FN Thomson Reuters Web of Science™ VR 1.0 PT J AU Krissinel, EB Jellinek, J AF Krissinel, EB Jellinek, J TI 13-atom Ni-Al alloy clusters: Structures and dynamics SO INTERNATIONAL JOURNAL OF QUANTUM CHEMISTRY LA English DT Article ID LENNARD-JONES CLUSTERS; TRANSITION-METAL CLUSTERS; DENSITY-FUNCTIONAL THEORY; BIMETALLIC CLUSTERS; MOLECULAR-DYNAMICS; NICKEL CLUSTERS; IONIZATION-POTENTIALS; ELECTRONIC-STRUCTURE; REACTIVITY; EVAPORATION AB Structural and dynamical properties of model 13-atom NinAlm alloy clusters derived from a many-body potential are presented and discussed. Characterization of the structures corresponding to a given stoichiometric composition (i.e., chosen number of Ni and Al atoms) is carried out in terms of isomeric (geometric) forms and different distributions of the two types of atoms between the sites of a chosen isomer. We use the term homotops (''the same topography or geometry'') to label the structural forms that differ only by these distributions. The number and the energy spectra of the homotops are sensitive functions of the stoichiometric composition and isomeric form. Similarly to homogeneous clusters, alloy clusters undergo a solid-to-liquidlike transition as their energy is increased. Individual stages in the transition, such as isomerizations involving only surface atoms, isomerizations involving all atoms, surface melting (in a system as small as 13 atoms), and complete melting are identified and characterized. The actual occurrence of some or all of these stages in the meltinglike transition of a given cluster depends on the character of the energy spectra of its homotops, i.e., ultimately, on its stoichiometric composition. (C) 1997 John Wiley & Sons, Inc. C1 ARGONNE NATL LAB, DIV CHEM, ARGONNE, IL 60439 USA. RUSSIAN ACAD SCI, INST WATER & ENVIRONM PROBLEMS, SIBERIAN BRANCH, BARNAUL 656099, RUSSIA. NR 66 TC 70 Z9 70 U1 0 U2 4 PU WILEY-BLACKWELL PI MALDEN PA COMMERCE PLACE, 350 MAIN ST, MALDEN 02148, MA USA SN 0020-7608 J9 INT J QUANTUM CHEM JI Int. J. Quantum Chem. PD MAR 15 PY 1997 VL 62 IS 2 BP 185 EP 197 PG 13 WC Chemistry, Physical; Mathematics, Interdisciplinary Applications; Physics, Atomic, Molecular & Chemical SC Chemistry; Mathematics; Physics GA WK285 UT WOS:A1997WK28500007 ER PT J AU Nickerson, JM Goodman, M Lin, ZY Czelusniak, J Mian, IS AF Nickerson, JM Goodman, M Lin, ZY Czelusniak, J Mian, IS TI Predicted structure, function and evolution of the repeated domain present in interphotoreceptor binding protein (IRBP) and its homologs SO INVESTIGATIVE OPHTHALMOLOGY & VISUAL SCIENCE LA English DT Meeting Abstract C1 EMORY EYE CTR,ATLANTA,GA 30322. WAYNE STATE UNIV,DETROIT,MI 48201. LAWRENCE BERKELEY NATL LAB,DIV LIFE SCI MS 29 100,BERKELEY,CA 94720. NR 0 TC 0 Z9 0 U1 0 U2 0 PU LIPPINCOTT-RAVEN PUBL PI PHILADELPHIA PA 227 EAST WASHINGTON SQ, PHILADELPHIA, PA 19106 SN 0146-0404 J9 INVEST OPHTH VIS SCI JI Invest. Ophthalmol. Vis. Sci. PD MAR 15 PY 1997 VL 38 IS 4 BP 10 EP 10 PN 1 PG 1 WC Ophthalmology SC Ophthalmology GA WN186 UT WOS:A1997WN18600010 ER PT J AU Lu, ZL Sperling, G Beck, JR AF Lu, ZL Sperling, G Beck, JR TI Selective adaptation of three motion systems SO INVESTIGATIVE OPHTHALMOLOGY & VISUAL SCIENCE LA English DT Meeting Abstract C1 UNIV SO CALIF,LOS ANGELES,CA 90089. UNIV CALIF IRVINE,IRVINE,CA 92697. LAWRENCE LIVERMORE NATL LAB,DAVIS,CA 95616. NR 1 TC 2 Z9 2 U1 0 U2 0 PU LIPPINCOTT-RAVEN PUBL PI PHILADELPHIA PA 227 EAST WASHINGTON SQ, PHILADELPHIA, PA 19106 SN 0146-0404 J9 INVEST OPHTH VIS SCI JI Invest. Ophthalmol. Vis. Sci. PD MAR 15 PY 1997 VL 38 IS 4 BP 1105 EP 1105 PN 1 PG 1 WC Ophthalmology SC Ophthalmology GA WN186 UT WOS:A1997WN18601102 ER PT J AU Colitz, CMH Woychik, RP Wilkinson, JE AF Colitz, CMH Woychik, RP Wilkinson, JE TI Ocular and tumor phenotypes arising in insertional mutant line TGN3261RPW. SO INVESTIGATIVE OPHTHALMOLOGY & VISUAL SCIENCE LA English DT Meeting Abstract C1 N CAROLINA STATE UNIV,COLL VET MED,RALEIGH,NC 27695. OAK RIDGE NATL LAB,DIV BIOL,OAK RIDGE,TN 37831. UNIV TENNESSEE,COLL VET MED,KNOXVILLE,TN 37996. NR 0 TC 0 Z9 0 U1 0 U2 1 PU LIPPINCOTT-RAVEN PUBL PI PHILADELPHIA PA 227 EAST WASHINGTON SQ, PHILADELPHIA, PA 19106 SN 0146-0404 J9 INVEST OPHTH VIS SCI JI Invest. Ophthalmol. Vis. Sci. PD MAR 15 PY 1997 VL 38 IS 4 BP 1502 EP 1502 PN 1 PG 1 WC Ophthalmology SC Ophthalmology GA WN186 UT WOS:A1997WN18601499 ER PT J AU Nystuen, A Costeff, H BonneTamir, B Haider, N Mohrenweiser, H Stone, EM Sheffield, VC AF Nystuen, A Costeff, H BonneTamir, B Haider, N Mohrenweiser, H Stone, EM Sheffield, VC TI A syndrome involving optic atrophy demonstrates linkage disequilibrium with the ctg repeat in the 3' untranslated region of the myotonic dystrophy protein kinase gene SO INVESTIGATIVE OPHTHALMOLOGY & VISUAL SCIENCE LA English DT Meeting Abstract C1 UNIV IOWA,DEPT PEDIAT,IOWA CITY,IA 52242. UNIV IOWA,DEPT OPHTHALMOL,IOWA CITY,IA 52242. TEL AVIV UNIV,DEPT REHABIL MED,IL-69978 TEL AVIV,ISRAEL. TEL AVIV UNIV,DEPT HUMAN GENET,IL-69978 TEL AVIV,ISRAEL. LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550. NR 0 TC 0 Z9 0 U1 0 U2 0 PU LIPPINCOTT-RAVEN PUBL PI PHILADELPHIA PA 227 EAST WASHINGTON SQ, PHILADELPHIA, PA 19106 SN 0146-0404 J9 INVEST OPHTH VIS SCI JI Invest. Ophthalmol. Vis. Sci. PD MAR 15 PY 1997 VL 38 IS 4 BP 1822 EP 1822 PN 1 PG 1 WC Ophthalmology SC Ophthalmology GA WN186 UT WOS:A1997WN18601817 ER PT J AU Swiergiel, JJ Funderburgh, JL Justice, MJ Conrad, GW AF Swiergiel, JJ Funderburgh, JL Justice, MJ Conrad, GW TI The eye blebs mouse: Developmental defects in the cornea, lens and spinal cord SO INVESTIGATIVE OPHTHALMOLOGY & VISUAL SCIENCE LA English DT Meeting Abstract C1 KANSAS STATE UNIV,DIV BIOL,MANHATTAN,KS 66506. OAK RIDGE NATL LAB,DIV BIOL,OAK RIDGE,TN 37831. NR 0 TC 0 Z9 0 U1 0 U2 0 PU LIPPINCOTT-RAVEN PUBL PI PHILADELPHIA PA 227 EAST WASHINGTON SQ, PHILADELPHIA, PA 19106 SN 0146-0404 J9 INVEST OPHTH VIS SCI JI Invest. Ophthalmol. Vis. Sci. PD MAR 15 PY 1997 VL 38 IS 4 BP 2277 EP 2277 PN 1 PG 1 WC Ophthalmology SC Ophthalmology GA WN186 UT WOS:A1997WN18602270 ER PT J AU Rosenholtz, R AF Rosenholtz, R TI Basic signal detection theory model for visual search does not predict performance with heterogeneous distractors SO INVESTIGATIVE OPHTHALMOLOGY & VISUAL SCIENCE LA English DT Meeting Abstract C1 NASA,AMES RES CTR,AMES,IA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU LIPPINCOTT-RAVEN PUBL PI PHILADELPHIA PA 227 EAST WASHINGTON SQ, PHILADELPHIA, PA 19106 SN 0146-0404 J9 INVEST OPHTH VIS SCI JI Invest. Ophthalmol. Vis. Sci. PD MAR 15 PY 1997 VL 38 IS 4 BP 3204 EP 3204 PN 2 PG 1 WC Ophthalmology SC Ophthalmology GA WN215 UT WOS:A1997WN21500029 ER PT J AU Vibat, CRT Payne, JA Brandt, JD ODonnell, ME AF Vibat, CRT Payne, JA Brandt, JD ODonnell, ME TI Characterization of the Na-K-Cl cotransporter gene from human trabecular meshwork cells SO INVESTIGATIVE OPHTHALMOLOGY & VISUAL SCIENCE LA English DT Meeting Abstract C1 LAWRENCE LIVERMORE NATL LAB,DEPT HUMAN PHYSIOL,DAVIS,CA 95616. LAWRENCE LIVERMORE NATL LAB,DEPT OPHTHALMOL,DAVIS,CA 95616. NR 0 TC 0 Z9 0 U1 0 U2 0 PU LIPPINCOTT-RAVEN PUBL PI PHILADELPHIA PA 227 EAST WASHINGTON SQ, PHILADELPHIA, PA 19106 SN 0146-0404 J9 INVEST OPHTH VIS SCI JI Invest. Ophthalmol. Vis. Sci. PD MAR 15 PY 1997 VL 38 IS 4 BP 4871 EP 4871 PN 2 PG 1 WC Ophthalmology SC Ophthalmology GA WN215 UT WOS:A1997WN21501692 ER PT J AU Nash, KL AF Nash, KL TI f-Element complexation by diphosphonate ligands SO JOURNAL OF ALLOYS AND COMPOUNDS LA English DT Article; Proceedings Paper CT 21st Rare Earth Research Conference CY JUL 07-12, 1996 CL DULUTH, MN SP Rare Earth Res Conf Inc, Univ Minnesota, USR Optonix Inc, Amer Chem Soc, Petr Res Fund, Arris Int Corp, Baotou Steel & Rare Earth Co, US DE lanthanides; actinides; phosphonate chelating agents; thermodynamics; kinetics; crystal structure ID ACIDIC SOLUTIONS; STABILITY; IONS AB To develop a fundamental understanding of the nature of lanthanide and actinide coordination complexes with ligands bearing phosphonate groups, we have examined the kinetics, thermodynamics and spectroscopy of lanthanide and actinide complexes with phosphonate ligands in aqueous solutions and resolved crystal structures for selected lanthanide complexes. The combined results of two-phase distribution experiments, titration calorimetry, laser-induced fluorescence decay, and molecular mechanics modeling have been used to infer the structure of 1:2 complexes of Eu(III) with gem-diphosphonic acids in aqueous solution. PI complementary crystallographic and FTIR investigation of the structure of lanthanide complexes in the solid state indicates a general similarity between amorphous and crystalline complexes, differing in the relative hydration of the solid. There are no inner sphere water molecules in the solid state. Parallel studies of the kinetics of formation and dissociation of f-element diphosphonate complexes demonstrate that the relative stability of these complexes is governed primarily by differences in the rate of complex formation. A related investigation has established the existence of a correlation between complex formation rate and cationic radius which is independent of the charge. on the cation. RP Nash, KL (reprint author), ARGONNE NATL LAB, DIV CHEM, 9700 S CASS AVE, ARGONNE, IL 60439 USA. NR 25 TC 67 Z9 67 U1 0 U2 8 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0925-8388 J9 J ALLOY COMPD JI J. Alloy. Compd. PD MAR 15 PY 1997 VL 249 IS 1-2 BP 33 EP 40 DI 10.1016/S0925-8388(96)02520-0 PG 8 WC Chemistry, Physical; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Chemistry; Materials Science; Metallurgy & Metallurgical Engineering GA XC092 UT WOS:A1997XC09200008 ER PT J AU Jensen, MP Rickert, PG Schmidt, MA Nash, KL AF Jensen, MP Rickert, PG Schmidt, MA Nash, KL TI Stability constants of europium complexes with a nitrogen heterocycle substituted methane-1,1-diphosphonic acid SO JOURNAL OF ALLOYS AND COMPOUNDS LA English DT Article; Proceedings Paper CT 21st Rare Earth Research Conference CY JUL 07-12, 1996 CL DULUTH, MN SP Rare Earth Res Conf Inc, Univ Minnesota, USR Optonix Inc, Amer Chem Soc, Petr Res Fund, Arris Int Corp, Baotou Steel & Rare Earth Co, US DE europium; phosphonic acids; stability constants; protonation constants; solvent extraction ID METHANE DIPHOSPHONIC ACIDS; AQUEOUS-SOLUTIONS; NMR AB Even in moderately acidic solutions ([H+]>0.01 M), N-piperidinomethane-1,1-diphosphonic acid (H(4)PMDPA) is a strong complexant of trivalent lanthanide ions that shows enhanced complex solubility over previously studied 1,1-diphosphonic acids. The protonation constants of PMDPA in 2.0 M H/NaClO4 were determined by potentiometric and NMR titrations, and the stability constants for the formation of complexes with Eu3+ were determined by solvent extraction. The difference in protonation equilibria induced by the addition of the nitrogen heterocycle results in an increase in the complexation strength of PMDPA. In solutions containing 0.1 M H+ and ligand concentrations greater than 0.02 M, PMDPA is the most effective 1,1-diphosphonic acid for europium complexation studied thus far. RP Jensen, MP (reprint author), ARGONNE NATL LAB,DIV CHEM,9700 S CASS AVE,ARGONNE,IL 60439, USA. RI Jensen, Mark/G-9131-2012 OI Jensen, Mark/0000-0003-4494-6693 NR 19 TC 9 Z9 9 U1 0 U2 2 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0925-8388 J9 J ALLOY COMPD JI J. Alloy. Compd. PD MAR 15 PY 1997 VL 249 IS 1-2 BP 86 EP 90 DI 10.1016/S0925-8388(96)02829-0 PG 5 WC Chemistry, Physical; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Chemistry; Materials Science; Metallurgy & Metallurgical Engineering GA XC092 UT WOS:A1997XC09200016 ER PT J AU Giaquinta, DM Soderholm, L Yuchs, SE Wasserman, SR AF Giaquinta, DM Soderholm, L Yuchs, SE Wasserman, SR TI Hydrolysis of uranium and thorium in surface-modified bentonite under hydrothermal conditions SO JOURNAL OF ALLOYS AND COMPOUNDS LA English DT Article; Proceedings Paper CT 21st Rare Earth Research Conference CY JUL 07-12, 1996 CL DULUTH, MN SP Rare Earth Res Conf Inc, Univ Minnesota, USR Optonix Inc, Amer Chem Soc, Petr Res Fund, Arris Int Corp, Baotou Steel & Rare Earth Co, US ID ABSORPTION FINE-STRUCTURE; MONTMORILLONITE; SORPTION; SITES; CLAYS AB The speciation of (UO2)(2+)- and Th4+-exchanged bentonite clay samples was probed by X-ray absorption spectroscopy (XAS). Surface modification reactions using hydrophobic silanes were performed in order to ascertain the effects of excluding the free exchange of external water from the clay gallery. Hydrothermal conditions were used to mimic potential geologic conditions in a nuclear waste storage facility. Both the (UO2)(2+) and Th4+ samples showed evidence of polymeric hydrolysis products similar to the fluorite structure known for both UO2 and ThO2. RP Giaquinta, DM (reprint author), ARGONNE NATL LAB,DIV CHEM,9700 S CASS AVE,ARGONNE,IL 60439, USA. NR 34 TC 10 Z9 10 U1 0 U2 4 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0925-8388 J9 J ALLOY COMPD JI J. Alloy. Compd. PD MAR 15 PY 1997 VL 249 IS 1-2 BP 142 EP 145 DI 10.1016/S0925-8388(96)02823-X PG 4 WC Chemistry, Physical; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Chemistry; Materials Science; Metallurgy & Metallurgical Engineering GA XC092 UT WOS:A1997XC09200029 ER PT J AU Xu, W Peterson, JR AF Xu, W Peterson, JR TI Stabilization of divalent neodymium (Nd2+) in strontium tetraborate SO JOURNAL OF ALLOYS AND COMPOUNDS LA English DT Article; Proceedings Paper CT 21st Rare Earth Research Conference CY JUL 07-12, 1996 CL DULUTH, MN SP Rare Earth Res Conf Inc, Univ Minnesota, USR Optonix Inc, Amer Chem Soc, Petr Res Fund, Arris Int Corp, Baotou Steel & Rare Earth Co, US ID LUMINESCENCE PROPERTIES; CRYSTALLINE AB Luminescence and absorption spectra from SrB4O7:Nd2+ samples prepared from Nd2O3 (1 mol% based on Sr2+ ion mass) in air at high temperatures have been recorded at room temperature. A broad emission band centered in the vicinity of 560 nm has been observed from the samples upon excitation at 514.5 nm. We suggest that it is due to emission from the 5d band in Nd2+ ion into its ground state 4f level (I-5(4)). Analysis of absorption spectra recorded from the same samples support this conclusion. SrB4O7:Nd2+ samples prepared in Ar/H-2(4%) atmosphere exhibited more strongly the optical characteristics of Nd2+ ion compared to samples prepared in air. Several conditions promoting the stabilization of Nd2+ ion in this matrix are discussed. The range of f-element reducibility and stabilization in SrB4O7 has been extended from Tm2+ to Nd2+ in the present work; however, the limit of this facile reduction process has not yet been determined. C1 UNIV TENNESSEE,DEPT CHEM,KNOXVILLE,TN 37996. OAK RIDGE NATL LAB,DIV CHEM & ANALYT SCI,TRANSURANIUM RES LAB,OAK RIDGE,TN 37831. NR 21 TC 15 Z9 16 U1 0 U2 2 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0925-8388 J9 J ALLOY COMPD JI J. Alloy. Compd. PD MAR 15 PY 1997 VL 249 IS 1-2 BP 213 EP 216 DI 10.1016/S0925-8388(96)02637-0 PG 4 WC Chemistry, Physical; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Chemistry; Materials Science; Metallurgy & Metallurgical Engineering GA XC092 UT WOS:A1997XC09200041 ER PT J AU Soderholm, L Morss, LR AF Soderholm, L Morss, LR TI Proceedings of the Twenty-First Rare Earth Research Conference, Duluth, MN, USA, July 7-12, 1996 .1. Preface SO JOURNAL OF ALLOYS AND COMPOUNDS LA English DT Editorial Material RP Soderholm, L (reprint author), ARGONNE NATL LAB,9700 S CASS AVE,ARGONNE,IL 60439, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0925-8388 J9 J ALLOY COMPD JI J. Alloy. Compd. PD MAR 15 PY 1997 VL 249 IS 1-2 BP R11 EP R11 PG 1 WC Chemistry, Physical; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Chemistry; Materials Science; Metallurgy & Metallurgical Engineering GA XC092 UT WOS:A1997XC09200002 ER PT J AU Hecht, B Bielefeldt, H Inouye, Y Pohl, DW Novotny, L AF Hecht, B Bielefeldt, H Inouye, Y Pohl, DW Novotny, L TI Facts and artifacts in near-field optical microscopy SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID SPECTROSCOPY; RESOLUTION; FORCE; PROBE; TIP AB Near-field optical (NFO) microscopes with an auxiliary gap width regulation (shear force, tunneling) may produce images that represent the path of the probe rather than optical properties of the sample. Experimental and theoretical evidence leads us to the conclusion that many NFO results reported in the past might have been affected or even dominated by the resulting artifact. The specifications derived from such results for the different types of NFO microscopes used therefore warrant reexamination. We show that the resolving power of aperture NFO microscopes, 30-50 nm, is of genuine NFO origin but can be heavily obscured by the artifact. (C) 1997 American Institute of Physics. C1 OSAKA UNIV, SUITA, OSAKA 565, JAPAN. IBM CORP, DIV RES, ZURICH RES LAB, CH-8803 RUSCHLIKON, SWITZERLAND. PACIFIC NW LAB, RICHLAND, WA 99352 USA. RI Hecht, Bert/B-4996-2010; Inouye, Yasushi/N-7219-2013 OI Hecht, Bert/0000-0002-4883-8676; NR 42 TC 398 Z9 398 U1 1 U2 37 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 MAR 15 PY 1997 VL 81 IS 6 BP 2492 EP 2498 DI 10.1063/1.363956 PG 7 WC Physics, Applied SC Physics GA WP167 UT WOS:A1997WP16700005 ER PT J AU Ernst, P Zhang, Y Driessen, FAJM Mascarenhas, A Jones, ED Geng, C Scholz, F Schweizer, H AF Ernst, P Zhang, Y Driessen, FAJM Mascarenhas, A Jones, ED Geng, C Scholz, F Schweizer, H TI Magnetoluminescence study on the effective mass anisotropy of CuPtB-ordered GaInP2 alloys SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID LONG-RANGE ORDER; SEMICONDUCTOR ALLOYS; BAND; PHOTOLUMINESCENCE; GA0.52IN0.48P AB Photoluminescence measurements in a magnetic field between 0 and 13.6 T were carried out on CuPtB-ordered GaInP at liquid-helium temperature. Four samples of different degrees of ordering (eta, varying from 0 to 0.54) were studied. Experimental results show that the ordering not only induces a band-gap reduction and valence-band splitting, it also causes changes in effective masses and an effective mass anisotropy. By measuring and analyzing the magnetoluminescence with the magnetic field aligned along both ordering (the [(1) over bar 11]) and growth (the [001]) directions, we demonstrate that, for the band-edge excitonic state, the reduced mass in the plane perpendicular to the ordering direction is smaller than that in the ordering direction and also smaller than that of a disordered ahoy. The exciton binding energy is found nearly independent of the degree of ordering, in agreement with theoretical predictions. (C) 1997 American Institute of Physics. C1 NATL RENEWABLE ENERGY LAB, GOLDEN, CO 80401 USA. SANDIA NATL LABS, ALBUQUERQUE, NM 87185 USA. RP Ernst, P (reprint author), UNIV STUTTGART, INST PHYS 4, PFAFFENWALDRING 57, D-70550 STUTTGART, GERMANY. NR 17 TC 23 Z9 23 U1 0 U2 2 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 MAR 15 PY 1997 VL 81 IS 6 BP 2814 EP 2817 DI 10.1063/1.363938 PG 4 WC Physics, Applied SC Physics GA WP167 UT WOS:A1997WP16700058 ER PT J AU Smith, DL AF Smith, DL TI Steady state model for polymer light-emitting electrochemical cells SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID DIODES AB A model is presented for the steady state operation of polymer light-emitting electrochemical cells (LECs). An LEC consists of a luminescent and ionically conducting polymer, with an ionic salt added to provide ions necessary for p-type and n-type doping, sandwiched between two electrodes. Upon applying a sufficiently large voltage bias, the ions are spatially separated forming an electrical junction. Electrons injected from the n-type side of the junction recombine with holes injected from the p-type side of the junction emitting Light. We first describe the LEC at zero bias in which electric fields may occur in charge double layers near the contacts but in which there isa charge neutral, held free region in the device center which has an equal density of anions and cations and essentially dno electrons or holes. A threshold voltage for junction formation is found, which depends on the polymer energy gap, the dissociation free energy of the salt, and the added salt density. It is generally somewhat smaller than the polymer energy gap. Below threshold, an applied bias changes the electric fields in the double charge layers near the contacts but the device center remains held free and essentially no current flows. Above threshold, the ions become spatially separated, a junction forms, and current begins to how. Part of the applied voltage, above threshold, falls in the contact region and is necessary to establish the junction by electrochemical doping and part of the applied voltage falls across the junction. We describe the structure of the junction, which is quite different from that of a conventional p-n junction, including the spatial profiles of the electrons, holes, and ions, and the electrostatic potential. We discuss the current-voltage and capacitance-voltage characteristics of the LECs and show how they depend on the material parameters. (C) 1997 American Institute of Physics. RP Smith, DL (reprint author), LOS ALAMOS NATL LAB,POB 1663,LOS ALAMOS,NM 87545, USA. NR 16 TC 94 Z9 95 U1 1 U2 15 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 MAR 15 PY 1997 VL 81 IS 6 BP 2869 EP 2880 DI 10.1063/1.363966 PG 12 WC Physics, Applied SC Physics GA WP167 UT WOS:A1997WP16700068 ER PT J AU Wheeler, DL Campbell, AA Graff, GL Miller, GJ AF Wheeler, DL Campbell, AA Graff, GL Miller, GJ TI Histological and biomechanical evaluation of calcium phosphate coatings applied through surface-induced mineralization to porous titanium implants SO JOURNAL OF BIOMEDICAL MATERIALS RESEARCH LA English DT Article ID COATED IMPLANTS; PRESS-FIT; BONE; INGROWTH; GROWTH; TISSUE AB The purpose of this pilot study was to evaluate surface-induced mineralization (SIM) as a potential technique to apply ceramic coatings to metal orthopaedic implants. Cylindrical titanium porous-coated implants were either coated by SIM or plasma-spray (PLS) techniques with calcium phosphate, or left uncoated (CTL). The implants were bilaterally implanted into the intramedullary canal of the proximal femur of 24 adult New Zealand white rabbits segregated into the following groups: PLS/CTL, SIM/CTL, and SIM/PLS. After 6 weeks in vivo, biomechanical and histologic evaluations were completed. Biomechanically, SIM had consistently greater mechanical interlock than PLS implants. However, CTL implants had greater mechanical interlock than both PLS and SIM. The small sample size prevented statistical evaluation and definitive biomechanical conclusions. Histologically, SIM and PLS had significantly greater ingrowth than CTL implants (p < 0.05). The SIM coating technique produced similar ingrowth characteristics as standard PLS coatings, yet may prevent osteolysis by providing a stronger, more reliable, covalent bond between the ceramic and metal. (C) 1997 John Wiley & Sons, Inc. C1 PACIFIC NW LAB, DEPT CHEM & MAT SCI, RICHLAND, WA 99352 USA. UNIV FLORIDA, DEPT ORTHOPAED, GAINESVILLE, FL USA. RP Wheeler, DL (reprint author), OREGON HLTH SCI UNIV, DIV ORTHOPAED, 3181 SW SAM JACKSON PK RD, L477, PORTLAND, OR 97201 USA. NR 24 TC 13 Z9 13 U1 0 U2 2 PU JOHN WILEY & SONS INC PI NEW YORK PA 605 THIRD AVE, NEW YORK, NY 10158-0012 SN 0021-9304 J9 J BIOMED MATER RES JI J. Biomed. Mater. Res. PD MAR 15 PY 1997 VL 34 IS 4 BP 539 EP 543 DI 10.1002/(SICI)1097-4636(19970315)34:4<539::AID-JBM14>3.0.CO;2-7 PG 5 WC Engineering, Biomedical; Materials Science, Biomaterials SC Engineering; Materials Science GA WL332 UT WOS:A1997WL33200014 PM 9054537 ER PT J AU Voter, AF AF Voter, AF TI A method for accelerating the molecular dynamics simulation of infrequent events SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID TRANSITION-STATE THEORY; SURFACE SELF-DIFFUSION; EMBEDDED-ATOM METHOD; ISOMERIZATION DYNAMICS; COORDINATE DYNAMICS; LOW-TEMPERATURE; CONSTANTS; SYSTEMS; MULTISTATE; METALS AB For infrequent-event systems, transition state theory (TST) is a powerful approach for overcoming the time scale limitations of the molecular dynamics (MD) simulation method, provided one knows the locations of the potential-energy basins (states) and the TST dividing surfaces (or the saddle points) between them. Often, however, the states to which the system will evolve are not known in advance. We present a new, TST-based method for extending the MD time scale that does not require advanced knowledge of the states of the system or the transition states that separate them. The potential is augmented by a bias potential, designed to raise the energy in regions other than at the dividing surfaces. State to state evolution on the biased potential occurs in the proper sequence, but at an accelerated rate with a nonlinear time scale. Time is no longer an independent variable, but becomes a statistically estimated property that converges to the exact result at long times. The long-time dynamical behavior is exact if there are no TST-violating correlated dynamical events, and appears to be a good approximation even when this condition is not met. We show that for strongly coupled (i.e., solid state) systems, appropriate bias potentials can be constructed from properties of the Hessian matrix. This new ''hyper-MD'' method is demonstrated on two model potentials and for the diffusion of a Ni atom on a Ni(100) terrace for a duration of 20 mu s. (C) 1997 American Institute of Physics. RP Voter, AF (reprint author), LOS ALAMOS NATL LAB,DIV THEORET,LOS ALAMOS,NM 87545, USA. NR 51 TC 352 Z9 352 U1 3 U2 47 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD MAR 15 PY 1997 VL 106 IS 11 BP 4665 EP 4677 DI 10.1063/1.473503 PG 13 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA WM910 UT WOS:A1997WM91000031 ER PT J AU Peskin, U Reisler, H Miller, WH AF Peskin, U Reisler, H Miller, WH TI On the relation between unimolecular reaction rates and overlapping resonances - Response SO JOURNAL OF CHEMICAL PHYSICS LA English DT Letter C1 UNIV SO CALIF,DEPT CHEM,LOS ANGELES,CA 90089. UNIV CALIF BERKELEY,DEPT CHEM,BERKELEY,CA 94720. UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV CHEM SCI,BERKELEY,CA 94720. RP Peskin, U (reprint author), TECHNION ISRAEL INST TECHNOL,DEPT CHEM,IL-32000 HAIFA,ISRAEL. NR 4 TC 18 Z9 18 U1 0 U2 3 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD MAR 15 PY 1997 VL 106 IS 11 BP 4812 EP 4814 DI 10.1063/1.473990 PG 3 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA WM910 UT WOS:A1997WM91000048 ER PT J AU Hyman, J Shashkov, M Steinberg, S AF Hyman, J Shashkov, M Steinberg, S TI The numerical solution of diffusion problems in strongly heterogeneous non-isotropic materials SO JOURNAL OF COMPUTATIONAL PHYSICS LA English DT Article ID FINITE-DIFFERENCE SCHEMES; DISCONTINUOUS COEFFICIENTS; POROUS-MEDIA; EQUATIONS; SYSTEMS AB A new second-order finite-difference algorithm for the numerical solution of diffusion problems in strongly heterogeneous and nonisotropic media is constructed. On problems with rough coefficients or highly nonuniform grids, the new algorithm is superior to all other algorithms we have compared it with. For problems with smooth coefficients on smooth grids, the method is comparable with other second-order methods. The new algorithm is formulated for logically rectangular grids and is derived using the support-operators method. A key idea in deriving the method was to replace the usual inner product of vector functions by an inner product weighted by the inverse of the material properties tensor and to use the flux operator, defined as the material properties tensor times the gradient, rather than the gradient, as one of the basic first-order operators in the support-operators method. The discrete analog of the flux operator must also be the negative adjoint of the discrete divergence, in an inner product that is a discrete analog of the continuum inner product. The resulting method is conservative and the discrete analog of the variable coefficient Laplacian is symmetric and negative definite on nonuniform grids. In addition, on any grid, the discrete divergence is zero on constant vectors, the null space for the gradient is the constant functions, and, when the material properties are piecewise constant, the discrete flux operator is exact for piecewise linear functions. We compare the methods on some of the most difficult examples to be found in the literature. (C) 1997 Academic Press. C1 UNIV NEW MEXICO,DEPT MATH & STAT,ALBUQUERQUE,NM 87131. RP Hyman, J (reprint author), LOS ALAMOS NATL LAB,T-7,MS-B284,LOS ALAMOS,NM 87545, USA. NR 21 TC 124 Z9 126 U1 0 U2 5 PU ACADEMIC PRESS INC JNL-COMP SUBSCRIPTIONS PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 SN 0021-9991 J9 J COMPUT PHYS JI J. Comput. Phys. PD MAR 15 PY 1997 VL 132 IS 1 BP 130 EP 148 DI 10.1006/jcph.1996.5633 PG 19 WC Computer Science, Interdisciplinary Applications; Physics, Mathematical SC Computer Science; Physics GA WN889 UT WOS:A1997WN88900011 ER PT J AU Wong, J Froba, M Elmer, JW Waide, PA Larson, EM AF Wong, J Froba, M Elmer, JW Waide, PA Larson, EM TI In-situ phase mapping and transformation study in fusion welds SO JOURNAL OF MATERIALS SCIENCE LA English DT Article ID DIFFRACTION; DIFFUSION AB Spatially resolved X-ray diffraction (SRXRD) technique has been applied using synchrotron radiation to map the phases present in fusion welds in situ with a sub-millimetre resolution. For titanium, exhibiting an allotropic transformation from a hcp alpha-phase to a bcc beta-phase at similar to 922 degrees C, the following results have been obtained for the heat-affected zone (HAZ). (i) Go-existence of both alpha-and beta-Ti phases in the HAZ as derived from the phase concentration profiles. (ii) The width of the HAZ was found to be 3.33 +/- 0.33 mm as defined by the existence of the high-temperature bcc phase in this zone. (iii) Peak profile and ex-situ post-weld ESCA analyses revealed additional hcp patterns attributable to two TiOx phases formed in an overlayer during the welding process by oxygen diffusion from the ambient at high temperature. The thickness of this TiOx overlayer varied from 50-85 nm, increasing towards the weld pool. The SRXRD technique provides real-time chemical dynamics and in situ phase mapping data for modelling of kinetics of phase transformation and microstructural evolution in allotropic and other more complex systems, under steep thermal gradients and non-isothermal materials processing conditions. C1 GRAND CANYON UNIV,COLL SCI,PHOENIX,AZ 85107. RP Wong, J (reprint author), LAWRENCE LIVERMORE NATL LAB,POB 808,LIVERMORE,CA 94551, USA. RI Froba, Michael/B-2888-2010 NR 34 TC 24 Z9 24 U1 0 U2 5 PU CHAPMAN HALL LTD PI LONDON PA 2-6 BOUNDARY ROW, LONDON, ENGLAND SE1 8HN SN 0022-2461 J9 J MATER SCI JI J. Mater. Sci. PD MAR 15 PY 1997 VL 32 IS 6 BP 1493 EP 1500 DI 10.1023/A:1018514319714 PG 8 WC Materials Science, Multidisciplinary SC Materials Science GA WP164 UT WOS:A1997WP16400018 ER PT J AU Bowers, MW Boyd, RW Hankla, AK AF Bowers, MW Boyd, RW Hankla, AK TI Brillouin-enhanced four-wave-mixing vector phase-conjugate mirror with beam-combining capability SO OPTICS LETTERS LA English DT Article AB It is often desirable to remove both wave front and polarization aberrations from an optical beam. Scalar phase conjugation, such as ordinary stimulated Brillouin scattering, can correct only for wave-front aberrations. We have developed a new geometry for Brillouin-enhanced four-wave mixing that performs vector phase conjugation to correct for both wave-front and polarization distortions. Results show a reduction in the depolarization losses from 50% to less than 2% of the total output energy. Coherent, variable, multiple-beam combination is achieved without need of nonreciprocal devices such as Faraday rotators. (C) 1997 Optical Society of America. C1 LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94551. RP Bowers, MW (reprint author), UNIV ROCHESTER,INST OPT,ROCHESTER,NY 14627, USA. NR 13 TC 10 Z9 11 U1 0 U2 3 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 SN 0146-9592 J9 OPT LETT JI Opt. Lett. PD MAR 15 PY 1997 VL 22 IS 6 BP 360 EP 362 DI 10.1364/OL.22.000360 PG 3 WC Optics SC Optics GA WN458 UT WOS:A1997WN45800004 PM 18183201 ER PT J AU Szeles, C Shan, YY Lynn, KG Moodenbaugh, AR AF Szeles, C Shan, YY Lynn, KG Moodenbaugh, AR TI Trapping properties of cadmium vacancies in Cd1-xZnxTe SO PHYSICAL REVIEW B LA English DT Article ID CDTE; IDENTIFICATION; RESONANCE; EPR AB The trapping and thermal emission of holes were studied from a deep acceptor level created during thermal annealing of a Cd1-xZnxTe (x = 0.12) crystal grown by the high-pressure Bridgman (HPB) technique using thermoelectric-effect spectroscopy and thermally stimulated current experiments. The deep level, which is usually absent in as-grown HPB Cd1-xZnxTe crystals, is assigned to the 2-/- acceptor level of Cd (Zn) vacancies. The thermal ionization energy of the level is E(th) = (0.43 +/- 0.01) eV, and the trapping cross section of holes was found to be sigma = (2.0 +/- 0.2) x 10(-16) cm(-2). C1 BROOKHAVEN NATL LAB,UPTON,NY 11973. RP Szeles, C (reprint author), II VI INC,EV PROD DIV,SAXONBURG,PA 16056, USA. OI Moodenbaugh, Arnold/0000-0002-3415-6762 NR 23 TC 53 Z9 53 U1 2 U2 12 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 MAR 15 PY 1997 VL 55 IS 11 BP 6945 EP 6949 DI 10.1103/PhysRevB.55.6945 PG 5 WC Physics, Condensed Matter SC Physics GA WQ095 UT WOS:A1997WQ09500049 ER PT J AU Banin, U Cerullo, G Guzelian, AA Alivisatos, AP Shank, CV AF Banin, U Cerullo, G Guzelian, AA Alivisatos, AP Shank, CV TI Quantum confinement and ultrafast dephasing dynamics in InP nanocrystals SO PHYSICAL REVIEW B LA English DT Article ID CDSE NANOCRYSTALS; SIZE DEPENDENCE; DOTS; ABSORPTION; CLUSTERS; SPECTRUM; ELECTRON; STATES; WELLS AB The electronic level structure and dephasing dynamics of InP nanocrystals in the strong quantum-confinement regime are studied by two complementary techniques: nanosecond hole burning and the femto-second three-pulse photon echo. Hole burning yields the homogeneous electronic level structure while the photon echo allows the extraction of the linewidth of the band-gap transition. The congestion of electronic levels observed close to the band-edge transition in the hole-burning experiments gives rise to a pulse-width-limited initial decay in the photon-echo signal. The level structure is calculated and assigned using a model which includes valence band mixing. The homogeneous linewidth of the band-edge transition is approximately 5 meV at 20 K and is broadened considerably at higher temperatures. The temperature dependence of the linewidth is consistent with an intrinsic dephasing mechanism of coupling to low-frequency acoustic modes mediated by the deformation potential. Quantum-confinement effects in III-V semiconductor InP are compared to those of the prototypical CdSe II-VI semiconductor nanocrystal system. C1 LAWRENCE LIVERMORE NATL LAB, LIVERMORE, CA 94550 USA. UNIV CALIF BERKELEY, DEPT PHYS, BERKELEY, CA 94720 USA. RP Banin, U (reprint author), UNIV CALIF BERKELEY, DEPT CHEM, BERKELEY, CA 94720 USA. RI Cerullo, Giulio/F-6534-2011; Alivisatos , Paul /N-8863-2015; OI Alivisatos , Paul /0000-0001-6895-9048; Cerullo, Giulio/0000-0002-9534-2702 NR 37 TC 62 Z9 62 U1 5 U2 19 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 MAR 15 PY 1997 VL 55 IS 11 BP 7059 EP 7067 DI 10.1103/PhysRevB.55.7059 PG 9 WC Physics, Condensed Matter SC Physics GA WQ095 UT WOS:A1997WQ09500066 ER PT J AU Kellogg, GL AF Kellogg, GL TI Hydrogen promotion of surface self-diffusion on Rh(100) and Rh(311) SO PHYSICAL REVIEW B LA English DT Article ID BY-LAYER GROWTH; MEDIATED EPITAXIAL-GROWTH; METAL-SURFACES; NUCLEATION; ADSORPTION; EXCHANGE; AG(111); AG AB Field ion microscope observations show that the rate of surface self-diffusion for individual atoms on the (100) and (311) planes of Rh is significantly increased by exposure of the surface to hydrogen. On Rh(100) admission of hydrogen at partial pressures in the 10(-9)-Torr range causes the onset temperature for migration of a Rh adatom to decrease from 290 to 240 K. Once the adatom is mobile, its mean-square displacement is constant as a function of time. Similar exposures of hydrogen lower the onset temperature for self-diffusion on Rh(311) from 180 to 120 K. Here the mean-square displacement increases monotonically as a function of time after admission of hydrogen. The continuous increase indicates that the enhancement of the diffusion rate due to hydrogen is coverage dependent. The difference between the results for Rh(100) and Rh(311) is attributed to the higher temperatures required for self-diffusion on Rh(100). At the higher temperatures, a significant amount of hydrogen is thermally desorbed during the diffusion intervals and the coverage remains relatively constant as a function of time. The observed coverage dependence indicates that the mechanism of hydrogen promotion involves more than a simple lowering of the activation barrier of surface diffusion by the attachment of a hydrogen atom to a Rh atom. RP Kellogg, GL (reprint author), SANDIA NATL LABS,POB 5800,ALBUQUERQUE,NM 87185, USA. NR 29 TC 23 Z9 23 U1 2 U2 3 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 MAR 15 PY 1997 VL 55 IS 11 BP 7206 EP 7212 DI 10.1103/PhysRevB.55.7206 PG 7 WC Physics, Condensed Matter SC Physics GA WQ095 UT WOS:A1997WQ09500085 ER PT J AU Baker, SM Smith, GS Brown, NJS Nastasi, M Hubbard, K AF Baker, SM Smith, GS Brown, NJS Nastasi, M Hubbard, K TI Observation of nonstandard Fickian diffusion at the interface of isotopically pure amorphous B-11 on B-10 by neutron reflectometry SO PHYSICAL REVIEW B LA English DT Article ID BORON-DIFFUSION; SILICON AB As part of a larger study to investigate atomic-diffusion behavior in both elemental boron and refractory transition-metal borides, neutron reflectometry was used to examine the temperature-induced self-diffusion of isotopically enriched thin films of amorphous B-11 on B-10 deposited by electron-beam evaporation. The reflectometry studies were performed and model boron density profiles for samples annealed at various times and temperatures of 360 and 400 degrees C were fit to the reflectivity data. Although the B-10/B-11 interface did not move relative to the air/boron interface upon annealing, the expected standard Fickian diffusion for the annealed samples was not observed. A pinned Fickian diffusion model, which imposes the boundary conditions of a fixed composition of B-10 to B-11 at the interface, fit the reflectivity data accurately and consistently. A typical equilibrium diffusion constant was determined to be similar to 10(-17) cm(2) s(-1), measured at an annealing temperature of 360 degrees C. The measured diffusion constants are inconsistent with the high melting temperature of elemental boron, but are consistent with measured boron diffusion constants in other amorphous thin films. The presence of clusters in the boron film is proposed to explain the observed results. C1 LOS ALAMOS NATL LAB,LOS ALAMOS NEUTRON SCATTERING CTR H805,LOS ALAMOS,NM 87545. NR 22 TC 12 Z9 12 U1 0 U2 2 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 MAR 15 PY 1997 VL 55 IS 11 BP 7255 EP 7263 DI 10.1103/PhysRevB.55.7255 PG 9 WC Physics, Condensed Matter SC Physics GA WQ095 UT WOS:A1997WQ09500092 ER PT J AU Zhang, SW Carlson, J Gubernatis, JE AF Zhang, SW Carlson, J Gubernatis, JE TI Constrained path Monte Carlo method for fermion ground states SO PHYSICAL REVIEW B LA English DT Article ID 2-DIMENSIONAL HUBBARD-MODEL; QUANTUM RENORMALIZATION-GROUPS; MANY-ELECTRON SYSTEMS; NUMERICAL-SIMULATION; LATTICE FERMIONS; GREEN-FUNCTION; RANDOM-WALK; ALGORITHMS; MOLECULES; HELIUM AB We describe and discuss a recently proposed quantum Monte Carlo algorithm to compute the ground-state properties of various systems of interacting fermions. In this method, the ground state is projected fi om an initial wave function by a branching random walk in an overcomplete basis of Slater determinants. By constraining the determinants according to a trial wave function \psi(T)], we remove the exponential decay of signal-to-noise ratio characteristic of the sign problem. The method is variational and is exact if \psi(T)] is exact. We illustrate the method by describing in detail its implementation for the two-dimensional one-hand Hubbard model. We show results for lattice sizes up to 16x16 and for various electron fillings and interaction strengths. With simple single-determinant wave functions as \psi(T)], the method yields accurate (often to within a few percent) estimates of the ground-state energy as well as correlation functions, such as those for electron pairing. We conclude by discussing possible extensions of the algorithm. C1 LOS ALAMOS NATL LAB,DIV THEORET,LOS ALAMOS,NM 87545. LOS ALAMOS NATL LAB,CTR NONLINEAR STUDIES,LOS ALAMOS,NM 87545. OHIO STATE UNIV,DEPT PHYS,COLUMBUS,OH 43210. NR 43 TC 159 Z9 159 U1 1 U2 5 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 MAR 15 PY 1997 VL 55 IS 12 BP 7464 EP 7477 DI 10.1103/PhysRevB.55.7464 PG 14 WC Physics, Condensed Matter SC Physics GA WQ434 UT WOS:A1997WQ43400038 ER PT J AU Faulkner, JS Wang, Y Stocks, GM AF Faulkner, JS Wang, Y Stocks, GM TI Coulomb energies in alloys SO PHYSICAL REVIEW B LA English DT Article ID SHORT-RANGE ORDER; ELECTRONIC-STRUCTURE; MADELUNG LATTICE; BAND-STRUCTURE; RESISTIVITY; DENSITIES; NIOBIUM; STATES AB With the help of order-N calculations on realistic models of random substitutional alloys, we have studied the concentration, structure, and composition dependence of the part of the total energy that is stored in the interatomic Coulomb interaction. An observation about the relation between the self-consistent charges associated with a site and the long-range electrostatic potential at the site is used in the analysis. C1 FLORIDA ATLANTIC UNIV,DEPT PHYS,BOCA RATON,FL 33431. OAK RIDGE NATL LAB,DIV MET & CERAM,OAK RIDGE,TN 37830. RP Faulkner, JS (reprint author), FLORIDA ATLANTIC UNIV,ALLOY RES CTR,BOCA RATON,FL 33431, USA. RI Stocks, George Malcollm/Q-1251-2016 OI Stocks, George Malcollm/0000-0002-9013-260X NR 56 TC 36 Z9 36 U1 0 U2 3 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 MAR 15 PY 1997 VL 55 IS 12 BP 7492 EP 7507 DI 10.1103/PhysRevB.55.7492 PG 16 WC Physics, Condensed Matter SC Physics GA WQ434 UT WOS:A1997WQ43400040 ER PT J AU Cooley, JC Aronson, MC Canfield, PC AF Cooley, JC Aronson, MC Canfield, PC TI High pressures and the Kondo gap in Ce3Bi4Pt3 SO PHYSICAL REVIEW B LA English DT Article ID METAL-INSULATOR-TRANSITION; ANDERSON MODEL; BETHE-ANSATZ; HYBRIDIZATION GAP; MAGNETIC IMPURITY; 1/N EXPANSION; SUPERCONDUCTORS; SEMICONDUCTOR; DEPENDENCE; DEGENERACY AB We have measured the electrical resistivity p(T) of single crystals of Ce-3Bi4Pt3 for temperatures from 1.2 to 300 K, and pressures from I bar to 145 kbar. The transport is dominated at high temperatures by excitations across a small activation gap a, which increases rapidly with pressure. The low-temperature transport involves variable range hopping among extrinsic states in the gap. The spatial extent of the in-gap states reflects coupling to conduction-electron states, and is strongly modified as pressure enhances Delta. Despite the strong pressure dependence of Delta, a direct correspondence between single-ion energetics and the measured gap is maintained, and the role of valence fluctuations is minimal even at the highest pressures. C1 IOWA STATE UNIV SCI & TECHNOL, AMES LAB, AMES, IA 50011 USA. RP UNIV MICHIGAN, DEPT PHYS, ANN ARBOR, MI 48109 USA. RI Cooley, Jason/E-4163-2013; Canfield, Paul/H-2698-2014 NR 31 TC 22 Z9 22 U1 1 U2 8 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 2469-9950 EI 2469-9969 J9 PHYS REV B JI Phys. Rev. B PD MAR 15 PY 1997 VL 55 IS 12 BP 7533 EP 7538 DI 10.1103/PhysRevB.55.7533 PG 6 WC Physics, Condensed Matter SC Physics GA WQ434 UT WOS:A1997WQ43400044 ER PT J AU Espinosa, FJ deLeon, JM ZapataTorres, M CastroRodriguez, R Pena, JL Conradson, SD Hess, NJ AF Espinosa, FJ deLeon, JM ZapataTorres, M CastroRodriguez, R Pena, JL Conradson, SD Hess, NJ TI Direct observation of a lattice instability in heavily in-doped CdTe SO PHYSICAL REVIEW B LA English DT Article ID MOLECULAR-BEAM EPITAXY; DX-CENTERS; SEMICONDUCTORS; RELAXATION; IMPURITIES; LAYERS AB The nearest-neighbor environment around Cd atoms in CdTe and CdTe doped with 5 and 8 at. % indium was determined from Cd K-edge x-ray-absorption fine-structure measurements. The first shell of neighbors is split into two distances R(1) = 2.58 +/- 0.02 Angstrom, and R(2) = 2.81 +/- 0.01 Angstrom, for the doped samples. The presence of the short distance R(1) = 2.58 Angstrom is related to the existence of lattice relaxations produced by the introduction of indium. C1 LOS ALAMOS NATL LAB, LOS ALAMOS, NM 87545 USA. PACIFIC NW LAB, RICHMOND, WA 99352 USA. RP Espinosa, FJ (reprint author), INST POLITECN NACL, CTR INVEST & ESTUDIOS AVANZADOS, MERIDA 97310, YUCATAN, MEXICO. OI Hess, Nancy/0000-0002-8930-9500 NR 23 TC 11 Z9 11 U1 1 U2 3 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 MAR 15 PY 1997 VL 55 IS 12 BP 7629 EP 7632 DI 10.1103/PhysRevB.55.7629 PG 4 WC Physics, Condensed Matter SC Physics GA WQ434 UT WOS:A1997WQ43400057 ER PT J AU Lucas, CA Markovic, NM Ross, PN AF Lucas, CA Markovic, NM Ross, PN TI Adsorption of halide anions at the Pt(111)-solution interface studied by in situ surface x-ray scattering SO PHYSICAL REVIEW B LA English DT Article ID SCANNING-TUNNELING-MICROSCOPY; REGISTERED PHASE-TRANSITION; UNDERPOTENTIAL DEPOSITION; ELECTROLYTE INTERFACE; COMMENSURATE PHASES; DEVILS STAIRCASE; PT(111); IODINE; MONOLAYERS; CHLORIDE AB In this paper we present x-ray scattering results of iodide, bromide, and chloride adsorption onto the Pt(lll) surface in solution. Iodide forms two commensurate adlayer structures, a (root 7x root 7)R19.1 degrees phase and a hexagonal (3x3) phase, which coexist on the Pt surface. Formation of the (3x3) phase appears to be kinetically limited, whereas the root 7 phase shows a hysteretic effect as a function of the electrode potential, associated with an order-disorder transition. Bromide forms a series of high-order commensurate structures on Pt(lll) that are poorly ordered unless the size of the unit cell is small. No ordered structures for chloride adsorption are observed and specular x-ray reflectivity results suggest that the chloride coverage at low potential is too small to form a close-packed monolayer on the surface. The differences between the structures formed by the adsorbed anions, and the differences between results for Pt(111) and Au(111), are discussed in terms of the strength of the metal-halide interaction. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV MAT SCI,BERKELEY,CA 94720. OI Lucas, Christopher/0000-0001-5743-3868 NR 40 TC 71 Z9 71 U1 2 U2 16 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 MAR 15 PY 1997 VL 55 IS 12 BP 7964 EP 7971 DI 10.1103/PhysRevB.55.7964 PG 8 WC Physics, Condensed Matter SC Physics GA WQ434 UT WOS:A1997WQ43400095 ER PT J AU Hamilton, JC AF Hamilton, JC TI Dislocation nucleation rates during submonolayer growth of heteroepitaxial thin films SO PHYSICAL REVIEW B LA English DT Article ID RECONSTRUCTION; AU(111) AB Dislocation nucleation rates during submonolayer heteroepitaxial island growth an calculated using a two-dimensional Frenkel-Kontorova (FK) model combined with transition-state theory. A method for determining effective FK adatom pair potentials is tested using embedded atom method (EAM) potentials. Calculated prefactors and activation energies for dislocation nucleation are in excellent agreement with values from a full EAM molecular-dynamics simulation demonstrating the validity of this approach. RP Hamilton, JC (reprint author), SANDIA NATL LABS,LIVERMORE,CA 94550, USA. NR 17 TC 11 Z9 11 U1 0 U2 1 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 MAR 15 PY 1997 VL 55 IS 12 BP R7402 EP R7405 PG 4 WC Physics, Condensed Matter SC Physics GA WQ434 UT WOS:A1997WQ43400029 ER PT J AU Knupfer, M Neudert, R Kielwein, M Haffner, S Golden, MS Fink, J Kim, C Shen, ZX Merz, M Nucker, N Schuppler, S Motoyama, N Eisaki, H Uchida, S Hu, Z Domke, M Kaindl, G AF Knupfer, M Neudert, R Kielwein, M Haffner, S Golden, MS Fink, J Kim, C Shen, ZX Merz, M Nucker, N Schuppler, S Motoyama, N Eisaki, H Uchida, S Hu, Z Domke, M Kaindl, G TI Site-specific unoccupied electronic structure of one-dimensional SrCuO2 SO PHYSICAL REVIEW B LA English DT Article ID X-RAY-ABSORPTION; SPECTROSCOPY AB The unoccupied electronic structure of SrCuO2 single crystals has been studied using x-ray-absorption spectroscopy. By choosing the orientation of the single crystals with respect to the polarization vector of the synchrotron radiation, we are able to determine the hole occupation of the different O 2p and Cu 3d orbitals. We show that the intrinsic holes in the one-dimensional copper oxide zigzag chains mainly occupy planar Cu 3d(y2-z2) orbitals, which closely resembles the situation in the undoped parent compounds of the high-temperature superconductors. Additionally, most of the oxygen states that are admired to the upper Hubbard band are concentrated in the center of the chains most probably as a result of the larger number of nearest neighbors. Our results provide an important check for calculations of one-dimensional correlated Cu-O systems. C1 STANFORD UNIV,DEPT APPL PHYS,STANFORD,CA 94305. STANFORD UNIV,STANFORD SYNCHROTRON RADIAT LAB,STANFORD,CA 94305. FORSCHUNGSZENTRUM KARLSRUHE,INST NUKL FESTKORPERPHYS,D-76021 KARLSRUHE,GERMANY. UNIV TOKYO,DEPT SUPERCONDUCT,BUNKYO KU,TOKYO 113,JAPAN. FREE UNIV BERLIN,INST EXPT PHYS,D-14195 BERLIN,GERMANY. RP Knupfer, M (reprint author), INST FESTKORPERFORSCH & WERKSTOFFORSCH DRESDEN,D-01171 DRESDEN,GERMANY. RI Hu, Zhiwei/B-8635-2008; Fink, Joerg/A-6003-2012; Golden, Mark/D-3469-2011 NR 17 TC 13 Z9 13 U1 0 U2 1 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 MAR 15 PY 1997 VL 55 IS 12 BP R7291 EP R7294 PG 4 WC Physics, Condensed Matter SC Physics GA WQ434 UT WOS:A1997WQ43400001 ER PT J AU Kolb, EW Riotto, A AF Kolb, EW Riotto, A TI Particle production and symmetry restoration in collisions of vacuum bubbles SO PHYSICAL REVIEW D LA English DT Article ID EXTENDED INFLATION; EARLY UNIVERSE; BARYOGENESIS; EQUILIBRIUM; BOSONS AB In first-order inflation a phase transition is completed by the collisions of expanding true-vacuum bubbles. If bubble collisions produce large numbers of soft scalar particles carrying quantum numbers associated with a spontaneously broken symmetry, then symmetry restoration may occur in a ''preheating'' phase in a manner similar to symmetry restoration in the preheating phase of slow-roll inflation. Since bubble collisions lead to inhomogeneities, there is the possibility of inhomogeneous symmetry restoration where restoration occurs only in the regions of wall collisions. C1 UNIV CHICAGO,ENRICO FERMI INST,DEPT ASTRON & ASTROPHYS,CHICAGO,IL 60637. RP Kolb, EW (reprint author), FERMILAB NATL ACCELERATOR LAB,NASA,FERMILAB ASTROPHYS CTR,BATAVIA,IL 60510, USA. NR 34 TC 16 Z9 16 U1 0 U2 1 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2821 J9 PHYS REV D JI Phys. Rev. D PD MAR 15 PY 1997 VL 55 IS 6 BP 3313 EP 3317 DI 10.1103/PhysRevD.55.3313 PG 5 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA WQ102 UT WOS:A1997WQ10200010 ER PT J AU Copi, CJ Schramm, DN Turner, MS AF Copi, CJ Schramm, DN Turner, MS TI Big-bang nucleosynthesis limit to the number of neutrino species SO PHYSICAL REVIEW D LA English DT Article ID NEAR-INFRARED SPECTROSCOPY; LOCAL INTERSTELLAR-MEDIUM; PRIMORDIAL NUCLEOSYNTHESIS; DEUTERIUM; ABUNDANCE; STARS; EVOLUTION; LITHIUM; CAPELLA; GALAXY AB Concern about the systematic uncertainty in the He-4 abundance as well as the chemical evolution of He-3 leads us to reexamine this important limit. It is shown that with conservative assumptions no more than the equivalent four massless neutrino species are allowed. Even with the most extreme estimates of the astrophysical uncertainties a meaningful limit still exists, less than five massless neutrino species, and illustrates the robustness of this argument. We show that a definitive measurement of the deuterium abundance in high-redshift hydrogen clouds can sharpen the limit. C1 FERMILAB NATL ACCELERATOR LAB,NASA,FERMILAB ASTROPHYS CTR,BATAVIA,IL 60510. UNIV CHICAGO,DEPT ASTRON & ASTROPHYS,CHICAGO,IL 60637. RP Copi, CJ (reprint author), UNIV CHICAGO,ENRICO FERMI INST,DEPT PHYS,CHICAGO,IL 60637, USA. NR 49 TC 38 Z9 38 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2821 J9 PHYS REV D JI Phys. Rev. D PD MAR 15 PY 1997 VL 55 IS 6 BP 3389 EP 3393 DI 10.1103/PhysRevD.55.3389 PG 5 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA WQ102 UT WOS:A1997WQ10200017 ER PT J AU Carlini, A Greensite, J AF Carlini, A Greensite, J TI Mass shell of the universe SO PHYSICAL REVIEW D LA English DT Article ID 3RD QUANTIZATION; COSMOLOGICAL CONSTANT AB The classical field equations of general relativity can be expressed as a single geodesic equation, describing the free fall of a point particle in superspace. Based on this formulation, a ''world line'' quantization of gravity, analogous to the Feynman-Schwinger treatment of particle propagation, is proposed, and a hidden mass-shell parameter is identified. We consider the effective action for the supermetric, which would be induced at one loop. In certain minisuperspace models, we find that this effective action is stationary for a vanishing cosmological constant. We also note that an interacting ''particle'' in superspace would propagate somewhat off shell, and suggest that a small deviation from the mass shell might be detectable (at least in principle) as a new source of decoherence. C1 UNIV CALIF BERKELEY,ERNEST ORLANDO LAWRENCE BERKELEY NATL LAB,THEORET PHYS GRP,BERKELEY,CA 94720. SAN FRANCISCO STATE UNIV,DEPT PHYS & ASTRON,SAN FRANCISCO,CA 94132. RP Carlini, A (reprint author), TOKYO INST TECHNOL,MEGURO KU,TOKYO 152,JAPAN. RI Carlini, Alberto/A-9353-2011 NR 17 TC 6 Z9 6 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2821 J9 PHYS REV D JI Phys. Rev. D PD MAR 15 PY 1997 VL 55 IS 6 BP 3514 EP 3524 DI 10.1103/PhysRevD.55.3514 PG 11 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA WQ102 UT WOS:A1997WQ10200030 ER PT J AU Kallosh, R Rajaraman, A Wong, WK AF Kallosh, R Rajaraman, A Wong, WK TI Supersymmetric rotating black holes and attractors SO PHYSICAL REVIEW D LA English DT Article ID MAXWELL-EINSTEIN SUPERGRAVITY; JORDAN ALGEBRAS; EQUATIONS; GEOMETRY; FIELDS AB Five-dimensional stringy rotating black holes are embedded into N=2 supergravity interacting with one vector multiplet. The existence of an unbroken supersymmetry of the rotating solution is proved directly by solving the Killing spinor equations. The asymptotic enhancement of supersymmetry near the horizon in the presence of rotation is established via the calculation of the supercurvature. The area of the horizon of the rotating supersymmetric black holes is found to be root Z(fix)(3)-J(2), where Z(fix) is the extremal value of the central charge in moduli space. C1 STANFORD UNIV,STANFORD LINEAR ACCELERATOR CTR,STANFORD,CA 94309. RP Kallosh, R (reprint author), STANFORD UNIV,DEPT PHYS,STANFORD,CA 94305, USA. NR 19 TC 41 Z9 41 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2821 J9 PHYS REV D JI Phys. Rev. D PD MAR 15 PY 1997 VL 55 IS 6 BP R3246 EP R3249 PG 4 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA WQ102 UT WOS:A1997WQ10200002 ER PT J AU Sriram, M Osipiuk, J Freeman, BC Morimoto, RI Joachimiak, A AF Sriram, M Osipiuk, J Freeman, BC Morimoto, RI Joachimiak, A TI Human Hsp70 molecular chaperone binds two calcium ions within the ATPase domain SO STRUCTURE LA English DT Article DE ATPase; calcium-binding motif; Hsp70; molecular chaperone ID SHOCK COGNATE PROTEIN; GLUCOSE-REGULATED PROTEIN; ESCHERICHIA-COLI; DNAK CHAPERONE; ACTIVE-SITE; 3-DIMENSIONAL STRUCTURE; SUBSTRATE-BINDING; GENE; AUTOPHOSPHORYLATION; EXPRESSION AB Background: The 70 kDa heat shock proteins (Hsp70) are a family of molecular chaperones, which promote protein folding and participate in many cellular functions. The Hsp70 chaperones are composed of two major domains. The N-terminal ATPase domain binds to and hydrolyzes ATP, whereas the C-terminal domain is required for polypeptide binding. Cooperation of both domains is needed for protein folding, The crystal structure of bovine Hsc70 ATPase domain (bATPase) has been determined and, more recently, the crystal structure of the peptide-binding domain of a related chaperone, DnaK, in complex with peptide substrate has been obtained. The molecular chaperone activity and conformational switch are functionally linked with ATP hydrolysis. A high-resolution structure of the ATPase domain is required to provide an understanding of the mechanism of ATP hydrolysis and how it affects communication between C- and N-terminal domains. Results: The crystal structure of the human Hsp70 ATPase domain (hATPase) has been determined and refined at 1.84 Angstrom, using synchrotron radiation at 120K. Two calcium sites were identified: the first calcium binds within the catalytic pocket, bridging ADP and inorganic phosphate, and the second calcium is tightly coordinated on the protein surface by Glu231, Asp232 and the carbonyl of His227, Overall, the structure of hATPase is similar to bATPase. Differences between them are found in the loops, the sites of amino acid substitution and the calcium-binding sites. Human Hsp70 chaperone is phosphorylated in vitro in the presence of divalent ions, calcium being the most effective. Conclusions: The structural similarity of hATPase and bATPase and the sequence similarity within the Hsp70 chaperone family suggest a universal mechanism of ATP hydrolysis among all Hsp70 molecular chaperones. Two calcium ions have been found in the hATPase structure. One corresponds to the magnesium site in bATPase and appears to be important for ATP hydrolysis and in vitro phosphorylation, Local changes in protein structure as a result of calcium binding may facilitate phosphorylation, A small, but significant, movement of metal ions and sidechains could position catalytically important threonine residues for phosphorylation. The second calcium site represents a new calcium-binding motif that can play a role in the stabilization of protein structure. We discuss how the information about catalytic events in the active site could be transmitted to the peptide-binding domain. C1 NORTHWESTERN UNIV,DEPT BIOCHEM MOL BIOL & CELL BIOL,EVANSTON,IL 60208. RP Sriram, M (reprint author), ARGONNE NATL LAB,9700 S CASS AVE,ARGONNE,IL 60439, USA. NR 51 TC 85 Z9 89 U1 0 U2 1 PU CURRENT BIOLOGY LTD PI LONDON PA 34-42 CLEVELAND STREET, LONDON, ENGLAND W1P 6LB SN 0969-2126 J9 STRUCTURE JI Structure PD MAR 15 PY 1997 VL 5 IS 3 BP 403 EP 414 DI 10.1016/S0969-2126(97)00197-4 PG 12 WC Biochemistry & Molecular Biology; Biophysics; Cell Biology SC Biochemistry & Molecular Biology; Biophysics; Cell Biology GA WR389 UT WOS:A1997WR38900010 PM 9083109 ER PT J AU Marathe, MV Radhakrishnan, V Hunt, HB Ravi, SS AF Marathe, MV Radhakrishnan, V Hunt, HB Ravi, SS TI Hierarchically specified unit disk graphs SO THEORETICAL COMPUTER SCIENCE LA English DT Article; Proceedings Paper CT Proceedings of the 19th International Workshop on Graph Theoretic Concepts in Computer Science (WG 93) CY 1993 CL UTRECHT, NETHERLANDS ID DEFINED GRAPHS; ALGORITHMS; HARDNESS; PACKING AB We characterize the complexity of a number of basic optimization problems for unit disk graphs specified hierarchically as in [2, 17, 19, 20]. Both PSPACE-hardness results and polynomial time approximations are presented for most of the problems considered. These problems include minimum vertex coloring, maximum independent set, minimum clique cover, minimum dominating set and minimum independent dominating set. Each of our PSPACE-hardness results holds, when the hierarchical specifications are 1-level restricted and the graphs are specified hierarchically either as in [2] or as in [19]. The hardness results presented here significantly extend the hardness results in [2, 19]. The approximation algorithms presented here along with our results in [24, 25] are among the first polynomial time approximation algorithms for natural PSPACE-hard functions. C1 HEWLETT PACKARD CORP, CUPERTINO, CA 95014 USA. SUNY ALBANY, DEPT COMP SCI, ALBANY, NY 12222 USA. RP Marathe, MV (reprint author), LOS ALAMOS NATL LAB, POB 1663, MS K990, LOS ALAMOS, NM 87545 USA. NR 35 TC 9 Z9 9 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0304-3975 J9 THEOR COMPUT SCI JI Theor. Comput. Sci. PD MAR 15 PY 1997 VL 174 IS 1-2 BP 23 EP 65 DI 10.1016/S0304-3975(96)00008-4 PG 43 WC Computer Science, Theory & Methods SC Computer Science GA WN083 UT WOS:A1997WN08300002 ER PT J AU Kleinke, H Franzen, HF AF Kleinke, H Franzen, HF TI Hf2NiP: The planned modification of an intermetallic phase by (formal) substitution of nickel by phosphorus SO ANGEWANDTE CHEMIE-INTERNATIONAL EDITION IN ENGLISH LA English DT Article DE amino acids; magnesium; nucleobases; solid-state structures; supramolecular chemistry ID CHEMISTRY; FE2TA9S6; CO2TA9S6; CLUSTERS C1 IOWA STATE UNIV,DOE,AMES LAB,AMES,IA 50011. NR 23 TC 14 Z9 14 U1 0 U2 1 PU WILEY-V C H VERLAG GMBH PI WEINHEIM PA POSTFACH 10 11 61, D-69451 WEINHEIM, GERMANY SN 0570-0833 J9 ANGEW CHEM INT EDIT JI Angew. Chem.-Int. Edit. Engl. PD MAR 14 PY 1997 VL 36 IS 5 BP 513 EP 516 DI 10.1002/anie.199705131 PG 4 WC Chemistry, Multidisciplinary SC Chemistry GA WV556 UT WOS:A1997WV55600017 ER PT J AU Chambers, SA Thevuthasan, S Kim, YJ Herman, GS Wang, Z Tober, E Ynzunza, R Morais, J Peden, CHF Ferris, K Fadley, CS AF Chambers, SA Thevuthasan, S Kim, YJ Herman, GS Wang, Z Tober, E Ynzunza, R Morais, J Peden, CHF Ferris, K Fadley, CS TI Chemisorption geometry of formate on TiO2(110) by photoelectron diffraction SO CHEMICAL PHYSICS LETTERS LA English DT Article ID FORMIC-ACID DECOMPOSITION; SURFACE AB We have combined photoelectron diffraction in both scanned-angle and scanned-energy modes with Hartree-Fock calculations to investigate the interface structure of HCOO- on TiO2(110). Formate anions bind through the oxygens to Ti cation rows along [001] with a 2 X periodicity and an O-C-O bond angle of 126 +/- 4 degrees. Each anion binds to two Ti cations with an adsorbate-substrate bond distance of 2.0 +/- 0.1 Angstrom. C1 LAWRENCE BERKELEY NATL LAB, BERKELEY, CA 94720 USA. UNIV CALIF DAVIS, DEPT PHYS, DAVIS, CA 95616 USA. RP Chambers, SA (reprint author), PACIFIC NW NATL LAB, POB 999, RICHLAND, WA 99352 USA. RI Morais, Jonder/E-5022-2013; OI Morais, Jonder/0000-0002-4143-1208; Peden, Charles/0000-0001-6754-9928 NR 18 TC 73 Z9 73 U1 1 U2 9 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0009-2614 J9 CHEM PHYS LETT JI Chem. Phys. Lett. PD MAR 14 PY 1997 VL 267 IS 1-2 BP 51 EP 57 DI 10.1016/S0009-2614(97)00070-5 PG 7 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA WM948 UT WOS:A1997WM94800008 ER PT J AU Hrbek, J Li, SY Rodriguez, JA vanCampen, DG Huang, HH Xu, GQ AF Hrbek, J Li, SY Rodriguez, JA vanCampen, DG Huang, HH Xu, GQ TI Synthesis of sulfur films from S-2 gas: Spectroscopic evidence for the formation of S-n species SO CHEMICAL PHYSICS LETTERS LA English DT Article ID PHASE-DIAGRAM; ADSORPTION; RU(001); MO(110); METALS AB Thin films of molecular sulfur were prepared by the deposition of S-2 gas from an electrochemical doser on single crystal metal surfaces kept at temperatures below 250 K. These films were characterized by XPS, UPS, TDS and IRAS, and were found to be stable up to 390 K even under UHV conditions. Cyclooctasulfur S-8 was identified as one of the sulfur molecules present. C1 BROOKHAVEN NATL LAB,NATL SYNCHROTRON LIGHT SOURCE DEPT,UPTON,NY 11973. NATL UNIV SINGAPORE,DEPT CHEM,SINGAPORE 119260,SINGAPORE. RP Hrbek, J (reprint author), BROOKHAVEN NATL LAB,DEPT CHEM,UPTON,NY 11973, USA. RI Xu, Guo Qin/C-2077-2013; Hrbek, Jan/I-1020-2013 NR 32 TC 30 Z9 30 U1 1 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0009-2614 J9 CHEM PHYS LETT JI Chem. Phys. Lett. PD MAR 14 PY 1997 VL 267 IS 1-2 BP 65 EP 71 DI 10.1016/S0009-2614(97)00069-9 PG 7 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA WM948 UT WOS:A1997WM94800010 ER PT J AU Valley, JW Eiler, JM Graham, CM Gibson, EK Romanek, CS Stolper, EM AF Valley, JW Eiler, JM Graham, CM Gibson, EK Romanek, CS Stolper, EM TI Low-temperature carbonate concretions in the Martian meteorite ALH84001: Evidence from stable isotopes and mineralogy SO SCIENCE LA English DT Article ID MARS VOLATILE EVOLUTION; SNC METEORITES; SYSTEM CACO3-MGCO3-FECO3; OXYGEN; CALCITE; WATER; FRACTIONATION; QUARTZ; MODEL; THERMOMETRY AB The martian meteorite ALH84001 contains small, disk-shaped concretions of carbonate with concentric chemical and mineralogical zonation. Oxygen isotope compositions of these concretions, measured by ion microprobe, range from delta(18)O = +9.5 to +20.5 parts per thousand, Most of the core of one concretion is homogeneous (16.7 +/- 1.2 parts per thousand) and over 5 parts per thousand higher in delta(18)O than a second concretion. Orthopyroxene that hosts the secondary carbonates is isotopically homogeneous (delta(18)O = 4.6 +/- 1.2 parts per thousand). Secondary SiO2 has delta(18)O = 20.4 parts per thousand. Carbon isotope ratios measured from the core of one concretion average delta(13)C = 46 +/- 8 parts per thousand, consistent with formation on Mars. The isotopic variations and mineral compositions offer no evidence for high temperature (>650 degrees C) carbonate precipitation and suggest non-equilibrium processes at low temperatures (10 mN/m), the film is closely packed with practically untilted hydrocarbon chains and hydrated phosphate headgroups. On solutions containing either water-soluble cationic tetraazaphthalocyanines or tetrapyridylporphyrins, significant changes in the organization of the lipid with respect to that on pure water are found. Total film thicknesses are larger and consistent with the adsorption of a single pigment layer contiguous to the headgroup, whereas the hydrocarbon tail region is shorter, suggestive of tilted alkyl chains. In addition, film thicknesses for phthalocyanine-containing films suggest formation of an iodide counterion layer underneath the plane containing the pigments. This sharply contrasts the interfacial profile obtained for porphyrin-containing films, in which the iodide counterions appear to exist within the pigment plane. Visible absorption spectra of all transferred films indicate a closely packed single pigment layer, consistent with the reflectivity results. The optical spectra of the pigment are preserved (in relation to the aqueous solution monomer spectra) in the transferred film, indicating a suppression of pigment aggregation. Reflectivity measurements at large molecular areas on pure water indicate that DHDP forms an inhomogeneous film, suggestive of phase segregation; on the pigment-containing solutions, DHDP induces (through attractive Coulomb interactions) the adsorption of a homogeneous monopigment layer. The existence of a complete pigment monolayer over the measured surface pressure-molecular area (pi-A) isotherms has been evidenced by both X-ray reflectivity and visible optical studies. Preservation of pigment functionality has been demonstrated through the process of Coulomb association of the chromophores with charged lipid monolayer headgroups at the air/water interface. The potential for applications as model photosynthetic antennae will be discussed. C1 US DOE,AMES LAB,AMES,IA 50011. IOWA STATE UNIV,DEPT CHEM,AMES,IA 50011. IOWA STATE UNIV,DEPT PHYS & ASTRON,AMES,IA 50011. BROOKHAVEN NATL LAB,DEPT PHYS,UPTON,NY 11973. UNIV CALIF DAVIS,DEPT CHEM ENGN,DAVIS,CA 95616. RI Vaknin, David/B-3302-2009 OI Vaknin, David/0000-0002-0899-9248 NR 61 TC 42 Z9 42 U1 1 U2 8 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 1089-5647 J9 J PHYS CHEM B JI J. Phys. Chem. B PD MAR 13 PY 1997 VL 101 IS 11 BP 2006 EP 2019 DI 10.1021/jp963152i PG 14 WC Chemistry, Physical SC Chemistry GA WM886 UT WOS:A1997WM88600012 ER PT J AU Grossman, Y Worah, MP AF Grossman, Y Worah, MP TI CP asymmetries in B decays with new physics in decay amplitudes SO PHYSICS LETTERS B LA English DT Article ID STANDARD MODEL; VIOLATION; EXTRACTION; BREAKING AB We make a systematic analysis of the effects of new physics in the B decay amplitudes on the CP asymmetries in neutral B decays. Although these are expected to be smaller than new physics effects on the mixing amplitude, they are easier to probe in some cases. The effects of new contributions to the mixing amplitude are felt universally across all decay modes, whereas the effects of new decay amplitudes could vary from mode to mode. In particular the prediction that the CP asymmetries in the B-d decay modes with b --> c(c) over bars$, b --> c(c) over bard$, b --> c(u) over bard$ and b --> s(s) over bars$ should all measure the same quantity (sin 2 beta in the Standard Model) could be violated. Since the above Standard Model prediction is very precise, new decay amplitudes which are a few percent of the Standard Model amplitudes can be probed. Three examples of models where measurable effects are allowed are given: effective supersymmetry, models with enhanced chromomagnetic dipole operators, and supersymmetry without R parity. (C) 1997 Published by Elsevier Science B.V. RP Grossman, Y (reprint author), STANFORD UNIV,STANFORD LINEAR ACCELERATOR CTR,STANFORD,CA 94309, USA. NR 37 TC 296 Z9 296 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0370-2693 J9 PHYS LETT B JI Phys. Lett. B PD MAR 13 PY 1997 VL 395 IS 3-4 BP 241 EP 249 DI 10.1016/S0370-2693(97)00068-3 PG 9 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA WM738 UT WOS:A1997WM73800016 ER PT J AU Kao, C Atwood, D Soni, A AF Kao, C Atwood, D Soni, A TI Parity violation in bottom quark pair production at polarized hadron colliders SO PHYSICS LETTERS B LA English DT Article ID TOP-QUARK; COLLISIONS; FERMILAB AB Parity violation induced by the chromo-anapole form factor of the bottom quark, generated from weak corrections, is studied in polarized hadron collisions. The forward-backward asymmetry in the bottom quark pair production at polarized pp and p (p) over bar colliders is evaluated in the Standard Model and in a two Higgs doublet model to examine the effects of parity violation. In the models studied, promising results are found for polarized p (p) over bar colliders. (C) 1997 Published by Elsevier Science B.V. C1 UNIV WISCONSIN,DEPT PHYS,MADISON,WI 53706. CONTINUOUS ELECTRON BEAM ACCELERATOR FACIL CTR,THEORY GRP,NEWPORT NEWS,VA 23606. BROOKHAVEN NATL LAB,DEPT PHYS,UPTON,NY 11973. RP Kao, C (reprint author), UNIV ROCHESTER,DEPT PHYS & ASTRON,ROCHESTER,NY 14627, USA. NR 17 TC 4 Z9 4 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0370-2693 J9 PHYS LETT B JI Phys. Lett. B PD MAR 13 PY 1997 VL 395 IS 3-4 BP 327 EP 333 DI 10.1016/S0370-2693(97)00082-8 PG 7 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA WM738 UT WOS:A1997WM73800029 ER PT J AU Azimov, Y Dunietz, I AF Azimov, Y Dunietz, I TI A way to measure very large Delta m for B-S mesons SO PHYSICS LETTERS B LA English DT Article ID DECAYS; VIOLATION AB While present vertex technology cannot measure x(s) much beyond 20, the Standard Model accommodates significantly larger x(s) values. This note presents a method to determine very large x, with present technology. The determination is based upon subtle coherence effects between initial B-s mesons and daughter neutral kaons, discovered by one of us several years ago. The method may be useful also for measuring very small width or mass differences in mixed neutral B or D mesons. (C) 1997 Published by Elsevier Science B.V. C1 PETERSBURG NUCL PHYS INST,ST PETERSBURG 118350,RUSSIA. RP Azimov, Y (reprint author), FERMILAB NATL ACCELERATOR LAB,POB 500,BATAVIA,IL 60510, USA. NR 18 TC 8 Z9 8 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0370-2693 J9 PHYS LETT B JI Phys. Lett. B PD MAR 13 PY 1997 VL 395 IS 3-4 BP 334 EP 338 DI 10.1016/S0370-2693(97)00065-8 PG 5 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA WM738 UT WOS:A1997WM73800030 ER PT J AU Buchalla, G AF Buchalla, G TI Renormalization of Delta B=2 transitions in the static limit beyond leading logarithms SO PHYSICS LETTERS B LA English DT Article ID 4-FERMION OPERATORS; HEAVY QUARKS; LIGHT; DECAYS AB The renormalization group evolution of Delta B = 2 transition operators is studied at leading order in heavy quark effective theory and at next-to-leading order in QCD. We calculate new contributions that were not taken into account in previous work and obtain the complete result to next-to-leading logarithmic accuracy. The various scheme and scale dependences and their cancellation in physical quantities are discussed explicitly. (C) 1997 Published by Elsevier Science B.V. RP Buchalla, G (reprint author), FERMILAB NATL ACCELERATOR LAB,DEPT THEORET PHYS,POB 500,BATAVIA,IL 60510, USA. NR 13 TC 16 Z9 16 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0370-2693 J9 PHYS LETT B JI Phys. Lett. B PD MAR 13 PY 1997 VL 395 IS 3-4 BP 364 EP 368 DI 10.1016/S0370-2693(97)00043-9 PG 5 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA WM738 UT WOS:A1997WM73800034 ER PT J AU Senge, MO Medforth, CJ Forsyth, TP Lee, DA Olmstead, MM Jentzen, W Pandey, RK Shelnutt, JA Smith, KM AF Senge, MO Medforth, CJ Forsyth, TP Lee, DA Olmstead, MM Jentzen, W Pandey, RK Shelnutt, JA Smith, KM TI Comparative analysis of the conformations of symmetrically and asymmetrically deca- and undecasubstituted porphyrins bearing meso-alkyl or -aryl groups SO INORGANIC CHEMISTRY LA English DT Review ID PHOTOSYNTHETIC REACTION CENTER; X-RAY STRUCTURE; NONPLANAR NICKEL(II) PORPHYRINS; PHOTOINDUCED ELECTRON-TRANSFER; HIGHLY SUBSTITUTED PORPHYRINS; LIGHT-ABSORPTION PROPERTIES; CRYSTAL-STRUCTURE; RHODOPSEUDOMONAS-VIRIDIS; MOLECULAR-STRUCTURE; RESONANCE RAMAN AB Conformational analysis of highly substituted porphyrins has potential implications for modeling the behavior of macrocycles in tetrapyrrole-containing protein complexes and during catalytic reactions. In order to study the influence of different substituent patterns on the conformation of the porphyrin macrocycle, a series of metal free and nickel(II) decasubstituted porphyrins bearing aryl or ethyl groups at opposite meso positions and alkyl groups at the pyrrole positions have been synthesized and characterized by X-ray crystallography. Crystal structures of the flee-base porphyrins with 5,15-diaryl substituents showed negligible out-of-plane distortion but a large amount of in-plane distortion along the 5,15-axis accompanied by large bond angle changes similar to those previously seen for related porphyrins with 5,15-dialkyl substituents. Nickel(II) complexes of the 5,15-diaryl-substituted porphyrins show planar or modestly nonplanar conformations, suggesting that these complexes are not intrinsically nonplanar, whereas a complex with 5,15-diethyl substituents has a very ruffled conformation similar to those observed for related complexes with other metals. The nickel(II) complexes are also elongated along the 5,15-axis in a qualitatively similar but less dramatic fashion than are the free-base porphyrins. Spectrosopic studies (H-1 NMR, optical, and resonance Raman spectroscopy) suggest that conformations similar to those determined by X-ray crystallography are present in solution for the 5,15-dialkyl- and 5,15-diaryl-substituted porphyrins. Several asymmetric nickel(II) and metal-free deca- and undecasubstituted porphyrins containing both aryl and alkyl mesosubstituents were also investigated. Metal-free 5,15-disubstituted porphyrins with one aryl and one alkyl group showed considerably elongated porphyrin cores, whereas nickel(II) complexes of porphyrins with 5,10- or 5,10,15-substitution patterns showed very nonplanar structures consisting mainly of ruffle and saddle type distortions. C1 FREE UNIV BERLIN,INST ORGAN CHEM WE02,D-14195 BERLIN,GERMANY. SANDIA NATL LABS,FUEL SCI DEPT,ALBUQUERQUE,NM 87185. RP Senge, MO (reprint author), UNIV CALIF DAVIS,DEPT CHEM,DAVIS,CA 95616, USA. RI Shelnutt, John/A-9987-2009; Senge, Mathias/F-1504-2011; Medforth, Craig/D-8210-2013; REQUIMTE, FMN/M-5611-2013; REQUIMTE, UCIBIO/N-9846-2013; Smith, Kevin/G-1453-2011 OI Shelnutt, John/0000-0001-7368-582X; Senge, Mathias/0000-0002-7467-1654; Medforth, Craig/0000-0003-3046-4909; Smith, Kevin/0000-0002-6736-4779 NR 143 TC 91 Z9 91 U1 0 U2 4 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0020-1669 J9 INORG CHEM JI Inorg. Chem. PD MAR 12 PY 1997 VL 36 IS 6 BP 1149 EP 1163 DI 10.1021/ic961156w PG 15 WC Chemistry, Inorganic & Nuclear SC Chemistry GA WM811 UT WOS:A1997WM81100031 ER PT J AU Bigoli, F Deplano, P Devillanova, FA Ferraro, JR Lippolis, V Lukes, PJ Mercuri, ML Pellinghelli, MA Trogu, EF Williams, JM AF Bigoli, F Deplano, P Devillanova, FA Ferraro, JR Lippolis, V Lukes, PJ Mercuri, ML Pellinghelli, MA Trogu, EF Williams, JM TI Syntheses, x-ray crystal structures, and spectroscopic properties of new nickel dithiolenes and related compounds SO INORGANIC CHEMISTRY LA English DT Article ID NEAR-IR ABSORPTION; MOLECULAR-STRUCTURE; COMPLEXES; METAL; ET4TODIT; DMIT; 4,5,6,7-TETRATHIOCINO<1,2-B-3,4-B'>DIIMIDAZOLYL-1,3,8,10-TETRAETHYL-2,9- DITHION.; RAMAN AB The direct addition of nickel powder to the reaction mixtures of 1,3-dialkyl-4,5-dioxoimidazolidine-2-thione (1) with the thionation Lawesson reagent produces [Ni-II(R(2)timdt(-))(2)] (R(2)timdt = 1,3-dialkylmidazolidine-2,4,5-trithione). These complexes belong to a new class of nickel-dithiolenes, showing remarkably high absorption (epsilon approximate to 80000 dm(3) mol(-1) cm(-1), lambda approximate to 1000 nm) in the near-infrared region (near-IR), accompanied by high photochemical stability that makes these complexes promising near-IR dyes. In the absence of nickel the reaction yields generally the compounds 4,5,6,7-tetrathiocino[1,2-b:3,4-b']diimdazolyl-1,3,8,10-tetraalkane-2,9-dithione (2) instead of the expected 1,3-dialkylimidazolidine-2,4,5-trithione. However, with bulky substituents on the nitrogen atoms, well-characterized reaction products have not been obtained until now. Only in the R = Pr-i case, the new tetrathiocino isomer (4,5,9,10-tetrathiocino[1,2-b:5,6-b']diimidazolyl-1,3,6,8-tetraisopropane-2,7-dithione (3) in trace amounts and the bis(1,3-diisopropyl-2-thioxoimidazolin-4-yl) disulfide (4) were isolated from the reaction with the Lawesson reagent and P4S10, respectively. Reaction of 5 with different amounts of I-2 leads to a variety of products, and among them the following derivatives have been characterized: [Ni-II(Pr(2)(i)timdt(-))(2)]. 2I(2) (6) a neutral adduct in which each I-2 molecule interacts with each peripheral thione sulfur atom of 5; [Ni-II(Pr(2)(i)timdt(-))(2)]. 2I(2) . 1/2I(2) (7), which differs from 6 with the presence of half diiodine as a guest; with a larger diiodine excess (starting from a 1:10 molar ratio) a partial oxidation of 5 is achieved and [Ni-II(Pr(2)(i)timdt(-))(2)] [Ni-II(I)(2)(Pr(2)(i)timdt)(2)]. 5I(2) (8) is formed, a ligand mixed-valence compound in which the square-planar complex 5 and the octahedral complex [Ni-II(I)(2)(Pr(2-)(i)timdt)(2)] (the ligand in neutral form) are bound by diiodine molecules in such a way that a sequence of 12 iodine atoms (S . I-2 ... I-2 ... I-... I-2 ... I-... I-2 ... I-2 . S) is formed. Spectroscopic and X-ray diffractometric studies of 3 (monoclinic, space group P2(1)/n, a = 13.104(6) Angstrom, b = 15.091(6) Angstrom, c = 6.067(7) Angstrom, beta = 103.00(2)degrees, Z = 2), 4 (monoclinic, space group C2/c, a = 18.717(5) Angstrom, b = 8.846(5) Angstrom, c = 14.475(5) Angstrom, beta = 97.78(2)degrees, Z = 4), 5 (orthorhombic, space group Pna2(1), a = 18.806(5) Angstrom, b = 5.628(7) Angstrom, c = 23.665(5) Angstrom, Z = 4), 7 (triclinic, space group , a = 9.126(7) Angstrom, b = 9.153(7) Angstrom, c = 12.924(6) Angstrom, alpha = 82.11(2), beta = 70.14(2), gamma = 72.51(2)degrees, Z = 1), and 8 (monoclinic, space group C2/c, a = 21.971(6) Angstrom, b = 28.081(5) Angstrom, c = 12.207(8) Angstrom, beta = 93.57(2)degrees, Z = 4) are given. C1 UNIV CAGLIARI,DIPARTIMENTO CHIM & TECNOL INORGAN & MET ORGA,I-09124 CAGLIARI,ITALY. UNIV PARMA,CNR,CTR STUDIO STRUTTURIST DIFFRATTOMETR,I-43100 PARMA,ITALY. ARGONNE NATL LAB,DIV CHEM,ARGONNE,IL 60439. ARGONNE NATL LAB,DIV SCI MAT,ARGONNE,IL 60439. OI LIPPOLIS, VITO/0000-0001-8093-576X NR 32 TC 53 Z9 54 U1 0 U2 5 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0020-1669 J9 INORG CHEM JI Inorg. Chem. PD MAR 12 PY 1997 VL 36 IS 6 BP 1218 EP 1226 DI 10.1021/ic960930c PG 9 WC Chemistry, Inorganic & Nuclear SC Chemistry GA WM811 UT WOS:A1997WM81100038 ER PT J AU Zhang, HH Filipponi, A DiCicco, A Scott, MJ Holm, RH Hedman, B Hodgson, KO AF Zhang, HH Filipponi, A DiCicco, A Scott, MJ Holm, RH Hedman, B Hodgson, KO TI Multiple-edge XAS studies of cyanide-bridged iron-copper molecular assemblies relevant to cyanide-inhibited heme-copper oxidases using four-body multiple-scattering analysis SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Article ID CYTOCHROME-C-OXIDASE; ABSORPTION FINE-STRUCTURE; THERMUS-THERMOPHILUS; BINUCLEAR SITE; EXAFS ANALYSIS; CIRCULAR-DICHROISM; SPECTROSCOPY; COMPLEXES; ANALOG; ANGLE AB A pair of cyanide-bridged iron-copper molecular assemblies relevant to cyanide-inhibited heme-copper oxidases has been studied by X-ray absorption spectroscopy at both Fe and Cu K-edges. These two complexes, [(py>(OEP>Fe-CN-Cu(Me(6)tren)](2+) (2) and [(py)(OEP)Fe-CN-Cu(TIM)](2+) (3), contain a unique four-body Fe-C-N-Cu bridge with an Fe-C-N angle of 179 degrees. They, however, differ significantly in the Cu-N-C angle (174 degrees in 2 and 147 degrees in 3). These two complexes provide the opportunity to study long-range multiple scattering CMS) interactions between the Fe and the Cu centers. We have calculated theoretical four-body MS signals for the bridge configuration and other four-body pathways in the structures, and performed least-squares fittings of the theoretical signals to the experimental data using;the GNXAS programs. A strong long-range Fe Cu interaction (4.94 Angstrom) has been observed from both the Fe and Cu K-edge data for 2. GNXAS analysis shows that this long-range interaction is attributed to the MS amplitude enhancement from the linear four-body Fe-C-N-Cu configuration. This interaction is not observable from the Fe and Cu K-edge data for 3 where the angle deviates significantly from linearity. An angle-dependence study of MS effects on the Cu-N-C angle shows that there is a large enhancement of MS intensity when the angle approaches linearity, and that this MS effect is negligible when the angle is below similar to 160 degrees. Essentially no Fe-Cu interaction is detectable for a configuration with such an angle. Comparisons with three-body MS effects found in Fe-O/O(H)-Cu bridged systems are made. The significance of the findings of this study to the structural definition of the binuclear center in the cyanide-inhibited heme-copper oxidases is discussed. C1 HARVARD UNIV,DEPT CHEM,CAMBRIDGE,MA 02138. STANFORD UNIV,DEPT CHEM,STANFORD,CA 94305. EUROPEAN SYNCHROTRON RADIAT FACIL,F-38043 GRENOBLE,FRANCE. STANFORD UNIV,STANFORD SYNCHROTRON RADIAT LAB,STANFORD,CA 94309. RI Scott, Michael/B-7859-2013; Filipponi, Adriano/P-7796-2015 OI Filipponi, Adriano/0000-0002-3870-5853 NR 44 TC 35 Z9 35 U1 1 U2 7 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0002-7863 J9 J AM CHEM SOC JI J. Am. Chem. Soc. PD MAR 12 PY 1997 VL 119 IS 10 BP 2470 EP 2478 DI 10.1021/ja963300i PG 9 WC Chemistry, Multidisciplinary SC Chemistry GA WM814 UT WOS:A1997WM81400016 ER PT J AU Busch, DB vanVuuren, H deWit, J Collins, A Zdzienicka, MZ Mitchell, DL Brookman, KW Stefanini, M Riboni, R Thompson, LH Albert, RB vanGool, AJ Hoeijmakers, J AF Busch, DB vanVuuren, H deWit, J Collins, A Zdzienicka, MZ Mitchell, DL Brookman, KW Stefanini, M Riboni, R Thompson, LH Albert, RB vanGool, AJ Hoeijmakers, J TI Phenotypic heterogeneity in nucleotide excision repair mutants of rodent complementation groups 1 and 4 SO MUTATION RESEARCH-DNA REPAIR LA English DT Article DE allele; Chinese hamster ovary (CHO); DNA repair; mitomycin C; mutant; ultraviolet light ID CROSS-LINKING AGENTS; HAMSTER OVARY CELLS; PIGMENTOSUM GROUP-F; DNA-REPAIR; XERODERMA-PIGMENTOSUM; CHO CELLS; CYCLOBUTANE DIMERS; COCKAYNES-SYNDROME; SENSITIVE MUTANTS; 6-4 PHOTOPRODUCTS AB Rodent ultraviolet light (UV)-sensitive mutant cells in complementation groups (CGs) 1 and 4 normally are known for their extraordinary (similar to 80-100 x) sensitivity to mitomycin C (MMC), although some CG1 mutants with reduced MMC sensitivity were previously reported (Stefanini et al. (1987) Cytotechnology 1, 91). We report here new CG1 and CG4 mutants with only 1.6-10 x wild-type MMC sensitivity despite low unscheduled DNA synthesis (UDS) levels, Mutant UV140, in UV CG4, has similar to 3.8 x the UV sensitivity of parental line AA8, similar to 1.6 x wild-type MMC sensitivity, wild-type X-ray and ethyl methanesulfonate (EMS) sensitivity, and is only slightly (similar to 1.4 x)hypermutable to 8-azaadenine resistance by UV light. It has moderately decreased incision of UV-damaged DNA, has moderately decreased removal of (6-4) photoproducts, and is profoundly deficient in UDS after UV. After UV, it shows abnormally decreased DNA synthesis and persistently decreased RNA synthesis. In addition a cell-free extract of this mutant displays strongly reduced nucleotide excision repair synthesis using DNA treated with N-acetoxy-acetyl-amino-fluorene (AAF). The extract selectively fails to complement extracts of group 1 and 4 mutants consistent with the notion that the affected proteins, ERCC1 and ERCC4, are part of the same complex and that mutations in one subunit also affect the other component. Mutant UV212 is a CG1 mutant with similar to 3.3 x wild-type UV and similar to 5-10 x wild-type MMC sensitivity, with profoundly deficient UDS and hypermutability (similar to 5.8 x) by UV. Mutant UV201, probably in CG1, is only slightly (similar to 1.5 x) UV-sensitive and has near wild-type (1.02 x) UV mutability. These unusual group 1 and 4 mutants demonstrate that the unique UV and MMC sensitivity phenotypes displayed by these groups can be separated and support the idea that they are the result of distinct repair functions of the corresponding ERCC1 and ERCC4 genes: nucleotide excision repair for UV lesions and a separate repair pathway for removal of interstrand crosslinks. C1 ACAD ZIEKENHUIS,AFDELING HAEMATOL,NL-3584 CX UTRECHT,NETHERLANDS. ERASMUS UNIV ROTTERDAM,DEPT CELL BIOL & GENET,NL-3000 DR ROTTERDAM,NETHERLANDS. UNIV ABERDEEN,BOYD ORR RES CTR,ABERDEEN,SCOTLAND. ROWETT RES INST,ABERDEEN AB2 9SB,SCOTLAND. LEIDEN UNIV,DEPT GENET RADIAT GENET & CHEM MUTAGENESIS,LEIDEN,NETHERLANDS. JA COHEN INST,INTERUNIV RES INST RADIOPATHOL & RADIAT PROTECT,NL-2300 RA LEIDEN,NETHERLANDS. UNIV TEXAS,MD ANDERSON CANC CTR,DIV SCI PK RES,SMITHVILLE,TX 78957. LAWRENCE LIVERMORE NATL LAB,DIV BIOMED SCI,LIVERMORE,CA 94550. CNR,IST GENET BIOCHIM & EVOLUZIONIST,I-27100 PAVIA,ITALY. IMPERIAL CANC RES FUND,CLAIRE HALL LABS,S MIMMS EN6 3LD,HERTS,ENGLAND. RP Busch, DB (reprint author), ARMED FORCES INST PATHOL,DEPT ENVIRONM & TOXICOL PATHOL,WASHINGTON,DC 20306, USA. RI van Gool, Alain/G-3806-2010; Gool, A.J./L-4328-2015 FU NCI NIH HHS [CA04484]; NCRR NIH HHS [RR00961]; NIGMS NIH HHS [GM22021] NR 40 TC 26 Z9 26 U1 1 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-8777 J9 MUTAT RES-DNA REPAIR JI Mutat. Res.-DNA Repair PD MAR 12 PY 1997 VL 383 IS 2 BP 91 EP 106 DI 10.1016/S0921-8777(96)00048-1 PG 16 WC Biotechnology & Applied Microbiology; Genetics & Heredity; Toxicology SC Biotechnology & Applied Microbiology; Genetics & Heredity; Toxicology GA WN268 UT WOS:A1997WN26800001 PM 9088342 ER PT J AU Rubehn, T Wozniak, GJ Phair, L Moretto, LG Yu, KM AF Rubehn, T Wozniak, GJ Phair, L Moretto, LG Yu, KM TI Characterization of nuclear physics targets using Rutherford backscattering and particle induced X-ray emission SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article AB Rutherford backscattering and particle induced X-ray emission have been utilized to precisely characterize targets used in nuclear fission experiments. The method allows for a fast and non-destructive determination of target thickness, homogeneity and element composition. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV SCI MAT,BERKELEY,CA 94720. RP Rubehn, T (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV NUCL SCI,BERKELEY,CA 94720, USA. RI Yu, Kin Man/J-1399-2012 OI Yu, Kin Man/0000-0003-1350-9642 NR 17 TC 2 Z9 2 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD MAR 11 PY 1997 VL 387 IS 3 BP 328 EP 332 DI 10.1016/S0168-9002(96)01217-X PG 5 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA WU323 UT WOS:A1997WU32300004 ER PT J AU Ajaltouni, Z Albiol, F Alifanov, A Amaral, P Ambrosini, G Amorim, A Anderson, K Astvatsaturov, A Aubert, B Auge, E Autiero, D Azuelos, G Badaud, F Baisin, L Battistoni, G Bazan, A Bee, C Bellettini, G Berglund, S Berset, JC Blaj, C Blanchot, G Blucher, E Bogush, A Bohm, C Boldea, V Borisov, O Bosman, M Bouhemaid, N Brette, P Bromberg, C Brossard, M Budagov, J Buono, S Caloba, L Camin, DV Canton, B Casado, P Cavalli, D CavalliSforza, M Cavasinni, V Chadelas, R Chase, R Chekhtman, A Chevaleyre, JC Chevalley, JL ChirikovZorin, I Chlachidze, G Chollet, JC Cobal, M Cogswell, F Colas, J Collot, J Cologna, S Constantinescu, S Costa, G Costanzo, D Cozzi, L Crouau, M Dargent, P Daudon, F David, M Davidek, T Dawson, J De, K delaTaille, C DelPrete, T Depommier, P deSaintignon, P DeSanto, A Dinkespiller, B DiGirolamo, B Dita, S Dolejsi, J Dolezal, Z Downing, R Dugne, JJ Duval, PY Dzahini, D Efthymiopoulos, I Errede, D Errede, S Etienne, F Evans, H Fassnacht, P Fedyakin, N Ferrari, A Ferreira, P Ferrer, A Flaminio, V Fouchez, D Fournier, D Fumagalli, G Gallas, E Gaspar, M Gianotti, F Gildemeister, O Gingrich, DM Glagolev, V Golubev, V Gomes, A Gonzalez, J Gordon, HA Grabsky, V Hakopian, H Haney, M Hellman, S Henriques, A Holmgren, S Honore, PF Hostachy, JY Huston, J Ivanyushenkov, Y Jezequel, S Johansson, E JonAnd, K Jones, R Juste, A Kakurin, S Karapetian, G Karyukhin, A Khokhlov, Y Klyukhin, V Kolomoets, V Kopikov, S Kostrikov, M Kovtun, V Kukhtin, V Kulagin, M Kulchitsky, Y Laborie, G Lami, S Lapin, V Lebedev, A Lefebvre, M Leflour, T Leitner, R LeonFlorian, E Leroy, C LeVanSuu, A Li, J Liba, I Linossier, O Lokajicek, M Lomakin, Y Lomakina, O LundJensen, B Mahout, G Maio, A Malyukov, S Mandelli, L Mansoulie, B Mapelli, L Marin, CP Marroquin, F Martin, L Mazzanti, M Mazzoni, E Merritt, F Michel, B Miller, R Minashvili, I Miotto, A Miralles, L Mnatsakanian, E Monnier, E Montarou, G Mornacchi, G Muanza, GS Nagy, E Nemecek, S Nessi, M Nicoleau, S Noppe, JM Olivetto, C Orteu, S Padilla, C Pallin, D Pantea, D Parrour, G Pereira, A Perini, L Perlas, JA Petroff, P Pilcher, J Pinfold, JL PlothowBesch, H Poggioli, L Poirot, S Polesello, G Price, L Protopopov, Y Proudfoot, J Pukhov, O Radeka, V Rahm, D Reinmuth, G Renardy, JF Renzoni, G Resconi, S Richards, R Riu, I Romanov, V Ronceux, B Rumyantsev, V Russakovich, N Sala, P Sanders, H Sauvage, G Savard, P SavoyNavarro, A Sawyer, L Says, LP Schaffer, A Scheel, C Schwemling, P Schwindling, J SeguinMoreau, N Seixas, JM Sellden, B Seman, M Semenov, A Senchishin, V Serin, L Shchelchkov, A Shevtsov, V Shochet, M Sidorov, V Simaitis, V Simion, S Sissakian, A Solodkov, A Sonderegger, P Soustruznik, K Stanek, R Starchenko, E Stephani, D Stephens, R Studenov, S Suk, M Surkov, A Tang, F Tardell, S Tas, P Teiger, J Teubert, F Thaler, J Tisserand, V Tisserant, S Tokar, S Topilin, N Trka, Z Turcot, A Turcotte, M Valkar, S Vartapetian, A Vazeille, F Vichou, I Vinogradov, V Vorozhtsov, S Vuillemin, V Wagner, D White, A WingerterSeez, I Yamdagni, N Yarygin, G Yosef, C Zaitsev, A Zdrazil, M Zitoun, R Zolnierowski, YP AF Ajaltouni, Z Albiol, F Alifanov, A Amaral, P Ambrosini, G Amorim, A Anderson, K Astvatsaturov, A Aubert, B Auge, E Autiero, D Azuelos, G Badaud, F Baisin, L Battistoni, G Bazan, A Bee, C Bellettini, G Berglund, S Berset, JC Blaj, C Blanchot, G Blucher, E Bogush, A Bohm, C Boldea, V Borisov, O Bosman, M Bouhemaid, N Brette, P Bromberg, C Brossard, M Budagov, J Buono, S Caloba, L Camin, DV Canton, B Casado, P Cavalli, D CavalliSforza, M Cavasinni, V Chadelas, R Chase, R Chekhtman, A Chevaleyre, JC Chevalley, JL ChirikovZorin, I Chlachidze, G Chollet, JC Cobal, M Cogswell, F Colas, J Collot, J Cologna, S Constantinescu, S Costa, G Costanzo, D Cozzi, L Crouau, M Dargent, P Daudon, F David, M Davidek, T Dawson, J De, K delaTaille, C DelPrete, T Depommier, P deSaintignon, P DeSanto, A Dinkespiller, B DiGirolamo, B Dita, S Dolejsi, J Dolezal, Z Downing, R Dugne, JJ Duval, PY Dzahini, D Efthymiopoulos, I Errede, D Errede, S Etienne, F Evans, H Fassnacht, P Fedyakin, N Ferrari, A Ferreira, P Ferrer, A Flaminio, V Fouchez, D Fournier, D Fumagalli, G Gallas, E Gaspar, M Gianotti, F Gildemeister, O Gingrich, DM Glagolev, V Golubev, V Gomes, A Gonzalez, J Gordon, HA Grabsky, V Hakopian, H Haney, M Hellman, S Henriques, A Holmgren, S Honore, PF Hostachy, JY Huston, J Ivanyushenkov, Y Jezequel, S Johansson, E JonAnd, K Jones, R Juste, A Kakurin, S Karapetian, G Karyukhin, A Khokhlov, Y Klyukhin, V Kolomoets, V Kopikov, S Kostrikov, M Kovtun, V Kukhtin, V Kulagin, M Kulchitsky, Y Laborie, G Lami, S Lapin, V Lebedev, A Lefebvre, M Leflour, T Leitner, R LeonFlorian, E Leroy, C LeVanSuu, A Li, J Liba, I Linossier, O Lokajicek, M Lomakin, Y Lomakina, O LundJensen, B Mahout, G Maio, A Malyukov, S Mandelli, L Mansoulie, B Mapelli, L Marin, CP Marroquin, F Martin, L Mazzanti, M Mazzoni, E Merritt, F Michel, B Miller, R Minashvili, I Miotto, A Miralles, L Mnatsakanian, E Monnier, E Montarou, G Mornacchi, G Muanza, GS Nagy, E Nemecek, S Nessi, M Nicoleau, S Noppe, JM Olivetto, C Orteu, S Padilla, C Pallin, D Pantea, D Parrour, G Pereira, A Perini, L Perlas, JA Petroff, P Pilcher, J Pinfold, JL PlothowBesch, H Poggioli, L Poirot, S Polesello, G Price, L Protopopov, Y Proudfoot, J Pukhov, O Radeka, V Rahm, D Reinmuth, G Renardy, JF Renzoni, G Resconi, S Richards, R Riu, I Romanov, V Ronceux, B Rumyantsev, V Russakovich, N Sala, P Sanders, H Sauvage, G Savard, P SavoyNavarro, A Sawyer, L Says, LP Schaffer, A Scheel, C Schwemling, P Schwindling, J SeguinMoreau, N Seixas, JM Sellden, B Seman, M Semenov, A Senchishin, V Serin, L Shchelchkov, A Shevtsov, V Shochet, M Sidorov, V Simaitis, V Simion, S Sissakian, A Solodkov, A Sonderegger, P Soustruznik, K Stanek, R Starchenko, E Stephani, D Stephens, R Studenov, S Suk, M Surkov, A Tang, F Tardell, S Tas, P Teiger, J Teubert, F Thaler, J Tisserand, V Tisserant, S Tokar, S Topilin, N Trka, Z Turcot, A Turcotte, M Valkar, S Vartapetian, A Vazeille, F Vichou, I Vinogradov, V Vorozhtsov, S Vuillemin, V Wagner, D White, A WingerterSeez, I Yamdagni, N Yarygin, G Yosef, C Zaitsev, A Zdrazil, M Zitoun, R Zolnierowski, YP TI Results from a combined test of an electromagnetic liquid argon calorimeter with a hadronic scintillating-tile calorimeter SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article ID SHOWER PUNCHTHROUGH; PERFORMANCE; IRON AB The first combined test of an electromagnetic liquid argon accordion calorimeter and a hadronic scintillating-tile calorimeter was carried out at the CERN SPS, These devices are prototypes of the barrel calorimeter of the future ATLAS experiment at the LHC. The energy resolution of pions in the energy range from 20 to 300 GeV at an incident angle a of about 11 degrees is well-described by the expression sigma/E = ((46.5 +/- 6.0)%/root E + (1.2 +/- 0.3)%) + (3.2 +/- 0.4) GeV/E. Shower profiles, shower leakage, and the angular resolution of hadronic showers were also studied. C1 CERN,CH-1211 GENEVA 23,SWITZERLAND. UNIV MILAN,I-20122 MILAN,ITALY. JOINT INST NUCL RES DUBNA,DUBNA,RUSSIA. UNIV ALBERTA,EDMONTON,AB,CANADA. LAPP,ANNECY,FRANCE. ARGONNE NATL LAB,ARGONNE,IL 60439. UNIV TEXAS,ARLINGTON,TX 76019. UNIV AUTONOMA BARCELONA,INST FIS ALTES ENERGIES,E-08193 BARCELONA,SPAIN. BROOKHAVEN NATL LAB,UPTON,NY 11973. INST ATOM PHYS,R-76900 BUCHAREST,ROMANIA. UNIV CHICAGO,CHICAGO,IL 60637. UNIV CLERMONT FERRAND,LPC CLERMONT FERRAND,CNRS,IN2P3,CLERMONT FERRAN,FRANCE. COLUMBIA UNIV,NEVIS LABS,IRVINGTON,NY. UNIV GRENOBLE 1,ISN,CNRS,IN2P3,F-38041 GRENOBLE,FRANCE. UNIV LISBON,FCUL,P-1699 LISBON,PORTUGAL. LIP,P-1000 LISBON,PORTUGAL. UNIV AUTONOMA MADRID,E-28049 MADRID,SPAIN. CPP,MARSEILLE,FRANCE. MICHIGAN STATE UNIV,E LANSING,MI 48824. UNIV MILAN,MILAN,ITALY. IST NAZL FIS NUCL,I-20133 MILAN,ITALY. ASB,INST PHYS,MINSK,BYELARUS. UNIV MONTREAL,MONTREAL,PQ,CANADA. LAL,ORSAY,FRANCE. UNIV PARIS 06,LPNHE,F-75252 PARIS 05,FRANCE. UNIV PARIS 07,LPNHE,F-75221 PARIS 05,FRANCE. UNIV PAVIA,I-27100 PAVIA,ITALY. IST NAZL FIS NUCL,I-27100 PAVIA,ITALY. UNIV PISA,PISA,ITALY. IST NAZL FIS NUCL,PISA,ITALY. CHARLES UNIV,PRAGUE,CZECH REPUBLIC. ACAD SCI CZECH REPUBL,PRAGUE,CZECH REPUBLIC. INST HIGH ENERGY PHYS,PROTVINO,RUSSIA. UFRJ,COPPE,EE,RIO JANEIRO,BRAZIL. UNIV STOCKHOLM,S-10691 STOCKHOLM,SWEDEN. ROYAL INST TECHNOL,S-10044 STOCKHOLM,SWEDEN. UNIV ILLINOIS,CHICAGO,IL 60680. IFIC,VALENCIA,SPAIN. UNIV VICTORIA,VICTORIA,BC V8W 2Y2,CANADA. YEREVAN PHYS INST,YEREVAN 375036,ARMENIA. RI David, Mario/C-4664-2012; Zaitsev, Alexandre/B-8989-2017; Klyukhin, Vyacheslav/D-6850-2012; sala, paola/E-2868-2013; De, Kaushik/N-1953-2013; Nemecek, Stanislav/G-5931-2014; Bosman, Martine/J-9917-2014; Cavalli-Sforza, Matteo/H-7102-2015; Ferrer, Antonio/H-2942-2015; Pacheco Pages, Andres/C-5353-2011; Solodkov, Alexander/B-8623-2017; Karyukhin, Andrey/J-3904-2014; OI Zaitsev, Alexandre/0000-0002-4961-8368; Klyukhin, Vyacheslav/0000-0002-8577-6531; Gomes, Agostinho/0000-0002-5940-9893; sala, paola/0000-0001-9859-5564; De, Kaushik/0000-0002-5647-4489; Bosman, Martine/0000-0002-7290-643X; Ferrer, Antonio/0000-0003-0532-711X; Pacheco Pages, Andres/0000-0001-8210-1734; Solodkov, Alexander/0000-0002-2737-8674; Karyukhin, Andrey/0000-0001-9087-4315; Maio, Amelia/0000-0001-9099-0009; Amorim, Antonio/0000-0003-0638-2321; Colomer, Kiko Albiol/0000-0002-3824-2246 NR 34 TC 11 Z9 11 U1 2 U2 4 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD MAR 11 PY 1997 VL 387 IS 3 BP 333 EP 351 DI 10.1016/S0168-9002(97)00075-2 PG 19 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA WU323 UT WOS:A1997WU32300005 ER PT J AU Crittenden, RR Dzierba, AR Gunter, J Lindenbusch, R Rust, DR Scott, E Smith, PT Sulanke, T Teige, S Brabson, BB Adams, T Bishop, JM Cason, NM LoSecco, JM Manak, JJ Sanjari, AH Shephard, WD Steinike, DL Taegar, SA Thompson, DR Chung, SU Hackenburg, RW Olchanski, C Weygand, DP Willutzki, HJ Denisov, S Dushkin, A Kochetkov, V Lipaev, V Popov, A Shein, I Soldatov, A BarYam, Z Cummings, JP Dowd, JP Eugenio, P Hayek, M Kern, W King, E Anoshina, EV Bodyagin, VA Demianov, AI Gribushin, AM Kodolova, OL Korotkikh, VL Kostin, MA Ostrovidov, AI Sarycheva, LI Sinev, NB Vardanyan, IN Yershov, AA Brown, DS Pedlar, TK Seth, KK Wise, J Zhao, D Adams, GS Napolitano, J Mozar, M Smith, JA Witkowski, M AF Crittenden, RR Dzierba, AR Gunter, J Lindenbusch, R Rust, DR Scott, E Smith, PT Sulanke, T Teige, S Brabson, BB Adams, T Bishop, JM Cason, NM LoSecco, JM Manak, JJ Sanjari, AH Shephard, WD Steinike, DL Taegar, SA Thompson, DR Chung, SU Hackenburg, RW Olchanski, C Weygand, DP Willutzki, HJ Denisov, S Dushkin, A Kochetkov, V Lipaev, V Popov, A Shein, I Soldatov, A BarYam, Z Cummings, JP Dowd, JP Eugenio, P Hayek, M Kern, W King, E Anoshina, EV Bodyagin, VA Demianov, AI Gribushin, AM Kodolova, OL Korotkikh, VL Kostin, MA Ostrovidov, AI Sarycheva, LI Sinev, NB Vardanyan, IN Yershov, AA Brown, DS Pedlar, TK Seth, KK Wise, J Zhao, D Adams, GS Napolitano, J Mozar, M Smith, JA Witkowski, M TI A 3000 element lead-glass electromagnetic calorimeter SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article DE calorimeter; lead glass; trigger processor ID DRIFT CHAMBER SYSTEM AB A 3045 element lead glass calorimeter and an associated fast trigger processor have been constructed, tested and implemented in BNL experiment E852 in conjunction with the multi-particle spectrometer (MPS). Approximately, 10(9) all-neutral and neutral plus charged triggers were recorded with this apparatus during data runs in 1994 and 1995. This paper reports on the construction, testing and performance of this lead glass calorimeter and the associated trigger processor. C1 INDIANA UNIV,DEPT PHYS,BLOOMINGTON,IN 47405. UNIV NOTRE DAME,DEPT PHYS,NOTRE DAME,IN 46556. INST HIGH ENERGY PHYS,PROTVINO,RUSSIA. SE MASSACHUSETTS UNIV,DEPT PHYS,N DARTMOUTH,MA 02747. MOSCOW MV LOMONOSOV STATE UNIV,INST NUCL PHYS,MOSCOW,RUSSIA. NORTHWESTERN UNIV,DEPT PHYS,EVANSTON,IL 60208. RENSSELAER POLYTECH INST,DEPT PHYS,TROY,NY 12180. BROOKHAVEN NATL LAB,DEPT PHYS,LI,UPTON,NY 11973. RI Demianov, Andrei/E-4565-2012; Vardanyan, Irina/K-7981-2012; Gribushin, Andrei/J-4225-2012 NR 17 TC 28 Z9 28 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD MAR 11 PY 1997 VL 387 IS 3 BP 377 EP 394 DI 10.1016/S0168-9002(97)00101-0 PG 18 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA WU323 UT WOS:A1997WU32300009 ER PT J AU Armstrong, DJ Smith, AV AF Armstrong, DJ Smith, AV TI Demonstration of a frequency-modulated, pulsed optical parametric oscillator SO APPLIED PHYSICS LETTERS LA English DT Article ID SPECTROSCOPY; LASER AB We demonstrate that injection seeding a pulsed optical parametric oscillator with frequency modulated cw light with a modulation period equal to the cavity round-trip time produces pulses that have the same modulated character as the seed. A sensitivity of 10(-3) was demonstrated for these pulses in frequency-modulated absorption measurements. (C) 1997 American Institute of Physics. C1 SANDIA NATL LABS,LASERS OPT & REMOTE SENSING DEPT,ALBUQUERQUE,NM 87185. NR 6 TC 1 Z9 1 U1 0 U2 1 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 MAR 10 PY 1997 VL 70 IS 10 BP 1227 EP 1229 DI 10.1063/1.118537 PG 3 WC Physics, Applied SC Physics GA WL865 UT WOS:A1997WL86500014 ER PT J AU Li, F Tang, H Anderegg, J Shinar, J AF Li, F Tang, H Anderegg, J Shinar, J TI Fabrication and electroluminescence of double-layered organic light-emitting diodes with the Al2O3/Al cathode SO APPLIED PHYSICS LETTERS LA English DT Article ID POLY(P-PHENYLENE VINYLENE); INTERFACE FORMATION; TRANSPORT; POLYMERS; DEVICES; DIAMINE; CA AB The effects of a controlled Al2O3 buffer layer on the behavior of highly efficient vacuum evaporated aqua-regia-treated indium tin oxide (ITO)/triphenyl diamine (TPD)/8-tris-hydroxyquino-line aluminum Alq(3)/Al2O3/Al light-emitting diodes are described. It is found that, with a buffer layer of suitable thickness, both current injection and electroluminescence output are significantly enhanced. The enhancement is believed to be due to increased charge carrier density near the TPD/Alq(3) interface that results from enhanced electron tunneling, and removal of exciton-quenching gap states that are intrinsic to the Alq(3)/Al interface. (C) 1997 American Institute of Physics. C1 IOWA STATE UNIV SCI & TECHNOL,US DOE,AMES LAB,AMES,IA 50011. IOWA STATE UNIV SCI & TECHNOL,DEPT PHYS & ASTRON,AMES,IA 50011. NR 28 TC 227 Z9 248 U1 2 U2 21 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 MAR 10 PY 1997 VL 70 IS 10 BP 1233 EP 1235 DI 10.1063/1.118539 PG 3 WC Physics, Applied SC Physics GA WL865 UT WOS:A1997WL86500016 ER PT J AU Mauche, CW Lee, YP Kallman, TR AF Mauche, CW Lee, YP Kallman, TR TI Ultraviolet emission-line ratios of cataclysmic variables SO ASTROPHYSICAL JOURNAL LA English DT Article DE atomic processes; line, formation; stars, novae, cataclysmic variables; ultraviolet, stars ID OLD-NOVA GK; DIELECTRONIC RECOMBINATION; ROSAT OBSERVATIONS; UV SPECTROSCOPY; Z CHAMAELEONTIS; IUE SPECTRA; DWARF NOVAE; V-SAGITTAE; OUTBURST; AM AB We present a statistical analysis of the ultraviolet emission lines of cataclysmic variables (CVs) based on approximate to 430 ultraviolet spectra of 20 sources extracted from the International Ultraviolet Explorer Uniform Low Dispersion Archive. These spectra are used to measure the emission-line fluxes of N V, Si IV, C IV, and He II and to construct diagnostic flux ratio diagrams. We investigate the flux ratio parameter space populated by individual CVs and by various CV subclasses (e.g., AM Her stars, DQ Her stars, dwarf novae, nova-like variables). For most systems, these ratios are clustered within a range of similar to 1 decade for log Si IV/C IV approximate to 0.5 and log He II/C IV N approximate to-1.0 and similar to 1.5 decades for log N V/C IV approximate to-0.25. These ratios are compared to photoionization and collisional ionization models to constrain the excitation mechanism and the physical conditions of the line-emitting gas. We find that the collisional models do the poorest job of reproducing the data. The photoionization models reproduce the Si IV/C IV line ratios for some shapes of the ionizing spectrum, but the predicted N V/C IV line ratios are simultaneously too low by typically similar to 0.5 decades. Worse, for no parameters are any of the models able to reproduce the observed He II/C IV line ratios; this ratio is far too small in the collisional and scattering models and too large by typically similar to 0.5 decades in the photoionization models. C1 UNIV CALIF DAVIS, DEPT PHYS, DAVIS, CA 95616 USA. NASA, GODDARD SPACE FLIGHT CTR, HIGH ENERGY ASTROPHYS LAB, GREENBELT, MD 20771 USA. RP Mauche, CW (reprint author), LAWRENCE LIVERMORE NATL LAB, L-41, POB 808, LIVERMORE, CA 94550 USA. NR 45 TC 45 Z9 45 U1 0 U2 0 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD MAR 10 PY 1997 VL 477 IS 2 BP 832 EP 847 DI 10.1086/303717 PN 1 PG 16 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA WM090 UT WOS:A1997WM09000027 ER PT J AU Phillips, M Rice, RH Djian, P Green, H AF Phillips, M Rice, RH Djian, P Green, H TI The involucrin gene of the tree shrew: Recent repeat additions and the relocation of cysteine codons SO GENE LA English DT Article DE gene conversion; tandem repeats; protein evolution ID HIGHER PRIMATES; MIDDLE REGION; CROSS-LINKING; EVOLUTION; HOMINOIDS; PROTEINS; ENVELOPE; SEGMENT AB The coding region of the involucrin gene of Tupaia glis has been cloned and sequenced. It resembles the involucrin coding region of other non-anthropoid mammals in possessing a segment of related, short tandem repeats at a defined location, but in Tupaia, there has been recent serial duplication of a repeat into which a cysteine codon had earlier been introduced. As a result of the duplication, there is a total of as many as six cysteine codons in the segment of repeats, a number larger than for any other species yet examined. In Rattus there has been a comparable but independent addition of cysteine codons, and both Tupaia and Rattus have eliminated an otherwise conserved cysteine codon 75 located close to but outside the segment of repeats. In Tupaia, this elimination probably occurred by gene conversion. Also independently, the gene of Canis has added cysteine codons to the segment of repeats but has not yet lost cysteine 75. It is proposed that the gain and the loss of cysteine codons are parts of a multi-stage program of cysteine relocation. C1 CTR RECH ENDOCRINOL MOL & DEV,MEUDON,FRANCE. LAWRENCE LIVERMORE NATL LAB,DEPT ENVIRONM TOXICOL,DAVIS,CA 95616. HARVARD UNIV,SCH MED,DEPT CELL BIOL,BOSTON,MA 02115. NR 22 TC 6 Z9 7 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0378-1119 J9 GENE JI Gene PD MAR 10 PY 1997 VL 187 IS 1 BP 29 EP 34 DI 10.1016/S0378-1119(96)00654-3 PG 6 WC Genetics & Heredity SC Genetics & Heredity GA WN016 UT WOS:A1997WN01600004 PM 9073063 ER PT J AU Akita, M Nielsen, E Keegstra, K AF Akita, M Nielsen, E Keegstra, K TI Identification of protein transport complexes in the chloroplastic envelope membranes via chemical cross-linking SO JOURNAL OF CELL BIOLOGY LA English DT Article ID PRECURSOR PROTEINS; IMPORT MACHINERY; INNER MEMBRANE; RIBULOSE-1,5-BISPHOSPHATE CARBOXYLASE; NUCLEOSIDE TRIPHOSPHATES; DYNAMIC INTERACTION; SMALL SUBUNIT; BINDING; HSP70; TRANSLOCATION AB Transport of cytoplasmically synthesized proteins into chloroplasts uses an import machinery present in the envelope membranes. To identify the components of this machinery and to begin to examine how these components interact during transport. chemical cross-linking was performed on intact chloroplasts containing precursor proteins trapped at a particular stage of transport by ATP limitation. Large crosslinked complexes were observed using three different reversible homobifunctional cross-linkers. Three outer envelope membrane proteins (OEP86, OEP75, and OEP34) and one inner envelope membrane protein (IEP110), previously reported to be involved in protein import, were identified as components of these complexes. In addition to these membrane proteins, a stromal member of the hsp100 family, ClpC, was also present in the complexes. We propose that ClpC functions as a molecular chaperone, cooperating with other components to accomplish the transport of precursor proteins into chloroplasts. We also propose that each envelope membrane contains distinct translocation complexes and that a portion of these interact to form contact sites even in the absence of precursor proteins. C1 MICHIGAN STATE UNIV, PLANT RES LAB, MSU, DOE, E LANSING, MI 48824 USA. RI Nielsen, Erik/G-5843-2013 NR 49 TC 143 Z9 147 U1 0 U2 7 PU ROCKEFELLER UNIV PRESS PI NEW YORK PA 950 THIRD AVE, 2ND FLR, NEW YORK, NY 10022 USA SN 0021-9525 EI 1540-8140 J9 J CELL BIOL JI J. Cell Biol. PD MAR 10 PY 1997 VL 136 IS 5 BP 983 EP 994 DI 10.1083/jcb.136.5.983 PG 12 WC Cell Biology SC Cell Biology GA WN154 UT WOS:A1997WN15400003 PM 9060464 ER PT J AU Burgmann, R Segall, P Lisowski, M Svarc, J AF Burgmann, R Segall, P Lisowski, M Svarc, J TI Postseismic strain following the 1989 Loma Prieta earthquake from GPS and leveling measurements SO JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH LA English DT Article ID SAN-ANDREAS FAULT; GLOBAL POSITIONING SYSTEM; CRUSTAL DEFORMATION; CALIFORNIA EARTHQUAKE; STRESS DIFFUSION; PLATE BOUNDARIES; CALAVERAS FAULT; CRUZ MOUNTAINS; OCTOBER 17; SLIP AB Postseismic deformation in the 5 years following the 1989 Loma Prieta earthquake has been measured with the Global Positioning System and precise leveling. Postearthquake velocities at distances greater than similar to 20 km from the coseismic rupture are not significantly different from those observed in the 20 years prior to the earthquake. However, velocities at stations within similar to 20 km of the rupture exceed preearthquake rates and exhibit unanticipated contraction normal to the strike of the San Andreas fault system. A combination of forward modeling and nonlinear optimization suggests that the observed postseismic deformations were caused by aseismic oblique reverse slip averaging 2.9 cm/yr on the San Andreas fault and/or the Loma Prieta rupture zone and 2.4 cm/yr reverse slip along a buried fault within the Foothills thrust belt. The best fitting sources of postseismic deformation are all located at depths of less than 15 km. We find no evidence for accelerated flow or shear below the Loma Prieta rupture in the first 5 years following the earthquake. The inferred postseismic slip is likely to have been caused by the coseismic stress change updip of the 1989 rupture. C1 US GEOL SURVEY, HAWAIAN VOLCANO OBSERV, HAWAII NATL PK, HI 96718 USA. STANFORD UNIV, DEPT GEOPHYS, STANFORD, CA 94305 USA. US GEOL SURVEY, MENLO PK, CA 94025 USA. RP Burgmann, R (reprint author), LAWRENCE LIVERMORE NATL LAB, DEPT GEOL, DAVIS, CA 95616 USA. NR 75 TC 83 Z9 87 U1 0 U2 5 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-9313 EI 2169-9356 J9 J GEOPHYS RES-SOL EA JI J. Geophys. Res.-Solid Earth PD MAR 10 PY 1997 VL 102 IS B3 BP 4933 EP 4955 DI 10.1029/96JB03171 PG 23 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA WM584 UT WOS:A1997WM58400001 ER PT J AU Bawden, GW Donnellan, A Kellogg, LH Dong, DN Rundle, JB AF Bawden, GW Donnellan, A Kellogg, LH Dong, DN Rundle, JB TI Geodetic measurements of horizontal strain near the White Wolf fault, Kern County, California, 1926-1993 SO JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH LA English DT Article ID SAN-ANDREAS FAULT; SOUTHERN-CALIFORNIA; CONTEMPORARY SEISMICITY; CRUSTAL DEFORMATION; JOAQUIN VALLEY; EARTHQUAKE; ACCUMULATION AB The White Wolf fault, located north of the Big Bend segment of the San Andreas fault, is the NE-SW trending, left lateral-oblique reverse fault responsible for the M(S)=7.8 1952 Kern County earthquake. We combined Global Positioning System (GPS) measurements with historical triangulation and trilateration data to determine changes in the strain rate over 7 decades (1926-1993). We reanalyzed the historical geodetic data and calculated an elevated preseismic (1926-1952) maximum shear strain rate (gamma over dot) of 0.62 +/- 0.16 mu strain/yr across the White Wolf fault. The maximum shear strain rate decreased with distance toward the Garlock fault to 0.09 +/- 0.08 mu strain/yr. In the decade following the earthquake (1952-1963), the near fault gamma over dot was high (0.85 +/-0.23 mu strain/yr), and decreased to 0.23+/-0.13 mu strain/yr across the Garlock fault. In 1993, we resurveyed many of the same monuments with GPS receivers to estimate fault-crossing and off-fault strain rates for the preceding 30 years. Across the White Wolf fault, the maximum shear strain rate (gamma over dot) dropped to 0.19+/-0.07 mu strain/yr. The azimuths of the maximum principal strain rates (phi) for the 1963-1993 epoch rotate from a fault normal orientation (-57 degrees+/-15 degrees) across the White Wolf fault to 11 degrees+/-3 degrees E across the Garlock fault. C1 CALTECH, JET PROP LAB, PASADENA, CA 91109 USA. UNIV COLORADO, CIRES, BOULDER, CO 80309 USA. RP Bawden, GW (reprint author), LAWRENCE LIVERMORE NATL LAB, DEPT GEOL, DAVIS, CA 95616 USA. RI Kellogg, Louise/J-2171-2012 OI Kellogg, Louise/0000-0001-5874-0472 NR 34 TC 20 Z9 20 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-9313 EI 2169-9356 J9 J GEOPHYS RES-SOL EA JI J. Geophys. Res.-Solid Earth PD MAR 10 PY 1997 VL 102 IS B3 BP 4957 EP 4967 DI 10.1029/96JB03554 PG 11 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA WM584 UT WOS:A1997WM58400002 ER PT J AU Stern, LA Durham, WB Kirby, SH AF Stern, LA Durham, WB Kirby, SH TI Grain-size-induced weakening of H2O ices I and II and associated anisotropic recrystallization SO JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH LA English DT Article ID SUPERPLASTIC FLOW; WATER ICE; RHEOLOGY AB Grain-size-dependent flow mechanisms tend to be favored over dislocation creep at low differential stresses and can potentially influence the rheology of low-stress, low-strain rate environments such as those of planetary interiors. We experimentally investigated the effect of reduced grain size on the solid-state flow of water ice I, a principal component of the asthenospheres of many icy moons of the outer solar system, using techniques new to studies of this deformation regime. We fabricated fully dense ice samples of approximate grain size 2 +/- 1 mu m by transforming ''standard'' ice I samples of 250 +/- 50 mu m grain size to the higher-pressure phase ice II, deforming them in the ice II field, and then rapidly releasing the pressure deep into the ice I stability field. At T less than or equal to 200 K, slow growth and rapid nucleation of ice I combine to produce a fine grain size. Constant-strain rate deformation tests conducted on these samples show that deformation rates are less stress sensitive than for standard ice and that the fine-grained material is markedly weaker than standard ice, particularly during the transient approach to steady state deformation. Scanning electron microscope examination of the deformed fine-grained ice samples revealed an unusual microstructure dominated by platelike grains that grew normal to the compression direction, with c axes preferentially oriented parallel to compression. In samples tested at T greater than or equal to 220 K the elongation of the grains is so pronounced that the samples appear finely banded, with aspect ratios of grains approaching 50:1. The anisotropic growth of these crystallographically oriented neoblasts likely contributes to progressive work hardening observed during the transient stage of deformation. We have also documented remarkably similar microstructural development and weak mechanical behavior in fine-grained ice samples partially transformed and deformed in the ice II field. C1 LAWRENCE LIVERMORE NATL LAB, LIVERMORE, CA 94550 USA. RP Stern, LA (reprint author), US GEOL SURVEY, BRANCH EARTHQUAKE GEOL & GEOPHYS, MS 977, 345 MIDDLEFIELD RD, MENLO PK, CA 94025 USA. NR 28 TC 21 Z9 21 U1 1 U2 2 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-9313 EI 2169-9356 J9 J GEOPHYS RES-SOL EA JI J. Geophys. Res.-Solid Earth PD MAR 10 PY 1997 VL 102 IS B3 BP 5313 EP 5325 DI 10.1029/96JB03894 PG 13 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA WM584 UT WOS:A1997WM58400026 ER PT J AU MacDougall, CE AF MacDougall, CE TI Who's learning what? SO NEW REPUBLIC LA English DT Letter RP MacDougall, CE (reprint author), US DOE,WASHINGTON,DC 20545, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU NEW REPUBLIC INC PI WASHINGTON PA 1220 19TH ST NW SUITE 600, WASHINGTON, DC 20036 SN 0028-6583 J9 NEW REPUBLIC JI New Repub. PD MAR 10 PY 1997 VL 216 IS 10 BP 6 EP 6 PG 1 WC Political Science SC Government & Law GA WK426 UT WOS:A1997WK42600002 ER PT J AU Nara, Y Ohnishi, A Harada, T Engel, A AF Nara, Y Ohnishi, A Harada, T Engel, A TI K+ momentum spectrum from (K-, K+) reactions in the intranuclear cascade model SO NUCLEAR PHYSICS A LA English DT Article ID HEAVY-ION COLLISIONS; QUANTUM MOLECULAR-DYNAMICS; MONTE-CARLO CALCULATION; PION-NUCLEAR-REACTIONS; MESON PRODUCTION; ANTISYMMETRIZED VERSION; 2-NUCLEON COLLISIONS; PARTICLE-PRODUCTION; FRAGMENT FORMATION; HADRONIC MATTER AB In the framework of intranuclear cascade (INC) type calculations, we study the momentum spectrum in the reactions (K-,K+) at a beam momentum of 1.65 GeV/c. The INC model calculations are compared with the relativistic impulse approximation (RTA) calculations to perform a detailed study of the reaction mechanism. We find that the INC model can reproduce the experimental data on various targets. Especially, in the low-momentum region, the forward-angle cross sections of the (K-, K+) reaction from light to heavy targets are consistently explained with the two-step strangeness exchange and production processes with various intermediate mesons, and phi, a(0) and f(0) productions and their decay into K+K-. In the two-step processes, inclusion of meson and hyperon resonances is found to be essential. C1 UNIV CALIF BERKELEY, LAWRENCE BERKELEY LAB, DIV NUCL SCI, BERKELEY, CA 94720 USA. SAPPORO GAKUIN UNIV, DEPT SOCIAL INFORMAT, EBETSU, HOKKAIDO 069, JAPAN. KYOTO UNIV, DEPT PHYS, KYOTO 60601, JAPAN. RP Nara, Y (reprint author), HOKKAIDO UNIV, FAC SCI, DEPT PHYS, SAPPORO, HOKKAIDO 060, JAPAN. RI Ohnishi, Akira/F-7403-2011 OI Ohnishi, Akira/0000-0003-1513-0468 NR 68 TC 31 Z9 33 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0375-9474 J9 NUCL PHYS A JI Nucl. Phys. A PD MAR 10 PY 1997 VL 614 IS 4 BP 433 EP 460 DI 10.1016/S0375-9474(96)00427-7 PG 28 WC Physics, Nuclear SC Physics GA WL848 UT WOS:A1997WL84800001 ER PT J AU Clark, RM Asztalos, SJ Baldsiefen, G Becker, JA Bernstein, L Deleplanque, MA Diamond, RM Fallon, P Hibbert, IM Hubel, H Krucken, R Lee, IY Macchiavelli, AO MacLeod, RW Schmid, G Stephens, FS Vetter, K Wadsworth, R Frauendorf, S AF Clark, RM Asztalos, SJ Baldsiefen, G Becker, JA Bernstein, L Deleplanque, MA Diamond, RM Fallon, P Hibbert, IM Hubel, H Krucken, R Lee, IY Macchiavelli, AO MacLeod, RW Schmid, G Stephens, FS Vetter, K Wadsworth, R Frauendorf, S TI Evidence for ''magnetic rotation'' in nuclei: Lifetimes of states in the M1 bands of Pb-198,Pb-199 SO PHYSICAL REVIEW LETTERS LA English DT Article ID DIPOLE BANDS; OBLATE AB Lifetimes of states in four of the M1 bands in Pb-198,Pb-199 have been determined through a Doppler-shift attenuation method measurement performed using the GAMMASPHERE array. The deduced B(M1) values, which are a sensitive probe of the underlying mechanism for generating these sequences, show remarkable agreement with tilted axis cranking (TAG) calculations. The results represent clear evidence for a new concept in nuclear excitations: "magnetic rotation." C1 UNIV BONN, INST STRAHLEN & KERNPHYS, D-53115 BONN, GERMANY. LAWRENCE LIVERMORE NATL LAB, LIVERMORE, CA 94550 USA. UNIV YORK, DEPT PHYS, YORK YO1 5DD, N YORKSHIRE, ENGLAND. FORSCHUNGSZENTRUM ROSSENDORF EV, INST KERN & HADRONENPHYS, D-01314 DRESDEN, GERMANY. RP LAWRENCE BERKELEY LAB, BERKELEY, CA 94720 USA. RI Kruecken, Reiner/A-1640-2013 OI Kruecken, Reiner/0000-0002-2755-8042 NR 16 TC 92 Z9 94 U1 1 U2 5 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 EI 1079-7114 J9 PHYS REV LETT JI Phys. Rev. Lett. PD MAR 10 PY 1997 VL 78 IS 10 BP 1868 EP 1871 DI 10.1103/PhysRevLett.78.1868 PG 4 WC Physics, Multidisciplinary SC Physics GA WM064 UT WOS:A1997WM06400010 ER PT J AU Fabijonas, B Holm, DD Lifschitz, A AF Fabijonas, B Holm, DD Lifschitz, A TI Secondary instabilities of flows with elliptic streamlines SO PHYSICAL REVIEW LETTERS LA English DT Article ID 3-DIMENSIONAL INSTABILITY; STABILITY; DISTURBANCES; EVOLUTION; FLUID AB We examine the stability of flows which are the sum of a linear flow with elliptic streamlines and a transverse standing wave. Such flows are exact solutions of the 3D Euler equations for an inviscid incompressible fluid. We examine the stability of such flows under local 3D high frequency perturbations, which can be viewed as secondary perturbations of the elliptic flow itself. We find that these flows are unstable to such perturbations and compute growth rate in several cases. C1 LOS ALAMOS NATL LAB,DIV THEORET,LOS ALAMOS,NM 87545. LOS ALAMOS NATL LAB,CTR NONLINEAR STUDIES,LOS ALAMOS,NM 87545. RP Fabijonas, B (reprint author), UNIV ILLINOIS,DEPT MATH STAT & COMP SCI,CHICAGO,IL 60607, USA. OI Holm, Darryl D/0000-0001-6362-9912 NR 19 TC 14 Z9 14 U1 0 U2 4 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD MAR 10 PY 1997 VL 78 IS 10 BP 1900 EP 1903 DI 10.1103/PhysRevLett.78.1900 PG 4 WC Physics, Multidisciplinary SC Physics GA WM064 UT WOS:A1997WM06400018 ER PT J AU Tornkvist, O Schroder, E AF Tornkvist, O Schroder, E TI Vortex dynamics in dissipative systems SO PHYSICAL REVIEW LETTERS LA English DT Article ID DEFECT-MEDIATED TURBULENCE; QUANTUM VORTICES; WAVES; FILAMENTS; MODEL AB We derive the exact equation of motion for a vortex in two- and three-dimensional nonrelativistic systems governed by the Ginzburg-Landau equation with complex coefficients. The velocity is given in terms of local gradients of the magnitude and phase of the complex field and is exact also for arbitrarily small intervortex distances. The results for vortices in a superfluid or a superconductor are recovered. C1 NIELS BOHR INST,DK-2100 COPENHAGEN O,DENMARK. RP Tornkvist, O (reprint author), FERMILAB NATL ACCELERATOR LAB,NASA,FERMILAB ASTROPHYS CTR,MS209,POB 500,BATAVIA,IL 60510, USA. RI Schroder, Elsebeth/A-2030-2011 OI Schroder, Elsebeth/0000-0003-4995-3585 NR 30 TC 20 Z9 20 U1 0 U2 1 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD MAR 10 PY 1997 VL 78 IS 10 BP 1908 EP 1911 DI 10.1103/PhysRevLett.78.1908 PG 4 WC Physics, Multidisciplinary SC Physics GA WM064 UT WOS:A1997WM06400020 ER PT J AU Martin, RM Ortiz, G AF Martin, RM Ortiz, G TI Density-polarization-functional theory and long-range correlation in dielectrics - Comment SO PHYSICAL REVIEW LETTERS LA English DT Article C1 LOS ALAMOS NATL LAB,DIV THEORET,LOS ALAMOS,NM 87545. RP Martin, RM (reprint author), UNIV ILLINOIS,LOOMIS LAB PHYS,1110 W GREEN ST,URBANA,IL 61801, USA. NR 4 TC 9 Z9 9 U1 0 U2 3 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD MAR 10 PY 1997 VL 78 IS 10 BP 2028 EP 2028 DI 10.1103/PhysRevLett.78.2028 PG 1 WC Physics, Multidisciplinary SC Physics GA WM064 UT WOS:A1997WM06400050 ER PT J AU Doll, R Gerken, CA VanHove, MA Somorjai, GA AF Doll, R Gerken, CA VanHove, MA Somorjai, GA TI Structure of disordered ethylene adsorbed on Pt(111) analyzed by diffuse LEED: Asymmetrical di-sigma bonding favored SO SURFACE SCIENCE LA English DT Article DE alkenes; electron-solid diffraction; low energy electron diffraction (LEED); low index single crystal surfaces; platinum; surface structure ID ABSORPTION FINE-STRUCTURE; SURFACE-STRUCTURE DETERMINATION; ENERGY ELECTRON-DIFFRACTION; TENSOR LEED; SINGLE-CRYSTAL; STRUCTURE SPECTROSCOPY; BONDED ETHYLENE; LOCAL GEOMETRY; ADSORPTION; C2H4 AB The adsorption structure of ethylene on Pt(111) at 200 K is studied by means of diffuse low-energy electron diffraction (DLEED), analyzing diffuse intensity versus energy, DI(E), curves. The data favor a mixed occupation of two similar sites with the centers of the C-C bonds above both fee and hcp sites and very similar local structures. In each case, the best-fit adsorption geometry is asymmetrical between the two carbon atoms, the molecular axes likely being tilted with respect to the surface plane by about 22 degrees. Substrate relaxation is undetectable. C1 LAWRENCE LIVERMORE NATL LAB, DIV MAT SCI, LIVERMORE, CA 94550 USA. UNIV CALIF BERKELEY, DEPT CHEM, BERKELEY, CA 94720 USA. RI Van Hove, Michel/A-9862-2008 OI Van Hove, Michel/0000-0002-8898-6921 NR 75 TC 47 Z9 47 U1 1 U2 7 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0039-6028 J9 SURF SCI JI Surf. Sci. PD MAR 10 PY 1997 VL 374 IS 1-3 BP 151 EP 161 DI 10.1016/S0039-6028(96)01227-7 PG 11 WC Chemistry, Physical; Physics, Condensed Matter SC Chemistry; Physics GA WN425 UT WOS:A1997WN42500016 ER PT J AU Swartzentruber, BS AF Swartzentruber, BS TI Si ad-dimer interactions with steps and islands on Si(001) SO SURFACE SCIENCE LA English DT Article DE clusters; diffusion and migration; scanning tunneling microscopy; silicon; surface defects; surface diffusion ID SCANNING TUNNELING MICROSCOPY; VARIABLE-TEMPERATURE STM; VICINAL SI(001); SURFACE; DYNAMICS; GROWTH; NUCLEATION; DIFFUSION; KINETICS; BINDING AB The interactions of adsorbed Si dimers with steps and islands on Si(001) are quantified using atom-tracking STM. Diffusing dimers are reflected from steps, sides of islands, and certain surface defect structures. Site-specific free energies are extracted from measurements of lattice-site occupation probabilities of dimers trapped between these reflecting barriers. Relative to the free energy of isolated dimers on a terrace, dimers located at the first lattice site next to SA steps and the sides of islands are bound by 0.05 eV. The binding decreases to half that at the second lattice site, and is indistinguishable from the free-terrace value at a distance of three or more lattice sites. (C) 1997 Elsevier Science B.V. RP Swartzentruber, BS (reprint author), SANDIA NATL LABS,POB 5800,ALBUQUERQUE,NM 87185, USA. NR 26 TC 12 Z9 12 U1 1 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0039-6028 J9 SURF SCI JI Surf. Sci. PD MAR 10 PY 1997 VL 374 IS 1-3 BP 277 EP 282 DI 10.1016/S0039-6028(96)01199-5 PG 6 WC Chemistry, Physical; Physics, Condensed Matter SC Chemistry; Physics GA WN425 UT WOS:A1997WN42500029 ER PT J AU Peterson, KA Dunning, TH AF Peterson, KA Dunning, TH TI Benchmark calculations with correlated molecular wave functions .8. Bond energies and equilibrium geometries of the CHn and C2Hn (n=1-4) series SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID CONFIGURATION-INTERACTION CALCULATIONS; GAUSSIAN-BASIS SETS; ANHARMONIC-FORCE FIELD; DISSOCIATION ENERGY; PHOTOELECTRON-SPECTROSCOPY; VIBRATIONAL FREQUENCIES; PERTURBATION-THEORY; DIATOMIC HYDRIDES; HF DIMER; ACETYLENE AB Using systematic sequences of correlation consistent basis sets, the accuracy of calculated bond energies D-e(CH) and equilibrium geometries (r(e), theta(e)) has been investigated for the CHn and C2Hn series (n = 1-4). Perturbation theory (MP2, MP3, MP4), coupled cluster [CCSD, CCSD(T)], and single and multireference configuration interaction (HF+1+2, CAS+1+2) methods have been investigated. Except for the vinyl radical, all of the calculated bond energies showed significant basis set dependence with average errors (standard deviations) of 5.6 (+/-3.0) kcal/mol for the cc-pVDZ set, 1.4 (+/-0.8) kcal/mol for the cc-pVTZ set, and 0.5 (+/-0.4) kcal/mol for the cc-pVQZ set with CCSD(T) wave functions. For the vinyl radical the total variation with basis set was just 0.6 kcal/mol. Strong basis set dependence was also observed for the equilibrium geometries, e.g., for r(e)(CH) the average error decreased from 0.020 Angstrom (cc-pVDZ) to 0.003 Angstrom (cc-pVTZ) to 0.002 Angstrom (cc-pVQZ). The effect of including the core electrons in the correlated calculations was also investigated for the two series. Inclusion of core correlation in the CHn series increased D-e(CH) by 0.13 (CH) to 0.61 kcal/mol (CH2) and decreased the equilibrium CH bond lengths by approximately 0.0015 Angstrom. For the C2Hn series, correlation of the core electrons increased D-e(CH) by 0.18 (C2H4) to 1.01 (C2H) kcal/mol, but decreased D-e(CH) in C2H2 by 0.25 kcal/mol. Predictions are also made for the equilibrium geometries of C2H, H2CC, and C2H3, as well as the CH bond strength of vinylidene and the acetylene-vinylidene isomerization energy. (C) 1997 American Institute of Physics. C1 PACIFIC NW LAB, ENVIRONM MOL SCI LAB, RICHLAND, WA 99352 USA. RP Peterson, KA (reprint author), WASHINGTON STATE UNIV, DEPT CHEM, RICHLAND, WA 99352 USA. NR 64 TC 108 Z9 108 U1 0 U2 6 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD MAR 8 PY 1997 VL 106 IS 10 BP 4119 EP 4140 DI 10.1063/1.474078 PG 22 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA WL946 UT WOS:A1997WL94600031 ER PT J AU Jordan, S Eberling, JL Bankiewicz, KS Rosenberg, D Coxson, PG VanBrocklin, HF ONeil, JP Emborg, ME Jagust, WJ AF Jordan, S Eberling, JL Bankiewicz, KS Rosenberg, D Coxson, PG VanBrocklin, HF ONeil, JP Emborg, ME Jagust, WJ TI 6-[F-18]fluoro-L-m-tyrosine: Metabolism, positron emission tomography kinetics, and 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine lesions in primates SO BRAIN RESEARCH LA English DT Article DE positron emission tomography; 6-[F-18]fluoro-L-m-tyrosine; dopamine; kinetics; 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine; monkey; 6-[F-18]fluoro-L-DOPA ID L-DOPA DECARBOXYLASE; HUMAN BRAIN; PARKINSONS-DISEASE; SUBSTANTIA-NIGRA; MONKEYS; MPTP; TURNOVER; NEURONS; ANALOG; TRACER AB The tracer 6-[F-18]fluoro-L-m-tyrosine (FMT) was studied with regard to its biochemistry and kinetics, as well as its utility in evaluating brain dopaminergic function in primates before and after 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) treatment using positron emission tomography (PET). Plasma analysis of FMT and its F18-labeled metabolites 6-fluoro-3-hydroxyphenylacetic acid (FPAC) and 6-fluoro-3-hydroxyphenylethylamine (FMA) during PET scanning enabled kinetic analysis of FMT uptake, A separate study examined brain FMT metabolism in MPTP-naive monkeys euthanized 60 or 120 min after FMT injection. Almost 60% of total plasma F-18 activity was associated with FPAC and FMA 120 min after FMT injection. The FMT signal accumulated preferentially in dopaminergic areas such as caudate and putamen. This bilateral FMT signal was disrupted after unilateral intracarotid artery (ICA) MPTP infusion which reduced ipsilateral striatal activity. A three compartment three kinetic rate constant model for FMT uptake revealed reduced FMT decarboxylation (k(3)) in ipsilateral caudate and putamen after unilateral MPTP although a further decrease was not evident after intravenous MPTP. FPAC was the major F-18 species in all brain regions except in cerebellum where FMT was predominant 60 min post-mortem FPAC was most concentrated in dopaminergic areas whereas lower levels occurred in areas containing few dopamine terminals. These data demonstrate preferential FMT metabolism and F-18 retention in dopaminergic tissue and support the use of FMT to evaluate normal and abnormal dopaminergic function. (C) 1997 Elsevier Science B.V. C1 UNIV CALIF BERKELEY, LAWRENCE BERKELEY LAB, CTR FUNCT IMAGING, BERKELEY, CA 94720 USA. SOMATIX THERAPY CORP, ALAMEDA, CA 94501 USA. UNIV CALIF DAVIS, DEPT NEUROL, DAVIS, CA 95616 USA. NR 51 TC 50 Z9 50 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0006-8993 J9 BRAIN RES JI Brain Res. PD MAR 7 PY 1997 VL 750 IS 1-2 BP 264 EP 276 DI 10.1016/S0006-8993(96)01366-2 PG 13 WC Neurosciences SC Neurosciences & Neurology GA WQ588 UT WOS:A1997WQ58800030 PM 9098552 ER PT J AU Kauffmann, E Frei, H Mathies, RA AF Kauffmann, E Frei, H Mathies, RA TI Nanosecond time-resolved step-scan FT-IR spectroscopy of the photochemical ring-opening of 1,3-cyclohexadiene SO CHEMICAL PHYSICS LETTERS LA English DT Article ID LESS STABLE CONFORMERS; 1,3,5-HEXATRIENE; ISOMERIZATION; ABSORPTION AB Time-resolved step-scan FT-IR spectroscopy with 20 ns resolution has been used to investigate the conformational transformation from cZt-1,3,5-hexatriene to tZt-1,3,5-hexatriene following the photochemical ring opening of 1,3-cyclohexadiene. xadiene. The step-scan FT-IR spectrometer and an IR flow-cell system for performing UV pump, LR probe experiments with 20 ns time resolution are described. At the earliest measurable time points, only features of the final tZt-hexatriene product were observed in the time resolved spectra. Therefore the time constant for this transformation must be faster than 20 ns. C1 UNIV CALIF BERKELEY,DEPT CHEM,BERKELEY,CA 94720. UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,BIOPHYS CHEM LAB,MS CALVIN LAB,BERKELEY,CA 94720. NR 19 TC 19 Z9 19 U1 0 U2 8 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0009-2614 J9 CHEM PHYS LETT JI Chem. Phys. Lett. PD MAR 7 PY 1997 VL 266 IS 5-6 BP 554 EP 559 DI 10.1016/S0009-2614(97)00046-8 PG 6 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA WL836 UT WOS:A1997WL83600025 ER PT J AU Pandey, RK Isaac, M MacDonald, I Medforth, CJ Senge, MO Dougherty, TJ Smith, KM AF Pandey, RK Isaac, M MacDonald, I Medforth, CJ Senge, MO Dougherty, TJ Smith, KM TI Pinacol-pinacolone rearrangements in vic-dihydroxychlorins and bacteriochlorins: Effect of substituents at the peripheral positions SO JOURNAL OF ORGANIC CHEMISTRY LA English DT Article AB Upon reaction with osmium tetraoxide a series of porphyrins and chlorins were converted into the corresponding vic-dihydroxychlorins and bacteriochlorins. The presence of an electron-withdrawing substituent at a peripheral position on the porphyrins or chlorins deactivated that particular pyrrole unit toward oxidation, and also directed the oxidation regioselectively to the pyrrole ring opposite to the one bearing the electronegative group. The vic-dihydroxychlorins and bacteriochlorins were converted into the corresponding oxochlorins and dioxobacteriochlorins under pinacol-pinacolone reaction conditions. The migratory behavior of the various substituents were found to be quite complex, since distant conjugated peripheral substituents were able to affect the stability of the carbocation intermediates during the process; the ability to rearrange was affected not only by the intrinsic nature of the migratory group but also by steric and electronic factors operative elsewhere on the porphyrin and chlorin macrocycles. Preferential migration of the propionic ester over the methyl substituent in dioxobacteriochlorins obtained from 2,3,12,13-tetrahydroxycoproporphyrin II tetramethyl ester (IUPAC nomenclature) under pinacol-pinacolone conditions was confirmed by a single crystal X-ray study. The dioxobacteriochlorins obtained from mesoporphyrin III dimethyl ester and coproporphyrin II tetramethyl ester were converted into the corresponding dithioanalogues using Lawesson's reagent; this caused a red shift of 62 nm (compared with the dioxo compounds) affording long wavelength absorption at lambda(max) 746 nm. C1 NEW YORK STATE DEPT HLTH,ROSWELL PK MEM INST,DEPT RADIAT BIOL,CHEM DIV,DIV RADIAT MED,BUFFALO,NY 14263. FREE UNIV BERLIN,FACHBEREICH CHEM,INST ORGAN CHEM WE02,D-14195 BERLIN,GERMANY. RP Pandey, RK (reprint author), LAWRENCE LIVERMORE NATL LAB,DEPT CHEM,DAVIS,CA 95616, USA. RI Senge, Mathias/F-1504-2011; Medforth, Craig/D-8210-2013; REQUIMTE, FMN/M-5611-2013; REQUIMTE, UCIBIO/N-9846-2013; Smith, Kevin/G-1453-2011 OI Senge, Mathias/0000-0002-7467-1654; Medforth, Craig/0000-0003-3046-4909; Smith, Kevin/0000-0002-6736-4779 NR 27 TC 62 Z9 64 U1 0 U2 6 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0022-3263 J9 J ORG CHEM JI J. Org. Chem. PD MAR 7 PY 1997 VL 62 IS 5 BP 1463 EP 1472 DI 10.1021/jo960720h PG 10 WC Chemistry, Organic SC Chemistry GA WM756 UT WOS:A1997WM75600038 ER PT J AU Falkenstein, Z Coogan, JJ AF Falkenstein, Z Coogan, JJ TI Microdischarge behaviour in the silent discharge of nitrogen-oxygen and water-air mixtures SO JOURNAL OF PHYSICS D-APPLIED PHYSICS LA English DT Article ID DIELECTRIC-BARRIER DISCHARGES AB In this paper measurements of the behaviour of single microdischarges between metal and glass electrodes for both negative and positive polarities of the metal (designated M(-)G(+) and M(+)G(-) transitions, respectively), as well as the overall discharge behaviour between glass electrodes (GG), will be presented for different nitrogen-oxygen and water vapour-air mixtures. Increasing the oxygen concentration in nitrogen decreases the transferred charge per microdischarge for both polarities (M(-)G(+) and M(+)G(-)), while the total transferred charge per cycle is increased. With increasing water content in air, more charge is transferred per microdischarge for the polarity M(+)G(-), but no significant change in the amount of transferred charge was found for a M(-)G(+) microdischarge. Less total charge is transferred per cycle with increasing water content. This is also true for double-dielectric barrier discharges (GG). The results suggest that water vapour coats the dielectric, reducing the surface resistance and increasing the effective dielectric capacity. This mechanism is supported by analysis of the voltage versus charge plot (Lissajous figure) for the involved capacitances of a double-barrier discharge. The reduction of the surface resistance of the dielectric and the resulting increase in the effective dielectric capacitance, are shown by photographs of spatially isolated microdischarges in a metal-pin dielectric arrangement. RP Falkenstein, Z (reprint author), LOS ALAMOS NATL LAB,CHEM SCI & TECHNOL GRP,CST-18,MAILSTOP E 525,LOS ALAMOS,NM 87545, USA. NR 20 TC 211 Z9 221 U1 7 U2 59 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL, ENGLAND BS1 6BE SN 0022-3727 J9 J PHYS D APPL PHYS JI J. Phys. D-Appl. Phys. PD MAR 7 PY 1997 VL 30 IS 5 BP 817 EP 825 DI 10.1088/0022-3727/30/5/015 PG 9 WC Physics, Applied SC Physics GA WP392 UT WOS:A1997WP39200015 ER PT J AU Miller, WH AF Miller, WH TI Quantum and semiclassical Green's functions in chemical reaction dynamics SO JOURNAL OF THE CHEMICAL SOCIETY-FARADAY TRANSACTIONS LA English DT Article ID THERMAL RATE CONSTANTS; FLUX CORRELATION-FUNCTIONS; DISCRETE VARIABLE REPRESENTATION; FROZEN GAUSSIAN APPROXIMATION; ABSORBING BOUNDARY-CONDITIONS; REACTION PROBABILITIES; PATH INTEGRATION; MECHANICAL CALCULATIONS; KETENE ISOMERIZATION; ENERGY-DEPENDENCE AB A variety of quantities related to chemical reaction dynamics (state-selected and cumulative probabilities for chemical reactions, photo-dissociation or -detachment cross-sections, and others) can be expressed compactly (and exactly) in terms of the quantum mechanical Green's function (actually an operator) <(G)over cap (E)> = (E + - (H) over cap)(-1), where (H) over cap is the Hamiltonian for the molecular system and <(epsilon)over cap> an absorbing potential. It is emphasized that these 'formal' quantum expressions can serve as the basis for practical calculations by utilizing a straightforward L(2) matrix representation of the operator (E + - (H) over cap). It is also shown how the semiclassical initial value representation (IVR) can be used to construct approximations for general matrix elements of the Green's function, so that these same formally exact quantum expressions can also be used to provide semiclassical approximations for all of these dynamical quantities. Recent applications of the quantum and semiclassical methodologies are discussed. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV CHEM SCI,BERKELEY,CA 94720. RP Miller, WH (reprint author), UNIV CALIF BERKELEY,DEPT CHEM,BERKELEY,CA 94720, USA. NR 89 TC 22 Z9 22 U1 0 U2 0 PU ROYAL SOC CHEMISTRY PI CAMBRIDGE PA THOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON ROAD, CAMBRIDGE, CAMBS, ENGLAND CB4 4WF SN 0956-5000 J9 J CHEM SOC FARADAY T JI J. Chem. Soc.-Faraday Trans. PD MAR 7 PY 1997 VL 93 IS 5 BP 685 EP 690 DI 10.1039/a606858h PG 6 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA WP012 UT WOS:A1997WP01200003 ER PT J AU Althorpe, SC Kouri, DJ Hoffman, DK Zhang, JZH AF Althorpe, SC Kouri, DJ Hoffman, DK Zhang, JZH TI Reactant-product decoupling approach to state-resolved reactive scattering - Time-independent wavepacket formulation SO JOURNAL OF THE CHEMICAL SOCIETY-FARADAY TRANSACTIONS LA English DT Article ID LIPPMANN-SCHWINGER EQUATIONS; APPROXIMATING FUNCTION-APPROACH; ABSORBING BOUNDARY-CONDITIONS; POTENTIAL-ENERGY SURFACE; WAVE PACKET APPROACH; REACTION PROBABILITIES; QUANTUM CALCULATIONS; CROSS-SECTIONS; SCHRODINGER; COLLISIONS AB Recently a formalism has been derived that rigorously partitions the time-dependent wavepacket for a reactive scattering system into mutually disjoint pieces satisfying uncoupled equations. Equations are set up for the time-evolution of the various arrangement pieces of the wavepacket by using absorbing potentials to decouple the initial arrangement dynamics from the other arrangements, and emitting potentials to provide sources for the scattering in each product arrangement. Here, we present the time-independent wavepacket equations that result from this reactant-product decoupling and illustrate their solution with an example calculation on collinear H + H-2. C1 UNIV HOUSTON,DEPT PHYS,HOUSTON,TX 77204. IOWA STATE UNIV SCI & TECHNOL,DEPT CHEM,AMES,IA 50011. IOWA STATE UNIV SCI & TECHNOL,AMES LAB,AMES,IA 50011. NYU,DEPT CHEM,NEW YORK,NY 10003. RP Althorpe, SC (reprint author), UNIV HOUSTON,DEPT CHEM,UNIV PK,HOUSTON,TX 77204, USA. RI Zhang, John/A-3372-2013 NR 50 TC 14 Z9 14 U1 0 U2 7 PU ROYAL SOC CHEMISTRY PI CAMBRIDGE PA THOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON ROAD, CAMBRIDGE, CAMBS, ENGLAND CB4 4WF SN 0956-5000 J9 J CHEM SOC FARADAY T JI J. Chem. Soc.-Faraday Trans. PD MAR 7 PY 1997 VL 93 IS 5 BP 703 EP 708 DI 10.1039/a606300d PG 6 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA WP012 UT WOS:A1997WP01200006 ER PT J AU Maierle, CS Schatz, GC Gordon, MS McCabe, P Connor, JNL AF Maierle, CS Schatz, GC Gordon, MS McCabe, P Connor, JNL TI Coupled potential-energy surfaces and quantum reactive scattering for the Cl(P-2)+HCl->ClH+Cl(P-2) reaction SO JOURNAL OF THE CHEMICAL SOCIETY-FARADAY TRANSACTIONS LA English DT Article ID ELECTRONICALLY NONADIABATIC REACTION; TRANSFER-REACTION CL+HCL->CLH+CL; OSCILLATING REACTIVITY; BORN-OPPENHEIMER; SPIN-ORBIT; MOLECULAR-COLLISIONS; COLLINEAR REACTIONS; ANGULAR SCATTERING; STATIONARY-POINTS; CROSS-SECTIONS AB We construct global multiple-coupled potential-energy surfaces for the three-dimensional Cl(P-2) + HCl --> ClH + Cl(P-2) reaction which we use to generate results from quantum reactive scattering calculations. The three potential surfaces (1 (2)A', 2(2)A' and 1 (2)A '') are derived from multi-configuration self-consistent held (MCSCF) electronic structure calculations for geometries where all atoms are strongly interacting. The MCSCF energies are used to construct diabatic potentials which are fitted with rotated Morse cubic spline functions. The diabatic surfaces are then combined with empirical long-range potentials due to Dubernet and Hutson, which are also used to determine empirical coupling surfaces. Spin-orbit interaction is added perturbatively to the resulting surfaces. Saddle-point properties on these fitted surfaces are scaled to reproduce experimental thermal rate coefficient data based on the quantum scattering calculations. The quantum scattering calculations are based on a coupled-channel hyperspherical coordinate (CCH) method. The basis expansion used in the scattering calculation contains diatomic vibration and rotation, and the atomic fine-structure states, including full angular momentum coupling of rotation with electronic spin and orbital angular momentum. All terms in the combined rovibronic Hamiltonian are evaluated explicitly, including spin-orbit coupling, Coriolis and electrostatic interactions. State-selected and total cumulative reaction probabilities and thermal rate coefficients are calculated using a J-shifting approximation, which starts from converged CCH results for total angular momentum quantum number J = 1/2. The calculated rate coefficients indicate that spin-state change collisions account for a few per cent of the thermal rate coefficient at 300 K. Transition-state CIHCI resonances are lower in energy and broader than those on earlier (single) surfaces, and there is a more extensive progression in the symmetric stretch mode. C1 NORTHWESTERN UNIV,DEPT CHEM,EVANSTON,IL 60208. IOWA STATE UNIV SCI & TECHNOL,AMES LAB,DEPT CHEM,AMES,IA 50011. UNIV MANCHESTER,DEPT CHEM,MANCHESTER M13 9PL,LANCS,ENGLAND. RI McCabe, Patrick/M-3718-2013 OI McCabe, Patrick/0000-0003-2538-4920 NR 77 TC 67 Z9 67 U1 0 U2 8 PU ROYAL SOC CHEMISTRY PI CAMBRIDGE PA THOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON ROAD, CAMBRIDGE, CAMBS, ENGLAND CB4 4WF SN 0956-5000 J9 J CHEM SOC FARADAY T JI J. Chem. Soc.-Faraday Trans. PD MAR 7 PY 1997 VL 93 IS 5 BP 709 EP 720 DI 10.1039/a606570h PG 12 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA WP012 UT WOS:A1997WP01200007 ER PT J AU Neuhauser, D Judson, RS Baer, M Kouri, DJ AF Neuhauser, D Judson, RS Baer, M Kouri, DJ TI State-to-state time-dependent wavepacket approach to reactive scattering: State-resolved cross-sections for D+H-2(v=1, j=1,m)->H+DH((v)over-bar,(j)over-bar) SO JOURNAL OF THE CHEMICAL SOCIETY-FARADAY TRANSACTIONS LA English DT Article ID WAVE PACKET APPROACH; LIPPMANN-SCHWINGER EQUATIONS; REACTION PROBABILITIES; ABSORBING POTENTIALS; QUANTUM DYNAMICS; ROTATIONAL-EXCITATION; RATE CONSTANTS; 3 DIMENSIONS; COLLISIONS; SYSTEMS AB In a recent letter (Science, 1992, 257, 522) the time-dependent wavepacket approach to reactive-scattering was utilized to extract state-to-state scattering cross-sections for D + H-2(v, j) --> H + at high energies. Results from 1.3 up to 2.25 eV total energy, with a fine enough grid to enable appropriate averages simulating the experimental conditions, are reported. We briefly review the formalism used for the simulations and explain how coordinate grid-reduction techniques concentrate the numerical effort in a small, strong interaction region, enabling calculations of state-resolved cross-sections for this demanding reaction. We then study the results in more detail by examining their variation with collision energy, final rotational state, and the individual initial H-2 magnetic quantum number (measured along the incident linear momentum of the D atom relative to the H-2 centre-of-mass). C1 UNIV CALIF LOS ANGELES,DEPT CHEM & BIOCHEM,LOS ANGELES,CA 90024. SANDIA NATL LABS,DEPT COMP SCI,LIVERMORE,CA 94551. SOREQ NUCL RES CTR,DEPT PHYS & APPL MATH,IL-81800 YAVNE,ISRAEL. UNIV HOUSTON,DEPT CHEM,HOUSTON,TX 77204. UNIV HOUSTON,DEPT PHYS,HOUSTON,TX 77204. NR 79 TC 5 Z9 5 U1 0 U2 2 PU ROYAL SOC CHEMISTRY PI CAMBRIDGE PA THOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON ROAD, CAMBRIDGE, CAMBS, ENGLAND CB4 4WF SN 0956-5000 J9 J CHEM SOC FARADAY T JI J. Chem. Soc.-Faraday Trans. PD MAR 7 PY 1997 VL 93 IS 5 BP 727 EP 736 PG 10 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA WP012 UT WOS:A1997WP01200009 ER PT J AU Wang, HB Goldfield, EM Hase, WL AF Wang, HB Goldfield, EM Hase, WL TI Quantum dynamical study of the Cl-+CH3Br S(N)2 reaction SO JOURNAL OF THE CHEMICAL SOCIETY-FARADAY TRANSACTIONS LA English DT Review ID SN2 NUCLEOPHILIC-SUBSTITUTION; DISCRETE VARIABLE REPRESENTATION; TRANSITION-STATE-THEORY; CUMULATIVE REACTION PROBABILITY; DEPENDENT SCHRODINGER-EQUATION; MINIMAL RESIDUAL ALGORITHM; POTENTIAL-ENERGY SURFACE; ATOM-DIATOM COLLISIONS; WAVE PACKET FORMALISM; GAS-PHASE AB Reduced dimensional time-dependent and time-independent quantum dynamics calculations are performed for the Cl- + CH3Br S(N)2 reaction. In the time-dependent study, a wavepacket is initiated at the Cl-... CH3Br pre-reaction complex to study its unimolecular dynamics. A large portion of the wavepacket is trapped in the pre- and post-reaction complexes for a time substantially longer than that predicted by RRKM theory. Many resonance states are seen in the power spectrum of the wavepacket's time autocorrelation function. In the time-independent study, the cumulative reaction probability for Cl-... CH3Br --> ClCH3 ... Br- isomerization is obtained. It is found to be much smaller than the statistical number of states/flux at the central barrier, suggesting that dynamics effects are important. A reduced dimensionality approach, appropriate for a complex reaction, is used to extract the full dimensional Cl- + CH3Br --> ClCH3 + Br- bimolecular substitution rate constant from the reduced dimensional quantum dynamics calculation. For the model Hamiltonian used here, this quantum dynamics rate constant is in much better agreement with experiment than that of statistical theory. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV CHEM SCI,BERKELEY,CA 94720. RP Wang, HB (reprint author), UNIV CALIF BERKELEY,DEPT CHEM,BERKELEY,CA 94720, USA. RI Wang, Haobin/E-1208-2011 NR 102 TC 42 Z9 42 U1 3 U2 6 PU ROYAL SOC CHEMISTRY PI CAMBRIDGE PA THOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON ROAD, CAMBRIDGE, CAMBS, ENGLAND CB4 4WF SN 0956-5000 J9 J CHEM SOC FARADAY T JI J. Chem. Soc.-Faraday Trans. PD MAR 7 PY 1997 VL 93 IS 5 BP 737 EP 746 DI 10.1039/a606061g PG 10 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA WP012 UT WOS:A1997WP01200010 ER PT J AU Goldfield, EM Gray, SK AF Goldfield, EM Gray, SK TI Total angular momentum and decay of unimolecular resonances - IVR-mediated vibrational predissociation SO JOURNAL OF THE CHEMICAL SOCIETY-FARADAY TRANSACTIONS LA English DT Article ID VANDERWAALS MOLECULES; QUANTUM DYNAMICS; DISSOCIATION; REDISTRIBUTION; RELAXATION; SCATTERING; EQUATION; ENERGY; IODINE; I-2-AR AB Full-dimensional wavepacket calculations are carried out on the vibrational predissociation of ArI2. With the aid of a parallel computing strategy, we consider systems with total angular momentum quantum numbers up to J = 24. Previous work for low J has shown that fragmentation occurs via a sparse limit intramolecular vibrational energy redistribution mechanism involving passage through a few intermediate dark states. Despite many more states becoming available as J is increased, this mechanism continues to dominate. Inspection of wavepacket densities and characterization of the dark states helps explain why the mechanism persists with increasing J. C1 ARGONNE NATL LAB,DIV CHEM,ARGONNE,IL 60439. RP Goldfield, EM (reprint author), WAYNE STATE UNIV,DEPT CHEM,DETROIT,MI 48202, USA. NR 36 TC 22 Z9 22 U1 0 U2 0 PU ROYAL SOC CHEMISTRY PI CAMBRIDGE PA THOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON ROAD, CAMBRIDGE, CAMBS, ENGLAND CB4 4WF SN 0956-5000 J9 J CHEM SOC FARADAY T JI J. Chem. Soc.-Faraday Trans. PD MAR 7 PY 1997 VL 93 IS 5 BP 909 EP 918 DI 10.1039/a606041b PG 10 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA WP012 UT WOS:A1997WP01200031 ER PT J AU McRae, RP Schenter, GK Garrett, BC AF McRae, RP Schenter, GK Garrett, BC TI Dynamic solvent effects on activated chemical reactions .2. Quantum mechanical effects SO JOURNAL OF THE CHEMICAL SOCIETY-FARADAY TRANSACTIONS LA English DT Article ID TRANSITION-STATE-THEORY; ATOM TRANSFER-REACTIONS; THERMAL RATE CONSTANTS; FLUX AUTOCORRELATION FUNCTION; DISSIPATIVE SYSTEMS; BENCHMARK CALCULATIONS; POLYATOMIC-MOLECULES; COLLINEAR REACTIONS; HYDROGEN MOLECULES; RATE COEFFICIENTS AB The treatment of dynamic solvent effects using variational transition state theory is extended to include quantum effects in an approximate manner. The resulting theory is then applied to the same model system as in Part I for a reaction in solution, namely a collinear model of a triatomic atom-transfer reaction in which the dynamic solvent effects are those of the solvent friction described by a generalized Langevin equation. It is found that dynamic solvent effects on reaction rate constants can be greatly enhanced when quantum mechanical effects are included. Treatment of the reaction model using a classical mechanical theory such as classical variational transition state theory or Grote-Hynes theory typically leads to the solvent friction decreasing the rate constant by factors less than 10. Over the same range of model parameters, the quantum mechanical variational transition-state theory shows decreases as large as several orders of magnitude. C1 EASTERN WASHINGTON UNIV, DEPT CHEM & BIOCHEM, CHENEY, WA 99004 USA. PACIFIC NW LAB, ENVIRONM MOL SCI LAB, RICHLAND, WA 99352 USA. RI Garrett, Bruce/F-8516-2011; Schenter, Gregory/I-7655-2014 OI Schenter, Gregory/0000-0001-5444-5484 NR 98 TC 7 Z9 7 U1 3 U2 4 PU ROYAL SOC CHEMISTRY PI CAMBRIDGE PA THOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON ROAD, CAMBRIDGE, CAMBS, ENGLAND CB4 4WF SN 0956-5000 J9 J CHEM SOC FARADAY T JI J. Chem. Soc.-Faraday Trans. PD MAR 7 PY 1997 VL 93 IS 5 BP 997 EP 1009 DI 10.1039/a605914g PG 13 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA WP012 UT WOS:A1997WP01200040 ER PT J AU Keister, JW Baer, T Evans, M Ng, CY Hsu, CW AF Keister, JW Baer, T Evans, M Ng, CY Hsu, CW TI Methyl loss kinetics of energy-selected 1,3-butadiene and methylcyclopropene cations SO JOURNAL OF PHYSICAL CHEMISTRY A LA English DT Article ID MULTIPHOTON IONIZATION; UNIMOLECULAR REACTIONS; SYSTEM; RATES; PHOTOIONIZATION; IONS AB The kinetics of the metastable dissociation of energy-selected 1,3-butadiene and 3-methylcyclopropene cations to form C3H3+ (cyclopropenyl cation) and CH3 have been investigated by threshold photoelectron photoion coincidence (TPEPICO) time-of-flight mass spectrometry, ab initio molecular orbital calculations, and RRKM statistical theory. Both the experimental results and the molecular orbital calculations indicate that 1,3-butadiene ions lose CH3 by first isomerizing to a higher energy structure (3-methylcyclopropene cation) which can rapidly lose CH3 or isomerize back to the 1,3-butadiene cation. A complete kinetic model of the two-well potential and its three rate constants is necessary to account for the measured dissociation rates as a function of the ion internal energy. At low energies, the dissociation rate is limited by the bond cleavage step, while at higher energies, the bottleneck shifts to the lower energy isomerization step. a fit of calculated RRKM rate constants to the experimental data yields a 0 K isomerization barrier (relative to the 1,3-butadiene ion) of 2.02 +/- 0.03 eV and an activation entropy at 600 K of -4 cal K-1 mol(-1). The entropy of activation for the dissociation step from 3-methylcyclopropene was found to be +7 cal K-1 mol(-1). 3-Methylcyclopropene was found to have an adiabatic ionization energy of 9.28 +/- 0.05 eV and a neutral heat of formation of 273 +/- 2 kJ mol(-1) at 0 K (257 +/- 2 kJ mol(-1) at 298 K). This is the first experimental determination of this value. C1 UNIV N CAROLINA,WILLIAM RAND KENAN JR LABS CHEM,CHAPEL HILL,NC 27599. US DOE,AMES LAB,AMES,IA 50011. IOWA STATE UNIV,DEPT CHEM,AMES,IA 50011. UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV CHEM SCI,BERKELEY,CA 94720. NR 32 TC 20 Z9 20 U1 0 U2 4 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 1089-5639 J9 J PHYS CHEM A JI J. Phys. Chem. A PD MAR 6 PY 1997 VL 101 IS 10 BP 1866 EP 1872 DI 10.1021/jp9629001 PG 7 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA WL769 UT WOS:A1997WL76900014 ER PT J AU Pilgrim, JS McIlroy, A Taatjes, CA AF Pilgrim, JS McIlroy, A Taatjes, CA TI Kinetics of Cl atom reactions with methane, ethane, and propane from 292 to 800 K SO JOURNAL OF PHYSICAL CHEMISTRY A LA English DT Article ID GAS-PHASE REACTION; THERMAL-DECOMPOSITION; CHLORINE ATOMS; RATE CONSTANTS; CL ATOMS; ATMOSPHERIC-PRESSURE; SIMPLE ALKANES; ABSOLUTE RATE; SPECTROSCOPY; COEFFICIENTS AB Absolute rate coefficients for the reactions of chlorine atom with methane and ethane between 292 and 800 K and with propane between 292 and 700 K have been determined using the laser photolysis/continuous wave infrared long-path absorption method, LP/cwIRLPA. A novel reactor design and optical arrangement allow long absorption paths with precise control of the temperature in the probed volume. The rate coefficient for methane exhibits significant curvature between 292 and 800 K and can be described over this temperature range by a modified Arrhenius expression, k(CH4)(T) = [3.7((-2.5) (+8.2)) x 10(-13) cm(3) molecule(-1) s(-1)](T/298)(2.6(+/-0.7)) exp[-385(+/-320)/T] (all error bars are +/-2 sigma precision only). In the temperature range 292-600 K the rate with ethane agrees well with earlier investigations, fitting a simple Arrhenius expression k(C2H6)(T) = 8.6(+/-0.5) x 10(-11) exp[-135(+/-26)/T] cm(3) molecule(-1) s(-1). However, as the temperature increases beyond 600 K the Arrhenius plot exhibits significant upward curvature. Over the range 292-800 K a three-parameter Arrhenius fit, k(C2H6)(T) = 3.4(+/-1.4) x 10(-11) (T/298)(0.7(+/-0.3)) exp[150(+/-110)/T] cm(3) molecule(-1) s(-1), models the experimental data adequately. The rate coefficient for propane is found to be independent of temperature and equal to 1.38(+/-0.03) x 10(-10) cm(3) molecule(-1) s(-1). C1 SANDIA NATL LABS,COMBUST RES FACIL,LIVERMORE,CA 94551. NR 41 TC 88 Z9 88 U1 1 U2 8 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 1089-5639 J9 J PHYS CHEM A JI J. Phys. Chem. A PD MAR 6 PY 1997 VL 101 IS 10 BP 1873 EP 1880 DI 10.1021/jp962916r PG 8 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA WL769 UT WOS:A1997WL76900015 ER PT J AU Thiesemann, H MacNamara, J Taatjes, CA AF Thiesemann, H MacNamara, J Taatjes, CA TI Deuterium kinetic isotope effect and temperature dependence in the reactions of CH[(2)Pi] with methane and acetylene SO JOURNAL OF PHYSICAL CHEMISTRY A LA English DT Article ID TRANSITION-STATE THEORY; HINDERED ROTOR MODEL; RATE CONSTANTS; ASSOCIATION REACTIONS; RADICAL REACTIONS; CH; MECHANISMS; PRESSURE AB The rate coefficients of the reactions of CH and CD with CH4, CD4, C2H2, and C2D2 have been measured in the temperature range 290 < T < 700 K. All the rate constants show a slightly negative temperature dependence. They can be fitted in the observed temperature range by the following expressions: k(CH+CH4) = (6.7+/-0.3)(T/293 K)(-(0.4+/-0.1)) x 10(-11) cm(3) molecule(-1) s(-1); k(CH+CD4) = (4.2+/-0.2)(T/293 K)(-(0.3+/-0.1)) x 10(-11) cm(3) molecule(-1) s(-1); k(CD+CH4) = (5.7+/-0.2)(T/293 K)(-(0.32+/-0.04)) x 10(-11) cm(3) molecule(-1) s(-1); k(CD+CD4) = (3.6+/-0.1)(T/293 K)(-(0.27+/-0.08)) x 10(-11) cm(3) molecule(-1) s(-1); k(CH+C2H2) = (3.2+/-0.2)(T/293 K)(-(0.2+/-0.1)) x 10(-10) cm(3) molecule(-1) s(-1); k(CD+C2H2) = (2.8+/-0.1)(T/293 K)(-(0.13+/-0.06)) x 10(-10) cm(3) molecule(-1) s(-1); k(CH+C2D2) = (3.2+/-0.2)(T/293 K)(-(0.2+/-0.1)) x 10(-10) cm(3) molecule(-1) s(-1); and k(CD+C2D2) = (2.8+/-0.2)(T/293 K)(-(0.2+/-0.1)) x 10(-10) cm(3) molecule(-1) s(-1), where all error estimates are +/-2 sigma and represent the precision of the fit. The observed temperature and pressure dependences are in accordance with a barrierless addition of the methylidyne radical to methane or acetylene with rapid decomposition of the adduct. The deuterium isotope effects on the reactions are not well-described by loose-transition state models and may reflect changes in the vibrational frequencies in the transition state for initial complex formation. C1 SANDIA NATL LABS,COMBUST RES FACIL,LIVERMORE,CA 94551. NATL UNIV IRELAND UNIV COLL GALWAY,DEPT CHEM,GALWAY,IRELAND. NR 34 TC 33 Z9 33 U1 0 U2 6 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 1089-5639 J9 J PHYS CHEM A JI J. Phys. Chem. A PD MAR 6 PY 1997 VL 101 IS 10 BP 1881 EP 1886 DI 10.1021/jp9630333 PG 6 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA WL769 UT WOS:A1997WL76900016 ER PT J AU Hu, SL Reimer, JA Bell, AT AF Hu, SL Reimer, JA Bell, AT TI Cu-65 NMR spectroscopy of Cu-exchanged ZSM-5 catalysts SO JOURNAL OF PHYSICAL CHEMISTRY B LA English DT Article ID NO DECOMPOSITION; ZEOLITES; CU-ZSM-5; PHOTOLUMINESCENCE; STATE; IONS; IR AB Cu-65 NMR and Cu-65-Al-27 spin-echo, double-resonance (SEDOR) measurements from Cu-exchanged ZSM-5 catalysts are reported. The presence of Cu+ cations in CuZSM-5 was detected directly by Cu-65 NMR; upon heating, we observed the autoreduction of Cu2+ to Cu+. It was found that the Cu+ cations can be reduced further to Cu-0 by exposure to carbon monoxide at high temperatures. The internuclear distance between the two quadrupolar nuclei Cu (spin-3/2) and Al (spin-5/2) was determined to be 0.23 +/- 0.02 nm, in good agreement with the value of 0.24 nm obtained from density functional theory calculations. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,CTR ADV MAT,BERKELEY,CA 94720. UNIV CALIF BERKELEY,DEPT CHEM ENGN,BERKELEY,CA 94720. NR 24 TC 28 Z9 29 U1 2 U2 6 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 1089-5647 J9 J PHYS CHEM B JI J. Phys. Chem. B PD MAR 6 PY 1997 VL 101 IS 10 BP 1869 EP 1871 DI 10.1021/jp9630380 PG 3 WC Chemistry, Physical SC Chemistry GA WL767 UT WOS:A1997WL76700024 ER PT J AU Krumholz, LR McKinley, JP Ulrich, FA Suflita, JM AF Krumholz, LR McKinley, JP Ulrich, FA Suflita, JM TI Confined subsurface microbial communities in Cretaceous rock SO NATURE LA English DT Article ID SEDIMENTS; WATER AB Deep subsurface microbial communities(1) are believed to be supported by organic matter that was either deposited with the formation sediments or which migrated from the surface along groundwater flowpaths. Investigation has therefore focused on the existence of microorganisms in recently deposited or highly permeable sediments(2,3). Fewer reports have focused on consolidated rocks(4-7). These findings have often been limited by inadequate tracer methodology or non-sterile sampling techniques. Here we present evidence for the presence of spatially discrete microbial communities in Cretaceous rocks and advance a mechanism for the long-term survival of these subterranean communities. Samples were collected using aseptic methods and sensitive tracers(8). Our results indicate that the main energy source for these communities is organic material trapped within shales. Microbial activity in shales appears to be greatly reduced, presumably because of their restrictive pore size(9). However, organic material or its fermentation products could diffuse into adjacent, more permeable sandstones, where microbial activity was much more abundant, This process resulted in the presence of microbial communities at sandstone-shale interfaces. These microorganisms presumably ferment organic matter and carry out sulphate reduction and acetogenesis. C1 PACIFIC NW LAB, RICHLAND, WA 99352 USA. RP Krumholz, LR (reprint author), UNIV OKLAHOMA, DEPT BOT & MICROBIOL, 770 VAN VLEET OVAL, NORMAN, OK 73019 USA. NR 19 TC 153 Z9 156 U1 2 U2 71 PU MACMILLAN MAGAZINES LTD PI LONDON PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW SN 0028-0836 J9 NATURE JI Nature PD MAR 6 PY 1997 VL 386 IS 6620 BP 64 EP 66 DI 10.1038/386064a0 PG 3 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA WL746 UT WOS:A1997WL74600050 ER PT J AU Carlson, CE MolinaParis, C PerezMercader, J Visser, M AF Carlson, CE MolinaParis, C PerezMercader, J Visser, M TI Schwinger's dynamical Casimir effect: Bulk energy contribution SO PHYSICS LETTERS B LA English DT Article ID LIGHT AB Schwinger's Dynamical Casimir Effect is one of several candidate explanations for sonoluminescence. Recently, several papers have claimed that Schwinger's estimate of the Casimir energy involved is grossly inaccurate, In this letter, we show that these calculations omit the crucial volume term. When the missing term is correctly included one finds full agreement with Schwinger's result for the Dynamical Casimir Effect. We have nothing new to say about sonoluminescence itself except to affirm that the Casimir effect is energetically adequate as a candidate explanation. C1 LOS ALAMOS NATL LAB,DIV THEORET,LOS ALAMOS,NM 87545. LAB ASTROFIS ESPACIAL & FIS FUNDAMENTAL,MADRID 28080,SPAIN. WASHINGTON UNIV,DEPT PHYS,ST LOUIS,MO 63130. RP Carlson, CE (reprint author), COLL WILLIAM & MARY,DEPT PHYS,WILLIAMSBURG,VA 23187, USA. OI Visser, Matt/0000-0003-1088-6485 NR 8 TC 20 Z9 20 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0370-2693 J9 PHYS LETT B JI Phys. Lett. B PD MAR 6 PY 1997 VL 395 IS 1-2 BP 76 EP 82 DI 10.1016/S0370-2693(97)00009-9 PG 7 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA WM562 UT WOS:A1997WM56200013 ER PT J AU Barton, JW Ford, RM AF Barton, JW Ford, RM TI Mathematical model for characterization of bacterial migration through sand cores SO BIOTECHNOLOGY AND BIOENGINEERING LA English DT Article DE bacterial chemotaxis; Escherichia coli; random motility; mathematical model; sand core; porous media ID CHEMOTACTIC CELL-POPULATIONS; ATTRACTANT GRADIENTS; PSEUDOMONAS-PUTIDA; ESCHERICHIA-COLI; POROUS-MEDIA; TRANSPORT; COEFFICIENTS; TRANSDUCTION; MECHANISMS; MOTILITY AB The migration of chemotactic bacteria in liquid media has previously been characterized in terms of two fundamental transport coefficients-the random motility coefficient and the chemotactic sensitivity coefficient. For modeling migration in porous media, we have shown that these coefficients which appear in macroscopic balance equations can be replaced by effective values that reflect the impact of the porous media on the swimming behavior of individual bacteria. Explicit relationships between values of the coefficients in porous and liquid media were derived. This type of quantitative analysis of bacterial migration is necessary for predicting bacterial population distributions in subsurface environments for applications such as in situ bioremediation in which bacteria respond chemotactically to the pollutants that they degrade. We analyzed bacterial penetration times through sand columns from two different experimental studies reported in the literature within the context of our mathematical model to evaluate the effective transport coefficients. Our results indicated that the presence of the porous medium reduced the random motility of the bacterial population by a factor comparable to the theoretical prediction. We were unable to determine the effect of the porous medium on the chemotactic sensitivity coefficient because no chemotactic response was observed in the experimental studies. However, the mathematical model was instrumental in developing a plausible explanation for why no chemotactic response was observed. The chemical gradients may have been too shallow over most of the sand core to elicit a measurable response. (C) 1997 John Wiley & Sons, Inc. C1 OAK RIDGE NATL LAB, DIV CHEM TECHNOL, OAK RIDGE, TN 37831 USA. RP Barton, JW (reprint author), UNIV VIRGINIA, DEPT CHEM ENGN, THORNTON HALL, CHARLOTTESVILLE, VA 22903 USA. NR 32 TC 34 Z9 34 U1 1 U2 9 PU WILEY-BLACKWELL PI HOBOKEN PA 111 RIVER ST, HOBOKEN 07030-5774, NJ USA SN 0006-3592 EI 1097-0290 J9 BIOTECHNOL BIOENG JI Biotechnol. Bioeng. PD MAR 5 PY 1997 VL 53 IS 5 BP 487 EP 496 PG 10 WC Biotechnology & Applied Microbiology SC Biotechnology & Applied Microbiology GA WL035 UT WOS:A1997WL03500006 PM 18634044 ER PT J AU Young, DM Unkefer, PJ Ogden, KL AF Young, DM Unkefer, PJ Ogden, KL TI Biotransformation of hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) by a prospective consortium and its most effective isolate Serratia marcescens SO BIOTECHNOLOGY AND BIOENGINEERING LA English DT Article DE RDX (hexahydro-l,3,5-trinitro-l,3,5-triazine; Serratia marcescens; biotransformation AB The biotransformation of hexahydro-1,3,5-trinitro-1,3,5 triazine (RDX) has been observed in liquid culture by a consortium of bacteria found in horse manure. Five types of bacteria were found to predominate in the consortium and were isolated. The most effective of these isolates at transforming RDX was Serratia marcescens. The biotransformation of RDX by all of these bacteria was found to occur only in the anoxic stationary phase. The process of bacterial growth and RDX biotransformation was quantified for the purpose of developing a predictive type model. Cell growth was assumed to follow Monod kinetics. All of the aerobic and anoxic growth parameters were determined: mu(max), K-s, and Y-x/s, RDX was found to competitively inhibit cell growth in both atmospheres. Degradation of RDX by Serratia marcescens was found to proceed through the stepwise reduction of the three nitro groups to nitroso groups. Each of these reductions was found to be first order in both component and cell concentrations. The degradation rate constant for the first step in this reduction process by the consortium was 0.022 L/g cells . h compared to 0.033 L/g cells . h for the most efficient isolate. (C) 1997 John Wiley & Sons, Inc. C1 UNIV ARIZONA, DEPT ENVIRONM CHEM & ENGN, TUCSON, AZ 85721 USA. LOS ALAMOS NATL LAB, DIV CHEM SCI & TECHNOL, LOS ALAMOS, NM 87545 USA. NR 11 TC 77 Z9 77 U1 0 U2 2 PU WILEY-BLACKWELL PI MALDEN PA COMMERCE PLACE, 350 MAIN ST, MALDEN 02148, MA USA SN 0006-3592 J9 BIOTECHNOL BIOENG JI Biotechnol. Bioeng. PD MAR 5 PY 1997 VL 53 IS 5 BP 515 EP 522 PG 8 WC Biotechnology & Applied Microbiology SC Biotechnology & Applied Microbiology GA WL035 UT WOS:A1997WL03500009 PM 18634047 ER PT J AU Lin, WB Lee, TL Lyman, PF Lee, JJ Bedzyk, MJ Marks, TJ AF Lin, WB Lee, TL Lyman, PF Lee, JJ Bedzyk, MJ Marks, TJ TI Atomic resolution X-ray standing wave microstructural characterization of NLO-active self-assembled chromophoric superlattices SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Article ID NONLINEAR-OPTICAL-MATERIALS; MULTILAYER THIN-FILMS; FORCE MICROSCOPY; GOLD SURFACES; 2ND-HARMONIC GENERATION; MOLECULAR ASSEMBLIES; ORGANIC DISULFIDES; MONOLAYER FILM; GROWTH; ELLIPSOMETRY AB This contribution reports the first X-ray standing wave structural characterization of self-assembled NLO-active chromophoric multilayers (SAMs). These siloxane-based self-assembled stilbazolium multilayers are intrinsically acentric and exhibit very large second-order nonlinear optical responses. The locations of bromide ions within the SAMs were precisely determined using X-ray standing waves generated by total external reflection from mirror surfaces as well as by Bragg diffraction from layered synthetic microstructures. The large coherent fraction (i.e., small Gaussian distribution width) of the Br- ions provides direct evidence for the high structural regularity of these self-assembled multilayers along the surface normal direction. These results are supported by atomic force microscopic (AFM) and X-ray photoelectron spectroscopic (XPS) studies which probe the structural regularity and chemical composition of SAMs, respectively. The anion surface coverage has also been measured in this study (2.5(5) x 10(14) Br-/cm(2)) and is in excellent agreement with the cation surface coverage measured by second harmonic generation (2(1) x 10(14) molecules/cm(2)). These results clearly demonstrate the utility of X-ray standing wave analyses as a quantitative microstructural probe for self-assembled mono- and multilayers, especially for SAMs with incommensurate structures. C1 NORTHWESTERN UNIV,DEPT CHEM,EVANSTON,IL 60208. NORTHWESTERN UNIV,DEPT MAT SCI,EVANSTON,IL 60208. NORTHWESTERN UNIV,DEPT PHYS & ASTRON,EVANSTON,IL 60208. NORTHWESTERN UNIV,MAT RES CTR,EVANSTON,IL 60208. ARGONNE NATL LAB,DIV MAT SCI,ARGONNE,IL 60439. RI Bedzyk, Michael/B-7503-2009; Lin, Wenbin/B-4151-2010; Bedzyk, Michael/K-6903-2013 OI Lin, Wenbin/0000-0001-7035-7759; NR 52 TC 43 Z9 44 U1 0 U2 6 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0002-7863 J9 J AM CHEM SOC JI J. Am. Chem. Soc. PD MAR 5 PY 1997 VL 119 IS 9 BP 2205 EP 2211 DI 10.1021/ja962293v PG 7 WC Chemistry, Multidisciplinary SC Chemistry GA WL646 UT WOS:A1997WL64600019 ER PT J AU Pyda, M Guiochon, G AF Pyda, M Guiochon, G TI Surface properties of silica-based adsorbents measured by inverse gas-solid chromatography at finite concentration SO LANGMUIR LA English DT Article; Proceedings Paper CT 2nd International Symposium on Effects of Surface Heterogeneity in Adsorption and Catalysis on Solids CY SEP 04-10, 1995 CL HIGH TETRA MT, POLAND ID ADSORPTION ENERGY-DISTRIBUTIONS; ISOTHERM DATA; ACCURACY; PRECISION; ELUTION AB The adsorption energy distributions (AEDs) of methanol and dichloromethane on samples of the same silica unmodified and modified with octadecyldimethylsilyl (C-18) were estimated from isotherm data obtained by inverse gas chromatography at finite concentration. Wall-coated open tubular columns were used as they provide a high efficiency and a low pressure drop, allowing the acquisition of accurate isotherm data. The adsorption isotherms were obtained from nonlinear elution profiles using the characteristic points method of chromatography. The numerical estimation of AEDs was made by applying the expectation-maximization method to the experimental, unfitted adsorption isotherm data. The adsorption energy distributions obtained exhibit two peaks of adsorption energy. The height of the higher energy peak is reduced after chemical modification of the silica surface. C1 UNIV TENNESSEE,DEPT CHEM,KNOXVILLE,TN 37996. OAK RIDGE NATL LAB,OAK RIDGE,TN 37831. NR 18 TC 12 Z9 12 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0743-7463 J9 LANGMUIR JI Langmuir PD MAR 5 PY 1997 VL 13 IS 5 BP 1020 EP 1025 DI 10.1021/la950541f PG 6 WC Chemistry, Multidisciplinary; Chemistry, Physical; Materials Science, Multidisciplinary SC Chemistry; Materials Science GA WL748 UT WOS:A1997WL74800022 ER PT J AU Straume, T Raabe, OG Walsh, KJ Wiley, LM AF Straume, T Raabe, OG Walsh, KJ Wiley, LM TI Transmitted proliferation disadvantage from mouse oocytes labeled in vivo with [H-3]thymidine: Radiosensitive target considerations SO MUTATION RESEARCH-FUNDAMENTAL AND MOLECULAR MECHANISMS OF MUTAGENESIS LA English DT Article DE mouse oocyte; aggregation embryo chimera; tritiated thymidine; radiosensitive target; in vivo; mouse ID IMMATURE OOCYTES; EMBRYO; AGGREGATION; ASSAY; SENSITIVITY; RADIATION; CHIMERAS; INVITRO; MICE AB This study was conducted to test the hypothesis that a nuclear target is involved in the embryonic cell proliferation disadvantage transmitted by irradiated mouse oocytes and detected by the chimera assay. In this assay, the cells from the irradiated embryo exhibit a competitive cell proliferation disadvantage when they are challenged by direct cell-cell contact with cells from a normal embryo in an aggregation chimera. Here, six pregnant CD-1 mice received a total of 1.85 TBq tritiated thymidine (TdR) delivered by multiple intraperitoneal injections during days 13-15 postconception. Six more pregnant mice were sham-injected to provide control embryos. Sixty randomly selected female progeny were mated at 47 days of age and their 4-cell embryos tested in the chimera assay. The mean proliferation ratio (PR, number of cells from the experimental embryo divided by total cell number of the chimera) for experimental chimeras was 0.45+/-0.02 SE (n=43), which was significantly less than the mean PR of 0.49+/-0.01 SE (n=47; p=0.02) for control chimeras. This entire experiment was repeated, with similar results. A comparison for TdR confined to the nucleus (i.e., mean beta-ray range is only 0.7 mu m) with the relationship for uniform irradiation by Cs-137 gamma-rays demonstrates that these two very different modes of dose delivery produce essentially identical PRs. These results in vivo suggest a nuclear DNA target for embryonic cell proliferation disadvantage consistent with our previous findings in vitro. C1 LAWRENCE LIVERMORE NATL LAB,INST TOXICOL & ENVIROMN HLTH,DAVIS,CA 95616. LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94551. FU NIEHS NIH HHS [R01 ES05409-01] NR 25 TC 3 Z9 3 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0027-5107 J9 MUTAT RES-FUND MOL M JI Mutat. Res.-Fundam. Mol. Mech. Mutagen. PD MAR 4 PY 1997 VL 374 IS 1 BP 11 EP 19 DI 10.1016/S0027-5107(96)00214-X PG 9 WC Biotechnology & Applied Microbiology; Genetics & Heredity; Toxicology SC Biotechnology & Applied Microbiology; Genetics & Heredity; Toxicology GA WK788 UT WOS:A1997WK78800002 PM 9067412 ER PT J AU Fayeulle, S Nastasi, M Lu, YC Kung, H Tesmer, JR AF Fayeulle, S Nastasi, M Lu, YC Kung, H Tesmer, JR TI Thermal and ion irradiation stability of direct current sputtered TiN/B-C-N multilayers SO APPLIED PHYSICS LETTERS LA English DT Article ID PLASTIC-FLOW; STRESS AB The response of TiN/B-C-N multilayers to vacuum annealing at 900 degrees C and to 300 keV argon irradiation is studied. Changes in composition, stress field. bilayer repeat length, and layered structure are reported. The modifications observed during thermal annealing are mainly related to the departure of nitrogen because of the initial high state of compressive stress. During irradiation, the viscous flow of atoms perpendicular to the stress field causes an increase of the bilayer repeat length and interdiffusion between each layer. This mechanism leads to relaxation of stress and to the disappearance of the layered structure for higher dose. (C) 1997 American Institute of Physics. C1 LOS ALAMOS NATL LAB,DIV MAT SCI & TECHNOL,LOS ALAMOS,NM 87545. RP Fayeulle, S (reprint author), LAB MAT MECAN PHYS,F-69131 ECULLY,FRANCE. NR 14 TC 5 Z9 5 U1 0 U2 1 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 MAR 3 PY 1997 VL 70 IS 9 BP 1098 EP 1100 DI 10.1063/1.118496 PG 3 WC Physics, Applied SC Physics GA WL147 UT WOS:A1997WL14700013 ER PT J AU Schwarz, RB Khachaturyan, K Weber, ER AF Schwarz, RB Khachaturyan, K Weber, ER TI Elastic moduli of gallium nitride SO APPLIED PHYSICS LETTERS LA English DT Article ID SOLIDS AB The second-order elastic constants of wurtzite phase GaN have been measured with 0.2% accuracy using a resonance ultrasound method. The measurements were done on a 0.29-mm-thick GaN crystal grown by chloride vapor-phase transport and subsequently detached from the substrate. The elastic moduli in units of GPa are: c(11) = 377, c(12) = 160, c(13) = 114, c(33) = 209, and c(44) = 81.4. The elastic moduli are used to calculate the biaxial misfit stresses expected in heteroepitaxial thin films of GaN. (C) 1997 American Institute of Physics. C1 UNIV CALIF BERKELEY,DEPT MAT SCI & MINERAL ENGN,BERKELEY,CA 94720. UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV SCI MAT,BERKELEY,CA 94720. RP Schwarz, RB (reprint author), LOS ALAMOS NATL LAB,CTR MAT SCI,LOS ALAMOS,NM 87545, USA. NR 11 TC 95 Z9 96 U1 3 U2 7 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 MAR 3 PY 1997 VL 70 IS 9 BP 1122 EP 1124 DI 10.1063/1.118503 PG 3 WC Physics, Applied SC Physics GA WL147 UT WOS:A1997WL14700021 ER PT J AU Johnson, MJ Fleetwood, DM AF Johnson, MJ Fleetwood, DM TI Correlation between latent interface trap buildup and 1/f noise in metal-oxide-semiconductor transistors SO APPLIED PHYSICS LETTERS LA English DT Article ID FIELD-EFFECT TRANSISTORS; MOS DEVICES; ELECTRONIC DEVICES; HARDNESS ASSURANCE; FLICKER NOISE; RADIATION; STATES AB A long-term delayed increase in the 1/f noise of p-channel metal-oxide-semiconductor (MOS) transistors is observed in devices that show significant latent interface-trap buildup after exposure to ionizing radiation. During positive-bias postirradiation anneal, the noise increases by more than an order of magnitude above the level observed after irradiation. The increase in noise precedes the latent buildup of interface traps by at least 4.5 days during room-temperature annealing, and by similar to 1 h during 100 degrees C annealing. The time and temperature dependencies of the increases in noise and interface trap buildup are consistent with the thermally activated motion of protons into the near-interfacial region of the oxide, followed by increases in border trap and interface trap densities. These results suggest hydrogen-related species can significantly affect the 1/f noise of MOS devices. (C) 1997 American Institute of Physics. C1 SANDIA NATL LABS, ALBUQUERQUE, NM 87185 USA. NR 22 TC 16 Z9 16 U1 0 U2 2 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 MAR 3 PY 1997 VL 70 IS 9 BP 1158 EP 1160 DI 10.1063/1.118512 PG 3 WC Physics, Applied SC Physics GA WL147 UT WOS:A1997WL14700033 ER PT J AU Li, Q Tsay, YN Zhu, Y Suenaga, M Gu, GD Koshizuka, N AF Li, Q Tsay, YN Zhu, Y Suenaga, M Gu, GD Koshizuka, N TI Large T-c depression at low angle [100] tilt grain boundaries in bulk Bi2Sr2CaCu2O8+delta bicrystals SO APPLIED PHYSICS LETTERS LA English DT Article ID JUNCTIONS; WIRES AB Large depression of T-c at 7 degrees [100] tilt grain boundaries was observed in bulk Bi2Sr2CaCu2O8+delta (Bi2212) bicrystals by measuring the zero-field electrical transport properties of the grain boundaries and the constituent single crystals over an extended range of currents and voltages. The T-c-depressed region was determined to be around 20 nm, comparable to the width of the strain field associated With the observed array of grain-boundary dislocations. Superconducting coupling of the grain boundaries increases sharply as temperature decreases below the grain-boundary T-c congruent to 68 K. (C) 1997 American Institute of Physics. C1 UNIV NEW S WALES,SCH PHYS,KENSINGTON,NSW 2033,AUSTRALIA. ISTEC,SUPERCONDUCT RES LAB,KOTO KU,TOKYO 135,JAPAN. RP Li, Q (reprint author), BROOKHAVEN NATL LAB,DEPT APPL SCI,UPTON,NY 11973, USA. NR 11 TC 10 Z9 10 U1 0 U2 1 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 MAR 3 PY 1997 VL 70 IS 9 BP 1164 EP 1166 DI 10.1063/1.118514 PG 3 WC Physics, Applied SC Physics GA WL147 UT WOS:A1997WL14700035 ER PT J AU Nielsen, E Akita, M DavilaAponte, J Keegstra, K AF Nielsen, E Akita, M DavilaAponte, J Keegstra, K TI Stable association of chloroplastic precursors with protein translocation complexes that contain proteins from both envelope membranes and a stromal Hsp 100 molecular chaperone SO EMBO JOURNAL LA English DT Article DE chloroplasts; envelope membranes; hsp100; precursor proteins; protein import ID HEAT-SHOCK PROTEIN; MITOCHONDRIAL INNER MEMBRANE; ATP-DEPENDENT PROTEASE; ESCHERICHIA-COLI; IMPORT MACHINERY; SMALL SUBUNIT; RIBULOSE-1,5-BISPHOSPHATE CARBOXYLASE; DYNAMIC INTERACTION; YEAST MITOCHONDRIA; CLP HOMOLOG AB Cytoplasmically synthesized precursors interact with translocation components in both the outer and inner envelope membranes during transport into chloroplasts. Using co-immunoprecipitation techniques, with antibodies specific to known translocation components, we identified stable interactions between precursor proteins and their associated membrane translocation components in detergent-solubilized chloroplastic membrane fractions. Antibodies specific to the outer envelope translocation components OEP75 and OEP34, the inner envelope translocation component IEP110 and the stromal Hsp100, ClpC, specifically co-immunoprecipitated precursor proteins under limiting ATP conditions, a stage we have called docking, A portion of these same translocation components was coimmunoprecipitated as a complex, and could also be detected by co-sedimentation through a sucrose density gradient. ClpC was observed only in complexes with those precursors utilizing the general import apparatus, and its interaction with precursor-containing translocation complexes was destabilized by ATP. Finally, ClpC was co-immunoprecipitated with a portion of the translocation components of both outer and inner envelope membranes, even in the absence of added precursors. We discuss possible roles for stromal Hsp100 in protein import and mechanisms of precursor binding in chloroplasts. C1 MICHIGAN STATE UNIV,MSU DOE PLANT RES LAB,E LANSING,MI 48824. RI Nielsen, Erik/G-5843-2013 NR 61 TC 211 Z9 219 U1 0 U2 1 PU OXFORD UNIV PRESS PI OXFORD PA GREAT CLARENDON ST, OXFORD, ENGLAND OX2 6DP SN 0261-4189 J9 EMBO J JI Embo J. PD MAR 3 PY 1997 VL 16 IS 5 BP 935 EP 946 DI 10.1093/emboj/16.5.935 PG 12 WC Biochemistry & Molecular Biology; Cell Biology SC Biochemistry & Molecular Biology; Cell Biology GA WN628 UT WOS:A1997WN62800005 PM 9118955 ER PT J AU Vignaud, G Gibaud, A Wang, J Sinha, SK Daillant, J Grubel, G Gallot, Y AF Vignaud, G Gibaud, A Wang, J Sinha, SK Daillant, J Grubel, G Gallot, Y TI An x-ray scattering study of laterally modulated structures: The example of diblock copolymers SO JOURNAL OF PHYSICS-CONDENSED MATTER LA English DT Letter ID THIN-FILMS; SURFACE AB A study of the specular and off-specular (diffuse) x-ray scattering of a diblock copolymer is presented. In the ordered state the surface of the diblock copolymer is covered with islands. It is shown that the periodicity in the ordered state in the direction normal to the surface in a specular scan differs from the periodicity in the same direction observed in an off-specular scan. This result is explained by an analytical calculation of the differential cross section. The introduction of the statistical properties of the island distribution allows a complete analytical calculation of the transverse scans yielding the determination of the mean distance between the islands and the average size of an island. C1 UNIV MAINE,FAC SCI,F-72017 LE MANS,FRANCE. ARGONNE NATL LAB,ARGONNE,IL 60439. CTR ETUD SACLAY,SERV PHYS ETAT CONDENSE,F-91191 GIF SUR YVETTE,FRANCE. INST CHARLES SADRON,F-67083 STRASBOURG,FRANCE. RP Vignaud, G (reprint author), EUROPEAN SYNCHROTRON RADIAT FACIL,AVE MARTYRS,BP220,F-38043 GRENOBLE,FRANCE. NR 18 TC 24 Z9 24 U1 0 U2 4 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL, ENGLAND BS1 6BE SN 0953-8984 J9 J PHYS-CONDENS MAT JI J. Phys.-Condes. Matter PD MAR 3 PY 1997 VL 9 IS 9 BP L125 EP L130 DI 10.1088/0953-8984/9/9/003 PG 6 WC Physics, Condensed Matter SC Physics GA WM292 UT WOS:A1997WM29200003 ER PT J AU Adam, J Arenhovel, H AF Adam, J Arenhovel, H TI Intrinsic operators for the electromagnetic nuclear current SO NUCLEAR PHYSICS A LA English DT Article DE electromagnetic nuclear currents; relativistic effects; center-of-mass motion ID RELATIVISTIC CORRECTIONS; ELECTRON-SCATTERING; DEUTERON ELECTRODISINTEGRATION; PHOTODISINTEGRATION; RETARDATION; CHARGE; MODEL AB The intrinsic electromagnetic nuclear meson exchange charge and current operators arising from a separation of the center-of-mass motion are derived for a one-boson-exchange model for the nuclear interaction with scalar, pseudoscalar and vector meson exchange including leading order relativistic terms. Explicit expressions for the meson exchange operators corresponding to the different meson types are given in detail for a two-nucleon system. These intrinsic operators are to be evaluated between intrinsic wave functions in their center-of-mass frame. C1 JEFFERSON LAB,THEORY GRP,NEWPORT NEWS,VA 23606. RP Adam, J (reprint author), UNIV MAINZ,INST KERNPHYS,D-55099 MAINZ,GERMANY. RI Adam, Jiri/G-9785-2014 NR 22 TC 26 Z9 26 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0375-9474 J9 NUCL PHYS A JI Nucl. Phys. A PD MAR 3 PY 1997 VL 614 IS 3 BP 289 EP 336 DI 10.1016/S0375-9474(96)00463-0 PG 48 WC Physics, Nuclear SC Physics GA WM394 UT WOS:A1997WM39400001 ER PT J AU Burakovsky, L Horwitz, LP AF Burakovsky, L Horwitz, LP TI On the thermodynamics of hot hadronic matter SO NUCLEAR PHYSICS A LA English DT Article DE hot hadronic matter; resonance spectrum; equation of state; quark-gluon plasma; chiral symmetry restoration ID CHIRAL PHASE-TRANSITION; FINITE-TEMPERATURE; QUARK PLASMA; QCD; SPECTRUM; MODEL; PREDICTIONS; INSTANTONS; SYMMETRY; PHYSICS AB The equation of state of hot hadronic matter is obtained, by taking into account the contribution of the massive states, with the help of the resonance spectrum tau(m) similar to m(3) justified by the authors in previous papers. This equation of state is in agreement with that provided by the low-temperature expansion for the pion interacting gas. The formulas for the temperature dependence of the non-strange and strange quark condensates are derived by taking into account the contribution of the massive resonances. The critical temperature of the chiral symmetry restoration transition is established to be 190 MeV if only meson resonances are considered, and 180 MeV if both meson and baryon resonances are taken into account. The phase transition of chiral symmetry restoration is modelled by the restriction of the number of the effective degrees of freedom in the hadron phase to that of the microscopic degrees of freedom in the quark-gluon phase, through the corresponding truncation of the hadronic resonance spectrum, and the decrease of the effective hadron masses with temperature predicted by Brown and Rho. The results are in agreement with lattice gauge data and show a smooth crossover in the thermodynamic variables in a temperature range similar to 50 MeV. C1 INST ADV STUDY,SCH NAT SCI,PRINCETON,NJ 08540. BAR ILAN UNIV,DEPT PHYS,RAMAT GAN,ISRAEL. RP Burakovsky, L (reprint author), LOS ALAMOS NATL LAB,DIV THEORET,T-8,LOS ALAMOS,NM 87545, USA. NR 81 TC 13 Z9 13 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0375-9474 J9 NUCL PHYS A JI Nucl. Phys. A PD MAR 3 PY 1997 VL 614 IS 3 BP 373 EP 399 DI 10.1016/S0375-9474(96)00469-1 PG 27 WC Physics, Nuclear SC Physics GA WM394 UT WOS:A1997WM39400005 ER PT J AU Buchmuller, W McDermott, MF AF Buchmuller, W McDermott, MF TI Gluon radiation in diffractive electroproduction SO NUCLEAR PHYSICS B LA English DT Article ID DEEP-INELASTIC-SCATTERING; LARGE RAPIDITY GAP; QCD; HERA; DISSOCIATION; EVENTS; MODEL; FIELD AB Order alpha(s) corrections to the diffractive structure functions F-L(D) and F-2(D) at large Q(2) and small x are evaluated in the semiclassical approach, where the initial proton is treated as a classical color field. The diffractive final state contains a fast gluon in addition to a quark-antiquark pair, Two of these partons may have large transverse momentum. Our calculations lead to an intuitive picture of deep inelastic diffractive processes which is very similar to Bjorken's aligned-jet model. Both diffractive structure functions contain leading twist contributions from high-p(perpendicular to) jets. C1 STANFORD LINEAR ACCELERATOR CTR, STANFORD, CA 94309 USA. RP DESY, NOTKESTR 85, D-22603 HAMBURG, GERMANY. NR 31 TC 47 Z9 47 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0550-3213 EI 1873-1562 J9 NUCL PHYS B JI Nucl. Phys. B PD MAR 3 PY 1997 VL 487 IS 1-2 BP 283 EP 310 DI 10.1016/S0550-3213(96)00623-2 PG 28 WC Physics, Particles & Fields SC Physics GA WK342 UT WOS:A1997WK34200013 ER PT J AU Bardakci, K Bernardo, LM Sochen, N AF Bardakci, K Bernardo, LM Sochen, N TI Integrable generalized Thirring model SO NUCLEAR PHYSICS B LA English DT Article ID 2 DIMENSIONS; ALGEBRAS; CHARGES AB We derive the conditions that the coupling constants of the generalized Thirring model have to satisfy in order for the model to admit an infinite number of commuting classical conserved quantities. Our treatment uses the bosonized version of the model, with periodic boundary conditions imposed on the space coordinate. Some explicit examples that satisfy these conditions are discussed, We show that, with a different set of boundary conditions, there exist additional conserved quantities, and we find the Poisson bracket algebra satisfied by them. C1 UNIV CALIF BERKELEY, LAWRENCE BERKELEY LAB, THEORET PHYS GRP, BERKELEY, CA 94720 USA. RP UNIV CALIF BERKELEY, DEPT PHYS, BERKELEY, CA 94720 USA. NR 17 TC 0 Z9 0 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0550-3213 EI 1873-1562 J9 NUCL PHYS B JI Nucl. Phys. B PD MAR 3 PY 1997 VL 487 IS 1-2 BP 513 EP 525 DI 10.1016/S0550-3213(96)00715-8 PG 13 WC Physics, Particles & Fields SC Physics GA WK342 UT WOS:A1997WK34200020 ER PT J AU Zhao, XM Gulley, MS Bryant, HC Strauss, CEM Funk, DJ Stintz, A Rislove, DC Kyrala, GA Ingalls, WB Miller, WA AF Zhao, XM Gulley, MS Bryant, HC Strauss, CEM Funk, DJ Stintz, A Rislove, DC Kyrala, GA Ingalls, WB Miller, WA TI Nonresonant excess photon detachment of negative hydrogen ions SO PHYSICAL REVIEW LETTERS LA English DT Article ID MULTIPHOTON DETACHMENT; ANGULAR-DISTRIBUTIONS; 2-PHOTON DETACHMENT; IONIZATION; ELECTRON; HALOGENS; ABSORPTION; ATOMS; FIELD AB We report the first observation of nonresonant excess photon absorption (for ionization as well as detachment) in competition with the single photon process. A 35 keV negative hydrogen ion beam is irradiated with focused Nd:YAC laser pulses: the 1.165 eV photon energy exceeds the electron binding energy by 0.41 eV. The time of flight spectrum of detached electrons exhibits the absorption of one and two photons. The detached electrons exit with a P wave angular distribution for the one-photon detachment and primarily a D wave for the two photon excess photon detachment. C1 UNIV NEW MEXICO,DEPT PHYS & ASTRON,ALBUQUERQUE,NM 87131. RP Zhao, XM (reprint author), LOS ALAMOS NATL LAB,POB 1663,LOS ALAMOS,NM 87545, USA. NR 25 TC 30 Z9 32 U1 1 U2 1 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD MAR 3 PY 1997 VL 78 IS 9 BP 1656 EP 1659 DI 10.1103/PhysRevLett.78.1656 PG 4 WC Physics, Multidisciplinary SC Physics GA WL506 UT WOS:A1997WL50600013 ER PT J AU Shen, ZX Schrieffer, JR AF Shen, ZX Schrieffer, JR TI Momentum, temperature, and doping dependence of photoemission lineshape and implications for the nature of the pairing potential in high-T-c superconducting materials SO PHYSICAL REVIEW LETTERS LA English DT Article ID FERMI-LIQUID; BI2SR2CACU2O8+DELTA; YBA2CU3O7; SCATTERING; SPECTRA; PHONON; STATE AB The anomalous momentum and temperature dependence of the spectral lineshape in data from underdoped Bi2Sr2CaCu2O8+delta (Bi2212) indicates that the quasiparticles are strongly coupled to collective excitations centered near Q = (pi, pi). The doping dependence of the spectral lineshape and its correlation with the size of the superconducting gap indicate these collective excitations are related to the pairing interaction in high-T-c superconductors, in analogy with phonon induced structures in tunneling spectra of low T-c materials. C1 STANFORD UNIV, STANFORD SYNCHROTRON RADIAT LAB, STANFORD, CA 94305 USA. FLORIDA STATE UNIV, NATL HIGH MAGNET FIELD LAB, TALLAHASSEE, FL 32306 USA. FLORIDA STATE UNIV, DEPT PHYS, TALLAHASSEE, FL 32306 USA. RP STANFORD UNIV, DEPT APPL PHYS, STANFORD, CA 94305 USA. NR 29 TC 243 Z9 247 U1 2 U2 13 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 EI 1079-7114 J9 PHYS REV LETT JI Phys. Rev. Lett. PD MAR 3 PY 1997 VL 78 IS 9 BP 1771 EP 1774 DI 10.1103/PhysRevLett.78.1771 PG 4 WC Physics, Multidisciplinary SC Physics GA WL506 UT WOS:A1997WL50600042 ER PT J AU Kojima, KM Fudamoto, Y Larkin, M Luke, GM Merrin, J Nachumi, B Uemura, YJ Motoyama, N Eisaki, H Uchida, S Yamada, K Endoh, Y Hosoya, S Sternlieb, BJ Shirane, G AF Kojima, KM Fudamoto, Y Larkin, M Luke, GM Merrin, J Nachumi, B Uemura, YJ Motoyama, N Eisaki, H Uchida, S Yamada, K Endoh, Y Hosoya, S Sternlieb, BJ Shirane, G TI Reduction of ordered moment and Neel temperature of quasi-one-dimensional antiferromagnets Sr2CuO3 and Ca2CuO3 SO PHYSICAL REVIEW LETTERS LA English DT Article ID MUON-SPIN-ROTATION; RELAXATION; LA2CUO4-Y; MODEL; FIELD AB We report elastic neutron diffraction and muon spin relaxation (mu SR) measurements of the quasi-one-dimensional antiferromagnets Sr2CuO3 and Ca2CuO3, which have extraordinarily reduced T-N/J ratios. We observe almost resolution-limited antiferromagnetic Bragg reflections in Sr2CuO3 and obtain a reduced ordered moment size of similar to 0.06 mu(B). We find that the ratio of ordered moment size mu(Ca2CuO3)/mu(Sr2CuO3) = 1.5(1) roughly scales with their Neel temperatures, which suggests that the ordered moment size of quasi-one-dimensional antiferromagnets decreases continuously in the limit of vanishing interchain interactions. C1 UNIV TOKYO,DEPT APPL PHYS,TOKYO 113,JAPAN. TOHOKU UNIV,DEPT PHYS,SENDAI,MIYAGI 98077,JAPAN. YAMANASHI UNIV,INST INORGAN SYNTH,KOFU,YAMANASHI 400,JAPAN. BROOKHAVEN NATL LAB,UPTON,NY 11973. RP Kojima, KM (reprint author), COLUMBIA UNIV,DEPT PHYS,NEW YORK,NY 10027, USA. RI Yamada, Kazuyoshi/C-2728-2009; Luke, Graeme/A-9094-2010; OI Luke, Graeme/0000-0003-4762-1173 NR 36 TC 123 Z9 124 U1 3 U2 18 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD MAR 3 PY 1997 VL 78 IS 9 BP 1787 EP 1790 DI 10.1103/PhysRevLett.78.1787 PG 4 WC Physics, Multidisciplinary SC Physics GA WL506 UT WOS:A1997WL50600046 ER PT J AU Joyce, JJ Arko, AJ AF Joyce, JJ Arko, AJ TI Intrinsic photoemission spectra for YbB12 SO PHYSICAL REVIEW LETTERS LA English DT Article ID HEAVY RP Joyce, JJ (reprint author), LOS ALAMOS NATL LAB,POB 1663,LOS ALAMOS,NM 87545, USA. NR 6 TC 14 Z9 14 U1 2 U2 4 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD MAR 3 PY 1997 VL 78 IS 9 BP 1831 EP 1831 DI 10.1103/PhysRevLett.78.1831 PG 1 WC Physics, Multidisciplinary SC Physics GA WL506 UT WOS:A1997WL50600062 ER PT J AU Au, CK Chow, CK Chu, CS AF Au, CK Chow, CK Chu, CS TI Perturbative scattering phase shifts in one dimension: Closed form results SO PHYSICS LETTERS A LA English DT Article AB A simple closed form expression is obtained for the scattering phase shift perturbatively to any given order in effective half-line one-dimensional problems. The result is a hierarchical scheme, expressible in quadratures, requiring only knowledge of the zeroth order solution and the perturbation potential. C1 CORNELL UNIV,NEWMAN LAB NUCL STUDIES,ITHACA,NY 14853. UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DEPT PHYS,BERKELEY,CA 94720. UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,THEORET PHYS GRP,BERKELEY,CA 94720. RP Au, CK (reprint author), UNIV S CAROLINA,DEPT PHYS & ASTRON,COLUMBIA,SC 29208, USA. NR 19 TC 4 Z9 4 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0375-9601 J9 PHYS LETT A JI Phys. Lett. A PD MAR 3 PY 1997 VL 226 IS 6 BP 327 EP 331 DI 10.1016/S0375-9601(97)00006-6 PG 5 WC Physics, Multidisciplinary SC Physics GA WJ138 UT WOS:A1997WJ13800002 ER PT J AU Bouaricha, A AF Bouaricha, A TI Algorithm 765: STENMIN: A software package for large, sparse unconstrained optimization using tensor methods SO ACM TRANSACTIONS ON MATHEMATICAL SOFTWARE LA English DT Article DE large-scale optimization; rank-deficient matrices; sparse problems; tensor methods AB We describe a new package for minimizing an unconstrained nonlinear function where the Hessian is large and sparse. The software allows the user to select between a tensor method and a standard method based upon a quadratic model. The tensor method models the objective function by a fourth-order model, where the third- and fourth-order terms are chosen such that the extra cost of forming and solving the model is small. The new contribution of this package consists of the incorporation of an entirely new way of minimizing the tensor model that makes it suitable for solving large, sparse optimization problems efficiently. The test results indicate that, in general, the tensor method is often more efficient and more reliable than the standard Newton method for solving large, sparse unconstrained optimization problems. C1 ARGONNE NATL LAB,ARGONNE,IL 60439. NR 11 TC 1 Z9 1 U1 0 U2 0 PU ASSOC COMPUTING MACHINERY PI NEW YORK PA 1515 BROADWAY, NEW YORK, NY 10036 SN 0098-3500 J9 ACM T MATH SOFTWARE JI ACM Trans. Math. Softw. PD MAR PY 1997 VL 23 IS 1 BP 81 EP 90 DI 10.1145/244768.244788 PG 10 WC Computer Science, Software Engineering; Mathematics, Applied SC Computer Science; Mathematics GA XB995 UT WOS:A1997XB99500005 ER PT J AU Christensen, AN Norby, P Hanson, JC AF Christensen, AN Norby, P Hanson, JC TI In-situ investigation of magnesium aluminophosphate synthesis by synchrotron X-ray powder diffraction SO ACTA CHEMICA SCANDINAVICA LA English DT Article ID MOLECULAR-SIEVE; CRYSTAL-STRUCTURE; CRYSTALLIZATION; INSITU AB Time-resolved synchrotron X-ray powder diffraction was used to study synthesis of magnesium substituted aluminophosphates. Four organic template molecules were applied, which resulted in different reaction products. Triethylamine: MAPO-5 and MAPO-47. Di-n-propylamine: MAPO-39 and MAPO-46. Tripropylamine: MAPO-36. Tetramethylammonium hydroxide: MAPO-20. Some synthesis passed through the formation of precursor phases. A precursor observed in the lower temperature range of the synthesis was Mg(H2O)(4)[Al(PO3OH)OH](H2O)(2). C1 BROOKHAVEN NATL LAB,DEPT CHEM,UPTON,NY 11973. RP Christensen, AN (reprint author), AARHUS UNIV,DEPT INORGAN CHEM,DK-8000 AARHUS,DENMARK. RI Hanson, jonathan/E-3517-2010; Norby, Poul/B-9047-2014 OI Norby, Poul/0000-0002-2590-7050 NR 23 TC 19 Z9 19 U1 0 U2 5 PU MUNKSGAARD INT PUBL LTD PI COPENHAGEN PA 35 NORRE SOGADE, PO BOX 2148, DK-1016 COPENHAGEN, DENMARK SN 0904-213X J9 ACTA CHEM SCAND JI Acta Chem. Scand. PD MAR PY 1997 VL 51 IS 3 BP 249 EP 258 DI 10.3891/acta.chem.scand.51-0249 PG 10 WC Biochemistry & Molecular Biology; Chemistry, Multidisciplinary SC Biochemistry & Molecular Biology; Chemistry GA WP362 UT WOS:A1997WP36200001 ER PT J AU Christensen, AN Norby, P Hanson, JC AF Christensen, AN Norby, P Hanson, JC TI Superconducting cuprates and related oxides .9. In situ synchrotron x-ray powder diffraction investigation of the oxidation and reduction of YBa2Cu3O7-delta in a flow of oxygen or of nitrogen gas in the temperature range 400-725 degrees C SO ACTA CHEMICA SCANDINAVICA LA English DT Article C1 BROOKHAVEN NATL LAB,DEPT CHEM,UPTON,NY 11972. RP Christensen, AN (reprint author), AARHUS UNIV,DEPT INORGAN CHEM,DK-8000 AARHUS,DENMARK. RI Hanson, jonathan/E-3517-2010; Norby, Poul/B-9047-2014 OI Norby, Poul/0000-0002-2590-7050 NR 2 TC 0 Z9 0 U1 0 U2 0 PU MUNKSGAARD INT PUBL LTD PI COPENHAGEN PA 35 NORRE SOGADE, PO BOX 2148, DK-1016 COPENHAGEN, DENMARK SN 0904-213X J9 ACTA CHEM SCAND JI Acta Chem. Scand. PD MAR PY 1997 VL 51 IS 3 BP 340 EP 342 DI 10.3891/acta.chem.scand.51-0340 PG 3 WC Biochemistry & Molecular Biology; Chemistry, Multidisciplinary SC Biochemistry & Molecular Biology; Chemistry GA WP362 UT WOS:A1997WP36200016 ER PT J AU Bian, WM Zhu, YM AF Bian, WM Zhu, YM TI A crystal model for the icosahedral phase SO ACTA CRYSTALLOGRAPHICA SECTION A LA English DT Article ID RESOLUTION ELECTRON-MICROSCOPY; TWO-DIMENSIONAL QUASICRYSTAL; AL-CU-FE; DECAGONAL QUASICRYSTALS; TRANSLATIONAL SYMMETRY; CUBIC-CRYSTALS; DIFFRACTION; ALLOY; TWINS AB A crystal model is proposed that is in good agreement with the experimental electron diffraction patterns and high-resolution electron-microscopy images of the icosahedral phase in Mn-Al and related systems. Structurally, the model has long-range periodic translational order with a large unit cell (space group Im(3) over bar containing 10038 atoms as well as orientational order characterized by symmetry close to the (5) over bar point group. Such a periodic structure can explain the origin of the crystallographically forbidden icosahedral symmetries. The icosahedral phase may thus be considered as a complex cubic crystal. RP Bian, WM (reprint author), BROOKHAVEN NATL LAB,DIV MAT SCI,UPTON,NY 11973, USA. NR 27 TC 3 Z9 3 U1 0 U2 0 PU MUNKSGAARD INT PUBL LTD PI COPENHAGEN PA 35 NORRE SOGADE, PO BOX 2148, DK-1016 COPENHAGEN, DENMARK SN 0108-7673 J9 ACTA CRYSTALLOGR A JI Acta Crystallogr. Sect. A PD MAR 1 PY 1997 VL 53 BP 175 EP 180 DI 10.1107/S0108767396012755 PN 2 PG 6 WC Chemistry, Multidisciplinary; Crystallography SC Chemistry; Crystallography GA WP968 UT WOS:A1997WP96800008 ER PT J AU Keblinski, P Phillpot, SR Wolf, D Gleiter, H AF Keblinski, P Phillpot, SR Wolf, D Gleiter, H TI Amorphous structure of grain boundaries and grain junctions in nanocrystalline silicon by molecular-dynamics simulation SO ACTA MATERIALIA LA English DT Article ID TEMPERATURE; RELAXATION AB Molecular-dynamics simulations using the Stillinger-Weber three-body potential are used to synthesize fully dense nanocrystalline silicon with a grain size up to 7.3 nm by crystallization from the melt. The structures of the highly-constrained grain boundaries, triple lines and point grain junctions are found to be highly disordered and similar to the structure of amorphous silicon. These results suggest that nanocrystalline silicon may be treated as a two-phase system, namely, an ordered crystalline phase in the grain interiors connected by an amorphous, intergranular glue-like phase. Copyright (C) 1997 Acta Metallurgica Inc. C1 FORSCHUNGSZENTRUM KARLSRUHE, D-76021 KARLSRUHE, GERMANY. RP ARGONNE NATL LAB, DIV MAT SCI, 9700 S CASS AVE, ARGONNE, IL 60439 USA. RI Phillpot, Simon/J-9117-2012; OI Phillpot, Simon/0000-0002-7774-6535 NR 31 TC 98 Z9 100 U1 4 U2 17 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 1359-6454 EI 1873-2453 J9 ACTA MATER JI Acta Mater. PD MAR PY 1997 VL 45 IS 3 BP 987 EP 998 DI 10.1016/S1359-6454(96)00236-4 PG 12 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA WK702 UT WOS:A1997WK70200008 ER PT J AU Che, DZ Spooner, S Hoyt, JJ AF Che, DZ Spooner, S Hoyt, JJ TI Experimental and theoretical investigation of the scaled structure function in Al-Li alloys SO ACTA MATERIALIA LA English DT Article ID SMALL-ANGLE SCATTERING; PHASE-SEPARATION; VOLUME FRACTION; SPATIAL CORRELATIONS; BINARY-ALLOYS; KINETICS; DYNAMICS; ZN; DECOMPOSITION; TRANSITIONS AB Through the use of small angle X-ray scattering the late time, scaled structure function was measured in several Al-Li alloy samples. The small misfit strain between the Al rich matrix and the metastable Al-Li precipitates renders this system ideal for an accurate test of coarsening theories which include the effect of spatial correlations between particles. The breadth of the scaled structure function, measured by the full width at half maximum, vs the equilibrium volume fraction agrees very well with the computer simulation of Akaiwa and Voorhees. In addition, the scaled structure function based on the Marder theory is derived and shown to be much broader than the experimental results. C1 OAK RIDGE NATL LAB,DIV SOLID STATE,OAK RIDGE,TN 37831. RP Che, DZ (reprint author), WASHINGTON STATE UNIV,SCH MECH & MAT ENGN,PULLMAN,WA 99164, USA. NR 36 TC 6 Z9 7 U1 0 U2 2 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 1359-6454 J9 ACTA MATER JI Acta Mater. PD MAR PY 1997 VL 45 IS 3 BP 1167 EP 1174 DI 10.1016/S1359-6454(97)85986-1 PG 8 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA WK702 UT WOS:A1997WK70200025 ER PT J AU Ward, BFL Jadach, S Melles, M Placzek, W RichterWas, E Skrzypek, M Was, Z Yost, SA AF Ward, BFL Jadach, S Melles, M Placzek, W RichterWas, E Skrzypek, M Was, Z Yost, SA TI Precise calculations of the Bhabha process SO ACTA PHYSICA POLONICA B LA English DT Article; Proceedings Paper CT 3rd International Symposium on Radiative Corrections CY AUG 01-05, 1996 CL KRAKOW, POLAND SP H Niewodniczanski Inst Nucl Phys Cracow, Polish State Comm Sci Res ID FERMION PAIR PRODUCTION; MONTE-CARLO PROGRAM; RADIATIVE-CORRECTIONS; HIGH-ENERGIES; MULTIPLE BREMSSTRAHLUNG; PHOTON CORRECTIONS; EVENT GENERATOR; CROSS-SECTIONS; GAUGE-THEORIES; SOFT PHOTONS AB We present the current status of the YFS Monte Carlo approach to high precision calculations of both small and large angle Bhabha scattering at high energies. We discuss comparisons which we have made with the available literature where possible, at both LEP1/SLC energies and at LEP2 energies. Throughout the discussion, we pay attention to the luminosity determination at LEP1/SLC for the small angle process and the analysis of wide angle Bhabha Z physics parameters and possible new LEP2 physics backgrounds for the wide angle process. In this way, the role of high precision Bhabha scattering calculations in exploration of the Standard Model and its possible extensions is made more manifest. C1 STANFORD UNIV,STANFORD LINEAR ACCELERATOR CTR,STANFORD,CA 94309. CERN,DIV THEORY,CH-1211 GENEVA 23,SWITZERLAND. INST NUCL PHYS,KRAKOW,POLAND. JAGIELLONIAN UNIV,INST COMP SCI,PL-30072 KRAKOW,POLAND. RP Ward, BFL (reprint author), UNIV TENNESSEE,DEPT PHYS & ASTRON,KNOXVILLE,TN 37996, USA. RI Yost, Scott/F-9759-2010 NR 52 TC 4 Z9 4 U1 0 U2 0 PU ACTA PHYSICA POLONICA B, JAGELLONIAN UNIV, INST PHYSICS PI KRAKOW PA REYMONTA 4, 30-059 KRAKOW, POLAND SN 0587-4254 J9 ACTA PHYS POL B JI Acta Phys. Pol. B PD MAR-APR PY 1997 VL 28 IS 3-4 BP 925 EP 942 PG 18 WC Physics, Multidisciplinary SC Physics GA WY710 UT WOS:A1997WY71000037 ER PT J AU Mah, R AF Mah, R TI Directed light fabrication SO ADVANCED MATERIALS & PROCESSES LA English DT Article AB This unconventional metal forming process presents new possibilities for the mechanical and metallurgical design of components. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87544 USA. RP Mah, R (reprint author), Univ Calif Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87544 USA. NR 0 TC 20 Z9 23 U1 1 U2 2 PU ASM INTERNATIONAL PI MATERIALS PARK PA SUBSCRIPTIONS SPECIALIST CUSTOMER SERVICE, MATERIALS PARK, OH 44073-0002 USA SN 0026-0665 J9 ADV MATER PROCESS JI Adv. Mater. Process. PD MAR PY 1997 VL 151 IS 3 BP 31 EP 33 PG 3 WC Materials Science, Multidisciplinary SC Materials Science GA ZA402 UT WOS:000072359900005 ER PT J AU Superko, HR AF Superko, HR TI Elevated high-density lipoprotein cholesterol, not protective in the presence of homocysteinemia SO AMERICAN JOURNAL OF CARDIOLOGY LA English DT Article ID VASCULAR-DISEASE; RISK FACTOR; HYPERHOMOCYST(E)INEMIA C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY NATL LAB,BERKELEY,CA 94720. RP Superko, HR (reprint author), CHOLESTEROL GENET & HEART DIS INST,1875 S GRAND ST,SUITE 700,SAN MATEO,CA 94402, USA. OI Superko, H. Robert/0000-0002-3542-0393 NR 11 TC 5 Z9 5 U1 0 U2 0 PU EXCERPTA MEDICA INC PI NEW YORK PA 245 WEST 17TH STREET, NEW YORK, NY 10011 SN 0002-9149 J9 AM J CARDIOL JI Am. J. Cardiol. PD MAR 1 PY 1997 VL 79 IS 5 BP 705 EP 706 PG 2 WC Cardiac & Cardiovascular Systems SC Cardiovascular System & Cardiology GA WL735 UT WOS:A1997WL73500040 PM 9068544 ER PT J AU Krauss, RM AF Krauss, RM TI Understanding the basis for variation in response to cholesterol-lowering diets SO AMERICAN JOURNAL OF CLINICAL NUTRITION LA English DT Editorial Material ID PHENOTYPE RP Krauss, RM (reprint author), UNIV CALIF BERKELEY,ERNEST ORLANDO LAWRENCE BERKELEY NATL LAB,DONNER LAB ROOM 465,1 CYCLOTRON RD,BERKELEY,CA 94720, USA. FU NHLBI NIH HHS [HL 18574] NR 10 TC 10 Z9 10 U1 0 U2 0 PU AMER SOC CLINICAL NUTRITION PI BETHESDA PA 9650 ROCKVILLE PIKE, SUBSCRIPTIONS, RM L-2310, BETHESDA, MD 20814-3998 SN 0002-9165 J9 AM J CLIN NUTR JI Am. J. Clin. Nutr. PD MAR PY 1997 VL 65 IS 3 BP 885 EP 886 PG 2 WC Nutrition & Dietetics SC Nutrition & Dietetics GA WK840 UT WOS:A1997WK84000026 PM 9062545 ER PT J AU Rau, ARP Inokuti, M AF Rau, ARP Inokuti, M TI The quantum defect: Early history and recent developments SO AMERICAN JOURNAL OF PHYSICS LA English DT Article AB The notion of the quantum defect is important in atomic and molecular spectroscopy and also in unifying spectroscopy with collision theory. In the latter context, the quantum defect may be viewed as an ancestor of the phase shift. However, the origin of the term ''quantum defect'' does not seem to be explained in standard textbooks. It occurred in a 1921 paper by Schrodinger, preceding quantum mechanics, yet giving the correct meaning as an index of the short-range interactions with the core of an atom. We present the early history of the quantum-defect idea, and sketch its recent developments. (C) 1997 American Association of Physics Teachers. C1 ARGONNE NATL LAB,DIV PHYS,ARGONNE,IL 60439. RP Rau, ARP (reprint author), LOUISIANA STATE UNIV,DEPT PHYS & ASTRON,BATON ROUGE,LA 70803, USA. NR 46 TC 9 Z9 9 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0002-9505 J9 AM J PHYS JI Am. J. Phys. PD MAR PY 1997 VL 65 IS 3 BP 221 EP 225 DI 10.1119/1.18532 PG 5 WC Education, Scientific Disciplines; Physics, Multidisciplinary SC Education & Educational Research; Physics GA WK409 UT WOS:A1997WK40900014 ER PT J AU Kim, JH Kiefer, LL Woychik, RP Wilkison, WO Truesdale, A Ittoop, O Willard, D Nichols, J Zemel, MB AF Kim, JH Kiefer, LL Woychik, RP Wilkison, WO Truesdale, A Ittoop, O Willard, D Nichols, J Zemel, MB TI Agouti regulation of intracellular calcium: Role of melanocortin receptors SO AMERICAN JOURNAL OF PHYSIOLOGY-ENDOCRINOLOGY AND METABOLISM LA English DT Article DE insulin resistance; obesity; alpha-melanocyte-stimulating hormone; viable yellow mice ID CYTOSOLIC FREE CALCIUM; STIMULATING-HORMONE-RECEPTOR; INSULIN-RESISTANCE; ECTOPIC EXPRESSION; YELLOW MICE; GENE; ADIPOCYTES; OBESITY; PROTEIN; CA2+ AB Several dominant mutations at the murine agouti locus cause a syndrome of marked obesity and insulin resistance. We have recently reported that intracellular free Ca2+ concentration ([Ca2+](i)) is elevated in viable yellow mice. Because [Ca2+](i) has a key role in the pathogenesis of insulin resistance, obesity, and hypertension, the role of the purified agouti gene product in regulating [Ca2+](i) was evaluated in a number of cell types. Purified murine agouti induced slow, sustained increases in [Ca2+](i) in A7r5 vascular smooth muscle cells and 3T3-L1 adipocytes in a dose-dependent fashion. In L6 skeletal myocytes, agouti stimulated an increase in [Ca2+](i) with an apparent concentration eliciting 50% of the maximal response (EC(50)) Of 62 nM. This response was substantially inhibited by Ca2+ entry blockade with nitrendipine. To determine whether melanocortin receptors play a role in agouti regulation of [Ca2+](i), we examined the effect of melanocortin peptides and agouti in cells stably transfected with human melanocortin receptors. Human embryonic kidney cells (HEK-293 cells) transfected with either the human melanocortin 1 receptor (MC1R) or melanocortin 3 receptor responded to human agouti with slow, sustained increases in [Ca2+](i), whereas nontransfected HEK-293 cells with no melanocortin receptors did not respond to agouti. Dose-response curves in the MC1R line showed that agouti had an EC(50) of 18 nM, which is comparable to that for agouti antagonism of I-125-Nle,D-Phe-alpha-melanocyte-stimulating hormone binding in the same cell line. This direct effect of agouti on stimulating increases in [Ca2+](i) suggests a potential mechanism for agouti-induced insulin resistance. C1 UNIV TENNESSEE, DEPT NUTR, KNOXVILLE, TN 37996 USA. UNIV TENNESSEE, PHYSIOL PROGRAM, KNOXVILLE, TN 37996 USA. OAK RIDGE NATL LAB, DIV BIOL, OAK RIDGE, TN 37831 USA. GLAXO RES INST, DIV BIOCHEM, RES TRIANGLE PK, NC 27709 USA. NR 33 TC 56 Z9 57 U1 1 U2 7 PU AMER PHYSIOLOGICAL SOC PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814 SN 0193-1849 J9 AM J PHYSIOL-ENDOC M JI Am. J. Physiol.-Endocrinol. Metab. PD MAR PY 1997 VL 272 IS 3 BP E379 EP E384 PG 6 WC Endocrinology & Metabolism; Physiology SC Endocrinology & Metabolism; Physiology GA WP364 UT WOS:A1997WP36400007 PM 9124542 ER PT J AU Marshall, RC Taylor, SE Powers-Risius, P Reutter, BW Kuruc, A Coxson, PG Huesman, RH Budinger, TF AF Marshall, RC Taylor, SE Powers-Risius, P Reutter, BW Kuruc, A Coxson, PG Huesman, RH Budinger, TF TI Kinetic analysis of rubidium and thallium as deposited myocardial blood flow tracers in isolated rabbit heart SO AMERICAN JOURNAL OF PHYSIOLOGY-HEART AND CIRCULATORY PHYSIOLOGY LA English DT Article DE perfusion; single positron emission computed tomography; positron emission tomography; potassium analogs; radioisotope ID CORONARY FLOW; ENERGY-PRODUCTION; TL-201; EXTRACTION; PERFUSION; REPERFUSION; ISONITRILE; CAPILLARY; RETENTION; POTASSIUM AB Evaluation of myocardial perfusion with tracers such as thallium and rubidium is based on the assumption that tissue tracer content is proportional to flow. The purpose of this study was to evaluate the relationship between flow and tissue tracer content of Tl-201 and Rb-83 in the isolated perfused rabbit heart. Rb-83 (86-day half-life), an isotope that is not used clinically, was used as a subsitute for Rb-82 (76-s half-life) to improve the accuracy and precision of data acquisition. The multiple indicator-dilution technique was employed with two independent computational approaches. The first approach explicitly deconvolved Tl-201 and Rb-83 venous concentration curves by the intravascular reference tracer curve. The second approach used a conventional analysis. Both approaches showed that there was more early washout of Rb-83 than Tl-201 and that the heart retained Tl-201 better than Rb-83 within 2 min after isotope introduction. These data indicate that Tl-201 is a better perfusion tracer than Rb-83 in the isolated rabbit heart. C1 EO Lawrence Berkeley Natl Lab, Ctr Funct Imaging, Berkeley, CA 94720 USA. Martinez Vet Affairs, No Calif Hlth Care Syst, Martinez, CA 94553 USA. RP Marshall, RC (reprint author), EO Lawrence Berkeley Natl Lab, Ctr Funct Imaging, Bldg 55-121,1 Cyclotron Rd, Berkeley, CA 94720 USA. NR 27 TC 10 Z9 10 U1 0 U2 0 PU AMER PHYSIOLOGICAL SOC PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814 SN 0363-6135 J9 AM J PHYSIOL-HEART C JI Am. J. Physiol.-Heart Circul. Physiol. PD MAR PY 1997 VL 272 IS 3 BP H1480 EP H1490 PG 11 WC Cardiac & Cardiovascular Systems; Physiology; Peripheral Vascular Disease SC Cardiovascular System & Cardiology; Physiology GA WP598 UT WOS:A1997WP59800052 ER PT J AU Goldstein, SJ Hensley, CA Armenta, CE Peters, RJ AF Goldstein, SJ Hensley, CA Armenta, CE Peters, RJ TI Environmental and human monitoring of Americium-241 utilizing extraction chromatography and alpha-spectrometry SO ANALYTICAL CHEMISTRY LA English DT Article ID ACIDIC MEDIA; SEPARATION; PRECONCENTRATION; ACTINIDES AB Recent developments in extraction chromatography have simplified the separation of americium from complex matrices in preparation for alpha-spectroscopy relative to traditional methods. Here we present results of procedures developed/adapted for water, air, and bioassay samples with less than 1 g of inorganic residue. Prior analytical methods required the use of a complex, multistage procedure for separation of americium from these matrices. The newer, simplified procedure requires only a single 2 mL extraction chromatographic separation for isolation of Am and lanthanides from other components of the sample. This method has been implemented on an extensive variety of ''real'' environmental and bioassay samples from the Los Alamos area, and consistently reliable and accurate results with appropriate detection limits have been obtained. The new method increases analytical throughput by a factor of similar to 2 and decreases environmental hazards from acid and mixed-waste generation relative to the prior technique. Analytical accuracy, reproducibility, and reliability are also significantly improved over the more complex and laborious method used previously. RP Goldstein, SJ (reprint author), UNIV CALIF LOS ALAMOS NATL LAB,GRP CST 9,MS K484,LOS ALAMOS,NM 87545, USA. NR 11 TC 13 Z9 13 U1 0 U2 3 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0003-2700 J9 ANAL CHEM JI Anal. Chem. PD MAR 1 PY 1997 VL 69 IS 5 BP 809 EP 812 DI 10.1021/ac960728r PG 4 WC Chemistry, Analytical SC Chemistry GA WK383 UT WOS:A1997WK38300012 PM 9068269 ER PT J AU Lewis, RV Freeman, MP Rodger, AS Reeves, GD Milling, DK AF Lewis, RV Freeman, MP Rodger, AS Reeves, GD Milling, DK TI The electric field response to the growth phase and expansion phase onset of a small isolated substorm SO ANNALES GEOPHYSICAE-ATMOSPHERES HYDROSPHERES AND SPACE SCIENCES LA English DT Article ID TWO-DIMENSIONAL OBSERVATIONS; WESTWARD TRAVELING SURGE; AURORAL-ZONE CURRENTS; MAGNETOSPHERIC SUBSTORMS; PRECIPITATION; CONVECTION; PLASMA; RADAR; OVAL AB We capitalise on the very large held of view of the Halley HF radar to provide a comprehensive description of the electric field response to the substorm growth phase and expansion phase onset of a relatively simple isolated substorm (\AL\ < 250 nT) which occurred on 13 June 1988. The substorm phases are identified by their standard ground magnetic and spacecraft energetic particle signatures, which provide a framework for the radar measurements. The substorm is preceded by a prolonged period (>12 h) of magnetic quiescence, such that prior to the start of the growth phase, the apparent latitudinal motion of the radar backscatter returns is consistent with the variation in latitude of the quiet-time auroral oval with magnetic local time. The growth phase is characterised by an increasing, superimposed equatorward motion of the equatorward edge of the radar backscatter as the auroral oval expands. Within this backscatter region, there is a poleward gradient in the Doppler spectral width, which we believe to correspond to latitudinal structure in auroral emissions and magnetospheric precipitation. During the growth phase the ionospheric convection is dominated by a relatively smooth large-scale flow pattern consistent with the expanding DP2 (convection) auroral electrojets. Immediately prior to substorm onset the ionospheric convection observed by the radar in the midnight sector has a predominantly equatorward flow component. At substorm onset a dramatic change occurs and a poleward flow component prevails. The timing and location are quite remarkable. The timing of the flow change is within one minute of the dispersionless injection observed at geostationary orbit and the Pi2 magnetic signature on the ground. The location shows that this sudden change in flow is due to the effect of the upward held aligned current of the substorm current wedge imposed directly within the Halley radar field of view. C1 LOS ALAMOS NATL LAB,MS D436,NIS2,LOS ALAMOS,NM 87545. UNIV YORK,DEPT PHYS,YORK YO1 5DD,N YORKSHIRE,ENGLAND. RP Lewis, RV (reprint author), BRITISH ANTARCTIC SURVEY,NERC,HIGH CROSS,MADINGLEY RD,CAMBRIDGE CB3 0ET,ENGLAND. RI Reeves, Geoffrey/E-8101-2011 OI Reeves, Geoffrey/0000-0002-7985-8098 NR 27 TC 33 Z9 33 U1 0 U2 0 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 SN 0992-7689 J9 ANN GEOPHYS-ATM HYDR JI Ann. Geophys.-Atmos. Hydrospheres Space Sci. PD MAR PY 1997 VL 15 IS 3 BP 289 EP 299 DI 10.1007/s005850050443 PG 11 WC Astronomy & Astrophysics; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences SC Astronomy & Astrophysics; Geology; Meteorology & Atmospheric Sciences GA WM891 UT WOS:A1997WM89100002 ER PT J AU Su, BJ Pomraning, GC AF Su, BJ Pomraning, GC TI Variationally improved fermi beam solutions SO ANNALS OF NUCLEAR ENERGY LA English DT Article ID MULTIPLE-SCATTERING THEORY; PARTICLE-BEAM AB The time-independent, transmission problem for a purely scattering, homogeneous slab of finite thickness is considered. This problem corresponds to a planar beam of radiation impinging perpendicularly upon one surface of a source-free slab. The scattering process is assumed sufficiently peaked in the forward direction so that the Fokker-Planck differential scattering operator can be used. Further, the slab is assumed sufficiently thin so that radiation backscattering is negligibly small. Generally, this problem is approximated by the classic Fermi solution. By using the recently reported solution for an obliquely incident pencil beam, we show that the Fermi solution (or any other approximate solution) can be improved via a variational formalism. Copyright (C) 1996 Elsevier Science Ltd C1 UNIV CALIF LOS ANGELES,SCH ENGN & APPL SCI,LOS ANGELES,CA 90095. RP Su, BJ (reprint author), LOS ALAMOS NATL LAB,POB 1663,LOS ALAMOS,NM 87545, USA. NR 21 TC 1 Z9 1 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0306-4549 J9 ANN NUCL ENERGY JI Ann. Nucl. Energy PD MAR PY 1997 VL 24 IS 4 BP 287 EP 301 DI 10.1016/S0306-4549(96)00061-8 PG 15 WC Nuclear Science & Technology SC Nuclear Science & Technology GA WB914 UT WOS:A1997WB91400004 ER PT J AU Holtzapple, MT Torget, R AF Holtzapple, MT Torget, R TI Thermal, chemical, and biological processing SO APPLIED BIOCHEMISTRY AND BIOTECHNOLOGY LA English DT Editorial Material C1 NATL RENEWABLE ENERGY LAB,GOLDEN,CO. RP Holtzapple, MT (reprint author), TEXAS A&M UNIV,COLLEGE STN,TX 77843, USA. NR 0 TC 1 Z9 1 U1 0 U2 1 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 SPR PY 1997 VL 63-5 BP 1 EP 2 DI 10.1007/BF02920407 PG 2 WC Biochemistry & Molecular Biology; Biotechnology & Applied Microbiology SC Biochemistry & Molecular Biology; Biotechnology & Applied Microbiology GA XB483 UT WOS:A1997XB48300002 PM 18576064 ER PT J AU SariskyReed, V Woodward, J AF SariskyReed, V Woodward, J TI Biological research SO APPLIED BIOCHEMISTRY AND BIOTECHNOLOGY LA English DT Editorial Material C1 OAK RIDGE NATL LAB,OAK RIDGE,TN. RP SariskyReed, V (reprint author), US DOE,WASHINGTON,DC, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 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 SPR PY 1997 VL 63-5 BP 71 EP 71 DI 10.1007/BF02920413 PG 1 WC Biochemistry & Molecular Biology; Biotechnology & Applied Microbiology SC Biochemistry & Molecular Biology; Biotechnology & Applied Microbiology GA XB483 UT WOS:A1997XB48300008 PM 18576070 ER PT J AU Ghirardi, ML Togasaki, RK Seibert, M AF Ghirardi, ML Togasaki, RK Seibert, M TI Oxygen sensitivity of algal H-2-production SO APPLIED BIOCHEMISTRY AND BIOTECHNOLOGY LA English DT Article; Proceedings Paper CT 18th Symposium on Biotechnology for Fuels and Chemicals CY MAY 05-09, 1996 CL GATLINBURG, TN SP US DOE, Div Biofuels Energy Syst, US DOE, Biol & Chem Technol Res Program, Oak Ridge Natl Lab, Natl Renewable Energy Lab, Idaho Natl Lab, Lockheed Martin Energy Syst Inc, A E Staley Mfg Co, Archer Daniels Midland Co, Bio-Tech Resources L P, Chronopol Inc, ConAgra Grain Processing Co, Enzyme Bio-Syst Ltd, DuPont Co, Grain Processing Corp, Raphael Katzen Associates Int Inc, Weyerhaeuser Co, Amer Chem Soc, Div Biochem Technol DE hydrogen; green algae; Chlamydomonas; oxygen; metronidazole ID CHLAMYDOMONAS-REINHARDTII; HYDROGENASE AB Photoproduction of H-2 by green algae utilizes electrons originating from the photosynthetic oxidation of water and does not require metabolic intermediates. However, algal hydrogenases are extremely sensitive to O-2, which limits their usefulness in future commercial H-2-production systems. We designed an experimental technique for the selection of O-2-tolerant, H-2-producing variants of Chlamydomonas reinhardtii based on the ability of wild-type cells to survive a short (20 min) exposure to metronidazole in the presence of controlled concentrations of O-2. The number of survivors depends on the metronidazole concentration, light intensity, preinduction of the hydrogenase, and the presence or absence of O-2. Finally, we demonstrate that some of the selected survivors in fact exhibit H-2-production capacity that is less sensitive to O-2 than the original wild-type population. C1 INDIANA UNIV,DEPT BIOL,BLOOMINGTON,IN 47405. RP Ghirardi, ML (reprint author), NATL RENEWABLE ENERGY LAB,GOLDEN,CO 80401, USA. NR 17 TC 155 Z9 163 U1 3 U2 29 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 SPR PY 1997 VL 63-5 BP 141 EP 151 DI 10.1007/BF02920420 PG 11 WC Biochemistry & Molecular Biology; Biotechnology & Applied Microbiology SC Biochemistry & Molecular Biology; Biotechnology & Applied Microbiology GA XB483 UT WOS:A1997XB48300015 PM 18576077 ER PT J AU Stols, L Kulkarni, G Harris, BG Donnelly, MI AF Stols, L Kulkarni, G Harris, BG Donnelly, MI TI Expression of Ascaris suum malic enzyme in a mutant Escherichia coli allows production of succinic acid from glucose SO APPLIED BIOCHEMISTRY AND BIOTECHNOLOGY LA English DT Article; Proceedings Paper CT 18th Symposium on Biotechnology for Fuels and Chemicals CY MAY 05-09, 1996 CL GATLINBURG, TN SP US DOE, Div Biofuels Energy Syst, US DOE, Biol & Chem Technol Res Program, Oak Ridge Natl Lab, Natl Renewable Energy Lab, Idaho Natl Lab, Lockheed Martin Energy Syst Inc, A E Staley Mfg Co, Archer Daniels Midland Co, Bio-Tech Resources L P, Chronopol Inc, ConAgra Grain Processing Co, Enzyme Bio-Syst Ltd, DuPont Co, Grain Processing Corp, Raphael Katzen Associates Int Inc, Weyerhaeuser Co, Amer Chem Soc, Div Biochem Technol DE metabolic engineering; succinic acid; Escherichia coli; malic enzyme; Ascaris suum ID DEHYDROGENASE; BACTERIA AB The malic enzyme gene of Ascaris suum was cloned into the vector pTRC99a in two forms encoding alternative amino-termini. The resulting plasmids, pMEA1 and pMEA2, were introduced into Escherichia coli NZN111, a strain that is unable to grow fermentatively because of inactivation of the genes encoding pyruvate dissimilation. Induction of pMEA1, which encodes the native animoterminus, gave better overexpression of malic enzyme, approx 12-fold compared to uninduced cells. Under the appropriate culture conditions, expression of malic enzyme allowed the fermentative dissimilation of glucose by NZN111. The major fermentation product formed in induced cultures was succinic acid. C1 ARGONNE NATL LAB,DIV ENVIRONM RES,ARGONNE,IL 60439. UNIV N TEXAS,DEPT BIOCHEM & MOL BIOL,FT WORTH,TX 76107. NR 17 TC 28 Z9 32 U1 2 U2 8 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 SPR PY 1997 VL 63-5 BP 153 EP 158 DI 10.1007/BF02920421 PG 6 WC Biochemistry & Molecular Biology; Biotechnology & Applied Microbiology SC Biochemistry & Molecular Biology; Biotechnology & Applied Microbiology GA XB483 UT WOS:A1997XB48300016 PM 9170244 ER PT J AU Toon, ST Philippidis, GP Ho, NWY Chen, ZD Brainard, A Lumpkin, RE Riley, CJ AF Toon, ST Philippidis, GP Ho, NWY Chen, ZD Brainard, A Lumpkin, RE Riley, CJ TI Enhanced cofermentation of glucose and xylose by recombinant Saccharomyces yeast strains in batch and continuous operating modes SO APPLIED BIOCHEMISTRY AND BIOTECHNOLOGY LA English DT Article; Proceedings Paper CT 18th Symposium on Biotechnology for Fuels and Chemicals CY MAY 05-09, 1996 CL GATLINBURG, TN SP US DOE, Div Biofuels Energy Syst, US DOE, Biol & Chem Technol Res Program, Oak Ridge Natl Lab, Natl Renewable Energy Lab, Idaho Natl Lab, Lockheed Martin Energy Syst Inc, A E Staley Mfg Co, Archer Daniels Midland Co, Bio-Tech Resources L P, Chronopol Inc, ConAgra Grain Processing Co, Enzyme Bio-Syst Ltd, DuPont Co, Grain Processing Corp, Raphael Katzen Associates Int Inc, Weyerhaeuser Co, Amer Chem Soc, Div Biochem Technol DE simultaneous saccharification and cofermentation; glucose and xylose fermentation; cellulosic biomass; recombinant Saccharomyces sp.; fermentation scale-up ID ETHANOL TOLERANCE; ACETIC-ACID; FERMENTATION; CEREVISIAE AB Agricultural residues, such as grain by-products, are rich in the hydrolyzable carbohydrate polymers hemicellulose and cellulose; hence, they represent a readily available source of the fermentable sugars xylose and glucose. The biomass-to-ethanol technology is now a step closer to commercialization because a stable recombinant yeast strain has been developed that can efficiently ferment glucose and xylose simultaneously (coferment) to ethanol. This strain, LNH-ST, is a derivative of Saccharomyces yeast strain 1400 that carries the xylose-catabolism encoding genes of Pichia stipitis in its chromosome. Continuous pure sugar cofermentation studies with this organism resulted in promising steady-state ethanol yields (70.4% of theoretical based on available sugars) at a residence time of 48 h. Further studies with corn biomass pretreated at the pilot scale confirmed the performance characteristics of the organism in a simultaneous saccharification and cofermentation (SSCF) process: LNH-ST converted 78.4% of the available glucose and 56.1% of the available xylose within 4 d, despite the presence of high levels of metabolic inhibitors. These SSCF data were reproducible at the bench scale and verified in a 9000-L pilot scale bioreactor. C1 NATL RENEWABLE ENERGY LAB,BIOTECHNOL CTR FUELS & CHEM,GOLDEN,CO 80401. PURDUE UNIV,RENEWABLE RESOURCES ENGN LAB,W LAFAYETTE,IN 47907. SWAN BIOMASS CO,DOWNERS GROVE,IL 60515. THERMO FIBERGEN INC,BEDFORD,MA 01730. NR 16 TC 26 Z9 27 U1 0 U2 5 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 SPR PY 1997 VL 63-5 BP 243 EP 255 DI 10.1007/BF02920428 PG 13 WC Biochemistry & Molecular Biology; Biotechnology & Applied Microbiology SC Biochemistry & Molecular Biology; Biotechnology & Applied Microbiology GA XB483 UT WOS:A1997XB48300023 PM 18576085 ER PT J AU Baron, M Fontana, JD Guimaraes, MF Woodward, J AF Baron, M Fontana, JD Guimaraes, MF Woodward, J TI Stabilization and reutilization of Bacillus megaterium glucose dehydrogenase by immobilization SO APPLIED BIOCHEMISTRY AND BIOTECHNOLOGY LA English DT Article; Proceedings Paper CT 18th Symposium on Biotechnology for Fuels and Chemicals CY MAY 05-09, 1996 CL GATLINBURG, TN SP US DOE, Div Biofuels Energy Syst, US DOE, Biol & Chem Technol Res Program, Oak Ridge Natl Lab, Natl Renewable Energy Lab, Idaho Natl Lab, Lockheed Martin Energy Syst Inc, A E Staley Mfg Co, Archer Daniels Midland Co, Bio-Tech Resources L P, Chronopol Inc, ConAgra Grain Processing Co, Enzyme Bio-Syst Ltd, DuPont Co, Grain Processing Corp, Raphael Katzen Associates Int Inc, Weyerhaeuser Co, Amer Chem Soc, Div Biochem Technol DE Bacillus megaterium; glucose dehydrogenase; aminopropyl controlled-pore silica; DEAE-Sephadex; immobilization AB Glucose dehydrogenase (GDH) from Bacillus megaterium was immobilized using aminopropyl controlled-pore silica (CPS, average pore sizes of 170 and 500 Angstrom) as a support and glutaraldehyde as a bifunctional crosslinking agent. The CPS-immobilized enzyme could be reused 12 times and the best results were obtained using aminopropyl CPS-500 and bovine serum albumin as a feeder for stabilizing the protein layer on the support. DEAE-Sephadex (A-25 and A-50) was also used as a support for immobilizing GDH, with yields of around 42% for A-25 and 25-30% for A-50. The effect of pH on the immobilization procedure showed pH 6.5 to be better than pH 7.5 with respect to the recovery of enzyme activity. Both preparations of DEAE-Sephadex immobilized GDH could be reused several times and were thermostable at 40 degrees C for 7 h. The kinetic parameters as Michaelis constant and maximum rate were determined for the immobilized enzyme and compared with those for the freeform. C1 OAK RIDGE NATL LAB,OAK RIDGE,TN. RP Baron, M (reprint author), UNIV FED PARANA,DEPT BIOCHEM,BIOMASS CHEMO BIOTECHNOL LAB,POB 19046,BR-81531970 CURITIBA,PARANA,BRAZIL. NR 9 TC 6 Z9 6 U1 1 U2 2 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 SPR PY 1997 VL 63-5 BP 257 EP 268 DI 10.1007/BF02920429 PG 12 WC Biochemistry & Molecular Biology; Biotechnology & Applied Microbiology SC Biochemistry & Molecular Biology; Biotechnology & Applied Microbiology GA XB483 UT WOS:A1997XB48300024 PM 18576086 ER PT J AU Lawford, HG Rousseau, JD McMillan, JD AF Lawford, HG Rousseau, JD McMillan, JD TI Optimization of seed production for a simultaneous saccharification cofermentation biomass-to-ethanol process using recombinant Zymomonas SO APPLIED BIOCHEMISTRY AND BIOTECHNOLOGY LA English DT Article; Proceedings Paper CT 18th Symposium on Biotechnology for Fuels and Chemicals CY MAY 05-09, 1996 CL GATLINBURG, TN SP US DOE, Div Biofuels Energy Syst, US DOE, Biol & Chem Technol Res Program, Oak Ridge Natl Lab, Natl Renewable Energy Lab, Idaho Natl Lab, Lockheed Martin Energy Syst Inc, A E Staley Mfg Co, Archer Daniels Midland Co, Bio-Tech Resources L P, Chronopol Inc, ConAgra Grain Processing Co, Enzyme Bio-Syst Ltd, DuPont Co, Grain Processing Corp, Raphael Katzen Associates Int Inc, Weyerhaeuser Co, Amer Chem Soc, Div Biochem Technol DE recombinant Zymomonas; seed production via cofermentation of glucose and xylose; corn steep liquor; pH; acetic acid; synthetic hemicellulose hydrolyzate ID PENTOSE METABOLISM; MINIMAL MEDIUM; FUEL ETHANOL; MOBILIS; FERMENTATION; ALCOHOL; GROWTH; PH; LIGNOCELLULOSE; CONVERSION AB The five-carbon sugar D-xylose is a major component of hemicellulose and accounts for roughly one-third of the carbohydrate content of many lignocellulosic materials. The efficient fermentation of xylose-rich hemicellulose hydrolyzates (prehydrolyzates) represents an opportunity to improve significantly the economics of large-scale fuel ethanol production from lignocellulosic feedstocks. The National Renewable Energy Laboratory (NREL) is currently investigating a simultaneous saccharification and cofermentation (SSCF) process for ethanol production from biomass that uses a dilute-acid pretreatment and a metabolically engineered strain of Zymomonas mobilis that can coferment glucose and xylose. The objective of this study was to establish optimal conditions for cost-effective seed production that are compatible with the SSCF process design. Two-level and three-level full factorial experimental designs were employed to characterize efficiently the growth performance of recombinant Z. mobilis CP4:pZB5 as a function of nutrient level, pH, and acetic acid concentration using a synthetic hardwood hemicellulose hydrolyzate containing 4% (w/v) xylose and 0.8% (w/v) glucose. Fermentations were run batchwise and were pH-controlled at low levels of clarified corn steep liquor (cCSL, 1-2% v/v), which were used as the sole source of nutrients. For the purpose of assessing comparative fermentation performance, seed production was also carried out using a ''benchmark'' yeast extract-based laboratory medium. Analysis of variance (ANOVA) of experimental results was performed to determine the main effects and possible interactive effects of nutrient (cCSL) level, pH, and acetic acid concentration on the rate of xylose utilization and the extent of cell mass production. Results indicate that the concentration of acetic acid is the most significant Limiting factor for the xylose utilization rate and the extent of cell mass production; nutrient level and pH exerted weaker, but statistically significant effects. At pH 6.0, in the absence of acetic acid, the final cell mass concentration was 1.4 g dry cell mass/L (g DCM/L), but decreased to 0.92 and 0.64 g DCM/L in the presence of 0.5 and 1.0% (w/v) acetic acid, respectively. At concentrations of acetic acid of 0.75 (w/v) or lower, fermentation was complete within 1.5 d. In contrast, in the presence of 1.0% (w/v) acetic acid, 25% of the xylose remained after 2 d. At a volumetric supplementation level of 1.5-2.0% (v/v), cCSL proved to be a cost-effective single-source nutritional adjunct that can support growth and fermentation performance at levels comparable to those achieved using the expensive yeast extract-based laboratory reference medium. C1 NATL RENEWABLE ENERGY LAB,BIOTECHNOL CTR FUELS & CHEM,GOLDEN,CO 80401. RP Lawford, HG (reprint author), UNIV TORONTO,DEPT BIOCHEM,BIOENGN LAB,TORONTO,ON M5S 1A8,CANADA. NR 55 TC 25 Z9 25 U1 2 U2 6 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 SPR PY 1997 VL 63-5 BP 269 EP 286 DI 10.1007/BF02920430 PG 18 WC Biochemistry & Molecular Biology; Biotechnology & Applied Microbiology SC Biochemistry & Molecular Biology; Biotechnology & Applied Microbiology GA XB483 UT WOS:A1997XB48300025 PM 18576087 ER PT J AU Himmel, ME Karplus, PA Sakon, J Adney, WS Baker, JO Thomas, SR AF Himmel, ME Karplus, PA Sakon, J Adney, WS Baker, JO Thomas, SR TI Polysaccharide hydrolase folds diversity of structure and convergence of function SO APPLIED BIOCHEMISTRY AND BIOTECHNOLOGY LA English DT Article; Proceedings Paper CT 18th Symposium on Biotechnology for Fuels and Chemicals CY MAY 05-09, 1996 CL GATLINBURG, TN SP US DOE, Div Biofuels Energy Syst, US DOE, Biol & Chem Technol Res Program, Oak Ridge Natl Lab, Natl Renewable Energy Lab, Idaho Natl Lab, Lockheed Martin Energy Syst Inc, A E Staley Mfg Co, Archer Daniels Midland Co, Bio-Tech Resources L P, Chronopol Inc, ConAgra Grain Processing Co, Enzyme Bio-Syst Ltd, DuPont Co, Grain Processing Corp, Raphael Katzen Associates Int Inc, Weyerhaeuser Co, Amer Chem Soc, Div Biochem Technol DE cellulases; xylanases; amylases; glycosyl hydrolases; structural folds; X-ray structures; hydrophobic cluster families ID ACID-SEQUENCE SIMILARITIES; GLYCOSYL HYDROLASES; CRYSTAL-STRUCTURE; ACTIVE-SITE; TRICHODERMA-REESEI; GLOBULAR-PROTEINS; CELLOBIOHYDROLASE-I; CATALYTIC DOMAIN; ALPHA-AMYLASE; RESOLUTION AB Polysaccharide glycosyl hydrolases are a group of enzymes that hydrolyze the glycosidic bond between carbohydrates or between a carbohydrate and a noncarbohydrate moiety. Here we illustrate that traditional schemes for grouping enzymes, such as by substrate specificity or by organism of origin, are not appropriate when thinking of structure-function relationships and protein engineering. Instead, sequence comparisons and structural studies reveal that enzymes with diverse specificities and from diverse organisms can be placed into groups among which mechanisms are largely conserved and insights are likely to be transferrable. In particular, we illustrate how enzymes have been grouped using protein sequence alignment algorithms and hydrophobic cluster analysis. Unfortunately for those who seek to improve cellulase function by design, cellulases are distributed throughout glycosyl hydrolase Families 1,5,6,7,9, and 45. These cellulase families include members from widely different fold types, i.e., the TIM-barrel, beta alpha beta-barrel variant (a TIM-barrel-like structure that is imperfectly superimposable on the TIM-barrel template), beta-sandwich, and alpha-helix circular array. This diversity in cellulase fold structure must be taken into account when considering the transfer and application of design strategies between various cellulases. C1 CORNELL UNIV,BIOCHEM MOL & CELL BIOL SECT,ITHACA,NY 14853. RP Himmel, ME (reprint author), NATL RENEWABLE ENERGY LAB,BIOTECHNOL CTR RENEWABLE FUELS & CHEM,GOLDEN,CO 80401, USA. OI Sakon, Joshua/0000-0002-8373-969X NR 41 TC 11 Z9 11 U1 0 U2 1 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 SPR PY 1997 VL 63-5 BP 315 EP 325 DI 10.1007/BF02920433 PG 11 WC Biochemistry & Molecular Biology; Biotechnology & Applied Microbiology SC Biochemistry & Molecular Biology; Biotechnology & Applied Microbiology GA XB483 UT WOS:A1997XB48300028 PM 18576090 ER PT J AU Klasson, KT AF Klasson, KT TI Experimental data analysis - An algorithm for determining rates and smoothing data SO APPLIED BIOCHEMISTRY AND BIOTECHNOLOGY LA English DT Article; Proceedings Paper CT 18th Symposium on Biotechnology for Fuels and Chemicals CY MAY 05-09, 1996 CL GATLINBURG, TN SP US DOE, Div Biofuels Energy Syst, US DOE, Biol & Chem Technol Res Program, Oak Ridge Natl Lab, Natl Renewable Energy Lab, Idaho Natl Lab, Lockheed Martin Energy Syst Inc, A E Staley Mfg Co, Archer Daniels Midland Co, Bio-Tech Resources L P, Chronopol Inc, ConAgra Grain Processing Co, Enzyme Bio-Syst Ltd, DuPont Co, Grain Processing Corp, Raphael Katzen Associates Int Inc, Weyerhaeuser Co, Amer Chem Soc, Div Biochem Technol DE cubic splines; computer programming; derivatives; smoothing data AB Reaction rate determination from experimental data is generally an essential part of evaluating enzyme or microorganism growth kinetics and the effects on them. Commonly used methods include forward, centered, or backward finite difference equations using two or more data points. Another commonly applied method for determining rates is least-square regression techniques, and when the sought function is unknown, polynomials are often applied to represent the data. The cubic spline functions presented in this article represent a versatile method of evaluating rates. The advantage in using this method is that experimental error may be largely accounted for by the incorporation of a smoothing step of the experimental data without force-fitting of the data. It also works well when data are unevenly spaced (often the case for experiments running over long periods of time). The functions are easily manipulated, and the algorithm can be written concisely for computer programming. The development of spline functions to determine derivatives as well as integrals is presented. RP Klasson, KT (reprint author), OAK RIDGE NATL LAB,DIV CHEM TECHNOL,OAK RIDGE,TN 37831, USA. OI Klasson, K. Thomas/0000-0003-3358-3081 NR 5 TC 4 Z9 4 U1 0 U2 1 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 SPR PY 1997 VL 63-5 BP 339 EP 348 DI 10.1007/BF02920435 PG 10 WC Biochemistry & Molecular Biology; Biotechnology & Applied Microbiology SC Biochemistry & Molecular Biology; Biotechnology & Applied Microbiology GA XB483 UT WOS:A1997XB48300030 PM 18576092 ER PT J AU Dorsch, RR Hatzis, C AF Dorsch, RR Hatzis, C TI Bioprocessing research SO APPLIED BIOCHEMISTRY AND BIOTECHNOLOGY LA English DT Editorial Material C1 NATL RENEWABLE ENERGY LAB,GOLDEN,CO. RP Dorsch, RR (reprint author), DUPONT CO INC,WILMINGTON,DE, USA. RI Hatzis, Christos/M-3867-2015 OI Hatzis, Christos/0000-0002-8120-2290 NR 0 TC 0 Z9 0 U1 0 U2 0 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 SPR PY 1997 VL 63-5 BP 349 EP 349 DI 10.1007/BF02920436 PG 1 WC Biochemistry & Molecular Biology; Biotechnology & Applied Microbiology SC Biochemistry & Molecular Biology; Biotechnology & Applied Microbiology GA XB483 UT WOS:A1997XB48300031 PM 18576093 ER PT J AU Schmidt, SL Myers, MD Kelley, SS McMillan, JD Padukone, N AF Schmidt, SL Myers, MD Kelley, SS McMillan, JD Padukone, N TI Evaluation of PTMSP membranes in achieving enhanced ethanol removal from fermentations by pervaporation SO APPLIED BIOCHEMISTRY AND BIOTECHNOLOGY LA English DT Article; Proceedings Paper CT 18th Symposium on Biotechnology for Fuels and Chemicals CY MAY 05-09, 1996 CL GATLINBURG, TN SP US DOE, Div Biofuels Energy Syst, US DOE, Biol & Chem Technol Res Program, Oak Ridge Natl Lab, Natl Renewable Energy Lab, Idaho Natl Lab, Lockheed Martin Energy Syst Inc, A E Staley Mfg Co, Archer Daniels Midland Co, Bio-Tech Resources L P, Chronopol Inc, ConAgra Grain Processing Co, Enzyme Bio-Syst Ltd, DuPont Co, Grain Processing Corp, Raphael Katzen Associates Int Inc, Weyerhaeuser Co, Amer Chem Soc, Div Biochem Technol DE pervaporation; PTMSP; PDMS; ethanol recovery; membrane separations ID CHEMICAL MODIFICATION; RECOVERY; POLY(1-TRIMETHYLSILYL-1-PROPYNE); POLY(SUBSTITUTED-ACETYLENE); ALCOHOL AB The use of membrane processes for the recovery of fermentation products has been gaining increased acceptance in recent years. Pervaporation has been studied in the past as a process for simultaneous fermentation and recovery of volatile products such as ethanol and butanol. However, membrane fouling and low permeate fluxes have imposed limitations on the effectiveness of the process. In this study, we characterize the performance of a substituted polyacetylene membrane, poly[(1-trimethylsilyl)-1-propyne] (PTMSP), in the recovery of ethanol from aqueous mixtures and fermentation broths. Pervaporation using PTMSP membranes shows a distinct advantage over conventional poly(dimethyl siloxane) (PDMS) membranes in ethanol removal. The flux with PTMSP is about threefold higher and the concentration factor is about twofold higher than the corresponding performance achieved with PDMS under similar conditions. The performance of PTMSP with fermentation broths shows a reduction in both flux and concentration factor relative to ethanol-water mixtures. However, the PTMSP membranes indicate initial promise of increased fouling resistance in operation with cell-containing fermentation broths. C1 NATL RENEWABLE ENERGY LAB,GOLDEN,CO 80401. NR 35 TC 29 Z9 30 U1 0 U2 15 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 SPR PY 1997 VL 63-5 BP 469 EP 482 DI 10.1007/BF02920447 PG 14 WC Biochemistry & Molecular Biology; Biotechnology & Applied Microbiology SC Biochemistry & Molecular Biology; Biotechnology & Applied Microbiology GA XB483 UT WOS:A1997XB48300042 PM 18576104 ER PT J AU Sun, MY Bienkowski, PR Davison, BH Spurrier, MA Webb, OF AF Sun, MY Bienkowski, PR Davison, BH Spurrier, MA Webb, OF TI Performance of coimmobilized yeast and amyloglucosidase in a fluidized bed reactor for fuel ethanol production SO APPLIED BIOCHEMISTRY AND BIOTECHNOLOGY LA English DT Article; Proceedings Paper CT 18th Symposium on Biotechnology for Fuels and Chemicals CY MAY 05-09, 1996 CL GATLINBURG, TN SP US DOE, Div Biofuels Energy Syst, US DOE, Biol & Chem Technol Res Program, Oak Ridge Natl Lab, Natl Renewable Energy Lab, Idaho Natl Lab, Lockheed Martin Energy Syst Inc, A E Staley Mfg Co, Archer Daniels Midland Co, Bio-Tech Resources L P, Chronopol Inc, ConAgra Grain Processing Co, Enzyme Bio-Syst Ltd, DuPont Co, Grain Processing Corp, Raphael Katzen Associates Int Inc, Weyerhaeuser Co, Amer Chem Soc, Div Biochem Technol DE ethanol; glucose; starch; simultaneous saccharification and fermentation; fluidized-bed reactor ID ZYMOMONAS-MOBILIS; BIOREACTOR; SACCHARIFICATION; FERMENTATION; CELLS AB The performance of coimmobilized Saccharomyces cerevisiae and amyloglucosidase (AG) was evaluated in a fluidized-bed reactor. Soluble starch and yeast extracts were used as feed stocks. Conversion of soluble starch streams to ethanol has potential practical applications in corn dry and wet milling and in developmental lignocellulosic processes. The bio-catalyst performed well, and demonstrated no significant loss of activity or physical integrity during 10 wk of continuous operation. The reactor was easily operated and required no pH control. No operational problems were encountered from bacterial contaminants even though the reactor was operated under nonsterile conditions over the entire course of experiments. Productivities ranged between 25 and 44 g ethanol/L/h/. The experiments demonstrated that ethanol inhibition and bed loading had significant effects on reactor performance. C1 OAK RIDGE NATL LAB,DIV CHEM TECHNOL,OAK RIDGE,TN 37831. UNIV TENNESSEE,DEPT CHEM ENGN,KNOXVILLE,TN 37916. RI Davison, Brian/D-7617-2013 OI Davison, Brian/0000-0002-7408-3609 NR 16 TC 4 Z9 5 U1 0 U2 1 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 SPR PY 1997 VL 63-5 BP 483 EP 493 DI 10.1007/BF02920448 PG 11 WC Biochemistry & Molecular Biology; Biotechnology & Applied Microbiology SC Biochemistry & Molecular Biology; Biotechnology & Applied Microbiology GA XB483 UT WOS:A1997XB48300043 PM 9170248 ER PT J AU Nghiem, NP Davison, BH Suttle, BE Richardson, GR AF Nghiem, NP Davison, BH Suttle, BE Richardson, GR TI Production of succinic acid by Anaerobiospirillum succiniciproducens SO APPLIED BIOCHEMISTRY AND BIOTECHNOLOGY LA English DT Article; Proceedings Paper CT 18th Symposium on Biotechnology for Fuels and Chemicals CY MAY 05-09, 1996 CL GATLINBURG, TN SP US DOE, Div Biofuels Energy Syst, US DOE, Biol & Chem Technol Res Program, Oak Ridge Natl Lab, Natl Renewable Energy Lab, Idaho Natl Lab, Lockheed Martin Energy Syst Inc, A E Staley Mfg Co, Archer Daniels Midland Co, Bio-Tech Resources L P, Chronopol Inc, ConAgra Grain Processing Co, Enzyme Bio-Syst Ltd, DuPont Co, Grain Processing Corp, Raphael Katzen Associates Int Inc, Weyerhaeuser Co, Amer Chem Soc, Div Biochem Technol DE succinic acid; fermentation; renewable resources; corn sugars; Anaerobiospirillum succiniciproducens ID PH AB The effect of an external supply of carbon dioxide and pH on the production of succinic acid by Anaerobiospirillum succiniciproducens was studied. In a rich medium containing yeast extract and peptone, when the external carbon dioxide supply was provided by a 1.5M 1 Na2CO3 solution that also was used to maintain the pH at 6.0, no additional carbon dioxide supply was needed. In fact, sparging CO2 gas into the fermenter at 0.025 L/L-min or higher rates resulted in significant decreases in both production rate and yield of succinate. Under the same conditions, the production of the main by-product acetate was not affected by sparging CO2 gas into the fermenter. The optimum pH (pH 6.0) for the production of succinic acid was found to be in agreement with results previously reported in the literature. Succinic acid production also was studied in an industrial-type inexpensive medium in which light steep water was the only source of organic nutrients. At pH 6.0 and with a CO2 gas sparge rate of 0.08 L/L-min, succinate concentration reached a maximum of 32 g/L in 27 h with a yield of 0.99 g succinate/g glucose consumed. RP Nghiem, NP (reprint author), OAK RIDGE NATL LAB,DIV CHEM TECHNOL,POB 2008,MS-6226,OAK RIDGE,TN 37831, USA. RI Davison, Brian/D-7617-2013 OI Davison, Brian/0000-0002-7408-3609 NR 15 TC 47 Z9 51 U1 3 U2 7 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 SPR PY 1997 VL 63-5 BP 565 EP 576 DI 10.1007/BF02920454 PG 12 WC Biochemistry & Molecular Biology; Biotechnology & Applied Microbiology SC Biochemistry & Molecular Biology; Biotechnology & Applied Microbiology GA XB483 UT WOS:A1997XB48300049 PM 18576111 ER PT J AU Markov, SA Weaver, PF Seibert, M AF Markov, SA Weaver, PF Seibert, M TI Spiral tubular bioreactors for hydrogen production by photosynthetic microorganisms - Design and operation SO APPLIED BIOCHEMISTRY AND BIOTECHNOLOGY LA English DT Article; Proceedings Paper CT 18th Symposium on Biotechnology for Fuels and Chemicals CY MAY 05-09, 1996 CL GATLINBURG, TN SP US DOE, Div Biofuels Energy Syst, US DOE, Biol & Chem Technol Res Program, Oak Ridge Natl Lab, Natl Renewable Energy Lab, Idaho Natl Lab, Lockheed Martin Energy Syst Inc, A E Staley Mfg Co, Archer Daniels Midland Co, Bio-Tech Resources L P, Chronopol Inc, ConAgra Grain Processing Co, Enzyme Bio-Syst Ltd, DuPont Co, Grain Processing Corp, Raphael Katzen Associates Int Inc, Weyerhaeuser Co, Amer Chem Soc, Div Biochem Technol DE hydrogen; bioreactors; Anabaena variabilis; water-gas shift reaction; Rhodobacter ID MASS CULTIVATION; PHOTOBIOREACTOR; PERFORMANCE AB Spiral tubular bioreactors were constructed out of transparent PVC tubing for H-2 production applications. Both a cyanobacterial Anabaena variabilis mutant that lacks uptake hydrogenase activity and the photosynthetic bacterium Rhodobacter sp. CBS were tested in the bioreactors. Continuous H-2 photoproduction at an average rate of 19 mL . min(-2) . h(-1) was observed using the A. variabilis mutant under an air atmosphere (without argon sparging or application of a partial vacuum). The cyanobacterial photobioreactor was run continuously for over one month with an average efficiency of light energy conversion to H-2 of 1.4%. Another H-2-producing approach employed a unique type of activity found in a strain of photosynthetic bacteria that shifts CO (and H2O) into H-2 (and CO2) in darkness. Continuous dark H-2 production by Rhodobacter sp. CBS from CO (in anticipation of using synthesis gas as the future substrate) at rates up to 140 mL . g cdw(-1) . h(-1) was observed in a bubble-train bioreactor for more than 10 d. RP Markov, SA (reprint author), NATL RENEWABLE ENERGY LAB,1617 COLE BLVD,GOLDEN,CO 80401, USA. NR 14 TC 14 Z9 16 U1 0 U2 1 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 SPR PY 1997 VL 63-5 BP 577 EP 584 DI 10.1007/BF02920455 PG 8 WC Biochemistry & Molecular Biology; Biotechnology & Applied Microbiology SC Biochemistry & Molecular Biology; Biotechnology & Applied Microbiology GA XB483 UT WOS:A1997XB48300050 PM 18576112 ER PT J AU Baker, JO Vinzant, TB Ehrman, CI Adney, WS Himmel, ME AF Baker, JO Vinzant, TB Ehrman, CI Adney, WS Himmel, ME TI Use of a new membrane-reactor saccharification assay to evaluate the performance of cellulases under simulated SSF conditions - Effect on enzyme quality of growing Trichoderma reesei in the presence of targeted lignocellulosic substrate SO APPLIED BIOCHEMISTRY AND BIOTECHNOLOGY LA English DT Article; Proceedings Paper CT 18th Symposium on Biotechnology for Fuels and Chemicals CY MAY 05-09, 1996 CL GATLINBURG, TN SP US DOE, Div Biofuels Energy Syst, US DOE, Biol & Chem Technol Res Program, Oak Ridge Natl Lab, Natl Renewable Energy Lab, Idaho Natl Lab, Lockheed Martin Energy Syst Inc, A E Staley Mfg Co, Archer Daniels Midland Co, Bio-Tech Resources L P, Chronopol Inc, ConAgra Grain Processing Co, Enzyme Bio-Syst Ltd, DuPont Co, Grain Processing Corp, Raphael Katzen Associates Int Inc, Weyerhaeuser Co, Amer Chem Soc, Div Biochem Technol DE cellulase digestion; Trichoderma reesei; pretreated hardwood; diafiltration saccharification; membrane reactor ID HYDROLYSIS; INHIBITION; CELLULOSE; BIOMASS; VIRIDE AB A new saccharification assay has been devised; in which a continuously buffer-swept membrane reactor is used to remove the solubilized saccharification products, thus allowing high extents of substrate conversion without significant inhibitory effects from the buildup of either cellobiose or glucose. This diafiltration saccharification assay (DSA) can, therefore, be used to obtain direct measurements of the performance of combinations of cellulase and substrate under simulated SSF conditions, without the saccharification results being complicated by factors that may influence the subsequent fermentation step. This assay has been used to compare the effectiveness of commercial and special in-house produced Trichoderma reesei cellulase preparations in the saccharification of a standardized microcrystalline (Sigmacell) substrate and a dilute-acid pretreated lignocellulosic substrate. Initial results strongly suggest that enzyme preparations produced in the presence of the targeted lignocellulosic substrate will saccharify that substrate more effectively. These results call into question the widespread use of the ''filter paper assay'' as a reliable predictor of enzyme performance in the extensive hydrolysis of substrates that are quite different from filter paper in both physical properties and chemical composition. RP Baker, JO (reprint author), NATL RENEWABLE ENERGY LAB,BIOTECHNOL CTR FUELS & CHEM,ENZYME TECHNOL TEAM,GOLDEN,CO, USA. NR 14 TC 15 Z9 15 U1 0 U2 0 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 SPR PY 1997 VL 63-5 BP 585 EP 595 DI 10.1007/BF02920456 PG 11 WC Biochemistry & Molecular Biology; Biotechnology & Applied Microbiology SC Biochemistry & Molecular Biology; Biotechnology & Applied Microbiology GA XB483 UT WOS:A1997XB48300051 PM 18576113 ER PT J AU Hinman, ND Yancey, MA AF Hinman, ND Yancey, MA TI Net present value analysis to select public R&D programs and valuate expected private sector participation SO APPLIED BIOCHEMISTRY AND BIOTECHNOLOGY LA English DT Article; Proceedings Paper CT 18th Symposium on Biotechnology for Fuels and Chemicals CY MAY 05-09, 1996 CL GATLINBURG, TN SP US DOE, Div Biofuels Energy Syst, US DOE, Biol & Chem Technol Res Program, Oak Ridge Natl Lab, Natl Renewable Energy Lab, Idaho Natl Lab, Lockheed Martin Energy Syst Inc, A E Staley Mfg Co, Archer Daniels Midland Co, Bio-Tech Resources L P, Chronopol Inc, ConAgra Grain Processing Co, Enzyme Bio-Syst Ltd, DuPont Co, Grain Processing Corp, Raphael Katzen Associates Int Inc, Weyerhaeuser Co, Amer Chem Soc, Div Biochem Technol DE investment analysis; net present value; R&D; public/private partnerships AB One of the main functions of government is to invest taxpayer dollars in projects, programs, and properties that will result in social benefit. Public programs focused on the development of technology are examples of such opportunities. Selecting these programs requires the same investment analysis approaches that private companies and individuals use. Good use of investment analysis approaches to these programs will minimize our tax costs and maximize public benefit from tax dollars invested. This article describes the use of the net present value (NPV) analysis approach to select public R&D programs and valuate expected private sector participation in the programs. RP Hinman, ND (reprint author), NATL RENEWABLE ENERGY LAB,CTR RENEWABLE FUELS & BIOTECHNOL,GOLDEN,CO 80401, USA. NR 5 TC 0 Z9 0 U1 0 U2 0 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 SPR PY 1997 VL 63-5 BP 599 EP 607 DI 10.1007/BF02920458 PG 9 WC Biochemistry & Molecular Biology; Biotechnology & Applied Microbiology SC Biochemistry & Molecular Biology; Biotechnology & Applied Microbiology GA XB483 UT WOS:A1997XB48300053 PM 18576115 ER PT J AU Dale, BE Kaufman, EN AF Dale, BE Kaufman, EN TI Emerging topics in industrial biotechnology SO APPLIED BIOCHEMISTRY AND BIOTECHNOLOGY LA English DT Editorial Material C1 OAK RIDGE NATL LAB,OAK RIDGE,TN. RP Dale, BE (reprint author), MICHIGAN STATE UNIV,E LANSING,MI 48824, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 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 SPR PY 1997 VL 63-5 BP 625 EP 626 DI 10.1007/BF02920460 PG 2 WC Biochemistry & Molecular Biology; Biotechnology & Applied Microbiology SC Biochemistry & Molecular Biology; Biotechnology & Applied Microbiology GA XB483 UT WOS:A1997XB48300055 PM 18576117 ER PT J AU Beck, MJ Barnes, JM AF Beck, MJ Barnes, JM TI Environmental biotechnology SO APPLIED BIOCHEMISTRY AND BIOTECHNOLOGY LA English DT Editorial Material C1 IDAHO NATL ENGN LAB,IDAHO FALLS,ID 83415. RP Beck, MJ (reprint author), TENNESSEE VALLEY AUTHOR,MUSCLE SHOALS,AL 35660, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 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 SPR PY 1997 VL 63-5 BP 667 EP 667 DI 10.1007/BF02920465 PG 1 WC Biochemistry & Molecular Biology; Biotechnology & Applied Microbiology SC Biochemistry & Molecular Biology; Biotechnology & Applied Microbiology GA XB483 UT WOS:A1997XB48300060 PM 18576122 ER PT J AU Kaufman, EN Little, MH Selvaraj, PT AF Kaufman, EN Little, MH Selvaraj, PT TI A biological process for the reclamation of flue gas desulfurization gypsum using mixed sulfate-reducing bacteria with inexpensive carbon sources SO APPLIED BIOCHEMISTRY AND BIOTECHNOLOGY LA English DT Article; Proceedings Paper CT 18th Symposium on Biotechnology for Fuels and Chemicals CY MAY 05-09, 1996 CL GATLINBURG, TN SP US DOE, Div Biofuels Energy Syst, US DOE, Biol & Chem Technol Res Program, Oak Ridge Natl Lab, Natl Renewable Energy Lab, Idaho Natl Lab, Lockheed Martin Energy Syst Inc, A E Staley Mfg Co, Archer Daniels Midland Co, Bio-Tech Resources L P, Chronopol Inc, ConAgra Grain Processing Co, Enzyme Bio-Syst Ltd, DuPont Co, Grain Processing Corp, Raphael Katzen Associates Int Inc, Weyerhaeuser Co, Amer Chem Soc, Div Biochem Technol DE gypsum sludge; sulfate-reducing bacteria; synthesis gas; sulfur; calcium carbonate; flue gas desulfurization ID MICROBIAL REDUCTION; SULFUR-DIOXIDE; HYDROGEN; REMOVAL; SLUDGE; ENERGY AB A combined chemical and biological process for the recycling of flue gas desulfurization (FGD) gypsum into calcium carbonate and elemental sulfur is demonstrated. In this process, a mixed culture of sulfate-reducing bacteria (SRB) utilizes inexpensive carbon sources, such as sewage digest or synthesis gas, to reduce FGD gypsum to hydrogen sulfide. The sulfide is then oxidized to elemental sulfur via reaction with ferric sulfate, and accumulating calcium ions are precipitated as calcium carbonate using carbon dioxide. Employing anaerobically digested municipal sewage sludge (AD-MSS) medium as a carbon source, SRBs in serum bottles demonstrated an FGD gypsum reduction rate of 8 mg/L/h (10(9) cells)(-1). A chemostat with continuous addition of both AD-MSS media and gypsum exhibited sulfate reduction rates as high as 1.3 kg FGD gypsum/m(3) d. The increased biocatalyst density afforded by cell immobilization in a columnar reactor allowed a productivity of 152 mg SO4-2/L.h or 6.6 kg FGD gypsum/m(3).d. Both reactors demonstrated 100% conversion of sulfate, with 75-100% recovery of elemental sulfur and chemical oxygen demand utilization as high as 70%. Calcium carbonate was recovered from the reactor effluent on precipitation using carbon dioxide. It was demonstrated that SRBs may also use synthesis gas (CO, H-2, and CO2) in the reduction of gypsum, further decreasing process costs. The formation of two marketable products-elemental sulfur and calcium carbonate-from FGD gypsum sludge, combined with the use of a low-cost carbon source and further improvements in reactor design, promises to offer an attractive alternative to the landfilling of FGD gypsum. RP Kaufman, EN (reprint author), OAK RIDGE NATL LAB,DIV CHEM TECHNOL,BIOPROC RES & DEV CTR,OAK RIDGE,TN 37831, USA. NR 33 TC 8 Z9 8 U1 2 U2 13 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 SPR PY 1997 VL 63-5 BP 677 EP 693 DI 10.1007/BF02920467 PG 17 WC Biochemistry & Molecular Biology; Biotechnology & Applied Microbiology SC Biochemistry & Molecular Biology; Biotechnology & Applied Microbiology GA XB483 UT WOS:A1997XB48300062 PM 18576124 ER PT J AU Pfiffner, SM Palumbo, AV Gibson, T Ringelberg, DB McCarthy, JF AF Pfiffner, SM Palumbo, AV Gibson, T Ringelberg, DB McCarthy, JF TI Relating ground water and sediment chemistry to microbial characterization at a BTEX-contaminated site SO APPLIED BIOCHEMISTRY AND BIOTECHNOLOGY LA English DT Article; Proceedings Paper CT 18th Symposium on Biotechnology for Fuels and Chemicals CY MAY 05-09, 1996 CL GATLINBURG, TN SP US DOE, Div Biofuels Energy Syst, US DOE, Biol & Chem Technol Res Program, Oak Ridge Natl Lab, Natl Renewable Energy Lab, Idaho Natl Lab, Lockheed Martin Energy Syst Inc, A E Staley Mfg Co, Archer Daniels Midland Co, Bio-Tech Resources L P, Chronopol Inc, ConAgra Grain Processing Co, Enzyme Bio-Syst Ltd, DuPont Co, Grain Processing Corp, Raphael Katzen Associates Int Inc, Weyerhaeuser Co, Amer Chem Soc, Div Biochem Technol DE microbial characterization; BTEX or petroleum hydrocarbon; bioremediation; subsurface; ground water; oxygen injection; nitrate injection ID SULFATE-REDUCING BACTERIA; FATTY-ACID PROFILES; COASTAL-PLAIN; BIODEGRADATION; MICROORGANISMS; SOIL AB The National Center for Manufacturing Science is investigating bioremediation of petroleum hydrocarbon at a Site near Belleville, MI. As part of this study, we examined the microbial communities to help elucidate biodegradative processes currently active at the site. We observed high densities of aerobic hydrocarbon degraders and denitrifiers in the less-contaminated sediments. Low densities of iron and sulfate reducers were measured in the same sediments. In contrast, the highly contaminated sediments showed low densities of aerobic hydrocarbon degraders and denitrifiers, and high densities of iron and sulfate reducers. Methanogens were also found in these highly contaminated sediments. These contaminated sediments also showed a higher biomass, by the phospholipid fatty acids, and greater ratios of phospholipid fatty acids, which indicate stress within the microbial community. Aquifer chemistry analyses indicated that the highly contaminated area was more reduced and had lower sulfate than the less-contaminated area. These conditions suggest that the subsurface environment at the highly contaminated area had progressed into sulfate reduction and methanogenesis. The less-contaminated area, although less reduced, also appeared to be progressing into primarily iron- and sulfate-reducing microbial communities. The proposed treatment to stimulate bioremediation includes addition of oxygen and nitrate to the subsurface. Ground water chemistry and microbial analyses revealed significant differences that resulted from the injection of dissolved oxygen and nitrate. These differences included an increase in Eh, small decrease in pH, and large decreases in BTEX, dissolved iron, and sulfate concentrations at the injection well. Injected nitrate was rapidly utilized by the subsurface microbial communities, and significant nitrite amounts were observed in the injection well and in nearby down-gradient observation wells. Microbial and molecular analyses indicated an increase in denitrifying bacteria after nitrate injection. The activity and population of denitrifying bacteria were significantly increased at the injection well relative to a down-gradient well for as long as 2 mo after the nitrate injection ended. C1 OAK RIDGE NATL LAB, DIV ENVIRONM SCI, OAK RIDGE, TN 37831 USA. GM CORP, CTR RES & DEV, WARREN, MI 48090 USA. UNIV TENNESSEE, CTR ENVIRONM BIOTECHNOL, KNOXVILLE, TN 37932 USA. RI Palumbo, Anthony/A-4764-2011 OI Palumbo, Anthony/0000-0002-1102-3975 NR 24 TC 19 Z9 20 U1 0 U2 4 PU HUMANA PRESS INC PI TOTOWA PA 999 RIVERVIEW DRIVE SUITE 208, TOTOWA, NJ 07512 USA SN 0273-2289 J9 APPL BIOCHEM BIOTECH JI Appl. Biochem. Biotechnol. PD SPR PY 1997 VL 63-5 BP 775 EP 788 DI 10.1007/BF02920474 PG 14 WC Biochemistry & Molecular Biology; Biotechnology & Applied Microbiology SC Biochemistry & Molecular Biology; Biotechnology & Applied Microbiology GA XB483 UT WOS:A1997XB48300069 PM 18576131 ER PT J AU Palumbo, AV StrongGunderson, JM Carroll, S AF Palumbo, AV StrongGunderson, JM Carroll, S TI Retaining and recovering enzyme activity during degradation of TCE by methanotrophs SO APPLIED BIOCHEMISTRY AND BIOTECHNOLOGY LA English DT Article; Proceedings Paper CT 18th Symposium on Biotechnology for Fuels and Chemicals CY MAY 05-09, 1996 CL GATLINBURG, TN SP US DOE, Div Biofuels Energy Syst, US DOE, Biol & Chem Technol Res Program, Oak Ridge Natl Lab, Natl Renewable Energy Lab, Idaho Natl Lab, Lockheed Martin Energy Syst Inc, A E Staley Mfg Co, Archer Daniels Midland Co, Bio-Tech Resources L P, Chronopol Inc, ConAgra Grain Processing Co, Enzyme Bio-Syst Ltd, DuPont Co, Grain Processing Corp, Raphael Katzen Associates Int Inc, Weyerhaeuser Co, Amer Chem Soc, Div Biochem Technol DE TCE; methanotrophs; biodegradation; enzyme activity; formate ID METHYLOSINUS-TRICHOSPORIUM OB3B; TRICHLOROETHYLENE DEGRADATION; METHANE; BIODEGRADATION; TOXICITY; ENRICHMENT; METABOLISM; BACTERIUM; CULTURES AB To determine if compounds added during trichloroethylene (TCE) degradation could reduce the loss of enzyme activity or increase enzyme recovery, different compounds serving as energy and carbon sources, pH buffers, or free radical scavengers were tested. Formate and formic acid (reducing power and a carbon source), as well as ascorbic acid and citric acid (free radical scavengers) were added during TCE degradation at a concentration of 2 mM. A saturated solution of calcium carbonate was also tested to address pH concerns. In the presence of formate and methane, only calcium carbonate and formic acid had a beneficial effect on enzyme recovery. The calcium carbonate and formic acid both reduced the loss of enzyme activity and resulted in the highest levels of enzyme activity after recovery. RP Palumbo, AV (reprint author), OAK RIDGE NATL LAB,DIV ENVIRONM SCI,POB 2008,OAK RIDGE,TN 37831, USA. RI Palumbo, Anthony/A-4764-2011 OI Palumbo, Anthony/0000-0002-1102-3975 NR 19 TC 0 Z9 0 U1 0 U2 0 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 SPR PY 1997 VL 63-5 BP 789 EP 796 DI 10.1007/BF02920475 PG 8 WC Biochemistry & Molecular Biology; Biotechnology & Applied Microbiology SC Biochemistry & Molecular Biology; Biotechnology & Applied Microbiology GA XB483 UT WOS:A1997XB48300070 PM 18576132 ER PT J AU Zhang, CL Lehman, RM Pfiffner, SM Scarborough, SP Palumbo, AV Phelps, TJ Beauchamp, JJ Colwell, FS AF Zhang, CL Lehman, RM Pfiffner, SM Scarborough, SP Palumbo, AV Phelps, TJ Beauchamp, JJ Colwell, FS TI Spatial and temporal variations of microbial properties at different scales in shallow subsurface sediments SO APPLIED BIOCHEMISTRY AND BIOTECHNOLOGY LA English DT Article; Proceedings Paper CT 18th Symposium on Biotechnology for Fuels and Chemicals CY MAY 05-09, 1996 CL GATLINBURG, TN SP US DOE, Div Biofuels Energy Syst, US DOE, Biol & Chem Technol Res Program, Oak Ridge Natl Lab, Natl Renewable Energy Lab, Idaho Natl Lab, Lockheed Martin Energy Syst Inc, A E Staley Mfg Co, Archer Daniels Midland Co, Bio-Tech Resources L P, Chronopol Inc, ConAgra Grain Processing Co, Enzyme Bio-Syst Ltd, DuPont Co, Grain Processing Corp, Raphael Katzen Associates Int Inc, Weyerhaeuser Co, Amer Chem Soc, Div Biochem Technol DE aerobic culturable heterotrophs; glucose mineralization rates; community-level physiological profile; seasonal variation; sampling scale effects; water availability ID AQUIFER; COMMUNITIES; BIODEGRADATION; MICROORGANISMS; DIVERSITY; BACTERIA; CARBON; ADAPTATION; ABUNDANCE; PRISTINE AB Microbial abundance, activity, and community-level physiological profiles (CLPP) were examined at centimeter and meter scales in the subsurface environment at a site near Oyster, VA. At the centimeter scale, variations in aerobic culturable heterotrophs (AGH) and glucose mineralization rates (GMR) were highest in the water table zone, indicating that water availability has a major effect: on variations in microbial abundance and activity. At the meter scale, ACH and microaerophiles decreased significantly with depth, whereas anaerobic GMR often increased with depth; this may indicate low redox potentials at depth caused by microbial consumption of oxygen. Data of CLPP indicated that the microbial community (MC) in the soybean field exhibited greater capability to utilize multiple carbon sources than MC in the corn field. This difference may reflect nutrient availability associated with different crops (soybean vs corn). By using a regression model, significant spatial and temporal variations were observed for AGH, microaerophiles, anaerobic GMR, and CLPP. Results of this study indicated that water and nutrient availability as well as land use could have a dominant effect on spatial and temporal variations in microbial properties in shallow subsurface environments. C1 OAK RIDGE NATL LAB,OAK RIDGE,TN 37831. IDAHO NATL ENGN LAB,IDAHO FALLS,ID 83415. RI Palumbo, Anthony/A-4764-2011; phelps, tommy/A-5244-2011 OI Palumbo, Anthony/0000-0002-1102-3975; NR 31 TC 12 Z9 13 U1 0 U2 4 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 SPR PY 1997 VL 63-5 BP 797 EP 808 DI 10.1007/BF02920476 PG 12 WC Biochemistry & Molecular Biology; Biotechnology & Applied Microbiology SC Biochemistry & Molecular Biology; Biotechnology & Applied Microbiology GA XB483 UT WOS:A1997XB48300071 PM 18576133 ER PT J AU Gillespie, MT StrongGunderson, JM AF Gillespie, MT StrongGunderson, JM TI Effects of a nutrient-surfactant compound on solubilization rates of TCE SO APPLIED BIOCHEMISTRY AND BIOTECHNOLOGY LA English DT Article; Proceedings Paper CT 18th Symposium on Biotechnology for Fuels and Chemicals CY MAY 05-09, 1996 CL GATLINBURG, TN SP US DOE, Div Biofuels Energy Syst, US DOE, Biol & Chem Technol Res Program, Oak Ridge Natl Lab, Natl Renewable Energy Lab, Idaho Natl Lab, Lockheed Martin Energy Syst Inc, A E Staley Mfg Co, Archer Daniels Midland Co, Bio-Tech Resources L P, Chronopol Inc, ConAgra Grain Processing Co, Enzyme Bio-Syst Ltd, DuPont Co, Grain Processing Corp, Raphael Katzen Associates Int Inc, Weyerhaeuser Co, Amer Chem Soc, Div Biochem Technol DE TCE; degradation; surfactants; enzyme; biodegradable ID TRICHLOROETHYLENE; REMEDIATION AB BioTreat(TM), a commercially available nutrient-surfactant compound, was investigated for its ability to solubilize TCE. Potential mechanisms for enhancing biodegradation rates by the use of nutrient-surfactant mixtures are: increased solubilization of TCE into the aqueous phase, and increased nutrients for the bacteria and greater numbers of colony forming units (CFUs). Ln aqueous systems, no measured solubilization of 0.1 and 1.0 ppm TCE from the headspace into the liquid phase was observed with BioTreat added at concentrations <0.5%. However, at BioTreat concentrations in excess of the CMC (greater than or equal to 0.5%), increased solubilization of TCE was measured. A second question was the nutrient effect of BioTreat on the growth of the TCE-degrading bacterium, Burkholderia cepacia G4 PR1(301). The added nutrients provided by BioTreat was evident and lead to increased cell numbers. The effect of BioTreat on the expression of ortho-monooxgenase, the enzyme necessary for TCE degradation by B. cepacia was also investigated. Enzyme expression as detected by a colorimetric assay was inhibited for BioTreat concentrations >0.05%. C1 OAK RIDGE NATL LAB, OAK RIDGE, TN 37831 USA. NR 17 TC 0 Z9 0 U1 0 U2 0 PU HUMANA PRESS INC PI TOTOWA PA 999 RIVERVIEW DRIVE SUITE 208, TOTOWA, NJ 07512 USA SN 0273-2289 J9 APPL BIOCHEM BIOTECH JI Appl. Biochem. Biotechnol. PD SPR PY 1997 VL 63-5 BP 835 EP 843 DI 10.1007/BF02920479 PG 9 WC Biochemistry & Molecular Biology; Biotechnology & Applied Microbiology SC Biochemistry & Molecular Biology; Biotechnology & Applied Microbiology GA XB483 UT WOS:A1997XB48300074 PM 18576136 ER PT J AU Schmieman, EA Petersen, JN Yonge, DR Johnstone, DL BerededSamuel, Y Apel, WA Turick, CE AF Schmieman, EA Petersen, JN Yonge, DR Johnstone, DL BerededSamuel, Y Apel, WA Turick, CE TI Bacterial reduction of chromium SO APPLIED BIOCHEMISTRY AND BIOTECHNOLOGY LA English DT Article; Proceedings Paper CT 18th Symposium on Biotechnology for Fuels and Chemicals CY MAY 05-09, 1996 CL GATLINBURG, TN SP US DOE, Div Biofuels Energy Syst, US DOE, Biol & Chem Technol Res Program, Oak Ridge Natl Lab, Natl Renewable Energy Lab, Idaho Natl Lab, Lockheed Martin Energy Syst Inc, A E Staley Mfg Co, Archer Daniels Midland Co, Bio-Tech Resources L P, Chronopol Inc, ConAgra Grain Processing Co, Enzyme Bio-Syst Ltd, DuPont Co, Grain Processing Corp, Raphael Katzen Associates Int Inc, Weyerhaeuser Co, Amer Chem Soc, Div Biochem Technol DE bioremediation; chromium; chromium-reduction; chromium-tolerance; chromate; mixed culture; diversity AB A mixed culture was enriched from surface soil obtained from an eastern United States site highly contaminated with chromate. Growth of the culture was inhibited by a chromium concentration of 12 mg/L. Another mixed culture was enriched from subsurface soil obtained from the Hanford reservation, at the fringe of a chromate plume. The enrichment medium was minimal salts solution augmented with acetate as the carbon source, nitrate as the terminal electron acceptor, and various levels of chromate. This mixed culture exhibited chromate tolerance, but not chromate reduction capability, when growing anaerobically on this medium. However, this culture did exhibit chromate reduction capability when growing anaerobically on TSB. Growth of this culture was not inhibited by a chromium concentration of 12 mg/L. Mixed cultures exhibited decreasing diversity with increasing levels of chromate in the enrichment medium. An in situ bioremediation strategy is suggested for chromate contaminated soil and groundwater. C1 WASHINGTON STATE UNIV,DEPT CHEM ENGN,PULLMAN,WA 99164. WASHINGTON STATE UNIV,DEPT CIVIL & ENVIRONM ENGN,PULLMAN,WA 99164. IDAHO NATL ENGN & ENVIRONM LAB,CTR IND BIOTECHNOL,IDAHO FALLS,ID. RI Petersen, James/B-8924-2008 NR 16 TC 8 Z9 12 U1 0 U2 2 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 SPR PY 1997 VL 63-5 BP 855 EP 864 DI 10.1007/BF02920481 PG 10 WC Biochemistry & Molecular Biology; Biotechnology & Applied Microbiology SC Biochemistry & Molecular Biology; Biotechnology & Applied Microbiology GA XB483 UT WOS:A1997XB48300076 PM 18576138 ER PT J AU Turick, CE Camp, CE Apel, WA AF Turick, CE Camp, CE Apel, WA TI Reduction of Cr(6(+)) to Cr(3(+)) in a packed-bed bioreactor SO APPLIED BIOCHEMISTRY AND BIOTECHNOLOGY LA English DT Article; Proceedings Paper CT 18th Symposium on Biotechnology for Fuels and Chemicals CY MAY 05-09, 1996 CL GATLINBURG, TN SP US DOE, Div Biofuels Energy Syst, US DOE, Biol & Chem Technol Res Program, Oak Ridge Natl Lab, Natl Renewable Energy Lab, Idaho Natl Lab, Lockheed Martin Energy Syst Inc, A E Staley Mfg Co, Archer Daniels Midland Co, Bio-Tech Resources L P, Chronopol Inc, ConAgra Grain Processing Co, Enzyme Bio-Syst Ltd, DuPont Co, Grain Processing Corp, Raphael Katzen Associates Int Inc, Weyerhaeuser Co, Amer Chem Soc, Div Biochem Technol DE hexavalent chromium; bacterial reduction; bioprocess; chromate; bioreduction AB Hexavalent chromium, Cr(6+), is a common and toxic pollutant in soils and waters. Reduction of the mobile Cr(6+) to the less mobile and less toxic trivalent chromium, Cr(3(+)), can be achieved with conventional chemical reduction technologies. Alternatively, Cr(6(+)) can be biochemically reduced to Cr(3(+)) by anaerobic microbial consortia which appear to use Cr(6(+)) as a terminal electron acceptor. A bioprocess for Cr(6(+)) reduction has been demonstrated using a packed-bed bioreactor containing ceramic packing, and then compared to a similar bioreactor containing DuPont Bio-Sep beads. An increase in volumetric productivity (from 4 mg Cr(6(+))/L/h to 260 mg Cr(6(+))/L/h, probably due to an increase in biomass density, was obtained using Bio-Sep beads. The beads contain internal macropores which were shown by scanning electron microscopy to house dense concentrations of bacteria. Comparisons to conventional Cr(6(+)) treatment technologies indicate that a bioprocess has several economic and operational advantages. C1 DUPONT CO INC,WILMINGTON,DE. RP Turick, CE (reprint author), IDAHO NATL ENGN LAB,IDAHO FALLS,ID 83415, USA. NR 7 TC 17 Z9 17 U1 1 U2 1 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 SPR PY 1997 VL 63-5 BP 871 EP 877 DI 10.1007/BF02920483 PG 7 WC Biochemistry & Molecular Biology; Biotechnology & Applied Microbiology SC Biochemistry & Molecular Biology; Biotechnology & Applied Microbiology GA XB483 UT WOS:A1997XB48300078 PM 18576140 ER PT J AU Davison, BH Finkelstein, M Wyman, CE AF Davison, BH Finkelstein, M Wyman, CE TI Biotechnology for Fuels and Chemicals - Proceedings of the Eighteenth Symposium on Biotechnology for Fuels and Chemicals held May 5-9, 1996, at Gatlinburg, Tennessee - Introduction SO APPLIED BIOCHEMISTRY AND BIOTECHNOLOGY LA English DT Editorial Material RP Davison, BH (reprint author), OAK RIDGE NATL LAB,OAK RIDGE,TN, USA. RI Davison, Brian/D-7617-2013 OI Davison, Brian/0000-0002-7408-3609 NR 0 TC 0 Z9 0 U1 0 U2 0 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 SPR PY 1997 VL 63-5 BP R3 EP R6 PG 4 WC Biochemistry & Molecular Biology; Biotechnology & Applied Microbiology SC Biochemistry & Molecular Biology; Biotechnology & Applied Microbiology GA XB483 UT WOS:A1997XB48300001 ER PT J AU Meyers, S Sathaye, J Goldberg, B Wu, ZX Bordeaux, C AF Meyers, S Sathaye, J Goldberg, B Wu, ZX Bordeaux, C TI Greenhouse gas mitigation technologies and measures in developing and transition countries - Editors' introduction and acknowledgments SO APPLIED ENERGY LA English DT Editorial Material C1 TSING HUA UNIV,INST NUCL ENERGY TECHNOL,BEIJING 100084,PEOPLES R CHINA. US COUNTRY STUDIES PROGRAM,WASHINGTON,DC. RP Meyers, S (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,BERKELEY,CA 94720, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 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 PD MAR-APR PY 1997 VL 56 IS 3-4 BP 201 EP 201 DI 10.1016/S0306-2619(97)00005-6 PG 1 WC Energy & Fuels; Engineering, Chemical SC Energy & Fuels; Engineering GA XR663 UT WOS:A1997XR66300003 ER PT J AU Meyers, S Sathaye, J Goldberg, B Renne, D Kaupp, A Mendis, M Ernst, J Kokorin, A Kerr, T AF Meyers, S Sathaye, J Goldberg, B Renne, D Kaupp, A Mendis, M Ernst, J Kokorin, A Kerr, T TI International Workshop on Greenhouse Gas Mitigation Technologies and Measures: Summary SO APPLIED ENERGY LA English DT Editorial Material C1 NATL RENEWABLE ENERGY LAB,GOLDEN,CO. ENERGETIA INT,SUVA,FIJI. ALTERNAT ENERGY DEV INC,SILVER SPRING,MD. INST INST ENERGY CONSERVAT,BANGKOK,THAILAND. INST GLOBAL CLIMATE & ECOL,MOSCOW,RUSSIA. US EPA,WASHINGTON,DC 20460. RP Meyers, S (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,BERKELEY,CA 94720, USA. NR 0 TC 4 Z9 4 U1 0 U2 0 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 PD MAR-APR PY 1997 VL 56 IS 3-4 BP 203 EP 223 DI 10.1016/S0306-2619(97)00006-8 PG 21 WC Energy & Fuels; Engineering, Chemical SC Energy & Fuels; Engineering GA XR663 UT WOS:A1997XR66300004 ER PT J AU Sathaye, JA Dixon, RK Rosenzweig, C AF Sathaye, JA Dixon, RK Rosenzweig, C TI Climate change country studies SO APPLIED ENERGY LA English DT Article; Proceedings Paper CT International Workshop on Greenhouse Gas Mitigation Technologies and Measures CY NOV 12-15, 1996 CL BEIJING, PEOPLES R CHINA SP US Country Studies Program, Environm Canada, German Fed Minist Econ Cooperat & dev, Netherlands Minist Foreign Affairs, Peoples Republic China, State Sci & Technol Commiss ID EMISSIONS; ABATEMENT AB Over the past three years, country studies have improved country-specific, and hence global, estimates of: (i) greenhouse gas (GHG) emissions and sequestration, and (ii) costs and benefits of mitigation options, and (iii) the vulnerability of natural habitats and human systems. The technical and financial support provided by the US and other country-study programs has enhanced the contribution of experts from developing and transition countries to their global scientific assessment. This paper presents a brief overview of work conducted in the context of the US Country Studies Program in the development of national GHG inventories, assessment of GHG mitigation options, and assessment of vulnerability to climate change and options for adaptation. Published by Elsevier Science Ltd. C1 US COUNTRY STUDIES PROGRAM,WASHINGTON,DC. COLUMBIA UNIV,NASA,GODDARD INST SPACE STUDIES,NEW YORK,NY. RP Sathaye, JA (reprint author), LAWRENCE BERKELEY LAB,BERKELEY,CA 94720, USA. NR 33 TC 8 Z9 8 U1 0 U2 1 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 PD MAR-APR PY 1997 VL 56 IS 3-4 BP 225 EP 235 DI 10.1016/S0306-2619(97)0007X-4 PG 11 WC Energy & Fuels; Engineering, Chemical SC Energy & Fuels; Engineering GA XR663 UT WOS:A1997XR66300005 ER PT J AU Li, JF Wan, YH Ohi, JM AF Li, JF Wan, YH Ohi, JM TI Renewable energy development in China: Resource assessment, technology status, and greenhouse gas mitigation potential SO APPLIED ENERGY LA English DT Article; Proceedings Paper CT International Workshop on Greenhouse Gas Mitigation Technologies and Measures CY NOV 12-15, 1996 CL BEIJING, PEOPLES R CHINA SP US Country Studies Program, Environm Canada, German Fed Minist Econ Cooperat & dev, Netherlands Minist Foreign Affairs, Peoples Republic China, State Sci & Technol Commiss AB China has become the third largest energy user in the world, and its coal-dominated energy structure implies high CO2 emissions. The amount of CO2 emissions from China may surpass that of the United States within 20-30 years, making China the world's largest source of greenhouse gases by 2020. Currently, renewable energy resources (except for hydropower) account for only a fraction of China's total energy consumption. However, China has abundant solar energy resources. More than two thirds of China receives an annual total insolation that exceeds 5.9 GJ/m(2) (1,639 kWh/m(2)) with more than 2,200 hours of sunshine a year. Wind energy potential in China is about 3,200 GW, of which 253 GW is deemed technically exploitable. China has a wide range of biomass resources that can be used for energy supply and high temperature geothermal resources suitable for power generation located mainly in Tibet and Yunnan provinces. Renewable energy technologies have been actively deployed in China. Although PV power stations have not being connected to the national grid, total installed capacity was 3 MW in 1994. Solar water heaters are by far the largest solar thermal application in China with a total installed capacity of 3.3 million m(2) in 1994. By the end of 1995, total installed capacity of grid-connected wind power plants had reached 36 MW. Also, over 140,000 small wind generators ranging in size from 50 W to 5 kW have been deployed with a total installed capacity of 17 MW. China is a world leader in the development and application of anaerobic technologies for the production of fuel gas and waste treatment and has by far the largest biomass gasification R&D capacity in the (sic). Although renewable energy is projected to play a small role in future electricity generation, it is expected to be much more significant in the total energy sector. Under one scenario, renewable energy other than hydro provides up to 4% of the total energy supply and 88 million tons of carbon emission reduction by 2020. The estimated growth in greenhouse gas emissions, as well as serious local and regional environmental pollution problems caused by combustion of fossil fuels, provide strong arguments for the development of renewable energy resources. Published by Elsevier Science Ltd. C1 NATL RENEWABLE ENERGY LAB,GOLDEN,CO. RP Li, JF (reprint author), ENERGY RES INST,STATE PLANNING COMMISS,CTR RENEWABLE ENERGY DEV,BEIJING,PEOPLES R CHINA. NR 5 TC 19 Z9 23 U1 2 U2 25 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 PD MAR-APR PY 1997 VL 56 IS 3-4 BP 381 EP 394 PG 14 WC Energy & Fuels; Engineering, Chemical SC Energy & Fuels; Engineering GA XR663 UT WOS:A1997XR66300016 ER PT J AU Branham, KE Mays, JW Gray, GM Sanner, RD Overturf, GE Cook, R AF Branham, KE Mays, JW Gray, GM Sanner, RD Overturf, GE Cook, R TI Reactions of titanocene derivatives with molecular carboxylic acids and copolymers bearing carboxylic acid groups SO APPLIED ORGANOMETALLIC CHEMISTRY LA English DT Article DE laser fusion; titanium; metal-containing polymer; titanocene; carboxylic acid ID DECOMPOSITION; DINITROGEN; CATALYSTS AB Linear, soluble copolymers containing titanium are of interest for use in targets for inertfal-confinement fusion (ICF) experiments because the titanium is a useful spectroscopic probe for studying the nuclear fusion process, We have studied the reactions of dichloro-titanocene and diphenyltitanocene with carboxylic acids to determine if these can be used to prepare such polymers, Model reactions of dichlorotitanocene with p-toluic acid show that both mono- and di-carboxylates are formed, We have prepared a soluble titanium-containing copolymer via the reaction of poly(styrene-co-methacrylic acid) with an excess of dichlorotitanocene but attempts to remove the excess molecular titanocene from the copolymer result in crosslinking of the copolymer, Model reactions of benzoic and pivalic acids with diphenyltitanocene demonstrate that monosubstituted carboxylato(phenyl)titanocenes are formed but that these products are stable only at low temperatures and decompose readily at ambient temperature, Proton NMR studies of the reaction of diphenyltitanocene and benzoic acid at - 20 degrees C indicate that this reaction is second order, suggesting that the reaction does not proceed through a benzyne intermediate. (C) 1997 by John Wiley & Sons, Ltd. C1 UNIV ALABAMA, DEPT CHEM, BIRMINGHAM, AL 35294 USA. LAWRENCE LIVERMORE NATL LAB, LIVERMORE, CA 94550 USA. NR 25 TC 7 Z9 7 U1 0 U2 1 PU WILEY-BLACKWELL PI MALDEN PA COMMERCE PLACE, 350 MAIN ST, MALDEN 02148, MA USA SN 0268-2605 J9 APPL ORGANOMET CHEM JI Appl. Organomet. Chem. PD MAR PY 1997 VL 11 IS 3 BP 213 EP 221 PG 9 WC Chemistry, Applied; Chemistry, Inorganic & Nuclear SC Chemistry GA WM270 UT WOS:A1997WM27000003 ER PT J AU Khazeni, K Hone, J Chopra, NG Zettl, A Nguyen, J Jeanloz, R AF Khazeni, K Hone, J Chopra, NG Zettl, A Nguyen, J Jeanloz, R TI Transport and structural properties of polymerized AC(60) (A=K, Rb) under zero and high pressure conditions SO APPLIED PHYSICS A-MATERIALS SCIENCE & PROCESSING LA English DT Article ID METAL-INSULATOR-TRANSITION; ELECTRONIC-PROPERTIES; ORTHORHOMBIC RBC60; PHASE-TRANSITION; SOLID-STATE; NMR; FULLERIDES; RB1C60; KC60 AB Polymerized forms of alkali-doped C-60 display transport properties vastly different from their unpolymerized counterparts. We here describe structural (X-ray diffraction and transmission electron microscopy) and de resistivity measurements of polymerized AC(60) (A = K, Rb) at zero and high pressures. The structural and electronic properties are rich, and evidence is found for unusual phase transitions in both materials. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV MAT SCI,BERKELEY,CA 94720. UNIV CALIF BERKELEY,DEPT GEOL & GEOPHYS,BERKELEY,CA 94720. RP Khazeni, K (reprint author), UNIV CALIF BERKELEY,DEPT PHYS,BERKELEY,CA 94720, USA. RI Hone, James/E-1879-2011; Zettl, Alex/O-4925-2016 OI Hone, James/0000-0002-8084-3301; Zettl, Alex/0000-0001-6330-136X NR 37 TC 9 Z9 9 U1 0 U2 2 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 SN 0947-8396 J9 APPL PHYS A-MATER JI Appl. Phys. A-Mater. Sci. Process. PD MAR PY 1997 VL 64 IS 3 BP 263 EP 269 DI 10.1007/s003390050477 PG 7 WC Materials Science, Multidisciplinary; Physics, Applied SC Materials Science; Physics GA WN715 UT WOS:A1997WN71500009 ER PT J AU Zamora, PO Marek, MJ Knapp, FF AF Zamora, PO Marek, MJ Knapp, FF TI Preparation of Re-188-RC-160 somatostatin analog: A peptide for local/regional radiotherapy SO APPLIED RADIATION AND ISOTOPES LA English DT Article AB Conditions are described for the preparation of Re-188-RC-160, a radiolabeled synthetic peptide derived from an analogue of somatostatin, using a lyophilized labeling kit containing RC-160 (200 mu g) and stannous tartrate to which is added carrier-free Re-188 (beta, E(max), 2.12 MeV; gamma, 155 keV, 10%; T-1/2 = 16.7 h). The kits have been radiolabeled with > 2960 MBq (80 mCi) with a high labeling efficiency and no need for subsequent purification. Radiolabeling results in one major peak when analyzed by reverse-phase (RP) HPLC. Presumptive radiolysis was detected at 2.5 h post-labeling; however, a convenient method is described for stabilizing the kits against radiolysis by the post-labeling addition of ascorbic acid. (C) 1997 Elsevier Science Ltd. C1 OAK RIDGE NATL LAB,HLTH SCI RES DIV,NUCL MED GRP,OAK RIDGE,TN. RP Zamora, PO (reprint author), RHOMED INC,4261 BALLOON PK RD NE,ALBUQUERQUE,NM 87109, USA. NR 8 TC 21 Z9 23 U1 1 U2 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0969-8043 J9 APPL RADIAT ISOTOPES JI Appl. Radiat. Isot. PD MAR PY 1997 VL 48 IS 3 BP 305 EP 309 DI 10.1016/S0969-8043(96)00226-6 PG 5 WC Chemistry, Inorganic & Nuclear; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Chemistry; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA WL882 UT WOS:A1997WL88200001 PM 9116651 ER PT J AU Haaland, DM Jones, HDT Thomas, EV AF Haaland, DM Jones, HDT Thomas, EV TI Multivariate classification of the infrared spectra of cell and tissue samples SO APPLIED SPECTROSCOPY LA English DT Article DE multivariate IR classification; PLS, PCR; discriminant analysis; classification of cells and tissue; FT-IR; cancer detection ID FT-IR SPECTRA; COLON TISSUES; SPECTROSCOPY; CLL AB Infrared microspectroscopy of biopsied canine lymph cells and tissue was performed to investigate the possibility of using IR spectra coupled with multivariate classification methods to classify the samples as normal, hyperplastic, or neoplastic (malignant). IR spectra were obtained in transmission mode through BaF2 windows and in reflection mode from samples prepared on gold-coated microscope slides. Cytology and histopathology samples were prepared by a variety of methods to identify the optimal methods of sample preparation. Cytospinning procedures that yielded a monolayer of cells on the BaF2 windows produced a limited set of IR transtensional spectra. These transmission spectra were concerted to absorbance and formed the basis for a classification rule that yielded 100% correct classification in a cross-validated context. Classifications of normal, hyperplastic, and neoplastic cell sample spectra were achieved by using both partial least-squares (PLS) and principal component regression (PCR) classification methods. Linear discriminant analysis applied to principal components obtained from the spectral data yielded a small number of misclassifications. PLS weight loading vectors yield valuable qualitative insight into the molecular changes that are responsible for the success of the infrared classification. These successful classification results show promise for assisting pathologists in the diagnosis of cell types and offer future potential for in vivo LR detection of some types of cancer. RP Haaland, DM (reprint author), SANDIA NATL LABS,POB 5800,ALBUQUERQUE,NM 87185, USA. NR 28 TC 62 Z9 63 U1 1 U2 4 PU SOC APPLIED SPECTROSCOPY PI FREDERICK PA 201B BROADWAY ST, FREDERICK, MD 21701 SN 0003-7028 J9 APPL SPECTROSC JI Appl. Spectrosc. PD MAR PY 1997 VL 51 IS 3 BP 340 EP 345 DI 10.1366/0003702971940468 PG 6 WC Instruments & Instrumentation; Spectroscopy SC Instruments & Instrumentation; Spectroscopy GA WT586 UT WOS:A1997WT58600009 ER PT J AU Enderlein, J Keller, RA AF Enderlein, J Keller, RA TI Comparison of one-focus and two-foci setup in single-molecule detection experiments SO APPLIED SPECTROSCOPY LA English DT Article DE single-molecule detection; flow cytometry; laser-induced fluorescence ID LASER-INDUCED FLUORESCENCE; FLOW-CYTOMETRY; ELECTROPHORESIS; BIOTECHNOLOGY; FRAGMENTS RP Enderlein, J (reprint author), LOS ALAMOS NATL LAB,CHEM SCI & TECHNOL DIV,MS M888,LOS ALAMOS,NM 87545, USA. NR 21 TC 2 Z9 2 U1 1 U2 1 PU SOC APPLIED SPECTROSCOPY PI FREDERICK PA 201B BROADWAY ST, FREDERICK, MD 21701 SN 0003-7028 J9 APPL SPECTROSC JI Appl. Spectrosc. PD MAR PY 1997 VL 51 IS 3 BP 443 EP 446 DI 10.1366/0003702971940350 PG 4 WC Instruments & Instrumentation; Spectroscopy SC Instruments & Instrumentation; Spectroscopy GA WT586 UT WOS:A1997WT58600026 ER PT J AU Bono, G Caputo, F Cassisi, S Castellani, V Marconi, M Stellingwerf, RF AF Bono, G Caputo, F Cassisi, S Castellani, V Marconi, M Stellingwerf, RF TI Second overtone pulsators among delta Scuti stars SO ASTROPHYSICAL JOURNAL LA English DT Article DE stars, interiors; stars, oscillations; stars, variables, other (delta Scuti) ID RR LYRAE STARS; THEORETICAL EVOLUTION SEQUENCES; VARIABLE-STARS; MODAL STABILITY; ENVELOPES; OPACITIES; HERCULIS; MODELS AB We investigate the modal stability of stellar models at masses and luminosity levels corresponding to post-main-sequence luminous delta Scuti pulsators. The envelope models have been computed at fixed mass value (M/M. = 2.0), luminosity level [log (L/L.) = 1.7], and chemical composition (Y = 0.28, Z = 0.02). According to a nonlinear approach to radial oscillations, the present investigation for the first time predicts the occurrence of stable second overtone pulsators. More generally, we found that when moving inside the instability strip from lower to higher effective temperatures, the models show a stable limit cycle in three different pulsation modes: fundamental and first and second overtones. The shapes of both light and velocity curves are presented and discussed, providing a useful tool for the identification of second overtone pulsators among the known groups of radially pulsating stars. Comparison with observations shows that our nonlinear, nonlocal, and time-dependent convective models provide light curves in agreement with observed values, suggesting that second overtone pulsators have already been observed, though misclassified as fundamental pulsators. In a limited region of the instability strip we also found some models presenting mixed-mode features, i.e., radial pulsators that show a stable limit cycle in more than one pulsational mode. The period ratios of mixed-mode pulsators obtained by perturbing the first and the second overtone radial eigenfunctions are in agreement with observed values. This result is a crucial point for understanding the pulsation properties of delta Scuti stars, since it provides sound evidence that these variables during their evolution off the main sequence are pure or mixed-mode radial pulsators. Finally, the physical structure and the dynamical properties of second overtone pulsators are discussed in detail. The role played by the nodal lines in the destabilization of second overtone pulsators is also pointed out. C1 OSSERV ASTRON CAPODIMONTE,I-80131 NAPLES,ITALY. OSSERVATORIO ASTRON TERAMO,I-64100 TERAMO,ITALY. UNIV PISA,DIPARTIMENTO FIS,I-56100 PISA,ITALY. LOS ALAMOS NATL LAB,X1 DIV,LOS ALAMOS,NM 87545. RP Bono, G (reprint author), OSSERV ASTRON TRIESTE,VIA GB TIEPOLO 11,I-34131 TRIESTE,ITALY. NR 47 TC 19 Z9 20 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 S WOODLAWN AVE, CHICAGO, IL 60637 SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD MAR 1 PY 1997 VL 477 IS 1 BP 346 EP 355 DI 10.1086/303710 PN 1 PG 10 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA WK037 UT WOS:A1997WK03700030 ER PT J AU Tavani, M Arons, J AF Tavani, M Arons, J TI Theory of high-energy emission from the pulsar/Be star system PSR 1259-63 .1. Radiation mechanisms and interaction geometry SO ASTROPHYSICAL JOURNAL LA English DT Article DE binaries, close; pulsars, individual (PSR B1259-63); radiation mechanisms, nonthermal; shock waves; stars, emission-line, Be; X-rays, stars ID X-RAY-EMISSION; NEUTRON-STARS; BINARY-SYSTEM; RADIO PULSAR; MILLISECOND PULSARS; CRAB PULSAR; NEBULA; PSR-1259-63; DISCOVERY; B1259-63 AB We study the physical processes in the system containing the 47 ms radio pulsar PSR B1259-63 orbiting around a Be star in a highly eccentric orbit. This system is the only known binary where a radio pulsar is observed to interact with gaseous material from a Be star. A rapidly rotating radio pulsar such as PSR B1259-63 is expected to produce a wind of electromagnetic emission and relativistic particles, and this binary is an ideal astrophysical laboratory to study the mass outflow/pulsar interaction in a highly time-variable environment. Motivated by the results of a recent multiwavelength campaign during the 1994 January periastron passage of PSR B1259-63, we discuss several issues regarding the mechanism of high-energy emission. Unpulsed power-law emission from the PSR B1259-63 system was detected near periastron in the energy range 1-200 keV. The observed X-ray/soft gamma-ray emission is characterized by moderate luminosity, small and constant column density, lack of detectable pulsations, and peculiar spectral and intensity variability. In principle, high-energy (X-ray and gamma-ray) emission from the system can be produced by different mechanisms including (1) mass accretion onto the surface of the neutron star, (2) ''propeller''-like magnetospheric interaction at a small pulsar distance, and (3) shock-powered emission in a pulsar wind termination shock at a large distance from the pulsar. We carry out a series of calculations aimed at modeling the high-energy data of the PSR B1259-63 system throughout its orbit and especially near periastron. We find that the observed high-energy emission from the PSR B1259-63 system is not compatible with accretion or propeller-powered emission. This conclusion is supported by a model based on standard properties of Be stars and for plausible assumptions about the pulsar/outflow interaction geometry. We find that shock-powered high-energy emission produced by the pulsar/outflow interaction is consistent with all the characteristics of the high-energy emission of the PSR B1259-63 system. This opens the possibility of obtaining for the first time constraints on the physical properties of the PSR B1259-63 pulsar wind and its interaction properties in a strongly time-variable nebular environment. By studying the time evolution of the pulsar cavity, we can constrain the magnitude and geometry of the mass outflow as the PSR B1259-63 orbits around its Be star companion. The pulsar/outflow interaction is most likely mediated by a collisionless shock at the internal boundary of the pulsar cavity. The system shows all the characteristics of a binary plerion being diffuse and compact near apastron and periastron, respectively. The PSR B1259-63 system is subject to different radiative regimes depending on whether synchrotron or inverse-Compton (IC) cooling dominates the radiation of electron/positron pairs (e(+/-) pairs) advected away from the inner boundary of the pulsar cavity. The highly nonthermal nature of the observed X-ray/soft gamma-ray emission from the PSR B1259-63 system near periastron establishes the existence of an efficient particle acceleration mechanism within a timescale shown to be less than similar to 10(2)-10(3) a. A synchrotron/IC model of emission of e(+/-) pairs accelerated at the inner shock front of the pulsar cavity and adiabatically expanding in the MHD flow provides an excellent explanation of the observed time-variable X-ray flux and spectrum from the PSR B1259-63 system. We find that the best model for the PSR B1259-63 system is consistent with the pulsar orbital plane being misaligned with the plane of a thick equatorial Be star outflow. The angular width of the equatorially enhanced Be star outflow is constrained to be similar to 50 degrees at the pulsar distance, and the misalignment angle is greater than or similar to 25 degrees. We calculate the intensity and spectrum of the high-energy emission for the whole PSR B1259-63 orbit and predict the characteristics of the emission near the apastron region based on the periastron results. The mass-loss rate is deduced to be approximately constant in time during a similar to 2 yr period. Our results for the Be star outflow of the PSR B1259-63 system are consistent with models of the radio eclipses near periastron. The consequences of our analysis have general validity. Our study of the PSR B1259-63 system shows that X-ray emission can be caused by a mechanism alternative to accretion in a system containing an energetic pulsar interacting with nebular material. This fact can have far-reaching consequences for the interpretation of galactic astrophysical systems showing nonthermal X-ray and gamma-ray emission. We show that a binary system such as PSR B1259-63 offers a novel way to study the acceleration process of relativistic plasmas subject to strongly time variable radiative environments. C1 UNIV CALIF BERKELEY, DEPT ASTRON, BERKELEY, CA 94720 USA. UNIV CALIF BERKELEY, DEPT PHYS, BERKELEY, CA 94720 USA. LAWRENCE LIVERMORE NATL LAB, INST GEOPHYS & PLANETARY PHYS, LIVERMORE, CA 94550 USA. RP Tavani, M (reprint author), COLUMBIA UNIV, ASTROPHYS LAB, NEW YORK, NY 10027 USA. OI Tavani, Marco/0000-0003-2893-1459 NR 59 TC 164 Z9 164 U1 1 U2 3 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD MAR 1 PY 1997 VL 477 IS 1 BP 439 EP 464 DI 10.1086/303676 PN 1 PG 26 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA WK037 UT WOS:A1997WK03700039 ER PT J AU Eikenberry, SS Fazio, GG Ransom, SM Middleditch, J Kristian, J Pennypacker, CR AF Eikenberry, SS Fazio, GG Ransom, SM Middleditch, J Kristian, J Pennypacker, CR TI High time resolution infrared observations of the Crab Nebula pulsar and the pulsar emission mechanism SO ASTROPHYSICAL JOURNAL LA English DT Article DE instrumentation, detectors (solid state photomultiplier); pulsars, individual (PSR 0531+21); radiation mechanism, nonthermal; stars, neutron AB We present new, high signal-to-noise near-infrared observations of the Crab Nebula pulsar using the Solid State Photomultiplier instrument on the Multiple Mirror Telescope. Our observations cover the J (1.25 mu m), H (1.65 mu m), and K (2.2 mu m) infrared wavebands and have 20 mu s time resolution. Together with visible and UV observations made by the Hubble Space Telescope High-Speed Photometer, we have high time resolution observations covering over a decade in wavelength. We present the pulse profiles over this wavelength range, and we analyze the pulse shape as a function of wavelength, including the peak-to-peak phase separation, the peak full width half-maxima (FWHM), and the peak half-width half-maxima (HWHM). We also create both phase-averaged and phase-resolved color spectra of the pulsar emission. We find that the peak-to-peak phase separation shows a significant trend for an increase with wavelength, in rough agreement with models of the pulsar emission mechanism. The FWHM for peaks 1 and 2 also show a trend for increase with wavelength, again in qualitative agreement with the models. However, the HWHM for peaks 1 and 2 show significant differences in their wavelength dependences from the leading to trailing edges. This behavior is not predicted by current pulsar emission models, and the different wavelength dependences of the component HWHM values call into question the usefulness of FWHM measurements. Our spectral analyses show that the IR-UV dereddened phase-averaged color spectrum is essentially flat over more than a decade in frequency. This is in clear contrast to the X-ray and gamma-ray regimes, where the spectrum is falling steeply. The color spectra of peaks 1 and 2 are also essentially flat, but the ratio of the two shows statistically significant variations from a constant value. Finally, the color spectra of peaks 1 and 2 show significant differences from the leading to trailing edges. As with the HWHM, this behavior is not predicted by current pulsar emission models. C1 LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545. CARNEGIE INST WASHINGTON OBSERV,PASADENA,CA 91101. UNIV CALIF BERKELEY,SPACE SCI LAB,BERKELEY,CA 94720. KITT PEAK NATL OBSERV,TUCSON,AZ. RP Eikenberry, SS (reprint author), HARVARD SMITHSONIAN CTR ASTROPHYS,CAMBRIDGE,MA 02138, USA. NR 17 TC 28 Z9 28 U1 0 U2 4 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 S WOODLAWN AVE, CHICAGO, IL 60637 SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD MAR 1 PY 1997 VL 477 IS 1 BP 465 EP 474 DI 10.1086/303701 PN 1 PG 10 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA WK037 UT WOS:A1997WK03700040 ER PT J AU Carilli, CL Rottgering, HJA vanOjik, R Miley, GK vanBreugel, WJM AF Carilli, CL Rottgering, HJA vanOjik, R Miley, GK vanBreugel, WJM TI Radio continuum imaging of high-redshift radio galaxies SO ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES LA English DT Article DE galaxies, structure; polarization; radio continuum, galaxies ID FARADAY-ROTATION; MAGNETIC-FIELDS; LUMINOSITY FUNCTION; MOLONGLO CATALOG; COOLING FLOWS; CYGNUS-A; QUASARS; EVOLUTION; PROTOGALAXIES; DISCOVERY AB We present sensitive radio continuum observations at high resolution of 37 radio galaxies at z > 2. The observations were made with the Very Large Array (VLA) at 4.7 and 8.2 GHz, with typical resolutions of 0.45 '' and 0.25 '', respectively. Images of total and polarized intensity, and spectral index, are presented. Values for total and polarized intensity, and values of rotation measures, are tabulated for the hot spots in each source. The positions of the radio nuclei are tabulated along with a variety of other source parameters. Analysis of the polarization data reveals large rotation measures (RMs) towards seven sources. We argue that the RMs are due to magnetized, ionized gas local to the radio sources. The magnitude of the RMs are in excess of 1000 rad m(-2) (rest frame) for these sources. Drawing an analogy to a class of lower redshift radio galaxies with extreme RMs, we speculate that these sources may be at the centers of dense X-ray emitting cluster atmospheres. C1 LEIDEN OBSERV,NL-2300 RA LEIDEN,NETHERLANDS. LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550. RP Carilli, CL (reprint author), NATL RADIO ASTRON OBSERV,POB O,SOCORRO,NM 87801, USA. NR 72 TC 136 Z9 136 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 S WOODLAWN AVE, CHICAGO, IL 60637 SN 0067-0049 J9 ASTROPHYS J SUPPL S JI Astrophys. J. Suppl. Ser. PD MAR PY 1997 VL 109 IS 1 BP 1 EP 44 DI 10.1086/312973 PG 44 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA WN498 UT WOS:A1997WN49800001 ER PT J AU Munn, JA Koo, DC Kron, RG Majewski, SR Bershady, MA Smetanka, JJ AF Munn, JA Koo, DC Kron, RG Majewski, SR Bershady, MA Smetanka, JJ TI The kitt peak galaxy redshift survey with multicolor photometry: Basic data SO ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES LA English DT Article DE astrometry; cosmology, observations; galaxies, distances and redshifts; galaxies, photometry; surveys ID COMPLETE SAMPLE; FAINT GALAXIES; FIELD GALAXIES; SPECTROSCOPY; COLORS AB Redshifts, four-band photometry (UB(J)R(F)I(N)), and astrometry are presented for faint galaxies in four widely separated fields. We provide the necessary information to enable well-defined, statistically complete subsamples of faint galaxies to be constructed from the master catalog. The redshift survey is 86% and 71% complete to R(F) less than or equal to 18.5 and R(F) less than or equal to 19, respectively, yielding 328 galaxies with reliable redshifts to R(F) less than or equal to 19, with a median redshift of 0.142. Adding the galaxies from the fainter statistical sample yields a total of 583 reliable redshifts with a median redshift of 0.202. An additional 156 redshifts in the same fields, but not part of the samples defined here, are also given. Of the 739 galaxy redshifts presented, 212 are for galaxies with R(F) > 20. C1 UNIV CALIF SANTA CRUZ,LICK OBSERV,BOARD STUDIES ASTRON & ASTROPHYS,SANTA CRUZ,CA 95064. FERMILAB NATL ACCELERATOR LAB,BATAVIA,IL 60510. UNIV VIRGINIA,DEPT ASTRON,CHARLOTTESVILLE,VA 22903. CARNEGIE INST WASHINGTON OBSERV,PASADENA,CA 91101. PENN STATE UNIV,DEPT ASTRON & ASTROPHYS,UNIVERSITY PK,PA 16802. UNIV CHICAGO,DEPT ASTRON & ASTROPHYS,CHICAGO,IL 60637. RP Munn, JA (reprint author), UNIV CHICAGO,YERKES OBSERV,POB 258,WILLIAMS BAY,WI 53191, USA. NR 34 TC 28 Z9 28 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 S WOODLAWN AVE, CHICAGO, IL 60637 SN 0067-0049 J9 ASTROPHYS J SUPPL S JI Astrophys. J. Suppl. Ser. PD MAR PY 1997 VL 109 IS 1 BP 45 EP 77 DI 10.1086/312971 PG 33 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA WN498 UT WOS:A1997WN49800002 ER PT J AU Drescher, AC Park, DY Yost, MG Gadgil, AJ Levine, SP Nazaroff, WW AF Drescher, AC Park, DY Yost, MG Gadgil, AJ Levine, SP Nazaroff, WW TI Stationary and time-dependent indoor tracer-gas concentration profiles measured by OP-FTIR remote sensing and SBFM-computed tomography SO ATMOSPHERIC ENVIRONMENT LA English DT Article DE remote sensing; computed tomography; indoor air quality; gas monitoring ID CHEMICAL CONCENTRATIONS; RECONSTRUCTION; AIR AB Measurement of gas concentrations in indoor air using optical remote sensing (ORS) and computed tomography (CT) has been suggested but not thoroughly investigated. We present experiments in which one time-varying and 11 different steady-state tracer-gas concentration profiles were generated in a ventilated chamber and sampled in a horizontal plane by an open-path Fourier transform infrared (OP-FTIR) spectrometer for subsequent CT inversion. CT reconstructions were performed using the recently developed smooth basis function minimization (SBFM) technique. The CT reconstructions were compared with simultaneously gathered point-sample concentration measurements. Agreement between the two sampling methods was qualitatively very good, with concentration profiles generated by both methods showing the same features of peak location and shape. Quantitative agreement was generally good to within 50%. We discuss the sources of discrepancy and suggest directions for future research, especially with regard to monitoring time-dependent processes. With further refinements in the SBFM algorithm and improvements in optical remote sensing hardware, this technique promises to yield rapid and accurate measurements of the spatial distribution of gases in indoor environments. Copyright (C) 1996 Elsevier Science Ltd. C1 UNIV CALIF BERKELEY,DEPT CIVIL & ENVIRONM ENGN,BERKELEY,CA 94720. LAWRENCE BERKELEY LAB,INDOOR ENVIRONM PROGRAM,DIV ENERGY & ENVIRONM,BERKELEY,CA 94720. UNIV MICHIGAN,DEPT ENVIRONM & IND HLTH,ANN ARBOR,MI 48109. UNIV WASHINGTON,DEPT ENVIRONM HLTH,SEATTLE,WA 98195. RI Nazaroff, William/C-4106-2008; OI Nazaroff, William/0000-0001-5645-3357; Gadgil, Ashok/0000-0002-0357-9455 NR 17 TC 45 Z9 49 U1 1 U2 4 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 1352-2310 J9 ATMOS ENVIRON JI Atmos. Environ. PD MAR PY 1997 VL 31 IS 5 BP 727 EP 740 DI 10.1016/S1352-2310(96)00221-X PG 14 WC Environmental Sciences; Meteorology & Atmospheric Sciences SC Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences GA VZ001 UT WOS:A1997VZ00100007 ER PT J AU Hanson, PJ Tabberer, TA Lindberg, SE AF Hanson, PJ Tabberer, TA Lindberg, SE TI Emissions of mercury vapor from tree bark SO ATMOSPHERIC ENVIRONMENT LA English DT Article DE biogenic emissions; terrestrial; vegetation ID FOREST; EXCHANGE; SOILS AB Measurements of the rate of elemental Hg vapor (Hg degrees) emissions from the bark of red maple (Acer rubrum L.), yellow-poplar (Liriodendron tulipifera L.), chestnut oak (Quercus prinus L.) and white oak (Quercus alba L.) were conducted in a controlled laboratory chamber with a mean air Hg degrees concentration of 1.6 ng m(-3). Measured Hg degrees emissions for the four bark species studied ranged from a maximum of 10.8 ng m(-2) h(-1) for white oak to a minimum of 1.2 ng m(-2) h(-1) for red maple. Chestnut oak, yellow-poplar, and red maple bark all had similar Hg degrees emission rates with a mean of 1.9 ng m(-2) h(-1), but the mean emission rates from white oak were up to five times greater. This discrepancy was correlated with higher rates of evaporation from the white oak bark samples. When compared to published values of Hg degrees emissions from foliage and soils, it was concluded that bark surfaces would contribute less than 10% of all Hg degrees emissions from a forest landscape. Copyright (C) 1996 Elsevier Science Ltd. RP Hanson, PJ (reprint author), OAK RIDGE NATL LAB,DIV ENVIRONM SCI,POB 2008,OAK RIDGE,TN 37831, USA. RI Hanson, Paul J./D-8069-2011 OI Hanson, Paul J./0000-0001-7293-3561 NR 19 TC 5 Z9 7 U1 4 U2 7 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 1352-2310 J9 ATMOS ENVIRON JI Atmos. Environ. PD MAR PY 1997 VL 31 IS 5 BP 777 EP 780 DI 10.1016/S1352-2310(96)00231-2 PG 4 WC Environmental Sciences; Meteorology & Atmospheric Sciences SC Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences GA VZ001 UT WOS:A1997VZ00100011 ER PT J AU Fast, JD Berkowitz, CM AF Fast, JD Berkowitz, CM TI Evaluation of back trajectories associated with ozone transport during the 1993 North Atlantic regional experiment SO ATMOSPHERIC ENVIRONMENT LA English DT Article DE trajectory; long-range transport; boundary layer processes; turbulence; diffusion; mesoscale model; Lagrangian model ID 4-DIMENSIONAL DATA-ASSIMILATION; TEMPORAL RESOLUTION; METEOROLOGICAL DATA; MODELING SYSTEM; BOUNDARY-LAYER; UNITED-STATES; CLOSURE-MODEL; WIND-FIELD; SENSITIVITY; DISPERSION AB Back trajectories traditionally have been used to identify possible sources of pollutants measured at a receptor location; however, they neglect turbulent diffusion processes that affect pollutant transport. After evaluating the performance of a coupled mesoscale and Lagrangian particle dispersion model with observations taken during the 1993 Northern Atlantic Regional Experiment (NARE), a series of forward and back trajectories are analyzed to determine the errors associated with the back trajectory calculations. The forward trajectories are based on the mean and turbulent wind components and their initial positions correspond to several urban areas in eastern North America. The back trajectories employ only the mean wind components and their initial positions correspond to the final positions of the forward trajectories within a sampling volume near Yarmouth, Nova Scotia. Large differences between the forward and back trajectory positions occurred since the back trajectories did not include the irreversible turbulent diffusion processes. The back trajectories had no mechanism to identify surface source regions, with the consequence that the back trajectories would either pass over the ''true'' source region, or miss it altogether as a result of locating the particle at an incorrect horizontal position. A horizontal displacement error of +/- 100-400 km and a vertical displacement error of +/- 0.2-1 km occurred after 2 days of transport. These errors leveled off between 2 and 3 days, but grew larger again after 3 days of transport. The model results suggest that the use of back trajectories by themselves may be an inappropriate approach for estimating the Source location of a plume emitted near the surface. Copyright (C) 1996 Elsevier Science Ltd RP PACIFIC NW NATL LAB, RICHLAND, WA 99352 USA. NR 42 TC 10 Z9 10 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 1352-2310 EI 1873-2844 J9 ATMOS ENVIRON JI Atmos. Environ. PD MAR PY 1997 VL 31 IS 6 BP 825 EP 837 DI 10.1016/S1352-2310(96)00256-7 PG 13 WC Environmental Sciences; Meteorology & Atmospheric Sciences SC Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences GA WB867 UT WOS:A1997WB86700005 ER PT J AU Chen, MH Reed, KJ McWilliams, DM Guo, DS Barlow, L Lee, M Walker, V AF Chen, MH Reed, KJ McWilliams, DM Guo, DS Barlow, L Lee, M Walker, V TI K-shell Auger and radiative transitions in the carbon isoelectronic sequence, 6<=Z<=54 SO ATOMIC DATA AND NUCLEAR DATA TABLES LA English DT Article ID DIELECTRONIC SATELLITE SPECTRA; LI-LIKE IONS; CONFIGURATIONS; RATES AB K-shell energies and transition rates for the Auger and radiative decays in carbon-like ions with 1s2s(m)2p(n) (m + n = 5) configurations have been calculated using the multiconfiguration Dirac-Fock method including Breit interaction and quantum electrodynamic corrections. Seventeen ions with atomic numbers 6 less than or equal to Z less than or equal to 54 were considered. Transition rates were evaluated in intermediate coupling with configuration interaction within the same complex. Line fluorescence yields were also computed. (C) 1997 Academic Press. C1 SOUTHERN UNIV,DEPT PHYS,BATON ROUGE,LA 70813. A&M COLL,BATON ROUGE,LA 70813. RP Chen, MH (reprint author), LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550, USA. NR 16 TC 22 Z9 22 U1 0 U2 1 PU ACADEMIC PRESS INC JNL-COMP SUBSCRIPTIONS PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 SN 0092-640X J9 ATOM DATA NUCL DATA JI Atom. Data Nucl. Data Tables PD MAR PY 1997 VL 65 IS 2 BP 289 EP 370 DI 10.1006/adnd.1997.0739 PG 82 WC Physics, Atomic, Molecular & Chemical; Physics, Nuclear SC Physics GA WT622 UT WOS:A1997WT62200003 ER PT J AU Harding, LB AF Harding, LB TI Potential energy surfaces for CH bond cleavage reactions SO BERICHTE DER BUNSEN-GESELLSCHAFT-PHYSICAL CHEMISTRY CHEMICAL PHYSICS LA English DT Article; Proceedings Paper CT Discussion Meeting of the Deutsche-Bunsen-Gesellschaft on Unimolecular Reactions CY OCT 21-24, 1996 CL TUTZING, GERMANY SP Deut Bunsen Gesell DE elementary reactions; quantum mechanics; radicals ID TRANSITION-STATE THEORY; CORRELATED MOLECULAR CALCULATIONS; GAUSSIAN-BASIS SETS; H + CH3; RATE CONSTANTS; FLASH-PHOTOLYSIS; REVERSIBLE CH4; METHANE; DISSOCIATION; RADICALS AB Ab initio, multi-reference, configuration interaction calculations are reported for the reactions, (4) CH4 <-> CH3+H (5) CH3F <-> CH2F+H (6) CH2F2 <-> CHF2+H (7) CHF3 <-> CF3+H Two equivalent, barrier-less paths are found for the CH3+H recombination, two inequivalent, barrier-less paths are found for the CH2F+H and CHF2+H recombinations (depending on which side of the radical the hydrogen atom approaches) and only one barrier-less path is found for the CF3+H recombination. The minimum energy path for H atom approaching CF3 from the concave side is predicted to have a barrier of 27 kcal/mol. Both the minimum energy path energies and the transitional frequencies as a function of R(CH) for all four reactions are predicted to be quite similar. RP Harding, LB (reprint author), ARGONNE NATL LAB, DIV CHEM, 9700 S CASS AVE, ARGONNE, IL 60439 USA. NR 40 TC 10 Z9 10 U1 1 U2 3 PU VCH PUBLISHERS INC PI DEERFIELD BEACH PA 303 NW 12TH AVE, DEERFIELD BEACH, FL 33442-1788 SN 0005-9021 J9 BER BUNSEN PHYS CHEM JI Ber. Bunsen-Ges. Phys. Chem. Chem. Phys. PD MAR PY 1997 VL 101 IS 3 BP 363 EP 371 PG 9 WC Chemistry, Physical SC Chemistry GA WR854 UT WOS:A1997WR85400007 ER PT J AU Wagner, AF Harding, LB Robertson, SH Wardlaw, DM AF Wagner, AF Harding, LB Robertson, SH Wardlaw, DM TI The influence of hindered rotations on recombination/dissociation kinetics SO BERICHTE DER BUNSEN-GESELLSCHAFT-PHYSICAL CHEMISTRY CHEMICAL PHYSICS LA English DT Article; Proceedings Paper CT Discussion Meeting of the Deutsche-Bunsen-Gesellschaft on Unimolecular Reactions CY OCT 21-24, 1996 CL TUTZING, GERMANY SP Deut Bunsen Gesell DE chemical kinetics; elementary reactions; radicals ID FLEXIBLE TRANSITION-STATES; CORRELATED MOLECULAR CALCULATIONS; REACTION COORDINATE FRAMEWORK; KASSEL-MARCUS THEORY; GAUSSIAN-BASIS SETS; RADICAL RECOMBINATION; RATE CONSTANTS; BOND LENGTH; LOOSENESS; IMPLEMENTATION AB The variational canonical flexible transition state theory expressions for the thermal reaction rate constant are reviewed and then applied to the barrier-less recombination reactions H + CCH, H + CF3, and CH + H-2. The rate constant expressions can classically accommodate any description of the hindering potential governing relative orientation changes between the reactants at a given distance. The distance held fixed during the relative orientation changes can be fully optimized. The three applications display comparable and large variations between the harmonic oscillator and free rotor limits of the hindering potential. The actual hindering potentials are all derived from similar ab initio electronic structure calculations. With these potentials, the rate constant for H+CF3 is somewhat free-rotor like, the rate constant for CH+H-2 is mostly harmonic-oscillator like, and the rate constant for H+CCH is largely in between these two limits. C1 UNIV LEEDS, SCH CHEM, LEEDS LS2 9JT, W YORKSHIRE, ENGLAND. QUEENS UNIV, DEPT CHEM, KINGSTON, ON K7L 3N6, CANADA. RP Wagner, AF (reprint author), ARGONNE NATL LAB, DIV CHEM, 9700 S CASS AVE, ARGONNE, IL 60439 USA. NR 43 TC 11 Z9 11 U1 0 U2 0 PU VCH PUBLISHERS INC PI DEERFIELD BEACH PA 303 NW 12TH AVE, DEERFIELD BEACH, FL 33442-1788 SN 0005-9021 J9 BER BUNSEN PHYS CHEM JI Ber. Bunsen-Ges. Phys. Chem. Chem. Phys. PD MAR PY 1997 VL 101 IS 3 BP 391 EP 399 PG 9 WC Chemistry, Physical SC Chemistry GA WR854 UT WOS:A1997WR85400010 ER PT J AU Klippenstein, SJ Allen, WD AF Klippenstein, SJ Allen, WD TI Variable reaction coordinate direct RRKM theory SO BERICHTE DER BUNSEN-GESELLSCHAFT-PHYSICAL CHEMISTRY CHEMICAL PHYSICS LA English DT Article; Proceedings Paper CT Discussion Meeting of the Deutsche-Bunsen-Gesellschaft on Unimolecular Reactions CY OCT 21-24, 1996 CL TUTZING, GERMANY SP Deut Bunsen Gesell DE chemical kinetics ID POTENTIAL-ENERGY SURFACES; TRANSITION-STATE THEORY; DIRECT DYNAMICS CALCULATIONS; LINEAR DIPOLE ROTORS; UNIMOLECULAR REACTION; ELECTRON CORRELATION; PERTURBATION-THEORY; MULTIVARIATE INTERPOLATION; RADICAL RECOMBINATION; IDENTICAL ROTORS AB Various aspects of the direct implementation of the variable reaction coordinate formalism for evaluating the kinetics of barrierless reactions are considered. A new discussion of the decoupling of the conserved and transitional modes within this formalism is provided with sample results for NCNO suggesting an optimum simple procedure for implementing this decoupling. The effort involved in replacing analytic potentials with direct ab initio determinations in the Monte Carlo-based evaluation of the transitional mode partition functions is illustrated through sample calculations for Cl-+CH3Cl, CN+O-2, CN+NO, and (CH2)-C-1+CO. Some procedures for improving the convergence properties of such direct statistical evaluations are also suggested. A brief summary is given of a procedure for directly evaluating the effects of anharmonicities and certain rovibrational couplings on the density of states for the complex. The results from our previous direct variable reaction coordinate RRKM theory study for the dissociation of singlet ketene are slightly revised on the basis of the improved decoupling scheme. The results for both the dissociation rate constant and vibrational distributions are in quantitative agreement (i.e., within 20% throughout the energy ranges considered) with the corresponding recent experimental results. Finally, a possible procedure for making greater use of the ab initio data, and perhaps also obtaining improved convergence, is summarized. C1 UNIV GEORGIA,CTR COMPUTAT QUANTUM CHEM,ATHENS,GA 30602. CASE WESTERN RESERVE UNIV,DEPT CHEM,CLEVELAND,OH 44106. RP Klippenstein, SJ (reprint author), ARGONNE NATL LAB,DIV CHEM,THEORET CHEM GRP,9700 S CASS AVE,ARGONNE,IL 60439, USA. RI Allen, Wesley/C-9867-2010; OI Allen, Wesley/0000-0002-4288-2297; Klippenstein, Stephen/0000-0001-6297-9187 NR 87 TC 26 Z9 26 U1 0 U2 8 PU VCH PUBLISHERS INC PI DEERFIELD BEACH PA 303 NW 12TH AVE, DEERFIELD BEACH, FL 33442-1788 SN 0005-9021 J9 BER BUNSEN PHYS CHEM JI Ber. Bunsen-Ges. Phys. Chem. Chem. Phys. PD MAR PY 1997 VL 101 IS 3 BP 423 EP 437 PG 15 WC Chemistry, Physical SC Chemistry GA WR854 UT WOS:A1997WR85400014 ER PT J AU North, SW Hall, GE AF North, SW Hall, GE TI Photofragment vector correlations as a probe of K-scrambling in unimolecular dissociation SO BERICHTE DER BUNSEN-GESELLSCHAFT-PHYSICAL CHEMISTRY CHEMICAL PHYSICS LA English DT Article; Proceedings Paper CT Discussion Meeting of the Deutsche-Bunsen-Gesellschaft on Unimolecular Reactions CY OCT 21-24, 1996 CL TUTZING, GERMANY SP Deut Bunsen Gesell DE chemical kinetics; spectroscopy; visible; unimolecular reactions ID CHEMICAL-REACTIONS; PHOTODISSOCIATION; DISTRIBUTIONS; DYNAMICS; ORIENTATION; FRAGMENTS; COMPLEXES; MODELS; ATOM AB We discuss the relationship between fragment-rotational polarization and the extent of K-mixing in an energized molecule undergoing unimolecular dissociation at fixed energy and angular momentum. Accurate measurements of the second Legendre moment of the v.j angular correlation are presented for the CN fragments produced in the photoinitiated dissociation of NCCN at 193 nm, as determined by Doppler spectroscopy using a transient frequency modulation technique. The strength of the correlation significantly exceeds what would be observed if all K stales of the dissociating molecule were equally represented. C1 BROOKHAVEN NATL LAB,DEPT CHEM,UPTON,NY 11973. RI North, Simon/G-5054-2012; Hall, Gregory/D-4883-2013 OI North, Simon/0000-0002-0795-796X; Hall, Gregory/0000-0002-8534-9783 NR 29 TC 7 Z9 7 U1 0 U2 1 PU VCH PUBLISHERS INC PI DEERFIELD BEACH PA 303 NW 12TH AVE, DEERFIELD BEACH, FL 33442-1788 SN 0005-9021 J9 BER BUNSEN PHYS CHEM JI Ber. Bunsen-Ges. Phys. Chem. Chem. Phys. PD MAR PY 1997 VL 101 IS 3 BP 459 EP 464 PG 6 WC Chemistry, Physical SC Chemistry GA WR854 UT WOS:A1997WR85400017 ER PT J AU Mellinger, A Hall, MA Wade, EA Moore, CB AF Mellinger, A Hall, MA Wade, EA Moore, CB TI K-conservation in the dissociation of singlet ketene SO BERICHTE DER BUNSEN-GESELLSCHAFT-PHYSICAL CHEMISTRY CHEMICAL PHYSICS LA English DT Article; Proceedings Paper CT Discussion Meeting of the Deutsche-Bunsen-Gesellschaft on Unimolecular Reactions CY OCT 21-24, 1996 CL TUTZING, GERMANY SP Deut Bunsen Gesell DE chemical kinetics; photochemistry; reaction dynamics ID TRANSITION-STATES; PHOTODISSOCIATION; PHOTOFRAGMENTATION; THRESHOLD AB The effect of K-conservation on the photodissociation of ketene has been investigated. Rate constants and photofragment excitation (PHOFEX) spectra have been calculated using phase space theory (PST) in a helicity basis. While the effect of K-conservation on rate constants is relatively subtle, PHOFEX spectra with state-selected reactant molecules appear to provide a feasible way to experimentally resolve the question of K-conservation. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV CHEM SCI,BERKELEY,CA 94720. RP Mellinger, A (reprint author), UNIV CALIF BERKELEY,DEPT CHEM,BERKELEY,CA 94720, USA. NR 17 TC 5 Z9 5 U1 0 U2 1 PU VCH PUBLISHERS INC PI DEERFIELD BEACH PA 303 NW 12TH AVE, DEERFIELD BEACH, FL 33442-1788 SN 0005-9021 J9 BER BUNSEN PHYS CHEM JI Ber. Bunsen-Ges. Phys. Chem. Chem. Phys. PD MAR PY 1997 VL 101 IS 3 BP 465 EP 468 PG 4 WC Chemistry, Physical SC Chemistry GA WR854 UT WOS:A1997WR85400018 ER PT J AU Li, M Selvin, PR AF Li, M Selvin, PR TI Amine-reactive forms of a luminescent diethylenetriaminepentaacetic acid chelate of terbium and europium: Attachment to DNA and energy transfer measurements SO BIOCONJUGATE CHEMISTRY LA English DT Article ID TIME-RESOLVED FLUORESCENCE; METAL-IONS; DERIVATIVES; MICROSCOPY; ANTIBODY; REAGENTS; LABEL; ISOTHIOCYANATE; MOLECULES; COMPLEX AB An isothiocyanate form of a lanthanide chelate which is highly luminescent when bound to terbium or europium has been synthesized. The chelate consists of diethylenetriaminepentaacetic acid (DTPA) covalently joined to a chromophore, 7-amino-4-methyl-2(1H)-quinolinone (cs124), and to L-p-aminophenylalanine, in which the aromatic amine was further converted to an isothiocyanate group. Ethylenediamine was also used in place of aminophenylalanine, but the isothiocyanate formed from the aliphatic amine was significantly less reactive. Site-specific attachments to triglycine and to the 5' ends of amine-modified DNA oligomers have been made. In addition, as an alternative method of coupling to macromolecules, DTPA anhydride-cs124 can be used to react specifically with a 5' amine group on base-deprotected synthetic DNA oligomers. Synthesis and purification is relatively straightforward in both cases, and luminescent properties are favorable for several applications, including as nonisotopic labels, as long-lifetime alternatives to fluorophores in imaging and diagnostics and particularly as donors in luminescence resonance energy transfer. Energy transfer measurements are consistent with previously reported measurements using different attachment mechanisms. C1 UNIV CALIF BERKELEY,CALVIN LAB,DEPT CHEM,BERKELEY,CA 94720. UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV LIFE SCI,BERKELEY,CA. FU NIAMS NIH HHS [AR44420]; NIEHS NIH HHS [2-T32 ES07075]; NIGMS NIH HHS [GM41911] NR 37 TC 81 Z9 82 U1 1 U2 18 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 1043-1802 J9 BIOCONJUGATE CHEM JI Bioconjugate Chem. PD MAR-APR PY 1997 VL 8 IS 2 BP 127 EP 132 DI 10.1021/bc960085m PG 6 WC Biochemical Research Methods; Biochemistry & Molecular Biology; Chemistry, Multidisciplinary; Chemistry, Organic SC Biochemistry & Molecular Biology; Chemistry GA WQ215 UT WOS:A1997WQ21500006 PM 9095352 ER PT J AU Meizel, S AF Meizel, S TI Amino acid neurotransmitter receptor/chloride channels of mammalian sperm and the acrosome reaction SO BIOLOGY OF REPRODUCTION LA English DT Review ID GAMMA-AMINOBUTYRIC-ACID; GABA-A RECEPTOR; BOVINE CHROMAFFIN CELLS; ZONA-PELLUCIDA; GLYCINE RECEPTOR; BINDING-SITES; INTRACELLULAR CALCIUM; HUMAN SPERMATOZOA; PROGESTERONE-RECEPTOR; CYTOSOLIC CHLORIDE AB Two different amino acid neurotransmitter receptor/Cl- channels, a gamma-aminobutyric acid (GABA(A)) receptor-like/Cl- channel and a glycine receptor/Cl- channel, have recently been found in mammalian sperm and shown to be involved in the sperm acrosome reaction (AR), an exocytotic event essential to mammalian fertilization. The identity of the receptor/channel involved in the AR depends upon the stimulatory ligand. The AR initiated by the egg zona pellucida requires the participation of the sperm glycine receptor/Cl- channel, whereas the AR initiated by another putative physiological AR initiator, progesterone, involves the sperm GABA(A) receptor-like/Cl- channel. Cl- efflux through the latter has been shown to occur during the progesterone-initiated AR. Activation of sperm amino acid neurotransmitter receptor/Cl- channels may result in plasma membrane depolarization and thereby exert at least a partial control over voltage-sensitive sperm Ca2+ channels and Ca2+ influx important to the AR. RP Meizel, S (reprint author), LAWRENCE LIVERMORE NATL LAB,SCH MED,DEPT CELL BIOL & HUMAN ANAT,DAVIS,CA 95616, USA. FU NICHD NIH HHS [HD-23098] NR 86 TC 82 Z9 82 U1 5 U2 6 PU SOC STUDY REPRODUCTION PI MADISON PA 1603 MONROE ST, MADISON, WI 53711-2021 SN 0006-3363 J9 BIOL REPROD JI Biol. Reprod. PD MAR PY 1997 VL 56 IS 3 BP 569 EP 574 DI 10.1095/biolreprod56.3.569 PG 6 WC Reproductive Biology SC Reproductive Biology GA WJ783 UT WOS:A1997WJ78300001 PM 9046998 ER PT J AU Madigan, D York, JC AF Madigan, D York, JC TI Bayesian methods for estimation of the size of a closed population SO BIOMETRIKA LA English DT Article DE Bayesian graphical model; capture-recapture; chordal graph; closed population estimation; contingency table; decomposable log-linear model; Markov distribution ID CAPTURE-RECAPTURE MODEL; CONTINGENCY-TABLES; GRAPHICAL MODELS; UNCERTAINTY; SELECTION; CENSUS AB A Bayesian methodology for estimating the size of a closed population from multiple incomplete administrative lists is proposed. The approach allows for a variety of dependence structures between the lists, can make use of covariates, and explicitly accounts for model uncertainty. Interval estimates from this approach are compared to frequentist and previously published Bayesian approaches. Several examples are considered. C1 PACIFIC NW LAB, RICHLAND, WA 99352 USA. RP Madigan, D (reprint author), UNIV WASHINGTON, DEPT STAT, BOX 354322, SEATTLE, WA 98195 USA. NR 28 TC 40 Z9 42 U1 0 U2 2 PU BIOMETRIKA TRUST PI LONDON PA UNIV COLLEGE LONDON GOWER ST-BIOMETRIKA OFFICE, LONDON, ENGLAND WC1E 6BT SN 0006-3444 J9 BIOMETRIKA JI Biometrika PD MAR PY 1997 VL 84 IS 1 BP 19 EP 31 DI 10.1093/biomet/84.1.19 PG 13 WC Biology; Mathematical & Computational Biology; Statistics & Probability SC Life Sciences & Biomedicine - Other Topics; Mathematical & Computational Biology; Mathematics GA WT082 UT WOS:A1997WT08200002 ER PT J AU Simel, EJ Saidak, LR Tuskan, GA AF Simel, EJ Saidak, LR Tuskan, GA TI Method of extracting genomic DNA from non-germinated gymnosperm and angiosperm pollen SO BIOTECHNIQUES LA English DT Article ID MESSENGER-RNA; SPERM CELLS; SPOROPLASTS C1 OAK RIDGE NATL LAB,DIV ENVIRONM SCI,OAK RIDGE,TN 37831. OAK RIDGE ASSOCIATED UNIV,OAK RIDGE,TN. RI Tuskan, Gerald/A-6225-2011 OI Tuskan, Gerald/0000-0003-0106-1289 NR 18 TC 7 Z9 8 U1 0 U2 4 PU EATON PUBLISHING CO PI NATICK PA 154 E. CENTRAL ST, NATICK, MA 01760 SN 0736-6205 J9 BIOTECHNIQUES JI Biotechniques PD MAR PY 1997 VL 22 IS 3 BP 390 EP & PG 3 WC Biochemical Research Methods; Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA WM672 UT WOS:A1997WM67200002 PM 9067005 ER PT J AU Gailey, PC Miller, EJ Griffin, GD AF Gailey, PC Miller, EJ Griffin, GD TI Low-cost system for real-time monitoring of luciferase gene expression SO BIOTECHNIQUES LA English DT Article ID FIREFLY LUCIFERASE; ESCHERICHIA-COLI; REPORTER GENE; CELLS AB In some mammalian cells transfected with luciferase reporter genes, the luciferase/luciferin reaction in a cell monolayer produces a very small light flux. While the low light levels are often measureable with single-photon counting cameras, these devices are expensive and may require long averaging times to acquire an image. We describe an approach for real-time monitoring of light produced by luciferase gene expression in intact, cultured cells using readily available and relatively inexpensive components. The system uses a single-photon counting photomultiplier tube with built-in high voltage supply and photon counting circuitry to rapidly measure average light output from growing cells in a 35-mm culture dish. The fast, accurate and highly sensitive response of the system makes it useful for studying the dynamics of gene expression over time periods ranging from minutes to days. RP Gailey, PC (reprint author), OAK RIDGE NATL LAB,DIV ENERGY,POB 2008,OAK RIDGE,TN 37831, USA. NR 12 TC 2 Z9 2 U1 0 U2 1 PU EATON PUBLISHING CO PI NATICK PA 154 E. CENTRAL ST, NATICK, MA 01760 SN 0736-6205 J9 BIOTECHNIQUES JI Biotechniques PD MAR PY 1997 VL 22 IS 3 BP 528 EP 534 PG 7 WC Biochemical Research Methods; Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA WM672 UT WOS:A1997WM67200029 PM 9067033 ER PT J AU Sajonz, P GuanSajonz, H Zhong, GM Guiochon, G AF Sajonz, P GuanSajonz, H Zhong, GM Guiochon, G TI Application of the shock layer theory to the determination of the mass transfer rate coefficient and its concentration dependence for proteins on anion exchange columns SO BIOTECHNOLOGY PROGRESS LA English DT Article ID LIQUID-CHROMATOGRAPHY; LIGHT-SCATTERING; FRONTAL ANALYSIS; DIFFUSION; SYSTEMS; THICKNESS; SINGLE AB The extension of the shock layer theory to systems having a slow mass transfer kinetics and a concentration-dependent rate coefficient is discussed. Experiments were carried out with bovine serum albumin on two anion exchangers, TSK-GEL-DEAE-5PW and Resource-Q. The adsorption isotherm data, determined by single-step frontal analysis, could be fitted to simplified bi-langmuir equations with very small residuals. A lumped kinetic model (solid film linear driving force model, with rate coefficient k(f)) was used to account for the mass transfer kinetics. The profile of each breakthrough curve (BC) was fitted to the curve calculated with this transport model and the rate coefficient k(f) obtained by identification. A linear dependence of k(f) on the average: concentration of the step of the BC was found. The shock layer thicknesses (SLT) calculated for different relative concentrations agreed very well with the experimental results. This justifies the use of the SLT for: the direct determination of rate coefficients. C1 UNIV TENNESSEE,DEPT CHEM,KNOXVILLE,TN 37996. OAK RIDGE NATL LAB,DIV ANALYT CHEM,OAK RIDGE,TN 37831. UNIV SAARLAND,D-66123 SAARBRUCKEN,GERMANY. NR 19 TC 38 Z9 38 U1 1 U2 7 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 8756-7938 J9 BIOTECHNOL PROGR JI Biotechnol. Prog. PD MAR-APR PY 1997 VL 13 IS 2 BP 170 EP 178 DI 10.1021/bp970002w PG 9 WC Biotechnology & Applied Microbiology; Food Science & Technology SC Biotechnology & Applied Microbiology; Food Science & Technology GA WR855 UT WOS:A1997WR85500008 ER PT J AU Li, RC AF Li, RC TI Relative perturbation bounds for the unitary polar factor SO BIT LA English DT Article DE polar decomposition; relative perturbation theory; scaling ID ACCURATE SINGULAR-VALUES; DECOMPOSITION; MATRICES AB Let B be an m x n (m greater than or equal to n) complex (or real) matrix. It is known that there is a unique polar decomposition B = QH, where Q*Q = I, the n x n identity matrix, and H is positive definite, provided B has full column rank. Existing perturbation bounds suggest that in the worst case, for complex matrices the change in Q be proportional to the reciprocal of B's least singular value, or the reciprocal of the sum of B's least and second least singular values if matrices are real. However, there are situations where this unitary polar factor is much more accurately determined by the data than the existing perturbation bounds would indicate. In this paper the following question is addressed: how much may Q change if B is perturbed to (B) over tilde = D*1BD2, where D-1 and D-2 are nonsingular and close to the identity matrices of suitable dimensions? It is shown that for a such kind of perturbation, the change in Q is bounded only by the distances from D-1 and D-2 to identity matrices and thus is independent of B's singular values. Such perturbation is restrictive, but not unrealistic. We show how a frequently used scaling technique yields such a perturbation and thus scaling may result in better-conditioned polar decompositions. C1 OAK RIDGE NATL LAB,MATH SCI SECT,OAK RIDGE,TN 37831. NR 15 TC 16 Z9 20 U1 0 U2 0 PU BIT FOUNDATION PI COPENHAGEN PA POSTBOX 113, DK-1004 COPENHAGEN, DENMARK SN 0006-3835 J9 BIT JI Bit PD MAR PY 1997 VL 37 IS 1 BP 67 EP 75 DI 10.1007/BF02510173 PG 9 WC Computer Science, Software Engineering; Mathematics, Applied SC Computer Science; Mathematics GA WK055 UT WOS:A1997WK05500006 ER PT J AU Schrier, SL Bunyaratvej, A Khuhapinant, A Fucharoen, S Aljurf, M Snyder, LM Keifer, CR Ma, L Mohandas, N AF Schrier, SL Bunyaratvej, A Khuhapinant, A Fucharoen, S Aljurf, M Snyder, LM Keifer, CR Ma, L Mohandas, N TI The unusual pathobiology of hemoglobin constant spring red blood cells SO BLOOD LA English DT Article ID BETA-THALASSEMIA; ALPHA-THALASSEMIA; MEMBRANE SKELETON; PROTEIN DEFECTS; H DISEASE; VOLUME; ERYTHROCYTES; GENE AB Hemoglobin Constant Spring (HbCS) is the most common nondeletional alpha-thalassemic mutation and is an important cause of HbH-like disease in Southeast Asia. HbCS variants have an almost normal mean cell volume (MCV) and the anemia is more severe when compared with other alpha-thalassemic variants. We explored the pathobiology of HbCS red blood cells (RBCs) because the underlying cause(s) of this MCV ''normalizing'' effect of HbCS and the more severe anemia are not fully explained. HbCS containing RBCs are distinctly overhydrated relative to deletional alpha-thalassemia variants, and the derangement of volume regulation and cell hydration occurs early in erythroid maturation and is fully expressed at the reticulocyte stage. Furthermore, the membrane rigidity and membrane mechanical stability of HbCS containing RBCs is increased when compared with HbH and alpha-thalassemia-1 trait RBCs. In seeking the cause(s) underlying these cellular alterations we analyzed membranes from HbCS and deletional alpha-thalassemic variants and found that in addition to oxidized beta-globin chains, oxidized alpha(cs)-globin chains are also associated with the membranes and their skeletons in HbCS containing RBCs. We propose that the membrane pathology of HbCS variants is caused by combination of the deleterious effects induced by membrane-bound oxidized alpha(cs)- and beta-globin chains. The membrane alterations induced by alpha(cs) chains are more akin to those induced by beta(A)-globin chains than those induced by the alpha(A)-globin chains that accumulate in the beta-thalassemias. Thus, each globin chain, alpha(cs), alpha(A), beta(A), appears to produce its own form of membrane perturbation. (C) 1997 by The American Society of Hematology. C1 LAWRENCE BERKELEY LAB,BERKELEY,CA. UNIV MASSACHUSETTS,MED CTR,WORCESTER,MA. MAHIDOL UNIV,RAMATHIBODI HOSP,FAC MED,BANGKOK 10400,THAILAND. SIRIRAJ HOSP,BANGKOK,THAILAND. RP Schrier, SL (reprint author), STANFORD UNIV,SCH MED,DIV HEMATOL,STANFORD,CA 94305, USA. FU NHLBI NIH HHS [HL 31579]; NIDDK NIH HHS [DK 26263, DK 13682] NR 26 TC 71 Z9 75 U1 0 U2 1 PU W B SAUNDERS CO PI PHILADELPHIA PA INDEPENDENCE SQUARE WEST CURTIS CENTER, STE 300, PHILADELPHIA, PA 19106-3399 SN 0006-4971 J9 BLOOD JI Blood PD MAR 1 PY 1997 VL 89 IS 5 BP 1762 EP 1769 PG 8 WC Hematology SC Hematology GA WK477 UT WOS:A1997WK47700036 PM 9057661 ER PT J AU Reidys, C Stadler, PF Schuster, P AF Reidys, C Stadler, PF Schuster, P TI Generic properties of combinatory maps: Neutral networks of RNA secondary structures SO BULLETIN OF MATHEMATICAL BIOLOGY LA English DT Article ID EVOLUTIONARY OPTIMIZATION; ERROR THRESHOLDS; LANDSCAPES; SEQUENCES; STATISTICS; REPLICATION; PREDICTION AB Random graph theory is used to model and analyse the relationships between sequences and secondary structures of RNA molecules, which are understood as mappings from sequence space into shape space. These maps are non-invertible since there are always many orders of magnitude more sequences than structures. Sequences folding into identical structures form neutral networks. A neutral network is embedded in the set of sequences that are compatible with the given structure. Networks are modeled as graphs and constructed by random choice of vertices from the space of compatible sequences. The theory characterizes neutral; networks by the mean fraction of neutral neighbors (lambda). The networks are connected and percolate sequence space if the fraction of neutral nearest neighbors exceeds a threshold value (lambda > lambda*). Below threshold (lambda < lambda*), the networks are partitioned into a largest ''giant'' component and several smaller components. Structures are classified as ''common'' or ''rare'' according to the sizes of their pre-images, i.e. according to the fractions of sequences folding into them. The neutral networks of any pair of two different common structures almost touch each other, and, as expressed by the conjecture of shape space covering sequences folding into almost all common structures, can be found in a small ball of an arbitrary location in sequence space. The results from random graph theory are compared to data obtained by folding large samples of RNA sequences. Differences are explained in terms of specific features of RNA molecular structures. (C) 1997 Society for Mathematical Biology. C1 SANTA FE INST, SANTA FE, NM 87501 USA. LOS ALAMOS NATL LAB, LOS ALAMOS, NM 87545 USA. UNIV VIENNA, INST THEORET CHEM, A-1090 VIENNA, AUSTRIA. INST MOL BIOTECHNOL, D-07708 JENA, GERMANY. RI Stadler, Peter F./L-7857-2015 OI Stadler, Peter F./0000-0002-5016-5191 NR 50 TC 153 Z9 154 U1 1 U2 4 PU SPRINGER PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 0092-8240 EI 1522-9602 J9 B MATH BIOL JI Bull. Math. Biol. PD MAR PY 1997 VL 59 IS 2 BP 339 EP 397 DI 10.1007/BF02462007 PG 59 WC Biology; Mathematical & Computational Biology SC Life Sciences & Biomedicine - Other Topics; Mathematical & Computational Biology GA WL280 UT WOS:A1997WL28000007 PM 9116604 ER PT J AU Goss, WP Power, J Ambs, LL Braun, SG Wilkes, KE Yarbrough, DW AF Goss, WP Power, J Ambs, LL Braun, SG Wilkes, KE Yarbrough, DW TI Insulation design: Easter and a lot more exact SO CHEMICAL ENGINEERING LA English DT Article C1 NAIMA,TECH SERV,ALEXANDRIA,VA 22314. OAK RIDGE NATL LAB,OAK RIDGE,TN 37831. TENNESSEE TECHNOL UNIV,COOKEVILLE,TN 38505. RP Goss, WP (reprint author), UNIV MASSACHUSETTS,IND ASSESSMENT CTR,DEPT MECH ENGN,AMHERST,MA 01003, USA. NR 11 TC 0 Z9 0 U1 0 U2 0 PU MCGRAW HILL INC PI NEW YORK PA 1221 AVENUE OF THE AMERICAS, NEW YORK, NY 10020 SN 0009-2460 J9 CHEM ENG-NEW YORK JI Chem. Eng. PD MAR PY 1997 VL 104 IS 3 BP 66 EP 72 PG 7 WC Engineering, Chemical SC Engineering GA WN264 UT WOS:A1997WN26400019 ER PT J AU He, L Anderson, JR Franzen, HF Johnson, DC AF He, L Anderson, JR Franzen, HF Johnson, DC TI Electrocatalysis of anodic oxygen-transfer reactions: Bi3Ru3O11 electrodes in acidic media SO CHEMISTRY OF MATERIALS LA English DT Article ID DOPED LEAD DIOXIDE; RUTHENATE; PYROCHLORES AB Details are reported for the synthesis and characterization of composite materials prepared from powdered Bi3Ru3O11 and a polymeric adhesive fashioned into disk electrodes. The structure of the synthesized material was found to be that of the cubic KSbO3 type on the basis of single-crystal and powder X-ray diffractometry. The surface morphology of a composite electrode was determined to be quite porous on the basis of micrographs obtained using scanning electron microscopy. Voltammetric data obtained for various anodic reactions at these electrodes were examined for evidence that oxidations can occur with transfer of oxygen to the oxidation products in the potential region corresponding to onset of anodic discharge of H2O. Model reactants include iodide, dimethyl sulfoxide, tetramethylene sulfoxide, and manganese(II). The electronic band structure of Bi3Ru3O11 was calculated; it was concluded that mixing of Ru 4d and O 2p orbitals in an antibonding band at the Fermi level facilitates oxygen transfer. C1 IOWA STATE UNIV SCI & TECHNOL,DEPT CHEM,AMES,IA 50011. IOWA STATE UNIV SCI & TECHNOL,AMES LAB,AMES,IA 50011. NR 24 TC 19 Z9 20 U1 1 U2 4 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0897-4756 J9 CHEM MATER JI Chem. Mat. PD MAR PY 1997 VL 9 IS 3 BP 715 EP 722 DI 10.1021/cm960415c PG 8 WC Chemistry, Physical; Materials Science, Multidisciplinary SC Chemistry; Materials Science GA WP138 UT WOS:A1997WP13800012 ER PT J AU Suh, S Hoffman, DM Atagi, LM Smith, DC Liu, JR Chu, WK AF Suh, S Hoffman, DM Atagi, LM Smith, DC Liu, JR Chu, WK TI Precursor oxidation state control of film stoichiometry in the metal-organic chemical vapor deposition of tin oxide thin films SO CHEMISTRY OF MATERIALS LA English DT Article ID TIN(IV) ALKOXIDE COMPOUNDS; SOLID-STATE; SNO2 FILMS; TETRAMETHYLTIN; DIACETATE; GROWTH; TRANSPARENT; MOCVD AB A new tin(IV) hexafluoroisopropoxide complex and a related tin(II) compound were used as low-pressure chemical vapor deposition precursors to tin oxide thin films. The films were characterized by backscattering and elastic recoil spectrometries, Auger and UV-vis spectroscopies, and nuclear reaction analysis. Sn(OCH(CF3)(2))(4)(HNMe(2))(2), a volatile solid (subl 70-75 degrees C at 0.06 Torr), was synthesized in high yield by reacting Sn(NMe(2))(4) with (CF3)(2)-CHOH. A crystal structure determination shows that it has an octahedral structure with trans-amine ligands. Low-pressure chemical vapor deposition using Sn(OCH(CF3)(2))(4)(HNMe(2))(2) and air as precursors gave fluorine-doped tin oxide films (O/Sn = 1.8-2.4; F/Sn = 0.005-0.026) at substrate temperatures of 200-450 degrees C. The films are highly transparent in the visible region (>85%) and have resistivities as low as 2.1 x 10(-3) Omega cm. In contrast to the results obtained for the tin(IV) precursor, the tin(II) compound Sn(OCH(CF3)(2))(2)(HNMe(2)) in combination with air or water vapor gave nonconductive transparent films at substrate temperatures of 180-250 degrees C having composition SnO0.9-1.3F0.1-0.4. These film stoichiometries suggest that hydrolysis was the primary film-forming reaction and that the tin was not oxidized in the deposition process. C1 UNIV HOUSTON, DEPT CHEM, HOUSTON, TX 77204 USA. LOS ALAMOS NATL LAB, LOS ALAMOS, NM 87545 USA. UNIV HOUSTON, TEXAS CTR SUPERCOND, HOUSTON, TX 77204 USA. NR 35 TC 27 Z9 27 U1 1 U2 7 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0897-4756 EI 1520-5002 J9 CHEM MATER JI Chem. Mat. PD MAR PY 1997 VL 9 IS 3 BP 730 EP 735 DI 10.1021/cm960423t PG 6 WC Chemistry, Physical; Materials Science, Multidisciplinary SC Chemistry; Materials Science GA WP138 UT WOS:A1997WP13800014 ER PT J AU Schrock, ME Barrows, ES Rosman, LB AF Schrock, ME Barrows, ES Rosman, LB TI Biota-to-sediment accumulation factors for TCDD and TCDF in worms from 28-day bioaccumulation tests SO CHEMOSPHERE LA English DT Article; Proceedings Paper CT 15th International Symposium on Chlorinated Dioxins, PCB and Related Compounds CY AUG 21-25, 1995 CL EDMONTON, CANADA DE TCDD; TCDF; bioaccumulation; sediment; biota-to-sediment accumulation factor ID CONTAMINANTS AB Sediments from waterbodies near highly urbanized, industrial areas were analyzed for 2,3,7,8-tetrachlorodibenzo-p-dioxin and 2,3,7,8-tetrachlorodibenzofuran (TCDD/TCDF) contamination. Using a dredged material evaluation test, Nereis virens worms were exposed to the contaminated sediment for 28 days and then analyzed for TCDD/TCDF to evaluate the potential bioaccumulation of these contaminants. Levels of TCDD/TCDF in N. virens increased as sediment contamination increased. Average TCDD/TCDF biota-to-sediment accumulation factors (BSAF) based on the tissue TCDD/TCDF concentration, tissue lipid content, sediment TCDD/TCDF concentration, and sediment total organic carbon (TOC) from nine sites with varying dioxin contamination were calculated. These average BSAFs were used to predict the uptake of TCDD/TCDF in N. virens exposed to sediments from a tenth site. (C) 1997 Elsevier Science Ltd. C1 BATTELLE MARINE SCI LAB,SEQUIM,WA 98382. USA CORPS ENGINEERS,NEW YORK,NY 10278. RP Schrock, ME (reprint author), BATTELLE MEM INST,505 KING AVE,COLUMBUS,OH 43201, USA. NR 7 TC 11 Z9 11 U1 0 U2 5 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0045-6535 J9 CHEMOSPHERE JI Chemosphere PD MAR-APR PY 1997 VL 34 IS 5-7 BP 1333 EP 1339 DI 10.1016/S0045-6535(97)00430-X PG 7 WC Environmental Sciences SC Environmental Sciences & Ecology GA WR677 UT WOS:A1997WR67700036 ER PT J AU Carrado, KA Thiyagarajan, P Song, K AF Carrado, KA Thiyagarajan, P Song, K TI A study of organo-hectorite clay crystallization SO CLAY MINERALS LA English DT Article ID HYDROTHERMAL CRYSTALLIZATION; LOW-TEMPERATURES; SAPONITES; GELS AB A method has been developed to synthesize organo-hectorite clays directly from a Mg-silicate gel containing organic or organometallic molecules that are expected to be incorporated within the interlayer space. Complete crystallization occurs upon aqueous reflux for 48 h. The progress of clay layer formation was monitored by X-ray powder diffraction (XRD), differential thermal gravimetry (DTG), and infrared (IR) spectroscopy. Evidence of clay XRD peaks occurs after just 4 h of hydrothermal treatment, and Mg(OH)(2) is no longer observable after 14 h. Observable changes in DTG and IR occur at about this time as well. Warren line-shape analysis of the 110 reflection indicates that when growth is complete the clay lamellae are on average similar to 50% and 25% of the size of natural hectorites and montmorillonites, respectively. The N-2 BET surface areas for all materials are also compared. Small angle neutron scattering shows that addition of tetraethyl ammonium (TEA) ions does not alter the structural integrity over that of the purely inorganic form of Li-hectorite, but that use of a cationic polymer does significantly alter the microstructure. The effect of temperature is critical, for at room temperature only the layered Mg hydroxide mineral brucite crystallizes unless very long time scales are used. The crystallizations carried out at room temperature show that clay will form after about 3 months, but that the presence of organics (at least TEA) acts to hinder this process greatly. The role of the organic molecules on silicate clay layer formation is compared with the role of organics in zeolite synthesis. C1 ARGONNE NATL LAB, DIV INTENSE PULSED NEUTRON SOURCE, ARGONNE, IL 60439 USA. RP Carrado, KA (reprint author), ARGONNE NATL LAB, DIV CHEM, 9700 S CASS AVE, ARGONNE, IL 60439 USA. NR 22 TC 43 Z9 45 U1 0 U2 10 PU MINERALOGICAL SOC PI TWICKENHAM PA 12 BAYLIS MEWS, AMYAND PARK ROAD,, TWICKENHAM TW1 3HQ, MIDDLESEX, ENGLAND SN 0009-8558 J9 CLAY MINER JI Clay Min. PD MAR PY 1997 VL 32 IS 1 BP 29 EP 40 DI 10.1180/claymin.1997.032.1.05 PG 12 WC Chemistry, Physical; Geosciences, Multidisciplinary; Mineralogy SC Chemistry; Geology; Mineralogy GA WN232 UT WOS:A1997WN23200005 ER PT J AU Baxter, LL Mitchell, RE Fletcher, TH AF Baxter, LL Mitchell, RE Fletcher, TH TI Release of inorganic material during coal devolatilization SO COMBUSTION AND FLAME LA English DT Article ID PULVERIZED-COAL; BROWN COALS; COMBUSTION; DECOMPOSITION; PYROLYSIS AB Experimental results presented in this paper indicate that coal devolatilization products convectively remove a fraction of the nonvolatile components of inorganic material atomically dispersed in the coal matrix. Results from three facilities burning six different coals illustrate this mechanism of ash transformation and release from coal particles. Titanium is chosen to illustrate this type of mass release from coal particles on the basis of its low volatility and mode of occurrence in the coal. During moderate rates of devolatilization (10(4) K/s heating rate), no significant loss of titanium is noted. At more rapid rates of heating/devolatilization (10(5) K/s) a consistent but minor (3%-4%) loss of titanium is noted. During rapid devolatilization (5 x 10(5) K/s and higher), significant (10%-20%) amounts of titanium leave the coal. The loss of titanium monitored in coals ranging in rank from subbituminous to high-volatile bituminous coals and under conditions typical of pulverized-coal combustion. The amount of titanium lost during devolatilization exhibits a complex rank dependence. These results imply that other atomically dispersed material (alkali and alkaline earth elements) may undergo similar mechanisms of transformation and release. Copyright (C) 1997 by The Combustion Institute. RP Baxter, LL (reprint author), SANDIA NATL LABS,COMBUST RES FACIL,POB 969 7011 EAST AVE,LIVERMORE,CA 94551, USA. RI Baxter, Larry/C-8567-2009 OI Baxter, Larry/0000-0002-0453-2659 NR 29 TC 12 Z9 12 U1 2 U2 17 PU ELSEVIER SCIENCE INC PI NEW YORK PA 655 AVENUE OF THE AMERICAS, NEW YORK, NY 10010 SN 0010-2180 J9 COMBUST FLAME JI Combust. Flame PD MAR PY 1997 VL 108 IS 4 BP 494 EP 502 DI 10.1016/0010-2180(95)00120-4 PG 9 WC Thermodynamics; Energy & Fuels; Engineering, Multidisciplinary; Engineering, Chemical; Engineering, Mechanical SC Thermodynamics; Energy & Fuels; Engineering GA WK662 UT WOS:A1997WK66200008 ER PT J AU Dubois, PF AF Dubois, PF TI The future of scientific programming SO COMPUTERS IN PHYSICS LA English DT Article RP Dubois, PF (reprint author), LAWRENCE LIVERMORE NATL LAB,X DIV,LIVERMORE,CA 94550, USA. NR 0 TC 2 Z9 2 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0894-1866 J9 COMPUT PHYS JI Comput. Phys. PD MAR-APR PY 1997 VL 11 IS 2 BP 168 EP 173 PG 6 WC Computer Science, Interdisciplinary Applications; Physics, Multidisciplinary; Physics, Mathematical SC Computer Science; Physics GA WR042 UT WOS:A1997WR04200015 ER PT J AU Davis, EP Boopathy, R Manning, J AF Davis, EP Boopathy, R Manning, J TI Use of trinitrobenzene as a nitrogen source by Pseudomonas vesicularis isolated from soil SO CURRENT MICROBIOLOGY LA English DT Article ID SP B-STRAIN; NITROAROMATIC COMPOUNDS; MICROBIAL TRANSFORMATION; PHANEROCHAETE-CHRYSOSPORIUM; PARA-NITROPHENOL; 2,4,6-TRINITROTOLUENE; BIODEGRADATION; BACTERIA; TNT; 2,4-DINITROTOLUENE AB An aerobic Gram-negative bacterium identified as Pseudomonas vesicularis was isolated from soil contaminated with 2,4,6-trinitrotoluene (TNT) and 1,3,5-trinitrobenzene (TNB). This bacterium used TNB as the sole source of nitrogen. The TNB was metabolized within 80 h of incubation. The major metabolites produced were dinitroaniline, dinitrobenzene (DNB), nitroaniline, nitrobenzene (NB), and ammonia. The concentrations of DNB and NE produced in the culture medium were nearly stoichiometric. The ammonia concentration in the culture medium increased during the course of incubation. The end product of TNB metabolism was NE, which did not undergo further degradation even after long incubation time. This bacterium could be used in a syntrophic culture system with other NB-degrading bacteria to remove TNB completely from soil and water at contaminated sites. C1 ARGONNE NATL LAB,DIV ENVIRONM RES,ARGONNE,IL 60439. UNIV NOTRE DAME,DEPT BIOL SCI,NOTRE DAME,IN 46556. NR 33 TC 20 Z9 21 U1 0 U2 1 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 SN 0343-8651 J9 CURR MICROBIOL JI Curr. Microbiol. PD MAR PY 1997 VL 34 IS 3 BP 192 EP 197 DI 10.1007/s002849900167 PG 6 WC Microbiology SC Microbiology GA WH808 UT WOS:A1997WH80800011 PM 9009074 ER PT J AU Seidl, MA Finkel, RC Caffee, MW Hudson, GB Dietrich, WE AF Seidl, MA Finkel, RC Caffee, MW Hudson, GB Dietrich, WE TI Cosmogenic isotope analyses applied to river longitudinal profile evolution: Problems and interpretations SO EARTH SURFACE PROCESSES AND LANDFORMS LA English DT Article DE cosmogenic isotopes; river incision; longitudinal profile development; landscape evolution ID TERRESTRIAL ROCKS; PRODUCTION-RATES; EXPOSURE AGES; SUMMIT LAVAS; BE-10; INSITU; HE-3; HELIUM; ANTARCTICA; EROSION AB The use of cosmogenic isotopes to determine surface exposure ages has grown rapidly in recent years. The extent to which cosmogenic nuclides can distinguish between mechanistic hypotheses of landscape evolution is an important issue in geomorphology. We present a case study to determine whether surface exposure dating techniques can elucidate the role knickpoint propagation plays in longitudinal profile evolution. Cosmogenically produced Be-10, Al-26, Cl-36, H-3 and Ne-21 were measured in olivines collected from 5.2 Ma basalt flows on Kauai, Hawaii. Several obstacles had to be overcome prior to the measurement of in situ-produced radionuclides, including removal of meteoric Be-10 from the olivine grains. Discrepancies between the radionuclide and noble gas data may suggest limits for exposure dating. Approximate surface exposure ages calculated from the nuclide concentrations indicate that large boulders may remain in the Hawaiian valley below the knickpoint for hundreds of thousands of years. The ages of samples collected above the knickpoint are consistent with estimates of erosion based on the preservation of palaeosurfaces. Although the exposure ages can neither confirm nor reject the knickpoint hypothesis, boulder ages downstream of the knickpoint are consistent with a wave of incision passing upvalley. The long residence time off the coarse material in the valley bottom further suggests that knickpoint propagation beneath a boulder pile is necessary for incision of the bedrock underlying the boulders to occur. (C) 1997 by John Wiley & Sons, Ltd. C1 LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550. UNIV CALIF BERKELEY,DEPT GEOL & GEOPHYS,BERKELEY,CA 94720. RP Seidl, MA (reprint author), RUTGERS STATE UNIV,DEPT GEOL SCI,NEW BRUNSWICK,NJ 08903, USA. RI Caffee, Marc/K-7025-2015 OI Caffee, Marc/0000-0002-6846-8967 NR 40 TC 34 Z9 35 U1 1 U2 13 PU JOHN WILEY & SONS LTD PI W SUSSEX PA BAFFINS LANE CHICHESTER, W SUSSEX, ENGLAND PO19 1UD SN 0197-9337 J9 EARTH SURF PROC LAND JI Earth Surf. Process. Landf. PD MAR PY 1997 VL 22 IS 3 BP 195 EP 209 DI 10.1002/(SICI)1096-9837(199703)22:3<195::AID-ESP748>3.0.CO;2-0 PG 15 WC Geography, Physical; Geosciences, Multidisciplinary SC Physical Geography; Geology GA WP501 UT WOS:A1997WP50100002 ER PT J AU Megonigal, JP Conner, WH Kroeger, S Sharitz, RR AF Megonigal, JP Conner, WH Kroeger, S Sharitz, RR TI Aboveground production in Southeastern floodplain forests: A test of the subsidy-stress hypothesis SO ECOLOGY LA English DT Article DE flooding regime and net primary production; flooding stress and floodplain forest production; floodplain forests, southeastern United States; hydrologic disturbance and net primary production; hydrologic disturbance in floodplain forests; Louisiana, USA; net primary production in bottomland hardwood forest; South Carolina, USA ID DISTICHUM L RICH; SYLVATICA VAR-BIFLORA; FRESH-WATER WETLANDS; TAXODIUM-DISTICHUM; NYSSA-SYLVATICA; SWAMP-FOREST; BALD-CYPRESS; HYDROLOGIC REGIME; SOUTHERN ILLINOIS; FLOODING REGIMES AB It has been hypothesized that periodically flooded forests have higher rates of aboveground net primary production than upland forests and near-continuously flooded forests, but a competing hypothesis holds that the benefits of periodic inputs of nutrients and water may be diminished by stresses associated with anaerobic soils or drought. To test these hypotheses, we measured groundwater table depths and aboveground productivity in floodplain forests of South Carolina and Louisiana. We established paired plots on locally dry, intermediate, and wet topographic positions across three hydrologic transects in each state. These plots encompassed upland hardwood, bottomland hardwood, and cypress swamp forests. Measurements of leaf litterfall, wood production, and groundwater table depth were made in 1987 and 1988. We then used mean growing-season water depth (MWD) to group the plots into three classes: wet (>0 cm), intermediate (0 to -60 cm), and dry (<-60 cm). Aboveground net primary production (NPP) on wet plots (2-yr mean +/- 1 SD = 675 +/- 271 g . m(-2). yr(-1)) was significantly lower than on intermediate and dry plots (P less than or equal to 0.02). There was no significant difference between intermediate and dry plots (107 +/- 189 and 1038 +/- 91) g . m(-2). yr(-1), respectively). In addition, aboveground NPP on intermediate plots was not significantly different from 22 temperate upland forests in the literature. Combining our data with data from the literature, we found that aboveground NPP on wet plots was negatively related to MWD with a slope of -5 g . m(-2). yr(-1). cm(-1). On sites with evidence of hydrologic disturbance (>25% dead stems) the slope of this line was 5 times greater (-24 g . m(-2). yr(-1). cm(-1)). We conclude that the subsidy-stress hypothesis does not adequately describe patterns of NPP across Southeastern U.S. floodplain forests. Conditions of periodic flooding and flowing water do not often lead to high rates of productivity compared with upland forests. However, extensive flooding is nearly always a significant stress on forest productivity, particularly when the flooding regime has been recently perturbed through levee construction or impoundment. Our data support a more complex interaction between subsidy and stress factors. C1 DUKE UNIV,DEPT BOT,DURHAM,NC 27708. BARUCH FOREST SCI INST,GEORGETOWN,SC 29442. SAVANNAH RIVER ECOL LAB,AIKEN,SC 29802. NR 81 TC 129 Z9 134 U1 3 U2 26 PU ECOLOGICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE, NW, STE 400, WASHINGTON, DC 20036 SN 0012-9658 J9 ECOLOGY JI Ecology PD MAR PY 1997 VL 78 IS 2 BP 370 EP 384 PG 15 WC Ecology SC Environmental Sciences & Ecology GA WN754 UT WOS:A1997WN75400004 ER PT J AU Karban, R EnglishLoeb, G AF Karban, R EnglishLoeb, G TI Tachinid parasitoids affect host plant choice by caterpillars to increase caterpillar survival SO ECOLOGY LA English DT Article DE behavior; host plant choice; nonlethal parasitism; parasite-induced altered behavior; parasitoid; preference vs. performance; Tachinidae; tritrophic interactions ID BEHAVIOR; EVOLUTION; SELECTION; RESPONSES; DEFENSE AB Current models of parasite-host interactions generally emphasize considerations of parasite virulence and parasite transmission rather than host responses to attack. We describe a situation in which parasitism causes a host to change its feeding behavior and this change improves the expected fitness of the host and probably the fitness of its parasites. We have found that a tachinid parasitoid (Thelaira americana) often emerges from its caterpillar host (Platyprepia virginalis) without killing the host. Whether the host caterpillar survives its parasites depends in part on what it has been eating. Unparasitized caterpillars were more likely to survive to adulthood when feeding on lupine, whereas parasitized caterpillars were more likely to survive on poison hemlock. Development time and pupal masses of caterpillars (both parasitized and unparasitized) were not found to be affected by the host plants that they fed on. Survival of fly larvae in caterpillars that we determined were parasitized using ultrasound was not affected by host plant. However, fly pupae that emerged from caterpillars that had been reared on hemlock were heavier than those emerging from lupine-fed caterpillars. This was due primarily to the direct effect of diet on the flies and less so to the indirect benefit to flies whose host caterpillars survived their parasites by feeding on hemlock. Parasitized caterpillars were more likely to select hemlock, and unparasitized caterpillars were more likely to select lupine when offered both host plants in field tests. These results were consistent for the two years that the choice experiments were conducted. These results were also consistent with the hypothesis that caterpillars change their food plant choices so as to increase their conditional success. Conditional food choices that increase success depending upon parasite load are well accepted for humans, controversial for other primates, and unknown for insects. If caterpillars alter their host plant choices as a result of their parasite load, then this phenomenon could help to explain the evolution of host plant choices that have defied explanation in the past. Such a suggestion assumes that nonlethal parasitism is a common phenomenon. We believe that this may be the case since we did not detect the nonlethal nature of this interaction until we began the unconventional practice of rearing in the field. Other workers have described nonlethal parasitism for several tachinid-host systems, and many families of flies are similar to tachinids except that their hosts are vertebrates; these interactions are nonlethal. Future empirical work, as well as models of parasite-host interactions, should consider the possibility that hosts alter their plant choices depending upon their parasite loads. C1 CORNELL UNIV, DEPT ENTOMOL, ITHACA, NY 14853 USA. NEW YORK STATE AGR EXPTL STN, GENEVA, NY 14456 USA. RP Karban, R (reprint author), LAWRENCE LIVERMORE NATL LAB, DEPT ENTOMOL, DAVIS, CA 95616 USA. NR 62 TC 66 Z9 67 U1 1 U2 25 PU ECOLOGICAL SOC AMER PI WASHINGTON PA 1990 M STREET NW, STE 700, WASHINGTON, DC 20036 USA SN 0012-9658 EI 1939-9170 J9 ECOLOGY JI Ecology PD MAR PY 1997 VL 78 IS 2 BP 603 EP 611 PG 9 WC Ecology SC Environmental Sciences & Ecology GA WN754 UT WOS:A1997WN75400023 ER PT J AU Clark, T Johnson, DC AF Clark, T Johnson, DC TI Activation of titanium electrodes for voltammetric detection of oxygen and hydrogen peroxide in alkaline media SO ELECTROANALYSIS LA English DT Article DE titanium; voltammetry; oxygen; hydrogen peroxide ID REDUCTION AB Bright, freshly-polished Ti electrodes give minimal cathodic response for O-2 and H2O2 in 1.0 M NaOH. However, the response is increased gradually by repeated application of a triangular waveform within the approximate potential limits of O-2 response (ca. -1.5 to -0.7 V vs. SCE). This same voltammetric pretreatment applied for excessive periods results in formation of golden films on the Ti surfaces that are active for reduction of O-2 and H2O2. Levich plots of cathodic current for O-2 and H2O2 at rotated golden-Ti disk electrodes in 1.0 M NaOH (-1.35 V) are linear over a large range of rotational velocity (42 to 513 rad s(-1)), a behavior considered to be indicative of fast heterogeneous kinetics. Ring-disk data demonstrate that a small amount of H2O2 is produced throughout the potential region for O-2 reduction and H2O2 is concluded to be an intermediate product in the O-2-reduction mechanism. These observations are consistent with those reported previously for single-crystal TiO2 electrodes. C1 IOWA STATE UNIV,DEPT CHEM,AMES,IA 50011. IOWA STATE UNIV,AMES LAB,AMES,IA 50011. NR 18 TC 16 Z9 16 U1 3 U2 8 PU WILEY-V C H VERLAG GMBH PI WEINHEIM PA POSTFACH 10 11 61, D-69451 WEINHEIM, GERMANY SN 1040-0397 J9 ELECTROANAL JI Electroanalysis PD MAR PY 1997 VL 9 IS 4 BP 273 EP 278 DI 10.1002/elan.1140090402 PG 6 WC Chemistry, Analytical; Electrochemistry SC Chemistry; Electrochemistry GA WY092 UT WOS:A1997WY09200001 ER PT J AU Pamplin, KL Johnson, DC AF Pamplin, KL Johnson, DC TI The coulometric determination of chemical oxygen demand SO ELECTROANALYSIS LA English DT Article DE chemical oxygen demand; coulometry; chromium ID FLOW-INJECTION ANALYSIS; WATERS AB The chemical oxygen demand (COD) of solutions containing various organic compounds is calculated from the net faradaic charge (Q(net)) estimated for the total electrolytic oxidation of Cr-III generated during oxidative degradation of the organic compounds in acidic media containing excess Cr-VI. Values of Q(net) for conversion of Cr-III to Cr-VI are estimated from the linearized chronoamperometric data plotted as ln{i(tot,t)} vs. t. This procedure is preferred over determinations of Q(net) from the total integrals of i(tot) over the entire electrolysis period because of large errors that can result from uncertainty in the background current (i(bkg)) for t --> infinity. The proposed coulometric procedure offers the benefit that reagent solutions can be reused, thereby minimizing the need for disposal of wastes containing toxic Cr-VI. This procedure was applied in a single digest solution for consecutive determinations of COD. Average COD values for potassium acid phthalate and glucose were 103.8 % (s = 6.0, N = 10) and 100.2 % (s = 4.2, N = 11), respectively, based on the theoretical degradation to CO2. In comparison for these same samples, an EPA approved method, based on colorimetric determination of Cr-III, gave COD values of 101.4 % (S = 1.4, N = 5) and 100.1 % (s = 1.4, N = 5) of the theoretical. Statistical tests indicate no significant difference in the COD values determined for these compounds using the coulometric and EPA methods. C1 IOWA STATE UNIV,DEPT CHEM,AMES,IA 50011. IOWA STATE UNIV,AMES LAB,AMES,IA 50011. ABILENE CHRISTIAN UNIV,DEPT CHEM,ABILENE,TX 79699. NR 30 TC 13 Z9 13 U1 2 U2 11 PU WILEY-V C H VERLAG GMBH PI WEINHEIM PA POSTFACH 10 11 61, D-69451 WEINHEIM, GERMANY SN 1040-0397 J9 ELECTROANAL JI Electroanalysis PD MAR PY 1997 VL 9 IS 4 BP 279 EP 283 DI 10.1002/elan.1140090403 PG 5 WC Chemistry, Analytical; Electrochemistry SC Chemistry; Electrochemistry GA WY092 UT WOS:A1997WY09200002 ER PT J AU Bates, J AF Bates, J TI Thin-film rechargeable lithium batteries SO ELECTRONIC ENGINEERING LA English DT Article RP Bates, J (reprint author), OAK RIDGE NATL LAB,OAK RIDGE,TN 37831, USA. NR 3 TC 8 Z9 8 U1 0 U2 4 PU MILLER FREEMAN TECHNICAL LTD PI LONDON PA 30 CALDERWOOD ST, LONDON, ENGLAND SE18 6QH SN 0013-4902 J9 ELECTRON ENG JI Electron. Eng. PD MAR PY 1997 VL 69 IS 843 BP 63 EP 64 PG 2 WC Engineering, Electrical & Electronic SC Engineering GA XH162 UT WOS:A1997XH16200026 ER PT J AU Giometti, CS Williams, K Tollaksen, SL AF Giometti, CS Williams, K Tollaksen, SL TI A two-dimensional electrophoresis database of human breast epithelial cell proteins SO ELECTROPHORESIS LA English DT Article; Proceedings Paper CT 2nd Siena 2D Electrophoresis - From Genome to Proteome CY SEP 16-18, 1996 CL SIENA, ITALY DE two-dimensional polyacrylamide gel electrophoresis; proteins; breast, human ID POLYACRYLAMIDE-GEL ELECTROPHORESIS; 2-DIMENSIONAL ELECTROPHORESIS; GENE-EXPRESSION; TISSUE PROTEINS; QUANTITATION; FRACTIONS; PATTERNS; SERUM AB As sequencing of the human genome progresses, attention is turning to when and where specific genes are being expressed and how that expression is regulated. The human breast, with the highly specific, but transient, function of milk production (lactation), exemplifies human gene regulation. The molecular mechanisms for the dramatic structural and functional changes involved in shifting from lactation-capable to lactation-incapable tissue are poorly understood, as are the mechanisms that result in deviation from normal breast cell growth into different types of breast neoplasms. We are using quantitative two-dimensional electrophoresis (2-DE) to determine which proteins are present in different types of human breast cells (milk-producing and -nonproducing, estrogen-receptor-positive and -negative, normal and malignant) and which proteins change in abundance in response to stimuli that trigger cell differentiation, growth, or death. A composite map of proteins found in human breast cells is being generated and used as an index of human genes that are differentially expressed, both qualitatively and quantitatively. Proteins found in 15 different types of human breast cells, two from healthy tissue (from milk and reduction mammoplasty tissue) and 13 from tumor tissue, are now included in the composite map. Copies of the human breast epithelial cell protein map are available on the World Wide Web (URL: http://www.anl.gov/CMB/PMG/projects/index hbreast, html) with links to quantitative data and identifications for proteins found to be differentially expressed in these epithelial cells. Links to the Swiss-Prot and enzyme metabolic pathway databases are also provided. The World Wide Web presentation is designed to allow public access to the available 2-DE data together with logical connections to databases providing genome-related information. RP Giometti, CS (reprint author), ARGONNE NATL LAB,CTR MECHANIST BIOL & BIOTECHNOL,9700 S CASS AVE,BLDG 202,ROOM B117,ARGONNE,IL 60439, USA. NR 22 TC 40 Z9 40 U1 0 U2 1 PU VCH PUBLISHERS INC PI DEERFIELD BEACH PA 303 NW 12TH AVE, DEERFIELD BEACH, FL 33442-1788 SN 0173-0835 J9 ELECTROPHORESIS JI Electrophoresis PD MAR-APR PY 1997 VL 18 IS 3-4 BP 573 EP 581 DI 10.1002/elps.1150180340 PG 9 WC Biochemical Research Methods; Chemistry, Analytical SC Biochemistry & Molecular Biology; Chemistry GA WW358 UT WOS:A1997WW35800039 PM 9150944 ER PT J AU Kuhr, JH Robertson, JD Lafferty, CJ Wong, AS Stalnaker, ND AF Kuhr, JH Robertson, JD Lafferty, CJ Wong, AS Stalnaker, ND TI Ion exchange properties of a Western Kentucky low-rank coal SO ENERGY & FUELS LA English DT Article; Proceedings Paper CT Symposium on Production and Use of Carbon-Based Materials for Environmental Change at 211th ACS National Meeting CY MAR 24-28, 1996 CL NEW ORLEANS, LA SP Amer Chem Soc (ACS), Amer Chem Soc, Div Fuel Chem ID BROWN-COAL; ADSORPTION AB The ion exchange properties of a low-rank coal were evaluated to explore its viability as an inexpensive material for removing radionuclides and heavy metals from solution. Cobalt was used as a model metal to investigate the kinetics and thermodynamics of the exchange process and the effect that solution pH has on the exchange capacity. Maximum metal adsorption was found to occur at pH greater than or equal to 3.5. The exchange was found to follow first-order kinetics and to proceed rapidly; over the temperature range investigated (-15 to 50 degrees C) equilibrium was reached within 10-20 min. The exchange was well described by the Langmuir adsorption isotherm with a Gibbs free energy of -8.85+/-0.24 kJ/mol. Additional studies with environmentally significant metals and radionuclides demonstrated that cations with higher charge density were preferentially adsorbed. C1 UNIV KENTUCKY,DEPT CHEM,LEXINGTON,KY 40506. UNIV KENTUCKY,CTR APPL ENERGY RES,LEXINGTON,KY 40511. LOS ALAMOS NATL LAB,CST8,MS G740,LOS ALAMOS,NM 87545. NR 18 TC 9 Z9 9 U1 0 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0887-0624 J9 ENERG FUEL JI Energy Fuels PD MAR-APR PY 1997 VL 11 IS 2 BP 323 EP 326 DI 10.1021/ef960146c PG 4 WC Energy & Fuels; Engineering, Chemical SC Energy & Fuels; Engineering GA WP332 UT WOS:A1997WP33200013 ER PT J AU Farmer, JC Bahowick, SM Harrar, JE Fix, DV Martinelli, RE Vu, AK Carroll, KL AF Farmer, JC Bahowick, SM Harrar, JE Fix, DV Martinelli, RE Vu, AK Carroll, KL TI Electrosorption of chromium ions on carbon aerogel electrodes as a means of remediating ground water SO ENERGY & FUELS LA English DT Article; Proceedings Paper CT Symposium on Production and Use of Carbon-Based Materials for Environmental Change at 211th ACS National Meeting CY MAR 24-28, 1996 CL NEW ORLEANS, LA SP Amer Chem Soc (ACS), Amer Chem Soc, Div Fuel Chem ID FLOW-THROUGH; REMOVAL; SILVER; COPPER; MODEL AB An electrically regenerated separation process has been developed for removing unwanted ions from aqueous waste streams as a minimally polluting, energy-efficient, and potentially cost-effective alternative to ion exchange, reverse osmosis, electrodialysis, and evaporation. Ground water containing various anions and cations is passed through a stack of carbon aerogel electrodes, each having a very high specific surface area (400-1100 m(2) g(-1)) and exceptionally low electrical resistivity (less than or equal to 40 m Omega . cm). After polarization of the stack, impurity ions are removed from the electrolyte by the imposed electric field and adsorbed on the electrode surfaces. Field tests have shown that hexavalent chromium in the form of HCrO4-/CrO42-/Cr2O72- can be selectively removed from contaminated ground water with a 530 ppm total dissolved solids (TDS) background. The concentration of Cr(VI) can be lowered from 35 to 2 ppb, well below the acceptable level for the regulatory surface water discharge limit of 11 ppb. The mechanism for Cr(VI) separation involves chemisorption on the carbon aerogel anode, a process that can be reversed by cathodic polarization. Cr(VI) removal is not based upon simple double-layer charging. RP Farmer, JC (reprint author), LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94551, USA. NR 53 TC 82 Z9 86 U1 5 U2 27 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0887-0624 J9 ENERG FUEL JI Energy Fuels PD MAR-APR PY 1997 VL 11 IS 2 BP 337 EP 347 DI 10.1021/ef9601374 PG 11 WC Energy & Fuels; Engineering, Chemical SC Energy & Fuels; Engineering GA WP332 UT WOS:A1997WP33200016 ER PT J AU Gao, YM Shim, HS Hurt, RH Suuberg, EM AF Gao, YM Shim, HS Hurt, RH Suuberg, EM TI Effects of carbon on air entrainment in fly ash concrete: The role of soot and carbon black SO ENERGY & FUELS LA English DT Article AB The most important commercial outlet for coal ash is in the concrete industry as a partial replacement for Portland cement. In many concrete mixtures careful control of air entrainment is required, but the presence of solid carbon disrupts the air entrainment process. An earlier study focused on the fundamental role of carbons, which were found to adsorb air-entraining admixtures, the specialty surfactants used in concrete mixtures, rendering them less active for their primary function as stabilizing agents for air bubbles. The present paper focuses on the specific sorptive behavior of carbon black, which is used as a pigment in some concrete formulations and also serves as a convenient model substance for soot, which may be present in fly ash from coal combustion. The paper also describes microscopic examination of several commercial fly ash samples for the possible presence of soot. The results show that eight commercial carbon blacks interact strongly with the air-entraining admixtures, the degree of interaction increasing with decreasing primary particle size or increasing nitrogen surface area. Overall, the adsorption of air-entraining admixtures is believed to be governed by the amount of accessible, hydrophobic, carbonaceous surface area. Examination of three fly ash samples from commercial pulverized coal fired combustion systems resulted in the conclusive identification of at least trace amounts of soot in each sample, with significant amounts found in one sample intentionally generated under very poor combustion conditions, Finally, a simple laboratory test was developed to screen ash samples for the presence of significant quantities of fine carbonaceous particles, which, on the basis of the results of this study, can have a negative impact on concrete performance in certain special cases. C1 BROWN UNIV,DIV ENGN,PROVIDENCE,RI 02912. SANDIA NATL LABS,LIVERMORE,CA 94550. NR 10 TC 39 Z9 41 U1 0 U2 6 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0887-0624 J9 ENERG FUEL JI Energy Fuels PD MAR-APR PY 1997 VL 11 IS 2 BP 457 EP 462 DI 10.1021/ef960113x PG 6 WC Energy & Fuels; Engineering, Chemical SC Energy & Fuels; Engineering GA WP332 UT WOS:A1997WP33200033 ER PT J AU Solum, MS Pugmire, RJ Grant, DM Kelemen, SR Gorbaty, ML Wind, RA AF Solum, MS Pugmire, RJ Grant, DM Kelemen, SR Gorbaty, ML Wind, RA TI N-15 CPMAS NMR of the argonne premium coals SO ENERGY & FUELS LA English DT Article ID MODEL ORGANIC-COMPOUNDS; DYNAMIC NUCLEAR-POLARIZATION; MAGIC-ANGLE; CROSS POLARIZATION; C-13 NMR; NITROGEN; SPECTRA; SPECTROSCOPY; PYROLYSIS; RESONANCE AB N-15 NMR data are reported for the Argonne Premium Coals. Arguments are presented to explain discrepancies between observations and conclusions obtained from NMR experiments and those obtained by XPS and XANES techniques. Detectability of different types of nitrogens is discussed in terms of cross-polarization dynamics together with the effects of the large chemical shift anisotropy that is found in different types of nitrogen functional groups. Data on acid-treated coals confirm the presence of pyridinic type nitrogens that were not observed in a previous N-15 NMR study of coals. C1 UNIV UTAH, DEPT CHEM, SALT LAKE CITY, UT 84112 USA. EXXON RES & ENGN CO, ANNANDALE, NJ 08801 USA. PACIFIC NW LAB, ENVIRONM & MOL SCI LAB, RICHLAND, WA 99357 USA. RP Solum, MS (reprint author), UNIV UTAH, DEPT CHEM & FUELS ENGN, SALT LAKE CITY, UT 84112 USA. NR 26 TC 27 Z9 33 U1 4 U2 9 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0887-0624 J9 ENERG FUEL JI Energy Fuels PD MAR-APR PY 1997 VL 11 IS 2 BP 491 EP 494 DI 10.1021/ef960169r PG 4 WC Energy & Fuels; Engineering, Chemical SC Energy & Fuels; Engineering GA WP332 UT WOS:A1997WP33200038 ER PT J AU Cody, GD Obeng, M Thiyagarajan, P AF Cody, GD Obeng, M Thiyagarajan, P TI Characterization of the soluble and insoluble fractions of upper freeport coal in NMP/CS2 and pyridine using small angle neutron scattering SO ENERGY & FUELS LA English DT Article ID X-RAY-SCATTERING; CS2-N-METHYL-2-PYRROLIDINONE MIXED-SOLVENT; MACROSTRUCTURE; TEMPERATURE; ASPHALTENES; EXTRACTION; SURFACES; ROUGH AB Small angle neutron scattering (SANS) was used to characterize the solution structure of coal extract/solvent systems as well as swelling-induced structural changes in the nonextractable residues derived from the Upper Freeport (UF), medium-volatile bituminous, coal. Studies were performed on the pyridine soluble (PyS) fraction dispersed in perdeuterated pyridine (dPy); the PyS fraction dispersed in the mixed solvent [dm, perdeuterated N-methylpyrrolidinone (NMP) and carbon disulfide, CS2], and the mixed solvent soluble fraction (MS) in dM. No coherent scattering was observed for the UF-MS/dM sample in the accessible Q range, indicating that the solution contains no large particles or aggregates. Strong coherent scattering was observed for the UF-PyS/dPy and UF-PyS/dM solutions, indicating the presence of large particles, presumably molecular aggregates. Comparison of the SANS behavior of the three samples suggests that there exist molecular components intrinsic to the pyridine insoluble NMP/CS2 soluble fraction that may play a significant role in the enhanced solvation of the mixed soluble fraction of the Upper Freeport coal in NMP/CS2 solvent. SANS analysis of the dry and pyridine (d(5))-swollen UF-PyI and UF-MI residues revealed significant structure evident by power-law scattering behavior in the low Q region of both sets of samples. In the case of the UF-MI samples, significant scattering intensity was also observed in the intermediate Q region. Significant structural changes were observed in the UF-MI fractions upon swelling in pyridine, whereas minimal structural changes were observed in the case of UF-PyI sample during solvent swelling. These results reveal that the physical consequences of mixed solvent extraction are significantly different from those due to pyridine extraction. C1 ARGONNE NATL LAB,DIV CHEM,ARGONNE,IL 60439. ARGONNE NATL LAB,INTENSE PULSED NEUTRON SOURCE,ARGONNE,IL 60439. RP Cody, GD (reprint author), CARNEGIE INST WASHINGTON,GEOPHYS LAB,5251 BROAD BRANCH RD NW,WASHINGTON,DC 20015, USA. NR 31 TC 12 Z9 12 U1 1 U2 3 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0887-0624 J9 ENERG FUEL JI Energy Fuels PD MAR-APR PY 1997 VL 11 IS 2 BP 495 EP 501 DI 10.1021/ef960182b PG 7 WC Energy & Fuels; Engineering, Chemical SC Energy & Fuels; Engineering GA WP332 UT WOS:A1997WP33200039 ER PT J AU Schrems, K Maclaren, D AF Schrems, K Maclaren, D TI Failure analysis of a mine hoist rope SO ENGINEERING FAILURE ANALYSIS LA English DT Article AB An extensive investigation was carried out to determine the cause of the early retirement of an inservice hoist rope. The rope was retired earlier than expected because it met the criteria for removal based on the number and distribution of wire breaks. Its chemistry, strength and ductility compared favorably to standards for new ropes. Metallography revealed minor anomalies, but these appeared indiscriminately in both the good and the bad segments, and in both broken and unbroken wires. Only one item appeared to be related to the failure of wires, and this was the appearance of a construction anomaly. This anomaly, termed a ''dive'', disrupts the construction of the strand, and may cause excessive crown wear or unusual wear patterns. The wire breaks removed from the rope were all found in the vicinity of dives. The investigation suggests that the dives are responsible for the premature retirement of the hoist rope. C1 HENDERSON MINE,EMPIRE,CO 80438. RP Schrems, K (reprint author), US DOE,ALBANY RES CTR,1450 QUEEN AVE SW,ALBANY,OR 97321, USA. NR 7 TC 7 Z9 7 U1 1 U2 5 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 1350-6307 J9 ENG FAIL ANAL JI Eng. Fail. Anal. PD MAR PY 1997 VL 4 IS 1 BP 25 EP 38 DI 10.1016/S1350-6307(96)00029-5 PG 14 WC Engineering, Mechanical; Materials Science, Characterization & Testing SC Engineering; Materials Science GA WT797 UT WOS:A1997WT79700002 ER PT J AU Biner, SB AF Biner, SB TI A numerical analysis of time dependent stress fields ahead of stationary interface cracks at creep regime .1. Interface cracks in bimaterials SO ENGINEERING FRACTURE MECHANICS LA English DT Article ID ASYMPTOTIC FIELDS; TIP; CAVITATION AB In this study, the behavior of stationary interface cracks at creep regime in plane-strain condition and pure crack opening dominated mode-I load state is investigated numerically. The bimaterials considered are elastic-creeping with power law and bimaterials having identical elastic properties but creeping at different rates. The results indicate that the amplitude of the crack tip singularity is dominated by the faster creeping sector. Neither the elastic properties (hence the initial elastic stress distribution) nor the creep properties of the slower creeping sector significantly affect the evolution of the C* value for the interface cracks under identical applied loading condition. At steady-state, the angular distribution of the stresses ahead of the interface cracks in the faster creeping sector resembles the HRR stress singularity that occurs ahead of the cracks in homogeneous materials at creep regime. However, the observed C* values for the interface cracks were about half of that seen for the crack in the homogeneous case under identical applied loading; and the occurrence of much larger radial, shear and hydrostatic stress components at significant distances ahead of the interface cracks was observed. On the other hand, the magnitudes of the normal stress component remained relatively the same for both crack types. Based on these observations, the possible growth rate of the interface cracks due to creep damage is also discussed. (C) 1997 Elsevier Science Ltd. All rights reserved. RP IOWA STATE UNIV, AMES LAB, AMES, IA 50011 USA. NR 31 TC 5 Z9 5 U1 1 U2 3 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0013-7944 EI 1873-7315 J9 ENG FRACT MECH JI Eng. Fract. Mech. PD MAR PY 1997 VL 56 IS 4 BP 513 EP 529 DI 10.1016/S0013-7944(96)00116-6 PG 17 WC Mechanics SC Mechanics GA WF704 UT WOS:A1997WF70400003 ER PT J AU Biner, SB AF Biner, SB TI A numerical analysis of time dependent stress fields ahead of stationary interface cracks at creep regime .2. Interface cracks in layered materials SO ENGINEERING FRACTURE MECHANICS LA English DT Article ID SILICON-CARBIDE; FRACTURE AB In this study, the behavior of stationary interface cracks in layered materials at creep regime in plane-strain condition and pure opening dominated mode-I load state was studied numerically. Cracks located at the interfaces of the transitional layer between the elastic and creeping sectors and cracks at the center of the transitional layer are considered. The role of the layer thickness on the evolution of the stress fields at creep regime is also elucidated. The results indicate that both the location of the interface crack and the extent of the transitional layer strongly influence the amplitude of the stress field (C*) at steady-state in layered materials. Also, the time required to achieve steady-state varies significantly with these parameters. The introduction of a transitional layer to the interface of the elastic-creeping bimaterials significantly elevates the stress values ahead of the interface cracks under identical applied load levels at creep regime. Due to large variation in the distribution of the stresses ahead of the crack tip, depending on which side of the transitional layer, the creep growth rates of such interface cracks will be significantly different from each other at creep regime under identical loading for a given layered material. (C) 1997 Elsevier Science Ltd. All rights reserved. RP Biner, SB (reprint author), IOWA STATE UNIV SCI & TECHNOL,AMES LAB,AMES,IA 50011, USA. NR 13 TC 4 Z9 4 U1 1 U2 3 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0013-7944 J9 ENG FRACT MECH JI Eng. Fract. Mech. PD MAR PY 1997 VL 56 IS 5 BP 657 EP & DI 10.1016/S0013-7944(96)00117-8 PG 17 WC Mechanics SC Mechanics GA WK647 UT WOS:A1997WK64700005 ER PT J AU Gilmore, TJ Clayton, EA AF Gilmore, TJ Clayton, EA TI Mapping the top of the permafrost using surface direct current resistivity survey SO ENVIRONMENTAL GEOLOGY LA English DT Article DE permafrost; resistivity; Alaska AB Data from a direct current resistivity survey and geologic logs from boreholes were used to map the top of permafrost at a remote air force installation in Alaska. This study resulted from a remedial investigation that was conducted at Eielson Air Force Base near Fairbanks, Alaska, under the federal Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) regulations. The depth and continuity of the permafrost was important in determining the fate of petroleum contamination that was inadvertently discharged to the ground during earlier air force operations. The results indicate that the top of permafrost forms a highly irregular surface. In general, however, the top of permafrost forms a diagonal ridge at the center of the contour grid that is bordered on each side by troughs. RP Gilmore, TJ (reprint author), PACIFIC NW LAB, POB 999, RICHLAND, WA 99352 USA. NR 7 TC 0 Z9 1 U1 0 U2 0 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 SN 0177-5146 J9 ENVIRON GEOL JI Environ. Geol. PD MAR PY 1997 VL 30 IS 1-2 BP 29 EP 33 PG 5 WC Environmental Sciences; Geosciences, Multidisciplinary; Water Resources SC Environmental Sciences & Ecology; Geology; Water Resources GA WU695 UT WOS:A1997WU69500004 ER PT J AU Reed, MF Bartholomay, RC Hughes, SS AF Reed, MF Bartholomay, RC Hughes, SS TI Geochemistry and stratigraphic correlation of basalt lavas beneath the Idaho Chemical Processing Plant, Idaho National Engineering Laboratory SO ENVIRONMENTAL GEOLOGY LA English DT Article DE stratigraphy; basalt; geochemistry; Snake River Plain aquifer; Idaho National Engineering Laboratory AB Thirty-nine samples of basaltic core were collected from wells 121 and 123, located approximately 1.8 km apart north and south of the Idaho Chemical Processing Plant at the Idaho National Engineering Laboratory. Samples were collected from depths ranging from 15 to 221 m below land surface for the purpose of establishing stratigraphic correlations between these two wells. Elemental analyses indicate that the basalts consist of three principal chemical types. Two of these types are each represented by a single basalt flow in each well. The third chemical type is represented by many basalt flows and includes a broad range of chemical compositions that is distinguished from the other two types. Basalt flows within the third type were identified by hierarchical K-cluster analysis of 14 representative elements: Fe, Ca, K, Na, Sc, Co, La, Ce, Sm, Eu, Yb, Hf, Ta, and Th. Cluster analyses indicate correlations of basalt flows between wells 121 and 123 at depths of approximately 38-40 m, 125-128 m, 131-137 m, 149-158 m, and 183-198 m. Probable correlations also are indicated for at least seven other depth intervals. Basalt flows in several depth intervals do not correlate on the basis of chemical compositions, thus reflecting possible flow margins in the sequence between the wells. Multi-element chemical data provide a useful method for determining stratigraphic correlations of basalt in the upper 1-2 km of the eastern Snake River Plain. C1 IDAHO STATE UNIV,DEPT GEOL,POCATELLO,ID 83209. US GEOL SURVEY,DIV WATER RESOURCES,INEL,IDAHO FALLS,ID 83403. NR 13 TC 11 Z9 11 U1 0 U2 2 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 SN 0177-5146 J9 ENVIRON GEOL JI Environ. Geol. PD MAR PY 1997 VL 30 IS 1-2 BP 108 EP 118 PG 11 WC Environmental Sciences; Geosciences, Multidisciplinary; Water Resources SC Environmental Sciences & Ecology; Geology; Water Resources GA WU695 UT WOS:A1997WU69500013 ER PT J AU Gibbons, JW Burke, VJ Lovich, JE Semlitsch, RD Tuberville, TD Bodie, JR Greene, JL Niewiarowski, PH Whiteman, HH Scott, DE Pechmann, JHK Harrison, CR Bennett, SH Krenz, JD Mills, MS Buhlmann, KA Lee, JR Seigel, RA Tucker, AD Mills, TM Lamb, T Dorcas, ME Congdon, JD Smith, MH Nelson, DH Dietsch, MB Hanlin, HG Ott, JA Karapatakis, DJ AF Gibbons, JW Burke, VJ Lovich, JE Semlitsch, RD Tuberville, TD Bodie, JR Greene, JL Niewiarowski, PH Whiteman, HH Scott, DE Pechmann, JHK Harrison, CR Bennett, SH Krenz, JD Mills, MS Buhlmann, KA Lee, JR Seigel, RA Tucker, AD Mills, TM Lamb, T Dorcas, ME Congdon, JD Smith, MH Nelson, DH Dietsch, MB Hanlin, HG Ott, JA Karapatakis, DJ TI Perceptions of species abundance, distribution, and diversity: Lessons from four decades of sampling on a government-managed reserve SO ENVIRONMENTAL MANAGEMENT LA English DT Article DE abundance; amphibian; biodiversity; distribution; land management; reptile ID SOUTH-CAROLINA; POPULATIONS; DEMOGRAPHY AB We examined data relative to species abundance, distribution, and diversity patterns of reptiles and amphibians to determine how perceptions change over time and with level of sampling effort. Location data were complied on more than one million individual captures or observations of 98 species during a 44-year study period on the US Department of Energy's (DOE) Savannah River Site National Environmental Research Park (SRS-NERP) in South Carolina. We suggest that perceptions of herpetofaunal species diversity are strongly dependent on level of effort and that land management decisions based on short-term data bases for some faunal groups could result in serious errors in environmental management. We provide evidence that acquiring information on biodiversity distribution patterns is compatible with multiyear spatially extensive research programs and also provide a perspective of what might be achieved if long-term, coordinated research efforts were instituted nationwide. To conduct biotic surveys on government-managed lands, we recommend revisions in the methods used by government agencies to acquire and report biodiversity data. We suggest that government and industry employees engaged in biodiversity survey efforts develop proficiency in field identification for one or more major taxonomic groups and be encouraged to measure the status of populations quantitatively with consistent and reliable methodologies. We also suggest that widespread academic cooperation in the dissemination of information on regional patterns of biodiversity could result by establishment of a peer-reviewed, scientifically rigorous journal concerned with status and trends of the biota of the United States. C1 NATL BIOL SERV, PALM SPRINGS, CA 92258 USA. UNIV MISSOURI, COLUMBIA, MO 65211 USA. TEXAS A&M UNIV, COLLEGE STN, TX 77843 USA. S CAROLINA DEPT NAT RESOURCES, HERITAGE TRUST PROGRAM, COLUMBIA, SC 29202 USA. SE LOUISIANA UNIV, DEPT BIOL, HAMMOND, LA 70402 USA. UNIV QUEENSLAND, DEPT ZOOL, BRISBANE, QLD, AUSTRALIA. E CAROLINA UNIV, DEPT BIOL, GREENVILLE, NC 27858 USA. IDAHO STATE UNIV, POCATELLO, ID 83209 USA. UNIV S ALABAMA, DEPT BIOL, MOBILE, AL 35487 USA. UNIV S CAROLINA, DEPT BIOL, AIKEN, SC 29801 USA. RP Gibbons, JW (reprint author), UNIV GEORGIA, SAVANNAH RIVER ECOL LAB, DRAWER E, AIKEN, SC 29802 USA. RI Dietsch, Barbara/E-9466-2017; OI Lovich, Jeffrey/0000-0002-7789-2831; Semlitsch, Raymond/0000-0002-7999-5762 NR 62 TC 50 Z9 54 U1 6 U2 26 PU SPRINGER PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 0364-152X EI 1432-1009 J9 ENVIRON MANAGE JI Environ. Manage. PD MAR-APR PY 1997 VL 21 IS 2 BP 259 EP 268 DI 10.1007/s002679900025 PG 10 WC Environmental Sciences SC Environmental Sciences & Ecology GA WH932 UT WOS:A1997WH93200013 ER PT J AU Jin, Y Yu, QQ Chang, SG AF Jin, Y Yu, QQ Chang, SG TI Reduction of sulfur dioxide by syngas to elemental sulfur over iron-based mixed oxide supported catalyst SO ENVIRONMENTAL PROGRESS LA English DT Article ID CARBON-MONOXIDE; ALUMINA; METHANE AB An iron-based supported catalyst has been developed for the reduction of SO2 by synthesis gas to obtain more than 97% yield of elemental sulfur with a single stage reactor for 340-480 degrees C (30-40 mesh particles), 440-580 degrees C (d . 3 mm x h . 5 mm granules). Parametric studies on the performance of the catalyst have been conducted. The parameters studied include temperature, space velocity, molar ratio of H-2 to CO, molar ratio of syngas to SO2 in the feed, and particle size of the catalyst. A lifetime test has been successfully performed. The mass balance of sulfur and carbon has been demonstrated. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY NATL LAB,DIV ENERGY & ENVIRONM,BERKELEY,CA 94720. NR 21 TC 13 Z9 14 U1 2 U2 2 PU AMER INST CHEMICAL ENGINEERS PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 SN 0278-4491 J9 ENVIRON PROG JI Environ. Prog. PD SPR PY 1997 VL 16 IS 1 BP 1 EP 8 DI 10.1002/ep.3300160112 PG 8 WC Engineering, Environmental; Engineering, Chemical; Environmental Sciences SC Engineering; Environmental Sciences & Ecology GA WM695 UT WOS:A1997WM69500003 ER PT J AU Chen, XB Wright, JV Conca, JL Peurrung, LM AF Chen, XB Wright, JV Conca, JL Peurrung, LM TI Effects of pH on heavy metal sorption on mineral apatite SO ENVIRONMENTAL SCIENCE & TECHNOLOGY LA English DT Article ID INORGANIC CATION-EXCHANGERS; SYNTHETIC HYDROXYAPATITES; LEAD IMMOBILIZATION; AQUEOUS-SOLUTIONS; PHOSPHATE ROCKS; CALCIUM HYDROXYAPATITE; SOLUBILITY PRODUCT; SOIL-PH; ADSORPTION; IONS AB The sorption of aqueous Pb, Cd, and Zn onto a mineral apatite from North Carolina was investigated in relation to a wide range of pH. The effects of pH on solid-phase precipitation were particularly emphasized. The heavy metals were applied as single or multiple species. Solution pH greatly affected metal sorption mechanism by apatite and metal-apatite reaction products. The sorption of aqueous Pb was primarily through a process of the dissolution of apatite followed by the precipitation of variable pyromorphite-type minerals under acidic condition or of hydrocerussite [Pb-3(CO3)(2)(OH)(2)] and lead oxide fluoride (Pb2OF2) under alkaline condition. Otavite (CdCO3), cadmium hydroxide [Cd(OH)(2)], and zincite (ZnO) were formed in the Cd or Zn system, especially under alkaline condition; while hopeite [Zn-3(PO4)(2) . 4H(2)O] might precipitate only under very acidic condition. Alternative sorption mechanisms other than precipitation of the crystalline phases were important in reducing Cd and Zn concentrations by the apatite and might include ion exchange, adsorption, absorption, complexation, coprecipitation, or precipitation of amorphous phases. Removal of Cd and Zn by the apatite was pH dependent, whereas removal of Pb was not. The removals were about 0.729 mmol of Pb, 0.489-1.317 mmol of Cd, and 0.596-2.187 mmol of Zn/g of apatite, representing removal of 99.9%, 37.0-99.9%, and 27.0-99.9% of heavy metals from solution, respectively. C1 UFA VENTURES, RICHLAND, WA 99352 USA. RP Chen, XB (reprint author), PACIFIC NW LAB, POB 999,BATTELLE BLVD, RICHLAND, WA 99352 USA. NR 50 TC 240 Z9 261 U1 16 U2 128 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0013-936X J9 ENVIRON SCI TECHNOL JI Environ. Sci. Technol. PD MAR PY 1997 VL 31 IS 3 BP 624 EP 631 PG 8 WC Engineering, Environmental; Environmental Sciences SC Engineering; Environmental Sciences & Ecology GA WK815 UT WOS:A1997WK81500028 ER PT J AU Ma, CY Skeen, JT Dindal, AB Bayne, CK Jenkins, RA AF Ma, CY Skeen, JT Dindal, AB Bayne, CK Jenkins, RA TI Performance evaluation of a thermal desorption gas chromatographic mass spectrometric method for the characterization of waste tank headspace samples SO ENVIRONMENTAL SCIENCE & TECHNOLOGY LA English DT Article ID VOLATILE ORGANIC-COMPOUNDS; HANFORD; WATER; AIR AB A thermal desorption/gas chromatography/mass spectrometry (TD/GC/MS) method was validated for the determination of volatile organic compounds collected on carbonaceous triple sorbent traps and applied to characterize samples of headspace gases collected from underground nuclear waste storage tanks at the U.S. Department of Energy's Hanford site, in Richland, WA. Method validation used vapor-phase standards generated from 25 target analytes, including alkanes, alkyl alcohols, alkyl ketones, alkylated aromatics, and alkyl nitriles. The target analytes represent a group of compounds identified in one of the most problematic tanks. TD/GC/MS was carried out with Hewlett-Packard 5972A or 5995 GC/MS systems with modified injectors. Performance was characterized based on desorption efficiency, reproducibility, stability, and linearity of the calibration, method detection limits, preanalytical holding time, and quality control limits for surrogate standard recoveries. Desorption efficiencies were. all greater than 82%, and the majority of the analytes (23 out of 25) had reproducibility values less than 24% near the method detection levels, The method was applied to the analysis of a total of 305 samples collected from the headspaces of 48 underground waste storage tanks. Duality control procedures were implemented to monitor sampling and TD/GC/MS method. C1 OAK RIDGE NATL LAB,DIV MATH & COMP SCI,OAK RIDGE,TN 37831. RP Ma, CY (reprint author), OAK RIDGE NATL LAB,DIV CHEM & ANALYT SCI,OAK RIDGE,TN 37831, USA. NR 32 TC 15 Z9 15 U1 2 U2 3 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0013-936X J9 ENVIRON SCI TECHNOL JI Environ. Sci. Technol. PD MAR PY 1997 VL 31 IS 3 BP 853 EP 859 DI 10.1021/es9605174 PG 7 WC Engineering, Environmental; Environmental Sciences SC Engineering; Environmental Sciences & Ecology GA WK815 UT WOS:A1997WK81500062 ER PT J AU Cronkite, EP AF Cronkite, EP TI Mobilization of peripheral blood 'stem' cells: Where there is smoke, is there fire? Yes, there have been many fires, leaving cold coals - Response SO EXPERIMENTAL HEMATOLOGY LA English DT Letter ID TRANSFUSION; DOGS RP Cronkite, EP (reprint author), BROOKHAVEN NATL LAB,DEPT MED,UPTON,NY 11973, USA. NR 19 TC 2 Z9 2 U1 0 U2 0 PU CARDEN JENNINGS PUBL CO LTD PI CHARLOTTESVILLE PA BLAKE CTR, STE 200, 1224 W MAIN ST, CHARLOTTESVILLE, VA 22903 SN 0301-472X J9 EXP HEMATOL JI Exp. Hematol. PD MAR PY 1997 VL 25 IS 3 BP 185 EP 186 PG 2 WC Hematology; Medicine, Research & Experimental SC Hematology; Research & Experimental Medicine GA WP336 UT WOS:A1997WP33600001 PM 9091291 ER PT J AU Coutant, CC AF Coutant, CC TI An interface: Council of Aquatic Sciences SO FISHERIES LA English DT Editorial Material RP Coutant, CC (reprint author), OAK RIDGE NATL LAB,DIV ENVIRONM SCI,POB 2008,MAIL STOP 6036,BLDG 1505,ROOM 250,OAK RIDGE,TN 37831, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER FISHERIES SOC PI BETHESDA PA 5410 GROSVENOR LANE SUITE 110, BETHESDA, MD 20814-2199 SN 0363-2415 J9 FISHERIES JI Fisheries PD MAR PY 1997 VL 22 IS 3 BP 33 EP 33 PG 1 WC Fisheries SC Fisheries GA WL268 UT WOS:A1997WL26800008 ER PT J AU Brannan, CJ Curtis, CW Cronauer, DC AF Brannan, CJ Curtis, CW Cronauer, DC TI Interactions of swelling solvents and catalyst precursors in coal liquefaction systems SO FUEL PROCESSING TECHNOLOGY LA English DT Article DE coal liquefaction; coal swelling; slurry phase catalysts; catalyst impregnation ID LOW-RANK COALS; BEHAVIOR AB A study was undertaken to evaluate the effect of process parameters on the liquefaction of swelled Black Thunder mine (WY) subbituminous coal with the introduction of soluble catalyst precursors. The process concept involved simultaneously swelling coal with a hydrogen bonding solvent and impregnating coal with a soluble catalyst precursor with subsequent liquefaction at 410 degrees C in a hydrogen atmosphere. The parameters included reaction solvent, swelling solvent and its interaction with various catalyst precursors, and the type, loading, and method of introduction of the catalysts. Interactions among the parameters were evident. Of particular significance, the swelling solvent and its interaction with the catalyst precursor affected coal conversion. Adjusting the various parameters did not increase coal conversion relative to the conversion achieved when the catalyst precursors were added directly to the liquefaction feed slurry. (C) 1997 Elsevier Science B.V. C1 AUBURN UNIV,DEPT CHEM ENGN,AUBURN,AL 36849. ARGONNE NATL LAB,ARGONNE,IL 60439. NR 26 TC 7 Z9 7 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0378-3820 J9 FUEL PROCESS TECHNOL JI Fuel Process. Technol. PD MAR PY 1997 VL 51 IS 1-2 BP 63 EP 81 DI 10.1016/S0378-3820(96)01069-7 PG 19 WC Chemistry, Applied; Energy & Fuels; Engineering, Chemical SC Chemistry; Energy & Fuels; Engineering GA XC638 UT WOS:A1997XC63800005 ER PT J AU Young, KM AF Young, KM TI Advanced tokamak diagnostics SO FUSION ENGINEERING AND DESIGN LA English DT Article; Proceedings Paper CT 7th International Toki Conference on Plasma Physics and Controlled Nuclear Fusion Research (ITC-7) CY NOV 29-DEC 02, 1995 CL TOKI CITY, JAPAN SP Gifu Prefecture, Toki City, Japan Soc Plasma Phys & Nucl Fus Res, Fus Sci Org, Minist Educ, Japan ID THOMSON SCATTERING; DIII-D; TFTR; PLASMA AB Experiments on the current generation of large tokamaks have demonstrated that the core confinement properties are sufficiently good that the tokamak program can move forward to studies of long-pulse tokamaks with reactor-like properties in the core. On-going experiments show the benefits of plasma shaping and the capabilities of divertor design. Very good confinement has been obtained in magnetic field configurations which have been created with a region with reversed magnetic shear inside the plasma, and these results encourage further experiments in present devices extending the pulse length and improving the plasma performance, and moving forward to another generation of tokamaks. The significant challenges in plasma measurement are being addressed in the design work in progress for the international tokamak experimental reactor (ITER), and were being studied for the tokamak physics experiment (TPX). There will have to be extensive capabilities for using diagnostic signals in the control of the magnetic fields, heating and current drive sources, and fuelling. Clearly, many of the properties of the plasma in the diverters must be measured to allow the control of the gas flows and of the first-wall temperatures. This paper will describe some aspects of preparing diagnostic systems for next-generation devices. (C) 1997 Elsevier Science S.A. RP Young, KM (reprint author), PRINCETON UNIV, PRINCETON PLASMA PHYS LAB, POB 451, PRINCETON, NJ 08543 USA. NR 26 TC 1 Z9 1 U1 0 U2 4 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0920-3796 J9 FUSION ENG DES JI Fusion Eng. Des. PD MAR PY 1997 VL 34-35 BP 3 EP 10 DI 10.1016/S0920-3796(96)00676-X PG 8 WC Nuclear Science & Technology SC Nuclear Science & Technology GA XL182 UT WOS:A1997XL18200003 ER PT J AU Darrow, DS Zweben, SJ Herrmann, HW AF Darrow, DS Zweben, SJ Herrmann, HW TI Alpha particle loss diagnostics in TFTR and tokamak reactors SO FUSION ENGINEERING AND DESIGN LA English DT Article; Proceedings Paper CT 7th International Toki Conference on Plasma Physics and Controlled Nuclear Fusion Research (ITC-7) CY NOV 29-DEC 02, 1995 CL TOKI CITY, JAPAN SP Gifu Prefecture, Toki City, Japan Soc Plasma Phys & Nucl Fus Res, Fus Sci Org, Minist Educ, Japan DE alpha particle losses; TFTR; tokamak ID FUSION PRODUCTS; COLLECTOR PROBE; SCINTILLATOR; DETECTORS AB Measurement of alpha particle loss rates to the first wall is of importance in planning tokamak fusion reactors, since large loss rates can adversely affect performance. A set of scintillator-based probes has been operated in TFTR to measure alpha particle losses during its DT campaign. A sample exposure probe has also provided alpha particle loss data under some conditions. These technologies, along with infrared imaging and Faraday cups, may be adaptable to alpha particle loss measurements in ITER or other reactor-scale tokamaks. Constraints on detector operation in a reactor environment are discussed. (C) 1997 Elsevier Science S.A. RP Darrow, DS (reprint author), PRINCETON UNIV, PLASMA PHYS LAB, POB 451, PRINCETON, NJ 08543 USA. NR 34 TC 8 Z9 8 U1 0 U2 3 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0920-3796 J9 FUSION ENG DES JI Fusion Eng. Des. PD MAR PY 1997 VL 34-35 BP 53 EP 58 DI 10.1016/S0920-3796(96)00690-4 PG 6 WC Nuclear Science & Technology SC Nuclear Science & Technology GA XL182 UT WOS:A1997XL18200009 ER PT J AU Takahashi, H AF Takahashi, H TI Interpretability of magnetic diagnostics in tokamaks - Search for a locked mode in the TFTR (tokamak) SO FUSION ENGINEERING AND DESIGN LA English DT Article; Proceedings Paper CT 7th International Toki Conference on Plasma Physics and Controlled Nuclear Fusion Research (ITC-7) CY NOV 29-DEC 02, 1995 CL TOKI CITY, JAPAN SP Gifu Prefecture, Toki City, Japan Soc Plasma Phys & Nucl Fus Res, Fus Sci Org, Minist Educ, Japan ID COMPASS-C TOKAMAK; JET AB The interpretability of magnetic diagnostics is discussed in the context of searching for a locked mode in a tokamak. Apparent external signatures of a locked-mode perturbation determined by a magnetic locked-mode diagnostic route are found under some circumstances to be at variance with the interior structure of the perturbation measured by an electron cyclotron emission diagnostic route. This discrepancy suggests the possibility that locked-mode detector signals may be misinterpreted under some conditions. It is conjectured that toroidally asymmetric 'halo' currents may be partly responsible for the locked-mode detector response and observed detrimental effects on the discharge. (C) 1997 Elsevier Science S.A. RP Takahashi, H (reprint author), PRINCETON UNIV, PRINCETON PLASMA PHYS LAB, POB 451, PRINCETON, NJ 08543 USA. NR 10 TC 5 Z9 5 U1 0 U2 0 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0920-3796 J9 FUSION ENG DES JI Fusion Eng. Des. PD MAR PY 1997 VL 34-35 BP 89 EP 95 DI 10.1016/S0920-3796(96)00670-9 PG 7 WC Nuclear Science & Technology SC Nuclear Science & Technology GA XL182 UT WOS:A1997XL18200014 ER PT J AU vanGoeler, S Bell, R Bernabei, S Davis, W Fishman, H Ignat, D Jones, S Kaita, R Petravich, G Roney, P Stevens, J AF vanGoeler, S Bell, R Bernabei, S Davis, W Fishman, H Ignat, D Jones, S Kaita, R Petravich, G Roney, P Stevens, J TI Measurement of electron energy distribution from X-ray diagnostics: Foil techniques used with the hard X-ray camera on PBX-M SO FUSION ENGINEERING AND DESIGN LA English DT Article; Proceedings Paper CT 7th International Toki Conference on Plasma Physics and Controlled Nuclear Fusion Research (ITC-7) CY NOV 29-DEC 02, 1995 CL TOKI CITY, JAPAN SP Gifu Prefecture, Toki City, Japan Soc Plasma Phys & Nucl Fus Res, Fus Sci Org, Minist Educ, Japan DE electron energy distribution; foil techniques; hard X-ray camera; PBX-M tokamak; lower hybrid current drive ID HYBRID CURRENT DRIVE; BREMSSTRAHLUNG EMISSION; STABILITY; TOKAMAK; PLT AB A half-screen foil technique was used with the hard X-ray camera on the PBX-M tokamak to determine the energy distribution of the suprathermal electrons generated during the lower hybrid current drive. The ratio of perpendicular to parallel temperature of the suprathermal electrons was deduced from anisotropy of the bremsstrahlung emission utilizing Abel inversion techniques. Results from lower hybrid current drive discharges are discussed. (C) 1997 Elsevier Science S.A. C1 MIT, CTR SPACE RES, CAMBRIDGE, MA 02139 USA. CRIP, BUDAPEST, HUNGARY. SANDIA NATL LABS, ALBUQUERQUE, NM 87185 USA. RP vanGoeler, S (reprint author), PRINCETON UNIV, PLASMA PHYS LAB, POB 451, PRINCETON, NJ 08543 USA. OI Davis, William/0000-0003-0666-7247 NR 16 TC 0 Z9 0 U1 0 U2 0 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0920-3796 J9 FUSION ENG DES JI Fusion Eng. Des. PD MAR PY 1997 VL 34-35 BP 97 EP 105 DI 10.1016/S0920-3796(96)00687-4 PG 9 WC Nuclear Science & Technology SC Nuclear Science & Technology GA XL182 UT WOS:A1997XL18200015 ER PT J AU Isler, RC AF Isler, RC TI Vacuum UV spectroscopy and impurity behavior in tokamak and stellarator plasmas SO FUSION ENGINEERING AND DESIGN LA English DT Article; Proceedings Paper CT 7th International Toki Conference on Plasma Physics and Controlled Nuclear Fusion Research (ITC-7) CY NOV 29-DEC 02, 1995 CL TOKI CITY, JAPAN SP Gifu Prefecture, Toki City, Japan Soc Plasma Phys & Nucl Fus Res, Fus Sci Org, Minist Educ, Japan ID TRANSPORT; ROTATION AB An overview of applications of vacuum UV (VUV) spectroscopy to studies of fusion plasmas is presented. This spectral region is usually considered to extend from 10 to 2000 Angstrom. Most impurity studies in core plasmas and in diverters rely on measuring the intensities of the bright resonance lines that lie in this wavelength range. In the core, these data are supplemented by emissions from charge exchange excitation to determine concentrations of fully stripped low-Z ions. Determinations of individual impurity radiative losses and densities are carried out with the aid of one-dimensional codes in which transport coefficients are adjusted until the modelled intensities are well matched to experimental observation. Analysis of divertor spectra presents special difficulties, because of the inherently two- or three-dimensional nature of the radiation patterns. In addition to impurity studies, VUV lines are used to determine electron and ion temperatures, and plasma rotation. (C) 1997 Elsevier Science S.A. RP Isler, RC (reprint author), OAK RIDGE NATL LAB, OAK RIDGE, TN 37831 USA. OI Isler, Ralph/0000-0002-5368-7200 NR 12 TC 5 Z9 6 U1 0 U2 0 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0920-3796 J9 FUSION ENG DES JI Fusion Eng. Des. PD MAR PY 1997 VL 34-35 BP 115 EP 123 DI 10.1016/S0920-3796(96)00686-2 PG 9 WC Nuclear Science & Technology SC Nuclear Science & Technology GA XL182 UT WOS:A1997XL18200017 ER PT J AU Rice, BW AF Rice, BW TI q profile measurements with the motional Stark effect diagnostic in the DIII-D tokamak SO FUSION ENGINEERING AND DESIGN LA English DT Article; Proceedings Paper CT 7th International Toki Conference on Plasma Physics and Controlled Nuclear Fusion Research (ITC-7) CY NOV 29-DEC 02, 1995 CL TOKI CITY, JAPAN SP Gifu Prefecture, Toki City, Japan Soc Plasma Phys & Nucl Fus Res, Fus Sci Org, Minist Educ, Japan ID POLARIMETRY AB The motional Stark effect (MSE) diagnostic has emerged as the most reliable technique for the measurement of q profiles in tokamaks equipped with neutral beams. In the DIII-D tokamak, two separate eight-channel MSE instruments are utilized, giving 16 radial measurements. The viewing geometry for each instrument is designed to optimize the radial resolution (1.5 cm < delta R < 6 cm) over the measurement range. Dual-frequency polarization modulators combined with lock-in detection provide a maximum signal-to-noise ratio with a time response of about 1 ms. Special consideration has gone into the design of the collection optics to minimize undesirable polarization effects on reflectors and Faraday roation in lenses. Examples of data from negative central magnetic shear, VH-mode and sawtoothing discharges highlight the capabilities of the DIII-D MSE diagnostic system. (C) 1997 Elsevier Science S.A. C1 LAWRENCE LIVERMORE NATL LAB, LIVERMORE, CA USA. NR 10 TC 17 Z9 18 U1 0 U2 1 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0920-3796 J9 FUSION ENG DES JI Fusion Eng. Des. PD MAR PY 1997 VL 34-35 BP 135 EP 142 DI 10.1016/S0920-3796(96)00684-9 PG 8 WC Nuclear Science & Technology SC Nuclear Science & Technology GA XL182 UT WOS:A1997XL18200019 ER PT J AU Wurden, GA AF Wurden, GA TI A radiation-hard, steady state, digital imaging bolometer system SO FUSION ENGINEERING AND DESIGN LA English DT Article; Proceedings Paper CT 7th International Toki Conference on Plasma Physics and Controlled Nuclear Fusion Research (ITC-7) CY NOV 29-DEC 02, 1995 CL TOKI CITY, JAPAN SP Gifu Prefecture, Toki City, Japan Soc Plasma Phys & Nucl Fus Res, Fus Sci Org, Minist Educ, Japan ID PLASMA AB The concept and design of a new type of bolometer system which can function with excellent spatial resolution and good time resolution in the next generation of long-pulse (or steady stale), harsh-neutron environment, fusion plasmas, is outlined. It uses a cooled pinhole-camera design, employing a robust, passive, segmented radiation absorber. In one scenario, IR emission from the absorber's front surface is relayed by metal mirror optics to a shielded, high resolution IR video camera with +/-0.01 degrees C temperature resolution. In a second scenario, the matrix is viewed from its back side, in order to eliminate any extraneous IR radiation from the vessel or plasma. The system can make thousands of simultaneous 'pixel' measurements at up to 50-60 Hz, with no wire leads through the vacuum interface. (C) 1997 Elsevier Science B.V. RP Wurden, GA (reprint author), LOS ALAMOS NATL LAB, POB 1663, LOS ALAMOS, NM 87545 USA. RI Wurden, Glen/A-1921-2017 OI Wurden, Glen/0000-0003-2991-1484 NR 9 TC 2 Z9 2 U1 0 U2 1 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0920-3796 J9 FUSION ENG DES JI Fusion Eng. Des. PD MAR PY 1997 VL 34-35 BP 301 EP 305 DI 10.1016/S0920-3796(96)00535-2 PG 5 WC Nuclear Science & Technology SC Nuclear Science & Technology GA XL182 UT WOS:A1997XL18200052 ER PT J AU Sasao, M Wurden, GA Mansfield, DK AF Sasao, M Wurden, GA Mansfield, DK TI Spectroscopic measurement of the Doppler broadening region of He II line emission of DT plasmas using impurity pellets SO FUSION ENGINEERING AND DESIGN LA English DT Article; Proceedings Paper CT 7th International Toki Conference on Plasma Physics and Controlled Nuclear Fusion Research (ITC-7) CY NOV 29-DEC 02, 1995 CL TOKI CITY, JAPAN SP Gifu Prefecture, Toki City, Japan Soc Plasma Phys & Nucl Fus Res, Fus Sci Org, Minist Educ, Japan AB The feasibility of spectroscopic measurement of the velocity distribution of alpha particle using the ablation cloud of a lithium or boron pellet was tested in the DT experiment of TFTR. The measurement was performed using a 10-channel narrow-band filtered spectrometer in the wavelength covering the 3.5 MeV alpha particle Doppler broadening region of the He II 468.6 nm line and its vicinity. The spectra from a lithium pellet consists of the continuum bremsstrahlung background, lithium line emissions and possibly a 468.6 nm helium line. However, no clear evidence of alpha particles was observed, even when boron pellets were injected. (C) 1997 Elsevier Science B.V. C1 LOS ALAMOS NATL LAB, LOS ALAMOS, NM 87545 USA. PRINCETON UNIV, PLASMA PHYS LAB, PRINCETON, NJ 08543 USA. RP Sasao, M (reprint author), NATL INST FUS SCI, CHIKUSA KU, NAGOYA, AICHI 46410, JAPAN. RI Wurden, Glen/A-1921-2017 OI Wurden, Glen/0000-0003-2991-1484 NR 4 TC 2 Z9 2 U1 0 U2 0 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0920-3796 J9 FUSION ENG DES JI Fusion Eng. Des. PD MAR PY 1997 VL 34-35 BP 333 EP 336 DI 10.1016/S0920-3796(96)00532-7 PG 4 WC Nuclear Science & Technology SC Nuclear Science & Technology GA XL182 UT WOS:A1997XL18200058 ER PT J AU Hillis, DL Klepper, CC VonHellermann, M Ehrenberg, J Finken, KH Mank, G AF Hillis, DL Klepper, CC VonHellermann, M Ehrenberg, J Finken, KH Mank, G TI Deuterium-tritium concentration measurements in the divertor of a tokamak via a modified Penning gauge SO FUSION ENGINEERING AND DESIGN LA English DT Article; Proceedings Paper CT 7th International Toki Conference on Plasma Physics and Controlled Nuclear Fusion Research (ITC-7) CY NOV 29-DEC 02, 1995 CL TOKI CITY, JAPAN SP Gifu Prefecture, Toki City, Japan Soc Plasma Phys & Nucl Fus Res, Fus Sci Org, Minist Educ, Japan AB The measurement oi the relative concentrations of hydrogen, deuterium, tritium and helium is an important task in the nuclear fusion research area. Control of the deuterium-tritium (D-T) isotropic ratio and limiting the helium ash content in a fusion plasma are the key to optimizing the fuel burn in a fusion reactor such as ITER. A diagnostic technique has been developed to measure the D-T isotopic ratio in the divertor of a tokamak with a Penning vacuum gauge. The Penning discharge provides a source of electrons to excite the neutral deuterium and tritium in the pumping duct. Subsequently, the visible light from the hydrogen isotopes is collected in an optical fibre bundle, transferred away from the tokamak into a low radiation background area and detected in a high resolution Czerny-Turner spectrometer, equipped with a fast CCD (charge-coupled device) camera for optical detection. The intensity of the observed line emission (D-alpha, 6561.03 Angstrom; T-alpha, 6560.44 Angstrom) is directly proportional to the partial pressure of each gas found in the divertor. The line intensity of each isotope is calibrated as a function of pressure. The ratio of the line intensities thus provides a direct measurement of the D-T isotopic ratio. The lower limit for the determination of the D-T isotopic ratio is about 0.5%. This system is applicable for the pressure range from 10(-5) mbar to a few times 10(-2) mbar. (C) 1997 Elsevier Science S.A. C1 JET JOINT UNDERTAKING, ABINGDON OX14 3EA, OXON, ENGLAND. FORSCHUNGSZENTRUM JULICH, FORSCHUNGSZENTRUM, EURATOM ASSOC, JULICH, GERMANY. RP Hillis, DL (reprint author), OAK RIDGE NATL LAB, OAK RIDGE, TN 37831 USA. NR 5 TC 18 Z9 18 U1 0 U2 4 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0920-3796 J9 FUSION ENG DES JI Fusion Eng. Des. PD MAR PY 1997 VL 34-35 BP 347 EP 351 DI 10.1016/S0920-3796(96)00653-9 PG 5 WC Nuclear Science & Technology SC Nuclear Science & Technology GA XL182 UT WOS:A1997XL18200061 ER PT J AU Janos, A Hastie, J McGuire, K Fredrickson, E Park, W AF Janos, A Hastie, J McGuire, K Fredrickson, E Park, W TI Bursts of electron cyclotron emission during disruptions of high beta discharges in TFTR SO FUSION ENGINEERING AND DESIGN LA English DT Article; Proceedings Paper CT 7th International Toki Conference on Plasma Physics and Controlled Nuclear Fusion Research (ITC-7) CY NOV 29-DEC 02, 1995 CL TOKI CITY, JAPAN SP Gifu Prefecture, Toki City, Japan Soc Plasma Phys & Nucl Fus Res, Fus Sci Org, Minist Educ, Japan AB During sudden disruptions of tokamak plasma discharges at high beta, short and intense bursts of electron cyclotron emission (ECE) are observed. A unique combination of two fast grating polychromator instruments located at different toroidal positions is used to measure the emission and characterize these bursts. New insights into the 3D dynamics of these disruptions and the accompanying bursts of ECE have been obtained. An explanation of the bursting is presented which is consistent both qualitatively and quantitatively with observations, predicting for example radiation enhancement factors of about 10. Bursting can be explained not in terms of enhanced excitation of emission but rather in terms of reduction of absorption of thermal emission. Bursting is consistent with a modification to the electron distribution function f(e) due to a rapid energy or particle exchange between hot electrons and cold electrons from the edge, momentarily reducing the velocity gradient of f(e) in the thermal region. Large ELM (edge-localized mode) events also exhibit bursts of ECE due to a similar sequence of events. (C) 1997 Elsevier Science S.A. RP Janos, A (reprint author), PRINCETON PLASMA PHYS LAB, POB 451, PRINCETON, NJ 08543 USA. NR 7 TC 0 Z9 0 U1 1 U2 1 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0920-3796 J9 FUSION ENG DES JI Fusion Eng. Des. PD MAR PY 1997 VL 34-35 BP 379 EP 382 DI 10.1016/S0920-3796(96)00650-3 PG 4 WC Nuclear Science & Technology SC Nuclear Science & Technology GA XL182 UT WOS:A1997XL18200067 ER PT J AU Zhuravlev, V Sanchez, J delaLuna, E Hirsch, M Estrada, T Branas, B Frances, M Geist, T Hartfuss, HJ Hanson, GR Wilgen, JB Kaita, R AF Zhuravlev, V Sanchez, J delaLuna, E Hirsch, M Estrada, T Branas, B Frances, M Geist, T Hartfuss, HJ Hanson, GR Wilgen, JB Kaita, R TI Amplitude modulation reflectometry for density profile measurements SO FUSION ENGINEERING AND DESIGN LA English DT Article; Proceedings Paper CT 7th International Toki Conference on Plasma Physics and Controlled Nuclear Fusion Research (ITC-7) CY NOV 29-DEC 02, 1995 CL TOKI CITY, JAPAN SP Gifu Prefecture, Toki City, Japan Soc Plasma Phys & Nucl Fus Res, Fus Sci Org, Minist Educ, Japan AB Amplitude modulation (AM) reflectometry is a technique for density profile measurements in magnetic fusion plasmas based on the measurement of the phase delay of the modulation in the amplitude of a microwave beam launched and reflected at the plasma. Results from AM experiments in the PBX-M tokamak and the W7-AS stellarator are presented. A general analysis of the capabilities of the technique is performed, particularly centered in the effects of spatial turbulence. Simulations of the effects of two-dimensional turbulence have been performed for medium size (W7-AS) and large devices (LHD stellarator, ITER), showing the capability of the AM technique to operate in turbulent plasmas. Finally, possible solutions to the problem of parasitic reflections in AM systems are presented as development options. (C) 1997 Elsevier Science S.A. C1 MAX PLANCK INST PLASMA PHYS, EURATOM ASSOC, D-85748 GARCHING, GERMANY. OAK RIDGE NATL LAB, OAK RIDGE, TN 37831 USA. PRINCETON PLASMA PHYS LAB, PRINCETON, NJ 08543 USA. RP Zhuravlev, V (reprint author), ASSOC EURATOM CIEMAT, MADRID 28040, SPAIN. RI Estrada, Teresa/N-9048-2016 OI Estrada, Teresa/0000-0001-6205-2656 NR 4 TC 2 Z9 2 U1 0 U2 0 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0920-3796 J9 FUSION ENG DES JI Fusion Eng. Des. PD MAR PY 1997 VL 34-35 BP 421 EP 424 DI 10.1016/S0920-3796(96)00605-9 PG 4 WC Nuclear Science & Technology SC Nuclear Science & Technology GA XL182 UT WOS:A1997XL18200076 ER PT J AU Nagayama, Y Fredrickson, ED Janos, AC McGuire, KM Taylor, G Yamada, M AF Nagayama, Y Fredrickson, ED Janos, AC McGuire, KM Taylor, G Yamada, M TI ECE image reconstruction for the investigation of MHD relaxation phenomena SO FUSION ENGINEERING AND DESIGN LA English DT Article; Proceedings Paper CT 7th International Toki Conference on Plasma Physics and Controlled Nuclear Fusion Research (ITC-7) CY NOV 29-DEC 02, 1995 CL TOKI CITY, JAPAN SP Gifu Prefecture, Toki City, Japan Soc Plasma Phys & Nucl Fus Res, Fus Sci Org, Minist Educ, Japan ID FUSION TEST REACTOR; BALLOONING MODES; PLASMAS AB High-resolution fast ECE image reconstruction has been used to investigate relaxation phenomena of the electron temperature profile, which is often caused after a pellet injection, on TFTR. Drift type modes are observed before the relaxation phenomena. A possible inference of this relaxation is the localized reconnection. (C) 1997 Elsevier Science S.A. C1 PRINCETON PLASMA PHYS LAB, PRINCETON, NJ 08543 USA. RP Nagayama, Y (reprint author), NATL INST FUS SCI, CHIKUSA KU, NAGOYA, AICHI 46401, JAPAN. RI Yamada, Masaaki/D-7824-2015 OI Yamada, Masaaki/0000-0003-4996-1649 NR 5 TC 0 Z9 0 U1 0 U2 0 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0920-3796 J9 FUSION ENG DES JI Fusion Eng. Des. PD MAR PY 1997 VL 34-35 BP 483 EP 486 DI 10.1016/S0920-3796(96)00598-4 PG 4 WC Nuclear Science & Technology SC Nuclear Science & Technology GA XL182 UT WOS:A1997XL18200090 ER PT J AU Nishitani, T Isobe, M Wurden, GA Chrien, RE Harano, H Tobita, K Kusama, Y AF Nishitani, T Isobe, M Wurden, GA Chrien, RE Harano, H Tobita, K Kusama, Y TI Triton burnup measurements using scintillating fiber detectors on JT-60U SO FUSION ENGINEERING AND DESIGN LA English DT Article; Proceedings Paper CT 7th International Toki Conference on Plasma Physics and Controlled Nuclear Fusion Research (ITC-7) CY NOV 29-DEC 02, 1995 CL TOKI CITY, JAPAN SP Gifu Prefecture, Toki City, Japan Soc Plasma Phys & Nucl Fus Res, Fus Sci Org, Minist Educ, Japan ID JET AB A new type of 14 MeV neutron detector, based on scintillating fibres, was developed for triton burnup measurements in JT-60U deuterium discharges. The detector consists of an array of scintillating fibres embedded in an aluminum matrix, coupled to a magnetic-resistant phototube with a high current output base, enabling count rates up to 100 MHz. The detector characteristics have been investigated using the Fusion Neutron Source (FNS) DT neutron generator. From the time-dependent measurement of 14 MeV neutron emission in neutral beam (NB) heated plasma discharges, the fast triton diffusivity has been evaluated to be 0.05-0.15 m(2) s(-1). Loss of fast tritons caused by Toroidal Alfven Eignmode (TAE) instability was observed in the peripheral region of the plasma. (C) 1997 Elsevier Science S.A. C1 NAGOYA UNIV, DEPT FUS SCI, NAGOYA, AICHI 46401, JAPAN. LOS ALAMOS NATL LAB, LOS ALAMOS, NM 87545 USA. UNIV TOKYO, BUNKYO KU, TOKYO 113, JAPAN. RP Nishitani, T (reprint author), JAPAN ATOM ENERGY RES INST, NAKA FUS RES ESTAB, NAKA, IBARAKI 31101, JAPAN. RI Wurden, Glen/A-1921-2017 OI Wurden, Glen/0000-0003-2991-1484 NR 9 TC 10 Z9 10 U1 0 U2 0 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0920-3796 J9 FUSION ENG DES JI Fusion Eng. Des. PD MAR PY 1997 VL 34-35 BP 563 EP 566 DI 10.1016/S0920-3796(96)00621-7 PG 4 WC Nuclear Science & Technology SC Nuclear Science & Technology GA XL182 UT WOS:A1997XL18200107 ER PT J AU Chrien, RE Klare, KA Murphy, TJ Rauber, LA AF Chrien, RE Klare, KA Murphy, TJ Rauber, LA TI Calibration and operation of a neutron time-of-flight scintillator array on Nova SO FUSION ENGINEERING AND DESIGN LA English DT Article; Proceedings Paper CT 7th International Toki Conference on Plasma Physics and Controlled Nuclear Fusion Research (ITC-7) CY NOV 29-DEC 02, 1995 CL TOKI CITY, JAPAN SP Gifu Prefecture, Toki City, Japan Soc Plasma Phys & Nucl Fus Res, Fus Sci Org, Minist Educ, Japan ID TEMPERATURE-MEASUREMENTS; SPECTRA AB The Tion diagnostic is a 1020-channel scintillator array on the Nova laser at Livermore. It measures the arrival time of single D-D or D-T neutrons at 27 m from the target with time resolution of 4 ns. The effect of neutron scattering has been obtained from Monte-Carlo neutron transport simulations and the scattered response is convolved with a Gaussian source to fit the data. The data analysis has been checked using targets which produce roughly equal numbers of D-T and D-D counts. The temperature obtained from Tion and from a current-mode neutron time-of-flight detector are in agreement for neutron yields above 1 x 10(9). (C) 1997 Elsevier Science S.A. RP Chrien, RE (reprint author), LOS ALAMOS NATL LAB, POB 1663, LOS ALAMOS, NM 87545 USA. RI Murphy, Thomas/F-3101-2014 OI Murphy, Thomas/0000-0002-6137-9873 NR 11 TC 2 Z9 2 U1 0 U2 1 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0920-3796 J9 FUSION ENG DES JI Fusion Eng. Des. PD MAR PY 1997 VL 34-35 BP 577 EP 580 DI 10.1016/S0920-3796(96)00592-3 PG 4 WC Nuclear Science & Technology SC Nuclear Science & Technology GA XL182 UT WOS:A1997XL18200110 ER PT J AU Osakabe, M Sasao, M Roquemore, AL Johnson, LC Isobe, M Fujita, J Itoh, S AF Osakabe, M Sasao, M Roquemore, AL Johnson, LC Isobe, M Fujita, J Itoh, S TI Measurement of neutron energy for ICRF heated D-T plasma experiments SO FUSION ENGINEERING AND DESIGN LA English DT Article; Proceedings Paper CT 7th International Toki Conference on Plasma Physics and Controlled Nuclear Fusion Research (ITC-7) CY NOV 29-DEC 02, 1995 CL TOKI CITY, JAPAN SP Gifu Prefecture, Toki City, Japan Soc Plasma Phys & Nucl Fus Res, Fus Sci Org, Minist Educ, Japan ID SPECTRA AB In the next large tokamak facility such as the International Thermonuclear Experimental Reactor (ITER), the ion cyclotron range of frequency (ICRF) heating is one of the major techniques to heat the plasma. Due to the existence of the resonance peak for the D-T fusion reaction around 100 keV, the neutron yield of ICRF heated D-T plasma might decrease due to the growth of a high energy tritium ion tail when the temperature of the tail component exceeds similar to 150 keV. On the contrary, the peak width of the D-T neutron spectrum increases monotonically as the tail temperature increases. Therefore, the neutron spectrum measurement could be a useful tool for monitoring the effect of ICRF heating on D-T fusion plasma. In this paper, the necessary performance of a neutron spectrometer will be discussed. (C) 1997 Elsevier Science S.A. C1 PRINCETON PLASMA PHYS LAB, PRINCETON, NJ 08543 USA. ITER JOINT CENT TEAM, SAN DIEGO, CA USA. GRAD UNIV ADV STUDIES, NAGOYA, AICHI, JAPAN. NAGOYA UNIV, NAGOYA, AICHI, JAPAN. RP Osakabe, M (reprint author), NATL INST FUS SCI, CHIKUSA KU, NAGOYA, AICHI 46401, JAPAN. NR 3 TC 1 Z9 1 U1 1 U2 1 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0920-3796 J9 FUSION ENG DES JI Fusion Eng. Des. PD MAR PY 1997 VL 34-35 BP 599 EP 601 DI 10.1016/S0920-3796(96)00617-5 PG 3 WC Nuclear Science & Technology SC Nuclear Science & Technology GA XL182 UT WOS:A1997XL18200115 ER PT J AU Nilson, DG Carlstrom, TN Hill, DN Hsieh, CL Porter, GD Stockdale, RE Evans, JC AF Nilson, DG Carlstrom, TN Hill, DN Hsieh, CL Porter, GD Stockdale, RE Evans, JC TI Divertor Thomson scattering on DIII-D SO FUSION ENGINEERING AND DESIGN LA English DT Article; Proceedings Paper CT 7th International Toki Conference on Plasma Physics and Controlled Nuclear Fusion Research (ITC-7) CY NOV 29-DEC 02, 1995 CL TOKI CITY, JAPAN SP Gifu Prefecture, Toki City, Japan Soc Plasma Phys & Nucl Fus Res, Fus Sci Org, Minist Educ, Japan AB In this paper we describe the newly installed divertor Thomson scattering system for the DIII-D tokamak and present initial results from plasma discharges. Measured plasma densities have ranged from 5 x 10(18) to 5 x 10(20) m(-3) and divertor plasma temperatures from 1 to 500 eV. These data are compared with earlier Langmuir probe data and qualitatively compared with UEDGE computer simulations. The divertor Thomson system uses one of the eight existing core Thomson scattering lasers (1 J, 20 Hz) which has been re-directed to probe the divertor region of the DIII-D vessel. Scattered light from this multipulse Nd:Yag laser is viewed with an f/6.8 collection optics system which provides eight spatial channels from 1-21 cm above the vessel floor (divertor target), each with 1.5 cm vertical resolution. Translating the plasma across the vessel floor using position controls provides a full scan of the divertor plasma. (C) 1997 Elsevier Science S.A. C1 GEN ATOM CO, SAN DIEGO, CA 92186 USA. RP Nilson, DG (reprint author), LAWRENCE LIVERMORE NATL LAB, POB 808, LIVERMORE, CA 94550 USA. NR 2 TC 6 Z9 8 U1 0 U2 0 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0920-3796 J9 FUSION ENG DES JI Fusion Eng. Des. PD MAR PY 1997 VL 34-35 BP 609 EP 612 DI 10.1016/S0920-3796(96)00616-3 PG 4 WC Nuclear Science & Technology SC Nuclear Science & Technology GA XL182 UT WOS:A1997XL18200117 ER PT J AU Katsuta, T Takiyama, K Oda, T Mizuno, K Ogawa, T AF Katsuta, T Takiyama, K Oda, T Mizuno, K Ogawa, T TI Supersonic helium beam for measurement of electric field in torus plasma edges SO FUSION ENGINEERING AND DESIGN LA English DT Article; Proceedings Paper CT 7th International Toki Conference on Plasma Physics and Controlled Nuclear Fusion Research (ITC-7) CY NOV 29-DEC 02, 1995 CL TOKI CITY, JAPAN SP Gifu Prefecture, Toki City, Japan Soc Plasma Phys & Nucl Fus Res, Fus Sci Org, Minist Educ, Japan ID PROFILES AB Numerical investigations on the basis of a collisional-radiative model have been made on the measurement of the electric field in torus plasma edges using a supersonic helium beam with aid of laser excitation. In this simulation, the laser-induced fluorescence intensity of the He I 492.2 nm line associated with the forbidden excitation due to the Stark effect is estimated as a function of electric field strength. The results show that an electric field as low as 50 V cm(-1) can be measured by the supersonic beam with sufficient beam density (about 10(12) cm(-3)). A numerical discussion is also given on the measurement of the electron temperature and density. (C) 1997 Elsevier Science S.A. C1 UNIV CALIF DAVIS, LIVERMORE, CA 95616 USA. LAWRENCE LIVERMORE NATL LAB, PLASMA PHYS RES INST, LIVERMORE, CA USA. JAPAN ATOM ENERGY RES INST, TOKAI, IBARAKI 31911, JAPAN. RP Katsuta, T (reprint author), HIROSHIMA UNIV, FAC ENGN, DEPT APPL PHYS & CHEM, HIGASHIHIROSHIMA 739, JAPAN. NR 6 TC 7 Z9 9 U1 1 U2 2 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0920-3796 J9 FUSION ENG DES JI Fusion Eng. Des. PD MAR PY 1997 VL 34-35 BP 769 EP 772 DI 10.1016/S0920-3796(96)00548-0 PG 4 WC Nuclear Science & Technology SC Nuclear Science & Technology GA XL182 UT WOS:A1997XL18200152 ER PT J AU Mitchison, HM Munroe, PB ORawe, AM Taschner, PEM DeVos, N Kremmidiotis, G Lensink, I Munk, AC DArigo, KL Anderson, JW Lerner, TJ Moyzis, RK Callen, DF Breuning, MH Doggett, NA Gardiner, RM Mole, SE AF Mitchison, HM Munroe, PB ORawe, AM Taschner, PEM DeVos, N Kremmidiotis, G Lensink, I Munk, AC DArigo, KL Anderson, JW Lerner, TJ Moyzis, RK Callen, DF Breuning, MH Doggett, NA Gardiner, RM Mole, SE TI Genomic structure and complete nucleotide sequence of the Batten disease gene, CLN3 SO GENOMICS LA English DT Article ID TRANSCRIPTION FACTORS; REPETITIVE DNA; COMPILATION AB We recently cloned a cDNA for CLN3, the gene for juvenile-onset neuronal ceroid lipofuscinosis or Batten disease. To resolve the genomic organization we used a cosmid clone containing CLN3 to sequence the entire gene in addition to 1.1 kb 5' of the start of the published CLN3 cDNA and 0.3 kb 3' to the polyadenylation site. CLN3 is organized into at least 15 exons spanning 15 kb and ranging from 47 to 356 bp. The 14 introns vary from 80 to 4227 bp, and all exon/intron junction sequences conform to the GT/AG rule. Numerous repetitive Alu elements are present within the introns and 5'- and 3'-untranslated regions. The 5' region of the CLN3 gene contains several potential transcription regulatory elements but no consensus TATA-1 box was identified. CLN3 is homologous to 27 deposited human ESTs, and sequence comparisons suggest alternative splicing of the gene and the existence of transcribed sequences upstream to the start of the published CLN3 cDNA. (C) 1997 Academic Press. C1 LEIDEN UNIV,DEPT HUMAN GENET,NL-2333 AL LEIDEN,NETHERLANDS. WOMENS & CHILDRENS HOSP,DEPT CYTOGENET & MOL GENET,ADELAIDE,SA 5006,AUSTRALIA. LOS ALAMOS NATL LAB,DIV LIFE SCI,LOS ALAMOS,NM 87545. LOS ALAMOS NATL LAB,CTR HUMAN GENOME STUDIES,LOS ALAMOS,NM 87545. MASSACHUSETTS GEN HOSP,MOL NEUROGENET UNIT,CHARLESTOWN,MA 02129. HARVARD UNIV,SCH MED,DEPT NEUROL,BOSTON,MA 02114. RP Mitchison, HM (reprint author), UNIV LONDON UNIV COLL,SCH MED,RAYNE INST,DEPT PAEDIAT,UNIV ST,LONDON WC1E 6JJ,ENGLAND. RI Mitchison, Hannah/C-1891-2008; Mole, Sara/C-2024-2008; Breuning, Martijn/E-3429-2010; Callen, David/G-1975-2012; Taschner, Peter/J-8853-2014; OI Mole, Sara/0000-0003-4385-4957; Taschner, Peter/0000-0001-9621-465X; Callen, David/0000-0002-6189-9991 FU NINDS NIH HHS [NS28722, NS30152, NS32009]; Wellcome Trust NR 20 TC 35 Z9 36 U1 0 U2 1 PU ACADEMIC PRESS INC JNL-COMP SUBSCRIPTIONS PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 SN 0888-7543 J9 GENOMICS JI Genomics PD MAR 1 PY 1997 VL 40 IS 2 BP 346 EP 350 DI 10.1006/geno.1996.4576 PG 5 WC Biotechnology & Applied Microbiology; Genetics & Heredity SC Biotechnology & Applied Microbiology; Genetics & Heredity GA WN317 UT WOS:A1997WN31700017 PM 9119403 ER PT J AU Brady, PV Gislason, SR AF Brady, PV Gislason, SR TI Seafloor weathering controls on atmospheric CO2 and global climate SO GEOCHIMICA ET COSMOCHIMICA ACTA LA English DT Article ID MID-OCEAN RIDGES; EARTHS SURFACE-TEMPERATURE; HYDROTHERMAL CIRCULATION; BASALTIC GLASS; CARBON-CYCLE; OLIVINE DISSOLUTION; CHEMICAL EXCHANGE; NEGATIVE FEEDBACK; PHANEROZOIC TIME; DSDP SITE-417 AB Alteration of surficial marine basalts at low temperatures (<40 degrees C) is a potentially important sink for atmospheric CO2 over geologic time. Petrologic analyses, thermodynamic calculations, and experimental weathering results point to extensive Ca leaching and consumption of marine CO2 during alteration Basalt weathering in seawater-like solutions is sensitive to temperature. The activation energy for initial basalt weathering in seawater is 41-65 Kj mol(-1). If seafloor weathering temperatures are set by deep ocean fluids under high fluid to rock ratios the feedback between weathering and atmospheric CO2 is indirect, but sizeable. If the bulk of seafloor weathering occurs in the presence of low-temperature hydrothermal fluids, the weathering feedback depends on the linkage between spreading rates and heat flow. In either case, the primary linkage between seafloor weathering and the global carbon cycle appears to be thermal as opposed to chemical. Copyright (C) 1997 Elsevier Science Ltd. C1 UNIV ICELAND,INST SCI,IS-107 REYKJAVIK,ICELAND. RP Brady, PV (reprint author), SANDIA NATL LABS,POB 5800,ALBUQUERQUE,NM 87185, USA. NR 81 TC 78 Z9 79 U1 2 U2 11 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0016-7037 J9 GEOCHIM COSMOCHIM AC JI Geochim. Cosmochim. Acta PD MAR PY 1997 VL 61 IS 5 BP 965 EP 973 DI 10.1016/S0016-7037(96)00385-7 PG 9 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA WN032 UT WOS:A1997WN03200003 ER PT J AU Weiss, LA Lambour, RL Elphic, RC Thomsen, MF AF Weiss, LA Lambour, RL Elphic, RC Thomsen, MF TI Study of plasmaspheric evolution using geosynchronous observations and global modeling SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID MAGNETOSPHERIC PLASMA ANALYZER; REGIONS; DAYSIDE; ORBIT AB We examine the dynamics of the outer plasmasphere during a 3-day interval in February, 1992 by comparing observations from three widely-spaced geosynchronous satellites with the predictions of the Magnetospheric Specification and Forecast Model (MSFM). For this study the MSFM was modified to include a cold, plasmaspheric population subject to the effects of corotation, convection, and ionospheric refilling. The model does a very good job of reproducing the observations; in particular, it clearly shows the formation and westward transport of duskside plasmaspheric plumes, accounting fbr the progressively earlier local time observations of cold ions following periods of enhanced convection. The MSFM's ability to model dynamically the evolution of the outer plasmasphere under varying solar wind conditions improves upon previous plasmaspheric models and has aided our understanding of spatially and temporally separated observations of plasmaspheric ions at geosynchronous orbit. C1 LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545. RP Weiss, LA (reprint author), MIT,LINCOLN LAB,244 WOOD ST,LEXINGTON,MA 02173, USA. NR 25 TC 34 Z9 34 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD MAR 1 PY 1997 VL 24 IS 5 BP 599 EP 602 DI 10.1029/97GL00351 PG 4 WC Geosciences, Multidisciplinary SC Geology GA WL742 UT WOS:A1997WL74200027 ER PT J AU Majer, EL Peterson, JE Daley, T Kaelin, B Myer, L Queen, J DOnfro, P Rizer, W AF Majer, EL Peterson, JE Daley, T Kaelin, B Myer, L Queen, J DOnfro, P Rizer, W TI Fracture detection using crosswell and single well surveys SO GEOPHYSICS LA English DT Article ID ANISOTROPY; WAVES AB We recorded high-resolution (1 to 10 kHz), crosswell and single well seismic data in a shallow (15 to 35 m), water-saturated, fractured limestone sequence at Conoco's borehole test facility near Newkirk, Oklahoma. Our objective was to develop seismic methodologies for imaging gas-filled fractures in naturally fractured gas reservoirs. The crosswell (1/4 m receiver spacing, 50 to 100 m well separation) surveys used a piezoelectric source and hydrophones before, during, and after an air injection that we designed to displace water from a fracture zone. Our intent was to increase the visibility of the fracture zone to seismic imaging and to confirm previous hydrologic data that indicated a preferred pathway. For the single well seismic imaging (a piezoelectric source and an eight-element hydrophone array at 1/4 m spacing), we also recorded data before and after the air injection. The crosswell results indicate that the air did follow a preferred pathway that was predicted by hydrologic modeling. In addition, the single well seismic imaging using vertical common depth-point (CDP) gathers indicated an anomaly consistent with the anomaly location of crosswell and hydrologic inversion results. Following the field tests, a slant well was drilled and cored to confirm the existence and nature of the rock associated with the seismic anomalies. A vertical fracture was intersected within less than 1 m of where the seismic results had predicted. C1 CONOCO INC,PONCA CITY,OK 74603. RP Majer, EL (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV EARTH SCI,CTR COMPUTAT SEISMOL,BERKELEY,CA 94720, USA. RI Daley, Thomas/G-3274-2015 OI Daley, Thomas/0000-0001-9445-0843 NR 11 TC 22 Z9 22 U1 0 U2 5 PU SOC EXPLORATION GEOPHYSICISTS PI TULSA PA 8801 S YALE ST, TULSA, OK 74137 SN 0016-8033 J9 GEOPHYSICS JI Geophysics PD MAR-APR PY 1997 VL 62 IS 2 BP 495 EP 504 DI 10.1190/1.1444160 PG 10 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA WQ457 UT WOS:A1997WQ45700010 ER PT J AU Post, WM King, AW Wullschleger, SD AF Post, WM King, AW Wullschleger, SD TI Historical variations in terrestrial biospheric carbon storage SO GLOBAL BIOGEOCHEMICAL CYCLES LA English DT Article ID PAST 2 CENTURIES; CLIMATE-CHANGE; ATMOSPHERIC CARBON; LAND-USE; MODEL; CO2; CYCLE; SENSITIVITY; SIMULATION; VEGETATION AB Changes in carbon storage in terrestrial ecosystems are a consequence of shifts in the balance between net primary production (NPP) and heterotrophic respiration (RH) Historical climatic variations which favored NPP over RH may have led to increased ecosystem carbon storage and might account for at least part of the ''missing'' sink required to balance the current century's global carbon budget. To test this hypothesis, we employed a georeferenced global terrestrial biosphere model of 0.5 degrees spatial resolution. The model was driven from an assumed equilibrium in 1900 using gridded historical time series of monthly temperature and precipitation and the historical record of changes in atmospheric CO2 concentration. Interannual variability in climate induced interannual changes in terrestrial biospheric carbon storage and net carbon exchange with the atmosphere of the order of 1-2 Gt C yr(-1). With climate change alone, global biospheric carbon storage declined by 1% (23 Ct C) over the period 1900-1988. With the addition of a moderate CO2 fertilization response, biospheric carbon storage increased by 3% (57 Gt C), primarily as a consequence of changes in NPP and litter inputs to the soil system. With CO2 fertilization, the model's cumulative carbon sink for the period 1900-1988 accounts for about 69% of the missing sink derived by deconvolution. For the period 1950-1988, the modeled sink is about 56% of the missing sink. Our results suggest that the temporal evolution of the missing sink over the period 1900-1988 could be a response of the terrestrial biosphere to changes in climate and atmospheric CO2 or perhaps climate change alone. The discrepancy in the magnitudes of the modeled and deconvolved sinks may be due to limitations of the biospheric model or to overestimates of the land-use source flux. RP Post, WM (reprint author), OAK RIDGE NATL LAB, DIV ENVIRONM SCI, POB 2008, OAK RIDGE, TN 37831 USA. RI Wullschleger, Stan/B-8297-2012; Post, Wilfred/B-8959-2012 OI Wullschleger, Stan/0000-0002-9869-0446; NR 46 TC 56 Z9 62 U1 0 U2 9 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0886-6236 EI 1944-9224 J9 GLOBAL BIOGEOCHEM CY JI Glob. Biogeochem. Cycle PD MAR PY 1997 VL 11 IS 1 BP 99 EP 109 DI 10.1029/96GB03942 PG 11 WC Environmental Sciences; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences SC Environmental Sciences & Ecology; Geology; Meteorology & Atmospheric Sciences GA WL541 UT WOS:A1997WL54100007 ER PT J AU Stone, WJ AF Stone, WJ TI Low-flow ground water sampling - Is it a cure-all? SO GROUND WATER MONITORING AND REMEDIATION LA English DT Editorial Material ID MONITORING WELLS RP Stone, WJ (reprint author), US DOE,NMED,OB,POB 5400,ALBUQUERQUE,NM 87185, USA. NR 13 TC 9 Z9 9 U1 0 U2 1 PU GROUND WATER PUBLISHING CO PI WESTERVILLE PA 601 DEMPSEY RD, WESTERVILLE, OH 43081 SN 1069-3629 J9 GROUND WATER MONIT R JI Ground Water Monit. Remediat. PD SPR PY 1997 VL 17 IS 2 BP 70 EP 72 PG 3 WC Water Resources SC Water Resources GA XA872 UT WOS:A1997XA87200005 ER PT J AU Patton, GW Cooper, AT Tinker, MR AF Patton, GW Cooper, AT Tinker, MR TI Ambient air sampling for tritium-determination of breakthrough volumes and collection efficiencies for silica gel adsorbent SO HEALTH PHYSICS LA English DT Article DE air sampling; tritium; adsorption; radioactivity, airborne AB Ambient air samples for tritium (as HTO) can be collected using the solid adsorbent silica gel. The purpose of this study was to determine the maximum practical sampling volume and overall collection efficiency for water vapor collected on silica gel columns and to demonstrate the use of an impinger-based system to load water vapor onto silica gel columns. Breakthrough volumes (V-b) were measured and chromatographic efficiencies (expressed as the number of theoretical plates, N) were calculated for a 20 degrees C to 50 degrees C temperature range, with the relative humidity at approximately 30%. The tests yielded relative breakthrough volumes (air volume/adsorbent depth, m(3) cm(-1)) of 0.36 for 20 degrees C, 0.20 for 30 degrees C, 0.15 for 40 degrees C, and 0.077 for 50 degrees C. For 18-cm columns, the average tritium tracer recoveries at 20 degrees C were 71% with no observed breakthrough for air volumes up to 5 m(3), while at 40 degrees C mean tritium tracer recoveries dropped from 75% for volumes less than or equal to 3.0 m(3), to 0% for a volume of 5.0 m(3). Frontal chromatographic profiles were measured for water vapor migrating through silica gel columns that were divided into 5 segments. The chromatographic efficiency of the silica gel columns was determined by graphical evaluation of the chromatography profiles. At a sampling rate of 0.25 L min(-1) and 30% relative humidity, the number of theoretical plates per adsorbent depth were 0.55 N cm(-1) at 20 degrees C, 0.68 N cm(-1) at 30 degrees C, 0.51 N cm(-1) at 40 degrees C, and 0.30 N cm(-1) at 50 degrees C. Chromatographic theory was used to estimate the overall collection efficiency of the silica gel columns as a function of the ratio of the sampling volume to breakthrough volume and the chromatographic efficiency. For a 9.5 m(3) sample volume, 30% relative humidity, 0.25 L min(-1) sampling rate, and a 54-cm column, the overall collection efficiency was above 99.9% at 20 degrees C, above 95% at 30 degrees C, just below 80% at 40 degrees C, and much less than 80% at 50 degrees C. C1 PACIFIC NW LAB, RICHLAND, WA 99352 USA. NR 16 TC 6 Z9 6 U1 2 U2 5 PU LIPPINCOTT WILLIAMS & WILKINS PI PHILADELPHIA PA 530 WALNUT ST, PHILADELPHIA, PA 19106-3621 USA SN 0017-9078 EI 1538-5159 J9 HEALTH PHYS JI Health Phys. PD MAR PY 1997 VL 72 IS 3 BP 397 EP 407 DI 10.1097/00004032-199703000-00007 PG 11 WC Environmental Sciences; Public, Environmental & Occupational Health; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Environmental Sciences & Ecology; Public, Environmental & Occupational Health; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA WJ338 UT WOS:A1997WJ33800008 PM 9030841 ER PT J AU Yasumura, S Ma, R Weber, DA Dilmanian, FA Zhao, M LoMonte, AF Moore, RI Skelany, R Pierson, RN AF Yasumura, S Ma, R Weber, DA Dilmanian, FA Zhao, M LoMonte, AF Moore, RI Skelany, R Pierson, RN TI A modified bottle manikin phantom for in vivo neutron activation analysis SO HEALTH PHYSICS LA English DT Article DE phantom; neutron activation; skeleton; Reference Man ID FUTURE-PROSPECTS; STATE; MASS; ART AB An artificial skeleton was designed and placed inside a bottle manikin absorber phantom to provide a new reference standard for measurements of total body calcium by in vivo neutron activation analysis at Brookhaven National Laboratory, The composition of the epoxy-based calcium and phosphorus mixture used to construct the skeleton, the dimensions and weight of each bone are given for two phantoms representing an adult male and female, Also, the dimensions, composition, and weights of overlays designed to simulate the influence of obesity on in vivo neutron activation analysis are given for each. C1 BROOKHAVEN NATL LAB, DEPT MED, UPTON, NY 11973 USA. UNIV CALIF DAVIS, MED CTR, DEPT RADIOL, SACRAMENTO, CA 95817 USA. ST LUKES ROOSEVELT HOSP, BODY COMPOSIT UNIT, NEW YORK, NY 10025 USA. FU NIDDK NIH HHS [P01-DK42618] NR 16 TC 10 Z9 10 U1 0 U2 0 PU LIPPINCOTT WILLIAMS & WILKINS PI PHILADELPHIA PA 530 WALNUT ST, PHILADELPHIA, PA 19106-3621 USA SN 0017-9078 EI 1538-5159 J9 HEALTH PHYS JI Health Phys. PD MAR PY 1997 VL 72 IS 3 BP 443 EP 449 DI 10.1097/00004032-199703000-00012 PG 7 WC Environmental Sciences; Public, Environmental & Occupational Health; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Environmental Sciences & Ecology; Public, Environmental & Occupational Health; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA WJ338 UT WOS:A1997WJ33800013 PM 9030846 ER PT J AU Zaromb, S Justus, A Munyon, W Reilly, D Chen, B AF Zaromb, S Justus, A Munyon, W Reilly, D Chen, B TI A novel portable grab sampler for tritiated water vapor SO HEALTH PHYSICS LA English DT Article DE operational topic; air sampling; tritium; water AB The purpose of this work was to evaluate the applicability of a recently developed portable high-throughput liquid-absorption air sampler for measuring tritiated water vapor concentrations in nuclear facilities. A procedure for sampling tritiated water,vith a portable high-throughput liquid-absorption air sampler and measuring its concentration in air was developed with the aid of a theoretical model. Tritium concentrations in the air of a heavy water reactor currently being decommissioned, derived from samples obtained with a portable high throughput liquid-absorption air sampler, a bubbler, and a cold trap, yielded comparable results, suggesting the applicability of the portable high-throughput liquid-absorption air sampler to tritium grab sampling. C1 ZAROMB RES CORP, HINSDALE, IL 60521 USA. ARGONNE NATL LAB, ENVIRONM SAFETY & HLTH DIV, ARGONNE, IL 60439 USA. NR 4 TC 4 Z9 4 U1 0 U2 1 PU LIPPINCOTT WILLIAMS & WILKINS PI PHILADELPHIA PA 530 WALNUT ST, PHILADELPHIA, PA 19106-3621 USA SN 0017-9078 EI 1538-5159 J9 HEALTH PHYS JI Health Phys. PD MAR PY 1997 VL 72 IS 3 BP 481 EP 485 DI 10.1097/00004032-199703000-00018 PG 5 WC Environmental Sciences; Public, Environmental & Occupational Health; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Environmental Sciences & Ecology; Public, Environmental & Occupational Health; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA WJ338 UT WOS:A1997WJ33800019 PM 9030852 ER PT J AU Taylor, BE Scott, DE AF Taylor, BE Scott, DE TI Effects of larval density dependence on population dynamics of Ambystoma opacum SO HERPETOLOGICA LA English DT Article DE Ambystoma opacum; amphibians; complex life cycle; density-dependence; model ID SALAMANDER; COMPETITION; TALPOIDEUM; PREDATION; GROWTH; SIZE; PEDOMORPHOSIS; METAMORPHOSIS; FLUCTUATIONS; RECRUITMENT AB Using data and insights derived from laboratory experiments, 9 yr of field experiments, and numerous observations of natural populations of the marbled salamander, Ambystoma opacum, we constructed a model to study the effects of larval density dependence on population dynamics. The model includes density-dependent larval survival and size at metamorphosis, density-independent survival in other stages, and size- and age-dependent terrestrial growth and reproduction. Terrestrial females are tracked individually. When survival in non-larval stages is high, equilibria are unstable, and high reproductive potential at low population densities leads to population dynamics with wide fluctuations. Density-dependent larval regulation, which decreases in intensity with decreasing survival in other stages, is much more sensitive to terrestrial survival than to egg survival. Density-dependent size at metamorphosis delays reproduction by as much as 3 yr and reduces average clutch size by as much as 70%. Applied to a natural population with low annual recruitment (range 0.7-7.9 metamorphs per breeding female over 9 yr), model results indicate that either high terrestrial survival (>0.7 yr(-1)) or immigration is required to maintain the population. The general sensitivity of the model population to terrestrial parameters underscores the importance of additional data on the demography of the terrestrial stages, as well as on processes controlling year-to-year variation in recruitment of larvae. This information is critical to understanding population regulation and to developing an adequate basis for conservation or management plans. RP Taylor, BE (reprint author), SAVANNAH RIVER ECOL LAB,DRAWER E,AIKEN,SC 29802, USA. NR 39 TC 43 Z9 44 U1 2 U2 15 PU HERPETOLOGISTS LEAGUE PI JOHNSON CITY PA EAST TENNESSEE STATE UNIV, DEPT BIOLOGICAL SCIENCES, BOX 70726, JOHNSON CITY, TN 37614-0726 SN 0018-0831 J9 HERPETOLOGICA JI Herpetologica PD MAR PY 1997 VL 53 IS 1 BP 132 EP 145 PG 14 WC Zoology SC Zoology GA WQ552 UT WOS:A1997WQ55200013 ER PT J AU Thelen, DC Chu, DD AF Thelen, DC Chu, DD TI A low noise readout detector circuit for nanoampere sensor applications SO IEEE JOURNAL OF SOLID-STATE CIRCUITS LA English DT Article DE detectors; image sensors; integrated circuit noise; intelligent sensors; photodiodes; switched-capacitor circuits ID SWITCHED-CAPACITOR INTEGRATOR; AMPLIFIER AB A readout detector IC has been developed which is capable of detecting nanoampere photo-current signals of interest in a high (microampere) background illumination or de noise level (SNR = 80 dB), The readout detector sensor IC processes transient signals of interest from a separate photo-diode pixel array chip, Low noise signal conditioning, filtering, and signal thresholding implement smart sensor detection of only ''active pixels.'' This detector circuit can also be used to perform signal conditioning for other sensor applications that require detection of very small signals in a high background noise environment. C1 SANDIA NATL LABS,ALBUQUERQUE,NM 87185. RP Thelen, DC (reprint author), UNIV NEW MEXICO,MICROELECT RES CTR,ALBUQUERQUE,NM 87106, USA. NR 8 TC 3 Z9 3 U1 0 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9200 J9 IEEE J SOLID-ST CIRC JI IEEE J. Solid-State Circuit PD MAR PY 1997 VL 32 IS 3 BP 337 EP 348 DI 10.1109/4.557631 PG 12 WC Engineering, Electrical & Electronic SC Engineering GA WK553 UT WOS:A1997WK55300006 ER PT J AU Ferreira, HC Clarke, WA Helberg, ASJ AbdelGhaffar, KAS Vinck, AJH AF Ferreira, HC Clarke, WA Helberg, ASJ AbdelGhaffar, KAS Vinck, AJH TI Insertion/deletion correction with spectral nulls SO IEEE TRANSACTIONS ON INFORMATION THEORY LA English DT Article; Proceedings Paper CT 1996 International Symposium on Information Theory and Its Applications (ISITA 96) CY SEP 17-20, 1996 CL VICTORIA, CANADA SP IEEE DE insertion/deletion correction; spectral nulls; constrained codes; balanced codes ID CONSTANT WEIGHT CODES; FREE BLOCK CODE; DC FREE; LOWER BOUNDS AB Levenshtein proposed a class of single insertion/deletion correcting codes, based on the number-theoretic construction due to Varshamov and Tenengolt's. We present several interesting results on the binary structure of these codes, and their relation to constrained codes with nulls in the power spectral density function. One surprising result is that the higher order spectral null codes of Immink and Beenker are subcodes of balanced Levenshtein codes. Other spectral null subcodes with similar coding rates, may also be constructed. We furthermore present some coding schemes and spectral shaping markers which alleviate the fundamental restriction on Levenshtein's codes that the boundaries of each codeword should be known before insertion/deletion correction can be effected. C1 LAWRENCE LIVERMORE NATL LAB,DEPT ELECT & COMP ENGN,DAVIS,CA 95616. UNIV GHS ESSEN,INST EXPT MATH,D-45326 ESSEN,GERMANY. RP Ferreira, HC (reprint author), RAND AFRIKAANS UNIV,DEPT ELECT & ELECT ENGN,POB 524,ZA-2006 AUCKLAND PK,SOUTH AFRICA. RI Helberg, Albert/E-6771-2011 NR 20 TC 25 Z9 25 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9448 J9 IEEE T INFORM THEORY JI IEEE Trans. Inf. Theory PD MAR PY 1997 VL 43 IS 2 BP 722 EP 732 DI 10.1109/18.556130 PG 11 WC Computer Science, Information Systems; Engineering, Electrical & Electronic SC Computer Science; Engineering GA WK548 UT WOS:A1997WK54800030 ER PT J AU Turner, LR AF Turner, LR TI Fields and forces in flywheel energy storage with high-temperature superconducting bearings SO IEEE TRANSACTIONS ON MAGNETICS LA English DT Article; Proceedings Paper CT 7th Biennial IEEE Conference on Electromagnetic Field Computation (IEEE CEFC 96) CY MAR 18-20, 1996 CL OKAYAMA, JAPAN SP IEEE, Okayama Univ, Dept Elect & Electr Engn, IEEE Magnet Soc ID PERMANENT AB The development of low-loss bearings employing high-temperature superconductors has brought closer the advent of practical flywheel energy storage systems, These systems require magnetic fields and forces for levitation, stabilization, and energy transfer, This paper describes the status of experiments on flywheel energy storage at Argonne National Laboratory and computations in support of that project, in particular computations for the permanent-magnet rotor of the motor-generator that transfers energy to and from the flywheel, for other energy-transfer systems under consideration, and for the levitation and stabilization subsystem. RP Turner, LR (reprint author), ARGONNE NATL LAB,DIV ENERGY TECHNOL,9700 S CASS AVE,ARGONNE,IL 60439, USA. NR 6 TC 3 Z9 3 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9464 J9 IEEE T MAGN JI IEEE Trans. Magn. PD MAR PY 1997 VL 33 IS 2 BP 2000 EP 2003 DI 10.1109/20.582693 PN 2 PG 4 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA WN991 UT WOS:A1997WN99100211 ER PT J AU Vianco, PT Sifford, CH Romero, JA AF Vianco, PT Sifford, CH Romero, JA TI Resistivity and adhesive strength of thin film metallizations on single crystal quartz SO IEEE TRANSACTIONS ON ULTRASONICS FERROELECTRICS AND FREQUENCY CONTROL LA English DT Article AB Resistivity and adhesive strength were measured for the thin films 450 Angstrom Cr-1800 Angstrom Au, 450 Angstrom Cr-1000 Angstrom Mo-1800 Angstrom Au, 450 Angstrom Cr-1000 Angstrom Ni-1800 Angstrom Au, 450 Angstrom Mo-1800 Angstrom Au, 1800 Angstrom Au, and 2000 Angstrom Al on z- and AT-oriented single crystal quartz substrates in the as deposited condition as well as after thermal annealing at 380 degrees C and 450 degrees C for 30 min in air or vacuum. The Cr-Au films exhibited significant resistivity increases after thermal annealing which were caused by the interdiffusion of Cr and Au. Barrier layers of Mo or Ni limited such increases after heat treatment. The Mo-Au, Au, and Al films exhibited resistivity decreases following thermal annealing. The mean adhesive strengths of the Cr-Au, Cr-Mo-Au, and Cr-Ni-Au films were excellent in the as-deposited and annealed conditions, ranging from 41 MPa to 70 MPa. The Mo-Au and Au films maintained relatively poor adhesion under all circumstances. Heat treatment improved the poor adhesive strength of the as-deposited Al films to values exceeding 63 MPa. Resistivity and adhesive strengths did not differ significantly between the z- and AT-oriented substrates. RP Vianco, PT (reprint author), SANDIA NATL LABS,POB 5800,ALBUQUERQUE,NM 87185, USA. NR 19 TC 6 Z9 6 U1 2 U2 3 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0885-3010 J9 IEEE T ULTRASON FERR JI IEEE Trans. Ultrason. Ferroelectr. Freq. Control PD MAR PY 1997 VL 44 IS 2 BP 237 EP 249 DI 10.1109/58.585109 PG 13 WC Acoustics; Engineering, Electrical & Electronic SC Acoustics; Engineering GA WR981 UT WOS:A1997WR98100001 PM 18244122 ER PT J AU Fisk, WJ Faulkner, D Sullivan, D Bauman, F AF Fisk, WJ Faulkner, D Sullivan, D Bauman, F TI Air change effectiveness and pollutant removal efficiency during adverse mixing conditions SO INDOOR AIR-INTERNATIONAL JOURNAL OF INDOOR AIR QUALITY AND CLIMATE LA English DT Article DE air change effectiveness; buildings; efficiency; exposure; pollutant; ventilation AB The air change effectiveness (ACE), an indicator of the indoor airflow pattern, was measured in twenty-six laboratory experiments. Ventilation air was supplied through induction-type diffusers located in the ceiling and removed through a ceiling-mounted return grille. The tracer-gas step-up measurement procedure was employed. In five of the experiments, pollutant removal efficiencies were also measured for simulated pollutant emissions from the floor covering and for simulated emissions from occupants. In experiments with heated supply air, supply airflow rates typical of the minimum supply now rates of VAV ventilation systems, and 100% outside air, the ACE ranged from 0.69 to 0.89. These results indicate that significant short-circuiting of ventilation air between the supply air diffuser and return air grille does occur under these adverse conditions. Mechanical recirculation of air, so that the supply air contained approximately 50% outside air, increased the ACE by about 0.05. When the supply air was cooled, the ACE ranged from 0.99 to 1.15, adding to existing evidence that short-circuiting is rarely a problem when the building is being cooled. The pollutant removal efficiency for simulated pollutant emissions from the floor covering (PREfloor) was strongly correlated with ACE (R-2=0.98) and the values of PREfloor were within approximately 0.1 of the values of ACE. The pollutant removal efficiency for simulated pollutant emissions by occupants varied between workstations and was not as well correlated with the ACE. C1 UNIV CALIF BERKELEY,CTR ENVIRONM DESIGN RES,BERKELEY,CA 94720. RP Fisk, WJ (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV ENERGY & ENVIRONM,INDOOR ENVIRONM PROGRAM,BERKELEY,CA 94720, USA. NR 14 TC 20 Z9 20 U1 2 U2 9 PU MUNKSGAARD INT PUBL LTD PI COPENHAGEN PA 35 NORRE SOGADE, PO BOX 2148, DK-1016 COPENHAGEN, DENMARK SN 0905-6947 J9 INDOOR AIR JI Indoor Air-Int. J. Indoor Air Qual. Clim. PD MAR PY 1997 VL 7 IS 1 BP 55 EP 63 DI 10.1111/j.1600-0668.1997.t01-3-00007.x PG 9 WC Construction & Building Technology; Engineering, Environmental; Public, Environmental & Occupational Health SC Construction & Building Technology; Engineering; Public, Environmental & Occupational Health GA WW289 UT WOS:A1997WW28900007 ER PT J AU Gullikson, EM Koshevoi, MO Lukyantsev, IV Rupasov, AA Fedin, DA Fedorchuk, RV Shikanov, AS Shpolskii, MR AF Gullikson, EM Koshevoi, MO Lukyantsev, IV Rupasov, AA Fedin, DA Fedorchuk, RV Shikanov, AS Shpolskii, MR TI Determination of the spatial resolution of X-ray films SO INSTRUMENTS AND EXPERIMENTAL TECHNIQUES LA English DT Article AB A method of spatial resolution determination of X-ray films is described. The technique is based on the use of a mask with a pattern of randomly distributed transmitting and nontransmitting areas. Images on X-ray materials were obtained with the use of synchrotron radiation from the S-60 (FIAN) synchrotron. It is suggested that X-ray images can be processed by the linear filter technique, The results of test measurements using RAR2490 and Kodak 10106 X-ray films are presented and compared with data obtained by other methods. C1 RUSSIAN ACAD SCI,PN LEBEDEV PHYS INST,FIAN,MOSCOW 117924,RUSSIA. GOSNIIKHIMFOTOPROJECT,MOSCOW,RUSSIA. RP Gullikson, EM (reprint author), LAWRENCE BERKELEY LAB,BERKELEY,CA 94720, USA. RI Rupasov, Alexander/N-2746-2015; Shikanov, Andrey/N-2724-2015 NR 9 TC 0 Z9 0 U1 0 U2 0 PU PLENUM PUBL CORP PI NEW YORK PA CONSULTANTS BUREAU, 233 SPRING ST, NEW YORK, NY 10013 SN 0020-4412 J9 INSTRUM EXP TECH+ JI Instrum. Exp. Tech. PD MAR-APR PY 1997 VL 40 IS 2 BP 256 EP 259 PG 4 WC Engineering, Multidisciplinary; Instruments & Instrumentation SC Engineering; Instruments & Instrumentation GA XL044 UT WOS:A1997XL04400028 ER PT J AU Maudlin, PJ Foster, JC Jones, SE AF Maudlin, PJ Foster, JC Jones, SE TI A continuum mechanics code analysis of steady plastic wave propagation in the Taylor test SO INTERNATIONAL JOURNAL OF IMPACT ENGINEERING LA English DT Article DE plastic wave propagation; Taylor cylinder test; jump conditions AB Simple conservation relationships (jump conditions) in conjunction with postulated material constitutive behavior are applied to steady plastic strain waves propagating in problems of uniaxial stress and Taylor Cylinder Impact. These problems are simulated with a two-dimensional Lagrangian continuum mechanics code for the purpose of numerically validating the jump relationships as an accurate analytical representation of plastic wave propagation. The constitutive behavior used in this effort assumes isotropy and models the thermodynamic response with a Mie-Grunisen Equation-of-State and the mechanical response with the rate-dependent Johnson-Cook and MTS flow stress models. The jump relationships successfully replicate the results produced by continuum code simulations of plastic wave propagation and provide a methodology for constructing mechanical constitutive models from experimental plastic wave speed information. Comparisons are also presented between experimental speeds from Taylor Cylinder Impact tests with jump relationships and continuum code predictions, indicating that the above mentioned flow stress models may not accurately capture plastic wave propagation speeds in annealed and hardened copper. Copyright (C) 1997 Elsevier Science Ltd. C1 WRIGHT LAB,ARMAMENT DIRECTORATE,EGLIN AFB,FL 32542. UNIV ALABAMA,DEPT AEROSP ENGN & MECH,TUSCALOOSA,AL 35487. RP Maudlin, PJ (reprint author), UNIV CALIF LOS ALAMOS NATL LAB,DIV THEORET,GRP T 3,LOS ALAMOS,NM 87545, USA. NR 27 TC 7 Z9 9 U1 0 U2 4 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0734-743X J9 INT J IMPACT ENG JI Int. J. Impact Eng. PD MAR PY 1997 VL 19 IS 3 BP 231 EP 256 DI 10.1016/S0734-743X(96)00021-8 PG 26 WC Engineering, Mechanical; Mechanics SC Engineering; Mechanics GA WG052 UT WOS:A1997WG05200003 ER PT J AU Stephenson, JL McLuckey, SA AF Stephenson, JL McLuckey, SA TI Adaptation of the Paul Trap for study of the reaction of multiply charged cations with singly charged anions SO INTERNATIONAL JOURNAL OF MASS SPECTROMETRY LA English DT Article DE multiply charged ions; quadrupole ion trap; ion-ion reactions; electrospray; glow discharge ID QUADRUPOLE ION-TRAP; GAS-PHASE; MASS-SPECTROMETER; ELECTROSPRAY IONIZATION; MOLECULE REACTIONS; CHEMICAL-IONIZATION; NEGATIVE-IONS; CYTOCHROME-C; DISSOCIATION; RESOLUTION AB The adaptation of a quadrupole ion trap mass spectrometer (QITMS) to allow for studies of ion-ion reactions in the dilute gas-phase is presented. This system utilizes a dual-source design with electrospray ionization for the injection of multiply charged cations and an atmospheric sampling glow discharge interface (ASGDI) for the production of singly char ed anions. The ASGDI source is mounted 90 degrees to the electrospray interface to facilitate anion injection through a 3 mm hole in the ring electrode. Independent control of the two ion sources allows for selection of the oppositely charged reacting species. Other important instrument capabilities discussed include high mass/high resolution analysis, an ion gate circuit with a variable bipolar output, and use of a TTL pulse for controlling the second (glow-discharge) ion source. Experimental design considerations and representative data from the reactions of multiply charged cations with singly char ed anions including electron transfer (porphyrin systems), proton transfer (peptides and proteins), and adduct formation (anion attachment to various compound classes) are also presented. These data illustrate phenomenologically the reaction types that can be investigated using this Paul-trap-based system. (C) 1997 Elsevier Science B.V. C1 OAK RIDGE NATL LAB, DIV CHEM & ANALYT SCI, OAK RIDGE, TN 37831 USA. RI McLuckey, Scott/B-2203-2009 OI McLuckey, Scott/0000-0002-1648-5570 NR 56 TC 73 Z9 74 U1 0 U2 8 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 1387-3806 EI 1873-2798 J9 INT J MASS SPECTROM JI Int. J. Mass Spectrom. PD MAR PY 1997 VL 162 IS 1-3 BP 89 EP 106 DI 10.1016/S0168-1176(96)04510-7 PG 18 WC Physics, Atomic, Molecular & Chemical; Spectroscopy SC Physics; Spectroscopy GA XD007 UT WOS:A1997XD00700009 ER PT J AU McLuckey, SA Vaidyanathan, G AF McLuckey, SA Vaidyanathan, G TI Charge state effects in the decompositions of single-nucleobase oligonucleotide polyanions SO INTERNATIONAL JOURNAL OF MASS SPECTROMETRY AND ION PROCESSES LA English DT Article DE oligonucleotide; quadrupole ion trap; multiply-charged anion ID TANDEM MASS-SPECTROMETRY; COLLISION-INDUCED DISSOCIATION; ELECTROSPRAY-IONIZATION; ION-TRAP; ENERGY; BASES; OLIGODEOXYNUCLEOTIDES; MONOPHOSPHATES; FRAGMENTATION; DINUCLEOTIDES AB A series of anions derived from electrospray ionization of small oligonucleotides, each consisting of a single nucleobase (adenine, thymine, cytidine or guanine), have been subjected to ion trap tandem mass spectrometry. The data set allows for comparisons of dissociation behavior as functions of parent ion charge, oligomer length, and nucleobase identity. Parent ion charge is seen to play a major role in determining the most important dissociation channels. Dramatic changes in the relative contributions of the various possible dissociation channels are observed from one parent ion charge state to the next. Parent ion charge apparently can alter the relative order of the threshold energies required for the various competitive sequence channels. In addition, the ion trap collisional activation experiment is highly sensitive to differences in the energy requirements for the lowest energy dissociation pathways. Nucleobase identity also is an important factor, with each series of single-nucleobase oligomers showing unique dissociation behavior. For example, poly-T anions show an enhanced tendency for the loss of the 5' thymine relative to the same charge states of oligomers comprised of the other nucleobases whereas the poly-G anions show a lower tendency for the loss of the 5' guanine. Poly-A anions show consecutive nucleobase loss as a reaction channel that competes with those that provide direct sequence information. This tendency increases with increasing oligomer size and charge. (C) 1997 Elsevier Science B.V. RP McLuckey, SA (reprint author), OAK RIDGE NATL LAB,DIV CHEM & ANALYT SCI,OAK RIDGE,TN 37831, USA. RI McLuckey, Scott/B-2203-2009; Vaidyanathan, Ganesan/I-5728-2013 OI McLuckey, Scott/0000-0002-1648-5570; NR 35 TC 30 Z9 30 U1 0 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-1176 J9 INT J MASS SPECTROM JI Int. J. Mass Spectrom. Ion Process. PD MAR PY 1997 VL 162 IS 1-3 BP 1 EP 16 DI 10.1016/S0168-1176(96)04473-4 PG 16 WC Physics, Atomic, Molecular & Chemical; Spectroscopy SC Physics; Spectroscopy GA XD007 UT WOS:A1997XD00700002 ER PT J AU VanBerkel, GJ Zhou, FM Aronson, JT AF VanBerkel, GJ Zhou, FM Aronson, JT TI Changes in bulk solution pH caused by the inherent controlled-current electrolytic process of an electrospray ion source SO INTERNATIONAL JOURNAL OF MASS SPECTROMETRY AND ION PROCESSES LA English DT Article DE electrospray; electrochemistry; pH; water oxidation; diode array detector ID IONIZATION MASS-SPECTRA; CHARGE-STATE DISTRIBUTIONS; SPECTROMETRY; PROTEINS; CELL; DEPENDENCE; INTERFACE; CHEMISTRY; ANALYTES; SALTS AB The redox reactions that take place in the metal capillary of an electrospray ion source to maintain charge balance alter the composition of the initial solution entering the capillary. Data presented here demonstrate that under certain ES conditions, solution pH may be decreased significantly (by at least 4 pH units) as a result of the electrolytic oxidation of water in positive ion mode electrospray-mass spectrometry (ES-MS). Furthermore, it is shown that this pH change can have an affect on the appearance of the ES mass spectrum of an of analyte. An ES ion source in which the pH of an indicator solution exiting the capillary is monitored optically, before the spraying process, is used to demonstrate that electrolytic reactions in positive ion mode ES can decrease the pH of the initial solution. ES-MS studies using bovine heart cytochrome c are used to illustrate the influence of the electrolytically-induced pH change on the gas-phase ion signals for the multiply protonated protein. The magnitude of electrolytically-induced changes in solution pH will be most significant in non-buffered solutions near neutral pH when using metal spray capillaries or metal contacts to solution comprised of difficult to oxidize material (e.g. platinum or gold), Any pH changes will increase in magnitude as the flow rate decreases and/or ES current increases (all other ES parameters constant). Therefore, the potential impact of these redox reactions in ES-MS, if any, will probably be most important in the very low flow rate ES-MS systems (less than or equal to 1.0 mu L min(-1)). (C) 1997 Elsevier Science B.V. C1 UNIV WISCONSIN,DEPT CHEM,EAU CLAIRE,WI 54702. RP VanBerkel, GJ (reprint author), OAK RIDGE NATL LAB,DIV CHEM & ANALYT SCI,OAK RIDGE,TN 37831, USA. NR 40 TC 156 Z9 156 U1 3 U2 22 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-1176 J9 INT J MASS SPECTROM JI Int. J. Mass Spectrom. Ion Process. PD MAR PY 1997 VL 162 IS 1-3 BP 55 EP 67 DI 10.1016/S0168-1176(96)04476-X PG 13 WC Physics, Atomic, Molecular & Chemical; Spectroscopy SC Physics; Spectroscopy GA XD007 UT WOS:A1997XD00700006 ER PT J AU Tang, KQ Smith, RD AF Tang, KQ Smith, RD TI Sensitivity enhancement of electrospray ionization MS for aqueous solutions in the corona-assisted cone-jet mode SO INTERNATIONAL JOURNAL OF MASS SPECTROMETRY AND ION PROCESSES LA English DT Article DE electrospray ionization; corona; biomolecules; sensitivity; cone-jet ID MONODISPERSE WATER DROPLETS; MASS-SPECTROMETRY; GENERATION; PROTEINS; LIQUIDS AB An experimental study is reported of the sensitivity obtained for the electrospray ionization of aqueous solutions in two different cone-jet modes. Six different polypeptides varying in molecular weight from similar to 600 to similar to 12 000 Da were analyzed using a quadrupole mass spectrometer. The sensitivity comparison suggests that more than an order of magnitude enhancement in signal intensity can be achieved in some cases by simply shifting the electrospray operation from the classic cone-jet mode to the corona-assisted cone-jet mode. The sensitivity enhancement in the corona mode spray appears to be independent of both liquid flow rate and sample molecular weight, suggesting that droplet field charging by the corona discharge is the dominant process. Comparison at the field charging limit and the Rayleigh limit indicates that the droplet charge can be effectively increased to the field charging limit for corona mode electrosprays of aqueous solutions at low flow rate. (C) 1997 Elsevier Science B.V. C1 PACIFIC NW LAB, ENVIRONM MOL SCI LAB, RICHLAND, WA 99352 USA. RI Smith, Richard/J-3664-2012 OI Smith, Richard/0000-0002-2381-2349 NR 13 TC 2 Z9 2 U1 1 U2 9 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-1176 J9 INT J MASS SPECTROM JI Int. J. Mass Spectrom. Ion Process. PD MAR PY 1997 VL 162 IS 1-3 BP 69 EP 76 DI 10.1016/S0168-1176(96)04514-4 PG 8 WC Physics, Atomic, Molecular & Chemical; Spectroscopy SC Physics; Spectroscopy GA XD007 UT WOS:A1997XD00700007 ER PT J AU OHair, RAJ McLuckey, SA AF OHair, RAJ McLuckey, SA TI Trimethylsilyl derivatization of nucleic acid anions in the gas phase SO INTERNATIONAL JOURNAL OF MASS SPECTROMETRY AND ION PROCESSES LA English DT Article DE nucleic acid anions; trimethylsilylchloride; ion trap; electrospray ID TANDEM MASS-SPECTROMETRY; COLLISION-INDUCED DISSOCIATION; FAST-ATOM-BOMBARDMENT; CHARGED OLIGONUCLEOTIDE ANIONS; ION-MOLECULE REACTIONS; ELECTROSPRAY IONIZATION; PENTACOORDINATE SILICON; ALKYL-HALIDES; NEGATIVE-IONS; CYTOCHROME-C AB Ion-molecule reactions between nucleic acid anions, [M-nH](n-), formed via electrospray ionization, and trimethylsilylchloride have been investigated in an ion trap mass spectrometer at a helium bath gas pressure of 1 mtorr. Three types of reactions are observed: (i) S(N)2(Si) when n > 1; (ii) adduct formation when n = 1; and (iii) addition followed by elimination of HCl when n = 1 and where an acidic phosphate proton is present (e.g., 5'-pdA). The kinetics of these reactions have been studied for various anions derived from the following deoxyadenosine species: 5'-pdA; 5'-pppdA, 5'-d(AA)-3'; 5'-d(AAA)-3' and 5'-d(AAAA)-3'. The following reactivity order is observed: [M-2H](2-) of 5'-pppdA > [M-2H](2-) of 5'-d(AAA)-3' > [M-3H](3-) of 5'-d(AAAA)-3' > [M-3H + TMS](2-) of 5'-d(AAAA)-3' > [M-2H](2-) of 5'-d(AAAA)-3' > [M-H](-) of 5'-pdA >> [M-H](-) of 5'-d(AA)-3' > [M-H](-) of 5'-d(AAA)-3'. In addition, the collision-induced dissociation reactions of the products of these reactions have been studied. Decomposition reactions are consistent with trimethylsilyl attachment on the phosphodiester linkage(s) in oligonucleotides and on the phosphate moieties of 5'-pdA and 5'-pppdA. Comparison of data acquired for modified and unmodified oligonucleotide anions of the same charge state reveal that TMS modification can significantly alter the favored dissociation channels, giving rise to sequence information. The results suggest that gas phase TMS derivatization of oligonucleotide anions, combined with tandem mass spectrometry, can provide sequence information complementary to that derived from unmodified anions. (C) 1997 Elsevier Science B.V. C1 OAK RIDGE NATL LAB,DIV CHEM & ANALYT SCI,OAK RIDGE,TN 37831. UNIV MELBOURNE,SCH CHEM,PARKVILLE,VIC 3502,AUSTRALIA. RI McLuckey, Scott/B-2203-2009; OI McLuckey, Scott/0000-0002-1648-5570; O'Hair, Richard/0000-0002-8044-0502 NR 75 TC 22 Z9 22 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-1176 J9 INT J MASS SPECTROM JI Int. J. Mass Spectrom. Ion Process. PD MAR PY 1997 VL 162 IS 1-3 BP 183 EP 202 DI 10.1016/S0168-1176(97)00004-9 PG 20 WC Physics, Atomic, Molecular & Chemical; Spectroscopy SC Physics; Spectroscopy GA XD007 UT WOS:A1997XD00700016 ER PT J AU Groch, KM Khan, MA Brooks, AL Saffer, JD AF Groch, KM Khan, MA Brooks, AL Saffer, JD TI Lung cancer response following inhaled radon in the A/J and C57BL/6J mouse SO INTERNATIONAL JOURNAL OF RADIATION BIOLOGY LA English DT Article ID INDUCED PULMONARY ADENOMAS; TUMOR SUSCEPTIBILITY; P53 POLYMORPHISMS; ALPHA-PARTICLES; IN-VITRO; RISK; MICE; MICRONUCLEI; LOCUS; GENES AB A/J and C57BL/6J mice, strains which differ in susceptibility to chemical-induced lung tumours, were examined for differential sensitivity to radon-induced lung cancer. Sixty weeks after exposure to 952 WLR radon (3.34 J h1 m(-3)), no lung tumours were found in the control, sham- (ore dust-) exposed, or radon-exposed C57BL/6J mice. In contrast, each of the A/J groups had a substantial number of tumours. Although there were no differences in overall lung tumour incidence or multiplicity associated with radon and ore dust exposure in A/J mice, distinct differences in tumour size and histopathological appearance were noted. The ratio of lung adenoma-to-carcinoma found in control A/J mice was 10:1, whereas the ratio in ore dust-exposed animals was 10:8 and that in radon-exposed animals was 8:6. Based on these data, particulates appear to modify the promotion-progression of lung cancer in this strain. In addition, the appearance of two very large carcinomas histologically resembling Clara-cell-derived tumours only in the radon-exposed A/J mice and the possibility of a particle-induced killing of target cells in the radon-exposed animals suggests that A/J, but not the C57BL/6J, mice may have genes that modify susceptibility to radon-induced lung cancer. C1 PACIFIC NW NATL LAB,MOL BIOSCI DEPT,RICHLAND,WA 99352. NR 45 TC 9 Z9 9 U1 1 U2 1 PU TAYLOR & FRANCIS LTD PI LONDON PA ONE GUNPOWDER SQUARE, LONDON, ENGLAND EC4A 3DE SN 0955-3002 J9 INT J RADIAT BIOL JI Int. J. Radiat. Biol. PD MAR PY 1997 VL 71 IS 3 BP 301 EP 308 PG 8 WC Biology; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Life Sciences & Biomedicine - Other Topics; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA WR319 UT WOS:A1997WR31900009 PM 9134020 ER PT J AU Curtis, CB McTague, JP Cheney, DW AF Curtis, CB McTague, JP Cheney, DW TI Fixing the national laboratory system SO ISSUES IN SCIENCE AND TECHNOLOGY LA English DT Article RP Curtis, CB (reprint author), US DOE,LAB OPERAT BOARD,WASHINGTON,DC 20585, USA. NR 0 TC 0 Z9 0 U1 1 U2 1 PU NATL ACAD SCIENCES PI WASHINGTON PA 2101 CONSTITUTION AVE NW, WASHINGTON, DC 20418 SN 0748-5492 J9 ISSUES SCI TECHNOL JI Issues Sci. Technol. PD SPR PY 1997 VL 13 IS 3 BP 49 EP 56 PG 8 WC Engineering, Multidisciplinary; Engineering, Industrial; Multidisciplinary Sciences; Social Issues SC Engineering; Science & Technology - Other Topics; Social Issues GA WT382 UT WOS:A1997WT38200027 ER PT J AU Viswanathan, S AF Viswanathan, S TI The effects of convection during solidification processing SO JOM-JOURNAL OF THE MINERALS METALS & MATERIALS SOCIETY LA English DT Editorial Material C1 OAK RIDGE NATL LAB,TMS MAT DESIGN & MFG DIV,SOLIDIFICAT COMM,OAK RIDGE,TN 37831. RP Viswanathan, S (reprint author), OAK RIDGE NATL LAB,DIV MET & CERAM,POB 2008,OAK RIDGE,TN 37831, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU MINERALS METALS MATERIALS SOC PI WARRENDALE PA 420 COMMONWEALTH DR, WARRENDALE, PA 15086 SN 1047-4838 J9 JOM-J MIN MET MAT S JI JOM-J. Miner. Met. Mater. Soc. PD MAR PY 1997 VL 49 IS 3 BP 12 EP 12 DI 10.1007/BF02914648 PG 1 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering; Mineralogy; Mining & Mineral Processing SC Materials Science; Metallurgy & Metallurgical Engineering; Mineralogy; Mining & Mineral Processing GA WN404 UT WOS:A1997WN40400003 ER PT J AU Fenster, L Katz, DF Wyrobek, AJ Pieper, C Rempel, DM Oman, D Swan, SH AF Fenster, L Katz, DF Wyrobek, AJ Pieper, C Rempel, DM Oman, D Swan, SH TI Effects of psychological stress on human semen quality SO JOURNAL OF ANDROLOGY LA English DT Article DE semen quality; semen; psychological stress; sperm count; sperm motion; sperm morphology ID SPERM MORPHOLOGY; INVITRO FERTILIZATION; INFERTILE MEN; LIFE EVENTS; JOB STRAIN; IN-VIVO; SPERMATOZOA; FERTILITY; BEREAVEMENT; PREGNANCY AB We investigated the relationship between psychological stress and sperm concentration, motility, and morphometry in a prospective study of 157 volunteers who were enrolled in a prepaid health plan. We measured psychological job stress and life-event stress by telephone interview. Sperm-kinematic and nuclear-morphometric variables were measured using computer-assisted image analyses. Sperm concentration, percent motility, and semen volume were determined by objective visual methods. We performed multiple linear regression for each semen variable to examine its relationship to stress, controlling for potential confounders. Stress at work and total number of life events were not related to differences in semen quality. However, the recent death of a close family member was associated with a reduction in straight-line velocity (P = 0.002) and percent of progressively motile sperm (P = 0.02); it was also marginally associated with an increase in the fraction of sperm with larger and more tapered nuclei. These findings suggest that the fecundity of men experiencing the stress of a family member's death might be temporarily diminished. C1 DUKE UNIV,DURHAM,NC 27706. LAWRENCE LIVERMORE NATL LAB,BIOL & BIOTECHNOL PROGRAM,LIVERMORE,CA. UNIV CALIF SAN FRANCISCO,SAN FRANCISCO,CA 94143. RP Fenster, L (reprint author), CALIF DEPT HLTH SERV,REPROD EPIDEMIOL SECT,2151 BERKELEY WAY,BERKELEY,CA 94704, USA. RI Rempel, David/E-8424-2013 FU NIEHS NIH HHS [ES03614] NR 60 TC 78 Z9 83 U1 2 U2 5 PU AMER SOC ANDROLOGY, INC PI LAWRENCE PA C/O ALLEN PRESS, INC PO BOX 368, LAWRENCE, KS 66044 SN 0196-3635 J9 J ANDROL JI J. Androl. PD MAR-APR PY 1997 VL 18 IS 2 BP 194 EP 202 PG 9 WC Andrology SC Endocrinology & Metabolism GA WY390 UT WOS:A1997WY39000013 PM 9154514 ER PT J AU Christensen, RM DeTeresa, SJ AF Christensen, RM DeTeresa, SJ TI The kink band mechanism for the compressive failure of fiber composite materials SO JOURNAL OF APPLIED MECHANICS-TRANSACTIONS OF THE ASME LA English DT Article AB A simple strain-based yield/failure criterion for fiber composite materials is incorporated into a kink band analysis of compressive failure. Under realistic conditions of fiber misalignment the analysis predicts compressive failure at load levels about one-fifth Of the ideal value, and with kink band inclinations of about 20 deg. Some parametric variations of the relevant physical variables are given in simple graphical forms, and comparisons are made with newly obtained micrographs of kink bands. C1 STANFORD UNIV,STANFORD,CA 94305. RP Christensen, RM (reprint author), LAWRENCE LIVERMORE NATL LAB,POB 808,LIVERMORE,CA 94550, USA. NR 16 TC 14 Z9 14 U1 0 U2 3 PU ASME-AMER SOC MECHANICAL ENG PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 SN 0021-8936 J9 J APPL MECH-T ASME JI J. Appl. Mech.-Trans. ASME PD MAR PY 1997 VL 64 IS 1 BP 1 EP 6 DI 10.1115/1.2787273 PG 6 WC Mechanics SC Mechanics GA WV163 UT WOS:A1997WV16300001 ER PT J AU Walton, OR AF Walton, OR TI Stress and strain analysis in molecular dynamics simulation of solids SO JOURNAL OF APPLIED MECHANICS-TRANSACTIONS OF THE ASME LA English DT Editorial Material RP Walton, OR (reprint author), LAWRENCE LIVERMORE NATL LAB,POB 808,L-200,LIVERMORE,CA 94550, USA. NR 6 TC 1 Z9 1 U1 0 U2 1 PU ASME-AMER SOC MECHANICAL ENG PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 SN 0021-8936 J9 J APPL MECH-T ASME JI J. Appl. Mech.-Trans. ASME PD MAR PY 1997 VL 64 IS 1 BP 247 EP 247 DI 10.1115/1.2787288 PG 1 WC Mechanics SC Mechanics GA WV163 UT WOS:A1997WV16300040 ER PT J AU Smilowitz, L Jia, QX Yang, X Li, DQ McBranch, D Buelow, SJ Robinson, JM AF Smilowitz, L Jia, QX Yang, X Li, DQ McBranch, D Buelow, SJ Robinson, JM TI Imaging nanometer-thick patterned self-assembled monolayers via second-harmonic generation microscopy SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID OPTICAL 2ND-HARMONIC GENERATION; SURFACE AB We have used the inherent surface sensitivity of second-harmonic generation to develop an instrument for nonlinear optical microscopy of surfaces and interfaces. This optical technique is ideal for imaging nanometer-thick, chromophoric self-assembled monolayers (SAMs), which have been patterned using photolithographic techniques. In this paper, we demonstrate the application of second-harmonic generation microscopy to patterned SAMs of the noncentrosymmetric molecule calixarene and discuss the resolution and sensitivity limits of the technique. (C) 1997 American Institute of Physics. RP Smilowitz, L (reprint author), LOS ALAMOS NATL LAB,CHEM SCI & TECHNOL DIV,POB 1663,LOS ALAMOS,NM 87545, USA. RI Jia, Q. X./C-5194-2008 NR 12 TC 20 Z9 20 U1 0 U2 1 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 MAR 1 PY 1997 VL 81 IS 5 BP 2051 EP 2054 DI 10.1063/1.364284 PG 4 WC Physics, Applied SC Physics GA WK088 UT WOS:A1997WK08800001 ER PT J AU Painter, GS Fu, CL Averill, FW AF Painter, GS Fu, CL Averill, FW TI First-principles atomic cluster study of boron interactions in Ni3Al SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID ELECTRONIC-STRUCTURE; WAVE METHOD; SEGREGATION; SURFACE; SULFUR AB First-principles atomic cluster calculations have been carried out in the local density approximation to understand the segregation behavior and strengthening effects of boron in Ni3Al. The binding energy of boron is calculated in lattice fragment clusters representing the perfect crystal, as well as various defect sites. The agreement between trends in energetics determined for small clusters and periodic supercells indicates the dominant role of boron's interaction with nearest-neighbors of the host. The stereochemical factor underlying boron's preferential bonding to nickel atoms in four-fold planar coordination (i.e., sp(3) hybridization) suggests a mechanism for the baron-effect in Ni3Al: increased cohesion provides a driving force for B segregation to open sites, such as at Ni-enriched grain boundary sites, and the strengthening is a result of strong localized Ni-B covalent bond formation. (C) 1997 American Institute of Physics. C1 JUDSON COLL,ELGIN,IL 60123. RP Painter, GS (reprint author), OAK RIDGE NATL LAB,DIV MET & CERAM,POB 2008,OAK RIDGE,TN 37831, USA. NR 22 TC 3 Z9 3 U1 0 U2 4 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 MAR 1 PY 1997 VL 81 IS 5 BP 2135 EP 2142 DI 10.1063/1.364266 PG 8 WC Physics, Applied SC Physics GA WK088 UT WOS:A1997WK08800015 ER PT J AU Foster, CM Bai, GR Csencsits, R Vetrone, J Jammy, R Wills, LA Carr, E Amano, J AF Foster, CM Bai, GR Csencsits, R Vetrone, J Jammy, R Wills, LA Carr, E Amano, J TI Single-crystal Pb(ZrxTi1-x)O-3 thin films prepared by metal-organic chemical vapor deposition: Systematic compositional variation of electronic and optical properties SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID ELECTRICAL-PROPERTIES; EPITAXIAL-GROWTH; FERROELECTRIC PROPERTIES; MOCVD; HETEROSTRUCTURES; CAPACITORS; FATIGUE; (PB AB Single-crystal thin films of Pb(ZrxTi1-x)O-3 (PZT) covering the full compositional range (0 less than or equal to x less than or equal to 1) were deposited by metal-organic chemical vapor deposition. Epitaxial SrRuO3(001) thin films grown on SrTiO3(001) substrates by rf-magnetron sputter deposition served as template electrode layers to promote the epitaxial growth of PZT. X-ray diffraction, energy-dispersive x-ray spectroscopy, atomic force microscopy, transmission electron microscopy, and optical waveguiding were used to characterize the crystalline structure, composition, surface morphology, microstructure, refractive index, and film thickness of the deposited films. The PZT films were single crystalline for all compositions exhibiting cube-on-cube growth epitaxy with the substrate and showed very high degrees of crystallinity and orientation. The films exhibited typical root mean square surface roughness of similar to 1.0-2.5 nm. For tetragonal films, the surface morphology was dominated by grain tilting resulting from ferroelectric domain formation. We report the systematic compositional variation of the optical, dielectric, polarization, and electronic transport properties of these single-crystalline PZT thin films. We show that the solid-solution phase diagram of the PZT system for thin films differs from the bulk due to epitaxy-induced strains and interfacial defect formation. High values of remanant polarization (30-55 mu C/cm(2)) were observed for ferroelectric compositions in the range of 0.8 less than or equal to x less than or equal to 0.2. Unlike previous studies, the dielectric constant exhibited a clear dependence on composition with values ranging from 225 to 650. The coercive fields decreased with increasing Zr concentration to a minimum of 20 kV/cm for x=0.8. The undoped films exhibited both high resistivity and dielectric-breakdown strength (10(13)-10(14) Omega cm at 100 kV/cm and 300-700 kV/cm, respectively). (C) 1997 American Institute of Physics. C1 HEWLETT PACKARD CORP,HEWLETT PACKARD LABS,PALO ALTO,CA 94304. RP Foster, CM (reprint author), ARGONNE NATL LAB,DIV MAT SCI,9700 S CASS AVE,ARGONNE,IL 60439, USA. NR 58 TC 242 Z9 245 U1 7 U2 69 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 MAR 1 PY 1997 VL 81 IS 5 BP 2349 EP 2357 DI 10.1063/1.364239 PG 9 WC Physics, Applied SC Physics GA WK088 UT WOS:A1997WK08800046 ER PT J AU Lee, JY Xun, LY AF Lee, JY Xun, LY TI Purification and characterization of 2,6-dichloro-p-hydroquinone Chlorohydrolase from Flavobacterium sp. strain ATCC 39723 SO JOURNAL OF BACTERIOLOGY LA English DT Article ID PSEUDOMONAS SP CBS3; PENTACHLOROPHENOL; 2,4,6-TRICHLOROPHENOL; 1,2-DIOXYGENASE; DECHLORINATION; CHLOROPHENOLS; DEHALOGENASE; EXTRACTS; GP1 AB The biochemistry of pentachlorophenol (PCP) degradation by Flavobacterium sp, strain ATCC 39723 has been studied, and two enzymes responsible for the conversion of PCP to 2,6-dichloro-p-hydroquinone (2,6-DiCH) have previously been purified and characterized. In this study, enzymatic activities consuming 2,6-DiCH were identified from the cell extracts of strain ATCC 39723. The enzyme was purified to apparent homogeneity by a purification scheme consisting of seven steps, Gel filtration chromatography showed a native molecular weight of about 40,000, and sodium dodecyl sulfate-polyacrylamide gel electrophoresis revealed a single protein of 42,500 Da. The purified enzyme converted 2,6-DiCH to 6-chlorohydroxyquinol (6-chloro-1,2,4-trihydroxybenzene), which was easily oxidized by molecular oxygen and hard to detect. The end product, 6-chlorohydroxyquinol, was detected only in the presence of a reductase and NADH in the reaction mixture. The enzyme dechlorinated 2,6-DiCH but not 2,5-DiCH. The enzyme required Fe2+ for activity and was severely inhibited by metal chelating agents. The optimal conditions for activity were pH 7.0 and 40 degrees C. The K-m for 2,6-DiCH was 35 mu M, and the k(cat) was 0.011 s(-1). C1 BATTELLE PACIFIC NW NATL LAB,ENVIRONM MICROBIOL GRP,RICHLAND,WA 99352. WASHINGTON STATE UNIV TRICITIES,DEPT MICROBIOL,RICHLAND,WA 99352. NR 25 TC 26 Z9 27 U1 0 U2 0 PU AMER SOC MICROBIOLOGY PI WASHINGTON PA 1325 MASSACHUSETTS AVENUE, NW, WASHINGTON, DC 20005-4171 SN 0021-9193 J9 J BACTERIOL JI J. Bacteriol. PD MAR PY 1997 VL 179 IS 5 BP 1521 EP 1524 PG 4 WC Microbiology SC Microbiology GA WP415 UT WOS:A1997WP41500012 PM 9045808 ER PT J AU ElhaI, J Vepritskiy, A MuroPastor, AM Flores, E Wolk, CP AF ElhaI, J Vepritskiy, A MuroPastor, AM Flores, E Wolk, CP TI Reduction of conjugal transfer efficiency by three restriction activities of Anabaena sp. strain PCC 7120 SO JOURNAL OF BACTERIOLOGY LA English DT Article ID SEQUENCE-SPECIFIC ENDONUCLEASES; SALMONELLA-TYPHIMURIUM LT2; GRAM-POSITIVE BACTERIA; ESCHERICHIA-COLI; CYANOBACTERIUM ANABAENA; PLASMID TRANSFER; DNA RESTRICTION; SACCHAROPOLYSPORA-SPINOSA; NUCLEOTIDE-SEQUENCE; STRUCTURAL GENES AB The efficiency of conjugal transfer of plasmids from Escherichia coli to the cyanobacterium Anabaena sp. sp. strain PCC 7120 mas quantitated as a function of the number of restriction sites for the restriction enzymes carried by the recipient. In addition to the previously recognized isoschizomers of AvaI and AvaII, PCC 7120 was found to possess an isoschizomer of AvaIII. Plasmids modified in E. coli with methylases that protect in vitro against restriction by the three enzymes were transferred with high efficiency, nearly independent of the number of restriction sites on the plasmid, Plasmids left unprotected against one of the three restriction enzymes were transferred with lower efficiencies. For low numbers of sites, the efficiency of conjugal transfer decreased as an exponential function of the number of unprotected sites. The methods presented may be used to increase the efficiency of conjugal transfer into restriction-competent bacteria. C1 MICHIGAN STATE UNIV,US DOE,PLANT RES LAB,E LANSING,MI 48824. UNIV SEVILLA,CSIC,INST BIOQUIM VEGETAL & FOTOSINTESIS,E-41092 SEVILLE,SPAIN. RI Muro-Pastor, Alicia/A-4445-2015; Flores, Enrique/L-2007-2014 OI Muro-Pastor, Alicia/0000-0003-2503-6336; Flores, Enrique/0000-0001-7605-7343 NR 79 TC 162 Z9 170 U1 0 U2 10 PU AMER SOC MICROBIOLOGY PI WASHINGTON PA 1325 MASSACHUSETTS AVENUE, NW, WASHINGTON, DC 20005-4171 SN 0021-9193 J9 J BACTERIOL JI J. Bacteriol. PD MAR PY 1997 VL 179 IS 6 BP 1998 EP 2005 PG 8 WC Microbiology SC Microbiology GA WN161 UT WOS:A1997WN16100022 PM 9068647 ER PT J AU Brenner, JR Marshall, CL Nieman, GC Parks, EK Riley, SJ Ellis, L Tomczyk, NA Winans, RE AF Brenner, JR Marshall, CL Nieman, GC Parks, EK Riley, SJ Ellis, L Tomczyk, NA Winans, RE TI Structural characterization of rhodium-containing hydrodesulfurization (HDS) catalysts derived from a laser vaporization cluster source SO JOURNAL OF CATALYSIS LA English DT Article ID TRANSITION-METAL CLUSTERS; NICKEL CLUSTERS; GAS-PHASE; MAGNETIC-PROPERTIES; ICOSAHEDRAL STRUCTURE; CARBONYL-COMPLEXES; CHEMICAL-REACTIONS; PHOTO-IONIZATION; IRON CLUSTERS; ATOM CLUSTERS AB A series of highly dispersed Rh-based materials have been prepared by deposition of laser-generated gas-phase clusters onto an industrial-grade alumina. While the diameter of the gas-phase metal clusters could be kept at or below 1 nm, the average diameter of the resulting supported Rh particles was always at least 1.5 nm. The reaction of the clusters with either O-2 or C2H4 failed to prevent Rh aggregation on the alumina surface. The addition of O-2 upstream of the Rh target was sufficient to form bulk Rh2O3, whereas downstream addition of O-2 or C2H4 to the Rh clusters was insufficient to form Rh oxide particles. Most of the Rh-containing particles further aggregated during either sulfiding or HDS testing. Nevertheless, the resulting rhodium sulfides were comparable in activity to sulfided, commercial Co-Mo or Ni-Mo catalysts on a per gram of catalyst basis and superior on a per gram of metal basis. At low loadings (0.1 wt%), the cluster-derived catalysts were more hydrogen-efficient than the commercial catalysts. (C) 1997 Academic Press. C1 ARGONNE NATL LAB, DIV CHEM, ARGONNE, IL 60439 USA. MONMOUTH COLL, MONMOUTH, IL USA. ARCO EXPLORAT & PROD TECHNOL, PLANO, TX USA. RI Marshall, Christopher/D-1493-2015 OI Marshall, Christopher/0000-0002-1285-7648 NR 83 TC 8 Z9 8 U1 0 U2 2 PU ACADEMIC PRESS INC ELSEVIER SCIENCE PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0021-9517 J9 J CATAL JI J. Catal. PD MAR PY 1997 VL 166 IS 2 BP 294 EP 305 DI 10.1006/jcat.1997.1522 PG 12 WC Chemistry, Physical; Engineering, Chemical SC Chemistry; Engineering GA WL612 UT WOS:A1997WL61200017 ER PT J AU Hansen, JC Kouri, DJ Hoffman, DK AF Hansen, JC Kouri, DJ Hoffman, DK TI A spreadsheet template for quantum mechanical wavepacket propagation SO JOURNAL OF CHEMICAL EDUCATION LA English DT Article ID SCHRODINGER-EQUATION; SPECTRAL METHOD; WAVE; SCATTERING; DYNAMICS C1 UNIV HOUSTON,DEPT CHEM,HOUSTON,TX 77204. UNIV HOUSTON,DEPT PHYS,HOUSTON,TX 77204. IOWA STATE UNIV SCI & TECHNOL,DEPT CHEM,AMES,IA 50011. IOWA STATE UNIV SCI & TECHNOL,AMES LAB,AMES,IA 50011. RP Hansen, JC (reprint author), SW STATE UNIV,DEPT CHEM,MARSHALL,MN 56258, USA. NR 14 TC 4 Z9 4 U1 0 U2 2 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0021-9584 J9 J CHEM EDUC JI J. Chem. Educ. PD MAR PY 1997 VL 74 IS 3 BP 335 EP 342 PG 8 WC Chemistry, Multidisciplinary; Education, Scientific Disciplines SC Chemistry; Education & Educational Research GA WH165 UT WOS:A1997WH16500031 ER PT J AU Kendrick, B Pack, RT AF Kendrick, B Pack, RT TI Geometric phase effects in the resonance spectrum, state-to-state transition probabilities and bound state spectrum of HO2 SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID QUANTUM REACTIVE SCATTERING; POTENTIAL-ENERGY SURFACE; MANY-BODY EXPANSION; THEORETICAL CHARACTERIZATION; CONICAL INTERSECTION; UNIMOLECULAR DISSOCIATION; COMBUSTION REACTION; LASER SPECTROSCOPY; MOLECULAR-SYSTEMS; IDENTICAL NUCLEI AB The general vector potential (gauge theory) approach for including geometric phase effects in accurate 3D quantum scattering calculations in hyperspherical coordinates is applied to low-energy H+O-2 collisions using our new more accurate DIM (Diatomics In Molecules) potential energy surface. The newly developed hybrid DVR/FBR (Discrete Variable Representation/Finite Basis Representation) numerical technique is used to include geometric phase effects due to the C-2 nu conical intersection in HO2. The scattering results for zero total angular momentum (J=0) computed both with and without the geometric phase show significant differences in the resonance energies and lifetimes. Significant differences in the state-to-state transition probabilities are also observed. The results indicate that geometric phase effects must be included for H+O-2 scattering even at low energies. All 249 vibrational energies of HO2((2)A '') (J = 0) are computed both with and without the geometric phase. Due to the localized nature of the bound state wavefunctions, no geometric phase effects are observed in the vibrational energies even in the high-lying states near dissociation. (C) 1997 American Institute of Physics. RP Kendrick, B (reprint author), LOS ALAMOS NATL LAB,DIV THEORET T12 MSB268,LOS ALAMOS,NM 87545, USA. NR 67 TC 73 Z9 73 U1 0 U2 5 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD MAR 1 PY 1997 VL 106 IS 9 BP 3519 EP 3539 DI 10.1063/1.473449 PG 21 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA WJ575 UT WOS:A1997WJ57500010 ER PT J AU Frink, LJD vanSwol, F AF Frink, LJD vanSwol, F TI A molecular theory for surface forces adhesion measurements SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID DENSITY-FUNCTIONAL THEORY; FLUID-WALL INTERFACE; HARD-SPHERE FLUID; SOLVATION FORCES; CAPILLARY CONDENSATION; COMPUTER-SIMULATION; DRYING TRANSITIONS; ENERGY; APPLICABILITY; ADSORPTION AB Surface forces have been measured by others in undersaturated vapors to determine the adhesive energy of the solid (mica) as well as to probe the limits of the Laplace-Kelvin equation in micropores. The measured pull-off forces are complex requiring an intimate understanding of the underlying oscillatory solvation forces, adsorption, and surface deformation. While the elastic energy of the solid has been taken into account in previous theoretical studies of adhesion, the Laplace-Kelvin assumption of a uniform bulk-like fluid has always been applied. In this paper we present the first application of a modern molecular theory-a nonlocal density functional theory-to the prediction of pull-off forces with the surface forces apparatus. In this theory, the confined fluid is allowed to be nonuniform, and oscillatory solvation forces may be predicted. For rigid surfaces, it is demonstrated that the separation of forces most often used to analyze the surface forces apparatus measurements is highly accurate only when adsorption is properly treated and when the relative pressure is p/p(0)>0.2-0.4. The limiting value of the relative pressure decreases as the strength of the fluid-surface interaction increases. In addition, the range over which the vacuum limit of the solid surface free energy, gamma(s) may be measured is strongly dependent on the strength of various molecular interactions. We predict, as observed in experiments, that the saturation limit of the pull-off force is given by the Laplace pressure alone if there are at least two fluid layers between the surfaces. Finally, we show that using pull-off forces to test the limits of the Laplace-Kelvin theory is misleading because the measurements by design minimize solid-liquid contributions to the total force. (C) 1997 American Institute of Physics. RP Frink, LJD (reprint author), SANDIA NATL LABS,COMPUTAT MAT DEPT 9225,POB 5800,MS-1111,ALBUQUERQUE,NM 87185, USA. NR 26 TC 21 Z9 21 U1 0 U2 1 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD MAR 1 PY 1997 VL 106 IS 9 BP 3782 EP 3791 DI 10.1063/1.473431 PG 10 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA WJ575 UT WOS:A1997WJ57500040 ER PT J AU Fleck, L Beuhler, RJ White, MG AF Fleck, L Beuhler, RJ White, MG TI State-resolved photodesorption of CO from Ag(111): Nonthermal desorption at 1064 nm SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID INDUCED THERMAL-DESORPTION; LASER-INDUCED DESORPTION; ENERGY-DISTRIBUTIONS; SURFACE; RELAXATION; GOLD; NO AB State-resolved measurements of CO molecules desorbed from Ag(111) by 1064 nm radiation have been performed using (VUV+UV) resonant multiphoton ionization. The CO translational and rotational energies are found to be essentially constant over a wide range of 1064 nm laser fluences indicating a non-thermal desorption mechanism. (C) 1997 American Institute of Physics. RP Fleck, L (reprint author), BROOKHAVEN NATL LAB,DEPT CHEM,UPTON,NY 11973, USA. NR 28 TC 4 Z9 4 U1 0 U2 4 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD MAR 1 PY 1997 VL 106 IS 9 BP 3813 EP 3816 DI 10.1063/1.473435 PG 4 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA WJ575 UT WOS:A1997WJ57500044 ER PT J AU Paller, KA Acharya, A Richardson, BC Plaisant, O Shimamura, AP Reed, BR Jagust, WJ AF Paller, KA Acharya, A Richardson, BC Plaisant, O Shimamura, AP Reed, BR Jagust, WJ TI Functional neuroimaging of cortical dysfunction in alcoholic Korsakoff's syndrome SO JOURNAL OF COGNITIVE NEUROSCIENCE LA English DT Article ID POSITRON EMISSION TOMOGRAPHY; REMOTE MEMORY IMPAIRMENT; GLUCOSE METABOLIC-RATE; ALZHEIMERS-DISEASE; DIENCEPHALIC AMNESIA; FRONTAL HYPOMETABOLISM; FLUVOXAMINE TREATMENT; THIAMINE-DEFICIENCY; BRAIN METABOLISM; CEREBRAL ATROPHY AB Many neuropsychological investigations of human memory have focused on the amnesic deficits of alcoholic Korsakoff's syndrome. Structural neuroimaging suggests that the syndrome results from midline diencephalic damage, but functional neuroimaging has the potential to reveal additional neuropathology that may be responsible for cognitive dysfunction. Accordingly, high-resolution positron emission tomography (PET) was used to measure regional cerebral metabolic rates for glucose utilization in five alcoholic Korsakoff patients and nine alcoholic control subjects. Results from a continuous recognition test administered during the radiotracer uptake period indicated that all subjects performed normally with respect to immediate memory, whereas Korsakoff patients demonstrated a marked memory impairment in delayed recognition. PET results from the Korsakoff group showed a widespread decline in glucose metabolism in frontal, parietal, and cingulate regions, suggesting that these functional abnormalities in the cerebral cortex contribute to the memory impairment. Hippocampal glucose metabolism did not differ between the groups. Thus, the evidence did not support the hypothesis that parallel brain dysfunctions are responsible for the similar amnesic symptomatology after hippocampal and diencephalic damage. We hypothesize that the amnesic dysfunction of Korsakoff's syndrome depends on a disruption of thalamocortical interactions that mediate a function critical for normal memory storage. C1 LAWRENCE BERKELEY LAB,BERKELEY,CA. UNIV CALIF DAVIS,DAVIS,CA 95616. UNIV CALIF BERKELEY,BERKELEY,CA 94720. RP Paller, KA (reprint author), NORTHWESTERN UNIV,DEPT PSYCHOL,2029 SHERIDAN RD,EVANSTON,IL 60208, USA. OI Paller, Ken/0000-0003-4415-4143 NR 78 TC 48 Z9 48 U1 0 U2 6 PU M I T PRESS PI CAMBRIDGE PA FIVE CAMBRIDGE CENTER, CAMBRIDGE, MA 02142 SN 0898-929X J9 J COGNITIVE NEUROSCI JI J. Cogn. Neurosci. PD MAR PY 1997 VL 9 IS 2 BP 277 EP 293 DI 10.1162/jocn.1997.9.2.277 PG 17 WC Neurosciences; Psychology, Experimental SC Neurosciences & Neurology; Psychology GA WW374 UT WOS:A1997WW37400008 PM 23962017 ER PT J AU Towle, SN Bargar, JR Brown, GE Parks, GA AF Towle, SN Bargar, JR Brown, GE Parks, GA TI Surface precipitation of Co(II)(aq) on Al2O3 SO JOURNAL OF COLLOID AND INTERFACE SCIENCE LA English DT Article DE surface precipitation; coprecipitation; double hydroxide; cobalt(II); alumina; sorption; polynuclear complex; XAFS; TEM ID ABSORPTION FINE-STRUCTURE; OXIDE-WATER INTERFACE; MULTIPLE-SCATTERING CALCULATIONS; HYDROUS FERRIC-OXIDE; NICKEL-HYDROXIDE; ADSORPTION; SORPTION; COMPLEXES; MODEL; SPECTROSCOPY AB Surface precipitation is an important process in many areas of science and technology, including modeling contaminant segregation from groundwater to solid phases and dispersion of active phases on catalyst supports. XAFS, TEM, and XPS measurements of Co(II) sorbed on Al2O3 demonstrate that surface precipitates have formed from solutions that are undersaturated with respect to any known bulk solid phase. The precipitates have a structure similar to that of Co(OH)(2)(s), but are disordered and have a high concentration of Co vacancies. The data plus thermodynamic reasoning have been used to analyze the plausibility of various models for surface precipitation and to show that for Co(II)/Al2O3 it occurs by forming a double-hydroxide phase containing substrate-derived Al(III) ions. This idea was corroborated by mixing aqueous solutions of Al(III) and Co(II) at the pH and concentration of the sorption samples, forming a stable colloidal precipitate that is less soluble than either Al(OH)(3) or Co(OH)(2). The Co XAFS of this material was similar to that of the sorption samples. Successful quantitative models of metal ion transport in groundwater need to include the possibility of forming ternary and higher order precipitates that include ions derived from sparingly soluble solids. For catalyst impregnation, surface coprecipitation can prevent production of a well-dispersed precursor material. (C) 1997 Academic Press. C1 STANFORD UNIV, DEPT MAT SCI & ENGN, STANFORD, CA 94305 USA. STANFORD UNIV, STANFORD SYNCHROTRON RADIAT LAB, STANFORD, CA 94305 USA. RP Towle, SN (reprint author), STANFORD UNIV, DEPT GEOL & ENVIRONM SCI, STANFORD, CA 94305 USA. NR 58 TC 180 Z9 182 U1 2 U2 43 PU ACADEMIC PRESS INC ELSEVIER SCIENCE PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0021-9797 J9 J COLLOID INTERF SCI JI J. Colloid Interface Sci. PD MAR 1 PY 1997 VL 187 IS 1 BP 62 EP 82 DI 10.1006/jcis.1996.4539 PG 21 WC Chemistry, Physical SC Chemistry GA WN142 UT WOS:A1997WN14200007 ER PT J AU Zhang, XG Basaran, OA AF Zhang, XG Basaran, OA TI Dynamic surface tension effects in impact of a drop with a solid surface SO JOURNAL OF COLLOID AND INTERFACE SCIENCE LA English DT Article DE drop impact; spreading; wetting; dynamic surface tension; surfactant; free surface flow ID FLAT SURFACE; DEFORMATION; BREAKUP AB Recent research on free surface flows in the presence of surface-active species in which a fluid interface undergoes very large deformations, e.g., as in the deformation and breakup of drops in extensional flows under conditions of Stokes flow (Stone, H. A., and Leal, L. G., J. Fluid Mech. 220, 161 (1990)) (19) and the formation of drops from capillaries (Zhang, X., and Basaran, O. A., Phys. Fluids 7, 1184 (1995)) (20) has shown that dynamic surface tension (DST) effects can radically alter the dynamics compared to situations in which the fluid interface is clean. In this paper, we present results of an experimental study that examines the impact with a solid substrate of drops of Newtonian liquids containing two commonly used surfactants. In the experiments, an ultra high-speed video and associated image analysis system is used to monitor the dynamics of the impact process. On account of the extremely large deformations that a drop exhibits and the large-amplitude oscillations that it undergoes upon impacting and spreading on the substrate, DST plays a complex and dominant role in determining the dynamics and the asymptotic state that is approached at large times. A major consequence of the presence of surfactant is that on the one hand its accumulation on the fluid interface reduces the surface tension and thereby enhances the spreading of the drop across the substrate. On the other hand, the non-uniform distribution of surfactant along the fluid interface gives rise to Marangoni stresses that inhibit drop spreading. Given the fact that many liquids used in atomization coating applications ranging from the spraying of agricultural chemicals to painting of substrates contain surfactants and/or other surface-active species, the fundamental results to be reported in this paper have important practical ramifications. (C) 1997 Academic Press. C1 PURDUE UNIV, SCH CHEM ENGN, W LAFAYETTE, IN 47907 USA. RP Zhang, XG (reprint author), OAK RIDGE NATL LAB, DIV CHEM TECHNOL, OAK RIDGE, TN 37831 USA. NR 32 TC 91 Z9 94 U1 3 U2 31 PU ACADEMIC PRESS INC ELSEVIER SCIENCE PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0021-9797 EI 1095-7103 J9 J COLLOID INTERF SCI JI J. Colloid Interface Sci. PD MAR 1 PY 1997 VL 187 IS 1 BP 166 EP 178 DI 10.1006/jcis.1996.4668 PG 13 WC Chemistry, Physical SC Chemistry GA WN142 UT WOS:A1997WN14200017 ER PT J AU Wilson, WD Bisson, CL Schaldach, CM AF Wilson, WD Bisson, CL Schaldach, CM TI Polarization-induced atomic reconfigurations of glycine on a metal surface SO JOURNAL OF COLLOID AND INTERFACE SCIENCE LA English DT Article DE polarization; glycine adsorption; boundary elements; surface reorientation; surface charge; critical phenomenon ID PHOTOELECTRON-SPECTROSCOPY; AMINO-ACIDS; ADSORPTION; COPPER; FORCES AB The atomic reconfigurations of the simplest amino acid, glycine, at a realistic metal surface including a step and real surface charge are calculated. A boundary-element method for determining the polarization-induced binding of molecules to surfaces in the presence of a dielectric is coupled to quantum-chemical calculations of the gas-phase molecule. Enthalpies and potentially derived fractional charges are determined using 6-31G** basis functions and MP2 level of theory for 216 different configurations of glycine. A parameterized model captures the quantum results as a function of bond lengths, angles, and dihedrals (average deviation of <1 kcal/mol). The molecule interacts with a discretized substrate, a face-centered cubic metal slab. The slab is treated as an explicit region of lattice atoms which may include real charge, requiring the boundary conditions and hence the formalism of R. J. Zauhar and R. S. Morgan [J. Mel. Biol. 186, 815 (1985)] to be modified. The results indicate that anionic glycine is bound to a Cu [100] surface by similar to 1.6 eV in the presence of a step of atomic dimensions in a geometric configuration in agreement with the experiments of K. Uvdal, P. Bodo, A. Ihs, B. Liedberg, and W. R. Salaneck [J. Colloid Interface Sci. 140, 207 (1990)]. Neutral glycine and zwitterionic glycine are found to be oriented with their N ends toward a neutral surface in agreement with experiment. These molecules are furthermore found to undergo a critical phenomenon: Their molecular orientation ''flips'' by 180 degrees with the introduction of a small, critical magnitude of real surface charge. (C) 1997 Academic Press. C1 UNIV CALIF BERKELEY, BERKELEY, CA USA. RP SANDIA NATL LABS, ORG 8700, MS 9904, LIVERMORE, CA 94551 USA. NR 29 TC 14 Z9 15 U1 1 U2 2 PU ACADEMIC PRESS INC ELSEVIER SCIENCE PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0021-9797 EI 1095-7103 J9 J COLLOID INTERF SCI JI J. Colloid Interface Sci. PD MAR 1 PY 1997 VL 187 IS 1 BP 201 EP 212 DI 10.1006/jcis.1996.4693 PG 12 WC Chemistry, Physical SC Chemistry GA WN142 UT WOS:A1997WN14200020 ER PT J AU Uras, RA Chang, CT Chen, Y Liu, WK AF Uras, RA Chang, CT Chen, Y Liu, WK TI Multiresolution Reproducing Kernel Particle Methods in acoustics SO JOURNAL OF COMPUTATIONAL ACOUSTICS LA English DT Article; Proceedings Paper CT Mini-Symposium on Computational Structural Acoustics, at the 2nd International Conference on Theoretical and Computational Acoustics (ICTCA2) CY AUG 21-25, 1995 CL HONOLULU, HI ID POSTERIORI AB In the analysis of complex phenomena of acoustic systems, the computational modeling requires special attention in order to give a realistic representation of the physics. As a powerful tool, the finite element method has been widely used in the study of complex systems. In order to capture the important physical phenomena, p-finite elements and/or hp-finite elements are employed. The Reproducing Kernel Particle Methods (RKPM) are emerging as an effective alternative due to the absence of a mesh and the ability to analyze a specific frequency range. In this study, a wavelet particle method based on the multiresolution analysis encountered in signal processing has been developed. The interpolation functions consist of spline functions with a built-in window which permits translation as well as dilation. A variation in the size of the window implies a geometrical refinement and allows the filtering of the desired frequency range. An adaptivity similar to hp-finite element method is obtained through the choice of an optimal dilation parameter. The analysis of the wave equation shows the effectiveness of this approach. The frequency/wave number relationship of the continuum case can be closely simulated by using the reproducing kernel particle methods. A similar methodology is also developed for the Timoshenko beam. C1 NORTHWESTERN UNIV,DEPT MECH ENGN,EVANSTON,IL 60208. RP Uras, RA (reprint author), ARGONNE NATL LAB,REACTOR ENGN DIV,9700 S CASS AVE,ARGONNE,IL 60439, USA. RI Liu, Wing/B-7599-2009 NR 16 TC 29 Z9 33 U1 1 U2 7 PU WORLD SCIENTIFIC PUBL CO PTE LTD PI SINGAPORE PA JOURNAL DEPT PO BOX 128 FARRER ROAD, SINGAPORE 9128, SINGAPORE SN 0218-396X J9 J COMPUT ACOUST JI J. Comput. Acoust. PD MAR PY 1997 VL 5 IS 1 BP 71 EP 94 DI 10.1142/S0218396X9700006X PG 24 WC Acoustics; Mathematics, Interdisciplinary Applications SC Acoustics; Mathematics GA WZ356 UT WOS:A1997WZ35600005 ER PT J AU Hart, WE Istrail, S AF Hart, WE Istrail, S TI Robust proofs of NP-hardness for protein folding: General lattices and energy potentials SO JOURNAL OF COMPUTATIONAL BIOLOGY LA English DT Article DE protein folding; intractability, robustness, lattice models AB This paper addresses the robustness of intractability arguments for simplified models of protein folding that use lattices to discretize the space of conformations that a protein can assume. We present two generalized NP-hardness results. The first concerns the intractability of protein folding independent of the lattice used to define the discrete protein-folding model, We consider a previously studied model and prove that for any reasonable lattice the protein-structure prediction problem is NP-hard. The second hardness result concerns the intractability of protein folding for a class of energy formulas that contains a broad range of mean force potentials whose form is similar to commonly used pair potentials (e,g,, the Lennard-Jones potential), We prove that protein-structure prediction is NP-hard for any energy formula in this class. These are the first robust intractability results that identify sources of computational complexity of protein-structure prediction that transcend particular problem formulations. RP Hart, WE (reprint author), SANDIA NATL LABS,ALGORITHMS & DISCRETE MATH DEPT,POB 5800,ALBUQUERQUE,NM 87185, USA. NR 16 TC 69 Z9 74 U1 0 U2 2 PU MARY ANN LIEBERT INC PUBL PI LARCHMONT PA 2 MADISON AVENUE, LARCHMONT, NY 10538 SN 1066-5277 J9 J COMPUT BIOL JI J. Comput. Biol. PD SPR PY 1997 VL 4 IS 1 BP 1 EP 22 DI 10.1089/cmb.1997.4.1 PG 22 WC Biochemical Research Methods; Biotechnology & Applied Microbiology; Computer Science, Interdisciplinary Applications; Mathematical & Computational Biology; Statistics & Probability SC Biochemistry & Molecular Biology; Biotechnology & Applied Microbiology; Computer Science; Mathematical & Computational Biology; Mathematics GA XA823 UT WOS:A1997XA82300001 PM 9109034 ER PT J AU Warwick, T Ade, H Hitchcock, AP Padmore, H Rightor, EG Tonner, BP AF Warwick, T Ade, H Hitchcock, AP Padmore, H Rightor, EG Tonner, BP TI Soft x-ray spectromicroscopy development for materials science at the advanced light source SO JOURNAL OF ELECTRON SPECTROSCOPY AND RELATED PHENOMENA LA English DT Article DE soft x-ray spectromicroscopy; synchrotron radiation ID CORE EXCITATION SPECTROSCOPY; MICROSCOPY; ELEMENT AB Several third generation synchrotron radiation facilities are now operational, and the high brightness of these photon sources offers new opportunities for X-ray microscopy. Well developed synchrotron radiation spectroscopy techniques are being applied in new instruments capable of imaging the surface of a material with a spatial resolution smaller than 1 mu m. There are two aspects to this. One is to further the field of surface science by exploring the effects of spatial variations across a surface on a scale not previously accessible to X-ray measurements. The other is to open up new analytical techniques in materials science using X-rays on a spatial scale comparable with that of the processes or devices to be studied. The development of the spectromicroscopy program at the Advanced Light Source will employ a variety of instruments, some of which are already operational. Their development and use will be discussed, and recent results will be presented to illustrate their capabilities. (C) 1997 Elsevier Science B.V. C1 N CAROLINA STATE UNIV,RALEIGH,NC 27695. MCMASTER UNIV,HAMILTON,ON L8S 4M1,CANADA. DOW TEXAS POLYMER CTR,FREEPORT,TX 77541. UNIV WISCONSIN,MILWAUKEE,WI 53211. RP Warwick, T (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,BERKELEY,CA 94720, USA. RI Ade, Harald/E-7471-2011 NR 11 TC 33 Z9 33 U1 0 U2 5 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0368-2048 J9 J ELECTRON SPECTROSC JI J. Electron Spectrosc. Relat. Phenom. PD MAR PY 1997 VL 84 IS 1-3 BP 85 EP 98 DI 10.1016/S0368-2048(97)00026-1 PG 14 WC Spectroscopy SC Spectroscopy GA XH468 UT WOS:A1997XH46800008 ER PT J AU Ma, Q Rosenberg, RA Kim, CY Grepstad, J Pianetta, P Droubay, T Dunham, D Tonner, B AF Ma, Q Rosenberg, RA Kim, CY Grepstad, J Pianetta, P Droubay, T Dunham, D Tonner, B TI Comparative magnetic-field imaging, electric-field imaging, and scanning Auger microscopy study of metal-matrix composites SO JOURNAL OF ELECTRON SPECTROSCOPY AND RELATED PHENOMENA LA English DT Article DE X-ray photoelectron microscopy; photoabsorption; MMC; SiC fibre ID FIBER; GRAPHITE; OXYGEN AB X-ray photoelectron emission microscopy (XPEEM) provides valuable chemical information at the micron or submicron level and has been successfully applied to a wide range of materials. We have initiated a study of metal-matrix composites (MMCs) using this technique, aimed at understanding the interfacial interactions that occur between the metal matrix and the ceramic reinforcement. The experiments have been performed on Ti/SiC (fiber) MMCs and SiC fibers. We have found that the method of preparing the sample plays a critical role in understanding the results of the measurements. Samples prepared by polishing and sputtering were examined using an electric-field imaging photoelectron microscope (EFIPM), and fractured samples were studied with a magnetic-field imaging photoelectron microscope (MFIPM). While the EFIPM exhibited exellent elemental contrast and resolution, the data were flawed by artifacts introduced by both the polishing and the sputtering. Although the spatial resolution of the MFIPM was lower than the EFIPM, the ability to study fractured samples greatly facilitated interpretation of the data, which revealed the intrinsic chemical states of the sample. These results will be interpreted in terms of the impact of sample preparation on the application of XPEEM to MMCs and other complex systems. (C) 1997 Elsevier Science B.V. C1 STANFORD SYNCHROTRON RADIAT LAB,SLAC BIN 99,STANFORD,CA 94305. UNIV WISCONSIN,DEPT PHYS,MILWAUKEE,WI 53211. RP Ma, Q (reprint author), ARGONNE NATL LAB,9700 S CASS AVE,ARGONNE,IL 60439, USA. RI Rosenberg, Richard/K-3442-2012; Droubay, Tim/D-5395-2016 OI Droubay, Tim/0000-0002-8821-0322 NR 22 TC 2 Z9 2 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0368-2048 J9 J ELECTRON SPECTROSC JI J. Electron Spectrosc. Relat. Phenom. PD MAR PY 1997 VL 84 IS 1-3 BP 99 EP 107 DI 10.1016/S0368-2048(97)00011-X PG 9 WC Spectroscopy SC Spectroscopy GA XH468 UT WOS:A1997XH46800009 ER PT J AU Droubay, T Mursky, G Tonner, BP AF Droubay, T Mursky, G Tonner, BP TI High-resolution X-ray absorption microspectroscopy of lamellar phases in natural ilmenite SO JOURNAL OF ELECTRON SPECTROSCOPY AND RELATED PHENOMENA LA English DT Article DE X-ray absorption microspectroscopy; X-ray photoelectron emission microscopy; ilmenite; surface chemical analysis ID MAGNETIC CIRCULAR-DICHROISM; TRANSITION-METAL COMPOUNDS; SUM-RULES; SPECTROSCOPY; MN/CU(001); MICROSCOPE; SPECTRA; OXIDES; IRON AB X-ray absorption microscopy is used to study the surface of a mineral, ilmenite. High-quality surface-sensitive micrographs are easily obtained without special sample preparation beyond that usually used in preparing samples for optical microscopy. The X-ray micrographs show an expected lamellar domain structure that has a very strong contrast change at the iron and titanium L-edges. High-resolution spectroscopy from these two different regions reveals fine structure from iron atoms in two different charge states, and titanium in a single phase. A theoretical analysis and curve-fitting procedure is used to determine the precise stoichiometry of the structures in the two phases detected. These results show that quantitative surface chemistry studies can be performed on natural mineral samples using X-ray photoelectron emission microscopy. (C) 1997 Elsevier Science B.V. C1 UNIV WISCONSIN,DEPT PHYS,MILWAUKEE,WI 53201. UNIV WISCONSIN,DEPT GEOSCI,MILWAUKEE,WI 53201. LAWRENCE BERKELEY LAB,BERKELEY,CA. RI Droubay, Tim/D-5395-2016 OI Droubay, Tim/0000-0002-8821-0322 NR 26 TC 18 Z9 18 U1 0 U2 4 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0368-2048 J9 J ELECTRON SPECTROSC JI J. Electron Spectrosc. Relat. Phenom. PD MAR PY 1997 VL 84 IS 1-3 BP 159 EP 169 DI 10.1016/S0368-2048(97)00018-2 PG 11 WC Spectroscopy SC Spectroscopy GA XH468 UT WOS:A1997XH46800014 ER PT J AU Gardner, JA Rao, MV Tian, YL Holland, OW Roth, EG Chi, PH Ahmad, I AF Gardner, JA Rao, MV Tian, YL Holland, OW Roth, EG Chi, PH Ahmad, I TI Rapid thermal annealing of ion implanted 6H-SIC by microwave processing SO JOURNAL OF ELECTRONIC MATERIALS LA English DT Article; Proceedings Paper CT 38th Electronic Materials Conference (EMC) CY JUN 26-28, 1996 CL UNIV OF CALIF AT SANTA BARBARA, SANTA BARBARA, CA HO UNIV OF CALIF AT SANTA BARBARA DE implantation; microwave annealing; rapid thermal processing; silicon carbide AB Rapid thermal processing utilizing microwave energy has been used to anneal N, P, and Al ion-implanted 6H-SiC. The microwaves raise the temperature of the sample at a rate of 200 degrees C/min vs 10 degrees C/min for conventional ceramic furnace annealing. Samples were annealed in the temperature range of 1400-1700 degrees C for 2-10 min. The implanted/annealed samples were characterized using van der Pauw Hall, Rutherford backscattering, and secondary ion mass spectrometry. For a given annealing temperature, the characteristics of the microwave annealed material are similar to those of conventional furnace anneals despite the difference in cycle time. C1 OAK RIDGE NATL LAB,OAK RIDGE,TN 37831. NIST,GAITHERSBURG,MD 20899. FM TECHNOL,FAIRFAX,VA 22032. RP Gardner, JA (reprint author), GEORGE MASON UNIV,DEPT ELECT & COMP ENGN,FAIRFAX,VA 22030, USA. NR 17 TC 19 Z9 20 U1 0 U2 2 PU MINERALS METALS MATERIALS SOC PI WARRENDALE PA 420 COMMONWEALTH DR, WARRENDALE, PA 15086 SN 0361-5235 J9 J ELECTRON MATER JI J. Electron. Mater. PD MAR PY 1997 VL 26 IS 3 BP 144 EP 150 DI 10.1007/s11664-997-0141-5 PG 7 WC Engineering, Electrical & Electronic; Materials Science, Multidisciplinary; Physics, Applied SC Engineering; Materials Science; Physics GA WN137 UT WOS:A1997WN13700009 ER PT J AU Edwards, A Rao, MV Molnar, B Wickenden, AE Holland, OW Chi, PH AF Edwards, A Rao, MV Molnar, B Wickenden, AE Holland, OW Chi, PH TI Ion implantation doping of OMCVD grown GaN SO JOURNAL OF ELECTRONIC MATERIALS LA English DT Article; Proceedings Paper CT 38th Electronic Materials Conference (EMC) CY JUN 26-28, 1996 CL UNIV OF CALIF AT SANTA BARBARA, SANTA BARBARA, CA HO UNIV OF CALIF AT SANTA BARBARA DE annealing; gallium nitride; ion implantation; Rutherford back scattering ID MOLECULAR-BEAM EPITAXY; THERMAL-STABILITY; GALLIUM NITRIDE; FILMS; DIFFUSION; DOPANTS; INP; MG AB Doping by ion implantation using Si, O, Mg, and Ca has been studied in single crystal semi-insulating and n-type GaN grown on a-sapphire substrates. The nand p-type dopants used in this study are Si and O; Mg and Ca, respectively. Room temperature activation of Si and O donors has been achieved after 1150 degrees C annealing for 120 s. The activation of Mg and Ca accepters is too low to measure at both room temperature and 300 degrees C. Using higher doses to achieve a measurable p-type conduction increases the amount of damage created by the implantation. Rutherford back scattering measurements on this material indicate that the damage is still present even after the maximum possible heat treatment. Secondary ion mass spectrometry measurements have indicated a redistribution in the measured profiles of Mg due to annealing. C1 USN,RES LAB,WASHINGTON,DC 20375. OAK RIDGE NATL LAB,OAK RIDGE,TN 37831. NIST,GAITHERSBURG,MD 20899. RP Edwards, A (reprint author), GEORGE MASON UNIV,DEPT ELECT & COMP ENGN,FAIRFAX,VA 22030, USA. NR 34 TC 12 Z9 12 U1 1 U2 9 PU MINERALS METALS MATERIALS SOC PI WARRENDALE PA 420 COMMONWEALTH DR, WARRENDALE, PA 15086 SN 0361-5235 J9 J ELECTRON MATER JI J. Electron. Mater. PD MAR PY 1997 VL 26 IS 3 BP 334 EP 339 DI 10.1007/s11664-997-0174-9 PG 6 WC Engineering, Electrical & Electronic; Materials Science, Multidisciplinary; Physics, Applied SC Engineering; Materials Science; Physics GA WN137 UT WOS:A1997WN13700042 ER PT J AU Janus, MC Richards, GA Gemmen, RS Johnson, EK AF Janus, MC Richards, GA Gemmen, RS Johnson, EK TI An analytical approach to understanding the ''pressure gain'' combustor SO JOURNAL OF ENERGY RESOURCES TECHNOLOGY-TRANSACTIONS OF THE ASME LA English DT Article ID TURBINE AB Although pulse combustion has been successfully utilized in various commercial applications, one potential application yet to reach the market is the pressure gain gas turbine (PGGT). A PGGT would incorporate a pulse combustor rather than the typical steady-flow combustor to increase system efficiency and decrease pollutant emissions. The distinctive advantage of pulse combustion is its ability to achieve a stagnation ''pressure gain'' from inlet to exit A primary concern with pressure gain combustion development, however, is the lack of understanding as to how a combustor should be designed to achieve a pressure gain. While significant progress has been made in understanding the fundamental controlling physics of pulse combustor operation, little research has been aimed at understanding and predicting whether a given system will produce pressure gain. The following paper proposes a simple framework which helps to explain how a pulse combustor achieves a stagnation pressure gain from inlet to exit. The premise behind the framework is that pressure gain can be achieved by closely approximating a constant volume combustion process, and a constant volume combustion process is closely approximated by matching the resonant and operating frequencies of the system. The framework is primarily based upon results from a one-dimensional method-of-characteristics model. RP Janus, MC (reprint author), US DOE,MORGANTOWN ENERGY TECHNOL CTR,POB 880,3610 COLLINS FERRY RD,MORGANTOWN,WV 26505, USA. NR 25 TC 2 Z9 2 U1 1 U2 3 PU ASME-AMER SOC MECHANICAL ENG PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 SN 0195-0738 J9 J ENERG RESOUR-ASME JI J. Energy Resour. Technol.-Trans. ASME PD MAR PY 1997 VL 119 IS 1 BP 49 EP 54 DI 10.1115/1.2794222 PG 6 WC Energy & Fuels SC Energy & Fuels GA WT416 UT WOS:A1997WT41600008 ER PT J AU Ringelberg, DB Stair, JO Almeida, J Norby, RJ ONeill, EG White, DC AF Ringelberg, DB Stair, JO Almeida, J Norby, RJ ONeill, EG White, DC TI Consequences of rising atmospheric carbon dioxide levels for the belowground microbiota associated with white oak SO JOURNAL OF ENVIRONMENTAL QUALITY LA English DT Article ID POLY-BETA-HYDROXYBUTYRATE; FATTY-ACIDS; MYCORRHIZAL COLONIZATION; PLANT-RESPONSES; ELEVATED CO2; QUERCUS-ALBA; GROWTH; BIOMASS; RHIZOSPHERE; ENRICHMENT AB The consequences for belowground microbiota under conditions of rising atmospheric CO2 are largely unknown. In this research we examined the microbiota associated with white oak (Quercus alba L.). It was our hypothesis that an increase in CO2 level would induce a change in the rhizosphere-associated microbial abundance and community composition. To provide an in situ estimation of microbial abundance and community composition, ester-linked polar lipid fatty acid (PLFA) technology was utilized. This technology, based on the quantitative measurement of membrane lipid fatty acids, has been utilized in the accurate identification and description of bacterial isolates and communities. Initial experiments demonstrated that a clear distinction in lipid patterns and microbial biomass existed between sterile roots and those of roots containing an associated viable microbiota. Statistical approaches were then used to determine what differences existed between individual PLFA and PLFA patterns obtained from white oak fine roots and bulk soils. An analysis of variance (ANOVA) showed significant differences to exist in the relative percentages of individual prokaryotic PLFA collected under ambient vs. elevated CO2 and between those associated with fine roots and bulk soils. Multivariate statistics showed distinct differences in the patterns of prokaryotic PLFA detected in the rhizosphere vs. the surrounding bulk soil, but did not identify differences related to elevated CO2 exposures. An artificial neural network recognized PLFA patterns unique to three different CO2 exposures: similar to 35, similar to 50, and similar to 65 Pa. Results of the three statistical tests were viewed as supportive of the hypothesis describing significant differences in individual PLFA and patterns of PLFA as a result of elevated CO2 exposure. C1 UNIV TENNESSEE,CTR ENVIRONM BIOTECHNOL,KNOXVILLE,TN 37932. OAK RIDGE NATL LAB,DIV ENVIRONM SCI,OAK RIDGE,TN 37831. RP Ringelberg, DB (reprint author), DYNTEL CORP,WATERWAYS EXPT STN,3909 HALLS FERRY RD,VICKSBURG,MS 39180, USA. RI Norby, Richard/C-1773-2012 OI Norby, Richard/0000-0002-0238-9828 NR 36 TC 47 Z9 50 U1 0 U2 19 PU AMER SOC AGRONOMY PI MADISON PA 677 S SEGOE RD, MADISON, WI 53711 SN 0047-2425 J9 J ENVIRON QUAL JI J. Environ. Qual. PD MAR-APR PY 1997 VL 26 IS 2 BP 495 EP 503 PG 9 WC Environmental Sciences SC Environmental Sciences & Ecology GA WP039 UT WOS:A1997WP03900021 ER PT J AU Pasko, VP Inan, US Bell, TF Taranenko, YN AF Pasko, VP Inan, US Bell, TF Taranenko, YN TI Sprites produced by quasi-electrostatic heating and ionization in the lower ionosphere SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID NIGHTTIME D-REGION; LOW-LIGHT VIDEO; RED-SPRITES; ELECTROMAGNETIC PULSES; LUMINOUS STRUCTURES; OPTICAL-EMISSIONS; AIRCRAFT CAMPAIGN; ELECTRIC-FIELDS; VLF SIGNATURES; BLUE JETS AB Quasi-electrostatic (QE) fields that temporarily exist at high altitudes following the sudden removal (e.g.; by a lightning discharge) of thundercloud charge at low altitudes lead to ambient electron heating (up to similar to 5 eV average energy), ionization of neutrals, and excitation of optical emissions in the mesosphere/lower ionosphere. Model calculations predict the possibility of significant (several orders of magnitude) modification of the lower ionospheric conductivity in the form of depletions of electron density due to dissociative attachment to O-2 molecules and/or in the form of enhancements of electron density due to breakdown ionization. Results indicate that the optical emission intensities of the 1st positive band of N-2 corresponding to fast (similar to 1 ms) removal of 100-300 C of thundercloud charge from 10 km altitude are in good agreement with observations of the upper part (''head'' and ''hair'' [Sentman et al., 1995]) of the sprites. The typical region of brightest optical emission has horizontal and vertical dimensions similar to 10 km, centered at altitudes 70 km and is interpreted as the head of the sprite. The model also shows the formation of low intensity glow (''hair'') above this region due to the excitation of optical emissions at altitudes similar to 85 km during similar to 500 mu s at the initial stage of the lightning discharge. Comparison of the optical emission intensities of the 1st and 2nd positive bands of N-2, Meinel and 1st negative bands of N-2(+), and 1st negative band of O-2(+) demonstrates that the Ist positive band of N-2 is the dominating optical emission in the altitude range around similar to 70 km, which accounts for the observed red color of sprites, in excellent agreement with recent spectroscopic observations of sprites. Results indicate that the optical emission levels are predominantly defined by the lightning discharge duration and the conductivity properties of the atmosphere/lower ionosphere (i.e., relaxation time of electric field in the conducting medium). The model demonstrates that for low ambient conductivities the lightning discharge duration can be significantly extended with no loss in production of optical emissions. The peak intensity of optical emissions is determined primarily by the value of the removed thundercloud charge and its altitude. The preexisting inhomogeneities in the mesospheric conductivity and the neutral density may contribute to the formation of a vertically striated fine structure of sprites and explain why sprites often repeatedly occur in the same place in the sky as well as their clustering. Comparison of the model results for different types of lightning discharges indicates that positive cloud to ground discharges lead to the largest electric fields and optical emissions at ionospheric altitudes since they are associated with the removal of larger amounts of charge from higher altitudes. C1 LOS ALAMOS NATL LAB,LOS ALAMOS,NM. RP Pasko, VP (reprint author), STANFORD UNIV,STAR LAB,STANFORD,CA 94305, USA. RI Pasko, Victor/S-6024-2016 NR 89 TC 288 Z9 297 U1 0 U2 11 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 J9 J GEOPHYS RES-SPACE JI J. Geophys. Res-Space Phys. PD MAR 1 PY 1997 VL 102 IS A3 BP 4529 EP 4561 DI 10.1029/96JA03528 PG 33 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA WL464 UT WOS:A1997WL46400005 ER PT J AU RousselDupre, RA Blanc, E AF RousselDupre, RA Blanc, E TI HF echoes from ionization potentially produced by high-altitude discharges SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID ELECTROMAGNETIC PULSES; LOWER IONOSPHERE; AIR BREAKDOWN; STRATOSPHERE; THUNDERSTORM; FLASHES AB The presence of ionization associated with high-altitude discharges has been detected using an HF radar operating at 2.2, 2.5, and 2.8 MHz. On several occasions, oblique echoes lasting several hundred ms at night and 1 --> 10 s during the day were observed. The echoes turned on in several interpulse times of 70 ms and were generally correlated with strong lightning activity prior to onset. The angles of arrival of sferics detected at three goniometer stations were used to determine the distance to thunderstorms. The data are consistent with specular reflections from columns of ionization produced at 55-65 km altitude and having minimum electron densities of 6 x 10(4) - 10(5) cm(-3). The source of the ionization is believed to be High-altitude discharges. C1 CEA,LAB DETECT & GEOPHYS,BRUYERES CHATEL,FRANCE. RP RousselDupre, RA (reprint author), LOS ALAMOS NATL LAB,POB 1663,NIS-1,MS D466,LOS ALAMOS,NM 87545, USA. RI Blanc, Elisabeth/D-3890-2009 OI Blanc, Elisabeth/0000-0002-1599-4736 NR 46 TC 21 Z9 21 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 J9 J GEOPHYS RES-SPACE JI J. Geophys. Res-Space Phys. PD MAR 1 PY 1997 VL 102 IS A3 BP 4613 EP 4622 DI 10.1029/96JA02354 PG 10 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA WL464 UT WOS:A1997WL46400010 ER PT J AU Crooker, NU Lazarus, AJ Phillips, JL Steinberg, JT Szabo, A Lepping, RP Smith, EJ AF Crooker, NU Lazarus, AJ Phillips, JL Steinberg, JT Szabo, A Lepping, RP Smith, EJ TI Coronal streamer belt asymmetries and seasonal solar wind variations deduced from Wind and Ulysses data SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID HELIOSPHERIC CURRENT SHEET; SPACECRAFT OBSERVATIONS; HELIOGRAPHIC LATITUDES; SECTOR STRUCTURE; SPEED; PARAMETERS; MINIMUM; 1-AU; SCAN AB Solar wind measurements from Wind during March 1995 are combined with those from Ulysses' fast latitude scan to construct a map of the streamer belt. On the timescale of coronal change, the map is nearly a snapshot view of solar wind speed contours threaded by the trace of the heliospheric current sheet (HCS) in the +/-30 degrees heliolatitude range. The combined set of HCS crossings agrees remarkably well with the neutral line on the corresponding classical source surface map. The neutral line is displaced slightly southward, with latitudinal excursions ranging from -22 degrees to +17 degrees. In contrast, a line running through the locus of minimum speed, although following the general trend of the neutral line, is confined to lower latitudes and displaced slightly northward, ranging from -4 degrees to +13 degrees. The separation between the minimum speed locus and the neutral line marking the HCS was unexpected. Possible interplanetary and solar origins are discussed. The deduced asymmetries as well as coronal change between December and March were responsible for solar wind variations at Earth that mimicked the previously reported seasonal variation in Wind data and would have masked it had the observations been taken during September equinox. C1 MIT,CTR SPACE RES,CAMBRIDGE,MA 02139. LOS ALAMOS NATL LAB,LOS ALAMOS,NM. NASA,GODDARD SPACE FLIGHT CTR,EXTRATERR PHYS LAB,GREENBELT,MD 20771. CALTECH,JET PROP LAB,PASADENA,CA. RP Crooker, NU (reprint author), BOSTON UNIV,CTR SPACE PHYS,725 COMMONWEALTH AVE,BOSTON,MA 02215, USA. NR 31 TC 38 Z9 38 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 J9 J GEOPHYS RES-SPACE JI J. Geophys. Res-Space Phys. PD MAR 1 PY 1997 VL 102 IS A3 BP 4673 EP 4679 DI 10.1029/96JA03681 PG 7 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA WL464 UT WOS:A1997WL46400016 ER PT J AU Tsurutani, BT Arballo, JK Goldstein, BE Ho, CM Lakhina, GS Smith, EJ CornilleauWehrlin, N Prange, R Lin, N Kellogg, P Phillips, JL Balogh, A Krupp, N Kane, M AF Tsurutani, BT Arballo, JK Goldstein, BE Ho, CM Lakhina, GS Smith, EJ CornilleauWehrlin, N Prange, R Lin, N Kellogg, P Phillips, JL Balogh, A Krupp, N Kane, M TI Plasma wave characteristics of the Jovian magnetopause boundary layer: Relationship to the Jovian aurora? SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID ION-CYCLOTRON INSTABILITY; HUBBLE-SPACE-TELESCOPE; DIFFUSION-PROCESSES; ULYSSES ENCOUNTER; SOLAR-WIND; UV AURORA; JUPITER; MAGNETOSPHERE; TURBULENCE; PRECIPITATION AB The Jovian magnetopause boundary layer (BL) plasma wave spectra from 10(-3) to 10(2) Hz have been measured for the first time. For one intense event the magnetic (B') and electric (E') spectra were 2 x 10(-4) f(2.4) nT(2)/Hz and 4 x 10(-9) f(2.4) V-2/m(2) Hz, respectively. Although no measurable wave amplitudes were detected above the electron gyrofrequency, similar to 140 Hz, this finding may be due to the low signal strength characteristic of this region; The B'/E' ratio is relatively frequency independent. It is possible that waves are obliquely propagating whistler mode waves. The B' and E' spectra are broadband with no obvious spectral peaks. The waves are sufficiently intense to cause cross-field diffusion of magnetosheath plasma to create the BL itself. A Jovian BL thickness of 10,700 km is predicted, which is consistent with past in situ measurements. The Jovian boundary layer wave properties are quite similar to the BL waves at Earth (however, the Jovian waves are orders of magnitude less intense). It appears that the solar wind/magnetosphere dynamos at the two planets are similar enough to be consistent with a common wave generation mechanism. The predicted ionospheric latitudinal width of the BL of similar to 100-200 km is quite similar to the Jovian auroral high-latitude ring measured by Hubble. The location of the BL at and inside the foot point of the last closed field line may place the boundary layer and the aurora on approximately the same magnetic field lines. The Jovian BL waves are sufficiently intense to cause strong pitch angle diffusion for <5-keV electrons and 1-keV to 1-MeV protons. The estimated energy precipitation rate from this interaction <1 erg cm(-2) s(-1), sufficient for a weak high-latitude auroral ring. This intensity is 2 to 3 orders of magnitude too low to cause the main aurora ring, however. If it is found that this main aurora maps into the boundary layer, then other mechanisms such as (ionospheric) double layers must be responsible for the particle energization and precipitation. C1 UNIV VERSAILLES,CTR ETUDE ENVIRONM TERRESTRE & PLANETAIRES,VERSAILLES,FRANCE. UNIV PARIS 06,INST ASTROPHYS SPATIALE,ORSAY,FRANCE. UNIV MINNESOTA,SCH PHYS & ASTRON,MINNEAPOLIS,MN. LOS ALAMOS NATL LAB,LOS ALAMOS,NM. UNIV LONDON IMPERIAL COLL SCI TECHNOL & MED,BLACKETT LAB,LONDON,ENGLAND. MAX PLANCK INST AERON,KATLENBURG DUHM,GERMANY. JOHNS HOPKINS UNIV,APPL PHYS LAB,LAUREL,MD. RP Tsurutani, BT (reprint author), CALTECH,JET PROP LAB,4800 OAK GROVE DR,PASADENA,CA 91109, USA. RI Lakhina, Gurbax /C-9295-2012; OI Lakhina, Gurbax /0000-0002-8956-486X NR 49 TC 13 Z9 13 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 J9 J GEOPHYS RES-SPACE JI J. Geophys. Res-Space Phys. PD MAR 1 PY 1997 VL 102 IS A3 BP 4751 EP 4764 DI 10.1029/96JA02785 PG 14 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA WL464 UT WOS:A1997WL46400024 ER PT J AU Weiss, LA Thomsen, MF Reeves, GD McComas, DJ AF Weiss, LA Thomsen, MF Reeves, GD McComas, DJ TI An examination of the Tsyganenko (T89a) field model using a database of two-satellite magnetic conjunctions SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID MAGNETOSPHERIC PLASMA ANALYZER; SPACECRAFT; SHEET AB We use a database of magnetic conjunctions between Defense Meteorological Satellite Program (DMSP) and geosynchronous satellites to (1) evaluate the mapping of the Tsyganenko T89a magnetic field model between the ionosphere and geosynchronous orbit and (2) test the ability of different magnetospheric parameters to identify the T89a stretching level (parameterized by Kp = 0-5) which comes closest to reproducing the observed conjunctions. The database, covering a range of magnetospheric activity, local times, and season, was compiled using 4 months of plasma electron data from two geosynchronous satellites and three low-altitude DMSP satellites. The conjunctions were determined using an automated spectral comparison and selection technique which identified intervals of close spectral matching between the distributions observed at the two satellites. Comparison of the observed conjunctions with the closest T89a mappings show that the observed range of field line stretch at geosynchronous orbit (in the dawn and dusk local time sectors) is generally greater than that allowed by T89a. In nearly half the cases, the observed mappings are less stretched than the least-stretched (Kp = 0) Version of T89a. We found that none of the magnetospheric parameters we evaluated (Kp, AE, Dst, the Auroral Boundary Index (ABI), or the inclination of the magnetic field at geosynchronous orbit) could provide a unique pointer to the most appropriate T89a stretching level for every conjunction. However, both the tilt of the field at geosynchronous orbit and the ABI show a strong correlation with the observed degree of field stretch and indices based on these parameters are thus promising candidates for incorporation into future models. RP Weiss, LA (reprint author), LOS ALAMOS NATL LAB,NIS 1,MD D466,POB 1663,LOS ALAMOS,NM 87545, USA. RI Reeves, Geoffrey/E-8101-2011 OI Reeves, Geoffrey/0000-0002-7985-8098 NR 25 TC 10 Z9 10 U1 0 U2 3 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 J9 J GEOPHYS RES-SPACE JI J. Geophys. Res-Space Phys. PD MAR 1 PY 1997 VL 102 IS A3 BP 4911 EP 4918 DI 10.1029/96JA02876 PG 8 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA WL464 UT WOS:A1997WL46400035 ER PT J AU Mercado, JA Trigo, MM Reid, MS Valpuesta, V Quesada, MA AF Mercado, JA Trigo, MM Reid, MS Valpuesta, V Quesada, MA TI Effects of low temperature on pepper pollen morphology and fertility: Evidence of cold induced exine alterations SO JOURNAL OF HORTICULTURAL SCIENCE LA English DT Article ID CAPSICUM-ANNUUM-L; SWEET-PEPPER; FRUIT-SET; SIZE; GROWTH; SHAPE AB The effects of low night temperatures on pollen viability and pollen grain morphology were investigated in bell pepper (Capsicum annuum, L.) commercial hybrids 'Latino' and 'Novi'. Night temperatures of 10 and 15 degrees C decreased pollen viability, estimated by an in vitro assay and acetocarmine staining, and by decreased seed number per fruit. At anthesis, in a separate experiment, pollen grains that developed at low temperature (25/14 degrees C, day/night) were smaller and appeared aggregated and shrunken with a differently sculptured exine which was thinner than the pollen exine developed at the 30/20 degrees C temperature regime. The results obtained when a 10 degrees C night-temperature treatment was applied to plants grown at 30/20 degrees C with flower buds of different diameters, indicated that meiosis and the young microspore stage were affected. However, the later phases of microspore development and pollen maturation were not affected by the same temperature treatments. C1 UNIV MALAGA,DEPT BIOL VEGETAL,E-29071 MALAGA,SPAIN. LAWRENCE LIVERMORE NATL LAB,DEPT ENVIRONM HORT,DAVIS,CA 95616. RP Mercado, JA (reprint author), UNIV MALAGA,DEPT BIOQUIM & BIOL MOL,E-29071 MALAGA,SPAIN. RI Mercado, Jose/G-5149-2011; TRIGO, M. MAR/K-7886-2014; OI TRIGO, M. MAR/0000-0002-6571-5205; Mercado Carmona, Jose Angel/0000-0003-4351-6261; Quesada Felice, Miguel Angel/0000-0002-1720-4005 NR 34 TC 24 Z9 24 U1 1 U2 8 PU HEADLEY BROTHERS LTD PI ASHFORD PA INVICTA PRESS, ASHFORD, KENT, ENGLAND TN24 8HH SN 0022-1589 J9 J HORTIC SCI JI J. Horticult. Sci. PD MAR PY 1997 VL 72 IS 2 BP 317 EP 326 PG 10 WC Horticulture SC Agriculture GA WR345 UT WOS:A1997WR34500016 ER PT J AU Meisel, D AF Meisel, D TI Pulse radiolysis in imaging sciences: Silver, silver halides, and other clusters SO JOURNAL OF IMAGING SCIENCE AND TECHNOLOGY LA English DT Article; Proceedings Paper CT Symposium on Physical Methods for the Characterization of Imaging Materials and Processes, at the 49th Annual Meeting of IS&T CY MAY 20, 1996 CL MINNEAPOLIS, MN SP IS&T ID AQUEOUS-SOLUTION; COLLOIDAL SILVER; OLIGOMER CLUSTERS; REDOX POTENTIALS; TRANSIENT ABSORPTION; HYDRATED ELECTRON; RATE CONSTANTS; PARTICLES; AGGREGATION; GROWTH AB Pulse radiolysis has been utilized over the last three decades to study a variety of physical and chemical systems, including those relevant to imaging processes. In this overview, we outline the similarities between photolysis and radiolysis and highlight the differences. In particular, we focus on the time-resolved variants of the two disciplines: pulse radiolysis versus gash photolysis. The strength (and weakness) of the radiolytic techniques is their nonspecificity; the energy is always absorbed by the majority medium, the solvent and not the solute. Therefore, once thermalization occurs (much less than 1 ps), the primary reactive intermediates are the same regardless of the solute. From this time on, the chemistry that follows is the chemistry of radicals, radical ions, excited states, metal ions at unstable oxidation state, and other reactive molecular products such as metallic and semiconductor clusters. Thus, radiation chemistry principles that were developed for one discipline are easily transportable to another. The pulse radiolysis technique with a wide arsenal of detection methodologies is currently used to identify short-lived intermediates and to determine their kinetic and thermodynamic properties. Together these studies provide mechanistic insight into the? behavior of many chemical and physical systems. We demonstrate the utility of the approach in several areas of interest to imaging sciences, in particular, clustering of silver atoms, growth of silver halides, and medium effects on these systems. Other systems of relevance to imaging sciences include reactivity and redox potentials of quinone and one-electron reduced/oxidized dyes. RP Meisel, D (reprint author), ARGONNE NATL LAB, DIV CHEM, 9700 S CASS AVE, ARGONNE, IL 60439 USA. NR 65 TC 1 Z9 1 U1 1 U2 3 PU I S & T - SOC IMAGING SCIENCE TECHNOLOGY PI SPRINGFIELD PA 7003 KILWORTH LANE, SPRINGFIELD, VA 22151 USA SN 1062-3701 J9 J IMAGING SCI TECHN JI J. Imaging Sci. Technol. PD MAR-APR PY 1997 VL 41 IS 2 BP 112 EP 117 PG 6 WC Imaging Science & Photographic Technology SC Imaging Science & Photographic Technology GA XV694 UT WOS:A1997XV69400004 ER PT J AU Gakh, AA Sumpter, BG Noid, DW Sachleben, RA Moyer, BA AF Gakh, AA Sumpter, BG Noid, DW Sachleben, RA Moyer, BA TI Prediction of complexation properties of crown ethers using computational neural networks SO JOURNAL OF INCLUSION PHENOMENA AND MOLECULAR RECOGNITION IN CHEMISTRY LA English DT Article DE crown ethers; complexes; stability constants; structure-property relationships; computational neural networks ID MOLECULAR MECHANICS; MACROCYCLE INTERACTION; ORGANIC-COMPOUNDS; GRAPH-THEORY; KINETIC DATA; CHEMISTRY; DEVICES; CATIONS; K+ AB A computational neural network method was used for the prediction of stability constants of simple crown ether complexes. The essence of the method lies in the ability of a computer neural network to recognize the structure-property relationships in these host-guest systems. Testing of the computational method has demonstrated that stability constants of alkali metal cation (Na+, Kf, Cs+)-crown ether complexes in methanol at 25 degrees C can be predicted with an average error of +/-0.3 log K units based on the chemical structure of the crown ethers alone. The computer model was then used for the preliminary analysis of trends in the stabilities of the above complexes. RP Gakh, AA (reprint author), OAK RIDGE NATL LAB,DIV CHEM & ANALYT SCI,POB 2008,OAK RIDGE,TN 37831, USA. RI Solominow, Sonia/A-4021-2008; Sumpter, Bobby/C-9459-2013; Moyer, Bruce/L-2744-2016 OI Sumpter, Bobby/0000-0001-6341-0355; Moyer, Bruce/0000-0001-7484-6277 NR 22 TC 18 Z9 19 U1 1 U2 4 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0923-0750 J9 J INCLUS PHENOM MOL JI J. Incl. Phenom. Mol. Recogn. Chem. PD MAR PY 1997 VL 27 IS 3 BP 201 EP 213 DI 10.1023/A:1007928814162 PG 13 WC Chemistry, Multidisciplinary; Crystallography SC Chemistry; Crystallography GA WV121 UT WOS:A1997WV12100002 ER PT J AU ONeill, JP VanBrocklin, HF Morimoto, H Williams, PG AF ONeill, JP VanBrocklin, HF Morimoto, H Williams, PG TI Synthesis of H-3 labeled dihydrorotenone SO JOURNAL OF LABELLED COMPOUNDS & RADIOPHARMACEUTICALS LA English DT Article DE tritium; dihydrorotenone; dihydrorotenol; H-3-NMR ID ELECTRON-TRANSPORT CHAIN; COMPLEX-I; DISEASE; BINDING; HYDROGENATION; PRODUCTS; NADH AB The catalytic tritiation of rotenone results in the preparation of two products, the expected tritiated 6',7'-dihydrorotenone ([H-3]DHR) and tritiated 6',7'-dihydrorotenol ([H-3]DHR-ol). The ratio of [H-3]DHR to [H-3]DHR-ol is 9 to 1. Reversed-phase HPLC provided the purified [H-3]DHR and [H-3]DHR-ol with estimated specific activities of 45 and 60 Ci/mmol, respectively. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,NATL TRITIUM LABELLING FACIL,BERKELEY,CA 94720. RP ONeill, JP (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,CTR FUNCT IMAGING,BERKELEY,CA 94720, USA. NR 17 TC 5 Z9 5 U1 0 U2 0 PU JOHN WILEY & SONS LTD PI W SUSSEX PA BAFFINS LANE CHICHESTER, W SUSSEX, ENGLAND PO19 1UD SN 0362-4803 J9 J LABELLED COMPD RAD JI J. Label. Compd. Radiopharm. PD MAR PY 1997 VL 39 IS 3 BP 215 EP 221 DI 10.1002/(SICI)1099-1344(199703)39:3<215::AID-JLCR961>3.0.CO;2-E PG 7 WC Biochemical Research Methods; Chemistry, Medicinal; Chemistry, Analytical SC Biochemistry & Molecular Biology; Pharmacology & Pharmacy; Chemistry GA WL166 UT WOS:A1997WL16600004 ER PT J AU Aloia, JF Vaswani, A Ma, RM Flaster, E AF Aloia, JF Vaswani, A Ma, RM Flaster, E TI Comparison of body composition in black and white premenopausal women SO JOURNAL OF LABORATORY AND CLINICAL MEDICINE LA English DT Article ID NEUTRON-ACTIVATION ANALYSIS; DUAL-PHOTON-ABSORPTIOMETRY; X-RAY ABSORPTIOMETRY; BONE MASS; RACIAL-DIFFERENCES; VITAMIN-D; DENSITY; CALCIUM; NITROGEN; FAT AB We examined 23 pairs of black and white premenopausal women to determine whether there were ethnic differences in body composition, The pairs were matched on weight and height. Each woman had measurements of total body water taken by a tritiated water dilution technique, total body nitrogen, and total body carbon by neutron-activation, mineral ash by dual x-ray absorptiometry, and body potassium by whole body counting. Differences between blacks and whites were compared with the use of both the two-compartment and four-compartment models. The two-compartment model showed that in premenopausal black and white women of similar age, heights, and weights, blacks had significantly more lean mass. The four-compartment model resulted in similar conclusions. The black women had larger protein, mineral, and water compartments and less fat than whites. It may be that body weight measurements as an indicator of obesity should be adjusted for black versus white women. C1 BROOKHAVEN NATL LAB,UPTON,NY 11973. RP Aloia, JF (reprint author), WINTHROP UNIV HOSP,DEPT MED,259 1ST ST,MINEOLA,NY 11501, USA. NR 36 TC 42 Z9 42 U1 0 U2 0 PU MOSBY-YEAR BOOK INC PI ST LOUIS PA 11830 WESTLINE INDUSTRIAL DR, ST LOUIS, MO 63146-3318 SN 0022-2143 J9 J LAB CLIN MED JI J. Lab. Clin. Med. PD MAR PY 1997 VL 129 IS 3 BP 294 EP 299 DI 10.1016/S0022-2143(97)90177-3 PG 6 WC Medical Laboratory Technology; Medicine, General & Internal; Medicine, Research & Experimental SC Medical Laboratory Technology; General & Internal Medicine; Research & Experimental Medicine GA WK940 UT WOS:A1997WK94000006 PM 9042814 ER PT J AU Ju, HL Sohn, H AF Ju, HL Sohn, H TI Magnetic inhomogeneity and colossal magnetoresistance in manganese oxides SO JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS LA English DT Article DE manganese oxide; magnetoresistance; polaron; magnetic inhomogeneity; perovskite structure ID GIANT NEGATIVE MAGNETORESISTANCE; MN-O FILMS; TEMPERATURE; DEPENDENCE AB The magnetic and magnetotransport properties of the manganites, R(1-x)A(x)MnO(z) (R = La, Pr, Nd; A = Ca, Sr, Ba), are strongly dependent on the doping level x and oxygen stoichiometry z. For x greater than or equal to similar to 0.2, stoichiometric R(1-x)A(x)MnO(3) was found to have a small temperature independent coercivity of 5-30 Oe and the saturation magnetiztion (similar to 90 emu/g) of fully aligned Mn ions. Oxygen deficient (or x < 0.2) R(1-x)A(x)MnO(z) has a saturation magnetization smaller than that of fully aligned Mn spins and shows an enhancement and temperature dependence of the coercivity, and spin freezing behavior, The latter is characterized by a peal; in zero field cooled (ZFC) magnetization. Our data suggest that oxygen deficient or low doped manganites are magnetically inhomogeneous. We discuss possible origins of the magnetic inhomogeneity and its influence on the colossal magnetoresistance. C1 UNIV MARYLAND,DEPT PHYS,CTR SUPERCONDUCT RES,COLLEGE PK,MD 20742. RP Ju, HL (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV MAT SCI,BERKELEY,CA 94720, USA. NR 25 TC 107 Z9 108 U1 2 U2 12 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0304-8853 J9 J MAGN MAGN MATER JI J. Magn. Magn. Mater. PD MAR PY 1997 VL 167 IS 3 BP 200 EP 208 DI 10.1016/S0304-8853(96)00647-6 PG 9 WC Materials Science, Multidisciplinary; Physics, Condensed Matter SC Materials Science; Physics GA WP599 UT WOS:A1997WP59900004 ER PT J AU Pecharsky, VK Gschneidner, KA AF Pecharsky, VK Gschneidner, KA TI Effect of alloying on the giant magnetocaloric effect of Gd-5(Si2Ge2) SO JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS LA English DT Letter DE magnetocaloric effect; alloying; substitution effect AB A study of the effect of different alloying additions substituting for nonmagnetic Si and Ge on the giant magnetocaloric effect observed for the compound Gd-5(Si2Ge2) revealed that small amounts (similar to 0.33 at%) of Ga raise the Curie temperature and preserve the giant magnetocaloric effect. Larger quantities of Ga lead to a significant reduction in the magnetocaloric effect, but the Curie temperature continues to rise. Many 3d-metal and p-element additions also reduce the magnetocaloric effect in Gd-5(Si2Ge2) due to the changes in the thermodynamic nature of the magnetic phase transition. In general, all alloying additions raise the Curie temperature of the parent Gd-5(Si2Ge2). C1 IOWA STATE UNIV SCI & TECHNOL,DEPT MAT SCI & ENGN,AMES,IA 50011. RP Pecharsky, VK (reprint author), IOWA STATE UNIV SCI & TECHNOL,AMES LAB,242 SPEDDING,AMES,IA 50011, USA. NR 5 TC 175 Z9 196 U1 4 U2 24 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0304-8853 J9 J MAGN MAGN MATER JI J. Magn. Magn. Mater. PD MAR PY 1997 VL 167 IS 3 BP L179 EP L184 DI 10.1016/S0304-8853(96)00759-7 PG 6 WC Materials Science, Multidisciplinary; Physics, Condensed Matter SC Materials Science; Physics GA WP599 UT WOS:A1997WP59900001 ER PT J AU Kinney, JH Haupt, DL AF Kinney, JH Haupt, DL TI Evidence of critical scaling behavior during vapor phase synthesis of continuous filament composites SO JOURNAL OF MATERIALS RESEARCH LA English DT Article ID CERAMIC COMPOSITES; INFILTRATION; FABRICATION; MICROTOMOGRAPHY; PERCOLATION AB We present experimental measurements of the accessible pore fraction in ceramic matrix composites during consolidation by vapor phase infiltration. For two topologically distinct filament architectures, the accessible pore fraction decreased during consolidation with a power law decay and a critical scaling exponent of 0.41 (R(2) = 0.97). A three-dimensional analysis of the percolating pores revealed that the structures became topologically equivalent and simply connected near the critical density. RP Kinney, JH (reprint author), LAWRENCE LIVERMORE NATL LAB,DEPT CHEM & MAT SCI,LIVERMORE,CA 94550, USA. NR 18 TC 7 Z9 7 U1 0 U2 0 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DR, WARRENDALE, PA 15086 SN 0884-2914 J9 J MATER RES JI J. Mater. Res. PD MAR PY 1997 VL 12 IS 3 BP 610 EP 612 DI 10.1557/JMR.1997.0091 PG 3 WC Materials Science, Multidisciplinary SC Materials Science GA WM879 UT WOS:A1997WM87900010 ER PT J AU Paranthaman, M List, FA Goyal, A Specht, ED Vallet, CE Kroeger, DM Christen, DK AF Paranthaman, M List, FA Goyal, A Specht, ED Vallet, CE Kroeger, DM Christen, DK TI Growth of TlBa2Ca2Cu3O9-y superconducting films with local biaxial alignment extending up to 5 mm on Ag substrates using a spray-pyrolysis technique SO JOURNAL OF MATERIALS RESEARCH LA English DT Article ID THICK-FILMS; OXIDE AB We report on the superconducting properties of TlBa2Ca2Cu3O9-y (T1-1223) thick films grown on smooth and rough Ag substrates. Thallium-free precursor films of the type Ba2Ca2CU3Ag0.37O7 were deposited on Ag substrates using a spray-pyrolysis technique followed by post-thallination in a two-zone furnace. X-ray diffraction (XRD) results showed the presence of c-axis aligned T1-1223 films and some degree of local in-plane texture (often referred to as a colony microstructure). The microstructure of the Ag surface dictates the growth behavior of T1-1223 films. The transport critical-current densities (J(c)) for T1-1223 films grown on smooth and rough Ag substrates were similar to 65,000 A/cm(2) and similar to 37,000 A/cm(2), respectively, at 77 K and zero held. The films grown on smooth Ag substrates were strongly Linked and bad good in-field properties with a J(c) value of similar to 10(4) A/cm(2) at 77 K and 0.5 T. C1 OAK RIDGE NATL LAB,DIV MET & CERAM,OAK RIDGE,TN 37831. OAK RIDGE NATL LAB,DIV SOLID STATE,OAK RIDGE,TN 37831. RP Paranthaman, M (reprint author), OAK RIDGE NATL LAB,DIV CHEM & ANALYT SCI,OAK RIDGE,TN 37831, USA. RI Specht, Eliot/A-5654-2009; Paranthaman, Mariappan/N-3866-2015 OI Specht, Eliot/0000-0002-3191-2163; Paranthaman, Mariappan/0000-0003-3009-8531 NR 8 TC 6 Z9 6 U1 0 U2 0 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DR, WARRENDALE, PA 15086 SN 0884-2914 J9 J MATER RES JI J. Mater. Res. PD MAR PY 1997 VL 12 IS 3 BP 619 EP 623 DI 10.1557/JMR.1997.0094 PG 5 WC Materials Science, Multidisciplinary SC Materials Science GA WM879 UT WOS:A1997WM87900013 ER PT J AU Janney, MA Kimrey, HD Allen, WR Kiggans, JO AF Janney, MA Kimrey, HD Allen, WR Kiggans, JO TI Enhanced diffusion in sapphire during microwave heating SO JOURNAL OF MATERIALS SCIENCE LA English DT Article ID OXYGEN SELF-DIFFUSION; SINGLE-CRYSTAL AL2O3; ALUMINA; FIELD AB The diffusion of oxygen in sapphire was accelerated by heating in a 28 GHz microwave furnace as compared with heating in a conventional furnace. Tracer diffusion experiments were conducted using O-18. Single crystal sapphire wafers with a (<10(1)over bar 2>) rhombohedral planar orientation were used as the substrate. Concentration depth profiling was done by proton activation analysis using a 5 MeV Van de Graaff accelerator. The diffusion of O-18 was greatly enhanced by microwave heating as compared with conventional heating in the 1500-1800 degrees C range. The apparent activation energy for O-18 bulk diffusion was determined to be 390 kJ mol(-1) with microwave heating and 650 kJ mol(-1) with conventional heating. RP Janney, MA (reprint author), OAK RIDGE NATL LAB,DIV MET & CERAM,POB 2008,OAK RIDGE,TN 37831, USA. RI kiggans, james/E-1588-2017 OI kiggans, james/0000-0001-5056-665X NR 44 TC 67 Z9 78 U1 4 U2 15 PU CHAPMAN HALL LTD PI LONDON PA 2-6 BOUNDARY ROW, LONDON, ENGLAND SE1 8HN SN 0022-2461 J9 J MATER SCI JI J. Mater. Sci. PD MAR 1 PY 1997 VL 32 IS 5 BP 1347 EP 1355 DI 10.1023/A:1018568909719 PG 9 WC Materials Science, Multidisciplinary SC Materials Science GA WL613 UT WOS:A1997WL61300031 ER PT J AU Hsueh, CH AF Hsueh, CH TI Effects of interfacial roughness on fibre push-out SO JOURNAL OF MATERIALS SCIENCE LETTERS LA English DT Article ID FIBER PULL-OUT; REINFORCED COMPOSITES; CERAMIC COMPOSITES; BRITTLE-MATRIX; STRESSES RP Hsueh, CH (reprint author), OAK RIDGE NATL LAB,DIV MET & CERAM,OAK RIDGE,TN 37831, USA. RI Hsueh, Chun-Hway/G-1345-2011 NR 20 TC 2 Z9 2 U1 0 U2 1 PU CHAPMAN HALL LTD PI LONDON PA 2-6 BOUNDARY ROW, LONDON, ENGLAND SE1 8HN SN 0261-8028 J9 J MATER SCI LETT JI J. Mater. Sci. Lett. PD MAR 1 PY 1997 VL 16 IS 5 BP 354 EP 357 DI 10.1023/A:1018590210414 PG 4 WC Materials Science, Multidisciplinary SC Materials Science GA WL616 UT WOS:A1997WL61600005 ER PT J AU Wekesa, JW Yuval, B Washino, RK AF Wekesa, JW Yuval, B Washino, RK TI Multiple blood feeding by Anopheles freeborni and Culex tarsalis (Diptera: Culicidae): Spatial and temporal variation SO JOURNAL OF MEDICAL ENTOMOLOGY LA English DT Article DE Anopheles freeborni; Culex tarsalis; abundance; histology; blood feeding success; multiple blood feeding ID GONOTROPHIC CYCLE; HOST SELECTION; MOSQUITOS; IDENTIFICATION; BEHAVIOR; MEALS AB Multiple blood feeding in field populations of Anopheles freeborni Aitken and Culex tarsalis Coquillet was detected using a histologic technique. Examination of 333 blood engorged An. freeborni and 41 C.x. tarsalis females revealed that 13 and 10% of these females imbibed multiple blood meals, respectively. Spatial and temporal distribution of multiple blood feeding events was evaluated against the percentage of blood fed females and the abundance of female mosquitoes. The percentage of blood fed An. freeborni females was higher among those collected in pasture and riparian habitats than those collected in rice field and mixed habitats. Conversely, spatial variation of multiple blood feeding in An. freeborni was not significantly associated with rice field, pasture, riparian, or mixed habitats. The decrease of multiple blood feeding for An. freeborni through the season was correlated inversely with the increase of the abundance of adult females; but not with the percentage of blood fed females. These results confirmed that multiple blood meals in An. freeborni, and perhaps in Cx. tarsalis, are a frequent phenomenon, and that the histologic procedure is an appropriate tool for longitudinal and region-wide detection of multiple blood feeding necessary in epidemiologic studies. C1 LAWRENCE LIVERMORE NATL LAB,DEPT ENTOMOL,DAVIS,CA 95616. RI Yuval, Boaz/C-3447-2009 OI Yuval, Boaz/0000-0002-6864-3825 NR 39 TC 14 Z9 14 U1 0 U2 2 PU ENTOMOL SOC AMER PI LANHAM PA 9301 ANNAPOLIS RD, LANHAM, MD 20706 SN 0022-2585 J9 J MED ENTOMOL JI J. Med. Entomol. PD MAR PY 1997 VL 34 IS 2 BP 219 EP 225 PG 7 WC Entomology; Veterinary Sciences SC Entomology; Veterinary Sciences GA WP050 UT WOS:A1997WP05000017 PM 9103766 ER PT J AU Stapp, HP AF Stapp, HP TI Science of consciousness and the hard problem SO JOURNAL OF MIND AND BEHAVIOR LA English DT Article AB Quantum theory can be regarded as a rationally coherent theory of the interaction of mind and matter, and it allows our conscious thoughts to play a causally efficacious and necessary role in brain dynamics. It therefore provides a natural basis, created by scientists, for the science of consciousness As an illustration it is explained how the interaction of brain and consciousness can speed up brain processing, and thereby enhance the survival prospects of conscious organisms, as compared to similar organisms that lack consciousness. As a second illustration it is explained how, within the quantum framework, the consciously experienced ''I'' directs the actions of a human being. It is concluded that contemporary science already has an adequate framework for incorporating causally efficacious experiential events into the physical universe in a manner that: (1) puts the neural correlates of consciousness into the theory in a well defined way, (2) explains in principle how the effects of consciousness, per se, can enhance the survival prospects of organisms that possess it, (3) allows this survival effect to feed into phylogenetic development, and (4) explains how the consciously experienced ''I'' can direct human behavior. RP Stapp, HP (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,BERKELEY,CA 94720, USA. NR 27 TC 8 Z9 8 U1 0 U2 3 PU INST MIND BEHAVIOR INC PI NEW YORK PA PO BOX 522 VILLAGE STATION, NEW YORK, NY 10014 SN 0271-0137 J9 J MIND BEHAV JI J. Mind Behav. PD SPR-SUM PY 1997 VL 18 IS 2-3 BP 171 EP 193 PG 23 WC Psychology, Multidisciplinary; Psychology, Experimental SC Psychology GA YF124 UT WOS:A1997YF12400005 ER PT J AU Tseng, SH Eggers, DF Blake, TA Beck, R Watts, RO Lovas, FJ Zobov, N AF Tseng, SH Eggers, DF Blake, TA Beck, R Watts, RO Lovas, FJ Zobov, N TI Infrared and microwave spectra of the N-2-propyne van der Waals cluster SO JOURNAL OF MOLECULAR SPECTROSCOPY LA English DT Article ID INTERNAL-ROTATION; HIGH-RESOLUTION; SPECTROSCOPY; FORMAMIDE; PROPYNE; COMPLEX AB The infrared spectrum of N-14(2)-CH3CCH in the 3.0-mu m region has been observed and the rovibrational transitions have been assigned for the A (m = 0) and E (m = +/- 1) methyl top internal rotor states of this near slipped parallel van der Waals molecule. The E-state transitions were used to estimate the barrier to internal rotation as 10 cm(-1). The observed A-state microwave transitions of N-14(2)-CH3CCH, N-15(2)-CH3CCH, and N-15(2)-CH3CCD are split into doublets, This doubler splitting, which is too small to be observed in the infrared spectrum, is attributed to the internal motion of the N-2 moiety about an axis connecting the centers-of-mass of the molecules in the cluster; i.e., the N-2 molecule relates out of the heavy atom plane of the cluster. The splittings in the microwave spectra were fit to a barrier height of 71 cm(-1) for the hindered N-2 motion. (C) 1997 Academic Press. C1 UNIV WASHINGTON, DEPT CHEM, SEATTLE, WA 98195 USA. NIST, OPT TECHNOL DIV, GAITHERSBURG, MD 20899 USA. PACIFIC NW LAB, RICHLAND, WA 99352 USA. ECOLE POLYTECH FED LAUSANNE, INST CHIM PHYS MOL, CH-1015 LAUSANNE, SWITZERLAND. UNIV MELBOURNE, SCH CHEM, PARKVILLE, VIC 3052, AUSTRALIA. INST PHYS APPL, NIZHNII NOVGOROD, RUSSIA. NR 17 TC 3 Z9 3 U1 1 U2 4 PU ACADEMIC PRESS INC JNL-COMP SUBSCRIPTIONS PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 SN 0022-2852 J9 J MOL SPECTROSC JI J. Mol. Spectrosc. PD MAR PY 1997 VL 182 IS 1 BP 132 EP 147 DI 10.1006/jmsp.1996.7193 PG 16 WC Physics, Atomic, Molecular & Chemical; Spectroscopy SC Physics; Spectroscopy GA WN854 UT WOS:A1997WN85400014 ER PT J AU Jin, P Chang, BC Fei, R Sears, TJ AF Jin, P Chang, BC Fei, R Sears, TJ TI High-resolution infrared diode laser spectroscopy of X(2)Pi CCl SO JOURNAL OF MOLECULAR SPECTROSCOPY LA English DT Article ID SPECTRUM; TRANSITION; NU-2 AB The high-resolution transient infrared spectrum of X(2) Pi CCl near 12.2 mu m was measured by diode laser absorption spectroscopy following 193 nm excimer laser photolysis of CHClBr2. Many lines in the nu = 1-0, 2 <-- 1, 3-2, 4-3, and 5-4 bands for (CCl)-Cl-35 were identified in addition to lines in the first four of these vibrational bands for (CCl)-Cl-37. Th, new data were combined in a least squares fit to all the available high resolution infrared data, and combination differences from the electronic spectrum of the radical, including both chlorine isotopes simultaneously. The equilibrium molecular parameters so determined are more complete than previously available and should reliably predict higher vibrational bands. The results were used to estimate a potential curve for the radical, from the Rydberg-Klein-Rees procedure, and fits to the data for the individual isotopes allowed a separation of the spin-rotation and centrifugal distortion of the spin-orbit fine structure terms. (C) 1997 Academic Press. RP Jin, P (reprint author), BROOKHAVEN NATL LAB,DEPT CHEM,UPTON,NY 11973, USA. RI Sears, Trevor/B-5990-2013 OI Sears, Trevor/0000-0002-5559-0154 NR 18 TC 18 Z9 18 U1 1 U2 3 PU ACADEMIC PRESS INC JNL-COMP SUBSCRIPTIONS PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 SN 0022-2852 J9 J MOL SPECTROSC JI J. Mol. Spectrosc. PD MAR PY 1997 VL 182 IS 1 BP 189 EP 194 DI 10.1006/jmsp.1996.7202 PG 6 WC Physics, Atomic, Molecular & Chemical; Spectroscopy SC Physics; Spectroscopy GA WN854 UT WOS:A1997WN85400019 ER PT J AU Honda, T Bartels, HW Uckan, NA Seki, Y Okazaki, T AF Honda, T Bartels, HW Uckan, NA Seki, Y Okazaki, T TI Development of time dependent safety analysis code for plasma anomaly events in fusion reactors SO JOURNAL OF NUCLEAR SCIENCE AND TECHNOLOGY LA English DT Article DE ITER; plasma anomaly events; safety analysis; computer code; plasma dynamics; thermal analysis; beta limit; density limit; confinement transition; in-vessel components ID THERMONUCLEAR EXPERIMENTAL REACTOR; SYSTEM AB A safety analysis code SAFALY has been developed to analyze plasma anomaly events in fusion reactors, e.g., a loss of plasma control. The code is a hybrid code comprising a zero-dimensional plasma dynamics and a one-dimensional thermal analysis of in-vessel components. The code evaluates the time evolution of plasma parameters and temperature distributions of in-vessel components. As the plasma-safety interface model, we proposed a robust plasma physics model taking into account updated data for safety assessment. For example, physics safety guidelines for beta limit, density limit and H-L mode confinement transition threshold power, etc. are provided in the model. The model of the in-vessel components are divided into twenty temperature regions in the poloidal direction taking account of radiative heat transfer between each surface of each region. This code can also describe the coolant behavior under hydraulic accidents with the results by hydraulics code and treat vaporization (sublimation) from plasma facing components (PFCs). Furthermore, the code includes the model of impurity transport form PFCs by using a transport probability and a time delay. Quantitative analysis based on the model is possible for a scenario of plasma passive shutdown. We examined the possibility of the code as a safety analysis code for plasma anomaly events in fusion reactors and had a prospect that it would contribute to the safety analysis of the International Thermonuclear Experimental Reactor (ITER). C1 ITER JOINT CENT TEAM, SAN DIEGO, CA USA. OAK RIDGE NATL LAB, OAK RIDGE, TN 37831 USA. JAPAN ATOM ENERGY RES INST, NAKA FUS RES ESTAB, NAKA, IBARAKI 31101, JAPAN. RP HITACHI LTD, HITACHI RES LAB, OMIKA CHO, HITACHI, IBARAKI 31912, JAPAN. NR 16 TC 8 Z9 8 U1 0 U2 0 PU TAYLOR & FRANCIS LTD PI ABINGDON PA 2-4 PARK SQUARE, MILTON PARK, ABINGDON OR14 4RN, OXON, ENGLAND SN 0022-3131 EI 1881-1248 J9 J NUCL SCI TECHNOL JI J. Nucl. Sci. Technol. PD MAR PY 1997 VL 34 IS 3 BP 229 EP 239 DI 10.1080/18811248.1997.9733655 PG 11 WC Nuclear Science & Technology SC Nuclear Science & Technology GA WX288 UT WOS:A1997WX28800001 ER PT J AU Dukowicz, JK AF Dukowicz, JK TI Comments on ''Stability of the viscous-plastic sea ice rheology'' SO JOURNAL OF PHYSICAL OCEANOGRAPHY LA English DT Editorial Material RP Dukowicz, JK (reprint author), LOS ALAMOS NATL LAB,DIV THEORET,GRP T3,MAIL STOP B216,LOS ALAMOS,NM 87545, USA. NR 3 TC 12 Z9 12 U1 1 U2 6 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0022-3670 J9 J PHYS OCEANOGR JI J. Phys. Oceanogr. PD MAR PY 1997 VL 27 IS 3 BP 480 EP 481 DI 10.1175/1520-0485(1997)027<0480:COSOTV>2.0.CO;2 PG 2 WC Oceanography SC Oceanography GA WN714 UT WOS:A1997WN71400008 ER PT J AU Tang, J Norris, JR Shirakawa, H AF Tang, J Norris, JR Shirakawa, H TI EPR lineshape analysis of one-dimensional soliton diffusion in trans-polyacetylene SO JOURNAL OF PHYSICS AND CHEMISTRY OF SOLIDS LA English DT Article DE polymer; diffusion; electron paramagnetic resonance (EPR) ID ELECTRON-SPIN-RESONANCE; DOPED POLYACETYLENE; MAGNETIC-RESONANCE; (CH)X; DEFECTS AB The one-dimensional diffusion processes of solitons in trans-polyacetylene are studied by time-domain analysis of EPR measurements. The temperature dependence of the diffusion rate constant appears to obey a simple power law. Monte Carlo simulations of the diffusion processes indicate that impurity traps can cause a significant slow down of the overall diffusion rate. Published by Elsevier Science Limited. C1 UNIV CHICAGO,DEPT CHEM,CHICAGO,IL 60637. UNIV TSUKUBA,INST MAT SCI,SAKURA,IBARAKI 305,JAPAN. RP Tang, J (reprint author), ARGONNE NATL LAB,DIV CHEM,9700 S CASS AVE,ARGONNE,IL 60439, USA. RI Tang, Jau/D-8382-2012 OI Tang, Jau/0000-0003-2078-1513 NR 20 TC 0 Z9 0 U1 0 U2 1 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 MAR PY 1997 VL 58 IS 3 BP 475 EP 480 DI 10.1016/S0022-3697(96)00140-0 PG 6 WC Chemistry, Multidisciplinary; Physics, Condensed Matter SC Chemistry; Physics GA WM265 UT WOS:A1997WM26500018 ER PT J AU Hsieh, YL Hu, XP AF Hsieh, YL Hu, XP TI Structural transformation of ultra-high modulus and molecular weight polyethylene fibers by high-temperature wide-angle X-ray diffraction SO JOURNAL OF POLYMER SCIENCE PART B-POLYMER PHYSICS LA English DT Article DE ultra-high modulus and molecular weight polyethylene fibers (UHMWPE); high-temperature wide-angle x-ray diffraction (HTWAXD); crystal structure; orthorhombic/monoclinic/pseudohexagonal transformation; annealing and thermal behavior ID HIGH-RESOLUTION NMR; LONGITUDINAL GROWTH; FLOWING SOLUTIONS; POLYMER CRYSTALS; MELTING BEHAVIOR; MORPHOLOGY; DSC AB Wide-angle x-ray diffraction (WAXD) of the ultra-high modulus and molecular weight polyethylene (UHMWPE) fibers at room temperature shows a predominantly orthorhombic structure with trace amount of nonorthorhombic crystals and very low amorphous contents. The calculated unit cell dimensions a and b of the orthorhombic crystals are 7.36 (+/-0.04) Angstrom and 4.89 (+/-0.04) Angstrom, respectively. The apparent crystallite sizes perpendicular to the orthorhombic 110 and 200 reflection planes are 169.8 and 143.4 Angstrom, respectively. The crystallite size perpendicular to the nonorthorhombic 010 reflection is 149.4 Angstrom. The crystal density is calculated to be 1.02 g/cc. With increasing temperature, the thermal expansion coefficient in the a direction is much higher than that in the b direction which explains the structural transformation from the orthorhombic crystals to a pseudohexagonal form. Tension along the fiber axis while being heated during the high-temperature x-ray diffraction (HTWAXD) scanning has shown enhanced structural transformation from the orthorhombic form to the monoclinic form. Structural transformation from the orthorhombic form to the pseudohexagonal phase is not observed on the UHMWPE fibers under axial tension or annealing conditions in HTWAXD. (C) 1997 John Wiley & Sons, Inc. RP Hsieh, YL (reprint author), LAWRENCE LIVERMORE NATL LAB,DAVIS,CA 95616, USA. NR 25 TC 28 Z9 29 U1 2 U2 16 PU JOHN WILEY & SONS INC PI NEW YORK PA 605 THIRD AVE, NEW YORK, NY 10158-0012 SN 0887-6266 J9 J POLYM SCI POL PHYS JI J. Polym. Sci. Pt. B-Polym. Phys. PD MAR PY 1997 VL 35 IS 4 BP 623 EP 630 DI 10.1002/(SICI)1099-0488(199703)35:4<623::AID-POLB10>3.0.CO;2-I PG 8 WC Polymer Science SC Polymer Science GA WL260 UT WOS:A1997WL26000010 ER PT J AU Lee, SY Watkins, DR Jackson, BL Schmoyer, RL Lietzke, DA Burgoa, BB Branson, JT Ammons, JT AF Lee, SY Watkins, DR Jackson, BL Schmoyer, RL Lietzke, DA Burgoa, BB Branson, JT Ammons, JT TI Evaluation of metal and radionuclide data from neutron activation and acid-digestion-based spectrometry analyses of background soils: Significance in environmental restoration SO JOURNAL OF RADIOANALYTICAL AND NUCLEAR CHEMISTRY LA English DT Article; Proceedings Paper CT 9th International Conference on Modern Trends in Activation Analysis (MTAA-9) CY SEP 24-30, 1995 CL SEOUL, SOUTH KOREA SP Korea Inst Geol Min & Mat, Int Atom Energy Agcy, Korean Soc Anal Sci AB A faster, more cost-effective, and higher-quality data acquisition for natural background-level metals and radionuclides in soils is needed for remedial investigations of contaminated sites. The advantages and disadvantages of neutron activation analysis (NAA) compared with those of acid-digestion-based spectrometry (ADS) methods were evaluated using Al, Sb, As, Cr, Co, Fe, Mg, Mn, Hg, K, Ag, Th-232, U-235, U-238, V, and Zn data. The ADS methods used for this project were inductively coupled plasma (ICP), ICP-mass spectrometry (ICP-MS), and alpha spectrometry. Scatter plots showed that the NAA results for As, Co, Fe, Mn, Th-232, and U-238 are reasonably correlated with the results from the other analytical methods. Compared to NAA, however, the ADS methods underestimated Al, Cr, Mg, K, V, and Zn. Because of the high detection limits of ADS methods, the scatter plots of Sb, Hg, and Ag did not show a definite relationship. The NAA results were highly correlated with the alpha spectrometry results for Th-232 and U-238 but poorly correlated for U-235. The NAA, including the delayed neutron counting, was a far superior technique for quantifying background levels of radionuclides (Th-232, U-235, and U-238) and metals (Al, Cr, Mg, K, V, and Zn) in soils. C1 UNIV TENNESSEE,KNOXVILLE,TN 37916. RP Lee, SY (reprint author), OAK RIDGE NATL LAB,OAK RIDGE,TN 37831, USA. NR 16 TC 3 Z9 3 U1 0 U2 0 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0236-5731 J9 J RADIOANAL NUCL CH JI J. Radioanal. Nucl. Chem. PD MAR PY 1997 VL 217 IS 1 BP 57 EP 64 DI 10.1007/BF02055349 PG 8 WC Chemistry, Analytical; Chemistry, Inorganic & Nuclear; Nuclear Science & Technology SC Chemistry; Nuclear Science & Technology GA XV472 UT WOS:A1997XV47200009 ER PT J AU Grant, KE Mong, GM Lucke, RB Campbell, JA AF Grant, KE Mong, GM Lucke, RB Campbell, JA TI Quantitative determination of chelators and their degradation products in mixed hazardous wastes from tank 241-SY-101 using derivatization GC/MS (vol 211, pg 383, 1996) SO JOURNAL OF RADIOANALYTICAL AND NUCLEAR CHEMISTRY LA English DT Correction RP Grant, KE (reprint author), PACIFIC NW LAB, ADV ORG ANALYT METHODS DEV GRP, BOX 999, RICHLAND, WA 99352 USA. NR 1 TC 0 Z9 0 U1 0 U2 0 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0236-5731 J9 J RADIOANAL NUCL CH JI J. Radioanal. Nucl. Chem. PD MAR PY 1997 VL 217 IS 1 BP 151 EP 151 DI 10.1007/BF02055366 PG 1 WC Chemistry, Analytical; Chemistry, Inorganic & Nuclear; Nuclear Science & Technology SC Chemistry; Nuclear Science & Technology GA XV472 UT WOS:A1997XV47200026 ER PT J AU Greening, LA Sanstad, AH Mcmahon, JE AF Greening, LA Sanstad, AH Mcmahon, JE TI Effects of appliance standards on product price and attributes: An hedonic pricing model SO JOURNAL OF REGULATORY ECONOMICS LA English DT Article ID FUNCTIONAL FORM; CHOICE AB The tradeoffs between energy efficiency gains and product attributes as a result of the implementation of federal energy performance standards are examined. Hedonic pricing relationships are used to estimate changes in standardized marginal attribute prices for freezer volumes, food volumes, and annual energy consumption for refrigerators and ref refrigerator/freezers. From 1987/88 to 1993, energy performance standards significantly reduced energy consumption and at the same time, a historical decline in ''quality-adjusted'' real prices continued without disruption and consumers appeared to experience a welfare gain as a result of improving revels of energy efficiency. RP Greening, LA (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,ENERGY ANAL PROGRAM,DIV ENERGY & ENVIRONM,BERKELEY,CA 94720, USA. NR 31 TC 15 Z9 15 U1 0 U2 4 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0922-680X J9 J REGUL ECON JI J. Regul. Econ. PD MAR PY 1997 VL 11 IS 2 BP 181 EP 194 DI 10.1023/A:1007906300039 PG 14 WC Economics SC Business & Economics GA WJ062 UT WOS:A1997WJ06200004 ER PT J AU Person, TJ Denn, MM AF Person, TJ Denn, MM TI The effect of die materials and pressure-dependent slip on the extrusion of linear low-density polyethylene SO JOURNAL OF RHEOLOGY LA English DT Article ID WALL SLIP; MELT; INSTABILITIES; DISTORTIONS; COATINGS; LLDPE AB The flow of linear low-density polyethylene through stainless-steel slit dies occurred at shear rates approximately 12% higher than in identical alpha-brass dies at the same wall shear stresses, indicating near-wall slip. The flow curves were independent of gap spacing, We show through the slip theory of Hill and co-workers [J. Rheol. 34, 891-918 (1990)] that a measurable gap dependence of the flow curve is not a necessary consequence of wall slip; the flow curves for both stainless steel and alpha-brass dies can be fit with the same rheological parameters, with a difference in the work of adhesion accounting for the differences in the flow curves. X-ray photoelectron spectroscopy revealed differences in the chemistry of brass surfaces with different pretreating, corresponding to small differences in flow curves. Fluorocarbon-coated die surfaces showed no more slip than stainless steel, while the flow curve with gold-coated surfaces followed stainless steel at intermediate stress and brass at high stress. (C) 1997 The Society of Rheology. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV MAT SCI,BERKELEY,CA 94720. UNIV CALIF BERKELEY,DEPT CHEM ENGN,BERKELEY,CA 94720. NR 21 TC 57 Z9 58 U1 1 U2 2 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0148-6055 J9 J RHEOL JI J. Rheol. PD MAR-APR PY 1997 VL 41 IS 2 BP 249 EP 265 DI 10.1122/1.550877 PG 17 WC Mechanics SC Mechanics GA WL626 UT WOS:A1997WL62600005 ER PT J AU Hess, NJ Balmer, ML Bunker, BC Conradson, SD AF Hess, NJ Balmer, ML Bunker, BC Conradson, SD TI Ti XAS of a novel Cs-Ti silicate SO JOURNAL OF SOLID STATE CHEMISTRY LA English DT Article ID XANES; EXAFS AB Ti XANES and EXAFS were performed to determine the coordination environment of Ti in several Ti oxide standards with known structures and two unknowns with CsTiSi2O6.5 composition, one amorphous and one fully crystalline. Analysis of both the XANES and EXAFS data of the unknowns indicate that Ti4+ is 5-fold coordinate in CsTiSi2O6.5 and that the site is highly distorted. Plots of intensity versus the energy of a Ti pre-edge feature result in the separation of 6-, 5-, and 4-fold coordinate Ti into three distinct regions. EXAFS and XANES data show that the Ti coordination environment for the amorphous and crystalline CsTiSi2O6.5 samples is the same indicating that the Ti coordination environment forms early in the crystallization process. Preliminary measurements at the Cs K-edge EXAFS on the same samples shows that the Cs coordination environment is different for the amorphous and the crystalline CsTiSi2O6.5 samples suggesting that the Cs coordination environment forms late in the crystallization process. (C) 1997 Academic Press. C1 LOS ALAMOS NATL LAB, LOS ALAMOS, NM 87545 USA. RP Hess, NJ (reprint author), PACIFIC NW LAB, POB 999, RICHLAND, WA 99352 USA. OI Hess, Nancy/0000-0002-8930-9500 NR 21 TC 25 Z9 25 U1 0 U2 4 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 MAR PY 1997 VL 129 IS 2 BP 206 EP 213 DI 10.1006/jssc.1996.7214 PG 8 WC Chemistry, Inorganic & Nuclear; Chemistry, Physical SC Chemistry GA WX548 UT WOS:A1997WX54800007 ER PT J AU Felmy, AR Rai, D Sterner, SM Mason, MJ Hess, NJ Conradson, SD AF Felmy, AR Rai, D Sterner, SM Mason, MJ Hess, NJ Conradson, SD TI Thermodynamic models for highly charged aqueous species: Solubility of Th(IV) hydrous oxide in concentrated NaHCO3 and Na2CO3 solutions SO JOURNAL OF SOLUTION CHEMISTRY LA English DT Article DE thorium (IV); hydrous oxides; complexation; carbonate; bicarbonate; ion-interaction; spectroscopy ID MULTIPLE-SCATTERING CALCULATIONS; NATURAL-WATERS; ELECTROLYTES; PREDICTION; CARBONATE; MEDIA AB An aqueous thermodynamic model is proposed to describe the solubility of Th(IV) hydrous oxide in the aqueous Na+-HCO3--CO32--OH--ClO4--H2O system extending to high concentration at 25 degrees C. This model is relatively simple in that only two aqueous species are included: Th(OH)(3)CO3- and Th(CO3)(5)(6-). Fitter ion interaction parameters, beta((0)) and beta((1)) for Na+ with Th(CO3)(5)(6-), are also determined (1.31 and 30, respectively). Reconciliation of all of the experimental solubility data for Th(IV) hydrous oxide in NaClO4 media required the introduction of a large mixing parameter for the highly charged Th(CO3)(4)(-). The relatively large values required for the ion interaction parameters beta((0)) and beta((1)), together with commensurately large mixing terms with the bulk anionic species, resulted in considerable uncertainty in determining standard state equilibrium constants for the formation of the highly charged Th(CO3)(5)(6-) species. This uncertainty is a result of the large contributions from beta((0)) and beta((1)) to the excess solution free energy at the concentrations (0.1m) where this species becomes important. The magnitude of the mixing term implies that formation of this species depends strongly upon the bulk ionic media. X-ray absorption results, confirming the presence of the thorium pentacarbonate species in concentrated bicarbonate and carbonate solutions, are also included. C1 LOS ALAMOS NATL LAB, LOS ALAMOS, NM USA. RP Felmy, AR (reprint author), PACIFIC NW LAB, POB 999, RICHLAND, WA 99352 USA. OI Hess, Nancy/0000-0002-8930-9500 NR 22 TC 29 Z9 29 U1 0 U2 9 PU PLENUM PUBL CORP PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 SN 0095-9782 J9 J SOLUTION CHEM JI J. Solut. Chem. PD MAR PY 1997 VL 26 IS 3 BP 233 EP 248 DI 10.1007/BF02767996 PG 16 WC Chemistry, Physical SC Chemistry GA XA776 UT WOS:A1997XA77600001 ER PT J AU Wruck, DA Zhao, P Palmer, CEA Silva, RJ AF Wruck, DA Zhao, P Palmer, CEA Silva, RJ TI Stability quotients of neodymium acetate complexes from 20 to 70 degrees C by laser-induced photoacoustic spectroscopy SO JOURNAL OF SOLUTION CHEMISTRY LA English DT Article DE complexation; neodymium acetate; photoacoustic spectroscopy; spectrophotometry ID ACTINIDE IONS; SPECIATION AB The formation of Nd(III) acetate complexes in aqueous solution is studied by laser-induced photoacoustic spectroscopy and spectrophotometry. Stability quotients for the complexes Nd(CH3COO)(2+) and Nd(CH3COO)2+ and dissociation quotients for acetic acid are determined at 20, 35, 50 and 70 degrees C in NaClO4 medium of ionic strength 2.2m (2.0M at 20 degrees C). The 20 degrees C results are consistent with previous values determined by potentiometry and energy transfer from Tb(III). The temperature dependence of the stability quotients is consistent with the measured enthalpies of reaction at 25 degrees C. RP Wruck, DA (reprint author), LAWRENCE LIVERMORE NATL LAB,ISOTOPE SCI DIV,LIVERMORE,CA 94550, USA. NR 16 TC 11 Z9 11 U1 0 U2 2 PU PLENUM PUBL CORP PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 SN 0095-9782 J9 J SOLUTION CHEM JI J. Solut. Chem. PD MAR PY 1997 VL 26 IS 3 BP 267 EP 275 DI 10.1007/BF02767998 PG 9 WC Chemistry, Physical SC Chemistry GA XA776 UT WOS:A1997XA77600003 ER PT J AU Nogales, E Wolf, SG Downing, KH AF Nogales, E Wolf, SG Downing, KH TI Visualizing the secondary structure of tubulin: Three-dimensional map at 4 angstrom SO JOURNAL OF STRUCTURAL BIOLOGY LA English DT Article ID ELECTRON CRYSTALLOGRAPHY; 3-DIMENSIONAL STRUCTURE; RESOLUTION; COMPLEX; MODEL; TAXOL AB We are in the process of determining the structure of tubulin using electron crystallography of zinc-induced, crystalline sheets. We have now extended the resolution to 4 Angstrom, and there are many features in the map that appear to show details of the secondary structure. X-ray crystallographers are well aware of the problems of interpreting maps with such limited resolution, and the additional problem of the missing cone of data inherent in electron crystallography may make interpretation even more difficult. To investigate how reliably these maps can be interpreted, we have calculated density maps of a known structure, actin, under conditions similar to those of the tubulin map, Results of these simulations support the limited interpretations we made previously in the 6.5-Angstrom maps and the more extensive interpretations we make here in the 4-Angstrom map, Most of the secondary structure of the tubulin dimer can now be identified. (C) 1997 Academic Press. C1 LAWRENCE BERKELEY LAB,BERKELEY,CA 94720. RI WOLF, SHARON/K-1768-2012 OI WOLF, SHARON/0000-0002-5337-5063 NR 18 TC 25 Z9 25 U1 0 U2 2 PU ACADEMIC PRESS INC JNL-COMP SUBSCRIPTIONS PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 SN 1047-8477 J9 J STRUCT BIOL JI J. Struct. Biol. PD MAR PY 1997 VL 118 IS 2 BP 119 EP 127 DI 10.1006/jsbi.1997.3841 PG 9 WC Biochemistry & Molecular Biology; Biophysics; Cell Biology SC Biochemistry & Molecular Biology; Biophysics; Cell Biology GA WT368 UT WOS:A1997WT36800006 PM 9126638 ER PT J AU Woodward, NB AF Woodward, NB TI Low-amplitude evolution of break-thrust folding SO JOURNAL OF STRUCTURAL GEOLOGY LA English DT Article; Proceedings Paper CT Penrose Conference on Fault-Related Folding CY AUG, 1995 CL BANFF, CANADA ID FAULT-PROPAGATION FOLDS; SINGLE-LAYER FOLDS; LOST RIVER RANGE; LIMB ROTATION; STRAIN; KINEMATICS; ROCKS; RHEOLOGY; GEOMETRY; KINKING AB This paper proposes a mechanistic explanation for fault-related, flexural-slip folds that form predominantly by fixed-hinge folding (i.e. break-thrust folds). It also presents a stepwise evolutionary history for these folds which contrasts with the model suggested for self-similar, migrating-hinge, fault-propagation fold models. Both mechanical folding theory and rock-fabric evidence suggest that folding in advance of a growing thrust fault can evolve in a five-step process: (1) initial sinusoidal buckling instability (<2% permanent strain; <10 degrees limb dips), (2) hinge migration from the symmetric buckling instability to an asymmetric kink geometry at very low strains (2-6% strain; 12 degrees-20 degrees forelimb dip) which is driven by interlayer shear stresses, (3) fold growth by limb rotation with fixed anticlinal and synclinal hinges, and propagation of a flat thrust beneath the fold (6-20% strain; 20 degrees-35 degrees forelimb dip), (4) fold locking caused by space problems and the inability to overcome the increasing angular shear required to continue flexural slip folding (20-36% strain; 35 degrees-50 degrees forelimb dip), and (5) partitioning of deformation accommodated by highly strained fold limbs, faulting on the flat basal decollement beneath the entire fold creating a detachment fold, or by continued faulting at the sub-fold ramp resulting in a fault breaking through the earlier fold. Published by Elsevier Science Ltd. RP Woodward, NB (reprint author), US DOE,OFF ENERGY RES,ER 15,19901 GERMANTOWN RD,GERMANTOWN,MD 20874, USA. NR 57 TC 16 Z9 16 U1 0 U2 3 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0191-8141 J9 J STRUCT GEOL JI J. Struct. Geol. PD MAR-APR PY 1997 VL 19 IS 3-4 BP 293 EP 301 DI 10.1016/S0191-8141(96)00102-2 PG 9 WC Geosciences, Multidisciplinary SC Geology GA WR843 UT WOS:A1997WR84300008 ER PT J AU Wenk, HR Heidelbach, F Chateigner, D Zontone, F AF Wenk, HR Heidelbach, F Chateigner, D Zontone, F TI Laue orientation imaging SO JOURNAL OF SYNCHROTRON RADIATION LA English DT Article DE Laue patterns; texture analysis; indexing (automatic); orientation determination; olivine; gnomonic projection ID PATTERNS AB Advantage was taken of the highly focused X-ray beam (10-30 mu m) and the broad white spectrum of synchrotron X-rays at the ESRF for automatic recording of Laue patterns from polycrystals and extraction of orientation information. The procedure used is similar to that applied for electron-backscattering patterns in the scanning electron microscope and provides data for local orientation mapping used in texture analysis. Laue patterns are obtained from a thin slice of material in transmission and recorded with a CCD detector. The Laue geometry is converted into a gnomonic projection in which co-zonal reflections lie on straight lines. On applying the Hough transform these lines are merged into a single point, which is recognized by the computer and assigned zone indices [uvw] by comparison with a table of interzonal angles. From the angular positions of several [uvw] the crystal orientation is calculated. The method is illustrated for the orthorhombic magnesium silicate olivine. C1 CNRS,CRISTALLOG LAB,F-38042 GRENOBLE,FRANCE. LOS ALAMOS NATL LAB,CTR MAT SCI,LOS ALAMOS,NM 87545. EUROPEAN SYNCHROTRON RADIAT FACIL,F-38043 GRENOBLE,FRANCE. RP Wenk, HR (reprint author), UNIV CALIF BERKELEY,DEPT GEOL & GEOPHYS,BERKELEY,CA 94720, USA. RI Chateigner, Daniel/A-7654-2008 OI Chateigner, Daniel/0000-0001-7792-8702 NR 24 TC 21 Z9 21 U1 0 U2 1 PU MUNKSGAARD INT PUBL LTD PI COPENHAGEN PA 35 NORRE SOGADE, PO BOX 2148, DK-1016 COPENHAGEN, DENMARK SN 0909-0495 J9 J SYNCHROTRON RADIAT JI J. Synchrot. Radiat. PD MAR 1 PY 1997 VL 4 BP 95 EP 101 DI 10.1107/S090904959601432X PN 2 PG 7 WC Instruments & Instrumentation; Optics; Physics, Applied SC Instruments & Instrumentation; Optics; Physics GA WR032 UT WOS:A1997WR03200008 PM 16699213 ER PT J AU Blau, PJ AF Blau, PJ TI Symposium on needs and applications in precision measurement and monitoring of wear SO JOURNAL OF TESTING AND EVALUATION LA English DT Editorial Material RP Blau, PJ (reprint author), OAK RIDGE NATL LAB,DIV MET & CERAM,POB 2008,OAK RIDGE,TN 37831, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER SOC TESTING MATERIALS PI W CONSHOHOCKEN PA 100 BARR HARBOR DR, W CONSHOHOCKEN, PA 19428-2959 SN 0090-3973 J9 J TEST EVAL JI J. Test. Eval. PD MAR PY 1997 VL 25 IS 2 BP 215 EP 215 PG 1 WC Materials Science, Characterization & Testing SC Materials Science GA WU021 UT WOS:A1997WU02100010 ER PT J AU Blau, PJ AF Blau, PJ TI Needs and challenges in precision wear measurement SO JOURNAL OF TESTING AND EVALUATION LA English DT Article; Proceedings Paper CT Symposium on Needs and Applications in Precision Measurement and Monitoring of Wear CY MAY 22, 1996 CL ORLANDO, FL SP ASTM, Comm G2 DE wear; wear testing; wear measurements; microindentation; nanoindentation; wear standards; metrology AB Accurate and precise wear measurements are a key element in solving both current wear problems and in facilitating basic wear research. Applications range from assessing the durability of micro-scale components to the accurate screening of surface treatments and thin solid films. The need to distinguish small differences in wear rate presents problems for those who are developing new materials and surface treatments. The sensitivities of methods for measuring wear in ASTM standard test methods are discussed. Errors associated with using alternate methods of wear measurement on the same test specimen are described. Human judgmental factors are a concern in common methods for wear measurement, and the results of an experiment involving measurement of a simulated wear scar by ten different people are described. Precision in wear measurement is limited by both the capabilities of the measuring instruments and by the nonuniformity of wear processes. The advantages and disadvantages of measuring wear using micro- and nano-scale indentations is discussed. The current and future prospects for incorporating advanced, higher-precision wear measurement methods into standards must be evaluated. RP Blau, PJ (reprint author), OAK RIDGE NATL LAB,DIV MET & CERAM,POB 2008,OAK RIDGE,TN 37831, USA. NR 17 TC 2 Z9 2 U1 0 U2 2 PU AMER SOC TESTING MATERIALS PI W CONSHOHOCKEN PA 100 BARR HARBOR DR, W CONSHOHOCKEN, PA 19428-2959 SN 0090-3973 J9 J TEST EVAL JI J. Test. Eval. PD MAR PY 1997 VL 25 IS 2 BP 216 EP 225 PG 10 WC Materials Science, Characterization & Testing SC Materials Science GA WU021 UT WOS:A1997WU02100011 ER PT J AU Zanoria, ES Hamall, K Danyluk, S Zharin, AL AF Zanoria, ES Hamall, K Danyluk, S Zharin, AL TI The nonvibrating Kelvin probe and its application for monitoring surface wear SO JOURNAL OF TESTING AND EVALUATION LA English DT Article; Proceedings Paper CT Symposium on Needs and Applications in Precision Measurement and Monitoring of Wear CY MAY 22, 1996 CL ORLANDO, FL SP ASTM, Comm G2 DE surface wear; work function; Kelvin probe ID WORK-FUNCTION AB This paper reports on the design and development of the nonvibrating Kelvin probe that could be used as a noncontact sensor for tribological damage. This device detects surface charge through temporal variation in the electron work function of a material. Experiments are performed to demonstrate the operation of the probe on a rotating aluminum shaft. The probe, made of lead, is placed adjacent (<0.5-mm distance) to the shaft. The two surfaces, which are electrically connected, form a capacitor. Benchmark experiments on the variation of the work function with changes in surface chemistry were performed by coating a segment along the shaft circumference with a colloidal silver paint. As the shaft rotated, the probe senses changes in the contact potential difference with the shaft surface, due to the compositional variation. The temporal variation in the contact potential difference induces a current in an external electrical circuit. This current is amplified and converted to a voltage signal. The magnitude of the signal decreases asymptotically with the electrode-shaft distance and increases linearly with the rotational frequency, as expected. These results are consistent with the theoretical. Preliminary tests to detect mechanical surface damage, using the probe, were also done. These results show that the Kelvin probe can distinguish geometrical features on the surface. C1 GEORGIA INST TECHNOL,GEORGE W WOODRUFF SCH MECH ENGN,ATLANTA,GA 30332. BELARUSSIAN POWDER MET ASSOC,MINSK 220600,BYELARUS. RP Zanoria, ES (reprint author), OAK RIDGE NATL LAB,DIV MET & CERAM,BOX 2008,BLDG 4515,MS-6063,BETHEL VALLEY RD,OAK RIDGE,TN 37831, USA. NR 9 TC 18 Z9 18 U1 0 U2 2 PU AMER SOC TESTING MATERIALS PI W CONSHOHOCKEN PA 100 BARR HARBOR DR, W CONSHOHOCKEN, PA 19428-2959 SN 0090-3973 J9 J TEST EVAL JI J. Test. Eval. PD MAR PY 1997 VL 25 IS 2 BP 233 EP 238 PG 6 WC Materials Science, Characterization & Testing SC Materials Science GA WU021 UT WOS:A1997WU02100013 ER PT J AU Yust, CS Blau, PJ AF Yust, CS Blau, PJ TI Precision profilometry of wear scars on curved surfaces SO JOURNAL OF TESTING AND EVALUATION LA English DT Article; Proceedings Paper CT Symposium on Needs and Applications in Precision Measurement and Monitoring of Wear CY MAY 22, 1996 CL ORLANDO, FL SP ASTM, Comm G2 DE wear; wear measurement; profilometry; surface roughness; cylinder wear AB Wear scars less than 1 mu m in depth are a challenge to measure accurately by surface profilometry, particularly if they are formed on a curved surface. The resultant curved traces limit the use of the vertical scale enlargements necessary for the detection and measurement of minimal wear scars. Profilometer traces on the surface of an internal combustion engine cylinder, for example, commonly yield curved traces even when the stylus moves parallel to the cylinder axis because of (a) the difficulty in orienting the profilometer trace precisely along an element of the cylindrical surface and (b) small departures from a true cylindrical form in most manufactured cylinders. A simple procedure has been devised that permits a curved trace to be ''straightened'' and scaled to facilitate the determination of wear scar depths and cross sections in the sub-micron range. In some cases, wear scars within the original surface roughness can be detected and measured. The procedure will be illustrated on wear scar depths of 1 mu m and less in cylindrical surfaces. RP Yust, CS (reprint author), OAK RIDGE NATL LAB,DIV MET & CERAM,POB 2008 M-S 6063,OAK RIDGE,TN 37831, USA. NR 4 TC 2 Z9 2 U1 0 U2 0 PU AMER SOC TESTING MATERIALS PI W CONSHOHOCKEN PA 100 BARR HARBOR DR, W CONSHOHOCKEN, PA 19428-2959 SN 0090-3973 J9 J TEST EVAL JI J. Test. Eval. PD MAR PY 1997 VL 25 IS 2 BP 246 EP 249 PG 4 WC Materials Science, Characterization & Testing SC Materials Science GA WU021 UT WOS:A1997WU02100015 ER PT J AU Sigalas, MM AF Sigalas, MM TI Elastic wave band gaps and defect states in two-dimensional composites SO JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA LA English DT Article ID STOP BANDS; PROPAGATION; SYSTEMS AB Using the plane-wave expansion method, we study the propagation of elastic waves through two-dimensional (2-D) periodic composites which exhibit full band gaps for all the polarizations and directions of the displacements. Defect states created inside those band gaps are also studied by disturbing the periodicity of the lattice. Systems exhibiting such kinds of states can be used as acoustical filters. (C) 1997 Acoustical Society of America. C1 IOWA STATE UNIV SCI & TECHNOL, DEPT PHYS & ASTRON, AMES, IA 50011 USA. RP Sigalas, MM (reprint author), IOWA STATE UNIV SCI & TECHNOL, AMES LAB, AMES, IA 50011 USA. NR 30 TC 104 Z9 123 U1 2 U2 15 PU ACOUSTICAL SOC AMER AMER INST PHYSICS PI MELVILLE PA STE 1 NO 1, 2 HUNTINGTON QUADRANGLE, MELVILLE, NY 11747-4502 USA SN 0001-4966 J9 J ACOUST SOC AM JI J. Acoust. Soc. Am. PD MAR PY 1997 VL 101 IS 3 BP 1256 EP 1261 DI 10.1121/1.418156 PG 6 WC Acoustics; Audiology & Speech-Language Pathology SC Acoustics; Audiology & Speech-Language Pathology GA WP115 UT WOS:A1997WP11500004 ER PT J AU Windisch, CF Henager, CH Springer, GD Jones, RH AF Windisch, CF Henager, CH Springer, GD Jones, RH TI Oxidation of the carbon interface in nicalon-fiber-reinforced silicon carbide composite SO JOURNAL OF THE AMERICAN CERAMIC SOCIETY LA English DT Article ID CRACK-GROWTH; KINETICS; MECHANISMS; AIR AB The recession rates for 10(-6)-m-thick C interfaces in chemical vapor infiltrated SIC reinforced with Nicalon fibers were calculated from thermogravimetric data, assuming all of the mass losses were due to C oxidation, and found to be consistent with the measured recession distances of the C interface, which were surprisingly uniform across the composite, Agreement between the two approaches for a microstructurally complex material indicates thermogravimetric analysis could be an important tool for understanding environmental effects in ceramic composites with reactive interfaces, Mass losses were linear within the first 1.08 x 10(4) s to 2.16 x 10(4) s between 1073 and 1373 K and between 3.1 x 10(2) and 2.5 x 10(3) Pa O-2. Calculated reaction orders with respect to O-2 were between 0.5 and 1.0 at 1373 K, and activation energies were about 50 kJ . mol(-1). Analysis of the kinetic data and estimates of gas boundary layer thickness suggest the mechanism for the C-interface oxidation involved reaction control, but the possibility of diffusion control for some conditions cannot be ruled out. RP Windisch, CF (reprint author), PACIFIC NW LAB, POB 999, RICHLAND, WA 99352 USA. OI Henager, Chuck/0000-0002-8600-6803 NR 15 TC 38 Z9 39 U1 1 U2 2 PU AMER CERAMIC SOC PI WESTERVILLE PA 735 CERAMIC PLACE, PO BOX 6136, WESTERVILLE, OH 43081-6136 SN 0002-7820 J9 J AM CERAM SOC JI J. Am. Ceram. Soc. PD MAR PY 1997 VL 80 IS 3 BP 569 EP 574 PG 6 WC Materials Science, Ceramics SC Materials Science GA WQ570 UT WOS:A1997WQ57000005 ER PT J AU Sun, EY Lin, HT Brennan, JJ AF Sun, EY Lin, HT Brennan, JJ TI Intermediate-temperature environmental effects on boron nitride-coated silicon carbide-fiber-reinforced glass-ceramic composites SO JOURNAL OF THE AMERICAN CERAMIC SOCIETY LA English DT Article; Proceedings Paper CT 1996 Conference on Composites, Advanced Ceramics, Materials and Structures CY JAN, 1996 CL COCOA BEACH, FL ID MATRIX COMPOSITES; CHEMISTRY AB The environmental effects on the mechanical properties of fiber-reinforced composites at intermediate temperatures were investigated by conducting flexural static-fatigue experiments in air at 600 degrees and 950 degrees C, The material that was studied was a silicon carbide/boron nitride (SIC/BN) dual-coated Nicalon-fiber-reinforced barium magnesium aluminosilicate glass-ceramic. Comparable time-dependent failure responses were found at 600 degrees and 950 degrees C when the maximum tensile stress applied in the bend bar was > 60% of the room-temperature ultimate flexural strength of as-received materials. At both temperatures, the materials survived 500 h fatigue tests at lower stress levels, Among the samples that survived the 500 h fatigue tests, a 20% degradation in the room-temperature flexural strength was measured in samples tested at 600 degrees C, whereas no degradation was observed for the samples tested at 950 degrees C. Microstructure and chemistry studies revealed interfacial oxidation in the samples that were fatigued at 600 degrees C. The growth rate of the Si-C-O fiber oxidation product at 600 degrees C was not sufficient to seal the stress-induced cracks, so that the interior of the material was oxidized and resulted in a strength degradation and less fibrous fracture, In contrast, the interior of the material remained intact at 950 degrees C because of crack sealing by rapid silicate formation, and strength/toughness of the composite was maintained, Also, at 600 degrees C, BN oxidized via volatilization, because no borosilicate was formed. C1 UNITED TECHNOL RES CTR,E HARTFORD,CT 06108. RP Sun, EY (reprint author), OAK RIDGE NATL LAB,OAK RIDGE,TN 37831, USA. NR 19 TC 33 Z9 34 U1 2 U2 8 PU AMER CERAMIC SOC PI WESTERVILLE PA 735 CERAMIC PLACE, PO BOX 6136, WESTERVILLE, OH 43081-6136 SN 0002-7820 J9 J AM CERAM SOC JI J. Am. Ceram. Soc. PD MAR PY 1997 VL 80 IS 3 BP 609 EP 614 PG 6 WC Materials Science, Ceramics SC Materials Science GA WQ570 UT WOS:A1997WQ57000012 ER PT J AU Suematsu, H Mitomo, M Mitchell, TE Petrovic, JJ Fukunaga, O Ohashi, N AF Suematsu, H Mitomo, M Mitchell, TE Petrovic, JJ Fukunaga, O Ohashi, N TI The alpha-beta transformation in silicon nitride single crystals SO JOURNAL OF THE AMERICAN CERAMIC SOCIETY LA English DT Article ID PHASE-TRANSFORMATION AB Single crystals of alpha-Si3N4 were annealed at 2000 degrees-2150 degrees C. The beta phase was detected after annealing at 2150 degrees C only when the crystals were surrounded by MgO . 3Al(2)O(3) or Y2O3 powders. On the other hand, no evidence of the alpha-beta transformation was found when the crystals were annealed without additives. The solution-precipitation mechanism was concluded to be the dominant factor in the alpha-beta transformation of Si3N4. C1 NATL INST RES INORGAN MAT,IBARAKI,OSAKA 305,JAPAN. LOS ALAMOS NATL LAB,CTR MAT SCI,LOS ALAMOS,NM 87545. TOKYO INST TECHNOL,DEPT ENGN,TOKYO 152,JAPAN. NR 22 TC 45 Z9 45 U1 1 U2 8 PU AMER CERAMIC SOC PI WESTERVILLE PA 735 CERAMIC PLACE, PO BOX 6136, WESTERVILLE, OH 43081-6136 SN 0002-7820 J9 J AM CERAM SOC JI J. Am. Ceram. Soc. PD MAR PY 1997 VL 80 IS 3 BP 615 EP 620 PG 6 WC Materials Science, Ceramics SC Materials Science GA WQ570 UT WOS:A1997WQ57000013 ER PT J AU Warren, WL Tuttle, BA Rong, FC Gerardi, GJ Poindexter, EH AF Warren, WL Tuttle, BA Rong, FC Gerardi, GJ Poindexter, EH TI Electron paramagnetic resonance investigation of acceptor centers in Pb(Zr,Ti)O-3 ceramics SO JOURNAL OF THE AMERICAN CERAMIC SOCIETY LA English DT Article ID FERROELECTRIC THIN-FILMS; SPIN-RESONANCE; BATIO3; TRANSITION; ZEOLITES; DEFECTS; STATES; ESR AB The nature of extrinsic point defects in lead zirconate titanate (PZT) ceramics of various compositions prepared by solution chemistry has been explored. Using electron paramagnetic resonance (EPR), several impurity sites have been identified in the as-received materials, which include FE(3+)-oxygen vacancy (V-O(..)) complier and isolated Cu2+ ions; both of these ions are incorporated into the lattice by replacing the Ti (Zr) ion. A Fe3+-V-O(..) complex serves as a sensitive probe of the local crystalline field environment of the ceramic; the symmetry of this defect is roughly correlated with its phase diagram as the composition is varied from PbTiO3 to PbZrO3. The Fe3+-V-O(..) complex experiences tetragonal, rhombic, or orthorhombic symmetry as the composition is varied from PbTiO, to PbZrO3. As the composition of the Cu2+ ion is varied, it appears as though the addition of Zr, and nor necessarily a change in phase, is largely responsible in determining the local environment of this acceptor impurity. Also, the Cu2+ resonance parameters weakly reflect the relative Ti-O (Zr-O) bond covalency in the perovskite lattice. C1 USA,RES LAB,FT MONMOUTH,NJ 07703. RP Warren, WL (reprint author), SANDIA NATL LABS,POB 5800,ALBUQUERQUE,NM 87185, USA. NR 45 TC 37 Z9 37 U1 0 U2 11 PU AMER CERAMIC SOC PI WESTERVILLE PA 735 CERAMIC PLACE, PO BOX 6136, WESTERVILLE, OH 43081-6136 SN 0002-7820 J9 J AM CERAM SOC JI J. Am. Ceram. Soc. PD MAR PY 1997 VL 80 IS 3 BP 680 EP 684 PG 5 WC Materials Science, Ceramics SC Materials Science GA WQ570 UT WOS:A1997WQ57000021 ER PT J AU Keblinski, P Phillpot, SR Wolf, D Gleiter, H AF Keblinski, P Phillpot, SR Wolf, D Gleiter, H TI On the thermodynamic stability of amorphous intergranular films in covalent materials SO JOURNAL OF THE AMERICAN CERAMIC SOCIETY LA English DT Article ID MOLECULAR-DYNAMICS METHOD; GRAIN-BOUNDARIES; ENERGY CORRELATION; SYMMETRICAL TILT; SILICON-NITRIDE; TIGHT-BINDING; THICKNESS; SIMULATION; RELAXATION; PHASES AB The thermodynamic origin, structure, and stability of the thin amorphous films commonly found in grain boundaries in covalent ceramics are investigated by molecular-dynamics simulation, To focus on the purely thermodynamic aspects, any kinetic effects associated with impurity-controlled interface chemistry are excluded by investigating pure silicon (described by the Stillinger-Weber three-body potential), For this single-component covalent model material, we demonstrate that all high-energy boundaries exhibit a universal amorphous structure, with a width of similar to 0.25 nm, whereas low-energy boundaries are crystalline and much sharper, We also demonstrate that introduction of an amorphous film into a crystalline interface lowers the excess energy to a level similar to the energy of two bulk crystal-amorphous interfaces, The competition between a narrow crystalline boundary structure and a wider amorphous boundary structure is shown to be governed by the relative excess energies of the atoms in the grain boundaries and in the bulk amorphous phase, These observations suggest that, in principle, amorphous grain-boundary films do not require impurities for their stabilization and that, as first proposed by Clarke, an equilibrium grain-boundary phase of uniform thickness can be the result of purely thermodynamic rather than kinetic factors. C1 FORSCHUNGSZENTRUM KARLSRUHE, D-76021 KARLSRUHE, GERMANY. RP Keblinski, P (reprint author), ARGONNE NATL LAB, DIV MAT SCI, 9700 S CASS AVE, ARGONNE, IL 60439 USA. RI Phillpot, Simon/J-9117-2012; OI Phillpot, Simon/0000-0002-7774-6535 NR 36 TC 53 Z9 53 U1 4 U2 15 PU WILEY-BLACKWELL PI MALDEN PA COMMERCE PLACE, 350 MAIN ST, MALDEN 02148, MA USA SN 0002-7820 J9 J AM CERAM SOC JI J. Am. Ceram. Soc. PD MAR PY 1997 VL 80 IS 3 BP 717 EP 732 PG 16 WC Materials Science, Ceramics SC Materials Science GA WQ570 UT WOS:A1997WQ57000026 ER PT J AU Krasopoulos, AV Li, J Josowicz, M Janata, J AF Krasopoulos, AV Li, J Josowicz, M Janata, J TI Rapid substitution of cold for aluminum metallization on integrated circuits SO JOURNAL OF THE ELECTROCHEMICAL SOCIETY LA English DT Article AB A rapid procedure for substitution of gold for aluminum metallization on integrated solid-state circuits, such as solid-state chemical multisensor chips, has been developed. The final product consists of original aluminum overlaid with nickel and gold, both deposited by an electroless process. The final metallization is chemically inert and the resistance of the contacts remains ohmic and unchanged from the original value. The substitution can be performed either at the wafer or at the chip level. After the plasma etching, the metallization process takes only 25 min. C1 PACIFIC NW LAB, RICHLAND, WA 99352 USA. NR 8 TC 3 Z9 3 U1 0 U2 0 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 1997 VL 144 IS 3 BP 1070 EP 1072 DI 10.1149/1.1837533 PG 3 WC Electrochemistry; Materials Science, Coatings & Films SC Electrochemistry; Materials Science GA WR237 UT WOS:A1997WR23700051 ER PT J AU deSouza, S Visco, SJ DeJonghe, LC AF deSouza, S Visco, SJ DeJonghe, LC TI Reduced-temperature solid oxide fuel cell based on YSZ thin-film electrolyte SO JOURNAL OF THE ELECTROCHEMICAL SOCIETY LA English DT Article AB A planar thin-film solid oxide fuel cell has been fabricated with an inexpensive, scalable, technique involving colloidal deposition of yttria-stabilized zirconia (YSZ) films on porous NiO-YSZ substrates, yielding solid oxide fuel cells capable of exceptional power density at operating temperatures of 700 to 800 degrees C. The thickness of the YSZ film deposited onto the porous substrate is approximately 10 mu m after sintering, and is well bonded to the NiO/YSZ substrate. Ni-YSZ/YSZ/LSM cells built with this technique have exhibited theoretical open-circuit potentials (OCPs), high current densities, and exceptionally good power densities of over 1900 mW/cm(2) at 800 degrees C. Electrochemical characterization of the cells indicates negligible losses across the Ni-YSZ/YSZ interface and minor polarization of the fuel electrode. Thin-film cells have been tested for long periods of time (over 700 h) and have been thermally cycled from 650 to 800 degrees C while demonstrating excellent stability over time. RP deSouza, S (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV MAT SCI,BERKELEY,CA 94720, USA. NR 7 TC 199 Z9 199 U1 7 U2 47 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 1997 VL 144 IS 3 BP L35 EP L37 DI 10.1149/1.1837484 PG 3 WC Electrochemistry; Materials Science, Coatings & Films SC Electrochemistry; Materials Science GA WR237 UT WOS:A1997WR23700002 ER PT J AU Cushing, CE AF Cushing, CE TI Organic matter dynamics in Rattlesnake Springs, Washington, USA SO JOURNAL OF THE NORTH AMERICAN BENTHOLOGICAL SOCIETY LA English DT Article ID COLD DESERT STREAMS; BENTHIC INSECTS C1 PACIFIC NW LAB, RICHLAND, WA 99352 USA. NR 16 TC 12 Z9 12 U1 0 U2 1 PU NORTH AMER BENTHOLOGICAL SOC PI LAWRENCE PA 1041 NEW HAMSPHIRE STREET, LAWRENCE, KS 66044 SN 0887-3593 J9 J N AM BENTHOL SOC JI J. N. Am. Benthol. Soc. PD MAR PY 1997 VL 16 IS 1 BP 39 EP 43 DI 10.2307/1468229 PG 5 WC Ecology; Marine & Freshwater Biology SC Environmental Sciences & Ecology; Marine & Freshwater Biology GA WM593 UT WOS:A1997WM59300009 ER PT J AU Mulholland, PJ AF Mulholland, PJ TI Organic matter dynamics in the West Fork of Walker Branch, Tennessee, USA SO JOURNAL OF THE NORTH AMERICAN BENTHOLOGICAL SOCIETY LA English DT Article ID WOODLAND STREAM; FOREST STREAM; PERIPHYTON; ECOSYSTEM; FLOW; METABOLISM; ROLES RP Mulholland, PJ (reprint author), OAK RIDGE NATL LAB,DIV ENVIRONM SCI,POB 2008,OAK RIDGE,TN 37831, USA. RI Mulholland, Patrick/C-3142-2012 NR 24 TC 15 Z9 15 U1 0 U2 8 PU NORTH AMER BENTHOLOGICAL SOC PI LAWRENCE PA 1041 NEW HAMSPHIRE STREET, LAWRENCE, KS 66044 SN 0887-3593 J9 J N AM BENTHOL SOC JI J. N. Am. Benthol. Soc. PD MAR PY 1997 VL 16 IS 1 BP 61 EP 67 DI 10.2307/1468235 PG 7 WC Ecology; Marine & Freshwater Biology SC Environmental Sciences & Ecology; Marine & Freshwater Biology GA WM593 UT WOS:A1997WM59300015 ER PT J AU Jones, JB AF Jones, JB TI Benthic organic matter storage in streams: Influence of detrital import and export, retention mechanisms, and climate SO JOURNAL OF THE NORTH AMERICAN BENTHOLOGICAL SOCIETY LA English DT Article ID GRADIENT HEADWATER STREAMS; WOODLAND STREAM; DEBRIS DAMS; PARTICULATE MATTER; ECOSYSTEM DYNAMICS; MOUNTAIN STREAM; RIVER CONTINUUM; DESERT STREAM; WOODY DEBRIS; HABITAT C1 OAK RIDGE NATL LAB,DIV ENVIRONM SCI,OAK RIDGE,TN 37831. NR 48 TC 59 Z9 63 U1 1 U2 11 PU NORTH AMER BENTHOLOGICAL SOC PI LAWRENCE PA 1041 NEW HAMSPHIRE STREET, LAWRENCE, KS 66044 SN 0887-3593 J9 J N AM BENTHOL SOC JI J. N. Am. Benthol. Soc. PD MAR PY 1997 VL 16 IS 1 BP 109 EP 119 DI 10.2307/1468243 PG 11 WC Ecology; Marine & Freshwater Biology SC Environmental Sciences & Ecology; Marine & Freshwater Biology GA WM593 UT WOS:A1997WM59300023 ER PT J AU Mulholland, PJ AF Mulholland, PJ TI Dissolved organic matter concentration and flux in streams SO JOURNAL OF THE NORTH AMERICAN BENTHOLOGICAL SOCIETY LA English DT Article ID BOREAL FOREST WATERSHEDS; RIVER CONTINUUM; CARBON EXPORT; MOUNTAIN STREAMS; BLACKWATER RIVER; HUMIC SUBSTANCES; DYNAMICS; GROUNDWATER; TRANSPORT; ECOSYSTEMS RP Mulholland, PJ (reprint author), OAK RIDGE NATL LAB, DIV ENVIRONM SCI, POB 2008, OAK RIDGE, TN 37831 USA. RI Mulholland, Patrick/C-3142-2012 NR 43 TC 57 Z9 57 U1 0 U2 21 PU NORTH AMER BENTHOLOGICAL SOC PI LAWRENCE PA 1041 NEW HAMSPHIRE STREET, LAWRENCE, KS 66044 USA SN 0887-3593 J9 J N AM BENTHOL SOC JI J. N. Am. Benthol. Soc. PD MAR PY 1997 VL 16 IS 1 BP 131 EP 141 DI 10.2307/1468246 PG 11 WC Ecology; Marine & Freshwater Biology SC Environmental Sciences & Ecology; Marine & Freshwater Biology GA WM593 UT WOS:A1997WM59300026 ER PT J AU Kaushik, S AF Kaushik, S TI Vector Fresnel equations and Airy formula for one-dimensional multilayer and surface-relief gratings SO JOURNAL OF THE OPTICAL SOCIETY OF AMERICA A-OPTICS IMAGE SCIENCE AND VISION LA English DT Article ID COUPLED-WAVE ANALYSIS; LAMELLAR DIFFRACTION GRATINGS; MATRIX PROPAGATION ALGORITHM; EFFICIENT IMPLEMENTATION; DIELECTRIC GRATINGS; PROFILES AB A simple and intuitive formalism is presented to describe diffraction in multilayered periodic structures. A modal theory of diffraction is used to show how well-known results from scalar analysis (wave propagation in homogeneous layered media) can readily be generalized to vector problems. Specifically, the following results are derived: (1) generalized Fresnel equations appropriate for reflection and transmission from an infinitely thick grating, (2) a generalized equation for power conservation for diffraction gratings, (3) a generalized Airy formula for thin film to describe reflection and transmission of light through a lamellar grating, and (4) a matrix propagation method akin to that used to calculate reflection and transmission of multilayer thin films. Some numerical results are also presented to illustrate the applications of this research and its relationship to previous modal theories. (C) 1997 Optical Society of America. RP Kaushik, S (reprint author), SANDIA NATL LABS,POB 5800,ALBUQUERQUE,NM 87185, USA. NR 32 TC 12 Z9 12 U1 0 U2 1 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 SN 0740-3232 J9 J OPT SOC AM A JI J. Opt. Soc. Am. A-Opt. Image Sci. Vis. PD MAR PY 1997 VL 14 IS 3 BP 596 EP 609 DI 10.1364/JOSAA.14.000596 PG 14 WC Optics SC Optics GA WK732 UT WOS:A1997WK73200008 ER PT J AU Burtsev, S Kaup, DJ AF Burtsev, S Kaup, DJ TI Effective control of a soliton by sliding-frequency guiding filters SO JOURNAL OF THE OPTICAL SOCIETY OF AMERICA B-OPTICAL PHYSICS LA English DT Article ID OPTICAL FIBERS; TRANSMISSION; SUPPRESSION AB A singular perturbation method is used to analyze the effect of sliding-frequency guiding filters on an optical soliton, which has been proposed to be used as a bit carrier in fiber-optics communication systems. We find that there is a broad range of physical parameters, only inside of which would the sliding-frequency filter scheme operate stably. The lower limit (in soliton energy) of this parameter regime was found earlier by Mollenauer et al. [Opt. Lett. 17, 1575 (1992)] and by Kodama et al. [Opt. Lett. 18, 1311 (1993)] and is determined by whether the soliton will continue to stay in synchronization with the array of filters. The upper limit is determined when the comoving dispersive waves that are continually being generated by the filtering are no longer decaying and instead start to grow and generate, finally, a secondary soliton. This upper limit was discovered recently in both experiments and numerical simulations by Mamyshev and Mollenauer [Opt. Lett. 15, 2083 (1994)]. We have found a simple analytical estimate of this upper limit by the use of a singular perturbation method. Our analytical results agree well with the numerical and experimental findings of Mamyshev and Mollenauer. (C) 1997 Optical Society of America. C1 LOS ALAMOS NATL LAB,CTR NONLINEAR STUDIES,LOS ALAMOS,NM 87545. CLARKSON UNIV,DEPT PHYS,INST NONLINEAR STUDIES,POTSDAM,NY 13699. CLARKSON UNIV,DEPT MATH,POTSDAM,NY 13699. RP Burtsev, S (reprint author), LOS ALAMOS NATL LAB,DIV THEORET,LOS ALAMOS,NM 87545, USA. NR 16 TC 10 Z9 10 U1 0 U2 0 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 SN 0740-3224 J9 J OPT SOC AM B JI J. Opt. Soc. Am. B-Opt. Phys. PD MAR PY 1997 VL 14 IS 3 BP 627 EP 635 DI 10.1364/JOSAB.14.000627 PG 9 WC Optics SC Optics GA WM652 UT WOS:A1997WM65200019 ER PT J AU Gao, Y Kim, YJ Chambers, SA Bai, G AF Gao, Y Kim, YJ Chambers, SA Bai, G TI Synthesis of epitaxial films of Fe3O4 and alpha-Fe2O3 with various low-index orientations by oxygen-plasma-assisted molecular beam epitaxy SO JOURNAL OF VACUUM SCIENCE & TECHNOLOGY A LA English DT Article ID IRON-OXIDE FILMS; SCANNING-TUNNELING-MICROSCOPY; SURFACE-STRUCTURE; THIN-FILMS; GROWTH; PT(111); OXIDATION; CHEMISORPTION; ALPHA-AL2O3; ADSORPTION AB Epitaxial thin films of pure-phase Fe3O4(110), Fe3O4(111), alpha-Fe2O3(11 (2) over bar 0), and alpha-Fe2O3(1 (1) over bar 02) have been grown on MgO(110), alpha-Al2O3(0001), alpha-Al2O3(11 (2) over bar 0), and alpha-Al2O3(1 (1) over bar 02) substrates, respectively, by molecular beam epitaxy using an elemental Fe source and an electron cyclotron resonance oxygen plasma source. Characterization of the crystal structures, chemical states, and epitaxial relationships was carried out using a variety of techniques, including in situ reflection high-energy electron diffraction (RHEED), low-energy electron diffraction, x-ray photoelectron spectroscopy/diffraction, and ex situ x-ray reflectivity and diffraction. Real-time RHEED reveals that Fe3O4 growth on MgO appears in a step-flow fashion, whereas the growth of Fe3O4(111) on alpha-Al2O3(0001) occurs initially by island formation, and then island coalescence. However, the growth of alpha-Fe2O3 on alpha-Al2O3 appears to follow an intermediate growth mode. The formation of pure-phase films is controlled largely by oxygen partial pressure, plasma power, and growth rate, but appears to be independent of growth temperature, at least from 250 to 550 degrees C. The present study demonstrates that selective growth of pure-phase iron oxides with various low-index orientations can be achieved by controlling the growth conditions and selecting suitable substrates. (C) 1997 American Vacuum Society. C1 ARGONNE NATL LAB, DIV MAT SCI, ARGONNE, IL 60439 USA. RP Gao, Y (reprint author), PACIFIC NW LAB, ENVIRONM MOL SCI LAB, POB 999, RICHLAND, WA 99352 USA. NR 43 TC 70 Z9 70 U1 1 U2 18 PU A V S AMER INST PHYSICS PI MELVILLE PA STE 1 NO 1, 2 HUNTINGTON QUADRANGLE, MELVILLE, NY 11747-4502 USA SN 0734-2101 EI 1520-8559 J9 J VAC SCI TECHNOL A JI J. Vac. Sci. Technol. A PD MAR-APR PY 1997 VL 15 IS 2 BP 332 EP 339 DI 10.1116/1.580488 PG 8 WC Materials Science, Coatings & Films; Physics, Applied SC Materials Science; Physics GA WP127 UT WOS:A1997WP12700020 ER PT J AU Maya, L Vallet, CE Lee, YH AF Maya, L Vallet, CE Lee, YH TI Sputtered gold films for surface-enhanced Raman scattering SO JOURNAL OF VACUUM SCIENCE & TECHNOLOGY A-VACUUM SURFACES AND FILMS LA English DT Article ID SILVER ELECTRODE; COLLOID MONOLAYERS; SPECTROMETRY; PYRIDINE; SPECTRA AB Sputtered gold films in a pure form or as nanocomposites in silica or silicon nitride were screened for surface-enhanced Raman scattering (SERS) activity using Rhodamine 6G as a probe. The films were prepared by sputtering pure gold or solidified Au-Si alloys in plasmas generated in a de glow discharge apparatus. The plasmas were produced with argon, nitrogen, or argon-oxygen as the sputtering gas to directly deposit gold films or in the latter case a Sold oxide intermediate. The alloys produce nanocomposite films in a silicon nitride or silica matrix depending on the plasma gas. SERS activity was detected in some of the films thus leading to a search for the critical parameters that controlled this phenomenon. The films were characterized by profilometry, x-ray diffraction, and atomic force microscopy. SERS activity was found to be correlated to crystallite size in the 10-25 nm range and to roughness larger than 15 nm, and it was independent of film thickness. Sputtered gold films, particularly those containing the gold as a nanocomposite in silica are attractive media for SERS because of excellent adherence, ruggedness, and simplicity in preparation. (C) 1997 American Vacuum Society. RP Maya, L (reprint author), OAK RIDGE NATL LAB,DIV CHEM & ANALYT SCI,OAK RIDGE,TN 37831, USA. NR 20 TC 27 Z9 27 U1 3 U2 18 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0734-2101 J9 J VAC SCI TECHNOL A JI J. Vac. Sci. Technol. A-Vac. Surf. Films PD MAR-APR PY 1997 VL 15 IS 2 BP 238 EP 242 DI 10.1116/1.580518 PG 5 WC Materials Science, Coatings & Films; Physics, Applied SC Materials Science; Physics GA WP127 UT WOS:A1997WP12700005 ER PT J AU Malhotra, SG Rek, ZU Yalisove, SM Bilello, JC AF Malhotra, SG Rek, ZU Yalisove, SM Bilello, JC TI Strain gradients and normal stresses in textured Mo thin films SO JOURNAL OF VACUUM SCIENCE & TECHNOLOGY A-VACUUM SURFACES AND FILMS LA English DT Article ID X-RAY-DIFFRACTION; GRAIN-GROWTH; MECHANICAL-PROPERTIES; MOLYBDENUM FILMS; ALUMINUM FILMS; MICROSTRUCTURE; SILICON; TOPOGRAPHY; COATINGS; OXYGEN AB The high-resolution x-ray-diffraction technique was used to explore strain variations in sputtered Mo films with thicknesses of 170, 260, and 800 nm that possess a (110) out-of-plane texture. The strains in crystallographic planes perpendicular to the surface of each film were found to be nominally constant and compressive at all x-ray penetration depths. Near the surface of each him, the inclined-plane strains were compressive, and then relaxed as the penetration depths approached each entire film thickness. The strain tensor in a laboratory reference frame for each film, as a function of penetration depth, revealed that the normal strain epsilon(zz) was tensile near the surface of each film, and then relaxed to a nominally constant value as the penetration depths approached the entire film thickness. The penetration depth over which the normal strain decayed to a nominally constant value increased as the total film thickness increased. A consequence of the large normal strains near the free surface of each film is that the corresponding normal stresses were nonzero. (C) 1997 American Vacuum Society. C1 UNIV MICHIGAN,DEPT MAT SCI & ENGN,ANN ARBOR,MI 48109. STANFORD SYNCHROTRON RADIAT LAB,STANFORD,CA 94395. NR 51 TC 17 Z9 17 U1 1 U2 5 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0734-2101 J9 J VAC SCI TECHNOL A JI J. Vac. Sci. Technol. A-Vac. Surf. Films PD MAR-APR PY 1997 VL 15 IS 2 BP 345 EP 352 DI 10.1116/1.580490 PG 8 WC Materials Science, Coatings & Films; Physics, Applied SC Materials Science; Physics GA WP127 UT WOS:A1997WP12700022 ER PT J AU Ruvimov, S LilientalWeber, Z Bourret, ED Swider, W Washburn, J Duxstad, KJ Haller, EE AF Ruvimov, S LilientalWeber, Z Bourret, ED Swider, W Washburn, J Duxstad, KJ Haller, EE TI Structural characterization of thin Ni films deposited on (001) ZnSe SO JOURNAL OF VACUUM SCIENCE & TECHNOLOGY B LA English DT Article ID OHMIC CONTACTS AB Transmission electron microscopy and x-ray diffraction have been used to study the evolution of the structure during thermal annealing of thin Ni films deposited on ZnSe. 30-nm-thick Ni layers were deposited, and then annealed at temperatures ranging between 300 and 475 degrees C for 0.5 or 1 h in a N-2 atmosphere. The as-deposited Ni layer was found to be polycrystalline. Annealing results in Ni diffusion into the ZnSe and outdiffusion of the Zn and Se toward the sample surface. The Se reacts with Ni to form Ni,Se phases at the Ni-ZnSe interface and in the Ni layer. Formation of a metastable tetragonal NixSe phase detected after annealing at 425 degrees C was found to be suppressed at higher annealing temperatures. The cubic NixSe phase (x similar to 1) with a = 4.23 Angstrom dominates in the samples after annealing at temperatures above 425 degrees C. Both phases are crystallographically oriented with respect to the matrix so as to provide the best lattice match with the ZnSe. (C) 1997 American Vacuum Society. C1 UNIV CALIF BERKELEY, DEPT MAT SCI & MINERAL ENGN, BERKELEY, CA 94720 USA. RP UNIV CALIF BERKELEY, LAWRENCE BERKELEY LAB, DIV MAT SCI, MS 63-203, BERKELEY, CA 94720 USA. RI Liliental-Weber, Zuzanna/H-8006-2012 NR 20 TC 2 Z9 2 U1 0 U2 0 PU A V S AMER INST PHYSICS PI MELVILLE PA STE 1 NO 1, 2 HUNTINGTON QUADRANGLE, MELVILLE, NY 11747-4502 USA SN 1071-1023 J9 J VAC SCI TECHNOL B JI J. Vac. Sci. Technol. B PD MAR-APR PY 1997 VL 15 IS 2 BP 247 EP 251 DI 10.1116/1.589273 PG 5 WC Engineering, Electrical & Electronic; Nanoscience & Nanotechnology; Physics, Applied SC Engineering; Science & Technology - Other Topics; Physics GA WU267 UT WOS:A1997WU26700013 ER PT J AU Chakhovskoi, AG Hunt, CE Malinowski, ME Felter, TE Talin, AA AF Chakhovskoi, AG Hunt, CE Malinowski, ME Felter, TE Talin, AA TI Characterization of novel powder and thin film RGB phosphors for field emission display application SO JOURNAL OF VACUUM SCIENCE & TECHNOLOGY B LA English DT Article; Proceedings Paper CT 9th International Vacuum Microelectronics Conference(IVMC'96) CY JUL 07-12, 1996 CL ST PETERSBURG, RUSSIA SP IEEE, Electron Device Soc, Russian Acad Sci, Acad Nat Sci, Inst Radio Engn & Electr, Moscow, Bonch Bruevich Univ Telecommun, St Petersburg, Ioffe Phys Tech Inst, St Petersburg, Russian Fund Basic Res, Russian Minist Sci, St Petersburg City Adm & City Legislat Assembly, US Adv Res Projects Agcy, USA, European Res Off, USAF, European Off Aerosp Res & Dev, USN, Off Naval Res, Europe AB The spectral response, brightness, and outgassing characteristics of new, low-voltage phosphors for application in field emission flat panel displays, are presented. The tested phosphor materials include combustion synthesized powders and thin films prepared by rf diode or magnetron sputtering, laser ablation, and molecular beam epitaxy. These cathodoluminescent materials are tested with e-beam excitation at currents up to 50 mu A within the 200-2000 V (e.g., ''low-voltage'') and 3-8 kV (e.g., ''medium-voltage'') ranges. The spectral coordinates are compared to commercial low-voltage phosphors. Phosphor outgassing, as a function of time, is measured with a residual gas analyzer at fixed 50 mu A beam current in the low-voltage range. We find that levels of outgassing stabilize to low values after the first few hours of excitation. The desorption rates measured for powder phosphor layers with different thicknesses are compared to desorption from thin films. (C) 1997 American Vacuum Society. C1 SANDIA NATL LABS,LIVERMORE,CA 94551. RP Chakhovskoi, AG (reprint author), UNIV CALIF DAVIS,DEPT ELECT & COMP ENGN,DAVIS,CA 95616, USA. NR 9 TC 25 Z9 25 U1 1 U2 3 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 J9 J VAC SCI TECHNOL B JI J. Vac. Sci. Technol. B PD MAR-APR PY 1997 VL 15 IS 2 BP 507 EP 511 DI 10.1116/1.589281 PG 5 WC Engineering, Electrical & Electronic; Nanoscience & Nanotechnology; Physics, Applied SC Engineering; Science & Technology - Other Topics; Physics GA WU267 UT WOS:A1997WU26700065 ER PT J AU Goldman, D AF Goldman, D TI Estimating expected annual damage for levee retrofits SO JOURNAL OF WATER RESOURCES PLANNING AND MANAGEMENT-ASCE LA English DT Article ID FLOOD FREQUENCY ESTIMATION; UNCERTAINTIES AB The U.S. Army Corps of Engineers (USAGE) has instituted a new analysis methodology for estimating the expected annual damage (EAD) and resulting economic benefits accruing to proposed flood damage-reduction projects Although the methodology is new, it still, in effect, uses expected probability to estimate the frequency of flooding and EAD. The National Research Council (NRC) in a review of USACE's study of the American River levees stated that the use of expected probability results in significantly biased estimates of EAD. An alternative damage model to that proposed by NRC is used to show that expected probability leads to an unbiased estimate of EAD. The damage model proposed requires that an unbiased estimate of damage results when applied to many projects. A simulation study demonstrates that EAD estimated with expected probability is unbiased, whereas the NRC's recommended estimator is biased. RP Goldman, D (reprint author), LAWRENCE LIVERMORE NATL LAB,HYDROL ENGN CTR,DAVIS,CA 95616, USA. NR 13 TC 13 Z9 17 U1 0 U2 0 PU ASCE-AMER SOC CIVIL ENGINEERS PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2398 SN 0733-9496 J9 J WATER RES PL-ASCE JI J. Water Resour. Plan. Manage.-ASCE PD MAR-APR PY 1997 VL 123 IS 2 BP 89 EP 94 DI 10.1061/(ASCE)0733-9496(1997)123:2(89) PG 6 WC Engineering, Civil; Water Resources SC Engineering; Water Resources GA WK073 UT WOS:A1997WK07300004 ER PT J AU Paul, B Scherer, JJ OKeefe, A Saykally, RJ AF Paul, B Scherer, JJ OKeefe, A Saykally, RJ TI Cavity ringdown measures trace concentrations SO LASER FOCUS WORLD LA English DT Article ID LASER-ABSORPTION SPECTROSCOPY C1 SANDIA NATL LABS,COMBUST RES FACIL,LIVERMORE,CA 94551. LOS GATOS RES,MT VIEW,CA 94043. RP Paul, B (reprint author), UNIV CALIF BERKELEY,DEPT CHEM,BERKELEY,CA 94720, USA. NR 13 TC 6 Z9 6 U1 0 U2 0 PU PENNWELL PUBL CO PI NASHUA PA 5TH FLOOR TEN TARA BOULEVARD, NASHUA, NH 03062-2801 SN 0740-2511 J9 LASER FOCUS WORLD JI Laser Focus World PD MAR PY 1997 VL 33 IS 3 BP 71 EP & PG 7 WC Optics SC Optics GA WN609 UT WOS:A1997WN60900027 ER PT J AU Hino, T Prausnitz, JM AF Hino, T Prausnitz, JM TI A perturbed hard-sphere-chain equation of state for nematic liquid crystals and their mixtures with polymers SO LIQUID CRYSTALS LA English DT Article ID ISOTROPIC PHASE-TRANSITION; MEAN FIELD-THEORY; DIAGRAMS; BEHAVIOR; SYSTEMS; MODEL; EBBA AB A perturbed hard-sphere-chain (PHSC) equation of state is presented to compute nematic-isotropic equilibria for thermotropic liquid crystals, including mixtures. The equation of state consists of an isotropic term and an anisotropic term given by the Maier-Saupe theory whose contribution disappears in the isotropic phase. The isotropic contribution is the recently presented PHSC equation of state for normal fluids and polymers which uses a reference equation of state for athermal hard-sphere chains and a perturbation theory for the square-well fluid of variable well width. The PHSC equation of state gives excellent correlations of pure-component pressure-volume-temperature data in the isotropic region and, combined with the Maier-Saupe theory, correlates the dependence of nematic-isotropic transition temperature on the pressure. Theory also predicts a nematic-isotropic biphasic region and liquid-liquid phase separation in a temperature-composition diagram of binary mixtures containing a nematic liquid crystal and a normal fluid or polymer. Theory and experiment show good agreement for pure fluids as well as for mixtures. C1 UNIV CALIF BERKELEY,DEPT CHEM ENGN,BERKELEY,CA 94720. UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV CHEM SCI,BERKELEY,CA 94720. NR 33 TC 5 Z9 5 U1 0 U2 3 PU TAYLOR & FRANCIS LTD PI LONDON PA ONE GUNPOWDER SQUARE, LONDON, ENGLAND EC4A 3DE SN 0267-8292 J9 LIQ CRYST JI Liq. Cryst. PD MAR PY 1997 VL 22 IS 3 BP 317 EP 326 PG 10 WC Chemistry, Multidisciplinary; Crystallography; Materials Science, Multidisciplinary SC Chemistry; Crystallography; Materials Science GA WK276 UT WOS:A1997WK27600013 ER PT J AU Newman, DE Watts, C Sumpter, BG Noid, DW AF Newman, DE Watts, C Sumpter, BG Noid, DW TI On the determination and ramifications of chaos in manybody systems: A model study of polyethylene SO MACROMOLECULAR THEORY AND SIMULATIONS LA English DT Article ID NOISE-REDUCTION METHOD; MOLECULAR-DYNAMICS SIMULATIONS; TIME-SERIES; STRANGE ATTRACTORS; LIAPUNOV EXPONENTS; DIMENSION; EQUATIONS AB Computational methods for elucidating information related to the dynamical behavior of multidimensional systems are presented and applied in the area of macromolecular dynamics. Results indicate that the dimensionality of chaotic dynamics for a model of polyethylene can only be characterized for a very narrow range of extremely low temperature (0-2 K). These results provide evidence that suggests the dynamics of this system are completely chaotic at temperatures as low as 10 K. The preponderance of increasing density of low frequency floppy vibrational modes in large molecular systems provides a facile mechanism for the onset of global chaos. Ramifications of such global chaos to the accurate modeling and simulation of macromolecular dynamics is discussed. C1 OAK RIDGE NATL LAB,DIV FUS ENERGY,OAK RIDGE,TN 37831. AUBURN UNIV,DEPT PHYS,ALLISON LAB 206,AUBURN,AL 36849. RP Newman, DE (reprint author), OAK RIDGE NATL LAB,DIV CHEM & ANALYT SCI,OAK RIDGE,TN 37831, USA. RI Sumpter, Bobby/C-9459-2013 OI Sumpter, Bobby/0000-0001-6341-0355 NR 51 TC 8 Z9 8 U1 0 U2 2 PU HUTHIG & WEPF VERLAG PI BASEL PA AUF DEM WOLF 4, CH-4052 BASEL, SWITZERLAND SN 1022-1344 J9 MACROMOL THEOR SIMUL JI Macromol. Theory Simul. PD MAR PY 1997 VL 6 IS 2 BP 577 EP 590 DI 10.1002/mats.1997.040060217 PG 14 WC Polymer Science SC Polymer Science GA WN903 UT WOS:A1997WN90300017 ER PT J AU Zhou, XL Mopper, K AF Zhou, XL Mopper, K TI Photochemical production of low-molecular-weight carbonyl compounds in seawater and surface microlayer and their air-sea exchange SO MARINE CHEMISTRY LA English DT Article; Proceedings Paper CT Special Symposium on Modern Chemical and Biological Oceanography: The Influence of Peter J Wangersky CY JUL 28-29, 1994 CL HALIFAX, CANADA DE carbonyl; photoproduction; surface microlayer; seawater; air-sea exchange ID NATURAL-WATERS; FLUX; FORMALDEHYDE; INTERFACE; METALS; GASES; FATE; UV AB Coastal and oceanic surface microlayer samples were collected using a stainless steel screen, along with subsurface bulk seawater, and were analyzed for low-molecular-weight (LMW) carbonyl compounds, including formaldehyde, acetaldehyde, propanal, glyoxal, methylglyoxal, glyoxylic acid and pyruvic acid. The enrichment factor in surface microlayer compared to corresponding subsurface seawater ranged from 1.2 to 21. A time-series measurement at a coastal site showed strong diurnal variations in concentrations of the LMW carbonyl compounds in the surface microlayer and in the enrichment factor, with maxima in the early afternoon and minima in the early morning. Exposure of samples to sunlight resulted in the higher yields of these compounds in the surface microlayer than in the bulk seawater, by a factor of 1.1-25, suggesting that the higher photoproduction rate of LMW carbonyl compounds in the surface microlayer accounts for the majority of the observed enrichment in these samples. Potential sinks include biological uptake and mixing. Air-sea exchange may be a source for soluble compounds and a sink for less soluble compounds. The enrichment of the LMW carbonyl in surface microlayer may alter their net air-sea exchange direction, e.g., from the ocean as a potential sink to a source for atmospheric acetaldehyde and acetone. The residence times of the LMW carbonyl compounds in the microlayer were estimated to be on the order of tens of seconds to minutes using a modified two-layer model. However, to maintain the observed microlayer enrichment factor, the residence time should be on the order of similar to 1 hour. This prolonged residence time may be due to organic enrichment in the surface microlayer ('organic film') which inhibited molecular transfer of carbonyl compounds into and out of the microlayer. The deviated behavior from model prediction may also be due to changes in the apparent partition coefficients of these species as a result of thier physical and chemical interactions with organic matrix in the surface microlayer. C1 BROOKHAVEN NATL LAB,ENVIRONM CHEM DIV,UPTON,NY 11973. WASHINGTON STATE UNIV,DEPT CHEM,PULLMAN,WA 99164. NR 32 TC 122 Z9 128 U1 4 U2 36 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0304-4203 J9 MAR CHEM JI Mar. Chem. PD MAR PY 1997 VL 56 IS 3-4 BP 201 EP 213 DI 10.1016/S0304-4203(96)00076-X PG 13 WC Chemistry, Multidisciplinary; Oceanography SC Chemistry; Oceanography GA WQ300 UT WOS:A1997WQ30000005 ER PT J AU Cleveland, L Little, EE Petty, JD Johnson, BT Lebo, JA Orazio, CE Dionne, J Crockett, A AF Cleveland, L Little, EE Petty, JD Johnson, BT Lebo, JA Orazio, CE Dionne, J Crockett, A TI Toxicological and chemical screening of Antarctica sediments: Use of whole sediment toxicity tests, Microtox, Mutatox and semipermeable membrane devices (SPMDs) SO MARINE POLLUTION BULLETIN LA English DT Article DE Antarctica; sediments; toxicity; SPMDs; uv radiation; PAHs; PCBs ID POLYCYCLIC AROMATIC-HYDROCARBONS; PHOTOINDUCED TOXICITY; SELENASTRUM-CAPRICORNUTUM; ORGANIC CONTAMINANTS; GREEN-ALGA; ANTHRACENE; RADIATION; BAY; GENOTOXICITY; BIOASSAY AB Eight whole sediment samples from Antarctica (four from Winter Quarters Bay and four from McMurdo Sound) were toxicologically and chemically evaluated, Also, the influence of ultraviolet radiation on the toxicity and bioavailability of contaminants associated with the sediment samples was assessed, The evaluations were accomplished by use of a 10-day whole sediment test with Leptocheirus plumulosus, Microtox(R), Mutatox(R) and semipermeable membrane devices (SPMDs), Winter Quarters Bay sediments contained about 250 ng g(-1) (dry weight) total PCBs and 20 mu g g(-1) total PAHs. These sediments elicited toxicity in the Microtox test and avoidance and inhibited burrowing in the L. plumulosus test, The McMurdo Sound sediment samples contained only trace amounts of PCBs and no PAHs, and were less toxic in both the L. plumulosus and Microtox tests compared to the Winter Quarters Bay sediments, The sediments from McMurdo Sound apparently contained some unidentified substance which was photolytically modified to a more toxic form, The photolytic modification of sediment-associated contaminants, coupled with the polar ozone hole and increased incidence of ultraviolet radiation could significantly increase hazards to Antarctic marine life. C1 NATL SCI FDN, OFF POLAR PROGRAMS, WASHINGTON, DC 20550 USA. IDAHO NATL ENGN LAB, IDAHO FALLS, ID 83415 USA. RP USDI, NBS, MIDWEST SCI CTR, 4200 NEW HAVEN RD, COLUMBIA, MO 65201 USA. NR 44 TC 29 Z9 29 U1 1 U2 6 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0025-326X EI 1879-3363 J9 MAR POLLUT BULL JI Mar. Pollut. Bull. PD MAR PY 1997 VL 34 IS 3 BP 194 EP 202 DI 10.1016/S0025-326X(96)00088-4 PG 9 WC Environmental Sciences; Marine & Freshwater Biology SC Environmental Sciences & Ecology; Marine & Freshwater Biology GA WY044 UT WOS:A1997WY04400017 ER PT J AU Deptula, A Lada, W Olczak, T Goretta, KC DiBartolomeo, A Casadio, S AF Deptula, A Lada, W Olczak, T Goretta, KC DiBartolomeo, A Casadio, S TI Sol-gel process for preparation of YBa2Cu4O8 from acidic acetates/ammonia/ascorbic acid systems SO MATERIALS RESEARCH BULLETIN LA English DT Article DE superconductors; sol-gel chemistry ID SUPERCONDUCTING YBA2CU4O8; OXYGEN-PRESSURE AB YBa2Cu4Ox sols were prepared by addition of ammonia to acidic acetate solutions of Y3+, Ba2+, and Cu2+. Ascorbic acid was added to part of the sol. The resultant sols were gelled to a shard or a coating by evaporation at 60 degrees C. Addition of ethanol to the sols facilitated formation of gel coatings, fabricated by a dipping technique, on Ag or glass or substrates. At 100 degrees C, gels formed in the presence of ascorbic acid were perfectly amorphous, in contrast to crystalline acetate gels. The quality of coatings prepared from ascorbate gels was superior to that of acetate gel coatings. Copyright (C) 1997 Elsevier Science Ltd. C1 INST NUCL CHEM & TECHNOL,PL-03195 WARSAW,POLAND. ARGONNE NATL LAB,DIV ENERGY TECHNOL,ARGONNE,IL 60439. CRE CASACCIA,ENEA,ROME,ITALY. NR 16 TC 7 Z9 7 U1 0 U2 2 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0025-5408 J9 MATER RES BULL JI Mater. Res. Bull. PD MAR PY 1997 VL 32 IS 3 BP 319 EP 325 DI 10.1016/S0025-5408(96)00191-2 PG 7 WC Materials Science, Multidisciplinary SC Materials Science GA WJ867 UT WOS:A1997WJ86700006 ER PT J AU Kumar, D Kalyanaraman, R Vispute, RD Narayan, J Christen, DK Klabunde, CE AF Kumar, D Kalyanaraman, R Vispute, RD Narayan, J Christen, DK Klabunde, CE TI Giant magnetoresistance and non-ohmic effects in La0.6Y0.07Ca0.33MnOx thin films SO MATERIALS SCIENCE AND ENGINEERING B-SOLID STATE MATERIALS FOR ADVANCED TECHNOLOGY LA English DT Article DE LYMCO thin films; magnetoresistance; non-ohmic effect ID CA-MN-O; SPIN STRUCTURE; RESISTIVITY; MULTILAYERS; OXIDE AB Transport, magnetoresistance and structural properties of La0.6Y0.07Ca0.33MnOx (LYCMO) thin films grown in situ by pulsed laser ablation have been studied. Transmission electron microscopy and X-ray diffraction measurements have shown that the LYCMO films grow epitaxially on (100) LaAlO3 substrates and are cubic with a lattice parameter of 0.3849 nm. The as-deposited films exhibited a metal-insulator transition at 130 K and a giant magnetoresistance at 125 K with a MR ratio (Delta R/R-H) of 1500% in 6 Tesla magnetic field. By subsequent annealing of LYCMO films at 900 degrees C for half an hour in an oxygen ambient, this MR ratio was improved to 3200% at 192 K in the presence of the same magnetic field. This value of the MR ratio is the highest so far reported in this temperature regime. We ascribe this colossal magnetoresistance to the improved magnetic exchange between Mn3+ and Mn4+ ions resulting from the suppressed separation between Mn-O layers caused by a smaller sized Y-cation. We also report a non-ohmic response in the LYCMO films which is observed only in the region of the resistance peak and lends support to a conduction mechanism in these materials based on spin-dependent scattering of electrons. (C) 1997 Elsevier Science S.A. C1 N CAROLINA STATE UNIV, DEPT MAT SCI & ENGN, RALEIGH, NC 27695 USA. OAK RIDGE NATL LAB, DIV SOLID STATE, OAK RIDGE, TN 37831 USA. RI Narayan, Jagdish/D-1874-2009 NR 25 TC 1 Z9 1 U1 0 U2 0 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0921-5107 J9 MAT SCI ENG B-SOLID JI Mater. Sci. Eng. B-Solid State Mater. Adv. Technol. PD MAR PY 1997 VL 45 IS 1-3 BP 122 EP 125 DI 10.1016/S0921-5107(96)01975-7 PG 4 WC Materials Science, Multidisciplinary; Physics, Condensed Matter SC Materials Science; Physics GA XE981 UT WOS:A1997XE98100019 ER PT J AU Shannon, MA Mao, XL Russo, RE AF Shannon, MA Mao, XL Russo, RE TI Monitoring laser-energy coupling to solid materials: Plasma-shielding and phase change SO MATERIALS SCIENCE AND ENGINEERING B-SOLID STATE MATERIALS FOR ADVANCED TECHNOLOGY LA English DT Article DE laser-energy coupling to solid material; plasma shielding; phase change ID THIN-FILMS; SPECTROSCOPY; DEPOSITION; HEAT AB For many laser-material processes, new methods are needed to monitor laser-energy coupling to solid materials. Different methods will be presented which can detect changes in laser-energy coupling due to plasma shielding, phase change, and surface alterations. The techniques used are inductively coupled plasma-atomic emission spectroscopy (ICP-AES), mechanical stress power (MSP), and photothermal deflection (PTD). This work demonstrates that the onset of plasma shielding can be detected for ns and ps laser interactions with solids, using ICP-AES and MSP, and that the onset of melt at a surface can be detected using PTD. (C) 1997 Elsevier Science S.A. RP Shannon, MA (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,BERKELEY,CA 94720, USA. NR 16 TC 8 Z9 8 U1 2 U2 3 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0921-5107 J9 MAT SCI ENG B-SOLID JI Mater. Sci. Eng. B-Solid State Mater. Adv. Technol. PD MAR PY 1997 VL 45 IS 1-3 BP 172 EP 179 DI 10.1016/S0921-5107(96)01882-X PG 8 WC Materials Science, Multidisciplinary; Physics, Condensed Matter SC Materials Science; Physics GA XE981 UT WOS:A1997XE98100026 ER PT J AU Cotton, JD Field, RD AF Cotton, JD Field, RD TI Microstructural features of cracking in autogenous beryllium weldments SO METALLURGICAL AND MATERIALS TRANSACTIONS A-PHYSICAL METALLURGY AND MATERIALS SCIENCE LA English DT Article AB An investigation was conducted to determine the causes of centerline cracking in autogenous Be weldments. In agreement with earlier studies, features on the fracture surfaces consistent with hot shortness cracking were observed. However, the present study reveals a more complicated solidification path than previously described. Analytical transmission electron microscopy (TEM) studies of the weld centerline revealed low-melting constituents consisting of a MBe(12) grain boundary film and nodules containing elemental Al, elemental Si, and AlFeBe4 phases. Possible solidification pathways to produce this structure are discussed in terms of available binary and ternary phase diagrams. C1 LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545. NR 26 TC 5 Z9 8 U1 0 U2 0 PU MINERALS METALS MATERIALS SOC PI WARRENDALE PA 420 COMMONWEALTH DR, WARRENDALE, PA 15086 SN 1073-5623 J9 METALL MATER TRANS A JI Metall. Mater. Trans. A-Phys. Metall. Mater. Sci. PD MAR PY 1997 VL 28 IS 3 BP 673 EP 680 DI 10.1007/s11661-997-0053-2 PG 8 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA WQ787 UT WOS:A1997WQ78700015 ER PT J AU Misra, A Gibala, R AF Misra, A Gibala, R TI Room-temperature deformation behavior of directionally solidified multiphase Ni-Fe-Al alloys SO METALLURGICAL AND MATERIALS TRANSACTIONS A-PHYSICAL METALLURGY AND MATERIALS SCIENCE LA English DT Article ID MECHANICAL-PROPERTIES; TENSILE DUCTILITY; TRANSITION; CRYSTALS; FRACTURE; SYSTEMS; COMPOSITES; TOUGHNESS; METALS; PHASE AB Directionally solidified (DS) beta + (gamma + gamma') Ni-Fe-Al alloys have been used to investigate the effect of a ductile second phase on the room-temperature mechanical behavior of a brittle [001]-oriented beta (B2) phase. The ductile phase in the composite consisted of a fine distribution of-ordered gamma' precipitates in a gamma (fcc) matrix. Three microstructures were studied: 100 pct lamellar/rod, lamellar + proeutectic beta, and discontinuous gamma. The beta matrix in the latter two microstructures contained fine-scale bcc precipitates formed due to spinodal decomposition. Room-temperature tensile ductilities as high as 12 pct and fracture toughness (K-Q) of 30.4 MPa root m were observed in the 100 pct lamellar/rod microstructure. Observations of slip traces and dislocation substructures indicated that a substantial portion of the ductility was a result of slip transfer from the ductile phase to the brittle matrix. This slip transfer was facilitated by the Kurdjumov-Sachs (KS) orientation relationship between the two phases and the strong interphase interface which showed no decohesion during deformation. In microstructures which show higher values of tensile ductility and fracture toughness, [100] slip was seen in the beta phase, whereas [111] slip was seen in the beta phase in the microstructure which showed limited ductility. The high ductility and toughness are explained:in terms of increased nobile dislocation density afforded by interface constraint. The effect of extrinsic toughening mechanisms on enhancing the ductility or toughness is secondary to that of slip transfer. C1 UNIV MICHIGAN,DEPT MAT SCI & ENGN,ANN ARBOR,MI 48109. RP Misra, A (reprint author), LOS ALAMOS NATL LAB,CTR MAT SCI,LOS ALAMOS,NM 87545, USA. RI Misra, Amit/H-1087-2012 NR 55 TC 33 Z9 33 U1 0 U2 5 PU MINERALS METALS MATERIALS SOC PI WARRENDALE PA 420 COMMONWEALTH DR, WARRENDALE, PA 15086 SN 1073-5623 J9 METALL MATER TRANS A JI Metall. Mater. Trans. A-Phys. Metall. Mater. Sci. PD MAR PY 1997 VL 28 IS 3A BP 795 EP 807 DI 10.1007/s11661-997-1007-4 PG 13 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA WR817 UT WOS:A1997WR81700008 ER PT J AU Symons, DM Thompson, AW AF Symons, DM Thompson, AW TI The effect of hydrogen on the fracture toughness of Alloy X-750 SO METALLURGICAL AND MATERIALS TRANSACTIONS A-PHYSICAL METALLURGY AND MATERIALS SCIENCE LA English DT Article ID STRESS; STEEL AB The effect of hydrogen on the fracture toughness behavior of a nickel-base superalloy, Alloy X-750, in the solutionized and aged condition was investigated. Notched bend specimens were tested to determine if the fracture process was stress or strain controlled. The fracture was observed to initiate at a distance between the location of maximum stress and maximum strain, suggesting that fracture required both a critical stress and strain. The effect of hydrogen was further investigated and modeled using fracture toughness testing and fractographic examination. The fracture toughness of the noncharged specimen was 147 MPa root m. Charging with hydrogen decreased the fracture toughness, K-lc, to 52 MPa root m at a rapid loading rate and further decreased the toughness to 42 MPa root m for a slow loading rate. This is consistent with the rate-limiting step for the embrittlement process being hydrogen diffusion. The fracture morphology for the hydrogen-charged specimens was intergranular ductile dimple, while the fracture morphology of noncharged specimens was a mixture of large transgranular dimples and fine intergranular dimples. The intergranular failure mechanism in Alloy X-750 was a microvoid initiation process at grain boundary carbides followed by void growth and coalescence. One role of hydrogen was to reduce the void initiation strain for the fine intergranular carbides. Hydrogen may have also increased the rate of void growth. The conditions ahead of a crack satisfy the critical stress criterion at a much lower applied stress intensity factor than for the critical fracture strain criterion. A model based on a critical fracture strain criterion is shown to predict the fracture behavior. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV MAT SCI,BERKELEY,CA 94720. RP Symons, DM (reprint author), WESTINGHOUSE ELECT CORP,BETTIS ATOM POWER LAB,W MIFFLIN,PA 15122, USA. NR 27 TC 10 Z9 10 U1 0 U2 0 PU MINERALS METALS MATERIALS SOC PI WARRENDALE PA 420 COMMONWEALTH DR, WARRENDALE, PA 15086 SN 1073-5623 J9 METALL MATER TRANS A JI Metall. Mater. Trans. A-Phys. Metall. Mater. Sci. PD MAR PY 1997 VL 28 IS 3A BP 817 EP 823 DI 10.1007/s11661-997-1009-2 PG 7 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA WR817 UT WOS:A1997WR81700010 ER PT J AU Jones, DA Jankowski, AF Davidson, GA AF Jones, DA Jankowski, AF Davidson, GA TI Room-temperature diffusion in Cu/Ag thin-film couples caused by anodic dissolution SO METALLURGICAL AND MATERIALS TRANSACTIONS A-PHYSICAL METALLURGY AND MATERIALS SCIENCE LA English DT Article ID STRESS-CORROSION; MECHANISM; SYSTEMS; ALLOY; CU AB Thin, 100-nm films of first silver and then copper were deposited consecutively onto inert substrates by magnetron sputter deposition. Constant anodic current densities were applied at room temperature to dissolve the outer copper film to varying depths. The 50Cu/50Ag interface, derived from the auger electron spectroscopic concentration-depth profile, initially moved into the copper toward the outer dissolving surface, indicating enhanced diffusion of copper into silver. After longer times at all anodic current densities, the interface reversed and moved back toward the underlying silver-rich layer, indicating that eventually diffusion of silver into copper predominated. The reversal time was inversely proportional to the anodic current density. These effects are explained by anodic formation of subsurface vacancies which migrate as divacancies to the copper/silver interface where they affect interface movements by the well-known Kirkendall mechanism. Calculated diffusivities up to 10(-12) cm(2)/s at maximum anodic current densities of 900 mu A/cm(2) are dramatically above any that are normally observed at room temperature. C1 LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550. INTEL CORP,RIO RANCHO,NM 87124. RP Jones, DA (reprint author), UNIV NEVADA,DEPT CHEM & MET ENGN,RENO,NV 89557, USA. NR 30 TC 14 Z9 14 U1 0 U2 7 PU MINERALS METALS MATERIALS SOC PI WARRENDALE PA 420 COMMONWEALTH DR, WARRENDALE, PA 15086 SN 1073-5623 J9 METALL MATER TRANS A JI Metall. Mater. Trans. A-Phys. Metall. Mater. Sci. PD MAR PY 1997 VL 28 IS 3A BP 843 EP 850 DI 10.1007/s11661-997-1012-7 PG 8 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA WR817 UT WOS:A1997WR81700013 ER PT J AU Huang, Y Merkle, KL Char, K AF Huang, Y Merkle, KL Char, K TI Transmission electron microscopy microstructure characterization of YBCO/SrRuO3/YBCO Josephson junctions SO MICROSCOPY AND MICROANALYSIS LA English DT Article; Proceedings Paper CT 6th Conference on Frontiers of Electron Microscopy in Materials Science CY JUN 04-07, 1996 CL OAK BROOK, IL SP Argonne Natl Lab, Lawrence Livermore Lab, Oak Ridge Natl Lab, Lawrence Berkeley Natl Lab, Los Alamos Natl Lab, UOP DE high resolution electron microscopy; transmission electron microscopy; SNS junctions; edge junctions; interfacial defects; barrier structure ID METALLIC BARRIER; INTERFACES; CARUO3; LINKS AB The microstructure of YBCO/SrRuO3/YBCO junctions in the edge geometry have been studied by high resolution electron microscopy. Various defects in the YBCO and SrRuO3 films are observed and analyzed. The most striking defects in the c-axis-oriented YBCO film are a-axis particles, which cause bending and interruption of lattice planes as well as high steps and cracks in the subsequent layers. The SrRuO3 layer in the ramp-edge junction region consists of small domains with slightly different orientations. This leads to the formation of steps on its surface and large variation in SrRuO3 thickness. Mechanisms for forming this defective layer are suggested based on the growth mode and the crystal structure of SrRuO3. We find evidence for strain fields at the SrRuO3/YBCO interface. The oxygen deficiency in YBCO caused by this interface strain may to a large part be responsible for the excess resistivity of this junction. In addition to the defective SrRuO3 layer, the occurrence of various defects in the junction area, including Y2O3 and a-axis YBCO particles, seem to be the cause for the wide scatter in the junction electrical characteristics. The formation of steps and large thickness variation in the barrier layer may be the reason for the rather large critical thickness of the SrRuO, superconductor-normal-superconductor (SNS) junction. In addition to the junction interfaces, the microstructure of SrRuO3/LaA1O(3) and SrRuO3/SrTiO3 interfaces have also been studied. C1 CONDUCTUS INC,SUNNYVALE,CA 94086. RP Huang, Y (reprint author), ARGONNE NATL LAB,MAT SCI DIV 212,9700 S CASS AVE,ARGONNE,IL 60439, USA. NR 17 TC 3 Z9 3 U1 2 U2 3 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 SN 1431-9276 J9 MICROSC MICROANAL JI Microsc. microanal. PD MAR-APR PY 1997 VL 3 IS 2 BP 108 EP 120 PG 13 WC Materials Science, Multidisciplinary; Microscopy SC Materials Science; Microscopy GA XK941 UT WOS:A1997XK94100002 ER PT J AU Aloia, JF Vaswani, A Ma, RM Flaster, E AF Aloia, JF Vaswani, A Ma, RM Flaster, E TI Sodium distribution in black and white women SO MINERAL AND ELECTROLYTE METABOLISM LA English DT Article DE sodium; ethnic; neutron activation analysis; aging ID TOTAL-BODY SODIUM; OSTEOPOROSIS; CHLORINE; EXCESS AB Delayed gamma neutron activation analysis (DGNA) was performed on 99 black and 168 healthy white women, aged 20-80 years, to examine sodium distribution in the two ethnic groups, Elements measured included total body levels of sodium (TBNa) and chlorine (TBCl). The black women were heavier, and consequently had a higher body surface area. Sodium excess (Na-es) was calculated from TBNa and TBCl. Total body water was measured by tritiated water dilution, TBNa was higher in black than white women, and this difference persisted when the values were corrected for body surface area, TBNa and Na,, declined significantly with age in white women, whereas extracellular fluid sodium (ECFNa) remained constant, The change with age was not statistically significant in black women for TBNa, Na-es or ECFNa. Our sample of healthy black women had a higher TBNa and Na-es than healthy white women, This difference persisted after adjustment for body surface area, so that values for sodium distribution need to be adjusted for race, The change in TBNa with age in white women appears to be due to their decline of skeletal tissue mass with a consequent decline in nonexchangeable sodium. C1 BROOKHAVEN NATL LAB, UPTON, NY 11973 USA. RP Aloia, JF (reprint author), WINTHROP UNIV HOSP, DEPT MED, 259 1ST ST, MINEOLA, NY 11501 USA. NR 21 TC 6 Z9 6 U1 1 U2 1 PU KARGER PI BASEL PA ALLSCHWILERSTRASSE 10, CH-4009 BASEL, SWITZERLAND SN 0378-0392 J9 MINER ELECTROL METAB JI Miner. Electrolyte Metab. PD MAR-APR PY 1997 VL 23 IS 2 BP 74 EP 78 PG 5 WC Endocrinology & Metabolism SC Endocrinology & Metabolism GA XN050 UT WOS:A1997XN05000002 PM 9252972 ER PT J AU Baskes, MI AF Baskes, MI TI Calculation of the behaviour of Si ad-dimers on Si(001) SO MODELLING AND SIMULATION IN MATERIALS SCIENCE AND ENGINEERING LA English DT Article ID EMBEDDED-ATOM POTENTIALS; SI(100) SURFACE; SILICON; DIFFUSION; BINDING; ADATOM; METALS; ADSORPTION; IMPURITIES; DYNAMICS AB The modified embedded atom method (MEAM) is used to investigate the geometry and energetics of Si ad-dimers and adatoms on the (2 x 1) reconstructed Si(001) surface. Site stability and saddle point energies are predicted for a large number of possible mechanisms. The calculations predict the relative stability of parallel and normal ad-dimers to be 80 meV, in excellent agreement with 60+/-10 meV from experiment, the barrier to rotation of these dimers to be 0.66 eV compared with 0.68+/-0.01 eV, and the activation energy for diffusion parallel to the dimer rows to be 0.74 eV compared with 0.94+/-0.09 eV. These calculations are the first of any kind to predict quantitative agreement with experiment. We also predict substitutional Ni atoms near the Si(001)-(2 x 1) surface are bound to the second and first layer below the dimer layer by 0.65 and 0.47 eV relative to bulk substitutional Ni atoms. The effect of these Ni impurities on the ad-dimer stability is predicted. A parallel ad-dimer is repelled by a substitutional Ni impurity by 30 meV compared with the 20-35 meV observed in experiment for an unknown substrate defect. RP Baskes, MI (reprint author), SANDIA NATL LABS,LIVERMORE,CA 94551, USA. NR 28 TC 23 Z9 24 U1 1 U2 8 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL, ENGLAND BS1 6BE SN 0965-0393 J9 MODEL SIMUL MATER SC JI Model. Simul. Mater. Sci. Eng. PD MAR PY 1997 VL 5 IS 2 BP 149 EP 158 DI 10.1088/0965-0393/5/2/005 PG 10 WC Materials Science, Multidisciplinary; Physics, Applied SC Materials Science; Physics GA WZ635 UT WOS:A1997WZ63500005 ER PT J AU Kunkee, RE AF Kunkee, RE TI A heady concoction of alcoholic and malolactic fermentations SO NATURE BIOTECHNOLOGY LA English DT News Item ID WINE RP Kunkee, RE (reprint author), LAWRENCE LIVERMORE NATL LAB,DEPT VITICULTURE & ENOL,DAVIS,CA 95616, USA. NR 4 TC 6 Z9 6 U1 1 U2 2 PU NATURE PUBLISHING CO PI NEW YORK PA 345 PARK AVE SOUTH, NEW YORK, NY 10010-1707 SN 1087-0156 J9 NAT BIOTECHNOL JI Nat. Biotechnol. PD MAR PY 1997 VL 15 IS 3 BP 224 EP 225 DI 10.1038/nbt0397-224 PG 2 WC Biotechnology & Applied Microbiology SC Biotechnology & Applied Microbiology GA WM050 UT WOS:A1997WM05000021 PM 9062919 ER PT J AU Flint, J Thomas, K Micklem, G Raynham, H Clark, K Doggett, NA King, A Higgs, DR AF Flint, J Thomas, K Micklem, G Raynham, H Clark, K Doggett, NA King, A Higgs, DR TI The relationship between chromosome structure and function at a human telomeric region SO NATURE GENETICS LA English DT Article ID GLOBIN GENE-CLUSTER; HUMAN ZETA-GLOBIN; ALPHA-THALASSEMIA; LENGTH POLYMORPHISM; REGULATORY ELEMENT; HUMAN GENOME; DNA; SEQUENCE; EXPRESSION; CHROMATIN AB We have sequenced a contiguous 284,495-bp segment of DNA extending from the terminal (TTAGGC)(n) repeats of the short arm of chromosome 16, providing a full description of the transition from telomeric through subtelomeric DNA to sequences that are unique to the chromosome. To complement and extend analysis of the primary sequence, we have characterized mRNA transcripts, patterns of DNA methylation and DNase I sensitivity. Together with previous data these studies describe in detail the structural and functional organization of a human telomeric region. C1 JOHN RADCLIFFE HOSP,INST MOL MED,MRC,MOL HAEMATOL UNIT,OXFORD OX3 9DU,ENGLAND. SANGER CTR,CAMBRIDGE CB10 1RQ,ENGLAND. LOS ALAMOS NATL LAB,DIV LIFE SCI,LOS ALAMOS,NM 87545. FU Wellcome Trust NR 56 TC 124 Z9 128 U1 0 U2 2 PU NATURE PUBLISHING CO PI NEW YORK PA 345 PARK AVE SOUTH, NEW YORK, NY 10010-1707 SN 1061-4036 J9 NAT GENET JI Nature Genet. PD MAR PY 1997 VL 15 IS 3 BP 252 EP 257 DI 10.1038/ng0397-252 PG 6 WC Genetics & Heredity SC Genetics & Heredity GA WK386 UT WOS:A1997WK38600013 PM 9054936 ER PT J AU Herrmann, HW Zweben, SJ Darrow, DS Timberlake, JR Chong, GP Haasz, AA Pitcher, CS MacaulayNewcombe, RG AF Herrmann, HW Zweben, SJ Darrow, DS Timberlake, JR Chong, GP Haasz, AA Pitcher, CS MacaulayNewcombe, RG TI Deuterium-tritium results of TFTR's alpha collector SO NUCLEAR FUSION LA English DT Article ID FUSION TEST REACTOR; PRODUCTS; IONS; IONIZATION; DETECTORS; DIFFUSION; TRITONS; LOSSES; PROBE; JET AB An escaping alpha collector probe has been developed for the deuterium-tritium (DT) phase of the Tokamak. Fusion Test Reactor (TFTR) to complement the results of the lost alpha scintillator detectors, which have been operating on TFTR since 1988. Measurements of the energy distribution of escaping alphas have been made by measuring the range of alphas implanted into nickel foils located within the alpha collector. Exposed samples have been analysed for four DT plasma discharges at plasma currents of 1.0 and 1.8 MA. The results at 1.0 MA are in good agreement with predictions for first orbit alpha loss at 3.5 MeV. The 1.8 MA results, however, indicate a large anomalous loss of partially thermalized alphas at an energy similar to 30% below the birth energy and at a total fluence nearly an order of magnitude above the expected first orbit loss. This anomalous loss is not observed with the lost alpha scintillator detectors in DT plasmas but does resemble the anomalous 'delayed' loss seen in DD plasmas. Several potential. explanations for this loss process are examined. None of the candidate explanations proposed thus far are fully consistent with the anomalous loss observations. C1 UNIV TORONTO,INST AEROSP STUDIES,DOWNSVIEW,ON,CANADA. MAX PLANCK INST PLASMA PHYS,GARCHING,GERMANY. MCMASTER UNIV,DEPT ENGN PHYS,HAMILTON,ON,CANADA. RP Herrmann, HW (reprint author), PRINCETON UNIV,PRINCETON PLASMA PHYS LAB,POB 451,PRINCETON,NJ 08543, USA. NR 39 TC 15 Z9 15 U1 0 U2 4 PU INT ATOMIC ENERGY AGENCY PI VIENNA PA WAGRAMERSTRASSE 5, PO BOX 100, A-1400 VIENNA, AUSTRIA SN 0029-5515 J9 NUCL FUSION JI Nucl. Fusion PD MAR PY 1997 VL 37 IS 3 BP 293 EP 320 DI 10.1088/0029-5515/37/3/I02 PG 28 WC Physics, Fluids & Plasmas SC Physics GA XP371 UT WOS:A1997XP37100002 ER PT J AU Elias, JE AF Elias, JE TI Photodetectors for the CMS hadron calorimeters SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 1st International Conference on New Developments in Photodetection CY JUN 24-28, 1996 CL BEAUNE, FRANCE SP Direct Sci Matiere, Inst Phys Nucl Phys Part, Minist Rech, European Commiss AB Hadronic energy measurements in the central and end cap regions of the Compact Muon Solenoid (CMS) detector will be made using sampling calorimeter techniques with plastic scintillator tiles as the sensitive layers. Plastic fibers doped with wavelength shifting fluors embedded in each tile are used to extract the scintillation light. Clear plastic wave guide fibers carry the shifted light to photodetectors located on the outer surface of the calorimeter structure. Environmental constraints and physics performance requirements for these photodetectors are presented. Candidate photodetector technologies are discussed, and the hybrid photomultiplier tube technology is identified as most promising. RP FERMILAB NATL ACCELERATOR LAB, MAIL STOP 318, POB 500, BATAVIA, IL 60510 USA. NR 4 TC 1 Z9 1 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 EI 1872-9576 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD MAR 1 PY 1997 VL 387 IS 1-2 BP 104 EP 106 DI 10.1016/S0168-9002(96)00971-0 PG 3 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA WV278 UT WOS:A1997WV27800023 ER PT J AU Vavra, J AF Vavra, J TI Photon detectors with gaseous amplification SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 1st International Conference on New Developments in Photodetection CY JUN 24-28, 1996 CL BEAUNE, FRANCE SP Direct Sci Matiere, Inst Phys Nucl Phys Part, Minist Rech, European Commiss ID IMAGING CHERENKOV DETECTOR; PARALLEL-PLATE CHAMBERS; DELPHI BARREL RICH; WIRE CHAMBERS; OMEGA RICH; LOW-NOISE; AVALANCHE; READOUT; PERFORMANCE; PROTOTYPE AB This paper reviews the progress of photon detectors with gaseous amplification. RP Vavra, J (reprint author), STANFORD UNIV,STANFORD LINEAR ACCELERATOR CTR,SLAC,STANFORD,CA 94309, USA. NR 84 TC 8 Z9 8 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD MAR 1 PY 1997 VL 387 IS 1-2 BP 137 EP 145 DI 10.1016/S0168-9002(96)00977-1 PG 9 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA WV278 UT WOS:A1997WV27800030 ER PT J AU Vavra, J AF Vavra, J TI Wire ageing with the TEA photocathode SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 1st International Conference on New Developments in Photodetection CY JUN 24-28, 1996 CL BEAUNE, FRANCE SP Direct Sci Matiere, Inst Phys Nucl Phys Part, Minist Rech, European Commiss ID PAD-PHOTON DETECTOR AB Recently several RICH prototypes successfully tested a gaseous TEA photocathode. However, its wire ageing behavior is unknown. In principle, TEA is a more strongly bonded molecule than TMAE, and, as a result, one would expect better wire ageing behavior. This paper explores this question. RP Vavra, J (reprint author), STANFORD UNIV,STANFORD LINEAR ACCELERATOR CTR,STANFORD,CA 94309, USA. NR 10 TC 8 Z9 8 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD MAR 1 PY 1997 VL 387 IS 1-2 BP 183 EP 185 DI 10.1016/S0168-9002(96)00986-2 PG 3 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA WV278 UT WOS:A1997WV27800038 ER PT J AU Roberts, ML Bench, GS Brown, TA Caffee, MW Finkel, RC Freeman, SPHT Hainsworth, LJ Kashgarian, M McAninch, JE Proctor, ID Southon, JR Vogel, JS AF Roberts, ML Bench, GS Brown, TA Caffee, MW Finkel, RC Freeman, SPHT Hainsworth, LJ Kashgarian, M McAninch, JE Proctor, ID Southon, JR Vogel, JS TI The LLNL AMS facility SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS LA English DT Article; Proceedings Paper CT 7th Conference on Accelerator Mass Spectrometry CY MAY 20-24, 1996 CL TUCSON, AZ SP AMS AB The AMS facility at Lawrence Livermore National Laboratory (LLNL) routinely measures the isotopes H-3, Be-7, Be-10, C-14, Al-26, Cl-36, Ca-41, and I-129. During the past two years, over 30000 research samples have been measured. Of these samples, approximately 30% were for C-14 bioscience tracer studies, 45% were C-14 samples for archaeology and the geosciences, and the other isotopes constitute the remaining 25%. During the past two years at LLNL, a significant amount of work has gone into the development of the Projectile X-ray AMS (PXAMS) technique. PXAMS uses induced characteristic X-rays to discriminate against competing atomic isobars. PXAMS has been most fully developed for Ni-63 but shows promise for the measurement of several other long lived isotopes. During the past year LLNL, has also conducted an I-129 interlaboratory comparison exercise. Recent hardware changes at the LLNL AMS facility include the installation and testing of a new thermal emission ion source, a new multi-anode gas ionization detector for general AMS use, re-alignment of the vacuum tank of the first of the two magnets that make up the high energy spectrometer, and a new cryo-vacuum system for the AMS ion source. In addition, we have begun design studies and carried out tests for a new high-resolution injector and a new beamline for heavy element AMS. RP Roberts, ML (reprint author), LAWRENCE LIVERMORE NATL LAB,CTR ACCELERATOR MASS SPECTROMETRY,LIVERMORE,CA 94551, USA. RI Kashgarian, Michaele/E-1665-2011; Caffee, Marc/K-7025-2015; Freeman, Stewart/C-3290-2012 OI Kashgarian, Michaele/0000-0001-7824-8418; Caffee, Marc/0000-0002-6846-8967; Freeman, Stewart/0000-0001-6148-3171 NR 9 TC 31 Z9 31 U1 1 U2 5 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-583X J9 NUCL INSTRUM METH B JI Nucl. Instrum. Methods Phys. Res. Sect. B-Beam Interact. Mater. Atoms PD MAR PY 1997 VL 123 IS 1-4 BP 57 EP 61 DI 10.1016/S0168-583X(96)00426-0 PG 5 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Atomic, Molecular & Chemical; Physics, Nuclear SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA WT653 UT WOS:A1997WT65300013 ER PT J AU Collon, P Antaya, T Davids, B Fauerbach, M Harkewicz, R Hellstrom, M Kutschera, W Morrissey, D Pardo, R Paul, M Sherrill, B Steiner, M AF Collon, P Antaya, T Davids, B Fauerbach, M Harkewicz, R Hellstrom, M Kutschera, W Morrissey, D Pardo, R Paul, M Sherrill, B Steiner, M TI Measurement of Kr-81 in the atmosphere SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS LA English DT Article; Proceedings Paper CT 7th Conference on Accelerator Mass Spectrometry CY MAY 20-24, 1996 CL TUCSON, AZ SP AMS ID ION-SOURCE AB We present the first AMS measurement of the Kr-81 concentration in atmospheric krypton. The measurement was performed by combining positive-ion production in an electron cyclotron resonance source with acceleration to high energy in a cyclotron and subsequent full stripping for Br-81-Kr-81 separation. The result, Kr-81/Kr = (5.3 +/- 1.2) x 10(-13), agrees well with two previous low-level decay counting measurements. C1 MICHIGAN STATE UNIV,CYCLOTRON LAB,E LANSING,MI 48824. ARGONNE NATL LAB,DIV PHYS,ARGONNE,IL 60439. HEBREW UNIV JERUSALEM,RACAH INST PHYS,IL-91904 JERUSALEM,ISRAEL. RP Collon, P (reprint author), UNIV VIENNA,INST RADIUMFORSCH & KERNPHYS,BOLTZMANNGASSE 3,A-1090 VIENNA,AUSTRIA. RI Sherrill, Bradley/B-4098-2009; Sherrill, Bradley/B-3378-2011 NR 10 TC 40 Z9 40 U1 0 U2 4 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-583X J9 NUCL INSTRUM METH B JI Nucl. Instrum. Methods Phys. Res. Sect. B-Beam Interact. Mater. Atoms PD MAR PY 1997 VL 123 IS 1-4 BP 122 EP 127 DI 10.1016/S0168-583X(96)00674-X PG 6 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Atomic, Molecular & Chemical; Physics, Nuclear SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA WT653 UT WOS:A1997WT65300025 ER PT J AU McAninch, JE Hainsworth, LJ Marchetti, AA Leivers, MR Jones, PR Dunlop, AE Mauthe, R Vogel, JS Proctor, ID Straume, T AF McAninch, JE Hainsworth, LJ Marchetti, AA Leivers, MR Jones, PR Dunlop, AE Mauthe, R Vogel, JS Proctor, ID Straume, T TI Measurement of Ni-63 and Ni-59 by accelerator mass spectrometry using characteristic projectile X-rays SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS LA English DT Article; Proceedings Paper CT 7th Conference on Accelerator Mass Spectrometry CY MAY 20-24, 1996 CL TUCSON, AZ SP AMS ID CARBONYL GENERATION; HIROSHIMA; NICKEL; AMS AB The long-lived isotopes of nickel (Ni-59, Ni-63) have current and potential use in a number of applications including cosmic radiation studies, biomedical tracing, characterization of low-level radioactive wastes, and neutron dosimetry. Methods are being developed at LLNL for the routine detection of these isotopes by AMS. One intended application is in Hiroshima dosimetry. The reaction Cu-63(n,p)Ni-63 has been identified as one of a small number of reactions which might be used for the direct determination of the fast neutron fluence emitted by the Hiroshima bomb. AMS measurement of Ni-63 (t(1/2) = 100 y) requires the chemical removal of Cu-63, which is a Stable isobar of Ni-63. Following the electrochemical separation of Ni from gram-sized copper samples, the Cu concentration is further lowered to < 2 x 10(-8) (Cu/Ni) using the reaction of Ni with carbon monoxide to form the gas Ni(CO)(4). The NI(CO)(4) is thermally decomposed directly in sample holders for measurement by AMS. After analysis in the AMS spectrometer, the ions are identified using characteristic projectile X-rays, allowing further rejection of remaining Cu-63. In a demonstration experiment, Ni-63 was measured in Cu wires (2-20 g) which had been exposed to neutrons from a Cf-252 source. We successfully measured Ni-63 at levels necessary for the measurement of Cu samples exposed near the Hiroshima hypocenter. For the demonstration samples, the Cu content was chemically reduced by a factor of 10(12) with quantitative retention of Ni-63. Detection sensitivity (3 sigma) was similar to 20 fg Ni-63 in 1 mg Ni carrier (Ni-63/Ni approximate to 2 x 10(-11)). Significant improvements in sensitivity are expected with planned incremental changes in the methods. Preliminary results indicate that a similar sensitivity is achievable for Ni-59 (t(1/2) = 10(5) y), Initial work has been undertaken on the application of this isotope as a biomedical tracer in living systems. C1 UNIV PACIFIC,STOCKTON,CA 95211. RP McAninch, JE (reprint author), LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94551, USA. NR 25 TC 32 Z9 33 U1 1 U2 4 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-583X J9 NUCL INSTRUM METH B JI Nucl. Instrum. Methods Phys. Res. Sect. B-Beam Interact. Mater. Atoms PD MAR PY 1997 VL 123 IS 1-4 BP 137 EP 143 DI 10.1016/S0168-583X(96)00411-9 PG 7 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Atomic, Molecular & Chemical; Physics, Nuclear SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA WT653 UT WOS:A1997WT65300028 ER PT J AU Brown, TA Southon, JR AF Brown, TA Southon, JR TI Corrections for contamination background in AMS C-14 measurements SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS LA English DT Article; Proceedings Paper CT 7th Conference on Accelerator Mass Spectrometry CY MAY 20-24, 1996 CL TUCSON, AZ SP AMS ID RADIOCARBON MEASUREMENTS AB Measurements of C-14/C-13 ratios were made on samples of Oxalic Acid and C-14 ''dead'' materials spanning the mass range from 10 mu g to similar to 1 mg. These measurements have allowed the determination of both the amount, and the C-14 content, of the contaminant carbon introduced during sample processing in our laboratory. These data were used to correct measured C-14/C-13 ratios obtained from ANU Sucrose and ''similar to one-half-life old'' test samples for the influence of the contaminant, The test samples spanned the 10 mu g to similar to 1 mg mass range and the corrections were made using three different formulae, The results obtained from these calculations allow the accuracy of these background correction formulae to be evaluated. C1 LAWRENCE LIVERMORE NATL LAB,CTR ACCELERATOR MASS SPECTROMETRY,LIVERMORE,CA 94551. NR 9 TC 70 Z9 70 U1 1 U2 9 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-583X J9 NUCL INSTRUM METH B JI Nucl. Instrum. Methods Phys. Res. Sect. B-Beam Interact. Mater. Atoms PD MAR PY 1997 VL 123 IS 1-4 BP 208 EP 213 DI 10.1016/S0168-583X(96)00676-3 PG 6 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Atomic, Molecular & Chemical; Physics, Nuclear SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA WT653 UT WOS:A1997WT65300043 ER PT J AU Kirner, DL Burky, R Taylor, RE Southon, JR AF Kirner, DL Burky, R Taylor, RE Southon, JR TI Radiocarbon dating organic residues at the microgram level SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS LA English DT Article; Proceedings Paper CT 7th Conference on Accelerator Mass Spectrometry CY MAY 20-24, 1996 CL TUCSON, AZ SP AMS ID ACCELERATOR MASS-SPECTROMETRY; ION-SOURCE AB The relationship between submilligram sample size and C-14 activity for sample blanks (wood from Pliocene sediments) and a contemporary standard (oxalic acid [I]) for catalytically-reduced graphitic carbon have been examined down to 20 micrograms, The mean age of our 1 milligram wood sample blanks is now about 51.6 ka (0.162 pMC) while the mean for 20 microgram sample blanks is about 42.9 ka, So far, our lowest value for a 1 milligram wood sample blank is about 60.5 ka (0.056 pMC). We have determined a mean C-14 age of about 9.4 ka from a suite of seven organic extracts from hair, bone and matting from a naturally mummified human skeleton from Spirit Cave, Nevada, These data indicate that the Spirit Cave human is the third oldest directly-dated human skeleton currently reported from North America. C1 LAWRENCE LIVERMORE NATL LAB,LAB ACCELERATOR MASS SPECT,LIVERMORE,CA 94550. RP Kirner, DL (reprint author), UNIV CALIF RIVERSIDE,INST GEOPHYS & PLANETARY PHYS,DEPT ANTHROPOL,RADIOCARBON LAB,RIVERSIDE,CA 92521, USA. NR 16 TC 14 Z9 14 U1 1 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-583X J9 NUCL INSTRUM METH B JI Nucl. Instrum. Methods Phys. Res. Sect. B-Beam Interact. Mater. Atoms PD MAR PY 1997 VL 123 IS 1-4 BP 214 EP 217 DI 10.1016/S0168-583X(96)00752-5 PG 4 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Atomic, Molecular & Chemical; Physics, Nuclear SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA WT653 UT WOS:A1997WT65300044 ER PT J AU Marchetti, AA Hainsworth, LJ McAninch, JE Leivers, MR Jones, PR Proctor, ID Straume, T AF Marchetti, AA Hainsworth, LJ McAninch, JE Leivers, MR Jones, PR Proctor, ID Straume, T TI Ultra-separation of nickel from copper metal for the measurement of Ni-63 by AMS SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS LA English DT Article; Proceedings Paper CT 7th Conference on Accelerator Mass Spectrometry CY MAY 20-24, 1996 CL TUCSON, AZ SP AMS ID HIROSHIMA AB Measurements of Ni-63 (t(1/2) = 100 yr) produced by the reaction Cu-63(n,p)Ni-63 could be used in the assessment of fast-neutron fluence from the Hiroshima atomic bomb, Such measurements would add new information to help resolve the current discrepancy between measured thermal neutron activation values and those calculated with the DS86 dosimetry system, It has been estimated that the Ni-63 production at 5 m from the hypocenter was (1.4 +/- 0.1) x 10(7) atoms/g Cu. Because of its sensitivity, accelerator mass spectrometry (AMS) is ideal for measurements at this low level, However, Ni-63 has to be separated from large amounts of stable atomic isobar Cu-63 (69% of pure Cu), In this study, a procedure is presented for the electrochemical separation of ultra-low amounts of Ni from Cu. The method was developed using samples of electrical Cu wire that were irradiated with fission neutrons from a Cf-252 source, The wire samples were electrochemically dissolved in a solution containing 1 mg of Ni carrier, The Cu was selectively deposited on a cathode at controlled potential. Measurements of total Ni after electroseparation indicate similar to 100% carrier recovery, To prevent Cu contamination, AMS targets were prepared by nickel carbonyl generation, The AMS results show a successful quantitative separation of similar to 10(7) atoms of Ni-63 from 2-20 g samples of Cu. C1 LAWRENCE LIVERMORE NATL LAB,CTR ACCELERATOR MASS SPECTROMETRY,LIVERMORE,CA 94551. UNIV PACIFIC,STOCKTON,CA 95221. RP Marchetti, AA (reprint author), LAWRENCE LIVERMORE NATL LAB,HLTH & ECOL ASSESSMENT DIV,POB 808,LIVERMORE,CA 94551, USA. NR 12 TC 18 Z9 18 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-583X J9 NUCL INSTRUM METH B JI Nucl. Instrum. Methods Phys. Res. Sect. B-Beam Interact. Mater. Atoms PD MAR PY 1997 VL 123 IS 1-4 BP 230 EP 234 DI 10.1016/S0168-583X(96)00611-8 PG 5 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Atomic, Molecular & Chemical; Physics, Nuclear SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA WT653 UT WOS:A1997WT65300048 ER PT J AU Vogel, JS McAninch, J Freeman, SPHT AF Vogel, JS McAninch, J Freeman, SPHT TI Elements in biological AMS SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS LA English DT Article; Proceedings Paper CT 7th Conference on Accelerator Mass Spectrometry CY MAY 20-24, 1996 CL TUCSON, AZ SP AMS ID ACCELERATOR MASS-SPECTROMETRY; DNA AB AMS provides high detection sensitivity for isotopes whose half-lives are between 10 years and 100 million years. C-14 is the most developed of such isotopes and is used in tracing natural and anthropogenic organic compounds in the Earth's biosphere. Thirty-three elements in the main Periodic Table and 17 lanthanides or actinides have long lived isotopes, providing potential tracers for research in elemental biochemistry. The overlap of biologically interesting heavy elements and possible AMS tracers is discussed. RP Vogel, JS (reprint author), LAWRENCE LIVERMORE NATL LAB,CTR ACCELERATOR MASS SPECTROMETRY,LIVERMORE,CA 94551, USA. RI Freeman, Stewart/C-3290-2012 OI Freeman, Stewart/0000-0001-6148-3171 NR 14 TC 9 Z9 9 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-583X J9 NUCL INSTRUM METH B JI Nucl. Instrum. Methods Phys. Res. Sect. B-Beam Interact. Mater. Atoms PD MAR PY 1997 VL 123 IS 1-4 BP 241 EP 244 DI 10.1016/S0168-583X(96)00679-9 PG 4 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Atomic, Molecular & Chemical; Physics, Nuclear SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA WT653 UT WOS:A1997WT65300050 ER PT J AU Freeman, SPHT King, JC Vieira, NE Woodhouse, LR Yergey, AL AF Freeman, SPHT King, JC Vieira, NE Woodhouse, LR Yergey, AL TI Human calcium metabolism including bone resorption measured with Ca-41 tracer SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS LA English DT Article; Proceedings Paper CT 7th Conference on Accelerator Mass Spectrometry CY MAY 20-24, 1996 CL TUCSON, AZ SP AMS AB Accelerator mass spectrometry is so sensitive to small quantities of Ca-41 that it might be used as a tracer in the study of human calcium kinetics to generate unique kinds of data. In contrast with the use of other Ca isotopic tracers, Ca-41 tracer can be so administered that the tracer movements between the various body pools achieve a quasi steady state, Resorbing bone may thus be directly measured, We have tested such a protocol against a conventional stable isotope experiment with good agreement. C1 LAWRENCE LIVERMORE NATL LAB,CTR ACCELERATOR MASS SPECTROMETRY,LIVERMORE,CA 94551. UNIV CALIF BERKELEY,DEPT NUTR SCI,BERKELEY,CA 94720. NICHHD,BETHESDA,MD 20892. RI Freeman, Stewart/C-3290-2012 OI Freeman, Stewart/0000-0001-6148-3171 NR 5 TC 45 Z9 46 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-583X J9 NUCL INSTRUM METH B JI Nucl. Instrum. Methods Phys. Res. Sect. B-Beam Interact. Mater. Atoms PD MAR PY 1997 VL 123 IS 1-4 BP 266 EP 270 DI 10.1016/S0168-583X(96)00701-X PG 5 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Atomic, Molecular & Chemical; Physics, Nuclear SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA WT653 UT WOS:A1997WT65300055 ER PT J AU Cecil, LD Vogt, S AF Cecil, LD Vogt, S TI Identification of bomb-produced chlorine-36 in mid-latitude glacial ice of North America SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS LA English DT Article; Proceedings Paper CT 7th Conference on Accelerator Mass Spectrometry CY MAY 20-24, 1996 CL TUCSON, AZ SP AMS ID CL-36 AB In 1991, the U.S. Geological Survey collected a 160-meter (m) ice core from the Upper Fremont Glacier (43 degrees 07'N, 109 degrees 36'W) in the Wind River Mountain Range of Wyoming in the western United States [1]. In 1994-95, ice from this core was processed at the National Ice Core Laboratory in Denver, Colorado, and analyzed for chlorine-36 (Cl-36) by accelerator mass spectrometry at PRIME Laboratory, Purdue University. A tritium bomb peak identified in the work by [1] was used as a marker to estimate the depth of bomb-produced Cl-36. Tritium concentrations ranged from 0 tritium units (TU) for older ice to more than 300 TU at 29 m below the surface of the glacier, a depth that includes ice that was deposited as snow during nuclear-weapons tests through the early 1960's. Maximum Cl-36 production during nuclear-weapons tests was in the late 1950's; therefore, the analyses were performed on ice from a depth of 29.8 to 32 m. Calculated flux for Cl-36 in ice deposited in the late 1950's ranged from 1.2 +/- 0.1 x 10(-1) atoms/cm(2) s for ice from 29.8 to 30.4 m, to 2.9 +/- 0.1 x 10(-1) atoms/cm(2) s for ice from 31.5 to 32.0 m. Ice samples from a depth of 104.7 to 106.3 m were selected to represent pre-weapons tests Cl-36 flux. Calculated flux for Cl-36. in this deeper ice was 4.6 +/- 0.8 x 10(-3) atoms/cm(2) s for ice from 104.7 to 105.5 m and 2.0 +/- 0.2 x 10(-2) atoms/cm(2) s for ice from 105.5 to 106.3 m. These flux calculations from the Upper Fremont Glacier analyses are the first for bomb-produced Cl-36 in ice from a mid-latitude glacier in North America. It may now be possible to fully quantify the flux of Cl-36 from nuclear-weapons tests archived in mid-latitude glacial ice and to gain a better understanding of the distribution of Cl-36 and other cosmogenic nuclides. C1 PURDUE UNIV,DEPT CHEM,W LAFAYETTE,IN 47907. RP Cecil, LD (reprint author), US GEOL SURVEY,IDAHO NATL ENGN LAB,PROJECT OFF,IDAHO FALLS,ID 83415, USA. NR 11 TC 15 Z9 15 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-583X J9 NUCL INSTRUM METH B JI Nucl. Instrum. Methods Phys. Res. Sect. B-Beam Interact. Mater. Atoms PD MAR PY 1997 VL 123 IS 1-4 BP 287 EP 289 PG 3 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Atomic, Molecular & Chemical; Physics, Nuclear SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA WT653 UT WOS:A1997WT65300060 ER PT J AU Sisterson, JM Kim, K Beverding, A Englert, PAJ Caffee, M Jull, AJT Donahue, DJ McHargue, L Castaneda, C Vincent, J Reedy, RC AF Sisterson, JM Kim, K Beverding, A Englert, PAJ Caffee, M Jull, AJT Donahue, DJ McHargue, L Castaneda, C Vincent, J Reedy, RC TI Measurement of proton production cross sections of Be-10 and Al-26 from elements found in lunar rocks SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS LA English DT Article; Proceedings Paper CT 7th Conference on Accelerator Mass Spectrometry CY MAY 20-24, 1996 CL TUCSON, AZ SP AMS ID MG; AL AB Proton production cross sections for Be-10, Al-26, Be-7 and Na-2Z produced by protons in silicon dioxide (for oxygen) and silicon targets over a wide proton energy range, 25-500 MeV, have been measured using accelerator mass spectrometry or nondestructive gamma-ray spectroscopy. These cross sections are important for interpreting measurements of the concentration of these nuclides produced in extraterrestrial materials by cosmic rays. C1 SAN JOSE STATE UNIV,DEPT CHEM,SAN JOSE,CA 92192. LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550. UNIV ARIZONA,NSF,ARIZONA AMS FACIL,TUCSON,AZ 85721. UNIV CALIF DAVIS,CROCKER NUCL LAB,DAVIS,CA 95616. TRIUMF,VANCOUVER,BC V6T 2A3,CANADA. LOS ALAMOS NATL LAB,GRP NIS2,LOS ALAMOS,NM 87545. RP Sisterson, JM (reprint author), HARVARD UNIV,CYCLOTRON LAB,CAMBRIDGE,MA 02138, USA. RI Caffee, Marc/K-7025-2015; OI Caffee, Marc/0000-0002-6846-8967; Kim, Kyeong J/0000-0001-6220-8411; Reedy, Robert/0000-0002-2189-1303 NR 26 TC 40 Z9 40 U1 0 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-583X J9 NUCL INSTRUM METH B JI Nucl. Instrum. Methods Phys. Res. Sect. B-Beam Interact. Mater. Atoms PD MAR PY 1997 VL 123 IS 1-4 BP 324 EP 329 DI 10.1016/S0168-583X(96)00409-0 PG 6 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Atomic, Molecular & Chemical; Physics, Nuclear SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA WT653 UT WOS:A1997WT65300066 ER PT J AU Imamura, M Nishiizumi, K Caffee, MW Shibata, S AF Imamura, M Nishiizumi, K Caffee, MW Shibata, S TI Measurements of proton-induced production Gross sections for Cl-36 from Ca and K SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS LA English DT Article; Proceedings Paper CT 7th Conference on Accelerator Mass Spectrometry CY MAY 20-24, 1996 CL TUCSON, AZ SP AMS AB Production cross sections for Cl-36 (half-life = 3.01 x 10(5) y) have been measured for the nat.K(p,x), K-39(p,x), nat.Ca(p,x) and Ca-40(p,x) reactions up to 40 MeV. The results of nat,Ca(p,x) reaction are generally consistent with measurements performed at somewhat higher energies, With the completion of these measurements it is now possible to proceed with model calculations of the solar cosmic ray (SCR) flux over the last 400 ky based on measurements of lunar surface materials. C1 UNIV CALIF BERKELEY,SPACE SCI LAB,BERKELEY,CA 94720. LAWRENCE LIVERMORE NATL LAB,GEOSCI & ENVIRONM TECHNOL DIV,LIVERMORE,CA 94551. RP Imamura, M (reprint author), UNIV TOKYO,INST NUCL STUDY,TANASHI,TOKYO 188,JAPAN. RI Caffee, Marc/K-7025-2015 OI Caffee, Marc/0000-0002-6846-8967 NR 8 TC 4 Z9 4 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-583X J9 NUCL INSTRUM METH B JI Nucl. Instrum. Methods Phys. Res. Sect. B-Beam Interact. Mater. Atoms PD MAR PY 1997 VL 123 IS 1-4 BP 330 EP 333 DI 10.1016/S0168-583X(96)00712-4 PG 4 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Atomic, Molecular & Chemical; Physics, Nuclear SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA WT653 UT WOS:A1997WT65300067 ER PT J AU Marchetti, AA Gu, F Robl, R Straume, T AF Marchetti, AA Gu, F Robl, R Straume, T TI Determination of total iodine and sample preparation for AMS measurement of I-129 in environmental matrices SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS LA English DT Article; Proceedings Paper CT 7th Conference on Accelerator Mass Spectrometry CY MAY 20-24, 1996 CL TUCSON, AZ SP AMS AB A method is described for the measurement of total iodine and sample preparation for accelerator mass spectrometry (AMS) measurement of I-129. Samples were combusted in a stream of oxygen and the iodine liberated was collected in a trapping solution. Aliquots of the trapping solution were used to measure total iodine by gas chromatography and I-129 by AMS. The method was tested using standard reference materials 2709 San Joaquin Soil, 2711 Montana Soil and 2704 Buffalo River Sediment from the National institute of Standards and Technology, IAEA-375 soil from the International Atomic Energy Agency, a bovine thyroid sample from Gomel, KI and KIO3. The recoveries with respect to the reference values were between 89 and 100%. No tracers were used and no efficiency corrections were applied to these results. C1 SHANGHAI INST RADIAT MED,SHANGHAI 200032,PEOPLES R CHINA. GSF MUNICH,INST STRAHLENSCHUTZ,D-85758 MUNICH,GERMANY. RP Marchetti, AA (reprint author), LAWRENCE LIVERMORE NATL LAB,HLTH & ECOL ASSESSMENT DIV,POB 808,LIVERMORE,CA 94551, USA. NR 11 TC 23 Z9 23 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-583X J9 NUCL INSTRUM METH B JI Nucl. Instrum. Methods Phys. Res. Sect. B-Beam Interact. Mater. Atoms PD MAR PY 1997 VL 123 IS 1-4 BP 352 EP 355 DI 10.1016/S0168-583X(96)00633-7 PG 4 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Atomic, Molecular & Chemical; Physics, Nuclear SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA WT653 UT WOS:A1997WT65300071 ER PT J AU Roberts, ML Caffee, MW Proctor, ID AF Roberts, ML Caffee, MW Proctor, ID TI I-129 interlaboratory comparison SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS LA English DT Article; Proceedings Paper CT 7th Conference on Accelerator Mass Spectrometry CY MAY 20-24, 1996 CL TUCSON, AZ SP AMS AB An interlaboratory comparison exercise for I-129 has been organized and conducted. A total of seven laboratories participated in the exercise to either a full or limited extent. In the comparison, a suite of 11 samples was used. This suite of standards contained both synthetic ''standard type'' materials (i.e., AgI) and environmental materials. The isotopic I-129/I-127 ratio of the samples varied from 10(-8) to 10(-14). Preliminary results of the comparison are presented. RP Roberts, ML (reprint author), LAWRENCE LIVERMORE NATL LAB,CTR ACCELERATOR MASS SPECTROMETRY,LIVERMORE,CA 94550, USA. RI Caffee, Marc/K-7025-2015 OI Caffee, Marc/0000-0002-6846-8967 NR 0 TC 37 Z9 37 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-583X J9 NUCL INSTRUM METH B JI Nucl. Instrum. Methods Phys. Res. Sect. B-Beam Interact. Mater. Atoms PD MAR PY 1997 VL 123 IS 1-4 BP 367 EP 370 DI 10.1016/S0168-583X(96)00407-7 PG 4 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Atomic, Molecular & Chemical; Physics, Nuclear SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA WT653 UT WOS:A1997WT65300074 ER PT J AU Paul, M Berkovits, D Cecil, LD Feldstein, H Hershkowitz, A Kashiv, Y Vogt, S AF Paul, M Berkovits, D Cecil, LD Feldstein, H Hershkowitz, A Kashiv, Y Vogt, S TI Environmental Sr-90 measurements SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS LA English DT Article; Proceedings Paper CT 7th Conference on Accelerator Mass Spectrometry CY MAY 20-24, 1996 CL TUCSON, AZ SP AMS ID STRONTIUM; SAMPLES AB Sr-90 (T-1/2 = 28.5 years) is a long-lived radionuclide produced in nuclear fission. Fast radiochemical detection of Sr-90 in environmental samples is not feasible using current analytical methods. Accelerator Mass Spectrometry (AMS) measurements of Sr-90 were made with the Rehovot 14UD Pelletron accelerator at a terminal voltage of 11 or 12 MV using our standard detection system, Injection of hydride ions (SrH3-) was chosen owing to high beam intensity and low Coulomb explosion effects. Sr-90 ions were identified and discriminated from isobaric Zr-90 by measuring time of flight, total energy and three independent energy-loss signals in an ionization chamber, A reference sample and a ground-water sample were successfully measured. The detection limit determined for a laboratory blank by the residual counts in the Sr-90 region is Sr-90/Sr = 3 x 10(-13), corresponding in practice to (2-4) x 10(7 90)Sr atoms or about 0.5-1 pCi/L samples. C1 SOREQ NRC,IL-81800 YAVNE,ISRAEL. US GEOL SURVEY,IDAHO FALLS,ID 83403. PURDUE UNIV,DEPT CHEM,W LAFAYETTE,IN 47907. RP Paul, M (reprint author), HEBREW UNIV JERUSALEM,RACAH INST PHYS,IL-91904 JERUSALEM,ISRAEL. NR 12 TC 27 Z9 27 U1 0 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-583X J9 NUCL INSTRUM METH B JI Nucl. Instrum. Methods Phys. Res. Sect. B-Beam Interact. Mater. Atoms PD MAR PY 1997 VL 123 IS 1-4 BP 394 EP 399 DI 10.1016/S0168-583X(96)00708-2 PG 6 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Atomic, Molecular & Chemical; Physics, Nuclear SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA WT653 UT WOS:A1997WT65300079 ER PT J AU Friedrich, M Sun, G Grotschel, R Behrisch, R GarciaRosales, C Roberts, ML AF Friedrich, M Sun, G Grotschel, R Behrisch, R GarciaRosales, C Roberts, ML TI Tritium depth profiling in carbon by accelerator mass spectrometry SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS LA English DT Article; Proceedings Paper CT 7th Conference on Accelerator Mass Spectrometry CY MAY 20-24, 1996 CL TUCSON, AZ SP AMS ID HYDROGEN AB A facility for tritium depth profiling measurements by AMS has been installed at the Rossendorf 3 MV Tandetron. Depth profiles are obtained by mechanical scanning of the sputter sample inside a commercial Cs sputter ion source. The deuterium profiles are obtained simultaneously using the injection magnet for mass separation. First results of measurements at carbon tiles from the Garching DD fusion experiment ASDEX-upgrade are presented. The influence of different parameters on the measured profiles is discussed. C1 EURATOM,MAX PLANCK INST PLASMAPHYS,D-85749 GARCHING,GERMANY. LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94551. RP Friedrich, M (reprint author), ROSSENDORF INC,PF 510119,D-01314 DRESDEN,GERMANY. NR 9 TC 13 Z9 13 U1 1 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-583X J9 NUCL INSTRUM METH B JI Nucl. Instrum. Methods Phys. Res. Sect. B-Beam Interact. Mater. Atoms PD MAR PY 1997 VL 123 IS 1-4 BP 410 EP 413 DI 10.1016/S0168-583X(96)00404-1 PG 4 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Atomic, Molecular & Chemical; Physics, Nuclear SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA WT653 UT WOS:A1997WT65300082 ER PT J AU Kaplin, VV Moran, M Pivovarov, YL Rozum, EI Uglov, SR AF Kaplin, VV Moran, M Pivovarov, YL Rozum, EI Uglov, SR TI Coherent X-ray radiation of 5.7 MeV electrons from a (002) mosaic pyrolytic graphite crystal SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS LA English DT Article AB Coherent X-ray radiation associated with so-called Parametric X-ray Radiation (PXR) has been observed from a mosaic pyrolytic graphite crystal using an electron beam energy of 5.7 MeV. The 1st order (002) PXR reflection under Bragg geometry results in emission of photons with energies peaked near 7 keV, at a large angle theta(D) = 28 degrees with respect to the electron beam. C1 LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA. RP Kaplin, VV (reprint author), INST PHYS NUCL,POB 25,TOMSK 634050,RUSSIA. NR 11 TC 5 Z9 5 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-583X J9 NUCL INSTRUM METH B JI Nucl. Instrum. Methods Phys. Res. Sect. B-Beam Interact. Mater. Atoms PD MAR PY 1997 VL 122 IS 4 BP 625 EP 629 DI 10.1016/S0168-583X(96)00461-2 PG 5 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Atomic, Molecular & Chemical; Physics, Nuclear SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA WN544 UT WOS:A1997WN54400002 ER PT J AU Maruyama, T AF Maruyama, T TI QCD tests with polarized beams SO NUCLEAR PHYSICS B LA English DT Article; Proceedings Paper CT Proceedings of the 4th Montpellier Conference on Quantum Chromodynamics (QCD 96) CY JUL 04-12, 1996 CL MONTPELLIER, FRANCE SP European Commission, Brussels ID E+E ANNIHILATION; JET HANDEDNESS AB We present three QCD studies performed by the SLD experiment at SLAG, utilizing the highly polarized SLC electron beam. We examined particle production differences in light quark and antiquark hemispheres, and observed more high momentum baryons and K-'s than antibaryons and K+'s in quark hemispheres, consistent with the ''leading particle'' hypothesis. We performed a search for jet handedness in light q- and (q) over bar-jets. Assuming Standard Model values of quark polarization in Z(0) decays, we have set an improved upper limit on the analysing power of the handedness method. We studied the correlation between the Z(0) spin and the event-plane orientation in polarized Z(0) decays into three jets. The CP-even and T-odd triple product <(S)over right arrow (Z)>.(<(k)over right arrow (1)> x <(k)over right arrow (2)>) formed from the two fastest jet momenta, <(k)over right arrow (1)> and <(k)over right arrow (2)>, and the Z(0) polarization vector <(S)over right arrow (Z)>, is sensitive to physics beyond the Standard Model. RP Maruyama, T (reprint author), STANFORD LINEAR ACCELERATOR CTR,STANFORD,CA 94309, USA. NR 15 TC 0 Z9 0 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0550-3213 J9 NUCL PHYS B JI Nucl. Phys. B PD MAR PY 1997 SU 54 BP 20 EP 24 PG 5 WC Physics, Particles & Fields SC Physics GA WQ698 UT WOS:A1997WQ69800007 ER PT J AU Plunkett, R AF Plunkett, R TI High E(T) jets at CDF SO NUCLEAR PHYSICS B LA English DT Article; Proceedings Paper CT Proceedings of the 4th Montpellier Conference on Quantum Chromodynamics (QCD 96) CY JUL 04-12, 1996 CL MONTPELLIER, FRANCE SP European Commission, Brussels ID COLLISIONS AB Results of QCD tests using hadronic jets from hard parton-parton collisions at the Fermilab Tevatron are presented. CDF has measured the inclusive jet cross-section as a function of jet transverse energy and collision center of mass energy. The angular distribution of dijet production has also been measured. RP Plunkett, R (reprint author), FERMILAB NATL ACCELERATOR LAB,POB 500,BATAVIA,IL 60510, USA. NR 16 TC 0 Z9 0 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0550-3213 J9 NUCL PHYS B JI Nucl. Phys. B PD MAR PY 1997 SU 54 BP 81 EP 85 PG 5 WC Physics, Particles & Fields SC Physics GA WQ698 UT WOS:A1997WQ69800019 ER PT J AU Beneke, M Braun, VM Magnea, L AF Beneke, M Braun, VM Magnea, L TI On the infrared sensitivity of the longitudinal cross section in e(+)e(-) annihilation SO NUCLEAR PHYSICS B LA English DT Article; Proceedings Paper CT Proceedings of the 4th Montpellier Conference on Quantum Chromodynamics (QCD 96) CY JUL 04-12, 1996 CL MONTPELLIER, FRANCE SP European Commission, Brussels ID HADRONIC EVENT SHAPES; FRAGMENTATION FUNCTIONS; POWER CORRECTIONS; QCD; RESUMMATION; MASS AB We have calculated the contributions proportional to beta(0)(n) alpha(s)(n+1) to the longitudinal fragmentation function in e(+)e(-) annihilation to all orders of perturbation theory. We use this result to estimate higher-order perturbative e corrections and nonperturbative corrections to the longitudinal cross section sigma(L) and discuss the prospects of determining sigma(s) from sigma(L). The structure of infrared renormalons in the perturbative expansion suggests that the longitudinal cross section for hadron production with fixed momentum fraction s receives nonperturbative contributions of order 1/(x(2)Q(2)), whereas the total cross section has a larger, 1/Q correction. This correction arises from very large longitudinal distances and is related to the behaviour of the Borel integral for the cross section with fixed x at large values of the Borel parameter. C1 NORDITA,DK-2100 COPENHAGEN,DENMARK. RP Beneke, M (reprint author), STANFORD LINEAR ACCELERATOR CTR,POB 4349,STANFORD,CA 94309, USA. OI Magnea, Lorenzo/0000-0002-7016-2756 NR 14 TC 1 Z9 1 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0550-3213 J9 NUCL PHYS B JI Nucl. Phys. B PD MAR PY 1997 SU 54 BP 183 EP 188 PG 6 WC Physics, Particles & Fields SC Physics GA WQ698 UT WOS:A1997WQ69800037 ER PT J AU Wang, R AF Wang, R TI Semileptonic branching fraction and hadronic width of the B mesons in light of the new CLEO observation of b->(D)over-bar-X SO NUCLEAR PHYSICS B LA English DT Article; Proceedings Paper CT Proceedings of the 4th Montpellier Conference on Quantum Chromodynamics (QCD 96) CY JUL 04-12, 1996 CL MONTPELLIER, FRANCE SP European Commission, Brussels ID RATIO AB This talk reports the latest CLEO observation of (D) over bar production in b decays, which provides new insite of the QCD interactions in heavy quark systems. The observed B semileptonic branching fraction has been significantly lower than QCD expectations, as was confirmed by recent lepton-lepton correclation studies at various experiments that removed most of the model dependence in previous generation measurements. One possible explanation to accommodate this lepton shortage or a wider hadronic width of B mesons is that the process b --> c(c) over bars$ contributes at a higher rate than expected. That explanation, however, predicts more charm production in than is observed. Using lepton tags in B events this analysis measures the fraction of b --> <(D)over bar X> in addition to b --> DX. The first observation of (B) over bar --> <(D)over bar DX> has profound implications to both experiment and theory. RP Wang, R (reprint author), STANFORD LINEAR ACCELERATOR CTR,STANFORD,CA 94309, USA. NR 8 TC 0 Z9 0 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0550-3213 J9 NUCL PHYS B JI Nucl. Phys. B PD MAR PY 1997 SU 54 BP 261 EP 265 PG 5 WC Physics, Particles & Fields SC Physics GA WQ698 UT WOS:A1997WQ69800052 ER PT J AU Radyushkin, AV Ruskov, R AF Radyushkin, AV Ruskov, R TI QCD sum rule calculation of gamma gamma*->pi(0) transition form factor SO NUCLEAR PHYSICS B LA English DT Article; Proceedings Paper CT Proceedings of the 4th Montpellier Conference on Quantum Chromodynamics (QCD 96) CY JUL 04-12, 1996 CL MONTPELLIER, FRANCE SP European Commission, Brussels ID ASYMPTOTIC-BEHAVIOR; EXCLUSIVE PROCESSES; RESONANCE PHYSICS; MODEL AB We discuss QCD sum rule analysis of the form factor F-gamma*gamma*pi o (q(2), Q(2)) in the region where virtuality of one of the spacelike photons is small q(2) much less than 1 GeV2 while another is large: Q(2) greater than or similar to 1 GeV2. Our approach, in contrast to pQCD, does not require explicit assumptions about the shape of the pion distribution amplitude phi(pi)(x). The absolute value of the 1/Q(2) term obtained in this paper favours phi(pi)(x) close to the asymptotic form phi(pi)(a3)(x) = 6f(pi)x(1 - x). C1 THOMAS JEFFERSON NATL ACCELERATOR FACIL,NEWPORT NEWS,VA 23606. JOINT INST NUCL RES DUBNA,THEORET PHYS LAB,DUBNA,RUSSIA. RP Radyushkin, AV (reprint author), OLD DOMINION UNIV,DEPT PHYS,NORFOLK,VA 23529, USA. NR 24 TC 0 Z9 0 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0550-3213 J9 NUCL PHYS B JI Nucl. Phys. B PD MAR PY 1997 SU 54 BP 327 EP 332 PG 6 WC Physics, Particles & Fields SC Physics GA WQ698 UT WOS:A1997WQ69800062 ER PT J AU West, GB AF West, GB TI Glueballs and non-perturbative QCD SO NUCLEAR PHYSICS B LA English DT Article; Proceedings Paper CT Proceedings of the 4th Montpellier Conference on Quantum Chromodynamics (QCD 96) CY JUL 04-12, 1996 CL MONTPELLIER, FRANCE SP European Commission, Brussels ID SCALAR GLUEBALL; HADRON MASSES; HIGGS-BOSON; INEQUALITIES; DECAY AB Theoretical ideas related to the existence of glueballs in QCD are reviewed. These include non-perturbative phenomena, such as confinement, instantons, vacuum condensates and renormalous. We also discuss glueball dominance of the trace of the stress-tensor, the mass content of the nucleon and a theorem on the lightest glueball state. RP West, GB (reprint author), LOS ALAMOS NATL LAB,POB 1663,LOS ALAMOS,NM 87501, USA. NR 23 TC 5 Z9 5 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0550-3213 J9 NUCL PHYS B JI Nucl. Phys. B PD MAR PY 1997 SU 54 BP 353 EP 361 PG 9 WC Physics, Particles & Fields SC Physics GA WQ698 UT WOS:A1997WQ69800067 ER PT J AU Eaton, SL Beard, CA Adams, ML AF Eaton, SL Beard, CA Adams, ML TI Comparison of LAHET code system calculations with experimental results for protons of energies less than 50 MeV incident on copper and iron SO NUCLEAR SCIENCE AND ENGINEERING LA English DT Article AB The LAHET code system calculations and experimental results for proton interactions with an energy <50 MeV are compared. For these energies, the theories behind the LAHET models are not applicable. Three quantities compared are (a) the magnitude of the neutron yield generated through proton interactions, (b) the energy and angular distributions of the resultant neutrons, and (c) the residual nuclei produced by proton interactions (spallation products). The comparisons are for protons incident on iron and copper, except in the case of the energy and angular distributions, which are calculated only for iron. The neutron yields predicted by LAHET agree with published measurements to within 50% for both materials. For iron, the predicted energy and angular distributions agree To within a factor of 3. Finally, the predicted spallation product yields of both materials agree with measurements to within a factor of 4. C1 TEXAS A&M UNIV,COLLEGE STN,TX 77843. RP Eaton, SL (reprint author), LOS ALAMOS NATL LAB,MAIL STOP K551,LOS ALAMOS,NM 87545, USA. NR 7 TC 3 Z9 3 U1 0 U2 0 PU AMER NUCLEAR SOCIETY PI LA GRANGE PK PA 555 N KENSINGTON AVENUE, LA GRANGE PK, IL 60525 SN 0029-5639 J9 NUCL SCI ENG JI Nucl. Sci. Eng. PD MAR PY 1997 VL 125 IS 3 BP 249 EP 256 PG 8 WC Nuclear Science & Technology SC Nuclear Science & Technology GA WJ762 UT WOS:A1997WJ76200001 ER PT J AU Ramone, GL Adams, ML Nowak, PF AF Ramone, GL Adams, ML Nowak, PF TI A transport synthetic acceleration method for transport iterations SO NUCLEAR SCIENCE AND ENGINEERING LA English DT Article ID DISCRETE-ORDINATES EQUATIONS; S-N EQUATIONS; DIFFUSION; MULTIGROUP AB A family of transport synthetic acceleration (TSA) methods for iteratively solving within group scattering problems is presented. A single iteration in these schemes consists of a transport sweep followed by a low-order calculation, which itself is a simplified transport problem. The method for isotropic-scattering problems in X-Y geometry is described. Our Fourier analysis of a mode[problem for equations with no spatial discretization shows that a previously proposed TSA method is unstable in two dimensions but that our modifications make it stable and rapidly convergent. The same procedure for discretized transport equations, using the step characteristic and two bilinear discontinuous methods, shows that discretization enhances TSA performance. A conjugate gradient algorithm for the low-order problem is described, a crude quadrature set for the low-order problem is proposed, and the number of low-order iterations per high-order sweep is limited to a relatively small value. These features lead to simple and efficient improvements to the method. TSA is tested on a series of problems, and a set of parameters is proposed for which the method behaves especially well. TSA achieves a substantial reduction in computational cost over source iteration, regardless of discretization parameters or material properties, and this reduction increases with the difficulty of the problem. C1 LAWRENCE LIVERMORE NATL LAB, LIVERMORE, CA 94551 USA. RP TEXAS A&M UNIV, DEPT NUCL ENGN, COLLEGE STN, TX 77843 USA. NR 22 TC 32 Z9 36 U1 0 U2 1 PU AMER NUCLEAR SOC PI LA GRANGE PK PA 555 N KENSINGTON AVE, LA GRANGE PK, IL 60526 USA SN 0029-5639 EI 1943-748X J9 NUCL SCI ENG JI Nucl. Sci. Eng. PD MAR PY 1997 VL 125 IS 3 BP 257 EP 283 PG 27 WC Nuclear Science & Technology SC Nuclear Science & Technology GA WJ762 UT WOS:A1997WJ76200002 ER PT J AU Penland, RC Azmy, YY Turinsky, PJ AF Penland, RC Azmy, YY Turinsky, PJ TI Error analysis of the nodal expansion method for solving the neutron diffusion equation SO NUCLEAR SCIENCE AND ENGINEERING LA English DT Article AB An error analysis is presented of the quartic polynomial nodal expansion method for solving the one-dimensional, neutron diffusion equation that originates from employing the transverse integration technique. Error bound expressions are determined for the L(infinity) error norms associated with the nodal surface flux and various moments of the nodal flux. Employing several test problems, these global error bounds were found to be conservative, but not excessively, in bounding the true errors. Utilizing a functional form of the local error estimate for the node average flux, it is shown that a mesh-doubling technique can be effectively utilized to estimate the required cell size for uniform mesh refinement to achieve a specified global error fidelity. When employed in conjunction with a multigrid acceleration technique, this provides the foundations upon which to develop an adaptive spatial mesh algorithm. C1 N CAROLINA STATE UNIV,RALEIGH,NC 27695. OAK RIDGE NATL LAB,OAK RIDGE,TN 37831. NR 16 TC 1 Z9 1 U1 0 U2 0 PU AMER NUCLEAR SOCIETY PI LA GRANGE PK PA 555 N KENSINGTON AVENUE, LA GRANGE PK, IL 60525 SN 0029-5639 J9 NUCL SCI ENG JI Nucl. Sci. Eng. PD MAR PY 1997 VL 125 IS 3 BP 284 EP 299 PG 16 WC Nuclear Science & Technology SC Nuclear Science & Technology GA WJ762 UT WOS:A1997WJ76200003 ER PT J AU Vilim, RB Garcia, HE AF Vilim, RB Garcia, HE TI Hierarchical control of reactor inlet temperature in pool-type plants .1. Physics of control SO NUCLEAR SCIENCE AND ENGINEERING LA English DT Article AB Next generation pool-type power plants will require advanced control techniques to meet operational and safety goals. This is the conclusion after conducting control experiments in the Experimental Breeder Reactor II (EER-II) to demonstrate a supervisory so-called passive control scheme. The proportional-integral-derivative controller in EER-II did not adequately compensate for disturbances to inlet temperature that occurred during normal power changes. The key to better control is to take into account the stratification and energy interchange mechanisms in the primary pool through which these disturbances feed. A model-based control approach for solving this problem is described. A lumped parameter model of the EBR-II primary pool is developed and validated using experimental data. A disturbance rejection method is then used to design a controller that minimizes the effect of those disturbances that cause poor setpoint tracking. The implementation of the controller and results are given in a companion paper. C1 ARGONNE NATL LAB,IDAHO FALLS,ID 83403. RP Vilim, RB (reprint author), ARGONNE NATL LAB,9700 S CASS AVE,ARGONNE,IL 60439, USA. NR 11 TC 0 Z9 0 U1 0 U2 0 PU AMER NUCLEAR SOCIETY PI LA GRANGE PK PA 555 N KENSINGTON AVENUE, LA GRANGE PK, IL 60525 SN 0029-5639 J9 NUCL SCI ENG JI Nucl. Sci. Eng. PD MAR PY 1997 VL 125 IS 3 BP 324 EP 336 PG 13 WC Nuclear Science & Technology SC Nuclear Science & Technology GA WJ762 UT WOS:A1997WJ76200006 ER PT J AU Garcia, HE Vilim, RB Dean, EM AF Garcia, HE Vilim, RB Dean, EM TI Hierarchical control of reactor inlet temperature in pool-type plants .2. Implementation and results SO NUCLEAR SCIENCE AND ENGINEERING LA English DT Article AB The implementation of a computer-based controller for regulating reactor inlet temperature (RIT) in a pool-type power plant is described. The mathematical description of the controller is given in a companion paper. The elements of the control system are organized in a master-follower hierarchical architecture that takes advantage of existing in-plant hardware and software to minimize the need for plant modifications. Low-level control algorithms are executed on existing local digital controllers (followers) with the high-level algorithms executed on a new plant supervisory computer (master). A distributed computing strategy provides integration of the existing and additional computer platforms. The control system operates by having the master controller first estimate the secondary sodium flow needed to achieve a given RIT. The estimated flow is then used as a setpoint by the follower controller to regulate sodium flow using a motor-generator pump set. The control system has been implemented in a hardware-in-the-loop (HIL) setup and qualified for operation in the Experimental Breeder Reactor II at Argonne National Laboratory. The HIL results are provided. C1 ARGONNE NATL LAB,ARGONNE,IL 60439. RP Garcia, HE (reprint author), ARGONNE NATL LAB,POB 2528,IDAHO FALLS,ID 83403, USA. NR 12 TC 3 Z9 3 U1 0 U2 1 PU AMER NUCLEAR SOCIETY PI LA GRANGE PK PA 555 N KENSINGTON AVENUE, LA GRANGE PK, IL 60525 SN 0029-5639 J9 NUCL SCI ENG JI Nucl. Sci. Eng. PD MAR PY 1997 VL 125 IS 3 BP 337 EP 347 PG 11 WC Nuclear Science & Technology SC Nuclear Science & Technology GA WJ762 UT WOS:A1997WJ76200007 ER PT J AU Giles, GE AF Giles, GE TI Local analysis technique for the advanced neutron source reactor fuel defect studies SO NUCLEAR TECHNOLOGY LA English DT Article DE heat transfer; nuclear; fuel defects AB The safety analysis for the Advanced Neutron Source Reactor (ANSR) required the development of a new analysis technique to determine fuel integrity and to assure avoidance of critical heat flux (CHF) conditions. The ANSR is a research reactor design intended to provide the highest continuous neutron beam intensity of any reactor in the world. Reliance on previous safety analysis techniques such as those used in the High Flux Isotope Reactor would result in a design that would not meet the requirements. A more accurate but still conservative analysis technique was developed for the ANSR safety analyses. This technique, the local analysis technique (LAT), relaxed some of the overly conservative assumptions of previous hot-spot studies by using a large number of detailed analyses. The conditions used in these analyses were spread over the possible distributions found in specific designs. This technique was used to analyze several core designs to produce confidence in the fuel plate integrity that could be damaged by excessive fuel temperatures and avoidance of CHF conditions. This approach can be used for other reactor designs and should allow increases in the operating power levels. Alternatively, the LAT could be used to demonstrate increased safety margins for present operating conditions. RP Giles, GE (reprint author), OAK RIDGE NATL LAB,POB 2008,MS-6415,OAK RIDGE,TN 37831, USA. NR 8 TC 1 Z9 1 U1 0 U2 0 PU AMER NUCLEAR SOCIETY PI LA GRANGE PK PA 555 N KENSINGTON AVENUE, LA GRANGE PK, IL 60525 SN 0029-5450 J9 NUCL TECHNOL JI Nucl. Technol. PD MAR PY 1997 VL 117 IS 3 BP 306 EP 315 PG 10 WC Nuclear Science & Technology SC Nuclear Science & Technology GA WK119 UT WOS:A1997WK11900005 ER PT J AU Reardon, JT Thompson, LH Sancar, A AF Reardon, JT Thompson, LH Sancar, A TI Rodent UV-sensitive mutant cell lines in complementation groups 6-10 have normal general excision repair activity SO NUCLEIC ACIDS RESEARCH LA English DT Article ID CHINESE-HAMSTER CELLS; DNA-REPAIR; TRANSCRIPTION; NUCLEASE; RECONSTITUTION; DAMAGE; DIMERS AB Mammalian nucleotide excision repair is the primary enzymatic pathway for removing bulky lesions from DNA. The repair reaction involves three main;steps: (i) dual incisions on both sides of the lesion; (ii) excision of the damaged base in an oligonucleotide 24-31 nt in length; (iii) filling in of the post-excision gap and ligation. We have developed assays that probe the I individual steps of the reaction. Using these methods (assays for incision, excision and repair patch synthesis), we demonstrate that the mammalian excision nuclease system removes bulky lesions by incising. mainly at the 22nd-25th phosphodiester bonds 5' and the 3rd-5th phosphodiester bonds 3' of the lesion, thus releasing oligonucleotides primarily 26-29 nt in length. The resulting excision gap is filled in by DNA polymerases delta and epsilon as revealed by the 'phosphorol thioate repair patch assay'. When these assays were employed with cell-free extracts from the moderately UV-sensitive rodent mutants in complementation groups 6-10, we found that these mutants are essentially normal in all three steps of the repair reaction. This leads us to conclude that these cell lines have normal in vitro repair activities and that the defects in these mutants are most likely in genes controlling cellular functions not directly involved in general excision repair. C1 UNIV N CAROLINA, SCH MED, DEPT BIOCHEM & BIOPHYS, CHAPEL HILL, NC 27599 USA. LAWRENCE LIVERMORE NATL LAB, BIOL & BIOTECHNOL RES PROGRAM, LIVERMORE, CA 94551 USA. FU NIGMS NIH HHS [GM32833] NR 39 TC 27 Z9 27 U1 0 U2 0 PU OXFORD UNIV PRESS PI OXFORD PA GREAT CLARENDON ST, OXFORD OX2 6DP, ENGLAND SN 0305-1048 J9 NUCLEIC ACIDS RES JI Nucleic Acids Res. PD MAR 1 PY 1997 VL 25 IS 5 BP 1015 EP 1021 DI 10.1093/nar/25.5.1015 PG 7 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA WM300 UT WOS:A1997WM30000014 PM 9023113 ER PT J AU Marcus, MA Wang, J Thornton, JC Ma, RM Burastero, S Pierson, RN AF Marcus, MA Wang, J Thornton, JC Ma, RM Burastero, S Pierson, RN TI Anthropometrics do not influence dual X-ray absorptiometry (DXA) measurement of fat in normal to obese adults: A comparison with in vivo neutron activation analysis (IVNA) SO OBESITY RESEARCH LA English DT Article DE body composition; body fat mass; in vivo neutron activation analysis; dual energy X-ray absorptiometry (DXA) ID BODY-COMPOSITION MEASUREMENTS; COMPUTED-TOMOGRAPHY; PHOTON-ABSORPTIOMETRY; ABDOMINAL FAT; POTASSIUM; TISSUE; MASS; HYDRODENSITOMETRY; NITROGEN; ASIANS AB Dual-energy X-ray absorptiometry (DXA) is now a commonly used method for the determination of bone mineral status and body composition in humans. The purposes of this study were to compare fat mass by in vivo neutron activation analysis (FM(IVNA)) with that by DXA (FM(DXA)) in an anthropometrically heterogeneous sample of healthy adult men (n=33) and women (n=36) (19 less than or equal to BMI less than or equal to 39), and to determine whether differences in fat mass estimates between the two methods (Delta FM) were attributable to subject anthropometry as defined by several circumference (waist, iliac crest, thigh) and skinfold thickness (umbilical, suprailiac, abdominal) measurements. No significant differences between FM(DXA) and FM(IVNA) were observed in men (p=0.46) or women (p=0.09). The two methods were very highly correlated in both sexes (women r(2)=0.97, p<0.001, men r(2)=0.91, p<0.001), although the regression line for men was significantly different from the line of identity (p=0.043), These results suggest modest trends toward underestimation of FM(DXA) in men when FM(IVNA)<18 kg, and overestimation in men when FM(IVNA)>18 kg. Delta FM (IVNA-DXA) was not significantly related to any combination of skinfold thicknesses and circumferences in either gender. Age explained 27% of the variance in Delta FM for the men (p=0.008). Furthermore, Delta FM was not significantly related to inter-method disparity in total-body bone mineral measurements in men or women (p<0.05). The present study demonstrates strong correlation in fat measurements between IVNA and DXA in men and women ranging from normal to markedly obese. Correction for subject anthropometry does not significantly improve this relationship. C1 COLUMBIA UNIV COLL PHYS & SURG, ST LUKES ROOSEVELT HOSP CTR, BODY COMPOSIT UNIT, DEPT MED, NEW YORK, NY 10025 USA. BROOKHAVEN NATL LAB, UPTON, NY 11973 USA. FU NIDDK NIH HHS [DK-37352] NR 47 TC 7 Z9 7 U1 0 U2 0 PU NORTH AMER ASSOC STUDY OBESITY PI SILVER SPRING PA 8630 FENTON ST, SUITE 918, SILVER SPRING, MD 20910 USA SN 1071-7323 J9 OBES RES JI Obes. Res. PD MAR PY 1997 VL 5 IS 2 BP 122 EP 130 PG 9 WC Endocrinology & Metabolism; Nutrition & Dietetics SC Endocrinology & Metabolism; Nutrition & Dietetics GA WR888 UT WOS:A1997WR88800006 PM 9112247 ER PT J AU Strauss, SY AF Strauss, SY TI Lack of evidence for local adaptation to individual plant clones or site by a mobile specialist herbivore SO OECOLOGIA LA English DT Article DE fine-scale local adaptation; Blepharida rhois; Rhus glabra; larval performance; predation ID HOST-PLANT; POPULATION-STRUCTURE; TETRAOPES-TETRAOPHTHALMUS; GENETIC DIFFERENTIATION; INSECT; SCALE; BEETLE; CHRYSOMELIDAE; RESISTANCE; COLEOPTERA AB Several studies have documented local adaptation by sedentary insects to individual phenotypes of their host plants. Here, I examined whether a similar phenomenon could be found in a mobile, specialized insect, the sumac flea beetle. Previous work has shown that sumac individuals differ in their suitability as hosts for these beetles and that differences have both an environmental and a genetic basis. Using beetle populations collected as eggs from eight different sumac clones along an east-west transect, a reciprocal transfer experiment was conducted to determine whether there was any evidence for local adaptation by beetles to individual plant clones or to site. Variables examined were larval survivorship past first instar, development time, weight at pupation and patterns of predation by enemies. While no evidence for local adaptation was found, there were significant effects of plant clone on which larvae developed, origin of the larval population and the interaction of these effects on larval performance. For larval weight at pupation, there was also some indication that trade-offs may exist in ability of larvae to use different host plant clones. In addition, there were significant environmental effects on several measures of larval performance. Predation rates differed by plant clone, but not by site or with respect to origin of larvae. While no evidence for local adaptation was found in this study, prerequisites for finding such patterns may exist in this system. RP Strauss, SY (reprint author), LAWRENCE LIVERMORE NATL LAB,SECT ECOL & EVOLUT,2320 STORER HALL,DAVIS,CA 95616, USA. RI Strauss, Sharon /J-1827-2012; OI Strauss, Sharon/0000-0002-6117-4085 NR 34 TC 31 Z9 31 U1 2 U2 8 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 SN 0029-8549 J9 OECOLOGIA JI Oecologia PD MAR PY 1997 VL 110 IS 1 BP 77 EP 85 DI 10.1007/s004420050135 PG 9 WC Ecology SC Environmental Sciences & Ecology GA WP452 UT WOS:A1997WP45200010 PM 28307471 ER PT J AU Helton, JC Anderson, DR Marietta, MG Rechard, RP AF Helton, JC Anderson, DR Marietta, MG Rechard, RP TI Performance assessment for the Waste Isolation Pilot Plant: From regulation to calculation for 40 CFR 191.13 SO OPERATIONS RESEARCH LA English DT Article ID EPA RELEASE LIMITS; SENSITIVITY ANALYSIS; UNCERTAINTY; DISPOSAL; RISK; PROBABILITIES; SAFETY AB The Waste Isolation Pilot Plant (WIPP) is being developed by the U.S. Department of Energy as a disposal facility for transuranic waste and must comply with several environmental regulations, including the U.S. Environmental Protection Agency's standard for geologic disposal of radioactive waste (40 CFR 191). Procedures used in recent performance assessments for the WIPP to translate regulations into a structure that facilitates quantitative analysis we described. Topics considered include (I) development of a clear conceptual representation for problems that are initially ill-defined, (2) conversion of qualitative guidance into numerical calculations, (3) explicit incorporation of different types of uncertainty (i.e., aleatory and epistemic) into analysis outcomes, (4) requirements for efficient computation and models at different levels of complexity, (5) use of sensitivity analysis to guide additional data collection and future calculations, (6) requirements for results to be presented and explained to audiences with different interests and levels of sophistication, and (7) ambiguity with respect to final uses of the analysis and its outcomes. The need to address similar concepts and problems arises in many analyses. C1 SANDIA NATL LABS,ALBUQUERQUE,NM 87185. RP Helton, JC (reprint author), ARIZONA STATE UNIV,TEMPE,AZ 85287, USA. NR 57 TC 22 Z9 22 U1 1 U2 3 PU INST OPERATIONS RESEARCH MANAGEMENT SCIENCES PI LINTHICUM HTS PA 901 ELKRIDGE LANDING RD, STE 400, LINTHICUM HTS, MD 21090-2909 SN 0030-364X J9 OPER RES JI Oper. Res. PD MAR-APR PY 1997 VL 45 IS 2 BP 157 EP 177 DI 10.1287/opre.45.2.157 PG 21 WC Management; Operations Research & Management Science SC Business & Economics; Operations Research & Management Science GA XD308 UT WOS:A1997XD30800001 ER PT J AU Rao, NSV AF Rao, NSV TI Nadaraya-Watson estimator for sensor fusion SO OPTICAL ENGINEERING LA English DT Article DE sensor fusion; fusion rule estimation; empirical estimation; Nadaraya-Watson estimator ID REGRESSION AB In a system of N sensors, the sensor S-j, j=1,2,..., N, outputs Y-(j) is an element of [0,1], according to an unknown probability density p(j)(Y-(j)parallel to X), corresponding to input X is an element of [0,1]. A training n-sample (X(1),Y-1),(X(2),Y-2),...,(X(n),Y-n) is given where Y-i=(Y-i((1)),Y-i((2)),..., Y-i((N))) such that Y-i((j)) is the output of S-j in response to input X(i). The problem is to estimate a fusion rule f:[0,1](N)-->[0,1], based on the sample, such that the expected square error I(f) =integral[X-f(Y)](2)p(Y parallel to X)p(X)dY((1)) dY((2))... dY((N))dX is minimized over a family of functions F with uniformly bounded modulus of smoothness, where Y=(Y-(1), Y-(2),..., Y-(N)). Let f* minimize I(.) over F; f* cannot be computed since the underlying densities are unknown. We estimate the sample size sufficient to ensure that Nadaraya-Watson estimator (f) over cap satisfies P[I((f) over cap)-I(f*)> epsilon]0 and delta, 0< delta<1. (C) 1997 Society of Photo-Optical Instrumentation Engineers. RP Rao, NSV (reprint author), OAK RIDGE NATL LAB,CTR ENGN SYST ADV RES,OAK RIDGE,TN 37831, USA. OI Rao, Nageswara/0000-0002-3408-5941 NR 23 TC 10 Z9 10 U1 0 U2 0 PU SOC PHOTO-OPTICAL INSTRUMENTATION ENGINEERS PI BELLINGHAM PA PO BOX 10, BELLINGHAM, WA 98227-0010 SN 0091-3286 J9 OPT ENG JI Opt. Eng. PD MAR PY 1997 VL 36 IS 3 BP 642 EP 647 DI 10.1117/1.601136 PG 6 WC Optics SC Optics GA WN456 UT WOS:A1997WN45600003 ER PT J AU VanHoozen, CM Peeke, PG Taubeneck, M Frey, CF Halsted, CH AF VanHoozen, CM Peeke, PG Taubeneck, M Frey, CF Halsted, CH TI Efficacy of enzyme supplementation after surgery for chronic pancreatitis SO PANCREAS LA English DT Article DE enzyme supplementation; chronic pancreatitis; local resection longitudinal pancreaticojejunostomy; nutritional status ID NEAR-TOTAL PANCREATECTOMY; LONGITUDINAL PANCREATICOJEJUNOSTOMY; ALCOHOLIC PANCREATITIS; DUCT DRAINAGE; RESECTION; PANCREATICODUODENECTOMY; DYSFUNCTION; ABSORPTION; HEAD AB Although surgical procedures that improve pancreatic drainage alleviate abdominal pain in the vast majority of patients with chronic pancreatitis, postoperative absorption and nutritional status are less predictable. The present study was designed to determine the efficacy of pancreatic enzyme supplementation in maintaining postoperative digestion and nutrition in patients who had received the local resection-longitudinal pancreaticojejunostomy (LR-LPJ) procedure for chronic pancreatitis. We evaluated nutritional status and intestinal absorption in 11 patients who had undergone LR-LPJ. The efficacy of postoperative pancreatic enzyme supplementation was studied by measurements of intestinal absorption and nutritional status at baseline, after 4 weeks of individualized daily dosage of pancreatin (Creon), and after an additional 4 weeks of randomization to receive another 4 weeks of pancreatin or placebo. All patients demonstrated abnormal digestion of fat, protein, and total energy at baseline 3 weeks after surgery, Pancreatin supplementation significantly improved the coefficients of absorption of dietary fat and total energy over the next 4 weeks. Between 4 and 8 weeks, pancreatin significantly improved protein absorption and nitrogen balance, whereas placebo substitution worsened the absorption of dietary fat and total energy. Nutritional status was not significantly altered over the 8-week study period, although four patients receiving pancreatin gained more than 3.6 kg body weight. The data suggest that long-term postoperative pancreatic enzyme supplementation is both efficacious and necessary in chronic pancreatitis patients after LR-LPJ. C1 LAWRENCE LIVERMORE NATL LAB,SCH MED,DIV CLIN NUTR & METAB,DEPT INTERNAL MED,DAVIS,CA 95616. LAWRENCE LIVERMORE NATL LAB,DEPT SURG,DAVIS,CA 95616. FU NIDDK NIH HHS [DK07355, DK 35747] NR 39 TC 30 Z9 31 U1 0 U2 1 PU LIPPINCOTT-RAVEN PUBL PI PHILADELPHIA PA 227 EAST WASHINGTON SQ, PHILADELPHIA, PA 19106 SN 0885-3177 J9 PANCREAS JI Pancreas PD MAR PY 1997 VL 14 IS 2 BP 174 EP 180 DI 10.1097/00006676-199703000-00010 PG 7 WC Gastroenterology & Hepatology SC Gastroenterology & Hepatology GA WK691 UT WOS:A1997WK69100010 PM 9057190 ER PT J AU Medlin, DL Carter, CB Angelo, JE Mills, MJ AF Medlin, DL Carter, CB Angelo, JE Mills, MJ TI Climb and glide of a/3<111> dislocations in an aluminium Sigma=3 boundary SO PHILOSOPHICAL MAGAZINE A-PHYSICS OF CONDENSED MATTER STRUCTURE DEFECTS AND MECHANICAL PROPERTIES LA English DT Article ID GRAIN-BOUNDARIES AB High-resolution transmission electron microscopy observations are presented of the motion of grain-boundary dislocations within an aluminium Sigma = 3[0 (0) over bar 1] bicrystal. The observations show the glide of dissociated a/3[111] grain-boundary dislocations on the incoherent Sigma = 3(2<(11)over bar>) boundary. These dislocations are subsequently incorporated into a growing coherent two lamella where further motion occurs by climb. Analysis of the tip of the advancing twin suggests that nucleation of coherent twin segments may be initiated by the absorption of a lattice dislocation in the boundary with the subsequent dissociation to form a/3[111] and a/6[(2) over bar 11] grain-boundary dislocations. C1 UNIV MINNESOTA,DEPT CHEM ENGN & MAT SCI,MINNEAPOLIS,MN 55455. RP Medlin, DL (reprint author), SANDIA NATL LABS,LIVERMORE,CA 94551, USA. RI Carter, C. Barry/E-6478-2010 OI Carter, C. Barry/0000-0003-4251-9102 NR 12 TC 37 Z9 38 U1 1 U2 12 PU TAYLOR & FRANCIS LTD PI LONDON PA ONE GUNPOWDER SQUARE, LONDON, ENGLAND EC4A 3DE SN 0141-8610 J9 PHILOS MAG A JI Philos. Mag. A-Phys. Condens. Matter Struct. Defect Mech. Prop. PD MAR PY 1997 VL 75 IS 3 BP 733 EP 747 PG 15 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering; Physics, Applied; Physics, Condensed Matter SC Materials Science; Metallurgy & Metallurgical Engineering; Physics GA WN480 UT WOS:A1997WN48000009 ER PT J AU Mitra, A Chen, ZJ Laabs, F Jiles, DC AF Mitra, A Chen, ZJ Laabs, F Jiles, DC TI Micromagnetic Barkhausen emissions in 2 center dot 25 wt% Cr-1wt% Mo steel subjected to creep SO PHILOSOPHICAL MAGAZINE A-PHYSICS OF CONDENSED MATTER STRUCTURE DEFECTS AND MECHANICAL PROPERTIES LA English DT Article ID NONDESTRUCTIVE EVALUATION; FERROMAGNETIC HYSTERESIS; MAGNETIC-PROPERTIES; NOISE GENERATION; STRESS; SIGNALS AB Micromagnetic Barkhausen emissions have been measured from a number of specimens of Cr-Mo steel in order to study the effects of creep. Creep causes changes in the microstructure of materials as a result of exposure to a high temperature and pressure. Scanning electron micrographs showed that all the specimens were at an early stage of creep. The number density of cavities in specimens which were taken from the outer surface of the pipe was lower than in specimens taken from the inner surface, indicating lower creep on the outer surface. Rms and peak-to-peak voltages of Barkhausen emissions were found to increase from the outside to the inside of the pipe, indicating that these emissions increase with increasing level of creep. Segregation of impurities, which takes place during creep, was considered to be the primary cause of the increase in Barkhausen emission signals. A model has been developed which showed that Barkhausen voltage should increase up to a critical value of the number density of cavities, beyond which it should decrease. As the specimens measured in this study were in the initial stage of creep, only an increase in Barkhausen voltage (rms and peak to peak) was observed with creep across the range of specimens investigated. In the experimental measurements an angular variation in rms voltage was also observed which was explained by the orientation of the easy magnetization axis due to the development of long-range residual stresses in a direction different from the pipe axis. C1 NATL MET LAB,MAGNET GRP,JAMSHEDPUR 831007,BIHAR,INDIA. RP Mitra, A (reprint author), IOWA STATE UNIV SCI & TECHNOL,AMES LAB,AMES,IA 50011, USA. RI Jiles, David/H-9548-2012; Sahu, Anjani/E-7590-2015 NR 16 TC 6 Z9 6 U1 0 U2 0 PU TAYLOR & FRANCIS LTD PI LONDON PA ONE GUNPOWDER SQUARE, LONDON, ENGLAND EC4A 3DE SN 0141-8610 J9 PHILOS MAG A JI Philos. Mag. A-Phys. Condens. Matter Struct. Defect Mech. Prop. PD MAR PY 1997 VL 75 IS 3 BP 847 EP 859 PG 13 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering; Physics, Applied; Physics, Condensed Matter SC Materials Science; Metallurgy & Metallurgical Engineering; Physics GA WN480 UT WOS:A1997WN48000016 ER PT J AU Frase, HN Nagel, LJ Robertson, JL Fultz, B AF Frase, HN Nagel, LJ Robertson, JL Fultz, B TI Vibrational density of states of nanocrystalline Ni3Fe SO PHILOSOPHICAL MAGAZINE B-PHYSICS OF CONDENSED MATTER STATISTICAL MECHANICS ELECTRONIC OPTICAL AND MAGNETIC PROPERTIES LA English DT Article ID X-RAY-DIFFRACTION; INTRINSIC INSTABILITY; NEUTRON-SCATTERING; GRAIN-BOUNDARIES; CRYSTALLINE; METALS AB We measured inelastic neutron scattering spectra for two states of Ni3Fe: firstly as milled, when the material had a characteristic nanocrystallite size of 9 nm; secondly annealed, when the material had a characteristic crystallite size of 30 nm. The nanocrystalline material showed an enhancement by a factor of two in it density of states (DOS) at energies below 15 meV, and some broadening of its longitudinal peak at 33 meV The differences between the vibrational DOSs of the nanocrystalline and annealed materials provide a difference in vibrational entropy of 0.18k(B) atom(-1) at high temperatures. C1 OAK RIDGE NATL LAB,OAK RIDGE,TN 37831. RP Frase, HN (reprint author), CALTECH,MAIL 138-178,PASADENA,CA 91125, USA. NR 26 TC 36 Z9 36 U1 0 U2 4 PU TAYLOR & FRANCIS LTD PI LONDON PA ONE GUNPOWDER SQUARE, LONDON, ENGLAND EC4A 3DE SN 0141-8637 J9 PHILOS MAG B JI Philos. Mag. B-Phys. Condens. Matter Stat. Mech. Electron. Opt. Magn. Prop. PD MAR PY 1997 VL 75 IS 3 BP 335 EP 347 DI 10.1080/13642819708202322 PG 13 WC Materials Science, Multidisciplinary; Mechanics; Physics, Applied; Physics, Condensed Matter SC Materials Science; Mechanics; Physics GA WN479 UT WOS:A1997WN47900003 ER PT J AU Katsnelson, MI Sigalas, M Trefilov, AV Khromov, KY AF Katsnelson, MI Sigalas, M Trefilov, AV Khromov, KY TI Thermal expansion and the equation of state of Ir and Rh SO PHILOSOPHICAL MAGAZINE B-PHYSICS OF CONDENSED MATTER STATISTICAL MECHANICS ELECTRONIC OPTICAL AND MAGNETIC PROPERTIES LA English DT Article ID TOTAL-ENERGY; METALS; IRIDIUM AB The simplest anharmonic characteristics of Ir and Rh are discussed in the framework of a previously developed simple pseudopotential model which describes the elastic moduli, the phonon spectra and the lattice heat capacity in the harmonic approximation of these metals successfully. The microscopic Gruneisen parameters, the dependences of the elastic moduli on pressure, the coefficient of thermal expansion and the equations of state at the finite temperatures have been calculated. The ab initio calculations of the energy-band structure and the equation of state for Ir at T = 0 have been done to test the model for adequacy at high pressures. The values of different contributions (zero-point oscillations, quasiharmonic, etc.) in the considered thermodynamic characteristics of Ir and Rh are discussed. C1 IOWA STATE UNIV SCI & TECHNOL,AMES LAB,AMES,IA 50011. IV KURCHATOV ATOM ENERGY INST,RUSSIAN RES CTR,MOSCOW 123182,RUSSIA. RP Katsnelson, MI (reprint author), INST MET PHYS,EKATERINBURG 620219,RUSSIA. RI Katsnelson, Mikhail/D-4359-2012 NR 16 TC 6 Z9 6 U1 1 U2 4 PU TAYLOR & FRANCIS LTD PI LONDON PA ONE GUNPOWDER SQUARE, LONDON, ENGLAND EC4A 3DE SN 0141-8637 J9 PHILOS MAG B JI Philos. Mag. B-Phys. Condens. Matter Stat. Mech. Electron. Opt. Magn. Prop. PD MAR PY 1997 VL 75 IS 3 BP 407 EP 418 DI 10.1080/13642819708202327 PG 12 WC Materials Science, Multidisciplinary; Mechanics; Physics, Applied; Physics, Condensed Matter SC Materials Science; Mechanics; Physics GA WN479 UT WOS:A1997WN47900008 ER PT J AU Li, AD Stevens, FJ Huppe, HC Kersanach, R Anderson, LE AF Li, AD Stevens, FJ Huppe, HC Kersanach, R Anderson, LE TI Chlamydomonas reinhardtii NADP-linked glyceraldehyde-3-phosphate dehydrogenase contains the cysteine residues identified as potentially domain-locking in the higher plant enzyme and is light activated SO PHOTOSYNTHESIS RESEARCH LA English DT Article DE domain-locking disulfides; light activation; redox-sensitive cysteines; reductive activation ID REDOX-SENSITIVE CYSTEINES; MODULATION; PROTEIN; SPINACH; THIOREDOXIN; PHOTOSYNTHESIS; CHLOROPLASTS; FUTURE; ORIGIN; SITE AB The chloroplastic glyceraldehyde-3-P dehydrogenase (EC 1.2.1.13) of the green alga Chlamydomonas reinhardtii is reductively light activated. Homology modeling indicates that the only potential disulfide-forming cysteine residues in this enzyme are the same cysteine residues suggested to be responsible for redox-sensitivity of the higher plant enzyme (Li D, Stevens FJ, Schiffer M and Anderson LE (1994) Biophys J 67: 29-35). Apparently, the three additional cysteines in the higher plant enzyme are not necessary for light activation. The putative regulatory cysteines are juxtaposed across the domain interface and when oxidized will crosslink the domains. This would be expected to interfere with interdomain movement and catalysis. This is the first report of reductive light activation of this enzyme in a green alga. C1 UNIV ILLINOIS,DEPT BIOL SCI,CHICAGO,IL 60607. ARGONNE NATL LAB,CTR MECH BIOL & BIOTECHNOL,ARGONNE,IL 60439. QUEENS UNIV,DEPT BIOL,KINGSTON,ON K7L 3N6,CANADA. TECH UNIV CAROLO WILHELMINA BRAUNSCHWEIG,INST GENET,D-38023 BRAUNSCHWEIG,GERMANY. NR 36 TC 8 Z9 9 U1 0 U2 0 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0166-8595 J9 PHOTOSYNTH RES JI Photosynth. Res. PD MAR PY 1997 VL 51 IS 3 BP 167 EP 177 PG 11 WC Plant Sciences SC Plant Sciences GA XJ612 UT WOS:A1997XJ61200001 ER PT J AU Hendrey, GR Long, SP McKee, IF Baker, NR AF Hendrey, GR Long, SP McKee, IF Baker, NR TI Can photosynthesis respond to short-term fluctuations in atmospheric carbon dioxide? SO PHOTOSYNTHESIS RESEARCH LA English DT Article DE chlorophyll fluorescence; FACE; global change; photosynthesis; Photosystem II; quantum yield; quenching analysis; rising CO2 concentration; wheat ID MESOPHYLL CONDUCTANCE; ELECTRON-TRANSPORT; ZEA-MAYS; LEAVES AB Rapid and irregular variations of atmospheric CO2 concentrations (c(a)) occur in nature but are often very much more pronounced and frequent when artificially enriching CO2 concentrations in simulating the future atmosphere. Therefore, there is the danger that plant responses at elevated CO2 in fumigation experiments might reflect the increased Frequency and amplitude of fluctuation in concentration as well as the increase in average concentration. Tests were conducted to determine whether the photosynthetic process could sense such fluctuations in c(a). Instantaneous chlorophyll fluorescence (F-t) was monitored for wheat leaves (Triticum aestivum cv. Hereward) exposed to c(a) oscillating symmetrically by 225 mu mol mol(-1) about a c(a) set point concentration of 575 or 650 mu mol mol(-1). No F-t response was detected to half-cycle step changes in c(a) lasting less than two seconds, but at half-cycles of two seconds or longer, the response of F-t was pronounced. In order to determine the in vivo linear electron transport rate (J) the O-2 concentration was maintained at 21 mmol mol(-1) to eliminate photorespiration. J which is directly proportional to the rate of CO2 uptake under these conditions, was not significantly changed at half-cycles of 30 s or less but was decreased by half-cycles of 60 s or longer. It was inferred that if duration of an oscillation is less than 1 minute and is symmetrical with respect to mean CO2 concentration, then there is no effect on current carbon uptake, but oscillations of 1 minute or more decrease photosynthetic CO2 uptake in wheat. C1 UNIV ESSEX,DEPT BIOL,COLCHESTER CO4 3SQ,ESSEX,ENGLAND. RP Hendrey, GR (reprint author), BROOKHAVEN NATL LAB,BIOSYST & PROC SCI DIV,UPTON,NY 11973, USA. RI Long, Stephen/A-2488-2008 OI Long, Stephen/0000-0002-8501-7164 NR 11 TC 25 Z9 25 U1 2 U2 14 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0166-8595 J9 PHOTOSYNTH RES JI Photosynth. Res. PD MAR PY 1997 VL 51 IS 3 BP 179 EP 184 DI 10.1023/A:1005804203928 PG 6 WC Plant Sciences SC Plant Sciences GA XJ612 UT WOS:A1997XJ61200002 ER PT J AU Partensky, F LaRoche, J Wyman, K Falkowski, PG AF Partensky, F LaRoche, J Wyman, K Falkowski, PG TI The divinyl-chlorophyll a/b-protein complexes of two strains of the oxyphototrophic marine prokaryote Prochlorococcus - Characterization and response to changes in growth irradiance SO PHOTOSYNTHESIS RESEARCH LA English DT Article DE cyanobacteria; iron-stress proteins; light-harvesting complexes; photosynthetic antennae; photosystems; prochlorophyte ID PROCHLOROPHYTE PROCHLOROTHRIX-HOLLANDICA; MULTIPLE EVOLUTIONARY ORIGINS; PHOTOSYSTEM-II; THYLAKOID MEMBRANES; ANTENNA PROTEINS; REACTION CENTERS; IRON STARVATION; GREEN-ALGA; LIGHT; SYNECHOCOCCUS AB Apoproteins of the antenna complexes of Prochlorococcus marinus clone SS120 (= CCMP 1375) and Prochlorococcus sp. clone MED4 (= CCMP 1378) cross-reacted with an antibody against the 30 kDa CP 5 complex of Prochlorothrix hollandica antenna. For the MED4 strain, which has a high divinyl-chlorophyll a to divinyl-chlorophyll b (DV-Chl a/b) ratio ranging from 11.4 to 15.0 (w/w), the major antenna proteins had an apparent molecular mass of 32.5 kDa. In contrast for the SS120 strain, which has a low DV-Chl a/b ratio ranging from 1.1 to 2.2, antenna apoproteins were observed in the range 34-38 kDa. For both strains, these apoproteins decreased at high growth irradiance but more markedly in the latter. Partially purified antenna fractions had a DV-Chl a/b ratio ca. 7-fold lower for SS120 than for MED4 at 30 mu mol photons m(-2) s(-1). For both strains, the 77 K fluorescence emission spectra of whole thylakoids displayed a major peak at 685 nm and a broad but very low shoulder above 700 nm. Energetic coupling of the antenna to both PS II and PSI reaction centers was demonstrated for SS120 by the strong contribution of DV-Chl b in both the 77 K excitation fluorescence spectra and the oxidized minus reduced absorption difference spectra of WOO. The PS I to PS II ratio of Prochlorococcus SS120 was determined as being 0.7 +/- 0.1 at low light. C1 UNIV PARIS 06, BIOL STN, F-29682 ROSCOFF, FRANCE. BROOKHAVEN NATL LAB, ENVIRONM BIOPHYS & MOL BIOL PROGRAM, UPTON, NY 11973 USA. RP Partensky, F (reprint author), CNRS, OBSERV OCEANOL ROSCOFF, BP 74, F-29682 ROSCOFF, FRANCE. RI LaRoche, Julie/A-1109-2010; OI Partensky, Frederic/0000-0003-1274-4050 NR 54 TC 43 Z9 51 U1 1 U2 7 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0166-8595 J9 PHOTOSYNTH RES JI Photosynth. Res. PD MAR PY 1997 VL 51 IS 3 BP 209 EP 222 DI 10.1023/A:1005807408161 PG 14 WC Plant Sciences SC Plant Sciences GA XJ612 UT WOS:A1997XJ61200005 ER PT J AU Pedron, D Visentini, G Bozio, R Williams, JM Schlueter, JA AF Pedron, D Visentini, G Bozio, R Williams, JM Schlueter, JA TI Phonon dynamics and superconductivity in the organic crystal kappa-(BEDT-TTF)(2)Cu[N(CN)(2)]Br SO PHYSICA C LA English DT Article DE electron-phonon coupling; organic superconductor; phonon spectrum; Raman scattering ID HIGH-TC SUPERCONDUCTORS; CHARGE-DENSITY WAVES; RAMAN-SCATTERING; BEDT-TTF; TEMPERATURE; SALTS; GAP; KAPPA-(BEDT-TTF)2CUBR; SILICON; CRYSTAL AB A Raman scattering study of the phonon properties of kappa-(BEDT-TTF)(2)Cu[N(CN)(2)]Br, i.e. the radical-cation based organic superconductor with the highest. T-c (11.6 K) at ambient pressure is reported. The low frequency spectral region (10-180 cm(-1)) has been investigated in the temperature range 1.8-100 K. A rich phonon spectrum is observed and polarization data allow a complete symmetry assignment of the bands. Effects associated with the opening of the superconducting gap are identified and distinguished from those due to anharmonicity and to an order-disorder transition. They allow us to single out eight strongly coupled intermolecular phonons and to set an upper limit of ca. 28 cm(-1) for the superconducting gap. C1 ARGONNE NATL LAB,DIV CHEM,ARGONNE,IL 60439. ARGONNE NATL LAB,DIV SCI MAT,ARGONNE,IL 60439. RP Pedron, D (reprint author), UNIV PADUA,DEPT PHYS CHEM,VIA LOREDAN 2,I-35131 PADUA,ITALY. RI Bozio, Renato/E-9066-2012 OI Bozio, Renato/0000-0001-7274-9190 NR 31 TC 28 Z9 28 U1 2 U2 5 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4534 J9 PHYSICA C JI Physica C PD MAR 1 PY 1997 VL 276 IS 1-2 BP 1 EP 8 DI 10.1016/S0921-4534(97)00046-4 PG 8 WC Physics, Applied SC Physics GA WQ092 UT WOS:A1997WQ09200001 ER PT J AU Yoshinari, Y AF Yoshinari, Y TI Anisotropy of the Knight shift at planar oxygen sites in YBa2Cu3Ox: Possible location of the doped holes SO PHYSICA C LA English DT Article DE CuO planes; electronic structure; hole concentration; NMR ID HIGH-TC SUPERCONDUCTORS; ELECTRONIC-STRUCTURE; SPIN SUSCEPTIBILITY; SINGLE-CRYSTAL; NORMAL STATE; CU OXIDES; O-17; RELAXATION; GAP; LA1.85SR0.15CUO4 AB The anisotropy of the Knight shift at planar oxygen sites in four superconducting YBa2Cu3Ox samples has been analyzed based on an ionic model. Characteristic variation of the hyperfine fields as a function of hole concentration was found. Crude analysis suggests that such variation could be assigned to an increase of spin fractions in the oxygen 2p(pi) orbitals, which point perpendicular to the Cu-O bonding. This fact as well as a crystallographic argument may suggest to reconsider second bands associated with the 2p(pi) orbitals, whose symmetry should be distinct from the Cu-O bonding hybrid. RP Yoshinari, Y (reprint author), LOS ALAMOS NATL LAB,POB 1663,LOS ALAMOS,NM 87545, USA. NR 43 TC 8 Z9 8 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4534 J9 PHYSICA C JI Physica C PD MAR 1 PY 1997 VL 276 IS 1-2 BP 147 EP 159 DI 10.1016/S0921-4534(97)00024-5 PG 13 WC Physics, Applied SC Physics GA WQ092 UT WOS:A1997WQ09200019 ER PT J AU Muriel, A Dresden, M AF Muriel, A Dresden, M TI An integral formulation of hydrodynamics SO PHYSICA D LA English DT Article AB An alternate formulation of hydrodynamics is introduced, based on a formal development using projection techniques. A time evolution equation for the single particle distribution function which no longer contains any projection operator is derived, from which hydrodynamic variables are calculated. The resulting formulas for density, fluid velocity, and thermal energy do not satisfy any of the familiar differential equations for the variables. However, it is possible to relate the solutions to the conventional differential equations of hydrodynamics after a set of common assumptions are used. This reduction procedure automatically identifies calculable expressions for the transport coefficients, none of which exhibit divergent behavior as in older studies. We also find an expression for the pressure tenser. We conclude with an outline of a general program that completely bypasses kinetic or conventional continuum hydrodynamics. C1 UNIV PHILIPPINES,CTR FLUID DYNAM,WORLD LAB,LAGUNA,PHILIPPINES. STANFORD UNIV,SLAC,CENT LAB,MENLO PK,CA. RP Muriel, A (reprint author), INST ADV STUDY,SCH NAT SCI,OLDEN LANE,PRINCETON,NJ 08540, USA. NR 14 TC 12 Z9 12 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0167-2789 J9 PHYSICA D JI Physica D PD MAR 1 PY 1997 VL 101 IS 3-4 BP 299 EP 316 DI 10.1016/S0167-2789(96)00181-9 PG 18 WC Mathematics, Applied; Physics, Multidisciplinary; Physics, Mathematical SC Mathematics; Physics GA WK512 UT WOS:A1997WK51200007 ER PT J AU Blundell, SA Cheng, KT Sapirstein, J AF Blundell, SA Cheng, KT Sapirstein, J TI Radiative corrections in atomic physics in the presence of perturbing potentials SO PHYSICAL REVIEW A LA English DT Article ID LAMB-SHIFT CALCULATIONS; STRONG COULOMB FIELD; SELF-ENERGY AB Energy shifts of radiative corrections in atoms due to perturbing potentials are calculated. The potentials considered are a constant magnetic field, the magnetic field of a nucleus, and the Coulomb interaction from other electrons in many-electron atoms. C1 LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550. UNIV NOTRE DAME,DEPT PHYS,NOTRE DAME,IN 46556. RP Blundell, SA (reprint author), CEA,DEPT RECH FONDAMENTALE MAT CONDENSEE,S12A,17 RUE MARTYRS,F-38054 GRENOBLE 9,FRANCE. NR 24 TC 117 Z9 117 U1 1 U2 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 MAR PY 1997 VL 55 IS 3 BP 1857 EP 1865 DI 10.1103/PhysRevA.55.1857 PG 9 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA WN174 UT WOS:A1997WN17400042 ER PT J AU Cartwright, DC Csanak, G AF Cartwright, DC Csanak, G TI Electron-impact excitation from metastable helium: 2 S-1,S-3->n (1,3)L (L=0, 1, 2; n=2, ... ,infinity) SO PHYSICAL REVIEW A LA English DT Article ID INTEGRAL CROSS-SECTIONS; EXCITED ATOMIC TARGETS; MANY-BODY THEORY; N = 2; SCATTERING; STATES AB Integral cross sections for electron-impact excitation from the helium 2 S-3 and 2 S-1 metastable excited states, to all energetically higher S, P, and D excited states, are reported from threshold to 200 eV, These cross sections have been obtained using the distorted-wave approximation. and are compared to other experimental and theoretical results. Special attention is paid to obtaining an adequate representation for the wave functions of the n S-1 excited states (n = 2, 3, and 4). The total integral electronic excitation cross sections from each of these metastable states, summed over rr for fixed L of the final state, and then summed over L, are also reported. These results are combined with other cross-section data to obtain the total inelastic integral cross section for inelastic electron scattering from each of these two helium metastable states. RP Cartwright, DC (reprint author), LOS ALAMOS NATL LAB,DIV THEORET,LOS ALAMOS,NM 87545, USA. NR 17 TC 5 Z9 6 U1 0 U2 0 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 MAR PY 1997 VL 55 IS 3 BP 1962 EP 1970 DI 10.1103/PhysRevA.55.1962 PG 9 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA WN174 UT WOS:A1997WN17400053 ER PT J AU Macek, JH Ihra, W AF Macek, JH Ihra, W TI Threshold law for ionization cross sections in the Temkin-Poet model SO PHYSICAL REVIEW A LA English DT Article ID ELECTRON-HYDROGEN SCATTERING; ATOM IONIZATION; NEAR-THRESHOLD; SYSTEMS; IMPACT AB An integral representation of wave functions fur the Temkin-Poet model of electron impact on atomic hydrogen is given. Approximate wave functions are evaluated analytically for large hyperradius to extract the ionization S-matrix element. An ionization cross section of the form exp[-aE(-1/6)+bE(1/6)], where a and b are positive constants, is derived. The exponential suppression of ionization for small E appears to be the quantum counterpart of the delayed onset of ionization in the classical theory for this model. C1 OAK RIDGE NATL LAB,OAK RIDGE,TN 37831. UNIV LONDON ROYAL HOLLOWAY & BEDFORD NEW COLL,DEPT MATH,EGHAM TW20 0EX,SURREY,ENGLAND. RP Macek, JH (reprint author), UNIV TENNESSEE,DEPT PHYS & ASTRON,KNOXVILLE,TN 37996, USA. NR 39 TC 19 Z9 19 U1 0 U2 0 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 MAR PY 1997 VL 55 IS 3 BP 2024 EP 2035 DI 10.1103/PhysRevA.55.2024 PG 12 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA WN174 UT WOS:A1997WN17400062 ER PT J AU Chung, YS Djuric, N Wallbank, B Dunn, GH Bannister, ME Smith, ACH AF Chung, YS Djuric, N Wallbank, B Dunn, GH Bannister, ME Smith, ACH TI Resonance interference and absolute cross sections in near-threshold electron-impact excitation of the 3s(2) S-1->3s3p P-3 and 3s(2) S-1->3s3p P-1 transitions in Ar6+ SO PHYSICAL REVIEW A LA English DT Article ID ION EXCITATION; IONIZATION; SI-2+; BEAMS; KR6+ AB Strong resonance features were observed in the near-threshold excitation of Ar6+. Absolute total cross sections for electron-impact excitation of the 3s(2) S-1-->3s3p P-3(o) and 3s(2) S-1-->3s3p P-1(o) transitions in Ar6+ were measured by using the merged electron-ion beams energy loss technique. The results are compared with the R-matrix close-coupling theory (CCR) and the independent-process isolated-resonance distorted-wave approximation. Observed disagreement between CCR theory and experiment at the near-threshold peak for the 3s(2) S-1-->3s3p P-3(o) transition is interpreted to be due to very sensitive resonance interference. C1 UNIV COLORADO,BOULDER,CO 80309. OAK RIDGE NATL LAB,DIV PHYS,OAK RIDGE,TN 37831. UNIV LONDON UNIV COLL,LONDON WC1E 6BT,ENGLAND. ST FRANCIS XAVIER UNIV,DEPT PHYS,ANTIGONISH,NS B2G 2W5,CANADA. RP Chung, YS (reprint author), NIST,JILA,BOULDER,CO 80309, USA. NR 24 TC 26 Z9 26 U1 0 U2 0 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 MAR PY 1997 VL 55 IS 3 BP 2044 EP 2049 DI 10.1103/PhysRevA.55.2044 PG 6 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA WN174 UT WOS:A1997WN17400064 ER PT J AU Carpenter, MP Dunford, RW Gemmell, DS Graber, T Janssens, RVF Kanter, EP Nolen, JA Vager, Z AF Carpenter, MP Dunford, RW Gemmell, DS Graber, T Janssens, RVF Kanter, EP Nolen, JA Vager, Z TI Coulomb explosion of 173-MeV HeH+ ions traversing carbon foils SO PHYSICAL REVIEW A LA English DT Article ID MOLECULAR-IONS; ENERGY-LOSS; SOLIDS; DISSOCIATION; CLUSTERS; STATES; BEAMS AB The Coulomb explosion of 173-MeV HeH+ molecular ions traversing thin carbon foils has been measured for foil thicknesses ranging from 2 to 200 mu g/cm(2). In contrast with measurements al lower Energies, the energy spectra for protons observed emerging in the incident beam direction show distinct components that correspond to the partner helium ions being in charge states 0, 1, and 2. From an analysis of the variation of the yields of these components as functions of the target thickness, we extract electron-loss cross sections that are in good agreement with theoretical estimates. "Wake effects" that increase with increasing target thickness ate observed as asymmetries in the yields and energy shifts for "backward-going" as compared to "forward-going" protons. C1 WEIZMANN INST SCI, IL-76100 REHOVOT, ISRAEL. RP ARGONNE NATL LAB, DIV PHYS, ARGONNE, IL 60439 USA. RI Carpenter, Michael/E-4287-2015 OI Carpenter, Michael/0000-0002-3237-5734 NR 26 TC 6 Z9 6 U1 0 U2 4 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 2469-9926 EI 2469-9934 J9 PHYS REV A JI Phys. Rev. A PD MAR PY 1997 VL 55 IS 3 BP 2090 EP 2096 DI 10.1103/PhysRevA.55.2090 PG 7 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA WN174 UT WOS:A1997WN17400070 ER PT J AU Hagg, L Reinhold, CO Burgdorfer, J AF Hagg, L Reinhold, CO Burgdorfer, J TI Above-surface neutralization of slow highly charged ions in front of ionic crystals SO PHYSICAL REVIEW A LA English DT Article ID MULTICHARGED IONS; IMAGE ACCELERATION; ELECTRON-EMISSION; LITHIUM-FLUORIDE; CROSS-SECTIONS; COLLISIONS; ATOMS; LIF; SOLIDS; MODEL AB We present a theoretical analysis of the above-surface neutralization of highly charged ions in front of LiF. The study is based on the assumption that the dominant electron transfer occurs in the classically allowed region. Estimates of critical distances and corresponding quantum numbers for capture from an ionic crystal within the classical-overbarrier (COB) model are presented, which differ considerably from corresponding results for metals. The role of the dielectric response of LiF is investigated. In addition, classical-trajectory simulations are performed for a slow highly charged ion approaching an insulator. It is shown that capture effectively begins similar to 3 a.u, closer to the surface than estimated from the COB model. This correction can be incorporated into a modified COB model. The energy gain for grazing incidence ions is obtained using a staircase model which includes the deceleration due to charge-up of the surface. C1 UNIV TENNESSEE,DEPT PHYS & ASTRON,KNOXVILLE,TN 37996. OAK RIDGE NATL LAB,OAK RIDGE,TN 37831. RP Hagg, L (reprint author), UNIV STOCKHOLM,FRESCATIV 24,S-10405 STOCKHOLM,SWEDEN. OI Reinhold, Carlos/0000-0003-0100-4962 NR 36 TC 75 Z9 75 U1 0 U2 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 MAR PY 1997 VL 55 IS 3 BP 2097 EP 2108 DI 10.1103/PhysRevA.55.2097 PG 12 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA WN174 UT WOS:A1997WN17400071 ER PT J AU Cerjan, C Lee, E Farrelly, D Uzer, T AF Cerjan, C Lee, E Farrelly, D Uzer, T TI Coherent states in a Rydberg atom: Quantum mechanics SO PHYSICAL REVIEW A LA English DT Article ID POLARIZED MICROWAVE FIELD; LAGRANGE EQUILIBRIUM POINTS; NONSPREADING WAVE-PACKETS; CLASSICAL-LIMIT; HYDROGEN-ATOM; CELESTIAL MECHANICS; MAGNETIC-FIELD; IONIZATION; ELECTRONS; DYNAMICS AB We present the quantal dynamics of electronic wave packets in the hydrogen atom in the presence of circularly polarized microwave and magnetic fields in regions of classical stability. Whereas ave packets may disperse without the stabilizing influence of a magnetic field, in its presence stable motion can be maintained for wave packets that are localized either at global equilibria that are either a maximum or minimum in a zero-velocity surface. Because these extrema are locally harmonic their vacuum states are truly coherent states in the original sense of Schrodinger. C1 UTAH STATE UNIV,DEPT CHEM & BIOCHEM,LOGAN,UT 84322. GEORGIA INST TECHNOL,SCH PHYS,ATLANTA,GA 30332. RP Cerjan, C (reprint author), LAWRENCE LIVERMORE NATL LAB,POB 808 M-S L-395,LIVERMORE,CA 94550, USA. NR 64 TC 21 Z9 21 U1 0 U2 0 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 MAR PY 1997 VL 55 IS 3 BP 2222 EP 2231 DI 10.1103/PhysRevA.55.2222 PG 10 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA WN174 UT WOS:A1997WN17400085 ER PT J AU Cote, M Cohen, ML AF Cote, M Cohen, ML TI Carbon nitride compounds with 1:1 stoichiometry SO PHYSICAL REVIEW B LA English DT Article ID VAPOR-DEPOSITION; SOLIDS; FILMS; PHASE AB We have examined various structures of carbon nitride with 1:1 stoichiometry and determined that for this stoichiometry sp(2) bonding of nitrogen is energetically preferable to sp(3). We found the zinc-blende and rocksalt phases to be mechanically unstable. They relax to a rhombohedral phase composed of buckled carbon nitride sheets with interplanar covalent bonds. The rhombohedral phase has a bulk modulus of 253 GPa. Two other structures made essentially of sp(2) bonds were studied, the H-6 and bct-4 and they have bulk moduli of 345 and 375 GPa, respectively. We also calculate the structure based of the high-pressure phase of GeP and find it to be unfavorable due to its low binding energy. Using the general valence rule, we can state the requirements of a semiconducting or an insulating structure for this compound. Inspired by existing structures, we calculated the phases based on the beta-InS and GaSe compounds. Both these structures contain C-C bonds. We find that the beta-InS phase has a bulk modulus of 78 GPA. The GaSe structure is made of layers where the C-C bond is perpendicular to the plane of the layers. It is the most energetically favorable of all phases considered and it has a bulk modulus of 199 GPa. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV SCI MAT,BERKELEY,CA 94720. RP Cote, M (reprint author), UNIV CALIF BERKELEY,DEPT PHYS,BERKELEY,CA 94720, USA. RI Cote, Michel/H-3942-2012 OI Cote, Michel/0000-0001-9046-9491 NR 28 TC 68 Z9 69 U1 4 U2 12 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 MAR 1 PY 1997 VL 55 IS 9 BP 5684 EP 5688 DI 10.1103/PhysRevB.55.5684 PG 5 WC Physics, Condensed Matter SC Physics GA WN218 UT WOS:A1997WN21800041 ER PT J AU Berman, GP Campbell, DK Tsifrinovich, VI AF Berman, GP Campbell, DK Tsifrinovich, VI TI Error correction for a spin quantum computer SO PHYSICAL REVIEW B LA English DT Article ID SYSTEMS; COMPUTATION; UNIVERSAL; DYNAMICS; LOGIC AB The problems of error correction in a spin quantum computer are discussed. For digital processing in the Ising and Heisenberg chains driven by a resonant electromagnetic field, the simple schemes are suggested which provide correction of errors caused by imperfect pi pulses, and prevent the most significant errors caused by the nonresonant action of rr pulses. The probability of error caused by the Heisenberg interaction during the action of rr pulses is estimated. For quantum computations in spin systems a principal opportunity to correct the phase errors, based on Steane's three quantum-bits scheme, is described. C1 LOS ALAMOS NATL LAB,CTR NONLINEAR STUDIES,LOS ALAMOS,NM 87545. LV KIRENSKII INST PHYS,KRASNOYARSK 660036,RUSSIA. UNIV ILLINOIS,DEPT PHYS,URBANA,IL 61801. POLYTECH INST NEW YORK,DEPT APPL MATH & PHYS,BROOKLYN,NY 11201. RP Berman, GP (reprint author), LOS ALAMOS NATL LAB,DIV THEORET,LOS ALAMOS,NM 87545, USA. NR 26 TC 12 Z9 12 U1 0 U2 0 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 MAR 1 PY 1997 VL 55 IS 9 BP 5929 EP 5936 DI 10.1103/PhysRevB.55.5929 PG 8 WC Physics, Condensed Matter SC Physics GA WN218 UT WOS:A1997WN21800073 ER PT J AU Clements, BE Krotscheck, E Saarela, M AF Clements, BE Krotscheck, E Saarela, M TI Impurity dynamics in boson quantum films SO PHYSICAL REVIEW B LA English DT Article ID HE-3-HE-4 MIXTURE FILMS; HE-3 IMPURITIES; MAGNETIC-SUSCEPTIBILITY; BINDING-ENERGY; EFFECTIVE MASS; HELIUM FILMS; BOUND-STATES; SURFACE; LIQUID-HE-4; STABILITY AB We calculate the binding energy and dynamic properties of He-3 atoms in films of He-4 absorbed to graphite and several alkali metal substrates. Without adjustable parameters, we obtain excellent agreement with the experimental binding energies for the ground state of the He-3 impurity. We then introduce a time-dependent variational wave function to calculate dynamic properties of the impurity. The motion of the impurity atom parallel to the surface is characterized by an effective mass due to hydrodynamic backflow. We also obtain the spectrum of excitation energies and the lifetime of the excited states. When both lifetime and backflow effects are included, the energy of the first excited state of the impurity and the effective mass of the ground state, agree well with experimental data. C1 LOS ALAMOS NATL LAB,DIV THEORET,LOS ALAMOS,NM 87545. JOHANNES KEPLER UNIV,INST THEORET PHYS,A-4040 LINZ,AUSTRIA. UNIV OULU,DEPT PHYS SCI THEORET PHYS,SF-90570 OULU,FINLAND. RP Clements, BE (reprint author), TEXAS A&M UNIV,DEPT PHYS,COLLEGE STN,TX 77843, USA. NR 45 TC 41 Z9 41 U1 1 U2 2 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 MAR 1 PY 1997 VL 55 IS 9 BP 5959 EP 5982 DI 10.1103/PhysRevB.55.5959 PG 24 WC Physics, Condensed Matter SC Physics GA WN218 UT WOS:A1997WN21800077 ER PT J AU Cereceda, N Noheda, B Iglesias, T FernandezdelCastillo, JR Gonzalo, JA Duan, N Wang, YL Cox, DE Shirane, G AF Cereceda, N Noheda, B Iglesias, T FernandezdelCastillo, JR Gonzalo, JA Duan, N Wang, YL Cox, DE Shirane, G TI O-3 tilt and the Pb/(Zr/Ti) displacement order parameters in Zr-rich PbZr1-xTi(x)O(3) from 20 to 500 K SO PHYSICAL REVIEW B LA English DT Article ID LEAD-ZIRCONATE-TITANATE; OXYGEN OCTAHEDRON TILTS; PEROVSKITE FERROELECTRICS; TRANSITIONS AB Neutron diffraction and dielectric data have been collected from a polycrystalline sample of PbZr1-xTixO3 (x=0.035) to determine the temperature dependence of the two-order parameters associated with the oxygen octahedral tilt and the Pbl(Zr/Ti) displacement, respectively, through the sequence of phase transitions F-RL-F-RH-P-C present in this mixed system. The weak coupling between tilt and polarization (displacements) is satisfactorily described within the framework of a two-order-parameters statistical theory in which the respective effective fields involve two higher-order terms in addition to a linear term. C1 ACAD SINICA,SHANGHAI INST CERAM,SHANGHAI 200050,PEOPLES R CHINA. BROOKHAVEN NATL LAB,DEPT PHYS,UPTON,NY 11973. RP Cereceda, N (reprint author), UNIV AUTONOMA MADRID,E-28049 MADRID,SPAIN. OI Fernandez del Castillo Diez, Jose Raul/0000-0003-4335-2586 NR 16 TC 30 Z9 30 U1 2 U2 10 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 MAR 1 PY 1997 VL 55 IS 10 BP 6174 EP 6179 DI 10.1103/PhysRevB.55.6174 PG 6 WC Physics, Condensed Matter SC Physics GA WP345 UT WOS:A1997WP34500018 ER PT J AU Shimakawa, Y Kubo, Y Manako, T Sushko, YV Argyriou, DN Jorgensen, JD AF Shimakawa, Y Kubo, Y Manako, T Sushko, YV Argyriou, DN Jorgensen, JD TI Structural and magnetotransport properties of the colossal magnetoresistance material Tl2Mn2O7 SO PHYSICAL REVIEW B LA English DT Article ID DOUBLE-EXCHANGE; LA1-XSRXMNO3; FILMS; RESISTIVITY; PYROCHLORES; Y2MN2O7 AB The crystal structure and its variation with temperature of the spin-charge coupled material Tl2Mn2O7 pyrochlore is investigated. Structure refinement from the neutron powder-diffraction data reveals that Tl2Mn2O7 has nearly stoichiometric composition and is crystallized in the cubic-pyrochlore-type structure with a characteristic Mn-O-Mn bond angle of 133 degrees. There is no structural anomaly associated with the change in magnetotransport properties at 142 K, suggesting weak spin-lattice and charge-lattice correlations. Despite the similarity of magnetotransport properties observed in the perovskite and the pyrochlore colossal magnetoresistance manganese oxides, the double-exchange mechanism, which is usually applied to the perovskite materials, does not seem to explain the behavior in the pyrochlore Tl2Mn2O7 compound. A superexchange-type interaction may stabilize the ferromagnetic ordering of Mn spins and cause the metallic conduction at low temperatures in Tl2Mn2O7. C1 ARGONNE NATL LAB,DIV MAT SCI,ARGONNE,IL 60439. RP Shimakawa, Y (reprint author), NEC CORP LTD,FUNDAMENTAL RES LABS,34 MIYUKIGAOKA,TSUKUBA,IBARAKI 305,JAPAN. RI KUBO, Yoshimi/H-2851-2011 NR 28 TC 50 Z9 50 U1 0 U2 3 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 MAR 1 PY 1997 VL 55 IS 10 BP 6399 EP 6404 DI 10.1103/PhysRevB.55.6399 PG 6 WC Physics, Condensed Matter SC Physics GA WP345 UT WOS:A1997WP34500048 ER PT J AU Krimmel, A Loidl, A Schober, H Canfield, PC AF Krimmel, A Loidl, A Schober, H Canfield, PC TI Single-crystal neutron diffraction studies on CeCu2Ge2 and CeCu1.9Ni0.1Ge2 SO PHYSICAL REVIEW B LA English DT Article ID SYSTEMS; HEAT AB We have performed single-crystal neutron diffraction studies on CeCu2Ge2 and CeCu1.9Ni0.1Ge2 to get insight into the very unusual magnetic properties of these compounds. CeCu2Ge2 orders antiferromagnetically below T-N=4.15 K in an incommensurate sinusoidal amplitude modulated structure. CeCu1.9Ni0.1Ge2 shows two successive magnetic phase transitions at T-N1=3.65 K and T-N2=2.65 K, respectively. The corresponding magnetic structures are very similar to each other as well as to the magnetic structure of pure CeCu2Ge2. Based on the temperature dependence of the intensities of the principal magnetic reflections, the two magnetic phases seem to superimpose independently of each other. C1 HAHN MEITNER INST BERLIN GMBH,D-14109 BERLIN,GERMANY. INST MAX VON LAUE PAUL LANGEVIN,F-38042 GRENOBLE,FRANCE. IOWA STATE UNIV,AMES LAB,AMES,IA 50011. RP Krimmel, A (reprint author), TH DARMSTADT,INST FESTKORPERPHYS,D-64289 DARMSTADT,GERMANY. RI Canfield, Paul/H-2698-2014; Loidl, Alois/L-8199-2015 OI Loidl, Alois/0000-0002-5579-0746 NR 23 TC 29 Z9 29 U1 1 U2 6 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 MAR 1 PY 1997 VL 55 IS 10 BP 6416 EP 6420 DI 10.1103/PhysRevB.55.6416 PG 5 WC Physics, Condensed Matter SC Physics GA WP345 UT WOS:A1997WP34500051 ER PT J AU Lynn, JW Skanthakumar, S Huang, Q Sinha, SK Hossain, Z Gupta, LC Nagarajan, R Godart, C AF Lynn, JW Skanthakumar, S Huang, Q Sinha, SK Hossain, Z Gupta, LC Nagarajan, R Godart, C TI Magnetic order and crystal structure in the superconducting RNi(2)B(2)C materials SO PHYSICAL REVIEW B LA English DT Article ID NICKEL BORIDE CARBIDES; ANTIFERROMAGNETIC ORDER; NEUTRON-DIFFRACTION; B-C; HONI2B2C; DYNI2B2C; LUNI2B2C; DEPENDENCE; LNNI2B2C; ERNI2B2C AB Neutron-diffraction measurements have been carried out to investigate the crystal structure, magnetic structures, and magnetic phase transitions in RNi(2)B(2)C (R = Y, Ce, Pr, Nd, Tb, Dy, Ho, Er, Tm, and Yb). The materials that order magnetically exhibit a wide variety of both commensurate and incommensurate magnetic structures, which argues strongly that the dominant exchange interactions are of the indirect Ruderman-Kittel-Kasuya-Yosida type. The Nd system exhibits a commensurate antiferromagnetic ordering at 4.8 K, with wave vector delta=(1/2,0,1/2) and moment direction along a (or equivalently with delta=(0,1/2,1/2) and moment direction along b in this tetragonal system). For Dy (T-N=10.6 K), Pr (T-N=4.0 K), and the low-temperature phase of Ho, the magnetic structure is also a commensurate antiferromagnet that consists of ferromagnetic sheets of rare-earth moments in the a-b plane, with the sheets coupled antiferromagnetically along the c axis [delta=(0,0,1)]. Pr is not superconducting, while for Dy (T-c=6 K) and Ho (T-c=8 K) this magnetic order coexists with superconductivity. For Ho, though, the magnetic state that initially forms at T-N approximate to 8.5 K is an incommensurate spiral antiferromagnetic state along the c axis in which the direction of these ferromagnetic sheets are rotated in the a-b plane by similar to 17 degrees from their low-temperature antiparallel configuration [delta=(0,0,0.91)]. The intensity for this spiral state reaches a maximum near the reentrant superconducting transition (similar to 5 K); the spiral state then collapses at lower temperature in favor of the commensurate antiferromagnetic state. An incommensurate a-axis modulation, with delta=(0.55,0,0), is also observed above the spiral-antiferromagnetic transition, but it exists over a narrower temperature range than the spiral state, and also collapses near the reentrant superconducting transition. The Er system forms an incommensurate, transversely polarized spin-density wave (SDW) state at T-N=6.8 K, with delta=(0.553,0,0) and moment direction along b (or with delta along b and the moment direction along a). The SDW squares up at low T, and coexists with the superconducting state (T-c=11 K) over the full temperature range where magnetic order is present. Tb, which does not superconduct, orders with a very similar wave vector, but the SDW is longitudinally polarized in this case and again squares up at low T. Tm orders at T-N=1.5 K in a transversely polarized SDW state, but with the moments along the c axis and delta=(0.093,0.093,0), This state is coexistent with superconductivity (T-c=11 K). No significant magnetic moment is found to develop on the Ni site in any of the materials, and there is no magnetic ordering of any kind in the Y, Yb, or Ce materials. Profile refinements have also been carried out on these same samples to investigate the systematics of the crystallography, and the crystal structure is I4/mmm over the full range of compositions and temperatures investigated. The area of the a-b plane and the volume of the unit cell both decrease smoothly with either decreasing lanthanide radius or decreasing temperature, but the strong boron-carbon and nickel-carbon bonding then forces the c axis to expand. C1 UNIV MARYLAND,CTR SUPERCOND RES,COLLEGE PK,MD 20742. UNIV MARYLAND,MAT ENGN PROGRAM,COLLEGE PK,MD 20742. ARGONNE NATL LAB,ADV PHOTON SOURCE,ARGONNE,IL 60439. TATA INST FUNDAMENTAL RES,BOMBAY 400005,MAHARASHTRA,INDIA. CNRS,UPR 209,F-92195 MEUDON,FRANCE. RP Lynn, JW (reprint author), NIST,DIV REACTOR RADIAT,GAITHERSBURG,MD 20899, USA. NR 66 TC 266 Z9 268 U1 1 U2 22 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 MAR 1 PY 1997 VL 55 IS 10 BP 6584 EP 6598 DI 10.1103/PhysRevB.55.6584 PG 15 WC Physics, Condensed Matter SC Physics GA WP345 UT WOS:A1997WP34500069 ER PT J AU Pe, T Benkraouda, M Clem, JR AF Pe, T Benkraouda, M Clem, JR TI Magnetic coupling of two-dimensional pancake vortex lattices in a finite stack of thin superconducting films with transport currents in the two outermost layers SO PHYSICAL REVIEW B LA English DT Article ID HIGH-TC SUPERCONDUCTORS; YBA2CU3O7-X/PRBA2CU3O7-X SUPERLATTICES; YBA2CU3O7/PRBA2CU3O7 SUPERLATTICES; 2-DIMENSIONAL VORTICES; II SUPERCONDUCTORS; MIXED-STATE; BI2SR2CACU2OX; FLUCTUATIONS; TRANSFORMER; MOTION AB We give a detailed study of the magnetic coupling between two-dimensional (2D) pancake vortices in a stack of N Josephson-decoupled superconducting thin films. The problem of a single pancake vortex in a finite stack of layers is first considered. We then investigate the magnetic interaction between 2D pancake lattices residing in different layers. It is assumed that all these 2D lattices have the same structure and orientation, although it is not required that they be in perfect registry. We derive an analytical solution for the coupling force on a pancake in a lattice arising from its interaction with a vortex lattice in another layer. As a direct application of this solution, we consider the case wherein a magnetic field is applied perpendicular to the layers and equal but oppositely directed surface current densities are introduced into the top and bottom layers, respectively. Far weak currents, force-balanced configurations of pancake vortices are obtained. We then show the existence of a decoupling surface current density. Above this critical value, slippage occurs between 2D pancake lattices in different layers. This decoupling surface current density is then calculated for different magnetic fields and for different values of N. C1 IOWA STATE UNIV SCI & TECHNOL,DEPT PHYS & ASTRON,AMES,IA 50011. RP Pe, T (reprint author), IOWA STATE UNIV SCI & TECHNOL,US DOE,AMES LAB,AMES,IA 50011, USA. NR 35 TC 12 Z9 12 U1 1 U2 3 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 MAR 1 PY 1997 VL 55 IS 10 BP 6636 EP 6643 DI 10.1103/PhysRevB.55.6636 PG 8 WC Physics, Condensed Matter SC Physics GA WP345 UT WOS:A1997WP34500076 ER PT J AU Abrikosov, AA AF Abrikosov, AA TI Size of the BCS ratio in strongly underdoped high-T-c cuprates SO PHYSICAL REVIEW B LA English DT Article ID DIMENSIONAL COULOMB GAS; CRYSTALS AB An explanation is proposed of the huge (over 20) BCS ratio 2 Delta(0)/T-c discovered recently in strongly underdoped Bi2Sr2CaCu2O8-B delta. Since no marked shrinking of the Fermi surface was found; our explanation is based on the idea of disruption of the connection between CuO2 bilayers due to reduction of localized centers providing resonant tunneling between the layers. An increase of phase fluctuations of the order parameter, mostly due to spontaneous vortex formation, leads to a possibility of a drastic reduction of T-c, which practically coincides with T-BKT, the temperature of the Berezinsky-Kosterlitz-Thouless transition. At the same time, the local energy gap is likely to undergo no major changes. An argument is given why at not too small concentrations of the localized centers the critical temperature can remain rather stable, despite strong variations in the normal c-axis conductivity. RP Abrikosov, AA (reprint author), ARGONNE NATL LAB,DIV MAT SCI,9700 S CASS AVE,ARGONNE,IL 60439, USA. NR 15 TC 14 Z9 14 U1 1 U2 1 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 MAR 1 PY 1997 VL 55 IS 10 BP R6149 EP R6151 PG 3 WC Physics, Condensed Matter SC Physics GA WP345 UT WOS:A1997WP34500014 ER PT J AU Maiti, A Brabec, CJ Bernholc, J AF Maiti, A Brabec, CJ Bernholc, J TI Kinetics of metal-catalyzed growth of single-walled carbon nanotubes SO PHYSICAL REVIEW B LA English DT Article ID LARGE-SCALE SYNTHESIS; FULLERENES; PARTICLES AB Molecular-dynamics and total-energy calculations using a realistic three-body potential for carbon reveal the basic atomic processes by which single-shelled nanotubes can grow out of metal-carbide particles by the root growth mechanism. We find that nanometer-sized protrusions on the metal-particle surface lead to the nucleation of very narrow tubes. Wide bumps lead to a strained graphene sheet and no nanotube growth. The results also explain the absence of multishelled tubes in metal-catalyzed growth. C1 N CAROLINA STATE UNIV,DEPT PHYS,RALEIGH,NC 27695. RP Maiti, A (reprint author), OAK RIDGE NATL LAB,DIV SOLID STATE,POB 2008,OAK RIDGE,TN 37831, USA. NR 25 TC 145 Z9 146 U1 1 U2 18 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 MAR 1 PY 1997 VL 55 IS 10 BP R6097 EP R6100 PG 4 WC Physics, Condensed Matter SC Physics GA WP345 UT WOS:A1997WP34500001 ER PT J AU Tranquada, JM Wochner, P Moodenbaugh, AR Buttrey, DJ AF Tranquada, JM Wochner, P Moodenbaugh, AR Buttrey, DJ TI Field-induced staggered magnetic order in La2NiO4.133 SO PHYSICAL REVIEW B LA English DT Article ID 2-DIMENSIONAL HUBBARD-MODEL; T-J MODEL; HARTREE-FOCK; HOLES; CHARGE; SPINS; PHASES AB At low temperature the holes doped into the NiO2 planes of La2NiO4.133 by the excess oxygen collect in diagonal stripes that separate narrow antiferromagnetic domains. The magnetic order drops abruptly to zero at T-m=110.5 K, but charge order remains with a period of 3/2a. We show that application of a magnetic field in the regime T>T-m induces staggered magnetic order of period 3a due to the net magnetic moment of the high-temperature bond-centered stripes, together with the odd number of Ni spins across an antiferromagnetic domain. C1 UNIV DELAWARE,DEPT CHEM ENGN,NEWARK,DE 19716. RP Tranquada, JM (reprint author), BROOKHAVEN NATL LAB,DEPT PHYS,UPTON,NY 11973, USA. RI Tranquada, John/A-9832-2009; OI Tranquada, John/0000-0003-4984-8857; Moodenbaugh, Arnold/0000-0002-3415-6762 NR 36 TC 51 Z9 51 U1 0 U2 1 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 MAR 1 PY 1997 VL 55 IS 10 BP R6113 EP R6116 PG 4 WC Physics, Condensed Matter SC Physics GA WP345 UT WOS:A1997WP34500005 ER PT J AU Pasyuk, EA Alexakhin, VY Gogolev, SI Oganesyan, KO Morris, CL ODonnell, JM RawoolSullivan, MW Jones, MK Guber, FF Reshetin, AI Strakovsky, II AF Pasyuk, EA Alexakhin, VY Gogolev, SI Oganesyan, KO Morris, CL ODonnell, JM RawoolSullivan, MW Jones, MK Guber, FF Reshetin, AI Strakovsky, II TI pi(+)+d->p+p reaction between 18 and 44 MeV SO PHYSICAL REVIEW C LA English DT Article ID PION ABSORPTION; CROSS-SECTION; AMPLITUDES; ENERGIES; PROTONS; LI-6; PI+ AB A study of the reaction pi(+) + d --> p + p has been performed in the energy range of 18-44 MeV. Total cross sections and differential cross sections at six angles have been measured at 15 energies with an energy increment of 1-2 MeV. This is the most systematic data set in this energy range. No structure in the energy dependence of the cross section has been observed within the accuracy of this experiment. C1 LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545. RUTGERS STATE UNIV,PISCATAWAY,NJ 08855. INST NUCL RES,TROITSK 117312,MOSCOW REGION,RUSSIA. ST PETERSBURG NUCL PHYS INST,GATCHINA 188350,ST PETERSBURG,RUSSIA. RP Pasyuk, EA (reprint author), JOINT INST NUCL RES,DUBNA 141980,MOSCOW REGION,RUSSIA. RI Guber, Fedor/I-4271-2013 OI Guber, Fedor/0000-0001-8790-3218 NR 20 TC 16 Z9 16 U1 0 U2 0 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 MAR PY 1997 VL 55 IS 3 BP 1026 EP 1032 DI 10.1103/PhysRevC.55.1026 PG 7 WC Physics, Nuclear SC Physics GA WP325 UT WOS:A1997WP32500011 ER PT J AU Hackman, G Mullins, SM Haslip, D Flibotte, S Kuehner, JA Waddington, JC Clark, RM Pilotte, S AF Hackman, G Mullins, SM Haslip, D Flibotte, S Kuehner, JA Waddington, JC Clark, RM Pilotte, S TI Neutron excitations and interactions above the N=80 superdeformed closed shell: Superdeformation in Eu-144 SO PHYSICAL REVIEW C LA English DT Article ID COLLECTIVITY; BAND; NUCLEI; REGION; GD-146 AB Three superdeformed bands have been observed in the nucleus Eu-144 With the GAMMASPHERE spectrometer in its early implementation phase. The reaction used was Sn-122(Al-27,5n)Eu-144 at a beam energy of 142 MeV. All three bands are identified as single-neutron excitations with respect to Eu-143. One band is a confirmation of a previously suggested candidate. It is assigned as the yrast sequence based on the pi 6(1) nu 7(1) configuration, and is believed to undergo an interaction with the nu[514]9/2(-) orbital. The other two bands are assigned as signature partners based on the pi 6(1) nu (6) over tilde(1) configuration, where (6) over tilde corresponds to a mixed [651]1/2(+)/[642]5/2(+) state. The partner that contains the alpha = -1/2 signature component of the (6) over tilde orbital is identified from a band crossing that occurs in related bands in Gd-145 and Gd-146. Alignment plots suggest that the interaction strength becomes stronger as the mass number increases. C1 MCMASTER UNIV, DEPT PHYS & ASTRON, HAMILTON, ON L8S 4M1, CANADA. LAWRENCE BERKELEY LAB, BERKELEY, CA 94550 USA. UNIV OTTAWA, DEPT PHYS, OTTAWA, ON K1N 6N5, CANADA. NR 26 TC 7 Z9 7 U1 0 U2 0 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 2469-9985 EI 2469-9993 J9 PHYS REV C JI Phys. Rev. C PD MAR PY 1997 VL 55 IS 3 BP 1101 EP 1107 DI 10.1103/PhysRevC.55.1101 PG 7 WC Physics, Nuclear SC Physics GA WP325 UT WOS:A1997WP32500020 ER PT J AU Johnson, TD Aprahamian, A Lister, CJ Blumenthal, DJ Crowell, B Chowdhury, P Fallon, P Machiavelli, AO AF Johnson, TD Aprahamian, A Lister, CJ Blumenthal, DJ Crowell, B Chowdhury, P Fallon, P Machiavelli, AO TI New high spin states and band termination in Y-83 and Zr-84 SO PHYSICAL REVIEW C LA English DT Article ID SUPERDEFORMED BAND; TRANSITION STRENGTHS; IDENTIFICATION; QUASIPARTICLE; ROTATION; MOMENTS; REGION; NUCLEI; RB-81; RATES AB The gamma decay of high spin yrast states in Y-83 up to I-pi = 59/2(+) and 53/2(-) have been observed using the reaction Ni-58(Si-29,3p) at 110 MeV and the Gammasphere Early Implementation Array. The level scheme has been substantially extended due to the observations of several new transitions in all of the bands. A sequence of transitions feeding into the positive parity yrast band above I-pi = 47/2(+) seems to be consistent with a noncollective oblate structure expected at these high spins. A similar cascade is found in the data for Zr-84. A new forking of the favored negative parity band is found which may be due to neutron alignment polarizing the core to a different shape. This suggests that the ''isomeric'' band in Y-83, for which one more connecting transition was found, is of a similar nature to other high-K bands found in this region. Lifetime measurements in the unfavored negative parity band are consistent with cranking calculations which predict a nearly oblate shape with a deformation parameter beta(2) approximate to 0.2. A qualitative analysis of line shapes at very high spins suggests the persistence of collectivity in the yrast sequence to the highest excitations seen. C1 ARGONNE NATL LAB,ARGONNE,IL 60439. UNIV MASSACHUSETTS,LOWELL,MA 01854. LAWRENCE BERKELEY LAB,BERKELEY,CA 94720. RP Johnson, TD (reprint author), UNIV NOTRE DAME,NOTRE DAME,IN 46556, USA. NR 32 TC 12 Z9 12 U1 1 U2 1 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 MAR PY 1997 VL 55 IS 3 BP 1108 EP 1118 DI 10.1103/PhysRevC.55.1108 PG 11 WC Physics, Nuclear SC Physics GA WP325 UT WOS:A1997WP32500021 ER PT J AU TerAkopian, GM Hamilton, JH Oganessian, YT Daniel, AV Kormicki, J Ramayya, AV Popeko, GS Babu, BRS Lu, QH ButlerMoore, K Ma, WC Jones, EF Deng, JK Shi, D Kliman, J Morhac, M Cole, JD Aryaeinejad, R Johnson, NR Lee, IY McGowan, FK AF TerAkopian, GM Hamilton, JH Oganessian, YT Daniel, AV Kormicki, J Ramayya, AV Popeko, GS Babu, BRS Lu, QH ButlerMoore, K Ma, WC Jones, EF Deng, JK Shi, D Kliman, J Morhac, M Cole, JD Aryaeinejad, R Johnson, NR Lee, IY McGowan, FK TI Yields of correlated fragment pairs in spontaneous fission of Cf-252 SO PHYSICAL REVIEW C LA English DT Article ID NEUTRON MULTIPLICITIES; OCTUPOLE DEFORMATION; ASYMMETRIC FISSION; NUCLEAR-FISSION; SPIN STATES; ISOTOPES; HEAVY; SCISSION; CHARGE; MASS AB Independent yields of 139 individual secondary (appearing after neutron evaporation) fragment pairs of five different charge splits (Z(L)/Z(H) = 46/52, 44/54, 42/56, 40/58, and 38/60) have been experimentally measured by detecting the coincidences between prompt gamma rays emitted in the spontaneous fission of Cf-252. Nuclear charge and mass distributions of fission fragments that follow from the measured yields of individual fragment pairs are consistent with similar previously known more integral data. Another type of data extracted from the yields of fragment pairs is the multiplicity distributions of prompt neutrons emitted in the five above charge divisions of Cf-252. For the measured charge splits, about 70% of the fission events where greater than or equal to 7 neutrons are evaporated from the fission fragments occur for the Mo-Ba split of Cf-252. Mass and excitation energy distributions of primary Ru-Xe, Mo-Pa, and Zr-Ce fragments were deduced from a least squares fit to the yield pattern of secondary fragment pairs. For the Ru-Xe and Zr-Ce splits, the experimental data are well fitted by assuming one fission mode with average total kinetic energy (TKE) values close to the value of (TKE) known for the Cf-252 spontaneous fission. For the Mo-Pa split, a successful fit could be obtained only with the assumption that, in addition to this ''normal'' fission mode, a second mode with a remarkably lower value of (TKE) of 153 MeV contributes to this charge split. This is 36 MeV lower than for the normal mode. These data indicate that in mode two the barium nuclei are hyperdeformed (3:1 axis ratio) at scission. Mean angular momentum values of Mo-Ba fission fragments observed in pairs together with various partners have been deduced from the measured populations of different spin levels of the fragment nuclei. These angular momentum values are discussed in terms of their dependence on the primary fragment excitation energy and presence of two fission modes. C1 VANDERBILT UNIV, DEPT PHYS, NASHVILLE, TN 37235 USA. MISSISSIPPI STATE UNIV, DEPT PHYS, MISSISSIPPI STATE, MS 39762 USA. SLOVAK ACAD SCI, INST PHYS, BRATISLAVA, SLOVAKIA. IDAHO NATL ENGN LAB, IDAHO FALLS, ID 83415 USA. OAK RIDGE NATL LAB, DIV PHYS, OAK RIDGE, TN 37831 USA. ORISE, UNIRIB, OAK RIDGE, TN 37832 USA. RP JOINT INST NUCL RES, DUBNA 141980, RUSSIA. NR 81 TC 66 Z9 69 U1 0 U2 3 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 2469-9985 EI 2469-9993 J9 PHYS REV C JI Phys. Rev. C PD MAR PY 1997 VL 55 IS 3 BP 1146 EP 1161 DI 10.1103/PhysRevC.55.1146 PG 16 WC Physics, Nuclear SC Physics GA WP325 UT WOS:A1997WP32500026 ER PT J AU Wauters, J Batchelder, JC Bingham, CR Blumenthal, DJ Brown, LT Conticchio, LF Davids, CN Davinson, T Irvine, RJ Seweryniak, D Toth, KS Walters, WB Woods, PJ Zganjr, EF AF Wauters, J Batchelder, JC Bingham, CR Blumenthal, DJ Brown, LT Conticchio, LF Davids, CN Davinson, T Irvine, RJ Seweryniak, D Toth, KS Walters, WB Woods, PJ Zganjr, EF TI Fine structure in the alpha decay of Bi-189 SO PHYSICAL REVIEW C LA English DT Article ID INTRUDER STATES; BI ISOTOPES; NUCLEI; COEXISTENCE; POLONIUM; DETECTOR; SHELL; TL AB A detailed alpha-decay study was performed for Bi-189m,Bi-g produced in the reaction of Mo-95 on Mo-96 at 418 MeV. Evaporation residues were selected in-flight using the Argonne fragment mass analyzer and implanted into a double sided silicon strip detector. The correlation technique between implants and subsequent decays was used to observe new weak alpha branches of Bi-189 to excited states in Tl-185. A more precise value of 182(8) keV for the excitation energy of the pi s(1/2) intruder state in Bi-189 was determined. The alpha decay of the Bi-189(9/2(-)) ground state to the pi d(3/2) level at 284 keV was observed for the first time. In addition, the alpha decay of Bi-188 was remeasured. Reduced widths for the alpha decays of odd-A Bi-189-197m,Bi-g nuclei to states in their Tl daughters are discussed. C1 LOUISIANA STATE UNIV,BATON ROUGE,LA 70803. OAK RIDGE NATL LAB,OAK RIDGE,TN 37831. ARGONNE NATL LAB,ARGONNE,IL 60439. VANDERBILT UNIV,NASHVILLE,TN 37235. UNIV MARYLAND,COLLEGE PK,MD 20742. UNIV EDINBURGH,EDINBURGH EH9 3JZ,MIDLOTHIAN,SCOTLAND. RP Wauters, J (reprint author), UNIV TENNESSEE,KNOXVILLE,TN 37996, USA. NR 19 TC 18 Z9 18 U1 0 U2 0 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 MAR PY 1997 VL 55 IS 3 BP 1192 EP 1196 DI 10.1103/PhysRevC.55.1192 PG 5 WC Physics, Nuclear SC Physics GA WP325 UT WOS:A1997WP32500030 ER PT J AU Magierski, P Burzynski, K Perlinska, E Dobaczewski, J Nazarewicz, W AF Magierski, P Burzynski, K Perlinska, E Dobaczewski, J Nazarewicz, W TI Quadrupole and hexadecapole correlations in rotating nuclei studied within the single-j shell model SO PHYSICAL REVIEW C LA English DT Article ID SUPERDEFORMED BANDS; DELTA-I=4 BIFURCATION; C-4 SYMMETRY; SCATTERING; HG-194 AB The influence of quadrupole and hexadecapole residual interactions on rotational bands is investigated in a single-j shell model. An exact shell-model diagonalization of the quadrupole-plus-hexadecapole Hamiltonian demonstrates that the hexadecapole-hexadecapole interaction can sometimes produce a staggering of energy levels in the yrast sequence; however, long and regular Delta I=2 sequences are not obtained. The shell-model results are discussed in terms of the intrinsic deformations extracted by means of the self-consistent Hartree-Fock method. The angular momentum dependence of intrinsic quadrupole and hexadecapole moments Q(2 mu) and Q(4 mu) is investigated. C1 UNIV WARSAW,INST THEORET PHYS,PL-00681 WARSAW,POLAND. UNIV TENNESSEE,DEPT PHYS & ASTRON,KNOXVILLE,TN 37996. OAK RIDGE NATL LAB,DIV PHYS,OAK RIDGE,TN 37831. RP Magierski, P (reprint author), WARSAW UNIV TECHNOL,INST PHYS,KOSZYKOWA 75,PL-00662 WARSAW,POLAND. NR 44 TC 10 Z9 10 U1 0 U2 1 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 MAR PY 1997 VL 55 IS 3 BP 1236 EP 1245 DI 10.1103/PhysRevC.55.1236 PG 10 WC Physics, Nuclear SC Physics GA WP325 UT WOS:A1997WP32500037 ER PT J AU Ofenloch, BG Giannelli, RA Ritchie, BG ODonnell, JM Knudson, JN Morris, CL Kormanyos, CM Saunders, A Williams, JZ Lindgren, RA Clausen, BL AF Ofenloch, BG Giannelli, RA Ritchie, BG ODonnell, JM Knudson, JN Morris, CL Kormanyos, CM Saunders, A Williams, JZ Lindgren, RA Clausen, BL TI Pion-nucleus spin-flip strength at low and resonance energies SO PHYSICAL REVIEW C LA English DT Article ID SUPERCONDUCTING RADIOFREQUENCY CAVITY; PARTICLE-HOLE STATES; INELASTIC-SCATTERING; ELECTRON-SCATTERING; ELASTIC-SCATTERING; STRETCHED STATES; B-10; BEAMS; LAMPF; C-14 AB Cross sections have been measured for 65 MeV pi(+) scattering to the B-10 ground and first four excited states. The 1.74 MeV excited state results provide the first measurement of the energy dependence of the isovector spin-flip strength parameter. Our analysis indicates that the observed empirical enhancement of the isovector spin-flip strength has little or no dependence on energy at and below resonance. A mass dependence for the empirical enhancement factor may exist. C1 ARIZONA STATE UNIV,TEMPE,AZ 85287. LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545. UNIV COLORADO,NUCL PHYS LAB,BOULDER,CO 80309. UNIV VIRGINIA,CHARLOTTESVILLE,VA 22904. LOMA LINDA UNIV,GEOSCI RES INST,LOMA LINDA,CA 92350. LA SIERRA UNIV,DEPT PHYS,RIVERSIDE,CA 92515. OI Clausen, Benjamin Leroy/0000-0001-9894-7830 NR 34 TC 0 Z9 0 U1 0 U2 0 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 MAR PY 1997 VL 55 IS 3 BP 1295 EP 1303 DI 10.1103/PhysRevC.55.1295 PG 9 WC Physics, Nuclear SC Physics GA WP325 UT WOS:A1997WP32500046 ER PT J AU Friedman, E Gal, A Weiss, R Aclander, J Alster, J Mardor, I Mardor, Y Beck, SM Piasetzky, E Yavin, AI Bart, S Chrien, RE Pile, PH Sawafta, R Sutter, RJ Barakat, M Johnston, K Krauss, RA Seyfarth, H Stearns, RL AF Friedman, E Gal, A Weiss, R Aclander, J Alster, J Mardor, I Mardor, Y Beck, SM Piasetzky, E Yavin, AI Bart, S Chrien, RE Pile, PH Sawafta, R Sutter, RJ Barakat, M Johnston, K Krauss, RA Seyfarth, H Stearns, RL TI K+ nucleus reaction and total cross sections: New analysis of transmission experiments SO PHYSICAL REVIEW C LA English DT Article ID ELASTIC-SCATTERING; KAONIC ATOMS; PION CLOUD; DEPENDENCE; POTENTIALS; EXCHANGE AB The attenuation cross sections measured in transmission experiments at the alternating-gradient synchrotron for K+ on Li-6, C, Si and Ca at p(L) = 488, 531, 656, and 714 MeV/c are reanalyzed in order to derive total (sigma(T)) and reaction (sigma(R)) cross sections. The effect of plural (Moliere) scattering is properly accounted for, leading to revised values of sigma(T). We demonstrate the model dependence of these values, primarily due to the choice of K+ nuclear optical potential used to generate the necessary Coulomb-nuclear and nuclear elastic corrections. Values of sigma(R) are also derived, for the first time, from the same data and exhibit a remarkable degree of model independence. The derived values of sigma(T) and sigma(R) exceed those calculated by the first-order t rho optical potential for C, Si, and Ca, but not for Li-6, particularly at 656 and 714 MeV/c where the excess is 10-25%. Relative to Li-6, this excess is found to be nearly energy independent and its magnitude of 15-25% is not reproduced by any nuclear medium effect studied so far. C1 TEL AVIV UNIV, RAYMOND & BEVERLY SACKLER FAC EXACT SCI, SCH PHYS, IL-69978 TEL AVIV, ISRAEL. BROOKHAVEN NATL LAB, DEPT PHYS, UPTON, NY 11973 USA. LOUISIANA TECH UNIV, DEPT PHYS, RUSTON, LA 71272 USA. TEXAS A&M UNIV, COLLEGE STN, TX 77843 USA. FORSCHUNGSZENTRUM JULICH, D-52425 JULICH, GERMANY. VASSAR COLL, POUGHKEEPSIE, NY 12601 USA. RP HEBREW UNIV JERUSALEM, RACAH INST PHYS, IL-91904 JERUSALEM, ISRAEL. NR 38 TC 35 Z9 35 U1 0 U2 2 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 2469-9985 EI 2469-9993 J9 PHYS REV C JI Phys. Rev. C PD MAR PY 1997 VL 55 IS 3 BP 1304 EP 1311 DI 10.1103/PhysRevC.55.1304 PG 8 WC Physics, Nuclear SC Physics GA WP325 UT WOS:A1997WP32500047 ER PT J AU Barette, J Bellwied, R Bennett, S BraunMunzinger, P Chang, WC Cleland, WE Clemen, M Cole, J Cormier, TM David, G Dee, J Dietzsch, O Drigert, M Hall, JR Hemmick, TK Herrmann, N Hong, B Kwon, Y Lacasse, R Lukaszew, A Li, Q Ludlam, TW Mark, SK Matheus, R McCorkle, S Murgatroyd, JT OBrien, E Panitkin, S Piazza, T Pruneau, C Rao, MN Rosati, M daSilva, NC Sedykh, S Sonnadara, U Stachel, J Takagui, EM Voloshin, S Wang, G Wessels, JP Woody, CL Xu, N Zhang, Y Zou, C AF Barette, J Bellwied, R Bennett, S BraunMunzinger, P Chang, WC Cleland, WE Clemen, M Cole, J Cormier, TM David, G Dee, J Dietzsch, O Drigert, M Hall, JR Hemmick, TK Herrmann, N Hong, B Kwon, Y Lacasse, R Lukaszew, A Li, Q Ludlam, TW Mark, SK Matheus, R McCorkle, S Murgatroyd, JT OBrien, E Panitkin, S Piazza, T Pruneau, C Rao, MN Rosati, M daSilva, NC Sedykh, S Sonnadara, U Stachel, J Takagui, EM Voloshin, S Wang, G Wessels, JP Woody, CL Xu, N Zhang, Y Zou, C TI Energy and charged particle flow in 10.8A GeV/c Au+Au collisions SO PHYSICAL REVIEW C LA English DT Article ID HEAVY-ION COLLISIONS; TRANSVERSE FLOW; FRAGMENT FLOW; AU; CALORIMETER; MATTER AB Experimental results and a detailed analysis are presented of the transverse energy and charged particle azimuthal distributions measured by the E877 Collaboration for different centralities of Au+Au collisions at a beam momentum of 10.8A GeV/c. The anisotropy of these distributions is studied with respect to the reaction plane reconstructed on an event-by-event basis using the transverse energy distribution measured by calorimeters. Results are corrected for the reaction plane resolution. For semicentral events we observe directed flow signals of up to 10%. We observe a stronger anisotropy for slow charged particles. For both the charged particle and transverse energy distributions we observe a small but nonzero elliptic anisotropy with the major axis pointing into the reaction plane. Combining the information on transverse energy and charged particle flow we obtain information on the flow of nucleons and pions. The data are compared to event generators and the need to introduce a mean field or nucleon-nucleon potential is discussed. C1 GESELL SCHWERIONENFORSCH MBH,D-6100 DARMSTADT,GERMANY. IDAHO NATL ENGN LAB,IDAHO FALLS,ID 83402. MCGILL UNIV,MONTREAL,PQ,CANADA. UNIV PITTSBURGH,PITTSBURGH,PA 15260. SUNY STONY BROOK,STONY BROOK,NY 11794. UNIV SAO PAULO,SAO PAULO,BRAZIL. WAYNE STATE UNIV,DETROIT,MI 48202. RP Barette, J (reprint author), BROOKHAVEN NATL LAB,UPTON,NY 11973, USA. RI Sonnadara, Upul/E-6359-2010; Voloshin, Sergei/I-4122-2013; OI Sonnadara, Upul/0000-0001-7862-2537 NR 34 TC 20 Z9 20 U1 0 U2 1 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 MAR PY 1997 VL 55 IS 3 BP 1420 EP 1430 PG 11 WC Physics, Nuclear SC Physics GA WP325 UT WOS:A1997WP32500060 ER PT J AU Mattiello, R Sorge, H Stocker, H Greiner, W AF Mattiello, R Sorge, H Stocker, H Greiner, W TI Nuclear clusters as a probe for expansion flow in heavy ion reactions at (10-15)A GeV SO PHYSICAL REVIEW C LA English DT Review ID QUANTUM MOLECULAR-DYNAMICS; BOSE-EINSTEIN CORRELATIONS; AU+AU COLLISIONS; HADRONIC MATTER; TRANSVERSE FLOW; COALESCENCE MODEL; COLLECTIVE FLOW; LIGHT FRAGMENTS; ENERGY-LEVELS; DEUTERON AB A phase space coalescence description based on the Wigner-function method for cluster formation in relativistic nucleus-nucleus collisions is presented. The momentum distributions of nuclear clusters d, t, and He are predicted for central Au(11.6A GeV)Au and Si(14.6A GeV)Si reactions in the framework of the relativistic quantum molecular dynamics transport approach. Transverse expansion leads to a strong shoulder-arm shape and different inverse slope parameters in the transverse spectra of nuclear clusters deviating markedly from thermal distributions. A clear ''bounce-of'' event shape is seen: The averaged transverse how velocities in the reaction plane are for clusters larger than for protons. The cluster yields, particularly at low p(t) at midrapidities, and the in-plane (anti)flow of clusters and pions change if suitably strong baryon potential interactions are included. This allows one to study the transient pressure at high density via the event shape analysis of nucleons, nucleon clusters, and other hadrons. C1 SUNY STONY BROOK, DEPT PHYS, STONY BROOK, NY 11974 USA. UNIV FRANKFURT, INST THEORET PHYS, D-60054 FRANKFURT, GERMANY. RP BROOKHAVEN NATL LAB, DEPT PHYS, UPTON, NY 11973 USA. RI Stoecker, Horst/D-6173-2013 OI Stoecker, Horst/0000-0002-3282-3664 NR 101 TC 67 Z9 67 U1 0 U2 4 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 2469-9985 EI 2469-9993 J9 PHYS REV C JI Phys. Rev. C PD MAR PY 1997 VL 55 IS 3 BP 1443 EP 1454 DI 10.1103/PhysRevC.55.1443 PG 12 WC Physics, Nuclear SC Physics GA WP325 UT WOS:A1997WP32500062 ER PT J AU Taddeucci, TN Ullmann, J Rybarcyk, LJ Butler, GW Ward, TE AF Taddeucci, TN Ullmann, J Rybarcyk, LJ Butler, GW Ward, TE TI Total cross sections for production of Be-7, Na-22, and Na-24 in p+Li-7 and p+Al-27 reactions at 495 and 795 MeV SO PHYSICAL REVIEW C LA English DT Article ID HIGH-ENERGY PROTONS; FRAGMENTS; MG AB Activation techniques have been used to measure the total cross section for the production of Be-7, Na-22, and Na-24 in proton induced reactions on Li-7 and Al-27 targets at bombarding energies of 495 MeV and 795 MeV. The cross section for the Li-7(p,n)Be-7(g.s.+0.43-MeV) reaction at 795 MeV is about 11-15 % larger than extrapolations based on previous data below 480 MeV. C1 US DOE,WASHINGTON,DC 20585. RP Taddeucci, TN (reprint author), LOS ALAMOS NATL LAB,POB 1663,LOS ALAMOS,NM 87545, USA. NR 19 TC 8 Z9 8 U1 0 U2 1 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 MAR PY 1997 VL 55 IS 3 BP 1551 EP 1554 DI 10.1103/PhysRevC.55.1551 PG 4 WC Physics, Nuclear SC Physics GA WP325 UT WOS:A1997WP32500075 ER PT J AU Lane, GJ Fossan, DB Thorslund, I Paul, ES Simpson, J Blumenthal, DJ Davids, CN Lister, CJ Seweryniak, D AF Lane, GJ Fossan, DB Thorslund, I Paul, ES Simpson, J Blumenthal, DJ Davids, CN Lister, CJ Seweryniak, D TI Identification of excited states in Te-111 SO PHYSICAL REVIEW C LA English DT Article ID FRAGMENT MASS ANALYZER; ROTATIONAL BANDS; SPECTROSCOPY; REGION AB Excited states have been identified in Te-111 using the Fe-56(Ni-58,2pn) reaction at 240 MeV. Assignment of transitions to Te-111 was made via measurements of gamma rays in coincidence with both evaporation neutrons and mass-analyzed recoils. The observed cascade of gamma rays is assumed to feed an isomeric state with J(pi)=11/2(-), similar to the yrast structures observed in other odd-mass tellurium isotopes. C1 UNIV LIVERPOOL,OLIVER LODGE LAB,LIVERPOOL L69 3BX,MERSEYSIDE,ENGLAND. DARESBURY LAB,CCLRC,WARRINGTON WA4 4AD,CHESHIRE,ENGLAND. ARGONNE NATL LAB,ARGONNE,IL 60439. UNIV MARYLAND,COLLEGE PK,MD 20742. RP Lane, GJ (reprint author), SUNY STONY BROOK,DEPT PHYS,STONY BROOK,NY 11794, USA. RI Lane, Gregory/A-7570-2011 OI Lane, Gregory/0000-0003-2244-182X NR 20 TC 6 Z9 6 U1 0 U2 0 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 MAR PY 1997 VL 55 IS 3 BP 1559 EP 1562 DI 10.1103/PhysRevC.55.1559 PG 4 WC Physics, Nuclear SC Physics GA WP325 UT WOS:A1997WP32500077 ER PT J AU Fallon, P Stephens, FS Asztalos, S Busse, B Clark, RM Deleplanque, MA Diamond, RM Krucken, R Lee, IY Macchiavelli, AO MacLeod, RW Schmid, G Vetter, K Nakatsukasa, T AF Fallon, P Stephens, FS Asztalos, S Busse, B Clark, RM Deleplanque, MA Diamond, RM Krucken, R Lee, IY Macchiavelli, AO MacLeod, RW Schmid, G Vetter, K Nakatsukasa, T TI Octupole vibrations and signature splitting in even mass Hg superdeformed bands SO PHYSICAL REVIEW C LA English DT Article ID EXCITATIONS; HG-192; SPINS AB The octupole characteristics of excited SD bands in Hg-190,Hg-192,Hg-194 are discussed. In particular we show that for Hg-194, the odd spin sequence is favored at lower spins-in agreement with the assumption these bands-contain significant octupole character. The data are compared with a model in which K=2 octupole vibrations are predicted to be favored at the low frequencies. C1 UNIV MANCHESTER,INST SCI & TECHNOL,DEPT PHYS,MANCHESTER M60 1QD,LANCS,ENGLAND. RP Fallon, P (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV NUCL SCI,1 CYCLOTRON RD,BERKELEY,CA 94720, USA. RI Nakatsukasa, Takashi/O-9995-2014; Kruecken, Reiner/A-1640-2013 OI Kruecken, Reiner/0000-0002-2755-8042 NR 18 TC 18 Z9 18 U1 0 U2 1 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 MAR PY 1997 VL 55 IS 3 BP R999 EP R1001 DI 10.1103/PhysRevC.55.R999 PG 3 WC Physics, Nuclear SC Physics GA WP325 UT WOS:A1997WP32500004 ER PT J AU Hartley, DJ Pfohl, J Riley, MA Sarantites, DG Devlin, M LaFosse, DR Archer, DE Brown, TB Clark, RM Fallon, P Hibbert, IM Joss, DT Nolan, PJ OBrien, N Paul, ES Sheline, RK Simpson, J Wadsworth, R AF Hartley, DJ Pfohl, J Riley, MA Sarantites, DG Devlin, M LaFosse, DR Archer, DE Brown, TB Clark, RM Fallon, P Hibbert, IM Joss, DT Nolan, PJ OBrien, N Paul, ES Sheline, RK Simpson, J Wadsworth, R TI Proton orbital effects in the second minimum of doubly odd Pr-132 SO PHYSICAL REVIEW C LA English DT Article ID EXCITED SUPERDEFORMED BANDS; HIGHLY DEFORMED BANDS; NUCLEUS; REGION; TRANSITIONS; DEFORMATION; ND-133; DECAY AB Second minimum structures have been observed for the first time in the doubly odd nucleus Pr-132(59). Two new bands are interpreted as based on the pi g(9/2)[404]9/2x nu i(13/2)[660]1/2 configuration and a third as the pi h(11/2)[532]5/2x nu i(13/2)[660]1/2 configuration. Signature splitting effects observed in the pi(g(9/2))(-1) bands provide new information regarding the positive parity proton orbitals at large deformation. Results from the extracted B(M1)/B(E2) ratios are consistent with a large deformation for the pi(g(9/2))(-1) bands. C1 WASHINGTON UNIV,DEPT CHEM,ST LOUIS,MO 63130. UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV NUCL SCI,BERKELEY,CA 94720. UNIV YORK,DEPT PHYS,YORK YO1 5DD,N YORKSHIRE,ENGLAND. UNIV LIVERPOOL,OLIVER LODGE LAB,LIVERPOOL L69 3BX,MERSEYSIDE,ENGLAND. CCLRC,DARESBURY LAB,WARRINGTON WA4 4AD,CHESHIRE,ENGLAND. RP Hartley, DJ (reprint author), FLORIDA STATE UNIV,DEPT PHYS,TALLAHASSEE,FL 32306, USA. RI Devlin, Matthew/B-5089-2013 OI Devlin, Matthew/0000-0002-6948-2154 NR 34 TC 12 Z9 12 U1 0 U2 0 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 MAR PY 1997 VL 55 IS 3 BP R985 EP R989 DI 10.1103/PhysRevC.55.R985 PG 5 WC Physics, Nuclear SC Physics GA WP325 UT WOS:A1997WP32500001 ER PT J AU Zamfir, NV Cottle, PD Casten, RF Deylitz, S Gollwitzer, A Graw, G Hertenberger, R Valnion, B CataDanil, G Zhang, JY Chou, WT AF Zamfir, NV Cottle, PD Casten, RF Deylitz, S Gollwitzer, A Graw, G Hertenberger, R Valnion, B CataDanil, G Zhang, JY Chou, WT TI Octupole fragmentation and the structure of Ba-134 SO PHYSICAL REVIEW C LA English DT Article ID INTERACTING BOSON MODEL; STATES; NUCLEI AB The low energy octupole states in Ba-134 were examined using the inelastic scattering of 22 MeV protons. Strong fragmentation of the low energy octupole strength, which was observed in Pt-196,Pt-198 and was identified as a signature of the O(6) dynamical symmetry limit of the interacting boson approximation (IBA), does not occur in Ba-134, which has been proposed to have O(6) structure. The model calculations demonstrate that there is, in fact, little difference in the structure of the low-lying positive parity levels between certain nuclei in a U(5)-->SU(3) (vibrator-->rotor) transition and an O(6) nucleus (gamma-soft nucleus), but that the octupole fragmentation has an enhanced sensitivity to the d-boson composition of the wave functions and thereby reveals differences in structure that are not easily discernible with other observables. C1 BROOKHAVEN NATL LAB,UPTON,NY 11973. CLARK UNIV,WORCESTER,MA 01610. INST ATOM PHYS,R-76900 BUCHAREST,ROMANIA. FLORIDA STATE UNIV,TALLAHASSEE,FL 32306. UNIV MUNICH,SEKT PHYS,D-85748 GARCHING,GERMANY. UNIV TENNESSEE,KNOXVILLE,TN 37996. NATL TSING HUA UNIV,HSINCHU,TAIWAN. RP Zamfir, NV (reprint author), YALE UNIV,AW WRIGHT NUCL STRUCT LAB,NEW HAVEN,CT 06520, USA. RI Zamfir, Nicolae Victor/F-2544-2011 NR 16 TC 11 Z9 11 U1 0 U2 0 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 MAR PY 1997 VL 55 IS 3 BP R1007 EP R1010 PG 4 WC Physics, Nuclear SC Physics GA WP325 UT WOS:A1997WP32500006 ER PT J AU Abe, K Abe, K Abt, I Akagi, T Allen, NJ Ash, WW Aston, D Baird, KG Baltay, C Band, HR Barakat, MB Baranko, G Bardon, O Barklow, T Bashindzhagyan, GL Bazarko, AO BenDavid, R Benvenuti, AC Bilei, GM Bisello, D Blaylock, G Bogart, JR Bolton, T Bower, GR Brau, JE Breidenbach, M Bugg, WM Burke, D Burnett, TH Burrows, PN Busza, W Calcaterra, A Caldwell, DO Calloway, D Camanzi, B Carpinelli, M Cassell, R Castaldi, R Castro, A CavalliSforza, M Chou, A Church, E Cohn, HO Coller, JA Cook, V Cotton, R Cowan, RF Coyne, DG Crawford, G DOliveira, A Damerell, CJS Daoudi, M DeSangro, R DeSimone, P DellOrso, R Dervan, PJ Dima, M Dong, DN Du, PYC Dubois, R Eisenstein, BI Elia, R Etzion, E Falciai, D Fan, C Fero, MJ Frey, R Furuno, K Gillman, T Gladding, G Gonzalez, S Hallewell, GD Hart, EL Hasan, A Hasegawa, Y Hasuko, K Hedges, S Hertzbach, SS Hildreth, MD Huber, J Huffer, ME Hughes, EW Hwang, H Iwasaki, Y Jackson, DJ Jacques, P Jaros, J Johnson, AS Johnson, JR Johnson, RA Junk, T Kajikawa, R Kalelkar, M Kang, HJ Karliner, I Kawahara, H Kendall, HW Kim, Y King, ME King, R Kofler, RR Krishna, NM Kroeger, RS Labs, JF Langston, M Lath, A Lauber, JA Leith, DWGS Lia, V Liu, MX Liu, X Loreti, M Lu, A Lynch, HL Ma, J Mancinelli, G Manly, S Mantovani, G Markiewicz, TW Maruyama, T Massetti, R Masuda, H Mazzucato, E McKemey, AK Meadows, BT Messner, R Mockett, PM Moffeit, KC Mours, B Muller, D Nagamine, T Narita, S Nauenberg, U Neal, H Nussbaum, M Ohnishi, Y Osborne, LS Panvini, RS Park, H Pavel, TJ Peruzzi, I Piccolo, M Piemontese, L Pieroni, E Pitts, KT Plano, RJ Prepost, R Prescott, CY Punkar, GD Quigley, J Ratcliff, BN Reeves, TW Reidy, J Rensing, PE Rizzo, TG Rochester, LS Rowson, PC Russell, JJ Saxton, OH Schalk, T Schindler, RH Schumm, BA Sen, S Serbo, VV Shaevitz, MH Shank, JT Shapiro, G Sherden, DJ Shmakov, KD Simopoulos, C Sinev, NB Smith, SR Snyder, JA Stamer, P Steiner, H Steiner, R Strauss, MG Su, D Suekane, F Sugiyama, A Suzuki, S Swartz, M Szumilo, A Takahashi, T Taylor, FE Torrence, E Trandafir, AI Turk, JD Usher, T Vavra, J Vannini, C Vella, E Venuti, JP Verdier, R Verdini, PG Wagner, SR Waite, AP Watts, SJ Weidemann, AW Weiss, ER Whitaker, JS White, SL Wickens, FJ Williams, DA Williams, DC Williams, SH Willocq, S Wilson, RJ Wisniewski, WJ Woods, M Wold, GB Wyss, J Yamamoto, RK Yamartino, JM Yang, X Yellin, SJ Young, CC Yuta, H Zapalac, G Zdarko, RW Zeitlin, C Zhou, J AF Abe, K Abe, K Abt, I Akagi, T Allen, NJ Ash, WW Aston, D Baird, KG Baltay, C Band, HR Barakat, MB Baranko, G Bardon, O Barklow, T Bashindzhagyan, GL Bazarko, AO BenDavid, R Benvenuti, AC Bilei, GM Bisello, D Blaylock, G Bogart, JR Bolton, T Bower, GR Brau, JE Breidenbach, M Bugg, WM Burke, D Burnett, TH Burrows, PN Busza, W Calcaterra, A Caldwell, DO Calloway, D Camanzi, B Carpinelli, M Cassell, R Castaldi, R Castro, A CavalliSforza, M Chou, A Church, E Cohn, HO Coller, JA Cook, V Cotton, R Cowan, RF Coyne, DG Crawford, G DOliveira, A Damerell, CJS Daoudi, M DeSangro, R DeSimone, P DellOrso, R Dervan, PJ Dima, M Dong, DN Du, PYC Dubois, R Eisenstein, BI Elia, R Etzion, E Falciai, D Fan, C Fero, MJ Frey, R Furuno, K Gillman, T Gladding, G Gonzalez, S Hallewell, GD Hart, EL Hasan, A Hasegawa, Y Hasuko, K Hedges, S Hertzbach, SS Hildreth, MD Huber, J Huffer, ME Hughes, EW Hwang, H Iwasaki, Y Jackson, DJ Jacques, P Jaros, J Johnson, AS Johnson, JR Johnson, RA Junk, T Kajikawa, R Kalelkar, M Kang, HJ Karliner, I Kawahara, H Kendall, HW Kim, Y King, ME King, R Kofler, RR Krishna, NM Kroeger, RS Labs, JF Langston, M Lath, A Lauber, JA Leith, DWGS Lia, V Liu, MX Liu, X Loreti, M Lu, A Lynch, HL Ma, J Mancinelli, G Manly, S Mantovani, G Markiewicz, TW Maruyama, T Massetti, R Masuda, H Mazzucato, E McKemey, AK Meadows, BT Messner, R Mockett, PM Moffeit, KC Mours, B Muller, D Nagamine, T Narita, S Nauenberg, U Neal, H Nussbaum, M Ohnishi, Y Osborne, LS Panvini, RS Park, H Pavel, TJ Peruzzi, I Piccolo, M Piemontese, L Pieroni, E Pitts, KT Plano, RJ Prepost, R Prescott, CY Punkar, GD Quigley, J Ratcliff, BN Reeves, TW Reidy, J Rensing, PE Rizzo, TG Rochester, LS Rowson, PC Russell, JJ Saxton, OH Schalk, T Schindler, RH Schumm, BA Sen, S Serbo, VV Shaevitz, MH Shank, JT Shapiro, G Sherden, DJ Shmakov, KD Simopoulos, C Sinev, NB Smith, SR Snyder, JA Stamer, P Steiner, H Steiner, R Strauss, MG Su, D Suekane, F Sugiyama, A Suzuki, S Swartz, M Szumilo, A Takahashi, T Taylor, FE Torrence, E Trandafir, AI Turk, JD Usher, T Vavra, J Vannini, C Vella, E Venuti, JP Verdier, R Verdini, PG Wagner, SR Waite, AP Watts, SJ Weidemann, AW Weiss, ER Whitaker, JS White, SL Wickens, FJ Williams, DA Williams, DC Williams, SH Willocq, S Wilson, RJ Wisniewski, WJ Woods, M Wold, GB Wyss, J Yamamoto, RK Yamartino, JM Yang, X Yellin, SJ Young, CC Yuta, H Zapalac, G Zdarko, RW Zeitlin, C Zhou, J TI Study of the orientation and energy partition of three-jet events in hadronic Z(0) decays SO PHYSICAL REVIEW D LA English DT Article ID E+E-ANNIHILATION; 3-JET EVENTS; QUANTUM CHROMODYNAMICS; GLUON BREMSSTRAHLUNG; QCD MODELS; SPIN; DISTRIBUTIONS; ASYMMETRY; RESONANCE; DETECTOR AB We have measured the distributions of the jet energies in e(+)e(-) --> q(q) over barg$ events, and of the three orientation angles of the event plane. using hadronic Z(0) decays collected in the SLD experiment at SLAG. We find that the data are well described by perturbative QCD incorporating vector gluons. We have also studied models of scalar and tensor gluon production and find them to be incompatible with our data. C1 ADELPHI UNIV, GARDEN CITY, NY 11530 USA. IST NAZL FIS NUCL, I-40126 BOLOGNA, ITALY. BOSTON UNIV, BOSTON, MA 02215 USA. BRUNEL UNIV, UXBRIDGE UB8 3PH, MIDDX, ENGLAND. CALTECH, PASADENA, CA 91125 USA. UNIV CALIF SANTA BARBARA, SANTA BARBARA, CA 93106 USA. UNIV CALIF SANTA CRUZ, SANTA CLARA, CA 95064 USA. UNIV CINCINNATI, CINCINNATI, OH 45221 USA. COLORADO STATE UNIV, FT COLLINS, CO 80523 USA. UNIV COLORADO, BOULDER, CO 80309 USA. COLUMBIA UNIV, NEW YORK, NY 10027 USA. IST NAZL FIS NUCL, I-44100 FERRARA, ITALY. UNIV FERRARA, I-44100 FERRARA, ITALY. IST NAZL FIS NUCL, LAB NAZL FRASCATI, I-00044 FRASCATI, ITALY. UNIV ILLINOIS, URBANA, IL 61801 USA. UNIV CALIF BERKELEY, LAWRENCE BERKELEY LAB, BERKELEY, CA 94720 USA. MIT, CAMBRIDGE, MA 02139 USA. UNIV MASSACHUSETTS, AMHERST, MA 01003 USA. UNIV MISSISSIPPI, UNIVERSITY, MS 38677 USA. MOSCOW MV LOMONOSOV STATE UNIV, INST NUCL PHYS, MOSCOW 119899, RUSSIA. UNIV OREGON, EUGENE, OR 97403 USA. IST NAZL FIS NUCL, I-35100 PADUA, ITALY. UNIV PADUA, I-35100 PADUA, ITALY. IST NAZL FIS NUCL, I-06100 PERUGIA, ITALY. UNIV PERUGIA, I-06100 PERUGIA, ITALY. IST NAZL FIS NUCL, I-56100 PISA, ITALY. UNIV PISA, I-56100 PISA, ITALY. RUTGERS STATE UNIV, PISCATAWAY, NJ 08855 USA. RUTHERFORD APPLETON LAB, DIDCOT OX11 0QX, OXON, ENGLAND. SOGANG UNIV, SEOUL, SOUTH KOREA. STANFORD UNIV, STANFORD LINEAR ACCELERATOR CTR, STANFORD, CA 94309 USA. UNIV TENNESSEE, KNOXVILLE, TN 37996 USA. TOHOKU UNIV, SENDAI, MIYAGI 980, JAPAN. VANDERBILT UNIV, NASHVILLE, TN 37235 USA. UNIV WASHINGTON, SEATTLE, WA 98195 USA. UNIV WISCONSIN, MADISON, WI 53706 USA. YALE UNIV, NEW HAVEN, CT 06511 USA. UNIV GENOA, I-16126 GENOA, ITALY. RP Abe, K (reprint author), NAGOYA UNIV, CHIKUSA KU, NAGOYA, AICHI 464, JAPAN. RI de Sangro, Riccardo/J-2901-2012; de Simone, Patrizia/J-3549-2012; Cavalli-Sforza, Matteo/H-7102-2015; Frey, Raymond/E-2830-2016; Calcaterra, Alessandro/P-5260-2015; OI de Sangro, Riccardo/0000-0002-3808-5455; Frey, Raymond/0000-0003-0341-2636; Calcaterra, Alessandro/0000-0003-2670-4826; pieroni, enrico/0000-0002-4246-6963; Wyss, Jeffery/0000-0002-8277-4012 NR 45 TC 6 Z9 6 U1 0 U2 1 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1550-7998 J9 PHYS REV D JI Phys. Rev. D PD MAR 1 PY 1997 VL 55 IS 5 BP 2533 EP 2545 DI 10.1103/PhysRevD.55.2533 PG 13 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA WL503 UT WOS:A1997WL50300005 ER PT J AU Abe, F Akimoto, H Akopian, A Albrow, MG Amendolia, SR Amidei, D Antos, J AnwayWiese, C Aota, S Apollinari, G Asakawa, T Ashmanskas, W Atac, M Azfar, F AzziBacchetta, P Bacchetta, N Badgett, W Bagdasarov, S Bailey, MW Bao, J deBarbaro, P BarbaroGaltieri, A Barnes, VE Barnett, BA Barzi, E Bauer, G Baumann, T Bedeschi, F Behrends, S Belforte, S Belletini, G Bellinger, J Benjamin, D Benlloch, J Bensinger, J Benton, D Beretvas, A Berge, JP Berryhill, J Bertolucci, S Bevensee, B Bhatti, A Biery, K Binkley, M Bisello, D Blair, RE Blocker, C Bodek, A Bokhari, W Bolognesi, V Bolla, G Bortoletto, D Boudreau, J Breccia, L Bromberg, C Bruner, N BuckleyGeer, E Budd, HS Burkett, K Busetto, G ByonWagner, A Byrum, KL Cammerata, J Campagnari, C Campbell, M Caner, A Carithers, W Carlsmith, D Castro, A Cauz, D Cen, Y Cervelli, F Chang, PS Chang, PT Chao, HY Chapman, J Cheng, MT Chiarelli, G Chikamatsu, T Chiou, CN Christofek, L Cihangir, S Clark, AG Cobal, M Cocca, E Contreras, M Conway, J Cooper, J Cordelli, M Couyoumtzelis, C Crane, D CroninHennessy, D Culbertson, R Daniels, T DeJongh, F Delchamps, S DellAgnello, S DellOrso, M Demina, R Demortier, L Denby, B Deninno, M Derwent, PF Devlin, T Dittmann, JR Donati, S Done, J Dorigo, T Dunn, A Eddy, N Einsweiler, K Elias, JE Ely, R Engels, E Errede, D Errede, S Fan, Q Ferretti, C Fiori, I Flaugher, B Foster, GW Franklin, M Frautschi, M Freeman, J Friedman, J Fuess, TA Fukui, Y Funaki, S Gagliardi, G Galeotti, S Gallinaro, M GarciaSciveres, M Garfinkel, AF Gay, C Geer, S Gerdes, DW Giannetti, P Giokaris, N Giromini, P Giusti, G Gladney, L Glenzinski, D Gold, M Gonzalez, J Gordon, A Goshaw, AT Goulianos, K Grassmann, H Groer, L GrossoPilcher, C Guillian, G Guo, RS Haber, C Hafen, E Hahn, SR Hamilton, R Handler, R Hans, RM Hara, K Hardman, AD Harral, B Harris, RM Hauger, SA Hauser, J Hawk, C Hayashi, E Heinrich, J Hoffman, KD Hohlmann, M Holck, C Hollebeek, R Holloway, L Holscher, A Hong, S Houk, G Hu, P Huffman, BT Hughes, R Huston, J Huth, J Hylen, J Ikeda, H Incagli, M Incandela, J Introzzi, G Iwai, J Iwata, Y Jensen, H Joshi, U Kadel, RW Kajfasz, E Kambara, H Kamon, T Kaneko, T Karr, K Kasha, H Kato, Y Keaffaber, TA Keeble, L Kelley, K Kennedy, RD Kephart, R Kesten, P Kestenbaum, D Keup, RM Keutelian, H Keyvan, F Kharadia, B Kim, BJ Kim, DH Kim, HS Kim, SB Kim, SH Kim, YK Kirsch, L Koehn, P Kondo, K Konigsberg, J Kopp, S Kordas, K Korytov, A Koska, W Kovacs, E Kowald, W Krasberg, M Kroll, J Kruse, M Kuwabara, T Kuhlmann, SE Kuns, E Laasanen, AT Labanca, N Lammel, S Lamoureux, JI LeCompte, T Leone, S Lewis, JD Limon, P Lindgren, M Liss, TM Lockyer, N Long, O Loomis, C Loreti, M Lu, J Lucchesi, D Lukens, P Lusin, S Lys, J Maeshima, K Maghakian, A Maksimovic, P Mangano, M Mansour, J Mariotti, M Marriner, JP Martin, A Matthews, JAJ Mattingly, R McIntyre, P Melese, P Menzione, A Meschi, E Metzler, S Miao, C Miao, T Michail, G Miller, R Minato, H Miscetti, S Mishina, M Mitsushio, H Miyamoto, T Miyashita, S Moggi, N Morita, Y Mueller, J Mukherjee, A Muller, T Murat, P Nakada, H Nakano, I Nelson, C Neuberger, D NewmanHolmes, C Ninomiya, M Nodulman, L Oh, SH Ohl, KE Ohmoto, T Ohsugi, T Oishi, R Okabe, M Okusawa, T Oliveira, R Olsen, J Pagliarone, C Paoletti, R Papadimitriou, V Pappas, SP Park, S Parri, A Patrick, J Pauletta, G Paulini, M Perazzo, A Pescara, L Peters, MD Phillips, TJ Piacentino, G Pillai, M Pitts, KT Plunkett, R Pondrom, L Proudfoot, J Ptohos, F Punzi, G Ragan, K Ribon, A Rimondi, F Ristori, L Robertson, WJ Rodrigo, T Rolli, S Romano, J Rosenson, L Roser, R Sakumoto, WK Saltzberg, D Sansoni, A Santi, L Sato, H Schlabach, P Schmidt, EE Schmidt, MP Scribano, A Segler, S Seidel, S Seiya, Y Sganos, G Shapiro, MD Shaw, NM Shen, Q Shepard, PF Shimojima, M Shochet, M Siegrist, J Sill, A Sinervo, P Singh, P Skarha, J Sliwa, K Snider, FD Song, T Spalding, J Speer, T Sphicas, P Spinella, F Spiropulu, M Spiegel, L Stanco, L Steele, J Stefanini, A Strahl, K Strait, J Strohmer, R Stuart, D Sullivan, G Soumarokov, A Sumorok, K Suzuki, J Takada, T Takahashi, T Takano, T Takikawa, K Tamura, N Tartarelli, F Taylor, W Teng, PK Teramoto, Y Tether, S Theriot, D Thomas, TL Thun, R Timko, M Tipton, P Titov, A Tkaczyk, S Toback, D Tollefson, K Tollestrup, A deTroconiz, JF Truitt, S Tseng, J Turini, N Uchida, T Uemura, N Ukegawa, F Unal, G Valls, J vandenBrink, SC Vejcik, S Velev, G Vidal, R Vondracek, M Vucinic, D Wagner, RG Wagner, RL Wahl, J Wallace, N Wang, C Wang, CH Wang, J Wang, MJ Wang, QF Warburton, A Watts, T Webb, R Wei, C Wendt, C Wenzel, H Wester, WC Wicklund, AB Wicklund, E Wilkinson, R Williams, HH Wilson, P Winer, BL Winn, D Wolinski, D Wolinski, J Worm, S Wu, X Wyss, J Yagil, A Yao, W Yasuoka, K Ye, Y Yeh, GP Yeh, P Yin, M Yoh, J Yosef, C Yoshida, T Yovanovitch, D Yu, I Yu, L Yun, JC Zanetti, A Zetti, F Zhang, L Zhang, W Zucchelli, S AF Abe, F Akimoto, H Akopian, A Albrow, MG Amendolia, SR Amidei, D Antos, J AnwayWiese, C Aota, S Apollinari, G Asakawa, T Ashmanskas, W Atac, M Azfar, F AzziBacchetta, P Bacchetta, N Badgett, W Bagdasarov, S Bailey, MW Bao, J deBarbaro, P BarbaroGaltieri, A Barnes, VE Barnett, BA Barzi, E Bauer, G Baumann, T Bedeschi, F Behrends, S Belforte, S Belletini, G Bellinger, J Benjamin, D Benlloch, J Bensinger, J Benton, D Beretvas, A Berge, JP Berryhill, J Bertolucci, S Bevensee, B Bhatti, A Biery, K Binkley, M Bisello, D Blair, RE Blocker, C Bodek, A Bokhari, W Bolognesi, V Bolla, G Bortoletto, D Boudreau, J Breccia, L Bromberg, C Bruner, N BuckleyGeer, E Budd, HS Burkett, K Busetto, G ByonWagner, A Byrum, KL Cammerata, J Campagnari, C Campbell, M Caner, A Carithers, W Carlsmith, D Castro, A Cauz, D Cen, Y Cervelli, F Chang, PS Chang, PT Chao, HY Chapman, J Cheng, MT Chiarelli, G Chikamatsu, T Chiou, CN Christofek, L Cihangir, S Clark, AG Cobal, M Cocca, E Contreras, M Conway, J Cooper, J Cordelli, M Couyoumtzelis, C Crane, D CroninHennessy, D Culbertson, R Daniels, T DeJongh, F Delchamps, S DellAgnello, S DellOrso, M Demina, R Demortier, L Denby, B Deninno, M Derwent, PF Devlin, T Dittmann, JR Donati, S Done, J Dorigo, T Dunn, A Eddy, N Einsweiler, K Elias, JE Ely, R Engels, E Errede, D Errede, S Fan, Q Ferretti, C Fiori, I Flaugher, B Foster, GW Franklin, M Frautschi, M Freeman, J Friedman, J Fuess, TA Fukui, Y Funaki, S Gagliardi, G Galeotti, S Gallinaro, M GarciaSciveres, M Garfinkel, AF Gay, C Geer, S Gerdes, DW Giannetti, P Giokaris, N Giromini, P Giusti, G Gladney, L Glenzinski, D Gold, M Gonzalez, J Gordon, A Goshaw, AT Goulianos, K Grassmann, H Groer, L GrossoPilcher, C Guillian, G Guo, RS Haber, C Hafen, E Hahn, SR Hamilton, R Handler, R Hans, RM Hara, K Hardman, AD Harral, B Harris, RM Hauger, SA Hauser, J Hawk, C Hayashi, E Heinrich, J Hoffman, KD Hohlmann, M Holck, C Hollebeek, R Holloway, L Holscher, A Hong, S Houk, G Hu, P Huffman, BT Hughes, R Huston, J Huth, J Hylen, J Ikeda, H Incagli, M Incandela, J Introzzi, G Iwai, J Iwata, Y Jensen, H Joshi, U Kadel, RW Kajfasz, E Kambara, H Kamon, T Kaneko, T Karr, K Kasha, H Kato, Y Keaffaber, TA Keeble, L Kelley, K Kennedy, RD Kephart, R Kesten, P Kestenbaum, D Keup, RM Keutelian, H Keyvan, F Kharadia, B Kim, BJ Kim, DH Kim, HS Kim, SB Kim, SH Kim, YK Kirsch, L Koehn, P Kondo, K Konigsberg, J Kopp, S Kordas, K Korytov, A Koska, W Kovacs, E Kowald, W Krasberg, M Kroll, J Kruse, M Kuwabara, T Kuhlmann, SE Kuns, E Laasanen, AT Labanca, N Lammel, S Lamoureux, JI LeCompte, T Leone, S Lewis, JD Limon, P Lindgren, M Liss, TM Lockyer, N Long, O Loomis, C Loreti, M Lu, J Lucchesi, D Lukens, P Lusin, S Lys, J Maeshima, K Maghakian, A Maksimovic, P Mangano, M Mansour, J Mariotti, M Marriner, JP Martin, A Matthews, JAJ Mattingly, R McIntyre, P Melese, P Menzione, A Meschi, E Metzler, S Miao, C Miao, T Michail, G Miller, R Minato, H Miscetti, S Mishina, M Mitsushio, H Miyamoto, T Miyashita, S Moggi, N Morita, Y Mueller, J Mukherjee, A Muller, T Murat, P Nakada, H Nakano, I Nelson, C Neuberger, D NewmanHolmes, C Ninomiya, M Nodulman, L Oh, SH Ohl, KE Ohmoto, T Ohsugi, T Oishi, R Okabe, M Okusawa, T Oliveira, R Olsen, J Pagliarone, C Paoletti, R Papadimitriou, V Pappas, SP Park, S Parri, A Patrick, J Pauletta, G Paulini, M Perazzo, A Pescara, L Peters, MD Phillips, TJ Piacentino, G Pillai, M Pitts, KT Plunkett, R Pondrom, L Proudfoot, J Ptohos, F Punzi, G Ragan, K Ribon, A Rimondi, F Ristori, L Robertson, WJ Rodrigo, T Rolli, S Romano, J Rosenson, L Roser, R Sakumoto, WK Saltzberg, D Sansoni, A Santi, L Sato, H Schlabach, P Schmidt, EE Schmidt, MP Scribano, A Segler, S Seidel, S Seiya, Y Sganos, G Shapiro, MD Shaw, NM Shen, Q Shepard, PF Shimojima, M Shochet, M Siegrist, J Sill, A Sinervo, P Singh, P Skarha, J Sliwa, K Snider, FD Song, T Spalding, J Speer, T Sphicas, P Spinella, F Spiropulu, M Spiegel, L Stanco, L Steele, J Stefanini, A Strahl, K Strait, J Strohmer, R Stuart, D Sullivan, G Soumarokov, A Sumorok, K Suzuki, J Takada, T Takahashi, T Takano, T Takikawa, K Tamura, N Tartarelli, F Taylor, W Teng, PK Teramoto, Y Tether, S Theriot, D Thomas, TL Thun, R Timko, M Tipton, P Titov, A Tkaczyk, S Toback, D Tollefson, K Tollestrup, A deTroconiz, JF Truitt, S Tseng, J Turini, N Uchida, T Uemura, N Ukegawa, F Unal, G Valls, J vandenBrink, SC Vejcik, S Velev, G Vidal, R Vondracek, M Vucinic, D Wagner, RG Wagner, RL Wahl, J Wallace, N Wang, C Wang, CH Wang, J Wang, MJ Wang, QF Warburton, A Watts, T Webb, R Wei, C Wendt, C Wenzel, H Wester, WC Wicklund, AB Wicklund, E Wilkinson, R Williams, HH Wilson, P Winer, BL Winn, D Wolinski, D Wolinski, J Worm, S Wu, X Wyss, J Yagil, A Yao, W Yasuoka, K Ye, Y Yeh, GP Yeh, P Yin, M Yoh, J Yosef, C Yoshida, T Yovanovitch, D Yu, I Yu, L Yun, JC Zanetti, A Zetti, F Zhang, L Zhang, W Zucchelli, S TI Measurement of b(b)over-bar production correlations B-0(B)over-bar(0) mixing, and a limit on epsilon(B) in p(p)over-bar collisions at root s=1.8 TeV SO PHYSICAL REVIEW D LA English DT Article ID QUARK PRODUCTION; 1.8 TEV; COLLIDER; DECAYS; LIFETIME; DETECTOR; FERMILAB; Z(0) AB We present measurements of correlated cross sections, correlations, the average parameter <(chi)over bar>, and a limit on the CP-violating parameter epsilon(B). For these measurements, we use muon pairs from double semileptonic decays. The data used in this analysis were taken with the Collider Detector at Ferrnilab and represent an integrated luminosity of 17.4 +/- 0.6 pb(-1). The results concerning production correlations are compared to predictions of next-to-leading order QCD computations. C1 ARGONNE NATL LAB,ARGONNE,IL 60439. UNIV BOLOGNA,IST NAZL FIS NUCL,I-40126 BOLOGNA,ITALY. BRANDEIS UNIV,WALTHAM,MA 02254. UNIV CALIF LOS ANGELES,LOS ANGELES,CA 90024. UNIV CHICAGO,CHICAGO,IL 60637. FERMILAB NATL ACCELERATOR LAB,BATAVIA,IL 60510. DUKE UNIV,DURHAM,NC 27708. IST NAZL FIS NUCL,LAB NAZL FRASCATI,I-00044 FRASCATI,ITALY. UNIV GENEVA,CH-1211 GENEVA 4,SWITZERLAND. HARVARD UNIV,CAMBRIDGE,MA 02138. HIROSHIMA UNIV,HIGASHIHIROSHIMA 724,JAPAN. UNIV ILLINOIS,URBANA,IL 61801. MCGILL UNIV,INST PARTICLE PHYS,MONTREAL,PQ H3A 2T8,CANADA. UNIV TORONTO,TORONTO,ON M5S 1A7,CANADA. JOHNS HOPKINS UNIV,BALTIMORE,MD 21218. ERNEST ORLAND LAWRENCE BERKELY LAB,BERKELEY,CA 94720. MIT,CAMBRIDGE,MA 02139. UNIV MICHIGAN,ANN ARBOR,MI 48109. MICHIGAN STATE UNIV,E LANSING,MI 48824. UNIV NEW MEXICO,ALBUQUERQUE,NM 87131. OSAKA CITY UNIV,OSAKA 588,JAPAN. UNIV PADUA,IST NAZL FIS NUCL,I-35131 PADUA,ITALY. UNIV PENN,PHILADELPHIA,PA 19104. UNIV PISA,IST NAZL FIS NUCL,I-56100 PISA,ITALY. SCUOLA NORMALE SUPER PISA,I-56100 PISA,ITALY. UNIV PITTSBURGH,PITTSBURGH,PA 15260. PURDUE UNIV,W LAFAYETTE,IN 47907. UNIV ROCHESTER,ROCHESTER,NY 14627. ROCKEFELLER UNIV,NEW YORK,NY 10021. RUTGERS STATE UNIV,PISCATAWAY,NJ 08854. ACAD SINICA,TAIPEI 11529,TAIWAN. TEXAS A&M UNIV,COLLEGE STN,TX 77843. TEXAS TECH UNIV,LUBBOCK,TX 79409. UNIV TSUKUBA,TSUKUBA,IBARAKI 305,JAPAN. TUFTS UNIV,MEDFORD,MA 02155. UNIV WISCONSIN,MADISON,WI 53706. YALE UNIV,NEW HAVEN,CT 06511. RP Abe, F (reprint author), NATL LAB HIGH ENERGY PHYS,TSUKUBA,IBARAKI 305,JAPAN. RI Azzi, Patrizia/H-5404-2012; Punzi, Giovanni/J-4947-2012; Chiarelli, Giorgio/E-8953-2012; Warburton, Andreas/N-8028-2013; Kim, Soo-Bong/B-7061-2014; Paulini, Manfred/N-7794-2014; Introzzi, Gianluca/K-2497-2015; Vucinic, Dejan/C-2406-2008 OI Azzi, Patrizia/0000-0002-3129-828X; Punzi, Giovanni/0000-0002-8346-9052; Chiarelli, Giorgio/0000-0001-9851-4816; Warburton, Andreas/0000-0002-2298-7315; Paulini, Manfred/0000-0002-6714-5787; Introzzi, Gianluca/0000-0002-1314-2580; NR 37 TC 86 Z9 86 U1 0 U2 4 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2821 J9 PHYS REV D JI Phys. Rev. D PD MAR 1 PY 1997 VL 55 IS 5 BP 2546 EP 2558 DI 10.1103/PhysRevD.55.2546 PG 13 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA WL503 UT WOS:A1997WL50300006 ER PT J AU Anastassov, A Blinov, S Duboscq, JE Fisher, KD Fujino, D Fulton, R Gan, KK Hart, T Honscheid, K Kagan, H Kass, R Lee, J Spencer, MB Sung, M Undrus, A Wanke, R Wolf, A Zoeller, MM Nemati, B Richichi, SJ Ross, WR Skubic, P Wood, M Bishai, M Fast, J Gerndt, E Hinson, JW Menon, N Miller, DH Shibata, EI Shipsey, IPJ Yurko, M Gibbons, L Johnson, SD Kwon, Y Roberts, S Thorndike, EH Jessop, CP Lingel, K Marsiske, H Perl, ML Schaffner, SF Ugolini, D Wang, R Zhou, X Coan, TE Fadeyev, V Korolkov, I Maravin, Y Narsky, I Shelkov, V Staeck, J Stroynowski, R Volobouev, I Ye, J Artuso, M Efimov, A Frasconi, F Gao, M Goldberg, M He, D Kopp, S Moneti, GC Mountain, R Mukhin, Y Schuh, S Skwarnicki, T Stone, S Viehhauser, G Xing, X Bartelt, J Csorna, SE Jain, V Marka, S Freyberger, A Gibaut, D Godang, R Kinoshita, K Lai, IC Pomianowski, P Schrenk, S Bonvicini, G Cinabro, D Greene, R Perera, LP Barish, B Chadha, M Chan, S Eigen, G Miller, JS OGrady, C Schmidtler, M Urheim, J Weinstein, AJ Wurthwein, F Asner, DM Bliss, DW Brower, WS Masek, G Paar, HP Sivertz, M Sharma, V Gronberg, J Kutschke, R Lange, DJ Menary, S Morrison, RJ Nelson, HN Nelson, TK Qiao, C Richman, JD Roberts, D Ryd, A Witherell, MS Balest, R Behrens, BH Cho, K Ford, WT Park, H Rankin, P Roy, J Smith, JG Alexander, JP Bebek, C Berger, BE Berkelman, K Bloom, K Cassel, DG Cho, HA Coffman, DM Crowcroft, DS Dickson, M Drell, PS Ecklund, KM Ehrlich, R Elia, R Foland, AD Gaidarev, P Galik, RS Gittelman, B Gray, SW Hartill, DL Heltsley, BK Hopman, PI Kandaswamy, J Katayama, N Kim, PC Kreinick, DL Lee, T Liu, Y Ludwig, GS Masui, J Mevissen, J Mistry, NB Ng, CR Nordberg, E Ogg, M Patterson, JR Peterson, D Riley, D Soffer, A Ward, C Athanas, M Avery, P Jones, CD Lohner, M Prescott, C Yang, S Yelton, J Zheng, J Brandenburg, G Briere, RA Gao, YS Kim, DYJ Wilson, R Yamamoto, H Browder, TE Li, F Li, Y Rodriguez, JL Bergfeld, T Eisenstein, BI Ernst, J Gladding, GE Gollin, GD Hans, RM Johnson, E Karliner, I Marsh, MA Palmer, M Selen, M Thaler, JJ Edwards, KW Bellerive, A Janicek, R MacFarlane, DB McLean, KW Patel, PM Sadoff, AJ Ammar, R Baringer, P Bean, A Besson, D Coppage, D Darling, C Davis, R Hancock, N Kotov, S Kravchenko, I Kwak, N Anderson, S Kubota, Y Lattery, R ONeill, JJ Patton, S Poling, R Riehle, T Savinov, V Smith, A Alam, MS Athar, SB Ling, Z Mahmood, AH Severini, H Timm, S Wappler, F AF Anastassov, A Blinov, S Duboscq, JE Fisher, KD Fujino, D Fulton, R Gan, KK Hart, T Honscheid, K Kagan, H Kass, R Lee, J Spencer, MB Sung, M Undrus, A Wanke, R Wolf, A Zoeller, MM Nemati, B Richichi, SJ Ross, WR Skubic, P Wood, M Bishai, M Fast, J Gerndt, E Hinson, JW Menon, N Miller, DH Shibata, EI Shipsey, IPJ Yurko, M Gibbons, L Johnson, SD Kwon, Y Roberts, S Thorndike, EH Jessop, CP Lingel, K Marsiske, H Perl, ML Schaffner, SF Ugolini, D Wang, R Zhou, X Coan, TE Fadeyev, V Korolkov, I Maravin, Y Narsky, I Shelkov, V Staeck, J Stroynowski, R Volobouev, I Ye, J Artuso, M Efimov, A Frasconi, F Gao, M Goldberg, M He, D Kopp, S Moneti, GC Mountain, R Mukhin, Y Schuh, S Skwarnicki, T Stone, S Viehhauser, G Xing, X Bartelt, J Csorna, SE Jain, V Marka, S Freyberger, A Gibaut, D Godang, R Kinoshita, K Lai, IC Pomianowski, P Schrenk, S Bonvicini, G Cinabro, D Greene, R Perera, LP Barish, B Chadha, M Chan, S Eigen, G Miller, JS OGrady, C Schmidtler, M Urheim, J Weinstein, AJ Wurthwein, F Asner, DM Bliss, DW Brower, WS Masek, G Paar, HP Sivertz, M Sharma, V Gronberg, J Kutschke, R Lange, DJ Menary, S Morrison, RJ Nelson, HN Nelson, TK Qiao, C Richman, JD Roberts, D Ryd, A Witherell, MS Balest, R Behrens, BH Cho, K Ford, WT Park, H Rankin, P Roy, J Smith, JG Alexander, JP Bebek, C Berger, BE Berkelman, K Bloom, K Cassel, DG Cho, HA Coffman, DM Crowcroft, DS Dickson, M Drell, PS Ecklund, KM Ehrlich, R Elia, R Foland, AD Gaidarev, P Galik, RS Gittelman, B Gray, SW Hartill, DL Heltsley, BK Hopman, PI Kandaswamy, J Katayama, N Kim, PC Kreinick, DL Lee, T Liu, Y Ludwig, GS Masui, J Mevissen, J Mistry, NB Ng, CR Nordberg, E Ogg, M Patterson, JR Peterson, D Riley, D Soffer, A Ward, C Athanas, M Avery, P Jones, CD Lohner, M Prescott, C Yang, S Yelton, J Zheng, J Brandenburg, G Briere, RA Gao, YS Kim, DYJ Wilson, R Yamamoto, H Browder, TE Li, F Li, Y Rodriguez, JL Bergfeld, T Eisenstein, BI Ernst, J Gladding, GE Gollin, GD Hans, RM Johnson, E Karliner, I Marsh, MA Palmer, M Selen, M Thaler, JJ Edwards, KW Bellerive, A Janicek, R MacFarlane, DB McLean, KW Patel, PM Sadoff, AJ Ammar, R Baringer, P Bean, A Besson, D Coppage, D Darling, C Davis, R Hancock, N Kotov, S Kravchenko, I Kwak, N Anderson, S Kubota, Y Lattery, R ONeill, JJ Patton, S Poling, R Riehle, T Savinov, V Smith, A Alam, MS Athar, SB Ling, Z Mahmood, AH Severini, H Timm, S Wappler, F TI Experimental tests of lepton universality in tau decay SO PHYSICAL REVIEW D LA English DT Article ID CLEO-II DETECTOR; BHABHA SCATTERING; LOW ANGLES; RADIATIVE-CORRECTIONS; BRANCHING RATIO; QED CORRECTIONS; LIBRARY; MASS; DISTRIBUTIONS; FRACTION AB The branching fractions for tau --> e nu nu(tau), mu nu nu(tau), and h nu(tau) are measured using data collected with the CLEO detector at the CESR e(+)e(-) collider: beta(mu)=0.1776 +/- 0.0006 +/- 0.0017, beta(mu)=0.1737 +/- 0.0008 +/- 0.0018, and beta(h)=0.1152 +/- 0.0005 +/- 0.0012, where the first error is statistical, the second systematic, and h refers to either a charged pi or K. Also measured is the tau mass, m(tau)=(1778.2 +/- 1.4) MeV. Lepton universality is affirmed by the relative branching fractions (beta(mu)/beta(e)=0.9777 +/- 0.0063 +/- 0.0087, beta(h)/beta(e)=0.6484 +/- 0.0041 +/- 0.0060) and the charged-current gauge coupling-constant ratios (g(mu)/g(e)=1.0026 +/- 0.0055, g(tau)/g(mu)=0.9990 +/- 0.0098). The tau mass result may be recast as a tau neutrino mass limit, m(nu tau) < 60 MeV at 95% C.L. C1 UNIV OKLAHOMA, NORMAN, OK 73019 USA. PURDUE UNIV, W LAFAYETTE, IN 47907 USA. UNIV ROCHESTER, WILLIAM E SIMON GRAD SCH BUSINESS ADM, ROCHESTER, NY 14627 USA. STANFORD UNIV, STANFORD LINEAR ACCELERATOR CTR, STANFORD, CA 94309 USA. SO METHODIST UNIV, DALLAS, TX 75275 USA. SYRACUSE UNIV, SYRACUSE, NY 13244 USA. VANDERBILT UNIV, NASHVILLE, TN 37235 USA. VIRGINIA POLYTECH INST & STATE UNIV, BLACKSBURG, VA 24061 USA. WAYNE STATE UNIV, DETROIT, MI 48202 USA. CALTECH, PASADENA, CA 91125 USA. UNIV CALIF SAN DIEGO, LA JOLLA, CA 92093 USA. UNIV CALIF SANTA BARBARA, SANTA BARBARA, CA 93106 USA. UNIV COLORADO, BOULDER, CO 80309 USA. CORNELL UNIV, ITHACA, NY 14853 USA. UNIV FLORIDA, GAINESVILLE, FL 32611 USA. HARVARD UNIV, CAMBRIDGE, MA 02138 USA. UNIV HAWAII MANOA, HONOLULU, HI 96822 USA. CARLETON UNIV, OTTAWA, ON K1S 5B6, CANADA. UNIV ILLINOIS, URBANA, IL 61801 USA. ITHACA COLL, ITHACA, NY 14850 USA. UNIV KANSAS, LAWRENCE, KS 66045 USA. UNIV MINNESOTA, MINNEAPOLIS, MN 55455 USA. SUNY ALBANY, ALBANY, NY 12222 USA. BINP, RU-630090 NOVOSIBIRSK, RUSSIA. LAWRENCE LIVERMORE NATL LAB, LIVERMORE, CA 94551 USA. UNIV TEXAS, AUSTIN, TX 78712 USA. RP OHIO STATE UNIV, COLUMBUS, OH 43210 USA. RI Schaffner, Stephen/D-1189-2011; Briere, Roy/N-7819-2014; Frasconi, Franco/K-1068-2016 OI Briere, Roy/0000-0001-5229-1039; Frasconi, Franco/0000-0003-4204-6587 NR 37 TC 30 Z9 30 U1 1 U2 2 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 2470-0010 EI 2470-0029 J9 PHYS REV D JI Phys. Rev. D PD MAR 1 PY 1997 VL 55 IS 5 BP 2559 EP 2576 DI 10.1103/PhysRevD.55.2559 PG 18 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA WL503 UT WOS:A1997WL50300007 ER PT J AU Brodsky, SJ Hebecker, A Quack, E AF Brodsky, SJ Hebecker, A Quack, E TI Drell-Yan process and factorization in impact parameter space SO PHYSICAL REVIEW D LA English DT Article ID ANGULAR-DISTRIBUTIONS; SCATTERING; COLLISIONS; PAIRS AB The cross section for Drell-Yan pair production in the limit of small x(target) is derived in the rest frame of the target hadron. Our calculation is based on the fundamental quantity sigma(rho), the cross section for the scattering of a pair with fixed transverse separation rho off a hadronic target. As in deep inelastic scattering the result can be given in terms of integrals of sigma(rho). This is consistent with well-known factorization theorems and also relates higher-twist terms in both processes. An analysis of the angular distribution of the produced lepton shows that additional integrals of sigma(rho) can be obtained in the Drell-Yan process, which are not measurable in inclusive deep inelastic scattering. RP Brodsky, SJ (reprint author), STANFORD UNIV,STANFORD LINEAR ACCELERATOR CTR,STANFORD,CA 94309, USA. NR 21 TC 76 Z9 76 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2821 J9 PHYS REV D JI Phys. Rev. D PD MAR 1 PY 1997 VL 55 IS 5 BP 2584 EP 2590 DI 10.1103/PhysRevD.55.2584 PG 7 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA WL503 UT WOS:A1997WL50300009 ER PT J AU Lee, T AF Lee, T TI One-loop QCD correction for inclusive jet production and Drell-Yan process in composite models SO PHYSICAL REVIEW D LA English DT Article ID GAUGE-THEORIES; AMPLITUDES AB We calculate the one-loop QCD correction for inclusive jet cross sections and Drell-Yan process in a general low-energy effective Lagrangian for composite quarks and leptons. RP Lee, T (reprint author), FERMILAB NATL ACCELERATOR LAB,POB 500,BATAVIA,IL 60510, USA. NR 17 TC 9 Z9 9 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2821 J9 PHYS REV D JI Phys. Rev. D PD MAR 1 PY 1997 VL 55 IS 5 BP 2591 EP 2601 DI 10.1103/PhysRevD.55.2591 PG 11 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA WL503 UT WOS:A1997WL50300010 ER PT J AU Alves, G Levin, E Santoro, A AF Alves, G Levin, E Santoro, A TI Diffractive production of b(b)over-bar in proton-antiproton collisions at the Fermilab Tevatron SO PHYSICAL REVIEW D LA English DT Article ID P(P)OVER-BAR COLLISIONS; PERTURBATION-THEORY; ROOT-S=1.8 TEV; QCD; SCATTERING; APPROXIMATION; DISSOCIATION; BEHAVIOR; QUARK; MODEL AB We show that the cross section of the diffractive production of can be described as the sum of two contributions: the first is proportional to the probability of finding a small size color dipole in the fast hadron wave function before the interaction with a target, while the second is the production after or during the interaction with the target. The formulas are presented as well as the discussion of the interrelation between these two contributions and the Ingelman-Schlein and coherent diffraction mechanisms. The main prediction is that the coherent diffraction mechanism dominates, at least at the Fermilab Tevatron energies, giving the unique possibility to study it experimentally. C1 PETERSBURG NUCL PHYS INST,THEORY DEPT,GATCHINA 188350,RUSSIA. FERMILAB NATL ACCELERATOR LAB,BATAVIA,IL 60510. RP Alves, G (reprint author), CTR BRASILEIRO PESQUISAS FIS,LAFEX,RUA DR XAVIER SIGAUD 150,BR-22290180 RIO JANEIRO,BRAZIL. RI Alves, Gilvan/C-4007-2013 NR 46 TC 7 Z9 7 U1 0 U2 1 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2821 J9 PHYS REV D JI Phys. Rev. D PD MAR 1 PY 1997 VL 55 IS 5 BP 2683 EP 2692 DI 10.1103/PhysRevD.55.2683 PG 10 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA WL503 UT WOS:A1997WL50300020 ER PT J AU Cacciari, M Greco, M Rolli, S Tanzini, A AF Cacciari, M Greco, M Rolli, S Tanzini, A TI Charmed meson fragmentation functions SO PHYSICAL REVIEW D LA English DT Article ID HEAVY-QUARK PRODUCTION; QCD CORRECTIONS; HADRONIC COLLISIONS; FLAVOR PRODUCTION; E+E ANNIHILATION; CROSS-SECTION; MONTE-CARLO; DISTRIBUTIONS; HERA AB Fragmentation functions for heavy-light mesons, like the charmed D, D* mesons, are proposed. They rest on next-to-leading QCD perturbative fragmentation functions Tor heavy quarks. with the addition of a nonperturbative term describing phenomenologically the quark --> meson transition. The cross section for production of large p(T) D, D* mesons al the: Fermilab Tevatron is evaluated in this framework. C1 UNIV ROMA 3,DIPARTIMENTO FIS E AMALDI,ROME,ITALY. IST NAZL FIS NUCL,LAB NAZL FRASCATI,I-00044 FRASCATI,ITALY. LAWRENCE BERKELEY LAB,BERKELEY,CA 94720. IST NAZL FIS NUCL,I-27100 PAVIA,ITALY. UNIV ROMA TOR VERGATA,DIPARTIMENTO FIS,I-00173 ROME,ITALY. IST NAZL FIS NUCL,ROME,ITALY. RP Cacciari, M (reprint author), DESY,NOTKESTR 85,D-2000 HAMBURG,GERMANY. OI Tanzini, Alessandro/0000-0003-4408-1706 NR 24 TC 45 Z9 45 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2821 J9 PHYS REV D JI Phys. Rev. D PD MAR 1 PY 1997 VL 55 IS 5 BP 2736 EP 2740 DI 10.1103/PhysRevD.55.2736 PG 5 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA WL503 UT WOS:A1997WL50300026 ER PT J AU Burdman, G Kambor, J AF Burdman, G Kambor, J TI Dispersive approach to semileptonic form factors in heavy-to-light meson decays SO PHYSICAL REVIEW D LA English DT Article ID QUARK SYMMETRY; B-MESONS; QCD; PREDICTIONS; CONSTANTS AB We study the semileptonic decays of heavy mesons into light pseudoscalars by making use of dispersion relations. Constraints from heavy quark symmetry, chiral symmetry, and perturbative QCD are implemented into a dispersive model for the form factors. Large deviations from B*-pole dominance are observed in B-->pi/nu. We discuss the model prediction for this mode and its possible impact on the extraction of \V-ub\. C1 FERMILAB NATL ACCELERATOR LAB, BATAVIA, IL 60510 USA. INST PHYS NUCL, DIV PHYS THEOR, F-91406 ORSAY, FRANCE. RI Burdman, Gustavo/D-3285-2012 NR 43 TC 23 Z9 24 U1 0 U2 0 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 2470-0010 EI 2470-0029 J9 PHYS REV D JI Phys. Rev. D PD MAR 1 PY 1997 VL 55 IS 5 BP 2817 EP 2826 DI 10.1103/PhysRevD.55.2817 PG 10 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA WL503 UT WOS:A1997WL50300036 ER PT J AU Suzuki, M AF Suzuki, M TI Axial-vector meson mixing in orthocharmonium decays SO PHYSICAL REVIEW D LA English DT Article AB In the light of the recent measurement by the BES Collaboration, the two-body decays of J/psi and psi' into an axial-vector meson and a pseudoscalar meson are analyzed in the framework of the K-A-R(B) mixing including substantial SU(3) and G parity violations due to one-photon annihilation. A somewhat puzzling pattern of the K1+K- decay channel can be understood with no tight constraint on the mixing angle. The ratio of K-1(0)(1400)<(K)over bar (0)> to K-1(0)(1270)<(K)over bar (0)> will be the cleanest source of information to determine the mixing angle from the 1(+)0(-) decays in the presence of one-photon annihilation. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,BERKELEY,CA 94720. RP Suzuki, M (reprint author), UNIV CALIF BERKELEY,DEPT PHYS,BERKELEY,CA 94720, USA. NR 11 TC 15 Z9 15 U1 0 U2 1 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2821 J9 PHYS REV D JI Phys. Rev. D PD MAR 1 PY 1997 VL 55 IS 5 BP 2840 EP 2844 DI 10.1103/PhysRevD.55.2840 PG 5 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA WL503 UT WOS:A1997WL50300040 ER PT J AU Raja, R AF Raja, R TI Measuring the top quark mass using the dilepton decay modes SO PHYSICAL REVIEW D LA English DT Article AB We demonstrate a new likelihood method for extracting the top quark mass from events of the type --> bW(+)(lepton + v)<(b)over bar W->(lepton + v). This method estimates the top quark mass correctly from an ensemble of dilepton events. The method proposed by Dalitz and Goldstein is shown to result in a systematic underestimation of the top quark mass. Effects due to the spin correlations between the top quark and top antiquark are shown to be unimportant in estimating the mass of the top quark. RP Raja, R (reprint author), FERMILAB NATL ACCELERATOR LAB,POB 500,BATAVIA,IL 60510, USA. NR 7 TC 4 Z9 4 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2821 J9 PHYS REV D JI Phys. Rev. D PD MAR 1 PY 1997 VL 55 IS 5 BP 2902 EP 2906 DI 10.1103/PhysRevD.55.2902 PG 5 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA WL503 UT WOS:A1997WL50300046 ER PT J AU Anderson, GW Castano, DJ Riotto, A AF Anderson, GW Castano, DJ Riotto, A TI Naturalness lowers the upper bound on the lightest Higgs boson mass in supersymmetry SO PHYSICAL REVIEW D LA English DT Article ID STANDARD MODEL; RADIATIVE-CORRECTIONS; PHENOMENOLOGY; COLLIDERS; SEARCHES AB We quantify the extent to which naturalness is lost as experimental lower bounds on the Higgs boson mass increase, and we compute the natural upper bound on the Lightest supersymmetric Higgs boson mass. We find that it would be unnatural for the mass of the lightest supersymmetric Higgs boson to saturate its maximal upper bound. In the absence of significant fine-tuning, the lightest Higgs boson mass should Lie below 120 GeV, and in the most natural cases it should be lighter than 108 GeV. For modest tan beta, these bounds are significantly lower. Our results imply that a failure to observe a light Higgs boson in experiments previous to the CERN LHC becoming operational could provide a serious challenge to the principal motivation for weak-scale supersymmetry. C1 FLORIDA STATE UNIV,DEPT PHYS,TALLAHASSEE,FL 32306. RP Anderson, GW (reprint author), FERMILAB NATL ACCELERATOR LAB,POB 500,BATAVIA,IL 60510, USA. OI Anderson, Greg/0000-0003-0346-7258 NR 41 TC 28 Z9 28 U1 0 U2 1 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2821 J9 PHYS REV D JI Phys. Rev. D PD MAR 1 PY 1997 VL 55 IS 5 BP 2950 EP 2954 DI 10.1103/PhysRevD.55.2950 PG 5 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA WL503 UT WOS:A1997WL50300050 ER PT J AU Atwood, D Reina, L Soni, A AF Atwood, D Reina, L Soni, A TI Phenomenology of two Higgs doublet models with flavor-changing neutral currents SO PHYSICAL REVIEW D LA English DT Article ID HEAVY TOP-QUARK; LEADING LOGARITHMS; QCD CORRECTIONS; MU(+)MU(-) COLLIDERS; MASS DIFFERENCE; MU+MU COLLIDER; MUON COLLIDER; CP VIOLATION; B->SG DECAYS; WEAK-SCALE AB A comprehensive phenomenological analysis of a two Higgs doublet model, with flavor-changing scalar currents at the tree level, called model III, is presented. Constraints from existing experimental information especially an Delta F=2 processes are systematically incorporated. Constraints emerging from rare B decays, b(b)over bar>, and the rho parameter are also examined. Experimental implications for e(+)e(-)(mu(+)mu(-))-->+<(t)over bar c>, t-->c gamma(Z,g), D-0-(D-0) over bar,and B-s(0)-<(B-s(0))over bar> oscillations, and far e(+)e(-)(Z)-->+<(b)over bar s> investigated and experimental effort towards these is stressed. We also emphasize the importance of clarifying the experimental issues pertaining to Z-->. C1 BROOKHAVEN NATL LAB, DEPT PHYS, UPTON, NY 11973 USA. BROOKHAVEN NATL LAB, DEPT PHYS, UPTON, NY 11973 USA. RP CONTINUOUS ELECTRON BEAM ACCELERATOR FACIL CTR, THEORY GRP, NEWPORT NEWS, VA 23606 USA. NR 64 TC 282 Z9 283 U1 0 U2 1 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 2470-0010 EI 2470-0029 J9 PHYS REV D JI Phys. Rev. D PD MAR 1 PY 1997 VL 55 IS 5 BP 3156 EP 3176 DI 10.1103/PhysRevD.55.3156 PG 21 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA WL503 UT WOS:A1997WL50300072 ER PT J AU Bagger, JA Matchev, KT Pierce, DM Zhang, RJ AF Bagger, JA Matchev, KT Pierce, DM Zhang, RJ TI Weak-scale phenomenology of models with gauge-mediated supersymmetry breaking SO PHYSICAL REVIEW D LA English DT Article AB We study in some detail the spectral phenomenology of models in which supersymmetry is dynamically broken and transmitted to the supersymmetric partners of the quarks, leptons, and gauge bosons, and the Higgs bosons themselves, via the usual gauge interactions. We elucidate the parameter space of what we consider to be the minimal model, and explore the regions which give rise to consistent radiative electroweak symmetry breaking. We include the weak-scale threshold corrections, and show how they considerably reduce the scale dependence of the results. We examine the sensitivity of. our results to unknown higher-order messenger-sector corrections. We compute the superpartner spectrum across the entire parameter space, and compare it to that of the minimal supergravity-inspired model. We delineate the regions where the Lightest neutralino or tau slepton is the next-to-lightest supersymmetric particle, and compute the lifetime and branching ratios of the NLSP. In contrast with the minimal supergravity-inspired model, we find that the lightest neutralino can have a large Higgsino component, of order 50%. Nevertheless, the neutralino branching fraction to the gravitino and the light Higgs boson remains small, less than or similar to 10(-4), so the observation of such a decay would point to a nonminimal Higgs sector. C1 STANFORD UNIV,STANFORD LINEAR ACCELERATOR CTR,STANFORD,CA 94309. RP Bagger, JA (reprint author), JOHNS HOPKINS UNIV,DEPT PHYS & ASTRON,BALTIMORE,MD 21218, USA. NR 22 TC 101 Z9 101 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2821 J9 PHYS REV D JI Phys. Rev. D PD MAR 1 PY 1997 VL 55 IS 5 BP 3188 EP 3200 DI 10.1103/PhysRevD.55.3188 PG 13 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA WL503 UT WOS:A1997WL50300074 ER PT J AU Datta, A Zhang, X AF Datta, A Zhang, X TI Nonuniversal correction to Z->b(b)over-bar and single top quark production at Fermilab Tevatron SO PHYSICAL REVIEW D LA English DT Article ID CHANGING NEUTRAL CURRENTS; SYMMETRY-BREAKING; FLAVOR PHYSICS; COUPLINGS; HIERARCHIES; TOPCOLOR AB New physics associated with the heavy top quark can affect top quark production and the partial decay width of Z-->. In this paper, we examine the Correlated effects of possible new physics on R(b) measured at CERN LEP I and the single top quark production rate at the Fermilab Tevatron by using an effective Lagrangian technique. We point out that certain operators in the effective Lagrangian, constrained by the measured value of R(b), can lead to significant and potentially observable effects in single top quark production. C1 CCAST,WORLD LAB,BEIJING 100080,PEOPLES R CHINA. ACAD SINICA,INST HIGH ENERGY PHYS,BEIJING 100039,PEOPLES R CHINA. FERMILAB NATL ACCELERATOR LAB,BATAVIA,IL 60510. RP Datta, A (reprint author), IOWA STATE UNIV SCI & TECHNOL,DEPT PHYS & ASTRON,AMES,IA 50011, USA. NR 35 TC 26 Z9 27 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2821 J9 PHYS REV D JI Phys. Rev. D PD MAR 1 PY 1997 VL 55 IS 5 BP R2530 EP R2532 PG 3 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA WL503 UT WOS:A1997WL50300004 ER PT J AU Shan, XW AF Shan, XW TI Simulation of Rayleigh-Benard convection using a lattice Boltzmann method SO PHYSICAL REVIEW E LA English DT Article ID NAVIER-STOKES EQUATION; GAS AUTOMATA; MODEL; TRANSITION; NUMBER; FLUID; FLOW AB Rayleigh-Benard convection is numerically simulated in two and three dimensions using a recently developed two-component lattice Boltzmann equation (LBE) method. The density field of the second component, which evolves according to the advection-diffusion equation of a passive scalar, is used to simulate the temperature field. A body force proportional to the temperature is applied, and the system satisfies the Boussinesq equation except for a slight compressibility. A no-slip, isothermal boundary condition is imposed in the vertical direction, and periodic boundary conditions are used in horizontal directions. The critical Rayleigh number for the onset of the Rayleigh-Benard convection agrees with the theoretical prediction. As the Rayleigh number is increased higher, the steady two-dimensional convection rolls become unstable. The wavy instability and aperiodic motion observed, as well as the Nusselt number as a function of the Rayleigh number, are in good agreement with experimental observations and theoretical predictions. The LEE model is found to be efficient, accurate, and numerically stable for the simulation of fluid flows with heat and mass transfer. C1 LOS ALAMOS NATL LAB,DIV THEORET,LOS ALAMOS,NM 87545. RP Shan, XW (reprint author), USAF,PHILLIPS LAB,HANSCOM AFB,MA 01731, USA. RI Shan, Xiaowen/H-2836-2013 OI Shan, Xiaowen/0000-0002-6350-9248 NR 32 TC 282 Z9 299 U1 4 U2 51 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 MAR PY 1997 VL 55 IS 3 BP 2780 EP 2788 DI 10.1103/PhysRevE.55.2780 PN A PG 9 WC Physics, Fluids & Plasmas; Physics, Mathematical SC Physics GA WN934 UT WOS:A1997WN93400085 ER PT J AU Agamalian, M Drake, JM Sinha, SK Axe, JD AF Agamalian, M Drake, JM Sinha, SK Axe, JD TI Neutron diffraction study of the pore surface layer of Vycor glass SO PHYSICAL REVIEW E LA English DT Article ID SMALL-ANGLE SCATTERING; ENERGY-TRANSFER; POROUS-GLASS; WATER; ADSORPTION; DIFFUSION; GEOMETRY; ICE AB Analysis of small-angle scattering and powder diffraction data combined with macroscopic measurements have revealed the structure of a pore surface layer in Vycor glass, consisting of OH groups and chemisorbed water. Chemisorbed water exists on the pore surface in two forms: compact water clusters of similar to 40-60 molecules, connected to each other by hydrogen bonds, and more spaciously distributed individual molecules (or groups of several molecules). Heating to 650 degrees C reconstructs the pore surface: the number of OH groups is significantly decreasing due to the reaction of dehydration between Si-OH and B-OH surface groups. However, the temperature treatment does not affect the process of H2O clusters formation, which still appear on the pore surface after the condensation. C1 EXXON RES & ENGN CO,ANNANDALE,NJ 08801. ARGONNE NATL LAB,ARGONNE,IL 60439. BROOKHAVEN NATL LAB,UPTON,NY 11973. OI Agamalian, Michael/0000-0002-9112-2534 NR 26 TC 40 Z9 40 U1 1 U2 6 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 MAR PY 1997 VL 55 IS 3 BP 3021 EP 3027 DI 10.1103/PhysRevE.55.3021 PN B PG 7 WC Physics, Fluids & Plasmas; Physics, Mathematical SC Physics GA WN935 UT WOS:A1997WN93500006 ER PT J AU Ocko, BM Wu, XZ Sirota, EB Sinha, SK Gang, O Deutsch, M AF Ocko, BM Wu, XZ Sirota, EB Sinha, SK Gang, O Deutsch, M TI Surface freezing in chain molecules: Normal alkanes SO PHYSICAL REVIEW E LA English DT Article ID X-RAY REFLECTIVITY; LIQUID NORMAL-ALKANES; ROTATOR PHASES; N-ALKANES; NUMBERED PARAFFINS; CAPILLARY WAVES; CRYSTAL FILMS; LANDAU THEORY; LAYER GROWTH; TRANSITIONS AB A rare surface freezing phenomenon is observed in molten normal alkanes, using x-ray and surface tension measurements. An ordered monolayer forms on the surface of the liquid alkane at temperatures up to 3 degrees C above the bulk freezing temperature T-f. The structure of the monolayer was studied in detail for a wide range of molecular lengths and temperatures. The single layer formed persists down to T-f. The rare surface phase exists only for carbon numbers of 16 less than or equal to n less than or equal to 50. The molecules in the layer are hexagonally packed and show three distinct ordered phases: two rotator phases, with molecules oriented vertically (16 less than or equal to n less than or equal to 30) and tilted towards nearest neighbors (30 eta pi(0) pi(0)n is analyzed for mass values up to 1.9 GeV. Data used in this analysis come from the GAMS-4000 multiphoton spectrometer irradiated by a 100-GeV/c pi(-) beam of the SPS accelerator at CERN. Experimental mass spectra show distinct signals from the pseudoscalar mesons eta(1295) and iota/eta(1440) and from the axial-vector meson D/f(1)(1285). The values found for their masses and widths agree well with the world-average values. The cross sections for the production of the above mesons are measured, and the relative branching fractions for some of their decays are estimated. The decay eta(1295) --> eta pi(0) pi is found to be dominated by the a(0)(980)pi 0 channel. On the other hand, the decay iota/eta(1440) --> a(0)(980)pi(0) is dominated by the eta(pi(0) pi(0))(s) channel, whereas the a(0)(980)pi 0 contribution is small. This suggests that iota is an exotic meson with a significant component of valence gluons. C1 INST HIGH ENERGY PHYS,STATE RES CTR,PROTVINO 142284,MOSCOW OBLAST,RUSSIA. ULB VUB,INTERUNIV INST NUCL RES,B-1052 BRUSSELS,BELGIUM. LAB ANNECY LE VIEUX PHYS PARTICULES,F-74941 ANNECY LE VIEUX,FRANCE. FREE UNIV BRUSSELS,TSUKUBA,IBARAKI,JAPAN. MIYAZAKI UNIV,MIYAZAKI,JAPAN. NAGOYA UNIV,NAGOYA,AICHI,JAPAN. UNIV MONTREAL,MONTREAL,PQ H3C 3J7,CANADA. RP Alde, D (reprint author), LOS ALAMOS NATL LAB,POB 1663,LOS ALAMOS,NM 87545, USA. NR 23 TC 16 Z9 16 U1 0 U2 1 PU MAIK NAUKA/INTERPERIODICA PUBL PI WOODBURY PA C/O AMERICAN INST PHYSICS, 500 SUNNYSIDE BLVD, MEMBER SUBSCRIBER SERVICES, WOODBURY, NY 11797-2999 SN 1063-7788 J9 PHYS ATOM NUCL+ JI Phys. Atom. Nuclei PD MAR PY 1997 VL 60 IS 3 BP 386 EP 390 PG 5 WC Physics, Nuclear; Physics, Particles & Fields SC Physics GA WQ647 UT WOS:A1997WQ64700009 ER PT J AU Ladd, AJC AF Ladd, AJC TI Sedimentation of homogeneous suspensions of non-Brownian spheres SO PHYSICS OF FLUIDS LA English DT Article ID DISCRETIZED BOLTZMANN-EQUATION; PARTICULATE SUSPENSIONS; HYDRODYNAMIC DIFFUSION; NUMERICAL SIMULATIONS; HARD-SPHERES; DISPERSION; PARTICLES AB Dynamical simulations of bull; sedimentation have been carried out, using up to 32 000 solid particles. There is no evidence that the long-range hydrodynamic interactions are screened by changes in the pair correlation function at large distances. Instead the velocity fluctuations and diffusion coefficients diverge linearly with the width of the container, consistent with the random long-range microstructures observed in the simulations. Our data suggest that other mechanisms must be uncovered to account for experimental observations. (C) 1997 American Institute of Physics. RP Ladd, AJC (reprint author), LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550, USA. NR 16 TC 149 Z9 151 U1 2 U2 21 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 1070-6631 J9 PHYS FLUIDS JI Phys. Fluids PD MAR PY 1997 VL 9 IS 3 BP 491 EP 499 DI 10.1063/1.869212 PG 9 WC Mechanics; Physics, Fluids & Plasmas SC Mechanics; Physics GA WK494 UT WOS:A1997WK49400003 ER PT J AU Baumert, BM Muller, SJ AF Baumert, BM Muller, SJ TI Flow regimes in model viscoelastic fluids in a circular couette system with independently rotating cylinders SO PHYSICS OF FLUIDS LA English DT Article ID INSTABILITY AB Flow visualization of two highly elastic, nonshear-thinning polyisobutylene/polybutene fluids in the gap between concentric cylinders was performed over a range of shear rates and choices of relative cylinder rotations. The observed secondary flows are discussed in terms of destabilizing elastic and centrifugal forces. In the more viscous, more elastic fluid, instabilities are found to be independent of the choice of rotating cylinder and due entirely to elasticity. At the lowest shear rates examined, the first detectable secondary flows are steady counter-rotating vortices forming after a shearing time more than five orders of magnitude greater than the characteristic relaxation time of the fluid. At somewhat higher shear rates, a much more rapidly appearing oscillatory flow is observed to evolve into the steady vortex structure. In the less elastic fluid, the structure first detectable at the lowest shear rates is again steady vortices regardless of the choice of driving cylinder, At all shear rates examined, only elastic stationary vortices are observed in the absence of centrifugal destabilization (outer cylinder rotating). Secondary flows are significantly stronger in the presence of the centrifugal destabilization due to a rotating inner cylinder. Interaction of elasticity and centrifugal forces is round to generate a number of axially translating vortex structures, many of which are described here for the first lime. At a shear rate more than five times the critical, another family of instability is observed which closely resembles a purely elastic instability observed by Baumert and Muller (1995). These experimental results are expected to provide a challenging test of numerical simulations of these viscoelastic flows. (C) 1997 American Institute of Physics. C1 UNIV CALIF BERKELEY,DEPT CHEM ENGN,BERKELEY,CA 94720. UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,CTR ADV MAT,BERKELEY,CA 94720. NR 26 TC 29 Z9 30 U1 3 U2 8 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 1070-6631 J9 PHYS FLUIDS JI Phys. Fluids PD MAR PY 1997 VL 9 IS 3 BP 566 EP 586 DI 10.1063/1.869209 PG 21 WC Mechanics; Physics, Fluids & Plasmas SC Mechanics; Physics GA WK494 UT WOS:A1997WK49400010 ER PT J AU Guilkey, JE Kerstein, AR McMurtry, PA Klewicki, JC AF Guilkey, JE Kerstein, AR McMurtry, PA Klewicki, JC TI Mixing mechanisms in turbulent pipe flow SO PHYSICS OF FLUIDS LA English DT Article ID LAYER AB An experimental investigation of passive scalar mixing in turbulent pipe flow is carried out using a new non-intrusive scalar initialization technique. The measurements support a recently predicted similarity scaling of concentration spectra in flows that are unbounded in one direction. Reflecting this scaling, the scalar variance exhibits a power-law rather than exponential decay, indicating that the traditional plug-flow reactor picture of turbulent pipe-flow mixing omits key physical mechanisms. (C) 1997 American Institute of Physics. C1 SANDIA NATL LABS,COMBUST RES FACIL,LIVERMORE,CA 94551. RP Guilkey, JE (reprint author), UNIV UTAH,DEPT MECH ENGN,SALT LAKE CITY,UT 84112, USA. OI Klewicki, Joseph/0000-0002-4921-3272 NR 11 TC 11 Z9 11 U1 0 U2 2 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 1070-6631 J9 PHYS FLUIDS JI Phys. Fluids PD MAR PY 1997 VL 9 IS 3 BP 717 EP 723 DI 10.1063/1.869211 PG 7 WC Mechanics; Physics, Fluids & Plasmas SC Mechanics; Physics GA WK494 UT WOS:A1997WK49400021 ER PT J AU Krommes, JA AF Krommes, JA TI The clump lifetime revisited: Exact calculation of the second-order structure function for a model of forced, dissipative turbulence SO PHYSICS OF PLASMAS LA English DT Article ID GRADIENT-DRIVEN TURBULENCE; REALIZABLE MARKOVIAN CLOSURE; PLASMA TURBULENCE; 2-DIMENSIONAL TURBULENCE; TRANSPORT; PREDICTABILITY; ROTATION; DYNAMICS; ENTROPY; EDGE AB The role of the clump lifetime tau(cl), logarithmically dependent on small scales, in determining the fluctuation level for forced, dissipative turbulence is reconsidered with the aid of an exactly solvable rapid-change model of passive advection. It is shown in mathematical detail that the common procedure of approximating the steady-state fluctuation lever I by tau(cl)P, where p is the production rate or source of fluctuations, is invalid when a clean distinction can be made between energy-containing and inertial ranges. The correct result is I approximate to tau(D), where tau(D) is a macroscopic diffusion time that does not depend on the small scales. (C) 1997 American Institute of Physics. RP Krommes, JA (reprint author), PRINCETON UNIV,PLASMA PHYS LAB,PRINCETON,NJ 08543, USA. NR 56 TC 9 Z9 9 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 1070-664X J9 PHYS PLASMAS JI Phys. Plasmas PD MAR PY 1997 VL 4 IS 3 BP 655 EP 673 DI 10.1063/1.872148 PG 19 WC Physics, Fluids & Plasmas SC Physics GA WL771 UT WOS:A1997WL77100018 ER PT J AU DeGroot, JS Toor, A Golberg, SM Liberman, MA AF DeGroot, JS Toor, A Golberg, SM Liberman, MA TI Growth of the Rayleigh-Taylor instability in an imploding Z-pinch SO PHYSICS OF PLASMAS LA English DT Article ID ULTRAHIGH MAGNETIC-FIELDS; PUFF Z-PINCH; PLASMA; COMPRESSIBILITY; SUPPRESSION; CONVECTION AB Rayleigh-Taylor (RT) instability of cylindrical, imploding plasma Liners in a Z-pinch is analysed. The reduction in total perturbation growth for multicascade systems (multiple imploding shells) is presented. This reduction is effective if the pressure produced by the impacting shell exceeds the magnetic pressure at the time of impact. Analytical and numerical solutions are also obtained for the RT instability of an imploding plasma liner accelerated into undisturbed plasma. The snowplow model is used in which the mass encountered by the imploding magnetic piston is swept into an infinitely thin sheath. A shock front launched ahead of the liner is shown to reduce the growth rate. It is also shown that accumulating the mass increases the growth rate. However, the total perturbation growth can be reduced if the liner accumulates the mass during the implosion compared to a liner with the same mass imploding into vacuum. Finally, it is shown that the final kinetic energy density for a given shell nonuniformity is largest if the final liner mass is accumulated during the implosion. (C) 1997 American Institute of Physics. C1 UNIV UPPSALA, DEPT PHYS, S-75121 UPPSALA, SWEDEN. PL KAPITZA PHYS PROBLEMS INST, MOSCOW 117334, RUSSIA. RP LAWRENCE LIVERMORE NATL LAB, LIVERMORE, CA 94550 USA. OI liberman, michael/0000-0002-2800-2919 NR 31 TC 28 Z9 29 U1 0 U2 2 PU AMER INST PHYSICS PI MELVILLE PA 1305 WALT WHITMAN RD, STE 300, MELVILLE, NY 11747-4501 USA SN 1070-664X EI 1089-7674 J9 PHYS PLASMAS JI Phys. Plasmas PD MAR PY 1997 VL 4 IS 3 BP 737 EP 747 DI 10.1063/1.872168 PG 11 WC Physics, Fluids & Plasmas SC Physics GA WL771 UT WOS:A1997WL77100026 ER PT J AU Qin, H Reiman, A AF Qin, H Reiman, A TI Free-boundary, high-beta equilibrium in a large aspect ratio tokamak with nearly circular plasma boundary SO PHYSICS OF PLASMAS LA English DT Article AB An analytic solution is obtained for free-boundary, high-beta equilibria in large aspect ratio tokamaks with a nearly circular plasma boundary. In the absence of surface currents at the plasma-vacuum interface, the free-boundary equilibrium solution introduces constraints arising from the need to couple to an external vacuum held which is physically realizable with a reasonable set of external field coils. This places a strong constraint on the pressure profiles that are consistent with a given boundary shape at high epsilon beta(p). The equilibrium solution also provides information on the flux surface topology. The plasma is bounded by a separatrix. Increasing the plasma pressure at fixed total current causes the plasma aperture to decrease in a manner that is described. (C) 1997 American Institute of Physics. RP Qin, H (reprint author), PRINCETON UNIV,PRINCETON PLASMA PHYS LAB,POB 451,PRINCETON,NJ 08543, USA. NR 4 TC 2 Z9 2 U1 0 U2 4 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 1070-664X J9 PHYS PLASMAS JI Phys. Plasmas PD MAR PY 1997 VL 4 IS 3 BP 762 EP 770 DI 10.1063/1.872170 PG 9 WC Physics, Fluids & Plasmas SC Physics GA WL771 UT WOS:A1997WL77100029 ER PT J AU Shaing, KC Hazeltine, RD Zarnstorff, MC AF Shaing, KC Hazeltine, RD Zarnstorff, MC TI Ion transport process around magnetic axis in tokamaks SO PHYSICS OF PLASMAS LA English DT Article ID CONFINEMENT; PLASMAS AB Ion transport in the region close to the magnetic axis in tokamaks is investigated by solving the drift kinetic equation with the proper orbit topology taken into account. It is found that ion thermal conductivity remains finite in that region. The scaling of the thermal conductivity can be understood in terms of st random walk process in units of the poloidal flux. (C) 1997 American Institute of Physics. C1 PRINCETON PLASMA PHYS LAB,PRINCETON,NJ 08543. RP Shaing, KC (reprint author), UNIV TEXAS,INST FUS STUDIES,AUSTIN,TX 78712, USA. NR 12 TC 39 Z9 39 U1 1 U2 2 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 1070-664X J9 PHYS PLASMAS JI Phys. Plasmas PD MAR PY 1997 VL 4 IS 3 BP 771 EP 777 DI 10.1063/1.872171 PG 7 WC Physics, Fluids & Plasmas SC Physics GA WL771 UT WOS:A1997WL77100030 ER PT J AU Ze, F Langer, SH Kauffman, RL Kilkenny, JD Landen, O Ress, D Rosen, MD Suter, LJ Wallace, RJ Wiedwald, JD AF Ze, F Langer, SH Kauffman, RL Kilkenny, JD Landen, O Ress, D Rosen, MD Suter, LJ Wallace, RJ Wiedwald, JD TI A comparative study of x-ray emission from laser spots in laser-heated hohlraums relative to spots on simple disk targets SO PHYSICS OF PLASMAS LA English DT Article ID INERTIAL CONFINEMENT FUSION; MU-M; CAVITIES; PLASMAS; SPECTRA; LIGHT AB In this paper we report the results of experiments that compare the x-ray emission from a laser spot in a radiation-filled hohlraum to that from a similar laser spot on a simple disk target. The studies were done using the Nova laser facility [J. D. Lindl, Phys. Plasmas 2,3933 (1995)] in its 0.35 mu m wavelength, 1 ns square pulse configuration. Focal spot intensities were 2-3.5x10(15) W/cm(2). X-ray images measured x-ray conversion in a hohlraum and from an isolated disk simultaneously. A laser spot inside a hohlraum emitted more x rays, after subtracting the background emission from the hohlraum walls, than a spot on a disk. Numerical models suggest the enhanced spot emission inside the hohlraum is due to an increase in lateral transport relative to the disk. Filamentation in the hohlraum will also increase the spot size. The models agree fairly well with the results on spot spreading but do not explain the overall increase in conversion efficiency. (C) 1997 American Institute of Physics. RP Ze, F (reprint author), LAWRENCE LIVERMORE NATL LAB,POB 808,LIVERMORE,CA 94550, USA. NR 24 TC 8 Z9 8 U1 2 U2 5 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 1070-664X J9 PHYS PLASMAS JI Phys. Plasmas PD MAR PY 1997 VL 4 IS 3 BP 778 EP 787 DI 10.1063/1.872172 PG 10 WC Physics, Fluids & Plasmas SC Physics GA WL771 UT WOS:A1997WL77100031 ER PT J AU Lawson, WS Rambo, PW Larson, DJ AF Lawson, WS Rambo, PW Larson, DJ TI One-dimensional simulations of ultrashort intense laser pulses on solid-density targets SO PHYSICS OF PLASMAS LA English DT Article ID PLASMA INTERACTIONS; ABSORPTION; LIGHT AB Presented are simulations in one dimension of laser pulses with a pre-ionized thin target. The duration of the laser pulse is between 10 and 200 fs, the laser power is between 10(18) and 10(22) W/cm(2), and the wavelength is 400 nm. The targets were foils of either aluminum at normal density, or in a few cases plastic (chemical formula CH) at a density of 1.1 g/cm(3), and varied from 20 to 4000 nm in thickness. The simulation results show that at these intensities the absorption mechanism for a normally incident pulse changes to a collisionless mechanism first proposed by kruer and Estabrook [W. L. Kruer and Ii. Estabrook, Phys. Fluids 28, 430 (1985)]. Use of a thin target ensures that the energy imparted to the electrons will be electrostatically transferred to the ions rather than transported for large distances into the target. (C) 1997 American Institute of Physics. RP LAWRENCE LIVERMORE NATL LAB, POB 808, LIVERMORE, CA 94551 USA. OI Larson, David/0000-0003-0814-8555 NR 15 TC 33 Z9 34 U1 0 U2 2 PU AMER INST PHYSICS PI MELVILLE PA 1305 WALT WHITMAN RD, STE 300, MELVILLE, NY 11747-4501 USA SN 1070-664X EI 1089-7674 J9 PHYS PLASMAS JI Phys. Plasmas PD MAR PY 1997 VL 4 IS 3 BP 788 EP 795 DI 10.1063/1.872173 PG 8 WC Physics, Fluids & Plasmas SC Physics GA WL771 UT WOS:A1997WL77100032 ER PT J AU Fawley, WM Garvey, T Eylon, S Henestroza, E Faltens, A Fessenden, TJ Hahn, K Smith, L Grote, DP AF Fawley, WM Garvey, T Eylon, S Henestroza, E Faltens, A Fessenden, TJ Hahn, K Smith, L Grote, DP TI Beam dynamics studies with the heavy-ion linear induction accelerator MBE-4 SO PHYSICS OF PLASMAS LA English DT Article ID PARTICLE BEAMS; EMITTANCE; ENERGY AB Current amplification of heavy-ion beams is an integral feature of the induction linac approach to heavy-ion fusion (HIF). in this paper we report on amplification experiments conducted on a single beam of the Multiple Beam Experiment (MBE-4), a heavy-ion (Cs+) induction linac. Earlier MBE-4 experiments [H. Meuth et al., Nucl. Instrum. Methods Phys. Res. A 278, 153 (1989)] had demonstrated up-to-9X current amplification but had been accompanied by an up-to-2X increase of normalized transverse emittance. Experiments to pinpoint the causes of this emittance growth indicated various factors were responsible, including focusing aberrations and mismatch difficulties between the injector diode and the accelerator transport lattice, a localized quadrupole misalignment problem, and the interaction of transversely large beams with the nonlinear elements of the focusing lattice. Following ameliorative measures, new current amplification experiments, both with and without acceleration, showed that current amplifications of up to 3X and line charge density increases of up to approximate to 2X could be achieved without increasing the beam's normalized transverse emittance. Finally, both the transverse beam dynamics, and beam current and energy measurements were accurately modeled by numerical particle-in-cell simulations and longitudinal dynamics codes, respectively. (C) 1997 American Institute of Physics. C1 LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94551. RP Fawley, WM (reprint author), LAWRENCE BERKELEY LAB,BERKELEY,CA 94720, USA. NR 24 TC 24 Z9 24 U1 0 U2 1 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 1070-664X J9 PHYS PLASMAS JI Phys. Plasmas PD MAR PY 1997 VL 4 IS 3 BP 880 EP 894 DI 10.1063/1.872147 PG 15 WC Physics, Fluids & Plasmas SC Physics GA WL771 UT WOS:A1997WL77100041 ER PT J AU Mahan, G Sales, B Sharp, J AF Mahan, G Sales, B Sharp, J TI Thermoelectric materials: New approaches to an old problem SO PHYSICS TODAY LA English DT Article ID THERMAL-CONDUCTIVITY; FIGURE; MERIT; LAFE4P12; SUPERLATTICES; TEMPERATURE; CRYSTALS C1 UNIV TENNESSEE,KNOXVILLE,TN. RP Mahan, G (reprint author), OAK RIDGE NATL LAB,OAK RIDGE,TN 37830, USA. NR 24 TC 543 Z9 560 U1 18 U2 141 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0031-9228 J9 PHYS TODAY JI Phys. Today PD MAR PY 1997 VL 50 IS 3 BP 42 EP 47 DI 10.1063/1.881752 PG 6 WC Physics, Multidisciplinary SC Physics GA WK805 UT WOS:A1997WK80500009 ER PT J AU Howes, RH Herzenberg, CL AF Howes, RH Herzenberg, CL TI Calculating women had major wartime roles at Los Alamos SO PHYSICS TODAY LA English DT Letter C1 ARGONNE NATL LAB,ARGONNE,IL 60439. RP Howes, RH (reprint author), BALL STATE UNIV,MUNCIE,IN 47306, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0031-9228 J9 PHYS TODAY JI Phys. Today PD MAR PY 1997 VL 50 IS 3 BP 105 EP 106 DI 10.1063/1.881686 PG 2 WC Physics, Multidisciplinary SC Physics GA WK805 UT WOS:A1997WK80500027 ER PT J AU Cook, DR VandenBosch, K deBruijn, FJ Huguet, T AF Cook, DR VandenBosch, K deBruijn, FJ Huguet, T TI Model legumes get the nod SO PLANT CELL LA English DT Editorial Material ID NODULATION MUTANTS; INFECTION; GENETICS; ROOT C1 TEXAS A&M UNIV,DEPT MICROBIOL,COLLEGE STN,TX 77843. TEXAS A&M UNIV,CROP BIOTECHNOL CTR,COLLEGE STN,TX 77843. TEXAS A&M UNIV,DEPT BIOL,COLLEGE STN,TX 77843. MICHIGAN STATE UNIV,US DOE,PLANT RES LAB,E LANSING,MI 48824. INRA,CNRS,LAB BIOL MOL RELAT PLANTES MICROOGRANISMES,F-31326 CASTANET TOLOSAN,FRANCE. RP Cook, DR (reprint author), TEXAS A&M UNIV,DEPT PLANT PATHOL,COLLEGE STN,TX 77843, USA. NR 35 TC 73 Z9 79 U1 0 U2 2 PU AMER SOC PLANT PHYSIOLOGISTS PI ROCKVILLE PA 15501 MONONA DRIVE, ROCKVILLE, MD 20855 SN 1040-4651 J9 PLANT CELL JI Plant Cell PD MAR PY 1997 VL 9 IS 3 BP 275 EP 281 PG 7 WC Biochemistry & Molecular Biology; Plant Sciences; Cell Biology SC Biochemistry & Molecular Biology; Plant Sciences; Cell Biology GA WQ649 UT WOS:A1997WQ64900002 ER PT J AU Trebitsh, T Staub, JE ONeill, SD AF Trebitsh, T Staub, JE ONeill, SD TI Identification of a 1-aminocyclopropane-1-carboxylic acid synthase gene linked to the female (F) locus that enhances female sex expression in cucumber SO PLANT PHYSIOLOGY LA English DT Article ID MESSENGER-RNA; ETHYLENE BIOSYNTHESIS; 2 GENES; ARABIDOPSIS-THALIANA; MULTIGENE FAMILY; FLOWERING PLANTS; AUXIN; TOMATO; SATIVUS; CLONING AB Sex determination in cucumber (Cucumis sativus L.) is controlled largely by three genes: F, m, and a. The F and m loci interact to produce monoecious (M_f_) or gynoecious (M_F_) sex phenotypes. Ethylene and factors that induce ethylene biosynthesis, such as 1-aminocyclopropane-1-carboxylate (ACC) and auxin, also enhance female sex expression. A genomic sequence (CS-ACS1) encoding ACC synthase was amplified from genomic DNA by a polymerase chain reaction using degenerate oligonucleotide primers. Expression of CS-ACS1 is induced by auxin, but not by ACC, in wounded and intact shoot apices. Southern blot hybridization analysis of near-isogenic gynoecious (MMFF) and monoecious (MMff) lines derived from diverse genetic backgrounds revealed the existence of an additional ACC synthase (CS-ACS1G) genomic sequence in the gynoecious lines. Sex phenotype analysis of a segregating F-2 population detected a 100% correlation between the CS-ACS1G marker and the presence of the F locus. The CS-ACS1G gene is located in linkage group B coincident with the F locus, and in the population tested there was no recombination between the CS-ACS1G gene and the F locus. Collectively, these data suggest that CS-ACS1G is closely linked to the F locus and may play a pivotal role in the determination of sex in cucumber flowers. C1 LAWRENCE LIVERMORE NATL LAB,DIV BIOL SCI,PLANT BIOL SECT,DAVIS,CA 95616. UNIV WISCONSIN,DEPT HORT,USDA ARS,VEGETABLE CROPS UNIT,MADISON,WI 53706. NR 50 TC 113 Z9 149 U1 3 U2 15 PU AMER SOC PLANT PHYSIOLOGISTS PI ROCKVILLE PA 15501 MONONA DRIVE, ROCKVILLE, MD 20855 SN 0032-0889 J9 PLANT PHYSIOL JI Plant Physiol. PD MAR PY 1997 VL 113 IS 3 BP 987 EP 995 DI 10.1104/pp.113.3.987 PG 9 WC Plant Sciences SC Plant Sciences GA WN068 UT WOS:A1997WN06800037 PM 9085580 ER PT J AU Bonivert, WD Cushnie, G AF Bonivert, WD Cushnie, G TI Update of NMFRC user-statistics SO PLATING AND SURFACE FINISHING LA English DT Editorial Material C1 CAI ENGN,OAKTON,VA 22124. RP Bonivert, WD (reprint author), SANDIA NATL LABS,M-S 9404,BOX 969,LIVERMORE,CA 94551, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER ELECTROPLATERS SOC INC PI ORLANDO PA 12644 RESEARCH PKWY, ORLANDO, FL 32826-3298 SN 0360-3164 J9 PLAT SURF FINISH JI Plat. Surf. Finish. PD MAR PY 1997 VL 84 IS 3 BP 43 EP 45 PG 3 WC Metallurgy & Metallurgical Engineering; Materials Science, Coatings & Films SC Metallurgy & Metallurgical Engineering; Materials Science GA WL695 UT WOS:A1997WL69500011 ER PT J AU Henke, KR Bryan, JC Elless, MP AF Henke, KR Bryan, JC Elless, MP TI Structure and powder diffraction pattern of 2,4,6-trimercapto-s-triazine, trisodium salt (Na3S3C3N3 center dot 9H2O) SO POWDER DIFFRACTION LA English DT Article AB 2,4,6-Trimercapto-s-triazine, trisodium salt (ideally, Na3S3C3N3 . 9H(2)O), also known as TMT-55, is a white powder that is used to precipitate heavy metals from contaminated waters. Chemical analyses confirmed the nominal composition. TMT-55 crystals are uniaxial negative with indices of refraction (25 degrees C) of n(epsilon)=1.520 and n(omega)=1.675. The structure was determined by single-crystal methods at 25 and -110 degrees C. A powder pattern was determined and compared to a simulated pattern based on the 25 degrees C structure data. Crystal data at 25 degrees C are: ; Z=6; a=17.600(1) Angstrom and c=9.720(2) Angstrom; V=2607.5(5) Angstrom(3); D-x=1.55 g/cm(3). (C) 1997 International Centre for Diffraction Data. C1 OAK RIDGE NATL LAB,OAK RIDGE,TN 37831. UNIV TENNESSEE,DEPT PLANT & SOIL SCI,KNOXVILLE,TN 37996. RP Henke, KR (reprint author), UNIV N DAKOTA,ENERGY & ENVIRONM RES CTR,POB 9018,GRAND FORKS,ND 58202, USA. NR 11 TC 15 Z9 15 U1 2 U2 6 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0885-7156 J9 POWDER DIFFR JI Powder Diffr. PD MAR PY 1997 VL 12 IS 1 BP 7 EP 12 PG 6 WC Materials Science, Characterization & Testing SC Materials Science GA XB996 UT WOS:A1997XB99600003 ER PT J AU McCready, DE Balmer, ML Keefer, KD AF McCready, DE Balmer, ML Keefer, KD TI Experimental and calculated X-ray powder diffraction data for cesium titanium silicate, CsTiSi2O6.5: A new zeolite SO POWDER DIFFRACTION LA English DT Article DE x-ray powder diffraction; structure model; cesium titanium silicate; zeolite; pollucite AB Standardized experimental and calculated X-ray powder diffraction data for a new synthetic zeolite, cesium titanium silicate, CsTiSi2O6.5, are reported. In addition, a structure model in space group Ia(3)d (230), which is isomorphous with the mineral pollucite (CsAlSi2O6 . xH(2)O), is proposed for CsTiSi2O6.5. This structure model is the basis of the reported calculated X-ray powder diffraction data for CsTiSi2O6.5. The experimental pattern for CsTiSi2O6.5 shows this compound crystallizes in a body-centered cubic (BCC) unit cell with a = 13.8423 (1) Angstrom. The measured value of the reference intensity ratio (I/Ic) of CsTiSi2O6.5 is 2.37, while the contrasting calculated value of I/Ic is 4.45. The experimental density (D-m) of CsTiSi2O6.5 is 3.48 +/- 0.09 g/cm(3), in agreement with the calculated density (D-x) of 3.42 g/cm(3). Chemical analysis of CsTiSi2O6.5 by atomic absorption spectroscopy gives its composition as 54 +/- 2 wt% Cs; 23 +/- 2 wt% Ti; 23 +/- 2 wt% Si, which compares favorably with the theoretical composition of 56 wt% Cs; 20 wt% Ti; 24 wt% Si. (C) 1997 International Centre for Diffraction Data. RP McCready, DE (reprint author), PACIFIC NW LAB, POB 999, RICHLAND, WA 99352 USA. NR 9 TC 16 Z9 16 U1 0 U2 2 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0885-7156 J9 POWDER DIFFR JI Powder Diffr. PD MAR PY 1997 VL 12 IS 1 BP 40 EP 46 PG 7 WC Materials Science, Characterization & Testing SC Materials Science GA XB996 UT WOS:A1997XB99600009 ER PT J AU Huilin, L Gidaspow, D Bouillard, JX AF Huilin, L Gidaspow, D Bouillard, JX TI Dimension measurements of hydrodynamic attractors in circulating fluidized beds SO POWDER TECHNOLOGY LA English DT Article DE circulating beds; fluidized beds; hydrodynamic attractors; deterministic chaos analysis ID GAS-SOLID FLOW; GRANULAR FLOW; PARTICLES; TUBES; PIPE AB Experimental measurements of the correlation dimension, Kolmogorov entropy, and Lyapunov exponent of circulating fluidized bed (CFB) chaotic attractors were obtained by recording differential pressure and gamma-ray porosity time series along the height of a cold experimental CFB operating with 75 mu m diameter fluid catalytic cracking (FCC) catalyst. The attractor dimension did not vary with respect to the type of measurement taken. Both differential pressure and localized gamma-ray densitometry measurements showed the existence of a low order hydrodynamic attractor, whose dimension varied between 1.5 and 2.0 over the range of gas velocities and solids fluxes studied. Differential pressure measurements indicated that the attractor dimension decreased slightly in the lower section of the CFB and at higher solids fluxes. Localized radial gamma-ray bed porosity measurements indicate that the attractor dimension did not significantly vary across the bed cross-section but did show a tendency to be slightly lower near the riser wall. C1 ARGONNE NATL LAB,ARGONNE,IL 60439. RP Huilin, L (reprint author), IIT,10 W 33RD ST,CHICAGO,IL 60616, USA. RI Lu, Hui-Lin/N-9163-2013 OI Lu, Hui-Lin/0000-0001-9951-5984 NR 31 TC 19 Z9 20 U1 0 U2 3 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0032-5910 J9 POWDER TECHNOL JI Powder Technol. PD MAR PY 1997 VL 90 IS 3 BP 179 EP 185 DI 10.1016/S0032-5910(96)03195-6 PG 7 WC Engineering, Chemical SC Engineering GA WU306 UT WOS:A1997WU30600001 ER PT J AU Fernandez, C Sainz, RD AF Fernandez, C Sainz, RD TI Pathways of protein degradation in L6 myotubes SO PROCEEDINGS OF THE SOCIETY FOR EXPERIMENTAL BIOLOGY AND MEDICINE LA English DT Article ID GROWTH-FACTOR-I; BETA-ADRENERGIC AGONIST; PRIMARY MUSCLE CULTURES; GENE-EXPRESSION; SATELLITE CELLS; SKELETAL-MUSCLE; L8 MYOTUBES; INSULIN; METABOLISM; TURNOVER AB To assess the importance of different proteolytic pathways in anabolic and catabolic states, L6 myotubes were labeled with H-3-phenylalanine for 24 hr, then exposed for another 24 hr to control medium, alone or with one of the following: insulin (1 mu/ml), insulin-like growth factor-l (IGF-I, 100 ng/ml), clenbuterol (100 mu M), or dexamethasone (1 mu M). Release of acid-soluble radioactivity and 3-methylhistidine were used to determine rates of total and myofibrillar protein degradation, respectively. Within each hormone treatment, cells were also exposed to none, one, or both of the following protease inhibitors: chloroquine (25 mu M); E-64d (100 mu M) Chloroquine inhibits lysosomal proteases, and E-64d is a cell-penetrating inhibitor of cysteine proteases (including the calpains). Total protein degradation was reduced by insulin (-33%) and IGF-I (-40%), increased by clenbuterol (+20%), and was unaffected by dexamethasone, Myofibrillar protein degradation was reduced by insulin (-35%), IGF-I (-55%), and clenbuterol (-22%), and was unaffected by dexamethasone. Therefore, total (mainly sarcoplasmic) and myofibrillar protein degradation were regulated independently of one another. The influence of the inhibitors was not consistent across hormone treatments. Chloroquine inhibited total but not myofibrillar proteolysis, indicating that lysosomes may be rate limiting in the former but not the latter. In contrast, E-64d had no effect on total protein degradation, but increased myofibrillar proteolysis. Interactions between anabolic and catabolic hormones and these two protease inhibitors indicate that both lysosomal and nonlysosomal proteolytic pathways are involved in regulation of total protein degradation in myotubes. In contrast, lysosomes are probably not involved in regulating the rate of myofibrillar protein degradation, the initial step likely being due to calpain activity. C1 LAWRENCE LIVERMORE NATL LAB,DEPT ANIM SCI,DAVIS,CA 95616. RI Fernandez, Carlos Javier/I-4027-2015 OI Fernandez, Carlos Javier/0000-0002-0368-0158 NR 26 TC 15 Z9 15 U1 0 U2 0 PU BLACKWELL SCIENCE INC PI MALDEN PA 350 MAIN ST, MALDEN, MA 02148 SN 0037-9727 J9 P SOC EXP BIOL MED JI Proc. Soc. Exp. Biol. Med. PD MAR PY 1997 VL 214 IS 3 BP 242 EP 247 PG 6 WC Medicine, Research & Experimental SC Research & Experimental Medicine GA WP948 UT WOS:A1997WP94800007 PM 9083257 ER PT J AU VanHove, MA Cerda, J Sautet, P Bocquet, ML Salmeron, M AF VanHove, MA Cerda, J Sautet, P Bocquet, ML Salmeron, M TI Surface structure determination by STM vs LEED SO PROGRESS IN SURFACE SCIENCE LA English DT Article; Proceedings Paper CT VIIth Symposium on Surface Physics CY JUN 30-JUL 04, 1996 CL TREST CASTLE, CZECH REPUBLIC SP Acad Sci Czech Republic, Inst Phys, Union Czech Mathematicians & Physicists, Phys Sect, Technol Fdn Czech Republic, Commiss European Communities, German Phys Soc ID SCANNING-TUNNELING-MICROSCOPY; THEORETICAL-ANALYSIS; TENSOR LEED; IMAGES; OXYGEN; SULFUR; PT(111); MO(100); ADSORBATES; AL(111) AB Scanning tunneling microscopy has been developed, among other applications, into a powerful surface structural tool. Over time, it has become more apparent that theoretical modeling of the STM image is often necessary to reliably extract atomic positions. We here review recent advances in this direction and illustrate with several examples that geometrical information is mixed not only with electronic structure information and corresponding tip properties, but also with tunneling effects like interference between multiple tunneling channels. C1 INST RECH CATALYSE,F-69626 VILLEURBANNE,FRANCE. ECOLE NORMALE SUPER LYON,F-69364 LYON 07,FRANCE. RP VanHove, MA (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV MAT SCI,BERKELEY,CA 94720, USA. RI Van Hove, Michel/A-9862-2008; BOCQUET, MARIE-LAURE/A-7810-2011; Cerda, Jorge/F-4043-2010; Sautet, Philippe/G-3710-2014 OI Van Hove, Michel/0000-0002-8898-6921; Cerda, Jorge/0000-0001-6176-0191; Sautet, Philippe/0000-0002-8444-3348 NR 50 TC 18 Z9 18 U1 2 U2 11 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0079-6816 J9 PROG SURF SCI JI Prog. Surf. Sci. PD MAR-APR PY 1997 VL 54 IS 3-4 BP 315 EP 329 PG 15 WC Chemistry, Physical; Physics, Condensed Matter SC Chemistry; Physics GA XE120 UT WOS:A1997XE12000008 ER PT J AU Fadley, CS Chen, Y Couch, RE Daimon, H Denecke, R Denlinger, JD Galloway, H Hussain, Z Kaduwela, AP Kim, YJ Len, PM Liesegang, J Menchero, J Morais, J Palomares, J Ruebush, SD Rotenberg, E Salmeron, MB Scalettar, R Schattke, W Singh, R Thevuthasan, S Tober, ED VanHove, MA Wang, Z Ynzunza, RX AF Fadley, CS Chen, Y Couch, RE Daimon, H Denecke, R Denlinger, JD Galloway, H Hussain, Z Kaduwela, AP Kim, YJ Len, PM Liesegang, J Menchero, J Morais, J Palomares, J Ruebush, SD Rotenberg, E Salmeron, MB Scalettar, R Schattke, W Singh, R Thevuthasan, S Tober, ED VanHove, MA Wang, Z Ynzunza, RX TI Diffraction and holography with photoelectrons and fluorescent x-rays SO PROGRESS IN SURFACE SCIENCE LA English DT Article; Proceedings Paper CT VIIth Symposium on Surface Physics CY JUN 30-JUL 04, 1996 CL TREST CASTLE, CZECH REPUBLIC SP Acad Sci Czech Republic, Inst Phys, Union Czech Mathematicians & Physicists, Phys Sect, Technol Fdn Czech Republic, Commiss European Communities, German Phys Soc ID ELECTRON-EMISSION HOLOGRAPHY; CORE-LEVEL PHOTOEMISSION; ANGULAR-RESOLVED PHOTOEMISSION; METAL-METAL INTERFACES; BULK CURIE-TEMPERATURE; MAGNETIC DICHROISM; AUGER-ELECTRON; MULTIPLE-SCATTERING; CIRCULAR-DICHROISM; ATOMIC-RESOLUTION AB We consider studies of the atomic and magnetic structure near surfaces by photoelectron diffraction and by the holographic inversion of both photoelectron diffraction data and diffraction data involving the emission of fluorescent x-rays. The current status of photoelectron diffraction studies of surfaces, interfaces, and other nanostructures is first briefly reviewed, and then several recent developments and proposals for future areas of application are discussed. The application of full-solid-angle diffraction data, together with simultaneous characterization by low energy electron diffraction and scanning tunneling microscopy, to the epitaxial growth of oxides and metals is considered. Several new avenues that are being opened up by third-generation synchrotron radiation sources are also discussed. These include site-resolved photoelectron diffraction from surface and interface atoms, the possibility of time-resolved measurements of surface reactions with chemical-state resolution, and circular dichroism in photoelectron angular distributions from both nonmagnetic and magnetic systems. The addition of spin to the photoelectron diffraction measurement is also considered as a method for studying short-range magnetic order, including the measurement of surface magnetic phase transitions. This spin sensitivity can be achieved through either core-level multiplet splittings or circular-polarized excitation of spin-orbit-split levels. The direct imaging of short-range atomic structure by both photoelectron holography and two distinct types of x-ray holography involving fluorescent emission is also discussed. Both photoelectron and x-ray holography have demonstrated the ability to directly determine at least approximate atomic structures in three dimensions. Photoelectron holography with spin resolution may make it possible also to study short-range magnetic order in a holographic fashion. Although much more recent in its first experimental demonstrations, x-ray fluorescence holography should permit deriving more accurate atomic images for a variety of materials, including both surface and bulk regions. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV MAT SCI,BERKELEY,CA 94720. UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,ADV LIGHT SOURCE,BERKELEY,CA 94720. UNIV CALIF BERKELEY,DEPT PHYS,BERKELEY,CA 94720. UNIV HAWAII,DEPT CHEM,HONOLULU,HI 96822. OSAKA UNIV,DEPT MAT PHYS,TOYONAKA,OSAKA 560,JAPAN. UNIV WISCONSIN,MILWAUKEE,WI 53201. UNIV OREGON,EUGENE,OR 97403. CHRISTIAN ALBRECHTS UNIV KIEL,INST THEORET PHYS,D-24118 KIEL,GERMANY. LA TROBE UNIV,DEPT PHYS,BUNDOORA,VIC 3083,AUSTRALIA. RP Fadley, CS (reprint author), UNIV CALIF DAVIS,DEPT PHYS,DAVIS,CA 95616, USA. RI Rotenberg, Eli/B-3700-2009; Van Hove, Michel/A-9862-2008; Palomares, Francisco Javier/C-4605-2011; Morais, Jonder/E-5022-2013; Register, CMSS/G-7191-2015; OI Rotenberg, Eli/0000-0002-3979-8844; Van Hove, Michel/0000-0002-8898-6921; Palomares, Francisco Javier/0000-0002-4768-2219; Morais, Jonder/0000-0002-4143-1208; Kaduwela, Ajith/0000-0002-7236-2698 NR 169 TC 52 Z9 54 U1 1 U2 11 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0079-6816 J9 PROG SURF SCI JI Prog. Surf. Sci. PD MAR-APR PY 1997 VL 54 IS 3-4 BP 341 EP 386 DI 10.1016/S0079-6816(97)00013-0 PG 46 WC Chemistry, Physical; Physics, Condensed Matter SC Chemistry; Physics GA XE120 UT WOS:A1997XE12000010 ER PT J AU Howell, RW Goddu, SM Narra, VR Fisher, DR Schenter, RE Rao, DV AF Howell, RW Goddu, SM Narra, VR Fisher, DR Schenter, RE Rao, DV TI Radiotoxicity of gadolinium-148 and radium-223 in mouse testes: Relative biological effectiveness of alpha-particle emitters in vivo SO RADIATION RESEARCH LA English DT Article ID MAMMALIAN-CELLS; IRRADIATION; DOSIMETRY; RADIATION; ENERGY; INVIVO; RADIOPHARMACEUTICALS; RADIONUCLIDES; INACTIVATION; RADIOBIOLOGY AB The biological effects of radionuclides that emit or particles are of considerable interest in view of their potential for therapy and their presence in the environment, The present work is a continuation of our ongoing effort to study the radiotoxicity of alpha-particle emitters in vivo using the survival of murine testicular sperm heads as the biological end point. Specifically, the relative biological effectiveness (RBE) of very low-energy or particles (3.2 MeV) emitted by Gd-148 is investigated and determined to be 7.4 +/- 2.4 when compared to the effects of acute external 120 kVp X rays. This datum, in conjunction with our earlier results for Po-210 and Pb-212 in equilibrium with its daughters, is used to revise and extend the range of validity of our previous RBE-energy relationship for a: particles emitted by tissue-incorporated radionuclides. The new empirical relationship is given by RBE, = 9.14 - 0.510 E(alpha), where 3 < E(alpha) < 9 MeV. The validity of this empirical relationship is tested by determining the RBE of the prolific a-particle emitter Ra-223 (in equilibrium with its daughters) experimentally in the same biological model and comparing the value obtained experimentally with the predicted value. The resulting RBE values are 5.4 +/- 0.9 and 5.6, respectively. This close agreement strongly supports the adequacy of the empirical RBE-E, relationship to predict the biological effects of alpha-particle emitters in vivo. (C) 1997 by Radiation Society. C1 PACIFIC NW LAB, RICHLAND, WA 99352 USA. RP Howell, RW (reprint author), UNIV MED & DENT NEW JERSEY, NEW JERSEY MED SCH, DEPT RADIOL, 185 S ORANGE AVE, NEWARK, NJ 07103 USA. FU NCI NIH HHS [R29 CA054891, R29 CA054891-05] NR 42 TC 34 Z9 37 U1 0 U2 1 PU RADIATION RESEARCH SOC PI OAK BROOK PA 2021 SPRING RD, STE 600, OAK BROOK, IL 60521 SN 0033-7587 J9 RADIAT RES JI Radiat. Res. PD MAR PY 1997 VL 147 IS 3 BP 342 EP 348 DI 10.2307/3579342 PG 7 WC Biology; Biophysics; Radiology, Nuclear Medicine & Medical Imaging SC Life Sciences & Biomedicine - Other Topics; Biophysics; Radiology, Nuclear Medicine & Medical Imaging GA WL732 UT WOS:A1997WL73200010 PM 9052681 ER PT J AU Fitzgerald, TJ Argo, PE Carlos, RC AF Fitzgerald, TJ Argo, PE Carlos, RC TI Effects of artificially modified ionospheres on HF propagation: Negative ion cation release experiment 2 and CRRES coqui experiments SO RADIO SCIENCE LA English DT Article ID PLASMA AB We report the results of measurements obtained in conjunction with a series of high-altitude chemical release experiments of effects of artificially modified ionospheres upon high-frequency, ionospherically reflected radio paths. Computer simulations indicate that under optimum conditions, ionospheric modifications induced by chemical releases could perturb or even disrupt a communication channel; our experiments corroborate this but also indicate that it is very difficult to actualize such disruptions. Our experiments have shown that an ionospheric depletion, in which the electron density hole forms a huge radio frequency lens, generates new modes which, however, do not significantly affect a communications system. Under optimum path geometry a signal strength decrease of 10 dB or more is possible for several tens of minutes. Enhancements, such as those produced by barium releases, act as reflecting mirrors that can create a large shadow zone on the ground and block off significant amounts of energy. We measured signal strength decreases of up to 20 dB. RP Fitzgerald, TJ (reprint author), LOS ALAMOS NATL LAB,MS D466,LOS ALAMOS,NM 87545, USA. NR 16 TC 3 Z9 3 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0048-6604 J9 RADIO SCI JI Radio Sci. PD MAR-APR PY 1997 VL 32 IS 2 BP 579 EP 591 DI 10.1029/96RS03597 PG 13 WC Astronomy & Astrophysics; Geochemistry & Geophysics; Meteorology & Atmospheric Sciences; Remote Sensing; Telecommunications SC Astronomy & Astrophysics; Geochemistry & Geophysics; Meteorology & Atmospheric Sciences; Remote Sensing; Telecommunications GA WP942 UT WOS:A1997WP94200022 ER PT J AU Lawrence, JD Gallagher, JM AF Lawrence, JD Gallagher, JM TI A proposal for performing software safety hazard analysis SO RELIABILITY ENGINEERING & SYSTEM SAFETY LA English DT Article ID FAULT-TREES AB Techniques for analyzing the safety and reliability of analog-based electronic protection systems that serve to mitigate hazards in process control systems have been developed over many years, and are reasonably understood. An example is the protection system in a nuclear power plant. The extension of these techniques to systems which include digital computers is not well developed, and there is little consensus among software engineering experts and safety experts on how to analyze such systems. One possible technique is to extend hazard analysis to include digital computer-based systems. Software is frequently overlooked during system hazard analyses, but this is unacceptable when the software is in control of a potentially hazardous operation. In such cases, hazard analysis should be extended to fully cover the software. A method for performing software hazard analysis is proposed in this paper. The method concentrates on finding hazards during the early stages of the software Life cycle, using an extension of HAZOP. (C) 1997 Elsevier Science Limited. C1 US NUCL REGULATORY COMMISS, OFF NUCL REACTOR REGULAT, WASHINGTON, DC 20555 USA. RP Lawrence, JD (reprint author), LAWRENCE LIVERMORE NATL LAB, FISS ENERGY & SYST SAFETY PROGRAM, POB 808, LIVERMORE, CA 94551 USA. NR 28 TC 8 Z9 9 U1 0 U2 0 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0951-8320 J9 RELIAB ENG SYST SAFE JI Reliab. Eng. Syst. Saf. PD MAR PY 1997 VL 55 IS 3 BP 267 EP 282 DI 10.1016/S0951-8320(96)00098-1 PG 16 WC Engineering, Industrial; Operations Research & Management Science SC Engineering; Operations Research & Management Science GA WQ932 UT WOS:A1997WQ93200010 ER PT J AU Gao, W Lesht, BM AF Gao, W Lesht, BM TI Model inversion of satellite-measured reflectances for obtaining surface biophysical and bidirectional reflectance characteristics of grassland SO REMOTE SENSING OF ENVIRONMENT LA English DT Article ID CANOPY AB An inversion method that can be used to derive information about biophysical and radiative conditions of a grassland surface from remotely sensed surface spectral reflectances is described. A previously developed simple surface bidirectional reflectance model was expanded for use in this inversion process. In the inversion process, a multidimensional optimization scheme is used to obtain a set of model parameters that minimizes the difference between modeled and observed reflectances. The effect of the slumber of data points used in the inversion on the accuracy of the model inversion was investigated with ground based hemispheric scan measurements of surface spectral reflectances over a tallgrass prairie in Kansas. The result shows that the total inversion error consists of minimum or systematic error and ambiguity error The former result from uncertainties in the accuracies of the model and measurements, whereas the latter is caused by the ambiguity of the model inversion when a limited number of data points are used The systematic error is independent of the number of data points, whereas the ambiguity error decreases sharply with increasing data points when the num ber of data points is small (fewer than about seven). An inversion method with appropriate data grouping applied to the reflectance data from the Advanced Very High Resolution Radiometer is shown to improve estimates of surface parameters over the grassland site. Relative differences between measured surface bidirectional reflectances and those calculated with the derived surface parameters range from 6% to 15% (12.9% for band 1 [0.65-0.67 mu m] 6.9% for band 2 [0.81-0.84 mu m] and 7.6% for band 3 [1.62-1.69 mu m]). (C)Elsevier Science Inc., 1997. RP Gao, W (reprint author), ARGONNE NATL LAB,DIV ENVIRONM RES,ARGONNE,IL 60439, USA. NR 20 TC 17 Z9 20 U1 0 U2 2 PU ELSEVIER SCIENCE INC PI NEW YORK PA 655 AVENUE OF THE AMERICAS, NEW YORK, NY 10010 SN 0034-4257 J9 REMOTE SENS ENVIRON JI Remote Sens. Environ. PD MAR PY 1997 VL 59 IS 3 BP 461 EP 471 DI 10.1016/S0034-4257(96)00115-0 PG 11 WC Environmental Sciences; Remote Sensing; Imaging Science & Photographic Technology SC Environmental Sciences & Ecology; Remote Sensing; Imaging Science & Photographic Technology GA WQ411 UT WOS:A1997WQ41100005 ER PT J AU Vine, MF Setzer, RW Everson, RB Wyrobek, AJ AF Vine, MF Setzer, RW Everson, RB Wyrobek, AJ TI Human sperm morphometry and smoking, caffeine, and alcohol consumption SO REPRODUCTIVE TOXICOLOGY LA English DT Article DE sperm; morphology; computerized image analysis; smoking; male; human ID SEMEN QUALITY; CIGARETTE-SMOKING; MEN; CLASSIFICATION; SPERMATOZOA; MORPHOLOGY; EXPOSURE; COTININE; COUPLES; BLOOD AB The purpose of this study is to determine whether sperm nuclear size, shape, and chromatin texture parameters are associated with lifestyle exposures including smoking, caffeine, and alcohol consumption. Eighty-six healthy male volunteers (ages 18-35), recruited through newspaper advertisements, provided a semen, blood, and urine sample and completed a questionnaire concerning demographic and lifestyle exposures. Sperm nuclear size, shape, and chromatin texture parameters were measured using computerized image analysis. Results indicated no associations between the sperm nuclear morphometric parameters and age, smoking, or alcohol consumption. There was weak evidence for an association with caffeine intake. In conclusion, the lifestyle factors smoking, caffeine intake, and alcohol consumption do not appear to significantly affect sperm nuclear size, shape, or chromatin texture in this study population. (C) 1997 Elsevier Science Inc. C1 US EPA,HLTH EFFECTS RES LAB,RES TRIANGLE PK,NC 27711. LAWRENCE LIVERMORE NATL LAB,DIV BIOMED SCI,LIVERMORE,CA 94550. RP Vine, MF (reprint author), UNIV N CAROLINA,DEPT EPIDEMIOL,CB 7400,CHAPEL HILL,NC 27599, USA. NR 37 TC 21 Z9 23 U1 0 U2 3 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0890-6238 J9 REPROD TOXICOL JI Reprod. Toxicol. PD MAR-JUN PY 1997 VL 11 IS 2-3 BP 179 EP 184 DI 10.1016/S0890-6238(97)00004-X PG 6 WC Reproductive Biology; Toxicology SC Reproductive Biology; Toxicology GA WQ840 UT WOS:A1997WQ84000002 PM 9100290 ER PT J AU Savitz, DA Bornschein, RL Amler, RW Bove, FI Edmonds, LD Hanson, JW Kaye, WE Khoury, M Kiely, M Lemasters, GK Sever, LE Shepard, TH Spengler, RF Steinberg, KK YearginAllsopp, M AF Savitz, DA Bornschein, RL Amler, RW Bove, FI Edmonds, LD Hanson, JW Kaye, WE Khoury, M Kiely, M Lemasters, GK Sever, LE Shepard, TH Spengler, RF Steinberg, KK YearginAllsopp, M TI Assessment of reproductive disorders and birth defects in communities near hazardous chemical sites .1. Birth defects and developmental disorders SO REPRODUCTIVE TOXICOLOGY LA English DT Article ID ABORTIONS AB Members of the workgroup on birth defects and developmental disorders discussed methods to assess structural anomalies, genetic changes and mutations, fetal and infant mortality, functional deficits, and impaired fetal and neonatal growth. Tier 1 assessments for all five adverse reproductive outcomes consist of questionnaires and reviews of medical records rather than laboratory testing of biologic specimens, The workgroup members noted a role for neurodevelopmental testing and for limited genetic studies, such as karyotyping in Tier 2 assessments, Emerging methodologies to identify chromosomal aberrations, DNA adducts, and repair inhibition were reserved for Tier 3. (C) 1997 Elsevier Science Inc. C1 UNIV N CAROLINA,CHAPEL HILL,NC 27515. UNIV CINCINNATI,CINCINNATI,OH 45221. AGCY TOX SUBST & DIS REGISTRY,ATLANTA,GA. CTR DIS CONTROL & PREVENT,ATLANTA,GA. UNIV IOWA,IOWA CITY,IA 52242. US HLTH RESOURCES & SERV ADM,PUBL HLTH SERV,ROCKVILLE,MD 20857. BATTELLE SEATTLE RES CTR,SEATTLE,WA. UNIV WASHINGTON,SEATTLE,WA 98195. NR 20 TC 9 Z9 9 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0890-6238 J9 REPROD TOXICOL JI Reprod. Toxicol. PD MAR-JUN PY 1997 VL 11 IS 2-3 BP 223 EP 230 DI 10.1016/S0890-6238(96)00106-2 PG 8 WC Reproductive Biology; Toxicology SC Reproductive Biology; Toxicology GA WQ840 UT WOS:A1997WQ84000009 PM 9100297 ER PT J AU Wyrobek, AJ Schrader, SM Perreault, SD Fenster, L Huszar, G Katz, DF Osorio, AM Sublet, V Evenson, D AF Wyrobek, AJ Schrader, SM Perreault, SD Fenster, L Huszar, G Katz, DF Osorio, AM Sublet, V Evenson, D TI Assessment of reproductive disorders and birth defects in communities near hazardous chemical sites .3. Guidelines for field studies of male reproductive disorders SO REPRODUCTIVE TOXICOLOGY LA English DT Article ID SEMIAUTOMATIC IMAGE-ANALYSIS; CREATINE-KINASE ACTIVITY; HUMAN-SPERM MORPHOLOGY; HUMAN-SPERMATOZOA; CHROMATIN STRUCTURE; OCCUPATIONAL HAZARDS; ETHYLENE DIBROMIDE; OLIGOSPERMIC MEN; FLOW-CYTOMETRY; SEMEN ANALYSIS AB Exposures to environmental toxicants can have detrimental effects on several aspects of human male reproduction: fertility, sexual function, hormone status, and pregnancy/birth outcomes. However, no simple prescreening methods are available for reliably identifying potential hazards; questionnaires alone are relatively imprecise and inefficient in the absence of field data. Multidisciplinary field studies are required that include detailed exposure information, health and reproductive histories, physical examinations, semen analyses, and possibly, hormone analyses. Semen analysis is a critical component of field studies for evaluating two aspects of male reproduction: 1) changes in sperm or seminal content, which may be indicative of adverse effects on the male reproductive system with possible implications for fertility potential; and 2) defects in sperm DNA or chromosomes, which may be associated with subsequent changes in viability during embryonic development and health risks to the offspring. Semen analyses may be tiered: 1) initially, each semen study may include conventional semen assays (concentration, motility, and morphology) as well as specific biomarkers indicated by the health effect of concern in the study cohort; and 2) archived samples (i.e., frozen, videotaped, or smeared) mag be utilized in later second-tier analyses to further characterize specific findings. Before initiating any field study, it is cost effective to critically evaluate the suitability of the cohort by confirming exposure and determining that there are adequate numbers of male participants in each exposure category. Such evaluations must be based on the statistical sensitivities of the specific tissue biomarkers and health endpoints for detecting changes. This article summarizes the components of the ideal field study and identifies research needs for improving field studies of mate effects and for understanding the mechanisms of male reproductive toxicity. Several promising semen methods currently under development are also discussed. (C) 1997 Elsevier Science Inc. C1 NIOSH,ROBERT A TAFT LABS,CINCINNATI,OH 45226. US EPA,NATL HLTH & ENVIRONM EFFECTS RES LAB,REPROD TOXICOL DIV,RES TRIANGLE PK,NC 27711. DEPT HLTH SERV,REPROD EPIDEMIOL SECT,BERKELEY,CA. YALE UNIV,SCH MED,DEPT OBSTET & GYNECOL,NEW HAVEN,CT 06510. DUKE UNIV,DEPT BIOMED ENGN,DURHAM,NC 27706. DEPT HLTH SERV,BERKELEY,CA. SUBLET & ASSOCIATES,COLUMBUS,OH. S DAKOTA STATE UNIV,OLSON BIOCHEM FLOW CYTOMETRY LAB,BROOKINGS,SD 57007. RP Wyrobek, AJ (reprint author), LAWRENCE LIVERMORE NATL LAB,BIOL & BIOTECHNOL RES PROGRAM,L-452,POB 808,7000 EAST AVE,LIVERMORE,CA 94550, USA. RI Schrader, Steven/E-8120-2011 FU NIEHS NIH HHS [Y01-ES-10203-00] NR 72 TC 39 Z9 44 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0890-6238 J9 REPROD TOXICOL JI Reprod. Toxicol. PD MAR-JUN PY 1997 VL 11 IS 2-3 BP 243 EP 259 DI 10.1016/S0890-6238(96)00108-6 PG 17 WC Reproductive Biology; Toxicology SC Reproductive Biology; Toxicology GA WQ840 UT WOS:A1997WQ84000011 PM 9100299 ER PT J AU Woychik, R Hogan, B Bryant, S Eichele, G Kimelman, D Noden, D Schoenwolf, G Wright, C AF Woychik, R Hogan, B Bryant, S Eichele, G Kimelman, D Noden, D Schoenwolf, G Wright, C TI Pattern formation SO REPRODUCTIVE TOXICOLOGY LA English DT Article ID CHICK WING BUD; EMBRYONAL CARCINOMA-CELLS; RETINOIC ACID SYNTHESIS; POLARIZING ACTIVITY; SONIC-HEDGEHOG; DEVELOPMENTAL DEFECTS; TARGETED DISRUPTION; NUCLEAR RECEPTORS; LOCAL APPLICATION; THYROID-HORMONE C1 VANDERBILT UNIV,SCH MED,DEPT CELL BIOL,NASHVILLE,TN 37212. UNIV CALIF IRVINE,CTR DEV BIOL,IRVINE,CA 92717. BAYLOR COLL MED,DEPT BIOCHEM,HOUSTON,TX 77030. UNIV WASHINGTON,DEPT BIOCHEM,SEATTLE,WA 98195. CORNELL UNIV,COLL VET MED,DEPT ANAT,ITHACA,NY 14853. UNIV UTAH,SCH MED,DEPT ANAT & NEUROBIOL,SALT LAKE CITY,UT. RP Woychik, R (reprint author), OAK RIDGE NATL LAB,DIV BIOL,MAMMALIAN GENET & DEV SECT,POB 2009,OAK RIDGE,TN 37831, USA. NR 43 TC 0 Z9 0 U1 0 U2 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0890-6238 J9 REPROD TOXICOL JI Reprod. Toxicol. PD MAR-JUN PY 1997 VL 11 IS 2-3 BP 339 EP 344 DI 10.1016/S0890-6238(96)00217-1 PG 6 WC Reproductive Biology; Toxicology SC Reproductive Biology; Toxicology GA WQ840 UT WOS:A1997WQ84000025 PM 9100309 ER PT J AU Culiat, CT Carver, EA Walkowicz, M Rinchik, EM Cacheiro, NLA Russell, LB Generoso, WM Stubbs, L AF Culiat, CT Carver, EA Walkowicz, M Rinchik, EM Cacheiro, NLA Russell, LB Generoso, WM Stubbs, L TI Induced mouse chromosomal rearrangements as tools for identifying critical developmental genes and pathways SO REPRODUCTIVE TOXICOLOGY LA English DT Article DE chromosome rearrangements; gene mapping and cloning; mouse developmental mutations ID CLEFT-PALATE SUSCEPTIBILITY; AMINOBUTYRIC-ACID RECEPTOR; DILUTION P LOCUS; ENVIRONMENT INTERACTION; BALANCED TRANSLOCATION; POSITIONAL CLONING; BIRTH-DEFECTS; MICE; IDENTIFICATION; CANDIDATE AB Due to the rapid advances that have been made in molecular and genetic technology during the past decade, the genes associated with a large number of human hereditary diseases have been isolated and analyzed in detail. These cloned genes provide new tools for research geared toward a better understanding of normal human development, and also of the many ways that basic, essential morphologic pathways can be disturbed, Chromosomal rearrangements, especially deletions and translocations, have been especially beneficial in the mapping and isolation of human disease genes because of their visibility on both the cytogenetic and molecular levels, However, these useful types of mutations occur with low frequency in the human population Chromosomal rearrangements can be induced relatively easily in mice, and several large, independent collections of translocation and deletion mutants have been generated in the course of risk-assessment and mutagenesis studies over the past several decades, Combined with new molecular technologies, these collections of mutant animals provide a means of gaining ready access to genes associated with developmental defects including craniofacial abnormalities, hydrocephaly, skeletal deformities, and complex neurologic disorders, As an illustration of this approach, we briefly review our progress in the study of three mutations associated with defects in palate development, juvenile growth, fitness and sterility, and neurologic development in mice, respectively. (C) 1997 Elsevier Science Inc. C1 OAK RIDGE NATL LAB,DIV BIOL,OAK RIDGE,TN 37831. SARAH LAWRENCE COLL,BRONXVILLE,NY 10708. OI Stubbs, Lisa/0000-0002-9556-1972 NR 58 TC 4 Z9 4 U1 0 U2 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0890-6238 J9 REPROD TOXICOL JI Reprod. Toxicol. PD MAR-JUN PY 1997 VL 11 IS 2-3 BP 345 EP 351 DI 10.1016/S0890-6238(96)00147-5 PG 7 WC Reproductive Biology; Toxicology SC Reproductive Biology; Toxicology GA WQ840 UT WOS:A1997WQ84000026 PM 9100310 ER EF