FN Thomson Reuters Web of Science™ VR 1.0 PT J AU Alonso, MV Minniti, D AF Alonso, MV Minniti, D TI Infrared photometry of 487 sources in the inner regions of NGC 5128 (Centaurus A) SO ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES LA English DT Article DE galaxies, individual (NGC 5128); galaxies, photometry; galaxies, star clusters; infrared, galaxies; surveys ID GLOBULAR-CLUSTER SYSTEM; SPACE-TELESCOPE OBSERVATIONS; STAR-CLUSTERS; LUMINOSITY FUNCTION; MAGELLANIC CLOUDS; METAL ABUNDANCES; PLANETARY CAMERA; NGC-5128; GALAXIES; DYNAMICS AB We study the sources present in the inner 3 kpc region of NGC 5128 (Cen A), most of which are star clusters of different ages. Photometry of archival Hubble Space Telescope WFPC images (F675W filter) is complemented with IR photometry (JHK' filters) obtained with the IRAC2B infrared array camera at the ESO/MPI2.2 m telescope. From IR color maps we divide the field into two regions: a clear region outside the dust lane, and an obscured region well inside the dust lane of NGC 5128. In the unreddened region there is a great variety of sources such as globular clusters, star associations, and H II regions. These sources are not individual stars, which would be too faint to be resolved from ground-based telescopes. The vast majority of IR sources in the reddened region, where the dust lane dominates, are not seen at all in the deep HST images. The presence of large amounts of differential extinction makes it difficult to evaluate them. In total, there are 372 objects detected in the inner region of NGC 5128. From them, 125 objects are detected both in IR and HST frames. There are 247 IR sources without optical counterparts (47 in the clear region and 200 in the dust lane). Accounting for the small volume sampled, there must be a total of similar to 500 sources with K < 18 in the dust lane region. The distribution of these sources is rather uniform and not particularly centrally concentrated. This fact suggests that the majority of them are located in a disk, as would be expected if they are young associations or clusters. The degree of background and foreground contamination is evaluated using observations of a nearby field. We found 115 IR sources in this field. The nucleus itself is invisible in deep optical images, but it is clearly identified in the IR. In the region just south of the nucleus the extinction must be larger than A(K) = 3. In the clear region, where the effect of the dust lane is negligible, we have identified some objects as intermediate-age clusters containing carbon stars. From color-magnitude diagrams we do not find evidence of very young clusters in this region. Such clusters might be fainter than our detection limit in JHK'. We measure metallicities for 42 globular clusters, confirming the presence of a metallicity gradient with Delta[Fe/H]/Delta R = -0.06 dex kpc(-1). C1 EUROPEAN SO OBSERV,D-85748 GARCHING,GERMANY. LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550. RP Alonso, MV (reprint author), ASTRON OBSERV,LAPRIDA 854,RA-5000 CORDOBA,ARGENTINA. NR 82 TC 11 Z9 11 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 S WOODLAWN AVE, CHICAGO, IL 60637 SN 0067-0049 J9 ASTROPHYS J SUPPL S JI Astrophys. J. Suppl. Ser. PD APR PY 1997 VL 109 IS 2 BP 397 EP 416 DI 10.1086/312982 PG 20 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA WZ188 UT WOS:A1997WZ18800005 ER PT J AU Woodruff, DS Mulvey, M AF Woodruff, DS Mulvey, M TI Neotropical schistosomiasis: African affinities of the host snail Biomphalaria glabrata (Gastropoda: Planorbidae) SO BIOLOGICAL JOURNAL OF THE LINNEAN SOCIETY LA English DT Article DE allozymes; biogeography; dispersal; Gastropoda; introduced species; phylogeny; phylogeography; Schistosoma mansoni ID GENETIC-VARIATION; POPULATION-GENETICS; LABORATORY STRAINS; ALLOZYME VARIATION; PFEIFFERI KRAUSS; LINKAGE ANALYSIS; MANSONI; DIFFERENTIATION; RESISTANCE; INFECTION AB Schistosoma mansoni, the blood fluke responsible for human intestinal schistosomiasis in the Neotropics, was imported repeatedly with African slaves during the period 1500-1800. This trematode, and its intermediate host snails of the genus Biomphalaria, are widely distributed across Africa and the disease is thought to have quickly become established in South America and the West Indies because of the presence of an endemic susceptible congener, B. glabrata. We compared B. glabrata with four other Neotropical and three African species of Biomphalaria using 20 allozyme loci and found that it is phenetically and phylogenetically more like the African species; both parasite and American host snail are apparently of historically or geologically recent African origin. Furthermore, genetic distances, cladistic analyses and fossil data suggest the African Biomphalaria species may themselves have evolved from Neotropical founders following an initial trans-Atlantic dispersal in the reverse direction 2.3-4.5 Mya. Interpretation of existing patterns remains problematic as few African snails have been characterized genetically and bath B. glabrata and African B. pfeifferi to comprise several cryptic species. (C) 1997 The Linnean Society of London. C1 UNIV CALIF SAN DIEGO,CTR GENET MOL,LA JOLLA,CA 92093. UNIV GEORGIA,SAVANNAH RIVER ECOL LAB,AIKEN,SC 29802. RP Woodruff, DS (reprint author), UNIV CALIF SAN DIEGO,DEPT BIOL,LA JOLLA,CA 92093, USA. NR 75 TC 34 Z9 35 U1 1 U2 2 PU ACADEMIC PRESS LTD PI LONDON PA 24-28 OVAL RD, LONDON, ENGLAND NW1 7DX SN 0024-4066 J9 BIOL J LINN SOC JI Biol. J. Linnean Soc. PD APR PY 1997 VL 60 IS 4 BP 505 EP 516 DI 10.1006/bijl.1996.0116 PG 12 WC Evolutionary Biology SC Evolutionary Biology GA WY265 UT WOS:A1997WY26500005 ER PT J AU Nordahl, TE Bieqon, A Paller, K Kusubov, N Jaqust, W AF Nordahl, TE Bieqon, A Paller, K Kusubov, N Jaqust, W TI Prefrontal abnormalities observed via the PET-600 in depressed patients performing a memory task SO BIOLOGICAL PSYCHIATRY LA English DT Meeting Abstract C1 UNIV CALIF DAVIS,DEPT PSYCHIAT,BERKELEY,CA 94720. UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,CTR FUNCT IMAGING,BERKELEY,CA 94720. NR 0 TC 0 Z9 0 U1 0 U2 0 PU ELSEVIER SCIENCE INC PI NEW YORK PA 655 AVENUE OF THE AMERICAS, NEW YORK, NY 10010 SN 0006-3223 J9 BIOL PSYCHIAT JI Biol. Psychiatry PD APR 1 PY 1997 VL 41 SU 7 BP 54 EP 54 PG 1 WC Neurosciences; Psychiatry SC Neurosciences & Neurology; Psychiatry GA WQ709 UT WOS:A1997WQ70900056 ER PT J AU Saxton, MJ AF Saxton, MJ TI Single-particle tracking: The distribution of diffusion coefficients SO BIOPHYSICAL JOURNAL LA English DT Article ID LATERAL DIFFUSION; BIOLOGICAL-MEMBRANES; DISORDERED MEDIA; PLASMA-MEMBRANE; LIPID DOMAINS; MOBILITY; MOLECULES; FIBROBLASTS; MICROSCOPY; MOVEMENTS AB In single-particle tracking experiments, the diffusion coefficient D may be measured from the trajectory of an individual particle in the cell membrane. The statistical distribution of single-trajectory diffusion coefficients is examined by Monte Carlo calculations. The width of this distribution may be useful as a measure of the heterogeneity of the membrane and as a test of models of hindered diffusion in the membrane. For some models, the distribution of the short-range diffusion coefficient is much narrower than the observed distribution for proteins diffusing in cell membranes. To aid in the analysis of single-particle tracking measurements, the distribution of D is examined for various definitions of D and for various trajectory lengths. C1 UNIV CALIF BERKELEY,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 [GM38133] NR 46 TC 323 Z9 327 U1 7 U2 71 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 1997 VL 72 IS 4 BP 1744 EP 1753 PG 10 WC Biophysics SC Biophysics GA WP369 UT WOS:A1997WP36900025 PM 9083678 ER PT J AU Tinsley, BA Beard, KV AF Tinsley, BA Beard, KV TI Links between variations in solar activity, atmospheric conductivity, and clouds: An informal workshop SO BULLETIN OF THE AMERICAN METEOROLOGICAL SOCIETY LA English DT Editorial Material ID AEROSOL-PARTICLES; SUPERCOOLED WATER; RAINDROPS; DROPS C1 LOS ALAMOS NATL LAB,LOS ALAMOS,NM. UNIV ILLINOIS,DEPT ATMOSPHER SCI,CHAMPAIGN,IL 61820. ILLINOIS STATE WATER SURVEY,CHAMPAIGN,IL 61820. RP Tinsley, BA (reprint author), UNIV TEXAS,CTR SPACE SCI,MS FO22,POB 830688,RICHARDSON,TX 75083, USA. NR 12 TC 11 Z9 11 U1 0 U2 2 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0003-0007 J9 B AM METEOROL SOC JI Bull. Amer. Meteorol. Soc. PD APR PY 1997 VL 78 IS 4 BP 685 EP 687 PG 3 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA XA634 UT WOS:A1997XA63400006 ER PT J AU Kanciruk, P AF Kanciruk, P TI Pricing policy for federal research data SO BULLETIN OF THE AMERICAN METEOROLOGICAL SOCIETY LA English DT Letter RP Kanciruk, P (reprint author), OAK RIDGE NATL LAB,DIV ENVIRONM SCI,ENVIRONM INFORMAT ANAL PROGRAM,POB 2008,OAK RIDGE,TN 37831, USA. NR 0 TC 3 Z9 3 U1 0 U2 0 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0003-0007 J9 B AM METEOROL SOC JI Bull. Amer. Meteorol. Soc. PD APR PY 1997 VL 78 IS 4 BP 691 EP 692 PG 2 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA XA634 UT WOS:A1997XA63400008 ER PT J AU Rodgers, AJ Ni, JF Hearn, TM AF Rodgers, AJ Ni, JF Hearn, TM TI Propagation characteristics of short-period Sr and Lg in the Middle East SO BULLETIN OF THE SEISMOLOGICAL SOCIETY OF AMERICA LA English DT Article ID SEISMIC-WAVE PROPAGATION; REGIONAL DISTANCES; TIBETAN PLATEAU; CRUSTAL PHASES; UPPER MANTLE; BENEATH; BELT; ATTENUATION; TEMPERATURE; VELOCITIES AB We present propagation characteristics of the short-period regional seismic phases Sn and Lg for the Middle East. Digital waveform data from the Iranian Long Period Array (ILPA) and the Global Seismic Network (GSN) stations ABKT (Alibek, Turkmenistan), ANTO (Ankara, Turkey), KEG (Kottamya, Egypt), and KIV (Kislovodsk, Georgia) were used in this study, Three-component rotated seismograms were bandpass filtered (0.5 to 5.0 Hz) and examined for the presence and strength (amplitude) of Sn and Lg relative to the Pn and Pg phases. The short-period Sn and Lg waveforms show great variability, Sn propagates efficiently for paths crossing the Mediterranean, Black, and Caspian Seas as well as for paths passing north of the Greater Caucasus, Alborz, and Kopet-Dag Mountains. Generally, Sn is not observed or propagates inefficiently for paths with segments beneath the Turkish plateau and northern Iranian plateau, consistent with a previous study by Kadinsky-Cade et al. (1981). This study finds that the zone of inefficient Sn propagation coincides with a zone of low Pn velocities (<7.9 km/sec) determined by Hearn and Ni (1994) from Pn tomography. Lg is consistently not observed for paths crossing the Mediterranean, Black, and Caspian Seas, Lg propagates efficiently for paths crossing the northern Arabian shield. Generally, Lg propagates efficiently for paths contained within the Turkish-Iranian plateau. Paths in the Middle East greater than about 2000 km consistently show no or little Lg energy. The correspondence of zones of inefficient Sn propagation and low Pn velocities suggests that high temperatures and partial melt lie at shallow depths in the upper mantle beneath the Turkish plateau and northern Iranian plateau. The presence of water, presumably due to subduction of hydrated oceanic crust, lowers the solidus temperature and enhances partial melt. Lg is blocked by oceanic crustal structures as well as by structural and topographic variations associated with tectonic boundaries. C1 NEW MEXICO STATE UNIV,DEPT PHYS,LAS CRUCES,NM 88003. RP Rodgers, AJ (reprint author), LAWRENCE LIVERMORE NATL LAB,DIV EARTH SCI,L-222,LIVERMORE,CA 94551, USA. RI Rodgers, Arthur/E-2443-2011 NR 30 TC 59 Z9 60 U1 0 U2 0 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 1997 VL 87 IS 2 BP 396 EP 413 PG 18 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA WW750 UT WOS:A1997WW75000010 ER PT J AU Niewiarowski, PH Congdon, JD Dunham, AE Vitt, LJ Tinkle, DW AF Niewiarowski, PH Congdon, JD Dunham, AE Vitt, LJ Tinkle, DW TI Tales of lizard tails: Effects of tail autotomy on subsequent survival and growth of free-ranging hatchling Uta stansburiana SO CANADIAN JOURNAL OF ZOOLOGY-REVUE CANADIENNE DE ZOOLOGIE LA English DT Article ID IBERIAN ROCK-LIZARD; NATURAL-SELECTION; SCINCELLA-LATERALIS; LACERTA-MONTICOLA; ANOLIS LIZARDS; BODY GROWTH; SOCIAL COST; RATES; SIZE; REPRODUCTION AB Potential costs and benefits of tail autotomy in lizards have been inferred almost exclusively from experimental study in semi-natural enclosures and from indirect comparative evidence from natural populations. We present complementary evidence of the costs of tail autotomy to the lizard Uta stansburiana from detailed demographic study of a natural population. On initial capture, we broke the tails of a large sample of free-ranging hatchlings (560) and left the tails of another large sample (455) intact, and then followed subsequent hatchling growth and survival over a 3-year period. Surprisingly, in 1 out of the 3 years of study, survival of female hatchlings with broken tails exceeded that of female hatchlings with intact tails. Furthermore, no effects of tail loss on survivorship were detected for male hatchlings. However, in 2 years when recaptures were very frequent (1961, 1962), growth rates of hatchlings with broken tails were significantly slower than those of their counterparts with intact tails. We discuss our results in the broader context of estimating the relative costs and benefits of tail autotomy in natural populations. and suggest that long-term demographic studies will provide the best opportunity to assess realized fitness costs and benefits with minimum bias. We also describe how experimentally induced tail autotomy can be used as a technique to complement experimental manipulation of reproductive investment in the study of life-history trade-offs. C1 UNIV GEORGIA,SAVANNAH RIVER ECOL LAB,AIKEN,SC 29802. UNIV PENN,LEIDY LABS,DEPT BIOL,PHILADELPHIA,PA 19104. UNIV OKLAHOMA,OKLAHOMA MUSEUM NAT HIST,NORMAN,OK 73019. UNIV MICHIGAN,ZOOL MUSEUM,ANN ARBOR,MI 48109. RP Niewiarowski, PH (reprint author), UNIV AKRON,DEPT BIOL,AKRON,OH 44325, USA. NR 41 TC 53 Z9 55 U1 0 U2 8 PU NATL RESEARCH COUNCIL CANADA PI OTTAWA PA RESEARCH JOURNALS, MONTREAL RD, OTTAWA ON K1A 0R6, CANADA SN 0008-4301 J9 CAN J ZOOL JI Can. J. Zool.-Rev. Can. Zool. PD APR PY 1997 VL 75 IS 4 BP 542 EP 548 DI 10.1139/z97-067 PG 7 WC Zoology SC Zoology GA XB777 UT WOS:A1997XB77700005 ER PT J AU Gust, DA Arculus, RJ Kersting, AB AF Gust, DA Arculus, RJ Kersting, AB TI Aspects of magma sources and processes in the Honshu arc SO CANADIAN MINERALOGIST LA English DT Article; Proceedings Paper CT Joint Annual Meeting of Geological-Association-of-Canada / Mineralogical-Association-of-Canada CY MAY, 1995 CL VICTORIA, CANADA SP Geol Assoc Canada, Mineral Assoc Canada DE arc magmatism; petrogenesis; lithosphere; source; trace-element geochemistry; isotopic data; Honshu arc; Japan ID SOUTH CHINA BASIN; IZU-BONIN ARC; ISLAND-ARC; NORTHEAST JAPAN; VOLCANIC-ROCKS; ISOTOPE CHARACTERISTICS; SUBDUCTION ZONES; TRACE-ELEMENTS; MANTLE WEDGE; MARGIN AB The volcanoes of the northern Izu - south-central Honshu and northeastern Honshu area, Japan, occur in a region where variables such as age, composition, and nature of the sediment cover of the subducting plate are relatively uniform. In this study, we attempt to isolate some of the variables associated with suprasubduction zone (SSZ) magma genesis, in order to provide insight into the nature of sources and petrogenetic processes. The chemical compositions of selected parental and evolved magmas in fifteen Plio-Pleistocene centers along the strike of the volcanic front allow us to assess the significance of over-riding lithospheric input for SSZ magmatism. These volcanoes are distributed across a number of major terrane boundaries, including the lithosphere-penetrating Tanakura Tectonic Line. Compositions range from basalt to rhyolite, with a preponderance of basaltic andesite and andesite; an exception is basalt-dominated Fuji. Most basalts are significantly fractionated, with low MgO (<7 wt%), Mg# <50, and low Ni (<50 ppm). Significant differences among volcanic suites are established on the basis of isotopic (Pb, Sr, and Nd), major- and trace-element data. The predominant source of these magmas is a relatively refractory (compared to mid-ocean ridge basalt) mantle-wedge area, with subchondritic Nb/Zr and Zr/Hf. A number of volcanoes also have low Zr/Y (< MORB), but several have both elevated Zr/Y (>3) and Dy/Yb, indicative of garnet involvement in their genesis. The Nd and Sr isotope ratios also indicate regional Variations in chemical composition of the source(s) (long-term depleted to enriched). Pb isotopic data are distinctive in northern Honshu, with elevated Pb-208/Pb-204 and Pb-207/Pb-204 at specific Pb-206/Pb-204 (south versus north of the Tanakura Tectonic Line), are collectively elevated above the Northern Hemisphere Reference Line (and Izu-Mariana arcs), appear similar to portions of the Philippines and Tertiary basalts of eastern Asia, and probably reflect an Asian lithospheric heritage. The combined trace-element and isotope geochemistry of parental basalts distinguish different domains within the Izu-Bonin, central and northeastern Honshu arcs. The ultimate cause of these is most likely multicomponent, and some crustal assimilation is highly probable. However, these domains may in some part represent magma interaction with a subcontinental lithosphere dominated by Indian-Ocean-type mantle, or alternatively, derivation from an Indian-Ocean-type asthenosphere. The correlation of some magma compositional characteristics with nature of the basement terrane shows that the lithosphere plays a subtle but significant role in determining parental island-are basalt characteristics. The longevity and character of the continental lithosphere in Asian margin are systems, and its interaction with asthenosphere-derived melts, is an important process in island-are basalt genesis. C1 AUSTRALIAN NATL UNIV,DEPT GEOL,NATL KEY CTR GEOCHEM EVOLUT & METALLOGENY CONTINE,CANBERRA,ACT 0200,AUSTRALIA. LAWRENCE LIVERMORE NATL LAB,ISOTOPE SCI DIV,LIVERMORE,CA 94551. RP Gust, DA (reprint author), QUEENSLAND UNIV TECHNOL,SCH GEOL,GPO BOX 2434,BRISBANE,QLD 4001,AUSTRALIA. NR 69 TC 29 Z9 29 U1 0 U2 2 PU MINERALOGICAL ASSOC CANADA PI NEPEAN PA CITYVIEW 78087, NEPEAN ON K2G 5W2, CANADA SN 0008-4476 J9 CAN MINERAL JI Can. Mineral. PD APR PY 1997 VL 35 BP 347 EP 365 PN 2 PG 19 WC Mineralogy SC Mineralogy GA XF229 UT WOS:A1997XF22900007 ER PT J AU Cullinane, C Weber, CA Dianov, G Bohr, VA AF Cullinane, C Weber, CA Dianov, G Bohr, VA TI Restoration of preferential and strand specific gene repair in group 2 Chinese hamster ovary mutants (UV5) by the XPD (ERCC2) gene SO CARCINOGENESIS LA English DT Article ID NUCLEOTIDE EXCISION-REPAIR; PIGMENTOSUM GROUP-D; COMPLEMENTATION GROUP-D; RNA-POLYMERASE-II; DNA-REPAIR; XERODERMA-PIGMENTOSUM; SACCHAROMYCES-CEREVISIAE; MOLECULAR CHARACTERIZATION; TRANSCRIPTION FACTOR; PYRIMIDINE DIMERS AB It has recently been reported that the XPD (ERCC2) gene is an integral component of the basal transcription factor TFIIH. We have studied the direct role of this repair gene on the fine structure of DNA repair in hamster cells, The gene and strand specific DNA repair of UV induced pyrimidine dimers was determined in wild-type hamster cells, in hamster cells harboring a mutation in the gene homologous to the XPD gene and in mutant cells transfected with the human XPD gene, In the mutant cells, strand specific repair was severely deficient. In the transfected cells, preferential and strand specific gene repair were restored to wild-type levels, The results of the current study clearly demonstrate a direct role for the XPD gene product both in the preferential repair and bulk repair of pyrimidine dimers as well as its high functional conservation between rodent and human cells. An in vitro transcription assay was employed to investigate whether RNA polymerase II mediated transcription was also affected by the transfection with the XPD gene, No change in transcription between the mutant and transfected cells was observed, This suggests that the role of XPD in repair can be distinguished from its role in TFIIH dependent transcription initiation, Different functional domains of XPD appear to be necessary for repair versus transcription. C1 LAWRENCE LIVERMORE NATL LAB,BIOL & BIOTECHNOL RES PROGRAM,LIVERMORE,CA 94551. RP Cullinane, C (reprint author), NIA,INST GENET MOL,4940 EASTERN AVE,BALTIMORE,MD 21224, USA. NR 46 TC 9 Z9 9 U1 0 U2 0 PU OXFORD UNIV PRESS PI OXFORD PA GREAT CLARENDON ST, OXFORD, ENGLAND OX2 6DP SN 0143-3334 J9 CARCINOGENESIS JI Carcinogenesis PD APR PY 1997 VL 18 IS 4 BP 681 EP 686 DI 10.1093/carcin/18.4.681 PG 6 WC Oncology SC Oncology GA WT305 UT WOS:A1997WT30500012 PM 9111200 ER PT J AU Okonogi, H Ushijima, T Zhang, XB Heddle, JA Suzuki, T Sofuni, T Felton, JS Tucker, JD Sugimura, T Nagao, M AF Okonogi, H Ushijima, T Zhang, XB Heddle, JA Suzuki, T Sofuni, T Felton, JS Tucker, JD Sugimura, T Nagao, M TI Agreement of mutational characteristics of heterocyclic amines in lacI of the Big Blue(R) mouse with those in tumor related genes in rodents SO CARCINOGENESIS LA English DT Article ID TRANSGENIC MICE; COOKED FOODS; 2-AMINO-1-METHYL-6-PHENYLIMIDAZO<4,5-B>PYRIDINE; CANCER; 2-AMINO-3-METHYLIMIDAZO<4,5-F>QUINOLINE; CARCINOGENS; SPECTRA; ADDUCT AB The mutational spectra of carcinogenic heterocyclic amines (HCAs), 2-amino-3,4-dimethylimidazo[4,5-b]quinoline (MeIQ), 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) and 2-amino-9H-pyrido[2,3-b]indole (A alpha C) were studied in the colon of Big Blue(R) mice, In 90, 115 and 105 lacI mutants from mice fed 300 p.p.m. MeIQ, 400 p.p.m. PhIP and 800 p.p.m. A alpha C, respectively, 92, 115 and 105 mutations were identified, G:C-->T:A transversions predominated with these HCAs, Mutational hot spots for base-substitution mutations caused by MeIQ, PhIP and A alpha C were in distinct sequence contexts; at 5'-GC-3', in runs of guanine and in 5'-CGT-3', respectively, Further, 30 of 115 (26%) PhIP-induced mutations were G:C base pair deletions, and eight of these deletions were in 5'-GGGA-3'. The mutational characteristics of MeIQ in the lad gene coincided well with those in the Ha-ras gene of MeIQ-induced mouse forestomach tumors and rat Zymbal gland tumors, The characteristic single-base deletion induced by PhIP in the lad gene also coincided well with those in the Ape gene of PhIP-induced rat colon tumors, These results suggest that the mutational characteristics of each chemical are conserved across different genes in different species. C1 NATL CANC CTR,RES INST,DIV CARCINOGENESIS,CHUO KU,TOKYO 104,JAPAN. YORK UNIV,DEPT BIOL,TORONTO,ON M3J 1P3,CANADA. NATL INST HLTH SCI,DIV GENET & MUTAGENESIS,SETAGAYA KU,TOKYO 158,JAPAN. LAWRENCE LIVERMORE NATL LAB,BIOL & BIOTECHNOL RES PROGRAM,LIVERMORE,CA 94551. NR 24 TC 54 Z9 55 U1 0 U2 0 PU OXFORD UNIV PRESS PI OXFORD PA GREAT CLARENDON ST, OXFORD, ENGLAND OX2 6DP SN 0143-3334 J9 CARCINOGENESIS JI Carcinogenesis PD APR PY 1997 VL 18 IS 4 BP 745 EP 748 DI 10.1093/carcin/18.4.745 PG 4 WC Oncology SC Oncology GA WT305 UT WOS:A1997WT30500021 PM 9111209 ER PT J AU Robinson, A AF Robinson, A TI Making light work of spectroscopy SO CHEMISTRY IN BRITAIN LA English DT Article RP Robinson, A (reprint author), LAWRENCE BERKELEY NATL LAB,ADV LIGHT SOURCE CTR,SCI OUTREACH & COMMUN CTR,BERKELEY,CA 94720, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU ROYAL SOC CHEMISTRY PI CAMBRIDGE PA THOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON ROAD, CAMBRIDGE, CAMBS, ENGLAND CB4 4WF SN 0009-3106 J9 CHEM BRIT JI Chem. Br. PD APR PY 1997 VL 33 IS 4 BP 50 EP 53 PG 4 WC Chemistry, Multidisciplinary SC Chemistry GA WT303 UT WOS:A1997WT30300061 ER PT J AU Schulz, DL Pehnt, M Rose, DH Urgiles, E Cahill, AF Niles, DW Jones, KM Ellingson, RJ Curtis, CJ Ginley, DS AF Schulz, DL Pehnt, M Rose, DH Urgiles, E Cahill, AF Niles, DW Jones, KM Ellingson, RJ Curtis, CJ Ginley, DS TI CdTe thin films from nanoparticle precursors by spray deposition SO CHEMISTRY OF MATERIALS LA English DT Article ID SEMICONDUCTOR NANOCRYSTALS; PHOTOVOLTAIC CELLS; MATERIALS SCIENCE; SOLAR-CELLS; ELECTRODES; PARTICLES; CHEMISTRY; CLUSTERS; HYDROGEN; ENERGY AB The formation of CdTe thin films by spray deposition using nanoparticle colloids has been investigated. Employing a metathesis approach, cadmium iodide is reacted with sodium telluride in methanol solvent, resulting in the formation of soluble NaI and insoluble CdTe nanoparticles. After appropriate chemical workup, methanol-capped CdTe colloids were isolated. CdTe colloids prepared by this method exhibit a dependence of the nanoparticle diameter upon reaction temperature as determined by UV-visible spectroscopy (UV-vis), X-ray diffraction (XRD), and transmission electron microscopy (TEM). CdTe thin-film formation was performed by spray depositing the 25-75 Angstrom diameter nanoparticle colloids according to a one- or two-step method. Films derived from a one-step approach were sprayed onto substrates at elevated temperatures (T-dep = 280-440 degrees C) with no further thermal treatment. Two-step films were sprayed at lower temperatures (T-dep = 25-125 degrees C) and were subjected to subsequent thermal treatments (T-anneal = 250-500 degrees C) in argon or forming gas (10% H-2 in N-2) ambients. The effects of a CdCl2 treatment were also investigated for CdTe films on both 7059 glass and CdS on SnO2-coated 7059 glass. The CdTe films were characterized by XRD, X-ray photoelectron spectroscopy (XPS), and atomic force microscopy (AFM). Phase-pure cubic CdTe formation was observed by XRD for two-step derived films (400 degrees C in forming gas) while one-step films were composed of the cubic CdTe and an oxide phase. XPS analysis of five films processed at 400 degrees C and a variety of conditions showed that while CdTe films produced by the one-step method contained no Na or C and substantial O, two-step films subjected to a CdCl2 treatment showed reduced O but increased C content. AFM gave CdTe grain sizes of similar to 0.1-0.3 and similar to 0.3-0.7 mu m for a one-step film sprayed at 400 degrees C and a two-step film annealed at 400 degrees C, respectively. The potential of employing CdTe nanoparticles toward photovoltaic technologies is discussed. RP Schulz, DL (reprint author), NATL RENEWABLE ENERGY LAB,1617 COLE BLVD,GOLDEN,CO 80401, USA. RI Ellingson, Randy/H-3424-2013 NR 52 TC 16 Z9 16 U1 0 U2 13 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 1997 VL 9 IS 4 BP 889 EP 900 DI 10.1021/cm9601547 PG 12 WC Chemistry, Physical; Materials Science, Multidisciplinary SC Chemistry; Materials Science GA WU686 UT WOS:A1997WU68600005 ER PT J AU Hayes, S vanWullen, L Eckert, H Even, WR Crocker, RW Zhang, ZM AF Hayes, S vanWullen, L Eckert, H Even, WR Crocker, RW Zhang, ZM TI Solid-state NMR strategies for the structural investigation of carbon-based anode materials SO CHEMISTRY OF MATERIALS LA English DT Article ID MAGNETIC-RESONANCE SPECTRA; NANODISPERSED SILICON; LITHIUM; GRAPHITE; INTERCALATION; C-13; N-15 AB Multinuclear solid-state NMR spectroscopy is a well-suited technique for structural analysis of amorphous carbon-based anode materials generated from pyrolysis of poly(methacrylonitrile/divinylbenzene) copolymers. Results are presented for the untreated polymeric precursor, the oxidatively stabilized material, and amorphous carbons prepared by high-temperature pyrolysis. In addition, structural effects of silicon dopants and lithium intercalants are studied. The structural changes occurring during the processes of oxidative stabilization and carbonization up to 700 degrees C are effectively monitored by C-13 and N-15 cross-polarization/magic angle spinning methods. The peak assignments are assisted by short contact time and dipolar dephasing experiments. For carbons prepared at higher pyrolysis temperatures this technique is limited by the low structural proton content. For such materials, the H-1 chemical shifts of sorbed water molecules are found to be linearly correlated with the pyrolysis temperature. This effect is attributed to surface ordering phenomena. Si-29 CPMAS spectra of carbons prepared with tetravinylsilane comonomers indicate that the silicon component is oxidized during the stabilization process. Li-7 MAS NMR is well suited to differentiate between electrochemically relevant intercalated species and other species that are unable to participate in the intercalation due to parasitic processes. For the intercalated species, a linear correlation of the Li-7 chemical shift with the charging state of the carbon is observed. C1 UNIV CALIF SANTA BARBARA,DEPT CHEM,SANTA BARBARA,CA 93106. SANDIA NATL LABS,LIVERMORE,CA 94551. EVEREADY BATTERY CO INC,WESTLAKE,OH 44145. RI Hayes, Sophia/C-1075-2008; Eckert, Hellmut/G-3176-2012 OI Hayes, Sophia/0000-0002-2809-6193; NR 43 TC 13 Z9 13 U1 1 U2 16 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 1997 VL 9 IS 4 BP 901 EP 911 DI 10.1021/cm960389i PG 11 WC Chemistry, Physical; Materials Science, Multidisciplinary SC Chemistry; Materials Science GA WU686 UT WOS:A1997WU68600006 ER PT J AU Gray, MJ Jasper, JD Wilkinson, AP Hanson, JC AF Gray, MJ Jasper, JD Wilkinson, AP Hanson, JC TI Synthesis and synchrotron microcrystal structure of an aluminophosphate with chiral layers containing Lambda tris(ethylenediamine)cobalt(III) SO CHEMISTRY OF MATERIALS LA English DT Article ID SMALL CRYSTAL; ZEOLITE-BETA; RADIATION AB A chiral aluminophosphate, d-Co(en)(3).Al3P4O16.3H(2)O, has been synthesized using optically pure d-Co(en)(3)(3+) as a templating agent (en = 1,2-diaminoethane). The structure of the material has been determined from a small single crystal using synchrotron radiation and imaging plate detection. The aluminophosphate contains chiral macroanionic sheets similar to those previously reported in trans-Co(dien)(2).Al3P4O16.xH(2)O (dien = diethylenetriamine). Co(C2N2H8)(3).Al3P4O16.3H(2)O, M-r = 754.1, orthorhombic, C222(1), a = 8.502(6) Angstrom, b = 14.620(6) Angstrom, c = 20.890(11) Angstrom, V = 2597(3) Angstrom(3), Z = 4, rho(calc) = 1.929 g cm(-3), rho(abs) = 1.95 g cm(-3), lambda = 1.2007(5) Angstrom, mu = 9.389 mm(-1), F(000) = 1526, T = 293 K, R-F = 0.084 for 872 reflections I > 2 sigma(I). C1 GEORGIA INST TECHNOL,SCH CHEM & BIOCHEM,ATLANTA,GA 30332. BROOKHAVEN NATL LAB,DEPT CHEM,UPTON,NY 11973. RI Wilkinson, Angus/C-3408-2008; Hanson, jonathan/E-3517-2010 OI Wilkinson, Angus/0000-0003-2904-400X; NR 35 TC 90 Z9 91 U1 5 U2 13 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 1997 VL 9 IS 4 BP 976 EP 980 DI 10.1021/cm9605429 PG 5 WC Chemistry, Physical; Materials Science, Multidisciplinary SC Chemistry; Materials Science GA WU686 UT WOS:A1997WU68600015 ER PT J AU Kleinke, H Franzen, HF AF Kleinke, H Franzen, HF TI Intercalation of nickel into the new ternary phosphide Hf5NiP3 SO CHEMISTRY OF MATERIALS LA English DT Article ID CLUSTERS AB Hf5Ni1+xP3, synthesized by are-melting HfP, Hf, and Ni in Hf:Ni:P ratios varying between 5:1:3 and 2:1:1, crystallizes in a filled Hf5CoP3 structure type, space group Pnma, lattice constants a = 17.021(3) Angstrom, b = 3.596(2) Angstrom, c = 10.146(2) A, V = 621.0(8) Angstrom(3) for x = 0.130(8). Its structure consists of an extended framework of connected channels formed by hafnium. Each channel is filled with an infinite -Ni-P- zigzag chain, whereas two other P sites are located in trigonal prismatic voids of the Hf sublattice. In contrast to Hf5Co1+xP3-x, where additional Co atoms replace P atoms, additional Ni atoms in Hf5Ni1+xP3 can occupy a trigonal Hf-6 prism, three-capped by P atoms. No Ni/P exchange has been observed. However, Hf5Ni1+xP3 is assumed to be metallic, corresponding to the calculated band structure as well as to the Pauli paramagnetism experimentally obtained. C1 IOWA STATE UNIV SCI & TECHNOL,US DOE,AMES LAB,AMES,IA 50011. NR 21 TC 9 Z9 9 U1 1 U2 7 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 1997 VL 9 IS 4 BP 1030 EP 1035 DI 10.1021/cm960620s PG 6 WC Chemistry, Physical; Materials Science, Multidisciplinary SC Chemistry; Materials Science GA WU686 UT WOS:A1997WU68600022 ER PT J AU Battle, PD Cox, DE Green, MA Millburn, JE Spring, LE Radaelli, PG Rosseinsky, MJ Vente, JF AF Battle, PD Cox, DE Green, MA Millburn, JE Spring, LE Radaelli, PG Rosseinsky, MJ Vente, JF TI Antiferromagnetism, ferromagnetism, and phase separation in the GMR system Sr2-xLa1+xMn2O7 SO CHEMISTRY OF MATERIALS LA English DT Article ID INSULATOR-METAL TRANSITION; CHARGE AB Neutron and synchrotron X-ray powder diffraction techniques have been used to refine the crystal and magnetic structures of the n = 2 Ruddlesden-Popper (RP) system Sr2LaMn2O7. The sample is shown to be biphasic, although both phases are of the RP type and have similar structural parameters. The majority phase (81%) adopts a collinear antiferromagnetic structure below similar to 210 K whereas the minority phase is ferromagnetically ordered below similar to 125 K. The ordered magnetic moments lie in the xy plane in both phases. The behavior observed is discussed in terms of the interplay between structural and electronic factors. Comparison with data obtained previously by other workers leads to the conclusion that our results have some general significance in the study of n = 2 RP systems. C1 BROOKHAVEN NATL LAB,DEPT PHYS,UPTON,NY 11973. INST MAX VON LAUE PAUL LANGEVIN,F-38042 GRENOBLE 9,FRANCE. RP Battle, PD (reprint author), UNIV OXFORD,INORGAN CHEM LAB,S PARKS RD,OXFORD OX1 3QR,ENGLAND. RI Radaelli, Paolo/C-2952-2011 OI Radaelli, Paolo/0000-0002-6717-035X NR 35 TC 77 Z9 77 U1 2 U2 10 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 1997 VL 9 IS 4 BP 1042 EP 1049 DI 10.1021/cm960632d PG 8 WC Chemistry, Physical; Materials Science, Multidisciplinary SC Chemistry; Materials Science GA WU686 UT WOS:A1997WU68600024 ER PT J AU Chipera, SJ Bish, DL AF Chipera, SJ Bish, DL TI Equilibrium modeling of clinoptilolite-analcime equilibria at Yucca Mountain, Nevada, USA SO CLAYS AND CLAY MINERALS LA English DT Article DE analcime; clinoptilolite; modeling; stability; thermodynamic; zeolite ID THERMODYNAMIC PROPERTIES; SYSTEM NA2O-K2O-CAO-MGO-FEO-FE2O3-AL2O3-SIO2-TIO2-H2O-CO2; SILICATE MINERALS; HEAT-CAPACITY; ION-EXCHANGE; ZEOLITES; TEMPERATURE; HEULANDITE; PREDICTION; CHEMISTRY AB Yucca Mountain, Nevada, is being investigated to determine its suitability to host a potential high-level radioactive waste respository. An important reason for its choice as a potential repository site was the presence of thick zeolite-rich horizons in the altered volcanic tuffs that compose the mountain. Clinoptilolite is the most abundant zeolite at Yucca Mountain and may be important in radionuclide retardation and in determining hydrologic properties. Therefore, it is necessary to understand the geochemical conditions affecting its long-term stability. For example, it has been suggested that long-term, repository-induced heating of the rocks at Yucca Mountain may lead to the transformation of clinoptilolite to analcime, thereby significantly affecting the hydrologic properties and retardation capabilities of the rock. Thermodynamic modeling of clinoptilolite-analcime equilibria was conducted with the program Ge0/Calc PTA-SYSTEM using estimated thermodynamic data for measured chemical compositions of clinoptilolite and analcime at Yucca Mountain. Log[(nK(+))(2)/aCa(2+)] versus log[(aNa(+))(2)/aCa(2+)] diagrams were calculated to model the conditions under which clinoptilolite may transform to analcime. Temperature, relative cation abundances and silica activity are all important factors in determining clinoptilolite-analcime equilibria. Increased Na+ concentrations in either clinoptilolite or the fluid phase, increased clinoptilolite K+ concentration, increased temperature and decreased aqueous silica activity all stabilize analcime relative to clinoptilolite, assuming present-day Yucca Mountain water compositions. However, increased Ca2+ concentrations in either clinoptilolite or the fluid phase, increased aqueous K concentration and increased Al:Si ratios in clinoptilolite (heulandite) all stabilize clinoptilolite with respect to analcime. Assuming well J-13 water as the analog chemistry for Yucca Mountain water, clinoptilolite should remain stable with respect to analcime if temperatures in the clinoptilolite-bearing horizons do not significantly exceed 100 degrees C. Even if temperatures rise significantly (for example, to 150 degrees C), not all clinoptilolite should alter to analcime. Perhaps more importantly, thermodynamic modeling suggests that some Yucca Mountain clinoptilolites, particularly those rich in Ca and Al, will remain stable at elevated temperatures, even with an aqueous silica activity at quartz saturation. RP Chipera, SJ (reprint author), LOS ALAMOS NATL LAB,MAIL STOP D469,LOS ALAMOS,NM 87545, USA. NR 68 TC 21 Z9 22 U1 1 U2 3 PU CLAY MINERALS SOCIETY PI BOULDER PA PO BOX 4416, BOULDER, CO 80306 SN 0009-8604 J9 CLAY CLAY MINER JI Clay Clay Min. PD APR PY 1997 VL 45 IS 2 BP 226 EP 239 DI 10.1346/CCMN.1997.0450211 PG 14 WC Chemistry, Physical; Geosciences, Multidisciplinary; Mineralogy; Soil Science SC Chemistry; Geology; Mineralogy; Agriculture GA XN821 UT WOS:A1997XN82100011 ER PT J AU Naggert, JK Recinos, A Lamerdin, JE Krauss, RM Nishina, PM AF Naggert, JK Recinos, A Lamerdin, JE Krauss, RM Nishina, PM TI The atherogenic lipoprotein phenotype is not caused by a mutation in the coding region of the low density lipoprotein receptor gene SO CLINICAL GENETICS LA English DT Article DE atherosclerosis; ATHS; genotyping; LDLR; LDL subclass ID HUMAN LDL-RECEPTOR; HETEROZYGOUS FAMILIAL HYPERCHOLESTEROLEMIA; SUBCLASS PATTERNS; DNA-POLYMERASE; POLYMORPHISM; AMPLIFICATION; INHERITANCE; PROMOTER; SEQUENCE; LOCUS AB The atherogenic lipoprotein phenotype (ALP) is a common heritable trait characterized by a predominance of small, dense low density lipoprotein particles (subclass pattern B), increased levels of triglyceride-rich lipoproteins, reductions in high density lipoproteins, and an increased risk for myocardial infarction. In a previous linkage study of 11 families, evidence for tight linkage of subclass pattern B with the LDL receptor (LDLR) locus on chromosome 19p13.2 was obtained. To test whether a mutation in the structural portion of the LDLR gene could be responsible for the phenotype, we first sequenced the exons of the receptor binding domain for each pair of parents in these 11 pedigrees. For the remaining portion of the LDLR coding region, exons as well as cloned LDLR cDNAs were sequenced for selected members of the pedigrees. No mutations that changed the amino acid sequence of the LDLR were found. We conclude that it is unlikely that a mutant allele of the LDLR protein is responsible for ALP. C1 JACKSON LAB,BAR HARBOR,ME 04609. UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DONNER LAB,BERKELEY,CA 94720. LAWRENCE LIVERMORE NATL LAB,CTR HUMAN GENOME,LIVERMORE,CA. FU NHLBI NIH HHS [HL 07279, HL 18574] NR 26 TC 13 Z9 13 U1 0 U2 0 PU MUNKSGAARD INT PUBL LTD PI COPENHAGEN PA 35 NORRE SOGADE, PO BOX 2148, DK-1016 COPENHAGEN, DENMARK SN 0009-9163 J9 CLIN GENET JI Clin. Genet. PD APR PY 1997 VL 51 IS 4 BP 236 EP 240 PG 5 WC Genetics & Heredity SC Genetics & Heredity GA WZ890 UT WOS:A1997WZ89000004 PM 9184244 ER PT J AU Espey, C Dec, JE Litzinger, TA Santavicca, DA AF Espey, C Dec, JE Litzinger, TA Santavicca, DA TI Planar laser Rayleigh scattering for quantitative vapor-fuel imaging in a diesel jet SO COMBUSTION AND FLAME LA English DT Article ID LIGHT-SCATTERING; COMBUSTION; TEMPERATURE; DENSITY; ENGINE AB Quantitative images of vapor-phase fuel concentrations were obtained in an evaporating and combusting diesel jet using planar laser Rayleigh scattering. The diagnostic has been calibrated, evaluated, and successfully applied to an optically accessible direct-injection diesel engine for fired and nonfired operating conditions. The measurements were obtained in the leading portion of the diesel jet (the zone beyond 27 mm from the injector nozzle), where the fuel is entirely evaporated, and which corresponds to the main combustion zone in this engine. The technique was shown to be effective for quantitative imaging of the fuel-vapor concentration before ignition, with high spatial and temporal resolution. Additionally, images of the fuel-vapor concentration were further reduced to imagers of the equivalence ratio using an adiabatic mixing assumption to model the local temperature of the evaporating diesel jet. This procedure also yielded temperature distribution images. The results show that, at 4.5 degrees crank angle (0.63 ms) after the start of injection, which corresponds to the time just before the first indicated heat release, the fuel and air are relatively well mixed in the leading portion of the diesel jet. At this crank angle, the equivalence ratio in the majority of the jet ranges from 2 to 4. The edges of the jet are well defined, with the signal level rising sharply from the background level up to levels corresponding to equivalence ratios in the jet. The temperature of the richest mixture regions in the jet is as low as 700 K, with the ambient air temperature at 1000 K. Finally, comparisons of Rayleigh images of the reacting and nonreacting jet show that the initial breakdown of the fuel, indicated by a significant decrease in the Rayleigh signal intensity, occurs throughout the cross section of the leading portion of the diesel jet. (C) 1997 by The Combustion Institute. C1 SANDIA NATL LABS,LIVERMORE,CA 94551. PENN STATE UNIV,UNIVERSITY PK,PA 16802. NR 56 TC 60 Z9 64 U1 2 U2 13 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 1997 VL 109 IS 1-2 BP 65 EP 86 DI 10.1016/S0010-2180(96)00126-5 PG 26 WC Thermodynamics; Energy & Fuels; Engineering, Multidisciplinary; Engineering, Chemical; Engineering, Mechanical SC Thermodynamics; Energy & Fuels; Engineering GA WQ376 UT WOS:A1997WQ37600005 ER PT J AU Meisel, D AF Meisel, D TI Inorganic small colloidal particles SO CURRENT OPINION IN COLLOID & INTERFACE SCIENCE LA English DT Review ID LANGMUIR-BLODGETT-FILMS; CDSE QUANTUM DOTS; CADMIUM ARACHIDATE; POROUS SILICON; NANOCRYSTALLITES; TIO2; DYNAMICS AB The emphasis of study of small inorganic particles is shifting from the single particle to self-assembled aggregates of particles. Accordingly, the colligative properties of ensembles have also become a focus of interest. Advances in the synthesis and in the understanding of the physical properties of ensembles have led to the practical utilization of such networks and arrays, and this trend seems set to continue in the future. Molecular control over the process of particle self-assembly will allow the tailoring of the production of two- and three-dimensional arrays of nanoparticles for a variety of specific applications, probably in optical microelectronics and sensor technologies. RP Meisel, D (reprint author), ARGONNE NATL LAB,DIV CHEM,9700 S CASS AVE,ARGONNE,IL 60439, USA. NR 37 TC 8 Z9 8 U1 0 U2 12 PU CURRENT SCIENCE LTD PI LONDON PA 34-42 CLEVELAND STREET, LONDON, ENGLAND W1P 6LB SN 1359-0294 J9 CURR OPIN COLLOID IN JI Curr. Opin. Colloid Interface Sci. PD APR PY 1997 VL 2 IS 2 BP 188 EP 191 PG 4 WC Chemistry, Physical SC Chemistry GA WY187 UT WOS:A1997WY18700011 ER PT J AU Bishop, AR Roder, H AF Bishop, AR Roder, H TI Theory of colossal magnetoresistance SO CURRENT OPINION IN SOLID STATE & MATERIALS SCIENCE LA English DT Review ID DOUBLE-EXCHANGE; TRANSITION AB The history and recent developments in studying (colossal) magnetoresistance in perovskite manganese oxides show that there is growing evidence for strongly coupled spin, charge and lattice degrees of freedom. Together with disorder, these provide the microscopic driving forces for local and inhomogeneous textures. The modeling and experimental probes for localized charge-spin-lattice (polaron) structures, and their multiscale ordering, can be considered in terms of a growing synergy of solid state physics and materials science perspectives. RP Bishop, AR (reprint author), LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545, USA. NR 58 TC 25 Z9 25 U1 1 U2 16 PU CURRENT SCIENCE LTD PI LONDON PA 34-42 CLEVELAND STREET, LONDON, ENGLAND W1P 6LB SN 1359-0286 J9 CURR OPIN SOLID ST M JI Curr. Opin. Solid State Mat. Sci. PD APR PY 1997 VL 2 IS 2 BP 244 EP 251 DI 10.1016/S1359-0286(97)80073-3 PG 8 WC Materials Science, Multidisciplinary; Physics, Applied; Physics, Condensed Matter SC Materials Science; Physics GA WZ326 UT WOS:A1997WZ32600018 ER PT J AU Pickett, DA Murrell, MT AF Pickett, DA Murrell, MT TI Observations of Pa-231/U-235 disequilibrium in volcanic rocks SO EARTH AND PLANETARY SCIENCE LETTERS LA English DT Article DE uranium disequilibrium; protactinium; magmas; isotopes; basalts; island arcs ID RA-226 TH-230 DISEQUILIBRIUM; MIDOCEAN RIDGE BASALTS; EAST PACIFIC RISE; URANIUM-SERIES; RADIOACTIVE DISEQUILIBRIA; ISOTOPE EVIDENCE; ARC LAVAS; U-SERIES; U-238 TH-230-RA-226; MASS-SPECTROMETRY AB We present here the first survey of (P-231/U-235) ratios in volcanic rocks; such measurements are made possible by new mass spectrometric techniques. The data place new constraints on the timing and extent of magma source and evolutionary processes, particularly due to the sensitivity of the Pa-231-U-235 pair and its intermediate time scale (Pa-231 t(1/2) = 33 ky). (Pa-231/U-235) is found to vary widely, from 0.2 in carbonatites to 1.1-2.9 in basalts and 0.9-2.2 in arcs. Substantial Pa enrichment is nearly ubiquitous, suggestive of the relative incompatibility of Pa, qualitatively consistent with available partitioning data. The level of Pa-231-U-235 disequilibrium typically far exceeds that of Th-230-U-238 and is comparable to Ra-226-Th-230. The high (Pa-231/U-235) ratios in MORB and other basalts reflect a large degree of discrimination between two incompatible elements, posing challenges for modelling of melt generation and migration. Fundamental differences in (Pa-231/U-235) among different basaltic environments are likely related to contrasts in melting zone conditions (e.g., melting rate). Strong (Pa-231/U-235) disequilibria in continental basalts, for which (Th-230/U-238) disequilibria are small or absent, demonstrate that Pa-U fractionation is possible in both garnet and spinel mantle stability fields. In arcs, correlation of (Pa-231/U-235) and (Th-230/U-238) is consistent with U enrichment via slab-derived fluids, a process which is additional to the still dominant Pa enrichment. An important new constraint is provided by the observation that the near-equilibrium (Th-230/U-238) common to arcs and continental basalts is not typically accompanied by near-equilibrium (Pa-231/U-235), arguing against the influence of long magma history, crustal material, or equilibrium mantle sources in affecting decay-series ratios. Small sample sets from two silicic centers illustrate: (1) recent, rapid U enrichment in the magma chamber (El Chichon); and (2) the failure of substantial magma H2O-CO2 degassing to effect U-Th-Pa fractionation (Mono Craters). C1 LOS ALAMOS NATL LAB,ENVIRONM SCI & WASTE TECHNOL GRP CST7,LOS ALAMOS,NM 87545. NR 58 TC 63 Z9 63 U1 1 U2 6 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 1997 VL 148 IS 1-2 BP 259 EP 271 DI 10.1016/S0012-821X(97)00037-X PG 13 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA XC561 UT WOS:A1997XC56100018 ER PT J AU Edgington, DN Robbins, JA Colman, SM Orlandini, KA Gustin, MP Klump, JV Granina, LZ AF Edgington, DN Robbins, JA Colman, SM Orlandini, KA Gustin, MP Klump, JV Granina, LZ TI Comment on ''Uranium-series disequilibrium, sedimentation, diatom frustules, and paleoclimate change in Lake Baikal'' - Reply SO EARTH AND PLANETARY SCIENCE LETTERS LA English DT Editorial Material ID EQUILIBRIA; CARBON C1 NOAA, GREAT LAKES ENVIRONM RES LAB, ANN ARBOR, MI 48105 USA. US GEOL SURVEY, WOODS HOLE, MA 02543 USA. ARGONNE NATL LAB, DIV ENVIRONM RES, ARGONNE, IL 60439 USA. RUSSIAN ACAD SCI, INST LIMNOL, SIBERIAN DIV, IRKUTSK 664003, RUSSIA. RP UNIV WISCONSIN, CTR GREAT LAKES STUDIES, MILWAUKEE, WI 53204 USA. NR 17 TC 11 Z9 13 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0012-821X EI 1385-013X J9 EARTH PLANET SC LETT JI Earth Planet. Sci. Lett. PD APR PY 1997 VL 148 IS 1-2 BP 399 EP 404 DI 10.1016/S0012-821X(97)00033-2 PG 6 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA XC561 UT WOS:A1997XC56100030 ER PT J AU Slone, TH Orsak, LJ Malver, O AF Slone, TH Orsak, LJ Malver, O TI A comparison of price, rarity and cost of butterfly specimens: Implications for the insect trade and for habitat conservation SO ECOLOGICAL ECONOMICS LA English DT Article DE insect trade; conservation; sustainability; Papua New Guinea; butterflies ID EXTRACTIVE RESERVES; DENSITY-DEPENDENCE; WEST KALIMANTAN; FOREST; POPULATIONS; INDONESIA AB Insects can provide one source of income to villagers as part of an alternative to logging. The Insect Farming and Trading Agency (IFTA) of Papua New Guinea aims to return as much income as possible to village-level insect collectors. An increase in demand or profit margin in the insect trade could potentially benefit sustainable forestry schemes that include insect collecting. The sustainability of insect collecting is discussed. Species rarity, specimen prices, and species wing sizes are compared. Prices are greater for rarer species, Prices are correlated with wing size, particularly at the retail level, but rarity is not positively correlated with wing size. Consequently, it should be possible to selectively increase the prices of non-rare, larger species at the wholesale level. There is a large wholesale-to-retail price markup for some species. So, consumers are probably willing to pay a wide range of prices for some species, and therefore it may be possible for IFTA to raise prices for species when IFTA is the exclusive supplier and when there is an indication that there is low price elasticity. Although price increases may have a favorable impact on sustainable management of tropical forests, steady and long-term increased consumer demand for insects from tropical forests would likely have a more substantial impact. Income from extractive reserves is usually non-competitive with income from timber, hence a broad package of income sources is usually necessary. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV CELL & MOL BIOL,BERKELEY,CA 94720. CHRISTENSEN RES INST,MADANG,PAPUA N GUINEA. WINGS EARTH,OAKLAND,CA 94619. RP Slone, TH (reprint author), UNIV CALIF BERKELEY,DIV BIOCHEM & MOL BIOL,401 BARKER HALL,BERKELEY,CA 94720, USA. NR 36 TC 21 Z9 21 U1 2 U2 12 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-8009 J9 ECOL ECON JI Ecol. Econ. PD APR PY 1997 VL 21 IS 1 BP 77 EP 85 DI 10.1016/S0921-8009(96)00096-1 PG 9 WC Ecology; Economics; Environmental Sciences; Environmental Studies SC Environmental Sciences & Ecology; Business & Economics GA WV902 UT WOS:A1997WV90200006 ER PT J AU Theiss, SD AF Theiss, SD TI Could steel replace glass in flat panel displays? SO ELECTRONICS WORLD LA English DT Editorial Material C1 LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545. RP Theiss, SD (reprint author), PRINCETON UNIV,DEPT ELECT ENGN,PRINCETON,NJ 08544, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU REED BUSINESS PUBLISHING LTD PI SUTTON PA QUADRANT HOUSE THE QUADRANT, SUTTON, SURREY, ENGLAND SM2 5AS SN 0959-8332 J9 ELECTRON WORLD JI Electron. World PD APR PY 1997 VL 103 IS 1732 BP 274 EP 275 PG 2 WC Engineering, Electrical & Electronic; Telecommunications SC Engineering; Telecommunications GA WM286 UT WOS:A1997WM28600012 ER PT J AU Hirst, E Hadley, S Baxter, L AF Hirst, E Hadley, S Baxter, L TI Methods to estimate electric-utility transition costs SO ENERGY LA English DT Article AB Estimates of transition costs for U.S. investor-owned electric utilities range from $20 to $500 billion. These potential losses are a consequence of the above-market book values for some utility-owned power plants and long-term power-purchase contracts, as well as deferred income taxes, regulatory assets, and public-policy programs. Because of the wide range of estimates and the potentially large dollar amounts involved, state and federal regulators need a clear understanding of the methods used to calculate these estimates. In addition, they may want simple methods that they can use to check the reasonableness of the estimates that utilities and other parties present in regulatory proceedings. This paper explains various methods to calculate transition costs. Top-down methods, because they use the utility as the unit of analysis, are simple to apply and to understand. However, their aggregate nature makes it difficult to determine what specific assets and liabilities affect their estimates. Bottom-up methods use the individual asset (e.g. power plant) or liability (e.g. power-purchase contract) as the unit of analysis. These methods have substantial data and computational requirements. (C) 1997 Elsevier Science Ltd. All rights reserved. RP Hirst, E (reprint author), OAK RIDGE NATL LAB,DIV ENERGY,OAK RIDGE,TN 37831, USA. RI Hadley, Stanton/O-1465-2015 OI Hadley, Stanton/0000-0002-6514-8802 NR 8 TC 0 Z9 0 U1 0 U2 0 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 1997 VL 22 IS 4 BP 425 EP 435 DI 10.1016/S0360-5442(96)00120-X PG 11 WC Thermodynamics; Energy & Fuels SC Thermodynamics; Energy & Fuels GA WF048 UT WOS:A1997WF04800007 ER PT J AU Baxter, L Hirst, E Hadley, S AF Baxter, L Hirst, E Hadley, S TI Strategies to address transition costs in a restructuring electricity industry SO ENERGY POLICY LA English DT Article DE restructuring; transition costs; US electricity industry AB This paper discusses the potential financial consequences, or transition costs, of transforming electricity generation from a regulated to a competitive market in the US, Industry-wide estimates suggest potential monetary losses could exceed $100 billion as a result of the move to competition, The paper discusses the most prominent strategies suggested to address these potential losses. For each strategy, the paper identifies the parties most likely to bear the financial consequences. Most strategies do nothing to reduce the total costs to society, but instead shift costs from one set of economic actors to another. The exceptions are those strategies that result in economic-efficiency gains, which can then be used to offset the transition costs, Most of the strategies examined require the cooperation of several parties, including regulators, to be implemented successfully. (C) 1997 Published by Elsevier Science Ltd. RP Baxter, L (reprint author), OAK RIDGE NATL LAB,POB 2008,4500N,MS-6205,OAK RIDGE,TN 37831, USA. RI Hadley, Stanton/O-1465-2015 OI Hadley, Stanton/0000-0002-6514-8802 NR 28 TC 0 Z9 0 U1 0 U2 1 PU ELSEVIER SCI 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 1997 VL 25 IS 5 BP 481 EP 490 DI 10.1016/S0301-4215(97)00026-8 PG 10 WC Energy & Fuels; Environmental Sciences; Environmental Studies SC Energy & Fuels; Environmental Sciences & Ecology GA YA142 UT WOS:A1997YA14200002 ER PT J AU Dees, C Askari, M Garrett, S Gehrs, K Henley, D Ardies, CM AF Dees, C Askari, M Garrett, S Gehrs, K Henley, D Ardies, CM TI Estrogenic and DNA-damaging activity of Red No 3 in human breast cancer cells SO ENVIRONMENTAL HEALTH PERSPECTIVES LA English DT Article; Proceedings Paper CT Workshop on Hormones, Hormone Metabolism, Environment, and Breast Cancer CY SEP 28-29, 1995 CL NEW ORLEANS, LA DE xenoestrogen; red no 3; DDT; breast cancer; p53 ID PROTEIN-KINASE; P53; BINDING; PHOSPHORYLATION; ACTIVATION; RECEPTOR; CDK2 AB Exposure to pesticides, dyes, and pollutants that mimic the growth promoting effects of estrogen may cause breast cancer. The pesticide DDT and the food colorant Red No. 3 were found to increase the growth of HTB 133 but not estrogen receptor (ER) negative human breast cells (HTB 125) or rat liver epithelial cells (RLE). Red No. 3, beta-estradiol, and DDT increase ER site-specific DNA binding to the estrogen response element in HTB 133 cells and increase cyclin-dependent kinase 2 activity in MCF-7 breast cancer cells. Site-specific DNA binding by p53 in RLE, HTB 125, HTB 133, and MCF-7 cells was increased when they were treated with Red No. 3, which suggests that cellular DNA was damaged by this colorant. Red No. 3 increased binding of the ER from MCF-7 cells to the estrogen-responsive element. Consumption of Red No. 3, which has estrogenlike growth stimulatory properties and may be genotoxic, could be a significant risk factor in human breast carcinogenesis. C1 OAK RIDGE NATL LAB, HLTH SCI RES DIV, OAK RIDGE, TN USA. UNIV TENNESSEE, KNOXVILLE, TN USA. OAK RIDGE INST SCI EDUC, OAK RIDGE, TN USA. NE ILLINOIS UNIV, DEPT BIOL, CHICAGO, IL 60625 USA. NR 43 TC 9 Z9 10 U1 0 U2 0 PU US DEPT HEALTH HUMAN SCIENCES PUBLIC HEALTH SCIENCE PI RES TRIANGLE PK PA NATL INST HEALTH, NATL INST ENVIRONMENTAL HEALTH SCIENCES, PO BOX 12233, RES TRIANGLE PK, NC 27709-2233 USA SN 0091-6765 EI 1552-9924 J9 ENVIRON HEALTH PERSP JI Environ. Health Perspect. PD APR PY 1997 VL 105 SU 3 BP 625 EP 632 DI 10.2307/3433381 PG 8 WC Environmental Sciences; Public, Environmental & Occupational Health; Toxicology SC Environmental Sciences & Ecology; Public, Environmental & Occupational Health; Toxicology GA XB828 UT WOS:A1997XB82800013 ER PT J AU Dees, C Foster, JS Ahamed, S Wimalasena, J AF Dees, C Foster, JS Ahamed, S Wimalasena, J TI Dietary estrogens stimulate human breast cells to enter the cell cycle SO ENVIRONMENTAL HEALTH PERSPECTIVES LA English DT Article; Proceedings Paper CT Workshop on Hormones, Hormone Metabolism, Environment, and Breast Cancer CY SEP 28-29, 1995 CL NEW ORLEANS, LA DE antiestrogen; breast cancer; DDT; phytoestrogen; xenoestrogen ID CANCER; GENISTEIN; TUMOR; DDT AB It has been suggested that dietary estrogens neutralize the effect of synthetic chemicals that mimic the effects of estrogen (i.e., xenoestrogens, environmental estrogens). Genistein, a dietary estrogen, inhibits the growth of breast cancer cells at high doses but additional studies have suggested that al low doses, genistein stimulates proliferation of breast cancer cells. Therefore, if dietary estrogens are estrogenic at low doses, one would predict that they stimulate estrogen-receptor positive breast cancer cells to enter the cell cycle. Genistein and the fungal toxin zearalenone were found to increase the activity of cyclin dependent kinase 2 (Cdk2) and cyclin D-1 synthesis and stimulate the hyperphosphorylation of the retinoblastoma susceptibility gene product pRb105 in MCF-7 cells. The steroidal antiestrogen ICI 182,780 suppressed dietary estrogen-mediated activation of Cdk2. Dietary estrogens not only failed to suppress DDT-induced Cdk2 activity, but were found to slightly increase enzyme activity. Both zearalenone and genistein were found to stimulate the expression of a luciferase reporter gene under the control of an estrogen response element in MVLN cells. Our findings are consistent with a conclusion that dietary estrogens at low concentrations do not act as antiestrogens, but act like DDT and estradiol to stimulate human breast cancer cells to enter the cell cycle. C1 OAK RIDGE NATL LAB, HLTH SCI RES DIV, RISK ANAL SECT, OAK RIDGE, TN USA. UNIV TENN HOSP, DEPT OBSTET & GYNECOL, KNOXVILLE, TN USA. NR 25 TC 65 Z9 69 U1 0 U2 3 PU US DEPT HEALTH HUMAN SERVICES PUBLIC HEALTH SERVICE PI RES TRIANGLE PK PA NATL INST HEALTH, NATL INST ENVIRONMENTAL HEALTH SERVICES, PO BOX 12233, RES TRIANGLE PK, NC 27709-2233 SN 0091-6765 J9 ENVIRON HEALTH PERSP JI Environ. Health Perspect. PD APR PY 1997 VL 105 SU 3 BP 633 EP 636 DI 10.2307/3433382 PG 4 WC Environmental Sciences; Public, Environmental & Occupational Health; Toxicology SC Environmental Sciences & Ecology; Public, Environmental & Occupational Health; Toxicology GA XB828 UT WOS:A1997XB82800014 PM 9168007 ER PT J AU King, RB Bhattacharyya, NK Smith, HD Wiemers, KD AF King, RB Bhattacharyya, NK Smith, HD Wiemers, KD TI Noble metal-catalyzed ammonia generation by formic acid reduction of nitrate in simulated nuclear waste media SO ENVIRONMENTAL SCIENCE & TECHNOLOGY LA English DT Article ID FORMATE AB Simulants for the Hanford Waste Vitrification Plant(HWVP) feed containing the major non-radioactive components Al, Cd, Fe, Mn, Nd, Mi, Si, Zr, Na, CO32-, NO3-, and NO2- were used to study the formic acid reduction of nitrate and/or nitrite to ammonia at 90 degrees C catalyzed by the noble metals Ru, Rh, and/or Pd found as fission products in waste from the reprocessing of irradiated uranium. Reactions of this type were monitored using gas chromatography to analyze the CO2, H-2, NO, and N2O in the gas phase and a microammonia electrode to analyze the NH4+/NH3 in the liquid phase as a function of time. The rhodium-catalyzed reduction of nitrogen-oxygen compounds to ammonia by formic acid was found to exhibit the following features: (1) Nitrate rather than nitrite is the principal source of ammonia. (2) Ammonia production occurs at the expense of hydrogen production. (3) Supported rhodium metal catalysts are more active than rhodium in any other form, suggesting that ammonia production involves heterogeneous rather than homogeneous catalysis. C1 PACIFIC NW LAB, RICHLAND, WA 99352 USA. RP King, RB (reprint author), UNIV GEORGIA, DEPT CHEM, ATHENS, GA 30602 USA. NR 16 TC 12 Z9 12 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 1997 VL 31 IS 4 BP 984 EP 992 DI 10.1021/es960335+ PG 9 WC Engineering, Environmental; Environmental Sciences SC Engineering; Environmental Sciences & Ecology GA WR546 UT WOS:A1997WR54600031 ER PT J AU Cheng, IF Fernando, Q Korte, N AF Cheng, IF Fernando, Q Korte, N TI Electrochemical dechlorination of 4-chlorophenol to phenol SO ENVIRONMENTAL SCIENCE & TECHNOLOGY LA English DT Article ID POLYCHLORINATED-BIPHENYLS; REDUCTIVE DEHALOGENATION; RAPID DECHLORINATION; PALLADIUM; HYDROGENATION; CATALYSTS; SYSTEM; METAL; WATER AB We have hypothesized that hydrogen gas intercalated in a palladium lattice is the powerful reducing agent that reductively dechlorinates chlorinated organic compounds that are adsorbed on the surface of palladized electrodes. We have shown that dechlorination of 4-chlorophenol to phenol occurs rapidly on palladized carbon cloth or palladized graphite electrodes. The reactions on the palladized carbon cloth and graphite depend on the adsorption of the chlorinated organic compound on the carbon surface and the reaction with hydrogen at the palladium/carbon interface. Palladium was much more effective in promoting the dechlorination reaction than platinum, probably because of its ability to intercalate hydrogen in its lattice. C1 UNIV ARIZONA,DEPT CHEM,TUCSON,AZ 85721. OAK RIDGE NATL LAB,GRAND JUNCT OFF,DIV ENVIRONM SCI,GRAND JUNCTION,CO 81503. NR 16 TC 192 Z9 212 U1 13 U2 49 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 1997 VL 31 IS 4 BP 1074 EP 1078 DI 10.1021/es960602b PG 5 WC Engineering, Environmental; Environmental Sciences SC Engineering; Environmental Sciences & Ecology GA WR546 UT WOS:A1997WR54600044 ER PT J AU Vuilleumier, L Harley, RA Brown, NJ AF Vuilleumier, L Harley, RA Brown, NJ TI First- and second-order sensitivity analysis of a photochemically reactive system (a Green's function approach) SO ENVIRONMENTAL SCIENCE & TECHNOLOGY LA English DT Article ID VOLATILE ORGANIC-COMPOUNDS; CHEMICAL-KINETICS; AIR-QUALITY; MECHANISMS; UNCERTAINTIES AB Local sensitivity analysis of air quality models permits an estimation of the effects of parameter variations, can help assess uncertainties, and distinguishes important from unimportant model features. While local sensitivity analysis in atmospheric chemistry is usually conducted to the first-order, this work includes second-order sensitivity analysis. A Green's function method is used to compute the sensitivities of a photochemically reactive system. Time-dependent photolytic reaction rate coefficients are specified using two-parameter functions of time. The Green's function is used directly to study the temporal dependence of ozone concentrations on the NOx concentrations. ROG-limited (HOG/NOx = 6) and NOx-limited (HOG/NOx = 24) conditions are both evaluated. The importance of NO, formaldehyde, and aromatic chemistry is emphasized by the high ozone sensitivity to the initial concentrations of these species and to the reaction rate parameters of NO2 photolysis, NO recombination with ozone (NO + O-3 --> NO2 + O-2), formaldehyde photolysis (HCHO + hv --> 2HO(2) + CO), and NO2 + OH --> HNO3. The parameters that ozone concentration is most sensitive to were treated with second-order sensitivity analysis. A comparison of ozone concentration changes predicted by second-order sensitivity analysis with concentration changes computed directly shows that second-order sensitivity predictions are valid for parameter variations as large as +/-50% of the parameter's nominal value, whereas first-order predictions are valid for parameter variations of at most +/-25%. Even though all of the NOx in these simulations is introduced via initial concentrations, the Green's function reveals that the temporal pattern of NOx emission is likely to influence ozone concentrations. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV ENERGY & ENVIRONM,BERKELEY,CA 94720. UNIV CALIF BERKELEY,DEPT CIVIL & ENVIRONM ENGN,BERKELEY,CA 94720. RI Harley, Robert/C-9177-2016 OI Harley, Robert/0000-0002-0559-1917 NR 27 TC 27 Z9 27 U1 0 U2 4 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 1997 VL 31 IS 4 BP 1206 EP 1217 DI 10.1021/es960727g PG 12 WC Engineering, Environmental; Environmental Sciences SC Engineering; Environmental Sciences & Ecology GA WR546 UT WOS:A1997WR54600063 ER PT J AU AllenGil, SM Gubala, CP Landers, DH Lasorsa, BK Crecelius, EA Curtis, LR AF AllenGil, SM Gubala, CP Landers, DH Lasorsa, BK Crecelius, EA Curtis, LR TI Heavy metal accumulation in sediment and freshwater fish in US Arctic lakes SO ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY LA English DT Article DE arctic; fish; metals; sediment ID BEAR URSUS-MARITIMUS; NORTHWEST-TERRITORIES; ESSENTIAL ELEMENTS; TRACE-METALS; MERCURY; ALPINUS; SEALS; CHAR AB Metal concentrations in sediment and two species of freshwater fish (lake trout [Salvelinus namaycush], and grayling [Thymallus arcticus]) were examined in four Arctic lakes in Alaska. Concentrations of several metals were naturally high in the sediment relative to uncontaminated lakes in other Arctic regions and more temperate locations. For example, concentrations of Hg and Ni were 175 ng/g and 250 ng/g dry weight, respectively, in Feniak Lake surface sediment. If any anthropogenic enrichment has occurred, it is not distinguishable from background variability based on surface sediment to down core comparisons. With the exception of Hg, the site rank order of metal concentrations (Cu, Cd, Ni, Ph, and Zn) in sediment and freshwater fish tissue among lakes is not consistent. This suggests that a number of physical, chemical, and physiological parameters mediate metal bioavailability and uptake in these systems. Maximum concentrations of most metals in fish from this study are equal to or higher than those collected from remote Arctic lakes and rivers in Canada, Finland, and Russia. Muscle Hg concentrations in excess of 1 mu g/g wet weight were observed in lake trout from Feniak Lake, which has no identified Hg source other than naturally Hg-enriched sediments. Fish diet seems to influence some heavy metal burdens, as evidenced by the higher concentrations of some metals in lake trout compared to grayling, and differences among lakes for lake trout. Cadmium, Cu, and Zn burdens were higher in lakes where snails were consumed by trout compared to lakes without snails. C1 OREGON STATE UNIV,DEPT FISHERIES & WILDLIFE,CORVALLIS,OR 97331. UTAH STATE UNIV,DEPT CIVIL & ENVIRONM ENGN,INST NAT SYST ENGN,LOGAN,UT 84322. BATTELLE PACIFIC NW DIV,SEQUIM,WA 98382. E TENNESSEE STATE UNIV,COLL PUBL & ALLIED HLTH,DEPT ENVIRONM HLTH,JOHNSON CITY,TN 37614. RP AllenGil, SM (reprint author), US EPA,NATL HLTH & ENVIRONM EFFECTS RES LAB,200 SW 35TH ST,CORVALLIS,OR 97333, USA. NR 33 TC 38 Z9 40 U1 1 U2 22 PU SETAC PRESS PI PENSACOLA PA 1010 NORTH 12TH AVE, PENSACOLA, FL 32501-3370 SN 0730-7268 J9 ENVIRON TOXICOL CHEM JI Environ. Toxicol. Chem. PD APR PY 1997 VL 16 IS 4 BP 733 EP 741 DI 10.1897/1551-5028(1997)016<0733:HMAISA>2.3.CO;2 PG 9 WC Environmental Sciences; Toxicology SC Environmental Sciences & Ecology; Toxicology GA WU832 UT WOS:A1997WU83200018 ER PT J AU Goldsmith, R Brooks, BG AF Goldsmith, R Brooks, BG TI Toward a US National Radiation Dose Registry ... and more SO EUROPEAN JOURNAL OF CANCER LA English DT Article RP Goldsmith, R (reprint author), US DOE,OFF EPIDEMIOL & HLTH SURVEILLANCE,EPIDEMIOL STUDIES DIV,EH-42,WASHINGTON,DC 20585, USA. NR 1 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 0959-8049 J9 EUR J CANCER JI Eur. J. Cancer PD APR PY 1997 VL 33 SU 3 BP S22 EP S24 DI 10.1016/S0959-8049(97)00019-1 PG 3 WC Oncology SC Oncology GA XG148 UT WOS:A1997XG14800005 ER PT J AU Ueda, T Imaizumi, H Mizomoto, M Shepherd, IG AF Ueda, T Imaizumi, H Mizomoto, M Shepherd, IG TI Velocity statistics along the stagnation line of an axi-symmetric stagnating turbulent flow SO EXPERIMENTS IN FLUIDS LA English DT Article ID STREAMLINE TURBULENCE; IMPINGEMENT; FLAME; JET AB Velocity statistics along the stagnation line of an axi-symmetric wall stagnating turbulent flow are studied experimentally. A low turbulence, uniform air flow from a nozzle type air supply with an exit diameter of 50 mm stagnates at a wall located 50 mm downstream. A flow velocity is set to 3 m/s, 10 mm downstream from the exit of the air supply. Instantaneous values of streamwise and radial velocities are measured by laser-Doppler velocimetry. The turbulence level in the air flow is changed by use of turbulence generator. When the turbulence generator is not installed in the air supply, the mean velocity profile in the streamwise direction fits well with that of a laminar viscous flow with the rms value of velocity fluctuations low near the wall. With the turbulence generator installed, a significant turbulence structure appears near the wall. When the wall is approached, the rms value of velocity fluctuations in the streamwise direction decreases monotonically while the profile of the rms value in the radial direction reaches a maximum near the wall. The increase in the rms value of velocity fluctuations in the radial direction near the wall is attributed to the bi-modal histogram of the fluctuating velocity in the radial direction. Near the wall, the instantaneous stagnation streamline fluctuates and the probability of the mean location of the stagnation point reaches a maximum not at the stagnation line but on a circle around the stagnation line, resulting in the bi-modal histogram. Turbulence statistics, the rms value of velocity fluctuation and the turbulent kinetic energy, can be normalized successfully by similarity parameters based on the strain rate and the reference turbulent kinetic energy introduced by Champion and Libby. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV ENERGY & ENVIRONM,COMBUST GRP,BERKELEY,CA 94720. RP Ueda, T (reprint author), KEIO UNIV,DEPT MECH ENGN,KOHOKU KU,3-14-1 HIYOSHI,YOKOHAMA,KANAGAWA 223,JAPAN. NR 21 TC 6 Z9 6 U1 0 U2 1 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 SN 0723-4864 J9 EXP FLUIDS JI Exp. Fluids PD APR PY 1997 VL 22 IS 6 BP 473 EP 481 DI 10.1007/s003480050074 PG 9 WC Engineering, Mechanical; Mechanics SC Engineering; Mechanics GA WZ127 UT WOS:A1997WZ12700004 ER PT J AU Burakovsky, L Horwitz, LP AF Burakovsky, L Horwitz, LP TI Gell-Mann-Okubo mass formula for SU(4) meson hexadecuplet SO FOUNDATIONS OF PHYSICS LETTERS LA English DT Article DE hadronic resonance spectrum; quark model; flavor symmetry; Gell-Mann-Okubo ID FERMION MASSES; SO(10) AB Using the linear mass spectrum of an SU(4) meson hexadecuplet, we derive the Gell-Mann-Okubo mass formula for the charmed mesons, in good agreement with experiment. The possible generalization of this method to a higher symmetry group is briefly discussed. C1 INST ADV STUDY,SCH NAT SCI,PRINCETON,NJ 08540. BAR ILAN UNIV,DEPT PHYS,IL-52100 RAMAT GAN,ISRAEL. RP Burakovsky, L (reprint author), LOS ALAMOS NATL LAB,DIV THEORET,T-8,LOS ALAMOS,NM 87545, USA. NR 34 TC 5 Z9 5 U1 1 U2 1 PU PLENUM PUBL CORP PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 SN 0894-9875 J9 FOUND PHYS LETT JI Found. Phys. Lett. PD APR PY 1997 VL 10 IS 2 BP 131 EP 141 DI 10.1007/BF02764235 PG 11 WC Physics, Multidisciplinary SC Physics GA XF052 UT WOS:A1997XF05200004 ER PT J AU Williams, MD AF Williams, MD TI D-T operation on TFTR SO FUSION ENGINEERING AND DESIGN LA English DT Article; Proceedings Paper CT 19th Symposium on Fusion Technology (SOFT-19) CY SEP 16-20, 1996 CL LISBON, PORTUGAL AB The Tokamak Fusion Test Reactor (TFTR) has operated safely and routinely with tritium fuel since November 1993. Experiments conducted during this time have demonstrated improved plasma confinement properties, the first measurements of alpha heating and transport and the ICRF heating and current drive of D-T plasmas. Reactor level fusion power densities up to 2.8 MW m(-3) have been attained as well as more than 10 MW of fusion power and 6.5 MJ of fusion energy per pulse. In support of these accomplishments, the TFTR equipment has met or exceeded the original design values. The toroidal magnetic field has been upgraded from 5.2 to 6.0 Tesla (on-axis), the neutral beams have injected up to 40 MW with a combination of deuterium and tritium fueling and the ICRF systems have been operated at various frequencies, from 30 to 64 MHz, to support an assortment of fast wave experiments. From November 1993 through July 1996, there have been 19 725 plasma shots. These include 841 deuterium-tritium pulses which have produced a total of 4.8 x 10(20) D-T neutrons and 1.4 CJ of fusion energy. More than 864 kCi (almost 90 g) of tritium have been processed through the TFTR facility while constrained to a site limit ('in-process') of 50 kCi. A low tritium inventory cryogenic distillation system has been recently installed and tested to provide on-site repurification of the plasma exhaust. Maintenance and repair activities have become routine in this facility. Hundreds of calibrations, repairs and installations requiring work on tritium contaminated and activated systems have been performed. Utilizing As Low As Reasonably Achievable (ALARA) principles, the radiation exposure to workers has been comparable to that experienced during the previous deuterium-only operating phase. The total annual site boundary dose, due to all pathways (prompt neutron radiation, activated air and controlled tritium release), has been less than 3 mu Sv, or 3% of the design limit of 100 mu Sv and 0.3% of the regulatory limit of 1 mSv. (C) 1997 Elsevier Science S.A. RP Williams, MD (reprint author), PRINCETON UNIV,PLASMA PHYS LAB,POB 451,PRINCETON,NJ 08543, USA. NR 19 TC 3 Z9 3 U1 1 U2 4 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0920-3796 J9 FUSION ENG DES JI Fusion Eng. Des. PD APR PY 1997 VL 36 IS 1 BP 135 EP 142 DI 10.1016/S0920-3796(97)00018-5 PG 8 WC Nuclear Science & Technology SC Nuclear Science & Technology GA XN657 UT WOS:A1997XN65700013 ER PT J AU Dongarra, JJ Meuer, HW Simon, HD Strohmaier, E AF Dongarra, JJ Meuer, HW Simon, HD Strohmaier, E TI Changing technologies of HPC SO FUTURE GENERATION COMPUTER SYSTEMS LA English DT Article DE high performance computing; HPC technology; supercomputer market; supercomputer technology AB In 1993 for the first time a list of the top 500 supercomputer sites world-wide was made available. The Top500 list allows a much more detailed and well-founded analysis of the state of high performance computing. Previously data such as the number and geographical distribution of supercomputer installations were difficult to obtain, and only a few analysts undertook the effort to track the press releases by dozens of vendors. With the Top500 report now generally and easily available it is possible to present an analysis of the state of High Performance Computing (HPC). This paper summarizes some of the most important observations about HPC as of late 1996, in particular the continued dominance of the world market in HPC by the US, the market penetration by commodity microprocessor based systems, and the growing industrial use of super-computers. C1 OAK RIDGE NATL LAB,MATH SCI SECT,OAK RIDGE,TN 37831. UNIV MANNHEIM,CTR COMP,D-68131 MANNHEIM,GERMANY. UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,NERSC,BERKELEY,CA 94720. RP Dongarra, JJ (reprint author), UNIV TENNESSEE,DEPT COMP SCI,KNOXVILLE,TN 37996, USA. NR 13 TC 1 Z9 1 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0167-739X J9 FUTURE GENER COMP SY JI Futur. Gener. Comp. Syst. PD APR PY 1997 VL 12 IS 5 BP 461 EP 474 DI 10.1016/S0167-739X(96)00031-3 PG 14 WC Computer Science, Theory & Methods SC Computer Science GA XA990 UT WOS:A1997XA99000012 ER PT J AU Lam, NP Neumann, AU Gretch, DR Wiley, TE Falkenholm, J Perelson, AS Layden, TJ AF Lam, NP Neumann, AU Gretch, DR Wiley, TE Falkenholm, J Perelson, AS Layden, TJ TI Genotype 1A and 1B infected patients (Pt) require high initial daily interferon (IFN) doses. SO GASTROENTEROLOGY LA English DT Meeting Abstract C1 UNIV ILLINOIS, DEPT PHARM PRACTICE, CHICAGO, IL USA. UNIV ILLINOIS, DEPT MED, CHICAGO, IL USA. BAR ILAN UNIV, DEPT LIFE SCI, IL-52100 RAMAT GAN, ISRAEL. UNIV WASHINGTON, HEPATATIS LAB, SEATTLE, WA 98195 USA. LOS ALAMOS NATL LAB, DIV THEORET, LOS ALAMOS, NM USA. NR 0 TC 2 Z9 2 U1 0 U2 0 PU W B SAUNDERS CO-ELSEVIER INC PI PHILADELPHIA PA 1600 JOHN F KENNEDY BOULEVARD, STE 1800, PHILADELPHIA, PA 19103-2899 USA SN 0016-5085 J9 GASTROENTEROLOGY JI Gastroenterology PD APR PY 1997 VL 112 IS 4 SU S BP A1312 EP A1312 PG 1 WC Gastroenterology & Hepatology SC Gastroenterology & Hepatology GA WV419 UT WOS:A1997WV41905231 ER PT J AU Lam, NP Neumann, AU Gretch, DR Wiley, TE Perelson, AS Layden, TJ AF Lam, NP Neumann, AU Gretch, DR Wiley, TE Perelson, AS Layden, TJ TI Rapid I-ICV clearance with high induction interferon (IFN) doses is important for sustained response. SO GASTROENTEROLOGY LA English DT Meeting Abstract C1 UNIV ILLINOIS, DEPT MED, CHICAGO, IL USA. UNIV ILLINOIS, DEPT PHARM PRACTICE, CHICAGO, IL USA. BAR ILAN UNIV, IL-52100 RAMAT GAN, ISRAEL. UNIV WASHINGTON, SEATTLE, WA 98195 USA. LOS ALAMOS NATL LAB, LOS ALAMOS, NM USA. NR 0 TC 2 Z9 2 U1 0 U2 0 PU W B SAUNDERS CO-ELSEVIER INC PI PHILADELPHIA PA 1600 JOHN F KENNEDY BOULEVARD, STE 1800, PHILADELPHIA, PA 19103-2899 USA SN 0016-5085 J9 GASTROENTEROLOGY JI Gastroenterology PD APR PY 1997 VL 112 IS 4 SU S BP A1312 EP A1312 PG 1 WC Gastroenterology & Hepatology SC Gastroenterology & Hepatology GA WV419 UT WOS:A1997WV41905230 ER PT J AU Xu, YZ Xie, DT Soloway, RD Ferraro, JR Xu, JP Weng, SF Wang, XZ Chen, ZD Ren, JQ Xu, DF Wu, JG Xu, GX AF Xu, YZ Xie, DT Soloway, RD Ferraro, JR Xu, JP Weng, SF Wang, XZ Chen, ZD Ren, JQ Xu, DF Wu, JG Xu, GX TI Use of the vibrational spectrum for cholesterol at -150 degrees C to confirm the atomic assignment based on a MM3 molecular modeling program. SO GASTROENTEROLOGY LA English DT Meeting Abstract C1 BEIJING UNIV, DEPT CHEM, BEIJING 100871, PEOPLES R CHINA. UNIV TEXAS, MED BRANCH, DIV GASTROENTEROL, GALVESTON, TX 77550 USA. ARGONNE NATL LAB, ARGONNE, IL 60439 USA. N CAROLINA STATE UNIV, DEPT CHEM, RALEIGH, NC 27695 USA. NR 0 TC 3 Z9 3 U1 0 U2 0 PU W B SAUNDERS CO-ELSEVIER INC PI PHILADELPHIA PA 1600 JOHN F KENNEDY BOULEVARD, STE 1800, PHILADELPHIA, PA 19103-2899 USA SN 0016-5085 J9 GASTROENTEROLOGY JI Gastroenterology PD APR PY 1997 VL 112 IS 4 SU S BP A1418 EP A1418 PG 1 WC Gastroenterology & Hepatology SC Gastroenterology & Hepatology GA WV419 UT WOS:A1997WV41905651 ER PT J AU Yu, YZ Soloway, RD Xu, JP Ferraro, JR Tian, W Ren, JQ Xu, ZH Xiu, DF Wu, JG Xu, GX AF Yu, YZ Soloway, RD Xu, JP Ferraro, JR Tian, W Ren, JQ Xu, ZH Xiu, DF Wu, JG Xu, GX TI Characterization of hydrogen bonding between bile acid molecules using low temperature Fourier transform infrared (FT-IR) spectroscopy. SO GASTROENTEROLOGY LA English DT Meeting Abstract C1 BEIJING UNIV, DEPT CHEM, BEIJING 100871, PEOPLES R CHINA. UNIV TEXAS, MED BRANCH, DIV GASTROENTEROL, GALVESTON, TX 77550 USA. ARGONNE NATL LAB, ARGONNE, IL 60439 USA. N CAROLINA STATE UNIV, DEPT CHEM, RALEIGH, NC 27695 USA. NR 0 TC 0 Z9 0 U1 0 U2 1 PU W B SAUNDERS CO-ELSEVIER INC PI PHILADELPHIA PA 1600 JOHN F KENNEDY BOULEVARD, STE 1800, PHILADELPHIA, PA 19103-2899 USA SN 0016-5085 J9 GASTROENTEROLOGY JI Gastroenterology PD APR PY 1997 VL 112 IS 4 SU S BP A1422 EP A1422 PG 1 WC Gastroenterology & Hepatology SC Gastroenterology & Hepatology GA WV419 UT WOS:A1997WV41905667 ER PT J AU Yu, W Andersson, B Worley, KC Muzny, DM Ding, Y Liu, W Ricafrente, JY Wentland, MA Lennon, G Gibbs, RA AF Yu, W Andersson, B Worley, KC Muzny, DM Ding, Y Liu, W Ricafrente, JY Wentland, MA Lennon, G Gibbs, RA TI Large-scale concatenation cDNA sequencing SO GENOME RESEARCH LA English DT Letter ID MESSENGER-RNA; IDENTIFICATION; SEARCH; GENES AB A total of 100 kb of DNA derived from 69 individual human brain cDNA clones of 0.7-2.0 kb were sequenced by concatenated cDNA sequencing (CCS), whereby multiple individual DNA fragments are sequenced simultaneously in a single shotgun library. The method yielded accurate sequences and a similar efficiency compared with other shotgun libraries constructed from single DNA fragments (>20 kb). Computer analyses were carried out on 65 cDNA clone sequences and their corresponding end sequences to examine both nucleic acid and amino acid sequence similarities in the databases. Thirty-seven clones revealed no DNA database matches, 12 clones generated exact matches (greater than or equal to 98% identity), and 16 clones generated nonexact matches (57%-97% identity) to either known human or other species genes. Of those 28 matched clones, 8 had corresponding end sequences that failed to identify similarities. In a protein similarity search, 27 clone sequences displayed significant matches, whereas only 20 of the end sequences had matches to known protein sequences. Our data indicate that full-length cDNA insert sequences provide significantly more nucleic acid and protein sequence similarity matches than expressed sequence tags (ESTs) for database searching. C1 BAYLOR COLL MED,DEPT MOL & HUMAN GENET,HOUSTON,TX 77030. LAWRENCE LIVERMORE NATL LAB,CTR HUMAN GENOME,LIVERMORE,CA 94550. RI Andersson, Bjorn/G-9832-2013 OI Andersson, Bjorn/0000-0002-4624-0259 FU NHGRI NIH HHS [1F32 HG00169-01, U54 HG003273, P30 HG00210-05, R01 HG00823, F33 HG000210, F32 HG000169] NR 14 TC 41 Z9 77 U1 0 U2 1 PU COLD SPRING HARBOR LAB PRESS PI PLAINVIEW PA 1 BUNGTOWN RD, PLAINVIEW, NY 11724 SN 1054-9803 J9 GENOME RES JI Genome Res. PD APR PY 1997 VL 7 IS 4 BP 353 EP 358 PG 6 WC Biochemistry & Molecular Biology; Biotechnology & Applied Microbiology; Genetics & Heredity SC Biochemistry & Molecular Biology; Biotechnology & Applied Microbiology; Genetics & Heredity GA WT026 UT WOS:A1997WT02600006 PM 9110174 ER PT J AU PerezCastro, AV Wilson, J Altherr, MR AF PerezCastro, AV Wilson, J Altherr, MR TI Genomic organization of the human fibroblast growth factor receptor 3 (FGFR3) gene and comparative sequence analysis with the mouse fgfr3 gene SO GENOMICS LA English DT Article ID HUNTINGTON DISEASE GENE; MUTATIONS; FAMILY; ACHONDROPLASIA; REGION; MEMBER; DOMAIN; FORM; RNA; DNA AB Fibroblast growth factor receptor 3 (FGFR3) is a developmentally regulated transmembrane protein. Three other FGFRs (1, 2, and 4) in conjunction with FGFR3 are part of the receptor tyrosine kinase superfamily, Mutations in three of these genes (FGFR1, 2, and 3) have been determined to be the cause of human growth and developmental disorders. We have characterized a 22-kb DNA fragment containing the human FGFR3 gene and determined 11 kb of its nucleotide sequence. The gene consists of 19 exons and 18 introns spanning 16.5 kb, and the boundaries between exons and introns follow the GT/AG rule,The translation initiation and termination sites are located in exon 2 and exon 19, respectively. The sequence of the 5'-flanking region (1.5 kb) lacks the typical TATA or CAAT boxes, However, several putative binding sites for transcription factors SP1, AP2, Krox 24, IgHC.4, and Zeste are present. The 0.77-kb region from position -889 (5'-flanking region) to -119 (intron 1) contains a CpG island. A comparative sequence analysis of the human and mouse FGFR3 genes indicates that the overall genomic structure and organization of the human gene are nearly identical to those of its mouse counterpart. Furthermore, there is a striking similarity in the promoter-regions of both genes, and several of the putative transcription factor-binding sites are conserved across species, suggesting a definitive role of these factors in the transcriptional regulation of these genes. (C) 1997 Academic Press. C1 LOS ALAMOS NATL LAB,DIV LIFE SCI,GEN GRP,LOS ALAMOS,NM 87545. NR 29 TC 57 Z9 59 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 0888-7543 J9 GENOMICS JI Genomics PD APR 1 PY 1997 VL 41 IS 1 BP 10 EP 16 DI 10.1006/geno.1997.4616 PG 7 WC Biotechnology & Applied Microbiology; Genetics & Heredity SC Biotechnology & Applied Microbiology; Genetics & Heredity GA WR729 UT WOS:A1997WR72900002 PM 9126476 ER PT J AU Chiarello, RP Sturchio, NC Grace, JD Geissbuhler, P Sorensen, LB Cheng, LW Xu, ST AF Chiarello, RP Sturchio, NC Grace, JD Geissbuhler, P Sorensen, LB Cheng, LW Xu, ST TI Otavite-calcite solid-solution formation at the calcite-water interface studied in situ by synchrotron X-ray scattering SO GEOCHIMICA ET COSMOCHIMICA ACTA LA English DT Article ID FORCE MICROSCOPY; IN-SITU; SORPTION; SURFACE; CARBONATE; GROWTH; DISSOLUTION; CADMIUM; SYSTEM; CD-2+ AB Synchrotron X-ray scattering measurements were performed in situ during the formation of thin (50-600 Angstrom) overgrowths of otavite-calcite solid-solutions at the (<10(1)over bar 4>) cleavage surface of single- crystal calcite. These solid-solutions were precipitated from EDTA-bearing aqueous solutions having varied initial saturation states of otavite and calcite. From repetitive X-ray diffraction scans, the Cd/(Ca + Cd) ratios and the effective thicknesses (average domain size perpendicular to the calcite cleavage surface) of the solid-solutions were determined as a function of time. Additional in-plane X-ray diffraction scans were done to further characterize the relationship between the solid-solutions and the calcite cleavage surface. The solid-solution phase grew epitaxially with a(<10(1)over bar 4>) growth plane oriented parallel to the calcite (<10(1)over bar 4>) cleavage surface, The compositions of the solid-solutions evolved with time, while their growth rates (increases in effective thickness) remained fairly constant (10-54 Angstrom/hr). In each experiment, the coverage of the initial surface by the solid-solution (calculated from the difference between the initial and final Cd concentrations in the aqueous solution) was about 20%. Glancing-incidence X-ray reflectivity scans were also monitored as a function of time. From these scans, we determined that the solid-water interface did not become significantly rougher during the nucleation and growth of the solid-solution phase, These observations indicate that the solid-solution grew by layer spreading and that most growth may have occurred preferentially at macrostep faces produced during cleavage. Copyright (C) 1997 Elsevier Science Ltd. C1 WESTERN MICHIGAN UNIV,DEPT GEOL,KALAMAZOO,MI 49008. UNIV WASHINGTON,DEPT PHYS,SEATTLE,WA 98195. NORTHWESTERN UNIV,DEPT MAT SCI & ENGN,EVANSTON,IL 60208. ARGONNE NATL LAB,DIV CHEM TECHNOL,ARGONNE,IL 60439. RP Chiarello, RP (reprint author), ARGONNE NATL LAB,DIV ENVIRONM RES,ARGONNE,IL 60439, USA. RI Cheng, Likwan/C-1436-2013 NR 30 TC 45 Z9 46 U1 0 U2 11 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0016-7037 J9 GEOCHIM COSMOCHIM AC JI Geochim. Cosmochim. Acta PD APR PY 1997 VL 61 IS 7 BP 1467 EP 1474 DI 10.1016/S0016-7037(97)00010-0 PG 8 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA WV631 UT WOS:A1997WV63100008 ER PT J AU Simpson, K AF Simpson, K TI Energy R&D: Investing in the future SO GEOTIMES LA English DT Article RP Simpson, K (reprint author), US DOE,ENERGY PROGRAMS,WASHINGTON,DC 20585, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER GEOLOGICAL INST PI ALEXANDRIA PA 4220 KING ST, ALEXANDRIA, VA 22302-1507 SN 0016-8556 J9 GEOTIMES JI Geotimes PD APR PY 1997 VL 42 IS 4 BP 26 EP 28 PG 3 WC Geosciences, Multidisciplinary SC Geology GA WR555 UT WOS:A1997WR55500023 ER PT J AU Hebeisen, T Luscher, A Zanetti, S Fischer, BU Hartwig, UA Frehner, M Hendrey, GR Blum, H Nosberger, J AF Hebeisen, T Luscher, A Zanetti, S Fischer, BU Hartwig, UA Frehner, M Hendrey, GR Blum, H Nosberger, J TI Growth response of Trifolium repens L and Lolium perenne L as monocultures and bi-species mixture to free air CO2 enrichment and management SO GLOBAL CHANGE BIOLOGY LA English DT Article DE competition; elevated CO2; FACE; L-perenne; root mass; T-repens; yield ID CARBON-DIOXIDE CONCENTRATION; ELEVATED CO2; WHITE CLOVER; ATMOSPHERIC CO2; NITROGEN-FERTILIZER; MINERAL-NUTRITION; TALLGRASS PRAIRIE; ROOT-GROWTH; RYEGRASS; GRASS AB Trifolium repens L. and Lolium perenne L. were grown in monocultures and bi-species mixture in a Free Air Carbon Dioxide Enrichment (FACE) experiment at elevated (60 Pa) and ambient (35 Pa) CO2 partial pressure (pCO(2)) for three years. The effects of defoliation frequencies (4 and 7 cuts in 1993; 4 and 8 cuts in 1994/95) and nitrogen fertilization (10 and 42 g m(-2) y(-1) N in 1993; 14 and 56 g m(-2) y(-1) in 1994/95) on the growth response to pCO(2) were investigated. There were significant interspecific differences in the CO2 responses during the first two years, while in the third growing season, these interspecific differences disappeared. Yield of T. repens in monocultures increased in the first two years by 20% when grown at elevated pCO(2). This CO2 response was independent of defoliation frequency and nitrogen fertilization. In the third year, the CO2 response of T. repens declined to 11%. In contrast, yield of L. perenne monocultures increased by only 7% on average over three years at elevated pCO(2). The yield response of L. perenne to CO2 changed according to defoliation frequency and nitrogen fertilization, mainly in the second and third year. The ratio of root/yield of L. perenne increased under elevated pCO(2), low N fertilizer rate, and frequent defoliation, but it remained unchanged in T. repens. We suggest that the more abundant root growth of L. perenne was related to increased N limitation under elevated pCO(2). The consequence of these interspecific differences in the CO2 response was a higher proportion of T. repens in the mixed swards at elevated pCO(2). This was evident in all combinations of defoliation and nitrogen treatments. However, the proportion of the species was more strongly affected by N fertilization and defoliation frequency than by elevated pCO(2). Based on these results, we conclude that the species proportion in managed grassland may change as the CO2 concentration increases. However, an adapted management could, at least partially, counteract such CO2 induced changes in the proportion of the species. Since the availability of mineral N in the soil may be important for the species' responses to elevated pCO(2), more long-term studies, particularly of processes in the soil, are required to predict the entire ecosystem response. C1 ETH ZURICH,INST PLANT SCI,CH-8092 ZURICH,SWITZERLAND. BROOKHAVEN NATL LAB,DEPT APPL SCI,LONG ISL CITY,NY 11973. NR 44 TC 183 Z9 200 U1 6 U2 41 PU BLACKWELL SCIENCE LTD PI OXFORD PA P O BOX 88, OSNEY MEAD, OXFORD, OXON, ENGLAND OX2 0NE SN 1354-1013 J9 GLOB CHANGE BIOL JI Glob. Change Biol. PD APR PY 1997 VL 3 IS 2 BP 149 EP 160 DI 10.1046/j.1365-2486.1997.00073.x PG 12 WC Biodiversity Conservation; Ecology; Environmental Sciences SC Biodiversity & Conservation; Environmental Sciences & Ecology GA WU786 UT WOS:A1997WU78600007 ER PT J AU Goans, RE Holloway, EC Berger, ME Ricks, RC AF Goans, RE Holloway, EC Berger, ME Ricks, RC TI Early dose assessment following severe radiation accidents SO HEALTH PHYSICS LA English DT Article DE accident analysis; gamma radiation; health effects; dosimetry ID WHOLE-BODY IRRADIATION; EXPOSURE; MODEL AB Early treatment of victims of high level acute whole-body x-ray or gamma exposure has been shown to improve their likelihood of survival, However, in such cases, both the magnitude of the exposure and the dosimetry profile(s) of the victim(s) are often not known in detail for days to weeks. A simple dose-prediction algorithm based on lymphocyte kinetics as documented in prior radiation accidents is presented here, This algorithm provides an estimate of dose within the first 8 h following an acute whole-body exposure, Early lymphocyte depletion kinetics after a severe radiation accident follow a single exponential, L(t) = L(o)e(-k(D)t), where k(D) is a rate constant, dependent primarily on the average dose, D, Within the first 8 h post-accident, K(D) may be calculated utilizing serial lymphocyte counts. Data from the REAC/TS Radiation Accident Registry were used to develop a dose-prediction algorithm from 43 gamma exposure cases where both lymphocyte kinetics and dose reconstruction were felt to be reasonably reliable, The inverse relationship D(K) may be modeled by a simple two parameter curve of the form D = a/(1 + b/K) in the range 0 less than or equal to D less than or equal to 15 Gy, with fitting parameters (mean +/- SD): a = 13.6 +/- 1.7 Gy, and b = 1.0 +/- 0.20 d(-1). Dose estimated in this manner is intended to serve only as a first approximation to guide initial medical management. C1 OAK RIDGE INST SCH & EDUC, REACTS, OAK RIDGE, TN 37831 USA. NR 31 TC 63 Z9 67 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 1997 VL 72 IS 4 BP 513 EP 518 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 WN590 UT WOS:A1997WN59000002 PM 9119674 ER PT J AU Mao, XS Kase, KR Liu, JC Nelson, WR Kleck, JH Johnsen, S AF Mao, XS Kase, KR Liu, JC Nelson, WR Kleck, JH Johnsen, S TI Neutron sources in the Varian Clinac 2100C/2300C medical accelerator calculated by the EGS4 code SO HEALTH PHYSICS LA English DT Article DE medical radiation; computer calculations; Monte Carlo; neutrons AB The photoneutron yields produced in different components of the medical accelerator heads evaluated in these studies (24-MV Clinac 2500 and a Clinac 2100C/2300C running in the 10-MV, I5-MV, 18-MV and 20-MV modes) were calculated by the EGS4 Monte Carlo code using a modified version of the Combinatorial Geometry of MORSE-CG. Actual component dimensions and materials (i.e., targets, collimators, flattening filters, jaws and shielding for specific accelerator heads) were used in the geometric simulations, Calculated relative neutron yields in different components of a 24-MV Clinac 2500 were compared with the published measured data, and were found to agree to within +/-30%. Total neutron yields produced in the Clinac 2100/2300, as a function of primary electron energy and field size, are presented, A simplified Clinac 2100/2300C geometry is presented to calculate neutron yields, which were compared with those calculated by using the fully-described geometry. C1 VARIAN ASSOCIATES INC, PALO ALTO, CA 94304 USA. STANFORD UNIV, STANFORD LINEAR ACCELERATOR CTR, STANFORD, CA 94309 USA. NR 10 TC 56 Z9 56 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 1997 VL 72 IS 4 BP 524 EP 529 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 WN590 UT WOS:A1997WN59000004 PM 9119676 ER PT J AU Jones, TD Morris, MD Young, RW Kehlet, RA AF Jones, TD Morris, MD Young, RW Kehlet, RA TI Neutron RBEs for cytopenia and repopulation of stroma and hematopoietic stem cells: Mathematical models of marrow cell kinetics SO HEALTH PHYSICS LA English DT Article DE kinetics; relative biological effectiveness; neutrons; gamma rays ID RADIATION-INDUCED MYELOPOIESIS; CARCINOGENIC RISK ASSESSMENTS; DIFFERENT-ENERGY NEUTRONS; UNIFYING CONCEPT; X-RAYS; MICE; MOUSE; IRRADIATIONS; PHOTONS; DEATH AB The objectives of this study were to (a) extend previous bone-marrow cell kinetics models that have been published for ionizing photons to include neutron radiations, and (b) provide Relative Biological Effectiveness (RBE) values for time-specific cell killing (cytopenia) and compensatory cellular proliferation (repopulation in response to toxic injury) for neutron doses ranging from 0.01 to 4.5 Gy delivered uniformly over one minute, hour, day, week, and month. RBEs for cytopenia of a cell lineage were based on ratios of protocol-specific doses that determined the same cell population nadir, whereas the RBEs for repopulation of a lineage were based on the ratios of protocol-specific doses that corresponded to the same total number of cells killed over the radiation treatments, and which should be replaced for long-term survival of the animal. Time-dependent RBEs were computed for neutron exposures relative to the effect of Co-60 gamma rays given as a prompt dose. By the use of these RBE factors, low or variable dose rates, dose fractionations given over long periods of time, and different protocols involving several radiation qualities can be converted realistically, and by standard convention, into an equivalent nose of a reference radiation comprised of x or gamma rays given either as a pulse or at any other reference dose rate for which risk information based on epidemiological or animal dose-response data are available. For stromal tissues irradiated by fission neutrons, time-dependent RBEs for cytopenia were computed to range from 4.24 to 0.70 and RBEs for repopulation varied from a high of 6.88 to a low of 2.24. For hematopoietic stem cells irradiated by fission neutrons, time-dependent RBEs for cytopenia were computed to range from 5.02 to 0.22 and RBEs for repopulation varied from a high of 5.02 to a low of 1.98. RBEs based on tissue-kerma-free-in-air would be about twofold lower for isotropic cloud or rotational exposure geometries because marrow dose from isotropic neutron fields suffer factor-of-two greater attenuation than the gamma doses from gamma photons. For certain doses and dose rates, the RBE values computed for compensatory cellular proliferation clearly demonstrate the behavior that is commonly referred to as an inverse dose-rate effect, i.e., protraction of exposure may - under certain conditions - increase the magnitude of the dose response. Furthermore, because of non-linear rates for repair and repopulation, the highest RBEs are not necessarily found for the lowest doses nor the lowest RBEs always found at the highest doses. C1 OAK RIDGE NATL LAB, HLTH SCI RES DIV, OAK RIDGE, TN 37831 USA. OAK RIDGE NATL LAB, DIV MATH & COMP SCI, OAK RIDGE, TN 37831 USA. DEF NUCL AGCY, WASHINGTON, DC 20305 USA. NR 36 TC 6 Z9 6 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 1997 VL 72 IS 4 BP 530 EP 543 DI 10.1097/00004032-199704000-00004 PG 14 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 WN590 UT WOS:A1997WN59000005 PM 9119677 ER PT J AU Nystuen, A Costeff, H Elpeleg, ON Apter, N BonneTamir, B Mohrenweiser, H Haider, N Stone, EM Sheffield, VC AF Nystuen, A Costeff, H Elpeleg, ON Apter, N BonneTamir, B Mohrenweiser, H Haider, N Stone, EM Sheffield, VC TI Iraqi-Jewish kindreds with optic atrophy plus (3-methylglutaconic aciduria type 3) demonstrate linkage disequilibrium with the CTG repeat in the 3' untranslated region of the myotonic dystrophy protein kinase gene SO HUMAN MOLECULAR GENETICS LA English DT Article ID ANDROGEN RECEPTOR GENE; BEHRS SYNDROME; SYNDROME LOCUS; DNA; CHROMOSOME-15; MUTATIONS; PEDIGREE; CLONING; FAMILY; MAPS AB Iraqi-Jewish optic atrophy plus is an autosomal recessive condition characterized by infantile optic atrophy, an early onset movement disorder, and 3-methylglutaconic aciduria, Other features include spastic paraplegia, mild ataxia, mild cognitive deficiency and dysarthria. This disorder was identified in inbred Iraqi-Jewish kindreds in which relationships between most of the affected individuals were unknown, In this study we identify linkage to chromosome 19q13.2-q13.3 by using a DNA pooling strategy to perform a genome wide screen followed by a high density search for shared segments among affected individuals in candidate regions identified in the initial genome wide screen, A significantly high positive lod score of 6.14 at zero recombination was obtained for the CTG repeat in the 3' untranslated region of the myotonic dystrophy protein kinase gene, The existence of multiple recombinant individuals indicates the disease interval can be further narrowed with additional markers, Linkage disequilibrium was seen in six polymorphic markers across al Mb interval, This region is well characterized and contains several candidate genes. C1 UNIV IOWA,DEPT PEDIAT,IOWA CITY,IA 52242. UNIV IOWA,DEPT OPHTHALMOL,IOWA CITY,IA 52242. TEL AVIV UNIV,SACKLER FAC MED,DEPT HUMAN GENET,IL-69978 RAMAT AVIV,ISRAEL. SHAAREI TZEDEK MED CTR,METAB LAB,JERUSALEM,ISRAEL. LOWENSTEIN HOSP,NEUROPEDIAT REHABIL UNIT,RAANANA,ISRAEL. LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94551. FU NHGRI NIH HHS [P50HG00835, HG00457] NR 37 TC 16 Z9 16 U1 0 U2 0 PU OXFORD UNIV PRESS PI OXFORD PA GREAT CLARENDON ST, OXFORD, ENGLAND OX2 6DP SN 0964-6906 J9 HUM MOL GENET JI Hum. Mol. Genet. PD APR PY 1997 VL 6 IS 4 BP 563 EP 569 DI 10.1093/hmg/6.4.563 PG 7 WC Biochemistry & Molecular Biology; Genetics & Heredity SC Biochemistry & Molecular Biology; Genetics & Heredity GA WT546 UT WOS:A1997WT54600008 PM 9097959 ER PT J AU Levine, D Facello, M Hallstrom, P Reeder, G Walenz, B Stevens, F AF Levine, D Facello, M Hallstrom, P Reeder, G Walenz, B Stevens, F TI Stalk: An interactive system for virtual molecular docking SO IEEE COMPUTATIONAL SCIENCE & ENGINEERING LA English DT Article C1 ARGONNE NATL LAB,SCI & ENGN RES SEMESTER PROGRAM,ARGONNE,IL 60439. ARGONNE NATL LAB,CTR MECHANIST BIOL & BIOTECHNOL,ARGONNE,IL 60439. NR 12 TC 26 Z9 26 U1 0 U2 1 PU IEEE COMPUTER SOC PI LOS ALAMITOS PA 10662 LOS VAQUEROS CIRCLE, PO BOX 3014, LOS ALAMITOS, CA 90720-1314 SN 1070-9924 J9 IEEE COMPUT SCI ENG JI IEEE Comput. Sci. Eng. PD APR-JUN PY 1997 VL 4 IS 2 BP 55 EP 65 DI 10.1109/99.609834 PG 11 WC Computer Science, Theory & Methods; Engineering, Electrical & Electronic; Mathematics, Applied SC Computer Science; Engineering; Mathematics GA XH888 UT WOS:A1997XH88800011 ER PT J AU Page, RH Schaffers, KI DeLoach, LD Wilke, GD Patel, FD Tassano, JB Payne, SA Krupke, WF Chen, KT Burger, A AF Page, RH Schaffers, KI DeLoach, LD Wilke, GD Patel, FD Tassano, JB Payne, SA Krupke, WF Chen, KT Burger, A TI Cr2+-doped zinc chalcogenides as efficient, widely tunable mid-infrared lasers SO IEEE JOURNAL OF QUANTUM ELECTRONICS LA English DT Article DE chromium materials/devices; laser tuning; lasers; optical amplifiers; optical materials; solid lasers; zinc materials/devices ID MEASURING FRACTURE-TOUGHNESS; EXCITED-STATE ABSORPTION; PHYSICAL VAPOR TRANSPORT; THERMOMECHANICAL PROPERTIES; INDENTATION TECHNIQUES; CO-MGF2 LASER; CRYSTALS; PERFORMANCE; TM3+; YAG AB Transition-metal-doped zinc chalcogenide crystals have recently been investigated as potential mid-infrared lasers. Tetrahedrally coordinated Cr2+ ions are especially attractive as lasants on account of high luminescence quantum yields for emission in the 2000-3000-nm range. Radiative lifetimes and emission cross sections of the upper (5)E state are respectively similar to 10 mu s and similar to 10(-18) cm(2). The associated absorption band peaked at similar to 1800 nm enables laser-diode pumping of the Cr2+ systems. Laser demonstrations with ZnS:Cr and ZnSe:Cr (using a MgF2:Co2+ laser pump source) gave slope efficiencies up to 30%. Excited-state-absorption losses appear small, and passive losses dominate at present, Tuning experiments with a diffraction grating produce a tuning range covering at least 2150-2800 nm. Laser crystals can be produced by Bridgman growth, seeded physical vapor transport, or diffusion doping, Zinc chalcogenide thermomechanical properties of interest for medium-to-high-power operation compare favorably with those of other host materials, except for the larger refractive-index derivative dn/dT. C1 FISK UNIV,DEPT PHYS,CTR PHOTON MAT & DEVICES,NASHVILLE,TN 37208. RP Page, RH (reprint author), LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550, USA. NR 51 TC 234 Z9 241 U1 3 U2 54 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 1997 VL 33 IS 4 BP 609 EP 619 DI 10.1109/3.563390 PG 11 WC Engineering, Electrical & Electronic; Optics; Physics, Applied SC Engineering; Optics; Physics GA WP151 UT WOS:A1997WP15100014 ER PT J AU Ning, CZ Chow, WW Bossert, DJ Indik, RA Moloney, JV AF Ning, CZ Chow, WW Bossert, DJ Indik, RA Moloney, JV TI Influences of unconfined states on the optical properties of quantum-well structures SO IEEE JOURNAL OF SELECTED TOPICS IN QUANTUM ELECTRONICS LA English DT Article; Proceedings Paper CT 15th IEEE International Semiconductor Laser Conference (HAIFA 1996 ISLC) CY OCT 13-18, 1996 CL HAIFA, ISRAEL SP IEEE, Lasers & Electro Opt Soc, S Neaman Inst, ECI Telecom, Semiconductor Devices, Technion, Israel Inst Technol, Israeli Minist Sci & Arts ID SEMICONDUCTOR-LASERS; THRESHOLD CURRENT; LINEWIDTH ENHANCEMENT; MODULATION RESPONSE; GAIN AB The population of the unconfined states, with energies above the band edge of the barrier layers, can be significant in some regions of the active volume in high power lasers and amplifiers, This paper analyzes the influences of these states on optical properties, such as gain, refractive index, differential gain, and linewidth enhancement factor, for different quantum-well (QW) structures, Our results show that at high excitation levels, the unconfined band contributions to the real part of the optical susceptibility can be significant, especially in structures with weak quantum confinement potentials, This is in agreement with recent measurements of peak gain and carrier-induced refractive index change versus carrier density, for InGaAs-GaAs QW laser structures. C1 UNIV ARIZONA,ARIZONA CTR MATH SCI,TUCSON,AZ 85721. SANDIA NATL LABS,ALBUQUERQUE,NM 87185. USAF,PHILLIPS LAB,KIRTLAND AFB,NM 87117. RI Ning, C. Z./D-4699-2009 OI Ning, C. Z./0000-0003-4583-8889 NR 36 TC 11 Z9 11 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 1077-260X J9 IEEE J SEL TOP QUANT JI IEEE J. Sel. Top. Quantum Electron. PD APR PY 1997 VL 3 IS 2 BP 129 EP 135 DI 10.1109/2944.605642 PG 7 WC Engineering, Electrical & Electronic; Optics; Physics, Applied SC Engineering; Optics; Physics GA XP732 UT WOS:A1997XP73200002 ER PT J AU Chow, WW Knorr, A Hughes, S Girndt, A Koch, SW AF Chow, WW Knorr, A Hughes, S Girndt, A Koch, SW TI Carrier correlation effects in a quantum-well semiconductor laser medium SO IEEE JOURNAL OF SELECTED TOPICS IN QUANTUM ELECTRONICS LA English DT Article; Proceedings Paper CT 15th IEEE International Semiconductor Laser Conference (HAIFA 1996 ISLC) CY OCT 13-18, 1996 CL HAIFA, ISRAEL SP IEEE, Lasers & Electro Opt Soc, S Neaman Inst, ECI Telecom, Semiconductor Devices, Technion, Israel Inst Technol, Israeli Minist Sci & Arts DE collision processes; quantum theory; quantum-well lasers; semiconductor device modeling; semiconductor lasers ID SURFACE-EMITTING LASER; DEPENDENCE; GAIN; LINEWIDTH; THRESHOLD AB This paper describes the results of a microscopic treatment of carrier-carrier scattering effects in the optical gain and refractive index spectra of a quantum-well semiconductor laser structure, The approach uses the Semiconductor Maxwell Bloch equations to describe the interaction between the carriers and the laser field, in the presence of many-body Coulomb interactions, Coulomb correlation effects are treated at the level of quantum kinetic theory in the Markovian limit, This approach shows the presence of nondiagonal Coulomb correlation contributions, in addition to the familiar diagonal contributions giving rise to polarization dephasing. C1 UNIV MARBURG,DEPT PHYS,D-35032 MARBURG,GERMANY. UNIV MARBURG,CTR MAT SCI,D-35032 MARBURG,GERMANY. RP Chow, WW (reprint author), SANDIA NATL LABS,ALBUQUERQUE,NM, USA. NR 20 TC 33 Z9 33 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 1077-260X J9 IEEE J SEL TOP QUANT JI IEEE J. Sel. Top. Quantum Electron. PD APR PY 1997 VL 3 IS 2 BP 136 EP 141 DI 10.1109/2944.605645 PG 6 WC Engineering, Electrical & Electronic; Optics; Physics, Applied SC Engineering; Optics; Physics GA XP732 UT WOS:A1997XP73200003 ER PT J AU Hsu, CF Zory, PS Wu, CH Emanuel, MA AF Hsu, CF Zory, PS Wu, CH Emanuel, MA TI Coulomb enhancement in InGaAs-GaAs quantum-well lasers SO IEEE JOURNAL OF SELECTED TOPICS IN QUANTUM ELECTRONICS LA English DT Article; Proceedings Paper CT 15th IEEE International Semiconductor Laser Conference (HAIFA 1996 ISLC) CY OCT 13-18, 1996 CL HAIFA, ISRAEL SP IEEE, Lasers & Electro Opt Soc, S Neaman Inst, ECI Telecom, Semiconductor Devices, Technion, Israel Inst Technol, Israeli Minist Sci & Arts DE Coulomb enhancement; InGaAs quantum-well lasers; many-body effects; optical gain; spontaneous emission; threshold current; wavelength ID SEMICONDUCTOR-LASERS; GAIN AB It is shown that Coulomb enhancement (CE) has a significant influence on the spectral characteristics of optical gain and spontaneous emission in strained InGaAs quantum wens. CE-modified gain spectra are utilized to make an accurate prediction of the dependence of lasing wavelength on cavity length, Threshold-current predictions using the CE-modified gain-current relation show improved agreement with experiment. C1 LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94557. RP Hsu, CF (reprint author), UNIV FLORIDA,DEPT ELECT & COMP ENGN,GAINESVILLE,FL 32611, USA. NR 22 TC 31 Z9 31 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 1077-260X J9 IEEE J SEL TOP QUANT JI IEEE J. Sel. Top. Quantum Electron. PD APR PY 1997 VL 3 IS 2 BP 158 EP 165 DI 10.1109/2944.605649 PG 8 WC Engineering, Electrical & Electronic; Optics; Physics, Applied SC Engineering; Optics; Physics GA XP732 UT WOS:A1997XP73200006 ER PT J AU Vawter, GA Smith, RE Hou, H Wendt, JR AF Vawter, GA Smith, RE Hou, H Wendt, JR TI Semiconductor laser with tapered-rib adiabatic-following fiber coupler for expanded output-mode diameter SO IEEE PHOTONICS TECHNOLOGY LETTERS LA English DT Article DE adiabatic optical waveguide transitions; optical fiber coupling; optical waveguides; plasma materials-processing applications; quantum-well lasers; semiconductor lasers; semiconductor waveguides; waveguide transitions ID WAVE-GUIDE; DESIGN AB A new expanded-mode diode laser with reduced farfield divergence and 0.9 dB single-mode optical fiber coupling loss is demonstrated, This new laser achieves a two-dimensional (2-D) expansion of the fundamental output mode with a rib waveguide tapered in only one dimension, Stable fundamental-mode operation with a narrow, 5.7 degrees by 7.4 degrees full-width-at-half-maximum far-field divergence is observed well above lasing threshold, Tapered waveguide dimensions are compatible with conventional optical lithographic techniques, making this device suitable for mass production. RP Vawter, GA (reprint author), SANDIA NATL LABS,POB 5800,ALBUQUERQUE,NM 87185, USA. NR 7 TC 30 Z9 31 U1 3 U2 7 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 1041-1135 J9 IEEE PHOTONIC TECH L JI IEEE Photonics Technol. Lett. PD APR PY 1997 VL 9 IS 4 BP 425 EP 427 DI 10.1109/68.559376 PG 3 WC Engineering, Electrical & Electronic; Optics; Physics, Applied SC Engineering; Optics; Physics GA WP155 UT WOS:A1997WP15500005 ER PT J AU Hutchinson, SA Ng, KT Shadid, JN Nadeem, A AF Hutchinson, SA Ng, KT Shadid, JN Nadeem, A TI Electrical defibrillation optimization: An automated, iterative parallel finite-element approach SO IEEE TRANSACTIONS ON BIOMEDICAL ENGINEERING LA English DT Article DE biomedical computing; defibrillators; distributed computing; electrodes; finite element methods; optimization methods; parallel direct search method ID CARDIAC DEFIBRILLATION; PADDLE PLACEMENT; CURRENT FLOW; HUMAN THORAX; COMPUTER; MODEL; DOGS; SIZE AB To date, optimization of electrode systems for electrical defibrillation has been limited to hand-selected electrode configurations, In this paper we present an automated approach which combines detailed, three-dimensional (3-D) finite-element torso models with optimization techniques to provide a flexible analysis and design tool for electrical defibrillation optimization, Specifically, a parallel direct search (PDS) optimization technique is used with a representative objective function to find an electrode configuration which corresponds to the satisfaction of a postulated defibrillation criterion with a minimum amount of power and a low possibility of myocardium damage, For adequate representation of the thoracic inhomogeneities, 3-D finite-element torso models are used in the objective function computations, The CPU-intensive finite-element calculations required for the objective function evaluation have been implemented on a message-passing parallel computer in order to complete the optimization calculations in a timely manner, To illustrate the optimization procedure, it has been applied to a representative electrode configuration for transmyocardial defibrillation, namely the subcutaneous patch-right ventricular catheter (SP-RVC) system, Sensitivity of the optimal solutions to various tissue conductivities has been studied, Results for the optimization of defibrillation systems are presented which demonstrate the feasibility of the approach. C1 SANDIA NATL LABS,PARALLEL COMPUTAT SCI DEPT,ALBUQUERQUE,NM 87185. NEW MEXICO STATE UNIV,KLIPSCH SCH ELECT & COMP ENGN,LAS CRUCES,NM 88003. FU NHLBI NIH HHS [R01-HL-44747] NR 39 TC 4 Z9 5 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 0018-9294 J9 IEEE T BIO-MED ENG JI IEEE Trans. Biomed. Eng. PD APR PY 1997 VL 44 IS 4 BP 278 EP 289 DI 10.1109/10.563297 PG 12 WC Engineering, Biomedical SC Engineering GA WN995 UT WOS:A1997WN99500006 PM 9125810 ER PT J AU Castoldi, A Rehak, P Holl, P AF Castoldi, A Rehak, P Holl, P TI Signal charge sharing in multilinear drift detectors: Design and experimental characterization SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article DE charge sharing; electron broadening; silicon drift detectors ID X-RAY SPECTROSCOPY AB Multilinear silicon drift detectors (MLSDD's) are radiation detectors which combine excellent energy and position resolution with high count-rate capabilities, This is achieved by controlling the diffusion of the signal charges and limiting their lateral spread during the drift, This paper will present a study of the signal electrons' transport in MLSDD's in comparison with the experimental measurements, Three-dimensional simulations were carried out, taking into account diffusion effects and mutual electrostatic interaction between the signal electrons. A representative sample of these simulations will he presented, Signal sharing in a multilinear drift detector and in a ''classical'' multi-anode drift detector are characterized and discussed, The results are useful to tailor the design of MLSDD's for the detection of different kinds of radiation (e.g., optical photon, X-ray, ionizing particle) and to optimize signal charge sharing and detector performance according to a particular application purpose. C1 BROOKHAVEN NATL LAB,UPTON,NY 11973. 3MPI HALBLEITERLABOR,D-81245 MUNICH,GERMANY. RP Castoldi, A (reprint author), UNIV MILAN,DIP FIS,I-20133 MILAN,ITALY. NR 15 TC 24 Z9 24 U1 1 U2 4 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 1997 VL 44 IS 2 BP 134 EP 141 DI 10.1109/23.568794 PG 8 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA WU143 UT WOS:A1997WU14300003 ER PT J AU Norton, SJ AF Norton, SJ TI A general nonlinear inverse transport algorithm using forward and adjoint flux computations SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article DE adjoint flux; imaging; inverse problem; inverse transport problem; nonlinear inverse transport ID SCATTERING COEFFICIENTS AB Iterative approaches to the nonlinear inverse transport problem are described, which give rise to the structure that best predicts a set of transport observations, Such methods are based on minimizing a global error functional measuring the discrepancy between predicted and observed transport data, Required for this minimization is the functional gradient (Frechet derivative) of the global error evaluated with respect to a set of unknown material parameters (specifying boundary locations, scattering cross sections, etc.) which are to be determined, It is shown how this functional gradient is obtained from numerical solutions to the forward and adjoint transport problems computed once per iteration, This approach is not only far more efficient, but also more accurate, than a finite-difference method for computing the gradient of the global error, The general technique can be applied to inverse-transport problems of all descriptions, provided only that solutions to the forward and adjoint problems can be found numerically, As an illustration, two inverse problems are treated: the reconstruction of an anisotropic scattering function in a one-dimensional homogeneous slab and the two-dimensional ''imaging'' of a spatially-varying scattering cross section. RP Norton, SJ (reprint author), OAK RIDGE NATL LAB,OAK RIDGE,TN 37831, USA. NR 22 TC 11 Z9 11 U1 1 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 1997 VL 44 IS 2 BP 153 EP 162 DI 10.1109/23.568797 PG 10 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA WU143 UT WOS:A1997WU14300006 ER PT J AU Tosaka, Y Satoh, S Suzuki, K Sugii, T Nakayama, N Ehara, H Woffinden, GA Wender, SA AF Tosaka, Y Satoh, S Suzuki, K Sugii, T Nakayama, N Ehara, H Woffinden, GA Wender, SA TI Measurements and analysis of neutron-reaction-induced charges in a silicon surface region SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article ID HEAVY-ION REACTIONS; SINGLE EVENT UPSET; COSMIC-RAYS; COLLISIONS AB We directly measured neutron-reaction-induced charges in the silicon surface region using silicon-on-insulator (SOI) test structures. Because the neutron beam used has an energy spectrum similar to that of sea-level atmospheric neutrons, our charge collection data correspond to those induced by cosmic ray neutrons. Measured charge collection spectra were dependent on the SOI thickness and agreed with simulated results, An application for the neutron-induced upset rate prediction was also discussed. Furthermore, the charge collection components were separated by our charge collection simulator. C1 FUJITSU LABS LTD,NAKAHARA KU,KAWASAKI,KANAGAWA 211,JAPAN. AMDAHL CORP,SUNNYVALE,CA. LOS ALAMOS NATL LAB,LOS ALAMOS,NM. RP Tosaka, Y (reprint author), FUJITSU LABS LTD,10-1 MORINOSATO WAKAMIYA,ATSUGI,KANAGAWA 24301,JAPAN. NR 24 TC 18 Z9 18 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 1997 VL 44 IS 2 BP 173 EP 178 DI 10.1109/23.568799 PG 6 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA WU143 UT WOS:A1997WU14300008 ER PT J AU Caselles, V Kimmel, R Sapiro, G AF Caselles, V Kimmel, R Sapiro, G TI Minimal surfaces based object segmentation SO IEEE TRANSACTIONS ON PATTERN ANALYSIS AND MACHINE INTELLIGENCE LA English DT Article DE 3D segmentation; minimal surfaces; deformable models; mean curvature motion; medical images ID ACTIVE CONTOUR MODELS; PLANE-CURVES; 3-D IMAGES; LEVEL; DEFORMATIONS; PROPAGATION; BALLOONS; SHAPE; SPACE AB A geometric approach for 3D object segmentation and representation is presented. The segmentation is obtained by deformable surfaces moving towards the objects to be detected in the 3D image. The model is based on curvature motion and the computation of surfaces with minimal areas, better known as minimal surfaces. The space where the surfaces are computed is induced from the 3D image (volumetric data) in which the objects are to be detected. The model links between classical deformable surfaces obtained via energy minimization, and intrinsic ones derived from curvature based flows. The new approach is stable, robust, and automatically handles changes in the surface topology during the deformation. C1 UNIV CALIF BERKELEY, LAWRENCE BERKELEY LAB, BERKELEY, CA 94720 USA. HEWLETT PACKARD CORP, PALO ALTO, CA 94304 USA. RP UNIV ILLES BALEARS, DEPT MATH & INFORMAT, E-07071 PALMA DE MALLORCA, SPAIN. RI Sbert, Catalina/K-8768-2014 NR 36 TC 131 Z9 131 U1 0 U2 6 PU IEEE COMPUTER SOC PI LOS ALAMITOS PA 10662 LOS VAQUEROS CIRCLE, PO BOX 3014, LOS ALAMITOS, CA 90720-1314 USA SN 0162-8828 EI 1939-3539 J9 IEEE T PATTERN ANAL JI IEEE Trans. Pattern Anal. Mach. Intell. PD APR PY 1997 VL 19 IS 4 BP 394 EP 398 DI 10.1109/34.588023 PG 5 WC Computer Science, Artificial Intelligence; Engineering, Electrical & Electronic SC Computer Science; Engineering GA WW122 UT WOS:A1997WW12200009 ER PT J AU Woods, K Kegelmeyer, WP Bowyer, K AF Woods, K Kegelmeyer, WP Bowyer, K TI Combination of multiple classifiers using local accuracy estimates SO IEEE TRANSACTIONS ON PATTERN ANALYSIS AND MACHINE INTELLIGENCE LA English DT Article DE combination of classifiers; dynamic classifier selection; local classifier accuracy; classifier fusion; ROC analysis ID RECOGNITION; ALGORITHMS AB This paper presents a method for combining classifiers that uses estimates of each individual classifier's local accuracy in small regions of feature space surrounding an unknown test sample. An empirical evaluation using five real data sets confirms the validity of our approach compared to some other Combination of Multiple Classifiers algorithms. We also suggest a methodology for determining the best mix of individual classifiers. C1 SANDIA NATL LABS, CTR COMPUTAT ENGN, LIVERMORE, CA 94551 USA. RP Woods, K (reprint author), UNIV S FLORIDA, DEPT COMP SCI & ENGN, 4202 FOWLER AVE, ENB 118, TAMPA, FL 33620 USA. OI Bowyer, Kevin/0000-0002-7562-4390 NR 18 TC 479 Z9 494 U1 3 U2 21 PU IEEE COMPUTER SOC PI LOS ALAMITOS PA 10662 LOS VAQUEROS CIRCLE, PO BOX 3014, LOS ALAMITOS, CA 90720-1314 USA SN 0162-8828 J9 IEEE T PATTERN ANAL JI IEEE Trans. Pattern Anal. Mach. Intell. PD APR PY 1997 VL 19 IS 4 BP 405 EP 410 DI 10.1109/34.588027 PG 6 WC Computer Science, Artificial Intelligence; Engineering, Electrical & Electronic SC Computer Science; Engineering GA WW122 UT WOS:A1997WW12200011 ER PT J AU Loubriel, GM Zutavern, FJ Baca, AG Hjalmarson, PP Plut, TA Helgeson, WD OMalley, MW Ruebush, MH Brown, DJ AF Loubriel, GM Zutavern, FJ Baca, AG Hjalmarson, PP Plut, TA Helgeson, WD OMalley, MW Ruebush, MH Brown, DJ TI Photoconductive semiconductor switches SO IEEE TRANSACTIONS ON PLASMA SCIENCE LA English DT Article AB Optically activated GaAs switches operated in their high-gain mode are being used or tested for pulsed power applications as diverse as low-impedance, high-current firing sets in munitions; high-impedance, low-current Pockels cell or Q-switch drivers for lasers; high-voltage drivers for laser diode arrays; high-voltage, high-current, compact accelerators; and pulsers for ground penetrating radar. This paper will describe the properties of high-gain photoconductive semiconductor switches (PCSS), and how they are used in a variety of pulsed power applications. For firing sets, we have switched up to 7 kA in a very compact package. For driving Q switches, the load is the small (30 pF) capacitance of the P switch which is charged to 6 kV. We have demonstrated that we can modulate a laser beam with a subnanosecond rise time. Using PCSS, we have demonstrated gain switching a series-connected laser diode array, obtaining an optical output,vith a peak power of 50 kW and a pulse duration of 100 ps. For accelerators, we are using PCSS to switch a 260 kV, 60 kA Blumlein. A pulser suitable for use in ground-penetrating radar has been demonstrated at 100 kV, 1.3 kA. This paper will describe the specific project requirements and switch parameters in all of these applications, and emphasize the switch research and development that is being pursued to address the important issues. RP Loubriel, GM (reprint author), SANDIA NATL LABS,POB 5800,ALBUQUERQUE,NM 87185, USA. NR 15 TC 69 Z9 83 U1 1 U2 23 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0093-3813 J9 IEEE T PLASMA SCI JI IEEE Trans. Plasma Sci. PD APR PY 1997 VL 25 IS 2 BP 124 EP 130 DI 10.1109/27.602482 PG 7 WC Physics, Fluids & Plasmas SC Physics GA XK560 UT WOS:A1997XK56000004 ER PT J AU Buyko, AM Bidylo, NP Chernyshev, VK Demidov, VA Garanin, SF Kostyukov, VN Kulagin, AA Kuzyaev, AI Mezhevov, AB Mokhov, VN Pavlovskiy, ES Petrukhin, AA Yakubov, VB Yegorychev, BT Canada, JW Ekdahl, CA Goforth, JH King, JC Lindemuth, IR Reinovsky, RE Rodriguez, P Smith, RC Veeser, LR Younger, SM AF Buyko, AM Bidylo, NP Chernyshev, VK Demidov, VA Garanin, SF Kostyukov, VN Kulagin, AA Kuzyaev, AI Mezhevov, AB Mokhov, VN Pavlovskiy, ES Petrukhin, AA Yakubov, VB Yegorychev, BT Canada, JW Ekdahl, CA Goforth, JH King, JC Lindemuth, IR Reinovsky, RE Rodriguez, P Smith, RC Veeser, LR Younger, SM TI Results of Russian/US high-performance DEMG experiment SO IEEE TRANSACTIONS ON PLASMA SCIENCE LA English DT Article AB In November 1992, the All-Russian Scientific Research Institute of Experimental Physics (VNIIEF), Arzamas-16, Russia and the Los Alamos National Laboratory, Los Alamos NM, USA embarked on a historic effort to conduct a joint explosive pulse-power experiment. With the concurrence of the Ministry of Atomic Energy (Russia) and the Department of Energy (U.S.), the two laboratories entered into a laboratory-to-laboratory collaboration in the areas of very high-energy pulse power and ultrahigh magnetic fields in order to explore problems of mutual scientific interest, The first experiment to be planned was an explosively powered, fast, high-current pulse-power system demonstration, The experiment used a flux compressor, inductive store, and high-current opening switch to demonstrate the feasibility of supplying many megajoules of electrical energy, on microsecond time scales, to high-energy density physics experiments. The experiment was conducted in Arzamas-16 on September 22, 1993. C1 LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545. RP Buyko, AM (reprint author), ALL RUSSIAN SCI RES INST EXPT PHYS,ARZAMAS 16,NIZHNI NOVGOROD,RUSSIA. NR 6 TC 3 Z9 3 U1 0 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0093-3813 J9 IEEE T PLASMA SCI JI IEEE Trans. Plasma Sci. PD APR PY 1997 VL 25 IS 2 BP 145 EP 154 DI 10.1109/27.602485 PG 10 WC Physics, Fluids & Plasmas SC Physics GA XK560 UT WOS:A1997XK56000007 ER PT J AU Ramirez, JJ AF Ramirez, JJ TI The X-1 Z-pinch driver SO IEEE TRANSACTIONS ON PLASMA SCIENCE LA English DT Article AB X-1 is a program initiative to develop the next-generation laboratory X-ray source using fast Z-pinch drivers, X-l will provide unique applications utility to high-energy density physics, inertial confinement fusion, and radiation effects simulation research, The advent in the 1980's of pulsed power accelerators capable of delivering tens of terawatts to imploding plasma loads led to a quantum improvement in Z-pinch performance by reducing the implosion time to less than 100 ns, Further progress in Z-pinch performance capabilities was achieved in 1996, using a cylindrical wire-array load, and led to the production of 85 TW, 350-500 kJ of X-rays using the Saturn accelerator at Sandia. The PBFA-II accelerator has been converted to drive Z-pinch loads (PBFA-Z), and will provide a factor of 2 increase in current, and 4 in energy, over-that provided by Saturn, X-l is the next step beyond PBFA-Z and, as presently envisioned, represents a factor of 8 increase in energy, It will require a similar to 360 TW, similar to 100 ns pulsed power generator to impart similar to 16 MJ kinetic energy to the reference imploding plasma load, A baseline concept for X-l has been developed, It utilizes a highly modular, robust architecture with demonstrated performance reliability. RP Ramirez, JJ (reprint author), SANDIA NATL LABS,POB 5800,ALBUQUERQUE,NM 87185, USA. NR 9 TC 14 Z9 19 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 0093-3813 J9 IEEE T PLASMA SCI JI IEEE Trans. Plasma Sci. PD APR PY 1997 VL 25 IS 2 BP 155 EP 159 DI 10.1109/27.602486 PG 5 WC Physics, Fluids & Plasmas SC Physics GA XK560 UT WOS:A1997XK56000008 ER PT J AU Parsons, WM Ballard, EO Bartsch, RR Benage, JF Bennett, GA Bowers, RL Bowman, DW Brownell, JH Cochrane, JC Davis, HA Ekdahl, CA Gribble, RF Griego, JR Goldstone, PD Jones, ME Hinckley, WB Hosack, KW Kasik, RJ Lee, H Lopez, EA Lindemuth, IR Monroe, MD Moses, RW Ney, SA Platts, D Reass, WA Salazar, HR Sandoval, GM Scudder, DW Shlachter, JS Thompson, MC Trainor, RJ Valdez, GA Watt, RG Wurden, GA Younger, SM AF Parsons, WM Ballard, EO Bartsch, RR Benage, JF Bennett, GA Bowers, RL Bowman, DW Brownell, JH Cochrane, JC Davis, HA Ekdahl, CA Gribble, RF Griego, JR Goldstone, PD Jones, ME Hinckley, WB Hosack, KW Kasik, RJ Lee, H Lopez, EA Lindemuth, IR Monroe, MD Moses, RW Ney, SA Platts, D Reass, WA Salazar, HR Sandoval, GM Scudder, DW Shlachter, JS Thompson, MC Trainor, RJ Valdez, GA Watt, RG Wurden, GA Younger, SM TI The atlas project - A new pulsed power facility for high energy density physics experiments SO IEEE TRANSACTIONS ON PLASMA SCIENCE LA English DT Article AB Atlas is a facility being designed at Los Alamos National Laboratory (LANL) to perform high-energy-density experiments in support of weapon physics and basic research programs. It is designed to be an international user facility, providing experimental opportunities to researchers from national laboratories and academic institutions. For hydrodynamic experiments, it will be capable of achieving a pressure exceeding 30 Mbar in a several cubic centimeter volume. With the development of a suitable opening switch, it will be capable of producing more than 3 MJ of soft X-rays. The capacitor bank design consists of a 36 MJ array of 240 kV Marx modules. The system is designed to deliver a peak current of 45-50 MA with a 4-5-mu s rise time. The Marx modules are designed to be reconfigured to a 480-kV configuration for opening switch development. The capacitor bank is resistively damped to limit fault currents and capacitor voltage reversal. An experimental program for testing and certifying prototype components is currently underway. The capacitor bank design contains 300 closing switches. These switches are a modified version of a railgap switch originally designed for the DNA-ACE machines. Because of the large number of switches in the system, individual switch prefire rates must be less than 10(-4) to protect the expensive target assemblies. Experiments are underway to determine if the switch-prefire probability can be reduced with rapid capacitor charging. RP Parsons, WM (reprint author), LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545, USA. RI Wurden, Glen/A-1921-2017 OI Wurden, Glen/0000-0003-2991-1484 NR 13 TC 11 Z9 11 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 0093-3813 J9 IEEE T PLASMA SCI JI IEEE Trans. Plasma Sci. PD APR PY 1997 VL 25 IS 2 BP 205 EP 211 DI 10.1109/27.602492 PG 7 WC Physics, Fluids & Plasmas SC Physics GA XK560 UT WOS:A1997XK56000014 ER PT J AU Cuneo, ME Menge, PR Hanson, DL Fowler, WE Bernard, MA Ziska, GR Filuk, AB Pointon, TD Vesey, RA Welch, DR Bailey, JE Desjarlais, MP Lockner, TR Mehlhorn, TA Slutz, SA Stark, MA AF Cuneo, ME Menge, PR Hanson, DL Fowler, WE Bernard, MA Ziska, GR Filuk, AB Pointon, TD Vesey, RA Welch, DR Bailey, JE Desjarlais, MP Lockner, TR Mehlhorn, TA Slutz, SA Stark, MA TI Results of vacuum cleaning techniques on the performance of LiF field-threshold ion sources on extraction applied-B ion diodes at 1-10 TW SO IEEE TRANSACTIONS ON PLASMA SCIENCE LA English DT Article ID ELECTRON-BEAM DIODE; ANODE PLASMA SOURCE; GLOW-DISCHARGE; LITHIUM-FLUORIDE; FLASHOVER; EMISSION; ACCELERATORS; IMPEDANCE; SURFACES; FLOW AB Uncontrolled plasma formation on electrode surfaces limits performance in a wide variety of pulsed power devices such as electron and ion diodes, transmission lines, radio frequency (RF) cavities, and microwave devices. Surface and bulk contaminants on the electrodes in vacuum dominate the composition of these plasmas, formed through processes such as stimulated and thermal desorption followed by ionization. We are applying RF discharge cleaning, anode heating, cathode cooling, and substrate surface coatings to the control of the effects of these plasmas in the particular case of applied-B ion diodes on the SABRE (1 TW) and PBFA-X (30 TW) accelerators. Evidence shows that our LiF ion source provides a 200-700 A/cm(2) lithium beam for 10-20 ns which is then replaced by a contaminant beam of protons and carbon. Other ion sources show similar behavior, Our electrode surface and substrate cleaning techniques reduce beam contamination, anode and cathode plasma formation, delay impedance collapse, and increase Lithium energy, power, and production efficiency. Theoretical and simulation models of electron-stimulated and thermal-contaminant desorption leading to anode plasma formation show agreement with many features from experiment, Decrease of the diode electron loss by changing the shape and magnitude of the insulating magnetic field profiles increases the lithium output and changes the diode response to cleaning. We also show that the LiF films are permeable, allowing substrate contaminants to affect diode behavior, Substrate coatings of Ta and Au underneath the LiF film allow some measure of control of substrate contaminants, and provide direct evidence for thermal desorption. We have increased lithium current density by a factor of four and lithium energy by a factor of five through a combination of in situ surface and substrate cleaning, substrate coatings, and field profile modifications. C1 MISSION RES CORP,ALBUQUERQUE,NM 87106. RP Cuneo, ME (reprint author), SANDIA NATL LABS,PULSED POWER SCI CTR,POB 5800,ALBUQUERQUE,NM 87185, USA. NR 87 TC 42 Z9 43 U1 2 U2 10 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0093-3813 J9 IEEE T PLASMA SCI JI IEEE Trans. Plasma Sci. PD APR PY 1997 VL 25 IS 2 BP 229 EP 251 DI 10.1109/27.602495 PG 23 WC Physics, Fluids & Plasmas SC Physics GA XK560 UT WOS:A1997XK56000017 ER PT J AU Menge, PR Cuneo, ME AF Menge, PR Cuneo, ME TI Quantitative cleaning characterization of a lithium-fluoride ion diode SO IEEE TRANSACTIONS ON PLASMA SCIENCE LA English DT Article ID GLOW-DISCHARGE; STAINLESS-STEEL; PBFA-II; ACCELERATOR AB An ion source cleaning testbed was created to test plasma-cleaning techniques, and to provide quantitative data on plasma-cleaning protocols prior to implementation on the SABRE accelerator, The testbed was designed to resolve issues regarding the quantity of contaminants absorbed by the anode source (LiF), and the best cleaning methodology, A test chamber was devised containing a duplicate of the SABRE diode. Radio-frequency (RF) power was fed to the anode, which was isolated from ground and thus served as the plasma discharge electrode. RF plasma discharges in 1-3 mtorr of Ar with 10% O-2 were found to provide the best cleaning of the LiF surface, X-ray photoelectron spectroscopy (XPS) showed that the LIF could accrue dozens of monolayers of carbon just by sitting in a 2 x 10(-5) vacuum for 24 h. Tests of various discharge cleaning protocols indicated that 15 min of an Ar/O-2 discharge was sufficient to reduce this initial 13-45 monolayers of carbon impurities to 2-4 monolayers, Rapid recontamination of the LiF was also observed, Up to ten monolayers of carbon returned in 2 min after termination of the plasma discharge and subsequent pumping back to the 10(-5) torr range, Heating of the LiF also was found to provide anode cleaning. Application of heating combined with plasma cleaning provided the highest cleaning rates. RP Menge, PR (reprint author), SANDIA NATL LABS,INTENSE BEAM RES DEPT,POB 5800,ALBUQUERQUE,NM 87185, USA. NR 17 TC 11 Z9 11 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 0093-3813 J9 IEEE T PLASMA SCI JI IEEE Trans. Plasma Sci. PD APR PY 1997 VL 25 IS 2 BP 252 EP 257 DI 10.1109/27.602496 PG 6 WC Physics, Fluids & Plasmas SC Physics GA XK560 UT WOS:A1997XK56000018 ER PT J AU Rohwein, GJ AF Rohwein, GJ TI An efficient, power-enhanced ignition system SO IEEE TRANSACTIONS ON PLASMA SCIENCE LA English DT Article AB Spark ignition engines typically have ignition systems that develop 20-30 kV for breakdown of the spark plug gap and deliver current pulses in the range of 30-100 mA, These systems are characterized by very low energy transfer efficiency, 1% or less, Most of the energy is dissipated by the resistances in the transformer, spark plug wires, and spark plugs, This operating mode is adequate (but not necessarily optimum) for most engines, but will not meet the needs of future lean burn and some alternate fuel engines that require higher energy discharges to effectively ignite air/fuel mixtures. Requirements for increased ignition power and energy will have to be met with higher efficiency ignition systems, Improved efficiency can be achieved by utilizing peaking capacitors in the secondary circuit, preferably with a low-loss spark coil, With these modifications, the transfer efficiency can be increased to the 50-75% range, This paper summarizes the results of recent high-power ignition experiments and related electrical system analyzes for so-called ''breakdown ignition'' conditions, It includes descriptions of conventional ignition systems, a method for upgrading, and a new higher energy system that features multiple drivers and an energy recovery circuit, The effects of power-enhanced ignition on mileage and emissions for a variety of vehicles tested in laboratory and on the road are summarized sufficiently to show a range of typical results, The paper does not include comprehensive test data for a wide range of vehicles and operating conditions. RP Rohwein, GJ (reprint author), SANDIA NATL LABS,POB 5800,ALBUQUERQUE,NM 87185, USA. NR 14 TC 5 Z9 6 U1 0 U2 7 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0093-3813 J9 IEEE T PLASMA SCI JI IEEE Trans. Plasma Sci. PD APR PY 1997 VL 25 IS 2 BP 306 EP 310 DI 10.1109/27.602504 PG 5 WC Physics, Fluids & Plasmas SC Physics GA XK560 UT WOS:A1997XK56000026 ER PT J AU Thomas, VA AF Thomas, VA TI Modeling combined collisional/collisionless plasma interpenetration SO IEEE TRANSACTIONS ON PLASMA SCIENCE LA English DT Article AB This paper describes one technique by which multifluid modeling capability can be achieved within the context of a Lagrangean single-fluid model, This technique is applied to the interpenetration of laser-produced, substantially collisionless plasmas. A single-fluid model by itself cannot simulate the interpenetration of a collisionless plasma correctly, but must be augmented with some other tool, One tool that can calculate collisionless plasma interpenetration correctly is ISIS, a particle code for plasma simulations which includes appropriate collision models. However, ISIS does not have the necessary physics to do the laser deposition, the atomic physics, the radiation transport, and does not possess a realistic electron temperature model, With appropriate integration of the single-fluid code and ISIS, a new capability is achieved which allows simulation of the colliding plasma problem, a problem that neither code can properly simulate individually. RP Thomas, VA (reprint author), LOS ALAMOS NATL LAB,POB 1663,LOS ALAMOS,NM 87545, USA. NR 9 TC 1 Z9 1 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 0093-3813 J9 IEEE T PLASMA SCI JI IEEE Trans. Plasma Sci. PD APR PY 1997 VL 25 IS 2 BP 353 EP 359 DI 10.1109/27.602511 PG 7 WC Physics, Fluids & Plasmas SC Physics GA XK560 UT WOS:A1997XK56000033 ER PT J AU Lemke, RW Calico, SE Clark, MC AF Lemke, RW Calico, SE Clark, MC TI Investigation of a load-limited, magnetically insulated transmission line oscillator (MILO) SO IEEE TRANSACTIONS ON PLASMA SCIENCE LA English DT Article ID FLOW AB The magnetically insulated transmission line oscillator (MILO) is a crossed-field microwave tube that is closely related to the linear magnetron. We discuss research involving a MILO whose de operating characteristics (voltage and impedance) are determined by a current-carrying load. The load also forms part of a unique power extraction scheme. We show that maximum power is obtained from the load-limited MILO when an RF choke is used for the upstream boundary. This efficiency-enhanced version of the load-limited MILO yields gigawatt-level output power in both experiments and numerical simulations, results of which are also presented. In addition, we use the parapotential theory of magnetically insulated transmission lines in conjunction with observed simulation results to obtain estimates of maximum spoke current, spoke drift velocity, and maximum efficiency. C1 USAF,PHILLIPS LAB,KIRTLAND AFB,NM 87117. RP Lemke, RW (reprint author), SANDIA NATL LABS,POB 5800,ALBUQUERQUE,NM 87185, USA. NR 19 TC 94 Z9 124 U1 0 U2 4 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0093-3813 J9 IEEE T PLASMA SCI JI IEEE Trans. Plasma Sci. PD APR PY 1997 VL 25 IS 2 BP 364 EP 374 DI 10.1109/27.602513 PG 11 WC Physics, Fluids & Plasmas SC Physics GA XK560 UT WOS:A1997XK56000035 ER PT J AU Chang, JJ Arnold, PA Warner, BE AF Chang, JJ Arnold, PA Warner, BE TI Improvement of high-current large-volume discharge with profiled hollow-cathode electrodes SO IEEE TRANSACTIONS ON PLASMA SCIENCE LA English DT Article ID COPPER LASER; HIGH-POWER; INSTABILITY; PLASMA; FIELD AB Filamentary discharge at the electrode of high-power copper vapor lasers prevents stable operation when the buffer gas (Ne) pressures exceeds 30 torr. Experimental evidence indicates that the discharge constriction starts in the cathode fall region. The volumetric power deposition at the cathode fall is estimated to be similar to 130 MW/cm(3) at 40 torr during a peak discharge current of 2.5 KA This highly pressure-dependent (proportional to P-7/3) large thermal loading at cathode fall is likely to initiate thermal instability as pressure increases. This discharge instability can be mitigated by taking advantage of the hollow-cathode effect even for pressures exceeding 100 torr. We have designed a large-area electrode with many hollow-cathode grooves spreading over the uniform-field-profile area of the electrode for enhanced electron emission. This unique design lowers the cathode-fall voltage, and as a consequence, reduces the thermal loading at the cathode fall. With this profiled, hollow-cathode electrode, we have successfully extended stable discharge from similar to 30 to similar to 100 torr. We believe this profiled electrode design with multiple hollow-cathode grooves will expand hollow-cathode electrodes to many applications that require high-current large-volume discharge at elevated pressure. RP Chang, JJ (reprint author), LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94551, USA. NR 31 TC 5 Z9 5 U1 1 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0093-3813 J9 IEEE T PLASMA SCI JI IEEE Trans. Plasma Sci. PD APR PY 1997 VL 25 IS 2 BP 392 EP 399 DI 10.1109/27.602517 PG 8 WC Physics, Fluids & Plasmas SC Physics GA XK560 UT WOS:A1997XK56000039 ER PT J AU Elnagar, GN Khamayseh, A AF Elnagar, GN Khamayseh, A TI On the optimal spectral Chebyshev solution of a controlled nonlinear dynamical system SO IMA JOURNAL OF APPLIED MATHEMATICS LA English DT Article AB In a recent paper we considered the numerical solution of the controlled Duffing oscillator: minimize J = 1/2 integral(-T)(0) U-2(tau) d tau, subject to X (tau) + w(2)X (tau) + epsilon X-2(tau) = U(tau) (-T less than or equal to tau less than or equal to 0), where T is known, with X(-T) = x(0), X(0) = 0, by the pseudospectral Legendre method, which shows that in order to maintain spectral accuracy the grids on which a physical problem is to be solved must also be obtained by spectrally accurate techniques. This paper presents an alternative spectrally accurate computational method of solving the nonlinear controlled Duffing oscillator. The method is based upon constructing the Mth-degree interpolation polynomials, using Chebyshev nodes, to approximate the state and the control vectors. The differential and integral expressions which arise from the system dynamics and the performance index are converted into an algebraic nonlinear programming problem. The results of computer-simulation studies compare favourably with optimal solutions obtained by closed-form analysis and/or by other numerical schemes. C1 LOS ALAMOS NATL LAB,CTR NONLINEAR STUDIES,LOS ALAMOS,NM 87545. RP Elnagar, GN (reprint author), UNIV S CAROLINA,DEPT MATH & COMP SCI,SPARTANBURG,SC 29303, USA. NR 18 TC 3 Z9 3 U1 0 U2 0 PU OXFORD UNIV PRESS PI OXFORD PA GREAT CLARENDON ST, OXFORD, ENGLAND OX2 6DP SN 0272-4960 J9 IMA J APPL MATH JI IMA J. Appl. Math. PD APR PY 1997 VL 58 IS 2 BP 147 EP 157 DI 10.1093/imamat/58.2.147 PG 11 WC Mathematics, Applied SC Mathematics GA XA383 UT WOS:A1997XA38300004 ER PT J AU Miller, JA Walch, SP AF Miller, JA Walch, SP TI Prompt NO: Theoretical prediction of the high-temperature rate coefficient for CH+N-2->HCN+N SO INTERNATIONAL JOURNAL OF CHEMICAL KINETICS LA English DT Article ID NITROGEN-OXIDE FORMATION; REACTION CH(X2-PI)+N2(X1-SIGMA-G+)->HCN(X1-SIGMA+)+N(4S); NITRIC-OXIDE; MECHANISM; FLAMES; PRESSURE; DEPENDENCE; N-2 AB With potential-energy-surface parameters provided by Walch's calculations of the reaction path, we have calculated the thermal rate coefficient for the reaction, (R1) CH + N-2 <----> HCN + N. The theory employed assumes that the change in the reaction of the electron spin has little or no effect on the rate coefficient. The resulting expression for k(1), k(1) = 3.68 x 10(7) T-1.42 exp(-20723/RT) cm(3)/mole-sec., in the temperature range, 1000 K less than or equal to T less than or equal to 4000 K, is in remarkably good agreement with the limited amount of experimental data available, suggesting that the assumption is valid. The origins of the ''prompt-NO'' phenomenon, our analysis of reaction (RI), and comparison of the results with experiment are all discussed in detail. (C) 1997 John Wiley & Sons, Inc. C1 NASA,AMES RES CTR,THERMOSCI INST,MOFFETT FIELD,CA 94035. RP Miller, JA (reprint author), SANDIA NATL LABS,COMBUST RES FACIL,LIVERMORE,CA 94551, USA. NR 35 TC 39 Z9 40 U1 1 U2 2 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 1997 VL 29 IS 4 BP 253 EP 259 DI 10.1002/(SICI)1097-4601(1997)29:4<253::AID-KIN3>3.0.CO;2-T PG 7 WC Chemistry, Physical SC Chemistry GA WQ883 UT WOS:A1997WQ88300003 ER PT J AU Miller, JA Garrett, BC AF Miller, JA Garrett, BC TI Quantifying the non-RRKM effect in the H+O-2 reversible arrow OH+O reaction SO INTERNATIONAL JOURNAL OF CHEMICAL KINETICS LA English DT Article ID POTENTIAL-ENERGY SURFACES; TRANSITION-STATE THEORY; THERMAL RATE COEFFICIENT; CHEMICAL-REACTION RATES; MANY-BODY EXPANSION; QUASICLASSICAL TRAJECTORY CALCULATIONS; LONG-RANGE FORCES; REACTION H+O2->OH+O; RATE-CONSTANT; CROSS-SECTIONS AB In the present investigation the non-RRKM behavior in the title reaction is quantified in two different ways: (1) Quasiclassical trajectory calculations of the thermal rate coefficient are compared with results from a microcanonical variational transition-state theory/RRKM model. Results on both the Varandas DMBE IV and Melius-Blint potentials indicate that the non-RRKM behavior acts to reduce the thermal rate coefficient by about a factor of two, independent of temperature from 250 K to 5500 K. The QCT thermal rate coefficients on the two potentials are in remarkably good agreement with experiment and with each other over the entire temperature range. (2) The non-RRKM behavior as a classical phenomenon is demonstrated and quantified on both potentials by a direct test of the fundamental assumption. Complex-forming classical trajectories, started as either O + OH or H + O-2, are shown preferentially to return to the region of configuration space from which they were started. This test is discussed in detail in the text. The transition of the non-RRKM behavior from classical to quantum mechanics is also discussed. (C) 1997 John Wiley & Sons, Inc. C1 PACIFIC NW LAB, ENVIRONM MOL SCI LAB, RICHLAND, WA 99352 USA. RP Miller, JA (reprint author), SANDIA NATL LABS, COMBUST RES FACIL, LIVERMORE, CA 94551 USA. RI Garrett, Bruce/F-8516-2011 NR 62 TC 48 Z9 48 U1 1 U2 9 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 1997 VL 29 IS 4 BP 275 EP 287 DI 10.1002/(SICI)1097-4601(1997)29:4<275::AID-KIN6>3.0.CO;2-R PG 13 WC Chemistry, Physical SC Chemistry GA WQ883 UT WOS:A1997WQ88300006 ER PT J AU Cuevas, S Picologlou, BF Walker, JS Talmage, G AF Cuevas, S Picologlou, BF Walker, JS Talmage, G TI Liquid-metal mhd flow in rectangular ducts with thin conducting or insulating walls: Laminar and turbulent solutions SO INTERNATIONAL JOURNAL OF ENGINEERING SCIENCE LA English DT Article ID MAGNETOHYDRODYNAMIC FLOWS; MAGNETIC-FIELDS; BLANKETS AB This paper treats the steady, fully-developed flow of a liquid metal in a rectangular duct of constant cross-section with a uniform, transverse magnetic field. Thin conducting wall boundary conditions at the top/bottom walls (perpendicular to the magnetic field) are extended to allow electrical currents to return through either the wall or the Hartmann layers. Hence, a unified analysis of flows in ducts with wall conductance ratios in the range of interest of fusion blanket applications, namely, from thin conducting to insulating wall ducts, is conducted. The flow in laminar and turbulent regimes is investigated through a composite core-side-layer spectral collocation solution which explicitly resolves the flow in the side layers (parallel to the magnetic field) even for very large Hartmann numbers. Turbulent profiles are obtained through an iterative scheme in which turbulence is introduced through an eddy viscosity model from the renormalization group theory of turbulence [Yakhot, V. and Orsag, S. A., J. Sci. Comput., 1986, 1(1), 3]. The transition from a flow in a duct with thin conducting walls to one with insulating walls is clearly displayed by varying the wall conductance ratio from 0.05 to 0 for Hartmann numbers in the range 10(3)-10(5). In turbulent regime, Reynolds numbers vary in the range 5 x 10(4)-5 x 10(5). For thin conducting wall duct flows, turbulence is concentrated in the increased side layers while the core remains unperturbed. In insulating wall ducts, the flow remains in the laminar regime within the considered range of Reynolds numbers. (C) 1997 Elsevier Science Ltd. C1 ARGONNE NATL LAB,ARGONNE,IL 60439. UNIV ILLINOIS,DEPT MECH & IND ENGN,URBANA,IL 61801. PENN STATE UNIV,DEPT MECH ENGN,UNIVERSITY PK,PA 16802. RI Cuevas Garcia, Sergio /C-2138-2009 NR 20 TC 17 Z9 17 U1 0 U2 2 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0020-7225 J9 INT J ENG SCI JI Int. J. Eng. Sci. PD APR PY 1997 VL 35 IS 5 BP 485 EP 503 DI 10.1016/S0020-7225(96)00126-7 PG 19 WC Engineering, Multidisciplinary SC Engineering GA XD618 UT WOS:A1997XD61800004 ER PT J AU Cuevas, S Picologlou, BF Walker, JS Talmage, G Hua, TQ AF Cuevas, S Picologlou, BF Walker, JS Talmage, G Hua, TQ TI Heat transfer in laminar and turbulent liquid-metal MHD flows in square ducts with thin conducting or insulating walls SO INTERNATIONAL JOURNAL OF ENGINEERING SCIENCE LA English DT Article AB The heat transfer in fully-developed liquid-metal flows in a square duct with a uniform, transverse magnetic field is analyzed. Velocity profiles obtained for laminar; and turbulent regimes [Cuevas, S., Picologlou, B. F., Walker, J. S. and Talmage, G., Int. J. Engng Sci, 1997, 35, 485] are employed to solve the heat transfer equation through finite differences, in a duct with one side wall (parallel to the magnetic field) uniformly heated and three adiabatic walls. Turbulent effects are introduced through eddy viscous and thermal diffusivity models from the renormalization group theory of turbulence [Yakhot, V. and Orszag, S. A., J. Sci. Comput., 1986, 1(1), 3]. Analysis focuses in determining how the structure of the side-layer flow, influenced by the wall conductance ratio and Hartmann and Peclet numbers in the ranges of interest of fusion blanket applications, affects the heat transfer processes. Numerical calculations for liquid lithium show that for thin conducting wall duct cases, the laminar MI-ID heat transfer mechanism, characterized by high-velocity side-wall jets, appears to be more efficient than turbulent mixing in the boundary layer for a given Peclet number. (C) 1997 Elsevier Science Ltd. C1 ARGONNE NATL LAB,ARGONNE,IL 60439. UNIV ILLINOIS,DEPT MECH & IND ENGN,URBANA,IL 61801. PENN STATE UNIV,DEPT MECH ENGN,UNIVERSITY PK,PA 16802. RI Cuevas Garcia, Sergio /C-2138-2009 NR 13 TC 9 Z9 10 U1 0 U2 2 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0020-7225 J9 INT J ENG SCI JI Int. J. Eng. Sci. PD APR PY 1997 VL 35 IS 5 BP 505 EP 514 DI 10.1016/S0020-7225(96)00127-9 PG 10 WC Engineering, Multidisciplinary SC Engineering GA XD618 UT WOS:A1997XD61800005 ER PT J AU Badin, JS Tagore, S AF Badin, JS Tagore, S TI Energy pathway analysis - A hydrogen fuel cycle framework for system studies SO INTERNATIONAL JOURNAL OF HYDROGEN ENERGY LA English DT Article AB An analytical framework has been developed that can be used to estimate a range of life-cycle costs and impacts that result from the incremental production, storage, transport, and use of different fuels or energy carriers, such as hydrogen, electricity, natural gas, and gasoline. This information is used in a comparative analysis of energy pathways. The pathways provide the U.S. Department of Energy (DOE) with an indication of near-, mid-, and longterm technologies that have the greatest potential for advancement and can meet the cost goals. The methodology and conceptual issues are discussed. Also presented are results for selected pathways from the E3 (Energy, Economics, Emissions) Pathway Analysis Model. This model will be expanded to consider networks of pathways and to be compatible with a linear programming optimization processor. Scenarios and sets of constrains (energy demands, sources, emissions) will be defined so the effects on energy transformation activities included in the solution and on the total optimized system cost can be investigated. This evaluation will be used as a guide to eliminate technically feasible pathways if they are not cost effective or do not meet the threshold requirements for the market acceptance. (C) 1997 International Association for Hydrogen Energy. C1 US DOE,WASHINGTON,DC 20585. RP Badin, JS (reprint author), ENERGET INC,7164 GATEWAY DR,COLUMBIA,MD 21046, USA. NR 5 TC 8 Z9 8 U1 0 U2 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0360-3199 J9 INT J HYDROGEN ENERG JI Int. J. Hydrog. Energy PD APR PY 1997 VL 22 IS 4 BP 389 EP 395 DI 10.1016/S0360-3199(96)00097-3 PG 7 WC Chemistry, Physical; Electrochemistry; Energy & Fuels SC Chemistry; Electrochemistry; Energy & Fuels GA WL607 UT WOS:A1997WL60700005 ER PT J AU Onstott, EI AF Onstott, EI TI Cerium dioxide as a recycle reagent for thermochemical hydrogen production by splitting hydrochloric acid into the elements SO INTERNATIONAL JOURNAL OF HYDROGEN ENERGY LA English DT Article AB CeO2 (solid) reacts with HCl(g) at 383-625 K to yield CeOCl (solid, Cl-2(g) and H2O(g). After removal of Cl-2(g), at higher temperatures > 1050 K, the CeOCl (solid) then back-reacts with H2O(g) to yield H-2(g) and HCl(g). These two redox reactions selectively produce H-2 and Cl-2 in a two-step thermochemical cycle by splitting 2HCl(g) into H-2(g) + Cl-2(g). The solids remain in situ in the quartz reactor; only the gases need to be transported for separation of products and regeneration of solid reactant. Thermochemical calculations show the constraints for practical utilization of CeO2 as the recycle reagent. Cycle efficiency is much dependent on replacement of one oxide in CeO2 in the solid phase with one chloride, with the concomitant valence change at 383 K, and reversal at 1050-1270 K. (C) 1997 International Association for Hydrogen Energy. RP Onstott, EI (reprint author), LOS ALAMOS NATL LAB,DIV FOOD CHEM & TECHNOL,LOS ALAMOS,NM 87545, USA. NR 5 TC 4 Z9 4 U1 1 U2 3 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0360-3199 J9 INT J HYDROGEN ENERG JI Int. J. Hydrog. Energy PD APR PY 1997 VL 22 IS 4 BP 405 EP 408 DI 10.1016/S0360-3199(96)00090-0 PG 4 WC Chemistry, Physical; Electrochemistry; Energy & Fuels SC Chemistry; Electrochemistry; Energy & Fuels GA WL607 UT WOS:A1997WL60700007 ER PT J AU Xu, Y Keer, LM Luk, VK AF Xu, Y Keer, LM Luk, VK TI Elastic-cracked model for penetration into unreinforced concrete targets with ogival nose projectiles SO INTERNATIONAL JOURNAL OF SOLIDS AND STRUCTURES LA English DT Article AB In this research an elastic-cracked model for determining the forces on an ogival nose projectile is developed to estimate the resistance to penetration into an unreinforced concrete target. The model developed is guided by the post-test observation that concrete will crack in the region surrounding the projectile. In this model the spherical cavity expansion approximation is extended by assuming a cracked region and an elastic region to simulate penetration into an unreinforced concrete target. Thus, an elastic-cracked model is developed here for predicting the resistance to penetration, where it is assumed that the interface of the cracked region and elastic region, which satisfies the Hugoniot jump conditions, is controlled by the radial compressive strength p(0). Solutions that determine the boundary for the elastic region for both incompressible and compressible cases are given. A calculation shows that the incompressible solution is of first-order for the compressive solution when Poisson's ratio equals 0.5. The resistance to penetration depends on the following factors of the concrete target : Poisson's ratio v, locked volumetric strain eta*, strength of the material and velocity V. The present model predictions of depth of penetration appear to be in good agreement with existing experimental measurements that involve a steel projectile penetrating a thick, unreinforced concrete slab at normal incidence. (C) 1997 Elsevier Science Ltd. C1 SANDIA NATL LABS,ALBUQUERQUE,NM 87185. RP Xu, Y (reprint author), NORTHWESTERN UNIV,DEPT CIVIL ENGN,2145 SHERIDAN RD,EVANSTON,IL 60208, USA. RI Keer, Leon/B-7017-2009 NR 10 TC 11 Z9 14 U1 0 U2 9 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0020-7683 J9 INT J SOLIDS STRUCT JI Int. J. Solids Struct. PD APR PY 1997 VL 34 IS 12 BP 1479 EP 1491 DI 10.1016/S0020-7683(96)00099-6 PG 13 WC Mechanics SC Mechanics GA WP154 UT WOS:A1997WP15400004 ER PT J AU Xu, Y Keer, LM Luk, VK AF Xu, Y Keer, LM Luk, VK TI Stress properties at the tip of a conical notch SO INTERNATIONAL JOURNAL OF SOLIDS AND STRUCTURES LA English DT Article AB The singular behavior of a three-dimensional conical notch under torsional or torsionless loading was analyzed using the Papkovich-Neuber displacement potential method. Based on the analysis of the Legendre polynomial with complex index lambda(n) (Thompson, T. R. and Little, R. W. (1970). End effects in a truncated semi-infinite cone, Quart. J Mech. Appl. Math. 23, 185-196), transcendental equations to the stress order lambda(n) of a torsional or torsionless notch at the cone tip are given for various notch angles. Analytical solutions for stress distributions around the cone tip under a concentrated torque T, and around the line notch tip under an expansion source E, are derived using the Legendre polynomial expression. These solutions can be applied for the study of penetration or perforation, where a penetrator is simulated asa concentrated force and as an expansion source. Curves of the first order eigenvalues show that there exist very weak singular stresses at the three-dimensional conical notch. According to the evidence observed in the conical notch experiment (Williams, M. L. (1966). Stress singular, adhesion, and fracture. In Proc. 5th Nar. Congress for Appl. Mech. pp. 451-464), when the base of a cone is loaded, fracture occurs along its side instead of at its tip. This observation suggests that there may exist a comparatively weak singularity at the cone tip. (C) 1997 Elsevier Science Ltd. C1 SANDIA NATL LABS,ALBUQUERQUE,NM 87185. RP Xu, Y (reprint author), NORTHWESTERN UNIV,DEPT CIVIL ENGN,EVANSTON,IL 60208, USA. RI Keer, Leon/B-7017-2009 NR 7 TC 0 Z9 1 U1 1 U2 3 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0020-7683 J9 INT J SOLIDS STRUCT JI Int. J. Solids Struct. PD APR PY 1997 VL 34 IS 12 BP 1531 EP 1546 DI 10.1016/S0020-7683(96)00083-2 PG 16 WC Mechanics SC Mechanics GA WP154 UT WOS:A1997WP15400008 ER PT J AU Barrett, JW Galassi, M Miller, WA Sorkin, RD Tuckey, PA Williams, RM AF Barrett, JW Galassi, M Miller, WA Sorkin, RD Tuckey, PA Williams, RM TI Parallelizable implicit evolution scheme for Regge calculus SO INTERNATIONAL JOURNAL OF THEORETICAL PHYSICS LA English DT Article ID NULL-STRUT CALCULUS; SIMPLICIAL MINISUPERSPACE; EQUATIONS; TRIANGULATIONS; DYNAMICS; GRAVITY AB The role of Regge calculus as a tool for numerical relativity is discussed, and a parallelizable implicit evolution scheme described. Because of the structure of the Regge equations, it is possible to advance the vertices of a triangulated spacelike hypersurface in isolation, solving at each vertex a purely local system of implicit equations for the new edge lengths involved. (In particular, equations of global ''elliptic type'' do not arise.) Consequently, there exists a parallel evolution scheme which divides the vertices into families of nonadjacent elements and advances all the vertices of a family simultaneously. The relation between the structure of the equations of motion and the Bianchi identities is also considered. The method is illustrated by a preliminary application to a 600-cell Friedmann cosmology. The parallelizable evolution algorithm described in this paper should enable Regge calculus to be a viable discretization technique in numerical relativity. C1 LOS ALAMOS NATL LAB,DIV THEORET,LOS ALAMOS,NM 87545. LOS ALAMOS NATL LAB,SPACE DATA SYST GRP,LOS ALAMOS,NM 87545. SYRACUSE UNIV,DEPT PHYS,SYRACUSE,NY 13244. NATL AUTONOMOUS UNIV MEXICO,INST CIENCIAS NUCL,DEPT GRAVITAC & TEORIA CAMPOS,MEXICO CITY 04510,DF,MEXICO. UNIV FRANCHE COMTE,PHYS MOL LAB,F-25030 BESANCON,FRANCE. DAMTP,CAMBRIDGE CB3 9EW,ENGLAND. RP Barrett, JW (reprint author), UNIV NOTTINGHAM,DEPT MATH,UNIV PK,NOTTINGHAM NG7 2RD,ENGLAND. NR 45 TC 39 Z9 39 U1 0 U2 0 PU PLENUM PUBL CORP PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 SN 0020-7748 J9 INT J THEOR PHYS JI Int. J. Theor. Phys. PD APR PY 1997 VL 36 IS 4 BP 815 EP 839 DI 10.1007/BF02435787 PG 25 WC Physics, Multidisciplinary SC Physics GA WW834 UT WOS:A1997WW83400002 ER PT J AU Rose, JH AF Rose, JH TI Global minimum principle for one-dimensional inverse scattering with bound states SO INVERSE PROBLEMS LA English DT Letter AB Recently, a global minimum principle has been proposed for the one-dimensional inverse scattering problem for the Schrodinger equation on the real line and in the absence of bound states. In this letter, this restriction is removed and it is shown that the minimum principle, suitably generalized, holds for potentials with bound states. For each coordinate x, a functional of the reflection coefficient and a variational wavefield is defined. It is shown that the minimum of this functional yields the negative of the line integral of the potential on the interval {-infinity, x}. RP Rose, JH (reprint author), IOWA STATE UNIV SCI & TECHNOL,AMES LAB,AMES,IA 50011, USA. NR 10 TC 3 Z9 3 U1 0 U2 1 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL, ENGLAND BS1 6BE SN 0266-5611 J9 INVERSE PROBL JI Inverse Probl. PD APR PY 1997 VL 13 IS 2 BP L1 EP L5 DI 10.1088/0266-5611/13/2/001 PG 5 WC Mathematics, Applied; Physics, Mathematical SC Mathematics; Physics GA WW487 UT WOS:A1997WW48700001 ER PT J AU TerAkopian, GM Oganessian, YT Popeko, GS Daniel, AV Hamilton, JH Kormicki, J Ramayya, AV Ma, WC Babu, BRS Ginter, T Zhu, SJ Rasmussen, J Stoyer, M Li, LJ Ashtalos, S Chu, SJ Gregorich, KE Makiaveli, AO Mohar, MF Prussin, SG Kliman, J Morhac, M Cole, JD Aryaeinejad, R Dardenne, JK Driget, M AF TerAkopian, GM Oganessian, YT Popeko, GS Daniel, AV Hamilton, JH Kormicki, J Ramayya, AV Ma, WC Babu, BRS Ginter, T Zhu, SJ Rasmussen, J Stoyer, M Li, LJ Ashtalos, S Chu, SJ Gregorich, KE Makiaveli, AO Mohar, MF Prussin, SG Kliman, J Morhac, M Cole, JD Aryaeinejad, R Dardenne, JK Driget, M TI Yields of fragment pairs and characteristics of the Cf-252 spontaneous fission SO IZVESTIYA AKADEMII NAUK SERIYA FIZICHESKAYA LA Russian DT Article DE spontaneous fission of Cf-252; yield of fragment pairs; multiplicity of neutrons; isotope distribution of fragments C1 VANDERBILT UNIV, DEPT PHYS & ASTRON, NASHVILLE, TN 37235 USA. UNIV CALIF BERKELEY, LAWRENCE BERKELEY LAB, BERKELEY, CA 94720 USA. SLOVAK ACAD SCI, INST PHYS, BRATISLAVA, SLOVAKIA. IDAHO NATL ENGN LAB, IDAHO FALLS, ID 83415 USA. RP TerAkopian, GM (reprint author), DUBNA JOINT NUCL RES INST, DUBNA 141980, RUSSIA. NR 7 TC 0 Z9 0 U1 1 U2 1 PU MEZHDUNARODNAYA KNIGA PI MOSCOW PA 39 DIMITROVA UL., MOSCOW, 113095, RUSSIA SN 1026-3489 J9 IZV AKAD NAUK FIZ+ JI Izv. Akad. Nauk Ser. Fiz. PD APR PY 1997 VL 61 IS 4 BP 746 EP 751 PG 6 WC Physics, Multidisciplinary SC Physics GA XE146 UT WOS:A1997XE14600014 ER PT J AU Farges, F Brown, GE Rehr, JJ AF Farges, F Brown, GE Rehr, JJ TI Ti K-edge XANES studies of oxides: Theory vs. experiment SO JOURNAL DE PHYSIQUE IV LA English DT Article; Proceedings Paper CT 9th International Conference on X-Ray Absorption Fine Structure CY AUG 26-30, 1996 CL GRENOBLE, FRANCE SP European Synchrotron Radiat Facil, Ville Grenoble, Univ Joseph Fourier Grenoble, Minist Educ Natl, CNRS, CEA, Soc Francaise Chim, Jobin Yvon, Microcontrole, Eurisys Mesures, Inst Francais Petr, Air Liquide, Huber Diffrakt Teck, Haldor Topsoe A/S AB Ti K-edge x-ray absorption near edge structure (XANES) spectra for a variety of Ti(IV)-bearing crystalline oxide model compounds have been measured and compared to ab-initio multiple-scattering XANES calculations using the FEFF6 code. Depending on Ti-coordination (4, 5, or 6), the pre-edge features are found to vary in both position (by approximate to 2 +/- 0.1 eV) and normalized height (from approximate to 0.04 to approximate to 1.0), in agreement with the calculations. In compounds where the Ti-coordination is unknown (e.g., glasses and melts), both pre-edge position and height must be used to derive reliable coordination information for Ti. Use of both pre-edge parameters allows one to differentiate, for instance, between 100% of 5-coordinated Ti and a 50:50 mixture of 4-and 6-Ti. Finally, the intensity of the main-edge features can be used as a direct probe of disorder in the short-and medium-range environment of Ti, as exemplified by the comparison of the theoretical and measured XANES spectra obtained for several crystals and their amorphous analogs such as crystalline and radiation-damaged CaTiSiO5 and glassy and molten titanosilicates in the 4.5-1550 K range. C1 STANFORD UNIV,DEPT GEOL & ENVIRONM SCI,STANFORD,CA 94305. STANFORD UNIV,SSRL,STANFORD,CA 94305. UNIV WASHINGTON,DEPT PHYS,SEATTLE,WA 98195. LURE,ORSAY,FRANCE. RP Farges, F (reprint author), UNIV MARNE LA VALLEE,LAB PHYS & MECAN GEOMAT,F-93166 NOISY LE GRAND,FRANCE. NR 6 TC 5 Z9 5 U1 2 U2 4 PU EDITIONS PHYSIQUE PI LES ULIS CEDEX PA Z I DE COURTABOEUF AVE 7 AV DU HOGGAR, BP 112, 91944 LES ULIS CEDEX, FRANCE SN 1155-4339 J9 J PHYS IV JI J. Phys. IV PD APR PY 1997 VL 7 IS C2 BP 191 EP 193 PN 1 PG 3 WC Physics, Multidisciplinary SC Physics GA XQ951 UT WOS:A1997XQ95100040 ER PT J AU Wasserman, SR AF Wasserman, SR TI The analysis of mixtures: Application of principal component analysis to XAS spectra SO JOURNAL DE PHYSIQUE IV LA English DT Article; Proceedings Paper CT 9th International Conference on X-Ray Absorption Fine Structure CY AUG 26-30, 1996 CL GRENOBLE, FRANCE SP European Synchrotron Radiat Facil, Ville Grenoble, Univ Joseph Fourier Grenoble, Minist Educ Natl, CNRS, CEA, Soc Francaise Chim, Jobin Yvon, Microcontrole, Eurisys Mesures, Inst Francais Petr, Air Liquide, Huber Diffrakt Teck, Haldor Topsoe A/S AB Many samples which are subjected to XAS analysis contain the element of interest in more than one chemical form. The interpretation of the spectra from such samples is often not straightforward, particularly if appropriate model systems are not available. We have applied principal component analysis (PCA) to real and simulated systems which contain mixtures of several species for a given element PCA has been extensively used for the analysis of other types of spectra, including MS, IR, and UV-VIS, The application of PCA to XAS is illustrated by examining the speciation of iron within coals. PCA can determine how many different species that contain a particular element are present in a series of spectra. In tandem with model compounds, principal component analysis can suggest which of the models may contribute to the observed XAS spectra. RP Wasserman, SR (reprint author), ARGONNE NATL LAB,DIV CHEM,9700 S CASS AVE,ARGONNE,IL 60439, USA. NR 3 TC 63 Z9 63 U1 0 U2 17 PU EDITIONS PHYSIQUE PI LES ULIS CEDEX PA Z I DE COURTABOEUF AVE 7 AV DU HOGGAR, BP 112, 91944 LES ULIS CEDEX, FRANCE SN 1155-4339 J9 J PHYS IV JI J. Phys. IV PD APR PY 1997 VL 7 IS C2 BP 203 EP 205 PN 1 PG 3 WC Physics, Multidisciplinary SC Physics GA XQ951 UT WOS:A1997XQ95100043 ER PT J AU Heald, SM Brewe, DL Barg, B Kim, KH Brown, FC Stern, EA AF Heald, SM Brewe, DL Barg, B Kim, KH Brown, FC Stern, EA TI Micro-XAS using tapered capillary concentrating optics SO JOURNAL DE PHYSIQUE IV LA English DT Article; Proceedings Paper CT 9th International Conference on X-Ray Absorption Fine Structure CY AUG 26-30, 1996 CL GRENOBLE, FRANCE SP European Synchrotron Radiat Facil, Ville Grenoble, Univ Joseph Fourier Grenoble, Minist Educ Natl, CNRS, CEA, Soc Francaise Chim, Jobin Yvon, Microcontrole, Eurisys Mesures, Inst Francais Petr, Air Liquide, Huber Diffrakt Teck, Haldor Topsoe A/S ID RAY AB Tapered capillary optics are a promising choice for producing micro-beams at third generation sources. The reproducible energy dependence of their X-ray transmission, and fixed output beam position make them well suited for micro-XAS applications. Fiber optics techniques have been developed to produce long (1 m) capillaries which provide a good match to the low divergence undulator beams at third generation sources. The results of X-ray tests made at the NSLS indicate the performance of many of the capillaries closely match theoretical values. Currently these provide a monochromatic beam of about 10(6) ph/sec/mu m(2) at an unfocused bending magnet beamline. High quality X-ray images and micro-XAFS have been obtained at the NSLS with better than 3 mu m resolution. The same capillaries should provide more than 10(10)ph/sec/mu m(2) at an APS undulator, indicating that sub-mu m XAS is possible. C1 UNIV WASHINGTON,DEPT PHYS,SEATTLE,WA 98195. RP Heald, SM (reprint author), PACIFIC NW NATL LAB,ARGONNE NATL LAB,APS BLDG 435E,9700 S CASS AVE,ARGONNE,IL 60439, USA. NR 8 TC 3 Z9 3 U1 0 U2 0 PU EDITIONS PHYSIQUE PI LES ULIS CEDEX PA Z I DE COURTABOEUF AVE 7 AV DU HOGGAR, BP 112, 91944 LES ULIS CEDEX, FRANCE SN 1155-4339 J9 J PHYS IV JI J. Phys. IV PD APR PY 1997 VL 7 IS C2 BP 297 EP 301 PN 1 PG 5 WC Physics, Multidisciplinary SC Physics GA XQ951 UT WOS:A1997XQ95100085 ER PT J AU Rowen, M Wong, J Tanaka, T AF Rowen, M Wong, J Tanaka, T TI Suppression of positive glitches in the transmission function of YB66 monochromator SO JOURNAL DE PHYSIQUE IV LA English DT Article; Proceedings Paper CT 9th International Conference on X-Ray Absorption Fine Structure CY AUG 26-30, 1996 CL GRENOBLE, FRANCE SP European Synchrotron Radiat Facil, Ville Grenoble, Univ Joseph Fourier Grenoble, Minist Educ Natl, CNRS, CEA, Soc Francaise Chim, Jobin Yvon, Microcontrole, Eurisys Mesures, Inst Francais Petr, Air Liquide, Huber Diffrakt Teck, Haldor Topsoe A/S ID REGION AB The results of using a SiC cutoff mirror to suppress two observed positive glitches just above the Mg K absorption edge in the transmission function of YB66 monochromator are reported here. C1 LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94551. NATL INST RES INORGAN MAT,TSUKUBA,IBARAKI 305,JAPAN. RP Rowen, M (reprint author), STANFORD SYNCHROTRON RADIAT LAB,POB 4349,STANFORD,CA 94309, USA. NR 5 TC 0 Z9 0 U1 0 U2 1 PU EDITIONS PHYSIQUE PI LES ULIS CEDEX PA Z I DE COURTABOEUF AVE 7 AV DU HOGGAR, BP 112, 91944 LES ULIS CEDEX, FRANCE SN 1155-4339 J9 J PHYS IV JI J. Phys. IV PD APR PY 1997 VL 7 IS C2 BP 315 EP 315 PN 1 PG 1 WC Physics, Multidisciplinary SC Physics GA XQ951 UT WOS:A1997XQ95100088 ER PT J AU Furenlid, LR Mayer, AJ Kirkland, JP AF Furenlid, LR Mayer, AJ Kirkland, JP TI NSLS-DAC: A beamline control and data acquisition package SO JOURNAL DE PHYSIQUE IV LA English DT Article; Proceedings Paper CT 9th International Conference on X-Ray Absorption Fine Structure CY AUG 26-30, 1996 CL GRENOBLE, FRANCE SP European Synchrotron Radiat Facil, Ville Grenoble, Univ Joseph Fourier Grenoble, Minist Educ Natl, CNRS, CEA, Soc Francaise Chim, Jobin Yvon, Microcontrole, Eurisys Mesures, Inst Francais Petr, Air Liquide, Huber Diffrakt Teck, Haldor Topsoe A/S AB A LabVIEW(TM)-based software package has been developed to control beamlines and acquire data during energy, motor, voltage, and time scans. Though geared for spectroscopy, the software implements a complete set of teals for operating and monitoring beamline instrumentation. The package presents a graphical interface to the user that is easy to learn for novices, yet highly efficient for experienced researchers. The main code is beamline and hardware independent. Lower level data acquisition drivers have been written for CAMAC and GPIB-based instrumentation. All beamline specific features, such as monochromator control, are contained in a single plug-in library. Users wishing to extend the program's capabilities can add customized scan types (such as DAFS) via a run-time link to external routines. C1 NEW MEXICO INST MIN & TECHNOL,ALBUQUERQUE,NM 87153. SFA INC,LARGO,MD 20774. RP Furenlid, LR (reprint author), BROOKHAVEN NATL LAB,NATL SYNCHROTRON LIGHT SOURCE DEPT,UPTON,NY 11973, USA. NR 0 TC 2 Z9 2 U1 0 U2 0 PU EDITIONS PHYSIQUE PI LES ULIS CEDEX PA Z I DE COURTABOEUF AVE 7 AV DU HOGGAR, BP 112, 91944 LES ULIS CEDEX, FRANCE SN 1155-4339 J9 J PHYS IV JI J. Phys. IV PD APR PY 1997 VL 7 IS C2 BP 335 EP 336 PN 1 PG 2 WC Physics, Multidisciplinary SC Physics GA XQ951 UT WOS:A1997XQ95100098 ER PT J AU Wang, X Cramer, SP AF Wang, X Cramer, SP TI Spin-polarized EXAFS using K beta detection SO JOURNAL DE PHYSIQUE IV LA English DT Article; Proceedings Paper CT 9th International Conference on X-Ray Absorption Fine Structure CY AUG 26-30, 1996 CL GRENOBLE, FRANCE SP European Synchrotron Radiat Facil, Ville Grenoble, Univ Joseph Fourier Grenoble, Minist Educ Natl, CNRS, CEA, Soc Francaise Chim, Jobin Yvon, Microcontrole, Eurisys Mesures, Inst Francais Petr, Air Liquide, Huber Diffrakt Teck, Haldor Topsoe A/S ID X-RAY-ABSORPTION; FLUORESCENCE; SPECTROSCOPY AB The first spin-polarized EXAFS of an anti-ferromagnetically coupled system using K beta detection is reported. The K beta SPEXAFS effect is much larger than the K-edge XMCD SPEXAFS, because of the greater spin polarization of the excited photoelectrons. This internally referenced technique is suited for antiferromagnetically coupled systems, as well as ferromagnetic and paramagnetic systems. C1 LAWRENCE BERKELEY LAB,BERKELEY,CA 95720. RP Wang, X (reprint author), UNIV CALIF DAVIS,DEPT APPL SCI,DAVIS,CA 95616, USA. NR 14 TC 4 Z9 4 U1 1 U2 1 PU EDITIONS PHYSIQUE PI LES ULIS CEDEX PA Z I DE COURTABOEUF AVE 7 AV DU HOGGAR, BP 112, 91944 LES ULIS CEDEX, FRANCE SN 1155-4339 J9 J PHYS IV JI J. Phys. IV PD APR PY 1997 VL 7 IS C2 BP 361 EP 363 PN 1 PG 3 WC Physics, Multidisciplinary SC Physics GA XQ951 UT WOS:A1997XQ95100107 ER PT J AU Gofron, KJ Kimball, CW Lee, PL Jennings, G Montano, PA AF Gofron, KJ Kimball, CW Lee, PL Jennings, G Montano, PA TI K absorption edge Magnetic Circular-X-ray Dichroism of Fe-Ni alloys SO JOURNAL DE PHYSIQUE IV LA English DT Article; Proceedings Paper CT 9th International Conference on X-Ray Absorption Fine Structure CY AUG 26-30, 1996 CL GRENOBLE, FRANCE SP European Synchrotron Radiat Facil, Ville Grenoble, Univ Joseph Fourier Grenoble, Minist Educ Natl, CNRS, CEA, Soc Francaise Chim, Jobin Yvon, Microcontrole, Eurisys Mesures, Inst Francais Petr, Air Liquide, Huber Diffrakt Teck, Haldor Topsoe A/S AB We report Magnetic Circular X-ray Dichroism (MCXD) measurements in Fe-Ni alloys. We used an energy dispersive beamline in our measurements. A polychromator spectrum contains self reference both in intensity and energy since all energies are measured at the same time and remain stable during an energy scan since no movement of the X-ray optics is necessary. We measured the K absorption edges in Fe and Ni (s - p electronic states) in the d ferromagnetic alloys of Fe-Ni. We observe that the signal at the invar composition is of comparable strengh as other compositions in contrast to previous studies. We used cold rolled (disordered) foils instead of powders. The measurements reveal changes of the MCXD signal with composition and crystal structure. C1 NO ILLINOIS UNIV,DEPT PHYS,DE KALB,IL 60115. UNIV ILLINOIS,DEPT PHYS,CHICAGO,IL 60680. RP Gofron, KJ (reprint author), ARGONNE NATL LAB,DIV MAT SCI,9700 S CASS AVE,ARGONNE,IL 60439, USA. NR 10 TC 2 Z9 2 U1 0 U2 0 PU EDITIONS PHYSIQUE PI LES ULIS CEDEX PA Z I DE COURTABOEUF AVE 7 AV DU HOGGAR, BP 112, 91944 LES ULIS CEDEX, FRANCE SN 1155-4339 J9 J PHYS IV JI J. Phys. IV PD APR PY 1997 VL 7 IS C2 BP 421 EP 424 PN 1 PG 4 WC Physics, Multidisciplinary SC Physics GA XQ951 UT WOS:A1997XQ95100121 ER PT J AU Wong, J Froba, M Tamura, E Rowen, M Rek, Z Tanaka, T AF Wong, J Froba, M Tamura, E Rowen, M Rek, Z Tanaka, T TI Progress in 1-2 KeV spectroscopy using a YB66 monochromator SO JOURNAL DE PHYSIQUE IV LA English DT Article; Proceedings Paper CT 9th International Conference on X-Ray Absorption Fine Structure CY AUG 26-30, 1996 CL GRENOBLE, FRANCE SP European Synchrotron Radiat Facil, Ville Grenoble, Univ Joseph Fourier Grenoble, Minist Educ Natl, CNRS, CEA, Soc Francaise Chim, Jobin Yvon, Microcontrole, Eurisys Mesures, Inst Francais Petr, Air Liquide, Huber Diffrakt Teck, Haldor Topsoe A/S AB This report summarizes XAFS investigations, particularly in the XANES region, performed to date on a variety of materials containing Si, Al and Mg using a double-crystal YB66 monochromator in the 1-2 keV region. C1 UNIV HAMBURG,INST INORGAN & APPL CHEM,D-20146 HAMBURG,GERMANY. STANFORD SYNCHROTRON RADIAT LAB,STANFORD,CA 94309. NATL INST RES INORGAN MAT,TSUKUBA,IBARAKI 305,JAPAN. RP Wong, J (reprint author), LAWRENCE LIVERMORE NATL LAB,POB 808,LIVERMORE,CA 94551, USA. RI Froba, Michael/B-2888-2010 NR 7 TC 0 Z9 0 U1 0 U2 2 PU EDITIONS PHYSIQUE PI LES ULIS CEDEX PA Z I DE COURTABOEUF AVE 7 AV DU HOGGAR, BP 112, 91944 LES ULIS CEDEX, FRANCE SN 1155-4339 J9 J PHYS IV JI J. Phys. IV PD APR PY 1997 VL 7 IS C2 BP 511 EP 512 PN 1 PG 2 WC Physics, Multidisciplinary SC Physics GA XQ951 UT WOS:A1997XQ95100158 ER PT J AU Chen, LX Wasielewski, MR Rajh, T Lee, PL Thurnauer, MC Montano, PA AF Chen, LX Wasielewski, MR Rajh, T Lee, PL Thurnauer, MC Montano, PA TI Molecular structure determination for photogenerated intermediates in photoinduced electron transfer reactions using steady-state and transient XAFS SO JOURNAL DE PHYSIQUE IV LA English DT Article; Proceedings Paper CT 9th International Conference on X-Ray Absorption Fine Structure CY AUG 26-30, 1996 CL GRENOBLE, FRANCE SP European Synchrotron Radiat Facil, Ville Grenoble, Univ Joseph Fourier Grenoble, Minist Educ Natl, CNRS, CEA, Soc Francaise Chim, Jobin Yvon, Microcontrole, Eurisys Mesures, Inst Francais Petr, Air Liquide, Huber Diffrakt Teck, Haldor Topsoe A/S ID X-RAY-ABSORPTION AB Many photoinduced electron transfer reactions are accompanied by nuclear rearrangements of the molecules involved. In order to understand the reactivities of the molecules and the reaction mechanisms, precise information on the molecular structural changes accompanying the electron transfer is often required. We present here conventional XAFS and transient energy dispersive XAFS studies on (1) the structures of excited and photoinduced charge separated states of porphyrin and porphyrin based supermolecules, and (2) structures of TiO2 colloid and the heavy metal ions that bind to the colloid surfaces during photocatalytic reductions. C1 ARGONNE NATL LAB,DIV SCI MAT,ARGONNE,IL 60439. RP Chen, LX (reprint author), ARGONNE NATL LAB,DIV CHEM,9700 S CASS AVE,ARGONNE,IL 60439, USA. NR 10 TC 2 Z9 2 U1 0 U2 1 PU EDITIONS PHYSIQUE PI LES ULIS CEDEX PA Z I DE COURTABOEUF AVE 7 AV DU HOGGAR, BP 112, 91944 LES ULIS CEDEX, FRANCE SN 1155-4339 J9 J PHYS IV JI J. Phys. IV PD APR PY 1997 VL 7 IS C2 BP 569 EP 572 PN 1 PG 4 WC Physics, Multidisciplinary SC Physics GA XQ951 UT WOS:A1997XQ95100180 ER PT J AU Denecke, MA Reich, T Pompe, S Bubner, M Heise, KH Nitsche, H Allen, PG Bucher, JJ Edelstein, NM Shuh, DK AF Denecke, MA Reich, T Pompe, S Bubner, M Heise, KH Nitsche, H Allen, PG Bucher, JJ Edelstein, NM Shuh, DK TI Differentiating between monodentate and bidentate carboxylate ligands coordinated to uranyl ions using EXAFS SO JOURNAL DE PHYSIQUE IV LA English DT Article; Proceedings Paper CT 9th International Conference on X-Ray Absorption Fine Structure CY AUG 26-30, 1996 CL GRENOBLE, FRANCE SP European Synchrotron Radiat Facil, Ville Grenoble, Univ Joseph Fourier Grenoble, Minist Educ Natl, CNRS, CEA, Soc Francaise Chim, Jobin Yvon, Microcontrole, Eurisys Mesures, Inst Francais Petr, Air Liquide, Huber Diffrakt Teck, Haldor Topsoe A/S AB We have investigated the U L-III-edge EXAFS of two carboxylato uranyl complexes of known structure to explore the possibilty of differentiating between monodentate and bidentate coordinated carboxylate ions. The interpretation of EXAFS results from uranyl complexes with carboxylate ions based solely on axial and equatorial bond lengths can be inconclusive; information from further-distant shells is often needed. Multiple scattering (MS) pathways along the O=U=O unit and in coordinating chelating or monodentate carboxylate groups can make substantial contributions to the EXAFS. Therefore, MS pathways were calculated using FEFF6 [1] and considered in the data analysis. EXAFS results are compared to XRD data reported in the literature. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV CHEM SCI,BERKELEY,CA 94720. RP Denecke, MA (reprint author), ROSSENDORF INC,FORSCHUNGSZENTRUM ROSSENDORF EV,INST RADIOCHEM,POSTFACH 510119,D-01314 DRESDEN,GERMANY. RI Reich, Tobias/C-7064-2016 OI Reich, Tobias/0000-0002-5600-3951 NR 6 TC 27 Z9 28 U1 0 U2 10 PU EDITIONS PHYSIQUE PI LES ULIS CEDEX PA Z I DE COURTABOEUF AVE 7 AV DU HOGGAR, BP 112, 91944 LES ULIS CEDEX, FRANCE SN 1155-4339 J9 J PHYS IV JI J. Phys. IV PD APR PY 1997 VL 7 IS C2 BP 637 EP 638 PN 1 PG 2 WC Physics, Multidisciplinary SC Physics GA XQ951 UT WOS:A1997XQ95100204 ER PT J AU Renner, MW Furenlid, LR Barkigia, KM Fajer, J AF Renner, MW Furenlid, LR Barkigia, KM Fajer, J TI XAFS and crystallographic studies of Ni(II) porphyrins in single crystals and solution SO JOURNAL DE PHYSIQUE IV LA English DT Article; Proceedings Paper CT 9th International Conference on X-Ray Absorption Fine Structure CY AUG 26-30, 1996 CL GRENOBLE, FRANCE SP European Synchrotron Radiat Facil, Ville Grenoble, Univ Joseph Fourier Grenoble, Minist Educ Natl, CNRS, CEA, Soc Francaise Chim, Jobin Yvon, Microcontrole, Eurisys Mesures, Inst Francais Petr, Air Liquide, Huber Diffrakt Teck, Haldor Topsoe A/S ID SPECTROSCOPY; COMPLEXES AB Nickel porphyrins serve as models for the active sites of several biological processes. Crystallographic and EXAFS results for a Ni meso-tetrapropyl porphyrin (NiTPrP) yield different Ni-N distances in solution and in the solid state. The Ni-N distances determined by single crystal polarized XAS and X-ray diffraction agree well. Polarized XANES experiments further establish that the pre-edge feature observed in square planar Ni(II) complexes is a 1s-4pz transition. The single crystal and solution EXAFS results demonstrate that conformational variations of the porphyrin macrocycle can readily be imposed by environmental and/or packing forces and can thereby modulate the chemical and physical properties of porphyrinic chromophores and prosthetic groups. RP Renner, MW (reprint author), BROOKHAVEN NATL LAB,DEPT APPL SCI,UPTON,NY 11973, USA. NR 6 TC 11 Z9 11 U1 0 U2 3 PU EDITIONS PHYSIQUE PI LES ULIS CEDEX PA Z I DE COURTABOEUF AVE 7 AV DU HOGGAR, BP 112, 91944 LES ULIS CEDEX, FRANCE SN 1155-4339 J9 J PHYS IV JI J. Phys. IV PD APR PY 1997 VL 7 IS C2 BP 661 EP 662 PN 1 PG 2 WC Physics, Multidisciplinary SC Physics GA XQ951 UT WOS:A1997XQ95100216 ER PT J AU Cross, JO Newville, M Sorensen, LB Stragier, HJ Bouldin, CE Woicik, JC AF Cross, JO Newville, M Sorensen, LB Stragier, HJ Bouldin, CE Woicik, JC TI Separated anomalous scattering amplitudes for the inequivalent Cu sites in YBa2Cu3O7-delta using DAFS SO JOURNAL DE PHYSIQUE IV LA English DT Article; Proceedings Paper CT 9th International Conference on X-Ray Absorption Fine Structure CY AUG 26-30, 1996 CL GRENOBLE, FRANCE SP European Synchrotron Radiat Facil, Ville Grenoble, Univ Joseph Fourier Grenoble, Minist Educ Natl, CNRS, CEA, Soc Francaise Chim, Jobin Yvon, Microcontrole, Eurisys Mesures, Inst Francais Petr, Air Liquide, Huber Diffrakt Teck, Haldor Topsoe A/S ID DIFFRACTION AB The separate complex resonant scattering amplitudes for the two inequivalent Cu sites in YBa2Cu3O7-delta have been determined using diffraction anomalous fine structure (DAFS). The combined amplitudes Delta f(Q,E) for eight specular (00l) reflections were isolated from the measured intensity using the iterative dispersion algorithm of Pickering, et al., modified to accommodate contributions to the imaginary part of the scattering amplitude from the heavy Ba and Y atoms. The individual site response functions f ''(E) were solved by singular value decomposition of the matrix of crystallographic coefficients and applying the inverse matrix to Delta f(Q,E) at each value of energy. For comparison, a second set of coefficients was obtained by simultaneously fitting the DAFS fine structure functions chi(Q, k) using the computer program FEFFIT under a set of constraints. The chi(Q, k) were modeled as linear combinations of the two Cu site chi(k) functions using a kinematic structure factor model with Q as the independent variable and theoretical chi(k) from FEFF7. C1 LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550. UNIV WASHINGTON,DEPT PHYS,SEATTLE,WA 98195. NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899. RP Cross, JO (reprint author), USN,RES LAB,WASHINGTON,DC 20375, USA. NR 7 TC 9 Z9 9 U1 0 U2 3 PU EDITIONS PHYSIQUE PI LES ULIS CEDEX PA Z I DE COURTABOEUF AVE 7 AV DU HOGGAR, BP 112, 91944 LES ULIS CEDEX, FRANCE SN 1155-4339 J9 J PHYS IV JI J. Phys. IV PD APR PY 1997 VL 7 IS C2 BP 745 EP 747 DI 10.1051/jp4:1997224 PN 2 PG 3 WC Physics, Multidisciplinary SC Physics GA XQ952 UT WOS:A1997XQ95200025 ER PT J AU Newville, M Cross, JO Ravel, B Sorensen, LB Bouldin, CE Yacoby, Y AF Newville, M Cross, JO Ravel, B Sorensen, LB Bouldin, CE Yacoby, Y TI Co-refinement of diffraction anomalous fine-structure data SO JOURNAL DE PHYSIQUE IV LA English DT Article; Proceedings Paper CT 9th International Conference on X-Ray Absorption Fine Structure CY AUG 26-30, 1996 CL GRENOBLE, FRANCE SP European Synchrotron Radiat Facil, Ville Grenoble, Univ Joseph Fourier Grenoble, Minist Educ Natl, CNRS, CEA, Soc Francaise Chim, Jobin Yvon, Microcontrole, Eurisys Mesures, Inst Francais Petr, Air Liquide, Huber Diffrakt Teck, Haldor Topsoe A/S AB Diffraction Anomalous Fine-Structure (DAFS) combines the sensitivity to long-range-order of diffraction with the short-range-order sensitivity of XAFS. This makes it possible to use a set of DAFS measured intensities to simultaneously refine both long-and short-range structural parameters, while maintaining some constraints between them. This method combines a calculation of the structure factor based on the unit cell of the crystal with a calculation of the fine-structure chi(E) around each resonant site. Tabulated values of the scattering amplitude are used away from the resonant energies, while the near-edge anomalous scattering amplitude is calculated for the resonant sites using a differential Kramers-Kronig transform of an embedded atom absorption coefficient mu(0)(E) from FEFF. We discuss some of the subtleties of this approach to DAFS analysis. C1 USN,RES LAB,WASHINGTON,DC 20375. UNIV WASHINGTON,DEPT PHYS,SEATTLE,WA 98195. NIST,GAITHERSBURG,MD 20899. HEBREW UNIV JERUSALEM,RACAH INST PHYS,IL-91904 JERUSALEM,ISRAEL. RP Newville, M (reprint author), LAWRENCE LIVERMORE NATL LAB,L-219,LIVERMORE,CA 94550, USA. NR 4 TC 2 Z9 2 U1 0 U2 6 PU EDITIONS PHYSIQUE PI LES ULIS CEDEX PA Z I DE COURTABOEUF AVE 7 AV DU HOGGAR, BP 112, 91944 LES ULIS CEDEX, FRANCE SN 1155-4339 J9 J PHYS IV JI J. Phys. IV PD APR PY 1997 VL 7 IS C2 BP 759 EP 760 DI 10.1051/jp4:1997228 PN 2 PG 2 WC Physics, Multidisciplinary SC Physics GA XQ952 UT WOS:A1997XQ95200029 ER PT J AU Hunter, DB Bertsch, PM Kemner, KM Clark, SB AF Hunter, DB Bertsch, PM Kemner, KM Clark, SB TI Distribution and chemical speciation of metals and metalloids in biota collected from contaminated environments by spatially resolved XRF, XANES, and EXAFS SO JOURNAL DE PHYSIQUE IV LA English DT Article; Proceedings Paper CT 9th International Conference on X-Ray Absorption Fine Structure CY AUG 26-30, 1996 CL GRENOBLE, FRANCE SP European Synchrotron Radiat Facil, Ville Grenoble, Univ Joseph Fourier Grenoble, Minist Educ Natl, CNRS, CEA, Soc Francaise Chim, Jobin Yvon, Microcontrole, Eurisys Mesures, Inst Francais Petr, Air Liquide, Huber Diffrakt Teck, Haldor Topsoe A/S ID ABSORPTION AB Shell fragments from turtles collected in a wetland receiving outfall from coal combustion ash basins were elevated in a number of contaminants, notably Se and As. Micro-XANES analysis of the epithelial layer on the shell and of the bone tissue revealed that the keratin associated Se was present exclusively in seleno-amino acid coordination environments, whereas Se in the bone tissue was a mixture of selenate and proteinaceous Se, Elemental distribution maps of hyperaccumulating plants generated by XRF reveal a heterogeneous distribution of Se and Cr, with Se being concentrated within the nuclei of cells and Cr within discrete aggregates in the cytoplasm. Micro-XANES measurements taken on these same regions demonstrated the total loss of the Cr(VI) diagnostic pre-edge feature, indicating the complete reduction of the Cr(VI) to Cr(III) after uptake by the plants. C1 USN,RES LAB,WASHINGTON,DC 20375. RP Hunter, DB (reprint author), UNIV GEORGIA,ADV ANALYT CTR ENVIRONM SCI,SREL,DRAWER E,AIKEN,SC 29802, USA. NR 4 TC 14 Z9 14 U1 1 U2 4 PU EDITIONS PHYSIQUE PI LES ULIS CEDEX PA Z I DE COURTABOEUF AVE 7 AV DU HOGGAR, BP 112, 91944 LES ULIS CEDEX, FRANCE SN 1155-4339 J9 J PHYS IV JI J. Phys. IV PD APR PY 1997 VL 7 IS C2 BP 767 EP 771 DI 10.1051/jp4:1997232 PN 2 PG 5 WC Physics, Multidisciplinary SC Physics GA XQ952 UT WOS:A1997XQ95200033 ER PT J AU Scheidegger, AM Lamble, GM Sparks, DL AF Scheidegger, AM Lamble, GM Sparks, DL TI The kinetics of nickel sorption on pyrophyllite as monitored by x-ray absorption fine structure (XAFS) spectroscopy SO JOURNAL DE PHYSIQUE IV LA English DT Article; Proceedings Paper CT 9th International Conference on X-Ray Absorption Fine Structure CY AUG 26-30, 1996 CL GRENOBLE, FRANCE SP European Synchrotron Radiat Facil, Ville Grenoble, Univ Joseph Fourier Grenoble, Minist Educ Natl, CNRS, CEA, Soc Francaise Chim, Jobin Yvon, Microcontrole, Eurisys Mesures, Inst Francais Petr, Air Liquide, Huber Diffrakt Teck, Haldor Topsoe A/S AB This study investigated the effect of reaction time (minutes to months) on the surface coordination environment of Ni sorbed onto pyrophyllite using XAFS. The data suggest the appearance of multinuclear Ni complexes after a reaction time of minutes. As reaction time progresses, these multinuclear Ni complexes increased in size ((NNi-Ni = 1.4-4.5). Ni-Ni bond distances (2.99-3.03 Angstrom) were similar to those for mixed Ni-Al hydroxides (3.03 Angstrom), but distinctively shorter than those for Ni(OH)(2)(s) (3.09 Angstrom). We propose that the formation of mixed Ni-Al hydroxides may explain the observed bond distances and coordination numbers. C1 BROOKHAVEN NATL LAB,UPTON,NY 11971. RP Scheidegger, AM (reprint author), UNIV DELAWARE,DEPT PLANT & SOIL SCI,NEWARK,DE 19717, USA. NR 9 TC 9 Z9 9 U1 0 U2 1 PU EDITIONS PHYSIQUE PI LES ULIS CEDEX PA Z I DE COURTABOEUF AVE 7 AV DU HOGGAR, BP 112, 91944 LES ULIS CEDEX, FRANCE SN 1155-4339 J9 J PHYS IV JI J. Phys. IV PD APR PY 1997 VL 7 IS C2 BP 773 EP 775 DI 10.1051/jp4:1997233 PN 2 PG 3 WC Physics, Multidisciplinary SC Physics GA XQ952 UT WOS:A1997XQ95200034 ER PT J AU Kemner, KM Hunter, DB Bertsch, PM Kirkland, JP Elam, WT AF Kemner, KM Hunter, DB Bertsch, PM Kirkland, JP Elam, WT TI Determination of site specific binding environments of surface sorbed cesium on clay minerals by Cs-EXAFS SO JOURNAL DE PHYSIQUE IV LA English DT Article; Proceedings Paper CT 9th International Conference on X-Ray Absorption Fine Structure CY AUG 26-30, 1996 CL GRENOBLE, FRANCE SP European Synchrotron Radiat Facil, Ville Grenoble, Univ Joseph Fourier Grenoble, Minist Educ Natl, CNRS, CEA, Soc Francaise Chim, Jobin Yvon, Microcontrole, Eurisys Mesures, Inst Francais Petr, Air Liquide, Huber Diffrakt Teck, Haldor Topsoe A/S AB Transport behavior of Cs-137 in the environment is regulated by surface sorption reactions on clay mineral surfaces. To provide greater understanding of Cs transport processes, XAFS investigations of the local environments of Cs-133 sorbed to clay minerals were conducted on Cs-Ca exchanged clay suspensions at the Cs Lm-edge. With decreased surface loadings of Cs, the Cs local environment exhibited increased long range order beyond 6 Angstrom. Identification of Cs in expanded, semi-collapsed and collapsed interlayer environments was determined by correlating radial distances and Fourier transform peak amplitudes representing Cs-O and Cs-Al/Si in the octahedral and tetrahedral layers. Despite the difficulties of analyzing XAFS data of adsorbed atoms in multiple environments, isolation of Cs in more specific sites by selective exchange should allow detailed analysis and identification of predominant binding environments of cations to clay surfaces. C1 UNIV GEORGIA,SAVANNAH RIVER ECOL LAB,ADV ANALYT CTR ENVIRONM SCI,AIKEN,SC. SFA INC,LANDOVER,MD 20785. USN,RES LAB,WASHINGTON,DC 20375. NR 4 TC 12 Z9 12 U1 1 U2 12 PU EDITIONS PHYSIQUE PI LES ULIS CEDEX PA Z I DE COURTABOEUF AVE 7 AV DU HOGGAR, BP 112, 91944 LES ULIS CEDEX, FRANCE SN 1155-4339 J9 J PHYS IV JI J. Phys. IV PD APR PY 1997 VL 7 IS C2 BP 777 EP 779 DI 10.1051/jp4:1997234 PN 2 PG 3 WC Physics, Multidisciplinary SC Physics GA XQ952 UT WOS:A1997XQ95200035 ER PT J AU Gates, WP Hunter, DB Nuessle, PR Bertsch, PM AF Gates, WP Hunter, DB Nuessle, PR Bertsch, PM TI A time resolved XANES study of an organo-clay redox system SO JOURNAL DE PHYSIQUE IV LA English DT Article; Proceedings Paper CT 9th International Conference on X-Ray Absorption Fine Structure CY AUG 26-30, 1996 CL GRENOBLE, FRANCE SP European Synchrotron Radiat Facil, Ville Grenoble, Univ Joseph Fourier Grenoble, Minist Educ Natl, CNRS, CEA, Soc Francaise Chim, Jobin Yvon, Microcontrole, Eurisys Mesures, Inst Francais Petr, Air Liquide, Huber Diffrakt Teck, Haldor Topsoe A/S ID TETRAPHENYLBORON; DEGRADATION; IRON AB In situ, time-resolved X-ray absorption near edge structure (XANES) spectroscopic measurements of tetraphenylboron (TPB)-treated Fe-bearing clay minerals were conducted to investigate whether smectite structural Fe was reduced during surface-enhanced oxidative degradation of TPB. Reference samples were prepared by reducing varying amounts of structural Fe with Na-dithionite in an inert atmosphere. Analysis of the Fe K-alpha X-ray fluorescence near edge structure of reference and TPB-treated samples was accomplished by comparing the ratios of edge crest intensities at energies corresponding to oxidized and dithionite-reduced samples following intensity normalization and energy calibration. About 15% of nontronite structural Fe was reduced during the course of the reaction with TPB, whereas more than 50% of the structural Fe in montmorillonite was reduced. XANES spectroscopy provided additional spectroscopic evidence for differences in the reactivity of crystallographic sites of Fe within montmorillonites (both cis and trans Fe) and nontronites (predominantly cis Fe) and suggests that TPB reacted preferentially with trans Fe. RP Gates, WP (reprint author), UNIV GEORGIA,SAVANNAH RIVER ECOL LAB,ADV ANALYT CTR ENVIRONM SCI,DRAWER E,AIKEN,SC 29802, USA. NR 7 TC 2 Z9 2 U1 1 U2 3 PU EDITIONS PHYSIQUE PI LES ULIS CEDEX PA Z I DE COURTABOEUF AVE 7 AV DU HOGGAR, BP 112, 91944 LES ULIS CEDEX, FRANCE SN 1155-4339 J9 J PHYS IV JI J. Phys. IV PD APR PY 1997 VL 7 IS C2 BP 785 EP 787 DI 10.1051/jp4:1997236 PN 2 PG 3 WC Physics, Multidisciplinary SC Physics GA XQ952 UT WOS:A1997XQ95200037 ER PT J AU Allen, PG Shuh, DK Bucher, JJ Edelstein, NM Reich, T Denecke, MA Nitsche, H AF Allen, PG Shuh, DK Bucher, JJ Edelstein, NM Reich, T Denecke, MA Nitsche, H TI Chemical speciation studies of radionuclides by XAFS SO JOURNAL DE PHYSIQUE IV LA English DT Article; Proceedings Paper CT 9th International Conference on X-Ray Absorption Fine Structure CY AUG 26-30, 1996 CL GRENOBLE, FRANCE SP European Synchrotron Radiat Facil, Ville Grenoble, Univ Joseph Fourier Grenoble, Minist Educ Natl, CNRS, CEA, Soc Francaise Chim, Jobin Yvon, Microcontrole, Eurisys Mesures, Inst Francais Petr, Air Liquide, Huber Diffrakt Teck, Haldor Topsoe A/S ID NEAR-EDGE STRUCTURE; CEMENT AB The local structures of U(VI) oxide precipitates produced as a function of LiOH concentration have been studied by XAFS. Curve-fitting analyses indicate that the solid formed in 0.1 M LiOH is similar to a schoepite-like phase where distinct linear uranyl ions (UO22+) are bridged along the equator by OH. ions. At higher LiOH concentrations, the uranyl groups become elongated and the precipitate structure resembles that of a uranate salt. We have studied the speciation of Tc in cement waste forms, where it is desirable to stabilize the highly soluble form of Tc(VII), TcO4-, by in situ reduction to a less mobile form, i.e. Tc(IV). Using the XANES to measure the oxidation state, our results show that significant reduction takes place in the presence of the cement additives blast furnace slag (BFS) and Na2S. In addition, EXAFS data show that in situ reduction leads to formation of Tc clusters possessing S and Tc coordination. C1 LAWRENCE LIVERMORE NATL LAB,GLENN T SEABORG INST TRANSACTINIUM SCI,LIVERMORE,CA 94551. ROSSENDORF INC,FORSCHUNGSZENTRUM ROSSENDORF EV,INST RADIOCHEM,D-01314 DRESDEN,GERMANY. RP Allen, PG (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV CHEM SCI,ACTINIDE CHEM GRP,BERKELEY,CA 94720, USA. RI Reich, Tobias/C-7064-2016 OI Reich, Tobias/0000-0002-5600-3951 NR 7 TC 5 Z9 5 U1 0 U2 7 PU EDITIONS PHYSIQUE PI LES ULIS CEDEX PA Z I DE COURTABOEUF AVE 7 AV DU HOGGAR, BP 112, 91944 LES ULIS CEDEX, FRANCE SN 1155-4339 J9 J PHYS IV JI J. Phys. IV PD APR PY 1997 VL 7 IS C2 BP 789 EP 792 DI 10.1051/jp4:1997237 PN 2 PG 4 WC Physics, Multidisciplinary SC Physics GA XQ952 UT WOS:A1997XQ95200038 ER PT J AU Lamble, GM Reeder, RJ Northrup, PA AF Lamble, GM Reeder, RJ Northrup, PA TI Characterization of heavy metal incorporation in calcite by XAFS spectroscopy SO JOURNAL DE PHYSIQUE IV LA English DT Article; Proceedings Paper CT 9th International Conference on X-Ray Absorption Fine Structure CY AUG 26-30, 1996 CL GRENOBLE, FRANCE SP European Synchrotron Radiat Facil, Ville Grenoble, Univ Joseph Fourier Grenoble, Minist Educ Natl, CNRS, CEA, Soc Francaise Chim, Jobin Yvon, Microcontrole, Eurisys Mesures, Inst Francais Petr, Air Liquide, Huber Diffrakt Teck, Haldor Topsoe A/S ID ABSORPTION FINE-STRUCTURE; SURFACE-STRUCTURE; GROWTH; COEFFICIENTS; TEMPERATURE; CHEMISTRY AB Zn and Co K-edge XAFS have been analyzed for spectra obtained from synthetic calcite that incorporated trace amounts of Zn2+ and Co2+ during growth from aqueous solutions at room temperature. Zn and Co concentrations in the calcite ranged from 250 to 2150 ppm. Analysis of the first shells indicates that the immediate coordination of both metal ions is approximately six oxygens al 2.11-2.12 Angstrom. These results are consistent with octahedral coordination at the unique Ca site in calcite. The observation that Co and Zn attain similar coordination in the bulk following incorporation suggests that their strongly contrasting surface site preferences are not expressed after being buried by subsequent growth layers. C1 BROOKHAVEN NATL LAB,UPTON,NY 11973. SUNY STONY BROOK,DEPT EARTH & SPACE SCI,STONY BROOK,NY 11794. NR 16 TC 16 Z9 16 U1 0 U2 3 PU EDITIONS PHYSIQUE PI LES ULIS CEDEX PA Z I DE COURTABOEUF AVE 7 AV DU HOGGAR, BP 112, 91944 LES ULIS CEDEX, FRANCE SN 1155-4339 J9 J PHYS IV JI J. Phys. IV PD APR PY 1997 VL 7 IS C2 BP 793 EP 797 DI 10.1051/jp4:1997238 PN 2 PG 5 WC Physics, Multidisciplinary SC Physics GA XQ952 UT WOS:A1997XQ95200039 ER PT J AU Wasserman, SR Yuchs, SE Giaquinta, D Soderholm, L Song, K AF Wasserman, SR Yuchs, SE Giaquinta, D Soderholm, L Song, K TI Nanoscale encapsulation: The structure of cations in hydrophobic microporous aluminosilicates SO JOURNAL DE PHYSIQUE IV LA English DT Article; Proceedings Paper CT 9th International Conference on X-Ray Absorption Fine Structure CY AUG 26-30, 1996 CL GRENOBLE, FRANCE SP European Synchrotron Radiat Facil, Ville Grenoble, Univ Joseph Fourier Grenoble, Minist Educ Natl, CNRS, CEA, Soc Francaise Chim, Jobin Yvon, Microcontrole, Eurisys Mesures, Inst Francais Petr, Air Liquide, Huber Diffrakt Teck, Haldor Topsoe A/S ID X-RAY-ABSORPTION; MONOLAYERS AB Hydrophobic microporous aluminosilicates created by the modification of zeolites and clays are currently being investigated as storage media for hazardous cations. Addition of an organic monolayer to the surface of an aluminosilicate after introduction of an ion into the zeolite or clay reduces the interaction of water with the material. The resultant systems are approximately 20 times more resistant to leaching of the stored ion than the unmodified ion-exchanged materials. XAS spectra demonstrate that byproducts from the organic modifier can complex with the encapsulated cation. This complexation can result in a decreased affinity of the cation for the aluminosilicate matrix. Changing the organic modifier eliminates this problem. XAS spectra also indicate that the reactivity and subsequent speciation of the encapsulated ion alters upon application of the hydrophobic layer. RP Wasserman, SR (reprint author), ARGONNE NATL LAB,DIV CHEM,9700 S CASS AVE,ARGONNE,IL 60439, USA. NR 10 TC 1 Z9 1 U1 1 U2 1 PU EDITIONS PHYSIQUE PI LES ULIS CEDEX PA Z I DE COURTABOEUF AVE 7 AV DU HOGGAR, BP 112, 91944 LES ULIS CEDEX, FRANCE SN 1155-4339 J9 J PHYS IV JI J. Phys. IV PD APR PY 1997 VL 7 IS C2 BP 803 EP 807 PN 2 PG 5 WC Physics, Multidisciplinary SC Physics GA XQ952 UT WOS:A1997XQ95200041 ER PT J AU Kemner, KM Hunter, DB Gall, EJ Bertsch, PM Kirkland, JP Elam, WT AF Kemner, KM Hunter, DB Gall, EJ Bertsch, PM Kirkland, JP Elam, WT TI Molecular characterization of Cr phases in contaminated soils by Cr and Fe EXAFS: A tool for evaluating chemical remediation strategies SO JOURNAL DE PHYSIQUE IV LA English DT Article; Proceedings Paper CT 9th International Conference on X-Ray Absorption Fine Structure CY AUG 26-30, 1996 CL GRENOBLE, FRANCE SP European Synchrotron Radiat Facil, Ville Grenoble, Univ Joseph Fourier Grenoble, Minist Educ Natl, CNRS, CEA, Soc Francaise Chim, Jobin Yvon, Microcontrole, Eurisys Mesures, Inst Francais Petr, Air Liquide, Huber Diffrakt Teck, Haldor Topsoe A/S AB The successful remediation of Cr contaminated soils via chemical reduction and stabilization of soluble, toxic Cr(VI) species to insoluble Cr(III) species relies on the long term leachability and reoxidation of reduced Cr compounds. Information of Cr chemical environments is invaluable for evaluating the efficiency of proposed stabilization technologies. We describe a matrix of Fe and Cr K-edge EXAFS data on synthetic model compounds that have been used to identify different Fe and Cr local environments of two soil samples. C1 USN,RES LAB,WASHINGTON,DC 20375. UNIV GEORGIA,SAVANNAH RIVER ECOL LAB,ADV ANALYT CTR ENVIRONM SCI,AIKEN,SC. SFA INC,LANDOVER,MD 20785. NR 6 TC 4 Z9 4 U1 1 U2 2 PU EDITIONS PHYSIQUE PI LES ULIS CEDEX PA Z I DE COURTABOEUF AVE 7 AV DU HOGGAR, BP 112, 91944 LES ULIS CEDEX, FRANCE SN 1155-4339 J9 J PHYS IV JI J. Phys. IV PD APR PY 1997 VL 7 IS C2 BP 811 EP 812 DI 10.1051/jp4:1997242 PN 2 PG 2 WC Physics, Multidisciplinary SC Physics GA XQ952 UT WOS:A1997XQ95200043 ER PT J AU Bertsch, PM Hunter, DB Nuessle, PR Clark, SB AF Bertsch, PM Hunter, DB Nuessle, PR Clark, SB TI Molecular characterization of contaminants in soils by spatially resolved XRF & XANES spectroscopy SO JOURNAL DE PHYSIQUE IV LA English DT Article; Proceedings Paper CT 9th International Conference on X-Ray Absorption Fine Structure CY AUG 26-30, 1996 CL GRENOBLE, FRANCE SP European Synchrotron Radiat Facil, Ville Grenoble, Univ Joseph Fourier Grenoble, Minist Educ Natl, CNRS, CEA, Soc Francaise Chim, Jobin Yvon, Microcontrole, Eurisys Mesures, Inst Francais Petr, Air Liquide, Huber Diffrakt Teck, Haldor Topsoe A/S AB Using a dedicated microprobe beam line (X-26A NSLS) we have conducted spatially resolved XRF and XAS studies on a variety of environmental samples and on samples produced in waste isolation and processing activities. XANES spectroscopy has provided detailed information on the oxidation states of U in contaminated soils on regions as small as 50 mu m, with minimal sample manipulation. Qualitative information on bonding environments of U have been deduced based upon elemental associations generated at 10 mu m spatial resolution on identical regions where complete XANES spectra were collected and also on the 'fingerprint' or multiple scattering regions of the XANES spectra. Distinct regions within the sediments were found to contain phases of predominately U(VI) and U(IV). On the spatial scale examined, the U(VI) was present both as diffusely distributed and as discrete phases, whereas phases containing predominately U(IV) were present exclusively as discrete phases. Examination of a large population of individual grains prior to and following extraction with a sodium carbonate lixiviant, revealed that the U(IV) phases were highly enriched following extraction, suggesting more selective solubilization of U(VI) phases. This study illustrates the utility of combining spatially resolved XRF and XANES to evaluate chemical intervention technologies. RP Bertsch, PM (reprint author), UNIV GEORGIA,SREL,ADV ANALYT CTR ENVIRONM SCI,DRAWER E,AIKEN,SC 29802, USA. NR 3 TC 6 Z9 6 U1 0 U2 3 PU EDITIONS PHYSIQUE PI LES ULIS CEDEX PA Z I DE COURTABOEUF AVE 7 AV DU HOGGAR, BP 112, 91944 LES ULIS CEDEX, FRANCE SN 1155-4339 J9 J PHYS IV JI J. Phys. IV PD APR PY 1997 VL 7 IS C2 BP 817 EP 818 DI 10.1051/jp4:1997245 PN 2 PG 2 WC Physics, Multidisciplinary SC Physics GA XQ952 UT WOS:A1997XQ95200046 ER PT J AU Newville, M Fulton, JL Pfund, DM Wallen, SL Stern, EA Ma, Y AF Newville, M Fulton, JL Pfund, DM Wallen, SL Stern, EA Ma, Y TI XAFS measurements of Rb-O bonds in ambient and supercritical water SO JOURNAL DE PHYSIQUE IV LA English DT Article; Proceedings Paper CT 9th International Conference on X-Ray Absorption Fine Structure CY AUG 26-30, 1996 CL GRENOBLE, FRANCE SP European Synchrotron Radiat Facil, Ville Grenoble, Univ Joseph Fourier Grenoble, Minist Educ Natl, CNRS, CEA, Soc Francaise Chim, Jobin Yvon, Microcontrole, Eurisys Mesures, Inst Francais Petr, Air Liquide, Huber Diffrakt Teck, Haldor Topsoe A/S ID ABSORPTION AB XAFS measurements and analyses of Rb+ ions in 0.5 molal RbBr at ambient and several supercritical (P > P-c = 220 bar, T > T-c = 374 degrees C) conditions are presented. The first coordination shell of Rb+ ion is seen to be dominated by oxygen from nearby water molecules. Upon going from ambient to supercritical conditions, the Rb-O coordination number decreases significantly and the Rb-O distance decreases by similar to 0.10 Angstrom relative to the ambient Rb-O distance (similar to 2.93 Angstrom). Although ion pairing has been predicted for supercritical conditions (due in part to a substantial decrease of the dielectric constant at the critical point), and has been observed with XAFS in other aqueous solutions, we see no direct evidence of pairing of Br- with Rb+ in our measurements. C1 PACIFIC NW LAB, RICHLAND, WA 99352 USA. UNIV WASHINGTON, DEPT PHYS, SEATTLE, WA 98195 USA. RP Newville, M (reprint author), LAWRENCE LIVERMORE NATL LAB, L-219, LIVERMORE, CA 94550 USA. NR 7 TC 1 Z9 1 U1 0 U2 1 PU EDITIONS PHYSIQUE PI LES ULIS CEDEX PA Z I DE COURTABOEUF AVE 7 AV DU HOGGAR, BP 112, 91944 LES ULIS CEDEX, FRANCE SN 1155-4339 J9 J PHYS IV JI J. Phys. IV PD APR PY 1997 VL 7 IS C2 BP 1007 EP 1008 DI 10.1051/jp4:19972118 PN 2 PG 2 WC Physics, Multidisciplinary SC Physics GA XQ952 UT WOS:A1997XQ95200119 ER PT J AU Farges, F Brown, GE Wu, Z AF Farges, F Brown, GE Wu, Z TI Coordination of actinides in silicate melts SO JOURNAL DE PHYSIQUE IV LA English DT Article; Proceedings Paper CT 9th International Conference on X-Ray Absorption Fine Structure CY AUG 26-30, 1996 CL GRENOBLE, FRANCE SP European Synchrotron Radiat Facil, Ville Grenoble, Univ Joseph Fourier Grenoble, Minist Educ Natl, CNRS, CEA, Soc Francaise Chim, Jobin Yvon, Microcontrole, Eurisys Mesures, Inst Francais Petr, Air Liquide, Huber Diffrakt Teck, Haldor Topsoe A/S ID ELEMENTS AB The structural environments around Th(IV) and U(VI) at concentrations ranging from 90 ppm to 7 wt.% were investigated in glasses and melts of Na di-and trisilicate compositions between 293 and 1550 K using x-ray absorption fine structure (XAFS) spectroscopy. Data for model compounds were collected at temperatures up to 2000 K in order to quantify the magnitude of anharmonic effects. Data for glasses and melts were collected and analyzed considering anharmonic (cumulant-expansion), curved-wave and multiple-scattering effects;In the glasses and melts studied, U(VI) occurs as uranyl groups [d(U(VI)-O approximate to 1.78 and 2.25(3) Angstrom] and Th(IV) occurs as a mixture of 6- and 8-coordinated Th at the 1-3 wt.% Th level, but as 8-coordinated Th at trace levels (90-1000 ppm). These two actinides do not undergo significant coordination changes during the glass-to-melt transformation. However, special care in the data analysis protocol is needed to avoid the effects of anharmonicity (due to both positional and thermal effects) which tend to artificially increase the (apparent) amount of 6-coordinated Th. C1 UNIV MARNE LA VALLEE,URA 734 CNRS,F-93166 NOISY LE GRAND,FRANCE. UNIV MARNE LA VALLEE,LURE,F-93166 NOISY LE GRAND,FRANCE. STANFORD UNIV,DEPT GEOL & ENVIRONM SCI,STANFORD,CA 94305. STANFORD UNIV,SSRL,STANFORD,CA 94305. RP Farges, F (reprint author), UNIV MARNE LA VALLEE,LAB PHYS & MECAN GEOMAT,F-93166 NOISY LE GRAND,FRANCE. NR 6 TC 3 Z9 3 U1 2 U2 5 PU EDITIONS PHYSIQUE PI LES ULIS CEDEX PA Z I DE COURTABOEUF AVE 7 AV DU HOGGAR, BP 112, 91944 LES ULIS CEDEX, FRANCE SN 1155-4339 J9 J PHYS IV JI J. Phys. IV PD APR PY 1997 VL 7 IS C2 BP 1009 EP 1010 DI 10.1051/jp4:19972119 PN 2 PG 2 WC Physics, Multidisciplinary SC Physics GA XQ952 UT WOS:A1997XQ95200120 ER PT J AU Mayanovic, RA Anderson, AJ Bajt, S AF Mayanovic, RA Anderson, AJ Bajt, S TI Microbeam XAFS studies on fluid inclusions at high temperatures SO JOURNAL DE PHYSIQUE IV LA English DT Article; Proceedings Paper CT 9th International Conference on X-Ray Absorption Fine Structure CY AUG 26-30, 1996 CL GRENOBLE, FRANCE SP European Synchrotron Radiat Facil, Ville Grenoble, Univ Joseph Fourier Grenoble, Minist Educ Natl, CNRS, CEA, Soc Francaise Chim, Jobin Yvon, Microcontrole, Eurisys Mesures, Inst Francais Petr, Air Liquide, Huber Diffrakt Teck, Haldor Topsoe A/S AB Zn and Fe K-edge microbeam XAFS measurements have been made on individual fluid inclusions in quartz at temperatures ranging from 25 degrees C to 500 degrees C. Analysis of Zn K-edge XAFS spectra shows that the ZnCl42- complex is predominant at all temperatures up to and including 430 degrees C. The Zn-Cl bond length was found to decrease uniformly with temperature. up to nearly 2% at 430 degrees C in comparison to the value at 25 degrees C. The iron ion appears to be predominantly hydrated up to some temperature between 100 degrees C and 200 degrees C. Above 200 degrees C, iron in the inclusions is predominantly coordinated by chlorine ligands. C1 ST FRANCIS XAVIER UNIV,DEPT GEOL,ANTIGONISH,NS B2G 1C0,CANADA. LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550. RP Mayanovic, RA (reprint author), SW MISSOURI STATE UNIV,DEPT PHYS & ASTRON,SPRINGFIELD,MO 65804, USA. RI Bajt, Sasa/G-2228-2010 NR 7 TC 9 Z9 9 U1 0 U2 0 PU EDITIONS PHYSIQUE PI LES ULIS CEDEX PA Z I DE COURTABOEUF AVE 7 AV DU HOGGAR, BP 112, 91944 LES ULIS CEDEX, FRANCE SN 1155-4339 J9 J PHYS IV JI J. Phys. IV PD APR PY 1997 VL 7 IS C2 BP 1029 EP 1030 DI 10.1051/jp4:19972129 PN 2 PG 2 WC Physics, Multidisciplinary SC Physics GA XQ952 UT WOS:A1997XQ95200130 ER PT J AU Staub, U Soderholm, L Skanthakumar, S Antonio, MR AF Staub, U Soderholm, L Skanthakumar, S Antonio, MR TI Oxidation state of the unusual rare earth (R=Ce, Pr and Tb) in double-layer high-T-c superconductors SO JOURNAL DE PHYSIQUE IV LA English DT Article; Proceedings Paper CT 9th International Conference on X-Ray Absorption Fine Structure CY AUG 26-30, 1996 CL GRENOBLE, FRANCE SP European Synchrotron Radiat Facil, Ville Grenoble, Univ Joseph Fourier Grenoble, Minist Educ Natl, CNRS, CEA, Soc Francaise Chim, Jobin Yvon, Microcontrole, Eurisys Mesures, Inst Francais Petr, Air Liquide, Huber Diffrakt Teck, Haldor Topsoe A/S ID X-RAY-ABSORPTION; VALENCE; SPECTROSCOPY; YBA2CU3O7 AB X-ray absorption and magnetization experiments are used to describe the oxidation states of the rare earth ions R=Ce, Pr and Tb in the double layer high-T-c superconducting series RBa2Cu3O7 and Pb2Sr2R1-xCaxCu3O8. We obtained the same oxidation states for the rare earths in these two classes of compounds, namely, R=Ce tetravalent and R=Pr and Tb trivalent. C1 ARGONNE NATL LAB,DIV CHEM,ARGONNE,IL 60439. RP Staub, U (reprint author), PAUL SCHERRER INST,SWISS LIGHT SOURCE PROJECT,CH-5232 VILLIGEN,SWITZERLAND. RI Staub, Urs/C-4914-2015 NR 11 TC 7 Z9 7 U1 0 U2 1 PU EDITIONS PHYSIQUE PI LES ULIS CEDEX PA Z I DE COURTABOEUF AVE 7 AV DU HOGGAR, BP 112, 91944 LES ULIS CEDEX, FRANCE SN 1155-4339 J9 J PHYS IV JI J. Phys. IV PD APR PY 1997 VL 7 IS C2 BP 1077 EP 1079 DI 10.1051/jp4:19972141 PN 2 PG 3 WC Physics, Multidisciplinary SC Physics GA XQ952 UT WOS:A1997XQ95200142 ER PT J AU Yacoby, Y Heald, SM Stern, EA AF Yacoby, Y Heald, SM Stern, EA TI Local oxygen octahedra rotations in Ba1-xKxBiO3 SO JOURNAL DE PHYSIQUE IV LA English DT Article; Proceedings Paper CT 9th International Conference on X-Ray Absorption Fine Structure CY AUG 26-30, 1996 CL GRENOBLE, FRANCE SP European Synchrotron Radiat Facil, Ville Grenoble, Univ Joseph Fourier Grenoble, Minist Educ Natl, CNRS, CEA, Soc Francaise Chim, Jobin Yvon, Microcontrole, Eurisys Mesures, Inst Francais Petr, Air Liquide, Huber Diffrakt Teck, Haldor Topsoe A/S ID X-RAY-ABSORPTION; FINE-STRUCTURE; CURVED-WAVE; SUPERCONDUCTIVITY; SYSTEM AB We report XAFS analyses results of Ba0.6K0.4BiO3 in the temperature range from 10K to 300K extending out to fourth nearest neighbors. The results show that the local structure differs substantially from the average structure determined by neutron diffraction measurements. The results in superconducting Ba0.6K0.4BiO3, are consistent with oxygen octahedra rotations either around [111] or [110] type axes. The rotation angles are 4.5 degrees up to at least T = 220K if the rotation is assumed to be about [111] type axes: This local rotation exists in spite of the fact that the crystal is on the average cubic at all temperatures. The existence oi these local rotations suggests that the charge carrier pairing mechanism may be enhanced through the interaction with the bistable states oi the oxygen octahedra as proposed by Plakida[4] and Hardy and Flocken[5]. C1 ARGONNE NATL LAB,ARGONNE,IL 60439. UNIV WASHINGTON,DEPT PHYS,SEATTLE,WA 98195. RP Yacoby, Y (reprint author), HEBREW UNIV JERUSALEM,RACAH INST PHYS,IL-91904 JERUSALEM,ISRAEL. NR 14 TC 1 Z9 1 U1 0 U2 0 PU EDITIONS PHYSIQUE PI LES ULIS CEDEX PA Z I DE COURTABOEUF AVE 7 AV DU HOGGAR, BP 112, 91944 LES ULIS CEDEX, FRANCE SN 1155-4339 J9 J PHYS IV JI J. Phys. IV PD APR PY 1997 VL 7 IS C2 BP 1081 EP 1083 DI 10.1051/jp4:19972142 PN 2 PG 3 WC Physics, Multidisciplinary SC Physics GA XQ952 UT WOS:A1997XQ95200143 ER PT J AU Saini, NL Lanzara, A Bianconi, A Hazemann, JL Soldo, Y Johnston, DC AF Saini, NL Lanzara, A Bianconi, A Hazemann, JL Soldo, Y Johnston, DC TI Non-homogeneity of the CuO2 plane of the oxygen doped La2CuO4.1 system by polarized EXAFS SO JOURNAL DE PHYSIQUE IV LA English DT Article; Proceedings Paper CT 9th International Conference on X-Ray Absorption Fine Structure CY AUG 26-30, 1996 CL GRENOBLE, FRANCE SP European Synchrotron Radiat Facil, Ville Grenoble, Univ Joseph Fourier Grenoble, Minist Educ Natl, CNRS, CEA, Soc Francaise Chim, Jobin Yvon, Microcontrole, Eurisys Mesures, Inst Francais Petr, Air Liquide, Huber Diffrakt Teck, Haldor Topsoe A/S ID ABSORPTION FINE-STRUCTURE; CENTERED LATTICE INSTABILITIES; AXIAL OXYGEN; CUPRATE SUPERCONDUCTORS; ANHARMONIC SYSTEMS; YBA2CU3O7; CRYSTAL AB Temperature dependent in-plane polarized Cu K-edge extended x-ray absorption fine structure (EXAFS) study has been carried out on a high quality single crystal of oxygen doped La2CuO4.1 (LCO) system to investigate the local structure around Cu. The EXAFS data recorded with high degree of plane polarization and up to high momentum transfer (Q=40 A(-1) = 2k) allowed the quantitative determination of the distorted and undistorted Cu planes. The determination of the Cu-O(planar) distances shows presence of minority Cu sites characterized by two longer Cu-O(planar) bonds and a tilting of 15 degrees with the average crystallographic structure at T < T-s similar to 150 K. The data show the coexistence of localized and itinerant charges trapped into stripes of distorted and undistorted domains within the CuO2 plane. C1 CNRS, LAB CRISTALLOG, F-38042 GRENOBLE, FRANCE. IOWA STATE UNIV, AMES LAB, AMES, IA 50011 USA. IOWA STATE UNIV, DEPT PHYS & ASTRON, AMES, IA 50011 USA. RP Saini, NL (reprint author), UNIV ROMA LA SAPIENZA, DIPARTIMENTO FIS, P A MORO 2, I-00185 ROME, ITALY. RI Bianconi, Antonio/J-3997-2013; Saini, Naurang/J-7918-2013 OI Bianconi, Antonio/0000-0001-9795-3913; Saini, Naurang/0000-0003-3684-1517 NR 25 TC 0 Z9 0 U1 0 U2 0 PU EDP SCIENCES S A PI LES ULIS CEDEX A PA 17, AVE DU HOGGAR, PA COURTABOEUF, BP 112, F-91944 LES ULIS CEDEX A, FRANCE SN 1155-4339 J9 J PHYS IV JI J. Phys. IV PD APR PY 1997 VL 7 IS C2 BP 1089 EP 1091 DI 10.1051/jp4:19972144 PN 2 PG 3 WC Physics, Multidisciplinary SC Physics GA XQ952 UT WOS:A1997XQ95200145 ER PT J AU Coulthard, I Bzowski, A Sham, TK Heald, SM Kuhn, M AF Coulthard, I Bzowski, A Sham, TK Heald, SM Kuhn, M TI M-3,M-2 and L-3,L-2 XAFS of Au and Pt nanoparticles on porous silicon SO JOURNAL DE PHYSIQUE IV LA English DT Article; Proceedings Paper CT 9th International Conference on X-Ray Absorption Fine Structure CY AUG 26-30, 1996 CL GRENOBLE, FRANCE SP European Synchrotron Radiat Facil, Ville Grenoble, Univ Joseph Fourier Grenoble, Minist Educ Natl, CNRS, CEA, Soc Francaise Chim, Jobin Yvon, Microcontrole, Eurisys Mesures, Inst Francais Petr, Air Liquide, Huber Diffrakt Teck, Haldor Topsoe A/S AB XAFS measurements at both the M-3,M-2 and L-3,L-2 edges of Pt and Au as well as scanning electron microscopy studies have been carried out for a series of porous silicon specimens onto which fine particles of Au and Pt with nanometre and tens of nanometre dimensions have been dispersed. A wet chemistry technique developed in our laboratory was used for the deposition. The Au XAFS clearly show that the Au deposits are essentially Au metal while the Pt deposits exhibit Features that are noticeably different from that of metallic Pt. The M-3,M-2 and L-3,L-2 the XANES and their implications are discussed. C1 PACIFIC NW LAB, RICHLAND, WA 99352 USA. TULANE UNIV, DEPT PHYS, NEW ORLEANS, LA 70118 USA. RP Coulthard, I (reprint author), UNIV WESTERN ONTARIO, DEPT CHEM, LONDON, ON N6A 5B7, CANADA. NR 10 TC 1 Z9 1 U1 0 U2 2 PU EDITIONS PHYSIQUE PI LES ULIS CEDEX PA Z I DE COURTABOEUF AVE 7 AV DU HOGGAR, BP 112, 91944 LES ULIS CEDEX, FRANCE SN 1155-4339 J9 J PHYS IV JI J. Phys. IV PD APR PY 1997 VL 7 IS C2 BP 1133 EP 1134 DI 10.1051/jp4:19972159 PN 2 PG 2 WC Physics, Multidisciplinary SC Physics GA XQ952 UT WOS:A1997XQ95200160 ER PT J AU Mansour, AN Melendres, CA AF Mansour, AN Melendres, CA TI X-ray absorption spectra and the local structure of nickel in some oxycompounds and fluorides SO JOURNAL DE PHYSIQUE IV LA English DT Article; Proceedings Paper CT 9th International Conference on X-Ray Absorption Fine Structure CY AUG 26-30, 1996 CL GRENOBLE, FRANCE SP European Synchrotron Radiat Facil, Ville Grenoble, Univ Joseph Fourier Grenoble, Minist Educ Natl, CNRS, CEA, Soc Francaise Chim, Jobin Yvon, Microcontrole, Eurisys Mesures, Inst Francais Petr, Air Liquide, Huber Diffrakt Teck, Haldor Topsoe A/S ID HYDROXIDE AB X-ray absorption spectra were measured for a number of nickel oxycompounds and fluorides which contain nickel with valencies in the range of 2 to 4. Information on the local structure and nature of bonding of nickel were derived using theoretical standards generated with the FEFF code. The energies of the main Ni K-edge and the pre-edge peak were found to shift to higher values by about 1.5 and 0.6 eV, respectively, per unit increase in the valency of nickel. The average Ni-O and Ni-F bond length within the octahedron decreased linearly with increase in nickel valency from 2 to 4. The local structure parameters for the higher valency nickel oxycompounds are consistent with a multi-phase model in which up to three phases corresponding to Ni2+, Ni3+, and Ni4+ could be present in different proportions depending on preparation procedures. C1 ARGONNE NATL LAB,DIV SCI MAT,ARGONNE,IL 60439. ARGONNE NATL LAB,DIV CHEM TECHNOL,ARGONNE,IL 60439. RP Mansour, AN (reprint author), USN,CTR SURFACE WARFARE,CARDEROCK DIV,CODE 684,10901 NEW HAMPSHIRE AVE,SILVER SPRING,MD 20903, USA. NR 8 TC 11 Z9 11 U1 0 U2 2 PU EDITIONS PHYSIQUE PI LES ULIS CEDEX PA Z I DE COURTABOEUF AVE 7 AV DU HOGGAR, BP 112, 91944 LES ULIS CEDEX, FRANCE SN 1155-4339 J9 J PHYS IV JI J. Phys. IV PD APR PY 1997 VL 7 IS C2 BP 1171 EP 1172 DI 10.1051/jp4:19972178 PN 2 PG 2 WC Physics, Multidisciplinary SC Physics GA XQ952 UT WOS:A1997XQ95200179 ER PT J AU Ayache, J Thorel, A LeDuigou, J Bonevich, J Dahmen, U AF Ayache, J Thorel, A LeDuigou, J Bonevich, J Dahmen, U TI Influence of the growth mechanism on the grain boundary structure in YBa2Cu3O7 thin film bicrystals SO JOURNAL OF ALLOYS AND COMPOUNDS LA English DT Article; Proceedings Paper CT Symposium on High Temperature Superconductor Thin Films - Growth Mechanisms, Interfaces, Multilayers, at the 1996 Spring Meeting of the European-Materials-Society CY JUN 04-07, 1996 CL STRASBOURG, FRANCE SP European Mat Res Soc DE growth; grain boundary structure; YBa2Cu3O7 thin film bicrystals ID WEAK LINKS AB The growth control of thin YBa2Cu3O7 (YBCO) film bicrystals determines the quality of Josephson junctions and weak links. Previous TEM experiments on various thin him bicrystals showed grain boundary oscillations that were not clearly explained. We combined AFM, SEM, conventional TEM and HRTEM in order to perform a complete characterization of both substrate and YBa2Cu3O7 thin film bicrystals. Our results clearly show that the grain boundary oscillations are due to the YBCO growth mechanisms leading to a conflictual crystallographic situation at the grain boundary. The resulting crystallographic structure of the grain boundary may affect the interpretation of several recant experiments purporting to determine the nature of the HTC superconductivity. C1 ECOLE MINES PARIS,F-91003 EVRY,FRANCE. CNRS,LPS,F-92125 MEUDON,FRANCE. NATL INST STAND & TECHNOL,DIV MET,GAITHERSBURG,MD 20899. UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,NATL CTR ELECTRON MICROSCOPY,MSD,BERKELEY,CA 94720. RP Ayache, J (reprint author), CNRS,IN2P3,CSNSM,BAT 108,F-91405 ORSAY,FRANCE. NR 14 TC 3 Z9 3 U1 0 U2 0 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0925-8388 J9 J ALLOY COMPD JI J. Alloy. Compd. PD APR PY 1997 VL 251 IS 1-2 BP 78 EP 82 DI 10.1016/S0925-8388(96)02774-0 PG 5 WC Chemistry, Physical; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Chemistry; Materials Science; Metallurgy & Metallurgical Engineering GA XM340 UT WOS:A1997XM34000019 ER PT J AU Buchholz, DB Lei, JS Mahajan, S Markworth, PR Chang, RPH Hinds, B Marks, TJ Huang, Y Merkle, KL AF Buchholz, DB Lei, JS Mahajan, S Markworth, PR Chang, RPH Hinds, B Marks, TJ Huang, Y Merkle, KL TI The growth of (001) YBa2Cu3O(7-delta) thin films on (001) MgO by pulsed organo-metallic beam epitaxy with controlled in-plane orientation SO JOURNAL OF ALLOYS AND COMPOUNDS LA English DT Article; Proceedings Paper CT Symposium on High Temperature Superconductor Thin Films - Growth Mechanisms, Interfaces, Multilayers, at the 1996 Spring Meeting of the European-Materials-Society CY JUN 04-07, 1996 CL STRASBOURG, FRANCE SP European Mat Res Soc DE YBCO; pulsed organo-metallic beam-epitaxy ID GRAIN-BOUNDARY JUNCTIONS; SINGLE-CRYSTAL MGO; YBA2CU3O7; BICRYSTALS; MGO(001); SURFACES; BA AB Thin films of (001) YBCO are grown on epitaxially polished (001) MgO by pulsed organo-metallic beam epitaxy. The in-plane orientation of the film is controlled by the thickness of a BaO layer, grown in situ, Frier to the YBCO growth, For thin BaO layers (approximate to 1.1x10(15) Ba cm(-2)) the films grow. [100]YBCO parallel to[100]MgO. For YBCO films grown with thin BaO layers (>approximate to 0.7 times 10(15) Ba cm(-2)), ex situ, low energy Ar+ ion sputtering of the MgO surface prior to film growth will also induce a change of in-plane orientation from [110]YBCO parallel to[100]MgO on epitaxial polished MgO to [100]YBCO parallel to[100]MgO on Ar+ sputtered MgO, A mechanism that relates the change in YBCO in-plane orientation to a change in the structure of the initial BaO layers with BaO thickness is described. C1 NORTHWESTERN UNIV,DEPT CHEM,EVANSTON,IL 60208. ARGONNE NATL LAB,DIV MAT SCI,ARGONNE,IL 60439. RP Buchholz, DB (reprint author), NORTHWESTERN UNIV,DEPT MAT SCI & ENGN,EVANSTON,IL 60208, USA. RI Chang, R.P.H/B-7505-2009 NR 16 TC 2 Z9 2 U1 0 U2 3 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0925-8388 J9 J ALLOY COMPD JI J. Alloy. Compd. PD APR PY 1997 VL 251 IS 1-2 BP 278 EP 283 DI 10.1016/S0925-8388(96)02685-0 PG 6 WC Chemistry, Physical; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Chemistry; Materials Science; Metallurgy & Metallurgical Engineering GA XM340 UT WOS:A1997XM34000060 ER PT J AU Tanaka, T Aizawa, T Rowen, M Rek, ZU Kitajima, Y Higashi, I Wong, J Ishizawa, Y AF Tanaka, T Aizawa, T Rowen, M Rek, ZU Kitajima, Y Higashi, I Wong, J Ishizawa, Y TI Nature of the 1385.6 and 1438 eV positive glitches in the transmission function of the YB66 soft-X-ray monochromator SO JOURNAL OF APPLIED CRYSTALLOGRAPHY LA English DT Article ID DOUBLE-CRYSTAL MONOCHROMATOR; SYNCHROTRON-RADIATION; PERFORMANCE AB In the course of the development of the YB66 004 monochromator for soft-X-ray spectroscopy in the 1-2 keV region, two positive glitches at 1385.6 and 1438 eV have been observed in the transmission function of this material in a double-crystal configuration. The nature of these glitches has been elucidated using a combination of photoemission experiments, reflectivity measurements and anomalous scattering calculations. Analyses of these results show that these positive glitches are due to the transmission at an energy 3/2 times higher than the 004 reflection and correspond to the yttrium L-III and L-II absorption edges at 2080 and 2156 eV, respectively. Reflectivity measurements and structure-factor calculations for the 006 reflection confirm that these glitches are caused by the sharp reflectivity increases associated with anomalous scattering for the 006 reflection at the yttrium L-III and L-II absorption edges. C1 STANFORD SYNCHROTRON RADIAT LAB,STANFORD,CA 94309. NATL LAB HIGH ENERGY PHYS,PHOTON FACTORY,TSUKUBA,IBARAKI 305,JAPAN. INST PHYS & CHEM RES,WAKO,SAITAMA 35101,JAPAN. LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94551. RP Tanaka, T (reprint author), NATL INST RES INORGAN MAT,1-1 NAMIKI,TSUKUBA,IBARAKI 305,JAPAN. NR 17 TC 7 Z9 7 U1 0 U2 0 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 1997 VL 30 BP 87 EP 91 DI 10.1107/S0021889896010199 PN 2 PG 5 WC Chemistry, Multidisciplinary; Crystallography SC Chemistry; Crystallography GA WW377 UT WOS:A1997WW37700001 ER PT J AU Darovsky, A Kezerashvili, V AF Darovsky, A Kezerashvili, V TI Evaluation of the 'seed-skewness' method of peak integration SO JOURNAL OF APPLIED CRYSTALLOGRAPHY LA English DT Article AB Evaluation of the performance of a new peak-integration procedure was made by numerical methods based on the Monte Carlo simulation technique. This new procedure has the advantage of quantitative estimation of integration accuracy by comparison with the theoretical model which is free from experimental errors. RP Darovsky, A (reprint author), BROOKHAVEN NATL LAB,NATL SYNCHROTRON LIGHT SOURCE DEPT,SUNY X3 BEAMLINE,UPTON,NY 11973, USA. NR 3 TC 3 Z9 3 U1 0 U2 2 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 1997 VL 30 BP 128 EP 132 DI 10.1107/S0021889896012733 PN 2 PG 5 WC Chemistry, Multidisciplinary; Crystallography SC Chemistry; Crystallography GA WW377 UT WOS:A1997WW37700009 ER PT J AU Saxena, AM AF Saxena, AM TI The origin and minimization of the critical-angle reflection from a thin-film multilayer monochromator SO JOURNAL OF APPLIED CRYSTALLOGRAPHY LA English DT Article ID NI-TI MULTILAYERS; NEUTRON MONOCHROMATORS; SUPERMIRRORS; DIFFUSION AB A thin-film multilayer device, used as a monochromator for a white beam of neutrons, also reflects the long-wavelength component of the primary beam due to total reflection from the constituent materials of the multilayer and the substrate. This part of the spectrum consists of the primary beam's Aux for all wavelengths above a critical value, which depends on the characteristics of the multilayer and its angular setting. The presence of this component in the neutron beam map interfere with high-resolution structure determinations. Although there is no unique way of eliminating this contamination, the following approaches may be taken to minimize it: (i) using a multilayer with the smallest achievable periodicity; (ii) appropriately selecting the materials of the bilayer, substrate, and the number of layers to minimize total reflection; (iii) coating the multilayer with a 50-100 Angstrom thin layer of gadolinium; and (iv) installing a nickel-coated silicon plate to reflect the undesirable wavelengths away from the main beam. RP Saxena, AM (reprint author), BROOKHAVEN NATL LAB,DEPT BIOL,UPTON,NY 11973, USA. NR 14 TC 1 Z9 1 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 1997 VL 30 BP 138 EP 146 DI 10.1107/S002188989600893X PN 2 PG 9 WC Chemistry, Multidisciplinary; Crystallography SC Chemistry; Crystallography GA WW377 UT WOS:A1997WW37700011 ER PT J AU Soltis, SM Stowell, MHB Wiener, MC Phillips, GN Rees, DC AF Soltis, SM Stowell, MHB Wiener, MC Phillips, GN Rees, DC TI Successful flash-cooling of xenon-derivatized myoglobin crystals SO JOURNAL OF APPLIED CRYSTALLOGRAPHY LA English DT Article ID METMYOGLOBIN; PROTEINS AB This paper demonstrates for the first time a method for preparing cryocooled xenon-derivatized protein crystals. The method is based upon the hypothesis and subsequent observation that the diffusion of a xenon atom from a tight binding site following depressurization occurs on a timescale of minutes. We have observed significant changes in diffraction intensities from myoglobin crystals for up to 5 min following depressurization from 1 MPa of xenon. In accordance with this observation, a xenon-derivatized myoglobin crystal was cryocooled at similar to 95 K within 20 s of complete depressurization. A crystallographic data set was then collected to 2.0 Angstrom resolution and isomorphous and anomalous difference Patterson maps revealed the presence of a well ordered xenon site with an occupancy of approximately 0.5. Phasing statistics for this site were of good quality and demonstrate the practicality of this method The ability to cryocool xenon-derivatized crystals will make this heavy-atom substitution method even more useful for single-isomorphous-replacement and multiple-isomorphous-replacement phasing of macromolecules. C1 CALTECH,DIV CHEM & CHEM ENGN,PASADENA,CA 91125. UNIV CALIF SAN FRANCISCO,DEPT BIOCHEM & BIOPHYS,SAN FRANCISCO,CA 94143. RICE UNIV,DEPT BIOCHEM & CELL BIOL,HOUSTON,TX 77251. RICE UNIV,WM KECK CTR COMPUTAT BIOL,HOUSTON,TX 77251. RP Soltis, SM (reprint author), STANFORD UNIV,STANFORD LINEAR ACCELERATOR CTR,SYNCHROTRON RADIAT LAB,POB 4349,BIN 69,STANFORD,CA 94309, USA. NR 16 TC 40 Z9 40 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 1997 VL 30 BP 190 EP 194 DI 10.1107/S0021889896012939 PN 2 PG 5 WC Chemistry, Multidisciplinary; Crystallography SC Chemistry; Crystallography GA WW377 UT WOS:A1997WW37700020 ER PT J AU Felcher, GP Adenwalla, S Goyette, RJ AF Felcher, GP Adenwalla, S Goyette, RJ TI The effect of laboratory magnetic fields on neutron reflection SO JOURNAL OF APPLIED CRYSTALLOGRAPHY LA English DT Article AB Modest magnetic field gradients in the region of a reflecting sample surface (either magnetic or nonmagnetic) are sufficient to significantly perturb neutron reflectivity. Polarized neutron experiments on a 850 Angstrom-thick film of deuterated polystyrene on silicon showed a significant spin dependence of the reflectivity when the material was surrounded by magnetic circuitry that provided a transverse gradient (Delta B similar or equal to 0.004 MA m(-1) when integrated over the neutron path. The main effect of a field gradient is to modify the component of the neutron momentum perpendicular to the surface, k(z0), to k(z)(+/-) = (k(z0)(2) +/- c)(1/2). The sign indicates the neutron spin orientation relative to the applied field and c is proportional to Delta B. The effect may be of some use: the insertion of a known gradient around a nonmagnetic sample permits the set of measurements necessary to obtain the reflectivity of the sample not only in amplitude but also in phase. RP Felcher, GP (reprint author), ARGONNE NATL LAB,9700 S CASS AVE,ARGONNE,IL 60439, USA. NR 12 TC 0 Z9 0 U1 0 U2 0 PU MUNKSGAARD INT PUBL LTD PI COPENHAGEN PA 35 NORRE SOGADE, PO BOX 2148, DK-1016 COPENHAGEN, DENMARK SN 0021-8898 J9 J APPL CRYSTALLOGR JI J. Appl. Crystallogr. PD APR 1 PY 1997 VL 30 BP 195 EP 197 DI 10.1107/S0021889896013404 PN 2 PG 3 WC Chemistry, Multidisciplinary; Crystallography SC Chemistry; Crystallography GA WW377 UT WOS:A1997WW37700021 ER PT J AU Woolsey, NC Wark, JS AF Woolsey, NC Wark, JS TI Modeling of time resolved x-ray diffraction from laser-shocked crystals SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID WAVE COMPRESSION; STRESS WAVES; STRENGTH; FRACTURE; SILICON; LIF AB The rapid laser driven shock compression of solids is modeled using a hydrodynamic computer code. By postprocessing output from these simulations and using a new, efficient x-ray diffraction algorithm we calculate time-dependent x-ray diffraction images which can be directly compared with experimental x-ray diffraction data, The measurement of shock compression of crystalline solids by x-ray diffraction is illustrated with three examples, one a square wave, and two triangular waves. The development of these waves and the associated x-ray diffraction patterns are followed as the waves propagate through the crystalline solid and interact with a free surface. Simulated x-ray streak camera data created with this hydrodynamic-x-ray diffraction model are presented and are compared to experimental data. (C) 1997 American Institute of Physics. C1 LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94551. UNIV OXFORD,DEPT PHYS,CLARENDON LAB,OXFORD OX1 3PU,ENGLAND. NR 68 TC 12 Z9 12 U1 0 U2 2 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD APR 1 PY 1997 VL 81 IS 7 BP 3023 EP 3037 DI 10.1063/1.364337 PG 15 WC Physics, Applied SC Physics GA WT432 UT WOS:A1997WT43200017 ER PT J AU Duxstad, KJ Haller, EE Yu, KM AF Duxstad, KJ Haller, EE Yu, KM TI High temperature behavior of Pt and Pd on GaN SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID LIGHT-EMITTING-DIODES; FILMS; BLUE AB We report on the thermal stability of Pt and Pd thin films on GaN up to 800 degrees C. We have found that for Pt thin films submicron size metal spheres form at temperatures as low as 600 degrees C and the film turns into discontinuous islands at 725 degrees C and above. Pd begins to form islands above 700 degrees C and areas of the film begin to delaminate due to thermally generated compressive stress. The general behavior of these films is that found for most metal films on ceramics, suggesting that metals on GaN do not react as they typically do on common elemental and compound semiconductors. This ceramic-like behavior must be considered when determining which metals may act as good electrical contacts for GaN, especially for high temperature applications or alloyed contacts. (C) 1997 American Institute of Physics. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,BERKELEY,CA 94720. RP Duxstad, KJ (reprint author), UNIV CALIF BERKELEY,DEPT MAT SCI & MINERAL ENGN,BERKELEY,CA 94720, USA. RI Yu, Kin Man/J-1399-2012 OI Yu, Kin Man/0000-0003-1350-9642 NR 17 TC 36 Z9 36 U1 1 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 1997 VL 81 IS 7 BP 3134 EP 3137 DI 10.1063/1.364091 PG 4 WC Physics, Applied SC Physics GA WT432 UT WOS:A1997WT43200032 ER PT J AU Heller, CM Campbell, IH AF Heller, CM Campbell, IH TI Chemical potential pinning due to equilibrium electron transfer at metal/C-60-doped polymer interfaces SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID LIGHT-EMITTING-DIODES; C-60; C60 AB We report electroabsorption measurements of the built-in electrostatic potential in metal/ C-60-doped polymer/metal structures to investigate chemical potential pinning due to equilibrium electron transfer from a metal contact to the electron acceptor energy level of C-60 molecules in the polymer film. The built-in potentials of a series of structures employing thin films of both undoped and C-60-doped poly[2-methoxy, 5-(2'-ethyl-hexyloxy)-1,4-phenylene vinylene] (MEH-PPV) were measured. For undoped MEH-PPV, which has an energy gap of about 2.4 eV, the maximum built-in potential is about 2.1 eV, whereas for C-60-doped MEH-PPV the maximum built-in potential decreases to 1.5 eV. Electron transfer to the C-60 molecules close to the metal interface pins the chemical potential of the metal contact near the electron acceptor energy level of C-60 and decreases the built-in potential of the structure, From the systematic dependence of the built-in potential on the metal work function we find that the electron acceptor energy level of C-60 in MEH-PPV is about 1.7 eV above the hole polaron energy level of MEH-PPV. (C) 1997 American Institute of Physics. C1 UNIV TEXAS,RICHARDSON,TX 75080. GRAZ TECH UNIV,INST FESTKORPERPHYS,A-8010 GRAZ,AUSTRIA. RP Heller, CM (reprint author), LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545, USA. NR 14 TC 37 Z9 37 U1 0 U2 6 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 1997 VL 81 IS 7 BP 3227 EP 3231 DI 10.1063/1.364154 PG 5 WC Physics, Applied SC Physics GA WT432 UT WOS:A1997WT43200047 ER PT J AU Gao, Y Kim, YJ Thevuthasan, S Chambers, SA Lubitz, P AF Gao, Y Kim, YJ Thevuthasan, S Chambers, SA Lubitz, P TI Growth, structure, and magnetic properties of gamma-Fe2O3 epitaxial films on MgO SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID DIFFRACTION; SURFACES AB Single-crystal epitaxial thin films of gamma-Fe2O3(001) have been grown on MgO(001) using oxygen-plasma-assisted molecular beam epitaxy. The structure and magnetic properties of these films have been characterized by a variety of techniques, including reflection high-energy electron diffraction (RHEED), low-energy electron diffraction (LEED), x-ray photoelectron spectroscopy and x-ray photoelectron/Auger electron diffraction (XPD/AED), vibrating sample magnetometry, and ferromagnetic resonance. Real-time RHEED reveals that the film growth occurs in a layer-by-layer fashion. The gamma-Fe2O3(001) film surface exhibits a (1 x 1) LEED pattern. The growth of gamma-Fe2O3 films at 450 degrees C is accompanied by significant Mg outdiffusion. AED of Mg KLL Auger emission reveals that Mg substitutionally incorporates in the gamma-Fe2O3 lattice, occupying the octahedral sites. Magnetic moments are similar to 2300 G and similar to 4500 G for gamma-Fe2O3 films grown at 250 degrees C and 450 degrees C, respectively. The high magnetic moment for the films grown at 450 degrees C could be attributed to the high degree of structural order of the films and Mg substitution at octahedral sites. (C) 1997 American Institute of Physics. C1 USN,RES LAB,WASHINGTON,DC 20375. RP Gao, Y (reprint author), PACIFIC NW NATL LAB,ENVIRONM MOL SCI LAB,RICHLAND,WA 99352, USA. NR 19 TC 46 Z9 46 U1 2 U2 18 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 1997 VL 81 IS 7 BP 3253 EP 3256 DI 10.1063/1.364355 PG 4 WC Physics, Applied SC Physics GA WT432 UT WOS:A1997WT43200052 ER PT J AU McCune, W Wos, L AF McCune, W Wos, L TI Otter - The CADE-13 competition incarnations SO JOURNAL OF AUTOMATED REASONING LA English DT Article; Proceedings Paper CT Meeting for CADE-13 ATP System Competition CY AUG 01, 1996 CL RUTGERS UNIV, NEW BRUNSWICK, NJ SP Rutgers Univ HO RUTGERS UNIV DE automated theorem proving; competition; Otter; automated reasoning; equational deduction; paramodulation; resolution ID SINGLE AXIOMS; AUTOMATED DEDUCTION; COMBINATORY-LOGIC; EXPONENT GROUPS; OPEN QUESTIONS; SYSTEM AB This article discusses the two incarnations of Otter entered in the CADE-13 Automated Theorem Proving System Competition. Also presented are some historical background, a summary of applications that have led to new results in mathematics and logic, and a general discussion of Otter. C1 ARGONNE NATL LAB, DIV MATH & COMP SCI, ARGONNE, IL 60439 USA. NR 40 TC 24 Z9 25 U1 0 U2 2 PU SPRINGER PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0168-7433 EI 1573-0670 J9 J AUTOM REASONING JI J. Autom. Reasoning PD APR PY 1997 VL 18 IS 2 BP 211 EP 220 DI 10.1023/A:1005843632307 PG 10 WC Computer Science, Artificial Intelligence SC Computer Science GA XE726 UT WOS:A1997XE72600010 ER PT J AU Hahn, DW Wolfarth, DL Parks, NL AF Hahn, DW Wolfarth, DL Parks, NL TI Analysis of polyethylene wear debris using micro-Raman spectroscopy: A report on the presence of beta-carotene SO JOURNAL OF BIOMEDICAL MATERIALS RESEARCH LA English DT Article ID NORMAL-COORDINATE ANALYSIS; INFRARED BANDS; SEALANT FILMS; RABBIT KNEE; IMPLANTATION; SPECTRA; ISOMERS; ASSIGNMENTS; ANTIOXIDANT; PARTICLES AB This paper describes micro-Raman spectroscopy of ultrahigh molecular weight polyethylene wear debris isolated from revised knee replacements. The novel application of micro-Raman spectroscopy to the analysis of in vivo-generated wear debris was used to evaluate the chemical nature of individual, retrieved polyethylene particles. The analysis revealed the presence of beta-carotene on particles from both synovial fluid and tissue samples. Raman analysis of retrieved polyethylene tibial inserts also revealed localized beta-carotene signals within the primary wear region. In this paper, a mechanism is suggested that may account for the coupling of beta-carotene and polyethylene wear debris. We also discuss the origin of beta-carotene within the implanted joint and the implications that beta-carotene, an antioxidant, has for the overall host response to polyethylene orthopedic components. (C) 1997 John Wiley & Sons, Inc. C1 US FDA,CTR DEVICES & RADIOL HLTH,ROCKVILLE,MD 20857. ANDERSON ORTHOPAED RES INST,ARLINGTON,VA. RP Hahn, DW (reprint author), SANDIA NATL LABS,MS 9053,LIVERMORE,CA 94551, USA. NR 37 TC 13 Z9 13 U1 1 U2 6 PU JOHN WILEY & SONS INC PI NEW YORK PA 605 THIRD AVE, NEW YORK, NY 10158-0012 SN 0021-9304 J9 J BIOMED MATER RES JI J. Biomed. Mater. Res. PD APR PY 1997 VL 35 IS 1 BP 31 EP 37 DI 10.1002/(SICI)1097-4636(199704)35:1<31::AID-JBM4>3.0.CO;2-N PG 7 WC Engineering, Biomedical; Materials Science, Biomaterials SC Engineering; Materials Science GA WQ683 UT WOS:A1997WQ68300004 PM 9104696 ER PT J AU deSouza, ON Ornstein, RL AF deSouza, ON Ornstein, RL TI Effect of warmup protocol and sampling time on convergence of molecular dynamics simulations of a DNA dodecamer using AMBER 4.1 and Particle-Mesh Ewald method SO JOURNAL OF BIOMOLECULAR STRUCTURE & DYNAMICS LA English DT Article ID TATA-BINDING PROTEIN; MINOR-GROOVE; CRYSTAL-STRUCTURE; FORCE-FIELD; B-DNA; TBP; RNA; TRANSCRIPTION; YEAST; SYSTEMS AB This report describes one 3000 ps and two 1500 ps molecular dynamic simulations on a TATA box containing dodecamer DNA duplex in a periodic box of TIP3P water molecules, using the AMBER 4.1 implementation bf the particle-mesh Ewald method. We compare the effect of warmup protocol and simulation time length on the root-mean square deviation (RMSD) parameter. For the longer simulation, the RMSD computed for the 500-1000 ps time interval is representative of longer time intervals, including 500-3000 ps. The various warmup protocols do not appear to have a significant effect on the simulation results. Based on the present results, DNA sequence-dependent differences in RMSD, or related properties, should exceed two standard deviations before being attributed to non-simulation factors, such as warmup protocol and sampling time effects; we recommend a minimum criterion of at least a three standard deviation difference with a sampling period of at least 500-1000 ps. In addition, while end effects appear negligible there is a consistent dependence of RMSD on DNA helix length. C1 PACIFIC NW NATL LAB, ENVIRONM MOL SCI LAB, RICHLAND, WA 99352 USA. RI Norberto de Souza, Osmar/B-7328-2013 OI Norberto de Souza, Osmar/0000-0002-4602-1208 NR 25 TC 27 Z9 27 U1 0 U2 0 PU ADENINE PRESS INC PI GUILDERLAND PA PO BOX 355/340, GUILDERLAND, NY 12084 SN 0739-1102 J9 J BIOMOL STRUCT DYN JI J. Biomol. Struct. Dyn. PD APR PY 1997 VL 14 IS 5 BP 607 EP 611 PG 5 WC Biochemistry & Molecular Biology; Biophysics SC Biochemistry & Molecular Biology; Biophysics GA WW026 UT WOS:A1997WW02600007 ER PT J AU Zubkowski, JD Hall, T Valente, EJ Perry, DL Feliu, LA Garmon, J AF Zubkowski, JD Hall, T Valente, EJ Perry, DL Feliu, LA Garmon, J TI Structure of {Pb[S2CN(C2H5)(2)](2)(1,10-phenanthroline)}(2) SO JOURNAL OF CHEMICAL CRYSTALLOGRAPHY LA English DT Article DE structure; lead; dithiocarbamate; phenanthroline AB Lead (II) nitrate reacts with 1,10-phenanthroline and sodium diethyldithiocarbamate in water to produce yellow bisdiethyldithiocarbamato 1,10-phenanthroline lead(II). Crystals from water are triclinic, space group P (1) over bar (#2), a = 10.53(2) Angstrom, b = 11.050(12) degrees, c = 24.74 (3) Angstrom, alpha = 94.71 (9)degrees, beta = 98.15(11)degrees, gamma = 114.11(9)degrees, V = 2569(6) Angstrom(3), Z = 2. Each lead atom has approximate pentagonal pyramid coordination geometry through the nitrogens of a phenathroline and sulfurs of two dithiocarbamates. Additionally, complexes form loose dimers in which lead atoms are weakly coordinated to a sulfur in an adjacent complex. IR and proton nmr spectrum of the complex are consistent with the solid state structure. C1 MISSISSIPPI COLL,DEPT CHEM,CLINTON,MS 39058. UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,BERKELEY,CA 94720. UNIV METROPOLITANA,DEPT SCI & TECHNOL,RIO PIEDRAS,PR 00928. RP Zubkowski, JD (reprint author), JACKSON STATE UNIV,DEPT CHEM,JACKSON,MS 39217, USA. RI G, Neela/H-3016-2014 NR 15 TC 6 Z9 7 U1 0 U2 0 PU PLENUM PUBL CORP PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 SN 1074-1542 J9 J CHEM CRYSTALLOGR JI J. Chem. Crystallogr. PD APR PY 1997 VL 27 IS 4 BP 251 EP 255 DI 10.1007/BF02575964 PG 5 WC Crystallography; Spectroscopy SC Crystallography; Spectroscopy GA XK071 UT WOS:A1997XK07100009 ER PT J AU Glab, WL Glynn, PT Dehmer, PM Dehmer, JL Wang, KS McKoy, BV AF Glab, WL Glynn, PT Dehmer, PM Dehmer, JL Wang, KS McKoy, BV TI Rotationally resolved energy-dispersive photoelectron spectroscopy of H2O: Photoionization of the C(0,0,0) state at 355 nm SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID ENHANCED MULTIPHOTON IONIZATION; DYNAMICS; D2O AB Measured and calculated rotationally resolved photoelectron spectra for photoionization of low rotational levels of the (C) over tilde B-1(1) Rydberg state of water are reported. This is the first example of rotationally resolved photoionization spectra beyond the special cases of H-2, high-J levels, and threshold spectra. These spectra reveal very nonatomiclike behavior and, surprisingly, the influence of multiple Cooper minima in the photoelectron matrix elements. (C) 1997 American Institute of Physics. C1 ARGONNE NATL LAB,ARGONNE,IL 60439. CALTECH,NOYES LAB PHYS CHEM,PASADENA,CA 91125. RP Glab, WL (reprint author), TEXAS TECH UNIV,DEPT PHYS,POB 41051,LUBBOCK,TX 79409, USA. NR 14 TC 13 Z9 13 U1 0 U2 4 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD APR 1 PY 1997 VL 106 IS 13 BP 5779 EP 5782 DI 10.1063/1.473597 PG 4 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA WP839 UT WOS:A1997WP83900045 ER PT J AU Wang, TH Ciszek, TF AF Wang, TH Ciszek, TF TI Impurity segregation in LPE growth of silicon from Cu-Al solutions SO JOURNAL OF CRYSTAL GROWTH LA English DT Article; Proceedings Paper CT 10th American Conference on Crystal Growth/9th International Conference on Vapor Growth and Epitaxy CY AUG 04-09, 1996 CL VAIL, CO DE silicon crystal; liquid phase epitaxy; impurity segregation; Cu-Al interaction; surface segregation; Cu gettering; multi-component regular solution AB Al segregation at the solid-liquid interface and Cu segregation at the free silicon surface were studied in liquid-phase epitaxy (LPE) of silicon thin layers from mixtures of Cu-Al-Si. Using the multi-component regular solution model and experimental results, we found that Si-Al and Si-Cu interactions in the liquid solution are repulsive, and Al-Cu interaction is attractive. As a result, Al doping in silicon epitaxial layers is controlled by both Cu and Al compositions in the growth solution to allow epitaxy at about 900 degrees C, with a substantial amount of Al present in the liquid for substrate surface-oxide removal. On the other hand, Cu concentration in the grown layers is determined by both the solid-liquid interface segregation during growth and segregation at the silicon surface after growth. The surface segregation phenomenon can be used to getter Cu from the bulk of silicon layers so that its concentration is much lower than its solubility at the layer growth temperature and the reported 10(17) cm(-3) degradation onset for solar-cell performance. RP Wang, TH (reprint author), NATL RENEWABLE ENERGY LAB,1617 COLE BLVD,GOLDEN,CO 80401, USA. NR 8 TC 5 Z9 5 U1 0 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-0248 J9 J CRYST GROWTH JI J. Cryst. Growth PD APR PY 1997 VL 174 IS 1-4 BP 176 EP 181 DI 10.1016/S0022-0248(96)01101-3 PG 6 WC Crystallography; Materials Science, Multidisciplinary; Physics, Applied SC Crystallography; Materials Science; Physics GA XJ186 UT WOS:A1997XJ18600026 ER PT J AU Kolesnikov, NN Kolchin, AA Alov, DL Ivanov, YN Chernov, AA Schieber, M Hermon, H James, RB Goorsky, MS Yoon, H Toney, J Brunett, B Schlesinger, TE AF Kolesnikov, NN Kolchin, AA Alov, DL Ivanov, YN Chernov, AA Schieber, M Hermon, H James, RB Goorsky, MS Yoon, H Toney, J Brunett, B Schlesinger, TE TI Growth and characterization of p-type Cd1-xZnxTe (x=0.2, 0.3, 0.4) SO JOURNAL OF CRYSTAL GROWTH LA English DT Article; Proceedings Paper CT 10th American Conference on Crystal Growth/9th International Conference on Vapor Growth and Epitaxy CY AUG 04-09, 1996 CL VAIL, CO DE high pressure vertical Bridgman; Cd1-xZnxTe; semiconductor radiation detectors ID BRIDGMAN AB Single crystals of p-type semi-insulating Cd1-xZnxTe (CZT) with x = 0.2, 0.3 and 0.4 were grown using the high-pressure vertical Bridgman method. The crystals showed a high degree of axial homogeneity over most of the length of the ingot. The crystals were characterized by measuring the specific resistivity, X-ray spectral analysis, triaxial rocking curves, photoluminescence, etch-pit density and photocurrent kinetics. Despite the high homogeneity the photocurrent kinetics are worse than n-type CZT (x = 0.1 and 0.2) also grown by high-pressure vertical Bridgman. C1 SANDIA NATL LABS,DEPT 8230,LIVERMORE,CA 94550. RUSSIAN ACAD SCI,INST SOLID STATE PHYS,MOSCOW 142432,RUSSIA. RUSSIAN ACAD SCI,INST CRYSTALLOG,MOSCOW,RUSSIA. UNIV CALIF LOS ANGELES,LOS ANGELES,CA 90024. CARNEGIE MELLON UNIV,PITTSBURGH,PA 15213. NR 7 TC 23 Z9 25 U1 0 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-0248 J9 J CRYST GROWTH JI J. Cryst. Growth PD APR PY 1997 VL 174 IS 1-4 BP 256 EP 262 DI 10.1016/S0022-0248(96)01151-7 PG 7 WC Crystallography; Materials Science, Multidisciplinary; Physics, Applied SC Crystallography; Materials Science; Physics GA XJ186 UT WOS:A1997XJ18600039 ER PT J AU Contreras, MA Noufi, R AF Contreras, MA Noufi, R TI Chalcopyrite Cu(In,Ga)Se-2 and defect-chalcopyrite Cu(In,Ga)(3)Se-5 materials in photovoltaic P-N junctions SO JOURNAL OF CRYSTAL GROWTH LA English DT Article; Proceedings Paper CT 10th American Conference on Crystal Growth/9th International Conference on Vapor Growth and Epitaxy CY AUG 04-09, 1996 CL VAIL, CO DE chalcopyrite; photovoltaic; polycrystalline; thin film AB Efficient photovoltaic action in polycrystalline solar cells based on Cu-In-Ga-Se materials is postulated to rely strongly on a chalcopyrite/defect-chalcopyrite interface. Growth and fundamental properties of such materials are discussed to understand better junction formation in such devices. A change in conductivity type (from n to p) has been observed for the defect chalcopyrite materials with increased Ga content. Specifically, we found that the p-n nature of the interface in uniform Ga content absorbers is only possible at low Ga contents (< 30% relative to In). Furthermore, crystallographic data reveal significant differences in lattice size between both chalcopyrite materials as Ga is increased beyond 30% relative to In. RP NATL RENEWABLE ENERGY LAB, SERF W100-23, 1617 COLE BLVD, GOLDEN, CO 80401 USA. NR 10 TC 4 Z9 4 U1 0 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-0248 EI 1873-5002 J9 J CRYST GROWTH JI J. Cryst. Growth PD APR PY 1997 VL 174 IS 1-4 BP 283 EP 288 DI 10.1016/S0022-0248(96)01160-8 PG 6 WC Crystallography; Materials Science, Multidisciplinary; Physics, Applied SC Crystallography; Materials Science; Physics GA XJ186 UT WOS:A1997XJ18600044 ER PT J AU Lal, RB Zhang, HW Wang, WS Aggarwal, MD Lee, HWH Penn, BG AF Lal, RB Zhang, HW Wang, WS Aggarwal, MD Lee, HWH Penn, BG TI Crystal growth and optical properties of 4-aminobenzophenone crystals for NLO applications SO JOURNAL OF CRYSTAL GROWTH LA English DT Article; Proceedings Paper CT 10th American Conference on Crystal Growth/9th International Conference on Vapor Growth and Epitaxy CY AUG 04-09, 1996 CL VAIL, CO DE solution growth; Bridgman-Stockbarger growth; NLO materials; 4-aminobenzophenone ABP ID 2ND-HARMONIC GENERATION; CZOCHRALSKI AB Single crystals of 4-aminobenzophenone, a nonlinear optical(NLO) material have been grown successfully by a novel solution growth as well as modified Bridgman-Stockbarger techniques. The transmission spectrum (420-1400 nm) and SHG efficiencies were determined. 4-Aminobenzophenone crystals gave a lower limit on the second harmonic generation (SHG) efficiency of 10%. Laser damage threshold measurements conducted at the indicated wavelengths gave values of 1-2 GW/cm(2). C1 LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94551. NASA,GEORGE C MARSHALL SPACE FLIGHT CTR,HUNTSVILLE,AL 35812. RP Lal, RB (reprint author), ALABAMA A&M UNIV,DEPT PHYS,NORMAL,AL 35762, USA. NR 13 TC 11 Z9 12 U1 0 U2 0 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 1997 VL 174 IS 1-4 BP 393 EP 397 DI 10.1016/S0022-0248(96)01134-7 PG 5 WC Crystallography; Materials Science, Multidisciplinary; Physics, Applied SC Crystallography; Materials Science; Physics GA XJ186 UT WOS:A1997XJ18600062 ER PT J AU Gao, Y Chambers, SA AF Gao, Y Chambers, SA TI Heteroepitaxial growth of alpha-Fe2O3, gamma-Fe2O3 and Fe3O4 thin films by oxygen-plasma-assisted molecular beam epitaxy SO JOURNAL OF CRYSTAL GROWTH LA English DT Article; Proceedings Paper CT 10th American Conference on Crystal Growth/9th International Conference on Vapor Growth and Epitaxy CY AUG 04-09, 1996 CL VAIL, CO DE molecular beam epitaxy; iron oxide; epitaxial thin film ID IRON-OXIDE; MICROSCOPY AB We have grown epitaxial alpha-Fe2O3(0001) thin films on Pt(111)/alpha-Al2O3(0001), and gamma-Fe(2)O3(001) and Fe3O4(001) thin films on MgO(001) by molecular beam epitaxy using an elemental Fe source and an electron cyclotron resonance oxygen plasma source. These iron oxide thin films are single crystals with excellent crystalline quality. Use of a Pt(111) buffer layer for growth of alpha-Fe2O3(0001) on alpha-Al2O3(0001) improves the crystal quality for epitaxial alpha-Fe2O3(0001) films. Growth of epitaxial alpha-Fe2O3 and gamma-Fe2O3 films under the same growth conditions, but on different substrates, suggests that it is possible to grow a thermodynamically unstable or metastable phase such as gamma-Fe2O3 by selecting a suitable substrate (e.g. small lattice mismatch and similar surface symmetry). The alpha-Fe2O3(0001) and gamma-Fe2O3(001) film surfaces ar; unreconstructed whereas the Fe3O4(001) film surface exhibits a (root 2x root 2)R45 degrees reconstruction. Application of a simple electron counting rule reveals that the bulk-terminated alpha-Fe2O3(0001) and gamma-Fe2O3(001) surfaces are autocompensated, but the bulk-terminated Fe3O4(001) surface is not. The reconstruction is due to the formation of an ordered array of tetrahedral iron vacancies required to achieve surface charge neutralization. RP Gao, Y (reprint author), PACIFIC NW LAB, POB 999, MS K2-12, RICHLAND, WA 99352 USA. NR 12 TC 120 Z9 120 U1 3 U2 39 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 1997 VL 174 IS 1-4 BP 446 EP 454 DI 10.1016/S0022-0248(96)01141-4 PG 9 WC Crystallography; Materials Science, Multidisciplinary; Physics, Applied SC Crystallography; Materials Science; Physics GA XJ186 UT WOS:A1997XJ18600069 ER PT J AU Hawley, ME Adams, CD Arendt, PN Brosha, EL Garzon, FH Houlton, RJ Hundley, MF Heffner, RH Jia, QX Neumeier, J Wu, XD AF Hawley, ME Adams, CD Arendt, PN Brosha, EL Garzon, FH Houlton, RJ Hundley, MF Heffner, RH Jia, QX Neumeier, J Wu, XD TI CMR films structure as a function of growth and processing SO JOURNAL OF CRYSTAL GROWTH LA English DT Article; Proceedings Paper CT 10th American Conference on Crystal Growth/9th International Conference on Vapor Growth and Epitaxy CY AUG 04-09, 1996 CL VAIL, CO DE STM; CMR; transport; magnetization; La0.67Ca0.35MnO3; growth; films ID DEFECT CHEMISTRY; LAMNO3+/-DELTA; MAGNETORESISTANCE; LAMNO3+DELTA; TEMPERATURE AB Among the family encompassed by the complex metal oxides are the colossal magneto-resistive perovskites with potential applications in advanced high density magnetic data storage and sensor devices based on single or multilayers of these materials fabricated by vapor phase deposition methods. Realization of this potential requires solving basic thin film fabrication problems coupled to understanding the resulting structure-properties relationships. The specific objectives addressed in this study were to determine the dependence of growth and transport properties: (1) reproducibility on the pulsed laser deposition (PLD) target, (2) on sputter deposition chamber gas and substrate, and (3) on a post-deposition anneal in a reducing atmosphere. Toward these ends, we have grown La0.67Ca0.33MnO3 films on perovskite substrates by PLD and RF off-axis sputter deposition from stoichiometric targets at temperatures from 400 to 900 degrees C. The PLD films were grown from a new commercial target and post-deposition annealed in O-2 to reproduce, for comparison, the conditions used previously for the films grown with an in-house fabricated target. The sputter deposited films were grown in both Ar-O-2 mixed and Ar-only atmospheres, some grown simultaneously on different substrates; one Ar-O-2 grown film was post-annealed in a reducing atmosphere. Microstructures were studied by scanning probe microscopies and temperature-dependent transport properties by 4-point resistance measurements. Previously we reported on characterization of the T-substrate(T-s)-dependent microstructure of PLD as-deposited and post-annealed films consistency in T-dependent transport and magnetization properties, independent of growth temperature. None of the as-grown sputter deposited films grown in the Ar-O-2 mixture exhibited a metallic transition while those grown in Ar-only at T-s > 800 degrees C had a range of transition temperatures between 110 and 180 K. The variation in substrate-dependent structure demonstrated again the sensitivity of growth mechanism to template. Finally, the 500 degrees C film grown in the Ar-O-2 mixture, went from insulating at all T's to exhibiting a 215 degrees C metallic transition after the reducing anneal treatment. C1 LOS ALAMOS NATL LAB,DIV MAT SCI & TECHNOL,LOS ALAMOS,NM 87545. RP Hawley, ME (reprint author), LOS ALAMOS NATL LAB,CTR MAT SCI,MS K765,LOS ALAMOS,NM 87545, USA. RI Jia, Q. X./C-5194-2008 NR 11 TC 19 Z9 19 U1 0 U2 7 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 1997 VL 174 IS 1-4 BP 455 EP 463 DI 10.1016/S0022-0248(96)01142-6 PG 9 WC Crystallography; Materials Science, Multidisciplinary; Physics, Applied SC Crystallography; Materials Science; Physics GA XJ186 UT WOS:A1997XJ18600070 ER PT J AU Luo, JS Geisz, JF Olson, JM Wu, MC AF Luo, JS Geisz, JF Olson, JM Wu, MC TI Surface-related optical anisotropy of GaInP, InP, and GaP SO JOURNAL OF CRYSTAL GROWTH LA English DT Article; Proceedings Paper CT 10th American Conference on Crystal Growth/9th International Conference on Vapor Growth and Epitaxy CY AUG 04-09, 1996 CL VAIL, CO DE reflectance difference spectroscopy ID REFLECTANCE-DIFFERENCE SPECTROSCOPY; CHEMICAL VAPOR-DEPOSITION; GAAS; DESORPTION AB We have studied the optical anisotropy induced by the (0 0 1) surface reconstruction of GaInP, InP, and GaP annealed under various gas environments in an atmospheric-pressure metal-organic chemical vapor deposition system using reflectance difference spectroscopy (RDS). The RD spectra of InP under a PH3 partial pressure of 10 Torr in a carrier of H-2 between 500 degrees C and 400 degrees C are consistent with a (2 x 1) surface reconstruction. As the temperature of the InP is lowered to 200 degrees C under PH3, the signature of the RD spectrum changes. If the flow of PH3 is removed when the InP cools to 300 degrees C, the RD spectrum remains consistent with the (2 x 1) surface reconstruction down to room temperature. When InP is annealed at 400 degrees C in hydrogen, the RD spectrum becomes consistent with a (2 x 4) surface reconstruction. The temperature-dependent RD spectra of GaInP are very similar to those of InP. The RD spectra of GaP reveal that the P-terminated surface of GaP observed at high temperatures is more stable then either InP or GaInP surfaces in the absence of PH,. The features of these surface related RD spectra are quickly quenched in air and, under some conditions, nitrogen. This observation is important for studies of bulk-related, ordering-induced optical anisotropy in GaInP. C1 NATL RENEWABLE ENERGY LAB, GOLDEN, CO 80401 USA. NATL TSING HUA UNIV, HSINCHU 30043, TAIWAN. RI Schaff, William/B-5839-2009 NR 17 TC 11 Z9 11 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-0248 EI 1873-5002 J9 J CRYST GROWTH JI J. Cryst. Growth PD APR PY 1997 VL 174 IS 1-4 BP 558 EP 563 DI 10.1016/S0022-0248(97)00041-9 PG 6 WC Crystallography; Materials Science, Multidisciplinary; Physics, Applied SC Crystallography; Materials Science; Physics GA XJ186 UT WOS:A1997XJ18600084 ER PT J AU Breiland, WG Hou, HQ Chui, HC Hammons, BE AF Breiland, WG Hou, HQ Chui, HC Hammons, BE TI In situ pre-growth calibration using reflectance as a control strategy for MOCVD fabrication of device structures SO JOURNAL OF CRYSTAL GROWTH LA English DT Article; Proceedings Paper CT 10th American Conference on Crystal Growth/9th International Conference on Vapor Growth and Epitaxy CY AUG 04-09, 1996 CL VAIL, CO DE MOCVD; reflectance; in situ; virtual interface; VCSEL ID FILMS AB In situ normal incidence reflectance, combined with a virtual interface model, is being used routinely on a commercial metal organic chemical vapor deposition reactor to measure growth rates of compound semiconductor films. The technique serves as a pre-growth calibration tool analogous to the use of reflection high-energy electron diffraction in molecular beam epitaxy as well as a real-time monitor throughout the run. An application of the method to the growth of a vertical cavity surface emitting laser (VCSEL) device structure is presented. All necessary calibration information can be obtained using a single run lasting less than 1 h. Working VCSEL devices are obtained on the first try after calibration. Repeated runs have yielded +/-0.3% reproducibility of the Fabry-Perot cavity wavelength over the course of more than 100 runs. RP Breiland, WG (reprint author), SANDIA NATL LABS,DEPT 1126,MS 0601,ALBUQUERQUE,NM 87185, USA. NR 6 TC 18 Z9 18 U1 2 U2 7 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 1997 VL 174 IS 1-4 BP 564 EP 571 DI 10.1016/S0022-0248(97)00020-1 PG 8 WC Crystallography; Materials Science, Multidisciplinary; Physics, Applied SC Crystallography; Materials Science; Physics GA XJ186 UT WOS:A1997XJ18600085 ER PT J AU Biefeld, RM Allerman, AA Kurtz, SR AF Biefeld, RM Allerman, AA Kurtz, SR TI The growth of mid-infrared lasers and AlAsxSb1-x by MOCVD SO JOURNAL OF CRYSTAL GROWTH LA English DT Article; Proceedings Paper CT 10th American Conference on Crystal Growth/9th International Conference on Vapor Growth and Epitaxy CY AUG 04-09, 1996 CL VAIL, CO ID CHEMICAL-VAPOR-DEPOSITION; PHASE EPITAXIAL-GROWTH AB We have grown AlSb and AlAsxSb1-x epitaxial layers by metal-organic chemical vapor deposition (MOCVD) using trimethylamine alane or ethyldimethylamine alane, triethylantimony, and arsine. These layers were successfully doped por n-type using diethylzinc or tetraethyltin, respectively. We examined the growth of AlAsxSb1-x using temperatures of 500-600 degrees C, pressures of 65-630 Torr, V/III ratios of 1-17, and growth rates of 0.3-2.7 mu m/h in a horizontal quartz reactor. We have also fabricated gain-guided, injection lasers using AlAsxSb1-x for optical confinement and a strained InAsSb/InAs multi-quantum well active region grown using MOCVD. In pulsed mode, the laser operated up to 210 K with an emission wavelength of 3.8-3.9 mu m. RP Biefeld, RM (reprint author), SANDIA NATL LABS,DEPT 1113,ALBUQUERQUE,NM 87185, USA. NR 17 TC 12 Z9 12 U1 1 U2 2 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 1997 VL 174 IS 1-4 BP 593 EP 598 DI 10.1016/S0022-0248(97)00019-5 PG 6 WC Crystallography; Materials Science, Multidisciplinary; Physics, Applied SC Crystallography; Materials Science; Physics GA XJ186 UT WOS:A1997XJ18600089 ER PT J AU Hanna, MC Lu, ZH Cahill, AF Heben, MJ Nozik, AJ AF Hanna, MC Lu, ZH Cahill, AF Heben, MJ Nozik, AJ TI MOCVD growth and optical characterization of strain-induced quantum dots with InP island stressors SO JOURNAL OF CRYSTAL GROWTH LA English DT Article; Proceedings Paper CT 10th American Conference on Crystal Growth/9th International Conference on Vapor Growth and Epitaxy CY AUG 04-09, 1996 CL VAIL, CO DE MOCVD; quantum dots; InP islands; Stranski-Krastanow; photoluminescence; atomic force microscopy ID MICROSTRUCTURAL EVOLUTION; WELL; CONFINEMENT; INXGA1-XAS; SI(100); GAAS; GE AB Coherent InP islands, grown by low pressure metal organic chemical vapor deposition (MOCVD), were used to produce quantum dots by strain confinement. Lateral confinement of carriers in a GaAs/AlGaAs quantum well located near the surface was obtained from the inhomogeneous strain produced by the InP islands. The evolution of the InP islands on Al0.3Ga0.7As surfaces with increasing InP coverage at different growth temperatures and substrate orientations was studied using atomic force microscopy. Under certain growth conditions, a fairly uniform distribution of coherent InP islands was obtained which had an average apparent diameter of 140 nm with a standard deviation of 12.2 nm and height of 19.5 +/- 1.1 nm. Lateral confinement depths up to 100 meV were obtained when using the islands as stressors. Photoluminescence from ensembles of the strain-induced dots exhibit multiple peaks, narrow line widths (16 meV) and high efficiency up to room temperature. RP Hanna, MC (reprint author), NATL RENEWABLE ENERGY LAB,1617 COLE BLVD,GOLDEN,CO 80401, USA. NR 20 TC 9 Z9 9 U1 0 U2 1 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 1997 VL 174 IS 1-4 BP 605 EP 610 DI 10.1016/S0022-0248(97)00029-8 PG 6 WC Crystallography; Materials Science, Multidisciplinary; Physics, Applied SC Crystallography; Materials Science; Physics GA XJ186 UT WOS:A1997XJ18600091 ER PT J AU Burtman, V Schieber, M Yitzchaik, S Yaroslavsky, Y AF Burtman, V Schieber, M Yitzchaik, S Yaroslavsky, Y TI Kinetics of evaporation of barium THD precursors used for organometallic chemical vapor deposition (OMCVD) thin films. SO JOURNAL OF CRYSTAL GROWTH LA English DT Article; Proceedings Paper CT 10th American Conference on Crystal Growth/9th International Conference on Vapor Growth and Epitaxy CY AUG 04-09, 1996 CL VAIL, CO DE OMCVD; barium precursor; kinetics of evaporation; NMR spectroscopy ID BETA-DIKETONATE COMPLEXES AB Various methods have been used to synthesize Ba(THD)(2) and its molecular structure has been studied using nuclear magnetic resonance. Compared with Raman and infrared spectroscopy it was found that NMR is very useful to determine quantitatively the decomposition through aging of Ba(THD)(2). The transport kinetics of Ba(THD)(2) has been studied under experimental conditions of a OMCVD reactor. It has been found that the freshly prepared Ba(THD)(2) by the reaction of Ba metal with THD ligand in anhydrous conditions with subsequent crystallization from methanol transported quantitatively without decomposition. A simple model shows that the transport kinetics corresponds to a diffusion controlled process. C1 HEBREW UNIV JERUSALEM,SCH APPL SCI,IL-91904 JERUSALEM,ISRAEL. LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550. RP Burtman, V (reprint author), HEBREW UNIV JERUSALEM,DEPT INORGAN CHEM,IL-91904 JERUSALEM,ISRAEL. NR 11 TC 9 Z9 9 U1 1 U2 1 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 1997 VL 174 IS 1-4 BP 801 EP 805 DI 10.1016/S0022-0248(97)00021-3 PG 5 WC Crystallography; Materials Science, Multidisciplinary; Physics, Applied SC Crystallography; Materials Science; Physics GA XJ186 UT WOS:A1997XJ18600123 ER PT J AU Zhang, CM Bartelt, MC Wen, JM Jenks, CJ Evans, JW Thiel, PA AF Zhang, CM Bartelt, MC Wen, JM Jenks, CJ Evans, JW Thiel, PA TI The initial stages of Ag/Ag(100) homoepitaxy: Scanning tunneling microscopy experiments and Monte Carlo simulations SO JOURNAL OF CRYSTAL GROWTH LA English DT Article; Proceedings Paper CT 10th American Conference on Crystal Growth/9th International Conference on Vapor Growth and Epitaxy CY AUG 04-09, 1996 CL VAIL, CO DE silver; epitaxy; scanning tunneling microscopy; nucleation; kinetic roughening; surface diffusion ID ENERGY-ELECTRON-DIFFRACTION; EPITAXIAL-GROWTH; NUCLEATION; AG(100); AG; COALESCENCE; MORPHOLOGY; DIFFUSION; CU(100); BARRIER AB Results are presented of a scanning tunneling microscopy study of Ag/Ag(100) homoepitaxy. We examine both submonolayer nucleation and growth of two-dimensional islands, for temperatures between 295 and 370 K, and the initial stages of multilayer kinetic roughening at 295 K. Comparison with results of Monte Carlo simulations for an appropriate model for metal(100) homoepitaxy produces estimates of 330 +/- 5 meV for the terrace diffusion barrier, and an effective value of 30 +/- 5 meV for the additional step-edge barrier (assuming a common prefactor of 10(12)/s). We also assess adatom-adatom bonding by analyzing the transition from irreversible to reversible island formation. C1 IOWA STATE UNIV,INST PHYS RES & TECHNOL,DEPT CHEM,AMES,IA 50011. IOWA STATE UNIV,INST PHYS RES & TECHNOL,DEPT MATH,AMES,IA 50011. IOWA STATE UNIV,AMES LAB,AMES,IA 50011. NR 31 TC 19 Z9 19 U1 0 U2 4 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 1997 VL 174 IS 1-4 BP 851 EP 857 DI 10.1016/S0022-0248(97)00063-8 PG 7 WC Crystallography; Materials Science, Multidisciplinary; Physics, Applied SC Crystallography; Materials Science; Physics GA XJ186 UT WOS:A1997XJ18600130 ER PT J AU Fabietti, LM Trivedi, R AF Fabietti, LM Trivedi, R TI In situ observations of stress-induced defect formation at the solid-liquid interface SO JOURNAL OF CRYSTAL GROWTH LA English DT Article ID GARNET SINGLE-CRYSTALS; DIRECTIONAL SOLIDIFICATION; GROWTH; TRANSITION; PLANAR; ENERGY AB Directional solidification experiments have been carried out to examine in situ the stress generated at the interface which lead to the formation of defects. A transparent system, which is also birefringence, is selected for the study to observe simultaneously both the morphology of the interface and the stress fringes. For a cusp orientation, the instability of the interface is shown to give rise to stress generation, and when sufficient stress accumulates, a grain boundary is formed to relieve the stress. A stress-induced parallel grain boundary formation is shown to be the mechanism for planar-to-cellular interface transition. The same mechanism is shown to cause cellular tip splitting to adjust the cellular spacing. A simple model of stress generation due to concentration gradients near the perturbed interface is developed to show the possible mechanism of stress generation. C1 IOWA STATE UNIV SCI & TECHNOL,AMES LAB,US DOE,AMES,IA 50011. IOWA STATE UNIV SCI & TECHNOL,DEPT MAT SCI & ENGN,AMES,IA 50011. UNIV NACL CORDOBA,CONSEJO NACL INVEST CIENT & TECN,FAC MATEMAT ASTRON & FIS,RA-5000 CORDOBA,ARGENTINA. NR 25 TC 11 Z9 11 U1 2 U2 10 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 1997 VL 173 IS 3-4 BP 503 EP 512 DI 10.1016/S0022-0248(96)00840-8 PG 10 WC Crystallography; Materials Science, Multidisciplinary; Physics, Applied SC Crystallography; Materials Science; Physics GA XC981 UT WOS:A1997XC98100035 ER PT J AU Len, PM Zhang, F Thevuthasan, S Kaduwela, AP Fadley, CS VanHove, MA AF Len, PM Zhang, F Thevuthasan, S Kaduwela, AP Fadley, CS VanHove, MA TI Optimal atomic imaging by photoelectron holography SO JOURNAL OF ELECTRON SPECTROSCOPY AND RELATED PHENOMENA LA English DT Article DE atomic imaging; photoelectron holography ID ELECTRON-EMISSION HOLOGRAPHY; SURFACE PHASE-TRANSITION; DIFFRACTION PATTERNS; MULTIPLE-SCATTERING; AUGER-ELECTRON; STRUCTURAL DETERMINATION; IMAGES; RECONSTRUCTION; INTENSITIES; INVERSION AB Several recent papers have dealt with the question of whether large-scale photoelectron diffraction data spanning a significant range in both angle and wavenumber can be analyzed as holograms so as to produce directly three-dimensional images of near-surface atomic structure. Data are thus taken over some volume in the photoelectron wavevector k-space, and then transformed to obtained atomic images. In this work, we review four analysis methods proposed to date for deriving atomic positions directly from photoelectron diffraction data and consider the application of them to theoretical diffraction patterns calculated from various single-scattering model clusters. This permits some general conclusions as to domains of applicability and the optimization of k-space sampling so as to minimize data acquisition time, while still assuring atomic images that are free of coarse k-sampling aberrations. We conclude that holographic imaging of atoms does not require exceedingly large photoelectron diffraction data sets, with a few thousand data points being a suitable minimum, and we also comment on the relative merits of the four different imaging algorithms. (C) 1997 Elsevier Science B.V. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV MAT SCI,BERKELEY,CA 94720. RP Len, PM (reprint author), UNIV CALIF DAVIS,DEPT PHYS,DAVIS,CA 95616, USA. RI Van Hove, Michel/A-9862-2008; OI Van Hove, Michel/0000-0002-8898-6921; Kaduwela, Ajith/0000-0002-7236-2698 NR 47 TC 10 Z9 11 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0368-2048 J9 J ELECTRON SPECTROSC JI J. Electron Spectrosc. Relat. Phenom. PD APR PY 1997 VL 85 IS 1-2 BP 145 EP 158 DI 10.1016/S0368-2048(97)00034-0 PG 14 WC Spectroscopy SC Spectroscopy GA XK875 UT WOS:A1997XK87500016 ER PT J AU Osborne, NR Graves, GA Ferber, MK AF Osborne, NR Graves, GA Ferber, MK TI Dynamic fatigue testing of candidate ceramic materials for turbine engines to determine slow-crack-growth parameters SO JOURNAL OF ENGINEERING FOR GAS TURBINES AND POWER-TRANSACTIONS OF THE ASME LA English DT Article; Proceedings Paper CT 40th International Gas Turbine and Aeroengine Congress and Exhibition CY JUN 05-08, 1995 CL HOUSTON, TX AB The purpose of this study was to evaluate the mechanical strength and slow-crack-growth parameter values for two commercially available silicon nitrides, SN-88 and NT164, at three high-temperature conditions, Weibull analysis and dynamic fatigue slow-crack-growth parameters were used to characterize the material strength and resistance to slow crack growth at high temperatures for Else in life prediction models. Although both materials are commercially available Si3N4, their high-temperature behavior was found to be significantly different. C1 OAK RIDGE NATL LAB,HIGH TEMP MAT LAB,OAK RIDGE,TN 37831. RP Osborne, NR (reprint author), UNIV DAYTON,RES INST,DIV MET & CERAM,DAYTON,OH 45469, USA. NR 5 TC 2 Z9 2 U1 0 U2 1 PU ASME-AMER SOC MECHANICAL ENG PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 SN 0742-4795 J9 J ENG GAS TURB POWER JI J. Eng. Gas. Turbines Power-Trans. ASME PD APR PY 1997 VL 119 IS 2 BP 273 EP 278 DI 10.1115/1.2815570 PG 6 WC Engineering, Mechanical SC Engineering GA WW751 UT WOS:A1997WW75100002 ER PT J AU Richards, GA Yip, MJ Robey, E Cowell, L Rawlins, D AF Richards, GA Yip, MJ Robey, E Cowell, L Rawlins, D TI Combustion oscillation control by cyclic fuel injection SO JOURNAL OF ENGINEERING FOR GAS TURBINES AND POWER-TRANSACTIONS OF THE ASME LA English DT Article; Proceedings Paper CT 40th International Gas Turbine and Aeroengine Congress and Exhibition CY JUN 05-08, 1995 CL HOUSTON, TX ID ACTIVE CONTROL; FLOW AB A number of recent articles have demonstrated the use of active control to mitigate the effects of combustion instability in afterburner and dump combustor applications. In these applications, cyclic injection of small quantities of control fuel has been proposed to counteract the periodic heat release that contributes to undesired pressure oscillations. This same technique may also be useful to mitigate oscillations in gas turbine combustors, especially in test rig combustors characterized by acoustic modes that do not exist in the final engine configuration To address this issue, the present paper reports on active control of a subscale, atmospheric pressure nozzle/combustor arrangement. The fuel is natural gas. Cyclic injection of 14 percent control fuel in a premix fuel nozzle is shown to reduce oscillating pressure amplitude by a factor of 0.30 (i.e., -10 dB) at 300 HZ. Measurement of the oscillating heat release is also reported. C1 SOLAR TURBINES INC,SAN DIEGO,CA. RP Richards, GA (reprint author), US DOE,MORGANTOWN ENERGY TECHNOL CTR,EG&G TECH SERV,POB 880,MORGANTOWN,WV 26505, USA. NR 12 TC 14 Z9 14 U1 0 U2 5 PU ASME-AMER SOC MECHANICAL ENG PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 SN 0742-4795 J9 J ENG GAS TURB POWER JI J. Eng. Gas. Turbines Power-Trans. ASME PD APR PY 1997 VL 119 IS 2 BP 340 EP 343 DI 10.1115/1.2815580 PG 4 WC Engineering, Mechanical SC Engineering GA WW751 UT WOS:A1997WW75100011 ER PT J AU Margolis, SB AF Margolis, SB TI A deflagration analysis of porous energetic materials with two-phase flow and a multiphase sequential reaction mechanism SO JOURNAL OF ENGINEERING MATHEMATICS LA English DT Article DE deflagration; two-phase flow; porous materials; activation energy; asymptotics ID 2-PHASE FLOW; STABILITY; FLAMES AB A theoretical analysis for the unconfined deflagration of a porous energetic material is developed for a two-step global reaction mechanism that consists of the condensed-phase combustion of the reactive material to produce gas-phase intermediates, followed by a gas-phase reaction that produces final gas-phase products. An asymptotic approach is employed, leading to explicit formulas for the deflagration velocity in specific parameter regimes. The results clearly indicate the influences of two-phase flow and the multiphase, multi-step chemistry on the burning rate, and serve to further characterize the combustion behavior of a significant class of degraded nitramine-type propellants for which the present analysis is applicable. RP Margolis, SB (reprint author), SANDIA NATL LABS,COMBUST RES FACIL,LIVERMORE,CA 94551, USA. NR 19 TC 2 Z9 2 U1 0 U2 2 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0022-0833 J9 J ENG MATH JI J. Eng. Math. PD APR PY 1997 VL 31 IS 2-3 BP 173 EP 203 DI 10.1023/A:1004239528221 PG 31 WC Engineering, Multidisciplinary; Mathematics, Interdisciplinary Applications SC Engineering; Mathematics GA XJ402 UT WOS:A1997XJ40200006 ER PT J AU Johnson, JR Cheng, CZ AF Johnson, JR Cheng, CZ TI Global structure of mirror modes in the magnetosheath SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID CYCLOTRON ANISOTROPY INSTABILITIES; LOW-FREQUENCY FLUCTUATIONS; PLASMA DEPLETION LAYER; EARTHS MAGNETOSHEATH; TERRESTRIAL MAGNETOSHEATH; DAYSIDE MAGNETOPAUSE; WAVES; SIMULATIONS; FIELD AB A global stability analysis of mirror modes in the magnetosheath is presented. The analysis is based upon the kinetic-MHD formulation which includes relevant kinetic effects such as Landau resonance and gradient drift effects related to inhomogeneities in the background density, temperature, pressure and its anisotropy, magnetic field, and plasma flow velocity. Pressure anisotropy provides the free energy for the global mirror mode. The local theory of mirror modes predicts purely growing modes in the frame of the moving plasma confined to the unstable magnetosheath region; however, the nonlocal theory that includes the effects of gradients and plasma flow predicts modes with real frequency which propagate with the flow from the magnetosheath toward the magnetopause boundary. The real frequency is of the order of a combination of the diamagnetic drift frequency and the Doppler shift frequency associated with plasma flow. The real frequency is not simply a Doppler-shifted frequency obtained from local calculation. Rather, it is determined from a boundary value constraint on an eigenvalue problem and can differ significantly from the local Doppler-shifted frequency. Without plasma flow, the diamagnetic drift frequency provides a wave phase velocity in the direction of the magnetopause so that wave energy accumulates against the magnetopause boundary, and the amplitude is skewed in that direction. Such a wave structure might be observed under conditions of small magnetosheath flow. For larger plasma flow (Alfven Mach number greater than or equal to 0.1), the flow also causes a real phase velocity in the direction of the flow, but the phase velocity increases from a small value near the bow shock to nearly the flow velocity as the wave propagates toward the magnetopause. As a result, wave amplitude is large where the phase velocity is small and small where the phase velocity is large resulting in a skew in wave amplitude toward the bow shock. RP Johnson, JR (reprint author), PRINCETON UNIV,PRINCETON PLASMA PHYS LAB,POB 451,PRINCETON,NJ 08543, USA. RI Cheng, Chio/K-1005-2014 NR 27 TC 30 Z9 30 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 J9 J GEOPHYS RES-SPACE JI J. Geophys. Res-Space Phys. PD APR 1 PY 1997 VL 102 IS A4 BP 7179 EP 7189 DI 10.1029/96JA03949 PG 11 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA WR367 UT WOS:A1997WR36700016 ER PT J AU Rinehart, TL Schulze, DG Bricka, RM Bajt, S Blatchley, ER AF Rinehart, TL Schulze, DG Bricka, RM Bajt, S Blatchley, ER TI Chromium leaching vs. oxidation state for a contaminated solidified/stabilized soil SO JOURNAL OF HAZARDOUS MATERIALS LA English DT Article DE chromium; contaminated soil; solidification/stabilization ID CHROMATE AB The toxicity, solubility, and mobility of chromium in soil are strongly dependent upon its oxidation state. Solidification/stabilization (S/S) is a potential method for preventing Cr leaching from contaminated soil. We evaluated the leaching behavior of untreated and solidified/stabilized chromium contaminated soil samples obtained from two locations al a military facility in Louisiana. The leaching of chromium, as measured by the Toxicity Characteristic Leaching Procedure (TCLP), was expected to be dependent upon the chromium oxidation state. The pH, cation exchange capacity and particle size distribution were obtained for each sample and portions of each sample were solidified with Type I Portland cement. The oxidation state of chromium was determined by X-ray absorption spectroscopy (XAS). The sample from Site 1 contained 478 mg kg(-1) total chromium while the sample from Site 2 contained 1272 mg kg(-1) total Cr. The TCLP chromium concentration for Site 1 untreated soil was 3.4 mg L-1 and 2.0 mg L-1 for the S/S treated sample. The sample from Site 2 had TCLP chromium concentrations below the analytical detection limit (<1.0 mg L-1) for both untreated and S/S samples. The XAS data showed the presence of the more mobile and soluble Cr+6 at Site 1 but not at Site 2, The use of Portland cement alone was not effective in reducing the Cr+6 to the less soluble and less mobile Cr+3, or in physically preventing leaching of Cr+6. (C) 1997 Elsevier Science B.V. C1 PURDUE UNIV, DEPT AGRON, W LAFAYETTE, IN 47907 USA. UNIV CHICAGO, CONSORTIUM ADV RADIAT SOURCES, BROOKHAVEN NATL LAB, UPTON, NY 11973 USA. PURDUE UNIV, SCH CIVIL ENGN, W LAFAYETTE, IN 47907 USA. RP Rinehart, TL (reprint author), USA, CORPS ENGINEERS, WATERWAYS EXPT STN, CEWES EE R, 3909 HALLS FERRY RD, VICKSBURG, MS 39180 USA. RI Bajt, Sasa/G-2228-2010 NR 16 TC 24 Z9 27 U1 5 U2 17 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0304-3894 J9 J HAZARD MATER JI J. Hazard. Mater. PD APR PY 1997 VL 52 IS 2-3 BP 213 EP 221 DI 10.1016/S0304-3894(96)01808-0 PG 9 WC Engineering, Environmental; Engineering, Civil; Environmental Sciences SC Engineering; Environmental Sciences & Ecology GA XF549 UT WOS:A1997XF54900005 ER PT J AU McHenry, HM AF McHenry, HM TI Australopithecus africanus: Out of step in the human parade? SO JOURNAL OF HUMAN EVOLUTION LA English DT Meeting Abstract C1 LAWRENCE LIVERMORE NATL LAB,DEPT ANTHROPOL,DAVIS,CA 95616. NR 0 TC 0 Z9 0 U1 0 U2 0 PU ACADEMIC PRESS LTD PI LONDON PA 24-28 OVAL RD, LONDON, ENGLAND NW1 7DX SN 0047-2484 J9 J HUM EVOL JI J. Hum. Evol. PD APR PY 1997 VL 32 IS 4 BP A12 EP A13 PG 2 WC Anthropology; Evolutionary Biology SC Anthropology; Evolutionary Biology GA WN203 UT WOS:A1997WN20300024 ER PT J AU Turick, CE Apel, WA AF Turick, CE Apel, WA TI A bioprocessing strategy that allows for the selection of Cr(VI)-reducing bacteria from soils SO JOURNAL OF INDUSTRIAL MICROBIOLOGY & BIOTECHNOLOGY LA English DT Article DE Cr(VI)-reducing bacteria; bioprocess; anaerobic; soil; selection strategy ID HEXAVALENT CHROMIUM; REDUCTION; CHROMATE; STRAIN; LB300 AB Anaerobic bacteria that reduce hexavalent chromium [Cr(VI)] to trivalent [Cr(III)] are common in soils and were used to develop a bioprocess employing a selection strategy. Indigenous Cr(VI)-reducers were enriched from Cr(VI)-contaminated soil under anaerobic conditions. The mixed culture was then tested for Cr(VI)-reducing activity in a chemostat, followed by transfer to a l-L packed-bed bioreactor operated at 30 degrees C for additional study. The support material used in the reactor consisted of 6-mm porcelain saddles. Cr(VI) concentrations in the liquid ranged from 140-750 mg L-1. Cr(VI)-reducing bacteria were the dominant population with Cr(VI)-reduction rates of approximately 0.71 mg g(-1) dry cells h(-1) achieved at Cr(VI) concentrations of 750 mg L-1. These results indicate a potential for selecting and maintaining indigenous Cr(VI)-reducers in a bioreactor for Cr(VI)-remediation of groundwater or soil wash effluents. RP Turick, CE (reprint author), IDAHO NATL ENGN LAB,POB 1625,IDAHO FALLS,ID 83415, USA. NR 20 TC 15 Z9 15 U1 0 U2 1 PU STOCKTON PRESS PI BASINGSTOKE PA HOUNDMILLS, BASINGSTOKE, HAMPSHIRE, ENGLAND RG21 6XS SN 0169-4146 J9 J IND MICROBIOL BIOT JI J. Ind. Microbiol. Biotechnol. PD APR PY 1997 VL 18 IS 4 BP 247 EP 250 DI 10.1038/sj.jim.2900373 PG 4 WC Biotechnology & Applied Microbiology SC Biotechnology & Applied Microbiology GA WZ166 UT WOS:A1997WZ16600006 ER PT J AU Jarnik, M Simon, MN Steven, AC AF Jarnik, M Simon, MN Steven, AC TI Cornified cell envelope assembly: A new model based on EM measurements of thickness and projected density. SO JOURNAL OF INVESTIGATIVE DERMATOLOGY LA English DT Meeting Abstract C1 NIAMS,LSBR,NIH,BETHESDA,MD 20892. BROOKHAVEN NATL LAB,UPTON,NY 11973. NR 2 TC 0 Z9 0 U1 0 U2 0 PU BLACKWELL SCIENCE INC PI MALDEN PA 350 MAIN ST, MALDEN, MA 02148 SN 0022-202X J9 J INVEST DERMATOL JI J. Invest. Dermatol. PD APR PY 1997 VL 108 IS 4 BP 394 EP 394 PG 1 WC Dermatology SC Dermatology GA WP040 UT WOS:A1997WP04000418 ER PT J AU Ding, YS Sugano, Y Koomen, J Aggarwal, D AF Ding, YS Sugano, Y Koomen, J Aggarwal, D TI Synthesis of [F-18]RO41-0960, a potent catechol-O-methyltransferase inhibitor, for PET studies SO JOURNAL OF LABELLED COMPOUNDS & RADIOPHARMACEUTICALS LA English DT Article DE catechol-O-methyltransferase (COMT); Ro41-0960; COMT inhibitor; PET; [F-18]fluoromethane ID NUCLEOPHILIC AROMATIC-SUBSTITUTION AB Ro41-0960 (3,4-dihydroxy-5-nitro-2'-fluorobenzophene) is a potent, fluorine containing COMT inhibitor. In order to map catechol-O-methyltransferase (COMT) in vivo with PET, no-carrier-added [F-18]Ro41-0960 was synthesized by the nucleophilic aromatic substitution of [F-18]fluoride for 2'-nitro on 3,4-dimeihoxy-5,2'-dinitrobenzophenone, followed by hydrolysis with HBr. During the course of this study it was found that [F-18]fluoromethane ([F-18]CH3F) was generated as the side product of nucleophilic aromatic substitution reaction. Various precursors with different hydroxyl protecting groups were then investigated for the effects on this side reaction. RP Ding, YS (reprint author), BROOKHAVEN NATL LAB,DEPT CHEM,UPTON,NY 11973, USA. NR 10 TC 7 Z9 7 U1 0 U2 1 PU JOHN WILEY & SONS LTD PI W SUSSEX PA BAFFINS LANE CHICHESTER, W SUSSEX, ENGLAND PO19 1UD SN 0362-4803 J9 J LABELLED COMPD RAD JI J. Label. Compd. Radiopharm. PD APR PY 1997 VL 39 IS 4 BP 303 EP 318 DI 10.1002/(SICI)1099-1344(199704)39:4<303::AID-JLCR977>3.0.CO;2-W PG 16 WC Biochemical Research Methods; Chemistry, Medicinal; Chemistry, Analytical SC Biochemistry & Molecular Biology; Pharmacology & Pharmacy; Chemistry GA WT345 UT WOS:A1997WT34500006 ER PT J AU vanAntwerpen, R Chen, GC Pullinger, CR Kane, JP LaBelle, M Krauss, RM LunaChavez, C Forte, TM Gilkey, JC AF vanAntwerpen, R Chen, GC Pullinger, CR Kane, JP LaBelle, M Krauss, RM LunaChavez, C Forte, TM Gilkey, JC TI Cryo-electron microscopy of low density lipoprotein and reconstituted discoidal high density lipoprotein: Imaging of the apolipoprotein moiety SO JOURNAL OF LIPID RESEARCH LA English DT Article DE transmission electron microscopy; cold stage; LDL; HDL; lipoprotein structure ID CRYOELECTRON MICROSCOPY; TRIGLYCERIDE-RICH; A-I; IMMUNOELECTRON MICROSCOPY; RECEPTOR-BINDING; ESCHERICHIA-COLI; COMPLEXES; MEMBRANE; PHOSPHATIDYLCHOLINE; CONFORMATION AB Cryo-electron microscopy was used to analyze the structure of low density lipoprotein from normolipidemic subjects (N-LDL), phospholipid-depleted N-LDL (PD-LDL), small dense LDL from hypertriglyceridemic subjects (SD-LDL), and reconstituted discoidal high density lipoproteins (rHDL). In different projections of N-LDL, a high density component of the particle was visible as two parallel bands or as a single ring. Projections of PD-LDL were very similar to those of N-LDL, indicating that the contribution of phospholipid headgroups to the observed high density structure is minor. In preparations of SD-LDL, projections with two high density bands or a single high density ring were rare. Instead, triangular and diamond-shaped projections were recognized. In different projections of discoidal rHDL, a high density component was visible as a single band or as a single ring. The present results indicate that cryo-electron microscopy reveals the distribution of apolipoproteins within lipoprotein particles. Thus, apolipoprotein B-100 (apoB) in N-LDL appears to be organized as a double ring around the particle, while apoB in SD-LDL is indicated to have a different conformation. Cryo-electron micrographs of rHDL are consistent with the presence of apolipoprotein AI on the periphery of the lipoprotein disc. C1 UNIV ARIZONA,DEPT PHARMACOL,TUCSON,AZ 85721. UNIV CALIF SAN FRANCISCO,DEPT MED,INST CARDIOVASC RES,SAN FRANCISCO,CA 94143. UNIV CALIF BERKELEY,ERNEST ORLANDO LAWRENCE BERKELEY NATL LAB,BERKELEY,CA 94720. RP vanAntwerpen, R (reprint author), UNIV ARIZONA,DEPT BIOCHEM,TUCSON,AZ 85721, USA. FU NHLBI NIH HHS [HL 14237, HL 18574]; NIGMS NIH HHS [GM50551] NR 39 TC 44 Z9 44 U1 0 U2 3 PU LIPID RESEARCH INC PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814-3998 SN 0022-2275 J9 J LIPID RES JI J. Lipid Res. PD APR PY 1997 VL 38 IS 4 BP 659 EP 669 PG 11 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA WX103 UT WOS:A1997WX10300004 PM 9144081 ER PT J AU LaBelle, M Blanche, PJ Krauss, RM AF LaBelle, M Blanche, PJ Krauss, RM TI Charge properties of low density lipoprotein subclasses SO JOURNAL OF LIPID RESEARCH LA English DT Article DE agarose gel electrophoresis; LDL; charge; apoB; LDL subclass ID AGAROSE-GEL ELECTROPHORESIS; HUMAN-PLASMA; APOLIPOPROTEIN-B; SCAVENGER RECEPTOR; TRANSFER PROTEIN; SUBFRACTIONS; LDL; EXPRESSION; OXIDATION; PATTERNS AB Measurement of electrophoretic mobility and particle size of low density lipoproteins (LDL) allowed use of standard electrokinetic theory to quantitate LDL charge characteristics from subjects with predominance of large LDL (pattern A, n = 9) or small LDL (pattern B, n = 8). Pattern A LDL was found to have significantly lower (P less than or equal to 0.001) mobility (-0.22 +/- 0.01 mu m s(-1) cm V-1), surface potential (-4.2 +/- 0.3 mV) and charge density (-500 +/- 34 esu/cm(2)) than pattern B LDL (-0.25 +/- 0.01 mu m s(-1) cm V-1, -4.9 +/- 0.3 mV, and -580 +/- 30 esu/cm(2)), but no significant difference in particle valence (-22.0 +/- 1.4 for pattern A vs. -21.8 +/- 1.9 for pattern B). Thus, the greater mobility of pattern B LDL is due to similar net charge residing on a smaller particle. Comparison of subfractions in pattern B relative to pattern A LDL revealed greater surface potential in all pattern B subfractions and greater charge density in fractions of d greater than or equal to 1.032 g/ml. In a subset of subjects incubation with neuraminidase produced significant reductions in all LDL charge parameters for all subfractions, but did not abolish the differences between pattern A and B. Thus increased surface potential and charge density of unfractionated pattern B LDL is due both to charge proper ties of particles across the size and density spectrum as well as enrichment of pattern B LDL with smaller, denser particles that have higher surface charge density. RP LaBelle, M (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV LIFE SCI,DEPT MOL & NUCL MED,BERKELEY,CA 94720, USA. FU NHLBI NIH HHS [HL 18574] NR 42 TC 30 Z9 30 U1 0 U2 0 PU LIPID RESEARCH INC PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814-3998 SN 0022-2275 J9 J LIPID RES JI J. Lipid Res. PD APR PY 1997 VL 38 IS 4 BP 690 EP 700 PG 11 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA WX103 UT WOS:A1997WX10300007 PM 9144084 ER PT J AU Wang, SH DePaul, SM Bull, LM AF Wang, SH DePaul, SM Bull, LM TI High-resolution heteronuclear correlation between quadrupolar and spin-1/2 nuclei using multiple-quantum magic-angle spinning SO JOURNAL OF MAGNETIC RESONANCE LA English DT Article ID CROSS-POLARIZATION NMR; MAGNETIC-RESONANCE; MAS-NMR; SPECTROSCOPY; SOLIDS; SPINS C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV MAT SCI,BERKELEY,CA 94720. UNIV CALIF BERKELEY,DEPT CHEM,BERKELEY,CA 94720. UNIV CALIF SANTA BARBARA,MAT RES LAB,SANTA BARBARA,CA 93106. NR 34 TC 63 Z9 63 U1 1 U2 7 PU ACADEMIC PRESS INC JNL-COMP SUBSCRIPTIONS PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 SN 1090-7807 J9 J MAGN RESON JI J. Magn. Reson. PD APR PY 1997 VL 125 IS 2 BP 364 EP 368 DI 10.1006/jmre.1997.1137 PG 5 WC Biochemical Research Methods; Physics, Atomic, Molecular & Chemical; Spectroscopy SC Biochemistry & Molecular Biology; Physics; Spectroscopy GA WX556 UT WOS:A1997WX55600015 ER PT J AU Mitra, A Jiles, DC AF Mitra, A Jiles, DC TI Magnetic Barkhausen emissions in as-quenched Fe-Si-B amorphous alloy SO JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS LA English DT Article DE Barkhausen effect; amorphous metals; magnetostriction ID FERROMAGNETIC MATERIALS AB The dependence of magnetic Barkhausen emissions on magnetic field, frequency and applied tensile stress in positive magnetostrictive amorphous Fe82Si8B10 ribbon has been studied. The Barkhausen voltages (rms and peak-to-peak) and the number of events increased with increasing field amplitude and reached a constant saturation value at higher field amplitudes. This saturation voltage was a linearly increasing function of applied tensile stress over the range of stress studied. The Barkhausen voltage and number of events were also dependent on the frequency of the applied magnetic field. In these cases the number of Barkhausen events decreased with frequency, but the rms Barkhausen voltage increased linearly with frequency. A model theory has been developed assuming Barkhausen emissions originated from stochastic motion of domain walls, and it is shown that the instantaneous Barkhausen voltage is proportional to the number of Barkhausen events, the average size of the discontinuous change of magnetization, the rate of change of applied magnetic field and the irreversible differential susceptibility. The effect of stress on the Barkhausen parameters is explained assuming as-quenched amorphous alloy consists broadly of transverse and longitudinal domain orientations. An expression for the irreversible susceptibility, which is a function of stress, is presented. C1 IOWA STATE UNIV SCI & TECHNOL,AMES LAB,AMES,IA 50011. NATL MET LAB,MAGNET GRP,JAMSHEDPUR 831007,BIHAR,INDIA. RI Jiles, David/H-9548-2012; Sahu, Anjani/E-7590-2015 NR 13 TC 10 Z9 10 U1 0 U2 1 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 1997 VL 168 IS 1-2 BP 169 EP 176 DI 10.1016/S0304-8853(96)00699-3 PG 8 WC Materials Science, Multidisciplinary; Physics, Condensed Matter SC Materials Science; Physics GA XC999 UT WOS:A1997XC99900021 ER PT J AU Liu, CL Muddiman, DC Tang, KQ Smith, RD AF Liu, CL Muddiman, DC Tang, KQ Smith, RD TI Improving the microdialysis procedure for electrospray ionization mass spectrometry of biological samples SO JOURNAL OF MASS SPECTROMETRY LA English DT Article DE microdialysis; desalting; electrospray ionization mass spectrometry; DNA ID DNA; PROTEINS; OLIGODEOXYNUCLEOTIDES; OLIGONUCLEOTIDES; MOLECULES AB Significant advances in the area of microdialysis which allowed more effective handling of small volumes (microliters) of samples, more efficient desalting and enhanced mass spectrometric detection sensitivity are described. The previously reported on-line coupling of microdialysis with electrospray ionization (ESI) mass spectrometry has been found to be highly effective; however, direct coupling requires relatively high sample flow rates (similar to 2 mu l min(-1)) to obtain a stable ESI current compared with the bow rates of newer ESI sources (e.g, 'microspray'; 10-100 nl min(-1)). To circumvent this major limitation imposed by the dimensions of currently available materials, the microdialysis procedure was modified to an off-line mode in order to avoid excessive sample consumption. A more than tenfold decrease in sample consumption was achieved using the off-line mode vs the on-line mode, which resulted in a similar quality spectrum. In addition, several other aspects of the microdialysis approach were altered to improve its performance further: (i) an increase in dialysis temperature was found to increase the desalting efficiency greatly and therefore improve the spectrum quality; (ii) the addition of piperidine and imidazole to the dialysis buffer solution resulted in a reduction of charge states and a further increase in detection sensitivity for DNA and (iii) use of low concentrations (0-25 mM NH4OAc) of dialysis buffer shifted the DNA negative ions to higher charge states and produced a nearly tenfold increase in detection sensitivity and a slightly decreased desalting efficiency, Protocols for desalting different samples using microdialysis are discussed. (C) 1997 by John Wiley & Sons, Ltd. C1 PACIFIC NW LAB, ENVIRONM MOL SCI LAB, RICHLAND, WA 99352 USA. RI Smith, Richard/J-3664-2012 OI Smith, Richard/0000-0002-2381-2349 NR 28 TC 47 Z9 47 U1 1 U2 6 PU JOHN WILEY & SONS LTD PI W SUSSEX PA BAFFINS LANE CHICHESTER, W SUSSEX, ENGLAND PO19 1UD SN 1076-5174 J9 J MASS SPECTROM JI J. Mass Spectrom. PD APR PY 1997 VL 32 IS 4 BP 425 EP 431 DI 10.1002/(SICI)1096-9888(199704)32:4<425::AID-JMS493>3.0.CO;2-E PG 7 WC Biophysics; Chemistry, Organic; Spectroscopy SC Biophysics; Chemistry; Spectroscopy GA WV861 UT WOS:A1997WV86100010 ER PT J AU Thurston, TR Haldar, P Wang, YL Suenaga, M Jisrawi, NM Wildgruber, U AF Thurston, TR Haldar, P Wang, YL Suenaga, M Jisrawi, NM Wildgruber, U TI In situ measurements of texture and phase development in (Bi,Pb)(2)Sr2Ca2Cu3O10-Ag tapes SO JOURNAL OF MATERIALS RESEARCH LA English DT Article ID CRITICAL-CURRENT DENSITY; AG-SHEATHED TAPES; GROWTH; BI2SR2CA2CU3O10+DELTA; WIRES AB Hard x-rays from a synchrotron source were utilized in diffraction experiments performed at elevated temperatures (up to similar to 870 degrees C) on (Bi, Pb)(2)Sr2Ca2Cu3O10 (Bi-2223) tapes completely encased in silver. The general behavior of the phase and texture development under typical processing conditions was determined, and the effects that several variations in processing conditions had on the phase and texture development were examined. These results and their implications for improving processing conditions are discussed. C1 INTERMAGNET GEN CORP,LATHAM,NY 12110. BROOKHAVEN NATL LAB,DEPT APPL SCI,UPTON,NY 11973. BIRZEIT UNIV,DEPT PHYS,BIRZEIT,ISRAEL. RP Thurston, TR (reprint author), BROOKHAVEN NATL LAB,DEPT PHYS,UPTON,NY 11973, USA. NR 20 TC 16 Z9 16 U1 0 U2 1 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DR, WARRENDALE, PA 15086 SN 0884-2914 J9 J MATER RES JI J. Mater. Res. PD APR PY 1997 VL 12 IS 4 BP 891 EP 905 DI 10.1557/JMR.1997.0129 PG 15 WC Materials Science, Multidisciplinary SC Materials Science GA WR622 UT WOS:A1997WR62200004 ER PT J AU Rawers, JC Cook, D AF Rawers, JC Cook, D TI Similarities and differences in the microstructure of attritor-milled Fe-Al-N compositions SO JOURNAL OF MATERIALS RESEARCH LA English DT Article ID POWDERS AB Although numerous studies of high-energy, ball-milled metal powders have been conducted, to date few studies have: characterized the mechanical processing of identical elemental compositions of prealloyed powders and of powder blends. This study reports on the mechanical processing (attritor ball milling) in argon and nitrogen gas environments of (a) iron powder and prealloyed iron-2 wt. % aluminum powder, and (b) iron-aluminum, iron-aluminum nitride, and iron-iron nitride powder blends. When nitrogen was milled into iron particles either from nitride powder or by gas infusion, the nitrogen dissolved interstitially in bcc-Fe (principally at the grain boundaries) or was present as bct-Fe nanoparticles at the bcc-Fe nanograin boundaries. The resulting nitrogen distribution was independent of how the nitrogen was added. Milled blends of iron and aluminum powder and prealloyed iron-aluminum powder resulted in similar microstructures: micrometer size particles with similar nanograin size. The aluminum in the blended powder mixture developed an ultrafine distribution on the grain boundaries, but it did not become uniformly distributed within the bcc-fie grains. In contrast, the aluminum in prealloyed Fe-Al powder remained in solid solution during the mechanical milling. C1 OLD DOMINION UNIV, DEPT PHYS, NORFOLK, VA 23529 USA. RP Rawers, JC (reprint author), US DOE, ALBANY RES CTR, ALBANY, OR 97321 USA. NR 25 TC 0 Z9 1 U1 2 U2 2 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DR, WARRENDALE, PA 15086 SN 0884-2914 J9 J MATER RES JI J. Mater. Res. PD APR PY 1997 VL 12 IS 4 BP 947 EP 952 DI 10.1557/JMR.1997.0135 PG 6 WC Materials Science, Multidisciplinary SC Materials Science GA WR622 UT WOS:A1997WR62200010 ER PT J AU Taljat, B Zacharia, T Haggag, FM AF Taljat, B Zacharia, T Haggag, FM TI Analysis of hall-indentation load-depth data .1. Determining elastic modulus SO JOURNAL OF MATERIALS RESEARCH LA English DT Article AB Analysis of ball-indentation process was made by the finite element (FE) method. A series of indentation FE analyses were made on materials with different elastic modulus (E), and a simple relationship between E and the load-depth (F-h) unloading data is presented. In order to check for the influence of other material properties, thorough research has been performed, introducing a combination of response surface (RS) and FE analysis. As a result, a relationship between the indentation unloading slope, E, and the strain hardening exponent was derived. Also, the indenter compliance effect has been investigated. The indenter compliance correction was calculated and applied to the experimentally measured F-h results. Experimental testing was made on three materials with essentially different elastic moduli. Comparison of the results obtained by newly developed equations with the results from other well-known equations is also presented. RP Taljat, B (reprint author), OAK RIDGE NATL LAB,DIV MET & CERAM,POB 2008,OAK RIDGE,TN 37831, USA. NR 13 TC 6 Z9 7 U1 0 U2 5 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DR, WARRENDALE, PA 15086 SN 0884-2914 J9 J MATER RES JI J. Mater. Res. PD APR PY 1997 VL 12 IS 4 BP 965 EP 974 DI 10.1557/JMR.1997.0137 PG 10 WC Materials Science, Multidisciplinary SC Materials Science GA WR622 UT WOS:A1997WR62200012 ER PT J AU Wang, Q Gilmer, D Fan, Y Franciosi, A Evans, DF Gladfelter, WL Zhang, XF AF Wang, Q Gilmer, D Fan, Y Franciosi, A Evans, DF Gladfelter, WL Zhang, XF TI Microstructure of ruthenium dioxide films grown on alpha-Al2O3 (0001), alpha-Al2O3 (1(1)over-bar02), and SrTiO3 (100) using reactive sputtering SO JOURNAL OF MATERIALS RESEARCH LA English DT Article ID CHEMICAL-VAPOR-DEPOSITION; THIN-FILMS; ELECTRICAL TRANSPORT; DIFFUSION-BARRIERS; SAPPHIRE 0001; METAL-OXIDE; RUO2 FILMS; OXYGEN; METALLIZATION; ELECTRODES AB A quantitative study was made of the composition and microstructure of RuO2 films deposited on three different substrates using reactive sputtering. Most of the films had a composition within 2.5 wt. % of the correct stoichiometry; the only exceptions were films grown on Al2O3 (0001) at 150 degrees C, which had an oxygen-to-ruthenium ratio of 1:2.24. The excess oxygen was attributed to a thin oxygen-rich layer that encapsulated the grains. Hydrogen concentrations for the films deposited on Al2O3 (0001) were 14, 6, 6, and <0.5 at. % for room, 150, 300, and 450 degrees C growth temperatures respectively. The films deposited at room temperature were amorphous on Al2O3 (0001) and SrTiO3 (100), but weakly crystalline on Al2O3 (<1(1)over bar 02>). Highly oriented RuO2 (100) films were produced on Al2O3 (0001) at deposition temperatures greater than or equal to 150 degrees C. The in-plane alignment was [010](RuO2)//[<(2)over bar 110>](Al2O3) and a threefold mosaic microstructure was observed. The grain boundaries in these films were discontinuous until the substrate temperature was raised to 450 degrees C, where coherent grain boundaries were formed. The films grown on Al2O3 (<(1)over bar 102>) at 450 degrees C exhibited the epitaxial relationship: RuO2(101)//Al2O3 (<(1)over bar 102>). The in-plane alignment was RuO2[101]//Al2O3[<(1)over bar 101>], and the lattice parameters were the same as found in bulk RuO2. Transmission electron microscopy indicated a large degree of imperfection in the region between coalescing grains. The RuO2 films grown on SrTiO3 (100) at room temperature were amorphous. The film grown at 450 degrees C showed a preferential orientation with RuO2 (100)//SrTiO3 (100), but without in-plane orientation. C1 UNIV MINNESOTA,DEPT CHEM,MINNEAPOLIS,MN 55455. UNIV MINNESOTA,DEPT CHEM ENGN & MAT SCI,MINNEAPOLIS,MN 55455. ARGONNE NATL LAB,DIV MAT SCI,ARGONNE,IL 60439. NR 36 TC 14 Z9 14 U1 2 U2 6 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DR, WARRENDALE, PA 15086 SN 0884-2914 J9 J MATER RES JI J. Mater. Res. PD APR PY 1997 VL 12 IS 4 BP 984 EP 996 DI 10.1557/JMR.1997.0139 PG 13 WC Materials Science, Multidisciplinary SC Materials Science GA WR622 UT WOS:A1997WR62200014 ER PT J AU Shoup, SS Paranthaman, M Beach, DB Specht, ED Williams, RK AF Shoup, SS Paranthaman, M Beach, DB Specht, ED Williams, RK TI Sol-gel synthesis of LaAlO3; Epitaxial growth of LaAlO3 thin films on SrTiO3 (100) SO JOURNAL OF MATERIALS RESEARCH LA English DT Article ID SUPERCONDUCTING FILMS; PRECURSORS; YBA2CU3O7-X; DEPENDENCE; BICRYSTALS; CERAMICS; MOCVD AB A LaAlO3 precursor solution was prepared via an all alkoxide sol-gel route, The solution of lanthanum methoxyethoxide and aluminum methoxyethoxide in 2-methoxyethanol was prepared via ligand exchange starting from lanthanum isopropoxide and aluminum sec-butoxide and was used to make both LaAlO3 powders and films. Complete hydrolysis of the solution formed a gel that yielded well-crystallized LaAlO3 powders when fired in air at 800 degrees C. A partially hydrolyzed solution was spun-cast on SrTiO3 (100) single crystal substrates. Epitaxial films of LaAlO3 were subsequently formed during pyrolysis in O-2 at 800 degrees C in a rapid thermal annealing furnace for a total of 8 min. The films were strongly c-axis oriented, verified by x-ray rocking curve results from the (003) plane with full-width at half-maximum (FWHM) = 0.87 degrees, and had good in-plane texture shown by a phi scan of the (202) plane with FWHM = 1.07 degrees. C1 OAK RIDGE NATL LAB,DIV MET & CERAM,OAK RIDGE,TN 37831. RP Shoup, SS (reprint author), OAK RIDGE NATL LAB,DIV CHEM SCI,OAK RIDGE,TN 37831, USA. RI Specht, Eliot/A-5654-2009; Paranthaman, Mariappan/N-3866-2015 OI Specht, Eliot/0000-0002-3191-2163; Paranthaman, Mariappan/0000-0003-3009-8531 NR 20 TC 32 Z9 35 U1 0 U2 5 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DR, WARRENDALE, PA 15086 SN 0884-2914 J9 J MATER RES JI J. Mater. Res. PD APR PY 1997 VL 12 IS 4 BP 1017 EP 1021 DI 10.1557/JMR.1997.0142 PG 5 WC Materials Science, Multidisciplinary SC Materials Science GA WR622 UT WOS:A1997WR62200017 ER PT J AU Boyle, TJ Dimos, D Schwartz, RW Alam, TM Sinclair, MB Buchheit, CD AF Boyle, TJ Dimos, D Schwartz, RW Alam, TM Sinclair, MB Buchheit, CD TI Aging characteristics of a hybrid sol-gel Pb(Zr,Ti)O-3 precursor solution SO JOURNAL OF MATERIALS RESEARCH LA English DT Article ID THIN-FILMS AB The ''aging'' characteristics of an acetic acid/methanol solvent-based lead zirconate titanate (PZT) precursor solution, prepared by the Inverted Mixing Order (IMO) process, have been studied for an extended period of time. The changes in film properties were characterized using optical microscopy, optical scattering, and ferroelectric testing. Films generated from the IMO process exhibit an increase in thickness as a function of solution age due to chemical ''aging'' (esterification) of the precursor solution. This increased thickness results in a decrease in the microstructural uniformity, which affects the electrical and optical properties. In order to understand and eventually control this phenomenon, we have quantified the ''aging'' of this solution using a variety of analytical methods, including H-1 NMR spectroscopy, pH measurements, and Fourier transform infrared (FTIR) spectroscopy. It is of note that we have discovered a method that circumvents this ''aging'' problem by removal of the volatile material, forming an IMO powder which can be redissolved to produce high quality PZT thin films whenever desired. C1 SANDIA NATL LABS,ALBUQUERQUE,NM 87715. RP Boyle, TJ (reprint author), SANDIA NATL LABS,ADV MAT LAB,1001 UNIV BLVD SE,ALBUQUERQUE,NM 87106, USA. NR 23 TC 33 Z9 33 U1 0 U2 9 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DR, WARRENDALE, PA 15086 SN 0884-2914 J9 J MATER RES JI J. Mater. Res. PD APR PY 1997 VL 12 IS 4 BP 1022 EP 1030 DI 10.1557/JMR.1997.0143 PG 9 WC Materials Science, Multidisciplinary SC Materials Science GA WR622 UT WOS:A1997WR62200018 ER PT J AU Miller, MK AF Miller, MK TI Three-dimensional atom probes SO JOURNAL OF MICROSCOPY-OXFORD LA English DT Review ID FIELD-ION MICROSCOPY; EVAPORATION; DESIGNS; SYSTEM AB A three-dimensional atom probe permits the elemental reconstruction of a small volume of a specimen by determining the x, y and z positions and mass-to-charge ratio of the atoms in that volume. The historical development of this new type of atom probe is described. Several variants of these instruments including the position-sensitive atom probe, the optical atom probe and the tomographic atom probe are reviewed. The various methods of data visualization and analysis are summarized. The performance of the three-dimensional atom probe is compared with the energy-compensated atom probe. RP Miller, MK (reprint author), OAK RIDGE NATL LAB,DIV MET & CERAM,MICROSCOPY & MICROANALYT SCI GRP,POB 2008,OAK RIDGE,TN 37831, USA. NR 47 TC 19 Z9 19 U1 0 U2 4 PU BLACKWELL SCIENCE LTD PI OXFORD PA P O BOX 88, OSNEY MEAD, OXFORD, OXON, ENGLAND OX2 0NE SN 0022-2720 J9 J MICROSC-OXFORD JI J. Microsc.-Oxf. PD APR PY 1997 VL 186 BP 1 EP 16 DI 10.1046/j.1365-2818.1997.1910759.x PN 1 PG 16 WC Microscopy SC Microscopy GA WZ021 UT WOS:A1997WZ02100001 ER PT J AU Bell, GI Jurka, J AF Bell, GI Jurka, J TI The length distribution of perfect dimer repetitive DNA is consistent with its evolution by an unbiased single-step mutation process SO JOURNAL OF MOLECULAR EVOLUTION LA English DT Article DE repeats; repetitive DNA; microsatellites; evolution; dimers ID MICROSATELLITE LOCI; SEQUENCE EVOLUTION; MAMMALIAN GENOMES; REPEATS; GENE; RECOMBINATION; CHROMOSOME; RATES; ROLES; MODEL AB We have examined the length distribution of perfect dimer repeats, where perfect means uninterrupted by any other base, using data from GenBank on primates and rodents, Virtually no lengths greater than 30 repeats are found, except for rodent AG repeats, which extend to 35, Comparable numbers of long AC and AG repeats suggest that they have not been selected for special functions or DNA structures. We have compared the data with predictions of two models: (1) a Bemoulli Model in which bases are assumed equally likely and distributed at random and (2) an Unbiased Random Walk. Model (URWM) in which repeats are permitted to change length by plus or minus one unit, with equal probabilities, and in which base substitutions are allowed to destroy long perfect repeats, producing two shorter perfect repeats. The source of repeats is assumed to be from single base substitutions from neighboring sequences, i,e., those differing from the perfect repeat by a single base. Mutation rates either independent of repeal length or proportional to length were considered. An upper limit to the lengths L approximate to 30 is assumed and isolated dimers are assumed unable to expand, so that there are absorbing barriers to the random walk at lengths 1 and L + 1, and a steady state of lengths is reached. With these assumptions and estimated values for the rates of length mutation and base substitution, reasonable agreement is found with the data for lengths > 5 repeats. Shorter repeats, of lengths less than or equal to 3 are in general agreement with the Bemoulli Model. By reducing the rate of length mutations for n less than or equal to 5, it is possible to obtain reasonable agreement with the full range of data, For these reduced rates, the times between length mutations become comparable to those suggested for a bottleneck in the evolution of Homo sapiens, which may be the reason for low heterozygosity of short repeats. C1 GENET INFORMAT RES INST, PALO ALTO, CA 94306 USA. RP Bell, GI (reprint author), LOS ALAMOS NATL LAB, THEORET BIOL & BIOPHYS GRP, MS K710, LOS ALAMOS, NM 87545 USA. NR 33 TC 47 Z9 47 U1 0 U2 2 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 SN 0022-2844 J9 J MOL EVOL JI J. Mol. Evol. PD APR PY 1997 VL 44 IS 4 BP 414 EP 421 DI 10.1007/PL00006161 PG 8 WC Biochemistry & Molecular Biology; Evolutionary Biology; Genetics & Heredity SC Biochemistry & Molecular Biology; Evolutionary Biology; Genetics & Heredity GA WR618 UT WOS:A1997WR61800009 PM 9089081 ER PT J AU Prabakar, S Assink, RA AF Prabakar, S Assink, RA TI Hydrolysis and condensation kinetics of two component organically modified silica sols SO JOURNAL OF NON-CRYSTALLINE SOLIDS LA English DT Article ID FUNCTIONAL-GROUP KINETICS; SILOXANE-OXIDE MATERIALS; GEL KINETICS; NMR CHARACTERIZATION; SI-29; TETRAETHOXYSILANE AB A kinetic model for the hydrolysis and self- and cross-condensation reactions occurring in two component organically modified silica sols is presented. The hybrid sols were acid-catalyzed mixtures of tetraethoxysilane (TEOS) and organically modified triethoxysilanes (RTES, where R = CH3, C2H5 or C6H5) reacted with limited amounts of water. The product distributions as a function of reaction time were measured by high resolution Si-29 NMR spectroscopy and were simulated using numerical methods. The hydrolysis reactions were reversible whereas the condensation reactions were irreversible. The cross-condensation rates for each of the sols were intermediate to the condensation rates of the individual components. Calculations show that for these sols, the concentration of cross-condensed species is a weak function of relative rates of self-condensation. C1 ADV MAT LAB,ALBUQUERQUE,NM 87106. SANDIA NATL LABS,ALBUQUERQUE,NM 87185. NR 17 TC 39 Z9 43 U1 1 U2 6 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3093 J9 J NON-CRYST SOLIDS JI J. Non-Cryst. Solids PD APR PY 1997 VL 211 IS 1-2 BP 39 EP 48 DI 10.1016/S0022-3093(96)00634-5 PG 10 WC Materials Science, Ceramics; Materials Science, Multidisciplinary SC Materials Science GA WP410 UT WOS:A1997WP41000004 ER PT J AU Kim, KH Torgeson, DR Borsa, F Cho, JP Martin, SW Svare, I Majer, G AF Kim, KH Torgeson, DR Borsa, F Cho, JP Martin, SW Svare, I Majer, G TI Evidence of complex ionic motion in xLi(2)S+(1-x)B2S3 glassy fast ionic conductors from Li-7 and B-11 NMR and ionic conductivity measurements SO JOURNAL OF NON-CRYSTALLINE SOLIDS LA English DT Article ID NUCLEAR-SPIN RELAXATION; LITHIUM THIOBORATE GLASSES; ELECTRICAL-CONDUCTIVITY; DISORDERED SOLIDS; AC CONDUCTION; DIFFUSION; MODEL; DYNAMICS; ECHO AB Ion dynamics in the highly conductive glassy fast ionic conductor, 0.7Li(2)S + 0.3B(2)S(3), were studied with NMR line width and nuclear spin-lattice relaxation, R(1)(omega,T), of both mobile Li-7 and immobile B-11 nuclei, NMR pulsed field gradient diffusivity, and electrical (ionic) conductivity, sigma(omega,T) over wide ranges of temperature and frequency. Some measurements were also done in 0.65Li(2)S + 0.35B(2)S(3). The quadrupolar split NMR spectrum of the B-11 indicated that about 80% of the boron were in BS3 groups and 20% were in BS4 groups, and their relaxations could be resolved. We fitted R(1Li) with a double-peaked distribution, Z(Li), of activation energies, E(a) for the hops, where the peaks are due to the differing environments near BS3 and BS4. The conductivity, sigma(omega,T), was calculated quantitatively from Z(Li)(E(a)) in our model with random walk and percolation over the lowest barriers. The apparent correlation time tau(B)((3)) derived from spin-lattice relaxation of B-11 in trigonal BS3 groups, R(1B)(BS3), were much shorter than tau(B)((4)) from R(1B)(BS4), which again were shorter than tau(Li) from R(1Li), although all relaxations are due to fluctuating electric field gradients from the hopping Li+ ions. The times, tau(Li), are those of single ion hopping, while times tau(B) are due to the fluctuations of the electric field gradient at the BSx groups which was due to the combined effect of several Li+ ions hopping and to the interaction of the Li+ ion with the BSx groups where x = 3 or 4. The Li-7 NMR line narrowing and diffusivity yielded additional information on the correlation time for Li+ hopping motion which are consistent, within our model, with the sigma(omega,T) and R(1)(omega,T) data. C1 IOWA STATE UNIV SCI & TECHNOL,DEPT PHYS & ASTRON,AMES,IA 50011. IOWA STATE UNIV SCI & TECHNOL,AMES LAB,AMES,IA 50011. IOWA STATE UNIV SCI & TECHNOL,DEPT MAT SCI & ENGN,AMES,IA 50011. UNIV TRONDHEIM,NTH,DEPT PHYS,N-7034 TRONDHEIM,NORWAY. MAX PLANCK INST,INST PHYS,D-70569 STUTTGART,GERMANY. UNIV PAVIA,DIPARTIMENTO FIS A VOLTA,I-27100 PAVIA,ITALY. RI Cho, Jaephil/E-4265-2010 NR 47 TC 11 Z9 11 U1 0 U2 11 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3093 J9 J NON-CRYST SOLIDS JI J. Non-Cryst. Solids PD APR PY 1997 VL 211 IS 1-2 BP 112 EP 125 DI 10.1016/S0022-3093(96)00615-1 PG 14 WC Materials Science, Ceramics; Materials Science, Multidisciplinary SC Materials Science GA WP410 UT WOS:A1997WP41000013 ER PT J AU Gross, J Scherer, GW Alviso, CT Pekala, RW AF Gross, J Scherer, GW Alviso, CT Pekala, RW TI Elastic properties of crosslinked Resorcinol-Formaldehyde gels and aerogels SO JOURNAL OF NON-CRYSTALLINE SOLIDS LA English DT Article ID ORGANIC AEROGELS; VELOCITY AB Resorcinol-formaldehyde (RF) gels with different monomer concentrations were characterized before and after supercritical drying from carbon dioxide in order to determine the influence of the drying process on elastic moduli and structure. Wet gel shear modulus. Young's modulus and Poisson ratio were determined using the beam-bending method. In addition, acoustic shear waves were used to measure the shear modulus of wet gels. The two methods are shown to agree well. During supercritical extraction of the pore liquid the elastic moduli typically increase by a factor of 1.5 to 5 depending on density. Although in general the elastic moduli do not exhibit power-law dependence on density, in the limited density range covered by our experiments scaling exponents of 6.2 for the wet gels and 4.8 for the aerogels are derived. Aging in acetic acid is shown to have no significant impact on gel elastic properties. Wet and dry gels were analyzed for their structural efficiency and the fraction of elastically effective mass increases with density from 8 to 70%. C1 LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550. RP Gross, J (reprint author), PRINCETON UNIV,DEPT CIVIL ENGN & OPERAT RES,ENG QUAD E-319,PRINCETON,NJ 08544, USA. OI Scherer, George/0000-0002-5874-2627 NR 26 TC 33 Z9 33 U1 2 U2 13 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3093 J9 J NON-CRYST SOLIDS JI J. Non-Cryst. Solids PD APR PY 1997 VL 211 IS 1-2 BP 132 EP 142 DI 10.1016/S0022-3093(96)00621-7 PG 11 WC Materials Science, Ceramics; Materials Science, Multidisciplinary SC Materials Science GA WP410 UT WOS:A1997WP41000015 ER PT J AU Kawaguchi, MN Denn, MM AF Kawaguchi, MN Denn, MM TI Visualization of the flow of a thermotropic liquid crystalline polymer in a tube with a conical contraction SO JOURNAL OF NON-NEWTONIAN FLUID MECHANICS LA English DT Article DE contraction flow; flow visualization; liquid crystalline polymers ID POISEUILLE FLOW; RHEO-OPTICS; COPOLYESTERS; RHEOMETRY; TEXTURE; SHEAR AB Flow visualization experiments have been used to characterize the fluid dynamics of a thermotropic liquid crystalline polymer, Vectra A, in the barrel and conical entry of a capillary rheometer. The displacement profiles indicate shear-thinning in the straight section, with a power law index much lower than that measured rheometrically. The contraction flow is complex and three-dimensional. There are asymmetrical vortices and signs of macroscopic structural changes. For flow in a corner, the profiles display patterns that cannot be predicted by the shear-thinning effects alone. These characteristics are in striking contrast to the results on lyotropic solutions in thin slit geometries (see J.N. Baleo and P. Navard, J. Rheol., 38 (1994) 1641-1655, and B.D. Bedford and W.R. Burghardt, J. Rheol., 38 (1994) 1657-1679). (C) 1997 Elsevier Science B.V. C1 UNIV CALIF BERKELEY,DEPT CHEM ENGN,BERKELEY,CA 94720. RP Kawaguchi, MN (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV MAT SCI,BERKELEY,CA 94720, USA. NR 21 TC 7 Z9 8 U1 0 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0377-0257 J9 J NON-NEWTON FLUID JI J. Non-Newton. Fluid Mech. PD APR PY 1997 VL 69 IS 2-3 BP 207 EP 219 DI 10.1016/S0377-0257(96)01524-8 PG 13 WC Mechanics SC Mechanics GA XA707 UT WOS:A1997XA70700006 ER PT J AU Baumert, BM Liepmann, D Muller, SJ AF Baumert, BM Liepmann, D Muller, SJ TI Digital particle image velocimetry in flows with nearly closed pathlines: The viscoelastic Taylor-Couette instability SO JOURNAL OF NON-NEWTONIAN FLUID MECHANICS LA English DT Article DE viscoelastic instability; secondary flow visualization; Taylor-Couette; Boger fluids ID LIGHT-SHEET AB We describe a novel technique for applying digital particle image velocimetry (DPIV) in steady or slowly varying flows with nearly closed pathlines in which the flow of interest is small relative to the primary flow and the primary flow is normal to the plane of illumination. Despite the fact that in-plane particle displacements are negligible during video-rate image capture, DPIV can be used by implementing extremely low levels of seeding and using long 'exposure' times. An 'exposure' for subsequent DPIV processing corresponds to the image formed by taking the minimum of each pixel position from each of the frames captured during the exposure time. Here, we have used a grey scale in which a pixel value of zero corresponds to white so a bright particle that appears in any of the frames captured during the exposure time will appear in the composite exposure. Preliminary results for a viscoelastic fluid in Taylor-Couette flow (flow between concentric rotating cylinders) are shown. As long as the cylinders are adequately aligned, there is no difficulty in resolving the main features of the secondary flow. Secondary flows four to six orders of magnitude weaker than the base flow can be resolved by this method in the present experiment. This technique would be equally successful in other flows such as flow between rotating parallel disks or between a cone and plate, both of which are important for rheological characterization of fluids. Through the use of co-rotation of fixtures, this technique could also be extended to higher temporal resolution and higher secondary velocities relative to the base flow. (C) 1997 Elsevier Science B.V. C1 UNIV CALIF BERKELEY,DEPT CHEM ENGN,BERKELEY,CA 94720. UNIV CALIF BERKELEY,DEPT MECH ENGN,BERKELEY,CA 94720. UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,CTR ADV MAT,BERKELEY,CA 94720. NR 17 TC 12 Z9 13 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0377-0257 J9 J NON-NEWTON FLUID JI J. Non-Newton. Fluid Mech. PD APR PY 1997 VL 69 IS 2-3 BP 221 EP 237 DI 10.1016/S0377-0257(96)01538-8 PG 17 WC Mechanics SC Mechanics GA XA707 UT WOS:A1997XA70700007 ER PT J AU Iwase, A Rehn, LE Baldo, PM Funk, L AF Iwase, A Rehn, LE Baldo, PM Funk, L TI Reduction of freely migrating defect concentrations by cascade remnants in Ni-Si alloys SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article ID RADIATION-INDUCED SEGREGATION; KINETICS AB Interactions of cascade remnants with freely migrating defects in Ni-12.7% Si were investigated using in-situ Rutherford backscattering spectrometry during simultaneous irradiation with 1.5 MeV He and 400 keV Ne ions at elevated temperatures. Radiation induced segregation of Si atoms toward the specimen surface caused gamma'-Ni3Si layers to grow on the surface during irradiation. The gamma'-Ni3Si growth rate during He bombardment was strongly suppressed by simultaneous irradiation with Ne ions, even when the calculated defect production rate for the Ne ions was only a few percent of that for the He ions. This result shows that the cascade remnants generated by the Ne ions act as additional recombination sites for freely migrating defects, reducing their steady state concentration. Despite a large difference in defect properties and in the kinetics of radiation induced segregation between the two alloys, the effects of cascade remnants on freely migrating defects in Ni-12.7% Si are remarkably similar to those found previously in Cu-1% Au. C1 JAPAN ATOM ENERGY RES INST,ADV SCI RES CTR,NAKA,IBARAKI 31911,JAPAN. RP Iwase, A (reprint author), ARGONNE NATL LAB,DIV MAT SCI,9700 S CASS AVE,ARGONNE,IL 60439, USA. NR 12 TC 4 Z9 4 U1 0 U2 1 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 1997 VL 244 IS 2 BP 147 EP 152 DI 10.1016/S0022-3115(96)00734-9 PG 6 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA XB870 UT WOS:A1997XB87000005 ER PT J AU Wechsler, MS Lin, C Sommer, WF Daemen, LL Ferguson, PD AF Wechsler, MS Lin, C Sommer, WF Daemen, LL Ferguson, PD TI Radiation effects in materials for accelerator-driven neutron technologies SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT Symposium on Radiation Materials Science in Technology Applications / Annual TMS Meeting CY FEB 04-08, 1996 CL ANAHEIM, CA SP Minerals Met & Mat Soc ID SPALLATION; TRANSMUTATION; DAMAGE; DESIGN AB Accelerator-driven neutron technologies include facilities for neutron scattering research, accelerator transmutation of waste (ATW), and accelerator production of tritium. These systems use spallation neutron sources (SNS's) in which high-energy protons (E=1000-2000 MeV) strike a heavy-metal target, producing spallation neutrons with energies extending up to the incident proton energy. The nature of the spallation process and the codes used to calculate spallation radiation damage are reviewed. Calculations of displacement and helium production in a major target material, tungsten, are described. Displacement cross sections reach about 9000 b for 1600 MeV neutrons or protons. In a simulated high-current-density ATW SNS, displacement production rates are about 0.1 and 1 dpa/d due to the spallation neutrons and incident 1600 MeV protons, respectively, and the He production rates are about 1 and 250 appm He/d, respectively. These damage rates probably represent an upper limit to what can be tolerated. More realistic solid-target SNS's will operate at lower current densities, and the damage rates are likely to be reduced by a factor of 3 or 4 from the values cited above. In any case, however, radiation damage to target and container materials is a major consideration in the design of SNS's. C1 N CAROLINA STATE UNIV,RALEIGH,NC 27695. LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545. RI Lujan Center, LANL/G-4896-2012; OI Ferguson, Phillip/0000-0002-7661-4223 NR 34 TC 5 Z9 5 U1 1 U2 7 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 1997 VL 244 IS 3 BP 177 EP 184 DI 10.1016/S0022-3115(96)00735-0 PG 8 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA XB871 UT WOS:A1997XB87100002 ER PT J AU Stoller, RE AF Stoller, RE TI Non-steady-state conditions and incascade clustering in radiation damage modeling SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT Symposium on Radiation Materials Science in Technology Applications / Annual TMS Meeting CY FEB 04-08, 1996 CL ANAHEIM, CA SP Minerals Met & Mat Soc ID MOLECULAR-DYNAMICS; DISPLACEMENT CASCADES; DEFECT ACCUMULATION; STAINLESS-STEEL; PRODUCTION BIAS; IRRADIATION; COPPER; METALS; SIMULATION; RATES AB The results of molecular dynamics simulations of displacement cascades indicate that a large fraction of the point defects that survive after intracascade annealing may be found in clusters, rather than as individual point defects. In addition, the mobility of these small point defect clusters may be relatively high. The impact of these clusters is discussed in the framework of a radiation damage model for austenitic stainless steel using the chemical reaction rate theory. Although this theory has been broadly applied in models simulating such radiation-induced phenomena as void swelling, irradiation creep, and embrittlement, such models have generally not fully accounted for incascade clustering. Many of these models have also focused on the assumed steady state behavior and tended to neglect the explicit dose and temperature dependence of the sink structure. A previously-developed model has been modified to permit a more extensive investigation of the time (dose) dependence of the point defect and extended defect concentrations and of the impact of incascade clustering. A preliminary evaluation of the so-called production bias was also carried out with this model. The results indicate that defect behavior is complex and that the limiting behavior predicted by simple analytical solutions is frequently not achieved. The comparison of the production bias and the conventional dislocation/interstitial bias found that two were comparable if examined separately at 500 degrees C, but that the production bias effect was minimized in the presence of a reasonable dislocation/interstitial bias. RP Stoller, RE (reprint author), OAK RIDGE NATL LAB, DIV MET & CERAM, POB 2008, OAK RIDGE, TN 37831 USA. RI Stoller, Roger/H-4454-2011 NR 39 TC 7 Z9 7 U1 1 U2 9 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 1997 VL 244 IS 3 BP 195 EP 204 DI 10.1016/S0022-3115(96)00737-4 PG 10 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA XB871 UT WOS:A1997XB87100004 ER PT J AU Weber, WJ Williford, RE Sickafus, KE AF Weber, WJ Williford, RE Sickafus, KE TI Total displacement functions for SiC SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT Symposium on Radiation Materials Science in Technology Applications / Annual TMS Meeting CY FEB 04-08, 1996 CL ANAHEIM, CA SP Minerals Met & Mat Soc ID POLYATOMIC MATERIALS; IONS AB Numerical solutions for the displacement functions in SIC are determined from the coupled integro-differential equations governing the total number of type-j atoms displaced in the collision cascade initiated by a primary knock-on atom (PKA) of type-i and energy E. Atomic scattering cross sections based on either the inverse power law screening potentials or the Ziegler, Biersack, and Littmark (ZBL) universal screening potential are used in the calculation of the displacement functions. The electronic stopping powers used in the calculations are either derived from the LSS and Bethe-Bloch theories or generated from the SRIM-96 electronic stopping power data base. The displacement functions determined using LSS/Bethe-Bloch electronic stopping powers are 25 to 100% larger than the displacement functions determined using the electronic stopping powers generated by SRIM-96. The total number of displaced atoms determined numerically for each PKA type, based on ZBL scattering cross sections and SRIM-96 electronic stopping powers, is in excellent agreement, over the entire range of PKA energies (10 eV to 10 MeV), with the total number of displacements determined by full cascade Monte Carlo simulations using the TRIM code in SRIM-96. C1 LOS ALAMOS NATL LAB, DIV MAT SCI & TECHNOL, LOS ALAMOS, NM 87545 USA. RP Weber, WJ (reprint author), PACIFIC NW LAB, POB 999, RICHLAND, WA 99352 USA. RI Weber, William/A-4177-2008 OI Weber, William/0000-0002-9017-7365 NR 24 TC 12 Z9 12 U1 0 U2 5 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 1997 VL 244 IS 3 BP 205 EP 211 DI 10.1016/S0022-3115(96)00738-6 PG 7 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA XB871 UT WOS:A1997XB87100005 ER PT J AU Mansur, LK Farrell, K AF Mansur, LK Farrell, K TI Mechanisms of radiation-induced degradation of reactor vessel materials SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT Symposium on Radiation Materials Science in Technology Applications / Annual TMS Meeting CY FEB 04-08, 1996 CL ANAHEIM, CA SP Minerals Met & Mat Soc ID PRESSURE-VESSEL; EMBRITTLEMENT; SPECTRUM; ALLOYS; RATES AB Fast neutrons are usually considered the source of various radiation effects caused by atom displacements, such as embrittlement. swelling, and creep. However, other reactions may contribute to atom displacements under certain conditions. These additional sources of displacements include those caused by thermal neutron capture recoils, gamma-induced energetic electrons, and energetic particles emerging from transmutation reactions. In reactor vessels, for example, special circumstances may be encountered where these reactions become significant or even dominant with respect to fast-neutron-induced displacements. Key considerations describing these relative contributions are described. Inequalities are derived giving requirements among materials parameters and irradiation conditions to make each process significant with respect to fast neutrons. An example of the application of these conditions is given, covering the explanation of 'early' embrittlement in the HFIR reactor vessel. RP Mansur, LK (reprint author), OAK RIDGE NATL LAB,DIV MET & CERAM,POB 2008,OAK RIDGE,TN 37831, USA. NR 19 TC 6 Z9 6 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 1997 VL 244 IS 3 BP 212 EP 218 DI 10.1016/S0022-3115(96)00739-8 PG 7 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA XB871 UT WOS:A1997XB87100006 ER PT J AU Rice, PM Stoller, RE AF Rice, PM Stoller, RE TI The effect of solutes on defect distributions and hardening in ion-irradiated model ferritic alloys SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT Symposium on Radiation Materials Science in Technology Applications / Annual TMS Meeting CY FEB 04-08, 1996 CL ANAHEIM, CA SP Minerals Met & Mat Soc ID IRON AB A series of nine model ferritic alloys were ion irradiated at similar to 300 degrees C using 2.5 MeV He ions to a dose of 1.4 X 10(21) ion/m(2), which corresponds to similar to 0.1 dpa at a depth of 2 mu m and similar to 3.5 dpa at the peak damage region which occurs at about 3 mu m deep. The resultant changes in hardness as a function of depth were measured using a Nanoindenter(R). TEM was used to investigate the defect distributions. The effect of various solutes, Cu and N in particular, but Mn and Ti as well, on the change of hardness and the defect distribution due to the ion irradiation an discussed. RP Rice, PM (reprint author), OAK RIDGE NATL LAB,DIV MET & CERAM,POB 2008,OAK RIDGE,TN 37831, USA. RI Stoller, Roger/H-4454-2011 NR 10 TC 9 Z9 9 U1 0 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 1997 VL 244 IS 3 BP 219 EP 226 PG 8 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA XB871 UT WOS:A1997XB87100007 ER PT J AU Birtcher, RC Richardson, JW Mueller, MH AF Birtcher, RC Richardson, JW Mueller, MH TI Amorphization of U3Si by ion or neutron irradiation SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT Symposium on Radiation Materials Science in Technology Applications / Annual TMS Meeting CY FEB 04-08, 1996 CL ANAHEIM, CA SP Minerals Met & Mat Soc ID CRYSTALLINE AB Changes in crystal structure of U3Si during irradiation have been monitored by diffraction techniques. Neutron diffraction was used to follow crystallographic changes produced by uranium fission during neutron irradiation at 30 degrees C. The uranium fission fragments produce tracks of damage in the form of amorphous zones. Strain from the small volumes of amorphous material drives a transformation of the U3Si crystal structure from the tetragonal to the cubic phase. Lattice strains develop at an initial rate of (2.20 X 10(22) fissions/m(3))(-1) or (0.076 dpa)(-1), and the total lattice volume change after amorphization is +2.04b in U3Si. At high doses, plastic flow in the amorphous volume fraction relieves strain in the remaining crystalline volume fraction of U3Si. Complete amorphization of U3Si occurs between 0.85 and 1.11 x 10(23) fissions/m(3) or 0.29 to 0.38 dpa. Electron diffraction during in situ 1.5 MeV Kr ion irradiation was used to determine the doses required for amorphization of both U3Si at temperatures above 30 degrees C. As with fission fragments, individual Kr ions produce amorphous volumes that coexist with strained crystalline material. The temperature limit for complete amorphization is 290 degrees C for U3Si. The same amount of damage is required for amorphization of U3Si or U3Si2 by ion or neutron irradiation. C1 ARGONNE NATL LAB,DIV INTENSE PULSED NEUTRON SOURCE,ARGONNE,IL 60439. RP Birtcher, RC (reprint author), ARGONNE NATL LAB,DIV MAT SCI,9700 S CASS AVE,ARGONNE,IL 60439, USA. NR 29 TC 10 Z9 10 U1 0 U2 6 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 1997 VL 244 IS 3 BP 251 EP 257 DI 10.1016/S0022-3115(96)00741-6 PG 7 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA XB871 UT WOS:A1997XB87100009 ER PT J AU Weber, WJ Yu, N Wang, LM Hess, NJ AF Weber, WJ Yu, N Wang, LM Hess, NJ TI Temperature and dose dependence of ion-beam-induced amorphization in alpha-SiC SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT Symposium on Radiation Materials Science in Technology Applications / Annual TMS Meeting CY FEB 04-08, 1996 CL ANAHEIM, CA SP Minerals Met & Mat Soc ID IRRADIATION-INDUCED CRYSTALLINE; IMPLANTED SILICON-CARBIDE; TO-AMORPHOUS TRANSITION; SINGLE-CRYSTALS; DAMAGE; CERAMICS; ENERGY AB Single crystal alpha-SiC with [0001] orientation has been irradiated at 170, 300, and 370 K with 360 keV Ar2+ ions at an incident angle of 25 degrees and the damage accumulation process followed in situ by Rutherford backscattering spectroscopy in channeling geometry (RBS/C) along [1 (1) over bar 02]. At 170 and 300 K, the increase in relative disorder with ion fluence, as measured by RBS/C, is consistent with a multiple-cascade overlap process. Then is a significant deviation from the cascade overlap model at 370 K. The RBS/C results indicate that below a critical damage level the relative disordering rate is nearly temperature independent. Post-irradiation characterization of the fully disordered samples indicate a significant loss in the intensity of the Raman modes and decreases of 47 and 24% in hardness and elastic modulus, respectively, Cross sectional transmission electron microscopy has confirmed the amorphous nature of the damaged surface layer irradiated at 170 K; however, at 370 K, some residual crystallinity was observed over the depth range from 10 to 160 nm. The decrease in density associated with amorphization at 170 K is estimated to be 22 +/- 3%. C1 LOS ALAMOS NATL LAB, DIV MAT SCI & TECHNOL, LOS ALAMOS, NM 87545 USA. UNIV NEW MEXICO, DEPT EARTH & PLANETARY SCI, ALBUQUERQUE, NM 87131 USA. RP Weber, WJ (reprint author), PACIFIC NW LAB, POB 999, RICHLAND, WA 99352 USA. RI Weber, William/A-4177-2008 OI Weber, William/0000-0002-9017-7365 NR 32 TC 51 Z9 51 U1 0 U2 4 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 1997 VL 244 IS 3 BP 258 EP 265 DI 10.1016/S0022-3115(96)00742-8 PG 8 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA XB871 UT WOS:A1997XB87100010 ER PT J AU Yu, N Sickafus, KE Kodali, P Nastasi, M AF Yu, N Sickafus, KE Kodali, P Nastasi, M TI In situ observation of defect growth beyond the irradiated region in yttria-stabilized zirconia induced by 400 keV xenon ion-beam at -90 and 30 degrees C SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT Symposium on Radiation Materials Science in Technology Applications / Annual TMS Meeting CY FEB 04-08, 1996 CL ANAHEIM, CA SP Minerals Met & Mat Soc ID SPINEL; DAMAGE; MICROSTRUCTURE; CERAMICS; AMORPHIZATION; ACCUMULATION; HARDNESS; CRYSTALS AB Single crystals of yttria-stabilized zirconia (YSZ) were irradiated with 400 keV Xe ion-beam at room temperature and -90 degrees C. Defect growth was monitored in situ with Rutherford Backscattering and ion channeling (RBS/C) techniques using MeV He ion-beam. The irradiated YSZ was observed to consist of a 60 nm less-damaged or defect-denuded top layer, followed by a highly disordered layer. Ion channeling revealed that the degree of lattice disorder saturated at 70% of the random level in the bottom layer. At a dose of 3 x 10(20) Xe/m(2), this layer extended to a depth of 160 nm, well beyond the irradiated depth (< 110 nm). Cross-sectional transmission electron microscopy observations along with RES measurements are interpreted as indicating the presence of small Xe precipitates with an average diameter of 3 nm, uniformly distributed over the 20-110 nm depth. The study demonstrated that point defects generated in the Xe-irradiated region diffused and produced stable extended structural defects at depths beyond the irradiated region. C1 TEXAS INSTRUMENTS INC,SEMICOND PROC & DEVICE CTR,DALLAS,TX 75265. RP Yu, N (reprint author), LOS ALAMOS NATL LAB,DIV MAT SCI & TECHNOL,LOS ALAMOS,NM 87545, USA. NR 20 TC 51 Z9 51 U1 1 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 1997 VL 244 IS 3 BP 266 EP 272 DI 10.1016/S0022-3115(96)00743-X PG 7 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA XB871 UT WOS:A1997XB87100011 ER PT J AU Snead, CL Birtcher, RC Kirk, MA AF Snead, CL Birtcher, RC Kirk, MA TI Metastable reversal of the martensitic phase in Nb3Sn induced by energetic-electron irradiation SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT Symposium on Radiation Materials Science in Technology Applications / Annual TMS Meeting CY FEB 04-08, 1996 CL ANAHEIM, CA SP Minerals Met & Mat Soc AB Nb3Sn upon cooling undergoes a structural martensitic phase transition from the cubic A-15 structure to a tetragonal one commencing at about T-m = 50 K, with the c/a of the tetragonal structure increasing as the temperature is decreased until the ratio becomes constant at the superconducting transition temperature T-c. During electron irradiations between 0.4 and 2.0 MeV the electrical resistivity at 20 K initially decreased, contrary to experience with irradiated metals. For electron energies above the energy determined to be threshold for the production of Frenkel defects the resistivity eventually increased with increasing dose as expected. For energies below threshold, however, the resistivity approached a limiting value of about 99.6% of the initial resistivity before irradiation. The resistivity vs. temperature shows a deviation to higher-resistivity values as temperature is lowered commencing at T-m with increasing deviation as the tetragonality increases at lower temperatures. We ascribe the observed decrease in resistivity with electron irradiation to a metastable reversal of the tetragonal phase toward a state of reduced tetragonality (to cubic). This resistivity decrease is completely recovered in annealing to slightly above T-m. High-voltage electron microscopy at 12 K confirms the decrease in tetragonality by a disappearance of the twin boundaries associated with the tetragonal phase. The microstructure responsible for the resistivity changes will be discussed. C1 ARGONNE NATL LAB,DIV MAT SCI,ARGONNE,IL 60439. RP Snead, CL (reprint author), BROOKHAVEN NATL LAB,DEPT ADV TECHNOL,UPTON,NY 11973, USA. NR 9 TC 3 Z9 3 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 1997 VL 244 IS 3 BP 273 EP 277 DI 10.1016/S0022-3115(97)00004-4 PG 5 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA XB871 UT WOS:A1997XB87100012 ER PT J AU Allen, TR Was, GS Kenik, EA AF Allen, TR Was, GS Kenik, EA TI The effect of alloy composition on radiation-induced segregation in Fe-Cr-Ni alloys SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT Symposium on Radiation Materials Science in Technology Applications / Annual TMS Meeting CY FEB 04-08, 1996 CL ANAHEIM, CA SP Minerals Met & Mat Soc ID AUSTENITIC ALLOYS; STAINLESS-STEEL; TERNARY ALLOYS; IRRADIATION; DEPENDENCE; DIFFUSION AB The effect of alloy composition on radiation-induced segregation (RIS) was investigated in austenitic iron-base and nickel-base alloys using proton irradiation. Specifically, RIS was studied by irradiation of Ni-18Cr, Ni-18Cr-9Fe, and Fe-20Cr-9Ni over a dose range of 0 to 1.0 dpa and a temperature range of 200 to 500 degrees C. Grain boundary composition was measured using Auger electron spectroscopy and scanning transmission electron microscopy with energy dispersive X-ray spectroscopy. Measurements from this study along with measurements from Fe-16Cr-24Ni, Fe-20Cr-24Ni, Fe-2rCr-24Ni, and Fe-24Cr-19Ni alloys irradiated with protons confirm that RIS is strongly dependent on the alloy composition. Trends in segregation behavior in Fe-base alloys are consistent with high temperature diffusion measurements, indicating that a vacancy mechanism is the most likely primary driving force for RIS in austenitic steels. The migration energy for Cr is shown to be larger than the migration energy of Fe, Segregation measurements in Ni-base alloys are not consistent with high temperature diffusion measurements, indicating that ordering forces may be significant in the segregation process, Comparison of model calculations to measured RIS data indicate that Fe, Cr, and Ni diffusivities axe composition dependent. This dependence on alloy composition limits the predictive ability of simple models because of the need for separate diffusion parameters for every alloy composition. C1 OAK RIDGE NATL LAB,DIV MET & CERAM,OAK RIDGE,TN 37831. RP Allen, TR (reprint author), UNIV MICHIGAN,DEPT NUCL ENGN & RADIOL SCI,ANN ARBOR,MI 48109, USA. OI Allen, Todd/0000-0002-2372-7259 NR 29 TC 27 Z9 27 U1 1 U2 6 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 1997 VL 244 IS 3 BP 278 EP 294 DI 10.1016/S0022-3115(96)00744-1 PG 17 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA XB871 UT WOS:A1997XB87100013 ER PT J AU Pagano, L Motta, AT Birtcher, RC AF Pagano, L Motta, AT Birtcher, RC TI The formation of bubbles in Zr alloys under Kr ion irradiation SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT Symposium on Radiation Materials Science in Technology Applications / Annual TMS Meeting CY FEB 04-08, 1996 CL ANAHEIM, CA SP Minerals Met & Mat Soc ID SOLID KRYPTON BUBBLES; GAS-BUBBLES; RARE-GASES; PRECIPITATION; TEMPERATURES; ZIRCONIUM AB We report here a study of Kr ion implantation and resultant bubble formation in Zr and Zr alloys, including Zircaloy-2 and Zircaloy-4. Implantations into thin foils were performed in-situ in the HVEM/Tandem facility at Argonne National Laboratory at temperatures between 300 to 800 degrees C and to doses up to 2 x 10(20) ion m(-2). Bulk specimens were implanted in an ion-beam chamber and then thinned for viewing by TEM. In thin foils, only small bubbles (3-10 nm) were formed at all temperatures with the exception of the Cr-rich Valley where 13 nm bubbles were formed. Bulk samples implanted at 300 degrees C contained a bubble morphology similar to that observed after implantation into thin foils. However at high temperatures (500-800 degrees C) large faceted bubbles (up to 30 nm) were produced in bulk specimens. The results indicate that bubble formation and evolution below 500 degrees C is controlled by gas concentration, while it is controlled by bubble mobility at high temperatures. C1 PENN STATE UNIV,DEPT NUCL ENGN,UNIVERSITY PK,PA 16802. ARGONNE NATL LAB,DIV MAT SCI,ARGONNE,IL 60439. NR 29 TC 11 Z9 11 U1 1 U2 12 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 1997 VL 244 IS 3 BP 295 EP 304 DI 10.1016/S0022-3115(96)00757-X PG 10 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA XB871 UT WOS:A1997XB87100014 ER PT J AU Mansur, LK Snead, CL AF Mansur, LK Snead, CL TI Symposium on Radiation Materials Science in Technology Applications - Foreword SO JOURNAL OF NUCLEAR MATERIALS LA English DT Editorial Material C1 BROOKHAVEN NATL LAB,ENVIRONM & WASTE TECHNOL CTR,UPTON,NY 11973. RP Mansur, LK (reprint author), OAK RIDGE NATL LAB,DIV MET & CERAM,POB 2008,OAK RIDGE,TN 37831, USA. NR 0 TC 1 Z9 1 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 1997 VL 244 IS 3 BP R5 EP R5 DI 10.1016/S0022-3115(97)80011-6 PG 1 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA XB871 UT WOS:A1997XB87100001 ER PT J AU Coxson, PG Huesman, RH Borland, L AF Coxson, PG Huesman, RH Borland, L TI Consequences of using a simplified kinetic model for dynamic PET data SO JOURNAL OF NUCLEAR MEDICINE LA English DT Article DE PET; physiological models; rubidium-82; myocardial blood flow ID EMISSION COMPUTED-TOMOGRAPHY; POSITRON; QUANTITATION; RB-82; RESOLUTION; MYOCARDIUM; CAPILLARY; EXCHANGE AB We compared a physiological model of Rb-82 kinetics in the myocardium with two reduced-order models to determine their usefulness in assessing physiological parameters from dynamic PET data. Methods: A three-compartment model of Rb-82 in, the myocardium was used to simulate kinetic PET ROI data. Simulations were generated for eight different blood-flow rates reflecting the physiological range of interest. Two reduced-order models commonly used with myocardial PET studies were fit to the simulated data, and parameters of the reduced-order models were compared with the physiological parameters. Then all three models were fit to the simulated data with noise added. Monte Carlo simulations were used to evaluate and compare the diagnostic utility of the reduced-order models. A description length criterion was used to assess goodness of fit for each model. Finally, fits to simulated data were compared with fits to actual dynamic PET data. Results: Fits of the reduced-order models to the three-compartment model noise-free simulated data produced model misspecification artifacts, such as flow parameter bias and systematic variation with flow in estimates of nonflow parameters. Monte Carte simulations showed some of the parameter estimates for the two-compartment model to be highly variable al PET noise levels. Fits to actual PET data showed similar variability. One-compartment model estimates of the flow parameter at high and low flow were separated by several s.d.s for both the simulated and the real data. With the two-compartment model, the separation was about one s.d., making it difficult to differentiate a high and a low flow in a single experiment. Fixing nonflow parameters reduced flow parameter variability in the two-compartment model and did not significantly affect variability in the one-compartment model. Goodness of fit indicated that, at realistic noise levels, both reduced-order models fit the simulated data at least as well as the three-compartment model that generated the data. Conclusion: The one-compartment reduced-order model of Rb-82 dynamic PET data can be used effectively to compare myocardial blood-flow rates at rest and stress levels. The two-compartment model can differentiate flow only if a priori values are used for nonflow parameters. C1 UNIV CALIF BERKELEY,DEPT PHYS,BERKELEY,CA 94720. RP Coxson, PG (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,CTR FUNCT IMAGING,MS 55-121,1 CYCLOTRON RD,BERKELEY,CA 94720, USA. FU NHLBI NIH HHS [HL25840, HL07367, HL47675] NR 22 TC 33 Z9 35 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 1997 VL 38 IS 4 BP 660 EP 667 PG 8 WC Radiology, Nuclear Medicine & Medical Imaging SC Radiology, Nuclear Medicine & Medical Imaging GA WR377 UT WOS:A1997WR37700041 PM 9098221 ER PT J AU Duffy, PB Caldeira, K Selvaggi, J Hoffert, MI AF Duffy, PB Caldeira, K Selvaggi, J Hoffert, MI TI Effects of subgrid-scale mixing parameterizations on simulated distributions of natural C-14, temperature, and salinity in a three-dimensional ocean general circulation model SO JOURNAL OF PHYSICAL OCEANOGRAPHY LA English DT Article ID WORLD OCEAN; THERMOHALINE CIRCULATION; TRACER TRANSPORTS; BOMB RADIOCARBON; SEA-ICE; SENSITIVITY; DIFFUSIVITY; RESOLUTION; SCHEMES AB The effects of parameterizations of subgrid-scale mixing on simulated distributions of natural C-14, temperature, and salinity in a three-dimensional ocean general circulation model are examined. The parameterizations studied are 1) the Gent-McWilliams parameterization of lateral transport of tracers by isopycnal eddies; 2) horizontal mixing; 3) a parameterization of vertical mixing in which the amount of mixing depends on the local vertical density gradient; and 4) prescribed vertical mixing. The authors perform and analyze four ocean GCM simulations that use different combinations of these parameterizations. It is confirmed that the Gent-McWilliams parameterization largely eliminates the tendency of GFDL-based models to overestimate temperatures in the thermocline. However, in the authors' simulations with the Gent-McWilliams parameterization the deep ocean is too cold, in places by more than 3 degrees. Our results are the first known to assess the effects of the Gent-McWilliams parameterization on the simulated distribution of natural C-14. The most important change (compared to results obtained with horizontal mixing) is that interior ocean C-14 values are lower; that is, the water is ''older'' with Gent-McWilliams. In most locations in the deep North Atlantic, simulated Delta(14)C values are much too low with horizontal mixing and are even lower with Gent-McWilliams. Both this problem and the problem of the simulated deep ocean being too cold are probably due, at least in part, to insufficient downward penetration of NADW, resulting in the deep North Atlantic in the model being ventilated primarily via AABW. This problem exists when Gent-McWilliams is not used, but Gent-McWilliams makes the symptoms it presents (an overly cold and old deep North Atlantic) worse. Gent-McWilliams also results in a dramatic reduction in convective adjustment in the model, compared to results obtained with horizontal mixing; as a result, simulated tracer distributions are improved at high latitudes. Finally, Gent-McWilliams increases the susceptibility of the authors' model to some types of numerical problems. The stability-dependent vertical mixing parameterization causes relatively small changes in simulated distributions of temperature and natural C-14 (compared to results with a prescribed uniform vertical diffusivity), but these changes tend to improve agreement with observations. Assuming they are based on correct physical premises and are properly calibrated, both the stability-dependent vertical mixing parameterization and the Gent-McWilliams parameterization should give the model more predictive capability than simpler parameterizations do in that they allow the amount or direction of mixing to change in response to changes in ocean density. C1 NYU,DEPT PHYS,NEW YORK,NY 10003. RP Duffy, PB (reprint author), LAWRENCE LIVERMORE NATL LAB,DIV ATMOSPHER SCI,CLIMATE SYST MODELING GRP,7000 E AVE,LIVERMORE,CA 94550, USA. RI Caldeira, Ken/E-7914-2011 NR 38 TC 55 Z9 58 U1 2 U2 4 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0022-3670 J9 J PHYS OCEANOGR JI J. Phys. Oceanogr. PD APR PY 1997 VL 27 IS 4 BP 498 EP 523 DI 10.1175/1520-0485(1997)027<0498:EOSSMP>2.0.CO;2 PG 24 WC Oceanography SC Oceanography GA WT536 UT WOS:A1997WT53600002 ER PT J AU Arunsalem, V AF Arunsalem, V TI Two-stream cyclotron radiative instabilities due to the marginally mirror-trapped fraction of fusion alphas in tokamaks SO JOURNAL OF PLASMA PHYSICS LA English DT Article ID ION-CYCLOTRON; EMISSION; PRODUCTS; PLASMAS; DEUTERIUM; TRITIUM AB It is shown here that the marginally mirror-trapped fraction of newly born fusion alpha particles in deuterium-tritium (DT) reaction-dominated tokamak plasmas can induce a two-stream cyclotron radiative instability for fast Alfven waves propagating near the harmonics of the alpha-particle cyclotron frequency omega(c alpha). This can explain both the experimentally observed temporal behaviour and spatially localized origin of the fusion-product ion cyclotron emission (ICE) in TFTR at frequencies omega approximate to m omega(c alpha). RP Arunsalem, V (reprint author), PRINCETON UNIV,PRINCETON PLASMA PHYS LAB,POB 451,PRINCETON,NJ 08543, USA. NR 24 TC 4 Z9 4 U1 0 U2 1 PU CAMBRIDGE UNIV PRESS PI NEW YORK PA 40 WEST 20TH STREET, NEW YORK, NY 10011-4211 SN 0022-3778 J9 J PLASMA PHYS JI J. Plasma Phys. PD APR PY 1997 VL 57 BP 523 EP 534 DI 10.1017/S0022377897005357 PN 3 PG 12 WC Physics, Fluids & Plasmas SC Physics GA XM164 UT WOS:A1997XM16400004 ER PT J AU Rahman, HU Bhattacharya, D Rajpoot, S Amendt, P AF Rahman, HU Bhattacharya, D Rajpoot, S Amendt, P TI Diamagnetic effects during the early stages of star formation SO JOURNAL OF PLASMA PHYSICS LA English DT Article ID DIFFUSION AB The role of magnetic fields during the initial stages of protostellar cloud collapse is investigated, in particular with respect to the scenario where the magnetic force can be an effective compressor due to diamagnetic effects. A multifluid approach involving electrons, ions of different atomic masses and neutrals is adopted, where each species is treated separately The electron fluid is compressed by the magnetic pressure force, and the other ion species are pulled by the collective electric field developed by the space charge separation. The neutrals are also dragged owing to collisions with the ions. The difference in charge-to-mass ratio ensures that each ion species is accelerated differently resulting in a distribution following their atomic masses. This model explores the scenario where the electromagnetic forces can achieve a supercritical mass-to-flux ratio in a magnetized cloud before dynamical collapse due to gravity takes over. C1 CALIF STATE UNIV LONG BEACH,DEPT PHYS & ASTRON,LONG BEACH,CA 90840. LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94551. RP Rahman, HU (reprint author), UNIV CALIF RIVERSIDE,INST GEOPHYS & PLANETARY PHYS,RIVERSIDE,CA 92521, USA. NR 10 TC 3 Z9 3 U1 1 U2 1 PU CAMBRIDGE UNIV PRESS PI NEW YORK PA 40 WEST 20TH STREET, NEW YORK, NY 10011-4211 SN 0022-3778 J9 J PLASMA PHYS JI J. Plasma Phys. PD APR PY 1997 VL 57 BP 535 EP 543 DI 10.1017/S0022377897005400 PN 3 PG 9 WC Physics, Fluids & Plasmas SC Physics GA XM164 UT WOS:A1997XM16400005 ER PT J AU Crowder, SV Hawkins, DM Reynolds, MR Yashchin, E AF Crowder, SV Hawkins, DM Reynolds, MR Yashchin, E TI Process control and statistical inference SO JOURNAL OF QUALITY TECHNOLOGY LA English DT Article C1 UNIV MINNESOTA,DEPT APPL STAT,ST PAUL,MN 55108. VIRGINIA POLYTECH INST & STATE UNIV,DEPT STAT,BLACKSBURG,VA 24061. VIRGINIA POLYTECH INST & STATE UNIV,DEPT FORESTRY,BLACKSBURG,VA 24061. RP Crowder, SV (reprint author), SANDIA NATL LABS,TECH STAFF,POB 5800,ALBUQUERQUE,NM 87185, USA. NR 0 TC 20 Z9 20 U1 0 U2 1 PU AMER SOC QUALITY CONTROL-ASQC PI MILWAUKEE PA ASQC MEMBERSHIP MANAGER 611 E. WISCONSIN AVENUE, MILWAUKEE, WI 53202 SN 0022-4065 J9 J QUAL TECHNOL JI J. Qual. Technol. PD APR PY 1997 VL 29 IS 2 BP 134 EP 139 PG 6 WC Engineering, Industrial; Operations Research & Management Science; Statistics & Probability SC Engineering; Operations Research & Management Science; Mathematics GA WU848 UT WOS:A1997WU84800005 ER PT J AU Takada, T Akiba, E Izumi, F Chakoumakos, BC AF Takada, T Akiba, E Izumi, F Chakoumakos, BC TI Structure refinement of Li4Mn5O12 with neutron and X-ray powder diffraction data SO JOURNAL OF SOLID STATE CHEMISTRY LA English DT Article ID DEFECT SPINELS; SYSTEM; LIMN2O4; CELLS AB Well-crystallized Li4Mn5O12 powder was prepared by heating a eutectic mixture of lithium acetate LiOAc and manganese nitrate Mn(NO3)(2) in an O-2 atmosphere, The structure of Li4Mn5O12 crystallites was found to be cubic spinel using Rietveld refinement of both neutron and X-ray powder diffraction profiles, We confirmed that lithium ions occupy both the tetrahedral sites 8a and part of the octahedral sites 16d, but not the 16c sites in the space group Fd (3) over bar m, while all the manganese ions occupy the 16d sites, The lattice parameter was found to be sensitive to synthesis temperature as a result of the variation in manganese valence, The presence of Mn3+ leads to the formation of a stoichiometric spinel Li[LixMn2-x]O-4 in which x decreases from 1/3 (Li4Mn5O12) to 0 (LiMn2O4), with concomitant formation of Li2MnO3 depending on the synthesis conditions. (C) 1997 Academic Press. C1 NATL INST RES INORGAN MAT,TSUKUBA,IBARAKI 305,JAPAN. OAK RIDGE NATL LAB,OAK RIDGE,TN. RP Takada, T (reprint author), NATL INST MAT & CHEM RES,HIGASHI 1-1,TSUKUBA,IBARAKI 305,JAPAN. RI Chakoumakos, Bryan/A-5601-2016 OI Chakoumakos, Bryan/0000-0002-7870-6543 NR 18 TC 33 Z9 34 U1 1 U2 8 PU ACADEMIC PRESS INC JNL-COMP SUBSCRIPTIONS PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 SN 0022-4596 J9 J SOLID STATE CHEM JI J. Solid State Chem. PD APR PY 1997 VL 130 IS 1 BP 74 EP 80 DI 10.1006/jssc.1997.7282 PG 7 WC Chemistry, Inorganic & Nuclear; Chemistry, Physical SC Chemistry GA XB116 UT WOS:A1997XB11600011 ER PT J AU Balmer, ML Huang, Q WongNg, W Roth, RS Santoro, A AF Balmer, ML Huang, Q WongNg, W Roth, RS Santoro, A TI Neutron and X-ray diffraction study of the crystal structure of CsTiSi2O6.5 SO JOURNAL OF SOLID STATE CHEMISTRY LA English DT Article AB The structure of the silicotitanate CsTiSi2O6.5 has been analyzed with neutron powder and X-ray single crystal diffraction techniques. The compound crystallizes with the symmetry of space group Ia (3) over bar d and lattice parameter a = 13.8417(7) Angstrom. There are 16 formula units in the unit cell, The basic structure of the silicotitanate is similar to that of pollucite and consists of a framework of corner-sharing TO4 tetrahedra (T = 1/3 Ti+ 2/3 Si) forming large voids in which the Cs+ cations are located. Titanium and silicon are disordered over the 48g sites of the cubic space group. Compared to pollucite, there are eight extra oxygen atoms in the unit cell. These atoms partially occupy two sets of general sites and are bonded to both the cesium and the T cations of neighboring tetrahedra. (C) 1997 Academic Press. C1 UNIV MARYLAND, COLLEGE PK, MD 20742 USA. PACIFIC NW LAB, RICHLAND, WA 99352 USA. NATL INST STAND & TECHNOL, GAITHERSBURG, MD 20899 USA. NR 12 TC 18 Z9 18 U1 1 U2 3 PU ACADEMIC PRESS INC JNL-COMP SUBSCRIPTIONS PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 SN 0022-4596 J9 J SOLID STATE CHEM JI J. Solid State Chem. PD APR PY 1997 VL 130 IS 1 BP 97 EP 102 DI 10.1006/jssc.1997.7284 PG 6 WC Chemistry, Inorganic & Nuclear; Chemistry, Physical SC Chemistry GA XB116 UT WOS:A1997XB11600014 ER PT J AU He, XY Zou, QS Luo, LS Dembo, M AF He, XY Zou, QS Luo, LS Dembo, M TI Analytic solutions of simple flows and analysis of nonslip boundary conditions for the lattice Boltzmann BGK model SO JOURNAL OF STATISTICAL PHYSICS LA English DT Article DE lattice Boltzmann BGK equations; nonslip boundary conditions; analytic solutions of simple flows ID PARTICULATE SUSPENSIONS; NUMERICAL SIMULATIONS; GAS AUTOMATA; EQUATION AB In this paper we analytically solve the velocity of the lattice Boltzman BGK equation (LBGK) for several simple flows. The analysis provides a framework to theoretically analyze various boundary conditions. In particular, the analysis is used to derive the slip velocities generated by various schemes for th nonslip boundary condition. We find that the slip velocity is zero as long as Sigma(alpha)f(alpha)e(alpha) = 0 at boundaries, no matter what combination of distributions is chosen. The schemes proposed by Noble ct al. and by Inamuro et al. yield the correct zero-slip velocity, while some other schemes, such as the bounce-back scheme and the equilibrium distribution scheme, would inevitably generate a nonzero slip velocity The bounce-back scheme with the wall located halfway between a now node and a bounce-back node is also studied for the simple flows considered and is shown to produce results of second-order accuracy. The momentum exchange at boundaries seems to be highly related to the slip velocity at boundaries. To be specific, the slip velocity is zero only when the momentum dissipated by boundaries is equal to the stress provided by fluids. C1 LOS ALAMOS NATL LAB,THEORET BIOL & BIOPHYS GRP T10,DIV THEORET,LOS ALAMOS,NM 87545. LOS ALAMOS NATL LAB,DIV THEORET,COMPLEX SYST GRP T13,LOS ALAMOS,NM 87545. LOS ALAMOS NATL LAB,DIV X,COMPUTAT SCI METHODS GRP XCM,LOS ALAMOS,NM 87545. KANSAS STATE UNIV,DEPT MATH,MANHATTAN,KS 66506. NASA,LANGLEY RES CTR,ICASE,HAMPTON,VA 23681. RP He, XY (reprint author), LOS ALAMOS NATL LAB,CTR NONLINEAR STUDIES,MS-B258,LOS ALAMOS,NM 87545, USA. RI Dembo, Micah/C-2755-2013; Luo, Li-Shi/A-4561-2011 OI Luo, Li-Shi/0000-0003-1215-7892 NR 24 TC 325 Z9 349 U1 0 U2 42 PU PLENUM PUBL CORP PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 SN 0022-4715 J9 J STAT PHYS JI J. Stat. Phys. PD APR PY 1997 VL 87 IS 1-2 BP 115 EP 136 DI 10.1007/BF02181482 PG 22 WC Physics, Mathematical SC Physics GA XE284 UT WOS:A1997XE28400005 ER PT J AU Yang, ZJ AF Yang, ZJ TI Levitation force on a permanent magnet over a superconducting plane: Modified critical-state model SO JOURNAL OF SUPERCONDUCTIVITY LA English DT Article; Proceedings Paper CT 4th International Symposium on High Temperature Superconductivity in High Frequency Fields CY SEP 29-OCT 02, 1996 CL ASILOMAR, CA DE magnetic levitation; high-T-c superconductor; critical-state model; magnetic force microscope ID HIGH-TEMPERATURE SUPERCONDUCTORS; LATERAL RESTORING FORCE; HIGH-T(C) SUPERCONDUCTOR; STIFFNESS; STABILITY AB We consider a model system of a permanent magnet above a semi-infinite superconductor, introduce a modified critical-state model, and carry out derivations of the levitation force acting on the magnet. A key feature of the modification allows the current density to be less than the critical value. Theoretical results show an exponential relationship between the force acting on the magnet and the distance between the magnet and the superconductor. Analytical expressions are developed for permanent magnets in the form of a point dipole, a tip of a magnetic force microscope, and a cylindrical magnet. In the latter case, the exponential relationship has been observed in numerous experiments but without previous interpretation. C1 ARGONNE NATL LAB,ARGONNE,IL 60439. NR 25 TC 5 Z9 5 U1 0 U2 1 PU PLENUM PUBL CORP PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 SN 0896-1107 J9 J SUPERCOND JI J. Supercond. PD APR PY 1997 VL 10 IS 2 BP 137 EP 149 DI 10.1007/BF02763184 PG 13 WC Physics, Applied; Physics, Condensed Matter SC Physics GA XH434 UT WOS:A1997XH43400010 ER PT J AU VandenAbeele, KEA Johnson, PA Guyer, RA McCall, KR AF VandenAbeele, KEA Johnson, PA Guyer, RA McCall, KR TI On the quasi-analytic treatment of hysteretic nonlinear response in elastic wave propagation SO JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA LA English DT Article AB Microscopic features and their hysteretic behavior can be used to predict the macroscopic response of materials in dynamic experiments. Preisach modeling of hysteresis provides a refined procedure to obtain the stress-strain relation under arbitrary conditions, depending on the pressure history of the material. For hysteretic materials, the modulus is discontinuous at each stress-strain reversal which leads to difficulties in obtaining an analytic solution to the wave equation. Numerical implementation of the integral Preisach formulation is complicated as well. Under certain conditions an analytic expression of the modulus can be deduced from the Preisach model and an elementary description of elastic wave propagation in the presence of hysteresis can be obtained. This approach results in a second-order partial differential equation with discontinuous coefficients. Classical nonlinear representations used in acoustics can be found as limiting cases, The differential equation is solved in the frequency domain by application of Green's function theory and perturbation methods, Limitations of this quasi-analytic approach are discussed in detail. Model examples are provided illustrating the influence of hysteresis on wave propagation and are compared to simulations derived from classical nonlinear theory. Special attention is given to the role of hysteresis in nonlinear attenuation. In addition guidance is provided for inverting a set of experimental data that fall within the validity region of this theory, This work will lead to a new type of NDT characterization of materials using their nonlinear response. (C) 1997 Acoustical Society of America. C1 LOS ALAMOS NATL LAB,IGPP,LOS ALAMOS,NM 87545. CATHOLIC UNIV LEUVEN,BELGIAN FDN SCI RES,B-3000 LOUVAIN,BELGIUM. UNIV PARIS 06,LAB ACOUST PHYS,PARIS,FRANCE. UNIV MASSACHUSETTS,DEPT PHYS & ASTRON,AMHERST,MA. UNIV NEVADA,DEPT PHYS,RENO,NV 89557. RP VandenAbeele, KEA (reprint author), LOS ALAMOS NATL LAB,EES 4,MS D443,POB 1663,LOS ALAMOS,NM 87545, USA. NR 33 TC 102 Z9 106 U1 1 U2 12 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0001-4966 J9 J ACOUST SOC AM JI J. Acoust. Soc. Am. PD APR PY 1997 VL 101 IS 4 BP 1885 EP 1898 DI 10.1121/1.418198 PG 14 WC Acoustics; Audiology & Speech-Language Pathology SC Acoustics; Audiology & Speech-Language Pathology GA WV173 UT WOS:A1997WV17300011 ER PT J AU Bamberger, CE AF Bamberger, CE TI Homogeneity ranges of phases Sr(4-x)Ln(2x/3)Ti(4)O(12) (Ln=Sm to Lu) and (Sr1-yEuyTiO3)-Ti-II SO JOURNAL OF THE AMERICAN CERAMIC SOCIETY LA English DT Article AB The homogeneity ranges of phases Sr(4-x)Ln(2x/3)Ti(4)O(12), in which Ln = Sm to Lu, have been established using X-ray diffraction (XRD) analysis. It was found that the maximum value of x is dependent on the ionic radius of the lanthanide element. The effect of hydrogen reduction on single-phase and multiphasic preparations containing Sr-Eu(III) titanates has been studied. The replacement of the lanthanide element in such Sr-Ln compounds by a mixture of two lanthanides that have an average ionic radius similar to the single lanthanide was examined. RP Bamberger, CE (reprint author), OAK RIDGE NATL LAB,DIV CHEM & ANALYT SCI,OAK RIDGE,TN 37831, USA. NR 6 TC 4 Z9 4 U1 0 U2 0 PU AMER CERAMIC SOC PI WESTERVILLE PA 735 CERAMIC PLACE, PO BOX 6136, WESTERVILLE, OH 43081-6136 SN 0002-7820 J9 J AM CERAM SOC JI J. Am. Ceram. Soc. PD APR PY 1997 VL 80 IS 4 BP 1024 EP 1026 PG 3 WC Materials Science, Ceramics SC Materials Science GA WV760 UT WOS:A1997WV76000029 ER PT J AU Campisi, J AF Campisi, J TI Aging and cancer: The double-edged sword of replicative senescence SO JOURNAL OF THE AMERICAN GERIATRICS SOCIETY LA English DT Article ID CYCLE-DEPENDENT GENES; HUMAN-FIBROBLASTS; MALIGNANT TRANSFORMATION; CELLULAR SENESCENCE; G(1) PROGRESSION; TISSUE INHIBITOR; BREAST-CANCER; CELLS; EXPRESSION; TELOMERES AB Normal cells do not divide indefinitely. This trait, termed the finite replicative life span of cells, limits the capacity for cell division by a process termed cellular or replicative senescence. Replicative senescence is thought to be a tumor suppression mechanism and also a contributor to organismic aging. This article reviews what is known about the genetics and molecular biology of cell senescence. It discusses the evidence that replicative senescence suppresses tumorigenesis, at least in young organisms, and that it also contributes to the aging of mitotic tissues. Finally, it puts forth the somewhat unorthodox view that, in older organisms, senescent cells may actually contribute to carcinogenesis. RP Campisi, J (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DEPT CANC BIOL,MAILSTOP 70A-1118,1 CYCLOTRON RD,BERKELEY,CA 94720, USA. FU NIA NIH HHS [AG09909, AG11658] NR 52 TC 111 Z9 114 U1 0 U2 1 PU WILLIAMS & WILKINS PI BALTIMORE PA 351 WEST CAMDEN ST, BALTIMORE, MD 21201-2436 SN 0002-8614 J9 J AM GERIATR SOC JI J. Am. Geriatr. Soc. PD APR PY 1997 VL 45 IS 4 BP 482 EP 488 PG 7 WC Geriatrics & Gerontology; Gerontology SC Geriatrics & Gerontology GA WT160 UT WOS:A1997WT16000014 PM 9100719 ER PT J AU Medforth, CJ Muzzi, CM Shea, KM Smith, KM Abraham, RJ Jia, SL Shelnutt, JA AF Medforth, CJ Muzzi, CM Shea, KM Smith, KM Abraham, RJ Jia, SL Shelnutt, JA TI NMR studies of nonplanar porphyrins .1. Axial ligand orientations in highly nonplanar porphyrins SO JOURNAL OF THE CHEMICAL SOCIETY-PERKIN TRANSACTIONS 2 LA English DT Article ID CYTOCHROMES-B; NICKEL(II) PORPHYRINS; MOSSBAUER-SPECTRA; CURRENT MODEL; COMPLEXES; RESONANCE; STEREOCHEMISTRY; DEACTIVATION; CALIBRATION; OXIDATION AB The ligand orientations in the nonplanar porphyrin complexes 1a-e and 2a-e have been investigated using molecular mechanics calculations and proton NMR spectroscopy. The minimum energy structures calculated for complexes 1a-e show that the planes of the axial pyridine or imidazole ligands are orientated approximately parallel to the Co-III-N-porphyrin bonds, with the ligand ring planes being perpendicular to each other. For complexes 2a-e, the planes of the axial ligands in the calculated minimum energy structures are orientated along the porphyrin meso carbon axis and the ligand ring planes are perpendicular to each other. Thus, for both series of complexes the planes of the axial ligands are orientated parallel to cavities formed by these very nonplanar porphyrins. Proton NMR studies suggest that structures similar to those obtained from the molecular mechanics calculations are retained in solution. In some complexes, hindered rotation of the axial ligands is also observed. Complexes la-e and 2a-e are unusual examples of the porphyrin conformation influencing the orientations of axial ligands and, as such, may be useful as models for studying ligand orientation effects in relation to biological systems. C1 UNIV LIVERPOOL,SCH CHEM,LIVERPOOL L69 3BX,MERSEYSIDE,ENGLAND. SANDIA NATL LABS,FUEL SCI DEPT,ALBUQUERQUE,NM 87185. RP Medforth, CJ (reprint author), UNIV CALIF DAVIS,DEPT CHEM,DAVIS,CA 95616, USA. 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 32 TC 39 Z9 39 U1 0 U2 8 PU ROYAL SOC CHEMISTRY PI CAMBRIDGE PA THOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON ROAD, CAMBRIDGE, CAMBS, ENGLAND CB4 4WF SN 0300-9580 J9 J CHEM SOC PERK T 2 JI J. Chem. Soc.-Perkin Trans. 2 PD APR PY 1997 IS 4 BP 833 EP 837 DI 10.1039/a603412h PG 5 WC Chemistry, Organic; Chemistry, Physical SC Chemistry GA WU620 UT WOS:A1997WU62000028 ER PT J AU Medforth, CJ Muzzi, CM Shea, KM Smith, KM Abraham, RJ Jia, SL Shelnutt, JA AF Medforth, CJ Muzzi, CM Shea, KM Smith, KM Abraham, RJ Jia, SL Shelnutt, JA TI NMR studies of nonplanar porphyrins .2. Effect of nonplanar conformational distortions on the porphyrin ring current SO JOURNAL OF THE CHEMICAL SOCIETY-PERKIN TRANSACTIONS 2 LA English DT Article ID CURRENT MODEL; MESO-TETRAPHENYLPORPHYRIN; BACTERIOCHLOROPHYLLIDE-D; NICKEL(II) PORPHYRINS; SPECTRA; COMPLEXES; AGGREGATION; CALIBRATION; TEMPERATURE; CATION AB The ring currents in the sterically congested and highly nonplanar porphyrin complexes 1a and 2a have been investigated using a double-dipole model of the porphyrin ring current effect, The equivalent dipoles needed to simulate the ring current in the saddle-shaped complex 1a were indistinguishable from those previously determined for the planar or nearly planar complex 3a, A 5% decrease in the equivalent dipoles was required to reproduce the ring current shifts in the ruffled complex 2a, The extremely large nonplanar conformational distortions seen for the porphyrin macrocycles in complexes la and 2a thus seem to cause little decrease in the porphyrin ring currents measured by this empirical model. C1 UNIV LIVERPOOL,SCH CHEM,LIVERPOOL L69 3BX,MERSEYSIDE,ENGLAND. SANDIA NATL LABS,DEPT FUEL SCI,ALBUQUERQUE,NM 87185. RP Medforth, CJ (reprint author), UNIV CALIF DAVIS,DEPT CHEM,DAVIS,CA 95616, USA. 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 48 TC 34 Z9 34 U1 0 U2 6 PU ROYAL SOC CHEMISTRY PI CAMBRIDGE PA THOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON ROAD, CAMBRIDGE, CAMBS, ENGLAND CB4 4WF SN 0300-9580 J9 J CHEM SOC PERK T 2 JI J. Chem. Soc.-Perkin Trans. 2 PD APR PY 1997 IS 4 BP 839 EP 844 DI 10.1039/a603413f PG 6 WC Chemistry, Organic; Chemistry, Physical SC Chemistry GA WU620 UT WOS:A1997WU62000029 ER PT J AU Vallet, CE Tilak, BV Zuhr, RA Chen, CP AF Vallet, CE Tilak, BV Zuhr, RA Chen, CP TI Rutherford backscattering spectroscopic study of the failure mechanism of (RuO2+TiO2)/Ti thin film electrodes in H2SO4 solutions SO JOURNAL OF THE ELECTROCHEMICAL SOCIETY LA English DT Article ID MIXED-OXIDE ELECTRODES; SURFACE CHARACTERIZATION; TITANIUM ELECTRODES; IMPLANTED TITANIUM; XPS; LAYERS; EVOLUTION; AUGER; IRO2; RU AB RuO2-TiO2 electrodes 5000 Angstrom thick, which mimic the dimensionally stable anodes in composition and the method of preparation, were prepared and tested for their activity toward the chlorine evolution reaction and subjected to lifetime testing in sulfuric acid solution. Rutherford backscattering spectrometry was used concurrently with electrochemical measurements to analyze the changes in the ruthenium content of the coating. The decrease in electrode activity was found to be closely linked to a decrease in the Ru content, and the measured profiles indicate that the loss takes place across the thin coating. Failure is observed for electrodes with a Ru content below the critical concentration of 3 x 10(21) Ru atom/cm(3), but there is no evidence for the buildup of a pure TiO2 layer. C1 OCCIDENTAL CHEM CORP,GRAND ISL,NY 14072. RP Vallet, CE (reprint author), OAK RIDGE NATL LAB,OAK RIDGE,TN 37831, USA. NR 32 TC 23 Z9 25 U1 1 U2 5 PU ELECTROCHEMICAL SOC INC PI PENNINGTON PA 10 SOUTH MAIN STREET, PENNINGTON, NJ 08534 SN 0013-4651 J9 J ELECTROCHEM SOC JI J. Electrochem. Soc. PD APR PY 1997 VL 144 IS 4 BP 1289 EP 1295 DI 10.1149/1.1837586 PG 7 WC Electrochemistry; Materials Science, Coatings & Films SC Electrochemistry; Materials Science GA WX090 UT WOS:A1997WX09000039 ER PT J AU Umino, S Newman, J AF Umino, S Newman, J TI Temperature dependence of the diffusion coefficient of sulfuric acid in water SO JOURNAL OF THE ELECTROCHEMICAL SOCIETY LA English DT Article AB The method of restricted diffusion has been applied to aqueous sulfuric acid in order to determine differential diffusion coefficients spanning the composition range from 0.5 to 5.5 M, at temperatures between 0 and 35 degrees C. Rayleigh interferometry was used for measuring concentration differences with time. The following expression summarizes the experimental data D=exp[C-0(1/T-1/298.15)]C-1 cm(2)/s where C-0=exp{7.699+0.2352[1-exp(-12c(1/2))]-0.2977c+0.04164c(3/2)+0.02023c(2)} C-1=exp{-10.56-0.3665[1-exp(-12c(1/2))]-0.1107c+0.2888c(3/2)-0.09151c(2)} and c is in mol/liter (M). The activation energy of diffusion corresponds to the average value of the activation energy between solvent-anion and solvent-cation interactions. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV ENERGY & ENVIRONM,BERKELEY,CA 94720. UNIV CALIF BERKELEY,DEPT CHEM ENGN,BERKELEY,CA 94720. RI Newman, John/B-8650-2008 OI Newman, John/0000-0002-9267-4525 NR 14 TC 4 Z9 4 U1 0 U2 7 PU ELECTROCHEMICAL SOC INC PI PENNINGTON PA 10 SOUTH MAIN STREET, PENNINGTON, NJ 08534 SN 0013-4651 J9 J ELECTROCHEM SOC JI J. Electrochem. Soc. PD APR PY 1997 VL 144 IS 4 BP 1302 EP 1307 DI 10.1149/1.1837588 PG 6 WC Electrochemistry; Materials Science, Coatings & Films SC Electrochemistry; Materials Science GA WX090 UT WOS:A1997WX09000041 ER PT J AU Griffiths, SK Nilson, RH AF Griffiths, SK Nilson, RH TI Deposition uniformity, particle nucleation, and the optimum conditions for chemical vapor deposition in multiwafer furnaces SO JOURNAL OF THE ELECTROCHEMICAL SOCIETY LA English DT Article ID LPCVD REACTORS; SILICON; MODEL AB A second-order perturbation solution describing the radial transport of a reactive species and concurrent deposition on wafer surfaces is derived for use in optimizing chemical vapor deposition process conditions. The result is applicable to various deposition reactions and accounts for both diffusive and advective transport, as well as both ordinary and Knudsen diffusion. Based on the first-order approximation, the deposition rate is maximized subject to a constraint on the radial uniformity of the deposition rate. For a fixed reactant mole fraction, the optimum pressure and optimum temperature are obtained using the method of Lagrange multipliers. This yields a weak one-sided maximum; deposition rates fall as pressures are reduced but remain nearly constant at all pressures above the optimum value. The deposition rate is also maximized subject to dual constraints on the uniformity and particle nucleation rate. In this case, the optimum pressure, optimum temperature, and optimum reactant fraction are similarly obtained, and the resulting maximum deposition rate is well defined. RP Griffiths, SK (reprint author), SANDIA NATL LABS,LIVERMORE,CA 94551, USA. NR 24 TC 3 Z9 3 U1 0 U2 0 PU ELECTROCHEMICAL SOC INC PI PENNINGTON PA 10 SOUTH MAIN STREET, PENNINGTON, NJ 08534 SN 0013-4651 J9 J ELECTROCHEM SOC JI J. Electrochem. Soc. PD APR PY 1997 VL 144 IS 4 BP 1399 EP 1410 DI 10.1149/1.1837602 PG 12 WC Electrochemistry; Materials Science, Coatings & Films SC Electrochemistry; Materials Science GA WX090 UT WOS:A1997WX09000055 ER PT J AU Lee, JW Abernathy, CR Pearton, SJ Ren, F Hobson, WS Shul, RJ Constantine, C Barratt, C AF Lee, JW Abernathy, CR Pearton, SJ Ren, F Hobson, WS Shul, RJ Constantine, C Barratt, C TI Inductively coupled plasma etch damage in GaAs and InP Schottky diodes SO JOURNAL OF THE ELECTROCHEMICAL SOCIETY LA English DT Article ID GAN; ALN AB The effects of ion-induced damage in n- and p-type GaAs and p-type InP exposed to inductively coupled plasma (ICP) Ar discharges were measured by diode ideality factor and barrier height measurements. At fixed RF chuck powers, the electrical characteristics of the diodes generally improve with increasing ICP source power because the incident ion energy is decreased. In the particular case of p-GaAs, the higher ion flux at high-ICP source power leads to a degradation in barrier height. Exposure time and ion energy have a stronger influence than ion flux in all three materials. The results are compared to those obtained with electron cyclotron resonance Ar plasmas and show the same basic trends. The clear result is that at moderate ICP source powers, the suppression of self-induced de bias on the powered electrode leads to a lower amount of ion damage to the semiconductors than for conventional reactive ion etch discharges. C1 AT&T BELL LABS,LUCENT TECHNOL,MURRAY HILL,NJ 07974. SANDIA NATL LABS,ALBUQUERQUE,NM 87185. PLASMA THERM IP,ST PETERSBURG,FL 33716. RP Lee, JW (reprint author), UNIV FLORIDA,DEPT MAT SCI & ENGN,GAINESVILLE,FL 32611, USA. NR 25 TC 8 Z9 8 U1 0 U2 1 PU ELECTROCHEMICAL SOC INC PI PENNINGTON PA 10 SOUTH MAIN STREET, PENNINGTON, NJ 08534 SN 0013-4651 J9 J ELECTROCHEM SOC JI J. Electrochem. Soc. PD APR PY 1997 VL 144 IS 4 BP 1417 EP 1422 DI 10.1149/1.1837604 PG 6 WC Electrochemistry; Materials Science, Coatings & Films SC Electrochemistry; Materials Science GA WX090 UT WOS:A1997WX09000057 ER PT J AU Vosen, SR Meeks, E Larson, RS Shon, JW AF Vosen, SR Meeks, E Larson, RS Shon, JW TI Simulation of chemical downstream etch systems - Correlation of the effects of operating conditions on wafer etch rate and uniformity SO JOURNAL OF THE ELECTROCHEMICAL SOCIETY LA English DT Article ID FLUORINE-ATOMS; VAPOR-DEPOSITION; SILICON AB A detailed chemically reacting flow model has been used to predict the performance and operating characteristics of chemical downstream etch (CDE) tools. In CDE systems, wafer etching is accomplished by neutral reactive gases. In practice CDE systems consist of a plasma source, a chemically inert (''transport'') tub, a showerhead, and an etch chamber. The model describes each step of the process in sufficient detail to predict its performance, including ion concentration, wafer etch rate, and nonuniformity. Model validation was accomplished through comparison of etch rates and nonuniformity of blanket polysilicon and silicon dioxide wafers in a CDE tool from Matrix Integrated Systems, Inc., using NF3/O-2 gas mixtures at conditions representative of normal tool use. This study is primarily concerned with the effects ol operating parameters on the etch rate and nonuniformity, and thus focuses mainly on etch chamber calculations. The model provides an indication of system performance, predicting from first principles, etch rates to within 30% of measured values. Correlation of system performance is obtained from calculations of etch rate resulting from changes in pressure, flow rate, plasma power, and system geometry. Correlations of performance highlight the importance of controllable parameters and etchant concentration on etch rate and nonuniformity. In addition, the etch chamber ion concentration is predicted to be less than 10(8) cm(-3). RP Vosen, SR (reprint author), SANDIA NATL LABS,LIVERMORE,CA 94551, USA. NR 24 TC 5 Z9 5 U1 0 U2 3 PU ELECTROCHEMICAL SOC INC PI PENNINGTON PA 10 SOUTH MAIN STREET, PENNINGTON, NJ 08534 SN 0013-4651 J9 J ELECTROCHEM SOC JI J. Electrochem. Soc. PD APR PY 1997 VL 144 IS 4 BP 1514 EP 1521 DI 10.1149/1.1837620 PG 8 WC Electrochemistry; Materials Science, Coatings & Films SC Electrochemistry; Materials Science GA WX090 UT WOS:A1997WX09000073 ER PT J AU Domansky, K Li, J Janata, J AF Domansky, K Li, J Janata, J TI Selective doping of chemically sensitive layers on a multisensing chip SO JOURNAL OF THE ELECTROCHEMICAL SOCIETY LA English DT Letter ID POLYANILINE; FILMS AB A method of selectively doping the polyaniline gates of chemically sensitive field-effect transistors (CHEMFETs) has been demonstrated. Activated and inactivated gates located on the same chip were exposed to a solution containing palladium. The activated gate was doped by palladium by the electroless relaxation process I,ut the inactivated gate was not modified. High selectivity of the doping process was proved by exposing the devices to hydrogen. The method has potential applications in manufacturing single-chip heterogeneous microsensor arrays. RP Domansky, K (reprint author), PACIFIC NW LAB, ENVIRONM MOL SCI LAB, RICHLAND, WA 99352 USA. NR 13 TC 18 Z9 18 U1 0 U2 1 PU ELECTROCHEMICAL SOC INC PI PENNINGTON PA 10 SOUTH MAIN STREET, PENNINGTON, NJ 08534 SN 0013-4651 J9 J ELECTROCHEM SOC JI J. Electrochem. Soc. PD APR PY 1997 VL 144 IS 4 BP L75 EP L78 PG 4 WC Electrochemistry; Materials Science, Coatings & Films SC Electrochemistry; Materials Science GA WX090 UT WOS:A1997WX09000011 ER PT J AU Yang, M Reilly, PTA Gieray, RA Whitten, WB Ramsey, JM AF Yang, M Reilly, PTA Gieray, RA Whitten, WB Ramsey, JM TI Complete chemical analysis of aerosol particles in real-time SO JOURNAL OF THE KOREAN PHYSICAL SOCIETY LA English DT Article; Proceedings Paper CT 4th Symposium on Laser Spectroscopy CY NOV 08-09, 1996 CL KOREA ATOM ENERGY RES INST, TAEJON, SOUTH KOREA SP Korea Atom Energy Res Inst HO KOREA ATOM ENERGY RES INST ID FLIGHT MASS-SPECTROMETRY; DAILY MORTALITY; AIR-POLLUTION; MICROPARTICLES; IONIZATION AB Real-time mass spectrometry of individual aerosol particles using an ion trap mass spectrometer is described. The microparticles are sampled directly from the air by a particle inlet system fed into a vacuum chamber. An incoming particle is detected as it passes through two CW laser beams and a pulsed laser is triggered to intercept the particle for laser ablation ionization at the center of the ion trap. The produced ions are analyzed by the ion trap mass spectrometer. Ions of interest are selected and dissociated through collision with buffer gas atoms for further fragmentation analysis. Real-time chemical analyses of inorganic, organic and bacterial aerosol particles have been demonstrated. It has been confirmed that the velocity and the size of the incoming particles highly correlate to each other. The performance of the inlet system, particle detection and preliminary results are discussed. RP Yang, M (reprint author), OAK RIDGE NATL LAB,DIV CHEM & ANALYT SCI,OAK RIDGE,TN 37831, USA. NR 20 TC 8 Z9 8 U1 0 U2 2 PU KOREAN PHYSICAL SOC PI SEOUL PA 635-4, YUKSAM-DONG, KANGNAM-KU, SEOUL 135-703, SOUTH KOREA SN 0374-4884 J9 J KOREAN PHYS SOC JI J. Korean Phys. Soc. PD APR PY 1997 VL 30 IS 2 BP 359 EP 363 PN 2 PG 5 WC Physics, Multidisciplinary SC Physics GA WU182 UT WOS:A1997WU18200002 ER PT J AU Kircher, J Henn, R Cardona, M Richards, PL Williams, GP AF Kircher, J Henn, R Cardona, M Richards, PL Williams, GP TI Far-infrared ellipsometry using synchrotron radiation SO JOURNAL OF THE OPTICAL SOCIETY OF AMERICA B-OPTICAL PHYSICS LA English DT Article ID TEMPERATURE-DEPENDENCE; DIELECTRIC FUNCTION; SINGLE-CRYSTALS; CHARGE DYNAMICS; C-AXIS; SUPERCONDUCTORS; LA2CUO4 AB We discuss ellipsometric measurements using synchrotron radiation and estimate the errors that are due to focusing light onto the sample. Our results lead to the conclusion that ellipsometry is a brightness experiment and can benefit considerably from the use of synchrotron radiation in the mid and far infrared. We report implementation of a synchrotron far-infrared ellipsometer at the U4IR beam line at the National Synchrotron Light Source, Brookhaven National Laboratory, covering the 50-700-cm(-1) wave-number range. To illustrate the capability of our setup we have determined the complex dielectric function bf the ionic insulator LiF and of the heavily doped semiconductor GaAs (n approximate to 8 x 10(18) cm(-3)). We also report direct measurements of the optical interplane conductivity of single crystalline La2CuO4+delta and a twinned YBa2Cu3O7 crystal. From these data, dynamic atomic effective charges have been determined for La2CuO4+delta. (C) 1997 Optical Society of America. C1 UNIV CALIF BERKELEY,DEPT PHYS,BERKELEY,CA 94720. UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV MAT SCI,BERKELEY,CA 94720. BROOKHAVEN NATL LAB,NATL SYNCHROTRON LIGHT SOURCE DEPT,UPTON,NY 11973. RP Kircher, J (reprint author), MAX PLANCK INST FESTKORPERFORSCH,HEISENBERGSTR 1,D-70569 STUTTGART,GERMANY. NR 38 TC 37 Z9 37 U1 2 U2 6 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 SN 0740-3224 J9 J OPT SOC AM B JI J. Opt. Soc. Am. B-Opt. Phys. PD APR PY 1997 VL 14 IS 4 BP 705 EP 712 DI 10.1364/JOSAB.14.000705 PG 8 WC Optics SC Optics GA WU017 UT WOS:A1997WU01700003 ER PT J AU Kane, DJ Rodriguez, G Taylor, AJ Clement, TS AF Kane, DJ Rodriguez, G Taylor, AJ Clement, TS TI Simultaneous measurement of two ultrashort laser pulses from a single spectrogram in a single shot SO JOURNAL OF THE OPTICAL SOCIETY OF AMERICA B-OPTICAL PHYSICS LA English DT Article ID GENERALIZED PROJECTIONS; PHASE; RETRIEVAL; INTENSITY; AMPLITUDE AB Frequency-resolved optical gating (FROG) is a technique that produces a spectrogram of an ultrashort laser pulse. The intensity and phase of the ultrashort laser pulse can be determined through solving for the phase of the spectrogram with an iterative, phase-retrieval algorithm. This work presents a pew phase-retrieval algorithm that retrieves both the probe and the gate pulses independently by converting the FROG phase-retrieval problem to an eigenvector problem. The new algorithm is robust and general, It is tested theoretically by use of synthetic data sets and experimentally by use of single-shot, polarization-gate FROG. We independently and simultaneously characterize the electric field amplitude and phase of a pulse (probe) that was passed though 200 mm of BK7 glass and the amplitude of an unchanged pulse (gate) from an amplified Ti:sapphire laser. When the effect of the 200 mm of BK7 glass; was removed mathematically from the probe, there was good agreement between the measured gate and the calculated, prechirped probe. (C) 1997 Optical Society of America. C1 LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545. NATL INST STAND & TECHNOL,BOULDER,CO 80303. UNIV COLORADO,JOINT INST LAB ASTROPHYS,BOULDER,CO 80309. RP Kane, DJ (reprint author), SW SCI INC,1570 PACHECO ST,SUITE E-11,SANTA FE,NM 87505, USA. RI Clement, Tracy/A-8885-2008; Rodriguez, George/G-7571-2012 OI Rodriguez, George/0000-0002-6044-9462 NR 21 TC 62 Z9 64 U1 1 U2 7 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 SN 0740-3224 J9 J OPT SOC AM B JI J. Opt. Soc. Am. B-Opt. Phys. PD APR PY 1997 VL 14 IS 4 BP 935 EP 943 DI 10.1364/JOSAB.14.000935 PG 9 WC Optics SC Optics GA WU017 UT WOS:A1997WU01700031 ER PT J AU Kuroiwa, Y Konishi, A Shobu, T Noda, Y Fuchizaki, K Morii, Y Yamada, Y Child, HR Chou, H Moss, SC AF Kuroiwa, Y Konishi, A Shobu, T Noda, Y Fuchizaki, K Morii, Y Yamada, Y Child, HR Chou, H Moss, SC TI Elastic and inelastic neutron scattering studies on the martensitic phase transformation in Cu-39at%Zn alloy SO JOURNAL OF THE PHYSICAL SOCIETY OF JAPAN LA English DT Article DE CuZn; martensitic transformation; lattice dynamics; precursor phenomena; neutron inelastic scattering ID AUCUZN2; LITHIUM; BCC AB Neutron scattering studies have been performed to elucidate the martensitic transformation mechanism in a quenched Cu61Zn39 alloy. The TA(1)[110] phonon branch (e//[1 (1) over bar 0]) showed slight softening over the entire q-region in the parent phase as the transformation temperature was approached on cooling. No particular dip was observed even just above the transformation temperature, while the intensities of the quasi-elastic diffuse scattering developed near q = 1/6[1 (1) over bar 0] and 1/3[1 (1) over bar 0] positions in the parent phase. No anomaly was found in several other phonon branches. The structure of the beta(1) '' martensite phase was investigated, and a mixed phase of an orthorhombic structure and a monoclinic structure is proposed, which are both different from the previously reported structures. An annealing effect was observed to confirm the role of inclusions in the parent phase. C1 JAPAN ATOM ENERGY RES INST, NEUTRON SCATTERING LAB, TOKAI, IBARAKI 31911, JAPAN. KYUSHU UNIV, FAC SCI, HAKOZAKI, FUKUOKA 812, JAPAN. WASEDA UNIV, ADV RES CTR SCI & ENGN, SHINJUKU KU, TOKYO 169, JAPAN. OAK RIDGE NATL LAB, DIV SOLID STATE, OAK RIDGE, TN 37831 USA. BROOKHAVEN NATL LAB, DEPT PHYS, UPTON, NY 11973 USA. UNIV HOUSTON, DEPT PHYS, HOUSTON, TX 77204 USA. RP CHIBA UNIV, FAC SCI, INAGE KU, YAYOI, CHIBA 263, JAPAN. NR 30 TC 1 Z9 1 U1 1 U2 6 PU PHYSICAL SOC JAPAN PI TOKYO PA YUSHIMA URBAN BUILDING 5F, 2-31-22 YUSHIMA, BUNKYO-KU, TOKYO, 113-0034, JAPAN SN 0031-9015 J9 J PHYS SOC JPN JI J. Phys. Soc. Jpn. PD APR PY 1997 VL 66 IS 4 BP 1033 EP 1043 DI 10.1143/JPSJ.66.1033 PG 11 WC Physics, Multidisciplinary SC Physics GA WX080 UT WOS:A1997WX08000028 ER PT J AU Lamoreaux, SK Ignatovich, VK AF Lamoreaux, SK Ignatovich, VK TI Tidal pressure induced neutrino emission as an energy dissipation mechanism in binary pulsar systems SO JOURNAL OF THE PHYSICAL SOCIETY OF JAPAN LA English DT Article DE binary pulsar; neutrino; dissipation; general relativity ID PSR-1913+16 AB We briefly review possible systematic limitations to inferred General Relativity tests in binary pulsar systems, then propose a new mechanism whereby orbital energy can be dissipated. The basic idea is that tidal pressure fluctuations can drive the electron-proton vs. neutron density away from equilibrium, and the concomitant neutrino (or antineutrino) emission represents an orbital energy dissipation. Of the total orbital energy loss rate, we estimate the fractional contribution of this mechanism as 8 x 10(-6), whereas the observational accuracy is at the level of 7 x 10(-3), and agrees with the predicted rate of gravitational radiation. C1 KYOTO UNIV, INST RES REACTOR, KUMATORI, OSAKA 59004, JAPAN. RP Lamoreaux, SK (reprint author), LOS ALAMOS NATL LAB, DIV P23, MS H803, LOS ALAMOS, NM 87544 USA. NR 13 TC 0 Z9 0 U1 0 U2 0 PU PHYSICAL SOC JAPAN PI TOKYO PA YUSHIMA URBAN BUILDING 5F, 2-31-22 YUSHIMA, BUNKYO-KU, TOKYO, 113-0034, JAPAN SN 0031-9015 J9 J PHYS SOC JPN JI J. Phys. Soc. Jpn. PD APR PY 1997 VL 66 IS 4 BP 1225 EP 1228 DI 10.1143/JPSJ.66.1225 PG 4 WC Physics, Multidisciplinary SC Physics GA WX080 UT WOS:A1997WX08000056 ER PT J AU Pederson, NA Jones, RH Sharitz, RR AF Pederson, NA Jones, RH Sharitz, RR TI Age structure and possible origins of old Pinus taeda stands in a floodplain forest SO JOURNAL OF THE TORREY BOTANICAL SOCIETY LA English DT Article DE loblolly pine; Congaree Swamp National Monument; Pinus taeda; Hurricane Hugo; forest succession; disturbance; regeneration ID SOUTH-CAROLINA; COMPETITION; GROWTH AB Stand structure and ages were measured in six old stands of Pinus taeda L. (loblolly pine) and one younger stand within Congaree Swamp National Monument, South Carolina. Dominant overstory species included loblolly pine, shade intolerant hardwoods and tolerant hardwoods. All overstory species except pine also occurred in the sapling layer Five of the six old stands had two or more pine age classes. All but one individual pine was less than 200 years old. According to estimates of future survival, current loblolly pine seedling densities in recently hurricane-disturbed and clearcut areas are inadequate to reproduce tree densities measured in extant old stands. Spatial distributions of mature trees suggest that pines have established in gaps as large as 0.3 ha and as small as a single overstory tree. No evidence of fire (scars on existing trees or charcoal in the upper 10 cm of soil) was found in any old stand. From these results, we speculate that the old loblolly pine stands in Congaree Swamp resulted from small-scale agricultural activities, although wind storms, fires, or combinations of these may have played contributing roles. Because of its apparent ability to regenerate in gaps, loblolly pine will probably remain in Congaree Swamp for several centuries as small clumps and scattered individuals. C1 SAVANNAH RIVER ECOL LAB,AIKEN,SC 29802. UNIV GEORGIA,DEPT BOT,ATHENS,GA 30602. AUBURN UNIV,SCH FORESTRY,AUBURN,AL 36849. VIRGINIA POLYTECH INST & STATE UNIV,DEPT BIOL,BLACKSBURG,VA 24061. NR 41 TC 11 Z9 13 U1 1 U2 7 PU TORREY BOTANICAL SOCIETY PI LAWRENCE PA 810 EAST 10TH ST, LAWRENCE, KS 66044 SN 0040-9618 J9 J TORREY BOT SOC JI J. Torrey Bot. Soc. PD APR-JUN PY 1997 VL 124 IS 2 BP 111 EP 123 DI 10.2307/2996579 PG 13 WC Plant Sciences SC Plant Sciences GA XL158 UT WOS:A1997XL15800001 ER PT J AU Nguyen, HD Paik, S Douglass, RW AF Nguyen, HD Paik, S Douglass, RW TI Double-diffusive convection in a porous trapezoidal enclosure with oblique principal axes SO JOURNAL OF THERMOPHYSICS AND HEAT TRANSFER LA English DT Article ID NATURAL-CONVECTION; MEDIA RP Nguyen, HD (reprint author), IDAHO NATL ENGN LAB,POB 1625,M-S 3808,IDAHO FALLS,ID 83415, USA. NR 13 TC 2 Z9 2 U1 0 U2 1 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091 SN 0887-8722 J9 J THERMOPHYS HEAT TR JI J. Thermophys. Heat Transf. PD APR-JUN PY 1997 VL 11 IS 2 BP 309 EP 312 DI 10.2514/2.6240 PG 4 WC Thermodynamics; Engineering, Mechanical SC Thermodynamics; Engineering GA WU625 UT WOS:A1997WU62500027 ER PT J AU Ling, GV Case, LC Nelson, H Harrold, DR Johnson, DL Vulliet, PR AF Ling, GV Case, LC Nelson, H Harrold, DR Johnson, DL Vulliet, PR TI Pharmacokinetics of allopurinol in Dalmatian dogs SO JOURNAL OF VETERINARY PHARMACOLOGY AND THERAPEUTICS LA English DT Article ID URIC-ACID; XANTHINE AB The pharmacokinetics of allopurinol were studied in Dalmatian dogs. Eight dogs were given allopurinol orally at a dose of 10 mg/kg for seven doses prior to sample collection. After a period of at. least two weeks, four of these dogs and four additional Dalmatians were later given a single intravenous (i.v.) dose of allopurinol (6 mg/kg) prior to sample collection. Allopurinol was found to follow first-order absorption and elimination kinetics. In the i.v. kinetic study, the elimination constant (K-cl) = 0.31 +/- 0.03 per h, the half-life (t(1/2)) = 2.22 +/- 0.20 h, the initial concentration (C-O) = 5.26 +/- 0.34 mu g/mL, and the specific volume (V-d) = 1.14 +/- 0.07 L/kg. Clearance of allopurinol was estimated to be 0.36 +/- 0.03 L/kg.h. In the oral kinetic study, the absorption rate constant (K-ab) = 1.06 +/- 0.13 per h, the elimination rate constant (K-el) = 0.26 +/- 0.01 per h, the absorption half-life (t(1/2ab)) = 0.66 +/- 0.06 h, and the elimination half-life (t(1/2el)) = 2.69 +/- 0.14 h. Peak plasma concentrations (C-max) = 6.43 +/- 0.18 mu g/mL were obtained within 1 to 3 h (mean time of maximum concentration (T-max) = 1.9 +/- 0.1 h). The volume of distribution corrected by the fraction of dose absorbed (V-d/F) was estimated to be 1.17 +/- 0.07 L/kg. Good agreement was obtained between mean kinetic parameters in the oral and i.v. studies. There was little variation between individual dogs in the i.v. study, whereas the rate of absorption and elimination of orally administered allopurinol was more varied among individual dogs. Because of this, and the fact that the magnitude of hyperuricosuria varies among Dalmatians, it is not possible to specify an exact dose of allopurinol that will effectively lower the urinary uric acid concentration to acceptable values in all Dalmatians with hyperuricosuria; rather, the dose must be titrated to the needs of each dog. C1 LAWRENCE LIVERMORE NATL LAB,SCH VET MED,DEPT MOL BIOSCI,DAVIS,CA 95616. CAMERON PK VET HOSP,SHINGLE SPRINGS,CA 95682. RP Ling, GV (reprint author), LAWRENCE LIVERMORE NATL LAB,SCH VET MED,DEPT MED & EPIDEMIOL,DAVIS,CA 95616, USA. NR 20 TC 7 Z9 7 U1 0 U2 0 PU BLACKWELL SCIENCE LTD PI OXFORD PA P O BOX 88, OSNEY MEAD, OXFORD, OXON, ENGLAND OX2 0NE SN 0140-7783 J9 J VET PHARMACOL THER JI J. Vet. Pharmacol. Ther. PD APR PY 1997 VL 20 IS 2 BP 134 EP 138 DI 10.1046/j.1365-2885.1997.00817.x PG 5 WC Pharmacology & Pharmacy; Veterinary Sciences SC Pharmacology & Pharmacy; Veterinary Sciences GA WU179 UT WOS:A1997WU17900008 PM 9131540 ER PT J AU Okazaki, I Wunderlich, B AF Okazaki, I Wunderlich, B TI Reversible local melting in polymer crystals SO MACROMOLECULAR RAPID COMMUNICATIONS LA English DT Article; Proceedings Paper CT 4th Lahnwitz Seminar CY JUN, 1996 CL KRUGSDORF, GERMANY ID DIFFERENTIAL SCANNING CALORIMETRY; MOLECULAR SEGREGATION; NUCLEATION; TEMPERATURE AB The melting of poly(ethylene terephthalate) is analyzed by quasi-isothermal, temperature-modulated differential scanning calorimetry. The measurement is done by sinusoidally changing the temperature in the melting range (+/-1.0 K). In the melting range a small portion of the sample melts reversibly. This observation is taken as a direct observation of the reversibility of melting of specific macromolecules as long as they are melting only partially and need no molecular nucleation for recrystallization. C1 OAK RIDGE NATL LAB,DIV CHEM & ANALYT SCI,OAK RIDGE,TN 37831. RP Okazaki, I (reprint author), UNIV TENNESSEE,DEPT CHEM,KNOXVILLE,TN 37996, USA. NR 16 TC 75 Z9 75 U1 0 U2 5 PU HUTHIG & WEPF VERLAG PI BASEL PA AUF DEM WOLF 4, CH-4052 BASEL, SWITZERLAND SN 1022-1336 J9 MACROMOL RAPID COMM JI Macromol. Rapid Commun. PD APR PY 1997 VL 18 IS 4 BP 313 EP 318 DI 10.1002/marc.1997.030180407 PG 6 WC Polymer Science SC Polymer Science GA WW083 UT WOS:A1997WW08300007 ER PT J AU Boyd, PW Aiken, J Kolber, Z AF Boyd, PW Aiken, J Kolber, Z TI Comparison of radiocarbon and fluorescence based (pump and probe) measurements of phytoplankton photosynthetic characteristics in the Northeast Atlantic Ocean SO MARINE ECOLOGY PROGRESS SERIES LA English DT Article DE photosynthetic characteristics; intercomparison; active fluorescence; radiotracer methods; photoacclimation ID STEADY-STATE PHOTOSYNTHESIS; PHOTOSYSTEM-II; PRIMARY PRODUCTIVITY; ENERGY-CONVERSION; EUKARYOTIC ALGAE; IRRADIANCE; PHOTOADAPTATION; BLOOM; COCCOLITHOPHORE; CHLOROPHYLL AB Significant advances in rapid non-destructive means of measuring the photosynthetic energy conversion of phytoplankton in the ocean have been made in recent years. The new techniques offer the potential to obtain detailed spatial and temporal information about photosynthetic rates that cannot be achieved using more traditional methods. A study of a mesoscale coccolithophore bloom in the Northeast Atlantic enabled the comparison of photosynthetic parameters derived from the Pump and Probe Fluorometer (PPF) and C-14 photosynthesis vs irradiance (P vs I) incubations over a wide variety of biological, optical and physical conditions. A comparison of the photosynthetic characteristics obtained from the instantaneous PPF and time-integrated C-14 approaches demonstrated correlations between parameters, although the absolute values were significantly different. Significant correlations were observed for both I-k and P-m, while the light-dependent rate constant a was not significant despite a strong correlation between C-14-derived alpha and PPF measurements of the efficiency of photoconversion, Delta phi(m). The primary reason for the observed discrepancies in the absolute values derived from the 2 approaches were the spectral differences between the artificial light source used for the C-14 incubations and the natural underwater light in which the PPF measurements were made. Future studies must consider and correct, via normalization, for such spectral differences. Although the dataset was limited, there was some indication that photoacclimation of the phytoplankton assemblage may have occurred during the 2 h C-14 incubations that took place late in the day. The use of the PPF approach is promising with regard to extending the measurement of photosynthetic characteristics on to the temporal and spatial scales required for the development of more robust bio-optical models and to complement currently available in situ measurement rates of physical and chemical parameters. C1 QUEENS UNIV BELFAST, SCH BIOL & BIOCHEM, MARINE BIOL STN, PORTAFERRY BT22 1PF, DOWN, NORTH IRELAND. PLYMOUTH MARINE LAB, PLYMOUTH PL1 3DH, DEVON, ENGLAND. BROOKHAVEN NATL LAB, DIV OCEANOG & ATMOSPHER SCI, UPTON, NY 11973 USA. RI Boyd, Philip/J-7624-2014 OI Boyd, Philip/0000-0001-7850-1911 NR 46 TC 30 Z9 31 U1 0 U2 2 PU INTER-RESEARCH PI OLDENDORF LUHE PA NORDBUNTE 23, D-21385 OLDENDORF LUHE, GERMANY SN 0171-8630 J9 MAR ECOL PROG SER JI Mar. Ecol.-Prog. Ser. PD APR PY 1997 VL 149 IS 1-3 BP 215 EP 226 DI 10.3354/meps149215 PG 12 WC Ecology; Marine & Freshwater Biology; Oceanography SC Environmental Sciences & Ecology; Marine & Freshwater Biology; Oceanography GA XA146 UT WOS:A1997XA14600019 ER PT J AU Fry, DA AF Fry, DA TI Russian/US nuclear weapons labs share NDT technologies for emergency response SO MATERIALS EVALUATION LA English DT Article RP Fry, DA (reprint author), LOS ALAMOS NATL LAB,ENGN SCI & APPLICAT DIV,MEASUREMENT TECHNOL GRP,MS C931,LOS ALAMOS,NM 87545, USA. NR 3 TC 1 Z9 1 U1 0 U2 0 PU AMER SOC NON-DESTRUCTIVE TEST PI COLUMBUS PA 1711 ARLINGATE LANE PO BOX 28518, COLUMBUS, OH 43228-0518 SN 0025-5327 J9 MATER EVAL JI Mater. Eval. PD APR PY 1997 VL 55 IS 4 BP 475 EP 478 PG 4 WC Materials Science, Characterization & Testing SC Materials Science GA WR867 UT WOS:A1997WR86700006 ER PT J AU Gualtieri, A Norby, P Artioli, G Hanson, J AF Gualtieri, A Norby, P Artioli, G Hanson, J TI Kinetic study of hydroxysodalite formation from natural kaolinites by time-resolved synchrotron powder diffraction SO MICROPOROUS MATERIALS LA English DT Article DE kaolinite; hydroxysodalite; time-resolved powder diffraction; synchrotron radiation; kinetics ID MULLITE REACTION SEQUENCE; AUTOCATALYTIC NUCLEATION; ZEOLITE CRYSTALLIZATION; SODALITE; MODEL AB Real-time synchrotron powder diffraction was employed to investigate the crystallization process of hydroxysodalite (SOD) from natural kaolinites, The powder diffraction experiments were carried out in isothermal mode using a transmission geometry with capillary samples, and an image plate detector. Natural kaolinites with different densities of planar disorder were thermally activated at 800 degrees C to obtain precursor materials for the syntheses. The metakaolinite precursor was also prepared from the ordered kaolinite at 600 degrees C. The hydrothermal syntheses were accomplished by leaching the activated precursor materials with a 1 M NaOH solution at temperatures in the range from 100 to 130 degrees C. The analysis of the isothermal runs permits calculation of the kinetic parameters and interpretation of the mechanism of hydroxysodalite formation in the light of the structural state of the precursor material. At 100 degrees C, prior to the crystallization of hydroxysodalite, zeolite A (LTA) is formed as an intermediate metastable phase. The mechanisms of nucleation and competing growth of the two zeolites are interpreted on the basis of the obtained kinetic parameters, and of the structural relationship between the two phases. C1 BROOKHAVEN NATL LAB,DEPT CHEM,UPTON,NY 11973. UNIV MILAN,DIPARTIMENTO SCI TERRA,I-20133 MILAN,ITALY. RP Gualtieri, A (reprint author), UNIV MODENA,DIPARTIMENTO SCI TERRA,VIA S EUFEMIA 19,I-41100 MODENA,ITALY. RI Hanson, jonathan/E-3517-2010; Artioli, Gilberto/F-2149-2015; Gualtieri, Alessandro/L-9680-2015; Norby, Poul/B-9047-2014 OI Artioli, Gilberto/0000-0002-8693-7392; Gualtieri, Alessandro/0000-0002-4414-9603; Norby, Poul/0000-0002-2590-7050 NR 34 TC 28 Z9 28 U1 1 U2 11 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0927-6513 J9 MICROPOROUS MATER JI Microporous Mater. PD APR PY 1997 VL 9 IS 3-4 BP 189 EP 201 DI 10.1016/S0927-6513(96)00111-3 PG 13 WC Chemistry, Applied; Chemistry, Physical; Materials Science, Multidisciplinary SC Chemistry; Materials Science GA WZ452 UT WOS:A1997WZ45200009 ER PT J AU Handler, G Pikall, H ODonoghue, D Buckley, DAH Vauclair, G Chevreton, M Giovannini, O Kepler, SO Goode, PR Provencal, JL Wood, MA Clemens, JC OBrien, MS Nather, RE Winget, DE Kleinman, SJ Kanaan, A Watson, TK Nitta, A Montgomery, MH Klumpe, EW Bradley, PA Sullivan, DJ Wu, K Marar, TMK Seetha, S Ashoka, BN Mahra, HS Bhat, BC Babu, VC Leibowitz, EM Hemar, S Ibbetson, PA Mashal, E Meistas, EG Dziembowski, WA Pamyatnykh, AA Moskalik, P Zola, S Pajdosz, G Krzesinski, J Solheim, JE Bard, S Massacand, CM Breger, M Gelbmann, MJ Paunzen, E North, P AF Handler, G Pikall, H ODonoghue, D Buckley, DAH Vauclair, G Chevreton, M Giovannini, O Kepler, SO Goode, PR Provencal, JL Wood, MA Clemens, JC OBrien, MS Nather, RE Winget, DE Kleinman, SJ Kanaan, A Watson, TK Nitta, A Montgomery, MH Klumpe, EW Bradley, PA Sullivan, DJ Wu, K Marar, TMK Seetha, S Ashoka, BN Mahra, HS Bhat, BC Babu, VC Leibowitz, EM Hemar, S Ibbetson, PA Mashal, E Meistas, EG Dziembowski, WA Pamyatnykh, AA Moskalik, P Zola, S Pajdosz, G Krzesinski, J Solheim, JE Bard, S Massacand, CM Breger, M Gelbmann, MJ Paunzen, E North, P TI New Whole Earth Telescope observations of CD-24 7599: Steps towards delta Scuti star seismology SO MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY LA English DT Article DE techniques, photometric; stars, fundamental parameters; stars, individual, CD-24 7599; stars, oscillations; delta Scuti ID A-TYPE STARS; CALIBRATIONS; PARAMETERS; PULSATION AB 92 h of new Whole Earth Telescope observations have been acquired for the delta Scuti star CD-24 7599. All the seven pulsation modes reported by Handler et al. are confirmed. However, significant amplitude variations which are not caused by beating of closely spaced frequencies occurred within two years. Analysing the combined data of both WET runs, we detect six further pulsation modes, bringing the total number up to 13. We also examine our data for high-frequency pulsations similar to those exhibited by rapidly oscillating Ap stars, but we do not find convincing evidence for variability in this frequency domain. C1 UNIV CAPE TOWN,DEPT ASTRON,ZA-7700 RONDEBOSCH,SOUTH AFRICA. S AFRICAN ASTRON OBSERV,ZA-7935 CAPE TOWN,SOUTH AFRICA. OBSERV MIDI PYRENEES,F-31400 TOULOUSE,FRANCE. OBSERV PARIS,F-92195 MEUDON,FRANCE. UNIV FED RIO GRANDE SUL,INST FIS,BR-91501970 PORTO ALEGRE,RS,BRAZIL. NEW JERSEY INST TECHNOL,DEPT PHYS,NEWARK,NJ 07102. UNIV DELAWARE,DEPT PHYS & ASTRON,NEWARK,DE 19716. FLORIDA INST TECHNOL,DEPT PHYS & SPACE SCI,MELBOURNE,FL 32901. IOWA STATE UNIV,DEPT PHYS & ASTRON,AMES,IA 50211. UNIV TEXAS,DEPT ASTRON,AUSTIN,TX 78712. UNIV TEXAS,MCDONALD OBSERV,AUSTIN,TX 78712. LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545. VICTORIA UNIV WELLINGTON,DEPT PHYS,WELLINGTON,NEW ZEALAND. AUSTRALIAN NATL UNIV,DEPT MATH,CANBERRA,ACT,AUSTRALIA. ISRO SATELLITE CTR,INDIAN SPACE RES ORG,TECH PHYS DIV,BANGALORE 560017,KARNATAKA,INDIA. TEL AVIV UNIV,SACKLER FAC EXACT SCI,WISE OBSERV,IL-69978 TEL AVIV,ISRAEL. INST THEORET PHYS & ASTRON,LT-2600 VILNIUS,LITHUANIA. COPERNICUS ASTRON CTR,PL-00716 WARSAW,POLAND. INST ASTRON,MOSCOW 109017,RUSSIA. KRAKOW PEDAGOG UNIV,MT SUHORA OBSERV,PL-30084 KRAKOW,POLAND. UNIV TROMSO,NORDLYSOBSERV,INST MATEMAT REALFAG,N-9000 TROMSO,NORWAY. UNIV LAUSANNE,INST ASTRON,CH-1290 CHAVANNES BOIS,SWITZERLAND. RP Handler, G (reprint author), UNIV VIENNA,INST ASTRON,TURKENSCHANZSTR 17,A-1180 VIENNA,AUSTRIA. RI Kepler, S. O. /H-5901-2012; Paunzen, Ernst/M-3050-2016 OI Kepler, S. O. /0000-0002-7470-5703; Paunzen, Ernst/0000-0002-3304-5200 NR 32 TC 50 Z9 50 U1 0 U2 1 PU BLACKWELL SCIENCE LTD PI OXFORD PA P O BOX 88, OSNEY MEAD, OXFORD, OXON, ENGLAND OX2 0NE SN 0035-8711 J9 MON NOT R ASTRON SOC JI Mon. Not. Roy. Astron. Soc. PD APR 1 PY 1997 VL 286 IS 2 BP 303 EP 314 PG 12 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA WV688 UT WOS:A1997WV68800008 ER PT J AU Alcock, C Allsman, RA Alves, D Axelrod, TS Bennett, DP Charles, PA Cook, KH Freeman, KC Griest, K Guern, J Lehner, MJ Livio, M Marshall, SL Peterson, BA Pratt, MR Quinn, PJ Rodgers, AW Southwell, KA Stubbs, CW Sutherland, W AF Alcock, C Allsman, RA Alves, D Axelrod, TS Bennett, DP Charles, PA Cook, KH Freeman, KC Griest, K Guern, J Lehner, MJ Livio, M Marshall, SL Peterson, BA Pratt, MR Quinn, PJ Rodgers, AW Southwell, KA Stubbs, CW Sutherland, W TI The X-ray off-state of the supersoft source CAL 83 and its interpretation SO MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY LA English DT Article DE accretion, accretion discs; binaries, close; binaries, spectroscopic stars, individual, CAL 83; X-rays, stars ID LARGE MAGELLANIC CLOUD; WHITE-DWARF MODELS; NOVAE AB We consider simultaneous optical data obtained during the recent X-ray turn-off of CAL 83. Combining the optical behaviour with the observed X-ray decay time, we show that a model of cessation of steady nuclear burning is viable if the white dwarf is massive. Our model provides a natural explanation for the subsequent return of the supersoft X-ray emission. C1 UNIV CALIF BERKELEY, CTR PARTICLE ASTROPHYS, BERKELEY, CA 94720 USA. AUSTRALIAN NATL UNIV, SUPERCOMP FACIL, CANBERRA, ACT 0200, AUSTRALIA. AUSTRALIAN NATL UNIV, MT STROMLO & SIDING SPRING OBSERV, WESTON, ACT 2611, AUSTRALIA. UNIV OXFORD, DEPT ASTROPHYS, NUCL & ASTROPHYS LAB, OXFORD OX1 3RH, ENGLAND. UNIV CALIF SAN DIEGO, DEPT PHYS, SAN DIEGO, CA 92093 USA. SPACE TELESCOPE SCI INST, BALTIMORE, MD 21218 USA. UNIV CALIF SANTA BARBARA, DEPT PHYS, SANTA BARBARA, CA 93106 USA. UNIV WASHINGTON, DEPT ASTRON, SEATTLE, WA 98195 USA. UNIV WASHINGTON, DEPT PHYS, SEATTLE, WA 98195 USA. RP Alcock, C (reprint author), LAWRENCE LIVERMORE NATL LAB, LIVERMORE, CA 94550 USA. RI Stubbs, Christopher/C-2829-2012; Quinn, Peter/B-3638-2013; OI Stubbs, Christopher/0000-0003-0347-1724; Lehner, Matthew/0000-0003-4077-0985 NR 22 TC 15 Z9 15 U1 0 U2 1 PU WILEY-BLACKWELL PI MALDEN PA COMMERCE PLACE, 350 MAIN ST, MALDEN 02148, MA USA SN 0035-8711 J9 MON NOT R ASTRON SOC JI Mon. Not. Roy. Astron. Soc. PD APR 1 PY 1997 VL 286 IS 2 BP 483 EP 486 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA WV688 UT WOS:A1997WV68800024 ER PT J AU Smolarkiewicz, PK Grubisic, V Margolin, LG AF Smolarkiewicz, PK Grubisic, V Margolin, LG TI On forward-in-time differencing for fluids: Stopping criteria for iterative solutions of anelastic pressure equations SO MONTHLY WEATHER REVIEW LA English DT Article ID COORDINATE TRANSFORMATION; CONVECTION; ALGORITHM; SYSTEMS AB In this note, the authors address the practical issue of selecting appropriate stopping criteria for iterative solutions to the elliptic pressure equation arising in nonoscillatory, forward-in-time Eulerian and semi-Lagrangian anelastic fluid models. Using the simple computational example of 2D thermal convection in a neutrally stratified Boussinesq fluid, it is shown that (a) converging to the machine precision is not necessary for the overall accuracy and stability of the model, and adversely affects the overall model efficiency; and (b) the semi-Lagrangian model algorithm admits fairly liberal stopping criteria compared to the Eulerian flux-form model, unless the latter is formulated in terms of field perturbations. C1 LOS ALAMOS NATL LAB,LOS ALAMOS,NM. RP Smolarkiewicz, PK (reprint author), NATL CTR ATMOSPHER RES,MMM,POB 3000,BOULDER,CO 80307, USA. NR 24 TC 51 Z9 51 U1 0 U2 2 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0027-0644 J9 MON WEATHER REV JI Mon. Weather Rev. PD APR PY 1997 VL 125 IS 4 BP 647 EP 654 DI 10.1175/1520-0493(1997)125<0647:OFITDF>2.0.CO;2 PG 8 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA WP480 UT WOS:A1997WP48000016 ER PT J AU Kaufmann, EN AF Kaufmann, EN TI Materials chemistry: Subarea or semantics? SO MRS BULLETIN LA English DT Letter RP Kaufmann, EN (reprint author), ARGONNE NATL LAB,ARGONNE,IL 60439, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DR, WARRENDALE, PA 15086 SN 0883-7694 J9 MRS BULL JI MRS Bull. PD APR PY 1997 VL 22 IS 4 BP 3 EP 3 PG 1 WC Materials Science, Multidisciplinary; Physics, Applied SC Materials Science; Physics GA WU801 UT WOS:A1997WU80100002 ER PT J AU Clinard, FW AF Clinard, FW TI Materials performance in a radiation environment SO MRS BULLETIN LA English DT Article RP Clinard, FW (reprint author), LOS ALAMOS NATL LAB,MAIL STOP K762,LOS ALAMOS,NM 87545, USA. NR 0 TC 2 Z9 2 U1 0 U2 2 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DR, WARRENDALE, PA 15086 SN 0883-7694 J9 MRS BULL JI MRS Bull. PD APR PY 1997 VL 22 IS 4 BP 11 EP 13 PG 3 WC Materials Science, Multidisciplinary; Physics, Applied SC Materials Science; Physics GA WU801 UT WOS:A1997WU80100015 ER PT J AU Prince, RC George, GN AF Prince, RC George, GN TI The remarkable complexity of hydroxylamine oxidoreductase SO NATURE STRUCTURAL BIOLOGY LA English DT Article ID NITROSOMONAS-EUROPAEA; RHODOPSEUDOMONAS-VIRIDIS; REDOX POTENTIOMETRY; ACTIVE-SITE; RESOLUTION; CYTOCHROME; HEMES; SPECTROSCOPY; RESONANCE AB Hydroxylamine oxidoreductase performs the second step in the oxidation of ammonium to nitrite, a critical part of the nitrogen cycle. Its structure reveals a complex arrangement of haems that could serve to direct electrons along two separate pathways. C1 STANFORD SYNCHROTRON RADIAT LAB,STANFORD,CA 94309. RP Prince, RC (reprint author), EXXON RES & ENGN CO,ROUTE 22 E,ANNANDALE,NJ 08801, USA. RI George, Graham/E-3290-2013; OI Prince, Roger/0000-0002-5174-4216 NR 23 TC 16 Z9 17 U1 0 U2 7 PU NATURE PUBLISHING CO PI NEW YORK PA 345 PARK AVE SOUTH, NEW YORK, NY 10010-1707 SN 1072-8368 J9 NAT STRUCT BIOL JI Nat. Struct. Biol. PD APR PY 1997 VL 4 IS 4 BP 247 EP 250 DI 10.1038/nsb0497-247 PG 4 WC Biochemistry & Molecular Biology; Biophysics; Cell Biology SC Biochemistry & Molecular Biology; Biophysics; Cell Biology GA WQ977 UT WOS:A1997WQ97700002 PM 9095186 ER PT J AU Li, HL Lee, S Jap, BK AF Li, HL Lee, S Jap, BK TI Molecular design of aquaporin-1 water channel as revealed by electron crystallography SO NATURE STRUCTURAL BIOLOGY LA English DT Letter ID CELL CHIP28 PROTEIN; PURPLE MEMBRANE; RECONSTITUTION; PROJECTION; RESOLUTION; MICROSCOPY; MODEL; CDNA AB The electron crystallographic structure of the aquaporin-1 water channel, determined at similar to 6 Angstrom, reveals that the protein has six transmembrane alpha-helices forming a trapezoid-like cylinder. There is a branched rod-like structure within the cylinder that traverses the membrane and likely contains at least one alpha-helix. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV LIFE SCI,BERKELEY,CA 94720. NR 23 TC 99 Z9 108 U1 0 U2 3 PU NATURE PUBLISHING CO PI NEW YORK PA 345 PARK AVE SOUTH, NEW YORK, NY 10010-1707 SN 1072-8368 J9 NAT STRUCT BIOL JI Nat. Struct. Biol. PD APR PY 1997 VL 4 IS 4 BP 263 EP 265 DI 10.1038/nsb0497-263 PG 3 WC Biochemistry & Molecular Biology; Biophysics; Cell Biology SC Biochemistry & Molecular Biology; Biophysics; Cell Biology GA WQ977 UT WOS:A1997WQ97700008 PM 9095192 ER PT J AU Tolman, JR Flanagan, JM Kennedy, MA Prestegard, JH AF Tolman, JR Flanagan, JM Kennedy, MA Prestegard, JH TI NMR evidence for slow collective motions in cyanometmyoglobin SO NATURE STRUCTURAL BIOLOGY LA English DT Article ID NUCLEAR-MAGNETIC-RESONANCE; INELASTIC NEUTRON-SCATTERING; MYOGLOBIN; DYNAMICS; RESOLUTION; PROTEINS; SPECTRA; FIELD; MACROMOLECULES; SIMULATIONS AB Residual dipolar couplings observed in NMR spectra at very high magnetic fields have been measured to a high degree of accuracy for the paramagnetic protein cyanometmyoglobin. Deviations of these measurements from predictions based on available crystallographic and solution structures are largely systematic and well correlated within a given helix of this highly alpha-helical protein. These observations can be explained by invoking collective motion and small displacements of representative helices from their reported average positions in the solid state, Thus, the measurements appear to be capable of providing important insights into slower, collective protein motions, which are likely to be important for function, and which have been difficult to study using established experimental techniques. C1 YALE UNIV, DEPT CHEM, NEW HAVEN, CT 06520 USA. BROOKHAVEN NATL LAB, DEPT BIOL, UPTON, NY 11937 USA. PACIFIC NW LAB, RICHLAND, WA 99352 USA. NR 33 TC 237 Z9 239 U1 1 U2 14 PU NATURE PUBLISHING CO PI NEW YORK PA 345 PARK AVE SOUTH, NEW YORK, NY 10010-1707 SN 1072-8368 J9 NAT STRUCT BIOL JI Nat. Struct. Biol. PD APR PY 1997 VL 4 IS 4 BP 292 EP 297 DI 10.1038/nsb0497-292 PG 6 WC Biochemistry & Molecular Biology; Biophysics; Cell Biology SC Biochemistry & Molecular Biology; Biophysics; Cell Biology GA WQ977 UT WOS:A1997WQ97700013 PM 9095197 ER PT J AU Patel, BP Wessel, J Yao, WB Lee, JC Peris, E Koetzle, TF Yap, GPA Fortin, JB Ricci, JS Sini, G Albinati, A Eisenstein, O Rheingold, AL Crabtree, RH AF Patel, BP Wessel, J Yao, WB Lee, JC Peris, E Koetzle, TF Yap, GPA Fortin, JB Ricci, JS Sini, G Albinati, A Eisenstein, O Rheingold, AL Crabtree, RH TI Intermolecular N-H center dot center dot center dot H-Re interactions involving rhenium polyhydrides SO NEW JOURNAL OF CHEMISTRY LA English DT Article ID MOLECULAR-STRUCTURE; HYDROGEN-BOND; COMPLEXES; IR; CRYSTAL AB Intramolecular H...H interactions between hydrogen-bond proton donors and transition metal hydrides can be extended to intermolecular cases by cocrystallization of ReH5(PPh3)(2)L and suitable hydrogen-bond donors, as is shown in the neutron and X-ray crystal structures of 6 (L = PPh3; donor = indole) and 7 (L = imidazole; donor = lattice imidazole of solvation), respectively. Short N-H...H-Re distances are found for these unconventional hydrogen bonds in both cases: 6, 1.734(8) Angstrom; 7, 1.68(3) Angstrom (sum of van der Waals radii for H...H = 2.4 Angstrom). IR data indicate a correlation between the pK(a) of the hydrogen-bond donor and the strengths of the H...H interactions. DFT calculations on ReH5(PH3)(3) . NH3 show the presence of a significant attractive interaction between the rhenium fragment and the proton donor, independent of the Re-H bonds chosen. Experimentally, the least hindered Re hydride is involved in the interaction in each case. The influence of the occupied metal d orbital (Re(V), d(2)) is minimal. Molecules like OPPh3 that can act as a hydrogen-bond acceptor do not show an attractive interaction with the Re complex, as confirmed by the absence of an attractive potential between ReH5(PH3)(3) and OPH3. C1 BROOKHAVEN NATL LAB,UPTON,NY 11973. UNIV JAUME 1,DEPT QUIM ORGAN & INORGAN,E-12080 CASTELLO DE PLANA,SPAIN. YALE UNIV,NEW HAVEN,CT 06520. UNIV DELAWARE,NEWARK,DE 19716. UNIV SO MAINE,PORTLAND,ME 04103. UNIV CERGY PONTOISE,F-95806 CERGY,FRANCE. UNIV MILAN,INST PHARMACEUT CHEM,I-20131 MILAN,ITALY. UNIV MONTPELLIER 2,LAB STRUCT & DYNAM SYST MOL & SOLIDES,UMR 5636,F-34905 MONTPELLIER 5,FRANCE. RI Peris, Eduardo/C-8608-2013; Eisenstein, Odile/I-1704-2016; Albinati, Alberto/I-1262-2015 OI Peris, Eduardo/0000-0001-9022-2392; Eisenstein, Odile/0000-0001-5056-0311; Albinati, Alberto/0000-0002-8779-3327 NR 31 TC 28 Z9 28 U1 1 U2 7 PU GAUTHIER-VILLARS PI PARIS PA 120 BLVD SAINT-GERMAIN, 75280 PARIS, FRANCE SN 1144-0546 J9 NEW J CHEM JI New J. Chem. PD APR PY 1997 VL 21 IS 4 BP 413 EP 421 PG 9 WC Chemistry, Multidisciplinary SC Chemistry GA WZ770 UT WOS:A1997WZ77000003 ER PT J AU Lenhart, S Protopopescu, V Szpiro, AA AF Lenhart, S Protopopescu, V Szpiro, AA TI Optimal control for competing coalitions SO NONLINEAR ANALYSIS-THEORY METHODS & APPLICATIONS LA English DT Article DE reaction-diffusion (R-D) equations; competitive systems; optimal control ID PARABOLIC-SYSTEMS C1 UNIV TENNESSEE,DEPT MATH,KNOXVILLE,TN 37996. UNIV CALIF SAN DIEGO,LA JOLLA,CA 92092. RP Lenhart, S (reprint author), OAK RIDGE NATL LAB,DIV MATH & COMP SCI,OAK RIDGE,TN 37831, USA. NR 25 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 0362-546X J9 NONLINEAR ANAL-THEOR JI Nonlinear Anal.-Theory Methods Appl. PD APR PY 1997 VL 28 IS 8 BP 1411 EP 1428 DI 10.1016/0362-546X(95)00227-M PG 18 WC Mathematics, Applied; Mathematics SC Mathematics GA WB995 UT WOS:A1997WB99500007 ER PT J AU Korsah, K Antonescu, C AF Korsah, K Antonescu, C TI Evaluating 'new' instrumentation and control technologies for safety-related applications in nuclear power plants SO NUCLEAR ENGINEERING AND DESIGN LA English DT Article AB As obsolescence and spare parts issues drive nuclear power plants to upgrade with new technologies (such as optical fiber communication systems), the ability of the new technologies to withstand environmental stresses that act at the installation location needs to be determined. New standards may be required to address environmental qualification and their application to the nuclear power plants of tomorrow. This article discusses the failure modes and age-related degradation mechanisms relevant to fiber-optic communication systems in particular, and suggests a methodology for identifying conditions under which accelerated aging should be performed during qualification testing. While optical fiber communication systems have been used as the basis for discussion, the methodology presented should be applicable to any safety-related instrumentation and control equipment not covered under Title 10 of the Code of Federal Regulations (10 CFR 50.49). (C) 1997 Elsevier Science S.A. C1 NRC,OFF NUCL REGULATORY RES,BETHESDA,MD 20852. RP Korsah, K (reprint author), OAK RIDGE NATL LAB,POB 2008,OAK RIDGE,TN 37831, USA. NR 20 TC 1 Z9 1 U1 1 U2 1 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0029-5493 J9 NUCL ENG DES JI Nucl. Eng. Des. PD APR PY 1997 VL 167 IS 3 BP 251 EP 265 DI 10.1016/S0029-5493(96)01306-4 PG 15 WC Nuclear Science & Technology SC Nuclear Science & Technology GA XD222 UT WOS:A1997XD22200002 ER PT J AU Korth, GE Diercks, DR Neimark, LA AF Korth, GE Diercks, DR Neimark, LA TI Results of examinations of pressure vessel samples and instrument nozzles from the TMI-2 lower head SO NUCLEAR ENGINEERING AND DESIGN LA English DT Article AB 15 prism-shaped steel samples were removed from the lower head of the damaged Three Mile Island Unit 2 (TMI-2) nuclear reactor pressure vessel to assess the effects of approximately 19 tonne of molten core debris that had relocated there during the 1979 loss-of-coolant accident. Metallographic examinations of the samples revealed that inside-surface temperatures of 800-1100 degrees C were attained during the accident, in an elliptical 'hot spot' with dimensions of about 1 m x 0.8 m. Tensile, creep and Charpy V-notch specimens were cut from the samples to assess the mechanical properties of the lower head material at temperatures up to the peak accident temperature. These properties were used in a margin-to-failure analysis of the lower head. Examinations of instrument nozzles removed from the lower head region assisted in defining the relocation scenario of the molten core debris and showed that the lower head was largely protected from catastrophic failure by a solidified layer below the molten core debris that acted as a partial thermal insulator. (C) 1997 Elsevier Science S.A. C1 ARGONNE NATL LAB,DIV ENERGY TECHNOL,ARGONNE,IL 60439. RP Korth, GE (reprint author), IDAHO NATL ENGN LAB,POB 1625,IDAHO FALLS,ID 83415, USA. NR 17 TC 1 Z9 1 U1 1 U2 2 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0029-5493 J9 NUCL ENG DES JI Nucl. Eng. Des. PD APR PY 1997 VL 167 IS 3 BP 267 EP 285 DI 10.1016/S0029-5493(96)01304-0 PG 19 WC Nuclear Science & Technology SC Nuclear Science & Technology GA XD222 UT WOS:A1997XD22200003 ER PT J AU Ott, LJ Hagen, S AF Ott, LJ Hagen, S TI Interpretation of the results of the CORA-33 dry core boiling water reactor test SO NUCLEAR ENGINEERING AND DESIGN LA English DT Article AB All boiling water reactor (BWR) degraded core experiments performed prior to CORA-33 were conducted under 'wet' core degradation conditions, in which water remains within the core and continuous steaming feeds metal-steam oxidation reactions on the in-core metallic surfaces. However, one dominant set of accident scenarios would occur with reduced metal oxidation under 'dry' core degradation conditions and, prior to CORA-33, this set had been neglected experimentally. The CORA-33 experiment was designed specifically to address this dominant set of BWR 'dry' core severe accident scenarios and to resolve partially phenomenological uncertainties concerning the behavior of relocating metallic melts that drain into the lower regions of a 'dry' BWR core (the ex-reactor experiments at Sandia National Laboratories will further address these uncertainties). CORA-33 was conducted on 1 October 1992, in the CORA test facility at Karlsruhe. A review of the CORA-33 data indicates that the test objectives were achieved; i.e. core degradation occurred at a core heat-up rate (characterized by the absence of any temperature escalation caused by oxidation) and a test section axial temperature profile (at incipient structural melting) that are prototypic of full-core nuclear power plant simulations under 'dry' core conditions. Simulations of the CORA-33 test at Oak Ridge National Laboratory (ORNL) have required the modification of existing control blade-canister materials interaction models to include the eutectic melting of the stainless steel-zircaloy interaction products and the heat of mixing of stainless steel and zircaloy. The timing and location of canister failure and melt intrusion into the fuel assembly appear to be adequately simulated by the ORNL models. This paper will present the results of the post-test analyses carried out at ORNL based on the experimental data and the post-test examination of the test bundle at Karlsruhe. The implications of these results with respect to degraded core modelling and the associated safety issues are also discussed. (C) 1997 Elsevier Science S.A. C1 KERNFORSCHUNGSZENTRUM KARLSRUHE GMBH,D-7500 KARLSRUHE 1,GERMANY. RP Ott, LJ (reprint author), OAK RIDGE NATL LAB,OAK RIDGE,TN 37831, USA. NR 17 TC 2 Z9 3 U1 1 U2 1 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0029-5493 J9 NUCL ENG DES JI Nucl. Eng. Des. PD APR PY 1997 VL 167 IS 3 BP 287 EP 306 DI 10.1016/S0029-5493(96)01305-2 PG 20 WC Nuclear Science & Technology SC Nuclear Science & Technology GA XD222 UT WOS:A1997XD22200004 ER PT J AU Baylor, LR Geraud, A Houlberg, WA Frigione, D Gadeberg, M Jernigan, TC DeKloe, J Kupschus, P Kuteev, BV Lang, P Oomens, AAM Qualls, AL Sato, KN Schmidt, GL AF Baylor, LR Geraud, A Houlberg, WA Frigione, D Gadeberg, M Jernigan, TC DeKloe, J Kupschus, P Kuteev, BV Lang, P Oomens, AAM Qualls, AL Sato, KN Schmidt, GL TI An international pellet ablation database SO NUCLEAR FUSION LA English DT Article ID HYDROGEN PELLET; PLASMA AB The contents are described of an international pellet ablation database (IPADBASE) that has been assembled to enable studies of pellet ablation theories that are used to describe the physics of an ablating fuel pellet in a tokamak plasma. The database represents an international effort to assemble data from several tokamaks of different magnetic configurations and auxiliary heating methods. In the initial configuration, data from JET, Tore Supra, DIII-D, FTU, TFTR, ASDEX Upgrade, JIPP T-IIU, RTP and T-10 have been included. The database contains details of measurements of deuterium and hydrogen pellet ablation, including pellet mass and speed, plasma electron density and temperature profiles, and pellet ablation light emission. A summary of the database contents and a scaling analysis of the data are presented. RP Baylor, LR (reprint author), OAK RIDGE NATL LAB,OAK RIDGE,TN 37831, USA. RI Lang, Peter/H-2507-2013; OI Lang, Peter/0000-0003-1586-8518; Baylor, Larry/0000-0002-0325-7771 NR 10 TC 53 Z9 55 U1 0 U2 9 PU INT ATOMIC ENERGY AGENCY PI VIENNA PA WAGRAMERSTRASSE 5, PO BOX 100, A-1400 VIENNA, AUSTRIA SN 0029-5515 J9 NUCL FUSION JI Nucl. Fusion PD APR PY 1997 VL 37 IS 4 BP 445 EP 450 DI 10.1088/0029-5515/37/4/I02 PG 6 WC Physics, Fluids & Plasmas SC Physics GA XP372 UT WOS:A1997XP37200002 ER PT J AU McKee, GR Fonck, RJ Stratton, BC Budny, RV Chang, Z Ramsey, AT AF McKee, GR Fonck, RJ Stratton, BC Budny, RV Chang, Z Ramsey, AT TI Transport measurements for confined non-thermal alpha particles in TFTR DT plasmas SO NUCLEAR FUSION LA English DT Article ID FUSION TEST REACTOR; FAST IONS; TOKAMAK; DEUTERIUM; TRITIUM; CHERS; SPECTROSCOPY AB Fusion produced non-thermal alpha particle radial profile measurements are obtained with the alpha-CHERS diagnostic in deuterium-tritium (DT) supershot plasmas on the Tokamak Fusion Test Reactor (TFTR). Alpha particles in the energy range 0.15 less than or equal to E-alpha less than or equal to 0.6 MeV are observed spectroscopically over a five point radial profile. The extracted non-thermal alpha signal is less than or equal to 1% of the background bremsstrahlung intensity for typical total fast alpha densities in the range (0.5-1.0) X 10(17) m(-3). The profiles obtained in two sets of discharges vary slightly, and are best described by a slowing down alpha distribution subject to neoclassical diffusion plus a small anomalous cross-field diffusion. The data are consistent with an effective anomalous diffusion coefficient in the range 0.00 less than or equal to D-alpha,D-a < 0.10 m(2)/s, where D-alpha,D-a is constant with alpha energy and with radius. C1 UNIV WISCONSIN,MADISON,WI. PRINCETON UNIV,PRINCETON PLASMA PHYS LAB,PRINCETON,NJ 08543. NR 34 TC 18 Z9 18 U1 0 U2 5 PU INT ATOMIC ENERGY AGENCY PI VIENNA PA WAGRAMERSTRASSE 5, PO BOX 100, A-1400 VIENNA, AUSTRIA SN 0029-5515 J9 NUCL FUSION JI Nucl. Fusion PD APR PY 1997 VL 37 IS 4 BP 501 EP 516 DI 10.1088/0029-5515/37/4/I08 PG 16 WC Physics, Fluids & Plasmas SC Physics GA XP372 UT WOS:A1997XP37200008 ER PT J AU Moir, RW AF Moir, RW TI Liquid first walls for magnetic fusion energy configurations SO NUCLEAR FUSION LA English DT Article ID REACTOR; BLANKET AB Liquids (similar to 7 neutron mean free paths thick), with certain restrictions, can probably be used in magnetic fusion designs between the burning plasma and the structural materials of the fusion power core. If this works there would be a number of profound advantages: a cost of electricity lower by as much as a factor of 2; removal of the need to develop new first wall materials, saving over 4 billion US dollars in development costs; a reduction of the amount and kinds of wastes generated in the plant; and the wider choice of materials permitted. The amount of material that evaporates from the liquid which can be allowed to enter the burning plasma is estimated to be less than 0.7% for lithium, 1.9% for Flibe (Li2BeF4 or LiBeF3) and 0.01% for Li17Pb83. The ability of the edge plasma to attenuate the vapour by ionization appears to exceed this requirement. This ionized vapour would be swept along open field lines into a remote burial chamber. The most practical systems would be those with topological open field lines on the outer surface, as is the case with a field reversed configuration (FRC), a spheromak, a Z pinch or a mirror machine. In a tokamak, including a spherical tokamak, the field lines outside the separatrix are restricted to a small volume inside the toroidal coil making for difficulties in introducing the liquid and removing the ionized vapour, i.e., the configuration is not open ended. RP Moir, RW (reprint author), LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550, USA. NR 16 TC 69 Z9 70 U1 0 U2 6 PU INT ATOMIC ENERGY AGENCY PI VIENNA PA WAGRAMERSTRASSE 5, PO BOX 100, A-1400 VIENNA, AUSTRIA SN 0029-5515 J9 NUCL FUSION JI Nucl. Fusion PD APR PY 1997 VL 37 IS 4 BP 557 EP 566 DI 10.1088/0029-5515/37/4/I13 PG 10 WC Physics, Fluids & Plasmas SC Physics GA XP372 UT WOS:A1997XP37200013 ER PT J AU Li, Z Li, CJ Eremin, V Verbitskaya, E AF Li, Z Li, CJ Eremin, V Verbitskaya, E TI Direct observation and measurements of neutron-induced deep levels responsible for N-eff changes in high-resistivity silicon detectors using TCT SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 1st International Conference on Radiation Effects on Semiconductor Materials, Detectors and Devices CY MAR 06-08, 1996 CL IST TECNICO GAETANO SALVEMINI, FLORENCE, ITALY HO IST TECNICO GAETANO SALVEMINI AB Neutron-irradiation-induced deep levels responsible for changes of the space charge concentration N-eff in high-resistivity silicon detectors have been revealed directly using the Transient Current Technique (TCT). It has been observed by TCT that the absolute value and sign of N-eff experience changes due to the trapping of non-equilibrium free carriers generated near the surface (about 5 mu m depth into the silicon) by short wavelength laser pulses in fully depleted detectors. Electron trapping causes N-eff to change towards negative direction (dr more acceptor-like space charges) and hole trapping causes N-eff to change towards positive direction (or more donor-like space charges). The specific temperatures associated with these N-eff changes are the freeze-out temperatures for free carrier emission from the corresponding deep levels. The carrier capture cross sections of various deep levels have been measured directly using TCT with different free carrier injection schemes. C1 AF IOFFE PHYS TECH INST, ST PETERSBURG 194021, RUSSIA. RP BROOKHAVEN NATL LAB, UPTON, NY 11973 USA. RI Verbitskaya, Elena/D-1521-2014 NR 12 TC 24 Z9 24 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 EI 1872-9576 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD APR 1 PY 1997 VL 388 IS 3 BP 297 EP 307 DI 10.1016/S0168-9002(96)01252-1 PG 11 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA XC984 UT WOS:A1997XC98400004 ER PT J AU Biggeri, U Borchi, E Bruzzi, M Lazanu, S Li, Z AF Biggeri, U Borchi, E Bruzzi, M Lazanu, S Li, Z TI CV and Hall effect analysis on neutron irradiated silicon detectors SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 1st International Conference on Radiation Effects on Semiconductor Materials, Detectors and Devices CY MAR 06-08, 1996 CL IST TECNICO GAETANO SALVEMINI, FLORENCE, ITALY HO IST TECNICO GAETANO SALVEMINI ID RESISTIVITY AB Four contact bulk samples and p(+)n junction diodes produced from high resistivity n-type silicon wafers of the same ingot have been irradiated with 1 MeV-neutron fluences between 10(12) and 3 x 10(13) cm(-2). The effective impurity concentration N-eff has been calculated from CV measurements in irradiated diodes, and bulk resistivity has been measured with the Van der Pauw method on four contact samples. The experimental resistivity and N-eff dependence on the irradiation fluence, self-annealing time and storage temperature have been modeled considering the exponential shallow donor decay and the creation of acceptor traps in the irradiated silicon. A numerical fit to the experimental data, based on the solution of the neutrality and Poisson equations, has been carried out considering an equivalent deep acceptor defect created during and after irradiation in the silicon lattice. The energy level and the introduction rate of this defect, evaluated as best-fit parameters in the numerical procedure, are E-t = 0.60-0.65 eV above the valence band edge and b similar to 0.06 cm(-1). C1 IST NAZL FIS NUCL, I-50139 FLORENCE, ITALY. INST PHYS & TECHNOL MAT, BUCHAREST, ROMANIA. BROOKHAVEN NATL LAB, UPTON, NY 11973 USA. RP UNIV FLORENCE, DIPARTIMENTO ENERGET, VIA S MARTA 3, I-50139 FLORENCE, ITALY. RI Lazanu, Sorina/B-7819-2012; Bruzzi, Mara/K-1326-2015 OI Lazanu, Sorina/0000-0003-0390-0779; Bruzzi, Mara/0000-0001-7344-8365 NR 15 TC 12 Z9 12 U1 1 U2 4 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 EI 1872-9576 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD APR 1 PY 1997 VL 388 IS 3 BP 330 EP 334 DI 10.1016/S0168-9002(97)00006-5 PG 5 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA XC984 UT WOS:A1997XC98400009 ER PT J AU Eremin, V Verbitskaya, E Li, Z Sidorov, A Fretwurst, E Lindstrom, G AF Eremin, V Verbitskaya, E Li, Z Sidorov, A Fretwurst, E Lindstrom, G TI Scanning transient current study of the I-V stabilization phenomena in silicon detectors irradiated by fast neutrons SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 1st International Conference on Radiation Effects on Semiconductor Materials, Detectors and Devices CY MAR 06-08, 1996 CL IST TECNICO GAETANO SALVEMINI, FLORENCE, ITALY HO IST TECNICO GAETANO SALVEMINI AB Investigations of the I-V stabilization phenomenon in neutron-irradiated silicon detectors have been carried out using scanning transient current technique (STCT) on non-irradiated p(+)-p-n(+) detectors, The p(+)-p-n(+) structure was used to simulate the p(+)-n-n(+) detectors irradiated beyond the space charge sign inversion (SCSI), Two mechanisms partially responsible for the I-V stabilization have been identified. C1 BROOKHAVEN NATL LAB,UPTON,NY 11973. RUSSIAN ACAD SCI,AF IOFFE PHYSICOTECH INST,ST PETERSBURG 194021,RUSSIA. RUSSIAN INST MAT SCI & TECHNOL,MOSCOW,RUSSIA. UNIV HAMBURG,INST EXPT PHYS 1,D-2000 HAMBURG,GERMANY. RI Verbitskaya, Elena/D-1521-2014 NR 4 TC 7 Z9 7 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 1 PY 1997 VL 388 IS 3 BP 350 EP 355 DI 10.1016/S0168-9002(96)01244-2 PG 6 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA XC984 UT WOS:A1997XC98400013 ER PT J AU Fretwurst, E Eremin, V Feick, H Gerhardt, J Li, Z Lindstrom, G AF Fretwurst, E Eremin, V Feick, H Gerhardt, J Li, Z Lindstrom, G TI Investigation of damage-induced defects in silicon by TCT SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 1st International Conference on Radiation Effects on Semiconductor Materials, Detectors and Devices CY MAR 06-08, 1996 CL IST TECNICO GAETANO SALVEMINI, FLORENCE, ITALY HO IST TECNICO GAETANO SALVEMINI AB Neutron- and Co-60 gamma-irradiated silicon detectors have been investigated using time-resolved current transients (TCT) induced by nanosecond laser pulses. Measurements were performed as a function of operating temperature (100-300 K) and bias voltage. Illumination was done on both the junction and ohmic side, allowing the investigation of the free charge carrier transport for electrons, respectively, holes separately. In this way, temperature-dependent trapping and detrapping effects as well as related electric field transformations have been studied and enable us to extract relevant defect parameters. Results achieved for the damaged detectors are presented and discussed in comparison with DLTS data. C1 RUSSIAN ACAD SCI,AF IOFFE PHYSICOTECH INST,ST PETERSBURG,RUSSIA. BROOKHAVEN NATL LAB,UPTON,NY 11973. RP Fretwurst, E (reprint author), UNIV HAMBURG,INST EXPT PHYS 1,D-2000 HAMBURG,GERMANY. NR 6 TC 33 Z9 33 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 1 PY 1997 VL 388 IS 3 BP 356 EP 360 DI 10.1016/S0168-9002(97)00002-8 PG 5 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA XC984 UT WOS:A1997XC98400014 ER PT J AU Husson, D Bauer, C Baumann, I Colledani, C Conway, J Delpierre, P Djama, F Dulinski, W Edwards, M Fallou, A Gan, KK Gilmore, RS Grigoriev, E Halewell, G Han, S Hessing, T Hrubec, J Kagan, H Kania, D Kass, R Knoepfle, KT Krammer, M Llewellyn, TJ Manfredi, PF Meier, D Pan, LS Pernegger, H Pernicka, M Re, V Roe, S Roff, D Rudge, A Schnetzer, S Speziall, V Stone, R Tapper, RJ Tesarek, R Trischuk, W Turchetta, R Thomson, GB Weilhammer, P Ziock, H Zoeller, M AF Husson, D Bauer, C Baumann, I Colledani, C Conway, J Delpierre, P Djama, F Dulinski, W Edwards, M Fallou, A Gan, KK Gilmore, RS Grigoriev, E Halewell, G Han, S Hessing, T Hrubec, J Kagan, H Kania, D Kass, R Knoepfle, KT Krammer, M Llewellyn, TJ Manfredi, PF Meier, D Pan, LS Pernegger, H Pernicka, M Re, V Roe, S Roff, D Rudge, A Schnetzer, S Speziall, V Stone, R Tapper, RJ Tesarek, R Trischuk, W Turchetta, R Thomson, GB Weilhammer, P Ziock, H Zoeller, M TI Neutron irradiation of CVD diamond samples for tracking detectors SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 1st International Conference on Radiation Effects on Semiconductor Materials, Detectors and Devices CY MAR 06-08, 1996 CL IST TECNICO GAETANO SALVEMINI, FLORENCE, ITALY HO IST TECNICO GAETANO SALVEMINI AB Diamond may make an excellent substrate for a tracking device in the near future, especially at colliders like LHC, where extreme running conditions are expected (high rates and high radiation levels). We report on neutron irradiation of several CVD-diamond samples at the ISIS facility (Rutherford Appleton Laboratory), which provides a fast neutron spectrum similar to that expected in a high luminosity collider experiment like CMS. We measured beam-induced currents and charge collection of diamonds exposed to fluences in excess of 10(15) n/cm(2) (peaking at 1 MeV), which should be the maximum value of the ten years total fluence at the design LHC luminosity. Physical hypotheses for the interactions of neutrons on CVD-diamond are proposed. C1 MPI HEIDELBERG,D-69029 HEIDELBERG,GERMANY. RUTGERS STATE UNIV,PISCATAWAY,NJ 08855. CCPM,F-13288 MARSEILLE,FRANCE. RUTHERFORD APPLETON LAB,OXFORD,ENGLAND. OHIO STATE UNIV,COLUMBUS,OH 43210. UNIV BRISTOL,BRISTOL BS8 1TL,AVON,ENGLAND. LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545. AUSTRIAN ACAD SCI,INST HOCHENERGIEPHYS,OAW,A-1050 VIENNA,AUSTRIA. UNIV PAVIA,DIPARTIMENTO ELECT,I-27100 PAVIA,ITALY. CERN,CH-1211 GENEVA 23,SWITZERLAND. SANDIA NATL LABS,LIVERMORE,CA 94550. UNIV TORONTO,TORONTO,ON M5S 1A7,CANADA. RP Husson, D (reprint author), CTR RECH NUCL,LEPSI,23 RUE LOESS,F-67037 STRASBOURG,FRANCE. RI Krammer, Manfred/A-6508-2010; Grigoriev, Eugene/K-6650-2013; OI Krammer, Manfred/0000-0003-2257-7751; Grigoriev, Eugene/0000-0001-7235-9715; Re, Valerio/0000-0003-0697-3420 NR 15 TC 25 Z9 26 U1 2 U2 11 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 1 PY 1997 VL 388 IS 3 BP 421 EP 426 DI 10.1016/S0168-9002(97)01248-5 PG 6 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA XC984 UT WOS:A1997XC98400027 ER PT J AU Henning, WF AF Henning, WF TI Physics with energetic radioactive ion beams SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS LA English DT Article; Proceedings Paper CT 13th International Conference on Electromagnetic Isotope Separators and Techniques Related to Their Applications (EMIS-13) CY SEP 23-27, 1996 CL BAD DURKHEIM, GERMANY SP Gesell Schwerionenforsch, Deut Forschungsgemeinsch, Int Sci Fdn, IUPAP, Land Rheinland Pfalz, Balzers Hochvakuum GMBH, Baykal Kabeltech, Bitburger Brauerei, Th Simon GMBH, Bruker Franzen Analyt GMBH, Danfys A/S, Edwards Kniese & Co Hochvakuum GMBH, HEAG Versorgungs-AG, Imbau Industriells Bauen, Jager Elektrotech GMBH, METRONOM, Gesell Ind Vermessung MBH, Noggerath Montage & Kabeltech GMBH, Pink GMBH Vakuumtech, Plein & Baus GMBH, Stadt Bad Durkheim, Stesalit AG, Struct Elektron, Sudhess Gas & Wasser AG, Deutsch Telekom, Varian GMBH, H Westphal GMBH ID F-18(P,ALPHA)O-15 REACTION; FRAGMENTATION; ISOTOPES; ENERGIES AB Beams of short-lived, unstable nuclei have opened new dimensions in studies of nuclear structure and reactions. Such beams also provide key information on reactions that take place in our sun and other stars. Status and prospects of the physics with energetic radioactive beams are summarized. RP Henning, WF (reprint author), ARGONNE NATL LAB,DIV PHYS,ARGONNE,IL 60439, USA. NR 17 TC 7 Z9 8 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-583X J9 NUCL INSTRUM METH B JI Nucl. Instrum. Methods Phys. Res. Sect. B-Beam Interact. Mater. Atoms PD APR PY 1997 VL 126 IS 1-4 BP 1 EP 6 DI 10.1016/S0168-583X(97)00999-3 PG 6 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Atomic, Molecular & Chemical; Physics, Nuclear SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA XD392 UT WOS:A1997XD39200002 ER PT J AU Carter, HK Kormicki, J Stracener, DW Breitenbach, JB Blackmon, JC Smith, MS Bardayan, DW AF Carter, HK Kormicki, J Stracener, DW Breitenbach, JB Blackmon, JC Smith, MS Bardayan, DW TI First on-line results for As and F beams from HRIBF target/ion sources SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS LA English DT Article; Proceedings Paper CT 13th International Conference on Electromagnetic Isotope Separators and Techniques Related to Their Applications (EMIS-13) CY SEP 23-27, 1996 CL BAD DURKHEIM, GERMANY SP Gesell Schwerionenforsch, Deut Forschungsgemeinsch, Int Sci Fdn, IUPAP, Land Rheinland Pfalz, Balzers Hochvakuum GMBH, Baykal Kabeltech, Bitburger Brauerei, Th Simon GMBH, Bruker Franzen Analyt GMBH, Danfys A/S, Edwards Kniese & Co Hochvakuum GMBH, HEAG Versorgungs-AG, Imbau Industriells Bauen, Jager Elektrotech GMBH, METRONOM, Gesell Ind Vermessung MBH, Noggerath Montage & Kabeltech GMBH, Pink GMBH Vakuumtech, Plein & Baus GMBH, Stadt Bad Durkheim, Stesalit AG, Struct Elektron, Sudhess Gas & Wasser AG, Deutsch Telekom, Varian GMBH, H Westphal GMBH ID ION-SOURCE; RELEASE AB The first on-line tests of the ion sources to provide radioactive ion beams of As-69.70 and F-17.18 for the Holifield Radioactive Ion Beam Facility have been performed using the UNISOR facility at KRIBF. For As-70 the measured efficiency is 0.8+/-0.3% with a hold-up time of 3.6+/-0.3 h as measured with As-72 at a target temperature of 1270 degrees C. For F-17 the efficiency for (AlF)-F-17 is 0.0024+/-0.0008% with a hold-up time of 16.4+/-0.8 m as measured with (AlF)-F-18 at a target temperature of 1470 degrees C. C1 UNIV N CAROLINA,CHAPEL HILL,NC 27599. OAK RIDGE NATL LAB,OAK RIDGE,TN 37831. YALE UNIV,AW WRIGHT NUCL STRUCT LAB,NEW HAVEN,CT 06511. VANDERBILT UNIV,DEPT PHYS,NASHVILLE,TN 37235. RP Carter, HK (reprint author), OAK RIDGE INST SCI & EDUC,OAK RIDGE,TN 37831, USA. NR 10 TC 29 Z9 29 U1 1 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-583X J9 NUCL INSTRUM METH B JI Nucl. Instrum. Methods Phys. Res. Sect. B-Beam Interact. Mater. Atoms PD APR PY 1997 VL 126 IS 1-4 BP 166 EP 169 DI 10.1016/S0168-583X(96)01087-7 PG 4 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Atomic, Molecular & Chemical; Physics, Nuclear SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA XD392 UT WOS:A1997XD39200036 ER PT J AU Bai, Y Vieira, DJ Wouters, JM Butler, GW Rosenauer, D Lobner, KEG Lind, VG Phillips, DR AF Bai, Y Vieira, DJ Wouters, JM Butler, GW Rosenauer, D Lobner, KEG Lind, VG Phillips, DR TI A high-intensity thin-target He-jet production source SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS LA English DT Article; Proceedings Paper CT 13th International Conference on Electromagnetic Isotope Separators and Techniques Related to Their Applications (EMIS-13) CY SEP 23-27, 1996 CL BAD DURKHEIM, GERMANY SP Gesell Schwerionenforsch, Deut Forschungsgemeinsch, Int Sci Fdn, IUPAP, Land Rheinland Pfalz, Balzers Hochvakuum GMBH, Baykal Kabeltech, Bitburger Brauerei, Th Simon GMBH, Bruker Franzen Analyt GMBH, Danfys A/S, Edwards Kniese & Co Hochvakuum GMBH, HEAG Versorgungs-AG, Imbau Industriells Bauen, Jager Elektrotech GMBH, METRONOM, Gesell Ind Vermessung MBH, Noggerath Montage & Kabeltech GMBH, Pink GMBH Vakuumtech, Plein & Baus GMBH, Stadt Bad Durkheim, Stesalit AG, Struct Elektron, Sudhess Gas & Wasser AG, Deutsch Telekom, Varian GMBH, H Westphal GMBH DE He-jet; gas transport; radioactive beams AB A thin-target He-jet system suited to the production and rapid transport of nonvolatile radioactive species has been successfully operated with proton beam intensities of up to 700 mu A The system consists of a water-cooled, thin-target chamber, capillary gas transport system, moving tape/Ge detection system, and an aerosol generator/gas recirculator. The yields for a wide variety of uranium fission and deep spallation products have been measured and robust operation of the system demonstrated for several weeks. He-jet transport and collection efficiencies ranged between 15 and 25% with collection rates of 10(7) to 10(8) atoms/s/isotope. The high-intensity, thin-target He-jet approach represents a robust production source for nonvolatile radioactive heavy-ion beams. C1 UTAH STATE UNIV,LOGAN,UT 84322. UNIV GIESSEN,INST PHYS 2,D-35392 GIESSEN,GERMANY. UNIV MUNICH,D-85748 GARCHING,GERMANY. RP Bai, Y (reprint author), LOS ALAMOS NATL LAB,POB 1663,LOS ALAMOS,NM 87545, USA. NR 6 TC 0 Z9 0 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-583X J9 NUCL INSTRUM METH B JI Nucl. Instrum. Methods Phys. Res. Sect. B-Beam Interact. Mater. Atoms PD APR PY 1997 VL 126 IS 1-4 BP 198 EP 200 DI 10.1016/S0168-583X(96)01074-9 PG 3 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Atomic, Molecular & Chemical; Physics, Nuclear SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA XD392 UT WOS:A1997XD39200042 ER PT J AU Zhao, XL Kilius, LR Litherland, AE Beasley, T AF Zhao, XL Kilius, LR Litherland, AE Beasley, T TI AMS measurement of environmental U-236 preliminary results and perspectives SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS LA English DT Article; Proceedings Paper CT 13th International Conference on Electromagnetic Isotope Separators and Techniques Related to Their Applications (EMIS-13) CY SEP 23-27, 1996 CL BAD DURKHEIM, GERMANY SP Gesell Schwerionenforsch, Deut Forschungsgemeinsch, Int Sci Fdn, IUPAP, Land Rheinland Pfalz, Balzers Hochvakuum GMBH, Baykal Kabeltech, Bitburger Brauerei, Th Simon GMBH, Bruker Franzen Analyt GMBH, Danfys A/S, Edwards Kniese & Co Hochvakuum GMBH, HEAG Versorgungs-AG, Imbau Industriells Bauen, Jager Elektrotech GMBH, METRONOM, Gesell Ind Vermessung MBH, Noggerath Montage & Kabeltech GMBH, Pink GMBH Vakuumtech, Plein & Baus GMBH, Stadt Bad Durkheim, Stesalit AG, Struct Elektron, Sudhess Gas & Wasser AG, Deutsch Telekom, Varian GMBH, H Westphal GMBH DE AMS; heavy element; actinide; U-236 AB U-236 is a 23.4 Ma half-life radioactive isotope whose natural global abundance is expected to be overwhelmed in many places by its production and release during nuclear power generation. The detection of excess U-236 in the environment is therefore a method of monitoring the presence of activated uranium. However, U-236 has not been widely used for environmental studies due to the difficulties of measuring it at low levels with standard cu-spectrometry or thermal ionization mass spectrometry. In principle, accelerator mass spectrometry can overcome some of the difficulties encountered in the traditional methods, making it possible to detect U-236 at very low levels so that a large range of environmental samples can be analyzed. In this paper, we report some preliminary results of the U-236 measurements of four water samples from the US Idaho Chemical Processing Plant. Limitations with our current AMS system and the perspectives for considerable improvements will be discussed. C1 US DOE,NEW YORK,NY 10014. RP Zhao, XL (reprint author), UNIV TORONTO,ISOTRACE LAB,60 ST GEORGE ST,TORONTO,ON M5S 1A7,CANADA. NR 11 TC 43 Z9 45 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-583X J9 NUCL INSTRUM METH B JI Nucl. Instrum. Methods Phys. Res. Sect. B-Beam Interact. Mater. Atoms PD APR PY 1997 VL 126 IS 1-4 BP 297 EP 300 DI 10.1016/S0168-583X(96)01034-8 PG 4 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Atomic, Molecular & Chemical; Physics, Nuclear SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA XD392 UT WOS:A1997XD39200063 ER PT J AU Guckert, R Chamberlin, EP Preston, DW Sandberg, VD Tupa, D Vieira, DJ Wollnik, H Zhao, XX AF Guckert, R Chamberlin, EP Preston, DW Sandberg, VD Tupa, D Vieira, DJ Wollnik, H Zhao, XX TI Coupling an optical trap to a mass separator SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS LA English DT Article; Proceedings Paper CT 13th International Conference on Electromagnetic Isotope Separators and Techniques Related to Their Applications (EMIS-13) CY SEP 23-27, 1996 CL BAD DURKHEIM, GERMANY SP Gesell Schwerionenforsch, Deut Forschungsgemeinsch, Int Sci Fdn, IUPAP, Land Rheinland Pfalz, Balzers Hochvakuum GMBH, Baykal Kabeltech, Bitburger Brauerei, Th Simon GMBH, Bruker Franzen Analyt GMBH, Danfys A/S, Edwards Kniese & Co Hochvakuum GMBH, HEAG Versorgungs-AG, Imbau Industriells Bauen, Jager Elektrotech GMBH, METRONOM, Gesell Ind Vermessung MBH, Noggerath Montage & Kabeltech GMBH, Pink GMBH Vakuumtech, Plein & Baus GMBH, Stadt Bad Durkheim, Stesalit AG, Struct Elektron, Sudhess Gas & Wasser AG, Deutsch Telekom, Varian GMBH, H Westphal GMBH DE mass separator; optical trap AB The efficient coupling of a magneto-optical trap to a mass separator is being developed to undertake high-precision electroweak interaction measurements in a series of radioisotopes. The use of ion implantation and subsequent heated-foil release is being pursued as a suitable way of introducing radioactive samples into the ultra-high vacuum region of an optical trap without gas loading. In this paper we discuss the layout of the mass separator, the coupling to a magneto-optical trap, and the implantation and release scheme. C1 UNIV GIESSEN KLINIKUM, INST PHYS 2, D-35392 GIESSEN, GERMANY. CALIF STATE UNIV HAYWARD, DEPT PHYS, HAYWARD, CA 94542 USA. RP Guckert, R (reprint author), LOS ALAMOS NATL LAB, POB 1663, LOS ALAMOS, NM 87545 USA. NR 4 TC 6 Z9 6 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-583X J9 NUCL INSTRUM METH B JI Nucl. Instrum. Methods Phys. Res. Sect. B-Beam Interact. Mater. Atoms PD APR PY 1997 VL 126 IS 1-4 BP 383 EP 385 DI 10.1016/S0168-583X(97)01065-3 PG 3 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Atomic, Molecular & Chemical; Physics, Nuclear SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA XD392 UT WOS:A1997XD39200079 ER PT J AU Karny, M Nitschke, JM Archambault, LF Burkard, K CanoOtt, D Hellstrom, M Huller, W Kirchner, R Lewandowski, S Roeckl, E Sulik, A AF Karny, M Nitschke, JM Archambault, LF Burkard, K CanoOtt, D Hellstrom, M Huller, W Kirchner, R Lewandowski, S Roeckl, E Sulik, A TI Coupling a total absorption spectrometer to the GSI on-line mass separator SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS LA English DT Article; Proceedings Paper CT 13th International Conference on Electromagnetic Isotope Separators and Techniques Related to Their Applications (EMIS-13) CY SEP 23-27, 1996 CL BAD DURKHEIM, GERMANY SP Gesell Schwerionenforsch, Deut Forschungsgemeinsch, Int Sci Fdn, IUPAP, Land Rheinland Pfalz, Balzers Hochvakuum GMBH, Baykal Kabeltech, Bitburger Brauerei, Th Simon GMBH, Bruker Franzen Analyt GMBH, Danfys A/S, Edwards Kniese & Co Hochvakuum GMBH, HEAG Versorgungs-AG, Imbau Industriells Bauen, Jager Elektrotech GMBH, METRONOM, Gesell Ind Vermessung MBH, Noggerath Montage & Kabeltech GMBH, Pink GMBH Vakuumtech, Plein & Baus GMBH, Stadt Bad Durkheim, Stesalit AG, Struct Elektron, Sudhess Gas & Wasser AG, Deutsch Telekom, Varian GMBH, H Westphal GMBH ID DECAY AB A total absorption spectrometer, constructed and briefly operated at the on-line isotope separator OASIS at Lawrence Berkeley Laboratory, has been moved and installed at the on-line mass separator of GSI Darmstadt. At GSI, the spectrometer has been used for beta-decay strength function measurements of nuclei in the vicinity of Sn-100 and Gd-146. C1 UNIV WARSAW,INST EXPT PHYS,WARSAW,POLAND. UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,BERKELEY,CA 94720. GESELL SCHWERIONENFORSCH MBH,D-6100 DARMSTADT,GERMANY. IFIC,INST FIS CORPUSCULAR,VALENCIA,SPAIN. NR 11 TC 57 Z9 57 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-583X J9 NUCL INSTRUM METH B JI Nucl. Instrum. Methods Phys. Res. Sect. B-Beam Interact. Mater. Atoms PD APR PY 1997 VL 126 IS 1-4 BP 411 EP 415 DI 10.1016/S0168-583X(96)01007-5 PG 5 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Atomic, Molecular & Chemical; Physics, Nuclear SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA XD392 UT WOS:A1997XD39200084 ER PT J AU Hagg, L Reinhold, CO Burgdorfer, J AF Hagg, L Reinhold, CO Burgdorfer, J TI Energy gain of highly charged ions in front of LiF SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS LA English DT Article; Proceedings Paper CT 11th International Workshop on Inelastic Ion-Surface Collisions CY SEP 22-27, 1996 CL WANGEROOGE, GERMANY SP Univ Osnabruck, Univ Oldenburg, Univ Clausthal, Humboldt Univ, Berlin, FOM Inst, Amsterdam, Max Planck Inst Plasmaphysik Garching, State Niedersachsen, Deut ForschGemeinsch ID SLOW MULTICHARGED IONS; IMAGE ACCELERATION; ELECTRON-EMISSION; LITHIUM-FLUORIDE; ABOVE-SURFACE; NEUTRALIZATION; ATOMS AB We present estimates of the energy gain of highly charged ions approaching a LiF surface, based on a modified classical-over-barrier model for insulators. The analysis includes the energy gain by image acceleration as well as the deceleration due to charge-up of the surface in a staircase sequence. The resulting velocity-dependent total energy gain is studied in detail and the results are compared with experimental data. C1 OAK RIDGE NATL LAB,OAK RIDGE,TN 37831. UNIV TENNESSEE,DEPT PHYS & ASTRON,KNOXVILLE,TN 37996. RP Hagg, L (reprint author), UNIV STOCKHOLM,FRESCATIV 24,S-10405 STOCKHOLM,SWEDEN. OI Reinhold, Carlos/0000-0003-0100-4962 NR 19 TC 7 Z9 7 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-583X J9 NUCL INSTRUM METH B JI Nucl. Instrum. Methods Phys. Res. Sect. B-Beam Interact. Mater. Atoms PD APR PY 1997 VL 125 IS 1-4 BP 133 EP 137 DI 10.1016/S0168-583X(96)00910-X PG 5 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Atomic, Molecular & Chemical; Physics, Nuclear SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA WX880 UT WOS:A1997WX88000026 ER PT J AU Meyer, FW Yan, Q vanEmmichoven, PZ Hughes, IG Spierings, G AF Meyer, FW Yan, Q vanEmmichoven, PZ Hughes, IG Spierings, G TI On the neutralization of singly and multicharged projectiles during grazing interactions with LiF(100) SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS LA English DT Article; Proceedings Paper CT 11th International Workshop on Inelastic Ion-Surface Collisions CY SEP 22-27, 1996 CL WANGEROOGE, GERMANY SP Univ Osnabruck, Univ Oldenburg, Univ Clausthal, Humboldt Univ, Berlin, FOM Inst, Amsterdam, Max Planck Inst Plasmaphysik Garching, State Niedersachsen, Deut ForschGemeinsch DE electron transfer; alkali halides; image acceleration; multicharged ion ID SURFACE; IONS; SCATTERING; ATOMS; FRONT AB Measurements are reported of scattered neutral fractions for Na, K, Cs and Ne singly and multicharged ions, and of scattered negative ion fractions for incident O, F and B projectiles grazingly incident on LiF(100) as function of projectile velocity. In the case of the Na and Ne incident ions, significant dependence of the scattered neutral fractions on incident charge state is found, which is most pronounced at the lowest investigated velocities. Possible reasons for the observed initial charge state dependence are considered. In addition, results are reported for the target azimuthal dependence of the final neutral fraction observed for grazingly incident 35 keV Cs7+ ions. C1 UNIV UTRECHT,DEBYE INST,NL-3584 CC UTRECHT,NETHERLANDS. QUEENS UNIV BELFAST,DEPT PURE & APPL PHYS,BELFAST BT7 1NN,ANTRIM,NORTH IRELAND. RP Meyer, FW (reprint author), OAK RIDGE NATL LAB,OAK RIDGE,TN 37831, USA. RI Institute (DINS), Debye/G-7730-2014 NR 24 TC 46 Z9 48 U1 0 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-583X J9 NUCL INSTRUM METH B JI Nucl. Instrum. Methods Phys. Res. Sect. B-Beam Interact. Mater. Atoms PD APR PY 1997 VL 125 IS 1-4 BP 138 EP 145 DI 10.1016/S0168-583X(96)00798-7 PG 8 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Atomic, Molecular & Chemical; Physics, Nuclear SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA WX880 UT WOS:A1997WX88000027 ER PT J AU Schenkel, T Barnes, AV Briere, MA Hamza, A vonWittenau, AS Schneider, DH AF Schenkel, T Barnes, AV Briere, MA Hamza, A vonWittenau, AS Schneider, DH TI Emission of secondary particles from metals and insulators at impact of slow highly charged ions SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS LA English DT Article; Proceedings Paper CT 11th International Workshop on Inelastic Ion-Surface Collisions CY SEP 22-27, 1996 CL WANGEROOGE, GERMANY SP Univ Osnabruck, Univ Oldenburg, Univ Clausthal, Humboldt Univ, Berlin, FOM Inst, Amsterdam, Max Planck Inst Plasmaphysik Garching, State Niedersachsen, Deut ForschGemeinsch ID ELECTRON-EMISSION; INDUCED DESORPTION; SURFACE; SIO2; ACCELERATION; BOMBARDMENT; DEPENDENCE; YIELDS; TRACKS; MODEL AB The emission of secondary electrons and ions from clean Au, CxHy-Au and SiO2 surfaces at impact of slow (upsilon approximate to 0.3 upsilon(Bohr)) ions has been measured as a function of incident ion charge for 1 + less than or equal to q less than or equal to 75 +. Electron yields from thermal silicon dioxide films (150 nm on Si) are found to be lower than those from Au and CxHy-Au for q > 3 +. Yields of negative secondary ions from SiO2 and CxHy-Au were recorded in parallel with electron emission data and exhibit a q(n), n approximate to 4, dependency on incident ion charge. A direct comparison of collisional and electronic contributions to secondary ion production from SiO2 films using a beam of charge state equilibrated Xe-q=qeq (at 2.75 keV/u) shows positive and negative secondary ion yield increases with incident ion charge of > 400. Results are discussed in relation to key signatures of electronic sputtering by Coulomb explosions. C1 UNIV FRANKFURT,INST KERNPHYS,D-60486 FRANKFURT,GERMANY. RP Schenkel, T (reprint author), LAWRENCE LIVERMORE NATL LAB,PHYS & SPACE TECHNOL DIRECTORATE,LIVERMORE,CA 94550, USA. NR 40 TC 44 Z9 44 U1 1 U2 5 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-583X J9 NUCL INSTRUM METH B JI Nucl. Instrum. Methods Phys. Res. Sect. B-Beam Interact. Mater. Atoms PD APR PY 1997 VL 125 IS 1-4 BP 153 EP 158 DI 10.1016/S0168-583X(96)00930-5 PG 6 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Atomic, Molecular & Chemical; Physics, Nuclear SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA WX880 UT WOS:A1997WX88000029 ER PT J AU Yarmoff, JA Weare, CB AF Yarmoff, JA Weare, CB TI Resonant charge transfer during scattering of low energy Li-7(+) from cesiated surfaces SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS LA English DT Article; Proceedings Paper CT 11th International Workshop on Inelastic Ion-Surface Collisions CY SEP 22-27, 1996 CL WANGEROOGE, GERMANY SP Univ Osnabruck, Univ Oldenburg, Univ Clausthal, Humboldt Univ, Berlin, FOM Inst, Amsterdam, Max Planck Inst Plasmaphysik Garching, State Niedersachsen, Deut ForschGemeinsch ID COVERED AL(100); ION-SCATTERING; NEUTRALIZATION; ADSORPTION; COLLISIONS; SI(111)7X7; EXCHANGE; PROBE; CS AB Neutral fractions of 2 keV Li-7(+) ions scattered from cesiated Al(100), Ni(100) and Si(111)-7 x 7 surfaces are measured and compared. For low coverages of Cs adsorbed on Al(100) and Ni(100), there are large differences between the neutral fractions of Li ions singly scattered from substrate and adsorbate atomic sites. These differences disappear as the Cs coverage is increased. This behavior is attributed to an inhomogeneous to homogeneous transition in the surface local electrostatic potential. For Cs adsorbed on Si(111)-7 x 7, on the other hand, the Li neutral fractions for scattering from Si and Cs sites are nearly equal over the entire coverage range. This is attributed to coupling of the exiting Li energy levels to the surface dangling bonds. As a result, the final charge state distribution is insensitive to adsorbate-induced inhomogeneities in the surface potential. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV MAT SCI,BERKELEY,CA 94720. RP Yarmoff, JA (reprint author), UNIV CALIF RIVERSIDE,DEPT PHYS,RIVERSIDE,CA 92521, USA. NR 20 TC 18 Z9 18 U1 1 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-583X J9 NUCL INSTRUM METH B JI Nucl. Instrum. Methods Phys. Res. Sect. B-Beam Interact. Mater. Atoms PD APR PY 1997 VL 125 IS 1-4 BP 262 EP 267 DI 10.1016/S0168-583X(96)00895-6 PG 6 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Atomic, Molecular & Chemical; Physics, Nuclear SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA WX880 UT WOS:A1997WX88000046 ER PT J AU Anderson, TS Magruder, RH Kinser, DL Zuhr, RA Thomas, DK AF Anderson, TS Magruder, RH Kinser, DL Zuhr, RA Thomas, DK TI Formation and optical properties of metal nanoclusters formed by sequential implantation of Cd and Ag in silica SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS LA English DT Article ID NONLINEAR OPTICS; GLASS; RESONANCE; COLLOIDS AB Nanometer dimension metal colloids fabricated by sequential implantation of Cd then Ag in silica and by single element implantations of the same elements are characterized by transmission electron microscopy and optical spectroscopy, A nominal dose of 6 x 10(16) ions/cm(2) as determined by current integration was used far both ions species. The doses used for the sequential implantations were a 1 to 1 ratio of Cd to Ag. Sequential implantation of Cd and Ag leads to the formation of multi-component metal nanoclusters and elemental. nanoclusters, The electron diffraction measurements were consistent with the formation of Ag5Cd8 and elemental Ag. With annealing the composition of the nanoclusters shifts to AgCd and elemental Cd, The optical responses are consistent with results expected from effective medium theory. C1 OAK RIDGE NATL LAB,DIV SOLID STATE,OAK RIDGE,TN 37831. RP Anderson, TS (reprint author), VANDERBILT UNIV,DEPT APPL ENGN & SCI,NASHVILLE,TN 37235, USA. NR 20 TC 22 Z9 22 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-583X J9 NUCL INSTRUM METH B JI Nucl. Instrum. Methods Phys. Res. Sect. B-Beam Interact. Mater. Atoms PD APR PY 1997 VL 124 IS 1 BP 40 EP 46 DI 10.1016/S0168-583X(96)00923-8 PG 7 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Atomic, Molecular & Chemical; Physics, Nuclear SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA WU926 UT WOS:A1997WU92600006 ER PT J AU Krause, HF Deveney, EF Jones, NL Vane, CR Datz, S Knudsen, H Grafstrom, P Schuch, R AF Krause, HF Deveney, EF Jones, NL Vane, CR Datz, S Knudsen, H Grafstrom, P Schuch, R TI Novel apparatus and methods for performing remotely controlled particle-solid interaction experiments at CERN SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS LA English DT Article ID POSITRON PAIR PRODUCTION; HEAVY-ION COLLISIONS; ELECTROMAGNETIC-FIELDS; FIXED TARGETS; SULFUR IONS AB Recent atomic physics studies involving ultrarelativistic Ph ions required solid target positioners, scintillators, and a sophisticated data acquisition and control system placed in a remote location at the CERN Super Proton Synchrotron near Geneva, Switzerland. The apparatus, installed in a high-radiation zone underground, had to (i) function for months, (ii) automatically respond to failures such as power outages and particle-induced computer upsets, and (iii) communicate with the outside world via a telephone line, The heart of the apparatus developed was an Apple Macintosh-based CAMAC system that answered the telephone and interpreted and executed remote control commands that (i) sensed and set targets, (ii) controlled voltages and discriminator levels for scintillators, (iii) modified data acquisition hardware logic, (iv) reported control information, and (v) automatically synchronized data acquisition to the CERN spill cycle via a modem signal and transmitted experimental data to a remote computer. No problems were experienced using intercontinental telephone connections at 1200 baud. Our successful ''virtual laboratory'' approach that uses off-the-shelf electronics is generally adaptable to more conventional bench-type experiments. C1 AARHUS UNIV,INST PHYS,DK-8000 AARHUS C,DENMARK. CERN,CH-1211 GENEVA 23,SWITZERLAND. UNIV STOCKHOLM,MANNE SIEGBAHN LAB,STOCKHOLM,SWEDEN. RP Krause, HF (reprint author), OAK RIDGE NATL LAB,DIV PHYS,POB 2008,OAK RIDGE,TN 37831, USA. NR 22 TC 3 Z9 3 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-583X J9 NUCL INSTRUM METH B JI Nucl. Instrum. Methods Phys. Res. Sect. B-Beam Interact. Mater. Atoms PD APR PY 1997 VL 124 IS 1 BP 128 EP 139 DI 10.1016/S0168-583X(97)00098-0 PG 12 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Atomic, Molecular & Chemical; Physics, Nuclear SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA WU926 UT WOS:A1997WU92600019 ER PT J AU Burgdorfer, J AF Burgdorfer, J TI On the utility of atomic collision physics SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS LA English DT Article; Proceedings Paper CT Proceedings of the 6th Workshop on Fast Ion-Atom Collision Processes CY SEP 09-13, 1996 CL DEBRECEN, HUNGARY ID POSITRON PAIR PRODUCTION; HEAVY-ION COLLISIONS; DOUBLE-IONIZATION; ELECTRON-CAPTURE; RYDBERG ATOMS; EXCITATION-IONIZATION; COMPTON-SCATTERING; HELIUM; ANTIPROTONS; PHOTOABSORPTION AB Atomic collision physics represents a mature field with sophisticated experimental and theoretical tools at our disposal. Yet, atomic collisions have remained at the forefront of research because of the unique capability to contribute to fundamental physics such as the many-body problem and the far-reaching utility in many fields of science. This keynote address will try to highlight the significance of atomic collisions in challenges at the forefront of current research ranging from ultracold atomic collisions and its applications to Bose-Einstein condensation, ultrarelativistic collisions and collisions between particles and antiparticles to collisions with microcapillaries. C1 OAK RIDGE NATL LAB,OAK RIDGE,TN 37831. RP Burgdorfer, J (reprint author), UNIV TENNESSEE,DEPT PHYS,KNOXVILLE,TN 37996, USA. NR 41 TC 1 Z9 1 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-583X J9 NUCL INSTRUM METH B JI Nucl. Instrum. Methods Phys. Res. Sect. B-Beam Interact. Mater. Atoms PD APR PY 1997 VL 124 IS 2-3 BP 151 EP 159 DI 10.1016/S0168-583X(96)00813-0 PG 9 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Atomic, Molecular & Chemical; Physics, Nuclear SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA WU535 UT WOS:A1997WU53500002 ER PT J AU Datz, S Krause, HF Vane, CR Dittner, PF Deveney, EF Knudsen, H Grafstrom, P Schuch, R Gao, H Hutton, R AF Datz, S Krause, HF Vane, CR Dittner, PF Deveney, EF Knudsen, H Grafstrom, P Schuch, R Gao, H Hutton, R TI Atomic collisions at ultrarelativistic energies: 6.4 TeV S and 33.2 TeV Pb SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS LA English DT Article; Proceedings Paper CT Proceedings of the 6th Workshop on Fast Ion-Atom Collision Processes CY SEP 09-13, 1996 CL DEBRECEN, HUNGARY ID POSITRON PAIR PRODUCTION; HEAVY-ION COLLISIONS; COULOMB COLLISIONS; DILEPTON EMISSION; CROSS-SECTION; SULFUR IONS; ELECTRON; FIELDS AB We have used beams of 6.4 TeV S ions and 33.2 TeV Pb ions obtained from the CERN-SPS facility to study collision processes of heavy ions at ultrarelativistic energies. Measurements have been made of electron-positron pair production, and capture of an electron produced from the negative continuum onto bound states of the moving ion. Here we report on some aspects of these results. In a new formulation for the theory of electronic stopping power of ions at ultrarelativistic energies/Lindhard and Sorensen (LS) find that nuclear size effects should act to reduce the momentum transfer to electrons and hence the stopping power. Using the 33.2-Pb ions, we measured d E/d x in C, Si, Cu, Sn and Pb targets. The LS theory was confirmed. C1 CERN,CH-1211 GENEVA 23,SWITZERLAND. UNIV STOCKHOLM,MANNE SIEGBAHN LAB,S-10405 STOCKHOLM,SWEDEN. LUND UNIV,S-22362 LUND,SWEDEN. AARHUS UNIV,INST PHYS,DK-8000 AARHUS C,DENMARK. RP Datz, S (reprint author), OAK RIDGE NATL LAB,DIV PHYS,OAK RIDGE,TN 37831, USA. NR 25 TC 1 Z9 1 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-583X J9 NUCL INSTRUM METH B JI Nucl. Instrum. Methods Phys. Res. Sect. B-Beam Interact. Mater. Atoms PD APR PY 1997 VL 124 IS 2-3 BP 169 EP 176 DI 10.1016/S0168-583X(96)00817-8 PG 8 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Atomic, Molecular & Chemical; Physics, Nuclear SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA WU535 UT WOS:A1997WU53500004 ER PT J AU Macek, JH AF Macek, JH TI Top-of-barrier electrons SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS LA English DT Article; Proceedings Paper CT Proceedings of the 6th Workshop on Fast Ion-Atom Collision Processes CY SEP 09-13, 1996 CL DEBRECEN, HUNGARY ID SADDLE-POINT ELECTRONS; IMPULSE APPROXIMATION; IONIZING COLLISIONS; IONIZATION; MECHANISM; HYDROGEN; ATOMS; IONS AB The energy and angular distribution of electrons ejected from one-electron species by fast ion impact show two noticable features, namely, the binary encounter ridge and the continuum capture cusp. No other features have been conclusively identified although there has been some contradictory evidence for a third feature, namely, saddle point or top-of-barrier electrons. For electrons ejected from atoms by ions with velocities below the mean electron velocity in the initial state, both the binary encounter ridge and the continuum capture cusp are suppressed. In this region the top-of-barrier mechanism is predicted to contribute strongly to ionization. Theoretical and experimental evidence for the associated top-of-barrier electrons is reviewed. C1 OAK RIDGE NATL LAB,OAK RIDGE,TN 37831. RP Macek, JH (reprint author), UNIV TENNESSEE,DEPT PHYS & ASTRON,KNOXVILLE,TN 37996, USA. NR 33 TC 6 Z9 6 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-583X J9 NUCL INSTRUM METH B JI Nucl. Instrum. Methods Phys. Res. Sect. B-Beam Interact. Mater. Atoms PD APR PY 1997 VL 124 IS 2-3 BP 191 EP 197 DI 10.1016/S0168-583X(96)01053-1 PG 7 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Atomic, Molecular & Chemical; Physics, Nuclear SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA WU535 UT WOS:A1997WU53500007 ER PT J AU Dorner, R Mergel, V Spielberger, L Achler, M Khayyat, K Vogt, T Brauning, H Jagutzki, O Weber, T Ullrich, J Moshammer, R Unverzagt, M Schmitt, W Khemliche, H Prior, MH Cocke, CL Feagin, J Olson, RE SchmidtBocking, H AF Dorner, R Mergel, V Spielberger, L Achler, M Khayyat, K Vogt, T Brauning, H Jagutzki, O Weber, T Ullrich, J Moshammer, R Unverzagt, M Schmitt, W Khemliche, H Prior, MH Cocke, CL Feagin, J Olson, RE SchmidtBocking, H TI Kinematically complete experiments using cold target recoil ion momentum spectroscopy SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS LA English DT Article; Proceedings Paper CT Proceedings of the 6th Workshop on Fast Ion-Atom Collision Processes CY SEP 09-13, 1996 CL DEBRECEN, HUNGARY ID RESOLVED DOUBLE PHOTOIONIZATION; ELECTRON-ELECTRON; SINGLE IONIZATION; NEAR-THRESHOLD; CROSS-SECTION; HE SINGLE; HELIUM; ENERGY; COLLISIONS; DISTRIBUTIONS AB Cold Target Recoil Ion Momentum Spectroscopy allows the detection of the three-dimensional momentum vector of the recoiling product ion from ion, electron or photon atom collisions with 4 pi solid angle and high resolution. It can be combined with large area position-sensitive detectors for electron detection or measurement of the projectile charge-state and scattering angle. Such 'reaction microscopes' cover the full correlated momentum space of all fragments of an atomic reaction yielding kinematically complete information for each reaction event. For the first time in atomic collision physics fully differential data became available in the sense that not only the momenta of all fragments, but also the complete momentum space is observed in one experiment. Recent results achieved with this new technique for slow p-He collisions and threshold photo ionization of He will be discussed. C1 GESELL SCHWERIONENFORSCH MBH,D-64291 DARMSTADT,GERMANY. LBNL,BERKELEY,CA 94720. KANSAS STATE UNIV,DEPT PHYS,MANHATTAN,KS 66506. CALIF STATE UNIV FULLERTON,DEPT PHYS,FULLERTON,CA 92634. UNIV MISSOURI,DEPT PHYS,ROLLA,MO 65401. RP Dorner, R (reprint author), UNIV FRANKFURT,INST KERNPHYS,AUGUST EULER STR 6,D-60486 FRANKFURT,GERMANY. RI Doerner, Reinhard/A-5340-2008; Weber, Thorsten/K-2586-2013 OI Doerner, Reinhard/0000-0002-3728-4268; Weber, Thorsten/0000-0003-3756-2704 NR 37 TC 36 Z9 36 U1 0 U2 5 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-583X J9 NUCL INSTRUM METH B JI Nucl. Instrum. Methods Phys. Res. Sect. B-Beam Interact. Mater. Atoms PD APR PY 1997 VL 124 IS 2-3 BP 225 EP 231 DI 10.1016/S0168-583X(96)00877-4 PG 7 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Atomic, Molecular & Chemical; Physics, Nuclear SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA WU535 UT WOS:A1997WU53500012 ER PT J AU Prior, MH Khemliche, H AF Prior, MH Khemliche, H TI Auger anisotropy: A probe of doubly excited product states SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS LA English DT Article; Proceedings Paper CT Proceedings of the 6th Workshop on Fast Ion-Atom Collision Processes CY SEP 09-13, 1996 CL DEBRECEN, HUNGARY ID DOUBLE-ELECTRON-CAPTURE; AUTOIONIZATION ELECTRONS; COLLISIONS AB Energy and spatial distributions of Auger electrons emitted from products of ion/atom collisions can reveal the identity and character of states created by excitation, inner shell ionization or multi-electron transfer. When coupled with coincident detection of projectile scattering, one can obtain a near ''complete'' experiment, i.e. the scattering angle dependence of complex magnetic substate amplitudes. Such results challenge theory at the finest level of detail. This report summarizes progress made in the study of double electron capture in measurements of this kind. RP Prior, MH (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,1 CYCLOTRON RD,BERKELEY,CA 94720, USA. NR 11 TC 0 Z9 0 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-583X J9 NUCL INSTRUM METH B JI Nucl. Instrum. Methods Phys. Res. Sect. B-Beam Interact. Mater. Atoms PD APR PY 1997 VL 124 IS 2-3 BP 243 EP 248 DI 10.1016/S0168-583X(96)01044-0 PG 6 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Atomic, Molecular & Chemical; Physics, Nuclear SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA WU535 UT WOS:A1997WU53500014 ER PT J AU Reinhold, CO Burgdorfer, J Minniti, R Elston, SB AF Reinhold, CO Burgdorfer, J Minniti, R Elston, SB TI Solid-state effects in electron emission from atomic collisions near surfaces SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS LA English DT Article; Proceedings Paper CT Proceedings of the 6th Workshop on Fast Ion-Atom Collision Processes CY SEP 09-13, 1996 CL DEBRECEN, HUNGARY ID GLANCING-ANGLE SCATTERING; FAST HEAVY-IONS; MEV LIGHT-IONS; CONVOY ELECTRONS; CHARGE-TRANSFER; CROSS-SECTIONS; GRAZING-ANGLE; ACCELERATION; HE; IONIZATION AB We present a brief progress report of recent studies of the ejected electron spectra arising from glancing-angle ion-surface scattering involving collision energies of hundreds of keV/u. A broad range of electron energies and emission angles is analyzed containing prominent structures such as the convoy electron peak and the binary ridge. Particular emphasis is placed on the search for signatures of dynamic image interactions and multiple scattering near surfaces. C1 UNIV TENNESSEE,KNOXVILLE,TN 37996. RP Reinhold, CO (reprint author), OAK RIDGE NATL LAB,DIV PHYS,OAK RIDGE,TN 37831, USA. OI Reinhold, Carlos/0000-0003-0100-4962 NR 41 TC 0 Z9 0 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-583X J9 NUCL INSTRUM METH B JI Nucl. Instrum. Methods Phys. Res. Sect. B-Beam Interact. Mater. Atoms PD APR PY 1997 VL 124 IS 2-3 BP 320 EP 326 DI 10.1016/S0168-583X(96)00816-6 PG 7 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Atomic, Molecular & Chemical; Physics, Nuclear SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA WU535 UT WOS:A1997WU53500024 ER PT J AU Zalutsky, MR Stabin, MG Larsen, RH Bigner, DD AF Zalutsky, MR Stabin, MG Larsen, RH Bigner, DD TI Tissue distribution and radiation dosimetry of astatine-211-labeled chimeric 81C6, an alpha-particle-emitting immunoconjugate SO NUCLEAR MEDICINE AND BIOLOGY LA English DT Article DE astatine-211; radioimmunotherapy; dosimetry; monoclonal antibody ID NEOPLASTIC MENINGITIS; MONOCLONAL-ANTIBODY; CEREBROSPINAL-FLUID; IN-VIVO; RADIOIMMUNOTHERAPY; TENASCIN; F(AB')2; BRAIN; IMMUNOREACTIVITY; IRRADIATION AB A paired-label study was performed in athymic mice bearing subcutaneous D-54 MG human glioma xenografts to compare the localization of human/mouse anti-tenascin chimeric antibody 81C6 labeled by reaction with N-succinimidyl 3-[At-211]astatobenzoate and N-succinimidyl 3-[I-131]iodobenzoate. Over the 48-h observation period, the distribution of At-211- and I-131-labeled antibody were quite similar in tumor and normal tissues except stomach. These data were used to calculate human radiation doses for both intravenously and intrathecal administered At-211-labeled chimeric 81C6 using a quality factor of 5 for alpha-emissions. (C) 1997 Elsevier Science Inc. C1 DUKE UNIV,MED CTR,DEPT PATHOL,DURHAM,NC 27710. OAK RIDGE SCI & EDUC,DIV MED SCI,OAK RIDGE,TN 37831. RP Zalutsky, MR (reprint author), DUKE UNIV,MED CTR,DEPT RADIOL,DURHAM,NC 27710, USA. FU NCI NIH HHS [CA 42324]; NINDS NIH HHS [NS 20023] NR 49 TC 35 Z9 37 U1 3 U2 11 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0883-2897 J9 NUCL MED BIOL JI Nucl. Med. Biol. PD APR PY 1997 VL 24 IS 3 BP 255 EP 261 DI 10.1016/S0969-8051(97)00060-7 PG 7 WC Radiology, Nuclear Medicine & Medical Imaging SC Radiology, Nuclear Medicine & Medical Imaging GA XE323 UT WOS:A1997XE32300007 PM 9228660 ER PT J AU Vogt, R AF Vogt, R TI Charmed hadron asymmetries from intrinsic charm SO NUCLEAR PHYSICS B LA English DT Article; Proceedings Paper CT 2nd International Conference on Hyperons, Charm and Beauty Hadrons CY AUG 27-30, 1996 CL MONTREAL, CANADA SP Inst Particle Phys, Canada, Int Sci Fdn, Minist Ind Sci & Technol, Quebec, Concordia Univ ID HEAVY-QUARK PRODUCTION; LUND MONTE-CARLO; PARTON DISTRIBUTIONS; CROSS-SECTION; EMULSION INTERACTIONS; NUCLEON-INTERACTIONS; JET FRAGMENTATION; MESON PRODUCTION; QCD CORRECTIONS; E+E-PHYSICS AB We discuss charm production anomalies at large x(F) in the context of the intrinsic charm model. In particular, we focus on recent data on charm meson and baryon asymmetries. C1 UNIV CALIF DAVIS, DEPT PHYS, DAVIS, CA USA. RP UNIV CALIF BERKELEY, LAWRENCE BERKELEY LAB, DIV NUCL SCI, 1 CYCLOTRON RD, BERKELEY, CA 94720 USA. NR 57 TC 1 Z9 1 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0550-3213 EI 1873-1562 J9 NUCL PHYS B JI Nucl. Phys. B PD APR PY 1997 SU 55A BP 135 EP 142 DI 10.1016/S0920-5632(97)00165-5 PG 8 WC Physics, Particles & Fields SC Physics GA XA934 UT WOS:A1997XA93400026 ER PT J AU Dunietz, I Incandela, J Snider, FD AF Dunietz, I Incandela, J Snider, FD TI Puzzles in heavy flavor physics SO NUCLEAR PHYSICS B LA English DT Article; Proceedings Paper CT 2nd International Conference on Hyperons, Charm and Beauty Hadrons CY AUG 27-30, 1996 CL MONTREAL, CANADA SP Inst Particle Phys, Canada, Int Sci Fdn, Minist Ind Sci & Technol, Quebec, Concordia Univ AB We show that there exists a discrepancy in two complementary determinations of B((B) over bar --> DX). Either inclusive B decays are not understood or B(D-0 --> K(-)pi(+)) has to be reduced from currently accepted values. Since B(D-0 --> K(-)pi(+)) calibrates most charmed hadron yields, a reduced value affects some measurements of R-c. We then examine the charm background in measurements of R-b and suggest how systematic errors in the charm decay multiplicity might resolve the discrepancy in R-b. C1 JOHNS HOPKINS UNIV,BALTIMORE,MD 21218. RP Dunietz, I (reprint author), FERMILAB NATL ACCELERATOR LAB,POB 500,BATAVIA,IL 60510, USA. NR 15 TC 3 Z9 3 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 PY 1997 SU 55A BP 145 EP 148 DI 10.1016/S0920-5632(97)00166-7 PG 4 WC Physics, Particles & Fields SC Physics GA XA934 UT WOS:A1997XA93400027 ER PT J AU Ramberg, EJ AF Ramberg, EJ TI Charm baryon and hyperon physics at Fermilab's SELEX spectrometer SO NUCLEAR PHYSICS B LA English DT Article; Proceedings Paper CT 2nd International Conference on Hyperons, Charm and Beauty Hadrons CY AUG 27-30, 1996 CL MONTREAL, CANADA SP Inst Particle Phys, Canada, Int Sci Fdn, Minist Ind Sci & Technol, Quebec, Concordia Univ AB Fermilab experiment 181, or SELEX, is starting to take data, with the goal of observing on the order of 1 million reconstructed charm decays. A variety of targets and beams will yield significant new information on charm production. The detector has good efficiency in the forward direction, which will enhance the yield of charm baryon decays. Several topics in hyperon physics can be addressed as well with this spectrometer. RP Ramberg, EJ (reprint author), FERMILAB NATL ACCELERATOR LAB,POB 500,BATAVIA,IL 60510, USA. NR 9 TC 4 Z9 4 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 PY 1997 SU 55A BP 173 EP 175 DI 10.1016/S0920-5632(97)00170-9 PG 3 WC Physics, Particles & Fields SC Physics GA XA934 UT WOS:A1997XA93400031 ER PT J AU Butler, JN AF Butler, JN TI BTEV - A Dedicated B Physics detector at the Fermilab Tevatron Collider SO NUCLEAR PHYSICS B LA English DT Article; Proceedings Paper CT 2nd International Conference on Hyperons, Charm and Beauty Hadrons CY AUG 27-30, 1996 CL MONTREAL, CANADA SP Inst Particle Phys, Canada, Int Sci Fdn, Minist Ind Sci & Technol, Quebec, Concordia Univ AB The capabilities of future Dedicated Hadron Collider B Physics experiments are discussed and compared to experiments that will run in the next few years. The design for such an experiment at the Tevatron Collider is presented and an evolutionary path for developing it is outlined. RP Butler, JN (reprint author), FERMILAB NATL ACCELERATOR LAB,POB 500,BATAVIA,IL 60510, USA. NR 8 TC 0 Z9 0 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0550-3213 J9 NUCL PHYS B JI Nucl. Phys. B PD APR PY 1997 SU 55A BP 251 EP 259 DI 10.1016/S0920-5632(97)00183-7 PG 9 WC Physics, Particles & Fields SC Physics GA XA934 UT WOS:A1997XA93400044 ER PT J AU Dubois, R AF Dubois, R TI Measurements of A(b), R-b and the B-+/-,B-0 lifetimes at the Z(0) resonance by SLD SO NUCLEAR PHYSICS B LA English DT Article; Proceedings Paper CT 2nd International Conference on Hyperons, Charm and Beauty Hadrons CY AUG 27-30, 1996 CL MONTREAL, CANADA SP Inst Particle Phys, Canada, Int Sci Fdn, Minist Ind Sci & Technol, Quebec, Concordia Univ ID FORWARD-BACKWARD ASYMMETRY; LUND MONTE-CARLO; JET FRAGMENTATION; E+E-PHYSICS; Z-DECAYS; LEPTONS AB R-b, A(b) and the lifetimes of the B+ (B-u) and B-0 (B-d) mesons have been measured using a sample of 150,000 hadronic Z(0) decays collected by the SLD experiment at the SLC between 1993 and 1995. The analyses make use of a novel topological vertexing technique to obtain charge, decay length and vertex mass. The asymmetry A(b) is measured with a self-calibrating technique employing momentum-weighted track charge from both hemispheres in the tagged events as well as by using the polar angle dependency of the Z(0)-pole polarized cross section and tagging the bottom and charmed hadrons in the semileptonic decay channel. RP Dubois, R (reprint author), STANFORD UNIV,STANFORD LINEAR ACCELERATOR CTR,STANFORD,CA 94309, USA. NR 18 TC 0 Z9 0 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0550-3213 J9 NUCL PHYS B JI Nucl. Phys. B PD APR PY 1997 SU 55A BP 302 EP 309 PG 8 WC Physics, Particles & Fields SC Physics GA XA934 UT WOS:A1997XA93400052 ER PT J AU Mattison, TS AF Mattison, TS TI The PEP-II collider and commissioning detectors SO NUCLEAR PHYSICS B LA English DT Article; Proceedings Paper CT 2nd International Conference on Hyperons, Charm and Beauty Hadrons CY AUG 27-30, 1996 CL MONTREAL, CANADA SP Inst Particle Phys, Canada, Int Sci Fdn, Minist Ind Sci & Technol, Quebec, Concordia Univ AB PEP-II will collide 9 GeV e(-) with 3.1 GeV e(+) at high luminosity on the Upsilon(4S) resonance to produce B-meson pairs for study of CP-violation. Progress on its design and construction at SLAG is reported. Since PEP-II has a complicated interaction region and high beam currents, and will be completed before the new BABAR detector is available, a set of smaller detectors will be used to measure the beam-induced backgrounds during PEP-II commissioning. RP Mattison, TS (reprint author), STANFORD UNIV,STANFORD LINEAR ACCELERATOR CTR,STANFORD,CA 94309, USA. NR 5 TC 0 Z9 0 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0550-3213 J9 NUCL PHYS B JI Nucl. Phys. B PD APR PY 1997 SU 55A BP 310 EP 314 DI 10.1016/S0920-5632(97)00192-8 PG 5 WC Physics, Particles & Fields SC Physics GA XA934 UT WOS:A1997XA93400053 ER PT J AU Cooney, MG Miller, JH AF Cooney, MG Miller, JH TI Calculated distortions of duplex DNA by a cis, syn cyclobutane thymine dimer are unaffected by a 3' TpA step SO NUCLEIC ACIDS RESEARCH LA English DT Article ID PARTICLE MESH EWALD; MOLECULAR-DYNAMICS; B-DNA; CYANOETHYL ESTER; PHOTODIMER; H-1-NMR; D(GCGTTGCG).D(CGCAACGC); MUTAGENESIS; FLEXIBILITY; SEQUENCES AB Molecular dynamics simulations were performed on the duplex DNA dodecamers d(CGCGAATTCGCG): d(CGCGAATTCGCG) and d(GCACGAATTAAG): d(CTTAATTCGTGC), where TT denotes a cis, syn cyclobutane thymine dimer, The constant temperature and pressure algorithm of the AMBER 4.1 molecular-modeling package was used with explicit water and counterions, periodic boundary conditions and electrostatic interactions evaluated by the particle-mesh Ewald method, Results were analyzed by the CURVES algorithm and its implementation in DIALS and WINDOWS, Calculated distortions of DNA structure by the thymine dimer were qualitatively and quantitatively similar for the two bi sequences, Despite the enhanced flexibility of the native TpA dinucleotide step, major deviations from the B-DNA values of helicoidal parameters were found only at the Ap and p dinucleotide steps in both sequences. Only the AT base pairs of the two sequences that contain the 5' thymine of the dimers exhibited weakened Watson-Crick hydrogen bonds and anomalous stretching, Hence, we conclude that the pattern of structural perturbations responsible for recognition of cis, syn thymine dimers by repair enzymes is not sensitive to their sequence context. C1 PACIFIC NW LAB, MOL BIOSCI DEPT, RICHLAND, WA 99352 USA. PACIFIC NW LAB, ENVIRONM MOL SCI LAB, RICHLAND, WA 99352 USA. NR 35 TC 14 Z9 14 U1 0 U2 0 PU OXFORD UNIV PRESS PI OXFORD PA GREAT CLARENDON ST, OXFORD, ENGLAND OX2 6DP SN 0305-1048 J9 NUCLEIC ACIDS RES JI Nucleic Acids Res. PD APR 1 PY 1997 VL 25 IS 7 BP 1432 EP 1436 DI 10.1093/nar/25.7.1432 PG 5 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA WR295 UT WOS:A1997WR29500017 PM 9060440 ER PT J AU Johnson, RW McHugh, PR Knoll, DA AF Johnson, RW McHugh, PR Knoll, DA TI High-order scheme implementation using Newton-Krylov solution methods SO NUMERICAL HEAT TRANSFER PART B-FUNDAMENTALS LA English DT Article ID NONSYMMETRIC LINEAR-SYSTEMS; INCOMPRESSIBLE NAVIER-STOKES; MINIMAL RESIDUAL ALGORITHM; ITERATIVE SOLUTION; ENERGY EQUATIONS AB Implementation of high-order discretization for the convective transport terms in the inexact Newton method for a benchmark fluid flow and heat transfer problem using various solution configurations at two Reynolds numbers has been investigated. These configurations include fully consistent discretization of the Jacobian, preconditioner and residual of the Newton method, low-order preconditioning using a matrix-free method to approximate the action of the Jacobian, and defect correction or low-order Jacobian and preconditioning. The residual in each case employs high order discretization to preserve the high-order solution. Two preconditioners, point incomplete lower-upper factorization ILU(k) and block incomplete lower-upper factorization BILU(k) for k = 0, 1, 2 were applied. Also, ''one-way'' multigriding and capping the inner iterations was applied to determine the behavior of the solution performance. It was determined that overall, the configuration using low-order preconditioning with ILU(1) BILU(1) or BILU(2) mesh sequencing, and inner linear solve iterations capped at the same value of the dimension n, used with the GMRES(n) iterative solver (i.e., no restarts), performed best for time, memory, and robustness considerations. C1 LOCKHEED IDAHO TECHNOL CO,IDAHO NATL ENGN LAB,IDAHO FALLS,ID 83415. NR 28 TC 8 Z9 10 U1 0 U2 0 PU HEMISPHERE PUBL CORP PI BRISTOL PA 1900 FROST ROAD, SUITE 101, BRISTOL, PA 19007-1598 SN 1040-7790 J9 NUMER HEAT TR B-FUND JI Numer Heat Tranf. B-Fundam. PD APR-MAY PY 1997 VL 31 IS 3 BP 295 EP 312 DI 10.1080/10407799708915111 PG 18 WC Thermodynamics; Mechanics SC Thermodynamics; Mechanics GA WW633 UT WOS:A1997WW63300003 ER PT J AU Jones, ND Wolf, MO Giaquinta, DM AF Jones, ND Wolf, MO Giaquinta, DM TI Synthesis of a ferrocenyl-capped ruthenium(II) bis(acetylide) complex: A model for organometallic molecular wires SO ORGANOMETALLICS LA English DT Article ID POLY-YNE POLYMERS; SIGMA-ACETYLIDE COMPLEXES; TRANSITION-METALS; MAIN CHAIN; RIGID-ROD; NONLINEAR OPTICS; RHODIUM; LIGAND; PLATINUM; NICKEL AB trans-Ru(dppm)(2)(C=CFc)(2) (1, dppm = Ph(2)-PCH(2)PPh(2), Fc = ferrocenyl) was prepared by the CuI-catalyzed coupling of FcC=CSn(n-Bu)(3) with cis-RuCl2-(dppm)(2). We have demonstrated by cyclic voltammetry that the ruthenium(II) bis(acetylide) bridge, -C=C-Ru-(dppm)(2)-C=C-, of 1 enhances the ground-state electronic communication between terminal ferrocenyl groups compared to the all-carbon butadiynyl bridge of 1,4-diferrocenylbutadiyne, Fc-C=C-C=C-Fc. C1 UNIV BRITISH COLUMBIA, DEPT CHEM, VANCOUVER, BC V6T 1Z1, CANADA. ARGONNE NATL LAB, DIV CHEM, ARGONNE, IL 60439 USA. NR 40 TC 119 Z9 119 U1 0 U2 11 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0276-7333 J9 ORGANOMETALLICS JI Organometallics PD APR 1 PY 1997 VL 16 IS 7 BP 1352 EP 1354 DI 10.1021/om960849h PG 3 WC Chemistry, Inorganic & Nuclear; Chemistry, Organic SC Chemistry GA WR500 UT WOS:A1997WR50000002 ER PT J AU Buretea, MA Tilley, TD AF Buretea, MA Tilley, TD TI Poly(ferrocenylenevinylene) from ring-opening metathesis polymerization of ansa-(vinylene)ferrocene SO ORGANOMETALLICS LA English DT Article ID FACE METALLOCENE POLYMERS; CONJUGATED POLYMERS; ALKYLIDENE COMPLEXES; COUPLING REACTIONS; TITANIUM; BRIDGE; POLY(VINYLFERROCENE); <1>FERROCENOPHANES; FERROCENOPHANES; COPOLYMERS AB The vinylene-bridged ansa-ferrocene complex [(eta(5)-C5H4)CH=CH(eta(5)-C5H4)]Fe (1) was synthesized by the McMurry coupling of 1,1'-ferrocenedicarbaldehyde (2). The ring opening metathesis polymerization (ROMP) of this strained metallocene gave poly(ferrocenylenevinylene) (3) as an insoluble orange solid which has a conductivity of 10(-3) Omega(-1) cm(-1) after doping with iodine. Partially soluble materials resulted when 1 was copolymerized with norbornene to yield a block copolymer. C1 UNIV CALIF BERKELEY,DEPT CHEM,BERKELEY,CA 94720. UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV CHEM SCI,BERKELEY,CA 94720. NR 65 TC 121 Z9 121 U1 1 U2 18 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0276-7333 J9 ORGANOMETALLICS JI Organometallics PD APR 1 PY 1997 VL 16 IS 7 BP 1507 EP 1510 DI 10.1021/om960940l PG 4 WC Chemistry, Inorganic & Nuclear; Chemistry, Organic SC Chemistry GA WR500 UT WOS:A1997WR50000023 ER PT J AU Meffe, GK AF Meffe, GK TI Biodiversity and base values SO ORYX LA English DT Editorial Material C1 SAVANNAH RIVER ECOL LAB,AIKEN,SC 29802. RP Meffe, GK (reprint author), UNIV GEORGIA,ATHENS,GA 30602, USA. NR 0 TC 5 Z9 5 U1 0 U2 1 PU BLACKWELL SCIENCE LTD PI OXFORD PA P O BOX 88, OSNEY MEAD, OXFORD, OXON, ENGLAND OX2 0NE SN 0030-6053 J9 ORYX JI Oryx PD APR PY 1997 VL 31 IS 2 BP 78 EP 80 PG 3 WC Ecology SC Environmental Sciences & Ecology GA WR751 UT WOS:A1997WR75100002 ER PT J AU Hanrahan, RJ Butt, DP AF Hanrahan, RJ Butt, DP TI Oxidation kinetics and mechanisms of Ti-Ta alloys SO OXIDATION OF METALS LA English DT Article DE titanium; tantalum; titanium alloy; oxidation mechanism; oxidation kinetics AB The oxidation kinetics of alloys containing nominally 5, 40, and 60 weight percent Ta, as well as pure Ti and Ta, were measured for 16 hr in argon-20% oxygen or pure oxygen at 800, 1000, 1200 and 1400 degrees C. These three alloys were chosen as representative of low, intermediate and high-Ta content for comparison to previous studies. In addition to TGA, specimens were examined using scanning electron microscopy, electron microprobe, and X-ray diffraction. The effect of Ta on the oxidation of Ti is explained by an increase in the compositional range of the oxygen-stabilized alpha-phase while apparently reducing the solubility of oxygen and the diffusivity of Ti in both the alpha- and beta-phases. The composition which exhibits the minimum oxidation rate varies depending on the temperature and atmosphere, but is governed by the solubility of Ta in oxygen-stabilized,alpha-Ti. RP Hanrahan, RJ (reprint author), LOS ALAMOS NATL LAB,DIV MAT SCI & TECHNOL,LOS ALAMOS,NM 87545, USA. RI Butt, Darryl/B-7480-2008 OI Butt, Darryl/0000-0003-4501-8864 NR 16 TC 13 Z9 13 U1 5 U2 12 PU PLENUM PUBL CORP PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 SN 0030-770X J9 OXID MET JI Oxid. Met. PD APR PY 1997 VL 47 IS 3-4 BP 317 EP 353 DI 10.1007/BF01668517 PG 37 WC Metallurgy & Metallurgical Engineering SC Metallurgy & Metallurgical Engineering GA WL468 UT WOS:A1997WL46800008 ER PT J AU Ortiz, J Mix, A Hostetler, S Kashgarian, M AF Ortiz, J Mix, A Hostetler, S Kashgarian, M TI The California current of the last glacial maximum: Reconstruction at 42 degrees N based on multiple proxies SO PALEOCEANOGRAPHY LA English DT Article ID NORTHERN CALIFORNIA; PACIFIC-OCEAN; SURFACE; FORAMINIFERA; TEMPERATURE; SYSTEM AB Multiple paleoceanographic proxies in a zonal transect across the California Current near 42 degrees N record modem and last glacial maximum (LGM) thermal and nutrient gradients. The offshore thermal gradient, derived from foraminiferal species assemblages and oxygen isotope data, was similar at the LGM to that at present (warmer offshore), but average temperatures were 3.3 degrees +/-1.5 degrees C colder. Observed gradients require that the sites remained under the southward flow of the California Current, and thus that the polar front remained north of 42 degrees N during the LGM. Carbon isotopic and foraminiferal flux data suggests enhanced nutrients and productivity of foraminfera in the northern California Current up to 650 km offshore. In contrast, marine organic carbon and coastal diatom burial rates decreased during the LGM. These seemingly contradictory results are reconciled by model simulations of the LGM wind- field, which suggest that wind stress curl at 42 degrees N (and thus open-ocean upwelling) increased, while offshore Ekman transport (and thus coastal upwelling) decreased during the last ice age. The ecosystem of the northern California Current during the LGM approximated that of the modem Gulf of Alaska. Cooling anti production in this legion was thus driven by stronger open-ocean upwelling and/or southward flow of high-latitude water masses, rather than by coastal upwelling. C1 OREGON STATE UNIV,COLL OCEAN & ATMOSPHER SCI,CORVALLIS,OR 97331. LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 92717. US EPA,US GEOL SURVEY,CORVALLIS,OR 97330. RI Kashgarian, Michaele/E-1665-2011; Ortiz, Joseph/E-1144-2011 OI Kashgarian, Michaele/0000-0001-7824-8418; Ortiz, Joseph/0000-0002-6583-3850 NR 48 TC 53 Z9 56 U1 0 U2 2 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0883-8305 J9 PALEOCEANOGRAPHY JI Paleoceanography PD APR PY 1997 VL 12 IS 2 BP 191 EP 205 DI 10.1029/96PA03165 PG 15 WC Geosciences, Multidisciplinary; Oceanography; Paleontology SC Geology; Oceanography; Paleontology GA WQ646 UT WOS:A1997WQ64600004 ER PT J AU Dongarra, JJ Hammarling, S Walker, DW AF Dongarra, JJ Hammarling, S Walker, DW TI Key concepts for parallel out-of-core LU factorization SO PARALLEL COMPUTING LA English DT Article DE out-of-core computation; LU factorization; parallel computing; parallel I/O ID LINEAR ALGEBRA SUBPROGRAMS; SET AB This paper considers key ideas in the design of out-of-core dense LU factorization routines. A left-looking variant of the LU factorization algorithm is shown to require less I/O to disk than the right-looking variant, and is used to develop a parallel, out-of-core implementation, This implementation makes use of a small library of parallel I/O routines, together with ScaLAPACK and PBLAS routines, Results for runs on an Intel Paragon are presented and interpreted using a simple performance model. C1 NAG LTD,OXFORD OX2 8DR,ENGLAND. 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 Walker, David/B-7978-2010; Dongarra, Jack/E-3987-2014; OI Walker, David/0000-0002-1360-6330 NR 19 TC 9 Z9 9 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0167-8191 J9 PARALLEL COMPUT JI Parallel Comput. PD APR PY 1997 VL 23 IS 1-2 BP 49 EP 70 DI 10.1016/S0167-8191(96)00096-8 PG 22 WC Computer Science, Theory & Methods SC Computer Science GA WW795 UT WOS:A1997WW79500005 ER PT J AU Lamberth, C AF Lamberth, C TI Intramolecular C-glycosylation of a novel carbohydrate-derived phosphinite SO PHARMAZIE LA English DT Article ID AMINO-ACID PRECURSORS; HYDROGENATION; DERIVATIVES; COMPLEX; FAMILY C1 LAWRENCE BERKELEY LAB,DEPT BIOSCI,BERKELEY,CA. NR 14 TC 0 Z9 0 U1 0 U2 0 PU GOVI-VERLAG GMBH PI ESCHBORN PA PHARMAZEUTISCHER VERLAG GINNHEIMER STRASSE 26, D-65760 ESCHBORN, GERMANY SN 0031-7144 J9 PHARMAZIE JI Pharmazie PD APR PY 1997 VL 52 IS 4 BP 325 EP 326 PG 2 WC Chemistry, Medicinal; Chemistry, Multidisciplinary; Pharmacology & Pharmacy SC Pharmacology & Pharmacy; Chemistry GA WU588 UT WOS:A1997WU58800018 ER PT J AU BussmannHolder, A Genzel, L Bishop, AR Simon, A AF BussmannHolder, A Genzel, L Bishop, AR Simon, A TI The role of apical oxygen in superconducting cuprates SO PHILOSOPHICAL MAGAZINE B-PHYSICS OF CONDENSED MATTER STATISTICAL MECHANICS ELECTRONIC OPTICAL AND MAGNETIC PROPERTIES LA English DT Article ID HIGH-TEMPERATURE SUPERCONDUCTORS; SPIN-LATTICE RELAXATION; T-C OXIDES; GAP ANISOTROPY; ORDER-PARAMETER; YBA2CU3O7; ELECTRON; DYNAMICS; BI2SR2CACU2O8; SCATTERING AB Using a structure specific three-dimensional superconducting gap function, derived for YBCO, the BCS coherence factors are evaluated. They are used to calculate the low-frequency electromagnetic response in the superconducting state and good agreement with experiment is obtained. It is found that the apex oxygen ion contributes dominantly to the low-frequency properties which have been evidenced elsewhere as favouring d-wave pairing. C1 LOS ALAMOS NATL LAB,DIV THEORET,LOS ALAMOS,NM 87545. RP BussmannHolder, A (reprint author), MAX PLANCK INST FESTKORPERFORSCH,HEISENBERGSTR 1,D-70569 STUTTGART,GERMANY. NR 36 TC 3 Z9 3 U1 0 U2 1 PU TAYLOR & FRANCIS LTD PI LONDON PA ONE GUNPOWDER SQUARE, LONDON, ENGLAND EC4A 3DE SN 0141-8637 J9 PHILOS MAG B JI Philos. Mag. B-Phys. Condens. Matter Stat. Mech. Electron. Opt. Magn. Prop. PD APR PY 1997 VL 75 IS 4 BP 463 EP 469 DI 10.1080/13642819708202331 PG 7 WC Materials Science, Multidisciplinary; Mechanics; Physics, Applied; Physics, Condensed Matter SC Materials Science; Mechanics; Physics GA WR296 UT WOS:A1997WR29600001 ER PT J AU Arko, AJ Joyce, JJ Andrews, AB Mandrus, D Moshopoulou, E Fisk, Z Canfield, PC AF Arko, AJ Joyce, JJ Andrews, AB Mandrus, D Moshopoulou, E Fisk, Z Canfield, PC TI The 5f band structure of antiferromagnetic USb2 from angle-resolved photoemission spectroscopy: Application to heavy fermions SO PHILOSOPHICAL MAGAZINE B-PHYSICS OF CONDENSED MATTER STATISTICAL MECHANICS ELECTRONIC OPTICAL AND MAGNETIC PROPERTIES LA English DT Article ID RESONANT PHOTOEMISSION; SYSTEMS; UPT3; ELECTRONS; SPECTRA; STATE; UIR3 AB We show the first direct observation or 5f band dispersion in an antiferromagnetic 5f compound, USb2, closely related to heavy fermions C1 FLORIDA STATE UNIV,NATL HIGH MAGNET FIELD LAB,TALLAHASSEE,FL 32306. IOWA STATE UNIV,AMES LAB,AMES,IA 50011. RP Arko, AJ (reprint author), LOS ALAMOS NATL LAB,POB 1663,LOS ALAMOS,NM 87545, USA. RI Mandrus, David/H-3090-2014; Canfield, Paul/H-2698-2014 NR 26 TC 15 Z9 15 U1 0 U2 6 PU TAYLOR & FRANCIS LTD PI LONDON PA ONE GUNPOWDER SQUARE, LONDON, ENGLAND EC4A 3DE SN 0141-8637 J9 PHILOS MAG B JI Philos. Mag. B-Phys. Condens. Matter Stat. Mech. Electron. Opt. Magn. Prop. PD APR PY 1997 VL 75 IS 4 BP 603 EP 610 DI 10.1080/13642819708202341 PG 8 WC Materials Science, Multidisciplinary; Mechanics; Physics, Applied; Physics, Condensed Matter SC Materials Science; Mechanics; Physics GA WR296 UT WOS:A1997WR29600011 ER PT J AU Uphaus, RA Fang, JY Picorel, R Chumanov, G Wang, JY Cotton, TM Seibert, M AF Uphaus, RA Fang, JY Picorel, R Chumanov, G Wang, JY Cotton, TM Seibert, M TI Langmuir-Blodgett and X-ray diffraction studies of isolated photosystem II reaction centers in monolayers and multilayers: Physical dimensions of the complex SO PHOTOCHEMISTRY AND PHOTOBIOLOGY LA English DT Article ID PHOTOSYNTHETIC REACTION CENTER; RHODOBACTER-SPHAEROIDES; 3-DIMENSIONAL STRUCTURE; PROTEIN INTERACTIONS; FILMS; MEMBRANES; SURFACE; RESOLUTION; SYSTEM AB The photosystem II (PSII) reaction center (RC) is a hydrophobic intrinsic protein complex that drives the water-oxidation process of photosynthesis, Unlike the bacterial RC complex, an X-ray crystal structure of the PSII RC is not available. In order to determine the physical dimensions of the isolated PSII RC complex, we applied Langmuir techniques to determine the cross-sectional area of an isolated RC in a condensed monolayer film, Low-angle X-ray diffraction results obtained by examining Langmuir-Blodgett multilayer films of alternating PSII RC/Cd stearate monolayers were used to determine the length (or height; z-direction, perpendicular to the plane of the original membrane) of the complex, The values obtained for a PSII RC monomer were 26 nm(2) and 4.8 nm, respectively, and the structural integrity of the RC in the multilayer film was confirmed by several approaches, Assuming a cylindrical-type RC structure, the above dimensions lead to a predicted volume of about 125 nm(3), This value is very close to the expected volume of 118 nm(3), calculated from the known molecular weight and partial specific volume of the PSII RC proteins, This same type of comparison was also made with the Rhodobacter sphaeroides RC based on published data, and we conclude that the PSII RC is much shorter in length and has a more regular solid geometric structure than the bacterial RC. Furthermore, the above dimensions of the PSII RC and those of PSII core (RC plus proximal antenna) proteins protruding outside the plane of the PSII membrane into the lumenal space as imaged by scanning tunneling microscopy (Seibert, Aust. J. Pl. Physiol. 22, 161-166, 1995) fit easily into the known dimensions of the PSII core complex visualized by others as electron-density projection maps, From this we conclude that the in situ PSII core complex is a dimeric structure containing two copies of the PSII RC. C1 NATL RENEWABLE ENERGY LAB,BASIC SCI CTR,GOLDEN,CO 80401. IOWA STATE UNIV,AMES LAB,AMES,IA 50011. IOWA STATE UNIV,DEPT CHEM,AMES,IA 50011. CSIC,ESTAC EXPT AULA DEI,ZARAGOZA,SPAIN. RI PICOREL, RAFAEL/K-7930-2014 OI PICOREL, RAFAEL/0000-0003-3791-129X FU NIGMS NIH HHS [GM48000] NR 37 TC 10 Z9 10 U1 0 U2 0 PU AMER SOC PHOTOBIOLOGY PI AUGUSTA PA BIOTECH PARK, 1021 15TH ST, SUITE 9, AUGUSTA, GA 30901-3158 SN 0031-8655 J9 PHOTOCHEM PHOTOBIOL JI Photochem. Photobiol. PD APR PY 1997 VL 65 IS 4 BP 673 EP 679 DI 10.1111/j.1751-1097.1997.tb01910.x PG 7 WC Biochemistry & Molecular Biology; Biophysics SC Biochemistry & Molecular Biology; Biophysics GA WV985 UT WOS:A1997WV98500015 PM 9114743 ER PT J AU Wickham, JD ONeill, RV Riitters, KH Wade, TG Jones, KB AF Wickham, JD ONeill, RV Riitters, KH Wade, TG Jones, KB TI Sensitivity of selected landscape pattern metrics to land-cover misclassification and differences in land-cover composition SO PHOTOGRAMMETRIC ENGINEERING AND REMOTE SENSING LA English DT Article ID DIVERSITY; ECOLOGY; GEORGIA; ERROR; MAPS AB Calculation of landscape metrics from land-cover data is becoming increasingly common. Some studies have shown that these measurements are sensitive to differences in land-cover composition, but none are known to have tested also their sensitivity to land-cover misclassification. An error simulation model was written to test the sensitivity of selected landscape pattern metrics to misclassification, and regression analysis was used to determine if these metrics were significantly related to differences in land-cover composition. Comparison of sensitivity and regression results suggests that differences in land-cover composition need to be about 5 percent greater than the misclassification rate to be confident that differences in landscape metrics are not due to misclassification. C1 OAK RIDGE NATL LAB,OAK RIDGE,TN 37831. UNIV NEVADA,DESERT RES INST,RENO,NV 89506. US EPA,LAS VEGAS,NV 89193. RI anzhi, yue/A-8609-2012 NR 32 TC 80 Z9 83 U1 1 U2 12 PU AMER SOC PHOTOGRAMMETRY PI BETHESDA PA 5410 GROSVENOR LANE SUITE 210, BETHESDA, MD 20814-2160 SN 0099-1112 J9 PHOTOGRAMM ENG REM S JI Photogramm. Eng. Remote Sens. PD APR PY 1997 VL 63 IS 4 BP 397 EP 402 PG 6 WC Geography, Physical; Geosciences, Multidisciplinary; Remote Sensing; Imaging Science & Photographic Technology SC Physical Geography; Geology; Remote Sensing; Imaging Science & Photographic Technology GA WR924 UT WOS:A1997WR92400010 ER PT J AU Guo, LP Ren, ZF Lao, JY Wang, JH Christen, DK Klabunde, CE Budai, JD AF Guo, LP Ren, ZF Lao, JY Wang, JH Christen, DK Klabunde, CE Budai, JD TI Epitaxial superconducting thin films Tl0.78Bi0.22Sr1.6Ba0.4Ca2Cu3O9-delta on (001) YSZ synthesized by laser ablation and post-annealing in pure argon SO PHYSICA C LA English DT Article ID MAGNETIC-FIELD; TAPE AB Epitaxial superconducting thin films of Tl0.78Bi0.22Sr1.6Ba0.4Ca2Cu3O9-delta ((Tl,Bi)-1223) on (001) YSZ single crystal substrates have been successfully synthesized by laser ablation and post-annealing in a tube furnace with flowing pure argon through the tube all the time during annealing. X-ray diffraction (XRD) theta-2 theta spectra showed that the films are c-axis aligned 1223 phase with a small amount of intergrown 1212 phase, while XRD phi-scans revealed that the films are also a- and b-axes aligned, with an epitaxy of the [100] of (Tl,Bi)-1223 film on the [110] of the YSZ substrate. Four-terminal electrical transport measurements showed that the zero-resistance transition temperature (T-c) was 108.5 K, and the critical current density (J(c)) at 77 K and zero field was 1.1 X 10(6) A/cm(2), both for the entire film width and for a patterned bridge. The magnetic field dependent transport J(c) suggest that (Tl,Bi)-1223 films on (001) YSZ have better flux-pinning properties than high-J(c) (Tl,Bi)-1223 films on (001) LaAlO3. C1 SUNY BUFFALO,MAT LAB,DEPT CHEM,BUFFALO,NY 14260. NEW YORK STATE INST SUPERCONDUCT,BUFFALO,NY 14260. OAK RIDGE NATL LAB,DIV SOLID STATE,OAK RIDGE,TN 37831. RI Ren, Zhifeng/B-4275-2014; Budai, John/R-9276-2016 OI Budai, John/0000-0002-7444-1306 NR 15 TC 11 Z9 11 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 1 PY 1997 VL 277 IS 1-2 BP 13 EP 18 DI 10.1016/S0921-4534(97)00057-9 PG 6 WC Physics, Applied SC Physics GA WW654 UT WOS:A1997WW65400003 ER PT J AU Dabrowski, B Rogacki, K Koenitzer, JW Poeppelmeier, KR Jorgensen, JD AF Dabrowski, B Rogacki, K Koenitzer, JW Poeppelmeier, KR Jorgensen, JD TI Optimized synthesis and properties of chemically stabilized CuSr2YCu2O7 SO PHYSICA C LA English DT Article ID HIGH-TEMPERATURE SUPERCONDUCTORS; CU; HGBA2CUO4+DELTA; PRESSURE AB Synthesis of the CuSr2YCu2O7 compounds with Re, W and Mo substituted for Cu has been optimized for the highest T-c. Materials prepared in air at 990 degrees C and annealed at 650-700 degrees C in 220 atm. O-2 are tetragonal with the transition elements substituting on the Cu-''chain'' site, have oxygen content similar to 7.3, and are superconducting with T-c similar to 70 K. The irreversibility lines show rather poor pinning characteristics when compared to Y123. Superconducting T-c values were increased up to 77 K by additional substitution of small amounts of Ca for Y. Based on a.c. susceptibility and d.c. magnetization measurements, Ca substitution improves superconducting properties making chemically stabilized CuSr2YCu2O7 materials interesting for high field applications below 30 K. C1 NORTHWESTERN UNIV,DEPT CHEM,EVANSTON,IL 60208. ARGONNE NATL LAB,DIV MAT SCI,ARGONNE,IL 60439. RP Dabrowski, B (reprint author), NO ILLINOIS UNIV,DEPT PHYS,DE KALB,IL 60115, USA. NR 23 TC 24 Z9 24 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 1 PY 1997 VL 277 IS 1-2 BP 24 EP 35 DI 10.1016/S0921-4534(97)00044-0 PG 12 WC Physics, Applied SC Physics GA WW654 UT WOS:A1997WW65400005 ER PT J AU Vergunova, GA Magunov, AI Dyakin, VM Faenov, AY Pikuz, TA Skobelev, IY Batani, D Bossi, S Bernardinello, A Flora, F DiLazzaro, P Bollanti, S Lisi, N Letardi, T Reale, A Palladino, L Scafati, A Reale, L Osterheld, AL Goldstein, WH AF Vergunova, GA Magunov, AI Dyakin, VM Faenov, AY Pikuz, TA Skobelev, IY Batani, D Bossi, S Bernardinello, A Flora, F DiLazzaro, P Bollanti, S Lisi, N Letardi, T Reale, A Palladino, L Scafati, A Reale, L Osterheld, AL Goldstein, WH TI Features of plasma produced by excimer laser at low intensities SO PHYSICA SCRIPTA LA English DT Article AB A plasma, created at interaction of short-wavelength excimer laser radiation with flat targets was investigated (t(las) = 12ns, lambda(las) = 0.308 mu n, q(las) = 4 - 8 x 10(12)W/cm2()) with the help of various X-ray spectroscopic methods. The comparison of shapes and intensities of some observable spectral lines of H-, He and Li-like ions of Na, Mg and Al with results of model calculations has allowed to determine space distributions of laser plasma parameters up to distances of 0.4mm from the target surface. Comparison of obtained results with theoretical models of absorption of short-wavelength radiation in a plasma shows, that the absorption of short-wavelength laser radiation in a plasma (at considered values of laser flux density) is executed due to inverse bremsstrahlung process in the areas with N-e[N-e,N-crit.. C1 VNIIFTRI,MULTICHARGED IONS SPECTRA DATA CTR,MENDELEYEVSK 141570,MOSCOW REGION,RUSSIA. UNIV MILAN,DIPARTIMENTO FIS,I-20133 MILAN,ITALY. IST NAZL FIS NUCL,ENEA,I-00044 FRASCATI,RM,ITALY. UNIV AQUILA,DIPARTIMENTO FIS,LAQUILA,ITALY. IST NAZL FIS NUCL,GC LNGS,LAQUILA,ITALY. IST SUPER SANITA,FIS LAB,I-00161 ROME,ITALY. IST NAZL FIS NUCL,ROME,ITALY. LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550. RP Vergunova, GA (reprint author), RUSSIAN ACAD SCI,PN LEBEDEV PHYS INST,LENINSKY PROSPEKT 53,MOSCOW,RUSSIA. RI Vergunova, Galina/M-7696-2015; OI PALLADINO, LIBERO/0000-0001-5291-6246 NR 16 TC 16 Z9 16 U1 0 U2 2 PU ROYAL SWEDISH ACAD SCIENCES PI STOCKHOLM PA PUBL DEPT BOX 50005, S-104 05 STOCKHOLM, SWEDEN SN 0281-1847 J9 PHYS SCRIPTA JI Phys. Scr. PD APR PY 1997 VL 55 IS 4 BP 483 EP 490 DI 10.1088/0031-8949/55/4/020 PG 8 WC Physics, Multidisciplinary SC Physics GA WU429 UT WOS:A1997WU42900020 ER PT J AU Hylton, DJ Snyderman, NJ AF Hylton, DJ Snyderman, NJ TI Analytic basis set for high-Z atomic QED calculations: Heavy He-like ions SO PHYSICAL REVIEW A LA English DT Article ID RADIATIVE SELF-ENERGY; DIRAC-EQUATION; GREEN-FUNCTION; COULOMB; SYSTEMS; 2-PHOTON-EXCHANGE AB A relativistic Sturmian analytic basis set representation for the Coulomb-Dirac Green function, previously studied by Zapryagaev, Manakov, and Pal'chikov [Opt. Spectrosc. 52, 248 (1982)], is investigated for application to high-Z atomic QED calculations. This pseudoeigenfunction representation follows from exact identities starting from the Whittaker function representation. It eliminates the radial ordering problem of that representation, and so is particularly useful for numerical calculation of the perturbation theory Feynman diagrams with more than one electron Green function. While the Green function represents discrete bound states, and both positive and negative energy continuum states, the Sturmian (bound-state-like) form for the pseudoeigenfunctions makes it possible to more analytically calculate matrix elements for full photon exchange, reducing numerical problems for high photon frequency. For He-Like Fm (Z=100) we calculate the perturbation theory equivalent of the Dirac-Fock-Breit ground-state energy, agreeing well with the Grant Code and with the numerical B-spline basis set approach results of Blundell, Mohr, Johnson, and Sapirstein [Phys. Rev. A 48, 2615 (1993)]. Preliminary results on the relativistic and QED correlation are also reported. C1 LAWRENCE LIVERMORE NATL LAB, LIVERMORE, CA 94550 USA. RP Hylton, DJ (reprint author), SPELMAN COLL, ATLANTA, GA 30314 USA. NR 35 TC 4 Z9 4 U1 0 U2 0 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1050-2947 J9 PHYS REV A JI Phys. Rev. A PD APR PY 1997 VL 55 IS 4 BP 2651 EP 2661 DI 10.1103/PhysRevA.55.2651 PG 11 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA WT252 UT WOS:A1997WT25200029 ER PT J AU Johnson, WR Cheng, KT Plante, DR AF Johnson, WR Cheng, KT Plante, DR TI Hyperfine structure of 2(3)P levels of heliumlike ions SO PHYSICAL REVIEW A LA English DT Article ID CONFIGURATION-INTERACTION CALCULATIONS; FINE-STRUCTURE; PRECISION-MEASUREMENT; STATE; TRANSITIONS; ATOMS AB A systematic calculation of the hyperfine structure of 2 P-3 levels of heliumlike ions is presented. Reduced matrix elements of the magnetic-dipole hyperfine operator between substates of the 2 P-1,P-3 states are evaluated using relativistic configuration-interaction wave functions that account for both Coulomb and Breit interactions. These matrix elements, together with the energy intervals Delta E(10)=E(2(3)P(1))-E(2 P-3(0)), Delta E(20)=E(2 P-3(2))-E(2 P-3(0)), and Delta E(st)=E(2 P-1(1))-E(2 P-3(0)), are tabulated for ions with nuclear charges in the range Z=2-100. For Z=2, the matrix elements are in close agreement with precise nonrelativistic variational calculations, but as Z increases from 2 to 10, the present values deviate smoothly from the variational values owing to relativistic corrections. Applications are given to determine the hyperfine structure of He-3, Li-6,7(+), Be-9(2+), and F-19(7+). Hyperfine quenching rates of 2 P-3(0) states are calculated using a radiation-damping formalism for all stable isotopes in the range Z=6-92. Quenching rates of 2 P-3(2) states are also calculated for selected ions. For Z=9-29, the 2 P-3(0) quenching rates are in good agreement with relativistic 1/Z calculations. For Z>40, the diagonal hyperfine matrix elements disagree in sign with previously published multiconfiguration Dirac-Fock values. In view of these differences, the present matrix elements are used to reevaluate the fine-structure intervals Delta E(10) inferred from hyperfine quenching experiments for the ions Ni26+, Ag45+, and Gd62+. C1 LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550. STETSON UNIV,CTR INFORMAT TECHNOL,DE LAND,FL 32720. RP Johnson, WR (reprint author), UNIV NOTRE DAME,DEPT PHYS,NOTRE DAME,IN 46556, USA. NR 32 TC 44 Z9 46 U1 0 U2 1 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1050-2947 J9 PHYS REV A JI Phys. Rev. A PD APR PY 1997 VL 55 IS 4 BP 2728 EP 2742 DI 10.1103/PhysRevA.55.2728 PG 15 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA WT252 UT WOS:A1997WT25200037 ER PT J AU Ihra, W MotaFurtado, F OMahony, PF Macek, JH AF Ihra, W MotaFurtado, F OMahony, PF Macek, JH TI Threshold law for the triplet state for electron-impact ionization in the Temkin-Poet model SO PHYSICAL REVIEW A LA English DT Article ID CROSS-SECTIONS; NEAR-THRESHOLD; SCATTERING; HYDROGEN AB We derive the analytical threshold behavior for the triplet cross section for electron-impact ionization in the Temkin-Poet model. The analytical results indicate that the most recent numerical calculations may fail to reproduce the correct threshold behavior in an energy regime below about E=0.1 a.u. We also present an analytical expression for the energy distribution of the two electrons near threshold. C1 UNIV TENNESSEE,DEPT PHYS & ASTRON,KNOXVILLE,TN 37996. OAK RIDGE NATL LAB,OAK RIDGE,TN 37831. RP Ihra, W (reprint author), UNIV LONDON,ROYAL HOLLOWAY & BEDFORD NEW COLL,DEPT MATH,EGHAM TW20 0EX,SURREY,ENGLAND. NR 20 TC 7 Z9 7 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1050-2947 J9 PHYS REV A JI Phys. Rev. A PD APR PY 1997 VL 55 IS 4 BP 3250 EP 3253 DI 10.1103/PhysRevA.55.3250 PG 4 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA WT252 UT WOS:A1997WT25200099 ER PT J AU Nilsen, J AF Nilsen, J TI Analysis of a picosecond-laser-driven Ne-like Ti x-ray laser SO PHYSICAL REVIEW A LA English DT Article ID SELENIUM AB This paper models recent experiments in which a solid titanium target was illuminated by several joules of combined energy from a nanosecond laser pulse to create a preplasma followed by a picosecond laser pulse to drive the gain. Gains greater than 200 cm(-1) are predicted for the Ne-like Ti 3p S-1(0)-->3s P-1(1) transition at 326 Angstrom, which is driven by the monopole collisional excitation. High gain is also predicted for the 3d P-1(1)-->3p P-1(1) transition at 301 Angstrom, which is driven by a combination of collisional excitation and self-photopumping. We also discuss the possibilities for driving a Ne-like Ge laser using this approach. RP Nilsen, J (reprint author), LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550, USA. NR 18 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 1050-2947 J9 PHYS REV A JI Phys. Rev. A PD APR PY 1997 VL 55 IS 4 BP 3271 EP 3274 DI 10.1103/PhysRevA.55.3271 PG 4 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA WT252 UT WOS:A1997WT25200105 ER PT J AU Chang, YC James, RB AF Chang, YC James, RB TI Phonon dispersion and polar-optical scattering in 2H PbI2 SO PHYSICAL REVIEW B LA English DT Article ID ELECTRONIC-STRUCTURE AB Theoretical studies of phonon-dispersion curves and the polar-optical scattering process for 2H PbI2 are presented. A rigid-ion model with anisotropic effective charges is used to calculate the phonon-dispersion curves. The carrier mobility and its anisotropy due to polar-optical scattering as a function of temperature are calculated. Results are in good agreement with the experimental data. C1 UNIV ILLINOIS,MAT RES LAB,URBANA,IL 61801. SANDIA NATL LABS,ADV ELECT MFG TECHNOL DEPT,LIVERMORE,CA 94551. RP Chang, YC (reprint author), UNIV ILLINOIS,DEPT PHYS,1110 W GREEN ST,URBANA,IL 61801, USA. RI Chang, Yia-Chung/F-4239-2011 NR 20 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 1 PY 1997 VL 55 IS 13 BP 8219 EP 8225 DI 10.1103/PhysRevB.55.8219 PG 7 WC Physics, Condensed Matter SC Physics GA WV252 UT WOS:A1997WV25200037 ER PT J AU Fishman, RS Viswanath, VS AF Fishman, RS Viswanath, VS TI Density of states in chromium alloys SO PHYSICAL REVIEW B LA English DT Article ID SOLITON LATTICE STRUCTURE; TEMPERATURE-DEPENDENCE; PHASE-DIAGRAM; WAVES; CR; ENERGY AB Both the spin- and charge-density waves of Cr alloys have significant effects on the joint density-of-states rho(omega) of the nested electron and hole Fermi surfaces below the Neel temperature T-N. The random-phase approximation is used to evaluate rho(omega) within a three-band model of Cr alloys. In the commensurate phase of the spin-density wave, rho(omega) contains a single energy gap 2 Delta. At zero temperature, 2 Delta reaches a maximum value of about 370 meV and spans the Fermi energy, which is shifted upwards by the presence of a charge-density wave (CDW). In the incommensurate phase, rho(omega) contains two energy gaps Delta(1)' and Delta(1) above and below midgap states. If the CDW order parameter delta vanishes, then Delta(1)'=Delta(1) and both reach a maximum of about 130 meV at T=0; if delta is nonzero, then Delta(1)'3d) transitions. No enhancement is observed at the dipolar (1s-->4p) maximum. The quadrupolar resonant scattering amplitude is estimated to be similar to 0.01r(0). C1 BROOKHAVEN NATL LAB,NATL SYNCHROTRON LIGHT SOURCE DEPT,UPTON,NY 11973. RISO NATL LAB,DEPT SOLID STATE PHYS,DK-4000 ROSKILDE,DENMARK. RP Hill, JP (reprint author), BROOKHAVEN NATL LAB,DEPT PHYS,UPTON,NY 11973, USA. RI McMorrow, Desmond/C-2655-2008 OI McMorrow, Desmond/0000-0002-4947-7788 NR 23 TC 48 Z9 48 U1 0 U2 8 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 1 PY 1997 VL 55 IS 14 BP R8662 EP R8665 PG 4 WC Physics, Condensed Matter SC Physics GA WW802 UT WOS:A1997WW80200012 ER PT J AU Kogan, VG Bullock, M Harmon, B Miranovic, P DobrosavljevicGrujic, L Gammel, PL Bishop, DJ AF Kogan, VG Bullock, M Harmon, B Miranovic, P DobrosavljevicGrujic, L Gammel, PL Bishop, DJ TI Vortex lattice transitions in borocarbides SO PHYSICAL REVIEW B LA English DT Article ID SUPERCONDUCTORS AB Nonlocal corrections to the London model are used to describe vortex lattices in LuNi2B2C. Within this scheme in fields along the c axis, vortices should form a square lattice (rotated 45 degrees relative to the crystal axes a and b) at large fields, should transform to a triangular one at a field H-2, and to another triangular lattice at a still lower field H-1. We argue that the transition at H-2 is of second order, whereas at H-1 it is of first order. In tilted fields, H-2 is predicted to move to higher fields. Neutron-scattering data for ErNi2B2C are discussed. C1 IOWA STATE UNIV SCI & TECHNOL,DEPT PHYS,AMES,IA 50011. INST PHYS,YU-11001 BELGRADE,YUGOSLAVIA. AT&T BELL LABS,LUCENT TECHNOL,MURRAY HILL,NJ 07974. RP Kogan, VG (reprint author), US DOE,AMES LAB,AMES,IA 50011, USA. NR 19 TC 158 Z9 158 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 1 PY 1997 VL 55 IS 14 BP R8693 EP R8696 PG 4 WC Physics, Condensed Matter SC Physics GA WW802 UT WOS:A1997WW80200020 ER PT J AU Mints, RG Kogan, VG AF Mints, RG Kogan, VG TI Josephson junctions with alternating critical current density SO PHYSICAL REVIEW B LA English DT Article AB The magnetic-field dependence of the critical current I-c(H) is considered for a short Josephson junction with the critical current density j(c) alternating along the tunnel contact. Two model cases, periodic and randomly alternating j(c), are treated in detail. Recent experimental data on I-c(H) for grain-boundary Josephson junctions in YBa2Cu3Ox are discussed. C1 IOWA STATE UNIV SCI & TECHNOL,AMES LAB,AMES,IA 50011. IOWA STATE UNIV SCI & TECHNOL,DEPT PHYS,AMES,IA 50011. RP Mints, RG (reprint author), TEL AVIV UNIV,RAYMOND & BEVERLY SACKLER FAC EXACT SCI,SCH PHYS & ASTRON,IL-69978 TEL AVIV,ISRAEL. RI Mints, Roman/A-5091-2008 NR 9 TC 42 Z9 42 U1 0 U2 6 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0163-1829 J9 PHYS REV B JI Phys. Rev. B PD APR 1 PY 1997 VL 55 IS 14 BP R8682 EP R8684 PG 3 WC Physics, Condensed Matter SC Physics GA WW802 UT WOS:A1997WW80200017 ER PT J AU Stassis, C Bullock, M Zarestky, J Canfield, PC Goldman, AI Shirane, G Shapiro, SM AF Stassis, C Bullock, M Zarestky, J Canfield, PC Goldman, AI Shirane, G Shapiro, SM TI Phonon mode coupling in superconducting LuNi2B2C SO PHYSICAL REVIEW B LA English DT Article ID INELASTIC-NEUTRON-SCATTERING; NICKEL BORIDE CARBIDES; ERNI2B2C; ORDER; NB3SN AB Recently, Kawano et al. reported that an interesting phononlike excitation, localized in q and w, appears below T-c, in the superconducting compound YNi2B2C. This interesting observation led us to perform a series of experiments on the previously studied LuNi2B2C superconducting compound covering a large range of q and w. We demonstrate that there is no new excitation and that the lowest lying excitations can be associated with the Delta(4)[xi 00] acoustic and optical phonon branches which exhibit pronounced dips at low temperatures for wave vectors close to the Fermi surface nesting vector, xi(m), characteristic of these compounds. Above T-c, as the temperature decreases the frequencies of both modes in the vicinity of xi(m) decrease and there is a shift of intensity from the upper to the lower mode, an effect characteristic of mode coupling. Below T-c, there is a dramatic decrease in the linewidth of the acoustic mode due to the opening of the superconducting gap. C1 IOWA STATE UNIV SCI & TECHNOL, DEPT PHYS & ASTRON, AMES, IA 50011 USA. BROOKHAVEN NATL LAB, UPTON, NY 11973 USA. RP Stassis, C (reprint author), IOWA STATE UNIV SCI & TECHNOL, AMES LAB, AMES, IA 50011 USA. RI Canfield, Paul/H-2698-2014 NR 21 TC 49 Z9 49 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 1 PY 1997 VL 55 IS 14 BP R8678 EP R8681 PG 4 WC Physics, Condensed Matter SC Physics GA WW802 UT WOS:A1997WW80200016 ER PT J AU Harder, A Jungclaus, A Kabadiyski, MK Kast, D Lieb, KP Rudolph, D Weiszflog, M Johnson, TD Winter, G Gross, CJ Cunningham, RA Gelletly, W Simpson, J Warner, DD Bearden, IG Shizuma, T Sletten, G Foltescu, D Roth, HA Skeppstedt, O Varley, BJ AF Harder, A Jungclaus, A Kabadiyski, MK Kast, D Lieb, KP Rudolph, D Weiszflog, M Johnson, TD Winter, G Gross, CJ Cunningham, RA Gelletly, W Simpson, J Warner, DD Bearden, IG Shizuma, T Sletten, G Foltescu, D Roth, HA Skeppstedt, O Varley, BJ TI Rotational bands in Rb-77: Spectroscopy near the Z=38 deformed shell gap SO PHYSICAL REVIEW C LA English DT Article ID ARRAY; Y-83; SR-77 AB The gamma decays of high spin states in Rb-77 populated in the reaction Ca-40(Ca-40,3p) Rb-77 were studied with the EUROGAM I gamma-ray spectrometer at Daresburp Laboratory, in conjunction with the recoil mass separator. The data were used to extend or establish three positive parity and five negative parity bands in Rb-77. Levei lifetimes and sidefeeding times were then measured with the NORDBALL gamma-ray spectrometer, using the Doppler shift attenuation method, A very detailed level scheme including many weakly populated states was established and the bands were observed over large spin ranges. The deduced lifetimes demonstrate the high collectivity of the excited states and are consistent with their having large prolate deformations. The structures of the bands and their crossings are discussed in relation to the large shell gap at prolate deformation beta(2) approximate to 0.4. C1 ROSSENDORF INC,FORSCHUNGSZENTRUM ROSSENDORF EV,D-01314 DRESDEN,GERMANY. OAK RIDGE NATL LAB,DIV PHYS,OAK RIDGE,TN 37831. SERC,DARESBURY LAB,WARRINGTON WA4 4AD,CHESHIRE,ENGLAND. NIELS BOHR INST,DK-4000 ROSKILDE,DENMARK. CHALMERS UNIV TECHNOL,DEPT PHYS,S-41296 GOTHENBURG,SWEDEN. UNIV MANCHESTER,SCHUSTER LAB,MANCHESTER M13 9PL,LANCS,ENGLAND. RP Harder, A (reprint author), UNIV GOTTINGEN,INST PHYS 2,D-37073 GOTTINGEN,GERMANY. RI Rudolph, Dirk/D-4259-2009; Bearden, Ian/M-4504-2014 OI Rudolph, Dirk/0000-0003-1199-3055; Bearden, Ian/0000-0003-2784-3094 NR 31 TC 14 Z9 14 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2813 J9 PHYS REV C JI Phys. Rev. C PD APR PY 1997 VL 55 IS 4 BP 1680 EP 1696 DI 10.1103/PhysRevC.55.1680 PG 17 WC Physics, Nuclear SC Physics GA WV240 UT WOS:A1997WV24000012 ER PT J AU Kangasmaki, A Tikkanen, P Keinonen, J Ormand, WE Raman, S AF Kangasmaki, A Tikkanen, P Keinonen, J Ormand, WE Raman, S TI Lifetimes of P-32 levels SO PHYSICAL REVIEW C LA English DT Article ID MODEL WAVE-FUNCTIONS; SHELL-MODEL; STOPPING POWER; GAMMA-RAY; TRANSITION STRENGTHS; SI-IONS; NUCLEI; INTENSITIES; CO-56; SPECTROSCOPY AB Mean lifetimes of 22 bound levels and upper lifetime limits of four more levels in P-32 below an excitation energy of 6.4 MeV were deduced from the Doppler-shift attenuation of gamma rays produced in the inverse reaction H-2(P-31,p gamma). Of these 26 levels, the lifetimes of six levels are reported here for the first time. The low-lying portion of the level scheme, the level lifetimes, and the gamma-ray branchings and reduced transition probabilities have been compared with shell-model predictions. The overall agreement is reasonably good. C1 IST NAZL FIS NUCL, SEZ MILANO, I-20133 MILAN, ITALY. OAK RIDGE NATL LAB, OAK RIDGE, TN 37831 USA. RP Kangasmaki, A (reprint author), UNIV HELSINKI, ACCELERATOR LAB, POB 43, FIN-00014 HELSINKI, FINLAND. RI Keinonen, Juhani/D-4347-2013 NR 62 TC 9 Z9 9 U1 0 U2 0 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2813 J9 PHYS REV C JI Phys. Rev. C PD APR PY 1997 VL 55 IS 4 BP 1697 EP 1714 DI 10.1103/PhysRevC.55.1697 PG 18 WC Physics, Nuclear SC Physics GA WV240 UT WOS:A1997WV24000013 ER PT J AU Fotiades, N Younes, W Cizewski, JA McNabb, DP Ding, KY Davids, CN Janssens, RVF Seweryniak, D Carpenter, MP Amro, H Decrock, P Reiter, P Nisius, D Brown, LT Fischer, S Lauritsen, T Wauters, J Bingham, CR Huyse, M Andreyev, A Conticchio, LF AF Fotiades, N Younes, W Cizewski, JA McNabb, DP Ding, KY Davids, CN Janssens, RVF Seweryniak, D Carpenter, MP Amro, H Decrock, P Reiter, P Nisius, D Brown, LT Fischer, S Lauritsen, T Wauters, J Bingham, CR Huyse, M Andreyev, A Conticchio, LF TI Spectroscopy of Po-192 SO PHYSICAL REVIEW C LA English DT Article ID MASS NUCLEI; DECAY AB Excitations in Po-192 have been studied via in-beam gamma-ray spectroscopy following the Er-164 + 164 MeV S-32 reaction. The experiment was performed at the ATLAS facility using ten Compton-suppressed Ge detectors and the Fragment Mass Analyzer. The alpha decay of Po-192 has been used to identify prompt gamma-ray transitions by means of the recoil decay tagging technique. The first three excited states of Po-192 were established. The particle-core model has been successfully used to model these excitations and the quasiparticle random phase approximation has been applied to extract microscopic wave functions of the 2(1)(+) states. C1 ARGONNE NATL LAB,DIV PHYS,ARGONNE,IL 60439. LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550. UNIV TENNESSEE,KNOXVILLE,TN 37996. KATHOLIEKE UNIV LEUVEN,INST KERN & STRALINGSFYS,B-3001 LOUVAIN,BELGIUM. UNIV MARYLAND,DEPT CHEM,COLLEGE PK,MD 20742. VANDERBILT UNIV,DEPT PHYS,MEMPHIS,TN. RP Fotiades, N (reprint author), RUTGERS STATE UNIV,DEPT PHYS & ASTRON,NEW BRUNSWICK,NJ 08903, USA. RI Carpenter, Michael/E-4287-2015 OI Carpenter, Michael/0000-0002-3237-5734 NR 16 TC 21 Z9 21 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2813 J9 PHYS REV C JI Phys. Rev. C PD APR PY 1997 VL 55 IS 4 BP 1724 EP 1729 DI 10.1103/PhysRevC.55.1724 PG 6 WC Physics, Nuclear SC Physics GA WV240 UT WOS:A1997WV24000015 ER PT J AU Yuly, M Fong, W Kinney, ER Maher, CJ Matthews, JL Soos, T Vail, J Wang, MY Wood, SA Gram, PAM Rebka, GA Roberts, DA AF Yuly, M Fong, W Kinney, ER Maher, CJ Matthews, JL Soos, T Vail, J Wang, MY Wood, SA Gram, PAM Rebka, GA Roberts, DA TI Pion double charge exchange and inelastic scattering on He-3 SO PHYSICAL REVIEW C LA English DT Article ID QUASI-FREE SCATTERING; ELASTIC-SCATTERING; PI-HE-4 SCATTERING; KNOCKOUT REACTIONS; NUCLEAR-REACTIONS; RESONANCE REGION; HELIUM-ISOTOPES; CROSS-SECTION; THRESHOLD; DEPENDENCE AB Measurements were made of the doubly differential cross sections for three inclusive pion reactions on He-3: pi(-) double charge exchange (DCX), and pi(+) and pi(-) inelastic scattering. The cross sections for DCX were measured at incident pion energies of 120, 180, and 240 MeV, and at angles of 25 degrees, 50 degrees, 80 degrees, 105 degrees, and 130 degrees, while inelastic scattering cross sections were measured at 120, 180, and 240 MeV and scattering angles of 50 degrees, 80 degrees, 105 degrees, and 130 degrees. In each case the outgoing pion energy spectra were measured from 10 MeV up to the kinematic limit. The DCX spectra exhibit a double-peaked structure at forward angles that can be understood as a consequence of a sequential single charge exchange mechanism. Model calculations based on this mechanism are in rough agreement with the measured spectra. The doubly differential cross sections measured for the inelastic scattering reactions exhibit a prominent quasielastic peak. A distorted-wave impulse-approximation calculation of the quasielastic cross sections has been performed and a comparison made with the measurements. C1 MIT,DEPT PHYS,CAMBRIDGE,MA 02139. MIT,NUCL SCI LAB,CAMBRIDGE,MA 02139. LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545. UNIV WYOMING,DEPT PHYS,LARAMIE,WY 82071. NR 96 TC 21 Z9 21 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2813 J9 PHYS REV C JI Phys. Rev. C PD APR PY 1997 VL 55 IS 4 BP 1848 EP 1868 DI 10.1103/PhysRevC.55.1848 PG 21 WC Physics, Nuclear SC Physics GA WV240 UT WOS:A1997WV24000029 ER PT J AU Shen, PN Dong, YB Zhang, ZY Yu, YW Lee, TSH AF Shen, PN Dong, YB Zhang, ZY Yu, YW Lee, TSH TI E2/M1 ratio of the Delta<->gamma N transition within the chiral constituent quark model SO PHYSICAL REVIEW C LA English DT Article ID PION-PHOTOPRODUCTION; ELECTROPRODUCTION; BARYONS; NUCLEON AB The chiral constituent quark model is applied to predict the magnetic M1 and electric E2 amplitudes of the Delta<->gamma N transition. It is found that the one-meson-exchange quark-quark potential due to the chiral fields enhances the E2/M1 ratio by a factor of about 2. The predicted M1+ amplitude and the E2/M1 ratio similar or equal to-1.0% are within the range determined from a recent analysis of the data of pion photoproduction. C1 CHINA CTR ADV SCI & TECHNOL,WORLD LAB,BEIJING 100080,PEOPLES R CHINA. ACAD SINICA,INST THEORET PHYS,BEIJING 100080,PEOPLES R CHINA. ARGONNE NATL LAB,DIV PHYS,ARGONNE,IL 60439. RP Shen, PN (reprint author), ACAD SINICA,INST HIGH ENERGY PHYS,BEIJING 100039,PEOPLES R CHINA. NR 24 TC 39 Z9 42 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2813 J9 PHYS REV C JI Phys. Rev. C PD APR PY 1997 VL 55 IS 4 BP 2024 EP 2029 DI 10.1103/PhysRevC.55.2024 PG 6 WC Physics, Nuclear SC Physics GA WV240 UT WOS:A1997WV24000047 ER PT J AU Athanassopoulos, C Auerbach, LB Burman, RL Cohen, I Caldwell, DO Dieterle, BD Donahue, JB Eisner, AM Fazely, A Federspiel, FJ Garvey, GT Gray, M Gunasingha, RM Imlay, R Johnston, K Kim, HJ Louis, WC Majkic, R Margulies, J McIlhany, K Metcalf, W Mills, GB Reeder, RA Sandberg, V Smith, D Stancu, I Strossman, W Tayloe, R VanDalen, GJ Vernon, W Wadia, N Waltz, J Wang, YX White, DH Works, D Xiao, Y Yellin, S AF Athanassopoulos, C Auerbach, LB Burman, RL Cohen, I Caldwell, DO Dieterle, BD Donahue, JB Eisner, AM Fazely, A Federspiel, FJ Garvey, GT Gray, M Gunasingha, RM Imlay, R Johnston, K Kim, HJ Louis, WC Majkic, R Margulies, J McIlhany, K Metcalf, W Mills, GB Reeder, RA Sandberg, V Smith, D Stancu, I Strossman, W Tayloe, R VanDalen, GJ Vernon, W Wadia, N Waltz, J Wang, YX White, DH Works, D Xiao, Y Yellin, S TI Measurements of the reactions C-12(nu(e),e(-))N-12(gs) and C-12(nu(e),e(-))N-12 SO PHYSICAL REVIEW C LA English DT Article ID REACTION CROSS-SECTIONS; NEUTRINO; C-12; SCATTERING; NUCLEI; CARBON AB Charged current reactions of v(e) on C-12 have been studied using a mu(+) decay-at-rest v(e) beam from the Los Alamos Meson Physics Facility. More than 500 events from the exclusive reaction C-12(v(e),e(-))N-12(g.s.) were measured in a large Liquid Scintillator Neutrinro Detector (LSND). The observed energy dependence of the cross section and the angular distribution of the outgoing electron agree well with theoretical expectations. Measurements are also presented for inclusive transitions to N-12 excited states, C-12(v(e),e(-))N-12* and compared with theoretical expectations. Results are consistent with a recent continuum random phase approximation (CRPA) calculation. C1 UNIV CALIF RIVERSIDE,RIVERSIDE,CA 92521. UNIV CALIF SAN DIEGO,SAN DIEGO,CA 92093. UNIV CALIF SANTA BARBARA,SANTA BARBARA,CA 93106. UNIV CALIF STANFORD,INTERCAMPUS INST RES PARTICLE ACCELERATORS,STANFORD,CA 94309. EMBRY RIDDLE AERONAUT UNIV,PRESCOTT,AZ 86301. LINFIELD COLL,MCMINNVILLE,OR 97128. LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545. LOUISIANA STATE UNIV,BATON ROUGE,LA 70803. LOUISIANA TECH UNIV,RUSTON,LA 71272. UNIV NEW MEXICO,ALBUQUERQUE,NM 87131. SOUTHERN UNIV,BATON ROUGE,LA 70813. RP Athanassopoulos, C (reprint author), TEMPLE UNIV,PHILADELPHIA,PA 19122, USA. NR 31 TC 83 Z9 83 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2813 J9 PHYS REV C JI Phys. Rev. C PD APR PY 1997 VL 55 IS 4 BP 2078 EP 2091 DI 10.1103/PhysRevC.55.2078 PG 14 WC Physics, Nuclear SC Physics GA WV240 UT WOS:A1997WV24000053 ER PT J AU Irvine, RJ Davids, CN Woods, PJ Blumenthal, DJ Brown, LT Conticchio, LF Davinson, T Henderson, DJ Mackenzie, JA Penttila, HT Seweryniak, D Walters, WB AF Irvine, RJ Davids, CN Woods, PJ Blumenthal, DJ Brown, LT Conticchio, LF Davinson, T Henderson, DJ Mackenzie, JA Penttila, HT Seweryniak, D Walters, WB TI Proton emission from drip-line nuclei Ta-157 and Re-161 SO PHYSICAL REVIEW C LA English DT Article AB Proton radioactivities from Ta-157 and Re-161 are reported. Fusion-evaporation residues from the reaction of 270 MeV Ni-58 ions on Pd-102 and Cd-106 targets were separated according to Mle and implanted into a double-sided silicon strip detector. One Line from Ta-157 was observed with a proton energy of 927(7) keV [t(1/2)=10.1(4) ms, b(p)=3.4(12)%] from the pi s(1/2) ground state. A new alpha decay transition with energy 6117(4) keV was also observed from this state. Two proton lines from Re-161 were observed with energies 1192(6) keV [t(1/2)=0.37(4) ms, b(p)=100(7)%] and 1315(7) keV [t(1/2)=16(1) ms, b(p)=4.8(6)%] from the pi s(1/2) and pi h(11/2) states, respectively. C1 ARGONNE NATL LAB,DIV PHYS,ARGONNE,IL 60439. VANDERBILT UNIV,NASHVILLE,TN 37235. UNIV MARYLAND,DEPT CHEM,COLLEGE PK,MD 20742. RP Irvine, RJ (reprint author), UNIV EDINBURGH,DEPT PHYS & ASTRON,EDINBURGH EH8 9YL,MIDLOTHIAN,SCOTLAND. RI Penttila, Heikki/A-4420-2013 NR 10 TC 62 Z9 63 U1 0 U2 7 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2813 J9 PHYS REV C JI Phys. Rev. C PD APR PY 1997 VL 55 IS 4 BP R1621 EP R1624 PG 4 WC Physics, Nuclear SC Physics GA WV240 UT WOS:A1997WV24000002 ER PT J AU Krucken, R Asztalos, SJ Becker, JA Busse, B Clark, RM Deleplanque, MA Dewald, A Diamond, RM Fallon, P Hauschild, K Lee, IY Macchiavelli, AO MacLeod, RW Peusquens, R Schmid, GJ Stephens, FS Vetter, K vonBrentano, P AF Krucken, R Asztalos, SJ Becker, JA Busse, B Clark, RM Deleplanque, MA Dewald, A Diamond, RM Fallon, P Hauschild, K Lee, IY Macchiavelli, AO MacLeod, RW Peusquens, R Schmid, GJ Stephens, FS Vetter, K vonBrentano, P TI Decay out of the superdeformed band in Pb-194: Electromagnetic properties SO PHYSICAL REVIEW C LA English DT Article ID LOW-SPIN STATES; CURVE METHOD; HG-192; LIFETIMES AB Lifetimes of the 14(+), 12(+), 10(+) states and, for the first time, the 8(+) state in the yrast superdeformed (SD) band of Pb-194 were measured at Gammasphere with the recoil-distance Doppler-shift method. Constant transition quadrupole moments with an average of 18.8 (11) e b were found at the bottom of the SD band. The decay out of the SD band can be viewed as governed by a small admixture of normal deformed (ND) states to the SD wave function which is assessed for the 8(+) and 10(+) SD states based on a simple mixing model. The electromagnetic properties of the ND states involved in the decay out are extracted for the first time by investigating the decay strength of the discrete linking transitions. Despite the large intensity of observed linking transitions, the new data show that the decay out of the SD band is statistical in nature. C1 UNIV COLOGNE,INST KERNPHYS,D-50937 COLOGNE,GERMANY. LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550. RP Krucken, R (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV NUCL SCI,1 CYCLOTRON RD,BERKELEY,CA 94720, USA. RI Hauschild, Karl/A-6726-2009; Dewald, Alfred/O-5810-2015; Kruecken, Reiner/A-1640-2013 OI Kruecken, Reiner/0000-0002-2755-8042 NR 24 TC 36 Z9 36 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2813 J9 PHYS REV C JI Phys. Rev. C PD APR PY 1997 VL 55 IS 4 BP R1625 EP R1629 PG 5 WC Physics, Nuclear SC Physics GA WV240 UT WOS:A1997WV24000003 ER PT J AU Millener, DJ AF Millener, DJ TI First-forbidden beta decay of N-17 and Ne-17 SO PHYSICAL REVIEW C LA English DT Article ID NUCLEI AB It is shown that differences, due to charge-dependent effects, in the N-17 and Ne-17 ground-state wave functions account for the fact that the experimentally measured branch for the beta(+) decay of Ne-17 to the first excited state of F-17 is roughly a factor of two larger than expected on the basis of nuclear matrix elements which reproduce the corresponding beta(-) branch in the decay of N-17. C1 UNIV WASHINGTON,INST NUCL THEORY,SEATTLE,WA 98195. RP Millener, DJ (reprint author), BROOKHAVEN NATL LAB,UPTON,NY 11973, USA. NR 25 TC 23 Z9 23 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2813 J9 PHYS REV C JI Phys. Rev. C PD APR PY 1997 VL 55 IS 4 BP R1633 EP R1636 PG 4 WC Physics, Nuclear SC Physics GA WV240 UT WOS:A1997WV24000005 ER PT J AU Alexopoulos, T Antoniazzi, L Arenton, M Ballagh, HC Bingham, H Blankman, A Block, M Boden, A Bonomi, G Cao, ZL Chen, TY Clark, K Cline, D Conetti, S Cooper, M Corti, G Cox, B Creti, P Dukes, C Durandet, C Elia, V Erwin, AR Fortney, L Golovatyuk, V Gorini, E Grancagnolo, F HaganIngram, K Haire, M Hanlet, P He, M Introzzi, G Jenkins, M Judd, D Kononenko, W Kowald, W Lau, K Ledovskoy, A Liguori, G Lys, J Mazur, PO McManus, A Misawa, S Mo, GH Murphy, CT Nelson, K Panareo, M Pogosian, V Ramachandran, S Rhoades, J Selove, W Smith, RP Spiegel, L Sun, JG Tokar, S Torre, P Trischuk, J Turnbull, L Wagoner, DE Wang, CR Wei, C Yang, W Yao, N Zhang, NJ Zou, BT AF Alexopoulos, T Antoniazzi, L Arenton, M Ballagh, HC Bingham, H Blankman, A Block, M Boden, A Bonomi, G Cao, ZL Chen, TY Clark, K Cline, D Conetti, S Cooper, M Corti, G Cox, B Creti, P Dukes, C Durandet, C Elia, V Erwin, AR Fortney, L Golovatyuk, V Gorini, E Grancagnolo, F HaganIngram, K Haire, M Hanlet, P He, M Introzzi, G Jenkins, M Judd, D Kononenko, W Kowald, W Lau, K Ledovskoy, A Liguori, G Lys, J Mazur, PO McManus, A Misawa, S Mo, GH Murphy, CT Nelson, K Panareo, M Pogosian, V Ramachandran, S Rhoades, J Selove, W Smith, RP Spiegel, L Sun, JG Tokar, S Torre, P Trischuk, J Turnbull, L Wagoner, DE Wang, CR Wei, C Yang, W Yao, N Zhang, NJ Zou, BT TI Differential cross sections of J/psi and psi' in 800 GeV/c p-Si interactions SO PHYSICAL REVIEW D LA English DT Article ID MUON TRIGGER; FERMILAB; GLUONS AB We present the x(F) and p(T) differential cross sections of J/psi, and psi', respectively, in the ranges -0.05e gamma and tau->mu gamma SO PHYSICAL REVIEW D LA English DT Article ID LEPTON; LIBRARY AB A search for the lepton-family-number-violating decays tau-->e gamma and tau-->mu gamma has been performed using CLEO II data. No evidence of a signal has been found and the corresponding upper limits are B(tau-->e gamma)<2.7x10(-6) and B(tau-->mu gamma)<3.0x10(-6) at 90% C.L. C1 MCGILL UNIV,MONTREAL,PQ H3A 2T8,CANADA. ITHACA COLL,ITHACA,NY 14850. UNIV KANSAS,LAWRENCE,KS 66045. UNIV MINNESOTA,MINNEAPOLIS,MN 55455. SUNY ALBANY,ALBANY,NY 12222. OHIO STATE UNIV,COLUMBUS,OH 43210. UNIV OKLAHOMA,NORMAN,OK 73019. PURDUE UNIV,W LAFAYETTE,IN 47907. UNIV ROCHESTER,ROCHESTER,NY 14627. STANFORD UNIV,STANFORD LINEAR ACCELERATOR CTR,STANFORD,CA 94309. SO METHODIST UNIV,DALLAS,TX 75275. SYRACUSE UNIV,SYRACUSE,NY 13244. VANDERBILT UNIV,NASHVILLE,TN 37235. VIRGINIA POLYTECH INST & STATE UNIV,BLACKSBURG,VA 24061. WAYNE STATE UNIV,DETROIT,MI 48202. CALTECH,PASADENA,CA 91125. UNIV CALIF SAN DIEGO,LA JOLLA,CA 92093. UNIV CALIF SANTA BARBARA,SANTA BARBARA,CA 93106. UNIV COLORADO,BOULDER,CO 80309. CORNELL UNIV,ITHACA,NY 14853. UNIV FLORIDA,GAINESVILLE,FL 32611. HARVARD UNIV,CAMBRIDGE,MA 02138. UNIV HAWAII MANOA,HONOLULU,HI 96822. UNIV ILLINOIS,CHAMPAIGN,IL 61801. BINP,RU-630090 NOVOSIBIRSK,RUSSIA. LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94551. UNIV TEXAS,AUSTIN,TX 78712. RP Edwards, KW (reprint author), CARLETON UNIV,OTTAWA,ON K1S 5B6,CANADA. RI Schaffner, Stephen/D-1189-2011; Briere, Roy/N-7819-2014; Frasconi, Franco/K-1068-2016 OI Briere, Roy/0000-0001-5229-1039; Frasconi, Franco/0000-0003-4204-6587 NR 12 TC 44 Z9 44 U1 1 U2 1 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2821 J9 PHYS REV D JI Phys. Rev. D PD APR 1 PY 1997 VL 55 IS 7 BP R3919 EP R3923 PG 5 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA WY654 UT WOS:A1997WY65400001 ER PT J AU Grossman, EL Zhou, T BenNaim, E AF Grossman, EL Zhou, T BenNaim, E TI Towards granular hydrodynamics in two dimensions SO PHYSICAL REVIEW E LA English DT Article ID PARTICLES AB We study steady-state properties of inelastic gases in two dimensions in the presence of an energy source. We generalize previous hydrodynamic treatments to situations where high and low density regions coexist, The theoretical predictions compare well with numerical simulations in the nearly elastic limit. It is also seen that the system can achieve a nonequilibrium steady state with asymmetric velocity distributions, and we discuss the conditions under which such situations occur. C1 LOS ALAMOS NATL LAB,DIV THEORET,LOS ALAMOS,NM 87545. LOS ALAMOS NATL LAB,CTR NONLINEAR STUDIES,LOS ALAMOS,NM 87545. RP Grossman, EL (reprint author), UNIV CHICAGO,JAMES FRANCK INST,5640 S ELLIS AVE,CHICAGO,IL 60637, USA. RI Ben-Naim, Eli/C-7542-2009 OI Ben-Naim, Eli/0000-0002-2444-7304 NR 16 TC 145 Z9 146 U1 0 U2 3 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1063-651X J9 PHYS REV E JI Phys. Rev. E PD APR PY 1997 VL 55 IS 4 BP 4200 EP 4206 DI 10.1103/PhysRevE.55.4200 PG 7 WC Physics, Fluids & Plasmas; Physics, Mathematical SC Physics GA WV249 UT WOS:A1997WV24900055 ER PT J AU Hagberg, A Meron, E Rubinstein, I Zaltzman, B AF Hagberg, A Meron, E Rubinstein, I Zaltzman, B TI Order parameter equations for front transitions: Planar and circular fronts SO PHYSICAL REVIEW E LA English DT Article ID REACTION-DIFFUSION SYSTEM; ROTATING MAGNETIC-FIELD; SELF-REPLICATING SPOTS; PATTERN-FORMATION; EXCITABLE MEDIA; SPIRAL WAVES; LOCALIZED PATTERNS; LIQUID-CRYSTALS; BIFURCATIONS; DYNAMICS AB Near a parity breaking front bifurcation, small perturbations may reverse the propagation direction of fronts. Often this results in nonsteady asymptotic-motion, such as breathing and domain breakup. Exploiting the time scale differences of an activator-inhibitor model and the proximity to the front bifurcation, we derive equations of motion for planar and circular fronts. The equations involve a translational degree of freedom and an order parameter describing transitions between left and right propagating fronts. Perturbations, such as a space dependent advective field or uniform curvature (axisymmetric spots), couple these two degrees of freedom. In both cases this leads to a transition from stationary to oscillating fronts as the parity breaking bifurcation is approached. For axisymmetric spots, two additional dynamic behaviors are found: rebound and collapse. C1 LOS ALAMOS NATL LAB,DIV THEORET T7,LOS ALAMOS,NM 87545. BEN GURION UNIV NEGEV,JACOB BLAUSTEIN INST DESERT RES,IL-84990 SEDE BOQER,ISRAEL. BEN GURION UNIV NEGEV,DEPT PHYS,IL-84990 SEDE BOQER,ISRAEL. BEN GURION UNIV NEGEV,DEPT MATH,IL-84990 SEDE BOQER,ISRAEL. RP Hagberg, A (reprint author), LOS ALAMOS NATL LAB,CTR NONLINEAR STUDIES,LOS ALAMOS,NM 87545, USA. RI MERON, EHUD/F-1810-2012 NR 43 TC 22 Z9 22 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1063-651X J9 PHYS REV E JI Phys. Rev. E PD APR PY 1997 VL 55 IS 4 BP 4450 EP 4457 DI 10.1103/PhysRevE.55.4450 PG 8 WC Physics, Fluids & Plasmas; Physics, Mathematical SC Physics GA WV249 UT WOS:A1997WV24900083 ER PT J AU Mayer, B Kohler, G Rasmussen, S AF Mayer, B Kohler, G Rasmussen, S TI Simulation and dynamics of entropy-driven, molecular self-assembly processes SO PHYSICAL REVIEW E LA English DT Article ID HYDROPHOBIC HYDRATION; VESICLES; PROTEINS; WATER AB Molecular self-assembly is frequently found to generate higher-order functional structures in biochemical systems. One such example is the self-assembly of lipids in aqueous solution forming membranes, micelles, and vesicles; another is the dynamic formation and rearrangement of the cytoskeleton. These processes are often driven by local, short-range forces and therefore the dynamics is solely based on local interactions. In this paper, we introduce a cellular automata based simulation, the lattice molecular automaton, in which data structures, representing different molecular entities such as water and hydrophilic and hydrophobic monomers, share locally propagated force information on a hexagonal, two-dimensional lattice. The purpose of this level of description is the simulation of entropic and enthalpic flows in a microcanonical, molecular ensemble to gain insight about entropy-driven processes in molecular many-particle systems. Three applications are shown, i.e., modeling structural features of a polar solvent, cluster formation of hydrophobic monomers in a polar environment, and the self-assembly of polymers. Processes leading to phase separation on a molecular level are discussed. A thorough discussion of the computational details, advantages, and limitations of the lattice molecular automaton approach is given elsewhere [B. Mayer and S. Rasmussen (unpublished)]. C1 SANTA FE INST, SANTA FE, NM 87501 USA. LOS ALAMOS NATL LAB, CNLS, MS B258, LOS ALAMOS, NM 87545 USA. LOS ALAMOS NATL LAB, TSA DO SA, MS M997, LOS ALAMOS, NM 87545 USA. RP UNIV VIENNA, INST THEORET CHEM & STRAHLENCHEM, UZAII, ALTHANSTR 14, A-1090 VIENNA, AUSTRIA. NR 35 TC 29 Z9 29 U1 1 U2 9 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 2470-0045 EI 2470-0053 J9 PHYS REV E JI Phys. Rev. E PD APR PY 1997 VL 55 IS 4 BP 4489 EP 4499 DI 10.1103/PhysRevE.55.4489 PG 11 WC Physics, Fluids & Plasmas; Physics, Mathematical SC Physics GA WV249 UT WOS:A1997WV24900087 ER PT J AU Forinash, K Cretegny, T Peyrard, M AF Forinash, K Cretegny, T Peyrard, M TI Local modes and localization in a multicomponent nonlinear lattice SO PHYSICAL REVIEW E LA English DT Article ID DNA; DYNAMICS; COMPLEX AB The existence, stability, and the conditions for the formation of nonlinear localized modes are investigated in a two-component one-dimensional lattice. In spite of their possible coupling with acoustic phonons, discrete breathers can exist as exact stable solutions or show a very slow decay. Nonlinear energy localization through energy exchange between localized excitations, exhibited previously for a one-component lattice [T. Dauxois and M. Peyrard, Phys. Rev. Lett. 70, 3935.(1993)] is more general and also valid in a multicomponent lattice. A self-localization of thermal fluctuations is also observed in such a system. The model is used. to investigate the effect of bending proteins on DNA. IL shows that a bend can collect the energy of moving localized modes or insulate one part of the molecule from transfers of energy from large amplitude excitations in other parts. C1 CNRS,ECOLE NORMALE SUPER LYON,PHYS LAB,URA 1325,F-69007 LYON,FRANCE. CE SACLAY,LAB LEON BRILLOUIN,F-91191 GIF SUR YVETTE,FRANCE. LOS ALAMOS NATL LAB,CTR NONLINEAR STUDIES,LOS ALAMOS,NM 87545. RP Forinash, K (reprint author), INDIANA UNIV SE,NEW ALBANY,IN 47150, USA. RI PEYRARD, Michel/C-8494-2014 NR 24 TC 34 Z9 34 U1 0 U2 2 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1063-651X J9 PHYS REV E JI Phys. Rev. E PD APR PY 1997 VL 55 IS 4 BP 4740 EP 4756 DI 10.1103/PhysRevE.55.4740 PG 17 WC Physics, Fluids & Plasmas; Physics, Mathematical SC Physics GA WV249 UT WOS:A1997WV24900114 ER PT J AU Cook, SR Hoffbauer, MA AF Cook, SR Hoffbauer, MA TI Absolute momentum transfer in gas-surface scattering SO PHYSICAL REVIEW E LA English DT Article AB Two new parameters called the reduced force coefficients are introduced that eliminate the singularity problems associated with the momentum accommodation coefficients and completely describe the macroscopic average momentum transfer to a surface by an incident gas. In addition, the reduced force coefficients can be used to determine the flux-weighted average velocity and translational energy of molecules scattered from a surface, and can be used to approximate the energy accommodation coefficient for many gas-surface interactions. The reduced force coefficients for molecular beams of H-2 and N-2 incident upon SiO2-coated Kapton and Z-93-coated aluminum were obtained using a specialized torsion balance to measure the magnitudes and directions of the forces exerted on the surfaces by the molecular beams. RP Cook, SR (reprint author), LOS ALAMOS NATL LAB,POB 1663,LOS ALAMOS,NM 87545, USA. NR 12 TC 7 Z9 7 U1 0 U2 1 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1063-651X J9 PHYS REV E JI Phys. Rev. E PD APR PY 1997 VL 55 IS 4 BP R3828 EP R3831 PG 4 WC Physics, Fluids & Plasmas; Physics, Mathematical SC Physics GA WV249 UT WOS:A1997WV24900008 ER PT J AU Gualtieri, A Norby, P Artioli, G Hanson, J AF Gualtieri, A Norby, P Artioli, G Hanson, J TI Kinetics of formation of zeolite Na-A [LTA] from natural kaolinites SO PHYSICS AND CHEMISTRY OF MINERALS LA English DT Article ID AUTOCATALYTIC NUCLEATION; CRYSTALLIZATION; POWDER; MODEL AB The kinetics and mechanism of hydrothermal formation of zeolite A from natural kaolinites have been studied using as starting materials two international kaolinite standards (KGa-1 and KGa-2 from Georgia, USA) exhibiting a different degree of stacking disorder. Precursors utilized for the synthesis were prepared by heating the kaolinites at 800 degrees C. Metakaolinite was also prepared from KGa-1 by thermal activation at 600 degrees C. The hydrothermal syntheses were accomplished by heating the samples in NaOH solutions at temperatures between 70 and 110 degrees C. The kinetic experiments were performed by time-resolved synchrotron powder diffraction in isothermal mode using a transmission geometry and an Image Plate detector. The results of the kinetic analysis are interpreted in the light of the structural state of the starting kaolinite, and of the temperature of activation of the precursor material. For kaolinite activated at high temperature the nucleation and crystallization of zeolite A is essentially independent of the defect density of the original kaolinite, and the thermal history of the precursor seems to be the main controlling parameter. The formation process of zeolite A from metakaolinite materials obtained at lower activation temperatures shows significantly faster reaction rates and lower apparent activation energies. This is again interpreted in the light of the short range inhomogeneities present in metakaolinite. As the reaction proceeds metastable zeolite A transforms into hydroxy-sodalite. C1 UNIV MILAN,DIPARTIMENTO SCI TERRA,I-20133 MILAN,ITALY. BROOKHAVEN NATL LAB,DEPT CHEM,UPTON,NY 11973. RI Hanson, jonathan/E-3517-2010; Artioli, Gilberto/F-2149-2015; Gualtieri, Alessandro/L-9680-2015; Norby, Poul/B-9047-2014 OI Artioli, Gilberto/0000-0002-8693-7392; Gualtieri, Alessandro/0000-0002-4414-9603; Norby, Poul/0000-0002-2590-7050 NR 38 TC 63 Z9 64 U1 1 U2 20 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 SN 0342-1791 J9 PHYS CHEM MINER JI Phys. Chem. Miner. PD APR PY 1997 VL 24 IS 3 BP 191 EP 199 DI 10.1007/s002690050032 PG 9 WC Materials Science, Multidisciplinary; Mineralogy SC Materials Science; Mineralogy GA WY175 UT WOS:A1997WY17500004 ER PT J AU Zhou, H AF Zhou, H TI On the motion of slender vortex filaments SO PHYSICS OF FLUIDS LA English DT Article ID 3 DIMENSIONS; INSTABILITY; TURBULENCE; RECURRENCE; VORTICITY; EQUATION; WAVES AB Several approaches for slender vortex motion (the local induction equation, the Klein-Majda equation, and the Klein-Knio equation) are compared on a specific example of sideband instability of Kelvin waves on a vortex. Numerical experiments on this model problem indicate that all these equations yield qualitatively similar behavior, and this behavior is different from the behavior of a nonslender vortex with variable cross-section. It is found that the boundaries between stable, recurrent, and chaotic regimes in the parameter space of the model problem depend on the equation used. The boundaries of these domains in the parameter space for the Klein-Majda equation and for the Klein-Knio equation are closely related to the core size. When the core size is large enough, the Klein-Majda equation always exhibits stable solutions for our model problem. Various conclusions are drawn; in particular, the behavior of turbulent vortices cannot be captured by these approximations, and probably cannot be captured by any slender vortex model with constant vortex cross-section. Speculations about the differences between classical and superfluid hydrodynamics are also offered. (C) 1997 American Institute of Physics. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,BERKELEY,CA 94720. RP Zhou, H (reprint author), UNIV CALIF BERKELEY,DEPT MATH,BERKELEY,CA 94720, USA. NR 36 TC 12 Z9 12 U1 0 U2 1 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 1070-6631 J9 PHYS FLUIDS JI Phys. Fluids PD APR PY 1997 VL 9 IS 4 BP 970 EP 981 DI 10.1063/1.869192 PG 12 WC Mechanics; Physics, Fluids & Plasmas SC Mechanics; Physics GA WQ094 UT WOS:A1997WQ09400017 ER PT J AU Cohen, RH Ryutov, DD AF Cohen, RH Ryutov, DD TI Beam-type instabilities of the sheath in a grazing magnetic field SO PHYSICS OF PLASMAS LA English DT Article ID HELMHOLTZ VORTEX FORMATION; PLASMA SHEATH; PARTICLE-TRANSPORT AB A plasma sheath in a strongly tilted magnetic field is considered. It is shown that, if the incoming plasma flux contains two ion populations with clearly distinguishable energies (e.g., an admixture of cold ions to the main ion distribution), vigorous beam-type instabilities may be excited in the sheath. One should emphasize that these instabilities may be present even if the ion distribution function in the bulk of the plasma does not have beam structure. (C) 1997 American Institute of Physics. C1 LAWRENCE LIVERMORE NATL LAB, LIVERMORE, CA 94551 USA. NR 10 TC 2 Z9 2 U1 1 U2 3 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 1070-664X J9 PHYS PLASMAS JI Phys. Plasmas PD APR PY 1997 VL 4 IS 4 BP 905 EP 907 DI 10.1063/1.872206 PG 3 WC Physics, Fluids & Plasmas SC Physics GA WU086 UT WOS:A1997WU08600001 ER PT J AU Cohen, BI Lasinski, BF Langdon, AB Williams, EA AF Cohen, BI Lasinski, BF Langdon, AB Williams, EA TI Resonantly excited nonlinear ion waves SO PHYSICS OF PLASMAS LA English DT Article ID STIMULATED BRILLOUIN-SCATTERING; LASER-IRRADIATED PLASMAS; ACOUSTIC-WAVES; BACKSCATTER; EVOLUTION; FREQUENCY; LIGHT; RAMAN; NOVA AB One- and two-dimensional simulations and supporting analysis of nonlinear ion acoustic waves as might be associated with the saturation of stimulated Brillouin backscattering (SBBS) are presented. To simulate ion wave phenomena efficiently, while retaining a fully kinetic representation of the ions, a Boltzmann fluid model is used for the electrons, and a particle-in-cell representation is used for the ions. Poisson's equation is solved in order to retain space-charge effects. We derive a new dispersion relation describing the parametric instability of ion waves, evidence for which is observed in our simulations. One- and two-dimensional simulations of plasma with either initially cold or warm ions (and multi-species ions) exhibit a complex interplay of phenomena that influence the time evolution and relaxation of the amplitude of the excited ion wave: ion trapping, wave steepening, acceleration, heating and tail formation in the ion velocity distribution, parametric decay into longer wavelength ion waves, modulational and filamentation instabilities, and induced scattering by ions. The additional degrees of freedom in two dimensions allow for a more rapid relaxation of the primary ion wave. One-dimensional electrostatic simulations with externally driven ion waves agree qualitatively with electromagnetic simulations in one dimension in which the ponderomotive driving potential is computed self-consistently by solving a Schroedinger-like equation for the electromagnetic waves and calculating the low-frequency ponderomotive force on the electrons. (C) 1997 American Institute of Physics. RP Cohen, BI (reprint author), LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550, USA. NR 43 TC 70 Z9 70 U1 0 U2 5 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 1070-664X J9 PHYS PLASMAS JI Phys. Plasmas PD APR PY 1997 VL 4 IS 4 BP 956 EP 977 DI 10.1063/1.872187 PG 22 WC Physics, Fluids & Plasmas SC Physics GA WU086 UT WOS:A1997WU08600008 ER PT J AU Smith, SA Hammett, GW AF Smith, SA Hammett, GW TI Eddy viscosity and hyperviscosity in spectral simulations of 2D drift wave turbulence SO PHYSICS OF PLASMAS LA English DT Article ID PARTICLE SIMULATION; TOKAMAK TURBULENCE; MODEL; DIMENSIONS AB A wavenumber dependent eddy viscosity is calculated for a simple two-dimensional drift wave model from direct numerical simulations for a wide range of parameters and cutoff wavenumber. The damping rate given by this eddy viscosity is well modeled by a hyperviscosity, where the power and magnitude are parameterized as functions of the shear in the resolved advecting velocity. Tests in simulations with low resolution find that the use of this parameterized hyperviscosity yields somewhat better results than the use of hyperviscosity with fixed power and is significantly better the use of no extra damping term or a Smagorinsky type eddy viscosity. This parameterized hyperviscosity is very useful computationally, since reducing resolution requirements by even a factor of 2 reduces the computational requirements by a factor of 8 in two dimensions, or 16 in three dimensions. (C) 1997 American Institute of Physics. C1 PRINCETON PLASMA PHYS LAB,PRINCETON,NJ 08543. RP Smith, SA (reprint author), PRINCETON UNIV,DEPT COMPUTAT & APPL MATH,PRINCETON,NJ 08544, USA. RI Hammett, Gregory/D-1365-2011 OI Hammett, Gregory/0000-0003-1495-6647 NR 31 TC 11 Z9 11 U1 0 U2 2 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 1070-664X J9 PHYS PLASMAS JI Phys. Plasmas PD APR PY 1997 VL 4 IS 4 BP 978 EP 990 DI 10.1063/1.872210 PG 13 WC Physics, Fluids & Plasmas SC Physics GA WU086 UT WOS:A1997WU08600009 ER PT J AU Miller, RL LinLiu, YR Turnbull, AD Chan, VS Pearlstein, LD Sauter, O Villard, L AF Miller, RL LinLiu, YR Turnbull, AD Chan, VS Pearlstein, LD Sauter, O Villard, L TI Stable equilibria for bootstrap-current-driven low aspect ratio tokamaks SO PHYSICS OF PLASMAS LA English DT Article ID STABILITY CODE; MHD STABILITY; DIII-D; SOLVER; MODES AB Low aspect ratio tokamaks (LATs) can potentially provide a high ratio of plasma pressure to magnetic pressure beta and high plasma current I at a modest size. This opens up the possibility of a high-power density compact fusion power plant. For the concept to be economically feasible, bootstrap current must be a major component of the plasma current, which requires operating at high beta(p). A high value of the Troyon factor beta(N) and strong shaping is required to allow simultaneous operation at a high-P and high bootstrap fraction. Ideal magnetohydrodynamic stability of a range of equilibria at aspect ratio 1.4 is systematically explored by varying the pressure profile and shape. The pressure and current profiles are constrained in such a way as to assure complete bootstrap current alignment. Both beta(N) and beta are defined in terms of the vacuum toroidal field. Equilibria with beta(N) greater than or equal to 8 and beta similar to 35%-55% exist that are stable to n=infinity ballooning modes. The highest beta case is shown to be stable to n=0,1,2,3 kink modes with a conducting wall. (C) 1997 American Institute of Physics. C1 LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94551. EURATOM,EPFL,CRPP,LAUSANNE,SWITZERLAND. RP Miller, RL (reprint author), GEN ATOM CO,SAN DIEGO,CA 92186, USA. NR 13 TC 108 Z9 109 U1 1 U2 3 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 1070-664X J9 PHYS PLASMAS JI Phys. Plasmas PD APR PY 1997 VL 4 IS 4 BP 1062 EP 1068 DI 10.1063/1.872193 PG 7 WC Physics, Fluids & Plasmas SC Physics GA WU086 UT WOS:A1997WU08600018 ER PT J AU Zarnstorff, MC Levinton, FM Batha, SH Synakowski, EJ AF Zarnstorff, MC Levinton, FM Batha, SH Synakowski, EJ TI The effect of E-r on motional-Stark effect measurements of q, a new technique for measuring E-r, and a test of the neoclassical E-r SO PHYSICS OF PLASMAS LA English DT Article ID FUSION TEST REACTOR; DIII-D; MAGNETIC RECONNECTION; TOKAMAK PLASMA; SAFETY FACTOR; TFTR; ROTATION; INTERFEROMETER; EQUILIBRIUM; TURBULENCE AB Previous analysis of motional-Stark Effect (MSE) data to measure the q-profile ignored contributions from the plasma electric field. The MSE measurements are shown to be sensitive to the electric field and require significant corrections for plasmas with large rotation velocities or pressure gradients. MSE measurements from rotating plasmas on the Tokamak Fusion Test Reactor (TFTR) [Phys. Plasmas 2, 2176 (1975)] confirm the significance of these corrections and verify their magnitude. Several attractive configurations are considered for future MSE-based diagnostics fdr measuring the plasma radial electric field. MSE data from TFTR are analyzed to determine the change in the radial electric field between two plasmas. The measured electric field quantitatively agrees with the predictions of neoclassical theory. These results confirm the utility of a MSE electric field measurement. (C) 1997 American Institute of Physics. C1 FUS PHYS & TECHNOL INC, TORRANCE, CA 90503 USA. RP Zarnstorff, MC (reprint author), PRINCETON UNIV, PRINCETON PLASMA PHYS LAB, PRINCETON, NJ 08543 USA. NR 35 TC 55 Z9 55 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 1070-664X J9 PHYS PLASMAS JI Phys. Plasmas PD APR PY 1997 VL 4 IS 4 BP 1097 EP 1102 DI 10.1063/1.872197 PG 6 WC Physics, Fluids & Plasmas SC Physics GA WU086 UT WOS:A1997WU08600022 ER PT J AU Zhao, Y White, RB AF Zhao, Y White, RB TI Simulation of alpha-particle redistribution due to sawteeth on the Tokamak Fusion Test Reactor SO PHYSICS OF PLASMAS LA English DT Article ID TFTR; TRANSPORT AB In recent deuterium-tritium experiments on the Tokamak Fusion Test Reactor (TFTR), both the pellet charge exchange (PCX) [Phys. Rev. Lett. 75, 846 (1995); Nucl. Fusion 35, 1437 (1995)] and the alpha charge exchange recombination spectroscopy (alpha-CHERS) [Phys. Rev. Lett. 75, 649 (1995)] diagnostics indicate that sav;tooth oscillations can cause significant broadening of the fusion alpha radial density profile. Investigation of this sawtooth mixing phenomenon was performed by applying a Hamiltonian guiding center approach. A model of time evolution of the Kadomtsev-type sawtooth [Sov. J. Plasma Phys. 1, 389 (1976)] is constructed. The presence of more than one mode in the nonlinear stage of the sawtooth crash is necessary to cause significant broadening of the alpha density profile. Use of numerical equilibria allows us to perform detailed comparisons with TFTR experimental data. The simulation results are in reasonable agreement with alpha-CHERS and show a broadening of alpha particles similar to that seen in PCX measurements. (C) 1997 American Institute of Physics. RP Zhao, Y (reprint author), PRINCETON PLASMA PHYS LAB,POB 451,PRINCETON,NJ 08543, USA. RI White, Roscoe/D-1773-2013 OI White, Roscoe/0000-0002-4239-2685 NR 15 TC 15 Z9 15 U1 0 U2 1 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 1070-664X J9 PHYS PLASMAS JI Phys. Plasmas PD APR PY 1997 VL 4 IS 4 BP 1103 EP 1109 DI 10.1063/1.872198 PG 7 WC Physics, Fluids & Plasmas SC Physics GA WU086 UT WOS:A1997WU08600023 ER PT J AU Whittum, DH AF Whittum, DH TI Transverse two-stream instability of a beam with a Bennett profile SO PHYSICS OF PLASMAS LA English DT Article ID RELATIVISTIC ELECTRON-BEAM; PLASMA WAKEFIELD ACCELERATOR; HOSE INSTABILITY; STABILITY AB A relativistic electron beam magnetically self-focused in a plasma is subject to an electrostatic hose instability. A linear theory of hose growth is formulated, taking into account nonlinear focusing of the beam and collisionless damping due to a plasma gradient. Theory is compared to particle-in-cell simulations of three-dimensional transport of a beam with a Bennett profile, through a broad uniform plasma, as well as a plasma channel matched to the beam. (C) 1997 American Institute of Physics. RP Whittum, DH (reprint author), STANFORD UNIV,STANFORD LINEAR ACCELERATOR CTR,STANFORD,CA 94309, USA. NR 28 TC 29 Z9 29 U1 1 U2 4 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 1070-664X J9 PHYS PLASMAS JI Phys. Plasmas PD APR PY 1997 VL 4 IS 4 BP 1154 EP 1159 DI 10.1063/1.872202 PG 6 WC Physics, Fluids & Plasmas SC Physics GA WU086 UT WOS:A1997WU08600030 ER PT J AU Rogers, BN Zakharov, L AF Rogers, BN Zakharov, L TI Collisionless m=1 reconnection in tokamaks - Reply SO PHYSICS OF PLASMAS LA English DT Article ID HIGH-TEMPERATURE PLASMAS; NONLINEAR DYNAMICS; INSTABILITY C1 PRINCETON PLASMA PHYS LAB,PRINCETON,NJ 08543. RP Rogers, BN (reprint author), UNIV MARYLAND,INST PLASMA RES,COLLEGE PK,MD 20742, USA. NR 8 TC 0 Z9 0 U1 1 U2 2 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 1070-664X J9 PHYS PLASMAS JI Phys. Plasmas PD APR PY 1997 VL 4 IS 4 BP 1175 EP 1175 DI 10.1063/1.872216 PG 1 WC Physics, Fluids & Plasmas SC Physics GA WU086 UT WOS:A1997WU08600036 ER PT J AU Ottaviani, M Beer, MA Cowley, SC Horton, W Krommes, JA AF Ottaviani, M Beer, MA Cowley, SC Horton, W Krommes, JA TI Unanswered questions in ion-temperature-gradient-driven turbulence SO PHYSICS REPORTS-REVIEW SECTION OF PHYSICS LETTERS LA English DT Article DE plasma; turbulence; transport; ITG; Tokamak ID LINEAR GYROKINETIC EQUATIONS; DRIFT MODES; TOKAMAK TURBULENCE; TOROIDAL GEOMETRY; RADIAL STRUCTURE; FLUID MODELS; PLASMA; SIMULATIONS; TRANSPORT; VORTICES AB In this work a number of open questions in the theory of ion-temperature-gradient-driven turbulence are considered. A simple model is introduced as a paradigm of more complex plasma turbulence models. Special emphasis is placed on those issues that are relevant for the understanding of turbulent transport. C1 PRINCETON UNIV,PLASMA PHYS LAB,PRINCETON,NJ 08543. UNIV CALIF LOS ANGELES,DEPT PHYS,LOS ANGELES,CA 90024. UNIV TEXAS,INST FUS STUDIES,AUSTIN,TX 78712. RP Ottaviani, M (reprint author), JET JOINT UNDERTAKING,ABINGDON OX14 3EA,OXON,ENGLAND. NR 69 TC 18 Z9 18 U1 1 U2 4 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0370-1573 J9 PHYS REP JI Phys. Rep.-Rev. Sec. Phys. Lett. PD APR PY 1997 VL 283 IS 1-4 BP 121 EP 146 DI 10.1016/S0370-1573(96)00056-7 PG 26 WC Physics, Multidisciplinary SC Physics GA XB809 UT WOS:A1997XB80900006 ER PT J AU Kulsrud, R Cowley, SC Gruzinov, AV Sudan, RN AF Kulsrud, R Cowley, SC Gruzinov, AV Sudan, RN TI Dynamos and cosmic magnetic fields SO PHYSICS REPORTS-REVIEW SECTION OF PHYSICS LETTERS LA English DT Article DE galaxy; protogalaxy; MHD dynamos; batteries ID ELECTRODYNAMICS AB This paper discusses the origin of the galactic magnetic field. The theory of the mean field dynamo in the interstellar medium is reviewed and shown to be flawed because it ignores the strong amplification of small-scale magnetic fields. An alternative origin is offered. It is proposed that the galactic fields are created in the protogalaxy by protogalactic turbulence. It is shown that they are first created from zero by the turbulence through the Biermann battery mechanism. The resulting weak seed fields are then amplified by the dynamo action of the protogalactic turbulence up to a field strength adequate for a primordial field origin of the galactic magnetic field. It is suggested that the amplification of the small-scale fields, that are a problem for the interstellar origin, are suppressed in the protogalaxy by collisionless processes that act on scales smaller than the mean free path. Since the relative size of the mean free path is quite large in the protogalaxy, the dynamo would generate only large-scale fields. After compression this held could become the galactic held. It is possible that no further amplification of it need occur in the interstellar medium. C1 PRINCETON UNIV,PLASMA PHYS LAB,PRINCETON,NJ 08544. UNIV CALIF LOS ANGELES,DEPT PHYS,LOS ANGELES,CA 90024. UNIV CALIF SAN DIEGO,DEPT PHYS,LA JOLLA,CA 92093. CORNELL UNIV,PLASMA STUDIES LAB,ITHACA,NY 14853. UNIV CALIF SANTA BARBARA,INST THEORET PHYS,SANTA BARBARA,CA 93106. RP Kulsrud, R (reprint author), PRINCETON UNIV,DEPT ASTROPHYS SCI,PRINCETON,NJ 08544, USA. NR 21 TC 31 Z9 31 U1 1 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0370-1573 J9 PHYS REP JI Phys. Rep.-Rev. Sec. Phys. Lett. PD APR PY 1997 VL 283 IS 1-4 BP 213 EP 226 DI 10.1016/S0370-1573(96)00061-0 PG 14 WC Physics, Multidisciplinary SC Physics GA XB809 UT WOS:A1997XB80900011 ER PT J AU Crabtree, GW Nelson, DR AF Crabtree, GW Nelson, DR TI Vortex physics in high-temperature superconductors SO PHYSICS TODAY LA English DT Article ID MELTING TRANSITION; LATTICE; ORDER; LINE; YBA2CU3O7-DELTA; STATE C1 HARVARD UNIV,CAMBRIDGE,MA 02138. RP Crabtree, GW (reprint author), ARGONNE NATL LAB,DIV MAT SCI,9700 S CASS AVE,ARGONNE,IL 60439, USA. NR 25 TC 170 Z9 170 U1 1 U2 18 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0031-9228 J9 PHYS TODAY JI Phys. Today PD APR PY 1997 VL 50 IS 4 BP 38 EP 45 DI 10.1063/1.881715 PG 8 WC Physics, Multidisciplinary SC Physics GA WQ799 UT WOS:A1997WQ79900009 ER PT J AU Panofsky, WKH AF Panofsky, WKH TI A physical heritage of the cold war: Excess weapons plutonium SO PHYSICS TODAY LA English DT Editorial Material RP Panofsky, WKH (reprint author), STANFORD LINEAR ACCELERATOR CTR,STANFORD,CA 94309, USA. NR 0 TC 2 Z9 2 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0031-9228 J9 PHYS TODAY JI Phys. Today PD APR PY 1997 VL 50 IS 4 BP 61 EP 62 DI 10.1063/1.881716 PG 2 WC Physics, Multidisciplinary SC Physics GA WQ799 UT WOS:A1997WQ79900016 ER PT J AU Canfield, EH Guenther, AH Rhodes, CE AF Canfield, EH Guenther, AH Rhodes, CE TI Walter Carl Beckham - Obituary SO PHYSICS TODAY LA English DT Item About an Individual C1 SANDIA NATL LABS,ALBUQUERQUE,NM 87185. USAF,PHILLIPS LAB,KIRTLAND AFB,NM 87117. RP Canfield, EH (reprint author), LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550, USA. NR 0 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 0031-9228 J9 PHYS TODAY JI Phys. Today PD APR PY 1997 VL 50 IS 4 BP 82 EP 82 DI 10.1063/1.881739 PG 1 WC Physics, Multidisciplinary SC Physics GA WQ799 UT WOS:A1997WQ79900019 ER PT J AU Masion, A Bertsch, PM AF Masion, A Bertsch, PM TI Aluminium speciation in the presence of wheat root cell walls: A wet chemical study SO PLANT CELL AND ENVIRONMENT LA English DT Article DE wheat (Triticum aestivum L); Al speciation; Al tolerance; cell wall; ferron ID TRITICUM-AESTIVUM L; X-RAY-SCATTERING; AL13 TRIDECAMERIC POLYCATION; ALUMINUM(III) SPECIATION; AL3+-CA2+ INTERACTIONS; SENSITIVE CULTIVARS; AQUEOUS-SOLUTIONS; ORGANIC-LIGANDS; CALCIUM-UPTAKE; EXCISED ROOTS AB Hydrolysis of Al3+ was performed in the presence of isolated root cell walls from a series of wheat cultivars (Triticum aestivum L.) known to have differential tolerance to Al contamination, Aluminium speciation was dependent on the cell wall concentration. At low cell wall concentrations, significant amounts of the very toxic Al-13 species were formed. At higher cell wall concentrations, formation of the tridecamer was hindered or completely inhibited. The sensitive wheat cultivars displayed a higher affinity for aluminium than the tolerant cultivars. A possible Al tolerance mechanism based on cell wall permeability is discussed. C1 UNIV GEORGIA, SAVANNAH RIVER ECOL LAB, DIV BIOGEOCHEM, AIKEN, SC 29802 USA. NR 49 TC 17 Z9 20 U1 0 U2 4 PU WILEY-BLACKWELL PI MALDEN PA COMMERCE PLACE, 350 MAIN ST, MALDEN 02148, MA USA SN 0140-7791 J9 PLANT CELL ENVIRON JI Plant Cell Environ. PD APR PY 1997 VL 20 IS 4 BP 504 EP 512 DI 10.1046/j.1365-3040.1997.d01-86.x PG 9 WC Plant Sciences SC Plant Sciences GA WT871 UT WOS:A1997WT87100009 ER PT J AU Cahoon, EB Coughlan, SJ Shanklin, J AF Cahoon, EB Coughlan, SJ Shanklin, J TI Characterization of a structurally and functionally diverged acyl-acyl carrier protein desaturase from milkweed seed SO PLANT MOLECULAR BIOLOGY LA English DT Article DE fatty acid desaturase; Asclepias syriaca ID CIS-VACCENIC ACID; THUNBERGIA-ALATA ENDOSPERM; HIGHER-PLANTS; TRANSGENIC TOBACCO; BIOSYNTHESIS; EXPRESSION; SAFFLOWER AB A cDNA for a structurally variant acyl-acyl carrier protein (ACP) desaturase was isolated from milkweed (Asclepias syriaca) seed, a tissue enriched in palmitoleic (16:1 Delta(9))* and cis-vaccenic (18:1 Delta(11)) acids. Extracts of Escherichia coli that express the milkweed cDNA catalyzed Delta(9) desaturation of acyl-ACP substrates, and the recombinant enzyme exhibited seven- to ten-fold greater specificity for palmitoyl (16:0)-ACP and 30-fold greater specificity for myristoyl (14:0)-ACP than did known Delta(9)-stearoyl (18:0)-ACP desaturases. Like other variant acyl-ACP desaturases reported to date, the milkweed enzyme contains fewer amino acids near its N-terminus compared to previously characterized Delta(9)-18:0-ACP desaturases. Based on the activity of an N-terminal deletion mutant of a Delta(9)-18:0-ACP desaturase, this structural feature likely does not account for differences in substrate specificities. C1 PIONEER HI BRED INT INC,DEPT BIOTECHNOL RES,JOHNSTON,IA 50131. RP Cahoon, EB (reprint author), BROOKHAVEN NATL LAB,DEPT BIOL,UPTON,NY 11973, USA. NR 26 TC 28 Z9 31 U1 2 U2 13 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0167-4412 J9 PLANT MOL BIOL JI Plant Mol.Biol. PD APR PY 1997 VL 33 IS 6 BP 1105 EP 1110 DI 10.1023/A:1005821007291 PG 6 WC Biochemistry & Molecular Biology; Plant Sciences SC Biochemistry & Molecular Biology; Plant Sciences GA WZ473 UT WOS:A1997WZ47300016 PM 9154992 ER PT J AU Bulanov, SV Vshivkov, VA Dudnikova, GI Naumova, NM Pegoraro, F Pogorelsky, IV AF Bulanov, SV Vshivkov, VA Dudnikova, GI Naumova, NM Pegoraro, F Pogorelsky, IV TI Laser acceleration of charged particles in inhomogeneous plasmas .1. SO PLASMA PHYSICS REPORTS LA English DT Article ID UNDERDENSE PLASMA; PULSE; WAVES; PROPAGATION; ULTRASHORT; ELECTRON AB The interaction of a laser pulse with a thin high-density plasma slab (foil) is proposed as a mechanism for producing laser pulses with the appropriate shape (sharp leading and/or rear edges). Such a pulse is optimum for the excitation of high-amplitude wake fields in underdense plasmas. It is shown (analytically and via particle-in-cell numerical simulations) that a phase-stable regime of unlimited particle acceleration can be realized in inhomogeneous plasmas. C1 INST COMPUTAT TECHNOL,NOVOSIBIRSK,RUSSIA. UNIV TURIN,DEPT THEORET PHYS,TURIN,ITALY. UNIV PISA,DEPT PHYS,I-56100 PISA,ITALY. BROOKHAVEN NATL LAB,UPTON,NY 11973. RP Bulanov, SV (reprint author), RUSSIAN ACAD SCI,INST GEN PHYS,UL VAVILOVA 38,MOSCOW 117942,RUSSIA. RI Bulanov, Sergei/A-1721-2013; OI Pegoraro, Francesco/0000-0002-7216-5491 NR 33 TC 25 Z9 25 U1 3 U2 6 PU MAIK NAUKA/INTERPERIODICA PUBL PI WOODBURY PA C/O AMERICAN INST PHYSICS, 500 SUNNYSIDE BLVD, MEMBER SUBSCRIBER SERVICES, WOODBURY, NY 11797-2999 SN 1063-780X J9 PLASMA PHYS REP JI Plasma Phys. Rep. PD APR PY 1997 VL 23 IS 4 BP 259 EP 269 PG 11 WC Physics, Fluids & Plasmas SC Physics GA WX511 UT WOS:A1997WX51100002 ER PT J AU Bonivert, WD Cushnie, G AF Bonivert, WD Cushnie, G TI The NMFRC - An interactive resource SO PLATING AND SURFACE FINISHING LA English DT News Item C1 CAI ENGN,OAKTON,VA 22124. RP Bonivert, WD (reprint author), SANDIA NATL LABS,M-S 9404,BOX 969,LIVERMORE,CA 94551, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER ELECTROPLATERS SOC INC PI ORLANDO PA 12644 RESEARCH PKWY, ORLANDO, FL 32826-3298 SN 0360-3164 J9 PLAT SURF FINISH JI Plat. Surf. Finish. PD APR PY 1997 VL 84 IS 4 BP 50 EP 51 PG 2 WC Metallurgy & Metallurgical Engineering; Materials Science, Coatings & Films SC Metallurgy & Metallurgical Engineering; Materials Science GA WR513 UT WOS:A1997WR51300012 ER PT J AU Wise, J Gillen, KT Clough, RL AF Wise, J Gillen, KT Clough, RL TI Quantitative model for the time development of diffusion-limited oxidation profiles SO POLYMER LA English DT Article DE diffusion-limited oxidation; ageing; profile ID THERMALLY AGED ELASTOMERS; OXYGEN DIFFUSION; POLYMERS; GASES AB We combine diffusion and kinetic expressions with chemical/mechanical property relationships to develop a complete, quantitative model with no arbitrarily adjustable parameters for the time development of diffusion-limited oxidation profiles. Excellent agreement between experimental and theoretical modulus profiles for two materials (a nitrile and a neoprene) confirms our understanding of diffusion-limited oxidation and its time and temperature dependencies. The simple assumption of no time dependencies in any of the model parameters is adequate for predictions relevant to elastomer service lifetimes. (C) 1997 Elsevier Science Ltd. C1 SANDIA NATL LABS,ALBUQUERQUE,NM 87185. NR 17 TC 90 Z9 90 U1 3 U2 24 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, OXON, ENGLAND OX5 1GB SN 0032-3861 J9 POLYMER JI Polymer PD APR PY 1997 VL 38 IS 8 BP 1929 EP 1944 DI 10.1016/S0032-3861(96)00716-1 PG 16 WC Polymer Science SC Polymer Science GA WP717 UT WOS:A1997WP71700017 ER PT J AU Volkow, ND Rosen, B Farde, L AF Volkow, ND Rosen, B Farde, L TI Imaging the living human brain: Magnetic resonance imaging and positron emission tomography SO PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA LA English DT Editorial Material ID SENSORY STIMULATION C1 SUNY STONY BROOK,DEPT PSYCHIAT,STONY BROOK,NY 11794. MASSACHUSETTS GEN HOSP,NMR CTR,CHARLESTOWN,MA 02129. KAROLINSKA INST,DEPT PSYCHIAT,S-17171 STOCKHOLM,SWEDEN. RP Volkow, ND (reprint author), BROOKHAVEN NATL LAB,DEPT MED,UPTON,NY 11973, USA. NR 7 TC 42 Z9 42 U1 0 U2 4 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 APR 1 PY 1997 VL 94 IS 7 BP 2787 EP 2788 DI 10.1073/pnas.94.7.2787 PG 2 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA WR930 UT WOS:A1997WR93000007 PM 9096295 ER PT J AU Feigenbaum, J Rudich, S Blaze, M McCurley, K AF Feigenbaum, J Rudich, S Blaze, M McCurley, K TI Security and privacy in the information economy SO PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA LA English DT Editorial Material C1 CARNEGIE MELLON UNIV,DEPT COMP SCI,PITTSBURGH,PA 15213. SANDIA NATL LABS,ALBUQUERQUE,NM 87185. RP Feigenbaum, J (reprint author), AT&T BELL LABS,MURRAY HILL,NJ 07974, USA. NR 10 TC 1 Z9 1 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 APR 1 PY 1997 VL 94 IS 7 BP 2789 EP 2792 DI 10.1073/pnas.94.7.2789 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA WR930 UT WOS:A1997WR93000008 PM 11607726 ER PT J AU Shanklin, J Achim, C Schmidt, H Fox, BG Munck, E AF Shanklin, J Achim, C Schmidt, H Fox, BG Munck, E TI Mossbauer studies of alkane omega-hydroxylase: Evidence for a diiron cluster in an integral-membrane enzyme SO PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA LA English DT Article DE nonheme; oxygenase; desaturase; binuclear iron; cytochrome P450 ID METHYLOSINUS-TRICHOSPORIUM OB3B; SOLUBLE METHANE MONOOXYGENASE; PSEUDOMONAS-OLEOVORANS; ESCHERICHIA-COLI; RIBONUCLEOTIDE REDUCTASE; PROTEIN; OXO; DESATURASE; OXIDATION; EPOXIDATION AB The gene encoding the alkane omega-hydroxylase (AlkB; EC 1.14.15.3) from Pseudomonas oleovorans was expressed in Escherichia coli, The integral-membrane protein was purified as nearly homogeneous protein vesicles by differential ultracentrifugation and HPLC cation exchange chromatography without the detergent solubilization normally required for membrane proteins, Purified AlkB had specific activity of up to 5 units/mg for octane-dependent NADPH consumption, Mossbauer studies of AlkB showed that it contains an exchange-coupled dinuclear iron cluster of the type found in soluble diiron proteins such as hemerythrin, ribonucleotide reductase, methane monooxygenase, stearoyl-acyl carrier protein (ACP) Delta(9) desaturase, rubrerythrin, and purple acid phosphatase, In the as-isolated enzyme, the cluster contains an antiferromagnetically coupled pair of high-spin Fe(lII) sites, with an occupancy of up to 0.9 cluster per AlkB, The diferric cluster could be reduced by sodium dithionite, and the diferrous state was found to be stable in air, When both O-2 and substrate (octane) were added, however, the diferrous cluster was quantitatively reoxidized, proving that the diiron cluster occupies the active site, Mossbauer data on reduced AlkB are consistent with a cluster coordination rich in nitrogen-containing ligands, New sequence analyses indicate that at least 11 nonheme integral-membrane enzymes, including AlkB, contain the 8-histidine motif required for catalytic activity in stearoyl-CoA desaturase, Based on our Mossbauer studies of AlkB, we propose that the integral-membrane enzymes in this family contain diiron clusters, Because these enzymes catalyze a diverse range of oxygenation reactions, this proposal suggests a greatly expanded role for diiron clusters in O-2-activation biochemistry. C1 UNIV WISCONSIN,INST ENZYME RES,MADISON,WI 53705. CARNEGIE MELLON UNIV,DEPT CHEM,PITTSBURGH,PA 15213. RP Shanklin, J (reprint author), BROOKHAVEN NATL LAB,DEPT BIOL,UPTON,NY 11973, USA. RI Achim, Catalina/B-1062-2015 OI Achim, Catalina/0000-0001-5420-4656 FU NIGMS NIH HHS [GM-22701, GM-50853, R01 GM050853] NR 37 TC 146 Z9 148 U1 6 U2 23 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 APR 1 PY 1997 VL 94 IS 7 BP 2981 EP 2986 DI 10.1073/pnas.94.7.2981 PG 6 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA WR930 UT WOS:A1997WR93000044 PM 9096332 ER PT J AU Hagen, TM Yowe, DL Bartholomew, JC Wehr, CM Do, KL Park, JY Ames, BN AF Hagen, TM Yowe, DL Bartholomew, JC Wehr, CM Do, KL Park, JY Ames, BN TI Mitochondrial decay in hepatocytes from old rats: Membrane potential declines, heterogeneity and oxidants increase SO PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA LA English DT Article DE flow cytometry; aging; rhodamine 123; centrifugal cell elutriation; mitochondrial DNA deletions ID OXIDATIVE DAMAGE; HUMAN-FIBROBLASTS; DNA; CELLS; RHODAMINE-123; CARDIOLIPINS; DISEASE; BRAIN AB Mitochondrial function during aging was assessed in isolated rat hepatocytes to avoid the problem of differential lysis when old, fragile mitochondria are isolated, Rhodamine 123, a fluorescent dye that accumulates in mitochondria on the basis of their membrane potential, was used as a probe to determine whether this key function is affected by aging. A marked fluorescent heterogeneity was observed in hepatocytes from old (20-28 months) but not young (3-5 months) rats, suggesting age-associated alterations in mitochondrial membrane potential, the driving force for,lTP synthesis, Three distinct cell subpopulations were separated by centrifugal elutriation; each exhibited a unique rhodamine 123 fluorescence pattern, with the largest population from old rats having significantly lower fluorescence than that seen in young rats. This apparent age-associated alteration in mitochondrial membrane potential was confirmed by measurements with radioactive tetraphenylphosphonium bromide. Cells from young rats had a calculated membrane potential of - 154 mV, in cent rast to that of the three subpopulations from old rats of -70 mV (the largest population), -93 mV, and - 154 mV, Production of oxidants was examined using 2',7'-dichlorofluorescin, a dye that forms a fluorescent product upon oxidation. The largest cell subpopulation and a minor one from old animals produced significantly more oxidants than cells from young rats. To investigate the molecular cause(s) for the heterogeneity, we determined tile levels of an age-associated mtDNA deletion, No significant differences were seen in the three subpopulations, Indicating that the mitochondrial decay is due to other mutations, epigenetic changes, or both. C1 UNIV CALIF BERKELEY,DIV BIOCHEM & MOL BIOL,BERKELEY,CA 94720. UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,BERKELEY,CA 94720. FU NCI NIH HHS [CA39910]; NIEHS NIH HHS [ES01896, P30 ES001896] NR 35 TC 329 Z9 340 U1 2 U2 9 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 APR 1 PY 1997 VL 94 IS 7 BP 3064 EP 3069 DI 10.1073/pnas.94.7.3064 PG 6 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA WR930 UT WOS:A1997WR93000058 PM 9096346 ER PT J AU Nouspikel, T Lalle, P Leadon, SA Cooper, PK Clarkson, SG AF Nouspikel, T Lalle, P Leadon, SA Cooper, PK Clarkson, SG TI A common mutational pattern in Cockayne syndrome patients from xeroderma pigmentosum group G: Implications for a second XPG function SO PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA LA English DT Article DE transcription-coupled repair; nucleotide excision repair; UV irradiation ID NUCLEOTIDE EXCISION-REPAIR; RNA-POLYMERASE-II; COMPLEMENTATION GROUP-D; DNA-REPAIR; SACCHAROMYCES-CEREVISIAE; TRANSCRIPTION FACTOR; PREFERENTIAL REPAIR; IONIZING-RADIATION; SCHIZOSACCHAROMYCES-POMBE; ACTIVE GENES AB Xeroderma pigmentosum (XP) patients have defects in nucleotide excision repair (NER), the versatile repair pathway that removes UV-induced damage and other bulky DNA adducts, patients with Cockayne syndrome (CS), another rare sun-sensitive disorder, are specifically defective in the preferential removal of damage from the transcribed strand of active genes, a process known as transcription-coupled repair, These two disorders are usually clinically and genetically distinct, but complementation analyses have assigned a few CS patients to the rare XP groups B, D, or G, The XPG gene encodes a structure-specific endonuclease that nicks damaged DNA 3' to the lesion during NER, Here we show that three XPG/CS patients had mutations that would produce severely truncated XPG proteins, In contrast, two sibling XPG patients without CS are able to make full-length XPG, but with a missense mutation that inactivates its function in NER, These results suggest that XPG/CS mutations abolish interactions required for a second important XPG function and that it is the loss of this second function that leads to the CS clinical phenotype. C1 UNIV GENEVA,MED CTR,CMU,DEPT GENET & MICROBIOL,CH-1211 GENEVA 4,SWITZERLAND. UNIV N CAROLINA,SCH MED,DEPT RADIAT ONCOL,CHAPEL HILL,NC 27599. UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV LIFE SCI,BERKELEY,CA 94720. FU NCI NIH HHS [R01 CA040453, R01 CA063503] NR 59 TC 128 Z9 130 U1 0 U2 6 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 APR 1 PY 1997 VL 94 IS 7 BP 3116 EP 3121 DI 10.1073/pnas.94.7.3116 PG 6 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA WR930 UT WOS:A1997WR93000067 PM 9096355 ER PT J AU Seegers, JC deKock, M Lottering, ML Grobler, CJS vanPapendorp, DH Shou, Y Habbersett, R Lehnert, BE AF Seegers, JC deKock, M Lottering, ML Grobler, CJS vanPapendorp, DH Shou, Y Habbersett, R Lehnert, BE TI Effects of gamma-linolenic acid and arachidonic acid on cell cycle progression and apoptosis induction in normal and transformed cells SO PROSTAGLANDINS LEUKOTRIENES AND ESSENTIAL FATTY ACIDS LA English DT Article ID TUMOR-NECROSIS-FACTOR; UNSATURATED FATTY-ACIDS; CANCER-CELLS; FACTOR-ALPHA; GROWTH; PROTEIN; LINES; DEATH; P53; LYMPHOCYTES AB The effects of arachidonic acid (AA) and gamma-linolenic acid (GLA) on cell cycle progression and apoptosis induction, using flow cytometry, were compared on normal human skin fibroblasts, strain HSF43 with wild type (wt) p53, large T antigen transformed HSF43 cells (line E8T4) with non functional p53, and on two lymphoblast cell lines, TK6 with wt p53 and WTK1 with mutant p53. AA and GLA caused similar dose (50, 75 and 100 mu g/ml AA and GLA) and time dependent (24 and 48 h) induction of apoptosis in each cell line. The degrees of the response of the four cell lines were, however, different. The normal HSF43 cells were most resistant against apoptosis induction and the WTK1 cells most susceptible. The apoptosis induction appeared to be independent of functional p53. Cell cycle progression was also similarly affected by AA and GLA in the two cell types. In the fibroblast type cells (HSF43 and E8T4) S- and G(2)/M-phase arrests were evident after 48 h exposure to AA and GLA, and in the lymphoblast cell lines (TK6 and WTK1) the cells were arrested in the G(1)-phase. C1 LOS ALAMOS NATL LAB,DIV LIFE SCI,LOS ALAMOS,NM. RP Seegers, JC (reprint author), UNIV PRETORIA,DEPT PHYSIOL,POB 2034,ZA-0001 PRETORIA,SOUTH AFRICA. NR 34 TC 38 Z9 38 U1 0 U2 1 PU CHURCHILL LIVINGSTONE PI EDINBURGH PA JOURNAL PRODUCTION DEPT, ROBERT STEVENSON HOUSE, 1-3 BAXTERS PLACE, LEITH WALK, EDINBURGH EH1 3AF, MIDLOTHIAN, SCOTLAND SN 0952-3278 J9 PROSTAG LEUKOTR ESS JI Prostaglandins Leukot. Essent. Fatty Acids PD APR PY 1997 VL 56 IS 4 BP 271 EP 280 DI 10.1016/S0952-3278(97)90570-6 PG 10 WC Biochemistry & Molecular Biology; Cell Biology; Endocrinology & Metabolism SC Biochemistry & Molecular Biology; Cell Biology; Endocrinology & Metabolism GA WW512 UT WOS:A1997WW51200004 PM 9150372 ER PT J AU Su, SY Gao, YG Zhang, H Terwilliger, TC Wang, AHJ AF Su, SY Gao, YG Zhang, H Terwilliger, TC Wang, AHJ TI Analyses of the stability and function of three surface mutants (R82C, K69H, and L32R) of the gene V protein from Ff phage by x-ray crystallography SO PROTEIN SCIENCE LA English DT Article DE electrostatics; molecular modeling; protein-DNA interactions; single-stranded DNA-binding protein; X-ray crystallography ID SINGLE-STRANDED-DNA; GVP-SSDNA COMPLEX; BINDING-PROTEIN; BACTERIOPHAGE M13; H-1-NMR; MODEL; ACID; SCATTERING AB The high-resolution crystal structure of the gene V protein (GVP) from the Ff filamentous phages (M13, fl, fd) has been solved recently for the wild-type and two surface mutant (Y41F and Y41H) proteins, leading to a plausible model for the polymeric GVP-ssDNA complex (Guan Y, Zhang H, Wang AHJ, 1995, Protein Sci 4:187-197). The model of the complex shows extensive contacts between neighboring dimer GVPs involving electrostatic interactions between the K69 from one and the D79 and R82 from the next dimer. In addition, hydrophobic interactions between the amino acids L32 and L44 from one and G23 from the next dimer also contribute to the dimer-dimer interactions. Mutations at the L32, K69, and R82 amino acid sites generally destabilize the protein and many of these affect the function of the phage. We have studied the structural effects of three mutant proteins involving those sites, i.e., L32R, K69H, and R82C, by X-ray crystallographic analysis at 2.0 Angstrom resolution. In L32R GVP, the structural perturbation is localized, whereas in K69H and R82C GVPs, some long-range effects are also detected in addition to the local perturbation. We have interpreted the protein stability and the functional properties associated with those mutations in terms of the observed structural perturbations. C1 UNIV ILLINOIS,DEPT CELL & STRUCT BIOL,URBANA,IL 61801. LOS ALAMOS NATL LAB,STRUCT BIOL GRP,LOS ALAMOS,NM 87545. RI Terwilliger, Thomas/K-4109-2012 OI Terwilliger, Thomas/0000-0001-6384-0320 FU NIGMS NIH HHS [GM-38714, GM-41612] NR 25 TC 9 Z9 9 U1 0 U2 0 PU CAMBRIDGE UNIV PRESS PI NEW YORK PA 40 WEST 20TH STREET, NEW YORK, NY 10011-4211 SN 0961-8368 J9 PROTEIN SCI JI Protein Sci. PD APR PY 1997 VL 6 IS 4 BP 771 EP 780 PG 10 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA WR779 UT WOS:A1997WR77900003 PM 9098886 ER PT J AU Garcia, AE Hummer, G Soumpasis, DM AF Garcia, AE Hummer, G Soumpasis, DM TI Hydration of an alpha-helical peptide: Comparison of theory and molecular dynamics simulation SO PROTEINS-STRUCTURE FUNCTION AND BIOINFORMATICS LA English DT Article DE protein hydration; potentials-of-mean-force; hydrophilic hydration; hydrophobic hydration ID MODEL PROTEIN HELIX; OF-MEAN-FORCE; WATER-MOLECULES; B-DNA; BIOLOGICAL MACROMOLECULES; SECONDARY STRUCTURE; COMPUTATION; TRANSITION; RESIDUES; DISTRIBUTIONS AB We present a statistical mechanical description of biomolecular hydration that accurately describes the hydrophobic and hydrophilic hydration of a model alpha-helical peptide, The local density of water molecules around a biomolecule is obtained by means of a potential-of-mean-force (PMF) expansion in terms of pair- and triplet-correlation functions of bulk water and dilute solutions of nonpolar atoms. The accuracy of the method is verified by comparing PMF results with the local density and site-site correlation functions obtained by molecular dynamics simulations of a model alpha-helix in solution. The PMF approach quantitatively reproduces all features of the peptide hydration determined from the molecular dynamics simulation. Regions of hydrophobic hydration near the C-alpha and C-beta atoms along the helix are well reproduced. The hydration of exposed polar groups at the N and C-termini of the helix are also well described by the theory. A detailed comparison of the local hydration by means of site-site radial distribution functions evaluated with the PMF theory shows agreement with the molecular dynamics simulations. The formulation of this theory is general and can be applied to any biomolecular system. The accuracy, speed of computation, and local character of this theory make it especially suitable for studying large biomolecular systems. (C) 1997 Wiley-Liss, Inc. C1 MAX PLANCK INST BIOPHYS CHEM, DEPT MOL BIOL, BIOCOMPUTAT GRP, D-37077 GOTTINGEN, GERMANY. RP LOS ALAMOS NATL LAB, THEORET BIOL & BIOPHYS GRP, MS K710, LOS ALAMOS, NM 87545 USA. RI Hummer, Gerhard/A-2546-2013 OI Hummer, Gerhard/0000-0001-7768-746X NR 57 TC 35 Z9 35 U1 0 U2 6 PU WILEY-BLACKWELL PI HOBOKEN PA 111 RIVER ST, HOBOKEN 07030-5774, NJ USA SN 0887-3585 EI 1097-0134 J9 PROTEINS JI Proteins PD APR PY 1997 VL 27 IS 4 BP 471 EP 480 DI 10.1002/(SICI)1097-0134(199704)27:4<471::AID-PROT1>3.3.CO;2-C PG 10 WC Biochemistry & Molecular Biology; Biophysics SC Biochemistry & Molecular Biology; Biophysics GA WW648 UT WOS:A1997WW64800001 PM 9141128 ER PT J AU Gruen, D Krauss, A AF Gruen, D Krauss, A TI Buckyball precursors produce ultra-smooth diamond films SO R&D MAGAZINE LA English DT Article RP Gruen, D (reprint author), ARGONNE NATL LAB,ARGONNE,IL 60439, USA. NR 0 TC 1 Z9 1 U1 0 U2 0 PU CAHNERS-DENVER PUBLISHING CO PI HIGHLANDS RANCH PA 8773 S RIDGELINE BLVD, HIGHLANDS RANCH, CO 80126-2329 SN 0746-9179 J9 R&D MAG JI R D Mag. PD APR PY 1997 VL 39 IS 5 BP 57 EP & PG 3 WC Engineering, Industrial; Multidisciplinary Sciences SC Engineering; Science & Technology - Other Topics GA WQ963 UT WOS:A1997WQ96300016 ER PT J AU Martz, HF Almond, RG AF Martz, HF Almond, RG TI Using higher-level failure data in fault tree quantification SO RELIABILITY ENGINEERING & SYSTEM SAFETY LA English DT Article ID BAYESIAN-ESTIMATION; PERFECT AGGREGATION; RELIABILITY; SUBSYSTEMS; DEPENDENCE; MODELS AB This paper presents a Bayesian method which can simultaneously combine basic event and statistically independent higher event-level failure data in fault tree quantification. Such higher-level data could correspond to train, subsystem or system failure events. In fact, because highest-level data are usually available for existing facilities, the method presented here allows such data to be propagated to lower levels. The method has two stages: (1) a top-down propagation scheme which allocates the higher event-level information to the basic events, at a cost of making them dependent; and (2) a scheme for sampling the probabilities of the dependent basic events. A simple example illustrates the performance of the method. (C) 1997 Elsevier Science Limited. C1 EDUC TESTING SERV,PRINCETON,NJ 08541. RP Martz, HF (reprint author), LOS ALAMOS NATL LAB,TECHNOL & SAFETY ASSESSMENT DIV,POB 1663,LOS ALAMOS,NM 87545, USA. NR 23 TC 7 Z9 7 U1 1 U2 2 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, OXON, ENGLAND OX5 1GB SN 0951-8320 J9 RELIAB ENG SYST SAFE JI Reliab. Eng. Syst. Saf. PD APR PY 1997 VL 56 IS 1 BP 29 EP 42 DI 10.1016/S0951-8320(96)00134-2 PG 14 WC Engineering, Industrial; Operations Research & Management Science SC Engineering; Operations Research & Management Science GA WW518 UT WOS:A1997WW51800004 ER PT J AU Hsu, CW Evans, M Ng, CY Heimann, P AF Hsu, CW Evans, M Ng, CY Heimann, P TI High resolution threshold and pulsed field ionization photoelectron spectroscopy using multi-bunch synchrotron radiation SO REVIEW OF SCIENTIFIC INSTRUMENTS LA English DT Article ID MOLECULAR-OXYGEN; SPECTRUM; ENERGY AB We have demonstrated a resolution of 0.8 meV [full width at half-maximum (FWHM)] for threshold photoelectron measurements using a steradiancy-type zero kinetic energy photoelectron (ZEKE-PE) analyzer and the high resolution monochromatized vacuum ultraviolet (VUV) undulator synchrotron radiation of the chemical dynamics beamline at the advanced light source (ALS). Using this high resolution ZEKE-FE energy analyzer to filter prompt electrons and by employing a proper voltage pulsing scheme adapted to the timing structure of the ALS, we have achieved a resolution of 0.5 meV (FWHM) for pulsed field ionization photoelectron (PFI-PE) measurements with little contamination from prompt photoelectrons produced from direct photoionization and autoionizing processes. The experiment scheme presented hen is generally applicable to PFI-PE studies using multi-bunch VUV synchrotron radiation at other synchrotron radiation facilities. (C) 1997 American Institute of Physics. C1 IOWA STATE UNIV,AMES LAB,US DEPT ENERGY,AMES,IA 50011. UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV CHEM SCI,BERKELEY,CA 94720. UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,FUS RES DIV,BERKELEY,CA 94720. IOWA STATE UNIV,DEPT CHEM,AMES,IA 50011. NR 49 TC 70 Z9 73 U1 0 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 APR PY 1997 VL 68 IS 4 BP 1694 EP 1702 DI 10.1063/1.1147977 PG 9 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA WV617 UT WOS:A1997WV61700009 ER PT J AU Moody, JD MacGowan, BJ Kirkwood, RK Montgomery, DS AF Moody, JD MacGowan, BJ Kirkwood, RK Montgomery, DS TI Measurements of high intensity laser beam transmission through a large scalelength plasma SO REVIEW OF SCIENTIFIC INSTRUMENTS LA English DT Article AB We describe an instrument used to measure the light transmitted through a large scalelength plasma. Light that passes through the plasma scatters diffusely from a frosted silica scatter plate. An optical system images this scattered light onto several detectors which measure its spatial and temporal characteristics. Low and high dispersion spectral measurements of the transmitted light are made using optical fiber collectors placed behind the scatter plate. (C) 1997 American Institute of Physics. C1 UNIV CALIF LAWRENCE LIVERMORE NATL LAB, LIVERMORE, CA 94551 USA. RP Moody, JD (reprint author), UNIV CALIF LAWRENCE LIVERMORE NATL LAB, LIVERMORE, CA 94551 USA. OI Montgomery, David/0000-0002-2355-6242 NR 4 TC 13 Z9 13 U1 0 U2 2 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0034-6748 EI 1089-7623 J9 REV SCI INSTRUM JI Rev. Sci. Instrum. PD APR PY 1997 VL 68 IS 4 BP 1725 EP 1729 DI 10.1063/1.1147981 PG 5 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA WV617 UT WOS:A1997WV61700014 ER PT J AU Pilgrim, JS Jennings, RT Taatjes, CA AF Pilgrim, JS Jennings, RT Taatjes, CA TI Temperature controlled multiple pass absorption cell for gas phase chemical kinetics studies SO REVIEW OF SCIENTIFIC INSTRUMENTS LA English DT Article AB The application of a Herriott-type optical multiple pass cell for absorption detection of transient species in temperature controlled laser pump-probe kinetics experiments is described. Using reaction initiation by laser photolysis in combination with reaction monitoring by absorption of a multiple pass laser allows confinement of the probed reaction volume to the temperature controlled region of a slow flow reactor. For transient measurements, this apparatus provides enhanced sensitivity from increased path length and accurate temperature control by limiting the pump-probe interaction volume. In addition, for a polarized probe laser, a simple arrangement using a polarizing beam splitter and a lambda/4 plate allows doubling of the path length. (C) 1997 American Institute of Physics. C1 SANDIA NATL LABS,COMBUST RES FACIL,LIVERMORE,CA 94551. NR 6 TC 44 Z9 44 U1 2 U2 10 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 APR PY 1997 VL 68 IS 4 BP 1875 EP 1878 DI 10.1063/1.1147960 PG 4 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA WV617 UT WOS:A1997WV61700045 ER PT J AU Lidsey, JE Liddle, AR Kold, EW Copeland, EJ Barreiro, T Abney, M AF Lidsey, JE Liddle, AR Kold, EW Copeland, EJ Barreiro, T Abney, M TI Reconstructing the inflaton potential - An overview SO REVIEWS OF MODERN PHYSICS LA English DT Review ID PRIMORDIAL BLACK-HOLES; MICROWAVE BACKGROUND ANISOTROPIES; INFLATIONARY UNIVERSE SCENARIO; BLUE PERTURBATION SPECTRA; BIG-BANG NUCLEOSYNTHESIS; EINSTEIN-HILBERT ACTION; LARGE-SCALE STRUCTURE; GRAVITATIONAL-WAVES; DARK-MATTER; COSMOLOGICAL PERTURBATIONS AB The authors review the relation between the inflationary potential and the spectra of density waves (scalar perturbations) and gravitational waves (tensor perturbations) produced, with particular emphasis on the possibility of reconstructing the inflaton potential from observations. The spectra provide a potentially powerful test of the inflationary hypothesis; they are not independent but instead are linked by consistency relations reflecting their origin from a single inflationary potential. To lowest order in a perturbation expansion there is a single, now familiar, relation between the tensor spectral index and the relative amplitude of the spectra. The authors demonstrate that there is an infinite hierarchy of such consistency equations, though observational difficulties suggest only the first is ever likely to be useful. They also note that since observations are expected to yield much better information on the scalars than on the tensors, it is likely to be the next-order version of this consistency equation that will be appropriate, not the lowest-order one. If inflation passes the consistency test, one can then confidently use the remaining observational information to constrain the inflationary potential, and the authors survey the general perturbative scheme for carrying out this procedure. Explicit expressions valid to next-lowest order in the expansion are presented. The prospects for future observations' reaching the quality required are then briefly assessed and simulated data sets motivated by this outlook are considered. C1 UNIV SUSSEX, CTR ASTRON, BRIGHTON BN1 9QH, E SUSSEX, ENGLAND. FERMILAB NATL ACCELERATOR LAB, NASA, FERMILAB ASTROPHYS CTR, BATAVIA, IL 60510 USA. UNIV CHICAGO, ENRICO FERMI INST, DEPT ASTRON & ASTROPHYS, CHICAGO, IL 60637 USA. UNIV SUSSEX, CTR THEORET PHYS, BRIGHTON BN1 9QH, E SUSSEX, ENGLAND. RP UNIV LONDON QUEEN MARY & WESTFIELD COLL, SCH MATH SCI, ASTRON UNIT, MILE END RD, LONDON E1 4NS, ENGLAND. OI Barreiro, Tiago/0000-0001-8542-2066 NR 208 TC 520 Z9 520 U1 0 U2 13 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0034-6861 EI 1539-0756 J9 REV MOD PHYS JI Rev. Mod. Phys. PD APR PY 1997 VL 69 IS 2 BP 373 EP 410 DI 10.1103/RevModPhys.69.373 PG 38 WC Physics, Multidisciplinary SC Physics GA WU345 UT WOS:A1997WU34500002 ER PT J AU Mills, WB Cheng, JJ Droppo, JG Faillace, ER Gnanapragasam, EK Johns, RA Laniak, GF Lew, CS Strenge, DL Sutherland, JF Whelan, G Yu, C AF Mills, WB Cheng, JJ Droppo, JG Faillace, ER Gnanapragasam, EK Johns, RA Laniak, GF Lew, CS Strenge, DL Sutherland, JF Whelan, G Yu, C TI Multimedia benchmarking analysis for three risk assessment models: RESRAD, MMSOILS, and MEPAS SO RISK ANALYSIS LA English DT Article DE multimedia; modeling; benchmarking; human health risk AB This paper is one in a series that describes results of a benchmarking analysis initiated by the Department of Energy (DOE) and the United States Environmental Protection Agency (EPA). An overview of the study is provided in a companion paper by Laniak et al. presented in this journal issue. The three models used in the study-RESRAD (DOE), MMSOILS (EPA), and MEPAS (DOE)-represent analytically-based tools that are used by the respective agencies for performing human exposure and health risk assessments. Both single media and multimedia benchmarking scenarios were developed and executed. in this paper, the multimedia scenario is examined. That scenario consists of a hypothetical landfill that initially contained uranium-238 and methylene chloride. The multimedia models predict the fate of these contaminants, plus the progeny of manium-238, through the unsaturated zone, saturated zone, surface water, and atmosphere. Carcinogenic risks are calculated from exposure to the contaminants via multiple pathways. Results of the tests show that differences in model endpoint estimates arise from both differences in the models' mathematical formulations and assumptions related to the implementation of the scenarios. C1 ARGONNE NATL LAB,ARGONNE,IL 60439. PACIFIC NW NATL LAB,RICHLAND,WA. US EPA,ATHENS,GA. UNIV TENNESSEE,KNOXVILLE,TN. RP Mills, WB (reprint author), TETRA TECH INC,LAFAYETTE,CA, USA. NR 21 TC 20 Z9 20 U1 0 U2 1 PU PLENUM PUBL CORP PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 SN 0272-4332 J9 RISK ANAL JI Risk Anal. PD APR PY 1997 VL 17 IS 2 BP 187 EP 201 DI 10.1111/j.1539-6924.1997.tb00858.x PG 15 WC Public, Environmental & Occupational Health; Mathematics, Interdisciplinary Applications; Social Sciences, Mathematical Methods SC Public, Environmental & Occupational Health; Mathematics; Mathematical Methods In Social Sciences GA XF221 UT WOS:A1997XF22100008 PM 9202488 ER PT J AU Laniak, GF Droppo, JG Faillace, ER Gnanapragasam, EK Mills, WB Strenge, DL Whelan, G Yu, C AF Laniak, GF Droppo, JG Faillace, ER Gnanapragasam, EK Mills, WB Strenge, DL Whelan, G Yu, C TI An overview of a multimedia benchmarking analysis for three risk assessment models: RESRAD, MMSOILS, and MEPAS SO RISK ANALYSIS LA English DT Article DE benchmarking; model comparison; multimedia modeling; multipathway analysis AB Multimedia modelers from the United States Environmental Protection Agency (EPA) and the United States Department of Energy (DOE) collaborated to conduct a detailed and quantitative benchmarking analysis of three multimedia models. The three models-RESRAD (DOE), MMSOILS (EPA), and MEPAS (DOE)--represent analytically-based tools that are used by the respective agencies for performing human exposure and health risk assessments. The study is performed by individuals who participate directly in the ongoing design, development, and application of the models. Model form and function are compared by applying the models to a series of hypothetical problems, first isolating individual modules (e.g., atmospheric, surface water, groundwater) and then simulating multimedia-based risk resulting from contaminant release from a single source to multiple environmental media. Study results show that the models differ with respect to environmental processes included (i.e., model features) and the mathematical formulation and assumptions related to the implementation of solutions. Depending on the application, numerical estimates resulting from the models may vary over several orders-of-magnitude. On the other hand, two or more differences may offset each other such that model predictions are virtually equal. The conclusion from these results is that multimedia models are complex due to the integration of the many components of a risk assessment and this complexity must be fully appreciated during each step of the modeling process (i.e., model selection, problem conceptualization, model application, and interpretation of results). C1 PACIFIC NW NATL LAB,RICHLAND,WA. ARGONNE NATL LAB,ARGONNE,IL 60439. TETRA TECH INC,LAFAYETTE,CA. RP Laniak, GF (reprint author), US EPA,OFF RES & DEV,ECOSYST RES DIV,960 COLL STN RD,ATHENS,GA 30605, USA. NR 8 TC 26 Z9 26 U1 2 U2 4 PU PLENUM PUBL CORP PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 SN 0272-4332 J9 RISK ANAL JI Risk Anal. PD APR PY 1997 VL 17 IS 2 BP 203 EP 214 DI 10.1111/j.1539-6924.1997.tb00859.x PG 12 WC Public, Environmental & Occupational Health; Mathematics, Interdisciplinary Applications; Social Sciences, Mathematical Methods SC Public, Environmental & Occupational Health; Mathematics; Mathematical Methods In Social Sciences GA XF221 UT WOS:A1997XF22100009 PM 9202489 ER PT J AU Hofer, E Hora, SC Iman, RL Peschke, J AF Hofer, E Hora, SC Iman, RL Peschke, J TI On the solution approach for Bayesian modeling of initiating event frequencies and failure rates SO RISK ANALYSIS LA English DT Article DE superpopulation; common incidence rate; failure rate; Bayesian modeling; uniform convergence AB Then is a need for plant-specific distributions of incidence and failure rates rather than distributions from pooled data which are based on the ''common incidence rate'' assumption. The so-called superpopulation model satisfies this need through a practically appealing approach that accounts for the variability over the population of plants. Unfortunately, the chosen order in which the integrals with respect to the individual plant rates lambda(i) (i = 0, 1..., m) and the parameters alpha,beta of the Gamma-population distribution are solved seems to drive the solution close to the common incidence rate distribution. It is shown that the solution obtained from interchanging the order and solving the integrals with respect to the individual plant rates by Monte Carlo simulation very quickly provides the plant specific distribution. This differing solution behaviour may be due to the lack of uniform convergence over (alpha,beta, lambda(i) (i = 1,..., m))-space. Examples illustrate the difference that may be observed. C1 UNIV HAWAII,HILO,HI 96720. SANDIA NATL LABS,ALBUQUERQUE,NM 87185. RP Hofer, E (reprint author), GESELL ANLAGEN & REAKTORSICHERHEIT,D-85748 GARCHING,GERMANY. NR 4 TC 16 Z9 16 U1 0 U2 0 PU PLENUM PUBL CORP PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 SN 0272-4332 J9 RISK ANAL JI Risk Anal. PD APR PY 1997 VL 17 IS 2 BP 249 EP 252 DI 10.1111/j.1539-6924.1997.tb00863.x PG 4 WC Public, Environmental & Occupational Health; Mathematics, Interdisciplinary Applications; Social Sciences, Mathematical Methods SC Public, Environmental & Occupational Health; Mathematics; Mathematical Methods In Social Sciences GA XF221 UT WOS:A1997XF22100013 ER PT J AU Fourney, WL Dick, RD Fordyce, DF Weaver, TA AF Fourney, WL Dick, RD Fordyce, DF Weaver, TA TI Effects of open gaps on particle velocity measurements SO ROCK MECHANICS AND ROCK ENGINEERING LA English DT Article AB Joints and bedding planes are present in nearly all geologic media. These discontinuities vary in the extent to which they are open and the material with which they are filled. The presence of such discontinuities affect the ground motions that result from the detonation of an explosive source. The effects of these discontinuities are especially important if it is desired to predict the size of the explosive source from measurements of ground motion - such as particle velocity or stress. In this paper we present results from a series of model tests conducted to investigate the effect of open gaps on the particle velocity that can be transmitted across them. Electromagnetic velocity gages were used to record particle velocities at several locations on either side of an open gap of known width. The study was restricted to the transmission of particle velocities normal to the gap and to the case where the gap was located in a region for which the stress was high but not greatly above the elastic limit of the material. The experimental results were compared qualitatively to results obtained from WONDY - a one dimensional Lagrangian finite difference code. Although the tests were conducted in laboratory models, the results can be scaled to compare to the full scale situation. C1 LOS ALAMOS NATL LAB,LOS ALAMOS,NM. RP Fourney, WL (reprint author), UNIV MARYLAND,DEPT AEROSP ENGN,COLLEGE PK,MD 20742, USA. NR 7 TC 13 Z9 16 U1 1 U2 2 PU SPRINGER-VERLAG WIEN PI VIENNA PA SACHSENPLATZ 4-6, PO BOX 89, A-1201 VIENNA, AUSTRIA SN 0723-2632 J9 ROCK MECH ROCK ENG JI Rock Mech. Rock Eng. PD APR-JUN PY 1997 VL 30 IS 2 BP 95 EP 111 DI 10.1007/BF01020127 PG 17 WC Engineering, Geological; Geosciences, Multidisciplinary SC Engineering; Geology GA WY407 UT WOS:A1997WY40700002 ER PT J AU Sun, WG Pitzer, RM McCurdy, CW AF Sun, WG Pitzer, RM McCurdy, CW TI A two-configuration study on the photodetachment cross-section for the 3 sigma(u) channel of F-2(-) SO SCIENCE IN CHINA SERIES A-MATHEMATICS PHYSICS ASTRONOMY LA English DT Article DE resonance; cross-section; photodetachment; configuration interaction AB An unusual resonance feature of the photodetachment cross-section for the 3 sigma(u) channel of F-2(-) observed in the early static-exchange study is confirmed by using correlated target (F-2) wavefunctions determined by configuration interaction (CI). The magnitude of the cross-sections is lowered from that in earlier calculation by the potential of the correlated target. C1 OHIO STATE UNIV,DEPT CHEM,COLUMBUS,OH 43210. LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550. RP Sun, WG (reprint author), SICHUAN UNION UNIV,DEPT APPL CHEM,CHENGDU 610065,PEOPLES R CHINA. NR 7 TC 1 Z9 1 U1 0 U2 0 PU SCIENCE CHINA PRESS PI BEIJING PA 16 DONGHUANGCHENGGEN NORTH ST, BEIJING 100717, PEOPLES R CHINA SN 1006-9283 J9 SCI CHINA SER A JI Sci. China Ser. A-Math. Phys. Astron. PD APR PY 1997 VL 40 IS 4 BP 432 EP 435 DI 10.1007/BF02911445 PG 4 WC Mathematics, Applied; Mathematics SC Mathematics GA WQ087 UT WOS:A1997WQ08700013 ER PT J AU Chlopecka, A AF Chlopecka, A TI Assessment of form of Cd, Zn and Pb in contaminated calcareous and gleyed soils in Southwest Poland (vol 188, pg 253, 1996) SO SCIENCE OF THE TOTAL ENVIRONMENT LA English DT Correction, Addition RP Chlopecka, A (reprint author), UNIV GEORGIA,SAVANNAH RIVER ECOL LAB,BIOGEOCHEM ECOL DIV,DRAWER E,AIKEN,SC 29802, USA. NR 1 TC 0 Z9 0 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0048-9697 J9 SCI TOTAL ENVIRON JI Sci. Total Environ. PD APR 1 PY 1997 VL 196 IS 3 BP 263 EP 263 PG 1 WC Environmental Sciences SC Environmental Sciences & Ecology GA WU608 UT WOS:A1997WU60800008 ER PT J AU Yu, KM Wang, L Walukiewicz, W AF Yu, KM Wang, L Walukiewicz, W TI The effects of synchrotron x-rays on the local structure and the recrystallization of ion damaged Si SO SEMICONDUCTOR SCIENCE AND TECHNOLOGY LA English DT Article ID SEMICONDUCTORS AB We have studied the effects of intense x-ray irradiation on the structure of crystalline Si amorphized by energetic ions and the subsequent solid phase epitaxial regrowth of the amorphous layers. We found that in the amorphized Si layers, although the ion dose is well above the amorphization threshold (as measured by Rutherford backscattering), small crystallites are still present. The absorption of x-rays by the Si atoms provides enough energy to disperse the small crystallites in the amorphous Si, reducing the number of interfacial defects as well as locally rearranging the atoms to form a homogeneously amorphous layer with close to four-fold coordinated environment. This rearrangement in local structure of the alpha-Si results in a nearly defect-free crystal after solid phase epitaxy. RP Yu, KM (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,CTR ADV MAT,DIV MAT SCI,BERKELEY,CA 94720, USA. RI Yu, Kin Man/J-1399-2012 OI Yu, Kin Man/0000-0003-1350-9642 NR 10 TC 5 Z9 5 U1 0 U2 0 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL, ENGLAND BS1 6BE SN 0268-1242 J9 SEMICOND SCI TECH JI Semicond. Sci. Technol. PD APR PY 1997 VL 12 IS 4 BP 460 EP 463 DI 10.1088/0268-1242/12/4/021 PG 4 WC Engineering, Electrical & Electronic; Materials Science, Multidisciplinary; Physics, Condensed Matter SC Engineering; Materials Science; Physics GA WV279 UT WOS:A1997WV27900020 ER PT J AU Kuruc, A AF Kuruc, A TI Efficient estimation of linear functionals in emission tomography SO SIAM JOURNAL ON APPLIED MATHEMATICS LA English DT Article DE nonparametric estimation; inverse problems; ill-posed problems ID COMPUTED-TOMOGRAPHY; INVERSE AB In emission tomography, the spatial distribution of a radioactive tracer is estimated from a finite sample of externally detected photons. We present an algorithm-independent theory of statistical accuracy attainable in emission tomography that makes minimal assumptions about the underlying image. Let f denote the tracer density as a function of position (i.e., f is the image being estimated). We consider the problem of estimating the linear functional Phi(f) = integral phi(x)f(x) dx, where phi is a smooth function, from n independent observations identically distributed according to the Radon transform of f. Assuming only that f is bounded above and below away from 0, we construct statistically efficient estimators for Phi(f). By definition, the variance of the efficient estimator is a best-possible lower bound (depending on phi and f) on the variance of unbiased estimators of Phi(f). Our results show that, in general, the efficient estimator will have a smaller variance than the standard estimator based on the filtered-backprojection reconstruction algorithm. The improvement in performance is obtained by exploiting the range properties of the Radon transform. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,BERKELEY,CA 94720. NR 27 TC 1 Z9 1 U1 0 U2 1 PU SIAM PUBLICATIONS PI PHILADELPHIA PA 3600 UNIV CITY SCIENCE CENTER, PHILADELPHIA, PA 19104-2688 SN 0036-1399 J9 SIAM J APPL MATH JI SIAM J. Appl. Math. PD APR PY 1997 VL 57 IS 2 BP 426 EP 452 DI 10.1137/S0036139995283201 PG 27 WC Mathematics, Applied SC Mathematics GA WR388 UT WOS:A1997WR38800007 ER PT J AU Lyness, JN Sloan, IH AF Lyness, JN Sloan, IH TI Cubature rules of prescribed merit SO SIAM JOURNAL ON NUMERICAL ANALYSIS LA English DT Article DE cubature; merit; multidimensional quadrature ID INTEGRATION AB We introduce a criterion for the evaluation of multidimensional quadrature, or cubature, rules for the hypercube: this is the merit of a rule which is closely related to its trigonometric degree and which reduces to the Zaremba figure of merit in the case of a lattice rule. We derive a family of rules Q(k)(s) having dimension s and merit 2(k). These rules seem to be competitive with lattice rules with respect to the merit that can be achieved with a given number of abscissas. C1 UNIV NEW S WALES,SCH MATH,SYDNEY,NSW 2033,AUSTRALIA. RP Lyness, JN (reprint author), ARGONNE NATL LAB,DIV MATH & COMP SCI,9700 S CASS AVE,ARGONNE,IL 60439, USA. RI Sloan, Ian/F-9958-2011 OI Sloan, Ian/0000-0003-3769-0538 NR 8 TC 4 Z9 4 U1 0 U2 0 PU SIAM PUBLICATIONS PI PHILADELPHIA PA 3600 UNIV CITY SCIENCE CENTER, PHILADELPHIA, PA 19104-2688 SN 0036-1429 J9 SIAM J NUMER ANAL JI SIAM J. Numer. Anal. PD APR PY 1997 VL 34 IS 2 BP 586 EP 602 DI 10.1137/S0036142994267485 PG 17 WC Mathematics, Applied SC Mathematics GA WT652 UT WOS:A1997WT65200010 ER PT J AU Feffer, PT Lin, RP SlassiSennou, S McBride, S Primbsch, JH Zimmer, G Pelling, RM Pehl, R Madden, N Malone, D Cork, C Luke, P Vedrenne, G Cotin, F AF Feffer, PT Lin, RP SlassiSennou, S McBride, S Primbsch, JH Zimmer, G Pelling, RM Pehl, R Madden, N Malone, D Cork, C Luke, P Vedrenne, G Cotin, F TI Solar energetic ion and electron limits from HIREGS observations SO SOLAR PHYSICS LA English DT Article ID GAMMA-RAY LINE; FLARE NEUTRON; PARTICLES; CORONA; DISTRIBUTIONS; ABUNDANCES; EMISSION; SPECTRA; BURSTS AB The HIgh-REsolution Gamma-ray and hard X-ray Spectrometer (HIREGS) consists of an actively shielded array of twelve liquid-nitrogen-cooled germanium detectors designed to provide unprecedented spectral resolution and narrow-line sensitivity for solar gamma-ray line observations. Two long-duration, circumpolar balloon flights of HIREGS in Antarctica (10-24 January, 1992 and 31 December, 1992- 10 January, 1993) provided 90.9 and 20.4 hours of solar observations, respectively. During the observations, eleven soft X-ray bursts at C levels and above (largest M1.7) occurred, and three small solar hard X-ray bursts were detected by the Compton Gamma-Ray Observatory. HIREGS detected a significant increase above 30 keV in one. No solar gamma-ray line emission was detected. Limits on the 2.223-MeV line and the hard X-ray emission are used to estimate the relative contribution of protons and electrons to the energy in flares, and to coronal heating. For the 2.223-MeV line, the upper limit fluence is less than or similar to 0.8 ph cm(-2) in the flares, and the upper limit flux is 1.8 x 10(-4) ph s(-1) cm(-2) in the absence of Bares. These limits imply that less than or similar to 6 x 10(30) (2 sigma) protons above 30 MeV were accelerated in the hares, assuming standard photospheric abundances and a thick target model. The total energy contained in the accelerated protons >30 MeV is less than or similar to 4 x 10(26) ergs, but this limit can be more than 10(30) ergs if the spectrum extends down to similar to 1 MeV. The upper limit on the total energy in accelerated electrons during the observed flares can also exceed 10(30) ergs if the spectrum goes down to similar to 7 keV. Quiet-Sun observations indicate that less than or similar to 10(26) erg s(-1) are deposited by energetic protons > 1 MeV, well below the 10(27) - 10(28) erg s(-1) required for coronal heating, while <3 x 10(27) erg s(-1) are deposited by energetic electrons, which does not exclude the possibility of coronal heating by quiet-time accelerated electrons. The quiet-Sun observations also suggest that if protons stored in the corona are to supply the energy for flares, as suggested by Elliot (1964), the proton spectrum must extend down to at least similar to 2 MeV. However, collisional losses at typical coronal-loop densities prevent those low-energy protons from being stored for greater than or similar to 10(4) s. It therefore seems unlikely that the energy for flares could come from energetic protons stored over long periods. C1 UNIV CALIF SAN DIEGO, CTR ASTROPHYS & SPACE SCI, LA JOLLA, CA 92093 USA. UNIV CALIF BERKELEY, LAWRENCE BERKELEY NATL LAB, BERKELEY, CA 94720 USA. CTR ETUD SPATIALE RAYONNEMENTS, TOULOUSE, FRANCE. RP Feffer, PT (reprint author), UNIV CALIF BERKELEY, SPACE SCI LAB, BERKELEY, CA 94720 USA. NR 55 TC 5 Z9 5 U1 0 U2 0 PU SPRINGER PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0038-0938 J9 SOL PHYS JI Sol. Phys. PD APR PY 1997 VL 171 IS 2 BP 419 EP 445 DI 10.1023/A:1004911511905 PG 27 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA WT121 UT WOS:A1997WT12100012 ER PT J AU Shen, YR AF Shen, YR TI Wave mixing spectroscopy for surface studies SO SOLID STATE COMMUNICATIONS LA English DT Review ID SUM-FREQUENCY-GENERATION; VIBRATIONAL-ENERGY TRANSFER; LIQUID NORMAL-ALKANES; OPTICAL 2ND-HARMONIC GENERATION; ADSORBATE-SUBSTRATE VIBRATION; ELECTRONIC-TRANSITIONS; INFRARED-SPECTROSCOPY; METAL-SURFACES; SEMICONDUCTOR SURFACES; HYDROPHOBIC SURFACE AB Optical second-harmonic generation and sum-frequency generation are intrinsically surface-specific. They can therefore be used as effective surface probes. We briefly review the wide range of applications found for these probes in recent years. Many of them have opened the door for exciting new research opportunities. Published by Elsevier Science Ltd. C1 UNIV CALIF BERKELEY, LAWRENCE BERKELEY LAB, DIV MAT SCI, BERKELEY, CA 94720 USA. RP Shen, YR (reprint author), UNIV CALIF BERKELEY, DEPT PHYS, BERKELEY, CA 94720 USA. NR 100 TC 58 Z9 58 U1 1 U2 10 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0038-1098 J9 SOLID STATE COMMUN JI Solid State Commun. PD APR PY 1997 VL 102 IS 2-3 BP 221 EP 229 DI 10.1016/S0038-1098(96)00726-0 PG 9 WC Physics, Condensed Matter SC Physics GA WQ084 UT WOS:A1997WQ08400016 ER PT J AU Vartuli, CB Pearton, SJ Abernathy, CR MacKenzie, JD Lovejoy, ML Shul, RJ Zolper, JC Baca, AG HagerottCrawford, M Jones, A Ren, F AF Vartuli, CB Pearton, SJ Abernathy, CR MacKenzie, JD Lovejoy, ML Shul, RJ Zolper, JC Baca, AG HagerottCrawford, M Jones, A Ren, F TI Conduction mechanisms in W and WSix ohmic contacts to InGaN and InN SO SOLID-STATE ELECTRONICS LA English DT Article ID MOLECULAR-BEAM EPITAXY; LIGHT-EMITTING-DIODES; GAN; RESISTANCE; GROWTH AB The temperature dependence of the specific contact resistance of Wand WSi0.44 contacts On n(+) In0.65Ga0.35N and InN was measured in the range -50-125 degrees C. The results were compared to theoretical values for different conduction mechanisms, to further elucidate the conduction mechanism in these contact structures. The data indicates the conduction mechanism is field emission for these contact schemes for all but as-deposited metal to InN where thermionic emission appears to be the dominant mechanism. The contacts were found to produce low specific resistance ohmic contacts to InGaN at room temperature, rho(c) similar to 10(-7) Omega . cm(2) for W and rho(c) of 4 x 10(-7) Omega . cm(2) for WSix. InN metallized with W produced ohmic contacts with rho(c) similar to 10(-7) Omega . cm(2) and rho(c) similar to 10(-6) Omega . cm(2) for WSix at room temperature. (C) 1997 Elsevier Science Ltd. C1 SANDIA NATL LABS,ALBUQUERQUE,NM 87185. USA,RES LAB,FT MONMOUTH,NJ 07703. AT&T BELL LABS,LUCENT TECHNOL,MURRAY HILL,NJ 07974. RP Vartuli, CB (reprint author), UNIV FLORIDA,DEPT MAT SCI & ENGN,GAINESVILLE,FL 32611, USA. NR 18 TC 5 Z9 6 U1 0 U2 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0038-1101 J9 SOLID STATE ELECTRON JI Solid-State Electron. PD APR PY 1997 VL 41 IS 4 BP 531 EP 534 DI 10.1016/S0038-1101(96)00188-8 PG 4 WC Engineering, Electrical & Electronic; Physics, Applied; Physics, Condensed Matter SC Engineering; Physics GA WT062 UT WOS:A1997WT06200004 ER PT J AU Hsieh, G Mason, TO Garboczi, EJ Pederson, LR AF Hsieh, G Mason, TO Garboczi, EJ Pederson, LR TI Experimental limitations in impedance spectroscopy .3. Effect of reference electrode geometry/position SO SOLID STATE IONICS LA English DT Article DE impedance spectroscopy; YSZ; Pt electrode; Ag electrode; reference electrode ID STABILIZED ZIRCONIA INTERFACE; OXIDE FUEL-CELLS; CEMENT PASTE; OXYGEN REDUCTION; DISK ELECTRODE; RESISTANCE; LOCATION; MODEL AB Experiments and computer simulations on Pt/YSZ specimens in various electrode configurations were performed to investigate the effect of reference electrode geometry/position on the accuracy of impedance measurements. The internal, Luggin probe-type, geometry is the preferred reference electrode configuration as it accurately measures both electrolyte and electrode impedances. External, 'pseudoreference', electrodes sample an averaged effective potential and can register inaccurate electrolyte resistances, sometimes with distorted electrode arcs. A symmetric configuration can accurately measure the impedance of an electrode; however, the electrolyte resistance will not scale linearly according to sample dimensions, as one might expect, An asymmetric configuration exhibits both non-linear partitioning of electrolyte resistance and distortions in the electrode impedance are under certain circumstances. The reliability of three-electrode measurements is very sensitive to aspect ratio and electrode configuration. C1 NORTHWESTERN UNIV, DEPT MAT SCI & ENGN, EVANSTON, IL 60208 USA. NIST, BLDG MAT DIV, GAITHERSBURG, MD 20899 USA. PACIFIC NW LAB, DEPT CHEM & MAT SCI, RICHLAND, WA 99352 USA. RI Mason, Thomas/B-7528-2009 NR 29 TC 56 Z9 56 U1 4 U2 26 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0167-2738 J9 SOLID STATE IONICS JI Solid State Ion. PD APR PY 1997 VL 96 IS 3-4 BP 153 EP 172 DI 10.1016/S0167-2738(97)00073-8 PG 20 WC Chemistry, Physical; Physics, Condensed Matter SC Chemistry; Physics GA WY909 UT WOS:A1997WY90900004 ER PT J AU Hwang, SJ Fernandez, C Amoureux, JP Cho, J Martin, SW Pruski, M AF Hwang, SJ Fernandez, C Amoureux, JP Cho, J Martin, SW Pruski, M TI Quantitative study of the short range order in B2O3 and B2S3 by MAS and two-dimensional triple-quantum MAS B-11 NMR SO SOLID STATE NUCLEAR MAGNETIC RESONANCE LA English DT Article DE multiple-quantum NMR of quadrupolar nuclei; boron trioxide; boron trisulfide ID SOLID-STATE NMR; NUCLEAR-QUADRUPOLE RESONANCE; BORATE GLASSES; BORON; SPECTROSCOPY; ANGLE; SPECTRA; SYSTEM; OXIDE AB Two-dimensional multiple-quantum magic angle spinning (MQMAS) NMR and MAS NMR of B-11 at various magnetic fields, were applied to elucidate the structure of vitreous (glassy) boron trioxide (v-B2O3), vitreous boron trisulfide (v-B2S3) and crystalline boron trisulfide (c-B2S3). These techniques, when combined with computer simulations of the resulting spectra, provide the isotropic chemical shifts and the quadrupole parameters, as well as a quantitative measure of the intensities of various boron resonances. The MAS NMR of v-B2O3 produced overlapping anisotropic lineshapes corresponding to the -1/2 <-> 1/2 transition in two distinct types of BO3 units with 3(+/-0.08):1 intensity ratio. A combination of MAS and the multiple-quantum method resulted in a better resolved, isotropic B-11 spectrum of v-B2O3. A remarkable enhancement of resolution of the MQMAS NMR proved instrumental in finding and identifying various impurities present in V-B2S3 and c-B2S3. In addition to the resonances from boron in two types of BS, groups, four other structural units, BOS,, BO2S, BO3 and BS4, were elucidated from the spectra of vitreous and crystalline samples. The effects of various experimental parameters, such as the magnitude of the B-0 and B-1 fields, on the resolution of the MAS and MQMAS techniques are also shown. (C) 1997 Elsevier Science B.V. C1 IOWA STATE UNIV SCI & TECHNOL,AMES LAB,AMES,IA 50011. UNIV SCI & TECH LILLE FLANDRES ARTOIS,CNRS URA 801,LAB DYNAM & STRUCT MAT MOL,F-59655 VILLENEUVE DASCQ,FRANCE. IOWA STATE UNIV,DEPT MAT SCI & ENGN,AMES,IA 50011. RI Cho, Jaephil/E-4265-2010; fernandez, christian/C-3158-2008 OI fernandez, christian/0000-0002-5476-3148 NR 37 TC 61 Z9 62 U1 7 U2 23 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0926-2040 J9 SOLID STATE NUCL MAG JI Solid State Nucl. Magn. Reson. PD APR PY 1997 VL 8 IS 2 BP 109 EP 121 DI 10.1016/S0926-2040(96)01280-5 PG 13 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical; Physics, Condensed Matter; Spectroscopy SC Chemistry; Physics; Spectroscopy GA XF178 UT WOS:A1997XF17800004 PM 9203284 ER PT J AU Hu, JZ Zhou, JW Yang, BL Li, LY Qiu, JQ Ye, CH Solum, MS Wind, RA Pugmire, RJ Grant, DM AF Hu, JZ Zhou, JW Yang, BL Li, LY Qiu, JQ Ye, CH Solum, MS Wind, RA Pugmire, RJ Grant, DM TI Dynamic nuclear polarization of nitrogen-15 in benzamide SO SOLID STATE NUCLEAR MAGNETIC RESONANCE LA English DT Article DE dynamic Nuclear Polarization; solid state N-15 NMR; benzamide; free radicals; relaxation time ID C-13 NMR-SPECTROSCOPY; SOLIDS; INTERFACE; BLENDS; DNP AB A N-15 dynamic nuclear polarization (DNP) experiment is reported in which a N-15 DNP enhancement factor of approximately 2.6 x 10(2) is obtained on free radical doped samples of 99% N-15 labeled benzamide. The free radicals BDPA (1:1 complex of alpha,gamma-bisdiphenylene-beta-phenylallyl with benzene) and DPPH (2,2-Di(4-tert-octylphenyl)-1-picrylhydrazyl) are used as dopants and the spin relaxation effects of adding these dopants are studied by means of changes in proton and nitrogen T-1 values of the samples. The combination in solids of a very low natural abundance, 0.37%, a small gyromagnetic ratio, and a long spin-lattice relaxation time for N-15 nuclei create severe sensitivity problems that, in large part, are ameliorated by the signal enhancement observed in the N-15 DNP experiment on samples containing free electrons. (C) 1997 Elsevier Science B.V. C1 UNIV UTAH, DEPT CHEM & FUELS ENGN, SALT LAKE CITY, UT 84112 USA. ACAD SINICA, WUHAN INST PHYS, LAB MAGNET RESONANCE & ATOM & MOL PHYS, WUHAN 430071, PEOPLES R CHINA. UNIV UTAH, DEPT CHEM, SALT LAKE CITY, UT 84112 USA. PACIFIC NW LAB, RICHLAND, WA 99352 USA. RI Hu, Jian Zhi/F-7126-2012 NR 24 TC 15 Z9 16 U1 2 U2 19 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0926-2040 J9 SOLID STATE NUCL MAG JI Solid State Nucl. Magn. Reson. PD APR PY 1997 VL 8 IS 2 BP 129 EP 137 DI 10.1016/S0926-2040(96)01263-5 PG 9 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical; Physics, Condensed Matter; Spectroscopy SC Chemistry; Physics; Spectroscopy GA XF178 UT WOS:A1997XF17800006 PM 9203286 ER PT J AU Alam, TM AF Alam, TM TI DEFT polarization transfer in Si-29-NMR investigations of organically modified alkoxysilanes SO SPECTROCHIMICA ACTA PART A-MOLECULAR AND BIOMOLECULAR SPECTROSCOPY LA English DT Article DE nuclear magnetic resonance; organically modified alkoxysilanes; sol-gel materials ID SOL-GEL POLYMERIZATION; DQF COSY NMR; SPIN SYSTEMS; INEPT; ENHANCEMENT; HYDROLYSIS; HETERONUCLEAR; POLYMERS; KINETICS; SIGNALS AB The DEFT heteronuclear polarization transfer pulse sequence was used to unambiguously assign the high-resolution Si-29-NMR (nuclear magnetic resonance) for the hydrolyzed monomer species in trimethylmethoxysilane, dimethyldimethoxysilane and methyltrimethoxysilane. The response of the DEFT sequence as a function of the interpulse delay time tau and the variable pulse angle theta were analyzed for spin systems with multiple heteronuclear J-couplings. These results allow the DEFT sequence to be optimized for sensitivity enhancement in addition to providing an editing method for Si-29-NMR of organically modified alkoxysilanes. (C) 1997 Elsevier Science B.V. RP Alam, TM (reprint author), SANDIA NATL LABS,POB 5800,ALBUQUERQUE,NM 87185, USA. NR 28 TC 7 Z9 7 U1 0 U2 2 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 1386-1425 J9 SPECTROCHIM ACTA A JI Spectroc. Acta Pt. A-Molec. Biomolec. Spectr. PD APR PY 1997 VL 53 IS 4 BP 545 EP 552 DI 10.1016/S1386-1425(96)01806-9 PG 8 WC Spectroscopy SC Spectroscopy GA WY636 UT WOS:A1997WY63600010 ER PT J AU Eldridge, JE Xie, Y Lin, Y Homes, CC Wang, HH Williams, JM Kini, AM Schlueter, JA AF Eldridge, JE Xie, Y Lin, Y Homes, CC Wang, HH Williams, JM Kini, AM Schlueter, JA TI Infrared and Raman studies of the organic superconductor kappa-(BEDT-TTF)(2)[Cu(NCS)(2)] and its C-13(4) isotopic analog SO SPECTROCHIMICA ACTA PART A-MOLECULAR AND BIOMOLECULAR SPECTROSCOPY LA English DT Article DE BEDT-TTF; ET; kappa-(ET)(2)[Cu(NCS)(2)]; Raman; infrared; electron-phonon ID BIS(ETHYLENEDITHIO)TETRATHIAFULVALENE BEDT-TTF; OPTICAL-PROPERTIES; LOW-TEMPERATURE; AB-INITIO; (BEDT-TTF)2; SPECTRA AB We report on low-temperature infrared reflectivity measurements as well as room-temperature Raman measurements of kappa-(ET)(2)[Cu(NCS)(2)] and its C-13(4) isotopic analog, in which the four carbon atoms in the terminal ethylene groups have been substituted. The measured isotopic frequency shifts are used to support previous assignments of the infrared features to A(g) and B-3g modes. Two Raman spectrometers were used, one using a visible laser and the other an infrared laser. The spectra are very dissimilar, due to the resonant nature of the scattering. The electronic resonance responsible for the infrared-laser Raman scattering appears to be the same as that occurring in the infrared spectrum. We have reassigned nu(9)(A(g)) in the infrared spectrum and successfully compare our frequency shifts due to electron-phonon coupling with those recently calculated. (C) 1997 Elsevier Science B.V. C1 SIMON FRASER UNIV,DEPT PHYS,BURNABY,BC V5A 1S6,CANADA. ARGONNE NATL LAB,DIV CHEM & MAT SCI,ARGONNE,IL 60439. RP Eldridge, JE (reprint author), UNIV BRITISH COLUMBIA,DEPT PHYS,6224 AGR RD,VANCOUVER,BC V6T 1Z1,CANADA. RI Kini, Aravinda/F-4467-2012 NR 14 TC 37 Z9 37 U1 1 U2 3 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 1386-1425 J9 SPECTROCHIM ACTA A JI Spectroc. Acta Pt. A-Molec. Biomolec. Spectr. PD APR PY 1997 VL 53 IS 4 BP 565 EP 573 DI 10.1016/S1386-1425(96)01803-3 PG 9 WC Spectroscopy SC Spectroscopy GA WY636 UT WOS:A1997WY63600012 ER PT J AU McCoy, JM Maksym, PA AF McCoy, JM Maksym, PA TI Dynamical calculation of high-resolution reflection electron microscopy lattice fringes from the Si(111) 7x7 surface SO SURFACE SCIENCE LA English DT Article DE computer simulations; electron-solid interactions, scattering and diffraction; low index single crystal surfaces; reflection electron microscopy (REM); reflection high-energy electron diffraction (RHEED); silicon ID X 7 SURFACE; SI(001) SURFACE; REM IMAGES; RHEED; DIFFRACTION; SIMULATION; SCATTERING AB High-resolution reflection electron microscopy (HR-REM) lattice fringes for the flat Si(111)7 x 7 surface are simulated using our earlier reported theory of REM image formation. This simulation procedure employs a 2D Bloch wave formulation of dynamical (multiple scattering) elastic reflection high-energy electron diffraction (RHEED) theory combined with conventional electron microscopy (Abbe) imaging theory. One of the purposes of this study is to provide the first critical comparison of HR-REM images simulated using this procedure with experimental images for the Si(111)7 x 7 surface. It is found that it is possible to reproduce in the simulations all of the fringe periodicities observed in real HR-REM images from this surface. The incorporation into the simulation procedure of the effects of primary electron beam divergence and chromatic aberration is described in detail. The primary beam divergence is essential to reproduce in simulated images the correct defocusing behaviour. When these details are incorporated, the simulation procedure gives good agreement with experiment. This work shows that quantitative HR-REM image simulation constitutes a valuable interpretative tool to be used in support of experimental HR-REM. C1 UNIV LEICESTER, DEPT PHYS & ASTRON, LEICESTER LE1 7RH, LEICS, ENGLAND. RP McCoy, JM (reprint author), PACIFIC NW LAB, ENVIRONM MOL SCI LAB, POB 999, RICHLAND, WA 99352 USA. NR 23 TC 2 Z9 2 U1 1 U2 2 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 1 PY 1997 VL 375 IS 2-3 BP 183 EP 194 DI 10.1016/S0039-6028(96)01284-8 PG 12 WC Chemistry, Physical; Physics, Condensed Matter SC Chemistry; Physics GA WU472 UT WOS:A1997WU47200009 ER PT J AU Tao, HS Diebold, U Shinn, ND Madey, TE AF Tao, HS Diebold, U Shinn, ND Madey, TE TI Decomposition of P(CH3)(3) on Ru(0001): Comparison with PH3 and PCl3 SO SURFACE SCIENCE LA English DT Article DE phosphorus compounds; ruthenium; soft x-ray photoelectron spectroscopy; surface chemical reaction; trimethyl phosphine ID TRANSITION-METAL SURFACES; MORSE-POTENTIAL APPROACH; PF3; DESORPTION; ADSORPTION; CHEMISTRY; PT(111); CO AB The decomposition of P(CH3)(3) adsorbed on Ru(0001) at 80 K is studied by soft X-ray photoelectron spectroscopy using synchrotron radiation. Using the chemical shifts in the P 2p core levels, we are able to identify various phosphorus-containing surface reaction products and follow their reactions on Ru(0001). It is found that P(CH3)(3) undergoes a step-wise demethylation on Ru(0001), P(CH3)(3) --> P(CH3)(2) --> P(CH3) --> P, which is complete around similar to 450 K. These results are compared with the decomposition of isostructural PH3 and PCl3 on Ru(0001). The decomposition of PH3 involves a stable intermediate, labeled as PHx, and follows a reaction of: PH3 --> PHx --> P, which is complete around similar to 190 K. The conversion of chemisorbed phosphorus to ruthenium phosphide is observed and is complete around similar to 700 K on Ru(0001). PCl3 also follows a step-wise decomposition reaction, PCl3 --> PCl2 --> PCl2 --> P, which is complete around similar to 300 K. The energetics of the adsorption and the step-wise decomposition reactions of PH3, PCl3 and P(CH3)(3) are estimated using the bond order conservation Morse potential (BOCMP) method. The energetics calculated using the BOCMP method agree qualitatively with the experimental data. (C) 1997 Elsevier Science B.V. C1 RUTGERS STATE UNIV,DEPT PHYS & ASTRON,PISCATAWAY,NJ 08855. RUTGERS STATE UNIV,SURFACE MODIFICAT LAB,PISCATAWAY,NJ 08855. TULANE UNIV,DEPT PHYS,NEW ORLEANS,LA 70118. SANDIA NATL LABS,ALBUQUERQUE,NM 87185. RI Diebold, Ulrike/A-3681-2010 OI Diebold, Ulrike/0000-0003-0319-5256 NR 25 TC 14 Z9 14 U1 1 U2 7 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0039-6028 J9 SURF SCI JI Surf. Sci. PD APR 1 PY 1997 VL 375 IS 2-3 BP 257 EP 267 DI 10.1016/S0039-6028(96)01280-0 PG 11 WC Chemistry, Physical; Physics, Condensed Matter SC Chemistry; Physics GA WU472 UT WOS:A1997WU47200017 ER PT J AU Kellerman, BK Chason, E Adams, DP Mayer, TM White, JM AF Kellerman, BK Chason, E Adams, DP Mayer, TM White, JM TI In-situ X-ray reflectivity investigation of growth and surface morphology evolution during Fe chemical vapor deposition on Si(001) SO SURFACE SCIENCE LA English DT Article DE chemical vapor deposition; iron; low index single crystal surfaces; metal-semiconductor interfaces; nucleation; silicon; surface roughening; surface structure, morphology, roughness, and topography; x-ray scattering, diffraction, and reflection ID EPITAXIAL-GROWTH; ELLIPSOMETRY; TEMPERATURE; NUCLEATION; ADSORPTION; SILICON; CO; DECOMPOSITION; FE(CO)5; SI(100) AB We used in situ X-ray reflectivity (XRR) to study the kinetics and structural evolution in the early stages of Fe deposition from the thermal decomposition of Fe(CO)(5) in the temperature range 90-220 degrees C. We simultaneously measured the polycrystalline Fe film thicknesss (extending up to 60 Angstrom thick films) as well as the Fe surface roughness and Fe/Si interface width as a function of exposure, From the thickness measurements, we were able to separate the nucleation and growth regimes and find direct evidence for an autocatalytic growth effect: an induction period indicative of the rate-limiting nucleation of Fe islands on the Si(001) substrate followed by a linear increase in growth representing Fe deposition on Fe. The incubation period decreased with increasing temperature. Using a modified version of classical nucleation theory to model the evolution of film thickness for the initial stages of film growth, we found a difference in the activation energies for the thermal decomposition of the Fe(CO)(5) precursor on Si(001) and Fe, 0.78+/-0.09 eV and 0.20+/-0.02 eV, respectively. The surface roughness decreased with increasing temperature due to enhanced nucleation at higher temperatures. The evolution of the roughness is in agreement with a simple model of nucleation and coalescence of three-dimensional islands. The large difference in activation energies for nucleation and growth is responsible for the behavior of both the time dependence of the deposition rate and morphology evolution. A relatively narrow Fe/Si interface width indicates that very little intermixing occurs in this temperature regime. (C) 1997 Elsevier Science B.V. C1 SANDIA NATL LABS,ALBUQUERQUE,NM 87185. UNIV TEXAS,CTR SCI & TECHNOL,AUSTIN,TX 78712. NR 26 TC 22 Z9 22 U1 0 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 APR 1 PY 1997 VL 375 IS 2-3 BP 331 EP 339 DI 10.1016/S0039-6028(96)01267-8 PG 9 WC Chemistry, Physical; Physics, Condensed Matter SC Chemistry; Physics GA WU472 UT WOS:A1997WU47200023 ER PT J AU Dewey, SL Chaurasia, CS Chen, CE Volkow, ND Clarkson, FA Porter, SP StraughterMoore, RM Alexoff, DL Tedeschi, D Russo, NB Fowler, JS Brodie, JD AF Dewey, SL Chaurasia, CS Chen, CE Volkow, ND Clarkson, FA Porter, SP StraughterMoore, RM Alexoff, DL Tedeschi, D Russo, NB Fowler, JS Brodie, JD TI GABAergic attenuation of cocaine-induced dopamine release and locomotor activity SO SYNAPSE LA English DT Article DE dopamine; ethanol; lorazepam; gamma-vinyl GABA; cocaine; microdialysis ID POSITRON EMISSION TOMOGRAPHY; GABA; PET AB GABA modulates dopamine concentrations in the nucleus accumbens and corpus striatum. Using in vivo microdialysis techniques we examined this modulatory role and the extent to which three different GABAergic drugs can attenuate cocaine's ability to increase extracellular dopamine concentrations and gross locomotor activity. Ethanol, lorazepam (Ativan), and gamma-vinyl GABA (GVG) significantly and dose-dependently attenuated cocaine-induced dopamine release in the corpus striatum of freely moving animals. Unlike ethanol or lorazepam, however, GVG is not a sedative hypnotic in the doses used, and hence the strategy of selectively increasing GABAergic activity by suicide inhibition of the catabolic enzyme, GABA-transaminase, offers the unique advantage of attenuating cocaine-induced dopamine release without the apparent side effects typically associated with sedative hypnotics. (C) 1997 Wiley-Liss, Inc. C1 BROOKHAVEN NATL LAB,DEPT MED,UPTON,NY 11973. ST JOHNS UNIV,COLL PHARM & ALLIED HLTH PROFESS,QUEENS,NY. NYU,SCH MED,DEPT PSYCHIAT,NEW YORK,NY 10016. RP Dewey, SL (reprint author), BROOKHAVEN NATL LAB,DEPT CHEM,UPTON,NY 11973, USA. FU NIMH NIH HHS [MH-49165] NR 22 TC 97 Z9 98 U1 0 U2 3 PU WILEY-LISS PI NEW YORK PA DIV JOHN WILEY & SONS INC, 605 THIRD AVE, NEW YORK, NY 10158-0012 SN 0887-4476 J9 SYNAPSE JI Synapse PD APR PY 1997 VL 25 IS 4 BP 393 EP 398 DI 10.1002/(SICI)1098-2396(199704)25:4<393::AID-SYN11>3.0.CO;2-W PG 6 WC Neurosciences SC Neurosciences & Neurology GA WQ983 UT WOS:A1997WQ98300011 PM 9097399 ER PT J AU Griffith, WL AF Griffith, WL TI Conference report - Paper industry research challenge: Chasing down the scientists SO TAPPI JOURNAL LA English DT Editorial Material RP Griffith, WL (reprint author), OAK RIDGE NATL LAB,BLDG 4500 S,MS 150,POB 2008,OAK RIDGE,TN 37831, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU TECH ASSN PULP PAPER IND INC PI NORCROSS PA 15 TECHNOLOGY PARK SOUTH, NORCROSS, GA 30092 SN 0734-1415 J9 TAPPI J JI TAPPI J. PD APR PY 1997 VL 80 IS 4 BP 261 EP 263 PG 3 WC Materials Science, Paper & Wood SC Materials Science GA WT486 UT WOS:A1997WT48600027 ER PT J AU Loreau, M DeAngelis, DL AF Loreau, M DeAngelis, DL TI Source-sink dynamics and the coexistence of species on a single resource SO THEORETICAL POPULATION BIOLOGY LA English DT Article ID PREDATOR-MEDIATED COEXISTENCE; METAPOPULATION DYNAMICS; REGIONAL COEXISTENCE; POPULATION-DYNAMICS; PATCHY ENVIRONMENT; 2 COMPETITORS; MODELS; EQUILIBRIUM; INTERFERENCE; DISPERSAL AB We investigate the potential for coexistence of species that compete for a shared resource when the resource occurs in both a source area acting as a refuge and a sink area where it is used by the competing species. Our model shows that the mixing rate between the source and sink resource populations has a dramatic influence on the outcome of competition. When there is a strict sink-source dependence, so that resource renewal in the sink is entirely dependent on the source, only exploitation competition decides which species can survive at a very small mixing rate. Increasing the flow rate basically amounts to increasing the role played by interference competition. If interspecific interference is very small, compared with intraspecific interference, increasing the mixing rate allows coexistence of many species, indeed, unlimited coexistence if the species' resource exploitation efficiencies are similar enough. If interspecific interference is significant and there is a trade-off between the exploitation and interference competitive abilities of two species, it is possible to have one species replacing the other along a gradient of increasing mixing rate, with either coexistence or alternative single-species equilibria at intermediate values of the mixing rate. It is also possible to have one species always outcompeting the other, or alternative single-species stable equilibria at large mixing rates. When the strict sink-source dependence is relaxed by allowing the resource to have a partly independent renewal-loss dynamics in the sink area, the variety of possible outcomes along a gradient of mixing rate is further increased. These outcomes are often strongly sensitive to the parameters of resource dynamics and interspecific interference competition. The implications of these results for biological conservation can be profound; detailed knowledge of interspecific interactions appears to be necessary to determine the effect of any land management that alters dispersal opportunities. (C) 1997 Academic Press. C1 UNIV PARIS 06,F-75230 PARIS 05,FRANCE. OAK RIDGE NATL LAB,DIV ENVIRONM SCI,OAK RIDGE,TN 37831. RP Loreau, M (reprint author), ECOLE NORMALE SUPER,INST ECOL,46 RUE ULM,F-75230 PARIS 05,FRANCE. NR 44 TC 15 Z9 15 U1 1 U2 6 PU ACADEMIC PRESS INC JNL-COMP SUBSCRIPTIONS PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 SN 0040-5809 J9 THEOR POPUL BIOL JI Theor. Popul. Biol. PD APR PY 1997 VL 51 IS 2 BP 79 EP 93 DI 10.1006/tpbi.1997.1298 PG 15 WC Ecology; Evolutionary Biology; Genetics & Heredity SC Environmental Sciences & Ecology; Evolutionary Biology; Genetics & Heredity GA WW853 UT WOS:A1997WW85300001 ER PT J AU Thomas, LC Boller, A Okazaki, I Wunderlich, B AF Thomas, LC Boller, A Okazaki, I Wunderlich, B TI Modulated differential scanning calorimetry in the glass transition region .4. Pseudo-isothermal analysis of the polystyrene glass transition SO THERMOCHIMICA ACTA LA English DT Article DE temperature modulated calorimetry; heat capacity; glass transition; irreversible thermodynamics; polystyrene ID HEAT-CAPACITY; TEMPERATURE AB The kinetics of the glass transition of Polystyrene is measured by quasi-isothermal, temperature-modulated differential scanning calorimetry (TMDSC) and compared to pseudo-isothermal analyses of standard TMDSC traces. Quasi-isothermal TMDSC is carried out at a series of fixed average temperatures, modulated sinusoidally with an amplitude of +/-1.0 K and a period of 100 s. These measurements use, thus only a single time scale defined by the modulation frequency. The standard use of TMDSC adds a second time scale to the experiment, the underlying heating and cooling rates [q] at 1 K min(-1). In the pseudo-isothermal analysis of standard MDSC, the effects of the underlying heating and cooling rates are separated by subtraction of averages over full modulation periods from the modulated temperature and heat flow. The small differences in the reversing, apparent heat capacity between MDSC heating and cooling traces are measured and linked to the kinetic expressions of irreversible thermodynamics and interpreted using the hole theory. As the sample moves away from the equilibrium of the liquid state, the kinetics depends increasingly on the thermal history, and the expected deviations from a first-order kinetic expression are observed. (C) 1997 Elsevier Science B.V. C1 UNIV TENNESSEE,DEPT CHEM,KNOXVILLE,TN 37996. TA INSTRUMENTS INC,NEW CASTLE,DE 19720. OAK RIDGE NATL LAB,DIV CHEM & ANALYT SCI,OAK RIDGE,TN 37831. NR 24 TC 24 Z9 25 U1 2 U2 11 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0040-6031 J9 THERMOCHIM ACTA JI Thermochim. Acta PD APR 1 PY 1997 VL 291 IS 1-2 BP 85 EP 94 DI 10.1016/S0040-6031(96)03071-7 PG 10 WC Thermodynamics; Chemistry, Analytical; Chemistry, Physical SC Thermodynamics; Chemistry GA XD261 UT WOS:A1997XD26100012 ER PT J AU Cooper, CA Glass, RJ Tyler, SW AF Cooper, CA Glass, RJ Tyler, SW TI Experimental investigation of the stability boundary for double-diffusive finger convection in a Hele-Shaw cell SO WATER RESOURCES RESEARCH LA English DT Article ID POROUS-MEDIUM; SALT FINGERS AB Double-diffusive convection may be an important transport phenomenon in subsurface porous media and fractures. The classic linear stability analysis derived for a porous medium with two components stratified such that each affects the vertical density gradient in an opposing manner predicts double-diffusive finger instability to occur when Rs(1) + Rs(2) greater than or equal to Rs(c), where Rs(1) and Rs(2) are the Rayleigh numbers of the faster and slower diffusing components, respectively, and Rs, is a critical value dependent upon the boundary conditions (0 less than or equal to Rs(c) less than or equal to 4 pi(2)). For cases where Rs(c)/\Rs(1)\ much less than 1, the above result can be simplified to -R(rho) < 1/tau, where R(rho) is the buoyancy ratio of the fluid and tau is the ratio of diffusivities (0 < tau < 1). We experimentally tested the applicability of both stability criteria for situations where a narrow transition zone exists bounded above and below by constant concentrations and within a domain of uniform permeability. Experiments were conducted in a Hele-Shaw cell using a digital imaging technique which provided pixel-scale (similar to 0.2 mm) resolution of the evolving concentration field during convection. Within experimental error, our experiments support both criteria within their predicted ranges of applicability. C1 UNIV NEVADA,DESERT RES INST,RENO,NV 89506. SANDIA NATL LABS,SUBSURFACE FLOW & TRANSPORT PROC LAB,ALBUQUERQUE,NM 87185. UNIV NEVADA,DEPT ENVIRONM & RESOURCES SCI,RENO,NV 89506. RP Cooper, CA (reprint author), UNIV NEVADA,HYDROL SCI PROGRAM,POB 60220,RENO,NV 89506, USA. NR 28 TC 22 Z9 22 U1 1 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0043-1397 J9 WATER RESOUR RES JI Water Resour. Res. PD APR PY 1997 VL 33 IS 4 BP 517 EP 526 DI 10.1029/96WR03811 PG 10 WC Environmental Sciences; Limnology; Water Resources SC Environmental Sciences & Ecology; Marine & Freshwater Biology; Water Resources GA WQ778 UT WOS:A1997WQ77800002 ER PT J AU Roberts, JJ Lin, WN AF Roberts, JJ Lin, WN TI Electrical properties of partially saturated Topopah Spring tuff: Water distribution as a function of saturation SO WATER RESOURCES RESEARCH LA English DT Article ID RESISTIVITY; SANDSTONES; SYSTEMS; ROCK AB We have measured the dielectric constant and electrical resistivity of Topopah Spring tuff as a function of saturation at 23 degrees and 40 degrees C. Dry and saturated resistivities can differ by more than 4 orders of magnitude. Frequency-dependent impedance measurements indicate that the overall electrical response of the rock arises from at least three conduction mechanisms, which we tentatively identify as conduction through adsorbed water on solid surfaces, conduction through isolated pockets of water, and conduction through continuous (bulk) water. The relative contribution of each mechanism varies with saturation. A continuous (bulk) water film is indicated at saturations as low as 35%. Reasonable agreement was found between predicted permeability based on electrical measurements and microstructural parameters using the Kozeny-Carmen relation and experimentally determined permeabilities. Similarly, good agreement was found between estimates of cation exchange capacity (CEC) based on electrical properties through the Waxman and Smits [1968] equation and published CEC values for tuff. RP Roberts, JJ (reprint author), LAWRENCE LIVERMORE NATL LAB,POB 808,L-201,LIVERMORE,CA 94550, USA. NR 31 TC 41 Z9 43 U1 1 U2 5 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0043-1397 J9 WATER RESOUR RES JI Water Resour. Res. PD APR PY 1997 VL 33 IS 4 BP 577 EP 587 DI 10.1029/96WR03905 PG 11 WC Environmental Sciences; Limnology; Water Resources SC Environmental Sciences & Ecology; Marine & Freshwater Biology; Water Resources GA WQ778 UT WOS:A1997WQ77800008 ER PT J AU Bugai, DA Waters, RD Dzhepo, SP Skalskij, AS AF Bugai, DA Waters, RD Dzhepo, SP Skalskij, AS TI The cooling pond of the Chernobyl nuclear power plant: A groundwater remediation case history SO WATER RESOURCES RESEARCH LA English DT Article AB The cooling pond of the Chernobyl nuclear power plant was heavily contaminated as a result of the reactor accident in April 1986. From 1989 to 1993 the cooling pond represented one of the major sources of Sr-90 migration from the Chernobyl site to the Dnieper River. Several attempts have been made to contain radioactive contamination within the pond. Overestimation of releases via groundwater pathway and design mistakes led to unsuccessful remedial actions in 1986 and in later periods. In addition, remediation criteria based solely on comparison of contaminant concentrations in groundwater with drinking water standards were not effective from the health risk perspective, because the public was not directly exposed to contaminated groundwater; the exclusion zone surrounding the site acted as an institutional control to prevent public access. In light of recent estimates of low risks due to radionuclide transport outside the exclusion zone, a ''no action'' approach may represent the most reasonable strategy for the near-term management of the cooling pond. C1 SANDIA NATL LABS,ALBUQUERQUE,NM 87185. RP Bugai, DA (reprint author), NATL ACAD SCI UKRAINE,INST GEOL SCI,GONCHARA ST 55-B,UA-252054 KIEV,UKRAINE. NR 32 TC 3 Z9 3 U1 1 U2 2 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0043-1397 J9 WATER RESOUR RES JI Water Resour. Res. PD APR PY 1997 VL 33 IS 4 BP 677 EP 688 DI 10.1029/96WR03963 PG 12 WC Environmental Sciences; Limnology; Water Resources SC Environmental Sciences & Ecology; Marine & Freshwater Biology; Water Resources GA WQ778 UT WOS:A1997WQ77800016 ER PT J AU Rockhold, ML Simmons, CS Fayer, MJ AF Rockhold, ML Simmons, CS Fayer, MJ TI An analytical solution technique for one-dimensional, steady vertical water flow in layered soils SO WATER RESOURCES RESEARCH LA English DT Article ID HYDRAULIC CONDUCTIVITY; INFILTRATION; MODEL; EQUATION AB An analytical solution technique was developed for one-dimensional, steady vertical water flow in variably saturated, layered soils with arbitrary hydraulic properties. The solution technique is based on the exact integral solution for the Gardner exponential hydraulic conductivity function. The exact solution is extended for use with arbitrary hydraulic property functions, or measured K(h) data, by approximating In K(h) with piecewise-linear curve segments and integrating analytically, segment by segment. The resulting analytical solution technique is accurate, computationally efficient, and applicable to unsaturated and/or saturated conditions. Several application examples are presented, including a comparison with earlier experimental results. C1 PACIFIC NW LAB, DEPT LAND AIR & WATER RESOURCES, RICHLAND, WA USA. RP Rockhold, ML (reprint author), OREGON STATE UNIV, DEPT BIORESOURCE ENGN, 116 GILMORE HALL, CORVALLIS, OR 97331 USA. NR 18 TC 16 Z9 17 U1 1 U2 5 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0043-1397 J9 WATER RESOUR RES JI Water Resour. Res. PD APR PY 1997 VL 33 IS 4 BP 897 EP 902 DI 10.1029/96WR03746 PG 6 WC Environmental Sciences; Limnology; Water Resources SC Environmental Sciences & Ecology; Marine & Freshwater Biology; Water Resources GA WQ778 UT WOS:A1997WQ77800035 ER PT J AU Kodali, P Hawley, M Walter, KC Hubbard, K Yu, N Tesmer, JR Levine, TE Nastasi, M AF Kodali, P Hawley, M Walter, KC Hubbard, K Yu, N Tesmer, JR Levine, TE Nastasi, M TI Tribological properties of carbon- and nitrogen-implanted Si(100) SO WEAR LA English DT Article DE implantation; friction; wear; microstructure; surface hardness; channeling ID SILICON; WEAR AB The knowledge of tribological properties of silicon is important due to its potential application for micromechanical devices. The present work focuses on the friction and wear studies of single crystal silicon (100) implanted with carbon and nitrogen at 60 keV. These tests were performed using a pin-on-disc (POD) apparatus with a 52100 Fin, under contact stress of 225 h MPa and at 35% relative humidity. Changes in surface roughness before and after the wear tests were studied using atomic force microscopy (AFM). Transmission electron microscopy (TEM) investigations and ion-channeling measurements revealed amorphous phases for all the implanted species at all doses. Although the surface hardness measurements performed by nano-indentation indicated no improvement in surface hardness for samples implanted with carbon, the tribological studies indicated an improvement in wear and frictional properties. We relate this improved wear behavior to the formation of amorphous SiC. RP Kodali, P (reprint author), LOS ALAMOS NATL LAB,DIV MAT SCI & TECHNOL,MS K764,POB 1663,LOS ALAMOS,NM 87544, USA. NR 9 TC 10 Z9 15 U1 0 U2 4 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0043-1648 J9 WEAR JI Wear PD APR PY 1997 VL 205 IS 1-2 BP 144 EP 152 DI 10.1016/S0043-1648(96)07290-0 PG 9 WC Engineering, Mechanical; Materials Science, Multidisciplinary SC Engineering; Materials Science GA XF874 UT WOS:A1997XF87400020 ER PT J AU Erdemir, A Halter, M Fenske, GR AF Erdemir, A Halter, M Fenske, GR TI Preparation of ultralow-friction surface films on vanadium diboride SO WEAR LA English DT Article; Proceedings Paper CT 11th International Conference on Wear of Materials CY APR 20-24, 1997 CL SAN DIEGO, CA DE vanadium diboride; flash annealing; ultralow friction ID ACID-FORMING SURFACES; TRIBOLOGICAL PROPERTIES; SELF-LUBRICATION; BORIC-ACID AB In this paper, we present a simple annealing procedure (which we refer to as 'flash annealing' because of its short duration) that results in the formation of an ultralow-friction surface film on vanadium diboride (VB2) surfaces. This annealing is performed in a box furnace at 800 degrees C for a period of 5 min. During annealing, the exposed surface of the VB2 undergoes oxidation and forms a layer of boron oxide (B2O3). In open air, the B2O3 layer reacts spontaneously with moisture and forms a boric acid (H3BO3) film. The friction coefficient of a 440C steel pin against this H3BO3 film is approximately 0.05, compared with 0.8 against the as-received VB2. Based on Raman spectroscopy and electron microscopy studies, we elucidate the ultralow-friction mechanism of the Bash-annealed VB2 surfaces. (C) 1997 Elsevier Science S.A. C1 PURDUE UNIV,DEPT MAT ENGN,W LAFAYETTE,IN. RP Erdemir, A (reprint author), ARGONNE NATL LAB,DIV ENERGY TECHNOL,9700 S CASS AVE,ARGONNE,IL 60439, USA. RI Halter, Michael/F-9795-2011 NR 14 TC 55 Z9 55 U1 0 U2 12 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0043-1648 J9 WEAR JI Wear PD APR PY 1997 VL 205 IS 1-2 BP 236 EP 239 DI 10.1016/S0043-1648(96)07508-4 PG 4 WC Engineering, Mechanical; Materials Science, Multidisciplinary SC Engineering; Materials Science GA XF874 UT WOS:A1997XF87400032 ER PT J AU Mundra, K DebRoy, T Babu, SS David, SA AF Mundra, K DebRoy, T Babu, SS David, SA TI Weld metal microstructure calculations from fundamentals of transport phenomena in the arc welding of low-alloy steels SO WELDING JOURNAL LA English DT Article DE ferrite morphology; fluid flow; fusion zone microstructure; heat transfer; low-alloy steel; manual metal arc welding; TTT diagram; weld pool ID TYPE-304 STAINLESS-STEEL; POOL DEVELOPMENT; PHASE-CHANGE; CONVECTION; GTA; DEPOSITS; MODEL; FLOW AB In recent years, significant progress has been made toward understanding the development of the weld pool shape and size from the numerical calculations of heat transfer and fluid flow in the weld pool. Although such calculations have provided detailed information about the welding processes, no efforts have been made to understand the development of fusion zone microstructures from the fundamentals of transport phenomena. The aim of this work is to address this. Heat transfer and fluid flow during manual metal are welding of low-alloy steels containing different concentrations of vanadium and manganese were investigated by solving the equations of conservation of mass, momentum and energy in three-dimensional transient form. The model incorporates fluid flow in the weld pool resulting from surface tension, electromagnetic and buoyancy forces. The cooling rates are calculated at various locations in the weldment. The weld metal compositions are used to calculate the time-temperature-transformation (TTT) diagrams on the basis of an available phase transformation model. The calculated cooling rates and the TTT diagrams are then coupled to determine the continuous cooling transformation (CCT) behavior and volume percentages of acicular, allotriomorphic and Widmanstatten ferrites in various low-alloy steel weldments. The computed microstructures are found to be in good agreement with the experimentally observed microstructures. The agreement indicates significant promise for predicting weld metal microstructure from the fundamentals of transport phenomena. C1 OAK RIDGE NATL LAB, DIV MET & CERAM, OAK RIDGE, TN USA. RP Mundra, K (reprint author), PENN STATE UNIV, DEPT MAT SCI & ENGN, UNIVERSITY PK, PA 16802 USA. RI Babu, Sudarsanam/D-1694-2010; DebRoy, Tarasankar/A-2106-2010 OI Babu, Sudarsanam/0000-0002-3531-2579; NR 28 TC 40 Z9 40 U1 1 U2 13 PU AMER WELDING SOC PI MIAMI PA 550 N W LEJEUNE RD, MIAMI, FL 33126 USA SN 0043-2296 J9 WELD J JI Weld. J. PD APR PY 1997 VL 76 IS 4 BP S163 EP S171 PG 9 WC Metallurgy & Metallurgical Engineering SC Metallurgy & Metallurgical Engineering GA WR808 UT WOS:A1997WR80800023 ER PT J AU Wimmer, R Lucas, BN Tsui, TY Oliver, WC AF Wimmer, R Lucas, BN Tsui, TY Oliver, WC TI Longitudinal hardness and Young's modulus of spruce tracheid secondary walls using nanoindentation technique SO WOOD SCIENCE AND TECHNOLOGY LA English DT Article ID ELASTIC-MODULUS; INDENTATION; LOAD AB Using a mechanical properties microprobe, measurements of hardness and elastic modulus of tracheid walls in the longitudinal direction of spruce wood were obtained by continuously measuring force and displacement as a diamond indenter impressed a cell wall. Maximum mechanical properties were found at the edges of the walls of angular shaped tracheids. Both the hardness and elastic modulus of latewood cell walls were higher than cell walls in the earlywood. The high spatial resolution of this new concept of mechanical testing allows a direct comparison with ultrastructural and microchemical parameters of lignified cells which opens a wider area of applications for the understanding of intrinsic wood properties. C1 NANO INSTRUMENTS INC,KNOXVILLE,TN 37014. RICE UNIV,DEPT MAT SCI,HOUSTON,TX 77251. OAK RIDGE NATL LAB,OAK RIDGE,TN 37831. RP Wimmer, R (reprint author), UNIV AGR SCI,GREGOR MENDEL STR 33,A-1180 VIENNA,AUSTRIA. NR 40 TC 112 Z9 126 U1 1 U2 22 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 SN 0043-7719 J9 WOOD SCI TECHNOL JI Wood Sci. Technol. PD APR PY 1997 VL 31 IS 2 BP 131 EP 141 PG 11 WC Forestry; Materials Science, Paper & Wood SC Forestry; Materials Science GA XA994 UT WOS:A1997XA99400006 ER PT J AU Breitweg, J Derrick, M Krakauer, D Magill, S Mikunas, D Musgrave, B Repond, J Stanek, R Talaga, RL Yoshida, R Zhang, H Mattingly, MCK Anselmo, F Antonioli, P Bari, G Basile, M Bellagamba, L Boscherini, D Bruni, A Bruni, G Romeo, GC Castellini, G Cifarelli, L Cindolo, F Contin, A Corradi, M DePasquale, S Gialas, I Giusti, P Iacobucci, G Laurenti, G Levi, G Margotti, A Massam, T Nania, R Palmonari, F Pesci, A Polini, A Sartorelli, G Garcia, YZ Zichichi, A Amelung, C Bornheim, A Brock, I Coboken, K Crittenden, J Deffner, R Eckert, M Feld, L Grothe, M Hartmann, H Heinloth, K Heinz, L Hilger, E Jakob, HP Katz, UF Paul, E Pfeiffer, M Rembser, C Stamm, J Wedemeyer, R Bailey, DS CampbellRobson, S Cottingham, WN Foster, B HallWilton, R Hayes, ME Heath, GP Heath, HF Piccioni, D Roff, DG Tapper, RJ Arneodo, M Ayad, R Capua, M Garfagnini, A Iannotti, L Schioppa, M Susinno, G Kim, JY Lee, JH Lim, IT Pac, MY Caldwell, A Cartiglia, N Jing, Z Liu, W Parsons, JA Ritz, S Sampson, S Sciulli, F Straub, PB Zhu, Q Borzemski, P Chwastowski, J Eskreys, A Jakubowski, Z Przybycien, MB Zachara, M Zawiejski, L Adamczyk, L Bednarek, B Jelen, K Kisielewska, D Kowalski, T Przybycieo, M RulikowskaZarebska, E Suszycki, L Zajac, J Dulinski, Z Kotanski, A Abbiendi, G Bauerdick, LAT Behrens, U Beier, H Bienlein, JK Cases, G Deppe, O Desler, K Drews, G Gilkinson, DJ Glasman, C Gottlicher, P GrosseKnetter, J Haas, T Hain, W Hasell, D Hessling, H Iga, Y Johnson, KF Kasemann, M Koch, W Kotz, U Kowalski, H Labs, J Lindemann, L Lohr, B Lowe, M Mainusch, J Manczak, O Milewski, J Monteiro, T Ng, JST Notz, D Ohrenberg, K Park, JH Pellegrino, A Pelucchi, F Piotrkowski, K Roco, M Rohde, M Roldan, J Savin, AA Schneekloth, U Schulz, W Selonke, F Surrow, B Tassi, E Voss, T Westphal, D Wolf, G Wollmer, U Youngman, C Zarnecki, AF Zeuner, W Burow, BD Grabosch, HJ Meyer, A Schlenstedt, S Barbagli, G Gallo, E Pelfer, P Maccarrone, G Votano, L Bamberger, A Eisenhardt, S Markun, P Trefzger, T Wolfle, S Bromley, JT Brook, NH Bussey, PJ Doyle, AT Saxon, DH Sinclair, LE Strickland, E Utley, ML Waugh, R Wilson, AS Bohnet, I Gendner, N Holm, U MeyerLarsen, A Salehi, H Wick, K Gladilin, LK Klanner, R Lohrmann, E Poelz, G Schott, W Zetsche, F Bacon, TC Butterworth, I Cole, JE Harris, VL Howell, G Hung, BHY Lamberti, L Long, KR Miller, DB Pavel, N Prinias, A Sedgbeer, JK Sideris, D Whitfield, AF Mallik, U Wang, SM Wu, JT Cloth, P Filges, D An, SH Lee, SB Nam, SW Park, HS Park, SK Barreiro, F Fernandez, JP Graciani, R Hernandez, JM Hervas, L Labarga, L Martinez, M delPeso, J Puga, J Terron, J deTroconiz, JF Corriveau, F Hanna, DS Hartmann, J Hung, LW Lim, JN Murray, WN Ochs, A Riveline, M Stairs, DG StLaurent, M Ullmann, R Tsurugai, T Bashkirov, V Dolgoshein, BA Stifutkin, A Bashindzhagyan, GL Ermolov, PF Golubkov, YA Kobrin, VD Korzhavina, LA Kuzmin, VA Lukina, OY Proskuryakov, AS Shcheglova, LM Solomin, AN Zotov, NP Bokel, C Botje, M Brummer, N Chlebana, F Engelen, J deKamps, M Kooijman, P Kruse, A vanSighem, A Tiecke, H Verkerke, W Vossebeld, J Vreeswijk, M Wiggers, L deWolf, E Acosta, D Bylsma, B Durkin, LS Gilmore, J Ginsburg, CH Kim, CL Ling, TY Nylander, P Romanowski, TA Blaikley, HE Cashmore, RJ CooperSarkar, AM Devenish, RCE Edmonds, JK Harnew, N Lancaster, M McFall, JD Nath, C Noyes, VA Quadt, A Tickner, JR Uijterwaal, H Walczak, R Waters, DS Yip, T Bertolin, A Brugnera, R Carlin, R DalCorso, F Dosselli, U Limentani, S Morandin, M Posocco, M Stanco, L Stroili, R Voci, C Bulmahn, J Feild, RG Oh, BY Okrasinski, JR Whitmore, JJ Marini, G Nigro, A Hart, JC McCubbin, NA Shah, TP Barberis, E Dubbs, T Heusch, C VanHook, M Lockman, W Rahn, JT Sadrozinski, HFW Seiden, A Williams, DC Schwarzer, O Walenta, AH Abramowicz, H Briskin, G Dagan, S Doeker, T Kananov, S Levy, A Abe, T Fleck, JI Inuzuka, M Ishii, T Kuze, M Nagano, K Nakao, M Suzuki, I Tokushuku, K Umemori, K Yamada, S Yamazaki, Y Hamatsu, R Hirose, T Homma, K Kitamura, S Matsushita, T Yamauchi, K Cirio, R Costa, M Ferrero, MI Maselli, S Monaco, V Peroni, C Petrucci, MC Sacchi, R Solano, A Staiano, A Dardo, M Bailey, DC Brkic, M Fagerstroem, CP Hartner, GF Joe, KK Levman, GM Martin, JF Orr, RS Polenz, S Sampson, CR Simmons, D Teuscher, RJ Butterworth, JM Catterall, CD Jones, TW Kaziewicz, PB Lane, JB Saunders, RL Shulman, J Sutton, MR Lu, B Mo, LW Ciborowski, J Grzelak, G Kasprzak, M Muchorowski, K Nowak, RJ Pawlak, JM Pawlak, R Tymieniecka, T Wroblewski, AK Zakrzewski, JA Adamus, M Coldewey, C Eisenberg, Y Hochman, D Karshon, U Revel, D Badgett, WF Chapin, D Cross, R Dasu, S Foudas, C Loveless, RJ Mattingly, S Reeder, DD Smith, WH Vaiciulis, A Wodarczyk, M Bhadra, S Frisken, WR Khakzad, M Schmidke, WB AF Breitweg, J Derrick, M Krakauer, D Magill, S Mikunas, D Musgrave, B Repond, J Stanek, R Talaga, RL Yoshida, R Zhang, H Mattingly, MCK Anselmo, F Antonioli, P Bari, G Basile, M Bellagamba, L Boscherini, D Bruni, A Bruni, G Romeo, GC Castellini, G Cifarelli, L Cindolo, F Contin, A Corradi, M DePasquale, S Gialas, I Giusti, P Iacobucci, G Laurenti, G Levi, G Margotti, A Massam, T Nania, R Palmonari, F Pesci, A Polini, A Sartorelli, G Garcia, YZ Zichichi, A Amelung, C Bornheim, A Brock, I Coboken, K Crittenden, J Deffner, R Eckert, M Feld, L Grothe, M Hartmann, H Heinloth, K Heinz, L Hilger, E Jakob, HP Katz, UF Paul, E Pfeiffer, M Rembser, C Stamm, J Wedemeyer, R Bailey, DS CampbellRobson, S Cottingham, WN Foster, B HallWilton, R Hayes, ME Heath, GP Heath, HF Piccioni, D Roff, DG Tapper, RJ Arneodo, M Ayad, R Capua, M Garfagnini, A Iannotti, L Schioppa, M Susinno, G Kim, JY Lee, JH Lim, IT Pac, MY Caldwell, A Cartiglia, N Jing, Z Liu, W Parsons, JA Ritz, S Sampson, S Sciulli, F Straub, PB Zhu, Q Borzemski, P Chwastowski, J Eskreys, A Jakubowski, Z Przybycien, MB Zachara, M Zawiejski, L Adamczyk, L Bednarek, B Jelen, K Kisielewska, D Kowalski, T Przybycieo, M RulikowskaZarebska, E Suszycki, L Zajac, J Dulinski, Z Kotanski, A Abbiendi, G Bauerdick, LAT Behrens, U Beier, H Bienlein, JK Cases, G Deppe, O Desler, K Drews, G Gilkinson, DJ Glasman, C Gottlicher, P GrosseKnetter, J Haas, T Hain, W Hasell, D Hessling, H Iga, Y Johnson, KF Kasemann, M Koch, W Kotz, U Kowalski, H Labs, J Lindemann, L Lohr, B Lowe, M Mainusch, J Manczak, O Milewski, J Monteiro, T Ng, JST Notz, D Ohrenberg, K Park, JH Pellegrino, A Pelucchi, F Piotrkowski, K Roco, M Rohde, M Roldan, J Savin, AA Schneekloth, U Schulz, W Selonke, F Surrow, B Tassi, E Voss, T Westphal, D Wolf, G Wollmer, U Youngman, C Zarnecki, AF Zeuner, W Burow, BD Grabosch, HJ Meyer, A Schlenstedt, S Barbagli, G Gallo, E Pelfer, P Maccarrone, G Votano, L Bamberger, A Eisenhardt, S Markun, P Trefzger, T Wolfle, S Bromley, JT Brook, NH Bussey, PJ Doyle, AT Saxon, DH Sinclair, LE Strickland, E Utley, ML Waugh, R Wilson, AS Bohnet, I Gendner, N Holm, U MeyerLarsen, A Salehi, H Wick, K Gladilin, LK Klanner, R Lohrmann, E Poelz, G Schott, W Zetsche, F Bacon, TC Butterworth, I Cole, JE Harris, VL Howell, G Hung, BHY Lamberti, L Long, KR Miller, DB Pavel, N Prinias, A Sedgbeer, JK Sideris, D Whitfield, AF Mallik, U Wang, SM Wu, JT Cloth, P Filges, D An, SH Lee, SB Nam, SW Park, HS Park, SK Barreiro, F Fernandez, JP Graciani, R Hernandez, JM Hervas, L Labarga, L Martinez, M delPeso, J Puga, J Terron, J deTroconiz, JF Corriveau, F Hanna, DS Hartmann, J Hung, LW Lim, JN Murray, WN Ochs, A Riveline, M Stairs, DG StLaurent, M Ullmann, R Tsurugai, T Bashkirov, V Dolgoshein, BA Stifutkin, A Bashindzhagyan, GL Ermolov, PF Golubkov, YA Kobrin, VD Korzhavina, LA Kuzmin, VA Lukina, OY Proskuryakov, AS Shcheglova, LM Solomin, AN Zotov, NP Bokel, C Botje, M Brummer, N Chlebana, F Engelen, J deKamps, M Kooijman, P Kruse, A vanSighem, A Tiecke, H Verkerke, W Vossebeld, J Vreeswijk, M Wiggers, L deWolf, E Acosta, D Bylsma, B Durkin, LS Gilmore, J Ginsburg, CH Kim, CL Ling, TY Nylander, P Romanowski, TA Blaikley, HE Cashmore, RJ CooperSarkar, AM Devenish, RCE Edmonds, JK Harnew, N Lancaster, M McFall, JD Nath, C Noyes, VA Quadt, A Tickner, JR Uijterwaal, H Walczak, R Waters, DS Yip, T Bertolin, A Brugnera, R Carlin, R DalCorso, F Dosselli, U Limentani, S Morandin, M Posocco, M Stanco, L Stroili, R Voci, C Bulmahn, J Feild, RG Oh, BY Okrasinski, JR Whitmore, JJ Marini, G Nigro, A Hart, JC McCubbin, NA Shah, TP Barberis, E Dubbs, T Heusch, C VanHook, M Lockman, W Rahn, JT Sadrozinski, HFW Seiden, A Williams, DC Schwarzer, O Walenta, AH Abramowicz, H Briskin, G Dagan, S Doeker, T Kananov, S Levy, A Abe, T Fleck, JI Inuzuka, M Ishii, T Kuze, M Nagano, K Nakao, M Suzuki, I Tokushuku, K Umemori, K Yamada, S Yamazaki, Y Hamatsu, R Hirose, T Homma, K Kitamura, S Matsushita, T Yamauchi, K Cirio, R Costa, M Ferrero, MI Maselli, S Monaco, V Peroni, C Petrucci, MC Sacchi, R Solano, A Staiano, A Dardo, M Bailey, DC Brkic, M Fagerstroem, CP Hartner, GF Joe, KK Levman, GM Martin, JF Orr, RS Polenz, S Sampson, CR Simmons, D Teuscher, RJ Butterworth, JM Catterall, CD Jones, TW Kaziewicz, PB Lane, JB Saunders, RL Shulman, J Sutton, MR Lu, B Mo, LW Ciborowski, J Grzelak, G Kasprzak, M Muchorowski, K Nowak, RJ Pawlak, JM Pawlak, R Tymieniecka, T Wroblewski, AK Zakrzewski, JA Adamus, M Coldewey, C Eisenberg, Y Hochman, D Karshon, U Revel, D Badgett, WF Chapin, D Cross, R Dasu, S Foudas, C Loveless, RJ Mattingly, S Reeder, DD Smith, WH Vaiciulis, A Wodarczyk, M Bhadra, S Frisken, WR Khakzad, M Schmidke, WB TI Comparison of ZEUS data with standard model predictions for e(+)p->e(+)X scattering at high x and Q(2) SO ZEITSCHRIFT FUR PHYSIK C-PARTICLES AND FIELDS LA English DT Article ID DEUTERON STRUCTURE FUNCTIONS; HIGH STATISTICS MEASUREMENT; INELASTIC MUON SCATTERING; CENTRAL TRACKING DETECTOR; ENERGY EP COLLISIONS; PARTON DISTRIBUTIONS; CROSS-SECTIONS; BARREL CALORIMETER; HIGH Q2; PROTON AB Using the ZEUS detector at HERA, we have studied the reaction e(+)p --> e(+)X for Q(2) > 5000 GeV2 with a 20.1 pb(-1) data sample collected during the years 1993 to 1996. For Q(2) below 15000 GeV2, the data are in good agreement with Standard Model expectations. For Q(2) > 35000 GeV2. two events are observed while 0.145 +/- 0.013 events are expected, A statistical analysis of a large ensemble of simulated Standard Model experiments indicates that with probability 6.0%, an excess at least as unlikely as that observed would occur above some Q(2) cut. For x > 0.55 and y > 0.75, four events are observed where 0.91 +/- 0.08 events are expected, A statistical analysis of the two-dimensional distribution of the events in x and y yields a probability of 0.72% for the region x > 0.55 and y > 0.25 and a probability of 7.8% for the entire Q(2) > 5000 GeV2 data sample. The observed excess above Standard Model expectations is particularly interesting because it occurs in a previously unexplored kinematic region. C1 ANDREWS UNIV, BERRIEN SPRINGS, MI 49104 USA. UNIV BOLOGNA, I-40126 BOLOGNA, ITALY. IST NAZL FIS NUCL, I-40126 BOLOGNA, ITALY. UNIV BONN, INST PHYS, D-53115 BONN, GERMANY. UNIV BRISTOL, HH WILLS PHYS LAB, BRISTOL BS8 1TL, AVON, ENGLAND. IST NAZL FIS NUCL, COSENZA, ITALY. UNIV CALABRIA, DEPT PHYS, I-87036 COSENZA, ITALY. CHONNAM NATL UNIV, KWANGJU, SOUTH KOREA. COLUMBIA UNIV, NEVIS LABS, IRVINGTON, NY 10533 USA. INST NUCL PHYS, PL-30055 KRAKOW, POLAND. ACAD MIN & MET, FAC PHYS & NUCL TECH, PL-30055 KRAKOW, POLAND. JAGIELLONIAN UNIV, DEPT PHYS, PL-30059 KRAKOW, POLAND. DESY, D-22603 HAMBURG, GERMANY. DESY, IFH ZEUTHEN, D-15738 ZEUTHEN, GERMANY. UNIV FLORENCE, FLORENCE, ITALY. IST NAZL FIS NUCL, FLORENCE, ITALY. IST NAZL FIS NUCL, LAB NAZL FRASCATI, I-00044 FRASCATI, ITALY. UNIV FREIBURG, FAK PHYS, D-79104 FREIBURG, GERMANY. UNIV GLASGOW, DEPT PHYS & ASTRON, GLASGOW G12 8QQ, LANARK, SCOTLAND. UNIV HAMBURG, INST EXPT PHYS 1, D-22761 HAMBURG, GERMANY. UNIV HAMBURG, INST EXPT PHYS 2, D-22761 HAMBURG, GERMANY. UNIV LONDON IMPERIAL COLL SCI TECHNOL & MED, HIGH ENERGY NUCL PHYS GRP, LONDON SW7 3BZ, ENGLAND. UNIV IOWA, DEPT PHYS & ASTRON, IOWA CITY, IA 52242 USA. FORSCHUNGSZENTRUM JULICH, INST KERNPHYS, D-52405 JULICH, GERMANY. KOREA UNIV, SEOUL 136701, SOUTH KOREA. UNIV AUTONOMA MADRID, DEPT FIS TEOR, E-28049 MADRID, SPAIN. MCGILL UNIV, DEPT PHYS, MONTREAL, PQ H3A 2T8, CANADA. MEIJI GAKUIN UNIV, FAC GEN EDUC, YOKOHAMA, KANAGAWA 244, JAPAN. MOSCOW PHYS ENGN INST, RU-115409 MOSCOW, RUSSIA. MOSCOW MV LOMONOSOV STATE UNIV, INST NUCL PHYS, RU-119899 MOSCOW, RUSSIA. NIKHEF H, NL-1009 DB AMSTERDAM, NETHERLANDS. UNIV AMSTERDAM, NL-1009 DB AMSTERDAM, NETHERLANDS. OHIO STATE UNIV, DEPT PHYS, COLUMBUS, OH 43210 USA. UNIV OXFORD, DEPT PHYS, OXFORD OX1 BNP, ENGLAND. UNIV PADUA, DIPARTIMENTO FIS, I-35131 PADUA, ITALY. IST NAZL FIS NUCL, I-35131 PADUA, ITALY. PENN STATE UNIV, DEPT PHYS, UNIVERSITY PK, PA 16802 USA. UNIV ROMA LA SAPIENZA, DIPARTIMENTO FIS, I-00815 ROME, ITALY. IST NAZL FIS NUCL, I-00815 ROME, ITALY. RUTHERFORD APPLETON LAB, DIDCOT OX11 0QX, OXON, ENGLAND. UNIV CALIF SANTA CRUZ, SANTA CRUZ, CA 95046 USA. UNIV GESAMTHSCH SIEGEN, FACHBEREICH PHYS, D-57012 SIEGEN, GERMANY. TEL AVIV UNIV, SCH PHYS, RAYMOND & BEVERLY SACKLER FAC EXACT SCI, IL-69978 TEL AVIV, ISRAEL. UNIV TOKYO, INST NUCL STUDY, TOKYO 188, JAPAN. TOKYO METROPOLITAN UNIV, DEPT PHYS, TOKYO 19203, JAPAN. IST NAZL FIS NUCL, I-10125 TURIN, ITALY. UNIV TURIN, DIPARTIMENTO FIS SPERIMENTALE, I-10125 TURIN, ITALY. UNIV TURIN, FAC SCI 2, I-10125 TURIN, ITALY. UNIV TORONTO, DEPT PHYS, TORONTO, ON M5S 1A7, CANADA. UCL, DEPT PHYS & ASTRON, LONDON WC1E 6BT, ENGLAND. VIRGINIA POLYTECH INST & STATE UNIV, BLACKSBURG, VA 24061 USA. UNIV WARSAW, INST EXPT PHYS, PL-00681 WARSAW, POLAND. INST NUCL STUDIES, PL-00681 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 M3J 1P3, CANADA. CNR, IROE, I-50127 FLORENCE, ITALY. RP Breitweg, J (reprint author), ARGONNE NATL LAB, 9700 S CASS AVE, ARGONNE, IL 60439 USA. RI Solomin, Anatoly/C-3072-2016; Graciani Diaz, Ricardo/I-5152-2016; Capua, Marcella/A-8549-2015; Bashkirov, Vladimir/A-4818-2008; Tassi, Enrico/K-3958-2015; Gladilin, Leonid/B-5226-2011; Morandin, Mauro/A-3308-2016; De Pasquale, Salvatore/B-9165-2008; Lancaster, Mark/C-1693-2008; Doyle, Anthony/C-5889-2009; Golubkov, Yury/E-1643-2012; Proskuryakov, Alexander/J-6166-2012; Katz, Uli/E-1925-2013; Wiggers, Leo/B-5218-2015; Hernandez Calama, Jose Maria/H-9127-2015 OI Graciani Diaz, Ricardo/0000-0001-7166-5198; Castellini, Guido/0000-0002-0177-0643; Capua, Marcella/0000-0002-2443-6525; Lancaster, Mark/0000-0002-8872-7292; Gladilin, Leonid/0000-0001-9422-8636; Morandin, Mauro/0000-0003-4708-4240; De Pasquale, Salvatore/0000-0001-9236-0748; Doyle, Anthony/0000-0001-6322-6195; Katz, Uli/0000-0002-7063-4418; Wiggers, Leo/0000-0003-1060-0520; Hernandez Calama, Jose Maria/0000-0001-6436-7547 NR 46 TC 232 Z9 232 U1 0 U2 5 PU SPRINGER PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 0170-9739 J9 Z PHYS C PART FIELDS JI Z. Phys. C-Part. Fields PD APR PY 1997 VL 74 IS 2 BP 207 EP 220 DI 10.1007/s002880050384 PG 14 WC Physics, Particles & Fields SC Physics GA WZ519 UT WOS:A1997WZ51900002 ER PT J AU Adams, MR Aderholz, M Aid, S Anthony, PL Averill, DA Baker, MD Baller, BR Banerjee, A Braun, HM Carroll, TJ Clark, HL Conrad, JM Davisson, R Derado, I Bhatti, AA Bratzler, U Dietrich, FS Dougherty, W Dreyer, T Eckardt, V Ecker, U Erdmann, M Fang, GY Figiel, J Finlay, RW Gebauer, HJ Geesaman, DF Griffioen, KA Guo, RS Haas, J Halliwell, C Hantke, D Jaffe, DE Jancso, G Jansen, DM Jin, Z Kadija, K Kaufmann, S Hicks, KH Jackson, HE Kennedy, RD Kinney, ER Kobrak, HGE Kotwal, AV Kunori, S Lord, JJ Lubatti, HJ McLeod, D Madden, P Magill, S Manz, A Melanson, H Michael, DG Montgomery, HE Morfin, JG Nickerson, RB Novak, J Olkiewicz, K Osborne, L Otten, R Papavassiliou, V Pawlik, B Pipkin, FM Potterveld, DH Roser, A Ryan, JJ Salgado, CW Schellman, H Schmitt, M Schmitz, N Schuler, KP Siegert, G Skuja, A Snow, GA SoldnerRembold, S Spentzouris, P Stopa, P Swanson, RA Venkataramania, H Wilhelm, M Wilson, R Wittek, W Wolbers, SA Zeller, GP Zghiche, A Zhao, T AF Adams, MR Aderholz, M Aid, S Anthony, PL Averill, DA Baker, MD Baller, BR Banerjee, A Braun, HM Carroll, TJ Clark, HL Conrad, JM Davisson, R Derado, I Bhatti, AA Bratzler, U Dietrich, FS Dougherty, W Dreyer, T Eckardt, V Ecker, U Erdmann, M Fang, GY Figiel, J Finlay, RW Gebauer, HJ Geesaman, DF Griffioen, KA Guo, RS Haas, J Halliwell, C Hantke, D Jaffe, DE Jancso, G Jansen, DM Jin, Z Kadija, K Kaufmann, S Hicks, KH Jackson, HE Kennedy, RD Kinney, ER Kobrak, HGE Kotwal, AV Kunori, S Lord, JJ Lubatti, HJ McLeod, D Madden, P Magill, S Manz, A Melanson, H Michael, DG Montgomery, HE Morfin, JG Nickerson, RB Novak, J Olkiewicz, K Osborne, L Otten, R Papavassiliou, V Pawlik, B Pipkin, FM Potterveld, DH Roser, A Ryan, JJ Salgado, CW Schellman, H Schmitt, M Schmitz, N Schuler, KP Siegert, G Skuja, A Snow, GA SoldnerRembold, S Spentzouris, P Stopa, P Swanson, RA Venkataramania, H Wilhelm, M Wilson, R Wittek, W Wolbers, SA Zeller, GP Zghiche, A Zhao, T TI Diffractive production of rho(0)(770) mesons in muon-proton interactions at 470 GeV SO ZEITSCHRIFT FUR PHYSIK C-PARTICLES AND FIELDS LA English DT Article ID DEEP-INELASTIC-SCATTERING; VECTOR-MESONS; HADRONIC PROPERTIES; COLOR TRANSPARENCY; POMERON STRUCTURE; EXCLUSIVE RHO(0); CROSS-SECTIONS; PHOTOPRODUCTION; PHOTON; DISSOCIATION AB The diffractive production of rho(0)(770) mesons in muon-proton interactions is studied in the kinematic region 0.15 GeV2 < Q(2) < 20 GeV2 and 20 GeV < nu < 420 GeV. The data were obtained in the Fermilab fixed-target experiment E665 with primary muons of 470 GeV Energy. Results are presented on the Q(2), x and nu dependence of the cross section, on the share of the pi(+)pi(-) mass spectrum, on the slope of the diffraction peak and on the production and decay angular distributions of the rho(0)(770). The cross section for diffractive production of rho(0) by virtual photons on protons depends mainly on Q(2). At fixed Q(2), no significant dependence on x or nu is observed. The extrapolation to Q(2) = 0 yields a photoproduction cross section of (10.30 +/- 0.33) mu b. The slope of the t' distribution has a value of (7.0 +/- 0.2) GeV-2, with a tendency to decrease as Q(2) increases. The production and decay angular distributions of the rho(0) depend strongly on Q(2) and are consistent with s-channel helicity conservation. The ratio R = sigma(L)/sigma(T) deduced from the decay angular distributions rises strongly with Q(2), passing the value of I at Q(2) approximate to 2 GeV2. C1 UNIV FREIBURG, D-79104 FREIBURG, GERMANY. ARGONNE NATL LAB, ARGONNE, IL 60439 USA. UNIV CALIF SAN DIEGO, SAN DIEGO, CA 92093 USA. FERMILAB NATL ACCELERATOR LAB, BATAVIA, IL 60510 USA. HARVARD UNIV, CAMBRIDGE, MA 02138 USA. KFKI RES INST PARTICLE & NUCL PHYS, H-1525 BUDAPEST, HUNGARY. INST NUCL PHYS, PL-30055 KRAKOW, POLAND. LAWRENCE LIVERMORE NATL LAB, LIVERMORE, CA 94551 USA. UNIV MARYLAND, COLLEGE PK, MD 20742 USA. MIT, CAMBRIDGE, MA 02139 USA. MAX PLANCK INST PHYS & ASTROPHYS, D-80805 MUNICH, GERMANY. NORTHWESTERN UNIV, EVANSTON, IL 60208 USA. OHIO UNIV, ATHENS, OH 45701 USA. UNIV PENN, PHILADELPHIA, PA 19104 USA. UNIV WASHINGTON, SEATTLE, WA 98195 USA. BERG UNIV GESAMTHSCH WUPPERTAL, D-42097 WUPPERTAL, GERMANY. YALE UNIV, NEW HAVEN, CT 06511 USA. RP UNIV ILLINOIS, CHICAGO, IL 60680 USA. RI Carroll, Timothy/B-6934-2009 NR 78 TC 81 Z9 81 U1 0 U2 1 PU SPRINGER PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 0170-9739 J9 Z PHYS C PART FIELDS JI Z. Phys. C-Part. Fields PD APR PY 1997 VL 74 IS 2 BP 237 EP 261 DI 10.1007/s002880050386 PG 25 WC Physics, Particles & Fields SC Physics GA WZ519 UT WOS:A1997WZ51900004 ER PT J AU Chikkatur, AP Bugel, L Alton, A Arroyo, CG Avvakumov, S Auchincloss, P deBarbaro, L deBarbaro, P Bazarko, AO Bernstein, RH Bolton, T Bodek, A Brau, J Budd, H Conrad, J Drucker, RB Goldman, J Harris, DA Johnson, RA Kim, JH Kinnel, T Koutsoliotas, S Lamm, MJ Lefmann, WC Lowery, WB Marsh, W McFarland, KS McNulty, C Mishra, SR Naples, D Nienaber, P Oreglia, MJ Perera, L Quintas, PZ Romosan, A Sakumoto, WK Schellman, H Schumm, BA Sciulli, FJ Seligman, WG Shaevitz, MH Smith, WH Spentzouris, P Steiner, R Stern, EG Vaitaitis, A Vakili, M Yang, UK Woods, D Yu, J Zeller, S AF Chikkatur, AP Bugel, L Alton, A Arroyo, CG Avvakumov, S Auchincloss, P deBarbaro, L deBarbaro, P Bazarko, AO Bernstein, RH Bolton, T Bodek, A Brau, J Budd, H Conrad, J Drucker, RB Goldman, J Harris, DA Johnson, RA Kim, JH Kinnel, T Koutsoliotas, S Lamm, MJ Lefmann, WC Lowery, WB Marsh, W McFarland, KS McNulty, C Mishra, SR Naples, D Nienaber, P Oreglia, MJ Perera, L Quintas, PZ Romosan, A Sakumoto, WK Schellman, H Schumm, BA Sciulli, FJ Seligman, WG Shaevitz, MH Smith, WH Spentzouris, P Steiner, R Stern, EG Vaitaitis, A Vakili, M Yang, UK Woods, D Yu, J Zeller, S TI Tests of a calorimetric technique for measuring the energy of cosmic ray muons in the TeV energy range SO ZEITSCHRIFT FUR PHYSIK C-PARTICLES AND FIELDS LA English DT Article AB Previous energy measurements of cosmic ray muons have used magnetic spectrometers to measure the momentum of muons. Measurements using magnets fail for muons in the TeV range because at ultra-high muon energies, the measurement error in the angular deflection of muons by the spectrometer becomes comparable to the total angular defection. A new method for measuring the energies of TeV muons is investigated, using a sample of cosmic ray muons accumulated parasitically (or synergistically) by the CCFR neutrino detector. The method infers the muon energy from measurements of the energy deposited by the muon in many layers of an iron-scintillator calorimeter. Muons in the TeV energy range lose energy stochastically through e(+)e(-) pair production. The distribution of muon energy loss is used to estimate the most likely muon energy. The analysis suggests that this new method for measuring cosmic ray muon energy may be applicable in future detectors such as MINOS and AMANDA. C1 ADELPHI UNIV,DEPT PHYS,GARDEN CITY,NY 11530. UNIV CHICAGO,DEPT PHYS,CHICAGO,IL 60637. UNIV CINCINNATI,DEPT PHYS,CINCINNATI,OH 45221. COLUMBIA UNIV,DEPT PHYS,NEW YORK,NY 10027. FERMILAB NATL ACCELERATOR LAB,BATAVIA,IL 60510. KANSAS STATE UNIV,DEPT PHYS,MANHATTAN,KS 66506. NORTHWESTERN UNIV,DEPT PHYS,EVANSTON,IL 60208. UNIV OREGON,DEPT PHYS,EUGENE,OR 97403. UNIV WISCONSIN,DEPT PHYS,MADISON,WI 53706. XAVIER UNIV,DEPT PHYS,CINCINNATI,OH 45207. RP Chikkatur, AP (reprint author), UNIV ROCHESTER,DEPT PHYS,ROCHESTER,NY 14627, USA. OI Bernstein, Robert/0000-0002-7610-950X NR 11 TC 3 Z9 3 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 APR PY 1997 VL 74 IS 2 BP 279 EP 289 DI 10.1007/s002880050389 PG 11 WC Physics, Particles & Fields SC Physics GA WZ519 UT WOS:A1997WZ51900007 ER PT J AU Sirmain, G Reichertz, LA Dubon, OD Haller, EE Hansen, WL Brundermann, E Linhart, AM Roser, HP AF Sirmain, G Reichertz, LA Dubon, OD Haller, EE Hansen, WL Brundermann, E Linhart, AM Roser, HP TI Stimulated far-infrared emission from copper-doped germanium crystals SO APPLIED PHYSICS LETTERS LA English DT Article ID SPECTRA AB We have detected stimulated far-infrared emission from copper-doped germanium single crystals. By varying the magnetic field between 1 and 2.3 T, we have achieved emission in the range of 70-120 cm(-1). Laser action was observed for crystals with a copper acceptor concentration as high as 1.5 x 10(15) cm(-3), a doping level that is considerably higher than that of any single or double acceptor doped Ge laser. Stimulated emission from Ge crystals with such a high Cu concentration is possible because only a small fraction of the copper accepters is ionized during operation. (C) 1997 American Institute of Physics. C1 EUROPEAN SPACE AGCY,F-75738 PARIS,FRANCE. DLR,INST SPACE SENSOR TECHNOL,D-12489 BERLIN,GERMANY. UNIV CALIF BERKELEY,DEPT MAT SCI & MINERAL ENGN,BERKELEY,CA 94720. RP Sirmain, G (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,BERKELEY,CA 94720, USA. RI Bruendermann, Erik/J-7186-2016 OI Bruendermann, Erik/0000-0003-4119-3489 NR 15 TC 14 Z9 14 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD MAR 31 PY 1997 VL 70 IS 13 BP 1659 EP 1661 DI 10.1063/1.118662 PG 3 WC Physics, Applied SC Physics GA WT571 UT WOS:A1997WT57100008 ER PT J AU Ejeckam, FE Lo, YH Subramanian, S Hou, HQ Hammons, BE AF Ejeckam, FE Lo, YH Subramanian, S Hou, HQ Hammons, BE TI Lattice engineered compliant substrate for defect-free heteroepitaxial growth SO APPLIED PHYSICS LETTERS LA English DT Article ID PSEUDOMORPHIC STRUCTURES; CRITICAL THICKNESS AB Presented here is proof-of-principle that a thin single crystal semiconductor film-when twist-wafer bonded to a bulk single crystal substrate (of the same material)-will comply to the lattice constant of a different single crystal semiconductor thick film grown on its surface. In our experiment, a 100 Angstrom film of GaAs was wafer bonded to a GaAs bulk substrate, with a large twist angle between their [110] directions. The resultant twist boundary ensures high flexibility in the thin film. Dislocation-free films of In0.35Ga0.65P(similar to 1% strain) were grown with thicknesses of 3000 Angstrom, thirty times the Matthews-Blakeslee critical thickness, on twist-wafer-bonded films of GaAs. (C) 1997 American Institute of Physics. C1 SANDIA NATL LABS,DEPT SEMICOND MAT,ALBUQUERQUE,NM 87185. CORNELL UNIV,DEPT MAT SCI & ENGN,ITHACA,NY 14853. RP Ejeckam, FE (reprint author), CORNELL UNIV,SCH ELECT ENGN,PHILLIPS HALL,ITHACA,NY 14853, USA. NR 7 TC 117 Z9 118 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 MAR 31 PY 1997 VL 70 IS 13 BP 1685 EP 1687 DI 10.1063/1.118669 PG 3 WC Physics, Applied SC Physics GA WT571 UT WOS:A1997WT57100017 ER PT J AU Geyer, U vonHulsen, U Thiyagarajan, P AF Geyer, U vonHulsen, U Thiyagarajan, P TI Surface roughening and columnar growth of thin amorphous CuTi films SO APPLIED PHYSICS LETTERS LA English DT Article ID METAL ALLOY-FILMS; DIFFUSION-BARRIERS; STRESSES AB Different growth stages and the microstructure of amorphous CuTi films are investigated by scanning tunneling microscopy and small angle neutron scattering. During film growth at room temperature, the initially smooth films show increasing surface roughening and finally a change to a columnar growth mode with column diameters of about 20 nm. The interfacial energies associated with the column boundaries are higher than those of grain boundaries in crystalline systems. The column boundaries might be the origin of high intrinsic tensile stresses measured before in the amorphous CuTi films. (C) 1997 American Institute of Physics. C1 UNIV GOTTINGEN,SONDERFORSCH BEREICH 345,D-37073 GOTTINGEN,GERMANY. ARGONNE NATL LAB,INTENSE PULSED NEUTRON SOURCE,ARGONNE,IL 60439. RP Geyer, U (reprint author), UNIV GOTTINGEN,INST PHYS 1,D-37073 GOTTINGEN,GERMANY. NR 14 TC 13 Z9 13 U1 1 U2 2 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD MAR 31 PY 1997 VL 70 IS 13 BP 1691 EP 1693 DI 10.1063/1.118671 PG 3 WC Physics, Applied SC Physics GA WT571 UT WOS:A1997WT57100019 ER PT J AU Price, DL Saboungi, ML AF Price, DL Saboungi, ML TI Physics in the fast lane: Rotors, fast ions and mobile fermions SO JOURNAL OF PHYSICS-CONDENSED MATTER LA English DT Article; Proceedings Paper CT Conference on the Physics and Chemistry of Conducting Liquids CY APR 18, 1996 CL BRISTOL, ENGLAND ID METAL LEAD ALLOYS; CSPB; ENHANCEMENT; KPB AB Dynamic disorder in the high-temperature solid phases of the Zintl compounds CsPb and NaSn is characterized by fast orientational motions of the polyanions and coupled motions of the cations. Melting is characterized by slow translational motions of the centres of mass of the polyanions. The dynamic behaviour of the ions is associated with dramatic increases in electrical conductivity characteristic of the behaviour expected of a mixed conductor. RP Price, DL (reprint author), ARGONNE NATL LAB,DIV MAT SCI,ARGONNE,IL 60439, USA. RI Price, David Long/A-8468-2013; Saboungi, Marie-Louise/C-5920-2013 OI Saboungi, Marie-Louise/0000-0002-0607-4815 NR 13 TC 2 Z9 2 U1 0 U2 0 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL, ENGLAND BS1 6BE SN 0953-8984 J9 J PHYS-CONDENS MAT JI J. Phys.-Condes. Matter PD MAR 31 PY 1997 VL 9 IS 13 BP 2707 EP 2715 DI 10.1088/0953-8984/9/13/008 PG 9 WC Physics, Condensed Matter SC Physics GA WT338 UT WOS:A1997WT33800008 ER PT J AU Rangaswamy, P Bourke, MAM Wright, PK Jayaraman, N Kartzmark, E Roberts, JA AF Rangaswamy, P Bourke, MAM Wright, PK Jayaraman, N Kartzmark, E Roberts, JA TI The influence of thermal-mechanical processing on residual stresses in titanium matrix composites SO MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING LA English DT Article DE titanium matrix composites; residual stress; thermal-mechanical processing ID STRAINS AB The effects of three distinct thermo-mechanical processes on the residual stress state in a uni-directionally reinforced SCS-6/Ti-6-2-4-2 [0](6) titanium-alloy matrix composite were predicted using a finite element model. For comparison the residual stresses were measured using X-ray and neutron diffraction. Reductions in stress were predicted by the models and both experimental techniques recorded a reduction compared to the as-fabricated material. While the numerically predicted trends qualitatively agreed with the neutron measurements quantitative agreement was not achieved. In the longitudinal direction the neutron results showed closer agreement to the calculation whereas in the transverse direction the X-ray results did. Nevertheless the changes did correlate with improvement in fatigue lifetimes. (C) 1997 Elsevier Science S.A. C1 GE CO,AIRCRAFT ENGINES,CINCINNATI,OH 45215. UNIV CINCINNATI,DEPT MAT SCI & ENGN,CINCINNATI,OH 45221. RP Rangaswamy, P (reprint author), LOS ALAMOS NATL LAB,POB 1663,LOS ALAMOS,NM 87545, USA. NR 20 TC 22 Z9 22 U1 1 U2 8 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0921-5093 J9 MAT SCI ENG A-STRUCT JI Mater. Sci. Eng. A-Struct. Mater. Prop. Microstruct. Process. PD MAR 31 PY 1997 VL 224 IS 1-2 BP 200 EP 209 DI 10.1016/S0921-5093(96)10517-7 PG 10 WC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Science & Technology - Other Topics; Materials Science; Metallurgy & Metallurgical Engineering GA XB337 UT WOS:A1997XB33700024 ER PT J AU Bern, Z Dixon, L Kosower, DA Weinzierl, S AF Bern, Z Dixon, L Kosower, DA Weinzierl, S TI One-loop amplitudes for e(+)e(-)->(q)over-bar q(Q)over-bar-Q SO NUCLEAR PHYSICS B LA English DT Article DE jets; next-to-leading-order; QCD ID JET CROSS-SECTIONS; GAUGE-THEORIES; E+E-ANNIHILATION; HELICITY AMPLITUDES; ALPHA-S; DIMENSIONAL REGULARIZATION; MULTIPLE BREMSSTRAHLUNG; COLLINEAR LIMITS; LIGHT GLUINOS; QCD AB We present the one-loop helicity amplitudes for processes involving a vector boson V (V = W, Z, or gamma*) and four massless quarks, 0 --> V(q) over barq$<(Q)over bar Q>, where V couples to a massless lepton pair. These amplitudes are required for next-to-leading order O(alpha(s)(3)) numerical programs for four-jet production at e(+)e(-) colliders, for W, Z or Drell-Yan production in association with two jets at hadron colliders, and for three-jet production in deeply inelastic scattering experiments, We obtained the amplitudes presented here by using their analytic properties to constrain their form. (C) 1997 Elsevier Science B.V. C1 STANFORD UNIV, STANFORD LINEAR ACCELERATOR CTR, STANFORD, CA 94309 USA. CEA, SERV PHYS THEOR, F-91191 GIF SUR YVETTE, FRANCE. RP UNIV CALIF LOS ANGELES, DEPT PHYS & ASTRON, LOS ANGELES, CA 90095 USA. NR 80 TC 108 Z9 108 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0550-3213 EI 1873-1562 J9 NUCL PHYS B JI Nucl. Phys. B PD MAR 31 PY 1997 VL 489 IS 1-2 BP 3 EP 23 DI 10.1016/S0550-3213(96)00703-1 PG 21 WC Physics, Particles & Fields SC Physics GA WP446 UT WOS:A1997WP44600001 ER PT J AU Gordon, LE Storrow, JK AF Gordon, LE Storrow, JK TI New parton distribution functions for the photon SO NUCLEAR PHYSICS B LA English DT Article ID STRUCTURE-FUNCTION F2; STRUCTURE-FUNCTION F-2(GAMMA); HARD SCATTERING PROCESSES; LARGE-TRANSVERSE-MOMENTUM; INCLUSIVE CROSS-SECTION; GAMMA-GAMMA-COLLISIONS; ORDER QCD CORRECTIONS; JET PRODUCTION; PARTICLE-PRODUCTION; DRELL-YAN AB We present new improved parton distributions for the photon, We fit all available data on the photon structure function, F-2(gamma)(x, Q(2)), with Q(2) greater than or equal to 3 GeV2, in order to determine the quark distributions, We also pay particular attention to the gluon distribution in the photon, g(gamma)(x, Q(2)), which has been poorly constrained in earlier analyses which only include structure function data. We use large p(T) jet production in gamma gamma collisions from TRISTAN to constrain g(gamma). We also see what information can be gleaned from gamma p collisions at HERA on g(gamma) and on the quark distributions at large x, where there are no structure function data. We review future prospects of elucidating the parton distributions of the photon. (C) 1997 Published by Elsevier Science B.V. C1 UNIV MANCHESTER, DEPT THEORET PHYS, MANCHESTER M13 9PL, LANCS, ENGLAND. RP ARGONNE NATL LAB, DIV HIGH ENERGY PHYS, ARGONNE, IL 60439 USA. NR 88 TC 51 Z9 51 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0550-3213 EI 1873-1562 J9 NUCL PHYS B JI Nucl. Phys. B PD MAR 31 PY 1997 VL 489 IS 1-2 BP 405 EP 423 DI 10.1016/S0550-3213(97)00048-5 PG 19 WC Physics, Particles & Fields SC Physics GA WP446 UT WOS:A1997WP44600018 ER PT J AU Laguna, P Zurek, WH AF Laguna, P Zurek, WH TI Density of kinks after a quench: When symmetry breaks, how big are the pieces? SO PHYSICAL REVIEW LETTERS LA English DT Article ID LIQUID-CRYSTALS; COSMIC STRINGS AB Numerical study of order parameter evolution in the course of symmetry breaking transitions with Landau-Ginzburg-like dynamics shows that the density of topological defects, kinks which form during the quench, is proportional to the fourth root of its rate. This is a limited (1D) test of the more general theory of domain-size evolution in the course of symmetry breaking transformations proposed by one of us. Using these ideas, it is possible to compute the density of topological defects from the quench time scale and from the equilibrium scaling of the correlation length and relaxation time near the critical point. C1 PENN STATE UNIV,DEPT ASTRON & ASTROPHYS,UNIVERSITY PK,PA 16802. PENN STATE UNIV,CGPG,UNIVERSITY PK,PA 16802. RP Laguna, P (reprint author), LOS ALAMOS NATL LAB,MS-B288,LOS ALAMOS,NM 87545, USA. NR 20 TC 131 Z9 131 U1 0 U2 1 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD MAR 31 PY 1997 VL 78 IS 13 BP 2519 EP 2522 DI 10.1103/PhysRevLett.78.2519 PG 4 WC Physics, Multidisciplinary SC Physics GA WQ502 UT WOS:A1997WQ50200005 ER PT J AU Chance, J Albergo, S Bieser, F Brady, FP Caccia, Z Cebra, D Chacon, AD Choi, Y Costa, S Elliott, JB Gilkes, M Hauger, JA Hirsch, AS Hjort, EL Insolia, A Justice, M Keane, D Kintner, JC Lisa, MA Matis, HS McMahan, M McParland, C Olson, DL Partlan, MD Porile, NT Potenza, R Rai, G Rasmussen, J Ritter, HG Romanski, J Romero, JL Russo, GV Scharenberg, R Scott, A Shao, Y Srivastava, B Symons, TJM Tincknell, M Tuve, C Wang, S Warren, P Wieman, HH Wienold, T Wolf, K AF Chance, J Albergo, S Bieser, F Brady, FP Caccia, Z Cebra, D Chacon, AD Choi, Y Costa, S Elliott, JB Gilkes, M Hauger, JA Hirsch, AS Hjort, EL Insolia, A Justice, M Keane, D Kintner, JC Lisa, MA Matis, HS McMahan, M McParland, C Olson, DL Partlan, MD Porile, NT Potenza, R Rai, G Rasmussen, J Ritter, HG Romanski, J Romero, JL Russo, GV Scharenberg, R Scott, A Shao, Y Srivastava, B Symons, TJM Tincknell, M Tuve, C Wang, S Warren, P Wieman, HH Wienold, T Wolf, K TI The energy dependence of flow in Ni induced collisions from 400A to 1970A MeV SO PHYSICAL REVIEW LETTERS LA English DT Article ID HEAVY-ION COLLISIONS; RELATIVISTIC NUCLEAR COLLISIONS; TRANSVERSE-MOMENTUM ANALYSIS; COLLECTIVE MOTION; FRAGMENT FLOW; BEAM ENERGIES; AR+PB; AR+KCL AB We study the energy dependence of collective (hydrodynamic-like) nuclear matter flow in (400-1970)A MeV Ni + Au and (1000-1970)A MeV Ni + Cu reactions. The flow increases with energy, appears to reach a maximum, and then to decrease at higher energies. A way of comparing the energy dependence of flow values for different projectile-target mass combinations is introduced, which demonstrates a more-or-less common scaling behavior among flow values from different systems. C1 UNIV CATANIA,I-95129 CATANIA,ITALY. IST NAZL FIS NUCL,I-95129 CATANIA,ITALY. KENT STATE UNIV,KENT,OH 44242. UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV NUCL SCI,BERKELEY,CA 94720. PURDUE UNIV,W LAFAYETTE,IN 47907. TEXAS A&M UNIV,COLLEGE STN,TX 77843. RP Chance, J (reprint author), UNIV CALIF DAVIS,DAVIS,CA 95616, USA. RI Insolia, Antonio/M-3447-2015; TUVE', Cristina/P-3933-2015 OI Insolia, Antonio/0000-0002-9040-1566; TUVE', Cristina/0000-0003-0739-3153 NR 25 TC 30 Z9 30 U1 0 U2 1 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD MAR 31 PY 1997 VL 78 IS 13 BP 2535 EP 2538 DI 10.1103/PhysRevLett.78.2535 PG 4 WC Physics, Multidisciplinary SC Physics GA WQ502 UT WOS:A1997WQ50200009 ER PT J AU Ding, H Norman, MR Yokoya, T Takeuchi, T Randeria, M Campuzano, JC Takahashi, T Mochiku, T Kadowaki, K AF Ding, H Norman, MR Yokoya, T Takeuchi, T Randeria, M Campuzano, JC Takahashi, T Mochiku, T Kadowaki, K TI Evolution of the Fermi surface with carrier concentration in Bi2Sr2CaCu2O8+delta SO PHYSICAL REVIEW LETTERS LA English DT Article ID ANGLE-RESOLVED PHOTOEMISSION; COHERENCE LENGTH SUPERCONDUCTORS; ELECTRONIC-STRUCTURE; NORMAL-STATE; GAP; YBA2CU3OX AB We show, by use of angle-resolved photoemission spectroscopy, that underdoped Bi2Sr2CaCu2O8+delta appears to have a large Fermi surface centered at (pi, pi), even for samples with a T-c as low as 15 K. No clear evidence of a Fermi surface pocket around (pi/2, pi/2) has been found. These conclusions are based on a determination of the minimum gap locus in the pseudogap regime T-c < T < T*, which is found to coincide with the locus of gapless excitations in momentum space (Fermi surface) determined above T*. These results suggest that the pseudogap is more likely of precursor pairing rather than magnetic origin. C1 ARGONNE NATL LAB,DIV MAT SCI,ARGONNE,IL 60439. TOHOKU UNIV,DEPT PHYS,SENDAI,MIYAGI 980,JAPAN. NAGOYA UNIV,DEPT CRYSTALLINE MAT SCI,NAGOYA,AICHI 46401,JAPAN. TATA INST FUNDAMENTAL RES,BOMBAY 400005,MAHARASHTRA,INDIA. NATL RES INST MET,TSUKUBA,IBARAKI 305,JAPAN. UNIV TSUKUBA,INST MAT SCI,TSUKUBA,IBARAKI 305,JAPAN. RP Ding, H (reprint author), UNIV ILLINOIS,DEPT PHYS,CHICAGO,IL 60607, USA. RI Takahashi, Takashi/E-5080-2010; Tohoku, Arpes/A-4890-2010; Campuzano, Juan Carlos/G-4358-2012; Norman, Michael/C-3644-2013; YOKOYA, Takayoshi/B-1478-2011; OI Ding, Hong/0000-0003-4422-9248 NR 19 TC 229 Z9 231 U1 2 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 MAR 31 PY 1997 VL 78 IS 13 BP 2628 EP 2631 DI 10.1103/PhysRevLett.78.2628 PG 4 WC Physics, Multidisciplinary SC Physics GA WQ502 UT WOS:A1997WQ50200033 ER PT J AU Rimberg, AJ Ho, TR Kurdak, C Clarke, J Campman, KL Gossard, AC AF Rimberg, AJ Ho, TR Kurdak, C Clarke, J Campman, KL Gossard, AC TI Dissipation-driven superconductor-insulator transition in a two-dimensional Josephson-junction array SO PHYSICAL REVIEW LETTERS LA English DT Article ID DISORDERED 2-DIMENSIONAL SUPERCONDUCTORS; GLOBAL PHASE COHERENCE; GRANULAR METAL-FILMS; QUANTUM FLUCTUATIONS; ONSET AB We have fabricated a two-dimensional array of Josephson junctions within 100 nm of a two-dimensional electron gas (2DEG) in a GaAs/AlGaAs heterostructure. The screening provided by the 2DEG causes the array to show superconducting behavior despite a large junction resistance. Varying the resistance per square of the 2DEG changes the dissipation in the electrodynamic environment of the array independently of any other parameters in the system. As the resistance increases, the current-voltage characteristics of the array change from superconducting to insulating in character. C1 UNIV CALIF BERKELEY,DEPT PHYS,BERKELEY,CA 94720. UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV SCI MAT,BERKELEY,CA 94720. UNIV CALIF SANTA BARBARA,DEPT MAT,SANTA BARBARA,CA 93106. RP Rimberg, AJ (reprint author), RICE UNIV,DEPT PHYS,HOUSTON,TX 77251, USA. RI Rimberg, Alexander/B-8076-2010 NR 27 TC 79 Z9 79 U1 0 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 MAR 31 PY 1997 VL 78 IS 13 BP 2632 EP 2635 DI 10.1103/PhysRevLett.78.2632 PG 4 WC Physics, Multidisciplinary SC Physics GA WQ502 UT WOS:A1997WQ50200034 ER PT J AU Dominguez, D GronbechJensen, N Bishop, AR AF Dominguez, D GronbechJensen, N Bishop, AR TI First-order melting of a moving vortex lattice: Effects of disorder SO PHYSICAL REVIEW LETTERS LA English DT Article ID HIGH-TEMPERATURE SUPERCONDUCTORS; FLUX-LATTICE; SINGLE-CRYSTALS; MONTE-CARLO; TRANSITION; YBA2CU3O7-DELTA; LINE; LIQUID; STATE AB We study the melting of a moving vortex lattice through numerical simulations with the current-driven 3D XY model with disorder. We find that there is a first-order phase transition even for large disorder when the corresponding equilibrium transition is continuous. The low temperature phase is an anisotropic moving glass. C1 LOS ALAMOS NATL LAB,DIV THEORET,LOS ALAMOS,NM 87545. LOS ALAMOS NATL LAB,CTR NONLINEAR STUDIES,LOS ALAMOS,NM 87545. RP Dominguez, D (reprint author), CTR ATOM BARILOCHE,RA-8400 SAN CARLOS BARILO,RIO NEGRO,ARGENTINA. RI Dominguez, Daniel/E-9304-2016 OI Dominguez, Daniel/0000-0002-6204-0150 NR 35 TC 44 Z9 44 U1 0 U2 1 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD MAR 31 PY 1997 VL 78 IS 13 BP 2644 EP 2647 DI 10.1103/PhysRevLett.78.2644 PG 4 WC Physics, Multidisciplinary SC Physics GA WQ502 UT WOS:A1997WQ50200037 ER PT J AU Daido, H Ninomiya, S Imani, T Okaichi, Y Takagi, M Kodama, R Takabe, H Kato, Y Koike, F Nilsen, J Murai, K AF Daido, H Ninomiya, S Imani, T Okaichi, Y Takagi, M Kodama, R Takabe, H Kato, Y Koike, F Nilsen, J Murai, K TI Atomic number scaling of the nickel-like soft X-ray lasers SO INTERNATIONAL JOURNAL OF MODERN PHYSICS B LA English DT Review ID NEON-LIKE SELENIUM; HIGH-GAIN; PREPULSE TECHNIQUE; SHORT WAVELENGTH; XUV LASER; IONS; NM; AMPLIFICATION; PLASMAS; TARGET AB We report the review of the experimental results obtained at the Institute of Laser Engineering, Osaka University, of the sofi; X-ray lasing in various Ni-like ions whose atomic numbers range from 47(Ag) to 66(Dy). The lasing wavelengths are between 14 nm and 5 nm. X-ray lasing in these materials were obtained when the plasma profiles were properly controlled in time and space by irradiation of curved slab targets with multiple laser pulses. We also describe the original work of the atomic physics calculations which provide the transition energies, transition probabilities and other atomic constants for Ni-like ion species whose atomic numbers range from 36 to 92 calculated with GRASP code (multi-configuration Dirac Fock code) and YODA code (relativistic distorted wave code). Based on these atomic constants, we have calculated the kinetics of the population inversion with a simplified rate equation model in conjunction with a one-dimensional hydrodynamic code to find out the desired pumping conditions. We show a possibility for significant improvement in the pumping efficiency with the use of a picosecond laser irradiating a properly configured preformed plasma. Finally, a simplified estimation of the pumping efficiency is described based on the atomic constants and plasma physics issues. C1 KITASATO UNIV,SCH MED,PHYS LAB,SAGAMIHARA,KANAGAWA 228,JAPAN. LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94551. OSAKA NATL RES INST,IKEDA,OSAKA 563,JAPAN. RP Daido, H (reprint author), OSAKA UNIV,INST LASER ENGN,2-6 YAMADA OKA,SUITA,OSAKA 565,JAPAN. RI Kodama, Ryosuke/G-2627-2016 NR 62 TC 53 Z9 53 U1 0 U2 8 PU WORLD SCIENTIFIC PUBL CO PTE LTD PI SINGAPORE PA JOURNAL DEPT PO BOX 128 FARRER ROAD, SINGAPORE 9128, SINGAPORE SN 0217-9792 J9 INT J MOD PHYS B JI Int. J. Mod. Phys. B PD MAR 30 PY 1997 VL 11 IS 8 BP 945 EP 990 DI 10.1142/S0217979297000496 PG 46 WC Physics, Applied; Physics, Condensed Matter; Physics, Mathematical SC Physics GA WR058 UT WOS:A1997WR05800001 ER PT J AU Zhong, CJ Porter, MD AF Zhong, CJ Porter, MD TI Fine structure in the voltammetric desorption curves of alkanethiolate monolayers chemisorbed at gold SO JOURNAL OF ELECTROANALYTICAL CHEMISTRY LA English DT Article DE alkanethiolate; gold; desorption; chemisorption; fine structure; voltammetry ID SELF-ASSEMBLED MONOLAYERS; SULFUR BOND-CLEAVAGE; UNDERPOTENTIAL DEPOSITION; ELECTRODE SURFACE; METAL-SURFACES; BINDING-SITES; ALKYL THIOLS; AU(111); AU; AG AB This paper presents the preliminary results from a study of the chain length dependence of the reductive desorption and oxidative re-deposition processes of alkanethiolate monolayers on Au(111) electrodes. In contrast to the more extensively studied short chain length monolayers, we report a previously undetected fine structure in the voltammetric waves for monolayers composed of alkyl chains of more than 10 carbons. The short chain systems in general exhibit a single voltammetric wave for the desorption and re-deposition processes. In contrast, multiple voltammetric waves separated by 20 to 100 mV are found for both the desorption and the re-deposition of the long chain systems. The origin of these results is examined in terms of possible differences in the adlayer domain structures and in the binding modes between sulfur and gold. C1 IOWA STATE UNIV SCI & TECHNOL,AMES LAB,US DOE,MICROANALYT INSTRUMENTAT CTR,AMES,IA 50011. IOWA STATE UNIV SCI & TECHNOL,DEPT CHEM,AMES,IA 50011. RI Zhong, Chuan-Jian/D-3394-2013 NR 37 TC 136 Z9 136 U1 0 U2 10 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0022-0728 J9 J ELECTROANAL CHEM JI J. Electroanal. Chem. PD MAR 30 PY 1997 VL 425 IS 1-2 BP 147 EP 153 DI 10.1016/S0022-0728(96)04957-1 PG 7 WC Chemistry, Analytical; Electrochemistry SC Chemistry; Electrochemistry GA XE506 UT WOS:A1997XE50600017 ER PT J AU Wang, J Park, DS Pamidi, PVA White, C Renschler, CL AF Wang, J Park, DS Pamidi, PVA White, C Renschler, CL TI Microelectrode ensembles based on overlaying ultrathin porous polyacrylonitrile on dense carbon films SO JOURNAL OF ELECTROANALYTICAL CHEMISTRY LA English DT Article DE recessed microelectrodes; polyacrylonitrile; partially blocked surfaces; composite electrodes ID COMPOSITE ELECTRODES; CHRONOAMPEROMETRIC RESPONSE; ELECTROANALYSIS AB A new procedure for preparing microelectrode ensembles, based on casting an ultrathin microcellular polyacrylonitrile (PAN) insulating foam onto a dense carbonized PAN film, is described. The resulting partially blocked surfaces display the behavioral characteristics of ensembles of recessed microelectrodes (of small depth), with steady-state currents at moderate and long timescales. Cyclic voltammetry and chronoamperometry were used to elucidate the electrochemical behavior, while scanning electron microscopy sheds useful light on the surface microstructure. Square-wave stripping voltammetry is demonstrated for the quantification of nanomolar concentrations of lead using short deposition periods and unstirred solutions. These and other PAN-derived composite electrodes present new opportunities for various electrochemical and analytical applications. C1 SANDIA NATL LABS,DEPT 1812,ALBUQUERQUE,NM 87185. RP Wang, J (reprint author), NEW MEXICO STATE UNIV,DEPT CHEM & BIOCHEM,LAS CRUCES,NM 88003, USA. RI Wang, Joseph/C-6175-2011 NR 13 TC 3 Z9 3 U1 2 U2 4 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0022-0728 J9 J ELECTROANAL CHEM JI J. Electroanal. Chem. PD MAR 30 PY 1997 VL 425 IS 1-2 BP 179 EP 182 DI 10.1016/S0022-0728(96)04948-0 PG 4 WC Chemistry, Analytical; Electrochemistry SC Chemistry; Electrochemistry GA XE506 UT WOS:A1997XE50600022 ER PT J AU Wilson, WD Schaldach, CM Bourcier, WL AF Wilson, WD Schaldach, CM Bourcier, WL TI Single- and double-layer coupling of Schrodinger and Poisson-Boltzmann equations SO CHEMICAL PHYSICS LETTERS LA English DT Article ID SOLVENT; CONTINUUM; ELECTROSTATICS; DISTRIBUTIONS; MECHANICS; SOLUTE; FIELD AB We present a method for incorporating solvent effects, including ionic strength, into ab initio electronic structure determinations and apply the method to the calculation of the free energy of solvation of the carbonate ion, CO32-. The Green's function-based method couples the Schrodinger and linearized Poisson-Boltzmann equations through both the single and double layer surface charge distributions induced at a molecular-solvent interface. Single and double layers of charge are obtained from solution of the Poisson-Boltzmann equation (and added iteratively to the Hamiltonian) using electronic structure results (MP2/6-31G**) directly, eliminating the uncertainty in employing fractional charges. C1 UNIV CALIF BERKELEY, BERKELEY, CA 94720 USA. LAWRENCE LIVERMORE NATL LAB, LIVERMORE, CA 94550 USA. RP SANDIA NATL LABS, LIVERMORE, CA 94566 USA. NR 25 TC 12 Z9 12 U1 0 U2 4 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0009-2614 EI 1873-4448 J9 CHEM PHYS LETT JI Chem. Phys. Lett. PD MAR 28 PY 1997 VL 267 IS 5-6 BP 431 EP 437 DI 10.1016/S0009-2614(97)00135-8 PG 7 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA WQ108 UT WOS:A1997WQ10800006 ER PT J AU Koretsky, GM Knickelbein, MB AF Koretsky, GM Knickelbein, MB TI Infrared photodissociation spectroscopy of Ag-n(C6H6)(m) and Ag-n(C6D6)(m) clusters: Evidence of adsorption-induced symmetry reduction in benzene SO CHEMICAL PHYSICS LETTERS LA English DT Article ID SURFACE SELECTION RULE; ELECTRON-ENERGY LOSS; RAMAN-SPECTROSCOPY; IONIZATION-POTENTIALS; SILVER; COMPLEXES; AMMONIA; SPECTRA AB The infrared photodissociation spectra of Ag-n(C6H6)(m) and Ag-n(C6D6)(m) have been recorded near 10 mu m for n = 3-7. For Ag-n(C6H6)(m), we observe a feature around 1032 cm(-1), which is assigned to the allowed e(lu) fundamental of benzene. In addition, features are observed near 986 cm(-1) in Ag-n(C6H6)(m) and 938 cm(-1) in Ag-n(C6D6)(m). These bands are assigned to the a(lg) C-C breathing mode - a transition which, while forbidden for gas-phase benzene, is dipole allowed for benzene whose symmetry is reduced (to C-6v Or lower) by adsorption. RP Koretsky, GM (reprint author), ARGONNE NATL LAB,DIV CHEM,9700 S CASS AVE,ARGONNE,IL 60439, USA. NR 29 TC 20 Z9 20 U1 1 U2 4 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0009-2614 J9 CHEM PHYS LETT JI Chem. Phys. Lett. PD MAR 28 PY 1997 VL 267 IS 5-6 BP 485 EP 490 DI 10.1016/S0009-2614(97)00132-2 PG 6 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA WQ108 UT WOS:A1997WQ10800014 ER PT J AU Cowan, RD Fischer, CF Hansen, JE Kempter, V AF Cowan, RD Fischer, CF Hansen, JE Kempter, V TI Excited states of the negative nitrogen ion: Energies and lifetimes SO JOURNAL OF PHYSICS B-ATOMIC MOLECULAR AND OPTICAL PHYSICS LA English DT Article ID ELECTRON; COLLISIONS; SURFACE; SCATTERING; EMISSION; C-(S-4); ATOMS; WIDTH AB The present state of knowledge about the excited states of the negative nitrogen ion is reviewed, and calculations of energies and lifetimes of the states belonging to the 2p(4) configuration are reported. Systematic MCHF procedures are applied to the study of the electron affinities of the 2p(4) ID and IS states of N- relative to the 2p(3) D-2 neutral nitrogen parent state. Assuming a 1s(2) {2s, 2p}(3) core for both the atom and the negative ion, a non-relaiivisticelectron affinity of 0.871(2) eV is predicted for the 2D term which implies that the D-1 term in N- is located 1.513 eV above the ground state of nitrogen. Similarly, the S-1 term is predicted to be 1.390(1) eV above the D-1 term: The two terms can decay only via magnetic interactions. and Cl calculations give lifetimes equal to 1 x 10(-10) and 7 x 10(-11) s for the D-1 and S-1 terms, respectively. We estimate the lifetimes to be accurate within a factor of five. The importance of the results, in particular of the lifetime values, for C-14 dating is pointed out. C1 VANDERBILT UNIV,NASHVILLE,TN 37235. UNIV AMSTERDAM,VAN DER WAALS ZEEMAN INST,NL-1018 XE AMSTERDAM,NETHERLANDS. TECH UNIV CLAUSTHAL,INST PHYS,D-38678 CLAUSTHAL ZELLERF,GERMANY. RP Cowan, RD (reprint author), LOS ALAMOS NATL LAB,POB 1663,LOS ALAMOS,NM 87545, USA. NR 29 TC 16 Z9 16 U1 0 U2 4 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL, ENGLAND BS1 6BE SN 0953-4075 J9 J PHYS B-AT MOL OPT JI J. Phys. B-At. Mol. Opt. Phys. PD MAR 28 PY 1997 VL 30 IS 6 BP 1457 EP 1466 DI 10.1088/0953-4075/30/6/014 PG 10 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA WT341 UT WOS:A1997WT34100014 ER PT J AU McGuire, EJ AF McGuire, EJ TI Systematics of ns subshell electron ionization cross sections SO JOURNAL OF PHYSICS B-ATOMIC MOLECULAR AND OPTICAL PHYSICS LA English DT Article ID ENERGY-RESOLVED ELECTRONS; IMPACT-IONIZATION; BORN-APPROXIMATION; EXCITATION-AUTOIONIZATION; IONS; SODIUM; ATOMS; RATES; NA; CL-5+ AB The excellent agreement between recent converged close-coupling calculations of electron ionization cross sections of atoms and ions and plane-wave Born approximation (PWBA) calculations leads to the hypothesis that PWBA calculations are accurate to 10% at high energy, and therefore can be used to renormalize experimental data to produce cross sections of 10% accuracy near threshold. Comparisons are made of various calculations of 2s and 3s electron ionization cross sections in low-Z atoms and ions, of PWBA calculations and experiments for atoms and ions up to Ba1+, and of scaled peak cross sections to interrelate experiments and calculations on isoelectronic sequences. RP McGuire, EJ (reprint author), SANDIA NATL LABS,DIV 1271,POB 5800,ALBUQUERQUE,NM 87185, USA. NR 54 TC 9 Z9 9 U1 0 U2 2 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL, ENGLAND BS1 6BE SN 0953-4075 J9 J PHYS B-AT MOL OPT JI J. Phys. B-At. Mol. Opt. Phys. PD MAR 28 PY 1997 VL 30 IS 6 BP 1563 EP 1587 DI 10.1088/0953-4075/30/6/022 PG 25 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA WT341 UT WOS:A1997WT34100022 ER PT J AU Wu, W Havener, CC AF Wu, W Havener, CC TI State-selective electron capture by Si4+ from D in a merged-beams apparatus SO JOURNAL OF PHYSICS B-ATOMIC MOLECULAR AND OPTICAL PHYSICS LA English DT Letter ID CHARGE-TRANSFER; COLLISIONS; IONS; HYDROGEN AB We demonstrate the feasibility of rising a multi-grid energy analyser in a merged-beams apparatus for studies of state-selective electron capture at near-thermal collision energies. In collisions of Si4+ with D from 4-100 eV u(-1), electron capture to Si3+(3d). and Si3+(4s) are identified. The corresponding partial cross sections have been determined and compared with theoretical predictions. C1 OAK RIDGE NATL LAB, OAK RIDGE, TN 37831 USA. NR 21 TC 4 Z9 4 U1 0 U2 0 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0953-4075 J9 J PHYS B-AT MOL OPT JI J. Phys. B-At. Mol. Opt. Phys. PD MAR 28 PY 1997 VL 30 IS 6 BP L213 EP L220 DI 10.1088/0953-4075/30/6/005 PG 8 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA WT341 UT WOS:A1997WT34100005 ER PT J AU Bockrath, M Cobden, DH McEuen, PL Chopra, NG Zettl, A Thess, A Smalley, RE AF Bockrath, M Cobden, DH McEuen, PL Chopra, NG Zettl, A Thess, A Smalley, RE TI Single-electron transport in ropes of carbon nanotubes SO SCIENCE LA English DT Article ID MICROTUBULES AB The electrical properties of individual bundles, or ''ropes,'' of single-walled carbon nanotubes have been measured. Below about 10 kelvin, the low-bias conductance was suppressed for voltages less than a few millivolts. In addition, dramatic peaks were observed in the conductance as a function of a gate voltage that modulated the number of electrons in the rope. These results are interpreted in terms of single-electron charging and resonant tunneling through the quantized energy levels of the nanotubes composing the rope. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,INST MOL DESIGN,BERKELEY,CA 94720. UNIV CALIF BERKELEY,DEPT PHYS,BERKELEY,CA 94720. RICE UNIV,RICE QUANTUM INST,CTR NANOSCALE SCI & TECHNOL,HOUSTON,TX 77251. RICE UNIV,DEPT CHEM,HOUSTON,TX 77251. RICE UNIV,DEPT PHYS,HOUSTON,TX 77251. RI Zettl, Alex/O-4925-2016 OI Zettl, Alex/0000-0001-6330-136X NR 21 TC 1106 Z9 1123 U1 8 U2 98 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 SN 0036-8075 J9 SCIENCE JI Science PD MAR 28 PY 1997 VL 275 IS 5308 BP 1922 EP 1925 DI 10.1126/science.275.5308.1922 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA WQ513 UT WOS:A1997WQ51300042 ER PT J AU Otarod, M Happel, J Soong, Y Walter, E Pronzato, L AF Otarod, M Happel, J Soong, Y Walter, E Pronzato, L TI Transient isotopic tracing of nickel catalyst deactivation in a plug-flow reactor SO APPLIED CATALYSIS A-GENERAL LA English DT Article DE methanation; nickel; plug-flow reactor AB Deactivation of Raney nickel is studied using the methanation rate data in a plug-flow reactor. It is shown that a model consisting of a constant and a monoexponential term describes the deactivation rate data very well suggesting that the catalytic activity of nickel is controlled by two components. One component seems to show a steady catalytic activity where the activity of the other component appears to decline exponentially. Transient tracing of the methanation on Raney nickel using (CO)-C-13 indicates that these correspond to two forms of intermediates adsorbed on two distinct catalyst sites. These findings are supported by rigorous statistical analyses of the correlation between model parameters and the goodness of the fit of data to the model. C1 COLUMBIA UNIV,DEPT CHEM ENGN MAT SCI & MIN,NEW YORK,NY 10027. UNIV SCRANTON,DEPT MATH,SCRANTON,PA 18510. US DOE,PITTSBURGH ENERGY TECHNOL CTR,PITTSBURGH,PA 15236. ECOLE SUPER ELECT,CNRS,SIGNAUX & SYST LAB,F-91192 GIF SUR YVETTE,FRANCE. CNRS,URA 1376,LAB INFORMAT SIGNAUX & SYST,F-06560 VALBONNE,FRANCE. NR 14 TC 2 Z9 2 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0926-860X J9 APPL CATAL A-GEN JI Appl. Catal. A-Gen. PD MAR 27 PY 1997 VL 151 IS 1 BP 97 EP 107 DI 10.1016/S0926-860X(96)00291-8 PG 11 WC Chemistry, Physical; Environmental Sciences SC Chemistry; Environmental Sciences & Ecology GA WQ177 UT WOS:A1997WQ17700005 ER PT J AU Lin, CH Yang, RQ Zhang, D Murry, SJ Pei, SS Allerman, AA Kutz, SR AF Lin, CH Yang, RQ Zhang, D Murry, SJ Pei, SS Allerman, AA Kutz, SR TI Type-II interband quantum cascade laser at 3.8 mu m SO ELECTRONICS LETTERS LA English DT Article DE semiconductor junction lasers; semiconductor quantum wells AB The authors have demonstrated the first stimulated emission From Sb-based type-II quantum cascade configuration. Laser emission al 3.8 mu m has been observed for temperatures up to 170K. The device was composed of 20 periods of active regions separated by digitally graded quantum-well injection regions. C1 SANDIA NATL LABS,ALBUQUERQUE,NM 87123. RP Lin, CH (reprint author), UNIV HOUSTON,CTR SPACE VACUUM EPITAXY,HOUSTON,TX 77204, USA. NR 12 TC 97 Z9 99 U1 0 U2 11 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 MAR 27 PY 1997 VL 33 IS 7 BP 598 EP 599 DI 10.1049/el:19970421 PG 2 WC Engineering, Electrical & Electronic SC Engineering GA WU001 UT WOS:A1997WU00100039 ER PT J AU McCullough, EA Apra, E Nichols, J AF McCullough, EA Apra, E Nichols, J TI Comparison of the Becke-Lee-Yang-Parr and Becke-Perdew-Wang exchange-correlation functionals for geometrics of cyclopentadienyl transition metal complexes SO JOURNAL OF PHYSICAL CHEMISTRY A LA English DT Article ID GAUSSIAN-BASIS SETS; CORRELATION-ENERGY; MOLECULAR CALCULATIONS; ELECTRON-GAS; DENSITY; ATOMS; APPROXIMATION; PERFORMANCE; ACCURATE; HYDROGEN AB Complete all-electron density functional geometry optimizations have been performed on six ''half-sandwich'' cyclopentadienyl-transition metal complexes using both the Becke-Lee-Yang-Parr (BLYP) and Becke-Perdew-Wang functionals (BPW91). The two functionals agree very well with each other for bond distances not involving the metal. In a double-zeta plus polarization quality basis, both overestimate these distances by amounts similar to those observed in small molecules with equivalent basis sets. For the single first series complex examined, BPW91 gives comparable agreement for all the bonds, but for complexes of the second transition series, BPW91 consistently overestimates the metal-Cp C distances by 0.06-0.07 Angstrom. Metal f functions shorten these slightly. After estimated relativistic contractions are applied, the BPW91 metal-Cp C overestimates for the second series complexes would be reduced to levels comparable to the first series or small molecules without metals. However, BLYP consistently gives significantly longer values than BPW91 for all distances involving the metal in both the first and second series complexes, so that even after applying all the previous corrections, overestimates greater than or equal to 0.07 Angstrom relative to experiment would persist for the metal-Cp C bonds. Consistent disagreements of this magnitude between the two functionals for normal chemical bonds appear to be unprecedented in the literature. C1 PACIFIC NW NATL LAB,RICHLAND,WA 99352. RP McCullough, EA (reprint author), UTAH STATE UNIV,DEPT CHEM & BIOCHEM,LOGAN,UT 84322, USA. RI Apra, Edoardo/F-2135-2010 OI Apra, Edoardo/0000-0001-5955-0734 NR 30 TC 15 Z9 15 U1 0 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 1089-5639 J9 J PHYS CHEM A JI J. Phys. Chem. A PD MAR 27 PY 1997 VL 101 IS 13 BP 2502 EP 2508 DI 10.1021/jp963430d PG 7 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA WQ630 UT WOS:A1997WQ63000020 ER PT J AU Greenfield, SR Seibert, M Govindjee Wasielewski, MR AF Greenfield, SR Seibert, M Govindjee Wasielewski, MR TI Direct measurement of the effective rate constant for primary charge separation in isolated photosystem II reaction centers SO JOURNAL OF PHYSICAL CHEMISTRY B LA English DT Letter ID TRANSIENT ABSORPTION-SPECTROSCOPY; DETECTION-WAVELENGTH DEPENDENCE; CHLOROPHYLL-A; PLANT PHOTOSYNTHESIS; TEMPERATURE; RESOLUTION; PHEOPHYTIN; KINETICS; RADICALS; ENERGY AB Transient absorption measurements of the pheophytin a anion band and a band bleach region using preferential excitation of P680 are performed on isolated photosystem II reaction centers to determine the effective rate constant for charge separation. A novel analysis of the Q(x) band bleach region explicitly takes the changing background into account in order to directly measure the rate of growth of the bleach. Both spectral regions reveal biphasic kinetics, with a ca. (8 ps)(-1) rate constant for the faster component, and a ca. (50 ps)(-1) rate constant for the slower component. We propose that the faster component corresponds to the effective rate constant for charge separation from within the equilibrated reaction center core and provides a lower limit for the intrinsic rate constant for charge separation. The slower component corresponds to charge separation that is limited by slow energy transfer from a long-wavelength accessory chlorophyll a. C1 ARGONNE NATL LAB,DIV CHEM,ARGONNE,IL 60439. NATL RENEWABLE ENERGY LAB,BASIC SCI CTR,GOLDEN,CO 80401. UNIV ILLINOIS,DEPT PLANT BIOL,URBANA,IL 61801. NORTHWESTERN UNIV,DEPT CHEM,EVANSTON,IL 60208. NR 32 TC 59 Z9 61 U1 1 U2 3 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 1089-5647 J9 J PHYS CHEM B JI J. Phys. Chem. B PD MAR 27 PY 1997 VL 101 IS 13 BP 2251 EP 2255 DI 10.1021/jp962982t PG 5 WC Chemistry, Physical SC Chemistry GA WQ629 UT WOS:A1997WQ62900001 ER PT J AU Laufer, E Dahn, R Orozco, OE Yeo, CY Pisenti, J Henrique, D Abbott, UK Fallon, JF Tabin, C AF Laufer, E Dahn, R Orozco, OE Yeo, CY Pisenti, J Henrique, D Abbott, UK Fallon, JF Tabin, C TI Expression of radical fringe in limb-bud ectoderm regulates apical ectodermal ridge formation SO NATURE LA English DT Article ID PATTERN-FORMATION; WING DEVELOPMENT; VERTEBRATE LIMB; VENTRAL CELLS; CHICK-EMBRYO; MUTANT; DORSAL; DROSOPHILA; INDUCTION; MOUSE AB The apical ectodermal ridge of the vertebrate limb bud lies at the junction of the dorsal and ventral ectoderm and directs patterning of the growing limb. Its formation is directed by the boundary between cells that do and cells that do not express the gene Radical fringe. This is similar to the establishment of the margin cells at the Drosophila wing dorsoventral border by fringe. Radical fringe expression in chick-limb dorsal ectoderm is established In part through repression by Engrailed-1 in the ventral ectoderm. C1 HARVARD UNIV,SCH MED,DEPT GENET,BOSTON,MA 02115. UNIV WISCONSIN,DEPT ANAT,MADISON,WI 53706. LAWRENCE LIVERMORE NATL LAB,DEPT AVIAN SCI,DAVIS,CA 95616. IMPERIAL CANC RES FUND,DEV GENET LAB,LONDON WC2A 3PX,ENGLAND. RI Henrique, Domingos/E-5460-2010; OI Henrique, Domingos/0000-0001-8869-1894; Yeo, Chang-Yeol/0000-0002-4440-1215 NR 47 TC 216 Z9 220 U1 1 U2 4 PU MACMILLAN MAGAZINES LTD PI LONDON PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW SN 0028-0836 J9 NATURE JI Nature PD MAR 27 PY 1997 VL 386 IS 6623 BP 366 EP 373 DI 10.1038/386366a0 PG 8 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA WQ170 UT WOS:A1997WQ17000056 PM 9121552 ER PT J AU Dillon, AC Jones, KM Bekkedahl, TA Kiang, CH Bethune, DS Heben, MJ AF Dillon, AC Jones, KM Bekkedahl, TA Kiang, CH Bethune, DS Heben, MJ TI Storage of hydrogen in single-walled carbon nanotubes SO NATURE LA English DT Article ID TUBULES AB Pores of molecular dimensions can adsorb large quantities of gases owing to the enhanced density of the adsorbed material inside the pores(1), a consequence of the attractive potential of the pore walls, Pederson and Broughton have suggested(2) that carbon nanotubes, which have diameters of typically a few nanometres, should be able to draw up liquids by capillarity, and this effect has been seen for low-surface-tension liquids in large-diameter, multi-walled nanotubes(3). Here we show that a gas can condense to high density inside narrow, single-walled nanotubes (SWNTs), Temperature-programmed desorption spectrosocopy shows that hydrogen will condense inside SWNTs under conditions that do not induce adsorption within a standard mesoporous activated carbon, The very high hydrogen uptake in these materials suggests that they might be effective as a hydrogen-storage material for fuel-cell electric vehicles. C1 NATL RENEWABLE ENERGY LAB,GOLDEN,CO 80401. IBM CORP,ALMADEN RES CTR,DIV RES,SAN JOSE,CA 95120. RI 李, 莹/C-5680-2012 NR 22 TC 2973 Z9 3122 U1 77 U2 839 PU MACMILLAN MAGAZINES LTD PI LONDON PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW SN 0028-0836 J9 NATURE JI Nature PD MAR 27 PY 1997 VL 386 IS 6623 BP 377 EP 379 DI 10.1038/386377a0 PG 3 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA WQ170 UT WOS:A1997WQ17000058 ER PT J AU Henning, RW LeonEscamilla, EA Zhao, JT Corbett, JD AF Henning, RW LeonEscamilla, EA Zhao, JT Corbett, JD TI Stabilization by hydrogen. Synthetic and structural studies of the Zintl phase Ba5Ga6H2 SO INORGANIC CHEMISTRY LA English DT Article ID CRYSTAL-STRUCTURE; ALKALINE-EARTH; CLUSTERS; GALLIUM; METALS AB Synthesis of the phase formerly reported as Ba5Ga6 succeeds only in the presence of hydrogen. The heavy atom structure of Ba5Ga6H2 has been redetermined by single-crystal X-ray diffraction (trigonal P3cl, Z = 2, a = 7.7698(2) Angstrom, c = 14.3902(7) Angstrom), and the hydrogen positions have been elucidated by time-of-flight neutron powder diffraction, The unit cell contains isolated slightly distorted octahedra Ga-6(8-) with barium cations over all edges. Hydride is bound in two types of barium tetrahedra [d(Ba-H) = 2.61-2.62 Angstrom]. The stoichiometry is appropriate for a Zintl phase: (Ba2+)(5)Ga-6(8-)(H-)2. C1 IOWA STATE UNIV SCI & TECHNOL,DEPT CHEM,AMES,IA 50011. IOWA STATE UNIV SCI & TECHNOL,AMES LAB,US DOE,AMES,IA 50011. NR 24 TC 32 Z9 32 U1 0 U2 5 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0020-1669 J9 INORG CHEM JI Inorg. Chem. PD MAR 26 PY 1997 VL 36 IS 7 BP 1282 EP 1285 DI 10.1021/ic9612966 PG 4 WC Chemistry, Inorganic & Nuclear SC Chemistry GA WQ490 UT WOS:A1997WQ49000003 ER PT J AU Drobyshev, A Mologina, N Shik, V Pobedimskaya, D Yershov, G Mirzabekov, A AF Drobyshev, A Mologina, N Shik, V Pobedimskaya, D Yershov, G Mirzabekov, A TI Sequence analysis by hybridization with oligonucleotide microchip: Identification of beta-thalassemia mutations SO GENE LA English DT Article DE RNA; diagnostics; transcription; discrimination temperature ID GLOBIN GENE; ARRAYS; DNA AB Diagnostics for genetic diseases were run and sequence analysis of DNA was carried out by hybridization of RNA transcripts with oligonucleotide array microchips. Polyacrylamide gel pads (100 x 100 x 20 mu m) were fixed on a glass slide of the microchip and contained allele-specific immobilized oligonucleotides (10-mers). The RNA transcripts of PCR-amplified genomic DNA were fluorescently labeled by enzymatic or chemical methods and hybridized with the microchips. The simultaneous measurement in real time of the hybridization and melting on the entire oligonucleotide array was carried out with a fluorescence microscope equipped with CCD camera. The monitoring of the hybridization specificity for duplexes with different stabilities and AT content was enhanced by its measurement at optimal, discrimination temperatures on melting curves. Microchip diagnostics were optimized by choosing the proper allele-specific oligonucleotides from among the set of overlapping oligomers. The accuracy of mutation detection can be increased by simultaneous hybridization of the microchip with two differently labeled samples and by parallel monitoring their hybridization with a multi-wavelength fluorescence microscope. The efficiency and reliability of the sequence analysis were demonstrated with diagnostics for beta-thalassemia mutations. C1 VA ENGELHARDT MOL BIOL INST,JOINT HUMAN GENOME PROGRAM,MOSCOW 117984,RUSSIA. ARGONNE NATL LAB,CTR MECHANIST BIOL & BIOTECHNOL,JOINT HUMAN GENOME PROGRAM,ARGONNE,IL 60439. NR 18 TC 79 Z9 92 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0378-1119 J9 GENE JI Gene PD MAR 25 PY 1997 VL 188 IS 1 BP 45 EP 52 DI 10.1016/S0378-1119(96)00775-5 PG 8 WC Genetics & Heredity SC Genetics & Heredity GA WR559 UT WOS:A1997WR55900008 PM 9099858 ER PT J AU Henderson, BG Jakosky, BM AF Henderson, BG Jakosky, BM TI Near-surface thermal gradients and mid-IR emission spectra: A new model including scattering and application to real data SO JOURNAL OF GEOPHYSICAL RESEARCH-PLANETS LA English DT Article ID EDDINGTON APPROXIMATION; PLANETARY SURFACES; SPECTROSCOPY; LUNAR; BASALT AB We model the radiative and conductive heat transfer in the top few millimeters of a particulate medium in order to investigate near-surface thermal gradients and their effects on mid-IR emission spectra for different planetary environments. The model extends our previous work by including scattering in the radiative heat transfer. Our results show that significant thermal gradients will form in the top few hundred microns of particulate materials on the surfaces of the Moon and Mercury. Their presence alters spectral contrast and creates emission maxima in the transparent regions of the spectra. The results also show that thermal gradients cause the wavelength position of the Christiansen emission peak to shift by as much as 0.5 mu m with variations in thermal conductivity and grain size, in agreement with previous laboratory investigations. These wavelength shifts are due to increased emission in the transparent regions of the spectrum which are superimposed upon the emissivity signature. The results are applied to telescopic spectra of the surfaces of the Moon and Mercury and can account for certain features seen in these data. Additional calculations show that thermal gradients will be minor on the surface of Mars and negligible for Earth. C1 UNIV COLORADO,ATMOSPHER & SPACE PHYS LAB,BOULDER,CO 80309. UNIV COLORADO,DEPT GEOL SCI,BOULDER,CO 80309. RP Henderson, BG (reprint author), LOS ALAMOS NATL LAB,ASTROPHYS & RADIAT MEASUREMENTS GRP,NIS-2,MS C-323,LOS ALAMOS,NM 87545, USA. NR 39 TC 33 Z9 33 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-PLANET JI J. Geophys. Res.-Planets PD MAR 25 PY 1997 VL 102 IS E3 BP 6567 EP 6580 DI 10.1029/96JE03781 PG 14 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA WR650 UT WOS:A1997WR65000005 ER PT J AU Carpick, RW Ogletree, DF Salmeron, M AF Carpick, RW Ogletree, DF Salmeron, M TI Lateral stiffness: A new nanomechanical measurement for the determination of shear strengths with friction force microscopy SO APPLIED PHYSICS LETTERS LA English DT Article ID ATOMIC-SCALE FRICTION; CAPILLARY CONDENSATION; CONTACT; SURFACE; FILMS AB We present a technique to measure the lateral stiffness of the nanometer-sized contact formed between a friction force microscope tip and a sample surface. Since the lateral stiffness of an elastic contact is proportional to the contact radius, this measurement can be used to study the relationship between friction, load, and contact area. As an example, we measure the lateral stiffness of the contact between a silicon nitride tip and muscovite mica in a humid atmosphere (55% relative humidity) as a function of load. Comparison with friction measurements confirms that friction is proportional to contact area and allows determination of the shear strength. (C) 1997 American Institute of Physics. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV MAT SCI,BERKELEY,CA 94720. UNIV CALIF BERKELEY,DEPT PHYS,BERKELEY,CA 94720. RI Ogletree, D Frank/D-9833-2016 OI Ogletree, D Frank/0000-0002-8159-0182 NR 29 TC 260 Z9 263 U1 11 U2 58 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD MAR 24 PY 1997 VL 70 IS 12 BP 1548 EP 1550 DI 10.1063/1.118639 PG 3 WC Physics, Applied SC Physics GA WP199 UT WOS:A1997WP19900020 ER PT J AU Washburn, NR Stacy, AM Portis, AM AF Washburn, NR Stacy, AM Portis, AM TI Low-temperature, flux-grown, Na-doped LaMnO3: Magnetic properties SO APPLIED PHYSICS LETTERS LA English DT Article ID CA-MN-O; MAGNETORESISTANCE; FILMS AB Crystalline powders of Na-doped LaMnO3 have been precipitated from molten sodium hydroxide at 450 degrees C. Elemental analysis by wavelength dispersive spectroscopy indicates than Na substitutes for Mn giving LaMn1-xNaxO3-delta, with x=0.2. The pseudocubic lattice parameter of 3.916 Angstrom is larger than that of the undoped material, consistent with substitution at the Mn site. Analysis of magnetic susceptibility gives a ferromagnetic Curie-Weiss temperature of 130 K, which is to be compared with the onset of weak ferromagnetism near 300 K. Low-temperature magnetization measurements suggest a model of canted antiferromagnetic clusters. (C) 1997 American Institute of Physics. C1 UNIV CALIF BERKELEY, DEPT CHEM, BERKELEY, CA 94720 USA. UNIV CALIF BERKELEY, LAWRENCE BERKELEY LAB, BERKELEY, CA 94720 USA. UNIV CALIF BERKELEY, DEPT PHYS, BERKELEY, CA 94720 USA. NR 19 TC 13 Z9 13 U1 1 U2 3 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD MAR 24 PY 1997 VL 70 IS 12 BP 1622 EP 1624 DI 10.1063/1.119256 PG 3 WC Physics, Applied SC Physics GA WP199 UT WOS:A1997WP19900045 ER PT J AU Driessen, FAJM Cheong, HM AF Driessen, FAJM Cheong, HM TI High-efficiency energy up-conversion at GaAs-GaInP2 interfaces (vol 70, pg 1628, 1997) SO APPLIED PHYSICS LETTERS LA English DT Article C1 NATL RENEWABLE ENERGY LAB,GOLDEN,CO 80401. RP Driessen, FAJM (reprint author), PHILIPS SEMICOND BV,MOS4YOU,GERSTWEG 2,NL-6534 AE NIJMEGEN,NETHERLANDS. RI Cheong, Hyeonsik/D-7424-2012 OI Cheong, Hyeonsik/0000-0002-2347-4044 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 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD MAR 24 PY 1997 VL 70 IS 12 BP 1630 EP 1630 DI 10.1063/1.118642 PG 1 WC Physics, Applied SC Physics GA WP199 UT WOS:A1997WP19900048 ER PT J AU Okazaki, I Wunderlich, B AF Okazaki, I Wunderlich, B TI Reversible melting in polymer crystals detected by temperature-modulated differential scanning calorimetry SO MACROMOLECULES LA English DT Article ID MOLECULAR SEGREGATION; GLASS-TRANSITION; NUCLEATION; DSC AB A small amount of locally reversible melting and crystallization in poly(ethylene terephthalate) (PET) has been detected by temperature-modulated differential scanning calorimetry (TMDSC). Extended-time TMDSC was used in the quasi-isothermal mode. Studied were melt-crystallized, quenched, and a biaxially-oriented film of PET in temperature steps of 2 K from 320 to 560 K. The integral of the endothermic and exothermic latent heat contributions to the reversible melting and crystallization is less than 10% of the total heat of fusion and decreases further with time over many hours. The new observations support the concept that ''molecular nucleation'' is the reversible and rate-determining step in crystallization. On TMDSC, partially-melted chains remain on the surface of higher-melting crystals to permit crystallization during the cooling cycle without supercooling. C1 UNIV TENNESSEE, DEPT CHEM, KNOXVILLE, TN 37996 USA. OAK RIDGE NATL LAB, DIV CHEM & ANALYT SCI, OAK RIDGE, TN 37831 USA. NR 47 TC 156 Z9 157 U1 2 U2 36 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0024-9297 J9 MACROMOLECULES JI Macromolecules PD MAR 24 PY 1997 VL 30 IS 6 BP 1758 EP 1764 DI 10.1021/ma961539d PG 7 WC Polymer Science SC Polymer Science GA WP909 UT WOS:A1997WP90900031 ER PT J AU Brandenburg, G Briere, RA Kim, DYJ Liu, T Saulnier, M Wilson, R Yamamoto, H Browder, TE Li, F Li, Y Rodriguez, JL Bergfeld, T Eisenstein, BI Ernst, J Gladding, GE Gollin, GD Johnson, E Karliner, I Palmer, M Selen, M Thaler, JJ Edwards, KW Bellerive, A Britton, DI Janicek, R MacFarlane, DB McLean, KW Patel, PM Sadoff, AJ Ammar, R Baringer, P Bean, A Besson, D Coppage, D Darling, C Davis, R Hancock, N Kotov, S Kravchenko, I Kwak, N Anderson, S Kubota, Y Lattery, M ONeill, JJ Patton, S Poling, R Riehle, T Smith, A Savinov, V Alam, MS Athar, SB Ling, Z Mahmood, AH Severini, H Timm, S Wappler, F Anastassov, A Blinov, S Duboscq, JE Fulton, R Fujino, D Gan, KK Hart, T Honscheid, K Kagan, H Kass, R Lee, J Sung, M Undrus, A Wanke, R Wolf, A Zoeller, MM Nemati, B Richichi, SJ Ross, WR Skubic, P Wood, M Bishai, M Fast, J Gerndt, E Hinson, JW Miller, DH Shibata, EI Shipsey, IPJ Yurko, M Gibbons, L Johnson, SD Kwon, Y Roberts, S Thorndike, EH Jessop, CP Lingel, K Marsiske, H Perl, ML Schaffner, SF Ugolini, D Wang, R Zhou, X Coan, TE Fadeyev, V Korolkov, I Maravin, Y Narsky, I Shelkov, V Stroynowski, R Staeck, J Volobouev, I Ye, J Artuso, M Efimov, A Gao, M Goldberg, M Greene, R Frasconi, F He, D Kopp, S Moneti, GC Mountain, R Mukhin, Y Schuh, S Skwarnicki, T Stone, S Xing, X Bartelt, J Csorna, SE Jain, V Marka, S Freyberger, A Godang, R Gibaut, D Kinoshita, K Lai, IC Pomianowski, P Schrenk, S Bonvicini, G Cinabro, D Perera, L Barish, B Chadha, M Chan, S Eigen, G Miller, JS OGrady, C Schmidtler, M Urheim, J Weinstein, AJ Wurthwein, F Asner, DM Bliss, DW Brower, WS Masek, G Paar, HP Gronberg, J Korte, CM Lange, DJ Kutschke, R Menary, S Morrison, RJ Nakanishi, S Nelson, HN Nelson, TK Qiao, C Richman, JD Roberts, D Ryd, A Tajima, H Witherell, MS Balest, R Behrens, BH Cho, K Ford, WT Park, H Rankin, P Roy, J Smith, JG Alexander, JP Bebek, C Berger, BE Berkelman, K Bloom, K Cassel, DG Cho, HA Coffman, DM Crowcroft, DS Dickson, M Drell, PS Ehrlich, R Elia, R Foland, AD Gaidarev, P Gittelman, B Gray, SW Hartill, DL Heltsley, BK Hopman, PI Jones, SL Kandaswamy, J Katayama, N Kim, PC Kreinick, DL Lee, T Liu, Y Ludwig, GS Masui, J Mevissen, J Mistry, NB Ng, CR Nordberg, E Ogg, M Patterson, JR Peterson, D Riley, D Soffer, A Ward, C Avery, P Athanas, M Jones, CD Lohner, M Prescott, C Yang, S Yelton, J Zheng, J AF Brandenburg, G Briere, RA Kim, DYJ Liu, T Saulnier, M Wilson, R Yamamoto, H Browder, TE Li, F Li, Y Rodriguez, JL Bergfeld, T Eisenstein, BI Ernst, J Gladding, GE Gollin, GD Johnson, E Karliner, I Palmer, M Selen, M Thaler, JJ Edwards, KW Bellerive, A Britton, DI Janicek, R MacFarlane, DB McLean, KW Patel, PM Sadoff, AJ Ammar, R Baringer, P Bean, A Besson, D Coppage, D Darling, C Davis, R Hancock, N Kotov, S Kravchenko, I Kwak, N Anderson, S Kubota, Y Lattery, M ONeill, JJ Patton, S Poling, R Riehle, T Smith, A Savinov, V Alam, MS Athar, SB Ling, Z Mahmood, AH Severini, H Timm, S Wappler, F Anastassov, A Blinov, S Duboscq, JE Fulton, R Fujino, D Gan, KK Hart, T Honscheid, K Kagan, H Kass, R Lee, J Sung, M Undrus, A Wanke, R Wolf, A Zoeller, MM Nemati, B Richichi, SJ Ross, WR Skubic, P Wood, M Bishai, M Fast, J Gerndt, E Hinson, JW Miller, DH Shibata, EI Shipsey, IPJ Yurko, M Gibbons, L Johnson, SD Kwon, Y Roberts, S Thorndike, EH Jessop, CP Lingel, K Marsiske, H Perl, ML Schaffner, SF Ugolini, D Wang, R Zhou, X Coan, TE Fadeyev, V Korolkov, I Maravin, Y Narsky, I Shelkov, V Stroynowski, R Staeck, J Volobouev, I Ye, J Artuso, M Efimov, A Gao, M Goldberg, M Greene, R Frasconi, F He, D Kopp, S Moneti, GC Mountain, R Mukhin, Y Schuh, S Skwarnicki, T Stone, S Xing, X Bartelt, J Csorna, SE Jain, V Marka, S Freyberger, A Godang, R Gibaut, D Kinoshita, K Lai, IC Pomianowski, P Schrenk, S Bonvicini, G Cinabro, D Perera, L Barish, B Chadha, M Chan, S Eigen, G Miller, JS OGrady, C Schmidtler, M Urheim, J Weinstein, AJ Wurthwein, F Asner, DM Bliss, DW Brower, WS Masek, G Paar, HP Gronberg, J Korte, CM Lange, DJ Kutschke, R Menary, S Morrison, RJ Nakanishi, S Nelson, HN Nelson, TK Qiao, C Richman, JD Roberts, D Ryd, A Tajima, H Witherell, MS Balest, R Behrens, BH Cho, K Ford, WT Park, H Rankin, P Roy, J Smith, JG Alexander, JP Bebek, C Berger, BE Berkelman, K Bloom, K Cassel, DG Cho, HA Coffman, DM Crowcroft, DS Dickson, M Drell, PS Ehrlich, R Elia, R Foland, AD Gaidarev, P Gittelman, B Gray, SW Hartill, DL Heltsley, BK Hopman, PI Jones, SL Kandaswamy, J Katayama, N Kim, PC Kreinick, DL Lee, T Liu, Y Ludwig, GS Masui, J Mevissen, J Mistry, NB Ng, CR Nordberg, E Ogg, M Patterson, JR Peterson, D Riley, D Soffer, A Ward, C Avery, P Athanas, M Jones, CD Lohner, M Prescott, C Yang, S Yelton, J Zheng, J TI Observation of two excited charmed baryons decaying into Lambda(+)(c)pi(+/-) SO PHYSICAL REVIEW LETTERS LA English DT Article ID POTENTIAL MODELS; SPECTRA; MASSES; STATE AB Using data recorded by the CLEO-II detector at CESR, we report evidence of a pair of excited charmed baryons, one decaying into Lambda(c)(+)pi(+)2 and the other into Lambda(c)(+)pi(-). The doubly charged state has a measured mass difference M(Lambda(c)(+)pi(+)) - M(Lambda(c)(+)) of 234.5 +/- 1.1 +/- 0.8 MeV/c(2) and a width of 17.9(-3.2)(+3.8) +/- 4.0 MeV/c(2), and the neutral state has a measured mass difference M(Lambda(c)(+)pi(-)) - M(Lambda(c)(+)) of 232.6 +/- 1.0 +/- 0.8 MeV/c(2) and a width of 13.0(-3.0)(+3.7) +/- 4.0 MeV/c(2). We interpret these data as evidence of the Sigma(c)8(++) and Sigma c*(0), the spin 3/2(+) excitations of the Sigma(c) baryons. C1 UNIV HAWAII MANOA,HONOLULU,HI 96822. UNIV ILLINOIS,CHAMPAIGN,IL 61801. CARLETON UNIV,OTTAWA,ON K1S 5B6,CANADA. MCGILL UNIV,MONTREAL,PQ H3A 2T8,CANADA. ITHACA COLL,ITHACA,NY 14850. UNIV KANSAS,LAWRENCE,KS 66045. UNIV MINNESOTA,MINNEAPOLIS,MN 55455. SUNY ALBANY,ALBANY,NY 12222. OHIO STATE UNIV,COLUMBUS,OH 43210. UNIV OKLAHOMA,NORMAN,OK 73019. PURDUE UNIV,W LAFAYETTE,IN 47907. UNIV ROCHESTER,ROCHESTER,NY 14627. STANFORD UNIV,STANFORD LINEAR ACCELERATOR CTR,STANFORD,CA 94309. SO METHODIST UNIV,DALLAS,TX 75275. SYRACUSE UNIV,SYRACUSE,NY 13244. VANDERBILT UNIV,NASHVILLE,TN 37235. VIRGINIA POLYTECH INST & STATE UNIV,BLACKSBURG,VA 24061. WAYNE STATE UNIV,DETROIT,MI 48202. CALTECH,PASADENA,CA 91125. UNIV CALIF SAN DIEGO,LA JOLLA,CA 92093. UNIV CALIF SANTA BARBARA,SANTA BARBARA,CA 93106. UNIV COLORADO,BOULDER,CO 80309. CORNELL UNIV,ITHACA,NY 14853. UNIV FLORIDA,GAINESVILLE,FL 32611. BINP,RU-630090 NOVOSIBIRSK,RUSSIA. UNIV TEXAS,AUSTIN,TX 78712. RP Brandenburg, G (reprint author), HARVARD UNIV,CAMBRIDGE,MA 02138, USA. RI Schaffner, Stephen/D-1189-2011; Britton, David/F-2602-2010; Briere, Roy/N-7819-2014; Frasconi, Franco/K-1068-2016 OI Britton, David/0000-0001-9998-4342; Briere, Roy/0000-0001-5229-1039; Frasconi, Franco/0000-0003-4204-6587 NR 29 TC 42 Z9 43 U1 1 U2 1 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD MAR 24 PY 1997 VL 78 IS 12 BP 2304 EP 2308 DI 10.1103/PhysRevLett.78.2304 PG 5 WC Physics, Multidisciplinary SC Physics GA WP513 UT WOS:A1997WP51300008 ER PT J AU Sun, Y Zhang, JY Guidry, M AF Sun, Y Zhang, JY Guidry, M TI Systematic description of yrast superdeformed bands in even-even nuclei of the mass-190 region SO PHYSICAL REVIEW LETTERS LA English DT Article ID ROTATIONAL BANDS; HG-194; MODEL AB Yrast superdeformed bands for even-even nuclei of the mass-190 region are described by the projected shell model. Excellent agreement with available data for all isotopes is obtained. Our calculation of electromagnetic properties and pairing correlations provides a microscopic understanding of the observed gradual increase of dynamical moments of inertia with angular momentum in this mass region and suggests that for superdeformation it is not very meaningful to distinguish between Coriolis antipairing and gradual high-j orbital alignment. C1 UNIV TENNESSEE,DEPT PHYS & ASTRON,KNOXVILLE,TN 37996. OAK RIDGE NATL LAB,DIV PHYS,OAK RIDGE,TN 37831. RP Sun, Y (reprint author), OAK RIDGE NATL LAB,JOINT INST HEAVY ION RES,OAK RIDGE,TN 37831, USA. RI Sun, Yang/P-2417-2015 NR 33 TC 58 Z9 59 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 MAR 24 PY 1997 VL 78 IS 12 BP 2321 EP 2324 DI 10.1103/PhysRevLett.78.2321 PG 4 WC Physics, Multidisciplinary SC Physics GA WP513 UT WOS:A1997WP51300012 ER PT J AU Moeur, WA Day, PK Liu, FC Boyd, STP Adriaans, MJ Duncan, RV AF Moeur, WA Day, PK Liu, FC Boyd, STP Adriaans, MJ Duncan, RV TI Observation of self-organized criticality near the superfluid transition in He-4 SO PHYSICAL REVIEW LETTERS LA English DT Article ID HEAT CURRENT; THERMAL-CONDUCTIVITY; VAPOR-PRESSURE; BARS AB We report on an experimental observation of self-organized criticality in He-4 very close to its superfluid transition. A constant temperature gradient, independent of the heat flux Q through the sample, is created along a vertical column of He-4 by applying heat to the top of the column. This constant temperature gradient equals the gravity-induced gradient in the superfluid transition temperature, indicating that the thermal conductivity of the sample has self-organized. The closeness to criticality in this state is the same throughout most of the sample, and it depends only on Q. C1 CALTECH,JET PROP LAB,PASADENA,CA 91109. SANDIA NATL LABS,ALBUQUERQUE,NM 87185. RP Moeur, WA (reprint author), UNIV NEW MEXICO,DEPT PHYS & ASTRON,ALBUQUERQUE,NM 87131, USA. NR 18 TC 42 Z9 42 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 MAR 24 PY 1997 VL 78 IS 12 BP 2421 EP 2424 DI 10.1103/PhysRevLett.78.2421 PG 4 WC Physics, Multidisciplinary SC Physics GA WP513 UT WOS:A1997WP51300037 ER PT J AU GronbechJensen, N Mashl, RJ Bruinsma, RF Gelbart, WM AF GronbechJensen, N Mashl, RJ Bruinsma, RF Gelbart, WM TI Counterion-induced attraction between rigid polyelectrolytes SO PHYSICAL REVIEW LETTERS LA English DT Article ID DNA; CONDENSATION; CATIONS AB We report on results of long-time Brownian-dynamics simulations of electrostatic interactions between two rigid polyelectrolyte rods. We find that the interaction can be both repulsive, as obtained from mean-held theory, and attractive. The onset of attraction depends not only on the fixed charge density of the rod, but also on its radius. The attractive force is found to be due to the development of positional correlations between the counterions condensed on the two rods, for which we propose a simple analytical model. C1 LOS ALAMOS NATL LAB,DIV THEORET,LOS ALAMOS,NM 87545. UNIV CALIF LOS ANGELES,DEPT CHEM & BIOCHEM,LOS ANGELES,CA 90024. RP GronbechJensen, N (reprint author), UNIV CALIF LOS ANGELES,DEPT PHYS,405 HILGARD AVE,LOS ANGELES,CA 90024, USA. NR 17 TC 358 Z9 361 U1 7 U2 36 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD MAR 24 PY 1997 VL 78 IS 12 BP 2477 EP 2480 DI 10.1103/PhysRevLett.78.2477 PG 4 WC Physics, Multidisciplinary SC Physics GA WP513 UT WOS:A1997WP51300051 ER PT J AU Schenkel, T Briere, MA SchmidtBocking, H Bethge, K Schneider, DH AF Schenkel, T Briere, MA SchmidtBocking, H Bethge, K Schneider, DH TI Electronic sputtering of thin conductors by neutralization of slow highly charged ions SO PHYSICAL REVIEW LETTERS LA English DT Article ID EQUILIBRIUM CHARGE; SURFACE; EMISSION; H+; BOMBARDMENT; DEPENDENCE AB Charge states of slow (upsilon approximate to 0.3 upsilon(Bohr)) highly charged ions (O7+, Ar-16,Ar-18+, Kr33+, Th65+) have been determined after transmission through 10 nm thick amorphous carbon foils. Up to the highest charge states, ions reach charge state equilibrium in the foils within less than 21 fs. High yields of secondary ions are emitted from the foils as a result of the dissipation of tens to hundreds of keV of potential energy during ion neutralization. Positive secondary carbon ion yields increase strongly for q > 25+. Our results demonstrate, for the first time, the occurrence of electronic sputtering in the interaction of slow ions with thin conductors. C1 UNIV FRANKFURT, INST KERNPHYS, D-6000 FRANKFURT, GERMANY. RP LAWRENCE LIVERMORE NATL LAB, PHYS & SPACE TECHNOL DIRECTORATE, LIVERMORE, CA 94550 USA. NR 27 TC 47 Z9 49 U1 0 U2 3 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 EI 1079-7114 J9 PHYS REV LETT JI Phys. Rev. Lett. PD MAR 24 PY 1997 VL 78 IS 12 BP 2481 EP 2484 DI 10.1103/PhysRevLett.78.2481 PG 4 WC Physics, Multidisciplinary SC Physics GA WP513 UT WOS:A1997WP51300052 ER PT J AU Bagger, JA Matchev, KT Pierce, DM Zhang, RJ AF Bagger, JA Matchev, KT Pierce, DM Zhang, RJ TI Gauge and Yukawa coupling unification in models with gauge-mediated supersymmetry breaking (vol 78, pg 1002, 1997) SO PHYSICAL REVIEW LETTERS LA English DT Correction, Addition ID GRAND UNIFICATION; NUCLEON DECAY; SU(5) MODELS; ELECTROWEAK; CONSTANTS; GUTS; SUSY; LEP AB We examine gauge and Yukawa coupling unification in models with gauge-mediated supersymmetry breaking. We work consistently to two-loop order, and include all weak, messenger, and unification-scale threshold corrections. We find that successful unification requires unification-scale threshold corrections that are in conflict with the: minimal SU(5) model, but are consistent with the modified missing-doublet SU(5) model for small tan beta, and large tan beta with mu > 0. C1 STANFORD UNIV,STANFORD LINEAR ACCELERATOR CTR,STANFORD,CA 94309. RP Bagger, JA (reprint author), JOHNS HOPKINS UNIV,DEPT PHYS & ASTRON,BALTIMORE,MD 21218, USA. NR 32 TC 19 Z9 19 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD MAR 24 PY 1997 VL 78 IS 12 BP 2497 EP 2501 DI 10.1103/PhysRevLett.78.2497 PG 5 WC Physics, Multidisciplinary SC Physics GA WP513 UT WOS:A1997WP51300059 ER PT J AU Hasan, A Stengele, KP Giegrich, H Cornwell, P Isham, KR Sachleben, RA Pfleiderer, W Foote, RS AF Hasan, A Stengele, KP Giegrich, H Cornwell, P Isham, KR Sachleben, RA Pfleiderer, W Foote, RS TI Photolabile protecting groups for nucleosides: Synthesis and photodeprotection rates SO TETRAHEDRON LA English DT Article ID SOLID-PHASE SYNTHESIS; TRANSFER RIBONUCLEIC-ACIDS; ORTHO-NITROBENZYL PROTECTION; PHOSPHOTRIESTER APPROACH; 2'-HYDROXYL GROUP; ORGANIC-SYNTHESIS; NUCLEOTIDES; PHOTOLYSIS; SEQUENCE AB o-Nitrobenzyloxycarbonyl and a number of related groups have been tested for the photolabile protection of nucleoside 5'-hydroxyls. The rates of photodeprotection were found to vary by approximately 17 fold in a series of 5'-O-protected thymidine derivatives irradiated at 365 nm under identical conditions. The homologous 2-(o-nitrophenyl)ethoxycarbonyl group and its derivatives were found to be removed approximately 2-fold faster than the corresponding o-nitrobenzyloxycarbonyl group, possibly due to an increased rare of alpha-hydrogen abstraction by the photo-excited nitro group. Photolysis rates were affected by substitutions on both the phenyl ring and alpha-carbon, with the strongest rate enhancements caused by the presence of a methyl or second o-nitrophenyl group in the alpha-position. Among the ring-substituted derivatives studied, o-nitro and o-iodo had the strongest enhancement effects on photodeprotection, while an o-fluoro group reduced the rate of photodeprotection. In general, substitutions at other positions on the phenyl ring had less effect on photolysis rates. (C) 1997 Elsevier Science Ltd. C1 OAK RIDGE NATL LAB,DIV CHEM & ANALYT SCI,OAK RIDGE,TN 37831. OAK RIDGE NATL LAB,DIV BIOL,OAK RIDGE,TN 37831. UNIV KONSTANZ,FAK CHEM,D-78434 CONSTANCE,GERMANY. NR 39 TC 104 Z9 106 U1 2 U2 32 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0040-4020 J9 TETRAHEDRON JI Tetrahedron PD MAR 24 PY 1997 VL 53 IS 12 BP 4247 EP 4264 DI 10.1016/S0040-4020(97)00154-3 PG 18 WC Chemistry, Organic SC Chemistry GA WP257 UT WOS:A1997WP25700012 ER PT J AU Nakano, H Nakayama, K Hirao, K Dupuis, M AF Nakano, H Nakayama, K Hirao, K Dupuis, M TI Transition state barrier height for the reaction H2CO->H-2+CO studied by multireference Moller-Plesset perturbation theory SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID POTENTIAL-ENERGY SURFACE; EXCITED-STATES; FORMALDEHYDE; PHOTODISSOCIATION; SPECTROSCOPY; DISSOCIATION; SINGLET AB The second-order multireference Moller-Plesset-perturbation method (MRMP) was applied to the accurate estimation of the transition state barrier height of H2CO-->H-2+CO reaction. The best estimate for the classical barrier height is 84.5 kcal/mol at the highest level of MRMP theory with the quadruple zeta plus triple polarization basis set and with the active space of 12 electrons in 11 active orbitals. The inclusion of zero-point vibrational energy correction reduces the activation energy to 79.1 kcal/mol, which is in excellent agreement with the experimental value of 79.2 +/- 0.8 kcal/mol [Polik, Guyer, and Moore, J. Chem. Phys. 92, 3453 (1990)]. Analysis of the second-order energies in terms of internal, semi-internal, and external contributions shows that the present MRMP provides a well balanced treatment for the estimation of the energy difference between the equilibrium and transition state structures. (C) 1997 American Institute of Physics. C1 PACIFIC NW LAB, RICHLAND, WA 99352 USA. RP Nakano, H (reprint author), UNIV TOKYO, GRAD SCH ENGN, DEPT APPL CHEM, TOKYO 113, JAPAN. RI Hirao, Kimihiko/N-5483-2015; Nakano, Haruyuki/B-9925-2017 OI Nakano, Haruyuki/0000-0002-7008-0312 NR 22 TC 61 Z9 61 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 MAR 22 PY 1997 VL 106 IS 12 BP 4912 EP 4917 DI 10.1063/1.473540 PG 6 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA WN881 UT WOS:A1997WN88100011 ER PT J AU Kaiser, RI Stranges, D Bevsek, HM Lee, YT Suits, AG AF Kaiser, RI Stranges, D Bevsek, HM Lee, YT Suits, AG TI Crossed-beam reaction of carbon atoms with hydrocarbon molecules .4. Chemical dynamics of methylpropargyl radical formation, C4H5, from reaction of C(P-3(j)) with propylene, C3H6 (X(1)A') SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID ELECTRON-SPIN-RESONANCE; DECOMPOSITION; PARAMETERS; ACETYLENE; FLAMES AB The reaction between ground state carbon atoms and propylene, C3H6, was studied at average collision energies of 23.3 and 45.0 kJ mol(-1) using the crossed molecular beam technique. Product angular distributions and time-of-flight spectra of C4H5 at m/e = 53 were recorded, Forward-convolution fitting of the data yields a maximum energy release as well as angular distributions consistent with the formation of methylpropargyl radicals. Reaction dynamics inferred from the experimental results suggest that the reaction proceeds on the lowest (3)A surface via an initial addition of the carbon atom to the pi-orbital to form a tripler methylcyclopropylidene collision complex followed by ring opening to triplet 1,2-butadiene. With 0.3-0.6 ps, 1,2-butadiene decomposes through carbon-hydrogen bond rupture to atomic hydrogen and methylpropargyl radicals. The explicit identification of C4H5 under single collision conditions represents a further example of a carbon-hydrogen exchange in reactions of ground state carbon with unsaturated hydrocarbons. This versatile machine represents an alternative pathway to build up unsaturated hydrocarbon chains in combustion processes, chemical vapor deposition, and in the interstellar medium. (C) 1997 American Institute of Physics. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV CHEM SCI,BERKELEY,CA 94720. RP Kaiser, RI (reprint author), UNIV CALIF BERKELEY,DEPT CHEM,BERKELEY,CA 94720, USA. RI Lee, Yuan-Tseh/F-7914-2012 NR 42 TC 51 Z9 51 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 MAR 22 PY 1997 VL 106 IS 12 BP 4945 EP 4953 DI 10.1063/1.473543 PG 9 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA WN881 UT WOS:A1997WN88100014 ER PT J AU Pak, Y Woods, RC Peterson, KA AF Pak, Y Woods, RC Peterson, KA TI Coupled cluster spectroscopic properties and isomerization pathway for the cyanate/fulminate isomer pair, NCO-/CNO- SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID CORRELATED MOLECULAR CALCULATIONS; RO-VIBRATIONAL SPECTRA; GAUSSIAN-BASIS SETS; ELECTRON-AFFINITIES; LASER SPECTROSCOPY; WAVE-FUNCTIONS; NEGATIVE-IONS; STATES; INTENSITIES; PROGRAMS AB Three-dimensional near-equilibrium potential energy surfaces and dipole moment functions have been calculated for the ground states of NCO- and CNO-, using the coupled cluster method with single and double substitutions augmented by a perturbative estimate of triple excitations [CCSD(T)] with a quadruple zeta basis set consisting of 150 contracted Gaussian type orbitals. The corresponding equilibrium bond distances at their linear geometries are r(e)(NC) = 1.1934 Angstrom and r(e)(CO) = 1.2306 Angstrom for NCO-, and r(e)(CN) = 1.1866 Angstrom and r(e)(NO) = 1.2741 Angstrom for CNO-. Full three-dimensional variational calculations have also been carried out using the CCSD(T) potential energy and dipole moment functions to determine the rotation-vibrational energy levels and dipole moment matrix elements for both NCO- and CNO-. The predicted band origin of the nu(3) band in the NCO- isomer (2114.4 cm(-1)) agrees well with the gas phase diode laser infrared result (2124.4 cm(-1)). The variational analysis suggests possible revisions in the assignment of the two experimentally observed hot bands which are affected by Fermi resonance. The calculated dipole moments of NCO- and CNO- in their ground vibrational states are 1.504 and 1.482 D, respectively. The CCSD(T) method with a triple zeta basis set was employed to more broadly explore the isomerization path between the two isomers. In agreement with previous lower level calculations a broad and shallow minimum corresponding to a cyclic oxazirine form was found. The immediate vicinity of this local minimum in the potential energy surface and those of the two saddle points separating it from the linear isomers were further refined using the same quadruple zeta basis used for the two near-equilibrium regions. The equilibrium structures and energies of the two neutral isomers, NCO, and CNO, were also calculated at the same level of theory. For NCO, whose photoelectron spectrum has recently been studied in detail, the predicted electron affinity and neutral-ion bond distance changes agree well with the photoelectron results. The reported spectroscopic structure of NCO, however, is not supported by the present CCSD(T) calculations. (C) 1997 American Institute of Physics. C1 WASHINGTON STATE UNIV, DEPT CHEM, RICHLAND, WA 99352 USA. PACIFIC NW LAB, ENVIRONM MOL SCI LAB, RICHLAND, WA 99352 USA. RP Pak, Y (reprint author), UNIV WISCONSIN, DEPT CHEM, MADISON, WI 53706 USA. NR 36 TC 20 Z9 20 U1 1 U2 4 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD MAR 22 PY 1997 VL 106 IS 12 BP 5123 EP 5132 DI 10.1063/1.473557 PG 10 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA WN881 UT WOS:A1997WN88100031 ER PT J AU Zhang, DS Wei, GW Kouri, DJ Hoffman, DK AF Zhang, DS Wei, GW Kouri, DJ Hoffman, DK TI Distributed approximating functional approach to the Fokker-Planck equation: Eigenfunction expansion SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID DISCRETE-ORDINATE METHOD; EIGENVALUES; DIFFUSION; PROPAGATION; DYNAMICS; SYSTEM AB The distributed approximating functional method is applied to the solution of the Fokker-Planck equations. The present approach is limited to the standard eigenfunction expansion method. Three typical examples, a Lorentz Fokker-Planck equation, a bistable diffusion model and a Henon-Heiles two-dimensional anharmonic resonating system, are considered in the present numerical testing. All results are in excellent agreement with those of established methods in the field. It is found that the distributed approximating functional method yields the accuracy of a spectral method but with a local method's simplicity and flexibility for the eigenvalue problems arising from the Fokker-Planck equations. (C) 1997 American Institute of Physics. C1 UNIV HOUSTON, DEPT PHYS, HOUSTON, TX 77204 USA. IOWA STATE UNIV SCI & TECHNOL, DEPT CHEM, AMES, IA 50011 USA. IOWA STATE UNIV SCI & TECHNOL, AMES LAB, AMES, IA 50011 USA. RP UNIV HOUSTON, DEPT CHEM, HOUSTON, TX 77204 USA. RI Wei, Guowei /E-1852-2011 NR 54 TC 21 Z9 21 U1 0 U2 3 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 MAR 22 PY 1997 VL 106 IS 12 BP 5216 EP 5224 DI 10.1063/1.473520 PG 9 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA WN881 UT WOS:A1997WN88100040 ER PT J AU McGraw, R Laaksonen, A AF McGraw, R Laaksonen, A TI Interfacial curvature free energy, the Kelvin relation, and vapor-liquid nucleation rate SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID HOMOGENEOUS NUCLEATION; SIZE AB The interfacial curvature free energy is shown to cause a significant barrier height correction to the classical nucleation rate. This correction is found to be temperature dependent, bur independent of nucleus size. Density functional (DF) calculations are presented for a nonuniform spherical droplet model of the nucleus, Calculations for the surface tension, as a function of nucleus size, and for the interfacial curvature free energy support theoretical predictions and provide an explanation for systematic discrepancies between classical and DF nucleation theories and between the classical theory and experiment. (C) 1997 American Institute of Physics. C1 UNIV HELSINKI,DEPT PHYS,FIN-00014 HELSINKI,FINLAND. RP McGraw, R (reprint author), BROOKHAVEN NATL LAB,DEPT APPL SCI,UPTON,NY 11973, USA. RI Laaksonen, Ari/B-5094-2011 OI Laaksonen, Ari/0000-0002-1657-2383 NR 16 TC 74 Z9 75 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 MAR 22 PY 1997 VL 106 IS 12 BP 5284 EP 5287 DI 10.1063/1.473527 PG 4 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA WN881 UT WOS:A1997WN88100047 ER PT J AU Kaiser, RI Sun, W Suits, AG AF Kaiser, RI Sun, W Suits, AG TI Crossed beam reaction of atomic carbon C(P-3(j)) with hydrogen sulfide, H2S(X(1)A(1)): Observation of the thioformyl radical, HCS(X(2)A') SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID INTERSTELLAR CLOUDS; CHEMISTRY; SULFUR; H2CS; THIOFORMALDEHYDE; ABUNDANCES; MOLECULES; FLAMES; H2S; HCS AB One of the simplest organosulfur reactions, that between ground state carbon atoms, (P-3(j)), and hydrogen sulfide, H2S(X(1)A(1)), was studied at an average collision energy of 21.0 kJ mol(-1) using the crossed molecular beams technique. The product angular distribution and time-of-flight spectra of m/e = 45 ((HCS)-S-32) Were monitored. Forward-convolution fitting of our data yields an almost isotropic center-of-mass angular flux-distribution, whereas the center-of-mass translational energy flux distribution peaks at about 50 kT mol(-1), indicating a tight exit transition state from the decomposing thiohydroxycarbene HCSH complex to the reaction products. The high energy cut-off of the translational energy flux distribution is consistent with the formation of the thioformyl radical HCS in its X(2)A' electronic ground state. The first experimental verification of an existing thiohydroxycarbene intermediate and the rigorous assignment of the HCS radical product under single collision conditions explicitly suggest inclusion of the title reaction in chemical reaction networks of molecular clouds TMC-1 and OMC-1, the outflow of the carbon star IRC+10216, Shoemaker/Levy 9 impact-induced nonequilibrium sulfur chemistry in the Jovian atmosphere, as well as combustion of sulfur containing coal. (C) 1997 American Institute of Physics. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV CHEM SCI,BERKELEY,CA 94720. RP Kaiser, RI (reprint author), UNIV CALIF BERKELEY,DEPT CHEM,BERKELEY,CA 94720, USA. NR 36 TC 27 Z9 27 U1 0 U2 3 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD MAR 22 PY 1997 VL 106 IS 12 BP 5288 EP 5291 DI 10.1063/1.473561 PG 4 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA WN881 UT WOS:A1997WN88100048 ER PT J AU Kobuchi, H DroyLefaix, MT Christen, Y Packer, L AF Kobuchi, H DroyLefaix, MT Christen, Y Packer, L TI Ginkgo biloba extract (EGb 761): Inhibitory effect on nitric oxide production in the macrophage cell line RAW 264.7 SO BIOCHEMICAL PHARMACOLOGY LA English DT Article DE Ginkgo biloba extract; EGb 761; nitric oxide; inducible nitric oxide synthase; macrophages; flavonoids ID PERITONEAL-MACROPHAGES; MOUSE MACROPHAGES; INTERFERON-GAMMA; L-ARGININE; SYNTHASE; INDUCTION; LIPOPOLYSACCHARIDE; BIOSYNTHESIS; HEPATOCYTES; MECHANISMS AB The present study was conducted to evaluate the effect of Ginkgo blloba extract (EGb 761) on the synthesis of nitric oxide (NO) induced by lipopolysaccharide (LPS) plus interferon-gamma (IFN ?I) in the mouse macrophage cell line RAW 264.7. EGb 761 inhibited nitrite and nitrate production, taken as an index for NO, in a concentration-dependent fashion. The IC50 for inhibition of nitrite production by activated macrophages was about 100 mu g/mL EGb 761, The inducible NO synthase (iNOS) enzyme activity of cytosolic preparations from activated RAW 264.7 cells was inhibited by treatment with EGb 761. In addition, reverse transcription-polymerase chain reaction (RT-PCR) analysis revealed that the expression of iNOS mRNA in activated macrophages was suppressed by high concentrations of EGb 761. However, NF-KB DNA binding activity induced by activation with LPS/IFN-gamma was not inhibited by EGb 761. These findings indicate that not only does EGb 761 directly act as an NO scavenger but also, that it inhibits NO production in LPS/IFN-gamma-activated macrophages by concomitant inhibiyion of induction of iNOS mRNA and the enzyme activity of iNOS. Thus, EGb 761 may act as a potent inhibitor of NO production under tissue-damaging inflammatory conditions. (C) 1997 Elsevier Science Inc. C1 UNIV CALIF BERKELEY, LAWRENCE BERKELEY LAB, DIV ENERGY & ENVIRONM, BERKELEY, CA 94720 USA. IPSEN INST, F-75016 PARIS, FRANCE. UNIV CALIF BERKELEY, DEPT MOL & CELL BIOL, MEMBRANE BIOENERGET GRP, BERKELEY, CA 94720 USA. FU NIGMS NIH HHS [GM 27345] NR 34 TC 121 Z9 139 U1 0 U2 6 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0006-2952 J9 BIOCHEM PHARMACOL JI Biochem. Pharmacol. PD MAR 21 PY 1997 VL 53 IS 6 BP 897 EP 903 DI 10.1016/S0006-2952(96)00873-8 PG 7 WC Pharmacology & Pharmacy SC Pharmacology & Pharmacy GA WQ809 UT WOS:A1997WQ80900014 PM 9113109 ER PT J AU Liu, P Liu, J Sayari, A AF Liu, P Liu, J Sayari, A TI Preparation of porous hafnium oxide in the presence of a cationic surfactant SO CHEMICAL COMMUNICATIONS LA English DT Article ID MESOPOROUS MOLECULAR-SIEVES AB A thermally stable mesostructured hafnium oxide is synthesized for the first time. C1 UNIV LAVAL,DEPT CHEM ENGN,ST FOY,PQ G1K 7P4,CANADA. UNIV LAVAL,CERPIC,ST FOY,PQ G1K 7P4,CANADA. PACIFIC NW NATL LAB,RICHLAND,WA 99352. RI Liu, Ping/I-5615-2012 NR 15 TC 54 Z9 56 U1 0 U2 7 PU ROYAL SOC CHEMISTRY PI CAMBRIDGE PA THOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON ROAD, CAMBRIDGE, CAMBS, ENGLAND CB4 4WF SN 1359-7345 J9 CHEM COMMUN JI Chem. Commun. PD MAR 21 PY 1997 IS 6 BP 577 EP 578 DI 10.1039/a607988a PG 2 WC Chemistry, Multidisciplinary SC Chemistry GA WQ733 UT WOS:A1997WQ73300034 ER PT J AU Yu, JP Vassiliev, IR Jung, YS Golbeck, JH McIntosh, L AF Yu, JP Vassiliev, IR Jung, YS Golbeck, JH McIntosh, L TI Strains of Synechocystis sp. PCC 6803 with altered PsaC .1. Mutations incorporated in the cysteine ligands of the two [4Fe-4S] clusters F-A and F-B of photosystem I SO JOURNAL OF BIOLOGICAL CHEMISTRY LA English DT Article ID SYNECHOCOCCUS-SP PCC-6301; SP PCC-6803; ELECTRON-TRANSFER; CORE PROTEIN; SP PCC6803; BINDING; SUBUNIT; COMPLEX; MUTANT; POTENTIALS AB Two [4Fe-4S] clusters, F-A and F-B, function as terminal electron carriers in Photosystem I (PS I), a thylakoid membrane-bound protein-pigment complex. To probe the function of these two clusters in photosynthetic electron transport, site-directed mutants were created in the transformable cyanobacterium Synechocystis sp. PCC 6803. Cysteine ligands in positions 14 or 51 to F-B and F-A, respectively, were replaced with aspartate, serine, or alanine, and the effect on the genetic, physiological, and biochemical characteristics of PS I complexes from the mutant strains were studied. All mutant strains were unable to grow photoautotrophically, and compared with wild type, mixotrophic growth was inhibited under normal light intensity. The mutant cells supported lower rates of whole-chain photosynthetic electron transport. Thylakoids isolated from the aspartate and serine mutants have lower levels of PS I subunits PsaC, PsaD, and PsaE and lower rates of PS I-mediated substrate photoreduction compared with the wild type. The alanine and double aspartate mutants have no detectable levels PsaC, PsaD, and PsaE. Electron transfer rates, measured by cytochrome c(6)-mediated NADP(+) photoreduction, were lower in purified PS I complexes from the aspartate and serine mutants. By measuring the P700(+) kinetics after a single turnover flash, a large percentage of the backreaction in the aspartate and serine mutants was found to be derived from A(1) and F-X, indicating an inefficiency at the F-X --> E(A)/F-B electron transfer step. The alanine and double aspartate mutants failed to show any backreaction from [F-A/F-B](-). These results indicate that the various mutations of the cysteine 14 and 51 ligands to F-B and F-A affect biogenesis and electron transfer differently depending on the type of substitution, and that the effects of mutations on biogenesis and function can be biochemically separated and analyzed. C1 US DOE, PLANT RES LAB, E LANSING, MI 48824 USA. MICHIGAN STATE UNIV, DEPT BIOCHEM, E LANSING, MI 48824 USA. UNIV NEBRASKA, GEORGE W BEADLE CTR, DEPT BIOCHEM, LINCOLN, NE 68588 USA. NR 39 TC 21 Z9 24 U1 0 U2 4 PU AMER SOC BIOCHEMISTRY MOLECULAR BIOLOGY INC PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814-3996 USA SN 0021-9258 EI 1083-351X J9 J BIOL CHEM JI J. Biol. Chem. PD MAR 21 PY 1997 VL 272 IS 12 BP 8032 EP 8039 PG 8 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA WP592 UT WOS:A1997WP59200070 PM 9065476 ER PT J AU Froehlich, JE Keegstra, K AF Froehlich, JE Keegstra, K TI Identification of a translocation intermediate occupying functional protein import sites in the chloroplastic envelope membrane SO JOURNAL OF BIOLOGICAL CHEMISTRY LA English DT Article ID PRECURSOR PROTEIN; SMALL SUBUNIT; RIBULOSE-1,5-BISPHOSPHATE CARBOXYLASE; ESCHERICHIA-COLI; TRANSIT PEPTIDE; FUSION PROTEIN; CONTACT SITES; BINDING; MITOCHONDRIA; TRANSPORT AB We used complexes of avidin and biotinylated precursors to generate translocation intermediates that occupy functional transport sites and thereby block the transport of other precursor proteins into pea chloroplasts. Cysteine residues of purified precursor to the small subunit of rubisco (prSS) were modified with the biotinylation reagent biotin-1-biotinamido-4-[-4'-(maleimidomethyl)-cyclohexane-carboxamido]but Chemically biotinylated prSS was readily imported into chloroplasts. The addition of avidin, however, resulted in the formation of an avidin-biotinylated precursor complex that could not be imported into chloroplasts even when precursors had already engaged the transport apparatus before avidin was added. On fractionation, the avidin-biotinylated precursor complex associated with envelope membranes. Titration of transport sites with avidin-biotinylated precursor complexes revealed that saturation was reached at 2,000 molecules/chloroplast. Even with less than saturating levels of complexes, a sufficient number of translocation sites could be occupied with avidin precursor complexes so that the import rate of freshly added radiolabeled prSS was reduced by 35%. From these observations we conclude that the trapped intermediates were blocking functional translocation sites. These biotinylated translocation intermediates should be useful in future efforts to purify and characterize the chloroplastic protein import machinery. RP Froehlich, JE (reprint author), MICHIGAN STATE UNIV,US DOE,PLANT RES LAB,E LANSING,MI 48823, USA. NR 40 TC 5 Z9 5 U1 0 U2 0 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 MAR 21 PY 1997 VL 272 IS 12 BP 8077 EP 8082 PG 6 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA WP592 UT WOS:A1997WP59200076 PM 9065482 ER PT J AU Qian, H AF Qian, H TI Thermodynamic hierarchy and local energetics of folded proteins SO JOURNAL OF MOLECULAR BIOLOGY LA English DT Article DE conformational substates; denaturation; folding; hydrogen exchange; two-state model ID AMIDE PROTON-EXCHANGE; HYDROGEN-EXCHANGE; STABILITY; MODEL AB The cooperativity of local fluctuations within the folded state of a protein is demonstrated based on applying the ''multiple-probe principle'' to the hydrogen exchange (HX) rates of a set of amide protons of the protein. A hierarchical thermodynamic analysis is presented for the protein energetics, which includes both global two-state folding-unfolding transition and local cooperative fluctuations within the folded state. The analysis dissects the local fluctuations from the global unfolding; both lead to the HX but from the folded and unfolded states, respectively. It provides the newly observed HX behavior of proteins in mild denaturant, namely solvent and temperature dependent HX rates from the folded state, with a quantitative interpretation in terms of a set of local energetic parameters. These local energetic parameters contain much information concerning the structures and stabilities of native proteins. (C) 1997 Academic Press Limited. C1 UNIV CALIF LOS ANGELES,SCH MED,UCLA DOE LAB STRUCT BIOL & MOL MED,LOS ANGELES,CA 90095. RP Qian, H (reprint author), UNIV CALIF LOS ANGELES,SCH MED,DEPT BIOMATH,LOS ANGELES,CA 90095, USA. NR 28 TC 12 Z9 12 U1 0 U2 0 PU ACADEMIC PRESS LTD PI LONDON PA 24-28 OVAL RD, LONDON, ENGLAND NW1 7DX SN 0022-2836 J9 J MOL BIOL JI J. Mol. Biol. PD MAR 21 PY 1997 VL 267 IS 1 BP 198 EP 206 DI 10.1006/jmbi.1996.0839 PG 9 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA WP143 UT WOS:A1997WP14300017 PM 9096218 ER PT J AU Whittum, DH AF Whittum, DH TI Resistive hose instability for arbitrary skin depth SO JOURNAL OF PHYSICS D-APPLIED PHYSICS LA English DT Article ID ELECTRON-BEAM AB Resistive hose growth for moderate or large skin depth differs from that derived from a conductivity model. Asymptotic growth is calculated for the Bennett equilibrium, incorporating the inductive component in the plasma return current, with phase mixing accounted for via the 'distributed-mass' model. Analytic scalings are checked with numerical solutions of the linearized model. For a ratio of skin depth to beam radius of less than 1/10 the conductivity model appears quite adequate. When this ratio exceeds 1/4 inductive corrections appear. RP Whittum, DH (reprint author), STANFORD UNIV,STANFORD LINEAR ACCELERATOR CTR,STANFORD,CA 94309, USA. NR 10 TC 1 Z9 1 U1 0 U2 0 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL, ENGLAND BS1 6BE SN 0022-3727 J9 J PHYS D APPL PHYS JI J. Phys. D-Appl. Phys. PD MAR 21 PY 1997 VL 30 IS 6 BP 1007 EP 1010 DI 10.1088/0022-3727/30/6/014 PG 4 WC Physics, Applied SC Physics GA WR272 UT WOS:A1997WR27200014 ER PT J AU Adler, JO Andersson, BE Blomqvist, KI Fissum, KG Hansen, K Isaksson, L Nilsson, B Nilsson, D Ruijter, H Sandell, A Schroder, B Sims, DA AF Adler, JO Andersson, BE Blomqvist, KI Fissum, KG Hansen, K Isaksson, L Nilsson, B Nilsson, D Ruijter, H Sandell, A Schroder, B Sims, DA TI A broad range tagging spectrometer for the MAX-laboratory SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article AB A broad range tagging spectrometer together with a new beam transport system for photonuclear experiments at the MAX-laboratory in Lund is described. The spectrometer consists of a quadrupole followed by an Elbek-type dipole and has a large momentum acceptance. It can produce both polarized and unpolarized tagged photons in the energy range 10-80 MeV with an energy resolution of about 300 keV. C1 LUND UNIV,DEPT PHYS,S-22362 LUND,SWEDEN. DANFYS AS,DK-4040 JYLLINGE,DENMARK. THOMAS JEFFERSON NATL ACCELERATOR FACIL,NEWPORT NEWS,VA 23606. NR 8 TC 31 Z9 31 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD MAR 21 PY 1997 VL 388 IS 1-2 BP 17 EP 26 DI 10.1016/S0168-9002(97)00347-1 PG 10 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA XC657 UT WOS:A1997XC65700003 ER PT J AU Safranek, J AF Safranek, J TI Experimental determination of storage ring optics using orbit response measurements SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article DE beam-based modeling; orbit response matrix; storage ring; linear optics; coupling AB The measured response matrix giving the change in orbit at beam position monitors (BPMs) with changes in steering magnet excitation can be used to accurately calibrate the linear optics in an electron storage ring [1-8]. A computer code called LOGO (Linear Optics from Closed Orbits) was developed to analyze the NSLS X-Ray Ring measured response matrix to determine: the gradients in all 56 quadrupole magnets; the calibration of the steering magnets and BPMs; the roll of the quadrupoles, steering magnets, and BPMs about the electron beam direction; the longitudinal magnetic centers of the orbit steering magnets; the horizontal dispersion at the orbit steering magnets; and the transverse mis-alignment of the electron orbit in each of the sextupoles. Random orbit measurement error from the BPMs propagated to give only 0.04% rms error in the determination of individual quadrupole gradients and 0.4 mrad rms error in the determination of individual quadrupole rolls. Small variations of a few parts in a thousand in the quadrupole gradients within an individual family were resolved. The optics derived by LOGO gave accurate predictions of the horizontal dispersion, the beta functions, and the horizontal and vertical emittances, and it gave good qualitative agreement with the measured vertical dispersion. The improved understanding of the X-Ray Ring has enabled us to increase the synchrotron radiation brightness. The LOGO code can also be used to find the quadrupole family gradients that best correct for gradient errors in quadrupoles, in sextupoles, and from synchrotron radiation insertion devices. In this way the design periodicity of a storage ring's optics can be restored. An example of periodicity restoration will be presented for the NSLS VUV Ring. LOGO has also produced useful results when applied to the ALS storage ring [8]. RP Safranek, J (reprint author), BROOKHAVEN NATL LAB,NATL SYNCHROTRON LIGHT SOURCE DEPT,UPTON,NY 11973, USA. NR 17 TC 98 Z9 101 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD MAR 21 PY 1997 VL 388 IS 1-2 BP 27 EP 36 DI 10.1016/S0168-9002(97)00309-4 PG 10 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA XC657 UT WOS:A1997XC65700004 ER PT J AU Ajaltouni, Z Albiol, F Alifanov, A Amaral, P Amorim, A Anderson, K Angelini, C Astvatsaturov, A Autiero, D Badaud, F Barreira, G Berglund, S Blanchot, G Blucher, E Blaj, C Bogush, A Bohm, C Boldea, V Borisov, O Bosman, M Bouhemaid, N Brette, P Bromberg, C Brossard, M Budagov, J Caloba, L Carvalho, J Casado, P CavalliSforza, M Cavasinni, V Chadelas, R Chevaleyre, JC ChirikovZorin, I Chlachidze, G Cobal, M Cogswell, F Colaco, F Constantinescu, S Costanzo, D Crouau, M Daudon, F David, M Davidek, T Dawson, J Dugne, JJ De, K DelPrete, T DeSanto, A DiGirolamo, B Dita, S Dolejsi, J Dolezal, Z Downing, R Efthymiopoulos, I Errede, D Errede, S Evans, H Ferrer, A Flaminio, V Gallas, E Gaspar, M Goldemeister, O Glagolev, V Golubev, V Gomes, A Grabsky, V Haney, M Hakopian, H Hellman, S Henriques, A Holmgren, S Honore, PF Huston, J Ivanyushenkov, Y Johansson, E JonAnd, K Juste, A Kakurin, S Karapetian, G Karyukhin, A Khokhlov, Y Klyukhin, V Kolomoets, V Kopikov, S Kostrikov, M Kovtun, V Kukhtin, V Kulagin, M Kulchitsky, Y Lami, S Lapin, V Lazzeroni, C Lebedev, A Leitner, R Li, J Liba, I Lomakin, Y Lomakina, O Lokajicek, M Maio, A Malyukov, S Marroquin, F Martins, JP Mazzoni, E Merritt, F Michel, B Miller, R Minashvili, I Miralles, L Mnatsakanian, E Montarou, G Muanza, GS Nemecek, S Nessi, M Onofre, A Orteu, S Padilla, C Pallin, D Pantea, D Patriarca, J Pereira, A Perlas, JA Pilcher, J Pinhao, J Poggioli, L Poirot, S Price, L Protopopov, Y Proudfoot, J Pukhov, O Reinmuth, G Renzoni, G Richards, R Riu, I Romanov, V Ronceux, B Rumyantsev, V Russakovich, N Sanders, H Santos, J Sawyer, L Says, LP Seixas, JM Sellden, B Semenov, A Senchishin, V Shchelchkov, A Shevtsov, V Shochet, M Sidorov, V Simaitis, V Sissakian, A Solodkov, A Sonderegger, P Soustruznik, K Stanek, R Starchenko, E Stephens, R Studenov, S Suk, M Surkov, A Tang, F Tardell, S Tas, P Teubert, F Thaler, J Tokar, S Topilin, N Trka, Z Turcot, A Turcotte, M Valkar, S Varandas, MJ Vartapetian, A Vazeille, F Vinogradov, V Vorozhtsov, S Wagner, D White, A Wolters, H Yamdagni, N Yarygin, G Yosef, C Zaitsev, A Zdrazil, M AF Ajaltouni, Z Albiol, F Alifanov, A Amaral, P Amorim, A Anderson, K Angelini, C Astvatsaturov, A Autiero, D Badaud, F Barreira, G Berglund, S Blanchot, G Blucher, E Blaj, C Bogush, A Bohm, C Boldea, V Borisov, O Bosman, M Bouhemaid, N Brette, P Bromberg, C Brossard, M Budagov, J Caloba, L Carvalho, J Casado, P CavalliSforza, M Cavasinni, V Chadelas, R Chevaleyre, JC ChirikovZorin, I Chlachidze, G Cobal, M Cogswell, F Colaco, F Constantinescu, S Costanzo, D Crouau, M Daudon, F David, M Davidek, T Dawson, J Dugne, JJ De, K DelPrete, T DeSanto, A DiGirolamo, B Dita, S Dolejsi, J Dolezal, Z Downing, R Efthymiopoulos, I Errede, D Errede, S Evans, H Ferrer, A Flaminio, V Gallas, E Gaspar, M Goldemeister, O Glagolev, V Golubev, V Gomes, A Grabsky, V Haney, M Hakopian, H Hellman, S Henriques, A Holmgren, S Honore, PF Huston, J Ivanyushenkov, Y Johansson, E JonAnd, K Juste, A Kakurin, S Karapetian, G Karyukhin, A Khokhlov, Y Klyukhin, V Kolomoets, V Kopikov, S Kostrikov, M Kovtun, V Kukhtin, V Kulagin, M Kulchitsky, Y Lami, S Lapin, V Lazzeroni, C Lebedev, A Leitner, R Li, J Liba, I Lomakin, Y Lomakina, O Lokajicek, M Maio, A Malyukov, S Marroquin, F Martins, JP Mazzoni, E Merritt, F Michel, B Miller, R Minashvili, I Miralles, L Mnatsakanian, E Montarou, G Muanza, GS Nemecek, S Nessi, M Onofre, A Orteu, S Padilla, C Pallin, D Pantea, D Patriarca, J Pereira, A Perlas, JA Pilcher, J Pinhao, J Poggioli, L Poirot, S Price, L Protopopov, Y Proudfoot, J Pukhov, O Reinmuth, G Renzoni, G Richards, R Riu, I Romanov, V Ronceux, B Rumyantsev, V Russakovich, N Sanders, H Santos, J Sawyer, L Says, LP Seixas, JM Sellden, B Semenov, A Senchishin, V Shchelchkov, A Shevtsov, V Shochet, M Sidorov, V Simaitis, V Sissakian, A Solodkov, A Sonderegger, P Soustruznik, K Stanek, R Starchenko, E Stephens, R Studenov, S Suk, M Surkov, A Tang, F Tardell, S Tas, P Teubert, F Thaler, J Tokar, S Topilin, N Trka, Z Turcot, A Turcotte, M Valkar, S Varandas, MJ Vartapetian, A Vazeille, F Vinogradov, V Vorozhtsov, S Wagner, D White, A Wolters, H Yamdagni, N Yarygin, G Yosef, C Zaitsev, A Zdrazil, M TI Response of the ATLAS Tile calorimeter prototype to muons SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article ID PERFORMANCE AB A study of high energy muons traversing the ATLAS hadron the calorimeter in the barrel region in the energy range between 10 and 300 GeV is presented. Both test beam experimental data and Monte Carlo simulations are given and show good agreement. The Tile calorimeter capability of detecting isolated muons over the above energy range is demonstrated. A signal to background ratio of about 10 is expected for the nominal LHC luminosity (10(34) l/cm(2) s). The photoelectron statistics effect in the muon shape response is shown. The e/mip ratio is found to be 0.81 +/- 0.03; the e/mu ratio is in the range 0.91-0.97. The energy loss of a muon in the calorimeter, dominated by the energy lost in the absorber, can be correlated to the energy loss in the active material. This correlation allows one to correct on an event by event basis the muon energy loss in the calorimeter and therefore reduce the low energy tails in the muon momentum distribution. C1 ARGONNE NATL LAB, ARGONNE, IL 60439 USA. UNIV AUTONOMA BARCELONA, INST FIS ALTES ENERGIES, E-08193 BARCELONA, SPAIN. UNIV CHICAGO, CHICAGO, IL 60637 USA. INST ATOM PHYS, R-76900 BUCHAREST, ROMANIA. UNIV CLERMONT FERRAND, LPC CLERMONT FERRAND, CLERMONT FERRAND, FRANCE. CERN, CH-1211 GENEVA 23, SWITZERLAND. JOINT NUCL RES INST, DUBNA 141980, RUSSIA. UNIV ILLINOIS, CHICAGO, IL 60680 USA. UNIV LISBON, FCUL, P-1699 LISBON, PORTUGAL. UNIV COIMBRA, FCTUC, COIMBRA, PORTUGAL. LIP, COIMBRA, PORTUGAL. MICHIGAN STATE UNIV, E LANSING, MI 48824 USA. INST PHYS ASB, MINSK, BYELARUS. UNIV PISA, PISA, ITALY. IST NAZL FIS NUCL, PISA, ITALY. CHARLES UNIV, PRAGUE, CZECH REPUBLIC. ACAD SCI PRAGUE, PRAGUE, CZECH REPUBLIC. INST HIGH ENERGY PHYS, PROTVINO, RUSSIA. UFRJ, EE, COPPE, RIO DE JANEIRO, BRAZIL. UNIV STOCKHOLM, STOCKHOLM, SWEDEN. IFIC, VALENCIA, SPAIN. UNIV TEXAS, ARLINGTON, TX 76019 USA. YEREVAN PHYS INST, YEREVAN 375036, ARMENIA. RP Ajaltouni, Z (reprint author), LIP, P-1000 LISBON, PORTUGAL. RI David, Mario/C-4664-2012; Klyukhin, Vyacheslav/D-6850-2012; Wolters, Helmut/M-4154-2013; De, Kaushik/N-1953-2013; Nemecek, Stanislav/G-5931-2014; Bosman, Martine/J-9917-2014; Cavalli-Sforza, Matteo/H-7102-2015; Ferrer, Antonio/H-2942-2015; Carvalho, Joao/M-4060-2013; Solodkov, Alexander/B-8623-2017; Zaitsev, Alexandre/B-8989-2017; Karyukhin, Andrey/J-3904-2014; Juste, Aurelio/I-2531-2015; OI Klyukhin, Vyacheslav/0000-0002-8577-6531; Wolters, Helmut/0000-0002-9588-1773; De, Kaushik/0000-0002-5647-4489; Bosman, Martine/0000-0002-7290-643X; Ferrer, Antonio/0000-0003-0532-711X; Carvalho, Joao/0000-0002-3015-7821; Solodkov, Alexander/0000-0002-2737-8674; Zaitsev, Alexandre/0000-0002-4961-8368; Gomes, Agostinho/0000-0002-5940-9893; Sawyer, Lee/0000-0001-8295-0605; Barreira, Gaspar/0000-0001-6373-9441; Karyukhin, Andrey/0000-0001-9087-4315; Maio, Amelia/0000-0001-9099-0009; Lami, Stefano/0000-0001-9492-0147; Juste, Aurelio/0000-0002-1558-3291; Amorim, Antonio/0000-0003-0638-2321; Evans, Harold/0000-0003-2183-3127; Colomer, Kiko Albiol/0000-0002-3824-2246 NR 13 TC 9 Z9 9 U1 2 U2 4 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD MAR 21 PY 1997 VL 388 IS 1-2 BP 64 EP 78 DI 10.1016/S0168-9002(97)00331-8 PG 15 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA XC657 UT WOS:A1997XC65700008 ER PT J AU Athanassopoulos, C Auerbach, LB Bauer, D Bolton, RD Burman, RL Cohen, I Caldwell, DO Dieterle, BD Donahue, JB Eisner, AM Fazely, A Federspiel, FJ Garvey, GT Gray, M Gunasingha, RM Highland, V Imlay, R Johnston, K Kim, HJ Louis, WC Lu, A Margulies, J Mills, GB McIlhany, K Metcalf, W Reeder, RA Sandberg, V Schillaci, M Smith, D Stancu, I Strossman, W Tayloe, R VanDalen, GJ Vernon, W Wang, YX White, DH Whitehouse, D Works, D Xiao, Y Yellin, S AF Athanassopoulos, C Auerbach, LB Bauer, D Bolton, RD Burman, RL Cohen, I Caldwell, DO Dieterle, BD Donahue, JB Eisner, AM Fazely, A Federspiel, FJ Garvey, GT Gray, M Gunasingha, RM Highland, V Imlay, R Johnston, K Kim, HJ Louis, WC Lu, A Margulies, J Mills, GB McIlhany, K Metcalf, W Reeder, RA Sandberg, V Schillaci, M Smith, D Stancu, I Strossman, W Tayloe, R VanDalen, GJ Vernon, W Wang, YX White, DH Whitehouse, D Works, D Xiao, Y Yellin, S TI The liquid scintillator neutrino detector and LAMPF neutrino source SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article ID MUONS AB A search for neutrino oscillations of the type <(nu)over bar (mu)> --> <(nu)over bar (c)> has been conducted at the Los Alamos Meson Physics Facility using <(nu)over bar (mu)> from muon decay at rest, Evidence for this transition has been reported previously. This paper discusses in detail the experimental setup, detector operation and neutrino source, including aspects relevant to oscillation searches in the muon decay-at-rest and pion decay in flight channels. C1 LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545. UNIV CALIF RIVERSIDE,RIVERSIDE,CA 92521. UNIV CALIF SAN DIEGO,SAN DIEGO,CA 92093. UNIV CALIF SANTA BARBARA,SANTA BARBARA,CA 93106. UNIV CALIF STANFORD,INTERCAMPUS INST RES PARTICLE ACCELERATORS,STANFORD,CA 94309. EMBRY RIDDLE AERONAUT UNIV,PRESCOTT,AZ 86301. LINFIELD COLL,MCMINNVILLE,OR 97128. LOUISIANA STATE UNIV,BATON ROUGE,LA 70803. LOUISIANA TECH UNIV,RUSTON,LA 71272. UNIV NEW MEXICO,ALBUQUERQUE,NM 87131. SO UNIV,BATON ROUGE,LA 70813. TEMPLE UNIV,PHILADELPHIA,PA 19122. OI Louis, William/0000-0002-7579-3709 NR 22 TC 101 Z9 101 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD MAR 21 PY 1997 VL 388 IS 1-2 BP 149 EP 172 DI 10.1016/S0168-9002(96)01155-2 PG 24 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA XC657 UT WOS:A1997XC65700017 ER PT J AU Sprunger, PT Petersen, L Plummer, EW Laegsgaard, E Besenbacher, F AF Sprunger, PT Petersen, L Plummer, EW Laegsgaard, E Besenbacher, F TI Giant friedel oscillations on the beryllium(0001) surface SO SCIENCE LA English DT Article ID 2-DIMENSIONAL ELECTRON-GAS; METAL-SURFACES; SCATTERING; BE(0001); DENSITY; WAVES AB Large-amplitude electron density oscillations were observed on a Be(0001) surface by means of variable-temperature scanning tunneling microscopy. Fourier transforms of the images showed a ring of radius 2k(F), where k(F) is the Fermi wave vector of the Be(0001) surface state, This wavelength was expected from Friedel oscillations caused by electronic screening of surface defects, but the amplitude of the waves for energies near the Fermi energy was anomalously large and inconsistent with the Friedel concept of screening. The enhanced amplitude of the waves must be a many-body effect, either in the electron gas (possibly an incipient charge density wave) or in the response of the lattice (electron-phonon coupling). C1 AARHUS UNIV, INST PHYS & ASTRON, DK-8000 AARHUS C, DENMARK. CTR ATOM SCALE MAT PHYS, DK-8000 AARHUS C, DENMARK. UNIV TENNESSEE, DEPT PHYS & ASTRON, KNOXVILLE, TN 37996 USA. OAK RIDGE NATL LAB, DIV SOLID STATE, OAK RIDGE, TN 37831 USA. RI Besenbacher, Flemming/A-9623-2010 NR 37 TC 170 Z9 170 U1 4 U2 41 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 USA SN 0036-8075 J9 SCIENCE JI Science PD MAR 21 PY 1997 VL 275 IS 5307 BP 1764 EP 1767 DI 10.1126/science.275.5307.1764 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA WP056 UT WOS:A1997WP05600032 ER PT J AU Quagliano, JR Stoutland, PO Petrin, RR Sander, RK Romero, RJ Whitehead, MC Quick, CR Tiee, JJ Jolin, LJ AF Quagliano, JR Stoutland, PO Petrin, RR Sander, RK Romero, RJ Whitehead, MC Quick, CR Tiee, JJ Jolin, LJ TI Quantitative chemical identification of four gases in remote infrared (9-11 mu m) differential absorption lidar experiments SO APPLIED OPTICS LA English DT Article DE lidar; CO2 lasers; infrared spectroscopy; plume absorption; remote sensing; partial least squares; differential absorption lidar; chemometrics; optical spectroscopy ID WATER-VAPOR; CALIBRATION METHODS; DIAL MEASUREMENTS; SYSTEM; LASER; REFLECTANCE; OZONE AB A combined experimental and computational approach utilizing tunable CO2 lasers and chemometric analysis was employed to detect chemicals and their concentrations in the field under controlled release conditions. We collected absorption spectra for four organic gases in the laboratory by lasing 40 lines of the laser in the 9.3-10.8 mu m range. The ability to predict properly the chemicals and their respective concentrations depends on the nature of the target, the atmospheric conditions, and the round-trip distance. In 39 of the 45 field experiments, the identities of the released chemicals were identified correctly without predictions of false positives or false negatives. (C) 1997 Optical Society of America. RP Quagliano, JR (reprint author), LOS ALAMOS NATL LAB,DIV CHEM SCI & TECHNOL,LOS ALAMOS,NM 87545, USA. NR 40 TC 15 Z9 15 U1 0 U2 2 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 SN 0003-6935 J9 APPL OPTICS JI Appl. Optics PD MAR 20 PY 1997 VL 36 IS 9 BP 1915 EP 1927 DI 10.1364/AO.36.001915 PG 13 WC Optics SC Optics GA WN598 UT WOS:A1997WN59800013 PM 18250883 ER PT J AU Moran, EC Lehnert, MD AF Moran, EC Lehnert, MD TI The complex broadband X-ray spectrum of the starburst galaxy M82 SO ASTROPHYSICAL JOURNAL LA English DT Article DE galaxies, individual (M82); galaxies, starburst; radiation mechanisms, nonthermal; X-rays, galaxies ID SUPERNOVA-REMNANTS; EMISSION; ABUNDANCES; MASS AB The broadband X-ray spectrum of the prototypical starburst galaxg M82 is very complex. At least three spectral components are required to fit the combined ROSAT and ASCA spectrum in the 0.1-10 keV range. The observed X-ray flux in this band is dominated by a hard Gamma=1.7, heavily absorbed power-law component which originates in the nucleus and near-nuclear disk of the galaxy. Among the candidates for the origin of this hard X-ray emission, the most plausible appears to be inverse-Compton scattered emission from the interaction of the copious infrared photon flux of M82 with supernova-generated relativistic electrons. The measured intrinsic luminosity of the power-law component agrees closely with calculations of the expected inverse-Compton luminosity, Moreover, the radio and X-ray emission in the nucleus of M82 have the same spectral slope, which should be the case if both types of emission are nonthermal and ape associated with a common population of electrons. The other two spectral components, thermal plasmas with characteristic temperatures kT approximate to 0.6 and 0.3 keV, are associated with the star formation and starburst-driven wind in M82. The warmer thermal component is heavily absorbed as well and must also originate in the central region of the galaxy. The softer thermal component, however, is not absorbed, and is likely to represent the X-ray emission that ex;ends along tie minor axis of M82. The amount of absorption required in the three-component model suggests that the intrinsic luminosity of M82 in the 0.1-10 keV band is about four times greater than its observed luminosity of 4 x 10(40) ergs s(-1). RP Moran, EC (reprint author), LAWRENCE LIVERMORE NATL LAB,INST GEOPHYS & PLANETARY PHYS,L-413,LIVERMORE,CA 94550, USA. NR 32 TC 54 Z9 54 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 S WOODLAWN AVE, CHICAGO, IL 60637 SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD MAR 20 PY 1997 VL 478 IS 1 BP 172 EP 181 DI 10.1086/303795 PN 1 PG 10 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA WN497 UT WOS:A1997WN49700019 ER PT J AU Woloschak, GE Schreck, S Panozzo, J ChangLiu, CM Libertin, CR AF Woloschak, GE Schreck, S Panozzo, J ChangLiu, CM Libertin, CR TI HIV expression is induced in dying cells SO BIOCHIMICA ET BIOPHYSICA ACTA-GENE STRUCTURE AND EXPRESSION LA English DT Article DE apoptosis; DNA damage; HIV-LTR expression; radiation; stress ID HUMAN-IMMUNODEFICIENCY-VIRUS; LONG TERMINAL REPEAT; ULTRAVIOLET-RADIATION; GENE-EXPRESSION; TYPE-1; ACTIVATION; DEATH; INFECTION; APOPTOSIS AB Using HeLa cells stably transfected with an HIV-LTR-CAT construct, we demonstrated a peak in CAT induction that occurs in viable (but not necessarily cell-division-competent) cells 24 h following exposure to some cell-killing agents. gamma rays were the only cell-killing agent which did not induce HIV transcription; this can be attributed to the fact that gamma-ray-induced apoptotic death requires functional p53, which is not present in HeLa cells. For all other agents, HIV-LTR induction was dose-dependent and correlated with the amount of cell killing that occurred in the culture. Doses which caused over 99% cell killing induced HIV-LTR transcription maximally, demonstrating that cells that will go on to die by 14 days an the cells expressing HIV-LTR-CAT. C1 UNIV S CAROLINA,DEPT CHEM,COLUMBIA,SC 29208. LOYOLA UNIV,MED CTR,DEPT PATHOL,MAYWOOD,IL 60153. LOYOLA UNIV,MED CTR,DEPT MED,MAYWOOD,IL 60153. RP Woloschak, GE (reprint author), ARGONNE NATL LAB,CTR MECHANIST BIOL & BIOTECHNOL,9700 S CASS AVE,ARGONNE,IL 60439, USA. RI Woloschak, Gayle/A-3799-2017 OI Woloschak, Gayle/0000-0001-9209-8954 FU NIEHS NIH HHS [ES07141] NR 19 TC 5 Z9 5 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0167-4781 J9 BBA-GENE STRUCT EXPR JI Biochim. Biophys. Acta-Gene Struct. Expression PD MAR 20 PY 1997 VL 1351 IS 1-2 BP 105 EP 110 DI 10.1016/S0167-4781(96)00184-4 PG 6 WC Biochemistry & Molecular Biology; Biophysics SC Biochemistry & Molecular Biology; Biophysics GA WP451 UT WOS:A1997WP45100014 PM 9116023 ER PT J AU Coen, CJ Prausnitz, JM Blanch, HW AF Coen, CJ Prausnitz, JM Blanch, HW TI Protein salting-out: Phase equilibria in two-protein systems SO BIOTECHNOLOGY AND BIOENGINEERING LA English DT Article DE salting out; precipitation; protein separation; protein association; lysozyme; alpha-chymotrypsin; ovalbumin ID PRECIPITATION; SOLUBILITY; OVALBUMIN; LYSOZYME; MIXTURES AB The phase behavior of two aqueous binary protein mixtures, lysozyme-chymotrypsin and lysozyme-ovalbumin, was determined in ammonium sulfate solutions. Protein concentrations were determined in both phases as a function of pH and ionic strength. For lysozyme-chymotrypsin mixtures, the observed phase behavior was similar to that for each individual protein; the presence of the second protein had little influence. The phase behavior of lysozyme-ovalbumin mixtures, however, was different from that of the respective single-protein systems. Lysozyme and ovalbumin are found together in egg whites; their association is both pH and ionic-strength dependent. The association of proteins is a key determinant of protein solubility in salt solutions. (C) 1997 John Wiley & Sons, Inc. C1 UNIV CALIF BERKELEY, DEPT CHEM ENGN, BERKELEY, CA 94720 USA. UNIV CALIF BERKELEY, LAWRENCE BERKELEY LAB, DIV CHEM SCI, BERKELEY, CA 94720 USA. NR 32 TC 19 Z9 19 U1 0 U2 6 PU WILEY-BLACKWELL PI MALDEN PA COMMERCE PLACE, 350 MAIN ST, MALDEN 02148, MA USA SN 0006-3592 J9 BIOTECHNOL BIOENG JI Biotechnol. Bioeng. PD MAR 20 PY 1997 VL 53 IS 6 BP 567 EP 574 PG 8 WC Biotechnology & Applied Microbiology SC Biotechnology & Applied Microbiology GA WL036 UT WOS:A1997WL03600004 PM 18634057 ER PT J AU Jones, MT Plassmann, PE AF Jones, MT Plassmann, PE TI Adaptive refinement of unstructured finite-element meshes SO FINITE ELEMENTS IN ANALYSIS AND DESIGN LA English DT Article ID BISECTION; STRATEGY; COMPUTATIONS; ALGORITHMS; MATRICES; SHAPE AB The finite-element method used in conjunction with adaptive mesh refinement algorithms can be an efficient tool in many scientific and engineering applications. In this paper we review algorithms for the adaptive refinement of unstructured simplicial meshes (triangulations and tetrahedralizations). We discuss bounds on the quality of the meshes resulting from these refinement algorithms. Unrefinement and refinement along curved surfaces are also discussed. Finally, we give an overview of recent developments in parallel refinement algorithms. C1 ARGONNE NATL LAB,DIV MATH & COMP SCI,ARGONNE,IL 60439. UNIV TENNESSEE,DEPT COMP SCI,KNOXVILLE,TN 37996. NR 40 TC 27 Z9 29 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-874X J9 FINITE ELEM ANAL DES JI Finite Elem. Anal. Des. PD MAR 20 PY 1997 VL 25 IS 1-2 BP 41 EP 60 DI 10.1016/S0168-874X(96)00039-X PG 20 WC Mathematics, Applied; Mechanics SC Mathematics; Mechanics GA WP902 UT WOS:A1997WP90200004 ER PT J AU Moune, OK Edelstein, N Piriou, B Alves, MG Faucher, MD AF Moune, OK Edelstein, N Piriou, B Alves, MG Faucher, MD TI Optical absorption spectrum, oscillator strengths, magnetic splitting factors and paramagnetic susceptibility of Nd3+ doped into LiYO2 SO JOURNAL OF ALLOYS AND COMPOUNDS LA English DT Article; Proceedings Paper CT 21st Rare Earth Research Conference CY JUL 07-12, 1996 CL DULUTH, MN SP Rare Earth Res Conf Inc, Univ Minnesota, USR Optonix Inc, Amer Chem Soc, Petr Res Fund, Arris Int Corp, Baotou Steel & Rare Earth Co, US DE LiYO2; neodymium doping; optical properties; magnetic properties; crystal field analysis; oscillator strengths ID CRYSTAL-FIELD PARAMETERS; RARE-EARTH COMPOUNDS; INTENSITY PARAMETERS; TRANSITION; MODEL; ND-3+ AB Optical and magnetic measurements an performed on Nd3+ doped into LiYO2. 105 energy levels of Nd3+ are assigned from the optical absorption and excitation spectra for the powdered sample at 20 K. The crystal field analysis is performed in the C-1 site symmetry of Nd3+. Theoretical values of the crystal field parameters, oscillator strengths, magnetic susceptibility and ground state splitting factors are calculated and compared with experimentally measured quantities. C1 ECOLE CENT PARIS,LAB CHIM & PHYSICOCHIM MOL & MINERALE,CNRS,URA 1907,F-92295 CHATENAY MALABR,FRANCE. UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV CHEM SCI,BERKELEY,CA 94720. NR 27 TC 3 Z9 3 U1 0 U2 1 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0925-8388 J9 J ALLOY COMPD JI J. Alloy. Compd. PD MAR 20 PY 1997 VL 250 IS 1-2 BP 310 EP 315 DI 10.1016/S0925-8388(96)02543-1 PG 6 WC Chemistry, Physical; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Chemistry; Materials Science; Metallurgy & Metallurgical Engineering GA XD794 UT WOS:A1997XD79400008 ER PT J AU Liu, GK Beitz, JV Huang, J Abraham, MM Boatner, LA AF Liu, GK Beitz, JV Huang, J Abraham, MM Boatner, LA TI Characterization of crystal field and nuclear quadrupole interactions in the D-5(1) state of Am-243(3+) in LaCl3 and CaWO4 SO JOURNAL OF ALLOYS AND COMPOUNDS LA English DT Article; Proceedings Paper CT 21st Rare Earth Research Conference CY JUL 07-12, 1996 CL DULUTH, MN SP Rare Earth Res Conf Inc, Univ Minnesota, USR Optonix Inc, Amer Chem Soc, Petr Res Fund, Arris Int Corp, Baotou Steel & Rare Earth Co, US DE crystal field interaction; hyperfine structure; Am3+:LaCl3; Am3+:CaWO4 ID TRIVALENT EUROPIUM; AMERICIUM(III); FLUORESCENCE; LUMINESCENCE; AM-3+; GLASS AB The crystal field splitting and hyperfine energy level structure in the first D-5(1) excited state of Am-243(3+) in LaCl3 and CaWO4 have been studied using selective laser excitation, Zeeman and spectral hole burning experiments. Two crystal field levels and associated vibronic structures were observed in the electric dipole forbidden F-7(0) <-> D-5(1) transition, that has a very weak magnetic dipole moment. The hyperfine energy level structure, including nuclear quadrupole splitting, was resolved in spectral hole burning studies. The existing free ion and crystal field interaction model provides a consistent interpretation of the observed ordering of crystal field levels and the magnitude of the nuclear quadrupole splitting of Am-243(3+) in CaWO4, whereas a discrepancy between the model and experimental results is encountered for Am-243(3+) in LaCl3. 4 discussion on the relationship between nuclear quadrupole interaction and free ion modeling is given. C1 UNIV WISCONSIN,DEPT PHYS & ASTRON,EAU CLAIRE,WI 54702. OAK RIDGE NATL LAB,DIV SOLID STATE,OAK RIDGE,TN 37831. RP Liu, GK (reprint author), ARGONNE NATL LAB,DIV CHEM,9700 S CASS AVE,ARGONNE,IL 60439, USA. RI Boatner, Lynn/I-6428-2013 OI Boatner, Lynn/0000-0002-0235-7594 NR 23 TC 3 Z9 3 U1 0 U2 3 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0925-8388 J9 J ALLOY COMPD JI J. Alloy. Compd. PD MAR 20 PY 1997 VL 250 IS 1-2 BP 347 EP 351 DI 10.1016/S0925-8388(96)02548-0 PG 5 WC Chemistry, Physical; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Chemistry; Materials Science; Metallurgy & Metallurgical Engineering GA XD794 UT WOS:A1997XD79400015 ER PT J AU Loong, CK Liu, GK Ozawa, M Suzuki, S AF Loong, CK Liu, GK Ozawa, M Suzuki, S TI A laser spectroscopic study of Nd-doped zirconia SO JOURNAL OF ALLOYS AND COMPOUNDS LA English DT Article; Proceedings Paper CT 21st Rare Earth Research Conference CY JUL 07-12, 1996 CL DULUTH, MN SP Rare Earth Res Conf Inc, Univ Minnesota, USR Optonix Inc, Amer Chem Soc, Petr Res Fund, Arris Int Corp, Baotou Steel & Rare Earth Co, US DE site-selective spectroscopy; fluorescence; rare-earth modified zirconia; zirconia catalytic support AB High-surface-area rare-earth (RE) modified zirconia powders prepared by solution methods can be used as catalytic support of noble metals and as electrolyte oxygen sensors in an automobile exhaust-emission-control system. A previous neutron-scattering study showed that substituting zirconium with trivalent RE ions not only stabilizes the cubic and tetragonal phases over a wide range of temperatures, but also creates oxygen vacancies in the RE-Zr oxide solid solution. This work focuses on the fluorescence of Nd in Nd0.1Zr0.9O1.95 powders under laser excitation of the Nd3+ ground state to the (4)G(7/2) states. Distinct features were observed at 8 K in the I-4(9/2) --> (4)G(7/2) excitation and F-4(3/2) --> I-4(9/2) emission spectra using two sets of incident and emission frequencies, respectively. The results are discussed in terms of site-sensitive local structures surrounding the Nd ions in the two-phased oxide structure. C1 NAGOYA INST TECHNOL,TAJIMI,GIFU 507,JAPAN. RP Loong, CK (reprint author), ARGONNE NATL LAB,9700 S CASS AVE,ARGONNE,IL 60439, USA. NR 6 TC 3 Z9 3 U1 0 U2 4 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0925-8388 J9 J ALLOY COMPD JI J. Alloy. Compd. PD MAR 20 PY 1997 VL 250 IS 1-2 BP 352 EP 355 DI 10.1016/S0925-8388(96)02549-2 PG 4 WC Chemistry, Physical; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Chemistry; Materials Science; Metallurgy & Metallurgical Engineering GA XD794 UT WOS:A1997XD79400016 ER PT J AU Loong, CK Richardson, JW Ozawa, M AF Loong, CK Richardson, JW Ozawa, M TI Structural phase transformations of rare-earth modified transition alumina to corundum SO JOURNAL OF ALLOYS AND COMPOUNDS LA English DT Article; Proceedings Paper CT 21st Rare Earth Research Conference CY JUL 07-12, 1996 CL DULUTH, MN SP Rare Earth Res Conf Inc, Univ Minnesota, USR Optonix Inc, Amer Chem Soc, Petr Res Fund, Arris Int Corp, Baotou Steel & Rare Earth Co, US DE rare-earth doped alumina; neutron diffraction; alumina supported catalysts; transition aluminas AB The effect of rare-earth dopant on transformations of the gamma-->theta-->alpha phases in fine alumina powders under vacuum was investigated by in situ neutron diffraction from 500 to 1300 degrees C. La-doped (1 mol%) Al2O3 powders (surface area similar to 170 m(2)/g) were prepared by an impregnation technique. Below 800 degrees C both samples contain a dominant gamma-phase. Above 1000 degrees C, transformation of the gamma-phase to the intermediate theta-phase, and then completely to the alpha-phase (corundum) was observed. Addition of 1 mol% of La in Al2O3 effectively shifts the alpha-phase formation temperature from similar to 1125 degrees C for pure alumina to similar to 1250 degrees C, probably due to the larger size of La compared to Al ions, which hinders ionic diffusion in the processes of sintering and transformation. Consequently, doping La in alumina improves the surface-area and thermal stability at high temperatures, which is important for catalytic applications. C1 NAGOYA INST TECHNOL,TAJIMI,GIFU 507,JAPAN. RP Loong, CK (reprint author), ARGONNE NATL LAB,9700 S CASS AVE,ARGONNE,IL 60439, USA. NR 10 TC 29 Z9 29 U1 2 U2 10 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0925-8388 J9 J ALLOY COMPD JI J. Alloy. Compd. PD MAR 20 PY 1997 VL 250 IS 1-2 BP 356 EP 359 DI 10.1016/S0925-8388(96)02550-9 PG 4 WC Chemistry, Physical; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Chemistry; Materials Science; Metallurgy & Metallurgical Engineering GA XD794 UT WOS:A1997XD79400017 ER PT J AU Beitz, JV Williams, CW AF Beitz, JV Williams, CW TI Uranyl fluoride luminescence in acidic aqueous solutions SO JOURNAL OF ALLOYS AND COMPOUNDS LA English DT Article; Proceedings Paper CT 21st Rare Earth Research Conference CY JUL 07-12, 1996 CL DULUTH, MN SP Rare Earth Res Conf Inc, Univ Minnesota, USR Optonix Inc, Amer Chem Soc, Petr Res Fund, Arris Int Corp, Baotou Steel & Rare Earth Co, US DE uranyl; luminescence; speciation; uranium analysis; uranyl fluoride ID IONS AB Luminescence emission spectra and decay rates are reported for uranyl species in acidic aqueous solutions containing HF or added NaF. The longest luminescence lifetime, 0.269 +/- 0.006 ms, was observed from uranyl in 1 M HF + 1 M HClO4, at 296 K and decreased with increasing temperature. Based on a luminescence dynamics model that assumes equilibrium among electronically excited uranyl fluoride species and free fluoride ion, this long lived uranyl luminescence in aqueous solution is attributed primarily to UO2F2. Studies on the effect of added LiNO3 or Na2WO4 . 2H(2)O showed relatively weak quenching of uranyl fluoride luminescence which suggests that high sensitivity determination of the UF6 content of WF6 gas should be feasible via uranyl luminescence analysis of hydrolyzed gas samples of impure WF6. RP Beitz, JV (reprint author), ARGONNE NATL LAB,DIV CHEM,9700 S CASS AVE,ARGONNE,IL 60439, USA. NR 19 TC 13 Z9 13 U1 0 U2 5 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0925-8388 J9 J ALLOY COMPD JI J. Alloy. Compd. PD MAR 20 PY 1997 VL 250 IS 1-2 BP 375 EP 379 DI 10.1016/S0925-8388(96)02753-3 PG 5 WC Chemistry, Physical; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Chemistry; Materials Science; Metallurgy & Metallurgical Engineering GA XD794 UT WOS:A1997XD79400021 ER PT J AU Unrecht, B Jank, S Reddmann, H Amberger, HD Edelmann, FT Edelstein, NM AF Unrecht, B Jank, S Reddmann, H Amberger, HD Edelmann, FT Edelstein, NM TI The electronic structure of organometallic complexes of the f elements .41. Crystal field strength of eta(8)-cyclooctatetraenyl ligand estimated on the basis of the preliminary crystal field parameters of (COT)Nd-III[HB(3,5-Me(2)pz)(3)] SO JOURNAL OF ALLOYS AND COMPOUNDS LA English DT Article; Proceedings Paper CT 21st Rare Earth Research Conference CY JUL 07-12, 1996 CL DULUTH, MN SP Rare Earth Res Conf Inc, Univ Minnesota, USR Optonix Inc, Amer Chem Soc, Petr Res Fund, Arris Int Corp, Baotou Steel & Rare Earth Co, US DE crystal field strength; eta(8)-cyclooctatetraenyl ligand ID ABSORPTION-SPECTRUM AB The absorption spectrum of (eta(8)-COT)Nd[HB(3,5-Me(2)pz)(3)] (COT=cyclooctatetraenyl, pz=pyrazol-1-yl) has been measured at room temperature, at approximately 90 K and in parts at ca. 30 K. The bands were assigned by applying the selection rules for C-8v symmetry and by performing crystal field (CF) calculations assuming the CF parameters of the Nd complex were the same as for the previously analyzed (COT)Pr[HB(3,5-Me(2)pz)(3)]. The parameters of an empirical Hamiltonian were fitted to the energies of 27 levels to give an r.m.s. deviation of 25.5 cm(-1). Neglecting the influence of [HB(3,5-Me(2)pz)(3)](-) ligand, the CF strength of the [COT](--) ligand could be estimated from the CF parameters obtained. C1 UNIV HAMBURG,INST ANORGAN & ANGEW CHEM,D-20146 HAMBURG,GERMANY. UNIV MAGDEBURG,INST CHEM,D-39106 MAGDEBURG,GERMANY. UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV CHEM SCI,BERKELEY,CA 94720. RI Edelmann, Frank /E-6626-2013 NR 18 TC 17 Z9 17 U1 0 U2 0 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0925-8388 J9 J ALLOY COMPD JI J. Alloy. Compd. PD MAR 20 PY 1997 VL 250 IS 1-2 BP 383 EP 386 DI 10.1016/S0925-8388(96)02553-4 PG 4 WC Chemistry, Physical; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Chemistry; Materials Science; Metallurgy & Metallurgical Engineering GA XD794 UT WOS:A1997XD79400023 ER PT J AU Hinatsu, Y Edelstein, N AF Hinatsu, Y Edelstein, N TI Electron paramagnetic resonance spectra of Pr4+ ions doped in BaMO3 (M=Ce, Zr, Sn) and SrCeO3 SO JOURNAL OF ALLOYS AND COMPOUNDS LA English DT Article; Proceedings Paper CT 21st Rare Earth Research Conference CY JUL 07-12, 1996 CL DULUTH, MN SP Rare Earth Res Conf Inc, Univ Minnesota, USR Optonix Inc, Amer Chem Soc, Petr Res Fund, Arris Int Corp, Baotou Steel & Rare Earth Co, US DE EPR spectroscopy; perovskite oxides; praseodymium doping; magnetic properties AB The isotropic electron paramagnetic resonance (EPR) spectra of powders with Pr4+ doped in BaMO3 (M = Ce, Zr, Sn) were measured at 4.2 K. A very large hyperfine interaction with the Pr-141 nucleus was observed. The results were analyzed based on the weak field approximation, and the g values and hyperfine coupling constants A were obtained. The measured g values are much smaller than \-10/7\, showing that the crystal field effect on the behavior of a 4f electron is large. The value of \g\ decreases from 0.741 (Pr4+/BaCeO3) to 0.583 (Pr4+-BaSnO3), which is caused by the increase of the crystal field due to the shrinking of the lattice. In contrast, the hyperfine coupling constants are almost constant: A = 0.060(1) cm(-1). The anisotropic EPR spectra were measured for the case of Pr4+/SrCeO3, which indicates that the octahedral array of oxygen ions about Pr4+ is considerably distorted for this system. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV CHEM SCI,BERKELEY,CA 94720. RP Hinatsu, Y (reprint author), HOKKAIDO UNIV,GRAD SCH SCI,DIV CHEM,SAPPORO,HOKKAIDO 060,JAPAN. NR 13 TC 5 Z9 5 U1 3 U2 7 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0925-8388 J9 J ALLOY COMPD JI J. Alloy. Compd. PD MAR 20 PY 1997 VL 250 IS 1-2 BP 400 EP 404 DI 10.1016/S0925-8388(96)02557-1 PG 5 WC Chemistry, Physical; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Chemistry; Materials Science; Metallurgy & Metallurgical Engineering GA XD794 UT WOS:A1997XD79400027 ER PT J AU Antonio, MR Soderholm, L Ellison, AJG AF Antonio, MR Soderholm, L Ellison, AJG TI Local environments of erbium and lutetium in sodium silicate glasses SO JOURNAL OF ALLOYS AND COMPOUNDS LA English DT Article; Proceedings Paper CT 21st Rare Earth Research Conference CY JUL 07-12, 1996 CL DULUTH, MN SP Rare Earth Res Conf Inc, Univ Minnesota, USR Optonix Inc, Amer Chem Soc, Petr Res Fund, Arris Int Corp, Baotou Steel & Rare Earth Co, US DE local environments; erbium; lutetium ID X-RAY-ABSORPTION; FINE-STRUCTURE; COORDINATION ENVIRONMENTS; EDGE SPECTROSCOPY; OXIDE SYSTEM; SCATTERING; XANES; YB AB The coordination environments of Er and Lu in sodium silicate glasses are probed through a unique analysis of L-3 X-ray absorption near edge structure (XANES) combined with extended X-ray absorption fine structure (EXAFS). By using the observed splitting of the empty 5d manifold of the lanthanides in combination with the EXAFS data, we demonstrate that Er and Lu are 6-coordinate in well-defined sites with relatively high symmetry. RP Antonio, MR (reprint author), ARGONNE NATL LAB,9700 S CASS AVE,ARGONNE,IL 60439, USA. NR 25 TC 20 Z9 20 U1 3 U2 7 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0925-8388 J9 J ALLOY COMPD JI J. Alloy. Compd. PD MAR 20 PY 1997 VL 250 IS 1-2 BP 536 EP 540 DI 10.1016/S0925-8388(96)02736-3 PG 5 WC Chemistry, Physical; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Chemistry; Materials Science; Metallurgy & Metallurgical Engineering GA XD794 UT WOS:A1997XD79400052 ER PT J AU Antonio, MR Soderholm, L AF Antonio, MR Soderholm, L TI Implications of the unusual redox behavior exhibited by the heteropolyanion [EuP5W30O110](12-) SO JOURNAL OF ALLOYS AND COMPOUNDS LA English DT Article; Proceedings Paper CT 21st Rare Earth Research Conference CY JUL 07-12, 1996 CL DULUTH, MN SP Rare Earth Res Conf Inc, Univ Minnesota, USR Optonix Inc, Amer Chem Soc, Petr Res Fund, Arris Int Corp, Baotou Steel & Rare Earth Co, US DE redox behavior; heteropolyanion [EuP5W30O110](12-) ID X-RAY-ABSORPTION; VALENCE; SPECTROSCOPY AB We report on the novel electrochemical behavior of the heteropolyanion [EuP5W30O110](12-), with specific emphasis on the valence of Eu in both the oxidized and reduced forms of the anion. In aqueous electrolytes, the P-W-O framework is electroactive, and can reversibly accept up to 10 electrons before the potential becomes reducing enough for H-2 evolution. Europium L-3-edge X-ray absorption near edge structure (XANES) results demonstrate that Eu is also electroactive under the same conditions. The implications of this work will be discussed in terms of their contribution to long-standing questions about intermediate-valent materials. RP Antonio, MR (reprint author), ARGONNE NATL LAB,DIV CHEM,9700 S CASS AVE,ARGONNE,IL 60439, USA. OI Antonio, Mark/0000-0002-1208-4534 NR 14 TC 23 Z9 23 U1 0 U2 3 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0925-8388 J9 J ALLOY COMPD JI J. Alloy. Compd. PD MAR 20 PY 1997 VL 250 IS 1-2 BP 541 EP 543 DI 10.1016/S0925-8388(96)02737-5 PG 3 WC Chemistry, Physical; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Chemistry; Materials Science; Metallurgy & Metallurgical Engineering GA XD794 UT WOS:A1997XD79400053 ER PT J AU Nipko, JC Loong, CK Kern, S Abraham, MM Boatner, LA AF Nipko, JC Loong, CK Kern, S Abraham, MM Boatner, LA TI Crystal field splitting and anomalous thermal expansion in YbVO4 SO JOURNAL OF ALLOYS AND COMPOUNDS LA English DT Article; Proceedings Paper CT 21st Rare Earth Research Conference CY JUL 07-12, 1996 CL DULUTH, MN SP Rare Earth Res Conf Inc, Univ Minnesota, USR Optonix Inc, Amer Chem Soc, Petr Res Fund, Arris Int Corp, Baotou Steel & Rare Earth Co, US DE crystal fields; thermal expansion; rare-earth orthovanadate ID EARTH ENERGY-LEVELS; MAGNETIC-PROPERTIES; EXCITATIONS; ERPO4; HOVO4 AB We have investigated the Yb3+ crystal-field-level structure in YbVO4 using inelastic magnetic neutron-scattering measurements and crystal-field model calculations. We determined the temperature dependence of the a and c lattice parameters of the tetragonal unit cell by neutron diffraction and observed a minimum at ca. 120 K in the c lattice parameter. This anomaly in the thermal expansion is interpreted as arising from a coupling of the anisotropic low-lying crystal-field states of the Yb3+ ions and the crystal lattice at low temperatures. C1 COLORADO STATE UNIV,FT COLLINS,CO 80523. OAK RIDGE NATL LAB,OAK RIDGE,TN 37831. RP Nipko, JC (reprint author), ARGONNE NATL LAB,9700 S CASS AVE,ARGONNE,IL 60439, USA. RI Boatner, Lynn/I-6428-2013 OI Boatner, Lynn/0000-0002-0235-7594 NR 25 TC 11 Z9 11 U1 0 U2 3 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0925-8388 J9 J ALLOY COMPD JI J. Alloy. Compd. PD MAR 20 PY 1997 VL 250 IS 1-2 BP 569 EP 572 DI 10.1016/S0925-8388(96)02565-0 PG 4 WC Chemistry, Physical; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Chemistry; Materials Science; Metallurgy & Metallurgical Engineering GA XD794 UT WOS:A1997XD79400058 ER PT J AU Nipko, JC Loong, CK Loewenhaupt, M Reichardt, W Braden, M Boatner, LA AF Nipko, JC Loong, CK Loewenhaupt, M Reichardt, W Braden, M Boatner, LA TI Lattice dynamics of LuPO4 SO JOURNAL OF ALLOYS AND COMPOUNDS LA English DT Article; Proceedings Paper CT 21st Rare Earth Research Conference CY JUL 07-12, 1996 CL DULUTH, MN SP Rare Earth Res Conf Inc, Univ Minnesota, USR Optonix Inc, Amer Chem Soc, Petr Res Fund, Arris Int Corp, Baotou Steel & Rare Earth Co, US DE phonons; neutron spectroscopy; rare-earth orthophosphate ID ZIRCON AB Lutetium orthophosphate is an important nonmagnetic host material for rare-earth activated luminescence applications. We have measured the LuPO4 phonon density of states and dispersion curves along the [xi 00], [xi xi 0] and [00 xi] symmetry directions by neutron spectroscopy using polycrystalline and single crystal samples. A quantitative analysis of the neutron results was carried out using a lattice dynamic shell model. C1 COLORADO STATE UNIV, FT COLLINS, CO 80523 USA. TECH UNIV DRESDEN, D-8027 DRESDEN, GERMANY. FORSCHUNGSZENTRUM KARLSRUHE, INFP, D-76021 KARLSRUHE, GERMANY. OAK RIDGE NATL LAB, OAK RIDGE, TN 37831 USA. RP ARGONNE NATL LAB, 9700 S CASS AVE, ARGONNE, IL 60439 USA. RI Boatner, Lynn/I-6428-2013 OI Boatner, Lynn/0000-0002-0235-7594 NR 12 TC 6 Z9 6 U1 0 U2 1 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0925-8388 EI 1873-4669 J9 J ALLOY COMPD JI J. Alloy. Compd. PD MAR 20 PY 1997 VL 250 IS 1-2 BP 573 EP 576 DI 10.1016/S0925-8388(96)02566-2 PG 4 WC Chemistry, Physical; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Chemistry; Materials Science; Metallurgy & Metallurgical Engineering GA XD794 UT WOS:A1997XD79400059 ER PT J AU Rosenkranz, S Staub, U Furrer, A Osborn, R Lacorre, P Trounov, V AF Rosenkranz, S Staub, U Furrer, A Osborn, R Lacorre, P Trounov, V TI Intermultiplet crystal field transitions in EuNiO3 SO JOURNAL OF ALLOYS AND COMPOUNDS LA English DT Article; Proceedings Paper CT 21st Rare Earth Research Conference CY JUL 07-12, 1996 CL DULUTH, MN SP Rare Earth Res Conf Inc, Univ Minnesota, USR Optonix Inc, Amer Chem Soc, Petr Res Fund, Arris Int Corp, Baotou Steel & Rare Earth Co, US DE crystalline electric field; inelastic neutron scattering; spin-orbit interaction ID INSULATOR-TRANSITION; PRESSURE-DEPENDENCE; NEUTRON-DIFFRACTION; PRNIO3; 6-LESS-THAN-OR-EQUAL-TO-X-LESS-THAN-OR-EQUAL-TO-7; ERBA2CU3OX; NDNIO3 AB We determined the energy splitting of the F-7(1) multiplet of Eu3+ in EuNiO3 using inelastic neutron scattering. We were able to retrieve accurate values for the second order crystalline electric field parameters, which will allow a more reliable determination of the crystalline electric field potential in the RNiO3 (R = rare earth) series. This is essential for a possible observation of a charge transfer, which is proposed by one of the models describing the observed metal-to-insulator transition in these compounds. C1 PAUL SCHERRER INST,SWISS LIGHT SOURCE PROJECT,CH-5232 VILLIGEN,SWITZERLAND. ETH ZURICH,NEUTRON SCATTERING LAB,CH-5232 VILLIGEN,SWITZERLAND. ARGONNE NATL LAB,MAT RES DIV,ARGONNE,IL 60439. UNIV MAINE,LAB FLUORURES,F-72017 LE MANS,FRANCE. ST PETERSBURG NUCL PHYS INST,ST PETERSBURG 188350,RUSSIA. RI Osborn, Raymond/E-8676-2011; Rosenkranz, Stephan/E-4672-2011; Staub, Urs/C-4914-2015 OI Osborn, Raymond/0000-0001-9565-3140; Rosenkranz, Stephan/0000-0002-5659-0383; NR 14 TC 5 Z9 5 U1 0 U2 7 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0925-8388 J9 J ALLOY COMPD JI J. Alloy. Compd. PD MAR 20 PY 1997 VL 250 IS 1-2 BP 577 EP 580 DI 10.1016/S0925-8388(96)02567-4 PG 4 WC Chemistry, Physical; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Chemistry; Materials Science; Metallurgy & Metallurgical Engineering GA XD794 UT WOS:A1997XD79400060 ER PT J AU Staub, U Skanthakumar, S Soderholm, L Osborn, R AF Staub, U Skanthakumar, S Soderholm, L Osborn, R TI Magnetic properties of Pb2Sr2PrCu3O8 SO JOURNAL OF ALLOYS AND COMPOUNDS LA English DT Article; Proceedings Paper CT 21st Rare Earth Research Conference CY JUL 07-12, 1996 CL DULUTH, MN SP Rare Earth Res Conf Inc, Univ Minnesota, USR Optonix Inc, Amer Chem Soc, Petr Res Fund, Arris Int Corp, Baotou Steel & Rare Earth Co, US DE crystal and ligand fields; high-T-c superconductivity; inelastic neutron scattering; experimental x-ray diffraction and scattering techniques (XANES) ID NORMAL STATE PROPERTIES; CRYSTAL-FIELD; PRBA2CU3O7; 6-LESS-THAN-OR-EQUAL-TO-X-LESS-THAN-OR-EQUAL-TO-7; PR AB The magnetic properties of Pb2Sr2PrCu3O8 were determined using X-ray absorption, inelastic neutron spectroscopy and magnetic susceptibility measurements. X-ray absorption on the Pr L-3-edge strongly indicates a trivalent oxidation state. Inelastic neutron scattering results are modeled assuming a H-3(4) ground-state multiplet split by a crystalline electric field potential similar to PrBa2Cu3O7-delta. This potential correctly predicts the value of the Curie-Weiss moment, 2.72 mu B, obtained from magnetic susceptibility measurements, and so explains the reduction from the free-ion value. The very broad magnetic response found in the inelastic neutron scattering experiments indicates a strong interaction between the Pr 4f electrons and the CuO2 bands. C1 ARGONNE NATL LAB,DIV CHEM,ARGONNE,IL 60439. ARGONNE NATL LAB,MAT RES DIV,ARGONNE,IL 60439. RP Staub, U (reprint author), PAUL SCHERRER INST,SWISS LIGHT SOURCE PROJECT,CH-5232 VILLIGEN,SWITZERLAND. RI Osborn, Raymond/E-8676-2011; Staub, Urs/C-4914-2015 OI Osborn, Raymond/0000-0001-9565-3140; NR 14 TC 5 Z9 5 U1 0 U2 2 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0925-8388 J9 J ALLOY COMPD JI J. Alloy. Compd. PD MAR 20 PY 1997 VL 250 IS 1-2 BP 581 EP 584 DI 10.1016/S0925-8388(96)02568-6 PG 4 WC Chemistry, Physical; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Chemistry; Materials Science; Metallurgy & Metallurgical Engineering GA XD794 UT WOS:A1997XD79400061 ER PT J AU Canfield, PC Budko, SL Cho, BK Beyermann, WP Yatskar, A AF Canfield, PC Budko, SL Cho, BK Beyermann, WP Yatskar, A TI RNi2B2C magnetic superconductors: An update from the front SO JOURNAL OF ALLOYS AND COMPOUNDS LA English DT Article; Proceedings Paper CT 21st Rare Earth Research Conference CY JUL 07-12, 1996 CL DULUTH, MN SP Rare Earth Res Conf Inc, Univ Minnesota, USR Optonix Inc, Amer Chem Soc, Petr Res Fund, Arris Int Corp, Baotou Steel & Rare Earth Co, US DE RNi2B2C; magnetic superconductors ID BULK SUPERCONDUCTIVITY; TEMPERATURE AB A review of recent RNi2B2C research focusing on the variety of effects associated with the interaction between the conduction electrons giving rise to the superconductivity and the 4f-moments is presented. The effects of the 4f local moment on superconductivity are systematically examined via the study of thirty (R1-xR'(x))Ni2B2C pseudo-quaternary compounds. While de Gennes scaling may quantify the suppression of T-C for T-C>T-N, when T-CX(s)gamma gamma rare decay SO PHYSICS LETTERS B LA English DT Article ID QCD-CORRECTIONS; B->S-GAMMA DECAY; B->SG DECAYS; TOP-QUARK; BS->GAMMA-GAMMA; REGULARIZATION; SCHEMES; MODEL AB The rare decay B --> X(s) gamma gamma is studied in the standard model (SM) and in two different versions (Model I and Model II) of the two Higgs doublet model (2HDM). In the SM the branching ratio into hard photons is about 1 x 10(-7) and can be appreciably different in the 2HDM. We also introduce a forward-backward asymmetry which gives an additional handle to discriminate different models. (C) 1997 Elsevier Science B.V. C1 UNIV NAPLES,DIPARTIMENTO SCI FISICHE,I-80125 NAPLES,ITALY. IST NAZL FIS NUCL,SEZ NAPOLI,I-80125 NAPLES,ITALY. RP Reina, L (reprint author), BROOKHAVEN NATL LAB,DEPT PHYS,UPTON,NY 11973, USA. RI Ricciardi, Giulia/H-3649-2011 OI Ricciardi, Giulia/0000-0002-2352-9033 NR 31 TC 27 Z9 27 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0370-2693 J9 PHYS LETT B JI Phys. Lett. B PD MAR 20 PY 1997 VL 396 IS 1-4 BP 231 EP 237 PG 7 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA WQ988 UT WOS:A1997WQ98800034 ER PT J AU Acciarri, M Adriani, O AguilarBenitez, M Ahlen, S Alpat, B Alcaraz, J Alemanni, G Allaby, J Aloisio, A Alverson, G Alviggi, MG Ambrosi, G Anderhub, H Andreev, VP Angelescu, T Anselmo, F Antreasyan, D Arefiev, A Azemoon, T Aziz, T Bagnaia, P Baksay, L Ball, RC Banerjee, S Banicz, K Barillere, R Barone, L Bartalini, P Baschirotto, A Basile, M Battiston, R Bay, A Becattini, F Becker, U Behner, F Berdugo, J Berges, P Bertucci, B Betev, VL Bhattacharya, S Biasini, M Biland, A Bilei, GM Blaising, JJ Blyth, SC Bobbink, GJ Bock, R Bohm, A Borgia, B Boucham, A Bourilkov, D Bourquin, M Boutigny, D Branson, JG Brigljevic, V Brock, IC Buffini, A Buijs, A Burger, JD Burger, WJ Busenitz, J Cai, XD Campanelli, M Capell, M Romeo, GC Caria, M Carlino, G Cartacci, AM Casaus, J Castellini, G Cavallari, F Cavallo, N Cecchi, C Cerrada, M Cesaroni, F Chamizo, M Chan, A Chang, YH Chaturvedi, UK Chekanov, SV Chemarin, M Chen, G Chen, GM Chen, HF Chen, HS Chen, M Chiefari, G Chien, CY Choi, MT Cifarelli, L Cindolo, F Civinini, C Clare, I Clare, R Cohn, HO Coignet, G Colijn, AP Colino, N Commichau, V Costantini, S Cotorobai, F dellaCruz, B Csilling, A Dai, TS DAlessandro, R deAsmundis, R Degre, A Deiters, K Denes, P DeNotaristefani, F DiBitonto, D Diemoz, M vanDierendonck, D DiLodovico, F Dionisi, C Dittmar, M Dominguez, A Doria, A Dorne, I Dova, MT Drago, E Duchesneau, D Duinker, P Duran, I Dutta, S Easo, S Efremenko, Y ElMamouni, H Engler, A Eppling, FJ Erne, FC Ernenwein, JP Extermann, P Fabre, M Faccini, R Falciano, S Favara, A Fay, J Fedin, O Felcini, M Fenyi, B Ferguson, T Fernandez, D Ferroni, F Fesefeldt, H Fiandrini, E Field, JH Filthaut, F Fisher, PH Forconi, G Fredj, L Freudenreich, K Furetta, C Galaktionov, Y Ganguli, SN GarciaAbia, P Gau, SS Gentile, S Gerald, J Gheordanescu, N Giagu, S Goldfarb, S Goldstein, J Gong, ZF Gougas, A Gratta, G Gruenewald, MW Gupta, VK Gurtu, A Gutay, LJ Hartmann, B Hasan, A Hatzifotiadou, D Hebbeker, T Herve, A vanHoek, WC Hofer, H Hoorani, H Hou, SR Hu, G Innocente, V Janssen, H Jenkes, K Jin, BN Jones, LW deJong, P JosaMutuberria, I Kasser, A Khan, RA Kamrad, D Kamyshkov, Y Kapustinsky, JS Karyotakis, Y Kaur, M KienzleFocacci, MN Kim, D Kim, JK Kim, SC Kim, YG Kinnison, WW Kirkby, A Kirkby, D Kirkby, J Kiss, D Kittel, W Klimentov, A Konig, AC Korolko, I Koutsenko, V Kraemer, RW Krenz, W Kunin, A deGuevara, PLD Landi, G Lapoint, C LassilaPerini, K Laurikainen, P Lebeau, M Lebedev, A Lebrun, P Lecomte, P Lecoq, P LeCoultre, P Lee, JS Lee, KY Leggett, C LeGoff, JM Leiste, R Leonardi, E Levtchenko, P Li, C Lieb, E Lin, WT Linde, FL Lista, L Liu, ZA Lohmann, W Longo, E Lu, W Lu, YS Lubelsmeyer, K Luci, C Luckey, D Luminari, L Lustermann, W Ma, WG Maity, M Majumder, G Malgeri, L Malinin, A Manna, C Mangeol, D Mangla, S Marchesini, P Marin, A Martin, JP Marzano, F Massaro, GGG McNally, D Mele, S Merola, L Meschini, M Metzger, WJ vonderMey, M Mi, Y Mihul, A vanMil, AJW Mirabelli, G Mnich, J Molnar, P Monteleoni, B Moore, R Morganti, S Moulik, T Mont, R Muller, S Muheim, F Muijs, AJM Nagy, E Nahn, S Napolitano, M NessiTedaldi, F Newman, H Niessen, T Nippe, A Nisati, A Nowak, H Opitz, H Organtini, G Ostonen, R Pakhlov, P Pandoulas, D Paoletti, S Paolucci, P Park, HK Pascale, G Passaleva, G Patricelli, S Paul, T Pauluzzi, M Paus, C Pauss, F Peach, D Pei, YJ Pensotti, S PerretGallix, D Petersen, B Petrak, S Pevsner, A Piccolo, D Pieri, M Pinto, JC Piroue, PA Pistolesi, E Plyaskin, V Pohl, M Pojidaev, V Postema, H Produit, N Prokofiev, D RahalCallot, G Rancoita, PG Rattaggi, M Raven, G Razis, P Read, K Ren, D Rescigno, M Reucroft, S vanRhee, T Riemann, S Riles, K Rind, O Ro, S Robohm, A Rodin, J Rodriguez, FJ Roe, BP Romero, L RosierLees, S Rosselet, P vanRossum, W Roth, S Rubio, JA Rykaczewski, H Salicio, J Sanchez, E Sanders, MP Santocchia, A Sarakinos, ME Sarkar, S Sassowsky, M Sauvage, G Schafer, C Schegelsky, V SchmidtKaerst, S Schmitz, D Schmitz, P Schneegans, M Scholz, N Schopper, H Schotanus, DJ Schwenke, J Schwering, G Sciacca, C Sciarrino, D Sens, JC Servoli, L Shevchenko, S Shivarov, N Shoutko, V Shukla, J Shumilov, E Shvorob, A Siedenburg, T Son, D Sopczak, A Soulimov, V Smith, B Spillantini, P Steuer, M Stickland, DP Stone, H Stoyanov, B Straessner, A Strauch, K Sudhakar, K Sultanov, G Sun, LZ Susinno, GF Suter, H Swain, JD Tang, XW Tauscher, L Taylor, L Ting, SCC Ting, SM Tonutti, M Tonwar, SC Toth, J Tully, C Tuchscherer, H Tung, KL Uchida, Y Ulbricht, J Uwer, U Valente, E VandeWalle, RT Vesztergombi, G Vetlitsky, I Viertel, G Vivargent, M Volkert, R Vogel, H Vogt, H Vorobiev, I Vorobyov, AA Vorvolakos, A Wadhwa, M Wallraff, W Wang, JC Wang, XL Wang, ZM Weber, A Wittgenstein, F Wu, SX Wynhoff, S Xu, J Xu, ZZ Yang, BZ Yang, CG Yao, XY Ye, JB Yeh, SC You, JM Zalite, A Zalite, Y Zemp, P Zeng, Y Zhang, Z Zhang, ZP Zhou, B Zhou, Y Zhu, GY Zhu, RY Zichichi, A Ziegler, F AF Acciarri, M Adriani, O AguilarBenitez, M Ahlen, S Alpat, B Alcaraz, J Alemanni, G Allaby, J Aloisio, A Alverson, G Alviggi, MG Ambrosi, G Anderhub, H Andreev, VP Angelescu, T Anselmo, F Antreasyan, D Arefiev, A Azemoon, T Aziz, T Bagnaia, P Baksay, L Ball, RC Banerjee, S Banicz, K Barillere, R Barone, L Bartalini, P Baschirotto, A Basile, M Battiston, R Bay, A Becattini, F Becker, U Behner, F Berdugo, J Berges, P Bertucci, B Betev, VL Bhattacharya, S Biasini, M Biland, A Bilei, GM Blaising, JJ Blyth, SC Bobbink, GJ Bock, R Bohm, A Borgia, B Boucham, A Bourilkov, D Bourquin, M Boutigny, D Branson, JG Brigljevic, V Brock, IC Buffini, A Buijs, A Burger, JD Burger, WJ Busenitz, J Cai, XD Campanelli, M Capell, M Romeo, GC Caria, M Carlino, G Cartacci, AM Casaus, J Castellini, G Cavallari, F Cavallo, N Cecchi, C Cerrada, M Cesaroni, F Chamizo, M Chan, A Chang, YH Chaturvedi, UK Chekanov, SV Chemarin, M Chen, G Chen, GM Chen, HF Chen, HS Chen, M Chiefari, G Chien, CY Choi, MT Cifarelli, L Cindolo, F Civinini, C Clare, I Clare, R Cohn, HO Coignet, G Colijn, AP Colino, N Commichau, V Costantini, S Cotorobai, F dellaCruz, B Csilling, A Dai, TS DAlessandro, R deAsmundis, R Degre, A Deiters, K Denes, P DeNotaristefani, F DiBitonto, D Diemoz, M vanDierendonck, D DiLodovico, F Dionisi, C Dittmar, M Dominguez, A Doria, A Dorne, I Dova, MT Drago, E Duchesneau, D Duinker, P Duran, I Dutta, S Easo, S Efremenko, Y ElMamouni, H Engler, A Eppling, FJ Erne, FC Ernenwein, JP Extermann, P Fabre, M Faccini, R Falciano, S Favara, A Fay, J Fedin, O Felcini, M Fenyi, B Ferguson, T Fernandez, D Ferroni, F Fesefeldt, H Fiandrini, E Field, JH Filthaut, F Fisher, PH Forconi, G Fredj, L Freudenreich, K Furetta, C Galaktionov, Y Ganguli, SN GarciaAbia, P Gau, SS Gentile, S Gerald, J Gheordanescu, N Giagu, S Goldfarb, S Goldstein, J Gong, ZF Gougas, A Gratta, G Gruenewald, MW Gupta, VK Gurtu, A Gutay, LJ Hartmann, B Hasan, A Hatzifotiadou, D Hebbeker, T Herve, A vanHoek, WC Hofer, H Hoorani, H Hou, SR Hu, G Innocente, V Janssen, H Jenkes, K Jin, BN Jones, LW deJong, P JosaMutuberria, I Kasser, A Khan, RA Kamrad, D Kamyshkov, Y Kapustinsky, JS Karyotakis, Y Kaur, M KienzleFocacci, MN Kim, D Kim, JK Kim, SC Kim, YG Kinnison, WW Kirkby, A Kirkby, D Kirkby, J Kiss, D Kittel, W Klimentov, A Konig, AC Korolko, I Koutsenko, V Kraemer, RW Krenz, W Kunin, A deGuevara, PLD Landi, G Lapoint, C LassilaPerini, K Laurikainen, P Lebeau, M Lebedev, A Lebrun, P Lecomte, P Lecoq, P LeCoultre, P Lee, JS Lee, KY Leggett, C LeGoff, JM Leiste, R Leonardi, E Levtchenko, P Li, C Lieb, E Lin, WT Linde, FL Lista, L Liu, ZA Lohmann, W Longo, E Lu, W Lu, YS Lubelsmeyer, K Luci, C Luckey, D Luminari, L Lustermann, W Ma, WG Maity, M Majumder, G Malgeri, L Malinin, A Manna, C Mangeol, D Mangla, S Marchesini, P Marin, A Martin, JP Marzano, F Massaro, GGG McNally, D Mele, S Merola, L Meschini, M Metzger, WJ vonderMey, M Mi, Y Mihul, A vanMil, AJW Mirabelli, G Mnich, J Molnar, P Monteleoni, B Moore, R Morganti, S Moulik, T Mont, R Muller, S Muheim, F Muijs, AJM Nagy, E Nahn, S Napolitano, M NessiTedaldi, F Newman, H Niessen, T Nippe, A Nisati, A Nowak, H Opitz, H Organtini, G Ostonen, R Pakhlov, P Pandoulas, D Paoletti, S Paolucci, P Park, HK Pascale, G Passaleva, G Patricelli, S Paul, T Pauluzzi, M Paus, C Pauss, F Peach, D Pei, YJ Pensotti, S PerretGallix, D Petersen, B Petrak, S Pevsner, A Piccolo, D Pieri, M Pinto, JC Piroue, PA Pistolesi, E Plyaskin, V Pohl, M Pojidaev, V Postema, H Produit, N Prokofiev, D RahalCallot, G Rancoita, PG Rattaggi, M Raven, G Razis, P Read, K Ren, D Rescigno, M Reucroft, S vanRhee, T Riemann, S Riles, K Rind, O Ro, S Robohm, A Rodin, J Rodriguez, FJ Roe, BP Romero, L RosierLees, S Rosselet, P vanRossum, W Roth, S Rubio, JA Rykaczewski, H Salicio, J Sanchez, E Sanders, MP Santocchia, A Sarakinos, ME Sarkar, S Sassowsky, M Sauvage, G Schafer, C Schegelsky, V SchmidtKaerst, S Schmitz, D Schmitz, P Schneegans, M Scholz, N Schopper, H Schotanus, DJ Schwenke, J Schwering, G Sciacca, C Sciarrino, D Sens, JC Servoli, L Shevchenko, S Shivarov, N Shoutko, V Shukla, J Shumilov, E Shvorob, A Siedenburg, T Son, D Sopczak, A Soulimov, V Smith, B Spillantini, P Steuer, M Stickland, DP Stone, H Stoyanov, B Straessner, A Strauch, K Sudhakar, K Sultanov, G Sun, LZ Susinno, GF Suter, H Swain, JD Tang, XW Tauscher, L Taylor, L Ting, SCC Ting, SM Tonutti, M Tonwar, SC Toth, J Tully, C Tuchscherer, H Tung, KL Uchida, Y Ulbricht, J Uwer, U Valente, E VandeWalle, RT Vesztergombi, G Vetlitsky, I Viertel, G Vivargent, M Volkert, R Vogel, H Vogt, H Vorobiev, I Vorobyov, AA Vorvolakos, A Wadhwa, M Wallraff, W Wang, JC Wang, XL Wang, ZM Weber, A Wittgenstein, F Wu, SX Wynhoff, S Xu, J Xu, ZZ Yang, BZ Yang, CG Yao, XY Ye, JB Yeh, SC You, JM Zalite, A Zalite, Y Zemp, P Zeng, Y Zhang, Z Zhang, ZP Zhou, B Zhou, Y Zhu, GY Zhu, RY Zichichi, A Ziegler, F TI Measurement of D-s(-)->tau(-)(nu)over-bar(tau) and a new limit for B-->tau(-)(nu)over-bar(tau center dot) SO PHYSICS LETTERS B LA English DT Article ID DECAY; CONSTRUCTION; DETECTOR AB Using a data sample of 1475000 Z --> q (q) over bar(gamma) events collected during 1993 with the L3 detector at LEP, we have studied the purely leptonic decays of heavy flavour mesons, D-s(-) --> tau(-)(v) over bar(tau) and B- --> tau(-)(v) over bar(tau). A signal is observed in the invariant mass distribution M(gamma D-s(-)) corresponding to the decay sequence D-s(*-) --> gamma D-s(-), D-s(-) --> tau(-)(v) over bar(tau), tau(-)(v) over bar(tau), tau(-) --> l(-)(v) over bar(l)v(tau). The branching fraction for D-s(-) tau(-) (v) over bar(tau) decays is measured to be B(D-s(-) --> tau(-)(v) over bar(tau)) = 0.074 +/- 0.028(stat) +/- 0.016(syst) +/- 0.018(norm). No signal of B- --> tau-(v) over bar(tau) decays is observed in the data, corresponding to an upper limit on the branching fraction B(B- --> tau(-)(v) over bar(tau)) < 5.7 x 10(-4) at 90% CL. (C) 1997 Elsevier Science B.V. C1 RHEIN WESTFAL TH AACHEN, INST PHYS 1, D-52056 AACHEN, GERMANY. RHEIN WESTFAL TH AACHEN, INST PHYS 2, D-52056 AACHEN, GERMANY. UNIV AMSTERDAM, NL-1009 DB AMSTERDAM, NETHERLANDS. NIKHEF H, NATL INST HIGH ENERGY PHYS, NL-1009 DB AMSTERDAM, NETHERLANDS. UNIV MICHIGAN, ANN ARBOR, MI 48109 USA. LAB ANNECY LE VIEUX PHYS PARTICULES, IN2P3, CNRS, F-74941 ANNECY LE VIEUX, FRANCE. JOHNS HOPKINS UNIV, BALTIMORE, MD 21218 USA. UNIV BASEL, INST PHYS, CH-4056 BASEL, SWITZERLAND. INST HIGH ENERGY PHYS, BEIJING 100039, PEOPLES R CHINA. HUMBOLDT UNIV BERLIN, D-10099 BERLIN, GERMANY. IST NAZL FIS NUCL, I-40126 BOLOGNA, ITALY. TATA INST FUNDAMENTAL RES, BOMBAY 400005, MAHARASHTRA, INDIA. BOSTON UNIV, BOSTON, MA 02215 USA. NORTHEASTERN UNIV, BOSTON, MA 02115 USA. UNIV BUCHAREST, R-76900 BUCHAREST, ROMANIA. INST ATOM PHYS, R-76900 BUCHAREST, ROMANIA. HUNGARIAN ACAD SCI, CENT RES INST PHYS, H-1525 BUDAPEST 114, HUNGARY. HARVARD UNIV, CAMBRIDGE, MA 02139 USA. MIT, CAMBRIDGE, MA 02139 USA. UNIV FLORENCE, I-50125 FLORENCE, ITALY. IST NAZL FIS NUCL, 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. UNIV SCI & TECHNOL CHINA, USTC, HEFEI 230029, ANHUI, PEOPLES R CHINA. SEFT, RES INST HIGH ENERGY PHYS, SF-00014 HELSINKI, FINLAND. UNIV LAUSANNE, CH-1015 LAUSANNE, SWITZERLAND. UNIV LECCE, I-73100 LECCE, ITALY. IST NAZL FIS NUCL, I-73100 LECCE, ITALY. LOS ALAMOS NATL LAB, LOS ALAMOS, NM 87544 USA. UNIV LYON 1, CNRS, IN2P3, INST PHYS NUCL, F-69622 VILLEURBANNE, FRANCE. CIEMAT, E-28040 MADRID, SPAIN. IST NAZL FIS NUCL, I-20133 MILAN, ITALY. ITEP, MOSCOW, RUSSIA. UNIV NAPLES, I-80125 NAPLES, ITALY. IST NAZL FIS NUCL, I-80125 NAPLES, ITALY. UNIV CYPRUS, DEPT NAT SCI, NICOSIA, CYPRUS. CATHOLIC UNIV NIJMEGEN, NL-6525 ED NIJMEGEN, NETHERLANDS. NATL INST NUCL PHYS & HIGH ENERGY PHYS, NL-6525 ED NIJMEGEN, NETHERLANDS. OAK RIDGE NATL LAB, OAK RIDGE, TN 37831 USA. CALTECH, PASADENA, CA 91125 USA. IST NAZL FIS NUCL, I-06100 PERUGIA, ITALY. UNIV PERUGIA, I-06100 PERUGIA, ITALY. CARNEGIE MELLON UNIV, PITTSBURGH, PA 15213 USA. PRINCETON UNIV, PRINCETON, NJ 08544 USA. IST NAZL FIS NUCL, I-00185 ROME, ITALY. UNIV ROMA LA SAPIENZA, I-00185 ROME, ITALY. INST PHYS NUCL, ST PETERSBURG, RUSSIA. UNIV SALERNO, I-84100 SALERNO, ITALY. IST NAZL FIS NUCL, I-84100 SALERNO, ITALY. UNIV CALIF SAN DIEGO, LA JOLLA, CA 92093 USA. UNIV SANTIAGO DE COMPOSTELA, DEPT FIS PARTICULAS ELEMENTALES, E-15706 SANTIAGO DE COMPOSTELA, SPAIN. BULGARIAN ACAD SCI, CENT LAB MECHATR & INSTRUMENTAT, BU-1113 SOFIA, BULGARIA. KOREA ADV INST SCI & TECHNOL, CTR HIGH ENERGY PHYS, TAEJON 305701, SOUTH KOREA. UNIV ALABAMA, TUSCALOOSA, AL 35486 USA. UNIV UTRECHT, NL-3584 CB UTRECHT, NETHERLANDS. NIKHEF H, NL-3584 CB UTRECHT, NETHERLANDS. PURDUE UNIV, W LAFAYETTE, IN 47907 USA. PAUL SCHERRER INST, CH-5232 VILLIGEN, SWITZERLAND. DESY, INST HOCHENERGIEPHYS, D-15738 ZEUTHEN, GERMANY. ETH ZURICH, CH-8093 ZURICH, SWITZERLAND. UNIV HAMBURG, D-22761 HAMBURG, GERMANY. RP IST NAZL FIS NUCL, VIA CELORIA 16, I-20133 MILAN, ITALY. RI Fiandrini, Emanuele/C-4549-2008; D'Alessandro, Raffaello/F-5897-2015; Duran, Ignacio/H-7254-2015; rodriguez calonge, francisco javier/H-9682-2015; Lista, Luca/C-5719-2008; Kirkby, Jasper/A-4973-2012; Servoli, Leonello/E-6766-2012; alpat, ali behcet/G-6290-2013; bertucci, bruna/J-5237-2012; Cavallo, Nicola/F-8913-2012; Cerrada, Marcos/J-6934-2014; Josa, Isabel/K-5184-2014; Berdugo, Javier/A-2858-2015; Sanchez, Eusebio/H-5228-2015; Rancoita, Pier Giorgio/J-9896-2015; Hoorani, Hafeez/D-1791-2013; Pakhlov, Pavel/K-2158-2013; Fedin, Oleg/H-6753-2016; Roth, Stefan/J-2757-2016; Kamyshkov, Yuri/J-7999-2016 OI D'Alessandro, Raffaello/0000-0001-7997-0306; Kirkby, Jasper/0000-0003-2341-9069; Servoli, Leonello/0000-0003-1725-9185; alpat, ali behcet/0000-0002-0116-1506; Cerrada, Marcos/0000-0003-0112-1691; Berdugo, Javier/0000-0002-7911-8532; Sanchez, Eusebio/0000-0002-9646-8198; Rancoita, Pier Giorgio/0000-0002-1990-4283; Pakhlov, Pavel/0000-0001-7426-4824; Roth, Stefan/0000-0003-3616-2223; Kamyshkov, Yuri/0000-0002-3789-7152 NR 33 TC 61 Z9 61 U1 1 U2 6 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 MAR 20 PY 1997 VL 396 IS 1-4 BP 327 EP 337 PG 11 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA WQ988 UT WOS:A1997WQ98800046 ER PT J AU Adams, D Adeva, B Akdogan, T Arik, E Arvidson, A Badelek, B Ballintijn, MK Bardin, D Bardin, G Baum, G Berglund, P Betev, L Bird, IG Birsa, R Bjorkholm, P Bonner, BE deBotton, N Boutemeur, M Bradamante, F Bravar, A Bressan, A Bultmann, S Burtin, E Cavata, C Crabb, D Cranshaw, J Cuhadar, T DallaTorre, S vanDantzig, R Derro, B Deshpande, A Dhawan, S Dulya, C Dyring, A Eichblatt, S Faivre, JC Fasching, D Feinstein, F Fernandez, C Frois, B Gallas, A Garzon, JA Gaussiran, T Giorgi, M vonGoeler, E Gomez, F Gracia, G deGroot, N GrossePerdekamp, M vonHarrach, D Hasegawa, T Hautle, P Hayashi, N Heusch, CA Horikawa, N Hughes, VW Igo, G Ishimoto, S Iwata, T Kabuss, EM Kageya, T Kalinovskaya, L Karev, A Kessler, HJ Ketel, TJ Kiryluk, J Kishi, A Kisselev, Y Klostermann, L Kramer, D Krivokhijine, V Kroger, W Kukhtin, V Kurek, K Kyynarainen, J Lamanna, M Landgraf, U LeGoff, JM Lehar, F deLesquen, A Lichtenstadt, J Lindqvist, T Litmaath, M Lowe, M Magnon, A Mallot, GK Marie, F Martin, A Martino, J Matsuda, T Mayes, B McCarthy, JS Medved, K vanMiddelkoop, G Miller, D Mori, K Moromisato, J Nagaitsev, A Nassalski, J Naumann, L Niinikoski, TO Oberski, JEJ Ogawa, A Ozben, C Parks, DP PerrotKunne, F Peshekhonov, D Piegaia, R Pinsky, L Platchkov, S Plo, M Polec, J Pose, D Postman, H Pretz, J Puntaferro, R Pussieux, T Pyrlik, J Radel, G Rijllart, A Roberts, JB Rock, S Rodriguez, M Rondio, E Rosado, A Sabo, I Saborido, J Sandacz, A Savin, I Schiavon, P Schuller, KP Seitz, R Semertzidis, Y Sever, F Shanahan, P Sichtermann, EP Simeoni, F Smirnov, GI Staude, A Steinmetz, A Stiegler, U Stuhrmann, H Szleper, M Teichert, KM Tessarotto, F Tlaczala, W Trentalange, S Tripet, A Unel, G Velasco, M Vogt, J Voss, R Weinstein, R Whitten, C Windmolders, R Willumeit, R Wislicki, W Witzmann, A Yanez, A Ylostalo, Y Zanetti, AM Zaremba, K Zhao, J AF Adams, D Adeva, B Akdogan, T Arik, E Arvidson, A Badelek, B Ballintijn, MK Bardin, D Bardin, G Baum, G Berglund, P Betev, L Bird, IG Birsa, R Bjorkholm, P Bonner, BE deBotton, N Boutemeur, M Bradamante, F Bravar, A Bressan, A Bultmann, S Burtin, E Cavata, C Crabb, D Cranshaw, J Cuhadar, T DallaTorre, S vanDantzig, R Derro, B Deshpande, A Dhawan, S Dulya, C Dyring, A Eichblatt, S Faivre, JC Fasching, D Feinstein, F Fernandez, C Frois, B Gallas, A Garzon, JA Gaussiran, T Giorgi, M vonGoeler, E Gomez, F Gracia, G deGroot, N GrossePerdekamp, M vonHarrach, D Hasegawa, T Hautle, P Hayashi, N Heusch, CA Horikawa, N Hughes, VW Igo, G Ishimoto, S Iwata, T Kabuss, EM Kageya, T Kalinovskaya, L Karev, A Kessler, HJ Ketel, TJ Kiryluk, J Kishi, A Kisselev, Y Klostermann, L Kramer, D Krivokhijine, V Kroger, W Kukhtin, V Kurek, K Kyynarainen, J Lamanna, M Landgraf, U LeGoff, JM Lehar, F deLesquen, A Lichtenstadt, J Lindqvist, T Litmaath, M Lowe, M Magnon, A Mallot, GK Marie, F Martin, A Martino, J Matsuda, T Mayes, B McCarthy, JS Medved, K vanMiddelkoop, G Miller, D Mori, K Moromisato, J Nagaitsev, A Nassalski, J Naumann, L Niinikoski, TO Oberski, JEJ Ogawa, A Ozben, C Parks, DP PerrotKunne, F Peshekhonov, D Piegaia, R Pinsky, L Platchkov, S Plo, M Polec, J Pose, D Postman, H Pretz, J Puntaferro, R Pussieux, T Pyrlik, J Radel, G Rijllart, A Roberts, JB Rock, S Rodriguez, M Rondio, E Rosado, A Sabo, I Saborido, J Sandacz, A Savin, I Schiavon, P Schuller, KP Seitz, R Semertzidis, Y Sever, F Shanahan, P Sichtermann, EP Simeoni, F Smirnov, GI Staude, A Steinmetz, A Stiegler, U Stuhrmann, H Szleper, M Teichert, KM Tessarotto, F Tlaczala, W Trentalange, S Tripet, A Unel, G Velasco, M Vogt, J Voss, R Weinstein, R Whitten, C Windmolders, R Willumeit, R Wislicki, W Witzmann, A Yanez, A Ylostalo, Y Zanetti, AM Zaremba, K Zhao, J TI The spin-dependent structure function g(1)(x) of the deuteron from polarized deep-inelastic muon scattering SO PHYSICS LETTERS B LA English DT Article ID SUM-RULE; PRECISION-MEASUREMENT; PROTON; ELECTROPRODUCTION; DISTRIBUTIONS; ASYMMETRY; LEPTONS AB We present a new measurement of the spin-dependent structure function g(1)(d) of the deuteron from deep inelastic scattering of 190 GeV polarized muons on polarized deuterons. The results are combined with our previous measurements of g(1)(d). A perturbative QCD evolution in next-to-leading order is used to compute g(1)(d)(x) at a constant Q(2). At Q(2) = 10GeV(2), we obtain a first moment r(1)(d) = integral(0)(1)g(1)(d)x=0.041 +/- 0.008, a flavour-singlet axial charge of the nucleon a(0)=0.30 +/- 0.08, and an axial charge of the strange quark a(s)=-0.09 +/- 0.03. Using our earlier determination of Gamma(1)(p), we obtain Gamma(1)(p) - Gamma(1)(n)=0.183 +/- 0.035 at Q(2) = 10GeV(2). This result is in agreement with the Bjorken sum rule which predicts Gamma(1)(p) - Gamma(1)(n)=0.186 +/- 0.002 at the same Q(2). (C) 1997 Published by Elsevier Science B.V. C1 UNIV BIELEFELD,DEPT PHYS,D-33501 BIELEFELD,GERMANY. BOGAZICI UNIV,ISTANBUL,TURKEY. ISTANBUL TECH UNIV,TR-80626 ISTANBUL,TURKEY. UNIV CALIF LOS ANGELES,DEPT PHYS,LOS ANGELES,CA 90024. CERN,CH-1211 GENEVA 23,SWITZERLAND. UNIV FREIBURG,DEPT PHYS,D-79104 FREIBURG,GERMANY. GKSS,D-21494 GEESTHACHT,GERMANY. UNIV TECHNOL,LOW TEMP LAB,ESPOO 02150,FINLAND. INST PARTICLE PHYS TECHNOL,ESPOO 02150,FINLAND. INST BEAM PARTICLE DYNAM,HOUSTON,TX 77204. UNIV HOUSTON,DEPT PHYS,HOUSTON,TX 77204. JINR,LAB PARTICLE PHYS,RU-141980 DUBNA,RUSSIA. UNIV MAINZ,INST PHYS NUCL,D-55099 MAINZ,GERMANY. UNIV MONS,FAC SCI,B-7000 MONS,BELGIUM. UNIV MUNICH,DEPT PHYS,D-80799 MUNICH,GERMANY. NAGOYA UNIV,CIRSE,CHIKUSA KU,NAGOYA,AICHI 464,JAPAN. NAGOYA UNIV,DEPT PHYS,CHIKUSA KU,NAGOYA,AICHI 464,JAPAN. NAGOYA UNIV,COLL MED TECHNOL,HIGASHI KU,NAGOYA,AICHI 461,JAPAN. DELFT UNIV TECHNOL,NIKHEF H,FOM,NL-1009 AJ AMSTERDAM,NETHERLANDS. FREE UNIV AMSTERDAM,NL-1009 AJ AMSTERDAM,NETHERLANDS. NORTHEASTERN UNIV,DEPT PHYS,BOSTON,MA 02115. NORTHWESTERN UNIV,DEPT PHYS,EVANSTON,IL 60208. RICE UNIV,BONNER LAB,HOUSTON,TX 77251. CEA SACLAY,DAPNIA,F-91191 GIF SUR YVETTE,FRANCE. UNIV SANTIAGO DE COMPOSTELA,INST FIS ALTAS ENERGIAS,SANTIAGO COMPOSTE 15706,SPAIN. TEL AVIV UNIV,SCH PHYS,IL-69978 TEL AVIV,ISRAEL. UNIV TRIESTE,DEPT PHYS,I-34127 TRIESTE,ITALY. IST NAZL FIS NUCL,I-34127 TRIESTE,ITALY. UPPSALA UNIV,DEPT RADIAT SCI,S-75121 UPPSALA,SWEDEN. UNIV VIRGINIA,DEPT PHYS,CHARLOTTESVILLE,VA 22901. SOLTAN INST NUCL STUDIES,PL-00681 WARSAW,POLAND. UNIV WARSAW,PL-00681 WARSAW,POLAND. WARSAW UNIV TECHNOL,PL-00681 WARSAW,POLAND. YALE UNIV,DEPT PHYS,NEW HAVEN,CT 06511. INST HOCHENERGIEPHYS,D-15738 ZEUTHEN,GERMANY. MIYAZAKI UNIV,FAC ENGN,MIYAZAKI 88921,JAPAN. PAUL SCHERRER INST,CH-5232 VILLIGEN,SWITZERLAND. UNIV CALIF SANTA CRUZ,INST PARTICLE PHYS,SANTA CRUZ,CA 95064. KEK,TSUKUBA,IBARAKI 305,JAPAN. UNIV BUENOS AIRES,DEPT PHYS,RA-1428 BUENOS AIRES,DF,ARGENTINA. AMERICAN UNIV,WASHINGTON,DC 20016. BROOKHAVEN NATL LAB,UPTON,NY 11973. RP Adams, D (reprint author), RICE UNIV,BONNER LAB,HOUSTON,TX 77251, USA. RI CAVATA, Christian/P-6496-2015; de Groot, Nicolo/A-2675-2009; Hautle, Patrick/C-1044-2012; Martin, Anna/I-9381-2012; Zhao, Jinkui/B-7872-2013; Le Goff, Jean-Marc/E-7629-2013; Semertzidis, Yannis K./N-1002-2013; Gallas Torreira, Abraham Antonio/K-6508-2014; Yanez, Armando/L-2957-2014; Gomez, Faustino/L-7288-2014; Plo Casasus, Maximo/M-1445-2014; Adeva, Bernardo /L-1378-2014; Saborido Silva, Juan Jose/K-1775-2014 OI Hautle, Patrick/0000-0002-0502-8278; Martin, Anna/0000-0002-1333-0143; Zhao, Jinkui/0000-0002-7756-1952; Gallas Torreira, Abraham Antonio/0000-0002-2745-7954; Yanez, Armando/0000-0003-4626-7993; Gomez, Faustino/0000-0002-6147-8425; Plo Casasus, Maximo/0000-0002-2289-918X; Adeva, Bernardo /0000-0001-9756-3712; Saborido Silva, Juan Jose/0000-0002-6270-130X NR 51 TC 132 Z9 132 U1 0 U2 4 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0370-2693 J9 PHYS LETT B JI Phys. Lett. B PD MAR 20 PY 1997 VL 396 IS 1-4 BP 338 EP 348 PG 11 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA WQ988 UT WOS:A1997WQ98800047 ER PT J AU Haneman, D AF Haneman, D TI Nitrogen adsorption and native contamination on Fe(211) surfaces SO SURFACE SCIENCE LA English DT Article DE adsorption; auger electron spectroscopy; carbon; chlorine; diffusion; iron; low energy electron diffraction (LEED); low index single crystal surfaces; nitrogen; oxygen; solid-gas interfaces; sulfur; surface structure ID IRON SURFACES; FE(111); FE(100); N2; CHEMISORPTION; DISSOCIATION; PRECURSOR; AMMONIA AB Nitrogen adsorption has been studied on clean Fe(211) surfaces. Negligible adsorption occurred at low or room temperature. However, a surface with particular contamination showed appreciable adsorption. Heating a clean surface in nitrogen resulted in a small surface N concentration with a (2 x 5) structure, but since the same occurred after heating a nitrogen-rich surface region in a high vacuum, it indicates that internal N diffuses to the surface at heating temperatures as low as 580 K. Since there is no clear evidence that any appreciable adsorption occurs from 80 to 580 K, speculation about a special site existing for initial adsorption, such as the C7 site, is not supported. Internal chlorine was detected on the surface after heavy exposures of nitrogen, hydrogen or oxygen, indicating that complex interactions occur with gases in the sub-surface region. Because used catalysts in ammonia catalysis show the presence of C and O, the structures on Fe(211) formed with internal contaminants S, C and external O were studied. Various ordered structures were found to form at fractional monolayer concentrations, and cannot be excluded from being involved in the catalysis process. (C) 1997 Elsevier Science B.V. C1 LAWRENCE BERKELEY LAB,BERKELEY,CA 94720. NR 24 TC 7 Z9 7 U1 0 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 MAR 20 PY 1997 VL 375 IS 1 BP 71 EP 80 DI 10.1016/S0039-6028(96)01262-9 PG 10 WC Chemistry, Physical; Physics, Condensed Matter SC Chemistry; Physics GA WZ271 UT WOS:A1997WZ27100010 ER PT J AU Pan, JJ Charych, D AF Pan, JJ Charych, D TI Molecular recognition and colorimetric detection of cholera toxin by poly(diacetylene) liposomes incorporating G(m1) ganglioside SO LANGMUIR LA English DT Letter ID ACID MONOLAYERS; MEMBRANES; POLYDIACETYLENES; POLYMERIZATION AB Molecular recognition sites on cell membranes serve as the main communication channels between the inside of a cell and its surroundings. Upon receptor binding, celular messages such as ion channel opening or activation of enzymes are triggered. In this report, we demonstrate that artificial cell membranes made from conjugated lipid polymers (poly(diacetylene)) can, on a simple level, mimic membrane processes of molecular recognition and signal transduction. The ganglioside GM1 was incorporated into poly(diacetylene) liposomes. Molecular recognition of cholera toxin at the interface of the liposome resulted in a change of the membrane color due to conformational changes in the conjugated (ene-yne) polymer backbone. The ''colored liposomes'' might be used as simple colorimetric sensors for drug screening or as new tools to study membrane-membrane or membrane-receptor interactions. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV MAT SCI,CTR ADV MAT,BERKELEY,CA 94720. NR 20 TC 156 Z9 158 U1 4 U2 16 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0743-7463 J9 LANGMUIR JI Langmuir PD MAR 19 PY 1997 VL 13 IS 6 BP 1365 EP 1367 DI 10.1021/la9602675 PG 3 WC Chemistry, Multidisciplinary; Chemistry, Physical; Materials Science, Multidisciplinary SC Chemistry; Materials Science GA WP366 UT WOS:A1997WP36600002 ER PT J AU Oprea, TI Hummer, G Garcia, AE AF Oprea, TI Hummer, G Garcia, AE TI Identification of a functional water channel in cytochrome P450 enzymes SO PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA LA English DT Article DE aromatase; potentials of mean force; protein cavities; protein dynamics; protein hydration ID CRYSTAL-STRUCTURE; ACTIVE-SITE; MOLECULAR RECOGNITION; REDOX EQUILIBRIA; SALT BRIDGE; DATA-BANK; SPIN; HYDROXYLATION; RESOLUTION; PROTEINS AB Cytochrome P450 enzymes are monooxygenases that contain a functional heme b group linked to a conserved cysteine with a thiolate bond, In the native state, the central iron atom is hexacoordinated with a covalently bound water molecule, The exclusion of solvent molecules from the active site is essential for efficient enzymatic function, Upon substrate binding, water has to be displaced from the active site to prevent electron uncoupling that results in hydrogen peroxide or water, In contrast to typical hemoproteins, the protein surface is not directly accessible from the heme of cytochromes P450, We postulate a two-state model in which a conserved arginine, stabilizing the heme propionate in all known cytochrome P450 crystal structures, changes from the initial, stable side-chain conformation to another rotamer (metastable), In this new state, a functional water channel (aqueduct) is formed from the active site to a water cluster located on the thiolate side of the heme, close to the protein surface, This water cluster communicates with the surface in the closed state and is partly replaced by the flipping arginine side chain in the open state, allowing water molecules to exit to the surface or to reaccess the active site, This two-state model suggests the presence of an exit pathway for water between the active site and the protein surface. C1 LOS ALAMOS NATL LAB,THEORET BIOL & BIOPHYS GRP T10,LOS ALAMOS,NM 87545. LOS ALAMOS NATL LAB,CTR NONLINEAR STUDIES,LOS ALAMOS,NM 87545. RI Oprea, Tudor/A-5746-2011; Hummer, Gerhard/A-2546-2013 OI Oprea, Tudor/0000-0002-6195-6976; Hummer, Gerhard/0000-0001-7768-746X NR 45 TC 97 Z9 97 U1 0 U2 4 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 MAR 18 PY 1997 VL 94 IS 6 BP 2133 EP 2138 DI 10.1073/pnas.94.6.2133 PG 6 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA WP334 UT WOS:A1997WP33400011 PM 9122160 ER PT J AU Mann, DB Springer, DL Smerdon, MJ AF Mann, DB Springer, DL Smerdon, MJ TI DNA damage can alter the stability of nucleosomes: Effects are dependent on damage type SO PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA LA English DT Article ID BENZOPYRENE DIOL EPOXIDE; INDUCED 6-4 PHOTOPRODUCTS; CORE DNA; TRANSCRIPTION FACTOR; PYRIMIDINE DIMERS; COVALENT ADDUCTS; RNA-POLYMERASE; IN-VITRO; BINDING; REPAIR AB We have investigated the effects of DNA damage by (+/-)-anti-benzo[a] pyrene diol epoxide (BPDE) and UV light on the formation of a positioned nucleosome in the Xenopus borealis 5S rRNA gene. Gel-shift analysis of the reconstituted products indicates that BPDE damage facilitates the formation of a nucleosome onto this sequence, Competitive reconstitution experiments show that average levels of 0.5, 0.9, and 2.1 BPDE adducts/146 bp of 5S DNA (i.e., the size of DNA associated with a nucleosome core particle) yield changes of -220, -290, and -540 cal/mol, respectively, in the free energy (Delta G) of nucleosome formation, These values yield increases of core histone binding to 5S DNA (K-a) of 1.4-, 1.6-, and 2.5-fold, compared with undamaged DNA, Conversely, irradiation with UV light decreases nucleosome formation, Irradiation at either 500 or 2500 J/m(2) of UV light [0.6 and 0.8 cyclobutane pyrimidine dimer/146 bp (on average), respectively] results in respective changes of +130 and +250 cal/mol, This translates to decreases In core histone binding to irradiated 5S DNA (K-a) of 1.2- and 1.5-fold compared with undamaged DNA, These results indicate that nucleosome stability can be markedly affected by the formation of certain DNA lesions, Such changes could have major effects on the kinetics of DNA processing events. C1 WASHINGTON STATE UNIV, DEPT BIOCHEM & BIOPHYS, PULLMAN, WA 99164 USA. PACIFIC NW LAB, MOL BIOSCI DEPT, RICHLAND, WA 99352 USA. FU NIEHS NIH HHS [R01 ES002614, R37 ES002614, ES02614] NR 57 TC 46 Z9 48 U1 0 U2 1 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 MAR 18 PY 1997 VL 94 IS 6 BP 2215 EP 2220 DI 10.1073/pnas.94.6.2215 PG 6 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA WP334 UT WOS:A1997WP33400025 PM 9122174 ER PT J AU Millunchick, JM Twesten, RD Follstaedt, DM Lee, SR Jones, ED Zhang, Y Ahrenkiel, SP Mascarenhas, A AF Millunchick, JM Twesten, RD Follstaedt, DM Lee, SR Jones, ED Zhang, Y Ahrenkiel, SP Mascarenhas, A TI Lateral composition modulation in AlAs/InAs short period superlattices grown on InP(001) SO APPLIED PHYSICS LETTERS LA English DT Article ID EPITAXIAL LAYERS; QUANTUM-WELLS AB Spontaneous lateral composition modulation as a consequence of the deposition of a (AlAs)(n)/(InAs)(m) short period superlattice on an InP(001) substrate is examined, Transmission electron microscopy images show distinct composition modulation appearing as vertical regions of In- and Al-rich materials alternating in the [<(1)over bar 10>] projection. The periodicity of the modulation is 130 Angstrom, and is asymmetric. The transmission electron and x-ray diffraction patterns from the structure exhibit distinct satellite spots which correspond to the lateral periodicity. Transmission electron microscopy images show that the individual superlattice layers possess cusplike undulations, which directly correlate with the composition modulation. Composition modulation in this sample appears to be coupled to morphological and compositional instabilities at the surface due to strain. (C) 1997 American Institute of Physics. C1 NATL RENEWABLE ENERGY LAB,GOLDEN,CO 80401. RP Millunchick, JM (reprint author), SANDIA NATL LABS,POB 5800,ALBUQUERQUE,NM 87185, USA. NR 16 TC 44 Z9 44 U1 1 U2 4 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD MAR 17 PY 1997 VL 70 IS 11 BP 1402 EP 1404 PG 3 WC Physics, Applied SC Physics GA WM924 UT WOS:A1997WM92400024 ER PT J AU Zang, J Roder, H Bishop, AR Trugman, SA AF Zang, J Roder, H Bishop, AR Trugman, SA TI Magnetic properties of the double-exchange model SO JOURNAL OF PHYSICS-CONDENSED MATTER LA English DT Letter ID MAGNETORESISTANCE; RESISTIVITY; FILMS AB We study the ferromagnetic (FM) Kondo lattice model in the strong-coupling limit (the double-exchange (DE) model). The DE mechanism proposed by Zener to explain ferromagnetism is found to have unexpected properties when there is more than one itinerant electron. We End that, in general, the many-body ground state of the DE model is not globally FM ordered (except for in special filled-shell cases). Furthermore, the low-energy excitations of this model are distinct from those in usual Heisenberg ferromagnets, which will result in unusual dynamic magnetic properties. C1 LOS ALAMOS NATL LAB,CTR NONLINEAR STUDIES,MS B262,LOS ALAMOS,NM 87545. RP Zang, J (reprint author), LOS ALAMOS NATL LAB,DIV THEORET,MS B262,LOS ALAMOS,NM 87545, USA. NR 29 TC 41 Z9 41 U1 0 U2 4 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL, ENGLAND BS1 6BE SN 0953-8984 J9 J PHYS-CONDENS MAT JI J. Phys.-Condes. Matter PD MAR 17 PY 1997 VL 9 IS 11 BP L157 EP L163 DI 10.1088/0953-8984/9/11/001 PG 7 WC Physics, Condensed Matter SC Physics GA WP374 UT WOS:A1997WP37400001 ER PT J AU Thornton, LT AF Thornton, LT TI Hopeful SO NEW REPUBLIC LA English DT Letter RP Thornton, LT (reprint author), US DOE,WASHINGTON,DC 20202, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU NEW REPUBLIC INC PI WASHINGTON PA 1220 19TH ST NW SUITE 600, WASHINGTON, DC 20036 SN 0028-6583 J9 NEW REPUBLIC JI New Repub. PD MAR 17 PY 1997 VL 216 IS 11 BP 6 EP 7 PG 2 WC Political Science SC Government & Law GA WM373 UT WOS:A1997WM37300006 ER PT J AU Dimopoulos, S Thomas, S Wells, JD AF Dimopoulos, S Thomas, S Wells, JD TI Sparticle spectroscopy and electroweak symmetry breaking with gauge-mediated supersymmetry breaking SO NUCLEAR PHYSICS B LA English DT Article DE supersymmetry; gauge mediation; electroweak symmetry breaking; sparticle spectroscopy; Supersymmetry breaking; supersymmetry phenomenology ID SOFTLY BROKEN SUPERSYMMETRY; LOW-ENERGY SUPERGRAVITY; LIGHTEST HIGGS BOSON; FERMION MASSES; RADIATIVE-CORRECTIONS; MODEL; DECAY; TECHNICOLOR; B->S-GAMMA; COUPLINGS AB The phenomenology associated with gauge-mediated supersymmetry breaking is presented. A renormalization group analysis of the minimal model is performed in which the constraints of radiative electroweak symmetry breaking are imposed. The resulting superpartner and Higgs boson spectra are highly correlated and depend on only a few parameters. Superpartner mass ratios and sum rules are identified which can be tested at future colliders. Some of these relations are logarithmically sensitive to the messenger scale, while others allow gauge mediation to be distinguished from other schemes for transmitting supersymmetry breaking. Deviations from the minimal model, such as larger messenger representations and additional contributions to Higgs sector masses, can in some circumstances dramatically modify the low energy spectrum. These modifications include a slepton or Higgsino as the lightest standard model superpartner, or exotic mass relations among the scalars and gauginos. The contribution to b --> s gamma and resulting bound on superpartner masses are also presented for the minimal model Finally, the unique collider signatures of heavy charged particle production, or decay to the Goldstino within a detector are discussed. C1 STANFORD UNIV,DEPT PHYS,STANFORD,CA 94305. STANFORD LINEAR ACCELERATOR CTR,STANFORD,CA 94309. RP Dimopoulos, S (reprint author), CERN,DIV THEORET PHYS,CH-1211 GENEVA 23,SWITZERLAND. NR 85 TC 221 Z9 222 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0550-3213 J9 NUCL PHYS B JI Nucl. Phys. B PD MAR 17 PY 1997 VL 488 IS 1-2 BP 39 EP 91 DI 10.1016/S0550-3213(97)00030-8 PG 53 WC Physics, Particles & Fields SC Physics GA WL850 UT WOS:A1997WL85000002 ER PT J AU Kamionkowski, M Kosowsky, A Stebbins, A AF Kamionkowski, M Kosowsky, A Stebbins, A TI A probe of primordial gravity waves and vorticity SO PHYSICAL REVIEW LETTERS LA English DT Article ID MICROWAVE BACKGROUND-RADIATION; GRAVITATIONAL-WAVES; POLARIZATION; INFLATION; COBE AB A formalism for describing an all-sky map of the polarization of the cosmic microwave background is presented. The polarization pattern on the sky can be decomposed into two geometrically distinct components. One of these components is not coupled to density inhomogeneities. A nonzero amplitude for this component of polarization can only be caused by tensor or vector metric perturbations. This allows unambiguous identification of long-wavelength gravity waves or large-scale vortical flows at the time of last scattering. C1 HARVARD SMITHSONIAN CTR ASTROPHYS,CAMBRIDGE,MA 02138. HARVARD UNIV,LYMAN LAB,DEPT PHYS,CAMBRIDGE,MA 02138. FERMILAB NATL ACCELERATOR LAB,NASA,FERMILAB ASTROPHYS CTR,BATAVIA,IL 60510. RP Kamionkowski, M (reprint author), COLUMBIA UNIV,DEPT PHYS,538 W 120TH ST,NEW YORK,NY 10027, USA. NR 28 TC 419 Z9 419 U1 1 U2 4 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD MAR 17 PY 1997 VL 78 IS 11 BP 2058 EP 2061 DI 10.1103/PhysRevLett.78.2058 PG 4 WC Physics, Multidisciplinary SC Physics GA WN079 UT WOS:A1997WN07900007 ER PT J AU Bettencourt, LMA Laguna, P Matzner, RA AF Bettencourt, LMA Laguna, P Matzner, RA TI Nonintercommuting cosmic strings SO PHYSICAL REVIEW LETTERS LA English DT Article AB We perform the numerical field evolution for the collision of two Abelion type I cosmic strings. We present evidence that, for collisions at small but characteristic relative velocities and angles, these cosmic strings do nor exchange ends and separate. Rather, local higher winding number bound states are formed close to the collision point, which promote multiple local scatterings at right angles and prevent intercommutation from happening. This constitutes the simplest example of the breakdown of the intercommutation rule, usually assumed in the construction of effective models for cosmic string network evolution. C1 UNIV HEIDELBERG,INST THEORET PHYS,D-69120 HEIDELBERG,GERMANY. PENN STATE UNIV,DEPT ASTRON & ASTROPHYS,UNIVERSITY PK,PA 16802. PENN STATE UNIV,CTR GRAVITAT PHYS & GEOMETRY,UNIVERSITY PK,PA 16802. UNIV TEXAS,CTR RELAT,AUSTIN,TX 78712. LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545. RP Bettencourt, LMA (reprint author), UNIV LONDON IMPERIAL COLL SCI TECHNOL & MED,BLACKETT LAB,LONDON SW7 2BZ,ENGLAND. NR 15 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 MAR 17 PY 1997 VL 78 IS 11 BP 2066 EP 2069 DI 10.1103/PhysRevLett.78.2066 PG 4 WC Physics, Multidisciplinary SC Physics GA WN079 UT WOS:A1997WN07900009 ER PT J AU Abachi, S Abbott, B Abolins, M Acharya, BS Adam, I Adams, DL Adams, M Ahn, S Aihara, H Alvarez, G Alves, GA Amidi, E Amos, N Anderson, EW Aronson, SH Astur, R Baarmand, MM Baden, A Balamurali, V Balderston, J Baldin, B Banerjee, S Bantly, J Bartlett, JF Bazizi, K Belyaev, A Bendich, J Beri, SB Bertram, I Bezzubov, VA Bhat, PC Bhatnagar, V Bhattacharjee, M Bischoff, A Biswas, N Blazey, G Blessing, S Bloom, P Boehnlein, A Bojko, NI Borcherding, F Borders, J Boswell, C Brandt, A Brock, R Bross, A Buchholz, D Burtovoi, VS Butler, JM Carvalho, W Casey, D CastillaValdez, H Chakraborty, D Chang, SM Chekulaev, SV Chen, LP Chen, W Choi, S Chopra, S Choudhary, BC Christenson, JH Chung, M Claes, D Clark, AR Cobau, WG Cochran, J Cooper, WE Cretsinger, C CullenVidal, D Cummings, MAC Cutts, D Dahl, OI De, K DelSignore, K Demarteau, M Denisov, D Denisov, SP Diehl, HT Diesburg, M DiLoreto, G Draper, P Drinkard, J Ducros, Y Dudko, LV Dugad, SR Edmunds, D Ellison, J Elvira, VD Engelmann, R Eno, S Eppley, G Ermolov, P Eroshin, OV Evdokimov, VN Fahey, S Fahland, T Fatyga, M Fatyga, MK Featherly, J Feher, S Fein, D Ferbel, T Finocchiaro, G Fisk, HE Fisyak, Y Flattum, E Forden, GE Fortner, M Frame, KC Franzini, P Fuess, S Gallas, E Galyaev, AN Gartung, P Geld, TL Genik, RJ Genser, K Gerber, CE Gibbard, B Glebov, V Glenn, S Gobbi, B Goforth, M Goldschmidt, A Gomez, B Gomez, G Goncharov, PI Solis, JLG Gordon, H Goss, LT Goussiou, A Graf, N Grannis, PD Green, DR Green, J Greenlee, H Griffin, G Grim, G Grossman, N Grudberg, P Grunendahl, S Guglielmo, G Guida, JA Guida, JM Guryn, W Gurzhiev, SN Gutierrez, P Gutnikov, YE Hadley, NJ Haggerty, H Hagopian, S Hagopian, V Hahn, KS Hall, RE Hansen, S Hauptman, JM Hedin, D Heinson, AP Heintz, U HernandezMontoya, R Heuring, T Hirosky, R Hobbs, JD Hoeneisen, B Hoftun, JS Hsieh, F Hu, T Hu, T Huehn, T Ito, AS James, E Jaques, J Jerger, SA Jesik, R Jiang, JZY JoffeMinor, T Johns, K Johnson, M Jonckheere, A Jones, M Jostlein, H Jun, SY Jung, CK Kahn, S Kalbfleisch, G Kang, JS Kehoe, R Kelly, ML Kerth, L Kim, CL Kim, SK Klatchko, A Klima, B Klochkov, BI Klopfenstein, C Klyukhin, VI Kochetkov, VI Kohli, JM Koltick, D Kostritskiy, AV Kotcher, J Kotwal, AV Kourlas, J Kozelov, AV Kozlovski, EA Krane, J Krishnaswamy, MR Krzywdzinski, S Kunori, S Lami, S Lan, H Landsberg, G Lauer, B Lebrat, JF Leflat, A Li, H Li, J Li, YK LiDemarteau, QZ Lima, JGR Lincoln, D Linn, SL Linnemann, J Lipton, R Liu, Q Liu, YC Lobkowicz, F Loken, SC Lokos, S Lueking, L Lyon, AL Maciel, AKA Madaras, RJ Madden, R MaganaMendoza, L Mani, S Mao, HS Markeloff, R Markosky, L Marshall, T Martin, MI May, B Mayorov, AA McCarthy, R McDonald, J McKibben, T McKinley, J McMahon, T Melanson, HL Merritt, KW Miettinen, H Mincer, A deMiranda, JM Mishra, CS Mokhov, N Mondal, NK Montgomery, HE Mooney, P daMotta, H Mudan, M Murphy, C Nang, F Narain, M Narasimham, VS Narayanan, A Neal, HA Negret, JP Nemethy, P Nesic, D Nicola, M Norman, D Oesch, L Oguri, V Oltman, E Oshima, N Owen, D Padley, P Pang, M Para, A Park, YM Partridge, R Parua, N Paterno, M Perkins, J Peters, M Piekarz, H Pischalnikov, Y Podstavkov, VM Pope, BG Prosper, HB Protopopescu, S Puseljic, D Qian, J Quintas, PZ Raja, R Rajagopalan, S Ramirez, O Rapidis, PA Rasmussen, L Reucroft, S Rijssenbeek, M Rockwell, T Roe, NA Rubinov, P Ruchti, R Rutherfoord, J SanchezHernandez, A Santoro, A Sawyer, L Schamberger, RD Schellman, H Sculli, J Shabalina, E Shaffer, C Shankar, HC Shivpuri, RK Shupe, M Singh, H Singh, JB Sirotenko, V Smart, W Smith, A Smith, RP Snihur, R Snow, GR Snow, J Snyder, S Solomon, J Sood, PM Sosebee, M Sotnikova, N Souza, M Spadafora, AL Stephens, RW Stevenson, ML Stewart, D Stoianova, DA Stoker, D Streets, K Strovink, M Sznajder, A Tamburello, P Tarazi, J Tartaglia, M Thomas, TLT Thompson, J Trippe, TG Tuts, PM Varelas, N Varnes, EW Vititoe, D Volkov, AA Vorobiev, AP Wahl, HD Wang, G Warchol, J Watts, G Wayne, M Weerts, H White, A White, JT Wightman, JA Willis, S Wimpenny, SJ Wirjawan, JVD Womersley, J Won, E Wood, DR Xu, H Yamada, R Yamin, P Yanagisawa, C Yang, J Yasuda, T Yepes, P Yoshikawa, C Youssef, S Yu, J Yu, Y Zhu, Q Zhu, ZH Zieminska, D Zieminski, A Zverev, EG Zylberstejn, A AF Abachi, S Abbott, B Abolins, M Acharya, BS Adam, I Adams, DL Adams, M Ahn, S Aihara, H Alvarez, G Alves, GA Amidi, E Amos, N Anderson, EW Aronson, SH Astur, R Baarmand, MM Baden, A Balamurali, V Balderston, J Baldin, B Banerjee, S Bantly, J Bartlett, JF Bazizi, K Belyaev, A Bendich, J Beri, SB Bertram, I Bezzubov, VA Bhat, PC Bhatnagar, V Bhattacharjee, M Bischoff, A Biswas, N Blazey, G Blessing, S Bloom, P Boehnlein, A Bojko, NI Borcherding, F Borders, J Boswell, C Brandt, A Brock, R Bross, A Buchholz, D Burtovoi, VS Butler, JM Carvalho, W Casey, D CastillaValdez, H Chakraborty, D Chang, SM Chekulaev, SV Chen, LP Chen, W Choi, S Chopra, S Choudhary, BC Christenson, JH Chung, M Claes, D Clark, AR Cobau, WG Cochran, J Cooper, WE Cretsinger, C CullenVidal, D Cummings, MAC Cutts, D Dahl, OI De, K DelSignore, K Demarteau, M Denisov, D Denisov, SP Diehl, HT Diesburg, M DiLoreto, G Draper, P Drinkard, J Ducros, Y Dudko, LV Dugad, SR Edmunds, D Ellison, J Elvira, VD Engelmann, R Eno, S Eppley, G Ermolov, P Eroshin, OV Evdokimov, VN Fahey, S Fahland, T Fatyga, M Fatyga, MK Featherly, J Feher, S Fein, D Ferbel, T Finocchiaro, G Fisk, HE Fisyak, Y Flattum, E Forden, GE Fortner, M Frame, KC Franzini, P Fuess, S Gallas, E Galyaev, AN Gartung, P Geld, TL Genik, RJ Genser, K Gerber, CE Gibbard, B Glebov, V Glenn, S Gobbi, B Goforth, M Goldschmidt, A Gomez, B Gomez, G Goncharov, PI Solis, JLG Gordon, H Goss, LT Goussiou, A Graf, N Grannis, PD Green, DR Green, J Greenlee, H Griffin, G Grim, G Grossman, N Grudberg, P Grunendahl, S Guglielmo, G Guida, JA Guida, JM Guryn, W Gurzhiev, SN Gutierrez, P Gutnikov, YE Hadley, NJ Haggerty, H Hagopian, S Hagopian, V Hahn, KS Hall, RE Hansen, S Hauptman, JM Hedin, D Heinson, AP Heintz, U HernandezMontoya, R Heuring, T Hirosky, R Hobbs, JD Hoeneisen, B Hoftun, JS Hsieh, F Hu, T Hu, T Huehn, T Ito, AS James, E Jaques, J Jerger, SA Jesik, R Jiang, JZY JoffeMinor, T Johns, K Johnson, M Jonckheere, A Jones, M Jostlein, H Jun, SY Jung, CK Kahn, S Kalbfleisch, G Kang, JS Kehoe, R Kelly, ML Kerth, L Kim, CL Kim, SK Klatchko, A Klima, B Klochkov, BI Klopfenstein, C Klyukhin, VI Kochetkov, VI Kohli, JM Koltick, D Kostritskiy, AV Kotcher, J Kotwal, AV Kourlas, J Kozelov, AV Kozlovski, EA Krane, J Krishnaswamy, MR Krzywdzinski, S Kunori, S Lami, S Lan, H Landsberg, G Lauer, B Lebrat, JF Leflat, A Li, H Li, J Li, YK LiDemarteau, QZ Lima, JGR Lincoln, D Linn, SL Linnemann, J Lipton, R Liu, Q Liu, YC Lobkowicz, F Loken, SC Lokos, S Lueking, L Lyon, AL Maciel, AKA Madaras, RJ Madden, R MaganaMendoza, L Mani, S Mao, HS Markeloff, R Markosky, L Marshall, T Martin, MI May, B Mayorov, AA McCarthy, R McDonald, J McKibben, T McKinley, J McMahon, T Melanson, HL Merritt, KW Miettinen, H Mincer, A deMiranda, JM Mishra, CS Mokhov, N Mondal, NK Montgomery, HE Mooney, P daMotta, H Mudan, M Murphy, C Nang, F Narain, M Narasimham, VS Narayanan, A Neal, HA Negret, JP Nemethy, P Nesic, D Nicola, M Norman, D Oesch, L Oguri, V Oltman, E Oshima, N Owen, D Padley, P Pang, M Para, A Park, YM Partridge, R Parua, N Paterno, M Perkins, J Peters, M Piekarz, H Pischalnikov, Y Podstavkov, VM Pope, BG Prosper, HB Protopopescu, S Puseljic, D Qian, J Quintas, PZ Raja, R Rajagopalan, S Ramirez, O Rapidis, PA Rasmussen, L Reucroft, S Rijssenbeek, M Rockwell, T Roe, NA Rubinov, P Ruchti, R Rutherfoord, J SanchezHernandez, A Santoro, A Sawyer, L Schamberger, RD Schellman, H Sculli, J Shabalina, E Shaffer, C Shankar, HC Shivpuri, RK Shupe, M Singh, H Singh, JB Sirotenko, V Smart, W Smith, A Smith, RP Snihur, R Snow, GR Snow, J Snyder, S Solomon, J Sood, PM Sosebee, M Sotnikova, N Souza, M Spadafora, AL Stephens, RW Stevenson, ML Stewart, D Stoianova, DA Stoker, D Streets, K Strovink, M Sznajder, A Tamburello, P Tarazi, J Tartaglia, M Thomas, TLT Thompson, J Trippe, TG Tuts, PM Varelas, N Varnes, EW Vititoe, D Volkov, AA Vorobiev, AP Wahl, HD Wang, G Warchol, J Watts, G Wayne, M Weerts, H White, A White, JT Wightman, JA Willis, S Wimpenny, SJ Wirjawan, JVD Womersley, J Won, E Wood, DR Xu, H Yamada, R Yamin, P Yanagisawa, C Yang, J Yasuda, T Yepes, P Yoshikawa, C Youssef, S Yu, J Yu, Y Zhu, Q Zhu, ZH Zieminska, D Zieminski, A Zverev, EG Zylberstejn, A TI Search for diphoton events with large missing transverse energy in p(p)over-bar collisions at root s=1.8 TeV SO PHYSICAL REVIEW LETTERS LA English DT Article AB A search for new physics has been carried out in the channel --> gamma gamma + is not an element of(T), as expected in various supersymmetric models. We require two photons with transverse energy E(T)(gamma) > 12 GeV and pseudorapidity \eta(gamma)\ < 1.1. The distribution of missing transverse energy (is not an element of(T)) is consistent with background and no events have is not an element of(T) > 25 GeV. We set limits on production cross sections for selectron, sneutrino, and neutralino pairs, decaying into photons, which range from about 400 fb to 1 pb depending on the sparticle masses. A general limit of 185 fb (95% C.L.) is set on sigma( --> gamma gamma is not an element of(T) + X), where E(T)(gamma) > 12 GeV, \eta(gamma)\ < 1.1, and is not an element of(T) > 25 GeV. C1 UNIV LOS ANDES,BOGOTA,COLOMBIA. UNIV ARIZONA,TUCSON,AZ 85721. BOSTON UNIV,BOSTON,MA 02215. BROOKHAVEN NATL LAB,UPTON,NY 11973. BROWN UNIV,PROVIDENCE,RI 02912. UNIV BUENOS AIRES,BUENOS AIRES,DF,ARGENTINA. UNIV CALIF DAVIS,DAVIS,CA 95616. UNIV CALIF IRVINE,IRVINE,CA 92717. UNIV CALIF RIVERSIDE,RIVERSIDE,CA 92521. CTR BRASILEIRO PESQUISAS FIS,LAFEX,RIO JANEIRO,BRAZIL. CINVESTAV IPN,MEXICO CITY 14000,DF,MEXICO. COLUMBIA UNIV,NEW YORK,NY 10027. UNIV DELHI,DELHI 110007,INDIA. FLORIDA STATE UNIV,TALLAHASSEE,FL 32306. UNIV HAWAII,HONOLULU,HI 96822. UNIV ILLINOIS,CHICAGO,IL 60607. INDIANA UNIV,BLOOMINGTON,IN 47405. IOWA STATE UNIV,AMES,IA 50011. KOREA UNIV,SEOUL 136701,SOUTH KOREA. KYUNGSUNG UNIV,PUSAN 608736,SOUTH KOREA. UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,BERKELEY,CA 94720. UNIV MARYLAND,COLLEGE PK,MD 20742. UNIV MICHIGAN,ANN ARBOR,MI 48109. MICHIGAN STATE UNIV,E LANSING,MI 48824. MOSCOW MV LOMONOSOV STATE UNIV,MOSCOW,RUSSIA. UNIV NEBRASKA,LINCOLN,NE 68588. NYU,NEW YORK,NY 10003. NORTHEASTERN UNIV,BOSTON,MA 02115. UNIV NOTRE DAME,NOTRE DAME,IN 46556. UNIV OKLAHOMA,NORMAN,OK 73019. PANJAB UNIV,CHANDIGARH 160014,INDIA. INST HIGH ENERGY PHYS,PROTVINO 142284,RUSSIA. PURDUE UNIV,W LAFAYETTE,IN 47907. RICE UNIV,HOUSTON,TX 77005. UNIV ESTADUAL RIO DE JANEIRO,RIO JANEIRO,BRAZIL. UNIV ROCHESTER,ROCHESTER,NY 14627. CE SACLAY,SERV PHYS PARTICULES,DAPNIA,CEA,GIF SUR YVETTE,FRANCE. SEOUL NATL UNIV,SEOUL,SOUTH KOREA. SUNY STONY BROOK,STONY BROOK,NY 11794. NO ILLINOIS UNIV,DE KALB,IL 60115. NORTHWESTERN UNIV,EVANSTON,IL 60208. TATA INST FUNDAMENTAL RES,BOMBAY 400005,MAHARASHTRA,INDIA. UNIV TEXAS,ARLINGTON,TX 76019. TEXAS A&M UNIV,COLLEGE STN,TX 77843. RP Abachi, S (reprint author), FERMILAB NATL ACCELERATOR LAB,POB 500,BATAVIA,IL 60510, USA. RI Peters, Michael/B-4973-2009; Aihara, Hiroaki/F-3854-2010; Shivpuri, R K/A-5848-2010; Gutierrez, Phillip/C-1161-2011; Dudko, Lev/D-7127-2012; Santoro, Alberto/E-7932-2014; Belyaev, Alexander/F-6637-2015; Leflat, Alexander/D-7284-2012; Klyukhin, Vyacheslav/D-6850-2012; De, Kaushik/N-1953-2013; Oguri, Vitor/B-5403-2013; Alves, Gilvan/C-4007-2013; Kim, Sun Kee/G-2042-2015; Chekulaev, Sergey/O-1145-2015; Sznajder, Andre/L-1621-2016 OI Aihara, Hiroaki/0000-0002-1907-5964; Dudko, Lev/0000-0002-4462-3192; Belyaev, Alexander/0000-0002-1733-4408; Klyukhin, Vyacheslav/0000-0002-8577-6531; De, Kaushik/0000-0002-5647-4489; Kim, Sun Kee/0000-0002-0013-0775; Sznajder, Andre/0000-0001-6998-1108 NR 11 TC 29 Z9 29 U1 0 U2 4 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD MAR 17 PY 1997 VL 78 IS 11 BP 2070 EP 2074 DI 10.1103/PhysRevLett.78.2070 PG 5 WC Physics, Multidisciplinary SC Physics GA WN079 UT WOS:A1997WN07900010 ER PT J AU Abe, K Abe, K Abt, I Akagi, T Allen, NJ Ash, WW Aston, D Baird, KG Baltay, C Band, HR Barakat, MB Baranko, G Bardon, O Barklow, TL Bashindzhagyan, GL Bazarko, AO BenDavid, R Benvenuti, AC Bilei, GM Bisello, D Blaylock, G Bogart, JR Bolen, B Bolton, T Bower, GR Brau, JE Breidenbach, M Bugg, WM Burke, D Burnett, TH Burrows, PN Busza, W Calcaterra, A Caldwell, DO Calloway, D Camanzi, B Carpinelli, M Cassell, R Castaldi, R Castro, A CavalliSforza, M Chou, A Church, E Cohn, HO Coller, JA Cook, V Cotton, R Cowan, RF Coyne, DG Crawford, G DOliveira, A Damerell, CJS Daoudi, M DeSangro, R DellOrso, R Dervan, PJ Dima, M Dong, DN Du, PYC Dubois, R Eisenstein, BI Elia, R Etzion, E Fahey, S Falciai, D Fan, C Fero, MJ Frey, R Furuno, K Gillman, T Gladding, G Gonzalez, S Hallewell, GD Hart, EL Harton, JL Hasan, A Hasegawa, Y Hasuko, K Hedges, SJ Hertzbach, SS Hildreth, MD Huber, J Huffer, ME Hughes, EW Hwang, H Iwasaki, Y Jackson, DJ Jacques, P Jaros, JA Johnson, AS Johnson, JR Johnson, RA Junk, T Kajikawa, R Kalelkar, M Kang, HJ Karliner, I Kawahara, H Kendall, HW Kim, YD King, ME King, R Kofler, RR Krishna, NM Kroeger, RS Labs, JF Langston, M Lath, A Lauber, JA Leith, DWGS Lia, V Liu, MX Liu, X Loreti, M Lu, A Lynch, HL Ma, J Mancinelli, G Manly, S Mantovani, G Markiewicz, TW Maruyama, T Masuda, H Mazzucato, E McKemey, AK Meadows, BT Messner, R Mockett, PM Moffeit, KC Moore, TB Muller, D Nagamine, T Narita, S Nauenberg, U Neal, H Nussbaum, M Ohnishi, Y Osborne, LS Panvini, RS Park, CH Park, H Pavel, TJ Peruzzi, I Piccolo, M Piemontese, L Pieroni, E Pitts, KT Plano, RJ Prepost, R Prescott, CY Punkar, GD Quigley, J Ratcliff, BN Reeves, K Reeves, TW Reidy, J Reinertsen, PL Rensing, PE Rochester, LS Rowson, PC Russell, JJ Saxton, OH Schalk, T Schindler, RH Schumm, BA Schwiening, J Sen, S Serbo, VV Shaevitz, MH Shank, JT Shapiro, G Sherden, DJ Shmakov, KD Simopoulos, C Sinev, NB Smith, SR Smy, MB Snyder, JA Stamer, P Steiner, H Steiner, R Strauss, MG Su, D Suekane, F Sugiyama, A Suzuki, S Swartz, M Szumilo, A Takahashi, T Taylor, FE Torrence, E Trandafir, AI Turk, JD Usher, T Vavra, J Vannini, C Vella, E Venuti, JP Verdier, R Verdini, PG Wagner, DL Wagner, SR Waite, AP Watts, SJ Weidemann, AW Weiss, ER Whitaker, JS White, SL Wickens, FJ Williams, DA Williams, DC Williams, SH Willocq, S Wilson, RJ Wisniewski, WJ Woods, M Word, GB Wyss, J Yamamoto, RK Yamartino, JM Yang, X Yellin, SJ Young, CC Yuta, H Zapalac, G Zdarko, RW Zhou, J AF Abe, K Abe, K Abt, I Akagi, T Allen, NJ Ash, WW Aston, D Baird, KG Baltay, C Band, HR Barakat, MB Baranko, G Bardon, O Barklow, TL Bashindzhagyan, GL Bazarko, AO BenDavid, R Benvenuti, AC Bilei, GM Bisello, D Blaylock, G Bogart, JR Bolen, B Bolton, T Bower, GR Brau, JE Breidenbach, M Bugg, WM Burke, D Burnett, TH Burrows, PN Busza, W Calcaterra, A Caldwell, DO Calloway, D Camanzi, B Carpinelli, M Cassell, R Castaldi, R Castro, A CavalliSforza, M Chou, A Church, E Cohn, HO Coller, JA Cook, V Cotton, R Cowan, RF Coyne, DG Crawford, G DOliveira, A Damerell, CJS Daoudi, M DeSangro, R DellOrso, R Dervan, PJ Dima, M Dong, DN Du, PYC Dubois, R Eisenstein, BI Elia, R Etzion, E Fahey, S Falciai, D Fan, C Fero, MJ Frey, R Furuno, K Gillman, T Gladding, G Gonzalez, S Hallewell, GD Hart, EL Harton, JL Hasan, A Hasegawa, Y Hasuko, K Hedges, SJ Hertzbach, SS Hildreth, MD Huber, J Huffer, ME Hughes, EW Hwang, H Iwasaki, Y Jackson, DJ Jacques, P Jaros, JA Johnson, AS Johnson, JR Johnson, RA Junk, T Kajikawa, R Kalelkar, M Kang, HJ Karliner, I Kawahara, H Kendall, HW Kim, YD King, ME King, R Kofler, RR Krishna, NM Kroeger, RS Labs, JF Langston, M Lath, A Lauber, JA Leith, DWGS Lia, V Liu, MX Liu, X Loreti, M Lu, A Lynch, HL Ma, J Mancinelli, G Manly, S Mantovani, G Markiewicz, TW Maruyama, T Masuda, H Mazzucato, E McKemey, AK Meadows, BT Messner, R Mockett, PM Moffeit, KC Moore, TB Muller, D Nagamine, T Narita, S Nauenberg, U Neal, H Nussbaum, M Ohnishi, Y Osborne, LS Panvini, RS Park, CH Park, H Pavel, TJ Peruzzi, I Piccolo, M Piemontese, L Pieroni, E Pitts, KT Plano, RJ Prepost, R Prescott, CY Punkar, GD Quigley, J Ratcliff, BN Reeves, K Reeves, TW Reidy, J Reinertsen, PL Rensing, PE Rochester, LS Rowson, PC Russell, JJ Saxton, OH Schalk, T Schindler, RH Schumm, BA Schwiening, J Sen, S Serbo, VV Shaevitz, MH Shank, JT Shapiro, G Sherden, DJ Shmakov, KD Simopoulos, C Sinev, NB Smith, SR Smy, MB Snyder, JA Stamer, P Steiner, H Steiner, R Strauss, MG Su, D Suekane, F Sugiyama, A Suzuki, S Swartz, M Szumilo, A Takahashi, T Taylor, FE Torrence, E Trandafir, AI Turk, JD Usher, T Vavra, J Vannini, C Vella, E Venuti, JP Verdier, R Verdini, PG Wagner, DL Wagner, SR Waite, AP Watts, SJ Weidemann, AW Weiss, ER Whitaker, JS White, SL Wickens, FJ Williams, DA Williams, DC Williams, SH Willocq, S Wilson, RJ Wisniewski, WJ Woods, M Word, GB Wyss, J Yamamoto, RK Yamartino, JM Yang, X Yellin, SJ Young, CC Yuta, H Zapalac, G Zdarko, RW Zhou, J TI Improved measurement of the left-right Z(0) cross section asymmetry SO PHYSICAL REVIEW LETTERS LA English DT Article ID Z-BOSON PRODUCTION; E+E COLLISIONS; TOP-QUARK; DETECTOR AB We present a new 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 91.28 GeV with the SLD detector at the SLAC Linear Collider (SLC), The luminosity-weighted average polarization of the SLC electron beam was (77.23 +/- 0.52)%. Using a sample of 93644 Z decays, we measure the pole value of the asymmetry, A(LR)(0), to be 0.1512 +/- 0.0042(stat) +/- 0.0011(syst). which is equivalent to an effective weak mixing angle of sin(2) theta(W)(eff) = 0.23100 +/- 0.00054(stat) +/- 0.00014(syst). C1 ADELPHI UNIV, GARDEN CITY, NY 11530 USA. IST NAZL FIS NUCL, I-40126 BOLOGNA, ITALY. BOSTON UNIV, BOSTON, MA 02215 USA. BRUNEL UNIV, UXBRIDGE UB8 3PH, MIDDX, ENGLAND. UNIV CALIF SANTA BARBARA, SANTA BARBARA, CA 93106 USA. UNIV CALIF SANTA CRUZ, SANTA CRUZ, CA 95064 USA. UNIV CINCINNATI, CINCINNATI, OH 45221 USA. COLORADO STATE UNIV, FT COLLINS, CO 80523 USA. UNIV COLORADO, BOULDER, CO 80309 USA. COLUMBIA UNIV, NEW YORK, NY 10027 USA. IST NAZL FIS NUCL, I-44100 FERRARA, ITALY. UNIV FERRARA, I-44100 FERRARA, ITALY. IST NAZL FIS NUCL, LAB NAZL FRASCATI, I-00044 FRASCATI, ITALY. UNIV ILLINOIS, URBANA, IL 61801 USA. UNIV CALIF BERKELEY, LAWRENCE BERKELEY LAB, BERKELEY, CA 94720 USA. MIT, CAMBRIDGE, MA 02139 USA. UNIV MASSACHUSETTS, AMHERST, MA 01003 USA. UNIV MISSISSIPPI, UNIVERSITY, MS 38677 USA. MOSCOW MV LOMONOSOV STATE UNIV, INST NUCL PHYS, MOSCOW 119899, RUSSIA. UNIV OREGON, EUGENE, OR 97403 USA. IST NAZL FIS NUCL, I-35100 PADUA, ITALY. UNIV PADUA, I-35100 PADUA, ITALY. IST NAZL FIS NUCL, I-06100 PERUGIA, ITALY. UNIV PERUGIA, I-06100 PERUGIA, ITALY. IST NAZL FIS NUCL, I-56100 PISA, ITALY. UNIV PISA, I-56100 PISA, ITALY. RUTGERS STATE UNIV, PISCATAWAY, NJ 08855 USA. RUTHERFORD APPLETON LAB, DIDCOT OX11 0QX, OXON, ENGLAND. SOGANG UNIV, SEOUL, SOUTH KOREA. SOONGSIL UNIV, SEOUL 156743, SOUTH KOREA. STANFORD UNIV, STANFORD LINEAR ACCELERATOR CTR, STANFORD, CA 94309 USA. UNIV TENNESSEE, KNOXVILLE, TN 37996 USA. TOHOKU UNIV, SENDAI, MIYAGI 980, JAPAN. VANDERBILT UNIV, NASHVILLE, TN 37235 USA. UNIV WASHINGTON, SEATTLE, WA 98195 USA. UNIV WISCONSIN, MADISON, WI 53706 USA. YALE UNIV, NEW HAVEN, CT 06511 USA. UNIV GENOA, I-16146 GENOA, ITALY. RP Abe, K (reprint author), NAGOYA UNIV, CHIKUSA KU, NAGOYA, AICHI 484, JAPAN. RI de Sangro, Riccardo/J-2901-2012; Cavalli-Sforza, Matteo/H-7102-2015; Calcaterra, Alessandro/P-5260-2015; Frey, Raymond/E-2830-2016; OI de Sangro, Riccardo/0000-0002-3808-5455; Calcaterra, Alessandro/0000-0003-2670-4826; Frey, Raymond/0000-0003-0341-2636; pieroni, enrico/0000-0002-4246-6963; Wyss, Jeffery/0000-0002-8277-4012 NR 21 TC 37 Z9 37 U1 0 U2 0 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD MAR 17 PY 1997 VL 78 IS 11 BP 2075 EP 2079 DI 10.1103/PhysRevLett.78.2075 PG 5 WC Physics, Multidisciplinary SC Physics GA WN079 UT WOS:A1997WN07900011 ER PT J AU Bearden, IG Boggild, H Boissevain, J Dodd, J Erazmus, B Esumi, S Fabjan, CW Ferenc, D Fields, DE Franz, A Gaardhoje, JJ Hansen, AG Hansen, O Hardtke, D vanHecke, H Holzer, EB Humanic, TJ Hummel, P Jacak, BV Jayanti, R Kalechofsky, H Kaneta, M Kopytine, M Lee, YY Leltchouk, M Ljubicic, T Lorstad, B Maeda, N Malina, R Medvedev, A Murray, M Nishimura, S Ohnishi, H Paic, G Pandey, SU Piuz, F Pluta, J Polychronakos, V Potekhin, M Poulard, G Reichhold, D Sakaguchi, A SimonGillo, J SchmidtSorensen, J Sondheim, W Spegel, M Sugitate, T Sullivan, JP Sumi, Y Willis, WJ Wolf, K Xu, N Zachary, DS AF Bearden, IG Boggild, H Boissevain, J Dodd, J Erazmus, B Esumi, S Fabjan, CW Ferenc, D Fields, DE Franz, A Gaardhoje, JJ Hansen, AG Hansen, O Hardtke, D vanHecke, H Holzer, EB Humanic, TJ Hummel, P Jacak, BV Jayanti, R Kalechofsky, H Kaneta, M Kopytine, M Lee, YY Leltchouk, M Ljubicic, T Lorstad, B Maeda, N Malina, R Medvedev, A Murray, M Nishimura, S Ohnishi, H Paic, G Pandey, SU Piuz, F Pluta, J Polychronakos, V Potekhin, M Poulard, G Reichhold, D Sakaguchi, A SimonGillo, J SchmidtSorensen, J Sondheim, W Spegel, M Sugitate, T Sullivan, JP Sumi, Y Willis, WJ Wolf, K Xu, N Zachary, DS TI Collective expansion in high energy heavy ion collisions SO PHYSICAL REVIEW LETTERS LA English DT Article ID NUCLEUS-NUCLEUS COLLISIONS; INTERSECTING STORAGE-RINGS; TRANSVERSE-MOMENTUM; AU+AU COLLISIONS; LARGE ANGLES; 14.6A GEV/C; SPECTRA; DISTRIBUTIONS; PIONS; AGS AB Transverse mass spectra of pions, kaons, and protons from the symmetric heavy-ion collisions 200A GeV S + S and 158A GeV Pb + Pb, measured in the NA44 focusing spectrometer at CERN, are presented. The mass dependence of the slope parameters provides evidence of collective transverse flow from expansion of the system in heavy-ion induced central collisions. C1 LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545. COLUMBIA UNIV,DEPT PHYS,NEW YORK,NY 10027. NUCL PHYS LAB NANTES,F-44072 NANTES,FRANCE. HIROSHIMA UNIV,HIGASHIHIROSHIMA 739,JAPAN. CERN,CH-1211 GENEVA 23,SWITZERLAND. RUDJER BOSKOVIC INST,ZAGREB,CROATIA. OHIO STATE UNIV,DEPT PHYS,COLUMBUS,OH 43210. VIENNA TECH UNIV,A-1040 VIENNA,AUSTRIA. LUND UNIV,DEPT PHYS,S-22362 LUND,SWEDEN. TEXAS A&M UNIV,COLLEGE STN,TX 77843. BROOKHAVEN NATL LAB,UPTON,NY 11973. RP Bearden, IG (reprint author), NIELS BOHR INST,BLEGDAMSVEJ 17,DK-2100 COPENHAGEN,DENMARK. RI Bearden, Ian/M-4504-2014 OI Bearden, Ian/0000-0003-2784-3094 NR 34 TC 242 Z9 243 U1 0 U2 3 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD MAR 17 PY 1997 VL 78 IS 11 BP 2080 EP 2083 DI 10.1103/PhysRevLett.78.2080 PG 4 WC Physics, Multidisciplinary SC Physics GA WN079 UT WOS:A1997WN07900012 ER PT J AU Gates, E Kamionkowski, M Turner, MS AF Gates, E Kamionkowski, M Turner, MS TI Dispersion velocity of galactic dark matter particles - Comment SO PHYSICAL REVIEW LETTERS LA English DT Article ID KINEMATICS; GALAXY C1 UNIV CHICAGO,ENRICO FERMI INST,DEPT ASTRON & ASTROPHYS,CHICAGO,IL 60637. UNIV CHICAGO,ENRICO FERMI INST,DEPT PHYS,CHICAGO,IL 60637. COLUMBIA UNIV,DEPT PHYS,NEW YORK,NY 10027. RP Gates, E (reprint author), NASA,FERMI NATL ACCELERATOR LAB,FERMILAB THEORET ASTROPHYS CTR,BATAVIA,IL 60615, USA. NR 6 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 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD MAR 17 PY 1997 VL 78 IS 11 BP 2261 EP 2261 DI 10.1103/PhysRevLett.78.2261 PG 1 WC Physics, Multidisciplinary SC Physics GA WN079 UT WOS:A1997WN07900058 ER PT J AU Nicolussi, GK Pellin, MJ Calaway, WF Lewis, RS Davis, AM Amari, S Clayton, RN AF Nicolussi, GK Pellin, MJ Calaway, WF Lewis, RS Davis, AM Amari, S Clayton, RN TI Isotopic analysis of Ca from extraterrestrial micrometer-sized SiC by laser desorption and resonant ionization mass spectroscopy SO ANALYTICAL CHEMISTRY LA English DT Article ID SILICON-CARBIDE; SPECTROMETRY; GRAINS AB The isotopic composition of calcium in a 2.8 mu m SiC grain, isolated from the Murchison CM2 meteorite, has been measured by resonant ionization mass spectroscopy with a two-color (2 omega + omega) ionization scheme, The sample was atomized by laser-induced thermal desorption by a pulsed N-2 gas laser and mass-analyzed in a time-of-flight mass spectrometer (TOFMS). The Ca ionization scheme results in excellent discrimination against isobaric interferences from SiC, SiO, C-4, and Ti, To investigate possible mass-dependent variations in the postionization efficiency or TOFMS transmission, we have also measured the isotopic abundance of Ca from a terrestrial SiC sample (similar to 130 ppm Ca concentration) using the same experimental parameters, Furthermore, we have measured the isotopic composition of Ca ion-sputtered with Ar+ from a pure terrestrial Ca target to determine isotopic variations of the ionization efficiency. Within statistical uncertainty, the isotopic abundance of Ca from the meteoritic SIC grain does not reveal any deviation from the values obtained from Ca in terrestrial SiC. However, the isotopic pattern of Si, measured with nonresonant ArF laser postionization, shows a significant enhancement of Si-29 and Si-30. This clearly indicates the extraterrestrial origin of the analyzed SiC grain, The results of this work are encouraging: the combination of pulsed laser desorption, resonant ionization, and TOFMS is useful for isotopic analysis of elements at trace concentrations in micrometer-sized particles, This is particularly interesting for the study of presolar interstellar grains, where isotopic anomalies relative to terrestrial composition are large and conventional methods, such as SIMS, can suffer from unresolved isobaric interferences. C1 ARGONNE NATL LAB,DIV MAT SCI,ARGONNE,IL 60439. ARGONNE NATL LAB,DIV CHEM,ARGONNE,IL 60439. UNIV CHICAGO,ENRICO FERMI INST,CHICAGO,IL 60637. UNIV CHICAGO,DEPT CHEM,CHICAGO,IL 60637. UNIV CHICAGO,DEPT GEOPHYS SCI,CHICAGO,IL 60637. WASHINGTON UNIV,MCDONNEL CTR SPACE SCI,ST LOUIS,MO 63130. RI Pellin, Michael/B-5897-2008; OI Pellin, Michael/0000-0002-8149-9768; Davis, Andrew/0000-0001-7955-6236 NR 13 TC 30 Z9 30 U1 0 U2 3 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0003-2700 J9 ANAL CHEM JI Anal. Chem. PD MAR 15 PY 1997 VL 69 IS 6 BP 1140 EP 1146 DI 10.1021/ac960871k PG 7 WC Chemistry, Analytical SC Chemistry GA WM550 UT WOS:A1997WM55000025 ER PT J AU Ramsey, RS Ramsey, JM AF Ramsey, RS Ramsey, JM TI Generating electrospray from microchip devices using electroosmotic pumping SO ANALYTICAL CHEMISTRY LA English DT Article ID ELECTROPHORESIS MASS-SPECTROMETRY; PLANAR CHIPS TECHNOLOGY; CAPILLARY ELECTROPHORESIS; SEPARATION; IONIZATION; MINIATURIZATION; PERFORMANCE; EFFICIENCY; INJECTION; INTERFACE AB A method of generating electrospray from solutions emerging from small channels etched on planar substrates is described. The fluids are delivered using electroosmotically induced pressures and are sprayed electrostatically from the terminus of a channel by applying an electrical potential of sufficient amplitude to generate the electrospray between the microchip and a conductor spaced from the channel terminus. No major modification of the microchip is required other than to expose a channel opening. The principles that regulate the fluid delivery are described and demonstrated. A spectrum for a test compound, tetrabutylammonium iodide, that was continuously electrophoresed was obtained by coupling the microchip to an ion trap mass spectrometer. C1 OAK RIDGE NATL LAB, DIV CHEM & ANALYT SCI, OAK RIDGE, TN 37831 USA. NR 35 TC 339 Z9 344 U1 4 U2 36 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0003-2700 J9 ANAL CHEM JI Anal. Chem. PD MAR 15 PY 1997 VL 69 IS 6 BP 1174 EP 1178 DI 10.1021/ac9610671 PG 5 WC Chemistry, Analytical SC Chemistry GA WM550 UT WOS:A1997WM55000030 ER PT J AU Barth, RF Yang, WL Rotaru, JH Moeschberger, ML Joel, DD Nawrocky, MM Goodman, JH Soloway, AH AF Barth, RF Yang, WL Rotaru, JH Moeschberger, ML Joel, DD Nawrocky, MM Goodman, JH Soloway, AH TI Boron neutron capture therapy of brain tumors: Enhanced survival following intracarotid injection of either sodium borocaptate or boronophenylalanine with or without blood-brain barrier disruption SO CANCER RESEARCH LA English DT Article ID RAT-BRAIN; MALIGNANT GLIOMAS; CHOROID-PLEXUS; CHEMOTHERAPY; DAMAGE; PHARMACOKINETICS; PERMEABILITY; IRRADIATION; DELIVERY; INFUSION AB The purpose of the present study was to determine whether the efficacy of boron neutron capture therapy could be enhanced by means of intracarotid (i.c.) injection of sodium borocaptate (BSH) or boronophenylalanine (BPA) with or without blood-brain barrier disruption (BBB-D). For biodistribution studies, F98 glioma-bearing rats were injected i.v. or i.c. with either BSH (30 mg of boron/kg of body weight) or BPA (24 mg of boron/kg of body weight) with or without mannitol-induced, hyperosmotic BBB-D and killed 2.5 h later, The highest tumor boron concentrations for BSH and BPA were attained following i.c. injection with BBB-D (48.6 and 94.0 mu g/g, respectively) compared to i.c. (30.8 and 42.7 mu g/g) and i.v. injection (12.9 and 20.8 mu g). Using the same doses of BSH and BPA, therapy experiments were initiated 14 days after intracerebral implantation of F98 glioma cells. Animals were irradiated 2.5 h after i.v. or i.c. administration of the capture agent with or without BBB-D using a collimated beam of thermal neutrons at the Brookhaven Medical Research Reactor. The median survival times of rats given BSH or BPA i.c. were 52 and 69 days, respectively, for rats with BBB-D; 39 and 48 days for rats without BBB-D; 33 and 37 days for i.v. injected rats; 29 days for irradiated controls; and 24 days for untreated controls. i.e injection of either BSH or BPA resulted in highly significant enhancement (P = 0.01 and P = 0.0002, respectively) of survival times compared to i.v. injection, and this was further augmented by BBB-D (P = 0.02 and P = 0.04, respectively) compared to i.e injection. Normal brain tissue tolerance studies were carried out with non-tumor-bearing rats, which were treated in the same way as tumor-bearing animals, One year after irradiation, the brains of these animals showed only minimal radiation-induced changes in the choroid plexus, but no differences were discernible between irradiated controls and those that had BBB-D followed by i.c. injection of either BSH or BPA. Our data clearly show that the route of administration, as well as BBB-D, can enhance the uptake of BSH and BPA, and, subsequently, the efficacy of boron neutron capture therapy. C1 OHIO STATE UNIV, SCH PUBL HLTH, DIV BIOSTAT & EPIDEMIOL, COLUMBUS, OH 43210 USA. OHIO STATE UNIV, DIV NEUROSURG, COLUMBUS, OH 43210 USA. OHIO STATE UNIV, COLL PHARM, COLUMBUS, OH 43210 USA. BROOKHAVEN NATL LAB, DEPT MED, UPTON, NY 11973 USA. RP Barth, RF (reprint author), OHIO STATE UNIV, DEPT PATHOL, 165 HAMILTON HALL, 1645 NEIL AVE, COLUMBUS, OH 43210 USA. NR 49 TC 112 Z9 114 U1 0 U2 2 PU AMER ASSOC CANCER RESEARCH PI PHILADELPHIA PA 615 CHESTNUT ST, 17TH FLOOR, PHILADELPHIA, PA 19106-4404 USA SN 0008-5472 J9 CANCER RES JI Cancer Res. PD MAR 15 PY 1997 VL 57 IS 6 BP 1129 EP 1136 PG 8 WC Oncology SC Oncology GA WN564 UT WOS:A1997WN56400025 PM 9067283 ER PT J AU Gadbois, DM Bradbury, EM Lehnert, BE AF Gadbois, DM Bradbury, EM Lehnert, BE TI Control of radiation-induced G(1) arrest by cell-substratum interactions SO CANCER RESEARCH LA English DT Article ID HUMAN FIBROBLASTS; EXTRACELLULAR-MATRIX; SIGNAL-TRANSDUCTION; P53 PROTEIN; DNA-DAMAGE; ADHESION; KINASE; DIFFERENTIATION; INHIBITION; BINDING AB Ionizing radiation has been reported to cause an irreversible, senescence-like G(1) arrest in human fibroblasts, which is accompanied by elevated p21(CIP1) amounts. In further support of a senescence-like arrest, we show that expression of p53 and cyclin D1 is elevated in gamma-irradiated, arrested fibroblasts. However, we also demonstrate that the arrest is reversible if the irradiated cells are trypsinized and replated, which may implicate cellular-extracellular matrix interactions in cell cycle control after irradiation. C1 UNIV CALIF DAVIS,DEPT MED BIOL CHEM,DAVIS,CA 95616. RP Gadbois, DM (reprint author), LOS ALAMOS NATL LAB,DIV LIFE SCI,CELL & MOL BIOL GRP,MS M888,LOS ALAMOS,NM 87545, USA. NR 27 TC 38 Z9 40 U1 0 U2 0 PU AMER ASSOC CANCER RESEARCH PI PHILADELPHIA PA PUBLIC LEDGER BLDG, SUITE 816, 150 S. INDEPENDENCE MALL W., PHILADELPHIA, PA 19106 SN 0008-5472 J9 CANCER RES JI Cancer Res. PD MAR 15 PY 1997 VL 57 IS 6 BP 1151 EP 1156 PG 6 WC Oncology SC Oncology GA WN564 UT WOS:A1997WN56400028 PM 9067286 ER PT J AU StrongGunderson, JM Palumbo, AV AF StrongGunderson, JM Palumbo, AV TI Laboratory studies identify a colloidal groundwater tracer: Implications for bioremediation SO FEMS MICROBIOLOGY LETTERS LA English DT Article DE sodium chloride; groundwater flow; fracture flow; ice nucleating active bacterium; microsphere bead ID ICE NUCLEATION ACTIVITY; BACTERIA; PSEUDOMONAS AB We have identified and tested a new colloidal tracer for use in hazardous waste site characterization and other environmental applications. The tracer is primarily composed of the dead ice nucleating active (INA) bacterium Pseudomonas syringae. Assay conditions are simple and based on the observation of the freezing behavior of 10 mu l solution volumes. Under specific assay conditions (-5 to -7 degrees C) these drops freeze only if the tracer is present, The results are available within 3 min of sample collection thus, providing near real-time results. The tracer detection limits are in the range of ng/l, it is stable over a pH range of 2-11, and maintains its high activity in the presence of a variety of contaminant compounds. In a simple column experiment this colloid tracer eluted just prior to NaCl with little or no tailing. RP StrongGunderson, JM (reprint author), OAK RIDGE NATL LAB,POB 2008,OAK RIDGE,TN 37831, USA. RI Palumbo, Anthony/A-4764-2011 OI Palumbo, Anthony/0000-0002-1102-3975 NR 20 TC 8 Z9 8 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0378-1097 J9 FEMS MICROBIOL LETT JI FEMS Microbiol. Lett. PD MAR 15 PY 1997 VL 148 IS 2 BP 131 EP 135 DI 10.1016/S0378-1097(96)00539-3 PG 5 WC Microbiology SC Microbiology GA WP017 UT WOS:A1997WP01700003 ER PT J AU Dai, S Toth, LM Hayes, GR Peterson, JR AF Dai, S Toth, LM Hayes, GR Peterson, JR TI Spectroscopic investigation of effect of Lewis basicity on the valent-state stability of an uranium(V) chloride complex in ambient temperature melts SO INORGANICA CHIMICA ACTA LA English DT Article DE Lewis basicity; uranium complexes; chloride complexes ID ELECTROCHEMISTRY; CHLOROALUMINATE; SALTS AB The visible and NIR absorption spectrum of uranium(V) chloride in room temperature acidic melts has been measured. This spectrum was obtained by the direct dissolution of an uranium(V) chloride compound into a room temperature melt. Changing the acidic melt to a basic melt by adding EMIC caused the gradual disappearance of the U(V) spectrum and the concomitant appearance of a new set of bands. The absorption spectrum recorded in the basic melt of composition AlCl3:EMIC = 45:55 is identical to that from the uranium(IV) hexachloride complex in the same melt. This conversion of U(V) to U(IV) establishes that the uranium(V) chloride complex underwent a reduction reaction to form the uranium(IV) hexachloride complex. The stoichiometric ratio of U(total):U(IV) in this redox process was experimentally determined to be 1.00:1.00. The standard deviation for this ratio is 0.02. This suggests that the formation of uranium(IV) hexachloride in the basic melt is not via the disproportionation reaction of U(V). C1 UNIV TENNESSEE,DEPT CHEM,KNOXVILLE,TN 37996. OAK RIDGE NATL LAB,TRANSURANIUM RES LAB,OAK RIDGE,TN 37831. RP Dai, S (reprint author), OAK RIDGE NATL LAB,DIV CHEM TECHNOL,POB 2008,OAK RIDGE,TN 37831, USA. RI Dai, Sheng/K-8411-2015 OI Dai, Sheng/0000-0002-8046-3931 NR 17 TC 17 Z9 17 U1 0 U2 7 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0020-1693 J9 INORG CHIM ACTA JI Inorg. Chim. Acta PD MAR 15 PY 1997 VL 256 IS 1 BP 143 EP 145 DI 10.1016/S0020-1693(96)05416-3 PG 3 WC Chemistry, Inorganic & Nuclear SC Chemistry GA WU737 UT WOS:A1997WU73700020 ER EF