R-p = 0 when the incidence angle is 45 degrees. Deviations from this result can be related to microscopic surface contributions to R. In this paper we study theoretically Delta for metal surfaces. For a semi-infinite nat jellium we obtain the contributions to Delta from electronic excitations at the surface. To explore Delta for non-jellium conductors, we apply a 'Swiss cheese' model to different surfaces of Ag. C1 Univ Nacl Autonoma Mexico, Inst Fis, Cuernavaca 62251, Morelos, Mexico. Univ Autonoma Estado Morelos, Fac Ciencias, Cuernavaca 62210, Morelos, Mexico. RP Maytorena, JA, Univ Nacl Autonoma Mexico, Inst Fis, Apartado Postal 48-3, Cuernavaca 62251, Morelos, Mexico. CR BLECKMANN L, 1996, SURF SCI, V351, P277 BORENSZTEIN Y, 1993, PHYS REV LETT, V71, P2334 FEIBELMAN PJ, 1982, PROG SURF SCI, V12, P287 FEIBELMAN PJ, 1989, PHYS REV B, V40, P2752 JOHNSON PB, 1972, PHYS REV B, V6, P4370 LIEBSCH A, 1987, PHYS REV B, V36, P7378 LIEBSCH A, 1993, PHYS REV LETT, V71, P145 LIEBSCH A, 1997, ELECT EXCITATIONS ME LOPEZBASTIDAS C, UNPUB MADRIGALMELCHOR J, 1997, APPL PHYS LETT, V71, P69 MOCHAN WL, 1983, PHYS REV B, V27, P771 ROCCA M, 1991, PHYS REV LETT, V67, P3197 ROCCA M, 1992, PHYS REV LETT, V69, P2122 TARRIBA J, 1992, PHYS REV B, V46, P12902 TSUEI KD, 1990, PHYS REV LETT, V64, P44 TSUEI KD, 1991, SURF SCI, V247, P302 NR 16 TC 6 PU WILEY-V C H VERLAG GMBH PI BERLIN PA MUHLENSTRASSE 33-34, D-13187 BERLIN, GERMANY SN 0031-8965 J9 PHYS STATUS SOLIDI A-APPL RES JI Phys. Status Solidi A-Appl. Res. PD DEC 16 PY 1998 VL 170 IS 2 BP 337 EP 342 PG 6 SC Materials Science, Multidisciplinary; Physics, Applied; Physics, Condensed Matter GA 154AP UT ISI:000077866100023 ER PT J AU Martinez, L Amaya, M Porcayo-Calderon, J Lavernia, EJ TI High-temperature electrochemical testing of spray atomized and deposited iron aluminides alloyed with boron and reinforced with alumina particulate SO MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING LA English DT Article DE iron aluminides; corrosion current density; molten salt temperature; electrochemical testing ID MECHANICAL-PROPERTIES; CORROSION; MICROSTRUCTURE; COMPOSITES; FRACTURE; OXYGEN; NA2SO4; MELTS; FEAL AB The corrosion behavior of FeAl40 at.%, FeAl40 + 0.1 at.% B and FeAl40 + 0.1 at.% B + 10 at.% Al2O3 in a mixture of molten salts of 80% V2O5 + 20% Na2SO4 (wt.%) from 600 degrees C to 900 degrees C was studied using a potentiodynamic polarization technique. Experiments were conducted in a typical three-electrode cell immersed in the fused salt. Curves of corrosion current density (I-corr) as a function of molten salt temperature were obtained and discussed in terms of the passive layer and corrosion products formed during the electrochemical tests. The corrosion resistance of the FeAl40 + 0.1 at.% B + 10 at.% Al2O3 samples was superior at all temperatures in the interval between 600 degrees C and 900 degrees C. It is apparent that the alumina is playing an important role in corrosion protection. The log i vs. potential polarization curves indicate that corrosion in the FeAl40 at.% and FeAl40 + 0.1 at.% B samples may be associated with the formation and spalling of oxide layers rich in vanadium. (C) 1998 Elsevier Science S.A. All rights reserved. C1 UNAM, Inst Fis, Cuernavaca 62251, Morelos, Mexico. Inst Invest Elect, Temixco 62490, Morelos, Mexico. Univ Calif Irvine, Chem & Biochem Engn & Mat Sci Dept, Irvine, CA 92697 USA. RP Martinez, L, UNAM, Inst Fis, AP 48-3, Cuernavaca 62251, Morelos, Mexico. CR *ASTM, 1973, 172 ASTM G, P626 BAKER I, 1991, ACTA METALL MATER, V39, P1637 BAKER I, 1994, S P PROC PROT APPL I, P101 BALIGIDAD RG, 1997, MAT SCI ENG A-STRUCT, V230, P188 CORBETT RA, 1995, CORROSION TESTS STAN, P98 CUNNINGHAM GW, 1956, CORROSION, V12, T389 DRAPER SL, 1990, J MATER RES, V5, P1976 GAYDOSH DJ, 1992, MAT SCI ENG A-STRUCT, V150, P7 GEORGE EP, 1991, SCRIPTA METALL MATER, V25, P1259 GREENERT WJ, 1962, CORROSION, V18, T57 HWANG S, 1989, CORROS SCI, V45, P993 LI B, 1997, MAT SCI ENG A-STRUCT, V237, P207 LIANG X, 1994, METALL MATER TRANS A, V25, P2341 LONGANAVA Y, 1996, CORROSION, V52, P680 MADSEN BW, 1991, S P WEAR CORR INT LI, P49 MANSFELD F, 1988, CORROSION, V44, P856 MARTINEZ L, 1997, J MATER SYNTH PROCES, V5, P65 MARTINEZ L, 1997, S P 7 INT C CREEP FR, P395 MITTELSTADT R, 1990, METALL TRANS B, V21, P111 NAGY Z, 1993, MOD ASPECT ELECTROC, P135 OTERO E, 1992, CORROS SCI, V33, P1747 PARDO A, 1993, REV METAL, V29, P300 POCCI D, 1994, S P PROC PROP APPL I, P19 PORCAYOCALDERON J, 1998, THESIS UNAM MEXICO, P121 RAPP RA, 1989, SELECTED TOPICS HIGH, P291 RATZERSCHEIBE HJ, 1996, 4 INT S HIGH TEMP CO SCHNEIBEL JH, 1992, MAT SCI ENG A-STRUCT, V153, P684 SCHNEIBEL KJH, 1994, S P PROC PROP APPL I, P329 SCULLY JR, 1995, CORROSION TESTS STAN, P75 SHI DZ, 1987, HIGH TEMPERATURE MAT, V4, P1 SIKKA VK, 1994, S P PROC PROP APPL I, P3 SMALL NJH, 1963, INT C MECH CORR FUEL, P238 SMIALEK JL, 1989, S P OX HIGH TEMP INT, P83 SMITH GD, 1995, CORROSION TESTS STAN, P149 SUBRAMANIAN R, 1996, SCRIPTA MATER, V35, P583 TORTORELLI PF, 1994, S P PROC PROP APPL I, P257 WEBB G, 1994, S P FAT FRACT ORD IN, V1, P103 ZENG XL, 1995, METALL MATER TRANS A, V26, P817 ZHANG J, 1994, ACTA METALL MATER, V42, P395 ZHENG XJ, 1995, J ELECTROCHEM SOC, V142, P142 NR 40 TC 5 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0921-5093 J9 MATER SCI ENG A-STRUCT MATER JI Mater. Sci. Eng. A-Struct. Mater. Prop. Microstruct. Process. PD DEC 31 PY 1998 VL 258 IS 1-2 BP 306 EP 312 PG 7 SC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary GA 153XA UT ISI:000077857500042 ER PT J AU Rosales, MI Cuautle, MP Castano, VM TI Microstructure and magnetic properties of Ni-Zn ferrites SO JOURNAL OF MATERIALS SCIENCE LA English DT Article ID NICKEL FERRITES AB Ni-Zn ferrites were prepared in air by using the conventional ceramic powder methodology. The compositions analysed belong to the type NixZn1-xFe2O4 ferrites, with x ranging from 0.3-0.4. Copper wire was coiled round the specimens, previously pressed to a toroidal shape, to characterize their magnetic properties as a function of the frequency of the applied electric field. Powder X-ray diffraction, scanning electron microscopy and microanalysis, and the magnetic susceptibility of the ferrites, were studied, indicating that the highest permeability is achieved at the composition x=0.3, a result which is correlated to the microstructural characterization. The Curie temperature was also determined to range from 60-130 degrees C, depending on the specific composition. (C) 1998 Kluwer Academic Publishers. C1 Inst Investigac Elect, Dept Mat, Cuernavaca 62001, Morelos, Mexico. Univ Nacl Autonoma Mexico, Inst Fis, Mexico City 01000, DF, Mexico. RP Rosales, MI, Inst Investigac Elect, Dept Mat, Apartado Postal 1-475, Cuernavaca 62001, Morelos, Mexico. CR AGUILARSAHAGUN G, 1994, J APPL PHYS 2B, V75, P7000 CEDILLO E, 1980, J PHYS E, V13, P383 FISCHER S, 1992, CERAM INT, V18, P317 GIERALTOWSKI J, 1977, IEEE T MAGN, V13, P1357 GLOBUS A, 1977, P J PHYS, P38 GUYOT M, 1982, J MAGN MAGN MATER, V27, P202 HARRIS VG, 1995, IEEE T MAGN 2, V31, P3473 IRVINE JTS, 1990, SOLID STATE IONICS 1, V40, P220 KOMARNENI S, 1988, J AM CERAM SOC, V71, C26 MAKINO A, 1992, J JPN SOC POWDER POW, V39, P129 OLIVER CG, 1995, IEEE T MAG, P3982 PURI RK, 1983, J PHYS CHEM SOLIDS, V44, P655 ROSALES MI, 1995, J MATER SCI, V30, P4446 ROSALES MI, 1995, THESIS UNAM MEXICO C ROSALES MI, 1997, J MAT SCI ENG B, V49, P221 SCHLOEMANN E, 1995, IEEE T MAGN, V31, P3470 STICKLAND FG, 1963, J PHYS CHEM-US, V67, P2504 TSENG TY, 1989, IEEE T MAGN, V25, P4405 VALENZUELA R, 1980, J MATER SCI, V15, P3173 VARSHNEY U, 1981, FERRITES P ICF, V3, P207 VARSHNEY U, 1989, IEEE T MAGN, V25, P3109 YAMAMOTO Y, 1994, J MAGN MAGN MATER, V133, P500 ZAPOROZHETS VV, 1986, FIZ MET METALLOVED, V61, P192 NR 23 TC 3 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0022-2461 J9 J MATER SCI JI J. Mater. Sci. PD JUL 15 PY 1998 VL 33 IS 14 BP 3665 EP 3669 PG 5 SC Materials Science, Multidisciplinary GA 149DY UT ISI:000077590900023 ER PT J AU Albarran, JL Lopez, HF Martinez, L TI Crack growth in a welded microalloyed steel under sulfide stress cracking conditions SO JOURNAL OF MATERIALS ENGINEERING AND PERFORMANCE LA English DT Article DE crack formation; microalloyed steel; microstructure; sour gas environment; stress-corrosion cracking ID MICROSTRUCTURE AB In this work, the hydrogen sulfide stress-corrosion cracking (SSC) susceptibility of a welded API X-80 pipeline was investigated, For this purpose, steel welding was carried out normal to the rolling direction using a 60 degrees single V-joint design. After welding, compact modified-wedge opening loading (M-WOL) fracture mechanics specimens were machined and loaded to an applied stress intensity factor, K-I, of 27 to 53 MPa root m. This was followed by specimen exposure to H2S saturated synthetic seawater. Each of the M-WOL specimens contained the typical microstructures developed during welding, such as the weld metal (WM), base metal (BM), and heat affected zone (HAZ). No attempt was made to establish a unique K-ISCC for crack arrest because its significance was not clear. Qualitatively, the experimental outcome indicated that in mode I loading under a K-I of 40.3 MPa root m only the base metal region underwent SSC. Apparently, active anodic dissolution of the crack tip started the growth process, but it was followed by a transition to hydrogen induced cracking, At an applied K-I of 55 MPa root m and under similar exposure times, crack growth in the base metal was discontinuous and tended to follow the grain boundaries. Moreover, the HAZ exhibited the least SSC susceptibility as inferred from the relatively short crack propagation lengths (0.829 mm), In this case, it was found that the crack path was highly tortuous due to the presence of acicular ferrite and a refined grain structure, The most SSC susceptible condition was found in the weld metal where crack lengths of up to 4.2 mm developed. In this case, the presence of a relatively coarse dendritic structure coupled with interdendritic segregation provided a weak path for crack propagation. C1 UNAM, Inst Fis, Lab Cuernavaca, Cuernavaca, Morelos, Mexico. Univ Wisconsin, Coll Engn & Appl Sci, Dept Mat, Milwaukee, WI 53201 USA. RP Albarran, JL, UNAM, Inst Fis, Lab Cuernavaca, Apdo Postal 48-3,CP 62251, Cuernavaca, Morelos, Mexico. EM hlopez@csd.uwm.edu CR *API, 1988, 1104 API ALBARRAN JL, 1998, SCRIPTA MATER, V38, P749 BIRNBAUM HK, 1990, ENV INDUCED CRACKING, P21 BUIST H, 1992, TEST METHODS MAT REQ, V2 CHRISTENSEN C, 1987, CORROS SCI, V27, P1137 DEANS WF, 1979, J TEST EVAL, V7, P147 FRASER FW, 1982, WELD J, V61, S112 LOPEZ HF, IN PRESS METALL MA A LOPEZ HF, 1996, METALL MATER TRANS A, V27, P3601 MARGOTMARETTE H, 1987, CORROS SCI, V27, P1009 NAKAI Y, 1979, T ISIJ, V19, P401 NOVAK SR, 1969, J MATER, V4, P701 ONSOIEN MI, 1990, WELD J, V69, P45 PARKINS RN, 1969, FUNDAMENTAL ASPECTS, P361 PARKINS RN, 1970, CORROSION PARKINS RN, 1988, MAT SCI ENG A-STRUCT, V103, P143 SMITH NJ, 1989, WELD J, V68, S112 SYKES JM, 1993, JOM-J MIN MET MAT S, V45, P31 TRESSEDER RS, 1977, STRESS CORROSION CRA, P147 NR 19 TC 0 PU ASM INTERNATIONAL PI MATERIALS PARK PA SUBSCRIPTIONS SPECIALIST CUSTOMER SERVICE, MATERIALS PARK, OH 44073-0002 USA SN 1059-9495 J9 J MATER ENG PERFORM JI J. Mater. Eng. Perform. PD DEC PY 1998 VL 7 IS 6 BP 777 EP 783 PG 7 SC Materials Science, Multidisciplinary GA 151PV UT ISI:000077730400011 ER PT J AU Alvarez, G Flores, JJ Estrada, CA TI The thermal response of laminated glass with solar control coating SO JOURNAL OF PHYSICS D-APPLIED PHYSICS LA English DT Article AB A transient one-dimensional mathematical model allowing the prediction of the thermal performance of laminated glazing with and without chemically deposited solar control coating and its experimental Verification are presented. A normal laminated glass is composed of two 3 mm glass sheets with a thin polymer layer between them. For the experimental verification, the coating used was a thin film of CuxS added between the polymer layer and one of the glass sheets. A constant normal incidence of air mass 2 solar radiation was assumed. Conductive heat transfer within the glass sheets and convective and radiative heat transfer through the inside and outside are considered. Using the optical properties of glass, polymer and solar control coating, the redistribution of the absorbed component of the solar radiation and the shading coefficient (SC) are calculated as functions of the convective heat-transfer coefficient for the outside (h(o)). Variations of the theoretical inside glass temperature (T-g1) for h(o) and SC for the solar absorptance (a) of the film varying from 0 to 0.9 are presented. For the array with the highest solar absorptance of the solar control coating (alpha = 0.9), the decrease in T-g1 was from 49 down to 27 degrees C, a temperature drop of 22 degrees C as h(o) increases from 5 to 100 W m(-2) K-1. The SC for the array with alpha = 0 is almost constant with h(o) and close to unity, whereas for the array with alpha = 0.9, the SG drops by 62% from 0.58 to 0.22 as h(o) increases. C1 Ctr Nacl Invest & Desarrollo Tecnol, DGIT, SEP, Cuernavaca 62050, Morelos, Mexico. UNAM, Ctr Invest Energia, Temixco 62580, Morelos, Mexico. RP Alvarez, G, Ctr Nacl Invest & Desarrollo Tecnol, DGIT, SEP, Apdo Postal 5-164, Cuernavaca 62050, Morelos, Mexico. CR *AM SOC HEAT REFR, 1977, ASHRAE HDB FUND ARASTEH DK, 1989, ASHRAE T 2, V95, P755 DUFFIE JA, 1991, SOLAR ENG THERMAL PR ESTRADAGASCA CA, 1993, J PHYS D APPL PHYS, V26, P1304 ESTRADAGASCA CA, 1993, RENEW ENERG, V3, P683 KARLSSON T, 1988, INT J ENERG RES, V12, P23 KISS LI, 1975, J ENERGY CONSERVATIO, V2, P883 NAIR MTS, 1991, J PHYS D APPL PHYS, V24, P450 NAIR PK, 1997, P SOC PHOTO-OPT INS, V3138, P197 WATMUFF JH, 1977, COMPLES, V2, P56 NR 10 TC 6 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0022-3727 J9 J PHYS-D-APPL PHYS JI J. Phys. D-Appl. Phys. PD NOV 7 PY 1998 VL 31 IS 21 BP 3057 EP 3065 PG 9 SC Physics, Applied GA 141XT UT ISI:000077170100012 ER PT J AU Chellapandian, M Larios, C Sanchez-Gonzalez, M Lopez-Munguia, A TI Production and properties of a dextransucrase from Leuconostoc mesenteroides IBT-PQ isolated from 'pulque', a traditional Aztec alcoholic beverage SO JOURNAL OF INDUSTRIAL MICROBIOLOGY & BIOTECHNOLOGY LA English DT Article DE dextransucrase; Leuconostoc mesenteroides; pulque; glucosyltransferase ID NRRL B-1299; STREPTOCOCCUS-MUTANS; GLUCOSYLTRANSFERASE; PURIFICATION; LINKAGES; B-1355 AB Dextransucrase was produced from a Leuconostoc mesenteroides isolated from pulque, a traditional Aztec alcoholic beverage produced from agave juice containing sucrose as the main carbon source. Almost all the dextransucrase activity (87%) was associated with the cells, and was unusually high (1.04 U mg(-1) of cells). The culture medium composition was optimized through a Box-Behnken method resulting in a process yielding 2.2 U ml(-1) of insoluble glucosyltransferase activity. The enzyme had a molecular weight of 166 kDa, Optimal temperature was 35 degrees C with a half-life of 137 min at the same temperature. As with dextransucrase from the industrial strain L. mesenteroides NRRL B-512F, the enzyme showed Michaelis-Menten kinetic behavior with excess substrate inhibition (K-m and K-i values of 0.026 M and 1.23 M respectively); produced soluble linear dextran with glucose molecules linked mainly in alpha(1-6) with branching in alpha(1-3) in a proportion of 4:1 as shown by NMR studies; and produced a high yield of isomalto-oligosaccharides in the presence of maltose. C1 UNAM, Inst Biotecnol, Cuernavaca 62271, Morelos, Mexico. RP Lopez-Munguia, A, UNAM, Inst Biotecnol, Apdo Postal 510-3, Cuernavaca 62271, Morelos, Mexico. CR BOX GEP, 1960, TECHNOMETRICS, V2, P455 COTE GL, 1982, CARBOHYD RES, V101, P57 DOLS M, 1997, ENZYME MICROB TECH, V20, P523 GARCIAGARIBAY M, 1993, BIOTECNOLOGIA ALIMEN, P301 HAMADA S, 1989, J GEN MICROBIOL, V135, P335 KIM D, 1995, ENZYME MICROB TECH, V17, P689 KOBAYASHI M, 1975, BIOCHIM BIOPHYS ACTA, V397, P69 KOBAYASHI M, 1980, BIOCHIM BIOPHYS ACTA, V614, P46 LAEMMLI UK, 1970, NATURE, V227, P680 LOPEZMUNGUIA A, 1993, ENZYME MICROB TECH, V15, P77 LOWRY OH, 1951, J BIOL CHEM, V193, P165 MARTINEZESPINDO.JP, 1985, BIOTECHNOL LETT, V7, P483 MONCHOIS V, 1996, GENE, V182, P23 MONSAN P, 1987, METHOD ENZYMOL, V136, P239 REMAUDSIMEON M, 1994, APPL BIOCHEM BIOTECH, V44, P101 SEYMOUR FR, 1977, CARBOHYD RES, V53, P153 SEYMOUR FR, 1980, CARBOHYD RES, V81, P105 SEYMOUR FR, 1980, CARBOHYD RES, V84, P187 STEINKRAUS KH, 1996, HDB INDIGENOUS FERME, P389 SUMNER JB, 1935, J BIOL CHEM, V108, P51 TSUCHIYA HM, 1952, J BACTERIOL, V64, P521 WILLEMOT RM, 1993, B512F NRRL NR 22 TC 0 PU STOCKTON PRESS PI BASINGSTOKE PA HOUNDMILLS, BASINGSTOKE RG21 6XS, HAMPSHIRE, ENGLAND SN 1367-5435 J9 J IND MICROBIOL BIOTECHNOL JI J. Ind. Microbiol. Biotechnol. PD JUL-AUG PY 1998 VL 21 IS 1-2 BP 51 EP 56 PG 6 SC Biotechnology & Applied Microbiology GA 139AP UT ISI:000077005500010 ER PT J AU Nair, MTS Guerrero, L Nair, PK TI Conversion of chemically deposited CuS thin films to Cu1.8S and Cu1.96S by annealing SO SEMICONDUCTOR SCIENCE AND TECHNOLOGY LA English DT Article ID SULFIDE AB Thin films of copper sulphide with thickness up to 0.5 mu m were deposited at 70 degrees C on glass substrates from a solution containing copper(II) chloride, sodium thiosulphate and dimethylthiourea. As prepared and after annealing at 200 degrees C in N-2 (100 millitorr), these films showed x-ray diffraction patterns matching that of the mineral covellite (CuS). Annealing the films for 1 h each at 300 degrees C and 400 degrees C in nitrogen resulted in their conversion to Cu1.8S (digenite) and Cu1.96S (chalcocite), respectively. The reduction in sulphur content of the films is evident in the x-ray florescence spectra. The sheet resistance of the films varied with annealing temperature. For a film of 0.5 mu m thickness, the observed sheet resistance values are: 180 Ohm/square (as prepared), 6 Ohm/square (200 degrees C), 17 Ohm/square (300 degrees C) and 30 Ohm/square (400 degrees C). The low sheet resistance (and thus the high conductivity, 10(3) Ohm(-1) cm(-1)) leads to a high near-infrared reflectance for the films, 65% (CuS) and 40% (Cu1.96S), at a wavelength of 2500 nm. Analyses of the optical band gap of the films indicate an indirect gap of 1.55 eV for CuS and Cu1.8S and 1.4 eV for Cu1.96S. C1 Univ Nacl Autonoma Mexico, Ctr Invest Energia, Dept Solar Energy Mat, Temixco 62580, Morelos, Mexico. RP Nair, MTS, Univ Nacl Autonoma Mexico, Ctr Invest Energia, Dept Solar Energy Mat, Temixco 62580, Morelos, Mexico. CR AYLWARD GH, 1974, SI CHEM DATA, P34 BARRETT CS, 1966, STRUCTURE METALS, P155 BHATTACHARYA RN, 1981, B MATER SCI, V3, P403 BOER KW, 1977, PHYS STATUS SOLIDI, V40, P355 CHOPRA KL, 1982, PHYS THIN FILMS, V12, P201 COTTON FA, 1980, ADV INORG CHEM, P801 COUVE S, 1973, THIN SOLID FILMS, V15, P223 FAHRENBRUCH AL, 1983, FUNDAMENTALS SOLAR C, P229 GROZDANOV I, 1994, SEMICOND SCI TECH, V9, P1234 HODES G, 1987, PHYS REV B, V36, P4215 KOCMAN V, 1973, ACTA CRYSTALLOGR B, V29, P2528 LIDE DR, 1995, HDB CHEM PHYSICS, P12 LOFERSKI JJ, 1979, SOLAR ENERGY MATER, V1, P157 LOKHANDE CD, 1991, MATER CHEM PHYS, V27, P1 MADELUNG O, 1992, SEMICONDUCTORS OTHER, P12 MISHO RH, 1992, SOL ENERG MAT SOL C, V27, P335 NAIR MTS, 1989, SEMICOND SCI TECH, V4, P191 NAIR MTS, 1998, J ELECTROCHEM SOC, V145, P2113 NAIR PK, 1991, J PHYS D APPL PHYS, V24, P441 NAIR PK, 1991, P SOC PHOTO-OPT INS, V1485, P228 NAIR PK, 1993, J ELECTROCHEM SOC, V140, P754 NAIR PK, 1997, J MATER RES, V12, P651 OKAMOTO K, 1973, JPN J APPL PHYS, V12, P1130 ORTON JW, 1982, J APPL PHYS, V53, P1602 RANDHAWA HS, 1982, SOL ENERG MATER, V6, P445 REYNOLDS DC, 1954, PHYS REV, V96, P533 SAVELLI M, 1979, TOP APPL PHYS, V31, P213 TROTMANDICKENSO.AF, 1973, COMPREHENSIVE INORGA, V3, P16 NR 28 TC 30 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0268-1242 J9 SEMICOND SCI TECHNOL JI Semicond. Sci. Technol. PD OCT PY 1998 VL 13 IS 10 BP 1164 EP 1169 PG 6 SC Engineering, Electrical & Electronic; Materials Science, Multidisciplinary; Physics, Condensed Matter GA 129HY UT ISI:000076458800019 ER PT J AU Cruz, MEG de Gives, PM Romero, HQ TI Comparison of the trapping ability of Arthrobotrys robusta and Monacrosporium gephyropagum on infective larvae of Strongyloides papillosus SO JOURNAL OF HELMINTHOLOGY LA English DT Article ID FUNGUS DUDDINGTONIA-FLAGRANS; NEMATODE-DESTROYING FUNGUS; PLANT-PARASITIC NEMATODES; SHEEP FECAL CULTURES; BIOLOGICAL-CONTROL; HAEMONCHUS-CONTORTUS; PREDACIOUS FUNGUS; NEMATOPHAGOUS FUNGI; TRICHOSTRONGYLE INFECTIONS; OLIGOSPORA HYPHOMYCETALES AB In an in vitro trial, the trapping ability of Arthrobotrys robusta and Monacrosporium gephyropagum against Strongyloides papillosus infective larvae on corn meal agar plates, was evaluated after seven days of interaction at 25 degrees C. Monacrosporium gephyropagum trapped 93.1% of the larvae whereas A. robusta trapped only 32.3%. Variability in the capture of S. papillosus infective lan ae by both trapping fungi is discussed. C1 SAGAR, Proyecto Control Biol, Ctr Nacl Invest Parasitol Vet, Inst Nacl Invest Forestales & Agropecuarias, Jiutepec 62500, Morelos, Mexico. Natl Autonomous Univ Mexico, Fac Med Vet & Zootecnia, Dept Parasitol, Mexico City 04510, DF, Mexico. RP de Gives, PM, AFRC, Inst Arable Crops Res, Dept Entomol & Nematol, Harpenden AL5 2JQ, Herts, England. EM pedro.mendoza@bbsrc.ac.uk CR *GENST 5 COMM, 1993, GENST 5 REL 3 REF MA *WHO, 1996, WHO TECHN REP SER, V864 BARRON GL, 1977, NEMATODE DESTROYING BELDER ED, 1994, NEMATOLOGICA, V40, P423 BLUTHGEN A, 1997, INT DAIRY FEDERATION, V9701, P35 CAMPOS RR, 1992, VET MEXICO, V23, P51 CAYROL JC, 1978, REV HORTICOLE, V184, P23 CHARLES TP, 1996, INT J PARASITOL, V26, P509 COOKE RC, 1964, T BRIT MYCOL SOC, V47, P61 DIJKSTERHUIS J, 1994, ADV MICROBIOL PHYSL, V36, P112 DOMSH HK, 1980, COMPENDIUM SOIL FUNG, V1 DUDDINGTON CL, 1951, T BRIT MYCOLOGICAL S, V34, P598 GALLIARD H, 1967, HELMINTHOL ABSTR, V36, P247 GALPER S, 1995, NEMATOLOGICA, V41, P130 GITHIGIA SM, 1997, INT J PARASITOL, V27, P931 GRONVOLD J, 1985, J HELMINTHOL, V59, P119 GRONVOLD J, 1987, J HELMINTHOL, V61, P65 GRONVOLD J, 1988, J HELMINTHOL, V62, P271 GRONVOLD J, 1993, VET PARASITOL, V48, P311 GRONVOLD J, 1996, J HELMINTHOL, V70, P281 HASHMI HA, 1989, PARASITOL TODAY, V5, P28 HENRIKSEN SA, 1997, ACTA VET SCAND, V38, P175 HERD R, 1993, VET PARASITOL, V48, P1 LARSEN M, 1991, J HELMINTHOL, V65, P193 LARSEN M, 1992, J HELMINTHOL, V66, P137 LARSEN M, 1995, VET PARASITOL, V60, P321 LLERANDI JR, 1998, IN PRESS J HELMINTHO LYSEK G, 1981, PLANTA, V152, P50 MENDOZADEGIVES P, 1992, VET PARASITOL, V41, P101 MENDOZADEGIVES P, 1994, J HELMINTHOL, V68, P223 MENDOZADEGIVES P, 1994, VET PARASITOL, V55, P197 MORGAN M, 1997, PARASITOLOGY 3, V115, P303 NANSEN P, 1986, P HELM SOC WASH, V53, P237 NANSEN P, 1988, VET PARASITOL, V26, P329 NANSEN P, 1995, PARASITOL RES, V81, P371 NORDBRINGHERTZ B, 1982, LECTINS BIOL BIOCH C, V2, P83 PANDEY VS, 1973, J HEMINTHOLOGY, V37, P339 PERSSON Y, 1993, EXP MYCOL, V17, P182 RAMAN M, 1996, J VET PARASITOLOGY, V10, P171 ROSENZWEIG WD, 1985, CAN J MICROBIOL, V31, P693 ROUBAUD E, 1941, CR SOC BIOL, V135, P687 SANTOS CP, 1995, ARQ BRAS MED VET ZOO, V47, P123 SPIEGEL Y, 1995, J NEMATOL, V27, P127 TAIRA N, 1992, JARQ-JPN AGR RES Q, V26, P203 THIENPONT D, 1986, DIAGNOSIS HELMINTHIA TUNLID A, 1991, APPL ENVIRON MICROB, V57, P2868 TUNLID A, 1991, J GEN MICROBIOL, V137, P1231 WALLER PJ, 1996, VET PARASITOL, V64, P135 WOLSTRUP J, 1994, J HELMINTHOL, V68, P175 WOLSTRUP J, 1996, J NEMATOL, V28, P129 NR 50 TC 2 PU C A B INTERNATIONAL PI WALLINGFORD PA C/O PUBLISHING DIVISION, WALLINGFORD OX10 8DE, OXON, ENGLAND SN 0022-149X J9 J HELMINTHOL JI J. Helminthol. PD SEP PY 1998 VL 72 IS 3 BP 209 EP 213 PG 5 SC Parasitology; Zoology GA 129UW UT ISI:000076483100005 ER PT J AU Ibarra, F Montenegro, N Vera, Y Boulard, C Quiroz, H Flores, J Ochoa, P TI Comparison of three ELISA tests for seroepidemiology of bovine fasciolosis SO VETERINARY PARASITOLOGY LA English DT Article DE ELISA; faecal examination; fasciolosis; Mexico ID LINKED-IMMUNOSORBENT-ASSAY; DOT-ELISA; HEPATICA; DIAGNOSIS; FASCIOLIASIS; INFECTIONS; CATTLE AB The aim of the present study was to compare the sensitivity, specificity and usefulness of the DIG-ELISA, DOT-ELISA and Indirect ELISA tests for determining the seroprevalence of fasciolosis in cattle under tropical conditions in Mexico. To standardize the tests, positive and negative sera to F. hepatica from 88 Holstein Freisian adult cows located in an enzootic area of fascioliosis acid 88 crossbred adult cattle from a fluke-free area were used. For the epidemiological study, 85 crossbred cattle between 1 to 7 years of age were used. Animals were bled every two months, from March 1995 to September 1996 and the sera obtained were stored at -70 degrees C, until used. Indirect ELISA showed a sensitivity of 96.5% and a specificity of 98.8%, DIG-ELISA 97.5% and 80.0% and DOT-ELISA 93.1% and 95.4%, respectively. During 1995, Indirect ELISA yielded the highest levels of IgG anti-F. hepatica antibodies, However, in 1996, after animal treatment with triclabendazole, DIG-ELISA tended to show higher percentages of antibody-positive animals, but it was not significantly different (p>0.05) from the other tests. Comparisons made in parallel to the faecal sedimentation test demonstrated that all serological tests detected higher percentages of positive animals. Only one serum out of ten (10%) of Paramphistomum spp, cross-reacted with the DOT-ELISA test, but no cross-reaction was observed with sera from animals with other parasites, All ELISA tests were highly sensitive and specific; they may be recommended for use in seroepidemiological surveys for F. hepatica. (C) 1998 Elsevier Science B.V. C1 CENID Parasitol, INIFAP, SAGAR, Cuautla 62500, Morelos, Mexico. Univ Nacl Autonoma Mexico, Fac Med Vet & Zoot, Dept Parasitol, Mexico City 04510, DF, Mexico. INRA, Pathol Aviaire & Parasitol Stn, Ctr Tours, F-37380 Nouzilly, France. RP Ibarra, F, CENID Parasitol, INIFAP, SAGAR, Km 11-5,Carretera Cuernavaca, Cuautla 62500, Morelos, Mexico. CR *COM INT OIE, 1990, REV SCI TECH OIE, V9, P599 *SS I INC, 1982, SAS US GUID STAT BAUTISTAGARFIAS CR, 1985, PARASITOL RES, V76, P135 BOULARD C, 1985, ANN RECH VET, V16, P363 BRADFORD MM, 1976, ANAL BIOCHEM, V72, P248 BURRFOSTER Q, 1974, DESIGN EXPT REALISTI, P46 CALERO JR, 1989, METODO EPIDEMIOLOGIC COURTNEY CH, 1990, J AM VET MED ASSOC, V197, P724 DEMORILLA CA, 1989, VET PARASITOL, V30, P197 FAGBEMI BO, 1990, VET QUART, V12, P35 HANSEN J, 1994, EPIDEMIOLOGY DIAGNOS, P66 HILLYER GV, 1979, J PARASITOL, V65, P680 HILLYER GV, 1991, J PARASITOL, V77, P362 HILLYER GV, 1996, IN PRESS VET PARASIT SHAHEEN HI, 1989, J PARASITOL, V75, P549 WELCH RD, 1987, AM J VET RES, V48, P345 ZAR JH, 1989, BIOSTATISTICAL ANAL NR 17 TC 20 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0304-4017 J9 VET PARASITOL JI Vet. Parasitol. PD JUN 30 PY 1998 VL 77 IS 4 BP 229 EP 236 PG 8 SC Parasitology; Veterinary Sciences GA 117XQ UT ISI:000075808300002 ER PT J AU Gonzalez-Rodriguez, JG Fionova, L TI The effect of structural evolution in INCONEL 601 on intergranular corrosion SO MATERIALS CHEMISTRY AND PHYSICS LA English DT Article DE INCONEL 601; intergranular corrosion; structural evolution; sensitization; grain fragmentation ID CRACKING; ALLOY-600 AB Nonmonotonic variations of the corrosion behaviour of INCONEL 601 alloy with change of sensitization time were observed. It was found that structural evolution appearing during heat treatment at 700 degrees C can be responsible for an increase in corrosion intensity after sensitization up to 24 h and its subsequent decrease with growing sensitization time. Three stages of perturbation of grain structure were fixed, namely, normal grain growth, abnormal grain growth (for sensitization time more than 24 h) and decrease in grain size caused by fragmentation of large grains. Correlation between intensity of intergranular corrosion of INCONEL 601 and effect of fragmentation of large grains has been shown. (C) 1998 Elsevier Science S.A. All rights reserved. C1 Univ Autonoma Estado Morelos, Fac Ciencias Quim & Ingn, Cuernavaca 62115, Morelos, Mexico. RP Fionova, L, Univ Autonoma Estado Morelos, Fac Ciencias Quim & Ingn, Av Univ 1001, Cuernavaca 62115, Morelos, Mexico. CR AHN MK, 1995, CORROSION, V51, P441 AIREY GP, 1983, 3051 EPRI BANDY R, 1983, CORROS SCI, V23, P995 BRIANT CL, 1986, CORROSION, V42, P15 BRUEMMER SM, 1985, P 2 INT S ENV DEGR M, P293 CELS JR, 1976, J ELECTROCHEM SOC, V123, P1152 FIONOVA LK, 1993, GRAIN BOUNDARIES MET PESSALL N, 1979, CORROSION, V35, P100 RANDLE V, 1989, PHILOS MAG A, V59, P1075 WAS GS, 1987, METALL TRANS A, V18, P1313 ZHUKOVA TI, 1983, FIZ MET METALLOVED+, V56, P1138 NR 11 TC 3 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0254-0584 J9 MATER CHEM PHYS JI Mater. Chem. Phys. PD SEP 30 PY 1998 VL 56 IS 1 BP 70 EP 73 PG 4 SC Materials Science, Multidisciplinary GA 117ZB UT ISI:000075811800010 ER PT J AU Hu, H Gomez-Daza, O Nair, PK TI Screen-printed Cu3BiS3-polyacrylic acid composite coatings SO JOURNAL OF MATERIALS RESEARCH LA English DT Article ID SULFIDE THIN-FILMS; BISMUTH SULFIDE AB A technique for preparing electrically conductive coatings of Cu3BiS3 powder in polyacrylic acid matrix is presented. Bi2S3 powder obtained by chemical precipitation was introduced into a freshly prepared CuS chemical deposition bath. After the initial nucleation period, CuS started to deposit on the Bi2S3 surface. The as-obtained CuS-Bi2S3 powder was mixed with polyacrylic acid aqueous solution, and the resulting mixture was used as a paste to form a screen-printed composite coating. Up to 200 degrees C the film behaves like a simple CuS film; the sheet resistance is around 100 Ohm and the crystallized phase in the composite is CuS (Covellite). When the temperature is equal or higher than 250 degrees C, atomic diffusion at the CuS-Bi2S3 interface is promoted, leading to the formation of the ternary compound Cu3BiS3 (Wittichenite) in the composite film. The formation of the compound depends on the temperature, relative abundance of the Bi2S3 and CuS components in the CuS-Bi2S3 pigment, as well as on the annealing atmosphere. C1 Univ Nacl Autonoma Mexico, Dept Mat Solares, Ctr Invest Energia, Temixco 62580, Morelos, Mexico. RP Hu, H, Univ Nacl Autonoma Mexico, Dept Mat Solares, Ctr Invest Energia, Temixco 62580, Morelos, Mexico. CR 1985, CRC HDB CHEM PHYSICS CHOPRA KL, 1982, PHYS THIN FILMS, V12, P167 HU H, 1996, J MATER RES, V11, P739 HU H, 1997, SEMICOND SCI TECHNOL NAIR MTS, 1990, SEMICOND SCI TECH, V5, P1225 NAIR PK, 1991, SEMICOND SCI TECH, V6, P393 NAIR PK, 1993, J ELECTROCHEM SOC, V140, P754 NAIR PK, 1997, J MATER RES, V12, P651 NUFFIELD EW, 1947, ECON GEOL, V42, P147 SEBASTIAN PJ, 1994, SOL ENERG MAT SOL C, V32, P159 NR 10 TC 7 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DR, WARRENDALE, PA 15086 USA SN 0884-2914 J9 J MATER RES JI J. Mater. Res. PD SEP PY 1998 VL 13 IS 9 BP 2453 EP 2456 PG 4 SC Materials Science, Multidisciplinary GA 114RA UT ISI:000075621600016 ER PT J AU Gonzalez-Rodriguez, JG Salinas-Bravo, VM Garcia-Ochoa, E Diaz-Sanchez, A TI Use of electrochemical potential noise to detect initiation and propagation of stress corrosion cracks in a 17-4 PH steel SO CORROSION LA English DT Article DE corrosion potential; electrochemical noise; fast Fourier transform; power spectral density; sodium chloride; steam turbine; strain; stress corrosion cracking ID AUSTENITIC STAINLESS-STEEL; ALPHA-BRASS; GENERATION AB Corrosion potential transients were associated with nucleation and propagation of stress corrosion cracks in a 17-4 precpitation-hardenable (PH) martensitic stainless steel (SS) during slow strain rate tests (SSRT) at 90 degrees C in deaerated sodium chloride (NaCl) solutions. Test solutions included 20 wt% NaCl at pH 3 and 7, similar to normal and faulted steam turbine environments, respectively, Time series were analyzed using the fast Fourier transform method. At the beginning of straining, the consistent noise behavior was perturbed with small potential transients, probably associated with rupture of the surface oxide layer, After yielding, these transients increased in intensity. At maximum Load, the transients were still higher in intensity and frequency, These potential transients were related to crack nucleation and propagation. When the steel did not fail by stress corrosion cracking (SCC), such transients were found only at the beginning of the test. me power spectra showed some differences in all cases in roll-off slope and voltage magnitude, but these were not reliable tools to monitor the initiation and propagation of stress corrosion cracks. C1 UAEM, Fac Ciencias Quim & Ingn, Cuernavaca 62215, Morelos, Mexico. Inst Invest Elect, Dept Fisicoquim Aplicada, Temixco, Morelos, Mexico. Inst Nacl Invest Nucl, Dept Mat, Carretera Mexico Toluca, Salazar Edo Mex, Mexico. RP Gonzalez-Rodriguez, JG, UAEM, Fac Ciencias Quim & Ingn, Av Chamilpa 1001, Cuernavaca 62215, Morelos, Mexico. CR COTTIS RA, 1990, CORROSION, V46, P12 EDEN DA, 1991, CORROSION 91 EDEN DE, 1992, CORROSION 92 GABRIELLI C, 1986, ELECTROCHIM ACTA, V31, P1025 HDLAKY K, 1981, CORROS SCI, V21, P117 HDLAKY K, 1982, CORROS SCI, V22, P231 LEGAT A, 1995, CORROSION, V51, P295 LOTO CA, 1987, CORROSION, V43, P499 LOTO CA, 1989, CORROSION, V45, P136 MANSFELD F, 1993, J ELECTROCHEM SOC, V140, P2205 NEWMAN RC, 1983, SCRIPTA METALL, V17, P621 SHERRAT M, 1994, BRIT CORROS J, V129, P33 SHIBATA T, 1989, CORROS ENG, V38, P175 STEWART J, 1992, CORROS SCI, V33, P73 URCHURTOCHAVARI.J, 1991, CORROSION, V47, P472 WELLS DB, 1992, CORROS SCI, V33, P39 WILLIAMS DE, 1984, J ELECTROANAL CH INF, V180, P549 YAMAKAWA K, 1990, CORROS SCI, V31, P503 NR 18 TC 7 PU NATL ASSN CORROSION ENG PI HOUSTON PA 1440 SOUTH CREEK DRIVE, HOUSTON, TX 77084-4906 USA SN 0010-9312 J9 CORROSION JI Corrosion PD SEP PY 1997 VL 53 IS 9 BP 693 EP 699 PG 7 SC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering GA 112ZR UT ISI:000075525300004 ER PT J AU Parra, RS George, PJ Jimenez-Gonzalez, AE Banos, L Nair, PK TI Structural and electrical properties of annealed In-Bi2S3 thin films SO JOURNAL OF SOLID STATE CHEMISTRY LA English DT Article ID CHEMICAL-DEPOSITION AB Intrinsic bismuth sulfide deposited on indium thin films (similar to 20nm) change to n-type when annealed in air or nitrogen atmosphere. As deposited bismuth sulfide on the In films is amorphous and electrically very resistive, Annealing the films in air at 200, 300, and 400 degrees C results in the formation of In2O3 as observed in the X-ray diffraction patterns of the films. The dark conductivity of the In + bismuth sulfide films nitrogen-annealed at 300 degrees C attains a value of 600 Ohm(-1) cm(-1), which is an improvement by more than eight orders of magnitude compared with as-prepared films. This improvement is attributed to amorphous-crystalline transformation and the presence of metallic bismuth and In2O3 in the annealed films. An etching test in 1 M solution of HCl indicates that these films are rather stable in acid medium. (C) 1998 Academic Press. C1 Univ Nacl Autonoma Mexico, Ctr Invest Energia, Dept Solar Energy Mat, Temixco 62580, Morelos, Mexico. Dept Mat Met & Ceram, Mexico City 04510, DF, Mexico. RP Parra, RS, Univ Nacl Autonoma Mexico, Ctr Invest Energia, Dept Solar Energy Mat, Temixco 62580, Morelos, Mexico. CR BEARDEN JA, 1967, REV MOD PHYS, V39, P78 BHATTACHARYA RN, 1982, J ELECTROCHEM SOC, V129, P332 BISWAS S, 1986, J ELECTROCHEM SOC, V133, P48 CULLITY BD, 1978, ELEMENTS XRAY DIFFRA GARCIA VM, 1996, J ELECTROCHEM SOC, V143, P2892 GEORGE PJ, 1995, APPL PHYS LETT, V66, P26 KALYANASUNDARAM K, 1985, SOL CELLS, V15, P93 MADELUNG O, 1992, SEMICONDUCTORS OTHER, P50 NAIR MTS, 1990, SEMICOND SCI TECH, V5, P1225 NAIR PK, 1991, SEMICOND SCI TECH, V6, P393 NAIR PK, 1993, J ELECTROCHEM SOC, V140, P1085 RINCON ME, 1996, J PHYS CHEM SOLIDS, V57, P1947 RINCON ME, 1997, SEMICOND SCI TECH, V12, P467 NR 13 TC 1 PU ACADEMIC PRESS INC PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0022-4596 J9 J SOLID STATE CHEM JI J. Solid State Chem. PD JUL PY 1998 VL 138 IS 2 BP 290 EP 296 PG 7 SC Chemistry, Inorganic & Nuclear; Chemistry, Physical GA 110FM UT ISI:000075369600015 ER PT J AU Barragan, RM Arellano, VM Heard, CL TI Performance study of a double-absorption water calcium chloride heat transformer SO INTERNATIONAL JOURNAL OF ENERGY RESEARCH LA English DT Article DE heat transformers; absorption systems; energy recycling ID WORKING FLUID; SYSTEM AB In order to increase the temperature lift and efficiency of single-absorption heat transformers there are other possible arrangements. Double-absorption heat transformers have a relatively simple design and smaller size compared to two-stage heat transformers. In this work, the thermodynamic performance of the water/calcium chloride system was modelled for a double-absorption heat transformer. Results indicate that temperature lifts of up to 40 degrees C are possible with coefficients of performance close to 0 3. (C) 1998 John Wiley & Sons, Ltd. C1 Inst Invest Elect, Unidad Geotermia, Cuernavaca 62000, Morelos, Mexico. RP Barragan, RM, Inst Invest Elect, Unidad Geotermia, POB 475, Cuernavaca 62000, Morelos, Mexico. EM rmb@iie.org.mx CR ALEFELD G, 1990, P SEM INT CONS EN AP, P1 APBLETT AW, 1991, J MATER CHEM, V1, P143 BARRAGAN RM, 1996, INT J ENERG RES, V20, P651 CIAMBELLI P, 1988, HEAT RECOVERY SYSTEM, V8, P445 CIAMBELLI P, 1988, HEAT RECOVERY SYSTEM, V8, P451 EISA MAR, 1986, J HEAT RECOV SYST, V6, P443 HEROLD KE, 1991, INT J REFRIG, V14, P156 KEENAN JH, 1978, THERMODYNAMIC PROPER KRIPALANI VM, 1984, J HEAT RECOV SYST, V4, P129 REBELLO WJ, 1988, HEAT TRANSFER EQUIPM, P655 RIVERA W, 1994, HEAT RECOV SYST CHP, V14, P173 RIVERA W, 1994, HEAT RECOV SYST CHP, V14, P185 SIDDIGMOHAMMED BE, 1983, CHEM ENG RES DES, V61, P283 STEPHAN K, 1984, HEAT RECOVERY SYSTEM, V4, P365 ZHUO CZ, 1993, INT J REFRIG, V16, P357 NR 15 TC 0 PU JOHN WILEY & SONS LTD PI W SUSSEX PA BAFFINS LANE CHICHESTER, W SUSSEX PO19 1UD, ENGLAND SN 0363-907X J9 INT J ENERG RES JI Int. J. Energy Res. PD JUL PY 1998 VL 22 IS 9 BP 791 EP 803 PG 13 SC Energy & Fuels; Nuclear Science & Technology GA 105GT UT ISI:000075064900002 ER PT J AU Almeraya, F Martinez-Villafane, A Gaona, C Romero, MA Malo, JM TI Hot corrosion of the steel SA213-T22 and SA213-TP347H in 80%V2O5-20%Na2SO4 mixture SO REVISTA DE METALURGIA LA Spanish DT Article DE hot corrosion; electrochemical techniques; corrosion rate AB Many hot corrosion problems in industrial and utility boilers are caused by molten salts. The corrosion processes which occur in salts are of an electrochemical nature, and so they can be studied using electrochemical test methods. In this research, electrochemical techniques in molten salt systems have been used for the measurements of molten corrosion processes. Electrochemical test methods are described here for a salt mixture of 80% V2O5-20%Na2SO4 at 540-680 degrees C. To establish better the electrochemical corrosion rate mearurements for molten salt systems, information from electrochemical potentiodynamic polarization curves, such as polarization resistance and Tafel slopes were used in this study to generate corrosion rate data. The salt was contained in a quartz crucible inside a stainless steel retort. The atmosphere used was air. A thermocouple sheathed with quartz glass was introduced into the molten salt for temperature monitoring and control. Two materials were tested in the molten mixture: SA213-T22 and SA213-TP347H steels. The corrosion rates values obtained using electrochemical methods were around 0.58-7.14 mm/yr (22.9-281 mpy). The corrosion rate increase with time. C1 Ctr Invest Mat Avanzados, SC Div Deterioro Mat, Dpto Corros, Chihuahua 31110, Mexico. Univ Autonoma Metropolitana, Area Ciencia Mat, Mexico City, DF, Mexico. Inst Invest Elect, Dpto Fis Quim Aplicada, Cuernavaca, Morelos, Mexico. RP Almeraya, F, Ctr Invest Mat Avanzados, SC Div Deterioro Mat, Dpto Corros, Miguel Cervantes 120,Complejo Ind Chihuahua, Chihuahua 31110, Mexico. CR ALMERAYA CF, 1997, THESIS UNAM MEXICO FUENTES SR, 1984, B IIE, V8, P160 LAI YG, 1990, HIGH TEMPERATURE COR, P145 MARTINEZ VA, 1994, PROBLEMATICA MAT CEN, P1 RAHMEL A, 1987, MATER SCI ENG, P345 RAPP RA, 1987, MATER SCI ENG, V87, P319 RAPP RA, 1990, HIGH TEMP SCI, V27, P355 NR 7 TC 1 PU CENIM PI MADRID PA AVDA. GREGORIO DEL AMO, 8, 28040 MADRID, SPAIN SN 0034-8570 J9 REV METALURGIA JI Rev. Metal. PD JAN-FEB PY 1998 VL 34 IS 1 BP 11 EP 17 PG 7 SC Metallurgy & Metallurgical Engineering GA ZZ752 UT ISI:000074763600002 ER PT J AU Wolf, KB Mendlovic, D Zalevsky, Z TI Generalized Wigner function for the analysis of superresolution systems SO APPLIED OPTICS LA English DT Article AB The generalized Wigner function is able to represent light distributions that contain spatial and temporal information. The use of such a generalized Wigner distribution function for analysis and understanding of temporally restricted superresolving systems is demonstrated. These systems gain spatial resolution by conversion of the temporal degrees of freedom to spatial degrees of freedom. (C) 1998 Optical Society of America. C1 Univ Nacl Autonoma Mexico, Inst Invest Matemat Aplicadas & Sistemas, Cuernavaca 62251, Morelos, Mexico. Tel Aviv Univ, Fac Engn, IL-69978 Tel Aviv, Israel. RP Wolf, KB, Univ Nacl Autonoma Mexico, Inst Invest Matemat Aplicadas & Sistemas, Apartado Postal 48-3, Cuernavaca 62251, Morelos, Mexico. CR BASTIAANS MJ, 1979, OPT ACTA, V26, P1333 CASTANOS O, 1986, SPRINGER VERLAG LECT, V250, P159 LEE HW, 1995, PHYS REP, V259, P147 LOHMANN AW, 1993, J OPT SOC AM A, V10, P2181 LUKOSZ W, 1966, J OPT SOC AM, V56, P1463 MENDLOVIC D, 1997, APPL OPTICS, V36, P2353 MENDLOVIC D, 1997, J OPT SOC AM A, V14, P558 MENDLOVIC D, 1997, J OPT SOC AM A, V14, P563 MENDLOVIC D, 1997, OPTIK, V107, P49 WIGNER E, 1932, PHYS REV, V40, P749 WOLF KB, 1996, OPT COMMUN, V132, P343 NR 11 TC 5 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA SN 0003-6935 J9 APPL OPT JI Appl. Optics PD JUL 10 PY 1998 VL 37 IS 20 BP 4374 EP 4379 PG 6 SC Optics GA ZZ393 UT ISI:000074724900007 ER PT J AU Miranda-Gasca, MA Gomez-Caballero, JA Eastoe, CJ TI Borate deposits of northern Sonora, Mexico: Stratigraphy, tectonics, stable isotopes, and fluid inclusions SO ECONOMIC GEOLOGY AND THE BULLETIN OF THE SOCIETY OF ECONOMIC GEOLOGISTS LA English DT Article ID SULFUR-DIOXIDE; WESTERN TURKEY; REDUCTION AB Mid-Tertiary tectonic extension produced basins with lacustrine sediments bearing borates, zeolites, gypsum, and detrital gold in northern Sonora. Colemanite deposits associated with howlite, gypsum, and celestite are present in the Magdalena and Tubutama basins. In the Magdalena basin, the La Tinaja del Oso deposit contains at least two generations of colemanite, the first replacing stratiform and probably syngenetic ulexite, and the second, more voluminous, of clear epigenetic origin. Fluid inclusions in epigenetic colemanite indicate deposition from very low-salinity hydrothermal fluid at temperatures up to 180 degrees C, mainly 100 degrees to 140 degrees C. Water of crystallization from epigenetic colemanite has SD values of -35 to -20 per mil, indicating that water in the hydrothermal fluid was of meteoric origin but was not lacustrine brine because of the low salinity. The delta(34)S values of gypsum associated with colemanite, 4.1 to 10.6 per mil, are typical of sulfate in extensional basins of the region. A realgar specimen has a delta(34)S value of -32.9, consistent with formation of sulfide by bacterial reduction of sulfate. Borate was initially deposited as ulexite, then replaced by colemanite after burial. Epigenetic colemanite formed after lacustrine brine had disappeared, probably by circulating meteoric water heated as a result of high thermal gradients in the upper plates of metamorphic core complexes. We formally propose the names Magdalena, Cuesta, El Torreon, and Tubutama Formations for mid-Tertiary sedimentary and volcanic rocks of the upper plates in the Magdalena and Tubutama basins. The name Baucarit Formation should be restricted to the younger sedimentary rocks overlying these formations. C1 Univ Arizona, Dept Geosci, Tucson, AZ 85721 USA. Natl Autonomous Univ Mexico, Inst Geol, Mexico City 04510, DF, Mexico. RP Miranda-Gasca, MA, Andador 101 L17 M306,Col Ciudad Chapultepec, Cuernavaca 62030, Morelos, Mexico. 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Geol. Bull. Soc. Econ. Geol. PD JUN-JUL PY 1998 VL 93 IS 4 BP 510 EP 523 PG 14 SC Geochemistry & Geophysics GA ZV371 UT ISI:000074297900006 ER PT J AU Rincon, ME Sanchez, M George, PJ Sanchez, A Nair, PK TI Comparison of the properties of bismuth sulfide thin films prepared by thermal evaporation and chemical bath deposition SO JOURNAL OF SOLID STATE CHEMISTRY LA English DT Article ID BI2S3 AB Highly oriented polycrystalline Bi2S3 thin films with crystallinities superior to those obtained in chemically deposited Bi2S3 thin films were prepared by direct evaporation of bismuth sulfide precipitate. The XRD patterns of these films show preferential growth of bismuth and bismuthinite planes, and this growth could be correlated to substrate temperature and substrate type. For films deposited on glass substrates at room temperature, the XRD pattern shows an incipient growth of Bi2S3 (bismuthinite) along the [020], [220], and [021] directions. At these angles, Bi planes also diffract and might be the major component of this alloy, XRD spectra of films deposited on bare glass in the substrate temperature range 150-300 degrees C show that the film growth evolves from an oriented to a more random pattern. At a substrate temperature of 250 degrees C, the crystallization of bismuth and bismuthinite is accelerated on glass substrates with a Cr coating and inhibited on glass substrates with a SnO2 coating. The reflectance spectra of the films deposited at 250 degrees C on uncoated and SnO2-coated glass substrates show that the crystallinity is dominated by Bi2S3, whereas in films deposited on a Cr grid Bi is a strong component. The optoelectronic properties of the deposited films indicate very conductive layered structures with E-g values in the range 1.2-1.6 eV. Compared with the above, chemically deposited thin films were less crystalline and more stoichiometric, with a lower conductivity and higher optical band gap (1.5-2.0 eV). The possible application of these films in heterojunction and photoelectrochemical devices is suggested. (C) 1998 Academic Press. C1 Univ Nacl Autonoma Mexico, Ctr Invest Energia, Temixco 62580, Morelos, Mexico. RP Rincon, ME, Univ Nacl Autonoma Mexico, Ctr Invest Energia, Temixco 62580, Morelos, Mexico. 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Solid State Chem. PD MAR PY 1998 VL 136 IS 2 BP 167 EP 174 PG 8 SC Chemistry, Inorganic & Nuclear; Chemistry, Physical GA ZR527 UT ISI:000073986500003 ER PT J AU Farfan, N Hopfl, H TI Crystal and molecular structure of [Hg-3(H(2)pdm)(2)(Hpdm)(mu-Cl)(2)Cl-3] SO HETEROATOM CHEMISTRY LA English DT Article ID MERCURY(II) CHLORIDE; DERIVATIVES AB The reaction between mercury(II)chloride and 2,6-pyridinedimethanol provides a molecule with the empirical formula [Hg-3(H(2)pdm)(2)(Hpdm) (mu-Cl)(2)Cl-3] whose crystal and molecular structure has been studied: a = 10.640(1), b = 10.818(2), c = 13.159(2) Angstrom, alpha = 88.480(5), beta = 75.067(4), gamma = 89.736(5)degrees V = 1463.0(4) Angstrom(3), Z = 2, P-1. The molecule consists of a central [Hg(Hpdm)Cl] fragment that is connected by chloro bridges to two lateral fragments of identical constitution, [Hg(H(2)pdm)Cl-2]. The coordination geometry around the central mercury atom is distorted octahedral, while the lateral metal atoms ave located in significantly different, distorted square-pyramidal polyhedrons. The tridentate ligand induces the formation of the square-pyramidal environment instead of the trigonal-bipyramidal one that is normally preferred by d(10) systems. (C) 1998 John Wiley & Sons, Inc. C1 Inst Politecn Nacl, Ctr Invest & Estudios Avanzados, Dept Quim, Mexico City 07000, DF, Mexico. Univ Autonoma Estado Morelos, Dept Quim, Cuernavaca 62210, Morelos, Mexico. RP Farfan, N, Inst Politecn Nacl, Ctr Invest & Estudios Avanzados, Dept Quim, Apdo Postal 14-740, Mexico City 07000, DF, Mexico. 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PY 1998 VL 9 IS 4 BP 377 EP 382 PG 6 SC Chemistry, Multidisciplinary GA ZQ911 UT ISI:000073915400005 ER PT J AU Gamboa, SA Sebastian, PJ Rivera, MA TI Characterization of p-CdTe obtained by CVTG tellurization of electrodeposited CdTe SO SOLAR ENERGY MATERIALS AND SOLAR CELLS LA English DT Article DE p-CdTe; electrodeposition; tellurization ID THIN-FILMS AB CdTe thin films were electrodeposited from an ethylene-glycol-based bath by the galvanostatic method. As-deposited and tellurized films were characterized by structural, opto-electronic and photoelectrochemical methods. As-deposited films were powdery in nature and showed n-type conductivity due to the elemental nature of the film. The film stoichiometry was improved after tellurization of the film at 300 degrees C by a new technique called chemical vapor transport by gas (CVTG) in a tubular furnace. Tellurized films showed near stoichiometry with p-type conductivity in the bulk and n-type surface conductivity, which is explained by the 'seb' model for electrical conductivity in electrodeposited-chalcogenized films. (C) 1998 Published by Elsevier Science B.V. All rights reserved. C1 Univ Nacl Autonoma Mexico, Ctr Invest Energia, Temixco 62580, Morelos, Mexico. RP Gamboa, SA, Univ Nacl Autonoma Mexico, Ctr Invest Energia, Temixco 62580, Morelos, Mexico. CR BOCKRIS JO, 1989, MATER CHEM PHYS, V22, P249 CARLOS A, IN PRESS ADV MAT OPT DAS SK, 1993, SOL ENERG MAT SOL C, V30, P107 GOMES WP, 1982, PROG SURF SCI, V12, P155 GUO YP, 1993, SOL ENERG MAT SOL C, V29, P115 KOLYER CL, 1992, J ELECTROCHEM SOC, V139, P406 KROGER FA, 1978, J ELECTROCHEM SOC, V125, P2028 LOAEZA P, 1990, J MATER SCI LETT, V9, P11 MAUSIN G, 1986, J ELECTROANAL CHEM, V202, P323 PANDEY RK, 1992, SOL ENERG MAT SOL C, V26, P285 RAJESHWAR K, 1992, ADV MATER, V4, P1 RASTOGI AC, 1995, SOL ENERG MAT SOL C, V36, P121 SANCHEZ A, 1995, SEMICOND SCI TECH, V10, P87 SEBASTIAN PJ, IN PRESS APPL PHYS L SEBASTIAN PJ, 1995, SOL ENERG MAT SOL C, V39, P55 NR 15 TC 8 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0927-0248 J9 SOLAR ENERG MATER SOLAR CELLS JI Sol. Energy Mater. Sol. Cells PD APR PY 1998 VL 52 IS 3-4 BP 293 EP 299 PG 7 SC Energy & Fuels; Materials Science, Multidisciplinary GA ZQ253 UT ISI:000073838800011 ER PT J AU Sanchez-Juarez, A Tiburcio-Silver, A Ortiz, A TI Properties of fluorine-doped ZnO deposited onto glass by spray pyrolysis SO SOLAR ENERGY MATERIALS AND SOLAR CELLS LA English DT Article DE fluorine-doped ZnO; thin films; spray pyrolysis ID CHEMICAL VAPOR-DEPOSITION; ZINC-OXIDE FILMS; THIN-FILMS; TRANSPARENT CONDUCTORS; SOLAR-CELLS AB Fluorine-doped ZnO (FZO) thin films were deposited onto glass by the spray pyrolysis process, using zinc acetate and NH4F as precursors. The role of F/Zn atomic ratio, in the starting solution, and the substrate temperature were investigated and the optimum deposition conditions have been outlined. The X-ray diffraction analyses of the films show that there is incorporation of F atoms in the film. The FZO films are of polycrystalline nature with a preferential growth along (0 0 2) plane parallel to the surface of the substrate for temperatures higher than 400 degrees C. It is observed that fluorine incorporation in the films affects the grain size, which decreases as the F/Zn atomic ratio increases, for the same substrate temperature. The films are uniform and exhibit an optical transmittance above 85% in the visible region. A critical substrate temperature (425 degrees C) was observed at which the films show an n-type electrical dark conductivity as high as 9 (Ohm cm)(-1) when using a solution flow rate of 16 ml/min and a gas flow rate of 10 l/min. (C) 1998 Elsevier Science B.V. All rights reserved. C1 Univ Nacl Autonoma Mexico, Ctr Invest Energia, Temixco 62580, Morelos, Mexico. SEP, Inst Tecnol Toluca, Div Estudios Posgrado, Mexico City, DF, Mexico. Univ Nacl Autonoma Mexico, IIM, Mat Res Inst, Mexico City 04510, DF, Mexico. RP Sanchez-Juarez, A, Univ Nacl Autonoma Mexico, Ctr Invest Energia, POB 34, Temixco 62580, Morelos, Mexico. CR *CNRS, 1986, HDB CHEM PHYS, P171 ARANOVICH J, 1977, J APPL PHYS, V51, P4260 ARANOVICH J, 1979, J VAC SCI TECHNOL, V16, P994 ARANOVICH JA, 1980, J APPL PHYS, V51, P4260 BLOCHER JM, 1974, J VAC SCI TECHNOL, V11, P680 CHOPRA KL, 1969, THIN FILM PHENOMENA, CH4 CHOPRA KL, 1983, THIN SOLID FILMS, V102, P1 EBERSPACHER C, 1986, THIN SOLID FILMS, V136, P1 ELIZALDETORRES J, 1996, MATER LETT, V26, P41 FOSTER NF, 1969, J VAC SCI TECHNOL, V6, P111 HAACKE G, 1977, ANNU REV MATER SCI, V7, P73 HU JH, 1991, SOL CELLS, V30, P437 IKEDA T, 1994, SOL ENERG MAT SOL C, V34, P379 JUAREZ AS, 1995, THESIS UNAM MEXICO KLUG HP, 1974, XRAY DIFFRACTION PRO, CH9 MAJOR S, 1983, THIN SOLID FILMS, V108, P333 MANIFACIER JC, 1982, THIN SOLID FILMS, V90, P297 MCADIE HG, 1966, J INORG NUCL CHEM, V28, P2801 MINAMI T, 1985, JPN J APPL PHYS, V24, L605 ORTIZ A, 1988, J NONCRYST SOLIDS, V103, P9 QIU SN, 1987, SOL ENERG MATER, V15, P261 RISTOV M, 1987, THIN SOLID FILMS, V149, P65 ROTH AP, 1981, J APPL PHYS, V52, P6685 SANCHEZJUAREZ A, IN PRESS SANCHEZJUAREZ A, 1988, P 8 EUR PHOT SOL EN, V6, P1008 SANCHEZJUAREZ A, 1995, P 13 EUR PHOT SOL EN, V7, P1609 SHIH I, 1985, J APPL PHYS, V58, P2400 STOLT L, 1993, APPL PHYS LETT, V62, P597 NR 28 TC 28 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0927-0248 J9 SOLAR ENERG MATER SOLAR CELLS JI Sol. Energy Mater. Sol. Cells PD APR PY 1998 VL 52 IS 3-4 BP 301 EP 311 PG 11 SC Energy & Fuels; Materials Science, Multidisciplinary GA ZQ253 UT ISI:000073838800012 ER PT J AU Rincon, ME Sanchez, M Olea, A Ayala, I Nair, PK TI Photoelectrochemical behavior of chemically deposited CdSe and coupled CdS/CdSe semiconductor films SO SOLAR ENERGY MATERIALS AND SOLAR CELLS LA English DT Article DE thin films; photoelectrochemical effects; open-circuit voltage; short-circuit current density ID SULFIDE THIN-FILMS; BATH DEPOSITION; CADMIUM SELENIDE; N-TYPE; CELLS; MECHANISM AB Photoelectrochemical effects at chemically deposited CdSe thin films (2000 Angstrom) coupled with as-prepared and air annealed (250 degrees C) CdS films have been investigated by monitoring open-circuit voltage (V-oc) and short-circuit current density (I-sc) at varying incident light intensities and for different heat-treatments temperatures. Two consecutive chemical baths were used in the coupled system. Each bath has been optimized in earlier studies for the deposition of highly photosensitive CdS and CdSe thin films. The photoelectrochemical behavior of single and coupled films was investigated in ferricyanide redox couples. The enhanced short-circuit photocurrent of the as-deposited CdS/CdSe system, despite their lower photosensitivity, indicated that charge separation improved in the coupled system. The role of post-deposition thermal treatments in improving the photoelectrochemical cell characteristics and stability of coupled semiconductors was investigated. Excellent I-V properties were obtained for CdSe and CdS250/CdSe photoelectrodes annealed at 280 degrees C. For the coupled system: V-oc = 960 mV; I-sc = 8.6 mA/cm(2); fill factor (ff) = 0.53 and cell efficiency (eta) = 4.2%. The linearity of V-oc/ln(I-L) and I-sc/I-L plots supports the Schottky-Mott model for these interfaces. The stability of the coupled photoanode is superior to that of the CdSe only-film for the initial 3 h. (C) 1998 Elsevier Science B.V. All rights reserved. C1 Univ Nacl Autonoma Mexico, IIM, Lab Energia Solar, Photovolta Syst Grp, Temixco 62580, Morelos, Mexico. RP Rincon, ME, Univ Nacl Autonoma Mexico, IIM, Lab Energia Solar, Photovolta Syst Grp, Temixco 62580, Morelos, Mexico. CR ALJINOVIC L, 1983, J ENG PHYS, V25, P51 BOTTO IL, 1995, THERMOCHIM ACTA, V249, P325 BOUDREAU RA, 1983, J ELECTROCHEM SOC, V130, P513 CHANDRA S, 1980, J PHYS D, V13, P1757 GARCIA VM, 1995, SEMICOND SCI TECH, V10, P427 GARCIACUENCA MV, 1987, J PHYS D, V20, P51 GOTOVAC V, 1991, U BEOGRAD PUBL EL TF, V1, P63 GRAETZEL M, 1990, P 1 WORLD REN EN C, V1, P120 KRPAN D, 1984, ELECTROCHIM ACTA, V29 LINCOT D, 1992, J ELECTROCHEM SOC, V139, P1880 LIU D, 1993, J PHYS CHEM-US, V97, P10769 LOKHANDE CD, 1982, SOL ENERG MATER, V7, P313 LOKHANDE CD, 1984, SOLID STATE COMMUN, V49, P765 MAHAPATRA PK, 1994, SOL ENERG MAT SOL C, V32, P29 MANDAL KC, 1992, J MATER SCI, V27, P4355 MOSS TS, 1973, SEMICONDUCTOR OPTOEL NAIR MTS, 1993, J APPL PHYS, V74, P1879 NAIR MTS, 1994, J APPL PHYS, V75, P1557 ORTEGABORGES R, 1993, J ELECTROCHEM SOC, V140, P3464 ORTON JW, 1982, J APPL PHYS, V53, P1602 PERKOWITZ S, 1993, OPTICAL CHARACTERIZA PRATT DR, 1981, J ELECTROCHEM SOC, V128, P1627 REICHMAN J, 1981, ACS SYM SER, V146, P359 SAVADOGO O, 1992, MATER CHEM PHYS, V31, P301 NR 24 TC 9 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0927-0248 J9 SOLAR ENERG MATER SOLAR CELLS JI Sol. Energy Mater. Sol. Cells PD APR PY 1998 VL 52 IS 3-4 BP 399 EP 411 PG 13 SC Energy & Fuels; Materials Science, Multidisciplinary GA ZQ253 UT ISI:000073838800018 ER PT J AU Fernandez, AM Calixto, ME Sebastian, PJ Gamboa, SA Hermann, AM Noufi, RN TI Electrodeposited and selenized (CuInSe2) (CIS) thin films for photovoltaic applications SO SOLAR ENERGY MATERIALS AND SOLAR CELLS LA English DT Article DE thin films; selenization; stoichiometry AB In the present communication, the authors report results on the characterization of electrodeposited and selenized (CuInSe2) (CIS) thin films, The selenization process was carried out using a technique called chemical vapor transport by gas (CVTG). The precursors as well as selenized films were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and electron microprobe analysis (EPMA). The film stoichiometry improved after selenization at 550 degrees C. The films were formed with a mixed composition of the binary as well as the ternary phases. (C) 1998 Elsevier Science B.V. All rights reserved. C1 Univ Nacl Autonoma Mexico, Ctr Invest Energia, Temixco 62580, Morelos, Mexico. Univ Colorado, Dept Phys, Boulder, CO 80309 USA. Natl Renewable Energy Lab, Golden, CO 80401 USA. RP Fernandez, AM, Univ Nacl Autonoma Mexico, Ctr Invest Energia, Temixco 62580, Morelos, Mexico. CR BUBE RH, 1960, PHOTOCONDUCTIVITY SO GORKA M, 1979, SOL ENERG MATER, V1, P313 GRINDLE SP, 1980, J APPL PHYS, V51, P10 HERRERO J, 1991, J APPL PHYS, V69, P429 HOIG W, 1978, THIN SOLID FILMS, V48, P67 JEYAKUMAR R, 1994, MATER RES BULL, V29, P195 KAZMERSKI LL, 1979, THIN SOLID FILMS, V57, P99 MICKELSEN RA, 1981, P 15 IEEE PHOT SPEC, P800 QUI CX, 1989, CAN J PHYS, V67, P444 RAJA P, 1986, B MATH SCI, V8, P279 SALVIATI G, 1983, THIN SOLID FILMS, V104, L75 SCHUMANN B, 1981, SOV PHYS-CRYSTALLOGR, V26, P678 THOUIN L, 1992, P 11 EC PHOT SOL EN, P866 TUTTLE JR, 1993, P 7 SUNSH PROJ THIN NR 14 TC 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0927-0248 J9 SOLAR ENERG MATER SOLAR CELLS JI Sol. Energy Mater. Sol. Cells PD APR PY 1998 VL 52 IS 3-4 BP 423 EP 431 PG 9 SC Energy & Fuels; Materials Science, Multidisciplinary GA ZQ253 UT ISI:000073838800020 ER PT J AU Nair, MTS Pena, Y Campos, J Garcia, VM Nair, PK TI Chemically deposited Sb2S3 and Sb2S3-CuS thin films SO JOURNAL OF THE ELECTROCHEMICAL SOCIETY LA English DT Article ID SOLAR CONTROL CHARACTERISTICS; CONTROL COATINGS; CUXS; SULFIDE; CELLS AB Thin films of antimony sulfide have been deposited from chemical baths containing antimony trichloride and sodium thiosulfate maintained at 10 degrees C. Upon annealing in nitrogen at 300 degrees C for 1 h, the films become photosensitive with photo-to dark-current ratio of two to three orders of magnitude at 2 kW m(-2) tungsten halogen radiation. The annealed films are crystalline with an X-ray diffraction pattern matching that of stibnite, Sb2S3, (JCPDS 6-0474) and show an optical bandgap of 1.78 eV. Deposition of a thin film of CuS on the antimony sulfide thin film and subsequent annealing in nitrogen at 250 degrees C for 1 h produces films with acceptable salar control characteristics: integrated visible transmittance, T-vis 15%; integrated visible reflectance, R-vis 12%; integrated infrared transmittance, T-ir, 14%; integrated infrared reflectance, R-ir 36%; and a shading coefficient of about 0.35. The X-ray diffraction patterns of the annealed Sb2S3-CuS thin films indicate the formation of a ternary compound with the structure of famatinite, Cu3SbS4. C1 Univ Nacl Autonoma Mexico, Ctr Invest Energia, Dept Solar Energy Mat, Temixco 62580, Morelos, Mexico. RP Nair, MTS, Univ Nacl Autonoma Mexico, Ctr Invest Energia, Dept Solar Energy Mat, Temixco 62580, Morelos, Mexico. CR ABLOVA MS, 1976, SOV PHYS SEMICOND, V10, P629 AYLWARD GH, 1974, SI CHEM DATA, P115 BLACK J, 1957, J PHYS CHEM SOLIDS, V2, P240 CHOPRA KL, 1982, PHYS THIN FILMS, V12, P201 COPE D, 1959, 2875359, US DESHMUKH LP, 1994, J ELECTROCHEM SOC, V141, P1779 GEORGE J, 1980, SOLID STATE COMMUN, V33, P987 GRIGAS J, 1976, PHYS STATUS SOLIDI A, V37, K39 GROZDANOV I, 1994, SEMICOND SCI TECH, V9, P1234 HANCOCK RD, 1984, J COORD CHEM, V13, P309 HODES G, 1987, PHYS REV B, V36, P4215 HUANG L, 1994, J ELECTROCHEM SOC, V141, P2536 KITAEV GA, 1965, ZH FIZ KHIM+, V39, P1101 LIDE DR, 1995, HDB CHEM PHYSICS, P12 MADY KA, 1988, J MATER SCI, V23, P3636 MANDAL KC, 1990, J PHYS CHEM SOLIDS, V51, P1339 NAIR MTS, 1989, SEMICOND SCI TECH, V4, P599 NAIR MTS, 1991, J PHYS D APPL PHYS, V24, P450 NAIR MTS, 1993, J ELECTROCHEM SOC, V140, P212 NAIR PK, 1989, SEMICOND SCI TECH, V4, P807 NAIR PK, 1990, SOL ENERG MATER, V20, P235 NAIR PK, 1991, J PHYS D APPL PHYS, V24, P441 NAIR PK, 1991, MAT MANUF PROCESSES, V6, P207 NAIR PK, 1992, SEMICOND SCI TECH, V7, P239 NAIR PK, 1993, J ELECTROCHEM SOC, V140, P754 NAIR PK, 1997, J MATER RES, V12, P651 OKAMOTO K, 1973, JPN J APPL PHYS, V12, P1130 POERSCHKE R, 1992, SEMICONDUCTORS OTHER, P63 QUI CX, 1987, SOL ENERG MATER, V15, P219 SAVADOGO O, 1992, SOL ENERG MAT SOL C, V26, P117 SAVADOGO O, 1994, J ELECTROCHEM SOC, V141, P2871 SAVADOGO O, 1994, J PHYS D APPL PHYS, V27, P1070 SMITH RM, 1995, 46 NIST NR 33 TC 37 PU ELECTROCHEMICAL SOC INC PI PENNINGTON PA 10 SOUTH MAIN STREET, PENNINGTON, NJ 08534 USA SN 0013-4651 J9 J ELECTROCHEM SOC JI J. Electrochem. Soc. PD JUN PY 1998 VL 145 IS 6 BP 2113 EP 2120 PG 8 SC Electrochemistry; Materials Science, Coatings & Films GA ZN999 UT ISI:000073705200045 ER PT J AU Lopez-Lopez, D Wong-Moreno, A Teran-Sarabia, A Velasco-Tellez, A Martinez, L TI Mechanistic aspects of carburization in oil-fired power plants SO MATERIALS AND CORROSION-WERKSTOFFE UND KORROSION LA English DT Article AB Materials degradation due to surface carburization has been recently reported in connection to failures or high corrosion rates of superheaters or reheater tubes of oil-fired and coal-fired boilers. Reducing conditions to explain carburization process of materials are hardly to expect because fuel is burned with oxygen excess to attain its complete combustion. The formation of sodium carbonate as a carburization catalyst has been proposed in order to explain carburization phenomenon in boilers, however this carburization catalyst has been rarely found in ash deposits on carburized tubes. In order to study the role of some compounds present in boiler deposits as possible carburization catalysts and the corrosion behavior of 304H-type stainless steel in boiler deposits under reducing conditions, pack-carburization experiments were carried out at 650 degrees C by 1000 hours. Mixtures of 60 wt.% carbon and 40 wt.% of different typical compounds of boiler tube deposits were used. The experimental results show that ash deposits and several deposit compounds act as carburization enhancers, they increase carburization of the alloy if carbon is present in ash deposits. Furthermore, corrosion were detected in some cases. However, other mechanisms might be considered to explain carburization of boiler steels. Analysis of these mechanisms is presented. It is concluded that surface deposition of partially burned particles and its further burning supplying carbon monoxide to the local atmosphere is considered as the main mechanism contributing to carburization of boiler tubes. C1 Inst Invest Elect, Unidad Sistemas Combust, Cuernavaca 62001, Morelos, Mexico. Hojalata & Lamina SA CV, Monterrey, Nuevo Leon, Mexico. UNAM, Inst Fis, Cuernavaca, Morelos, Mexico. RP Lopez-Lopez, D, Inst Invest Elect, Unidad Sistemas Combust, Av Reforma 113,Col Palmira,Apartado Postal 1-475, Cuernavaca 62001, Morelos, Mexico. CR BAKKER WT, 1991, CORROSION 91 HOUST T BELLAN J, 1985, T ASME, V107, P744 CASARINI G, 1986, TERMOTECNIA, P33 CLARK K, 1990, POWER, P53 CUTTLER AJB, 1978, BRIT CEGB RES, V10, P13 FLATLEY T, 1988, WERKST KORROS, V39, P84 GRABKE HJ, 1987, MATER SCI ENG, V87, P23 HARADA Y, 1972, CORROSION, P841 KIHARA S, 1988, WERKST KORROS, V39, P69 LOPEZ D, 1993, CORROSION 93 HOUST T LOPEZ D, 1994, CORROSION 94 HOUST T LOPEZ, 1994, DCORROSION 95 HOUST LOPEZLOPEZ D, 1989, P 10 INT C MAT TECHN LOPEZLOPEZ D, 1993, CORROS SCI, V35, P1151 LOPEZLOPEZ D, 1994, THESIS U NACL AUTONO LOPEZLOPEZ D, 1998, CORROSION 98 HOUST T MCCOY, 1965, CORROSION, V21, P84 MCKEE DW, 1973, METALL T, V4, P1877 RAHMEL A, 1963, P C MECH CORR FUEL I RAO YK, 1982, CARBON, V20, P207 SEDOR P, 1960, J ENG POWER, P181 SMITH AF, 1981, WERKST KORROS, V32, P1 WILSON JR, 1976, CORROSION 76 HOUST T WONGMORENO A, 1994, CORROSION 94 HOUST T NR 24 TC 1 PU WILEY-V C H VERLAG GMBH PI BERLIN PA MUHLENSTRASSE 33-34, D-13187 BERLIN, GERMANY SN 0947-5117 J9 MATER CORROS JI Mater. Corros. PD APR PY 1998 VL 49 IS 4 BP 272 EP 277 PG 6 SC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering GA ZK609 UT ISI:000073342300010 ER PT J AU Martinez-Villafane, A Almeraya-Calderon, MF Gaona-Tiburcio, C Gonzalez-Rodriguez, JG Porcayo-Calderon, J TI High-temperature degradation and protection of ferritic and austenitic steels in steam generators SO JOURNAL OF MATERIALS ENGINEERING AND PERFORMANCE LA English DT Article DE corrosion by deposits; creep resistance; metallic coatings; power plant; reheater ID CORROSION; COATINGS AB The useful life of superheaters and reheaters of power stations which use heavy fuel oil is shortened and their continuous service is inhibited by corrosion (fireside) and creep-type problems, The increase of corrosion attack on boilers is caused by the presence of fuel ash deposits containing mainly vanadium, sodium, and sulfur which form low-melting-point compounds, The tubes are exposed to the action of high stresses and high temperatures, producing the so-called "creep damage." In this work, two kinds of results are reported: lab and field studies using a 2.25Cr-1Mo steel. The laboratory work was in turn divided into two parts, In the first, the steel was exposed to the action of natural ash deposits in oxidant atmospheres at 600 degrees C for 24 h, In the second part, tensile specimens were creep tested in Na2SO4, V2O5, and their mixture over a temperature range of 580 to 620 degrees C, In the field work, components of a power station were coated with different types of nickel-and iron-base coatings containing chromium, Fe-Cr, and Fe-Si using the powder flame spraying technique, After testing, the coated tubes were analyzed using electron microscopy. The results showed that all the coating systems had good corrosion resistance, especially those containing silicon or chromium. C1 Ctr Invest Mat Avanzados, Dept Corros, Chihuahua 31109, Mexico. Univ Autonoma Estado Morelos, Coordinac Posgrad, Cuernavaca, Morelos, Mexico. Inst Invest Elect, Dept Sistemas Combust, Temixco, Morelos, Mexico. RP Martinez-Villafane, A, Ctr Invest Mat Avanzados, Dept Corros, Miguel Cervantes 120,Complejo Ind Chihuahua, Chihuahua 31109, Mexico. CR 1988, AP5826 EPRI, V2 AHILA S, 1993, INDIAN I MET, P215 ARROYOFIGUEROA G, 1988, THESIS TECNOLOGICO C GONZALEZRODRIGU.JG, 1995, CORR 95 HOUST HARADA Y, 1972, CORROSION, P841 MARTINEZVILAFAN.A, 1989, ADV CHEM ENG, V2, P799 MEADOWCROFT DB, 1987, MATER SCI ENG, V88, P313 PAUL LD, 1991, CORROSION, V47, P152 PERAZA A, 1989, GS6459S EPRI REICHEL HH, 1988, WERKST KORROS, V39, P54 SIVAKUMAR R, 1989, SURF COAT TECH, V37, P139 STOTT FH, 1989, MATER SCI TECH SER, V5, P734 NR 12 TC 3 PU ASM INTERNATIONAL PI MATERIALS PARK PA SUBSCRIPTIONS SPECIALIST CUSTOMER SERVICE, MATERIALS PARK, OH 44073-0002 USA SN 1059-9495 J9 J MATER ENG PERFORM JI J. Mater. Eng. Perform. PD FEB PY 1998 VL 7 IS 1 BP 108 EP 113 PG 6 SC Materials Science, Multidisciplinary GA YW196 UT ISI:000071908100014 ER PT J AU Barragan, RM Arellano, VM Heard, CL Best, R TI Experimental performance of ternary solutions in an absorption heat transformer SO INTERNATIONAL JOURNAL OF ENERGY RESEARCH LA English DT Article DE heat transformer; absorption systems; ternary solutions ID CHLORIDE SYSTEM AB In this work, results from experiments with ternary solutions in an absorption heat transformer are presented. The experiments were performed under controlled conditions using water/lithium chloride/zinc chloride and water/calcium chloride/zinc chloride solutions as working pairs. The results showed that the gross temperature lift is increased with regard to the results obtained using binary solutions because the concentration of the solutions was enhanced. The water/lithium chloride/zinc chloride solution showed a generally better performance than the water/calcium chloride/zinc chloride mixture. The highest gross temperature lift for the former solution was 37.5 degrees C for an absorber temperature of 96 degrees C. This result compared favourably to that previously obtained for water/lithium bromide in the University of Salford. (C) 1998 John Wiley & Sons, Ltd. C1 Inst Invest Elect, Unidad Geotermia, Cuernavaca 62000, Morelos, Mexico. RP Barragan, RM, Inst Invest Elect, Unidad Geotermia, POB 475, Cuernavaca 62000, Morelos, Mexico. CR AYALA R, 1995, THESIS U SALFORD UK BARRAGAN RM, 1995, INT J ENERG RES, V19, P593 BARRAGAN RM, 1996, IN PRESS INT J ENERG BARRAGAN RM, 1996, INT J ENERG RES, V20, P651 BEST R, 1990, EXPT STUDY HEAT DRIV BEST R, 1994, HEAT RECOV SYST CHP, V14, P427 DUARTE SIP, 1989, HEAT RECOVERY SYSTEM, V9, P521 EISA MAR, 1987, HEAT RECOVERY SYSTEM, V7, P107 HEROLD KE, 1991, INT J REFRIG, V14, P156 IYOKI S, 1989, INT J REFRIG, V13, P191 RIVERA W, 1995, P 19 INT C REFR, P1227 SIDDIGMOHAMMED BE, 1983, CHEM ENG RES DES, V61, P283 UEMURA T, 1982, P JAP ASS REFR ANN C WEAST RC, 1970, HDB CHEM PHYSICS NR 14 TC 4 PU JOHN WILEY & SONS LTD PI W SUSSEX PA BAFFINS LANE CHICHESTER, W SUSSEX PO19 1UD, ENGLAND SN 0363-907X J9 INT J ENERG RES JI Int. J. Energy Res. PD JAN PY 1998 VL 22 IS 1 BP 73 EP 83 PG 11 SC Energy & Fuels; Nuclear Science & Technology GA YT724 UT ISI:000071636600006 ER PT J AU Sanchez-Vazquez, ML Reyes, R Ramirez, G Merchant-Larios, H Rosado, A Delgado, NM TI DNA unpacking in guinea pig sperm chromatin by heparin and reduced glutathione SO ARCHIVES OF ANDROLOGY LA English DT Article DE acridine orange; chromatin; ethidium bromide; heparin; histone; protamine; reduced glutathione ID GLYCOSAMINEGLYCAN-SULFATE; SPERMATOZOA NUCLEI; BOVINE SPERMATOZOA; MAMMALIAN SPERM; EGG EXTRACTS; DECONDENSATION; INVITRO; MOUSE; RAT; PHOSPHORYLATION AB The kinetics of nuclear decondensation and DNA unpacking induced by the action of a physiological concentration of heparin and glutathione of guinea pig spermatozoa was studied. Sperm (acrosomeless) suspensions were incubated ar several different temperatures (37, 40, 43, and 46 degrees C), with a constant concentration of either heparin (50 mu M) or reduced glutathione (12.5 mM) and increasing concentrations of the other reagent. Nuclei spermatozoa remained highly condensed when incubated in the medium alone or in either GSH or heparin alone for up to 72 h. Swelling of nuclei spermatozoa was initially observed during the first 20 min of incubation. The sperm nuclei initiate decompaction at the central part of the nuclear structure while at the periphery there remain numerous residues of densely packed chromatin. The swollen chromatin pattern presents the characteristic organization into "hub-like" nuclear bodies that measured 10-100 nm diameter joined by a network of chromatin fibers. At full nuclei decondensation chromatin end fibers are loose, probably meaning that DNA is not organized into loop domains. DNA presence was verified by the use of ethidium bromide and acridine orange. C1 Ctr Invest Biomed Sur IMSS, Xochitepec 62790, Morelos, Mexico. Natl Autonomous Univ Mexico, Inst Invest Biomed, Dept Biol Desarrollo, Mexico City 04510, DF, Mexico. UAM Iztapalapa, Dept Reprod Biol, Div Ciencias Biol & Salud, Mexico City, DF, Mexico. RP Sanchez-Vazquez, ML, Ctr Invest Biomed Sur IMSS, Argentina 1,Apdo,Postal 25, Xochitepec 62790, Morelos, Mexico. CR BALHORN R, 1982, J CELL BIOL, V93, P298 CALVIN HI, 1976, BIOCHIM BIOPHYS ACTA, V434, P377 CARRANCO A, 1983, ARCH ANDROLOGY, V10, P213 COLLAS P, 1995, EXP CELL RES, V219, P687 DELGADO NM, 1980, ARCH ANDROLOGY, V4, P305 DELGADO NM, 1982, J EXP ZOOL, V224, P457 DERCHIA AM, 1996, NATURE, V381, P597 DIMITROV S, 1994, J CELL BIOL, V126, P591 DOBRINSKI I, 1994, J REPROD FERTIL, V101, P531 DONTHART RJ, 1973, BIOCHEMISTRY-US, V12, P214 DOZORTSEV D, 1995, HUM REPROD, V10, P2960 JAGER S, 1990, J EXP ZOOL, V256, P315 JAMIL K, 1984, ARCH ANDROLOGY, V13, P137 KEYHANI E, 1973, BIOCHIM BIOPHYS ACTA, V305, P557 KOEHLER JK, 1983, GAMETE RES, V8, P357 KOLLER CA, 1983, NUCLEI ACID RES, V21, P2952 LASKEY RA, 1978, NATURE, V275, P416 LEE CN, 1986, J ANIM SCI, V63, P861 LENZ RW, 1983, BIOL REPROD, V28, P683 LEPECQ JB, 1967, J MOL BIOL, V27, P87 LUFT JH, 1961, J BIOPHYS BIOCH CYTO, V9, P409 MONTAG M, 1992, MOL REPROD DEV, V33, P338 POGANY GC, 1981, EXP CELL RES, V136, P127 REYES R, 1984, ARCH ANDROLOGY, V12, P203 REYES R, 1989, GAMETE RES, V23, P30 REYES R, 1991, ARCH ANDROLOGY, V26, P53 REYNOLDS ES, 1963, J CELL BIOL, V17, P208 SANCHEZVAZQUEZ ML, 1996, ARCH ANDROLOGY, V36, P161 SWAN MA, 1993, BIOL REPROD, V48, P987 TAKASUGA Y, 1995, EXP CELL RES, V217, P378 TEJADA RI, 1984, FERTIL STERIL, V42, P87 VALENCIA A, 1984, ARCH ANDROL S, V12, P109 VOGELSTEIN B, 1980, CELL, V22, P79 WARD WS, 1993, BIOL REPROD, V48, P1193 YOSHIDA M, 1993, MOL REPROD DEV, V35, P76 ZETTERQVIST H, 1956, THESIS KAROLINSKA I NR 36 TC 5 PU HEMISPHERE PUBL CORP PI BRISTOL PA 1900 FROST ROAD, SUITE 101, BRISTOL, PA 19007-1598 USA SN 0148-5016 J9 ARCH ANDROLOGY JI Arch. Androl. PD JAN-FEB PY 1998 VL 40 IS 1 BP 15 EP 28 PG 14 SC Andrology GA YR477 UT ISI:000071499200002 ER PT J AU Calixto, ME Sebastian, PJ TI CuInSe2 thin films formed by selenization of Cu-In precursors SO JOURNAL OF MATERIALS SCIENCE LA English DT Article ID SOLAR-CELLS; SE VAPOR; DEPOSITION; LAYERS AB CulnSe(2) (CIS) thin films were grown by selenization of electro-deposited or electroless-deposited Cu-In precursors. Cu-In precursors were formed by layer-by-layer electrodeposition of Cu and In as well as by electroless co-deposition of Cu and In. The major phases in the precursors were found to be Cu11In9 and elemental In. It was found that the stoichiometric CIS phase (CuInSe2) may be formed by selenization of the precursors at temperatures higher than 500 degrees C. The Cu-In precursors as well as CIS films were characterized by X-ray diffraction and scanning electron microscopy. The cubic CIS phase was formed when electroless-deposited Cu-In precursor was selenized, whereas the chalcopyrite CIS or the In-rich phase (CuIn2Se3.5) was formed when the layered precursors were selenized at a high temperature. C1 Univ Nacl Autonoma Mexico, Inst Invest Mat, Lab Energia Solar, Temixco 62580, Morelos, Mexico. RP Sebastian, PJ, Univ Nacl Autonoma Mexico, Inst Invest Mat, Lab Energia Solar, Temixco 62580, Morelos, Mexico. CR *JOINT COMM POWD D, POWD DIFFR FIL CATALAN A, 1994, P 1 WORLD C PHOT EN, P52 FERNANDEZ AM, 1997, THIN SOLID FILMS, V298, P92 GARG JC, 1988, THIN SOLID FILMS, V164, P269 GUPTA A, 1994, SOL ENERG MAT SOL C, V32, P137 JONES PA, 1994, THIN SOLID FILMS, V238, P4 KUMAR SR, 1992, SOL ENERG MAT SOL C, V26, P149 LAKSHMIKUMAR ST, 1994, SOL ENERG MAT SOL C, V32, P7 LINCOT D, 1994, P 1 WORLD C PHOT EN, P136 MICKELSEN RA, 1982, P 16 IEEE PHOT SPEC, P781 MOONEY GD, 1991, APPL PHYS LETT, V58, P2678 PAL R, 1994, SOL ENERG MAT SOL C, V33, P241 PERN FJ, 1991, THIN SOLID FILMS, V202, P299 RUSSEL TWF, 1994, P 1 WORLD C PHOT EN, P238 SACHAN V, 1993, SOL ENERG MAT SOL C, V30, P147 SANCHEZ A, 1995, SEMICOND SCI TECH, V10, P87 SEBASTIAN PJ, 1995, SOL ENERG MAT SOL C, V39, P55 SUBRAMANIAN PR, 1989, B ALLOY PHASE DIAGR, V10, P554 TUTTLE JR, 1993, P 7 SUNSH PROJ THIN VARELA M, 1986, J PHYS D APPL PHYS, V19, P127 WAGNER S, 1974, APPL PHYS LETT, V25, P434 YAMANAKA S, 1993, P 23 IEEE PHOT SPEC NR 22 TC 11 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0022-2461 J9 J MATER SCI JI J. Mater. Sci. PD JAN 15 PY 1998 VL 33 IS 2 BP 339 EP 345 PG 7 SC Materials Science, Multidisciplinary GA YQ005 UT ISI:000071337900007 ER PT J AU Ponce-Palafox, J Martinez-Palacios, CA Ross, LG TI The effects of salinity and temperature on the growth and survival rates of juvenile white shrimp, Penaeus vannamei, Boone, 1931 SO AQUACULTURE LA English DT Article DE shrimp; Penaeus vannamei; growth; salinity; temperature AB The growth and survival of Penaeus vannamei postlarvae was measured at temperatures of 20, 25, 30 and 35 degrees C and salinities of 20, 30, 35, 40 and 50 parts per thousand. Groups of 30 animals were used in each combination of conditions, in triplicate, The results clearly show that juveniles of this species have their best survival between temperatures of 20 and 30 degrees C and salinities above 20 parts per thousand. Best growth was obtained between temperatures of 25 and 35 degrees C, with little difference being noted among salinities. Survival and growth coincide best at around 28 to 30 degrees C and 33 to 40 parts per thousand. Calculated overall production was shown to be best in these conditions. The results demonstrate a high coincidence between the experimentally determined optimum conditions for production and the prevailing conditions in the coastal environment from which the animals originated. (C) 1997 Elsevier Science B.V. C1 Ctr Invest Alimentac & Desarrollo, Unidad Mazatlan, Sinaloa, Mexico. Univ Autonoma Estado Morelos, Cuernavaca, Morelos, Mexico. Univ Stirling, Inst Aquaculture, Stirling FK9 4LA, Scotland. RP Ponce-Palafox, J, Ctr Invest Alimentac & Desarrollo, Unidad Mazatlan, P Box Mazatlan, Sinaloa, Mexico. CR *FAO, 1994, 815 FAO BARTLETT P, 1990, WORLD AQUACULTURE, V90 BASSANESI AT, 1982, THESIS U NACL AUTONO BRAY WA, 1994, AQUACULTURE, V122, P133 HUANG HJ, 1983, THESIS TEXAS A M U C LESTER LJ, 1991, MARINE SHRIMP CULTUR, V23, P515 MOTOH H, 1981, 7 SEAFDEC AQ DEP RICKER WE, 1975, FISHERIES RES BOARD, V191, P382 ROSENBERRY R, 1993, AQUACULTURE DIGE DEC, P52 VENKATARAMAIAH A, 1974, H742 GULF COAST RES, P134 WYBAN J, 1995, AQUACULTURE, V138, P267 ZEINELDIN ZP, 1965, BIOL BULL, V129, P199 ZEINELDIN ZP, 1966, BIOL BULL, V131, P186 NR 13 TC 30 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0044-8486 J9 AQUACULTURE JI Aquaculture PD NOV 15 PY 1997 VL 157 IS 1-2 BP 107 EP 115 PG 9 SC Fisheries; Marine & Freshwater Biology GA YM520 UT ISI:000071073000009 ER PT J AU Nieva, D Verma, MP Santoyo, E Portugal, E Campos, A TI Geochemical exploration of the Chipilapa geothermal field, El Salvador SO GEOTHERMICS LA English DT Article DE geochemistry; modeling; Chipilapa; Ahuachapan; El Salvador ID EQUILIBRIA; SYSTEMS; WATERS AB Results of the geochemical exploration of the Ahuachapan-Chipilapa area are presented, The procedure for interpreting the chemical composition of very dilute thermal waters is emphasized. Three groups of thermal waters are described, two with a geothermal brine component and one resulting from steam condensation. The model for one of the groups (Type 2) leads to predictions of temperature and chloride concentration that are reasonably close to those of the geothermal liquid feeding Chipilapa well CH-7B. In particular, it was predicted correctly that the salinities in the Chipilapa area would be considerably lower than those in the Ahuachapan field. It is shown that the simultaneous modelling of the carbon dioxide concentration and isotopic composition of fumarole steam allows discrimination between primary and secondary steam. The composition of all fumarole samples is described as steam originating from a single reservoir fluid at 250 degrees C, and composition delta(18)O=-4.1 delta D=-46, CO2=5 x 10(-5) molar fraction. The total discharge composition of CH-7B confirms the trend observed in the Ahuachapan held of decreasing reservoir salinities towards the east. Postulating the existence of a ''deep'' reservoir brine in the eastern (Chipilapa) section of the system, with lower salinity but otherwise similar temperature and isotopic composition to the Ahuachapan brine, allows for the generation of relatively simple models that explain the formation of the CH-7B brine, and the three groups of thermal waters, Type 1 waters are noteworthy in the sense that they result from a ternary mixture of meteoric water, geothermal brine and high-temperature steam condensate,The possibility that the east-west trend in salinity results from a process of dilution of brine with condensate from steam separated at very high temperatures is discussed. The distribution of the different types of hydrothermal manifestations delineates a lateral discharge system, with the steam upflow zone to the south of the study area, on the northern slope of the volcanic range, and thermal water discharges several kilometers to the north, It is deemed reasonable that exploratory drilling should be directed towards the southern edge of the geothermal system, as far as topography and the indicators of probable secondary permeability permit. (C) 1997 CNR. Published by Elsevier Science Ltd. C1 COMIS EJECUT HIDROELECT RIO LEMPA,SANTA TECLA,EL SALVADOR. RP Nieva, D, INST INVEST ELECT,APARTADO POSTAL 475,CUERNAVACA,MORELOS,MEXICO. CR *CEL, 1983, 1 CEL *CEL, 1983, 2 CEL *CEL, 1986, ELS800201 CEL *CEL, 1986, REP GEOQ CAMP CHIP ARNORSSON S, 1985, GEOCHIM COSMOCHIM AC, V49, P1307 DAMORE F, 1980, GEOCHIM COSMOCHIM AC, V44, P549 FOURNIER RO, 1973, GEOCHIM COSMOCHIM AC, V37, P515 FOURNIER RO, 1979, GEOCHIM COSMOCHIM AC, V43, P1543 FOURNIER RO, 1979, GEOTHERM RESOUR COUN, V3, P221 FOURNIER RO, 1982, GEOCHIM COSMOCHIM AC, V46, P1969 FOURNIER RO, 1982, GEOTHERMAL RES COUNC, V11, P3 GARDUNO MV, 1992, GEOTHERMAL RESOURCES, V16, P297 GIGGENBACH WF, 1980, GEOCHIM COSMOCHIM AC, V44, P2021 GIGGENBACH WF, 1982, GEOTHERMICS, V11, P71 GIGGENBACH WF, 1988, GEOCHIM COSMOCHIM AC, V52, P2749 GIGGENBACH WF, 1992, EARTH PLANET SC LETT, V113, P495 GIGGENBACH WF, 1992, P FIN RES COORD M SA, P201 NIEVA D, 1987, HEAT RECOVERY SYSTEM, V7, P243 NIEVA D, 1990, SINTESIS INFORMACION NIEVA D, 1992, INFORME FINAL ESTUDI NIEVA D, 1993, INFORME FINAL SINTES PARTIDA EG, 1997, GEOTHERMICS, V26, P555 ROMO JM, 1997, GEOTHERMICS, V26, P627 STEWART MK, 1990, ENV ISOTOPE STUDY AH TRUESDELL AH, 1976, 76428 US GEOL SURV TRUESDELL AH, 1977, J GEOPHYS RES, V82, P3694 TRUESDELL AH, 1977, J RES US GEOL SURV, V5, P49 TRUESDELL AH, 1989, P 14 WORKSH GEOTH RE, P273 NR 28 TC 8 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0375-6505 J9 GEOTHERMICS JI Geothermics PD OCT-DEC PY 1997 VL 26 IS 5-6 BP 589 EP 612 PG 24 SC Energy & Fuels; Geosciences, Multidisciplinary GA YJ436 UT ISI:A1997YJ43600004 ER PT J AU Partida, EG Gutierrez, AG Rodriguez, VT TI Thermal and petrologic study of the Ch-A well from the Chipilapa-Ahuachapan geothermal area, El Salvador SO GEOTHERMICS LA English DT Article DE hydrothermal alteration; fluid inclusions; stabilized temperatures; homogenization temperatures AB Systematic petrological studies were performed at 10-m intervals along the 2700-m-deep Ch-A well. Results show mineralogical variations that define four zones which, in turn, represent different thermal zones. The shallowest zone (Zone 1) is characterized by the presence of chalcedony + zeolites + amorphous silica + saponite + montmorillonite + minor amounts of pyrite and calcite; Zone 2 by chlorite + quartz + smectite + zeolites; Zone 3 by chlorite + quartz + calcite + epidote + abundant pyrite and hematite + mixed-layered illite-smectite + chalcopyrite; and Zone 4 by epidote + clinozoisite + gypsum + sericite + mixed-layered chlorite-illite-smectite + anyhdrite. Fluid inclusion analyses performed at 100-m intervals indicate that a low-to-moderate salinity fluid with ice-melting temperatures of -0.7 to -2.2 degrees C was involved in the hydrothermal alteration of the rocks. At shallow depths, positive values of +1.6 degrees C were found,which probably indicate an increase in volatile components. Minimum homogenization temperatures gradually increased with depth. They range from 110 degrees C at very shallow depths (153m) to 244 degrees C at total depth (2700m); however, peak or maximum temperatures of 265-286 degrees C are found at various depths between 1400 and 2500m. Bottom-hole fluid inclusion temperatures agree well with static temperatures derived from the Horner (1951) and the Ascencio el al. (1994) methods. Comparisons at other depths show that, in general, Horner temperatures are the lowest and that fluid inclusion temperatures are the highest, except at about 1200m depth where the Ascencio et al. (1994) method gives the largest values. It is believed that well CBA encountered a mineral paragenesis that does not correspond with present thermodynamic conditions of the reservoir and that the geothermal system has undergone natural cooling. (C) 1997 CNR. Published by Elsevier Science Ltd. RP Partida, EG, INST INVEST ELECT,AP 1-475,CUERNAVACA 62001,MORELOS,MEXICO. CR ARNORSSON S, 1981, J PETROL TECHNOL, V33, P181 ASCENCIO F, 1994, GEOTHERMICS, V23, P317 AUMENTO F, 1982, GEOTHERMAL RESOURCES, V6, P7 AUNZO Z, 1991, GEOTHERMICS, V20, P1 BIRD DK, 1984, ECON GEOL, V79, P671 BROWNE P, 1984, LECT GEOTHERMAL GEOL BROWNE PRL, 1970, GEOTHERMICS, V2, P564 BROWNE PRL, 1978, ANN REV EARTH PLANET, V6, P229 CATHELINEAU M, 1985, GEOTHERMICS, V14, P49 ELDERS W, 1977, GEOTHERMAL RESOURCES, V1, P85 GOMEZ DN, 1993, SGCIF001 I INV EL HAAS JL, 1971, ECON GEOL, V66, P940 HORNER DR, 1951, P 3 WORLD PETR C HAG, P503 IGLESIAS RE, 1995, P WORLD GEOTH C 95 F, V3, P1531 MONTALVO GI, 1989, GEOTERMIA REV MEXICA, V5, P433 NIEVA D, 1997, GEOTHERMICS, V26, P589 PARTIDA EG, 1983, GEOMIMET, V123, P35 PARTIDA EG, 1988, GEOTERMIA REV MEXICA, V4, P107 PARTIDA EG, 1988, GEOTERMIA REV MEXICA, V4, P3 PARTIDA EG, 1990, GEOTERMIA REV MEXICA, V6, P43 PARTIDA EG, 1991, IIE2969I01F I INV EL PARTIDA EG, 1993, REV MEXICANA GEOENER, V9, P241 PARTIDA EG, 1997, GEOTHERMICS, V26, P555 PARTIDA EG, 1997, UNPUB ESTUDIO RELACI POTTER RW, 1978, ECON GEOL, V73, P284 RODRIGUEZ EI, 1993, IIEIRVIF002CO1 CEL C ROMO JM, 1997, GEOTHERMICS, V26, P627 TRUESDELL AH, 1989, P 14 WORKSH GEOTH RE, P273 NR 28 TC 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0375-6505 J9 GEOTHERMICS JI Geothermics PD OCT-DEC PY 1997 VL 26 IS 5-6 BP 701 EP 713 PG 13 SC Energy & Fuels; Geosciences, Multidisciplinary GA YJ436 UT ISI:A1997YJ43600009 ER PT J AU Verma, SP Santoyo, E TI New improved equations for Na/K, Na/Li and SiO2 geothermometers by outlier detection and rejection SO JOURNAL OF VOLCANOLOGY AND GEOTHERMAL RESEARCH LA English DT Article DE geothermometers; geothermal systems; statistical tests; reservoir engineering; geothermal exploration AB We present new improved equations for three still widely used Na/K, Na/Li and SiO2 geothermometers (obtained by statistical treatment of the data and application of outlier detection and rejection as well as theory of error propagation) and compare them with those by Fournier and others. New equations are also developed for estimating errors associated with the use of these new geothermometric equations and comparing them with the performance of the original equations. The errors in the use of the new Na/K equation for temperatures ranging from 80 to 350 degrees C vary from about 19 to 34%, which is lower than the corresponding errors (24-43%) for the original Fournier equation. Similarly, for temperatures ranging from about 50 to 320 degrees C, our new equation for Na/Li geothermometer for Cl < 0.3 m shows errors of about 13-34% as compared to 15-39% for the original equation, and for Cl greater than or equal to 0.3 m, from 10 to 44%, much lower than 26-106% estimated for the corresponding original equation. Finally, for temperatures ranging from 20 to 210 degrees C our results show that the total propagated errors of the new geothermometric equation for SiO2 < 295 ppm are about 1-9%, smaller than 3-12% for the original SiO2 geothermometer. We have proposed a linear equation for the temperature range of 210 to 310 degrees C (SiO2 greater than or equal to 295 ppm), which shows considerably smaller total propagated errors (2-3%) than for the original equation (5-29%). (C) 1997 Elsevier Science B.V. C1 IIE,DEPT GEOTERMIA,CUERNAVACA 62001,MORELOS,MEXICO. RP Verma, SP, UNAM,CTR INVEST ENERGIA,PRIV XOCHICALCO S-NO,COL CTR,APARTADO POSTAL 34,TEMIXCO 62580,MORELOS,MEXICO. CR ABBEY S, 1986, GEOSTANDARD NEWSLETT, V10, P159 ANDRESDOTTIR A, 1995, P WORLD GEOTH C 1995, V2, P1001 ARNORSSON S, 1985, GEOCHIM COSMOCHIM AC, V49, P1307 BARNETT V, 1987, OUTLIERS STATISTICAL BEHENKEN DW, 1972, TECHNOMETRICS, V14, P101 BEVINGTON PR, 1969, DATA REDUCTION ERROR BROOKS C, 1972, REV GEOPHYSICS SPACE, V10, P551 BRYAN WB, 1969, SCIENCE, V163, P926 BUNTEBARTH G, 1984, GEOTHERMICS INTRO ELDERS WA, 1992, WATER ROCK INTERACTI, V2, P1283 FAURE G, 1986, PRINCIPLES ISOTOPE G FAUSTO L, 1979, 2 S CERR PRIET GEOTH, P199 FOUILLAC C, 1981, GEOTHERMICS, V10, P55 FOURNIER RO, 1973, GEOCHIM COSMOCHIM AC, V37, P1255 FOURNIER RO, 1979, GEOCHIM COSMOCHIM AC, V43, P1543 FOURNIER RO, 1979, GEOTHERM RESOUR COUN, V3, P221 FOURNIER RO, 1982, GEOTHERMAL RES COUNC, V11, P3 GIGGENBACH WF, 1995, WORLD GEOTH C 1995 F, V2, P995 GLADNEY ES, 1982, GEOSTANDARD NEWSLETT, V7, P3 GOVINDARAJU K, 1980, GEOSTANDARD NEWSLETT, V4, P49 GUOYING G, 1995, P WORLD GEOTH C 1995, V2, P1213 HUTCHINSON RA, 1992, WATER ROCK INTERACTI, V2, P1419 INGAMELLS CO, 1974, TALANTA LONDON, V21, P141 KLEEMAN AW, 1967, J GEOL SOC AUSTR, V14, P43 LANPHERE MA, 1967, GEOCHIMICA COSMOCHIM, V31, P1091 LOVELOCK B, 1995, P WORLD GEOTH C 1995, V2, P983 LUND RE, 1975, TECHNOMETRICS, V17, P473 MARIKHIN VA, 1993, INT J POLYM MATER, V22, P1 MARINER RH, 1992, WTER ROCK INTERACTIO, V2, P963 NELEY RW, 1984, FLUID MINERAL EQUILI NIEVA D, 1987, HEAT RECOVERY SYSTEM, V7, P243 ROCK NMS, 1987, CHEM GEOL, V66, P163 RUSSELL RD, 1977, CHEM GEOL, V20, P307 SANTOYO E, 1991, ACT FAC CI TIERR UAN, V6, P5 SANTOYO E, 1993, GEOFIS INT, V32, P287 SHEVENELL L, 1995, J VOLCANOL GEOTHRM R, V69, P3 TAYLOR JK, 1990, STAT TECHNIQUES DATA TRUESDELL AH, 1979, 2 S CERR PREIT GEOTH, P224 VELASCO F, 1993, GEOFIS INT, V32, P209 VELASCO F, 1997, IN PRESS MATH GEOL VERMA SP, 1982, J GEOPHYS RES, V87, P838 VERMA SP, 1991, J VOLCANOL GEOTH RES, V47, P105 VERMA SP, 1995, P WORLD GEOTH C 1995, V2, P1119 VERMA SP, 1995, P WORLD GEOTH C 1995, V2, P963 VERMA SP, 1996, GEOFIS INT, V35, P105 VERMA SP, 1996, J C ABSTR, V1, P649 VERMA SP, 1996, J C ABSTRACTS, V1, P650 VERMA SP, 1997, GEOTHERMICS, V26, P25 VERMA SP, 1997, IN PRESS J GEOSTAND, V21 VERMA SP, 1997, UNPUB GEOFFS INT WRIGHT TL, 1970, GEOL SOC AM BULL, V81, P1995 YORK D, 1967, EARTH PLANET SC LETT, V2, P479 YORK D, 1969, EARTH PLANET SC LETT, V5, P320 NR 53 TC 30 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0377-0273 J9 J VOLCANOL GEOTHERM RES JI J. Volcanol. Geotherm. Res. PD OCT PY 1997 VL 79 IS 1-2 BP 9 EP 23 PG 15 SC Geosciences, Multidisciplinary GA YH189 UT ISI:A1997YH18900002 ER PT J AU Torres, LG Jaimes, J Mijaylova, P Ramirez, E Jimenez, B TI Coagulation-flocculation pretreatment of high-load chemical-pharmaceutical industry wastewater: Mixing aspects SO WATER SCIENCE AND TECHNOLOGY LA English DT Article DE coagulation-flocculation; high-load wastewaters; mixing; impellers; pretreatment ID FERMENTATION BROTHS; XANTHAN AB The selection of a coagulant-flocculant agent which, based on the maximum chemical oxygen demand removal, warrants the best performance of the removal system for a very complex high-load chemical-pharmaceutical industry wastewater, is described. A total of 23 coagulants/flocculants was tested, including salts, poly-hidroxyaluminates, synthetic polymers as well as natural gums. In a second stage, some mixing aspects were studied. The effects of the specific impeller, the agitation speed during the coagulation and flocculation stages, and the absence or presence of baffles were evaluated in a six-Place agitation system. The conventional impellers were replaced by the following types of propellers: Rushton, marine, A310 (Lighting), three flat blades, 45 degrees inclined six blades, and conventional flat blade propeller. It was demonstrated that the appropriate coagulation-flocculation system is capable of diminishing the GOD, the apparent color and the dissolved solids up to 40.6, 25.6 and 39.4%, respectively. The best results were observed when using BL-5086, guar gum, Niad II-3, Niad II-4 and locus beam gum. The impeller performance was highly dependent on the agitation speed for each fixed system. With respect to the mixing aspects, it was shown that the selection of the right propeller for the coagulation and flocculation stages is crucial in determining the quality of the treated water, as well as the quantity and quality of the residual sludges generated in the process. (C) 1997 IAWQ. Published by Elsevier Science Ltd. C1 INST MEXICANO TECNOL AGUA,JIUTEPEC 62550,MORELOS,MEXICO. RP Torres, LG, UNIV NACL AUTONOMA MEXICO,INST INGN,APARTADO POSTAL 70-472,MEXICO CITY 04510,DF,MEXICO. CR *APHA AWWA WPCF, 1989, STAND METH EX WAT WA ALBITER V, 1994, PROCESS BIOCHEM, V29, P187 RAMIREZ E, 1994, REDUCTION TOXICITY E SANCHEZ A, 1992, PROCESS BIOCHEM, V27, P351 VELASCO D, 1993, P 3 INT C BIOR BIOPR NR 5 TC 10 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0273-1223 J9 WATER SCI TECHNOL JI Water Sci. Technol. PY 1997 VL 36 IS 2-3 BP 255 EP 262 PG 8 SC Engineering, Environmental; Environmental Sciences; Water Resources GA YG150 UT ISI:A1997YG15000033 ER PT J AU Lemus, R PerezBernal, F Frank, A Bijker, R Arias, JM TI Boson-realization model for the vibrational spectra of tetrahedral molecules - Comment SO PHYSICAL REVIEW A LA English DT Letter AB An algebraic model in terms of a local harmonic boson realization was recently proposed to study molecular vibrational spectra [Zhong-Qi Ma et al., Phys. Rev. A 53, 2173 (1996)]. Because of the local nature of the bosons the model has to deal with spurious degrees of freedom, An approach to eliminate the latter from both the Hamiltonian and the basis was suggested. We show that this procedure does not remove all spurious components from the Hamiltonian and leads to a restricted set of interactions. We then propose a scheme in which the physical Hamiltonian can be systematically constructed up to any order without the need of imposing conditions on its matrix elements. In addition, we show that this scheme corresponds to the harmonic limit of a symmetry-adapted algebraic approach based on u(2) algebras. [S1050-2947(97)03811-0]. C1 UNIV SEVILLA,FAC FIS,DEPT FIS ATOM MOL & NUCL,E-41080 SEVILLE,SPAIN. LAB CUERNAVACA,INST FIS,CUERNAVACA,MORELOS,MEXICO. RP Lemus, R, NATL AUTONOMOUS UNIV MEXICO,INST CIENCIAS NUCL,APARTADO POSTAL 70-543,MEXICO CITY 04510,DF,MEXICO. CR FRANK A, 1996, ANN PHYS-NEW YORK, V252, P211 LEMUS R, CHEMPH9606002 LEMUS R, 1994, J CHEM PHYS, V101, P8321 MA ZQ, 1996, PHYS REV A, V53, P2173 PEREZBERNAL F, IN PRESS J MOL SPECT PEREZBERNAL F, 1996, CHEM PHYS LETT, V258, P301 NR 6 TC 3 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1050-2947 J9 PHYS REV A JI Phys. Rev. A PD NOV PY 1997 VL 56 IS 5 BP 4337 EP 4340 PG 4 SC Optics; Physics, Atomic, Molecular & Chemical GA YF529 UT ISI:A1997YF52900125 ER PT J AU Arenas, OL Nair, MTS Nair, PK TI Chemical bath deposition of ZnS thin films and modification by air annealing SO SEMICONDUCTOR SCIENCE AND TECHNOLOGY LA English DT Article ID LAYER ADSORPTION; CONVERSION; CDS; CUS AB We demonstrate the deposition of ZnS thin films with a thickness of 0.04 to 0.45 mu m at temperatures ranging from 25 to 80 degrees C from chemical baths comprising zinc sulphate, triethanolamine and thioacetamide at pH of about 10. The as-deposited films do not show crystallinity, are very resistive (conductivity 10(-9) Ohm(-1) cm(-1)) and possess no photosensitivity. Annealing of the films in air at 450 to 500 degrees C for 1-2 h leads to partial conversion of the ZnS films to ZnO films. This is accompanied by an increase in the photoconductivity by more than six orders of magnitude. The optical bandgap is > 3.85 eV in the as-prepared films; after annealing in air the value drops to about 3.7 eV. RP Arenas, OL, UNIV NACL AUTONOMA MEXICO,CTR INVEST ENERGIA,DEPT SOLAR ENERGY MAT,TEMIXCO 62580,MORELOS,MEXICO. CR AYLWARD GH, 1974, SI CHEM DATA, P16 BARRETT CS, 1966, STRUCTURE METALS, P155 BRADY GS, 1991, MAT HDB, P927 CHOPRA KL, 1982, PHYS THIN FILMS, V12, P201 DEVORE JR, 1951, J OPT SOC AM, V41, P416 ERICKSSON LJ, 1970, THIN SOLID FILMS, V5, P303 FERNANDEZ AM, 1993, J PHYS D APPL PHYS, V26, P2001 FERNANDEZ AM, 1993, MATER MANUF PROCESS, V8, P535 HODES G, 1987, PHYS REV B, V36, P4215 HUANG L, 1994, J ELECTROCHEM SOC, V141, P2536 JIMENEZGONZALEZ A, 1996, J CRYST GROWTH, V167, P649 LAGOWSKI JJ, 1973, MODERN INORGANIC CHE, P478 LOKHANDE CD, 1991, MATER CHEM PHYS, V27, P1 MADELUNG O, 1992, SEMICONDUCTORS OTHER, P26 MOSKOVITS M, 1990, CHEM PHYSICS ATOMIC, P397 NAIR MTS, 1994, J APPL PHYS, V75, P1557 NAIR PK, 1992, SEMICOND SCI TECH, V7, P239 NAIR PK, 1993, J ELECTROCHEM SOC, V140, P1085 NICOLAU YF, 1990, J ELECTROCHEM SOC, V137, P2915 OHTA S, 1988, THIN SOLID FILMS, V162, P73 ORTON JW, 1982, J APPL PHYS, V53, P1602 PALIK ED, 1985, HDB OPTICAL CONSTANT, P597 PORADA Z, 1986, THIN SOLID FILMS, V145, P75 SZE SM, 1981, PHYSICS SEMICONDUCTO NR 24 TC 23 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL, ENGLAND BS1 6BE SN 0268-1242 J9 SEMICOND SCI TECHNOL JI Semicond. Sci. Technol. PD OCT PY 1997 VL 12 IS 10 BP 1323 EP 1330 PG 8 SC Engineering, Electrical & Electronic; Materials Science, Multidisciplinary; Physics, Condensed Matter GA YB052 UT ISI:A1997YB05200021 ER PT J AU GonzalezPartida, E ArellanoGomez, VM BarraganReyes, RM Birkle, P TorresRodriguez, V TI Geochemical behavior of the thermal springs on the east face of the Nevado del Ruiz volcano SO INGENIERIA HIDRAULICA EN MEXICO LA Spanish DT Article DE geothermal energy fluid geochemistry; Nevado del Ruiz volcano; Colombia AB The Nevado del Ruiz volcano is located in the inner part of the Central Cordilleran belt in Colombia. A significant number of thermal springs is located in its vicinity, causing increasing interests in determining the pos sibilities for the use of this resource for electricity generation. The Macizo Volcanico dei Ruiz represents the superficial manifestation of an active magma chamber with acidic evolution characteristics. The chamber is emplaced in a shallow crustal level with capacity to provide heat to its vicinity The geochemical study showed two independent fluid circulation systems at the Macizo del Ruiz. One of them corresponds to the sulfate water type, which is located N of the volcano. The other system represents the chloride water type, which is located W of the volcano. The thermal springs of the zone consist of mixtures with variable proportions of geothermal water with superficial water. The geothermal water comes from a reservoir with an estimated minimal temperature of 235 degrees C and a silica concentration of 408 mg/kg. The fraction of the hot component for the Botero Londono springs samples was estimated as 0.36. This fact explains the high temperature of these springs. RP GonzalezPartida, E, INST INVEST ELECT,CUERNAVACA,MORELOS,MEXICO. CR ARELLANOGOMEZ V, 1994, INFORME IIE ARNORSSON S, 1985, GEOCHIM COSMOCHIM AC, V49, P1307 EDUARDO P, 1990, J VOLCANOLOGY GEOTHE, V42, P117 FOURNIER RO, 1973, GEOCHIM COSMOCHIM AC, V37, P515 FOURNIER RO, 1979, GEOCHIM COSMOCHIM AC, V43, P1543 FOURNIER RO, 1979, GEOTHERM RESOUR COUN, V3, P221 FOURNIER RO, 1982, GEOCHIM COSMOCHIM AC, V46, P1969 GIGGENBACH WF, 1990, J VOLCANOL GEOTH RES, V42, P13 NIEVAGOMEZ D, 1987, J HEAT RECOV SYST, V7, P243 NR 9 TC 0 PU INSTITUTO MEXICANO TECHNOLOGIAAGUA PI MORELOS PA APARTADO POSTAL 202, MORELOS 62550 CIVAC, MEXICO SN 0186-4076 J9 ING HIDRAUL MEX JI Ing. Hidraul. Mex. PD SEP-DEC PY 1997 VL 12 IS 3 BP 5 EP 13 PG 9 SC Engineering, Civil; Water Resources GA YA006 UT ISI:A1997YA00600001 ER PT J AU Nicho, ME Saniger, JM Ponce, MA Huanosta, A Castano, VM TI Preparation and properties of poly(acrylic acid)-based hybrid compounds SO JOURNAL OF APPLIED POLYMER SCIENCE LA English DT Article ID POLYACRYLIC-ACID; CEMENTS AB Hybrid organic-inorganic materials were prepared by using two different zinc salts and poly(acrylic acid) (PAA). The characterization of the resulting compounds show that polymerlike materials with a decomposition temperature above 673 degrees C can be produced and that the specific zinc salt and synthesis route influence the final properties of these materials. (C) 1997 John Wiley & Sons, Inc. C1 UNAM,INST FIS,QUERETARO 76001,MEXICO. INST INVEST ELECT,CUERNAVACA 6200,MORELOS,MEXICO. UNAM,CTR INSTRUMENTOS,MEXICO CITY,DF,MEXICO. UNAM,INST INVEST MAT,MEXICO CITY,DF,MEXICO. CR BARTON JA, 1975, J DENT RES, V54, P310 BRADEN M, 1974, J DENT RES, V53, P1263 CASTANO VM, IN PRESS ADV POLYM S CASTANO VM, 1993, ADV TOPICS MAT SCI E CRISP S, 1974, J DENT RES, V53, P1414 CRISP S, 1976, J DENT RES, V55, P299 HILL RG, 1991, J MATER SCI, V26, P67 HU H, 1991, MATER LETT, V12, P281 HU H, 1992, THESIS UNAM MEXICO C NAKAMOTO K, 1986, INFRARED RAMAN SPECT NICHO ME, IN PRESS J MAT SYNTH NICHO ME, 1995, THESIS UNAM MEXICO C NICHOLSON JW, 1987, BRIT POLYM J, V19, P67 NICHOLSON JW, 1993, J MATER SCI-MATER M, V4, P32 PADILLA A, 1991, J MATER RES, V6, P2452 PADILLA A, 1992, MATER LETT, V12, P445 PROSSER J, 1983, POLYELECTROL CEMENTS, V1, P217 SANIGER J, 1994, CHARATERIZATION TECH, P169 SANIGER JM, 1992, MATER LETT, V15, P113 SAWABY A, 1990, J APPL POLYM SCI, V39, P1983 SMITH DC, 1968, BR DENT J, V125, P381 SMITH DC, 1971, J CAN DENT ASSOC, V37, P22 NR 22 TC 2 PU JOHN WILEY & SONS INC PI NEW YORK PA 605 THIRD AVE, NEW YORK, NY 10158-0012 SN 0021-8995 J9 J APPL POLYM SCI JI J. Appl. Polym. Sci. PD OCT 31 PY 1997 VL 66 IS 5 BP 861 EP 868 PG 8 SC Polymer Science GA XY765 UT ISI:A1997XY76500006 ER PT J AU GonzalezRodriguez, JG SalinasBravo, VM MartinezVillafane, A TI Hydrogen embrittlement of type 410 stainless steel in sodium chloride, sodium sulfate, and sodium hydroxide environments at 90 degrees C SO CORROSION LA English DT Article DE anodic polarization; cathodic polarization; hydrogen embrittlement; hydrogen permeation; pH; slow strain rate testing; sodium chloride; sodium sulfate; steam turbine; type 410 stainless steel AB Susceptibility of martensitic type 410 (UNS S41000) stainless steel (SSI to environmental cracking was evaluated at 90 degrees C in concentrated sodium chloride (NaCl), sodium sulfate (Na2SO4), and sodium hydroxide (NaOH) solutions, all of which are environments related to steam turbine conditions, using the slow strain rate testing (SSRT) technique. In NaCl, the effects of solution pH, concentration, and anodic and cathodic polarization were investigated. Tests were supplemented by detailed electron fractography and hydrogen permeation measurements, A clear correlation was found between the degree of embrittlement and the amount of hydrogen permeating the steel, suggesting a hydrogen-induced cracking mechanism. C1 DEPT QUIM FIS APLICADA,INST INVEST ELECTR,CUERNAVACA 62001,MORELOS,MEXICO. CTR INVEST MAT AVANZADOS LEON TOLSTOI,CHIHUAHUA,CHIH,MEXICO. CR BERMAN DA, 1974, HYDROGEN METALS, P575 DESANTAMARIA MS, 1989, CORROS SCI, V29, P69 DEVANATHAN MAV, 1964, J ELECTROCHEM SOC, V111, P619 ELSAYED HA, 1981, SURF TECHNOL, V16, P245 ELSAYED HA, 1986, CORROS PREV CONT, V12, P142 GOUDA VK, 1983, SURF TECHNOL, V18, P327 LINDINGER RJ, 1981, CORROSION 81 LYLE FF, 1980, CORROSION 80 SCULLY JC, 1973, STRESS CORROSION CRA, V10, P496 SHALVOY RS, 1981, CORROSION 81 SPACHN H, 1988, ENV INDUCED CRACKING, P449 VISWANATHAN R, 1991, LIFE PREDICTION CORR WEI RP, 1976, SCRIPTA METALL, V10, P153 NR 13 TC 0 PU NATL ASSN CORROSION ENG PI HOUSTON PA 1440 SOUTH CREEK DRIVE, HOUSTON, TX 77084-4906 SN 0010-9312 J9 CORROSION JI Corrosion PD JUN PY 1997 VL 53 IS 6 BP 499 EP 504 PG 6 SC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering GA XU787 UT ISI:A1997XU78700009 ER PT J AU Rai, BK Bist, HD Katiyar, RS Nair, MTS Nair, PK Mannivannan, A TI Simultaneous observation of strong and weak quantum confinement effect in chemically deposited CdSe thin films: A spectro-structural study SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID NONLINEAR OPTICAL-PROPERTIES; GERMANATE GLASS MATRIX; SEMICONDUCTOR CLUSTERS; NANOCRYSTALS; MICROCRYSTALLITES; ASSIGNMENT; ABSORPTION; WURTZITE AB CdSe thin films deposited chemically on glass substrates for 4, 8, and 16 h, and subsequently annealed al 400 degrees C for 1 h, have been studied by a combination of spectroscopic (photoluminescence and Raman scattering) and structure-determining (x-ray diffraction and atomic force microscopy) techniques. Due to a size distribution of constituent grains, photoluminescence spectra of the as-deposited films show weak but broad bands at similar to 2.2 eV (strongly confined band) and similar to 1.73 eV (weakly confined band). On annealing, intensity of the weakly confined band, at similar to 1.7 eV increases as a result of an improvement in the crystalline quality of CdSe nanoclusters. A surface-optic Raman mode at similar to 250 cm(-1) in as-deposited samples has been observed for the first time. The x-ray diffraction studies of annealed samples show II diffraction peak at 2 theta= 13 degrees from the (001) plane. The improvement in crystallinity of the films as observed by atomic force microscopy and photoluminescence techniques, the appearance of (001) reflection in the x-ray diffraction pattern, the disappearance of surface-optic Raman made, and the enhancement of weakly confined band-all as a consequence of annealing-have been discussed and correlated with 1 each. other. A film deposition mechanism has been described, which explains the origin of the simultaneous existence of strong and weak quantum confinement effects; the significance this observation in the development of high efficiency photovoltaic solar cells has been emphasized. (C) 1997 American Institute of Physics. C1 UNIV PUERTO RICO,DEPT PHYS,SAN JUAN,PR 00931. UNIV NACL AUTONOMA MEXICO,IIM,LAB ENERGIA SOLAR,TEMIXCO 62580,MORELOS,MEXICO. UNIV MINNESOTA,DEPT CHEM ENGN & MAT SCI,INST TECHNOL,MINNEAPOLIS,MN 55455. CR *NBS, 1957, 7 NBS, P12 ALPERSON B, 1995, PHYS REV B, V52, P17017 BEREZOVSKII MM, 1996, PHYS SOLID STATE, V38, P358 BRUS L, 1986, J PHYS CHEM-US, V90, P2555 CHAMARRO M, 1996, PHYS REV B, V53, P1336 CHESTNOY N, 1986, J PHYS CHEM-US, V90, P3393 CHOPRA KL, 1983, THIN FILM SOLAR CELL EFROS AL, 1982, FIZ TEKH POLUPROV, V16, P1209 EFROS AL, 1982, SOV PHYS SEMICOND, V16, P772 EKIMOV AI, 1993, J OPT SOC AM B, V10, P100 GARCIAJIMENEZ JM, 1992, J ELECTROCHEM SOC, V139, P2048 GARUTHARA R, 1996, J APPL PHYS, V80, P401 HODES G, 1987, PHYS REV B, V36, P4215 INOKUMA T, 1990, PHYS REV B, V42, P11093 KAGAN CR, 1996, PHYS REV LETT, V76, P1517 KAINTHLA RC, 1980, J ELECTROCHEM SOC, V127, P277 KAINTHLA RC, 1982, J ELECTROCHEM SOC, V129, P99 KLEIN MC, 1990, PHYS REV B, V42, P11123 MARCUS MA, 1991, J PHYS CHEM-US, V95, P1572 MENG JF, 1997, PHYS LETT A, V229, P254 NAIR MTS, 1993, J APPL PHYS, V74, P1879 NORRIS DJ, 1996, PHYS REV B, V53, P16338 NORRIS DJ, 1996, PHYS REV B, V53, P16347 PARK SH, 1990, J OPT SOC AM B, V7, P2097 RAJESHWAR K, 1981, J ELECTROCHEM SOC, V128, P1744 RODRIGUES PAM, 1995, SOLID STATE COMMUN, V94, P583 ROUSSIGNOL P, 1989, PHYS REV LETT, V62, P312 SARMA HP, 1995, PHYS STATUS SOLIDI A, V148, K77 SAVIOT L, 1996, J NON-CRYST SOLIDS, V197, P238 SCAMARCIO G, 1996, PHYS REV B, V53, P10489 SCHMITTRINK S, 1987, PHYS REV B, V35, P8113 SEBASTIAN PJ, 1994, THIN SOLID FILMS, V245, P132 SELVAKUMAR V, 1987, PHYS REV B, V35, P4098 SHAALAN MS, 1990, SOL CELLS, V28, P185 SHIANG JJ, 1995, J PHYS CHEM-US, V99, P17417 TANAKA A, 1992, PHYS REV B, V45, P6587 TOLBERT SH, 1995, J CHEM PHYS, V102, P4642 WANG LW, 1996, PHYS REV B, V53, P9579 NR 38 TC 12 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD AUG 1 PY 1997 VL 82 IS 3 BP 1310 EP 1319 PG 10 SC Physics, Applied GA XP106 UT ISI:A1997XP10600052 ER PT J AU MadrigalMelchor, J PerezRodriguez, F Maytorena, JA Mochan, WL TI An optical spectroscopy for detecting quantized polarization waves of excitons SO APPLIED PHYSICS LETTERS LA English DT Article ID SURFACES; REFLECTIVITY; POLARITONS AB An optical spectroscopy, based upon the determination of the difference between the reflectivity for p-polarized light (R-p) and the squared reflectivity for s-polarized light (R-s(2)) with an angle of incidence of 45 degrees, is proposed to study the interaction of excitons with the surface potential in semiconductors, It is found that R-p - R-s(2) as a function of the wave frequency is quite sensitive to the form of the surface potential. In addition, the generation of longitudinal modes such as the quantized polarization waves of excitons produces resonant dips well-identified in the new spectrum. On the other hand, the transverse resonances present in R-p and R-s disappear in the difference R-p-R-s(2). (C) 1997 American Institute of Physics. C1 UNIV AUTONOMA ESTADO MORELOS,FAC CIENCIAS,CUERNAVACA 62210,MORELOS,MEXICO. UNIV NACL AUTONOMA MEXICO,INST FIS,LAB CUERNAVACA,CUERNAVACA 62191,MORELOS,MEXICO. RP MadrigalMelchor, J, UNIV AUTONOMA PUEBLA,INST FIS,APDO POST J-48,PUEBLA 72570,MEXICO. CR ASPNES DE, 1985, J VAC SCI TECHNOL B, V3, P1498 BALSLEV I, 1981, PHYS REV B, V23, P3977 BATYREV AS, 1993, PHYS SOLID STATE, V35, P1525 BLECKMANN L, 1996, SURF SCI, V351, P277 BURGE DK, 1964, J OPT SOC AM, V54, P1428 DANDREA A, 1982, PHYS REV B, V25, P3714 DELSOLE R, 1991, PHYS REV B, V43, P2136 DELSOLE R, 1995, PHOTONIC PROBES SURF FLORESDESIRENA B, 1994, PHYS REV B, V50, P5404 HALEVI P, 1992, SOV J LOW TEMP PHYS, V18, P795 KISELEV VA, 1986, PHYS STATUS SOLIDI B, V135, P597 MENDOZA BS, 1997, PHYS REV B, V55, P2489 PEREZRODRIGUEZ F, 1992, PHYS REV B, V45, P11854 PEREZRODRIGUEZ F, 1993, PHYS REV B, V48, P2016 PEREZRODRIGUEZ F, 1996, PHYS REV B, V53, P10086 RUPPIN R, 1984, PHYS REV B, V29, P2232 SCHULTHEIS L, 1984, PHYS REV B, V29, P6784 SCHULZ LG, 1954, J OPT SOC AM, V44, P362 NR 18 TC 10 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD JUL 7 PY 1997 VL 71 IS 1 BP 69 EP 71 PG 3 SC Physics, Applied GA XJ139 UT ISI:A1997XJ13900024 ER PT J AU Fernandez, AM Sebastian, PJ Calixto, ME Gamboa, SA Solorza, O TI Characterization of co-electrodeposited and selenized CIS (CuInSe2) thin films SO THIN SOLID FILMS LA English DT Article DE electrical properties and measurements; selenium; structural properties; surface morphology ID SOLAR-CELLS; SE VAPOR; LAYERS; CU AB The structural, morphological, compositional and photoelectrochemical properties of co-electrodeposited and selenized CIS thin films were characterized using various techniques. As-deposited as well as selenized films exhibited a compact or a granular morphology depending on the composition. The film stoichiometry was improved after selenization at 550 degrees C in a tubular furnace, The film conductivity type, carrier concentration and flat-band potential were determined from the photoelectrochemical studies. The films are formed with a mixed composition of the binary as well as the ternary phases. From the results of these studies, a model is suggested for the superficial as well as the bulk conductivity types of the film. (C) 1997 Elsevier Science S.A. C1 UNAM,IIM,LAB ENERGIA SOLAR,PHOTOVOLTA SYST GRP,TEMIXCO 62580,MORELOS,MEXICO. INST POLITECN NACL,CTR INVEST & ESTUDIOS AVANZADOS,DEPT QUIM,MEXICO CITY 07000,DF,MEXICO. CR BHATTACHARYA RN, 1996, J ELECTROCHEM SOC, V143, P854 CATALANO A, 1994, IEEE PHOT SPEC CONF, P52 CONTRERAS MA, 1994, IEEE PHOT SPEC CONF, P68 FERNANDEZ AM, 1996, SEMICOND SCI TECHNOL, V11 GARG JC, 1988, THIN SOLID FILMS, V164, P269 GOMES WP, 1982, PROG SURF SCI, V12, P155 KUMAR SR, 1992, SOL ENERG MAT SOL C, V26, P149 LAKSHMIKUMAR ST, 1994, SOL ENERG MAT SOL C, V32, P7 LINCOT D, 1994, IEEE PHOT SPEC CONF, P136 MICKELSEN RA, 1982, 16TH P IEEE PHOT SPE, P781 MOONEY GD, 1991, APPL PHYS LETT, V58, P2678 PAL R, 1994, SOL ENERG MAT SOL C, V33, P241 PERN FJ, 1991, THIN SOLID FILMS, V202, P299 PHILIP A, 1994, THIN SOLID FILMS, V238, P4 ROCKETT A, 1994, THIN SOLID FILMS, V237, P1 SACHAN V, 1993, SOL ENERG MAT SOL C, V30, P147 SANCHEZ A, 1995, SEMICOND SCI TECH, V10, P87 SEBASTIAN PJ, 1995, SOL ENERG MAT SOL C, V39, P55 VARELA M, 1986, J PHYS D APPL PHYS, V19, P127 WAGNER S, 1974, APPL PHYS LETT, V25, P434 NR 20 TC 9 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0040-6090 J9 THIN SOLID FILMS JI Thin Solid Films PD APR 20 PY 1997 VL 298 IS 1-2 BP 92 EP 97 PG 6 SC Materials Science, Multidisciplinary; Materials Science, Coatings & Films; Physics, Applied; Physics, Condensed Matter GA XH324 UT ISI:A1997XH32400015 ER PT J AU Bautista, A Vergara, A Davila, JV Mariaca, L Gonzalez, JA TI Comparison of electrochemical noise with impedance and polarization resistance techniques in the steel/concrete system SO REVISTA DE METALURGIA LA Spanish DT Article DE electrochemical noise; electrochemical techniques; reinforced concrete; corrosion rate AB This paper studies the corrosion rates of active and passive rebars embedded in concrete in various degrees of wetness using different electrochemical techniques. The ability of the electrochemical noise to quantificate the intensity of the attack and the advantages of this method are stressed. Data that prove that the corrosion rare is proportional to the current noise and independent to the potential noise in this system are also shown. C1 CSIC,CTR NACL INVEST MET,E-28040 MADRID,SPAIN. UNIV NACL INGN,LIMA,PERU. CTR INVEST ELECT,CUERNAVACA,MORELOS,MEXICO. CR BAUMEL A, 1959, ARCH EISENHUTTENWES, V30, P417 BAUTISTA A, 1995, 5 C IB CORR PROT TEN BERTOCCI U, 1995, CORROSION, V51, P131 COTTIS RA, 1990, CORROSION, V46, P12 EDEN DA, 1992, CORROSION 92 GARCIA O, 1995, REV METAL MADRID, V31, P361 GONZALEZ JA, 1974, CORR PROCT, V5, P273 GONZALEZ JA, 1993, CORROSION, V49 GOUDA WK, 1975, CEMENT CONCRETE RES, V5, P1 HARDON RG, 1988, BR CORROS J, V23, P225 HLADKY K, 1982, CORROS SCI, V22, P231 KAESCHE H, 1959, ZEM-KALK-GIPS, V12, P298 LEGAT A, 1995, CORROSION, V51, P295 LUMSDEM JB, 1992, CORROSION 92 MANSFELD F, 1993, J ELECTROCHEM SOC, V140 METIKOSHUKOVIC M, 1989, WERKST KORROS, V40, P494 RAMIREZ E, 1993, BRIT CORROS J, V28, P121 SEARSON PC, 1988, J ELECTROCHEM SOC, V135 STERN M, 1957, J ELECTROCHEMICAL SO, V104, P56 URUCHURTU J, 1991, CORROSION, V47, P472 WENGER F, 1980, INT S BEH OFFSH CONC WENGER F, 1984, 9 INT C MET CORR, V3, P225 XIAO H, 1994, J ELECTROCHEM SOC, V141 NR 23 TC 1 PU CENIM PI MADRID PA AVDA. GREGORIO DEL AMO, 8, 28040 MADRID, SPAIN SN 0034-8570 J9 REV METALURGIA JI Rev. Metal. PD MAR-APR PY 1997 VL 33 IS 2 BP 113 EP 119 PG 7 SC Metallurgy & Metallurgical Engineering GA XE356 UT ISI:A1997XE35600005 ER PT J AU TrujilloJimenez, P DiazPardo, E TI Trophic range of Ilyodon whitei (Pisces: Goodeidae) in Rio del Muerto, Morelos, Mexico SO REVISTA DE BIOLOGIA TROPICAL LA Spanish DT Article DE Ilyodon whitei; Mexico; diet; feeding habits; euryphagous opportunistic species AB The diet and feeding habits of Ilyodon whitei were studied in relation to size, sex and season of the year, by monthly samples taken at Rio Muerto, Morelos, Mexico (18 degrees 29' 32 '' N y 99 degrees 43' 32 '' W). Gut contents were analyzed quantitatively by the numeric and frequency of ocurrence methods, revealing variations in relation to size and season of the year. Small individuals mainly fed on animal matter, while larger individuals preferred plants; in the wet season plant matter dominated, as did animal matter in the dry season. General diet justifies clasification of I. whitei as an euryphagous and opportunistic species since it tends either toward an herbivorous or carnivorous diet according to availability. RP TrujilloJimenez, P, UNIV AUTONOMA ESTADO MORELOS,LAB ICTIOL,AV UNIV 1001 COL CHAMILPA,CUERNAVACA 62210,MORELOS,MEXICO. CR 1970, B HIDROLOGICO, V48 BLAND RG, 1978, HOW KNOW INSECTS CHU HF, 1979, KNOW INMATURE INSECT DELVILLAR JA, 1970, PECES MEXICANOS CLAV DIAZPARDO E, 1986, AN ESC NAC CIENC BIO, V30, P45 DIAZPARDO E, 1989, ZOOLOGIA INFORMA, V14, P33 DUARTE SMP, 1981, THESIS ESCUELA NACL GARCIA ME, 1981, MODIFICACION AL SIST GODINEZ RMA, 1989, THESIS LICENCIATURA KREBS CJ, 1989, ECOLOGICAL METHODOLO LAGLER FK, 1975, FRESHWATER FISHERY B LUDWING JA, 1988, STAT ECOLOGY MARTINEZ TM, 1989, CONTRIBUCION CONOCIM, V2, P49 NEEDHAM JG, 1987, GUIA PARA ESTUDIO SE PENNAK RW, 1978, FRESHWATER INVERTEBR TABOADA SM, 1992, MANUAL TEMPERATURAS NR 16 TC 0 PU REVISTA DE BIOLOGIA TROPICAL PI SAN JOSE PA UNIVERSIDAD DE COSTA RICA CIUDAD UNIVERSITARIA, SAN JOSE, COSTA RICA SN 0034-7744 J9 REV BIOL TROP JI Rev. Biol. Trop. PD AUG PY 1996 VL 44 IS 2B BP 795 EP 801 PG 7 SC Biology GA XD411 UT ISI:A1996XD41100013 ER PT J AU Garcia, VM Nair, MTS Nair, PK Zingaro, RA TI Chemical deposition of bismuth selenide thin films using N,N-dimethylselenourea SO SEMICONDUCTOR SCIENCE AND TECHNOLOGY LA English DT Article ID SULFIDE; BI2SE3; ENHANCEMENT; CRYSTALS; SIZE AB Good quality thin films of bismuth selenide of thickness up to 0.28 mu m were deposited from solutions containing bismuth nitrate, triethanolamine and N,N-dimethylselenourea maintained at temperatures ranging from room temperature to 40 degrees C. X-ray diffraction patterns of the samples annealed at 200 degrees C in air match the standard pattern of hexagonal Bi2Se3 (paraguanajuatite, JCPDS 33-0214). The films exhibit strong optical absorption corresponding to a bandgap of about 1.7-1.41 eV in the as-prepared films. These values decrease to about 1.57-1.06 eV upon annealing the films at 200 degrees C for 1 h in nitrogen. As-deposited, the films show high sheet resistance (similar to 10(12) Omega square(-1)) in the dark. Annealing the films in air or in nitrogen enhances the dark current by about seven orders of magnitude; the resulting dark conductivity is about 10 Omega(-1) cm(-1). This enhancement in conductivity results from improved crystallinity as well as from partial loss of selenium. C1 TEXAS A&M UNIV,DEPT CHEM,COLLEGE STN,TX 77843. RP Garcia, VM, UNIV NACL AUTONOMA MEXICO,IIM,LAB ENERGIA SOLAR,TEMIXCO 62580,MORELOS,MEXICO. CR BARRETT CS, 1966, STRUCTURE METALS, P155 BHATTACHARYA RN, 1982, J ELECTROCHEM SOC, V129, P332 BOYER A, 1991, VIDE COUCHES MINCES, V47, P99 CHOPRA KL, 1982, PHYS THIN FILMS, V12, P201 ESTRADA CA, 1994, J ELECTROCHEM SOC, V141, P802 FOUAD SS, 1994, PHYS STATUS SOLIDI B, V183, P149 GARCIA JC, 1990, MATER RES BULL, V25, P241 GEMINOV VN, 1985, FIZ KHIM OBRABOTKI M, V19, P132 HERMANN AM, 1983, J CRYST GROWTH, V61, P658 HODES G, 1987, PHYS REV B, V36, P4215 HORAK J, 1990, J PHYS CHEM SOLIDS, V51, P1353 HUANG L, 1994, J ELECTROCHEM SOC, V141, P2536 IVANOVA LD, 1992, IAN SSSR NEORG MATER, V28, P759 JACOB JK, 1993, SOLID STATE COMMUN, V85, P879 KAUR I, 1980, J ELECTROCHEM SOC, V127, P943 KITAEV GA, 1965, ZH FIZ KHIM+, V39, P1101 KOCMAN V, 1973, ACTA CRYSTALLOGR B, V29, P2528 LIDE DR, 1990, CRC HDB CHEM PHYSICS, P12 MADELUNG O, 1992, SEMICONDUCTORS OTHER, P51 MICHELETTI FB, 1967, APPL PHYS LETT, V10, P136 MONDAL A, 1983, SOL ENERG MATER, V7, P431 MOSKOVITS M, 1990, CHEM PHYSICS ATOMIC, P397 NAIR MTS, 1990, SEMICOND SCI TECH, V5, P1225 NAIR MTS, 1993, J APPL PHYS, V74, P1879 NAIR MTS, 1993, J ELECTROCHEM SOC, V140, P2988 NAIR PK, 1987, SOL CELLS, V22, P103 NAIR PK, 1991, SEMICOND SCI TECH, V6, P393 NAIR PK, 1993, J ELECTROCHEM SOC, V140, P754 NAIR PK, 1997, IN PRESS J MAT RES, V12 PRAMANIK P, 1980, J ELECTROCHEM SOC, V127, P1857 PRINCE MB, 1954, J APPL PHYS, V26, P534 REGEL LL, 1984, ACTA ASTRONAUT, V11, P155 SOBOLEV VV, 1990, SOV PHYS SEMICOND, V23, P889 STORDEUR M, 1992, PHYS STATUS SOLIDI B, V169, P505 VANDEHULST HC, 1981, LIGHT SCATTERING SMA, P114 ZINGARO RA, 1953, J ORG CHEM, V18, P292 ZINGARO RA, 1964, J ELECTROCHEM SOC, V111, P42 NR 37 TC 30 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL, ENGLAND BS1 6BE SN 0268-1242 J9 SEMICOND SCI TECHNOL JI Semicond. Sci. Technol. PD MAY PY 1997 VL 12 IS 5 BP 645 EP 653 PG 9 SC Engineering, Electrical & Electronic; Materials Science, Multidisciplinary; Physics, Condensed Matter GA WZ130 UT ISI:A1997WZ13000020 ER PT J AU CeaOlivares, R Estrada, MR EspinosaPerez, G Haiduc, I Garcia, PGY LopezCardoso, M LopezVaca, M CoteroVillegas, AM TI 1-oxa-4,6-dithia-5-arsocane and 1,3,6-trithia-2-arsocane dithiocarbamates competition between transannular and exocyclic secondary bonding to arsenic SO MAIN GROUP CHEMISTRY LA English DT Article AB 1-oxa-4,6-dithia-5-arsocane morpholinyldithiocarbamate (1) and 1,3,6-trithia-2-arsocane 2-diethyldithiocarbamate (2) have been prepared by reacting the corresponding sodium dithiocarbamates with 1-oxa-4,6-dithia-5-arsocane or 1,3,6-trithia-2-arsocane. (1) and (2) were characterized by elemental analyses, IR, MS, H-1 and C-13 NMR. The X-ray single-crystal molecular structures of (1) [monoclinic, a = 9.931(5), b = 18.253(5), c = 8.076(3) Angstrom; beta = 92.56(2)degrees; V = 1462.5(7) Angstrom(3); space group P2(1)/c; Z = 4; R = 4.33%] and (2) [monoclinic, a = 7.830(2), b = 10.465(2), c = 19.025(6) Angstrom; beta = 95.82(2)degrees; V = 1550.8(10) Angstrom(3); space group P2(1)/c; Z = 4; R = 3.41%], show that the compounds are monomeric and contain an asymmetric monometallic biconnective dithiocarbamate ligand with a large distortion in the geometry around the As and a weak heterocyclic arsocane transannular secondary interaction. C1 NATL AUTONOMOUS UNIV MEXICO,INST QUIM,MEXICO CITY 04510,DF,MEXICO. UNIV AUTONOMA ESTADO MORELOS,FAC CIENCIAS QUIM,CUERNAVACA,MORELOS,MEXICO. CR ALCOCK NW, ADV INORG CHEM RAD, V172, P15 BALLY R, 1967, ACTA CRYSTALLOGR, V23, P293 CEAOLIVARES R, 1994, J CHEM SOC DA, P2191 COUCOUVANIS D, 1970, PROGR INORG CHEM, V11, P233 COUCOUVANIS D, 1979, PROG INORG CHEM, V26, P301 DRAGER M, 1974, CHEM BER, V107, P2601 DRAGER M, 1975, Z ANORG ALLG CHEM, V411, P79 DRAGER M, 1981, Z ANORG ALLG CHEM, V482, P7 ENGLER R, 1974, Z ANORG ALLG CHEM, V406, P74 ENGLER R, 1974, Z ANORG ALLG CHEM, V407, P35 GLEU K, 1950, ANGEW CHEM, V62, P1950 GUPTA RK, 1985, INORG CHEM, V24, P3280 HAIDUC I, 1981, REV INORG CHEM, V3, P353 RASTON CL, 1975, J CHEM SOC DA, P2425 TIEKINK ERT, 1992, REV INORG CHEM, V12, P183 NR 15 TC 7 PU GORDON BREACH SCI PUBL LTD PI READING PA C/O STBS LTD, PO BOX 90, READING, BERKS, ENGLAND RG1 8JL SN 1024-1221 J9 MAIN GROUP CHEM JI Main Group Chem. PY 1995 VL 1 IS 1 BP 159 EP 164 PG 6 SC Chemistry, Multidisciplinary GA WZ060 UT ISI:A1995WZ06000016 ER PT J AU Rincon, ME Nair, PK TI Low-temperature vapour phase deposition of bismuth sulphide films SO SEMICONDUCTOR SCIENCE AND TECHNOLOGY LA English DT Article ID SULFIDE THIN-FILMS; BI2S3 AB A nearly stoichiometric bismuth sulphide precipitate obtained as a by-product of the chemical deposition technique is used as a source in low-temperature vapour phase deposition of Bi2S3 thin films. At relatively low deposition temperatures (250 degrees C < T < 380 degrees C) highly polycrystalline Bi2S3 films are formed on glass substrates, while very thin films are obtained at lower temperatures (95-250 degrees C). The highest photocurrent (I-ph similar to 10(-4) A) is found in the first group while the highest photosensitivity (S = 56) is found in the amorphous or too thin films. XRD patterns of bismuth sulphide powder before and after 5 h deposition show its enrichment in Si due to the enrichment in S and sulphur-rich bismuth sulphide species (BiS2)(n) of the vapour phase. For films deposited at temperatures in the range of 290-380 degrees C, the change in composition of the source causes different deposition rates and preferential growth of some of the bismuthinite planes (2 theta < 25 degrees for as-deposited powder and 2 theta > 25 degrees for bismuth-rich sources), compositional changes in the films (stratification) does not seem to be relevant at these temperatures. The bandgap (E-g) of the films decreases as the deposition temperature increases from E-g = 2 eV at T-dep = 95-205 degrees C to 1-1.3 eV at T-dep = 290-380 degrees C. Similar results were obtained with different sources, which indicates the stronger dependence of E-g with respect to substrate temperature than with respect to the type of source. RP Rincon, ME, UNIV NACL AUTONOMA MEXICO,LAB ENERGIA SOLAR IIM,PHOTOVOLT SYST GRP,TEMIXCO 62580,MORELOS,MEXICO. CR BARANSKI AS, 1983, J ELECTROCHEM SOC, V130, P2423 BHATTACHARYA RN, 1982, J ELECTROCHEM SOC, V129, P332 BISWAS S, 1986, J ELECTROCHEM SOC, V133, P48 ESCOFFERY CA, 1964, J APPL PHYS, V35, P2273 GILDART L, 1961, J PHYS CHEM SOLIDS, V18, P286 GLATZ AC, 1963, J ELECTROCHEM SOC, V110, P1231 LOFERSKI JJ, 1956, J APPL PHYS, V27, P777 LOKHANDE CD, 1988, J ELECTROCHEM SOC, V135, P1852 LUKOSE J, 1991, SOLID STATE COMMUN, V78, P535 MILLER B, 1976, NATURE, V262, P680 MISRA S, 1994, J APPL PHYS, V75, P4576 NAIR MTS, 1990, SEMICOND SCI TECH, V5, P1225 PAWAR SH, 1984, J MATER SCI LETT, V3, P427 PAWAR SH, 1986, SOL ENERG MATER, V14, P71 PERKOWITZ S, 1993, OPTICAL CHARACTERIZA PRINCE MB, 1955, J APPL PHYS, V26, P534 SILVERMAN MS, 1964, INORG CHEM, V3, P1041 NR 17 TC 9 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL, ENGLAND BS1 6BE SN 0268-1242 J9 SEMICOND SCI TECHNOL JI Semicond. Sci. Technol. PD APR PY 1997 VL 12 IS 4 BP 467 EP 474 PG 8 SC Engineering, Electrical & Electronic; Materials Science, Multidisciplinary; Physics, Condensed Matter GA WV279 UT ISI:A1997WV27900022 ER PT J AU Aida, ICF Martha, LAR Agustin, LM TI Shelf-life of tortilla extended with fungal amylases SO INTERNATIONAL JOURNAL OF FOOD SCIENCE AND TECHNOLOGY LA English DT Article DE corn starch; retrogradation; sensory liking; staling; texture ID BAKED GOODS; CORN; NIXTAMALIZATION; STARCH; MASA AB Corn (maize), the main source of starch and calories in the Mexican diet, is consumed mainly as tortillas, which have a short shelf-life. A fungal alpha-amylase blend (10 mu U g(-1)) was added during hydration of maize flour to produce masa, and modified the starch during tortilla cooking up to the denaturating temperature. Control and treated tortillas, fresh and staled by storage at -12 degrees C and by freeze-thaw cycles, were compared for amounts of retrograded starch, flexibility, rheological properties and by preference ranking by a panel of 75 judges. Results showed significant improvements in delayed staling and, by implication, extended shelf-life. The process was regarded as financially viable on a commercial scale. C1 UNAM,INST BIOTECNOL,CUERNAVACA 62271,MORELOS,MEXICO. UNAM,FAC QUIM,DEPT ALIMENTOS & BIOTECNOL,CUERNAVACA 62271,MORELOS,MEXICO. CR BOYLE PJ, 1990, FOOD TECHNOL-CHICAGO, V44, P129 BRAZEN R, 1990, FOOD REV INT, V6, P225 BRESSANI R, 1958, J AGR FOOD CHEM, V6, P770 FIGUEROA CJ, 1994, AVANCE PERSPECTIVA C, V13, P323 GOMEZ MH, 1989, J FOOD SCI, V54, P330 GOMEZ MH, 1990, STARCH-STARKE, V42, P475 GURAYA HS, 1993, J FOOD SCI, V58, P888 HEBEDA RE, 1990, CEREAL FOOD WORLD, V35, P453 KATZ SH, 1974, SCIENCE, V184, P765 NEWELL GJ, 1987, J FOOD SCI, V52, P1721 PAREDESLOPEZ O, 1982, J FOOD TECHNOL, V17, P687 PAREDESLOPEZ O, 1983, BAKERS DIGEST 0913, P16 PFLUGFELDER RL, 1988, CEREAL CHEM, V65, P262 POMERANZ Y, 1991, FUNCTIONAL PROPERTIE SERNASALDIVAR SO, 1991, CEREAL CHEM, V68, P565 STAUFFER CE, 1989, ENZYNE ASSAYS FOOD S SUMNER JB, 1935, J BIOL CHEM, V108, P51 TREJOGONZALEZ O, 1982, ADV CHEM SERIES, V198 NR 18 TC 0 PU BLACKWELL SCIENCE LTD PI OXFORD PA P O BOX 88, OSNEY MEAD, OXFORD, OXON, ENGLAND OX2 0NE SN 0950-5423 J9 INT J FOOD SCI TECHNOL JI Int. J. Food Sci. Technol. PD DEC PY 1996 VL 31 IS 6 BP 505 EP 509 PG 5 SC Food Science & Technology GA WU982 UT ISI:A1996WU98200005 ER PT J AU JimenezGonzalez, AE TI Modification of ZnO thin films by Ni, Cu, and Cd doping SO JOURNAL OF SOLID STATE CHEMISTRY LA English DT Article ID CHEMICAL-DEPOSITION; POLYCRYSTALLINE; SEMICONDUCTORS AB With the propose of investigating the effect of transition elements in ZnO thin films prepared by the Successive Ion Layer Adsorption and Reaction (SILAR) technique, the deposition solutions were chemically impurified with Ni, Cu, and Cd, as elements of the Ib, IIb, and VIIIa groups, X-ray fluorescence (XRF) analyses confirm that the impurification with Ni and Cu in fact took place but the impurification with Cd did not, while the XRD analyses show that for as prepared and Ni-impurified annealed films, the crystallites are almost oriented along the c axis. The electrical propel ties of the ZnO films were also modified with the impurification, After annealing in air (450 degrees C) the dark conductivity of the films was increased in the case of Ni and Cd impurification up to 1.80x10(-3) and 1.86x10(-2) [Omega cm](-1), respectively, but it decreased drastically in the case of Cu to 5.51 x 10(-7) [Omega cm](-1), as referred to the dark conductivity (1.86 x 10(-4) [Omega cm](-1)) of the pure ZnO sample. The measured activation energy for the electrical conductivity of the modified ZnO thin films is 55 meV for the Ni modification, indicating the existence of donor levels. On the Other hand, the Cu modification increases the activation energy up to 132 meV, which is higher than the activation energy for pure ZnO thin films (98 meV). (C) 1997 Academic Press. RP JimenezGonzalez, AE, UNIV NACL AUTONOMA MEXICO,LAB ENERGIA SOLAR IIM,APARTADO POSTAL 34,TEMIXCO 62580,MORELOS,MEXICO. CR BASOL BM, 1993, ANN REPORT PHOTOVOLT, P7 CHOPRA KL, 1983, THIN FILM SOLAR CELL, P328 CHOPRA KL, 1983, THIN SOLID FILMS, V102, P1 GERGOBIANI AN, 1984, SOV PHYS LEBEDOV I R, V9, P53 HAUFFE K, 1950, Z PHYS CHEM, V196, P160 HEILAND G, 1957, Z PHYS, V148, P15 JIMENEZGONZAILE.AE, 1995, SEMICOND SCI TECH, V10, P1277 JIMENEZGONZALEZ A, 1996, J CRYST GROWTH, V167, P649 JIN ZC, 1987, P SOC PHOTO-OPT INS, V21, P823 KOBAYASHI A, 1983, PHYS REV B, V28, P946 LEHMANN HW, 1973, J APPL PHYS, V44, P3868 MAJOR S, 1986, J MATER RES, V1, P300 MINAMI T, 1984, JPN J APPL PHYS, V23, P280 ORTON JW, 1980, REP PROG PHYS, V43, P1263 ORTON JW, 1982, J APPL PHYS, V53, P1602 PAN HC, 1989, MATER RES SOC S P, V152, P215 RISTOV M, 1985, THIN SOLID FILMS, V123, P63 RISTOV M, 1987, THIN SOLID FILMS, V149, P9 SCHAEFFERT RM, 1980, ELECTROPHOTOGRAPHY, P320 SHANNON RD, 1976, ACTA CRYSTALLOGR A, V32, P751 TOMINAGA K, 1994, THIN SOLID FILMS, V253, P9 WANG RP, 1996, CHEM MATER, V8, P433 ZAVYALOVA LM, 1979, ZH FIZ KHIM, V53, P2125 NR 23 TC 15 PU ACADEMIC PRESS INC JNL-COMP SUBSCRIPTIONS PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 SN 0022-4596 J9 J SOLID STATE CHEM JI J. Solid State Chem. PD FEB 1 PY 1997 VL 128 IS 2 BP 176 EP 180 PG 5 SC Chemistry, Inorganic & Nuclear; Chemistry, Physical GA WT453 UT ISI:A1997WT45300003 ER PT J AU Jose, MV Ruiz, A Bobadilla, JR TI Prevalence of infection, mean worm burden and degree of worm aggregation as determinants of prevalence of disease due to intestinal helminths SO ARCHIVES OF MEDICAL RESEARCH LA English DT Article DE prevalence of disease; prevalence of infection; mean worm burden; degree of worm aggregation; intestinal helminths; Ascaris lumbricoides ID SCHISTOSOMIASIS MANSONI; POPULATION-DYNAMICS; NEMATODE INFECTIONS; MATHEMATICAL-MODELS; CHEMOTHERAPY; COMMUNITY; MORBIDITY; TRICHURIS; INTENSITY; CHILDREN AB Theoretical predictions of disease prevalence due to helminth infections based upon a simple probabilistic model which considers the infection prevalence, the mean worm burden and the degree of worm aggregation are presented. A numerical reappraisal of the likely estimates of the degree of aggregation based upon maximum likelihood estimates of the negative binomial distribution is presented. The prevalence of disease shows a positive relationship with the mean worm burden. This association is hyperbolic when helminth parasites are severely aggregated but is s-shaped when helminth parasites tend to be overdispersed. The prevalence of disease decreases with the degree of worm aggregation when the values of the mean intensity are low; as the mean intensity increases this association becomes positive. The relationship between prevalence of disease and prevalence of infection is hyperbolic for severe degrees of parasite aggregation and is s-shaped for intermediate degrees of aggregation. However, if the mean intensity is low and the degree of aggregation is high there could be a negative relationship between the prevalence of disease and the prevalence of infection. The presence of disease due to helminth parasites is feasible for determined ranges of values of the infection prevalence, mean intensity and the degree of worm clumping. C1 UNIV NACL AUTONOMA MEXICO,INST INVEST BIOMED,MEXICO CITY 04510,DF,MEXICO. INST NACL SALUD PUBL,CUERNAVACA,MORELOS,MEXICO. COLEGIO MEXICO,MEXICO CITY 10740,DF,MEXICO. CR *BANC MUND, 1993, INF DES MUND INV SAL, P222 *WHO, 1987, WHO TECHN REP SER, V749 ANDERSON RM, 1982, NATURE, V297, P557 ANDERSON RM, 1985, ADV PARASIT, V24, P1 ANDERSON RM, 1985, PARASITOLOGY, V90, P629 BLISS CI, 1953, BIOMETRICS, V9, P176 BUNDY DA, 1991, IMMUNOL TODAY, V12, A71 BUNDY DAP, 1989, ADV PARASIT, V28, P107 BUNDY DAP, 1990, T ROY SOC TROP MED H, V84, P115 BUNDY DAP, 1990, T ROY SOC TROP MED H, V84, P622 BUNDY DAP, 1992, WORLD HLTH STATISTIC, V45, P168 CHAN MS, 1994, PARASITOLOGY 3, V109, P373 CHEEVER AW, 1968, AM J TROP MED HYG, V17, P38 COOK JA, 1974, AM J TROP MED HYG, V23, P625 COOPER ES, 1990, EUR J CLIN NUTR, V44, P285 CROMPTON DWT, 1987, PARASITOL TODAY, V3, P123 CROMPTON DWT, 1989, ASCARIASIS ITS PREVE DOUMENGE JP, 1987, ATLAS GLOBAL DISTRIB GILMAN RH, 1983, T ROY SOC TROP MED H, V77, P432 GUYATT HL, 1990, PARASITOLOGY, V101, P139 GUYATT HL, 1991, T ROY SOC TROP MED H, V85, P778 HIATT RA, 1979, J INFECT DIS, V139, P659 JOSE MV, 1989, J MATH BIOL, V27, P707 KLOETZEL K, 1962, AM J TROP MED HYG, V11, P472 LAYRISSE M, 1964, AM J HYG, V79, P279 LEHMAN JS, 1976, AM J TROP MED HYG, V25, P285 LEMLY AD, 1984, J PARASITOL, V70, P466 LWAMBO NJS, 1992, EPIDEMIOL INFECT, V108, P469 MULLER R, 1975, DIS MANUAL MED HELMI NOKES C, 1992, PARASITOLOGY, V104, P539 PACALA SW, 1988, PARASITOLOGY, V96, P197 PAWLOWSKI ZS, 1989, ASCARIASIS ITS PREVE PAWLOWSKI ZS, 1990, TROPICAL GEOGRAPHICA POLLIT E, 1989, UNPUB IMPACT POOR NU PRESCOTT NM, 1987, PARASITOL TODAY, V3, P21 RUIZ A, 1996, SAL PUB MEX, P38 SCOTT ME, 1987, PARASITOLOGY 3, V94, P583 SCRINIVASAN V, 1987, T R SOC TROP MED HYG, V81, P973 SIONGOK TKA, 1976, AM J TROP MED HYG, V25, P273 STEPHENSON LS, 1987, IMPACT HELMINTH INFE STOLL NR, 1925, AM J HYG, V5, P536 STOLL NR, 1947, J PARASITOL, V33, P1 TANNER M, 1989, TROP MED PARASITOL, V40, P207 THEINHLAING, 1991, T R SOC TROP MED HYG, V85, P523 WARREN KS, 1990, TROPICAL GEOGRAPHICA WARREN KS, 1991, LANCET, V338, P686 NR 46 TC 3 PU INST MEXICANO SEGURO PI MEXICO D F PA SOCIAL APDO POSTAL 73-032, MEXICO D F 03020, MEXICO SN 0188-0128 J9 ARCH MED RES JI Arch. Med. Res. PD SPR PY 1997 VL 28 IS 1 BP 121 EP 127 PG 7 SC Medicine, Research & Experimental GA WN843 UT ISI:A1997WN84300021 ER PT J AU TorresSanchez, R MaganaVazquez, A SanchezYanez, JM Gomez, LM TI High temperature microbial corrosion in the condenser of a geothermal electric power unit SO MATERIALS PERFORMANCE LA English DT Article ID BACTERIA AB Field and experimental growth of microbiologically influenced corrosion at high temperatures in a geothermal electric power unit condenser is discussed. Four chambers containing polished and disinfected 304L stainless steel tubes were exposed for two, four, six, and eight months to the condenser environment at temperatures ranging from 150 degrees C at the inlet to 40 degrees C at the outlet. The tubes developed pitting where Desulfotomaculum Nigrificans and Desulfotomaculum Acetoxidans colonies were clearly identified by biochemical tests. There were also some indications of the presence of genus Desulfovibrio and genus Thermodesulfobacterium.(17) The characteristics of pitting were studied employing SEM-EDS techniques and optical microscopy. C1 UNIV MICHOACANA,INST INVEST QUIM BIOL,MORELIA,MICHOACAN,MEXICO. UNAM,INST FIS,CUERNAVACA,MORELOS,MEXICO. RP TorresSanchez, R, UNIV MICHOACANA,INST INVEST MET,MORELIA,MICHOACAN,MEXICO. CR 1994, BERGEYS MANUAL DETER, P337 *NACE, 1994, CORAB AIDA LH, 1991, GEOTERMIA REV MEXICA, V7, P265 BACKWITH TD, 1941, J WAT WKS ASS, V33, P147 BOOTH GH, 1966, BR CORROS J, V1, P345 CARLSON J, 1980, THESIS U ASTON CHEN G, 1995, CORROSION 95 DEMING JW, 1986, MICROBIAL ECOL, V12, P111 DEMPSEY MJ, 1981, MAR BIOL, V61, P305 EDYVEAN RGJ, 1987, INT BIODETERIOR, V23, P199 EDYVEAN RGJ, 1993, MICROBIOLOGICALLY IN, P47 FORD TE, 1986, CORROSION 86 HORVATH J, 1962, MAGY KENM FOLY, V68, P54 KUHR CAH, 1934, WATER, V18, P147 NELSON CM, 1991, APPL ENVIRON MICROB, V12, P3576 OLSEN E, 1950, CORROSION, V6, P405 SADKOWSKI RA, 1995, CORROSION 95 STEIN AA, 1993, MICROBIOLOGICALLY IN, P21 TORRESSANCHEZ R, UNPUB WIDDEL F, 1983, ARCH MICROBIOL, V134, P282 NR 20 TC 6 PU NATL ASSN CORROSION ENG PI HOUSTON PA 1440 SOUTH CREEK DRIVE, HOUSTON, TX 77084-4906 SN 0094-1492 J9 MATER PERFORM JI Mater. Perform. PD MAR PY 1997 VL 36 IS 3 BP 43 EP 46 PG 4 SC Materials Science, Characterization & Testing GA WN451 UT ISI:A1997WN45100015 ER PT J AU Rivera, W Best, R Baker, JN Fletcher, WH Heard, CL Holland, FA TI Mobile pilot-plant for the production of environmentally clean steam SO APPLIED THERMAL ENGINEERING LA English DT Article DE heat recovery; heat transformer; steam compression; lithium bromide/water; technology transfer AB An equipment flow sheet has been developed for a mobile pilot-plant (MPP) to produce environmentally clean steam. The unit consists of a single-stage heat transformer (SSHT) coupled to a mechanical vapour recompression system (MVR) with a nominal output capacity of 260 kg/h of saturated steam at 3 bar absolute pressure for a liquid feed at a temperature of 80 degrees C. It is proposed to have the unit on skids to be transported by a pickup truck or lorry to various industrial locations for demonstration and training purposes, in order to acquaint industrialists with an environmentally clean and energy-efficient technology. Copyright (C) 1997 Elsevier Science Ltd. RP Rivera, W, UNAM,CTR INVEST ENERGIA,APARTADO POSTAL 34,TEMIXCO,MORELOS,MEXICO. CR HUNTLEY WR, 1983, P 18 INT SOC EN CONS, P1921 MASHIMO K, 1987, P IEA HEAT PUMP C CH, P271 MCNEELY LA, 1979, ASHRAE T, V85, P413 PERRY RH, 1984, PERRYS CHEM ENG HDB, P3237 RIVERA W, 1994, HEAT RECOV SYST CHP, V14, P173 RIVERA W, 1996, THESIS U SALFORD UK NR 6 TC 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 1359-4311 J9 APPL THERM ENG JI Appl. Therm. Eng. PD APR PY 1997 VL 17 IS 4 BP 317 EP 326 PG 10 SC Thermodynamics; Energy & Fuels; Engineering, Mechanical; Mechanics GA WL870 UT ISI:A1997WL87000001 ER PT J AU Barragan, RM Arellano, VM Heard, CL Best, R Holland, FA TI Experimental performance of the system water/magnesium chloride in a heat transformer SO INTERNATIONAL JOURNAL OF ENERGY RESEARCH LA English DT Article DE heat transformer; absorption systems; heat recovery ID ABSORPTION AB Absorption heat transformers are devices with the unique capability of raising the temperature of part of a low grade heat source whilst simultaneously rejecting the rest of the heat at a lower temperature. The gross temperature lift that could be attained in the process depends on the characteristics of the working pair. Many combinations of working fluid/absorbent have been proposed although until now the water/lithium bromide system is the most widely used. Experimental results for the water/magnesium chloride working pair in an absorption heat transformer are presented. Two different ranges for the absorber temperature were investigated. The absorber temperature varied from 81 to 89 degrees C and from 91 to 101 degrees C. For the first case, the gross temperature lift was calculated between 7.8 and 10.2 degrees C whilst for the second case the gross temperature lift was found to be between 15 and 18.4 degrees C. For both sets of experiments, the heat input was maintained constant and the calculated coefficient of performance was related to the absorber temperature, the flow ratio and the effectiveness of the economizer. (C) 1997 by John Wiley & Sons, Ltd. RP Barragan, RM, INST INVEST ELECT,DEPT GEOTERMIA,POB 475,CUERNAVACA 62000,MORELOS,MEXICO. CR ADYANTHAYA SD, 1987, THESIS U SALFORD UK ALEFELD G, 1991, P 28 INT C REFR MONT BARRAGAIN RM, 1994, UNPUB INT J ENERGY R BARRAGAIN RRM, 1994, THESIS U SALFORD UK BARRAGAN RM, 1994, UNPUB INT J ENERGY R BEST R, 1990, THESIS U SALFORD UK BRODOWICZ K, 1993, HEAT PUMPS EISA MAR, 1987, HEAT RECOVERY SYSTEM, V7, P107 GEORGE JM, 1989, INT J ENERG RES, V13, P455 IYOKI S, 1990, INT J REFRIG, V13, P191 JERNQVIST A, 1992, HEAT RECOV SYST CHP, V12, P323 PEREIRA SI, 1989, HEAT RECOVERY SYSTEM, V9, P521 RIVERA W, 1994, HEAT RECOV SYST CHP, V14, P173 RIVERA W, 1994, HEAT RECOV SYST CHP, V14, P185 SIDDIGMOHAMMED BE, 1983, CHEM ENG RES DES, V61, P283 SMITH IE, 1990, MANUAL SOBRE TECHNOL, P27 WEAST RC, 1979, HDB CHEM PHYSICS NR 17 TC 0 PU JOHN WILEY & SONS LTD PI W SUSSEX PA BAFFINS LANE CHICHESTER, W SUSSEX, ENGLAND PO19 1UD SN 0363-907X J9 INT J ENERG RES JI Int. J. Energy Res. PD FEB PY 1997 VL 21 IS 2 BP 139 EP 151 PG 13 SC Energy & Fuels; Nuclear Science & Technology GA WK947 UT ISI:A1997WK94700004 ER PT J AU Martinez, H Hernandez, JM TI Single electron capture in low-energy Kr+-He collisions SO CHEMICAL PHYSICS LA English DT Article ID ION-ATOM COLLISIONS; 500 EV-3000 EV; DIFFERENTIAL MEASUREMENTS; EXCITATION TRANSFER; AR; NE+ AB Absolute differential and total cross sections for electron capture have been measured for Kr+ incident on He at impact energies between 1.0 to 5.0 keV and over the laboratory angular range -3 degrees to 3 degrees. The reduced differential cross sections present a maximum at a value of tau approximate to 1.3 keV deg independent of energy. The behaviour of the measured cross sections is compared with a semi-empirical model for near-resonant charge transfer. RP Martinez, H, UNIV NACL AUTONOMA MEXICO,INST FIS,LAB CUERNAVACA,APARTADO POSTAL 48-3,CUERNAVACA 62191,MORELOS,MEXICO. CR BARAT M, 1970, J PHYS B ATOM MOL PH, V3, P230 BAUDON J, 1970, J PHYS B ATOM MOL PH, V3, P207 GERBER G, 1973, J PHYS B ATOM MOL PH, V6, P1836 MARTINEZ H, 1993, NUCL INSTRUM METH B, V82, P389 MARTINEZ H, 1995, CHEM PHYS, V190, P139 MCDANIEL EW, 1989, ATOM COLLISIONS, P652 OLSON RE, 1970, PHYS REV A, V2, P121 SIDIS V, 1975, J PHYS B ATOM MOL PH, V8, P474 SMITH FT, 1966, PHYS REV, V150, P79 SMITH FT, 1967, PHYS REV, V161, P131 SOLANKI R, 1979, APPL PHYS LETT, V35, P317 TSUJI M, 1993, J CHEM PHYS, V98, P8565 TSUJI M, 1993, J CHEM PHYS, V99, P4539 NR 13 TC 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0301-0104 J9 CHEM PHYS JI Chem. Phys. PD FEB 15 PY 1997 VL 215 IS 2 BP 285 EP 289 PG 5 SC Chemistry, Physical; Physics, Atomic, Molecular & Chemical GA WK096 UT ISI:A1997WK09600011 ER PT J AU Calixto, E Sebastian, PJ Fernandez, A TI Electro/electroless deposition and characterization of Cu-In precursors for CIS (CuInSe2) films SO JOURNAL OF CRYSTAL GROWTH LA English DT Article ID THIN-FILMS; SOLAR-CELLS; SELENIZATION; LAYERS AB Cu-In (CI) precursors for growing CuInSe2 (CIS) thin films were deposited and characterized. CI precursors were formed by using electrodeposition and electroless methods. In electrodeposition, CI precursors were formed by sequential deposition of Cu/In and In/Cu. In electroless deposition, the CI precursor was formed by co-deposition. The CI precursors were characterized by using X-ray diffraction (XRD), scanning electron microscopy (SEM) and electron probe microanalysis (EPMA). Initial results on the selenization of the precursors indicated that Cu-m (electroless), Cu/In and In/Cu configurations are suitable for forming device quality CIS films. The major phases in the precursors were found to be Cu11In9 and elemental In, which may lead to the formation of the In-rich CIS phase (CuIn2Se3.5, JCPDS 35-1349) during sintering in argon at lower temperatures. It was found that the stoichiometric CIS phase (CuInSe2, JCPDS 40-1487) is formed by selenization of the precursors at temperatures higher than 500 degrees C. RP Calixto, E, UNAM,IIM,LAB ENERGIA SOLAR,PHOTOVOLTA SYST GRP,TEMIXCO 62580,MORELOS,MEXICO. CR CONTRERAS MA, 1994, IEEE PHOT SPEC CONF, P68 GARG JC, 1988, THIN SOLID FILMS, V164, P269 GUPTA A, 1994, SOL ENERG MAT SOL C, V32, P137 JONES PA, 1994, THIN SOLID FILMS, V238, P4 KUMAR SR, 1992, SOL ENERG MAT SOL C, V26, P149 LAKSHMIKUMAR ST, 1994, SOL ENERG MAT SOL C, V32, P7 PAL R, 1994, SOL ENERG MAT SOL C, V33, P241 PERN FJ, 1991, THIN SOLID FILMS, V202, P299 SACHAN V, 1993, SOL ENERG MAT SOL C, V30, P147 SANCHEZ A, 1995, SEMICOND SCI TECH, V10, P87 SCHUMANN B, 1981, SOV PHYS-CRYSTALLOGR, V26, P678 STOLT L, 1992, P 11 EC PHOT SOL EN SUBRAMANIAN PR, 1989, B ALLOY PHASE DIAGR, V10, P554 TUTTLE JR, 1991, SOL CELLS, V30, P21 TUTTLE JR, 1993, P 7 SUNSH PROJ THIN VARELA M, 1986, J PHYS D APPL PHYS, V19, P127 YAMANAKA S, 1993, P 23 IEEE PVSC LOUIS NR 17 TC 5 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-0248 J9 J CRYST GROWTH JI J. Cryst. Growth PD NOV PY 1996 VL 169 IS 2 BP 287 EP 292 PG 6 SC Crystallography GA VZ056 UT ISI:A1996VZ05600012 ER PT J AU Rincon, ME Nair, PK TI Kinetics of electrical conductivity enhancement in bismuth sulphide thin films .1. Argon and hydrogen annealing SO JOURNAL OF PHYSICS AND CHEMISTRY OF SOLIDS LA English DT Article DE chalcogenides; semiconductors; thin films; electrical conductivity AB The kinetics and mechanisms of conductivity enhancement in low pressure argon and hydrogen annealed bismuth sulphide thin films grown by chemical bath deposition have been studied. Dramatic increase in dark conductivity (sigma) is observed in both cases at annealing temperatures (T) > 230 degrees C (sigma(Ar) = 166 Ohm(-1) cm(-1), sigma(H2) = 205 Ohm(-1) cm(-1)). The normalized saturation rates are equivalent and in the order of 10(4) s(-1) at 300 degrees C. The temperature dependence of the saturation rate is positive in both thermal treatments and is slightly higher for hydrogen annealed films due to the preferential reduction of sulphur. The dark current (l(d)) and excess current under light (Delta l) reach a plateau at around 230 degrees C and both currents decrease substantially at temperatures higher than 400 degrees C. The behavior of the optoelectronic properties of the annealed films with duration and temperature of annealing correlates very well with a multiphase system in which the amorphous phase rich in bismuth rules the behavior of dark conductivity and the crystalline phase (bismuthinite) rules the behavior of Delta l. RP Rincon, ME, UNIV NACL AUTONOMA MEXICO,IIM,PHOTOVOLTA SYST GRP,LAB ENERGIA SOLAR,TEMIXCO 62580,MORELOS,MEXICO. CR BHATTACHARYA RN, 1982, J ELECTROCHEM SOC, V129, P332 BORG RJ, 1992, PHYSICAL CHEM SOLIDS GLATZ AC, 1963, J ELECTROCHEM SOC, V110, P1231 LIN JC, B ALLOY PHASE DIAGRA, P534 NAIR MTS, 1990, SEMICOND SCI TECH, V5, P1225 NAIR PK, 1988, SEMICOND SCI TECH, V3, P134 NAIR PK, 1991, SEMICOND SCI TECH, V6, P393 NAIR PK, 1992, SEMICOND SCI TECH, V7, P239 RHINES FN, 1956, PHASE DIAGRAMS METAL, CH4 SILVERMAN MS, 1964, INORG CHEM, V3, P1041 NR 10 TC 8 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0022-3697 J9 J PHYS CHEM SOLIDS JI J. Phys. Chem. Solids PD DEC PY 1996 VL 57 IS 12 BP 1937 EP 1945 PG 9 SC Chemistry, Multidisciplinary; Physics, Condensed Matter GA VY575 UT ISI:A1996VY57500022 ER PT J AU Rincon, ME Suarez, R Nair, PK TI Kinetics of electrical conductivity enhancement in bismuth sulphide thin films .2. Optoelectronic properties (film) and phase transformations (powder) under oxygen annealing SO JOURNAL OF PHYSICS AND CHEMISTRY OF SOLIDS LA English DT Article DE chalcogenides; semiconductors; thin films; electrical conductivity ID NONISOTHERMAL REACTION-KINETICS AB The optoelectronic properties of oxygen annealed bismuth sulphide thin films have been determined and correlated to the physico-chemical transformations of the powder studied by Differential Scanning Calorimetry (DSC). A maximum in photoconductivity of 0.54 Ohm(-1) cm(-1) was obtained at 170 degrees C with short annealing times. The temperature dependence of the saturation rate indicates the adsorption of oxygen up to 230 degrees C. At higher temperatures oxygen gets chemisorbed and strongly diminishes the overall mobility of the film. The physico-chemical transformations observed by DSC on bismuth sulphide powder show two first order irreversible transitions in the temperature range of 200-300 degrees C. The first has been identified with crystallization of bismuthinite (Bi2S3) and BiS2. The second transition is quite broad and uncovers the decomposition of BiS2 into Bi and S and the incipient formation of bismuth oxides and sulphates. At these temperatures, the conversion of bismuth crystals into sulphates and oxides leaves bismuthinite as the only conductive medium, explaining the decrease on conductivity at higher temperatures and duration of annealing. Oxidation of bismuthinite takes place in two stages between 400-500 degrees C, a high activation energy followed by a non-activated and fast oxidation process. RP Rincon, ME, UNIV NACL AUTONOMA MEXICO,INST INVEST MAT,PHOTOVOLTA SYST GRP,LAB ENERGIA SOLAR,TEMIXCO 62580,MORELOS,MEXICO. CR AGRAWAL RK, 1992, THERMOCHIM ACTA, V203, P111 AGRAWAL RK, 1992, THERMOCHIM ACTA, V203, P93 ANDERSON H, 1992, THERMOCHIM ACTA, V203, P515 BORCHARDT HJ, 1957, J PHYS CHEM-US, V61, P917 BOTTO IL, 1995, THERMOCHIM ACTA, V249, P325 BOTTO JL, 1988, THERMOCHIM ACTA, V128, P311 CHAN DSH, 1976, THIN SOLID FILMS, V38, P163 FLYNN JH, 1991, J THERM ANAL, V37, P293 NAIR PK, SEMICOND SCI TECH, V3, P131 NAIR PK, 1991, SEMICOND SCI TECH, V6, P393 ORTON JW, 1982, J APPL PHYS, V53, P1602 RINCON ME, IN PRESS RINCON ME, 1996, J PHYS CHEM SOLIDS, V57, P1937 ROMERO A, 1992, THERMOCHIM ACTA, V203, P67 SILVERMAN MS, 1964, INORG CHEM, V3, P1041 TODOR DN, 1976, THERMAL ANAL MINERAL TRAKOVA K, 1988, J THERM ANAL, V34, P1031 NR 17 TC 12 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0022-3697 J9 J PHYS CHEM SOLIDS JI J. Phys. Chem. Solids PD DEC PY 1996 VL 57 IS 12 BP 1947 EP 1955 PG 9 SC Chemistry, Multidisciplinary; Physics, Condensed Matter GA VY575 UT ISI:A1996VY57500023 ER PT J AU SaintMartin, H RuizVicent, LE RamirezSolis, A OrtegaBlake, I TI Toward an understanding of the hydrolysis of Mg-PPi. An ab initio study of the isomerization reactions of neutral and anionic Mg-pyrophosphate complexes SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Article ID YEAST INORGANIC PYROPHOSPHATASE; METAL-ION; ENERGY; WATER; PHOSPHATES; MECHANISM; CATIONS; PH AB Ab initio calculations were performed to study the stability of various pyrophosphate species in the gas phase: H4P2O7, H3P2O7-, H2P2O72-, HP2O73-, P2O74-, and their complexes with Mg2+. It is found that the metal cation allows the existence of highly charged anions in the gas phase. We also study the isomerization reactions Mg . H2P2O7 --> (H2PO4 . Mg . PO3), (Mg . HP2O7)(-) --> (HPO4 . Mg . PO3)(-), and (Mg . P2O7)(2-) --> (PO4 . Mg . PO3)(2-), at the self-consistent-field (SCF) and second-order perturbation (MP2) levels of the theory, using a 6-31+G** basis set with diffuse and polarization functions. Other basis sets, including one of valence triple zeta plus polarization (vTZP) quality, were employed to check for the convergence of the results. It is found that the same mechanism occurs for the isomerizations of the three species: one of the P-O bridging bonds of the reactant is longer than the other, and the route to the products proceeds through its elongation. This asymmetry is induced by the metal cation in the case of the evenly charged anions. In all cases the metal cation coordinates the transition states and the leaving groups. The structures found for the complexes (H2PO4 . Mg . PO3), HPO4 . Mg . PO3)(-), and (PO4 . Mg . PO3)(2-) are different from those reported previously, the metal cation being enclosed by the two phosphates. The activation barrier increases with the charge of the anion, from Delta G degrees(double dagger)=5.6 kcal/mol for the neutral complex Mg . H2P2O7, to Delta G degrees(double dagger)=10.4 kcal/mol for the monoanion (Mg . HP2O7)(-), to Delta G degrees(double dagger)=13.5 kcal/mol for the dianion (Mg . P2O7)(2-). The positive value found for the energy of the isomerization (Mg . P2O7)(2-) --> (PO4 . Mg . PO3)(2-), Delta G degrees(double dagger)=1.8 kcal/mol, predicts the synthesis to be spontaneous in the gas phase, opposite of what occurs in the aqueous solution. This result supports the view that the hydration energy makes a large contribution to the energy of hydrolysis. The gas-phase hydrolysis reaction H2O + Mg2+ + H2P2O72- --> Mg2+ + H2PO4- + H2PO4- is also studied as a multistep reaction, involving the isomerization of H2O + (Mg . H2P2O7) --> H2O + (PO3 . Mg . H2PO4) as an intermediate step. It is found that the equilibrium in the gas phase yields H2PO4 . Mg . H2PO4 as the final species; an energy input is required for separating the metal cation from the phosphate anions. C1 UNIV AUTONOMA ESTADO MORELOS,FAC CIENCIAS,CUERNAVACA 62270,MORELOS,MEXICO. RP SaintMartin, H, UNIV NACL AUTONOMA MEXICO,INST FIS,LAB CUERNAVACA,APARTADO POSTAL 48-3,CUERNAVACA 62251,MORELOS,MEXICO. CR BERNALURUCHURTU MI, COMMUNICATION BOYD DB, 1969, J THEOR BIOL, V25, P403 CELIS H, 1987, J BIOENERG BIOMEMBR, V19, P255 COLVIN ME, 1995, J AM CHEM SOC, V117, P4537 DEMEIS L, 1984, J BIOL CHEM, V259, P6090 DEMEIS L, 1985, EUR J BIOCHEM, V152, P221 DEMEIS L, 1989, BIOCHIM BIOPHYS ACTA, V973, P333 DEWAR MJS, 1985, P NATL ACAD SCI USA, V82, P2225 DUPUIS M, 1995, HONDO 8 5 EWIG CS, 1988, J AM CHEM SOC, V110, P79 FRISCH MJ, 1993, GAUSSIAN 92 DFT GEORGE P, 1970, BIOCHIM BIOPHYS ACTA, V223, P1 GEUE RJ, 1993, AUST J CHEM, V46, P1021 HAROMY TP, 1982, BIOCHEMISTRY-US, V21, P6950 HAYES DM, 1978, J AM CHEM SOC, V100, P4331 HILL TL, 1951, J AM CHEM SOC, V73, P1656 KALCKAR HM, 1941, CHEM REV, V28, P71 KNIGHT WB, 1981, BIOCHEMISTRY-US, V20, P4079 MA BY, 1994, J PHYS CHEM-US, V98, P8216 MA BY, 1995, J PHYS CHEM-US, V99, P3815 OKEEFFE M, 1985, J PHYS CHEM-US, V89, P2304 PULLMAN A, 1963, QUANTUM BIOCH, P63 ROMERO PJ, 1989, J BIOL CHEM, V264, P7869 SAINTMARTIN H, 1991, BIOCHIM BIOPHYS ACTA, V1080, P205 SAINTMARTIN H, 1994, BIOCHIM BIOPHYS ACTA, V1207, P12 SHORTER AL, 1987, BIOCHEMISTRY-US, V26, P2060 STRYER L, 1991, BIOCHEMISTRY-US, P328 TING SJ, 1984, FEBS LETT, V165, P251 WARSHEL A, 1989, P NATL ACAD SCI USA, V86, P5820 WOLFENDEN R, 1985, J AM CHEM SOC, V107, P4345 NR 30 TC 21 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0002-7863 J9 J AMER CHEM SOC JI J. Am. Chem. Soc. PD DEC 4 PY 1996 VL 118 IS 48 BP 12167 EP 12173 PG 7 SC Chemistry, Multidisciplinary GA VX055 UT ISI:A1996VX05500021 ER PT J AU CaminoLavin, M JimenezPerez, A CastrejonGomez, V CastrejonAyala, F FigueroaBrito, R TI Function of a new trap for root-destroying Melolonthid beetles SO SOUTHWESTERN ENTOMOLOGIST LA Spanish DT Article AB A new trap for melolonthid scarabs, named CSAT-m, is described and studied in order to understand how it works. Eight chemicals from pineapple were evaluated as attractants with this trap, while ripe pineapple was used as control. Temperature of air inside and outside the CSAT-m trap was recorded during the study. The occurrence of a full solar eclipse in the area provided an opportunity to study these temperature differentials, observing a 5 degrees C difference in a short time between inside and outside the trap. Methyl acetate and ethyl acetate were the most volatile of the tested compounds; their use resulted in the most insects captured, specially the melonthids Cotinis mutabilis, Cyclocephalla guttata and Phyllophaga spp. These beetles are important pests because the adults feed on economic fruit and their larvae damage the roots of crops. Highest numbers of insects were attracted and captured when these chemicals were used during sunny days, when more chemicals were dispersed. Trap efficiency should be considered in terms of level of lure dispersion, not just in terms of time of operation. RP CaminoLavin, M, IPN,CTR DESARROLLO PROD BIOT,KM 8-5 CARR YAUTEPEC JOJUTLA,APARTADO POSTAL 24,YAUTEPEC,MORELOS,MEXICO. CR CAMINOLAVIN M, 1975, FOLIA ENTOMOL MEX, V33, P63 CAMINOLAVIN M, 1992, REV LATINOAMER QUIM, V22, P11 CUPPERUS GW, 1990, J KANSAS ENTOMOL SOC, V63, P486 MORRON MA, 1988, ENTOMOLOGIA PRACTICA WU P, 1991, J AGR FOOD CHEM, V39, P170 NR 5 TC 1 PU SOUTHWESTERN ENTOMOLOGICAL SOC PI DALLAS PA 17360 COIT RD, DALLAS, TX 75252-6599 SN 0147-1724 J9 SOUTHWEST ENTOMOLOGIST JI Southw. Entomol. PD SEP PY 1996 VL 21 IS 3 BP 325 EP 330 PG 6 SC Entomology GA VR733 UT ISI:A1996VR73300012 ER PT J AU Huang, L Zingaro, RA Meyers, EA Nair, PK Nair, MTS TI Chemical deposition of thin films of copper sulfide on glass surfaces modified with organosilanes SO PHOSPHORUS SULFUR AND SILICON AND THE RELATED ELEMENTS LA English DT Article DE organosilanes; copper sulfide films; X-ray photoelectron spectra; X-ray diffraction pattern; thermal stability ID SOLAR CONTROL; BATH DEPOSITION; CUXS AB CuS thin films were deposited on glass surfaces modified by treatment with 3-mercaptopropyltrimethoxysilane from a chemical bath made up of copper ions, sodium citrate and thioacetamide. The present method combines the advantage of using a non-ammoniacal aqueous bath for the deposition of these films with that of a surface treatment which inhibits the detachment of the film from the glass substrate when films grow thicker. Single depositions for durations of about 2-8 h at 25 degrees C yield films of thicknesses in the range of 0.13-0.25 mu m. Multiple depositions for a total period of 20 h result in a film thickness of 1 mu m. X-ray photoelectron spectra of the films indicate the molar composition of CuS and X-ray diffraction pattern confirms the covellite structure for the thin films. Results regarding the thermal stability, optical transmittance spectra and electrical properties of the films are presented. C1 UNIV NACL AUTONOMA MEXICO,LAB ENERGIA SOLAR,IIM,PHOTOVOLTA SYST GRP,TEMIXCO 65580,MORELOS,MEXICO. RP Huang, L, TEXAS A&M UNIV,DEPT CHEM,COLLEGE STN,TX 77843. CR ANDERSON R, 1991, HULSE SILICON COMPOU, P67 ASHWORTH MRF, 1976, DETERMINATION SULPHU, P8 AYWARD GH, 1974, SI CHEM DATA, P112 BHATTACHARYA RN, 1981, B MATER SCI, V3, P403 ESTRADAGASCA CA, 1992, RENEWABLE ENERGY, V2, P477 GARCIA VM, 1991, SOL ENERG MATER, V23, P47 HUANG L, IN PRESS PHOSPHORUS HUANG L, UNPUB THIN SOLID FIL HUANG L, 1994, J ELECTROCHEM SOC, V141, P2536 LADE DR, 1990, CRC HDB CHEM PHYSICS, P8 LOFERSKI JJ, 1979, SOLAR ENERGY MATER, V1, P157 NAIR MTS, 1989, SEMICOND SCI TECH, V4, P191 NAIR PK, 1989, J PHYS D APPL PHYS, V22, P829 NAIR PK, 1991, J PHYS D APPL PHYS, V24, P441 RANDHAWA HS, 1982, SOL ENERG MATER, V6, P445 RIGA J, 1983, J CHEM SOC PERK T 2, P1545 STILL ER, 1980, INORG CHIM ACTA, V46, P147 VARKEY AJ, 1989, SOL ENERG MATER, V19, P415 WAGNER CD, 1978, HDB XRAY PHOTOELECTR, P182 WINDHOLZ M, 1983, MERK INDEX, P330 NR 20 TC 6 PU GORDON BREACH SCI PUBL LTD PI READING PA C/O STBS LTD PO BOX 90, READING, BERKS, ENGLAND RG1 8JL SN 0308-664X J9 PHOSPHOR SULFUR SILICON JI Phosphorus Sulfur Silicon Relat. Elem. PY 1995 VL 105 IS 1-4 BP 175 EP 185 PG 11 SC Chemistry, Inorganic & Nuclear GA VQ051 UT ISI:A1995VQ05100023 ER PT J AU JimenezGonzalez, A SuarezParra, R TI Effect of heat treatment on the properties of ZnO thin films prepared by successive ion layer adsorption and reaction (SILAR) SO JOURNAL OF CRYSTAL GROWTH LA English DT Article ID CHEMICAL-DEPOSITION AB ZnO thin films prepared by the chemical deposition technique, SILAR (successive ion layer adsorption and reaction) exhibit zincite (hexagonal) structure, are transparent in the visible and infrared region (similar to 90% optical transmittance), and photoconductive. Heat treatments significantly modify the stoichiometry and crystal structure of as-prepared ZnO and therefore its optical and electrical properties. The dark conductivity of ZnO thin films changes according to the gas atmosphere employed during the treatment. As-prepared samples (of thickness 667 Angstrom) show a dark conductivity of 1.50 x 10(-6) [Omega . cm](-1), while a maximum dark conductivity of 2.70 x 10(-2) [Omega . cm](-1) was achieved after consecutive heat treatments in O-2 and H-2 at 350 degrees C. The optical bandgap, 3.38 eV, of the as-prepared ZnO decreases by 0.125 eV after annealing. The activation energy for the dark conductivity is much less, 0.65 eV (as prepared) to 0.11 eV (annealed in O-2) indicating that the defect structure in the film plays an important part in the charge carrier transport. RP JimenezGonzalez, A, UNIV NACL AUTONOMA MEXICO,IIM,LAB ENERGIA SOLAR,PHOTOVOLTA SYST GRP,APARTADO POSTAL 34,TEMIXCO 62580,MORELOS,MEXICO. CR BURSTEIN E, 1954, PHYS REV, V93, P632 CHOPRA KL, 1983, THIN FILM SOLAR CELL, P329 CHOPRA KL, 1983, THIN SOLID FILMS, V102, P1 GOEPEL W, 1980, PHYS REV B, V22, P6447 JIMENEZGONZAILE.AE, 1995, SEMICOND SCI TECH, V10, P1277 JIMENEZGONZALEZ A, 1991, SURF SCI, V250, P59 KLEBER W, 1983, EINFEUHRUNG KRISTALL, P299 KOFSTADT P, 1983, NONSTOICHIMETRY DIFF, P7 KOHL D, 1977, SURF SCI, V63, P96 KROEGER FH, 1956, SOLID STATE PHYS, V3, P397 MADELUNG O, 1978, SOLID STATE SCI, V2, P401 MAJOR S, 1986, J MATER RES, V1, P300 MINAMI T, 1984, JPN J APPL PHYS PT 2, V23, L280 ORTON JW, 1980, REP PROG PHYS, V43, P1263 PETROU P, 1979, APPL PHYS LETT, V35, P930 RISTOV M, 1985, THIN SOLID FILMS, V123, P63 ROTH AP, 1982, PHYS REV B, V25, P7836 SHI I, 1985, J APPL PHYS, V58, P2400 SOULETIE P, 1988, J CRYST GROWTH, V86, P248 SZE SM, 1981, PHYSICS SEMICONDUCTO, P849 TOMAR MS, 1982, THIN SOLID FILMS, V90, P419 VASANELLI L, 1987, SOL ENERG MATER, V16, P91 WEST JM, 1986, BASIC CORROSION OXID, P212 NR 23 TC 21 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-0248 J9 J CRYST GROWTH JI J. Cryst. Growth PD OCT PY 1996 VL 167 IS 3-4 BP 649 EP 655 PG 7 SC Crystallography GA VN986 UT ISI:A1996VN98600036 ER PT J AU Garcia, VM George, PJ Nair, MTS Nair, PK TI CdSe:In-In2O3 coating with n-type conductivity produced by air annealing of CdSe-In thin films SO JOURNAL OF THE ELECTROCHEMICAL SOCIETY LA English DT Article ID CADMIUM SELENIDE; DEPOSITION AB Conversion of chemically deposited intrinsic CdSe thin films to n-type coatings by a postdeposition process is described. A Cd:Se-In thin film consisting of a CdSe thin film similar to 0.15 mu m thick and a thermally evaporated indium film similar to 0.02 mu m thick was air annealed at 325 degrees C for 1 h. The resulting thin film coating of CdSe:In (0.15 mu m)-In2O3 (0.03 mu m) exhibits a sheet resistance of 790 Omega/square and an n-type conductivity of similar to 400 Omega(-1) cm for the In2O3 top layer. Etching of the film with 1 M HCl for 6 h removes the superficial In2O3 from the coating, and the underlying CdSe with indium doping shows a sheet resistance of 15 k Omega/square which corresponds to electrical. conductivity (n-type) of similar to 0.4 Omega(-1) cm(-1). The composition of the film and its variation along the depth are established through analyses of x-ray diffraction pattern and xray fluorescence spectra as well as the photocurrent response of the annealed films recorded before and after chemical etching. C1 UNIV NACL AUTONOMA MEXICO,IIM,LAB ENERGIA SOLAR,PHOTOVOLTAIC SYST GRP,TEMIXCO 62580,MORELOS,MEXICO. CR BOUDREAU RA, 1983, J ELECTROCHEM SOC, V130, P513 BOUDREAU SM, 1983, J CHEM EDUC, V60, P498 CHOPRA KL, 1982, PHYS THIN FILMS, V12, P201 FRANK G, 1981, THIN SOLID FILMS, V77, P107 GEORGE PJ, 1995, APPL PHYS LETT, V66, P3624 GORER S, 1994, J PHYS CHEM-US, V98, P5338 HODES G, 1987, PHYS REV B, V36, P4215 KAINTHLA RC, 1980, J ELECTROCHEM SOC, V127, P277 NAIR MTS, 1993, J APPL PHYS, V74, P1879 NAIR MTS, 1993, J ELECTROCHEM SOC, V140, P2987 ORTON JW, 1982, J APPL PHYS, V53, P1602 SVECHNIKOV SV, 1980, THIN SOLID FILMS, V66, P41 WILSON AJP, 1963, MATH THEORY XRAY POW, P92 ZINGARO RA, 1953, J ORG CHEM, V18, P292 NR 14 TC 13 PU ELECTROCHEMICAL SOC INC PI PENNINGTON PA 10 SOUTH MAIN STREET, PENNINGTON, NJ 08534 SN 0013-4651 J9 J ELECTROCHEM SOC JI J. Electrochem. Soc. PD SEP PY 1996 VL 143 IS 9 BP 2892 EP 2895 PG 4 SC Electrochemistry; Materials Science, Coatings & Films GA VH209 UT ISI:A1996VH20900046 ER PT J AU Cisneros, C Martinez, H Fuentes, BE Alvarez, I deUrquijo, J Dominguez, I TI Single electron capture of H+ in Mg in the energy range 0.5 to 5.0 keV SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS LA English DT Article ID COLLISIONS AB Absolute differential and total cross sections have been measured for the single electron capture of H+ in Mg at impact energies between 0.5 to 5.0 keV and over the laboratory angular range -2 degrees to 2 degrees. The total cross sections exhibit two maxima within the experimental energy range studied. The present values are compared with those from previous measurements and calculations, with which good agreement has been found. C1 UNIV NACL AUTONOMA MEXICO,INST FIS,LAB CUERNAVACA,CUERNAVACA 62191,MORELOS,MEXICO. NATL AUTONOMOUS UNIV MEXICO,FAC CIENCIAS,MEXICO CITY 04510,DF,MEXICO. CR BERKNER KH, 1969, PHYS REV, V178, P248 CHEN Z, 1994, PHYS LETT A, V194, P201 CISNEROS C, 1991, NUCL INSTRUM METH 1, V56, P285 DUBOIS RD, 1986, PHYS REV A, V34, P2738 GARCIAMADRONAL JC, 1991, 17 ICPEAC BRISB, P403 HULTGREN R, 1973, SELECTED VALUES THER MARTINEZ H, 1995, CHEM PHYS, V190, P139 MORGAN TJ, 1979, PHYS REV A, V19, P1448 OLSON RE, 1979, PHYS REV A, V20, P1366 SMITH FT, 1966, PHYS REV, V150, P79 SMITH FT, 1967, PHYS REV, V161, P131 NR 11 TC 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-583X J9 NUCL INSTRUM METH PHYS RES B JI Nucl. Instrum. Methods Phys. Res. Sect. B-Beam Interact. Mater. Atoms PD AUG PY 1996 VL 117 IS 1-2 BP 1 EP 4 PG 4 SC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Atomic, Molecular & Chemical; Physics, Nuclear GA VC427 UT ISI:A1996VC42700001 ER PT J AU Barragan, RM Heard, CL Arellano, VM Best, R Holland, FA TI Experimental performance of the water/calcium chloride system in a heat transformer SO INTERNATIONAL JOURNAL OF ENERGY RESEARCH LA English DT Article DE heat transformer; absorption systems; heat recovery ID ABSORPTION AB Absorption heat transformers are devices with the unique capability of raising the temperature of part of a low grade heat source whilst simultaneously delivering the rest of the heat at a lower temperature. The gross temperature lift attainable in the process depends on the characteristics of the working pair. Many combinations of working fluid/absorbent have been proposed although until now the water/lithium bromide system is the most widely used. Experimental results for the water/calcium chloride working pair in an absorption heat transformer are discussed. The highest gross temperature lift was found to be 19 degrees C for an absorber temperature of 84 degrees C. The highest value for the coefficient of performance was found to be 0.45, this means that 45% of the waste heat could be recovered at a higher temperature. RP Barragan, RM, INST INVEST ELECT,DEPT GEOTERMIA,POB 475,MORELOS 62000,MEXICO. CR ALEFELD G, 1991, P 18 INT C REFR MONT BARRAGAN RM, 1991, P 31 CONV AN IMIQ TA, V1, P143 BARRAGAN RM, 1994, IN PRESS INT J ENERG BERNTSSON T, 1991, P IND WORKSH IND EN BEST R, 1990, THESIS U SALFORD UK GEORGE JM, 1993, INT J REFRIG, V16, P107 HEROLD KE, 1991, INT J REFRIG, V14, P156 IYOKI S, 1989, INT J REFRIG, V13, P191 JANSEN PF, 1987, P 3 INT S LARG SCAL, P45 MASHIMO K, 1987, P IEA HEAT PUMP C CH, P271 PEREIRA SI, 1989, HEAT RECOVERY SYSTEM, V9, P521 RIVERA W, 1994, HEAT RECOV SYST CHP, V14, P173 RIVERA W, 1994, HEAT RECOV SYST CHP, V14, P185 SIDDIGMOHAMMED BE, 1983, CHEM ENG RES DES, V61, P283 SMITH IE, 1990, MANUAL SOBRE TECHNOL, P27 SMITH IE, 1992, P IEE C ADV EN CONC, P232 NR 16 TC 9 PU JOHN WILEY & SONS LTD PI W SUSSEX PA BAFFINS LANE CHICHESTER, W SUSSEX, ENGLAND PO19 1UD SN 0363-907X J9 INT J ENERG RES JI Int. J. Energy Res. PD AUG PY 1996 VL 20 IS 8 BP 651 EP 661 PG 11 SC Energy & Fuels; Nuclear Science & Technology GA VB651 UT ISI:A1996VB65100001 ER PT J AU Reyes, R SanchezVazquez, ML MerchantLarios, H Rosado, A Delgado, NM TI Effect of heparin-reduced glutathione on hamster sperm DNA unpacking and nuclear swelling SO ARCHIVES OF ANDROLOGY LA English DT Article DE acridine orange; chromatin; heparin; histone; nuclear matrix; protamine; reduced glutathione ID XENOPUS EGG EXTRACTS; AMINO-ACID SEQUENCE; MAMMALIAN SPERMATOZOA; GLYCOSAMINEGLYCAN-SULFATE; CHROMATIN STRUCTURE; RAT SPERMATOZOA; GUINEA-PIG; DECONDENSATION; PROTEIN; INVITRO AB This study examined the kinetics of sperm nuclear decondensation induced by the action of physiological concentrations of heparin and glutathione in hamster sperm nuclei as a chromatin model that contains protamine P1 and P2. Sperm suspension was incubated at different temperatures (37, 40, 43, and 46 degrees C) in media, keeping constant the concentration of either heparin or GSH and increasing concentrations of the other reagent. Spermatozoa nuclei without any treatment, incubated for 72 h, appear densely condensed. Swelling of hamster spermatozoa nuclei was observed after 30 min of incubation in the presence of efficient concentrations of heparin-GSH. The extent of this time lag was significantly reduced at higher temperatures. DNA presence was verified by the use of ethidium bromide, acridine orange, and Feulgen stain. Phase-contrast microscopy shows that nuclear decondensation begins at the equatorial levels, with DNA highly condensed at the acrosome pole, and the basal pole as the DNA attachment point. Electron microscopy observations showed that hamster sperm nuclei initiates its decompaction at the peripheral regions and this behavior remains until late stages of decondensation; nevertheless, the chromatin is organized into ''hub-like'' nuclear bodies that measured 10-100 nm in diameter, joined by a network of chromatin fibers with apparent reduction in number. At the decondensation full stage, the network seems to be wide open with a reduced number of hub-like nuclear bodies present in the interlace. DNA is not organized into topologically constrained loop domains and is attached to the basal plate instead of to the nuclear matrix or any other structure. C1 UNAM,INST INVEST BIOMED,DEPT BIOL DESARROLLO,MEXICO CITY,DF,MEXICO. UAM,DEPT REPROD BIOL,DIV CIENCIAS BIOL & SALUD,MEXICO CITY,DF,MEXICO. RP Reyes, R, IMSS,CTR INVEST BIOMED SUR,ARGENTINA 1,APDO POSTAL 25,XOCHITEPEC 62790,MORELOS,MEXICO. CR ARKHIS A, 1991, EUR J BIOCHEM, V200, P387 BALHORN R, 1982, J CELL BIOL, V93, P298 BALHORN R, 1991, BIOCHEMISTRY-US, V30, P175 BELLVE AR, 1978, J CELL BIOL, V79, A177 BIANCHI F, 1994, BIOCHEM BIOPH RES CO, V201, P1197 CALVIN HI, 1976, BIOCHIM BIOPHYS ACTA, V434, P377 CARRANCO A, 1983, ARCH ANDROLOGY, V10, P213 COELINGH JP, 1972, BIOCHIM BIOPHYS ACTA, V285, P1 CORZETT M, 1987, J CELL BIOL, V105, P105 DELGADO NM, 1980, ARCH ANDROLOGY, V4, P305 DELGADO NM, 1982, J EXP ZOOL, V224, P457 DIMITROV S, 1994, J CELL BIOL, V126, P591 EVENSON DP, 1978, J ULTRASTRUCT RES, V63, P178 FARRINGTON JE, 1991, ANN NY ACAD SCI, V637, P164 FORNES MW, 1994, ANDROLOGIA, V26, P87 GATEWOOD JM, 1987, SCIENCE, V236, P962 GRIVEAU JF, 1992, ARCH ANDROLOGY, V29, P127 HERNANDEZ O, 1977, BIOCHIM BIOPHYS ACTA, V521, P557 HUANG TTF, 1984, BIOL REPROD, V31, P797 JAGER S, 1990, J EXP ZOOL, V256, P315 KEYHANI E, 1973, BIOCHIM BIOPHYS ACTA, V305, P557 KOEHLER JK, 1983, GAMETE RES, V8, P357 KOLLER CA, 1993, NUCLEIC ACIDS RES, V21, P2952 KORNBERG RD, 1974, SCIENCE, V184, P866 LASKEY RA, 1978, NATURE, V275, P416 LEE CN, 1986, J ANIM SCI, V63, P861 LOIR M, 1975, EXP CELL RES, V92, P509 LUFT JH, 1961, J BIOPHYS BIOCH CYTO, V9, P409 MAHI CA, 1975, J REPROD FERTIL, V44, P293 MARUSHIGE Y, 1975, BIOCHIM BIOPHYS ACTA, V403, P180 MCKAY DJ, 1985, BIOSCIENCE REP, V5, P383 PERREAULT SD, 1987, BIOL REPROD, V36, P239 PHILPOTT A, 1992, CELL, V69, P759 POGANY GC, 1981, EXP CELL RES, V136, P127 REYES A, 1976, FERTIL STERIL, V27, P1452 REYES R, 1984, ARCH ANDROLOGY, V12, P203 REYES R, 1989, GAMETE RES, V23, P30 REYES R, 1991, ARCH ANDROLOGY, V26, P53 REYNOLDS ES, 1963, J CELL BIOL, V17, P208 RISLEY MS, 1986, CHROMOSOMA, V94, P217 SANCHEZVAZQUEZ ML, 1996, ARCH ANDROLOGY, V36, P161 SELIGMAN J, 1991, MOL REPROD DEV, V29, P276 SWAN MA, 1993, BIOL REPROD, V48, P987 TEJADA RI, 1984, FERTIL STERIL, V42, P87 VOGELSTEIN B, 1980, CELL, V22, P79 WARD WS, 1991, BIOL REPROD, V44, P569 WARD WS, 1993, BIOL REPROD, V48, P1193 YANAGIDA K, 1991, BIOL REPROD, V44, P440 ZETTERQVIST H, 1956, THESIS KAROLINSKA I ZIRKIN BR, 1985, GAMETE RES, V11, P349 NR 50 TC 6 PU HEMISPHERE PUBL CORP PI BRISTOL PA 1900 FROST ROAD, SUITE 101, BRISTOL, PA 19007-1598 SN 0148-5016 J9 ARCH ANDROLOGY JI Arch. Androl. PD JUL-AUG PY 1996 VL 37 IS 1 BP 33 EP 45 PG 13 SC Andrology GA UY293 UT ISI:A1996UY29300007 ER PT J AU Suarez, R Nair, PK TI Co-deposition of PbS-CuS thin films by chemical bath technique SO JOURNAL OF SOLID STATE CHEMISTRY LA English DT Article ID SOLAR CONTROL COATINGS; CUXS; OPTIMIZATION AB Chemical bath deposition of thin film PbS-CuS from solution containing Pb2+ and Cu2+ and thiourea is presented. X-ray fluorescence analyses show the relative abundance of Pb, Cu, and S in the films as a function of the duration of deposition. These results along with those obtained from X-ray diffraction analyses support the formation of thin film of the type (PbS)(1-x)(CuS)(x). An important feature of these films is their good adhesion to glass substrate even at long durations of deposition (24 h); a characteristic basic to chemically deposited PbS thin films. The near infrared optical transmittance (70%) as well as the p-type sheet resistance (1 M Omega) of the as prepared films drop considerably to typically 15% and 300 Omega when annealed at 200 degrees C in air or nitrogen ambient, both being basic behaviors of chemically deposited CuS thin films. (C) 1996 Academic Press, Inc. C1 UNIV NACL AUTONOMA MEXICO,IIM,LAB ENERGIA SOLAR,PHOTOVOLTAC SYST GRP,TEMIXCO 62580,MORELOS,MEXICO. CR AYLWARD GH, 1974, SI CHEM DATA, P34 CHOPRA KL, 1982, PHYS THIN FILMS, V12, P201 ESTRADAGASCA CA, 1993, J PHYS D APPL PHYS, V26, P1304 GARCIA VM, 1991, SOL ENERG MATER, V23, P47 HUANG L, 1994, J ELECTROCHEM SOC, V141, P2536 LOFERSKI JJ, 1979, SOLAR ENERGY MATER, V1, P157 NAIR MTS, 1989, SEMICOND SCI TECH, V4, P191 NAIR MTS, 1993, J ELECTROCHEM SOC, V140, P2987 NAIR PK, 1989, SEMICOND SCI TECH, V4, P807 NAIR PK, 1990, J PHYS D APPL PHYS, V23, P150 NAIR PK, 1991, J PHYS D APPL PHYS, V24, P441 OKAMOTO K, 1973, JPN J APPL PHYS, V12, P1130 PARHI N, 1995, THIN SOLID FILMS, V254, P47 REDDY GB, 1987, SOL ENERG MATER, V15, P383 SHARMA NC, 1976, MAT RES B, V11, P1109 NR 15 TC 7 PU ACADEMIC PRESS INC JNL-COMP SUBSCRIPTIONS PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 SN 0022-4596 J9 J SOLID STATE CHEM JI J. Solid State Chem. PD MAY PY 1996 VL 123 IS 2 BP 296 EP 300 PG 5 SC Chemistry, Inorganic & Nuclear; Chemistry, Physical GA UW500 UT ISI:A1996UW50000016 ER PT J AU George, PJ SanchezJuarez, A Nair, PK TI Modification of electrical, optical and crystalline properties of chemically deposited CdS films by thermal diffusion of indium and tin SO SEMICONDUCTOR SCIENCE AND TECHNOLOGY LA English DT Article AB In a recent work we reported that chemically deposited intrinsic CdS thin films can be converted into n-type with an electrical conductivity of similar to 102 Omega(-1) cm(-1) by solid state diffusion of indium at temperatures of 300-350 degrees C from a thin film of indium deposited by thermal evaporation on the CdS surface. In the present study, we report on the enhancement of grain size accompanying this diffusion process and its correlation with a reduction in the optical bandgap. X-ray powder diffraction patterns show that the typical grain size, similar to 13 nm, of the as-deposited CdS film of 150 nm thickness increases to about 17 nm when the CdS-ln film is heat treated at 350 degrees C for 1 h. There is a corresponding decrease in the optical bandgap from 2.58 eV (as-prepared) to 2.37 eV (heat treated CdS-ln). The heat treatments of CdS only and CdS-Sn films have also led to an increase in the electrical conductivity by a factor of 10(8) and a reduction in the bandgap, but with little effect on grain size. C1 KURUKSHETRA UNIV,DEPT ELECTR SCI,KURUKSHETRA 132119,HARYANA,INDIA. RP George, PJ, UNIV NACL AUTONOMA MEXICO,IIM,LAB ENERGIA SOLAR,PHOTOVOLTAIC SYST GRP,TEMIXCO 62580,MORELOS,MEXICO. CR 1982, P 16 IEEE PHOT SPEC BASOL BM, 1993, 1991 FY NREL, P50 CHU TL, 1993, ADV SOLAR ENERGY, V8, P271 FAHRENBRUCH AL, 1983, FUNDAMENTALS SOLAR C, P357 GEORGE PJ, 1995, APPL PHYS LETT, V66, P3624 HODES G, 1987, PHYS REV B, V36, P4215 MOSKOVITS M, 1990, CHEM PHYSICS ATOMIC, P397 NAIR MTS, 1994, J APPL PHYS, V75, P1557 NAIR PK, 1987, SOL CELLS, V22, P221 NAIR PK, 1988, SEMICOND SCI TECH, V3, P134 ORTON JW, 1982, J APPL PHYS, V53, P1602 SZE SM, 1981, PHYSICS SEMICONDUCTO, P849 TUTTLE JR, 1995, P SOC PHOTO-OPT INS, V2531, P194 WILSON AJP, 1963, MATH THEORY XRAY POW, P92 NR 14 TC 5 PU IOP PUBLISHING LTD PI BRISTOL PA TECHNO HOUSE, REDCLIFFE WAY, BRISTOL, ENGLAND BS1 6NX SN 0268-1242 J9 SEMICOND SCI TECHNOL JI Semicond. Sci. Technol. PD JUL PY 1996 VL 11 IS 7 BP 1090 EP 1095 PG 6 SC Engineering, Electrical & Electronic; Materials Science, Multidisciplinary; Physics, Condensed Matter GA UW578 UT ISI:A1996UW57800021 ER PT J AU Hu, HL Nair, PK TI Electrical and optical properties of poly(methyl methacrylate) sheets coated with chemically deposited CuS thin films SO SURFACE & COATINGS TECHNOLOGY LA English DT Article DE electrical properties; optical properties; poly(methyl methacrylate); CuS thin films; chemical deposition ID SOLAR CONTROL COATINGS; COPPER SULFIDE; CUXS AB Chemical bath deposition of CuS thin films of approximate to 0.3 mu m thickness on poly(methyl methacrylate) (PMMA) sheets of 1.5 mm thickness is described. The deposition is made at 26 degrees C for duration up to 15 h or at 50 degrees C for up to 4 h. Studies on the variation of sheet resistance (R(square)) of the films as a function of duration of deposition, annealing time and annealing temperature showed a minimum R(square) value of 24 Ohm. This was obtained in PMMA sheets with CuS films deposited for 6 h at 26 degrees C and later annealed at 125 degrees C for 30 min. Optical transmittance spectra of the coated PMMA sheets in the 0.35-2.5 mu m region showed maxima (transmittance of 30-40%) for wavelengths in the 0.5-0.6 mu m region in the case of the annealed films. The results are compared with those for CuS films deposited on glass substrates. Applications of the coated PMMA sheets as solar control glazing and in metallization by electroplating are discussed. RP Hu, HL, UNIV NACL AUTONOMA MEXICO,IIM,LAB ENERGIA SOLAR,PHOTOVOLTA SYST GRP,TEMIXCO 62580,MORELOS,MEXICO. CR AYLWARD GH, 1974, SCI CHEM DATA, P112 CHARRIER JM, 1990, POLYM MAT PROCESSING CHOPRA KL, 1983, THIN FILM SOLAR CELL, P507 COUVE S, 1973, THIN SOLID FILMS, V15, P223 LOFERSKI JJ, 1979, SOLAR ENERGY MATER, V1, P157 NAIR MTS, 1989, SEMICOND SCI TECH, V4, P191 NAIR MTS, 1989, SEMICOND SCI TECH, V4, P599 NAIR MTS, 1993, J ELECTROCHEM SOC, V140, P212 NAIR PK, 1989, J PHYS D APPL PHYS, V22, P829 NAIR PK, 1991, J PHYS D APPL PHYS, V24, P441 NAIR PK, 1992, SEMICOND SCI TECH, V7, P239 NAIR PK, 1993, J ELECTROCHEM SOC, V140, P539 NAIR PK, 1993, J ELECTROCHEM SOC, V140, P754 OKAMOTO K, 1973, JPN J APPL PHYS, V12, P1130 PRITCHARD DC, 1978, LIGHTING, P8 RANDHAWA HS, 1982, SOL ENERG MATER, V6, P445 ZEBRAUSKAS A, 1990, J ADHES SCI TECHNOL, V4, P25 NR 17 TC 16 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE 1 PA PO BOX 564, 1001 LAUSANNE 1, SWITZERLAND SN 0257-8972 J9 SURF COAT TECH JI Surf. Coat. Technol. PD JUN PY 1996 VL 81 IS 2-3 BP 183 EP 189 PG 7 SC Materials Science, Coatings & Films; Physics, Applied GA UR497 UT ISI:A1996UR49700008 ER PT J AU Fernandez, AM Sebastian, PJ Bhattacharya, RN Noufi, R Contreras, M Hermanns, AM TI An 8% CuInSe2-based solar cell formed from an electrodeposited precursor film SO SEMICONDUCTOR SCIENCE AND TECHNOLOGY LA English DT Article AB An 8% CuInSe2 (CIS) based solar cell was developed using an electrodeposited CIS precursor film subjected to post-deposition heat treatment at 550 degrees C in Se and In atmospheres. The cell structure consisted of Mo/CIS/CdS/i-ZnO/ZnO/MgF2/Al-Ni. The cell parameters such as J(sc) = 32.1 mA cm(-2) V-oc = 394 mV, FF = 62.3% and eta = 7.9% were determined from I-V characterization of the annealed cell at a light intensity of 1000 W m(-2). The cell parameters improved after annealing in air at 200 degrees C. A carrier density of 6.3 x 10(17) cm(-3) was obtained from the C-V characterization of the cell. C1 NATL RENEWABLE ENERGY LAB,GOLDEN,CO 80401. UNIV COLORADO,DEPT PHYS,BOULDER,CO 80309. RP Fernandez, AM, UNAM,IIM,LAB ENERGIA SOLAR,TEMIXCO 62580,MORELOS,MEXICO. CR BHATTACHARYA RN, 1996, J ELECTROCHEM SOC, V43, P854 CONTRERAS M, 1993, APPL PHYS LETT, V63, P1824 GUPTA A, 1994, SOL ENERG MAT SOL C, V32, P137 LINCOT D, 1994, P 1 WORLD C PHOT EN, V1, P136 NEGAMI T, 1994, SOL ENERG MAT SOL C, V35, P215 ROCKETT A, 1994, THIN SOLID FILMS, V237, P1 SEBASTIAN PJ, 1995, ADV MATER OPT ELECTR, V5, P11 SEBASTIAN PJ, 1995, APPL ENERG, V52, P199 SEBASTIAN PJ, 1996, SOLAR ENERGY MAT SOL, V52, P199 YAMANAKA S, 1993, P 23 IEEE PVSC LOUIS NR 10 TC 12 PU IOP PUBLISHING LTD PI BRISTOL PA TECHNO HOUSE, REDCLIFFE WAY, BRISTOL, ENGLAND BS1 6NX SN 0268-1242 J9 SEMICOND SCI TECHNOL JI Semicond. Sci. Technol. PD JUN PY 1996 VL 11 IS 6 BP 964 EP 967 PG 4 SC Engineering, Electrical & Electronic; Materials Science, Multidisciplinary; Physics, Condensed Matter GA UQ284 UT ISI:A1996UQ28400020 ER PT J AU Oseguera, MAP Guereca, L LopezMunguia, A TI Properties of levansucrase from Bacillus circulans SO APPLIED MICROBIOLOGY AND BIOTECHNOLOGY LA English DT Article ID SUBTILIS LEVANSUCRASE; ZYMOMONAS-MOBILIS; LEVAN; DEXTRANSUCRASE; PURIFICATION; PROTEINS; BINDING AB A polysaccharide-producing bacterium was isolated from cane sugar. It was identified as Bacillus circulans and produced levansucrase at pH and temperature optima of 5-7 and 40 degrees C respectively. The enzyme is extracellular and inducible with sucrose. It possesses initial hydrolytic and transferase activities that can be altered by modifying reaction conditions. Levansucrase was recovered from the fermentation broth by extraction with polyethylene glycol (1500 Da). Further purification resulted in an enzyme with a molecular mass of 52 kDa and a pI of 4.7. At high sucrose concentration (300 mM), the transferase activity but not the hydrolase activity were inhibited. Levan increased the transferase activity but had no effect on the hydrolytic activity. The levansucrase had high transferase activity with maltose, galactose and lactose and moderate activity towards sorbitol and glycerol. C1 UNIV NACL AUTONOMA MEXICO,INST BIOTECNOL,DEPT BIOINGN,CUERNAVACA 62271,MORELOS,MEXICO. CR BRADFORD MM, 1976, ANAL BIOCHEM, V72, P248 CHAMBERT R, 1974, EUR J BIOCHEM, V41, P285 CHAMBERT R, 1976, EUR J BIOCHEM, V62, P55 CHAMBERT R, 1991, BIOCHEM J, V279, P35 CRITTENDEN RG, 1994, APPL MICROBIOL BIOT, V41, P302 DAVIS BJ, 1964, ANN NY ACAD SCI, V121, P404 GODSON GN, 1970, ANAL BIOCHEM, V35, P66 GOLDENBERG DP, 1990, PROTEIN STRUCTURE PR, P231 GROSS M, 1992, PHYSIOL MOL PLANT P, V40, P371 HAN YW, 1989, J IND MICROBIOL, V4, P447 KAWAI H, 1992, BIOSCI BIOTECH BIOCH, V56, P853 KEITH J, 1991, BIOTECHNOL BIOENG, V38, P557 KIM D, 1994, ENZYME MICROB TECH, V16, P1010 KOBAYASHI M, 1986, AGR BIOL CHEM TOKYO, V50, P2585 LAEMMLI UK, 1970, NATURE, V227, P680 LEBRUN E, 1980, J BIOL CHEM, V255, P12034 LYNESS EW, 1983, BIOTECHNOL LETT, V5, P345 OHTSUKA K, 1992, BIOSCI BIOTECH BIOCH, V56, P1373 PAUL F, 1986, CARBOHYD RES, V149, P433 PERLOT P, 1984, ANN NY ACAD SCI, V434, P468 RADOLA BJ, 1973, BIOCHIM BIOPHYS ACTA, V295, P412 RIGHETTI PG, 1976, ISOELECTRIC FOCUSING, P381 ROBYT JF, 1977, ARCH BIOCHEM BIOPHYS, V183, P726 TANAKA T, 1979, J BIOCH, V85, P287 TOMOMATSU H, 1994, FOOD TECHNOL-CHICAGO, V48, P61 TSUCHIYA HM, 1952, J BACTERIOL, V64, P521 VANBALKEN JAM, 1991, APPL MICROBIOL BIOT, V35, P216 YANASE H, 1992, BIOSCI BIOTECH BIOCH, V56, P1335 NR 28 TC 6 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 SN 0175-7598 J9 APPL MICROBIOL BIOTECHNOL JI Appl. Microbiol. Biotechnol. PD MAY PY 1996 VL 45 IS 4 BP 465 EP 471 PG 7 SC Biotechnology & Applied Microbiology GA UP628 UT ISI:A1996UP62800004 ER PT J AU Rodriguez, M Gomez, A Gonzalez, F Barzana, E LopezMunguia, A TI Selectivity of methyl-fructoside synthesis with beta-fructofuranosidase SO APPLIED BIOCHEMISTRY AND BIOTECHNOLOGY LA English DT Article DE alcoholysis; methyl-fructoside; beta-fructofuranosidase; invertase ID ORGANIC 2-PHASE SYSTEM; ENZYMATIC-SYNTHESIS; GLUCOSIDE SYNTHESIS; INVERTASE; WATER; XYLOSIDASE; SUCROSE; SOLVENTS AB Enzyme synthesis of methyl fructoside was studied using beta-fructofuranosidase from Sacharomyces cerevisiae and sucrose and methanol as substrates. Taking into account the inhibition and deactivation effects of methanol on the enzyme, a system with 4.9M (20%, v/v) methanol was selected. At this alcohol level, 35% of sucrose is converted to fructoside at low or high substrate concentrations. The effect of enzyme concentration, pH, and temperature on both the synthesis and the hydrolysis of the fructoside was investigated. It was found that if the reaction proceeds at pH 6.0, 4 degrees C and/or 0.014 mg/mL (3 U/mL) of beta-fructofuranosidase at varying sucrose concentrations, methyl fructoside may be obtained with a minimum loss of the fructoside at the end of the reaction. C1 UNAM,INST BIOTECNOL,APDO,CUERNAVACA 62271,MORELOS,MEXICO. UNAM,FAC QUIM,UNIVERSITARIA,DF,MEXICO. CR ANDERSEN B, 1969, ACTA CHEM SCAND, V23, P2367 BOWSHHI L, 1971, BIOTECHNOL BIOENG, V1, P641 COMBES D, 1983, CARBOHYD RES, V117, P215 DORDICK J, 1991, APPL BIOCATALYSIS, V1, P24 NELSON JM, 1928, J AM CHEM SOC 2, V50, P2188 SELISKO B, 1990, BIOTECHNOL BIOENG, V35, P1006 SHINOYAMA H, 1988, AGR BIOL CHEM TOKYO, V52, P2197 SHINOYAMA H, 1988, AGR BIOL CHEM TOKYO, V52, P2375 SHINOYAMA H, 1991, AGR BIOL CHEM TOKYO, V55, P1679 SHINOYAMA H, 1991, B CHEM SOC JPN, V64, P291 STEVENSON DE, 1993, BIOTECHNOL BIOENG, V42, P657 STRAATHOF AJJ, 1986, CARBOHYD RES, V146, P154 STRAATHOF AJJ, 1988, J CARBOHYD CHEM, V7, P223 SUMNER JB, 1935, J BIOL CHEM, V108, P51 ULBRICHHOFMANN R, 1993, ENZYME MICROB TECH, V15, P33 VULFSON EN, 1990, BIOTECHNOL LETT, V12, P397 VULFSON EN, 1990, ENZYME MICROB TECH, V12, P950 NR 17 TC 19 PU HUMANA PRESS INC PI TOTOWA PA 999 RIVERVIEW DRIVE SUITE 208, TOTOWA, NJ 07512 SN 0273-2289 J9 APPL BIOCHEM BIOTECH JI Appl. Biochem. Biotechnol. PD MAY PY 1996 VL 59 IS 2 BP 167 EP 175 PG 9 SC Biochemistry & Molecular Biology; Biotechnology & Applied Microbiology GA UP614 UT ISI:A1996UP61400006 ER PT J AU SanchezVazquez, ML Reyes, R Delgado, NM MerchantLarios, H Rosado, A TI Differential decondensation of class I (rat) and class II (mouse) spermatozoa nuclei by physiological concentrations of heparin and glutathione SO ARCHIVES OF ANDROLOGY LA English DT Article DE chromatin; heparin; histone; protamine; reduced glutathione ID HUMAN-SPERM NUCLEI; GLYCOSAMINEGLYCAN-SULFATE; FOLLICULAR-FLUID; INVITRO; CHROMATIN; OOCYTES; GLYCOSAMINOGLYCANS; ULTRASTRUCTURE; PURIFICATION; MATURATION AB The kinetics of sperm nuclear decondensation induced by the action of physiological concentrations of heparin and glutathione was studied by comparing two rodents: the rat, with very stable protamine P1 containing chromatin (class I nuclei), and the mouse, with protamine P1 and protamine P2 (class II nuclei). Sperm suspensions were incubated at different temperatures (37, 40; 43, and 46 degrees C) in media while keeping a constant concentration of either heparin or GSH and increasing concentrations of the other reagent. Spermatozoa nuclei without any treatment incubated for 72 h appear densely condensed. Swelling of mouse spermatozoa nuclei was observed after 30 min of incubation in the presence of efficient concentrations of heparin-GSH. The extent of this time lag was significantly reduced at higher temperatures. This behavior was also observable in the rat, but required time lags of 3-4 h. Electron microscopy observations showed that the pattern of nuclear decondensation was different in both animal species. Mice sperm nuclei initiates its decompaction by the peripheral regions and this behavior remains until late stages of decondensation. On the contrary, rat spermatozoa nuclei decondense initially at the central part of the nuclei while the periphery remains condensed, showing numerous residues of densely packed chromatin. In both cases, the chromatin is organized into ''hub-like'' nuclear bodies joined by a network of chromatin fibers. C1 IMSS,CTR INVEST BIOMED SUR,XOCHITEPEC 62790,MORELOS,MEXICO. NATL AUTONOMOUS UNIV MEXICO,INST INVEST BIOMED,DEPT BIOL DESARROLLO,MEXICO CITY 04510,DF,MEXICO. DIV CIENCIAS BIOL & SALUD,DEPT REPROD BIOL,MEXICO CITY,DF,MEXICO. CR ALLEN MJ, 1993, CHROMOSOMA, V102, P623 BELLIN ME, 1987, J DAIRY SCI, V70, P1913 CALVIN HI, 1976, BIOCHIM BIOPHYS ACTA, V434, P377 CARRANCO A, 1983, ARCH ANDROLOGY, V10, P213 DELGADO NM, 1980, ARCH ANDROLOGY, V4, P305 DELGADO NM, 1982, J EXP ZOOL, V224, P457 GALL WE, 1976, EXP CELL RES, V102, P349 GEBAUER H, 1978, BIOL REPROD, V18, P350 HERNANDEZ O, 1977, BIOCHIM BIOPHYS ACTA, V521, P557 JAGER S, 1990, J EXP ZOOL, V256, P317 KEYHANI E, 1973, BIOCHIM BIOPHYS ACTA, V305, P557 KOEHLER JK, 1983, GAMETE RES, V8, P357 KOLLER CA, 1993, NUCLEIC ACIDS RES, V21, P2952 KVIST U, 1980, INT J ANDROL, V3, P130 LUFT JH, 1961, J BIOPHYS BIOCH CYTO, V9, P409 MAHI CA, 1975, J REPROD FERTIL, V44, P293 MARUSHIGE Y, 1975, BIOCHIM BIOPHYS ACTA, V403, P180 PERREAULT SD, 1988, BIOL REPROD, V39, P157 PERREAULT SD, 1988, DEV BIOL, V125, P181 REYES R, 1984, ARCH ANDROLOGY, V12, P203 REYES R, 1989, GAMETE RES, V23, P39 REYES R, 1991, ARCH ANDROLOGY, V26, P53 REYNOLDS ES, 1963, J CELL BIOL, V17, P208 SIPSKI ML, 1977, BIOL REPROD, V16, P428 SWAN MA, 1993, BIOL REPROD, V48, P987 TADANO Y, 1978, HISTOCHEMISTRY, V57, P203 TESARIK J, 1989, GAMETE RES, V24, P135 THIBAULT C, 1973, ANN BIOLOGIE ANIMA S, V13, P145 VALENCIA A, 1984, ARCH ANDROL S, V12, P109 YANAGIMACHI R, 1981, FERTILIZATION EMBRYO, P81 YANAGIMACHI R, 1994, PHYSL REPROD, V1, A189 YOSHIDA M, 1993, MOL REPROD DEV, V35, P76 ZETTERQVIST H, 1956, THESIS KAROLINSKA I ZIRKIN BR, 1977, BIOL REPROD, V17, P131 ZIRKIN BR, 1985, GAMETE RES, V11, P349 NR 35 TC 8 PU HEMISPHERE PUBL CORP PI BRISTOL PA 1900 FROST ROAD, SUITE 101, BRISTOL, PA 19007-1598 SN 0148-5016 J9 ARCH ANDROLOGY JI Arch. Androl. PD MAY-JUN PY 1996 VL 36 IS 3 BP 161 EP 176 PG 16 SC Andrology GA UM457 UT ISI:A1996UM45700001 ER PT J AU Sanchez, J Castillo, G Medrano, AI MartinezPalomo, A Rodriguez, MH TI In vitro growth of Vibrio cholerae in cholera stool fluid leads to differential expression of virulence factors SO ARCHIVES OF MEDICAL RESEARCH LA English DT Article DE experimental cholera model; cholera toxin regulation; Vibrio mannose-sensitive hemagglutinin; cholera stool ion concentration ID HEMAGGLUTINATING ACTIVITY; TOXIN AB We report on the physiological response of Vibrio cholerae upon growth on bacteria-free intestinal fluids prepared from feces of individuals in the acute phase of cholera. Sterilized stool fluids supported growth of V. cholerae to reach 0.3 - 0.4 O.D. units (600 nm) at 37 degrees C. Scanning electron microscopy showed vibrios to be slender and elongated as compared to bacteria in synthetic media. Growth in stool fluid apparently induced expression of several immunoreactive proteins using cholera convalescent sera. Supernatants of fluid-grown vibrios had undetectable cholera toxin (CT) concentrations. Soluble hemagglutinins and soluble proteases were much less reduced when compared to cultures in Syncase or AKI media while cell-associated mannose-sensitive hemagglutinin (MSHA) was expressed at good levels. Lack of production of CT in fluid devoid of tissue may be due to absence of stimulating elements in intact intestine. Alternatively, culturing V. cholerae in stool fluid might resemble a late proliferation stage where downregulation of toxin might occur, irrespectively, concomitant production of other virulence factors represents a phenomenon of differential regulation by fluid. Efforts are now underway to determine if this response depends upon factors in stool fluid acting through known genetic regulatory cascades or other. Attempts are also geared to identify fluid-induced proteins and their genes. C1 IPN,CTR INVEST & ESTUDIOS AVANZADOS,MEXICO CITY,DF,MEXICO. RP Sanchez, J, INSP,CTR INVEST ENFERMEDADES INFECCIOSAS,AV UNIV 655,CUERNAVACA 62508,MORELOS,MEXICO. CR DIRITA VJ, 1992, MOL MICROBIOL, V6, P451 FINKELSTEIN RA, 1966, J IMMUNOL, V96, P440 HERRINGTON DA, 1988, J EXP MED, V168, P1487 IWANAGA M, 1986, MICROBIOL IMMUNOL, V30, P1075 JONES GW, 1976, INFECT IMMUN, V14, P232 JONSON G, 1994, MOL MICROBIOL, V13, P109 MILLER VL, 1984, P NATL ACAD SCI USA, V81, P3471 MILLER VL, 1987, CELL, V48, P271 MILLER VL, 1988, J BACTERIOL, V170, P2573 RABBANI GH, 1992, CHOLERA, P209 SVENNERHOLM AM, 1986, MED BIOL, V64, P23 SVENNERHOLM AM, 1986, MONOCLONAL ANTIBODIE, V3, P77 SWIFT S, 1994, TRENDS MICROBIOL, V2, P193 TEPPEMA JS, 1987, INFECT IMMUN, V55, P2093 NR 14 TC 2 PU INST MEXICANO SEGURO PI MEXICO D F PA SOCIAL APDO POSTAL 73-032, MEXICO D F 03020, MEXICO SN 0188-0128 J9 ARCH MED RES JI Arch. Med. Res. PY 1995 VL 26 SI Sp. Iss. SI BP S47 EP S53 PG 7 SC Medicine, Research & Experimental GA UM158 UT ISI:A1995UM15800011 ER PT J AU MarquezSerrano, M VazquezMartinez, D GarciaMolina, C TI Migration patterns of medical students in Mexico. SO SALUD PUBLICA DE MEXICO LA Spanish DT Article DE education, medical; development of human resources; Mexico AB Objective. This work aimed to determine the migration patterns of medical students within Mexico. Materials and methods. We obtained the places of origin of graduates and the stares where they registered their medical degrees at the Ministry of Education General Registry of Professions (SEP), between 1970-1974, 1980-1984 and 1885-1989. Data were organized as follows: Attracting foci, sending foci, transition foci, and important migrant flows. Results. The concentration of medical human resource development is reflected by the existence of a few attracting foci (D.F., Jalisco, Nuevo Leon, and to a less extent, Puebla and Michoacan). Also, we observed the persistence of traditional sending foci (Guanajuato, Chiapas, Colima, Campeche). However, some important changes occurred throughout the study period namely, a decrease of the migratory mobility of university students. During 1970-1974, almost half of them (47%) obtained their degrees outside their place of origin; during 1980-1984 this figure decreased to 34% and during 1985-1989, it decreased further to 30.6%. Second, the participation of D.F. as a main human resource development center diminished; from 59% to 40% during 1970-1974, it went down, to 30% in the following quinquennia, while it increased in Jalisco, Michoacan and Nuevo Leon. Conclusions. The establishment of medical schools in almost every Mexican state has had a central role in the migration patterns of medical students. Nevertheless, our results show that there are other reasons accounting for the persistence of the concentration of medical human resources development in main cities of the nation such as Guadalajara and Monterrey. C1 UNIV NACL AUTONOMA MEXICO,CTR REG INVEST MULTIDISCIPLINARIAS,MEXICO CITY,DF,MEXICO. RP MarquezSerrano, M, INST NACL SALUD PUBL,CISS,DEPT INVEST RECURSOS SALUD,AV UNIV 655,CUERNAVACA 62508,MORELOS,MEXICO. CR *AS NAC U I ED SUP, 1984, MATR PERS DOC CARR M, P53 COLLADOARDON R, 1976, MED ESTRUCTURA SOCIA, P124 FRENK J, 1980, GAC MED MEX, V116, P187 FRENK J, 1980, GAC MED MEX, V116, P265 FRENK J, 1985, ED MED SALUD, V19, P426 FRENK J, 1987, HLTH POLICY PLANN, P2 FRENK J, 1988, C POL DYN PHYS MANP FRENK J, 1990, SALUD PUBLICA MEXICO, V32, P440 RINCON M, 1984, ASPECTOS METODOLOG B, V1009 SANDOVALNAVARRE.J, 1986, CIENCIA DESARROLLO, V69, P43 NR 10 TC 1 PU INST NACIONAL SALUD PUBLICA PI CUERNAVACA PA AV UNIVERSIDAD 655, COL SANTA MARIA AHUACATITLAN, CUERNAVACA 62508, MORELOS, MEXICO SN 0036-3634 J9 SALUD PUBLICA MEXICO JI Salud Publica Mexico PD JAN-FEB PY 1996 VL 38 IS 1 BP 20 EP 28 PG 9 SC Public, Environmental & Occupational Health GA UG015 UT ISI:A1996UG01500005 ER PT J AU GomezDaza, O Garcia, VM Nair, MTS Nair, PK TI Highly photosensitive CdSe coatings by screen printing and sintering technique SO APPLIED PHYSICS LETTERS LA English DT Article ID PHOTOVOLTAIC PROPERTIES; SOLAR-CELLS; FILMS AB CdSe powder precipitated from a chemical bath was screen printed on glass substrates using ZnCl2 as flux, with flux to powder ratio (FPR) varying in the range of 0.1 to 0.5 by weight, and propylene glycol as binder. After a subsequent sintering in air for 1 h at 450 degrees C, the screen printed coatings showed a photocurrent to darkcurrent ratio of similar to 10(8) under tungsten halogen illumination of 2000 W m(-2). X-ray diffraction studies showed that sintering causes the conversion of the ZnCl2 flux into hexagonal phase ZnO which would hh the void among the CdSe particles. The optimum FPR and the sintering temperature to achieve maximum photosensitivity in the coatings are presented. The coatings may be used in the development of highly photosensitive light dependent resistors. (C) 1996 American Institute of Physics. RP GomezDaza, O, UNIV NACL AUTONOMA MEXICO,LAB ENERGIA SOLAR,IIM,PHOTOVOLTAIC SYST GRP,TEMIXCO 62580,MORELOS,MEXICO. CR BUBE RH, 1992, PHOTOELECTRONIC PROP, P74 CHOPRA KL, 1983, THIN FILM SOLAR CELL, P233 GARCIA FJ, 1983, JPN J APPL PHYS S1, V22, P535 HODES G, 1980, NATURE, V285, P29 IKEGAMI S, 1988, SOL CELLS, V23, P89 KAINTHLA RC, 1980, J ELECTROCHEM SOC, V127, P277 KIM HS, 1992, THIN SOLID FILMS, V214, P207 NAIR MTS, 1993, J APPL PHYS, V74, P1879 NAIR PK, 1988, SEMICOND SCI TECH, V3, P21 SEBASTIAN PJ, 1992, J PHYS D APPL PHYS, V25, P1848 STANLEY AG, 1975, APPLIED SOLID STATE, V5, P251 ZINGARO RA, 1953, J ORG CHEM, V18, P292 NR 12 TC 5 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD APR 1 PY 1996 VL 68 IS 14 BP 1987 EP 1989 PG 3 SC Physics, Applied GA UC483 UT ISI:A1996UC48300036 ER PT J AU Bhattacharya, RN Fernandez, AM Contreras, MA Keane, J Tennant, AL Ramanathan, K Tuttle, JR Noufi, RN Hermann, AM TI Electrodeposition of In-Se, Cu-Se, and Cu-In-Se thin films SO JOURNAL OF THE ELECTROCHEMICAL SOCIETY LA English DT Article ID CUINSE2 AB Indium-selenium, copper-selenium, and copper-indium-selenium thin films have been prepared by electrodeposition techniques on molybdenum substrates. Electrodeposited precursors are prepared at varying potentials, pH, and deposition times. The adhesion and uniformity of indium selenide on molybdenum substrates are improved by electrodepositing an initial copper layer (500 Angstrom) on molybdenum. The films (In-Se, Cu-Se, and Cu-In-Se) are annealed at 250 and 450 degrees C in Ar for 15 min and are slow-cooled (3 degrees C/min). The films are characterized by electron microprobe analysis, inductive-coupled plasma spectrometry, x-ray diffraction analysis, Auger electron spectroscopy, and scanning electron microscopy. The as-deposited precursor films are loaded in a physical evaporation chamber and additional In or Cu and Se are added to the film to adjust the final composition to CuInSe2. The device fabricated using electrodeposited Cu-In-Se precursor layers resulted in a solar cell efficiency of 9.4%. C1 UNIV NACL AUTONOMA MEXICO,IIM,LAB ENERGIA SOLAR,TEMIXCO 62580,MORELOS,MEXICO. UNIV COLORADO,DEPT PHYS,BOULDER,CO 80301. RP Bhattacharya, RN, NATL RENEWABLE ENERGY LAB,GOLDEN,CO 80401. CR BHATTACHARYA RN, 1983, J ELECTROCHEM SOC, V130, P2040 BHATTACHARYA RN, 1986, SOL CELLS, V16, P237 CONTRERAS M, 1993, P 23 IEEE PHOT SPEC DEVANEY WE, 1985, P 18 IEEE PHOT SPEC GUILLEMOLES JF, 1994, ADV MATER, V6, P379 GUILLEN C, 1991, SOLAR ENERGY MAT, V25, P31 HERRERO J, 1987, SOL ENERG MATER, V16, P477 HODES G, 1986, SOL CELLS, V16, P245 KAPUR VK, 1987, SOL CELLS, V21, P65 PERN FJ, 1988, SOL CELLS, V24, P81 POTTER RR, 1985, P 18 IEEE PHOT SPEC ROCKETT A, 1994, THIN SOLID FILMS, V237, P1 SCHUMANN B, 1981, SOV PHYS-CRYSTALLOGR, V26, P678 STOLT L, 1992, P 11 EC PHOT SOL EN SUDO Y, 1993, JPN J APPL PHYS PT 1, V32, P1562 THOUIN L, 1994, ADV MATER, V6, P376 THOUIN L, 1995, J ELECTROCHEM SOC, V142, P2996 TUTTLE J, 1988, SOL CELLS, V24, P67 TUTTLE JR, 1995, PROG PHOTOVOLTAICS NR 19 TC 29 PU ELECTROCHEMICAL SOC INC PI PENNINGTON PA 10 SOUTH MAIN STREET, PENNINGTON, NJ 08534 SN 0013-4651 J9 J ELECTROCHEM SOC JI J. Electrochem. Soc. PD MAR PY 1996 VL 143 IS 3 BP 854 EP 858 PG 5 SC Electrochemistry; Materials Science, Coatings & Films GA UC203 UT ISI:A1996UC20300021 ER PT J AU Garcia, VM Nair, MTS Nair, PK Zingaro, RA TI Preparation of highly photosensitive CdSe thin films by a chemical bath deposition technique SO SEMICONDUCTOR SCIENCE AND TECHNOLOGY LA English DT Article ID CADMIUM SELENIDE AB Thin films of CdSe were deposited by a chemical bath technique from citratocadmium(II) or tartratocadmium(II) complex ions and N, N-dimethylselenourea. The final thicknesses of the films were 0.17 mu m from the citrate bath and 0.28 mu m from the tartrate bath, when the depositions were made at room temperature. The films are uniform and adherent to glass substrates. The as-prepared films are only marginally photosensitive with a photocurrent to dark current ratio of < 10 under white light of intensity 2.1 kW m(-2). Annealing the films in air for 30 min-2 h at 300-450 degrees C results in high photosensitivities, 10(3)-10(7), depending on the film thickness, bath composition, and the duration and temperature of annealing. The photocurrent rise and decay time are short, typically of the order of milliseconds. The combination of film thickness, annealing temperature and duration of annealing that presents the best photosensitivity for the films is discussed. C1 TEXAS A&M UNIV,DEPT CHEM,COLLEGE STN,TX 77843. RP Garcia, VM, UNIV NACL AUTONOMA MEXICO,IIM,LAB ENERGIA SOLAR,PHOTOVOLTAIC SYST GRP,TEMIXCO 62580,MORELOS,MEXICO. CR BOUDREAU RA, 1983, J ELECTROCHEM SOC, V130, P513 BUBE RH, 1992, PHOTOELECTRONIC PROP, P83 CHOPRA KL, 1982, PHYS THIN FILMS, V12, P201 FOFANOV GM, 1969, RUSS J INORG CHEM, V14, P322 HODES G, 1987, PHYS REV B, V36, P4215 KAINTHLA RC, 1980, J ELECTROCHEM SOC, V127, P277 LOFERSKI JJ, 1956, J APPL PHYS, V27, P777 LOKHANDE CD, 1991, MATER CHEM PHYS, V127, P1 MICHELETTI FB, 1967, APPL PHYS LETT, V10, P136 MOSKOVITS M, 1990, CHEM PHYSICS ATOMIC, P397 NAIR MTS, 1988, THIN SOLID FILMS, V161, P21 NAIR MTS, 1993, J APPL PHYS, V74, P1879 NAIR MTS, 1993, J ELECTROCHEM SOC, V140, P2987 NAIR MTS, 1994, J APPL PHYS, V75, P1557 ORTON JW, 1982, J APPL PHYS, V53, P1602 PRINCE MB, 1955, J APPL PHYS, V26, P534 REICHMAN J, 1984, J ELECTROCHEM SOC, V131, P796 SVECHNIKOV SV, 1980, THIN SOLID FILMS, V66, P41 SZE SM, 1981, PHYS SEMICONDUCTOR D, P848 NR 19 TC 15 PU IOP PUBLISHING LTD PI BRISTOL PA TECHNO HOUSE, REDCLIFFE WAY, BRISTOL, ENGLAND BS1 6NX SN 0268-1242 J9 SEMICOND SCI TECHNOL JI Semicond. Sci. Technol. PD MAR PY 1996 VL 11 IS 3 BP 427 EP 432 PG 6 SC Engineering, Electrical & Electronic; Materials Science, Multidisciplinary; Physics, Condensed Matter GA TZ797 UT ISI:A1996TZ79700022 ER PT J AU Hu, H Campos, J Nair, PK TI Electrically conductive CuS-poly(acrylic acid) composite coatings SO JOURNAL OF MATERIALS RESEARCH LA English DT Article ID SOLAR CONTROL COATINGS; THIN-FILMS AB Copper sulfide (CuS) powder precipitated from a chemical bath containing Cu(II) chloride and thiourea and annealed in air at 150 degrees C for 1 h was dispersed in a poly(acrylic acid) aqueous solution (with additional water or propylene glycol as a dispersive agent) and cast on glass slides. Upon evaporation of the solvent, coatings of similar to 50 mu m in thickness of a CuS-poly(acrylic acid) composite are formed. Measurement of sheet resistance (R(square)) indicates a percolation threshold of electrical conduction at a weight fraction [wf is wt. % of CuS to poly(acrylic acid) + CuS] of about 40%; the composite undergoes a transition from insulator (R(square) similar to 10(13) Ohm) to conductive state (R(square) similar to 10(2) Ohm). The morphology and thermal stability of the composite depend on the choice of the dispersive agent for the CuS powder; smoother and thermally stable (up to a temperature of 250 degrees C) coatings are obtained when propylene glycol is used. The results on x-ray diffraction, thermogravimetric analysis, and Fourier transform infrared spectroscopy studies are given to indicate the structure and bonding mechanisms and their dependence on temperature and dispersive agents. RP Hu, H, UNIV NACL AUTONOMA MEXICO,PHOTOVOLTAIC SYST GRP,LAB ENERGIA SOLAR,IIM,TEMIXCO 62580,MORELOS,MEXICO. CR AGNIHOTRI OP, 1981, SOLAR SELECTIVE SURF, P115 AILWARD GH, 1974, SI CHEM DATA, P112 BEE TG, 1993, POLYM SURFACES INTER, V2, P37 BERGMAN DJ, 1989, PHYSICA A, V157, P72 CARMONA F, 1989, PHYSICA A, V157, P461 CASTANO VM, 1993, ADV TOPICS MAT SCI E, P103 DELTON D, 1983, MACROMOLECULES, V16, P1143 ESTRADAGASCA CA, 1993, J PHYS D APPL PHYS, V26, P1304 GREENBERG AR, 1977, J POLYM SCI POL CHEM, V15, P2137 HEEGER AJ, 1993, P 81 NOB S, P27 HU H, 1992, THESIS FS NATL U MEX HU H, 1995, IN PRESS SURF COATIN KOSS RS, 1987, PHYS REV B, V35, P9004 MATSUMOTO H, 1980, JPN J APPL PHYS, V14, P129 MAYCOCK PD, 1981, PHOTOVALTAICS SUNLIG, P39 NAIR MTS, 1989, SEMICOND SCI TECH, V4, P191 NAIR PK, 1991, J PHYS D APPL PHYS, V24, P441 NAIR PK, 1993, J ELECTROCHEM SOC, V140, P754 OKAMOTO K, 1973, JPN J APPL PHYS, V12, P1130 PADILLA A, 1991, J MATER RES, V6, P2452 SANIGER JM, 1993, HDB CHARACTERIZATION, P169 SEBASTIAN PJ, 1994, SOL ENERG MAT SOL C, V32, P159 SICHEL EK, 1982, CARBON BLACK POLYM C SVORCIK V, 1994, J MATER RES, V9, P643 NR 24 TC 13 PU MATERIALS RESEARCH SOCIETY PI PITTSBURGH PA 9800 MC KNIGHT ROAD SUITE 327, PITTSBURGH, PA 15237 SN 0884-2914 J9 J MATER RES JI J. Mater. Res. PD MAR PY 1996 VL 11 IS 3 BP 739 EP 745 PG 7 SC Materials Science, Multidisciplinary GA TY914 UT ISI:A1996TY91400024 ER PT J AU Sebastian, PJ Fernandez, AM Sanchez, A TI Formation of CuInSe2 thin films by selenization, employing CVTG, of electroless deposited Cu-In alloy SO SOLAR ENERGY MATERIALS AND SOLAR CELLS LA English DT Article AB Formation of CuInSe2 (CIS) thin films combining two low cost and large area techniques, viz. electroless and chemical vapor transport by gas (CVTG), is reported for the first time. This process consisted of Cu-In alloy deposition by electroless followed by high temperature selenization of the alloy employing CVTG. The alloy phase consisted mainly of Cu11In9 (JCPDs 41-0883) alloy. Selenization of the alloy at 400 degrees C resulted in the formation of cubic CuInSe2 (JCPDS 23-207) with alpha-Cu2Se (JCPDS 24-1131) as the secondary phase. This method offers the possibility of CIS based low cost polycrystalline solar cells. RP Sebastian, PJ, UNIV NACL AUTONOMA MEXICO,PHOTOVOLTA SYST GRP,SLOAR ENERGY LAB,IIM,TEMXICO 65280,MORELOS,MEXICO. CR GARG JC, 1988, THIN SOLID FILMS, V164, P269 GUPTA A, 1994, SOL ENERG MAT SOL C, V32, P137 JONES PA, 1994, THIN SOLID FILMS, V238, P4 KUMAR SR, 1992, SOL ENERG MAT SOL C, V26, P149 LAKSHMIKUMAR ST, 1994, SOL ENERG MAT SOL C, V32, P7 PAL R, 1994, SOL ENERG MAT SOL C, V33, P241 PERN FJ, 1991, THIN SOLID FILMS, V202, P299 ROCKETT A, 1994, THIN SOLID FILMS, V237, P1 SACHAN V, 1993, SOL ENERG MAT SOL C, V30, P147 SANCHEZ A, 1995, SEMICOND SCI TECH, V10, P87 STOLT M, 1993, 11TH P EC PHOT SOL E SUBRAMANIAN PR, 1989, B ALLOY PHASE DIAGR, V10, P554 TUTTLE JR, 1993, 7TH P SUNSH PROJ THI VARELA M, 1986, J PHYS D APPL PHYS, V19, P127 YAMANAKA BE, 1993, 23RD P IEEE PVSC LOU NR 15 TC 8 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0927-0248 J9 SOLAR ENERG MATER SOLAR CELLS JI Sol. Energy Mater. Sol. Cells PD NOV PY 1995 VL 39 IS 1 BP 55 EP 60 PG 6 SC Energy & Fuels; Materials Science, Multidisciplinary GA TQ008 UT ISI:A1995TQ00800008 ER PT J AU George, PJ Sanchez, A Nair, PK Huang, L TI Properties of chemically deposited CdS thin films converted to n-type by indium diffusion SO JOURNAL OF CRYSTAL GROWTH LA English DT Article ID CADMIUM-SULFIDE AB Structural, optical and electrical properties of chemically deposited CdS thin films (300 nm thickness), converted to n-type by thermal diffusion of indium are presented. CdS thin films were deposited at 80 degrees C for 4 h from a chemical bath containing citratocadmium ions and thiourea. The diffusion of indium from a source of evaporated thin indium film (10-40 nm thickness) on the surface of CdS film was carried out by heating the sample in air at 250-350 degrees C for 1-4 h. X-ray diffraction spectra of the films indicate the formation of a surface layer of In2O3 during the heat treatment. X-ray photoelectron spectroscopy studies show that, with the oxide film acting as a diffusion barrier, indium diffuses into the CdS thin film leading to the conversion of the chemically deposited intrinsic photosensitive CdS thin film to n-type with conductivity up to 50 Ohm(-1) cm(-1). Optical transmittance spectra of the films indicate that the n-type CdS films formed in this way retain the basic features of the spectra of chemically deposited CdS thin films, notably an optical band gap > 2.5 eV. C1 KURUKSHETRA UNIV,DEPT ELECTR SCI,KURUKSHETRA 132119,HARYANA,INDIA. UNIV NACL AUTONOMA MEXICO,LAB ENERGIA SOLAR,IIM,PHOTOVOLTAIC SYST GRP,TEMIXCO 62580,MORELOS,MEXICO. TEXAS A&M UNIV,DEPT CHEM,COLLEGE STN,TX 77843. CR BASOL BM, 1993, NREL1993 PHOT SUBC P, P126 BEROT G, 1982, 16TH P IEEE PHOT SPE, P872 BERTRAN E, 1988, SOLAR ENERGY MATER, V17, P55 BHARDWAJ RC, 1984, SOL CELLS, V12, P371 CHOPRA KL, 1982, PHYS THIN FILMS, V12, P167 CHU TL, 1993, ADV SOLAR ENERGY, V8, P271 DANAHER WJ, 1985, SOL ENERG MATER, V12, P137 FAHRENBRUCH AL, 1983, FUNDAMENTALS SOLAR C, P55 GAO W, 1992, 11TH P EC PHOT SOL E, P921 GUPTA D, 1988, DIFFUSION PHENOMENA, P1 KIM SY, 1993, THIN SOLID FILMS, V229, P227 NAIR MTS, 1988, THIN SOLID FILMS, V161, P21 NAIR MTS, 1994, J APPL PHYS, V75, P1557 NAIR PK, 1987, SOL CELLS, V22, P221 NAIR PK, 1988, SEMICOND SCI TECH, V3, P134 ORTON JW, 1982, J APPL PHYS, V53, P1602 STEVENSON AW, 1984, ACTA CRYSTALLOGR B, V40, P521 STOLT L, 1992, 11TH P EC PHOT SOL E, P120 VELTHAUS KO, 1992, 11TH P EC PHOT SOL E, P842 NR 19 TC 8 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-0248 J9 J CRYST GROWTH JI J. Cryst. Growth PD JAN PY 1996 VL 158 IS 1-2 BP 53 EP 60 PG 8 SC Crystallography GA TP326 UT ISI:A1996TP32600008 ER PT J AU Huang, L Nair, PK Nair, MTS Zingaro, RA Meyers, EA TI Chemical deposition of Bi2S3 thin films on glass substrates pretreated with organosilanes SO THIN SOLID FILMS LA English DT Article DE deposition process; glass; organic substances; bismuth; sulfide ID BISMUTH SULFIDE; MONOLAYERS; CUXS AB The chemical deposition of Bi2S3 thin films on glass substrates modified by treatment with solutions of 3-mercaptopropyltrimethoxysilane and 3-aminopropyltrimethoxysilane is described. Such treatment helps prevent the peeling of thin films, a problem which is otherwise encountered in the chemical deposition process. Uniform thin films having thicknesses up to 0.32 mu m were obtained on the modified surfaces. X-ray photoelectron spectroscopy was employed to demonstrate that silanization takes place at the surfaces of the glass substrates. The relative atomic concentrations of nitrogen or sulfur on these surfaces increase with the time of immersion in the silanizing solutions. X-ray diffraction patterns of air-annealed Bi2S3 thin films were obtained. Optical transmittance and photoconductivity were measured and compared with those of the thin films deposited on untreated glass substrates. It was found that the thin films deposited on the silanized substrates were stable at 200 degrees C and maintain their original physical characteristics. C1 UNIV NACL AUTONOMA MEXICO,IIM,ENERGIA SOLAR LAB,PHOTOVOLTA SYST GRP,TEMIXCO 62580,MORELOS,MEXICO. RP Huang, L, TEXAS A&M UNIV,DEPT CHEM,COLLEGE STN,TX 77843. CR 1990, XRAY POWDER DIFFRACT ALLARA DL, 1985, LANGMUIR, V1, P52 ANGST DL, 1991, LANGMUIR, V7, P2236 BHATTACHARYA RN, 1982, J ELECTROCHEM SOC, V129, P332 BHATTACHARYA RN, 1982, SOL ENERG MATER, V6, P317 BISWAS S, 1986, J ELECTROCHEM SOC, V133, P48 CAPOZZI G, 1974, CHEM THIOL GROUP 2, P785 CHOPRA KL, 1982, PHYS THIN FILMS, V12, P201 GARCIA VM, 1992, SOLAR ENERGY MATER, V23, P47 GLATZ AC, 1963, J ELECTROCHEM SOC, V110, P1231 HARDA RH, 1956, PHYS REV, V102, P1258 HUANG L, 1995, PHOSPHORUS SULFUR, V103, P77 LIDE DR, 1990, CRC HDB CHEM PHYSICS, P12 LINDBERG BJ, 1970, PHYSICA SCRIPTA, V1, P286 MAOZ R, 1984, J COLLOID INTERF SCI, V100, P465 MOSKOVITS M, 1990, CHEM PHYSICS ATOMIC, P397 NAIR MTS, 1989, SEMICOND SCI TECH, V4, P191 NAIR MTS, 1990, SEMICOND SCI TECH, V5, P1225 NAIR MTS, 1993, J ELECTROCHEM SOC, V140, P212 NAIR PK, 1987, SOL CELLS, V22, P103 NAIR PK, 1991, SEMICOND SCI TECH, V6, P393 NAIR PK, 1992, SEMICOND SCI TECH, V7, P239 NAIR PK, 1993, J ELECTROCHEM SOC, V140, P1085 NAIR PK, 1993, J ELECTROCHEM SOC, V140, P754 ORTON JW, 1987, J APPL PHYS, V20, P51 PAULSON S, 1992, ACS NW REGIONAL M MI WAGNER CD, 1978, HDB XRAY PHOTOELECTR, P182 WEISER K, 1976, PROG SOLID STATE CHE, V11, P403 NR 28 TC 11 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE 1 PA PO BOX 564, 1001 LAUSANNE 1, SWITZERLAND SN 0040-6090 J9 THIN SOLID FILMS JI Thin Solid Films PD NOV 1 PY 1995 VL 268 IS 1-2 BP 49 EP 56 PG 8 SC Materials Science, Multidisciplinary; Materials Science, Coatings & Films; Physics, Applied; Physics, Condensed Matter GA TL765 UT ISI:A1995TL76500010 ER PT J AU Alvarez, G Estrada, CA TI Transient heat conduction in a glass with chemically deposited SnS-CuxS solar control coating SO RENEWABLE ENERGY LA English DT Article AB The transient thermal performance of a chemically deposited thin film on a glass substrate is presented. Differential energy balances for the glass are set up assuming a one-dimensional transient state for normal incidence of the air mass to solar radiation. Using the reported properties of a SnS-CuxS thin him as a specific example, the net energy flow through a glass and the specific film were calculated for a time period. The effect of absorption in the film is specifically considered. The theoretical time histories of the surface temperatures of the glass plus solar control coating and the clear glass are plotted for an exterior temperature range of 0-50 degrees C. The redistribution to the interior and exterior of the absorbed component of the solar radiation as well as the shading coefficient in time are evaluated for a constant convective heat transfer coefficient for ambient temperatures of 30 and 20 degrees C. Also, the time constant of the system is given. C1 UNAM,INST INVEST MAT,ENERGIA SOLAR LAB,TERMIXCO 62580,MORELOS,MEXICO. RP Alvarez, G, CTR NACL INVEST & DESARROLLO TECNOL,CENIDET,DGIT,SEP,AP 5-164,CUERNAVACA 62050,MORELOS,MEXICO. CR 1977, HDB FUNDAMENTALS ESTRADAGASCA CA, 1993, J PHYS D APPL PHYS, V26, P1304 ESTRADAGASCA CA, 1993, RENEW ENERG, V3, P683 NAIR MTS, 1991, J PHYS D APPL PHYS, V24, P450 NAIR MTS, 1993, J ELECTROCHEM SOC, V140, P212 NAIR PK, 1989, J PHYS D APPL PHYS, V22, P829 NR 6 TC 2 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0960-1481 J9 RENEWABLE ENERGY JI Renew. Energy PD NOV PY 1995 VL 6 IS 8 BP 1023 EP 1027 PG 5 SC Energy & Fuels GA TL500 UT ISI:A1995TL50000014 ER PT J AU PORCAYOCALDERON, J MARTINEZ, L TI SILICON-BASED THERMAL-SPRAYED COATINGS IN UTILITY BOILER COMPONENTS SO MATERIALS PERFORMANCE LA English DT Article AB The performance of thermal-sprayed coatings applied to uncooled components installed in the high-temperature zone of a 300-MW boiler was investigated. The environment in the boiler is highly corrosive because of the burning of heavy fuel oil with high contents of vanadium, sodium, and sulfur. The additive feeder components coated by thermal spraying were exposed to a gas temperature of 1100-degrees-C during approximately 3240 hours. A nickel-chromium silicon-iron two-layer based coating demonstrated the best performance. Details of the microstructure in the interfaces between the coating and the corrosive environment and of the coating and the base metal are discussed. C1 UNIV AUTONOMA CAMPECHE,PROGRAMA CORROSION GOLFO MEXICO,CUERVANACA 62191,MORELOS,MEXICO. RP PORCAYOCALDERON, J, INST INVESTIGACIONES ELECTRICAS,DEPT QUIM APLICADA,AP 475,CUERNAVACA 62000,MORELOS,MEXICO. NR 0 TC 1 PU NATL ASSN CORROSION ENG PI HOUSTON PA 1440 SOUTH CREEK DRIVE, HOUSTON, TX 77084-4906 SN 0094-1492 J9 MATER PERFORM JI Mater. Perform. PD DEC PY 1995 VL 34 IS 12 BP 32 EP 37 PG 6 SC Materials Science, Characterization & Testing GA TJ305 UT ISI:A1995TJ30500010 ER PT J AU SEBASTIAN, PJ SANCHEZ, A FERNANDEZ, AM TI CUINSE2 BASED SOLAR-CELL STRUCTURES BY CVTG SO APPLIED ENERGY LA English DT Article AB Chemical vapor transport by gas (CVTG) is a new method to grow semi-conductor thin films, transparent conductors and hence solar cell structures economically. This technique can be divided into (1) reactive CVTG (RCVTG), and (2) condensation CVTG (CCVTG). In the present study CuInSe2 film is formed by RCVTG and a CdS film is deposited by CCVTG to form solar cell structures like Mo/CIS/CdS/SnO2. Electroless deposited Ctl-ln alloy, the precursor, was subjected to selenization at 500 degrees C by an RCVTG method to produce the CIS film. The CdS film is deposited by CCVTG. Initial results show promising cell parameters for CVTG deposited CIS based solar cell structures. Detailed studies are in progress to characterize the influence of CVTG deposited CIS and CdS film properties on cell efficiency and other cell parameters. RP SEBASTIAN, PJ, UNAM,IIM,SOLAR ENERGY LAB,PHOTOVOLTA SYST GRP,TEMIXCO 62580,MORELOS,MEXICO. CR BILODEAU S, 1988, PHYS REV B, V37, P3275 GUPTA A, 1994, SOL ENERG MAT SOL C, V32, P137 JAYAKRISHNAN R, 1994, SEMICOND SCI TECH, V9, P97 ROCKETT A, 1994, THIN SOLID FILMS, V237, P1 SANCHEZ A, 1995, SEMICOND SCI TECH, V10, P87 STOLT L, 1993, 11TH P EC PHOT SOL E SUBRAMANIAN PR, 1989, B ALLOY PHASE DIAGR, V10, P554 TUTTLE JR, 1993, 7TH P SUNSH PROJ THI YAMANAKA S, 1993, 23RD P IEEE PVSC LOU NR 9 TC 3 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, OXON, ENGLAND OX5 1GB SN 0306-2619 J9 APPL ENERG JI Appl. Energy PY 1995 VL 52 IS 2-3 BP 199 EP 207 PG 9 SC Energy & Fuels; Engineering, Chemical GA TE864 UT ISI:A1995TE86400010 ER PT J AU SEBASTIAN, PJ TI ZNCDS FILMS FOR SOLAR-CELL AND PHOTODETECTOR APPLICATIONS DEPOSITED BY IN-SITU CHEMICAL DOPING OF CDS WITH ZN SO ADVANCED MATERIALS FOR OPTICS AND ELECTRONICS LA English DT Article DE ZNCDS; CDS; ZNS; PHOTODETECTOR; CHEMICAL DOPING ID ZNXCD1-XS THIN-FILMS; PHOTOCONDUCTIVITY; MORPHOLOGY; SULFIDE; BATH AB ZnCdS films were formed by in situ chemical doping of CdS with Zn in a chemical bath, The X-ray diffraction (XRD) patterns of CdS films after Zn doping showed a more disordered nature, consisting of reflections from Zn0.049Cd0.951S (JCPDS 40-834) as well as CdS greenockite (hexagonal, JCPDS 41-1049) and hawleyite (cubic, JCPDS 10-0454) phases, A comparison of the optical transmittance spectra for undoped and Zn-doped films showed that the cut-off wavelength was modified after Zn doping, indicating the presence of impurity states in the band gap. Zn-doped films showed an increase in dark conductivity after annealing at about 200 degrees C. These films exhibit promising characteristics for application in solar cell and photodetector structures. RP SEBASTIAN, PJ, UNAM,IIM,EUERGIA SOLAR LAB,PHOTOVOLTA SYST GRP,TEMIXCO 62580,MORELOS,MEXICO. CR CALL RL, 1980, SOL ENERG MATER, V2, P373 CALL RL, 1980, SOL ENERG MATER, V2, P373 DANAHER WJ, 1985, SOL ENERG MATER, V12, P137 FERNANDEZ AM, 1993, J PHYS D APPL PHYS, V26, P2001 GORDILLO G, 1992, SOL ENERG MAT SOL C, V25, P41 KAUR I, 1980, J ELECTROCHEM SOC, V127, P943 KITAEV GA, 1965, ZH FIZ KHIM+, V39, P1101 MOKRUSHIN SG, 1961, COLLOID J USSR, V23, P336 MONDAL A, 1983, SOL ENERG MATER, V7, P431 MORRIS GC, 1992, SOL ENERG MAT SOL C, V26, P217 NAGAO M, 1968, JPN J APPL PHYS, V7, P684 PAVASKAR NR, 1977, J ELECTROCHEM SOC, V124, P743 SEBASTIAN PJ, 1992, ADV MATER OPT ELECTR, V1, P211 SEBASTIAN PJ, 1993, ADV MATER OPT ELECTR, V2, P133 SEBASTIAN PJ, 1993, APPL PHYS LETT, V62, P2956 SEBASTIAN PJ, 1993, THIN SOLID FILMS, V227, P190 SEBASTIAN PJ, 1995, ADV MATER OPT ELECTR, V5, P11 TORRES J, 1992, THIN SOLID FILMS, V207, P231 NR 18 TC 3 PU JOHN WILEY & SONS LTD PI W SUSSEX PA BAFFINS LANE CHICHESTER, W SUSSEX, ENGLAND PO19 1UD SN 1057-9257 J9 ADV MATER OPT ELECTRON JI Adv. Mater. Opt. Electron. PD SEP-OCT PY 1995 VL 5 IS 5 BP 269 EP 275 PG 7 SC Chemistry, Applied; Engineering, Electrical & Electronic; Materials Science, Multidisciplinary; Optics GA TC810 UT ISI:A1995TC81000004 ER PT J AU JIMENEZGONZAILEZ, AE NAIR, PK TI PHOTOSENSITIVE ZNO THIN-FILMS PREPARED BY THE CHEMICAL-DEPOSITION METHOD SILAR SO SEMICONDUCTOR SCIENCE AND TECHNOLOGY LA English DT Article ID IONIC-LAYER ADSORPTION; MECHANISM; GROWTH; CDS AB Structural, optical and photoresponse characteristics of ZnO thin films (similar to 0.1 mu m) prepared by a relatively new chemical deposition method, SILAR (successive ion layer adsorption and reaction), are described. The films are deposited by successive immersion of glass substrate in a dilute solution of Zn2+-ammonia complex at room temperature and in hot water (96 degrees C) for up to 35 immersion cycles using a computerized electropneumatic deposition system. Film thickness varied from 0.02 mu m (6 cycles) to 0.11 mu m (35 cycles). The as-prepared films show hexagonal (zincite) structure with a preferred orientation-c-axis perpendicular to the plane of glass substrate-but lose this preferential orientation when annealed at 350 degrees C. An optical transmittance of 90% combined with a specular reflectance of 10% in the visible and near-infrared region is typical of these films. The as-prepared films show a photocurrent to dark current ratio of 10(5) under 900 W m(-2) illumination from a solar simulator. The dark conductivity and photoconductivity are influenced by heat treatments in controlled atmospheres (O-2, H-2 and air). RP JIMENEZGONZAILEZ, AE, UNIV NACL AUTONOMA MEXICO,IMM,ENERGIA SOLAR LAB,PHOTOVOLTAIC SYST GRP,TEMIXICO 62580,MORELOS,MEXICO. CR BASOL BM, 1993, 1991 ANN REP PHOT SU BELT RF, 1968, J APPL PHYS, V39, P5251 CHOPRA KL, 1983, THIN SOLID FILMS, V102, P1 HODES G, 1987, PHYS REV B, V36, P4215 JIN ZC, 1987, P SOC PHOTO-OPT INS, V21, P823 LEHMANN HW, 1973, J APPL PHYS, V44, P3868 MINAMI T, 1984, JPN J APPL PHYS PT 2, V23, L280 NAIR PK, 1988, SEMICOND SCI TECH, V3, P134 NICOLAU YF, 1985, APPL SURF SCI, V22, P1061 NICOLAU YF, 1988, J CRYST GROWTH, V92, P128 NICOLAU YF, 1990, J ELECTROCHEM SOC, V137, P2915 OLEAROGEL A, 1994, AUTOMATIC SYSTEM CHE ORTON JW, 1982, J APPL PHYS, V53, P1602 PETROU P, 1979, APPL PHYS LETT, V35, P930 RISTOV M, 1985, THIN SOLID FILMS, V123, P63 SCHAEFFERT RM, 1980, ELECTROPHOTOGRAPHY, P320 SOULETIE P, 1988, J CRYST GROWTH, V86, P248 SZE SM, 1981, PHYSICS SEMICONDUCTO, P849 TOMAR MS, 1982, THIN SOLID FILMS, V90, P419 VASANELLI L, 1987, SOL ENERG MATER, V16, P91 ZAVYALOVA LM, 1979, ZH FIZ KHIM, V53, P2125 NR 21 TC 29 PU IOP PUBLISHING LTD PI BRISTOL PA TECHNO HOUSE, REDCLIFFE WAY, BRISTOL, ENGLAND BS1 6NX SN 0268-1242 J9 SEMICOND SCI TECHNOL JI Semicond. Sci. Technol. PD SEP PY 1995 VL 10 IS 9 BP 1277 EP 1281 PG 5 SC Engineering, Electrical & Electronic; Materials Science, Multidisciplinary; Physics, Condensed Matter GA RU519 UT ISI:A1995RU51900013 ER PT J AU BARRAGAN, RM HEARD, C ARELLANO, VM BEST, R HOLLAND, FA TI EXPERIMENTAL PERFORMANCE OF THE WATER-LITHIUM CHLORIDE SYSTEM IN A HEAT TRANSFORMER SO INTERNATIONAL JOURNAL OF ENERGY RESEARCH LA English DT Article DE HEAT TRANSFER; WATER LITHIUM CHLORIDE AB Heat tranformers are devices with the unique capability of raising the temperature of part of a low-grade heat source whilst simultaneously delivering the rest of the heat at a lower temperature. The gross temperature lift that could be attained in the process depends on the characteristics of the working pair. Many combinations of working fluid/absorbent have been proposed although until now the water/lithium bromide system is the most widely used. In order to study the performance of combinations of environmentally friendly working pairs, an absorption heat transformer was constructed and tested. The experimental equipment is described in this work. The performance of the water/lithium chloride system is discussed. The results showed that gross temperature lifts of more than 30 degrees C can be obtained for absorber temperatures higher than 110 degrees C. The enthalpic coefficient of performance indicated that more than 45% of the waste heat can be upgraded for flow ratios less than 10. RP BARRAGAN, RM, INST INVEST ELECT,DEPT GEOTERMIA,APDO POSTAL 475,CUERNAVACA 6200,MORELOS,MEXICO. NR 0 TC 2 PU JOHN WILEY & SONS LTD PI W SUSSEX PA BAFFINS LANE CHICHESTER, W SUSSEX, ENGLAND PO19 1UD SN 0363-907X J9 INT J ENERG RES JI Int. J. Energy Res. PD SEP PY 1995 VL 19 IS 7 BP 593 EP 602 PG 10 SC Energy & Fuels; Nuclear Science & Technology GA RT368 UT ISI:A1995RT36800004 ER PT J AU BIJKER, R FRANK, A TI ALGEBRAIC-EIKONAL APPROACH TO MEDIUM-ENERGY PROTON-SCATTERING FROM ODD-MASS NUCLEI SO PHYSICAL REVIEW C LA English DT Article ID INTERACTING BOSON MODEL; COLLECTIVE STATES; FERMION MODEL; LIMIT AB We extend the algebraic-eikonal approach to medium energy proton scattering from odd-mass nuclei by combining the eikonal approximation for the scattering with a description of odd-mass nuclei in terms of the interacting boson-fermion model. We derive closed expressions for the transition matrix elements for one of the dynamical symmetries and discuss the interplay between collective and single-particle degrees of freedom in an application to elastic and inelastic proton scattering from Pt-195. C1 INST FIS,CUERNAVACA LAB,CUERNAVACA 62191,MORELOS,MEXICO. RP BIJKER, R, NATL AUTONOMOUS UNIV MEXICO,INST CIENCIAS NUCL,APARTADO POSTAL 70543,MEXICO CITY 04510,DF,MEXICO. CR AMADO RD, 1982, PHYS REV C, V25, P13 BIJKER R, 1985, ANN PHYS-NEW YORK, V161, P360 BRUTON EJ, 1970, NUCL PHYS A, V152, P495 GINOCCHIO JN, 1986, PHYS REV C, V33, P247 GINOCHIO JN, 1988, PHYS REV C, V36, P2436 IACHELLO F, 1987, INTERACTING BOSON MO IACHELLO F, 1991, INTERACTING BOSE FER SETHI A, 1990, NUCL PHYS A, V518, P536 SETHI A, 1991, PHYS REV C, V44, P700 VANISACKER P, 1984, ANN PHYS-NEW YORK, V157, P183 WENES G, 1984, NUCL PHYS A, V424, P81 WENES G, 1986, NUCL PHYS A, V459, P631 NR 12 TC 2 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2813 J9 PHYS REV C JI Phys. Rev. C PD AUG PY 1995 VL 52 IS 2 BP 831 EP 836 PG 6 SC Physics, Nuclear GA RQ227 UT ISI:A1995RQ22700047 ER PT J AU SEBASTIAN, PJ TI FORMATION OF TRANSPARENT AND PHOTO CONDUCTING FILMS BY HIGH-TEMPERATURE CHEMICAL CONVERSION OF SOLUTION-GROWN PRECURSOR FILMS SO MATERIALS AND MANUFACTURING PROCESSES LA English DT Article ID SPRAY PYROLYSIS; OXIDE FILMS; ZNO FILMS; DEPOSITION; ZNSE AB The formation of photoconducting ZnO and transparent conducting CdO films by high temperature oxidation and thermal decomposition of chemically deposited ZnS and Cd(OH)(2) precursor films respectively is reported. The ZnS to ZnO and Cd(OH)(2) to CdO conversions were confirmed by x-ray diffraction (XRD), electrical and optoelectronic studies. As deposited ZnS and Cd(OH)(2) films exhibited very low dark conductivity and no photoconductivity. Air oxidation of ZnS films at about 400 degrees C for at least 15 minutes converted them to ZnO films with higher dark and photoconductivity. Cd(OB)(2) to CdO conversion occurred at about 300 degrees C. CdO films exhibited a dark conductivity of the order of 10(3) (Omega cm)(-1) and an optical transmittance in the range of 90%. These characteristics of ZnO and CdO films make them suitable candidates for the development of low cost photoconductors and solar cell structures. C1 UNAM,IIM,SOLAR ENERGY LAB,PHOTOVOLTA SYST GRP,TEMIXCO 62580,MORELOS,MEXICO. CR AMBERSELY MD, 1981, THIN SOLID FILMS, V80, P183 ARANOVICH J, 1979, J VAC SCI TECHNOL, V16, P994 BUCHANAN M, 1980, APPL PHYS LETT, V37, P213 CHAMPNESS CH, 1981, SOL ENERG MATER, V5, P391 CHU TL, 1983, J APPL PHYS, V54, P398 CHU TL, 1990, J ELECTRON MATER, V19, P1003 CURIE D, 1967, PHYSICS CHEM 2 6 COM, CH9 ISHIH I, 1982, SOL CELLS, V7, P327 KOCKA J, 1971, PHYS STATUS SOLIDI B, V43, P731 KUNIOKA A, 1968, JPN J APPL PHYS, V7, P1138 MAJOR S, 1983, THIN SOLID FILMS, V108, P333 MENESES EA, 1983, PHYSICA B & C, V117, P160 MORGAN JH, 1982, CAN J PHYS, V60, P1387 ORTIZ A, 1988, SEMICOND SCI TECH, V3, P537 ORTIZ A, 1989, J ELECTROCHEM SOC, V136, P1232 SARAVANI C, 1992, SEMICOND SCI TECH, V6, P1036 SHIMIZU M, 1985, J CRYST GROWTH, V71, P209 SMITH JF, 1980, THIN SOLID FILMS, V72, P469 SZEPESI Z, 1974, J ELECTRON MATER, V7, P515 VANGOOL W, 1960, PHILIPS RES REP, V15, P238 YIM WM, 1972, J ELECTROCHEM SOC, V119, P381 NR 21 TC 0 PU MARCEL DEKKER INC PI NEW YORK PA 270 MADISON AVE, NEW YORK, NY 10016 SN 1042-6914 J9 MATER MANUF PROCESS JI Mater. Manuf. Process. PY 1995 VL 10 IS 4 BP 795 EP 805 PG 11 SC Engineering, Manufacturing; Materials Science, Multidisciplinary GA RM356 UT ISI:A1995RM35600012 ER PT J AU SIQUEIROS, J HEARD, CL HOLLAND, FA TI THE COMMISSIONING OF AN INTEGRATED HEAT PUMP-ASSISTED GEOTHERMAL BRINE PURIFICATION SYSTEM SO HEAT RECOVERY SYSTEMS & CHP LA English DT Article AB In a previous work, a packaged commercial heat pump was coupled to a geothermal brine purification system. Subsequently, a new compact heat pump-assisted purification system was fabricated which involved the elimination of two heat exchangers and a reduction in the amount of tubing; this resulted in higher efficiencies due to lower temperature differences in the heat exchangers. The quality of the distilled water obtained from the geothermal brine was similar to commercially available distilled water with respect to chlorides and silica. A coefficient of performance (COP) of 4.5 was achieved with a brine boiling temperature of 63 degrees C. Higher COPs could be achieved with a higher compressor efficiency. The process shows considerable promise for future development. RP SIQUEIROS, J, INST INVEST ELECT,DIV FUENTES ENERGIA,CUERNAVACA,MORELOS,MEXICO. NR 0 TC 5 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0890-4332 J9 HEAT RECOV SYST CHP JI Heat Recovery Syst. CHP PD OCT PY 1995 VL 15 IS 7 BP 655 EP 664 PG 10 SC Thermodynamics; Energy & Fuels; Engineering, Mechanical; Mechanics GA RL507 UT ISI:A1995RL50700006 ER PT J AU GONZALEZRODRIGUEZ, G SALINASBRAVO, V LOPEZHUESCA, J MARTINEZVILLAFANE, A TI EFFECT OF MOLTEN-SALTS ON THE CREEP RESISTANCE OF 304-TYPE STAINLESS-STEEL SO REVISTA DE METALURGIA LA Spanish DT Article DE HOT CORROSION; MOLTEN SALTS; CREEP; SUPERHEATER; REHEATER; RESIDUAL LIFE ID HOT CORROSION; TEMPERATURE AB Problems caused by both hot corrosion and creep type-damage occuring on superheater and reheater tubes of power plants using heavy oil as fuel shorten their design lives. The acceleration of hot corrosion attack of boilers is caused by the presence of fuel ash deposits containing mainly vanadium, sodium and sulphur, in the form of Na2SO4 and V2O5 which form low melting point compounds. In addition to this, the tubes are exposed to the action of both high stresses and high temperatures, producing the so called creep damage. In this work, creep rupture tests were carried out in the temperature range of 620 to 660 degrees C in static air and in corrosive environments. The corrosive environments included 100% Na2SO4, 100% V2O5 and a 80% V2O5 + 20% Na2SO4 mixture. C1 INST INVEST ELECT,DPTO FISICOQUIM APLICADA,CUERNAVACA 62000,MORELOS,MEXICO. CTR INVEST MAT AVANZADOS,CHIHUAHUA,MEXICO. CR AHILA S, 1993, T INDIAN I METALS, V46, P215 JONES RL, 1988, HIGH TEMP TECHNOL, V6, P187 KOFSTAD P, 1984, P S HIGH TEMP CORR C, P207 NICHOLLS JR, 1979, P INT C PETTEN, P911 OH SY, 1994, 8TH INT C OFFSH MECH, P187 STRINGER J, 1985, HIGH TEMP TECHNOL, V3, P119 SURYANARAYANAN V, 1989, MAT SCI ENG A-STRUCT, V112, P107 SWAMINATHAN J, 1992, MAT HIGH TEMP, V10, P242 WONG A, 1987, 9 INT C MAT TECHN SA, P339 YOSHIBA M, 1986, INT C CREEP JSME TOK, P193 NR 10 TC 0 PU CENIM PI MADRID PA AVDA. GREGORIO DEL AMO, 8, 28040 MADRID, SPAIN SN 0034-8570 J9 REV METALURGIA JI Rev. Metal. PD MAY-JUN PY 1995 VL 31 IS 3 BP 166 EP 171 PG 6 SC Metallurgy & Metallurgical Engineering GA RK612 UT ISI:A1995RK61200004 ER PT J AU ESTRADA, CA MEYERS, EA ZINGARO, RA DUFNER, DC NAIR, PK NAIR, MTS TI ELECTRON AND X-RAY-DIFFRACTION STUDIES OF CHEMICALLY DEPOSITED THIN-FILMS OF CADMIUM SELENIDE FOLLOWING REACTION WITH MERCURY(II) CHLORIDE SOLUTION SO HETEROATOM CHEMISTRY LA English DT Article AB The reaction between thin films of CdSe and aqueous HgCl2 was studied using electron diffraction (ED) powder X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). It was found that alpha-Hg3Se2Cl2 is formed in the CdSe film following its reaction with 0.01 M HgCl2 for a period of 5 minutes. Upon completion of the reaction of CdSe powder with 0.01 M HgCl2, Hg2Cl2 is present in addition to alpha-Hg3Se2Cl2 in a molar ratio of 1:3.1. The effect of air annealing on CdSe powder was also studied. Heating in air to 450 degrees C for 1 hour resulted in an XRD pattern corresponding to the hexagonal form CdSe. C1 TEXAS A&M UNIV,DEPT CHEM,COLLEGE STN,TX 77843. TEXAS A&M UNIV,CTR ELECTRON MICROSCOPY,COLLEGE STN,TX 77843. UNIV NACL AUTONOMA MEXICO,IIM,ENERGIA SOLAR LAB,TEMIXCO 62580,MORELOS,MEXICO. CR 1990, XRAY POWDER PATTERN BRIGGS D, 1983, PRACTICAL SURFACE AN CHIZHIKOV DM, 1966, CADMIUM DONNAY JDH, 1963, CRYSTAL DATA DETERMI FRUEH AJ, 1968, ACTA CRYSTALLOGR B, V24, P156 NAIR MTS, 1993, J APPL PHYS, V74, P1879 NAIR MTS, 1994, J ELECTROCHEM SOC, V140, P2987 NARAYAN C, 1986, J ELECTRON MICR TECH, V3, P151 PUFF H, 1962, NATURWISSENSCHAFTEN, V49, P299 PUFF H, 1962, NATURWISSENSCHAFTEN, V49, P299 WAGMAN DD, 1982, J PHYS CHEM REF D S2, V11 WAGNER CD, 1978, HDB XRAY PHOTOELECTR NR 12 TC 1 PU VCH PUBLISHERS INC PI DEERFIELD BEACH PA 303 NW 12TH AVE, DEERFIELD BEACH, FL 33442-1788 SN 1042-7163 J9 HETEROATOM CHEM JI Heteroatom Chem. PD JUL-AUG PY 1995 VL 6 IS 4 BP 349 EP 354 PG 6 SC Chemistry, Multidisciplinary GA RJ787 UT ISI:A1995RJ78700011 ER PT J AU HERION, P GURROLABRIONES, G SANCHEZ, MDR SAAVEDRA, R POSSANI, LD TI MONOCLONAL-ANTIBODIES AGAINST NOXIUSTOXIN SO HYBRIDOMA LA English DT Article ID SCORPION CENTRUROIDES-NOXIUS; K+ CHANNEL BLOCKER; POTASSIUM CHANNELS; SYNTHETIC PEPTIDES; CHARYBDOTOXIN; PURIFICATION; TOXIN; VENOM; NEUROTOXINS; ACTIVATION AB Noxiustoxin, a 39-amino acid residue peptide isolated from the venom of the Mexican scorpion Centruroides noxius, has previously been shown to affect voltage-dependent K+ channels, Here we describe the isolation and characterization of monoclonal antibodies (MAbs) against this toxin and their use in structure-function relationship studies. Six hybridoma clones (BNTX4, -12, -14, -16, -18, and -21) producing MAbs against noxiustoxin were isolated, The epitopes defined by the MAbs are overlapping or in close proximity because no MAb pair could bind simultaneously to the toxin. All the MAbs inhibited to various degrees the binding of the toxin to its receptor sites on rat brain synaptosomal membranes. The venom from other Centruroides species was shown to contain components cross-reacting with the MAbs, suggesting the existence of other NTX-like toxins. C1 UNAM,INST BIOTECNOL,DEPT BIOQUIM,CUERNAVACA 62271,MORELOS,MEXICO. NATL AUTONOMOUS UNIV MEXICO,INST INVEST BIOMED,DEPT IMMUNOL,MEXICO CITY 04510,DF,MEXICO. NATL AUTONOMOUS UNIV MEXICO,INST INVEST BIOMED,DEPT MOLEC BIOL,MEXICO CITY 04510,DF,MEXICO. CR CARBONE E, 1982, NATURE, V296, P90 CARBONE E, 1987, PFLUG ARCH EUR J PHY, V408, P423 CASTLE NA, 1989, TRENDS NEUROSCI, V12, P59 CATTERALL WA, 1977, J BIOL CHEM, V252, P8669 CATTERALL WA, 1979, J BIOL CHEM, V254, P11359 COURAUD F, 1982, TOXICON, V20, P9 FRANSSEN JD, 1981, PROTIDES BIOL FLUIDS, V29, P645 GARCIACALVO M, 1993, J BIOL CHEM, V268, P18866 GURROLA GB, 1989, J NEURAL TRANSM, V77, P11 HERION P, 1981, PROTIDES BIOL FLUIDS, V29, P627 HERION P, 1983, BIOSCIENCE REP, V3, P381 KEKWICK RA, 1936, BIOCHEM J 1, V30, P227 MARTIN BM, 1994, BIOCHEM J, V304, P51 MILLER C, 1985, NATURE, V313, P316 MIRANDA F, 1970, EUR J BIOCHEM, V16, P514 MORRISON M, 1970, BIOCHEMISTRY-US, V9, P2995 OSULLIVAN MJ, 1981, METHOD ENZYMOL, V73, P147 OUCHTERLONY O, 1948, ACTA PATHOL MIC SC, V25, P186 POSSANI LD, 1982, CARLSBERG RES COMMUN, V47, P285 POSSANI LD, 1984, HDB NATURAL TOXINS, V2, P513 PRESTIPINO G, 1989, FEBS LETT, V250, P570 SANDS SB, 1989, J GEN PHYSIOL, V93, P1061 SITGES M, 1986, J NEUROSCI, V6, P1570 STAEHELIN T, 1981, J BIOL CHEM, V256, P9750 VACA L, 1993, J MEMBRANE BIOL, V134, P123 VALDIVIA HH, 1988, FEBS LETT, V226, P280 VALDIVIA HH, 1992, BIOCHEM INT, V27, P953 VAZQUEZ J, 1990, J BIOL CHEM, V265, P15564 ZAMUDIO F, 1992, EUR J BIOCHEM, V204, P281 ZLOTKIN E, 1978, HDB EXPT PHARMACOLOG, V48, P317 NR 30 TC 13 PU MARY ANN LIEBERT INC PUBL PI LARCHMONT PA 2 MADISON AVENUE, LARCHMONT, NY 10538 SN 0272-457X J9 HYBRIDOMA JI Hybridoma PD JUN PY 1995 VL 14 IS 3 BP 247 EP 251 PG 5 SC Biochemical Research Methods; Biotechnology & Applied Microbiology; Immunology GA RF575 UT ISI:A1995RF57500006 ER PT J AU CEAOLIVARES, R TOSCANO, RA SILVESTRU, C GARCIAGARCIA, P LOPEZCARDOSO, M BLASSAMADOR, G NOTH, H TI SYNTHESIS AND STRUCTURAL CHARACTERIZATION OF PHENOXARSIN-10-YL DITHIOCARBAMATES - O(C6H4)(2)ASS2CN(CH2CH2)2, A COMPOUND CONTAINING AN ASYMMETRIC MONONUCLEAR BICONNECTIVE 1,1-DITHIOLATO LIGAND SO JOURNAL OF ORGANOMETALLIC CHEMISTRY LA English DT Article DE ARSENIC; DITHIOCARBAMATES; PHENOXARSINE; GROUP 15 ID SULFUR-CONTAINING LIGANDS; HETEROCYCLES 1,3-DITHIA-2-ARSA-CYCLOPENTANES; COORDINATING ABILITY; STIBA-CYCLOPENTANES; COMPLEXES; CRYSTAL AB Phenoxarsin-10-yl dithiocarbamates O(C6H4)(2)AsS(2)CX (X = NMe(2), NEt(2), N(CH2CH)(2), N(CH2CH2)(2) or N[(CH2)(3)CH(CH3)CH2]) have been prepared by the reaction between O(C6H4)(2)AsCl and sodium dithiocarbamates. The compounds were characterized by IR, mass and NMR (H-1 and C-13) spectroscopy. The molecular structure of O(C6H4)(2)AsS2CN(CH2CH2)(2) was determined using single-crystal X-ray diffraction. The compound is monomeric and contains an asymmetric monometallic biconnective dithiocarbamato unit (As-S(1), 2.277(1), Angstrom; As...S(2), 3.183(3) Angstrom. The double-bond character of the C-N bond (1.318(5) Angstrom) is in agreement with the NMR data. The dihedral angle (155.2 degrees) of the phenoxarsine moiety is almost unaffected by substitution of chlorine by the dithiocarbamato ligand. C1 UNIV AUTONOMA MORELOS,FAC QUIM,CUERNAVACA,MORELOS,MEXICO. UNIV MUNICH,INST ORGAN CHEM,D-80333 MUNICH,GERMANY. RP CEAOLIVARES, R, NATL AUTONOMOUS UNIV MEXICO,IST QUIM,CIRCUITO EXTERIOR,CIUDAD UNIV,MEXICO CITY 04510,DF,MEXICO. CR 1989, SIEMENS SHELXTL PLUS BALLY R, 1967, ACTA CRYSTALLOGR, V23, P295 BALLY R, 1970, CR HEBD ACAD SCI, V271, P1436 BEURSKENS G, 1979, RECL TRAV CHIM PAY B, V98, P416 BHATTACHARYA S, 1994, Z NATURFORSCH B, V49, P193 BONATI F, 1967, J ORGANOMET CHEM, V10, P257 CEAOLIVARES R, 1990, MONATSH CHEM, V121, P377 CEAOLIVARES R, 1993, HETEROATOM CHEM, V4, P313 CEAOLIVARES R, 1993, MAIN GROUP MET CHEM, V16, P121 CEAOLIVARES R, 1993, MONATSH CHEM, V124, P177 CEAOLIVARES R, 1994, J CHEM SOC DA, P1881 COLAPIETRO M, 1968, J CHEM SOC CHEM COMM, P302 COUCOUVANIS D, 1970, PROGR INORG CHEM, V11, P233 COUCOUVANIS D, 1979, PROG INORG CHEM, V26, P301 CRAS JA, 1977, RECL TRAV CHIM PAY B, V96, P78 GAVRILOV VI, 1991, J GEN CHEM USSR, V61, P2055 GAVRILOV VI, 1991, ZH OBSHCH KHIM, V61, P2213 GLEU K, 1950, ANGEW CHEM, V62, P320 GRINDSTAFF WK, 1972, INORG CHEM, V11, P1852 JAIN JK, 1994, J ORGANOMET CHEM, V468, P279 MEYERS EA, 1987, PHOSPHORUS SULFUR, V29, P317 MEYERS EA, 1987, PHOSPHORUS SULFUR, V29, P317 PAULING L, 1960, NATURE CHEM BOND, P189 RASTON CL, 1975, J CHEM SOC DA, P2425 REGER DL, 1990, ORGANOMETALLICS, V9, P16 SHRIVER DF, 1990, INORG CHEM, P68 STUCKEY JE, 1972, INORG CHEM, V11, P1846 TOU JC, 1970, ORG MASS SPECTROM, V3, P287 NR 28 TC 10 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE 1 PA PO BOX 564, 1001 LAUSANNE 1, SWITZERLAND SN 0022-328X J9 J ORGANOMETAL CHEM JI J. Organomet. Chem. PD MAY 17 PY 1995 VL 493 IS 1-2 BP 61 EP 67 PG 7 SC Chemistry, Inorganic & Nuclear; Chemistry, Organic GA QX753 UT ISI:A1995QX75300009 ER PT J AU SALINASBRAVO, VM GONZALEZRODRIGUEZ, JG TI STRESS-CORROSION CRACKING SUSCEPTIBILITY OF 17-4PH TURBINE STEEL IN AQUEOUS ENVIRONMENTS SO BRITISH CORROSION JOURNAL LA English DT Article AB The susceptibility of a 17-4PH type steel to stress corrosion cracking (SCC) in low pressure steam turbine environments was assessed using slow strain I rate testing. Environments onments tested included concentrated solutions of NaCl and NaOH at 90 degrees C. The effects of NaCl solution pH, additions of CuO and Cu2O, and cathodic and anodic polarisation were also investigated. It was concluded that this steel is susceptible to SCC in acidic NaCl solutions, under unpolarised conditions and under anodic or cathodic polarisation. In NaOH solutions, the steel was not susceptible to SCC at cathodic or anodic potentials. Addition of copper oxides to the NaCl and NaOH solutions was nor found to promote susceptibility to SCC. It is concluded that both hydrogen embrittlement and anodic dissolution mechanisms are responsible for the SCC susceptibility of the steel tested. C1 INST INVEST ELECT,DEPT QUIM FIS APLICADA,CUERNAVACA 62000,MORELOS,MEXICO. CR BROWN BF, 1977, THEORY STRESS CORROS, P186 MCMINN A, 1991, P C CORROSION 91 CIN POURBAIX M, 1977, THEORY STRESS CORROS, P17 STAEHLE RW, 1977, STRESS CORROSION CRA, P151 STAEHLE RW, 1977, STRESS CORROSION CRA, P351 STELTZ WG, 1980, P WESTINGHOUSE STEAM TROIANO AR, 1960, T ASM, V52, P151 NR 7 TC 2 PU INST MATERIALS PI LONDON PA 1 CARLTON HOUSE TERRACE, LONDON, ENGLAND SW1Y 5DB SN 0007-0599 J9 BRIT CORROS J JI Br. Corros. J. PY 1995 VL 30 IS 1 BP 77 EP 79 PG 3 SC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering GA QX420 UT ISI:A1995QX42000012 ER PT J AU CEAOLIVARES, R TOSCANO, RA ESTRADA, M SILVESTRU, C GARCIA, PGY LOPEZCARDOSO, M BLASSAMADOR, G TI SYNTHESIS AND CHARACTERIZATION OF PHENOXARSIN-10-YL 2-R(2)N-CYCLOPENT-1-ENE-1-CARBODITHIOATE (R=H, C2H5 CYCLO-C6H11CH2) AND THE CRYSTAL AND MOLECULAR-STRUCTURE OF THE 2-AMINO (R=H) DERIVATIVE SO APPLIED ORGANOMETALLIC CHEMISTRY LA English DT Article DE PHENOXARSINE; ACDA; CARBODITHIOATES; ARSENIC ID NITROGEN CHELATING-AGENTS; 2-AMINOCYCLOPENTENE-1-DITHIOCARBOXYLIC ACID COMPLEXES; METAL-COMPLEXES; 2-ALKYLAMINOCYCLOPENTENE-1-CARBODITHIOIC ACIDS; ESTERS; CO(III); NI(II); PD(II); PT(II); LIGAND AB Phenoxarsin-10-yl derivatives of cyclopent-1-ene-1-carbodithioic acid, and its N-alkyl derivatives O(C6H4)(2)AsS2C-C5H6 NHR-2 (R=H, CH2CH3, CH2C6H11), have been prepared by reacting O(C6H4)(2)AsCl with the corresponding ACDA 1,1-dithioic acid. The compounds were obtained by stirring stoichiometric amounts of the reagents in ethanol, over 24 h, at room temperature. The scale of the preparations were in the order of 2 mmol and the yields of the compounds ca 75%. The reactions were carried out in absolute ethanol. The compounds were characterized by IR, mass and NMR (H-1, C-13) spectroscopy. The molecular structure of O(C6H4)(2)AsS2C-C5H6-NH2-2 was determined using X-ray diffractometry, achieving an R-value of 6.3%; this compound is monomeric and contains an asymmetric monometallic biconnective 1,1-dithiolato ligand [As-S(1) 2.272(2) Angstrom, As...S(2) 3.125(2) Angstrom]. An intramolecular hydrogen bond is established between one hydrogen atom of the NH2 group and the sulfur [S(2)] atom involved in the secondary interaction to arsenic. The dihedral angle (150.3(3)degrees) of the phenoxarsine moiety is practically unaffected by substitution of chlorine on arsenic by the carbodithioato ligand. C1 UNIV AUTONOMA MORELOS,FAC QUIM,CUERNAVACA,MORELOS,MEXICO. RP CEAOLIVARES, R, UNIV NACL AUTONOMA MEXICO,INST QUIM,CIRCUITO EXTERIOR,CIUDAD UNIV,MEXICO CITY,DF,MEXICO. CR BHARADWAJ PK, 1987, INORG CHEM, V26, P1453 BONATI F, 1967, J ORGANOMET CHEM, V10, P257 BORDAS B, 1972, J ORG CHEM, V34, P1727 CEAOLIVARES R, IN PRESS J ORGANOMET CEAOLIVARES R, 1993, MAIN GROUP MET CHEM, V16, P121 CEAOLIVARES R, 1994, J CHEM SOC DA, P1881 GAVRILOV VI, 1991, J GEN CHEM USSR, V61, P2055 HAIDUC I, 1989, ORGANOMETALLICS CANC, V1, P185 MATOLCSY G, 1970, ACTA PHYTOPATHOL, V5, P123 MEYERS EA, 1987, PHOSPHORUS SULFUR, V29, P317 MIYAMAE H, 1985, ACTA CRYSTALLOGR C, V41, P1489 NAG K, 1975, INORG CHIM ACTA, V14, P133 NAG K, 1975, Z NATURFORSCH B, V30, P107 NAG K, 1976, CAN J CHEM, V54, P2827 NAG K, 1976, INORG CHIM ACTA, V17, P111 PAULING L, 1960, NATURE CHEM BOND, P189 SHELDRICK GM, SHELXTL USER MANUAL SHRIVER DF, 1990, INORG CHEM, P68 SINGH SK, 1989, INDIAN J CHEM A, V28, P585 SINGH SK, 1989, INDIAN J CHEM A, V28, P771 SINGH SK, 1989, POLYHEDRON, V8, P633 SINGH SK, 1990, INDIAN J CHEM A, V29, P876 STUCKEY JE, 1972, INORG CHEM, V11, P1846 TOU JC, 1970, ORG MASS SPECTROM, V3, P287 NR 24 TC 6 PU JOHN WILEY & SONS LTD PI W SUSSEX PA BAFFINS LANE CHICHESTER, W SUSSEX, ENGLAND PO19 1UD SN 0268-2605 J9 APPL ORGANOMETAL CHEM JI Appl. Organomet. Chem. PD MAR PY 1995 VL 9 IS 2 BP 133 EP 140 PG 8 SC Chemistry, Applied; Chemistry, Inorganic & Nuclear GA QR192 UT ISI:A1995QR19200006 ER PT J AU FUENTES, BE MARTINEZ, H CISNEROS, C ALVAREZ, I DEURQUIJO, J TI ANGULAR-DISTRIBUTIONS OF H- FORMATION FROM INTERACTION OF H-2(+) WITH KR SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS LA English DT Article ID ELECTRON-CAPTURE; STATES; CS AB Differential cross sections were determined for the production of H- fragments produced by the collision of H2+ on Kr at projectile energies between 1.0 to 5.0 keV and for scattering angles from -4-degrees to 4-degrees. The H- distributions are observed to fit to the scaling law (1/E)d sigma/dOmega = F(E theta2), where E is the incident energy. Two structures found at 4.0 and 7.3 eV yield information about the production of H-. These are associated with the direct dissociation and predissociative states of H2+ interacting with the target. C1 UNAM,INST FIS,CUERNAVACA LAB,APARTADO POSTAL 139-B,CUERNAVACA 62191,MORELOS,MEXICO. UNAM,FAC CIENCIAS,DEPT FIS,COYOACAN 04570,MEXICO. WESLEYAN UNIV,DEPT PHYS,MIDDLETOWN,CT 06457. CR BRUIJN DP, 1984, CHEM PHYS, V85, P215 CISNEROS C, 1976, PHYS REV A, V14, P88 CISNEROS C, 1979, PHYS REV A, V19, P631 CISNEROS C, 1991, NUCL INSTRUM METH 1, V56, P285 LOS J, 1978, COLLISION SPECTROSCO, P289 PETERSON JR, 1984, PHYS REV A, V30, P2807 SIDIS V, 1984, CHEM PHYS, V85, P201 NR 7 TC 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-583X J9 NUCL INSTRUM METH PHYS RES B JI Nucl. Instrum. Methods Phys. Res. Sect. B-Beam Interact. Mater. Atoms PD FEB PY 1995 VL 95 IS 2 BP 158 EP 160 PG 3 SC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Atomic, Molecular & Chemical; Physics, Nuclear GA QG821 UT ISI:A1995QG82100002 ER EF