FN Thomson Reuters Web of Science™ VR 1.0 PT J AU VANLERBERGHE, GC MCINTOSH, L AF VANLERBERGHE, GC MCINTOSH, L TI MANIPULATION OF PLANT MITOCHONDRIAL ELECTRON-TRANSPORT SO PLANT PHYSIOLOGY LA English DT Meeting Abstract C1 MICHIGAN STATE UNIV,DOE,PLANT RES LAB,E LANSING,MI 48824. MICHIGAN STATE UNIV,DEPT BIOCHEM,E LANSING,MI 48824. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER SOC PLANT PHYSIOLOGISTS PI ROCKVILLE PA 15501 MONONA DRIVE, ROCKVILLE, MD 20855 SN 0032-0889 J9 PLANT PHYSIOL JI Plant Physiol. PD MAY PY 1993 VL 102 IS 1 SU S BP 128 EP 128 PG 1 WC Plant Sciences SC Plant Sciences GA LD890 UT WOS:A1993LD89000729 ER PT J AU CHEN, RJ SILVER, D SZCZYGLOWSKI, K DEBRUIJN, FJ AF CHEN, RJ SILVER, D SZCZYGLOWSKI, K DEBRUIJN, FJ TI TISSUE-SPECIFIC AND CYTOKININ-INDUCED EXPRESSION OF THE SESBANIA-ROSTRATA EARLY NODULIN SRENOD2 GENE SO PLANT PHYSIOLOGY LA English DT Meeting Abstract C1 MICHIGAN STATE UNIV,DOE,PLANT RES LAB,E LANSING,MI 48824. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER SOC PLANT PHYSIOLOGISTS PI ROCKVILLE PA 15501 MONONA DRIVE, ROCKVILLE, MD 20855 SN 0032-0889 J9 PLANT PHYSIOL JI Plant Physiol. PD MAY PY 1993 VL 102 IS 1 SU S BP 129 EP 129 PG 1 WC Plant Sciences SC Plant Sciences GA LD890 UT WOS:A1993LD89000734 ER PT J AU NIE, GY LONG, SP WEBBER, A AF NIE, GY LONG, SP WEBBER, A TI THE EFFECT OF NITROGEN SUPPLY ON DOWN-REGULATION OF PHOTOSYNTHESIS IN SPRING WHEAT GROWN IN AN ELEVATED CO2 CONCENTRATION SO PLANT PHYSIOLOGY LA English DT Meeting Abstract C1 BROOKHAVEN NATL LAB,DEPT APPL SCI,DIV BIOSYST & PROC SCI,UPTON,NY 11973. UNIV ESSEX,DEPT BIOL,COLCHESTER CO4 3SQ,ESSEX,ENGLAND. ARIZONA STATE UNIV,DEPT BOT,TEMPE,AZ 85284. ARIZONA STATE UNIV,CTR STUDY EARLY EVENTS PHOTOSYNTHESIS,TEMPE,AZ 85284. RI Long, Stephen/A-2488-2008 OI Long, Stephen/0000-0002-8501-7164 NR 0 TC 2 Z9 3 U1 0 U2 3 PU AMER SOC PLANT PHYSIOLOGISTS PI ROCKVILLE PA 15501 MONONA DRIVE, ROCKVILLE, MD 20855 SN 0032-0889 J9 PLANT PHYSIOL JI Plant Physiol. PD MAY PY 1993 VL 102 IS 1 SU S BP 138 EP 138 PG 1 WC Plant Sciences SC Plant Sciences GA LD890 UT WOS:A1993LD89000787 ER PT J AU SZCZYGLOWSKI, K FUJIMOTO, S SZABADOS, L SILVER, D DEBRUIJN, FJ AF SZCZYGLOWSKI, K FUJIMOTO, S SZABADOS, L SILVER, D DEBRUIJN, FJ TI SITE-SPECIFIC MUTAGENESIS OF THE NODULE-INFECTED-CELL-EXPRESSION (NICE) ELEMENT OF THE SESBANIA-ROSTRATA LEGHEMOGLOBIN GLB3 PROMOTER SO PLANT PHYSIOLOGY LA English DT Meeting Abstract C1 MICHIGAN STATE UNIV,MSU DOE,PLANT RES LAB,E LANSING,MI 48824. RI Szabados, Laszlo/F-2078-2010 NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER SOC PLANT PHYSIOLOGISTS PI ROCKVILLE PA 15501 MONONA DRIVE, ROCKVILLE, MD 20855 SN 0032-0889 J9 PLANT PHYSIOL JI Plant Physiol. PD MAY PY 1993 VL 102 IS 1 SU S BP 153 EP 153 PG 1 WC Plant Sciences SC Plant Sciences GA LD890 UT WOS:A1993LD89000879 ER PT J AU TSCHAPLINSKI, T TUSKAN, G AF TSCHAPLINSKI, T TUSKAN, G TI WATER-STRESS TOLERANCE OF BLACK COTTONWOOD AND EASTERN COTTONWOOD AND 4 OF THEIR HYBRID PROGENY SO PLANT PHYSIOLOGY LA English DT Meeting Abstract C1 OAK RIDGE NATL LAB,DIV ENVIRONM SCI,OAK RIDGE,TN 37831. RI Tuskan, Gerald/A-6225-2011 OI Tuskan, Gerald/0000-0003-0106-1289 NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER SOC PLANT PHYSIOLOGISTS PI ROCKVILLE PA 15501 MONONA DRIVE, ROCKVILLE, MD 20855 SN 0032-0889 J9 PLANT PHYSIOL JI Plant Physiol. PD MAY PY 1993 VL 102 IS 1 SU S BP 157 EP 157 PG 1 WC Plant Sciences SC Plant Sciences GA LD890 UT WOS:A1993LD89000901 ER PT J AU RHODES, D YANG, WJ SAMARAS, Y WOOD, KV BONHAM, CC RHODES, JC BURR, B AF RHODES, D YANG, WJ SAMARAS, Y WOOD, KV BONHAM, CC RHODES, JC BURR, B TI MAP LOCATIONS OF GENES CONFERRING GLYCINEBETAINE AND TRIGONELLINE ACCUMULATION IN MAIZE SO PLANT PHYSIOLOGY LA English DT Meeting Abstract C1 PURDUE UNIV,DEPT HORT,W LAFAYETTE,IN 47907. PURDUE UNIV,DEPT CHEM,W LAFAYETTE,IN 47907. PURDUE UNIV,DEPT BIOCHEM,W LAFAYETTE,IN 47907. BROOKHAVEN NATL LAB,DEPT BIOL,UPTON,NY 11973. NR 0 TC 3 Z9 3 U1 0 U2 0 PU AMER SOC PLANT PHYSIOLOGISTS PI ROCKVILLE PA 15501 MONONA DRIVE, ROCKVILLE, MD 20855 SN 0032-0889 J9 PLANT PHYSIOL JI Plant Physiol. PD MAY PY 1993 VL 102 IS 1 SU S BP 160 EP 160 PG 1 WC Plant Sciences SC Plant Sciences GA LD890 UT WOS:A1993LD89000919 ER PT J AU HANSON, PJ SAMUELSON, LJ WULLSCHLEGER, SD EDWARDS, GS AF HANSON, PJ SAMUELSON, LJ WULLSCHLEGER, SD EDWARDS, GS TI IMPACTS OF OZONE ON PHOTOSYNTHESIS AND CONDUCTANCE OF TREE VERSUS SEEDLING QUERCUS-RUBRA L FOLIAGE SO PLANT PHYSIOLOGY LA English DT Meeting Abstract C1 OAK RIDGE NATL LAB,DIV ENVIRONM SCI,OAK RIDGE,TN 37831. TENNESSEE VALLEY AUTHOR,NORRIS,TN 37828. RI Hanson, Paul J./D-8069-2011; Wullschleger, Stan/B-8297-2012 OI Hanson, Paul J./0000-0001-7293-3561; Wullschleger, Stan/0000-0002-9869-0446 NR 0 TC 0 Z9 0 U1 0 U2 2 PU AMER SOC PLANT PHYSIOLOGISTS PI ROCKVILLE PA 15501 MONONA DRIVE, ROCKVILLE, MD 20855 SN 0032-0889 J9 PLANT PHYSIOL JI Plant Physiol. PD MAY PY 1993 VL 102 IS 1 SU S BP 161 EP 161 PG 1 WC Plant Sciences SC Plant Sciences GA LD890 UT WOS:A1993LD89000928 ER PT J AU KNIGHT, TJ TEMPLE, S SENGUPTAGOPALAN, C LANGSTONUNKEFER, P AF KNIGHT, TJ TEMPLE, S SENGUPTAGOPALAN, C LANGSTONUNKEFER, P TI COORDINATED CHANGES IN THE ACTIVITIES OF SOME OAT ENZYMES INVOLVED IN NITROGEN AND CARBON METABOLISM SO PLANT PHYSIOLOGY LA English DT Meeting Abstract C1 NEW MEXICO STATE UNIV,LAS CRUCES,NM 88003. UNIV SO MAINE,PORTLAND,ME 04103. LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87544. NR 0 TC 1 Z9 1 U1 0 U2 0 PU AMER SOC PLANT PHYSIOLOGISTS PI ROCKVILLE PA 15501 MONONA DRIVE, ROCKVILLE, MD 20855 SN 0032-0889 J9 PLANT PHYSIOL JI Plant Physiol. PD MAY PY 1993 VL 102 IS 1 SU S BP 172 EP 172 PG 1 WC Plant Sciences SC Plant Sciences GA LD890 UT WOS:A1993LD89000992 ER PT J AU WHITE, RB WU, YL AF WHITE, RB WU, YL TI COLLISIONLESS TRANSPORT IN A STOCHASTIC MAGNETIC-FIELD SO PLASMA PHYSICS AND CONTROLLED FUSION LA English DT Article ID CHIRIKOV-TAYLOR MODEL; DIFFUSION; SYSTEMS; LINES AB Collisionless transport in stochastic magnetic field configuration is investigated numerically. Results are in reasonable agreement with analytic expressions valid well above stochastic threshold. RP WHITE, RB (reprint author), PRINCETON UNIV,PRINCETON PLASMA PHYS LAB,PRINCETON,NJ 08544, USA. RI White, Roscoe/D-1773-2013 OI White, Roscoe/0000-0002-4239-2685 NR 19 TC 21 Z9 21 U1 1 U2 7 PU IOP PUBLISHING LTD PI BRISTOL PA TECHNO HOUSE, REDCLIFFE WAY, BRISTOL, ENGLAND BS1 6NX SN 0741-3335 J9 PLASMA PHYS CONTR F JI Plasma Phys. Control. Fusion PD MAY PY 1993 VL 35 IS 5 BP 595 EP 599 DI 10.1088/0741-3335/35/5/005 PG 5 WC Physics, Fluids & Plasmas SC Physics GA LG961 UT WOS:A1993LG96100005 ER PT J AU FRILER, JB CEBE, P AF FRILER, JB CEBE, P TI DEVELOPMENT OF CRYSTALLINITY IN NEW-TPI POLYIMIDE SO POLYMER ENGINEERING AND SCIENCE LA English DT Article ID IMIDE-AMIDE COPOLYMERS; ETHER CONNECTING GROUPS; X-RAY-SCATTERING; AROMATIC POLYIMIDE; CRYSTALLIZATION BEHAVIOR; CARBONYL; FILM AB Development of crystallinity in NEW-TPI semicrystalline polyimide has been studied using differential scanning calorimetry (DSC), wide (WAXS), and small angle X-ray scattering (SAXS). Crystallinity of the fully imidized powder, pellet. or film processed NEW-TPI can occur from the melt, and depends upon the holding temperature of the melt. Repetitive exposure to elevated temperatures supresses the development of crystallinity from the melt state. In amorphous pellets and film, crystallinity can also develop by cold crystallization from the rubbery amorphous state. SAXS results show that during cold crystallization, NEW-TPI develops a periodic structure consistent with formation of alternating crystal-amorphous stacks, but with crystals only a few molecular repeat units thick. Kinetics of nonisothermal crystallization were studied as a function of heating rate and could be described using the Ozawa analysis. Non-isothermal crystallization proceeds at a slower rate in NEW-TPI than in other high temperature thermoplastics such as PEEK, and with a much narrower processing window. The maximum degree of crystallinity that could develop during heating was 0.34, which occurred at a rate of 5-degrees-C/min. Similar degrees of crystallinity could be introduced by heating amorphous NEW-TPI film in N-methylpyrrolidone. C1 BROOKHAVEN NATL SYNCHROTRON LIGHT SOURCE,BROOKHAVEN,NY. RP FRILER, JB (reprint author), MIT,DEPT MAT SCI & ENGN,CAMBRIDGE,MA 02139, USA. NR 51 TC 39 Z9 39 U1 3 U2 11 PU SOC PLASTICS ENG INC PI BROOKFIELD CENTER PA 14 FAIRFIELD DR, BROOKFIELD CENTER, CT 06804-0403 SN 0032-3888 J9 POLYM ENG SCI JI Polym. Eng. Sci. PD MAY PY 1993 VL 33 IS 10 BP 587 EP 597 DI 10.1002/pen.760331003 PG 11 WC Engineering, Chemical; Polymer Science SC Engineering; Polymer Science GA LE117 UT WOS:A1993LE11700002 ER PT J AU SODEN, JM ANDERSON, RE AF SODEN, JM ANDERSON, RE TI IC FAILURE ANALYSIS - TECHNIQUES AND TOOLS FOR QUALITY AND RELIABILITY IMPROVEMENT SO PROCEEDINGS OF THE IEEE LA English DT Article ID MAGNETIC FORCE MICROSCOPY; INTEGRATED-CIRCUITS; RESOLUTION; POTENTIOMETRY AB Integrated circuit failure analysis is an important manufacturing function. It provides information necessary for technology advancement and for corrective action to improve quality and reliability. In this paper, the role of failure analysis is discussed, common and new techniques and tools are reviewed, and opportunities for the future are considered C1 SANDIA NATL LABS,CTR ELECTR QUAL & RELIABIL,ALBUQUERQUE,NM 87185. NR 81 TC 31 Z9 32 U1 0 U2 5 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9219 J9 P IEEE JI Proc. IEEE PD MAY PY 1993 VL 81 IS 5 BP 703 EP 715 DI 10.1109/5.220902 PG 13 WC Engineering, Electrical & Electronic SC Engineering GA LK866 UT WOS:A1993LK86600005 ER PT J AU MURRAY, MN HANSMA, HG BEZANILLA, M SANO, T OGLETREE, DF KOLBE, W SMITH, CL CANTOR, CR SPENGLER, S HANSMA, PK SALMERON, M AF MURRAY, MN HANSMA, HG BEZANILLA, M SANO, T OGLETREE, DF KOLBE, W SMITH, CL CANTOR, CR SPENGLER, S HANSMA, PK SALMERON, M TI ATOMIC FORCE MICROSCOPY OF BIOCHEMICALLY TAGGED DNA SO PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA LA English DT Article AB Small fragments of DNA of known length were made with the polymerase chain reaction. These fragments had biotin molecules covalently attached at their ends. They were subsequently labeled with a chimeric protein fusion between streptavidin and two immunoglobulin G-binding domains of staphyloccocal protein A. This tetrameric species was expected to bind up to four DNA molecules via their attached biotin moieties. The DNA-protein complex was deposited on mica and imaged with an atomic force microscope. The images revealed the protein chimera at the expected location at the ends of the strands of DNA as well as the expected dimers, trimers, and tetramers of DNA bound to a single protein. C1 LAWRENCE BERKELEY LAB,DIV MAT SCI,BERKELEY,CA 94720. UNIV CALIF SANTA BARBARA,DEPT PHYS,SANTA BARBARA,CA 93106. BOSTON UNIV,CTR ADV BIOTECHNOL,BOSTON,MA 02215. RP MURRAY, MN (reprint author), LAWRENCE BERKELEY LAB,CTR HUMAN GENOME,BERKELEY,CA 94720, USA. RI Ogletree, D Frank/D-9833-2016; OI Ogletree, D Frank/0000-0002-8159-0182; Smith, Cassandra/0000-0002-0346-8907 NR 25 TC 54 Z9 54 U1 1 U2 10 PU NATL ACAD SCIENCES PI WASHINGTON PA 2101 CONSTITUTION AVE NW, WASHINGTON, DC 20418 SN 0027-8424 J9 P NATL ACAD SCI USA JI Proc. Natl. Acad. Sci. U. S. A. PD MAY 1 PY 1993 VL 90 IS 9 BP 3811 EP 3814 DI 10.1073/pnas.90.9.3811 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA LA430 UT WOS:A1993LA43000009 PM 8483898 ER PT J AU KAMMORGAN, LNW SMITHGILL, SJ TAYLOR, MG ZHANG, L WILSON, AC KIRSCH, JF AF KAMMORGAN, LNW SMITHGILL, SJ TAYLOR, MG ZHANG, L WILSON, AC KIRSCH, JF TI HIGH-RESOLUTION MAPPING OF THE HYHEL-10 EPITOPE OF CHICKEN LYSOZYME BY SITE-DIRECTED MUTAGENESIS SO PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA LA English DT Article DE EPITOPE MAPPING; PROTEIN PROTEIN INTERACTION ID ANTIBODY-ANTIGEN COMPLEX; AMINO-ACID SEQUENCE; EGG-WHITE LYSOZYME; STAPHYLOCOCCAL NUCLEASE; 3-DIMENSIONAL STRUCTURE; BINDING; PROTEINS; SURFACE; ENZYME AB The complex formed between hen egg white lysozyme (HEL) and the monoclonal antibody HyHEL-10 Fab fragment has an interface composed of van der Waals interactions, hydrogen bonds, and a single ion pair. The antibody overlaps part of the active site cleft. Putative critical residues within the epitope region of HEL, identified from the x-ray crystallographic structure of the complex, were replaced by site-directed mutagenesis to probe their relative importance in determining affinity of the antibody for HEL. Twenty single mutations of HEL at three contact residues (Arg-21HEL, Asp-101HEL, and Gly-102HEL) and at a partially buried residue (Asn-19HEL) in the epitope were made, and the effects on the free energies of dissociation were measured. A correlation between increased amino acid side-chain volume and reduced affinity for HELs with mutations at position 101 was observed. The D101G(HEL) mutant is bound to HyHEL-10 as tightly as wild-type enzyme, but the DELTADELTAG(dissoc) is increased by about 2.2 kcal (9.2 kJ)/mol for the larger residues in this position. HEL variants with lysine or histidine replacements for arginine at position 21 are bound 1.4-2.7 times more tightly than those with neutral or negatively charged amino acids in this position. These exhibit 1/40 the affinity for HyHEL-10 Fab compared with wild type. There is no side-chain volume correlation with DELTADELTAG(dissoc) at position 21. Although Gly-102HEL and Asn-19HEL are in the epitope, replacements at these positions have no effect on the affinity of HEL for the antibody. C1 LAWRENCE BERKELEY LAB,CTR ADV MAT,BERKELEY,CA 94720. NCI,GENET LAB,BETHESDA,MD 20892. RP KAMMORGAN, LNW (reprint author), UNIV CALIF BERKELEY,DEPT MOLEC & CELL BIOL,DIV BIOCHEM & MOLEC BIOL,BERKELEY,CA 94720, USA. FU NIAID NIH HHS [AI07989]; NIGMS NIH HHS [GM14514-01] NR 34 TC 59 Z9 59 U1 1 U2 2 PU NATL ACAD SCIENCES PI WASHINGTON PA 2101 CONSTITUTION AVE NW, WASHINGTON, DC 20418 SN 0027-8424 J9 P NATL ACAD SCI USA JI Proc. Natl. Acad. Sci. U. S. A. PD MAY 1 PY 1993 VL 90 IS 9 BP 3958 EP 3962 DI 10.1073/pnas.90.9.3958 PG 5 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA LA430 UT WOS:A1993LA43000039 PM 7683415 ER PT J AU BRAIG, K SIMON, M FURUYA, F HAINFELD, JF HORWICH, AL AF BRAIG, K SIMON, M FURUYA, F HAINFELD, JF HORWICH, AL TI A POLYPEPTIDE BOUND BY THE CHAPERONIN GROEL IS LOCALIZED WITHIN A CENTRAL CAVITY SO PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA LA English DT Article DE PROTEIN FOLDING ID RIBULOSE BISPHOSPHATE CARBOXYLASE; ESCHERICHIA-COLI; MOLECULAR CHAPERONE; PROTEIN; MITOCHONDRIA; BINDING; HSP60; RECONSTITUTION; PURIFICATION; AGGREGATION AB Chaperonins are oligomeric protein complexes that play an essential role in the cell, mediating ATP-dependent polypeptide chain folding in a variety of cellular compartments. They appear to bind early folding intermediates, preventing their aggregation; in the presence of MgATP and a cochaperonin, bound polypeptides are released in a stepwise manner, associated with folding to the native state. Chaperonin complexes appear in the electron microscope as cylindrical structures, usually composed of two stacked rings, each containing, by negative staining, an electron dense central ''hole'' almost-equal-to 6.0 nm in diameter. We sought to identify the site on the Escherichia coli chaperonin groEL, where the ''molten globule''-like intermediate of dihydrofolate reductase (DHFR) becomes bound, by examining in the scanning transmission electron microscope complexes formed between groEL and DHFR molecules bearing covalently crosslinked 1.4-nm gold clusters. In top views of the groEL complexes, gold densities were observed in the central region; in side views, the densities were seen at the end portions of the cylinders, corresponding to positions within the individual rings. In some cases, two gold densities were observed in the same groEL complex. We conclude that folding intermediates are bound inside central cavities within individual chaperonin rings. In this potentially sequestered location, folding intermediates with a compact conformation can be bound at multiple sites by surrounding monomeric members of the ring; localization of folding within the cavity could also facilitate rebinding of structures that initially fail to incorporate properly into the folding protein. C1 YALE UNIV,SCH MED,DEPT GENET,NEW HAVEN,CT 06510. BROOKHAVEN NATL LAB,DEPT BIOL,UPTON,NY 11973. RP BRAIG, K (reprint author), YALE UNIV,SCH MED,HOWARD HUGHES MED INST,333 CEDAR ST,NEW HAVEN,CT 06510, USA. NR 41 TC 170 Z9 171 U1 0 U2 3 PU NATL ACAD SCIENCES PI WASHINGTON PA 2101 CONSTITUTION AVE NW, WASHINGTON, DC 20418 SN 0027-8424 J9 P NATL ACAD SCI USA JI Proc. Natl. Acad. Sci. U. S. A. PD MAY 1 PY 1993 VL 90 IS 9 BP 3978 EP 3982 DI 10.1073/pnas.90.9.3978 PG 5 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA LA430 UT WOS:A1993LA43000043 PM 8097882 ER PT J AU DOSANJH, MK LOECHLER, EL SINGER, B AF DOSANJH, MK LOECHLER, EL SINGER, B TI EVIDENCE FROM INVITRO REPLICATION THAT O6-METHYLGUANINE CAN ADOPT MULTIPLE CONFORMATIONS SO PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA LA English DT Article ID DNA-REPAIR METHYLTRANSFERASE; HAMSTER OVARY CELLS; ESCHERICHIA-COLI; MUTAGENESIS; DUPLEX; O-6-METHYLGUANINE; KINETICS; O4-METHYLTHYMINE; OLIGONUCLEOTIDE; MECHANISM AB The effect of O6-methylguanine (m6G) on replication, in a partially double-stranded defined 25-base oligonucleotide, has been studied under nonlimiting conditions of unmodified dNTPs and over an extended time period, using the Klenow fragment of Escherichia coli DNA polymerase I. The sequence surrounding m6G has flanking cytosines (C-m6G-C), and the initial steady-state kinetics have been reported. When the primer was annealed so that the first base to be replicated was m6G, replication was virtually complete in almost-equal-to 5 min, although the reaction appears biphasic. When annealed with a primer where thymine or cytosine is paired opposite template m6G, about half the molecules were replicated in the first 15 sec, and no significant further replication was seen over a 1-hr period. When m6G was dealkylated by DNA-O6-methylguanine-methyltransferase, replication was rapid with no blockage. These data suggest that there can be two (or more) conformations of m6G. In these studies the term syn refers to conformers interfering with base-pairing, whereas anti refers to those allowing such base-pairing. Previous physical studies by others indicate that syn- and anti-conformers of the methyl group relative to the N1 of guanine are possible. Here molecular modeling/computational studies are described, suggesting that syn- and anti-m6G can be of similar energy in DNA, and, therefore, these two conformers may explain the two types of species observed during in vitro replication. An alternative explanation could be the possibility that the different species may manifest differential interactions of m6G with Klenow fragment. These results may provide a rationale for why m6G lesions in vivo have been reported to be lethal as well as mutagenic. C1 BOSTON UNIV,DEPT BIOL,BOSTON,MA 02215. RP DOSANJH, MK (reprint author), LAWRENCE BERKELEY LAB,DIV LIFE SCI,DONNER LAB,BERKELEY,CA 94720, USA. FU NCI NIH HHS [CA42736, CA50432] NR 31 TC 23 Z9 23 U1 0 U2 0 PU NATL ACAD SCIENCES PI WASHINGTON PA 2101 CONSTITUTION AVE NW, WASHINGTON, DC 20418 SN 0027-8424 J9 P NATL ACAD SCI USA JI Proc. Natl. Acad. Sci. U. S. A. PD MAY 1 PY 1993 VL 90 IS 9 BP 3983 EP 3987 DI 10.1073/pnas.90.9.3983 PG 5 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA LA430 UT WOS:A1993LA43000044 PM 8483914 ER PT J AU DOBSON, JE AF DOBSON, JE TI A RATIONALE FOR THE NATIONAL CENTER FOR GEOGRAPHIC INFORMATION AND ANALYSIS SO PROFESSIONAL GEOGRAPHER LA English DT Editorial Material ID AUTOMATED GEOGRAPHY RP DOBSON, JE (reprint author), MARTIN MARIETTA ENERGY SYST INC,OAK RIDGE NATL LAB,OAK RIDGE,TN 37831, USA. NR 48 TC 5 Z9 5 U1 0 U2 1 PU BLACKWELL PUBLISHERS PI CAMBRIDGE PA 350 MAIN STREET, STE 6, CAMBRIDGE, MA 02148-5023 SN 0033-0124 J9 PROF GEOGR JI Prof. Geogr. PD MAY PY 1993 VL 45 IS 2 BP 207 EP 215 DI 10.1111/j.0033-0124.1993.00207.x PG 9 WC Geography SC Geography GA LD329 UT WOS:A1993LD32900008 ER PT J AU DUBCHAK, I HOLBROOK, SR KIM, SH AF DUBCHAK, I HOLBROOK, SR KIM, SH TI PREDICTION OF PROTEIN FOLDING CLASS FROM AMINO-ACID-COMPOSITION SO PROTEINS-STRUCTURE FUNCTION AND GENETICS LA English DT Article DE PROTEIN STRUCTURE PREDICTION; NEURAL NETWORKS; AMINO ACID COMPOSITION; PROTEIN FOLDING CLASSES; 4-ALPHA-HELICAL BUNDLES; PARALLEL (ALPHA/BETA)8 BARRELS; NUCLEOTIDE BINDING FOLD; IMMUNOGLOBULIN FOLD ID SECONDARY STRUCTURE PREDICTION; 3-DIMENSIONAL STRUCTURE; NEURAL NETWORK; BINDING DOMAIN; DATA-BANK; SEQUENCE; CHARACTERS; RECEPTOR; CLASSIFICATION; CONFORMATION AB An empirical relation between the amino acid composition and three-dimensional folding pattern of several classes of proteins has been determined. Computer simulated neural networks have been used to assign proteins to one of the following classes based on their amino acid composition and size: (1) 4alpha-helical bundles, (2) parallel (alpha/beta)8 barrels, (3) nucleotide binding fold, (4) immunoglobulin fold, or (5) none of these. Networks trained on the known crystal structures as well as sequences of closely related proteins are shown to correctly predict folding classes of proteins not represented in the training set with an average accuracy of 87%. Other folding motifs can easily be added to the prediction scheme once larger databases become available. Analysis of the neural network weights reveals that amino acids favoring prediction of a folding class are usually over represented in that class and amino acids with unfavorable weights are underrepresented in composition. The neural networks utilize combinations of these multiple small variations in amino acid composition in order to make a prediction. The favorably weighted amino acids in a given class also form the most intramolecular interactions with other residues in proteins of that class. A detailed examination of the contacts of these amino acids reveals some general patterns that may help stabilize each folding class. C1 LAWRENCE BERKELEY LAB,DEPT CHEM,BERKELEY,CA 94720. LAWRENCE BERKELEY LAB,DIV STRUCT BIOL,BERKELEY,CA 94720. NR 39 TC 66 Z9 66 U1 0 U2 1 PU WILEY-LISS PI NEW YORK PA DIV JOHN WILEY & SONS INC 605 THIRD AVE, NEW YORK, NY 10158-0012 SN 0887-3585 J9 PROTEINS JI Proteins PD MAY PY 1993 VL 16 IS 1 BP 79 EP 91 DI 10.1002/prot.340160109 PG 13 WC Biochemistry & Molecular Biology; Biophysics SC Biochemistry & Molecular Biology; Biophysics GA KZ795 UT WOS:A1993KZ79500008 PM 8497486 ER PT J AU SMITH, DH LIM, KH AF SMITH, DH LIM, KH TI PHASE AND EMULSION MORPHOLOGY DIAGRAMS OF NONIONIC AMPHIPHILE OIL-WATER SYSTEMS AND THEIR INTERRELATIONSHIPS SO PURE AND APPLIED CHEMISTRY LA English DT Article; Proceedings Paper CT 12TH CONF ON CHEMICAL THERMODYNAMICS / 47TH CALORIMETRY CONF CY AUG 16-21, 1992 CL SNOWBIRD, UT SP INT UNION PURE & APPL CHEM, PHYS CHEM DIV, COMMISS THERMODYNAM, BRIGHAM YOUNG UNIV, ELECT POWER RES INST, PARR INSTRUMENT, US DOE, CALORIMETRY CONF, MONSANTO, TRONAC, US NATL SCI FDN ID INVERSION; CATASTROPHE AB For two-phase, non-multiple emulsions. the emulsion morphology diagram shows, as a function of temperature and phase or component concentration, which phase is dispersed and which is the continuous one, as well as the temperatures and compositions at which inversions occur. The emulsion morphology diagram plays for emulsions a role that is similar to the role played by phase diagrams for phases. C1 UNIV OKLAHOMA,SCH CHEM ENGN & MAT SCI,NORMAN,OK 73019. UNIV OKLAHOMA,INST APPL SURFACTANT RES,NORMAN,OK 73019. W VIRGINIA UNIV,DEPT CHEM ENGN,MORGANTOWN,WV 26506. RP SMITH, DH (reprint author), MORGANTOWN ENERGY TECHNOL CTR,MORGANTOWN,WV 26507, USA. NR 21 TC 5 Z9 5 U1 0 U2 0 PU BLACKWELL SCIENCE LTD PI OXFORD PA OSNEY MEAD, OXFORD, OXON, ENGLAND OX2 0EL SN 0033-4545 J9 PURE APPL CHEM JI Pure Appl. Chem. PD MAY PY 1993 VL 65 IS 5 BP 977 EP 982 DI 10.1351/pac199365050977 PG 6 WC Chemistry, Multidisciplinary SC Chemistry GA KZ975 UT WOS:A1993KZ97500018 ER PT J AU HOPPER, RW AF HOPPER, RW TI CAPILLARITY-DRIVEN PLANE STOKES-FLOW EXTERIOR TO A PARABOLA SO QUARTERLY JOURNAL OF MECHANICS AND APPLIED MATHEMATICS LA English DT Article ID FREE-SURFACE AB The free creeping viscous incompressible plane flow of the infinite region exterior to a parabola, driven solely by surface tension, is analysed. The rigid-body motion is arbitrary, so the velocity at the apex set to zero. With no further conditions, the flow is incompletely determined. There is a basic field that gives a surface velocity tangent to the surface of the parabola and directed towards its apex. This would leave the boundary unchanging and stationary. Superimposed is a flow involving an arbitrary constant. When this is real, the shape evolves through a continuous sequence of parabolas of changing apex curvature, changing at a rate determined by supplemental boundary conditions. These must be consistent with the specified conditions on the parabola. It appears difficult to devise a realistic far field that would 'select' a particular parabola. RP HOPPER, RW (reprint author), LAWRENCE LIVERMORE NATL LAB,DEPT CHEM & MAT SCI,LIVERMORE,CA 94550, USA. NR 20 TC 7 Z9 7 U1 0 U2 3 PU OXFORD UNIV PRESS UNITED KINGDOM PI OXFORD PA WALTON ST JOURNALS DEPT, OXFORD, ENGLAND OX2 6DP SN 0033-5614 J9 Q J MECH APPL MATH JI Q. J. Mech. Appl. Math. PD MAY PY 1993 VL 46 BP 193 EP 210 DI 10.1093/qjmam/46.2.193 PN 2 PG 18 WC Mathematics, Applied; Mechanics SC Mathematics; Mechanics GA LR858 UT WOS:A1993LR85800002 ER PT J AU GURLEY, LR LONDON, JE TIETJEN, GL VANDERKOGEL, AJ DETHLOFF, LA LEHNERT, BE AF GURLEY, LR LONDON, JE TIETJEN, GL VANDERKOGEL, AJ DETHLOFF, LA LEHNERT, BE TI LUNG HYPERPERMEABILITY AND CHANGES IN BIOCHEMICAL-CONSTITUENTS IN BRONCHOALVEOLAR LAVAGE FLUIDS FOLLOWING X-IRRADIATION OF THE THORAX SO RADIATION RESEARCH LA English DT Article ID PULMONARY SURFACTANT SYSTEM; RAT LUNG; RADIATION PNEUMONITIS; VASCULAR-PERMEABILITY; MOUSE LUNG; INJURY; CAPILLARY; FIBROSIS; PROTEINS; SINGLE C1 LOS ALAMOS NATL LAB, DIV LIFE SCI, LOS ALAMOS, NM 87545 USA. WARNER LAMBERT PARKE DAVIS, PARKE DAVIS PHARMACEUT RES, DEPT PATHOL & EXPTL TOXICOL, ANN ARBOR, MI USA. CATHOLIC UNIV NIJMEGEN, INST RADIOTHERAPY, NIJMEGEN, NETHERLANDS. NR 52 TC 9 Z9 10 U1 0 U2 0 PU RADIATION RESEARCH SOC PI LAWRENCE PA 810 E TENTH STREET, LAWRENCE, KS 66044 USA SN 0033-7587 EI 1938-5404 J9 RADIAT RES JI Radiat. Res. PD MAY PY 1993 VL 134 IS 2 BP 151 EP 159 DI 10.2307/3578454 PG 9 WC Biology; Biophysics; Radiology, Nuclear Medicine & Medical Imaging SC Life Sciences & Biomedicine - Other Topics; Biophysics; Radiology, Nuclear Medicine & Medical Imaging GA LB850 UT WOS:A1993LB85000004 PM 8488250 ER PT J AU LUFT, BJ DUNN, JJ DATTWYLER, RJ GORGONE, G GOREVIC, PD SCHUBACH, WH AF LUFT, BJ DUNN, JJ DATTWYLER, RJ GORGONE, G GOREVIC, PD SCHUBACH, WH TI CROSS-REACTIVE ANTIGENIC DOMAINS OF THE FLAGELLIN PROTEIN OF BORRELIA-BURGDORFERI SO RESEARCH IN MICROBIOLOGY LA English DT Article DE LYME BORRELIOSIS; SYPHILIS; FLAGELLIN; BORRELIA-BURGDORFERI; TREPONEMA-PALLIDUM; ANTIGENICITY; CROSS-REACTIVITY; DELETION CONSTRUCT ID LYME-DISEASE; GENE; RESPONSES AB The p41 flagellin of Borrelia burgdorferi is the most common antigen recognized by serum of patients with Lyme borreliosis. This antigen shares amino acid homology, particularly in the amino and carboxy termini, with periflagellar antigens found in other microorganisms including Treponema pallidum. We cloned and expressed the p41 open reading frame in Escherichia coli and expressed it both as TrpE fusion and full-length unfused proteins. Also, we generated deletion constructs of various portions of the gene. Sera from patients with late Lyme borreliosis and secondary syphilis were used to identify the recombinant proteins by immunoblot analysis. Sera from 26 patients with Lyme borreliosis, 20 with secondary syphilis and 10 controls were used to identify cross-reactive domains of the B. burgdorferi flagellin. The variable region (amino acids 131-234) of the protein was recognized by 59% (15/26) of patients with late Lyme borreliosis compared to 30% (6/20) of patients with secondary syphilis and no (0/10) control patients. It appears that cross-reactive epitopes between B. burgdorferi and T. pallidum extend to the variable region of the flagellin. C1 BROOKHAVEN NATL LAB, DEPT BIOL, UPTON, NY 11973 USA. RP SUNY, DEPT MED, HSC 15T-080, STONY BROOK, NY 11794 USA. OI Dattwyler, Raymond/0000-0002-1983-1301; Luft, Benjamin/0000-0001-9008-7004 FU PHS HHS [R01 A132454] NR 24 TC 16 Z9 16 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0923-2508 EI 1769-7123 J9 RES MICROBIOL JI Res. Microbiol. PD MAY PY 1993 VL 144 IS 4 BP 251 EP 257 DI 10.1016/0923-2508(93)90009-Q PG 7 WC Microbiology SC Microbiology GA LL322 UT WOS:A1993LL32200001 PM 7504314 ER PT J AU KIM, CY KING, PL PIANETTA, P KELLY, MA BRYSON, CA AF KIM, CY KING, PL PIANETTA, P KELLY, MA BRYSON, CA TI IMAGING BAND-PASS ANALYZER USING DOUBLE 90-DEGREES SPHERICAL ANALYZERS SO REVIEW OF SCIENTIFIC INSTRUMENTS LA English DT Article ID PHOTOELECTRON SPECTROMETER; RESOLUTION; MICROSCOPY AB The design and testing of an imaging band-pass analyzer (BPA) consisting of two 90-degrees spherical sectors operating in a magnetic-field-free region is described. Image electrons injected nearly parallel to one another and perpendicular to the first 90-degrees sector are focused into an energy plane where electrons of desired energy are band-pass filtered. A second 90-degrees sector is used to recover the energy-filtered image. With a 1-mm aperture, energy resolution of 1% and spatial resolution of 0.01% of the main path radius are calculated and agree well with the test results over an image size of 12 X 12 mm2. The addition of this analyzer to our magnetic projection photoelectron microscope poses an additional technological problem in that the electrons are required to pass from a relatively high-field area to a field-free region without disruption of the image. Design considerations for a structure that abruptly terminates a magnetic field yet is transparent to image electrons are described. C1 STANFORD UNIV,STANFORD,CA 94305. SURFACE INTERFACE,MT VIEW,CA 94041. RP KIM, CY (reprint author), SSRL,STANFORD,CA 94309, USA. NR 15 TC 4 Z9 4 U1 2 U2 2 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0034-6748 J9 REV SCI INSTRUM JI Rev. Sci. Instrum. PD MAY PY 1993 VL 64 IS 5 BP 1187 EP 1193 DI 10.1063/1.1144116 PG 7 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA LB849 UT WOS:A1993LB84900013 ER PT J AU SCHWARZ, RB RUBIN, JB AF SCHWARZ, RB RUBIN, JB TI HEATING STAGE FOR INSITU STUDIES OF THIN-FILM REACTIONS SO REVIEW OF SCIENTIFIC INSTRUMENTS LA English DT Article ID DIFFUSION; ZR AB We describe a method for measuring and controlling the temperature of thin ceramic plates which are used as substrates for the deposition of thin films in high vacuum. The ceramic plates have an embedded platinum resistor which acts as both heating element and thermometer. The temperature of the substrate is controlled by an electronic feedback circuit. This arrangement enables accurate measurements of the thin-film temperature. In addition, the system has a fast response time and excellent long-term temperature stability. We describe an application where the temperature control system is combined with ac resistance measurements to study the kinetics of a solid-state interdiffusion reaction in Ni-Zr multilayers. RP SCHWARZ, RB (reprint author), LOS ALAMOS NATL LAB,CTR MAT SCI,MS K765,LOS ALAMOS,NM 87545, USA. NR 8 TC 1 Z9 1 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0034-6748 J9 REV SCI INSTRUM JI Rev. Sci. Instrum. PD MAY PY 1993 VL 64 IS 5 BP 1292 EP 1295 DI 10.1063/1.1144082 PG 4 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA LB849 UT WOS:A1993LB84900033 ER PT J AU GARDIN, DE SOMORJAI, GA AF GARDIN, DE SOMORJAI, GA TI ULTRAHIGH-VACUUM CHAMBER EQUIPPED WITH A REACTION CELL FOR STUDYING LIQUID-PHASE CATALYTIC REACTIONS SO REVIEW OF SCIENTIFIC INSTRUMENTS LA English DT Article ID WELL-DEFINED SURFACES; SUPPORTED PLATINUM; CYCLOHEXENE; PRESSURE; HYDROGENATION AB We describe the construction and operation of a liquid-phase reaction cell designed in our laboratory that is attached to an ultrahigh-vacuum (UHV) chamber equipped with the traditional surface science techniques for structure and composition analysis. The sample surface can be prepared and characterized in the UHV chamber prior to transfer in the liquid-phase reaction cell. The transfer has been designed so that there is no loss of the UHV chamber vacuum integrity, as few parts as possible come into contact with the liquid, the surface stays clean during the transfer. The liquid-phase reaction cell itself is designed to study liquid-phase hydrogenation reactions at pressures up to 2 atm and temperatures up to 70-degrees-C. A 1-mm-diam liquid jet with a velocity up to 6 m/s is produced by a gear pump that is incident on the sample surface to allow good mass transfer at the liquid-solid interface. The progress of the reaction is followed by gas chromatography. We report the reaction rate data for the hydrogenation of cyclohexene on a platinum foil. C1 UNIV CALIF BERKELEY, DEPT CHEM, BERKELEY, CA 94720 USA. RP LAWRENCE BERKELEY LAB, DIV MAT SCI, BERKELEY, CA 94720 USA. NR 14 TC 5 Z9 5 U1 0 U2 4 PU AMER INST PHYSICS PI MELVILLE PA 1305 WALT WHITMAN RD, STE 300, MELVILLE, NY 11747-4501 USA SN 0034-6748 EI 1089-7623 J9 REV SCI INSTRUM JI Rev. Sci. Instrum. PD MAY PY 1993 VL 64 IS 5 BP 1305 EP 1308 PG 4 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA LB849 UT WOS:A1993LB84900035 ER PT J AU SELLERS, CH LEE, JE HYDE, TA AF SELLERS, CH LEE, JE HYDE, TA TI IMPROVED FURNACE TEMPERATURE CONTROL FOR THE PARC VIBRATING SAMPLE MAGNETOMETER SO REVIEW OF SCIENTIFIC INSTRUMENTS LA English DT Note AB Temperature control of furnaces to be used with the PARC vibrating sample magnetometer can be greatly improved if a separate temperature controller is utilized. A control circuit that allows easy temperature programming and ramping is described, as well as sample holder modifications which permit accurate measurement of the sample temperature. RP SELLERS, CH (reprint author), EG&G IDAHO INC,IDAHO NATL ENGN LAB,IDAHO FALLS,ID 83415, USA. NR 4 TC 0 Z9 0 U1 0 U2 1 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0034-6748 J9 REV SCI INSTRUM JI Rev. Sci. Instrum. PD MAY PY 1993 VL 64 IS 5 BP 1365 EP 1366 DI 10.1063/1.1144097 PG 2 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA LB849 UT WOS:A1993LB84900049 ER PT J AU NIEH, TG WADSWORTH, J AF NIEH, TG WADSWORTH, J TI EFFECTS OF ZR ON THE HIGH-STRAIN RATE SUPERPLASTICITY OF 2124 AL SO SCRIPTA METALLURGICA ET MATERIALIA LA English DT Article ID MECHANICALLY ALLOYED ALUMINUM; BEHAVIOR; COMPOSITE RP NIEH, TG (reprint author), LAWRENCE LIVERMORE NATL LAB,POB 808,L350,LIVERMORE,CA 94550, USA. RI Nieh, Tai-Gang/G-5912-2011 OI Nieh, Tai-Gang/0000-0002-2814-3746 NR 17 TC 37 Z9 37 U1 0 U2 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0956-716X J9 SCRIPTA METALL MATER JI Scr. Metall. Materialia PD MAY 1 PY 1993 VL 28 IS 9 BP 1119 EP 1124 DI 10.1016/0956-716X(93)90020-S PG 6 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA KV019 UT WOS:A1993KV01900020 ER PT J AU DONGARRA, JJ SIDANI, M AF DONGARRA, JJ SIDANI, M TI A PARALLEL ALGORITHM FOR THE NONSYMMETRIC EIGENVALUE PROBLEM SO SIAM JOURNAL ON SCIENTIFIC COMPUTING LA English DT Article DE EIGENVALUE PROBLEM; DIVIDE AND CONQUER; PARALLEL COMPUTING ID EIGENPROBLEM AB This paper describes a parallel algorithm for computing the eigenvalues and eigenvectors of a nonsymmetric matrix. The algorithm is based on a divide-and-conquer procedure and uses an iterative refinement technique. C1 OAK RIDGE NATL LAB,MATH SCI SECT,OAK RIDGE,TN 37831. RP DONGARRA, JJ (reprint author), UNIV TENNESSEE,DEPT COMP SCI,KNOXVILLE,TN 37996, USA. RI Dongarra, Jack/E-3987-2014 NR 19 TC 16 Z9 16 U1 0 U2 0 PU SIAM PUBLICATIONS PI PHILADELPHIA PA 3600 UNIV CITY SCIENCE CENTER, PHILADELPHIA, PA 19104-2688 SN 1064-8275 J9 SIAM J SCI COMPUT JI SIAM J. Sci. Comput. PD MAY PY 1993 VL 14 IS 3 BP 542 EP 569 DI 10.1137/0914035 PG 28 WC Mathematics, Applied SC Mathematics GA KZ298 UT WOS:A1993KZ29800004 ER PT J AU JONES, MT PLASSMANN, PE AF JONES, MT PLASSMANN, PE TI A PARALLEL GRAPH-COLORING HEURISTIC SO SIAM JOURNAL ON SCIENTIFIC COMPUTING LA English DT Article DE DISTRIBUTED MEMORY COMPUTERS; GRAPH COLORING HEURISTICS; PARALLEL ALGORITHMS; RANDOM ALGORITHMS; SPARSE MATRICES ID MATRICES AB The problem of computing good graph colorings arises in many diverse applications, such as in the estimation of sparse Jacobians and in the development of efficient, parallel iterative methods for solving sparse linear systems. This paper presents an asynchronous graph coloring heuristic well suited to distributed memory parallel computers. Experimental results obtained on an Intel iPSC/860 are presented, which demonstrate that, for graphs arising from finite element applications, the heuristic exhibits scalable performance and generates colorings usually within three or four colors of the best-known linear time sequential heuristics. For bounded degree graphs, it is shown that the expected running time of the heuristic under the P-RAM computation model is bounded by EO(log(n)/log log(n)). This bound is an improvement over the previously known best upper bound for the expected running time of a random heuristic for the graph coloring problem. RP JONES, MT (reprint author), ARGONNE NATL LAB,DIV MATH & COMP SCI,9700 S CASS AVE,ARGONNE,IL 60439, USA. NR 11 TC 68 Z9 70 U1 0 U2 0 PU SIAM PUBLICATIONS PI PHILADELPHIA PA 3600 UNIV CITY SCIENCE CENTER, PHILADELPHIA, PA 19104-2688 SN 1064-8275 J9 SIAM J SCI COMPUT JI SIAM J. Sci. Comput. PD MAY PY 1993 VL 14 IS 3 BP 654 EP 669 DI 10.1137/0914041 PG 16 WC Mathematics, Applied SC Mathematics GA KZ298 UT WOS:A1993KZ29800010 ER PT J AU BISCHOF, CH PAN, CT TANG, PTP AF BISCHOF, CH PAN, CT TANG, PTP TI A CHOLESKY UPDATING AND DOWNDATING ALGORITHM FOR SYSTOLIC AND SIMD ARCHITECTURES SO SIAM JOURNAL ON SCIENTIFIC COMPUTING LA English DT Article DE CHOLESKY FACTORIZATION; UPDATING; DOWNDATING; SYSTOLIC ALGORITHM; SIMD ALGORITHM ID FACTORIZATIONS AB This paper presents an algorithm for maintaining Cholesky factors of symmetric positive definite matrices under arbitrary rank-one changes. The algorithm synthesizes Carlson's updating algorithm, and the downdating algorithm recently suggested by Pan to arrive at an algorithm which is both simple and allows for the pipelining of up- and downdates (in any order). On an array of O(n2) processors, the algorithm allows an n x n matrix to be updated at a cost per update that is independent of n. Implementation results on the 1024-processor AMT DAP-510 emphasize the simplicity and practicality of the proposed scheme. C1 NO ILLINOIS UNIV,DEPT MATH SCI,DE KALB,IL 60115. RP BISCHOF, CH (reprint author), ARGONNE NATL LAB,DIV MATH & COMP SCI,9700 S CASS AVE,ARGONNE,IL 60439, USA. RI Bischof, Christian/D-2897-2009 NR 12 TC 7 Z9 7 U1 1 U2 1 PU SIAM PUBLICATIONS PI PHILADELPHIA PA 3600 UNIV CITY SCIENCE CENTER, PHILADELPHIA, PA 19104-2688 SN 1064-8275 J9 SIAM J SCI COMPUT JI SIAM J. Sci. Comput. PD MAY PY 1993 VL 14 IS 3 BP 670 EP 676 DI 10.1137/0914042 PG 7 WC Mathematics, Applied SC Mathematics GA KZ298 UT WOS:A1993KZ29800011 ER PT J AU BOLTON, H SMITH, JL LINK, SO AF BOLTON, H SMITH, JL LINK, SO TI SOIL MICROBIAL BIOMASS AND ACTIVITY OF A DISTURBED AND UNDISTURBED SHRUB-STEPPE ECOSYSTEM SO SOIL BIOLOGY & BIOCHEMISTRY LA English DT Article ID SEMI-DESERT ECOSYSTEMS; NITROGEN MINERALIZATION; ADENOSINE-TRIPHOSPHATE; CHEMICAL-PATTERNS; ATP; COMMUNITIES; SAGEBRUSH; BACTERIA; MOISTURE; MATTER AB Disturbance of shrub-steppe soils and alterations in plant cover may affect the distribution, size and activity of soil microorganisms and their ability to biogeochemically cycle essential nutrients. Therefore, the soil microbial biomass and activity and selected soil enzyme activities were determined for two arid ecosystems, an undisturbed perennial shrub-steppe and annual grassland, which was initially shrub-steppe and has been an annual grassland since the disturbance caused by farming ceased in the 1940s. Soils were sampled at 0-5 and 5-15 cm depths beneath sagebrush (Artemisia tridentata Nutt.), bluebunch wheatgrass [Elytrigia spicata (Pursh) D. R. Dewey] and cryptogamic soil lichen crust at the perennial site and beneath downy brome (Bromus tectorum L.) at the annual grassland site. Soils were analyzed for physical properties, inorganic N, microbial biomass C and N, respiration and several enzymes. The soil pH and bulk density usually increased, while inorganic N, total N and total C decreased as a function of soil depth. Soil microbial biomass C and N, soil respiration and soil dehydrogenase activity were 2-15 times higher in the top 5 cm of soil than at the 5-15 cm depth regardless of plant type. Loss of this surface soil would therefore be detrimental to microbially-mediated cycling of nutrients. Surface soil (0-5 cm depth) microbial biomass C and N and soil respiration, dehydrogenase and phosphatase activity were influenced by plant type and decreased in the order B. tectorum > A. tridentata = E. spicata > soil crust. Spatial distribution of plant species at the shrub-steppe site resulted in ''islands'' of enhanced microbial biomass and activity underneath the shrubs and grasses when compared to the interplant areas covered with soil crust. When plant cover was used to compute a landscape estimate of soil microbial biomass C and N for the perennial shrub-steppe and the annual grassland, similar values were obtained. This indicates that while the distribution of microorganisms may be more heterogeneous in the shrub-steppe, the average across the landscape is the same as the more homogeneous annual grassland. C1 WASHINGTON STATE UNIV, USDA ARS, PULLMAN, WA 99164 USA. RP BOLTON, H (reprint author), PACIFIC NW LAB, DEPT ENVIRONM SCI, MAILSTOP K4-06, 900 BATTELLE BLVD, RICHLAND, WA 99352 USA. RI Bolton, Harvey/E-5583-2011 NR 50 TC 116 Z9 120 U1 2 U2 37 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0038-0717 J9 SOIL BIOL BIOCHEM JI Soil Biol. Biochem. PD MAY PY 1993 VL 25 IS 5 BP 545 EP 552 DI 10.1016/0038-0717(93)90192-E PG 8 WC Soil Science SC Agriculture GA LB621 UT WOS:A1993LB62100004 ER PT J AU VERMEUL, VR ISTOK, JD FLINT, AL PIKUL, JL AF VERMEUL, VR ISTOK, JD FLINT, AL PIKUL, JL TI AN IMPROVED METHOD FOR QUANTIFYING SOIL MACROPOROSITY SO SOIL SCIENCE SOCIETY OF AMERICA JOURNAL LA English DT Article; Proceedings Paper CT 57TH ANNUAL MEETING OF THE SOIL SCIENCE SOC OF AMERICA CY NOV 07-12, 1993 CL CINCINNATI, OH SP SOIL SCI SOC AMER AB Quantitative information on macroporosity is needed to predict water flow and solute transport in field soils. A method was developed for determining the number, shape, and size distribution of soil macropores. Horizontal serial sections sawed from paraffin-impregnated soil cores were photographed under ultraviolet (UV) light. Anthracene, mixed with the paraffin, fluoresces a bright bluish white under UV light and provides a sharp contrast between the soil matrix and the paraffin-filled pore space. Section photographs were converted to 256 level, grey-scale digital images using a flat-bed scanner. Image processing was used to classify each pixel in a digital image as pore space or soil matrix, to group the pore space pixels into pores, and to measure the area and perimeter of each pore. The method was able to measure pores with an equivalent radius greater-than-or-equal-to 85 mum. Macroporosity in soil cores sampled form a tillage path and from an adjacent, undisturbed (no-till) region was quantified. Tillage sections contained, on the average, 9.4 macropores/cm2 with an equivalent macroporosity of 8%, while no-till sections contained 0.8 macropores/cm2 with an equivalent macroporosity of 0.3%. Computed intrinsic permeabilities for tillage sections that included macropore information were significantly larger than values computed using micropore information alone, suggesting that macropores must be included in permeability calculations when the number of macropores is large. The developed method should be useful for quantifying macroporosity in nonskeletal soils. C1 PACIFIC NW LAB, DEPT GEOSCI, RICHLAND, WA 99352 USA. US GEOL SCI, MERCURY, NV 89023 USA. USDA ARS, NO PLAINS SOIL & WATER RES CTR, SIDNEY, MT 59270 USA. RP ISTOK, JD (reprint author), OREGON STATE UNIV, DEPT CIVIL ENGN, CORVALLIS, OR 97331 USA. NR 12 TC 17 Z9 27 U1 0 U2 2 PU SOIL SCI SOC AMER PI MADISON PA 677 SOUTH SEGOE ROAD, MADISON, WI 53711 SN 0361-5995 J9 SOIL SCI SOC AM J JI Soil Sci. Soc. Am. J. PD MAY-JUN PY 1993 VL 57 IS 3 BP 809 EP 816 PG 8 WC Soil Science SC Agriculture GA LJ977 UT WOS:A1993LJ97700030 ER PT J AU ROUTBORT, JL MILLER, DJ ZAMIROWSKI, EJ GORETTA, KC AF ROUTBORT, JL MILLER, DJ ZAMIROWSKI, EJ GORETTA, KC TI PLASTICITY OF TLBA2CA2CU3OX SO SUPERCONDUCTOR SCIENCE & TECHNOLOGY LA English DT Article ID SUPERCONDUCTORS; DEFORMATION; CREEP AB Constant-strain-rate compression tests have been performed on polycrystalline TIBa2Ca2Cu3Ox superconductors (73-86% of theoretical density) for the first time. The tests were performed in air at temperatures of 750-850-degrees-C. Apparent steady-state stresses between 1 and 300 MPa were achieved for initial strain rates of 2 x 10(-6) to 4 x 10(-5) s-1. Deformation was probably controlled by viscous flow at the highest temperatures, but was dominated by dislocations at lower temperatures. C1 ARGONNE NATL LAB,DIV MAT & COMPONENTS TECHNOL,ARGONNE,IL 60439. RP ROUTBORT, JL (reprint author), ARGONNE NATL LAB,DIV MAT SCI,ARGONNE,IL 60439, USA. NR 16 TC 8 Z9 8 U1 0 U2 0 PU IOP PUBLISHING LTD PI BRISTOL PA TECHNO HOUSE, REDCLIFFE WAY, BRISTOL, ENGLAND BS1 6NX SN 0953-2048 J9 SUPERCOND SCI TECH JI Supercond. Sci. Technol. PD MAY PY 1993 VL 6 IS 5 BP 337 EP 342 DI 10.1088/0953-2048/6/5/005 PG 6 WC Physics, Applied; Physics, Condensed Matter SC Physics GA LE556 UT WOS:A1993LE55600005 ER PT J AU HALSTEAD, DM DEPRISTO, AE AF HALSTEAD, DM DEPRISTO, AE TI THIN-FILM GROWTH AND THE SCATTERING OF ATOMS FROM SURFACE ISLAND DEFECTS SO SURFACE SCIENCE LA English DT Article ID CORRECTED EFFECTIVE-MEDIUM; MOLECULAR-DYNAMICS SIMULATIONS; SELF-DIFFUSION; TRANSITION-METALS; IR ATOMS; TEMPERATURE; NUCLEATION; EPITAXY; CU; RH AB We investigate the potential energy surface and dynamics of atoms impinging upon pyramidal defects on fcc (100) and (111) surfaces. Illustrative molecular dynamics trajectory results are used to highlight the subtleties of the growth processes. Homoatomic systems of both Cu and Pd are considered in order to determine the influence of extreme differences in bonding coordination variation, i.e. the binding energy per atom decreases by a factor of 3.3 from Cu(bulk) to Cu2 but more dramatically by a factor of 7.5 for Pd(bulk) to Pd2. We find that stable adsorption sites on pyramidal facets only exist for three layer high (and higher) facets, but even these sites are not as energetically favorable as those at the pyramid's base. This single energetic effect can promote a Stranski-Krastanov type growth pattern, with a critical roughness of no less than three layers being required before a 3D growth mechanism can propagate in a surface temperature regime where post impact diffusion is small compared to the deposition rate. The transition to 3D growth at the minimum possible roughness would be found for Pd on the (100) face where sticking to the sides of even the three layer pyramid is a high probability event, at a low enough temperature to make post-impact diffusion negligible. However, for the Cu system, we find that the ''downward funneling'' mechanism smoothed the growth for the three layer pyramid and is still important for the five layer pyramid, indicating that Cu will exhibit layer-by-layer like growth even past three layers. A comparison of scattering simulations from defects show that the growth mode is diffusion limited on the fcc (100) crystal face, but becomes dominated by impact induced disruption of the original structure for a (111) surface. This implies that the (111) surface will grow more smoothly as a new atom displaces pre-adsorbed atoms more easily, an effect that is not included in the ''downward funneling'' model. The ratio of the diatomic molecule's binding energy to the bulk cohesive energy is shown to provide good insight into the preferred growth mechanism. As the ratio increases, at least in the range spanned by typical metals, the film grows more layer-by-layer like on the (100) surface and less layer-by-layer like on the (111) surface. On the (100) surface, stronger low coordination bonding makes the defect structures less able to adsorb the impacting atom on the sloped faces, increasing the effectiveness of ''downward funneling.'' On the (111) surface, stronger low coordination bonding inhibits impact disruption of the defects, decreasing this important smoothing mechanism. C1 IOWA STATE UNIV SCI & TECHNOL,DEPT CHEM,AMES,IA 50011. IOWA STATE UNIV SCI & TECHNOL,AMES LAB,AMES,IA 50011. NR 54 TC 26 Z9 26 U1 1 U2 4 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0039-6028 J9 SURF SCI JI Surf. Sci. PD MAY 1 PY 1993 VL 286 IS 3 BP 275 EP 289 DI 10.1016/0039-6028(93)90411-C PG 15 WC Chemistry, Physical; Physics, Condensed Matter SC Chemistry; Physics GA KZ163 UT WOS:A1993KZ16300007 ER PT J AU FRANK, IE FRIEDMAN, JH AF FRANK, IE FRIEDMAN, JH TI A STATISTICAL VIEW OF SOME CHEMOMETRICS REGRESSION TOOLS SO TECHNOMETRICS LA English DT Article DE MULTIPLE RESPONSE REGRESSION; PARTIAL LEAST SQUARES; PRINCIPAL COMPONENTS REGRESSION; RIDGE REGRESSION; VARIABLE SUBSET SELECTION ID PARTIAL LEAST-SQUARES; GENERALIZED INVERSES; LINEAR-REGRESSION; RIDGE-REGRESSION; MODEL AB Chemometrics is a field of chemistry that studies the application of statistical methods to chemical data analysis. In addition to borrowing many techniques from the statistics and engineering literatures, chemometrics itself has given rise to several new data-analytical methods. This article examines two methods commonly used in chemometrics for predictive modeling-partial least squares and principal components regression-from a statistical perspective. The goal is to try to understand their apparent successes and in what situations they can be expected to work well and to compare them with other statistical methods intended for those situations. These methods include ordinary least squares, variable subset selection, and ridge regression. C1 STANFORD UNIV,DEPT STAT,STANFORD,CA 94305. STANFORD UNIV,STANFORD LINEAR ACCELERATOR CTR,STANFORD,CA 94305. RP FRANK, IE (reprint author), JERLL INC,STANFORD,CA 94305, USA. NR 33 TC 928 Z9 954 U1 13 U2 97 PU AMER STATISTICAL ASSOC PI ALEXANDRIA PA 1429 DUKE ST, ALEXANDRIA, VA 22314 SN 0040-1706 J9 TECHNOMETRICS JI Technometrics PD MAY PY 1993 VL 35 IS 2 BP 109 EP 135 DI 10.2307/1269656 PG 27 WC Statistics & Probability SC Mathematics GA KZ169 UT WOS:A1993KZ16900001 ER PT J AU FRANK, IE FRIEDMAN, JH AF FRANK, IE FRIEDMAN, JH TI A STATISTICAL VIEW OF SOME CHEMOMETRICS REGRESSION TOOLS - RESPONSE SO TECHNOMETRICS LA English DT Discussion C1 STANFORD UNIV,DEPT STAT,STANFORD,CA 94305. STANFORD UNIV,STANFORD LINEAR ACCELERATOR CTR,STANFORD,CA 94305. RP FRANK, IE (reprint author), JERLL INC,STANFORD,CA 94305, USA. NR 3 TC 8 Z9 8 U1 0 U2 5 PU AMER STATISTICAL ASSOC PI ALEXANDRIA PA 1429 DUKE ST, ALEXANDRIA, VA 22314 SN 0040-1706 J9 TECHNOMETRICS JI Technometrics PD MAY PY 1993 VL 35 IS 2 BP 143 EP 148 DI 10.2307/1269659 PG 6 WC Statistics & Probability SC Mathematics GA KZ169 UT WOS:A1993KZ16900004 ER PT J AU VANWINKLE, W ROSE, KA CHAMBERS, RC AF VANWINKLE, W ROSE, KA CHAMBERS, RC TI INDIVIDUAL-BASED APPROACH TO FISH POPULATION-DYNAMICS - AN OVERVIEW SO TRANSACTIONS OF THE AMERICAN FISHERIES SOCIETY LA English DT Article AB Individual-based simulation modeling tracks the attributes of individual fish through time and aggregates them to generate insights into population function. By seeking to understand how fish of differing phenotypes respond to variations in physicochemical and biological environments, analysts hope to improve predictions of population trends. A review of eight accompanying papers highlights the promise and current limitations of the individual-based approach. Among the challenges to be faced are accurately representing feeding encounter rates, extending models to account for spatial heterogeneity and transgenerational responses, dealing with practical limits to the amount of data on individuals that can be measured and managed, more fully conceptionalizing natural processes, and acquiring appropriate field data with which to formulate and test the models. C1 HUNTSMAN MARINE SCI CTR,ST ANDREWS E0G 2X0,NB,CANADA. RP VANWINKLE, W (reprint author), OAK RIDGE NATL LAB,DIV ENVIRONM SCI,POB 2008,MS-6038,OAK RIDGE,TN 37831, USA. NR 15 TC 72 Z9 75 U1 1 U2 12 PU AMER FISHERIES SOC PI BETHESDA PA 5410 GROSVENOR LANE SUITE 110, BETHESDA, MD 20814-2199 SN 0002-8487 J9 T AM FISH SOC JI Trans. Am. Fish. Soc. PD MAY PY 1993 VL 122 IS 3 BP 397 EP 403 DI 10.1577/1548-8659(1993)122<0397:IBATFP>2.3.CO;2 PG 7 WC Fisheries SC Fisheries GA LR876 UT WOS:A1993LR87600011 ER PT J AU ROSE, KA COWAN, JH AF ROSE, KA COWAN, JH TI INDIVIDUAL-BASED MODEL OF YOUNG-OF-THE-YEAR STRIPED BASS POPULATION-DYNAMICS .1. MODEL DESCRIPTION AND BASE-LINE SIMULATIONS SO TRANSACTIONS OF THE AMERICAN FISHERIES SOCIETY LA English DT Article ID BLUEGILL LEPOMIS-MACROCHIRUS; MORONE-SAXATILIS; SMALLMOUTH BASS; LARVAL FISH; REACTIVE DISTANCE; POTOMAC ESTUARY; TEMPERATURE; GROWTH; SIZE; MORTALITY AB An individual-based model of population dynamics of age-0 striped bass Morone saxatilis is described and model predictions are analyzed. The model begins with spawning and simulates the daily growth and mortality of the progeny from each egg clutch as the fish develop through the life stages of egg, yolk-sac larva, feeding larva, and juvenile during their first year of life in a single, well-mixed compartment. Day of spawning and development rates of eggs and yolk-sac larvae depend on temperature. Daily growth of feeding individuals is represented by a bioenergetics equation, for which consumption is based on random encounters by individuals with different types of prey. Larvae feed on four zooplankton types and juveniles feed exclusively on size-classes of four benthic types. Mortality of eggs and yolk-sac larvae has both temperature-dependent and constant terms; mortality of feeding larvae and juveniles depends on an individual's weight and length. Most of the computations in the simulation involve determining the daily number of each prey type eaten by each striped bass. Model predictions of larval and juvenile densities, growth rates, and mortality rates were similar to values observed in the Potomac River. Larger mothers produce more and larger eggs, which lead to larger larvae at first feeding. Increasing first-feeding size from 5.0 to 5.5 mm caused a 4.5-fold increase in survival to age 1. Average growth rates during the first 15 d of feeding for larvae that would survive to age 1 were about 0.1 mm/d higher than the average of all larvae. Juveniles in the model appeared to die at random because both the rate and the degree of size-selective mortality decreased rapidly during the juvenile stage. The model represents feeding in detail: additional model refinements and analyses should focus on incorporating behavioral and phenotypic differences among individuals, spatial and temporal variability in temperature and prey, and further model corroboration. C1 UNIV SO ALABAMA,DEPT MARINE SCI,MOBILE,AL 36688. RP ROSE, KA (reprint author), OAK RIDGE NATL LAB,DIV ENVIRONM SCI,POB 2008,MS-6036,OAK RIDGE,TN 37831, USA. NR 94 TC 62 Z9 64 U1 1 U2 9 PU AMER FISHERIES SOC PI BETHESDA PA 5410 GROSVENOR LANE SUITE 110, BETHESDA, MD 20814-2199 SN 0002-8487 J9 T AM FISH SOC JI Trans. Am. Fish. Soc. PD MAY PY 1993 VL 122 IS 3 BP 415 EP 438 DI 10.1577/1548-8659(1993)122<0415:IBMOYO>2.3.CO;2 PG 24 WC Fisheries SC Fisheries GA LR876 UT WOS:A1993LR87600013 ER PT J AU COWAN, JH ROSE, KA RUTHERFORD, ES HOUDE, ED AF COWAN, JH ROSE, KA RUTHERFORD, ES HOUDE, ED TI INDIVIDUAL-BASED MODEL OF YOUNG-OF-THE-YEAR STRIPED BASS POPULATION-DYNAMICS .2. FACTORS AFFECTING RECRUITMENT IN THE POTOMAC RIVER, MARYLAND SO TRANSACTIONS OF THE AMERICAN FISHERIES SOCIETY LA English DT Article ID MORONE-SAXATILIS WALBAUM; SOUTHERN BLUEFIN TUNA; EARLY LIFE-HISTORY; CHESAPEAKE BAY; MARINE FISH; SPECULATIVE HYPOTHESIS; NATURAL MORTALITY; THUNNUS-MACCOYII; WATER-QUALITY; LARVAE AB An individual-based model of the population dynamics of young-of-the-year striped bass Morone saxatilis in the Potomac River, Maryland, was used to test the hypothesis that historically high recruitment variability can be explained by changes in environmental and biological factors that result in relatively small changes in growth and mortality rates of striped bass larvae. The four factors examined were (1) size distribution of female parents, (2) zooplankton prey density during the development of striped bass larvae, (3) density of competing larval white perch M. americana, and (4) temperature during larval development. Simulation results suggest that variations in female size and in prey for larvae alone could cause 10-fold variability in recruitment. But no single factor alone caused changes in vital rates of age-0 fish that could account for the 145-fold variability in the Potomac River index of juvenile recruitment. However, combined positive or negative effects of two or more factors resulted in more than a 150-fold simulated recruitment variability. suggesting that combinations of factors can account for the high observed annual variability in striped bass recruitment success. Higher cumulative mortality of feeding larvae and younger life stages than of juveniles was common to all simulations, supporting the contention that striped bass year-class strength is determined prior to metamorphosis. C1 OAK RIDGE NATL LAB,DIV ENVIRONM SCI,OAK RIDGE,TN 37831. UNIV MARYLAND SYST,CTR ENVIRONM & ESTUARINE STUDIES,CHESAPEAKE BIOL LAB,SOLOMONS,MD 20688. RP COWAN, JH (reprint author), UNIV SO ALABAMA,DEPT MARINE SCI,MOBILE,AL 36688, USA. RI Houde, Edward/D-8498-2012 NR 75 TC 34 Z9 35 U1 0 U2 7 PU AMER FISHERIES SOC PI BETHESDA PA 5410 GROSVENOR LANE SUITE 110, BETHESDA, MD 20814-2199 SN 0002-8487 J9 T AM FISH SOC JI Trans. Am. Fish. Soc. PD MAY PY 1993 VL 122 IS 3 BP 439 EP 458 DI 10.1577/1548-8659(1993)122<0439:IBMOYO>2.3.CO;2 PG 20 WC Fisheries SC Fisheries GA LR876 UT WOS:A1993LR87600014 ER PT J AU VANWINKLE, W ROSE, KA WINEMILLER, KO DEANGELIS, DL CHRISTENSEN, SW OTTO, RG SHUTER, BJ AF VANWINKLE, W ROSE, KA WINEMILLER, KO DEANGELIS, DL CHRISTENSEN, SW OTTO, RG SHUTER, BJ TI LINKING LIFE-HISTORY THEORY, ENVIRONMENTAL SETTING, AND INDIVIDUAL-BASED MODELING TO COMPARE RESPONSES OF DIFFERENT FISH SPECIES TO ENVIRONMENTAL-CHANGE SO TRANSACTIONS OF THE AMERICAN FISHERIES SOCIETY LA English DT Article ID SMALLMOUTH BASS; AMERICAN FISHES; POPULATIONS; PATTERNS; EXPLOITATION; RECRUITMENT; MANAGEMENT; BEHAVIOR; STYLES; SIZE AB We link life history theory, environmental setting, and individual-based modeling to compare the responses of two fish species to environmental change. Life history theory provides the framework for selecting representative species, and in combination with information on important environmental characteristics, it provides the framework for predicting the results of model simulations. Individual-based modeling offers a promising tool for integrating and extrapolating our mechanistic understanding of reproduction, growth, and mortality at the individual level to population-level responses such as size-frequency distributions and indices of year-class strength. Based on the trade-offs between life history characteristics of striped bass Morone saxatilis and smallmouth bass Micropterus dolomieu and differences in their respective environments, we predicted that young-of-year smallmouth bass are likely to demonstrate a greater compensatory change in growth and mortality than young-of-year striped bass in response to changes in density of early life stages and turnover rates of zooplankton prey. We tested this prediction with a simulation experiment. The pattern of model results was consistent with our expectations: by the end of the first growing season, compensatory changes in length and abundance of juveniles were more pronounced for smallmouth bass than for striped bass. The results also highlighted the dependence of model predictions on the interplay between density of larvae and juveniles and characteristics of their zooplankton prey. C1 RG OTTO & ASSOCIATES,VIENNA,MD 21869. ONTARIO MINIST NAT RESOURCES,FISHERIES RES SECT,MAPLE L6A 1S9,ON,CANADA. RP VANWINKLE, W (reprint author), OAK RIDGE NATL LAB,DIV ENVIRONM SCI,POB 2008,MS-6038,OAK RIDGE,TN 37831, USA. RI Shuter, Brian/A-3991-2008 NR 27 TC 28 Z9 29 U1 1 U2 17 PU AMER FISHERIES SOC PI BETHESDA PA 5410 GROSVENOR LANE SUITE 110, BETHESDA, MD 20814-2199 SN 0002-8487 J9 T AM FISH SOC JI Trans. Am. Fish. Soc. PD MAY PY 1993 VL 122 IS 3 BP 459 EP 466 DI 10.1577/1548-8659(1993)122<0459:LLHTES>2.3.CO;2 PG 8 WC Fisheries SC Fisheries GA LR876 UT WOS:A1993LR87600015 ER PT J AU RICE, JA CROWDER, LB ROSE, KA AF RICE, JA CROWDER, LB ROSE, KA TI INTERACTIONS BETWEEN SIZE-STRUCTURED PREDATOR AND PREY POPULATIONS - EXPERIMENTAL TEST AND MODEL COMPARISON SO TRANSACTIONS OF THE AMERICAN FISHERIES SOCIETY LA English DT Article ID PERCH PERCA-FLAVESCENS; LAKE-MICHIGAN; RECRUITMENT MECHANISMS; BLOATER; FISHES; MORTALITY; LARVAE; NICHE; SPOT AB Because predation mortality is often size-dependent. the survival and size structure of prey populations may vary substantially depending on the size structure of the predator assemblage. We tested this hypothesis in a replicated pond experiment in which a bimodal size distribution of young-of-year spot Leiostomus xanthurus was exposed to two sizes of southern flounder Paralichthys lethostigma, each predator size-group present alone or together, at densities providing equal predation pressure. After 3 weeks, we examined cohort survival and size distributions of remaining spot. In the no-predator controls, spot size-frequency distributions were essentially unchanged, and survival of the large- and small-spot cohorts was similar. However, the size distribution of survivors, and the relative survival of large- and small-spot cohorts, differed markedly with the size structure of the predator assemblage. In the presence of small southern flounders, the large-spot cohort survived 4 times better than the small-spot cohort. In the large-flounder-only treatment, small spot survived 2.4 times better than large spot. When both large and small southern flounders were present. large spot had a net advantage, exceeding small spot survival by 2.4 times. We developed an individual-based model of the flounder-spot size-dependent predation interaction based on data from independent laboratory observations on size-based prey profitability, and used it to simulate the results of our experimental treatments. Model predictions of spot survival and size distributions agreed well with the pond experimental results when encounter rates were assumed to scale with spot size and density and with southern flounder density. C1 OAK RIDGE NATL LAB,DIV ENVIRONM SCI,OAK RIDGE,TN 37831. RP RICE, JA (reprint author), N CAROLINA STATE UNIV,DEPT ZOOL,RALEIGH,NC 27695, USA. NR 37 TC 79 Z9 81 U1 2 U2 14 PU AMER FISHERIES SOC PI BETHESDA PA 5410 GROSVENOR LANE SUITE 110, BETHESDA, MD 20814-2199 SN 0002-8487 J9 T AM FISH SOC JI Trans. Am. Fish. Soc. PD MAY PY 1993 VL 122 IS 3 BP 481 EP 491 DI 10.1577/1548-8659(1993)122<0481:IBSSPA>2.3.CO;2 PG 11 WC Fisheries SC Fisheries GA LR876 UT WOS:A1993LR87600017 ER PT J AU GREENE, DL AF GREENE, DL TI TRANSPORTATION AND ENERGY - THE GLOBAL ENVIRONMENTAL CHALLENGE SO TRANSPORTATION RESEARCH PART A-POLICY AND PRACTICE LA English DT Article RP GREENE, DL (reprint author), OAK RIDGE NATL LAB,CTR TRANSPORTAT ANAL,OAK RIDGE,TN 37831, USA. NR 11 TC 2 Z9 2 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0965-8564 J9 TRANSPORT RES A-POL JI Transp. Res. Pt. A-Policy Pract. PD MAY PY 1993 VL 27 IS 3 BP 163 EP 166 DI 10.1016/0965-8564(93)90056-Q PG 4 WC Economics; Transportation; Transportation Science & Technology SC Business & Economics; Transportation GA LA527 UT WOS:A1993LA52700001 ER PT J AU GREENE, DL DULEEP, KG AF GREENE, DL DULEEP, KG TI COSTS AND BENEFITS OF AUTOMOTIVE FUEL-ECONOMY IMPROVEMENT - A PARTIAL ANALYSIS SO TRANSPORTATION RESEARCH PART A-POLICY AND PRACTICE LA English DT Article ID CAR AB This paper describes an exercise in estimating the costs and benefits of technology-based fuel economy improvements for automobiles and light trucks. Benefits quantified include vehicle costs, fuel savings, consumers' surplus effects, the effect of reduced weight on vehicle safety, impacts on emissions of CO2 and criteria pollutants, world oil market and energy security benefits, and the transfer of wealth from U.S. consumers to oil producers. A vehicle stock model represents sales, scrappage and vehicle use effects under three fuel price scenarios. Three alternative fuel economy levels for 2001 are considered, ranging from 32.9 to 36.5 miles per gallon (MPG) for cars and 24.2 to 27.5 MPG for light trucks. Overall, fuel economy improvements of this size are probably cost-effective. The size of the benefit, and even whether there is a benefit, strongly depends on the financial costs of fuel economy improvement and judgments about the values of energy security, emissions, safety, etc. Three sets of values for eight parameters are used to define the sensitivity of costs and benefits to key assumptions. The net present social value (1989$) of costs and benefits ranges from a cost of $11 billion to a benefit of $286 billion. The two largest components are always the direct vehicle costs and fuel savings, but these tend to counterbalance each other for the fuel economy levels examined here. Other major components are the wealth transfer, oil cost savings, CO2 emissions reductions, and energy security benefits. Safety impacts, emissions of criteria pollutants and consumers' surplus effects are relatively minor components. C1 ENERGY & ENVIRONM ANAL INC,ARLINGTON,VA 22209. RP GREENE, DL (reprint author), OAK RIDGE NATL LAB,CTR TRANSPORTAT ANAL,POB 2008,OAK RIDGE,TN 37831, USA. NR 56 TC 20 Z9 20 U1 1 U2 6 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0965-8564 J9 TRANSPORT RES A-POL JI Transp. Res. Pt. A-Policy Pract. PD MAY PY 1993 VL 27 IS 3 BP 217 EP 235 DI 10.1016/0965-8564(93)90061-O PG 19 WC Economics; Transportation; Transportation Science & Technology SC Business & Economics; Transportation GA LA527 UT WOS:A1993LA52700006 ER PT J AU LUXMOORE, RJ CUNNINGHAM, M MANN, LK TJOELKER, MG AF LUXMOORE, RJ CUNNINGHAM, M MANN, LK TJOELKER, MG TI UREA FERTILIZATION EFFECTS ON NUTRIENT-UPTAKE AND GROWTH OF PLATANUS-OCCIDENTALIS DURING PLANTATION ESTABLISHMENT SO TREES-STRUCTURE AND FUNCTION LA English DT Article DE MANGANESE-NUTRIENT UPTAKE; PLATANUS-OCCIDENTALIS; AMERICAN SYCAMORE; ROOT GROWTH-UREA AB The benefit of fertilizer application during establishment of a tree plantation depends on effective nutrient uptake and the utilization of the nutrients in growth. Five urea treatments (0, 50, 75, 150, and 450 kg N/ha) were applied in a completely randomized plot design to a field planted with American sycamore (Platanus occidentalis L.) seedlings to evaluate growth responses and nitrogen use efficiency during the first season of plantation establishment. The site was in the Oak Ridge Reservation in eastern Tennessee on a highly weathered soil. Harvests were conducted on 3 occasions during a 22 week experimental period, and dry weights of stems, leaves, and large and small roots were measured. Chemical analyses were conducted on plant tissues from the 0, 75, and 450 kg N/ha treatments. Plant dry weight increased with urea application and growth analysis showed that this was mainly associated with increase in leaf area and to a minor extent with increase in net assimilation rate. Root weight increased significantly with urea application. The specific absorption rate of roots for several nutrients was greater at higher urea levels for the first 2 harvest periods, but this pattern reversed during the 3rd growth period. Surprisingly, manganese uptake and the specific absorption rate for manganese were enhanced with higher urea application. The acidifying effect of urea nitrification is a likely explanation for the increased Mn availability, and nitrate leaching and/or nitrogen immobilization contributed to low uptake of urea-N by the seedlings. The proportion of the applied nitrogen incorporated into the seedlings was 1.5 and 0.6% for the 75 and 450 kg N/ha urea treatments, respectively. Broadcast fertilizer application is not an effective way of supplying nutrients to seedlings during plantation establishment. RP LUXMOORE, RJ (reprint author), OAK RIDGE NATL LAB,DIV ENVIRONM SCI,OAK RIDGE,TN 37831, USA. RI Tjoelker, Mark/M-2413-2016 OI Tjoelker, Mark/0000-0003-4607-5238 NR 0 TC 5 Z9 5 U1 0 U2 1 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 SN 0931-1890 J9 TREES-STRUCT FUNCT JI Trees-Struct. Funct. PD MAY PY 1993 VL 7 IS 4 BP 250 EP 257 PG 8 WC Forestry SC Forestry GA LD793 UT WOS:A1993LD79300010 ER PT J AU FOERSTER, CL HALAMA, H KORN, G CALDERON, M BARLETTA, W AF FOERSTER, CL HALAMA, H KORN, G CALDERON, M BARLETTA, W TI DESORPTION MEASUREMENTS OF COPPER AND COPPER-ALLOYS FOR PEP-II SO VACUUM LA English DT Article; Proceedings Paper CT 12TH INTERNATIONAL VACUUM CONGRESS ( IVC-12 ) / 8TH INTERNATIONAL CONF ON SOLID SURFACES ( ICSS-8 ) CY OCT 12-16, 1992 CL THE HAGUE, NETHERLANDS SP INT UNION VACUUM SCI TECH & APPLICAT, NETHERLANDS VACUUM SOC AB PEP-II will be a meson factory circulating asymmetric beams of 9 GeV and 3.1 GeV having maximum currents of 3.0 A. Copper beam chambers and absorbers will intercept resulting synchrotron radiation and it is critical that the dynamic gas load from photo stimulated desorption (PSD) and thermal outgassing is below 2 x 10(-6) molecules per photon. An experiment was set up to measure PSD from 1 m long bar samples and a chamber sample, fabricated from selected copper and copper alloys, then exposed to white light with a critical energy of 500 eV, on beamline U10B at the VUV ring of the National Synchrotron Light Source (NSLS). Based on U10B results a prototype chamber was built and will be exposed to white light with higher critical energies of up to 5 keV, on beamline X-28A at the X-ray ring of the NSLS. This paper presents the measurements of H-2, CO, CO2 and CH, desorption yields as function of accumulated photon flux, angle of incidence, sample material, and surface condition. The results are compared with that of previous work on similar materials and with that of others for copper. C1 LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94551. RP FOERSTER, CL (reprint author), BROOKHAVEN NATL LAB,NSLS BLDG 725C,UPTON,NY 11973, USA. NR 5 TC 3 Z9 3 U1 1 U2 2 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0042-207X J9 VACUUM JI Vacuum PD MAY-JUL PY 1993 VL 44 IS 5-7 BP 489 EP 491 DI 10.1016/0042-207X(93)90079-P PG 3 WC Materials Science, Multidisciplinary; Physics, Applied SC Materials Science; Physics GA LC574 UT WOS:A1993LC57400019 ER PT J AU GABUSI, J GELLER, J HSEUH, HC MAPES, M STATTEL, P AF GABUSI, J GELLER, J HSEUH, HC MAPES, M STATTEL, P TI PRESSURE MEASUREMENTS IN THE AGS BOOSTER ULTRA-HIGH VACUUM-SYSTEM SO VACUUM LA English DT Article; Proceedings Paper CT 12TH INTERNATIONAL VACUUM CONGRESS ( IVC-12 ) / 8TH INTERNATIONAL CONF ON SOLID SURFACES ( ICSS-8 ) CY OCT 12-16, 1992 CL THE HAGUE, NETHERLANDS SP INT UNION VACUUM SCI TECH & APPLICAT, NETHERLANDS VACUUM SOC AB An average pressure of mid 10(-11) torr has been achieved and maintained in the AGS Booster ring vacuum system during its first year of operation. This ultra-high vacuum system is monitored through remote controlled Bayard-Alpert Gages (BAGs). The characteristics of the pressure measurements with BAGs over the long cable lengths (up to 200 m) and under various accelerator operating conditions will be described. Two types of noise in the pressure readouts have been identified; the electromagnetic interference (EMI) associated with the acceleration cycles of the Booster and the environment noise associated with the solar heating of the collector cables. The magnitude of the noise pickup depends on the routing of the collector cables and reaches the equivalent pressure of low 10(-9) torr. RP GABUSI, J (reprint author), BROOKHAVEN NATL LAB,DEPT AGS,UPTON,NY 11973, USA. NR 5 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 0042-207X J9 VACUUM JI Vacuum PD MAY-JUL PY 1993 VL 44 IS 5-7 BP 527 EP 530 DI 10.1016/0042-207X(93)90088-R PG 4 WC Materials Science, Multidisciplinary; Physics, Applied SC Materials Science; Physics GA LC574 UT WOS:A1993LC57400028 ER PT J AU MAKHOV, AM TRUS, BL CONWAY, JF SIMON, MN ZURABISHVILI, TG MESYANZHINOV, VV STEVEN, AC AF MAKHOV, AM TRUS, BL CONWAY, JF SIMON, MN ZURABISHVILI, TG MESYANZHINOV, VV STEVEN, AC TI THE SHORT TAIL-FIBER OF BACTERIOPHAGE-T4 - MOLECULAR-STRUCTURE AND A MECHANISM FOR ITS CONFORMATIONAL TRANSITION SO VIROLOGY LA English DT Article ID ELECTRON-MICROSCOPY; SECONDARY STRUCTURE; ADENOVIRUS FIBER; PROTEIN; IMAGES; SEQUENCE; MACROMOLECULES; PREDICTION; REOVIRUS C1 NIAMSD,STRUCT BIOL LAB,BLDG 6,ROOM 114,BETHESDA,MD 20892. NIH,DIV COMP RES & TECHNOL,BETHESDA,MD 20892. BROOKHAVEN NATL LAB,DEPT BIOL,UPTON,NY 10973. DI IVANOVSKII INST VIROL,MOSCOW 123098,RUSSIA. RI Conway, James/A-2296-2010 OI Conway, James/0000-0002-6581-4748 NR 42 TC 46 Z9 48 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 0042-6822 J9 VIROLOGY JI Virology PD MAY PY 1993 VL 194 IS 1 BP 117 EP 127 DI 10.1006/viro.1993.1241 PG 11 WC Virology SC Virology GA KY344 UT WOS:A1993KY34400014 PM 8480415 ER PT J AU BOOPATHY, R WILSON, M KULPA, CF AF BOOPATHY, R WILSON, M KULPA, CF TI ANAEROBIC REMOVAL OF 2,4,6-TRINITROTOLUENE (TNT) UNDER DIFFERENT ELECTRON-ACCEPTING CONDITIONS - LABORATORY STUDY SO WATER ENVIRONMENT RESEARCH LA English DT Note DE ANAEROBIC PROCESS; BIOTRANSFORMATION; DECONTAMINATION; ELECTRON ACCEPTORS; ELECTRON DONORS; REDUCTION PROCESS; 2,4,6-TRINITROTOLUENE (TNT) ID MICROBIAL TRANSFORMATION; METHANOGENIC BACTERIA AB An attempt has been made to study the anaerobic removal of 2,4,6-trinitrotoluene (TNT) under different electron accepting conditions by a soil bacterial consortium. The results indicated that among the different electron acceptors studied (sulfate, nitrate, and carbon dioxide), significant TNT removal was observed under nitrate reducing conditions. When them was no electron acceptor in the medium, TNT was not removed even after 60 days of incubation. Under nitrate reducing conditions, 82% of TNT was removed from the original concentration of 100 ppm of TNT. Under sulfate reducing conditions, approximately 30% of TNT was removed. When carbon dioxide was used as electron acceptor and H-2 as electron donor, TNT was removed by 35%. This result indicates that TNT could be removed under anaerobic conditions when there is appropriate and adequate electron acceptor present in the soil. TNT did not serve as an electron acceptor and TNT removal was apparently achieved by co-metabolism. The anaerobic reactions demonstrate that decontamination of TNT is possible under anaerobic conditions for TNT contaminated sites of soil and water, where aerobic treatment is not economically feasible. C1 UNIV NOTRE DAME,DEPT BIOL SCI,NOTRE DAME,IN 46556. RP BOOPATHY, R (reprint author), ARGONNE NATL LAB,DIV ENVIRONM RES,BLDG 203,ARGONNE,IL 60439, USA. NR 24 TC 57 Z9 57 U1 0 U2 7 PU WATER ENVIRONMENT FEDERATION PI ALEXANDRIA PA 601 WYTHE ST, ALEXANDRIA, VA 22314-1994 SN 1061-4303 J9 WATER ENVIRON RES JI Water Environ. Res. PD MAY-JUN PY 1993 VL 65 IS 3 BP 271 EP 275 PG 5 WC Engineering, Environmental; Environmental Sciences; Limnology; Water Resources SC Engineering; Environmental Sciences & Ecology; Marine & Freshwater Biology; Water Resources GA LK982 UT WOS:A1993LK98200012 ER PT J AU WANG, BQ GENG, GQ LEVY, AV AF WANG, BQ GENG, GQ LEVY, AV TI EFFECT OF MICROSTRUCTURE ON MATERIAL WASTAGE IN A ROOM-TEMPERATURE FLUIDIZED-BED WEAR-TEST RIG SO WEAR LA English DT Article ID EROSION AB Rod-shaped 1018 steel specimens were prepared in four different microstructure conditions, i.e. annealed, normalized, cold-drawn and as-quenched. A unique laboratory-scale fluidized-bed erosion-wear test apparatus was operated at room temperature to study the influence of the microstructure of the steel specimens on metal wastage. 800 mum angular quartz (SiO2) particles were used as the bed material. The mass and circumferential thickness change distributions of the specimen rods were determined. The morphologies of the specimens were examined by scanning electron microscopy (SEM) and the microhardness of the surface of the specimens was measured. It was determined that the harder and more homogeneous the morphology of the steel, the lower the metal wastage. There was a different relationship between the microstructure of the steel and metal wastage from that which occurs in erosion tests using a blast nozzle tester at higher particle velocities, i.e. greater than or equal to 10 m s-1. Testing in the nozzle tester at higher particle velocities and resultant impact forces, the erosion metal wastage is related to the distribution of hard, brittle phases in a softer metal matrix and is not related to its hardness. The thickness change profiles around the periphery of the four different treated 1018 steel rods were very similar. The locations of maximum thickness losses were at 144-degrees and 216-degrees from top center, 0-degrees. This distribution was independent of the microstructure of the specimens. C1 LAWRENCE BERKELEY LAB,BERKELEY,CA 94720. RP WANG, BQ (reprint author), XIAN HIGHWAY TRANSPORTAT UNIV,SHAANXI,PEOPLES R CHINA. NR 16 TC 4 Z9 4 U1 0 U2 3 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE 1 PA PO BOX 564, 1001 LAUSANNE 1, SWITZERLAND SN 0043-1648 J9 WEAR JI Wear PD MAY 1 PY 1993 VL 165 IS 1 BP 25 EP 33 PG 9 WC Engineering, Mechanical; Materials Science, Multidisciplinary SC Engineering; Materials Science GA LC185 UT WOS:A1993LC18500004 ER PT J AU DAVID, SA ZACHARIA, T AF DAVID, SA ZACHARIA, T TI WELDABILITY OF FE3AL-TYPE ALUMINIDE SO WELDING JOURNAL LA English DT Article DE WELDABILITY TESTING; FE3AL-TYPE ALUMINIDE; AUTOGENOUS WELDS; GTAW; ELECTRON BEAM WELD; HOT CRACKING; COLD CRACKING; THRESHOLD STRESSES; SIGMAJIG TESTING; INTERMETALLIC ALLOYS ID IRON ALUMINIDES; ORDERED ALLOYS; METALLURGY; NI3AL AB An investigation was carried out to determine the weldability of a series of Fe3Al-type alloys. Autogenous welds were made on thin sheets of iron aluminide alloys using gas tungsten arc (GTA) and electron beam (EB) welding processes at different travel speeds and power levels. The results indicate that although these alloys can be successfully welded using the EB welding process, some compositions may hot crack during GTA welding. Boron and zirconium additions have been found to promote hot cracking in these alloys. Among the alloys investigated, Fe3Al modified with chromium, niobium and carbon (FA-129) showed the most promise for good weldability. Hot-cracking severity of this alloy was further investigated using the Sigmajig test. The minimum threshold stress of 25 ksi measured is within the material range of other aluminides and some commercial stainless steels. Also, some of these alloys exhibited a tendency for cold cracking. This is related to severe hydrogen embrittlement associated with this class of alloys. RP DAVID, SA (reprint author), OAK RIDGE NATL LAB,DIV MET & CERAM,OAK RIDGE,TN 37831, USA. NR 39 TC 8 Z9 9 U1 0 U2 2 PU AMER WELDING SOC PI MIAMI PA PO BOX 351040, MIAMI, FL 33135 SN 0043-2296 J9 WELD J JI Weld. J. PD MAY PY 1993 VL 72 IS 5 BP S201 EP S207 PG 7 WC Metallurgy & Metallurgical Engineering SC Metallurgy & Metallurgical Engineering GA LA120 UT WOS:A1993LA12000015 ER PT J AU LUNDIN, CD QIAO, CYP GILL, TPS GOODWIN, GM AF LUNDIN, CD QIAO, CYP GILL, TPS GOODWIN, GM TI HOT DUCTILITY AND HOT CRACKING BEHAVIOR OF MODIFIED 316 STAINLESS-STEELS DESIGNED FOR HIGH-TEMPERATURE SERVICE SO WELDING JOURNAL LA English DT Article DE HOT DUCTILITY; HOT CRACKING; MODIFIED 316 SS; HIGH TEMP SERVICE; AUSTENITIC SS; GLEEBLE TESTING; VARESTRAINT TESTING; SIGMAJIG TESTING; TESTING TESTING CRITERIA; HAZ CRACKING AB The weldability of the modified 316 stainless steel was evaluated by the Gleeble hot ductility test and two hot cracking test methods (Varestraint and Sigmajig). The fusion zone and weld metal heat-affected zone (HAZ) hot cracking susceptibilities of the modified 316 stainless steel are similar to conventional fully austenitic 316 stainless steels and greater than the conventional 316 materials that have a primary ferritic solidification mode. The Gleeble hot ductility test results correlate with the base metal HAZ hot cracking results from the Varestraint test and indicate that the modified 316 materials show a considerably higher base metal HAZ hot cracking susceptibility as contrasted to nuclear grade 316 stainless steels. Varestraint test results and Sigmajig test results for the tested materials showed good correlations. The sensitivity of the base metal to HAZ liquation cracking has been successfully predicted by using a newly developed hot ductility criterion, the ratio of ductility recovery (RDR). An excellent correlation between the Gleeble Test criterion RDR and the Varestraint Test criteria (TCL, MCL and CHL) has been found. C1 OAK RIDGE NATL LAB,DIV MET & CERAM,OAK RIDGE,TN 37831. RP LUNDIN, CD (reprint author), UNIV TENNESSEE,DEPT MAT SCI & ENGN,KNOXVILLE,TN 37996, USA. NR 16 TC 4 Z9 4 U1 0 U2 0 PU AMER WELDING SOC PI MIAMI PA PO BOX 351040, MIAMI, FL 33135 SN 0043-2296 J9 WELD J JI Weld. J. PD MAY PY 1993 VL 72 IS 5 BP S189 EP S200 PG 12 WC Metallurgy & Metallurgical Engineering SC Metallurgy & Metallurgical Engineering GA LA120 UT WOS:A1993LA12000014 ER PT J AU SMARTT, HB EINERSON, CJ AF SMARTT, HB EINERSON, CJ TI A MODEL FOR HEAT AND MASS INPUT CONTROL IN GMAW SO WELDING JOURNAL LA English DT Article DE GMAW; CONTROL MODEL; WELDING SPEED; HEAT AND MASS INPUT; REINFORCEMENT AREA; COMPUTER CONTROL; PI CONTROLLER; DIGITAL FILTER; FEEDBACK CONTROL AB This work describes derivation of a control model for electrode melting and heat and mass transfer from the electrode to the workpiece in gas metal arc welding (GMAW). Specifically, a model is developed which allows electrode speed and welding speed to be calculated for given values of voltage and torch-to-base metal distance, as a function of the desired heat and mass input to the weldment. Heat input is given on a per unit weld length basis, and mass input is given in terms of transverse cross-sectional area added to the weld bead (termed reinforcement). The relationship to prior work is discussed. The model was demonstrated using a computer-controlled welding machine and a proportional-integral (PI) controller receiving input from a digital filter. The difference between model-calculated welding current and measured current is used as controller feedback. The model is calibrated for use with carbon steel welding wire and base plate with Ar-CO2 shielding gas. Although the system is intended for application during spray transfer of molten metal from the electrode to the weld pool, satisfactory performance is also achieved during globular and streaming transfer. Data are presented showing steady-state and transient performance, as well as resistance to external disturbances. RP SMARTT, HB (reprint author), EG&G IDAHO INC,IDAHO NATL ENGN LAB,IDAHO FALLS,ID 83401, USA. NR 15 TC 8 Z9 8 U1 0 U2 2 PU AMER WELDING SOC PI MIAMI PA PO BOX 351040, MIAMI, FL 33135 SN 0043-2296 J9 WELD J JI Weld. J. PD MAY PY 1993 VL 72 IS 5 BP S217 EP S229 PG 13 WC Metallurgy & Metallurgical Engineering SC Metallurgy & Metallurgical Engineering GA LA120 UT WOS:A1993LA12000017 ER PT J AU BOTVINA, A MISHUSTIN, IN BLANN, M MUSTAFA, MG PEILERT, G STOCKER, H GREINER, W AF BOTVINA, A MISHUSTIN, IN BLANN, M MUSTAFA, MG PEILERT, G STOCKER, H GREINER, W TI MECHANISMS OF FRAGMENT PRODUCTION IN HEAVY-ION REACTIONS AT INTERMEDIATE ENERGIES SO ZEITSCHRIFT FUR PHYSIK A-HADRONS AND NUCLEI LA English DT Article ID INTRANUCLEAR CASCADE CALCULATION; HIGHLY EXCITED NUCLEI; STATISTICAL MULTIFRAGMENTATION; MICROSCOPIC CALCULATIONS; BREAK-UP; COLLISIONS; MODEL; DECAY; FLOW; MATTER AB Comparative analysis of three typical models of nuclear disintegration, the statistical multifragmentation model (SMM), the quantum statistical model (QSM) and a generalized evaporation model (GEM), is carried out. The thermodynamical properties of a decaying system as well as observable characteristics in heavy ion collisions predicted by the different models are discussed. It is shown that these models yield quite similar results for low charge yields at higher excitation energies (EIA > 6 MeV per nucleon) and it is suggested that the coincidence measurements of the intermediate mass fragment multiplicity and the neutron and proton multiplicity (or alternatively, the total bound charge) may be very useful for deducing the decay mechanism. The GEM is shown to differ from the other models in predicting a high Z residue peak. C1 RUSSIAN SCI CTR,KURCHATOV INST,MOSCOW 123182,RUSSIA. LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550. UNIV FRANKFURT,INST THEORET PHYS,W-6000 FRANKFURT,GERMANY. RP BOTVINA, A (reprint author), RUSSIAN ACAD SCI,INST NUCL RES,MOSCOW 117312,RUSSIA. RI Stoecker, Horst/D-6173-2013 OI Stoecker, Horst/0000-0002-3282-3664 NR 55 TC 14 Z9 14 U1 0 U2 0 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 SN 0939-7922 J9 Z PHYS A-HADRON NUCL JI Z. Phys. A.-Hadrons Nuclei PD MAY PY 1993 VL 345 IS 3 BP 297 EP 303 DI 10.1007/BF01280837 PG 7 WC Physics, Nuclear; Physics, Particles & Fields SC Physics GA LC924 UT WOS:A1993LC92400007 ER PT J AU AMSLER, C ARMSTRONG, DS AUGUSTIN, I BAKER, CA BARNETT, BM BATTY, CJ BEUCHERT, K BIRIEN, P BISTIRLICH, J BLUM, P BOSSINGHAM, R BOSSY, H BRAUNE, K BROSE, J BUGG, DV BURCHELL, M CASE, T CHUNG, SU COOPER, A CROWE, KM DIETZ, HP VONDOMBROWSKI, S DOSER, M DUNNWEBER, W ENGELHARDT, D ENGLERT, M FAESSLER, MA FELIX, C FOLGER, G HACKMANN, R HADDOCK, RP HEINSIUS, FH HESSEY, NP HIDAS, P ILLINGER, P JAMNIK, D JAVORFI, Z KALINOWSKY, H KAMMLE, B KIEL, T KISIEL, J KLEMPT, E KOBEL, M KOCH, H KOLO, C KONIGSMANN, K KUNZE, M LANDUA, R LUDEMANN, J MATTHAEY, H MERKEL, M MERLO, JP MEYER, CA MEYERBERKHOUT, U MONTANET, L NOBLE, A OULDSAADA, F PETERS, K PINTER, G RAVNDAL, S SANJARI, AH SCHAFER, E SCHMID, B SCHMIDT, P SPANIER, S STRASSBURGER, C STROHBUSCH, U SUFFERT, M URNER, D VOLCKER, C WALTER, F WALTHER, D WIEDNER, U WINTER, N ZOLL, J ZUPANCIC, C AF AMSLER, C ARMSTRONG, DS AUGUSTIN, I BAKER, CA BARNETT, BM BATTY, CJ BEUCHERT, K BIRIEN, P BISTIRLICH, J BLUM, P BOSSINGHAM, R BOSSY, H BRAUNE, K BROSE, J BUGG, DV BURCHELL, M CASE, T CHUNG, SU COOPER, A CROWE, KM DIETZ, HP VONDOMBROWSKI, S DOSER, M DUNNWEBER, W ENGELHARDT, D ENGLERT, M FAESSLER, MA FELIX, C FOLGER, G HACKMANN, R HADDOCK, RP HEINSIUS, FH HESSEY, NP HIDAS, P ILLINGER, P JAMNIK, D JAVORFI, Z KALINOWSKY, H KAMMLE, B KIEL, T KISIEL, J KLEMPT, E KOBEL, M KOCH, H KOLO, C KONIGSMANN, K KUNZE, M LANDUA, R LUDEMANN, J MATTHAEY, H MERKEL, M MERLO, JP MEYER, CA MEYERBERKHOUT, U MONTANET, L NOBLE, A OULDSAADA, F PETERS, K PINTER, G RAVNDAL, S SANJARI, AH SCHAFER, E SCHMID, B SCHMIDT, P SPANIER, S STRASSBURGER, C STROHBUSCH, U SUFFERT, M URNER, D VOLCKER, C WALTER, F WALTHER, D WIEDNER, U WINTER, N ZOLL, J ZUPANCIC, C TI ANTIPROTON-PROTON ANNIHILATION AT REST INTO 2-BODY FINAL-STATES SO ZEITSCHRIFT FUR PHYSIK C-PARTICLES AND FIELDS LA English DT Article ID QUARK-LINE RULE; PBARP ANNIHILATION; 2 MESONS; P-STATES; ETA; HYDROGEN; MODEL; PI+PI; PI-0; GAS AB We report measurements of branching ratios for production of a series of two meson final states in ppBAR annihilations at rest in liquid hydrogen. We find: BR(ppBAR-->pi+pi-) = (3.07 +/- 0.13) . 10(-3) BR(ppBAR-->K+K-) = (0.99 +/- 0.05) . 10(-3) BR(ppBAR-->pi0pi0) = (6.93 +/- 0.43) . 10(-4) BR(ppBAR-->pi0eta) = (2.12 +/- 0.12) . 10(-4) BR(ppBAR-->pi0omega) = (5.73 +/- 0.47) . 10(-3) BR(ppBAR-->pi0eta') = (1.23 +/- 0.13) . 10(-4) BR(ppBAR-->etaeta) = (1.64 +/- 0.10) . 10(-4) BR(ppBAR-->etaomega) = (1.51 +/- 0.12) . 10(-2) BR(ppBAR-->etaeta') = (2.16 +/- 0.25) . 10(-4) BR(ppBAR-->omegaomega) = (3.32 +/- 0.34) . 10(-2) BR(ppBAR-->(omegaeta') = (0.78 +/- 0.08) . 10(-2) These are the first measurements of the channels etaeta' and omegaeta' and in almost all the other channels are more precise than previous results. We also obtain, in a more precise fashion, the following ratios of branching ratios: K+K-/pi+pi- = 0.323 +/- 0.013, pi0eta'/pi0eta = 0.548 +/- 0.056, etaeta'/etaeta = 1.31 +/- 0.15, omegaeta'/omegaeta = 0.515 +/- 0.040, pi0eta/pi0pi0 = 0.303 +/- 0.010, etaeta/pi0pi0 = 0.232 +/- 0.011 and pi0omega/etaomega = 0.377 +/- 0.012. The measurements are made for different eta and eta' decays, and we thus obtain GAMMA(eta-->3pi0)/GAMMA(eta-->gammagamma) = 0.841 +/- 0.034, and GAMMA(eta'-->gammagamma)/GAMMA(eta'-->pi0pi0pi) = 0.091 +/- 0.009. C1 LAWRENCE BERKELEY LAB,BERKELEY,CA 94720. RUHR UNIV BOCHUM,W-4630 BOCHUM,GERMANY. HUNGARIAN ACAD SCI,H-1525 BUDAPEST,HUNGARY. RUTHERFORD APPLETON LAB,DIDCOT OX11 0QX,OXON,ENGLAND. CERN,CH-1211 GENEVA,SWITZERLAND. UNIV HAMBURG,W-2000 HAMBURG 13,GERMANY. UNIV KARLSRUHE,W-7500 KARLSRUHE,GERMANY. QUEEN MARY & WESTFIELD COLL,LONDON E1 4NS,ENGLAND. UNIV CALIF LOS ANGELES,LOS ANGELES,CA 90024. UNIV MAINZ,W-6500 MAINZ,GERMANY. UNIV MUNICH,W-8000 MUNICH 2,GERMANY. CTR RECH NUCL,F-67037 STRASBOURG,FRANCE. RP AMSLER, C (reprint author), UNIV ZURICH,CH-8001 ZURICH,SWITZERLAND. OI Burchell, Mark/0000-0002-2680-8943; Meyer, Curtis/0000-0001-7599-3973 NR 46 TC 94 Z9 94 U1 0 U2 2 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 SN 0170-9739 J9 Z PHYS C PART FIELDS JI Z. Phys. C-Part. Fields PD MAY PY 1993 VL 58 IS 2 BP 175 EP 189 PG 15 WC Physics, Particles & Fields SC Physics GA LA858 UT WOS:A1993LA85800001 ER PT J AU AKESSON, T ALMEHED, S ANGELIS, ALS ATHERTON, H AUBRY, P BARTEL, HW BEAUDOIN, G BEAULIEU, JM BEKER, H BENARY, O BETTONI, D BISI, V BLEVIS, I BOGGILD, H CLELAND, W CLEMEN, M COLLICK, B CORRIVEAU, F DAGAN, S DEDERICHS, K DELLUOMO, S DEPOMMIER, P DEVENISH, RCE DIGIACOMO, N DILIBERTO, S DODD, JR DOLGOSHEIN, B DREES, A ENYO, H ERLANDSON, B ESTEN, MJ FABJAN, CW FISCHER, P FRAENKEL, Z GAIDOT, A GIBRATDEBU, F GIUBELLINO, P GLASSEL, P GOERLACH, U HAGLUND, R HAMEL, LA VANHECKE, H HEDBERG, V HEIFETZ, R HOLSCHER, A JACAK, B JARLSKOG, G JOHANSSON, S KRANER, H KROH, V LAMARCHE, F LEROY, C LISSAUER, D LONDON, G LORSTAD, B LOUNIS, A MARTELLI, F MARZARICHIESA, A MASERA, M MAZZONI, MA MAZZUCATO, E MCCUBBIN, NA MCGAUGHEY, P MEDDI, F MJORNMARK, U MUCIACCIA, MT MURAVIEV, S MURRAY, M NEUBERT, M NILSSON, S OLSEN, L OREN, Y PANSART, JP PARK, YM PFEIFFER, A PIUZ, F POLYCHRONAKOS, V POULARD, G PRICE, M RAHM, D RAMELLO, L RICCATI, L ROMANO, G ROSA, G SANDOR, L SCHUKRAFT, J SEKIMOTO, M SELLDEN, B SEMAN, M SHMELEVA, A SIDOROV, V SIMONE, S SIROIS, Y SLETTEN, H SMIRNOV, S SONDHEIM, W SPECHT, HJ STERN, M STUMER, I SUNIER, JW TCHERNIATIN, V THODBERG, HH THOMPSON, J TIKHOMIROV, V TSERRUYA, I VASSEUR, G VEENHOF, R WIGMANS, R YEPES, P AF AKESSON, T ALMEHED, S ANGELIS, ALS ATHERTON, H AUBRY, P BARTEL, HW BEAUDOIN, G BEAULIEU, JM BEKER, H BENARY, O BETTONI, D BISI, V BLEVIS, I BOGGILD, H CLELAND, W CLEMEN, M COLLICK, B CORRIVEAU, F DAGAN, S DEDERICHS, K DELLUOMO, S DEPOMMIER, P DEVENISH, RCE DIGIACOMO, N DILIBERTO, S DODD, JR DOLGOSHEIN, B DREES, A ENYO, H ERLANDSON, B ESTEN, MJ FABJAN, CW FISCHER, P FRAENKEL, Z GAIDOT, A GIBRATDEBU, F GIUBELLINO, P GLASSEL, P GOERLACH, U HAGLUND, R HAMEL, LA VANHECKE, H HEDBERG, V HEIFETZ, R HOLSCHER, A JACAK, B JARLSKOG, G JOHANSSON, S KRANER, H KROH, V LAMARCHE, F LEROY, C LISSAUER, D LONDON, G LORSTAD, B LOUNIS, A MARTELLI, F MARZARICHIESA, A MASERA, M MAZZONI, MA MAZZUCATO, E MCCUBBIN, NA MCGAUGHEY, P MEDDI, F MJORNMARK, U MUCIACCIA, MT MURAVIEV, S MURRAY, M NEUBERT, M NILSSON, S OLSEN, L OREN, Y PANSART, JP PARK, YM PFEIFFER, A PIUZ, F POLYCHRONAKOS, V POULARD, G PRICE, M RAHM, D RAMELLO, L RICCATI, L ROMANO, G ROSA, G SANDOR, L SCHUKRAFT, J SEKIMOTO, M SELLDEN, B SEMAN, M SHMELEVA, A SIDOROV, V SIMONE, S SIROIS, Y SLETTEN, H SMIRNOV, S SONDHEIM, W SPECHT, HJ STERN, M STUMER, I SUNIER, JW TCHERNIATIN, V THODBERG, HH THOMPSON, J TIKHOMIROV, V TSERRUYA, I VASSEUR, G VEENHOF, R WIGMANS, R YEPES, P TI TRANSVERSE ENERGY MEASUREMENTS IN PROTON-NUCLEUS INTERACTIONS AT HIGH-ENERGY SO ZEITSCHRIFT FUR PHYSIK C-PARTICLES AND FIELDS LA English DT Article ID COLLISIONS AB The results of two sets of transverse energy measurements, performed with incident proton beams of 200 and 450 GeV/c momentum on several nuclear targets, are presented. The transverse energy cross sections dsigma/dE(T) are measured in a pseudorapidity range including the target fragmentation region (- 0.1 < eta < 2.9) for both data sets and also in a nearly complete pseudorapidity coverage (- 0.1 < eta < 5.5) for the data taken at 200 GeV/c incident momentum. A comparison is made of the transverse energy distributions in the target fragmentation region and in the full eta region. We find that the mean value of pseudorapidity of the dE(T)/deta distributions shifts towards the target fragmentation region as the atomic mass number of the target increases or a selection of high transverse energy events is made. A parametrization based on a simple geometrical nucleon-nucleon scattering approach was found to be inadequate to describe all features of the transverse energy distributions. Finally, the VENUS model is compared with the experimental data. C1 UNIV BARI,I-70126 BARI,ITALY. INFN,I-70100 BARI,ITALY. BROOKHAVEN NATL LAB,UPTON,NY 11973. UNIV HEIDELBERG,W-6900 HEIDELBERG,GERMANY. LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87544. UNIV LUND,S-22362 LUND,SWEDEN. MCGILL UNIV,MONTREAL H3A 2T8,QUEBEC,CANADA. PN LEBEDEV PHYS INST,MOSCOW 117924,RUSSIA. MOSCOW PHYS & ENGN INST,MOSCOW 115409,RUSSIA. NOVOSIBDRSK NUCL PHYS INST,NOVOSIBIRSK,RUSSIA. UNIV PITTSBURGH,PITTSBURGH,PA 15213. UNIV ROMA LA SAPIENZA,I-00185 ROME,ITALY. INFN,I-00185 ROME,ITALY. RUTHERFORD APPLETON LAB,DIDCOT OX11 0QX,OXON,ENGLAND. CENS,DPHPE,F-91191 GIF SUR YVETTE,FRANCE. UNIV SALERNO,I-84100 SALERNO,ITALY. INFN,I-84100 SALERNO,ITALY. UNIV STOCKHOLM,S-11346 STOCKHOLM,SWEDEN. UNIV TEL AVIV,IL-9978 RAMAT AVIV,ISRAEL. UNIV TURIN,I-10124 TURIN,ITALY. INFN,I-10100 TURIN,ITALY. UNIV LONDON UNIV COLL,LONDON WC1E 6BT,ENGLAND. WEIZMANN INST SCI,IL-76100 REHOVOT,ISRAEL. RP AKESSON, T (reprint author), CERN,CH-1211 GENEVA 23,SWITZERLAND. RI Smirnov, Sergei/F-1014-2011; Masera, Massimo/J-4313-2012; Ramello, Luciano/F-9357-2013; Tikhomirov, Vladimir/M-6194-2015; Shmeleva, Alevtina/M-6199-2015; Martelli, Filippo/P-4041-2015; OI Smirnov, Sergei/0000-0002-6778-073X; Tikhomirov, Vladimir/0000-0002-9634-0581; Martelli, Filippo/0000-0003-3761-8616; Simone, Saverio/0000-0003-3631-8398; Masera, Massimo/0000-0003-1880-5467 NR 23 TC 4 Z9 4 U1 0 U2 2 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 SN 0170-9739 J9 Z PHYS C PART FIELDS JI Z. Phys. C-Part. Fields PD MAY PY 1993 VL 58 IS 2 BP 239 EP 249 PG 11 WC Physics, Particles & Fields SC Physics GA LA858 UT WOS:A1993LA85800006 ER PT J AU BREAKSTONE, A CAMPANINI, R CRAWLEY, HB DALLAVALLE, GM DENINNO, MM DOROBA, K DRIJARD, D FABBRI, F FIRESTONE, A FISCHER, HG FREHSE, H GEIST, W GIACOMELLI, G GOKIELI, R GORBICS, M HANKE, P HEIDEN, M HERR, W ISENHOWER, LD KLUGE, EE LAMSA, JW LEACOCK, RA LOHSE, T MANKEL, R MEYER, WT MORNACCHI, G NAKADA, T PANTER, M PUTZER, A RAUSCHNABEL, K RENSCH, B RIMONDI, F SCHMELLING, M SIROLI, GP SKEENS, JD SOSNOWSKI, R SZCZEKOWSKI, M ULLALAND, O WEGENER, D YEUNG, R AF BREAKSTONE, A CAMPANINI, R CRAWLEY, HB DALLAVALLE, GM DENINNO, MM DOROBA, K DRIJARD, D FABBRI, F FIRESTONE, A FISCHER, HG FREHSE, H GEIST, W GIACOMELLI, G GOKIELI, R GORBICS, M HANKE, P HEIDEN, M HERR, W ISENHOWER, LD KLUGE, EE LAMSA, JW LEACOCK, RA LOHSE, T MANKEL, R MEYER, WT MORNACCHI, G NAKADA, T PANTER, M PUTZER, A RAUSCHNABEL, K RENSCH, B RIMONDI, F SCHMELLING, M SIROLI, GP SKEENS, JD SOSNOWSKI, R SZCZEKOWSKI, M ULLALAND, O WEGENER, D YEUNG, R TI EVIDENCE FOR F2(1720) PRODUCTION IN THE REACTION POMERON-POMERON -]PI+PI-PI+PI- SO ZEITSCHRIFT FUR PHYSIK C-PARTICLES AND FIELDS LA English DT Article ID CHAMBERS; MODEL AB Data are presented on pomeron-pomeron interactions which produce a central pi+pi-pi+pi- system in proton-proton collisions at square-root s = 62 GeV at the CERN Intersecting Storage Rings. A spin-parity analysis of the pi+pi-pi+pi- system shows evidence for the production of the state f2 (1720) with decay to rho0pi+pi-. Since pomeron-pomeron interactions are expected to favor the production of gluonic bound states, observation of the f2(1720) supports earlier interpretations of it as a glue-ball. In addition, enhancements near threshold give indication of the state f2(1270) decaying to rho0rho0 and the state f0(1400) decaying to rho0pi+pi-. C1 IOWA STATE UNIV SCI & TECHNOL,DEPT PHYS,AMES,IA 50011. IOWA STATE UNIV SCI & TECHNOL,US DOE,AMES LAB,AMES,IA 50011. UNIV BOLOGNA,INST FIS,I-40126 BOLOGNA,ITALY. INFN,BOLOGNA,ITALY. CERN,EUROPEAN ORG NUCL RES,CH-1211 GENEVA 23,SWITZERLAND. UNIV DORTMUND,INST PHYS,W-4600 DORTMUND 50,GERMANY. INST HOCHENERGIEPHYS,HEIDELBERG,GERMANY. UNIV WARSAW,PL-00325 WARSAW,POLAND. INST NUCL RES,PL-00681 WARSAW 91,POLAND. NR 22 TC 10 Z9 10 U1 0 U2 0 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 SN 0170-9739 J9 Z PHYS C PART FIELDS JI Z. Phys. C-Part. Fields PD MAY PY 1993 VL 58 IS 2 BP 251 EP 256 DI 10.1007/BF01560342 PG 6 WC Physics, Particles & Fields SC Physics GA LA858 UT WOS:A1993LA85800007 ER PT J AU SCHEIDEMANN, A KRESIN, VV AF SCHEIDEMANN, A KRESIN, VV TI ELASTIC AND REACTIVE COLLISIONS OF ATOMS AND MOLECULES WITH NEUTRAL ALKALI CLUSTERS SO ZEITSCHRIFT FUR PHYSIK D-ATOMS MOLECULES AND CLUSTERS LA English DT Article; Proceedings Paper CT 6TH INTERNATIONAL SYMP ON SMALL PARTICLES AND INORGANIC CLUSTERS ( ISSPIC 6 ) CY SEP 22-19, 1992 CL UNIV CHICAGO, CHICAGO, IL SP NATL SCI FDN, NATO, ARGONNE NATL LAB, UNIV CHICAGO, CHEM DEPT, DOW CORP, EXTREL, FORD MOTO, IBM, THREE M CO, AMOCO HO UNIV CHICAGO AB We have measured absolute integral cross sections for low-energy collisions of atoms and molecules with neutral sodium clusters over a wide cluster size range (n=2-40). The cross sections are exceptionally large, reaching values of thousands of square angstroms. Consequently, the scattering involves long-range interactions. The van der Waals force, acting either alone (Na(n)+N2) or in concert with the inelastic charge-transfer ''harpooning'' channel (Na(n)+Cl2, Na(n)+O2). can describe the measurements. Using interaction parameters taken from spectroscopic studies of alkali clusters, we find very good agreement with the data. This provides a point of contact between beam scattering experiments and studies of cluster electromagnetic response properties. C1 LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550. RP SCHEIDEMANN, A (reprint author), UNIV WASHINGTON,DEPT CHEM,SEATTLE,WA 98195, USA. RI Kresin, Vitaly/N-8095-2014 OI Kresin, Vitaly/0000-0002-6226-4576 NR 5 TC 2 Z9 2 U1 0 U2 0 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 SN 0178-7683 J9 Z PHYS D ATOM MOL CL JI Z. Phys. D-Atoms Mol. Clusters PD MAY PY 1993 VL 26 IS 1-4 BP 13 EP 16 PG 4 WC Physics, Atomic, Molecular & Chemical SC Physics GA LV430 UT WOS:A1993LV43000004 ER PT J AU PARKS, EK ZHU, L HO, J RILEY, SJ AF PARKS, EK ZHU, L HO, J RILEY, SJ TI CHEMICAL PROBES OF METAL CLUSTER STRUCTURE - FE, CO, NI AND CU SO ZEITSCHRIFT FUR PHYSIK D-ATOMS MOLECULES AND CLUSTERS LA English DT Article; Proceedings Paper CT 6TH INTERNATIONAL SYMP ON SMALL PARTICLES AND INORGANIC CLUSTERS ( ISSPIC 6 ) CY SEP 22-19, 1992 CL UNIV CHICAGO, CHICAGO, IL SP NATL SCI FDN, NATO, ARGONNE NATL LAB, UNIV CHICAGO, CHEM DEPT, DOW CORP, EXTREL, FORD MOTO, IBM, THREE M CO, AMOCO HO UNIV CHICAGO ID NICKEL CLUSTERS; IRON CLUSTERS; IONIZATION-POTENTIALS; ICOSAHEDRAL STRUCTURE; HYDROGEN; AMMONIA; PHOTOIONIZATION; COBALT AB Chemical reactivity is one of the few methods currently available for investigating the geometrical structure of isolated transition metal clusters. In this paper we summarize what is currently known about the structures of clusters of four transition metals, Fe, Co, Ni, and Cu, in the size range from 13 to 180 atoms. Chemical probes used to determine structural information include reactions with H-2 (D2), H2O, NH3 and N2. Measurements at both low coverage and at saturation are discussed. RP PARKS, EK (reprint author), ARGONNE NATL LAB,DIV CHEM,ARGONNE,IL 60439, USA. NR 26 TC 28 Z9 28 U1 3 U2 11 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 SN 0178-7683 J9 Z PHYS D ATOM MOL CL JI Z. Phys. D-Atoms Mol. Clusters PD MAY PY 1993 VL 26 IS 1-4 BP 41 EP 45 PG 5 WC Physics, Atomic, Molecular & Chemical SC Physics GA LV430 UT WOS:A1993LV43000010 ER PT J AU CORBETT, JD SEVOV, SC AF CORBETT, JD SEVOV, SC TI STABLE CLUSTERS IN THE CONDENSED STATE AND SOME POSSIBILITIES FOR GAS-PHASE CLUSTERS SO ZEITSCHRIFT FUR PHYSIK D-ATOMS MOLECULES AND CLUSTERS LA English DT Article; Proceedings Paper CT 6TH INTERNATIONAL SYMP ON SMALL PARTICLES AND INORGANIC CLUSTERS ( ISSPIC 6 ) CY SEP 22-19, 1992 CL UNIV CHICAGO, CHICAGO, IL SP NATL SCI FDN, NATO, ARGONNE NATL LAB, UNIV CHICAGO, CHEM DEPT, DOW CORP, EXTREL, FORD MOTO, IBM, THREE M CO, AMOCO HO UNIV CHICAGO ID POST-TRANSITION ELEMENTS; INTERMETALLIC PHASES; COMPOUND CLUSTERS; MOLECULES; CHEMISTRY; STABILITY; SYSTEMS; METALS AB The classical naked cluster ions of the post-transition elements that are stable in solid compounds and their lower charged analogues observed in mixed metal beams reflect the reduced number of good bonding orbitals. New cluster ions of indium that are hypoelectronic (fewer than 2n+2 skeletal bonding electrons) because of distortions or the bonding of heterometal atoms within the clusters are described. A large family of new, orbital-rich clusters of the group III and IV transition metals sheathed by halide are all centered by a wide variety of heteroatoms. Factors in their stability, possible analogous naked cluster targets, and some calculations are considered. C1 IOWA STATE UNIV SCI & TECHNOL,DEPT CHEM,AMES,IA 50011. RP CORBETT, JD (reprint author), IOWA STATE UNIV SCI & TECHNOL,DOE,AMES LAB,AMES,IA 50011, USA. NR 31 TC 4 Z9 4 U1 0 U2 0 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 SN 0178-7683 J9 Z PHYS D ATOM MOL CL JI Z. Phys. D-Atoms Mol. Clusters PD MAY PY 1993 VL 26 IS 1-4 BP 64 EP 68 PG 5 WC Physics, Atomic, Molecular & Chemical SC Physics GA LV430 UT WOS:A1993LV43000015 ER PT J AU JELLINEK, J GUVENC, ZB AF JELLINEK, J GUVENC, ZB TI CLUSTER-MOLECULE SYSTEMS - ANALYSIS AND TUNING OF THE INTERACTION POTENTIAL SO ZEITSCHRIFT FUR PHYSIK D-ATOMS MOLECULES AND CLUSTERS LA English DT Article; Proceedings Paper CT 6TH INTERNATIONAL SYMP ON SMALL PARTICLES AND INORGANIC CLUSTERS ( ISSPIC 6 ) CY SEP 22-19, 1992 CL UNIV CHICAGO, CHICAGO, IL SP NATL SCI FDN, NATO, ARGONNE NATL LAB, UNIV CHICAGO, CHEM DEPT, DOW CORP, EXTREL, FORD MOTO, IBM, THREE M CO, AMOCO HO UNIV CHICAGO ID METAL CLUSTER; DISSOCIATION DYNAMICS; STRUCTURAL ISOMERS; PALLADIUM CLUSTERS; NI CLUSTERS; CHEMISORPTION; HYDROGEN; NICKEL; H-2; D2 AB The interaction (modelled by a LEPS potential) of a D2 molecule with an icosahedral Ni13 cluster is mapped and analyzed in the form of equipotential contour plots. The topological features of the map correlate with the energetic and dynamical characteristics of the dissociative adsorption of the molecule on the cluster, which were extracted from quasiclassical trajectory simulations. A modification of the LEPS potential used originally is introduced. It brings the calculated reactivity of the cluster into agreement with the experimental data. RP JELLINEK, J (reprint author), ARGONNE NATL LAB,DIV CHEM,ARGONNE,IL 60439, USA. NR 36 TC 27 Z9 28 U1 0 U2 0 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 SN 0178-7683 J9 Z PHYS D ATOM MOL CL JI Z. Phys. D-Atoms Mol. Clusters PD MAY PY 1993 VL 26 IS 1-4 BP 110 EP 114 PG 5 WC Physics, Atomic, Molecular & Chemical SC Physics GA LV430 UT WOS:A1993LV43000025 ER PT J AU DESAI, S FEIGERLE, CS MILLER, JC AF DESAI, S FEIGERLE, CS MILLER, JC TI MULTIPHOTON IONIZATION AND PHOTODISSOCIATION OF (NO)MAR(N) CLUSTERS SO ZEITSCHRIFT FUR PHYSIK D-ATOMS MOLECULES AND CLUSTERS LA English DT Article; Proceedings Paper CT 6TH INTERNATIONAL SYMP ON SMALL PARTICLES AND INORGANIC CLUSTERS ( ISSPIC 6 ) CY SEP 22-19, 1992 CL UNIV CHICAGO, CHICAGO, IL SP NATL SCI FDN, NATO, ARGONNE NATL LAB, UNIV CHICAGO, CHEM DEPT, DOW CORP, EXTREL, FORD MOTO, IBM, THREE M CO, AMOCO HO UNIV CHICAGO ID VANDERWAALS MOLECULES; NO DIMER; SPECTROSCOPY; DYNAMICS; RANGE; IONS AB Picosecond multiphoton ionization of (NO)(m)Ar(n) clusters produced in a supersonic expansion of NO/Ar gas mixtures has been studied using time-of-flight mass spectrometry. Two-photon ionization with 266 nm photons show that dilute gas mixtures (1% NO/Ar) yield clusters limited to m less-than-or-equal-to 7, but with as many as 37 argon atoms. Magic numbers are observed for NO+Ar12, NO+Ar18, (NO)2+Ar17, NO+Ar22, and (NO)2+Ar21 and are understood in terms of solvation of the NO+ and (NO)2+ by argon in icosahedral arrangements. Four-photon ionization with 532 nm light produces dissociation of the clusters to yield only NO+Ar(n) with n up to 54. This distribution exhibits an additional magic number at n = 54, consistent with the completion of a second solvation sphere about the NO+. The known wavelength dependence for photodissociation of (NO)2+ and (NO)3+ and comparison of MPI spectra obtained with 266, 355, and 532 nm light indicate that the dissociation is occurring in the cluster ions. C1 UNIV TENNESSEE,DEPT CHEM,KNOXVILLE,TN 37996. RP DESAI, S (reprint author), OAK RIDGE NATL LAB,CHEM PHYS SECT,OAK RIDGE,TN 37831, USA. NR 19 TC 12 Z9 12 U1 0 U2 1 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 SN 0178-7683 J9 Z PHYS D ATOM MOL CL JI Z. Phys. D-Atoms Mol. Clusters PD MAY PY 1993 VL 26 IS 1-4 BP 220 EP 222 PG 3 WC Physics, Atomic, Molecular & Chemical SC Physics GA LV430 UT WOS:A1993LV43000057 ER PT J AU GUVENC, ZB JELLINEK, J AF GUVENC, ZB JELLINEK, J TI SURFACE MELTING IN NI(55) SO ZEITSCHRIFT FUR PHYSIK D-ATOMS MOLECULES AND CLUSTERS LA English DT Article; Proceedings Paper CT 6TH INTERNATIONAL SYMP ON SMALL PARTICLES AND INORGANIC CLUSTERS ( ISSPIC 6 ) CY SEP 22-19, 1992 CL UNIV CHICAGO, CHICAGO, IL SP NATL SCI FDN, NATO, ARGONNE NATL LAB, UNIV CHICAGO, CHEM DEPT, DOW CORP, EXTREL, FORD MOTO, IBM, THREE M CO, AMOCO HO UNIV CHICAGO ID TRANSITION-METAL CLUSTERS; LENNARD-JONES CLUSTERS; ISOMERIZATION; DYNAMICS; MICROCLUSTERS AB The phenomenon of surface melting in a Ni-55 cluster is predicted from results of molecular dynamics simulations. RP GUVENC, ZB (reprint author), ARGONNE NATL LAB,DIV CHEM,ARGONNE,IL 60439, USA. NR 28 TC 57 Z9 57 U1 0 U2 2 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 SN 0178-7683 J9 Z PHYS D ATOM MOL CL JI Z. Phys. D-Atoms Mol. Clusters PD MAY PY 1993 VL 26 IS 1-4 BP 304 EP 306 PG 3 WC Physics, Atomic, Molecular & Chemical SC Physics GA LV430 UT WOS:A1993LV43000083 ER PT J AU ZHU, L HO, J PARKS, EK RILEY, SJ AF ZHU, L HO, J PARKS, EK RILEY, SJ TI PHYSISORPTION OF DEUTERIUM ON DEUTERATED NICKEL CLUSTERS SO ZEITSCHRIFT FUR PHYSIK D-ATOMS MOLECULES AND CLUSTERS LA English DT Article; Proceedings Paper CT 6TH INTERNATIONAL SYMP ON SMALL PARTICLES AND INORGANIC CLUSTERS ( ISSPIC 6 ) CY SEP 22-19, 1992 CL UNIV CHICAGO, CHICAGO, IL SP NATL SCI FDN, NATO, ARGONNE NATL LAB, UNIV CHICAGO, CHEM DEPT, DOW CORP, EXTREL, FORD MOTO, IBM, THREE M CO, AMOCO HO UNIV CHICAGO ID IRON CLUSTERS; HYDROGEN; H-2; METALS AB The physisorption of deuterium molecules on small nickel clusters having chemisorbed deuterium atoms is identified. The principal evidence for physisorption is the appearance at reaction temperatures below 200 K of product species having more deuterium bound to them than the chemisorption maximum, and a lowering of cluster ionization potentials (IPs) for these species. It is argued that the IP lowering is a consequence of molecular physisorption, and that identification of the number of physisorption sites on cluster surfaces can be used to infer structural information. RP ZHU, L (reprint author), ARGONNE NATL LAB,DIV CHEM,ARGONNE,IL 60439, USA. NR 14 TC 9 Z9 9 U1 0 U2 0 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 SN 0178-7683 J9 Z PHYS D ATOM MOL CL JI Z. Phys. D-Atoms Mol. Clusters PD MAY PY 1993 VL 26 IS 1-4 BP 313 EP 315 PG 3 WC Physics, Atomic, Molecular & Chemical SC Physics GA LV430 UT WOS:A1993LV43000086 ER PT J AU GARZON, IL JELLINEK, J AF GARZON, IL JELLINEK, J TI PECULIARITIES OF STRUCTURES AND MELTING-LIKE TRANSITION IN GOLD CLUSTERS SO ZEITSCHRIFT FUR PHYSIK D-ATOMS MOLECULES AND CLUSTERS LA English DT Article; Proceedings Paper CT 6TH INTERNATIONAL SYMP ON SMALL PARTICLES AND INORGANIC CLUSTERS ( ISSPIC 6 ) CY SEP 22-19, 1992 CL UNIV CHICAGO, CHICAGO, IL SP NATL SCI FDN, NATO, ARGONNE NATL LAB, UNIV CHICAGO, CHEM DEPT, DOW CORP, EXTREL, FORD MOTO, IBM, THREE M CO, AMOCO HO UNIV CHICAGO ID METAL CLUSTERS; RANGE AB Structural and dynamical properties of gold clusters are derived from a Gupta-type potential using numerical simulations and are compared to features of nickel clusters derived from the same potential. The major implication of the comparison is that the properties of clusters mimicked by this many-body potential depend, in general, on the values of its parameters. C1 UNIV NACL AUTONOMA MEXICO,INST FIS,ENSENADA 22800,BAJA CALIFORNIA,MEXICO. RP GARZON, IL (reprint author), ARGONNE NATL LAB,DIV CHEM,ARGONNE,IL 60439, USA. NR 15 TC 37 Z9 37 U1 0 U2 0 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 SN 0178-7683 J9 Z PHYS D ATOM MOL CL JI Z. Phys. D-Atoms Mol. Clusters PD MAY PY 1993 VL 26 IS 1-4 BP 316 EP 318 PG 3 WC Physics, Atomic, Molecular & Chemical SC Physics GA LV430 UT WOS:A1993LV43000087 ER PT J AU MENEZES, WJC KNICKELBEIN, MB AF MENEZES, WJC KNICKELBEIN, MB TI THE EVOLUTION OF ELECTRONIC-STRUCTURE IN ALNCOM SO ZEITSCHRIFT FUR PHYSIK D-ATOMS MOLECULES AND CLUSTERS LA English DT Article; Proceedings Paper CT 6TH INTERNATIONAL SYMP ON SMALL PARTICLES AND INORGANIC CLUSTERS ( ISSPIC 6 ) CY SEP 22-19, 1992 CL UNIV CHICAGO, CHICAGO, IL SP NATL SCI FDN, NATO, ARGONNE NATL LAB, UNIV CHICAGO, CHEM DEPT, DOW CORP, EXTREL, FORD MOTO, IBM, THREE M CO, AMOCO HO UNIV CHICAGO ID IONIZATION-POTENTIALS; SHELL STRUCTURE; CLUSTERS; PHOTOIONIZATION AB The ionization potentials of Al(n)Co(m) clusters (n>m) have been bracketed using laser photoionization mass spectrometry. We find the electronic shell structure manifested in the ionization potentials of Al(n) for n greater-than-or-equal-to 7 is observed also for Al(n)Co and AlnCo2, and is consistent with cobalt contributing one electron to the conduction band of the cluster. However, with increasing number of cobalt atoms, this simple picture breaks down; all vestiges of aluminum cluster electronic shell structure are absent for m greater-than-or-equal-to 4. RP MENEZES, WJC (reprint author), ARGONNE NATL LAB,DIV CHEM,ARGONNE,IL 60439, USA. NR 16 TC 22 Z9 24 U1 0 U2 0 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 SN 0178-7683 J9 Z PHYS D ATOM MOL CL JI Z. Phys. D-Atoms Mol. Clusters PD MAY PY 1993 VL 26 IS 1-4 BP 322 EP 324 PG 3 WC Physics, Atomic, Molecular & Chemical SC Physics GA LV430 UT WOS:A1993LV43000089 ER PT J AU HO, J ZHU, L PARKS, EK RILEY, SJ AF HO, J ZHU, L PARKS, EK RILEY, SJ TI REACTIONS OF COBALT CLUSTERS WITH DEUTERIUM SO ZEITSCHRIFT FUR PHYSIK D-ATOMS MOLECULES AND CLUSTERS LA English DT Article; Proceedings Paper CT 6TH INTERNATIONAL SYMP ON SMALL PARTICLES AND INORGANIC CLUSTERS ( ISSPIC 6 ) CY SEP 22-19, 1992 CL UNIV CHICAGO, CHICAGO, IL SP NATL SCI FDN, NATO, ARGONNE NATL LAB, UNIV CHICAGO, CHEM DEPT, DOW CORP, EXTREL, FORD MOTO, IBM, THREE M CO, AMOCO HO UNIV CHICAGO ID TRANSITION-METAL CLUSTERS; HYDROGEN CHEMISORPTION; IRON CLUSTERS; NICKEL CLUSTERS; KINETICS; H-2; REACTIVITY; SURFACES; IONS AB The kinetics of chemical reactions of cobalt clusters Co(n) with deuterium are described. Absolute rate constants have been measured in the size range n = 7-68 at 293 K. The rate constants are found to be a strong function of cluster size, varying by a factor of 400. This size dependence is most prominent for n = 7 to 25: Co15 is the most reactive cluster, and Co7-9 and Co19-20 are particularly unreactive. Abrupt changes in the rate constants from one cluster size to the next are observed. For the clusters above n = 25, the rate constants show several less prominent maxima and minima superimposed on a slow, nearly monotonic increase with cluster size. RP HO, J (reprint author), ARGONNE NATL LAB,DIV CHEM,ARGONNE,IL 60439, USA. NR 23 TC 14 Z9 14 U1 0 U2 2 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 SN 0178-7683 J9 Z PHYS D ATOM MOL CL JI Z. Phys. D-Atoms Mol. Clusters PD MAY PY 1993 VL 26 IS 1-4 BP 331 EP 333 PG 3 WC Physics, Atomic, Molecular & Chemical SC Physics GA LV430 UT WOS:A1993LV43000092 ER PT J AU DESAI, S FEIGERLE, CS MILLER, JC AF DESAI, S FEIGERLE, CS MILLER, JC TI MAGIC CLUSTER ION DISTRIBUTIONS - (NO)3+ (N2O)N AND (NO)3+ (CO2)N SO ZEITSCHRIFT FUR PHYSIK D-ATOMS MOLECULES AND CLUSTERS LA English DT Article; Proceedings Paper CT 6TH INTERNATIONAL SYMP ON SMALL PARTICLES AND INORGANIC CLUSTERS ( ISSCIP 6 ) CY SEP 16-22, 1992 CL CHICAGO, IL SP NATL SCI FDN, NATO, ARGONNE NATL LAB, UNIV CHICAGO, CHEM DEPT, DOW, FORD MOTOR, IBM, THREE M CO, AMOCO, EXXON ID MULTIPHOTON IONIZATION; METASTABLE POLYMERS; PHOTO-IONIZATION; NITROGEN-OXIDES; DIMERS; MNDO/AM1; BEAM AB Supersonic jet expansions of mixtures of nitric oxide with either nitrous oxide or carbon dioxide have been investigated over a wide range of relative concentrations. Mixed molecular cluster ions of the form (NO)m+(N2O)n and (NO)m+(CO2)n. are detected following non-resonant two-photon ionization. Over a wide range of intermediate concentrations, the cluster ion distributions (NO)3+(N2O)n and (NO)3+(CO2)n with n less-than-or-equal-to 30 are significantly more intense than clusters containing other numbers of nitric oxide molecules. The extra abundance of these species is attributed to their especially stable structures and several possible forms are discussed. An intriguing possibility involves a stable cyclic nitric oxide trimer (or ion) when combined with nitrous oxide or carbon dioxide clusters. C1 UNIV TENNESSEE,DEPT CHEM,KNOXVILLE,TN 37996. RP DESAI, S (reprint author), OAK RIDGE NATL LAB,CHEM PHYS SECT,OAK RIDGE,TN 37831, USA. NR 20 TC 6 Z9 6 U1 0 U2 0 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 SN 0178-7683 J9 Z PHYS D ATOM MOL CL JI Z. Phys. D-Atoms Mol. Clusters PD MAY PY 1993 VL 26 SU S BP S183 EP S185 PG 3 WC Physics, Atomic, Molecular & Chemical SC Physics GA ME190 UT WOS:A1993ME19000061 ER PT J AU LIU, SZ VU, R YEE, A BUSSELL, A CHANG, RPH MICHEL, R RICHARD, S BRAUCHLE, G WEIS, P BECK, R KAPPES, MM AF LIU, SZ VU, R YEE, A BUSSELL, A CHANG, RPH MICHEL, R RICHARD, S BRAUCHLE, G WEIS, P BECK, R KAPPES, MM TI CHROMATOGRAPHIC ENRICHMENT AND SEPARATION OF THE HIGHER FULLERENES SO ZEITSCHRIFT FUR PHYSIK D-ATOMS MOLECULES AND CLUSTERS LA English DT Article; Proceedings Paper CT 6TH INTERNATIONAL SYMP ON SMALL PARTICLES AND INORGANIC CLUSTERS ( ISSCIP 6 ) CY SEP 16-22, 1992 CL CHICAGO, IL SP NATL SCI FDN, NATO, ARGONNE NATL LAB, UNIV CHICAGO, CHEM DEPT, DOW, FORD MOTOR, IBM, THREE M CO, AMOCO, EXXON ID POLYCYCLIC AROMATIC-HYDROCARBONS; CARBON; C-84; RETENTION; ISOMERS; STATE; C-76; C-60; C76; C84 AB Column chromatographic and HPLC procedures were used to optimize the separation and purification of several higher fullerenes, C(n) (n>70). C1 NORTHWESTERN UNIV,SCH MED,CHICAGO,IL 60611. NORTHWESTERN UNIV,DEPT MAT SCI,EVANSTON,IL 60201. UNIV KARLSRUHE,LEHRSTUHL PHYS CHEM 2,W-7500 KARLSRUHE,GERMANY. RP LIU, SZ (reprint author), ARGONNE NATL LAB,DIV CHEM,ARGONNE,IL 60439, USA. RI Chang, R.P.H/B-7505-2009 NR 17 TC 1 Z9 1 U1 1 U2 1 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 SN 0178-7683 J9 Z PHYS D ATOM MOL CL JI Z. Phys. D-Atoms Mol. Clusters PD MAY PY 1993 VL 26 SU S BP S267 EP S269 PG 3 WC Physics, Atomic, Molecular & Chemical SC Physics GA ME190 UT WOS:A1993ME19000089 ER PT J AU WANG, XQ WANG, CZ ZHANG, BL HO, KM AF WANG, XQ WANG, CZ ZHANG, BL HO, KM TI STRUCTURAL AND ELECTRONIC-PROPERTIES OF LARGE FULLERENES SO ZEITSCHRIFT FUR PHYSIK D-ATOMS MOLECULES AND CLUSTERS LA English DT Article; Proceedings Paper CT 6TH INTERNATIONAL SYMP ON SMALL PARTICLES AND INORGANIC CLUSTERS ( ISSCIP 6 ) CY SEP 16-22, 1992 CL CHICAGO, IL SP NATL SCI FDN, NATO, ARGONNE NATL LAB, UNIV CHICAGO, CHEM DEPT, DOW, FORD MOTOR, IBM, THREE M CO, AMOCO, EXXON ID C-84; ISOMERS; C-76; C76; C84 AB We present the results of a first-principles calculation for the geometrical and electronic structure of C78 and C84 fullerene isomers. Our study confirms that for C84 two isomers with D2 and D2d symmetries are the most energetically favorable, and for C78 a C2, isomer is the ground-state configuration. Results from the present calculation are compared with recent experimental observations. C1 IOWA STATE UNIV SCI & TECHNOL,USDOE,AMES LAB,AMES,IA 50011. IOWA STATE UNIV SCI & TECHNOL,DEPT PHYS & ASTRON,AMES,IA 50011. RP WANG, XQ (reprint author), CLARK ATLANTA UNIV,CTR THEORET STUDIES PHYS SYST,ATLANTA,GA 30314, USA. NR 17 TC 1 Z9 1 U1 0 U2 0 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 SN 0178-7683 J9 Z PHYS D ATOM MOL CL JI Z. Phys. D-Atoms Mol. Clusters PD MAY PY 1993 VL 26 SU S BP S264 EP S266 PG 3 WC Physics, Atomic, Molecular & Chemical SC Physics GA ME190 UT WOS:A1993ME19000088 ER PT J AU ZHANG, BL WANG, CZ HO, KM CHAN, CT AF ZHANG, BL WANG, CZ HO, KM CHAN, CT TI MELTING OF CARBON CAGES SO ZEITSCHRIFT FUR PHYSIK D-ATOMS MOLECULES AND CLUSTERS LA English DT Article; Proceedings Paper CT 6TH INTERNATIONAL SYMP ON SMALL PARTICLES AND INORGANIC CLUSTERS ( ISSCIP 6 ) CY SEP 16-22, 1992 CL CHICAGO, IL SP NATL SCI FDN, NATO, ARGONNE NATL LAB, UNIV CHICAGO, CHEM DEPT, DOW, FORD MOTOR, IBM, THREE M CO, AMOCO, EXXON AB We simulate the melting of carbon fullerenes by molecular dynamics using an accurate tight-binding model. The melting temperatures are obtained for fullerenes ranging from C20 to C81. For small cages (n less-than-or-equal-to 58), We found that the melting temperature increases almost linearly with the cluster size. However, the melting temperature of the larger fullerenes (n = 60 and n greater-than-or-equal-to 70) is fairly constant and does not change much with cluster size. C1 IOWA STATE UNIV SCI & TECHNOL,DEPT PHYS & ASTRON,AMES,IA 50011. RP ZHANG, BL (reprint author), US DOE,AMES LAB,AMES,IA 50011, USA. NR 8 TC 3 Z9 3 U1 0 U2 0 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 SN 0178-7683 J9 Z PHYS D ATOM MOL CL JI Z. Phys. D-Atoms Mol. Clusters PD MAY PY 1993 VL 26 SU S BP S285 EP S287 PG 3 WC Physics, Atomic, Molecular & Chemical SC Physics GA ME190 UT WOS:A1993ME19000095 ER PT J AU Munne, S Tang, YX Weier, HUG Stein, J Finkelstein, M Grifo, J Cohen, J AF Munne, Santiago Tang, Ya Xu Weier, Heinz-Ulrich G. Stein, Jonathan Finkelstein, Michelle Grifo, Jamie Cohen, Jacques TI Sex distribution in arrested precompacted human embryos SO ZYGOTE LA English DT Article DE In situ hybridisation; Mosaic; Polymerase chain reactions; X chromosome; Y chromosome AB Evidence of sexual dimorphism before fetal gonadal differentiation in mammals has been accumulating, suggesting that male embryos develop faster than female ones. The current investigation was performed to evaluate whether the development rate of precompacted human embryos is controlled by sex chromosomes. Sex was determined by polymerase chain reaction and fluorescence in situ hybridisation in 172 arrested embryos derived from in vitro fertilisation. The sex ratio (1.02:0.98) did not differ significantly from 1:1. Although more males appeared to have greater fragmentation, the difference between the sex ratios of highly fragmented and normal embryos (1.08:0.92) was not significant. Arrested female embryos had a tendency to exhibit more than five nuclei and less than 10% fragmentation, but the trend was not statistically significant. The current results suggest that the first developmental block in human embryos occurs prior to and shortly after genomic activation and is not determined by the presence of the Y chromosome. C1 Cornell Univ Ctr, New York Hosp, Ctr Reprod Med & Infertil, New York, NY USA. Univ Calif San Francisco, Div Mol Cytometry, San Francisco, CA 94143 USA. [Weier, Heinz-Ulrich G.] Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Dept Life Sci, Berkeley, CA 94720 USA. RP Munne, S (reprint author), Cornell Univ, Coll Med, Gamete & Embryo Res Lab, POB 30,1300 York Ave, New York, NY 10021 USA. OI Munne, Santiago/0000-0002-1088-5565; Grifo, James/0000-0003-0439-2374 FU Amoco Technology Corporation; Redel Foundation FX This work was supported in part by a grant from Amoco Technology Corporation to Dr Weier. The Redel Foundation in part supports the Gamete and Embryology Research Laboratory. Embryologists Mina Alikani, Alexis Adler, Adrienne Reing, Toni Ferrara and Elena Kissin are acknowledged for technical assistance. We are grateful to Drs Bedford, Rosenwaks and Ledger for their support of this work. Francine Cabral is acknowledged for assistance during preparation of this manuscript. NR 43 TC 6 Z9 6 U1 0 U2 0 PU CAMBRIDGE UNIV PRESS PI NEW YORK PA 32 AVENUE OF THE AMERICAS, NEW YORK, NY 10013-2473 USA SN 0967-1994 EI 1469-8730 J9 ZYGOTE JI Zygote PD MAY PY 1993 VL 1 IS 2 BP 155 EP 162 PG 9 WC Cell Biology; Developmental Biology; Reproductive Biology SC Cell Biology; Developmental Biology; Reproductive Biology GA V35FW UT WOS:000209136900007 PM 8081811 ER PT J AU BARNABAS, MV WERST, DW TRIFUNAC, AD AF BARNABAS, MV WERST, DW TRIFUNAC, AD TI QUADRICYCLANE AND NORBORNADIENE RADICAL CATIONS IN SILICALITE - COMPARISON WITH FREON MATRICES SO CHEMICAL PHYSICS LETTERS LA English DT Article ID ELECTRON-SPIN-RESONANCE; 4-K AB The radical cation of nonbornadiene is produced by gamma radiolysis of nonbornadiene or quadricyclane in silicalite at 77 K. The bicyclo[3.2.0]hepta-2,6-diene radical cation and the bicyclo[2.2.1]hepta-2,5-diene-7-yl radical are observed at higher temperatures. The same radical cation chemistry was recently examined by EPR in freon matrices, and differences with this EPR study in zeolites are discussed. Some zeolite sites must be able to stabilize higher electronic states of radical cations, enabling otherwise photochemical processes to be thermally accessible in zeolites. RP BARNABAS, MV (reprint author), ARGONNE NATL LAB,DIV CHEM,ARGONNE,IL 60439, USA. NR 11 TC 15 Z9 15 U1 0 U2 0 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 APR 30 PY 1993 VL 206 IS 1-4 BP 21 EP 24 DI 10.1016/0009-2614(93)85510-U PG 4 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA KZ446 UT WOS:A1993KZ44600004 ER PT J AU HUANG, YH ZHU, W KOURI, DJ AF HUANG, YH ZHU, W KOURI, DJ TI A GENERAL TIME-TO-ENERGY TRANSFORM OF WAVEPACKETS - TIME-INDEPENDENT WAVEPACKET-SCHRODINGER AND WAVEPACKET-LIPPMANN-SCHWINGER EQUATIONS SO CHEMICAL PHYSICS LETTERS LA English DT Article ID REACTIVE COLLISIONS; ACCURATE AB Recently, new time-independent wavepacket-Schrodinger and wavepacket-Lippmann-Schwinger equations have been derived making use of absorbing potentials. We show that these equations, which are characterized by the occurrence of an initial L2-wavepacket source of scattered waves, can be gotten without introducing the absorbing potential. We also show that a powerful method of solving the equations can be based on a Chebychev representation of the causal full Green function, combined with the distributed approximating function representation of the system Hamiltonian, and we present two example applications illustrating the approach. 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. RP HUANG, YH (reprint author), UNIV HOUSTON,DEPT CHEM,HOUSTON,TX 77204, USA. NR 21 TC 112 Z9 113 U1 0 U2 5 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 APR 30 PY 1993 VL 206 IS 1-4 BP 96 EP 101 DI 10.1016/0009-2614(93)85523-Q PG 6 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA KZ446 UT WOS:A1993KZ44600017 ER PT J AU CONNOR, JNL MCCABE, P SOKOLOVSKI, D SCHATZ, GC AF CONNOR, JNL MCCABE, P SOKOLOVSKI, D SCHATZ, GC TI NEARSIDE FARSIDE ANALYSIS OF ANGULAR SCATTERING IN ELASTIC, INELASTIC AND REACTIVE MOLECULAR-COLLISIONS SO CHEMICAL PHYSICS LETTERS LA English DT Article ID DISTRIBUTIONS AB The first application to molecular collisions is reported of an approximate version of Fuller's nearside-farside theory of angular scattering. Application is made to resonance and non-resonance angular scattering in the Cl+HCl(v=1, j=5)-->ClH (v'=0, j'=15)+Cl reaction. The nearside-farside theory provides insight into structured angular distributions, is simple to incorporate into existing computer programs, and should find wide application in molecular collision theory calculations. C1 ARGONNE NATL LAB, THEORET CHEM GRP, ARGONNE, IL 60439 USA. RP CONNOR, JNL (reprint author), UNIV MANCHESTER, DEPT CHEM, MANCHESTER M13 9PL, LANCS, ENGLAND. RI McCabe, Patrick/M-3718-2013 OI McCabe, Patrick/0000-0003-2538-4920 NR 10 TC 48 Z9 48 U1 0 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 APR 30 PY 1993 VL 206 IS 1-4 BP 119 EP 122 DI 10.1016/0009-2614(93)85527-U PG 4 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA KZ446 UT WOS:A1993KZ44600021 ER PT J AU THOMPSON, WH MILLER, WH AF THOMPSON, WH MILLER, WH TI STATE-SPECIFIC REACTION PROBABILITIES FROM A DVR-ABC GREEN-FUNCTION SO CHEMICAL PHYSICS LETTERS LA English DT Article ID POTENTIAL-ENERGY SURFACE; SCATTERING; APPROXIMATION; PROPAGATION AB Seideman and Miller have recently introduced a direct, efficient method for calculating cumulative reaction probabilities by using a discrete variable representation to represent the Green function and absorbing boundary conditions to enforce the outgoing wave boundary conditions. It is shown that this method for representing the Green function can also be used to calculate state-specific reaction probabilities. Application to the collinear reaction H + H-2-->H-2 + H demonstrates that the method is an efficient way to calculate state-to-state and partially state-resolved reaction probabilities. In addition, distorted waves are useful in reducing the size of the DVR basis. C1 LAWRENCE BERKELEY LAB,DIV CHEM SCI,BERKELEY,CA 94720. RP THOMPSON, WH (reprint author), UNIV CALIF BERKELEY,DEPT CHEM,BERKELEY,CA 94720, USA. OI Thompson, Ward/0000-0002-3636-6448 NR 27 TC 45 Z9 45 U1 0 U2 5 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 APR 30 PY 1993 VL 206 IS 1-4 BP 123 EP 129 DI 10.1016/0009-2614(93)85528-V PG 7 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA KZ446 UT WOS:A1993KZ44600022 ER PT J AU ZHENG, Y HUSSAIN, Z SHIRLEY, DA AF ZHENG, Y HUSSAIN, Z SHIRLEY, DA TI THE INFLUENCE OF CALCULATED PHASE-SHIFTS ON THE PRECISION AND ACCURACY OF ARPEFS-DERIVED STRUCTURAL PARAMETERS SO CHEMICAL PHYSICS LETTERS LA English DT Article ID ABSORPTION FINE-STRUCTURE; X-RAY-ABSORPTION; STRUCTURE SPECTROSCOPY; CHALCOGEN OVERLAYERS; ADSORBATE-GEOMETRY; ADSORPTION; COVERAGE; NI(001) AB The influence of theoretical atomic scattering phase shifts calculated by different methods in the analysis of angle-resolved photoemission extended fine structure (ARPEFS) data for structural determination of the c(2x2)S/Ni(001) surface was examined, with the goal of assessing both the precision and accuracy of derived structural parameters. It was found that the values of the S-Ni bond length obtained from the ARPEFS data analysis with different calculated atomic scattering phase shifts all fall within a total range of 0.02 angstrom (+/- 0.01 angstrom). This result is also in excellent agreement with the currently accepted values obtained from low-energy electron diffraction (LEED) and surface extended X-ray absorption fine structure (SEXAFS), i.e. 2.19-2.20 angstrom. We conclude that this ARPEFS-derived structural parameter is relatively insensitive to the choice of theoretical atomic scattering phase shifts, and is both precise and accurate. C1 PENN STATE UNIV,DEPT CHEM,UNIV PK,PA 16802. PENN STATE UNIV,DEPT PHYS,UNIV PK,PA 16802. RP ZHENG, Y (reprint author), LAWRENCE BERKELEY LAB,DIV CHEM SCI,BERKELEY,CA 94720, USA. NR 24 TC 1 Z9 1 U1 0 U2 0 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 APR 30 PY 1993 VL 206 IS 1-4 BP 161 EP 165 DI 10.1016/0009-2614(93)85534-U PG 5 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA KZ446 UT WOS:A1993KZ44600028 ER PT J AU MARINO, MM ERMLER, WC AF MARINO, MM ERMLER, WC TI ABINITIO REP-BASED RELATIVISTIC CORE VALENCE POLARIZATION OPERATOR SO CHEMICAL PHYSICS LETTERS LA English DT Article ID POTENTIALS; ATOMS; ALKALI AB The adiabatic core polarization procedure of Christiansen is expanded to derive an REP-based relativistic core/valence correlation potential (RCVPP) operator. The operator is derived from data corresponding to individual orbital energies, rather than total energies, within a j-j coupling scheme and is grounded in the relativistic effective potential approximation. The calculation from individual orbital energies in j-j coupling has the advantage of treating systems as eigenfunctions of the total angular momentum squared operator, thereby allowing each ljm component of the RCVPP operator to be calculated and its contribution to the total operator to be determined individually. C1 STEVENS INST TECHNOL, DEPT CHEM & CHEM ENGN, HOBOKEN, NJ 07030 USA. RP MARINO, MM (reprint author), PACIFIC NW LAB, MOLEC SCI RES CTR, RICHLAND, WA 99352 USA. RI Ermler, Walter/B-6876-2011 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 0009-2614 J9 CHEM PHYS LETT JI Chem. Phys. Lett. PD APR 30 PY 1993 VL 206 IS 1-4 BP 271 EP 277 DI 10.1016/0009-2614(93)85551-X PG 7 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA KZ446 UT WOS:A1993KZ44600045 ER PT J AU ZHU, J GUIOCHON, G AF ZHU, J GUIOCHON, G TI THE SHOCK LAYER THICKNESS, A NEW APPROACH TO THE STUDY OF COLUMN PERFORMANCE IN NONLINEAR CHROMATOGRAPHY .1. OPTIMUM LINEAR VELOCITY IN FRONTAL ANALYSIS SO JOURNAL OF CHROMATOGRAPHY LA English DT Article ID DISPLACEMENT CHROMATOGRAPHY; LIQUID-CHROMATOGRAPHY; NONLINEAR CHROMATOGRAPHY; OPERATING PARAMETERS; LANGMUIR ISOTHERM; EXCHANGE SYSTEMS; IDEAL MODEL; BAND; OVERLOAD; PROFILES AB In non-linear chromatography, it is common to observe very steep profiles. This happens for overloaded elution bands, for frontal analysis breakthrough curves and for the band profiles of the isotachic train in displacement chromatography. These regions where the concentration vary very rapidly are called shock layers. The relationship between the thickness of the shock layer in frontal analysis and the coefficients of the conventional terms of the plate height equation were studied experimentally. The shock layer theory of Rhee and co-workers permits the simple determination of the optimum linear velocity for minimum shock layer thickness in the case when the adsorption behavior of the feed components is described by the Langmuir model. The optimum linear velocity in frontal analysis is not only a function of the coefficients of the axial dispersion and the mass transfer resistance terms, and the retention factor (k0'), as in linear chromatography, but also a function of the plateau concentrations and the second Langmuir parameter of the isotherm, b. Depending on the retention factor, the optimum velocity in frontal analysis may be larger, but is most often much smaller than in linear chromatography. Experimental results are in excellent agreement with the prediction of the theory. If they could be extended to displacement chromatography, these findings would explain some apparent contradictions found in the literature regarding the influence of the mobile phase flow velocity on the degree of separation between bands achieved in displacement chromatography, and clarify certain controversies. C1 UNIV TENNESSEE,DEPT CHEM,KNOXVILLE,TN 37996. OAK RIDGE NATL LAB,DIV ANALYT CHEM,OAK RIDGE,TN 37831. NR 37 TC 9 Z9 9 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0021-9673 J9 J CHROMATOGR PD APR 30 PY 1993 VL 636 IS 2 BP 189 EP 202 DI 10.1016/0021-9673(93)80232-W PG 14 WC Chemistry, Analytical SC Chemistry GA LA710 UT WOS:A1993LA71000001 ER PT J AU CHAWLA, KK FERBER, MK XU, ZR VENKATESH, R AF CHAWLA, KK FERBER, MK XU, ZR VENKATESH, R TI INTERFACE ENGINEERING IN ALUMINA GLASS COMPOSITES SO MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING LA English DT Article; Proceedings Paper CT WORKSHOP ON INTERFACES IN COMPOSITE MATERIALS CY JUN 17-19, 1992 CL WOODS HOLE, MA ID WHISKER-REINFORCED CERAMICS; MATRIX COMPOSITES; SILICON-CARBIDE; INTERPHASE; BEHAVIOR AB Oxide-fiber/oxide-matrix composites, such as alumina-fiber/glass-matrix composites, represent an important class of ceramic matrix composites because of their inherent stability in air at high temperatures. Alumina and glass, however, form a very strong chemical bond, which is undesirable from a toughness point of view. We present an interface engineering approach, which involves the incorporation of an interphase between the matrix and the fiber in order to produce energy dissipating processes such as interface debonding, crack deflection, and fiber pull-out in this system. We first examined the efficacy of tin dioxide as a barrier coating between alumina and glass bars. We confirmed by microprobe analysis that alumina and tin dioxide were mutually insoluble but there was some solubility between silica and tin dioxide. This was followed by coating continuous PRD-166 (alumina + 15 wt.% zirconia) fiber with SnO2 and analyzing the microstructure and mechanical behavior of coated fiber composites. We observed that although the SnO2 coating provided the intended diffusion barrier and the thermal stress distribution was of the desirable kind, a neat and clean fiber pull-out was absent because of the roughness of the PRD-166-SnO2 interface. Some fiber/matrix debonding, crack deflection, and crack bridging occurred. The roughness-induced radial clamping stress was too large to allow fiber pull-out. To reduce this radial clamping effect, we then used a relatively smooth fiber, Saphikon, a single-crystal alumina fiber. As expected, the SnO2-coated-Saphikon-fiber/glass composite showed a much larger fiber pull-out length than the coated-PRD-166-fiber/glass composite. Thus, a judicious interplay of thermal stress distribution and interfacial roughness in a ceramic matrix composite with an interphase can result in the deformation micromechanisms required for enhanced toughness. C1 OAK RIDGE NATL LAB,HIGH TEMP MAT LAB,OAK RIDGE,TN 37830. RP CHAWLA, KK (reprint author), NEW MEXICO INST MIN & TECHNOL,DEPT MAT & MET ENGN,SOCORRO,NM 87801, USA. NR 31 TC 26 Z9 26 U1 2 U2 4 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE 1 PA PO BOX 564, 1001 LAUSANNE 1, SWITZERLAND SN 0921-5093 J9 MAT SCI ENG A-STRUCT JI Mater. Sci. Eng. A-Struct. Mater. Prop. Microstruct. Process. PD APR 30 PY 1993 VL 162 IS 1-2 BP 35 EP 44 DI 10.1016/0921-5093(90)90028-2 PG 10 WC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Science & Technology - Other Topics; Materials Science; Metallurgy & Metallurgical Engineering GA LF638 UT WOS:A1993LF63800005 ER PT J AU PEYRARD, M PIETTE, B ZAKRZEWSKI, WJ AF PEYRARD, M PIETTE, B ZAKRZEWSKI, WJ TI SOLITON-LIKE BEHAVIOR IN A MODIFIED SINE-GORDON MODEL SO PHYSICA D LA English DT Article ID BARYONS AB We consider a sine-Gordon model in 1 + 1 dimensions modified by the addition of a further kinetic term similar to the Skyrme term in higher dimensions and an extra potential term. The model has interesting properties. In particular, in addition to the familiar sine-Gordon soliton it possesses a double-kink solution which has an internal oscillatory mode. The sine-Gordon kink has a definite velocity and this velocity is a critical velocity for the double-kink structures. For some range of the parameters the model has two different solutions, with the same boundary conditions, which propagate at the velocity of the sine-Gordon kink. When the exact solutions are perturbed or acted upon by an external force they radiate short wavelength oscillations and keep a velocity which remains below the critical value. The same radiation can also stabilize the speed of pi-kink solutions for which the boundary conditions correspond to two different levels of the potential energy. C1 LOS ALAMOS NATL LAB,CTR NONLINEAR STUDIES,LOS ALAMOS,NM 87545. UNIV DURHAM,DEPT MATH SCI,DURHAM DH1 3LE,ENGLAND. RP PEYRARD, M (reprint author), ECOLE NORMALE SUPER LYON,PHYS LAB,CNRS,URA 1325,46 ALLEE ITALIE,F-69364 LYON 07,FRANCE. RI PEYRARD, Michel/C-8494-2014 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 0167-2789 J9 PHYSICA D JI Physica D PD APR 30 PY 1993 VL 64 IS 4 BP 355 EP 364 DI 10.1016/0167-2789(93)90048-6 PG 10 WC Mathematics, Applied; Physics, Multidisciplinary; Physics, Mathematical SC Mathematics; Physics GA LB088 UT WOS:A1993LB08800002 ER PT J AU SUN, ZP SCHUBERT, G GLATZMAIER, GA AF SUN, ZP SCHUBERT, G GLATZMAIER, GA TI BANDED SURFACE FLOW MAINTAINED BY CONVECTION IN A MODEL OF THE RAPIDLY ROTATING GIANT PLANETS SO SCIENCE LA English DT Article ID NUMERICAL SIMULATIONS; DYNAMOS; ZONE AB In three-dimensional numerical simulations of a rapidly rotating Boussinesq fluid shell, thermally driven convection in the form of columns parallel to the rotation axis generates an alternately directed mean zonal flow with a cylindrical structure. The mean structure at the outer spherical surface consists of a broad eastward flow at the equator and alternating bands of westward and eastward flows at higher latitudes in both hemispheres. The banded structure persists even though the underlying convective motions are time-dependent. These results, although still far from the actual motions seen on Jupiter and Saturn, provide support for theoretical suggestions that thermal convection can account for the remarkable banded flow structures on these planets. C1 UNIV CALIF LOS ANGELES, DEPT EARTH & SPACE SCI, LOS ANGELES, CA 90024 USA. UNIV CALIF LOS ANGELES, INST GEOPHYS & PLANETARY PHYS, LOS ANGELES, CA 90024 USA. UNIV CALIF LOS ANGELES, DEPT ATMOSPHER SCI, LOS ANGELES, CA 90024 USA. LOS ALAMOS NATL LAB, DIV EARTH & ENVIRONM SCI, LOS ALAMOS, NM 87545 USA. LOS ALAMOS NATL LAB, INST GEOPHYS & PLANETARY PHYS, LOS ALAMOS, NM 87545 USA. NR 20 TC 51 Z9 51 U1 0 U2 2 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 USA SN 0036-8075 EI 1095-9203 J9 SCIENCE JI Science PD APR 30 PY 1993 VL 260 IS 5108 BP 661 EP 664 DI 10.1126/science.260.5108.661 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA KZ641 UT WOS:A1993KZ64100028 PM 17812225 ER PT J AU YACHANDRA, VK DEROSE, VJ LATIMER, MJ MUKERJI, I SAUER, K KLEIN, MP AF YACHANDRA, VK DEROSE, VJ LATIMER, MJ MUKERJI, I SAUER, K KLEIN, MP TI WHERE PLANTS MAKE OXYGEN - A STRUCTURAL MODEL FOR THE PHOTOSYNTHETIC OXYGEN-EVOLVING MANGANESE CLUSTER SO SCIENCE LA English DT Article ID X-RAY ABSORPTION; WATER OXIDATION CENTER; ELECTRON-PARAMAGNETIC RESONANCE; PHOTOSYSTEM-II; CRYSTAL-STRUCTURE; O-2-EVOLVING COMPLEX; MAGNETIC-PROPERTIES; SPLITTING ENZYME; O-2 EVOLUTION; SPECTROSCOPY AB In the photosynthetic evolution of oxygen, water oxidation occurs at a catalytic site that includes four manganese atoms together with the essential cofactors, the calcium and chlorine ions. A structural model and a determination of the manganese oxidation states based on x-ray absorption spectroscopy are presented. The salient features, in both higher plants and cyanobacteria, are a pair of di-mu-oxo bridged manganese binuclear clusters linked by a mono-mu-oxo bridge, one proximal calcium atom, and one halide. In dark-adapted samples, manganese occurs in oxidation states (III) and (IV). Data from oriented membranes display distinct dichroism, precluding highly symmetrical structures for the manganese complex. C1 LAWRENCE BERKELEY LAB,DIV STRUCT BIOL,BERKELEY,CA 94720. UNIV CALIF BERKELEY,DEPT CHEM,BERKELEY,CA 94720. NR 65 TC 414 Z9 415 U1 4 U2 48 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 SN 0036-8075 J9 SCIENCE JI Science PD APR 30 PY 1993 VL 260 IS 5108 BP 675 EP 679 DI 10.1126/science.8480177 PG 5 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA KZ641 UT WOS:A1993KZ64100033 PM 8480177 ER PT J AU MISKOWSKI, VM RICE, SF GRAY, HB MILDER, SJ AF MISKOWSKI, VM RICE, SF GRAY, HB MILDER, SJ TI EXCITED-STATE DECAY PROCESSES OF BINUCLEAR RHODIUM(I) ISOCYANIDE COMPLEXES SO JOURNAL OF PHYSICAL CHEMISTRY LA English DT Article ID ENERGY-GAP LAW; ELECTRONIC ABSORPTION; NONRADIATIVE DECAY; LARGE MOLECULES; SPECTRA; SPECTROSCOPY; EMISSION AB Emission lifetimes, quantum yields, and polarized excitation spectra of Rh2b42+ and Rh2(TMB)42+ (b = 1,3-diisocyanopropane; TMB = 2,5-diisocyano-2,5-dimethylhexane) have been determined. The singlet and triplet dsigma* --> psigma(1,3A2u) excited states are luminescent with radiative rates of ca. 10(8) and 10(4) s-1, respectively, consistent with values obtained from Strickler-Berg calculations based on the corresponding absorption bands. Both singlet and triplet upper excited states (dpi --> psigma and metal-to-metal charge transfer, E(u) symmetry) undergo nonradiative decay primarily to 3A2u, bypassing 1A2u, and the branching ratios for decay through several intermediate states have been estimated. The temperature dependences of the lifetimes of the 1A2u and 3A2u states of Rh2(TMB)42+ are interpreted in terms of a model in which potential-surface crossings with the B-3(2u). (dsigma* - d(x2-y2)) state facilitate nonradiative decay. C1 CALTECH, ARTHUR AMOS NOYES LAB, PASADENA, CA 91125 USA. BROOKHAVEN NATL LAB, DEPT CHEM, UPTON, NY 11973 USA. NR 36 TC 22 Z9 22 U1 2 U2 4 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0022-3654 J9 J PHYS CHEM-US JI J. Phys. Chem. PD APR 29 PY 1993 VL 97 IS 17 BP 4277 EP 4283 DI 10.1021/j100119a007 PG 7 WC Chemistry, Physical SC Chemistry GA LA023 UT WOS:A1993LA02300007 ER PT J AU FALKOWSKI, PG WILSON, C AF FALKOWSKI, PG WILSON, C TI PHYTOPLANKTON PRODUCTIVITY - REPLY SO NATURE LA English DT Letter ID OCEAN RP FALKOWSKI, PG (reprint author), BROOKHAVEN NATL LAB,DIV OCEANOG & ATMOSPHER SCI,UPTON,NY 11973, USA. RI Wilson, Cara/A-8816-2009; OI Wilson, Cara/0000-0001-9318-2322 NR 13 TC 2 Z9 2 U1 0 U2 5 PU MACMILLAN MAGAZINES LTD PI LONDON PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW SN 0028-0836 J9 NATURE JI Nature PD APR 29 PY 1993 VL 362 IS 6423 BP 796 EP 796 DI 10.1038/362796a0 PG 1 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA KZ563 UT WOS:A1993KZ56300038 ER PT J AU CHEN, CH DEPAOLO, DJ NAKADA, S SHIEH, YN AF CHEN, CH DEPAOLO, DJ NAKADA, S SHIEH, YN TI RELATIONSHIP BETWEEN ERUPTION VOLUME AND NEODYMIUM ISOTOPIC COMPOSITION AT UNZEN VOLCANO SO NATURE LA English DT Article ID RHYOLITIC MAGMA; JAPAN; INTRUSION; CHAMBERS; ROCKS; AREA AB SILICA-rich lavas, erupted at island-arc or continental volcanoes, are often produced by a complex process involving the assimilation of crust into a crystallizing, mantle-derived basaltic magma1. The different strontium, neodymium and oxygen isotopic compositions of mantle-derived magmas and continental crust provide a powerful method for tracing the different contributions to continental silicic magmas, and for understanding the parameters controlling the composition and volume of erupted magma1-4. In the large rhyolite eruptive centres of the western United States, the largest-volume, explosive rhyolite eruptions have more mantle-like Nd isotope ratios than other silicic lavas from the same centre2-4, a relationship that has been interpreted as reflecting increased influx of mantle-derived basaltic magma to a crustal magma chamber before large-volume eruptions1. Here we report isotope data for lavas from Unzen volcano, which suggest a similar relationship: the Nd isotope composition is more mantle-like in three larger-volume dacite eruptions (>0.1 km3) than in one small-volume (0.02 km3) eruption. We accordingly suggest that, in small-volume systems like Unzen, where the timescales for magma-chamber evolution are of the order of decades, isotope data such as those presented here might be used in volcanic hazard evaluation. C1 LAWRENCE BERKELEY LAB,DIV EARTH SCI,BERKELEY,CA 94720. ACAD SINICA,INST EARTH SCI,TAIPEI 10764,TAIWAN. KYUSHU UNIV,DEPT EARTH & PLANETARY SCI,FUKUOKA 812,JAPAN. PURDUE UNIV,DEPT EARTH & ATMOSPHER SCI,W LAFAYETTE,IN 47907. RP CHEN, CH (reprint author), UNIV CALIF BERKELEY,DEPT GEOL & GEOPHYS,CTR ISOTOPE GEOCHEM,BERKELEY,CA 94720, USA. NR 23 TC 21 Z9 21 U1 0 U2 3 PU MACMILLAN MAGAZINES LTD PI LONDON PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW SN 0028-0836 J9 NATURE JI Nature PD APR 29 PY 1993 VL 362 IS 6423 BP 831 EP 834 DI 10.1038/362831a0 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA KZ563 UT WOS:A1993KZ56300053 ER PT J AU BERGER, EL MENG, R AF BERGER, EL MENG, R TI LONGITUDINAL STRUCTURE-FUNCTION AT INTERMEDIATE-X AND THE GLUON DENSITY SO PHYSICS LETTERS B LA English DT Article ID INELASTIC MUON SCATTERING; TRANSVERSE-MOMENTUM; 280 GEV/C; HIGH Q2; PROTON AB Calculations are presented of the longitudinal structure function F(L) (x, Q2). We use next-to-leading order expressions in QCD (O(alpha(s)2)) plus parton densities determined previously from global fits to data on deep inelastic lepton scattering, prompt photon production, and bottom quark production. Anticipated data from the DESY ep collider HERA should provide discriminating information on the gluon density, particularly for values of x < 0.05. C1 ARGONNE NATL LAB, DIV HIGH ENERGY PHYS, ARGONNE, IL 60439 USA. RP CERN, CH-1211 GENEVA 23, SWITZERLAND. OI Meng, Ruibin/0000-0002-4846-4619 NR 32 TC 13 Z9 13 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0370-2693 EI 1873-2445 J9 PHYS LETT B JI Phys. Lett. B PD APR 29 PY 1993 VL 304 IS 3-4 BP 318 EP 322 DI 10.1016/0370-2693(93)90302-X PG 5 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA KZ791 UT WOS:A1993KZ79100022 ER PT J AU SEVOV, SC CORBETT, JD AF SEVOV, SC CORBETT, JD TI SYNTHESIS, CHARACTERIZATION, AND BONDING OF INDIUM CLUSTERS - A3NA26IN48 (A = K, RB, CS) WITH A NOVEL CUBIC NETWORK OF ARACHNO-IN12 AND CLOSO-IN12 CLUSTERS SO INORGANIC CHEMISTRY LA English DT Article ID CRYSTAL-STRUCTURE AB The title compounds are obtained in high yield by slow cooling of the appropriate fused mixture of elements in welded Ta. They occur in the cubic space group Pm3nBAR, Z = 2, with a = 16.0640(4), 16.101(l), 16.130(i) angstrom for A = K, Rb, Cs, respectively. The structure was refined by single-crystal means for A = K, Rb to R, R(w) = 2.5, 3.3 and 2.0, 2.5%. The structure contains closo-In12 icosahedra (T(h) symmetry) plus arachno-In12 (D2d) as approximate (D6d) hexagonal antiprisms (drums) with 12 exo In-In bonds about each cluster. Nonintersecting chains of ''drums'' lie in the faces of the cubic cell and parallel to the cell edges. Adjacent arachno clusters are interconnected only indirectly at chain crossings via the closo polyhedra that define a body-centered cube. The structure is A15 (Cr3-Si)-like with arachno- and closo-In12 clusters, respectively, replacing the metal and non-metal atoms of the parent. The larger A cations order in, and appear required for, the larger cavities lying betwen drums in each chain. The compounds are electron-rich by 5.5% according to theory, and the potassium example is metallic (rho295 approximately 23 muOMEGA cm) and Pauli paramagnetic (2.2 x 10(-3) emu mol-1) by measurement. C1 IOWA STATE UNIV SCI & TECHNOL,US DOE,AMES LAB,AMES,IA 50011. IOWA STATE UNIV SCI & TECHNOL,DEPT CHEM,AMES,IA 50011. NR 23 TC 41 Z9 41 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 APR 28 PY 1993 VL 32 IS 9 BP 1612 EP 1615 DI 10.1021/ic00061a016 PG 4 WC Chemistry, Inorganic & Nuclear SC Chemistry GA KZ801 UT WOS:A1993KZ80100016 ER PT J AU SENGE, MO MEDFORTH, CJ SPARKS, LD SHELNUTT, JA SMITH, KM AF SENGE, MO MEDFORTH, CJ SPARKS, LD SHELNUTT, JA SMITH, KM TI A PLANAR DODECASUBSTITUTED PORPHYRIN SO INORGANIC CHEMISTRY LA English DT Article ID LIGHT-ABSORPTION PROPERTIES; RESONANCE RAMAN-SPECTRA; PHOTOSYNTHETIC CHROMOPHORES; NICKEL(II) PORPHYRINS; MOLECULAR-STRUCTURE; DODECAPHENYLPORPHYRIN; COMPLEXES; MODELS; OCTAETHYLPORPHYRIN; CONSEQUENCES AB Structural investigations of copper and nickel complexes of dodecasubstituted porphyrins bearing aryl groups at the meso positions and propano rings at the pyrrole beta positions reveal considerable differences in their macrocycle conformations. While the nickel complex NiTC5T(3,4,5-OMeP)P was found to exhibit a nonplanar conformation which is considerably more planar than that of other dodecasubstituted porphyrins, the corresponding copper complex CuTC5T(3,4,5-OMeP)P was planar. CuTC5T(3,4,5-OMeP)P thus represents the first example of a completely planar dodecasubstituted porphyrin. The crystal structures of both porphyrins reveal that the Cb-Cb-CH2 angle is 13-degrees smaller than in OEP derivatives. This change, which moves the methylene and aryl substituents further apart, effectively removes the steric repulsion responsible for the very nonplanar conformations observed for other dodecasubstituted porphyrins. Molecular mechanics calculations using a porphyrin force field correctly predict a planar macrocycle conformation. The possible reasons for the discrepancy between the observed moderately nonplanar structure and the calculated planar structure for NiTC5T(3,4,5-OMeP)P are discussed. The usefulness of spectroscopic probes (NMR, resonance Raman, electronic absorption) in predicting the planarity of dodecasubstituted porphyrins is also examined. The identification of a planar dodecasubstituted porphyrin further indicates the flexibility of the tetrapyrrole macrocycle and has implications for the study of nonplanarity in synthetic porphyrins and metallotetrapyrrole containing biomolecules. Crystal data: NiTC5T(3,4,5-OMeP)P.2CH2Cl2 (C68H68N4NiO12.2CH2Cl2), triclinic, P1BAR, a = 14.492(8) angstrom, b = 14.453(8) angstrom, c = 17.689(10) angstrom, alpha = 103.11(5)-degrees, beta = 113.58(4)-degrees, gamma = 89.93(5)-degrees, V = 3290(3) angstrom3, Z = 2, lambda(mo Kalpha) = 0.7107 angstrom, T = 130 K, R = 0.06 for 7657 reflections with I > 2.5sigma(I); CuTC5T(3,4,5-OMeP)P.CH2Cl2 (C68H68N4CuO12.CH2Cl2), monoclinic, P2(1)/c, a = 14.459(4) angstrom, b = 15.302(6) angstrom, c = 14.879(4) angstrom, beta = 100.68(4)-degrees, V = 3235(2) angstrom3, Z = 2, lambda(Mo Kalpha) = 0.7107 angstrom, T = 130 K, R = 0. 106 for 4222 reflections with I > 2.0 sigma(I). C1 SANDIA NATL LABS,DEPT FUEL SCI 6211,ALBUQUERQUE,NM 87185. UNIV CALIF DAVIS,DEPT CHEM,DAVIS,CA 95616. UNIV NEW MEXICO,DEPT CHEM,ALBUQUERQUE,NM 87185. 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 55 TC 69 Z9 69 U1 0 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0020-1669 J9 INORG CHEM JI Inorg. Chem. PD APR 28 PY 1993 VL 32 IS 9 BP 1716 EP 1723 DI 10.1021/ic00061a030 PG 8 WC Chemistry, Inorganic & Nuclear SC Chemistry GA KZ801 UT WOS:A1993KZ80100030 ER PT J AU CLARK, DL WATKIN, JG AF CLARK, DL WATKIN, JG TI SYNTHESIS AND CHARACTERIZATION OF THORIUM TERT-BUTOXIDE COMPLEXES - X-RAY CRYSTAL-STRUCTURES OF TH(O-T-BU)4(PY)2 AND NATH2(O-T-BU)9 SO INORGANIC CHEMISTRY LA English DT Article ID HYDROGEN-DEUTERIUM EXCHANGE; HETEROMETALLIC ALKOXIDES; MOLECULAR-STRUCTURE; CHEMISTRY; YTTRIUM; URANIUM(IV); DERIVATIVES; REACTIVITY; INSERTION; BONDS AB Two synthetic procedures have been employed for the preparation of thorium tert-butoxide complexes. Reaction of ThI4(THF)4 with 4 equiv of KO-t-Bu in THF/pyridine solution provides Th(O-t-Bu)4(py)2 (1) in moderate yield. Alcoholysis of the thorium metallacycle [{(Me3Si)2N}2Th(CH2SiMe2NSiMe3)] with >4 equiv of HO-t-Bu produces the dimeric alcoholate Th2(O-t-Bu)8(HO-t-Bu) (2) in 70% isolated yield. The coordinated alcohol in 2 is readily deprotonated by employing NaN(SiMe3)2 in hexane solution to provide hexane-soluble NaTh2(O-t-Bu)9 (3) in ca. 70% yield. Formation of the trimeric complex Th3O(O-t-Bu)10 (4) occurs upon addition of stoichiometric amounts of H2O to refluxing toluene solutions of 2. Compounds 1-4 have been characterized by elemental analysis, H-1 NMR, infrared spectroscopy, and, for 1 and 3, single-crystal X-ray diffraction. In 1, the Th atom is coordinated to four alkoxide and two pyridine ligands in a cis pseudo-octahedral fashion with average Th-O and Th-N distances of 2.182(6) and 2.752(7) angstrom, respectively. In 3, the NaTh2(O-t-Bu)9 unit is closely related to the well-known M3X11 cluster and is best described as NaTh2(mu3-O-t-Bu)2(mu2-O-t-Bu)3(O-t-Bu)4. Averaged Na-mu3-O and Na-mu2-O distances are 2.399(17) and 2.607(10) angstrom, respectively. Th-O distances are 2.155(8), 2.280(10), 2.464(7), and 2.491(7) angstrom for terminal, doubly bridging to sodium, doubly bridging to thorium, and triply bridging alkoxides, respectively. Crystal data for 1 (at 25-degrees-C): Monoclinic space group C2/c, with a = 12.656(3) angstrom, b = 15.326(3), c = 16.803(3) angstrom, beta = 96.43(3)-degrees, V = 3238.7(12) angstrom3, d(calc) = 1.363 g cm-3, and Z = 4. Crystal data for 3 (at 25-degrees-C): Orthorhombic space group Pnma, with a = 11. 170(2) angstrom, b = 25.408(5), c = 17.195(3) angstrom, V = 4880.1(16) angstrom3, d(calc) = 1.559 g cm-3, and Z = 4. RP CLARK, DL (reprint author), LOS ALAMOS NATL LAB,DIV ISOTOPE & NUCL CHEM,MAIL STOP G739,LOS ALAMOS,NM 87545, USA. RI Clark, David/A-9729-2011 NR 51 TC 51 Z9 51 U1 0 U2 2 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0020-1669 J9 INORG CHEM JI Inorg. Chem. PD APR 28 PY 1993 VL 32 IS 9 BP 1766 EP 1772 DI 10.1021/ic00061a037 PG 7 WC Chemistry, Inorganic & Nuclear SC Chemistry GA KZ801 UT WOS:A1993KZ80100037 ER PT J AU HINES, MA SULLIVAN, JC NASH, KL AF HINES, MA SULLIVAN, JC NASH, KL TI KINETICS OF THE COMPLEXATION OF DIOXOURANIUM(VI) WITH SELECTED DIPHOSPHONIC ACIDS IN ACIDIC SOLUTIONS SO INORGANIC CHEMISTRY LA English DT Article ID ARSENAZO-III; STABILITY; ION AB The kinetics of reactions of dioxouranium(VI) with diphosphonic acid complexants (methanediphosphonic acid (MDPA), 1-hydroxyethane-1,1-diphosphonic acid (HEDPA), and ethane-1,2-diphosphonic acid (E12DPA)) have been investigated in acidic solutions (pH 1-2) by stopped-flow spectrophotometry where arsenazo III is used as an indicator for the free uranyl ion. The complex formation reaction was acid independent at acidities above 0.03 M while the dissociation reaction had a direct dependence on the acidity over the range of hydrogen ion concentration 0.1-0.01 M. The measured first-order rate parameter is defined as k(obs) = k(f)[UO22+] [H3L] + kd[UO2H2L] [H+]. The rate parameters for formation and dissociation reactions at 25.0-degrees-C are as follows. Uranyl-MDPA: k(f) = 6813 (+/- 320) M-1 s-1, k(d) = 31.3 +/- 2.1) s-1. Uranyl-HEDPA: k(f) = 7715 (+/- 146) M-1 s-1, k(d) = 27.5 (12.0) s-1. Uranyl-E12DPA: k(f) = 216 (+/- 24) M-1 s-1, k(d) = 47.4 (+/- 2.6) s-1. The equilibrium quotient calculated from the rate parameters for the formation of uranyl-E12DPA is in agreement with the previously reported stability constant for that complex. Activation parameters for both formation and dissociation reactions are consistent with an associative mechanism. Uranyl-MDPA: DELTAH(f)* = 38.0 (+/- 1.4) kJ/mol, DELTAS(f)* = -44 (+/-4) J/(mol K), DELTAH(d)* = 44.8 (+/- 2.4) kJ/mol, DELTAS(d)* = -66 (+/- 8) J/(mol K). Uranyl-HEDPA: DELTAH(f)* = 38.8 (+/- 0.6) kJ/mol, DELTAS(f)* = -40 (+/- 2) J/(mol K), DELTAH(d)* = 57.8 (+/- 20.9) kJ/mol, DELTAS(d)* = -22 (4-62) J/(mol K). Uranyl-E12DPA: DELTAH(f)* = 46.8 (+/- 0.1) kJ/mol, DELTAS(f)* = -43 (+/- 1) J/(mol K), DELTAH(d)* = 44.2 (+/- 4.1) kJ/mol, DELTAS(d)* = -65 (+/- 13) J/(mol K). C1 ARGONNE NATL LAB,9700 S CASS AVE,ARGONNE,IL 60439. NR 15 TC 21 Z9 21 U1 0 U2 3 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0020-1669 J9 INORG CHEM JI Inorg. Chem. PD APR 28 PY 1993 VL 32 IS 9 BP 1820 EP 1823 DI 10.1021/ic00061a045 PG 4 WC Chemistry, Inorganic & Nuclear SC Chemistry GA KZ801 UT WOS:A1993KZ80100045 ER PT J AU BENSON, JW ANGELICI, RJ AF BENSON, JW ANGELICI, RJ TI REACTIONS OF 2-BENZO[B]THIENYL (2-BTYL) COMPLEXES WITH ACID TO GIVE CP(PME3)2RU(ETA-1(S)-BT)+ AND CP(CO)(PPH3)RU(ETA-1(S)-BT)+ - A MODEL FOR BENZO[B]THIOPHENE (BT) DEUTERIUM-EXCHANGE ON HYDRODESULFURIZATION CATALYSTS SO INORGANIC CHEMISTRY LA English DT Note ID COO-MOO3-AL2O3 CATALYST; IRIDIUM COMPLEXES; HALIDE ION; BENZOTHIOPHENE; RUTHENIUM; THIOPHENE; CYCLOPENTADIENYLRUTHENIUM; DIBENZOTHIOPHENE; DERIVATIVES; REACTIVITY C1 IOWA STATE UNIV SCI & TECHNOL,AMES LAB,AMES,IA 50011. NR 41 TC 28 Z9 28 U1 0 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0020-1669 J9 INORG CHEM JI Inorg. Chem. PD APR 28 PY 1993 VL 32 IS 9 BP 1871 EP 1874 DI 10.1021/ic00061a056 PG 4 WC Chemistry, Inorganic & Nuclear SC Chemistry GA KZ801 UT WOS:A1993KZ80100056 ER PT J AU BENTAL, N MOISEYEV, N KOSLOFF, R CERJAN, C AF BENTAL, N MOISEYEV, N KOSLOFF, R CERJAN, C TI HARMONIC-GENERATION IN IONIZING SYSTEMS BY THE TIME-DEPENDENT COMPLEX COORDINATE FLOQUET METHOD SO JOURNAL OF PHYSICS B-ATOMIC MOLECULAR AND OPTICAL PHYSICS LA English DT Article ID ABOVE-THRESHOLD IONIZATION; MULTIPHOTON IONIZATION; PERIODIC HAMILTONIANS; SCHRODINGER-EQUATION; PERTURBATION-THEORY; PARTIAL WIDTHS; HYDROGEN-ATOM; RARE-GASES; MODEL ATOM; LASER AB The time-dependent complex coordinate Floquet method was developed for the study of non-linear phenomena observed for atoms (or small molecules) in strong laser fields. On the basis of this method and by taking use of the special definition of the inner product for non-Hermitian operators a simple time-independent expression for the probability to obtain high harmonics was derived. This novel formula is used to investigate the phenomenon of harmonic generation for a model potential representing a single electron in the presence of an intense laser field. The parameters of the one-dimensional potential are chosen to fit two electronic states of the xenon atom. Numerical results indicate the existence of a correlation between harmonic generation and other non-linear effects occurring in this system such as avoided crossings of Floquet resonance states as the field strength amplitude is varied. The harmonic generation spectra obtained by the model presented here qualitatively agree with experimental results on rare gas atoms placed in strong laser fields. For strong laser fields (> 10(14) W cm-2), very-high-order harmonic generation is observed in numerical studies using both complex Floquet analysis and a simulation by a pseudo-spectral grid solution to the time-dependent Schrodinger equation with a non-periodic Hamiltonian. For extremely strong laser fields, numerical results predict that the most intense frequency emitted by an atom interacting with a monochromatic laser field might not be the irradiating laser frequency, but rather a high multiple of it. C1 LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550. HEBREW UNIV JERUSALEM,FRITZ HABER RES CTR MOLEC DYNAM,IL-91904 JERUSALEM,ISRAEL. RP BENTAL, N (reprint author), TECHNION ISRAEL INST TECHNOL,DEPT CHEM,IL-32000 HAIFA,ISRAEL. RI Kosloff, Ronnie/D-2388-2013 OI Kosloff, Ronnie/0000-0001-6201-2523 NR 54 TC 43 Z9 43 U1 0 U2 1 PU IOP PUBLISHING LTD PI BRISTOL PA TECHNO HOUSE, REDCLIFFE WAY, BRISTOL, ENGLAND BS1 6NX SN 0953-4075 J9 J PHYS B-AT MOL OPT JI J. Phys. B-At. Mol. Opt. Phys. PD APR 28 PY 1993 VL 26 IS 8 BP 1445 EP 1461 DI 10.1088/0953-4075/26/8/012 PG 17 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA LE976 UT WOS:A1993LE97600012 ER PT J AU NILSEN, J PORTER, JL MACGOWAN, BJ DASILVA, LB MORENO, JC AF NILSEN, J PORTER, JL MACGOWAN, BJ DASILVA, LB MORENO, JC TI NEON-LIKE X-RAY LASERS OF ZIRCONIUM, NIOBIUM AND BROMINE SO JOURNAL OF PHYSICS B-ATOMIC MOLECULAR AND OPTICAL PHYSICS LA English DT Letter AB We demonstrate three new x-ray lasers in neon-like zirconium, niobium and bromine which lase on 3p --> 3s transitions. By observing the wavelengths and relative intensity of the lasing lines we hope to shed some light on the anomalous lasing in neon-like yttrium, where one laser line dominates the spectrum. In this work we report the wavelengths of five new lasing lines in bromine and six lasing lines each in zirconium and niobium. RP NILSEN, J (reprint author), LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550, USA. NR 9 TC 15 Z9 15 U1 0 U2 3 PU IOP PUBLISHING LTD PI BRISTOL PA TECHNO HOUSE, REDCLIFFE WAY, BRISTOL, ENGLAND BS1 6NX SN 0953-4075 J9 J PHYS B-AT MOL OPT JI J. Phys. B-At. Mol. Opt. Phys. PD APR 28 PY 1993 VL 26 IS 8 BP L243 EP L247 DI 10.1088/0953-4075/26/8/006 PG 5 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA LE976 UT WOS:A1993LE97600006 ER PT J AU COSMAN, M DELOSSANTOS, C FIALA, R HINGERTY, BE IBANEZ, V LUNA, E HARVEY, R GEACINTOV, NE BROYDE, S PATEL, DJ AF COSMAN, M DELOSSANTOS, C FIALA, R HINGERTY, BE IBANEZ, V LUNA, E HARVEY, R GEACINTOV, NE BROYDE, S PATEL, DJ TI SOLUTION CONFORMATION OF THE (+)-CIS-ANTI-[BP]DG ADDUCT IN A DNA DUPLEX - INTERCALATION OF THE COVALENTLY ATTACHED BENZO[A]PYRENYL RING INTO THE HELIX AND DISPLACEMENT OF THE MODIFIED DEOXYGUANOSINE SO BIOCHEMISTRY LA English DT Article ID BENZO(A)PYRENE DIOL-EPOXIDE; OPTICAL ENANTIOMERS; NUCLEIC-ACIDS; 7,8-DIOL-9,10-EPOXIDES; CARCINOGEN; BINDING; POLYNUCLEOTIDES; STEREOISOMERS; 9,10-EPOXIDES; ONCOGENES AB This paper reports on the solution structure of the (+)-cis-anti-[BP]dG adduct positioned opposited C in a DNA oligomer duplex which provides the first experimentally based solution structure of an intercalative complex of a polycyclic aromatic hydrocarbon covalently bound to the N2 of deoxyguanosine. The combined NMR-energy minimization computation studies were undertaken on the (+)-cis-anti-[BP]dG adduct embedded in the same d(C5-[BP]G6-C7).d(G16-C17-G18) trinucleotide segment of the complementary 11-mer duplex studied previously with the stereoisomeric trans adducts. The exchangeable and nonexchangeable protons of the benzo[a]pyrenyl moiety and the nucleic acid were assigned following analysis of two-dimensional NMR data sets in H2O and D2O solution. The solution structure of the (+)-cis-anti-[BP]dG.dC 11-mer duplex has been determined by incorporating intramolecular and intermolecular proton-proton distances defined by upper and lower bounds deduced from NOESY data sets as restraints in energy minimization computations. The benzo[a]pyrene ring of [BP]dG6 is intercalated between intact Watson-Crick dC5.dG18 and dC7.dG16 base pairs in a right-handed DNA helix. The benzylic ring is in the minor groove while the pyrenyl ring stacks with flanking dC5 and dC7 bases on the same strand. The deoxyguanosine ring of [BP]dG6 is not Watson-Crick base paired but displaced into the minor groove with its plane parallel to the helix axis and stacks over the sugar ring of dC5. The dC17 base on the partner strand is displaced from the center of the helix toward the major groove by the intercalated benzo[a]pyrene ring. This intercalative structure of the (+)-cis-anti-[BP]dG-dC 11-mer duplex exhibits several unusually shifted proton resonances which can be readily accounted for by the ring current contributions of the deoxyguanosine and pyrenyl rings of the [BP]dG6 adduct. Several phosphorus resonances are shifted to low and high field of the unperturbed phosphorus spectral region and have been assigned to internucleotide phosphates centered about the [BP]dG6 modification site. These studies define the changes in the helix at the central trinucleotide segment needed to generate the intercalation site for the covalently bound (+)-cis-anti-[BP]dG adduct. Our structural studies to date permit the classification of [BP]dG adducts positioned opposite dC in DNA helices as either site II solvent-exposed structures with intact [BP]dG.dC Watson-Crick pairing as observed for the (+)-trans-anti-[BP]dG adduct [Cosman et al. (1992) Proc. Natl. Acad. Sci. U.S.A. 89, 1914-1918] and (-)-trans-anti-[BP]dG adduct [De los Santos et al. (1992) Biochemistry 31, 5245-5252] or site I intercalative structures in which the deoxyguanosine ring of [BP]dG and dC are displaced into opposite grooves and the benzo[a]pyrene ring intercalates into the helix as observed for the (+)-cis-anti-[BP]dG adduct in this study. C1 MEM SLOAN KETTERING CANC CTR,ROCKEFELLER RES LABS,CELLULAR BIOCHEM & BIOPHYS PROGRAM,NEW YORK,NY 10021. OAK RIDGE NATL LAB,DIV HLTH & SAFETY RES,OAK RIDGE,TN 37831. UNIV CHICAGO,BEN MAY INST,CHICAGO,IL 60637. NYU,DEPT CHEM,NEW YORK,NY 10003. NYU,DEPT BIOL,NEW YORK,NY 10003. RP COSMAN, M (reprint author), COLUMBIA UNIV COLL PHYS & SURG,DEPT BIOCHEM & MOLEC BIOPHYS,NEW YORK,NY 10032, USA. RI Fiala, Radovan/D-8789-2012 FU NCI NIH HHS [CA-09503, CA-46533, CA-21111] NR 50 TC 141 Z9 142 U1 0 U2 2 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0006-2960 J9 BIOCHEMISTRY-US JI Biochemistry PD APR 27 PY 1993 VL 32 IS 16 BP 4145 EP 4155 DI 10.1021/bi00067a001 PG 11 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA KZ246 UT WOS:A1993KZ24600001 PM 8476845 ER PT J AU WILKERSON, CW GOODWIN, PM AMBROSE, WP MARTIN, JC KELLER, RA AF WILKERSON, CW GOODWIN, PM AMBROSE, WP MARTIN, JC KELLER, RA TI DETECTION AND LIFETIME MEASUREMENT OF SINGLE MOLECULES IN FLOWING SAMPLE STREAMS BY LASER-INDUCED FLUORESCENCE SO APPLIED PHYSICS LETTERS LA English DT Article AB The detection and measurement of fluorescence lifetimes of single Rhodamine-110 molecules in a flowing, aqueous sample stream is described. Time-correlated single-photon counting, used in combination with mode-locked picosecond pulsed excitation, allows the detection of single fluorescent molecules in the presence of significant solvent Raman and Rayleigh backgrounds. The fluorescence lifetime of a detected molecule is estimated from the record of arrival times (relative to the excitation pulse) of photons detected during the molecule's passage through the approximately 1 pL excitation volume. C1 LOS ALAMOS NATL LAB,DIV LIFE SCI,LOS ALAMOS,NM 87545. RP WILKERSON, CW (reprint author), LOS ALAMOS NATL LAB,CTR HUMAN GENOME STUDIES,DIV CHEM & LASER SCI,LOS ALAMOS,NM 87545, USA. NR 5 TC 95 Z9 96 U1 0 U2 8 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD APR 26 PY 1993 VL 62 IS 17 BP 2030 EP 2032 DI 10.1063/1.109495 PG 3 WC Physics, Applied SC Physics GA KY864 UT WOS:A1993KY86400010 ER PT J AU CHEUNG, JT MORGAN, PED LOWNDES, DH ZHENG, XY BREEN, J AF CHEUNG, JT MORGAN, PED LOWNDES, DH ZHENG, XY BREEN, J TI STRUCTURAL AND ELECTRICAL-PROPERTIES OF LA0.5SR0.5COO3 EPITAXIAL-FILMS SO APPLIED PHYSICS LETTERS LA English DT Article ID GROWTH; SUPERCONDUCTORS AB Epitaxial La0.5Sr0.5CoO3 films with very smooth surface morphology were grown on (100) SrTiO3 and (100) MgO substrates by pulsed laser deposition. Scanning tunneling microscopy reveals that the thin film is formed by the coalescence of many aligned square mesas. The growth proceeds from the edges of terraces which are stacked on the mesa. Spiral growth is never observed. Films display an crystallographically isotropic metallic-like electrical conductivity but become semiconductor-like after vacuum annealing. The energy for carrier activation is 0.3 eV. The change of the electrical resistivity of La0.5Sr0.5CoO3 with oxygen pressure at high temperature is much less sensitive than that of YBa2Cu3O7-x. C1 OAK RIDGE NATL LAB,DIV SOLID STATE,OAK RIDGE,TN 37831. INDIANA UNIV PURDUE UNIV,DEPT CHEM,INDIANAPOLIS,IN 46202. RP CHEUNG, JT (reprint author), ROCKWELL INT SCI CTR,POB 1085,THOUSAND OAKS,CA 91360, USA. NR 13 TC 155 Z9 160 U1 3 U2 15 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD APR 26 PY 1993 VL 62 IS 17 BP 2045 EP 2047 DI 10.1063/1.109474 PG 3 WC Physics, Applied SC Physics GA KY864 UT WOS:A1993KY86400015 ER PT J AU DENLINGER, JD ROTENBERG, E HESSINGER, U LESKOVAR, M OLMSTEAD, MA AF DENLINGER, JD ROTENBERG, E HESSINGER, U LESKOVAR, M OLMSTEAD, MA TI VARIABLE GROWTH MODES OF CAF2 ON SI(111) DETERMINED BY X-RAY PHOTOELECTRON DIFFRACTION SO APPLIED PHYSICS LETTERS LA English DT Article ID CAF2/SI(111) INTERFACE; INSULATORS; SCATTERING; FILMS AB Chemical discrimination of bulk and interface Ca 2p x-ray photoelectron diffraction modulations is used to identify three growth regimes during the initial stages of CaF2 epitaxy on Si(111). Low flux, high temperature conditions produce island growth atop a nonwetting, chemically reacted Ca-F interface layer. Changing the growth kinetics by increasing the flux produces more laminar growth. Lowering the substrate temperature produces a more stoichiometric CaF2 interface layer that results in immediate wetting and laminar growth. C1 LAWRENCE BERKELEY LAB,DIV MAT SCI,BERKELEY,CA 94720. UNIV WASHINGTON,DEPT PHYS FM15,SEATTLE,WA 98195. RP DENLINGER, JD (reprint author), UNIV CALIF BERKELEY,DEPT PHYS,BERKELEY,CA 94720, USA. RI Rotenberg, Eli/B-3700-2009; OI Rotenberg, Eli/0000-0002-3979-8844; Olmstead, Marjorie/0000-0003-4374-0976 NR 15 TC 30 Z9 30 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 APR 26 PY 1993 VL 62 IS 17 BP 2057 EP 2059 DI 10.1063/1.109478 PG 3 WC Physics, Applied SC Physics GA KY864 UT WOS:A1993KY86400019 ER PT J AU BLACK, RC MATHAI, A WELLSTOOD, FC DANTSKER, E MIKLICH, AH NEMETH, DT KINGSTON, JJ CLARKE, J AF BLACK, RC MATHAI, A WELLSTOOD, FC DANTSKER, E MIKLICH, AH NEMETH, DT KINGSTON, JJ CLARKE, J TI MAGNETIC MICROSCOPY USING A LIQUID-NITROGEN COOLED YBA2CU3O7 SUPERCONDUCTING QUANTUM INTERFERENCE DEVICE SO APPLIED PHYSICS LETTERS LA English DT Article AB We have developed a magnetic flux microscope which uses a liquid nitrogen cooled thin-film YBa2Cu3O7 dc superconducting quantum interference device (SQUID) to produce two-dimensional images of magnetic fields. The instrument operates as a scanning probe microscope with a spatial resolution of about 80 mum and a field of view of about 100 mm2. The equivalent magnetic field noise in the SQUID ranges from 80 pT Hz-1/2 at 1 Hz to 20 pT Hz-1/2 at 1 kHz, yielding a field resolution of about 200 pT in our images. We have used the microscope to image magnetic domains in ferromagnetic samples, small currents flowing in fine wires, and trapped flux and diamagnetic susceptibility in superconducting thin films. C1 UNIV CALIF BERKELEY,DEPT PHYS,BERKELEY,CA 94720. LAWRENCE BERKELEY LAB,DIV MAT SCI,BERKELEY,CA 94720. RP BLACK, RC (reprint author), UNIV MARYLAND,DEPT PHYS,CTR SUPERCONDUCT RES,COLL PK,MD 20742, USA. RI Joint Quantum Institute, NIST/UMD/H-4494-2011 NR 15 TC 110 Z9 110 U1 0 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 APR 26 PY 1993 VL 62 IS 17 BP 2128 EP 2130 DI 10.1063/1.109448 PG 3 WC Physics, Applied SC Physics GA KY864 UT WOS:A1993KY86400043 ER PT J AU FU, YG BUSING, WR JIN, YM AFFHOLTER, KA WUNDERLICH, B AF FU, YG BUSING, WR JIN, YM AFFHOLTER, KA WUNDERLICH, B TI POLY(ETHYLENE-TEREPHTHALATE) FIBERS .1. CRYSTAL-STRUCTURE AND MORPHOLOGY STUDIES WITH FULL-PATTERN X-RAY-DIFFRACTION REFINEMENT SO MACROMOLECULES LA English DT Article ID OLIGOMETHYLENE GLYCOL DERIVATIVES; ISOTACTIC POLYPROPYLENE; RIETVELD REFINEMENTS; MOLECULAR-STRUCTURE; POLY(ETHYLENE-TEREPHTHALATE); SCATTERING; DISORDER; STATE; DRAWN AB Full-pattern fiber X-ray diffraction refinement has been used to study the structure and morphology of the crystallites of three poly(ethylene terephthalate) fiber samples with different heat treatment history. Diffraction data over the whole two-dimensional space were collected with a four-circle diffractometer. An iterative Fourier filter method is developed to separate the crystalline diffraction from the background scattering. Both the structure and morphology are found to be dependent on the heat treatment. Some properties of the fibers can be explained by the difference in the crystal structure and morphology of crystallites. C1 UNIV TENNESSEE, DEPT CHEM, KNOXVILLE, TN 37996 USA. OAK RIDGE NATL LAB, DIV CHEM, OAK RIDGE, TN 37831 USA. OAK RIDGE NATL LAB, DIV CHEM TECHNOL, OAK RIDGE, TN 37831 USA. NR 39 TC 49 Z9 49 U1 1 U2 8 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0024-9297 EI 1520-5835 J9 MACROMOLECULES JI Macromolecules PD APR 26 PY 1993 VL 26 IS 9 BP 2187 EP 2193 DI 10.1021/ma00061a007 PG 7 WC Polymer Science SC Polymer Science GA KZ776 UT WOS:A1993KZ77600007 ER PT J AU SUNDRUM, R AF SUNDRUM, R TI A REALISTIC TECHNICOLOR MODEL FROM 150 TEV DOWN SO NUCLEAR PHYSICS B LA English DT Article ID ELECTROWEAK SYMMETRY-BREAKING; CHANGING NEUTRAL CURRENTS; RADIATIVE-CORRECTIONS; CHIRAL HIERARCHIES; PARAMETERS; MASS; HYPERCOLOR; ALIGNMENT; DYNAMICS AB A realistic technicolor model is presented with the dynamics below 150 TeV treated explicitly. Electroweak symmetry is broken by the condensates of a ''minimal'' doublet of technifermions. The new feature of the model is that the the third generation quarks are unified with the technifermions into multiplets of a walking gauge force down to a scale of 10 TeV. The remaining quarks and leptons are not involved in this unification however. The walking dynamics enhances the higher dimension interactions which give the ordinary fermions their masses and mixing, while leaving flavor-changing neutral currents suppressed. Because the third generation quarks actually feel the walking force their masses can be much larger than those of the other quarks and the leptons. The only non-standard particles with masses below several TeV are the single doublet of technifermions, so electroweak radiative corrections are estimable and within experimental limits. The tuning of couplings is mild. C1 LAWRENCE BERKELEY LAB,BERKELEY,CA 94720. RP SUNDRUM, R (reprint author), UNIV CALIF BERKELEY,DEPT PHYS,1 CYCLOTRON RD,BERKELEY,CA 94720, USA. NR 37 TC 19 Z9 19 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 APR 26 PY 1993 VL 395 IS 1-2 BP 60 EP 76 DI 10.1016/0550-3213(93)90208-7 PG 17 WC Physics, Particles & Fields SC Physics GA LB640 UT WOS:A1993LB64000004 ER PT J AU COHN, JD PERIWAL, V AF COHN, JD PERIWAL, V TI LORENTZ INVARIANCE OF EFFECTIVE STRINGS SO NUCLEAR PHYSICS B LA English DT Article ID FIELD-THEORY; QUANTUM; EXPANSION; SYMMETRY AB Starting from a Poincare-invariant field theory of a real scalar field with interactions governed by a double-well potential in 2+1 dimensions, the Lorentz representation induced on the collective coordinates describing low-energy excitations about an effective string background is derived. In this representation, Lorentz transformations are given in terms of an infinite series, in powers of derivatives along the world-sheet. Transformations.that act on the direction transverse to the string world-sheet involve a universal dimension -1 term. As a consequence, Lorentz invariance holds in this theory of long effective strings due to cancellations in the action between irrelevant terms and the dimension-2 term that describes free massless scalar fields in two dimensions. C1 INST ADV STUDY,PRINCETON,NJ 08540. RP COHN, JD (reprint author), FERMILAB NATL ACCELERATOR LAB,MS106,POB 500,BATAVIA,IL 60510, USA. NR 18 TC 2 Z9 2 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 APR 26 PY 1993 VL 395 IS 1-2 BP 119 EP 128 DI 10.1016/0550-3213(93)90210-G PG 10 WC Physics, Particles & Fields SC Physics GA LB640 UT WOS:A1993LB64000006 ER PT J AU ADAMS, FC FATUZZO, M FREESE, K TARLE, G WATKINS, R TURNER, MS AF ADAMS, FC FATUZZO, M FREESE, K TARLE, G WATKINS, R TURNER, MS TI EXTENSION OF THE PARKER BOUND ON THE FLUX OF MAGNETIC MONOPOLES SO PHYSICAL REVIEW LETTERS LA English DT Article ID NUCLEON DECAY; NEUTRON STARS; SUPERCONDUCTIVE DETECTOR; ASTROPHYSICAL BODIES; FIELDS; GENERATION; LIMIT; CATALYSIS; SURVIVAL AB An extension of the Parker bound on the flux F of magnetic monopoles leads to a stronger bound than obtained previously. The survival and growth of a small galactic seed field requires F less-than-or-equal-to 10(-16)(m/10(17) GeV) cm-2 s-1 sr-1. This new limit rules out the possibility that monopoles much lighter than 10(17) GeV/c2 can provide the closure density of the Universe. C1 NASA,FERMILAB ASTROPHYS CTR,FERMI NATL ACCELERATOR LAB,BATAVIA,IL 60510. UNIV CHICAGO,DEPT PHYS,CHICAGO,IL 60637. UNIV CHICAGO,DEPT ASTRON & ASTROPHYS,CHICAGO,IL 60637. RP ADAMS, FC (reprint author), UNIV MICHIGAN,DEPT PHYS,ANN ARBOR,MI 48109, USA. NR 41 TC 39 Z9 39 U1 0 U2 2 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 APR 26 PY 1993 VL 70 IS 17 BP 2511 EP 2514 DI 10.1103/PhysRevLett.70.2511 PG 4 WC Physics, Multidisciplinary SC Physics GA KY503 UT WOS:A1993KY50300002 ER PT J AU ABE, K ABT, I ACTON, PD ADOLPHSEN, CE AGNEW, G ALBER, C ALZOFON, DF ANTILOGUS, P ARROYO, C ASH, WW ASHFORD, V ASTBURY, A ASTON, D AU, Y AXEN, DA BACCHETTA, N BAIRD, KG BAKER, W BALTAY, C BAND, HR BARANKO, G BARDON, O BARRERA, F BATTISTON, R BAZARKO, AO BEAN, A BEER, G BELCINSKI, RJ BELL, RA BENDAVID, R BENVENUTI, AC BERGER, R BERRIDGE, SC BETHKE, S BIASINI, M BIENZ, T BILEI, GM BIRD, F BISELLO, D BLAYLOCK, G BLUMBERG, R BOGART, JR BOLTON, T BOUGEROLLE, S BOWER, GR BOYCE, RF BRAU, JE BREIDENBACH, M BROWDER, TE BUGG, WM BURGESS, B BURKE, D BURNETT, TH BURROWS, PN BUSZA, W BYERS, BL CALCATERRA, A CALDWELL, DO CALLOWAY, D CAMANZI, B CAMILLERI, L CARPINELLI, M CARR, J CARTWRIGHT, S CASSELL, R CASTALDI, R CASTRO, A CAVALLISFORZA, M CHADWICK, GB CHAMBERLAIN, O CHAMBERS, D CHEN, L CLARKE, PEL CLAUS, R CLENDENIN, J COHN, HO COLLER, JA COOK, V CORDS, D COTTON, R COWAN, RF COYLE, PA COYNE, DG CRADDOCK, W CUTLER, H DOLIVEIRA, A DAMERELL, CJS DASU, S DAVIS, R DESANGRO, R DESIMONE, P DESIMONE, S DEAN, T DECKER, FJ DEJONGH, F DELLORSO, R DISCO, A DOLIN, R DOWNING, RW DU, YC DUBOIS, R DUBOSCQ, JE DUNWOODIE, W DURRETT, DD ECKLUND, SD EIGEN, G EISENSTEIN, BI ELIA, R EMMA, PJ EMMET, WT ENGLISH, RL ERDOS, E ESCALERA, J FAN, C FERO, MJ FERRIE, J FIEGUTH, T FLYNN, J FORBUSH, DA FORTUNE, KM FOX, JD FOX, MJ FREY, R FREYTAG, DR FRIEDMAN, JI FRISCH, J FUJIMOTO, J FURUNO, K GAILLARD, M GALLINARO, M GARWIN, E GILLMAN, T GIOUMOUSIS, A GLADDING, G GONZALEZ, S GURD, DP HALE, DL HALLER, GM HALLEWELL, GD HAMILTON, V HANEY, MJ HANSLKOZANECKA, T HARGIS, H HARRISON, J HART, EL HASEGAWA, K HASEGAWA, Y HEDGES, S HERTZBACH, SS HILDRETH, MD HILOMEN, RC HIMEL, TM HITLIN, DG HODGES, TA HODGSON, J HOEFLICH, JJ HONMA, A HORELICK, D HUBER, J HUFFER, ME HUGHES, EW HWANG, H HYATT, E IWASAKI, Y IZEN, JM JOBE, RK JACQUES, P JAKO, C JOHNSON, AS JOHNSON, JR JOHNSON, RA JONES, S JUNK, T KAISER, S KAJIKAWA, R KALELKAR, M KANG, H KARLINER, I KAWAHARA, H KEELER, RK KELSEY, MH KENDALL, HW KHARAKH, D KIM, HY KIM, PC KING, R KLEIN, M KOFLER, RR KOWITT, M KREJCIK, P KRISHNA, NM KROEGER, RS KULIKOV, AV KUNZ, PF KWON, Y LABS, JF LANGSTAFF, RR LANGSTON, M LARSEN, R LATH, A LAUBER, JA LEITH, DWG LIMBERG, T LINTERN, L LIU, X LORETI, M LU, A LYNCH, HL LYONS, T MA, J MAJID, WA MANCINELLI, G MANLY, S MANSOUR, D MANTOVANI, G MARKIEWICZ, TW MARUYAMA, T MASON, GR MASUDA, H MATHYS, L MAZAHERI, G MAZZUCATO, A MAZZUCATO, E MCCORMICK, DJ MCGOWAN, JF MCHUGH, S MCKEMEY, AK MEADOWS, BT MELLOR, DJ MESSNER, R MINCER, AI MINTY, M MOCKETT, PM MOFFEIT, KC MORRISON, RJ MOURS, B MUELLER, G MULLER, D MUNDY, G NAGAMINE, T NAUENBERG, U NEAL, H NELSON, D NESTEROV, V NORDBY, M NUSSBAUM, M NUTTALL, A OGREN, H OLSEN, J ORAM, C OSBORNE, LS OSSA, R OXOBY, G PAFFRATH, L PALOUNEK, A PANVINI, RS PARK, H PAULUZZI, M PAVEL, TJ PERRIER, F PERUZZI, I PESCARA, L PETERS, D PETERSEN, H PETRADZA, M PHINNEY, N PICCOLO, M PIEMONTESE, L PIERONI, E PITTHAN, R PITTS, KT PLANO, RJ POFFENBERGER, PR PREPOST, R PRESCOTT, CY PRIPSTEIN, D PUNKAR, GD PUTALLAZ, G RAIMONDI, P RANKIN, P RATCLIFF, BN REEVES, TW RENSING, PE RICHMAN, JD RINTA, R ROBERTSON, LP ROCHESTER, LS ROSENSON, L ROSS, MC ROTHBERG, JE ROTHENBERG, A ROWSON, PC RUSSELL, JJ RUST, D RUTZ, E SAEZ, P SANTHA, AK SANTOCCHIA, A SAXTON, OH SCHALK, T SCHENK, PR SCHINDLER, RH SCHNEEKLOTH, U SCHNEIDER, M SCHULTZ, D SCHULTZ, GE SCHUMM, BA SEEMAN, JT SEIDEN, A SERVOLI, L SETTLES, M SHAEVITZ, MH SHANK, JT SHAPIRO, G SHAPIRO, SL SHAW, H SHEPPARD, JC SHERDEN, DJ SHIMOMURA, T SHOUP, A SHYPIT, RL SIEMANN, RH SIMOPOULOS, C SKARPAAS, K SMITH, SR SNYDER, A SNYDER, JA SOBIE, R SOKOLOFF, MD SPENCE, WL SPENCER, EN STLORANT, S STAMER, P STEINER, H STEINER, R STEPHENSON, RJ STEWART, G STILES, P STOCKDALE, IE STRAUSS, MG SU, D SUEKANE, F SUGIYAMA, A SUZUKI, S SWARTZ, M SZUMILO, A TAHAR, MZ TAKAHASHI, T TANG, H TAPPERN, GJ TARNOPOLSKY, G TAYLOR, FE TECCHIO, M THALER, JJ TOEVS, F TOGE, N TURCOTTE, M TURK, JD TURNER, JL USHER, T VAVRA, J VANNINI, C VELLA, E VENUTI, JP VERDIER, R VERDINI, PG WADSWORTH, BF WAITE, AP WALKER, NJ WALZ, D WARNER, D WATT, R WATTS, SJ WEBER, T WEIDEMANN, AW WHITAKER, JS WHITE, SL WICKENS, FJ WICKERT, SA WILLIAMS, DA WILLIAMS, DC WILLIAMS, RW WILLIAMS, SH WILSON, RJ WISNIEWSKI, WJ WITHERELL, MS WOODLY, MD WOODS, M WORD, GB WYSS, J YAMAMOTO, RK YAMARTINO, JM YEE, C YEREMIAN, AD YELLIN, SJ YIM, A YOUNG, CC YOUNG, KK YUTA, H ZAPALAC, G ZDARKO, RW ZEITLIN, C ZHOU, J ZIEMANN, V ZOLOTOREV, M ZUCCHELLI, P AF ABE, K ABT, I ACTON, PD ADOLPHSEN, CE AGNEW, G ALBER, C ALZOFON, DF ANTILOGUS, P ARROYO, C ASH, WW ASHFORD, V ASTBURY, A ASTON, D AU, Y AXEN, DA BACCHETTA, N BAIRD, KG BAKER, W BALTAY, C BAND, HR BARANKO, G BARDON, O BARRERA, F BATTISTON, R BAZARKO, AO BEAN, A BEER, G BELCINSKI, RJ BELL, RA BENDAVID, R BENVENUTI, AC BERGER, R BERRIDGE, SC BETHKE, S BIASINI, M BIENZ, T BILEI, GM BIRD, F BISELLO, D BLAYLOCK, G BLUMBERG, R BOGART, JR BOLTON, T BOUGEROLLE, S BOWER, GR BOYCE, RF BRAU, JE BREIDENBACH, M BROWDER, TE BUGG, WM BURGESS, B BURKE, D BURNETT, TH BURROWS, PN BUSZA, W BYERS, BL CALCATERRA, A CALDWELL, DO CALLOWAY, D CAMANZI, B CAMILLERI, L CARPINELLI, M CARR, J CARTWRIGHT, S CASSELL, R CASTALDI, R CASTRO, A CAVALLISFORZA, M CHADWICK, GB CHAMBERLAIN, O CHAMBERS, D CHEN, L CLARKE, PEL CLAUS, R CLENDENIN, J COHN, HO COLLER, JA COOK, V CORDS, D COTTON, R COWAN, RF COYLE, PA COYNE, DG CRADDOCK, W CUTLER, H DOLIVEIRA, A DAMERELL, CJS DASU, S DAVIS, R DESANGRO, R DESIMONE, P DESIMONE, S DEAN, T DECKER, FJ DEJONGH, F DELLORSO, R DISCO, A DOLIN, R DOWNING, RW DU, YC DUBOIS, R DUBOSCQ, JE DUNWOODIE, W DURRETT, DD ECKLUND, SD EIGEN, G EISENSTEIN, BI ELIA, R EMMA, PJ EMMET, WT ENGLISH, RL ERDOS, E ESCALERA, J FAN, C FERO, MJ FERRIE, J FIEGUTH, T FLYNN, J FORBUSH, DA FORTUNE, KM FOX, JD FOX, MJ FREY, R FREYTAG, DR FRIEDMAN, JI FRISCH, J FUJIMOTO, J FURUNO, K GAILLARD, M GALLINARO, M GARWIN, E GILLMAN, T GIOUMOUSIS, A GLADDING, G GONZALEZ, S GURD, DP HALE, DL HALLER, GM HALLEWELL, GD HAMILTON, V HANEY, MJ HANSLKOZANECKA, T HARGIS, H HARRISON, J HART, EL HASEGAWA, K HASEGAWA, Y HEDGES, S HERTZBACH, SS HILDRETH, MD HILOMEN, RC HIMEL, TM HITLIN, DG HODGES, TA HODGSON, J HOEFLICH, JJ HONMA, A HORELICK, D HUBER, J HUFFER, ME HUGHES, EW HWANG, H HYATT, E IWASAKI, Y IZEN, JM JOBE, RK JACQUES, P JAKO, C JOHNSON, AS JOHNSON, JR JOHNSON, RA JONES, S JUNK, T KAISER, S KAJIKAWA, R KALELKAR, M KANG, H KARLINER, I KAWAHARA, H KEELER, RK KELSEY, MH KENDALL, HW KHARAKH, D KIM, HY KIM, PC KING, R KLEIN, M KOFLER, RR KOWITT, M KREJCIK, P KRISHNA, NM KROEGER, RS KULIKOV, AV KUNZ, PF KWON, Y LABS, JF LANGSTAFF, RR LANGSTON, M LARSEN, R LATH, A LAUBER, JA LEITH, DWG LIMBERG, T LINTERN, L LIU, X LORETI, M LU, A LYNCH, HL LYONS, T MA, J MAJID, WA MANCINELLI, G MANLY, S MANSOUR, D MANTOVANI, G MARKIEWICZ, TW MARUYAMA, T MASON, GR MASUDA, H MATHYS, L MAZAHERI, G MAZZUCATO, A MAZZUCATO, E MCCORMICK, DJ MCGOWAN, JF MCHUGH, S MCKEMEY, AK MEADOWS, BT MELLOR, DJ MESSNER, R MINCER, AI MINTY, M MOCKETT, PM MOFFEIT, KC MORRISON, RJ MOURS, B MUELLER, G MULLER, D MUNDY, G NAGAMINE, T NAUENBERG, U NEAL, H NELSON, D NESTEROV, V NORDBY, M NUSSBAUM, M NUTTALL, A OGREN, H OLSEN, J ORAM, C OSBORNE, LS OSSA, R OXOBY, G PAFFRATH, L PALOUNEK, A PANVINI, RS PARK, H PAULUZZI, M PAVEL, TJ PERRIER, F PERUZZI, I PESCARA, L PETERS, D PETERSEN, H PETRADZA, M PHINNEY, N PICCOLO, M PIEMONTESE, L PIERONI, E PITTHAN, R PITTS, KT PLANO, RJ POFFENBERGER, PR PREPOST, R PRESCOTT, CY PRIPSTEIN, D PUNKAR, GD PUTALLAZ, G RAIMONDI, P RANKIN, P RATCLIFF, BN REEVES, TW RENSING, PE RICHMAN, JD RINTA, R ROBERTSON, LP ROCHESTER, LS ROSENSON, L ROSS, MC ROTHBERG, JE ROTHENBERG, A ROWSON, PC RUSSELL, JJ RUST, D RUTZ, E SAEZ, P SANTHA, AK SANTOCCHIA, A SAXTON, OH SCHALK, T SCHENK, PR SCHINDLER, RH SCHNEEKLOTH, U SCHNEIDER, M SCHULTZ, D SCHULTZ, GE SCHUMM, BA SEEMAN, JT SEIDEN, A SERVOLI, L SETTLES, M SHAEVITZ, MH SHANK, JT SHAPIRO, G SHAPIRO, SL SHAW, H SHEPPARD, JC SHERDEN, DJ SHIMOMURA, T SHOUP, A SHYPIT, RL SIEMANN, RH SIMOPOULOS, C SKARPAAS, K SMITH, SR SNYDER, A SNYDER, JA SOBIE, R SOKOLOFF, MD SPENCE, WL SPENCER, EN STLORANT, S STAMER, P STEINER, H STEINER, R STEPHENSON, RJ STEWART, G STILES, P STOCKDALE, IE STRAUSS, MG SU, D SUEKANE, F SUGIYAMA, A SUZUKI, S SWARTZ, M SZUMILO, A TAHAR, MZ TAKAHASHI, T TANG, H TAPPERN, GJ TARNOPOLSKY, G TAYLOR, FE TECCHIO, M THALER, JJ TOEVS, F TOGE, N TURCOTTE, M TURK, JD TURNER, JL USHER, T VAVRA, J VANNINI, C VELLA, E VENUTI, JP VERDIER, R VERDINI, PG WADSWORTH, BF WAITE, AP WALKER, NJ WALZ, D WARNER, D WATT, R WATTS, SJ WEBER, T WEIDEMANN, AW WHITAKER, JS WHITE, SL WICKENS, FJ WICKERT, SA WILLIAMS, DA WILLIAMS, DC WILLIAMS, RW WILLIAMS, SH WILSON, RJ WISNIEWSKI, WJ WITHERELL, MS WOODLY, MD WOODS, M WORD, GB WYSS, J YAMAMOTO, RK YAMARTINO, JM YEE, C YEREMIAN, AD YELLIN, SJ YIM, A YOUNG, CC YOUNG, KK YUTA, H ZAPALAC, G ZDARKO, RW ZEITLIN, C ZHOU, J ZIEMANN, V ZOLOTOREV, M ZUCCHELLI, P TI 1ST MEASUREMENT OF THE LEFT-RIGHT CROSS-SECTION ASYMMETRY IN Z-BOSON PRODUCTION BY E+E- COLLISIONS SO PHYSICAL REVIEW LETTERS LA English DT Article ID POLARIZATION; DECAYS AB We present the first measurement of the left-right cross section asymmetry (A(LR)) for Z boson production by e+e- collisions. The measurement was performed at a center-of-mass energy of 91.55 GeV with the SLD detector at the SLAC Linear Collider which utilized a longitudinally polarized electron beam. The average beam polarization was (22.4 +/- 0.6)%. Using a sample of 10224 Z decays, we measure A(LR) to be 0.100 +/- 0.044(stat) +/- 0.004(syst), which determines the effective weak mixing angle to be sin2theta(W)eff=0.2378 +/- 0.0056(stat) +/- 0.0005(syst). C1 ADELPHI UNIV,GARDEN CITY,NY 11530. BOSTON UNIV,BOSTON,MA 02215. UNIV BRITISH COLUMBIA,VANCOUVER V6T 2A6,BC,CANADA. BRUNEL UNIV,UXBRIDGE UB8 3PH,MIDDX,ENGLAND. CALTECH,PASADENA,CA 91125. UNIV CALIF SANTA BARBARA,SANTA BARBARA,CA 93106. UNIV CALIF SANTA CRUZ,SANTA CRUZ,CA 95064. UNIV CINCINNATI,CINCINNATI,OH 45221. UNIV COLORADO,BOULDER,CO 80309. COLUMBIA UNIV,NEW YORK,NY 10027. UNIV FERRARA,I-44100 FERRARA,ITALY. INDIANA UNIV,BLOOMINGTON,IN 47405. UNIV ILLINOIS,URBANA,IL 61801. LAWRENCE BERKELEY LAB,BERKELEY,CA 94720. MIT,CAMBRIDGE,MA 02139. UNIV MASSACHUSETTS,AMHERST,MA 01003. NAGOYA UNIV,CHIKUSA KU,NAGOYA,AICHI 464,JAPAN. UNIV OREGON,EUGENE,OR 97403. UNIV PADUA,I-35100 PADUA,ITALY. UNIV PERUGIA,I-06100 PERUGIA,ITALY. UNIV PISA,I-56100 PISA,ITALY. RUTHERFORD APPLETON LAB,DIDCOT OX11 0QX,OXON,ENGLAND. STANFORD UNIV,STANFORD LINEAR ACCELERATOR CTR,STANFORD,CA 94305. UNIV TENNESSEE,KNOXVILLE,TN 37996. TRIUMF,VANCOUVER V6T 2A3,BC,CANADA. VANDERBILT UNIV,NASHVILLE,TN 37235. UNIV WASHINGTON,SEATTLE,WA 98195. UNIV WISCONSIN,MADISON,WI 53706. INFN,SEZ BOLOGNA,I-40126 BOLOGNA,ITALY. INFN,SEZ FERRARA,I-44100 FERRARA,ITALY. INFN,LAB NAZL FRASCATI,I-00044 FRASCATI,ITALY. KEK,NATL LAB,TSUKUBA,IBARAKI 305,JAPAN. INFN,SEZ PADOVA,I-35100 PADUA,ITALY. INFN,SEZ PERUGIA,I-06100 PERUGIA,ITALY. INFN,SEZ PISA,I-56100 PISA,ITALY. RUTGERS STATE UNIV,PISCATAWAY,NJ 08855. UNIV VICTORIA,TRIUMF,VICTORIA V8W 3P6,BC,CANADA. YALE UNIV,NEW HAVEN,CT 06511. UNIV GENOA,I-16126 GENOA,ITALY. RP ABE, K (reprint author), TOHOKU UNIV,SENDAI,MIYAGI 980,JAPAN. RI Servoli, Leonello/E-6766-2012; de Sangro, Riccardo/J-2901-2012; de Simone, Patrizia/J-3549-2012; Perrier, Frederic/A-5953-2011; Cavalli-Sforza, Matteo/H-7102-2015; Calcaterra, Alessandro/P-5260-2015; Frey, Raymond/E-2830-2016; OI Servoli, Leonello/0000-0003-1725-9185; de Sangro, Riccardo/0000-0002-3808-5455; Calcaterra, Alessandro/0000-0003-2670-4826; Frey, Raymond/0000-0003-0341-2636; Wyss, Jeffery/0000-0002-8277-4012; Wilson, Robert/0000-0002-8184-4103; Gallinaro, Michele/0000-0003-1261-2277 NR 28 TC 56 Z9 56 U1 0 U2 6 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 APR 26 PY 1993 VL 70 IS 17 BP 2515 EP 2520 DI 10.1103/PhysRevLett.70.2515 PG 6 WC Physics, Multidisciplinary SC Physics GA KY503 UT WOS:A1993KY50300003 ER PT J AU ATIYA, MS CHIANG, IH FRANK, JS HAGGERTY, JS ITO, MM KYCIA, TF LI, KK LITTENBERG, LS SAMBAMURTI, A STEVENS, A STRAND, RC LOUIS, WC AKERIB, DS MARLOW, DR MEYERS, PD SELEN, MA SHOEMAKER, FC SMITH, AJS BLACKMORE, EW BRYMAN, DA FELAWKA, L KITCHING, P KONAKA, A KUNO, Y MACDONALD, JA NUMAO, T PADLEY, P POUTISSOU, JM POUTISSOU, R ROY, J SOLUK, R TURCOT, AS AF ATIYA, MS CHIANG, IH FRANK, JS HAGGERTY, JS ITO, MM KYCIA, TF LI, KK LITTENBERG, LS SAMBAMURTI, A STEVENS, A STRAND, RC LOUIS, WC AKERIB, DS MARLOW, DR MEYERS, PD SELEN, MA SHOEMAKER, FC SMITH, AJS BLACKMORE, EW BRYMAN, DA FELAWKA, L KITCHING, P KONAKA, A KUNO, Y MACDONALD, JA NUMAO, T PADLEY, P POUTISSOU, JM POUTISSOU, R ROY, J SOLUK, R TURCOT, AS TI SEARCH FOR THE DECAY K+-]PI+NU(NU)OVER-BAR SO PHYSICAL REVIEW LETTERS LA English DT Article ID RARE KAON DECAYS; CONSTRAINTS; SYMMETRY AB An upper limit on the branching ratio for the decay K+ --> pi+nunuBAR is set at 7.5 x 10(-9) (90% C.L.) using the kinematic region above the K(pi2) (K+ --> pi+pi0) peak. When combined with our result from below the K(pi2) peak, we obtain the limit 5.2 x 10(-9). An upper limit of 1.7 x 10(-9) is also found on the branching ratio for decays of the form K+ --> pi+X0 where X0 is any massless, weakly interacting neutral particle. Limits are also set for cases where M(X0) > 0. C1 LOS ALAMOS NATL LAB,DIV MEDIUM ENERGY PHYS,LOS ALAMOS,NM 87545. PRINCETON UNIV,JOSEPH HENRY LABS,PRINCETON,NJ 08544. TRIUMF,VANCOUVER V6T 2A3,BC,CANADA. RP ATIYA, MS (reprint author), BROOKHAVEN NATL LAB,UPTON,NY 11973, USA. RI Marlow, Daniel/C-9132-2014 NR 16 TC 24 Z9 24 U1 0 U2 0 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 APR 26 PY 1993 VL 70 IS 17 BP 2521 EP 2524 DI 10.1103/PhysRevLett.70.2521 PG 4 WC Physics, Multidisciplinary SC Physics GA KY503 UT WOS:A1993KY50300004 ER PT J AU RAMBERG, EJ BOCK, GJ COLEMAN, R ENAGONIO, J HSIUNG, YB STANFIELD, K TSCHIRHART, R YAMANAKA, T BARKER, A BRIERE, RA GIBBONS, LK MAKOFF, G PAPADIMITRIOU, V PATTERSON, JR SOMALWAR, S WAH, YW WINSTEIN, B WINSTON, R WOODS, M YAMAMOTO, H SWALLOW, EC BLAIR, G GOLLIN, GD KARLSSON, M OKAMITSU, JK DEBU, P PEYAUD, B TURLAY, R VALLAGE, B AF RAMBERG, EJ BOCK, GJ COLEMAN, R ENAGONIO, J HSIUNG, YB STANFIELD, K TSCHIRHART, R YAMANAKA, T BARKER, A BRIERE, RA GIBBONS, LK MAKOFF, G PAPADIMITRIOU, V PATTERSON, JR SOMALWAR, S WAH, YW WINSTEIN, B WINSTON, R WOODS, M YAMAMOTO, H SWALLOW, EC BLAIR, G GOLLIN, GD KARLSSON, M OKAMITSU, JK DEBU, P PEYAUD, B TURLAY, R VALLAGE, B TI SIMULTANEOUS MEASUREMENT OF K(S) AND K(L) DECAYS INTO PI+PI-GAMMA SO PHYSICAL REVIEW LETTERS LA English DT Article AB With the E731 apparatus at Fermilab, we have simultaneously collected 6859 K(L) and K(S) decays into pi+pi-gamma. Using our sample of over 370000 pi+pi- decays for normalization we have determined that the ratio GAMMA(K0 --> pi+pi-gamma)/GAMMA(K0 --> pi+pi-) is (23.0 +/- 0.7) x 10(-3) for K(L) and (7.10 +/- 0.22) x 10(-3) for K(S), for photon energies greater than 20 MeV in the kaon center of mass. After removing the inner-bremsstrahlung contribution, we find that the photon energy spectrum of the direct emission decay of the K(L) is consistent with the presence of a vector meson propagator in the form factor. C1 UNIV CHICAGO,ENRICO FERMI INST,CHICAGO,IL 60637. UNIV CHICAGO,DEPT PHYS,CHICAGO,IL 60637. ELMHURST COLL,DEPT PHYS,ELMHURST,IL 60126. PRINCETON UNIV,DEPT PHYS,PRINCETON,NJ 08544. CENS,DEPT PHYS PARTICULES ELEMENTAIRES,F-91191 GIF SUR YVETTE,FRANCE. RP RAMBERG, EJ (reprint author), FERMILAB NATL ACCELERATOR LAB,BATAVIA,IL 60510, USA. RI Briere, Roy/N-7819-2014 OI Briere, Roy/0000-0001-5229-1039 NR 12 TC 52 Z9 52 U1 0 U2 0 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 APR 26 PY 1993 VL 70 IS 17 BP 2525 EP 2528 DI 10.1103/PhysRevLett.70.2525 PG 4 WC Physics, Multidisciplinary SC Physics GA KY503 UT WOS:A1993KY50300005 ER PT J AU RAMBERG, EJ BOCK, GJ COLEMAN, R ENAGONIO, J HSIUNG, YB STANFIELD, K TSCHIRHART, R YAMANAKA, T BARKER, AR BRIERE, RA GIBBONS, LK MAKOFF, G PAPADIMITRIOU, V PATTERSON, JR SOMALWAR, S WAH, YW WINSTEIN, B WINSTON, R WOODS, M YAMAMOTO, H SWALLOW, EC BLAIR, G GOLLIN, GD KARLSSON, M OKAMITSU, JK DEBU, P PEYAUD, B TURLAY, R VALLAGE, B AF RAMBERG, EJ BOCK, GJ COLEMAN, R ENAGONIO, J HSIUNG, YB STANFIELD, K TSCHIRHART, R YAMANAKA, T BARKER, AR BRIERE, RA GIBBONS, LK MAKOFF, G PAPADIMITRIOU, V PATTERSON, JR SOMALWAR, S WAH, YW WINSTEIN, B WINSTON, R WOODS, M YAMAMOTO, H SWALLOW, EC BLAIR, G GOLLIN, GD KARLSSON, M OKAMITSU, JK DEBU, P PEYAUD, B TURLAY, R VALLAGE, B TI MEASUREMENT OF THE CP-VIOLATION PARAMETER ETA+-GAMMA IN NEUTRAL KAON DECAYS SO PHYSICAL REVIEW LETTERS LA English DT Article ID 1ST AB Interference between K(S) and K(L) decays into the final state pi+pi-gamma has been observed in experiment 731 at Fermilab. By fitting the distribution of decays downstream of a regenerator, a new CP-violation parameter eta+-gamma, analogous to eta+-, has been measured, with its magnitude equal to (2.15 +/- 0.26 +/- 0.20) x 10(-3), and phi+-gamma, the associated phase angle, equal to (72 +/- 23 +/- 17)degrees. Assuming that any difference between this fit value for eta+-, and the previously measured value for eta+- can be attributed to direct CP violation in this decay, a limit of \epsilon'+-gamma\/epsilon < 0.3 at the 90% confidence level has been made. C1 UNIV CHICAGO,ENRICO FERMI INST,CHICAGO,IL 60637. UNIV CHICAGO,DEPT PHYS,CHICAGO,IL 60637. ELMHURST COLL,DEPT PHYS,ELMHURST,IL 60126. CENS,DEPT PHYS PARTICULES ELEMENTAIRES,F-91191 GIF SUR YVETTE,FRANCE. PRINCETON UNIV,DEPT PHYS,PRINCETON,NJ 08544. RP RAMBERG, EJ (reprint author), FERMILAB NATL ACCELERATOR LAB,BATAVIA,IL 60510, USA. RI Briere, Roy/N-7819-2014 OI Briere, Roy/0000-0001-5229-1039 NR 13 TC 20 Z9 20 U1 0 U2 0 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 APR 26 PY 1993 VL 70 IS 17 BP 2529 EP 2532 DI 10.1103/PhysRevLett.70.2529 PG 4 WC Physics, Multidisciplinary SC Physics GA KY503 UT WOS:A1993KY50300006 ER PT J AU WARD, BFL AF WARD, BFL TI RELATIVE SIZE OF SU(3) SYMMETRY-BREAKING EFFECTS AND PENGUIN DIAGRAMS SO PHYSICAL REVIEW LETTERS LA English DT Article ID ISOSPIN ANALYSIS; 2-BODY DECAYS; MESONS; SCHEME AB We use the data on the decays D --> pipi and D --> KK as a test vehicle for evaluating the effects of penguin diagrams in exclusive heavy meson decays. Evaluating GAMMA(D --> pi+pi-) and GAMMA(D --> K+K-), we find good agreement between our theoretical SU(2L) x U(1) x SU(3)c-based predictions and observation. Contributions from penguin diagrams are small and SU(3) flavor breaking effects account for the large value of GAMMA(D --> K+K-)/GAMMA(D --> pi+pi-). Implications for B decays are discussed briefly. C1 STANFORD LINEAR ACCELERATOR CTR,STANFORD,CA 94309. CERN,TH DIV,GENEVA 23,SWITZERLAND. RP WARD, BFL (reprint author), UNIV TENNESSEE,DEPT PHYS & ASTRON,KNOXVILLE,TN 37996, USA. NR 22 TC 8 Z9 8 U1 0 U2 0 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 APR 26 PY 1993 VL 70 IS 17 BP 2533 EP 2536 DI 10.1103/PhysRevLett.70.2533 PG 4 WC Physics, Multidisciplinary SC Physics GA KY503 UT WOS:A1993KY50300007 ER PT J AU PIEPER, SC PANDHARIPANDE, VR AF PIEPER, SC PANDHARIPANDE, VR TI ORIGINS OF SPIN-ORBIT-SPLITTING IN N-15 SO PHYSICAL REVIEW LETTERS LA English DT Article ID SHELL-MODEL; NUCLEI; STATE AB The spin-orbit splitting of the p1/2 and p3/2 hole states in N-15 is studied with realistic nuclear forces and the variational cluster Monte Carlo method. The results show that the two-nucleon L.S forces give approximately half of the observed splitting, while the other half comes from pion exchange interactions between three or more nucleons. The observed splitting is fairly well reproduced by these calculations based on nonrelativistic nuclear many-body theory. C1 UNIV ILLINOIS,DEPT PHYS,URBANA,IL 61801. RP PIEPER, SC (reprint author), ARGONNE NATL LAB,DIV PHYS,ARGONNE,IL 60439, USA. NR 19 TC 53 Z9 53 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 APR 26 PY 1993 VL 70 IS 17 BP 2541 EP 2544 DI 10.1103/PhysRevLett.70.2541 PG 4 WC Physics, Multidisciplinary SC Physics GA KY503 UT WOS:A1993KY50300009 ER PT J AU BAIOD, R CHU, CM COURANT, ED DERBENEV, YS DURYEA, J KOULSHA, AV KRISCH, AD MINTY, MG NURUSHEV, TS PHELPS, RA SHOUMKIN, DS WONG, VK CAUSSYN, DD LEE, SY RINCKEL, T SPERISEN, F STEPHENSON, EJ VONPRZEWOSKI, B OHMORI, C PANCELLA, PV RATNER, LG WIENANDS, U AF BAIOD, R CHU, CM COURANT, ED DERBENEV, YS DURYEA, J KOULSHA, AV KRISCH, AD MINTY, MG NURUSHEV, TS PHELPS, RA SHOUMKIN, DS WONG, VK CAUSSYN, DD LEE, SY RINCKEL, T SPERISEN, F STEPHENSON, EJ VONPRZEWOSKI, B OHMORI, C PANCELLA, PV RATNER, LG WIENANDS, U TI A SIBERIAN SNAKE WITH OVERLAPPING DEPOLARIZING RESONANCES SO PHYSICAL REVIEW LETTERS LA English DT Article ID ACCELERATION; ENERGY; SHIFT AB The behavior of ''overlapping'' depolarizing resonances was studied using a stored 106.4-MeV polarized proton beam. We used an rf solenoid magnet to create an ''rf induced'' depolarizing resonance which was then forced to overlap with the Ggamma = 2 imperfection depolarizing resonance. We found significant interactions between the two resonances by varying their frequencies and strengths; the frequency of the rf resonance strongly affected the response of the imperfection resonance to correction magnetic fields. The Siberian snake overcame all observable depolarization due to the overlapping resonances and maintained full polarization for all observed frequencies and strengths. C1 UNIV MICHIGAN,RANDALL LAB PHYS,ANN ARBOR,MI 48109. INDIANA UNIV,CYCLOTRON FACIL,BLOOMINGTON,IN 47408. MOSCOW MV LOMONOSOV STATE UNIV,MOSCOW,RUSSIA. WESTERN MICHIGAN UNIV,DEPT PHYS,KALAMAZOO,MI 49008. BROOKHAVEN NATL LAB,AGS DEPT,UPTON,NY 11973. LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545. TRIUMF,VANCOUVER V6T 2A3,BC,CANADA. UNIV TOKYO,TOKYO 113,JAPAN. NR 14 TC 17 Z9 17 U1 0 U2 0 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 APR 26 PY 1993 VL 70 IS 17 BP 2557 EP 2560 DI 10.1103/PhysRevLett.70.2557 PG 4 WC Physics, Multidisciplinary SC Physics GA KY503 UT WOS:A1993KY50300013 ER PT J AU BEZZERIDES, B DUBOIS, DF ROSE, HA AF BEZZERIDES, B DUBOIS, DF ROSE, HA TI SATURATION OF STIMULATED RAMAN-SCATTERING BY THE EXCITATION OF STRONG LANGMUIR TURBULENCE SO PHYSICAL REVIEW LETTERS LA English DT Article ID LASER-PRODUCED PLASMAS; BRILLOUIN-SCATTERING; DECAY AB Numerical studies of a model of stimulated Raman scattering (SRS) coupled to Langmuir turbulence show that once the collisional threshold is exceeded for parametric decay of the SRS daughter Langmuir wave the noncollisional dissipation resulting from Langmuir collapse can strongly saturate the Langmuir wave and the resulting SRS reflectivity. The model provides information on the total rate of hot electron generation. Scaling laws for the reflectivity as a function of laser and plasma parameters are found. RP BEZZERIDES, B (reprint author), LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545, USA. NR 19 TC 60 Z9 60 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 APR 26 PY 1993 VL 70 IS 17 BP 2569 EP 2572 DI 10.1103/PhysRevLett.70.2569 PG 4 WC Physics, Multidisciplinary SC Physics GA KY503 UT WOS:A1993KY50300016 ER PT J AU YOUNG, FC HINSHELWOOD, DD HUBBARD, RF LAMPE, M NERI, JM OLSON, CL OTTINGER, PF ROSE, DV SLINKER, SP STEPHANAKIS, SJ WELCH, DR AF YOUNG, FC HINSHELWOOD, DD HUBBARD, RF LAMPE, M NERI, JM OLSON, CL OTTINGER, PF ROSE, DV SLINKER, SP STEPHANAKIS, SJ WELCH, DR TI CURRENT NEUTRALIZATION OF INTENSE MEV PROTON-BEAMS TRANSPORTED IN LOW-PRESSURE GAS SO PHYSICAL REVIEW LETTERS LA English DT Article ID ION-BEAMS AB This paper reports on the first experiments designed to study ion-beam-induced gas ionization and subsequent conductivity growth using intense proton beams transported through various gases in the 1-Torr pressure regime. Net-current fractions of 2% to 8% are measured outside the beam channel. Ionization is confined predominantly to the beam channel with ionization fractions of a few percent. Analysis suggests that net currents are larger inside the beam channel and that fast electrons and their secondaries carry a significant fraction of the return current in a halo outside the beam. C1 JAYCOR INC,VIENNA,VA 22182. MISSION RES CORP,ALBUQUERQUE,NM 87106. SANDIA NATL LABS,ALBUQUERQUE,NM 87185. RP YOUNG, FC (reprint author), USN,RES LAB,DIV PLASMA PHYS,WASHINGTON,DC 20375, USA. NR 18 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 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD APR 26 PY 1993 VL 70 IS 17 BP 2573 EP 2576 DI 10.1103/PhysRevLett.70.2573 PG 4 WC Physics, Multidisciplinary SC Physics GA KY503 UT WOS:A1993KY50300017 ER PT J AU BEDROSSIAN, P KAXIRAS, E AF BEDROSSIAN, P KAXIRAS, E TI SYMMETRY AND STABILITY OF SOLITARY DIMER ROWS ON SI(100) SO PHYSICAL REVIEW LETTERS LA English DT Article ID SCANNING TUNNELING MICROSCOPY; MOLECULAR-BEAM EPITAXY; SURFACES; SI(001); GROWTH; SILICON AB Metastable, monolayer-high structures as narrow as one dimer row and as long as the substrate's terrace width decorate antiphase boundaries on Si(100) following 225 eV Xe bombardment. On the basis of tunneling microscope observations and first-principles calculations, we propose that the bonding topology of a buckled dimer row on an antiphase boundary is responsible for the metastability of this ''zipper'' structure, and in turn for the preferential nucleation of dimer rows on antiphase boundaries during growth. C1 HARVARD UNIV,DEPT PHYS,CAMBRIDGE,MA 02138. HARVARD UNIV,DIV APPL SCI,CAMBRIDGE,MA 02138. RP BEDROSSIAN, P (reprint author), LAWRENCE LIVERMORE NATL LAB,POB 808,L-350,LIVERMORE,CA 94550, USA. NR 24 TC 28 Z9 28 U1 0 U2 2 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 APR 26 PY 1993 VL 70 IS 17 BP 2589 EP 2592 DI 10.1103/PhysRevLett.70.2589 PG 4 WC Physics, Multidisciplinary SC Physics GA KY503 UT WOS:A1993KY50300021 ER PT J AU LEVY, J SHERWIN, MS THEILER, J AF LEVY, J SHERWIN, MS THEILER, J TI TIME-DOMAIN STUDY OF LOW-DIMENSIONAL CHAOS IN THE SWITCHING CHARGE-DENSITY-WAVE CONDUCTOR NBSE3 SO PHYSICAL REVIEW LETTERS LA English DT Article ID MODE-LOCKING; TRANSPORT; INTERFERENCE; DYNAMICS AB We study the dynamics of switching charge-density waves (CDWs) in the presence of combined dc and ac electric fields. Analysis of the time series provides Lyapunov exponents, and an estimate for the number of active degrees of freedom. The dynamics are both low dimensional and chaotic. The principal nonlinearity which gives rise to the chaos in switching CDWs is shown to be the hysteresis in the depinning transition, rather than the interaction between two frequencies. C1 UNIV CALIF SANTA BARBARA,CTR NONLINEAR SCI,SANTA BARBARA,CA 93106. LOS ALAMOS NATL LAB,CTR NONLINEAR STUDIES,LOS ALAMOS,NM 87545. LOS ALAMOS NATL LAB,DIV THEORET,LOS ALAMOS,NM 87545. RP LEVY, J (reprint author), UNIV CALIF SANTA BARBARA,DEPT PHYS,SANTA BARBARA,CA 93106, USA. RI Levy, Jeremy/A-2081-2009 OI Levy, Jeremy/0000-0002-5700-2977 NR 19 TC 4 Z9 4 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 APR 26 PY 1993 VL 70 IS 17 BP 2597 EP 2600 DI 10.1103/PhysRevLett.70.2597 PG 4 WC Physics, Multidisciplinary SC Physics GA KY503 UT WOS:A1993KY50300023 ER PT J AU DUPUIS, N MONTAMBAUX, G DEMELO, CARS AF DUPUIS, N MONTAMBAUX, G DEMELO, CARS TI QUASI-ONE-DIMENSIONAL SUPERCONDUCTORS IN STRONG MAGNETIC-FIELD SO PHYSICAL REVIEW LETTERS LA English DT Article AB We determine the phase diagram of a quasi-one-dimensional superconductor (weakly coupled chains system with an open Fermi surface) in a magnetic field. The usual Ginzburg-Landau regime is followed, when the field is increased, by a cascade of superconducting phases separated by first-order transitions, which ends in a strong reentrance of the superconducting phase. These new phases show a novel kind of symmetry of a laminar type. The Zeeman splitting does not completely suppress the reentrance in very strong field, the ground state being in this case a Larkin-Ovchinnikov-Fulde-Ferrell state. C1 ARGONNE NATL LAB,SCI & TECHNOL CTR SUPERCONDUCTIV,DIV MAT SCI,ARGONNE,IL 60439. RP DUPUIS, N (reprint author), UNIV PARIS 11,PHYS SOLIDES LAB,F-91405 ORSAY,FRANCE. NR 15 TC 129 Z9 129 U1 1 U2 12 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 APR 26 PY 1993 VL 70 IS 17 BP 2613 EP 2616 DI 10.1103/PhysRevLett.70.2613 PG 4 WC Physics, Multidisciplinary SC Physics GA KY503 UT WOS:A1993KY50300027 ER PT J AU YAMAZAKI, A YAMAZAKI, M TSUBOI, S KISHIGAMI, A UMBARGER, KO HUTSON, LD MADLAND, WT HAYASHI, F AF YAMAZAKI, A YAMAZAKI, M TSUBOI, S KISHIGAMI, A UMBARGER, KO HUTSON, LD MADLAND, WT HAYASHI, F TI REGULATION OF G-PROTEIN FUNCTION BY AN EFFECTOR IN GTP-DEPENDENT SIGNAL TRANSDUCTION - AN INHIBITORY SUBUNIT OF CGMP PHOSPHODIESTERASE INHIBITS GTP HYDROLYSIS BY TRANSDUCIN IN VERTEBRATE ROD PHOTORECEPTORS SO JOURNAL OF BIOLOGICAL CHEMISTRY LA English DT Article ID BINDING PROTEIN; OUTER SEGMENTS; MOLECULAR MECHANISM; VISUAL EXCITATION; MEMBRANES; SITES AB The regulation of cGMP phosphodiesterase in vertebrate rod photoreceptors is a typical G protein-dependent signal transduction mechanism. The interaction of Pgamma, an inhibitory subunit of cGMP phosphodiesterase, with transducin alpha subunit (Talpha) is essential for the activation of cGMP phosphodiesterase. It has been shown that, in a homogenized preparation of frog (Rana catesbiana) rods, Pgamma interacts with GTP.Talpha and remains tightly bound to GDP.Talpha after GTP hydrolysis on Talpha. Association of this complex with betagamma subunits of transducin (Tbetagamma) triggers the release of Pgamma from the complex and the subsequent inactivation of cGMP phosphodiesterase. In a system reconstituted with purified components, both GTP- and GDP-bound forms of Talpha were found to interact with Pgamma. Under these conditions, Pgamma inhibited GTP hydrolysis by transducin in a noncompetitive manner with a K(i) of 92 nm. Binding of an hydrolysis-resistant GTP analog to Talpha was also inhibited by Pgamma. These inhibitions of transducin function were resulted from the inhibition of both hydrolysis of GTP bound to Talpha and interaction of GDP.Talpha with membrane-bound Tbetagamma. However, after GDP.Talpha reassociated with membrane-bound Tbetagamma, the inhibitory effect of Pgamma on the binding of an hydrolysis-resistant GTP analog to Talpha was greatly diminished, suggesting that the GTP/GDP exchange on Talpha was not inhibited by Pgamma. These data indicate that the Talpha function is altered during complexing with Pgamma. G protein functions may be modified by interacting with an effector in the G protein-dependent signal transduction. C1 WAYNE STATE UNIV,SCH MED,DEPT OPHTHALMOL,DETROIT,MI 48201. WAYNE STATE UNIV,SCH MED,DEPT PHARMACOL,DETROIT,MI 48201. LOS ALAMOS NATL LAB,DIV LIFE SCI,LOS ALAMOS,NM 87545. RP YAMAZAKI, A (reprint author), WAYNE STATE UNIV,SCH MED,KRESGE EYE INST,4717 ST ANTOINE ST,DETROIT,MI 48201, USA. FU NEI NIH HHS [EY07546, EY09631] NR 33 TC 29 Z9 29 U1 0 U2 1 PU AMER SOC BIOCHEMISTRY MOLECULAR BIOLOGY INC PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814 SN 0021-9258 J9 J BIOL CHEM JI J. Biol. Chem. PD APR 25 PY 1993 VL 268 IS 12 BP 8899 EP 8907 PG 9 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA KX811 UT WOS:A1993KX81100077 PM 8386172 ER PT J AU CURTISS, LA SCHOLZ, G AF CURTISS, LA SCHOLZ, G TI THE VAPOR-PHASE COMPLEX HF-ALF3 - A NEW ABINITIO MOLECULAR-ORBITAL STUDY SO CHEMICAL PHYSICS LETTERS LA English DT Article ID OCCUPATION NUMBERS; BASIS-SETS; ENERGIES; 1ST-ROW; ATOMS AB The HF-AlF3 complex is found to have a C(s) structure with an F-Al bond distance of about 1.99 angstrom and the hydrogen interacting with one of the fluorines of AlF3 in a cyclic arrangement based on ab initio molecular orbital calculations at the MP2 level. The HF subunit has a low barrier to rotation (5 kJ/mol) about the AlF3 subunit and the dissociation energy (D(e)(HF-AlF3)) is 67.0 kJ/mol from G2 (MP2) theory. C1 CTR INORGAN POLYMERS,O-1199 BERLIN,GERMANY. RP CURTISS, LA (reprint author), ARGONNE NATL LAB,9700 S CASS AVE,ARGONNE,IL 60439, USA. NR 20 TC 10 Z9 10 U1 0 U2 0 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 APR 23 PY 1993 VL 205 IS 6 BP 550 EP 554 DI 10.1016/0009-2614(93)80011-D PG 5 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA KY292 UT WOS:A1993KY29200011 ER PT J AU BOUSSIE, TR STREITWIESER, A AF BOUSSIE, TR STREITWIESER, A TI 2-COMPLEMENTARY SYNTHESES OF SYMMETRICALLY-TETRASUBSTITUTED CYCLOOCTATETRAENES SO JOURNAL OF ORGANIC CHEMISTRY LA English DT Article ID HOMOGENEOUS CATALYSIS; CONTROLLING LIGANDS; DIAZADIENES; CYCLOTETRAMERIZATION AB Two complementary synthetic approaches to tetrasubstituted cyclooctatetraenes (COT's) have been developed. The first approach involves reaction of terminal acetylenes with AlBr3 and Et3N to generate mixtures of 1,3,5,7- and 1,2,5,6-substituted syn-tricyclo[4.2 .0.02,5]octadienes (TCOD's) in satisfactory yield. These TCOD's can then be thermally or photolytically ring opened to 1,3,5,7- and 1,2,5,6-substituted COT's. Bulky substituents (e.g., tert-butyl, isopropyl) give exclusively 1,3,5,7-substituted TCOD and COT products. In the second approach, 1,3,5,7- (5) and 1,2,5,6-tetrakis-(hydroxymethyl)COT's (6) were generated and isolated in good yield from the Ni(0)-catalyzed tetramerization of propargyl alcohol. These isomers were converted to their corresponding tetrakis-(bromomethyl)COT's 8 and 9. Reduction of 8 and 9 with LiAlH4 afforded 1,3,5,7-tetramethylCOT (10) and 1,2,5,6-tetramethylCOT (11). C1 UNIV CALIF BERKELEY,DEPT CHEM,BERKELEY,CA 94720. LAWRENCE BERKELEY LAB,BERKELEY,CA 94720. NR 24 TC 22 Z9 22 U1 0 U2 0 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 APR 23 PY 1993 VL 58 IS 9 BP 2377 EP 2380 DI 10.1021/jo00061a007 PG 4 WC Chemistry, Organic SC Chemistry GA KY821 UT WOS:A1993KY82100007 ER PT J AU BURKHARTSCHULTZ, K THOMAS, CB THOMPSON, CL STROUT, CL BRINSON, E JONES, IM AF BURKHARTSCHULTZ, K THOMAS, CB THOMPSON, CL STROUT, CL BRINSON, E JONES, IM TI CHARACTERIZATION OF INVIVO SOMATIC MUTATIONS AT THE HYPOXANTHINE PHOSPHORIBOSYLTRANSFERASE GENE OF A HUMAN CONTROL POPULATION SO ENVIRONMENTAL HEALTH PERSPECTIVES LA English DT Article DE HYPRT; LYMPHOCYTES; MUTATION SPECTRUM; SOMATIC MUTATION ID HUMAN LYMPHOCYTES-T; LESCH-NYHAN SYNDROME; GUANINE PHOSPHORIBOSYLTRANSFERASE; SEQUENCE-ANALYSIS; MUTANT FREQUENCY; CLONING ASSAY; CELL CLONING; HPRT GENE; CDNA; DELETIONS AB The ability to recognize a change in mutation spectrum after an exposure to a toxic substance and then relate that exposure to health risk depends on the knowledge of mutations that occur in the absence of exposure. Toward this end, we have been studying both the frequency and molecular nature of mutations of the hypoxanthine phosphoribosyltransferase (hprt) gene in peripheral blood lymphocytes as surrogate reporters of genetic damage. We have analyzed mutants, one per donor to ensure independence, from a control population in which the quantitative effects of smoking and age on mutant frequency have been well defined. Analyses of cDNA and genomic DNA by polymerase chain reaction and sequencing have identified the mutations in 63 mutants, 45 from males and 18 from females, of which 34 were smokers and 29 were nonsmokers. Slightly less than half of the mutations were base substitutions (28); they were predominantly at GC base pairs (19). Different mutations at the same site indicated that there are features of the hprt polypeptide that affect the mutation spectrum. Two pairs of identical mutations indicated that there may also bc hot spots. Mutations not previously reported have been detected, indicating that the mutation spectrum is only partly defined. The remainder of the mutations were deletions (32) or insertions/duplications (3); deletions ranged from one base pair to complete loss of the locus. Despite a small average increase in mutant frequency for smokers, an increased proportion of base substitutions at AT base pairs in smokers (p = 0.2) hinted at a smoking-associated shift in the mutation spectrum. Expansion of the study to include individuals with larger, smoking-associated increases of mutant frequency will determine the significance of this observation. This background mutation study provides insight into factors that determine the mutation spectra of the hprt locus and provides data for comparison with mutation spectra of other populations. C1 LAWRENCE LIVERMORE NATL LAB,BIOL & BIOTECHNOL PROGRAM,L-452,POB 808,LIVERMORE,CA 94551. NIEHS,DIV BIOMETRY & RISK ASSESSMENT,RES TRIANGLE PK,NC 27709. FU NIEHS NIH HHS [N1EHS Y01-ES-80171] NR 45 TC 25 Z9 25 U1 0 U2 0 PU NATL INST ENVIRON HEALTH SCI PI RES TRIANGLE PK PA PO BOX 12233, RES TRIANGLE PK, NC 27709 SN 0091-6765 J9 ENVIRON HEALTH PERSP JI Environ. Health Perspect. PD APR 22 PY 1993 VL 101 IS 1 BP 68 EP 74 DI 10.2307/3431574 PG 7 WC Environmental Sciences; Public, Environmental & Occupational Health; Toxicology SC Environmental Sciences & Ecology; Public, Environmental & Occupational Health; Toxicology GA LD794 UT WOS:A1993LD79400024 PM 8513767 ER PT J AU CURTISS, LA NALEWAY, CA MILLER, JR AF CURTISS, LA NALEWAY, CA MILLER, JR TI THEORETICAL-STUDY OF LONG-DISTANCE ELECTRONIC COUPLING IN H2C(CH2)N-2CH2 CHAINS, N = 3-16 SO JOURNAL OF PHYSICAL CHEMISTRY LA English DT Article ID RADICAL-ANIONS AB The long-range electronic coupling in model chain alkyls H2C(CH2)n-2CH2, n = 3-16, and 1,4-dimethylenecyclohexane has been investigated using ab initio molecular orbital theory to assess dependence of the results on basis set and method of calculation. Both anion and cation pi couplings were examined. Basis sets ranging from minimal STO-3G to triple-zeta plus polarization were used, and diffuse orbitals were added to some of the basis sets. Small basis sets such as the split-valence 3-21G generally gave results in reasonable agreement with the larger basis sets. Couplings were calculated from differences in Hartree-Fock energies or from lower level ''Koopmans' theorem'' approximations based on orbital energies of the dianion, anion, neutral triplet diradical, monocation, and dication of the donor-acceptor molecules. The distance dependence is found in some cases to vary significantly with method of calculation, especially at distances greater than 7 angstrom. In most cases the distance dependence was not purely exponential. Small basis sets performed very poorly in calculating long-range direct (''through-space'') interactions but showed dramatic improvement when augmented by ''ghost'' basis functions located between the interacting groups. Agreement between the 3-21G (+ghost) results and those from larger basis sets provides evidence that direct, through-space interactions are reliably calculated. The direct interactions decrease much more rapidly with distance (beta almost-equal-to 3.0 angstrom-1) than the couplings for the chain alkyls (beta < 1 angstrom-1), demonstrating the importance of superexchange via through-bond interactions. We speculate that the reason that a small basis set such as 3-21G generally does well in the calculation of long-distance couplings in molecules is that basis functions (ghost orbitals) on the intermediate atoms assist in computation of superexchange interactions even when the intermediate atoms themselves are not involved. Finally, electronic couplings in 1,3-dimethylenecyclohexane, 1,4-dimethylenecyclohexane, and 2,6-dimethylenedecalin are calculated and compared with experiments on molecules with the same spacer groups. RP CURTISS, LA (reprint author), ARGONNE NATL LAB,ARGONNE,IL 60439, USA. NR 21 TC 94 Z9 95 U1 1 U2 4 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0022-3654 J9 J PHYS CHEM-US JI J. Phys. Chem. PD APR 22 PY 1993 VL 97 IS 16 BP 4050 EP 4058 DI 10.1021/j100118a600 PG 9 WC Chemistry, Physical SC Chemistry GA KY466 UT WOS:A1993KY46600021 ER PT J AU BARTELS, DM MEZYK, SP AF BARTELS, DM MEZYK, SP TI EPR MEASUREMENT OF THE REACTION OF ATOMIC-HYDROGEN WITH BR- AND I- IN AQUEOUS-SOLUTION SO JOURNAL OF PHYSICAL CHEMISTRY LA English DT Article ID HYDRATED ELECTRONS; FREE-RADICALS; POLARIZATION; RADIOLYSIS AB Electron paramagnetic resonance free induction decay (FID) attenuation measurements are reported for the reaction of H atoms with Br-, IX-, and 2-propanol in aqueous solution. At 25-degrees-C, we obtain scavenging rate constants of (1.7 +/- 0.3) X 10(6) M-1 s-1 for Br-, (2.8 +/- 0.4) X 10(8) M-1 s-1 for IX-, and (9.0 +/- 2.0) X 10(7) M-1 s-1 for 2-propanol. Very small activation energies of 6.3 +/- 6.2 kJ/mol for the Br- reaction, and 1.8 +/- 4.6 kJ/mol for the IX- reaction, were found in the 10-58-degrees-C temperature range. Anomalous chemically induced dynamic electron polarization (CIDEP) of the H atom in the presence of the halide ions suggests that a near-equilibrium H + X- half arrow right over half arrow left HX- is approached on the 5-mus time scale of the FID experiment, with the reverse rate on the order of 10(6) s-1. The proposed equilibrium resolves a number of apparent contradictions in previous work on these reaction systems. C1 AECL RES,WHITESELL LABS,PINAWA R0E 1LO,MB,CANADA. RP BARTELS, DM (reprint author), ARGONNE NATL LAB,DIV CHEM,ARGONNE,IL 60439, USA. NR 20 TC 33 Z9 33 U1 0 U2 6 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0022-3654 J9 J PHYS CHEM-US JI J. Phys. Chem. PD APR 22 PY 1993 VL 97 IS 16 BP 4101 EP 4105 DI 10.1021/j100118a028 PG 5 WC Chemistry, Physical SC Chemistry GA KY466 UT WOS:A1993KY46600029 ER PT J AU NICHOLAS, JB TROUW, FR MERTZ, JE ITON, LE HOPFINGER, AJ AF NICHOLAS, JB TROUW, FR MERTZ, JE ITON, LE HOPFINGER, AJ TI MOLECULAR-DYNAMICS SIMULATION OF PROPANE AND METHANE IN SILICALITE SO JOURNAL OF PHYSICAL CHEMISTRY LA English DT Article ID THERMODYNAMIC ADSORPTION CHARACTERISTICS; ATOM-ATOM APPROXIMATION; FORCE-FIELD; STATISTICAL CALCULATION; ZSM-5 ZEOLITE; DIFFUSION; WATER; HYDROCARBONS; MOBILITY; ETHANE AB We have investigated the diffusion of propane and methane in the molecular sieve silicalite by computer simulation using energy minimization and molecular dynamics techniques. We present heats of adsorption and self-diffusion constants, calculated using four sets of nonbonded interactions, and compare them to experimental values. Extensive simulation results for large ensembles of methanes in a rigid-molecule approximation are presented. Methane is studied at infinite dilution and at loadings of 2, 4, 8, 12, and 16 molecules per unit cell. Theoretical self-diffusion constants range from 11.5 x 10(-5) to 2.0 X 10(-5) cm2/s at 300 K, in excellent agreement with pulsed field-gradient spin-echo nuclear magnetic resonance measurements. Simulations of propane allowed free movement of all the internal coordinates of the molecule and incorporated large ensembles to achieve accurate representations of bulk properties. Propane is studied at infinite dilution and loadings of 4 and 12 molecules per unit cell. The corresponding theoretical self-diffusion constants are 2.3 x 10(-5) and 6.0 x 10(-7) cm2/s at 300 K. These simulated diffusion rates are also in excellent agreement with NMR measurements. Center-of-mass time distributions were calculated and energy minimizations of the molecules within the zeolite lattice were done. These analyses show that the zigzag channels are the favored residence sites for both methane and propane. The calculated isosteric heats of adsorption of methane and propane are -5.8 and -10.3 kcal/mol, respectively, in good agreement with experimental values. Both adsorbate-silicalite and adsorbate-adsorbate interactions are shown to have an effect on the packing of the molecules in the zeolite. In addition, dynamic effects related to the anisotropy of diffusion in the silicalite lattice also have a role in packing. The microscopic diffusive behavior of the molecules is dicussed and compared to the classical jump diffusion model. C1 UNIV ILLINOIS,DEPT CHEM,CHICAGO,IL 60680. ARGONNE NATL LAB,DIV INTENSE PULSED NEUTRON SOURCE,ARGONNE,IL 60439. ARGONNE NATL LAB,DIV MAT SCI,ARGONNE,IL 60439. CRAY RES INST,EAGAN,MN 55121. NR 60 TC 121 Z9 122 U1 9 U2 29 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0022-3654 J9 J PHYS CHEM-US JI J. Phys. Chem. PD APR 22 PY 1993 VL 97 IS 16 BP 4149 EP 4163 DI 10.1021/j100118a035 PG 15 WC Chemistry, Physical SC Chemistry GA KY466 UT WOS:A1993KY46600036 ER PT J AU KHANRA, BC KING, TS AF KHANRA, BC KING, TS TI STUDIES OF THE SEGREGATION DEPENDENCE OF PROTON KNIGHT-SHIFTS IN RU-CU BIMETALLICS SO JOURNAL OF PHYSICAL CHEMISTRY LA English DT Article ID HYDROGEN CHEMISORPTION; ADSORBED HYDROGEN; ADSORPTION; CATALYSTS; SURFACE; NMR; OCCUPATION; RU(0001); SITES AB The concentration dependence of proton Knight shifts associated with chemisorbed hydrogen on Ru-Cu bimetallics has been studied in terms of conduction electron polarization and surface segregation. Comparison of the calculated results with the experimental results suggests that the proton Knight shift for Ru-Cu particles results mainly from the hydrogen atoms experiencing a hyperfine interaction with three Ru first nearest neighbors. C1 US DOE,AMES LAB,AMES,IA 50011. IOWA STATE UNIV SCI & TECHNOL,DEPT CHEM ENGN,AMES,IA 50011. NR 13 TC 6 Z9 6 U1 1 U2 2 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0022-3654 J9 J PHYS CHEM-US JI J. Phys. Chem. PD APR 22 PY 1993 VL 97 IS 16 BP 4164 EP 4166 DI 10.1021/j100118a036 PG 3 WC Chemistry, Physical SC Chemistry GA KY466 UT WOS:A1993KY46600037 ER PT J AU MAGINN, EJ BELL, AT THEODOROU, DN AF MAGINN, EJ BELL, AT THEODOROU, DN TI TRANSPORT DIFFUSIVITY OF METHANE IN SILICALITE FROM EQUILIBRIUM AND NONEQUILIBRIUM SIMULATIONS SO JOURNAL OF PHYSICAL CHEMISTRY LA English DT Article ID MOLECULAR-DYNAMICS; SELF-DIFFUSION; CONCENTRATION-DEPENDENCE; 5A ZEOLITE; ONE-COMPONENT; MONTE-CARLO; SORPTION; ADSORPTION; ZSM-5; HYDROCARBONS AB The results of equilibrium and nonequilibrium simulations designed to predict the transport diffusivity of methane in silicalite are presented. The results are compared with equilibrium molecular dynamics calculations of the self-diffusivity for the same system, as well as with the Darken model, which is often invoked to relate self-diffusivities and transport diffusivities in zeolites. Good agreement is found between simulation results and the Darken model. Systems that are expected to deviate from the Darken model are discussed. C1 UNIV CALIF BERKELEY,DEPT CHEM ENGN,BERKELEY,CA 94720. LAWRENCE BERKELEY LAB,CTR ADV MAT,BERKELEY,CA 94720. OI Theodorou, Doros/0000-0002-4763-9739; Bell, Alexis/0000-0002-5738-4645 NR 47 TC 229 Z9 232 U1 4 U2 44 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0022-3654 J9 J PHYS CHEM-US JI J. Phys. Chem. PD APR 22 PY 1993 VL 97 IS 16 BP 4173 EP 4181 DI 10.1021/j100118a038 PG 9 WC Chemistry, Physical SC Chemistry GA KY466 UT WOS:A1993KY46600039 ER PT J AU ANNE, R ARNELL, SE BIMBOT, R DOGNY, S EMLING, H ESBENSEN, H GUILLEMAUDMUELLER, D HANSEN, PG HORNSHOJ, P HUMBERT, F JONSON, B KEIM, M LEWITOWICZ, M MOLLER, P MUELLER, AC NEUGART, R NILSSON, T NYMAN, G POUGHEON, F RIISAGER, K SAINTLAURENT, MG SCHRIEDER, G SORLIN, O TENGBLAD, O ROLANDER, KW WOLSKI, D AF ANNE, R ARNELL, SE BIMBOT, R DOGNY, S EMLING, H ESBENSEN, H GUILLEMAUDMUELLER, D HANSEN, PG HORNSHOJ, P HUMBERT, F JONSON, B KEIM, M LEWITOWICZ, M MOLLER, P MUELLER, AC NEUGART, R NILSSON, T NYMAN, G POUGHEON, F RIISAGER, K SAINTLAURENT, MG SCHRIEDER, G SORLIN, O TENGBLAD, O ROLANDER, KW WOLSKI, D TI DISSOCIATION REACTIONS OF THE BE-11 ONE-NEUTRON HALO - THE INTERPLAY BETWEEN STRUCTURE AND REACTION-MECHANISM SO PHYSICS LETTERS B LA English DT Article ID CROSS-SECTIONS; LI-11 AB The angular distributions of the forward neutrons in the exclusive (Be-10 + n) channel have been measured. They can be accounted for quantitatively and without free parameters in terms of Coulomb and diffraction dissociation. The results show that the transverse momentum distributions result from an interplay between the tail of the wave function (the halo) and the reaction mechanism. C1 CHALMERS UNIV TECHNOL,INST FYS,S-41296 GOTHENBURG,SWEDEN. CNRS,INST PHYS NUCL,IN2P3,F-91406 ORSAY,FRANCE. GSI DARMSTADT,W-6100 DARMSTADT,GERMANY. ARGONNE NATL LAB,DEPT PHYS,ARGONNE,IL 60439. AARHUS UNIV,INST FYS & ASTRON,DK-8000 AARHUS,DENMARK. SOLTAN INST PROBLEMOW JADROWYCH,PL-05400 OTWOCK,POLAND. UNIV MAINZ,INST PHYS,W-6500 MAINZ,GERMANY. TH DARMSTADT,INST KERNPHYS,W-6100 DARMSTADT,GERMANY. CERN,DIV PPE,CH-1211 GENEVA 23,SWITZERLAND. RP ANNE, R (reprint author), GANIL,F-14021 CAEN,FRANCE. RI Nilsson, Thomas/B-7705-2009; Jonson, Bjorn/B-2816-2014; OI Nilsson, Thomas/0000-0002-6990-947X; Tengblad, Olof/0000-0002-5813-0022 NR 22 TC 57 Z9 58 U1 0 U2 2 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 APR 22 PY 1993 VL 304 IS 1-2 BP 55 EP 59 DI 10.1016/0370-2693(93)91399-8 PG 5 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA KY312 UT WOS:A1993KY31200010 ER PT J AU BREKKE, L DYKSTRA, H FALK, AF IMBO, TD AF BREKKE, L DYKSTRA, H FALK, AF IMBO, TD TI NOVEL SPIN AND STATISTICAL PROPERTIES OF NONABELIAN VORTICES SO PHYSICS LETTERS B LA English DT Article ID EXOTIC STATISTICS; HAIR AB We study the statistics of vortices which appear in (2+ 1)-dimensional spontaneously broken gauge theories, where a compact group G breaks to a finite nonabelian subgroup H. Two simple models are presented. In the first, a quantum state which is symmetric under the interchange of a pair of indistinguishable vortices can be transformed into an antisymmetric state after the passage through the system of a third vortex with an appropriate H-flux element. Further, there exist states containing two indistinguishable spinless vortices which obey Fermi statistics. In the second model, fractional analogues of the above behaviors occur. Also, composites of vortices in this theory may possess fractional ''Cheshire spin'' which can be changed by passing an additional vortex through the system. C1 STANDFORD LINEAR ACCELERATOR CTR,STANFORD,CA 94309. FERMILAB NATL ACCELERATOR LAB,BATAVIA,IL 60510. RP BREKKE, L (reprint author), UNIV ILLINOIS,DEPT PHYS,CHICAGO,IL 60607, USA. NR 15 TC 7 Z9 7 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 APR 22 PY 1993 VL 304 IS 1-2 BP 127 EP 133 DI 10.1016/0370-2693(93)91411-F PG 7 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA KY312 UT WOS:A1993KY31200022 ER PT J AU BOTTS, J MORFIN, JG OWENS, JF QIU, JW TUNG, WK WEERTS, H AF BOTTS, J MORFIN, JG OWENS, JF QIU, JW TUNG, WK WEERTS, H TI CTEQ PARTON DISTRIBUTIONS AND FLAVOR DEPENDENCE OF SEA QUARKS SO PHYSICS LETTERS B LA English DT Article ID QCD; SCATTERING; NEUTRINO; DIMUONS AB This paper describes salient features of new sets of parton distributions obtained by the CTEQ Collaboration based on a comprehensive QCD global analysis of all available data. The accuracy of the new data on deep inelastic scattering structure functions obtained by the very high statistics NMC and CCFR experiments provides unprecedented sensitivity to the flavor dependence of the sea-quark distributions. In addition to much better determination of the small-x dependence of all parton distributions, we found: (i) the strange quark distribution is much softer than the non-strange sea quarks and rises above the latter at small-x; and (ii) the difference dBAR - uBAR changes sign as a function of x. A few alternative sets of viable distributions with conventional assumptions are also discussed. C1 FERMILAB NATL ACCELERATOR LAB,BATAVIA,IL 60510. FLORIDA STATE UNIV,TALLAHASSEE,FL 32306. IOWA STATE UNIV SCI & TECHNOL,AMES,IA 50011. RP BOTTS, J (reprint author), MICHIGAN STATE UNIV,E LANSING,MI 48824, USA. NR 23 TC 255 Z9 256 U1 0 U2 3 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 APR 22 PY 1993 VL 304 IS 1-2 BP 159 EP 166 DI 10.1016/0370-2693(93)91416-K PG 8 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA KY312 UT WOS:A1993KY31200027 ER PT J AU OCONNELL, TM GERIG, JT WILLIAMS, PG AF OCONNELL, TM GERIG, JT WILLIAMS, PG TI EXAMINATION OF THE STRUCTURE AND DYNAMICS OF TOSYLCHYMOTRYPSIN AT PH 4 BY TRITIUM NMR-SPECTROSCOPY SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Article ID NUCLEAR MAGNETIC-RESONANCE; ACTIVE-SITE; STEREOCHEMISTRY; BIOSYNTHESIS; CHYMOTRYPSIN; RELAXATION; BINDING; PROTEIN AB Tritium NMR spectroscopy of specifically tritiated and tritiated/deuterated derivatives of tosylchymotrypsin has been used to examine the properties of the tosyl group in this protein. The presence of several tritiated isotopomers complicates analysis of experiments and extensive computer simulations of the composite relaxation behavior of the collection of tritiated species present were used in conjunction with models developed from crystallographic results to interpret the observations made. These analyses suggest that the tosyl group of tosylchymotrypsin at pH 4 is highly mobile in solution and, on average, only occupies the location in the protein that is observed in the solid state about 50% of the time. C1 UNIV CALIF SANTA BARBARA,DEPT CHEM,SANTA BARBARA,CA 93106. LAWRENCE BERKELEY LAB,NATL TRITIUM LABELING FACIL,BERKELEY,CA 94720. NR 41 TC 11 Z9 11 U1 0 U2 0 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 APR 21 PY 1993 VL 115 IS 8 BP 3048 EP 3055 DI 10.1021/ja00061a002 PG 8 WC Chemistry, Multidisciplinary SC Chemistry GA KY506 UT WOS:A1993KY50600002 ER PT J AU LICHTENBERGER, DL RENSHAW, SK BULLOCK, RM AF LICHTENBERGER, DL RENSHAW, SK BULLOCK, RM TI METAL ACETYLIDE BONDING IN (ETA-5-C5H5)FE(CO)2CCR COMPOUNDS - MEASURES OF METAL-D-PI-ACETYLIDE-PI INTERACTIONS FROM PHOTOELECTRON-SPECTROSCOPY SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Article ID DIVERGENT FLUXIONAL BEHAVIOR; ELECTRONIC-STRUCTURE; VALENCE IONIZATIONS; MOLECULAR-STRUCTURE; COMPLEXES; VINYLIDENE; RHODIUM; CHEMISTRY; ACTIVATION; DINUCLEAR AB Gas-phase He I and He II photoelectron spectroscopy is used to experimentally determine the bonding interactions of eta1-acetylide ligands in (eta5-C5H5)Fe(CO)2C=CR compounds (R = H, (t)Bu, or phenyl). The spectra show a large amount of interaction between the metal dpi orbitals and the acetylide pi orbitals. Evidence for this is obtained from the splitting of metal-based ionization bands, from the shifts in Cp-based and acetylide-based ionizations, from the changes in ionization cross sections between the He I and He II spectra, and from vibrational fine structure in the metal-based ionizations. The data indicate that the predominant pi interactions between the acetylide ligands and the metal are filled/filled interactions between the occupied acetylide pi bonds and the occupied metal dpi orbitals. The electronic interactions of the C=CR ligands with the metal are compared with those of CH3 (a primiarly sigma donor ligand), halides (pi donor ligands), and C=N (a weak pi* acceptor ligand), and are very similar to the interactions of the chloro ligand. Metal-to-acetylide-pi* back-bonding is extremely small in the acetylide compounds. Varying the acetylide substituent causes significant changes in the sigma and pi donor properties of the C=CR ligand. Compared to C=CH, the C=C(t)Bu ligand is a stronger sigma donor ligand and also has a stronger filled/filled interaction between the metal dpi and acetylide pi orbitals. The electronic mixing with the C=CPh ligand is even more extensive, since the metal dpi orbitals and the C=C pi bonds are further mixed with the phenyl ring pi orbitals. The nature of these pi interactions helps to explain the observed reactivity of electrophiles with ML(n)C=CR compounds and the observed electronic communication along the metal-carbon-carbon atom chain in transition metal-acetylide compounds. C1 BROOKHAVEN NATL LAB,DEPT CHEM,UPTON,NY 11973. RP LICHTENBERGER, DL (reprint author), UNIV ARIZONA,DEPT CHEM,ELECTRON SPECT & SURFACE ANAL LAB,TUCSON,AZ 85721, USA. RI Bullock, R. Morris/L-6802-2016 OI Bullock, R. Morris/0000-0001-6306-4851 NR 59 TC 127 Z9 127 U1 0 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 APR 21 PY 1993 VL 115 IS 8 BP 3276 EP 3285 DI 10.1021/ja00061a028 PG 10 WC Chemistry, Multidisciplinary SC Chemistry GA KY506 UT WOS:A1993KY50600028 ER PT J AU CARRADO, KA WASSERMAN, SR AF CARRADO, KA WASSERMAN, SR TI X-RAY ABSORPTION STUDY OF THE SOLVATED CU(II) ION - TRANSITION FROM A SOLVATED SOLID TO THE DISSOLVED STATE SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Note ID NEAR-EDGE STRUCTURE; AQUEOUS-SOLUTION; FINE-STRUCTURE; CLAY CATALYSTS; EXAFS; COORDINATION; SPECTROSCOPY; COPPER; SITE; CU C1 ARGONNE NATL LAB,DIV CHEM,9700 S CASS AVE,ARGONNE,IL 60439. NR 25 TC 14 Z9 14 U1 1 U2 1 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 APR 21 PY 1993 VL 115 IS 8 BP 3394 EP 3395 DI 10.1021/ja00061a074 PG 2 WC Chemistry, Multidisciplinary SC Chemistry GA KY506 UT WOS:A1993KY50600074 ER PT J AU SPANN, JF MALONEY, DJ LAWSON, WF CASLETON, KH AF SPANN, JF MALONEY, DJ LAWSON, WF CASLETON, KH TI RESPONSE OF 2-PHASE DROPLETS TO INTENSE ELECTROMAGNETIC-RADIATION SO APPLIED OPTICS LA English DT Article ID 10.6-MU-M LASER PULSE; EXPLOSIVE VAPORIZATION; WATER DROPLETS; ELECTRODYNAMIC BALANCE; CO2-LASER; PARTICLES; BREAKDOWN; DYNAMICS; SIZE; MASS AB The response of two-phase droplets to intense radiant heating is studied to determine the incident power that is required for causing explosive boiling in the liquid phase. The droplets studied consist of strongly absorbing coal particles dispersed in a weakly absorbing water medium. Experiments are performed by confining droplets (radii = 37, 55, and 80 mum) electrodynamically and irradiating them from two sides with pulsed laser beams. Emphasis is placed on the transition region from accelerated droplet vaporization to droplet superheating and explosive boiling. The time scale observed for explosive boiling is more than 2 orders of magnitude longer than published values for pure liquids. The delayed response is the result of energy transfer limitations between the absorbing solid phase and the surrounding liquid. C1 US DOE, MORGANTOWN ENERGY TECHNOL CTR, MORGANTOWN, WV 26507 USA. NR 33 TC 4 Z9 4 U1 0 U2 1 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA SN 0003-6935 J9 APPL OPTICS JI Appl. Optics PD APR 20 PY 1993 VL 32 IS 12 BP 2152 EP 2158 PG 7 WC Optics SC Optics GA KX397 UT WOS:A1993KX39700026 PM 20820360 ER PT J AU WHITE, RL KINNEY, AL BECKER, RH AF WHITE, RL KINNEY, AL BECKER, RH TI NEW HIGH-REDSHIFT DAMPED LYMAN-ALPHA ABSORPTION SYSTEMS AND THE REDSHIFT EVOLUTION OF DAMPED ABSORBERS SO ASTROPHYSICAL JOURNAL LA English DT Article DE COSMOLOGY, OBSERVATIONS; GALAXIES, DISTANCES AND REDSHIFTS; GALAXIES, EVOLUTION ID SPECTRUM RADIO-SOURCES; DISTRIBUTIONS; CLOUDS; QSOS AB We have discovered two high-redshift (z(abs) = 3.388 and 2.908) damped Lyalpha absorption systems and a third possible damped system (z(abs) = 3.080) while obtaining spectra of optical counterparts from a sample of flat spectrum radio sources. These three systems all have higher redshifts than any previously known damped Lyalpha absorption systems in the spectra of radio-loud quasars, and they are among the highest redshift damped Lyalpha systems known. It is unlikely that we would have found as many as two or three damped Lyalpha absorption systems among our sample unless there is a significant increase in the area-weighted comoving density of damped systems for z greater than or similar to 3. Using data from this paper combined with previous surveys for damped Lyalpha absorbers, we derive the area-weighted comoving density of damped Lyalpha absorbers and find that it increases sharply at redshifts above z = 3. A constant comoving density can be ruled out at the 95% confidence level if q0 = 0 and the 97% confidence level if q0 = 0.5. This is the first good statistical evidence for evolution in the number (or size) of damped Lyalpha absorbers at high redshift. We argue that the most likely explanation for the rapid disappearance of damped Lyalpha absorbers between z = 3.5 and z = 3 is that we are observing the epoch of galaxy formation. C1 SPACE TELESCOPE SCI INST,BALTIMORE,MD 21218. UNIV CALIF DAVIS,DEPT PHYS,DAVIS,CA 95616. LAWRENCE LIVERMORE NATL LAB,INST GEOPHYS & PLANETARY PHYS,LIVERMORE,CA 94550. RP WHITE, RL (reprint author), UNIV COLORADO,JOINT INST LAB ASTROPHYS,BOULDER,CO 80303, USA. RI White, Richard/A-8143-2012 NR 22 TC 39 Z9 39 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 APR 20 PY 1993 VL 407 IS 2 BP 456 EP 469 DI 10.1086/172529 PN 1 PG 14 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA KX399 UT WOS:A1993KX39900003 ER PT J AU COLIN, P SCHRAMM, DN AF COLIN, P SCHRAMM, DN TI CHEMICAL AND LUMINOSITY EVOLUTION, AND COUNTS OF GALAXIES IN A MERGER MODEL SO ASTROPHYSICAL JOURNAL LA English DT Article DE GALAXIES, ABUNDANCES; GALAXIES, EVOLUTION; GALAXIES, INTERACTIONS; STARS, FORMATION ID SOLAR NEIGHBORHOOD; FAINT GALAXIES; STAR FORMATION; MASS FUNCTION; HALO STARS; RATES; DISK; AGE; NUCLEOSYNTHESIS; METALLICITY AB A merger model is applied to the chemical and luminosity evolution of galaxies. Two aspects are focused on. The first is the problem of abundance ratios as a function of metallicity. The second is related to the luminosity evolution of galaxies. In relation to the former, we calculate the evolution of several chemical elements exploring a broad space of possible star formation rates, including those derived using phenomenological arguments from a multiple merger galaxy formation scenario. We are able to reproduce the observed plateau in the ratio of the abundances of oxygen to iron versus metallicity as a direct consequence of one of the merging SFR used; we have utilized a standard Type II supernovae nucleosynthesis scenario coupled with a reasonable binary model for Type Ia supernovae and its consequent nucleosynthetic yields. Following the consequent luminosity effects in a straightforward way enables the estimation of the evolution of bolometric luminosity. We have used our recently developed code for photometric evolution of galaxies to make a preliminary computation of the number-magnitude relationship, assuming a standard picture of galaxy evolution, in the B and K bands. C1 NASA,FERMILAB ASTROPHYS CTR,BATAVIA,IL 60510. NATL AUTONOMOUS UNIV MEXICO,INST ASTRON,MEXICO CITY 04510,DF,MEXICO. RP COLIN, P (reprint author), UNIV CHICAGO,5640 S ELLIS AVE,CHICAGO,IL 60637, USA. NR 65 TC 6 Z9 6 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 APR 20 PY 1993 VL 407 IS 2 BP 510 EP 518 DI 10.1086/172532 PN 1 PG 9 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA KX399 UT WOS:A1993KX39900006 ER PT J AU MIRALLES, JA VANRIPER, KA LATTIMER, JM AF MIRALLES, JA VANRIPER, KA LATTIMER, JM TI THE BOLTZMANN-EQUATION IN GENERAL RELATIVISTIC ROTATING SYSTEMS - COOLING OF ROTATING NEUTRON-STARS SO ASTROPHYSICAL JOURNAL LA English DT Article DE RADIATIVE TRANSFER; RELATIVITY STARS, ROTATION; STARS, NEUTRON ID EVOLUTION; EMISSION AB We derive the general relativistic Boltzmann equation for massless particles in a stationary axisymmetric metric. The energy and angles of the particles are written in the comoving frame in order to use the local expressions for the collision terms. The zero and first-order moment equations in both spectral integrated and nonintegrated form are obtained. From these we derive the thermal equilibrium condition and the diffusion approximation in a relativistic rotating axisymmetric star. We check the equations by recovering.the spherically symmetric case and the heat conduction approximation (equilibrium diffusion limit) for axisymmetry. The effects of rotation on the cooling of rotating neutron stars are studied using Hartle's formalism for the rotational deformation together with the cooling equation we derive. C1 UNIV VALENCIA,DEPT FIS TEOR,E-46100 BURJASSOT,SPAIN. LOS ALAMOS NATL LAB,DIV APPL THEORET PHYS,RADIAT TRANSPORT GRP,LOS ALAMOS,NM 87545. RP MIRALLES, JA (reprint author), SUNY STONY BROOK,DEPT EARTH & SPACE SCI,ASTRON PROGRAM,STONY BROOK,NY 11794, USA. NR 28 TC 11 Z9 11 U1 0 U2 2 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 S WOODLAWN AVE, CHICAGO, IL 60637 SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD APR 20 PY 1993 VL 407 IS 2 BP 687 EP 698 DI 10.1086/172550 PN 1 PG 12 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA KX399 UT WOS:A1993KX39900024 ER PT J AU BRANDES, HK LARIMER, FW GECK, MK STRINGER, CD SCHURMANN, P HARTMAN, FC AF BRANDES, HK LARIMER, FW GECK, MK STRINGER, CD SCHURMANN, P HARTMAN, FC TI FUNCTIONAL-ANALYSIS OF ACTIVE-SITE CYSTEINYL RESIDUES OF THIOREDOXIN-F BY USE OF SITE-DIRECTED MUTANTS SO FASEB JOURNAL LA English DT Meeting Abstract C1 OAK RIDGE NATL LAB,PROT ENGN PROGRAM,OAK RIDGE,TN 37831. UNIV NEUCHATEL,BIOCHIM LAB,CH-2000 NEUCHATEL,SWITZERLAND. NR 2 TC 0 Z9 0 U1 2 U2 2 PU FEDERATION AMER SOC EXP BIOL PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814-3998 SN 0892-6638 J9 FASEB J JI Faseb J. PD APR 20 PY 1993 VL 7 IS 7 BP A1104 EP A1104 PG 1 WC Biochemistry & Molecular Biology; Biology; Cell Biology SC Biochemistry & Molecular Biology; Life Sciences & Biomedicine - Other Topics; Cell Biology GA KY848 UT WOS:A1993KY84800381 ER PT J AU CAMPION, SR NIYOGI, SK AF CAMPION, SR NIYOGI, SK TI CUMULATIVE EFFECT OF DOUBLE-SITE MUTATIONS OF HUMAN EGF ON RECEPTOR-BINDING SO FASEB JOURNAL LA English DT Meeting Abstract C1 OAK RIDGE NATL LAB,DIV BIOL,OAK RIDGE,TN 37831. NR 0 TC 0 Z9 0 U1 0 U2 1 PU FEDERATION AMER SOC EXP BIOL PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814-3998 SN 0892-6638 J9 FASEB J JI Faseb J. PD APR 20 PY 1993 VL 7 IS 7 BP A1238 EP A1238 PG 1 WC Biochemistry & Molecular Biology; Biology; Cell Biology SC Biochemistry & Molecular Biology; Life Sciences & Biomedicine - Other Topics; Cell Biology GA KY848 UT WOS:A1993KY84801159 ER PT J AU GAUL, DF CHUMANOV, G ZHOU, CL PICOREL, R SEIBERT, M SCHENCK, CC COTTON, TM AF GAUL, DF CHUMANOV, G ZHOU, CL PICOREL, R SEIBERT, M SCHENCK, CC COTTON, TM TI CHARACTERIZATION OF PHOTOSYNTHETIC REACTION CENTERS BY SURFACE-ENHANCED RESONANCE RAMAN-SCATTERING SO FASEB JOURNAL LA English DT Meeting Abstract C1 IOWA STATE UNIV SCI & TECHNOL,DEPT CHEM,AMES,IA 50011. CSIC,ESTAC EXPTL AULA DEI,E-50080 ZARAGOZA,SPAIN. NATL RENEWABLE ENERGY LAB,GOLDEN,CO 80401. COLORADO STATE UNIV,DEPT BIOCHEM,FT COLLINS,CO 80523. RI PICOREL, RAFAEL/K-7930-2014 OI PICOREL, RAFAEL/0000-0003-3791-129X NR 0 TC 0 Z9 0 U1 0 U2 0 PU FEDERATION AMER SOC EXP BIOL PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814-3998 SN 0892-6638 J9 FASEB J JI Faseb J. PD APR 20 PY 1993 VL 7 IS 7 BP A1110 EP A1110 PG 1 WC Biochemistry & Molecular Biology; Biology; Cell Biology SC Biochemistry & Molecular Biology; Life Sciences & Biomedicine - Other Topics; Cell Biology GA KY848 UT WOS:A1993KY84800419 ER PT J AU GURLEY, LR VALDEZ, JG BUCHANAN, JS AF GURLEY, LR VALDEZ, JG BUCHANAN, JS TI THE MITOTIC-SPECIFIC PHOSPHORYLATION SITE OF HISTONE H1 DOES NOT CONTAIN THE CONSENSUS SEQUENCE FOR THE CYCLIN-P34CDC2 KINASE SO FASEB JOURNAL LA English DT Meeting Abstract C1 LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545. NR 0 TC 0 Z9 0 U1 0 U2 0 PU FEDERATION AMER SOC EXP BIOL PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814-3998 SN 0892-6638 J9 FASEB J JI Faseb J. PD APR 20 PY 1993 VL 7 IS 7 BP A1094 EP A1094 PG 1 WC Biochemistry & Molecular Biology; Biology; Cell Biology SC Biochemistry & Molecular Biology; Life Sciences & Biomedicine - Other Topics; Cell Biology GA KY848 UT WOS:A1993KY84800322 ER PT J AU HARP, JM ROBERSON, AE UBERBACHER, EC BUNICK, GJ AF HARP, JM ROBERSON, AE UBERBACHER, EC BUNICK, GJ TI CRYSTALLIZATION OF NUCLEOSOME CORE PARTICLES CONTAINING A DNA PALINDROME SO FASEB JOURNAL LA English DT Meeting Abstract C1 UNIV TENNESSEE,OAK RIDGE GRAD SCH BIOMED SCI,OAK RIDGE,TN 37830. OAK RIDGE NATL LAB,DIV ENGN PHYS,OAK RIDGE,TN 37831. OAK RIDGE NATL LAB,DIV MATH,OAK RIDGE,TN 37831. OAK RIDGE NATL LAB,DIV BIOL,OAK RIDGE,TN 37831. NR 1 TC 0 Z9 0 U1 0 U2 0 PU FEDERATION AMER SOC EXP BIOL PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814-3998 SN 0892-6638 J9 FASEB J JI Faseb J. PD APR 20 PY 1993 VL 7 IS 7 BP A1093 EP A1093 PG 1 WC Biochemistry & Molecular Biology; Biology; Cell Biology SC Biochemistry & Molecular Biology; Life Sciences & Biomedicine - Other Topics; Cell Biology GA KY848 UT WOS:A1993KY84800317 ER PT J AU HOLBROOK, SR DUBCHAK, I KIM, SH AF HOLBROOK, SR DUBCHAK, I KIM, SH TI A COMPUTER-PROGRAM FOR PROTEIN-STRUCTURE PREDICTION BY ARTIFICIAL NEURAL NETWORKS SO FASEB JOURNAL LA English DT Meeting Abstract C1 LAWRENCE BERKELEY LAB,DIV STRUCT BIOL,BERKELEY,CA 94720. NR 0 TC 0 Z9 0 U1 0 U2 0 PU FEDERATION AMER SOC EXP BIOL PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814-3998 SN 0892-6638 J9 FASEB J JI Faseb J. PD APR 20 PY 1993 VL 7 IS 7 BP A1284 EP A1284 PG 1 WC Biochemistry & Molecular Biology; Biology; Cell Biology SC Biochemistry & Molecular Biology; Life Sciences & Biomedicine - Other Topics; Cell Biology GA KY848 UT WOS:A1993KY84801429 ER PT J AU LACKS, SA GREENBERG, B AF LACKS, SA GREENBERG, B TI ATYPICAL RIBOSOME BINDING-SITES AND REGULATION OF GENE-EXPRESSION IN THE DPNII RESTRICTION ENZYME-SYSTEM OF STREPTOCOCCUS-PNEUMONIAE SO FASEB JOURNAL LA English DT Meeting Abstract C1 BROOKHAVEN NATL LAB,UPTON,NY 11973. NR 0 TC 0 Z9 0 U1 0 U2 0 PU FEDERATION AMER SOC EXP BIOL PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814-3998 SN 0892-6638 J9 FASEB J JI Faseb J. PD APR 20 PY 1993 VL 7 IS 7 BP A1082 EP A1082 PG 1 WC Biochemistry & Molecular Biology; Biology; Cell Biology SC Biochemistry & Molecular Biology; Life Sciences & Biomedicine - Other Topics; Cell Biology GA KY848 UT WOS:A1993KY84800253 ER PT J AU LEE, TC MALONE, B AF LEE, TC MALONE, B TI ETHER-CONTAINING INOSITOL PHOSPHOLIPIDS IN HL-60, EL-4, AND THY-1-F LYMPHOMA-CELLS SO FASEB JOURNAL LA English DT Meeting Abstract C1 OAK RIDGE ASSOCIATED UNIV,DIV MED SCI,OAK RIDGE,TN 37831. NR 0 TC 0 Z9 0 U1 0 U2 0 PU FEDERATION AMER SOC EXP BIOL PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814-3998 SN 0892-6638 J9 FASEB J JI Faseb J. PD APR 20 PY 1993 VL 7 IS 7 BP A1046 EP A1046 PG 1 WC Biochemistry & Molecular Biology; Biology; Cell Biology SC Biochemistry & Molecular Biology; Life Sciences & Biomedicine - Other Topics; Cell Biology GA KY848 UT WOS:A1993KY84800048 ER PT J AU OU, MC MALONE, B LEE, TC SNYDER, F AF OU, MC MALONE, B LEE, TC SNYDER, F TI TRANSACETYLASE-CATALYZED FORMATION OF ACETYLATED SPHINGOSINES WITH PLATELET-ACTIVATING-FACTOR (PAF) AS THE ACETATE DONOR IN HUMAN HL-60 CELLS SO FASEB JOURNAL LA English DT Meeting Abstract C1 OAK RIDGE ASSOCIATED UNIV,DIV MED SCI,OAK RIDGE,TN 37831. NR 0 TC 1 Z9 1 U1 0 U2 0 PU FEDERATION AMER SOC EXP BIOL PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814-3998 SN 0892-6638 J9 FASEB J JI Faseb J. PD APR 20 PY 1993 VL 7 IS 7 BP A1265 EP A1265 PG 1 WC Biochemistry & Molecular Biology; Biology; Cell Biology SC Biochemistry & Molecular Biology; Life Sciences & Biomedicine - Other Topics; Cell Biology GA KY848 UT WOS:A1993KY84801317 ER PT J AU SERPERSU, E HENDERSON, SJ BUNICK, GJ AF SERPERSU, E HENDERSON, SJ BUNICK, GJ TI CONFORMATIONAL-CHANGES IN PHOSPHOGLYCERATE KINASE UPON SUBSTRATE BINDING SO FASEB JOURNAL LA English DT Meeting Abstract C1 UNIV TENNESSEE,DEPT BIOCHEM,KNOXVILLE,TN 37996. OAK RIDGE NATL LAB,DIV BIOL,OAK RIDGE,TN 37831. NR 0 TC 1 Z9 1 U1 0 U2 0 PU FEDERATION AMER SOC EXP BIOL PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814-3998 SN 0892-6638 J9 FASEB J JI Faseb J. PD APR 20 PY 1993 VL 7 IS 7 BP A1175 EP A1175 PG 1 WC Biochemistry & Molecular Biology; Biology; Cell Biology SC Biochemistry & Molecular Biology; Life Sciences & Biomedicine - Other Topics; Cell Biology GA KY848 UT WOS:A1993KY84800794 ER PT J AU TADAKI, DK NIYOGI, SK AF TADAKI, DK NIYOGI, SK TI FUNCTIONAL IMPORTANCE OF HYDROPHOBICITY AT POSITION-13 OF HUMAN EPIDERMAL GROWTH-FACTOR (HEGF) SO FASEB JOURNAL LA English DT Meeting Abstract C1 OAK RIDGE NATL LAB,PROT ENGN & MOLEC MUTAGENESIS PROGRAM,OAK RIDGE,TN 37831. OAK RIDGE NATL LAB,UNIV TENNESSEE OAK RIDGE GRAD SCH BIOMED SCI,DIV BIOL,OAK RIDGE,TN 37831. NR 0 TC 0 Z9 0 U1 0 U2 0 PU FEDERATION AMER SOC EXP BIOL PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814-3998 SN 0892-6638 J9 FASEB J JI Faseb J. PD APR 20 PY 1993 VL 7 IS 7 BP A1240 EP A1240 PG 1 WC Biochemistry & Molecular Biology; Biology; Cell Biology SC Biochemistry & Molecular Biology; Life Sciences & Biomedicine - Other Topics; Cell Biology GA KY848 UT WOS:A1993KY84801170 ER PT J AU ROSENBLATT, J DEBONDT, H JANCARIK, J MORGAN, DO KIM, SH AF ROSENBLATT, J DEBONDT, H JANCARIK, J MORGAN, DO KIM, SH TI PURIFICATION AND CRYSTALLIZATION OF HUMAN CYCLIN-DEPENDENT KINASE-2 SO JOURNAL OF MOLECULAR BIOLOGY LA English DT Article DE CELL CYCLE; CYCLIN DEPENDENT KINASE; PROTEIN KINASE; PROTEIN CRYSTALLIZATION; PROTEIN PURIFICATION ID PROTEIN-KINASE; PHOSPHORYLATION; VERTEBRATES; EXPRESSION C1 UNIV CALIF BERKELEY, DEPT CHEM, BERKELEY, CA 94720 USA. LAWRENCE BERKELEY LAB, BERKELEY, CA 94720 USA. RP UNIV CALIF SAN FRANCISCO, DEPT PHYSIOL, SAN FRANCISCO, CA 94143 USA. NR 23 TC 54 Z9 54 U1 2 U2 5 PU ACADEMIC PRESS LTD- ELSEVIER SCIENCE LTD PI LONDON PA 24-28 OVAL RD, LONDON NW1 7DX, ENGLAND SN 0022-2836 EI 1089-8638 J9 J MOL BIOL JI J. Mol. Biol. PD APR 20 PY 1993 VL 230 IS 4 BP 1317 EP 1319 DI 10.1006/jmbi.1993.1248 PG 3 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA LA432 UT WOS:A1993LA43200021 PM 8487311 ER PT J AU HAANAPPEL, EG JOSS, W VAGNER, ID WYDER, P TRUBENBACH, K MATTAUSCH, H SIMON, A MUELLER, FM ASKENAZY, S AF HAANAPPEL, EG JOSS, W VAGNER, ID WYDER, P TRUBENBACH, K MATTAUSCH, H SIMON, A MUELLER, FM ASKENAZY, S TI MAGNETO-OSCILLATIONS IN YBA2CU3O7-DELTA IN HIGH MAGNETIC-FIELDS SO PHYSICA C-SUPERCONDUCTIVITY AND ITS APPLICATIONS LA English DT Article; Proceedings Paper CT 2ND ISRAELI INTERNATIONAL CONF ON HIGH-TEMPERATURE SUPERCONDUCTIVITY CY JAN 04-08, 1992 CL EILAT, ISRAEL SP CNRS, ITALIAN NATL RES COUNCIL, BRIT COUNCIL, USA, EUROPEAN OFF AEROSP RES & DEV, ISRAELI MINIST FOREIGN AFFAIRS, TEL AVIV UNIV, OREN FAMILY CHAIR EXPTL SOLID STATE PHYS AB Magneto-oscillatory signals have been observed in the magnetization of samples of oriented YBa2Cu3O7-delta powders. The experiments have been performed in pulsed magnetic fields up to 52 T. The Fourier transform of these signals analyzed as a function of 1/B is dominated by two peaks at frequencies very close to the dHvA frequencies reported by Fowler et al. (Phys. Rev. Lett. 58, 534 (1992) ). The field dependence of the amplitude of the oscillations is in qualitative agreement with that predicted by a recent theory of Maniv et al. C1 MAX PLANCK INST FESTKORPERFORSCH,W-7000 STUTTGART 80,GERMANY. LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545. CNRS,INSA,SERV CHAMPS MAGNET INTENSES,F-31077 TOULOUSE,FRANCE. RP HAANAPPEL, EG (reprint author), MAX PLANCK INST FESTKORPERFORSCH,HOCHFELD MAGNETLAB,BP 166,GRENOBLE 9,FRANCE. NR 13 TC 13 Z9 13 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4534 J9 PHYSICA C JI Physica C PD APR 20 PY 1993 VL 209 IS 1-3 BP 39 EP 42 DI 10.1016/0921-4534(93)90865-N PG 4 WC Physics, Applied SC Physics GA KZ521 UT WOS:A1993KZ52100012 ER PT J AU PASTERNAK, MP TAYLOR, RD AF PASTERNAK, MP TAYLOR, RD TI PRESSURE-INDUCED METALLIZATION OF MOTT INSULATORS - THE MOTT TRANSITION SO PHYSICA C-SUPERCONDUCTIVITY AND ITS APPLICATIONS LA English DT Article; Proceedings Paper CT 2ND ISRAELI INTERNATIONAL CONF ON HIGH-TEMPERATURE SUPERCONDUCTIVITY CY JAN 04-08, 1992 CL EILAT, ISRAEL SP CNRS, ITALIAN NATL RES COUNCIL, BRIT COUNCIL, USA, EUROPEAN OFF AEROSP RES & DEV, ISRAELI MINIST FOREIGN AFFAIRS, TEL AVIV UNIV, OREN FAMILY CHAIR EXPTL SOLID STATE PHYS ID DIAMOND ANVIL CELL AB High pressure studies using Diamond Anvil Cells were carried out in antiferromagnetic insulator transition metal iodides characterized by their layered structure. Magnetic properties studied by I-129 Mossbauer Spectroscopy, the equation of state obtained from X-ray diffraction and metal insulator transition deduced from R(T,P) provided a detailed analysis of Mott insulators under the high pressure regime and the nature of the pressure induced Mott transition. C1 LOS ALAMOS NATL LAB,DIV PHYS,LOS ALAMOS,NM 87545. RP PASTERNAK, MP (reprint author), TEL AVIV UNIV,SCH PHYS & ASTRON,IL-69978 TEL AVIV,ISRAEL. NR 9 TC 2 Z9 2 U1 2 U2 4 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4534 J9 PHYSICA C JI Physica C PD APR 20 PY 1993 VL 209 IS 1-3 BP 113 EP 116 DI 10.1016/0921-4534(93)90883-R PG 4 WC Physics, Applied SC Physics GA KZ521 UT WOS:A1993KZ52100030 ER PT J AU RADOUSKY, HB GOODWIN, TJ SHELTON, RN AF RADOUSKY, HB GOODWIN, TJ SHELTON, RN TI ABSENCE OF SUPERCONDUCTIVITY IN (PR1.5CE0.5)SR2CU2NBO10 - A GENERAL CORRELATION WITH MAGNETIC-ORDERING SO PHYSICA C-SUPERCONDUCTIVITY AND ITS APPLICATIONS LA English DT Article; Proceedings Paper CT 2ND ISRAELI INTERNATIONAL CONF ON HIGH-TEMPERATURE SUPERCONDUCTIVITY CY JAN 04-08, 1992 CL EILAT, ISRAEL SP CNRS, ITALIAN NATL RES COUNCIL, BRIT COUNCIL, USA, EUROPEAN OFF AEROSP RES & DEV, ISRAELI MINIST FOREIGN AFFAIRS, TEL AVIV UNIV, OREN FAMILY CHAIR EXPTL SOLID STATE PHYS AB (Pr1.5Ce0.5)Sr2Cu2NbO10 is found to be an insulating analog to (Nd1.5Ce0.5)Sr2Cu2NbO10, (Sm1.5Ce0.5)Sr2Cu2NbO10 and (Eu1.5Ce0.5)Sr2Cu2NbO10 which have superconducting transition temperatures near 28 K. (Pr1.5Ce0.5)Sr2Cu2NbO10 is also observed to display two magnetic ordering transitions, near 15 K and 50 K, which are not observed for the Nd, Sm or Eu based materials. This compound is a new example of the absence of superconductivity in a PrBa2Cu3O7 related structure which exhibits an unusually high magnetic ordering temperature relative to the other members of the rare earth series. An argument is made for a general correlation between the absence of superconductivity and the presence of magnetic ordering in these structures. The observation of this correlation in the (R1.5Ce0.5)Sr2Cu2NbO10 system is compared to similar observations in RBa2Cu3O7 and RBa2Cu2NbO8. The physical basis for the general nature of this correlation is discussed in terms of f electron hybridization and die unusual crystal field splitting observed for the Pr ion in the YBCO structure. C1 UNIV CALIF DAVIS,DEPT PHYS,DAVIS,CA 95616. RP RADOUSKY, HB (reprint author), LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94551, USA. NR 8 TC 3 Z9 3 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 APR 20 PY 1993 VL 209 IS 1-3 BP 155 EP 158 DI 10.1016/0921-4534(93)90894-V PG 4 WC Physics, Applied SC Physics GA KZ521 UT WOS:A1993KZ52100041 ER PT J AU KRESIN, VZ REEVES, ME WOLF, SA AF KRESIN, VZ REEVES, ME WOLF, SA TI SUPERCONDUCTIVITY, GAPLESS STATE AND ISOTOPE EFFECT IN THE CUPRATES SO PHYSICA C-SUPERCONDUCTIVITY AND ITS APPLICATIONS LA English DT Article; Proceedings Paper CT 2ND ISRAELI INTERNATIONAL CONF ON HIGH-TEMPERATURE SUPERCONDUCTIVITY CY JAN 04-08, 1992 CL EILAT, ISRAEL SP CNRS, ITALIAN NATL RES COUNCIL, BRIT COUNCIL, USA, EUROPEAN OFF AEROSP RES & DEV, ISRAELI MINIST FOREIGN AFFAIRS, TEL AVIV UNIV, OREN FAMILY CHAIR EXPTL SOLID STATE PHYS ID UPPER CRITICAL-FIELD; MAGNETIC-SUSCEPTIBILITY; CRITICAL-TEMPERATURE; SINGLE-CRYSTALS; YBA2CU3O7; HEAT; TC; PARAMETERS AB The removal of oxygen from YBa2Cu3O7-x has a profound impact on various properties of this compound. The model of induced two gap superconductivity that we developed previously allows us to describe these properties. For example, for compositions between 0 < x <0.15, the energy gap on the chains changes drastically, and in fact. becomes gapless. However, T(c) remains relatively constant, because it is determined mostly by the properties of the planes. We find from specific heat measurements that the electron-phonon coupling on the planes is sufficient to account for the high T(c) in YBa2Cu3O7-x. Furthermore we can explain the unusual doping dependence of the isotope shift to effects of non-adiabaticity of oxygen motion in these compounds. C1 CATHOLIC UNIV AMER,DEPT PHYS,WASHINGTON,DC 20064. USN,RES LAB,WASHINGTON,DC 20375. RP KRESIN, VZ (reprint author), LAWRENCE BERKELEY LAB,BERKELEY,CA 94720, USA. RI Wolf, Stuart/A-7513-2009 NR 44 TC 4 Z9 4 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4534 J9 PHYSICA C JI Physica C PD APR 20 PY 1993 VL 209 IS 1-3 BP 319 EP 326 DI 10.1016/0921-4534(93)90933-H PG 8 WC Physics, Applied SC Physics GA KZ521 UT WOS:A1993KZ52100080 ER PT J AU STERN, EA QIAN, M YACOBY, Y HEALD, SM MAEDA, H AF STERN, EA QIAN, M YACOBY, Y HEALD, SM MAEDA, H TI APICAL CU-O BOND IN YBA2CU3O7-DELTA SUPERCONDUCTORS BY XAFS SO PHYSICA C-SUPERCONDUCTIVITY AND ITS APPLICATIONS LA English DT Article; Proceedings Paper CT 2ND ISRAELI INTERNATIONAL CONF ON HIGH-TEMPERATURE SUPERCONDUCTIVITY CY JAN 04-08, 1992 CL EILAT, ISRAEL SP CNRS, ITALIAN NATL RES COUNCIL, BRIT COUNCIL, USA, EUROPEAN OFF AEROSP RES & DEV, ISRAELI MINIST FOREIGN AFFAIRS, TEL AVIV UNIV, OREN FAMILY CHAIR EXPTL SOLID STATE PHYS ID ABSORPTION-FINE-STRUCTURE; HIGH-TC SUPERCONDUCTORS; 2-COMPONENT SUPERCONDUCTIVITY; AMPLITUDE AB Careful Cu K-edge X-ray absorption fine structure (XAFS) measurements on oriented powders of YBa2Cu3O7-delta were made as a function of temperature, of delta, T(c), method of preparation and grain size. The XAFS data were analyzed for the Cu(I) - O(4) apical bond distance distribution. All samples indicated evidence for a double-peak in the distribution with a splitting of 0.1angstrom, with the clearest case for the delta almost-equal-to 0 samples occuring for the T(c) = 89K 20mum grain samples and the least clear one for the 5mum grain T(c) = 93K sample. There is no significant temperature dependence of the splitting. Because the XAFS evidence for the splitting depends on a small signal, it is prudent to verify its existence by other independent measurements. C1 HEBREW UNIV JERUSALEM,RACAH INST PHYS,JERUSALEM,ISRAEL. BROOKHAVEN NATL LAB,DEPT APPL SCI,UPTON,NY 11973. OKAYAMA UNIV,DEPT CHEM,OKAYAMA 700,JAPAN. RP STERN, EA (reprint author), UNIV WASHINGTON,DEPT PHYS,FM-15,SEATTLE,WA 98195, USA. NR 18 TC 33 Z9 33 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4534 J9 PHYSICA C JI Physica C PD APR 20 PY 1993 VL 209 IS 1-3 BP 331 EP 334 DI 10.1016/0921-4534(93)90935-J PG 4 WC Physics, Applied SC Physics GA KZ521 UT WOS:A1993KZ52100082 ER PT J AU STARKE, U BARBIERI, A MATERER, N VANHOVE, MA SOMORJAI, GA AF STARKE, U BARBIERI, A MATERER, N VANHOVE, MA SOMORJAI, GA TI ETHYLIDYNE ON PT(111) - DETERMINATION OF ADSORPTION SITE, SUBSTRATE RELAXATION AND COVERAGE BY AUTOMATED TENSOR LEED SO SURFACE SCIENCE LA English DT Article ID ENERGY-ELECTRON-DIFFRACTION; SURFACE-STRUCTURE DETERMINATION; CLOSE-PACKED SURFACE; 111 CRYSTAL-FACE; INDUCED RECONSTRUCTION; DEUTERIUM-EXCHANGE; THERMAL-DESORPTION; DELTA-PHI; X 2)-O; ETHYLENE AB The adsorption of ethylidyne on Pt(111) is investigated by low-energy electron diffraction (LEED). An automated search program for LEED structure analysis is used to determine the adsorption geometry from comparison of experiment and theory. The fcc threefold hollow site is preferred by the fit. The carbon-carbon bond distance is 1.49 angstrom and the carbon-platinum bond length 1.91 angstrom. A buckling within the top two substrate layers is detected which corresponds to a local expansion of the first-to-second layer distance underneath the adsorbate by 0.08 angstrom as compared to the bulk value. The three substrate atoms forming the hollow site are closer to one another than in the bulk structure by 0.11 angstrom. A tilt of the carbon-carbon bond by 6-degrees seems to occur and could be indicative of a wagging vibration of this bond. The hydrogen atoms do not contribute to the diffraction that yields the ordered pattern as indicated by the absence of hydrogen related features in the experimental I-V curves, suggesting relatively free rotation of the methyl group about the carbon-carbon axis. Additionally, a distinction between a p(2 x 2) and an average of three domains of a p(2 x 1) structure, which both give rise to the same (2 x 2) LEED pattern, is possible. The p(2 x 2) is favored in the structural analysis, giving an ethylidyne coverage of 0.25 monolayers. C1 UNIV CALIF BERKELEY, DEPT CHEM, BERKELEY, CA 94720 USA. RP LAWRENCE BERKELEY LAB, DIV MAT SCI, BERKELEY, CA 94720 USA. RI Van Hove, Michel/A-9862-2008 OI Van Hove, Michel/0000-0002-8898-6921 NR 55 TC 122 Z9 122 U1 1 U2 8 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0039-6028 EI 1879-2758 J9 SURF SCI JI Surf. Sci. PD APR 20 PY 1993 VL 286 IS 1-2 BP 1 EP 14 DI 10.1016/0039-6028(93)90551-T PG 14 WC Chemistry, Physical; Physics, Condensed Matter SC Chemistry; Physics GA KY199 UT WOS:A1993KY19900008 ER PT J AU LUCAS, CA WONG, GCL DOWER, CS LAMELAS, FJ FUOSS, PH AF LUCAS, CA WONG, GCL DOWER, CS LAMELAS, FJ FUOSS, PH TI INITIAL-STAGES IN THE EPITAXIAL-GROWTH OF NACL ON GE(001) SO SURFACE SCIENCE LA English DT Article ID X-RAY-DIFFRACTION; SURFACE-STRUCTURE; ALKALI-HALIDES; INTERFACE; GE AB We have performed an in situ X-ray scattering study of the initial stages of NaCl/Ge(001) heteroepitaxy. The c(4 x 2) surface reconstruction, characteristic of Ge(001) at low temperature, is suppressed immediately upon deposition of NaCl. However, the (2 x 1) symmetry of the surface unit cell is preserved, even after 6 monolayers (ML) of NaCl have been grown. Analysis of the in-plane, half-integer Bragg reflections, specific to the surface reconstruction, supports a model in which the Ge dimer remains and sodium is adsorbed in the ''valley'' site. Subsequent growth of NaCl on the modified surface occurs through the formation of islands with the thickness of a triple layer (3 ML), which fill in until the triple layer is complete. C1 UNIV EDINBURGH,DEPT PHYS,EDINBURGH EH9 3JZ,MIDLOTHIAN,SCOTLAND. AT&T BELL LABS,MURRAY HILL,NJ 07974. UNIV CALIF BERKELEY,DEPT PHYS,BERKELEY,CA 94720. RP LUCAS, CA (reprint author), LAWRENCE BERKELEY LAB,CTR ADV MAT,DIV MAT SCI,BERKELEY,CA 94720, USA. OI Lucas, Christopher/0000-0001-5743-3868 NR 25 TC 11 Z9 11 U1 0 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 APR 20 PY 1993 VL 286 IS 1-2 BP 46 EP 55 DI 10.1016/0039-6028(93)90554-W PG 10 WC Chemistry, Physical; Physics, Condensed Matter SC Chemistry; Physics GA KY199 UT WOS:A1993KY19900011 ER PT J AU RODACH, T BOHNEN, KP HO, KM AF RODACH, T BOHNEN, KP HO, KM TI 1ST PRINCIPLES CALCULATIONS OF LATTICE-RELAXATION AT LOW INDEX SURFACES OF CU SO SURFACE SCIENCE LA English DT Article ID GROUND-STATE PROPERTIES; ENERGY ELECTRON-DIFFRACTION; ION-SCATTERING; CU(110) SURFACE; INVERSE-PHOTOEMISSION; 5D-TRANSITION METALS; TRANSITION-METALS; SINGLE-CRYSTAL; LEED ANALYSIS; WORK FUNCTION AB Using first principles total energy calculations, the lattice relaxation, surface energy and work function of low index surfaces of Cu are calculated. While the (111) and (100) surfaces show only small relaxation effects, the (110) surface exhibits pronounced multilayer relaxation which is typical for all fcc (110) surfaces. The results are in good agreement with experimental LEED and ion scattering studies. C1 IOWA STATE UNIV SCI & TECHNOL, US DOE, AMES LAB, AMES, IA 50011 USA. IOWA STATE UNIV SCI & TECHNOL, DEPT PHYS, AMES, IA 50011 USA. RP KERNFORSCHUNGSZENTRUM KARLSRUHE GMBH, INST NUKL FESTKORPERPHYS, POSTFACH 3640, W-7500 KARLSRUHE 1, GERMANY. NR 51 TC 57 Z9 58 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0039-6028 EI 1879-2758 J9 SURF SCI JI Surf. Sci. PD APR 20 PY 1993 VL 286 IS 1-2 BP 66 EP 72 DI 10.1016/0039-6028(93)90556-Y PG 7 WC Chemistry, Physical; Physics, Condensed Matter SC Chemistry; Physics GA KY199 UT WOS:A1993KY19900013 ER PT J AU LEE, G SPRUNGER, PT PLUMMER, EW AF LEE, G SPRUNGER, PT PLUMMER, EW TI SURFACE-PLASMON DISPERSION AND DAMPING ON AG(110) SO SURFACE SCIENCE LA English DT Letter ID ENERGY-LOSS SPECTROSCOPY; AG SINGLE-CRYSTALS; VOLUME PLASMON; SILVER; METALS AB The surface plasmon excitation on the Ag(110) surface along two high symmetry directions, [110BAR] and [001], has been investigated using angle-resolved electron-energy loss spectroscopy. While the surface plasmon energies at q(parallel-to) almost-equal-to 0 are found to be equal and to agree with reported values for Ag(100) and Ag(111), the dispersions are anisotropic and different from those reported for the other crystal faces. The dispersions can be fitted with second order polynomials in powers of the parallel momentum (q(parallel-to). The anisotropy in the dispersions appears in the quadratic term. This may indicate the influence of bulk contributions to the anisotropic surface plasmon dispersion. In contrast to the energy of the plasmon, the linewidth is isotropic, dependent only on the magnitude of q(parallel-to). The qualitatively different dispersion and the linewidth for Ag(110) compared to those reported for Ag(100) by Rocca et al. [Phys. Rev. Lett. 64 (1990) 2398] indicate a strong face dependence of the surface plasmon of silver. C1 OAK RIDGE NATL LAB, DIV SOLID STATE, OAK RIDGE, TN 37831 USA. UNIV TENNESSEE, DEPT PHYS & ASTRON, KNOXVILLE, TN 37996 USA. RP UNIV PENN, DEPT PHYS, PHILADELPHIA, PA 19104 USA. NR 35 TC 27 Z9 27 U1 0 U2 8 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0039-6028 EI 1879-2758 J9 SURF SCI JI Surf. Sci. PD APR 20 PY 1993 VL 286 IS 1-2 BP L547 EP L553 PG 7 WC Chemistry, Physical; Physics, Condensed Matter SC Chemistry; Physics GA KY199 UT WOS:A1993KY19900004 ER PT J AU WEI, SH LAKS, DB ZUNGER, A AF WEI, SH LAKS, DB ZUNGER, A TI DEPENDENCE OF THE OPTICAL-PROPERTIES OF SEMICONDUCTOR ALLOYS ON THE DEGREE OF LONG-RANGE ORDER SO APPLIED PHYSICS LETTERS LA English DT Article AB Many III-V semiconductor alloys exhibit spontaneous [111] alternate monolayer ordering when grown from the vapor phase. This is manifested by the splitting of the valence-band maximum and by a reduction in the direct band gap. We show here how these features can be used to deduce quantitatively the degree of long-range order in a given sample. Examples are given for Ga0.5In0.5P and Ga0.5In0.5As alloys. RP WEI, SH (reprint author), NATL RENEWABLE ENERGY LAB,GOLDEN,CO 80401, USA. RI Zunger, Alex/A-6733-2013 NR 17 TC 119 Z9 119 U1 0 U2 8 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD APR 19 PY 1993 VL 62 IS 16 BP 1937 EP 1939 DI 10.1063/1.109496 PG 3 WC Physics, Applied SC Physics GA KX554 UT WOS:A1993KX55400028 ER PT J AU SIEGEL, RW AF SIEGEL, RW TI NANOPHASE MATERIALS ASSEMBLED FROM ATOM CLUSTERS SO MATERIALS SCIENCE AND ENGINEERING B-SOLID STATE MATERIALS FOR ADVANCED TECHNOLOGY LA English DT Article ID NANOCRYSTALLINE PALLADIUM; SINTERING CHARACTERISTICS; TIO2; MICROSTRUCTURE; TEMPERATURE; PARTICLES; DIFFUSION; CERAMICS; COPPER AB Nanometer-scale atom clusters (with average diameters below 20 nm) of a variety of materials, including both metals and ceramics, have been synthesized by precursor evaporation and condensation in high-purity gases. The gas-entrained clusters can be collected and subsequently consolidated in situ under ultrahigh vacuum or other controlled atmosphere conditions to create bulk nanophase materials. These ultrafine-grained materials have properties that are often significantly different and considerably improved relative to those of their coarser-grained counterparts. The observed property changes relate to both their small grain sizes and the large percentage of their atoms in grain boundary environments. Since it is becoming apparent that their properties can be engineered during gas-phase synthesis and subsequent processing, nanophase materials assembled from atom clusters should have significant potential for technological development in a variety of applications. Some of the recent research on nanophase materials is reviewed. RP ARGONNE NATL LAB, DIV MAT SCI, ARGONNE, IL 60439 USA. NR 50 TC 66 Z9 67 U1 1 U2 5 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 APR 19 PY 1993 VL 19 IS 1-2 BP 37 EP 43 DI 10.1016/0921-5107(93)90162-G PG 7 WC Materials Science, Multidisciplinary; Physics, Condensed Matter SC Materials Science; Physics GA LB916 UT WOS:A1993LB91600009 ER PT J AU COHEN, ML AF COHEN, ML TI THEORY OF NORMAL AND SUPERCONDUCTING PROPERTIES OF FULLERENE-BASED SOLIDS SO MATERIALS SCIENCE AND ENGINEERING B-SOLID STATE MATERIALS FOR ADVANCED TECHNOLOGY LA English DT Article; Proceedings Paper CT 4TH SYMP ON FUNDAMENTAL APPROACHES TO NEW MATERIAL PHASES, PHYSICS AND CHEMISTRY OF NANOMETER SCALE MATERIALS CY OCT 11-15, 1992 CL KARUIZAWA, JAPAN SP NEC CORP ID DOPED FULLERENES; SPECTROSCOPY AB Recent experiments on the normal state and superconducting properties of fullerene-based solids are used to constrain the proposal theories of the electronic nature of these materials. In general, models of superconductivity based on electron pairing induced by phonons are consistent with electronic band theory and analyses of the measured normal state transport properties. The experiments on normal state transport properties also yield estimates of the parameters characterizing these type II superconductors. It is argued that, at this point, a 'standard model' of phonons interacting with itinerant electrons may be a good first approximation for explaining the properties of the metallic fullerenes. C1 LAWRENCE BERKELEY LAB,DIV MAT SCI,BERKELEY,CA 94720. RP COHEN, ML (reprint author), UNIV CALIF BERKELEY,DEPT PHYS,BERKELEY,CA 94720, USA. NR 31 TC 9 Z9 9 U1 0 U2 1 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE 1 PA PO BOX 564, 1001 LAUSANNE 1, SWITZERLAND SN 0921-5107 J9 MAT SCI ENG B-SOLID JI Mater. Sci. Eng. B-Solid State Mater. Adv. Technol. PD APR 19 PY 1993 VL 19 IS 1-2 BP 111 EP 116 DI 10.1016/0921-5107(93)90174-L PG 6 WC Materials Science, Multidisciplinary; Physics, Condensed Matter SC Materials Science; Physics GA LB916 UT WOS:A1993LB91600021 ER PT J AU SCHLUTER, MA LANNOO, M NEEDELS, M BARAFF, GA TOMANEK, D AF SCHLUTER, MA LANNOO, M NEEDELS, M BARAFF, GA TOMANEK, D TI SUPERCONDUCTIVITY IN ALKALI-INTERCALATED C-60 SO MATERIALS SCIENCE AND ENGINEERING B-SOLID STATE MATERIALS FOR ADVANCED TECHNOLOGY LA English DT Article ID SOLID C60; PRESSURE-DEPENDENCE; MOLECULAR-DYNAMICS; SPECTROSCOPY; KXC60; TEMPERATURE; FULLERENE; K3C60; RAMAN AB Superconductivity observed in alkali-intercalated, solid C60 can be explained on the basis of conventional Bardeen-Cooper-Schrieffer theory. Intramolecular Jahn-Teller-type vibrations with high frequencies couple to conduction electrons in C60 pi orbitals with strength V. The density of these states (N) is determined by the relatively weak intermolecular coupling. This results in a real space factorization of the coupling parameter lambda = NV, which has several experimental consequences. We present detailed calculations that lead to this picture and compare these with existing experiments. C1 ISEN, LILLE, FRANCE. LAWRENCE BERKELEY LAB, BERKELEY, CA 94720 USA. MICHIGAN STATE UNIV, DEPT PHYS & ASTRON, E LANSING, MI 48824 USA. RP AT&T BELL LABS, MURRAY HILL, NJ 07974 USA. RI Tomanek, David/B-3275-2009 OI Tomanek, David/0000-0003-1131-4788 NR 36 TC 9 Z9 9 U1 0 U2 3 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 APR 19 PY 1993 VL 19 IS 1-2 BP 129 EP 134 DI 10.1016/0921-5107(93)90177-O PG 6 WC Materials Science, Multidisciplinary; Physics, Condensed Matter SC Materials Science; Physics GA LB916 UT WOS:A1993LB91600024 ER PT J AU CASTEN, RF CHOU, WT ZAMFIR, NV AF CASTEN, RF CHOU, WT ZAMFIR, NV TI SIGNATURE SPLITTING IN OCTUPOLE BANDS OF VIBRATIONAL AND DEFORMED-NUCLEI SO NUCLEAR PHYSICS A LA English DT Article ID INTERACTING BOSON MODEL; STATES; LIMIT AB Energy staggering in negative-parity bands is studied in both vibrational and deformed regions. Good agreement is found between empirical signature patterns and those calculated in the IBA. It is shown that the calculations in each region depend essentially on only a single parameter. It is found that each kind of structural region displays unique and characteristic signature behaviour. In gamma-soft [O(6)] nuclei the staggering is large and nearly independent of J. Octupole staggering can actually be used as a signature for this symmetry. In deformed regions, signature effects in K = 1- bands show a striking singularity as a function of the filling of a shell, which, both experimentally and theoretically, is shown to be due to the crossing and mixing of K = 0- and 1- bands. Finally, it is found that, albeit for different reasons in different structural regions, the signature splitting of low-lying negative-parity states in vibrational and deformed regions (K = 1- bands) is almost always opposite in phase with that of positive-parity gamma-bands: the only exception is at the very beginning of deformed regions. C1 UNIV COLOGNE,INST KERNPHYS,W-5000 COLOGNE 41,GERMANY. CLARK UNIV,WORCESTER,MA 01610. INST ATOM PHYS,BUCHAREST,ROMANIA. RP CASTEN, RF (reprint author), BROOKHAVEN NATL LAB,UPTON,NY 11973, USA. RI Zamfir, Nicolae Victor/F-2544-2011 NR 12 TC 6 Z9 6 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 APR 19 PY 1993 VL 555 IS 3 BP 563 EP 584 DI 10.1016/0375-9474(93)90488-J PG 22 WC Physics, Nuclear SC Physics GA LJ036 UT WOS:A1993LJ03600003 ER PT J AU MULLER, J BURGDORFER, J AF MULLER, J BURGDORFER, J TI CALCULATION OF LANGMUIR STATES IN DOUBLY EXCITED HELIUM SO PHYSICAL REVIEW LETTERS LA English DT Article ID N HYDROGENIC THRESHOLDS; AUTOIONIZATION; CLASSIFICATION; DYNAMICS; HE AB We have identified a class of high-lying doubly excited resonances in helium which are directly linked to a classical orbit first proposed by Langmuir for the quantization of helium. The projection of the wave function onto three mutually orthogonal planes is shown to trace the Langmuir orbit. This class of resonances forms the top of the intrashell manifold, and are long-lived compared to other members of the same manifold. In the limit Z --> infinity, the wave function traces the modified, asymmetric Langmuir orbit generated by bifurcation of the Langmuir orbit. C1 OAK RIDGE NATL LAB,OAK RIDGE,TN 37831. RP MULLER, J (reprint author), UNIV TENNESSEE,DEPT PHYS,KNOXVILLE,TN 37996, USA. NR 34 TC 24 Z9 24 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 APR 19 PY 1993 VL 70 IS 16 BP 2375 EP 2378 DI 10.1103/PhysRevLett.70.2375 PG 4 WC Physics, Multidisciplinary SC Physics GA KX815 UT WOS:A1993KX81500005 ER PT J AU COOK, DR KAUFMAN, AN TRACY, ER FLA, T AF COOK, DR KAUFMAN, AN TRACY, ER FLA, T TI COLLECTIVE-WAVE SPIN-OFF AND THE GYROBALLISTIC CONTINUUM IN GYRORESONANT ABSORPTION SO PHYSICS LETTERS A LA English DT Article ID VLASOV-POISSON SYSTEM; FAST ALFVEN-WAVE; SPECTRAL DEFORMATION; CYCLOTRON AB Employing ray phase-space for wave propagation, we derive the first analytic formulas for energy transfer from a magnetosonic wave to the minority Bernstein wave, and the absorption profile, for plasma heating via minority gyroresonance. The profile stems from: (1) gyroresonant damping of the Bernstein wave; (2) phase mixing of the kinetic residue. C1 UNIV CALIF BERKELEY,DEPT PHYS,BERKELEY,CA 94720. RP COOK, DR (reprint author), LAWRENCE BERKELEY LAB,BERKELEY,CA 94720, USA. NR 19 TC 8 Z9 8 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 APR 19 PY 1993 VL 175 IS 5 BP 326 EP 333 DI 10.1016/0375-9601(93)90629-E PG 8 WC Physics, Multidisciplinary SC Physics GA KY644 UT WOS:A1993KY64400012 ER PT J AU CAHN, RN AF CAHN, RN TI PLASMA-WAVE ACCELERATORS SO SCIENCE LA English DT Letter RP CAHN, RN (reprint author), LAWRENCE BERKELEY LAB,DIV PHYS,BERKELEY,CA 94720, USA. NR 2 TC 0 Z9 0 U1 0 U2 0 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 SN 0036-8075 J9 SCIENCE JI Science PD APR 16 PY 1993 VL 260 IS 5106 BP 280 EP 280 DI 10.1126/science.260.5106.280 PG 1 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA KX800 UT WOS:A1993KX80000009 PM 17838234 ER PT J AU BUBERNAK, J AF BUBERNAK, J TI LIQUID SCINTILLATION APPLIED TO ALPHA-COUNTING OF PLUTONIUM SO ANALYTICA CHIMICA ACTA LA English DT Article DE ALPHA-COUNTING; LIQUID SCINTILLATION COUNTING; PLUTONIUM AB A liquid scintillation counter has been modified with fast electronic modules to extend its range for a-counting rate measurements. The practical upper limit for accurate counting is about 30 x 10(6) cpm, at which 5% dead-time loss corrections are applied. Solutions of Pu-239 up to 200 g l-1 can be aliquoted directly with capillary pipets, thereby obviating the need for dilutions. The aliquots are mixed with 250 mul of cocktail in 400-mul plastic centrifuge tubes for counting so that waste generation is minimized. Although the counting set-up includes no coincidence circuitry, blanks show less than 10 cpm. Therefore, low-activity samples can also be measured accurately. RP BUBERNAK, J (reprint author), LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545, USA. NR 3 TC 0 Z9 0 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0003-2670 J9 ANAL CHIM ACTA JI Anal. Chim. Acta PD APR 15 PY 1993 VL 276 IS 1 BP 205 EP 210 DI 10.1016/0003-2670(93)85057-Q PG 6 WC Chemistry, Analytical SC Chemistry GA KV575 UT WOS:A1993KV57500026 ER PT J AU PHILIPPIDIS, GP SMITH, TK WYMAN, CE AF PHILIPPIDIS, GP SMITH, TK WYMAN, CE TI STUDY OF THE ENZYMATIC-HYDROLYSIS OF CELLULOSE FOR PRODUCTION OF FUEL ETHANOL BY THE SIMULTANEOUS SACCHARIFICATION AND FERMENTATION PROCESS SO BIOTECHNOLOGY AND BIOENGINEERING LA English DT Article DE ENZYMATIC HYDROLYSIS; CELLULOSE; BETA-GLUCOSIDASE; SSF; ETHANOL ID INHIBITION AB The biochemical conversion of cellulosic biomass to ethanol, a promising alternative fuel, can be carried out efficiently and economically using the simultaneous saccharification and fermentation (SSF) process. The SSF integrates the enzymatic hydrolysis of cellulose to glucose, catalyzed by the synergistic action of cellulase and beta-glucosidase, with the fermentative synthesis of ethanol. Because the enzymatic step determines the availability of glucose to the ethanologenic fermentation, the kinetics of cellulose hydrolysis by cellulase and beta-glucosidase and the susceptibility of the two enzymes to inhibition by hydrolysis and fermentation products are of significant importance to the SSF performance and were investigated under realistic SSF conditions. A previously developed SSF mathematical model was used to conceptualize the depolymerization of cellulose. The model was regressed to the collected data to determine the values of the enzyme parameters and was found to satisfactorily predict the kinetics of cellulose hydrolysis. Cellobiose and glucose were identified as the strongest inhibitors of cellulase and beta-glucosidase, respectively. Experimental and modeling results are presented in light of the impact of enzymatic hydrolysis on fuel ethanol production. RP PHILIPPIDIS, GP (reprint author), NATL RENEWABLE ENERGY LAB,DIV ALTERNAT FUELS,1617 COLE BLVD,GOLDEN,CO 80401, USA. NR 14 TC 184 Z9 186 U1 4 U2 42 PU JOHN WILEY & SONS INC PI NEW YORK PA 605 THIRD AVE, NEW YORK, NY 10158-0012 SN 0006-3592 J9 BIOTECHNOL BIOENG JI Biotechnol. Bioeng. PD APR 15 PY 1993 VL 41 IS 9 BP 846 EP 853 DI 10.1002/bit.260410903 PG 8 WC Biotechnology & Applied Microbiology SC Biotechnology & Applied Microbiology GA KR818 UT WOS:A1993KR81800002 PM 18609632 ER PT J AU TCHERNIA, G GAUTHIER, F MIELOT, F DOMMERGUES, JP YVART, J CHASIS, JA MOHANDAS, N AF TCHERNIA, G GAUTHIER, F MIELOT, F DOMMERGUES, JP YVART, J CHASIS, JA MOHANDAS, N TI INITIAL ASSESSMENT OF THE BENEFICIAL EFFECT OF PARTIAL SPLENECTOMY IN HEREDITARY SPHEROCYTOSIS SO BLOOD LA English DT Article ID SICKLE-CELL-ANEMIA; POSTSPLENECTOMY SEPSIS; PNEUMOCOCCAL SEPSIS; PENICILLIN PROPHYLAXIS; SPECTRIN DEFICIENCY; SPLEEN; INFECTION; CHILDREN; TRANSPLANTATION; EKTACYTOMETRY C1 HOP BICETRE, HEMATOL LAB, F-94270 LE KREMLIN BICETRE, FRANCE. HOP BICETRE, DEPT PEDIAT, F-94270 LE KREMLIN BICETRE, FRANCE. LAWRENCE BERKELEY LAB, BERKELEY, CA 94720 USA. FU NIDDK NIH HHS [DK 26263] NR 47 TC 52 Z9 53 U1 0 U2 0 PU AMER SOC HEMATOLOGY PI WASHINGTON PA 2021 L ST NW, SUITE 900, WASHINGTON, DC 20036 USA SN 0006-4971 EI 1528-0020 J9 BLOOD JI Blood PD APR 15 PY 1993 VL 81 IS 8 BP 2014 EP 2020 PG 7 WC Hematology SC Hematology GA KY005 UT WOS:A1993KY00500006 PM 8471763 ER PT J AU HOLLEBONE, BP ZHENG, Y BRION, CE DAVIDSON, ER FELLER, D AF HOLLEBONE, BP ZHENG, Y BRION, CE DAVIDSON, ER FELLER, D TI VALENCE ELECTRON MOMENTUM DISTRIBUTIONS OF THE HYDROGEN HALIDES .1. COMPARISON OF EMS MEASUREMENTS AND CALCULATIONS USING HARTREE-FOCK LIMIT AND CONFIGURATION-INTERACTION WAVE-FUNCTIONS FOR HYDROGEN-FLUORIDE SO CHEMICAL PHYSICS LA English DT Article ID BINDING-ENERGY SPECTRA; CORRELATED WAVEFUNCTIONS; ORGANIC-MOLECULES; SPECTROSCOPY; ORBITALS; METHANE; HF AB The valence orbital momentum profiles of hydrogen fluoride have been obtained using electron momentum spectroscopy at an impact energy of 1200 eV. The present results show significant differences from earlier measurements (J. Electron Spectry. Relat. Phenom. 21 (1980) 71) for the (3sigma)-1 ionization but are in good agreement for the (1pi)-1 and (2sigma)-1 processes. The measurements are compared with calculations ranging from minimum basis set to highly saturated basis sets essentially at the Hartree-Fock limit and also with numerical Hartree-Fock calculations. The experimental momentum resolution is incorporated into the calculations using the recently developed GW-PG resolution folding method (Chem. Phys. 159 (1992) 347). The significant discrepancy remaining between SCF limit calculations and experiment indicates the importance of electron correlation and relaxation effects in describing the momentum profile corresponding to the removal of the 1pi electron. These effects are investigated using multireference singles and doubles CI calculations of the full ion-neutral overlap distribution and considerable improvement in the agreement between theory and experiment is then achieved. C1 INDIANA UNIV, DEPT CHEM, BLOOMINGTON, IN 47405 USA. PACIFIC NW LAB, CTR MOLEC SCI, RICHLAND, WA 99352 USA. RP HOLLEBONE, BP (reprint author), UNIV BRITISH COLUMBIA, DEPT CHEM, 2036 MAIN MALL, VANCOUVER V6T 1Z1, BC, CANADA. RI Davidson, Ernest/K-9709-2015 OI Davidson, Ernest/0000-0002-3096-480X NR 36 TC 23 Z9 23 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0301-0104 J9 CHEM PHYS JI Chem. Phys. PD APR 15 PY 1993 VL 171 IS 3 BP 303 EP 317 DI 10.1016/0301-0104(93)80201-J PG 15 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA KW166 UT WOS:A1993KW16600002 ER PT J AU LARIMER, FW SOPER, TS AF LARIMER, FW SOPER, TS TI OVERPRODUCTION OF ANABAENA-7120 RIBULOSE-BISPHOSPHATE CARBOXYLASE OXYGENASE IN ESCHERICHIA-COLI SO GENE LA English DT Article DE CHAPERONIN; GROE; TAC PROMOTER; OPERON STRUCTURE; RUBISCO; URF ID RIBULOSE-1,5-BISPHOSPHATE CARBOXYLASE; RHODOSPIRILLUM-RUBRUM; RIBULOSEBISPHOSPHATE CARBOXYLASE; 1,5-BISPHOSPHATE CARBOXYLASE; SMALL SUBUNIT; SEQUENCE; MUTAGENESIS; GENES; SITE; RESOLUTION AB As a prerequisite to protein engineering, we have overexpressed the rbcLS operon of the cyanobacterium Anabaena 7120, in Escherichia coli. The operon encodes the large and small subunits of ribulose-bisphosphate carboxylase/oxygenase (Rubisco). Levels of active enzyme exceed 6% of soluble protein. We noted an apparent third gene, an unidentified open reading frame (URF) referred to here as rbcX, in the 558-bp intergenic space between the large and small subunit encoding genes. The URF, rbcX, has no known function. High-level production of Rubisco activity from the rbc operon in E. coli required simultaneous overproduction of the GroESL chaperonins under a regimen of limited growth, in contrast to more modest conditions which suffice for efficient production of the Anacystis nidulans cyanobacterial Rubisco. Deletion of rbcX or inversion of the rbcL-rbcS order did not enhance expression levels. The recombinant Rubisco, purified to near homogeneity, exhibited functional properties [K(m)(ribulose-P2), k(cat) transition-state-analogue binding stoichiometry/exchange, and specificity factor] essentially identical to those of the enzyme obtained from Anabaena. RP LARIMER, FW (reprint author), OAK RIDGE NATL LAB,DIV BIOL,PROT ENGN PROGRAM,BOX 2009,OAK RIDGE,TN 37831, USA. NR 36 TC 27 Z9 28 U1 2 U2 4 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0378-1119 J9 GENE JI Gene PD APR 15 PY 1993 VL 126 IS 1 BP 85 EP 92 DI 10.1016/0378-1119(93)90593-R PG 8 WC Genetics & Heredity SC Genetics & Heredity GA KX623 UT WOS:A1993KX62300011 PM 8472962 ER PT J AU GAUTESEN, AK AF GAUTESEN, AK TI THE INTERFACE CRACK UNDER COMBINED LOADING - AN EIGENVALUE PROBLEM FOR THE GAP SO INTERNATIONAL JOURNAL OF FRACTURE LA English DT Article ID SHEAR FIELD; CONTACT AB To avoid the difficulty of overlapping material near the crack tips, the tips of the crack are assumed to be closed (the Comninou model). The exact series solution to the problem of the interface crack under combined loading is complicated, and it is difficult to take advantage of the smallness of the left contact zone to obtain simple asymptotic approximations to the quantities of physical interest. Here, the gap is shown to satisfy an eigenvalue problem. The method of matched inner and outer expansions is used to obtain a simple uniform approximation to this quantity. Similar results are obtained for the tangential shift, which satisfies the same differential equation as the gap. The tractions at the interface also satisfy a second order differential equation and simple uniform approximations are obtained for these quantities. C1 IOWA STATE UNIV SCI & TECHNOL,DEPT MATH,AMES,IA 50011. RP GAUTESEN, AK (reprint author), IOWA STATE UNIV SCI & TECHNOL,US DOE,AMES LAB,AMES,IA 50011, USA. NR 17 TC 15 Z9 16 U1 0 U2 0 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0376-9429 J9 INT J FRACTURE JI Int. J. Fract. PD APR 15 PY 1993 VL 60 IS 4 BP 349 EP 361 PG 13 WC Materials Science, Multidisciplinary; Mechanics SC Materials Science; Mechanics GA LK054 UT WOS:A1993LK05400004 ER PT J AU HEBNER, GA HAYS, GN AF HEBNER, GA HAYS, GN TI FISSION-FRAGMENT EXCITED XENON RARE-GAS MIXTURES .1. LASER PARAMETERS OF THE 1.73-MU-M XENON TRANSITION SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID ATOMIC XENON; ELECTROIONIZATION LASER; XE(6P) STATES; XE-LASER; DEACTIVATION; PERFORMANCE; EXCITATION; HE-3-XE; GAIN; AR AB Laser parameters for the 1.73 mum (5d[3/2]1-6p[5/2]2) xenon transition in fission-fragment excited Ar/Xe, He/Ar/Xe, Ne/Ar/Xe, and He/Ne/Ar/Xe gas mixtures are presented. Using a cw F center laser, time resolved small signal gain was probed as a function of total pressure, xenon concentration, pump power, He/Ne/Ar buffer ratio and impurity concentration. Small signal gains of up to 2%/cm were observed for pump rates of 30 W/cm3. Addition of helium and/or neon to the argon buffer increased the width of the time resolved laser gain pulse and reduced the absorption observed under some experimental conditions. Experimentally determined gain scaling laws for several gas mixtures are presented. The measured small signal gain was coupled with the results of laser cavity measurements to calculate the saturation intensity for several gas mixtures. The addition of helium or neon increases the saturation intensity for several gas mixtures. Laser cavity measurements as well as the gain X saturation intensity product indicate that the 1.73 mum power efficiency is approximately 2% for several gas mixtures. RP HEBNER, GA (reprint author), SANDIA NATL LABS,ALBUQUERQUE,NM 87185, USA. NR 52 TC 18 Z9 19 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 APR 15 PY 1993 VL 73 IS 8 BP 3614 EP 3626 DI 10.1063/1.352920 PG 13 WC Physics, Applied SC Physics GA KY567 UT WOS:A1993KY56700005 ER PT J AU HEBNER, GA HAYS, GN AF HEBNER, GA HAYS, GN TI FISSION-FRAGMENT EXCITED XENON RARE-GAS MIXTURES .2. SMALL-SIGNAL GAIN OF THE 2.03-MU-M XENON TRANSITION SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID AR-XE LASER; ELECTRON-BEAM; ATOMIC XENON; ELECTROIONIZATION LASER; XE(6P) STATES; DEACTIVATION; PERFORMANCE; EXCITATION; DISCHARGE; HE-3-XE AB The results of small signal gain measurements of the 2.03 mum (5d[3/2]1-6p[3/2]1) xenon transition in fission-fragment excited Ar/Xe, He/Ar/Xe, Ne/Ar/Xe, and He/Ne/Ar/Xe gas mixtures is presented. Time resolved small signal gain was probed using a cw He/Xe discharge laser as a function of total pressure, xenon concentration, pump power, He/Ne/Ar buffer ratio, and impurity concentration. Small signal gains of up to 6%/cm were observed for pump rates of 15 W/cm3. Addition of helium and/or neon to the argon buffer increased the width of the laser gain and reduced the absorption observed under some experimental conditions. Experimentally determined gain scaling laws for several gas mixtures are presented. RP HEBNER, GA (reprint author), SANDIA NATL LABS,ALBUQUERQUE,NM 87185, USA. NR 42 TC 13 Z9 13 U1 0 U2 0 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 APR 15 PY 1993 VL 73 IS 8 BP 3627 EP 3636 DI 10.1063/1.352921 PG 10 WC Physics, Applied SC Physics GA KY567 UT WOS:A1993KY56700006 ER PT J AU SHIGESATO, Y PAINE, DC HAYNES, TE AF SHIGESATO, Y PAINE, DC HAYNES, TE TI STUDY OF THE EFFECT OF ION-IMPLANTATION ON THE ELECTRICAL AND MICROSTRUCTURAL PROPERTIES OF TIN-DOPED INDIUM OXIDE THIN-FILMS SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID OPTICAL-PROPERTIES; IN2O3 FILMS AB Ion implantation of H-2+ or O+ ions in the range 0-1.7 X 10(15) and 0-1.3 X 10(15)/CM2 , respectively, was used to investigate the effect of implant-induced damage on the electrical properties of Sn-doped In2O3 (ITO) films deposited by electron-beam evaporation on SiO2-coated soda-lime glass substrates. The films were characterized as a function of implant dose using low-temperature Hall effect, resistivity, optical transmissivity, x-ray diffraction, and transmission electron microscopy (TEM). A systematic decrease in both carrier density (n) and Hall mobility (mu) was observed with increasing dose of either implant species. The electronic results were analyzed using charged and neutral impurity scattering models which suggest that the observed changes are due to the degradation of electrically active donor centers and the generation of the neutral scattering centers. The microstructure of the implanted films, as revealed by TEM and x-ray diffraction, is consistent with the presence of significant dynamic recovery during implantation. C1 ASAHI GLASS CO LTD,CTR ADV GLASS R&D,KANAGAWA KU,YOKOHAMA 221,JAPAN. OAK RIDGE NATL LAB,DIV SOLID STATE,OAK RIDGE,TN 37831. RP SHIGESATO, Y (reprint author), BROWN UNIV,DIV ENGN,BOX D,PROVIDENCE,RI 02912, USA. RI Haynes, Tony/P-8932-2015 OI Haynes, Tony/0000-0003-2871-4745 NR 24 TC 98 Z9 98 U1 1 U2 14 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 APR 15 PY 1993 VL 73 IS 8 BP 3805 EP 3811 DI 10.1063/1.352887 PG 7 WC Physics, Applied SC Physics GA KY567 UT WOS:A1993KY56700030 ER PT J AU LUO, L NASTASI, M MAGGIORE, CJ PINIZZOTTO, RF YANG, H NAMAVAR, F AF LUO, L NASTASI, M MAGGIORE, CJ PINIZZOTTO, RF YANG, H NAMAVAR, F TI FORMATION OF METALLIC, CRYSTALLINE NISI2 THIN-FILM ON AMORPHOUS SIO2/SI SO JOURNAL OF APPLIED PHYSICS LA English DT Note ID IMPLANTATION; OXYGEN; COSI2; SI AB Thin metallic, oriented crystalline NiSi2 filMs that are suitable for additional epitaxial growth have been formed on amorphoUS SiO2 layers on Si substrates. The orientation of the Si substrate is maintained in the NiSi2 film as if the SiO2 is not present. This was achieved by combining the separation by implantation of oxygen process and e-beam evaporation techniques. The results are comparable with NiSi2 films formed directly on Si. This technique should, in general, be applicable to other silicides that have been epitaxially grown on Si. C1 N TEXAS STATE UNIV,CTR MAT CHARACTERIZAT,DENTON,TX 76203. SPIRE CORP,BEDFORD,MA 01730. RP LUO, L (reprint author), LOS ALAMOS NATL LAB,CTR MAT SCI,LOS ALAMOS,NM 87545, USA. NR 13 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 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD APR 15 PY 1993 VL 73 IS 8 BP 4107 EP 4109 DI 10.1063/1.352843 PG 3 WC Physics, Applied SC Physics GA KY567 UT WOS:A1993KY56700088 ER PT J AU HUNT, RD YUSTEIN, JT ANDREWS, L AF HUNT, RD YUSTEIN, JT ANDREWS, L TI MATRIX INFRARED-SPECTRA OF NUN FORMED BY THE INSERTION OF URANIUM ATOMS INTO MOLECULAR NITROGEN SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID ALUMINUM AB Pulsed-laser ablated uranium atoms were codeposited with N-14(2)(N-15(2)) and excess Ar at 12 K. The Fourier transform infrared (FTIR) spectrum revealed a single product, UN2, which exhibited a v3 absorption at 1051.0 cm-1. Ultraviolet (UV) photolysis increased the yield of UN2 by threefold and showed that electronic excitation facilitated the insertion reaction. N2 perturbed UN2 bands at 1041.3 and 1031.5 cm-1 grew sharply during matrix annealings. In (NN)-N-14-N-15 experiments the v1 and v3 modes of (NUN)-N-14-N-15 were observed at 987.2 and 1040.7 cm-1, respectively; FG matrix calculations were performed to determine F(r) = 8.27 mdyn/angstrom and F(rr) = 0.12 mdyn/angstrom and to estimate the IR-inactive v1 modes of (UN2)-N-14 and (UN2)-N-15 at 1008.3 and 985.7 cm-1, respectively. Energetic considerations suggest that the U+N2 insertion reaction has little exothermicity and that the activation energy for this reaction may be provided by hypothermal uranium atoms. C1 UNIV VIRGINIA,DEPT PHYS,CHARLOTTESVILLE,VA 22901. RP HUNT, RD (reprint author), OAK RIDGE NATL LAB,DIV CHEM TECHNOL,OAK RIDGE,TN 37831, USA. NR 23 TC 82 Z9 82 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 APR 15 PY 1993 VL 98 IS 8 BP 6070 EP 6074 DI 10.1063/1.464845 PG 5 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA KX946 UT WOS:A1993KX94600005 ER PT J AU HU, TA CHAPPELL, EL SHARPE, SW AF HU, TA CHAPPELL, EL SHARPE, SW TI INFRARED, DIODE-LASER SPECTROSCOPY OF THE AR-N2O COMPLEX - OBSERVATION OF THE INTERMOLECULAR BENDING MODE IN COMBINATION WITH THE HIGHEST FREQUENCY INTRAMOLECULAR STRETCHING MODE SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID TRANSFORM MICROWAVE SPECTROSCOPY; PULSED MOLECULAR-BEAM; ABSORPTION SPECTROSCOPY; VANDERWAALS COMPLEX; SPECTROMETRY; SPECTRUM; REGION AB Rotationally resolved vibrational spectra consisting of a-type transitions have been observed for the low-frequency, intermolecular bending mode in combination with the highest frequency, intramolecular stretching mode of Ar-N2O. Analysis of the spectral data places the origin of the combination band at 2256.1 cm-1 while the origin of the intramolecular stretching fundamental is at 2223.9 cm-1. The difference between these two origins is approximately 32.2 cm-1 and agrees well with our calculated frequency of 31.5 cm-1 for the intermolecular bending mode, which was obtained by analysis of the centrifugal distortion constants. In addition, argon-nitrous oxide exhibits an anomalously large inertial defect of 10.96 amu angstrom2 in the combination state. This indicates a breakdown in the assumption of separation between vibration and rotation. While much of the inertial defect in the ground state can be accounted for by including Coriolis interactions, that occurring in the combination state is only partially accounted for by a similar analysis. Small, but significant changes, are observed in both the radial and angular parameters for Ar-N2O when going from the ground to the combination state, indicating large amplitude motion. The combination band is approximately 200 times less intense than the high-frequency, stretching fundamental of Ar-N2O. In addition, over 400 new rovibrational transitions are assigned to the previously served 1(0)1 intramolecular stretching fundamental of the complex, and the subsequent rotational analysis is found to be in close agreement with earlier studies. Data were taken on a newly built, rapid-scan, diode laser spectrometer that incorporates a 12 cm X 200 mum pulsed slit-expansion nozzle. RP HU, TA (reprint author), PACIFIC NW LAB, MOLEC SCI RES CTR, RICHLAND, WA 99352 USA. NR 28 TC 49 Z9 50 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 APR 15 PY 1993 VL 98 IS 8 BP 6162 EP 6169 DI 10.1063/1.465101 PG 8 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA KX946 UT WOS:A1993KX94600015 ER PT J AU KHAN, FA KREUTZ, TG FLYNN, GW WESTON, RE AF KHAN, FA KREUTZ, TG FLYNN, GW WESTON, RE TI TRANSLATIONALLY AND ROTATIONALLY RESOLVED EXCITATION OF CO2(00(0)2 BY COLLISIONS WITH HOT HYDROGEN-ATOMS SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID DIODE-LASER SPECTROSCOPY; PRODUCT STATE DISTRIBUTION; ENERGY-TRANSFER; REACTION DYNAMICS; CARBON-DIOXIDE; H+CO2 REACTION; CO2; OH; PHOTOLYSIS; COMPLEXES AB Time domain tunable diode laser absorption spectroscopy has been used to measure rotationally resolved transient absorption line shapes and nascent rotational populations for CO2 molecules excited into the (00(0)2) vibrational state by collisions with translationally hot hydrogen atoms. The 00(0)2 rotational population distribution and rotationally resolved linewidths are remarkably similar to those previously obtained for 00(0)1. Within the context of a simple physical model used to interpret the data, the similar rotational distributions and translational recoils for 00(0)1 and 00(0)2 suggest that these two states are excited by similar collision trajectories, wherein asymmetric stretching excitation is optimized when H strikes near the end of the O-C-O molecule. The magnitude of population scattered into 00(0)2 is approximately 21 times smaller than that scattered into 00(0)1. C1 COLUMBIA UNIV,COLUMBIA RADIAT LAB,NEW YORK,NY 10027. COLUMBIA UNIV,DEPT CHEM,NEW YORK,NY 10027. BROOKHAVEN NATL LAB,DEPT CHEM,UPTON,NY 11973. NR 42 TC 8 Z9 8 U1 0 U2 2 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 APR 15 PY 1993 VL 98 IS 8 BP 6183 EP 6189 DI 10.1063/1.464833 PG 7 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA KX946 UT WOS:A1993KX94600018 ER PT J AU TANG, J AF TANG, J TI EFFECTS OF A FLUCTUATING ELECTRONIC COUPLING MATRIX ELEMENT ON ELECTRON-TRANSFER RATE SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID CLASSICAL SOLVENT DYNAMICS; POLAR-SOLVENTS; DIELECTRIC FRICTION; OHMIC DISSIPATION; 2-STATE SYSTEM; MOLECULES; SOLVATION; STATES AB The effects of a fluctuating electronic coupling matrix element on an electron transfer process are examined theoretically. An analytical expression for the electron transfer rate constant was derived using the spin-boson model. In the limit of long correlation time (tau(v)) for the fluctuation, our results are identical to the Marcus expression for the static coupling. The electron transfer rate in the intermediate range of tau(v), however, can be either enhanced or reduced, depending on the free energy gap and the reorganization energy. In the limit of very short tau(v) the electron transfer rate decreases with tau(v) and depends only on tau(v) and the coupling matrix element. RP TANG, J (reprint author), ARGONNE NATL LAB,DIV CHEM,ARGONNE,IL 60439, USA. RI Tang, Jau/D-8382-2012 OI Tang, Jau/0000-0003-2078-1513 NR 47 TC 54 Z9 54 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 APR 15 PY 1993 VL 98 IS 8 BP 6263 EP 6266 DI 10.1063/1.464820 PG 4 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA KX946 UT WOS:A1993KX94600027 ER PT J AU WILLAIME, F FALICOV, LM AF WILLAIME, F FALICOV, LM TI SPIN-DENSITY WAVE, CHARGE-DENSITY WAVE, AND POLARIZABILITIES OF C-60 IN THE PARISER-PARR-POPLE MODEL SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID ABINITIO CALCULATIONS; ELECTRONIC-STRUCTURE; DOPED FULLERENES; ICOSAHEDRAL C-60; C60; SUPERCONDUCTIVITY; BUCKMINSTERFULLERENE; MOLECULE; CLUSTERS; CARBON AB The Pariser-Parr-Pople Hamiltonian is investigated on a single C60 molecule in the Hartree-Fock approximation. The effect of on-site and two-site electron-electron interactions on the stability of states other than the normal paramagnetic state is studied. In particular (i) a spin-density wave state, with a structure similar to that of the classical ground state of the antiferromagnetic Heisenberg Hamiltonian; and (ii) a charge density wave state which occurs for weakly screened two-site interactions. Linear and nonlinear optical properties are also calculated. With the finite field method and the Moller-Plesset correction in second order, a linear polarizability of 325.5 a. u. and a second hyperpolarizability of 5.87 X 10(-36) esu are found. C1 CTR ETUDES SACLAY,RECH MET PHYS SECT,F-91191 GIF SUR YVETTE,FRANCE. LAWRENCE BERKELEY LAB,DIV MAT SCI,BERKELEY,CA 94720. RP WILLAIME, F (reprint author), UNIV CALIF BERKELEY,DEPT PHYS,BERKELEY,CA 94720, USA. NR 56 TC 28 Z9 28 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 APR 15 PY 1993 VL 98 IS 8 BP 6369 EP 6376 DI 10.1063/1.464830 PG 8 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA KX946 UT WOS:A1993KX94600038 ER PT J AU MCCARTHY, MI HESS, AC HARRISON, NM SAUNDERS, VR AF MCCARTHY, MI HESS, AC HARRISON, NM SAUNDERS, VR TI A STUDY OF THE ENERGETICS OF THE CL2/MGO(001) INTERFACE USING CORRELATION CORRECTED PERIODIC HARTREE-FOCK THEORY SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID CORRELATION-ENERGY; ABINITIO AB The energetics of the Cl2/MgO(001) interface were investigated using the ab initio periodic Hartree-Fock (PHF) method and local density functional correlation corrections to PHF theory, as implemented in the program CRYSTAL92. Estimates of the correlation corrected PHF energies are made by post-SCF evaluations of three gradient corrected functionals. The correlation energy is calculated from the fully converged ground state PHF charge density and added to the PHF total energy. This is the first study of interfacial energetics using the correlation corrected PHF theory. PHF and correlation corrected molecule/surface binding energies are reported for seven orientations of the adsorbate with respect to the surface plane. Three of the configurations align the intramolecular axes along the surface normal and the remaining geometries arrange the molecules heat-to-tail, parallel to the surface plane. The most favorable interaction occurs when chlorine approaches a surface oxygen along the normal direction. This site preference is consistent with a classical electrostatic description of the physisorption process. The binding energy increases with decreasing surface coverage. At the most dilute coverage studied (1:8) the PHF binding energy was 4.1 kcal/mol and the correlation corrected binding energies ranged from 9.2 to 10.3 kcal/mol. All three functionals tended to increase the molecule/surface attractions, shorten the molecule/surface equilibrium distance, increase the curvature of the molecule/surface potential energy surface near equilibrium, and reduce the molecule/molecule repulsions. C1 SERC, DARESBURY LAB, WARRINGTON WA4 4AD, CHESHIRE, ENGLAND. RP MCCARTHY, MI (reprint author), PACIFIC NW LAB, MAT SCI RES CTR, RICHLAND, WA 99352 USA. RI Harrison, Nicholas/H-3198-2013 OI Harrison, Nicholas/0000-0001-7498-8144 NR 19 TC 26 Z9 26 U1 0 U2 0 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 APR 15 PY 1993 VL 98 IS 8 BP 6387 EP 6391 DI 10.1063/1.464835 PG 5 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA KX946 UT WOS:A1993KX94600040 ER PT J AU MYATT, EA SOLOMON, A STEVENS, FJ AF MYATT, EA SOLOMON, A STEVENS, FJ TI AGGREGATION OF IMMUNOGLOBULIN LIGHT-CHAINS SO JOURNAL OF IMMUNOLOGY LA English DT Meeting Abstract C1 ARGONNE NATL LAB,ARGONNE,IL 60439. UNIV TENNESSEE,KNOXVILLE,TN 37996. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER ASSOC IMMUNOLOGISTS PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814 SN 0022-1767 J9 J IMMUNOL JI J. Immunol. PD APR 15 PY 1993 VL 150 IS 8 BP A152 EP A152 PN 2 PG 1 WC Immunology SC Immunology GA KX956 UT WOS:A1993KX95600874 ER PT J AU POPP, DM POPP, RA AF POPP, DM POPP, RA TI LYMPHOCYTE PERTURBATIONS IN B10.F MICE CARRYING A CONGENITALLY ACQUIRED ECOTROPIC RETROVIRUS SO JOURNAL OF IMMUNOLOGY LA English DT Meeting Abstract C1 ORNL,OAK RIDGE,TN 37831. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER ASSOC IMMUNOLOGISTS PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814 SN 0022-1767 J9 J IMMUNOL JI J. Immunol. PD APR 15 PY 1993 VL 150 IS 8 BP A77 EP A77 PN 2 PG 1 WC Immunology SC Immunology GA KX956 UT WOS:A1993KX95600438 ER PT J AU YANG, MY POPP, DM POPP, RA AF YANG, MY POPP, DM POPP, RA TI FLOW CYTOMETRIC IDENTIFICATION OF CELLULAR MULV EXPRESSION ON LYMPHOID-CELLS FROM ONE-MONTH-OLD-B10.F MICE SO JOURNAL OF IMMUNOLOGY LA English DT Meeting Abstract C1 UNIV TENNESSEE,OAK RIDGE GRAD SCH BIOMED SCI,OAK RIDGE,TN 37831. ORNL,DIV BIOL,OAK RIDGE,TN 37831. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER ASSOC IMMUNOLOGISTS PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814 SN 0022-1767 J9 J IMMUNOL JI J. Immunol. PD APR 15 PY 1993 VL 150 IS 8 BP A159 EP A159 PN 2 PG 1 WC Immunology SC Immunology GA KX956 UT WOS:A1993KX95600912 ER PT J AU KNIBLOE, JR WRIGHT, RN TRYBUS, CL SIKKA, VK AF KNIBLOE, JR WRIGHT, RN TRYBUS, CL SIKKA, VK TI MICROSTRUCTURE AND MECHANICAL-PROPERTIES OF FE3AL ALLOYS WITH CHROMIUM SO JOURNAL OF MATERIALS SCIENCE LA English DT Article ID ROOM-TEMPERATURE DUCTILITY; AL-ALLOYS; FEAL; EMBRITTLEMENT; ENVIRONMENT; B2 AB Alloys based on Fe3Al have an equilibrium DO3 Structure at low temperatures and transform to a B2 structure above about 550-degrees-C. The influence of different rates of quenching from the B2 region to room temperature and of subsequent heat treatments on the microstructure and mechanical properties of powder metallurgy (P/M) alloys with two different chromium contents have been examined. Optimizing the processing to maximize the amount of B2 order, without eliminating dislocations that enhance both strength and ductility, yields room-temperature ductility approaching 20%, although the fracture mode is primarily brittle cleavage. The B2 structure generally has lower flow stress than the DO3 structure because of its lower strain-hardening rate, although B2 order actually has higher yield strength when the structure is free of dislocations. Increasing the chromium content from 2% to 5% has little effect on ductility, although the 2% Cr alloys generally have higher yield strengths and larger order parameters. C1 OAK RIDGE NATL LAB,OAK RIDGE,TN. RP KNIBLOE, JR (reprint author), IDAHO NATL ENGN LAB,IDAHO FALLS,ID 83415, USA. NR 22 TC 24 Z9 25 U1 1 U2 4 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 APR 15 PY 1993 VL 28 IS 8 BP 2040 EP 2048 DI 10.1007/BF00367560 PG 9 WC Materials Science, Multidisciplinary SC Materials Science GA KZ348 UT WOS:A1993KZ34800006 ER PT J AU SHEU, C DAUSKARDT, RH DEJONGHE, L AF SHEU, C DAUSKARDT, RH DEJONGHE, L TI TOUGHNESS AND FATIGUE OF ENCAPSULATION-PROCESSED SILICON-CARBIDE POLYMER MATRIX PARTICULATE COMPOSITES SO JOURNAL OF MATERIALS SCIENCE LA English DT Article ID ALUMINUM-ALLOY COMPOSITES; CRACK-PROPAGATION; FRACTURE-TOUGHNESS; BEHAVIOR; GROWTH; FILLER; STRESS; SIZE AB A new process for composite fabrication was developed which improves distribution of the particulate reinforcing phase by polymer encapsulation of the particulate prior to consolidation. The effect of such processing on the fatigue-crack propagation and fracture toughness behaviour of particulate thermoplastic composites was investigated. Composites of several particulate size ranges were fabricated into disc-shaped, compact tension specimens and tested under cyclic and monotonic loading conditions. For comparison, a composite was also fabricated using a standard casting technique. The observed fatigue-crack growth rates spanned three orders of magnitude (10(-11) to 10(-9) m per cycle) over an applied stress intensity range, DELTAK, of 0.3 to 1.1 M Pa m1/2. The measured fracture toughness values ranged from 0.69 to 2.95 M Pa m1/2. Comparison of the two processing techniques indicated that encapsulation processing increased the fracture toughness of the composite by approximately 33%; however, the fatigue-crack growth behaviour was unaffected. In addition, a trend of increasing crack growth resistance (toughness) with increasing reinforcement particle size was observed. These results are discussed in the light of crack shielding and bridging models for composite toughening. C1 UNIV CALIF BERKELEY,DEPT MAT SCI & MINERAL ENGN,BERKELEY,CA 94720. RP SHEU, C (reprint author), LAWRENCE BERKELEY LAB,DIV MAT SCI,BERKELEY,CA 94720, USA. NR 36 TC 3 Z9 3 U1 0 U2 1 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 APR 15 PY 1993 VL 28 IS 8 BP 2196 EP 2206 DI 10.1007/BF00367584 PG 11 WC Materials Science, Multidisciplinary SC Materials Science GA KZ348 UT WOS:A1993KZ34800030 ER PT J AU HSUEH, CH FERBER, MK WERESZCZAK, AA AF HSUEH, CH FERBER, MK WERESZCZAK, AA TI THE RELATIVE RESIDUAL FIBER DISPLACEMENT AFTER INDENTATION LOADING AND UNLOADING OF FIBER-REINFORCED CERAMIC COMPOSITES SO JOURNAL OF MATERIALS SCIENCE LA English DT Article ID PULL-OUT STRESSES; FIBER AB The interfacial properties of fibre-reinforced ceramic composites have been evaluated by using the indentation technique. The ratio of the residual fibre displacement after complete unloading to the fibre displacement at peak loading is examined. Assuming a constant interfacial shear stress at an unbonded interface, this ratio is 0.5. However, deviation of this ratio from 0.5 is always obtained from experimental results. Both Poisson's effect and the existence of the residual axial stress have been proposed to explain this deviation. A methodology is presented in this study to classify conditions for which either Poisson's effect or the residual axial stress dominates this deviation. The application of this methodology to Nicalon fibre-reinforced lithium aluminosilicate glass-ceramic is also illustrated. RP HSUEH, CH (reprint author), OAK RIDGE NATL LAB,DIV MET & CERAM,OAK RIDGE,TN 37831, USA. RI Hsueh, Chun-Hway/G-1345-2011; Wereszczak, Andrew/I-7310-2016 OI Wereszczak, Andrew/0000-0002-8344-092X NR 11 TC 7 Z9 7 U1 0 U2 2 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 APR 15 PY 1993 VL 28 IS 8 BP 2227 EP 2232 DI 10.1007/BF00367588 PG 6 WC Materials Science, Multidisciplinary SC Materials Science GA KZ348 UT WOS:A1993KZ34800034 ER PT J AU MAUPIN, HE RAWERS, JC AF MAUPIN, HE RAWERS, JC TI METAL INTERMETALLIC COMPOSITES FORMED BY REACTION-SINTERING ELEMENTAL POWDERS SO JOURNAL OF MATERIALS SCIENCE LETTERS LA English DT Article ID COMBUSTION RP MAUPIN, HE (reprint author), US BUR MINES,ALBANY RES CTR,ALBANY,OR 97321, USA. NR 9 TC 15 Z9 15 U1 1 U2 3 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 APR 15 PY 1993 VL 12 IS 8 BP 540 EP 541 PG 2 WC Materials Science, Multidisciplinary SC Materials Science GA KZ351 UT WOS:A1993KZ35100006 ER PT J AU STICHTERNATH, A SCHWEITZERSTENNER, R DREYBRODT, W MAK, RSW LI, XY SPARKS, LD SHELNUTT, JA MEDFORTH, CJ SMITH, KM AF STICHTERNATH, A SCHWEITZERSTENNER, R DREYBRODT, W MAK, RSW LI, XY SPARKS, LD SHELNUTT, JA MEDFORTH, CJ SMITH, KM TI MACROCYCLE AND SUBSTITUENT VIBRATIONAL-MODES OF NONPLANAR NICKEL(II) OCTAETHYLTETRAPHENYLPORPHYRIN FROM ITS RESONANCE RAMAN, NEAR-INFRARED-EXCITED FT RAMAN, AND FT-IR SPECTRA AND DEUTERIUM-ISOTOPE SHIFTS SO JOURNAL OF PHYSICAL CHEMISTRY LA English DT Article ID PORPHYRIN FORCE-FIELD; EXCITATION PROFILES; DEPOLARIZATION DISPERSION; ASYMMETRIC PERTURBATIONS; CYTOCHROME-C; FUNDAMENTALS; OCTAETHYLPORPHYRIN; METALLOPORPHYRINS AB We have employed Raman dispersion, FT Raman, and FT-IR spectroscopy to identify a large number of resonance Raman lines of Ni(II) octaethyltetraphenylporphyrin dissolved in CS2. The Raman depolarization dispersion technique was used to derive the symmetry of the normal modes giving rise to the observed Raman lines. By combining this information and the already available normal coordinates of Ni(II) tetraphenylporphyrin and Ni(II) octaethylporphyrin, many of the Raman-active modes of the macrocycle could be assigned. Some resonance-enhanced Raman lines were found to arise from vibrations of the ethyl and phenyl substituents. They were identified by comparing resonance Raman, FT Raman, and FT infrared spectra of the Ni(II) octaethyltetraphenylporphyrin and its d20 isotopomer. All Raman lines normally referred to as core-size markers are found to be significantly shifted to lower frequencies with respect to their positions in Ni(II) octaethylporphyrin, in accordance with earlier findings (Shelnutt et al., J. Am. Chem. Soc. 113, 4077, 1991). This suggests that the molecule is in a highly nonplanar conformation. This notion is further corroborated by the strong dispersion of the depolarization ratio observed for nearly all A1g and A2g modes of the macrocycle. C1 UNIV BREMEN,INST EXPTL PHYS,W-2800 BREMEN 33,GERMANY. HONG KONG UNIV SCI & TECHNOL,DEPT CHEM,HONG KONG,HONG KONG. UNIV CALIF DAVIS,DEPT CHEM,DAVIS,CA 95616. SANDIA NATL LABS,DEPT FUEL SCI 6211,ALBUQUERQUE,NM 87185. UNIV NEW MEXICO,DEPT CHEM,ALBUQUERQUE,NM 87131. RI Shelnutt, John/A-9987-2009; 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; Medforth, Craig/0000-0003-3046-4909; Smith, Kevin/0000-0002-6736-4779 NR 30 TC 40 Z9 40 U1 0 U2 2 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0022-3654 J9 J PHYS CHEM-US JI J. Phys. Chem. PD APR 15 PY 1993 VL 97 IS 15 BP 3701 EP 3708 DI 10.1021/j100117a012 PG 8 WC Chemistry, Physical SC Chemistry GA KX596 UT WOS:A1993KX59600012 ER PT J AU LIU, AD LOFFREDO, DM TRIFUNAC, AD AF LIU, AD LOFFREDO, DM TRIFUNAC, AD TI PHOTOIONIZATION AND ENSUING ION MOLECULE REACTIONS OF POLYCYCLIC AROMATIC-HYDROCARBONS IN ALKANE AND ALCOHOL-SOLUTIONS SO JOURNAL OF PHYSICAL CHEMISTRY LA English DT Article ID GEMINATE RECOMBINATION; 2-PHOTON IONIZATION; PHOTO-IONIZATION; RADICAL CATIONS; FLUORESCENCE; LIQUIDS; N,N,N',N'-TETRAMETHYL-PARA-PHENYLENEDIAMINE; CONDUCTIVITY; CYCLOHEXANE; ANTHRACENE AB A common reaction pathway involving ion-molecule reactions of excited ions is indicated for a series of polycyclic aromatic hydrocarbons photoionized using intense pulsed excimer lasers (248 and 308 nm). The overall yields of free electrons and free aromatic radical cations created by two-photon ionization are measured by laser flash photolysis in cyclohexane and in 2-propanol solutions. The electron yields increase with increasing photon energies and photon flux, but the yield of radical cation is found to decrease with increasing photon flux. Photoproducts derived from aryl and solvent radicals are observed and quantified by GC and GC-MS, and their yields increase with increasing photon energy and photon flux. The diminished yield of radical ions at higher photon flux suggests an alternate higher energy reaction pathway for the radical cation. While aryl radical cations are relatively unreactive, an excited aryl radical cation could protonate the surrounding solvent, leading to aryl radical formation (AH.+* + RH --> A. + RH2+). Solvent radical formation would then result from hydrogen atom abstraction by aryl radicals. Product studies support this ion-molecule reaction pathway and exclude alternate mechanisms involving neutral excited state homolysis. C1 ARGONNE NATL LAB,DIV CHEM,ARGONNE,IL 60439. NR 27 TC 19 Z9 20 U1 1 U2 3 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0022-3654 J9 J PHYS CHEM-US JI J. Phys. Chem. PD APR 15 PY 1993 VL 97 IS 15 BP 3791 EP 3799 DI 10.1021/j100117a027 PG 9 WC Chemistry, Physical SC Chemistry GA KX596 UT WOS:A1993KX59600027 ER PT J AU GRIMM, FA HUNTLEY, DR AF GRIMM, FA HUNTLEY, DR TI THEORETICAL-STUDY OF THE BINDING-ENERGY AND BONDING OF BENZENE TO THE NI (111), (100), AND (110) SURFACES SO JOURNAL OF PHYSICAL CHEMISTRY LA English DT Article ID MOLECULAR-ORBITAL THEORY; LATERAL INTERACTIONS; ORGANIC-MOLECULES; ADSORPTION; NI(111); NI(100); HYDROCARBONS; PD(110); NICKEL; STATE AB The atomic superposition electron delocalization molecular orbital (ASED-MO) method has been applied to a study of the favored bonding sites for benzene adsorbed on the (111), (100), and (110) crystal faces of nickel metal. The different faces were represented in the calculations by clusters, which contained 30 nickel atoms. By using the same size clusters and parameters, it was possible to compare the results among the three different crystal faces. The most favored (highest binding energy) sites for the benzene ring parallel to the surface were found to be the highest coordination site for the (111) and (100) planes and the atop site for the (110) plane. These results are compared with both experimental and other theoretical calculations on these crystal planes. In addition, the bonding of the benzene to the Ni surfaces has been investigated by using ''bonding plots'', which are graphical representations of the Mulliken population matrix. By use of these bonding plots, a picture of the bonding of the benzene to the nickel surface is developed and an explanation for the increase of the binding energy with increased cluster size is discussed. C1 OAK RIDGE NATL LAB,OAK RIDGE,TN 37831. UNIV TENNESSEE,KNOXVILLE,TN 37996. NR 28 TC 18 Z9 18 U1 0 U2 4 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0022-3654 J9 J PHYS CHEM-US JI J. Phys. Chem. PD APR 15 PY 1993 VL 97 IS 15 BP 3800 EP 3805 DI 10.1021/j100117a028 PG 6 WC Chemistry, Physical SC Chemistry GA KX596 UT WOS:A1993KX59600028 ER PT J AU FITZMAURICE, DJ ESCHLE, M FREI, H MOSER, J AF FITZMAURICE, DJ ESCHLE, M FREI, H MOSER, J TI TIME-RESOLVED RISE OF I-2(-) UPON OXIDATION OF IODIDE AT AQUEOUS TIO2 COLLOID SO JOURNAL OF PHYSICAL CHEMISTRY LA English DT Article ID INTERFACIAL ELECTRON-TRANSFER; REFLECTANCE FLASH-PHOTOLYSIS; SEMICONDUCTOR DISPERSIONS; TITANIUM-DIOXIDE; CHARGE-TRANSFER; LIGHT; DYNAMICS; SENSITIZATION; SYSTEMS; WATER AB The rise of the one-electron oxidation intermediate I2- formed upon band-gap excitation of bare TiO2 colloidal particles in aqueous iodide solution has been resolved for the first time. These measurements are based on a very sensitive transient absorption technique that allows monitoring of I2- at iodide concentrations as low as 10(-4) M. The linear dependence of the pseudo-first-order rise constant on iodide concentration (slope = (7.9 +/- 1.2) X 10(9) L mol-1 s-1) suggests that the observed step reflects the reaction of surface-adsorbed I atoms with iodide from the surrounding solution phase. The adsorbed I atoms are formed by the reaction of surface-adsorbed iodide with valence band holes with in the 5-ns duration of the 355 band-gap excitation pulse. Analysis of the decay kinetics of I2- and measurement of the concurrent I3- yield revealed that interparticle reduction by trapped conduction band electrons is the main decay path of I2-. These results are compared with a previous time-resolved study of iodide photooxidation at dye-sensitized TiO2 colloids. C1 LAWRENCE BERKELEY LAB,CHEM BIODYNAM LAB,BERKELEY,CA 94720. ECOLE POLYTECH FED LAUSANNE,INST CHIM PHYS,CH-1015 LAUSANNE,SWITZERLAND. RI Moser, Jacques/B-3593-2008 OI Moser, Jacques/0000-0003-0747-4666 NR 42 TC 55 Z9 55 U1 1 U2 5 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0022-3654 J9 J PHYS CHEM-US JI J. Phys. Chem. PD APR 15 PY 1993 VL 97 IS 15 BP 3806 EP 3812 DI 10.1021/j100117a029 PG 7 WC Chemistry, Physical SC Chemistry GA KX596 UT WOS:A1993KX59600029 ER PT J AU ROSEN, ME RUCKER, SP SCHMIDT, C PINES, A AF ROSEN, ME RUCKER, SP SCHMIDT, C PINES, A TI 2-DIMENSIONAL PROTON NMR-STUDIES OF THE CONFORMATIONS AND ORIENTATIONS OF N-ALKANES IN A LIQUID-CRYSTAL SOLVENT SO JOURNAL OF PHYSICAL CHEMISTRY LA English DT Article ID ALKYL CHAINS; FLEXIBLE SOLUTES; NEMATIC SOLVENT; UNIAXIAL FIELD; ORDER; MOLECULES; SHAPE; HEXANE; SIZE AB Magnetic dipole couplings between pairs of protons in a series of n-alkanes (hexane through decane) dissolved in a nematic liquid crystal were measured by two-dimensional NMR spectroscopy. The dependence of dipole couplings on the distance between pairs of protons and on the orientation of the molecule with respect to the applied magnetic field make them a potentially rich source of information about molecular conformation and orientation. Interpretation of the dipole couplings, however, is complicated by the fact that the measured couplings are averaged over all molecular conformations and orientations sampled by the molecule. Thus, the couplings do not directly provide internuclear distances and orientations, but instead provide constraints on the time-averaged conformations and orientations of the n-alkane molecules that can be used as a rigorous test of models for intermolecular interactions in liquid crystals. Three models for solute-liquid crystal interactions were examined; the model proposed by Photinos et al.1 was found to be superior to the others in describing this system. The results of the modeling, including order parameters and conformer probabilities for the alkanes, are discussed and compared to n-alkanes in the liquid state. C1 UNIV CALIF BERKELEY,DEPT CHEM,BERKELEY,CA 94720. LAWRENCE BERKELEY LAB,DIV MAT & CHEM SCI,BERKELEY,CA 94720. RI Schmidt, Claudia/B-2968-2012 OI Schmidt, Claudia/0000-0003-3179-9997 NR 20 TC 41 Z9 42 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0022-3654 J9 J PHYS CHEM-US JI J. Phys. Chem. PD APR 15 PY 1993 VL 97 IS 15 BP 3858 EP 3866 DI 10.1021/j100117a037 PG 9 WC Chemistry, Physical SC Chemistry GA KX596 UT WOS:A1993KX59600037 ER PT J AU MILLER, DG ALBRIGHT, JG MATHEW, R LEE, CM RARD, JA EPPSTEIN, LB AF MILLER, DG ALBRIGHT, JG MATHEW, R LEE, CM RARD, JA EPPSTEIN, LB TI ISOTHERMAL DIFFUSION-COEFFICIENTS OF NACL-MGCL2-H2O AT 25-DEGREES-C .5. SOLUTE CONCENTRATION RATIO OF 1/1 AND SOME RAYLEIGH RESULTS SO JOURNAL OF PHYSICAL CHEMISTRY LA English DT Article ID MULTICOMPONENT DIFFUSION; MGCL2 CONCENTRATIONS; TERNARY DIFFUSION; AQUEOUS MIXTURES; WIDE-RANGE; 25-DEGREES-C; SYSTEMS; NACL; BINARY; INTERFEROMETRY AB Isothermal interdiffusion coefficients have been obtained by Gouy interferometry for the ternary system NaCl-MgCl2-H2O at 25.00-degrees-C and a 1:1 mole ratio of NaCl to MgCl2. Data are reported for total molar concentrations of 0.5, 1.0, 2.0, 3.0, and 3.72 M. Diffusion coefficients at mole ratios of 1:1 (0.5 and 1.0 M), 1:3 (1.0 and 3.0 M), and 3:1 (1.0 M) were also obtained by Rayleigh interferometry during the corresponding Gouy experiments by switching the two optical systems back and forth. As expected, good agreement is found between Gouy and Rayleigh results. Diffusion coefficients at the 1:1 ratio are intermediate between the results for 1:3 and 3:1 ratios, with D12 becoming large with increasing concentration but always less than D11 and D22, and with D11 and D22 crossing at 2.8 M. Densities were measured for all solutions. Rayleigh experimental and data analysis techniques are described. C1 TEXAS CHRISTIAN UNIV,DEPT CHEM,FT WORTH,TX 76129. PRC ENVIRONM MANAGEMENT INC,DALLAS,TX 75201. NEW BRUNSWICK SCI CORP,EDISON,NJ 08818. RP MILLER, DG (reprint author), LAWRENCE LIVERMORE NATL LAB,DEPT CHEM & MAT SCI,LIVERMORE,CA 94550, USA. NR 84 TC 39 Z9 39 U1 1 U2 5 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0022-3654 J9 J PHYS CHEM-US JI J. Phys. Chem. PD APR 15 PY 1993 VL 97 IS 15 BP 3885 EP 3899 DI 10.1021/j100117a040 PG 15 WC Chemistry, Physical SC Chemistry GA KX596 UT WOS:A1993KX59600040 ER PT J AU FERRIERI, RA SHARMA, RB WOLF, AP RACK, EP AF FERRIERI, RA SHARMA, RB WOLF, AP RACK, EP TI STEREOCHEMICAL CONSEQUENCES OF HALOGEN ATOM SUBSTITUTION .3. RECOIL F-18 FOR-X (X = F, CL) REACTIONS IN GASEOUS DIASTEREOMERIC 2,3-DIHALOBUTANES SO JOURNAL OF PHYSICAL CHEMISTRY LA English DT Article ID HIGH-ENERGY CHLORINE; GAS-PHASE; WALDEN INVERSION AB Studies have been carried out in the gas phase that address the stereochemical consequences of hot F-18-for-X (X = F, Cl) substitution in (2S,3R)-meso- and (2S,3S)-dl-difluorobutane, (2S,3R)-dl- and (2S,3S)-dl-chlorofluorobutane, and (2S,3R)-meso- and (2S,3S)-dl-dichlorobutane. Two features of reaction are revealed from this work when the results are compared to those of earlier work on Cl-38-for-X (X = F, Cl) substitution in the same systems. First, the overall reaction efficiency is sensitive to the size and mass of the leaving group, but only when the hot atom itself is relatively small. Secondly, steric hindrance to attack at the asymmetric carbon site is not important when reactions involve small hot atoms like F-18. However, for larger atoms such as Cl-38, this is an important feature. C1 UNIV NEBRASKA,DEPT CHEM,LINCOLN,NE 68588. RP FERRIERI, RA (reprint author), BROOKHAVEN NATL LAB,DEPT CHEM,UPTON,NY 11973, USA. NR 12 TC 2 Z9 2 U1 0 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0022-3654 J9 J PHYS CHEM-US JI J. Phys. Chem. PD APR 15 PY 1993 VL 97 IS 15 BP 3918 EP 3921 DI 10.1021/j100117a044 PG 4 WC Chemistry, Physical SC Chemistry GA KX596 UT WOS:A1993KX59600044 ER PT J AU ECKHARDT, CJ PEACHEY, NM SWANSON, DR TAKACS, JM KHAN, MA GONG, X KIM, JH WANG, J UPHAUS, RA AF ECKHARDT, CJ PEACHEY, NM SWANSON, DR TAKACS, JM KHAN, MA GONG, X KIM, JH WANG, J UPHAUS, RA TI SEPARATION OF CHIRAL PHASES IN MONOLAYER CRYSTALS OF RACEMIC AMPHIPHILES SO NATURE LA English DT Article ID LANGMUIR-BLODGETT-FILMS; RESOLUTION AB OPTICAl activity manifested by chiral molecules and crystals is of long-standing interest in physics, chemistry, biology and geology1,2. The structure of chiral lattices in two and three dimensions may provide insights into chiral discrimination, and chiral phases play an important part in the physics and applications of liquid-crystal and amphiphilic films3-7. Here we report the observation of spontaneous separation of chiral phases in an oriented monolayer of rigid, chiral amphiphiles deposited on mica. Atomic force microscopy of the ordered films reveals domains of mirror-image structures. We propose that this may be the signature of separation into domains of pure enantiomers, although other possibilities exist. This separation of chiral phases in two dimensions may be considered analogous to the spontaneous resolution of enantiomers in three-dimensional crystallization, as exploited by Pasteur in 1848 to isolate enantiomers of sodium tartrate1. C1 IOWA STATE UNIV SCI & TECHNOL,AMES LAB,AMES,IA 50011. RP ECKHARDT, CJ (reprint author), UNIV NEBRASKA,DEPT CHEM,LINCOLN,NE 68588, USA. NR 17 TC 131 Z9 131 U1 2 U2 21 PU MACMILLAN MAGAZINES LTD PI LONDON PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW SN 0028-0836 J9 NATURE JI Nature PD APR 15 PY 1993 VL 362 IS 6421 BP 614 EP 616 DI 10.1038/362614a0 PG 3 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA KX438 UT WOS:A1993KX43800040 ER PT J AU WEINBERG, AM AF WEINBERG, AM TI THE RISE AND FALL OF NUCLEARISM - FEAR AND FAITH AS DETERMINANTS OF THE ARMS-RACE - UNGAR,S SO NATURE LA English DT Book Review RP WEINBERG, AM (reprint author), OAK RIDGE INST SCI & EDUC, DIV MED SCI, POB 117, OAK RIDGE, TN 37831 USA. NR 1 TC 0 Z9 0 U1 0 U2 0 PU NATURE PUBLISHING GROUP PI LONDON PA MACMILLAN BUILDING, 4 CRINAN ST, LONDON N1 9XW, ENGLAND SN 0028-0836 EI 1476-4687 J9 NATURE JI Nature PD APR 15 PY 1993 VL 362 IS 6421 BP 663 EP 664 PG 2 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA KX438 UT WOS:A1993KX43800067 ER PT J AU RUGGIERO, AG AF RUGGIERO, AG TI TANDEMS AS INJECTORS FOR SYNCHROTRONS SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 6TH INTERNATIONAL CONF ON ELECTROSTATIC ACCELERATORS AND ASSOCIATED BOOSTERS CY JUN 01-05, 1992 CL MONTEGROTTO TERME, ITALY SP IST NAZL FIS NUCL, UNIV PADOVA, EUROPEAN PHYS SOC, MUNICIPAL ABANO TERME, MUNICIPAL MONTEGROTTO TERME, BRUKER SPECTROSPIN ITALIANA, DEPRETTO ESCHER WYSS, E ZANON AB This is a review on the use of tandem electrostatic accelerators for injection and filling of synchrotrons to accelerate intense beams of heavy ions to relativistic energies. The paper emphasizes the need of operating the tandems in pulsed mode for this application. It has been experimentally demonstrated that at present this type of accelerator still provides the most reliable and best performance. RP RUGGIERO, AG (reprint author), BROOKHAVEN NATL LAB,DEPT ACCELERATOR DEV,UPTON,NY 11973, USA. NR 21 TC 1 Z9 1 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 APR 15 PY 1993 VL 328 IS 1-2 BP 3 EP 9 DI 10.1016/0168-9002(93)90592-6 PG 7 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA KW190 UT WOS:A1993KW19000002 ER PT J AU ALTON, GD JOHNSON, MT MILLS, GD AF ALTON, GD JOHNSON, MT MILLS, GD TI A SIMPLE POSITIVE NEGATIVE SURFACE-IONIZATION SOURCE SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 6TH INTERNATIONAL CONF ON ELECTROSTATIC ACCELERATORS AND ASSOCIATED BOOSTERS CY JUN 01-05, 1992 CL MONTEGROTTO TERME, ITALY SP IST NAZL FIS NUCL, UNIV PADOVA, EUROPEAN PHYS SOC, MUNICIPAL ABANO TERME, MUNICIPAL MONTEGROTTO TERME, BRUKER SPECTROSPIN ITALIANA, DEPRETTO ESCHER WYSS, E ZANON ID INTENSE BEAMS; ION SOURCES; CESIUM AB A versatile, spherical-geometry, self-extraction surface ionization source has been designed, fabricated, and characterized. The source utilizes direct-surface ionization to form either positive or negative ion beams resulting from interactions between highly electropositive or electronegative atoms or molecules and a spherical-sector surface ionizer maintained at approximately 1100-degrees-C. For positive ion generation, the surface ionizer is chosen to be a high-work-function metal such as Mo, Ta, or W; while for negative ion formation, a LaB6 surface ionizer is selected. The design features and performance of the source for each of these modes of operation are discussed in this report. RP ALTON, GD (reprint author), OAK RIDGE NATL LAB,POB 2008,OAK RIDGE,TN 37831, USA. NR 30 TC 15 Z9 15 U1 0 U2 2 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 APR 15 PY 1993 VL 328 IS 1-2 BP 154 EP 159 DI 10.1016/0168-9002(93)90617-Q PG 6 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA KW190 UT WOS:A1993KW19000027 ER PT J AU JONES, NL DITTNER, PF AF JONES, NL DITTNER, PF TI IMPROVED VOLTAGE GRADIENT CONTROL-SYSTEM FOR ELECTROSTATIC ACCELERATORS SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 6TH INTERNATIONAL CONF ON ELECTROSTATIC ACCELERATORS AND ASSOCIATED BOOSTERS CY JUN 01-05, 1992 CL MONTEGROTTO TERME, ITALY SP IST NAZL FIS NUCL, UNIV PADOVA, EUROPEAN PHYS SOC, MUNICIPAL ABANO TERME, MUNICIPAL MONTEGROTTO TERME, BRUKER SPECTROSPIN ITALIANA, DEPRETTO ESCHER WYSS, E ZANON AB An improved voltage gradient control system has been designed and installed in the EN tandem at the Oak Ridge National Laboratory. An improved design was sought due to high failure rates, increasing replacement parts and labor costs, and decreasing availability of the original carbon film resistor systems supplied for the EN-12 at ORNL. The resulting system utilizes two inexpensive, readily available, metal oxide resistors in series between each plane. They are protected by coaxial stainless steel shielding tubes, and spark gaps across individual resistors and adjacent pairs. The new resistors mount atop the column bridge in a compact configuration. This permits easy access both to the resistors and to the interior column components such as the belt. Well controlled gradients now provide improved machine performance. Both initial capital outlay and future maintenance result in reduced costs. Design, installation, performance, and cost details are reported. RP JONES, NL (reprint author), OAK RIDGE NATL LAB,DEPT PHYS,POB 2008,OAK RIDGE,TN 37831, USA. NR 15 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 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD APR 15 PY 1993 VL 328 IS 1-2 BP 191 EP 194 DI 10.1016/0168-9002(93)90625-R PG 4 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA KW190 UT WOS:A1993KW19000035 ER PT J AU ALTON, GD JOHNSON, MT AF ALTON, GD JOHNSON, MT TI PERFORMANCE-CHARACTERISTICS OF A MULTIPLE-SAMPLE, CESIUM-SPUTTER, NEGATIVE-ION SOURCE SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 6TH INTERNATIONAL CONF ON ELECTROSTATIC ACCELERATORS AND ASSOCIATED BOOSTERS CY JUN 01-05, 1992 CL MONTEGROTTO TERME, ITALY SP IST NAZL FIS NUCL, UNIV PADOVA, EUROPEAN PHYS SOC, MUNICIPAL ABANO TERME, MUNICIPAL MONTEGROTTO TERME, BRUKER SPECTROSPIN ITALIANA, DEPRETTO ESCHER WYSS, E ZANON AB A multiple-sample, cesium-sputter, negative-ion source which permits sample changes without disruption of on-line tandem electrostatic accelerator operations is described. The source is equipped with provisions for remotely selecting and moving into the beam position any one of 60 samples by means of stepping motors equipped with absolute shaft encoders. A spherical-sector cesium ionizer is used to produce the cesium beam for sputtering the sample material. The source is equipped with a three-element electrode system which has been designed to increase the perveance for cesium ion beam generation and to improve negative ion beam extraction from the source. Details of the mechanical design features and optics of the three-element electrode system are presented. Data pertinent to source operation and the dependence of negative ion yields on certain source operational parameters are also given. RP ALTON, GD (reprint author), OAK RIDGE NATL LAB,POB 2008,OAK RIDGE,TN 37831, USA. NR 10 TC 3 Z9 3 U1 0 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 APR 15 PY 1993 VL 328 IS 1-2 BP 202 EP 206 DI 10.1016/0168-9002(93)90628-U PG 5 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA KW190 UT WOS:A1993KW19000038 ER PT J AU BOLLINGER, LM PARDO, RC SHEPARD, KW BOGATY, JM CLIFFT, BE MUNSON, FH ZINKANN, G AF BOLLINGER, LM PARDO, RC SHEPARD, KW BOGATY, JM CLIFFT, BE MUNSON, FH ZINKANN, G TI 1ST OPERATIONAL EXPERIENCE WITH THE POSITIVE-ION INJECTOR OF ATLAS SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 6TH INTERNATIONAL CONF ON ELECTROSTATIC ACCELERATORS AND ASSOCIATED BOOSTERS CY JUN 01-05, 1992 CL MONTEGROTTO TERME, ITALY SP IST NAZL FIS NUCL, UNIV PADOVA, EUROPEAN PHYS SOC, MUNICIPAL ABANO TERME, MUNICIPAL MONTEGROTTO TERME, BRUKER SPECTROSPIN ITALIANA, DEPRETTO ESCHER WYSS, E ZANON ID HEAVY-IONS AB The recently completed positive-ion injector for the heavy-ion accelerator ATLAS was designed as a replacement for the tandem injector of the present tandem-linac system and, unlike the tandem, the positive-ion injector is required to provide ions from the full range of the periodic table. The concept for the new injector, which consists of an ECR ion source on a voltage platform coupled to a very-low-velocity superconducting linac, introduces technical problems and uncertainties that are well beyond those encountered previously for superconducting linacs. The solution to these problems and their relationship to performance are outlined, and initial experience in the acceleration of heavy-ion beams through the entire ATLAS system is discussed, The unusually good longitudinal beam quality of ATLAS with its new injector is emphasized. RP BOLLINGER, LM (reprint author), ARGONNE NATL LAB,ARGONNE,IL 60439, USA. NR 15 TC 10 Z9 10 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 APR 15 PY 1993 VL 328 IS 1-2 BP 221 EP 230 DI 10.1016/0168-9002(93)90631-Q PG 10 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA KW190 UT WOS:A1993KW19000041 ER PT J AU OLSEN, DK AF OLSEN, DK TI OPPORTUNITIES WITH ACCELERATED RADIOACTIVE ION-BEAMS SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 6TH INTERNATIONAL CONF ON ELECTROSTATIC ACCELERATORS AND ASSOCIATED BOOSTERS CY JUN 01-05, 1992 CL MONTEGROTTO TERME, ITALY SP IST NAZL FIS NUCL, UNIV PADOVA, EUROPEAN PHYS SOC, MUNICIPAL ABANO TERME, MUNICIPAL MONTEGROTTO TERME, BRUKER SPECTROSPIN ITALIANA, DEPRETTO ESCHER WYSS, E ZANON ID SHAPES AB A discussion of the exciting and rapidly developing field of accelerated radioactive ion beam (RIB) production for nuclear and astrophysics research is presented. In particular, some scientific opportunities with RIBs are highlighted, the methods of RIB production are reviewed, and the existing and proposed facilities for this research are described. In addition, the ORNL RIB project, the only funded ISOL project employing an electrostatic accelerator, is described in some detail. RP OLSEN, DK (reprint author), OAK RIDGE NATL LAB,POB 2008,OAK RIDGE,TN 37831, USA. NR 43 TC 6 Z9 6 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 APR 15 PY 1993 VL 328 IS 1-2 BP 303 EP 320 DI 10.1016/0168-9002(93)90646-Y PG 18 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA KW190 UT WOS:A1993KW19000056 ER PT J AU ALTON, GD HAYNES, DL MILLS, GD OLSEN, DK AF ALTON, GD HAYNES, DL MILLS, GD OLSEN, DK TI SELECTION AND DESIGN OF THE OAK RIDGE RADIOACTIVE ION-BEAM FACILITY TARGET ION-SOURCE SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 6TH INTERNATIONAL CONF ON ELECTROSTATIC ACCELERATORS AND ASSOCIATED BOOSTERS CY JUN 01-05, 1992 CL MONTEGROTTO TERME, ITALY SP IST NAZL FIS NUCL, UNIV PADOVA, EUROPEAN PHYS SOC, MUNICIPAL ABANO TERME, MUNICIPAL MONTEGROTTO TERME, BRUKER SPECTROSPIN ITALIANA, DEPRETTO ESCHER WYSS, E ZANON AB The high-temperature version of the CERN ISOLDE source has been selected as the first source to be used for the generation of radioactive ion beams at the Oak Ridge Radioactive Ion Beam Facility (ORRIBF) because of its low emittance, relatively high ionization efficiency, and capability for producing a broad range of radioactive species. Of equal importance, the source has been cleverly engineered for remote installation, removal and servicing as required for safe handling of highly radioactive contaminated sources, source components, and ancillary equipment. The source design also permits easy modification to lower-temperature versions and conversion from electron impact ionization to either thermal or positive and negative surface ionization sources. The reasons for choosing the CERN ISOLDE source and design features of the source are discussed in this paper. RP ALTON, GD (reprint author), OAK RIDGE NATL LAB,OAK RIDGE,TN 37831, USA. NR 10 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 APR 15 PY 1993 VL 328 IS 1-2 BP 325 EP 329 DI 10.1016/0168-9002(93)90648-2 PG 5 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA KW190 UT WOS:A1993KW19000058 ER PT J AU SHI, J BRUINSMA, R BISHOP, AR AF SHI, J BRUINSMA, R BISHOP, AR TI EXCITATIONS OF THE ONE-DIMENSIONAL, 2-BAND PEIERLS-HUBBARD MODEL AT 3/4 FILLING IN THE LARGE-U LIMIT SO PHYSICAL REVIEW B LA English DT Article ID CHARGE; CHAIN AB We investigate the ground state and the excitation spectrum associated with the localized defect states of the three-quarter-filled, one-dimensional Peierls-Hubbard model. In the continuum limit with an infinite, on-site electron-electron repulsion energy U, the Hamiltonian is mapped onto the N = 1 Gross-Neveu model, in which irrationally charged soliton-antisoliton pairs are formed upon doping, while polarons are unstable. Corrections due to finite- U effects are discussed. However, discreteness effects are found to support excitations absent from the continuum field theory. In particular, for large band separation a novel type of polaron can be formed with a highly localized electronic wave function surrounded by an extended pattern of local lattice distortion. C1 LOS ALAMOS NATL LAB,DIV INFECT DIS,LOS ALAMOS,NM 87545. RP SHI, J (reprint author), UNIV CALIF LOS ANGELES,DEPT PHYS,LOS ANGELES,CA 90024, USA. NR 11 TC 3 Z9 3 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 APR 15 PY 1993 VL 47 IS 15 BP 9181 EP 9188 DI 10.1103/PhysRevB.47.9181 PG 8 WC Physics, Condensed Matter SC Physics GA KZ508 UT WOS:A1993KZ50800001 ER PT J AU GIBSON, A HAYDOCK, R LAFEMINA, JP AF GIBSON, A HAYDOCK, R LAFEMINA, JP TI ABINITIO ELECTRONIC-STRUCTURE COMPUTATIONS WITH THE RECURSION METHOD SO PHYSICAL REVIEW B LA English DT Article ID ADATOMS AB An accurate and efficient algorithm for using the recursion method in ab initio electronic-structure calculations with nonorthogonal real-space basis sets is presented. The matrix representation of the Hamiltonian operator in a localized basis is shown to possess a sparse represention, and is constructed from the Hamiltonian and overlap matrices, but without the full inverse of the overlap matrix. A method for calculating the change in the charge density due to a point defect is described. The mathematical structure of the recursion method is used to show that some local physical quantities, which are related to integrals over the local density of states, converge exponentially with the size of the cluster that surrounds the region of interest. The computation of these local properties scales independently of the number of atoms in the solid. As an illustration, the recursion method is used to compute the band-structure component of the cohesive energy of MgO. C1 PACIFIC NW LAB, MOLEC SCI RES CTR, RICHLAND, WA 99352 USA. RP GIBSON, A (reprint author), UNIV OREGON, INST MAT SCI, EUGENE, OR 97403 USA. NR 18 TC 36 Z9 36 U1 0 U2 2 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 EI 1550-235X J9 PHYS REV B JI Phys. Rev. B PD APR 15 PY 1993 VL 47 IS 15 BP 9229 EP 9237 DI 10.1103/PhysRevB.47.9229 PG 9 WC Physics, Condensed Matter SC Physics GA KZ508 UT WOS:A1993KZ50800007 ER PT J AU KEPLER, RG SOOS, ZG AF KEPLER, RG SOOS, ZG TI EXCITON-EXCITON ANNIHILATION AND EXCITON KINETICS IN POLY(DI-N-HEXYLSILANE) SO PHYSICAL REVIEW B LA English DT Article ID SIGMA-CONJUGATED POLYSILANES; POLY(DI-NORMAL-HEXYLSILANE); POLYMERS; FILMS; POLYSILYLENES; PHOTOPHYSICS; FLUORESCENCE; EXCITATIONS; TRANSPORT; EMISSION AB We have found that charge carriers can be generated by exciton-exciton annihilation in solid films of poly(di-n-hexylsilane). We use this phenomenon to study the kinetics of excitons at ambient temperature and show that the rate constant for exciton-exciton annihilation gamma is 2 X 10(-7) cm3 s-1, in excellent agreement with the value we obtained previously by other means. The quantum efficiency for carrier production, at an electric field of 2 X 10(5) V cm-1, is 1. 3 X 10(-3) per annihilation event. We also show that gamma is independent of the initial energy of the exciton state, even to energies far out on the long-wavelength tail of the exciton absorption band, and that the excitons remain mobile throughout their 600-ps lifetime. C1 PRINCETON UNIV,DEPT CHEM,PRINCETON,NJ 08544. RP KEPLER, RG (reprint author), SANDIA NATL LABS,ALBUQUERQUE,NM 87185, USA. NR 34 TC 20 Z9 20 U1 1 U2 4 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 APR 15 PY 1993 VL 47 IS 15 BP 9253 EP 9262 DI 10.1103/PhysRevB.47.9253 PG 10 WC Physics, Condensed Matter SC Physics GA KZ508 UT WOS:A1993KZ50800011 ER PT J AU SHINAR, R SHINAR, J JIA, H WU, XL AF SHINAR, R SHINAR, J JIA, H WU, XL TI NEGATIVE DISPERSION PARAMETER OF HYDROGEN DIFFUSION IN HYDROGENATED AMORPHOUS-SILICON SO PHYSICAL REVIEW B LA English DT Article ID A-SI-H; MEYER-NELDEL RELATION; STRUCTURAL RELAXATION; TEMPERATURE; GERMANIUM AB The time-dependent diffusion constant D(H)(t) = D00(omegat)-alpha of hydrogen in rf sputter-deposited hydrogenated amorphous Si (a-Si:H) films containing C(H) = 3 - 5 at. % Si-bonded H was observed to increase with the time t at 300 less-than-or-equal-to T less-than-or-equal-to 380-degrees-C, i.e., the dispersion parameter alpha was negative. As in previous studies, alpha(T) generally decreases with T up to a sample-dependent temperature T(m), and increases at higher temperatures. The observed behavior is discussed in relation to structural relaxation processes which affect the distribution of H trapping energies. C1 IOWA STATE UNIV SCI & TECHNOL,AMES LAB,AMES,IA 50011. IOWA STATE UNIV SCI & TECHNOL,DEPT PHYS & ASTRON,AMES,IA 50011. RP SHINAR, R (reprint author), IOWA STATE UNIV SCI & TECHNOL,MICROELECTR RES CTR,AMES,IA 50011, USA. NR 24 TC 10 Z9 10 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 APR 15 PY 1993 VL 47 IS 15 BP 9361 EP 9365 DI 10.1103/PhysRevB.47.9361 PG 5 WC Physics, Condensed Matter SC Physics GA KZ508 UT WOS:A1993KZ50800024 ER PT J AU LU, ZW ZUNGER, A DEUTSCH, M AF LU, ZW ZUNGER, A DEUTSCH, M TI ELECTRONIC CHARGE-DISTRIBUTION IN CRYSTALLINE DIAMOND, SILICON, AND GERMANIUM SO PHYSICAL REVIEW B LA English DT Article ID GROUND-STATE PROPERTIES; DENSITY-FUNCTIONAL CALCULATION; HARTREE-FOCK CALCULATIONS; STRUCTURAL-PROPERTIES; POPULATION ANALYSIS; SCATTERING FACTORS; PSEUDOPOTENTIAL APPROACH; PERIODIC-SYSTEMS; SI; SEMICONDUCTORS AB Recent refinement studies of a consolidated set of Si structure factors have produced information on the Si charge density with an unprecedented level of accuracy, unmatched by any other crystallographic study to date. In this work we examine the extent to which an accurate implementation of the local-density formalism can describe the charge distribution in silicon, as well as that of the experimentally less-refined data on diamond and germanium. Results of a refinement study of recent germanium and diamond measurements are presented and compared with the ab initio calculations. Our ab initio calculated structure factors for Si show a twofold to fivefold improvement in the R factor over previous local-density calculations. We describe in detail, total, valence, and deformation charge-density maps for C, Si, and Ge. We analyze the effects of high-momentum components (currently outside the range of the high-precision measurements) as well as dynamic structure factors on the ensuing charge-density maps. C1 BAR ILAN UNIV, DEPT PHYS, IL-52900 RAMAT GAN, ISRAEL. RP NATL RENEWABLE ENERGY LAB, GOLDEN, CO 80401 USA. RI Zunger, Alex/A-6733-2013 NR 98 TC 69 Z9 69 U1 0 U2 13 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 APR 15 PY 1993 VL 47 IS 15 BP 9385 EP 9410 DI 10.1103/PhysRevB.47.9385 PG 26 WC Physics, Condensed Matter SC Physics GA KZ508 UT WOS:A1993KZ50800027 ER PT J AU VAN DE WALLE, CG LAKS, DB NEUMARK, GF PANTELIDES, ST AF VAN DE WALLE, CG LAKS, DB NEUMARK, GF PANTELIDES, ST TI 1ST-PRINCIPLES CALCULATIONS OF SOLUBILITIES AND DOPING LIMITS - LI, NA, AND N IN ZNSE SO PHYSICAL REVIEW B LA English DT Article ID P-TYPE ZNSE; BAND-GAP SEMICONDUCTORS; MOLECULAR-BEAM EPITAXY; SELF-COMPENSATION; SHALLOW ACCEPTORS; LATTICE LOCATION; EXCITED-STATES; ENERGIES; GROWTH; GAAS AB We present a comprehensive theoretical approach to determine concentrations of dopant impurities in semiconductors. The formalism is applied to the problem of acceptor doping in ZnSe. Formation energies and concentrations of impurities and native defects are expressed as a function of chemical potentials, Tor which experimentally accessible ranges are calculated. We show that limitations in the achievable hole concentrations can be explained by two mechanisms: one is the competition between various substitutional and interstitial configurations (compensation), the other is the solubility limit imposed by formation of other phases. Nitrogen is most promising among the dopants examined. C1 NATL RENEWABLE ENERGY LAB, GOLDEN, CO 80401 USA. COLUMBIA UNIV, DIV MET & MAT SCI, NEW YORK, NY 10027 USA. IBM CORP, THOMAS J WATSON RES CTR, YORKTOWN HTS, NY 10598 USA. RP XEROX CORP, PALO ALTO RES CTR, 3333 COYOTE HILL RD, PALO ALTO, CA 94304 USA. RI Van de Walle, Chris/A-6623-2012 OI Van de Walle, Chris/0000-0002-4212-5990 NR 35 TC 209 Z9 209 U1 2 U2 21 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 EI 1550-235X J9 PHYS REV B JI Phys. Rev. B PD APR 15 PY 1993 VL 47 IS 15 BP 9425 EP 9434 DI 10.1103/PhysRevB.47.9425 PG 10 WC Physics, Condensed Matter SC Physics GA KZ508 UT WOS:A1993KZ50800030 ER PT J AU XU, CH WANG, CZ CHAN, CT HO, KM AF XU, CH WANG, CZ CHAN, CT HO, KM TI SIMULATED-ANNEALING STUDIES OF STRUCTURAL TRENDS IN CARBON CLUSTERS SO PHYSICAL REVIEW B LA English DT Article ID IONS; STABILITY; C-60 AB The structural properties of carbon clusters (C(n), n = 2 - 60) are studied using tight-binding molecular-dynamics simulations. The low-energy ground-state configurations of the clusters are obtained by annealing and compressing n carbon atoms (n = 2 - 60) from the gas phase at high temperatures ( greater-than-or-equal-to 6000 K). We observed a transition from one-dimensional linear and cyclic structures to two-dimensional cage structures as the number of atoms in the cluster increases beyond n = 20. C1 IOWA STATE UNIV SCI & TECHNOL,DEPT PHYS & MICROELECTR RES CTR,AMES,IA 50011. RP XU, CH (reprint author), IOWA STATE UNIV SCI & TECHNOL,AMES LAB,AMES,IA 50011, USA. NR 17 TC 28 Z9 28 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 APR 15 PY 1993 VL 47 IS 15 BP 9878 EP 9880 DI 10.1103/PhysRevB.47.9878 PG 3 WC Physics, Condensed Matter SC Physics GA KZ508 UT WOS:A1993KZ50800082 ER PT J AU KARIMI, M KAPLAN, T MOSTOLLER, M JESSON, DE AF KARIMI, M KAPLAN, T MOSTOLLER, M JESSON, DE TI GE SEGREGATION AT SI-GE (001) STEPPED SURFACES SO PHYSICAL REVIEW B LA English DT Note ID OPTICAL-TRANSITIONS; SUPERLATTICES; SIMULATION; LAYER AB Atomistic calculations using the Stillinger-Weber and Tersoff interatomic potentials are used to study the energetics of Si-Ge interchange at Si step edges on (001) Ge surfaces. The calculations indicate that Ge segregation at S(B) rebonded step edges is energetically favored. This is consistent with the Ge-pump model of Jesson, Pennycook, and Baribeau [Phys. Rev. Lett. 66, 750 (199 1)]. C1 INDIANA UNIV PENN,INDIANA,PA 15701. RP KARIMI, M (reprint author), OAK RIDGE NATL LAB,DIV SOLID STATE,OAK RIDGE,TN 37831, USA. OI Jesson, David/0000-0003-0897-1445 NR 12 TC 29 Z9 30 U1 0 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 APR 15 PY 1993 VL 47 IS 15 BP 9931 EP 9932 DI 10.1103/PhysRevB.47.9931 PG 2 WC Physics, Condensed Matter SC Physics GA KZ508 UT WOS:A1993KZ50800097 ER PT J AU SHEA, MJ COMPTON, RN AF SHEA, MJ COMPTON, RN TI SURFACE-PLASMON EJECTION OF AG+ IONS FROM LASER IRRADIATION OF A ROUGHENED SILVER SURFACE SO PHYSICAL REVIEW B LA English DT Note ID ENHANCED RAMAN-SCATTERING; DESORPTION; ENERGY AB The kinetic-energy distribution of Ag+ ions ejected from a roughened silver surface irradiated with p-polarized laser light at 532 and 355 nm shows two prominent peaks: thermal Ag+ ions in the range of 0 to 0.5 eV and Ag+ ions with a mean kinetic energy of approximately 3.6 eV (2 eV full width at half maximum). Irradiation with 266-nm light shows only the thermal peak. The dependence of the 3.6-eV peak on surface roughness, light polarization, and wavelength implicates a coupling to surface plasmons (SP's); the SP energy for Ag is also approximately 3.7 eV. C1 OAK RIDGE NATL LAB,OAK RIDGE,TN 37831. RP SHEA, MJ (reprint author), VANDERBILT UNIV,DEPT PHYS & ASTRON,NASHVILLE,TN 37235, USA. NR 20 TC 30 Z9 30 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 APR 15 PY 1993 VL 47 IS 15 BP 9967 EP 9970 DI 10.1103/PhysRevB.47.9967 PG 4 WC Physics, Condensed Matter SC Physics GA KZ508 UT WOS:A1993KZ50800107 ER PT J AU OSORIO, R LU, ZW WEI, SH ZUNGER, A AF OSORIO, R LU, ZW WEI, SH ZUNGER, A TI 1ST-PRINCIPLES PHASE-DIAGRAMS OF PSEUDOTERNARY CHALCOPYRITE ZINCBLENDE ALLOYS SO PHYSICAL REVIEW B LA English DT Note ID SEMICONDUCTORS; SYSTEM AB The temperature-composition phase diagrams of the pseudoternary (CuInSe2)1-x(ZnSe)2x and (ZnSnP2)1-x(GaP)2x chalcopyrite-zinc-blende semiconducting alloys are obtained by a combination of first-principles total-energy calculations with a statistical-mechanics description of a spin-1 Hamiltonian. We find that (i) alloying with zinc blende sharply lowers the order-disorder transition temperature of the chalcopyrite, (ii) despite the different crystal structures of the constituents, the alloy exhibits miscibility already above approximately 500 K, and (iii) while the equilibrium ground state corresponds to phase separation, a metastable long-range-ordered intermediate stannite-type compound CuInZn2Se4 is predicted. RP OSORIO, R (reprint author), NATL RENEWABLE ENERGY LAB,GOLDEN,CO 80401, USA. NR 20 TC 14 Z9 14 U1 0 U2 11 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 APR 15 PY 1993 VL 47 IS 15 BP 9985 EP 9988 DI 10.1103/PhysRevB.47.9985 PG 4 WC Physics, Condensed Matter SC Physics GA KZ508 UT WOS:A1993KZ50800112 ER PT J AU WEINBERGER, P SZUNYOGH, L BENNETT, BI AF WEINBERGER, P SZUNYOGH, L BENNETT, BI TI THEORETICAL BAND-STRUCTURE SPECTROSCOPY OF AUXPD1-X ALLOYS SO PHYSICAL REVIEW B LA English DT Article ID ELECTRONIC-STRUCTURE; AUGER-SPECTRA AB Based on electronic structure calculations in terms of the all-electron self-consistent-field fully relativistic Korringa-Kohn-Rostoker coherent potential approximation for AuxPd1-x, the ultraviolet photoelectron, the Au N-6 N-7 x-ray emission, as well as the Au N-6 N-7 valence-valence (VV) and the Pd M4,5 VV Auger electron intensities are calculated for a wide range of concentrations by using the fully relativistic approaches for the corresponding cross sections. The variation of the line shapes for these spectra can be explained mostly by the changes of the valence d band with the concentration. Good quantitative agreement with available experiments is found. C1 LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545. RP WEINBERGER, P (reprint author), VIENNA TECH UNIV,INST TECH ELEKTROCHEM,GETREIDEMARKT 9-158,A-1060 VIENNA,AUSTRIA. RI Szunyogh, Laszlo/A-7956-2010 NR 14 TC 20 Z9 20 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 APR 15 PY 1993 VL 47 IS 16 BP 10154 EP 10157 DI 10.1103/PhysRevB.47.10154 PG 4 WC Physics, Condensed Matter SC Physics GA LA298 UT WOS:A1993LA29800011 ER PT J AU WEINBERGER, P BLAAS, C BENNETT, BI BORING, AM AF WEINBERGER, P BLAAS, C BENNETT, BI BORING, AM TI FULLY RELATIVISTIC EFFECTIVE PAIR INTERACTIONS FOR THE AU-PD SYSTEM SO PHYSICAL REVIEW B LA English DT Article ID FERMI-SURFACE; CU-PT; ALLOYS AB Based on all-electron self-consistent fully relativistic Korringa-Kohn-Rostoker coherent potential approximation results, concentration- and lattice-parameter-dependent effective pair interactions up to the fifth nearest neighbors are calculated in terms of the fully relativistic embedded cluster method for the Au-Pd system. The obtained effective pair interactions are then used to evaluate a simplified (V1, V2) phase diagram, ordering energies, and related quantities. C1 LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545. RP WEINBERGER, P (reprint author), VIENNA TECH UNIV,INST TECH ELEKTROCHEM,GETREIDEMARKT 9-158,A-1040 VIENNA,AUSTRIA. NR 15 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 APR 15 PY 1993 VL 47 IS 16 BP 10158 EP 10163 DI 10.1103/PhysRevB.47.10158 PG 6 WC Physics, Condensed Matter SC Physics GA LA298 UT WOS:A1993LA29800012 ER PT J AU CORKILL, JL COHEN, ML AF CORKILL, JL COHEN, ML TI BAND-GAPS IN SOME GROUP-IV MATERIALS - A THEORETICAL-ANALYSIS SO PHYSICAL REVIEW B LA English DT Article ID PRESSURE COEFFICIENTS; SUPERLATTICES; ALLOYS AB We have studied the effects of expansion of the lattice on band-edge levels in Si, Ge, Sn, and SiSn. The variation in the gap in the Si-Ge-Sn series can be explained as moving along a universal curve of the variation of band-edge levels with the combined effect of volume and potential. For all of the materials studied, the gap at low volumes is from GAMMA to X. There is a small range of volumes where the gap is from GAMMA to L, and at high volumes the gap is direct until it closes. Thus, in addition to the usual process of applying postive pressure to close the gap, applying negative pressure also causes band overlap and metallization. C1 LAWRENCE BERKELEY LAB,DIV MAT SCI,BERKELEY,CA 94720. RP CORKILL, JL (reprint author), UNIV CALIF BERKELEY,DEPT PHYS,BERKELEY,CA 94720, USA. NR 17 TC 22 Z9 22 U1 0 U2 4 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 APR 15 PY 1993 VL 47 IS 16 BP 10304 EP 10309 DI 10.1103/PhysRevB.47.10304 PG 6 WC Physics, Condensed Matter SC Physics GA LA298 UT WOS:A1993LA29800027 ER PT J AU LUCAS, CA DOWER, CS MCMORROW, DF WONG, GCL LAMELAS, FJ FUOSS, PH AF LUCAS, CA DOWER, CS MCMORROW, DF WONG, GCL LAMELAS, FJ FUOSS, PH TI ORDER-DISORDER C(4X2)-(2X1) TRANSITION ON GE(001) - AN INSITU X-RAY-SCATTERING STUDY SO PHYSICAL REVIEW B LA English DT Article ID TUNNELING MICROSCOPY; SURFACE-STRUCTURE; DIFFRACTION; RECONSTRUCTIONS; SI(001) AB Using in situ x-ray diffraction, we have studied the order-disorder phase transition on the Ge(001) surface by measuring the temperature dependence of a superlattice reflection specific to the c(4X2) low-temperature phase. The results indicate that the transition corresponds to a two-dimensional phase transition with anisotropic interaction energies along and perpendicular to the dimer rows that form the (2X1) surface. Due to pinning of the c(4X2) domains by defects, we are unable to observe any universal critical behavior. The results indicate that the number of buckled dimers involved in the c (4X2) reconstruction is conserved through the transition. This implies that above room temperature the (2X1) surface consists of a random array of buckled dimers. C1 UNIV EDINBURGH,DEPT PHYS,EDINBURGH EH9 3JZ,MIDLOTHIAN,SCOTLAND. UNIV OXFORD,CLARENDON LAB,DEPT PHYS,OXFORD OX1 3PU,ENGLAND. UNIV CALIF BERKELEY,DEPT PHYS,BERKELEY,CA 94720. AT&T BELL LABS,MURRAY HILL,NJ 07974. RP LUCAS, CA (reprint author), LAWRENCE BERKELEY LAB,CTR ADV MAT,DIV MAT SCI,BERKELEY,CA 94720, USA. RI McMorrow, Desmond/C-2655-2008; OI McMorrow, Desmond/0000-0002-4947-7788; Lucas, Christopher/0000-0001-5743-3868 NR 30 TC 40 Z9 40 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 APR 15 PY 1993 VL 47 IS 16 BP 10375 EP 10382 DI 10.1103/PhysRevB.47.10375 PG 8 WC Physics, Condensed Matter SC Physics GA LA298 UT WOS:A1993LA29800035 ER PT J AU ZHOU, YL CAMPUZANO, JC KAUKASOINA, P LINDROOS, M JENNINGS, G AF ZHOU, YL CAMPUZANO, JC KAUKASOINA, P LINDROOS, M JENNINGS, G TI SURFACE CRYSTALLOGRAPHY OF COSI2(111) DETERMINED BY DYNAMIC LOW-ENERGY ELECTRON-DIFFRACTION SO PHYSICAL REVIEW B LA English DT Article ID PHOTOELECTRON DIFFRACTION; COBALT DISILICIDE; METAL DISILICIDES; SI(111); SILICIDES; STATES; INTERFACE; DENSITIES; NISI2 AB The surface crystallography of bulk CoSi2(111) has been studied by low-energy electron diffraction. Measurements using primary-electron energies between 60 and 400 eV indicate that the surface is terminated by one Si layer above the first Co layer. Excellent agreement between the measured I-V curves and the calculated ones has been achieved with a model in which the interlayer spacing between the top (Si) and the second (Co) layer is contracted by 0.09 angstrom, the spacing between the second (Co) and third (Si) layer is expanded by 0.02 angstrom, and the spacing between the third (Si) and fourth (Si) layer is contracted by 0.02 angstrom, with a Pendry r-factor of 0. 14. C1 ARGONNE NATL LAB,ARGONNE,IL 60439. TAMPERE UNIV TECHNOL,SF-33101 TAMPERE,FINLAND. RP ZHOU, YL (reprint author), UNIV ILLINOIS,DEPT PHYS,POB 4348,CHICAGO,IL 60607, USA. RI Campuzano, Juan Carlos/G-4358-2012 NR 30 TC 4 Z9 4 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 APR 15 PY 1993 VL 47 IS 16 BP 10395 EP 10401 DI 10.1103/PhysRevB.47.10395 PG 7 WC Physics, Condensed Matter SC Physics GA LA298 UT WOS:A1993LA29800038 ER PT J AU RALLS, KS RALPH, DC BUHRMAN, RA AF RALLS, KS RALPH, DC BUHRMAN, RA TI IMPACT OF A SINGLE DEFECT ON THE CONDUCTANCE - LOCAL INTERFERENCE AND UNIVERSAL CONDUCTANCE FLUCTUATIONS SO PHYSICAL REVIEW B LA English DT Article ID METAL NANOBRIDGES; MAGNETIC-FIELD; POINT-CONTACT; 1/F NOISE; SENSITIVITY; SAMPLES; STATE AB By reversibly reconfiguring a single defect in a mesoscopic copper nanobridge < 10 nm wide, we have measured both the local interference and universal-conductance-fluctuation contributions to the impact of a single defect on the conductance. Both effects are in good agreement with the predictions of theory, despite the fact that the defects that reconfigure are more complicated than simple point defects. C1 LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550. RP RALLS, KS (reprint author), CORNELL UNIV,SCH APPL & ENGN PHYS,ITHACA,NY 14853, USA. RI Ralph, Daniel/G-3251-2010 NR 29 TC 10 Z9 10 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 APR 15 PY 1993 VL 47 IS 16 BP 10509 EP 10514 DI 10.1103/PhysRevB.47.10509 PG 6 WC Physics, Condensed Matter SC Physics GA LA298 UT WOS:A1993LA29800052 ER PT J AU ZUO, JK WARMACK, RJ ZEHNER, DM WENDELKEN, JF AF ZUO, JK WARMACK, RJ ZEHNER, DM WENDELKEN, JF TI PERIODIC FACETING ON TAC(110) - OBSERVATIONS USING HIGH-RESOLUTION LOW-ENERGY ELECTRON-DIFFRACTION AND SCANNING-TUNNELING-MICROSCOPY SO PHYSICAL REVIEW B LA English DT Article ID SURFACE; RECONSTRUCTION; TRANSITION; PT(110) AB Unidirectional alternating (100)-(010) faceting has been observed for the clean TaC(110) surface using both high-resolution low-energy electron diffraction and scanning tunneling microscopy. Facets propagate periodically along the [110BAR] direction a rid form a ridge-and-valley grating, characterized by an average periodicity of approximately 6 lattice spacings in the [110BAR] direction, where (110) terraces are completely absent. This faceted surface is shown to be an energetically favored structure. C1 OAK RIDGE NATL LAB,OAK RIDGE,TN 37831. OI Warmack, Robert/0000-0001-8298-2420 NR 16 TC 27 Z9 27 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 APR 15 PY 1993 VL 47 IS 16 BP 10743 EP 10747 DI 10.1103/PhysRevB.47.10743 PG 5 WC Physics, Condensed Matter SC Physics GA LA298 UT WOS:A1993LA29800081 ER PT J AU WARREN, OL KANG, HC SCHMITZ, PJ THIEL, PA KAUKASOINA, P LINDROOS, M AF WARREN, OL KANG, HC SCHMITZ, PJ THIEL, PA KAUKASOINA, P LINDROOS, M TI DETERMINATION OF (1X1) AND (1X2) STRUCTURES OF PT THIN-FILMS ON PD(110) BY DYNAMIC LOW-ENERGY ELECTRON-DIFFRACTION ANALYSIS SO PHYSICAL REVIEW B LA English DT Article ID LEED INTENSITY ANALYSIS; MISSING-ROW MODEL; PT(110)-(1X2) SURFACE; MULTILAYER RELAXATION; 110 SURFACE; GROWTH; RECONSTRUCTION; TEMPERATURE; OSCILLATIONS; AU AB Geometric structures of (I X 1) and (I X 2) Pt thin films on Pd(I 10) have been determined by dynamical low-energy electron-diffraction analysis. The (1 X 1) structure is found to exhibit relaxations in the first two interlayer spacings of DELTAd12 = - 11.0% and DELTAd23 = 6.6% at a Pt coverage of one monolayer, and relaxations of DELTAd12 = - 6.6% and DELTAd23 = 4.4% at two monolayers. As for the (1 x 2) structure, the top three layers are found to be Pt. The topmost layer is of the missing-row type, the second layer is slightly row paired (0.06 angstrom), and the third layer is significantly rumpled (0.23 angstrom). Relaxations in the first four inter layer spacings are found to be DETLAd12 = - 9.5%, DELTAd23 = - 8.0%, DELTAd34 = - 7.3%, and DELTAd45 = 2.2%. Except for a significantly less contracted first interlayer spacing, the (I X 2) structure of the Pt film mimics the (1 X 2) structure of bulk Pt(110). C1 IOWA STATE UNIV SCI & TECHNOL,AMES LAB,AMES,IA 50011. TAMPERE UNIV TECHNOL,SF-33101 TAMPERE,FINLAND. RP WARREN, OL (reprint author), IOWA STATE UNIV SCI & TECHNOL,DEPT CHEM,AMES,IA 50011, USA. RI Kang, Hway Chuan/A-3401-2012 NR 39 TC 4 Z9 4 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 APR 15 PY 1993 VL 47 IS 16 BP 10839 EP 10847 DI 10.1103/PhysRevB.47.10839 PG 9 WC Physics, Condensed Matter SC Physics GA LA298 UT WOS:A1993LA29800091 ER PT J AU WARREN, OL THIEL, PA AF WARREN, OL THIEL, PA TI DYNAMIC LOW-ENERGY ELECTRON-DIFFRACTION INVESTIGATION OF LATERAL DISPLACEMENTS IN THE TOPMOST LAYER OF PD(110) SO PHYSICAL REVIEW B LA English DT Article ID 110 SURFACE; LEED; ADSORPTION AB Based on He-atom diffraction evidence for an order-disorder transition on Pd(110) at 230 K, other authors have proposed a model in which the atoms of the topmost layer are displaced laterally by 0.7 angstrom along the [001] direction, with the directions of the displacements correlated at T < 230 K, but largely uncorrelated at T > 230 K. To test this model, we have examined the proposed ordered phase by dynamical low-energy electron-diffraction analysis. Our results favor a nonlaterally displaced geometry, with a contraction of 4.4+/-1.5% in the first interlayer spacing and an expansion of 1.5+/-1.5% in the second interlayer spacing, but do not conclusively rule out the possibility of lateral displacements < ca. 0.13 angstrom. Nevertheless, lateral displacements of the magnitude required to account for the He-atom diffraction results are clearly not present. C1 IOWA STATE UNIV SCI & TECHNOL,AMES LAB,AMES,IA 50011. RP WARREN, OL (reprint author), IOWA STATE UNIV SCI & TECHNOL,DEPT CHEM,AMES,IA 50011, USA. NR 16 TC 10 Z9 10 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 APR 15 PY 1993 VL 47 IS 16 BP 10848 EP 10851 DI 10.1103/PhysRevB.47.10848 PG 4 WC Physics, Condensed Matter SC Physics GA LA298 UT WOS:A1993LA29800092 ER PT J AU DAW, MS AF DAW, MS TI MODEL FOR ENERGETICS OF SOLIDS BASED ON THE DENSITY-MATRIX SO PHYSICAL REVIEW B LA English DT Note ID INTERATOMIC POTENTIALS; TRANSITION-METALS; SURFACES; SILICON AB We propose a model for energetics of solids, based on a direct solution for the density matrix directly from the Hamiltonian. The approach is suitable for obtaining an approximate, finite-ranged density matrix in a basis of localized orbitals. This scheme scales linearly with the size of the system, and should represent an improvement over the much-used embedded-atom, cluster-functional, and bond-order potentials. RP DAW, MS (reprint author), SANDIA NATL LABS,DEPT THEORY,LIVERMORE,CA 94551, USA. NR 15 TC 204 Z9 205 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 APR 15 PY 1993 VL 47 IS 16 BP 10895 EP 10898 DI 10.1103/PhysRevB.47.10895 PG 4 WC Physics, Condensed Matter SC Physics GA LA298 UT WOS:A1993LA29800100 ER PT J AU MASSAROTTI, A QUASHNOCK, JM AF MASSAROTTI, A QUASHNOCK, JM TI DOMAIN-WALLS, WAKES, AND STRUCTURE FORMATION SO PHYSICAL REVIEW D LA English DT Article ID DARK MATTER; EVOLUTION; UNIVERSE; STRINGS AB We consider a cosmological domain wall model where the dark matter interacts nongravitationally with the walls. We find that the dark matter is quickly (as early as z congruent-to 100) swept up in wakes and voids, with the wakes growing with time in a self-similar manner. The dark matter wakes, of order 5h-1 Mpc thick today, tug on the baryons, which also trail behind in wakes of similar thickness. We find that the peculiar motions induced are of the order of a few hundred km/s, coherent on a scale of order 20h-1 Mpc. The baryon overdensities generated by the domain walls are distributed in a geometry similar to that of galaxy superclusters found in recent survey. C1 NASA,CTR FERMILAB ASTROPHYS,FERMI NATL ACCELERATOR LAB,BATAVIA,IL 60510. RP MASSAROTTI, A (reprint author), UNIV CHICAGO,ENRICO FERMI INST,CHICAGO,IL 60637, USA. NR 21 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 APR 15 PY 1993 VL 47 IS 8 BP 3177 EP 3183 DI 10.1103/PhysRevD.47.3177 PG 7 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA KY674 UT WOS:A1993KY67400011 ER PT J AU GALASSI, M AF GALASSI, M TI LAPSE AND SHIFT IN REGGE CALCULUS SO PHYSICAL REVIEW D LA English DT Article ID NULL-STRUT CALCULUS; EQUATIONS; BOUNDARY; GRAVITY AB I use my (3 + 1)-dimensional Regge calculus code to give the first explicit verification that there is an approximate diffeomorphism invariance in Regge calculus. In particular I evolve a neighborhood in a spacelike hypersurface numerically, and show that one may choose lapse and shift freely. I use my numerical approach to analyze the structure of this discrete diffeomorphism group. I also study the constraints in Regge calculus, and find that they are proportional to the third power of the lattice spacing. C1 LOS ALAMOS NATL LAB,DIV THEORET,THEORET ASTROPHYS GRP,LOS ALAMOS,NM 87545. RP GALASSI, M (reprint author), SUNY STONY BROOK,INST THEORET PHYS,STONY BROOK,NY 11794, USA. NR 29 TC 5 Z9 5 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 APR 15 PY 1993 VL 47 IS 8 BP 3254 EP 3264 DI 10.1103/PhysRevD.47.3254 PG 11 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA KY674 UT WOS:A1993KY67400020 ER PT J AU GELLMANN, M HARTLE, JB AF GELLMANN, M HARTLE, JB TI CLASSICAL EQUATIONS FOR QUANTUM-SYSTEMS SO PHYSICAL REVIEW D LA English DT Article ID LOGICAL REFORMULATION; BROWNIAN-MOTION; WAVE PACKET; MECHANICS AB The origin of the phenomenological deterministic laws that approximately govern the quasiclassical domain of familiar experience is considered in the context of the quantum mechanics of closed systems such as the universe as a whole. A formulation of quantum mechanics is used that predicts probabilities for the individual members of a set of alternative coarse-grained histories that decohere, which means that there is negligible quantum interference between the individual histories in the set. We investigate the requirements for coarse grainings to yield decoherent sets of histories that are quasiclassical, i.e., such that the individual histories obey, with high probability, effective classical equations of motion interrupted continually by small fluctuations and occasionally by large ones. We discuss these requirements generally but study them specifically for coarse grainings of the type that follows a distinguished subset of a complete set of variables while ignoring the rest. More coarse graining is needed to achieve decoherence than would be suggested by naive arguments based on the uncertainty principle. Even coarser graining is required in the distinguished variables for them to have the necessary inertia to approach classical predictability in the presence of the noise consisting of the fluctuations that typical mechanisms of decoherence produce. We describe the derivation of phenomenological equations of motion explicitly for a particular class of models. Those models assume configuration space and a fundamental Lagrangian that is the difference between a kinetic energy quadratic in the velocities and a potential energy. The distinguished variables are taken to be a fixed subset of coordinates of configuration space. The initial density matrix of the closed system is assumed to factor into a product of a density matrix in the distinguished subset and another in the rest of the coordinates. With these restrictions, we improve the derivation from quantum mechanics of the phenomenological equations of motion governing a quasiclassical domain in the following respects: Probabilities of the correlations in time that define equations of motion are explicitly considered. Fully nonlinear cases are studied. Methods are exhibited for finding the form of the phenomenological equations of motion even when these are only distantly related to those of the fundamental action. The demonstration of the connection between quantum-mechanical causality and causality in classical phenomenological equations of motion is generalized. The connections among decoherence, noise, dissipation, and the amount of coarse graining necessary to achieve classical predictability are investigated quantitatively. Routes to removing the restrictions on the models in order to deal with more realistic coarse grainings are described. C1 SANTA FE INST, SANTA FE, NM 87501 USA. UNIV CALIF SANTA BARBARA, DEPT PHYS, SANTA BARBARA, CA 93106 USA. CALTECH, LAURITSEN LAB, PASADENA, CA 91125 USA. RP GELLMANN, M (reprint author), LOS ALAMOS NATL LAB, THEORET ASTROPHYS GRP T-6, LOS ALAMOS, NM 87545 USA. NR 52 TC 509 Z9 510 U1 3 U2 19 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1550-7998 EI 1550-2368 J9 PHYS REV D JI Phys. Rev. D PD APR 15 PY 1993 VL 47 IS 8 BP 3345 EP 3382 DI 10.1103/PhysRevD.47.3345 PG 38 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA KY674 UT WOS:A1993KY67400031 ER PT J AU LANGNAU, A BURKARDT, M AF LANGNAU, A BURKARDT, M TI ULTRAVIOLET REGULARIZATION OF LIGHT-CONE HAMILTONIAN PERTURBATION-THEORY - APPLICATION TO THE ANOMALOUS MAGNETIC-MOMENT OF THE ELECTRON (G-2) IN THE LIGHT-CONE GAUGE SO PHYSICAL REVIEW D LA English DT Article ID RENORMALIZATION; FRAME AB An ultraviolet regularization and renormalization procedure of light-cone perturbation theory which is suitable for a numerical application is discussed. The fourth-order correction to the anomalous magnetic moment of the electron in the light-cone gauge is computed. Several regularizations of the associated light-cone gauge singularity are explored. Local counterterms are constructed to remove the quadratic light-cone divergences from the formalism. Problems of discrete light-cone quantization (DLCQ), beyond one-photon exchange, are also described. RP LANGNAU, A (reprint author), STANFORD UNIV,STANFORD LINEAR ACCELERATOR CTR,STANFORD,CA 94309, USA. NR 25 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 0556-2821 J9 PHYS REV D JI Phys. Rev. D PD APR 15 PY 1993 VL 47 IS 8 BP 3452 EP 3464 DI 10.1103/PhysRevD.47.3452 PG 13 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA KY674 UT WOS:A1993KY67400040 ER PT J AU GOTTLIEB, S KRASNITZ, A HELLER, UM KENNEDY, AD KOGUT, JB RENKEN, RL SINCLAIR, DK SUGAR, RL TOUSSAINT, D WANG, KC AF GOTTLIEB, S KRASNITZ, A HELLER, UM KENNEDY, AD KOGUT, JB RENKEN, RL SINCLAIR, DK SUGAR, RL TOUSSAINT, D WANG, KC TI THERMODYNAMICS OF LATTICE QCD WITH 2 LIGHT QUARKS ON A 16(3) X 8 LATTICE SO PHYSICAL REVIEW D LA English DT Article ID HADRONIC SCREENING LENGTHS; QUANTUM CHROMODYNAMICS; HIGH-TEMPERATURE; GAUGE-THEORY; STAGGERED FERMIONS; PHASE-TRANSITION; CHIRAL-SYMMETRY; PLASMA; SPECTRUM; SUSCEPTIBILITY AB We have carried out a numerical study of the high-temperature behavior of lattice QCD with two flavors of staggered quarks. Our simulations were performed on 16(3) x 8 lattices with a quark mass m(q) = 0.0125, in units of the inverse lattice spacing. By monitoring the Wilson-Polyakov line, the chiral order parameter [psipsiBAR), and the average plaquette, we have determined that a crossover between the low-temperature state of ordinary hadronic matter and the high-temperature quark-gluon plasma occurs at a gauge coupling of 6/g2 = 5.54(2). Thermodynamic quantities do not show a large jump, although the equilibration time becomes quite long in the vicinity of the crossover. We have measured the entropy densities in the neighborhood of the crossover and further into the plasma phase. Measurements of the hadronic screening lengths and the Debye screening lengths were made which cast light on the differences between the two regimes. Finally, we measured the topological susceptibilities to further explore the chiral properties of QCD. C1 FLORIDA STATE UNIV,SUPERCOMP COMPUTAT RES INST,TALLAHASSEE,FL 32306. UNIV ILLINOIS,DEPT PHYS,URBANA,IL 61801. UNIV CENT FLORIDA,DEPT PHYS,ORLANDO,FL 32816. ARGONNE NATL LAB,DIV HEP,ARGONNE,IL 60439. UNIV CALIF SANTA BARBARA,DEPT PHYS,SANTA BARBARA,CA 93106. UNIV ARIZONA,DEPT PHYS,TUCSON,AZ 85721. UNIV NEW S WALES,SCH PHYS,KENSINGTON,NSW 2033,AUSTRALIA. RP GOTTLIEB, S (reprint author), INDIANA UNIV,DEPT PHYS,BLOOMINGTON,IN 47405, USA. NR 48 TC 39 Z9 39 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 APR 15 PY 1993 VL 47 IS 8 BP 3619 EP 3632 DI 10.1103/PhysRevD.47.3619 PG 14 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA KY674 UT WOS:A1993KY67400058 ER PT J AU JAIN, V PAPADOPOULOS, A AF JAIN, V PAPADOPOULOS, A TI ON THE HIGH-T PHASE-TRANSITION IN THE GAUGED SU(2) HIGGS-MODEL SO PHYSICS LETTERS B LA English DT Article ID STANDARD ELECTROWEAK THEORY; BARYON ASYMMETRY; FINITE-TEMPERATURE; UNIVERSE; BARYOGENESIS; BEHAVIOR AB We study the effective field theory of a weakly coupled (3+1)D gauged phi4 type model at high temperature. Our model has 4N real scalars (N complex Higgs doublets) and a gauge group SU (2) which is spontaneously broken by a nonzero scalar field VEV at zero temperature. We find, for sufficiently large N, that the transition from the high temperature symmetry restoring phase to the low temperature phase can be either first order or second order depending on the ratio of the gauge coupling to the scalar self-coupling. RP JAIN, V (reprint author), LAWRENCE BERKELEY LAB,DIV PHYS,1 CYCLOTRON RD,BERKELEY,CA 94720, USA. NR 41 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 APR 15 PY 1993 VL 303 IS 3-4 BP 315 EP 322 DI 10.1016/0370-2693(93)91438-S PG 8 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA KW574 UT WOS:A1993KW57400018 ER PT J AU JAROSZEWICZ, T KURZEPA, PS AF JAROSZEWICZ, T KURZEPA, PS TI INTERSECTIONS OF FERMIONIC PATHS AND 4-FERMION INTERACTIONS SO PHYSICS LETTERS B LA English DT Article ID RANDOM-WALK REPRESENTATION; CLASSICAL SPIN SYSTEMS; CORRELATION INEQUALITIES; ALEATORY WALKS; ISING-MODELS; FIELD-THEORY; TRIVIALITY; DIMENSIONS AB We extend the continuum version of Symanzik's polymer ps representation to fermionic field theories. Assuming the same type of regularization as in phi4 theories, we find that theories with repulsive four-fermion interactions are free in D>2 dimensions, since two generic fermionic paths, of Hausdorff dimension 1, do not intersect in this case. C1 LOS ALAMOS NATL LAB,DIV THEORY T8,LOS ALAMOS,NM 87544. RP JAROSZEWICZ, T (reprint author), UNIV CALIF LOS ANGELES,DEPT PHYS,LOS ANGELES,CA 90024, USA. NR 29 TC 0 Z9 0 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 APR 15 PY 1993 VL 303 IS 3-4 BP 323 EP 326 DI 10.1016/0370-2693(93)91439-T PG 4 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA KW574 UT WOS:A1993KW57400019 ER PT J AU KODAMA, K USHIDA, N MOKHTARANI, A PAOLONE, VS VOLK, JT WILCOX, JO YAGER, PM EDELSTEIN, RM FREYBERGER, AP GIBAUT, DB LIPTON, RJ NICHOLS, WR POTTER, DM RUSS, JS ZHANG, C ZHANG, Y JANG, HI KIM, JY KIM, TI LIM, IT PAC, MY BALLER, BR STEFANSKI, RJ NAKAZAWA, K CHUNG, KS CHUNG, SH KIM, DC PARK, IG PARK, MS SONG, JS YOON, CS CHIKAWA, M ABE, T FUJII, T FUJIOKA, G FUJIWARA, K FUKUSHIMA, H HARA, T TAKAHASHI, Y TARUMA, K TSUZUKI, Y YOKOYAMA, C CHANG, SD CHEON, BG CHO, JH KANG, JS KIM, CO KIM, KY KIM, TY LEE, JC LEE, SB LIM, GY NAM, SW SHIN, TS SIM, KS WOO, JK ISOKANE, Y TSUNEOKA, Y AOKI, S GAUTHIER, A HOSHINO, K KITAMURA, H KOBAYASHI, M MIYANISHI, M NAKAMURA, K NAKAMURA, M NAKAMURA, Y NAKANISHI, S NIU, K NIWA, K NOMURA, M TAJIMA, H YOSHIDA, S ARYAL, M DUNLEA, JM FREDERIKSEN, SG KURAMATA, S LUNDBERG, BG OLEYNIK, GA REAY, NW REIBEL, K SIDWELL, RA STANTON, NR MORIYAMA, K SHIBATA, H KALBFLEISCH, GR SKUBIC, P SNOW, JM WILLIS, SE KUSUMOTO, O NAKAMURA, K OKUSAWA, T TERANAKA, M TOMINAGA, T YOSHIDA, T YUUKI, H OKABE, H YOKOTA, J ADACHI, M KAZUNO, M NIU, E SHIBUYA, H WATANABE, S OHTSUKA, I SATO, Y TEZUKA, I BAHK, SY KIM, SK AF KODAMA, K USHIDA, N MOKHTARANI, A PAOLONE, VS VOLK, JT WILCOX, JO YAGER, PM EDELSTEIN, RM FREYBERGER, AP GIBAUT, DB LIPTON, RJ NICHOLS, WR POTTER, DM RUSS, JS ZHANG, C ZHANG, Y JANG, HI KIM, JY KIM, TI LIM, IT PAC, MY BALLER, BR STEFANSKI, RJ NAKAZAWA, K CHUNG, KS CHUNG, SH KIM, DC PARK, IG PARK, MS SONG, JS YOON, CS CHIKAWA, M ABE, T FUJII, T FUJIOKA, G FUJIWARA, K FUKUSHIMA, H HARA, T TAKAHASHI, Y TARUMA, K TSUZUKI, Y YOKOYAMA, C CHANG, SD CHEON, BG CHO, JH KANG, JS KIM, CO KIM, KY KIM, TY LEE, JC LEE, SB LIM, GY NAM, SW SHIN, TS SIM, KS WOO, JK ISOKANE, Y TSUNEOKA, Y AOKI, S GAUTHIER, A HOSHINO, K KITAMURA, H KOBAYASHI, M MIYANISHI, M NAKAMURA, K NAKAMURA, M NAKAMURA, Y NAKANISHI, S NIU, K NIWA, K NOMURA, M TAJIMA, H YOSHIDA, S ARYAL, M DUNLEA, JM FREDERIKSEN, SG KURAMATA, S LUNDBERG, BG OLEYNIK, GA REAY, NW REIBEL, K SIDWELL, RA STANTON, NR MORIYAMA, K SHIBATA, H KALBFLEISCH, GR SKUBIC, P SNOW, JM WILLIS, SE KUSUMOTO, O NAKAMURA, K OKUSAWA, T TERANAKA, M TOMINAGA, T YOSHIDA, T YUUKI, H OKABE, H YOKOTA, J ADACHI, M KAZUNO, M NIU, E SHIBUYA, H WATANABE, S OHTSUKA, I SATO, Y TEZUKA, I BAHK, SY KIM, SK TI MEASUREMENT OF BEAUTY HADRON PAIR PRODUCTION IN 600 GEV/C PI- EMULSION INTERACTIONS SO PHYSICS LETTERS B LA English DT Article ID HEAVY QUARK PRODUCTION; PARTICLES; COLLISIONS AB We report on the production characteristics and total cross section for 9 beauty hadron pairs produced by a 600 GeV/c pi- beam, the first such information in this energy region. The events were detected in the hybrid emulsion spectrometer of Fermilab Experiment E653. The measured pair cross section for all x(F), assuming linear A dependence, is 33 +/- 11 (stat. ) +/- 6 (syst.) nb/nucleon. Fits of the inclusive single-hadron production distribution to the forms dsigma/dx(F) is-proportional-to (1-\x(F)-x0\)n and dsigma/dp(T)2 is-proportional-to exp(-bp(T)2) give n=5.0(-2.1-1.7)+2.7+1.7, x0=0.06(-0.07-0.03)+0.06+0.02, and b=0.13(-0.04-0.02)+0.05+0.02 (GeV/c)-2. The pairs tend strongly to be produced back-to-back. C1 AICHI UNIV EDUC, KARIYA 448, JAPAN. UNIV CALIF DAVIS, DAVIS, CA 95616 USA. CARNEGIE MELLON UNIV, PITTSBURGH, PA 15213 USA. CHONNAM NATL UNIV, KWANGJU 500757, SOUTH KOREA. FERMILAB NATL ACCELERATOR LAB, BATAVIA, IL 60510 USA. GIFU UNIV, GIFU 50111, JAPAN. GYEONGSANG NATL UNIV, JINJU 660300, SOUTH KOREA. KINKI UNIV, OSAKA, OSAKA 577, JAPAN. KOBE UNIV, KOBE 657, JAPAN. KOREA UNIV, SEOUL 136701, SOUTH KOREA. NAGOYA INST TECHNOL, NAGOYA, AICHI 466, JAPAN. NAGOYA UNIV, NAGOYA, AICHI 464, JAPAN. OHIO STATE UNIV, COLUMBUS, OH 43210 USA. OKAYAMA UNIV, OKAYAMA 700, JAPAN. UNIV OKLAHOMA, NORMAN, OK 73019 USA. OSAKA CITY UNIV, OSAKA 558, JAPAN. SCI EDUC INST OSAKA PREFECTURE, OSAKA 558, JAPAN. TOHO UNIV, FUNABASHI, CHIBA 274, JAPAN. UTSUNOMIYA UNIV, UTSUNOMIYA, TOCHIGI 321, JAPAN. WONKWANG UNIV, IRI 570749, SOUTH KOREA. RI Russ, James/P-3092-2014; Aoki, Shigeki/L-6044-2015 OI Russ, James/0000-0001-9856-9155; NR 25 TC 28 Z9 28 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0370-2693 EI 1873-2445 J9 PHYS LETT B JI Phys. Lett. B PD APR 15 PY 1993 VL 303 IS 3-4 BP 359 EP 367 DI 10.1016/0370-2693(93)91446-T PG 9 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA KW574 UT WOS:A1993KW57400026 ER PT J AU ADRIANI, O AGUILARBENITEZ, M AHLEN, S ALCARAZ, J ALOISIO, A ALVERSON, G ALVIGGI, MG AMBROSI, G AN, Q ANDERHUB, H ANDERSON, AL ANDREEV, VP ANTONOV, L ANTREASYAN, D ARCE, P AREFIEV, A ATAMANCHUK, A AZEMOON, T AZIZ, T BABA, PVKS BACHMANN, S BAGNAIA, P BAKKEN, JA BAKSAY, L BALL, RC BANERJEE, S BAO, J BARILLERE, R BARONE, L BASCHIROTTO, A BATTISTON, R BAY, A BECATTINI, F BECKER, U BEHNER, F BEHRENS, J BENCZE, GL BERDUGO, J BERGES, P BERTUCCI, B BETEV, BL BIASINI, M BILAND, A BILEI, GM BIZZARRI, R BLAISING, JJ BOBBINK, GJ BOCK, R BOHM, A BORGIA, B BOSETTI, M BOURILKOV, D BOURQUIN, M BOUTIGNY, D BOUWENS, B BRAMBILLA, E BRANSON, JG BROCK, IC BROOKS, M BUJAK, A BURGER, JD BURGER, WJ BUSENITZ, J BUYTENHUIJS, A CAI, XD CAPELL, M CARIA, M CARLINO, G CARTACCI, AM 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RUBIO, JA RYKACZEWSKI, H SACHWITZ, M SALICIO, J SALICIO, JM SANDERS, GS SANTOCCHIA, A SARAKINOS, MS SARTORELLI, G SASSOWSKY, M SAUVAGE, G SCHAFER, C SCHEGELSKY, V SCHMITZ, D SCHMITZ, P SCHNEEGANS, M SCHOPPER, H SCHOTANUS, DJ SHOTKIN, S SCHREIBER, HJ SHUKLA, J SCHULTE, R SCHULTE, S SCHULTZE, K SCHWENKE, J SCHWERING, G SCIACCA, C SCOTT, I SEHGAL, R SEILER, PG SENS, JC SERVOLI, L SHEER, I SHEN, DZ SHEVCHENKO, S SHI, XR SHUMILOV, E SHOUTKO, V SON, D SOPCZAK, A SPARTIOTIS, C SPICKERMANN, T SPILLANTINI, P STAROSTA, R STEUER, M STICKLAND, DP STICOZZI, F STONE, H STRAUCH, K STRINGFELLOW, BC SUDHAKAR, K SULTANOV, G SUN, LZ SUTER, H SWAIN, JD SYED, AA TANG, XW TAYLOR, L TERZI, G TING, SCC TING, SM TONUTTI, M TONWAR, SC TOTH, J TSAREGORODTSEV, A TSIPOLITIS, G TULLY, C TUNG, KL ULBRICHT, J URBAN, L UWER, U VALENTE, E VANDEWALLE, RT VETLITSKY, I VIERTEL, G VIKAS, P VIKAS, U VIVARGENT, M VOGEL, H VOGT, H VOROBIEV, I VOROBYOV, AA VUILLEUMIER, L WADHWA, M WALLRAFF, W WANG, C WANG, CR WANG, GH WANG, XL WANG, YF WANG, ZM WEBER, A WEBER, J WEILL, R WENAUS, TJ WENNINGER, J WHITE, M WILLMOTT, C WITTGENSTEIN, F WRIGHT, D WU, SX WYNHOFF, S WYSLOUCH, B XIE, YY XU, JG XU, ZZ XUE, ZL YAN, DS YANG, BZ YANG, CG YANG, G YE, CH YE, JB YE, Q YEH, SC YIN, ZW YOU, JM YUNUS, N YZERMAN, M ZACCARDELLI, C ZEMP, P ZENG, M ZENG, Y ZHANG, DH ZHANG, ZP ZHOU, B ZHOU, GJ ZHOU, JF ZHU, RY ZICHICHI, A VANDERZWAAN, BCC AF ADRIANI, O AGUILARBENITEZ, M AHLEN, S ALCARAZ, J ALOISIO, A ALVERSON, G ALVIGGI, MG AMBROSI, G AN, Q ANDERHUB, H ANDERSON, AL ANDREEV, VP ANTONOV, L ANTREASYAN, D ARCE, P AREFIEV, A ATAMANCHUK, A AZEMOON, T AZIZ, T BABA, PVKS BACHMANN, S BAGNAIA, P BAKKEN, JA BAKSAY, L BALL, RC BANERJEE, S BAO, J BARILLERE, R BARONE, L BASCHIROTTO, A BATTISTON, R BAY, A BECATTINI, F BECKER, U BEHNER, F BEHRENS, J BENCZE, GL BERDUGO, J BERGES, P BERTUCCI, B BETEV, BL BIASINI, M BILAND, A BILEI, GM BIZZARRI, R BLAISING, JJ BOBBINK, GJ BOCK, R BOHM, A BORGIA, B BOSETTI, M BOURILKOV, D BOURQUIN, M BOUTIGNY, D 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E GANGULI, SN GARCIAABIA, P GELE, D GENTILE, S GOLDFARB, S GONG, ZF GONZALEZ, E GOUGAS, A GOUJON, D GRATTA, G GRUENEWALD, M GU, C GUANZIROLI, M GUO, JK GUPTA, VK GURTU, A GUSTAFSON, HR GUTAY, LJ HANGARTER, K HASAN, A HAUSCHILDT, D HE, CF HE, JT HEBBEKER, T HEBERT, M HERTEN, G HERVE, A HILGERS, K HOFER, H HOORANI, H HU, G HU, GQ ILLE, B ILYAS, MM INNOCENTE, V JANSSEN, H JEZEQUEL, S JIN, BN JONES, LW KASSER, A KHAN, RA KAMYSHKOV, Y KAPINOS, P KAPUSTINSKY, JS KARYOTAKIS, Y KAUR, M KHOKHAR, S KIENZLEFOCACCI, MN KIM, JK KIM, SC KIM, YG KINNISON, WW KIRKBY, D KIRSCH, S KITTEL, W KLIMENTOV, A KONIG, AC KOFFEMAN, E KORNADT, O KOUTSENKO, V KOULBARDIS, A KRAEMER, RW KRAMER, T KRASTEV, VR KRENZ, W KRIVSHICH, A KUIJTEN, H KUMAR, KS KUNIN, A LANDI, G LANSKE, D LANZANO, S LEBRUN, P LECOMTE, P LECOQ, P LECOULTRE, P LEE, DM LEEDOM, I LEGGETT, C LEGOFF, JM LEISTE, R LENTI, M LEONARDI, E LEYTENS, X LI, C LI, HT LI, PJ LIAO, JY LIN, WT LIN, ZY LINDE, FL LINDEMANN, B LISTA, L LIU, Y LOHMANN, W LONGO, E LU, YS LUBBERS, JM LUBELSMEYER, K LUCI, C LUCKEY, D LUDOVICI, L LUMINARI, L LUSTERMANN, W MA, JM MA, WG MACDERMOTT, M MALHOTRA, PK MALIK, R MALININ, A MANA, C MAOLINBAY, M MARCHESINI, P MARION, F MARIN, A MARTIN, JP MARTINEZLASO, L MARZANO, F MASSARO, GGG MAZUMDAR, K MCBRIDE, P MCMAHON, T MCNALLY, D MERK, M MEROLA, L MESCHINI, M METZGER, WJ MI, Y MILLS, GB MIR, Y MIRABELLI, G MNICH, J MOLLER, M MONTELEONI, B MORAND, R MORGANTI, S MOULAI, NE MOUNT, R MULLER, S NADTOCHY, A NAGY, E NAPOLITANO, M NESSITEDALDI, F NEWMAN, H NEYER, C NIAZ, MA NIPPE, A NOWAK, H ORGANTINI, G PANDOULAS, D PAOLETTI, S PAOLUCCI, P PASCALA, G PASSALEVA, G PATRICELLI, S PAUL, T PAULUZZI, M PAUS, C PAUSS, F PEI, YJ PENSOTTI, S PERRETGALLIX, D PERRIER, J PEVSNER, A PICCOLO, D PIERI, M PIROUE, PA PLASIL, F PLYASKIN, V POHL, M POJIDAEV, V POSTEMA, H QI, ZD QIAN, JM QURESHI, KN RAGHAVAN, R RAHALCALLOT, G RANCOITA, PG RATTAGGI, M RAVEN, G RAZIS, P READ, K REN, D REN, Z RESCIGNO, M REUCROFT, S RICKER, A RIEMANN, S RIEMERS, BC RILES, K RIND, O RIZVI, HA RODRIGUEZ, FJ ROE, BP ROHNER, M ROHNER, S ROMERO, L ROSE, J ROSIERLEES, S ROSMALEN, R ROSSELET, P VANROSSUM, W ROTH, S RUBBIA, A RUBIO, JA RYKACZEWSKI, H SACHWITZ, M SALICIO, J SALICIO, JM SANDERS, GS SANTOCCHIA, A SARAKINOS, MS SARTORELLI, G SASSOWSKY, M SAUVAGE, G SCHAFER, C SCHEGELSKY, V SCHMITZ, D SCHMITZ, P SCHNEEGANS, M SCHOPPER, H SCHOTANUS, DJ SHOTKIN, S SCHREIBER, HJ SHUKLA, J SCHULTE, R SCHULTE, S SCHULTZE, K SCHWENKE, J SCHWERING, G SCIACCA, C SCOTT, I SEHGAL, R SEILER, PG SENS, JC SERVOLI, L SHEER, I SHEN, DZ SHEVCHENKO, S SHI, XR SHUMILOV, E SHOUTKO, V SON, D SOPCZAK, A SPARTIOTIS, C SPICKERMANN, T SPILLANTINI, P STAROSTA, R STEUER, M STICKLAND, DP STICOZZI, F STONE, H STRAUCH, K STRINGFELLOW, BC SUDHAKAR, K SULTANOV, G SUN, LZ SUTER, H SWAIN, JD SYED, AA TANG, XW TAYLOR, L TERZI, G TING, SCC TING, SM TONUTTI, M TONWAR, SC TOTH, J TSAREGORODTSEV, A TSIPOLITIS, G TULLY, C TUNG, KL ULBRICHT, J URBAN, L UWER, U VALENTE, E VANDEWALLE, RT VETLITSKY, I VIERTEL, G VIKAS, P VIKAS, U VIVARGENT, M VOGEL, H VOGT, H VOROBIEV, I VOROBYOV, AA VUILLEUMIER, L WADHWA, M WALLRAFF, W WANG, C WANG, CR WANG, GH WANG, XL WANG, YF WANG, ZM WEBER, A WEBER, J WEILL, R WENAUS, TJ WENNINGER, J WHITE, M WILLMOTT, C WITTGENSTEIN, F WRIGHT, D WU, SX WYNHOFF, S WYSLOUCH, B XIE, YY XU, JG XU, ZZ XUE, ZL YAN, DS YANG, BZ YANG, CG YANG, G YE, CH YE, JB YE, Q YEH, SC YIN, ZW YOU, JM YUNUS, N YZERMAN, M ZACCARDELLI, C ZEMP, P ZENG, M ZENG, Y ZHANG, DH ZHANG, ZP ZHOU, B ZHOU, GJ ZHOU, JF ZHU, RY ZICHICHI, A VANDERZWAAN, BCC TI A SEARCH FOR THE NEUTRAL HIGGS BOSON AT LEP SO PHYSICS LETTERS B LA English DT Article ID Z0 DECAY; E+E COLLISIONS; MASS; LIMITS AB We update the results of a search for the Standard Model neutral Higgs boson using a data sample corresponding to 1 062 000 hadronic Z decays. We exclude the existence of the Minimal Standard Model Higgs boson in the mass range 0 less-than-or-equal-to m(H) < 57.7 GeV at the 95% confidence level. C1 RHEIN WESTFAL TH AACHEN, INST PHYS 2, W-5100 AACHEN, GERMANY. NATL INST HIGH ENERGY PHYS, NIKHEF, 1009 DB AMSTERDAM, NETHERLANDS. UNIV MICHIGAN, ANN ARBOR, MI 48109 USA. CNRS, IN2P3, LAPP, F-74941 ANNECY LE VIEUX, FRANCE. JOHNS HOPKINS UNIV, BALTIMORE, MD 21218 USA. INST HIGH ENERGY PHYS, BEIJING 100039, PEOPLES R CHINA. INFN, SEZ BOLOGNA, I-40126 BOLOGNA, ITALY. TATA INST FUNDAMENTAL RES, BOMBAY 400005, INDIA. BOSTON UNIV, BOSTON, MA 02215 USA. NORTHEASTERN UNIV, BOSTON, MA 02115 USA. HUNGARIAN ACAD SCI, CENT RES INST PHYS, H-1525 BUDAPEST 114, HUNGARY. HARVARD UNIV, CAMBRIDGE, MA 02139 USA. MIT, CAMBRIDGE, MA 02139 USA. INFN, SEZ FIRENZE, I-50125 FLORENCE, ITALY. UNIV FLORENCE, I-50125 FLORENCE, ITALY. CERN, EUROPEAN LAB PARTICLE PHYS, CH-1211 GENEVA 23, SWITZERLAND. WORLD LAB, FBLJA PROJECT, CH-1211 GENEVA 23, SWITZERLAND. UNIV GENEVA, CH-1211 GENEVA 4, SWITZERLAND. CHINESE UNIV SCI & TECHNOL, USTC, HEFEI 230029, PEOPLES R CHINA. UNIV LAUSANNE, CH-1015 LAUSANNE, SWITZERLAND. LAWRENCE LIVERMORE NATL LAB, LIVERMORE, CA 94550 USA. LOS ALAMOS NATL LAB, LOS ALAMOS, NM 87544 USA. UNIV LYON 1, CNRS, IN2P3, INST PHYS NUCL LYON, F-69622 VILLEURBANNE, FRANCE. CTR INVEST ENERGET MEDIOAMBIENTALES & TECNOL, E-28040 MADRID, SPAIN. INFN, SEZ MILANO, I-20133 MILAN, ITALY. MOSCOW THEORET & EXPTL PHYS INST, MOSCOW, RUSSIA. INFN, SEZ NAPOLI, I-80125 NAPLES, ITALY. UNIV NAPLES, I-80125 NAPLES, ITALY. UNIV CYPRUS, DEPT NAT SCI, NICOSIA, CYPRUS. CATHOLIC UNIV NIJMEGEN, 6525 ED NIJMEGEN, NETHERLANDS. NATL INST NUCL PHYS & HIGH ENERGY PHYS, 6525 ED NIJMEGEN, NETHERLANDS. OAK RIDGE NATL LAB, OAK RIDGE, TN 37831 USA. CALTECH, PASADENA, CA 91125 USA. INFN, SEZ PERUGIA, I-06100 PERUGIA, ITALY. UNIV PERUGIA, I-06100 PERUGIA, ITALY. CARNEGIE MELLON UNIV, PITTSBURGH, PA 15213 USA. PRINCETON UNIV, PRINCETON, NJ 08544 USA. INFN, SEZ ROMA, I-00185 ROME, ITALY. UNIV ROMA LA SAPIENZA, I-00185 ROME, ITALY. ST PETERSBURG NUCL PHYS INST, ST PETERSBURG, RUSSIA. UNIV CALIF SAN DIEGO, LA JOLLA, CA 92093 USA. UNIV SANTIAGO, DEPT FIS PARTICULAS ELEMENTALES, E-15706 SANTIAGO, SPAIN. SHANGHAI INST CERAM, SHANGHAI, PEOPLES R CHINA. BULGARIAN ACAD SCI, INST MECHATRON, BU-1113 SOFIA, BULGARIA. KOREA ADV INST SCI & TECHNOL, CTR HIGH ENERGY PHYS, TAEJON 305701, SOUTH KOREA. UNIV ALABAMA, TUSCALOOSA, AL 35486 USA. PURDUE UNIV, W LAFAYETTE, IN 47907 USA. PAUL SCHERRER INST, CH-5232 VILLIGEN, SWITZERLAND. DESY, INST HOCHENERGIEPHYS, O-1615 ZEUTHEN, GERMANY. SWISS FED INST TECHNOL, CH-8093 ZURICH, SWITZERLAND. UNIV HAMBURG, W-2000 HAMBURG 13, GERMANY. HIGH ENERGY PHYS GRP, TAIPEI, TAIWAN. RP ADRIANI, O (reprint author), RHEIN WESTFAL TH AACHEN, INST PHYS 1, W-5100 AACHEN, GERMANY. RI van der Zwaan, Bob/F-4070-2015; D'Alessandro, Raffaello/F-5897-2015; Duran, Ignacio/H-7254-2015; rodriguez calonge, francisco javier/H-9682-2015; Rancoita, Pier Giorgio/J-9896-2015; Hoorani, Hafeez/D-1791-2013; Arce, Pedro/L-1268-2014; Roth, Stefan/J-2757-2016; Tsaregorodtsev, Andrei/E-3873-2016; Cerrada, Marcos/J-6934-2014; Fiandrini, Emanuele/C-4549-2008; Leijtens, Xaveer/F-3302-2010; Gonzalez Romero, Enrique/L-7561-2014; Vogel, Helmut/N-8882-2014; Ferguson, Thomas/O-3444-2014; Berdugo, Javier/A-2858-2015; Lista, Luca/C-5719-2008; Ludovici, Lucio/F-5917-2011; Servoli, Leonello/E-6766-2012; bertucci, bruna/J-5237-2012 OI van der Zwaan, Bob/0000-0001-5871-7643; D'Alessandro, Raffaello/0000-0001-7997-0306; Rancoita, Pier Giorgio/0000-0002-1990-4283; Arce, Pedro/0000-0003-3009-0484; Roth, Stefan/0000-0003-3616-2223; Longo, Egidio/0000-0001-6238-6787; Ambrosi, Giovanni/0000-0001-6977-9559; Tsaregorodtsev, Andrei/0000-0003-4618-520X; Diemoz, Marcella/0000-0002-3810-8530; Bertucci, Bruna/0000-0001-7584-293X; Filthaut, Frank/0000-0003-3338-2247; Cerrada, Marcos/0000-0003-0112-1691; Leijtens, Xaveer/0000-0001-7794-8236; Gonzalez Romero, Enrique/0000-0003-2376-8920; Vogel, Helmut/0000-0002-6109-3023; Ferguson, Thomas/0000-0001-5822-3731; Berdugo, Javier/0000-0002-7911-8532; Ludovici, Lucio/0000-0003-1970-9960; Servoli, Leonello/0000-0003-1725-9185; NR 42 TC 27 Z9 27 U1 2 U2 5 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0370-2693 EI 1873-2445 J9 PHYS LETT B JI Phys. Lett. B PD APR 15 PY 1993 VL 303 IS 3-4 BP 391 EP 399 DI 10.1016/0370-2693(93)91450-2 PG 9 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA KW574 UT WOS:A1993KW57400030 ER PT J AU WRIGHT, SI ROLLETT, AD STOUT, MG AF WRIGHT, SI ROLLETT, AD STOUT, MG TI INPLANE ANISOTROPY OF AS-ROLLED COPPER SHEET SO SCRIPTA METALLURGICA ET MATERIALIA LA English DT Article ID TEXTURE DEVELOPMENT; LARGE-STRAIN; FCC METALS; DEFORMATION; POLYCRYSTALS RP WRIGHT, SI (reprint author), LOS ALAMOS NATL LAB, LOS ALAMOS, NM 87545 USA. RI Rollett, Anthony/A-4096-2012 OI Rollett, Anthony/0000-0003-4445-2191 NR 21 TC 3 Z9 3 U1 0 U2 2 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0956-716X J9 SCRIPTA METALL MATER JI Scr. Metall. Materialia PD APR 15 PY 1993 VL 28 IS 8 BP 985 EP 990 DI 10.1016/0956-716X(93)90067-3 PG 6 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA KR717 UT WOS:A1993KR71700017 ER PT J AU ASHOUR, S ALKUHAIMI, S MOUTINHO, H MATSON, R ABOUELFOTOUH, F AF ASHOUR, S ALKUHAIMI, S MOUTINHO, H MATSON, R ABOUELFOTOUH, F TI JUNCTION FORMATION AND CHARACTERISTICS OF CDS/CUINSE2/METAL INTERFACES SO THIN SOLID FILMS LA English DT Article ID COPPER INDIUM DISELENIDE; CUINSE2 SINGLE-CRYSTALS; OPTICAL-PROPERTIES AB Polycrystalline thin films of CuInSe2 (CIS) were prepared by galvanic electrochemical (EC) and physical vapor deposition (PVD) methods and were characterized using high resolution photoluminescence at low temperatures to study defect states, scanning electron microscopy to study surface morphology, and transmission electron microscopy to determine the grain size and individual crystallographic orientation of the grains for possible correlation between the properties of the two films. Metal contacts. Schottky devices in the form of Al/p-CIS, and CdS/p-CIS heterostructures were also prepared. The electrical properties of the resulting interfaces were investigated using current voltage (I-V) and capacitance voltage (C-V) characteristics, and by electron-beam-induced current measurements. Devices prepared from PVD films exhibited a higher generation factor G, sharp interfaces and the lowest density of interface states. On the contrary, devices of low G values (made from EC films) showed a much higher density of interface states with a high density of both shallow and deep traps, as detected by deep level transient spectroscopy. The results were used to correlate the resulting variation in the heterojunction characteristics and back contact behavior with the corresponding defect states dominating the CIS. C1 NATL RENEWABLE ENERGY LAB,GOLDEN,CO. RP ASHOUR, S (reprint author), GIRLS COLL,SCI BRANCH,RIYADH,SAUDI ARABIA. NR 15 TC 11 Z9 12 U1 1 U2 4 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE 1 PA PO BOX 564, 1001 LAUSANNE 1, SWITZERLAND SN 0040-6090 J9 THIN SOLID FILMS JI Thin Solid Films PD APR 15 PY 1993 VL 226 IS 1 BP 129 EP 134 DI 10.1016/0040-6090(93)90217-D PG 6 WC Materials Science, Multidisciplinary; Materials Science, Coatings & Films; Physics, Applied; Physics, Condensed Matter SC Materials Science; Physics GA KX142 UT WOS:A1993KX14200023 ER PT J AU YAO, Q BAKAC, A ESPENSON, JH AF YAO, Q BAKAC, A ESPENSON, JH TI OXIDATION OF A MACROCYCLIC NICKEL(II) COMPLEX BY ALKYL HYDROPEROXIDES SO INORGANIC CHEMISTRY LA English DT Article ID TRANSITION-METAL COMPLEXES; AQUEOUS PERCHLORIC-ACID; ELECTRON-SPIN RESONANCE; METHYL(CYCLAM)NICKEL(III) DICATION; HYDROGEN-PEROXIDE; KINETICS; GENERATION; HOMOLYSIS; MECHANISM; RADICALS AB Oxidation of NiL2+ (L = 1,4,8,11-tetraazacyclotetradecane) by alkyl hydroperoxides in acidic aqueous solutions produces NiL3+. Kinetic measurements by the initial-rate method yielded rate constants that were ionic strength dependent. The yields of NiL3+ depend on the relative concentrations of the reactants and improve in the presence of oxygen. Possible causes for these observations are discussed. Bromide ions alter the stoichiometry and products of the reaction with tert-butyl hydroperoxide but have no effect on the reaction with tert-amyl hydroperoxide. This difference is rationalized in terms of the relative reactivities of the intermediate alkoxyl radicals toward beta-scission versus bromide oxidation. The addition of alcohols containing alpha-hydrogens (CH3OH and (CH3)2CHOH) decreases substantially the yield of NiL3+ for reactions with both hydroperoxides. Evidence is presented to attribute this effect to the reduction of NiL3+ by the alpha-hydroxyalkyl radicals formed in the reactions of alcohols with alkyl and alkoxyl radical intermediates. C1 IOWA STATE UNIV SCI & TECHNOL,AMES LAB,AMES,IA 50011. IOWA STATE UNIV SCI & TECHNOL,DEPT CHEM,AMES,IA 50011. NR 33 TC 6 Z9 6 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0020-1669 J9 INORG CHEM JI Inorg. Chem. PD APR 14 PY 1993 VL 32 IS 8 BP 1488 EP 1492 DI 10.1021/ic00060a026 PG 5 WC Chemistry, Inorganic & Nuclear SC Chemistry GA KX646 UT WOS:A1993KX64600026 ER PT J AU MACEK, J TAULBJERG, K AF MACEK, J TAULBJERG, K TI THEORY OF BINARY ENCOUNTER ELECTRONS IN ION ATOM COLLISIONS SO JOURNAL OF PHYSICS B-ATOMIC MOLECULAR AND OPTICAL PHYSICS LA English DT Article ID ASYMMETRIC COLLISIONS; SCATTERING AB An intuitive model of the binary encounter peak in the energy and angular distribution of ionization electrons employs the elastic scattering amplitude for electron-projectile scattering. When the projectile carries some electrons, electron exchange contributes to the elastic scattering. We show that the elastic scattering model, including exchange, derives from a distorted-wave strong-potential Born approximation for ionization to the projectile continuum. This theory incorporates both the binary encounter peak and the continuum capture cusp. C1 OAK RIDGE NATL LAB,OAK RIDGE,TN 37831. AARHUS UNIV,INST PHYS & ASTRON,DK-8000 AARHUS,DENMARK. RP MACEK, J (reprint author), UNIV TENNESSEE,DEPT PHYS,KNOXVILLE,TN 37996, USA. NR 20 TC 13 Z9 13 U1 0 U2 1 PU IOP PUBLISHING LTD PI BRISTOL PA TECHNO HOUSE, REDCLIFFE WAY, BRISTOL, ENGLAND BS1 6NX SN 0953-4075 J9 J PHYS B-AT MOL OPT JI J. Phys. B-At. Mol. Opt. Phys. PD APR 14 PY 1993 VL 26 IS 7 BP 1353 EP 1363 DI 10.1088/0953-4075/26/7/018 PG 11 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA KZ894 UT WOS:A1993KZ89400018 ER PT J AU OLAH, GA MITCHELL, RD SOSNICK, TR WALSH, DA TREWHELLA, J AF OLAH, GA MITCHELL, RD SOSNICK, TR WALSH, DA TREWHELLA, J TI SOLUTION STRUCTURE OF THE CAMP-DEPENDENT PROTEIN-KINASE CATALYTIC SUBUNIT AND ITS CONTRACTION UPON BINDING THE PROTEIN-KINASE INHIBITOR PEPTIDE SO BIOCHEMISTRY LA English DT Article ID CONFORMATIONAL CHANGE; CONSERVED FEATURES; YEAST HEXOKINASE; TROPONIN-C; IDENTIFICATION; CALMODULIN; GLUCOSE; FAMILY AB Small-angle X-ray scattering and Fourier transform infrared (FTIR) spectroscopy experiments have been completed on the catalytic subunit of the cAMP-dependent protein kinase. Measurements were made both with and without the protein kinase inhibitor peptide, PKIalpha(5-22)amide. Binding of the peptide results in an overall contraction of the structure that is characterized by a decrease of 9% in radius of gyration and about 16% in the maximum linear dimension. Both the secondary structure content of the protein/peptide complex, as determined by FTIR, and the solution structure of this binary complex, as determined by X-ray scattering, agree well with the structural characteristics of this complex as elucidated by the crystal structure [Knighton, D. R., Zheng, J., Ten Eyck, L. F., Ashford, V. A., Xuong, N.- H., Taylor, S.S., & Sowadsi, J.M. (1991a) Science 253, 407-414]. Further, the contraction of the structure observed by X-ray scattering upon inhibitor peptide binding is not accompanied by any detectable change in secondary structure content of the kinase. We have modeled the contraction of the kinase upon inhibitor peptide binding as a simple rotation of the large and small lobes seen in the crystal structure such that the cleft between them is closed. For a substrate these changes would then allow catalysis to ensue. The hinge for this movement occurs around a glycine that is one of the protein kinase family consensus amino acids. C1 LOS ALAMOS NATL LAB, DIV ISOTOPE & NUCL CHEM, LOS ALAMOS, NM 87545 USA. UNIV CALIF DAVIS, DEPT BIOL CHEM, DAVIS, CA 95616 USA. OI Trewhella, Jill/0000-0002-8555-6766 FU NIGMS NIH HHS [GMK21019, GM40528] NR 26 TC 71 Z9 74 U1 0 U2 3 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0006-2960 J9 BIOCHEMISTRY-US JI Biochemistry PD APR 13 PY 1993 VL 32 IS 14 BP 3649 EP 3657 DI 10.1021/bi00065a018 PG 9 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA KX179 UT WOS:A1993KX17900018 PM 8385485 ER PT J AU PAN, LS HAN, S KANIA, DR PLANO, MA LANDSTRASS, MI AF PAN, LS HAN, S KANIA, DR PLANO, MA LANDSTRASS, MI TI ELECTRICAL-PROPERTIES OF HIGH-QUALITY DIAMOND FILMS SO DIAMOND AND RELATED MATERIALS LA English DT Article; Proceedings Paper CT 3RD INTERNATIONAL CONF ON THE NEW DIAMOND SCIENCE AND TECHNOLOGY ( ICNDST-3 ) / 3RD EUROPEAN CONF ON DIAMOND, DIAMOND-LIKE AND RELATED COATINGS ( DF 92 ) CY AUG 31-SEP 04, 1992 CL HEIDELBERG, GERMANY AB Significant improvements have been made over the last year in the quality of chemical vapor deposited (CVD) diamond films. In particular, efforts have been made to improve the mobilities and lifetimes of free carriers. Values as high as 4000 cm2 per V-s have been measured for the combined electron and hole mobilities in the best polycrystalline diamond, which is comparable to that of the best single-crystal IIa natural diamonds. Comparable carrier lifetimes have also been observed, ranging from 150 ps to 1 ns in CVD diamond, compared with 100 to 600 ps in natural IIa diamonds. The films were produced by microwave-assisted CVD, and both polycrystalline and epitaxial films were studied. The carrier mobility and lifetime were measured using transient photoconductivity as a function of electric field and excitation density. Both velocity saturation and electron-hole scattering were observed in the CVD films, similar to behavior measured in natural diamonds. The drift distance at an electric field of 10 kV cm-1 was as high as 15 mum. The improved properties are most likely due to lowered defect densities. Comparable results between epitaxial and polycrystalline films suggest that structural defects may not be the limitation. The improved quality is a significant step toward the production of electronic devices made of diamond, in particular diamond detectors for ionizing radiation. Already CVD diamond has been used to detect ultraviolet light, X-rays and high energy charged particles. C1 CRYSTALLUME,MENLO PK,CA 94025. RP PAN, LS (reprint author), LAWRENCE LIVERMORE NATL LAB,L-476,7000 EAST AVE,LIVERMORE,CA 94550, USA. NR 8 TC 27 Z9 29 U1 1 U2 7 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE 1 PA PO BOX 564, 1001 LAUSANNE 1, SWITZERLAND SN 0925-9635 J9 DIAM RELAT MATER JI Diam. Relat. Mat. PD APR 13 PY 1993 VL 2 IS 5-7 BP 820 EP 824 DI 10.1016/0925-9635(93)90231-P PG 5 WC Materials Science, Multidisciplinary SC Materials Science GA LE793 UT WOS:A1993LE79300042 ER PT J AU HAN, S PRUSSIN, SG PAN, LS KANIA, DR LANE, SM DENNIS, G WAGNER, RS HARRIS, K AF HAN, S PRUSSIN, SG PAN, LS KANIA, DR LANE, SM DENNIS, G WAGNER, RS HARRIS, K TI TEMPORALLY RESOLVED RESPONSE OF A NATURAL TYPE-IIA DIAMOND DETECTOR TO SINGLE-PARTICLE EXCITATION SO DIAMOND AND RELATED MATERIALS LA English DT Article; Proceedings Paper CT 3RD INTERNATIONAL CONF ON THE NEW DIAMOND SCIENCE AND TECHNOLOGY ( ICNDST-3 ) / 3RD EUROPEAN CONF ON DIAMOND, DIAMOND-LIKE AND RELATED COATINGS ( DF 92 ) CY AUG 31-SEP 04, 1992 CL HEIDELBERG, GERMANY ID SILICON AB We have measured the response of natural type IIa diamonds to single-particle excitations. Not only do the rise and fall times of pulses decrease as a function of increasing bias, but also the shape of the pulse tails changes from approximately exponential to approximately gaussian in form. Over the range of electric fields between 10(4) and 10(5) V cm-1, rise times are less than 50 ps and fall times approach the carrier transit times across the detector as saturation velocities are approached. A temporally and spatially dependent carrier transport model has been used to interpret the experimental results. To perform these measurements, natural type IIa diamonds were incorporated into 50 OMEGA stripline structures which were coupled to a high bandwidth recording system. The system rise time was measured to be 18.6 +/- 1.8 ps. The detectors were excited with heavy charged particles accelerated with a tandem electrostatic accelerator. At low fields, bulk recombination appears to dominate the fall times. Results at higher fields suggest that the contacts are non-injecting. Incomplete charge collection is clearly seen, even at the highest electric field, which implies that the trapping-recombination dynamics play a significant role in the charge collection process. C1 LAWRENCE LIVERMORE NATL LAB,LASER PROGRAM,LIVERMORE,CA 94550. LOS ALAMOS NATL LAB,DIV ELECTR,LOS ALAMOS,NM 87545. DUBBLEDEE HARRIS CORP,MT ARLINGTON,NJ 07856. RP HAN, S (reprint author), UNIV CALIF BERKELEY,DEPT NUCL ENGN,BERKELEY,CA 94720, USA. NR 17 TC 4 Z9 4 U1 0 U2 0 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE 1 PA PO BOX 564, 1001 LAUSANNE 1, SWITZERLAND SN 0925-9635 J9 DIAM RELAT MATER JI Diam. Relat. Mat. PD APR 13 PY 1993 VL 2 IS 5-7 BP 835 EP 840 DI 10.1016/0925-9635(93)90234-S PG 6 WC Materials Science, Multidisciplinary SC Materials Science GA LE793 UT WOS:A1993LE79300045 ER PT J AU HUNN, JD PARIKH, NR SWANSON, ML ZUHR, RA AF HUNN, JD PARIKH, NR SWANSON, ML ZUHR, RA TI CONDUCTION IN ION-IMPLANTED SINGLE-CRYSTAL DIAMOND SO DIAMOND AND RELATED MATERIALS LA English DT Article ID BORON AB We have implanted sodium, phosphorus and arsenic into single-crystal, type IIa diamond as possible n-type dopants. Particular emphasis was placed on the implantation of sodium at different temperatures and doses; combined implantation energies of 55, 80 and 120 keV were used to provide a uniformly doped layer over a depth of approximately 100 nm. The implanted layers exhibited a semiconducting behavior with a single exponential activation energy between 0.40 and 0.48 eV, as determined by temperature-dependent resistance measurements. A sample implanted to a concentration of 5 x 10(19) Na+ cm-3 at 550-degrees-C exhibited a single activation energy of 0.415 eV over a temperature range from 25 to 500-degrees-C. Thermal annealing above 900-degrees-C was found to remove implantation damage, as measured by optical absorption and Rutherford backscattering-channeling. However, concomitant increases in the resistance and the activation energy were observed. Implantation of Ne-22 was used to introduce a damage density equivalent to the Na-23 implant, while not introducing an electrically active species. The activation energy and the electrical resistance were similar but higher than those produced by implantation with sodium. We conclude that the electrical properties of the sodium-implanted samples were at least partly due to electrically active sodium, but that residual implantation damage was still important. C1 OAK RIDGE NATL LAB, DIV SOLID STATE, OAK RIDGE, TN 37831 USA. RP UNIV N CAROLINA, DEPT PHYS & ASTRON, CHAPEL HILL, NC 27599 USA. NR 17 TC 23 Z9 23 U1 2 U2 9 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0925-9635 EI 1879-0062 J9 DIAM RELAT MATER JI Diam. Relat. Mat. PD APR 13 PY 1993 VL 2 IS 5-7 BP 847 EP 851 DI 10.1016/0925-9635(93)90236-U PG 5 WC Materials Science, Multidisciplinary SC Materials Science GA LE793 UT WOS:A1993LE79300047 ER PT J AU KANIA, DR LANDSTRASS, MI PLANO, MA PAN, LS HAN, S AF KANIA, DR LANDSTRASS, MI PLANO, MA PAN, LS HAN, S TI DIAMOND RADIATION DETECTORS SO DIAMOND AND RELATED MATERIALS LA English DT Article AB Diamond radiation detectors have a lengthy history. Photoconductive UV detectors were developed in the 1920s and ionizing radiation detectors were created in the 1940s. However, these devices encountered restricted usage owing to the limitations of natural diamonds. Specifically, these limitations were the small size and lack of control of the material characteristics. Recent advances in the high quality growth of diamond by chemical vapor deposition have created the opportunity for the application of this material in practical detectors. C1 LAWRENCE LIVERMORE NATL LAB, LIVERMORE, CA 94550 USA. RP CRYSTALLUME, 125 CONSTITUT DR, MENLO PK, CA 94025 USA. NR 37 TC 104 Z9 105 U1 4 U2 19 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0925-9635 EI 1879-0062 J9 DIAM RELAT MATER JI Diam. Relat. Mat. PD APR 13 PY 1993 VL 2 IS 5-7 BP 1012 EP 1019 DI 10.1016/0925-9635(93)90266-5 PG 8 WC Materials Science, Multidisciplinary SC Materials Science GA LE793 UT WOS:A1993LE79300077 ER PT J AU LANDSTRASS, MI PLANO, MA MORENO, MA MCWILLIAMS, S PAN, LS KANIA, DR HAN, S AF LANDSTRASS, MI PLANO, MA MORENO, MA MCWILLIAMS, S PAN, LS KANIA, DR HAN, S TI DEVICE PROPERTIES OF HOMOEPITAXIALLY GROWN DIAMOND SO DIAMOND AND RELATED MATERIALS LA English DT Article; Proceedings Paper CT 3RD INTERNATIONAL CONF ON THE NEW DIAMOND SCIENCE AND TECHNOLOGY ( ICNDST-3 ) / 3RD EUROPEAN CONF ON DIAMOND, DIAMOND-LIKE AND RELATED COATINGS ( DF 92 ) CY AUG 31-SEP 04, 1992 CL HEIDELBERG, GERMANY ID BORON-DOPED DIAMOND; SCHOTTKY DIODES AB Homoepitaxial single-crystal diamond layers were grown on naturally occurring type Ia and IIa gemstone diamond substrates using microwave-plasma-assisted chemical vapor deposition techniques. The epitaxial layers ranged in thickness from 0.5 to 800 mum. Single crystals were grown both unintentionally doped and intentionally doped by means of gas phase dopants. Planar photoconductive diodes were fabricated from the high resistivity crystals and junction diodes were fabricated from the boron-doped crystal layers. The photoconductive diode response was measured and the output signals were analyzed to derive the carrier mobility and lifetime. Combined carrier photoconductive mobility values exceeded 3500 cm2 V-1 s-1, only seen in the best IIa gemstone diamonds. Junction diodes yielded the highest breakdown fields with typical values in excess of 2 x 10(7) V cm-1 dielectric strength. C1 LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550. RP LANDSTRASS, MI (reprint author), CRYSTALLUME,125 CONSTITUT DR,MENLO PK,CA 94025, USA. NR 11 TC 55 Z9 55 U1 1 U2 7 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE 1 PA PO BOX 564, 1001 LAUSANNE 1, SWITZERLAND SN 0925-9635 J9 DIAM RELAT MATER JI Diam. Relat. Mat. PD APR 13 PY 1993 VL 2 IS 5-7 BP 1033 EP 1037 DI 10.1016/0925-9635(93)90269-8 PG 5 WC Materials Science, Multidisciplinary SC Materials Science GA LE793 UT WOS:A1993LE79300080 ER PT J AU SHAKED, H PINTO, H ETTEDGUI, H GAVRA, Z MELAMUD, M JOHNSON, JR REILLY, JJ AF SHAKED, H PINTO, H ETTEDGUI, H GAVRA, Z MELAMUD, M JOHNSON, JR REILLY, JJ TI CRYSTAL-STRUCTURE AND MAGNETIC-PROPERTIES OF DUY2BACUO5 (U=0.00, 0.61, 1.31) SO JOURNAL OF ALLOYS AND COMPOUNDS LA English DT Article ID POWDER DIFFRACTION; HYDROGEN; OXIDES; SUPERCONDUCTIVITY; Y2BACUO5; CU AB Samples of DuY2BaCuO5 (U = 0.61, 1.31), were prepared by a direct reaction of the green phase (Y2BaCuO5) with D2 gas. The crystallographic structure of the three compounds (u = 0.00, 0.61, 1.31) were studied using X-ray and neutron powder diffraction. It was found that as D enters the green phase, a solid solution phase is formed with no symmetry change. Two sites partially occupied by D were determined. The occupancy of these sites is consistent with a maximum solubility of u = 2. The temperature dependence of the magnetic susceptibility of the three samples obeyed the Curie-Weiss law with antiferromagnetic interaction. The paramagnetic Curie temperature decreased with deuteriding, while, the Cu++ magnetic moment remained unchanged. C1 BEN GURION UNIV NEGEV,IL-84105 BEER SHEVA,ISRAEL. BROOKHAVEN NATL LAB,DEPT APPL SCI,UPTON,NY 11973. RP SHAKED, H (reprint author), NUCL RES CTR NEGEV,POB 9001,IL-84190 BEER SHEVA,ISRAEL. NR 23 TC 3 Z9 3 U1 0 U2 0 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE 1 PA PO BOX 564, 1001 LAUSANNE 1, SWITZERLAND SN 0925-8388 J9 J ALLOY COMPD JI J. Alloy. Compd. PD APR 13 PY 1993 VL 194 IS 1 BP 13 EP 17 DI 10.1016/0925-8388(93)90638-4 PG 5 WC Chemistry, Physical; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Chemistry; Materials Science; Metallurgy & Metallurgical Engineering GA KW477 UT WOS:A1993KW47700007 ER PT J AU MALM, JG WILLIAMS, CW SODERHOLM, L MORSS, LR AF MALM, JG WILLIAMS, CW SODERHOLM, L MORSS, LR TI PREPARATION, CHEMICAL-REACTIONS, AND SOME PHYSICAL-PROPERTIES OF NEPTUNIUM PENTAFLUORIDE SO JOURNAL OF ALLOYS AND COMPOUNDS LA English DT Article AB The preparation of NpF5 by reacting a solution containing NpF6- with the Lewis acid BF3 in anhydrous HF is reported. The purity of NpF5 was established by its Mossbauer spectrum, which showed only the presence of Np-5+. Thermal decomposition and some chemical reactions of NpF5 are described. Debye-Scherrer powder data from NpF5 appear similar to those obtained from alpha-UF5, indexing as tetragonal with cell constants a = 6.5358(18) angstrom and c = 4.4562(14) angstrom. Photochemical irradiation of NpF6 produced an amorphous material believed, but not confirmed, to be NpF5. RP MALM, JG (reprint author), ARGONNE NATL LAB,DIV CHEM,9700 S CASS AVE,ARGONNE,IL 60439, USA. NR 19 TC 2 Z9 2 U1 1 U2 1 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE 1 PA PO BOX 564, 1001 LAUSANNE 1, SWITZERLAND SN 0925-8388 J9 J ALLOY COMPD JI J. Alloy. Compd. PD APR 13 PY 1993 VL 194 IS 1 BP 133 EP 137 DI 10.1016/0925-8388(93)90658-A PG 5 WC Chemistry, Physical; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Chemistry; Materials Science; Metallurgy & Metallurgical Engineering GA KW477 UT WOS:A1993KW47700027 ER PT J AU BLAU, PJ AF BLAU, PJ TI FRICTION MICROPROBE INVESTIGATION OF PARTICLE LAYER EFFECTS ON SLIDING FRICTION SO WEAR LA English DT Article; Proceedings Paper CT 9TH INTERNATIONAL CONF ON WEAR OF MATERIALS CY APR 13-16, 1993 CL SAN FRANCISCO, CA AB Interfacial particles (third bodies), resulting from wear or external contamination, can alter and even dominate the frictional behavior of solid-solid sliding in the absence of effective particle removal processes (eg. lubricant flow). A unique friction microprobe, developed at Oak Ridge National Laboratory, was used to conduct fine-scale friction studies using 1.0 mm diameter stainless steel spheres sliding on several sizes of loose layers of fine aluminum oxide powders on both aluminum and alumina surfaces. Conventional, pin-on-disk experiments were conducted to compare behavior with the friction microprobe results. The behavior of the relatively thick particle layers was found to be independent of the nature of underlying substrate, substantiating previous work by other investigators. The time-dependent behavior of friction, for a spherical macrocontact starting from rest, could generally be represented by a series of five rather distinct phases involving static compression, slider breakaway, transition to steady state, and dynamic layer instability. A friction model for the steady state condition, which incorporates lamellar powder layer behavior, is described. RP BLAU, PJ (reprint author), OAK RIDGE NATL LAB,DIV MET & CERAM,POB 2008,OAK RIDGE,TN 37831, USA. NR 17 TC 14 Z9 15 U1 0 U2 0 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE 1 PA PO BOX 564, 1001 LAUSANNE 1, SWITZERLAND SN 0043-1648 J9 WEAR JI Wear PD APR 13 PY 1993 VL 162 BP 102 EP 109 DI 10.1016/0043-1648(93)90490-D PN A PG 8 WC Engineering, Mechanical; Materials Science, Multidisciplinary SC Engineering; Materials Science GA KY195 UT WOS:A1993KY19500014 ER PT J AU GLAESER, WA BAER, D ENGELHARDT, M AF GLAESER, WA BAER, D ENGELHARDT, M TI INSITU WEAR EXPERIMENTS IN THE SCANNING AUGER SPECTROMETER SO WEAR LA English DT Article; Proceedings Paper CT 9TH INTERNATIONAL CONF ON WEAR OF MATERIALS CY APR 13-16, 1993 CL SAN FRANCISCO, CA AB Sliding contact experiments have been conducted in the chamber of a high resolution Auger spectrometer. A pin-on-disk wear tester has been used. The Auger surface analysis capability has been used to characterize the disk surface before and after sliding in the chamber. The effect of surface chemistry on metal transfer during sliding contact and on boundary lubrication of zinc dialkyldithiophosphate (ZDDP) has been investigated. Hydrocarbon 'contamination' from fabrication of the steel disk caused an induction period during sliding in which friction was low and no transfer occurred. The contaminant was eventually worn off but transfer did not take place until the native oxide film was substantially removed also. The oxide film on the steel surface plays an essential role in the boundary lubrication process of ZDDP. A resulting iron sulfide film effectively inhibits adhesive wear. This film was found only in the wear tracks, showing that the contact stress conditions trigger the boundary film reactions. C1 PACIFIC NW LAB, RICHLAND, WA 99352 USA. RP GLAESER, WA (reprint author), BATTELLE MEM INST, 505 KING AVE, COLUMBUS, OH 43201 USA. RI Engelhard, Mark/F-1317-2010; Baer, Donald/J-6191-2013 OI Baer, Donald/0000-0003-0875-5961 NR 6 TC 30 Z9 32 U1 0 U2 2 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE 1 PA PO BOX 564, 1001 LAUSANNE 1, SWITZERLAND SN 0043-1648 J9 WEAR JI Wear PD APR 13 PY 1993 VL 162 BP 132 EP 138 DI 10.1016/0043-1648(93)90494-7 PN A PG 7 WC Engineering, Mechanical; Materials Science, Multidisciplinary SC Engineering; Materials Science GA KY195 UT WOS:A1993KY19500018 ER PT J AU LIU, P BAHADUR, S VERHOEVEN, JD AF LIU, P BAHADUR, S VERHOEVEN, JD TI FURTHER INVESTIGATION ON THE TRIBOLOGICAL BEHAVIOR OF CU-20-PERCENT NB INSITU COMPOSITE SO WEAR LA English DT Article; Proceedings Paper CT 9TH INTERNATIONAL CONF ON WEAR OF MATERIALS CY APR 13-16, 1993 CL SAN FRANCISCO, CA ID METAL-MATRIX COMPOSITES; WEAR BEHAVIOR; TEMPERATURE; GRAPHITE AB Sliding friction and wear behavior of Cu-20 vol.% Nb in situ composite sliding against a tool steel disk was studied under dry ambient conditions. Studies were directed towards the understanding of the roles of the filament and the matrix materials during sliding. It was found that Nb filaments underwent reorientation, shearing and refinement. Irrespective of their prior orientation, Nb filaments close to the contact surface were oriented along the sliding direction. These processes resulted from friction-induced surface deformation and led to the strengthening of the subsurface layer of the composite. There was no separation of Nb filaments from Cu matrix observed in the sliding process. The effects of annealing, sliding speed and filament orientation on the friction and wear behavior of the composite were also investigated. The micromechanisms of wear were studied by scanning electron microscopy. Surface deformation, filament reorientation and refinement, and oxidation seemed to play important roles in the friction and wear processes. C1 IOWA STATE UNIV SCI & TECHNOL,DEPT MECH ENGN,AMES,IA 50011. IOWA STATE UNIV SCI & TECHNOL,DEPT MAT SCI & ENGN,USDOE,AMES LAB,AMES,IA 50011. NR 17 TC 12 Z9 12 U1 0 U2 0 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE 1 PA PO BOX 564, 1001 LAUSANNE 1, SWITZERLAND SN 0043-1648 J9 WEAR JI Wear PD APR 13 PY 1993 VL 162 BP 211 EP 219 DI 10.1016/0043-1648(93)90503-E PN A PG 9 WC Engineering, Mechanical; Materials Science, Multidisciplinary SC Engineering; Materials Science GA KY195 UT WOS:A1993KY19500027 ER PT J AU MARRERO, M ROUTBORT, J WHALEN, P LI, CW KARASEK, KR AF MARRERO, M ROUTBORT, J WHALEN, P LI, CW KARASEK, KR TI SOLID-PARTICLE EROSION OF INSITU REINFORCED SI3N4 SO WEAR LA English DT Article; Proceedings Paper CT 9TH INTERNATIONAL CONF ON WEAR OF MATERIALS CY APR 13-16, 1993 CL SAN FRANCISCO, CA ID BRITTLE MATERIALS; IMPACT DAMAGE; GLASS AB Steady-state solid-particle erosion has been investigated on in situ reinforced Si3N4 and the ''equivalent'' fine-grained hot-isostatically-pressed Si3N4 whose R-curve behaviors are quite different, having K(IC) values in the long-crack limit of 8.3 and 5.6 MPa m1/2 respectively. Experiments were carried out at 20-degrees-C, using SiC abrasives, whose diameters ranged from 42 to 1035 mum, varying the angle of impact from 15 to 90-degrees and the velocity from 50 to 100 to 150 m s-1. The erosion rates of the two materials were, within a factor of two, the same, indicating that the long-crack-length-limit toughness is not an indication of erosion resistance, for the range of particle sizes and velocities studied. C1 ALLIED SIGNAL INC,MORRISTOWN,NJ 07962. ALLIED SIGNAL INC,DES PLAINES,IL 60017. RP MARRERO, M (reprint author), ARGONNE NATL LAB,DIV MAT SCI,ARGONNE,IL 60439, USA. RI Marrero, Madelyn/N-9723-2013 OI Marrero, Madelyn/0000-0002-9509-4374 NR 16 TC 11 Z9 11 U1 0 U2 0 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE 1 PA PO BOX 564, 1001 LAUSANNE 1, SWITZERLAND SN 0043-1648 J9 WEAR JI Wear PD APR 13 PY 1993 VL 162 BP 280 EP 284 DI 10.1016/0043-1648(93)90510-S PN A PG 5 WC Engineering, Mechanical; Materials Science, Multidisciplinary SC Engineering; Materials Science GA KY195 UT WOS:A1993KY19500034 ER PT J AU MAUPIN, HE WILSON, RD HAWK, JA AF MAUPIN, HE WILSON, RD HAWK, JA TI WEAR DEFORMATION OF ORDERED FE-AL INTERMETALLIC ALLOYS SO WEAR LA English DT Article; Proceedings Paper CT 9TH INTERNATIONAL CONF ON WEAR OF MATERIALS CY APR 13-16, 1993 CL SAN FRANCISCO, CA ID SLIDING WEAR; ABRASIVE WEAR AB The Bureau of Mines conducted abrasive wear research on DO, ordered and disordered Fe3Al intermetallics. The effect of abrasion on these alloys was studied through microscopy, X-ray diffraction and hardness measurements. The region near the wear surface undergoes dynamic recrystallization, i.e. the original microstructural morphology of micron-size grains is replaced by one with nanosize grains. Abrasion of the Fe3Al alloys also results in a loss of the DO3 ordering in the wear surface region. The bulk temperature rise of the specimen during abrasion was approximately 28-degrees-C which is insufficient to cause recrystallization in these alloys. Therefore, the flash temperature due to interface frictional heating is considered more important than the bulk temperature when considering dynamic recrystallization as the transformation mechanism in the near wear surface region. C1 US BUR MINES,ALBANY RES CTR,ALBANY,OR 97321. NR 37 TC 43 Z9 43 U1 0 U2 3 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE 1 PA PO BOX 564, 1001 LAUSANNE 1, SWITZERLAND SN 0043-1648 J9 WEAR JI Wear PD APR 13 PY 1993 VL 162 BP 432 EP 440 DI 10.1016/0043-1648(93)90527-S PN A PG 9 WC Engineering, Mechanical; Materials Science, Multidisciplinary SC Engineering; Materials Science GA KY195 UT WOS:A1993KY19500051 ER PT J AU RAO, GR LEE, EH MANSUR, LK AF RAO, GR LEE, EH MANSUR, LK TI STRUCTURE AND DOSE EFFECTS ON IMPROVED WEAR PROPERTIES OF ION-IMPLANTED POLYMERS SO WEAR LA English DT Article; Proceedings Paper CT 9TH INTERNATIONAL CONF ON WEAR OF MATERIALS CY APR 13-16, 1993 CL SAN FRANCISCO, CA AB Polyethylene, polypropylene, polystyrene and polyethersulfone, representing an increasing complexity in molecular structure, were implanted with 200 keV boron to three doses of 1.7, 5 and 17 X 10(18) ions m-2. Polystyrene was also implanted with 100 keV boron to the same three doses. The polymers were investigated for near-surface micromechanical property changes using a nanoindentation technique. Wear properties of the polymers were studied using a reciprocating tribometer with a nylon ball as the counterface. Tests were conducted for 10 000 sliding cycles using a 1 N normal load, a stroke length of 3 mm and an oscillation frequency of 100 cycles min-1. The ion implantation increased the near-surface hardness of the four polymers and the increase was proportional to the dose and beam energy. A clear structure dependence was observed for the hardness changes that were related to cross-linking of molecular chains caused by the ion irradiation. In general, the implantation also significantly improved the wear properties of the four polymers. For each polymer, an optimum dose was identified that yielded the best wear improvement. With increasing dose, the dominant wear mechanism shifted from adhesive and abrasive wear to no observable wear to surface fatigue. Remarkable wear improvements were observed for polystyrene and polyethersulfone for which, at the optimum dose, no wear damage was visible even after 10 000 sliding cycles. RP RAO, GR (reprint author), OAK RIDGE NATL LAB,DIV MET & CERAM,POB 2008,BLDG 5500,MS 6376,OAK RIDGE,TN 37831, USA. NR 14 TC 20 Z9 22 U1 0 U2 1 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE 1 PA PO BOX 564, 1001 LAUSANNE 1, SWITZERLAND SN 0043-1648 J9 WEAR JI Wear PD APR 13 PY 1993 VL 162 BP 739 EP 747 DI 10.1016/0043-1648(93)90074-V PN B PG 9 WC Engineering, Mechanical; Materials Science, Multidisciplinary SC Engineering; Materials Science GA KZ108 UT WOS:A1993KZ10800014 ER PT J AU ANDERSON, RM ADLER, TA HAWK, JA AF ANDERSON, RM ADLER, TA HAWK, JA TI SCALE OF MICROSTRUCTURE EFFECTS ON THE IMPACT RESISTANCE OF AL2O3 SO WEAR LA English DT Article; Proceedings Paper CT 9TH INTERNATIONAL CONF ON WEAR OF MATERIALS CY APR 13-16, 1993 CL SAN FRANCISCO, CA ID ELASTIC-PLASTIC INDENTATION; CERAMICS; DAMAGE; FRACTURE; HARDNESS; ALUMINA AB The impact resistance of alumina (Al2O3) is being investigated by indentation and single-particle-impact tests at the US Bureau of Mines. The primary aim of this research is to gain a better understanding of the mechanisms of material removal as a result of changes in the scale of damage relative to the scale of the microstructure. Preliminary spherical single-particle-impact and quasi-static indentation tests have focused on alumina with grain sizes of approximately 3, 7 and 13 mum, and results to date have shown that, although the crater diameter is not significantly affected by grain size, the deepest craters are produced on the aluminas with the larger grain size. The type, number and extent of crack formation are influenced by grain size. The fine-grained alumina yielded the shortest cracks for both impact and quasi-static indentations. No difference in the relative ranking of materials has been detected for different crack sizes, suggesting that the evolution of impact or indentation produced cracks is not influenced by R curve behaviour for the aluminas tested. Radial crack lengths produced by quasi-static indentation and impacts are similar in length for equivalent crater diameters. The impact crater diameters have been successfully described by an analytical expression. RP ANDERSON, RM (reprint author), US BUR MINES,ALBANY RES CTR,1450 QUEEN AVE SW,ALBANY,OR 97321, USA. NR 26 TC 8 Z9 8 U1 0 U2 1 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE 1 PA PO BOX 564, 1001 LAUSANNE 1, SWITZERLAND SN 0043-1648 J9 WEAR JI Wear PD APR 13 PY 1993 VL 162 BP 1073 EP 1080 DI 10.1016/0043-1648(93)90126-7 PN B PG 8 WC Engineering, Mechanical; Materials Science, Multidisciplinary SC Engineering; Materials Science GA KZ108 UT WOS:A1993KZ10800066 ER PT J AU AJAYI, OO ERDEMIR, A HSIEH, JH ERCK, RA FENSKE, GR NICHOLS, FA AF AJAYI, OO ERDEMIR, A HSIEH, JH ERCK, RA FENSKE, GR NICHOLS, FA TI BOUNDARY FILM FOR STRUCTURAL CERAMIC MATERIALS SO WEAR LA English DT Article; Proceedings Paper CT 9TH INTERNATIONAL CONF ON WEAR OF MATERIALS CY APR 13-16, 1993 CL SAN FRANCISCO, CA ID SOFT METALLIC-FILMS; SILICON-NITRIDE; SILVER FILMS; TRIBOLOGICAL BEHAVIOR; ASSISTED DEPOSITION; SLIDING FRICTION; WEAR; LUBRICATION; ZIRCONIA AB Structural ceramic materials, like metals, will require lubrication if they are to be used extensively for tribological applications. The use of thin soft metallic coatings (specifically Ag) as a boundary film during mineral oil lubrication of silicon nitride (Si3N4) and zirconia (ZrO2) ceramic materials was investigated in this study. With a pin-on-flat contact configuration in reciprocating sliding, the steady friction coefficient was reduced by a factor of two (0.14-0.16 vs. 0.06-0.07) when the flats were coated with Ag. Also, with Ag coatings, the wear of pins was reduced to an unmeasurable level,whereas, in the absence of Ag coatings specific wear rates of about 2 X 10(-9)-4 x 10(-8) mm3 N-1 m-1 and about 7 X 10(-8)-2 X 10(-7) mm3 N-1 m-1 were measured for Si3N4 and ZrO2 pins respectively. In addition to preventing direct contact between pins and flats, thereby reducing wear, the Ag coatings also act as a solid lubricant, help dissipate flash heating, and accelerate modification of the lambda ratio. RP AJAYI, OO (reprint author), ARGONNE NATL LAB,DIV MAT & COMPONENTS TECHNOL,ARGONNE,IL 60439, USA. NR 26 TC 1 Z9 1 U1 0 U2 1 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE 1 PA PO BOX 564, 1001 LAUSANNE 1, SWITZERLAND SN 0043-1648 J9 WEAR JI Wear PD APR 13 PY 1993 VL 162 BP 1150 EP 1155 DI 10.1016/0043-1648(93)90134-8 PN B PG 6 WC Engineering, Mechanical; Materials Science, Multidisciplinary SC Engineering; Materials Science GA KZ108 UT WOS:A1993KZ10800074 ER PT J AU MAGRUDER, RH YANG, L HAGLUND, RF WHITE, CW YANG, L DORSINVILLE, R ALFANO, RR AF MAGRUDER, RH YANG, L HAGLUND, RF WHITE, CW YANG, L DORSINVILLE, R ALFANO, RR TI OPTICAL-PROPERTIES OF GOLD NANOCLUSTER COMPOSITES FORMED BY DEEP ION-IMPLANTATION IN SILICA SO APPLIED PHYSICS LETTERS LA English DT Article ID PHASE CONJUGATION; PARTICLES; SIZE AB Planar layers of Au clusters with diameters between 5 and 30 nm were synthesized by implanting 2.75-MeV Au+ ions in fused silica. The metal-glass composite layer was 0.85 mum below the surface and had a width of 0.5 mum. Thermal annealing enhanced the optical absorption of the annealed samples near 2.4 eV. The third-order nonlinear optical response time is less-than-or-equal-to 35 ps; the magnitude of the effective nonlinear susceptibility is 200 times that of similar clusters embedded in ruby-gold melt glass. C1 VANDERBILT UNIV,DEPT PHYS & ASTRON,NASHVILLE,TN 37235. OAK RIDGE NATL LAB,DIV SOLID STATE,OAK RIDGE,TN 37831. CUNY CITY COLL,CTR ANAL STRUCT & INTERFACES,INST ULTRAFAST SPECTROSCOPY & LASERS,NEW YORK,NY 10031. CUNY CITY COLL,DEPT ELECT ENGN,NEW YORK,NY 10031. CUNY CITY COLL,DEPT PHYS,NEW YORK,NY 10031. RP MAGRUDER, RH (reprint author), VANDERBILT UNIV,DEPT MAT SCI & ENGN,NASHVILLE,TN 37235, USA. NR 18 TC 142 Z9 143 U1 2 U2 18 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD APR 12 PY 1993 VL 62 IS 15 BP 1730 EP 1732 DI 10.1063/1.109588 PG 3 WC Physics, Applied SC Physics GA KW464 UT WOS:A1993KW46400008 ER PT J AU GOURLEY, PL TIGGES, CP SCHNEIDER, RP BRENNAN, TM HAMMONS, BE MCDONALD, AE AF GOURLEY, PL TIGGES, CP SCHNEIDER, RP BRENNAN, TM HAMMONS, BE MCDONALD, AE TI OPTICAL-PROPERTIES OF FRACTAL QUANTUM-WELLS SO APPLIED PHYSICS LETTERS LA English DT Article ID FIBONACCI SUPERLATTICE; ELECTRONIC-PROPERTIES AB We report the growth of new fractal quantum-well structures and the first studies of their optical properties. In these (Al,Ga)As structures the composition is varied in a fractal sequence between layers to create a highly branched, self-similar distribution of quantum wells. Experimentally, we studied optical absorption, luminescence and excitation spectra, and electron-hole recombination dynamics. We computed the electron and hole wave functions and transition energies and found good agreement with experiment. The optical and transport properties are strikingly different from those in single or periodic quantum wells. First, the band-edge absorption slope (change in optical density per unit energy) can be controlled over wide limits simply by modifying the sequence. Second, the transport of carriers across the quantum-well layers can be adjusted to control the carrier relaxation rate and energy distribution within the quantum wells. These results suggest possible applications of these new materials for several new devices including broadband emitters, solar cells, electro-optical, and nonlinear optical devices. RP GOURLEY, PL (reprint author), SANDIA NATL LABS,ALBUQUERQUE,NM 87185, USA. NR 9 TC 8 Z9 8 U1 1 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 APR 12 PY 1993 VL 62 IS 15 BP 1736 EP 1738 DI 10.1063/1.109590 PG 3 WC Physics, Applied SC Physics GA KW464 UT WOS:A1993KW46400010 ER PT J AU STEARNS, DG AF STEARNS, DG TI STOCHASTIC-MODEL FOR THIN-FILM GROWTH AND EROSION SO APPLIED PHYSICS LETTERS LA English DT Article ID X-RAY MIRRORS; MULTILAYER AB A linearized, stochastic theory of thin film growth and erosion is presented to describe the evolution of surface roughness in the case of good layer formation far from equilibrium, as is generally found in energetic growth techniques such as ion-assisted vapor deposition. The variation of the power spectral density and root-mean-square roughness is studied for growth on smooth and rough substrates. RP STEARNS, DG (reprint author), LAWRENCE LIVERMORE NATL LAB,POB 808,LIVERMORE,CA 94550, USA. NR 14 TC 71 Z9 71 U1 0 U2 5 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD APR 12 PY 1993 VL 62 IS 15 BP 1745 EP 1747 DI 10.1063/1.109593 PG 3 WC Physics, Applied SC Physics GA KW464 UT WOS:A1993KW46400013 ER PT J AU BAI, GR CHANG, HLM LAM, DJ GAO, Y AF BAI, GR CHANG, HLM LAM, DJ GAO, Y TI PREPARATION AND STRUCTURE OF PBZRO3 EPITAXIAL-FILMS BY METALORGANIC CHEMICAL VAPOR-DEPOSITION SO APPLIED PHYSICS LETTERS LA English DT Article AB Single-crystal PbZrO3 thin films have been grown on (001) SrTiO3 substrates by metalorganic chemical vapor deposition. The single-crystal nature of c-axis oriented PbZrO3 film is confirmed by x-ray diffraction, selective area electron diffraction, and transmission electron microscopy. The epitaxial relationship between the PbZrO3 film and the SrTiO3 substrate was found to be (001)[100]PbZrO3\\ (001)[110]SrTiO3. C1 NEW MEXICO INST MIN & TECHNOL,DEPT MAT & MET ENGN,SOCORRO,NM 87801. RP BAI, GR (reprint author), ARGONNE NATL LAB,DIV MAT SCI,ARGONNE,IL 60439, USA. NR 8 TC 44 Z9 46 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 APR 12 PY 1993 VL 62 IS 15 BP 1754 EP 1756 DI 10.1063/1.109596 PG 3 WC Physics, Applied SC Physics GA KW464 UT WOS:A1993KW46400016 ER PT J AU ARENT, DJ BODE, M BERTNESS, KA KURTZ, SR OLSON, JM AF ARENT, DJ BODE, M BERTNESS, KA KURTZ, SR OLSON, JM TI BAND-GAP NARROWING IN ORDERED GA0.47IN0.53AS SO APPLIED PHYSICS LETTERS LA English DT Article ID ALLOYS; GA0.5IN0.5P; GROWTH; LAYERS; STRAIN AB We report the first observation of band-gap energy reduction in Ga0.47In0.53As deposited on (100) InP by atmospheric pressure organometallic vapor phase epitaxy due to CuPt-type ordering. A reduction of more than 65 meV in the band-gap energy is observed for lattice-matched samples that show strong CuPt-like ordering by transmission electron microscopy. By comparison samples that show no CuPt-like ordering diffraction signatures, do not have reduced band-gap energies. Studies of the influence of growth parameters on the band-gap energy indicate a U-shaped dependence on the growth temperature with a minimum around 550-degrees-C and decreasing band-gap energies with increasing growth rate (at a constant V/III ratio) over the range 0.5-4 mum/h. RP ARENT, DJ (reprint author), NATL RENEWABLE ENERGY LAB,1617 COLE BLVD,GOLDEN,CO 80401, USA. NR 20 TC 45 Z9 45 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 APR 12 PY 1993 VL 62 IS 15 BP 1806 EP 1808 DI 10.1063/1.109640 PG 3 WC Physics, Applied SC Physics GA KW464 UT WOS:A1993KW46400034 ER PT J AU BUDAI, JD YOUNG, RT CHAO, BS AF BUDAI, JD YOUNG, RT CHAO, BS TI INPLANE EPITAXIAL ALIGNMENT OF YBA2CU3O7-X FILMS GROWN ON SILVER CRYSTALS AND BUFFER LAYERS SO APPLIED PHYSICS LETTERS LA English DT Article ID THIN-FILMS; SUBSTRATE; ENHANCEMENT; BOUNDARIES; CERAMICS AB Superconducting YBa2Cu3O7-x (YBCO) films were grown by laser ablation on Ag(001), Ag (110), and Ag (111) single-crystal surfaces. X-ray diffraction measurements showed that, in all cases, the films were aligned with specific in-plane epitaxial orientation with respect to the crystallographic axes of the substrate. The observed orientations were consistent with predictions of near-coincident site lattice models of the YBCO-Ag interface. This technique for achieving three-dimensional film alignment was extended to include a Ag epitaxial buffer layer on mica in place of a bulk Ag crystal. In-plane epitaxial alignment on metal substrates and buffer layers has important consequences in practical applications for inhibiting weak-link behavior caused by high-angle grain boundaries. C1 ENERGY CONVERS DEVICES INC,TROY,MI 48084. RP BUDAI, JD (reprint author), OAK RIDGE NATL LAB,DIV SOLID STATE,POB 2008,OAK RIDGE,TN 37831, USA. RI Budai, John/R-9276-2016 OI Budai, John/0000-0002-7444-1306 NR 16 TC 72 Z9 78 U1 1 U2 6 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD APR 12 PY 1993 VL 62 IS 15 BP 1836 EP 1838 DI 10.1063/1.109565 PG 3 WC Physics, Applied SC Physics GA KW464 UT WOS:A1993KW46400044 ER PT J AU BAKTASH, C NAZAREWICZ, W WYSS, R AF BAKTASH, C NAZAREWICZ, W WYSS, R TI ON THE QUESTION OF SPIN FITTING AND QUANTIZED ALIGNMENT IN ROTATIONAL BANDS SO NUCLEAR PHYSICS A LA English DT Review ID IDENTICAL SUPERDEFORMED BANDS; INTRINSIC STATES; HG NUCLEI; SHAPES; KR-78; PSEUDOSPIN; ENERGIES; MOMENTS; INERTIA; REGION AB Several methods employed to parametrize the spins of the superdeformed bands in terms of their observed gamma-ray energies are closely examined. It is pointed out that, since the proposed fitting procedures are variants of the Harris expansion formula, it is questionable if they could be applied to determine the unknown spins of the excited bands due to the possible presence of non-zero initial alignments. A comprehensive study of the normally deformed excited bands indicates that no correlation exists between the fitted spins and the experimentally known values. By analogy, we may conclude that there is no firm evidence for the presence of anomalous relative alignments between the superdeformed identical bands in the Hg region. Additionally, a critical review of several of the models and scenarios that purport to explain the origin of the identical bands, or the patterns of the fitted alignments is presented. It is concluded that none of these models can satisfactorily explain the identical moments of inertia in neighboring nuclei and the systematics of the observed or fitted alignments. Thus, the important question of the microscopic origin of the identical bands remains to be investigated. C1 OAK RIDGE NATL LAB,JOINT INST HEAVY ION RES,OAK RIDGE,TN 37831. UNIV WARSAW,INST THEORET PHYS,PL-00681 WARSAW,POLAND. WARSAW UNIV TECHNOL,INST PHYS,PL-00662 WARSAW,POLAND. RP BAKTASH, C (reprint author), OAK RIDGE NATL LAB,DIV PHYS,BLDG 6000,POB 2008,OAK RIDGE,TN 37831, USA. NR 105 TC 20 Z9 21 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 APR 12 PY 1993 VL 555 IS 2 BP 375 EP 407 DI 10.1016/0375-9474(93)90293-7 PG 33 WC Physics, Nuclear SC Physics GA LH175 UT WOS:A1993LH17500003 ER PT J AU HASENFRATZ, A JANSEN, K SHEN, Y AF HASENFRATZ, A JANSEN, K SHEN, Y TI THE PHASE-DIAGRAM OF A U(1) HIGGS-YUKAWA MODEL AT FINITE LAMBDA SO NUCLEAR PHYSICS B LA English DT Article ID SCALAR-FERMION MODEL; LATTICE; FIELD AB In this paper we investigate how the phase diagram of a U(1) symmetry Higgs-Yukawa system depends on the scalar self-coupling lambda. The phase diagram of similar models with continuous symmetry were extensively studied in the infinite scalar self-coupling lambda = infinity limit. Recent analytical and numerical calculations at zero self-coupling showed qualitatively different phase diagram, raising the question of the lambda-dependence of the phase diagram. Here we use analytical (large-N(f), perturbative and mean-field) approximations as well as numerical simulations to investigate the system. C1 UNIV CALIF SAN DIEGO,DEPT PHYS,LA JOLLA,CA 92093. BROOKHAVEN NATL LAB,DEPT PHYS,UPTON,NY 11973. RP HASENFRATZ, A (reprint author), UNIV ARIZONA,DEPT PHYS,TUCSON,AZ 85721, USA. NR 12 TC 6 Z9 6 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 APR 12 PY 1993 VL 394 IS 2 BP 527 EP 540 DI 10.1016/0550-3213(93)90024-J PG 14 WC Physics, Particles & Fields SC Physics GA KY364 UT WOS:A1993KY36400010 ER PT J AU DODELSON, S JUBAS, JM AF DODELSON, S JUBAS, JM TI MICROWAVE ANISOTROPIES IN THE LIGHT OF THE DATA FROM THE COBE SATELLITE SO PHYSICAL REVIEW LETTERS LA English DT Article ID PRIMORDIAL NUCLEOSYNTHESIS; BACKGROUND-RADIATION; EXPANDING UNIVERSE; FLUCTUATIONS; MATTER AB The recent measurement of anisotropies in the cosmic microwave background by the Cosmic Background Explorer (COBE) satellite and the recent South Pole experiment offer an excellent opportunity to probe cosmological theories. We test a class of theories in which the Universe today is flat and matter dominated, and primordial perturbations are adiabatic parameterized by an index n. In this class of theories the predicted signal in the South Pole experiment depends on n, the Hubble constant, and the baryon density. For n = 1 a large region of this parameter space is rule out, but there is still a window open which satisfies constraints from COBE, the South Pole experiment, and big bang nucleosynthesis. C1 MIT,DEPT PHYS,CAMBRIDGE,MA 02139. RP DODELSON, S (reprint author), FERMILAB NATL ACCELERATOR LAB,NASA FERMILAB ASTROPHYS CTR,POB 500,BATAVIA,IL 60510, USA. NR 18 TC 47 Z9 47 U1 0 U2 0 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 APR 12 PY 1993 VL 70 IS 15 BP 2224 EP 2227 DI 10.1103/PhysRevLett.70.2224 PG 4 WC Physics, Multidisciplinary SC Physics GA KW756 UT WOS:A1993KW75600007 ER PT J AU ABE, F ALBROW, M AMIDEI, D ANWAYWIESE, C APOLLINARI, G ATAC, M AUCHINCLOSS, P AZZI, P BADEN, AR BACCHETTA, N BADGETT, W BAILEY, MW BAMBERGER, A DEBARBARO, P BARBAROGALTIERI, A BARNES, VE BARNETT, BA BAUER, G BAUMANN, T BEDESCHI, F BEHRENDS, S BELFORTE, S BELLETTINI, G BELLINGER, J BENJAMIN, D BENLLOCH, J BENSINGER, J BERETVAS, A BERGE, JP BERTOLUCCI, S BIERY, K BHADRA, S BINKLEY, M BISELLO, D BLAIR, R BLOCKER, C BODEK, A BOLOGNESI, V BOOTH, AW BOSWELL, C BRANDENBURG, G BROWN, D BUCKLEYGEER, E BUDD, HS BUSETTO, G BYONWAGNER, A BYRUM, KL CAMPAGNARI, C CAMPBELL, M CANER, A CAREY, R CARITHERS, W CARLSMITH, D CARROLL, JT CASHMORE, R CASTRO, A CERVELLI, F CHADWICK, K CHAPMAN, J CHIARELLI, G CHINOWSKY, W CIHANGIR, S CLARK, AG COBAL, M CONNOR, D CONTRERAS, M COOPER, J CORDELLI, M CRANE, D CUNNINGHAM, JD DAY, C DEJONGH, F DELLAGNELLO, S DELLORSO, M DEMORTIER, L DENBY, B DERWENT, PF DEVLIN, T DIBITONTO, D DICKSON, M DRUCKER, RB EINSWEILER, K ELIAS, JE ELY, R ENO, S ERREDE, S ETCHEGOYEN, A FARHAT, B FELDMAN, GJ FLAUGHER, B FOSTER, GW FRANKLIN, M FREEMAN, J FRISCH, H FUESS, T FUKUI, Y GARFINKEL, AF GAUTHIER, A GEER, S GERDES, DW GIANNETTI, P GIOKARIS, N GIROMINI, P GLADNEY, L GOLD, M GONZALEZ, J GOULIANOS, K GRASSMANN, H GRIECO, GM GRINDLEY, R GROSSOPILCHER, C HABER, C HAHN, SR HANDLER, R HARA, K HARRAL, B HARRIS, RM HAUGER, SA HAUSER, J HAWK, C HESSING, T HOLLEBEEK, R HOLLOWAY, L HONG, S HOUK, G HU, P HUBBARD, B HUFFMAN, BT HUGHES, R HURST, P HUTH, J HYLEN, J INCAGLI, M INO, T ISO, H JENSEN, H JESSOP, CP JOHNSON, RP JOSHI, U KADEL, RW KAMON, T KANDA, S KARDELIS, DA KARLINER, I KEARNS, E KEEBLE, L KEPHART, R KESTEN, P KEUP, RM KEUTELIAN, H KIM, D KIM, SB KIM, SH KIM, YK KIRSCH, L KONDO, K KONIGSBERG, J KORDAS, K KOVACS, E KRASBERG, M KUHLMANN, SE KUNS, E LAASANEN, AT LAMMEL, S LAMOUREUX, JI LEONE, S LEWIS, JD LI, W LIMON, P LINDGREN, M LISS, TM LOCKYER, N LORETI, M LOW, EH LUCCHESI, D LUCHINI, CB LUKENS, P MAAS, P MAESHIMA, K MANGANO, M MARRINER, JP MARIOTTI, M MARKELOFF, R MARKOSKY, LA MATTINGLY, R MCINTYRE, P MENZIONE, A MESCHI, E MEYER, T MIKAMO, S MILLER, M MIMASHI, T MISCETTI, S MISHINA, M MIYASHITA, S MORITA, Y MOULDING, S MUELLER, J MUKHERJEE, A MULLER, T NAKAE, LF NAKANO, I NELSON, C NEUBERGER, D NEWMANHOLMES, C NG, JST NINOMIYA, M NODULMAN, L OGAWA, S PAOLETTI, R PAPADIMITRIOU, V PARA, A PARE, E PARK, S PATRICK, J PAULETTA, G PESCARA, L PHILLIPS, TJ PTOHOS, F PLUNKETT, R PONDROM, L PROUDFOOT, J PUNZI, G QUARRIE, D RAGAN, K REDLINGER, G RHOADES, J ROACH, M RIMONDI, F RISTORI, L ROBERTSON, WJ RODRIGO, T ROHALY, T ROODMAN, A SAKUMOTO, WK SANSONI, A SARD, RD SAVOYNAVARRO, A SCARPINE, V SCHLABACH, P SCHMIDT, EE SCHNEIDER, O SCHUB, MH SCHWITTERS, R SCRIBANO, A SEGLER, S SEIYA, Y SGANOS, G SHAPIRO, M SHAW, NM SHEAFF, M SHOCHET, M SIEGRIST, J SILL, A SINERVO, P SKARHA, J SLIWA, K SMITH, DA SNIDER, FD SONG, L SONG, T SPAHN, M SPIES, A SPHICAS, P STDENIS, R STANCO, L STEFANINI, A SULLIVAN, G SUMOROK, K SWARTZ, RL TAKANO, M TAKIKAWA, K TAREM, S TARTARELLI, F TETHER, S THERIOT, D TIMKO, M TIPTON, P TKACZYK, S TOLLESTRUP, A TONNISON, J TRISCHUK, W TSAY, Y TSENG, J TURINI, N UKEGAWA, F UNDERWOOD, D VEJCIK, S VIDAL, R WAGNER, RG WAGNER, RL WAINER, N WALKER, RC WALSH, J WATTS, G WATTS, T WEBB, R WENDT, C WENZEL, H WESTER, WC WESTHUSING, T WHITE, SN WICKLUND, AB WICKLUND, E WILLIAMS, HH WINER, BL WOLINSKI, J WU, DY WYSS, J YAGIL, A YASUOKA, K YE, Y YEH, GP YI, C YOH, J YOKOYAMA, M YUN, JC ZANETTI, A ZETTI, F ZHANG, S ZHANG, W ZUCCHELLI, S AF ABE, F ALBROW, M AMIDEI, D ANWAYWIESE, C APOLLINARI, G ATAC, M AUCHINCLOSS, P AZZI, P BADEN, AR BACCHETTA, N BADGETT, W BAILEY, MW BAMBERGER, A DEBARBARO, P BARBAROGALTIERI, A BARNES, VE BARNETT, BA BAUER, G BAUMANN, T BEDESCHI, F BEHRENDS, S BELFORTE, S BELLETTINI, G BELLINGER, J BENJAMIN, D BENLLOCH, J BENSINGER, J BERETVAS, A BERGE, JP BERTOLUCCI, S BIERY, K BHADRA, S BINKLEY, M BISELLO, D BLAIR, R BLOCKER, C BODEK, A BOLOGNESI, V BOOTH, AW BOSWELL, C BRANDENBURG, G BROWN, D BUCKLEYGEER, E BUDD, HS BUSETTO, G BYONWAGNER, A BYRUM, KL CAMPAGNARI, C CAMPBELL, M CANER, A CAREY, R CARITHERS, W CARLSMITH, D CARROLL, JT CASHMORE, R CASTRO, A CERVELLI, F CHADWICK, K CHAPMAN, J CHIARELLI, G CHINOWSKY, W CIHANGIR, S CLARK, AG COBAL, M CONNOR, D CONTRERAS, M COOPER, J CORDELLI, M CRANE, D CUNNINGHAM, JD DAY, C DEJONGH, F DELLAGNELLO, S DELLORSO, M DEMORTIER, L DENBY, B DERWENT, PF DEVLIN, T DIBITONTO, D DICKSON, M DRUCKER, RB EINSWEILER, K ELIAS, JE ELY, R ENO, S ERREDE, S ETCHEGOYEN, A FARHAT, B FELDMAN, GJ FLAUGHER, B FOSTER, GW FRANKLIN, M FREEMAN, J FRISCH, H FUESS, T FUKUI, Y GARFINKEL, AF GAUTHIER, A GEER, S GERDES, DW GIANNETTI, P GIOKARIS, N GIROMINI, P GLADNEY, L GOLD, M GONZALEZ, J GOULIANOS, K GRASSMANN, H GRIECO, GM GRINDLEY, R GROSSOPILCHER, C HABER, C HAHN, SR HANDLER, R HARA, K HARRAL, B HARRIS, RM HAUGER, SA HAUSER, J HAWK, C HESSING, T HOLLEBEEK, R HOLLOWAY, L HONG, S HOUK, G HU, P HUBBARD, B HUFFMAN, BT HUGHES, R HURST, P HUTH, J HYLEN, J INCAGLI, M INO, T ISO, H JENSEN, H JESSOP, CP JOHNSON, RP JOSHI, U KADEL, RW KAMON, T KANDA, S KARDELIS, DA KARLINER, I KEARNS, E KEEBLE, L KEPHART, R KESTEN, P KEUP, RM KEUTELIAN, H KIM, D KIM, SB KIM, SH KIM, YK KIRSCH, L KONDO, K KONIGSBERG, J KORDAS, K KOVACS, E KRASBERG, M KUHLMANN, SE KUNS, E LAASANEN, AT LAMMEL, S LAMOUREUX, JI LEONE, S LEWIS, JD LI, W LIMON, P LINDGREN, M LISS, TM LOCKYER, N LORETI, M LOW, EH LUCCHESI, D LUCHINI, CB LUKENS, P MAAS, P MAESHIMA, K MANGANO, M MARRINER, JP MARIOTTI, M MARKELOFF, R MARKOSKY, LA MATTINGLY, R MCINTYRE, P MENZIONE, A MESCHI, E MEYER, T MIKAMO, S MILLER, M MIMASHI, T MISCETTI, S MISHINA, M MIYASHITA, S MORITA, Y MOULDING, S MUELLER, J MUKHERJEE, A MULLER, T NAKAE, LF NAKANO, I NELSON, C NEUBERGER, D NEWMANHOLMES, C NG, JST NINOMIYA, M NODULMAN, L OGAWA, S PAOLETTI, R PAPADIMITRIOU, V PARA, A PARE, E PARK, S PATRICK, J PAULETTA, G PESCARA, L PHILLIPS, TJ PTOHOS, F PLUNKETT, R PONDROM, L PROUDFOOT, J PUNZI, G QUARRIE, D RAGAN, K REDLINGER, G RHOADES, J ROACH, M RIMONDI, F RISTORI, L ROBERTSON, WJ RODRIGO, T ROHALY, T ROODMAN, A SAKUMOTO, WK SANSONI, A SARD, RD SAVOYNAVARRO, A SCARPINE, V SCHLABACH, P SCHMIDT, EE SCHNEIDER, O SCHUB, MH SCHWITTERS, R SCRIBANO, A SEGLER, S SEIYA, Y SGANOS, G SHAPIRO, M SHAW, NM SHEAFF, M SHOCHET, M SIEGRIST, J SILL, A SINERVO, P SKARHA, J SLIWA, K SMITH, DA SNIDER, FD SONG, L SONG, T SPAHN, M SPIES, A SPHICAS, P STDENIS, R STANCO, L STEFANINI, A SULLIVAN, G SUMOROK, K SWARTZ, RL TAKANO, M TAKIKAWA, K TAREM, S TARTARELLI, F TETHER, S THERIOT, D TIMKO, M TIPTON, P TKACZYK, S TOLLESTRUP, A TONNISON, J TRISCHUK, W TSAY, Y TSENG, J TURINI, N UKEGAWA, F UNDERWOOD, D VEJCIK, S VIDAL, R WAGNER, RG WAGNER, RL WAINER, N WALKER, RC WALSH, J WATTS, G WATTS, T WEBB, R WENDT, C WENZEL, H WESTER, WC WESTHUSING, T WHITE, SN WICKLUND, AB WICKLUND, E WILLIAMS, HH WINER, BL WOLINSKI, J WU, DY WYSS, J YAGIL, A YASUOKA, K YE, Y YEH, GP YI, C YOH, J YOKOYAMA, M YUN, JC ZANETTI, A ZETTI, F ZHANG, S ZHANG, W ZUCCHELLI, S TI MEASUREMENT OF THE CROSS-SECTION FOR PRODUCTION OF 2 ISOLATED PROMPT PHOTONS IN P(P)OVER-BAR COLLISIONS AT ROOT-S=1.8 TEV SO PHYSICAL REVIEW LETTERS LA English DT Article ID MASS AB We present measurements from events with two isolated prompt photons in ppBAR collisions at square-root s=1.8 TeV. The differential cross section, measured as a function of transverse momentum (P(T)) of each photon, is about 3 times what next-to-leading-order QCD calculations predict. The cross section for photons with P(T) in the range 10-19 GeV is 86 +/- 27(stat)-23(+32)(syst) pb. We also study the correlation between the two photons in both azimuthal angle and P(T). The magnitude of the vector sum of the transverse momenta of both photons, K(T)=\P(T1) + P(T2)\, has a mean value of [K(T)]=5.1 +/- 1.1 GeV. C1 ARGONNE NATL LAB,ARGONNE,IL 60439. BRANDEIS UNIV,WALTHAM,MA 02254. UNIV CALIF LOS ANGELES,LOS ANGELES,CA 90024. DUKE UNIV,DURHAM,NC 27706. FERMILAB NATL ACCELERATOR LAB,BATAVIA,IL 60510. IST NAZL FIS NUCL,LAB NAZL FRASCATI,FRASCATI,ITALY. HARVARD UNIV,CAMBRIDGE,MA 02138. UNIV ILLINOIS,URBANA,IL 61801. JOHNS HOPKINS UNIV,BALTIMORE,MD 21218. LAWRENCE BERKELEY LAB,BERKELEY,CA 94720. MIT,CAMBRIDGE,MA 02139. UNIV MICHIGAN,ANN ARBOR,MI 48109. UNIV PADUA,IST NAZL FIS NUCL,SEZ PADOVA,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. PURDUE UNIV,W LAFAYETTE,IN 47907. UNIV ROCHESTER,ROCHESTER,NY 14627. ROCKEFELLER UNIV,NEW YORK,NY 10021. RUTGERS STATE UNIV,PISCATAWAY,NJ 08854. TEXAS A&M UNIV SYST,COLL STN,TX 77843. UNIV TSUKUBA,TSUKUBA,IBARAKI 305,JAPAN. TUFTS UNIV,MEDFORD,MA 02155. UNIV WISCONSIN,MADISON,WI 53706. UNIV CHICAGO,CHICAGO,IL 60637. RP ABE, F (reprint author), NATL LAB HIGH ENERGY PHYS,TSUKUBA,IBARAKI 305,JAPAN. RI St.Denis, Richard/C-8997-2012; Chiarelli, Giorgio/E-8953-2012; Azzi, Patrizia/H-5404-2012; Punzi, Giovanni/J-4947-2012; Kim, Soo-Bong/B-7061-2014 OI Chiarelli, Giorgio/0000-0001-9851-4816; Azzi, Patrizia/0000-0002-3129-828X; Punzi, Giovanni/0000-0002-8346-9052; NR 11 TC 32 Z9 32 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 APR 12 PY 1993 VL 70 IS 15 BP 2232 EP 2236 DI 10.1103/PhysRevLett.70.2232 PG 5 WC Physics, Multidisciplinary SC Physics GA KW756 UT WOS:A1993KW75600009 ER PT J AU LEE, TSH RISKA, DO AF LEE, TSH RISKA, DO TI SHORT-RANGE EXCHANGE CONTRIBUTIONS TO THE CROSS-SECTION FOR PP-]PP-PI(0) NEAR THRESHOLD SO PHYSICAL REVIEW LETTERS LA English DT Article ID P+P->P+P+PI-0; NUCLEI AB The nuclear S-wave pion production is described by the axial charge density operator of the two-nucleon system, It is shown that the short range axial exchange charge operator implied by the nucleon-nucleon interaction enhances the predicted cross section for the reaction pp--> pppi0 near threshold by factors 3-5. This suffices to explain most of the underprediction obtained with the single-nucleon and S-wave pion rescattering operator. The result implies that the cross section for pp--> pppi0 can provide direct information on the short range components of the nucleon-nucleon interaction. C1 UNIV HELSINKI,DEPT PHYS,SF-00170 HELSINKI 17,FINLAND. RP LEE, TSH (reprint author), ARGONNE NATL LAB,DIV PHYS,ARGONNE,IL 60439, USA. NR 22 TC 161 Z9 161 U1 0 U2 0 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 APR 12 PY 1993 VL 70 IS 15 BP 2237 EP 2240 DI 10.1103/PhysRevLett.70.2237 PG 4 WC Physics, Multidisciplinary SC Physics GA KW756 UT WOS:A1993KW75600010 ER PT J AU LESTONE, JP AF LESTONE, JP TI DETERMINATION OF THE TIME EVOLUTION OF FISSION FROM PARTICLE-EMISSION SO PHYSICAL REVIEW LETTERS LA English DT Article ID NUCLEI; SCALES; MODEL AB Recently measured properties of the prescission particle emission from heavy-ion induced fission of systems with A approximately 200 were analyzed using the statistical model. Simultaneous fits to prescission neutron, proton, and a-particle multiplicities and mean kinetic energies can be obtained when the deformation dependence of both the particle transmission coefficients and particle binding energies are taken into account. The experimental data are consistent with a total fission time scale of (30 +/- 10) x 10(-21) s, with more than half of this time being spent beyond the saddle point. RP LESTONE, JP (reprint author), LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545, USA. NR 22 TC 86 Z9 86 U1 0 U2 0 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 APR 12 PY 1993 VL 70 IS 15 BP 2245 EP 2248 DI 10.1103/PhysRevLett.70.2245 PG 4 WC Physics, Multidisciplinary SC Physics GA KW756 UT WOS:A1993KW75600012 ER PT J AU MAXON, S ESTABROOK, KG PRASAD, MK OSTERHELD, AL LONDON, RA EDER, DC AF MAXON, S ESTABROOK, KG PRASAD, MK OSTERHELD, AL LONDON, RA EDER, DC TI HIGH-GAIN X-RAY LASERS AT THE WATER WINDOW SO PHYSICAL REVIEW LETTERS LA English DT Article ID AMPLIFICATION; DESIGN; IONS AB We propose a scheme for producing a spatial and temporal averaged gain of 45 cm-1 in nickel-like Ta, including refraction. This result is achieved by irradiating a 40 mug/cm2 target with a low intensity pulse [2omega(lambda=0.53 mum), 5x10(13) W/cm2, 80 ps] to make the plasma subcritical. This is followed by a high intensity pulse (2omega, 2x10(15), 20 ps) to give the proper ionization. Therefore the principle of pulse shaping to achieve high gain using high intensity pump radiation is demonstrated. RP MAXON, S (reprint author), LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550, USA. NR 26 TC 42 Z9 43 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 APR 12 PY 1993 VL 70 IS 15 BP 2285 EP 2288 DI 10.1103/PhysRevLett.70.2285 PG 4 WC Physics, Multidisciplinary SC Physics GA KW756 UT WOS:A1993KW75600022 ER PT J AU JESSON, DE PENNYCOOK, SJ TISCHLER, JZ BUDAI, JD BARIBEAU, JM HOUGHTON, DC AF JESSON, DE PENNYCOOK, SJ TISCHLER, JZ BUDAI, JD BARIBEAU, JM HOUGHTON, DC TI INTERPLAY BETWEEN EVOLVING SURFACE-MORPHOLOGY, ATOMIC-SCALE GROWTH MODES, AND ORDERING DURING SIXGE1-X EPITAXY SO PHYSICAL REVIEW LETTERS LA English DT Article ID SCANNING-TUNNELING-MICROSCOPY; SI(001); SI(100); SILICON; ENERGY; SI AB Atomic-scale compositional ordering in SixGe1-x alloys is directly linked to the formation of coherent islands during Stranski-Krastanow growth. The vicinal surfaces associated with nonequilibrium island shapes induce a bilayer step flow growth mode, and the ordering results from Ge segregation at D(B) kinks. C1 NATL RES COUNCIL CANADA,INST MICROSTRUCT SCI,OTTAWA K1A 0R6,ONTARIO,CANADA. RP JESSON, DE (reprint author), OAK RIDGE NATL LAB,DIV SOLID STATE,OAK RIDGE,TN 37831, USA. RI Budai, John/R-9276-2016; OI Budai, John/0000-0002-7444-1306; Jesson, David/0000-0003-0897-1445 NR 21 TC 39 Z9 39 U1 0 U2 7 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 APR 12 PY 1993 VL 70 IS 15 BP 2293 EP 2296 DI 10.1103/PhysRevLett.70.2293 PG 4 WC Physics, Multidisciplinary SC Physics GA KW756 UT WOS:A1993KW75600024 ER PT J AU DU, Q SUPERFINE, R FREYSZ, E SHEN, YR AF DU, Q SUPERFINE, R FREYSZ, E SHEN, YR TI VIBRATIONAL SPECTROSCOPY OF WATER AT THE VAPOR WATER INTERFACE SO PHYSICAL REVIEW LETTERS LA English DT Article ID INFRARED PREDISSOCIATION SPECTRA; 2ND-HARMONIC GENERATION; MOLECULAR-DYNAMICS; SURFACE; ORIENTATION; INTENSITIES AB Using infrared-visible sum-frequency generation we have obtained the OH stretch vibrational spectra of water at the vapor/water interface. From the spectra, we deduce that more than 20% of the surface water molecules have one free OH projecting into the vapor. The spectrum is weakly temperature dependent from 10 to 80-degrees-C. A monolayer of fatty alcohol on water surface terminates the free OH groups and induces an icelike structure in the spectrum. C1 LAWRENCE BERKELEY LAB,DIV CHEM SCI,BERKELEY,CA 94720. UNIV BORDEAUX 1,CTR PHYS MOLEC,F-33405 TALENCE,FRANCE. RP DU, Q (reprint author), UNIV CALIF BERKELEY,DEPT PHYS,BERKELEY,CA 94720, USA. RI Superfine, Richard/A-1968-2012 NR 31 TC 674 Z9 678 U1 17 U2 134 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 APR 12 PY 1993 VL 70 IS 15 BP 2313 EP 2316 DI 10.1103/PhysRevLett.70.2313 PG 4 WC Physics, Multidisciplinary SC Physics GA KW756 UT WOS:A1993KW75600029 ER PT J AU RAMSHAW, JD AF RAMSHAW, JD TI H-THEOREMS FOR THE TSALLIS AND RENYI ENTROPIES SO PHYSICS LETTERS A LA English DT Article ID IRREVERSIBILITY AB Mariz [Phys. Lett. A 165 (1992) 409] recently analyzed the time evolution of the Tsallis entropy S(q)T and the Renyi entropy S(q)R based on the master equation and the assumption of detailed balance. Mariz restricted attention to situations where the equilibrium probability distribution is uniform, for which he showed that dS(q)T/dt and dS(q)R/dt have the same sign as the parameter q. Here we show that these results continue to hold in the absence of detailed balance. We also present the generalization to cases with nonuniform equilibrium distributions, for which it is necessary to appropriately redefine the entropy relative to equilibrium. RP RAMSHAW, JD (reprint author), EG&G IDAHO INC,IDAHO NATL ENGN LAB,POB 1625,IDAHO FALLS,ID 83415, USA. NR 7 TC 83 Z9 84 U1 1 U2 3 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 APR 12 PY 1993 VL 175 IS 3-4 BP 169 EP 170 DI 10.1016/0375-9601(93)90820-P PG 2 WC Physics, Multidisciplinary SC Physics GA KX664 UT WOS:A1993KX66400005 ER PT J AU RAMSHAW, JD AF RAMSHAW, JD TI IRREVERSIBILITY AND GENERALIZED ENTROPIES SO PHYSICS LETTERS A LA English DT Article AB The time evolution of the Tsallis (T) and Renyi (R) entropies for a discrete state space was recently analyzed by Mariz [Phys. Lett. A 165 (1992) 409] and Ramshaw [Phys. Lett. A 175 (1993) 169] based on the master equation. Here we perform a corresponding analysis for a continuous state space x in which the probability distribution rho(x, t) obeys the generalized Liouville equation. For this purpose it is necessary to formulate properly covariant generalizations of the T and R entropies in terms of rho(x, t). We show that if the microscopic dynamics is reversible in the Poincare-Lyapunov sense (i.e., D(x) = 0, where D(x) is the covariant divergence of the flow velocity in state space) then both the T and R entropies are constant in time, just like the conventional entropy. The T and R entropies are therefore not intrinsically irreversible. These results are obtained as special cases of a more general result: if D(x) = 0 then dS/dt = 0 for any entropy functional S[rho(x)] for which deltaS/deltarho(x) = f(rho(x)/gamma(x)), where gamma(x) is the determinant of the metric tensor in state space and the function f is arbitrary. RP RAMSHAW, JD (reprint author), EG&G IDAHO INC,IDAHO NATL ENGN LAB,POB 1625,IDAHO FALLS,ID 83415, USA. NR 6 TC 49 Z9 50 U1 0 U2 3 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 APR 12 PY 1993 VL 175 IS 3-4 BP 171 EP 172 DI 10.1016/0375-9601(93)90821-G PG 2 WC Physics, Multidisciplinary SC Physics GA KX664 UT WOS:A1993KX66400006 ER PT J AU URIBE, FA VALERIO, J GOTTESFELD, S AF URIBE, FA VALERIO, J GOTTESFELD, S TI APPLICATION OF CONDUCTING POLYMER PRECOATS FOR THE METALLIZATION OF INSULATORS SO SYNTHETIC METALS LA English DT Article; Proceedings Paper CT INTERNATIONAL CONF ON SCIENCE AND TECHNOLOGY OF SYNTHETIC METALS ( ICSM 92 ) CY AUG 12-18, 1992 CL GOTEBORG, SWEDEN AB We describe a process for the metallization of insulating materials based on the application of a conducting polymer precoat, followed by direct metal electrodeposition. The precoat is applied in a single step by immersing the substrate (e.g. printed circuit board material polyimide or nylon) in an aqueous bath containing the monomer (eg. pyrrole), an oxidizing agent (eg. FeCl3) and an appropriate dopant. The conducting polymer coats obtained are typically 0.2 to 0.5 mum thick and have sheet resistivities of several hundred OMEGA/square. This level of sheet resistivity is sufficient for direct metal electrodeposition onto the polymer substrate using standard metal plating baths. The dependences of polypyrrole film conductivities on parameters such as substrate immersion time, the bath temperature, the oxidation potential in the bath, and the nature of the dopant have been investigated. We demonstrate that the electrodeposition of copper onto polypyrrole precoats propagates along the surface from the ohmic contact by a nucleation and dendritic growth. mechanism. RP URIBE, FA (reprint author), LOS ALAMOS NATL LAB,ELECTR RES GRP,LOS ALAMOS,NM 87544, USA. NR 10 TC 2 Z9 2 U1 0 U2 1 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE 1 PA PO BOX 564, 1001 LAUSANNE 1, SWITZERLAND SN 0379-6779 J9 SYNTHETIC MET JI Synth. Met. PD APR 12 PY 1993 VL 57 IS 1 BP 3760 EP 3765 DI 10.1016/0379-6779(93)90510-4 PG 6 WC Materials Science, Multidisciplinary; Physics, Condensed Matter; Polymer Science SC Materials Science; Physics; Polymer Science GA LK890 UT WOS:A1993LK89000049 ER PT J AU MAZUMDAR, S GUO, DD DIXIT, SN AF MAZUMDAR, S GUO, DD DIXIT, SN TI A 4-LEVEL ESSENTIAL STATES MODEL OF 3RD-ORDER OPTICAL NONLINEARITY IN PI-CONJUGATED POLYMERS SO SYNTHETIC METALS LA English DT Article; Proceedings Paper CT INTERNATIONAL CONF ON SCIENCE AND TECHNOLOGY OF SYNTHETIC METALS ( ICSM 92 ) CY AUG 12-18, 1992 CL GOTEBORG, SWEDEN ID THIN-FILMS; POLYDIACETYLENE; SUSCEPTIBILITY; GENERATION AB Theoretical description of optical nonlinearity in pi-conjugated polymers must necessarily include both the on-site and the intersite electron correlations. We show that only three dominant nonlinear optical channels, involving four ''essential states'', determine the bulk of the optical nonlinearity. In ideal isolated strands, third harmonic generation experiments should find two three-photon resonances, and not merely one, as has been generally assumed. Two-photon resonances other than the one due to the essential two-photon excited state will have vanishingly weak intensities due to cancellations between nonlinear optical channels with opposite signs. C1 LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550. RP MAZUMDAR, S (reprint author), UNIV ARIZONA,DEPT PHYS,TUCSON,AZ 85721, USA. NR 14 TC 14 Z9 14 U1 0 U2 5 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE 1 PA PO BOX 564, 1001 LAUSANNE 1, SWITZERLAND SN 0379-6779 J9 SYNTHETIC MET JI Synth. Met. PD APR 12 PY 1993 VL 57 IS 1 BP 3881 EP 3888 DI 10.1016/0379-6779(93)90529-6 PG 8 WC Materials Science, Multidisciplinary; Physics, Condensed Matter; Polymer Science SC Materials Science; Physics; Polymer Science GA LK890 UT WOS:A1993LK89000068 ER PT J AU OLIVIER, SS MAX, CE GAVEL, DT BRASE, JM AF OLIVIER, SS MAX, CE GAVEL, DT BRASE, JM TI TIP-TILT COMPENSATION - RESOLUTION LIMITS FOR GROUND-BASED TELESCOPES USING LASER GUIDE STAR ADAPTIVE OPTICS SO ASTROPHYSICAL JOURNAL LA English DT Article DE ATMOSPHERIC EFFECTS; IMAGE PROCESSING; INSTRUMENTATION, MISCELLANEOUS; TELESCOPES; TURBULENCE ID FRANCE-HAWAII TELESCOPE; ATMOSPHERIC-TURBULENCE; SYNTHETIC BEACON; MAUNA-KEA; ISOPLANATISM; PERFORMANCE; PROPAGATION; CAMERA; PROBE AB The angular resolution of long-exposure images from ground-based telescopes equipped with laser guide star adaptive optics systems is fundamentally limited by the accuracy with which the tip-tilt aberrations introduced by the atmosphere can be corrected. Assuming that a natural star is used as the tilt reference, the residual error due to tilt anisoplanatism can significantly degrade the long-exposure resolution even if the tilt reference star is separated from the object being imaged by a small angle. Given the observed distribution of stars in the sky, the need to find a tilt reference star quite close to the object restricts the fraction of the sky over which long-exposure images with diffraction limited resolution can be obtained. In this paper, we present a comprehensive performance analysis of tip-tilt compensation systems that use a natural star as a tilt reference, taking into account properties of the atmosphere and of the Galactic stellar populations, and optimizing over the system operating parameters to determine the fundamental limits to the long-exposure resolution. Our results show that for a 10 m telescope on Mauna Kea, if the image of the tilt reference star is uncorrected, about half the sky can be imaged in the V band with long-exposure resolution less than 60 mas, while if the image of the tilt reference star is fully corrected, about half the sky can be imaged in the V band with long-exposure resolution less than 16 mas. Furthermore. V-band images with long-exposure resolution less than 16 mas may be obtained with a 10 m telescope on Mauna Kea for unresolved objects brighter than magnitude 22 that are fully corrected by a laser guide star adaptive optics system. This level of resolution represents approximately 70% of the diffraction limit of a 10 m telescope in the V band and is more than a factor of 45 better than the median seeing in the V band on Mauna Kea. RP OLIVIER, SS (reprint author), LAWRENCE LIVERMORE NATL LAB,INST GEOPHYS & PLANETARY PHYS,LIVERMORE,CA 94550, USA. OI Max, Claire/0000-0003-0682-5436 NR 43 TC 34 Z9 34 U1 2 U2 5 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 S WOODLAWN AVE, CHICAGO, IL 60637 SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD APR 10 PY 1993 VL 407 IS 1 BP 428 EP 439 DI 10.1086/172525 PN 1 PG 12 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA KV285 UT WOS:A1993KV28500040 ER PT J AU NIMZ, GJ CAMERON, KL NIEMEYER, S AF NIMZ, GJ CAMERON, KL NIEMEYER, S TI THE LA OLIVINA PYROXENITE SUITE AND THE ISOTOPIC COMPOSITIONS OF MANTLE BASALTS PARENTAL TO THE MID-CENOZOIC ARC VOLCANISM OF NORTHERN MEXICO SO JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH LA English DT Article ID RIO-GRANDE RIFT; SOUTHWESTERN UNITED-STATES; SAN-LUIS-POTOSI; TRACE-ELEMENT; MAGMATIC PROCESSES; CRUSTAL CONTAMINATION; CHILEAN ANDES; EVOLUTION; LITHOSPHERE; COMPLEX AB Two chemically and isotopically distinct groups of pyroxenite xenoliths occur in approximately 2 Ma basanites at the La Olivina xenolith locality within the Camargo basalt field, Chihuahua, Mexico. Both groups occur in composite mantle-peridotite/pyroxenite xenoliths, indicating that they formed in the upper mantle. One group, which has igneouslike textures and chemical and isotopic compositions similar to the host basanite, is assumed to have formed from the Camargo magmas and is thus late Cenozoic in age. The second group has equigranular, recrystallized textures and is unlike the Camargo basanites in isotopic and trace element characteristics. This group appears to have formed in a manner analogous to the igneous-textured group but from magmas related to mid-Cenozoic arc-related basalts that occur in the La Olivina vicinity. The equigranular pyroxenites have Sr-Nd-Pb isotopic compositions similar to these mid-Cenozoic basalts, and magmas calculated to be in equilibrium with the pyroxenites have trace element concentrations similar to these basalts. The recrystallized textures of the equigranular pyroxenites reflect their longer mantle residence time. The equigranular pyroxenites provide a unique opportunity to assess the relative contributions of crust and mantle components to the mid-Cenozoic continental arc-related basalts of northern Mexico. They provide evidence that the isotopic compositions of the mid-Cenozoic basalts (e.g., Sr-87/Sr-86 = approximately 0.7043; epsilon(Nd) = approximately +1; Pb-206/Pb-204 = approximately 18.7) are subcrustal in origin. It appears, therefore, that MASH processes are not responsible for the Sr-Nd isotopic uniformity that is observed in the basalts, nor for their ''bulk earth'' Sr-Nd isotopic values. The pyroxenites and basalts have elevated Pb-207/Pb-204 with respect to Pb-206/Pb-204 compared to oceanic basalts. The subcrustal origin of this signature suggests that it is the result of incorporation of a sedimentary component from the subducted slab. The Sr-Nd-Pb isotopic compositions of the equigranular pyroxenites are similar to those present in ''enriched'' lithospheric mantle in southwestern North America. This enrichment has been observed both directly in metasomatized peridotite xenoliths and indirectly in late Cenozoic basalts of the Rio Grande Rift and Southern Transition Zone of the Colorado Plateau. For the latter, the enrichment has been thought to be Proterozoic in age, but the evidence from the equigranular pyroxenites suggests that the event responsible for the observed isotopic compositions may have instead occurred during the mid-Cenozoic. C1 UNIV CALIF SANTA CRUZ,EARTH SCI BOARD,SANTA CRUZ,CA 94550. RP NIMZ, GJ (reprint author), LAWRENCE LIVERMORE NATL LAB,DIV NUCL CHEM,POB 808,L-232,LIVERMORE,CA 94550, USA. NR 70 TC 19 Z9 20 U1 0 U2 2 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0148-0227 J9 J GEOPHYS RES-SOL EA JI J. Geophys. Res.-Solid Earth PD APR 10 PY 1993 VL 98 IS B4 BP 6489 EP 6509 DI 10.1029/92JB02334 PG 21 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA KX929 UT WOS:A1993KX92900021 ER PT J AU LELOUP, PH HARRISON, TM RYERSON, FJ CHEN, WJ LI, Q TAPPONNIER, P LACASSIN, R AF LELOUP, PH HARRISON, TM RYERSON, FJ CHEN, WJ LI, Q TAPPONNIER, P LACASSIN, R TI STRUCTURAL, PETROLOGICAL AND THERMAL EVOLUTION OF A TERTIARY DUCTILE STRIKE-SLIP SHEAR ZONE, DIANCANG SHAN, YUNNAN SO JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH LA English DT Article ID RED-RIVER; QUATERNARY EXTENSION; TECTONIC EVOLUTION; DIFFUSION DOMAINS; PELITIC SCHISTS; SOUTHERN TIBET; CHINA; ASIA; GARNET; GEOTHERMOMETRY AB The Diancang Shan, a horst massif within the Red River fault zone in Yunnan, People's Republic of China, preserves a structural, petrological, and thermal record of two distinct phases of tectonic activity: a left-lateral ductile shear that terminated between 20 and 17 Ma and a ductile-to-brittle phase of normal faulting which began at 4.7 Ma and remains active. Mylonitic rocks in the core of the range display an early, steep, high-temperature (HT), schistosity and a horizontal stretching lineation that are both parallel to the trend of the belt. Kinematic indicators indicate that shear was left-lateral. The complex shape of the HT schistosity at the southern termination of the massif likely results from a large-scale, oblique, left-lateral C' shear plane that dismembered the shear zone and separated the Ailao Shan and the Diancang Shan as left-lateral deformation terminated. Thermochronological and thermobarometric results suggest that the gneisses were partially unroofed during this event. Along the eastern edge of the Diancang Shan, the HT fabrics were overprinted by low-temperature structures during activation of east clipping normal faults. Cooling associated with this normal/right-lateral faulting along the Diancang Shan (and perhaps activation of the right-lateral/normal movement on the Range Front fault farther south along the Ailao Shan) began at 4.7+/-0.1 Ma. These results tend to support the view that extrusion of Indochina occurred along the left-lateral Red River shear zone between 35 and 19-17 Ma. Initiation of right-lateral/normal slip during the late Miocene may relate to eastward extensional collapse of the thickened Tibetan crust or more probably, to initiation of the second phase of extrusion. C1 INST PHYS GLOBE,F-75252 PARIS 05,FRANCE. LAWRENCE LIVERMORE NATL LAB,INST GEOPHYS & SPACE PHYS,LIVERMORE,CA 94550. UNIV CALIF LOS ANGELES,INST GEOPHYS & PLANETARY PHYS,LOS ANGELES,CA 90024. RP LELOUP, PH (reprint author), UNIV CALIF LOS ANGELES,DEPT EARTH & SPACE SCI,LOS ANGELES,CA 90024, USA. RI Lacassin, Robin/A-6781-2011; Tapponnier, .Paul/B-7033-2011; Leloup, Philippe/A-6053-2012; Harrison, Timothy/E-7443-2012 OI Lacassin, Robin/0000-0003-1424-325X; Tapponnier, .Paul/0000-0002-7135-1962; Leloup, Philippe/0000-0001-6090-8772; NR 72 TC 187 Z9 225 U1 3 U2 18 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0148-0227 J9 J GEOPHYS RES-SOL EA JI J. Geophys. Res.-Solid Earth PD APR 10 PY 1993 VL 98 IS B4 BP 6715 EP 6743 DI 10.1029/92JB02791 PG 29 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA KX929 UT WOS:A1993KX92900037 ER PT J AU OLSON, P SCHUBERT, G ANDERSON, C AF OLSON, P SCHUBERT, G ANDERSON, C TI STRUCTURE OF AXISYMMETRICAL MANTLE PLUMES SO JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH LA English DT Article ID BOUNDARY-LAYER; SOLITARY WAVES; FLOOD BASALTS; MELTING CURVE; CONVECTION; MODELS; FLUID; TEMPERATURE; HOTSPOTS; CONDUITS AB Results of high-resolution numerical calculations of axisymmetric thermal plumes in an infinite Prandtl number fluid with thermally activated viscosity are used to infer the structure of axisymmetric subsolidus thermal plumes in the Earth's lower mantle. We calculate the velocity and temperature distribution for axisymmetric convection above a heated disk in an incompressible fluid cylinder, 2400 km in height and 1200 km in diameter, initially at a uniform temperature T(infinity). The lower boundary, representing the plume source region near the core-mantle boundary, is stress-free and maintained at temperature T(c) > T(infinity). The upper boundary is permeable, allowing the plume to escape the cylinder. We determine the sensitivity of plume structure to viscosity variations eta(infinity)/eta(c) ranging from 10(2) to more than 10(4) and temperature differences AT-T(c)-T(infinity) in the range 400-850 K. Starting plumes consist of a large leading diapir and a trailing conduit connected to the thermal boundary layer above the heated surface. The leading diapir expands during ascent, to about 400 km diameter at 2200 km height. In steady state, the plume consists of a narrow, high-velocity conduit imbedded within a broader thermal halo. The width of both these structures is proportional to height above the heated boundary and inversely proportional to DELTAT and the viscosity ratio. Heat transport in the plume is nearly independent of viscosity variations. A simplified boundary layer model yields a heat transfer law Nu almost-equal-to Ralpha1/3, where Nu is the plume Nusselt number and Ralpha is the Rayleigh number based on DELTAT, eta(infinity), and the radius of the heated circular region feeding the plume. Calculated steady state plume heat transports fit this law to within a few percent. We present several calculations of plumes with heat transport in the range 100-400 GW, similar to the advective heat transport by the Hawaiian hotspot. At the top of the lower mantle, plumes with large viscosity variations have high-velocity conduits 50-60 km in diameter and 125-km-diameter thermal,halos, a centerline temperature anomaly of about 500 K and a centerline velocity of about 75 cm yr-1. Plumes with weak viscosity variations are approximately twice as broad and have centerline temperature anomalies less than 160 K at the same height and much smaller velocity. Large viscosity variations and a minimum heat transport are both required for hotspot formation by plumes originating at the base of the mantle. C1 UNIV CALIF LOS ANGELES,DEPT EARTH & SPACE SCI,LOS ANGELES,CA 90024. UNIV CALIF LOS ANGELES,INST GEOPHYS & PLANETARY PHYS,LOS ANGELES,CA 90024. LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545. RP OLSON, P (reprint author), JOHNS HOPKINS UNIV,DEPT EARTH & PLANETARY SCI,BALTIMORE,MD 21218, USA. NR 50 TC 60 Z9 60 U1 0 U2 3 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0148-0227 J9 J GEOPHYS RES-SOL EA JI J. Geophys. Res.-Solid Earth PD APR 10 PY 1993 VL 98 IS B4 BP 6829 EP 6844 DI 10.1029/92JB01013 PG 16 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA KX929 UT WOS:A1993KX92900041 ER PT J AU ZHANG, H WANG, YY DRAVID, VP DABROWSKI, B ZHANG, K HINKS, DG JORGENSEN, JD AF ZHANG, H WANG, YY DRAVID, VP DABROWSKI, B ZHANG, K HINKS, DG JORGENSEN, JD TI ANISOTROPY OF CHARGE-CARRIERS AND DIELECTRIC FUNCTION OF YBA2CU4O8 (Y124) SO PHYSICA C LA English DT Article ID SUPERCONDUCTORS; PRESSURE; SYSTEM AB Orientation dependent (momentum transfer resolved) electron energy loss spectrometry (EELS) has been utilized to probe the localization of free carrier plasmons in single crystals of YBa2Cu4O8 (Y124). Two low energy excitations are observed in EELS spectra, one at about 1.4 eV which is the free carrier plasmon,and another excitation at about 3.2 eV. The oscillator strength of the free carrier plasmon is observed to vary considerably with momentum transfer. Maximum oscillator strength of the free carrier plasmon is observed when the momentum transfer (q) is confined to the ab planes, while the minimum strength is observed for q parallel to the c-axis. Dielectric function calculated using the Kramers-Kronig analysis indicates that the major differences in the dielectric function of Y124 within the ab plane versus along the c-axis are confined only within the first few eVs. The O K core loss spectra exhibit subtle but important deviations from that of YBa2Cu3O7-delta (Y123). Possible EELS spectral signatures of the double chains in Y124 are discussed. C1 NO ILLINOIS UNIV,SCI & TECHNOL CTR SUPERCOND,DE KALB,IL 60115. NO ILLINOIS UNIV,DEPT PHYS,DE KALB,IL 60115. UNIV CHICAGO,SCI & TECHNOL CTR SUPERCOND,CHICAGO,IL 60637. UNIV CHICAGO,JAMES FRANCK INST,CHICAGO,IL 60637. ARGONNE NATL LAB,SCI & TECHNOL CTR SUPERCOND,ARGONNE,IL 60439. ARGONNE NATL LAB,DIV MAT SCI,ARGONNE,IL 60439. NORTHWESTERN UNIV,SCI & TECHNOL CTR SUPERCOND,EVANSTON,IL 60208. RP ZHANG, H (reprint author), NORTHWESTERN UNIV,DEPT MAT SCI & ENGN,EVANSTON,IL 60208, USA. RI Dravid, Vinayak/B-6688-2009 NR 15 TC 5 Z9 5 U1 0 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4534 J9 PHYSICA C JI Physica C PD APR 10 PY 1993 VL 208 IS 3-4 BP 231 EP 237 DI 10.1016/0921-4534(93)90193-T PG 7 WC Physics, Applied SC Physics GA KX666 UT WOS:A1993KX66600003 ER PT J AU SCHULTZ, AJ GEISER, U WANG, HH WILLIAMS, JM FINGER, LW HAZEN, RM AF SCHULTZ, AJ GEISER, U WANG, HH WILLIAMS, JM FINGER, LW HAZEN, RM TI HIGH-PRESSURE STRUCTURAL PHASE-TRANSITIONS IN THE ORGANIC SUPERCONDUCTOR K-(ET)2CU[N(CN)2]CL SO PHYSICA C LA English DT Article ID NEUTRON-DIFFRACTION; CRYSTAL; KBAR; TEMPERATURE; SALTS AB A reversible symmetry-lowering structural phase transition is observed by X-ray diffraction techniques from single crystals of kappa-(ET)2CU[N(CN)2]Cl (ET, or BEDT-TTF, is bis(ethylenedithio)tetrathiafulvalene, C10H8S8) under applied pressure. At room temperature, by use of a diamond anvil cell, a transition above 8 kbar characterized by peak broadening begins to occur. The transition is also observed by cooling crystals coated with Apiezon N vacuum grease, which is a technique that is also used to produce the high pressure superconducting state (T(c)=12.8 K, P=0.3 kbar). Given the anisotropic nature of the structure, the ambient pressure linear compressibilities are surprisingly isotropic, with values of beta(a)=2.39(8) x 10(-3), beta(b)=2.47(7) x 10(-3), beta(c)=2.29(9) x 10(-3)kbar-1. At 3 kbar and room temperature, from a complete structure analysis it is shown that the ET molecule conformation is the same as that at ambient pressure although S ... S contacts are reduced by as much as 0.05 angstrom. A second transition, characterized by reversible disappearance of Bragg intensities consistent with pressure-induced amorphization, was observed between 11.4 and 11.8 kbar. C1 ARGONNE NATL LAB,DIV MAT SCI,ARGONNE,IL 60439. CARNEGIE INST WASHINGTON,GEOPHYS LAB,WASHINGTON,DC 20015. CARNEGIE INST WASHINGTON,CTR HIGH PRESSURE RES,WASHINGTON,DC 20015. RP SCHULTZ, AJ (reprint author), ARGONNE NATL LAB,DIV CHEM,ARGONNE,IL 60439, USA. NR 20 TC 17 Z9 17 U1 0 U2 4 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4534 J9 PHYSICA C JI Physica C PD APR 10 PY 1993 VL 208 IS 3-4 BP 277 EP 285 DI 10.1016/0921-4534(93)90199-Z PG 9 WC Physics, Applied SC Physics GA KX666 UT WOS:A1993KX66600009 ER PT J AU BOWERS, CR LONG, HW PIETRASS, T GAEDE, HC PINES, A AF BOWERS, CR LONG, HW PIETRASS, T GAEDE, HC PINES, A TI CROSS POLARIZATION FROM LASER-POLARIZED SOLID XENON TO (CO2)-C-13 BY LOW-FIELD THERMAL MIXING SO CHEMICAL PHYSICS LETTERS LA English DT Article ID NMR AB The first observation of nuclear spin polarization enhancement in a molecular species by coupling to laser-polarized xenon is reported. The spins of (CO2)-C-13 were cooled by inclusion into the xenon solid followed by thermal mixing in magnetic fields comparable to the heteronuclear dipolar interactions. High-field NMR detection yielded enhancement factors of up to 200. Moreover, a change in the sense of the helicity of the optical pumping light results in a sign reversal of the spin temperature and hence an inversion of the C-13 NMR signal. C1 UNIV CALIF BERKELEY,DIV CHEM,BERKELEY,CA 94720. RP BOWERS, CR (reprint author), LAWRENCE BERKELEY LAB,DIV MAT SCI,1 CYCLOTRON RD,BERKELEY,CA 94720, USA. RI Gaede, Holly/B-7392-2015 OI Gaede, Holly/0000-0003-4444-4394 NR 11 TC 66 Z9 68 U1 3 U2 14 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 APR 9 PY 1993 VL 205 IS 2-3 BP 168 EP 170 DI 10.1016/0009-2614(93)89223-5 PG 3 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA KV519 UT WOS:A1993KV51900008 ER PT J AU FUSELIER, SA HILL, P BAUMJOHANN, W GOSLING, JT AF FUSELIER, SA HILL, P BAUMJOHANN, W GOSLING, JT TI LOCAL TIME OCCURRENCE FREQUENCY OF ENERGETIC IONS IN THE EARTHS MAGNETOSHEATH SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID DAYSIDE MAGNETOSHEATH; BOW SHOCK AB The occurrence frequency of energetic ions in the energy range from 8 to 40 keV/e as a function of local time in the magnetosheath is presented. Energetic ions are observed in the magnetosheath with a minimum probability of 25% for all local times. The occurrence frequency for the energetic ions is higher on the dawnside than on the duskside but shows a relative maximum post-noon in the local time range from 12 to 15 hours. The post-noon relative maximum is attributed to a magnetospheric source for the energetic ions while the dawn-dusk asymmetry is attributed to a quasi-parallel bow shock source. C1 MAX PLANCK INST EXTRATERR PHYSIK,W-8046 GARCHING,GERMANY. LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545. RP FUSELIER, SA (reprint author), LOCKHEED PALO ALTO RES LABS,DEPT 91-20,BLDG 255,3251 HANOVER ST,PALO ALTO,CA 94304, USA. RI Baumjohann, Wolfgang/A-1012-2010 OI Baumjohann, Wolfgang/0000-0001-6271-0110 NR 13 TC 6 Z9 6 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 APR 9 PY 1993 VL 20 IS 7 BP 551 EP 554 DI 10.1029/93GL00807 PG 4 WC Geosciences, Multidisciplinary SC Geology GA KY310 UT WOS:A1993KY31000003 ER PT J AU BROSHA, EL DAVIES, PK GARZON, FH RAISTRICK, ID AF BROSHA, EL DAVIES, PK GARZON, FH RAISTRICK, ID TI METASTABILITY OF SUPERCONDUCTING COMPOUNDS IN THE Y-BA-CU-O SYSTEM SO SCIENCE LA English DT Article ID OXIDE SUPERCONDUCTORS; NEUTRON-DIFFRACTION; OXYGEN AB Precision isothermal solution calorimetry was used to determine the standard-state enthalpy of formation of a number of phases in the Y-Ba-Cu-O system. An analysis of the data indicates that YBaCu4O8 is thermodynamically metastable under ambient conditions. Taken together with the results from previous investigations, these data show that all of the superconducting compounds in the Y-Ba-Cu-O system are thermodynamically metastable at low temperatures. C1 UNIV PENN,DEPT MAT SCI & ENGN,PHILADELPHIA,PA 19104. LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545. NR 28 TC 17 Z9 17 U1 1 U2 2 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 SN 0036-8075 J9 SCIENCE JI Science PD APR 9 PY 1993 VL 260 IS 5105 BP 196 EP 198 DI 10.1126/science.260.5105.196 PG 3 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA KW452 UT WOS:A1993KW45200032 PM 17807180 ER PT J AU HOWARD, JE AF HOWARD, JE TI WARFARIN IN THE PREVENTION OF STROKE ASSOCIATED WITH NONRHEUMATIC ATRIAL-FIBRILLATION SO NEW ENGLAND JOURNAL OF MEDICINE LA English DT Letter RP HOWARD, JE (reprint author), BROOKHAVEN NATL LAB,UPTON,NY 11973, USA. NR 1 TC 0 Z9 0 U1 0 U2 0 PU MASS MEDICAL SOC PI BOSTON PA 10 SHATTUCK, BOSTON, MA 02115 SN 0028-4793 J9 NEW ENGL J MED JI N. Engl. J. Med. PD APR 8 PY 1993 VL 328 IS 14 BP 1041 EP 1041 PG 1 WC Medicine, General & Internal SC General & Internal Medicine GA KW282 UT WOS:A1993KW28200022 PM 8450864 ER PT J AU DUNCAN, A EICHTEN, E THACKER, H AF DUNCAN, A EICHTEN, E THACKER, H TI LATTICE QCD, THE QUARK-MODEL, AND HEAVY-LIGHT WAVE-FUNCTIONS SO PHYSICS LETTERS B LA English DT Article AB A multistate smearing method previously introduced allows a detailed study of the properties of heavy-light mesons in lattice QCD. The Coulomb gauge wave functions for the ground state, the first radially excited S-wave state, and the lowest P-wave states of a heavy-light meson are calculated in quenched approximation. The results are found to be in remarkably good agreement with the predictions of a simple relativistic quark model. C1 FERMILAB NATL ACCELERATOR LAB,BATAVIA,IL 60510. UNIV VIRGINIA,DEPT PHYS,CHARLOTTESVILLE,VA 22901. RP DUNCAN, A (reprint author), UNIV PITTSBURGH,DEPT PHYS & ASTRON,PITTSBURGH,PA 15260, USA. NR 18 TC 27 Z9 28 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 APR 8 PY 1993 VL 303 IS 1-2 BP 109 EP 112 DI 10.1016/0370-2693(93)90052-J PG 4 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA KV527 UT WOS:A1993KV52700020 ER PT J AU LIPKIN, HJ AF LIPKIN, HJ TI IMPLICATIONS OF TAU-DECAYS INTO STRANGE SCALAR AND AXIAL-VECTOR MESONS SO PHYSICS LETTERS B LA English DT Article AB Recent reports of the observation of the decay tau-->nu(tau)+K+pi+pi raise interesting questions. The u-s quark mass difference can induce an effective second class current in the strange sector and enhance decays to helicity suppressed scalar states. This suggests searches for scalar strange mesons in the tau-->nu(tau)+K+eta' and tau-->nu(tau)+K+pi decay modes. Tau decays to axial vector final states may clarify strange meson spectroscopy by analogy with the clarification of the a1 problem in the nonstrange sector. Open questions include mixing effects in the strange axial vector mesons and the implications of models based on CD for hadronization and final state interactions following the creation of a qqBAR pair by a weak vertex. C1 TEL AVIV UNIV,RAYMOND & BEVERLY SACKLER FAC EXACT SCI,SCH PHYS & ASTRON,IL-69978 TEL AVIV,ISRAEL. ARGONNE NATL LAB,DIV HIGH ENERGY PHYS,ARGONNE,IL 60439. ARGONNE NATL LAB,DIV PHYS,ARGONNE,IL 60439. RP LIPKIN, HJ (reprint author), WEIZMANN INST SCI,DEPT NUCL PHYS,IL-76100 REHOVOT,ISRAEL. NR 7 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 APR 8 PY 1993 VL 303 IS 1-2 BP 119 EP 124 DI 10.1016/0370-2693(93)90054-L PG 6 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA KV527 UT WOS:A1993KV52700022 ER PT J AU DERRICK, M KRAKAUER, D MAGILL, S MUSGRAVE, B REPOND, J REPOND, S STANEK, R TALAGA, RL THRON, J ARZARELLO, F AYAD, R BARBAGLI, G BARI, G BASILE, M BELLAGAMBA, L BOSCHERINI, D BRUNI, A BRUNI, G BRUNI, P ROMEO, GC CASTELLINI, G CHIARINI, M CIFARELLI, L CINDOLO, F CIRALLI, F CONTIN, A DAURIA, S DELPAPA, C FRASCONI, F GIUSTI, P IACOBUCCI, G LAURENTI, G LEVI, G LIN, Q LISOWSKI, B MACCARRONE, G MARGOTTI, A MASSAM, T NANIA, R NEMOZ, C PALMONARI, F SARTORELLI, G TIMELLINI, R GARCIA, YZ ZICHICHI, A BARGENDE, A CRITTENDEN, J DABBOUS, H DESCH, K DIEKMANN, B DOEKER, T GEERTS, M GEITZ, G GUTJAHR, B HARTMANN, H HARTMANN, J HAUN, D HEINLOTH, K HILGER, E JAKOB, HP KRAMARCZYK, S KUCKES, M MASS, A MENGEL, S MOLLEN, J MONALDI, D MUSCH, H PAUL, E SCHATTEVOY, R SCHNEIDER, JL WEDEMEYER, R CASSIDY, A CUSSANS, DG DYCE, N FAWCETT, HF FOSTER, B GILMORE, R HEATH, GP LANCASTER, M LLEWELLYN, TJ MALOS, J MORGADO, CJS TAPPER, RJ WILSON, SS RAU, RR BARILLARI, T SCHIOPPA, M SUSINNO, G BERNSTEIN, A CALDWELL, A GIALAS I PARSONS, JA RITZ, S SCIULLI, F STRAUB, PB WAI, L YANG, S BURKOT, W ESKREYS, A PIOTRZKOWSKI, K ZACHARA, M ZAWIEJSKI, L BORZEMSKI, P JELEN, K KISIELEWSKA, D KOWALSKI, T RULIKOWSKAZAREBSKA, E SUSZYCKI, L ZAJAC, J KEDZIERSKI, T KOTANSKI, A PRZYBYCIEN, M BAUERDICK, LAT BEHRENS, U BIENLEIN, JK COLDEWEY, C DANNEMANN, A DIERKS, K DORTH, W DREWS, G ERHARD, P FLASINSKI, M FLECK I FURTJES, A GLASER, R GOTTLICHER, P HAAS, T HAGGE, L HAIN, W HASELL, D HULTSCHIG, H JAHNEN, G JOOS, P KASEMANN, M KLANNER, R KOCH, W KOTZ, U KOWALSKI, H LABS, J LADAGE, A LOHR, B LOWE, M LUKE, D MAINUSCH, J MANCZAK, O MOMAYEZI, M NG, JST NICKEL, S NOTZ, D PARK, IH POSNECKER, KU ROHDE, M ROS, E SCHNEEKLOTH, U SCHROEDER, J SCHULZ, W SELONKE, F STILIARIS, E TSCHESLOG, E TSURUGAI, T TURKOT, F VOGEL, W WOENIGER, T WOLF, G YOUNGMAN, C GRABOSCH, HJ LEICH, A MEYER, A RETHFELDT, C SCHLENSTEDT, S CASALBUONI, R DECURTIS, S DOMINICI, D FRANCESCATO, A NUTI, M PELFER, P ANZIVINO, G CASACCIA, R DEPASQUALE, S QIAN, S VOTANO, L BAMBERGER, A FREIDHOF, A POSER, T SOLDNERREMBOLD, S THEISEN, G TREFZGER, T BROOK, NH BUSSEY, PJ DOYLE, AT FORBES Jr JAMIESON, VA RAINE, C SAXON, DH BRUCKMANN, H GLOTH, G HOLM, U KAMMERLOCHER, H KREBS, B NEUMANN, T WICK, K HOFMANN, A KROGER, W KRUGER, J LOHRMANN, E MILEWSKI, J NAKAHATA, M PAVEL, N POELZ, G SALOMON, R SEIDMAN, A SCHOTT, W WIIK, BH ZETSCHE, F BACON, TC BUTTERWORTH I MARKOU, C MCQUILLAN, D MILLER, DB MOBAYYEN, MM PRINIAS, A VORVOLAKOS, A BIENZ, T KREUTZMANN, H MALLIK, U MCCLIMENT, E ROCO, M WANG, MZ CLOTH, P FILGES, D CHEN, L IMLAY, R KARTIK, S KIM, HJ MCNEIL, RR METCALF, W BARREIRO, F CASES, G HERVAS, L LABARGA, L DELPESO, J ROLDAN, J TERRON, J DETROCONIZ, JF IKRAIAM, F MAYER, JK SMITH, GR CORRIVEAU, F GILKINSON, DJ HANNA, DS HUNG, LW MITCHELL, JW PATEL, PM SINCLAIR, LE STAIRS, DG ULLMANN, R BASHINDZHAGYAN, GL ERMOLOV, PF GOLUBKOV, YA KUZMIN, VA KUZNETSOV, EN SAVIN, AA VORONIN, AG ZOTOV, NP BENTVELSEN, S DAKE, A ENGELEN, J DEJONG, P DEJONG, S DEKAMPS, M KOOIJMAN, P KRUSE, A VANDERLUGT, H ODELL V STRAVER, J TENNER, A TIECKE, H UIJTERWAAL, H VERMEULEN, J WIGGERS, L DEWOLF, E VANWOUDENBERG, R YOSHIDA, R BYLSMA, B DURKIN, LS LI, C LING, TY MCLEAN, KW MURRAY, WN PARK, SK ROMANOWSKI, TA SEIDLEIN, R BLAIR, GA BUTTERWORTH, JM BYRNE, A CASHMORE, RJ COOPERSARKAR, AM DEVENISH, RCE GINGRICH, DM HALLAMBAKER, PM HARNEW, N KHATRI, T LONG, KR LUFFMAN, P MCARTHUR I MORAWITZ, P NASH, J SMITH, SJP ROOCROFT, NC WILSON, FF ABBIENDI, G BRUGNERA, R CARLIN, R DALCORSO, F DEGIORGI, M DOSSELLI, U GASPARINI, F LIMENTANI, S MORANDIN, M POSOCCO, M STANCO, L STROILI, R VOCI, C FEILD, G LIM, JN OH, BY WHITMORE, J CONTINO, U DAGOSTINI, G GUIDA, M IORI, M MARI, SM MARINI, G MATTIOLI, M NIGRO, A HART, JC MCCUBBIN, NA SHAH, TP SHORT, TL BARBERIS, E CARTIGLIA, N HEUSCH, C HUBBARD, B LESLIE, J OSHAUGHNESSY, K SADROZINSKI, HF SEIDEN, A BADURA, E BILTZINGER, J CHAVES, H ROST, M SEIFERT, RJ WALENTA, AH WEIHS, W ZECH, G DAGAN, S LEVY, A ZERZION, D HASEGAWA, T HAZUMI, M ISHII, T KASAI, S KUZE, M NAGASAWA, Y NAKAO, M OKUNO, H TOKUSHUKU, K WATANABE, T YAMADA, S CHIBA, M HAMATSU, R HIROSE, T KITAMURA, S NAGAYAMA, S NAKAMITSU, Y ARNEODO, M COSTA, M FERRERO, MI LAMBERTI, L MASELLI, S PERONI, C SOLANO, A STAIANO, A DARDO, M BAILEY, DC BANDYOPADHYAY, D BENARD, F BHADRA, S BRKIC, M BUROW, BD CHLEBANA, FS CROMBIE, MB HARTNER, GF LEVMAN, GM MARTIN, JF ORR, RS PRENTICE, JD SAMPSON, CR STAIRS, GG TEUSCHER, RJ YOON, TS BULLOCK, FW CATTERALL, CD GIDDINGS, JC JONES, TW KHAN, AM LANE, JB MAKKAR, PL SHAW, D SHULMAN, J BLANKENSHIP, K GIBAUT, DB KOCHOCKI, J LU, B MO, LW CHARCHULA, K CIBOROWSKI, J GAJEWSKI, J GRZELAK, G KASPRZAK, M KRZYZANOWSKI, M MUCHOROWSKI, K NOWAK, RJ PAWLAK, JM STOJDA, K STOPCZYNSKI, A SZWED, R TYMIENIECKA, T WALCZAK, R WROBLEWSKI, AK ZAKRZEWSKI, JA ZARNECKI, AF ADAMUS, M ABRAMOWICZ, H EISENBERG, Y GLASMAN, C KARSHON, U MONTAG, A REVEL, D SHAPIRA, A ALI I BEHRENS, B CAMERINI, U DASU, S FORDHAM, C FOUDAS, C GOUSSIOU, A LOMPERSKI, M LOVELESS, RJ NYLANDER, P PTACEK, M REEDER, DD SMITH, WH SILVERSTEIN, S FRISKEN, WR FURUTANI, KM IGA, Y AF DERRICK, M KRAKAUER, D MAGILL, S MUSGRAVE, B REPOND, J REPOND, S STANEK, R TALAGA, RL THRON, J ARZARELLO, F AYAD, R BARBAGLI, G BARI, G BASILE, M BELLAGAMBA, L BOSCHERINI, D BRUNI, A BRUNI, G BRUNI, P ROMEO, GC CASTELLINI, G CHIARINI, M CIFARELLI, L CINDOLO, F CIRALLI, F CONTIN, A DAURIA, S DELPAPA, C FRASCONI, F GIUSTI, P IACOBUCCI, G LAURENTI, G LEVI, G LIN, Q LISOWSKI, B MACCARRONE, G MARGOTTI, A MASSAM, T NANIA, R NEMOZ, C PALMONARI, F SARTORELLI, G TIMELLINI, R GARCIA, YZ ZICHICHI, A BARGENDE, A CRITTENDEN, J DABBOUS, H DESCH, K DIEKMANN, B DOEKER, T GEERTS, M GEITZ, G GUTJAHR, B HARTMANN, H HARTMANN, J HAUN, D HEINLOTH, K HILGER, E JAKOB, HP KRAMARCZYK, S KUCKES, M MASS, A MENGEL, S MOLLEN, J MONALDI, D MUSCH, H PAUL, E SCHATTEVOY, R SCHNEIDER, JL WEDEMEYER, R CASSIDY, A CUSSANS, DG DYCE, N FAWCETT, HF FOSTER, B GILMORE, R HEATH, GP LANCASTER, M LLEWELLYN, TJ MALOS, J MORGADO, CJS TAPPER, RJ WILSON, SS RAU, RR BARILLARI, T SCHIOPPA, M SUSINNO, G BERNSTEIN, A CALDWELL, A GIALAS, I PARSONS, JA RITZ, S SCIULLI, F STRAUB, PB WAI, L YANG, S BURKOT, W ESKREYS, A PIOTRZKOWSKI, K ZACHARA, M ZAWIEJSKI, L BORZEMSKI, P JELEN, K KISIELEWSKA, D KOWALSKI, T RULIKOWSKAZAREBSKA, E SUSZYCKI, L ZAJAC, J KEDZIERSKI, T KOTANSKI, A PRZYBYCIEN, M BAUERDICK, LAT BEHRENS, U BIENLEIN, JK COLDEWEY, C DANNEMANN, A DIERKS, K DORTH, W DREWS, G ERHARD, P FLASINSKI, M FLECK, I FURTJES, A GLASER, R GOTTLICHER, P HAAS, T HAGGE, L HAIN, W HASELL, D HULTSCHIG, H JAHNEN, G JOOS, P KASEMANN, M KLANNER, R KOCH, W KOTZ, U KOWALSKI, H LABS, J LADAGE, A LOHR, B LOWE, M LUKE, D MAINUSCH, J MANCZAK, O MOMAYEZI, M NG, JST NICKEL, S NOTZ, D PARK, IH POSNECKER, KU ROHDE, M ROS, E SCHNEEKLOTH, U SCHROEDER, J SCHULZ, W SELONKE, F STILIARIS, E TSCHESLOG, E TSURUGAI, T TURKOT, F VOGEL, W WOENIGER, T WOLF, G YOUNGMAN, C GRABOSCH, HJ LEICH, A MEYER, A RETHFELDT, C SCHLENSTEDT, S CASALBUONI, R DECURTIS, S DOMINICI, D FRANCESCATO, A NUTI, M PELFER, P ANZIVINO, G CASACCIA, R DEPASQUALE, S QIAN, S VOTANO, L BAMBERGER, A FREIDHOF, A POSER, T SOLDNERREMBOLD, S THEISEN, G TREFZGER, T BROOK, NH BUSSEY, PJ DOYLE, AT FORBES, JR JAMIESON, VA RAINE, C SAXON, DH BRUCKMANN, H GLOTH, G HOLM, U KAMMERLOCHER, H KREBS, B NEUMANN, T WICK, K HOFMANN, A KROGER, W KRUGER, J LOHRMANN, E MILEWSKI, J NAKAHATA, M PAVEL, N POELZ, G SALOMON, R SEIDMAN, A SCHOTT, W WIIK, BH ZETSCHE, F BACON, TC BUTTERWORTH, I MARKOU, C MCQUILLAN, D MILLER, DB MOBAYYEN, MM PRINIAS, A VORVOLAKOS, A BIENZ, T KREUTZMANN, H MALLIK, U MCCLIMENT, E ROCO, M WANG, MZ CLOTH, P FILGES, D CHEN, L IMLAY, R KARTIK, S KIM, HJ MCNEIL, RR METCALF, W BARREIRO, F CASES, G HERVAS, L LABARGA, L DELPESO, J ROLDAN, J TERRON, J DETROCONIZ, JF IKRAIAM, F MAYER, JK SMITH, GR CORRIVEAU, F GILKINSON, DJ HANNA, DS HUNG, LW MITCHELL, JW PATEL, PM SINCLAIR, LE STAIRS, DG ULLMANN, R BASHINDZHAGYAN, GL ERMOLOV, PF GOLUBKOV, YA KUZMIN, VA KUZNETSOV, EN SAVIN, AA VORONIN, AG ZOTOV, NP BENTVELSEN, S DAKE, A ENGELEN, J DEJONG, P DEJONG, S DEKAMPS, M KOOIJMAN, P KRUSE, A VANDERLUGT, H ODELL, V STRAVER, J TENNER, A TIECKE, H UIJTERWAAL, H VERMEULEN, J WIGGERS, L DEWOLF, E VANWOUDENBERG, R YOSHIDA, R BYLSMA, B DURKIN, LS LI, C LING, TY MCLEAN, KW MURRAY, WN PARK, SK ROMANOWSKI, TA SEIDLEIN, R BLAIR, GA BUTTERWORTH, JM BYRNE, A CASHMORE, RJ COOPERSARKAR, AM DEVENISH, RCE GINGRICH, DM HALLAMBAKER, PM HARNEW, N KHATRI, T LONG, KR LUFFMAN, P MCARTHUR, I MORAWITZ, P NASH, J SMITH, SJP ROOCROFT, NC WILSON, FF ABBIENDI, G BRUGNERA, R CARLIN, R DALCORSO, F DEGIORGI, M DOSSELLI, U GASPARINI, F LIMENTANI, S MORANDIN, M POSOCCO, M STANCO, L STROILI, R VOCI, C FEILD, G LIM, JN OH, BY WHITMORE, J CONTINO, U DAGOSTINI, G GUIDA, M IORI, M MARI, SM MARINI, G MATTIOLI, M NIGRO, A HART, JC MCCUBBIN, NA SHAH, TP SHORT, TL BARBERIS, E CARTIGLIA, N HEUSCH, C HUBBARD, B LESLIE, J OSHAUGHNESSY, K SADROZINSKI, HF SEIDEN, A BADURA, E BILTZINGER, J CHAVES, H ROST, M SEIFERT, RJ WALENTA, AH WEIHS, W ZECH, G DAGAN, S LEVY, A ZERZION, D HASEGAWA, T HAZUMI, M ISHII, T KASAI, S KUZE, M NAGASAWA, Y NAKAO, M OKUNO, H TOKUSHUKU, K WATANABE, T YAMADA, S CHIBA, M HAMATSU, R HIROSE, T KITAMURA, S NAGAYAMA, S NAKAMITSU, Y ARNEODO, M COSTA, M FERRERO, MI LAMBERTI, L MASELLI, S PERONI, C SOLANO, A STAIANO, A DARDO, M BAILEY, DC BANDYOPADHYAY, D BENARD, F BHADRA, S BRKIC, M BUROW, BD CHLEBANA, FS CROMBIE, MB HARTNER, GF LEVMAN, GM MARTIN, JF ORR, RS PRENTICE, JD SAMPSON, CR STAIRS, GG TEUSCHER, RJ YOON, TS BULLOCK, FW CATTERALL, CD GIDDINGS, JC JONES, TW KHAN, AM LANE, JB MAKKAR, PL SHAW, D SHULMAN, J BLANKENSHIP, K GIBAUT, DB KOCHOCKI, J LU, B MO, LW CHARCHULA, K CIBOROWSKI, J GAJEWSKI, J GRZELAK, G KASPRZAK, M KRZYZANOWSKI, M MUCHOROWSKI, K NOWAK, RJ PAWLAK, JM STOJDA, K STOPCZYNSKI, A SZWED, R TYMIENIECKA, T WALCZAK, R WROBLEWSKI, AK ZAKRZEWSKI, JA ZARNECKI, AF ADAMUS, M ABRAMOWICZ, H EISENBERG, Y GLASMAN, C KARSHON, U MONTAG, A REVEL, D SHAPIRA, A ALI, I BEHRENS, B CAMERINI, U DASU, S FORDHAM, C FOUDAS, C GOUSSIOU, A LOMPERSKI, M LOVELESS, RJ NYLANDER, P PTACEK, M REEDER, DD SMITH, WH SILVERSTEIN, S FRISKEN, WR FURUTANI, KM IGA, Y TI INITIAL STUDY OF DEEP INELASTIC-SCATTERING WITH ZEUS AT HERA SO PHYSICS LETTERS B LA English DT Article ID LUND MONTE-CARLO; JET FRAGMENTATION; E+E-PHYSICS; CONSTRUCTION; CALORIMETER AB Results are presented on neutral current, deep inelastic scattering measured in collisions of 26.7 GeV electrons and 820 GeV protons. 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INFN, I-35131 PADUA, ITALY. UNIV PADUA, DIPARTIMENTO FIS, I-35131 PADUA, ITALY. PENN STATE UNIV, DEPT PHYS, UNIV PK, PA 16802 USA. UNIV ROMA LA SAPIENZA, DIPARTIMENTO FIS, I-00185 ROME, ITALY. RUTHERFORD APPLETON LAB, DIDCOT OX11 0QX, OXON, ENGLAND. UNIV CALIF SANTA CRUZ, SANTA CRUZ, CA 95064 USA. UNIV GESAMTHSCH SIEGEN, FACHBEREICH PHYS, W-5900 SIEGEN 21, GERMANY. TEL AVIV UNIV, SCH PHYS, IL-69978 TEL AVIV, ISRAEL. UNIV TOKYO, INST NUCL STUDY, TANASHI, TOKYO 188, JAPAN. TOKYO METROPOLITAN UNIV, DEPT PHYS, TOKYO 158, JAPAN. UNIV TURIN, DIPARTIMENTO FIS SPERIMENTALE, I-10125 TURIN, ITALY. INFN, I-10125 TURIN, ITALY. UNIV TURIN, FAC SCI MFN, I-10125 TURIN, ITALY. UNIV TORONTO, DEPT PHYS, TORONTO M5S 1A7, ONTARIO, CANADA. UNIV LONDON UNIV COLL, DEPT PHYS & ASTRON, LONDON WC1E 6BT, ENGLAND. VIRGINIA POLYTECH INST & STATE UNIV, DEPT PHYS, BLACKSBURG, VA 24061 USA. UNIV WARSAW, INST EXPTL PHYS, PL-00681 WARSAW, POLAND. INST NUCL STUDIES, WARSAW, POLAND. WEIZMANN INST SCI, DEPT NUCL PHYS, IL-76100 REHOVOT, ISRAEL. UNIV WISCONSIN, DEPT PHYS, MADISON, WI 53706 USA. YORK UNIV, DEPT PHYS, N YORK, ON, CANADA. IROE, FLORENCE, ITALY. RP DERRICK, M (reprint author), ARGONNE NATL LAB, ARGONNE, IL 60439 USA. RI De Pasquale, Salvatore/B-9165-2008; Lancaster, Mark/C-1693-2008; Doyle, Anthony/C-5889-2009; Golubkov, Yury/E-1643-2012; Wiggers, Leo/B-5218-2015; Morandin, Mauro/A-3308-2016; Frasconi, Franco/K-1068-2016; Weihs, Wolfgang/E-8005-2017; OI iori, maurizio/0000-0002-6349-0380; Lancaster, Mark/0000-0002-8872-7292; De Pasquale, Salvatore/0000-0001-9236-0748; Doyle, Anthony/0000-0001-6322-6195; Wiggers, Leo/0000-0003-1060-0520; Morandin, Mauro/0000-0003-4708-4240; Frasconi, Franco/0000-0003-4204-6587; Weihs, Wolfgang/0000-0003-0884-0947; Castellini, Guido/0000-0002-0177-0643; Anzivino, Giuseppina/0000-0002-5967-0952 NR 27 TC 33 Z9 33 U1 0 U2 2 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 APR 8 PY 1993 VL 303 IS 1-2 BP 183 EP 197 DI 10.1016/0370-2693(93)90065-P PG 15 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA KV527 UT WOS:A1993KV52700033 ER PT J AU OPRESKO, DM AF OPRESKO, DM TI A NEW SPECIES OF SIBOPATHES (CNIDARIA, ANTHOZOA, ANTIPATHARIA, ANTIPATHIDAE) FROM THE GULF-OF-MEXICO SO PROCEEDINGS OF THE BIOLOGICAL SOCIETY OF WASHINGTON LA English DT Article AB A new species of antipatharian (Cnidaria: Anthozoa: Antipatharia), Sibopathes macrospina, is described from the Gulf of Mexico. The species differs from the only other species in the genus, S. gephura van Pesch, by having longer spines and anterior pinnules positioned slightly above, rather than below, the adjacent lateral pinnules. The taxonomic relationships of Sibopathes with Cladopathes, Hexapathes, Taxipathes, Bathypathes, Schizopathes, and Parantipathes are discussed. RP OPRESKO, DM (reprint author), OAK RIDGE NATL LAB,DIV HLTH & SAFETY RES,POB 2008,OAK RIDGE,TN 37831, USA. NR 5 TC 2 Z9 2 U1 0 U2 0 PU BIOL SOC WASHINGTON PI WASHINGTON PA NAT MUSEUM NAT HIST SMITHSONIAN INST, WASHINGTON, DC 20560 SN 0006-324X J9 P BIOL SOC WASH JI Proc. Biol. Soc. Wash. PD APR 8 PY 1993 VL 106 IS 1 BP 195 EP 203 PG 9 WC Biology SC Life Sciences & Biomedicine - Other Topics GA KX034 UT WOS:A1993KX03400021 ER PT J AU MIKAELIAN, KO AF MIKAELIAN, KO TI FUNCTIONS SIN(K)X AND COS(K)X SO JOURNAL OF PHYSICS A-MATHEMATICAL AND GENERAL LA English DT Article ID RAYLEIGH-TAYLOR INSTABILITY AB We introduce the piecewise linear functions sin(K) x and cos(K) x representing K straight line segments with vertices on sin x and cos x respectively. We Fourier expand these functions, discuss their properties, and derive a number of identities which follow from the expansion of the functions themselves and their integrals or derivatives. The motivation to study sin(K) x and cos(K) x comes from computer simulations of the Rayleigh-Taylor instability in which the eigenmodes sin x and cos x are represented by sin(k) x and cos(K) x, K + 1 being the number of nodes used in the simulations. We find that the harmonics generated by a finite K representation occur only at multiples of K plus or minus one. RP MIKAELIAN, KO (reprint author), LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550, USA. NR 9 TC 4 Z9 4 U1 0 U2 2 PU IOP PUBLISHING LTD PI BRISTOL PA TECHNO HOUSE, REDCLIFFE WAY, BRISTOL, ENGLAND BS1 6NX SN 0305-4470 J9 J PHYS A-MATH GEN JI J. Phys. A-Math. Gen. PD APR 7 PY 1993 VL 26 IS 7 BP 1673 EP 1689 DI 10.1088/0305-4470/26/7/023 PG 17 WC Physics, Multidisciplinary; Physics, Mathematical SC Physics GA KY842 UT WOS:A1993KY84200023 ER PT J AU ENGELKE, R AF ENGELKE, R TI ABINITIO CALCULATIONS OF 10 CARBON NITROGEN CUBANOIDS SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Article ID VALENCE ISOMERS; TRANSFORMATIONS; SCHEMES; SPECTRA; SERIES; N8 AB The results of a uniform set of ab initio quantum-chemical calculations for 10 carbon/nitrogen cubanoids are presented. There are 22 possible C/N cubanoids with formulas (CH)8-nNn, where 0 less-than-or-equal-to n less-than-or-equal-to 8. We give results for one cubanoid for each value of n; for n = 4 both the T(d) and C4v structures are discussed. The geometries were optimized on the RHF/6-31G*//RHF/6-31G* energy hypersurfaces, and the stationary points so obtained were characterized by vibrational analyses. The effect of electron correlation on the energies of these structures is examined via MP2/6-31G*//RHF/6-31G* theory. All 10 structures are predicted to be stable molecules, and the vibrational analyses indicate that their geometries are well-defined by the RHF/6-31G*// energy hypersurfaces. Heats of formation are predicted via appropriate isodesmic reactions. All the structures are found to have large positive DELTAH(f)'s. Perhaps the most interesting result obtained is that the high-energy content of the nitrogen-rich cubanoids is not primarily due to bond strain, but rather to the high-energy content of the NN single bond. Comparisons of the ab initio DELTAH(f) values with semiempirical AM1, PM3, and MNDO predictions are made. If they can be synthesized and have reasonable kinetic stability, the C/N cubanoids containing four or more nitrogen atoms are likely to bc important energetic materials. A brief discussion is given of the potential of these materials as propellants and explosives. RP ENGELKE, R (reprint author), LOS ALAMOS NATL LAB,MS P952,LOS ALAMOS,NM 87545, USA. NR 25 TC 72 Z9 73 U1 1 U2 2 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 APR 7 PY 1993 VL 115 IS 7 BP 2961 EP 2967 DI 10.1021/ja00060a051 PG 7 WC Chemistry, Multidisciplinary SC Chemistry GA KW980 UT WOS:A1993KW98000051 ER PT J AU GEORGE, SJ LOWERY, MD SOLOMON, EI CRAMER, SP AF GEORGE, SJ LOWERY, MD SOLOMON, EI CRAMER, SP TI COPPER L-EDGE SPECTRAL STUDIES - A DIRECT EXPERIMENTAL PROBE OF THE GROUND-STATE COVALENCY IN THE BLUE COPPER SITE IN PLASTOCYANIN SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Note ID ELECTRONIC-STRUCTURE; FEATURES C1 UNIV CALIF DAVIS,DEPT APPL SCI,DAVIS,CA 95616. LAWRENCE BERKELEY LAB,DIV ENERGY & ENVIRONM,BERKELEY,CA 94720. STANFORD UNIV,DEPT CHEM,STANFORD,CA 94305. NR 14 TC 116 Z9 116 U1 1 U2 19 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 APR 7 PY 1993 VL 115 IS 7 BP 2968 EP 2969 DI 10.1021/ja00060a052 PG 2 WC Chemistry, Multidisciplinary SC Chemistry GA KW980 UT WOS:A1993KW98000052 ER PT J AU PALMANS, R FRANK, AJ HOULDING, VH MISKOWSKI, VM AF PALMANS, R FRANK, AJ HOULDING, VH MISKOWSKI, VM TI PHOTOPHYSICS AND PHOTOSENSITIZATION BEHAVIOR OF MICROCRYSTALLINE [PT(BPY)2]2[PT2(POP)4].NH2O SO JOURNAL OF MOLECULAR CATALYSIS LA English DT Article ID ALPHA-DIIMINE LIGANDS; PLATINUM(II) COMPLEXES; ELECTRONIC SPECTROSCOPY; EXCITED-STATES; DOUBLE SALTS; SPECTRA; 2,2'-BIPYRIDINE; PT2(P2O5H2)44; PALLADIUM(II); ABSORPTION AB The insoluble double salt complex [Pt(bpy)2]2 [Pt2(pop)4].nH2O (''PBPop''; bpy = 2,2'-bipyridine and pop = H2P2O52- is prepared by mixing an aqueous solution of the monomers. In the solid state, the initial orange complex has ca. 4 waters of hydration and a variable diffuse reflectance maximum in the region of 510-530 nm which imparts an orange color. The complex dehydrates readily and irreversibly to a yellow form with ca. 2 waters of hydration whose diffuse reflectance spectrum shows no maximum at wavelengths greater than 500 nm. Both orange and yellow forms exhibit the same emission spectrum, with a maximum at 615 nm and a halfwidth of 3100 cm-1 at room temperature. The emission of yellow PBPop is extremely intense, with a room temperature lifetime of 45 ns and an estimated radiative rate constant of 70 000 s-1. The emission maximum does not shift with decreasing temperature, but the halfwidth narrows to 2500 cm-1 at 40 K. In the case of orange PBPop, the emission intensity is very weak. The emission is attributed to either a chromophore or a trap state common to both orange and yellow forms. Powder suspensions of both forms of PBPop are active as photosensitizers for generating H-2 from aqueous solutions containing ethylenediaminetetraacetate (EDTA2-) as an electron donor and a colloidal Pt catalyst. Visible light excitation of the yellow double salt (lambda(ex) > 400 nm) leads to large turnover numbers ([H-2]/[ PBPop] > 100), indicating that H-2 is evolved catalytically. The photoproduction of H-2 is also observed in the absence of the Pt catalyst; however, the rate is a factor of 15 lower. The yellow form of PBPop is considerably more active than the orange form. In the presence of the latter complex, a relative long induction period accompanies H-2 formation. Both the yield and the rate of H-2 production with PBPop display a marked dependence on the excitation wavelength in the region 400-515 nm. Although PBPop is relatively stable in acidic EDTA2- solution (pH 4.75), it undergoes dark decomposition in alkaline triethanolamine solution (pH 9.5). Also, during UV illumination (lambda(ex) > 345 nm), photodegradation of PBPop particles occurs along with H-2 evolution. The basis of these and other phenomena are discussed. C1 NATL RENEWABLE ENERGY LAB,GOLDEN,CO 80401. BANDGAP TECHNOL CORP,BROOMFIELD,CO 80021. CALTECH,ARTHUR AMOS NOYES LAB,PASADENA,CA 91125. NR 24 TC 5 Z9 5 U1 0 U2 4 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0304-5102 J9 J MOL CATAL PD APR 6 PY 1993 VL 80 IS 3 BP 327 EP 340 DI 10.1016/0304-5102(93)85006-F PG 14 WC Chemistry, Physical SC Chemistry GA KX980 UT WOS:A1993KX98000006 ER PT J AU CHALMERS, SA LEAR, KL KILLEEN, KP AF CHALMERS, SA LEAR, KL KILLEEN, KP TI LOW RESISTANCE WAVELENGTH-REPRODUCIBLE P-TYPE (AL,GA)AS DISTRIBUTED BRAGG REFLECTORS GROWN BY MOLECULAR-BEAM EPITAXY SO APPLIED PHYSICS LETTERS LA English DT Article ID SURFACE-EMITTING LASERS; QUANTUM-WELL LASERS; SERIES RESISTANCE AB We report the reproducible molecular beam epitaxial growth of Be-doped piecewise linearly graded (Al,Ga)As distributed Bragg reflectors that have vertical series resistivities near bulk values. For mirrors with three linear segments per interface, the center wavelength reproducibility is 0.1% and the series resistivity is as low as 1.8 X 10(-5) OMEGA cm2 for hole concentrations of 5 X 10(18) cm-3. Measured reflectivities of 6.0% per interface are comparable to conventional single-linear-grade mirrors. Vertical-cavity surface-emitting lasers incorporating these mirrors exhibit record-low voltage thresholds of less than 1.5 V. RP CHALMERS, SA (reprint author), SANDIA NATL LABS,ALBUQUERQUE,NM 87185, USA. NR 12 TC 40 Z9 43 U1 0 U2 3 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD APR 5 PY 1993 VL 62 IS 14 BP 1585 EP 1587 DI 10.1063/1.109608 PG 3 WC Physics, Applied SC Physics GA KV995 UT WOS:A1993KV99500003 ER PT J AU ALEXANDER, DE REHN, LE BALDO, PM GAO, Y AF ALEXANDER, DE REHN, LE BALDO, PM GAO, Y TI ENHANCEMENT OF DIFFUSION-INDUCED GRAIN-BOUNDARY MIGRATION BY ION IRRADIATION SO APPLIED PHYSICS LETTERS LA English DT Article ID GROWTH; FILMS; CU AB Diffusion-induced grain boundary migration (DIGM) was observed in Au/Cu bilayers irradiated with 1.5 MeV Kr at T greater-than-or-equal-to 400 K. Rutherford backscattering spectrometry (RBS) showed nearly uniform distributions of Cu present throughout polycrystalline Au films after irradiation and after annealing treatments. Irradiation increased the amount of Cu relative to annealed-only areas. Cross-section transmission electron microscopy combined with x-ray energy dispersive spectroscopy (XEDS) identified alloyed zones (14-20 at. % Cu), confirming DIGM in the Au film of an ion bombarded bilayer. A description of DIGM is presented relating RBS measurements of the film-averaged Cu composition with treatment time, average grain size, and film thickness. Application of this model to the experimental results in combination with XEDS work indicates that irradiation enhances DIGM by increasing the grain boundary velocity. RP ALEXANDER, DE (reprint author), ARGONNE NATL LAB,DIV MAT SCI,ARGONNE,IL 60439, USA. NR 16 TC 6 Z9 6 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 APR 5 PY 1993 VL 62 IS 14 BP 1597 EP 1599 DI 10.1063/1.108597 PG 3 WC Physics, Applied SC Physics GA KV995 UT WOS:A1993KV99500007 ER PT J AU WARREN, WL SCHWANK, JR SHANEYFELT, MR FLEETWOOD, DM WINOKUR, PS AF WARREN, WL SCHWANK, JR SHANEYFELT, MR FLEETWOOD, DM WINOKUR, PS TI HYDROGEN INTERACTIONS WITH DELOCALIZED SPIN CENTERS IN BURIED SIO2 THIN-FILMS SO APPLIED PHYSICS LETTERS LA English DT Article ID SILICON-ON-INSULATOR; RADIATION AB Defect centers have been investigated in bonded and etchback silicon-on-insulator materials following irradiation using electron paramagnetic resonance (EPR). Three different EPR centers are created in the top 0.1 mum of the SiO2 dielectric by either x-ray irradiation or vacuum ultraviolet (VUV) illumination. Two of the defects are the classic E' center (.Si = O3) and the amorphous silicon center (.Si=Si3). The third EPR active defect center is characterized by g = 2.0025 with an effective fine width of 1.1 G. Longer irradiation times transform this new center into a hydrogen-related defect as observed by its two hyperfine lines split by 23.1 G. It appears that this defect is positively charged when EPR active. Using conventional capacitance versus voltage techniques, it is also found that irradiation leads to the generation of positive charge in the dielectric. This charge is located near the bottom Si/SiO2 interface, opposite the interface at which the paramagnetic centers are located. RP WARREN, WL (reprint author), SANDIA NATL LABS,ALBUQUERQUE,NM 87185, USA. NR 19 TC 19 Z9 19 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 APR 5 PY 1993 VL 62 IS 14 BP 1661 EP 1663 DI 10.1063/1.108619 PG 3 WC Physics, Applied SC Physics GA KV995 UT WOS:A1993KV99500029 ER PT J AU NORTON, DP CHAKOUMAKOS, BC BUDAI, JD LOWNDES, DH AF NORTON, DP CHAKOUMAKOS, BC BUDAI, JD LOWNDES, DH TI EPITAXIAL-GROWTH OF SINGLE-CRYSTAL CA1-XSRXCUO2 THIN-FILMS BY PULSED-LASER DEPOSITION SO APPLIED PHYSICS LETTERS LA English DT Article ID SUPERCONDUCTIVITY; LAYER AB Single-crystal thin films of Ca1-xSrxCuO2, the ''infinite layer'' parent compound for the high temperature superconductors, have been grown by pulsed-laser deposition over the composition range 0.15 less-than-or-equal-to x less-than-or-equal-to 1.0 utilizing a single-target codeposition growth scheme. Four-circle x-ray diffractometry reveals that these Ca1-xSrxCuO2 thin films are very high-quality single crystals of the tetragonal, infinite layer phase with extremely narrow diffraction peaks, complete in-plane crystalline alignment with the (100) SrTiO3 substrate, and virtually no impurity phases present. A systematic expansion of the c-axis lattice constant is observed as the Sr content is increased. Four-point transport measurements show that these single-crystal Ca1-xSrxCuO2 films are semiconducting, with room temperature resistivities on the order of an ohm-cm. These results demonstrate that this metastable compound can be epitaxially stabilized over a wide range of composition. RP NORTON, DP (reprint author), OAK RIDGE NATL LAB,DIV SOLID STATE,OAK RIDGE,TN 37831, USA. RI Chakoumakos, Bryan/A-5601-2016; Budai, John/R-9276-2016 OI Chakoumakos, Bryan/0000-0002-7870-6543; Budai, John/0000-0002-7444-1306 NR 16 TC 60 Z9 60 U1 0 U2 5 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD APR 5 PY 1993 VL 62 IS 14 BP 1679 EP 1681 DI 10.1063/1.109574 PG 3 WC Physics, Applied SC Physics GA KV995 UT WOS:A1993KV99500035 ER PT J AU ADMAN, ET MATHER, MW FEE, JA AF ADMAN, ET MATHER, MW FEE, JA TI MOLECULAR MODELING STUDIES ON THE PROPOSED NACL-INDUCED DIMERIZATION OF CHROMATIUM-VINOSUM HIGH-POTENTIAL IRON PROTEIN SO BIOCHIMICA ET BIOPHYSICA ACTA LA English DT Article DE HIGH POTENTIAL IRON-SULFUR PROTEIN; MOLECULAR MODELING; IRON-SULFUR CLUSTER; EPR ID REFINEMENT; RESOLUTION AB Previous work (Dunham, W.R., Hagen, W.R., Fee, J. A., Sands, R.H., Dunbar, J.B., Humblet, C. (1991) An investigation of Chromatium vinosum high-potential iron-sulfur protein by EPR and Mossbauer spectroscopy; evidence for a freezing-induced dimerization in NaCl solutions, Biochimica Biophysica Acta 1079, 253-262) suggested that under specific solution conditions and slow freezing times, samples of oxidized Chromatium vinosum (Cv) high-potential, iron-sulfur protein (HiPIP) form dimeric structures that exhibit characteristic spin-spin interaction in the EPR spectrum. In that study, it was also shown that two HiPIP molecules could approach each other along their Fe1-S4 axes to a distance of approximately 13-14 angstrom, as required by an analysis of the spin-spin physics. This is made possible because of a flattened surface on one side of the molecule within which S4 may, depending on side-chain motions, interact with solvent (Carter, C.W., Jr., Kraut, J., Freer, S.T., Alden, R.A., Sieker, L.C., Adman, E.T., Jensen, L.H. (1972) A CompariSon of Fe4S4 clusters in high potential iron protein and in ferredoxin, Proc. Natl. Acad. Sci. USA 69, 3527-3529). Here we describe a computer generated, hypothetical model of this proposed dimeric structure which suggests an energetically favorable interaction between two Cv HiPIP molecules and could account for the experimental observations. Two Cv HiPIP molecules brought together along their Fe1-S4 axes and maintained at a center-to-center distance of 14 angstrom can be rotated with respect to each other so as to create complementary interactions between two glutamine residues, two phenylalanine residues, and two leucine residues, and an energetically unfavorable interaction between two arginine residues. Energy minimization calculations using the program XPLOR indicate that this arrangement may provide an overall energetically favorable interaction between the two HiPIP molecules that is strengthened by site-specific binding of Na and Cl ions. C1 LOS ALAMOS NATL LAB,DIV ISOTOPE & NUCL CHEM,SPECT & BIOCHEM GRP,LOS ALAMOS,NM 87545. UNIV WASHINGTON,SCH MED,DEPT BIOL STRUCT,SEATTLE,WA 98195. FU NIGMS NIH HHS [GM35342, GM31770] NR 17 TC 8 Z9 8 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0006-3002 J9 BIOCHIM BIOPHYS ACTA PD APR 5 PY 1993 VL 1142 IS 1-2 BP 93 EP 98 DI 10.1016/0005-2728(93)90089-X PG 6 WC Biochemistry & Molecular Biology; Biophysics SC Biochemistry & Molecular Biology; Biophysics GA KW775 UT WOS:A1993KW77500013 PM 8457586 ER PT J AU DISCHER, D PARRA, M CONBOY, JG MOHANDAS, N AF DISCHER, D PARRA, M CONBOY, JG MOHANDAS, N TI MECHANOCHEMISTRY OF THE ALTERNATIVELY SPLICED SPECTRIN-ACTIN BINDING DOMAIN IN MEMBRANE SKELETAL PROTEIN-4.1 SO JOURNAL OF BIOLOGICAL CHEMISTRY LA English DT Article ID ERYTHROCYTE-MEMBRANE; HEREDITARY ELLIPTOCYTOSIS; MECHANICAL-PROPERTIES; BETA-SPECTRIN; BAND 4.1; PHOSPHORYLATION; STABILITY; MODULATION; SITE; PURIFICATION AB Protein 4.1's interaction with the erythroid skeletal proteins spectrin and actin and its essential role in regulating membrane strength are both attributable to expression of an alternatively spliced 63-nucleotide exon. The corresponding 21-amino acid (21-aa) cassette is within the previously identified spectrin-actin binding domain (10 kDa molecular mass) of erythroid protein 4.1. This cassette is absent, however, in several isoforms that are generated by tissue- and development-specific RNA splicing. Four isoforms of the 10-kDa domain were constructed for comparative assessment of functions particularly relevant to red cells. In vitro translated isoforms containing the 21-aa cassette, denoted 10k21 and 10k19,21, were able to bind spectrin, stabilize spectrin-actin complexes, and associate with red cell membrane. Isoforms replacing or lacking the 21-aa cassette, 10k19 and 10k0, did not function in these assays. A bacterially expressed fusion protein with glutathione-S-transferase, designated GST-10k21, congealed-spectrin-actin into a network in vitro as found with purified protein 4.1. Additionally, incorporation of GST-10k21 into mechanically weak, 4.1-deficient membranes increased mechanical strength of these membranes to normal. GST-10k19 did not function in these assays. These results show that the 21-aa sequence in protein 4.1 is critical to mechanical integrity of the red cell membrane. These results also allow the role of protein 4.1 in membrane mechanics to be interpreted primarily in terms of its spectrinactin binding function. Alternatively expressed sequences within the 10-kDa domain of nonerythroid protein 4.1 are suggested to have different, yet to be defined functions. C1 LAWRENCE BERKELEY LAB,DIV LIFE SCI,BERKELEY,CA 94720. UNIV CALIF BERKELEY UNIV CALIF SAN FRANCISCO,JOINT GRAD GRP BIOENGN,SAN FRANCISCO,CA 94143. FU NIDDK NIH HHS [DK 32094] NR 57 TC 88 Z9 88 U1 0 U2 1 PU AMER SOC BIOCHEMISTRY MOLECULAR BIOLOGY INC PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814 SN 0021-9258 J9 J BIOL CHEM JI J. Biol. Chem. PD APR 5 PY 1993 VL 268 IS 10 BP 7186 EP 7195 PG 10 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA KV141 UT WOS:A1993KV14100057 PM 8463254 ER PT J AU VONDERFECHT, BE DICKHOFF, WH POLLS, A RAMOS, A AF VONDERFECHT, BE DICKHOFF, WH POLLS, A RAMOS, A TI INFLUENCE OF TENSOR AND SHORT-RANGE CORRELATIONS ON NUCLEON PROPERTIES IN THE NUCLEAR MEDIUM SO NUCLEAR PHYSICS A LA English DT Article ID SINGLE-PARTICLE PROPERTIES; FEW-BODY SYSTEMS; SHELL-MODEL; OCCUPATION PROBABILITIES; MOMENTUM DISTRIBUTIONS; ELECTRON-SCATTERING; SPECTRAL-FUNCTION; E,E'P REACTION; MATTER; STRENGTH AB The properties of nucleons in the nuclear medium at normal density are studied including the effects of short-range and tensor correlations induced by the realistic Reid soft-core interaction. A complete characterization of the energy dependence of the self-energy and the nucleon spectral functions is obtained. These results clarify the limitations of the mean-field picture of nucleon motion in matter and provide an explanation of a number of problems associated with theoretical calculations in nuclear physics which assume the validity of the mean-field picture. C1 WASHINGTON UNIV, DEPT PHYS, CAMPUS BOX 1105, 1 BROOKINGS DR, ST LOUIS, MO 63130 USA. TRIUMF, VANCOUVER V6T 2A3, BC, CANADA. SAVANNAH RIVER ECOL LAB, AIKEN, SC 29802 USA. UNIV BARCELONA, DEPT ESTRUCT & CONSTITUENTS MAT, E-08028 BARCELONA, SPAIN. RI Dickhoff, Willem/F-4278-2014; Polls, Artur/K-7643-2014; Ramos, Angels/L-3043-2014 OI Dickhoff, Willem/0000-0003-1738-3979; Polls, Artur/0000-0002-3272-106X; Ramos, Angels/0000-0002-0882-1570 NR 57 TC 63 Z9 64 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 APR 5 PY 1993 VL 555 IS 1 BP 1 EP 32 DI 10.1016/0375-9474(93)90312-L PG 32 WC Physics, Nuclear SC Physics GA LH174 UT WOS:A1993LH17400002 ER PT J AU FRABETTI, PL CHEUNG, HWK CUMALAT, JP DALLAPICCOLA, C GINKEL, JF GREENE, SV JOHNS, WE NEHRING, MS BUTLER, JN CIHANGIR, S GAINES, I GARREN, L GARBINCIUS, PH GOURLAY, SA HARDING, DJ KASPER, P KREYMER, A LEBRUN, P SHUKLA, S BIANCO, S FABBRI, FL SARWAR, S ZALLO, A CULBERTSON, R GARDNER, RW GREENE, R WISS, J ALIMONTI, G BELLINI, G CACCIANIGA, B CINQUINI, L DICORATO, M GIAMMARCHI, M INZANI, P LEVERARO, F MALVEZZI, S MENASCE, D MERONI, E MORONI, L PEDRINI, D PERASSO, L SALA, A SALA, S TORRETA, D VITTONE, M BUCHHOLZ, D CLAES, D GOBBI, B OREILLY, B BISHOP, JM CASON, NM KENNEDY, CJ KIM, GN LIN, TF PUSELJIC, DL RUCHTI, RC SHEPARD, WD SWIATEK, JA WU, ZY ARENA, V BOCA, G CASTOLDI, C DIAFERIA, R GIANINI, G RATTI, SP RICCARDI, C VITULO, P LOPEZ, A GRIM, GP PAOLONE, VS YAGER, PM WILSON, JR SHELDON, PD DAVENPORT, F FILASETTA, JF BLACKETT, GR PISHARODY, M HANDLER, T CHEON, BG KANG, JS KIM, KY AF FRABETTI, PL CHEUNG, HWK CUMALAT, JP DALLAPICCOLA, C GINKEL, JF GREENE, SV JOHNS, WE NEHRING, MS BUTLER, JN CIHANGIR, S GAINES, I GARREN, L GARBINCIUS, PH GOURLAY, SA HARDING, DJ KASPER, P KREYMER, A LEBRUN, P SHUKLA, S BIANCO, S FABBRI, FL SARWAR, S ZALLO, A CULBERTSON, R GARDNER, RW GREENE, R WISS, J ALIMONTI, G BELLINI, G CACCIANIGA, B CINQUINI, L DICORATO, M GIAMMARCHI, M INZANI, P LEVERARO, F MALVEZZI, S MENASCE, D MERONI, E MORONI, L PEDRINI, D PERASSO, L SALA, A SALA, S TORRETA, D VITTONE, M BUCHHOLZ, D CLAES, D GOBBI, B OREILLY, B BISHOP, JM CASON, NM KENNEDY, CJ KIM, GN LIN, TF PUSELJIC, DL RUCHTI, RC SHEPARD, WD SWIATEK, JA WU, ZY ARENA, V BOCA, G CASTOLDI, C DIAFERIA, R GIANINI, G RATTI, SP RICCARDI, C VITULO, P LOPEZ, A GRIM, GP PAOLONE, VS YAGER, PM WILSON, JR SHELDON, PD DAVENPORT, F FILASETTA, JF BLACKETT, GR PISHARODY, M HANDLER, T CHEON, BG KANG, JS KIM, KY TI MEASUREMENT OF THE LIFETIME OF THE XI(C)(0) SO PHYSICAL REVIEW LETTERS LA English DT Article AB A measurement of the lifetime of the charmed strange baryon XI(c)0 is presented. The data were accumulated by the Fermilab high energy photoproduction experiment E687. The measurement has been made using 42 +/- 10 XI(c)0 --> XI- pi+ decays. The lifetime of the XI(c)0 is measured to be 0.101(-0.017)+0.025 +/- 0.005 ps and its mass is measured to be 2462.1 +/- 3.1 +/- 1.4 MeV/c2. C1 IST NAZL FIS NUCL,I-40126 BOLOGNA,ITALY. UNIV COLORADO,BOULDER,CO 80309. FERMILAB NATL ACCELERATOR LAB,BATAVIA,IL 60510. IST NAZL FIS NUCL,LAB NAZL FRASCATI,I-00044 FRASCATI,ITALY. UNIV ILLINOIS,URBANA,IL 61801. UNIV MILAN,DIPARTIMENTO FIS,I-20133 MILAN,ITALY. IST NAZL FIS NUCL,I-20133 MILAN,ITALY. NORTHWESTERN UNIV,EVANSTON,IL 60208. UNIV NOTRE DAME,NOTRE DAME,IN 46556. UNIV PAVIA,DIPARTIMENTO FIS,I-27100 PAVIA,ITALY. IST NAZL FIS NUCL,I-27100 PAVIA,ITALY. UNIV PUERTO RICO,MAYAGUEZ,PR 00708. UNIV CALIF DAVIS,DAVIS,CA 95616. UNIV SO CALIF,COLUMBIA,SC 29208. VANDERBILT UNIV,NASHVILLE,TN 37235. UNIV N CAROLINA,ASHEVILLE,NC 28804. NO KENTUCKY UNIV,HIGHLAND HTS,KY 41076. UNIV TENNESSEE,KNOXVILLE,TN 37996. KOREA UNIV,SEOUL 136701,SOUTH KOREA. RP FRABETTI, PL (reprint author), UNIV BOLOGNA,DIPARTIMENTO FIS,I-40126 BOLOGNA,ITALY. NR 8 TC 19 Z9 19 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 APR 5 PY 1993 VL 70 IS 14 BP 2058 EP 2061 DI 10.1103/PhysRevLett.70.2058 PG 4 WC Physics, Multidisciplinary SC Physics GA KV974 UT WOS:A1993KV97400002 ER PT J AU CAUBLE, R PHILLION, DW HOOVER, TJ HOLMES, NC KILKENNY, JD LEE, RW AF CAUBLE, R PHILLION, DW HOOVER, TJ HOLMES, NC KILKENNY, JD LEE, RW TI DEMONSTRATION OF 0.75 GBAR PLANAR SHOCKS IN X-RAY DRIVEN COLLIDING FOILS SO PHYSICAL REVIEW LETTERS LA English DT Article ID MU-M WAVELENGTH; WAVE EXPERIMENTS; LASER; INSTABILITY; PRESSURES; FUSION AB We have directly observed 0.75 +/- 0.2 Gbar planar shocks in gold target foils impacted by ablatively driven gold flyer foils. The x-ray drive for the flyer foils was produced in a gold Hohlraum by ten beams of the Nova laser. The dynamic pressure inferred by shock velocity measurements is more than a factor of 7 greater than previous dynamic shocks produced in the laboratory and over a surface area significantly larger than most previous ultrahigh pressure experiments. The technique allows the laboratory investigations of equations of state in the gigabar regime. RP CAUBLE, R (reprint author), LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550, USA. NR 22 TC 137 Z9 144 U1 0 U2 8 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 APR 5 PY 1993 VL 70 IS 14 BP 2102 EP 2105 DI 10.1103/PhysRevLett.70.2102 PG 4 WC Physics, Multidisciplinary SC Physics GA KV974 UT WOS:A1993KV97400013 ER PT J AU CHEN, XM QUINN, JJ AF CHEN, XM QUINN, JJ TI NUMERICAL STUDY OF FRACTIONAL QUANTUM HALL ELECTRON-HOLE SYSTEMS - EVIDENCE OF STABLE ANYONIC IONS SO PHYSICAL REVIEW LETTERS LA English DT Article ID FLUID; CONDENSATE; INTEGER; STATES AB Spatially separated electron-hole layers in strong magnetic fields are studied by exactly diagonalizing the Hamiltonian of a small number of particles. When the separation between layers is of the same order as the intralayer particle separation, the ground-state energy of the system displays a pronounced cusp as a function of the Landau level degeneracy at an odd denominator fraction nu(c), where nu(c) = (nu(e) - nu(h))/(1 - nu(h)), and nu(e) and nu(h) are the electron and hole filling factors (nu(h) << nu(e)). Detailed analysis suggests that the ground state responsible for the cusp consists of stable ions (composed of Laughlin quasiparticles bound to a hole) weakly coupled to an incompressible fluid state of the remaining electrons. C1 OAK RIDGE NATL LAB,OAK RIDGE,TN 37831. RP CHEN, XM (reprint author), UNIV TENNESSEE,DEPT PHYS & ASTRON,KNOXVILLE,TN 37996, USA. NR 15 TC 43 Z9 43 U1 0 U2 0 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 APR 5 PY 1993 VL 70 IS 14 BP 2130 EP 2133 DI 10.1103/PhysRevLett.70.2130 PG 4 WC Physics, Multidisciplinary SC Physics GA KV974 UT WOS:A1993KV97400020 ER PT J AU HUANG, XZ MAKI, KZ AF HUANG, XZ MAKI, KZ TI IMPERFECT NESTING AND SCATTERING EFFECT IN SPIN-DENSITY WAVES SO SYNTHETIC METALS LA English DT Article; Proceedings Paper CT INTERNATIONAL CONF ON SCIENCE AND TECHNOLOGY OF SYNTHETIC METALS ( ICSM 92 ) CY AUG 12-18, 1992 CL GOTEBORG, SWEDEN AB We study the impurity scattering in spin and charge density wave (SDW/CDW) with imperfect nesting. The impurity scattering suppresses both the SDW (or CDW) order parameter and the transition temperature like the pair-breaking effect in superconductor. Here we analyze the order parameter and the density of states of SDW (or CDW). C1 UNIV SO CALIF,DEPT PHYS,LOS ANGELES,CA 90089. RP HUANG, XZ (reprint author), LOS ALAMOS NATL LAB,DIV THEORET,LOS ALAMOS,NM 87545, USA. NR 9 TC 0 Z9 0 U1 0 U2 0 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE 1 PA PO BOX 564, 1001 LAUSANNE 1, SWITZERLAND SN 0379-6779 J9 SYNTHETIC MET JI Synth. Met. PD APR 5 PY 1993 VL 56 IS 2-3 BP 2767 EP 2773 DI 10.1016/0379-6779(93)90032-R PG 7 WC Materials Science, Multidisciplinary; Physics, Condensed Matter; Polymer Science SC Materials Science; Physics; Polymer Science GA LJ799 UT WOS:A1993LJ79900032 ER PT J AU WOSNITZA, J CRABTREE, GW WILLIAMS, JM WANG, HH CARLSON, KD GEISER, U AF WOSNITZA, J CRABTREE, GW WILLIAMS, JM WANG, HH CARLSON, KD GEISER, U TI DEHAAS - VANALPHEN STUDIES AND FERMI-SURFACE PROPERTIES OF ORGANIC SUPERCONDUCTORS (ET)2X SO SYNTHETIC METALS LA English DT Article; Proceedings Paper CT INTERNATIONAL CONF ON SCIENCE AND TECHNOLOGY OF SYNTHETIC METALS ( ICSM 92 ) CY AUG 12-18, 1992 CL GOTEBORG, SWEDEN ID DEPENDENCE; MASS AB de Haas - van Alphen (dHvA) measurements of organic superconductors (ET)2X, where ET stands for bis(ethylene)dithiofulvalene (or BEDT-TTF) and X = IBr2, (NH4)Hg(SCN)4 and Cu(NCS)2 are reported. The strong two-dimensionality of the Fermi surface (FS) is clearly seen by the perfect 1/cos(THETA)-behavior of the dHvA frequency. The distinctive kind of beating and the angular dependence of the dHvA signal in beta-(ET)2IBr2 gives clear evidence for a lightly corrupted structure of the FS. Due to the nearly cylinder-shape of the FS the bare band structure effective mass, m(b), also shows a 1/cos(THETA)-dependence which is responsible for spin splitting zeros at certain angles. At these points, where the fundamental amplitude of the dHvA signal is vanishing, m(b) could exactly be determined and by comparison with the independently measured cyclotron effective mass the electron-phonon coupling constant could be estimated. C1 ARGONNE NATL LAB,DIV MAT SCI & CHEM,ARGONNE,IL 60439. RP WOSNITZA, J (reprint author), UNIV KARLSRUHE,INST PHYS,W-7500 KARLSRUHE,GERMANY. NR 23 TC 3 Z9 3 U1 0 U2 0 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE 1 PA PO BOX 564, 1001 LAUSANNE 1, SWITZERLAND SN 0379-6779 J9 SYNTHETIC MET JI Synth. Met. PD APR 5 PY 1993 VL 56 IS 2-3 BP 2891 EP 2898 DI 10.1016/0379-6779(93)90052-X PG 8 WC Materials Science, Multidisciplinary; Physics, Condensed Matter; Polymer Science SC Materials Science; Physics; Polymer Science GA LJ799 UT WOS:A1993LJ79900052 ER PT J AU DRESSEL, M ELDRIDGE, JE WANG, HH GEISER, U WILLIAMS, JM AF DRESSEL, M ELDRIDGE, JE WANG, HH GEISER, U WILLIAMS, JM TI THE INFRARED OPTICAL-PROPERTIES OF THE ALPHA-PHASE ORGANIC SUPERCONDUCTOR, ALPHA-(BEDT-TTF)2(NH4HG(NCS)4) SO SYNTHETIC METALS LA English DT Article; Proceedings Paper CT INTERNATIONAL CONF ON SCIENCE AND TECHNOLOGY OF SYNTHETIC METALS ( ICSM 92 ) CY AUG 12-18, 1992 CL GOTEBORG, SWEDEN ID BEDT-TTF; REFLECTANCE SPECTRA; AMBIENT-PRESSURE; SALTS; (BEDT-TTF)2(NH4)HG(SCN)4; BETA-(BEDT-TTF)2I3; TEMPERATURE; CRYSTAL AB The title compound is the only known organic superconductor (T(c) = 0.8 K) with an alpha-phase crystal structure, in which the conducting plane contains single BEDT-TTF molecules with alternating orientation, rather than the pairs of molecules found in the higher T(c) kappa-phase compounds. We have measured the polarized reflectivity of protonated and deuterated (BEDT-TTF)2(NH4)Hg-(NCS)4, from 80 cm-1 to 8000 cm-1, at temperatures between 6.5 K and 300 K. The overall shape of these spectra are discussed. The optical conductivity obtained after a Kramers-Kronig analysis shows no maximum in the mid-infrared as known from the compounds of the kappa-phase due to the lack of dimerization of the BEDT-TTF molecules. This causes an accentuation of the far-infrared intraband conductivity. The vibrational features are assigned and discussed. C1 ARGONNE NATL LAB,DIV CHEM & MAT SCI,ARGONNE,IL 60439. RP DRESSEL, M (reprint author), UNIV BRITISH COLUMBIA,DEPT PHYS,VANCOUVER V6T 1Z1,BC,CANADA. RI Dressel, Martin/D-3244-2012 NR 18 TC 0 Z9 0 U1 0 U2 0 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE 1 PA PO BOX 564, 1001 LAUSANNE 1, SWITZERLAND SN 0379-6779 J9 SYNTHETIC MET JI Synth. Met. PD APR 5 PY 1993 VL 56 IS 2-3 BP 2923 EP 2926 DI 10.1016/0379-6779(93)90057-4 PG 4 WC Materials Science, Multidisciplinary; Physics, Condensed Matter; Polymer Science SC Materials Science; Physics; Polymer Science GA LJ799 UT WOS:A1993LJ79900057 ER PT J AU CHUNG, M WANG, K WANG, YQ EKLUND, PC BRILL, JW XIANG, XD MOSTOVOY, R HOU, JG ZETTL, A DAVIS, JF GOLDEN, A MEIER, MS SELEGUE, JP AF CHUNG, M WANG, K WANG, YQ EKLUND, PC BRILL, JW XIANG, XD MOSTOVOY, R HOU, JG ZETTL, A DAVIS, JF GOLDEN, A MEIER, MS SELEGUE, JP TI THERMAL-PROPERTIES OF FULLERENES SO SYNTHETIC METALS LA English DT Article; Proceedings Paper CT INTERNATIONAL CONF ON SCIENCE AND TECHNOLOGY OF SYNTHETIC METALS ( ICSM 92 ) CY AUG 12-18, 1992 CL GOTEBORG, SWEDEN ID C60 AB We present the results of specific heat measurements on single crystals of C60 in (pure) fcc and (toluene containing) orthorhombic phases. The orientational ordering phase transitions are at surprisingly close temperatures (260K and 239K) for the two polytypes. The single crystal results are compared with DSC measurements on powders. C1 LAWRENCE BERKELEY LAB,DIV MAT SCI,BERKELEY,CA 94720. UNIV KENTUCKY,DEPT CHEM,LEXINGTON,KY 40506. UNIV CALIF BERKELEY,DEPT PHYS,BERKELEY,CA 94720. RP CHUNG, M (reprint author), UNIV KENTUCKY,DEPT PHYS & ASTRON,LEXINGTON,KY 40506, USA. RI Hou, Jianguo/G-5076-2010; Xiang, Xiaodong/A-9445-2012; Zettl, Alex/O-4925-2016; Wang, Kejin/A-1675-2017 OI Zettl, Alex/0000-0001-6330-136X; Wang, Kejin/0000-0002-7466-3451 NR 11 TC 2 Z9 2 U1 1 U2 3 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE 1 PA PO BOX 564, 1001 LAUSANNE 1, SWITZERLAND SN 0379-6779 J9 SYNTHETIC MET JI Synth. Met. PD APR 5 PY 1993 VL 56 IS 2-3 BP 2985 EP 2990 DI 10.1016/0379-6779(93)90067-7 PG 6 WC Materials Science, Multidisciplinary; Physics, Condensed Matter; Polymer Science SC Materials Science; Physics; Polymer Science GA LJ799 UT WOS:A1993LJ79900067 ER PT J AU WANG, L DAVIDS, PS SAXENA, A BISHOP, AR AF WANG, L DAVIDS, PS SAXENA, A BISHOP, AR TI MAGNETIC RESPONSE OF CERTAIN CURVED GRAPHITIC GEOMETRIES SO SYNTHETIC METALS LA English DT Article; Proceedings Paper CT INTERNATIONAL CONF ON SCIENCE AND TECHNOLOGY OF SYNTHETIC METALS ( ICSM 92 ) CY AUG 12-18, 1992 CL GOTEBORG, SWEDEN ID CARBON AB The quasi-particle energy spectra associated with some members of buckyfamily (curved graphitic geometries), in particular C50, C60, C70 and related fullerenes as well as coaxial helical microtubules of graphite, are obtained analytically within the mean-field approximation. These energy spectra are then used to calculate various response functions. Specifically, we calculate the specific heat, magnetization and magnetic susceptibility in the presence of an external magnetic field at low temperatures. For a single microtubule an extra peak superimposed on the first de Haas van Alphen (dHvA) oscillation in magnetic susceptibility is found in the 50 - 170 Tesla range depending on the radius which is possibly accessible in special (explosive flux compression) experiments. Finally, we point to important potential applications of these novel mesoscopic structures in nanotechnology. RP WANG, L (reprint author), LOS ALAMOS NATL LAB,DIV THEORET,LOS ALAMOS,NM 87545, USA. RI Davids, Paul/D-1550-2010 NR 5 TC 0 Z9 0 U1 2 U2 6 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE 1 PA PO BOX 564, 1001 LAUSANNE 1, SWITZERLAND SN 0379-6779 J9 SYNTHETIC MET JI Synth. Met. PD APR 5 PY 1993 VL 56 IS 2-3 BP 3008 EP 3013 DI 10.1016/0379-6779(93)90071-4 PG 6 WC Materials Science, Multidisciplinary; Physics, Condensed Matter; Polymer Science SC Materials Science; Physics; Polymer Science GA LJ799 UT WOS:A1993LJ79900071 ER PT J AU LANE, PA SWANSON, LS SHINAR, J ENGEL, J BARTON, TJ WHEELOCK, J JONES, L AF LANE, PA SWANSON, LS SHINAR, J ENGEL, J BARTON, TJ WHEELOCK, J JONES, L TI POLARONS AND TRIPLET EXCITONS IN C60 GLASSES AND FILMS - AN OPTICALLY DETECTED MAGNETIC-RESONANCE (ODMR) STUDY SO SYNTHETIC METALS LA English DT Article; Proceedings Paper CT INTERNATIONAL CONF ON SCIENCE AND TECHNOLOGY OF SYNTHETIC METALS ( ICSM 92 ) CY AUG 12-18, 1992 CL GOTEBORG, SWEDEN DE C-60; PHOTOLUMINESCENCE; ODMR; TRIPLET EXCITONS; POLARONS ID ELECTRON-SPIN-RESONANCE; ABSORPTION-SPECTRA; FULLERENES C60; C-60; CARBON; SOLIDS; C70 AB The photoluminescence (PL) and X-band ODMR of C60 films and C60 isolated in a toluene/polystyrene glass matrix (C60:T/PS) is described. The delocalized triplet ODMR of C60:T/PS is similar to previously reported light-induced ESR. In films, however, the ODMR indicates that the delocalized triplet is larger and distorted by neighboring molecules. In addition, another, localized triplet, and a narrow PL-enhancing line at g = 2.0017 +/- 0.0005 are observed. The DELTAm(s) = 2 transitions of these triplets are clearly observed at half-field, i..e, at g - 4. These features are similar to those observed in luminescent pi-conjugated polymers. The former is attributed to a localized triplet of size similar to a 5- or 6-membered ring, possibly on a face adjacent to another C-60 molecule; the latter is believed to result from intermolecular polaron recombination. The possible existence of an additional spin-carrying excited state in films is also discussed. C1 IOWA STATE UNIV SCI & TECHNOL,DEPT CHEM,AMES,IA 50011. IOWA STATE UNIV SCI & TECHNOL,US DOE,AMES LAB,AMES,IA 50011. IOWA STATE UNIV SCI & TECHNOL,DEPT PHYS,AMES,IA 50011. RP LANE, PA (reprint author), US DOE,AMES LAB,AMES,IA 50011, USA. NR 30 TC 0 Z9 0 U1 0 U2 1 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE 1 PA PO BOX 564, 1001 LAUSANNE 1, SWITZERLAND SN 0379-6779 J9 SYNTHETIC MET JI Synth. Met. PD APR 5 PY 1993 VL 56 IS 2-3 BP 3086 EP 3091 DI 10.1016/0379-6779(93)90084-A PG 6 WC Materials Science, Multidisciplinary; Physics, Condensed Matter; Polymer Science SC Materials Science; Physics; Polymer Science GA LJ799 UT WOS:A1993LJ79900084 ER PT J AU SAXENA, A BATISTIC, I ALOUANI, M BISHOP, AR AF SAXENA, A BATISTIC, I ALOUANI, M BISHOP, AR TI ESR-SPECTRA OF PHOTOINDUCED DEFECTS IN MX CHAIN SOLIDS SO SYNTHETIC METALS LA English DT Article; Proceedings Paper CT INTERNATIONAL CONF ON SCIENCE AND TECHNOLOGY OF SYNTHETIC METALS ( ICSM 92 ) CY AUG 12-18, 1992 CL GOTEBORG, SWEDEN ID PLATINUM AB We calculate the electron spin resonance (ESR) spectra associated with the spin carrying nonlinear excitations such as neutral solitons, triplet excitons as well as electron and hole polarons for halogen-bridged mixed-valence transition metal (MX: M=Pt, X=Cl,Br,I) linear chain materials within a discrete, 3/4-filled, two-band, tight-binding extended Peierls-Hubbard model1. The strongly distorted and localized CDW material, PtCl, is contrasted with the weak CDW, delocalised material, PtBr. The hyperfine structure in the ESR spectra arises from the spin density on the Pt atoms while the superhyperfine structure is attributed to a small spin density present on the halogen sublattice. These theoretical predictions are compared with the recent experimental ESR data on photoinduced defects in PtX materials. C1 UNIV ZAGREB,INST PHYS,41001 ZAGREB,CROATIA. OHIO STATE UNIV,DEPT PHYS,COLUMBUS,OH 43210. RP SAXENA, A (reprint author), LOS ALAMOS NATL LAB,INST THEORET,LOS ALAMOS,NM 87545, USA. RI Alouani, Mebarek/A-9101-2011 OI Alouani, Mebarek/0000-0002-7985-5276 NR 10 TC 0 Z9 0 U1 0 U2 0 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE 1 PA PO BOX 564, 1001 LAUSANNE 1, SWITZERLAND SN 0379-6779 J9 SYNTHETIC MET JI Synth. Met. PD APR 5 PY 1993 VL 56 IS 2-3 BP 3329 EP 3334 DI 10.1016/0379-6779(93)90123-E PG 6 WC Materials Science, Multidisciplinary; Physics, Condensed Matter; Polymer Science SC Materials Science; Physics; Polymer Science GA LJ799 UT WOS:A1993LJ79900123 ER PT J AU LOVE, SP WORL, LA DONOHOE, RJ HUCKETT, SC SAXENA, A HUANG, XZ BISHOP, AR SWANSON, BI AF LOVE, SP WORL, LA DONOHOE, RJ HUCKETT, SC SAXENA, A HUANG, XZ BISHOP, AR SWANSON, BI TI RESONANCE RAMAN AND FAR-INFRARED STUDIES OF ISOTOPICALLY DISORDERED AND MIXED-HALIDE HALOGEN-BRIDGED PLATINUM CHAIN SOLIDS SO SYNTHETIC METALS LA English DT Article; Proceedings Paper CT INTERNATIONAL CONF ON SCIENCE AND TECHNOLOGY OF SYNTHETIC METALS ( ICSM 92 ) CY AUG 12-18, 1992 CL GOTEBORG, SWEDEN AB The MX chain solids [Pt(en)2][Pt(en)2X2](ClO4)4, (en = C2H8N2 and X = Cl, Br), referred to as ''PtX,'' are used to explore some of the surprising spectral consequences of disorder in 1-D systems, first for pure PtCl, where the disorder arises from randomly distributed Cl isotopes, then for the more drastic case of the mixed-halide materials PtCl1-xBrx. Lattice dynamics and Peierls-Hubbard modelling are used to analyze the observed spectral behavior. In both cases, the complex structure seen in the Raman and IR spectra is found to arise from strongly localized vibrational modes residing on chain segments, defined by sequences of Cl isotopes for PtCl, and by sequences of Cl and Br for PtCl1-xBrx. C1 LOS ALAMOS NATL LAB,THEORET DIV T-11,LOS ALAMOS,NM 87545. RP LOVE, SP (reprint author), LOS ALAMOS NATL LAB,SPECTROSCOPY GRP INC 14,LOS ALAMOS,NM 87545, USA. NR 9 TC 1 Z9 1 U1 0 U2 2 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE 1 PA PO BOX 564, 1001 LAUSANNE 1, SWITZERLAND SN 0379-6779 J9 SYNTHETIC MET JI Synth. Met. PD APR 5 PY 1993 VL 56 IS 2-3 BP 3335 EP 3340 DI 10.1016/0379-6779(93)90124-F PG 6 WC Materials Science, Multidisciplinary; Physics, Condensed Matter; Polymer Science SC Materials Science; Physics; Polymer Science GA LJ799 UT WOS:A1993LJ79900124 ER PT J AU KURITA, S EGUCHI, S OHTA, S AF KURITA, S EGUCHI, S OHTA, S TI POLARONIC DEFECT STATES IN QUASI-ONE-DIMENSIONAL SOLID WITH MEDIUM ELECTRON-LATTICE COUPLING SYSTEM [PT(EN)2][PT(EN)2BR2](CLO4)4 SO SYNTHETIC METALS LA English DT Article; Proceedings Paper CT INTERNATIONAL CONF ON SCIENCE AND TECHNOLOGY OF SYNTHETIC METALS ( ICSM 92 ) CY AUG 12-18, 1992 CL GOTEBORG, SWEDEN ID SPECTRA AB Photoinduced defect states have been studied for [Pt(en)2][Pt(en)2Br2](ClO4)4 ( en=ethylene-diamine. hereafter abbreviated as PtBr)) and chlorine doped PtBr single crystals synthesized by the improved method. The PtBr which belongs to the medium electron-lattice coupling system has absorption edge of the CT band at 1.45eV at 2K. Two midgap absorption bands located at 1.10eV and 1.23eV due to polaron and small hump (1.36eV) are produced by the photoexcitation. Polarons in the PtBr are trapped near halogen impurities and/or lattice defects with a trapping energy of about 11meV, showing that the polarons are mobile at the temperature as low as 20K. The polarons are delocalized over a significantly large number of PtBr units in the chain, which may cause a broad linewidth in ESR spectrum and also motional narrowing. C1 LOS ALAMOS NATL LAB,INORGAN & STRUCT CHEM GRP INC-4 MC-C345,LOS ALAMOS,NM 87545. FURMAN UNIV,DEPT CHEM,GREENVILLE,SC 29613. RP KURITA, S (reprint author), YOKOHAMA NATL UNIV,FAC ENGN,APPL PHYS LAB,YOKOHAMA,KANAGAWA 240,JAPAN. NR 10 TC 1 Z9 1 U1 0 U2 0 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE 1 PA PO BOX 564, 1001 LAUSANNE 1, SWITZERLAND SN 0379-6779 J9 SYNTHETIC MET JI Synth. Met. PD APR 5 PY 1993 VL 56 IS 2-3 BP 3341 EP 3346 DI 10.1016/0379-6779(93)90125-G PG 6 WC Materials Science, Multidisciplinary; Physics, Condensed Matter; Polymer Science SC Materials Science; Physics; Polymer Science GA LJ799 UT WOS:A1993LJ79900125 ER PT J AU GAMMEL, JT SAXENA, A BISHOP, AR AF GAMMEL, JT SAXENA, A BISHOP, AR TI DYNAMICS AND PHOTOEXCITATION IN MX AND MXX CHAIN SOLIDS SO SYNTHETIC METALS LA English DT Article; Proceedings Paper CT INTERNATIONAL CONF ON SCIENCE AND TECHNOLOGY OF SYNTHETIC METALS ( ICSM 92 ) CY AUG 12-18, 1992 CL GOTEBORG, SWEDEN AB Nonlinear adiabatic dynamics associated with nonlinear excitations in MX and MXX' chain materials are numerically studied within a discrete, 3/4-filled, two-band, tight-binding extended Peierls-Hubbard model. Both Hartree-Fock (HF) adiabatic molecular relaxation and molecular dynamics techniques are employed to investigate the time evolution of solitons, polarons, bipolarons in charge-density-wave (CDW), bond-order-wave (BOW) and spin-density-wave (SDW) ground state materials. Photoexcitations are performed between (i) continuum levels, (ii) localized levels, (iii) continuum and localized levels. The subsequent formation and time evolution of excitons, defect pairs, breathers, and, for the MXX' solids, charge separation are studied in terms of energy levels and distortion patterns. These results we compared with the dynamics of previously studied 1/2-filled, one-band, SSH-type electron-phonon models, used for studying polyenes and polyynes, and experimental data. C1 LOS ALAMOS NATL LAB,DIV THEORET,LOS ALAMOS,NM 87545. LOS ALAMOS NATL LAB,CTR NONLINEAR STUDIES & MAT SCI,LOS ALAMOS,NM 87545. RP GAMMEL, JT (reprint author), NCCOSC,DIV RDT&E NRAD,MAT RES BRANCH,CODE 573,SAN DIEGO,CA 92152, USA. NR 8 TC 1 Z9 1 U1 0 U2 0 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE 1 PA PO BOX 564, 1001 LAUSANNE 1, SWITZERLAND SN 0379-6779 J9 SYNTHETIC MET JI Synth. Met. PD APR 5 PY 1993 VL 56 IS 2-3 BP 3347 EP 3351 DI 10.1016/0379-6779(93)90126-H PG 5 WC Materials Science, Multidisciplinary; Physics, Condensed Matter; Polymer Science SC Materials Science; Physics; Polymer Science GA LJ799 UT WOS:A1993LJ79900126 ER PT J AU ALOUANI, M ALBERS, RC AF ALOUANI, M ALBERS, RC TI MAGNETIC-PROPERTIES OF THE NEUTRAL MX CHAIN SYSTEMS SO SYNTHETIC METALS LA English DT Article; Proceedings Paper CT INTERNATIONAL CONF ON SCIENCE AND TECHNOLOGY OF SYNTHETIC METALS ( ICSM 92 ) CY AUG 12-18, 1992 CL GOTEBORG, SWEDEN ID BAND THEORY; COMPLEXES AB Both local density-functional (LDF) Stoner theory and spin-polarized LDF, each in conjunction with the scalar relativistic linear muffin-tin orbital technique, are used to study the magnetic properties of the neutral halogen-bridged transition-metal linear chains, denoted by MX (M=Ni or Pt, and X=Cl, Br, or I). Both approaches show that the Ni-based compounds axe antiferomagnetic, whereas the Pt-based compounds are paramagnetic. Besides these calculations, we have also studied the magnetism of the MX chain systems using the new density functional, which takes orbital polarization into account and uses a Hubbard interaction instead of the Stoner parameter. Despite the additional sophistication of this approach, very similar results are obtained. C1 LOS ALAMOS NATL LAB,DIV THEORET,LOS ALAMOS,NM 87545. RP ALOUANI, M (reprint author), OHIO STATE UNIV,DEPT PHYS,COLUMBUS,OH 43210, USA. RI Alouani, Mebarek/A-9101-2011 OI Alouani, Mebarek/0000-0002-7985-5276 NR 22 TC 1 Z9 1 U1 0 U2 3 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE 1 PA PO BOX 564, 1001 LAUSANNE 1, SWITZERLAND SN 0379-6779 J9 SYNTHETIC MET JI Synth. Met. PD APR 5 PY 1993 VL 56 IS 2-3 BP 3352 EP 3357 DI 10.1016/0379-6779(93)90127-I PG 6 WC Materials Science, Multidisciplinary; Physics, Condensed Matter; Polymer Science SC Materials Science; Physics; Polymer Science GA LJ799 UT WOS:A1993LJ79900127 ER PT J AU ALOUANI, M ALBERS, RC WILLS, JM AF ALOUANI, M ALBERS, RC WILLS, JM TI CALCULATED HUBBARD INTERACTION IN THE NEUTRAL MX CHAIN SYSTEMS SO SYNTHETIC METALS LA English DT Article; Proceedings Paper CT INTERNATIONAL CONF ON SCIENCE AND TECHNOLOGY OF SYNTHETIC METALS ( ICSM 92 ) CY AUG 12-18, 1992 CL GOTEBORG, SWEDEN ID 2 BAND MODEL; COMPLEXES; STATES; PARAMETERS; LA2CUO4 AB We have performed first-principles local-density-approximation (LDA) electronic-structure calculations of the of the neutral MX chain compounds and fitted their band structures to a two-band tight-binding Hamiltonian. Using two slightly different approaches based on constrained occupancies in the Kohn-Sham LDA, we have calculated from first principles the Hubbard parameters for the neutral halogen-bridged transition-metal (MX) linear chain systems (M = Ni or Pt, and X = Cl, Br, or I). For PtX (X = Cl, Br) the Pt onsite U is almost three times larger than the Pt-X hopping integral, and is almost twice as large for the NiX compounds, which are very strongly correlated and are likely to have a spin-density-wave or antiferromagnetic ground state. C1 LOS ALAMOS NATL LAB,DIV THEORET,LOS ALAMOS,NM 87545. RP ALOUANI, M (reprint author), OHIO STATE UNIV,DEPT PHYS,COLUMBUS,OH 43210, USA. RI Alouani, Mebarek/A-9101-2011 OI Alouani, Mebarek/0000-0002-7985-5276 NR 26 TC 2 Z9 2 U1 0 U2 1 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE 1 PA PO BOX 564, 1001 LAUSANNE 1, SWITZERLAND SN 0379-6779 J9 SYNTHETIC MET JI Synth. Met. PD APR 5 PY 1993 VL 56 IS 2-3 BP 3358 EP 3363 DI 10.1016/0379-6779(93)90128-J PG 6 WC Materials Science, Multidisciplinary; Physics, Condensed Matter; Polymer Science SC Materials Science; Physics; Polymer Science GA LJ799 UT WOS:A1993LJ79900128 ER PT J AU ALOUANI, M ALBERS, RC WILLS, JM SPRINGBORG, M AF ALOUANI, M ALBERS, RC WILLS, JM SPRINGBORG, M TI GROUND-STATE PROPERTIES OF THE PTBR NEUTRAL MX CHAIN COMPOUND SO SYNTHETIC METALS LA English DT Article; Proceedings Paper CT INTERNATIONAL CONF ON SCIENCE AND TECHNOLOGY OF SYNTHETIC METALS ( ICSM 92 ) CY AUG 12-18, 1992 CL GOTEBORG, SWEDEN ID COMPLEXES AB We present first-principles all-electron local-density-approximation calculations of the neutral halogen-bridged transition-metal linear-chain compound (MX chain system) Pt2Br6(NH3)4; the results agree well with the experimental lattice dimerization, band gap, and the Raman breathing mode. C1 OHIO STATE UNIV,DEPT PHYS,COLUMBUS,OH 43210. UNIV CONSTANCE,FAK CHEM,W-7750 CONSTANCE,GERMANY. RP ALOUANI, M (reprint author), LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545, USA. RI Alouani, Mebarek/A-9101-2011 OI Alouani, Mebarek/0000-0002-7985-5276 NR 17 TC 0 Z9 0 U1 0 U2 0 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE 1 PA PO BOX 564, 1001 LAUSANNE 1, SWITZERLAND SN 0379-6779 J9 SYNTHETIC MET JI Synth. Met. PD APR 5 PY 1993 VL 56 IS 2-3 BP 3364 EP 3369 DI 10.1016/0379-6779(93)90129-K PG 6 WC Materials Science, Multidisciplinary; Physics, Condensed Matter; Polymer Science SC Materials Science; Physics; Polymer Science GA LJ799 UT WOS:A1993LJ79900129 ER PT J AU GAMMEL, JT YONEMITSU, K SAXENA, A BISHOP, AR RODER, H AF GAMMEL, JT YONEMITSU, K SAXENA, A BISHOP, AR RODER, H TI ELECTRON-PHONON DRIVEN SPIN FRUSTRATION IN MULTIBAND HUBBARD MODELS - MX CHAINS AND OXIDE SUPERCONDUCTORS SO SYNTHETIC METALS LA English DT Article; Proceedings Paper CT INTERNATIONAL CONF ON SCIENCE AND TECHNOLOGY OF SYNTHETIC METALS ( ICSM 92 ) CY AUG 12-18, 1992 CL GOTEBORG, SWEDEN ID MIXED-VALENCE; COMPLEXES AB We discuss the consequences of both electron-phonon and electron-electron couplings in 1D an 2D multi-band (Peierls-Hubbard) models. After briefly discussing various analytic limits, we focus on (Hartree-Fock and exact) numerical studies in the intermediate regime for both couplings, where unusual spin-Peierls as well as long-period, frustrated ground states are found. Doping into such phases or near the phase boundaries can lead to further interesting phenomena such as separation of spin and charge, a dopant-induced phase transition of the global (parent) phase, or real-space (''bipolaronic'') pairing. We discuss possible experimentally observable consequences of this rich phase diagram for halogen-bridged, transition metal, linear chain complexes (MX chains) in 1D and the oxide superconductors in 2D. C1 UNIV BAYREUTH,INST PHYS,W-8580 BAYREUTH,GERMANY. LOS ALAMOS NATL LAB,CTR NONLINEAR STUDIES & MAT SCI,LOS ALAMOS,NM 87545. LOS ALAMOS NATL LAB,DIV THEORET,LOS ALAMOS,NM 87545. RP GAMMEL, JT (reprint author), NCCOSC,DIV RDT&E NRAD,MAT RES BRANCH,CODE 573,SAN DIEGO,CA 92152, USA. NR 15 TC 1 Z9 1 U1 0 U2 1 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE 1 PA PO BOX 564, 1001 LAUSANNE 1, SWITZERLAND SN 0379-6779 J9 SYNTHETIC MET JI Synth. Met. PD APR 5 PY 1993 VL 56 IS 2-3 BP 3377 EP 3382 DI 10.1016/0379-6779(93)90131-F PG 6 WC Materials Science, Multidisciplinary; Physics, Condensed Matter; Polymer Science SC Materials Science; Physics; Polymer Science GA LJ799 UT WOS:A1993LJ79900131 ER PT J AU SPRINGBORG, M ALBERS, RC AF SPRINGBORG, M ALBERS, RC TI CANIN - A ONE-DIMENSIONAL METAL-CONTAINING MATERIAL SO SYNTHETIC METALS LA English DT Article; Proceedings Paper CT INTERNATIONAL CONF ON SCIENCE AND TECHNOLOGY OF SYNTHETIC METALS ( ICSM 92 ) CY AUG 12-18, 1992 CL GOTEBORG, SWEDEN ID HELICAL POLYMERS AB Results of first-principles density-functional calculations on single chains of NiN, CaNiN, and K2NiN are reported. It is demonstrated that the main features of the true three-dimensional CaNiN material can be understood from a 'single-chain' point of view. The inclusion of the Ca (or K) atoms around the NiN chain leads to noteworthy modifications in the electronic properties, but all materials are metallic. We propose that upon replacing parts of the Ca atoms with other atoms one may vary the electrical conductivity. Finally, our results demonstrate the capability of the LMTO method for helical polymers to describe the properties of transition-metal compounds. C1 LOS ALAMOS NATL LAB,THEORY DIV T-11,LOS ALAMOS,NM 87545. RP SPRINGBORG, M (reprint author), UNIV CONSTANCE,FAK CHEM,W-7750 CONSTANCE,GERMANY. NR 11 TC 3 Z9 3 U1 0 U2 0 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE 1 PA PO BOX 564, 1001 LAUSANNE 1, SWITZERLAND SN 0379-6779 J9 SYNTHETIC MET JI Synth. Met. PD APR 5 PY 1993 VL 56 IS 2-3 BP 3383 EP 3388 DI 10.1016/0379-6779(93)90132-G PG 6 WC Materials Science, Multidisciplinary; Physics, Condensed Matter; Polymer Science SC Materials Science; Physics; Polymer Science GA LJ799 UT WOS:A1993LJ79900132 ER PT J AU SAXENA, A HUANG, XZ GAMMEL, JT BISHOP, AR WORL, LA LOVE, SP SWANSON, BI AF SAXENA, A HUANG, XZ GAMMEL, JT BISHOP, AR WORL, LA LOVE, SP SWANSON, BI TI PHOTOINDUCED CHARGE SEPARATION, INTRINSIC SELF-DOPING AND DEVICE APPLICATIONS OF HETEROJUNCTION MATERIALS - MIXED-HALIDE MX SOLIDS SO SYNTHETIC METALS LA English DT Article; Proceedings Paper CT INTERNATIONAL CONF ON SCIENCE AND TECHNOLOGY OF SYNTHETIC METALS ( ICSM 92 ) CY AUG 12-18, 1992 CL GOTEBORG, SWEDEN AB Halogen-bridged mixed-valence transition metal linear chain complexes or MX chains, M: Pt,Pd,Ni; X: Cl,Br,I) are highly anisotropic, quasi-one-dimensional (QID) materials that are related to conducting polymers, mixed stack charge-transfer salts, and oxide superconductors in terms of their low dimensionality and competing electron-phonon and electron-electron interactions. Each set of counterion and equatorial ligand that holds the MX chains in a three-dimensional array acts as a different ''template'' for the apparently soft PtX chain geometry by determining the M-M distance. Recently we prepared single crystals of mixed-halide MX(x)X1-x' materials which consist of segments of pure MX and MX' producing junctions between the distinct halide segments. We have extensively studied the following three systems: (1) PtClxBr1-x, (2) PtClxI1-x and (3) PtBrI1-x for a variety of concentrations x. For the PtClxBr1-x system we obtained direct spectroscopic evidence for charge separation from resonance Raman (RR) experiments on doped and photoexcited single crystals: electron polarons prefer to locate on the PtBr segment while the hole polarons are trapped within PtCl segments. Theoretical calculations bawd on a two-band Peierls-Hubbard model demonstrate strong hybridization of PtCl and PtBr electronic bands as the driving force for separation. In contrast to PtClxBr1-x, both the PtClxI1-x and the PtBrxI1-x systems exhibit qualitatively different behavior, such as intrinsic ''self doping''. Important photovoltaic device applications of these novel electronic materials are discussed. C1 NAVAL COMMAND,CTR CONTROL & OCEAN SURVEILLANCE,MAT RES BRANCH,DIV RDT&E,SAN DIEGO,CA 92152. LOS ALAMOS NATL LAB,SPECTROSCOPY GRP,LOS ALAMOS,NM 87545. RP SAXENA, A (reprint author), LOS ALAMOS NATL LAB,DIV THEORET,LOS ALAMOS,NM 87545, USA. NR 13 TC 1 Z9 1 U1 0 U2 0 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE 1 PA PO BOX 564, 1001 LAUSANNE 1, SWITZERLAND SN 0379-6779 J9 SYNTHETIC MET JI Synth. Met. PD APR 5 PY 1993 VL 56 IS 2-3 BP 3413 EP 3420 DI 10.1016/0379-6779(93)90137-L PG 8 WC Materials Science, Multidisciplinary; Physics, Condensed Matter; Polymer Science SC Materials Science; Physics; Polymer Science GA LJ799 UT WOS:A1993LJ79900137 ER PT J AU SAXENA, A HUANG, XZ BISHOP, AR AF SAXENA, A HUANG, XZ BISHOP, AR TI COMPOSITIONAL SUPERLATTICES BASED ON PTCL/PTBR MX MATERIALS SO SYNTHETIC METALS LA English DT Article; Proceedings Paper CT INTERNATIONAL CONF ON SCIENCE AND TECHNOLOGY OF SYNTHETIC METALS ( ICSM 92 ) CY AUG 12-18, 1992 CL GOTEBORG, SWEDEN AB We consider theoretically & novel class of composition superlattices consisting of alternating layers of quasi-one-dimensional (QID) MX (halogen-bridged,transition metal) chain materials. In partiCUlar, we have studied a superlattice based on the PtCl/PtBr unit where the Peierls band gap for PtCl is approximately 2.4 eV and approximately 1.5 eV for PtBr. We have calculated electronic properties, optical absorption and vibrational properties (e.g. Raman spectrum) of an MX superlattice using a discrete, two-band, tight-binding Peierls-Hubbard model. The electronic band structure reveals a typical subband structure and varies with the relative lengths of the constituent PtCl and PtBr units. The MX superlattice can be thought of as an analog of a GaAs/GaAlxAs1-x compositional superlattice but with the added feature that the optical, transport and various other physical properties are modified due to the presence of nonlinear excitations (e.g. polarons) in the doped samples. RP SAXENA, A (reprint author), LOS ALAMOS NATL LAB,DIV THEORET,LOS ALAMOS,NM 87545, USA. NR 9 TC 1 Z9 1 U1 0 U2 0 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE 1 PA PO BOX 564, 1001 LAUSANNE 1, SWITZERLAND SN 0379-6779 J9 SYNTHETIC MET JI Synth. Met. PD APR 5 PY 1993 VL 56 IS 2-3 BP 3421 EP 3425 DI 10.1016/0379-6779(93)90138-M PG 5 WC Materials Science, Multidisciplinary; Physics, Condensed Matter; Polymer Science SC Materials Science; Physics; Polymer Science GA LJ799 UT WOS:A1993LJ79900138 ER PT J AU SCOTT, B DONOHOE, RJ LOVE, SP JOHNSON, SR WILKERSON, MP SWANSON, BI AF SCOTT, B DONOHOE, RJ LOVE, SP JOHNSON, SR WILKERSON, MP SWANSON, BI TI CONTROL OF THE CHARGE-DENSITY-WAVE STRENGTH IN MX SOLIDS USING A STRUCTURAL TEMPLATE EFFECT SO SYNTHETIC METALS LA English DT Article; Proceedings Paper CT INTERNATIONAL CONF ON SCIENCE AND TECHNOLOGY OF SYNTHETIC METALS ( ICSM 92 ) CY AUG 12-18, 1992 CL GOTEBORG, SWEDEN ID CRYSTAL-STRUCTURE; COMPLEXES; COMPOUND; CHAIN AB A series of materials of stoichiometry [Pt(L-L)2Cl2][Pt(L-L)2]Y4, with L-L = amine and Y = counterion, were synthesized and characterized employing X-ray diffraction and resonance Raman spectroscopy. These solids contain one-dimensional chains of alternating metal and halogen atoms that have undergone a Peierls distortion and charge disproportionation, producing alternating valence states on the metals along the chain axis: X-Pt(IV)-Cl ... Pt(II) Cl. It was discovered that the electronic and optical properties of these one-dimensional materials could be widely controlled through employing different combinations of L-L and Y; templates composed of hydrogen bonded networks of L-L and Y were used to control Cl-Pt(II)-Cl ... Pt(IV) ... Cl chain geometry. Relationships between the charge-density-wave strength (measured as the ratio of the long Pt(II) ... Cl distance to the short Pt(IV)-Cl distance) and band gap energy, Pt-Pt separation, and Pt-Cl stretching frequency were developed. This work has provided a wealth of information for many-body theoretical calculations modeling electron-electron and electron-phonon interactions in one-dimensional materials. RP SCOTT, B (reprint author), LOS ALAMOS NATL LAB,MOLEC SCI GRP INC-14,LOS ALAMOS,NM 87545, USA. RI Scott, Brian/D-8995-2017 OI Scott, Brian/0000-0003-0468-5396 NR 20 TC 7 Z9 7 U1 1 U2 3 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE 1 PA PO BOX 564, 1001 LAUSANNE 1, SWITZERLAND SN 0379-6779 J9 SYNTHETIC MET JI Synth. Met. PD APR 5 PY 1993 VL 56 IS 2-3 BP 3426 EP 3431 DI 10.1016/0379-6779(93)90139-N PG 6 WC Materials Science, Multidisciplinary; Physics, Condensed Matter; Polymer Science SC Materials Science; Physics; Polymer Science GA LJ799 UT WOS:A1993LJ79900139 ER PT J AU SCOTT, B JOHNSON, SR SWANSON, BI AF SCOTT, B JOHNSON, SR SWANSON, BI TI A STRUCTURAL STUDY OF CHARGE-DENSITY-WAVE PERTURBATIONS IN MIXED-HALIDE MX SOLIDS SO SYNTHETIC METALS LA English DT Article; Proceedings Paper CT INTERNATIONAL CONF ON SCIENCE AND TECHNOLOGY OF SYNTHETIC METALS ( ICSM 92 ) CY AUG 12-18, 1992 CL GOTEBORG, SWEDEN ID CRYSTAL-STRUCTURE AB Mixed-halide crystals have been formed by co-crystallizing pure [Pt(en)2Cl2][Pt(en)2](ClO4)4 (PtCl) and [Pt(en)2I2][Pt(en)2](ClO4)4 (PtI), where en=1,2 diaminoethane. Single crystal X-ray diffraction reveals that these crystals are of high quality. The pure PtI and PtCl materials contain chains of alternating Pt and halogen atoms that have undergone a Peierls distortion and commensurate charge disproportionation, resulting in alternating valence states on the platinum atoms: X-Pt(IV)-X...Pt(II)...X. The Peierls distortion results in a charge-density-wave (CDW), the strength of which is measured as the ratio, rho, of the short Pt(IV)-X bond distance to the long Pt(II) ... X bond distance. PtCl is a strong CDW system with rho=0.750 and PtI is a weak CDW system with rho=0.919. The mixed-halide systems have the stoichiometry PtCl1-xIx, with x=0.1, 0.15, 0.2, 0.3, 0.7, 0.8, 0.85, and 0.90. A Chain lattice constant versus compositon study strongly suggests distorted PtI and PtCl chains in these solids. A single crystal diffraction study on PtCl0.85I0.15 shows significant perturbations in the PtCl and PtI chain CDW strengths, with the PtI segment showing no Peierls distortion (rho=1). This control of the CDW strength, which is strongly tied to electron-electron and electron-phonon interactions in these solids, potentially allows tuning of electronic and optical properties on a nanometer scale. RP SCOTT, B (reprint author), LOS ALAMOS NATL LAB,SPECTROSCOPY GRP INC-14,LOS ALAMOS,NM 87545, USA. RI Scott, Brian/D-8995-2017 OI Scott, Brian/0000-0003-0468-5396 NR 8 TC 5 Z9 5 U1 1 U2 1 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE 1 PA PO BOX 564, 1001 LAUSANNE 1, SWITZERLAND SN 0379-6779 J9 SYNTHETIC MET JI Synth. Met. PD APR 5 PY 1993 VL 56 IS 2-3 BP 3432 EP 3437 DI 10.1016/0379-6779(93)90140-R PG 6 WC Materials Science, Multidisciplinary; Physics, Condensed Matter; Polymer Science SC Materials Science; Physics; Polymer Science GA LJ799 UT WOS:A1993LJ79900140 ER PT J AU HUANG, XZ SAXENA, A BISHOP, AR AF HUANG, XZ SAXENA, A BISHOP, AR TI DOPING-INDUCED INSULATOR-METAL TRANSITION IN THE PLATINUM-BASED MX COMPLEXES SO SYNTHETIC METALS LA English DT Article; Proceedings Paper CT INTERNATIONAL CONF ON SCIENCE AND TECHNOLOGY OF SYNTHETIC METALS ( ICSM 92 ) CY AUG 12-18, 1992 CL GOTEBORG, SWEDEN AB Platinum halide linear chain MX (X=Cl, Br, I) complexes exhibit various strengths of the charge-density-wave (CDW) ground state. One way of characterizing the strength is to study the response to charge doping. On a finite length chain, we found that PtCl preserves its CDW pattern while forming a polaron array when doped; PtI is rapidly unstable against charge doping and undergoes an insulator-metal transition easily; PtBr is in between PtCl and PtI. These trends are consistent with the CDW strength, which is strong for PtCl, medium for PtBr and very weak for PtI. RP HUANG, XZ (reprint author), LOS ALAMOS NATL LAB,DIV THEORET,LOS ALAMOS,NM 87545, USA. NR 7 TC 1 Z9 1 U1 0 U2 0 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE 1 PA PO BOX 564, 1001 LAUSANNE 1, SWITZERLAND SN 0379-6779 J9 SYNTHETIC MET JI Synth. Met. PD APR 5 PY 1993 VL 56 IS 2-3 BP 3438 EP 3442 DI 10.1016/0379-6779(93)90141-I PG 5 WC Materials Science, Multidisciplinary; Physics, Condensed Matter; Polymer Science SC Materials Science; Physics; Polymer Science GA LJ799 UT WOS:A1993LJ79900141 ER PT J AU HUANG, XZ BATISTIC, I BISHOP, AR AF HUANG, XZ BATISTIC, I BISHOP, AR TI IONIC INTERACTION IN A PLATINUM CHLORIDE LINEAR-CHAIN - PTCL SO SYNTHETIC METALS LA English DT Article; Proceedings Paper CT INTERNATIONAL CONF ON SCIENCE AND TECHNOLOGY OF SYNTHETIC METALS ( ICSM 92 ) CY AUG 12-18, 1992 CL GOTEBORG, SWEDEN AB We have modified our previous model of MX chain materials to better describe the highly valence localized platinum chloride linear chain compounds, e.g., PtCl. The nearest neighbor Coulomb attraction and metal ion-ion electrostatic repulsion are added to our previous Hamiltonian. These two interactions play two roles: generating (i) an effective anharmonic intra-site electron-phonon coupling (therefore leading to the formation of charge-density-wave even if the inter-site electron-phonon coupling is weak) and (ii) acting as an effective elastic force between neighboring Pt and Cl atoms. Uniform and various defect states (polaron, bi-polaron and exciton) have been studied within this framework by computing their optical absorption, resonance Raman (RR) and infrared spectra. The results agree with the experimental data very well. Buckling of Cl atoms out of the chain is found to be important in order to obtain correct frequencies of RR modes of electron polarons and bi-polarons. C1 UNIV ZAGREB,INST PHYS,41001 ZAGREB,CROATIA. RP HUANG, XZ (reprint author), LOS ALAMOS NATL LAB,DIV THEORET,LOS ALAMOS,NM 87545, USA. NR 7 TC 2 Z9 2 U1 0 U2 1 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE 1 PA PO BOX 564, 1001 LAUSANNE 1, SWITZERLAND SN 0379-6779 J9 SYNTHETIC MET JI Synth. Met. PD APR 5 PY 1993 VL 56 IS 2-3 BP 3443 EP 3448 DI 10.1016/0379-6779(93)90142-J PG 6 WC Materials Science, Multidisciplinary; Physics, Condensed Matter; Polymer Science SC Materials Science; Physics; Polymer Science GA LJ799 UT WOS:A1993LJ79900142 ER PT J AU HUANG, XZ SAXENA, A BISHOP, AR SCOTT, BL SWANSON, BI AF HUANG, XZ SAXENA, A BISHOP, AR SCOTT, BL SWANSON, BI TI INTRINSIC CHARGE-TRANSFER IN THE MIXED HALIDE PTCLXI1-X LINEAR-CHAIN SOLIDS SO SYNTHETIC METALS LA English DT Article; Proceedings Paper CT INTERNATIONAL CONF ON SCIENCE AND TECHNOLOGY OF SYNTHETIC METALS ( ICSM 92 ) CY AUG 12-18, 1992 CL GOTEBORG, SWEDEN AB In this paper, we report theoretical results on an intrinsic charge transfer effect which possibly occurs in the mixed halide linear chain compound: PtClxI1-x. PtCl and PtI are two of a family of mixed-valence-transition-metal linear chain compounds: [M2(en)4X2]Y4 (M = Pt, Pd, Ni, X = Cl, Br, I, en denotes the ethylenediamine ligand, and Y is a counter-ion (such as ClO4-) to neutralize the chain). The respective pure chains are identified to have charge-density-wave (CDW) ground states, with strong and weak CDW strengths for PtCl and PtI, respectively. Our modeling suggests that when PtI and PtCl are mixed, electrons spontaneously transfer from the PtI segment to the PtCl segment. This charge transfer results in the formation of localized electron bi-polarons in the PtCl segment and of extended hole bi-polarons in the PtI segment. As in classical p - n junctions, the driving force for this phenomenon arises from the fact that the Pt valence band of PtI is higher in energy than the Pt conduction band of PtCl. The energy gain through the charge transfer is large enough to overcome the elastic energy cost from the change of CDW dimerization pattern in both segments. Preliminary experimental result on the crystal structure of PtClxI1-x is consistent with the present theory. C1 LOS ALAMOS NATL LAB,SPECTROSCOPY GRP,LOS ALAMOS,NM 87545. RP HUANG, XZ (reprint author), LOS ALAMOS NATL LAB,DIV THEORET,LOS ALAMOS,NM 87545, USA. RI Scott, Brian/D-8995-2017 OI Scott, Brian/0000-0003-0468-5396 NR 7 TC 2 Z9 2 U1 1 U2 1 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE 1 PA PO BOX 564, 1001 LAUSANNE 1, SWITZERLAND SN 0379-6779 J9 SYNTHETIC MET JI Synth. Met. PD APR 5 PY 1993 VL 56 IS 2-3 BP 3449 EP 3455 DI 10.1016/0379-6779(93)90143-K PG 7 WC Materials Science, Multidisciplinary; Physics, Condensed Matter; Polymer Science SC Materials Science; Physics; Polymer Science GA LJ799 UT WOS:A1993LJ79900143 ER PT J AU LOVE, SP WORL, LA DONOHOE, RJ HUCKETT, SC JOHNSON, SR SWANSON, BI AF LOVE, SP WORL, LA DONOHOE, RJ HUCKETT, SC JOHNSON, SR SWANSON, BI TI FAR-INFRARED AND RESONANCE RAMAN-SPECTROSCOPY AND ISOTOPIC-SUBSTITUTION STUDIES OF HALOGEN-BRIDGED PLATINUM CHAIN SOLIDS SO SYNTHETIC METALS LA English DT Article; Proceedings Paper CT INTERNATIONAL CONF ON SCIENCE AND TECHNOLOGY OF SYNTHETIC METALS ( ICSM 92 ) CY AUG 12-18, 1992 CL GOTEBORG, SWEDEN AB Here we review our most recent results on the vibrational spectroscopy of the MX chain solids [Pt(en)2][Pt(en)2X2](ClO4)4, (X=Cl, Br or I, and en = C2Hg8N2), referred to as PtX. Isotopic substitutions are used to clarify die nature of various vibrational modes. For Raman spectroscopy, fundamental phonon frequencies are determined, when possible, by excitation far below the band edge using a Ti:Sapphire laser, thus avoiding defect production, while photo-induced defects are studied specifically after intentional production. RP LOVE, SP (reprint author), LOS ALAMOS NATL LAB,SPECTROSCOPY GRP INC-14,LOS ALAMOS,NM 87545, USA. NR 11 TC 0 Z9 0 U1 0 U2 3 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE 1 PA PO BOX 564, 1001 LAUSANNE 1, SWITZERLAND SN 0379-6779 J9 SYNTHETIC MET JI Synth. Met. PD APR 5 PY 1993 VL 56 IS 2-3 BP 3456 EP 3460 DI 10.1016/0379-6779(93)90144-L PG 5 WC Materials Science, Multidisciplinary; Physics, Condensed Matter; Polymer Science SC Materials Science; Physics; Polymer Science GA LJ799 UT WOS:A1993LJ79900144 ER PT J AU KESHAVAMURTHY, S MILLER, WH AF KESHAVAMURTHY, S MILLER, WH TI A SEMICLASSICAL MODEL TO INCORPORATE MULTIDIMENSIONAL TUNNELING IN CLASSICAL TRAJECTORY SIMULATIONS USING LOCALLY CONSERVED ACTIONS SO CHEMICAL PHYSICS LETTERS LA English DT Article ID NONSEPARABLE SYSTEMS; TRANSITION-STATE; FALSE VACUUM; APPROXIMATION; DYNAMICS; BATH; FATE AB Earlier work, within the context of transition state theory, has shown that tunneling through the saddle point region of a potential energy surface can be characterized by locally conserved action variables associated with the saddle point (transition state). The present Letter shows how this idea can be combined with classical trajectory simulation methods and thus allow tunneling effects to be incorporated into a much wider class of dynamical processes. Application of this approach to a two-dimensional model unimolecular decay potential gives good results over a wide range of system parameters. C1 LAWRENCE BERKELEY LAB,DIV CHEM SCI,BERKELEY,CA 94720. RP KESHAVAMURTHY, S (reprint author), UNIV CALIF BERKELEY,DEPT CHEM,BERKELEY,CA 94720, USA. NR 26 TC 24 Z9 24 U1 0 U2 2 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 APR 2 PY 1993 VL 205 IS 1 BP 96 EP 101 DI 10.1016/0009-2614(93)85173-L PG 6 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA KU546 UT WOS:A1993KU54600017 ER PT J AU DICKERSON, MT SHUGART, J AF DICKERSON, MT SHUGART, J TI A SIMPLE ALGORITHM FOR ENUMERATING LONGEST DISTANCES IN THE PLANE SO INFORMATION PROCESSING LETTERS LA English DT Article DE ALGORITHMS; COMPUTATIONAL GEOMETRY AB We present a deterministic algorithm that takes as input a set of n points in the plane and enumerates in descending order the k longest distances between pairs of points. The algorithm works for all L(p) distance metrics, requires O(n + K) space and, for uniform distributions over natural containing shapes, has expected-case running time of O(n log n + k log k log n/log log n). C1 LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550. UNIV CALIF DAVIS,DAVIS,CA 95616. RP DICKERSON, MT (reprint author), MIDDLEBURY COLL,DEPT MATH & COMP SCI,MIDDLEBURY,VT 05753, 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 0020-0190 J9 INFORM PROCESS LETT JI Inf. Process. Lett. PD APR 2 PY 1993 VL 45 IS 5 BP 269 EP 274 DI 10.1016/0020-0190(93)90215-U PG 6 WC Computer Science, Information Systems SC Computer Science GA KW208 UT WOS:A1993KW20800009 ER PT J AU MCPHERSON, DW DEHAVENHUDKINS, DL CALLAHAN, AP KNAPP, FF AF MCPHERSON, DW DEHAVENHUDKINS, DL CALLAHAN, AP KNAPP, FF TI SYNTHESIS AND BIODISTRIBUTION OF IODINE-125-LABELED 1-AZABICYCLO[2.2.2]OCT-3-YL ALPHA-HYDROXY-ALPHA-(1-IODO-1-PROPEN-3-YL)-ALPHA-PHENYLACETATE - A NEW LIGAND FOR THE POTENTIAL IMAGING OF MUSCARINIC RECEPTORS BY SINGLE PHOTON-EMISSION COMPUTED-TOMOGRAPHY SO JOURNAL OF MEDICINAL CHEMISTRY LA English DT Article ID CEREBRAL PERFUSION AGENTS; ALZHEIMERS-DISEASE; 3-QUINUCLIDINYL BENZILATE; ACETYLCHOLINE-RECEPTORS; ACID ANALOGS; CONVENIENT PREPARATION; CHOLINERGIC RECEPTORS; BIOLOGICAL EVALUATION; OPTICAL ISOMERS; FATTY-ACIDS AB 1-Azabicyclo[2.2.2]oct-3-yl alpha-hydroxy-alpha-(1-iodo-1-propen-3-yl)-alpha-phenylacetate (IQNP, 3), an analogue of QNB in which a phenyl ring has been replaced with an iodopropenyl substituent, was prepared and evaluated in vitro and in vivo for m-AChR selectivity and specificity. High specific activity [125]IQNP ([I-125]-3) was synthesized in greater than 60% yield utilizing an electrophilic iododestannylation reaction with hydrogen peroxide for the oxidation of iodide. In in vitro receptor binding studies, 3 demonstrated high affinity for M1 (K(i) = 0.78 nM), M2 (K(i) = 1.06 nM), and M3 (K(i) = 0.27 nM) subtypes. In vivo biodistribution studies in female rats [I-125]-3 demonstrated high uptake in areas rich in muscarinic receptors such as the brain (cortex and striatum) and the heart. Blocking studies were performed with a series of receptor specific agents and demonstrated that the uptake of [I-125]-3 was selective and specific for cerebral muscarinic receptor rich areas and that the binding to m-AChR is reversible. The high-yield preparation and specificity and selectivity of high specific activity [I-125]IQNP for muscarinic receptors suggest that this is an attractive new agent for potential imaging of cerebral receptors using single photon tomographic imaging (SPECT). C1 STERLING WINTHROP PHARMACEUT RES DIV,DEPT ENZYMOL & RECEPTOR BIOCHEM,MALVERN,PA 19355. RP MCPHERSON, DW (reprint author), OAK RIDGE NATL LAB,NUCL MED GRP,OAK RIDGE,TN 37831, USA. NR 41 TC 32 Z9 32 U1 1 U2 2 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0022-2623 J9 J MED CHEM JI J. Med. Chem. PD APR 2 PY 1993 VL 36 IS 7 BP 848 EP 854 DI 10.1021/jm00059a009 PG 7 WC Chemistry, Medicinal SC Pharmacology & Pharmacy GA KV705 UT WOS:A1993KV70500009 PM 8464039 ER PT J AU DAVIS, JG BENNETT, WR BRADY, JV BRENT, RL GORDIS, L GORDON, WE GREENHOUSE, SW REITER, RJ STEIN, GS SUSSKIND, C TRICHOPOULOS, D AF DAVIS, JG BENNETT, WR BRADY, JV BRENT, RL GORDIS, L GORDON, WE GREENHOUSE, SW REITER, RJ STEIN, GS SUSSKIND, C TRICHOPOULOS, D TI EMF AND CANCER SO SCIENCE LA English DT Letter C1 HARVARD UNIV,SCH PUBL HLTH,DEPT EPIDEMIOL,BOSTON,MA 02115. YALE UNIV,DEPT APPL PHYS,NEW HAVEN,CT 06520. JOHNS HOPKINS UNIV,SCH MED,DEPT PSYCHIAT & BEHAV BIOL,BALTIMORE,MD 21205. AI DUPONT INST,DIV DEV BIOL,WILMINGTON,DE. THOMAS JEFFERSON UNIV,JEFFERSON MED COLL,PHILADELPHIA,PA 19107. JOHNS HOPKINS UNIV,SCH HYG & PUBL HLTH,DEPT EPIDEMIOL,BALTIMORE,MD 21218. JOHNS HOPKINS UNIV,SCH MED,DEPT PEDIAT,BALTIMORE,MD 21205. RICE UNIV,DEPT SPACE PHYS,HOUSTON,TX 77251. GEORGE WASHINGTON UNIV,DEPT STAT,WASHINGTON,DC 20052. UNIV TEXAS,HLTH SCI CTR,DEPT CELLULAR & STRUCT BIOL,SAN ANTONIO,TX 78284. UNIV MASSACHUSETTS,MED CTR,DEPT CELL BIOL,WORCESTER,MA 01605. UNIV CALIF BERKELEY,DEPT BIOENGN,BERKELEY,CA 94720. RP DAVIS, JG (reprint author), OAK RIDGE ASSOCIATED UNIV,DIV MED SCI,OAK RIDGE,TN 37830, USA. NR 5 TC 3 Z9 3 U1 0 U2 0 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 SN 0036-8075 J9 SCIENCE JI Science PD APR 2 PY 1993 VL 260 IS 5104 BP 13 EP 14 PG 2 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA KV423 UT WOS:A1993KV42300002 ER PT J AU FISK, Z AEPPLI, G AF FISK, Z AEPPLI, G TI SUPERSTRUCTURES AND SUPERCONDUCTIVITY SO SCIENCE LA English DT Editorial Material ID HEAVY-FERMION SUPERCONDUCTORS; MAGNETIC-FIELD; PHASE-DIAGRAM; SYSTEM UPT3; ORDER; FLUCTUATIONS; TRANSPORT; STATES; UBE13; SOUND C1 AT&T BELL LABS,MURRAY HILL,NJ 07974. LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545. RP FISK, Z (reprint author), UNIV CALIF SAN DIEGO,DEPT PHYS,LA JOLLA,CA 92093, USA. NR 38 TC 15 Z9 15 U1 0 U2 5 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 SN 0036-8075 J9 SCIENCE JI Science PD APR 2 PY 1993 VL 260 IS 5104 BP 38 EP 39 DI 10.1126/science.260.5104.38 PG 2 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA KV423 UT WOS:A1993KV42300020 PM 17793531 ER PT J AU REDDY, NRS KOLACZKOWSKI, SV SMALL, GJ AF REDDY, NRS KOLACZKOWSKI, SV SMALL, GJ TI A PHOTOINDUCED PERSISTENT STRUCTURAL TRANSFORMATION OF THE SPECIAL PAIR OF A BACTERIAL REACTION CENTER SO SCIENCE LA English DT Article ID PHOTOSYNTHETIC REACTION CENTERS; ENERGY-TRANSFER DYNAMICS; ELECTRON-DONOR STATE; B800-B850 ANTENNA COMPLEX; X-RAY CRYSTALLOGRAPHY; HOLE-BURNED SPECTRA; RHODOPSEUDOMONAS-VIRIDIS; LOW-TEMPERATURE; RHODOBACTER-SPHAEROIDES; AMORPHOUS SOLIDS AB Structural modification of photosynthetic reaction centers is an important approach for understanding their charge-separation processes. An unprecedented persistent structural transformation of the special pair (dimer) of bacteriochlorophyll molecules can be produced by light absorption alone. The nonphotochemical hole-burned spectra for the reaction center of Rhodopseudomonas viridis show that the phototransformation leads to a red shift of 150 wave numbers for the special pair's lowest energy absorption band, P960, and a comparable blue shift for a state at 850 nanometers, which can now be definitively assigned as being most closely associated with the upper dimer component. Additional insights on excited-state electronic structure include the identification of a new state. C1 IOWA STATE UNIV SCI & TECHNOL,DEPT CHEM,AMES,IA 50011. RP REDDY, NRS (reprint author), IOWA STATE UNIV SCI & TECHNOL,AMES LAB,AMES,IA 50011, USA. NR 46 TC 51 Z9 52 U1 1 U2 3 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 SN 0036-8075 J9 SCIENCE JI Science PD APR 2 PY 1993 VL 260 IS 5104 BP 68 EP 71 DI 10.1126/science.260.5104.68 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA KV423 UT WOS:A1993KV42300027 PM 17793534 ER PT J AU SWEENEY, JJ BURNHAM, AK AF SWEENEY, JJ BURNHAM, AK TI IMPLICATIONS FOR ORGANIC MATURATION STUDIES OF EVIDENCE FOR A GEOLOGICALLY RAPID INCREASE AND STABILIZATION OF VITRINITE REFLECTANCE AT PEAK TEMPERATURE - CERRO-PRIETO GEOTHERMAL SYSTEM, MEXICO - DISCUSSION SO AAPG BULLETIN-AMERICAN ASSOCIATION OF PETROLEUM GEOLOGISTS LA English DT Discussion ID CHEMICAL KINETIC-MODEL RP SWEENEY, JJ (reprint author), LAWRENCE LIVERMORE NATL LAB,POB 808,L-208,LIVERMORE,CA 94550, USA. NR 8 TC 3 Z9 3 U1 0 U2 1 PU AMER ASSOC PETROLEUM GEOLOGIST PI TULSA PA 1444 S BOULDER AVE, PO BOX 979, TULSA, OK 74101 SN 0149-1423 J9 AAPG BULL JI AAPG Bull.-Am. Assoc. Petr. Geol. PD APR PY 1993 VL 77 IS 4 BP 665 EP 667 PG 3 WC Energy & Fuels; Engineering, Petroleum; Geosciences, Multidisciplinary SC Energy & Fuels; Engineering; Geology GA KY035 UT WOS:A1993KY03500012 ER PT J AU MILLER, WH AF MILLER, WH TI BEYOND TRANSITION-STATE THEORY - A RIGOROUS QUANTUM-THEORY OF CHEMICAL-REACTION RATES SO ACCOUNTS OF CHEMICAL RESEARCH LA English DT Review ID KOHN VARIATIONAL PRINCIPLE; CLASSICAL S-MATRIX; PSEUDOSPECTRAL METHOD; RATE CONSTANTS; SCATTERING; EQUATIONS; MOLECULES; MODEL C1 LAWRENCE BERKELEY LAB,DIV CHEM SCI,BERKELEY,CA 94720. RP MILLER, WH (reprint author), UNIV CALIF BERKELEY,DEPT CHEM,BERKELEY,CA 94720, USA. NR 43 TC 125 Z9 125 U1 4 U2 14 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0001-4842 J9 ACCOUNTS CHEM RES JI Accounts Chem. Res. PD APR PY 1993 VL 26 IS 4 BP 174 EP 181 DI 10.1021/ar00028a007 PG 8 WC Chemistry, Multidisciplinary SC Chemistry GA KY068 UT WOS:A1993KY06800007 ER PT J AU YOO, MH SASS, SL FU, CL MILLS, MJ DIMIDUK, DM GEORGE, EP AF YOO, MH SASS, SL FU, CL MILLS, MJ DIMIDUK, DM GEORGE, EP TI DEFORMATION AND FRACTURE OF INTERMETALLICS SO ACTA METALLURGICA ET MATERIALIA LA English DT Review ID QUANTUM-MECHANICAL CALCULATION; GRAIN-BOUNDARIES; YIELD STRESS; NI3AL; METALS; BORON; ALLOYS AB Recent advances in our understanding of the fundamental mechanisms of strength and ductility in ordered intermetallic alloys are summarized. State of the art experimental techniques and innovative computational advances have together stimulated the current activity in this field and opened new opportunities for research. The current status and scientific issues in the area of bulk and defect properties, deformation and strengthening mechanisms, and fracture and toughening mechanisms are assessed, Future research areas of major importance for understanding of deformation and fracture behavior in intermetallic compounds are identified. C1 CORNELL UNIV, DEPT MAT SCI & ENGN, ITHACA, NY 14853 USA. SANDIA NATL LABS, DEPT MAT, LIVERMORE, CA 94551 USA. WRIGHT LAB, MAT DIRECTORATE, WL MLLM, WRIGHT PATTERSON AFB, OH 45433 USA. RP YOO, MH (reprint author), OAK RIDGE NATL LAB, DIV MET & CERAM, OAK RIDGE, TN 37831 USA. RI George, Easo/L-5434-2014 NR 68 TC 75 Z9 77 U1 1 U2 7 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0956-7151 J9 ACTA METALL MATER JI Acta Metall. Mater. PD APR PY 1993 VL 41 IS 4 BP 987 EP 1002 DI 10.1016/0956-7151(93)90148-L PG 16 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA KT083 UT WOS:A1993KT08300001 ER PT J AU HAZZLEDINE, PM SCHNEIBEL, JH AF HAZZLEDINE, PM SCHNEIBEL, JH TI THEORY OF COBLE CREEP FOR IRREGULAR GRAIN STRUCTURES SO ACTA METALLURGICA ET MATERIALIA LA English DT Article ID DIFFUSIONAL CREEP; BOUNDARIES AB Coble creep occurs by the diffusion of matter along grain boundaries. Under the action of an externally applied stress, matter diffuses from grain boundaries in compression to those in tension. Individual grains elongate and macroscopic creep ensues. To date, Coble creep has been derived only for simple periodic grain structures. In this work we show how to solve the Coble creep problem for irregular, two-dimensional grain structures consisting of straight grain boundary segments connected by triple points. Since the normal stress distributions at the grain boundaries are represented by cubic polynomials, 4n(gb) constants have to be determined for a two-dimensional grain structure consisting of n(gb) grain boundary segments. We show how the corresponding system of 4n(gb) equations can be set up for freely chosen boundary conditions at the grain boundary-surface intersections. Several calculated examples with clusters consisting of 25 grains illustrate the power of the technique. C1 OAK RIDGE NATL LAB, OAK RIDGE, TN 37831 USA. RP HAZZLEDINE, PM (reprint author), UNIVERSAL ENERGY SYST, 4401 DAYTON XENIA RD, DAYTON, OH 45432 USA. NR 9 TC 33 Z9 33 U1 1 U2 4 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0956-7151 J9 ACTA METALL MATER JI Acta Metall. Mater. PD APR PY 1993 VL 41 IS 4 BP 1253 EP 1262 DI 10.1016/0956-7151(93)90176-S PG 10 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA KT083 UT WOS:A1993KT08300029 ER PT J AU MILLER, RH RASMUSSEN, CE GOMBOSI, TI WINSKE, D AF MILLER, RH RASMUSSEN, CE GOMBOSI, TI WINSKE, D TI HYBRID SIMULATIONS OF PLASMASPHERIC REFILLING INCLUDING CONVECTION AND INJECTION SO ADVANCES IN SPACE RESEARCH-SERIES LA English DT Article AB The interactions between upflowing thermal ions from conjugate ionospheres are modeled using a 1-dimensional hybrid particle code. The simulation model allows for multiple species, convection of plasmaspheric flux tubes, and Coulomb self collisions which conserve momentum and energy. Plasmaspheric refilling is studied, in which convection of the plasmaspheric flux tube and particle injection from an external source is included. The interaction of ionospheric thermal plasma and the injected plasma seems to play an important role in the evolution of the total particle distribution on the early time scales (t < 1 hour). C1 LOS ALAMOS NATL LAB, DIV APPL THEORET PHYS, LOS ALAMOS, NM 87545 USA. RP UNIV MICHIGAN, DEPT ATMOSPHER OCEAN & SPACE SCI, SPACE PHYS RES LAB, ANN ARBOR, MI 48109 USA. RI Gombosi, Tamas/G-4238-2011 OI Gombosi, Tamas/0000-0001-9360-4951 NR 10 TC 2 Z9 2 U1 0 U2 0 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0273-1177 J9 ADV SPACE RES-SERIES JI Adv. Space Res. PD APR PY 1993 VL 13 IS 4 BP 117 EP 120 PG 4 WC Astronomy & Astrophysics; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences SC Astronomy & Astrophysics; Geology; Meteorology & Atmospheric Sciences GA KV092 UT WOS:A1993KV09200018 ER PT J AU MORELLI, JP BUNTING, RJ COWLEY, SWH FARRUGIA, CJ FREEMAN, MP FRIISCHRISTENSEN, E JONES, GOL LESTER, M LEWIS, RV LUHR, H ORR, D PINNOCK, M REEVES, GD WILLIAMS, PJS YEOMAN, TK AF MORELLI, JP BUNTING, RJ COWLEY, SWH FARRUGIA, CJ FREEMAN, MP FRIISCHRISTENSEN, E JONES, GOL LESTER, M LEWIS, RV LUHR, H ORR, D PINNOCK, M REEVES, GD WILLIAMS, PJS YEOMAN, TK TI PLASMA-FLOW BURSTS IN THE NIGHTSIDE AURORAL-ZONE IONOSPHERE AND THEIR RELATION TO GEOMAGNETIC-ACTIVITY SO ADVANCES IN SPACE RESEARCH-SERIES LA English DT Article ID EISCAT AB We examine the nature of flows in the nightside auroral zone ionosphere and their relationship with concurrent geomagnetic activity by studying a three-hour interval of ground-based radar, magnetometer array and spacecraft data. We find that the flows are bursty in nature, a characteristic previously reported, and that the bursts are related to a series of substorm electrojet intensifications initiated in the pre-midnight sector. C1 NASA, GODDARD SPACE FLIGHT CTR, GODDARD SFC CODE 692, GREENBELT, MD 20771 USA. UNIV LEICESTER, DEPT PHYS, LEICESTER LE1 7RH, ENGLAND. DANISH METEOROL INST, DK-2100 COPENHAGEN, DENMARK. UCW, DEPT PHYS, ABERYSTWYTH SY23 3BZ, DYFED, WALES. LANL, LOS ALAMOS, NM 87545 USA. TECH UNIV BRAUNSCHWEIG, W-3300 BRAUNSCHWEIG, GERMANY. UNIV YORK, DEPT PHYS, YORK YO1 5DD, N YORKSHIRE, ENGLAND. BRITISH ANTARCTIC SURVEY, CAMBRIDGE CB3 0ET, ENGLAND. RP MORELLI, JP (reprint author), UNIV LONDON IMPERIAL COLL SCI TECHNOL & MED, BLACKETT LAB, LONDON SW7 2BZ, ENGLAND. RI Yeoman, Timothy/L-9105-2014 OI Yeoman, Timothy/0000-0002-8434-4825 NR 7 TC 3 Z9 3 U1 0 U2 0 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0273-1177 J9 ADV SPACE RES-SERIES JI Adv. Space Res. PD APR PY 1993 VL 13 IS 4 BP 135 EP 138 PG 4 WC Astronomy & Astrophysics; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences SC Astronomy & Astrophysics; Geology; Meteorology & Atmospheric Sciences GA KV092 UT WOS:A1993KV09200022 ER PT J AU MCPHERRON, RL ANGELOPOULOS, V BAKER, DN HONES, EW AF MCPHERRON, RL ANGELOPOULOS, V BAKER, DN HONES, EW TI IS THERE A NEAR-EARTH NEUTRAL LINE SO ADVANCES IN SPACE RESEARCH-SERIES LA English DT Article ID SUBSTORM EXPANSION PHASE; SOLAR-WIND PARAMETERS; SHEET BOUNDARY-LAYER; LOBE MAGNETIC-FIELD; PLASMA SHEET; MAGNETOSPHERIC SUBSTORMS; GEOMAGNETIC-ACTIVITY; MULTIPLE-SATELLITE; MAGNETOTAIL; DISRUPTION AB High correlations between southward turnings of the IMF, increases of open flux in the tail lobes, and magnetic activity confirm dayside magnetic reconnection plays a fundamental role in magnetospheric substorms. The absence of a time delay between expansion phase onset and the decrease in tail lobe flux suggest that nightside reconnection is involved in the expansion. At 20-30 R(e), the disappearance of the center of the plasma sheet and the appearance of tailward flows threaded with southward fields strongly suggest reconnection occurs earthward of this distance. Recent AMPTE/CCE and DMSP observations suggest that current disruption begins near synchronous orbit on closed field lines and expands tailward. Auroral images from the VIKING spacecraft support this. Reports of a lack of correlation between plasma and field changes at the ISEE spacecraft and onsets has led some researchers to reject the hypothesis that reconnection is the cause of the expansion. To counter these reports we present magnetic field and plasma data from substorms observed on an outbound pass by ISEE-2. We show that the tail field responds in the manner predicted by the near-earth neutral line (NENL) model, growing in strength and tilting earthward in the growth phase, and decreasing and tilting upward in the expansion phase. Near the earth the plasma sheet gradually thins in the growth phase while further away it suddenly thins at expansion onset. In the expansion phase the plasma sheet rapidly recovers close to the earth, but its recovery is delayed until the substorm recovery phase further from the earth. We explain many of the recent reports of disagreement between the NENL model and observations by a combination of factors. These include: Large changes in the location of a spacecraft relative to the neutral sheet as the size of the magnetosphere changes with dynamic pressure, or as the central meridian and latitude of substorm onset change due to inherent variability, Differences between the outbound and inbound portions of the ISEE orbit; Change in shape of successive orbits in GSM coordinates. Most important is multiple substorm onsets. Successive intensifications cause quite different effects at a spacecraft as the disturbance moves relative to the spacecraft. We conclude that rather than one x-line, there are probably multiple, localized pairs of x- and o-type lines formed in the near-earth plasma sheet during the substorm expansion. C1 NASA, GODDARD SPACE FLIGHT CTR, EXTRATERR PHYS LAB, GREENBELT, MD 20771 USA. LOS ALAMOS NATL LAB, LOS ALAMOS, NM 87545 USA. RP MCPHERRON, RL (reprint author), UNIV CALIF LOS ANGELES, INST GEOPHYS & PLANETARY PHYS, LOS ANGELES, CA 90024 USA. NR 43 TC 3 Z9 3 U1 0 U2 1 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0273-1177 J9 ADV SPACE RES-SERIES JI Adv. Space Res. PD APR PY 1993 VL 13 IS 4 BP 173 EP 186 PG 14 WC Astronomy & Astrophysics; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences SC Astronomy & Astrophysics; Geology; Meteorology & Atmospheric Sciences GA KV092 UT WOS:A1993KV09200028 ER PT J AU REEVES, GD AF REEVES, GD TI MULTIPLE SUBSTORM INJECTIONS AND THE NEW SUBSTORM PARADIGM - INTERPRETATION OF THE CDAW-7 SUBSTORM SO ADVANCES IN SPACE RESEARCH-SERIES LA English DT Article ID PLASMA SHEET; MAGNETOTAIL AB In the near-Earth neutral line model, the substorm is triggered by reconnection in the magnetotail and its effects radiate from there. In recent years new observations have suggested a new paradigm for substorms in which there are two coupled acceleration regions. In the current sheet disruption model the substorm is thought to begin in an acceleration region at the inner edge of the plasma sheet (5-10 Re) and to propagate down tail where it may trigger reconnection in the mid-tail (typically > 25 Re). We examine the CDAW 7 substorm in the context of this new substorm paradigm, with emphasis on the role of the substorm injection. RP REEVES, GD (reprint author), LOS ALAMOS NATL LAB, SPACE SCI & TECHNOL GRP, LOS ALAMOS, NM 87545 USA. OI Reeves, Geoffrey/0000-0002-7985-8098 NR 14 TC 2 Z9 2 U1 0 U2 0 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0273-1177 J9 ADV SPACE RES-SERIES JI Adv. Space Res. PD APR PY 1993 VL 13 IS 4 BP 213 EP 216 PG 4 WC Astronomy & Astrophysics; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences SC Astronomy & Astrophysics; Geology; Meteorology & Atmospheric Sciences GA KV092 UT WOS:A1993KV09200032 ER PT J AU BIRN, J HESSE, M AF BIRN, J HESSE, M TI PARTICLE-ACCELERATION IN A MHD SIMULATION OF MAGNETOTAIL DYNAMICS SO ADVANCES IN SPACE RESEARCH-SERIES LA English DT Article ID RECONNECTION AB The acceleration of protons in a dynamically evolving magnetotail is investigated on the basis of a three-dimensional resistive MHD simulation and the tracing of particles in the fields obtained from that simulation. The MHD simulation, representing plasmoid formation and ejection through a near-Earth reconnection process, generates cross-tail electric fields of up to about 4-mV/m, which lead to integrated potential differences across the tail of up to 200-kV. The large spatial extent of the increased electric field, which is largely associated with the plasma motion, together with the finite cross-tail extent suggest that acceleration might take place over a wide range of locations in x. This is confirmed by the particle tracing. An investigation of energized particles in the near-Earth region shows that these particles occupy a significant portion of the closed field line region inside of, but for moderate energies of tens of keV, not directly adjacent to, the separatrix. C1 NASA, GODDARD SPACE FLIGHT CTR, ELECTRODYNAM BRANCH, GREENBELT, MD 20771 USA. RP BIRN, J (reprint author), LOS ALAMOS NATL LAB, MS D438, LOS ALAMOS, NM 87545 USA. RI Hesse, Michael/D-2031-2012 NR 7 TC 1 Z9 1 U1 0 U2 0 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0273-1177 J9 ADV SPACE RES-SERIES JI Adv. Space Res. PD APR PY 1993 VL 13 IS 4 BP 245 EP 248 PG 4 WC Astronomy & Astrophysics; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences SC Astronomy & Astrophysics; Geology; Meteorology & Atmospheric Sciences GA KV092 UT WOS:A1993KV09200037 ER PT J AU HESSE, M BIRN, J AF HESSE, M BIRN, J TI PARALLEL ELECTRIC-FIELDS AS ACCELERATION MECHANISMS IN 3-DIMENSIONAL MAGNETIC RECONNECTION SO ADVANCES IN SPACE RESEARCH-SERIES LA English DT Article ID LINE AB An extension to the theory of General Magnetic Reconnection (GMR) is presented. In particular, a new analytical relation between the rate of change of newly connected magnetic flux and the maximum possible value of the parallel component of the electric field integrated along the magnetic field will be derived. Estimates of the maximum value based on three-dimensional MHD simulations will be presented also. C1 LOS ALAMOS NATL LAB, LOS ALAMOS, NM 87544 USA. RP NASA, GODDARD SPACE FLIGHT CTR, CODE 696, GREENBELT, MD 20771 USA. RI Hesse, Michael/D-2031-2012 NR 12 TC 2 Z9 2 U1 0 U2 0 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0273-1177 J9 ADV SPACE RES-SERIES JI Adv. Space Res. PD APR PY 1993 VL 13 IS 4 BP 249 EP 252 PG 4 WC Astronomy & Astrophysics; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences SC Astronomy & Astrophysics; Geology; Meteorology & Atmospheric Sciences GA KV092 UT WOS:A1993KV09200038 ER PT J AU SHEPPARD, LM BARKS, R AF SHEPPARD, LM BARKS, R TI THE BUSINESS OF TECHNOLOGY - VALUING CERAMIC TECHNOLOGY AS AN ASSET SO AMERICAN CERAMIC SOCIETY BULLETIN LA English DT Editorial Material RP SHEPPARD, LM (reprint author), LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545, USA. NR 0 TC 1 Z9 1 U1 0 U2 0 PU AMER CERAMIC SOC PI WESTERVILLE PA 735 CERAMIC PLACE, PO BOX 6136, WESTERVILLE, OH 43081-6136 SN 0002-7812 J9 AM CERAM SOC BULL JI Am. Ceram. Soc. Bull. PD APR PY 1993 VL 72 IS 4 BP 89 EP 92 PG 4 WC Materials Science, Ceramics SC Materials Science GA LE273 UT WOS:A1993LE27300013 ER PT J AU WINSLOW, SG AF WINSLOW, SG TI DEVELOPMENT OF A COST-EFFECTIVE - SILICON-NITRIDE POWDER SO AMERICAN CERAMIC SOCIETY BULLETIN LA English DT Article RP WINSLOW, SG (reprint author), OAK RIDGE NATL LAB,DIV MET & CERAM,OAK RIDGE,TN 37831, USA. NR 10 TC 6 Z9 6 U1 0 U2 0 PU AMER CERAMIC SOC PI WESTERVILLE PA 735 CERAMIC PLACE, PO BOX 6136, WESTERVILLE, OH 43081-6136 SN 0002-7812 J9 AM CERAM SOC BULL JI Am. Ceram. Soc. Bull. PD APR PY 1993 VL 72 IS 4 BP 99 EP 103 PG 5 WC Materials Science, Ceramics SC Materials Science GA LE273 UT WOS:A1993LE27300015 ER PT J AU ANDERSON, LE AF ANDERSON, LE TI BIOLOGICAL EFFECTS OF EXTREMELY LOW-FREQUENCY ELECTROMAGNETIC-FIELDS - INVIVO STUDIES SO AMERICAN INDUSTRIAL HYGIENE ASSOCIATION JOURNAL LA English DT Article; Proceedings Paper CT AMERICAN INDUSTRIAL HYGIENE CONF AND EXPOSITION ON ELECTRIC AND MAGNETIC FIELDS : WHAT DO WE KNOW ? CY MAY 18-24, 1991 CL SALT LAKE CITY, UT ID 60-HZ ELECTRIC-FIELDS; TOXICITY FOLLOWING EXPOSURE; RAT PINEAL-GLAND; MAGNETIC-FIELDS; MICE; WEAK; STIMULATION; GENERATIONS; SUPPRESSION; BEHAVIOR AB This paper discusses the biological effects of exposure to extremely low frequency electromagnetic fields observed in animal studies. Three areas of investigation are reported: (1) studies on the nervous system, including behavior and neuroendocrine function; (2) experiments on cancer development in animals; and (3) measurements of currents and electric fields induced in animal models by exposure to external magnetic fields. An attempt is made to evaluate experimental results and interpret them with respect to potential health implications. RP ANDERSON, LE (reprint author), PACIFIC NW LAB, MS-K4-28, POB 999, RICHLAND, WA 99352 USA. NR 116 TC 39 Z9 40 U1 1 U2 1 PU AMER INDUSTRIAL HYGIENE ASSOC PI FAIRFAX PA 2700 PROSPERITY AVE #250, FAIRFAX, VA 22031-4307 SN 0002-8894 J9 AM IND HYG ASSOC J JI Am. Ind. Hyg. Assoc. J. PD APR PY 1993 VL 54 IS 4 BP 186 EP 196 DI 10.1202/0002-8894(1993)054<0186:BEOELE>2.0.CO;2 PG 11 WC Environmental Sciences; Public, Environmental & Occupational Health SC Environmental Sciences & Ecology; Public, Environmental & Occupational Health GA KV707 UT WOS:A1993KV70700011 PM 8480634 ER PT J AU LARAMORE, GE KRALL, JM THOMAS, FJ RUSSELL, KJ MAOR, MH HENDRICKSON, FR MARTZ, KL GRIFFIN, TW DAVIS, LW AF LARAMORE, GE KRALL, JM THOMAS, FJ RUSSELL, KJ MAOR, MH HENDRICKSON, FR MARTZ, KL GRIFFIN, TW DAVIS, LW TI FAST-NEUTRON RADIOTHERAPY FOR LOCALLY ADVANCED PROSTATE-CANCER - FINAL REPORT OF A RADIATION-THERAPY ONCOLOGY GROUP RANDOMIZED CLINICAL-TRIAL SO AMERICAN JOURNAL OF CLINICAL ONCOLOGY-CANCER CLINICAL TRIALS LA English DT Article DE NEUTRON RADIOTHERAPY; PROSTATE CANCER ID EXTERNAL-BEAM RADIATION; STAGE-C ADENOCARCINOMA; FOLLOW-UP; BIOPSY; IRRADIATION AB Between June 1977 and April 1983 the Radiation Therapy Oncology Group (RTOG) sponsored a Phase III randomized trial investigating the use of fast neutron radiotherapy for patients with locally advanced (Stages C and D1) adenocarcinoma of the prostate gland. Patients were randomized to receive either conventional photon radiation or fast neutron radiation used in a mixed-beam (neutron/photon) treatment schedule. A total of 91 analyzable patients were entered into the study, and the two patient groups were balanced with respect to the major prognostic variables. Actuarial curves are presented for local/regional control and ''overall'' survival. Ten-year results for clinically assessed local control are 70% for the mixed-beam group versus 58% for the photon group (p = 0.03) and for survival are 46% for the mixed-beam group versus 29% for the photon group (p = 0.04). This study suggests that a regional method of treatment can influence both local tumor control and survival in patients with locally advanced adenocarcinoma of the prostate and. C1 AMER COLL RADIOL,STAT UNIT,PHILADELPHIA,PA. MD ANDERSON HOSP,DEPT RADIAT ONCOL,HOUSTON,TX. FERMILAB NATL ACCELERATOR LAB,MIDW INST NEUTRON THERAPY,BATAVIA,IL 60510. YESHIVA UNIV ALBERT EINSTEIN COLL MED,DEPT RADIAT ONCOL,BRONX,NY 10461. UNIV HOSP CLEVELAND,CLEVELAND,OH 44106. RP LARAMORE, GE (reprint author), UNIV WASHINGTON,MED CTR,DEPT RADIAT ONCOL,RC-08,SEATTLE,WA 98195, USA. FU NCI NIH HHS [CA-17465, CA-23113, CA-12441] NR 17 TC 78 Z9 78 U1 2 U2 3 PU LIPPINCOTT-RAVEN PUBL PI PHILADELPHIA PA 227 EAST WASHINGTON SQ, PHILADELPHIA, PA 19106 SN 0277-3732 J9 AM J CLIN ONCOL-CANC JI Am. J. Clin. Oncol.-Cancer Clin. Trials PD APR PY 1993 VL 16 IS 2 BP 164 EP 167 DI 10.1097/00000421-199304000-00018 PG 4 WC Oncology SC Oncology GA KT616 UT WOS:A1993KT61600018 PM 8452112 ER PT J AU ROBBINS, WA SEGRAVES, R PINKEL, D WYROBEK, AJ AF ROBBINS, WA SEGRAVES, R PINKEL, D WYROBEK, AJ TI DETECTION OF ANEUPLOID HUMAN SPERM BY FLUORESCENCE INSITU HYBRIDIZATION - EVIDENCE FOR A DONOR DIFFERENCE IN FREQUENCY OF SPERM DISOMIC FOR CHROMOSOMES-I AND CHROMOSOMES-Y SO AMERICAN JOURNAL OF HUMAN GENETICS LA English DT Article ID HUMAN-SPERMATOZOA; CYTOGENETIC ANALYSIS; DNA; TRANSLOCATION; NUCLEI; NONDISJUNCTION; ABNORMALITIES; PROBES AB Fluorescence in situ hybridization with repetitive-sequence DNA probes was used to detect human sperm disomic for chromosomes 1 and Y in three healthy men. Data on these same men had been obtained previously, using the human-sperm/hamster-egg cytogenetic technique, providing a cytogenetic reference for validating sperm hybridization measurements. Air-dried smears were prepared from semen samples and treated with DTT and lithium diiodosalicylate to expand sperm chromatin. Hybridization with fluorescently tagged DNA probes for chromosomes 1 (pUC177) or Y (pY3.4) yielded average frequencies of sperm with two fluorescent domains of 14.2+/-2.4/10,000 and 5.6+/-1.6/10,000 sperm, respectively. These frequencies did not differ statistically from frequencies of hyperploidy observed for these chromosomes with the hamster technique. In addition, frequencies of disomic sperm from one donor were elevated approximately 2.5-fold above those of other donors, for both chromosomes 1 (P = .045) and Y (P = .01), consistent with a trend found with the hamster technique. We conclude that fluorescence in situ hybridization to sperm chromosomes provides a valid and promising measure of the frequency of disomic human sperm. C1 LAWRENCE LIVERMORE NATL LAB,BIOL & BIOTECHNOL RES PROGRAM,L-452,7000 E AVE,LIVERMORE,CA 94550. UNIV CALIF BERKELEY,SCH PUBL HLTH,BERKELEY,CA 94720. UNIV CALIF SAN FRANCISCO,DEPT LAB MED,SAN FRANCISCO,CA 94143. NR 42 TC 142 Z9 147 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 S WOODLAWN AVE, CHICAGO, IL 60637 SN 0002-9297 J9 AM J HUM GENET JI Am. J. Hum. Genet. PD APR PY 1993 VL 52 IS 4 BP 799 EP 807 PG 9 WC Genetics & Heredity SC Genetics & Heredity GA KY059 UT WOS:A1993KY05900021 PM 8460647 ER PT J AU CHAIT, A BRAZG, RL TRIBBLE, DL KRAUSS, RM AF CHAIT, A BRAZG, RL TRIBBLE, DL KRAUSS, RM TI SUSCEPTIBILITY OF SMALL, DENSE, LOW-DENSITY LIPOPROTEINS TO OXIDATIVE MODIFICATION IN SUBJECTS WITH THE ATHEROGENIC LIPOPROTEIN PHENOTYPE, PATTERN-B SO AMERICAN JOURNAL OF MEDICINE LA English DT Article ID HUMAN ENDOTHELIAL-CELLS; ATHEROSCLEROTIC LESIONS; INVITRO OXIDATION; SUBCLASS PATTERNS; MACROPHAGES; EXPRESSION; LDL; RABBIT; RISK AB PURPOSE: To test whether low-density lipoprotein (LDL) from subjects with an atherogenic lipoprotein phenotype characterized by small, dense LDL (pattern B) demonstrates greater susceptibility to oxidative modification than LDL from subjects exhibiting primarily larger, more buoyant LDL particles (pattern A). PATIENTS AND METHODS: Measures of susceptibility to oxidative modification were compared in six density subfractions of LDL isolated from pattern A and pattern B subjects. Seven male and three female pattern A subjects and five male and two female pattern B subjects, classified on the basis of peak LDL particle size, were studied. Plasma lipid and lipoprotein levels, apolipoprotein B, mean LDL particle diameter, lag phase, and rate of oxidation after initiation of oxidation by copper sulfate were measured. RESULTS: The lag time, a measure of resistance to oxidative modification, was inversely related (p < 0.001) to LDL density in both groups of subjects, without an independent effect of phenotype. The fraction that had the major LDL peak had a shorter lag time (p < 0.05) in pattern B than in pattern A. Pattern B subjects also demonstrated an increased rate of oxidation (p < 0.005) in fraction 1, which includes remnants of triglyceride-rich lipoproteins. CONCLUSIONS: The increased atherogenic risk associated with the pattern B phenotype may result in part from increased concentrations of lipoprotein subpopulations that are relatively susceptible to oxidative modification. C1 UNIV CALIF BERKELEY,DONNER LAB,BERKELEY,CA 94720. LAWRENCE BERKELEY LAB,BERKELEY,CA 94720. STANFORD UNIV,CTR RES & DIS PREVENT,STANFORD,CA 94305. RP CHAIT, A (reprint author), UNIV WASHINGTON,DEPT MED RG26,DIV METAB ENDOCRINOL & NUTR,SEATTLE,WA 98195, USA. FU NCRR NIH HHS [RR00037]; NHLBI NIH HHS [HL18574, HL30086] NR 35 TC 394 Z9 397 U1 0 U2 4 PU EXCERPTA MEDICA INC PI NEW YORK PA 245 WEST 17TH STREET, NEW YORK, NY 10011 SN 0002-9343 J9 AM J MED JI Am. J. Med. PD APR PY 1993 VL 94 IS 4 BP 350 EP 356 DI 10.1016/0002-9343(93)90144-E PG 7 WC Medicine, General & Internal SC General & Internal Medicine GA KX941 UT WOS:A1993KX94100002 PM 8475928 ER PT J AU CRAWFORD, FS AF CRAWFORD, FS TI RELATIVISTIC EQUIPARTITION VIA A MASSIVE DAMPED SLIDING PARTITION SO AMERICAN JOURNAL OF PHYSICS LA English DT Article ID CRAWFORD TECHNIQUE; ELEMENTARY AB A cylinder partitioned by a massive sliding slab undergoing nonrelativistic damped one-dimensional (1D) motion under bombardment from the left (i=1) and right (i=2) by particles having rest mass m(i), speed v(i), relativistic momentum (magnitude) p(i), and (let c=1) total energy E(i)=(p(i)2+m(i)2)1/2 is considered herein. The damped slab of mass M transforms the system from its initial p(i) distributions (i=1,2) to a state, first, of pressure (P) equilibrium with P1=P2, but temperature T1 not-equal T2, then, to P-T equilibrium with P1=P2 and T1=T2, given by the (1D) ''first moment'' equipartition relation (kappa is Boltzmann's constant), [q1]=[q2]=kappaT [Eq. (A1)], where q(i)=p(i) v(i)=E(i)v(i)2=p(i)2/E(i). In achieving first-moment equilibrium at a given kappaT the slab M can be taken sufficiently large, hence slab oscillation period tau sufficiently long (tau much greater than t(max) where t(max)=2L(i)/v(min) is the round trip period of the slowest particle) to give ''mechanical adiabatic invariance'' (MAI), hence conservation of mechanical ''action'' p(i)L(i) of each particle. This first-moment equilibrium is not yet ''thermal'' equilibrium, since the MAI process leaves the higher moments [q(i)2], [q(i)3], etc., with their original values, relative to [q(i)]. To achieve thermal equilibrium the slab damping is turned off and slab mass M is reduced, hence tau decreases, until tau much less than t(max), whereupon MAI becomes ''broken'' and we achieve complete thermal equilibrium, given by Eq. (A1) plus the appropriate higher moments. Using straightforward extension of the relativistic technique used by Menon and Agrawal to find the first-moment relation (A1) we find that all of the moments of q1 satisfy the recursion relation [q(i)n]=nkappaT[q(i)n-1]+(n-1)m(i)2kappaT[q(i)n-1/E(i)2], i=1 or 2, n=1, 2, 3, 4,... [Eq. (A2)]. C1 LAWRENCE BERKELEY LAB,BERKELEY,CA 94720. RP CRAWFORD, FS (reprint author), UNIV CALIF BERKELEY,DEPT PHYS,BERKELEY,CA 94720, USA. NR 8 TC 4 Z9 4 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 APR PY 1993 VL 61 IS 4 BP 317 EP 325 DI 10.1119/1.17435 PG 9 WC Education, Scientific Disciplines; Physics, Multidisciplinary SC Education & Educational Research; Physics GA KV051 UT WOS:A1993KV05100006 ER PT J AU SCOTT, DE AF SCOTT, DE TI TIMING OF REPRODUCTION OF PAEDOMORPHIC AND METAMORPHIC AMBYSTOMA TALPOIDEUM SO AMERICAN MIDLAND NATURALIST LA English DT Article ID LARVAL ANURANS; BODY SIZE; PEDOMORPHOSIS; DENSITY; SUCCESS; NOTOPHTHALMUS; SALAMANDERS; COMPETITION; PREDATION; OPACUM AB Facultative paedomorphosis in salamanders is a plastic trait that may represent an adaptation to fluctuating environmental conditions. I compared the timing of reproduction in paedomorphic and terrestrial-morph Ambystoma talpoideum at the same pond. Paedomorphic adults laid eggs approximately 6 wk earlier than terrestrial morphs. Early egg-laying and subsequent growth of hatchlings resulted in a significant size advantage for larvae from paedomorphic parents at the time that terrestrial-morph eggs hatched. These observations suggest that, under certain environmental conditions, facultative paedomorphosis is advantageous. RP SCOTT, DE (reprint author), SAVANNAH RIVER ECOL LAB,DRAWER E,AIKEN,SC 29802, USA. NR 36 TC 31 Z9 34 U1 0 U2 7 PU AMER MIDLAND NATURALIST PI NOTRE DAME PA UNIV NOTRE DAME, BOX 369, ROOM 295 GLSC, NOTRE DAME, IN 46556 SN 0003-0031 J9 AM MIDL NAT JI Am. Midl. Nat. PD APR PY 1993 VL 129 IS 2 BP 397 EP 402 DI 10.2307/2426520 PG 6 WC Biodiversity Conservation; Ecology SC Biodiversity & Conservation; Environmental Sciences & Ecology GA LA692 UT WOS:A1993LA69200020 ER PT J AU BASTACKY, J GOERKE, J LEE, CY YAGER, D KENAGA, L KOUSHAFAR, H HAYES, TL CHEN, Y CLEMENTS, JA AF BASTACKY, J GOERKE, J LEE, CY YAGER, D KENAGA, L KOUSHAFAR, H HAYES, TL CHEN, Y CLEMENTS, JA TI ALVEOLAR LINING LIQUID LAYER IS THIN AND CONTINUOUS - LOW-TEMPERATURE SCANNING ELECTRON-MICROSCOPY OF NORMAL RAT LUNG SO AMERICAN REVIEW OF RESPIRATORY DISEASE LA English DT Meeting Abstract C1 LAWRENCE BERKELEY LAB,BERKELEY,CA 94720. UNIV WISCONSIN,IMR,MADISON,WI 53706. UNIV CALIF SAN FRANCISCO,CARDIOVASC RES INST,SAN FRANCISCO,CA 94143. NR 1 TC 7 Z9 7 U1 0 U2 1 PU AMER LUNG ASSOC PI NEW YORK PA 1740 BROADWAY, NEW YORK, NY 10019 SN 0003-0805 J9 AM REV RESPIR DIS JI Am. Rev. Respir. Dis. PD APR PY 1993 VL 147 IS 4 SU S BP A148 EP A148 PG 1 WC Respiratory System SC Respiratory System GA LB149 UT WOS:A1993LB14900535 ER PT J AU FERIN, J OBERDORSTER, G SEBRING, RJ LEHNERT, BE AF FERIN, J OBERDORSTER, G SEBRING, RJ LEHNERT, BE TI IS THE BRONCHUS-ASSOCIATED-LYMPHATIC TISSUE INTERCONNECTING THE PULMONARY PARTICLE CLEARANCE PATHWAYS SO AMERICAN REVIEW OF RESPIRATORY DISEASE LA English DT Meeting Abstract C1 UNIV ROCHESTER,ROCHESTER,NY 14627. LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87544. NR 2 TC 0 Z9 0 U1 0 U2 0 PU AMER LUNG ASSOC PI NEW YORK PA 1740 BROADWAY, NEW YORK, NY 10019 SN 0003-0805 J9 AM REV RESPIR DIS JI Am. Rev. Respir. Dis. PD APR PY 1993 VL 147 IS 4 SU S BP A387 EP A387 PG 1 WC Respiratory System SC Respiratory System GA LB149 UT WOS:A1993LB14901464 ER PT J AU LEHNERT, BE ARCHULETA, D ELLIS, T SESSION, WS LEHNERT, NL STAVERT, DM GURLEY, LR AF LEHNERT, BE ARCHULETA, D ELLIS, T SESSION, WS LEHNERT, NL STAVERT, DM GURLEY, LR TI RELATIONSHIP BETWEEN THE HYPERPERMEABILITY RESPONSE TO NITROGEN-DIOXIDE AND INCREASES IN LAVAGEABLE INFLAMMATORY CELLS SO AMERICAN REVIEW OF RESPIRATORY DISEASE LA English DT Meeting Abstract C1 LOS ALAMOS NATL LAB,DIV LIFE SCI,LOS ALAMOS,NM 87545. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER LUNG ASSOC PI NEW YORK PA 1740 BROADWAY, NEW YORK, NY 10019 SN 0003-0805 J9 AM REV RESPIR DIS JI Am. Rev. Respir. Dis. PD APR PY 1993 VL 147 IS 4 SU S BP A386 EP A386 PG 1 WC Respiratory System SC Respiratory System GA LB149 UT WOS:A1993LB14901457 ER PT J AU LEHNERT, BE ARCHULETA, D STAVERT, DM AF LEHNERT, BE ARCHULETA, D STAVERT, DM TI VENTILATORY CHANGES DURING AND PULMONARY INJURIOUS RESPONSE FOLLOWING BRIEF, HIGH-CONCENTRATION EXPOSURES TO NITROGEN-DIOXIDE SO AMERICAN REVIEW OF RESPIRATORY DISEASE LA English DT Meeting Abstract C1 LOS ALAMOS NATL LAB,DIV LIFE SCI,LOS ALAMOS,NM 87545. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER LUNG ASSOC PI NEW YORK PA 1740 BROADWAY, NEW YORK, NY 10019 SN 0003-0805 J9 AM REV RESPIR DIS JI Am. Rev. Respir. Dis. PD APR PY 1993 VL 147 IS 4 SU S BP A382 EP A382 PG 1 WC Respiratory System SC Respiratory System GA LB149 UT WOS:A1993LB14901442 ER PT J AU LEHNERT, BE VALDEZ, YE LEHNERT, NM ENGLEN, MD AF LEHNERT, BE VALDEZ, YE LEHNERT, NM ENGLEN, MD TI STIMULATION OF ALVEOLAR MACROPHAGE PROLIFERATION BY LUNG FIBROBLASTS AND SPECIFIC CYTOKINES SO AMERICAN REVIEW OF RESPIRATORY DISEASE LA English DT Meeting Abstract C1 LOS ALAMOS NATL LAB,DIV LIFE SCI,LOS ALAMOS,NM 87545. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER LUNG ASSOC PI NEW YORK PA 1740 BROADWAY, NEW YORK, NY 10019 SN 0003-0805 J9 AM REV RESPIR DIS JI Am. Rev. Respir. Dis. PD APR PY 1993 VL 147 IS 4 SU S BP A276 EP A276 PG 1 WC Respiratory System SC Respiratory System GA LB149 UT WOS:A1993LB14901023 ER PT J AU SUSSKIND, H WEBER, DA LAU, HY PARK, TL ATKINS, HL FRANCESCHI, D WONG, CTC AF SUSSKIND, H WEBER, DA LAU, HY PARK, TL ATKINS, HL FRANCESCHI, D WONG, CTC TI TC-99M-DTPA LUNG CLEARANCE IN PATIENTS WITH LUNG AND BREAST-CARCINOMA UNDERGOING RADIATION-THERAPY SO AMERICAN REVIEW OF RESPIRATORY DISEASE LA English DT Meeting Abstract C1 BROOKHAVEN NATL LAB,UPTON,NY 11973. SUNY,STONY BROOK,NY 11794. NR 0 TC 3 Z9 3 U1 0 U2 0 PU AMER LUNG ASSOC PI NEW YORK PA 1740 BROADWAY, NEW YORK, NY 10019 SN 0003-0805 J9 AM REV RESPIR DIS JI Am. Rev. Respir. Dis. PD APR PY 1993 VL 147 IS 4 SU S BP A67 EP A67 PG 1 WC Respiratory System SC Respiratory System GA LB149 UT WOS:A1993LB14900220 ER PT J AU DOMANSKY, K JANATA, J JOSOWICZ, M PETELENZ, D AF DOMANSKY, K JANATA, J JOSOWICZ, M PETELENZ, D TI PRESENT STATE OF FABRICATION OF CHEMICALLY SENSITIVE FIELD-EFFECT TRANSISTORS SO ANALYST LA English DT Article DE MICROSENSOR FABRICATION; PASSIVATION; CHEMICALLY SENSITIVE FIELD EFFECT TRANSISTOR ENCAPSULATION; ION SELECTIVE FIELD EFFECT TRANSISTOR TESTING; MULTISENSOR ID SILICON-NITRIDE; DEPOSITION; HYDROGEN; FILMS; STRESS AB Fabrication of reliable chemically sensitive field effect transistors still poses significant technical difficulties. Problems related to integrity of the solid state part of the device, integrity of the final sensor package, definition of the sensitive areas in multisensors and casting of the selective membranes have been addressed. Several strategies, such as employing photosensitive polyimides and electrochemically formed encapsulation, were investigated in an attempt to eliminate procedures at the individual device level. Performing as many fabrication steps as possible at the wafer level leads to higher yields and reduces fabrication costs by introducing automated processes. Electrochemical testing procedures at different fabrication stages of chemically sensitive field effect transistors are also presented. C1 UNIV UTAH, HEDCO MICROFABRICAT FACIL, SALT LAKE CITY, UT 84112 USA. PACIFIC NW LAB, MOLEC SCI RES CTR, RICHLAND, WA 99352 USA. UNIV MUNICH, INST PHYS, W-8014 MUNICH, GERMANY. NR 26 TC 20 Z9 20 U1 1 U2 2 PU ROYAL SOC CHEMISTRY PI CAMBRIDGE PA THOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLAND SN 0003-2654 EI 1364-5528 J9 ANALYST JI Analyst PD APR PY 1993 VL 118 IS 4 BP 335 EP 340 DI 10.1039/an9931800335 PG 6 WC Chemistry, Analytical SC Chemistry GA KY806 UT WOS:A1993KY80600005 ER PT J AU LJUNG, BME MOORE, DH WALDMAN, FM CHEW, KL MAYALL, BH SMITH, HS AF LJUNG, BME MOORE, DH WALDMAN, FM CHEW, KL MAYALL, BH SMITH, HS TI EFFECTS OF SHORT-TERM CULTURE ON BENIGN AND MALIGNANT HUMAN BREAST EPITHELIUM ANALYZED BY IMAGE-ANALYSIS SO ANALYTICAL AND QUANTITATIVE CYTOLOGY AND HISTOLOGY LA English DT Article ID CELLS; GROWTH AB The ability to culture malignant breast cells is crucial to the success of many scientific studies. However, short-term cultures of breast cancers are composed predominantly of DNA diploid cells, leading to doubt regarding the presence of bonafide cancer cells in these cultures. Morphology by conventional light microscopy is not helpful since cultured benign cells take on features usually associated with malignancy. In this study we examined by image analysis both benign and malignant breast cancer cells before and after culture. Consistent changes in both benign and malignant cells were found following culturing. There also were consistent differences distinguishing the cultures derived from benign and malignant specimens. While the features used were not sufficiently powerful to identify individual cells or cultures as benign or malignant, our results strongly suggest that malignant breast cells do indeed row in short-term cultures. C1 UNIV CALIF SAN FRANCISCO,SCH MED,DEPT LAB MED,DIV MOLEC CYTOMETRY,SAN FRANCISCO,CA 94143. LAWRENCE LIVERMORE NATL LAB,DIV BIOL & BIOTECHNOL,LIVERMORE,CA 94550. PACIFIC PRESBYTERIAN MED CTR,GERALDINE BRUSH CANC RES CTR,SAN FRANCISCO,CA. RP LJUNG, BME (reprint author), UNIV CALIF SAN FRANCISCO,SCH MED,DEPT PATHOL,SAN FRANCISCO,CA 94143, USA. FU NCI NIH HHS [P01 CA44768] NR 18 TC 4 Z9 4 U1 0 U2 0 PU SCI PRINTERS & PUBL INC PI ST LOUIS PA P.O. DRAWER 12425 8342 OLIVE BLVD, ST LOUIS, MO 63132 SN 0884-6812 J9 ANAL QUANT CYTOL JI Anal. Quant. Cytol. Histol. PD APR PY 1993 VL 15 IS 2 BP 107 EP 114 PG 8 WC Cell Biology SC Cell Biology GA LA315 UT WOS:A1993LA31500006 PM 8318125 ER PT J AU CASTRO, A FAIRFIELD, FR SHERA, EB AF CASTRO, A FAIRFIELD, FR SHERA, EB TI FLUORESCENCE DETECTION AND SIZE MEASUREMENT OF SINGLE DNA-MOLECULES SO ANALYTICAL CHEMISTRY LA English DT Article ID POLYMERASE CHAIN-REACTION AB We have developed a technique for the detection and size discrimination of single DNA molecules in a hydrodynamically focused flowing solution. Double-stranded lambda DNA molecules at 3 X 10(-15) M were stained with the fluorescent dye TOTO-1 and were individually detected. The technique makes use of a frequency-doubled mode-locked Nd:YAG laser to repetitively excite the molecules as they traverse the tightly focused laser beam. The flowing sample solution was hydrodynamically focused down to a 20-mum-diameter stream by a rapidly flowing water sheath. The sheath flow technique is well suited for laser-induced fluorescence detection of small-volume, low-concentration samples. The emitted fluorescence photon burst originating from a single DNA molecule was detected with a microchannel plate photomultiplier based single-photon counter, which used time-gated electronics for Raman and Rayleigh scattering rejection. In addition, a mixture of lambda DNA and smaller single-cut fragments has been simultaneously detected and identified by size. The advantages over other techniques for the detection and size determination of DNA fragments are discussed. C1 LOS ALAMOS NATL LAB,BIOPHYS GRP,MAIL STOP D434,LOS ALAMOS,NM 87545. LOS ALAMOS NATL LAB,THEORET BIOL GRP,LOS ALAMOS,NM 87545. NR 13 TC 117 Z9 119 U1 0 U2 6 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0003-2700 J9 ANAL CHEM JI Anal. Chem. PD APR 1 PY 1993 VL 65 IS 7 BP 849 EP 852 DI 10.1021/ac00055a004 PG 4 WC Chemistry, Analytical SC Chemistry GA KV284 UT WOS:A1993KV28400005 ER PT J AU TAYLOR, JA YEUNG, EA AF TAYLOR, JA YEUNG, EA TI MULTIPLEXED FLUORESCENCE DETECTOR FOR CAPILLARY ELECTROPHORESIS USING AXIAL OPTICAL FIBER ILLUMINATION SO ANALYTICAL CHEMISTRY LA English DT Note ID ZONE ELECTROPHORESIS; GEL-ELECTROPHORESIS; SPECTROSCOPY; DEVICE C1 IOWA STATE UNIV SCI & TECHNOL,US DOE,AMES LAB,AMES,IA 50011. IOWA STATE UNIV SCI & TECHNOL,DEPT CHEM,AMES,IA 50011. NR 23 TC 71 Z9 72 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0003-2700 J9 ANAL CHEM JI Anal. Chem. PD APR 1 PY 1993 VL 65 IS 7 BP 956 EP 960 DI 10.1021/ac00055a021 PG 5 WC Chemistry, Analytical SC Chemistry GA KV284 UT WOS:A1993KV28400022 ER PT J AU HUGHES, RC RICCO, AJ BUTLER, MA PFEIFER, KB AF HUGHES, RC RICCO, AJ BUTLER, MA PFEIFER, KB TI THE DETECTION OF ORGANOPHOSPHONATES BY POLYMER-FILMS ON A SURFACE-ACOUSTIC-WAVE DEVICE AND A MICROMIRROR FIBEROPTIC SENSOR SO APPLIED BIOCHEMISTRY AND BIOTECHNOLOGY LA English DT Article; Proceedings Paper CT US / JAPAN WORKSHOP ON MICROFABRICATION AND BIOSENSORS CY JUL 21-24, 1992 CL ANCHORAGE, AK SP NATL SCI FDN DE ORGANOPHOSPHATES; SAW DEVICES; FIBEROPTIC MICROMIRRORS AB There is a need for sensitive detection of organophosphonates by inexpensive, portable instruments. Two kinds of chemical sensors, based on surface acoustic wave (SAW) devices and fiberoptic micromirrors, show promise for such sensing systems. Chemically sensitive coatings are required for detection, and data for thin films of the polymer polysiloxane are reported for both kinds of physical transducers. Both kinds of sensors are shown to be capable of detecting concentrations of diisopropylmethylphosphonate (DIMP) down to 1 ppm. RP HUGHES, RC (reprint author), SANDIA NATL LABS,DEPT MICROSENSOR 1315,ALBUQUERQUE,NM 87185, USA. RI Ricco, Antonio/A-5273-2010 NR 9 TC 4 Z9 4 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 APR-MAY PY 1993 VL 41 IS 1-2 BP 77 EP 85 DI 10.1007/BF02918534 PG 9 WC Biochemistry & Molecular Biology; Biotechnology & Applied Microbiology SC Biochemistry & Molecular Biology; Biotechnology & Applied Microbiology GA LL844 UT WOS:A1993LL84400015 ER PT J AU SAPPEY, AD FUNK, DJ AF SAPPEY, AD FUNK, DJ TI SIMULTANEOUS DETECTION OF ATOMIC AND MOLECULAR-HYDROGEN USING A TUNABLE ARF EXCIMER LASER SO APPLIED PHYSICS B-PHOTOPHYSICS AND LASER CHEMISTRY LA English DT Article ID STATE-SPECIFIC DETECTION; FLUORESCENCE DETECTION; 2-PHOTON EXCITATION; FLAMES; H-2; IONIZATION AB We report preliminary experiments which demonstrate the simultaneous detection of both atomic and molecular hydrogen using a single tunable ArF laser. The tunable ArF laser was modified to lase simultaneously at two wavelengths by the addition of a second grating to the oscillator stage as in earlier work by Ketterle et al. for KrF operation. To our knowledge, this is the first demonstration of dual-wavelength capability with a tunable ArF excimer. The H atom diagnostic utilized tunable ArF excimer laser output at 193.29 nm which was Raman shifted in D2 (first Stokes) to generate 205.14 nm radiation which then excited the H atom to its (3s, 3d) states via a two-photon transition. Fluorescence was detected at 656 nm on the (3s, 3d) --> 2p transition. The second wavelength from the tunable excimer was used to excite several rovibronic LIF transitions of hydrogen molecule via two-photon absorption on the E 1SIGMA(g)+ double line arrow pointing left X 1SIGMA(g)+(2, 0) band. Fluorescence occurs at 750 nm and 830 nm on the (E 1SIGMA(g)1 double-line arrow pointing right B 1SIGMA(u)+) transitions. RP SAPPEY, AD (reprint author), LOS ALAMOS NATL LAB,DIV CHEM & LASER SCI,LOS ALAMOS,NM 87545, USA. NR 25 TC 3 Z9 3 U1 0 U2 2 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 SN 0721-7269 J9 APPL PHYS B-PHOTO PD APR PY 1993 VL 56 IS 4 BP 229 EP 234 DI 10.1007/BF00348630 PG 6 WC Physics, Applied SC Physics GA KX796 UT WOS:A1993KX79600006 ER PT J AU THOMPSON, JL CARTWRIGHT, AR AF THOMPSON, JL CARTWRIGHT, AR TI THE HALF-LIFE OF EU-150 SO APPLIED RADIATION AND ISOTOPES LA English DT Article ID LIVES; RADIONUCLIDES AB We report the half-life of Eu-150 as 36.9 +/- 0.9 years. This value was determined by following the decay of a mass-separated source over an 18-year period using a NaI(Tl) scintillation counter. We confirmed the stability of the counting system by measurement of Eu-152, Eu-154 and Eu-155 half-lives during the same period. RP THOMPSON, JL (reprint author), LOS ALAMOS NATL LAB,DIV ISOTOPE & NUCL CHEM,MS J-514,LOS ALAMOS,NM 87545, USA. NR 13 TC 4 Z9 4 U1 0 U2 0 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 APR PY 1993 VL 44 IS 4 BP 707 EP 709 DI 10.1016/0969-8043(93)90136-X PG 3 WC Chemistry, Inorganic & Nuclear; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Chemistry; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA KU184 UT WOS:A1993KU18400011 ER PT J AU ESPINOSA, G GAMMAGE, RB AF ESPINOSA, G GAMMAGE, RB TI MEASUREMENT METHODOLOGY FOR INDOOR RADON USING PASSIVE TRACK DETECTORS SO APPLIED RADIATION AND ISOTOPES LA English DT Article ID ALPHA-EMITTING RADIONUCLIDES AB A passive radon monitoring methodology based on CR-39 polycarbonate, alpha trace detectors (ATDs), is described for use in radon research and routine indoor measurements in Mexico. The monitoring device consists of a small exposure cup that contains the CR-39 chip. Unexposed ATDs are given an etching pretreatment which reduces the subsequent background track density and improves reproducibility. After exposure is complete, the ATD is sequentially etched, chemically and then electrochemically, for easy visualization and counting of etched tracks. At a radon activity concentration of 70 Bq/m3 the accumulation rate is 10 tracks/cm2-day; an integration time of 28 days produces a signal-to-noise ratio of 10. The background over that time is 30 tracks/cm2. A simple calibration chamber is described. The data are intercompared with a calibrated dynamic detector system. Measurement of radon exposure inside dwellings gains added significance in Mexico City because of the increased potential for lung cancer caused by the combined effects of radon, ozone and extremely heavy, chemical air pollution. C1 OAK RIDGE NATL LAB, DIV HLTH & SAFETY RES, OAK RIDGE, TN 37831 USA. RP ESPINOSA, G (reprint author), Univ Nacl Autonoma Mexico, INST FIS, APDO POSTAL 20-364, 01000 MEXICO CITY, DF, MEXICO. NR 13 TC 24 Z9 24 U1 1 U2 3 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0969-8043 J9 APPL RADIAT ISOTOPES JI Appl. Radiat. Isot. PD APR PY 1993 VL 44 IS 4 BP 719 EP 723 DI 10.1016/0969-8043(93)90138-Z 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 KU184 UT WOS:A1993KU18400013 ER PT J AU GATLEY, SJ FERRIERI, RA FOWLER, JS MACGREGOR, RR WOLF, AP AF GATLEY, SJ FERRIERI, RA FOWLER, JS MACGREGOR, RR WOLF, AP TI RAPID RADIOCHEMICAL AND CHEMICAL-QUALITY CONTROL OF [C-11] PUTRESCINE SO APPLIED RADIATION AND ISOTOPES LA English DT Article ID BRAIN-TUMORS; PUTRESCINE AB A short (4.6 x 50 mm) cation exchange column was used in conjunction with conductivity and radioactivity detectors to determine the radiochemical purity ( > 99%) and specific radioactivity (0.5-1.0 Ci/mu mol) of [1-C-11]putrescine prepared via Michael addition of [C-11]cyanide to acrylonitrile. The absence of acrylonitrile, a rodent carcinogen, from the final preparation was verified at the 50 ng level capillary vapor-phase chromatography (VPC) using a nitrogen-phosphorus detector. Routine VPC analysis using a Poropak Q column and flame ionization detection showed that preparations contained no more than 1 mug of acrylonitrile. RP GATLEY, SJ (reprint author), BROOKHAVEN NATL LAB,DEPT CHEM,UPTON,NY 11973, USA. FU NINDS NIH HHS [NS 15638, NS 15380] NR 10 TC 1 Z9 1 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 APR PY 1993 VL 44 IS 4 BP 765 EP 767 DI 10.1016/0969-8043(93)90146-2 PG 3 WC Chemistry, Inorganic & Nuclear; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Chemistry; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA KU184 UT WOS:A1993KU18400021 PM 8472030 ER PT J AU STEVENSON, CL VO-DINH, T AF STEVENSON, CL VO-DINH, T TI LASER-EXCITED SYNCHRONOUS LUMINESCENCE SPECTROSCOPY SO APPLIED SPECTROSCOPY LA English DT Article DE LASER SPECTROSCOPY; LUMINESCENCE; SYNCHRONOUS EXCITATION; POLYCYCLIC AROMATIC HYDROCARBONS ID FLUORESCENCE EMISSION-SPECTRA; SUPERSONIC JET; MOLECULAR FLUORESCENCE; AROMATIC-HYDROCARBONS; PARAMETER SELECTION; EXCITATION METHOD; SPECTROMETRY; DERIVATIVES; SCATTER; RAMAN AB The use of lasers as excitation sources for molecular luminescence often results in improvements in sensitivity and limits of detection (LODs). Synchronous luminescence (SL) spectroscopy, in which both excitation and emission wavelengths are scanned simultaneously, provides a convenient means to improve selectivity (often dramatically) in the analysis of multicomponent mixtures using room-temperature luminescence. We report here on the first use of a dye laser as an excitation source for SL at room temperature. The performance of the laser synchronous luminescence (LSL) system is described for the analysis of four polyaromatic compounds, for one of these-tetracene-the LOD was 680 zeptomoles (10(-21) mol) in the volume probed by the laser. In addition to impressive sensitivity and selectivity, the laser system used is quite small and can be considered as an attractive source for portable SL instruments designed for in-field screening of environmental samples. C1 OAK RIDGE NATL LAB, DIV HLTH & SAFETY RES, POB 2008, OAK RIDGE, TN 37831 USA. NR 40 TC 24 Z9 24 U1 1 U2 4 PU SOC APPLIED SPECTROSCOPY PI FREDERICK PA 5320 SPECTRUM DRIVE SUITE C, FREDERICK, MD 21703 USA SN 0003-7028 J9 APPL SPECTROSC JI Appl. Spectrosc. PD APR PY 1993 VL 47 IS 4 BP 430 EP 435 DI 10.1366/0003702934334967 PG 6 WC Instruments & Instrumentation; Spectroscopy SC Instruments & Instrumentation; Spectroscopy GA KZ612 UT WOS:A1993KZ61200008 ER PT J AU IIDA, Y YEUNG, ES AF IIDA, Y YEUNG, ES TI ACOUSTIC MONITORING OF CARBON-FILM FORMATION BY LASER-INDUCED CHEMICAL-VAPOR DEPOSITION SO APPLIED SPECTROSCOPY LA English DT Article DE INSTRUMENTATION, LUMINESCENCE; LASERS, NITROGEN; LUMINESCENCE; ANALYTICAL METHODS; LASER SPECTROSCOPY; SPECTROSCOPIC TECHNIQUES ID DIAMOND; BENZENE; PHOTODISSOCIATION; PHOTOLYSIS; PRESSURE AB Acoustic signals generated by the deposition Of carbon thin films were monitored in situ by a microphone. Photolysis of benzene or adamantane vapor in the presence of helium buffer gas of 5 to 100 Torr by an ArF excimer laser formed several kinds of carbon films (e.g., polymeric, amorphous, and graphitic films), depending on the optical configuration, the ambient pressure, the laser fluence, and the reagent pressure. Analysis of the acoustic signal offers some insight into the mechanism of the deposition processes, which include the graphitization of the deposited films and the role of energetic particles, such as vibrationally excited benzene, in the deposition of amorphous hydrogenated carbon film. Also, the acoustic signal clearly showed the presence of surface-related processes in the course of film deposition. C1 US DOE,AMES LAB,AMES,IA 50011. IOWA STATE UNIV SCI & TECHNOL,DEPT CHEM,AMES,IA 50011. NR 26 TC 4 Z9 4 U1 0 U2 1 PU SOC APPLIED SPECTROSCOPY PI FREDERICK PA PO BOX 1438, FREDERICK, MD 21701 SN 0003-7028 J9 APPL SPECTROSC JI Appl. Spectrosc. PD APR PY 1993 VL 47 IS 4 BP 523 EP 527 DI 10.1366/0003702934335010 PG 5 WC Instruments & Instrumentation; Spectroscopy SC Instruments & Instrumentation; Spectroscopy GA KZ612 UT WOS:A1993KZ61200021 ER PT J AU KELLOGG, GL AF KELLOGG, GL TI DIFFUSION BEHAVIOR OF PT ADATOMS AND CLUSTERS ON THE RH(100) SURFACE SO APPLIED SURFACE SCIENCE LA English DT Article; Proceedings Paper CT 39TH INTERNATIONAL FIELD EMISSION SYMP CY AUG 14, 1992 CL DALHOUSIE UNIV, HALIFAX, CANADA SP INT FIELD EMISS SOC HO DALHOUSIE UNIV ID ATOM-METHOD CALCULATIONS; SELF-DIFFUSION; PT(001); METAL; PAIR; NI; PD; ENERGIES; IR(100); DIMERS AB The diffusion of individual Pt adatoms and clusters of two to six Pt atoms on the (100) surface of Rh has been investigated by field ion microscopy. The diffusion mode for adatoms and clusters is determined to be conventional site-to-site hopping. Single adatoms and dimers migrate in the temperature range from 314 to 346 K with an activation energy of 0.92 eV. Trimers and tetramers, which are more stable as one-dimensional chains than two-dimensional islands, as well as pentamers, which are equally stable as chains and islands, all diffuse with the same activation energy of 1.03 eV. Hexamers, which are more stable as islands than chains, migrate with a somewhat higher activation energy of 1.16 eV. The relative stabilities of the chain versus island configurations indicate the presence of long-range adatom-adatom interactions in the clusters. The implications of the unexpected activation barriers for cluster diffusion are discussed. RP KELLOGG, GL (reprint author), SANDIA NATL LABS,ALBUQUERQUE,NM 87185, USA. NR 28 TC 34 Z9 34 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0169-4332 J9 APPL SURF SCI JI Appl. Surf. Sci. PD APR PY 1993 VL 67 IS 1-4 BP 134 EP 141 DI 10.1016/0169-4332(93)90305-U PG 8 WC Chemistry, Physical; Materials Science, Coatings & Films; Physics, Applied; Physics, Condensed Matter SC Chemistry; Materials Science; Physics GA KZ647 UT WOS:A1993KZ64700024 ER PT J AU MILLER, MK BURKE, MG AF MILLER, MK BURKE, MG TI AN APFIM AEM CHARACTERIZATION OF ALLOY-X750 SO APPLIED SURFACE SCIENCE LA English DT Article; Proceedings Paper CT 39TH INTERNATIONAL FIELD EMISSION SYMP CY AUG 14, 1992 CL DALHOUSIE UNIV, HALIFAX, CANADA SP INT FIELD EMISS SOC HO DALHOUSIE UNIV ID ATOM PROBE AB A combined atom probe field ion microscopy and analytical electron microscopy characterization of the microstructure of nickel-based superalloy Alloy X750 has been performed. These techniques revealed that 5-10 nm diameter gamma' precipitates formed during air-cooling to room temperature from the solution treatment temperature but were suppressed by a faster water quench. In addition, some fine (approximately 10-50 nm) discrete M23C6 carbides were formed at the grain boundaries during the air cool but not after the water quench. In the air-cooled material, both the gamma' precipitates and the M23C6 carbides coarsened upon subsequent aging at 718-degrees-C. On aging the water-quenched material at 718-degrees-C, a high density of 10-30 nm diameter gamma' precipitates was formed in the matrix and discontinuous precipitation of M23C6 carbides occurred at some grain boundaries. Atom probe analysis has revealed that the average composition of the gamma' precipitates in the 718-degrees-C aged conditions is not influenced by the cooling rate from the solution treatment temperature. The average Ti:Al:Nb ratios in the gamma' precipitates was approximately 8:4:1. C1 WESTINGHOUSE ELECT CORP,CTR SCI & TECHNOL,PITTSBURGH,PA 15235. RP MILLER, MK (reprint author), OAK RIDGE NATL LAB,DIV MET & CERAM,OAK RIDGE,TN 37831, USA. NR 6 TC 7 Z9 7 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0169-4332 J9 APPL SURF SCI JI Appl. Surf. Sci. PD APR PY 1993 VL 67 IS 1-4 BP 292 EP 298 DI 10.1016/0169-4332(93)90328-9 PG 7 WC Chemistry, Physical; Materials Science, Coatings & Films; Physics, Applied; Physics, Condensed Matter SC Chemistry; Materials Science; Physics GA KZ647 UT WOS:A1993KZ64700047 ER PT J AU JAYARAM, R MILLER, MK AF JAYARAM, R MILLER, MK TI AN ATOM-PROBE CHARACTERIZATION OF CARBON-DOPED NIAL SO APPLIED SURFACE SCIENCE LA English DT Article; Proceedings Paper CT 39TH INTERNATIONAL FIELD EMISSION SYMP CY AUG 14, 1992 CL DALHOUSIE UNIV, HALIFAX, CANADA SP INT FIELD EMISS SOC HO DALHOUSIE UNIV ID BORON AB The atom probe field ion microscope has been used to characterize stoichiometric NiAl doped with 300 ppm (0.1 at%) carbon. Field ion images of grain boundaries showed no decoration indicative of segregation. This observation was consistent with atom probe analyses which did not detect carbon at the grain boundaries. Matrix analyses revealed that only a small percentage (3-6%) of the carbon was in solid solution the remainder being in the form of ultrafine MC precipitates ranging from less than 1 nm to approximately 20 nm in diameter. Atom probe composition measurements revealed that the metallic component of the precipitates consisted of Ti, V, W and Cr which are present as trace impurities in the alloy. The enormous increase in the yield stress of carbon-doped over the undoped alloy is predominantly due to precipitation hardening from the carbide precipitates. RP JAYARAM, R (reprint author), OAK RIDGE NATL LAB,DIV MET & CERAM,OAK RIDGE,TN 37831, USA. NR 13 TC 8 Z9 8 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0169-4332 J9 APPL SURF SCI JI Appl. Surf. Sci. PD APR PY 1993 VL 67 IS 1-4 BP 311 EP 315 DI 10.1016/0169-4332(93)90331-5 PG 5 WC Chemistry, Physical; Materials Science, Coatings & Films; Physics, Applied; Physics, Condensed Matter SC Chemistry; Materials Science; Physics GA KZ647 UT WOS:A1993KZ64700050 ER PT J AU JAYARAM, R RUSSELL, KF MILLER, MK AF JAYARAM, R RUSSELL, KF MILLER, MK TI AN ATOM-PROBE STUDY OF THE SUBSTITUTIONAL BEHAVIOR OF BERYLLIUM IN NIAL SO APPLIED SURFACE SCIENCE LA English DT Article; Proceedings Paper CT 39TH INTERNATIONAL FIELD EMISSION SYMP CY AUG 14, 1992 CL DALHOUSIE UNIV, HALIFAX, CANADA SP INT FIELD EMISS SOC HO DALHOUSIE UNIV ID GRAIN-BOUNDARIES; NI3AL; BORON; DUCTILITY; COMPOUND AB Stoichiometric NiAl doped with 0.24 at% beryllium has been studied using atom probe field ion microscopy (APFIM). Composition measurements revealed that almost all the beryllium remained in solid solution in the matrix. Atom probe analysis of the (100) alternating pure nickel and pure aluminum planes determined the occupancy of beryllium to be almost exclusively at aluminum sites. A low number density of coarse MC precipitates, originating from trace impurities in the alloy, were found along the grain boundaries and within the grains. These coarse MC precipitates occurred in too low a number density to make any significant contribution to the observed increase in yield strength. The small increase in the yield strength that accompanied the beryllium addition to NiAl was from a weak solid solution strengthening mechanism from the substitutional beryllium atoms in the matrix. RP JAYARAM, R (reprint author), OAK RIDGE NATL LAB,DIV MET & CERAM,OAK RIDGE,TN 37831, USA. NR 14 TC 8 Z9 8 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0169-4332 J9 APPL SURF SCI JI Appl. Surf. Sci. PD APR PY 1993 VL 67 IS 1-4 BP 316 EP 320 DI 10.1016/0169-4332(93)90332-6 PG 5 WC Chemistry, Physical; Materials Science, Coatings & Films; Physics, Applied; Physics, Condensed Matter SC Chemistry; Materials Science; Physics GA KZ647 UT WOS:A1993KZ64700051 ER PT J AU MILLER, MK JAYARAM, R AF MILLER, MK JAYARAM, R TI CHARACTERIZATION OF A SIGMA-9 GRAIN-BOUNDARY IN FE-45-PERCENT-CR SO APPLIED SURFACE SCIENCE LA English DT Article; Proceedings Paper CT 39TH INTERNATIONAL FIELD EMISSION SYMP CY AUG 14, 1992 CL DALHOUSIE UNIV, HALIFAX, CANADA SP INT FIELD EMISS SOC HO DALHOUSIE UNIV AB An atom probe field ion microscopy characterization has been performed on a SIGMA9 grain boundary in an Fe-45at%Cr alloy that was aged for 500 h at 500-degrees-C. This boundary was decorated with a semicontinuous film of chromium nitride precipitates. The interior of the grains consisted of an ultrafine mixture of chromium-enriched alpha' and an iron-rich alpha phase that were produced by spinodal decomposition. The scale of this isotropic alpha-alpha' microstructure was found to be constant up to the grain boundary. A 5 to 10 nm thick chromium-depleted zone that was denuded in the alpha' phase was observed adjacent to the chromium nitride precipitates. RP MILLER, MK (reprint author), OAK RIDGE NATL LAB,DIV MET & CERAM,OAK RIDGE,TN 37831, USA. NR 9 TC 2 Z9 2 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0169-4332 J9 APPL SURF SCI JI Appl. Surf. Sci. PD APR PY 1993 VL 67 IS 1-4 BP 356 EP 360 DI 10.1016/0169-4332(93)90338-C PG 5 WC Chemistry, Physical; Materials Science, Coatings & Films; Physics, Applied; Physics, Condensed Matter SC Chemistry; Materials Science; Physics GA KZ647 UT WOS:A1993KZ64700057 ER PT J AU SETNA, RP HYDE, JM CEREZO, A SMITH, GDW CHISHOLM, MF AF SETNA, RP HYDE, JM CEREZO, A SMITH, GDW CHISHOLM, MF TI POSITION-SENSITIVE ATOM-PROBE STUDY OF THE DECOMPOSITION OF A CU-2.6AT-PERCENT-CO ALLOY SO APPLIED SURFACE SCIENCE LA English DT Article; Proceedings Paper CT 39TH INTERNATIONAL FIELD EMISSION SYMP CY AUG 14, 1992 CL DALHOUSIE UNIV, HALIFAX, CANADA SP INT FIELD EMISS SOC HO DALHOUSIE UNIV ID CRITICAL NUCLEUS SHAPES; FCC-FCC NUCLEATION; DILUTE CUCO ALLOYS; CO ALLOYS; ALPHA-PRECIPITATION; EARLY STAGE; CRYSTALLOGRAPHY; KINETICS; SANS; FIM AB In this paper we present a position sensitive atom probe study of phase decomposition in a Cu-2.6at%Co alloy, aged at 723 K for various times up to 24 hours. The composition and ageing temperature of the alloy were chosen such that the free energy barrier to decomposition was small. Statistical techniques are used to characterise the fine-scale microstructures present in the early stages of phase separation and three-dimensional atomic reconstructions of the alloys are presented. The experimental results from the position sensitive atom probe are compared with Monte Carlo simulations and with the sub-regular solution-classical nucleation model to gain a greater insight into the nature of the processes taking place in the early stages of phase decomposition. Results demonstrate a complex range of behaviour, from the development of enriched and partially diffuse regions of Co to the formation of Co-rich alpha precipitates. Monte Carlo simulations adequately mimic many of the features observed in the experimental data. C1 OAK RIDGE NATL LAB,DIV SOLID STATE,OAK RIDGE,TN 37831. RP SETNA, RP (reprint author), UNIV OXFORD,DEPT MAT,PARKS RD,OXFORD OX1 3PH,ENGLAND. NR 33 TC 16 Z9 16 U1 1 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0169-4332 J9 APPL SURF SCI JI Appl. Surf. Sci. PD APR PY 1993 VL 67 IS 1-4 BP 368 EP 379 DI 10.1016/0169-4332(93)90340-H PG 12 WC Chemistry, Physical; Materials Science, Coatings & Films; Physics, Applied; Physics, Condensed Matter SC Chemistry; Materials Science; Physics GA KZ647 UT WOS:A1993KZ64700059 ER PT J AU JAYARAM, R MILLER, MK AF JAYARAM, R MILLER, MK TI AN APFIM AEM INVESTIGATION OF PRECIPITATES IN MODEL VANADIUM ALLOYS SO APPLIED SURFACE SCIENCE LA English DT Article; Proceedings Paper CT 39TH INTERNATIONAL FIELD EMISSION SYMP CY AUG 14, 1992 CL DALHOUSIE UNIV, HALIFAX, CANADA SP INT FIELD EMISS SOC HO DALHOUSIE UNIV ID ATOM-PROBE; BASE ALLOYS AB The morphology and composition of MC precipitates in two model vanadium alloys were studied with a combination of atom probe field ion microscopy (APFlM) and analytical electron microscopy (AEM). Atom probe analysis of an alloy with a bulk composition of V-2.07at%Ti-0.33at%C-0.01at%N-0.07at%O revealed thin disk-shaped titanium carbonitride precipitates in large number densities in the matrix. In addition to the disk-shaped titanium oxycarbonitrides, a second type of precipitates with cuboidal faceted morphology was detected in another alloy of bulk composition V-2.12at%Ti-0.4at%Zr-0.37at%C-0.02at%N-0.1at%O. AEM analysis of the low number density cuboidal MC precipitates revealed that the metallic content was 63.5 at% Zr with the balance being Ti and V. Both types of precipitates had face-centered cubic structures with lattice parameters intermediate between those of TiC and TiN and ZrC and ZrN, respectively. The observation of additional wing-like attachments to the facets of the Zr-rich cuboid precipitates has implications for creep resistance in a wider class of alloys. RP JAYARAM, R (reprint author), OAK RIDGE NATL LAB,DIV MET & CERAM,OAK RIDGE,TN 37831, USA. NR 13 TC 0 Z9 0 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0169-4332 J9 APPL SURF SCI JI Appl. Surf. Sci. PD APR PY 1993 VL 67 IS 1-4 BP 380 EP 385 DI 10.1016/0169-4332(93)90341-8 PG 6 WC Chemistry, Physical; Materials Science, Coatings & Films; Physics, Applied; Physics, Condensed Matter SC Chemistry; Materials Science; Physics GA KZ647 UT WOS:A1993KZ64700060 ER PT J AU BOWMAN, KO MILLER, MK SHENTON, LR AF BOWMAN, KO MILLER, MK SHENTON, LR TI THE USE OF MOMENT ESTIMATORS TO DETERMINE THE PARAMETERS OF CONCENTRATION FLUCTUATIONS IN RANDOM AREA ATOM-PROBE ANALYSES SO APPLIED SURFACE SCIENCE LA English DT Article; Proceedings Paper CT 39TH INTERNATIONAL FIELD EMISSION SYMP CY AUG 14, 1992 CL DALHOUSIE UNIV, HALIFAX, CANADA SP INT FIELD EMISS SOC HO DALHOUSIE UNIV AB A method based on moment estimators for the estimation of the extent of concentration fluctuations in atom probe random area analyses is described. The extent of the concentration fluctuations determined from this moment estimators method and from the maximum likelihood P(a) method showed excellent agreement for a series of random area analyses obtained from a spinodally decomposed Fe-45%Cr alloy that was aged at 500-degrees-C within the low temperature miscibility gap. C1 UNIV GEORGIA,UNIV COMP & NETWORKING SERV,ATHENS,GA 30602. OAK RIDGE NATL LAB,DIV MET & CERAM,OAK RIDGE,TN 37831. RP BOWMAN, KO (reprint author), OAK RIDGE NATL LAB,DIV ENGN PHYS & MATH,OAK RIDGE,TN 37831, USA. NR 11 TC 1 Z9 1 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0169-4332 J9 APPL SURF SCI JI Appl. Surf. Sci. PD APR PY 1993 VL 67 IS 1-4 BP 424 EP 428 DI 10.1016/0169-4332(93)90348-F PG 5 WC Chemistry, Physical; Materials Science, Coatings & Films; Physics, Applied; Physics, Condensed Matter SC Chemistry; Materials Science; Physics GA KZ647 UT WOS:A1993KZ64700067 ER PT J AU MILLER, MK BOWMAN, KO CEREZO, A HYDE, JM AF MILLER, MK BOWMAN, KO CEREZO, A HYDE, JM TI COMPARISON OF MODELS FOR DECONVOLUTING THE COMPOSITIONS OF COEXISTING PHASES SO APPLIED SURFACE SCIENCE LA English DT Article; Proceedings Paper CT 39TH INTERNATIONAL FIELD EMISSION SYMP CY AUG 14, 1992 CL DALHOUSIE UNIV, HALIFAX, CANADA SP INT FIELD EMISS SOC HO DALHOUSIE UNIV AB A comparison has been performed on the best fits between frequency distributions obtained from atom probe random area analyses and probability densities obtained from (1) the sinusoidal or P(a) model, (2) a square wave model, and (3) mixtures of two Gaussian distributions. The materials used for this comparison were Fe-24%Cr and Fe-45%Cr alloys aged between 4 and 500 h at 500-degrees-C to produce a mixture of an iron-rich alpha phase and a chromium-enriched alpha' phase. The Gaussian models generally provided satisfactory fits for both 24 and 45% Cr materials and all aging conditions. The P(a) model was found to be unsuitable for the 24% Cr alloy at longer aging times. C1 OAK RIDGE NATL LAB,DIV ENGN PHYS & MATH,OAK RIDGE,TN 37831. UNIV OXFORD,DEPT MAT,OXFORD OX1 3PH,ENGLAND. RP MILLER, MK (reprint author), OAK RIDGE NATL LAB,DIV MET & CERAM,OAK RIDGE,TN 37831, USA. NR 9 TC 5 Z9 5 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0169-4332 J9 APPL SURF SCI JI Appl. Surf. Sci. PD APR PY 1993 VL 67 IS 1-4 BP 429 EP 435 DI 10.1016/0169-4332(93)90349-G PG 7 WC Chemistry, Physical; Materials Science, Coatings & Films; Physics, Applied; Physics, Condensed Matter SC Chemistry; Materials Science; Physics GA KZ647 UT WOS:A1993KZ64700068 ER PT J AU THOMAS, D SCHRAMM, DN OLIVE, KA FIELDS, BD AF THOMAS, D SCHRAMM, DN OLIVE, KA FIELDS, BD TI PRIMORDIAL NUCLEOSYNTHESIS AND THE ABUNDANCES OF BERYLLIUM AND BORON SO ASTROPHYSICAL JOURNAL LA English DT Article DE NUCLEAR REACTIONS; NUCLEOSYNTHESIS; ABUNDANCES ID ENERGY-LEVELS; LIGHT-NUCLEI; HEAVY-ELEMENTS; REACTION-RATES; HALO-STARS; BE-9; LITHIUM; NUMBER AB The recently attained ability to make measurements of Be and B as well as to put constraints on Li-6 abundances in metal-poor stars has led to a detailed reexamination of big bang nucleosynthesis in the A greater than or similar to 6 regime. The nuclear reaction network has been significantly expanded, with many new rates added. It is demonstrated that although a number of A > 7 reaction rates are poorly determined, even with extreme values chosen, the standard homogeneous model is unable to produce significant yields (Be/H and B/H < 10(-17) when A less-than-or-equal-to 7 abundances fit) above A = 7, and the 7 Li-7/Li-6 ratio always exceeds 500. We also preliminarily explore inhomogeneous models, such as those inspired by a first-order quark-hadron phase transition, where regions with high neutron/proton ratios can allow some leakage up to A > 7. However, models that fit the A less-than-or-equal-to 7 abundances still seem to have difficulty in obtaining significant A > 7 yields. C1 NASA,FERMILAB ASTROPHYS CTR,FNAL,BATAVIA,IL 60510. UNIV MINNESOTA,SCH PHYS & ASTRON,MINNEAPOLIS,MN 55455. RP THOMAS, D (reprint author), UNIV CHICAGO,CHICAGO,IL 60637, USA. NR 51 TC 83 Z9 83 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 APR 1 PY 1993 VL 406 IS 2 BP 569 EP 579 DI 10.1086/172469 PN 1 PG 11 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA KU607 UT WOS:A1993KU60700023 ER PT J AU BLANCO, A BUSSOLETTI, E COLANGELI, L FONTI, S MENNELLA, V STEPHENS, JR AF BLANCO, A BUSSOLETTI, E COLANGELI, L FONTI, S MENNELLA, V STEPHENS, JR TI THE ULTRAVIOLET-SPECTRUM OF ANNEALED HYDROGENATED AMORPHOUS-CARBON GRAINS SO ASTROPHYSICAL JOURNAL LA English DT Article DE DUST, EXTINCTION; LINE, IDENTIFICATION; MOLECULAR PROCESSES; ULTRAVIOLET, INTERSTELLAR ID INTERSTELLAR EXTINCTION; STARS; FILMS; DUST AB In a previous paper (Blanco et al. 1991) we experimentally showed how the optical properties of amorphous carbon particles are affected by the presence of hydrogen during their condensation. In the present work we report UV spectra of annealed grains produced in hydrogen-rich atmosphere. The laboratory results support the idea that the interstellar 2175 angstrom feature is due to the extinction produced by amorphous carbon grains dehydrogenated via UV irradiation. C1 OSSERV ASTRON CAPODIMONTE,I-80131 NAPLES,ITALY. UNIV NAPOLI,IST NAVACE,I-80133 NAPLES,ITALY. UNIV CASSINO,DIPARTIMENTO INGN,I-03043 CASSINO,ITALY. LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545. RP BLANCO, A (reprint author), UNIV LECCE,DEPT PHYS,CP 193,I-73100 LECCE,ITALY. NR 27 TC 19 Z9 19 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 APR 1 PY 1993 VL 406 IS 2 BP 739 EP 741 DI 10.1086/172485 PN 1 PG 3 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA KU607 UT WOS:A1993KU60700039 ER PT J AU DENNIS, RL MCHENRY, JN BARCHET, WR BINKOWSKI, FS BYUN, DW AF DENNIS, RL MCHENRY, JN BARCHET, WR BINKOWSKI, FS BYUN, DW TI CORRECTING RADM SULFATE UNDERPREDICTION - DISCOVERY AND CORRECTION OF MODEL ERRORS AND TESTING THE CORRECTIONS THROUGH COMPARISONS AGAINST FIELD DATA SO ATMOSPHERIC ENVIRONMENT PART A-GENERAL TOPICS LA English DT Article DE REGIONAL ACID DEPOSITION MODELING; RADM; REGIONAL AMBIENT SULFATE; NONPRECIPITATING CLOUDS AND REGIONAL SULFATE; REGIONAL MODEL EVALUATION; RADM EVALUATION; EULERIAN MODEL EVALUATION FIELD STUDY ID ACID DEPOSITION MODEL; PARAMETERIZATION; SULFUR; CLOUDS AB A serious underprediction of ambient sulfate (SO42-) by two comprehensive, Eulerian models of acid deposition, the Regional Acid Deposition Model (RADM) and the Acid Deposition and Oxidant Model(ADOM), was found in the National Acid Precipitation Assessment Program phase of the Eulerian Model Evaluation Field Study (EMEFS) model evaluation. Two hypotheses were proposed to explain the cause of the underprediction in RADM: insufficient SO42- production by nonprecipitating convective clouds and insufficient primary SO42- emissions. Modifications of the RADM cloud and scavenging module to simulate nonprecipitating cumulus clouds better are described in detail, Three contrasting pairs of tests using data from the EMEFS were applied to these hypotheses: source vs downwind regions, mid-summer vs late summer seasons and sunny-dry vs cloudy-wet synoptic types. The SO42- emissions hypothesis, tested by artificially boosting SO42- emissions, fared better than expected but was rejected because of its poor performance on the regional and seasonal contrast tests. The RADM nonprecipitating cumulus modification successfully captured the seasonal and the late summer synoptic contrasts but improvement is still needed for the regional and mid-summer synoptic contrasts. C1 COMP SCI CORP, DIV APPL TECHNOL, RES TRIANGLE PK, NC 27709 USA. PACIFIC NW LAB, DEPT ATMOSPHER SCI, RICHLAND, WA 99352 USA. RP NOAA, AIR RESOURCES LAB, DIV ATMOSPHER SCI MODELING, RES TRIANGLE PK, NC 27711 USA. NR 25 TC 41 Z9 41 U1 0 U2 2 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0004-6981 J9 ATMOS ENVIRON A-GEN PD APR PY 1993 VL 27 IS 6 BP 975 EP 997 DI 10.1016/0960-1686(93)90012-N PG 23 WC Environmental Sciences; Meteorology & Atmospheric Sciences SC Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences GA LC618 UT WOS:A1993LC61800012 ER PT J AU LONGMIRE, JL MALTBIE, M PAVELKA, RW SMITH, LM WITTE, SM RYDER, OA ELLSWORTH, DL BAKER, RJ AF LONGMIRE, JL MALTBIE, M PAVELKA, RW SMITH, LM WITTE, SM RYDER, OA ELLSWORTH, DL BAKER, RJ TI GENDER IDENTIFICATION IN BIRDS USING MICROSATELLITE DNA FINGERPRINT ANALYSIS SO AUK LA English DT Note C1 TEXAS TECH UNIV,DEPT BIOL SCI,LUBBOCK,TX 79409. TEXAS TECH UNIV,DEPT RANGE & WILDLIFE MANAGEMENT,LUBBOCK,TX 79409. ZOOL SOC SAN DIEGO,CTR REPROD ENDANGERED SPECIES,SAN DIEGO,CA 92112. TEXAS A&M UNIV SYST,DEPT WILDLIFE & FISHERIES SCI,COLL STN,TX 77843. RP LONGMIRE, JL (reprint author), LOS ALAMOS NATL LAB,DIV LIFE SCI,GENOM & STRUCT BIOL GRP,LOS ALAMOS,NM 87545, USA. NR 15 TC 29 Z9 29 U1 1 U2 5 PU AMER ORNITHOLOGISTS UNION PI LAWRENCE PA ORNITHOLOGICAL SOC NORTH AMER PO BOX 1897, LAWRENCE, KS 66044-8897 SN 0004-8038 J9 AUK JI AUK PD APR PY 1993 VL 110 IS 2 BP 378 EP 381 PG 4 WC Ornithology SC Zoology GA MC017 UT WOS:A1993MC01700021 ER PT J AU SAXTON, MJ AF SAXTON, MJ TI LATERAL DIFFUSION IN AN ARCHIPELAGO - DEPENDENCE ON TRACER SIZE SO BIOPHYSICAL JOURNAL LA English DT Article ID 2-PHASE PHOSPHATIDYLCHOLINE BILAYER; FLUID-PHASE CONNECTIVITY; TRANSLATIONAL DIFFUSION; BIOLOGICAL-MEMBRANES; LIMITED AGGREGATION; FRACTAL CLUSTERS; BROWNIAN-MOTION; LIPID BILAYERS; PERCOLATION; 2-COMPONENT AB In a pure fluid-phase lipid, the dependence of the lateral diffusion coefficient on the size of the diffusing particle may be obtained from the Saffman-Delbruck equation or the free-volume model. When diffusion is obstructed by immobile proteins or domains of gel-phase lipids, the obstacles yield an additional contribution to the size dependence. Here this contribution is examined using Monte Carlo calculations. For random point and hexagonal obstacles, the diffusion coefficient depends strongly on the size of the diffusing particle, but for fractal obstacles-cluster-cluster aggregates and multicenter diffusion-limited aggregates-the diffusion coefficient is independent of the size of the diffusing particle. The reason is that fractals have no characteristic length scale, so a tracer sees on average the same obstructions, regardless of its size. The fractal geometry of the excluded area for tracers of various sizes is examined. Percolation thresholds are evaluated for a variety of obstacles to determine how the threshold depends on tracer size and to compare the thresholds for compact and extended obstacles. C1 LAWRENCE BERKELEY LAB,CHEM BIODYNAM LAB,BERKELEY,CA 94720. RP SAXTON, MJ (reprint author), UNIV CALIF DAVIS,INST THEORET DYNAM,DAVIS,CA 95616, USA. FU NIGMS NIH HHS [GM-38133] NR 43 TC 94 Z9 95 U1 0 U2 4 PU BIOPHYSICAL SOCIETY PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814-3998 SN 0006-3495 J9 BIOPHYS J JI Biophys. J. PD APR PY 1993 VL 64 IS 4 BP 1053 EP 1062 PG 10 WC Biophysics SC Biophysics GA KY272 UT WOS:A1993KY27200010 PM 8494970 ER PT J AU MAXON, AB WHITE, KR VOHR, BR BEHRENS, TR AF MAXON, AB WHITE, KR VOHR, BR BEHRENS, TR TI USING TRANSIENT EVOKED OTOACOUSTIC EMISSIONS FOR NEONATAL HEARING SCREENING SO BRITISH JOURNAL OF AUDIOLOGY LA English DT Article; Proceedings Paper CT 3RD INTERNATIONAL SYMP ON COCHLEAR MECHANISMS AND OTOACOUSTIC EMISSIONS CY DEC 04-06, 1992 CL ROME, ITALY SP CTR RIC & STUDI AMPLIFON ID ACOUSTIC EMISSIONS; IDENTIFICATION C1 UTAH STATE UNIV,LOGAN,UT 84322. BROWN UNIV,PROGRAM MED,PROVIDENCE,RI 02912. US DOE,WASHINGTON,DC. RP MAXON, AB (reprint author), UNIV CONNECTICUT,850 BOLTON RD,STORRS,CT 06269, USA. FU PHS HHS [MCJ-495037] NR 18 TC 52 Z9 52 U1 1 U2 1 PU W B SAUNDERS CO LTD PI LONDON PA 24-28 OVAL RD, LONDON, ENGLAND NW1 7DX SN 0300-5364 J9 BRIT J AUDIOL JI Br. J. Audiol. PD APR PY 1993 VL 27 IS 2 BP 149 EP 153 DI 10.3109/03005369309077906 PG 5 WC Otorhinolaryngology SC Otorhinolaryngology GA MG222 UT WOS:A1993MG22200014 PM 8220282 ER PT J AU LEACH, RR DOWLA, FU VERGINO, ES AF LEACH, RR DOWLA, FU VERGINO, ES TI YIELD ESTIMATION USING BANDPASS-FILTERED SEISMOGRAMS - PRELIMINARY-RESULTS USING NEURAL NETWORKS WITH M(B)(PN), SHORT-TIME, LONG-TIME, AND CODA ENERGY MEASUREMENTS SO BULLETIN OF THE SEISMOLOGICAL SOCIETY OF AMERICA LA English DT Article AB A neural network has been developed to simultaneously use multiple seismic measurements, such as m(b)(Pn) and coda energy, for estimating yields of underground nuclear explosions. Yield estimation results based on a large number of Nevada Test Site events that were recorded at the broadband seismic stations at Elko, Kanab, Landers, and Mina indicate that different length windows (6,18, and 200 sec) of seismogram energy are as useful as the m(b)(Pn) measurement when the seismogram is filtered between 0.5 and 2 Hz. Detailed results of yield estimation trends as a function of signal frequency are also obtained. Yield estimation performance using long lapse time coda energy above 2 Hz is significantly limited by the signal-to-noise ratio (SNR). Performance of the neural network with both M(b)(Pn) and energy information as input does not significantly exceed the performance of a conventional linear regression analysis that is based only on m(b)(Pn). Properties of the coda signal as a function of frequency and SNR that might ultimately lead us to the application of a full seismogram with a neural network for accurate seismic yield estimation are discussed. RP LEACH, RR (reprint author), LAWRENCE LIVERMORE NATL LAB, 7000 EAST AVE L-208, LIVERMORE, CA 94550 USA. NR 18 TC 3 Z9 3 U1 0 U2 1 PU SEISMOLOGICAL SOC AMER PI ALBANY PA 400 EVELYN AVE, SUITE 201, ALBANY, CA 94706-1375 USA SN 0037-1106 EI 1943-3573 J9 B SEISMOL SOC AM JI Bull. Seismol. Soc. Amer. PD APR PY 1993 VL 83 IS 2 BP 488 EP 508 PG 21 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA KT736 UT WOS:A1993KT73600011 ER PT J AU MANGINO, SG ZANDT, G AMMON, CJ AF MANGINO, SG ZANDT, G AMMON, CJ TI THE RECEIVER STRUCTURE BENEATH MINA, NEVADA SO BULLETIN OF THE SEISMOLOGICAL SOCIETY OF AMERICA LA English DT Article ID TELESEISMIC P-WAVEFORMS; CRUSTAL STRUCTURE; SEISMIC REFRACTION; GREAT-BASIN; BODY-WAVES; LITHOSPHERE; WASHINGTON; INVERSION; RANGE AB Receiver functions obtained from broadband teleseismic P waveforms recorded at seismic station MNV, near Mina, Nevada, are inverted for the vertical shear-wave velocity structure southeast of the station. The time-domain inversion procedure for vertically heterogeneous and laterally homogeneous one-dimensional models includes smoothness constraints to minimize model roughness and a pseudo-Monte-Carlo approach to investigate the nonuniqueness of the solution models. We also report on the potential effects of scattering on a receiver function inversion for a one-dimensional velocity structure. MNV receiver functions sample the Walker Belt crust and upper mantle beneath the Soda Spring Valley and Pilot Mountains to the east and the Garfield Hills and Excelsior Mountains to the west of the station. The preferred southeast solution models show a smooth positive gradient in the mid- and lower crust with the top of the crust-mantle boundary at 34- to 36-km depth, reaching an upper-mantle P velocity of 7.8 to 7.9 km sec-1 between 38 and 40 km. These results suggest that the crust beneath MNV may be representative of a transition zone between typical Basin and Range province crust to the east and a thicker Sierran block to the west of the station. C1 USAF,DIV EARTH SCI,GEOPHYS LAB,BEDFORD,MA 01731. PENN STATE UNIV,DEPT GEOSCI,STATE COLL,PA 16802. LAWRENCE LIVERMORE NATL LAB,INST GEOPHYS & PLANETARY SCI,LIVERMORE,CA 94550. NR 32 TC 20 Z9 20 U1 2 U2 2 PU SEISMOLOGICAL SOC AMER PI EL CERRITO PA PLAZA PROFESSIONAL BLDG, SUITE 201, EL CERRITO, CA 94530 SN 0037-1106 J9 B SEISMOL SOC AM JI Bull. Seismol. Soc. Amer. PD APR PY 1993 VL 83 IS 2 BP 542 EP 560 PG 19 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA KT736 UT WOS:A1993KT73600014 ER PT J AU RODGERS, PW AF RODGERS, PW TI MAXIMIZING THE SIGNAL-TO-NOISE RATIO OF THE ELECTROMAGNETIC SEISMOMETER - THE OPTIMUM COIL RESISTANCE, AMPLIFIER CHARACTERISTICS, AND CIRCUIT SO BULLETIN OF THE SEISMOLOGICAL SOCIETY OF AMERICA LA English DT Article AB This study finds the optimum coil resistance, r(c.opt), which maximizes the signal-to-noise ratio (SNR) of an electromagnetic (EM) seismometer and amplifier combination. The optimum coil resistance is shown to be the product of a seismometer factor (SF) times the noise resistance, R(n), of the amplifier. The seismometer factors range from 1.13 to 3.66 for the nine EM seismometers considered. The minimum noise figure solution, in which the amplifier noise resistance is set equal to the coil resistance, is shown to correspond to the special case in which there is no damping resistor present. It is also shown that the optimum form for the noise resistance is a constant independent of frequency and that this feature can be approximated with FET-like components such as the MAT-02. Examples of using r(c.opt), are given using both the 5500-ohm and the 500-ohm 1-Hz L4-C seismometers paired with the OP-27 and LT1028 operational amplifiers, respectively. It is pointed out that, although the resulting amplitude signal-to-noise ratios (ASNRs) are approximately equal, it is best to choose the seismometer-amplifier pair having the larger generator constant because it results in a larger signal. Furthermore, if the coil resistance is not the optimum value, the resulting decrease in the ASNR is less if the coil resistance is chosen greater than the optimum rather than less. The deleterious effects of mismatching seismometer and amplifier are shown by comparing ASNRs for the GS-13 seismometer paired with three different amplifiers. The degradation in ASNR is found to be as large as a factor of 3. It is pointed out that mismatching would not be done purposely but can inadvertently occur when connecting an EM seismometer to a seismic recorder whose input noise resistance properties are unknown, as in generally the case. It is recommended that manufacturers of seismic recorders obtain the necessary input noise data from the component manufacturers and supply the input noise resistance to users. Finally, the three commonly used single-ended preamplifier circuits used for EM seismometers are compared in terms of their resulting ASNRs. The same seismometer and amplifier are used in all three circuits. For the GS-13/MAT-02 pair, the noninverting, parallel damping resistor circuit resulted in an ASNR that was 3.8 times larger than that for the inverting, parallel damping resistor circuit, and 3 times larger than that for the inverting, series damping resistor circuit. C1 UNIV CALIF SANTA BARBARA,INST CRUSTAL STUDIES,SANTA BARBARA,CA 93106. LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550. NR 10 TC 7 Z9 8 U1 0 U2 1 PU SEISMOLOGICAL SOC AMER PI EL CERRITO PA PLAZA PROFESSIONAL BLDG, SUITE 201, EL CERRITO, CA 94530 SN 0037-1106 J9 B SEISMOL SOC AM JI Bull. Seismol. Soc. Amer. PD APR PY 1993 VL 83 IS 2 BP 561 EP 582 PG 22 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA KT736 UT WOS:A1993KT73600015 ER PT J AU JOSLIN, JD WOLFE, MH AF JOSLIN, JD WOLFE, MH TI TEMPERATURE INCREASE ACCELERATES NITRATE RELEASE FROM HIGH-ELEVATION RED SPRUCE SOILS SO CANADIAN JOURNAL OF FOREST RESEARCH-REVUE CANADIENNE DE RECHERCHE FORESTIERE LA English DT Note ID FOREST ECOSYSTEMS; NORTHERN AB One possible consequence of predicted increases in global temperature is an increase in soil organic matter decomposition rates and (or) nitrification rates. In nitrogen-saturated ecosystems, such a change could lead to an increase in nitrate production, since much of the ammonium released from decomposition of organic matter would be converted to nitrate rather than taken up by plants or microorganisms. In a high-elevation red spruce (Picea rubens Sarg.) stand, soil at 15 cm below the surface of the sunny and shaded sides of a recent clearing were found to exhibit a significant temperature differential (DELTA = 1.2-degrees-C, p < 0.01). Soil solutions collected at 15 cm from the warmer, sunny side over an 18-month period had higher (p < 0.01) mean concentrations of nitrate (71% greater), Mg (58% greater), and Al (24% greater) than diose from the shaded side. Fluxes of nitrate and Mg were 30-33% higher on the sunny side of the clearing (p = 0.10, p < 0.01, respectively). If global climate changes result in accelerated releases of nitrate that are widespread in high-elevation spruce-fir forests, elevated Al levels and (or) base cation leaching losses may result, with possible negative consequences for forest health. RP JOSLIN, JD (reprint author), OAK RIDGE NATL LAB,TENNESSEE VALLEY AUTHOR,DEPT ATMOSPHER SCI,OAK RIDGE,TN 37831, USA. NR 23 TC 16 Z9 18 U1 1 U2 4 PU NATL RESEARCH COUNCIL CANADA PI OTTAWA PA RESEARCH JOURNALS, MONTREAL RD, OTTAWA ON K1A 0R6, CANADA SN 0045-5067 J9 CAN J FOREST RES JI Can. J. For. Res.-Rev. Can. Rech. For. PD APR PY 1993 VL 23 IS 4 BP 756 EP 759 DI 10.1139/x93-099 PG 4 WC Forestry SC Forestry GA LF595 UT WOS:A1993LF59500025 ER PT J AU KATO, S PETRUZZELLI, S BOWMAN, ED TURTELTAUB, KW BLOMEKE, B WESTON, A SHIELDS, PG AF KATO, S PETRUZZELLI, S BOWMAN, ED TURTELTAUB, KW BLOMEKE, B WESTON, A SHIELDS, PG TI 7-ALKYLDEOXYGUANOSINE ADDUCT DETECTION BY 2-STEP HPLC AND THE P-32 POSTLABELING ASSAY SO CARCINOGENESIS LA English DT Article ID TOBACCO-SPECIFIC NITROSAMINES; LIVER DNA; MOLECULAR EPIDEMIOLOGY; METHYLATING AGENTS; MASS-SPECTROMETRY; ETHYLATING AGENTS; NUCLEIC-ACIDS; HUMAN CANCER; RAT-LIVER; 7-METHYLGUANINE AB 7-Alkyldeoxyguanosine DNA adducts may be a marker for some N-nitroso compound exposures and subsequent human cancer risk. A sensitive and highly specific assay for the detection of 7-methyl-2'-deoxyguanosine-3'-monophosphate (7-methyldGp) and 7-ethyl-2'-deoxyguanosine-3'-monophosphate (7-ethyldGp) has been developed by combining two different HPLC purification steps with the P-32-postlabeling assay. We previously reported that ion-pair reverse-phase (IP) chromatography coupled with the P-32-postlabeling assay detects 7-methyldGp in human lung, but have found that other nucleotides and unknown adducts co-elute. Thus, weak anion exchange (AE) HPLC was added in tandem with IP HPLC prior to the P-32-postlabeling assay. 2'-Deoxyguanosine-3'-monophosphate (dGp) is incorporated into the assay as an internal standard for the assessment of enzyme labeling efficiency and adduct recovery. The methodology was validated using radiolabeled DNA and liquid scintillation counting, which accounts for adduct loss from enzymatic digestion to detection. Levels of 7-ethyldGp also were correlated with accelerator mass spectrometry. The overall adduct recovery with this method was 58% for 7-methyldGp and 98% for 7-ethyldGp. The detection limit for both assays using 100 mug of DNA was one adduct in 10(8) umnodified dGp. 7-MethyldGp and 7-ethyIdGp levels were determined in ten human lung samples at levels of 1.4 - 5.4 and 0.6 - 3.1 adducts per 10(7) dGp respectively, and in five human lymphocyte samples at levels of 5.0 - 8.3 and 0.3 - 1.4 adducts per 10(7) dGp respectively. Combining the two HPLC purification steps and the P-32-postlabeling assay attains chemical specificity, retains sufficient quantitative sensitivity and should be useful in human biomonitoring studies. C1 NCI,HUMAN CARCINOGENESIS LAB,BETHESDA,MD 20892. LAWRENCE LIVERMORE NATL LAB,DIV BIOL SCI,LIVERMORE,CA 94550. RI Shields, Peter/I-1644-2012 NR 56 TC 63 Z9 63 U1 0 U2 2 PU OXFORD UNIV PRESS PI OXFORD PA GREAT CLARENDON ST, OXFORD OX2 6DP, ENGLAND SN 0143-3334 J9 CARCINOGENESIS JI Carcinogenesis PD APR PY 1993 VL 14 IS 4 BP 545 EP 550 DI 10.1093/carcin/14.4.545 PG 6 WC Oncology SC Oncology GA KW704 UT WOS:A1993KW70400001 PM 8386066 ER PT J AU Hietarinta, J Mikkola, S AF Hietarinta, Jarmo Mikkola, Seppo TI Chaos in the one-dimensional gravitational three-body problem SO CHAOS LA English DT Article AB We have investigated the appearance of chaos in the one-dimensional Newtonian gravitational three-body system (three masses on a line with -1/r pairwise potential). In the center of mass coordinates this system has two degrees of freedom and can be conveniently studied using Poincare sections. We have concentrated in particular on how the behavior changes when the relative masses of the three bodies change. We consider only the physically more interesting case of negative total energy. For two mass choices we have calculated 18000 full orbits (with initial states on a 100 X 180 lattice on the Poincare section) and obtained dwell time distributions. For 105 mass choices we have calculated Poincare maps for 10 X 18 starting points. Our results show that the Poincare sectiorl (and hence the phase space) divides into three well defined regions with orbits of different characteristics: (1) There is a region of fast scattering, with a minimum of pairwise collisions. This region consists of 'scallops' bordering the E = 0 line, within a scallop the orbits vary smoothly. The number of the scallops increases as the mass of the central particle decreases. (2) In the chaotic scattering region the interaction times are longer, and both the interaction time and the final state depend sensitively on the starting point on the Poincare section. For both (1) and (2) the initial and final states consist of a binary + single particle. (3) The third region consists of quasiperiodic orbits where the three masses are bound together forever. At the center of the quasiperiodic region there is a periodic orbit discovered (numerically) by Schubart in 1956. The stability of the Schubart orbit turns out to correlate strongly with the global behavior. C1 [Hietarinta, Jarmo] Univ Calif Los Alamos Natl Lab, Ctr Nonlinear Studies, Los Alamos, NM 87545 USA. [Hietarinta, Jarmo; Mikkola, Seppo] Univ Turku, Dept Phys, SF-20500 Turku, Finland. [Mikkola, Seppo] Turku Univ Observ, Piikkio 21500, Finland. RP Hietarinta, J (reprint author), Univ Calif Los Alamos Natl Lab, Ctr Nonlinear Studies, POB 1663, Los Alamos, NM 87545 USA. FU Center for Nonlinear Studies, Los Alamos National Laboratory [W-4705-ENG-36] FX One of us (J.H.) would like to thank Roberto Camassa, David K. Campbell, Greg Forest, and Darryl Holm for discussions, and David K. Campbell for hospitality at the Center for Nonlinear Studies, Los Alamos National Laboratory, where this work was partially done, supported by Contract No. W-4705-ENG-36. We would also like to thank the referees for useful comments. NR 26 TC 3 Z9 3 U1 0 U2 1 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 1054-1500 J9 CHAOS JI Chaos PD APR PY 1993 VL 3 IS 2 PG 21 WC Mathematics, Applied; Physics, Mathematical SC Mathematics; Physics GA V22XS UT WOS:000208308500007 ER PT J AU Mainieri, R AF Mainieri, Ronnie TI On the equality of Hausdorff and box counting dimensions SO CHAOS LA English DT Article AB By viewing the covers of a fractal as a statistical mechanical system, the exact capacity of a multifractal is computed, The procedure can be extended to any multifractal described by a scaling function to show why the capacity and Hausdorff dimension are expected to be equal. C1 Univ Calif Los Alamos Natl Lab, Ctr Nonlinear Studies, Los Alamos, NM 87545 USA. RP Mainieri, R (reprint author), Univ Calif Los Alamos Natl Lab, Ctr Nonlinear Studies, MS B258, Los Alamos, NM 87545 USA. NR 16 TC 2 Z9 2 U1 1 U2 1 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 1054-1500 J9 CHAOS JI Chaos PD APR PY 1993 VL 3 IS 2 PG 7 WC Mathematics, Applied; Physics, Mathematical SC Mathematics; Physics GA V22XS UT WOS:000208308500001 ER PT J AU CARRADO, KA FORMAN, JE BOTTO, RE WINANS, RE AF CARRADO, KA FORMAN, JE BOTTO, RE WINANS, RE TI INCORPORATION OF PHTHALOCYANINES BY CATIONIC AND ANIONIC CLAYS VIA ION-EXCHANGE AND DIRECT SYNTHESIS SO CHEMISTRY OF MATERIALS LA English DT Article ID LAYERED DOUBLE HYDROXIDE; HYDROTALCITE-LIKE COMPOUNDS; PHYSICOCHEMICAL PROPERTIES; CROWN-ETHER; FLUORESCENCE PROPERTIES; CRYSTAL VIOLET; DYE; SYSTEMS; MONTMORILLONITE; METACHROMASY AB Phthalocyanines (Pc) and metallophthalocyanines were incorporated into the galleries of anionic and cationic clays via ion exchange and in situ crystallization of the synthetic clay layers. Intercalation compounds between the layered magnesium silicate clay hectorite and cationic phthalocyanines were directly prepared by refluxing for 2 days aqueous solutions of silica sol, magnesium hydroxide, lithium fluoride, and either alcian blue dyes (Cu(II)Pc) or 15-crown-5 tetra-substituted phthalocyanine (15C5Pc). The CuPc dyes are tetrapositively charged through peripheral quaternary ammonium groups, whereas the 15C5Pc is electrically neutral. Anionic clays prepared by hydrolysis of mixed solutions of aluminum nitrate, magnesium nitrate, and copper(II) phthalocyaninetetrasulfonic acid, tetrasodium salt (CuPcTs) in sodium hydroxide resulted in crystallization of an intercalation compound between a layered double hydroxide (LDH) and this anionic Pc. The material prepared by ion exchange of CuPcTs into a wet, freshly prepared LDH was superior in crystallinity. The phthalocyanines are oriented parallel to cationic hectorite clay layers (gallery heights 4.5-6.5 angstrom) and perpendicular to anionic layered double hydroxide clay layers (gallery height 18.2 angstrom) in correlation with their hosts' respective layer charge densities. RP CARRADO, KA (reprint author), ARGONNE NATL LAB,DIV CHEM,ARGONNE,IL 60439, USA. NR 37 TC 109 Z9 111 U1 2 U2 37 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0897-4756 J9 CHEM MATER JI Chem. Mat. PD APR PY 1993 VL 5 IS 4 BP 472 EP 478 DI 10.1021/cm00028a013 PG 7 WC Chemistry, Physical; Materials Science, Multidisciplinary SC Chemistry; Materials Science GA KY397 UT WOS:A1993KY39700013 ER PT J AU ASSINK, RA SCHWARTZ, RW AF ASSINK, RA SCHWARTZ, RW TI H-1 AND C-13 NMR INVESTIGATIONS OF PB(ZR,TI)O3 THIN-FILM PRECURSOR SOLUTIONS SO CHEMISTRY OF MATERIALS LA English DT Article ID LEAD TITANATE; PZT FILMS AB Solvent reactions, ligand substitutions, and the oligomer/polymer backbone structure are important factors in the solution preparation of ceramic films. In this study we have used H-1 and C-13 NMR spectroscopy to characterize solvent and ligand effects in precursor solutions used for the deposition of ferroelectric PZT (lead zirconate titanate) thin films. Solutions were prepared by a sequential precursor addition method from carboxylate and alkoxide precursors of the three cations, and the solvents, acetic acid, methanol, and water. The results indicate that acetic acid was a key component in the solution preparation process. As observed previously for single metallic component systems, its presence resulted in esterification reactions, leading in the present case to the formation of methyl, isopropyl, and n-butyl acetates. Second, acetic acid functioned as a chemical modifier, or chelating agent, replacing essentially all of the alkoxy ligands of the original precursors. Since alkoxy replacement appeared to be complete, we may describe the PZT species formed in solution as oxo acetate in nature. Finally, the solvent and ligand behavior of a solution prepared by an inverted mixing order was compared to the behavior of the solution prepared by a sequential precursor addition. The spectra for the two solutions were similar, and only differences in the relative intensities of the ester and alcoholic resonances were observed. C1 SANDIA NATL LABS,CTR MAT & PROC SCI,ALBUQUERQUE,NM 87185. NR 29 TC 103 Z9 103 U1 5 U2 20 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0897-4756 J9 CHEM MATER JI Chem. Mat. PD APR PY 1993 VL 5 IS 4 BP 511 EP 517 DI 10.1021/cm00028a019 PG 7 WC Chemistry, Physical; Materials Science, Multidisciplinary SC Chemistry; Materials Science GA KY397 UT WOS:A1993KY39700019 ER PT J AU BISH, DL ARONSON, JL AF BISH, DL ARONSON, JL TI PALEOGEOTHERMAL AND PALEOHYDROLOGIC CONDITIONS IN SILICIC TUFF FROM YUCCA MOUNTAIN, NEVADA SO CLAYS AND CLAY MINERALS LA English DT Article DE GEOTHERMAL GRADIENTS; ILLITE SMECTITE; K/AR DATING; X-RAY POWDER DIFFRACTION; YUCCA MOUNTAIN ID LAYER ILLITE SMECTITE; RAY-DIFFRACTION PATTERNS; JEMEZ VOLCANIC FIELD; NEW-MEXICO; QUANTITATIVE INTERPRETATION; ARGILLACEOUS SEDIMENT; BURIAL METAMORPHISM; PELITIC SEDIMENTS; DIAGENESIS; ROCKS AB The clay mineralogy of tuffs from Yucca Mountain, Nevada, the potential site of the nation's first high-level radioactive waste repository, has been studied in order to understand the alteration history of the rocks and to predict potential future alterations. Bulk-rock samples and clay-mineral separates from three drill holes at Yucca Mountain (USW G-1, USW G-2, and USW GU-3/G-3) were studied using X-ray powder diffraction, and supporting temperature information was obtained using fluid inclusion data from calcite. Twelve K/Ar dates were obtained on illite/smectite (I/S) separated from the tuffs from the two northernmost drill holes, USW G-1 and G-2. The predominant clay minerals in the Yucca Mountain tuffs are interstratified I/S, with minor amounts of chlorite and interstratified chlorite/smectite. The I/S reactions observed as a function of depth are similar to those observed for pelitic rocks; I/S transforms from R = 0 interstratifications through R = 1 and R greater-than-or-equal-to 3 interstratifications to illite in USW G-2 and to R greater-than-or-equal-to 3 I/S in USW G-1. The R = 0 I/S clays in USW GU-3/G-3 have not significantly transformed. K/Ar dates for the I/S samples average 10.4 my. These data suggest that the rocks at depth in the northern portion of Yucca Mountain were altered 10.0-11 my ago, soon after creation of the Timber Mountain caldera to the north. Both I/S geothermometry and fluid inclusion data suggest that the rocks at depth in USW G-2 were subjected to postdepositional temperatures of at least 275-degrees-C, those in USW G-1 reached 200-degrees-C, and rocks from USW GU-3/G-3 probably did not exceed 100-degrees-C. These data suggest that no significant hydrothermal alteration has occurred since Timber Mountain time, approximately 10.7 my ago. Estimates of the temperature of formation of illite/smectites yield probable stability limits for several minerals at Yucca Mountain. Clinoptilolite apparently became unstable at about 100-degrees-C, mordenite was not a major phase above 130-degrees-C, and analcime transformed to albite above 175-degrees-200-degrees-C. It appears that cristobalite transformed to quartz at 90-degrees-100-degrees-C in USW G-2 but must have reacted at considerably lower temperatures (and for longer times) in USW GU-3/G-3. The reactions with increasing depth appear coupled, and clinoptilolite and cristobalite disappear approximately simultaneously, supporting aqueous silica activity as a controlling variable in the clinoptilolite-to-analcime reaction. The reaction of clinoptilolite to analcime also coincides with the appearance of calcite, chlorite, and interstratified chlorite/smectite. Although the hydrothermal fluids may have been a source for some cations, breakdown of clinoptilolite (and mordenite) probably provided the source of some of the Ca for calcite, Mg for chlorite, K for the I/S found deeper in the section, and Na for analcime and albite. Using the rocks in USW G-1, G-2, and GU/G-3 as natural analogs to repository-induced thermal alteration suggests that the bulk of the clinoptilolite- and mordenite-bearing rocks in Yucca Mountain will not react to less sorptive phases such as analcime over the required lifetime of the potential repository. The zeolites in zeolite interval I, directly underlying the proposed repository horizon, may transform at the predicted repository temperatures. However, the reaction of clinoptilolite to analcime in interval I may require the transformation of all of the abundant opal-CT and glass to quartz, an unlikely scenario considering the unsaturated nature of these rocks and the predicted temperatures of < 100-degrees-C. C1 CASE WESTERN RESERVE UNIV, DEPT GEOL, CLEVELAND, OH 44106 USA. RP BISH, DL (reprint author), LOS ALAMOS NATL LAB, DIV EARTH & ENVIRONM SCI, MAIL STOP D469, LOS ALAMOS, NM 87545 USA. NR 77 TC 57 Z9 58 U1 0 U2 6 PU CLAY MINERALS SOC PI CHANTILLY PA 3635 CONCORDE PKWY, STE 500, CHANTILLY, VA 20151-1125 USA SN 0009-8604 EI 1552-8367 J9 CLAY CLAY MINER JI Clay Clay Min. PD APR PY 1993 VL 41 IS 2 BP 148 EP 161 DI 10.1346/CCMN.1993.0410204 PG 14 WC Chemistry, Physical; Geosciences, Multidisciplinary; Mineralogy; Soil Science SC Chemistry; Geology; Mineralogy; Agriculture GA LT507 UT WOS:A1993LT50700004 ER PT J AU MARGOLIS, SB AF MARGOLIS, SB TI A MODEL FOR CONDENSED COMBUSTION SYNTHESIS OF NONSTOICHIOMETRIC HOMOGENEOUS SOLIDS SO COMBUSTION AND FLAME LA English DT Article ID ASYMPTOTIC THEORY; PROPAGATION AB The overall composition of products formed from condensed-phase reactions typically vary in a continuous fashion according to the concentrations of the initial reactant powders. In such reactions, phase changes thus play a significant role in the ability to synthesize a homogeneous product from an initially heterogeneous mixture of reactants, such as occurs in condensed reactions between metal and nonmetal powders to form nonstoichiometric homogeneous ceramics (e.g., TiC(nu)). Here, a model is developed for such a system that allows, in tum, for melting of one of the initial components, a diffusion-limited reaction between the solid, nonmelting reactant and the molten metal to produce a solid product, melting of the solid product, and finally, reaction to completion according to a kinetics-limited rate law. As with purely homogeneous (kinetics-limited) or heterogeneous (diffusion-limited) models, the present problem, which on an overall basis incorporates both types of processes, may be analyzed in the realistic limit of large activation energies of both diffusion and reaction. This provides an asymptotic, flame-sheet type of formulation of the problem, which in tum yields an analytical expression for the steady, planar burning rate eigenvalue, and allows the explicit determination of the stability boundary that corresponds to the transition from steady to nonsteady combustion known to occur in these types of systems. RP MARGOLIS, SB (reprint author), SANDIA NATL LABS,COMBUST RES FACIL,LIVERMORE,CA 94551, USA. NR 19 TC 3 Z9 3 U1 0 U2 0 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 APR PY 1993 VL 93 IS 1-2 BP 1 EP 18 DI 10.1016/0010-2180(93)90080-M PG 18 WC Thermodynamics; Energy & Fuels; Engineering, Multidisciplinary; Engineering, Chemical; Engineering, Mechanical SC Thermodynamics; Energy & Fuels; Engineering GA KU551 UT WOS:A1993KU55100001 ER PT J AU PHUOC, TX MATHUR, MP EKMANN, JM AF PHUOC, TX MATHUR, MP EKMANN, JM TI HIGH-ENERGY ND-YAG LASER IGNITION OF COALS - EXPERIMENTAL-OBSERVATIONS SO COMBUSTION AND FLAME LA English DT Article ID PYROLYSIS AB Some experiments were Conducted to study the interaction of the Nd-Yag laser radiation with four different coals. All coals were ground and screened to 400 mesh and then pressed into cylindrical pellets of 3 mm diameter and 2 mm length. The coal pellets were prepared by cold pressing using a stainless-steel die to a pressure of about 500 kg/cm2. Laser intensities ranging from 0.5 x 10(3) to 1.5 x 10(4) W/cm2 at 1.064 mum wavelength and a pulse duration of 5 ms were used. For laser intensities less than 800 W/cm2, no ignition was observed for all coals. For laser intensities above this value, two ignition mechanisms were observed: the surface ignition followed by the gas-phase ignition when Wyoming subbituminous, Indian lignite, and North Dakota lignite coals were used. For the same range of the laser intensities, however, only the gas-phase ignition was observed when Pittsburgh bituminous coal was used. It was also noted that a significant amount of the external laser radiations were absorbed by the pyrolysis products during the early stages of the ignition period. This process leads to a series of nonlinear phenomena and dictates not only the processes occurring at the coal surface but also in the gas phase. RP PHUOC, TX (reprint author), US DOE,PITTSBURGH ENERGY TECHNOL CTR,POB 10940,MS 84-340,PITTSBURGH,PA 15236, USA. NR 12 TC 19 Z9 20 U1 0 U2 0 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 APR PY 1993 VL 93 IS 1-2 BP 19 EP 30 DI 10.1016/0010-2180(93)90081-D PG 12 WC Thermodynamics; Energy & Fuels; Engineering, Multidisciplinary; Engineering, Chemical; Engineering, Mechanical SC Thermodynamics; Energy & Fuels; Engineering GA KU551 UT WOS:A1993KU55100002 ER PT J AU EBBINGHAUS, BB AF EBBINGHAUS, BB TI THERMODYNAMICS OF GAS-PHASE CHROMIUM SPECIES - THE CHROMIUM OXIDES, THE CHROMIUM OXYHYDROXIDES, AND VOLATILITY CALCULATIONS IN WASTE INCINERATION PROCESSES SO COMBUSTION AND FLAME LA English DT Article ID MOLECULAR-STRUCTURE; STATE; TRICHLORIDE; CRF5 AB The thermodynamics of three gaseous chromium oxides and twelve gaseous chromium oxyhydroxides are assessed for application to chromium volatility calculations in waste incineration processes. For the oxyhydroxides, the thermodynamic properties, S0(298), H0(298) - H0(0), -(G0(T) - H0(298))/T, and C(p)0(T), are calculated by the molecular constant method using estimated molecular parameters. The enthalpies of formation, DELTAH(f)0(298), of the chromium oxides and the chromium oxyhydroxides are determined either from vapor pressure data when available or from bond energy correlations which use available data on the gaseous chromium oxyhalides. The thermodynamic constants, S0(298), DELTAH(f)0(298), and H0(298) - H0(0), are tabulated for all fifteen gaseous species. Likewise, the thermodynamic functions, -(G0(T) - H0(298))/T and C(p)0(T), are given in polynomial form as a function of temperature for ranges from 298 to 1000 K and 1000 to 3000 K. Equilibrium vapor compositions over Cr2O3(s) at fixed partial pressures of oxygen (0.10 atm) and water (0.10 atm) and temperatures in the range of 800 to 1600 K show that CrO2(OH)2(g) is the dominant vapor species with small contributions from CrO(OH)3(g), CrO3(g), CrO2OH(g), and CrO(OH)2(g). RP EBBINGHAUS, BB (reprint author), LAWRENCE LIVERMORE NATL LAB, POB 808, L-369, LIVERMORE, CA 94550 USA. NR 55 TC 203 Z9 208 U1 0 U2 24 PU ELSEVIER SCIENCE INC PI NEW YORK PA 360 PARK AVE SOUTH, NEW YORK, NY 10010-1710 USA SN 0010-2180 EI 1556-2921 J9 COMBUST FLAME JI Combust. Flame PD APR PY 1993 VL 93 IS 1-2 BP 119 EP 137 DI 10.1016/0010-2180(93)90087-J PG 19 WC Thermodynamics; Energy & Fuels; Engineering, Multidisciplinary; Engineering, Chemical; Engineering, Mechanical SC Thermodynamics; Energy & Fuels; Engineering GA KU551 UT WOS:A1993KU55100008 ER PT J AU TRUONG, TN LU, DH LYNCH, GC LIU, YP MELISSAS, VS STEWART, JJP STECKLER, R GARRETT, BC ISAACSON, AD GONZALEZLAFONT, A RAI, SN HANCOCK, GC JOSEPH, T TRUHLAR, DG AF TRUONG, TN LU, DH LYNCH, GC LIU, YP MELISSAS, VS STEWART, JJP STECKLER, R GARRETT, BC ISAACSON, AD GONZALEZLAFONT, A RAI, SN HANCOCK, GC JOSEPH, T TRUHLAR, DG TI MORATE - A PROGRAM FOR DIRECT DYNAMICS CALCULATIONS OF CHEMICAL-REACTION RATES BY SEMIEMPIRICAL MOLECULAR-ORBITAL THEORY SO COMPUTER PHYSICS COMMUNICATIONS LA English DT Article ID TRANSITION-STATE THEORY; INTRINSIC REACTION COORDINATE; CANONICAL VARIATIONAL THEORY; CLASSICAL MECHANICAL THEORY; POTENTIAL-ENERGY SURFACE; COLLINEAR REACTIONS; TUNNELING CALCULATIONS; POLYATOMIC-MOLECULES; HYDROGEN MOLECULES; REACTION PATHS AB We present a computer program, MORATE (Molecular Orbital RATE calculations), for direct dynamics calculations of unimolecular and bimolecular rate constants of gas-phase chemical reactions involving atoms, diatoms, or polyatomic species. The potential energies, gradients, and higher derivatives of the potential are calculated whenever needed by semiempirical molecular orbital theory without the intermediary of a global or semiglobal fit. The dynamical methods used are conventional or variational transition state theory and multidimensional semiclassical approximations for tunneling and nonclassical reflection. The computer program is a conveniently interfaced package consisting of the POLYRATE program, version 4.5.1, for dynamical rate calculations, and the MOPAC program, version 5.03, for semiempirical electronic structure computations. All semiempirical methods available in MOPAC, in particular MINDO/3, MNDO, AM1, and PM3, can be called on to calculate the potential and gradient. Higher derivatives of the potential are obtained by numerical derivatives of the gradient. Variational transition states are found by a one-dimensional search of generalized-transition-state dividing surfaces perpendicular to the minimum-energy path, and tunneling probabilities are evaluated by numerical quadrature. C1 UNIV MINNESOTA, DEPT CHEM, MINNEAPOLIS, MN 55455 USA. PACIFIC NW LAB, MOLEC SCI RES CTR, RICHLAND, WA 99352 USA. MIAMI UNIV, DEPT CHEM, OXFORD, OH 45056 USA. UNIV MINNESOTA, INST SUPERCOMP, MINNEAPOLIS, MN 55455 USA. STEWART COMPUTAT CHEM, COLORADO SPRINGS, CO 80921 USA. SAN DIEGO SUPERCOMP CTR, SAN DIEGO, CA 92186 USA. UNIV AUTONOMA BARCELONA, DEPT QUIM, UNIDAD QUIM FIS, E-08193 BARCELONA, SPAIN. RI Garrett, Bruce/F-8516-2011; Gonzalez-Lafont, Angels/L-4898-2014; Truhlar, Donald/G-7076-2015 OI Gonzalez-Lafont, Angels/0000-0003-0729-2483; Truhlar, Donald/0000-0002-7742-7294 NR 67 TC 87 Z9 88 U1 1 U2 9 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0010-4655 J9 COMPUT PHYS COMMUN JI Comput. Phys. Commun. PD APR PY 1993 VL 75 IS 1-2 BP 143 EP 159 DI 10.1016/0010-4655(93)90172-9 PG 17 WC Computer Science, Interdisciplinary Applications; Physics, Mathematical SC Computer Science; Physics GA KV577 UT WOS:A1993KV57700013 ER PT J AU KRAUSE, F BUSCH, J KOOMEY, JG AF KRAUSE, F BUSCH, J KOOMEY, JG TI CARBON-REDUCTION COSTS IN NEW-ENGLAND POWER SECTOR SO CONTEMPORARY POLICY ISSUES LA English DT Article; Proceedings Paper CT GENERAL SESSION OF THE 67TH ANNUAL CONF OF THE WESTERN ECONOMIC ASSOC INTERNATIONAL CY JUL 10, 1992 CL SAN FRANCISCO, CA SP W ECON ASSOC INT AB This paper examines the cost of reducing carbon emissions in New England's power sector. The analysis relies on detailed sectoral studies of costs and resource potentials for demand-side efficiency, cogeneration, renewables, and conventional resource options. Sectoral studies' results were integrated using a production-cost model to estimate the total cost and rate impacts of carbon reduction strategies relative to a business-as-usual forecast. To capture potential uncertainties, the analysis takes into account variations in capital costs, fuel prices, resource utilization levels, and base case retirements of existing power plants. Results show that New England's power sector can freeze carbon emissions at current levels or reduce carbon emissions while simultaneously decreasing customers' total electricity bills. RP KRAUSE, F (reprint author), LAWRENCE BERKELEY LAB,DIV ENERGY & ENVIRONM,ENERGY ANAL PROGRAM,BERKELEY,CA 94720, USA. NR 7 TC 0 Z9 0 U1 0 U2 0 PU WESTERN ECONOMIC ASSOC INT PI HUNTINGTON BEACH PA 7400 CENTER AVE SUITE 109, HUNTINGTON BEACH, CA 92647-3039 SN 0735-0007 J9 CONTEMP POLICY ISSUE PD APR PY 1993 VL 11 IS 2 BP 100 EP 112 PG 13 WC Economics; Public Administration SC Business & Economics; Public Administration GA LA440 UT WOS:A1993LA44000008 ER PT J AU RUBINSKY, B GILBERT, JC ONIK, GM ROOS, MS WONG, STS BRENNAN, KM AF RUBINSKY, B GILBERT, JC ONIK, GM ROOS, MS WONG, STS BRENNAN, KM TI MONITORING CRYOSURGERY IN THE BRAIN AND IN THE PROSTATE WITH PROTON NMR SO CRYOBIOLOGY LA English DT Note ID HEPATIC CRYOSURGERY; ANIMAL-MODEL C1 LAWRENCE BERKELEY LAB,DIV LIFE SCI,CTR FUNCT IMAGING,BERKELEY,CA 94720. ALLEGHENY GEN HOSP,DEPT CRYOMED,PITTSBURGH,PA 15212. RP RUBINSKY, B (reprint author), UNIV CALIF BERKELEY,DEPT MECH ENGN,BERKELEY,CA 94720, USA. RI Rubinsky, Boris/B-4439-2010 OI Rubinsky, Boris/0000-0002-2794-1543 NR 16 TC 57 Z9 57 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 0011-2240 J9 CRYOBIOLOGY JI Cryobiology PD APR PY 1993 VL 30 IS 2 BP 191 EP 199 DI 10.1006/cryo.1993.1019 PG 9 WC Biology; Physiology SC Life Sciences & Biomedicine - Other Topics; Physiology GA KX236 UT WOS:A1993KX23600010 PM 8319488 ER PT J AU WEIGEL, HS WILCOX, SP AF WEIGEL, HS WILCOX, SP TI THE ARMY PERSONNEL DECISION SUPPORT SYSTEM SO DECISION SUPPORT SYSTEMS LA English DT Article DE PERSONNEL MODELING; DECISION SUPPORT SYSTEMS; GOAL PROGRAMMING; NETWORK FLOW MODELING; MANPOWER PLANNING; MILITARY MANPOWER MODELS; MARKOV (TRANSITION RATE) PERSONNEL MODELS AB The Army's enlisted personnel decision support system combines a variety of modeling techniques, such as goal programming, network models, linear programming, and Markov-type inventory projection, with a management information system to support analysis of personnel planning issues. Using a hierarchy of models, personnel planning decisions are coordinated from the macroscopic, public policy level to the very detailed, unit and military occupational specialty level. This decision support system employs models that combine the full range of modeling methodologies with mechanisms to assure integration between organizational levels. C1 GEN RES CORP,VIENNA,VA. RP WEIGEL, HS (reprint author), US DOE,ENERGY INFORMAT ADM,OFF ENERGY MARKETS & END USE,WASHINGTON,DC 20585, USA. NR 23 TC 7 Z9 7 U1 1 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0167-9236 J9 DECIS SUPPORT SYST JI Decis. Support Syst. PD APR PY 1993 VL 9 IS 3 BP 281 EP 306 DI 10.1016/0167-9236(93)90059-C PG 26 WC Computer Science, Artificial Intelligence; Computer Science, Information Systems; Operations Research & Management Science SC Computer Science; Operations Research & Management Science GA KW836 UT WOS:A1993KW83600005 ER PT J AU WENDLANDT, E DEPAOLO, DJ BALDRIDGE, WS AF WENDLANDT, E DEPAOLO, DJ BALDRIDGE, WS TI ND AND SR ISOTOPE CHRONOSTRATIGRAPHY OF COLORADO PLATEAU LITHOSPHERE - IMPLICATIONS FOR MAGMATIC AND TECTONIC UNDERPLATING OF THE CONTINENTAL-CRUST SO EARTH AND PLANETARY SCIENCE LETTERS LA English DT Article ID WESTERN UNITED-STATES; NAVAJO VOLCANIC FIELD; NEW-MEXICO; SM-ND; CHEMICAL CONSTRAINTS; NORTH QUEENSLAND; RB-SR; XENOLITHS; GARNET; NEODYMIUM AB Nd-Sr isotopes and major and trace element abundances were measured in lower and upper crustal xenoliths carried in Tertiary minettes and kimberlitic diatremes of the Colorado Plateau. The objective was to establish the vertical distribution of mantle extraction ages for an undisturbed Precambrian crustal province characterized by normal thickness and low cratonic heat flow, and to thereby evaluate the importance of magmatic or tectonic underplating in crustal growth. Mid-Proterozoic-age (1.7-2.0 Ga) material is found at all levels of the crust. Although mafic granulites and amphibolites have major and trace element compositions compatible with an origin as magmatically underplated material, Nd model ages do not indicate that there has been significant mantle contribution to the lower crust by igneous processes (such as magmatic underplating) since the main crust-forming event ca. 1.85 Ga ago. The meta-igneous lower crustal xenoliths have relatively radiogenic Nd isotopic compositions and unradiogenic Sr compositions. There is little variability in Nd model ages in spite of large variability in Sm/Nd. High and variable Sm/Nd ratios were therefore established early in the history of the protolith, during igneous or metamorphic processes coincident with or shortly after extraction from the mantle. Metapelitic xenoliths, tectonically emplaced into the lower crust, have the same Proterozoic model ages as meta-igneous parts of the lower crust. These paragneisses are probably arc-associated sediments that were underthrust during terrane accretion in the Proterozoic. The isotopic data indicate that eclogite xenoliths are likely to represent Proterozoic lithosphere rather than subducted Mesozoic MORB, as previously proposed. A number of the eclogite xenoliths have experienced a metasomatic event which introduced LREE, SiO2 and Na2O and shifted the Nd and Sr isotopic compositions. The least-altered eclogite xenoliths have major and trace element and radiogenic Nd isotopic compositions similar to those of other Proterozoic mafic, lower crustal xenoliths. A more plausible protolith for the eclogites is Proterozoic lithosphere that was metamorphosed to eclogite facies conditions either during Precambrian continental assembly or in more recent times. C1 LAWRENCE BERKELEY LAB,DIV EARTH SCI,BERKELEY,CA 94720. LOS ALAMOS NATL LAB,DIV EARTH & ENVIRONM SCI,LOS ALAMOS,NM 87545. RP WENDLANDT, E (reprint author), UNIV CALIF BERKELEY,DEPT GEOL & GEOPHYS,CTR ISOTOPE GEOCHEM,BERKELEY,CA 94720, USA. NR 61 TC 64 Z9 64 U1 0 U2 7 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0012-821X J9 EARTH PLANET SC LETT JI Earth Planet. Sci. Lett. PD APR PY 1993 VL 116 IS 1-4 BP 23 EP 43 DI 10.1016/0012-821X(93)90043-9 PG 21 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA LA737 UT WOS:A1993LA73700003 ER PT J AU ROSENBERG, ND SPERA, FJ HAYMON, RM AF ROSENBERG, ND SPERA, FJ HAYMON, RM TI THE RELATIONSHIP BETWEEN FLOW AND PERMEABILITY FIELD IN SEA-FLOOR HYDROTHERMAL SYSTEMS SO EARTH AND PLANETARY SCIENCE LETTERS LA English DT Article ID MID-OCEAN RIDGES; COSTA-RICA RIFT; EASTERN EQUATORIAL PACIFIC; GALAPAGOS SPREADING CENTER; DE-FUCA RIDGE; POROUS-MEDIUM; THERMAL-CONVECTION; HEAT-TRANSFER; NUMERICAL-MODELS; MAGMA CHAMBER AB The permeability of oceanic crust is spatially variable and probably anisotropic as well. Using realistic permeability fields for young oceanic crust, we have performed numerical simulations of finite amplitude, steady and unsteady convective fluid flow in layered and/or anisotropic porous media heated from below to investigate particular patterns of fluid flow and temperature in mid-ocean ridge hydrothermal systems. On the flanks of mid-ocean ridges, permeability measurements in deep-sea boreholes suggest that only the top few hundred meters of oceanic crust is permeable. Given this permeability structure (and assuming some minimum permeability and layer thickness), our models predict that convection occurs in the form of numerous cells with aspect ratios of order unity within this permeable layer. Such convection results in fluid flux and diagenetic reactions within the permeable layer with a negligible effect on heat flow at the seafloor, in agreement with field observations. Estimates of oceanic crust permeability based on hydrothermal veins in ophiolites and measurements in deep-sea boreholes suggest that pillow basalts/lava flows are much more permeable than underlying sheeted dikes. This is particularly true at the ridge crest where voids have not vet collapsed and filled. Given this permeability structure, our study suggest that a small percentage of the fluid entering the ridge crest circulates through the sheeted dikes before exiting the system at high temperatures in very focused discharge zones. In our models, these discharge zones narrow considerably at the interface between the sheeted dikes and the pillow basalts/lava flows. Much of the fluid entering the system, however, never circulates below the pillow basalts/lava flows and exits the seafloor at low temperatures. In general, discharge zones are more focused than recharge zones. These results are consistent with observations of narrow and focused discharge zones in ophiolites and localized high-temperature venting amid widespread low-temperature flow on the ridge crest. The spacing of upflow zones at the surface is strongly controlled by convective flow in the bottom permeable layer. In our models, near-field effects dominate over far-field effects in systems with lateral variations in permeability, and no large-scale flow develops between widely spaced areas of contrasting permeability. The time to steady-state and evolution of convective flow in porous media vary considerably with initial conditions. Our simulations suggest that the time to steady-state is relatively long and that it is possible that hydrothermal convection at the ridge axis never reaches a steady-state flow pattern, in the sense that the variations in the system boundary conditions such as basal heat flux may occur on a time scale less than the response time of the hydrothermal system. It is possible, however, that these systems may be quasi-steady for significant periods of time. C1 UNIV CALIF SANTA BARBARA,DEPT GEOL SCI,SANTA BARBARA,CA 93106. UNIV CALIF SANTA BARBARA,INST CRUSTAL STUDIES,SANTA BARBARA,CA 93106. UNIV CALIF SANTA BARBARA,INST MARINE SCI,SANTA BARBARA,CA 93106. RP ROSENBERG, ND (reprint author), LOS ALAMOS NATL LAB,DIV EARTH & ENVIRONM SCI EES-5,MS F665,LOS ALAMOS,NM 87545, USA. RI Wright, Dawn/A-4518-2011 OI Wright, Dawn/0000-0002-2997-7611 NR 84 TC 51 Z9 51 U1 2 U2 5 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0012-821X J9 EARTH PLANET SC LETT JI Earth Planet. Sci. Lett. PD APR PY 1993 VL 116 IS 1-4 BP 135 EP 153 DI 10.1016/0012-821X(93)90050-J PG 19 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA LA737 UT WOS:A1993LA73700010 ER PT J AU LEAR, KL CHALMERS, SA KILLEEN, KP AF LEAR, KL CHALMERS, SA KILLEEN, KP TI LOW-THRESHOLD VOLTAGE VERTICAL-CAVITY SURFACE-EMITTING LASER SO ELECTRONICS LETTERS LA English DT Article DE LASERS; SEMICONDUCTOR LASERS ID DISTRIBUTED BRAGG REFLECTORS AB Vertical-cavity surface emitting laser diodes with threshold voltages as low as 1.48 V are demonstrated. The devices have low-resistance epitaxial mirrors, and current passes through the entire mirror stack. The low threshold voltage results from both low threshold current densities and mirrors with low resistivities even at low current densities. The laser fabrication sequence is relatively quick and simple and allows for the rapid characterisation of vertical-cavity surface-emitting laser material. RP LEAR, KL (reprint author), SANDIA NATL LABS,DEPT PHOTON RES 1312,POB 5800,ALBUQUERQUE,NM 87185, USA. NR 8 TC 20 Z9 20 U1 0 U2 2 PU IEE-INST ELEC ENG PI HERTFORD PA MICHAEL FARADAY HOUSE SIX HILLS WAY STEVENAGE, HERTFORD, ENGLAND SG1 2AY SN 0013-5194 J9 ELECTRON LETT JI Electron. Lett. PD APR 1 PY 1993 VL 29 IS 7 BP 584 EP 586 DI 10.1049/el:19930392 PG 3 WC Engineering, Electrical & Electronic SC Engineering GA LB770 UT WOS:A1993LB77000008 ER PT J AU ZHANG, TY FAN, JB RINGQUIST, S SMITH, CL CANTOR, CR AF ZHANG, TY FAN, JB RINGQUIST, S SMITH, CL CANTOR, CR TI THE 0.7 TO 3.3 MEGABASE CHROMOSOMES FROM CANDIDA, KLUYVEROMYCES, AND PICHIA PROVIDE ACCURATE SIZE STANDARDS FOR PULSED-FIELD GEL-ELECTROPHORESIS SO ELECTROPHORESIS LA English DT Article ID SACCHAROMYCES-CEREVISIAE; DNA-MOLECULES; YEAST; SEPARATION; KARYOTYPE; ALBICANS; CLEAVAGE; MAP AB Pulsed field gel electrophoresis was used to size intact chromosomal DNAs from Candida albicans, Kluyveromyces lactis, Pichia scolyti, and Pichia mississippiensis by optimization methods using, as size standards, concatenated bacteriophage lambda DNA, and intact and NotI digestion products of Schizosaccharomyces pombe chromosomal DNAs. These newly sized fungal DNAs can now serve as convenient and accurate size standards for DNA molecules between 0.7 and 3.3 megabases (Mb). These size standards are valid over a wide range of different electrophoretic conditions. C1 BOSTON UNIV,CTR ADV BIOTECHNOL,BOSTON,MA 02215. LAWRENCE BERKELEY LAB,DIV STRUCT BIOL,BERKELEY,CA 94720. UNIV CALIF SAN FRANCISCO,CTR HUMAN GENOME MAPPING,SAN FRANCISCO,CA 94143. UNIV COLORADO,DEPT MOLEC CELLULAR & DEV BIOL,BOULDER,CO 80309. OI Smith, Cassandra/0000-0002-0346-8907 NR 23 TC 5 Z9 5 U1 0 U2 0 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 APR PY 1993 VL 14 IS 4 BP 290 EP 295 DI 10.1002/elps.1150140151 PG 6 WC Biochemical Research Methods; Chemistry, Analytical SC Biochemistry & Molecular Biology; Chemistry GA LC165 UT WOS:A1993LC16500008 PM 8500459 ER PT J AU BELLEFROID, EJ MARINE, JC RIED, T LECOCQ, PJ RIVIERE, M AMEMIYA, C PONCELET, DA COULIE, PG DEJONG, P SZPIRER, C WARD, DC MARTIAL, JA AF BELLEFROID, EJ MARINE, JC RIED, T LECOCQ, PJ RIVIERE, M AMEMIYA, C PONCELET, DA COULIE, PG DEJONG, P SZPIRER, C WARD, DC MARTIAL, JA TI CLUSTERED ORGANIZATION OF HOMOLOGOUS KRAB ZINC-FINGER GENES WITH ENHANCED EXPRESSION IN HUMAN T-LYMPHOID CELLS SO EMBO JOURNAL LA English DT Article DE ALTERNATIVE SPLICING; GENE CLUSTER; HUMAN; T-LYMPHOCYTES; ZINC FINGER ID TRANSCRIPTION FACTOR-IIIA; MULTIGENE FAMILY; CHROMOSOMAL LOCALIZATION; INSITU HYBRIDIZATION; MESSENGER-RNAS; XENOPUS-LAEVIS; PROTEIN GENE; KRUPPEL; MOUSE; INVITRO AB KRAB zinc-finger proteins (KRAB-ZFPs) constitute a large subfamily of ZFPs of the Kruppel C2H2 type. KRAB (Kruppel-associated box) is an evolutionarily conserved protein domain found N-terminally with respect to the finger repeats. We report here the characterization of a particular subgroup of highly related human KRAB-ZFPs. ZNF91 is one representative of this subgroup and contains 35 contiguous ringer repeats at its C-terminus. Three mRNA isoforms with sequence identity to ZNF91 were isolated by the polymerase chain reaction. These encode proteins with a KRAB domain present, partially deleted or absent. Five genomic fragments were characterized, each encoding part of a gene: the ZNF91 gene or one of four distinct, related KRAB-ZFP genes. All exhibit a common exon/intron organization with the variant zinc finger repeats organized in a single exon and the KRAB domain encoded by two separate exons. This positioning of introns supports the hypothesis that the mRNA isoforms encoding polypeptides with variability in the KRAB domain could arise by alternative splicing. By in situ chromosomal mapping studies and by analysis of fragments from a human genomic yeast artificial chromosome library containing KRAB-ZFP genes, we show that these genes occur in clusters; in particular, a gene complex containing over 40 genes has been identified in chromosomal region 19p12-p13.1. These ZNF91-related genes probably arose late during evolution since no homologous genes are detected in the mouse and rat genomes. Although the transcription of members of this KRAB-ZFP gene subgroup is detectable in atl human tissues, their expression is significantly higher in human T lymphoid cells. C1 YALE UNIV,SCH MED,DEPT GENET,NEW HAVEN,CT 06510. UNIV LIBRE BRUXELLES,DEPT BIOL MOLEC,B-1640 RHODE ST GENESE,BELGIUM. LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94551. UNIV CATHOLIQUE LOUVAIN,INST LUDWIG,B-1200 BRUSSELS,BELGIUM. RP BELLEFROID, EJ (reprint author), STATE UNIV LIEGE,INST CHIM B6,BIOL MOLEC & GENIE GENET LAB,B-4000 SART,BELGIUM. RI Marine, Jean Christophe/J-2237-2015; Marine, Jean-Christophe/K-3292-2016 OI Marine, Jean-Christophe/0000-0003-2433-9837 FU NHGRI NIH HHS [HG00272] NR 62 TC 122 Z9 126 U1 0 U2 3 PU OXFORD UNIV PRESS UNITED KINGDOM PI OXFORD PA WALTON ST JOURNALS DEPT, OXFORD, ENGLAND OX2 6DP SN 0261-4189 J9 EMBO J JI Embo J. PD APR PY 1993 VL 12 IS 4 BP 1363 EP 1374 PG 12 WC Biochemistry & Molecular Biology; Cell Biology SC Biochemistry & Molecular Biology; Cell Biology GA KW390 UT WOS:A1993KW39000011 PM 8467795 ER PT J AU STEVENSON, GG AF STEVENSON, GG TI THE COMPETITIVENESS OF COAL BRIQUETTES IN PAKISTAN SO ENERGY LA English DT Article AB Firewood and charcoal use in Pakistan has led to extensive deforestation, whereas kerosene use depletes the country's foreign exchange earnings. Substituting coal briquettes from indigenous coal for these fuels in residential and commercial, institutional, and light-industrial cooking and heating could help alleviate these problems. We evaluate the potential financial success of an unsubsidized, private sector, coal-briquetting venture in Pakistan and find that coal briquettes could compete successfully with firewood in some markets, particularly in urban areas of the Punjab and the North West Frontier Province, as well as with charcoal and kerosene in most areas of Pakistan. Our consumer testing indicates that residential consumers are relatively positive on briquette use for cooking and space heating, while most commercial users probably would adopt briquettes more slowly. The most promising briquette is a coal-biomass mixture not requiring carbonization. Briquette marketing and distribution, the impact of government tax and competing fuels policies, and the health effects of coal-briquette emissions are also examined. RP STEVENSON, GG (reprint author), OAK RIDGE NATL LAB,POB 2008,OAK RIDGE,TN 37831, USA. NR 8 TC 1 Z9 1 U1 0 U2 2 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0360-5442 J9 ENERGY JI Energy PD APR PY 1993 VL 18 IS 4 BP 371 EP 396 DI 10.1016/0360-5442(93)90072-L PG 26 WC Thermodynamics; Energy & Fuels SC Thermodynamics; Energy & Fuels GA KP125 UT WOS:A1993KP12500007 ER PT J AU POYER, DA WILLIAMS, M AF POYER, DA WILLIAMS, M TI RESIDENTIAL ENERGY DEMAND - ADDITIONAL EMPIRICAL-EVIDENCE BY MINORITY HOUSEHOLD TYPE SO ENERGY ECONOMICS LA English DT Article DE ELASTICITY; MINORITY V MAJORITY HOUSEHOLDS ID GASOLINE AB In a number of recent studies household level data for specific urban areas or national household level micro-data have been used to estimate price and income elasticities of energy demand. None of this literature, however, provides us with elasticity estimates by minority/majority household type. The main focus of this paper is to measure the responsiveness of the quantity of electricity and total energy demanded for Black, Hispanic, and Majority households to price and income. Price and income elasticities are compared among these groups over the short and long term. A variable elasticity demand model is estimated. The elasticities are allowed to vary with respect to non-price and income variables. The price elasticities of demand vary with heating and cooling degree days and the income elasticities with the number of household members. Mean estimates were calculated over the respective samples. Findings indicate that demand for electricity is relatively price inelastic irrespective of household group. However, Blacks are more sensitive to variations in the short run to price than Hispanic and Majority households. In the long run, Blacks are also more sensitive to price changes but the magnitude of the response to price changes in the long run relative to the short run is larger for Hispanics and Majority households respectively than for Blacks. C1 ARGONNE NATL LAB,ARGONNE,IL 60115. RP POYER, DA (reprint author), NO ILLINOIS UNIV,DEPT ECON,DE KALB,IL 60115, USA. NR 20 TC 18 Z9 18 U1 0 U2 2 PU BUTTERWORTH-HEINEMANN LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, OXON, ENGLAND OX5 1GB SN 0140-9883 J9 ENERG ECON JI Energy Econ. PD APR PY 1993 VL 15 IS 2 BP 93 EP 100 DI 10.1016/0140-9883(93)90027-O PG 8 WC Economics SC Business & Economics GA KX739 UT WOS:A1993KX73900004 ER PT J AU CLARKE, JF EDMONDS, JA AF CLARKE, JF EDMONDS, JA TI MODELING ENERGY TECHNOLOGIES IN A COMPETITIVE MARKET SO ENERGY ECONOMICS LA English DT Article DE MODELING ENERGY TECHNOLOGY; COMPETITIVE MARKETS; MARKET SHARE AB Energy/economic models must predict the mix of energy technologies in competitive energy markets. We examine a market composed of several competing technologies with geographically heterogeneous cost distributions. An approach for determining both the market share and average market cost of energy produced by these technologies is derived. The formalism developed, which is based on a conditional least cost distribution function, can be used to correct the conventional logit treatment of these quantities in several existing models and to better interpret empirical data in order to determine more realistic cost distribution functions for energy technologies. RP CLARKE, JF (reprint author), PACIFIC NW LAB, RICHLAND, WA 99352 USA. NR 4 TC 42 Z9 42 U1 0 U2 7 PU BUTTERWORTH-HEINEMANN LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, OXON, ENGLAND OX5 1GB SN 0140-9883 J9 ENERG ECON JI Energy Econ. PD APR PY 1993 VL 15 IS 2 BP 123 EP 129 DI 10.1016/0140-9883(93)90031-L PG 7 WC Economics SC Business & Economics GA KX739 UT WOS:A1993KX73900008 ER PT J AU BROWN, MA AF BROWN, MA TI THE EFFECTIVENESS OF CODES AND MARKETING IN PROMOTING ENERGY-EFFICIENT HOME CONSTRUCTION SO ENERGY POLICY LA English DT Article DE ENERGY EFFICIENCY; BUILDING CODES AND STANDARDS AB This paper assesses the relative effectiveness of codes and marketing as alternative approaches to promoting energy-efficient new homes. Insights are drawn primarily from the experiences of a code and a marketing programme operated in the Pacific Northwest. The penetration rates of the two programmes are similar, as are the energy savings and costs. However, other aspects of the two programmes are quite distinct. Compared to the code programme, participants in the marketing programme tend to be more affluent and include more free riders as a result of the self-selection bias associated with voluntary participation. The marketing programme has also had greater geographic coverage, and as a result more widespread impact on region-wide building practices. Levels of involvement of utilities and code officials and impacts on fuel switching also differ. Bonneville has shown that by operating both programmes in tandem, the shortfalls of one approach can be partly compensated by the strengths of the other. RP BROWN, MA (reprint author), OAK RIDGE NATL LAB,POB 2008,OAK RIDGE,TN 37831, USA. NR 21 TC 2 Z9 2 U1 0 U2 2 PU BUTTERWORTH-HEINEMANN LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, OXON, ENGLAND OX5 1GB SN 0301-4215 J9 ENERG POLICY JI Energy Policy PD APR PY 1993 VL 21 IS 4 BP 391 EP 402 DI 10.1016/0301-4215(93)90279-O PG 12 WC Energy & Fuels; Environmental Sciences; Environmental Studies SC Energy & Fuels; Environmental Sciences & Ecology GA KW718 UT WOS:A1993KW71800006 ER PT J AU MARCHBANKS, RD JAMSHIDI, M AF MARCHBANKS, RD JAMSHIDI, M TI A FUZZY CONTROL APPROACH TO A 2-AXIS MIRROR LASER-BEAM ALIGNMENT SYSTEM SO ENGINEERING APPLICATIONS OF ARTIFICIAL INTELLIGENCE LA English DT Article DE FUZZY LOGIC; CONTROL; SYSTEMS; LASER TRACKING AB Fuzzy logic and fuzzy expert control systems have been one of the most active research and development areas of artificial intelligence in recent years. Thanks to tremendous technical advances and industrial applications in Japan, fuzzy logic enjoys an unprecedented popularity. In this paper fuzzy logic is used to control a two-axis mirror gimbal for aligning a laser beam onto the center of a target (quadrant detector). A PC-based controller is implemented with a simple rule set to control and stabilize the device. A comparison between a non-fuzzy (full-state) proportional controller and the fuzzy controller was made. Experiments were performed to study the tracking characteristics and the effect of rule pruning on the system response. Considerable improvements on the overshoot and response time of the system under fuzzy control have been achieved. The paper presents the problem, hardware, software, and the experimental results. C1 LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545. UNIV NEW MEXICO,DEPT ELECT & COMP ENGN,ALBUQUERQUE,NM 87131. RI Marchbanks, Richard/I-4410-2013 NR 7 TC 2 Z9 2 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0952-1976 J9 ENG APPL ARTIF INTEL JI Eng. Appl. Artif. Intell. PD APR PY 1993 VL 6 IS 2 BP 117 EP 122 DI 10.1016/0952-1976(93)90027-U PG 6 WC Automation & Control Systems; Computer Science, Artificial Intelligence; Engineering, Multidisciplinary; Engineering, Electrical & Electronic SC Automation & Control Systems; Computer Science; Engineering GA KW196 UT WOS:A1993KW19600004 ER PT J AU CUSHMAN, RM STOSS, FW AF CUSHMAN, RM STOSS, FW TI CARBON-DIOXIDE-INFORMATION-ANALYSIS-CENTER SO ENVIRONMENT LA English DT Editorial Material RP CUSHMAN, RM (reprint author), OAK RIDGE NATL LAB,COLL ENVIRONM SCI,CDIAC,OAK RIDGE,TN 37831, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU HELDREF PUBLICATIONS PI WASHINGTON PA 1319 EIGHTEENTH ST NW, WASHINGTON, DC 20036-1802 SN 0013-9157 J9 ENVIRONMENT JI Environment PD APR PY 1993 VL 35 IS 3 BP 5 EP & PG 0 WC Environmental Sciences; Environmental Studies SC Environmental Sciences & Ecology GA KX068 UT WOS:A1993KX06800003 ER PT J AU GOLD, LS MANLEY, NB SLONE, TH GARFINKEL, GB ROHRBACH, L AMES, BN AF GOLD, LS MANLEY, NB SLONE, TH GARFINKEL, GB ROHRBACH, L AMES, BN TI THE 5TH-PLOT OF THE CARCINOGENIC POTENCY DATABASE - RESULTS OF ANIMAL BIOASSAYS PUBLISHED IN THE GENERAL LITERATURE THROUGH 1988 AND BY THE NATIONAL-TOXICOLOGY-PROGRAM THROUGH 1989 SO ENVIRONMENTAL HEALTH PERSPECTIVES LA English DT Article ID SPRAGUE-DAWLEY RATS; MALE F344 RATS; LONG-TERM; TOXICITY CARCINOGENICITY; INHALATION TOXICITY; RODENT CARCINOGENS; DRINKING-WATER; N-NITROSAMINES; CHRONOLOGICAL SUPPLEMENT; BUTYLATED HYDROXYANISOLE AB This paper is the fifth plot of the Carcinogenic Potency Database (CPDB) that first appeared in this journal in 1984 (1-5). We report here results of carcinogenesis bioassays published in the general literature between January 1987 and December 1988, and in technical reports of the National Toxicology Program between July 1987 and December 1989. This supplement includes results, of 412 long-term, chronic experiments of 147 test compounds and reports the same information about each experiment in the same plot format as the earlier papers: the species and strain of test animal, the route and duration of compound administration, dose level and other aspects of experimental protocol, histopathology and tumor incidence, TD50 (carcinogenic potency) and its statistical significance, dose response, author's opinion about carcinogenicity, and literature citation. We refer the reader to the 1984 publications (1,5,6) for a guide to the plot of the database, a complete description of the numerical index of carcinogenic potency, and a discussion of the sources of data, the rationale for the inclusion of particular experiments and particular target sites, and the conventions adopted in summarizing the literature. The rive plots of the database are to be used together, as results of individual experiments that were published earlier are not repeated. In all, the five plots, include results of 4487 experiments on 1136 chemicals. Several analyses based on the CPDB that were published earlier are described briefly, and updated results based on all five plots are given for the following earlier analyses: the most potent TD50 value by species, reproducibility of bioassay results, positivity rates, and prediction between species. A new feature of this supplement is that Appendix 14 now provides a summary compendium of positivity and potency, as well as an index to all chemicals in the five plots of the CPDB. It provides the following summary data for each chemical: (a) whether it has been tested in each sex of rats and mice, and positivity results in each group; (b) for positive chemicals, a summary of carcinogenic potency for rats and for mice; (c) an index to the CPDB sorted by chemical name that reports synonyms, CAS number, and the plot numbers that include experiments on the chemical. For readers using the CPDB more extensively, a combined plot of all results from the five separate plot papers, ordered alphabetically by chemical is available from the first author in printed form or on computer tape or diskette. A SAS database is also available. C1 UNIV CALIF BERKELEY,DIV BIOCHEM & MOLEC BIOL,BERKELEY,CA 94720. RP GOLD, LS (reprint author), LAWRENCE BERKELEY LAB,DIV CELL & MOLEC BIOL,BERKELEY,CA 94720, USA. FU NIEHS NIH HHS [ESO1896] NR 107 TC 106 Z9 107 U1 0 U2 3 PU NATL INST ENVIRON HEALTH SCI PI RES TRIANGLE PK PA PO BOX 12233, RES TRIANGLE PK, NC 27709 SN 0091-6765 J9 ENVIRON HEALTH PERSP JI Environ. Health Perspect. PD APR PY 1993 VL 100 BP 65 EP 168 DI 10.2307/3431522 PG 104 WC Environmental Sciences; Public, Environmental & Occupational Health; Toxicology SC Environmental Sciences & Ecology; Public, Environmental & Occupational Health; Toxicology GA LF734 UT WOS:A1993LF73400008 PM 8354183 ER PT J AU MCCARTHY, JF WILLIAMS, TM LIANG, LY JARDINE, PM JOLLEY, LW TAYLOR, DL PALUMBO, AV COOPER, LW AF MCCARTHY, JF WILLIAMS, TM LIANG, LY JARDINE, PM JOLLEY, LW TAYLOR, DL PALUMBO, AV COOPER, LW TI MOBILITY OF NATURAL ORGANIC-MATTER IN A SANDY AQUIFER SO ENVIRONMENTAL SCIENCE & TECHNOLOGY LA English DT Article ID GRADIENT TRACER EXPERIMENTS; INDIGENOUS BACTERIA; HUMIC SUBSTANCES; ACID TREATMENT; CARBON; TRANSPORT; ADSORPTION; WATER; FRACTIONATION; CONTAMINANTS AB Field-scale transport of natural organic matter (NOM) was studied in a two-well tracer test by injecting 80 000 L of ''brown water'' (66 mg of C L-1) from a wetlands pond into a shallow, sandy, coastal plain aquifer. The basic features of NOM breakthrough observed in laboratory column studies (extending tailing and rapid decline in concentrations when NOM inputs are terminated) were observed in the field. Retardation of NOM in the field agreed with predictions from laboratory studies. In spite of natural heterogeneities, fractionation of NOM subcomponents occurred in transport. Smaller (<3000 MW) and more hydrophilic (by XAD-8 chromatography) components of NOM were more mobile than were larger (3-100K MW), more hydrophobic components. However, over the 2-week injection, the solid and solution phase reached an apparent steady state with respect to NOM adsorption, resulting in the unretarded transport of even the hydrophobic and macromolecular NOM. The results indicate that NOM can exhibit considerable mobility in an aquifer and suggest that NOM could alter the transport of contaminants in groundwater. C1 CLEMSON UNIV,BARUCH FOREST SCI INST,GEORGETOWN,SC 29442. RP MCCARTHY, JF (reprint author), OAK RIDGE NATL LAB,DIV ENVIRONM SCI,OAK RIDGE,TN 37831, USA. RI Palumbo, Anthony/A-4764-2011; Cooper, Lee/E-5251-2012; Liang, Liyuan/O-7213-2014 OI Palumbo, Anthony/0000-0002-1102-3975; Cooper, Lee/0000-0001-7734-8388; Liang, Liyuan/0000-0003-1338-0324 NR 43 TC 95 Z9 107 U1 4 U2 18 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 APR PY 1993 VL 27 IS 4 BP 667 EP 676 DI 10.1021/es00041a010 PG 10 WC Engineering, Environmental; Environmental Sciences SC Engineering; Environmental Sciences & Ecology GA KU952 UT WOS:A1993KU95200020 ER PT J AU NIMIOS, MR JACOBY, WA BLAKE, DM MILNE, TA AF NIMIOS, MR JACOBY, WA BLAKE, DM MILNE, TA TI DIRECT MASS-SPECTROMETRIC STUDIES OF THE DESTRUCTION OF HAZARDOUS WASTES .2. GAS-PHASE PHOTOCATALYTIC OXIDATION OF TRICHLOROETHYLENE OVER TIO2 - PRODUCTS AND MECHANISMS SO ENVIRONMENTAL SCIENCE & TECHNOLOGY LA English DT Article ID MOLECULAR CHARACTERIZATION; TITANIUM-DIOXIDE; PYROLYSIS; BIOMASS AB The gas-phase photocatalytic oxidation of trichloroethylene (TCE) over titanium dioxide was investigated as a potential method for destroying this common pollutant. The results from this study agree with earlier studies in that high levels of destruction of TCE were achieved. Accompanying these high rates of destruction were high quantum yields (approaching unity). However, direct-sampling mass spectrometry and gas-phase Fourier transform infrared (FTIR) spectroscopy revealed that there are significant quantities of byproducts produced [phosgene, dichloroacetyl chloride (DCAC), carbon monoxide, molecular chlorine]. The DCAC has been rationalized on the basis of a chemical reaction mechanism in which the TCE molecules are oxidized in a chain reaction involving Cl atoms. This mechanism appears to be validated by tests with other chlorinated ethylenes (perchloroethylene, dichloroethylenes). Phosgene may arise at least partially from the photocatalytic oxidation of DCAC, and molecular chlorine may result from the recombination of chlorine atoms. The results of this study are discussed relative to aqueous-phase photocatalytic oxidation of TCE where chlorinated intermediates have been observed. RP NIMIOS, MR (reprint author), NATL RENEWABLE ENERGY LAB,GOLDEN,CO 80401, USA. NR 26 TC 11 Z9 12 U1 0 U2 1 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 APR PY 1993 VL 27 IS 4 BP 732 EP 740 PG 9 WC Engineering, Environmental; Environmental Sciences SC Engineering; Environmental Sciences & Ecology GA KU952 UT WOS:A1993KU95200028 ER PT J AU LEE, YN ZHOU, XL AF LEE, YN ZHOU, XL TI METHOD FOR THE DETERMINATION OF SOME SOLUBLE ATMOSPHERIC CARBONYL-COMPOUNDS SO ENVIRONMENTAL SCIENCE & TECHNOLOGY LA English DT Article ID LIQUID-CHROMATOGRAPHY; HYDROGEN-PEROXIDE; AIR; ALDEHYDES; FORMALDEHYDE; HYDROPEROXIDES; HYDROCARBONS; EQUILIBRIUM; CHEMISTRY; CONSTANTS AB A technique was developed for the measurement of soluble atmospheric carbonyl compounds, which uses a pyrex coil gas-liquid scrubber sampler in conjunction with a high-performance liquid chromatograph (HPLC) equipped with a UV-visible detector for separation and identification following derivatization with 2,4-dinitrophenylhydrazine (DNPH). Carbonyls exhibiting a Henry's law solubility similar to or greater than that of formaldehyde (FA) can be determined by this method; these include FA, glycolaldehyde (GA), glyoxal (GL), and methylglyoxal (MG). The typical sampling and analysis conditions are as follows: gas and liquid flow rates through the coil 2.3 L min-1 and 0.30 mL min-1, respectively; derivatization time 4 h at [DNPH] = 0.10 mM and pH 2.4; HPLC sample injection volume 1.2 mL; 6-mm path-length flow cell (360 nm for FA and GA; 400 nm for GL and MG). Based on liquid standards and field-developed chromatographic characteristics, the limits of detection are approximately 0.005 ppb (in the gas phase) for MG, approximately 0.01 ppb for GL, and approximately 0.02 ppb for FA and GA. Because of the short air-liquid contact time in the coil sampler (less-than-or-equal-to 10 s), interferences from aqueous-phase reactions of O3 are insignificant. Also, at the low pH of the scrubbing solution, interference resulting from reactions of carbonyls with S(IV) is unimportant. A number of other potential interferences were examined and found to be unimportant. This technique was employed in a field measurement at a rural site in Georgia as part of the Southern Oxidants Study in summer 1991. The concentrations of FA, GA, GL, and MG observed ranged up to 8, 0.6, 0.1, and 0.2 ppb, respectively. RP LEE, YN (reprint author), BROOKHAVEN NATL LAB,DIV ENVIRONM CHEM,DEPT APPL SCI,UPTON,NY 11973, USA. NR 43 TC 58 Z9 59 U1 1 U2 11 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 APR PY 1993 VL 27 IS 4 BP 749 EP 756 DI 10.1021/es00041a020 PG 8 WC Engineering, Environmental; Environmental Sciences SC Engineering; Environmental Sciences & Ecology GA KU952 UT WOS:A1993KU95200030 ER PT J AU CHOI, Y BRUNKEN, RC HAWKINS, RA HUANG, SC BUXTON, DB HOH, CK PHELPS, ME SCHELBERT, HR AF CHOI, Y BRUNKEN, RC HAWKINS, RA HUANG, SC BUXTON, DB HOH, CK PHELPS, ME SCHELBERT, HR TI FACTORS AFFECTING MYOCARDIAL 2-[F-18]FLUORO-2-DEOXY-D-GLUCOSE UPTAKE IN POSITRON EMISSION TOMOGRAPHY STUDIES OF NORMAL HUMANS SO EUROPEAN JOURNAL OF NUCLEAR MEDICINE LA English DT Article DE POSITRON EMISSION TOMOGRAPHY; MYOCARDIAL GLUCOSE UTILIZATION RATES; GLUCOSE; INSULIN; FREE FATTY ACIDS; GLUCAGON ID GLUCOSE METABOLIC-RATE; ORAL GLUCOSE; LUMPED CONSTANT; GROWTH-HORMONE; WALL-MOTION; CARDIAC PET; FLUORINE-18-DEOXYGLUCOSE; COUNTERREGULATION; QUANTIFICATION; DISAPPEARANCE AB The goal of this study was to identify the anatomic and physiologic factors affecting left ventricular myocardial 2-[F-18]fluoro-2-deoXy-D-glucose (FDG) uptake and myocardial glucose utilization rates (MRGlc) in normal humans. Eighteen healthy male volunteers were studied in the fasting state (4-19 h) and 16 after oral glucose loading (100 g dextrose) with positron emission tomography (PET) and FDG. Substrate and hormone concentrations were measured in each study. The kinetics of myocardial FDG uptake were evaluated using both a three-compartment model and Patlak graphical analysis. Systolic blood pressures and rate pressure products were similar in the fasting and postglucose states. MRGlc averaged 0.24 +/- 0.17 mumol/min/g in fasting subjects and rose to 0.69 +/- 0.11 mumol/min/g after glucose loading. Phosphorylation rate constant, k3, and MRGlc were linearly related (P < 0.001). Increases in MRGlc following glucose loading were correlated with plasma glucose, insulin and free fatty acid concentrations, ratios of insulin to glucagon levels, and influx rate constants of FDG. Glucose loading improved the diagnostic image quality due to more rapid clearance of tracer from blood and higher myocardial FDG uptake. When MRG1c, glucose and insulin concentrations, and insulin to glucagon ratios exceeded 0.2 mumol/min/g, 100 mg/dl, 19 muU/ml, and 0.2 muU/pg, respectively, myocardial uptake of FDG was always adequate for diagnostic use. FDG image quality and MRG1c were similar after relatively short (6 +/- 2 h) and overnight (16 +/- 2 h) fasting. Significant (P < 0.05) regional heterogeneity of myocardial FDG uptake and MRG1c was observed in both the fasting and the postglucose studies. MRG1c and FDG uptake values in the posterolateral wall were higher than those in the anterior wall and septum. Thus, both 6-h and overnight fasts resulted in similarly low myocardial glucose utilization rates. While MRG1c and myocardial FDG uptake depended on plasma glucose, free fatty acid, and insulin concentrations, the results also suggest an additional dependency on plasma glucagon levels. Regional heterogeneities in myocardial FDG uptake and MRG1c are evident and independent of the subjects' dietary state. These regional heterogeneities need to be considered in studies of patients with cardiac disease. C1 UNIV CALIF LOS ANGELES,SCH MED,BIOMED & ENVIRONM SCI LAB,LOS ANGELES,CA 90024. UNIV CALIF LOS ANGELES,SCH MED,CRUMP INST BIOL IMAGING,LOS ANGELES,CA 90024. RP CHOI, Y (reprint author), UNIV CALIF LOS ANGELES,SCH MED,DEPT RADIOL SCI,DIV NUCL MED & BIOPHYS,DOE,NUCL MED LAB,LOS ANGELES,CA 90024, USA. OI Buxton, Denis/0000-0003-3077-6435 FU NHLBI NIH HHS [HL 29845, HL 33177, HL 02202-4] NR 39 TC 70 Z9 70 U1 0 U2 3 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 SN 0340-6997 J9 EUR J NUCL MED JI Eur. J. Nucl. Med. PD APR PY 1993 VL 20 IS 4 BP 308 EP 318 PG 11 WC Radiology, Nuclear Medicine & Medical Imaging SC Radiology, Nuclear Medicine & Medical Imaging GA KW326 UT WOS:A1993KW32600006 PM 8491223 ER PT J AU MOORE, KL MEHLHORN, RJ AF MOORE, KL MEHLHORN, RJ TI CYTOSTATIC EFFECTS OF HORSERADISH AND THYROID PEROXIDASE DERIVED FREE-RADICALS SO FREE RADICAL BIOLOGY AND MEDICINE LA English DT Article DE CHO CELLS; CYTOSTATIC EFFECT; FREE RADICALS; PEROXIDASE (HORSERADISH AND THYROID); H2O2; TISSUE CULTURE; ESR ID MOUSE EPIDERMAL-CELLS; HUMAN MYELOPEROXIDASE; HYDROGEN-PEROXIDE; COMPOUND-II; GENERATION; DNA; LACTOPEROXIDASE; ACTIVATION; METABOLISM; ENZYME AB An otherwise noncytostatic flux of H2O2 from glucose and glucose oxidase became cytostatic to cultured Chinese Hamster Ovary (CHO) cells when horseradish or thyroid peroxidase was added to the culture medium. Electron spin resonance (ESR) measurements showed that one or more factors present in the culture medium promote the one-electron oxidation of a reduced nitroxide or glutathione in an H2O2/peroxidase-dependent process. Moreover, a reduced nitroxide conferred significant protection against the cytostatic effect of H2O2/peroxidase. Cytostatic effects were not only seen in the presence of the active H2O2/peroxidase system, but also in media which had been preexposed to H2O2/peroxidase but no longer contained an active H2O2 generating system. It is suggested that peroxidases oxidize one or more factors in tissue culture media to free radicals, which react with nearby components of cells or form toxic products, causing growth inhibition. If similar free radical precursors are present in tissue fluids, some of the toxicity of H2O2 in vivo may be due to peroxidase-mediated endogenous free radical generation. C1 LAWRENCE BERKELEY LAB,DIV ENERGY & ENVIRONM,MS 70-193A,1 CYCLOTRON RD,BERKELEY,CA 94720. UNIV CALIF BERKELEY,ENDOCRINOL GRP,BERKELEY,CA 94720. FU NIA NIH HHS [AG04818] NR 38 TC 9 Z9 10 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0891-5849 J9 FREE RADICAL BIO MED JI Free Radic. Biol. Med. PD APR PY 1993 VL 14 IS 4 BP 371 EP 379 DI 10.1016/0891-5849(93)90086-A PG 9 WC Biochemistry & Molecular Biology; Endocrinology & Metabolism SC Biochemistry & Molecular Biology; Endocrinology & Metabolism GA KR937 UT WOS:A1993KR93700003 PM 8468022 ER PT J AU OH, MS FOSTER, KG ALCARAZ, A CRAWFORD, RW TAYLOR, RW COBURN, TT AF OH, MS FOSTER, KG ALCARAZ, A CRAWFORD, RW TAYLOR, RW COBURN, TT TI THERMAL-DECOMPOSITION OF BUDDINGTONITE IN OIL SHALES SO FUEL LA English DT Article DE DECOMPOSITION; OIL SHALE; NITROGEN ID PYROLYSIS; AMMONIA AB Thermal decomposition of buddingtonite, an ammonium feldspar found in Green River Formation oil shales, was studied in order to determine its contribution to the total nitrogen released from oil shales. In an inert gas sweep, ammonia from buddingtonite evolves at temperatures between 400 and 900-degrees-C. Ammonia also decomposes to form N2 and H-2 in the same temperature range. The water evolution profile consists of several peaks. The water peak,which is associated with buddingtonite decomposition, occurs at the same temperatures as the nitrogen species evolution. The X-ray diffraction spectra show that solid products from decomposition are mainly quartz, with some potassium feldspar and mullite. Kinetic parameters for buddingtonite decomposition were derived from the total nitrogen evolution data. Pyrolysis of an ashed Green River Formation oil shale shows that buddingtonite in oil shale also decomposes at the same temperature range as the museum-grade buddingtonite. During oil shale processing, buddingtonite generates ammonia during combustion. Some of this ammonia is burned, yielding NO(x), and some remains in the flue gas. This has implications for NO(x) control during retorted shale combustion. C1 LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550. RP OH, MS (reprint author), TEXACO USA INC,POB 509,BEACON,NY 12508, USA. NR 20 TC 7 Z9 7 U1 0 U2 2 PU BUTTERWORTH-HEINEMANN LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, OXON, ENGLAND OX5 1GB SN 0016-2361 J9 FUEL JI Fuel PD APR PY 1993 VL 72 IS 4 BP 517 EP 523 DI 10.1016/0016-2361(93)90111-E PG 7 WC Energy & Fuels; Engineering, Chemical SC Energy & Fuels; Engineering GA KR171 UT WOS:A1993KR17100007 ER PT J AU LOGAN, BG AF LOGAN, BG TI ON THE UTILITY OF TOKAMAKS FOR ENERGY SO FUSION ENGINEERING AND DESIGN LA English DT Editorial Material RP LOGAN, BG (reprint author), LAWRENCE LIVERMORE NATL LAB,POB 808,LIVERMORE,CA 94550, USA. NR 12 TC 0 Z9 0 U1 0 U2 0 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE 1 PA PO BOX 564, 1001 LAUSANNE 1, SWITZERLAND SN 0920-3796 J9 FUSION ENG DES JI Fusion Eng. Des. PD APR PY 1993 VL 22 IS 3 BP 145 EP 149 PG 5 WC Nuclear Science & Technology SC Nuclear Science & Technology GA LG348 UT WOS:A1993LG34800001 ER PT J AU LOGAN, BG AF LOGAN, BG TI INERTIAL FUSION-REACTORS USING COMPACT FUSION ADVANCED RANKINE (CFARII) MHD CONVERSION SO FUSION ENGINEERING AND DESIGN LA English DT Article AB This study evaluates the potential performance (efficiency and cost) of inertial fusion reactors assumed capable of vaporizing blankets of various working materials to a temperature (10,000-20,000 K) suitable for economical MHD conversion in a Compact Fusion Advanced Rankine II (CFARII) power cycle. Using a conservative model, 1-D neutronics calculations of the fraction of fusion yield captured as a function of the blanket thickness of Flibe, lithium and lead-lithium blankets are used to determine the optimum blanket thicknesses for each material to minimize CoE for various assumed fusion yields, ''generic'' driver costs, and target gains. Lithium-hydride blankets are also evaluated using an extended neutronics model. Generally optimistic (''advanced'') combinations of lower driver cost/joule and higher target gain are assumed to allow high enough fusion yields to vaporize and ionize target blankets thick enough to stop most 14 MeV neutrons, and to breed tritium. A novel magnetized, prestressed reactor chamber concept is modeled together with previously developed models for the CFARII Balance-of-Plant (BoP), consisting of a supersonic plasma jet, MHD generator, and ''raindrop'' condensor. High fusion yields (20 to 80 GJ) are found necessary to heat and ionize the Flibe, lithium, and lead-lithium blankets for MHD conversion, with initial solid thicknesses sufficient to capture most of the fusion yield. Much smaller fusion yields (1 to 20 GJ) are required for lithium-hydride blankets. For Flibe, lithium, and lead-lithium blankets, improvements in target gain and/or driver cost/joule, characterized by a ''Bang per Buck'' figure-of-merit of greater than or similar to 20 joules yield per driver $, would be required for competitive CoE, while a figure-of-merit of greater than or similar to 1 joule yield per driver $ would suffice for lithium-hydride blankets. Advances in targets/driver costs would benefit any IFE reactor, but the very low CFARII BoP costs (contributing only 3 mill$/kWh to CoE) allows this type of reactor, given sufficient advances that non-driver costs dominate, to ultimately produce electricity at a much lower cost than any current nuclear plant. RP LOGAN, BG (reprint author), LAWRENCE LIVERMORE NATL LAB,LAWRENCE LIVERMORE NATL LAB,POB 808,L-640,LIVERMORE,CA 94551, USA. NR 28 TC 11 Z9 11 U1 0 U2 1 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE 1 PA PO BOX 564, 1001 LAUSANNE 1, SWITZERLAND SN 0920-3796 J9 FUSION ENG DES JI Fusion Eng. Des. PD APR PY 1993 VL 22 IS 3 BP 151 EP 192 PG 42 WC Nuclear Science & Technology SC Nuclear Science & Technology GA LG348 UT WOS:A1993LG34800002 ER PT J AU PANJEHPOUR, M OVERHOLT, BF VODINH, T FARRIS, C SNEED, R AF PANJEHPOUR, M OVERHOLT, BF VODINH, T FARRIS, C SNEED, R TI FLUORESCENCE SPECTROSCOPY FOR DETECTION OF MALIGNANT-TISSUE IN THE ESOPHAGUS SO GASTROENTEROLOGY LA English DT Meeting Abstract C1 THOMPSON CANC SURV CTR,KNOXVILLE,TN. OAK RIDGE NATL LAB,OAK RIDGE,TN 37831. NR 0 TC 6 Z9 6 U1 0 U2 1 PU W B SAUNDERS CO PI PHILADELPHIA PA INDEPENDENCE SQUARE WEST CURTIS CENTER, STE 300, PHILADELPHIA, PA 19106-3399 SN 0016-5085 J9 GASTROENTEROLOGY JI Gastroenterology PD APR PY 1993 VL 104 IS 4 SU S BP A439 EP A439 PG 1 WC Gastroenterology & Hepatology SC Gastroenterology & Hepatology GA KX957 UT WOS:A1993KX95701742 ER PT J AU MA, C MARTIN, S TRASK, B HAMLIN, JL AF MA, C MARTIN, S TRASK, B HAMLIN, JL TI SISTER CHROMATID FUSION INITIATES AMPLIFICATION OF THE DIHYDROFOLATE-REDUCTASE GENE IN CHINESE-HAMSTER CELLS SO GENES & DEVELOPMENT LA English DT Article DE DHFR GENE; GENE AMPLIFICATION; CHO CELLS; SISTER CHROMATID FUSION; BRIDGE BREAKAGE FUSION ID METHOTREXATE-RESISTANT CELLS; LARGE INVERTED DUPLICATIONS; DNA AMPLIFICATION; LINES RESISTANT; MAMMALIAN-CELLS; AMPLIFIED DNA; SEQUENCES; AMPLICONS; CANCER; N-(PHOSPHONACETYL)-L-ASPARTATE AB We have utilized a dihydrofolate reductase (DHFR) probe in combination with selected probes from other positions along the 2q chromosome arm in a two-color fluorescence in situ hybridization analysis of early DHFR gene amplification events in CHO cells. These studies show clearly that the most frequent initiating event is the formation of a giant inverted duplication, resulting either from chromosome breakage and terminal fusion or a reverse unequal sister chromatid exchange. The dicentric chromosomes thus formed initiate bridge/breakage/fusion cycles that appear to mediate subsequent amplification steps to higher copy C1 UNIV VIRGINIA, SCH MED, DEPT BIOCHEM, CHARLOTTESVILLE, VA 22908 USA. UNIV VIRGINIA, SCH MED, CELL & MOLEC BIOL PROGRAM, CHARLOTTESVILLE, VA 22908 USA. LAWRENCE LIVERMORE NATL LAB, DIV BIOMED SCI, LIVERMORE, CA 94550 USA. NR 54 TC 164 Z9 168 U1 0 U2 4 PU COLD SPRING HARBOR LAB PRESS, PUBLICATIONS DEPT PI COLD SPRING HARBOR PA 1 BUNGTOWN RD, COLD SPRING HARBOR, NY 11724 USA SN 0890-9369 EI 1549-5477 J9 GENE DEV JI Genes Dev. PD APR PY 1993 VL 7 IS 4 BP 605 EP 620 DI 10.1101/gad.7.4.605 PG 16 WC Cell Biology; Developmental Biology; Genetics & Heredity SC Cell Biology; Developmental Biology; Genetics & Heredity GA KW758 UT WOS:A1993KW75800008 PM 8458577 ER PT J AU OSTRANDER, EA SPRAGUE, GF RINE, J AF OSTRANDER, EA SPRAGUE, GF RINE, J TI IDENTIFICATION AND CHARACTERIZATION OF DINUCLEOTIDE REPEAT (CA)N MARKERS FOR GENETIC-MAPPING IN DOG SO GENOMICS LA English DT Article ID MAJOR HISTOCOMPATIBILITY COMPLEX; MOUSE GENOME; MAMMALIAN GENOMES; DNA; MICROSATELLITES; SEQUENCES; POLYMORPHISMS; EVOLUTION C1 UNIV CALIF BERKELEY,DEPT MOLEC & CELLULAR BIOL,401 BARKER HALL,BERKELEY,CA 94720. LAWRENCE BERKELEY LAB,CTR HUMAN GENOME,BERKELEY,CA 94720. UNIV OREGON,INST MOLEC BIOL,EUGENE,OR 97403. OI Ostrander, Elaine/0000-0001-6075-9738 FU NIGMS NIH HHS [GM30027] NR 27 TC 276 Z9 283 U1 5 U2 29 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 APR PY 1993 VL 16 IS 1 BP 207 EP 213 DI 10.1006/geno.1993.1160 PG 7 WC Biotechnology & Applied Microbiology; Genetics & Heredity SC Biotechnology & Applied Microbiology; Genetics & Heredity GA KW205 UT WOS:A1993KW20500028 PM 8486359 ER PT J AU GLESNE, D COLLART, F VARKONY, T DRABKIN, H HUBERMAN, E AF GLESNE, D COLLART, F VARKONY, T DRABKIN, H HUBERMAN, E TI CHROMOSOMAL LOCALIZATION AND STRUCTURE OF THE HUMAN TYPE-II IMP DEHYDROGENASE GENE (IMPDH2) SO GENOMICS LA English DT Note ID EXPRESSION; INDUCTION; CDNAS; CELLS C1 UNIV CHICAGO,DEPT MOLEC GENET & CELL BIOL,CHICAGO,IL 60637. ARGONNE NATL LAB,DIV BIOL & MED RES,ARGONNE,IL 60439. UNIV COLORADO,HLTH SCI CTR,DIV MED ONCOL,DENVER,CO 80262. FU NHGRI NIH HHS [HG00358] NR 14 TC 21 Z9 22 U1 1 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 APR PY 1993 VL 16 IS 1 BP 274 EP 277 DI 10.1006/geno.1993.1177 PG 4 WC Biotechnology & Applied Microbiology; Genetics & Heredity SC Biotechnology & Applied Microbiology; Genetics & Heredity GA KW205 UT WOS:A1993KW20500045 PM 8098009 ER PT J AU ENGLE, ML BURKS, C AF ENGLE, ML BURKS, C TI ARTIFICIALLY GENERATED DATA SETS FOR TESTING DNA-SEQUENCE ASSEMBLY ALGORITHMS SO GENOMICS LA English DT Note C1 LOS ALAMOS NATL LAB,THEORET BIOL & BIOPHYS GRP,T-10,MS K710,LOS ALAMOS,NM 87545. LOS ALAMOS NATL LAB,CTR HUMAN GENOME STUDIES,LOS ALAMOS,NM 87545. NR 13 TC 31 Z9 31 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 APR PY 1993 VL 16 IS 1 BP 286 EP 288 DI 10.1006/geno.1993.1180 PG 3 WC Biotechnology & Applied Microbiology; Genetics & Heredity SC Biotechnology & Applied Microbiology; Genetics & Heredity GA KW205 UT WOS:A1993KW20500048 PM 8486376 ER PT J AU PALMER, DA HYDE, KE AF PALMER, DA HYDE, KE TI AN EXPERIMENTAL-DETERMINATION OF FERROUS CHLORIDE AND ACETATE COMPLEXATION IN AQUEOUS-SOLUTIONS TO 300-DEGREES-C SO GEOCHIMICA ET COSMOCHIMICA ACTA LA English DT Article ID HYDROTHERMAL SOLUTIONS; POTENTIOMETRIC DETERMINATION; SOLUBILITY; CONSTANTS; ELECTROLYTES; MAGNETITE; PYRITE; MEDIA; ACID AB The formation of the monochloroiron(II) complex, FeCl+, was studied potentiometrically from 125 to 295-degrees-C at 25 degree intervals at one molal ionic strength in aqueous solutions containing acetic acid, sodium acetate, and sodium trifluoromethanesulfonate. In this method, competition between chloride and acetate ions for the ferrous cation resulted in a change in solution pH, which in turn was monitored in situ in a hydrogen-electrode, concentration cell. A simple empirical approach was used to extrapolate these formation quotients to infinite dilution. The resulting constants proved to be in excellent agreement with previous spectrophotometric results obtained from 25 to 200-degrees-C. Thus, the present study confirms the validity of the conclusions made based on these earlier data concerning the solubility of Fe-containing minerals in hydrothermal brines. Formation constants at infinite dilution for FeCl+ are compared with the stability of ferrous acetate and hydroxide complexes. The original potentiometric titration data for ferrous acetate complex formation were combined in a new fit with values determined from the present study at unit ionic strength. Two empirical treatments (namely the isocoulombic method and the temperature/water density function) were considered for fitting and extrapolating the infinite dilution formation constants to 350-degrees-C. C1 SUNY COLL OSWEGO,DEPT CHEM,OSWEGO,NY 13126. RP PALMER, DA (reprint author), OAK RIDGE NATL LAB,DIV CHEM,BLDG 45005,OAK RIDGE,TN 37831, USA. NR 40 TC 44 Z9 44 U1 0 U2 6 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 APR PY 1993 VL 57 IS 7 BP 1393 EP 1408 DI 10.1016/0016-7037(93)90001-D PG 16 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA KY313 UT WOS:A1993KY31300001 ER PT J AU VAIRAVAMURTHY, A MANOWITZ, B LUTHER, GW JEON, Y AF VAIRAVAMURTHY, A MANOWITZ, B LUTHER, GW JEON, Y TI OXIDATION-STATE OF SULFUR IN THIOSULFATE AND IMPLICATIONS FOR ANAEROBIC ENERGY-METABOLISM SO GEOCHIMICA ET COSMOCHIMICA ACTA LA English DT Letter ID X-RAY ABSORPTION; NEAR-EDGE STRUCTURE; STRUCTURE SPECTROSCOPY; FINE-STRUCTURE; FERMENTATION; SEDIMENTS; BACTERIA; SULFATE; CYCLE AB Disproportionation of thiosulfate is an important pathway in bacterial energy metabolism in anoxic sediments. It has been described as an inorganic fermentation process in which a part of the molecule is oxidized to sulfate, while the other stoichiometrically equivalent part is used as electron acceptor and reduced to sulfide. However, an intramolecular redox change is difficult to envisage because, according to the currently held view, the two sulfur atoms of thiosulfate exist in the oxidation state of sulfate (+6) and sulfide (-2) and do not change their respective oxidation states upon disproportionation. Our results based on XANES spectroscopy indicate that the two different sulfur atoms in thiosulfate have charge densities corresponding to +5 and -1 oxidation states which support a redox mechanism in the disproportionation of thiosulfate to sulfate and sulfide. C1 UNIV DELAWARE, COLL MARINE STUDIES, LEWES, DE 19958 USA. RP VAIRAVAMURTHY, A (reprint author), BROOKHAVEN NATL LAB, DEPT APPL SCI, GEOSCI PROGRAM, UPTON, NY 11973 USA. RI Luther, III, George/A-6384-2008 OI Luther, III, George/0000-0002-0780-885X NR 20 TC 70 Z9 70 U1 0 U2 11 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0016-7037 EI 1872-9533 J9 GEOCHIM COSMOCHIM AC JI Geochim. Cosmochim. Acta PD APR PY 1993 VL 57 IS 7 BP 1619 EP 1623 DI 10.1016/0016-7037(93)90020-W PG 5 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA KY313 UT WOS:A1993KY31300020 ER PT J AU ANDERKO, A PITZER, KS AF ANDERKO, A PITZER, KS TI EQUATION-OF-STATE REPRESENTATION OF PHASE-EQUILIBRIA AND VOLUMETRIC PROPERTIES OF THE SYSTEM NACL-H2O ABOVE 573-K SO GEOCHIMICA ET COSMOCHIMICA ACTA LA English DT Article ID AQUEOUS SODIUM-CHLORIDE; THERMODYNAMIC PERTURBATION-THEORY; SYNTHETIC FLUID INCLUSIONS; DIPOLAR HARD SPHERES; SIMPLE POLAR FLUIDS; CRITICAL-TEMPERATURE; 1500 BARS; MIXTURES; 300-DEGREES-C; 500-DEGREES-C AB A comprehensive equation of state has been developed for the system NaCl-H2O at high temperatures and pressures. The equation consists of a reference part and a perturbation contribution. The reference part represents the properties of a mixture of hard-sphere ion pairs and dipolar solvent molecules. The perturbation part arises from all other interactions and comprises a virial-type expansion truncated after the fifth virial coefficient. Mixing rules for the perturbation part are guided by the composition dependence of virial coefficients and contain empirically determined terms for unlike-molecule interactions. The equation has been fitted to extensive experimental data in the temperature range 573-773 K and to more limited data above 773 K. In both temperature regions, the equation reproduces vapor-liquid equilibria, volumetric properties, and solubilities of solid NaCl essentially within experimental uncertainty. It is valid at temperatures between 573 K and ca. 1200 K and pressures up to 5 kbar. C1 LAWRENCE BERKELEY LAB,BERKELEY,CA 94720. RP ANDERKO, A (reprint author), UNIV CALIF BERKELEY,DEPT CHEM,BERKELEY,CA 94720, USA. OI Anderko, Andrzej/0000-0002-1522-4889 NR 47 TC 235 Z9 246 U1 6 U2 25 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 APR PY 1993 VL 57 IS 8 BP 1657 EP 1680 DI 10.1016/0016-7037(93)90105-6 PG 24 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA LA664 UT WOS:A1993LA66400002 ER PT J AU MCKEAN, JA DIETRICH, WE FINKEL, RC SOUTHON, JR CAFFEE, MW AF MCKEAN, JA DIETRICH, WE FINKEL, RC SOUTHON, JR CAFFEE, MW TI QUANTIFICATION OF SOIL PRODUCTION AND DOWNSLOPE CREEP RATES FROM COSMOGENIC BE-10 ACCUMULATIONS ON A HILLSLOPE PROFILE SO GEOLOGY LA English DT Article ID CALIFORNIA AB Average soil transport rates over a period of approximately 3500 yr on a convex soil-mantled hillslope have been quantified using a mass-balance model that incorporates the soil concentration of the cosmogenic isotope Be-10. The Be-10 model results support the assumption used in most geomorphic models that the soil creep rate is proportional to surface gradient. The predicted diffusion coefficient is 360 +/- 55 cm3 . yr-1 . cm-1 contour length and the average rate of soil production is 0.026 +/- 0.007 cm/yr. Within the uncertainty of this technique, the data do not reject G. K. Gilbert's hypothesis that some hillslopes may exist in a condition of dynamic equilibrium with a uniform soil production rate. However, the model does not require an assumption of dynamic equilibrium and may be an approach that uniquely allows the quantification of a local soil-production rate law. C1 LAWRENCE LIVERMORE NATL LAB,CTR ACCELERATOR MASS SPECTROMETRY,LIVERMORE,CA 94550. RP MCKEAN, JA (reprint author), UNIV CALIF BERKELEY,DEPT GEOL & GEOPHYS,BERKELEY,CA 94720, USA. RI McKean, Jim/C-3581-2011; Caffee, Marc/K-7025-2015 OI Caffee, Marc/0000-0002-6846-8967 NR 14 TC 130 Z9 132 U1 4 U2 23 PU GEOLOGICAL SOC AMERICA PI BOULDER PA PO BOX 9140 3300 PENROSE PLACE, BOULDER, CO 80301 SN 0091-7613 J9 GEOLOGY JI Geology PD APR PY 1993 VL 21 IS 4 BP 343 EP 346 DI 10.1130/0091-7613(1993)021<0343:QOSPAD>2.3.CO;2 PG 4 WC Geology SC Geology GA KW845 UT WOS:A1993KW84500014 ER PT J AU FREDRICKSON, JK BROCKMAN, FJ BJORNSTAD, BN LONG, PE LI, SW MCKINLEY, JP WRIGHT, JV CONCA, JL KIEFT, TL BALKWILL, DL AF FREDRICKSON, JK BROCKMAN, FJ BJORNSTAD, BN LONG, PE LI, SW MCKINLEY, JP WRIGHT, JV CONCA, JL KIEFT, TL BALKWILL, DL TI MICROBIOLOGICAL CHARACTERISTICS OF PRISTINE AND CONTAMINATED DEEP VADOSE SEDIMENTS FROM AN ARID REGION SO GEOMICROBIOLOGY JOURNAL LA English DT Article DE VADOSE ZONE; PALEOSOL; RECHARGE; UNSATURATED FLOW; HYDRAULIC CONDUCTIVITY; HETEROTROPHIC BACTERIA; SURVIVAL ID COASTAL-PLAIN; PHYSIOLOGICAL DIVERSITY; SUBSURFACE SEDIMENTS; BACTERIA; POTENTIALS; AQUIFERS; SOILS; SITE AB The unsaturated (vadose) zone in arid and semiarid regions can be >100 m thick and may receive little or no moisture recharge from the surface. The microbiological properties of the vadose zone are of interest because of the potential for microorganisms to impact the fate and transport of contaminants in these environments. At numerous sites in the western United States, large volumes of wastewater or process water have been disposed of directly to the surface or shallow subsurface and have subsequently migrated through the vadose zone to the groundwater. The purpose of this study was to determine and compare the microbial properties of pristine and impacted vadose zone sediments. Vadose zone sediments from depths ranging from 24 to 90 m were obtained from 3 bore-holes drilled on the Hanford site in south-central Washington State. One bore-hole was located in a pristine area and the other two were located in areas where wastewater had been disposed of directly to the surface and near subsurface. An open-flow centrifugation method was used to determine unsaturated hydraulic conductivity for the sediments, allowing construction of characteristic curves relating the hydraulic conductivity (K) to the volumetric water content (theta). By comparing the volumetric water content of sediments obtained prior to centrifugation to their water content over a range of K(theta), it could be determined which vadose zone samples had been subjected to artificial recharge. Elevated concentrations of nitrate and the presence of carbon tetrachloride in vadose sediments were also used as indicators that sediments had been impacted by past waste disposal practices. Those vadose zone paleosol samples receiving artificial recharge had higher populations of culturable bacteria (log 1.0-6.6 CFU g-1) and were able to mineralize organic substrates more rapidly than a pristine paleosol. Thus, the in situ microbial population was stimulated by increased moisture from artificial recharge and/or from contaminants. In contrast, culturable bacteria were near or below detection in unimpacted fluvial and flood sands. The few culturable microorganisms that were present in unimpacted vadose sediments were either associated with the sediments at the time of deposition or transported from the surface during the last major proglacial flood, approximately 13,000 years ago. C1 WASHINGTON STATE UNIV, RICHLAND, WA USA. NEW MEXICO INST MIN & TECHNOL, SOCORRO, NM 87801 USA. FLORIDA STATE UNIV, TALLAHASSEE, FL 32306 USA. RP FREDRICKSON, JK (reprint author), PACIFIC NW LAB, K4-06, POB 999, RICHLAND, WA 99352 USA. RI Long, Philip/F-5728-2013 OI Long, Philip/0000-0003-4152-5682 NR 28 TC 30 Z9 31 U1 0 U2 3 PU TAYLOR & FRANCIS PI BRISTOL PA 1900 FROST ROAD, SUITE 101, BRISTOL, PA 19007-1598 SN 0149-0451 J9 GEOMICROBIOL J JI Geomicrobiol. J. PD APR-JUN PY 1993 VL 11 IS 2 BP 95 EP 107 PG 13 WC Environmental Sciences; Geosciences, Multidisciplinary SC Environmental Sciences & Ecology; Geology GA NG198 UT WOS:A1993NG19800004 ER PT J AU BOWER, NW LEWIS, CM GALBRAITH, JM LUEDEMANN, G AF BOWER, NW LEWIS, CM GALBRAITH, JM LUEDEMANN, G TI ELEMENTAL CONCENTRATIONS OF CHINESE ROCK STANDARDS GSR 1-6 - A COMPARISON WITH THE CERTIFICATE VALUES SO GEOSTANDARDS NEWSLETTER LA English DT Article ID GEOCHEMICAL REFERENCE-STANDARDS; SPECTROPHOTOMETRIC DETERMINATION; FERROUS IRON AB Data are presented for the six new Chinese rock standards, GSR 1 through 6. These samples include a granite, an andesite, a basalt, a sandstone, a shale, and a limestone, providing a wide range of sample types of geochemical interest. The certificate values were tested using XRF and ITNA for the major and trace elements and colorimetry, coulometry, and thermogravimetry for the ferrous iron and the volatile constitutents. Excellent agreement was obtained for the 50 elements measured, implying these standards have been well characterized generally and should be of immediate use to geochemists. C1 LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545. RP BOWER, NW (reprint author), COLORADO COLL,DEPT CHEM,COLORADO SPRINGS,CO 80903, USA. NR 7 TC 2 Z9 3 U1 0 U2 2 PU GEOSTANDARDS PI VANDOEUVRE NANCY PA 15 RUE NOTRE-DAME-DES-PAUVRES BP 20, 54501 VANDOEUVRE NANCY, FRANCE SN 0150-5505 J9 GEOSTANDARD NEWSLETT JI Geostand. Newsl. PD APR PY 1993 VL 17 IS 1 BP 117 EP 121 DI 10.1111/j.1751-908X.1993.tb00126.x PG 5 WC Geosciences, Multidisciplinary SC Geology GA KX906 UT WOS:A1993KX90600007 ER PT J AU MAHAFFEY, JA PARKHURST, MA JAMES, AC CROSS, FT ALAVANJA, MCR BOICE, JD EZRINE, S HENDERSON, P BROWNSON, RC AF MAHAFFEY, JA PARKHURST, MA JAMES, AC CROSS, FT ALAVANJA, MCR BOICE, JD EZRINE, S HENDERSON, P BROWNSON, RC TI ESTIMATING PAST EXPOSURE TO INDOOR RADON FROM HOUSEHOLD GLASS SO HEALTH PHYSICS LA English DT Article DE RADIOACTIVITY, RESIDUAL; RADON DECAY PRODUCTS; EXPOSURE, RADIATION; EPIDEMIOLOGY AB CR-39 plastic was attached to household glass objects to learn whether residual radioactivity from radon decay products could be measured and correlated with cumulative radon exposures over defined time periods. Such an approach could be used to increase the completeness of exposure data collected in epidemiologic studies of residential radon. Inability to estimate radon concentrations for all residences adversely effects statistical power and thus the ability to detect an effect of radon exposure on lung cancer risk. A feasibility study was performed to determine if affixing CR-39 surface monitors to selected glass, ceramic, or enameled objects provided comparable estimates of past residential radon exposure to those obtained from year-long ambient alpha track-etch measurements. The CR-39 measurements of alpha activity in the surface of selected objects correlated with ambient radon measurements (R2 = 0.48) provided that reliable information was obtained on the history and age of the objects. This technique has now been incorporated into an epidemiologic study of radon and lung cancer to more fully estimate past exposure to indoor radon. C1 SURVEY RES ASSOCIATES, BALTIMORE, MD 21209 USA. MISSOURI DEPT HLTH, COLUMBIA, MO 65203 USA. NCI, BETHESDA, MD 20814 USA. SURVEY RES ASSOCIATES, ST LOUIS, MO 63124 USA. RP MAHAFFEY, JA (reprint author), PACIFIC NW LAB, BATTELLE BLVD,POB 999, RICHLAND, WA 99352 USA. FU NCI NIH HHS [Y01-CP0-0054] NR 13 TC 45 Z9 45 U1 0 U2 1 PU LIPPINCOTT WILLIAMS & WILKINS PI PHILADELPHIA PA TWO COMMERCE SQ, 2001 MARKET ST, PHILADELPHIA, PA 19103 USA SN 0017-9078 EI 1538-5159 J9 HEALTH PHYS JI Health Phys. PD APR PY 1993 VL 64 IS 4 BP 381 EP 391 DI 10.1097/00004032-199304000-00005 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 LN111 UT WOS:A1993LN11100005 PM 8449720 ER PT J AU KANG, C NEWTON, D WARNER, AJ ABSOLOM, TA KRUCHTEN, DA ANDERSON, AL PALMER, HE AF KANG, C NEWTON, D WARNER, AJ ABSOLOM, TA KRUCHTEN, DA ANDERSON, AL PALMER, HE TI A COMPARISON OF TECHNIQUES IN THE ASSESSMENT OF CHEST-WALL THICKNESS AND COMPOSITION SO HEALTH PHYSICS LA English DT Article DE PLUTONIUM; ULTRASOUND; MAGNETIC RESONANCE IMAGING; LUNGS, HUMAN ID LUNG AB The thickness and composition of defined regions of the anterior chest wall are important factors in the assessment of pulmonary plutonium by low-energy x ray counting. Estimates of these quantities are reported for seven male subjects investigated by three laboratories using ultrasonic methods and by a fourth laboratory using magnetic resonance imaging. No important bias was found in any one laboratory's estimates of chest wall thickness relative to those of the others, but differences of up to 6 mm were noted for individual subjects. The discrepancies are believed principally to reflect the different sampling regimes adopted to reach a representative mean chest wall thickness over the region of interest from measurements at selected points. The adipose-tissue component was consistently found to be lower when assessed by magnetic resonance imaging compared with estimates by ultrasound, but the differences were unimportant in the context of plutonium assessment. C1 ATOM WEAP ESTAB, READING RG7 4PR, BERKS, ENGLAND. LAWRENCE LIVERMORE NATL LAB, LIVERMORE, CA 94550 USA. PACIFIC NW LAB, RICHLAND, WA 99352 USA. RP KANG, C (reprint author), ATOM ENERGY AUTHOR ENVIRONM & ENERGY, HARWELL BIOMED RES, HARWELL LAB, B364, DIDCOT OX11 0RA, ENGLAND. NR 7 TC 8 Z9 8 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 APR PY 1993 VL 64 IS 4 BP 406 EP 411 DI 10.1097/00004032-199304000-00008 PG 6 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 LN111 UT WOS:A1993LN11100008 PM 8449723 ER PT J AU FISENNE, IM AF FISENNE, IM TI INITIAL STUDY OF PB-210 IN INDOOR AIR SO HEALTH PHYSICS LA English DT Note DE AIR SAMPLING; PB-210; PO-210; RADON PROGENY AB An exploratory program was undertaken to determine the feasibility of measuring the indoor air concentration of Pb-210. Low flow rate pumps and membrane filters were used to collect samples in an office. The air filter samples were stored for 1.6 y and Po-210 was chemically separated and measured by alpha spectrometry. Unsupported Po-210 was also determined in air samples collected at a later time. The average air concentrations were 150 muBq Pb-210 m-3 and 12 muBq Po-210 m-3. The average indoor to outdoor ratio of Pb-210 in air is estimated to be 0.25. RP FISENNE, IM (reprint author), US DOE, ENVIRONM MEASUREMENTS LAB, 376 HUDSON ST, NEW YORK, NY 10014 USA. NR 6 TC 4 Z9 4 U1 1 U2 2 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 APR PY 1993 VL 64 IS 4 BP 423 EP 425 DI 10.1097/00004032-199304000-00012 PG 3 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 LN111 UT WOS:A1993LN11100012 PM 8449727 ER PT J AU THOMAS, RG AF THOMAS, RG TI MISSTATEMENT ON RADIUM DIAL WORKERS SO HEALTH PHYSICS LA English DT Letter RP THOMAS, RG (reprint author), ARGONNE NATL LAB, DIV ENVIRONM RES, ARGONNE, IL 60439 USA. NR 1 TC 1 Z9 1 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 APR PY 1993 VL 64 IS 4 BP 433 EP 433 PG 1 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 LN111 UT WOS:A1993LN11100014 PM 8449729 ER PT J AU MEINHOLD, CB THOMAS, R AF MEINHOLD, CB THOMAS, R TI 1990 RECOMMENDATIONS OF THE ICRP SO HEALTH PHYSICS LA English DT Letter C1 LAWRENCE LIVERMORE NATL LAB, DEPT HAZARDS CONTROL, JOINT ICRP ICRU TASK GRP, LIVERMORE, CA 94550 USA. RP MEINHOLD, CB (reprint author), NATL COUNCIL RADIAT PROTECT & MEASUREMENTS, ICRP COMM 2, 7910 WOODMONT AVE, BETHESDA, MD 20814 USA. NR 1 TC 0 Z9 0 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 APR PY 1993 VL 64 IS 4 BP 437 EP 437 PG 1 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 LN111 UT WOS:A1993LN11100018 ER PT J AU SOHAL, MS AF SOHAL, MS TI FIELD TESTING OF A PROBE TO MEASURE FOULING IN AN INDUSTRIAL FLUE-GAS STREAM SO HEAT TRANSFER ENGINEERING LA English DT Article AB In order to design an efficient heat exchanger accurately, a better understanding is needed regarding the foulants that are deposited on the heat transfer surfaces of heat exchangers to recover energy from hot flue gases in industrial furnaces. This article briefly describes the design and fabrication of a gas-side fouling measuring device, and its testing in an industrial environment. It describes probe fabrication, instrumentation used for recording the data, field test location, tests performed, and data analysis. The conclusions of the tests performed are summarized. Although fouling deposits on the probe were minimal, the tests proved that the probe is capable of measuring fouling in a harsh industrial environment. RP SOHAL, MS (reprint author), EG&G IDAHO INC,IDAHO NATL ENGN LAB,IDAHO FALLS,ID 83415, USA. NR 9 TC 4 Z9 4 U1 0 U2 0 PU HEMISPHERE PUBL CORP PI BRISTOL PA 1900 FROST ROAD, SUITE 101, BRISTOL, PA 19007-1598 SN 0145-7632 J9 HEAT TRANSFER ENG JI Heat Transf. Eng. PD APR-JUN PY 1993 VL 14 IS 2 BP 51 EP 61 DI 10.1080/01457639308939800 PG 11 WC Thermodynamics; Engineering, Mechanical; Mechanics SC Thermodynamics; Engineering; Mechanics GA LC971 UT WOS:A1993LC97100007 ER PT J AU DELOACH, LD PAYNE, SA CHASE, LL SMITH, LK KWAY, WL KRUPKE, WF AF DELOACH, LD PAYNE, SA CHASE, LL SMITH, LK KWAY, WL KRUPKE, WF TI EVALUATION OF ABSORPTION AND EMISSION PROPERTIES OF YB-3+ DOPED CRYSTALS FOR LASER APPLICATIONS SO IEEE JOURNAL OF QUANTUM ELECTRONICS LA English DT Article ID SPECTRA; IONS AB The emission and absorption properties of numerous host crystals doped with Yb3+ ions have been studied. The hosts which have been selected present a variety of crystal field environments for the ytterbium ion, including fluoride and oxide crystals with six-, seven-, eight-, nine- and twelvefold coordinated substitutional sites. The crystal compounds include LiYF4, LaF3, SrF2, BaF2, KCaF3, KY3F10, Rb2NaYF6, BaY2F8, Y2SiO5, Y3Al5O12, YAlO3, LuPO4, Ca5(PO4)3F, LiYO2, and ScBO3. Spectral determinations have been made of the resonant absorption and emission cross sections between 850 and 1100 nm, and the emission decay times of the upper laser level have been measured. The emission cross sections have been evaluated using the absorption cross section and principle of reciprocity, and again using the Fuchtbauer-Ladenburg formula. Agreement between the two methods is within 20% for most materials. The results of this survey are discussed in the framework of requirements for an effective diode-pumped Yb3+ laser system. Ca5(PO4)3F:Yb is predicted to exhibit the most useful laser properties and is expected to be superior to Y3Al5O12:Yb in many key spectroscopic parameter values. RP DELOACH, LD (reprint author), LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550, USA. NR 33 TC 602 Z9 621 U1 30 U2 119 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9197 J9 IEEE J QUANTUM ELECT JI IEEE J. Quantum Electron. PD APR PY 1993 VL 29 IS 4 BP 1179 EP 1191 DI 10.1109/3.214504 PG 13 WC Engineering, Electrical & Electronic; Optics; Physics, Applied SC Engineering; Optics; Physics GA LD712 UT WOS:A1993LD71200022 ER PT J AU REDINBO, GR NAPOLITANO, LM ANDALEON, DD AF REDINBO, GR NAPOLITANO, LM ANDALEON, DD TI MULTIBIT CORRECTING DATA INTERFACE FOR FAULT-TOLERANT SYSTEMS SO IEEE TRANSACTIONS ON COMPUTERS LA English DT Article DE DUAL ORTHOGONAL BASIS; ERROR-CORRECTING CODING; FAULT-DETECTING DECODER; FIELD PROGRAMMABLE GATE ARRAYS; FINITE FIELD ARITHMETIC; MEMORY SYSTEM RELIABILITY; MULTIBIT CORRECTION; REED-SOLOMON CODES; SYSTEM FAULT TOLERANCE ID ERROR DETECTING CODES AB Failures of complex integrated circuits in modern computer systems can affect several bits simultaneously, easily overwhelming standard commercially available correction or detection subassemblies. A fault-detecting, bidirectional data interface between uncoded data from one part, such as a processor, and coded data in the rest of the system is described. This interface is capable of correcting a single multibit symbol error or detecting the occurrence of two such errors. The device uses a shortened Reed-Solomon code and two practical symbol sizes are considered; nibble (4-bit) errors are protected by a (40, 32) binary equivalent shortened code while byte errors are covered by a (80, 64) binary-sized code. The Reed-Solomon codes have maximum protection levels, even when shortened, and allow simplifying design options. A dual orthogonal basis used for the symbols' respresentations provides significant hardware savings. The interface unit achieves internal fault detection, sensing any single subassembly failure, by comparing regenerated parity values in a totally self-checking equality checker. The probability of undetected error and memory reliability values are easily calculated since the weight distributions for shortened Reed-Solomon codes are developed. A fault-tolerent ultra-reliable memory module is proposed and its reliabilities evaluated. An example design for a nibble-correcting interface is realized using a single desktop programmable gate array and requires a fault detection overhead in module count of about 15 %. C1 STANFORD UNIV,STANFORD,CA 94305. SANDIA NATL LABS,LIVERMORE,CA 94551. RP REDINBO, GR (reprint author), UNIV CALIF DAVIS,DEPT ELECT ENGN & COMP SCI,DAVIS,CA 95616, USA. NR 22 TC 6 Z9 6 U1 0 U2 0 PU IEEE COMPUTER SOC PI LOS ALAMITOS PA 10662 LOS VAQUEROS CIRCLE, PO BOX 3014, LOS ALAMITOS, CA 90720-1264 SN 0018-9340 J9 IEEE T COMPUT JI IEEE Trans. Comput. PD APR PY 1993 VL 42 IS 4 BP 433 EP 446 DI 10.1109/12.214690 PG 14 WC Computer Science, Hardware & Architecture; Engineering, Electrical & Electronic SC Computer Science; Engineering GA LD491 UT WOS:A1993LD49100005 ER PT J AU RAO, NSV AF RAO, NSV TI COMPUTATIONAL-COMPLEXITY ISSUES IN OPERATIVE DIAGNOSIS OF GRAPH-BASED SYSTEMS SO IEEE TRANSACTIONS ON COMPUTERS LA English DT Article DE ALARM PLACEMENT PROBLEMS; ALGORITHMS AND COMPLEXITY; FAULT DIAGNOSIS; NP-COMPLETE PROBLEMS; OPERATIVE DIAGNOSIS; SINGLE AND MULTIPLE FAULTS ID FAULT-DIAGNOSIS; MODEL; SEARCH AB Systems that can be modeled as graphs, such thal nodes represent the components and the edges represent the fault propagation between the components, are considered. Some components are equipped with alarms that ring in response to faulty conditions. In these systems, two types of problems are studied: a) fault diagnosis, and b) alarm placement. The fault diagnosis problems deal with computing the set of all potential failure sources that correspond to a set of ringing alarms A(R). First, the single faults, where exactly one component can become faulty at any time, are considered. Systems are classified into zero-time and nonzero-time systems based on fault propagation times, and the latter is further classified based on the knowledge of propagation times. For each of these classes algorithms are presented for single fault diagnosis. The problem of detecting multiple faults is shown to be NP-complete. An alarm placement problem, that requires a single fault to be uniquely diagnosed, is examined; various versions of this problem are shown to be NP-complete. The single fault diagnosis algorithms have been implemented and tested. RP RAO, NSV (reprint author), OAK RIDGE NATL LAB,INTELLIGENT SYST SECT,OAK RIDGE,TN 37831, USA. OI Rao, Nageswara/0000-0002-3408-5941 NR 36 TC 48 Z9 50 U1 0 U2 2 PU IEEE COMPUTER SOC PI LOS ALAMITOS PA 10662 LOS VAQUEROS CIRCLE, PO BOX 3014, LOS ALAMITOS, CA 90720-1264 SN 0018-9340 J9 IEEE T COMPUT JI IEEE Trans. Comput. PD APR PY 1993 VL 42 IS 4 BP 447 EP 457 DI 10.1109/12.214691 PG 11 WC Computer Science, Hardware & Architecture; Engineering, Electrical & Electronic SC Computer Science; Engineering GA LD491 UT WOS:A1993LD49100006 ER PT J AU UPADHYAYA, SJ PHAM, H AF UPADHYAYA, SJ PHAM, H TI ANALYSIS OF NONCOHERENT SYSTEMS AND AN ARCHITECTURE FOR THE COMPUTATION OF THE SYSTEM RELIABILITY SO IEEE TRANSACTIONS ON COMPUTERS LA English DT Article DE ALGORITHMS; CELLULAR ARCHITECTURE; NONCOHERENT SYSTEMS; OPTIMIZATION; RELIABILITY ANALYSIS ID OF-N SYSTEMS AB A k-to-l-out-of-n system is a noncoherent system in which no fewer than k and no more than l out of n units are to function for the successful operation of a system. Examples of noncoherent systems are found in multiprocessor, communication, and transportation applications. A noncoherent system is very general and includes the parallel, series, and N-modular redundancy systems as special cases. The reliability of noncoherent systems has been analyzed by several researchers but the number of computational steps for the evaluation has not reached the minimum. Earlier techniques based on the generalizations of the inclusion-exclusion principle and the event-space approach for computing reliability are inefficient. After briefly reviewing these and some of the recent and more efficient techniques, an alternative approach based on the elementary event method is presented for computing the reliability of noncoherent systems. A salient feature of this new technique is its adaptability to a simple cellular realization in hardware. This cellular implementation improves the computational complexity from quadratic to linear-order time. Theoretical results on the optimization issues of noncoherent systems are also presented. C1 BOEING CO, SEATTLE, WA 98124 USA. EG&G IDAHO INC, IDAHO NATL ENGN LAB, SYST SAFETY & RISK EVALUAT GRP, IDAHO FALLS, ID 83415 USA. RP UPADHYAYA, SJ (reprint author), SUNY Buffalo, DEPT ELECT & COMP ENGN, BUFFALO, NY 14260 USA. NR 7 TC 7 Z9 7 U1 0 U2 0 PU IEEE COMPUTER SOC PI LOS ALAMITOS PA 10662 LOS VAQUEROS CIRCLE, PO BOX 3014, LOS ALAMITOS, CA 90720-1314 USA SN 0018-9340 J9 IEEE T COMPUT JI IEEE Trans. Comput. PD APR PY 1993 VL 42 IS 4 BP 484 EP 493 DI 10.1109/12.214699 PG 10 WC Computer Science, Hardware & Architecture; Engineering, Electrical & Electronic SC Computer Science; Engineering GA LD491 UT WOS:A1993LD49100009 ER PT J AU MURPHY, MC ROTEM, D AF MURPHY, MC ROTEM, D TI MULTIPROCESSOR JOIN SCHEDULING SO IEEE TRANSACTIONS ON KNOWLEDGE AND DATA ENGINEERING LA English DT Article DE DATABASE SYSTEMS; JOIN SCHEDULING; MULTIPROCESSOR APPLICATIONS; PARALLEL COMPUTATION; RELATIONAL QUERY PROCESSING; SYSTEM PERFORMANCE EVALUATION AB Multiprocessors provide a cost effective high performance alternative for relational join execution. While traditional query processing algorithms can be effectively utilized to realize interquery parallelism, they are not well suited to exploiting intraquery parallelism. In this paper we present a practical join processing strategy which allows effective utilization of arbitrary degrees of parallelism in both the I/O subsystem and join processing (processor) subsystems. Analytic bounds on the minimum execution time, minimum number of processors, and processor utilization are presented along with bounds on the execution time given a fixed number of processors. These bounds assume sufficient buffers are available. We present an analytic lower bound on buffer requirements as well as a practical heuristic for use in limited buffer environments. The paper concludes with a sampling of corroborative simulation results. C1 SAN FRANCISCO STATE UNIV,DEPT COMP SCI,SAN FRANCISCO,CA 94132. SAN JOSE STATE UNIV,SCH BUSINESS,DEPT MKT & QUANT STUDIES,SAN JOSE,CA 95192. RP MURPHY, MC (reprint author), LAWRENCE BERKELEY LAB,COMP SCI RES DEPT,DIV INFORMAT & COMP SCI,BERKELEY,CA 94720, USA. NR 19 TC 4 Z9 4 U1 0 U2 0 PU IEEE COMPUTER SOC PI LOS ALAMITOS PA 10662 LOS VAQUEROS CIRCLE, PO BOX 3014, LOS ALAMITOS, CA 90720-1264 SN 1041-4347 J9 IEEE T KNOWL DATA EN JI IEEE Trans. Knowl. Data Eng. PD APR PY 1993 VL 5 IS 2 BP 322 EP 338 DI 10.1109/69.219739 PG 17 WC Computer Science, Artificial Intelligence; Computer Science, Information Systems; Engineering, Electrical & Electronic SC Computer Science; Engineering GA LH395 UT WOS:A1993LH39500011 ER PT J AU FEHLAU, PE AF FEHLAU, PE TI COMPARING A RECURSIVE DIGITAL-FILTER WITH THE MOVING-AVERAGE AND SEQUENTIAL PROBABILITY-RATIO DETECTION METHODS FOR SNM PORTAL MONITORS SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article AB We compared a recursive digital filter proposed as a detection method for French special nuclear material monitors with our detection methods, which employ a moving-average scaler or a sequential probability-ratio test. Each or our nine test subjects repeatedly carried a test source through a walk-through portal monitor that had the same nuisance-alarm rate with each method. We found that the average detection probability for the test source is also the same for each method. However, the recursive digital filter may have one drawback: its exponentially decreasing response to past radiation intensity prolongs the impact of any interference from radiation sources or radiation-producing machinery. We also examined the influence of each test subject on the monitor's operation by measuring individual attenuation factors for background and source radiation, then ranked the subjects' attenuation factors against their individual probabilities for detecting the test source. The one inconsistent ranking was probably caused by that subject's unusually long stride when passing through the portal. RP FEHLAU, PE (reprint author), LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545, USA. NR 4 TC 37 Z9 37 U1 1 U2 2 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD APR PY 1993 VL 40 IS 2 BP 143 EP 146 DI 10.1109/23.212330 PG 4 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA LA062 UT WOS:A1993LA06200012 ER PT J AU OBRIEN, E BENNETT, M CHERNIATIN, V CHI, CY CHIKANIAN, A DOLGOSHEIN, B KUMAR, S LISSAUER, D MCCORKLE, S MITCHELL, JT NAGAMIYA, S POLYCHRONAKOS, V POPE, K SIPPACH, W TAKAI, H TOY, M WANG, D WANG, YF WIGGINS, C WILLIS, W AF OBRIEN, E BENNETT, M CHERNIATIN, V CHI, CY CHIKANIAN, A DOLGOSHEIN, B KUMAR, S LISSAUER, D MCCORKLE, S MITCHELL, JT NAGAMIYA, S POLYCHRONAKOS, V POPE, K SIPPACH, W TAKAI, H TOY, M WANG, D WANG, YF WIGGINS, C WILLIS, W TI A TRANSITION RADIATION DETECTOR WHICH FEATURES ACCURATE TRACKING AND DE/DX PARTICLE IDENTIFICATION SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT NUCLEAR SCIENCE SYMP ( NSS 91 ) CY NOV 05-08, 1991 CL SANTA FE, NM SP IEEE AB We describe the results of a test run involving a Transition Radiation Detector that can both distinguish electrons from pions with momenta greater than 0.7 GeV/c and simultaneously track particles passing through the detector. The particle identification is accomplished through a combination of the detection of Transition Radiation from the electron and the differences in electron and pion energy loss (dE/dx) in the detector. The dE/dx particle separation is most efficient below 2 GeV/c while particle ID utilizing Transition Radiation is effective above 1.5 GeV/c. Combined, the electron-pion separation is better than 5 x 10(2). The single-wire, track-position resolution for the TRD is approximately 230 mum. C1 MOSCOW PHYS & ENGN INST,MOSCOW,RUSSIA. PN LEBEDEV PHYS INST,MOSCOW,RUSSIA. COLUMBIA UNIV,NEW YORK,NY 10027. YALE UNIV,NEW HAVEN,CT 06511. RP OBRIEN, E (reprint author), BROOKHAVEN NATL LAB,UPTON,NY 11973, USA. RI Takai, Helio/C-3301-2012 OI Takai, Helio/0000-0001-9253-8307 NR 4 TC 7 Z9 7 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 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD APR PY 1993 VL 40 IS 2 BP 153 EP 157 DI 10.1109/23.212332 PG 5 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA LA062 UT WOS:A1993LA06200014 ER PT J AU TODD, JH ROONEY, BD SPENCER, RH WESTON, LW AF TODD, JH ROONEY, BD SPENCER, RH WESTON, LW TI DATA ACQUISITION WORKSTATION FOR OAK-RIDGE ELECTRON LINEAR-ACCELERATOR SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT NUCLEAR SCIENCE SYMP ( NSS 91 ) CY NOV 05-08, 1991 CL SANTA FE, NM SP IEEE AB A new multiparameter data acquisition system for the Oak Ridge Electron Linear Accelerator (ORELA) [1] was developed, fabricated and tested. This system uses an IBM PS/2 Model 80-111 personal computer and a data handler with a 2048-word buffer. The buffer can accept data at a rate exceeding one million events per second in bursts of 512 words of 64-bits in length. The acquisition system, limited by software, can acquire data from 1, 2, or 3 digitizers; multiplex up to 4 detectors; read and control up to 16 scalers or registers; and output up to 32 dc logic lines that can be used to control external instrumentation. Software was developed for the OS/2 operating system, supporting multiparameter data storage for up to three million channels. Data can be collected in a background mode to make the computer available for other tasks while collecting data. The system also supports multiparameter biasing and can collect, crunch, and store data at rates of 30,000 events per second, each event containing up to 64-bits of information. A technical manual, ORNL/TM-11454, covering the use of the system has been published. RP TODD, JH (reprint author), OAK RIDGE NATL LAB,DIV INSTRUMENTAT & CONTROLS,POB 2008,OAK RIDGE,TN 37831, USA. NR 1 TC 0 Z9 0 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 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD APR PY 1993 VL 40 IS 2 BP 166 EP 169 DI 10.1109/23.212335 PG 4 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA LA062 UT WOS:A1993LA06200017 ER PT J AU DEVOL, TA MOSES, WW DERENZO, SE AF DEVOL, TA MOSES, WW DERENZO, SE TI MONTE-CARLO OPTIMIZATION OF DEPTH-OF-INTERACTION RESOLUTION IN PET CRYSTALS SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT NUCLEAR SCIENCE SYMP ( NSS 91 ) CY NOV 05-08, 1991 CL SANTA FE, NM SP IEEE ID LIGHT COLLECTION; DETECTOR AB The light distribution along one edge of a PET scintillation crystal was investigated with a Monte Carlo simulation. This position dependent light distribution can be used to measure the 511 keV photon interaction position in the crystal on an event by event basis, thus reducing radial elongation. The predicted full width at half maximum (FWHM) of the light distribution on the 3 x 30 mm surface of a 3 x 10 x 30 mm BGO crystal surrounded by diffuse reflector is 3.0 mm. This light distribution is constant for widths (originally 3 mm) between 1 and 6 mm, but decreases from 3.0 to 1.8 mm FWHM as the height is reduced from 10 to 3 mm. Other geometrical modifications were simulated, including corner reflectors on the opposing 3 x 30 mm surface. A promising geometry is a 2.2 x 5 x 30 mm BGO crystal, for which a 2.2 mm FWHM light distribution is predicted, which should yield a PET detector module with depth of interaction measurement resolution of 3.6 mm FWHM. C1 LAWRENCE BERKELEY LAB,BERKELEY,CA 94720. RP DEVOL, TA (reprint author), UNIV MICHIGAN,DEPT NUCL ENGN,ANN ARBOR,MI 48109, USA. NR 12 TC 8 Z9 8 U1 0 U2 2 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD APR PY 1993 VL 40 IS 2 BP 170 EP 174 DI 10.1109/23.212336 PG 5 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA LA062 UT WOS:A1993LA06200018 ER PT J AU MENG, JD KATZ, JE AF MENG, JD KATZ, JE TI USING A DIGITAL SIGNAL PROCESSOR AS A DATA STREAM CONTROLLER IN DIGITAL SUBTRACTION ANGIOGRAPHY SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT NUCLEAR SCIENCE SYMP ( NSS 91 ) CY NOV 05-08, 1991 CL SANTA FE, NM SP IEEE AB High speed, flexibility, and good arithmetic abilities make digital signal processors (DSP) a good choice as input/output controllers for real time applications. The DSP can be made to pre-process data in real time to reduce data volume, to open early windows on what is being acquired and to implement local servo loops. We present an example of a DSP as an input/output controller for a digital subtraction angiographic imaging system. The DSP pre-processes the raw data, reducing data volume by a factor of two, and is potentially capable of producing real-time subtracted images for immediate display. RP MENG, JD (reprint author), LAWRENCE BERKELEY LAB,DEPT ELECTR INSTRUMENTAT,DIV ENGN,BERKELEY,CA 94720, USA. NR 6 TC 0 Z9 0 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 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD APR PY 1993 VL 40 IS 2 BP 175 EP 178 DI 10.1109/23.212337 PG 4 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA LA062 UT WOS:A1993LA06200019 ER PT J AU HALBIG, JK KLOSTERBUER, SF AUGUSTSON, RH BOSLER, GE MENLOVE, HO MILLER, MC AF HALBIG, JK KLOSTERBUER, SF AUGUSTSON, RH BOSLER, GE MENLOVE, HO MILLER, MC TI APPLICATIONS FOR UNATTENDED, REMOTE NDA INSTRUMENTATION SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT NUCLEAR SCIENCE SYMP ( NSS 91 ) CY NOV 05-08, 1991 CL SANTA FE, NM SP IEEE AB Instruments developed for safeguards and the domestic nuclear industry to nondestructively assay nuclear materials are being used in unattended and remote monitoring applications. In large facilities, such instruments can be combined with more classical surveillance methods. The effective implementation of such systems involves the integration of physics knowledge and measurement experience, detectors and their supporting electronics, and computers and their software. Los Alamos has been involved in three types of applications: (a) radiation triggers for video surveillance, (b) unattended assay of materials moving in automated fabrication and process plants, and (c) monitoring radiation signatures to verify the movement of irradiated and unirradiated nuclear material. RP HALBIG, JK (reprint author), LOS ALAMOS NATL LAB,GRP N-1,MS E540,LOS ALAMOS,NM 87545, USA. NR 5 TC 1 Z9 1 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 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD APR PY 1993 VL 40 IS 2 BP 186 EP 193 DI 10.1109/23.212339 PG 8 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA LA062 UT WOS:A1993LA06200021 ER PT J AU STEWART, JR DALE, SJ KLEIN, KW AF STEWART, JR DALE, SJ KLEIN, KW TI MAGNETIC-FIELD REDUCTION USING HIGH PHASE ORDER LINES SO IEEE TRANSACTIONS ON POWER DELIVERY LA English DT Article; Proceedings Paper CT 1992 WINTER MEETING OF THE POWER ENGINEERING SOC OF THE IEEE CY JAN 26-30, 1992 CL NEW YORK, NY SP IEEE, POWER ENGN SOC AB Ground level electric, and more recently magnetic, fields from overhead power transmission lines are increasingly important considerations in right of way specification, with states setting or planning to set edge of right of way limits. Research has been conducted in high phase order power transmission wherein six or twelve phases are used to transmit power in less physical space and with reduced electrical environmental effects than conventional designs. The first magnetic field testing, as reported in this paper, has verified predictive methods for determination of magnetic fields from high phase order lines. Based on these analytical methods, field profiles have been determined for lines of different phase order of comparable power capacity. Potential advantages of high phase order as a means of field mitigation are discussed. C1 OAK RIDGE NATL LAB,OAK RIDGE,TN 37830. ENERGETICS INC,COLUMBIA,MD. RP STEWART, JR (reprint author), POWER TECHNOL INC,SCHENECTADY,NY 12301, USA. NR 11 TC 20 Z9 20 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 0885-8977 J9 IEEE T POWER DELIVER JI IEEE Trans. Power Deliv. PD APR PY 1993 VL 8 IS 2 BP 628 EP 636 DI 10.1109/61.216869 PG 9 WC Engineering, Electrical & Electronic SC Engineering GA LF421 UT WOS:A1993LF42100022 ER PT J AU STOUGHTON, RS ARAI, T AF STOUGHTON, RS ARAI, T TI A MODIFIED STEWART PLATFORM MANIPULATOR WITH IMPROVED DEXTERITY SO IEEE TRANSACTIONS ON ROBOTICS AND AUTOMATION LA English DT Article AB A novel design for a 6-DOF parallel manipulator is presented. The design is a modification of the Stewart Platform that places the legs of the manipulator on two concentric circles both at the base and at the end effector. The legs can therefore cross over one another in space without interference, which allows them to move closer to the horizontal. This brings the force/torque and velocity capacities in different directions more into balance. The degree of improvement attainable is quantified by defining a measure of dexterity as the average condition number of the Jacobian matrix over a centralized subregion of the workspace, and optimizing the manipulator design with respect to a weighted sum of dexterity and workspace volume. This measure of dexterity is compared with other measures on the basis of the singular values of the Jacobian. It is shown that the new design offers significantly improved dexterity over the traditional Stewart Platform design. C1 MECH ENGN LAB, TSUKUBA, IBARAKI 305, JAPAN. RP STOUGHTON, RS (reprint author), PACIFIC NW LAB, RICHLAND, WA 99352 USA. NR 16 TC 110 Z9 122 U1 5 U2 8 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 1042-296X J9 IEEE T ROBOTIC AUTOM JI IEEE Trans. Robot. Autom. PD APR PY 1993 VL 9 IS 2 BP 166 EP 173 DI 10.1109/70.238280 PG 8 WC Automation & Control Systems; Engineering, Electrical & Electronic; Robotics SC Automation & Control Systems; Engineering; Robotics GA LZ622 UT WOS:A1993LZ62200004 ER PT J AU EDELMAN, A STEWART, GW AF EDELMAN, A STEWART, GW TI SCALING FOR ORTHOGONALITY SO IEEE TRANSACTIONS ON SIGNAL PROCESSING LA English DT Letter ID EFFICIENT AB In updating algorthms where orthogonal transformations are accumulated, it is important to preserve the orthogonality of the product in the presence of rounding error. Moonen, Van Dooren, and Vandewalle have pointed out that simply normalizing the columns of the product tends to preserve orthogonality-though not, as DeGroat points out, to working precision. In this correspondence we give an analysis of the phenomenon. C1 LAWRENCE BERKELEY LAB,BERKELEY,CA 94720. UNIV MARYLAND,DEPT COMP SCI,COLL PK,MD 20742. UNIV MARYLAND,INST ADV COMP STUDIES,COLL PK,MD 20742. RP EDELMAN, A (reprint author), UNIV CALIF BERKELEY,DEPT MATH,BERKELEY,CA 94720, USA. NR 3 TC 6 Z9 6 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 1053-587X J9 IEEE T SIGNAL PROCES JI IEEE Trans. Signal Process. PD APR PY 1993 VL 41 IS 4 BP 1676 EP 1677 DI 10.1109/78.212741 PG 2 WC Engineering, Electrical & Electronic SC Engineering GA LA336 UT WOS:A1993LA33600015 ER PT J AU Malone, KT Fischer, TR AF Malone, Kevin T. Fischer, Thomas R. TI Trellis-Searched Adaptive Predictive Coding of Speech SO IEEE TRANSACTIONS ON SPEECH AND AUDIO PROCESSING LA English DT Article AB This paper incorporates trellis coded vector quantization (TCVQ) and forward adaptive predictive coding (APC) to form an efficient speech coding system operating at bit rates of 16 and 9.6 kb/s. The effectiveness of the system is studied for a variety of system parameters and utterances. Simulation results indicate that segmental signal-to-noise ratios as high as 23.8 and 15.4 dB are obtainable at 16 and 9.6 kb/s, respectively. The quality of the reconstructed speech is deemed to be excellent at 16 kb/s and very good at 9.6 kb/s. An algorithm for "optimizing" the residual codebooks is also presented. C1 [Malone, Kevin T.] Sandia Natl Labs, Commun Syst Div, Albuquerque, NM 87185 USA. [Fischer, Thomas R.] Washington State Univ, ECE Dept, Pullman, WA 99164 USA. RP Malone, KT (reprint author), Sandia Natl Labs, Commun Syst Div, POB 5800, Albuquerque, NM 87185 USA. FU National Science Foundation [NCR-8821764] FX Manuscript received June 26, 1990; revised March 5, 1992. This work was supported in part by the National Science Foundation under Grant NCR-8821764. Portions of this work were presented at the 1990 International Symposium on Information Theory and Its Applications, Waikiki, HI, November 27-30, 1990, and at the IEEE Global Telecommunications Conference, San Diego, CA, December 2-5, 1990. The associate editor coordinating the review for this paper and approving it for publication was Prof. Mark A. Clements. NR 28 TC 3 Z9 3 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855-4141 USA SN 1063-6676 J9 IEEE T SPEECH AUDI P JI IEEE Trans. Speech Audio Process. PD APR PY 1993 VL 1 IS 2 BP 196 EP 206 DI 10.1109/89.222878 PG 11 WC Acoustics; Engineering, Electrical & Electronic SC Acoustics; Engineering GA V04SQ UT WOS:000207078500007 ER PT J AU HAVSTAD, MA BROWN, DL MALTBY, JD EBERT, JL SELF, SA AF HAVSTAD, MA BROWN, DL MALTBY, JD EBERT, JL SELF, SA TI A RADIATION SOURCE FOR BOTH THE VISIBLE AND THE INFRARED SO INFRARED PHYSICS LA English DT Article AB A radiation source with high output in both the visible and infrared spectral ranges has been developed, and its operating parameters are described. The hot element, a carbon composite board, is simple to fabricate as well as to operate. The source has been compared to both a tungsten strip lamp and a Nernst glower. For applications where both the visible and infrared ranges are of interest, this source allows for simplified experimental design. C1 STANFORD UNIV,DEPT CHEM ENGN,STANFORD,CA 94305. RP HAVSTAD, MA (reprint author), LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550, USA. NR 5 TC 1 Z9 1 U1 1 U2 3 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0020-0891 J9 INFRARED PHYS PD APR PY 1993 VL 34 IS 2 BP 169 EP 174 DI 10.1016/0020-0891(93)90006-S PG 6 WC Optics; Physics, Applied SC Optics; Physics GA KZ374 UT WOS:A1993KZ37400006 ER PT J AU Thompson, JMT Stewart, HB AF Thompson, J. M. T. Stewart, H. B. TI A TUTORIAL GLOSSARY OF GEOMETRICAL DYNAMICS SO INTERNATIONAL JOURNAL OF BIFURCATION AND CHAOS LA English DT Review AB We present here an informal, encyclopedic glossary of terms and formulae covering the new geometrical concepts of nonlinear dynamics and chaos. It is arranged as an alphabetical dictionary, which can also be read as a connected introduction to the subject by following the go to instructions starting with the entry dynamical system and ending with archetypal equations. C1 [Thompson, J. M. T.] Univ Coll London, Ctr Nonlinear Dynam & Its Applicat, Civil Engn Bldg,Gower St, London WC1E 6BT, England. [Stewart, H. B.] Brookhaven Natl Lab, Math Sci Grp, Upton, NY 11973 USA. RP Thompson, JMT (reprint author), Univ Coll London, Ctr Nonlinear Dynam & Its Applicat, Civil Engn Bldg,Gower St, London WC1E 6BT, England. FU Science and Engineering Research Council of the UK FX J. M. T. Thompson acknowledges the award of a senior fellowship by the Science and Engineering Research Council of the UK. The glossary has been prepared for the second edition of Thompson & Stewart [1986], and is reproduced by courtesy of John Wiley and Sons. NR 10 TC 13 Z9 13 U1 0 U2 0 PU WORLD SCIENTIFIC PUBL CO PTE LTD PI SINGAPORE PA 5 TOH TUCK LINK, SINGAPORE 596224, SINGAPORE SN 0218-1274 EI 1793-6551 J9 INT J BIFURCAT CHAOS JI Int. J. Bifurcation Chaos PD APR PY 1993 VL 3 IS 2 BP 223 EP 239 DI 10.1142/S0218127493000180 PG 17 WC Mathematics, Interdisciplinary Applications; Multidisciplinary Sciences SC Mathematics; Science & Technology - Other Topics GA V44LQ UT WOS:000209750900001 ER PT J AU IRDAM, EA KIEFER, JH HARDING, LB WAGNER, AF AF IRDAM, EA KIEFER, JH HARDING, LB WAGNER, AF TI THE FORMALDEHYDE DECOMPOSITION CHAIN MECHANISM SO INTERNATIONAL JOURNAL OF CHEMICAL KINETICS LA English DT Article ID THERMAL UNIMOLECULAR REACTIONS; TRANSITION-STATE; RATE CONSTANTS; 1,3,5-TRIOXANE; H2CO->H2+CO; SURFACE; RANGE AB A kinetic mechanism for the chain decomposition of formaldehyde consistent with recent theoretical and experimental results is presented. This includes new calculations and measurements of the rate constant for the abstraction reaction CH2O + H --> HCO + H-2 The calculation uses a multi-reference configuration interaction wavefunction to construct the potential energy surface which is used in a tunneling-corrected TST calculation of the rate constant. The rate constant for the bond fission CH2O + M --> HCO + H + M at high temperatures was determined by an RRKM extrapolation of direct low temperature measurements. This mechanism has been successfully tested against laser-schlieren measurements covering the temperature range 2200-3200 K. These measurements are insensitive to all but the above two reactions and they confirm the large, non-Arrhenius rate for the abstraction reaction derived here from theory. Modeling of previous experiments using IR emission, ARAS, and CO laser absorption with this mechanism is quite satisfactory. The branching ratio of the rate of the faster molecular dissociation (CH2O + (M) --> CO + H-2 + (M)), to that of the bond fission reaction, was estimated to be no more than 2 or 3 over 2000 to 3000 K. Such a ratio is consistent with one recent theoretical estimate and most of the experimental observations. C1 ARGONNE NATL LAB,DIV CHEM,ARGONNE,IL 60439. RP IRDAM, EA (reprint author), UNIV ILLINOIS,DEPT CHEM ENGN,CHICAGO,IL 60680, USA. NR 39 TC 36 Z9 36 U1 1 U2 19 PU JOHN WILEY & SONS INC PI NEW YORK PA 605 THIRD AVE, NEW YORK, NY 10158-0012 SN 0538-8066 J9 INT J CHEM KINET JI Int. J. Chem. Kinet. PD APR PY 1993 VL 25 IS 4 BP 285 EP 303 DI 10.1002/kin.550250408 PG 19 WC Chemistry, Physical SC Chemistry GA KU422 UT WOS:A1993KU42200007 ER PT J AU KUNO, N MATSUO, H MIZUMOTO, Y LANGE, AE BEEMAN, JW HALLER, EE AF KUNO, N MATSUO, H MIZUMOTO, Y LANGE, AE BEEMAN, JW HALLER, EE TI 7 MATCHED BOLOMETERS FOR MILLIMETER-WAVE OBSERVATIONS SO INTERNATIONAL JOURNAL OF INFRARED AND MILLIMETER WAVES LA English DT Article ID DETECTORS AB We have fabricated a millimeter wave observation system using an array of bolometric detectors. The performance of the system depends largely on obtaining identical performance from each bolometer. We achieved a variance in the responsivity of less than 4% except for one of the seven elements. The bolometers had an electrical NEP of 1.3 x 10(-16) W/square-root Hz under radiation background loading of 30pW. We used an AC bridge readout circuit to significantly improve the stability of the array and showed that observations can be done without a mechanical beam switch. The bolometer array is now in use on the Nobeyama 45-m telescope for 150GHz observations. C1 TOHOKU UNIV,FAC SCI,INST ASTRON,AOBA KU,SENDAI,MIYAGI 980,JAPAN. COMMUN RES LABS,KOGANEI,TOKYO 184,JAPAN. KOBE UNIV,FAC SCI,DEPT PHYS,NADA KU,KOBE 657,JAPAN. UNIV CALIF BERKELEY,DEPT PHYS,BERKELEY,CA 94720. LAWRENCE BERKELEY LAB,BERKELEY,CA 94720. UNIV CALIF BERKELEY,DEPT MAT SCI & MINERAL ENGN,BERKELEY,CA 94720. RP KUNO, N (reprint author), NOBEYAMA RADIO OBSERV,MINAMIMAKI,MINAMISA KU,NAGANO 38413,JAPAN. NR 8 TC 20 Z9 20 U1 0 U2 0 PU PLENUM PUBL CORP PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 SN 0195-9271 J9 INT J INFRARED MILLI JI Int. J. Infrared Millimeter Waves PD APR PY 1993 VL 14 IS 4 BP 749 EP 762 DI 10.1007/BF02084285 PG 14 WC Engineering, Electrical & Electronic; Optics; Physics, Applied SC Engineering; Optics; Physics GA KX639 UT WOS:A1993KX63900002 ER PT J AU MACKLIS, RM BERESFORD, BA LIN, JY ATCHER, RW HUMM, JL AF MACKLIS, RM BERESFORD, BA LIN, JY ATCHER, RW HUMM, JL TI MURINE HEMATOPOIETIC ABLATION BY ALPHA-PARTICLE-EMITTING RADIOPHARMACEUTICALS - A POTENTIAL PREPARATIVE REGIMEN FOR BONE-MARROW TRANSPLANTATION SO INTERNATIONAL JOURNAL OF ONCOLOGY LA English DT Article DE ALPHA-PARTICLES; RADIOBIOLOGY; BONE MARROW; HORMESIS AB Although short-lived alpha-particle-emitting radiopharmaceuticals are currently under evaluation for biologically targeted radiotherapy, very little is known about the dose-response kinetics of the hematosuppression produced by low level or transient exposure to these compounds while in the circulation. We have used hematopoietic progenitor cell colony-forming-unit assays to establish the dose-response curve for Bi-212 alpha particle radiation delivered in vitro, and have compared it to the dose-response curves for equivalent doses of Y-90 beta and Cs-137 gamma radiation. We then evaluated the dose-response effects for these radiopharmaceuticals after in vivo injection in mice. Both in vitro and in vivo, the Bi-212 was extremely hematosuppressive (50% inhibitory dose 20-30 cGy in culture) but this myelosuppression was transient at low or intermediate doses. Serum froin mice recovering from Bi-212-induced hematosuppression produced significant stimulation of naive syngeneic marrow progenitor cells, supporting the existence of a physiologic feedback mechanism that involves a poorly defined humoral factor released after radiation injury. Short-lived alpha emitters may be well suited to the development of tumor-seeking radiopharmaceuticals that can be used in the preparation of patients for autologous and allogeneic marrow transplantation. C1 ARGONNE NATL LAB,DIV BIOL,ARGONNE,IL 60439. ARGONNE NATL LAB,DIV CHEM,ARGONNE,IL 60439. RP MACKLIS, RM (reprint author), HARVARD UNIV,SCH MED,DANA FARBER CANC INST,HARVARD JOINT CTR RADIAT THERAPY,50 BINNEY ST,BOSTON,MA 02115, USA. OI Atcher, Robert/0000-0003-4656-2247 NR 16 TC 8 Z9 8 U1 0 U2 0 PU INT JOURNAL ONCOLOGY PI ATHENS PA C/O PROFESSOR D A SPANDIDOS, EDITORIAL OFFICE, 1, S MERKOURI ST, ATHENS 116 35, GREECE SN 1019-6439 J9 INT J ONCOL JI Int. J. Oncol. PD APR PY 1993 VL 2 IS 4 BP 711 EP 715 PG 5 WC Oncology SC Oncology GA KU308 UT WOS:A1993KU30800035 PM 21573615 ER PT J AU ANDERSON, IE AF ANDERSON, IE TI POWDER-METALLURGY AND PARTICULATE MATERIALS RESEARCH AT AMES-LABORATORY AND IOWA-STATE-UNIVERSITY SO INTERNATIONAL JOURNAL OF POWDER METALLURGY LA English DT Article AB The programs in powder metallurgy (P/M) and particulate materials processing at Ames Laboratory and Iowa State University span the range of powder synthesis, processing, consolidation, and mechanical working and include studies on metal and ceramic particulate materials. Ames Laboratory's activities in powder-based research are conducted under the umbrella of Iowa State University's Institute for Physical Research and Technology (IPRT). This consortium of 12 research and technology development centers draws together the strengths of the federal Ames Laboratory and several targeted research centers at Iowa State. RP ANDERSON, IE (reprint author), IOWA STATE UNIV SCI & TECHNOL,INST PHYS RES & TECHNOL,AMES LAB,122 MET DEV,AMES,IA 50011, USA. NR 0 TC 2 Z9 2 U1 0 U2 0 PU AMER POWDER METALLURGY INST PI PRINCETON PA 105 COLLEGE ROAD EAST, PRINCETON, NJ 08540 SN 0888-7462 J9 INT J POWDER METALL JI Int. J. Powder Metall. PD APR PY 1993 VL 29 IS 2 BP 177 EP 187 PG 11 WC Metallurgy & Metallurgical Engineering SC Metallurgy & Metallurgical Engineering GA LA882 UT WOS:A1993LA88200009 ER PT J AU HANSEN, JS TRESS, JE NAFZIGER, RH AF HANSEN, JS TRESS, JE NAFZIGER, RH TI CARBOTHERMIC REDUCTION OF UNITED-STATES FERRUGINOUS MANGANESE RESOURCES SO JOM-JOURNAL OF THE MINERALS METALS & MATERIALS SOCIETY LA English DT Article RP HANSEN, JS (reprint author), US BUR MINES,ALBANY RES CTR,DIV PROC MET,PYROMETALLURGY GRP,ALBANY,OR, USA. NR 23 TC 0 Z9 0 U1 0 U2 1 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 APR PY 1993 VL 45 IS 4 BP 59 EP 63 PG 5 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering; Mineralogy; Mining & Mineral Processing SC Materials Science; Metallurgy & Metallurgical Engineering; Mineralogy; Mining & Mineral Processing GA KV785 UT WOS:A1993KV78500013 ER PT J AU CONRY, MJ DUNNE, B AF CONRY, MJ DUNNE, B TI EFFECTS OF NITROGEN TIMING AND FREQUENCY OF FUNGICIDE APPLICATIONS ON GRAIN YIELDS OF WINTER BARLEY IN IRELAND SO JOURNAL OF AGRICULTURAL SCIENCE LA English DT Article ID GROWTH; DISEASE; DATE AB The effects of varying the timing of nitrogen application and the frequency of fungicide sprays on the incidence of foliar disease and on the grain yield of winter barley (cv. Panda) were investigated at two sites in Ireland over three years, 1986-88. Nitrogen application timing had little effect on the amount of foliar necrosis due to disease but delaying application of all the nitrogen until April significantly reduced grain yields in two of the three years when compared with standard split dressings in March and April. The reductions in yield reflected small differences in 1000-grain weight. The number of fungicide sprays applied had significant effects on the amount of foliar necrosis and on grain yields. One-spray and two-spray programmes increased average yield by 16 and 32%, respectively. The yield increases were attributable to more ears/m2 and larger grains (greater 1000-grain weight). Fungicides also delayed the onset and significantly reduced the amount of brackling. Delaying nitrogen application in the spring did not decrease the number of fungicide sprays required to achieve maximum yield. RP CONRY, MJ (reprint author), OAK PK RES CTR,CARLOW,IRELAND. NR 16 TC 4 Z9 5 U1 0 U2 3 PU CAMBRIDGE UNIV PRESS PI NEW YORK PA 40 WEST 20TH STREET, NEW YORK, NY 10011-4211 SN 0021-8596 J9 J AGR SCI JI J. Agric. Sci. PD APR PY 1993 VL 120 BP 181 EP 186 PN 2 PG 6 WC Agriculture, Multidisciplinary SC Agriculture GA KY481 UT WOS:A1993KY48100005 ER PT J AU SPECHT, ED WALKER, FJ AF SPECHT, ED WALKER, FJ TI A METHOD FOR THE ACCURATE DETERMINATION OF CRYSTAL TRUNCATION ROD INTENSITIES BY X-RAY-DIFFRACTION SO JOURNAL OF APPLIED CRYSTALLOGRAPHY LA English DT Article ID 001 TWIST BOUNDARIES; GOLD AB A method is described for determining the structure factor F(Q) at a scattering vector Q along a crystal truncation rod (CTR) by measuring the total power diffracted with die crystal fixed. When a detector collects the entire diffracted beam, P(CTR)/P0 = psigma(T)[lambda\F(Q)\/a0 sin theta sin chi]2, where P0 and P(CTR) are the powers of the incident and diffracted beams, p is a polarization factor, sigma(T) is the Thompson cross section, lambda is the X-ray wavelength, a0 is the area of a two-dimensional unit cell and theta and chi are diffractometer angles. No terms due to instrumental resolution are required for measurement of the structure factor. Simple expressions are derived relating structure factors to the integrated intensity of rocking curves employing a receiving slit wide enough to accept the diffracted beam in one direction only. Measurements employing a narrow slit are useful in measuring CTR intensity at grazing incidence (i.e. small perpendicular momentum transfer) or for specular reflection (i.e. small parallel momentum transfer). For the more general case (large perpendicular and parallel momentum transfer), accurate measurements are more easily made when the detector collects the entire diffracted beam. RP SPECHT, ED (reprint author), OAK RIDGE NATL LAB,DIV MET & CERAM,OAK RIDGE,TN 37831, USA. RI Specht, Eliot/A-5654-2009 OI Specht, Eliot/0000-0002-3191-2163 NR 9 TC 26 Z9 26 U1 0 U2 5 PU MUNKSGAARD INT PUBL LTD PI COPENHAGEN PA 35 NORRE SOGADE, PO BOX 2148, DK-1016 COPENHAGEN, DENMARK SN 0021-8898 J9 J APPL CRYSTALLOGR JI J. Appl. Crystallogr. PD APR 1 PY 1993 VL 26 BP 166 EP 171 DI 10.1107/S0021889892011592 PN 2 PG 6 WC Chemistry, Multidisciplinary; Crystallography SC Chemistry; Crystallography GA KY851 UT WOS:A1993KY85100003 ER PT J AU ALLEN, PG CONRADSON, SD PENNERHAHN, JE AF ALLEN, PG CONRADSON, SD PENNERHAHN, JE TI A 4-POINT CRYSTAL BENDER FOR DISPERSIVE-X-RAY ABSORPTION-SPECTROSCOPY SO JOURNAL OF APPLIED CRYSTALLOGRAPHY LA English DT Article ID SYNCHROTRON RADIATION; SPECTROMETER; OPTICS; SYSTEM; MODE AB A new crystal bender for dispersive X-ray absorption fine-structure spectroscopy (XAFS) has been built and its performance characterized. The bender employs an adjustable four-point bending mechanism and a contoured crystal, which makes it possible to produce an excellent approximation of the ideal elliptical bend from 8000 to 20 000 eV with a single such Si (220) crystal. With the near-elliptical optics, it is possible to achieve a focus size of 175 mum with a 5 mm source and simultaneously to achieve a useful bandpass of 700 at 9000, 1200 at 11 500 and 2000 eV at 18 000 eV. The upper limit on the resolution, which is dictated by the finite source size in this configuration, is 2-5 eV for all of the energy ranges studied. C1 UNIV MICHIGAN,DEPT CHEM,ANN ARBOR,MI 48109. RP ALLEN, PG (reprint author), LOS ALAMOS NATL LAB,ELECTR RES GRP,LOS ALAMOS,NM 87545, USA. NR 18 TC 19 Z9 19 U1 0 U2 4 PU MUNKSGAARD INT PUBL LTD PI COPENHAGEN PA 35 NORRE SOGADE, PO BOX 2148, DK-1016 COPENHAGEN, DENMARK SN 0021-8898 J9 J APPL CRYSTALLOGR JI J. Appl. Crystallogr. PD APR 1 PY 1993 VL 26 BP 172 EP 179 DI 10.1107/S0021889892009038 PN 2 PG 8 WC Chemistry, Multidisciplinary; Crystallography SC Chemistry; Crystallography GA KY851 UT WOS:A1993KY85100004 ER PT J AU MEEKS, E CAPPELLI, MA AF MEEKS, E CAPPELLI, MA TI 2-TEMPERATURE FLUID MODEL FOR HIGH-PRESSURE PLASMAS IN CONTACT WITH COOLED ELECTRODES SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID RF GLOW-DISCHARGES; BOUNDARY-LAYER; TIME AB A detailed continuum model of a weakly ionized plasma in stagnation flow against an electrically biased surface is presented. The model includes bulk fluid motion as well as electron and ion momentum and continuity equations in both general and quasineutral formulations. The inclusion of both electron and bulk energy equations allows for the determination of electron temperature and deviations from local thermodynamic equilibrium. Results for the quasineutral model demonstrate the importance of considering thermal nonequilibrium in the evaluation of plasma properties in the presheath region. The evaluation of transport properties is self-consistent with properties for the charged species depending on the calculated electric field and neutral number density. In addition to investigating thermal boundary layer and fluid flow effects, a finite electron-ion recombination rate at the electrode surface is employed and the consequences of varying this boundary condition are explored. C1 STANFORD UNIV,DEPT MECH ENGN,STANFORD,CA 94305. RP MEEKS, E (reprint author), SANDIA NATL LABS,LIVERMORE,CA 94555, USA. NR 41 TC 11 Z9 11 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 APR 1 PY 1993 VL 73 IS 7 BP 3172 EP 3182 DI 10.1063/1.352961 PG 11 WC Physics, Applied SC Physics GA KV031 UT WOS:A1993KV03100009 ER PT J AU ZHU, YM SABATINI, RL WANG, YL SUENAGA, M AF ZHU, YM SABATINI, RL WANG, YL SUENAGA, M TI EFFECTS OF OZONE OXYGENATION OF YBA2CU3O7-DELTA THIN-CRYSTALS SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID TWIN AB We report the effects of ozone oxygenation of YBa2Cu3O7-delta thin crystals for eliminating local fluctuation in oxygen content, which is known to exist even in normal delta almost-equal-to 0 samples. An optimum ozone annealing condition was determined based on the microstructure and the uniformity of oxygen content of the samples. We observed the formation of fine-spacing twins running perpendicular to the original twins at thin areas and attributed this to accommodating the local strain due to oxygen uptake during ozone annealing. RP ZHU, YM (reprint author), BROOKHAVEN NATL LAB,DIV MAT SCI,UPTON,NY 11973, USA. NR 11 TC 11 Z9 11 U1 0 U2 0 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 APR 1 PY 1993 VL 73 IS 7 BP 3407 EP 3410 DI 10.1063/1.352941 PG 4 WC Physics, Applied SC Physics GA KV031 UT WOS:A1993KV03100041 ER PT J AU RUSSELL, NM BREILAND, WG AF RUSSELL, NM BREILAND, WG TI A SURFACE KINETICS MODEL FOR THE GROWTH OF SI1-XGEX FILMS FROM SIH4/GEH4 MIXTURES SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID CHEMICAL VAPOR-DEPOSITION; TEMPERATURE-DEPENDENCE; SILICON; DECOMPOSITION; SI(100)-(2X1); HYDROGEN; EPITAXY; SILANE; PHASE AB A model has been developed that semiquantitatively describes the kinetics of Si1-xGex alloy deposition over a wide range of temperatures in the absence of gas-phase chemistry. The salient feature of the model is that the kinetics of germane and silane deposition are treated as parallel processes, each with an adsorption step in series with a hydrogen desorption step. The two processes are coupled by competition for sites in the adsorption process, and fast equilibration between silicon and germanium hydride on the surface. The model is fit to, and compared with, data available in the recent literature. C1 SANDIA NATL LABS 1126,ALBUQUERQUE,NM 87185. RP RUSSELL, NM (reprint author), UNIV TEXAS,DEPT CHEM ENGN,AUSTIN,TX 78712, USA. NR 17 TC 60 Z9 62 U1 0 U2 5 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 APR 1 PY 1993 VL 73 IS 7 BP 3525 EP 3530 DI 10.1063/1.352958 PG 6 WC Physics, Applied SC Physics GA KV031 UT WOS:A1993KV03100059 ER PT J AU DUKOWICZ, JK SMITH, RD MALONE, RC AF DUKOWICZ, JK SMITH, RD MALONE, RC TI A REFORMULATION AND IMPLEMENTATION OF THE BRYAN-COX-SEMTNER OCEAN MODEL ON THE CONNECTION MACHINE SO JOURNAL OF ATMOSPHERIC AND OCEANIC TECHNOLOGY LA English DT Article AB Certain aspects of the Semtner-Chervin version of the Bryan-Cox-Semtner global ocean model are reformulated for improved efficiency on parallel computer architectures and on the Connection Machine CM-2 in particular. These changes involve (a) the switch from a streamfunction to a surface pressure formulation in the barotropic equations, (b) the splitting off of the Coriolis terms from the barotropic equations to produce a symmetric surface pressure equation, which then permits (c) the use of a preconditioned conjugate-gradient method for the solution of this equation. The switch to a surface pressure formulation (a) eliminates global equations associated with island boundary conditions and therefore improves performance as well as allows an unlimited number of islands, (b) reduces sensitivity to rapidly varying bottom topography and therefore obviates the need for smoothing the topography, and (c) makes the surface pressure a prognostic variable, thus potentially making it easier to assimilate surface altimetry data. Care is taken to retain the energetic consistency built into the original model. The nine-point operator for the pressure equation is found necessary to maintain energy consistency, in contrast to the streamfunction formulation where both nine-point and five-point operators are usable. Computational results closely resemble those of the original model, but with significantly improved performance. The barotropic part of the calculations in the surface pressure formulation is nearly three times faster than in the streamfunction formulation, and the full calculation involving both barotropic and baroclinic parts is nearly two times faster. These changes are described and details of the performance of the new formulation on the CM-2 are given. RP DUKOWICZ, JK (reprint author), LOS ALAMOS NATL LAB,DIV THEORET,T3 GRP,B216,LOS ALAMOS,NM 87545, USA. NR 0 TC 67 Z9 69 U1 0 U2 4 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0739-0572 J9 J ATMOS OCEAN TECH JI J. Atmos. Ocean. Technol. PD APR PY 1993 VL 10 IS 2 BP 195 EP 208 DI 10.1175/1520-0426(1993)010<0195:ARAIOT>2.0.CO;2 PG 14 WC Engineering, Ocean; Meteorology & Atmospheric Sciences SC Engineering; Meteorology & Atmospheric Sciences GA LM204 UT WOS:A1993LM20400005 ER PT J AU WOS, L AF WOS, L TI THE PROBLEM OF SELECTING AN APPROACH BASED ON PRIOR SUCCESS SO JOURNAL OF AUTOMATED REASONING LA English DT Article DE CHOICE OF APPROACH; UNSOLVED RESEARCH PROBLEM AB This article is the twenty-sixth of a series of articles discussing various open research problems in automated reasoning. The problem posed for research asks one to find criteria for choosing from among previously answered questions a question that dictates the approach to take for attacking the problem of current interest. Especially because the better automated reasoning programs often offer a wide range of choices for representation, inference rule, and strategy, a solution to the proposed problem would materially reduce the difficulty of using these powerful aids for research. C1 ARGONNE NATL LAB,ARGONNE,IL 60439. NR 6 TC 0 Z9 0 U1 0 U2 0 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0168-7433 J9 J AUTOM REASONING JI J. Autom. Reasoning PD APR PY 1993 VL 10 IS 2 BP 283 EP 284 DI 10.1007/BF00881839 PG 2 WC Computer Science, Artificial Intelligence SC Computer Science GA MH623 UT WOS:A1993MH62300007 ER PT J AU MA, D COOK, DN OBRIEN, DA HEARST, JE AF MA, D COOK, DN OBRIEN, DA HEARST, JE TI ANALYSIS OF THE PROMOTER AND REGULATORY SEQUENCES OF AN OXYGEN-REGULATED BCH OPERON IN RHODOBACTER-CAPSULATUS BY SITE-DIRECTED MUTAGENESIS SO JOURNAL OF BACTERIOLOGY LA English DT Article ID RHODOPSEUDOMONAS-CAPSULATA; GENE-EXPRESSION; CAROTENOID BIOSYNTHESIS; NUCLEOTIDE-SEQUENCE; R-CAPSULATA; BACTERIOCHLOROPHYLL; PHOTOSYNTHESIS; ORGANIZATION; POLYPEPTIDES; PROTEINS AB The biosynthesis of pigments (carotenoids and bacteriochlorophylls) in the photosynthetic bacterium Rhodobacter capsulatus is regulated by the oxygen concentration in the environment. However, the mechanism of this regulation has remained obscure. In this study, transcriptional fusions of the bchCXYZ promoter region to lacZ were used to identify the promoter and regulatory sequences governing transcription of these bacteriochlorophyll biosynthesis genes. The promoter region was identified in vivo by making deletions and site-directed mutations. The 50 bp upstream of the promoter region was shown to be required for the oxygen-dependent transcriptional regulation of bchCXYZ. A previously described palindrome sequence is also likely involved in the regulation. A gel mobility shift assay further defined the interaction of transcription regulators with these DNA sequence elements in vitro and demonstrated that a DNA-protein complex is formed at this promoter region. Since the suggested promoter sequence and the palindrome sequence are found upstream of several other bch and crt operons, these sequences may be responsible for regulating oxygen-dependent pigment biosynthesis at the level of transcription in R. capsulatus. In addition, these cis-acting DNA elements are not found upstream of puh and puf operons, which encode the structural polypeptides of the reaction center and light-harvesting I complexes. This observation supports the model of different regulatory mechanisms for the pigment biosynthesis enzymes and structural polypeptides required for the production of the photosynthetic apparatus. C1 UNIV CALIF BERKELEY,DEPT CHEM,BERKELEY,CA 94720. LAWRENCE BERKELEY LAB,DIV STRUCT BIOL,BERKELEY,CA 94720. FU NIGMS NIH HHS [GM 30786] NR 29 TC 45 Z9 46 U1 0 U2 1 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 APR PY 1993 VL 175 IS 7 BP 2037 EP 2045 PG 9 WC Microbiology SC Microbiology GA KU490 UT WOS:A1993KU49000021 PM 8458846 ER PT J AU LOPEZ, P LACKS, SA AF LOPEZ, P LACKS, SA TI A BIFUNCTIONAL PROTEIN IN THE FOLATE BIOSYNTHETIC-PATHWAY OF STREPTOCOCCUS-PNEUMONIAE WITH DIHYDRONEOPTERIN ALDOLASE AND HYDROXYMETHYLDIHYDROPTERIN PYROPHOSPHOKINASE ACTIVITIES SO JOURNAL OF BACTERIOLOGY LA English DT Article ID SYNTHETASE-DIHYDROFOLATE SYNTHETASE; COLI FOLC GENE; DIHYDROPTEROATE SYNTHASE; RNA-POLYMERASE; DNA-SEQUENCE; EXPRESSION; PRODUCT; CLONING; ENZYME AB A protein encoded by sulD, one of four genes in a previously cloned folate biosynthetic operon of Streptococcus pneumoniae, had been shown to harbor 6-hydroxymethyl-7,8-dihydropterin pyrophosphokinase activity. This SulD protein was purified and shown now to harbor also dihydroneopterin aldolase activity. The bifunctional protein therefore catalyzes two successive steps in folate biosynthesis. The aldolase activity can be ascribed to the N-terminal domain of the SulD polypeptide, and the pyrophosphokinase activity can be ascribed to the C-terminal domain. Homologs of the dihydroneopterin aldolase domain were identified in other species, in one of which the domain was encoded as a separate polypeptide. The native SulD protein is a trimer or tetramer of a 31-kDa subunit, and it dissociated reversibly after purification. Dihydroneopterin aldolase activity required the multimeric protein, whereas pyrophosphokinase was expressed by the monomeric form. With purified SulD, the amount of 6-hydroxymethyl-7,8-dihydropterin product formed by the aldolase was proportional to the fourth power of the enzyme concentration, as expected for a reversibly dissociating tetramer. By identifying the gene encoding dihydroneopterin aldolase, this work extends our understanding of the molecular basis of the folate biosynthetic system common to many organisms. C1 BROOKHAVEN NATL LAB,DEPT BIOL,UPTON,NY 11973. CSIC,CTR INVEST BIOL,E-28006 MADRID,SPAIN. RI Lopez Garcia, Paloma/L-1583-2014 OI Lopez Garcia, Paloma/0000-0001-8755-8952 FU NIAID NIH HHS [AI14885]; NIGMS NIH HHS [GM29721] NR 20 TC 28 Z9 30 U1 0 U2 2 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 APR PY 1993 VL 175 IS 8 BP 2214 EP 2220 PG 7 WC Microbiology SC Microbiology GA KX336 UT WOS:A1993KX33600007 PM 8385663 ER PT J AU BURKE, DH ALBERTI, M HEARST, JE AF BURKE, DH ALBERTI, M HEARST, JE TI THE RHODOBACTER-CAPSULATUS CHLORIN REDUCTASE-ENCODING LOCUS, BCHA, CONSISTS OF 3 GENES, BCHX, BCHY, AND BCHZ SO JOURNAL OF BACTERIOLOGY LA English DT Article ID BACTERIOCHLOROPHYLL BIOSYNTHESIS; RHODOPSEUDOMONAS-CAPSULATA; TRANSLATION INITIATION; NUCLEOTIDE-SEQUENCE; ESCHERICHIA-COLI; L-SUBUNIT; CLUSTER; ORGANIZATION; SPHAEROIDES; NITROGENASE AB The bchA locus of Rhodobacter capsulatus codes for the chlorin reductase enzyme in the bacteriochlorophyll synthesis pathway. Previous work has suggested that this locus might encompass a single gene. We have sequenced the bchA locus and found it to contain three coding segments, which we designate bchX, bchY, and bchZ. Each coding segment contains its own translational initiation sequence and follows codon utilization patterns consistent with those of previously published R. capsulatus genes. When various regions of the bchA locus and flanking sequences were subcloned into an expression vector and expressed in Escherichia coli, the three coding segments were all expressed as separate peptides. Finally, conservation of amino acid sequences between bchX and a subunit of the protochlorophyllide reductase (bchL, 34% identity) and the nitrogenase Fe protein (nifH, 30 to 37% identity) suggests structural and mechanistic commonalities among all three proteins. C1 UNIV CALIF BERKELEY,DEPT CHEM,BERKELEY,CA 94720. LAWRENCE BERKELEY LAB,DIV STRUCT BIOL,BERKELEY,CA 94720. FU NIGMS NIH HHS [GM 30786] NR 33 TC 40 Z9 49 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 APR PY 1993 VL 175 IS 8 BP 2407 EP 2413 PG 7 WC Microbiology SC Microbiology GA KX336 UT WOS:A1993KX33600031 PM 8468299 ER PT J AU BURKE, DH ALBERTI, M HEARST, JE AF BURKE, DH ALBERTI, M HEARST, JE TI BCHFNBH BACTERIOCHLOROPHYLL SYNTHESIS GENES OF RHODOBACTER-CAPSULATUS AND IDENTIFICATION OF THE 3RD SUBUNIT OF LIGHT-INDEPENDENT PROTOCHLOROPHYLLIDE REDUCTASE IN BACTERIA AND PLANTS SO JOURNAL OF BACTERIOLOGY LA English DT Article ID RHODOPSEUDOMONAS-CAPSULATA; CHLOROPLAST GENOME; NUCLEOTIDE-SEQUENCE; R-CAPSULATA; BIOSYNTHESIS; ORGANIZATION; CLUSTER; DNA; PHOTOSYNTHESIS; SPHAEROIDES AB We present the nucleotide and deduced amino acid sequences of four contiguous bacteriochlorophyll synthesis genes from Rhodobacter capsulatus. Three of these genes code for enzymes which catalyze reactions common to the chlorophyll synthesis pathway and therefore are likely to be found in plants and cyanobacteria as well. The pigments accumulated in strains with physically mapped transposon insertion mutations are analyzed by absorbance and fluorescence spectroscopy, allowing us to assign the genes as bchF, bchN, bchB, and bchH, in that order. bchF encodes a bacteriochlorophyll a-specific enzyme that adds water across the 2-vinyl group. The other three genes are required for portions of the pathway that are shared with chlorophyll synthesis, and they were expected to be common to both pathways. bchN and bchB are required for protochlorophyllide reduction in the dark (along with bchL), a reaction that has been observed in all major groups of photosynthetic organisms except angiosperms, where only the light-dependent reaction has been clearly established. The purple bacterial and plant enzymes show 35% identity between the amino acids coded by bchN and chlN (gidA) and 49% identity between the amino acids coded by bchL and chlL (frxC). Furthermore, bchB is 33% identical to ORF513 from the Marchantia polymorpha chloroplast. We present arguments in favor of the probable role of ORF513 (chlB) in protochlorophyllide reduction in the dark. The further similarities of all three subunits of protochlorophyllide reductase and the three subunits of chlorin reductase in bacteriochlorophyll synthesis suggest that the two reductase systems are derived from a common ancestor. C1 UNIV CALIF BERKELEY,DEPT CHEM,BERKELEY,CA 94720. LAWRENCE BERKELEY LAB,DIV STRUCT BIOL,BERKELEY,CA 94720. FU NIGMS NIH HHS [GM 30786] NR 46 TC 61 Z9 69 U1 0 U2 3 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 APR PY 1993 VL 175 IS 8 BP 2414 EP 2422 PG 9 WC Microbiology SC Microbiology GA KX336 UT WOS:A1993KX33600032 PM 8385667 ER PT J AU FEE, JA YOSHIDA, T SURERUS, KK MATHER, MW AF FEE, JA YOSHIDA, T SURERUS, KK MATHER, MW TI CYTOCHROME-CAA3 FROM THE THERMOPHILIC BACTERIUM THERMUS-THERMOPHILUS - A MEMBER OF THE HEME-COPPER OXIDASE SUPERFAMILY SO JOURNAL OF BIOENERGETICS AND BIOMEMBRANES LA English DT Article DE THERMUS CYTOCHROME-CAA3 PROTEIN SEQUENCES; METAL COORDINATION; CYANIDE BINDING; STRUCTURAL MODEL ID C-OXIDASE; BRADYRHIZOBIUM-JAPONICUM; TERMINAL OXIDASE; ESCHERICHIA-COLI; PROTON-PUMP; SUBUNIT-III; PARACOCCUS-DENITRIFICANS; RESPIRATORY PROTEINS; NUCLEOTIDE-SEQUENCE; PURIFICATION AB The subject of this short review is the cytochrome c oxidase (caa3) from the thermophilic bacterium Thermus thermophilus. First, some of the extensive physical and enzymological results obtained with this enzyme are reviewed, and two experiments are described, involving isotope substitutions in combination with Mossbauer and ENDOR spectroscopies, which have provided novel insight into the active sites of the enzyme. Second, we summarize recent molecular genetic work showing that Thermus cytochrome caa3 is a bona fide member of the superfamily of heme-copper oxidases. Finally, we present a rough three-dimensional model and speculate about certain features of the metal-binding sites. RP FEE, JA (reprint author), LOS ALAMOS NATL LAB,DIV ISOTOPE & NUCL CHEM,BIOCHEM & SPECT GRP,LOS ALAMOS,NM 87545, USA. FU NCRR NIH HHS [RR02231]; NIGMS NIH HHS [GM35342] NR 58 TC 25 Z9 25 U1 0 U2 4 PU PLENUM PUBL CORP PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 SN 0145-479X J9 J BIOENERG BIOMEMBR JI J. Bioenerg. Biomembr. PD APR PY 1993 VL 25 IS 2 BP 103 EP 114 DI 10.1007/BF00762852 PG 12 WC Biophysics; Cell Biology SC Biophysics; Cell Biology GA KZ701 UT WOS:A1993KZ70100004 PM 8389743 ER PT J AU WOODRUFF, WH AF WOODRUFF, WH TI COORDINATION DYNAMICS OF HEME-COPPER OXIDASES - THE LIGAND SHUTTLE AND THE CONTROL AND COUPLING OF ELECTRON-TRANSFER AND PROTON TRANSLOCATION SO JOURNAL OF BIOENERGETICS AND BIOMEMBRANES LA English DT Article ID CYTOCHROME-C-OXIDASE; RESONANCE RAMAN-SPECTROSCOPY; INFRARED-SPECTROSCOPY; ESCHERICHIA-COLI; DIOXYGEN; BINDING; INTERMEDIATE; MECHANISM; OXIDATION; OXYGEN AB Results are presented which, taken with evidence developed by others, suggest a general mechanism for the entry and binding of exogenous ligands (including O2) at the ''binuclear site'' (CuBFea3) of the heme-copper oxidases. The mechanism includes a ''ligand shuttle'' wherein the obligatory waystation for incoming ligands is Cu(B) and the binding of exogenous ligands at this site triggers the exchange and displacement of endogenous ligands at Fe(a3). It is suggested that these ligand shuttle reactions might be functionally important in providing a coupling mechanism for electron transfer and proton translocation. Scenarios as to how this might happen are delineated. RP WOODRUFF, WH (reprint author), LOS ALAMOS NATL LAB,SPECT & BIOCHEM GRP,INC-14,MAIL STOP C-345,LOS ALAMOS,NM 87545, USA. FU NIDDK NIH HHS [DK36263] NR 51 TC 118 Z9 118 U1 0 U2 2 PU PLENUM PUBL CORP PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 SN 0145-479X J9 J BIOENERG BIOMEMBR JI J. Bioenerg. Biomembr. PD APR PY 1993 VL 25 IS 2 BP 177 EP 188 DI 10.1007/BF00762859 PG 12 WC Biophysics; Cell Biology SC Biophysics; Cell Biology GA KZ701 UT WOS:A1993KZ70100011 PM 8389750 ER PT J AU PRADEEP, T NIU, B SHIRLEY, DA AF PRADEEP, T NIU, B SHIRLEY, DA TI PHOTOELECTRON-SPECTROSCOPY OF RARE-GAS DIMERS REVISITED - VIBRATIONALLY RESOLVED PHOTOELECTRON-SPECTRUM OF ARGON DIMER SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID POTENTIAL-ENERGY CURVES; PHOTOFRAGMENT SPECTROSCOPY; GROUND-STATE; IONIZATION; CLUSTERS; IONS; XE2; PHOTOIONIZATION; MOLECULES; XE-2(+) AB Photoelectron spectra of rare gas dimers Ar2, Kr2, and Xe2 have been measured using the He I radiation at 584 A with a resolution of 13 meV. All the six ionic states in the He I region have been resolved for the first time, including some of the purely repulsive states. Ionization energies are presented to an accuracy less-than-or-equal-to 0.003 eV. Dissociation energies (D0) of the ionic states are calculated using the best estimate adiabatic ionization energies. The D2SIGMA1+/2g states of all the dimers are weakly bound, contrary to an earlier theoretical prediction. Part of the vibrational structure of two of the electronic states of Ar2 has been resolved. For the A2SIGMA1+/2u state, as many as 14 vibrational excitations are observed. These excitations are assigned to transitions to the higher vibrational levels of v = 32-45. For the B2PI3/2g state, three vibrational structures are resolved and are assigned to v = 2-4 of the ionic state. Accurate values of the spectroscopic constants of these states are presented. The present values are compared with the values available in the literature. The D(e) values for the A2SIGMA1/2u+ and the B2PI3/2g states are estimated to be 1.361 and 0.104 eV, respectively. RP PRADEEP, T (reprint author), LAWRENCE BERKELEY LAB,DIV CHEM SCI,BERKELEY,CA 94720, USA. NR 21 TC 31 Z9 31 U1 1 U2 11 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 APR 1 PY 1993 VL 98 IS 7 BP 5269 EP 5275 DI 10.1063/1.464926 PG 7 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA KV997 UT WOS:A1993KV99700013 ER PT J AU LEQUERE, F GRAY, SK AF LEQUERE, F GRAY, SK TI QUANTUM DYNAMICS OF VANDERWAALS CLUSTERS - MODEL RESULTS FOR HE2CL2 AND NE2CL2 FRAGMENTATION SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID VIBRATIONAL PREDISSOCIATION DYNAMICS; COLLISION-INDUCED DISSOCIATION; PHOTO-DISSOCIATION; WAVE-PACKET; ENERGY; MOLECULES; IODINE; SPECTROSCOPY; COMPLEXES; HELIUM AB Wave packet calculations are carried out on a three degrees of freedom model for the fragmentation dynamics of X2Cl2 van der Waals clusters, with X=He and Ne. The model allows Cl2 to vibrate, but not rotate, with the X atoms restricted to motion in a plane perpendicular to and bisecting the Cl2 bond. The (X, Cl2 center, X) angle theta is also held fixed. Both X+XCl2 and 2X+Cl2 Continua are explicitly included. Results for He2Cl2(v') vibrational predissociation to 2He + Cl2 (v(F)), with 7 less-than-or-equal-to v' less-than-or-equal-to 13 are presented, and found to be in qualitative accord with experiment. In particular, even though products Cl2(v(F) = v' - 1) are energetically allowed for all v' in the range, almost-equal-to 90% of the products are estimated to be in v(F) =v'-2. Inspection of the wave packet confirms that a sequential mechanism He2Cl2(v') --> He+HeCl2(v'-1) --> 2He+Cl2(v(F) = v'-2) is operative. Theoretical lifetimes for Ne2Cl2 (v') --> 2Ne + Cl2 (v(F)) are in rough agreement with experimental results, where available. The Cl2(v(F)) product distributions for Ne2Cl2(v') are estimated to be similar to those obtained for He2Cl2(v'), with v(F) = v'-2 products being dominant over the entire v' range. This is only partly in accord with experiment, which points to both v(F) = v'-1 and v(F) = v'-2 products being important when the v'-1 product channel is open (for v' less-than-or-equal-to 10 in this case). We show that variation in theta can enhance production of v(F) = v'-1 products, and that this effect should be most important for Ne2Cl2(v'). RP LEQUERE, F (reprint author), ARGONNE NATL LAB,DIV CHEM,THEORET CHEM GRP,ARGONNE,IL 60439, USA. NR 35 TC 33 Z9 33 U1 0 U2 0 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 APR 1 PY 1993 VL 98 IS 7 BP 5396 EP 5407 PG 12 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA KV997 UT WOS:A1993KV99700026 ER PT J AU BUTENHOFF, TJ ROHLFING, EA AF BUTENHOFF, TJ ROHLFING, EA TI LASER-INDUCED GRATINGS IN FREE JETS .1. SPECTROSCOPY OF PREDISSOCIATING NO2 SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID FLUORESCENCE EXCITATION SPECTRUM; ROTATIONALLY COOLED NO2 AB We use two-color laser-induced grating spectroscopy (LIGS) to obtain double-resonance, absorptionlike spectra of jet-cooled NO2 below and above the threshold for predissociation at 398 nm. The grating-laser frequency is tuned through the dissociation threshold while the probe-laser frequency is fixed to a specific rotational line of an isolated, cold vibronic band well below threshold. The signal beam diffracts off the ground state depletion grating formed when the grating laser excites a transition out of the rotational level selected by the probe laser. The above-threshold spectra observed for NO2 indicate that, under collision-free conditions in the free jet, the LIGS spectrum maps the square of the absorption spectrum. We determine predissociation lifetimes from LIGS linewidths and discuss the temporal decay of the induced grating as a function of its orientation with respect to the jet axis. Finally, we consider the effects of phase matching on two-color LIGS in the forward geometry and derive expressions for the variation in signal-beam angle and for the phase matching bandwidths for experiments in which the frequency of either the grating or probe laser is scanned. C1 SANDIA NATL LABS,COMBUST RES FACIL,LIVERMORE,CA 94551. NR 19 TC 91 Z9 91 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 APR 1 PY 1993 VL 98 IS 7 BP 5460 EP 5468 DI 10.1063/1.464895 PG 9 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA KV997 UT WOS:A1993KV99700032 ER PT J AU BUTENHOFF, TJ ROHLFING, EA AF BUTENHOFF, TJ ROHLFING, EA TI LASER-INDUCED GRATINGS IN FREE JETS .2. PHOTODISSOCIATION DYNAMICS VIA PHOTOFRAGMENT TRANSIENT GRATINGS SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID NO2; FLUORESCENCE; VELOCITY; SPECTRA AB We describe the use of photofragment transient gratings to measure populations, velocities, and translational anisotropies of nascent, state-selected photofragments. This technique is a variant of two-color laser-induced grating spectroscopy (LIGS); scanning the probe laser gives spectra that reveal fragment-state populations and scanning the grating laser, with the probe laser monitoring a specific fragment state, produces photofragment excitation (PHOFEX) spectra. The temporal behavior of the photofragment grating is used to determine speeds and translational anisotropies of the photofragments. We have demonstrated the photofragment grating method on the NO(2PI1/2, v'' = 0, J'') fragments produced from the near-threshold photolysis of jet-cooled NO2. The grating PHOFEX spectrum yields the threshold for production of NO (2PI1/2, v'' = 0, J'' = 0.5, e) + O(3P2) from NO2 (N'' = 0) as 25 128.5 +/- 0.2 cm-1. For-photolysis at 126 cm-1 above threshold, the NO rotational distribution obtained from the probe spectrum is in good agreement with that determined from a LIF spectrum recorded simultaneously. In addition, analysis of the grating decays for state-selected NO fragments gives their speeds and anisotropies; the speeds are in excellent agreement with the known values, even for fragments with as little as 7 cm-1 of translational energy. C1 SANDIA NATL LABS,COMBUST RES FACIL,LIVERMORE,CA 94551. NR 23 TC 71 Z9 71 U1 0 U2 2 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 APR 1 PY 1993 VL 98 IS 7 BP 5469 EP 5476 DI 10.1063/1.464896 PG 8 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA KV997 UT WOS:A1993KV99700033 ER PT J AU TRUHLAR, DG SCHENTER, GK GARRETT, BC AF TRUHLAR, DG SCHENTER, GK GARRETT, BC TI INCLUSION OF NONEQUILIBRIUM CONTINUUM SOLVATION EFFECTS IN VARIATIONAL TRANSITION-STATE THEORY SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID CHEMICAL-REACTION RATES; POLAR-SOLVENTS; RATE-CONSTANT; SN2 REACTION; REACTION COORDINATE; CHARGE-TRANSFER; STRING MODEL; DYNAMICS; MOLECULES; FIELDS AB We define a general set of effective solvent coordinates for reactions in solution that should be especially well suited for polar solvents. No specific functional form is assumed for the variation of charges with motions along or orthogonal to the reaction coordinate, and as a consequence the formalism allows the treatment of arbitrary reaction types using electronic structure calculations for the solute charge distribution. A critical assumption of the theory is that the nonequilibrium polarization field may be represented in terms of the adiabatic polarization fields that arise for linear geometric displacements. The results are combined with the Cartesian-coordinate canonical variational transition state theory presented previously to provide a general method for including both equilibrium and nonequilibrium solvation effects of a nondissipative, continuum-dielectric solvent in practical calculations of rate constants. C1 UNIV MINNESOTA, INST SUPERCOMP, MINNEAPOLIS, MN 55455 USA. PACIFIC NW LAB, MOLEC SCI RES CTR, RICHLAND, WA 99352 USA. RP UNIV MINNESOTA, DEPT CHEM, MINNEAPOLIS, MN 55455 USA. RI Garrett, Bruce/F-8516-2011; Schenter, Gregory/I-7655-2014; Truhlar, Donald/G-7076-2015 OI Schenter, Gregory/0000-0001-5444-5484; Truhlar, Donald/0000-0002-7742-7294 NR 70 TC 62 Z9 62 U1 1 U2 2 PU AMER INST PHYSICS PI MELVILLE PA 1305 WALT WHITMAN RD, STE 300, MELVILLE, NY 11747-4501 USA SN 0021-9606 EI 1089-7690 J9 J CHEM PHYS JI J. Chem. Phys. PD APR 1 PY 1993 VL 98 IS 7 BP 5756 EP 5770 DI 10.1063/1.464868 PG 15 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA KV997 UT WOS:A1993KV99700059 ER PT J AU BAILEY, JK BRINKER, CJ MECARTNEY, ML AF BAILEY, JK BRINKER, CJ MECARTNEY, ML TI GROWTH MECHANISMS OF IRON-OXIDE PARTICLES OF DIFFERING MORPHOLOGIES FROM THE FORCED HYDROLYSIS OF FERRIC-CHLORIDE SOLUTIONS SO JOURNAL OF COLLOID AND INTERFACE SCIENCE LA English DT Article ID HYDROUS OXIDES; HEMATITE; SOLS C1 SANDIA NATL LABS,DEPT 1846,ALBUQUERQUE,NM 87185. UNIV CALIF IRVINE,DEPT MECH ENGN,DIV MAT,IRVINE,CA 92717. NR 27 TC 144 Z9 146 U1 5 U2 26 PU ACADEMIC PRESS INC JNL-COMP SUBSCRIPTIONS PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 SN 0021-9797 J9 J COLLOID INTERF SCI JI J. Colloid Interface Sci. PD APR PY 1993 VL 157 IS 1 BP 1 EP 13 DI 10.1006/jcis.1993.1150 PG 13 WC Chemistry, Physical SC Chemistry GA KV170 UT WOS:A1993KV17000001 ER PT J AU GRATZ, AJ HILLNER, PE AF GRATZ, AJ HILLNER, PE TI POISONING OF CALCITE GROWTH VIEWED IN THE ATOMIC FORCE MICROSCOPE (AFM) SO JOURNAL OF CRYSTAL GROWTH LA English DT Note ID CRYSTAL-GROWTH; ORTHO-PHOSPHATE; CRYSTALLIZATION; RECOGNITION; INHIBITION; IMPURITIES; MAGNESIUM AB We Present real-time, in situ atomic force microscope (AFM) observations of poisoning of calcite. This technique allows direct observation of chemically induced changes in the velocity and morphology of monomolecular steps less than 1 nm high, and direct imaging of adsorbates. Phosphonates and phosphates attach directly but reversibly onto growth steps above a threshold concentration, and further growth is inhibited until the poison is removed. In contrast, magnesium ions and NaCl have much weaker effects on growth. All additives studied changed step shapes, and HEDP and SHMP modify re-growth morphology, leading to spicular growth on rhomb faces. C1 UNIV CALIF SANTA BARBARA,DEPT PHYS,SANTA BARBARA,CA 93106. RP GRATZ, AJ (reprint author), LAWRENCE LIVERMORE NATL LAB,INST GEOPHYS & PLANETARY PHYS,LIVERMORE,CA 94550, USA. NR 28 TC 74 Z9 79 U1 4 U2 17 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-0248 J9 J CRYST GROWTH JI J. Cryst. Growth PD APR PY 1993 VL 129 IS 3-4 BP 789 EP 793 DI 10.1016/0022-0248(93)90515-X PG 5 WC Crystallography; Materials Science, Multidisciplinary; Physics, Applied SC Crystallography; Materials Science; Physics GA KY530 UT WOS:A1993KY53000046 ER PT J AU DAWSON, PR FOLLANSBEE, PS AF DAWSON, PR FOLLANSBEE, PS TI THE VARIABLE THRESHOLD ROD EXPERIMENT - A COMPARISON OF MEASURED AND COMPUTED DEFORMATIONS SO JOURNAL OF ENGINEERING MATERIALS AND TECHNOLOGY-TRANSACTIONS OF THE ASME LA English DT Article ID KINETICS AB A novel experiment has been developed to induce inhomogeneous deformations under simple extension boundary conditions. By appropriate prior cold working of stock material and fabrication of test specimens with tailored dimensions, the location of the deformation zones along the gage length of tensile specimens was controlled. By design, the deformations were chosen to concentrate either toward the harder or softer ends of the specimens. The experiment provides a sensitive test to judge the ability of constitutive models to replicate the behavior of metals undergoing inhomogeneous deformation. A comparison of experimental results with simulated response using an isotropic state variable model is presented. C1 LANL,LOS ALAMOS,NM 87595. RP DAWSON, PR (reprint author), CORNELL UNIV,SIBLEY SCH MECH & AEROSP ENGN,ITHACA,NY 14853, USA. NR 11 TC 2 Z9 2 U1 0 U2 0 PU ASME-AMER SOC MECHANICAL ENG PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 SN 0094-4289 J9 J ENG MATER-T ASME JI J. Eng. Mater. Technol.-Trans. ASME PD APR PY 1993 VL 115 IS 2 BP 211 EP 219 DI 10.1115/1.2904209 PG 9 WC Engineering, Mechanical; Materials Science, Multidisciplinary SC Engineering; Materials Science GA KZ635 UT WOS:A1993KZ63500009 ER PT J AU SUTER, GW LUXMOORE, RJ SMITH, ED AF SUTER, GW LUXMOORE, RJ SMITH, ED TI COMPACTED SOIL BARRIERS AT ABANDONED LANDFILL SITES ARE LIKELY TO FAIL IN THE LONG-TERM SO JOURNAL OF ENVIRONMENTAL QUALITY LA English DT Review ID ROOT-GROWTH; LINER AB At innumerable sites in the USA and around the world, buried waste has been isolated from the environment by barriers constructed entirely or in part of compacted soil. The chief concern in barrier design has been to isolate the waste in the short term by preventing movement of water into and through the waste. However, in the long term a variety of mechanisms can act to compromise this isolation. The mechanisms of long-term failure include initial flaws in barrier construction, shrink-swell cycles, freeze-thaw cycles, erosion, subsidence, root intrusion, and animal intrusion. Evidence for action of all of these mechanisms is summarized. The likelihood of long-term failure suggests that either perpetual care must be provided for buried hazardous wastes, or the waste sites must be designed to withstand long-term threats to barrier integrity. RP SUTER, GW (reprint author), OAK RIDGE NATL LAB, DIV ENVIRONM SCI, POB 2008, OAK RIDGE, TN 37831 USA. RI Smith, Ellen/B-9432-2012 NR 69 TC 41 Z9 44 U1 0 U2 9 PU AMER SOC AGRONOMY PI MADISON PA 677 S SEGOE RD, MADISON, WI 53711 USA SN 0047-2425 EI 1537-2537 J9 J ENVIRON QUAL JI J. Environ. Qual. PD APR-JUN PY 1993 VL 22 IS 2 BP 217 EP 226 PG 10 WC Environmental Sciences SC Environmental Sciences & Ecology GA LE947 UT WOS:A1993LE94700001 ER PT J AU CARLSON, CL ADRIANO, DC AF CARLSON, CL ADRIANO, DC TI ENVIRONMENTAL IMPACTS OF COAL COMBUSTION RESIDUES SO JOURNAL OF ENVIRONMENTAL QUALITY LA English DT Review ID ASH-AMENDED SOIL; AUSTRALIAN FLY ASHES; ELEMENTAL CONTENT; INORGANIC CONSTITUENTS; MICROBIAL ACTIVITY; TRACE-ELEMENTS; PLANT UPTAKE; BOTTOM ASH; SELENIUM; DISPOSAL AB Coal combustion residues account for 90% of all fossil fuel combustion wastes produced in the USA. It is Projected that by the year 2000 more than 150 million t of these materials will be produced in the USA each year. Presently, only about 20% of these wastes are utilized, with the remainder deposited in landfills or surface impoundments. This article reviews the information available concerning the environmental impacts associated with the disposal or utilization of coal combustion residues. The majority of the information available in the literature concerns the impacts of fly and bottom ashes; other coal combustion wastes have not received much attention. The major potential impacts of ash disposal on terrestrial ecosystems include: leaching of potentially toxic substances into soils and groundwater; reductions in plant establishment and growth due primarily to adverse chemical characteristics of the ash; changes in the elemental composition of vegetation growing on the ash; and increased mobility and accumulation of potentially toxic elements throughout the food chain. Ash disposal in landfills and settling ponds can influence adjacent aquatic ecosystems directly, through inputs of ash basin effluent and surface runoff, and indirectly, through seepage and groundwater contamination. Major impacts are generally associated with changes in water chemistry, including changes in pH and concentrations of potentially toxic elements. Using ash as a soil amendment can improve soil texture and water-holding capacity, increase soil pH, and enhance soil fertility. However, it may also result in excessive soluble salt concentrations, excess B, and increased concentrations of other potentially toxic trace elements; reduction in the concentrations and/or availability of soil N and P; elemental imbalances due to excessively high pH; and cementation or compaction of soil. Scrubber sludge and fluidized bed combustion waste may be used as soil amendments as well, but also may create problems due to high alkalinity and high salinity. C1 UNIV GEORGIA,DIV BIOGEOCHEM,SAVANNAH RIVER ECOL LAB,AIKEN,SC 29802. RP CARLSON, CL (reprint author), BOWLING GREEN STATE UNIV,RES SERV OFF,BOWLING GREEN,OH 43403, USA. NR 161 TC 316 Z9 330 U1 13 U2 121 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 APR-JUN PY 1993 VL 22 IS 2 BP 227 EP 247 PG 21 WC Environmental Sciences SC Environmental Sciences & Ecology GA LE947 UT WOS:A1993LE94700002 ER PT J AU HOLDREN, GR STRICKLAND, TC SHAFFER, PW RYAN, PF RINGOLD, PL TURNER, RS AF HOLDREN, GR STRICKLAND, TC SHAFFER, PW RYAN, PF RINGOLD, PL TURNER, RS TI SENSITIVITY OF CRITICAL LOAD ESTIMATES FOR SURFACE WATERS TO MODEL SELECTION AND REGIONALIZATION SCHEMES SO JOURNAL OF ENVIRONMENTAL QUALITY LA English DT Article ID ACIDIC DEPOSITION; UNITED-STATES; ACIDIFICATION; CHEMISTRY; ECOSYSTEMS; STRATEGIES; RAIN AB A critical load is the amount of atmospheric pollutant that can be deposited on a sensitive ecosystem without causing measurable, longterm degradation in ecosystem form or function. We compare several methods for making critical load estimates of SO4 deposition to lakes; these methods are among those identified by participants in the United Nations-Economic Commission for Europe (UNECE) Convention on Long-Range Transboundary Air Pollution. The models were originally developed to address surface water acidification issues. Critical loads are computed here as the levels of deposition required to reduce surface water acid neutralizing capacities (ANC) from present values to either 25 mueq L-1 or 0 mueq L-1. These end points were selected to provide a common basis for comparing critical load values obtained from the various models, and are not intended to provide definitive critical load estimates. Using the amount of deposition required to decrease steady-state surface water ANC values from 25 to 0 mueq L-1, about 9 +/- 2 kgSO4 ha-1 yr-1 in the northeastern USA as a basis for comparison, we find that models make significantly different projections regarding ecosystem sensitivites to deposition. For lakes with critical load values in the range of current deposition in the Northeast (i.e., 18-56 kg SO4 ha-1 yr-1), model results differ by as much as 82 kg SO4 ha-1 yr-1. Differences in results are observed not only between models, but within models when slightly different approaches are used for estimating certain parameters. The interpretation of model results depends strongly on how systems are grouped regionally. While the results suggest that reductions in deposition from current levels would reduce adverse effects in sensitive lakes, the magnitude and timing of the reductions necessary and the determination of appropriate population end points are decisions that will ultimately be made by risk managers rather than risk assessors. C1 US EPA,ENVIRONM RES LAB,CORVALLIS,OR 97333. SCI APPLICAT INT CORP,OAK RIDGE,TN 37831. US EPA,WASHINGTON,DC 20012. OAK RIDGE NATL LAB,DIV ENVIRONM SCI,OAK RIDGE,TN 37831. OI Strickland, Timothy/0000-0001-6889-503X NR 32 TC 8 Z9 8 U1 0 U2 0 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 APR-JUN PY 1993 VL 22 IS 2 BP 279 EP 289 PG 11 WC Environmental Sciences SC Environmental Sciences & Ecology GA LE947 UT WOS:A1993LE94700008 ER PT J AU ZHONG, F ECKE, RE STEINBERG, V AF ZHONG, F ECKE, RE STEINBERG, V TI ROTATING RAYLEIGH-BENARD CONVECTION - ASYMMETRIC MODES AND VORTEX STATES SO JOURNAL OF FLUID MECHANICS LA English DT Article ID TURBULENT CONVECTION; BOUNDARY-LAYERS; FLUID LAYER; TEMPERATURE; STABILITY; VELOCITY; HELIUM; WATER AB We present optical shadowgraph flow visualization and heat transport measurements of Rayleigh-Benard convection with rotation about a vertical axis. The fluid, water with Prandtl number 6.4, is confined in a cylindrical convection cell with radius-to-height ratio GAMMA = 1. For dimensionless rotation rates 150 < OMEGA < 8800, the onset of convection occurs at critical Rayleigh numbers R(c)(OMEGA) much less than those predicted by linear stability analysis for a laterally infinite system and qualitatively consistent with finite-aspect-ratio, linear-stability calculations of Buell & Catton (1983). As in the calculations, the forward bifurcation at onset is to states of localized flow near the lateral walls with azimuthal periodicity of 3 < m < 8. These states precess in the rotating frame, contrary to the assumptions of Buell & Catton (1983) but in quantitative agreement with recent calculations of Goldstein et al. (1992), with a frequency that is finite at onset but goes to zero as Q goes to zero. At OMEGA = 2145 we find primary and secondary stability boundaries for states with m = 4, 5, 6, and 7. Further, we show that at higher Rayleigh number, there is a transition to a vortex state where the vortices form with the symmetry of the existing azimuthal periodicity of the sidewall state. Aperiodic, time-dependent heat transport begins for Rayleigh numbers at or slightly above the first appearance of vortices. Visualization of the formation and interactions of thermal vortices is presented, and the behaviour of the Nusselt number at high Rayleigh numbers is discussed. C1 LOS ALAMOS NATL LAB,DIV PHYS,LOS ALAMOS,NM 87545. LOS ALAMOS NATL LAB,CTR NONLINEAR STUDIES,LOS ALAMOS,NM 87545. RI Steinberg, Victor/B-3205-2009 NR 39 TC 91 Z9 91 U1 1 U2 10 PU CAMBRIDGE UNIV PRESS PI NEW YORK PA 40 WEST 20TH STREET, NEW YORK, NY 10011-4211 SN 0022-1120 J9 J FLUID MECH JI J. Fluid Mech. PD APR PY 1993 VL 249 BP 135 EP 159 DI 10.1017/S0022112093001119 PG 25 WC Mechanics; Physics, Fluids & Plasmas SC Mechanics; Physics GA KZ447 UT WOS:A1993KZ44700007 ER PT J AU FELDMAN, WC GOSLING, JT MCCOMAS, DJ PHILLIPS, JL AF FELDMAN, WC GOSLING, JT MCCOMAS, DJ PHILLIPS, JL TI EVIDENCE FOR ION JETS IN THE HIGH-SPEED SOLAR-WIND SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID RESONANT ACCELERATION; EXPLOSIVE EVENTS; MAGNETIC NETWORK; MINOR IONS; QUIET SUN; CORONA; RECONNECTION; HELIUM; 0.3-AU; WAVES AB Shapes of proton and al pha particle velocity distribution functions in the high-speed solar wind are examined for the time period from 1973 to 1987. Whereas enhanced high-energy extensions axe a near universal feature of the proton distributions, no such enhancements axe observed in alpha particle distributions. Such distributions are examined and documented in detail. An interpretation of this observation is presented in terms of a two-component model of coronal heating and acceleration. We suggest that a modest amount of heating results from the damping of waves, whereas additional heating and the bulk of the acceleration is associated with the direct conversion of magnetic energy flux to plasma convection and enthalpy flux through the process of magnetic reconnection. This model predicts that the ambient flow of plasma from coronal holes is characterized by a low-speed and a low-mass flux. In particular, the proton flux is insufficient to drag alpha particles out of the solar gravitational potential well. This should lead to a considerable enhancement of the helium abundance close to the Sun. Plasma jets rich in helium and accelerated by reconnection close to the Sun buffet the ambient plasma from below. The slow-moving ambient plasma is coupled to the faster-moving jets by Coulomb friction close to the Sun, and then through microinstabilities far from the Sun. The net effect of this interaction is a high-speed, double-streaming proton population and a single component, but faster alpha particle flow at large heliocentric distances. RP FELDMAN, WC (reprint author), LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545, USA. NR 51 TC 46 Z9 46 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0148-0227 J9 J GEOPHYS RES JI J. Geophys. Res-Space Phys. PD APR 1 PY 1993 VL 98 IS A4 BP 5593 EP 5605 DI 10.1029/92JA02260 PG 13 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA KW003 UT WOS:A1993KW00300004 ER PT J AU CHEN, SH KIVELSON, MG GOSLING, JT WALKER, RJ LAZARUS, AJ AF CHEN, SH KIVELSON, MG GOSLING, JT WALKER, RJ LAZARUS, AJ TI ANOMALOUS ASPECTS OF MAGNETOSHEATH FLOW AND OF THE SHAPE AND OSCILLATIONS OF THE MAGNETOPAUSE DURING AN INTERVAL OF STRONGLY NORTHWARD INTERPLANETARY MAGNETIC-FIELD SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID LATITUDE BOUNDARY-LAYER; KELVIN-HELMHOLTZ INSTABILITY; PLASMA OBSERVATIONS; DEPLETION; SURFACE; ISEE-1; WAVES AB On February 15, 1978, the orientation of the interplanetary magnetic field (IMF) remained steadily northward for more than 12 hours. The ISEE 1 and 2 spacecraft were located near apogee on the dawnside flank of the magnetotail. IMP 8 was almost symmetrically located in the magnetosheath on the dusk flank and IMP 7 was upstream in the solar wind. Using plasma and magnetic field data, we show that (1) the magnetosheath flow speed on the flanks of the magnetotail steadily exceeded the solar wind speed by 20%, (2) surface waves of approximately 5-min period and very nonsinusoidal waveform were persistently present on the dawn magnetopause and waves of similar period were present in the dusk magnetosheath, and (3) the magnetotail ceased to flare at an antisunward distance of 15 R(E). We propose that the acceleration of the magnetosheath flow is achieved by magnetic tension in the draped field configuration for northward IMF and that the reduction of tail flaring is consistent with a decreased amount of open magnetic flux and a larger standoff distance of the subsolar magnetopause. Results of a three-dimensional magnetohydrodynamic simulation support this phenomenological model. C1 UNIV CALIF LOS ANGELES,DEPT EARTH & SPACE SCI,LOS ANGELES,CA 90024. LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545. MIT,DEPT PHYS,CTR SPACE RES,CAMBRIDGE,MA 02139. RP CHEN, SH (reprint author), UNIV CALIF LOS ANGELES,INST GEOPHYS & PLANETARY PHYS,LOS ANGELES,CA 90024, USA. RI Kivelson, Margaret/I-9019-2012 OI Kivelson, Margaret/0000-0003-3859-8581 NR 36 TC 110 Z9 110 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0148-0227 J9 J GEOPHYS RES JI J. Geophys. Res-Space Phys. PD APR 1 PY 1993 VL 98 IS A4 BP 5727 EP 5742 DI 10.1029/92JA02263 PG 16 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA KW003 UT WOS:A1993KW00300015 ER PT J AU GOSLING, JT THOMSEN, MF BAME, SJ ELPHIC, RC AF GOSLING, JT THOMSEN, MF BAME, SJ ELPHIC, RC TI OBSERVATIONS OF RECONNECTION OF INTERPLANETARY AND LOBE MAGNETIC-FIELD LINES AT THE HIGH-LATITUDE MAGNETOPAUSE - REPLY SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Note ID MAGNETOSPHERE; CONVECTION C1 UNIV CALIF LOS ANGELES,INST GEOPHYS & PLANETARY PHYS,LOS ANGELES,CA 90024. RP GOSLING, JT (reprint author), LOS ALAMOS NATL LAB,MAIL STOP D438,LOS ALAMOS,NM 87545, USA. NR 6 TC 1 Z9 1 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0148-0227 J9 J GEOPHYS RES JI J. Geophys. Res-Space Phys. PD APR 1 PY 1993 VL 98 IS A4 BP 5945 EP 5945 DI 10.1029/92JA02017 PG 1 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA KW003 UT WOS:A1993KW00300031 ER PT J AU BOROVSKY, JE AF BOROVSKY, JE TI AURORAL ARC THICKNESSES AS PREDICTED BY VARIOUS THEORIES SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID FIELD-ALIGNED CURRENTS; PLASMA SHEET BOUNDARY; PARALLEL ELECTRIC-FIELDS; ELECTROSTATIC ION-CYCLOTRON; KINETIC ALFVEN WAVES; WEAK DOUBLE-LAYERS; TERRESTRIAL KILOMETRIC RADIATION; DIFFERENT TEMPERATURE PLASMAS; CURRENT-VOLTAGE RELATIONSHIP; ACOUSTIC DOUBLE-LAYERS AB Twenty-two theoretical mechanisms for auroral arcs are examined (12 electron-acceleration mechanisms and 10 generator mechanisms) and a characteristic auroral-arc thickness is worked out for each mechanism except one. The arc thicknesses are then mapped down to the ionosphere along the terrestrial magnetic-field lines: near the Earth a dipole magnetic-field model is used and farther from the Earth the mapping includes the effects of magnetic-field-line draping. The predicted thicknesses axe compared with published ground-based measurements of the optical thicknesses of auroral arcs in the ionosphere, which typically find arcs to be 100 m wide. The 21 theoretical models all predict auroral-arc thicknesses that are at least an order of magnitude wider than the optically observed arcs. As an alternative explanation of the optical observations of narrow auroral arcs, the acceleration of ionospheric electrons to produce airglow in electrical-discharge mechanisms is explored: these electrical-discharge mechanisms are found to be improbable. Also explored is the possibility that the observed narrow auroral arcs are caused by interference effects when Alfven waves reflect off the ionosphere: this is found to be an unlikely explanation. Suggestions are made for future ground-based auroral-arc measurements. RP BOROVSKY, JE (reprint author), LOS ALAMOS NATL LAB,SPACE & ATMOSPHER SCI GRP,MAIL STOP D466,LOS ALAMOS,NM 87545, USA. NR 377 TC 274 Z9 279 U1 4 U2 33 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0148-0227 J9 J GEOPHYS RES JI J. Geophys. Res-Space Phys. PD APR 1 PY 1993 VL 98 IS A4 BP 6101 EP 6138 DI 10.1029/92JA02242 PG 38 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA KW003 UT WOS:A1993KW00300046 ER PT J AU GRANDINETTI, PJ LEE, YK BALTISBERGER, JH SUN, BQ PINES, A AF GRANDINETTI, PJ LEE, YK BALTISBERGER, JH SUN, BQ PINES, A TI SIDE-BAND PATTERNS IN DYNAMIC-ANGLE-SPINNING NMR SO JOURNAL OF MAGNETIC RESONANCE SERIES A LA English DT Article ID NUCLEAR MAGNETIC-RESONANCE; ROTATING SOLIDS; MAGIC ANGLE; SPECTROSCOPY; SPECTRA; SAMPLES C1 UNIV CALIF BERKELEY,DEPT CHEM,BERKELEY,CA 94720. RP GRANDINETTI, PJ (reprint author), LAWRENCE BERKELEY LAB,DIV MAT SCI,1 CYCLOTRON RD,BERKELEY,CA 94720, USA. RI Grandinetti, Philip/F-1084-2010 OI Grandinetti, Philip/0000-0003-0102-316X NR 26 TC 20 Z9 20 U1 2 U2 4 PU ACADEMIC PRESS INC JNL-COMP SUBSCRIPTIONS PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 SN 1064-1858 J9 J MAGN RESON SER A JI J. Magn. Reson. Ser. A PD APR PY 1993 VL 102 IS 2 BP 195 EP 204 DI 10.1006/jmra.1993.1091 PG 10 WC Physics, Atomic, Molecular & Chemical SC Physics GA KZ480 UT WOS:A1993KZ48000011 ER PT J AU WOHLHUTER, FK BASARAN, OA AF WOHLHUTER, FK BASARAN, OA TI EFFECTS OF PHYSICAL-PROPERTIES AND GEOMETRY ON SHAPES AND STABILITY OF POLARIZABLE DROPS IN EXTERNAL FIELDS SO JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS LA English DT Article; Proceedings Paper CT 6TH INTERNATIONAL CONF ON MAGNETIC FLUIDS ( ICMF 6 ) CY JUL 20-24, 1992 CL PARIS, FRANCE SP FRENCH MINIST RES & TECHNOL, FRENCH GEN DIRECT ARMAMENT, UNIV PIERRE & MARIE CURIE, UNIV PARIS 7, UNESCO, LAB GUERBET, JAPAN SOC MAGNET FLUID RES, EXXON, FERROFLUIDICS, BIOL & IND ID MAGNETIC-FIELDS; ELECTRIC-FIELD; DROPLETS AB Equilibrium shapes and stability of linearly and nonlinearly polarizable drops floating freely between the two faces of a parallel-plate capacitor and subjected to an electric or magnetic field are found by solving the Young-Laplace equation for surface shape and the Maxwell equations for field distribution. Accounting for nonlinear polarization at last brings theory and experiment into accord. Finite plate separation-as in any real experiment-is also found to play a big role. C1 OAK RIDGE NATL LAB,DIV CHEM TECHNOL,OAK RIDGE,TN 37831. UNIV TENNESSEE,DEPT CHEM ENGN,KNOXVILLE,TN 37996. NR 11 TC 10 Z9 10 U1 1 U2 4 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 APR PY 1993 VL 122 IS 1-3 BP 259 EP 263 PG 5 WC Materials Science, Multidisciplinary; Physics, Condensed Matter SC Materials Science; Physics GA LD485 UT WOS:A1993LD48500062 ER PT J AU KUNG, PJ MALEY, MP WAHLBECK, PG PETERSON, DE AF KUNG, PJ MALEY, MP WAHLBECK, PG PETERSON, DE TI CHARACTERISTICS OF TLBA2CA2CU3O9+DELTA POWDER AS-SYNTHESIZED AND AFTER GRINDING SO JOURNAL OF MATERIALS RESEARCH LA English DT Article ID CU-O SYSTEM; SUPERCONDUCTORS; TRANSITION AB Crystal structure and superconductivity of the Tl-Ba-Ca-Cu-O powder prepared by a solid-state reaction were studied. The results of x-ray diffraction, scanning electron microscopy, and transmission electron microscopy analyses indicate that the powder of a major single 1223 phase was synthesized with a cauliflower-like morphology; by grinding, the powder was partially transformed to an amorphous phase. The measurement of magnetic hysteresis was also performed in the temperature range of 7-75 K up to 5 T from which the weak field-dependent behavior of critical current density was observed. The as-synthesized powder, with T(c) = 110 K measured from magnetometer and susceptometer, is considered to consist of weak-linked regions. The results obtained from comparing the as-synthesized and the ground powder imply that in the Tl-1223 system, the Ag-sheathed tapes fabricated by the powder-in-tube process may be benefited by forming other intermediate phases with plate-like morphologies to give better densification or grain alignment. C1 WICHITA STATE UNIV, DEPT CHEM, WICHITA, KS 67260 USA. RP LOS ALAMOS NATL LAB, CTR SUPERCONDUCT TECHNOL, MS K763, LOS ALAMOS, NM 87545 USA. NR 19 TC 5 Z9 5 U1 0 U2 3 PU CAMBRIDGE UNIV PRESS PI NEW YORK PA 32 AVENUE OF THE AMERICAS, NEW YORK, NY 10013-2473 USA SN 0884-2914 EI 2044-5326 J9 J MATER RES JI J. Mater. Res. PD APR PY 1993 VL 8 IS 4 BP 713 EP 719 DI 10.1557/JMR.1993.0713 PG 7 WC Materials Science, Multidisciplinary SC Materials Science GA KV487 UT WOS:A1993KV48700007 ER PT J AU MOROSIN, B NORTON, MG CARTER, CB VENTURINI, EL GINLEY, DS AF MOROSIN, B NORTON, MG CARTER, CB VENTURINI, EL GINLEY, DS TI STRUCTURAL STUDIES ON TL-CA-BA-CU-O SUPERCONDUCTING THIN-FILMS SO JOURNAL OF MATERIALS RESEARCH LA English DT Article ID CRYSTALS AB The microstructure of mixed phase, c-axis oriented Tl-Ca-Ba-Cu-O thin films, exhibiting excellent superconducting properties, has been examined by transmission electron microscopy and x-ray diffraction. Although the stoichiometry of the as-deposited films corresponds to the Tl2Ca2Ba2Cu3O10 phase (Tl-2223, c almost-equal-to 3.6 nm), x-ray diffraction showed these films contain up to 50% of the Tl2CaBa2Cu2O8 phase (Tl-2122, c almost-equal-to 2.9 nm). The x-ray diffraction peaks of the 3.6 nm phase are noticeably broader than those of the 2.9 nm phase, suggesting a smaller coherent size along the c-axis for the 3.6 nm phase. Lattice-fringe images of the 2.9 nm phase typically show only an occasional or no defect layer; however, such layer defects are more abundant in the 3.6 nm phase and, though random, occur with sufficiently wide separation and regularity to be consistent with an average coherency of approximately 40 nm. The coherent sizes along the c-axis, as determined by x-ray line profile analysis, were 140 nm and 40 nm, respectively, for the 2.9 nm and 3.6 nm phases, in good agreement with those determined by electron microscopy. The estimated width of the layer defects observed in the lattice-fringe images is suggestive, for the most part, of the four Cu-layered phases (TI-1324 or Tl-2324) and to a lesser degree the two Cu-layered phases (Tl-1122 or Tl-2122). C1 WASHINGTON STATE UNIV,PULLMAN,WA 99164. UNIV MINNESOTA,MINNEAPOLIS,MN 55455. RP MOROSIN, B (reprint author), SANDIA NATL LABS,ALBUQUERQUE,NM 87185, USA. RI Carter, C. Barry/E-6478-2010 OI Carter, C. Barry/0000-0003-4251-9102 NR 14 TC 7 Z9 7 U1 0 U2 0 PU MATERIALS RESEARCH SOCIETY PI PITTSBURGH PA 9800 MC KNIGHT ROAD SUITE 327, PITTSBURGH, PA 15237 SN 0884-2914 J9 J MATER RES JI J. Mater. Res. PD APR PY 1993 VL 8 IS 4 BP 720 EP 726 DI 10.1557/JMR.1993.0720 PG 7 WC Materials Science, Multidisciplinary SC Materials Science GA KV487 UT WOS:A1993KV48700008 ER PT J AU HOLLOWAY, A MCCALLUM, RW ARRASMITH, SR AF HOLLOWAY, A MCCALLUM, RW ARRASMITH, SR TI TEXTURE DEVELOPMENT DUE TO PREFERENTIAL GRAIN-GROWTH OF HO-BA-CU-O IN 1.6-T MAGNETIC-FIELD SO JOURNAL OF MATERIALS RESEARCH LA English DT Article ID HIGH-TC SUPERCONDUCTORS; CRITICAL CURRENTS; HIGH-TEMPERATURE; YBA2CU3O7-DELTA; ANISOTROPY; BICRYSTALS AB It has been experimentally observed that the application of even a relatively weak magnetic field of 1.6 T during sintering of HoBa2Cu3O7-delta (hereafter HoBCO) results in a significant degree of grain alignment. The orientation of grains is found to be controlled by the direction and magnitude of a magnetic field. The degree of alignment was monitored by x-ray diffraction measurements on the flat surface of the samples and by metallography. It has been observed that the degree of alignment grows as the magnitude of the field increases between 0 and 1.6 T for a fixed temperature and processing time. The degree of alignment also increases when the processing temperature changes from 930-degrees-C to 965-degrees-C for a fixed field and time. It has also been observed that for both a fixed field and processing temperature, the alignment grows when the processing time increases between 16 and 72 h. Metallography measurements on the flat and cross-sectional parts of the samples showed that the texture propagates into the bulk of the samples. In the presence of a sufficient amount of the liquid phase, the enhancement of the grain growth in the direction favorable to the magnetic field produces rather large single crystals (0.3 to 0.5 mm linear size) within the sample. C1 IOWA STATE UNIV SCI & TECHNOL,US DOE,AMES LAB,AMES,IA 50011. RP HOLLOWAY, A (reprint author), UNIV NEBRASKA,DEPT PHYS,OMAHA,NE 68182, USA. NR 27 TC 27 Z9 29 U1 2 U2 8 PU MATERIALS RESEARCH SOCIETY PI PITTSBURGH PA 9800 MC KNIGHT ROAD SUITE 327, PITTSBURGH, PA 15237 SN 0884-2914 J9 J MATER RES JI J. Mater. Res. PD APR PY 1993 VL 8 IS 4 BP 727 EP 733 DI 10.1557/JMR.1993.0727 PG 7 WC Materials Science, Multidisciplinary SC Materials Science GA KV487 UT WOS:A1993KV48700009 ER PT J AU NIEH, TG WADSWORTH, J CHOU, TC OWEN, D CHOKSHI, AH AF NIEH, TG WADSWORTH, J CHOU, TC OWEN, D CHOKSHI, AH TI CREEP OF A NIOBIUM BERYLLIDE, NB2BE17 SO JOURNAL OF MATERIALS RESEARCH LA English DT Article ID SUPERPLASTICITY; INTERMETALLICS; DEFORMATION; BEHAVIOR; METAL; FLOW; COAL AB A niobium beryllide, Nb2Be17, has been prepared by powder-metallurgy techniques and the mechanical properties characterized both at room and elevated temperatures. Microhardness and fracture toughness were measured at room temperature. Hardness and hot-hardness test results indicated that, although the material was brittle at low temperatures, it became plastic at elevated temperatures (>1000-degrees-C). Creep properties of Nb2Be17 were studied at temperatures from 1250 to 1350-degrees-C and applied stresses from 10 to 90 MPa. The stress exponent, determined from stress-change tests, was about 3, and the activation energy, determined from temperature-change tests, was about 575 kJ/mol. The creep of Nb2Be17 at high temperature is apparently controlled by dislocation glide; this proposal was supported by transient creep experiments. Comparisons have been made between the creep properties of Nb2Be17 and other intermetallics. C1 LOCKHEED,PALO ALTO,CA 94304. UNIV CALIF SAN DIEGO,DEPT APPL MECH & ENGN SCI,LA JOLLA,CA 92093. RP NIEH, TG (reprint author), LAWRENCE LIVERMORE NATL LAB,L-350,POB 808,LIVERMORE,CA 94550, USA. RI Nieh, Tai-Gang/G-5912-2011 OI Nieh, Tai-Gang/0000-0002-2814-3746 NR 28 TC 3 Z9 3 U1 1 U2 1 PU MATERIALS RESEARCH SOCIETY PI PITTSBURGH PA 9800 MC KNIGHT ROAD SUITE 327, PITTSBURGH, PA 15237 SN 0884-2914 J9 J MATER RES JI J. Mater. Res. PD APR PY 1993 VL 8 IS 4 BP 757 EP 763 DI 10.1557/JMR.1993.0757 PG 7 WC Materials Science, Multidisciplinary SC Materials Science GA KV487 UT WOS:A1993KV48700013 ER PT J AU HOSOYA, M REYNOLDS, G DRESSELHAUS, MS PEKALA, RW AF HOSOYA, M REYNOLDS, G DRESSELHAUS, MS PEKALA, RW TI PHOTOCONDUCTIVITY OF CARBON AEROGELS SO JOURNAL OF MATERIALS RESEARCH LA English DT Article ID PERSISTENT PHOTOCONDUCTIVITY; A-SI; SEMICONDUCTORS; FIBERS; MODEL AB Photoconductivity was measured on a series of carbon aerogels to investigate their electronic properties. Carbon aerogels are a special class of low-density microcellular foams, consisting of interconnected carbon particles (approximately 120 angstrom diameter) and narrow graphitic ribbons (approximately 25 angstrom width) intertwined within each particle. Both the dark- and photoconductivities show drastic changes in the temperature range 5-300 K, which are similar to those in a-Si and chalcogenide photoconductors. At high temperatures, the photoconductivity is dominated by the carrier recombination within each particle. The photoconductivity at low temperatures is dominated by the same carrier transport mechanism as that for the dark conductivity, which is based on hopping and tunneling transport. The activation energy values for transport and recombination identify the electronic structure of the particles among samples of different bulk density. The long decay time of the photoconductivity suggests a relaxation mechanism associated with the dangling bonds. C1 MIT,DEPT PHYS,CAMBRIDGE,MA 02139. MIT,DEPT ELECT ENGN & COMP SCI,CAMBRIDGE,MA 02139. LAWRENCE LIVERMORE NATL LAB,DEPT CHEM & MAT SCI,LIVERMORE,CA 94550. NR 24 TC 14 Z9 15 U1 2 U2 3 PU MATERIALS RESEARCH SOCIETY PI PITTSBURGH PA 9800 MC KNIGHT ROAD SUITE 327, PITTSBURGH, PA 15237 SN 0884-2914 J9 J MATER RES JI J. Mater. Res. PD APR PY 1993 VL 8 IS 4 BP 811 EP 819 DI 10.1557/JMR.1993.0811 PG 9 WC Materials Science, Multidisciplinary SC Materials Science GA KV487 UT WOS:A1993KV48700019 ER PT J AU RAO, GR WANG, ZL LEE, EH AF RAO, GR WANG, ZL LEE, EH TI MICROSTRUCTURAL EFFECTS ON SURFACE MECHANICAL-PROPERTIES OF ION-IMPLANTED POLYMERS SO JOURNAL OF MATERIALS RESEARCH LA English DT Article ID IRRADIATION AB Tefzel, a copolymer of tetrafluoroethylene and ethylene, was implanted simultaneously with 400 keV boron, 700 keV nitrogen, and 600 keV carbon to a dose of 3 X 10(15) ions/cm2 for each ion. The implanted layer was examined using transmission electron microscope and compared with the pristine Tefzel for microstructural changes. The microhardness of the implanted and pristine Tefzel was determined using a nanoindentation technique. TEM bright-field images of the implanted layer show a patch-type contrast with distinguishable bright and dark regions. Electron energy loss spectroscopy (EELS) was used to show that the bright regions had a higher carbon concentration, as compared with the dark regions. The carbon-rich regions had an average size of approximately 40 nm. The pristine material showed a fairly featureless contrast with occasional local patchy regions. These were determined to be due to local thickness variations. The triple implantation improved the hardness of pristine Tefzel by over 66 times. The structure of the carbon-rich regions appears to be clusters of sp2 bonded C atoms with sp3 sites present and hydrogen preferentially bonded in the sp3 C configuration. It was speculated that the carbon-rich regions could be harder than the surrounding regions, but this could not be resolved due to the small size of the regions. RP RAO, GR (reprint author), OAK RIDGE NATL LAB,DIV MET & CERAM,POB 2008,OAK RIDGE,TN 37831, USA. RI Wang, Zhong Lin/E-2176-2011 OI Wang, Zhong Lin/0000-0002-5530-0380 NR 21 TC 19 Z9 25 U1 0 U2 0 PU MATERIALS RESEARCH SOCIETY PI PITTSBURGH PA 9800 MC KNIGHT ROAD SUITE 327, PITTSBURGH, PA 15237 SN 0884-2914 J9 J MATER RES JI J. Mater. Res. PD APR PY 1993 VL 8 IS 4 BP 927 EP 933 DI 10.1557/JMR.1993.0927 PG 7 WC Materials Science, Multidisciplinary SC Materials Science GA KV487 UT WOS:A1993KV48700034 ER PT J AU ZARDECKI, A AF ZARDECKI, A TI A FORMULATION OF SUPERGRAVITY BASED ON CARTAN CONNECTION SO JOURNAL OF MATHEMATICAL PHYSICS LA English DT Article ID FREE GRAVITY LAGRANGIANS; GENERALIZED SUPERMANIFOLDS; PROPAGATING TORSION; GAUGE-THEORY; SUPERSPACES; FORMALISM; FIELDS AB The supergravity is formulated as a gauge theory with the Yang-Mills Lagrangian quadratic in curvature. To arrive at such a description, the super fiber bundle based on a superspace with the OSP(n/4) symmetry group is introduced. The connection in this bundle becomes the Cartan connection when OSP(n/4) is broken to SL(2,C) x SO(n). In the reduced bundle, this leads automatically to curvature and torsion. Explicit calculations of the Lagrangian are carried out in terms of the Cartan-Killing metrics and the curvature form for n = 1 and n = 8. The final theory describes the coupling of geometry to fermion fields. These fields emerge as solder forms of the Cartan connection. RP ZARDECKI, A (reprint author), LOS ALAMOS NATL LAB,MS E541,LOS ALAMOS,NM 87545, USA. NR 42 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 0022-2488 J9 J MATH PHYS JI J. Math. Phys. PD APR PY 1993 VL 34 IS 4 BP 1487 EP 1496 DI 10.1063/1.530168 PG 10 WC Physics, Mathematical SC Physics GA KW985 UT WOS:A1993KW98500016 ER PT J AU MANNUZZU, LM MORONNE, MM MACEY, RI AF MANNUZZU, LM MORONNE, MM MACEY, RI TI ESTIMATE OF THE NUMBER OF UREA TRANSPORT SITES IN ERYTHROCYTE-GHOSTS USING A HYDROPHOBIC MERCURIAL SO JOURNAL OF MEMBRANE BIOLOGY LA English DT Article DE UREA TRANSPORT; ERYTHROCYTES; MERCURIALS; SPIN LABELS; ELECTRON SPIN RESONANCE; HYDROPHOBICITY ID RED-CELL MEMBRANE; WATER TRANSPORT; CHLORIDE TRANSPORT; ETHYLENE-GLYCOL; BLOOD-CELLS; PERMEABILITY; INHIBITION; BINDING; REDUCTION; PHENOTYPE AB In this paper a variety of mercurials, including a pCMB-nitroxide analogue, were used to study urea transport in human red cell ghosts. It was determined that the rate of inhibition for pCMBS, pCMB, pCMB-nitroxide, and chlormerodrin extended over four orders of magnitude consistent with their measured oil/water partition coefficients. From these results, we concluded that a significant hydrophobic barrier limits access to the urea inhibition site, suggesting that the urea site is buried in the bilayer or in a hydrophobic region of the transporter. In contrast, the rate of water inhibition by the mercurials ranged by only a factor of four and did not correlate with their hydrophobicities. Thus, the water inhibition site may be more directly accessible via the aqueous phase. Under conditions that leave water transport unaffected, we determined that less-than-or-equal-to 32.000 labeled sites per cell corresponded to complete inhibition of urea transport. This rules out major transmembrane proteins such as band 3, the glucose carrier, and CHIP28 as candidates for the urea transporter. In contrast, this result is consistent with the Kidd (Jk) antigen being the urea transporter with an estimated 14,000 copies per cell. From the experimental number of urea sites, a turnover number between 2-6 x 10(6) sec-1 at 22-degrees-C is calculated suggesting a channel mechanism. C1 LAWRENCE BERKELEY LAB,BERKELEY,CA 94720. RP MANNUZZU, LM (reprint author), UNIV CALIF BERKELEY,DEPT MOLEC & CELL BIOL,BERKELEY,CA 94720, USA. FU NHLBI NIH HHS [HL-20985, HL-37593] NR 55 TC 26 Z9 27 U1 1 U2 4 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 SN 0022-2631 J9 J MEMBRANE BIOL JI J. Membr. Biol. PD APR PY 1993 VL 133 IS 1 BP 85 EP 97 PG 13 WC Biochemistry & Molecular Biology; Cell Biology; Physiology SC Biochemistry & Molecular Biology; Cell Biology; Physiology GA KY115 UT WOS:A1993KY11500008 PM 8391582 ER PT J AU NIVENS, DE CHAMBERS, JQ ANDERSON, TR TUNLID, A SMIT, J WHITE, DC AF NIVENS, DE CHAMBERS, JQ ANDERSON, TR TUNLID, A SMIT, J WHITE, DC TI MONITORING MICROBIAL ADHESION AND BIOFILM FORMATION BY ATTENUATED TOTAL REFLECTION FOURIER-TRANSFORM INFRARED-SPECTROSCOPY SO JOURNAL OF MICROBIOLOGICAL METHODS LA English DT Article DE CAULOBACTER; BIOFILM; ATTENUATED TOTAL REFLECTION; INFRARED ID CAULOBACTER-CRESCENTUS; BACTERIA; IDENTIFICATION; MICROSCOPY; CORROSION AB A major problem in accurately defining bacterial adhesion mechanisms and processes occurring in biofilms on surfaces is the lack of techniques that nondestructively provide on-line information about the microorganisms, their extracellular polymers, and metabolites. The attenuated total reflectance (ATR) technique of Fourier transform infrared spectroscopy (FT-IR) is ideally suited to monitor molecular interactions at the solution/internal reflection element (IRE) interface, and we report its application to biofilm research. Two methodologies were utilized to obtain the ATR/FT-IR spectra of living Caulobacter crescentus cells attached to germanium crystals. Initially, spectra of attached bacteria in high purity water produced molecular details of the attachment process without spectral interferences from components of the medium. A growth medium, utilized in the second method, allowed direct examination of the infrared absorption bands associated with the actively growing microorganisms on the surface of the IRE in the spectral region of 2000 to 1200 cm-1. Using the amide 11 band as a marker for biofilm biomass, the detection limit was determined to be approximately 5 x 10(5) cells.cm-2. These results proved that the ATR-FT/IR methodologies can be utilized to provide chemical information from bacteria and bacterial products located within approximately 1 mum of the surface without spectral interferences due to components of the medium. C1 UNIV TENNESSEE,DEPT CHEM,KNOXVILLE,TN 37932. OAK RIDGE NATL LAB,OAK RIDGE,TN 37831. UNIV LUND,ECOL LAB,S-22101 LUND,SWEDEN. UNIV BRITISH COLUMBIA,DEPT MICROBIOL,VANCOUVER V6T 1W5,BC,CANADA. RP NIVENS, DE (reprint author), UNIV TENNESSEE,CTR ENVIRONM BIOTECHNOL,10515 RES DR,BLDG 1,SUITE 300,KNOXVILLE,TN 37932, USA. NR 36 TC 61 Z9 62 U1 3 U2 16 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0167-7012 J9 J MICROBIOL METH JI J. Microbiol. Methods PD APR PY 1993 VL 17 IS 3 BP 199 EP 213 DI 10.1016/0167-7012(93)90047-L PG 15 WC Biochemical Research Methods; Microbiology SC Biochemistry & Molecular Biology; Microbiology GA KZ074 UT WOS:A1993KZ07400004 ER PT J AU BURLEY, JD MILLER, CE JOHNSTON, HS AF BURLEY, JD MILLER, CE JOHNSTON, HS TI SPECTROSCOPY AND PHOTOABSORPTION CROSS-SECTIONS OF FNO SO JOURNAL OF MOLECULAR SPECTROSCOPY LA English DT Article ID MOLECULAR-ORBITAL THEORY; NITROSYL FLUORIDE; ELECTRONIC-STRUCTURE; ORGANIC COMPOUNDS; STATES; PHOTODISSOCIATION; MICROWAVE; CONSTANTS; SPECTRUM; ENERGIES C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY NATL LAB,DIV CHEM SCI,BERKELEY,CA 94720. RP BURLEY, JD (reprint author), UNIV CALIF BERKELEY,DEPT CHEM,BERKELEY,CA 94720, USA. NR 61 TC 13 Z9 13 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 0022-2852 J9 J MOL SPECTROSC JI J. Mol. Spectrosc. PD APR PY 1993 VL 158 IS 2 BP 377 EP 391 DI 10.1006/jmsp.1993.1082 PG 15 WC Physics, Atomic, Molecular & Chemical; Spectroscopy SC Physics; Spectroscopy GA KU191 UT WOS:A1993KU19100014 ER PT J AU PAWEL, SJ AF PAWEL, SJ TI TYPE-304L STAINLESS-STEEL CORROSION IN MOLTEN LITHIUM HYDRIDE AS A FUNCTION OF TEMPERATURE SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article AB A series of compatibility experiments has been performed with Type 304L stainless steel exposed to molten lithium hydride (LiH) in the temperature range 715-850-degrees-C. The primary corrosion mechanism of Type 304L stainless steel in this environment has been determined to be selective leaching of nickel leading to the formation of a ferritic surface layer, The ferrite layer seems to be adherent under the conditions evaluated but other observations suggest the ferrite is porous on a microscopic scale and relatively weak in terms of mechanical properties. At all temperatures examined, the ferrite layer growth rate decreases with extended exposure time due to the increasing thickness of the ferrite layer acting as a barrier to further nickel leaching. Cumulative exposure times were insufficient to establish true steady-state ferrite growth rates but, for exposure times near 400 h, the average ferrite layer growth rate ranges from about 0.1 mm/yr (715-degrees-C) to about 0.4 mm/yr (850-degrees-C). RP PAWEL, SJ (reprint author), MARTIN MARIETTA ENERGY SYST INC,OAK RIDGE Y12 PLANT,DIV DEV,POB 2009,OAK RIDGE,TN 37831, USA. NR 10 TC 4 Z9 4 U1 1 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3115 J9 J NUCL MATER JI J. Nucl. Mater. PD APR PY 1993 VL 200 IS 2 BP 184 EP 199 DI 10.1016/0022-3115(93)90329-W PG 16 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA KY370 UT WOS:A1993KY37000005 ER PT J AU WRIGHT, RN VANSICLEN, CD USMAR, SG AF WRIGHT, RN VANSICLEN, CD USMAR, SG TI ENHANCED HELIUM BUBBLE DIFFUSION IN ALUMINUM CONTAINING A LIQUID-METAL IMPURITY SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article ID IRRADIATED ALUMINUM; GROWTH AB Remarkably rapid Brownian motion of helium bubbles in aluminum alloyed with very low concentrations of lead or of indium has been observed in situ by hot-stage transmission electron microscopy. Bubble diffusion is enhanced as the impurity, which appears at room temperature as solid precipitates attached to the helium bubbles, coats the bubble surfaces at annealing temperatures above the melting point of the impurity. The bubble diffusion coefficients, calculated from video images of the bubble motion, and the cor-responding surface diffusion coefficients (assuming bubble migration by aluminum self-diffusion at the bubble surface) are orders-of-magnitude larger than diffusion coefficients determined from helium bubble growth experiments in pure aluminum. C1 UNIV BRISTOL,HH WILLS PHYS LAB,BRISTOL BS8 1TL,AVON,ENGLAND. ARGONNE NATL LAB,HVEM,TANDEM FACIL,ARGONNE,IL 60439. RP WRIGHT, RN (reprint author), IDAHO NATL ENGN LAB,IDAHO FALLS,ID 83415, USA. NR 19 TC 2 Z9 2 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3115 J9 J NUCL MATER JI J. Nucl. Mater. PD APR PY 1993 VL 200 IS 2 BP 200 EP 206 DI 10.1016/0022-3115(93)90330-2 PG 7 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA KY370 UT WOS:A1993KY37000006 ER PT J AU SUZUKI, S CRAWFORD, JF BRADLEY, JT GAHL, JM NYGREN, R AF SUZUKI, S CRAWFORD, JF BRADLEY, JT GAHL, JM NYGREN, R TI EXPERIMENTAL-STUDY OF PULSE PLASMA HEAT-FLUX ABSORPTION AND ABLATION DURING THE SIMULATION OF A TOKAMAK PLASMA DISRUPTION SO JOURNAL OF NUCLEAR MATERIALS LA English DT Letter C1 UNIV NEW MEXICO,ALBUQUERQUE,NM 87131. SANDIA NATL LABS,ALBUQUERQUE,NM 87185. RP SUZUKI, S (reprint author), JAPAN ATOM ENERGY RES INST,NAKA FUS RES ESTAB,NAKA,IBARAKI 31101,JAPAN. NR 10 TC 11 Z9 11 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3115 J9 J NUCL MATER JI J. Nucl. Mater. PD APR PY 1993 VL 200 IS 2 BP 265 EP 269 DI 10.1016/0022-3115(93)90337-X PG 5 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA KY370 UT WOS:A1993KY37000013 ER PT J AU VOLKOW, ND FOWLER, JS WANG, GJ DEWEY, SL SCHLYER, D MACGREGOR, R LOGAN, J ALEXOFF, D SHEA, C HITZEMANN, R ANGRIST, B WOLF, AP AF VOLKOW, ND FOWLER, JS WANG, GJ DEWEY, SL SCHLYER, D MACGREGOR, R LOGAN, J ALEXOFF, D SHEA, C HITZEMANN, R ANGRIST, B WOLF, AP TI REPRODUCIBILITY OF REPEATED MEASURES OF CARBON-11-RACLOPRIDE BINDING IN THE HUMAN BRAIN SO JOURNAL OF NUCLEAR MEDICINE LA English DT Article ID POSITRON EMISSION TOMOGRAPHY; D2 DOPAMINE-RECEPTORS; ENDOGENOUS DOPAMINE; H-3 RACLOPRIDE; BASAL GANGLIA; MOUSE-BRAIN; PET; INVIVO AB Carbon-11-raclopride has been successfully utilized with PET to assess changes in endogenous dopamine concentration after pharmacological intervention in the living baboon brain. For similar studies to be done in humans, measurements of C-11-raclopride with no intervention need to be reproducible. In order to test the reproducibility (test-retest) of C-11-raclopride binding in the human brain, we performed repeated studies on two different days. Studies were done in five normal controls with no pharmacological intervention. Time-activity (%dose/cc) curves for C-11-raclopride in the basal ganglia (BG) and cerebellum (CBL) were highly reproducible with an average difference in peak uptake for repeated studies in the same individual of 4%. The BG to CBL ratio for the average activity concentration between 30 and 60 min showed differences that ranged from -7% to 8% between the repeated studies. Graphical analysis to obtain the distribution volume revealed intrasubject values that ranged from -9% to 7% for the ratio of the distribution volume in BG to that in CBL. These studies demonstrate that in order to use C-11-raclopride to measure an individual's change in relative dopamine concentration secondary to pharmacological or behavioral intervention, a change in striatal C-11-raclopride binding in excess of 10% is required. C1 SUNY STONY BROOK,DEPT CHEM,STONY BROOK,NY 11794. BROOKHAVEN NATL LAB,DEPT PSYCHIAT,UPTON,NY 11973. NYU,DEPT PSYCHIAT,NEW YORK,NY 10003. RP VOLKOW, ND (reprint author), BROOKHAVEN NATL LAB,DEPT MED,BLDG 490,UPTON,NY 11973, USA. FU NIDA NIH HHS [5RO1-DA06891]; NINDS NIH HHS [NS15638] NR 19 TC 172 Z9 173 U1 0 U2 0 PU SOC NUCLEAR MEDICINE INC PI RESTON PA 1850 SAMUEL MORSE DR, RESTON, VA 20190-5316 SN 0161-5505 J9 J NUCL MED JI J. Nucl. Med. PD APR PY 1993 VL 34 IS 4 BP 609 EP 613 PG 5 WC Radiology, Nuclear Medicine & Medical Imaging SC Radiology, Nuclear Medicine & Medical Imaging GA KV038 UT WOS:A1993KV03800012 PM 8455077 ER PT J AU DING, YS FOWLER, JS DEWEY, SL LOGAN, J SCHLYER, DJ GATLEY, SJ VOLKOW, ND KING, PT WOLF, AP AF DING, YS FOWLER, JS DEWEY, SL LOGAN, J SCHLYER, DJ GATLEY, SJ VOLKOW, ND KING, PT WOLF, AP TI COMPARISON OF HIGH SPECIFIC ACTIVITY (-) AND (+)-6-[F-18]FLUORONOREPINEPHRINE AND 6-[F-18]FLUORODOPAMINE IN BABOONS HEART UPTAKE, METABOLISM AND THE EFFECT OF DESIPRAMINE SO JOURNAL OF NUCLEAR MEDICINE LA English DT Article ID POSITRON EMISSION TOMOGRAPHY; NUCLEOPHILIC AROMATIC-SUBSTITUTION; CARDIAC SYMPATHETIC INNERVATION; NERVOUS-SYSTEM; NEURONAL UPTAKE; FATE; 6-FLUORODOPAMINE; STORAGE AB (-)-Norepinephrine is the principal neurotransmitter of the mammalian sympathetic nervous system and a major CNS neurotransmitter. The simple ring fluorinated derivatives of (-)- and (+)-norepinephrine [(-)- and (+)6-fluoronorepinephrine] and dopamine (6-fluorodopamine) have been labeled with F-18 in high specific activity (2-5 Ci/mumol) and evaluated as tracers for (-)-norepinephrine. Comparative PET studies of (-) and (+)-6-[F-18]fluoronorepinephrine [(-)6-[F-18]FNE and (+)-6-[F-18]FNE] and 6-[F-18]fluorodopamine (6-[F-18]FDA) in the same baboon showed strikingly different kinetics in the heart. Analysis of plasma showed more rapid metabolism of 6-[F-18]FDA with only 1%-2% of F-18 remaining as parent tracer at 10 min after injection of 6-[F-18]FDA, in contrast to 28% and 17% remaining after injection of (-) and (+)-6-[F-18]FNE. No changes in vital signs were observed at any time during the study. Pretreatment with desipramine (0.5 mg/kg), a tricyclic antidepressant drug which interacts with a binding site associated with norepinephrine reuptake, markedly decreased cardiac uptake of 6-[F-18]FDA and (-)-6-[F-18]FNE. However, a greater blocking effect was observed for (-)-6-[F-18]FNE. These studies show that (-) and (+)-6-[F-18]FNE are similar to (-)- and (+)-norepinephrine in their patterns of metabolism and clearance in the heart and that (-)-6-[F-18]FNE is a promising tracer for endogenous (-)-norepinephrine. RP DING, YS (reprint author), BROOKHAVEN NATL LAB, DEPT CHEM, BLDG 555 LEWIS RD, UPTON, NY 11973 USA. FU NINDS NIH HHS [NS-15380] NR 40 TC 35 Z9 35 U1 0 U2 0 PU SOC NUCLEAR MEDICINE INC PI RESTON PA 1850 SAMUEL MORSE DR, RESTON, VA 20190-5316 USA SN 0161-5505 EI 1535-5667 J9 J NUCL MED JI J. Nucl. Med. PD APR PY 1993 VL 34 IS 4 BP 619 EP 629 PG 11 WC Radiology, Nuclear Medicine & Medical Imaging SC Radiology, Nuclear Medicine & Medical Imaging GA KV038 UT WOS:A1993KV03800014 PM 8455079 ER PT J AU SLOOF, GW VISSER, FC VANEENIGE, MJ COMANS, EFI TEERLINK, T HERSCHEID, JDM VANDERVUSSE, GJ KNAPP, FFR AF SLOOF, GW VISSER, FC VANEENIGE, MJ COMANS, EFI TEERLINK, T HERSCHEID, JDM VANDERVUSSE, GJ KNAPP, FFR TI COMPARISON OF UPTAKE, OXIDATION AND LIPID DISTRIBUTION OF 17-IODOHEPTADECANOIC ACID, 15-(P-IODOPHENYL)PENTADECANOIC ACID AND 15-(P-IODOPHENYL)-3,3-DIMETHYLPENTADECANOIC ACID IN NORMAL CANINE MYOCARDIUM SO JOURNAL OF NUCLEAR MEDICINE LA English DT Article ID I-123 PHENYLPENTADECANOIC ACID; BRANCHED FATTY-ACIDS; HEPTADECANOIC ACID; EMISSION TOMOGRAPHY; HYPERTENSIVE RATS; METABOLIC-FATE; SCINTIGRAPHY; TRACER; HEART; DEIODINATION AB The kinetics of 17-[I-123]iodoheptadecanoic acid (IHDA), 15-(p-[I-125]iodophenyl)pentadecanoic acid (pIPPA) and 15-(p-[I-131]iodophenyl)-3,3-dimethylpentadecanoic acid (DMIPPA) were investigated in normal canine myocardium. After simultaneous intravenous injection, myocardial biopsy specimens and samples of arterial blood were taken over 80 min. IHDA showed the highest myocardial uptake (995 +/- 248 dpm/mg.mCi versus pIPPA: 785 +/- 197 dpm/mg.mCi, ns) and the largest size of oxidation (74% +/- 4% versus pIPPA: 65% +/-5%, p < 0.05). Myocardial activity of IHDA decreased with a half-time value of 11.2 min (pIPPA: 13.2 min). Phospholipids were the main lipid fraction into which IHDA was incorporated, whereas pIPPA was predominantly incorporated into triacylglycerols. DMIPPA myocardial activity remained constant during the assay period and instead of being oxidized, DMIPPA was mainly incorporated into triacylglycerols (55% +/- 12%). The myocardium-to-blood ratios of DMIPPA were greater than 10:1. The ratios at peak for IHDA and pIPPA were 4.1:1 and 3.9:1, respectively (both p < 0.0001 versus DMIPPA). In conclusion, differences have been found in the myocardial uptake, oxidation and lipid distribution of IHDA, pIPPA and DMIPPA. DMIPPA is a promising tracer for fatty acid uptake studies with single-photon emission computerized tomography because of its prolonged retention and high myocardium-to-blood ratios. C1 OAK RIDGE NATL LAB,NUCL MED GRP,OAK RIDGE,TN 37830. UNIV LIMBURG,DEPT PHYSIOL,6200 MD MAASTRICHT,NETHERLANDS. RP SLOOF, GW (reprint author), FREE UNIV AMSTERDAM HOSP,DEPT CARDIOL,METAB LAB,CTR RADIONUCLIDE,DE BOELELAAN 1117,1081 HV AMSTERDAM,NETHERLANDS. NR 47 TC 14 Z9 14 U1 0 U2 0 PU SOC NUCLEAR MEDICINE INC PI RESTON PA 1850 SAMUEL MORSE DR, RESTON, VA 20190-5316 SN 0161-5505 J9 J NUCL MED JI J. Nucl. Med. PD APR PY 1993 VL 34 IS 4 BP 649 EP 657 PG 9 WC Radiology, Nuclear Medicine & Medical Imaging SC Radiology, Nuclear Medicine & Medical Imaging GA KV038 UT WOS:A1993KV03800018 PM 8455083 ER PT J AU STABIN, MG AF STABIN, MG TI RADIATION-DOSE TO THE UPPER SPINE FROM THERAPEUTIC ADMINISTRATIONS OF IODINE-131-SODIUM IODIDE SO JOURNAL OF NUCLEAR MEDICINE LA English DT Article AB Thyroid cancer patients sometimes receive conventional external irradiation to the neck in addition to radioactive iodine therapy. In these situations, knowledge of the radiation dose already received by the spine in the neck area from the radioiodine administration can be an aid in treatment planning. This paper gives an estimate of the radiation dose to the upper spine from administration of 3700 MBq of I-131-sodium iodide. Monte Carlo codes used to estimate radiation dose from internal emitters usually give absorbed doses to the whole spine or marrow. One such code was modified to give a dose only to the upper spine region near the thyroid. Calculations assumed a thyroid uptake of 10% of administered activity and retention with a 35-hr effective half-time. Activity in the remainder of the body was assumed to clear with a 6-hr half-time to urine. Under these assumptions, the dose to this upper spine region was about 200 mGy. RP STABIN, MG (reprint author), OAK RIDGE INST SCI & EDUC,DIV MED SCI,CTR RADIAT INTERNAL DOSE INFORMAT,POB 117,OAK RIDGE,TN 37831, USA. FU FDA HHS [FDA 224-75-3016] NR 7 TC 3 Z9 3 U1 0 U2 2 PU SOC NUCLEAR MEDICINE INC PI RESTON PA 1850 SAMUEL MORSE DR, RESTON, VA 20190-5316 SN 0161-5505 J9 J NUCL MED JI J. Nucl. Med. PD APR PY 1993 VL 34 IS 4 BP 695 EP 696 PG 2 WC Radiology, Nuclear Medicine & Medical Imaging SC Radiology, Nuclear Medicine & Medical Imaging GA KV038 UT WOS:A1993KV03800025 PM 8455090 ER EF