FN Thomson Reuters Web of Science™ VR 1.0 PT J AU Vaidya, RU Bartlett, AH Kung, H Butt, DP AF Vaidya, RU Bartlett, AH Kung, H Butt, DP TI Joining of MoSi2 to itself and reactions with aluminium interlayers SO JOURNAL OF MATERIALS SCIENCE LETTERS LA English DT Article ID ADDITIONS C1 Univ Calif Los Alamos Natl Lab, Div Mat Sci & Technol, Los Alamos, NM 87545 USA. RP Vaidya, RU (reprint author), Univ Calif Los Alamos Natl Lab, Div Mat Sci & Technol, POB 1663, Los Alamos, NM 87545 USA. RI Butt, Darryl/B-7480-2008 OI Butt, Darryl/0000-0003-4501-8864 NR 14 TC 1 Z9 2 U1 0 U2 0 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0261-8028 J9 J MATER SCI LETT JI J. Mater. Sci. Lett. PD MAY 1 PY 1998 VL 17 IS 9 BP 777 EP 780 DI 10.1023/A:1006691718653 PG 4 WC Materials Science, Multidisciplinary SC Materials Science GA 170YX UT WOS:000078835900019 ER PT J AU Kitayama, M Glaeser, AM AF Kitayama, M Glaeser, AM TI The kinetics of pore shape evolution in alumina SO JOURNAL OF MATERIALS SYNTHESIS AND PROCESSING LA English DT Article DE alumina; surface; kinetics; diffusion; SALK ID SURFACE-DIFFUSION; PARTICLES; SAPPHIRE AB The kinetics of shape evolution of a completely faceted crystal/internal void by surface diffusion was modeled. Arrays of micron-sized cavities were generated in sapphire substrates with known surface orientations using microlithography and ion beam etching and converted to internal intragranular pores of nonequilibrium shape by diffusion bonding of the etched substrate to an identical-orientation unetched sapphire substrate. Pore shape evolution rates during high-temperature anneals were monitored and found to be highly sensitive to the orientation of the substrate surface. The observed evolution rates were compared with the predictions of the kinetic model using diffusivity values for alumina that span the range from the highest to the lowest diffusion constants reported in the literature. The comparison suggests that surface-attachment-limited kinetics (SALK) play a major role in surface mass transport on stable low-index planes of alumina. C1 Univ Calif Berkeley, Dept Mat Sci & Mineral Engn, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Ctr Adv Mat, Berkeley, CA 94720 USA. RP Kitayama, M (reprint author), Fine Ceram Res Assoc, Synergy Ceram Lab, Kita Ku, 1-1 Hirate-cho, Nagoya, Aichi 462, Japan. NR 15 TC 3 Z9 3 U1 0 U2 4 PU PLENUM PUBL CORP PI NEW YORK PA CONSULTANTS BUREAU, 233 SPRING ST, NEW YORK, NY 10013 USA SN 1064-7562 J9 J MATER SYNTH PROCES JI J. Mater. Synth. Process PD MAY PY 1998 VL 6 IS 3 BP 161 EP 167 DI 10.1023/A:1022665418505 PG 7 WC Materials Science, Multidisciplinary SC Materials Science GA 156GR UT WOS:000077993700003 ER PT J AU Jacobs, PW Somorjai, GA AF Jacobs, PW Somorjai, GA TI Conversion of heterogeneous catalysis from art to science: the surface science of heterogeneous catalysis SO JOURNAL OF MOLECULAR CATALYSIS A-CHEMICAL LA English DT Article DE model catalysts; surface science; heterogeneous catalysis ID SUPPORTED PALLADIUM CATALYSTS; ELECTRON-BEAM LITHOGRAPHY; SINGLE-CRYSTAL SURFACES; AMMONIA-SYNTHESIS; PARTIAL OXIDATION; MODEL CATALYSTS; THIN-FILMS; HYDROGENATION; ADSORPTION; CO AB Direct combination of high pressure reaction studies with molecular level surface characterization of model catalysts has made possible the development of concepts to describe and to explain phenomena that occur during heterogeneous catalysis. These phenomena include structure sensitivity, surface reconstruction, inert chemisorbed overlayers present under reaction conditions, and interaction between the metal and the oxide support. The catalytic behavior of model systems and the roles of their different components have been investigated and explained in terms of some of these concepts. (C) 1998 Elsevier Science B.V. C1 Lawrence Berkeley Natl Lab, Div Mat Sci, Berkeley, CA 94720 USA. RP Somorjai, GA (reprint author), Lawrence Berkeley Natl Lab, Div Mat Sci, Berkeley, CA 94720 USA. NR 55 TC 31 Z9 31 U1 2 U2 14 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 1381-1169 J9 J MOL CATAL A-CHEM JI J. Mol. Catal. A-Chem. PD MAY 1 PY 1998 VL 131 IS 1-3 BP 5 EP 18 DI 10.1016/S1381-1169(97)00252-5 PG 14 WC Chemistry, Physical SC Chemistry GA ZT724 UT WOS:000074118500003 ER PT J AU Cremer, PS Su, XC Somorjai, GA Shen, YR AF Cremer, PS Su, XC Somorjai, GA Shen, YR TI High pressure catalytic processes studied by infrared-visible sum frequency generation SO JOURNAL OF MOLECULAR CATALYSIS A-CHEMICAL LA English DT Article DE sum frequency generation; spectroscopy; chromatography ID REFLECTION-ABSORPTION-SPECTROSCOPY; REACTION-RATE OSCILLATIONS; TIME SAMPLING ELECTRONICS; ETHYLENE HYDROGENATION; CO OXIDATION; PT/SIO2 CATALYST; BONDED ETHYLENE; LINEAR BUTENES; IR-SPECTRA; PT(111) AB The recent development of infrared-visible sum frequency generation (SFG), a surface-specific Vibrational spectroscopy, has helped bridge the pressure gap between studies of heterogeneous catalysis under high vacuum and atmospheric pressure. This is achieved by in situ monitoring of surface species at high pressure via their SFG vibrational spectra and correlating the results with the simultaneously measured reaction rate using gas chromatography. Examples of systems studied include olefin hydrogenation and carbon monoxide oxidation over the (111) crystalline face of platinum. In these examples, the studies succeed in revealing the molecular details of the surface reactions. Identification of key intermediates and their concentrations has made it possible for the first time to calculate turn over rates per active surface species rather than just per exposed surface metal atom. In all cases, the key intermediate of the reaction is not detectable on the surface in UHV under similar temperatures. (C) 1998 Elsevier Science B.V. C1 Lawrence Berkeley Natl Lab, Div Mat Sci, Berkeley, CA 94550 USA. Stanford Univ, Dept Chem, Stanford, CA 94305 USA. Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. RP Shen, YR (reprint author), Lawrence Berkeley Natl Lab, Div Mat Sci, Berkeley, CA 94550 USA. NR 42 TC 60 Z9 60 U1 1 U2 13 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 1381-1169 J9 J MOL CATAL A-CHEM JI J. Mol. Catal. A-Chem. PD MAY 1 PY 1998 VL 131 IS 1-3 BP 225 EP 241 DI 10.1016/S1381-1169(97)00268-9 PG 17 WC Chemistry, Physical SC Chemistry GA ZT724 UT WOS:000074118500019 ER PT J AU Van Hove, MA Somorjai, GA AF Van Hove, MA Somorjai, GA TI Selected molecular surface structures determined by modern low-energy electron diffraction SO JOURNAL OF MOLECULAR CATALYSIS A-CHEMICAL LA English DT Article DE low-energy electron diffraction; adsorption site; adsorbate orientation; molecular distortion ID LEED-IV DETERMINATION; DYNAMICAL LEED; TENSOR LEED; SIMULTANEOUS BRIDGE; INTENSITY ANALYSIS; METAL-SURFACES; CO; ADSORPTION; RH(111); RU(0001) AB This article surveys a series of structural results obtained for the adsorption of small molecules (from CO to benzene) on the closest-packed metal surfaces by low-energy electron diffraction (LEED). Most of these results were obtained by detailed fitting of many structural parameters, primarily with automated tensor LEED. We discuss mainly qualitative aspects: adsorption sites, adsorbate orientation, molecular distortions and adsorbate-induced relaxations. Cases of special interest include: CO and NO monolayers adsorbed on metal surfaces, which require a revision of adsorption site assignments based on vibrational frequencies; various coadsorption structures exhibiting site changes due to the electron donor vs, acceptor character of the coadsorbates; intact di-sigma ethylene adsorbed in a disordered and asymmetrical manner on Pt(111); intact acetylene on MgO(100), the first molecular and also first physisorbed adsorption structure determined in detail on an oxide surface; and the surface of an ultra-thin ice film, exhibiting unusually large vibration amplitudes of the outermost molecules. (C) 1998 Elsevier Science B.V. C1 Lawrence Berkeley Natl Lab, Div Mat Sci, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. RP Van Hove, MA (reprint author), Lawrence Berkeley Natl Lab, Div Mat Sci, Mailstop 66-200, Berkeley, CA 94720 USA. EM vanhove@lbl.gov RI Van Hove, Michel/A-9862-2008 OI Van Hove, Michel/0000-0002-8898-6921 NR 53 TC 20 Z9 20 U1 1 U2 8 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 1381-1169 J9 J MOL CATAL A-CHEM JI J. Mol. Catal. A-Chem. PD MAY 1 PY 1998 VL 131 IS 1-3 BP 243 EP 257 DI 10.1016/S1381-1169(97)00269-0 PG 15 WC Chemistry, Physical SC Chemistry GA ZT724 UT WOS:000074118500020 ER PT J AU Jenks, CJ Thiel, PA AF Jenks, CJ Thiel, PA TI Comments on quasicrystals and their potential use as catalysts SO JOURNAL OF MOLECULAR CATALYSIS A-CHEMICAL LA English DT Article DE quasicrystals; catalyst; Penrose tiling model ID MARAGING STAINLESS-STEEL; SINGLE-QUASI-CRYSTAL; MN ICOSAHEDRAL PHASE; ELECTRICAL-RESISTIVITY; ALLOYS; SURFACE; DIFFUSIVITY; COATINGS; GRAIN; SIZE AB Recent findings suggest that quasicrystalline materials may make better catalysts than their crystalline counterparts. On the other hand, detailed surface science studies suggest that the surfaces of Al-based quasicrystals behave as if they are chemically similar to pure Al. In this paper, we discuss these results along with the unique thermodynamic and electronic properties of quasicrystals which could affect their catalytic nature. (C) 1998 Elsevier Science B.V. C1 Iowa State Univ, Ames Lab, Ames, IA 50011 USA. Iowa State Univ, Dept Chem, Ames, IA 50011 USA. RP Jenks, CJ (reprint author), Iowa State Univ, Ames Lab, Ames, IA 50011 USA. NR 55 TC 31 Z9 33 U1 0 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 1381-1169 J9 J MOL CATAL A-CHEM JI J. Mol. Catal. A-Chem. PD MAY 1 PY 1998 VL 131 IS 1-3 BP 301 EP 306 DI 10.1016/S1381-1169(97)00272-0 PG 6 WC Chemistry, Physical SC Chemistry GA ZT724 UT WOS:000074118500023 ER PT J AU Aziz, T Peress, NS Capala, J Coderre, JA Diaz, A Chanana, AD AF Aziz, T Peress, NS Capala, J Coderre, JA Diaz, A Chanana, AD TI Postmortem neuropathological features secondary to boron capture neutron therapy (BNCT) for glioblastoma multiforme (GBM). SO JOURNAL OF NEUROPATHOLOGY AND EXPERIMENTAL NEUROLOGY LA English DT Meeting Abstract C1 SUNY Stony Brook, Hlth Sci Ctr, Stony Brook, NY 11794 USA. Brookhaven Natl Lab, Upton, NY 11973 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER ASSN NEUROPATHOLOGISTS INC PI LAWRENCE PA 1041 NEW HAMPSHIRE ST, LAWRENCE, KS 66044 USA SN 0022-3069 J9 J NEUROPATH EXP NEUR JI J. Neuropathol. Exp. Neurol. PD MAY PY 1998 VL 57 IS 5 MA 18 BP 473 EP 473 DI 10.1097/00005072-199805000-00031 PG 1 WC Clinical Neurology; Neurosciences; Pathology SC Neurosciences & Neurology; Pathology GA ZN115 UT WOS:000073611400030 ER PT J AU Crandall, RS Liu, X Iwaniczko, E AF Crandall, RS Liu, X Iwaniczko, E TI Recent developments in hot wire amorphous silicon SO JOURNAL OF NON-CRYSTALLINE SOLIDS LA English DT Article; Proceedings Paper CT 17th International Conference on Amorphous and Microcrystalline Semiconductors - Science and Technology (ICAMS 17) CY AUG 25-29, 1997 CL BUDAPEST, HUNGARY DE amorphous silicon; internal friction; chemical vapor deposition ID A-SI-H; CHEMICAL-VAPOR-DEPOSITION; MICROCRYSTALLINE SILICON; INFRARED-ABSORPTION; LOW-TEMPERATURE; FILMS; QUALITY AB We present measurements of low temperature internal friction (Q(-1)) of amorphous silicon (a-Si) films designed to probe how their structure and formation affect low temperature vibrational properties. All a-Si films, whether produced by e-beam evaporation, sputtering, Si self-ion implantation, or chemical vapor deposition (CVD) show the well-known temperature-independent plateau (Q(0)(-1)) common to all amorphous solids. For hydrogenated amorphous silicon (a-Si:H) with about 1 at.% H produced by hot wire CVD; however, the internal friction is nearly three orders of magnitude less than any known amorphous material. For this material we find that Q(-1) depends on H concentration (C(H)), and on deposition conditions. For C(H) > 2 at.%, both a peak and a sharp transitional feature appear in Q(-1) between 5 and 40 K. We identify the feature as H(2), presumably in microvoids, undergoing a phase transition at the freezing point. (C) 1998 Elsevier Science B.V. All rights reserved. C1 Natl Renewable Energy Lab, Golden, CO 80401 USA. Cornell Univ, Atom & Solid State Phys Lab, Ithaca, NY 14853 USA. RP Crandall, RS (reprint author), Natl Renewable Energy Lab, 1617 Cole Blvd, Golden, CO 80401 USA. EM rsc@nrel.gov NR 29 TC 13 Z9 15 U1 0 U2 3 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 MAY PY 1998 VL 227 BP 23 EP 28 DI 10.1016/S0022-3093(98)00327-5 PN A PG 6 WC Materials Science, Ceramics; Materials Science, Multidisciplinary SC Materials Science GA ZY635 UT WOS:000074643400005 ER PT J AU Unold, T Reedy, RC Mahan, AH AF Unold, T Reedy, RC Mahan, AH TI Defects in hot-wire deposited amorphous silicon: results from electron spin resonance SO JOURNAL OF NON-CRYSTALLINE SOLIDS LA English DT Article; Proceedings Paper CT 17th International Conference on Amorphous and Microcrystalline Semiconductors - Science and Technology (ICAMS 17) CY AUG 25-29, 1997 CL BUDAPEST, HUNGARY DE hot-wire; amorphous silicon; spin ID SURFACE AB A series of hot-wire deposited amorphous silicon films with hydrogen content varying between 0.5 and 17 at.% has been studied systematically with different experimental techniques. Steady-state photocarrier grating measurements on the samples indicate excellent ambipolar diffusion lengths even for films with smaller hydrogen contents. Sub-bandgap absorption indicates low defect densities for samples with a hydrogen content larger than 1 at.%. Electron spin resonance measurements on these samples, however, yield larger volume average spin densities than expected for the intermediate range of hydrogen content, 1 at.% < C(H) < 8 at.%. A series of samples with different thicknesses indicates a defective layer at one or both of the interfaces and a bulk spin density which agrees well with the optical absorption measurements. We believe that the defective layer is due to outdiffusion of hydrogen at the substrate interface during growth at temperatures, as indicated by secondary ion mass spectroscopy measurements on the same samples. (C) 1998 Elsevier Science B.V. All rights reserved. C1 Natl Renewable Energy Lab, Golden, CO 80401 USA. RP Unold, T (reprint author), Univ Oldenburg, Fachbereich Phys, D-26111 Oldenburg, Germany. EM unold@cip.physik.uni-oldenburg.de OI Unold, Thomas/0000-0002-5750-0693 NR 14 TC 2 Z9 2 U1 0 U2 2 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 MAY PY 1998 VL 227 BP 362 EP 366 DI 10.1016/S0022-3093(98)00227-0 PN A PG 5 WC Materials Science, Ceramics; Materials Science, Multidisciplinary SC Materials Science GA ZY635 UT WOS:000074643400074 ER PT J AU Liu, X Pohl, RO Asher, S Crandall, RS AF Liu, X Pohl, RO Asher, S Crandall, RS TI Contamination of silicon during ion-implantation and annealing SO JOURNAL OF NON-CRYSTALLINE SOLIDS LA English DT Article; Proceedings Paper CT 17th International Conference on Amorphous and Microcrystalline Semiconductors - Science and Technology (ICAMS 17) CY AUG 25-29, 1997 CL BUDAPEST, HUNGARY DE contamination; silicon; ion-implantation and annealing AB Low temperature (<10 K) internal friction measurements have revealed a contamination of silicon during annealing under all but the most careful conditions. A similar contamination occurs during ion-implantation. Boron was suspected as a likely contaminant, but can be clearly ruled out by combining low-temperature internal friction measurements and secondary ion mass spectroscopy. (C) 1998 Elsevier Science B.V. All rights reserved. C1 Cornell Univ, Dept Phys, Ithaca, NY 14853 USA. Natl Renewable Energy Lab, Golden, CO 80401 USA. RP Liu, X (reprint author), Cornell Univ, Dept Phys, Ithaca, NY 14853 USA. EM pohl@msc.cornell.edu NR 10 TC 5 Z9 5 U1 0 U2 0 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 MAY PY 1998 VL 227 BP 407 EP 410 DI 10.1016/S0022-3093(98)00175-6 PN A PG 4 WC Materials Science, Ceramics; Materials Science, Multidisciplinary SC Materials Science GA ZY635 UT WOS:000074643400084 ER PT J AU Darab, JG Li, H Vienna, JD AF Darab, JG Li, H Vienna, JD TI X-ray absorption spectroscopic investigation of the environment of cerium in glasses based on complex cerium alkali borosilicate compositions SO JOURNAL OF NON-CRYSTALLINE SOLIDS LA English DT Article ID OXIDATION-STATE AB We present the results of cerium L-III X-ray absorption near edge structure (XANES) studies of two series (-I and -II) of alkali boro-aluminosilicate based glasses prepared from compositions containing different amounts of CeO2 and P2O5, and melted at a variety of temperatures and redox conditions. Model XANES spectra for Ce3+ in the glass, Ce4+ in the glass, and crystalline CeO2, were used to fit the Ce L-III XANES spectra obtained from the glasses. This analysis allowed both the [Ce4+]/[Ce-total] ratio and the distribution of Ce environments to be determined for each glass. The [Ce4+]/[Ce-total] ratios, which varied from 0.00 to 0.58, determined independently by XANES spectroscopy were found to have a correlation, r > 0.9, with those previously obtained using wet chemical methods. Furthermore, using this method, these two series of glasses, which differed in the amounts of BaO, Bi2O3, SnO2, and ZrO2, had different distributions in their cerium environments. The Ce L-III XANES spectra obtained from series II glasses (1.0 wt% BaO, 1.0 wt% Bi2O3, no SnO2, and 1.0 wt% ZrO2) melted at 1350 degrees C were able to be fit using only Ce-glass(3+) and Ce-glass(4+) environments; whereas, those from series I glasses (2.7 wt% SnO2, no BaO or Bi2O3, and 5.1 wt% ZrO2) melted at 1120 degrees C could only be fit when an additional Ce-CeO2(4+) component was included, confirming the previous assessment that the series I glasses exhibited CeO2 related heterogeneities. (C) 1998 Elsevier Science B.V. All rights reserved. C1 Pacific NW Natl Lab, Richland, WA 99352 USA. RP Darab, JG (reprint author), Pacific NW Natl Lab, POB 999, Richland, WA 99352 USA. EM jg_darab@pnl.gov NR 20 TC 19 Z9 19 U1 1 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 MAY PY 1998 VL 226 IS 1-2 BP 162 EP 174 DI 10.1016/S0022-3093(98)00369-X PG 13 WC Materials Science, Ceramics; Materials Science, Multidisciplinary SC Materials Science GA ZW582 UT WOS:000074426100021 ER PT J AU Allen, TR Busby, JT Was, GS Kenik, EA AF Allen, TR Busby, JT Was, GS Kenik, EA TI On the mechanism of radiation-induced segregation in austenitic Fe-Cr-Ni alloys SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article ID GRAIN-BOUNDARY SEGREGATION; STAINLESS-STEELS; ELECTRON-IRRADIATION; PROTON IRRADIATION; SOLID-SOLUTIONS; SELF-DIFFUSION; DEPENDENCE; BINARY AB The relative importance of the vacancy and interstitial contributions to radiation-induced segregation (RIS) in Fe-Cr-Ni alloys is studied to better understand the mechanisms causing changes in grain boundary composition and to improve the capability to predict RIS in austenitic Fe-Cr-Ni alloys. The primary driving mechanism for segregation in Fe-Cr-Ni alloys is shown to be the inverse KirkendaIl (IK) mechanism. specifically the coupling between alloying elements and the vacancy flux. To study grain boundary segregation. seven alloys were irradiated with 3.2 MeV protons at temperatures from 200 degrees C to 600 degrees C and to doses from 0.1 to 3 dpa. Grain boundary composition were measured using both Auger electron spectroscopy (AES) and scanning transmission electron microscopy with energy dispersive X-ray spectroscopy (STEM/EDS). Grain boundary compositions were compared to model predictions that assume segregation was driven either by preferential interaction of solute atoms with the vacancy flux alone or in combination with binding of undersized solutes to the interstitial Flux. Calculations that assume the segregation is caused by preferential interaction of solute atoms with the vacancy flux generally followed the trends of the segregation measurements. However, the inclusion of interstitial binding to the IK model causes poor agreement between model predictions and segregation measurements, resulting in seven overprediction of Ni enrichment and Fe depletion. Comparisons of segregation models with RIS in alloys irradiated with neutrons also show that preferential interaction of solutes with the vacancy flux sufficiently describes segregation in Fe-Cr-Ni alloys. (C) 1998 Elsevier Science B.V. All rights reserved. C1 Univ Michigan, Dept Nucl Engn & Radiol Sci, Ann Arbor, MI 48109 USA. Oak Ridge Natl Lab, Div Met & Ceram, Oak Ridge, TN 37831 USA. RP Allen, TR (reprint author), Argonne Natl Lab W, POB 2528, Idaho Falls, ID 83403 USA. OI Allen, Todd/0000-0002-2372-7259 NR 41 TC 67 Z9 68 U1 3 U2 23 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 MAY PY 1998 VL 255 IS 1 BP 44 EP 58 DI 10.1016/S0022-3115(98)00010-5 PG 15 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA ZT913 UT WOS:000074140600005 ER PT J AU Ding, YS Fowler, JS Volkow, ND Logan, J Dewey, SL Carroll, FI Kuhar, MJ AF Ding, YS Fowler, JS Volkow, ND Logan, J Dewey, SL Carroll, FI Kuhar, MJ TI Dopamine D-2 receptor-mediated regulation of central cholinergic activity: PET studies with [F-18]fluoroepibatidine. SO JOURNAL OF NUCLEAR MEDICINE LA English DT Meeting Abstract C1 Brookhaven Natl Lab, Dept Chem, Upton, NY 11973 USA. Brookhaven Natl Lab, Dept Med, Upton, NY 11973 USA. Emory Univ, Atlanta, GA 30322 USA. Res Triangle Inst, Res Triangle Pk, NC 27709 USA. NR 0 TC 2 Z9 2 U1 0 U2 0 PU SOC NUCLEAR MEDICINE INC PI RESTON PA 1850 SAMUEL MORSE DR, RESTON, VA 20190-5316 USA SN 0161-5505 J9 J NUCL MED JI J. Nucl. Med. PD MAY PY 1998 VL 39 IS 5 SU S MA 36 BP 12P EP 12P PG 1 WC Radiology, Nuclear Medicine & Medical Imaging SC Radiology, Nuclear Medicine & Medical Imaging GA ZM639 UT WOS:000073560300037 ER PT J AU Gatley, SJ Gifford, AN Volkow, ND Makriyannis, A AF Gatley, SJ Gifford, AN Volkow, ND Makriyannis, A TI On imaging neurotransmitter receptor occupancies: The brain cannabinoid CB1 receptor system. SO JOURNAL OF NUCLEAR MEDICINE LA English DT Meeting Abstract C1 Univ Connecticut, Storrs, CT USA. Brookhaven Natl Lab, Upton, NY 11973 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU SOC NUCLEAR MEDICINE INC PI RESTON PA 1850 SAMUEL MORSE DR, RESTON, VA 20190-5316 USA SN 0161-5505 J9 J NUCL MED JI J. Nucl. Med. PD MAY PY 1998 VL 39 IS 5 SU S MA 38 BP 12P EP 12P PG 1 WC Radiology, Nuclear Medicine & Medical Imaging SC Radiology, Nuclear Medicine & Medical Imaging GA ZM639 UT WOS:000073560300039 ER PT J AU Volkow, ND Wang, GJ Fowler, JS Franceski, D Logan, J Gatley, SJ Dewey, SL Wong, C AF Volkow, ND Wang, GJ Fowler, JS Franceski, D Logan, J Gatley, SJ Dewey, SL Wong, C TI Dose response to methylphenidate-induced changes in [C-11]raclopride binding. SO JOURNAL OF NUCLEAR MEDICINE LA English DT Meeting Abstract C1 Brookhaven Natl Lab, Upton, NY 11973 USA. SUNY Stony Brook, Stony Brook, NY 11794 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU SOC NUCLEAR MEDICINE INC PI RESTON PA 1850 SAMUEL MORSE DR, RESTON, VA 20190-5316 USA SN 0161-5505 J9 J NUCL MED JI J. Nucl. Med. PD MAY PY 1998 VL 39 IS 5 SU S MA 39 BP 12P EP 13P PG 2 WC Radiology, Nuclear Medicine & Medical Imaging SC Radiology, Nuclear Medicine & Medical Imaging GA ZM639 UT WOS:000073560300040 ER PT J AU Fowler, JS Volkow, ND Logan, J Pappas, N Gatley, SJ AF Fowler, JS Volkow, ND Logan, J Pappas, N Gatley, SJ TI An acute dose of nicotine does not inhibit baboon brain MAO B in vivo SO JOURNAL OF NUCLEAR MEDICINE LA English DT Meeting Abstract C1 Brookhaven Natl Lab, Upton, NY 11973 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU SOC NUCLEAR MEDICINE INC PI RESTON PA 1850 SAMUEL MORSE DR, RESTON, VA 20190-5316 USA SN 0161-5505 J9 J NUCL MED JI J. Nucl. Med. PD MAY PY 1998 VL 39 IS 5 SU S MA 40 BP 13P EP 13P PG 1 WC Radiology, Nuclear Medicine & Medical Imaging SC Radiology, Nuclear Medicine & Medical Imaging GA ZM639 UT WOS:000073560300041 ER PT J AU Lim, JK Riese, DJ Negash, K Hawkins, RA VanBrocklin, HF AF Lim, JK Riese, DJ Negash, K Hawkins, RA VanBrocklin, HF TI Synthesis and in vitro evaluation of epidermal growth factor receptor tyrosine kinase inhibitors. SO JOURNAL OF NUCLEAR MEDICINE LA English DT Meeting Abstract C1 Lawrence Berkeley Lab, Berkeley, CA USA. Purdue Univ, W Lafayette, IN 47907 USA. Univ Calif San Francisco, San Francisco, CA 94143 USA. NR 0 TC 2 Z9 2 U1 0 U2 0 PU SOC NUCLEAR MEDICINE INC PI RESTON PA 1850 SAMUEL MORSE DR, RESTON, VA 20190-5316 USA SN 0161-5505 J9 J NUCL MED JI J. Nucl. Med. PD MAY PY 1998 VL 39 IS 5 SU S MA 71 BP 20P EP 21P PG 2 WC Radiology, Nuclear Medicine & Medical Imaging SC Radiology, Nuclear Medicine & Medical Imaging GA ZM639 UT WOS:000073560300072 ER PT J AU Lash, TR AF Lash, TR TI Invited commentary - The department of energy's role in isotope availability for nuclear medicine research SO JOURNAL OF NUCLEAR MEDICINE LA English DT Editorial Material C1 US Dept Energy, Off Nucl Energy Sci & Technol, Washington, DC USA. RP Lash, TR (reprint author), US Dept Energy, Off Nucl Energy Sci & Technol, Washington, DC USA. NR 0 TC 1 Z9 1 U1 0 U2 0 PU SOC NUCLEAR MEDICINE INC PI RESTON PA 1850 SAMUEL MORSE DR, RESTON, VA 20190-5316 USA SN 0161-5505 J9 J NUCL MED JI J. Nucl. Med. PD MAY PY 1998 VL 39 IS 5 BP 22N EP + PG 2 WC Radiology, Nuclear Medicine & Medical Imaging SC Radiology, Nuclear Medicine & Medical Imaging GA ZL912 UT WOS:000073486000006 PM 9591567 ER PT J AU Telang, FW Volkow, ND Logan, J Fowler, JS Felder, C Levy, A Wong, C Wang, GJ AF Telang, FW Volkow, ND Logan, J Fowler, JS Felder, C Levy, A Wong, C Wang, GJ TI Distribution of cocaine in the human brain as assessed with averaged [11C]cocaine images. SO JOURNAL OF NUCLEAR MEDICINE LA English DT Meeting Abstract C1 Brookhaven Natl Lab, Upton, NY 11973 USA. SUNY Stony Brook, Stony Brook, NY 11794 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU SOC NUCLEAR MEDICINE INC PI RESTON PA 1850 SAMUEL MORSE DR, RESTON, VA 20190-5316 USA SN 0161-5505 J9 J NUCL MED JI J. Nucl. Med. PD MAY PY 1998 VL 39 IS 5 SU S MA 156 BP 42P EP 42P PG 1 WC Radiology, Nuclear Medicine & Medical Imaging SC Radiology, Nuclear Medicine & Medical Imaging GA ZM639 UT WOS:000073560300157 ER PT J AU Volkow, ND Wang, GJ Fowler, JS Logan, J Gatley, SJ Ding, YS Telang, F Wong, C Pappas, N AF Volkow, ND Wang, GJ Fowler, JS Logan, J Gatley, SJ Ding, YS Telang, F Wong, C Pappas, N TI Dopamine transporter occupancy by intravenous methylphenidate: Relationship to its reinforcing effects. SO JOURNAL OF NUCLEAR MEDICINE LA English DT Meeting Abstract C1 Brookhaven Natl Lab, Upton, NY 11973 USA. SUNY Stony Brook, Stony Brook, NY 11794 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU SOC NUCLEAR MEDICINE INC PI RESTON PA 1850 SAMUEL MORSE DR, RESTON, VA 20190-5316 USA SN 0161-5505 J9 J NUCL MED JI J. Nucl. Med. PD MAY PY 1998 VL 39 IS 5 SU S MA 159 BP 42P EP 42P PG 1 WC Radiology, Nuclear Medicine & Medical Imaging SC Radiology, Nuclear Medicine & Medical Imaging GA ZM639 UT WOS:000073560300160 ER PT J AU Volkow, ND Fowler, JS Wang, GJ Logan, J Gatley, SJ Ding, YS Pappas, N AF Volkow, ND Fowler, JS Wang, GJ Logan, J Gatley, SJ Ding, YS Pappas, N TI Oral methylphenidate induces significant levels of dopamine transporter occupancy. SO JOURNAL OF NUCLEAR MEDICINE LA English DT Meeting Abstract C1 Brookhaven Natl Lab, Upton, NY 11973 USA. SUNY Stony Brook, Stony Brook, NY 11794 USA. NR 0 TC 0 Z9 0 U1 1 U2 2 PU SOC NUCLEAR MEDICINE INC PI RESTON PA 1850 SAMUEL MORSE DR, RESTON, VA 20190-5316 USA SN 0161-5505 J9 J NUCL MED JI J. Nucl. Med. PD MAY PY 1998 VL 39 IS 5 SU S MA 160 BP 43P EP 43P PG 1 WC Radiology, Nuclear Medicine & Medical Imaging SC Radiology, Nuclear Medicine & Medical Imaging GA ZM639 UT WOS:000073560300161 ER PT J AU Knapp, FF Beets, AL Guhlke, S Gledd, KN Marboe, C Amols, H Weinberger, J AF Knapp, FF Beets, AL Guhlke, S Gledd, KN Marboe, C Amols, H Weinberger, J TI Rhenium-188 liquid-filled balloons effectively inhibit restenosis in a swine coronary overstretch model - A simple new method bridging nuclear medicine and interventional cardiology. SO JOURNAL OF NUCLEAR MEDICINE LA English DT Meeting Abstract C1 Oak Ridge Natl Lab, Oak Ridge, TN USA. Clin Nucl Med, Bonn, Germany. Columbia Univ, New York, NY USA. NR 0 TC 4 Z9 4 U1 0 U2 0 PU SOC NUCLEAR MEDICINE INC PI RESTON PA 1850 SAMUEL MORSE DR, RESTON, VA 20190-5316 USA SN 0161-5505 J9 J NUCL MED JI J. Nucl. Med. PD MAY PY 1998 VL 39 IS 5 SU S MA 181 BP 48P EP 48P PG 1 WC Radiology, Nuclear Medicine & Medical Imaging SC Radiology, Nuclear Medicine & Medical Imaging GA ZM639 UT WOS:000073560300181 ER PT J AU McPherson, DW Breeden, W Luo, H Beets, A Knapp, FF AF McPherson, DW Breeden, W Luo, H Beets, A Knapp, FF TI Resolution, radiolabeling and in vivo evaluation of the isomers of IPIP. An attractive ligand for imaging mAChR. SO JOURNAL OF NUCLEAR MEDICINE LA English DT Meeting Abstract C1 Oak Ridge Natl Lab, Nucl Med Grp, Oak Ridge, TN USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU SOC NUCLEAR MEDICINE INC PI RESTON PA 1850 SAMUEL MORSE DR, RESTON, VA 20190-5316 USA SN 0161-5505 J9 J NUCL MED JI J. Nucl. Med. PD MAY PY 1998 VL 39 IS 5 SU S MA 184 BP 49P EP 49P PG 1 WC Radiology, Nuclear Medicine & Medical Imaging SC Radiology, Nuclear Medicine & Medical Imaging GA ZM639 UT WOS:000073560300184 ER PT J AU Azmoodeh, M Morgan, AE Volkow, ND Fowler, JS Dewey, SL AF Azmoodeh, M Morgan, AE Volkow, ND Fowler, JS Dewey, SL TI Effects of chronic L-deprenyl treatment on cocaine-induced increases in nucleus accumbens (NACC) dopamine. SO JOURNAL OF NUCLEAR MEDICINE LA English DT Meeting Abstract C1 Brookhaven Natl Lab, Chem & Med Dept, Upton, NY 11973 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU SOC NUCLEAR MEDICINE INC PI RESTON PA 1850 SAMUEL MORSE DR, RESTON, VA 20190-5316 USA SN 0161-5505 J9 J NUCL MED JI J. Nucl. Med. PD MAY PY 1998 VL 39 IS 5 SU S MA 204 BP 54P EP 54P PG 1 WC Radiology, Nuclear Medicine & Medical Imaging SC Radiology, Nuclear Medicine & Medical Imaging GA ZM639 UT WOS:000073560300204 ER PT J AU Wang, GJ Volkow, ND Fowler, JS Logan, J Pappas, NR Wong, CT Netusil, N Hitzemann, RJ AF Wang, GJ Volkow, ND Fowler, JS Logan, J Pappas, NR Wong, CT Netusil, N Hitzemann, RJ TI Measures of endogenous dopamine competition with [C-11]raclopride in the human brain: Test-retest reproducibility. SO JOURNAL OF NUCLEAR MEDICINE LA English DT Meeting Abstract C1 Brookhaven Natl Lab, Upton, NY 11973 USA. SUNY Stony Brook, Stony Brook, NY 11794 USA. VA, Northport, NY USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU SOC NUCLEAR MEDICINE INC PI RESTON PA 1850 SAMUEL MORSE DR, RESTON, VA 20190-5316 USA SN 0161-5505 J9 J NUCL MED JI J. Nucl. Med. PD MAY PY 1998 VL 39 IS 5 SU S MA 207 BP 54P EP 54P PG 1 WC Radiology, Nuclear Medicine & Medical Imaging SC Radiology, Nuclear Medicine & Medical Imaging GA ZM639 UT WOS:000073560300207 ER PT J AU Yoriyaz, H Stabin, M AF Yoriyaz, H Stabin, M TI Use of MCNP 4B to calculate dose distributions in a voxelized phantom SO JOURNAL OF NUCLEAR MEDICINE LA English DT Meeting Abstract C1 IPEN, CNEN SP, Inst Pesquisas Energet & Nuvl, Sao Paulo, Brazil. Oak Ridge Inst Sci & Educ, Oak Ridge, TN USA. NR 0 TC 2 Z9 2 U1 0 U2 0 PU SOC NUCLEAR MEDICINE INC PI RESTON PA 1850 SAMUEL MORSE DR, RESTON, VA 20190-5316 USA SN 0161-5505 J9 J NUCL MED JI J. Nucl. Med. PD MAY PY 1998 VL 39 IS 5 SU S MA 323 BP 83P EP 83P PG 1 WC Radiology, Nuclear Medicine & Medical Imaging SC Radiology, Nuclear Medicine & Medical Imaging GA ZM639 UT WOS:000073560300323 ER PT J AU Kotzerke, J Rentschler, M Glatting, G Schneider, E Knapp, FF Reske, SN AF Kotzerke, J Rentschler, M Glatting, G Schneider, E Knapp, FF Reske, SN TI Radiation dose measurements of a balloon catheter filled with liquid Re-188 by means of a TLD-system. SO JOURNAL OF NUCLEAR MEDICINE LA English DT Meeting Abstract C1 Univ Hosp Ulm, Dept Nucl Med, Ulm, Germany. Univ Hosp Ulm, Dept Radiat Therapy, Ulm, Germany. Oak Ridge Natl Lab, Nucl Med Grp, Oak Ridge, TN USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU SOC NUCLEAR MEDICINE INC PI RESTON PA 1850 SAMUEL MORSE DR, RESTON, VA 20190-5316 USA SN 0161-5505 J9 J NUCL MED JI J. Nucl. Med. PD MAY PY 1998 VL 39 IS 5 SU S MA 327 BP 84P EP 84P PG 1 WC Radiology, Nuclear Medicine & Medical Imaging SC Radiology, Nuclear Medicine & Medical Imaging GA ZM639 UT WOS:000073560300327 ER PT J AU Wilbur, DS Hamlin, DK Tingey, JM Bray, LA Egorov, OB Pathare, PM Brechbiel, MW Sandmaier, BM AF Wilbur, DS Hamlin, DK Tingey, JM Bray, LA Egorov, OB Pathare, PM Brechbiel, MW Sandmaier, BM TI Studies of labeling proteins with the alpha-emitting radionuclide Bi-213. SO JOURNAL OF NUCLEAR MEDICINE LA English DT Meeting Abstract C1 Univ Washington, Seattle, WA 98195 USA. Pacific NW Natl Lab, Richland, WA USA. NIH, Bethesda, MD 20892 USA. Fred Hutchinson Canc Res Ctr, Seattle, WA 98104 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU SOC NUCLEAR MEDICINE INC PI RESTON PA 1850 SAMUEL MORSE DR, RESTON, VA 20190-5316 USA SN 0161-5505 J9 J NUCL MED JI J. Nucl. Med. PD MAY PY 1998 VL 39 IS 5 SU S MA 355 BP 91P EP 91P PG 1 WC Radiology, Nuclear Medicine & Medical Imaging SC Radiology, Nuclear Medicine & Medical Imaging GA ZM639 UT WOS:000073560300355 ER PT J AU Luo, H Beets, AL Knapp, FF AF Luo, H Beets, AL Knapp, FF TI A new derivatized aza-thio (N2S4) crown ether ligand for bifunctional chelate labeling of therapeutic agents with silver-111. SO JOURNAL OF NUCLEAR MEDICINE LA English DT Meeting Abstract C1 Oak Ridge Natl Lab, Nucl Med Grp, Oak Ridge, TN USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU SOC NUCLEAR MEDICINE INC PI RESTON PA 1850 SAMUEL MORSE DR, RESTON, VA 20190-5316 USA SN 0161-5505 J9 J NUCL MED JI J. Nucl. Med. PD MAY PY 1998 VL 39 IS 5 SU S MA 357 BP 92P EP 92P PG 1 WC Radiology, Nuclear Medicine & Medical Imaging SC Radiology, Nuclear Medicine & Medical Imaging GA ZM639 UT WOS:000073560300357 ER PT J AU Huesman, RH Klein, GJ Reutter, BW Reed, JH Grootoonk, S Budinger, TF AF Huesman, RH Klein, GJ Reutter, BW Reed, JH Grootoonk, S Budinger, TF TI List mode data acquisition for retrospective respiratory-cardiac gated PET. SO JOURNAL OF NUCLEAR MEDICINE LA English DT Meeting Abstract C1 Lawrence Berkeley Natl Lab, Berkeley, CA USA. UCL, London, England. CTI Inc, Knoxville, TN USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU SOC NUCLEAR MEDICINE INC PI RESTON PA 1850 SAMUEL MORSE DR, RESTON, VA 20190-5316 USA SN 0161-5505 J9 J NUCL MED JI J. Nucl. Med. PD MAY PY 1998 VL 39 IS 5 SU S MA 363 BP 93P EP 93P PG 1 WC Radiology, Nuclear Medicine & Medical Imaging SC Radiology, Nuclear Medicine & Medical Imaging GA ZM639 UT WOS:000073560300363 ER PT J AU Dewey, SL Morgan, AE Ashby, CR Logan, J Kushner, SA Kornetsky, C Volkow, ND Fowler, JS Brodie, JD AF Dewey, SL Morgan, AE Ashby, CR Logan, J Kushner, SA Kornetsky, C Volkow, ND Fowler, JS Brodie, JD TI A new gabaergic strategy for treating cocaine addiction. SO JOURNAL OF NUCLEAR MEDICINE LA English DT Meeting Abstract C1 Brookhaven Natl Lab, Chem & Med Dept, Upton, NY 11973 USA. NYU, Dept Psychiat, New York, NY 10016 USA. St Johns Univ, Dept Pharm Hlth Sci, Jamaica, NY 11439 USA. Boston Univ, Dept Psychiat, Boston, MA 02215 USA. NR 0 TC 1 Z9 1 U1 0 U2 0 PU SOC NUCLEAR MEDICINE INC PI RESTON PA 1850 SAMUEL MORSE DR, RESTON, VA 20190-5316 USA SN 0161-5505 J9 J NUCL MED JI J. Nucl. Med. PD MAY PY 1998 VL 39 IS 5 SU S MA 388 BP 99P EP 100P PG 2 WC Radiology, Nuclear Medicine & Medical Imaging SC Radiology, Nuclear Medicine & Medical Imaging GA ZM639 UT WOS:000073560300388 ER PT J AU Volkow, ND Wang, GJ Fowler, JS Hitzemann, RJ Wong, C Gatley, JS Angrist, B Pappas, N AF Volkow, ND Wang, GJ Fowler, JS Hitzemann, RJ Wong, C Gatley, JS Angrist, B Pappas, N TI Brain metabolic changes induced by methylphenidate in cocaine abusers and in controls. SO JOURNAL OF NUCLEAR MEDICINE LA English DT Meeting Abstract C1 Brookhaven Natl Lab, Upton, NY 11973 USA. SUNY Stony Brook, Stony Brook, NY 11794 USA. NR 0 TC 1 Z9 1 U1 0 U2 0 PU SOC NUCLEAR MEDICINE INC PI RESTON PA 1850 SAMUEL MORSE DR, RESTON, VA 20190-5316 USA SN 0161-5505 J9 J NUCL MED JI J. Nucl. Med. PD MAY PY 1998 VL 39 IS 5 SU S MA 389 BP 100P EP 100P PG 1 WC Radiology, Nuclear Medicine & Medical Imaging SC Radiology, Nuclear Medicine & Medical Imaging GA ZM639 UT WOS:000073560300389 ER PT J AU Wang, GJ Volkow, ND Fowler, JS Hitzemann, RJ Wong, CT Felder, CA Piscani, K Pappas, NR AF Wang, GJ Volkow, ND Fowler, JS Hitzemann, RJ Wong, CT Felder, CA Piscani, K Pappas, NR TI Evaluation of regional cerebral metabolism in female alcoholics of moderate severity. SO JOURNAL OF NUCLEAR MEDICINE LA English DT Meeting Abstract C1 SUNY Stony Brook, Dept Psychiat, Stony Brook, NY 11794 USA. SUNY Stony Brook, Dept Radiol, Stony Brook, NY 11794 USA. Brookhaven Natl Lab, Dept Chem, Upton, NY 11973 USA. Brookhaven Natl Lab, Dept Med, Upton, NY 11973 USA. VA, Northport, NY USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU SOC NUCLEAR MEDICINE INC PI RESTON PA 1850 SAMUEL MORSE DR, RESTON, VA 20190-5316 USA SN 0161-5505 J9 J NUCL MED JI J. Nucl. Med. PD MAY PY 1998 VL 39 IS 5 SU S MA 391 BP 100P EP 100P PG 1 WC Radiology, Nuclear Medicine & Medical Imaging SC Radiology, Nuclear Medicine & Medical Imaging GA ZM639 UT WOS:000073560300391 ER PT J AU Guhlke, S Sartor, J Kornetka, ZW Knapp, FF Lisic, EC Biersack, HJ AF Guhlke, S Sartor, J Kornetka, ZW Knapp, FF Lisic, EC Biersack, HJ TI RE-188-MAG2 and -MAG2 conjugates of amino-bis-phosphonates as new bone seeking agents. SO JOURNAL OF NUCLEAR MEDICINE LA English DT Meeting Abstract C1 Oak Ridge Natl Lab, Nucl Med Grp, Oak Ridge, TN USA. Univ Bonn, Clin Nucl Med, D-5300 Bonn, Germany. Tennessee Technol Univ, Dept Chem, Cookeville, TN 38505 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU SOC NUCLEAR MEDICINE INC PI RESTON PA 1850 SAMUEL MORSE DR, RESTON, VA 20190-5316 USA SN 0161-5505 J9 J NUCL MED JI J. Nucl. Med. PD MAY PY 1998 VL 39 IS 5 SU S MA 409 BP 105P EP 105P PG 1 WC Radiology, Nuclear Medicine & Medical Imaging SC Radiology, Nuclear Medicine & Medical Imaging GA ZM639 UT WOS:000073560300409 ER PT J AU Kadrmas, DJ Di Bella, EVR Gullberg, GT AF Kadrmas, DJ Di Bella, EVR Gullberg, GT TI Statistically efficient estimation of kinetic parameters in dynamic cardiac SPECT SO JOURNAL OF NUCLEAR MEDICINE LA English DT Meeting Abstract C1 Univ Utah, Salt Lake City, UT USA. Lawrence Berkeley Natl Lab, Berkeley, CA USA. NR 0 TC 0 Z9 0 U1 0 U2 1 PU SOC NUCLEAR MEDICINE INC PI RESTON PA 1850 SAMUEL MORSE DR, RESTON, VA 20190-5316 USA SN 0161-5505 J9 J NUCL MED JI J. Nucl. Med. PD MAY PY 1998 VL 39 IS 5 SU S MA 568 BP 144P EP 144P PG 1 WC Radiology, Nuclear Medicine & Medical Imaging SC Radiology, Nuclear Medicine & Medical Imaging GA ZM639 UT WOS:000073560300567 ER PT J AU Li, J Liang, Z You, J Yang, F Kuan, H Wong, C Wang, G AF Li, J Liang, Z You, J Yang, F Kuan, H Wong, C Wang, G TI On the dual samplings of collimator holes and photomultipliers in SPECT imaging. SO JOURNAL OF NUCLEAR MEDICINE LA English DT Meeting Abstract C1 SUNY Stony Brook, Stony Brook, NY 11794 USA. BNL, Upton, NY USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU SOC NUCLEAR MEDICINE INC PI RESTON PA 1850 SAMUEL MORSE DR, RESTON, VA 20190-5316 USA SN 0161-5505 J9 J NUCL MED JI J. Nucl. Med. PD MAY PY 1998 VL 39 IS 5 SU S MA 770 BP 169P EP 169P PG 1 WC Radiology, Nuclear Medicine & Medical Imaging SC Radiology, Nuclear Medicine & Medical Imaging GA ZM639 UT WOS:000073560300666 ER PT J AU Meyer, MA Caday, CG Toohey, RE AF Meyer, MA Caday, CG Toohey, RE TI Radiotherapy of hypermetabolic gliomas using 18F-FDG: Tumor self dose S value calculations for F18 SO JOURNAL OF NUCLEAR MEDICINE LA English DT Meeting Abstract C1 Univ Missouri, Dept Neurol, Columbia, MO USA. Louisiana State Univ, Med Ctr, Dept Neurosurg, Shreveport, LA USA. Oak Ridge Inst Sci & Educ, Radiat Internal Dose Informat Ctr, Oak Ridge, TN USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU SOC NUCLEAR MEDICINE INC PI RESTON PA 1850 SAMUEL MORSE DR, RESTON, VA 20190-5316 USA SN 0161-5505 J9 J NUCL MED JI J. Nucl. Med. PD MAY PY 1998 VL 39 IS 5 SU S MA 830 BP 184P EP 184P PG 1 WC Radiology, Nuclear Medicine & Medical Imaging SC Radiology, Nuclear Medicine & Medical Imaging GA ZM639 UT WOS:000073560300727 ER PT J AU Stabin, M Kennel, S Mirzadeh, S AF Stabin, M Kennel, S Mirzadeh, S TI Radiation dosimetry for a Bi-213 monoclonal antibody bound to membranes of monolayer and spheroid cultures of tumor cells. SO JOURNAL OF NUCLEAR MEDICINE LA English DT Meeting Abstract C1 Oak Ridge Natl Lab, Oak Ridge, TN USA. Oak Ridge Inst Sci & Educ, Oak Ridge, TN USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU SOC NUCLEAR MEDICINE INC PI RESTON PA 1850 SAMUEL MORSE DR, RESTON, VA 20190-5316 USA SN 0161-5505 J9 J NUCL MED JI J. Nucl. Med. PD MAY PY 1998 VL 39 IS 5 SU S MA 829 BP 184P EP 184P PG 1 WC Radiology, Nuclear Medicine & Medical Imaging SC Radiology, Nuclear Medicine & Medical Imaging GA ZM639 UT WOS:000073560300726 ER PT J AU Stabin, MG Konijnenberg, M AF Stabin, MG Konijnenberg, M TI Model calculations of the radiation dose to the walls of blood vessels. SO JOURNAL OF NUCLEAR MEDICINE LA English DT Meeting Abstract C1 Mallinckordt Med, Petten, Netherlands. Oak Ridge Inst Sci & Educ, Oak Ridge, TN USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU SOC NUCLEAR MEDICINE INC PI RESTON PA 1850 SAMUEL MORSE DR, RESTON, VA 20190-5316 USA SN 0161-5505 J9 J NUCL MED JI J. Nucl. Med. PD MAY PY 1998 VL 39 IS 5 SU S MA 831 BP 184P EP 184P PG 1 WC Radiology, Nuclear Medicine & Medical Imaging SC Radiology, Nuclear Medicine & Medical Imaging GA ZM639 UT WOS:000073560300728 ER PT J AU Stabin, M Konijnenberg, M AF Stabin, M Konijnenberg, M TI Re-evaluation of absorbed fractions for photons and electrons in small spheres. SO JOURNAL OF NUCLEAR MEDICINE LA English DT Meeting Abstract C1 Mallinckrodt Med, Petten, Netherlands. Oak Ridge Natl Lab, Inst Sci & Educ, Oak Ridge, TN USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU SOC NUCLEAR MEDICINE INC PI RESTON PA 1850 SAMUEL MORSE DR, RESTON, VA 20190-5316 USA SN 0161-5505 J9 J NUCL MED JI J. Nucl. Med. PD MAY PY 1998 VL 39 IS 5 SU S MA 847 BP 188P EP 188P PG 1 WC Radiology, Nuclear Medicine & Medical Imaging SC Radiology, Nuclear Medicine & Medical Imaging GA ZM639 UT WOS:000073560300744 ER PT J AU Kotzerke, J Fenchel, S Guhlmann, A Stabin, M Knapp, FF Reske, SN AF Kotzerke, J Fenchel, S Guhlmann, A Stabin, M Knapp, FF Reske, SN TI Pharmacokinetics of Tc-99m-pertechnetate and Re-188-perrhenate after oral application of perchlorate - Significant radiation reduction achievable. SO JOURNAL OF NUCLEAR MEDICINE LA English DT Meeting Abstract C1 Univ Hosp, Dept Nucl Med, Ulm, Germany. Oak Ridge Natl Lab, Inst Sci & Educ, Oak Ridge, TN USA. Oak Ridge Natl Lab, Nucl Med Grp, Oak Ridge, TN USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU SOC NUCLEAR MEDICINE INC PI RESTON PA 1850 SAMUEL MORSE DR, RESTON, VA 20190-5316 USA SN 0161-5505 J9 J NUCL MED JI J. Nucl. Med. PD MAY PY 1998 VL 39 IS 5 SU S MA 854 BP 190P EP 190P PG 1 WC Radiology, Nuclear Medicine & Medical Imaging SC Radiology, Nuclear Medicine & Medical Imaging GA ZM639 UT WOS:000073560300751 ER PT J AU Nordahl, TE VanBrocklin, HF O'Neil, JP Kusubov, N Klein, G Budinger, TF AF Nordahl, TE VanBrocklin, HF O'Neil, JP Kusubov, N Klein, G Budinger, TF TI Evaluation of [F-18]fluoro-m-tyrosine (FMT) patient studies; Dosimetry and statistical considerations. SO JOURNAL OF NUCLEAR MEDICINE LA English DT Meeting Abstract C1 Lawrence Berkeley Lab, Berkeley, CA USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU SOC NUCLEAR MEDICINE INC PI RESTON PA 1850 SAMUEL MORSE DR, RESTON, VA 20190-5316 USA SN 0161-5505 J9 J NUCL MED JI J. Nucl. Med. PD MAY PY 1998 VL 39 IS 5 SU S MA 856 BP 190P EP 190P PG 1 WC Radiology, Nuclear Medicine & Medical Imaging SC Radiology, Nuclear Medicine & Medical Imaging GA ZM639 UT WOS:000073560300753 ER PT J AU Green, MA Mathias, CJ Low, PS Ellis, PR Stabin, MG Wendt, RE McCullough, SP Broussard, WF Gershenson, DM Podoloff, DA AF Green, MA Mathias, CJ Low, PS Ellis, PR Stabin, MG Wendt, RE McCullough, SP Broussard, WF Gershenson, DM Podoloff, DA TI Initial experience with In-111-DTPA-Folate (FolateScan) in humans: Assessment of tracer excretion kinetics and radiation dosimetry. SO JOURNAL OF NUCLEAR MEDICINE LA English DT Meeting Abstract C1 Purdue Univ, W Lafayette, IN 47907 USA. Oak Ridge Associated Univ, ORISE, Oak Ridge, TN 37831 USA. Endocyte Inc, W Lafayette, IN 47906 USA. Md Anderson Canc Ctr, Houston, TX 77030 USA. NR 0 TC 3 Z9 3 U1 0 U2 0 PU SOC NUCLEAR MEDICINE INC PI RESTON PA 1850 SAMUEL MORSE DR, RESTON, VA 20190-5316 USA SN 0161-5505 J9 J NUCL MED JI J. Nucl. Med. PD MAY PY 1998 VL 39 IS 5 SU S MA 858 BP 191P EP 191P PG 1 WC Radiology, Nuclear Medicine & Medical Imaging SC Radiology, Nuclear Medicine & Medical Imaging GA ZM639 UT WOS:000073560300755 ER PT J AU Eberling, JL Enas, JD Budinger, TF AF Eberling, JL Enas, JD Budinger, TF TI The misidentification of midbrain anatomical structures using neurochemical imaging. SO JOURNAL OF NUCLEAR MEDICINE LA English DT Meeting Abstract C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Ctr Funct Imaging, Berkeley, CA USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU SOC NUCLEAR MEDICINE INC PI RESTON PA 1850 SAMUEL MORSE DR, RESTON, VA 20190-5316 USA SN 0161-5505 J9 J NUCL MED JI J. Nucl. Med. PD MAY PY 1998 VL 39 IS 5 SU S MA 927 BP 208P EP 208P PG 1 WC Radiology, Nuclear Medicine & Medical Imaging SC Radiology, Nuclear Medicine & Medical Imaging GA ZM639 UT WOS:000073560300825 ER PT J AU Gatley, SJ Meinken, GE Freimuth, P Pyatt, B Srivastava, SC Volkov, ND AF Gatley, SJ Meinken, GE Freimuth, P Pyatt, B Srivastava, SC Volkov, ND TI Quantification of rodent tissue binding sites for adenoviruses using radioiodinated fiber protein SO JOURNAL OF NUCLEAR MEDICINE LA English DT Meeting Abstract C1 Brookhaven Natl Lab, Upton, NY 11973 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU SOC NUCLEAR MEDICINE INC PI RESTON PA 1850 SAMUEL MORSE DR, RESTON, VA 20190-5316 USA SN 0161-5505 J9 J NUCL MED JI J. Nucl. Med. PD MAY PY 1998 VL 39 IS 5 SU S MA 985 BP 222P EP 222P PG 1 WC Radiology, Nuclear Medicine & Medical Imaging SC Radiology, Nuclear Medicine & Medical Imaging GA ZM639 UT WOS:000073560300885 ER PT J AU Marshall, RC VanBrocklin, HF Enas, JD Powers-Risius, P Taylor, SE Huesman, RH Reutter, BW Budinger, TF AF Marshall, RC VanBrocklin, HF Enas, JD Powers-Risius, P Taylor, SE Huesman, RH Reutter, BW Budinger, TF TI Kinetic analysis of I-125-rotenone as a deposited myocardial flow tracer: Comparison to TC-99m-sestamibi. SO JOURNAL OF NUCLEAR MEDICINE LA English DT Meeting Abstract C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Ctr Funct Imaging, Berkeley, CA 94720 USA. Martitnez Vet Affairs, No Calif Hlth Care Syst, Martinez, CA USA. NR 0 TC 1 Z9 1 U1 0 U2 0 PU SOC NUCLEAR MEDICINE INC PI RESTON PA 1850 SAMUEL MORSE DR, RESTON, VA 20190-5316 USA SN 0161-5505 J9 J NUCL MED JI J. Nucl. Med. PD MAY PY 1998 VL 39 IS 5 SU S MA 1009 BP 228P EP 228P PG 1 WC Radiology, Nuclear Medicine & Medical Imaging SC Radiology, Nuclear Medicine & Medical Imaging GA ZM639 UT WOS:000073560300909 ER PT J AU VanBrocklin, HF Negash, K Kenski, DM Nagy, D Waterhouse, RN AF VanBrocklin, HF Negash, K Kenski, DM Nagy, D Waterhouse, RN TI In vivo evaluation of 1-(4[F-18]fluorobenzyl)-4-(4-cyanophenoxymethy)piperidine ([F-18]FBnCNE): A high affinity sigma-1/sigma-2 receptor ligand for pet. SO JOURNAL OF NUCLEAR MEDICINE LA English DT Meeting Abstract C1 Duke Univ, Med Ctr, Dept Radiol, Durham, NC 27710 USA. Lawrence Berkeley Lab, Ctr Funct Imaging, Berkeley, CA USA. NR 0 TC 1 Z9 1 U1 0 U2 0 PU SOC NUCLEAR MEDICINE INC PI RESTON PA 1850 SAMUEL MORSE DR, RESTON, VA 20190-5316 USA SN 0161-5505 J9 J NUCL MED JI J. Nucl. Med. PD MAY PY 1998 VL 39 IS 5 SU S MA 1014 BP 229P EP 229P PG 1 WC Radiology, Nuclear Medicine & Medical Imaging SC Radiology, Nuclear Medicine & Medical Imaging GA ZM639 UT WOS:000073560300914 ER PT J AU Taylor, SE O'Neil, JP Budinger, TF Kahl, SB AF Taylor, SE O'Neil, JP Budinger, TF Kahl, SB TI Synthesis and PET evaluation of a [Cu-64]Cu-labeled boronated-porphyrin. SO JOURNAL OF NUCLEAR MEDICINE LA English DT Meeting Abstract C1 Univ Calif San Francisco, Dept Pharmaceut Chem, San Francisco, CA 94143 USA. Lawrence Berkeley Lab, Ctr Funct Imaging, Berkeley, CA USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU SOC NUCLEAR MEDICINE INC PI RESTON PA 1850 SAMUEL MORSE DR, RESTON, VA 20190-5316 USA SN 0161-5505 J9 J NUCL MED JI J. Nucl. Med. PD MAY PY 1998 VL 39 IS 5 SU S MA 1030 BP 233P EP 233P PG 1 WC Radiology, Nuclear Medicine & Medical Imaging SC Radiology, Nuclear Medicine & Medical Imaging GA ZM639 UT WOS:000073560300930 ER PT J AU Chung, YS Jeong, JM Lee, DS Chung, JK Lee, MC Koh, CS Yu, HJ Cho, JH Knapp, FF AF Chung, YS Jeong, JM Lee, DS Chung, JK Lee, MC Koh, CS Yu, HJ Cho, JH Knapp, FF TI Effect of carrier on labeling and biodistribution of Re-188-hydroxyethylidene diphosphonate (HEDP) in mice and rats. SO JOURNAL OF NUCLEAR MEDICINE LA English DT Meeting Abstract C1 Oak Ridge Natl Lab, Oak Ridge, TN USA. Seoul Natl Univ, Coll Med, Korea Inst Sci & Technol, Seoul, South Korea. RI Jeong, Jae Min/E-2102-2012 OI Jeong, Jae Min/0000-0003-2611-6020 NR 0 TC 1 Z9 1 U1 0 U2 0 PU SOC NUCLEAR MEDICINE INC PI RESTON PA 1850 SAMUEL MORSE DR, RESTON, VA 20190-5316 USA SN 0161-5505 J9 J NUCL MED JI J. Nucl. Med. PD MAY PY 1998 VL 39 IS 5 SU S MA 1037 BP 235P EP 235P PG 1 WC Radiology, Nuclear Medicine & Medical Imaging SC Radiology, Nuclear Medicine & Medical Imaging GA ZM639 UT WOS:000073560300937 ER PT J AU Ding, YS Alexoff, D Fowler, JS Volkow, ND AF Ding, YS Alexoff, D Fowler, JS Volkow, ND TI Synthesis and preliminary PET studies of [C-11]caffeine. SO JOURNAL OF NUCLEAR MEDICINE LA English DT Meeting Abstract C1 Brookhaven Natl Lab, Dept Chem, Upton, NY 11973 USA. Brookhaven Natl Lab, Dept Med, Upton, NY 11973 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU SOC NUCLEAR MEDICINE INC PI RESTON PA 1850 SAMUEL MORSE DR, RESTON, VA 20190-5316 USA SN 0161-5505 J9 J NUCL MED JI J. Nucl. Med. PD MAY PY 1998 VL 39 IS 5 SU S MA 1052 BP 238P EP 239P PG 2 WC Radiology, Nuclear Medicine & Medical Imaging SC Radiology, Nuclear Medicine & Medical Imaging GA ZM639 UT WOS:000073560300952 ER PT J AU O'Neil, JP VanBrocklin, HF AF O'Neil, JP VanBrocklin, HF TI A remote synthesis device for electrophilic fluorination. SO JOURNAL OF NUCLEAR MEDICINE LA English DT Meeting Abstract C1 Lawrence Berkeley Lab, Ctr Funct Imaging, Biomed Isotope Facil, Berkeley, CA USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU SOC NUCLEAR MEDICINE INC PI RESTON PA 1850 SAMUEL MORSE DR, RESTON, VA 20190-5316 USA SN 0161-5505 J9 J NUCL MED JI J. Nucl. Med. PD MAY PY 1998 VL 39 IS 5 SU S MA 1058 BP 240P EP 240P PG 1 WC Radiology, Nuclear Medicine & Medical Imaging SC Radiology, Nuclear Medicine & Medical Imaging GA ZM639 UT WOS:000073560300958 ER PT J AU Beets, AL Guhlke, S Mirzadeh, S Biersack, HJ Knapp, FF AF Beets, AL Guhlke, S Mirzadeh, S Biersack, HJ Knapp, FF TI Use of new "tandem" cation/anion exchange column system provides high specific volume Tc-99m solutions from low specific activity (n,y) Mo-99. SO JOURNAL OF NUCLEAR MEDICINE LA English DT Meeting Abstract C1 Oak Ridge Natl Lab, Nucl Med Grp, Oak Ridge, TN USA. Univ Bonn, Clin Nucl Med, D-5300 Bonn, Germany. NR 0 TC 0 Z9 0 U1 0 U2 0 PU SOC NUCLEAR MEDICINE INC PI RESTON PA 1850 SAMUEL MORSE DR, RESTON, VA 20190-5316 USA SN 0161-5505 J9 J NUCL MED JI J. Nucl. Med. PD MAY PY 1998 VL 39 IS 5 SU S MA 1062 BP 241P EP 241P PG 1 WC Radiology, Nuclear Medicine & Medical Imaging SC Radiology, Nuclear Medicine & Medical Imaging GA ZM639 UT WOS:000073560300962 ER PT J AU Firouzbakht, ML Schlyer, DL Fowler, JS AF Firouzbakht, ML Schlyer, DL Fowler, JS TI Irradiation of ammonia at liquid nitrogen temperatures: Direct production of C-11 cyanide and the mechanistic implications. SO JOURNAL OF NUCLEAR MEDICINE LA English DT Meeting Abstract C1 Brookhaven Natl Lab, Upton, NY 11713 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU SOC NUCLEAR MEDICINE INC PI RESTON PA 1850 SAMUEL MORSE DR, RESTON, VA 20190-5316 USA SN 0161-5505 J9 J NUCL MED JI J. Nucl. Med. PD MAY PY 1998 VL 39 IS 5 SU S MA 1061 BP 241P EP 241P PG 1 WC Radiology, Nuclear Medicine & Medical Imaging SC Radiology, Nuclear Medicine & Medical Imaging GA ZM639 UT WOS:000073560300961 ER PT J AU Mozley, PD Barraclough, ED Dresel, S Stubbs, JB Finkelman, C Mathur, A Sparks, RB Patel, M Smith, T Thakur, M Alavi, A AF Mozley, PD Barraclough, ED Dresel, S Stubbs, JB Finkelman, C Mathur, A Sparks, RB Patel, M Smith, T Thakur, M Alavi, A TI Dosimetry of anti-SSEA-1: A technetium-99m labeled, IGM murine antibody to human granulocytes. SO JOURNAL OF NUCLEAR MEDICINE LA English DT Meeting Abstract C1 Oak Ridge Inc, Internal Dosimetry Syst, Oak Ridge, TN USA. Univ Penn, Philadelphia, PA 19104 USA. Palatin Inc, Edison, NJ USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU SOC NUCLEAR MEDICINE INC PI RESTON PA 1850 SAMUEL MORSE DR, RESTON, VA 20190-5316 USA SN 0161-5505 J9 J NUCL MED JI J. Nucl. Med. PD MAY PY 1998 VL 39 IS 5 SU S MA 1176 BP 268P EP 268P PG 1 WC Radiology, Nuclear Medicine & Medical Imaging SC Radiology, Nuclear Medicine & Medical Imaging GA ZM639 UT WOS:000073560301073 ER PT J AU Stabin, MG AF Stabin, MG TI MIRDOSE 3.1 gives erroneous results under Windows NT - Reply SO JOURNAL OF NUCLEAR MEDICINE LA English DT Letter C1 Oak Ridge Inst Sci & Educ, Radiat Internal Dose Informat Ctr, Oak Ridge, TN USA. RP Stabin, MG (reprint author), Oak Ridge Inst Sci & Educ, Radiat Internal Dose Informat Ctr, Oak Ridge, TN USA. NR 0 TC 2 Z9 2 U1 0 U2 0 PU SOC NUCLEAR MEDICINE INC PI RESTON PA 1850 SAMUEL MORSE DR, RESTON, VA 20190-5316 USA SN 0161-5505 J9 J NUCL MED JI J. Nucl. Med. PD MAY PY 1998 VL 39 IS 5 BP 927 EP 927 PG 1 WC Radiology, Nuclear Medicine & Medical Imaging SC Radiology, Nuclear Medicine & Medical Imaging GA ZL912 UT WOS:000073486000047 ER PT J AU Ronin, D Strehl, F AF Ronin, D Strehl, F TI Elevation of zinc protoporphyrin levels in lead workers with iron-sufficient microcytosis SO JOURNAL OF OCCUPATIONAL AND ENVIRONMENTAL MEDICINE LA English DT Article AB Zinc protoporphyrin (ZPP) measurement is a required test under the Occupational Safety and Health Administration's lead standard. However, there is no mention of the influence of hemoglobinopathy on the ZPP test value. We undertook a retrospective laboratory review of 382 employees at the Argonne National Laboratory who had been subjects in a lead surveillance program since 1982. A total of 321 samples were analyzed, after female subjects and samples with abnormally high bilirubin levels were excluded. A group with low mean red blood cell volume (MCV; less than 80.0 fL) was compared with a group with normal MCV (greater or equal to 80.0 fL). A statistically significant difference teas noted in ZPP (P < 0.007) and total bibirubin (P < 0.0003) values of two groups. There was no statistically significant difference noted in age, lead levels, or iron levels between the two groups. Abnormally high ZPP levels may occur in individuals with hemoglobinopathies. Only a minor part of this elevation could be explained by the higher bilirubin levels. C1 Argonne Natl Lab, Argonne, IL 60439 USA. RP Ronin, D (reprint author), Argonne Natl Lab, 9700 S Cass Ave,Bldg 201, Argonne, IL 60439 USA. NR 6 TC 1 Z9 1 U1 0 U2 0 PU LIPPINCOTT WILLIAMS & WILKINS PI PHILADELPHIA PA 227 EAST WASHINGTON SQ, PHILADELPHIA, PA 19106 USA SN 1076-2752 J9 J OCCUP ENVIRON MED JI J. Occup. Environ. Med. PD MAY PY 1998 VL 40 IS 5 BP 492 EP 496 DI 10.1097/00043764-199805000-00013 PG 5 WC Public, Environmental & Occupational Health SC Public, Environmental & Occupational Health GA ZU854 UT WOS:000074242300013 PM 9604187 ER PT J AU Griffies, SM Gnanadesikan, A Pacanowski, RC Larichev, VD Dukowicz, JK Smith, RD AF Griffies, SM Gnanadesikan, A Pacanowski, RC Larichev, VD Dukowicz, JK Smith, RD TI Isoneutral diffusion in a z-coordinate ocean model SO JOURNAL OF PHYSICAL OCEANOGRAPHY LA English DT Article ID GENERAL-CIRCULATION MODELS; TRACER TRANSPORTS; NORTH-ATLANTIC; THERMOCLINE AB This paper considers the requirements that must be satisfied in order to provide a stable and physically based isoneutral tracer diffusion scheme in a z-coordinate ocean model. Two properties are emphasized: 1) downgradient orientation of the diffusive fluxes along the neutral directions and 2) zero isoneutral diffusive flux of locally referenced potential density. It is shown that the Cox diffusion scheme does not respect either of these properties, which provides an explanation for the necessity to add a nontrivial background horizontal diffusion to that scheme. A new isoneutral diffusion scheme is proposed that aims to satisfy the stated properties and is found to require no horizontal background diffusion. C1 Princeton Univ, Geophys Fluid Dynam Lab, Princeton, NJ 08542 USA. Princeton Univ, Atmospher & Ocean Sci Program, Princeton, NJ 08542 USA. Univ Calif Los Alamos Natl Lab, Div Theoret, Los Alamos, NM USA. RP Griffies, SM (reprint author), Princeton Univ, Geophys Fluid Dynam Lab, Route 1,Forrestal Campus, Princeton, NJ 08542 USA. RI Gnanadesikan, Anand/A-2397-2008 OI Gnanadesikan, Anand/0000-0001-5784-1116 NR 49 TC 154 Z9 154 U1 0 U2 6 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0022-3670 J9 J PHYS OCEANOGR JI J. Phys. Oceanogr. PD MAY PY 1998 VL 28 IS 5 BP 805 EP 830 DI 10.1175/1520-0485(1998)028<0805:IDIAZC>2.0.CO;2 PG 26 WC Oceanography SC Oceanography GA ZP532 UT WOS:000073762900005 ER PT J AU Chopra, OK Gavenda, DJ AF Chopra, OK Gavenda, DJ TI Effects of LWR coolant environments on fatigue lives of austenitic stainless steels SO JOURNAL OF PRESSURE VESSEL TECHNOLOGY-TRANSACTIONS OF THE ASME LA English DT Article; Proceedings Paper CT Pressure Vessels and Piping Conference of the American-Society-of-Mechanical-Engineers CY JUL 27-31, 1997 CL ORLANDO, FLORIDA SP Amer Soc Mech Engineers AB Fatigue tests have been conducted on Types 304 and 316NG stainless steels to evaluate the effects of various material and loading variables, e.g.,, steel type, strain rare, dissolved oxygen (DO) in water, and strain range, on the fatigue lives of these steels, The results confirm significant decreases in fatigue life in water: Unlike the situation with ferritic steels, environmental effects on Types 304 and 316NG stainless steel are more pronounced in low-DO than in high-DO water. Experimental results have been compared with estimates of fatigue life based on a statistical model. The formation and growth of fatigue clacks in air and water environments are discussed. C1 Argonne Natl Lab, Div Energy Technol, Argonne, IL 60439 USA. RP Chopra, OK (reprint author), Argonne Natl Lab, Div Energy Technol, 9700 S Cass Ave, Argonne, IL 60439 USA. NR 17 TC 11 Z9 12 U1 0 U2 1 PU ASME-AMER SOC MECHANICAL ENG PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 0094-9930 J9 J PRESS VESS-T ASME JI J. Press. Vessel Technol.-Trans. ASME PD MAY PY 1998 VL 120 IS 2 BP 116 EP 121 DI 10.1115/1.2842228 PG 6 WC Engineering, Mechanical SC Engineering GA ZP651 UT WOS:000073774800002 ER PT J AU Kleinke, H Franzen, HF AF Kleinke, H Franzen, HF TI Sc-Sc bonding in the new ternary phosphide ScNiP SO JOURNAL OF SOLID STATE CHEMISTRY LA English DT Article DE scandium nickel phosphide; preparation; structure and bonding; pseudo gap; magnetism ID CRYSTAL-STRUCTURE; PHOSPHORUS; METAL; CO; NI AB The new phosphide ScNip can be synthesized by are-melting of ScP and Ni, or by are-melting of Sc with NiP. The lattice Synthesis constants, as obtained from the bulk sample, are a = 6.3343(8) Angstrom b = 3.7375(7) Angstrom, c = 7.0917(8), and V = 167.89(4) Angstrom(3). ScNiP crystallizes in the Co2Si structure type. Although one might assign the trivalent state to Sc, corresponding to a formal ionic formula of SC3+Ni+/-0P3-, the structure of ScNiP contains Sc-Sc bonds and shows weak metallic properties, as expected based on extended Huckel calculations, (C) 1998 Academic Press. C1 Iowa State Univ, US DOE, Ames Lab, Ames, IA 50011 USA. RP Kleinke, H (reprint author), Iowa State Univ, US DOE, Ames Lab, Ames, IA 50011 USA. NR 14 TC 6 Z9 6 U1 0 U2 2 PU ACADEMIC PRESS INC PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0022-4596 J9 J SOLID STATE CHEM JI J. Solid State Chem. PD MAY PY 1998 VL 137 IS 2 BP 218 EP 222 DI 10.1006/jssc.1997.7704 PG 5 WC Chemistry, Inorganic & Nuclear; Chemistry, Physical SC Chemistry GA ZX037 UT WOS:000074473900006 ER PT J AU Felmy, AR Mason, MJ AF Felmy, AR Mason, MJ TI The displacement of Sr from organic chelates by hydroxide, carbonate, and calcium in concentrated electrolytes SO JOURNAL OF SOLUTION CHEMISTRY LA English DT Article DE EDTA; HEDTA; NTA; IDA; solubility; strontium; calcium; waste processing ID COMPLEXES; STABILITY AB The effects of calcium, hydroxide, and carbonate on the displacement of Sr from four organic chelates: ethylenedinitrilotetraacetic acid (EDTA), N-(2-hydroxyethyl)ethylenedinitrilotriacetic acid (HEDTA) nitrilotriacetic acid (NTA), and iminidiacetic acid (IDA) was studied in solutions with high base and carbonate concentration. Comparison of solutions with and without added chelators allowed the speciation changes in solution to be directly determined. Increases in both carbonate and calcium concentration were effective in displacing Sr from the chelators even under high carbonate concentration. Increases in hydroxide were ineffective in removal of Sr from the chelators, even at base concentrations as high as 6M. Under certain specific conditions, most notably when both CaCO3(s) and SrCO3(s) are present in solution, chemical equilibrium constraints result in cancelation of activity coefficient changes for aqueous Sr and Ca organic chelate complexes. Under such conditions the predicted ratios of chelated Ca and Sr become independent of the ionic media and predictive relations using known equilibrium constants give very good representations of the experimental data. These results indicate that manipulation of metal ion displacement reactions during chemical processing of Sr-chelate solutions can result in the displacement of Sr from organic chelators. The implications of such strategies in processing high level waste supernatants stored at Department of Energy (DOE) sites is discussed. C1 Pacific NW Natl Lab, Richland, WA 99352 USA. RP Felmy, AR (reprint author), Pacific NW Natl Lab, Richland, WA 99352 USA. NR 28 TC 4 Z9 4 U1 0 U2 1 PU PLENUM PUBL CORP PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 0095-9782 J9 J SOLUTION CHEM JI J. Solut. Chem. PD MAY PY 1998 VL 27 IS 5 BP 435 EP 454 DI 10.1023/A:1022652621788 PG 20 WC Chemistry, Physical SC Chemistry GA ZV900 UT WOS:000074353000004 ER PT J AU Blewett, JP AF Blewett, JP TI Synchrotron radiation - Early history SO JOURNAL OF SYNCHROTRON RADIATION LA English DT Article; Proceedings Paper CT 6th International Conference on Synchrotron Radiation Instrumentation (SRI'97) CY AUG 04-08, 1997 CL HIMEJI, JAPAN SP Japan Atom Energy Res Inst (JAERI), Inst Phys & Chem Res (RIKEN) DE history of synchrotron radiation; Lienard; Thomson; Schott; General Electric Research Laboratory; Schwinger AB The scientific history of the work that led to the prediction and observation of synchrotron radiation goes back more than a century. This paper is a summary of that history. C1 Brookhaven Natl Lab, Upton, NY 11973 USA. NR 14 TC 11 Z9 11 U1 0 U2 3 PU MUNKSGAARD INT PUBL LTD PI COPENHAGEN PA 35 NORRE SOGADE, PO BOX 2148, DK-1016 COPENHAGEN, DENMARK SN 0909-0495 J9 J SYNCHROTRON RADIAT JI J. Synchrot. Radiat. PD MAY 1 PY 1998 VL 5 BP 135 EP 139 DI 10.1107/S0909049597043306 PN 3 PG 5 WC Instruments & Instrumentation; Optics; Physics, Applied SC Instruments & Instrumentation; Optics; Physics GA 103UA UT WOS:000074975200003 PM 15263467 ER PT J AU Holmes, KC Rosenbaum, G AF Holmes, KC Rosenbaum, G TI How X-ray diffraction with synchrotron radiation got started SO JOURNAL OF SYNCHROTRON RADIATION LA English DT Article; Proceedings Paper CT 6th International Conference on Synchrotron Radiation Instrumentation (SRI'97) CY AUG 04-08, 1997 CL HIMEJI, JAPAN SP Japan Atom Energy Res Inst (JAERI), Inst Phys & Chem Res (RIKEN) DE X-rays; diffraction; muscle; EMBL ID INSECT FLIGHT-MUSCLE; MYOSIN MOTOR DOMAIN; ATOMIC MODEL; ACTIN; CONTRACTION; COMPLEX; REFLECTIONS; SCATTERING; MECHANISM AB The need to record low-angle-scattering X-ray fibre diagrams from muscle with millisecond time resolution drove the use of synchrotron radiation as an X-ray light source. The first smudgy diffraction patterns were obtained from a slice of insect flight muscle. Out of this grew the EMBL Outstation at DESY. C1 Argonne Natl Lab, Struct Biol Ctr, Argonne, IL 60439 USA. Max Planck Inst Med Forsch, D-6943020 Heidelberg, Germany. RP Holmes, KC (reprint author), Max Planck Inst Med Forsch, D-6943020 Heidelberg, Germany. OI Holmes, Kenneth/0000-0001-8894-9453 NR 30 TC 15 Z9 15 U1 0 U2 0 PU MUNKSGAARD INT PUBL LTD PI COPENHAGEN PA 35 NORRE SOGADE, PO BOX 2148, DK-1016 COPENHAGEN, DENMARK SN 0909-0495 J9 J SYNCHROTRON RADIAT JI J. Synchrot. Radiat. PD MAY 1 PY 1998 VL 5 BP 147 EP 153 DI 10.1107/S0909049597018578 PN 3 PG 7 WC Instruments & Instrumentation; Optics; Physics, Applied SC Instruments & Instrumentation; Optics; Physics GA 103UA UT WOS:000074975200005 PM 15263469 ER PT J AU Moncton, DE AF Moncton, DE TI The Advanced Photon Source: Performance and results from early operation SO JOURNAL OF SYNCHROTRON RADIATION LA English DT Article; Proceedings Paper CT 6th International Conference on Synchrotron Radiation Instrumentation (SRI'97) CY AUG 04-08, 1997 CL HIMEJI, JAPAN SP Japan Atom Energy Res Inst (JAERI), Inst Phys & Chem Res (RIKEN) DE Advanced Photon Source; storage rings; insertion devices; light sources AB The Advanced Photon Source at Argonne National Laboratory is now providing researchers with high-brilliance undulator radiation from below 1 keV to beyond 100 keV. All technical facilities and components are operational and have met design specifications. Fourteen research teams, with responsibility for 40 beamlines on the APS experiment hall floor, are currently installing beamline instrumentation or actively taking data. An overview is presented for the first operational year of the Advanced Photon Source. Emphasis is on the performance of accelerators and insertion devices, as well as early scientific results and future plans. C1 Argonne Natl Lab, Adv Photon Source, Argonne, IL 60439 USA. RP Moncton, DE (reprint author), Argonne Natl Lab, Adv Photon Source, 9700 S Cass Ave, Argonne, IL 60439 USA. NR 5 TC 4 Z9 4 U1 2 U2 3 PU MUNKSGAARD INT PUBL LTD PI COPENHAGEN PA 35 NORRE SOGADE, PO BOX 2148, DK-1016 COPENHAGEN, DENMARK SN 0909-0495 J9 J SYNCHROTRON RADIAT JI J. Synchrot. Radiat. PD MAY 1 PY 1998 VL 5 BP 155 EP 157 DI 10.1107/S0909049597015410 PN 3 PG 3 WC Instruments & Instrumentation; Optics; Physics, Applied SC Instruments & Instrumentation; Optics; Physics GA 103UA UT WOS:000074975200006 PM 15263470 ER PT J AU Winick, H AF Winick, H TI Synchrotron radiation sources - Present capabilities and future directions SO JOURNAL OF SYNCHROTRON RADIATION LA English DT Article; Proceedings Paper CT 6th International Conference on Synchrotron Radiation Instrumentation (SRI'97) CY AUG 04-08, 1997 CL HIMEJI, JAPAN SP Japan Atom Energy Res Inst (JAERI), Inst Phys & Chem Res (RIKEN) DE fourth-generation sources; linacs; free-electron lasers; high brightness; low emittance ID SHORT-WAVELENGTH FELS; X-RAY; UNDULATOR AB Many of the more than 40 operational light sources around the world have achieved performance levels that exceed initial design goals. These accomplishments are reviewed, along with concepts and proposals for sources with performance levels exceeding those of present sources. These include storage rings with lower electron-beam emittance than present third-generation rings and free-electron lasers (FELs). It now appears that the highest performance sources will be based on linacs rather than storage rings. This is because emittance originates differently and scales differently with electron energy for rings and linacs, so that the lowest electron-beam emittance can be achieved in high-energy linacs equipped with high-brightness electron sources. Such electron beams can be used to provide X-ray beams with very high brightness and coherence in sub-picosecond pulses in a single pass through a small-gap short-period undulator by spontaneous emission, and with even higher beam brightness and coherence by stimulated coherent emission in an FEL. Designs for such FEL sources, and associated research and development, are underway at several laboratories. C1 Stanford Univ, Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. RP Winick, H (reprint author), Stanford Univ, Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. EM winick@slac.stanford.edu NR 40 TC 15 Z9 16 U1 6 U2 9 PU MUNKSGAARD INT PUBL LTD PI COPENHAGEN PA 35 NORRE SOGADE, PO BOX 2148, DK-1016 COPENHAGEN, DENMARK SN 0909-0495 J9 J SYNCHROTRON RADIAT JI J. Synchrot. Radiat. PD MAY 1 PY 1998 VL 5 BP 168 EP 175 DI 10.1107/S0909049597018761 PN 3 PG 8 WC Instruments & Instrumentation; Optics; Physics, Applied SC Instruments & Instrumentation; Optics; Physics GA 103UA UT WOS:000074975200009 PM 15263473 ER PT J AU Gluskin, E AF Gluskin, E TI APS insertion devices: Recent developments and results SO JOURNAL OF SYNCHROTRON RADIATION LA English DT Article; Proceedings Paper CT 6th International Conference on Synchrotron Radiation Instrumentation (SRI'97) CY AUG 04-08, 1997 CL HIMEJI, JAPAN SP Japan Atom Energy Res Inst (JAERI), Inst Phys & Chem Res (RIKEN) DE insertion devices; undulators; magnetic performance; radiation diagnostics ID UNDULATOR AB The Advanced Photon Source (APS) now has a total of 23 insertion devices (IDs). Over two-thirds of them are installed on the storage ring. The installed devices include 18, 27 and 55 mm-period undulators; an 85 mm-period wiggler; a 16 cm-period elliptical multipole wiggler; and many 33 mm-period undulators. Most of the IDs occupy storage-ring straight sections equipped with 8 mm vertical-aperture vacuum chambers. All of the IDs were measured magnetically at the APS and, in most cases, underwent a final magnetic tuning in order to minimize variation in the various integrals of the field through the ID over the full gap range. Special shimming techniques to correct magnetic field parameters in appropriate gap-dependent ways were developed and applied. Measurements of the closed-orbit distortion as a function of the ID gap variation have been completed, and results are in a good agreement with magnetic measurements. Spectral diagnostics of the ID radiation, including measurements of the absolute spectral flux, brilliance and polarization, show excellent agreement between calculated and measured results. Studies of the sensitivity of IDs to radiation exposure and measurements of the dose rate received by the IDs are in progress. C1 Argonne Natl Lab, Adv Photon Source, Argonne, IL 60439 USA. RP Gluskin, E (reprint author), Argonne Natl Lab, Adv Photon Source, 9700 S Cass Ave,APS-401, Argonne, IL 60439 USA. NR 29 TC 12 Z9 12 U1 0 U2 0 PU MUNKSGAARD INT PUBL LTD PI COPENHAGEN PA 35 NORRE SOGADE, PO BOX 2148, DK-1016 COPENHAGEN, DENMARK SN 0909-0495 J9 J SYNCHROTRON RADIAT JI J. Synchrot. Radiat. PD MAY 1 PY 1998 VL 5 BP 189 EP 195 DI 10.1107/S0909049597013769 PN 3 PG 7 WC Instruments & Instrumentation; Optics; Physics, Applied SC Instruments & Instrumentation; Optics; Physics GA 103UA UT WOS:000074975200013 PM 15263477 ER PT J AU Kim, KJ AF Kim, KJ TI Advanced capabilities for future light sources SO JOURNAL OF SYNCHROTRON RADIATION LA English DT Article; Proceedings Paper CT 6th International Conference on Synchrotron Radiation Instrumentation (SRI'97) CY AUG 04-08, 1997 CL HIMEJI, JAPAN SP Japan Atom Energy Res Inst (JAERI), Inst Phys & Chem Res (RIKEN) DE future light sources ID 90-DEGREES THOMSON SCATTERING; FREE-ELECTRON LASERS; X-RAYS; GENERATION; EMISSION; PULSES AB Methods to extend the capabilities of light sources beyond those available at the current generation synchrotron radiation sources based on undulators in electron storage rings are discussed. Taking advantage of the radiation-particle interaction and/or the availability of high-power ultrashort optical lasers, it is possible to develop sources with higher brightness, smaller temporal resolution, or higher photon energy. This paper is a summary of some of these schemes, with an emphasis on new ideas rather than on a comprehensive review. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Kim, KJ (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. NR 32 TC 1 Z9 1 U1 0 U2 1 PU MUNKSGAARD INT PUBL LTD PI COPENHAGEN PA 35 NORRE SOGADE, PO BOX 2148, DK-1016 COPENHAGEN, DENMARK SN 0909-0495 J9 J SYNCHROTRON RADIAT JI J. Synchrot. Radiat. PD MAY 1 PY 1998 VL 5 BP 202 EP 207 DI 10.1107/S0909049598000557 PN 3 PG 6 WC Instruments & Instrumentation; Optics; Physics, Applied SC Instruments & Instrumentation; Optics; Physics GA 103UA UT WOS:000074975200015 PM 15263479 ER PT J AU Tanabe, T Marechal, XM Tanaka, T Kitamura, H Stefan, PM AF Tanabe, T Marechal, XM Tanaka, T Kitamura, H Stefan, PM TI Development of an in-vacuum minipole undulator SO JOURNAL OF SYNCHROTRON RADIATION LA English DT Article; Proceedings Paper CT 6th International Conference on Synchrotron Radiation Instrumentation (SRI'97) CY AUG 04-08, 1997 CL HIMEJI, JAPAN SP Japan Atom Energy Res Inst (JAERI), Inst Phys & Chem Res (RIKEN) DE insertion devices; magnets AB An in-vacuum minipole (short-period) insertion device has been developed in a collaboration between SPring-8 and the National Synchrotron Light Source (NSLS). The magnetic arrays were constructed by SPring-8 and were installed in a chamber with mechanical parts in the X-ray ring (E = 2.584 GeV) at the NSLS in May 1997. The device is made of permanent magnets with 30.5 periods and a period length of 11 mm. It is designed to produce fundamental radiation at 4.6 keV, and, with a modest value of deflection parameter (K = 0.7 at 3.3 mm gap), enables higher harmonics to be used for a variety of experiments. C1 RIKEN, JAERI, SPring Project Team 8, Kamigori, Hyogo 67812, Japan. Brookhaven Natl Lab, Natl Synchrotron Light Source Dept, Upton, NY 11973 USA. RP Tanabe, T (reprint author), RIKEN, JAERI, SPring Project Team 8, Kamigori, Hyogo 67812, Japan. NR 6 TC 3 Z9 3 U1 0 U2 1 PU MUNKSGAARD INT PUBL LTD PI COPENHAGEN PA 35 NORRE SOGADE, PO BOX 2148, DK-1016 COPENHAGEN, DENMARK SN 0909-0495 J9 J SYNCHROTRON RADIAT JI J. Synchrot. Radiat. PD MAY 1 PY 1998 VL 5 BP 409 EP 411 DI 10.1107/S0909049597015707 PN 3 PG 3 WC Instruments & Instrumentation; Optics; Physics, Applied SC Instruments & Instrumentation; Optics; Physics GA 103UA UT WOS:000074975200063 PM 15263527 ER PT J AU Stefan, PM Tanabe, T Krinsky, S Rakowsky, G Solomon, L Kitamura, H AF Stefan, PM Tanabe, T Krinsky, S Rakowsky, G Solomon, L Kitamura, H TI Initial results from an in-vacuum undulator in the NSLS X-ray ring SO JOURNAL OF SYNCHROTRON RADIATION LA English DT Article; Proceedings Paper CT 6th International Conference on Synchrotron Radiation Instrumentation (SRI'97) CY AUG 04-08, 1997 CL HIMEJI, JAPAN SP Japan Atom Energy Res Inst (JAERI), Inst Phys & Chem Res (RIKEN) DE undulators; short periods; in-vacuum; small gaps AB A short-period in-vacuum undulator for the NSLS X-ray Ring has been developed in a collaboration between SPring-8 and the NSLS, and has achieved its project design goals during commissioning studies. The device is called IVUN (in-vacuum undulator) and employs magnet arrays (31 periods, with an 11 mm period) developed at SPring-8, while the requisite vacuum chamber and mechanical systems were developed at the NSLS. At a magnet gap of 3.3 mm, IVUN produces 4.6 keV radiation in the fundamental, with useful photon fluxes in both the second and third harmonics. The magnet gap is adjustable between 2 and 10 mm. A brief overview of IVUN is presented, together with initial commissioning results: the dependence of electron-beam lifetime and bremsstrahlung on magnet gap, and the output radiation spectrum. C1 Brookhaven Natl Lab, Natl Synchrotron Light Source Dept, Upton, NY 11973 USA. SPring 8 Project Team, Kamigori, Hyogo 67812, Japan. RP Stefan, PM (reprint author), Brookhaven Natl Lab, Natl Synchrotron Light Source Dept, Upton, NY 11973 USA. NR 7 TC 19 Z9 19 U1 2 U2 4 PU MUNKSGAARD INT PUBL LTD PI COPENHAGEN PA 35 NORRE SOGADE, PO BOX 2148, DK-1016 COPENHAGEN, DENMARK SN 0909-0495 J9 J SYNCHROTRON RADIAT JI J. Synchrot. Radiat. PD MAY 1 PY 1998 VL 5 BP 417 EP 419 DI 10.1107/S0909049597012995 PN 3 PG 3 WC Instruments & Instrumentation; Optics; Physics, Applied SC Instruments & Instrumentation; Optics; Physics GA 103UA UT WOS:000074975200066 PM 15263530 ER PT J AU Frank, M Mears, CA Labov, SE Hiller, LJ le Grand, JB Lindeman, MA Netel, H Chow, D Barfknecht, AT AF Frank, M Mears, CA Labov, SE Hiller, LJ le Grand, JB Lindeman, MA Netel, H Chow, D Barfknecht, AT TI Cryogenic high-resolution X-ray spectrometers for SR-XRF and microanalysis SO JOURNAL OF SYNCHROTRON RADIATION LA English DT Article; Proceedings Paper CT 6th International Conference on Synchrotron Radiation Instrumentation (SRI'97) CY AUG 04-08, 1997 CL HIMEJI, JAPAN SP Japan Atom Energy Res Inst (JAERI), Inst Phys & Chem Res (RIKEN) DE cryogenic detectors; low-temperature detectors; microcalorimeters; X-ray fluorescence; X-ray spectroscopy ID SUPERCONDUCTING TUNNEL JUNCTION; PARTICLE DETECTORS; SPECTROSCOPY AB Experimental results are presented obtained with a cryogenically cooled high-resolution X-ray spectrometer based on a 141 x 141 mu m Nb-Al-Al2O3-Al-Nb superconducting tunnel junction (STJ) detector in an SR-XRF demonstration experiment. STJ detectors can operate at count rates approaching those of semiconductor detectors while still providing a significantly better energy resolution for soft X-rays. By measuring fluorescence X-rays from samples containing transition metals and low-Z elements, an FWHM energy resolution of 6-15 eV for X-rays in the energy range 180-1100 eV has been obtained. The results show that, in the near future, STJ detectors may prove very useful in XRF and microanalysis applications. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. Conductus Inc, Sunnyvale, CA 94086 USA. RP Frank, M (reprint author), Univ Calif Lawrence Livermore Natl Lab, POB 808,L-418, Livermore, CA 94551 USA. RI Frank, Matthias/O-9055-2014 NR 15 TC 11 Z9 11 U1 0 U2 0 PU MUNKSGAARD INT PUBL LTD PI COPENHAGEN PA 35 NORRE SOGADE, PO BOX 2148, DK-1016 COPENHAGEN, DENMARK SN 0909-0495 J9 J SYNCHROTRON RADIAT JI J. Synchrot. Radiat. PD MAY 1 PY 1998 VL 5 BP 515 EP 517 DI 10.1107/S0909049597014465 PN 3 PG 3 WC Instruments & Instrumentation; Optics; Physics, Applied SC Instruments & Instrumentation; Optics; Physics GA 103UA UT WOS:000074975200099 PM 15263563 ER PT J AU Quintana, JPG AF Quintana, JPG TI SCIPE - a simple control interface protocol for experimenters SO JOURNAL OF SYNCHROTRON RADIATION LA English DT Article; Proceedings Paper CT 6th International Conference on Synchrotron Radiation Instrumentation (SRI'97) CY AUG 04-08, 1997 CL HIMEJI, JAPAN SP Japan Atom Energy Res Inst (JAERI), Inst Phys & Chem Res (RIKEN) DE control interface; detectors AB The simple control interface protocol for experimenters (SCIPE) used at Sector 5 of the Advanced Photon Source is presented. This interface provides a generic method for data-acquisition programs to control generic actuators and detectors on a synchrotron beamline. The implementation used by the DuPont-North-western-Dow Collaborative Access Team, based on readily available hardware, is also described. C1 Argonne Natl Lab, Adv Photon Source, Synchrotron Res Ctr, DND,CAT, Argonne, IL 60439 USA. RP Quintana, JPG (reprint author), Argonne Natl Lab, Adv Photon Source, Synchrotron Res Ctr, DND,CAT, Sector 5,Bldg 400,9700 S Cass Ave, Argonne, IL 60439 USA. NR 5 TC 3 Z9 3 U1 0 U2 1 PU MUNKSGAARD INT PUBL LTD PI COPENHAGEN PA 35 NORRE SOGADE, PO BOX 2148, DK-1016 COPENHAGEN, DENMARK SN 0909-0495 J9 J SYNCHROTRON RADIAT JI J. Synchrot. Radiat. PD MAY 1 PY 1998 VL 5 BP 600 EP 602 DI 10.1107/S0909049597012831 PN 3 PG 3 WC Instruments & Instrumentation; Optics; Physics, Applied SC Instruments & Instrumentation; Optics; Physics GA 103UA UT WOS:000074975200127 PM 15263591 ER PT J AU Shu, DM Ding, H Barraza, J Kuzay, TM Haeffner, D Ramanathan, M AF Shu, DM Ding, H Barraza, J Kuzay, TM Haeffner, D Ramanathan, M TI Smart X-ray beam position monitor system using artificial-intelligence methods for the Advanced Photon Source insertion-device beamlines SO JOURNAL OF SYNCHROTRON RADIATION LA English DT Article; Proceedings Paper CT 6th International Conference on Synchrotron Radiation Instrumentation (SRI'97) CY AUG 04-08, 1997 CL HIMEJI, JAPAN SP Japan Atom Energy Res Inst (JAERI), Inst Phys & Chem Res (RIKEN) DE XBPMs; artificial intelligence; Advanced Photon Source; insertion-device beamlines AB At the Advanced Photon Source (APS), each insertion-device (ID) beamline front end has two X-ray beam position monitors (XBPMs) to monitor the X-ray beam position for both vertical and horizontal directions. Performance challenges for a conventional photoemission-type XBPM during operations are contamination of the signal from the neighbouring bending-magnet sources and the sensitivity of the XBPM to the insertion-device gap variations Problems are exacerbated because users change the ID gap during their operations, and hence the percentage level of the contamination in the front-end XBPM signals varies. A smart XBPM system with a high-speed digital signal processor has been built at the Advanced Photon Source for the LD beamline front ends. The new version of the software, which uses an artificial-intelligence method, provides a self-learning and self-calibration capability to the smart XBPM system. The structure of and recent test results with the system are presented in this paper. C1 Argonne Natl Lab, Adv Photon Source, Expt Facil Div, Argonne, IL 60439 USA. RP Shu, DM (reprint author), Argonne Natl Lab, Adv Photon Source, Expt Facil Div, Argonne, IL 60439 USA. NR 6 TC 2 Z9 3 U1 4 U2 4 PU MUNKSGAARD INT PUBL LTD PI COPENHAGEN PA 35 NORRE SOGADE, PO BOX 2148, DK-1016 COPENHAGEN, DENMARK SN 0909-0495 J9 J SYNCHROTRON RADIAT JI J. Synchrot. Radiat. PD MAY 1 PY 1998 VL 5 BP 632 EP 635 DI 10.1107/S0909049597017056 PN 3 PG 4 WC Instruments & Instrumentation; Optics; Physics, Applied SC Instruments & Instrumentation; Optics; Physics GA 103UA UT WOS:000074975200138 PM 15263602 ER PT J AU Shu, DM Kuzay, TM Fang, Y Barraza, J Cundiff, T AF Shu, DM Kuzay, TM Fang, Y Barraza, J Cundiff, T TI Synthetic diamond-based position-sensitive photoconductive detector development for the Advanced Photon Source SO JOURNAL OF SYNCHROTRON RADIATION LA English DT Article; Proceedings Paper CT 6th International Conference on Synchrotron Radiation Instrumentation (SRI'97) CY AUG 04-08, 1997 CL HIMEJI, JAPAN SP Japan Atom Energy Res Inst (JAERI), Inst Phys & Chem Res (RIKEN) DE beam-position monitors; beam profiler; images; X-rays; CVD diamond ID RAY; MONITOR; TESTS AB A novel X-ray beam-position detection device that we call a position-sensitive photoconductive detector (PSPCD) is designed to have synthetic diamond as its substrate material. We proved that it is feasible to use synthetic diamond to make a hard X-ray position-sensitive detector based on the photoconductivity principle and that it acts as a solid-state ion chamber. Experiments on different PSPCD samples using synthetic diamond with a high-heat-flux white undulator beam, as well as with monochromatic hard X-ray beams, have been performed at the Advanced Photon Source. Recent test results with the PSPCD in the quadrant configuration as an X-ray beam-position monitor and in a multipixel array as an X-ray beam profiler are presented in this paper. C1 Argonne Natl Lab, Adv Photon Source, Expt Facil Div, Argonne, IL 60439 USA. RP Shu, DM (reprint author), Argonne Natl Lab, Adv Photon Source, Expt Facil Div, Argonne, IL 60439 USA. NR 12 TC 10 Z9 10 U1 0 U2 0 PU MUNKSGAARD INT PUBL LTD PI COPENHAGEN PA 35 NORRE SOGADE, PO BOX 2148, DK-1016 COPENHAGEN, DENMARK SN 0909-0495 J9 J SYNCHROTRON RADIAT JI J. Synchrot. Radiat. PD MAY 1 PY 1998 VL 5 BP 636 EP 638 DI 10.1107/S0909049597019778 PN 3 PG 3 WC Instruments & Instrumentation; Optics; Physics, Applied SC Instruments & Instrumentation; Optics; Physics GA 103UA UT WOS:000074975200139 PM 15263603 ER PT J AU Siddons, DP AF Siddons, DP TI Microcontroller-based servo for two-crystal X-ray monochromators SO JOURNAL OF SYNCHROTRON RADIATION LA English DT Article; Proceedings Paper CT 6th International Conference on Synchrotron Radiation Instrumentation (SRI'97) CY AUG 04-08, 1997 CL HIMEJI, JAPAN SP Japan Atom Energy Res Inst (JAERI), Inst Phys & Chem Res (RIKEN) DE microcontrollers; two-crystal X-ray monochromators; PIC series ID SYSTEM AB Microcontrollers have become increasingly easy to incorporate into instruments as the architectures and support tools have developed. The PIC series is particularly easy to use, and this paper describes a controller used to stabilize the output of a two-crystal X-ray monochromator at a given offset from its peak intensity position, as such monochromators are generally used. C1 Brookhaven Natl Lab, Natl Synchrotron Light Source Dept, Upton, NY 11973 USA. RP Siddons, DP (reprint author), Brookhaven Natl Lab, Natl Synchrotron Light Source Dept, Upton, NY 11973 USA. NR 3 TC 1 Z9 1 U1 0 U2 0 PU MUNKSGAARD INT PUBL LTD PI COPENHAGEN PA 35 NORRE SOGADE, PO BOX 2148, DK-1016 COPENHAGEN, DENMARK SN 0909-0495 J9 J SYNCHROTRON RADIAT JI J. Synchrot. Radiat. PD MAY 1 PY 1998 VL 5 BP 685 EP 686 DI 10.1107/S0909049597017111 PN 3 PG 2 WC Instruments & Instrumentation; Optics; Physics, Applied SC Instruments & Instrumentation; Optics; Physics GA 103UA UT WOS:000074975200155 PM 15263619 ER PT J AU Hasegawa, Y Ueji, Y Okitsu, K Ablett, JM Siddons, DP Amemiya, Y AF Hasegawa, Y Ueji, Y Okitsu, K Ablett, JM Siddons, DP Amemiya, Y TI Transmission-type X-ray linear polarizer with perfect crystals SO JOURNAL OF SYNCHROTRON RADIATION LA English DT Article; Proceedings Paper CT 6th International Conference on Synchrotron Radiation Instrumentation (SRI'97) CY AUG 04-08, 1997 CL HIMEJI, JAPAN SP Japan Atom Energy Res Inst (JAERI), Inst Phys & Chem Res (RIKEN) DE X-ray polarizers; perfect crystals; X-ray polarimeters; dynamical theory of diffraction ID COBALT AB Even though conventional X-ray polarizers with multiple-reflection channel-cut structures perform well, they suffer from the disadvantage that the polarized beam is non-stationary as the energy is scanned. In this paper the possibility of using a thin Bragg reflector as a polarizing filter is investigated, so that the transmitted beam (rather than the Bragg-reflected beam) is used. Consequently, the position and direction of the transmitted beam are unchanged as the energy is changed, or even when the polarization direction to be filtered out is changed. Theoretical considerations as well as experimental results on the performance characteristics of the proposed transmission-type X-ray linear polarizer are presented. A polarization ratio, defined as I-H/I-V, higher than 10(5) was obtained. C1 Univ Tokyo, Engn Res Inst, Bunkyo Ku, Tokyo 113, Japan. Grad Univ Adv Studies, Tsukuba, Ibaraki 305, Japan. Natl Res Lab Metrol, Tsukuba, Ibaraki 305, Japan. Brookhaven Natl Lab, NSLS, Upton, NY 11973 USA. RP Hasegawa, Y (reprint author), Univ Tokyo, Engn Res Inst, Bunkyo Ku, Tokyo 113, Japan. NR 11 TC 1 Z9 1 U1 1 U2 1 PU MUNKSGAARD INT PUBL LTD PI COPENHAGEN PA 35 NORRE SOGADE, PO BOX 2148, DK-1016 COPENHAGEN, DENMARK SN 0909-0495 J9 J SYNCHROTRON RADIAT JI J. Synchrot. Radiat. PD MAY 1 PY 1998 VL 5 BP 738 EP 740 DI 10.1107/S0909049597019560 PN 3 PG 3 WC Instruments & Instrumentation; Optics; Physics, Applied SC Instruments & Instrumentation; Optics; Physics GA 103UA UT WOS:000074975200173 PM 15263637 ER PT J AU Howells, MR Anspach, J Bender, J AF Howells, MR Anspach, J Bender, J TI An assessment of approximating aspheres with more easily manufactured surfaces SO JOURNAL OF SYNCHROTRON RADIATION LA English DT Article; Proceedings Paper CT 6th International Conference on Synchrotron Radiation Instrumentation (SRI'97) CY AUG 04-08, 1997 CL HIMEJI, JAPAN SP Japan Atom Energy Res Inst (JAERI), Inst Phys & Chem Res (RIKEN) DE grazing-incidence mirrors; aspheres; approximation; optical fabrication AB In designing optical systems for synchrotron radiation, one is often led to conclude that optimal performance can be obtained from optical surfaces described by conic sections of revolution, usually paraboloids and ellipsoids. The resulting design can lead to prescriptions for three-dimensional optical surfaces that are difficult to fabricate accurately. Under some circumstances satisfactory system performance can be achieved through the use of more easily manufactured surfaces such as cylinders, cones, bent cones, toroids and elliptical cylinders. These surfaces often have the additional benefits of scalability to large aperture, lower surface roughness and improved surface figure accuracy. In this paper we explore some of the conditions under which these more easily manufactured surfaces can be utilized without sacrificing performance. C1 Boeing N Amer, Rocketdyne Div, Albuquerque, NM 87107 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Adv Light Source, Berkeley, CA 94720 USA. RP Howells, MR (reprint author), Boeing N Amer, Rocketdyne Div, 2511C Broadbent Pkwy NE, Albuquerque, NM 87107 USA. NR 3 TC 1 Z9 1 U1 0 U2 1 PU MUNKSGAARD INT PUBL LTD PI COPENHAGEN PA 35 NORRE SOGADE, PO BOX 2148, DK-1016 COPENHAGEN, DENMARK SN 0909-0495 J9 J SYNCHROTRON RADIAT JI J. Synchrot. Radiat. PD MAY 1 PY 1998 VL 5 BP 814 EP 816 DI 10.1107/S0909049597018633 PN 3 PG 3 WC Instruments & Instrumentation; Optics; Physics, Applied SC Instruments & Instrumentation; Optics; Physics GA 103UA UT WOS:000074975200198 PM 15263662 ER PT J AU Shu, DM Alp, EE Barraza, J Kuzay, TM Mooney, T AF Shu, DM Alp, EE Barraza, J Kuzay, TM Mooney, T TI Optical design for laser Doppler angular encoder with sub-nrad sensitivity SO JOURNAL OF SYNCHROTRON RADIATION LA English DT Article; Proceedings Paper CT 6th International Conference on Synchrotron Radiation Instrumentation (SRI'97) CY AUG 04-08, 1997 CL HIMEJI, JAPAN SP Japan Atom Energy Res Inst (JAERI), Inst Phys & Chem Res (RIKEN) DE angular encoders; nrad sensitivity; optical design AB A novel laser angular-encoder system has been developed based on the principles of radar, the Doppler effect, optical heterodyning and self-aligning multiple-reflection optics. Using this novel three-dimensional multiple-reflection optical path, an increase in resolution of 10 to 20 times has been reached compared with commercially available laser Doppler displacement meters or laser interferometer systems. With the new angular encoder, sub-mad resolution has been attained in the 8 degrees measuring range in a compact set-up [about 60 (H) x 150 (W) x 370mm (L)] for high-energy-resolution applications at the Advanced Photon Source undulator beamline 3-ID. C1 Argonne Natl Lab, Adv Photon Source, Expt Facil Div, Argonne, IL 60439 USA. RP Shu, DM (reprint author), Argonne Natl Lab, Adv Photon Source, Expt Facil Div, Argonne, IL 60439 USA. NR 4 TC 1 Z9 1 U1 0 U2 1 PU MUNKSGAARD INT PUBL LTD PI COPENHAGEN PA 35 NORRE SOGADE, PO BOX 2148, DK-1016 COPENHAGEN, DENMARK SN 0909-0495 J9 J SYNCHROTRON RADIAT JI J. Synchrot. Radiat. PD MAY 1 PY 1998 VL 5 BP 826 EP 828 DI 10.1107/S0909049597020141 PN 3 PG 3 WC Instruments & Instrumentation; Optics; Physics, Applied SC Instruments & Instrumentation; Optics; Physics GA 103UA UT WOS:000074975200202 PM 15263666 ER PT J AU Nanba, T Muneyasu, M Hiraoka, N Kaga, S Williams, GP Shimomura, O Adachi, T AF Nanba, T Muneyasu, M Hiraoka, N Kaga, S Williams, GP Shimomura, O Adachi, T TI Phase transitions of CdS microcrystals under high pressure SO JOURNAL OF SYNCHROTRON RADIATION LA English DT Article; Proceedings Paper CT 6th International Conference on Synchrotron Radiation Instrumentation (SRI'97) CY AUG 04-08, 1997 CL HIMEJI, JAPAN SP Japan Atom Energy Res Inst (JAERI), Inst Phys & Chem Res (RIKEN) DE phase transitions; CdS microcrystal; high-pressure experiments; far-IR transmission; X-ray powder diffraction AB The experiment under high pressure using a diamond anvil cell (DAC) requires the utilization of synchrotron radiation. High-pressure experiments were performed using a DAC on CdS microcrystals, both in the far-IF and in the X-ray regions, in order to study the lattice dynamics and lattice stability concerned with the phase transitions. From these experiments, experimental evidence is presented indicating that a CdS microcrystal of smaller diameter shows a higher transition pressure for lattice transformation under pressure. The origin of such an increase in the transition pressure in the microcrystals is discussed in relation to the surface tension. C1 Kobe Univ, Fac Sci, Nada Ku, Kobe, Hyogo 657, Japan. Brookhaven Natl Lab, NSLS, Upton, NY 11973 USA. KEK PPring, Tsukuba, Ibaraki 305, Japan. RP Kobe Univ, Fac Sci, Nada Ku, Kobe, Hyogo 657, Japan. EM nanba@phys.kobe-u.ac.jp NR 6 TC 0 Z9 0 U1 1 U2 6 PU INT UNION CRYSTALLOGRAPHY PI CHESTER PA 2 ABBEY SQ, CHESTER, CH1 2HU, ENGLAND SN 1600-5775 J9 J SYNCHROTRON RADIAT JI J. Synchrot. Radiat. PD MAY 1 PY 1998 VL 5 BP 1016 EP 1019 DI 10.1107/S0909049597016002 PN 3 PG 4 WC Instruments & Instrumentation; Optics; Physics, Applied SC Instruments & Instrumentation; Optics; Physics GA 103UA UT WOS:000074975200266 PM 15263730 ER PT J AU Warwick, T Ade, H Cerasari, S Denlinger, J Franck, K Garcia, A Hayakawa, S Hitchcock, A Kikuma, J Klingler, S Kortright, J Morisson, G Moronne, M Rightor, E Rotenberg, E Seal, S Shin, HJ Steele, WF Tonner, BP AF Warwick, T Ade, H Cerasari, S Denlinger, J Franck, K Garcia, A Hayakawa, S Hitchcock, A Kikuma, J Klingler, S Kortright, J Morisson, G Moronne, M Rightor, E Rotenberg, E Seal, S Shin, HJ Steele, WF Tonner, BP TI Development of scanning X-ray microscopes for materials science spectromicroscopy at the Advanced Light Source SO JOURNAL OF SYNCHROTRON RADIATION LA English DT Article; Proceedings Paper CT 6th International Conference on Synchrotron Radiation Instrumentation (SRI'97) CY AUG 04-08, 1997 CL HIMEJI, JAPAN SP Japan Atom Energy Res Inst (JAERI), Inst Phys & Chem Res (RIKEN) DE spectromicroscopy; NEXAFS; XPS; zone plates ID CORE AB The development of two zone-plate microscopes for X-ray spectroscopic analysis of materials is described. This pair of instruments will provide imaging NEXAFS analysis of samples in transmission at atmospheric pressure and imaging XPS and NEXAFS analysis of sample surfaces in a UHV environment. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. N Carolina State Univ, Dept Phys, Raleigh, NC 27695 USA. Univ Trieste, Trieste, Italy. Univ Michigan, Ann Arbor, MI 48109 USA. Univ Tokyo, Sch Engn, Tokyo, Japan. McMaster Univ, Dept Chem, Hamilton, ON, Canada. Asahi Chem Ind Co Ltd, Fuji, Shizuoka 416, Japan. DOW Chem, Freeport, TX USA. POSTECH, Pohang Accelerator Lab, Pohang, South Korea. Univ Wisconsin, Dept Phys, Milwaukee, WI USA. RP Warwick, T (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. EM warwick@lbl.gov RI Rotenberg, Eli/B-3700-2009; Hayakawa, Shinjiro/B-1840-2010; Ade, Harald/E-7471-2011; OI Rotenberg, Eli/0000-0002-3979-8844; Hayakawa, Shinjiro/0000-0002-4187-6928; Garcia-Garcia, Adrian/0000-0002-5121-9032 NR 11 TC 23 Z9 23 U1 0 U2 3 PU MUNKSGAARD INT PUBL LTD PI COPENHAGEN PA 35 NORRE SOGADE, PO BOX 2148, DK-1016 COPENHAGEN, DENMARK SN 0909-0495 J9 J SYNCHROTRON RADIAT JI J. Synchrot. Radiat. PD MAY 1 PY 1998 VL 5 BP 1090 EP 1092 DI 10.1107/S0909049597014283 PN 3 PG 3 WC Instruments & Instrumentation; Optics; Physics, Applied SC Instruments & Instrumentation; Optics; Physics GA 103UA UT WOS:000074975200291 PM 15263755 ER PT J AU Hirai, A Takemoto, K Nishino, K Watanabe, N Anderson, E Attwood, D Kern, D Hettwer, M Rudolph, D Aoki, S Nakayama, Y Kihara, H AF Hirai, A Takemoto, K Nishino, K Watanabe, N Anderson, E Attwood, D Kern, D Hettwer, M Rudolph, D Aoki, S Nakayama, Y Kihara, H TI Imaging soft X-ray microscope at Rits Synchrotron Radiation Center SO JOURNAL OF SYNCHROTRON RADIATION LA English DT Article; Proceedings Paper CT 6th International Conference on Synchrotron Radiation Instrumentation (SRI'97) CY AUG 04-08, 1997 CL HIMEJI, JAPAN SP Japan Atom Energy Res Inst (JAERI), Inst Phys & Chem Res (RIKEN) DE X-ray microscope; zone plate; Rits SR Center AB An imaging soft X-ray microscope with zone plates has been installed at Rits SR Center (Ritsumeikan University, Kusatsu, Japan). With this microscope, specimens were set in air, which made it possible to investigate the specimens without breaking the vacuum of the microscope. The specimens can be prefocused with an optical microscope. Dry and wet biospecimens in air were observed. A new optical system was designed to improve the resolution. C1 Ritsumeikan Univ, Dept Phys, Shiga 52577, Japan. Kansai Med Univ, Phys Lab, Hirakata, Osaka 573, Japan. Univ Tsukuba, Inst Appl Phys, Tsukuba, Ibaraki 305, Japan. Univ Calif Berkeley, Lawrence Berkeley Lab, Ctr Xray Opt, Berkeley, CA 94720 USA. Univ Tubingen, Inst Angew Phys, Tubingen 1, Germany. Georg August Universitat, Forsch Einrichtung Rontgenphys, D-37073 Gottingen, Germany. RP Hirai, A (reprint author), Ritsumeikan Univ, Dept Phys, Shiga 52577, Japan. EM fpc30013@sec.ritsumei.ac.jp NR 11 TC 12 Z9 12 U1 0 U2 0 PU MUNKSGAARD INT PUBL LTD PI COPENHAGEN PA 35 NORRE SOGADE, PO BOX 2148, DK-1016 COPENHAGEN, DENMARK SN 0909-0495 J9 J SYNCHROTRON RADIAT JI J. Synchrot. Radiat. PD MAY 1 PY 1998 VL 5 BP 1102 EP 1104 DI 10.1107/S0909049597018529 PN 3 PG 3 WC Instruments & Instrumentation; Optics; Physics, Applied SC Instruments & Instrumentation; Optics; Physics GA 103UA UT WOS:000074975200295 PM 15263759 ER PT J AU Reifman, J Feldman, EE AF Reifman, J Feldman, EE TI Identification and control of NOx emissions using neural networks SO JOURNAL OF THE AIR & WASTE MANAGEMENT ASSOCIATION LA English DT Article AB We investigate the application of two classes of artificial neural networks for the identification and control of discrete-time nonlinear dynamical systems. A fully connected recurrent network is used for process identification, and a multilayer feedforward network is used for process control. The two neural networks are arranged in series for closed-loop control of oxides of nitrogen (NOx) emissions of a simplified representation of a dynamical system. Plant data from one of Commonwealth Edison's coal-fired power plants are used for testing the approach, with initial results indicating that the method is feasible. However, further work is required to determine whether the method remains feasible as the number of state variables and control variables are increased. C1 Argonne Natl Lab, Reactor Anal Div, Argonne, IL 60439 USA. RP Reifman, J (reprint author), Argonne Natl Lab, Reactor Anal Div, 9700 S Cass Ave, Argonne, IL 60439 USA. NR 12 TC 4 Z9 5 U1 0 U2 1 PU AIR & WASTE MANAGEMENT ASSOC PI PITTSBURGH PA ONE GATEWAY CENTER, THIRD FL, PITTSBURGH, PA 15222 USA SN 1047-3289 J9 J AIR WASTE MANAGE JI J. Air Waste Manage. Assoc. PD MAY PY 1998 VL 48 IS 5 BP 408 EP 417 PG 10 WC Engineering, Environmental; Environmental Sciences; Meteorology & Atmospheric Sciences SC Engineering; Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences GA ZN673 UT WOS:000073670200003 ER PT J AU Tolic, LP Harms, AC Anderson, GA Smith, RD Willie, A Jorns, MS AF Tolic, LP Harms, AC Anderson, GA Smith, RD Willie, A Jorns, MS TI Electrospray ionization mass spectrometry characterization of heterotetrameric sarcosine oxidase SO JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY LA English DT Article ID NONCOVALENT INTERACTIONS; ION ACCUMULATION; RESOLUTION; OLIGONUCLEOTIDES; COMPLEXES; PROTEINS; ASSOCIATIONS; DISSOCIATION; BIOPOLYMERS; PEPTIDES AB Electrospray ionization (ESI) Fourier transform ion cyclotron resonance (FTICR) mass spectrometry has been used to characterize heterotetrameric corynebacterial sarcosine oxidase. By using a conventional quadrupole mass spectrometer, no spectra for the intact complex could be obtained (i.e., electrospraying protein at neutral PH), but spectra showing the four protein subunits were obtained when electrospraying from acidic solution. Initial low resolution ESI-FTICR mass spectra of the intact heterotetramer revealed a typical narrow charge state distribution in the range 6000 < m/z < 9000, consistent with retention of a compact structure in the gas phase, and gave a mass measurement about 1000 u higher than predicted. Efficient in-trap clean up, based upon low energy collisionally induced dissociation of adducts, allowed significant improvement in mass measurement accuracy. The present results represent the largest heteromultimeric protein complex successfully analyzed using FTICR mass spectrometry, and clearly illustrate the importance of sample clean up methods for large molecule characterization. (C) 1998 American Society for Mass Spectrometry. C1 Pacific NW Lab, Environm Mol Sci Lab, Richland, WA 99352 USA. Allegheny Univ Hlth Sci, Dept Biochem, Philadelphia, PA 19102 USA. RP Smith, RD (reprint author), Pacific NW Lab, Environm Mol Sci Lab, POB 999,Mail Stop K8-98, Richland, WA 99352 USA. EM rd_smith@pnl.gov RI Smith, Richard/J-3664-2012 OI Smith, Richard/0000-0002-2381-2349 NR 53 TC 3 Z9 3 U1 0 U2 0 PU ELSEVIER SCIENCE INC PI NEW YORK PA 655 AVENUE OF THE AMERICAS, NEW YORK, NY 10010 USA SN 1044-0305 J9 J AM SOC MASS SPECTR JI J. Am. Soc. Mass Spectrom. PD MAY PY 1998 VL 9 IS 5 BP 510 EP 515 DI 10.1016/S1044-0305(98)00011-7 PG 6 WC Chemistry, Analytical; Chemistry, Physical; Spectroscopy SC Chemistry; Spectroscopy GA ZJ536 UT WOS:000073226600008 ER PT J AU Ryan, MP Laycock, NJ Newman, RC Isaacs, HS AF Ryan, MP Laycock, NJ Newman, RC Isaacs, HS TI The pitting behavior of iron-chromium thin film alloys in hydrochloric acid SO JOURNAL OF THE ELECTROCHEMICAL SOCIETY LA English DT Article ID FE-CR ALLOYS; STAINLESS-STEEL; LOCALIZED CORROSION; CHLORIDE SOLUTION; INITIATION; DISSOLUTION; PASSIVATION; INCLUSIONS; BREAKDOWN; MECHANISM AB The pitting behavior of a range of iron-chromium thin film alloys which are sulfide-free has been studied by electrochemical methods coupled with in situ optical microscopy. In 0.5 M HCl, iron-chromium alloys with > similar to 16 atom % chromium do not pit at any potential, whereas alloys with < similar to 16 atom % chromium pit at approximately +500 mV standard calomel electrode. The sharp transition is believed to be associated with the existence of a critical size of iron cluster which act as pit nucleation sites. This is modeled by the achievement of a high density percolation condition for iron in the body-centered cubic alloy. The pits propagate under remnants of the passive film as two-dimensional disks, with current densities up to 80 A cm(-2) and simultaneous hydrogen evolution. C1 Brookhaven Natl Lab, Dept Appl Sci, Upton, NY 11973 USA. Univ Manchester, Inst Sci & Technol, Ctr Corros & Protect, Manchester M60 1QD, Lancs, England. RP Brookhaven Natl Lab, Dept Appl Sci, Upton, NY 11973 USA. OI Ryan, Mary/0000-0001-8582-3003 NR 35 TC 23 Z9 23 U1 2 U2 12 PU ELECTROCHEMICAL SOC INC PI PENNINGTON PA 65 SOUTH MAIN STREET, PENNINGTON, NJ 08534 USA SN 0013-4651 EI 1945-7111 J9 J ELECTROCHEM SOC JI J. Electrochem. Soc. PD MAY PY 1998 VL 145 IS 5 BP 1566 EP 1571 DI 10.1149/1.1838519 PG 6 WC Electrochemistry; Materials Science, Coatings & Films SC Electrochemistry; Materials Science GA ZJ387 UT WOS:000073209800028 ER PT J AU Ferry, A Doeff, MM De Jonghe, LC AF Ferry, A Doeff, MM De Jonghe, LC TI Transport property and Raman spectroscopic studies of the polymer electrolyte system P(EO)(n)-NaTFSI SO JOURNAL OF THE ELECTROCHEMICAL SOCIETY LA English DT Article ID ALKALI-METAL SALTS; TRANSFERENCE NUMBER; IONIC-CONDUCTIVITY; SODIUM TRIFLATE; COMPLEXES; LITHIUM; RELAXATION; DIFFUSION; CELLS; ETHER AB Concentration dependences of a complete set of ionic transport properties are reported for the binary solid polymeric ion conductor poly(ethylene-oxide) [P(EO)], complexed with NaTFSI, [TFSI = (bis)trifluoromethanesulfonate imide, (CF3SO2)(2)N]. Measured transport properties include the ionic conductivity to), the differential salt diffusion coefficient (D-s), and the cationic transference number (t(+)(0)). To measure t(+)(0), a recently developed technique based on concentrated solution theory is used. Under this framework no assumptions need to be made concerning Ideality of the electrolytic solution. We find that for the P(EO)(pi)-NaTFSI complexes the ionic conductivities, and differential salt diffusion coefficients are much higher than those of the previously reported P(EO)(pi)-NaCF3SO3 system. D-s also varies less with complex composition in concentrated solutions. Interestingly, the cationic transference numbers are found to be negative over a wide concentration range, i.e., t(+)(0) decreases with increasing salt concentration and reaches a low of -1.15 +/- 0.25 at a composition corresponding to an ether-oxygen to sodium-ion ratio of 7:1. This implies that the cationic current is mainly carried by complexed ions. Complementary Raman spectroscopic studies directly probing cation-anion and cation-polymer molecular interactions show that extensive interionic interactions occur in this system. C1 Umea Univ, Dept Expt Phys, S-90187 Umea, Sweden. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. RP Ferry, A (reprint author), Monash Univ, Clayton, Vic 3168, Australia. RI Doeff, Marca/G-6722-2013 OI Doeff, Marca/0000-0002-2148-8047 NR 56 TC 46 Z9 48 U1 1 U2 15 PU ELECTROCHEMICAL SOC INC PI PENNINGTON PA 10 SOUTH MAIN STREET, PENNINGTON, NJ 08534 USA SN 0013-4651 J9 J ELECTROCHEM SOC JI J. Electrochem. Soc. PD MAY PY 1998 VL 145 IS 5 BP 1586 EP 1592 DI 10.1149/1.1838522 PG 7 WC Electrochemistry; Materials Science, Coatings & Films SC Electrochemistry; Materials Science GA ZJ387 UT WOS:000073209800031 ER PT J AU Guan, J Dorris, SE Balachandran, U Liu, M AF Guan, J Dorris, SE Balachandran, U Liu, M TI The effects of dopants and A : B site nonstoichiometry on properties of perovskite-type proton conductors SO JOURNAL OF THE ELECTROCHEMICAL SOCIETY LA English DT Article ID CERATE PEROVSKITES; CONDUCTIVITY; CERAMICS; OXIDES; BACEO3; FUEL AB Investigations of perovskite-type BaCeO3 and SrCeO3 with various dopants (Y, Gd, Nd, and Ni) indicate that their microstructures and electrical properties are strongly influenced by the type and amount of dopants. Grain growth and densification of sintered samples are influenced by dopant level and A:B site nonstoichiometry. The conductivity of BaCe1-xYxO3-delta increases with the yttrium content in hydrogen and wet Ar, and exhibits a maximum in oxygen at an yttrium content of 10 to 20%. BaCe0.8Y0.2O3-delta, has the highest conductivity in a hydrogen atmosphere: similar to 1.54 x 10(-2) Omega(-1) cm(-1) at 600 degrees C, and similar to 4.16 x 10(-2) Omega(-1) cm(-1) at 800 degrees C. The effect of BaO excess depends on the concentration of dopant. Compared with BaCe0.95Y0.05O3-delta, doped BaCeO3 with BaO excess (BaO.0.90CeO(2).0.025Y(2)O(3)) has a higher total conductivity in all atmospheres studied (O-2, H-2, and wet Ar), whereas the conductivity of BaCeO3 with excess BaO (BaO.0.85CeO(2).0.05Y(2)O(3)) is lower than that of BaCe0.9Y0.1O3-delta. BaCeO3 based materials have higher conductivities than those of SrCeO3 based materials, whereas SrCeO3 based materials show higher proton transference numbers. C1 Argonne Natl Lab, Div Energy Technol, Argonne, IL 60439 USA. Georgia Inst Technol, Sch Mat Sci & Engn, Atlanta, GA 30332 USA. RP Guan, J (reprint author), Argonne Natl Lab, Div Energy Technol, 9700 S Cass Ave, Argonne, IL 60439 USA. RI Liu, Meilin/E-5782-2010 OI Liu, Meilin/0000-0002-6188-2372 NR 32 TC 61 Z9 61 U1 3 U2 24 PU ELECTROCHEMICAL SOC INC PI PENNINGTON PA 10 SOUTH MAIN STREET, PENNINGTON, NJ 08534 USA SN 0013-4651 J9 J ELECTROCHEM SOC JI J. Electrochem. Soc. PD MAY PY 1998 VL 145 IS 5 BP 1780 EP 1786 DI 10.1149/1.1838557 PG 7 WC Electrochemistry; Materials Science, Coatings & Films SC Electrochemistry; Materials Science GA ZJ387 UT WOS:000073209800066 ER PT J AU Robbert, PS Geisler, H Ventrice, CA van Ek, J Chaturvedi, S Rodriguez, JA Kuhn, M Diebold, U AF Robbert, PS Geisler, H Ventrice, CA van Ek, J Chaturvedi, S Rodriguez, JA Kuhn, M Diebold, U TI Novel electronic and magnetic properties of ultrathin chromium oxide films grown on Pt(111) SO JOURNAL OF VACUUM SCIENCE & TECHNOLOGY A LA English DT Article; Proceedings Paper CT 44th American-Vacuum-Society Symposium on Flat Panel Displays, Micromechanical Systems, and Quantitative Surface and Analysis CY OCT 20-24, 1997 CL SAN JOSE, CA SP Amer Vacuum Soc ID SCANNING-TUNNELING-MICROSCOPY; HALF-METALLIC FERROMAGNET; SURFACE; CRO2; CR2O3(111)/CR(110); SPECTROSCOPY; AU(111); NIO AB The growth of epitaxial metal-oxide films on lattice-mismatched metal substrates often results in the formation of unique overlayer structures. In particular, epitaxial chromium oxide films grown on Pt(111) exhibit a p(2 x 2) symmetry through the first two monolayers of growth which is followed by a (root 3 x root 3)R30 degrees phase that is attributed to the growth of a Cr2O3(0001) overlayer. Ultraviolet photoelectron spectroscopy measurements have been performed on the CrOx/Pt(111) system. The electronic structures of CrO2, Cr2O3, and Cr3O4 were calculated using the linear muffin-tin orbital method in the atomic sphere approximation. Comparison of the photoemission valence band spectra with the calculated density of states indicates that the CrOx initially grows in a cubic spinel Cr3O4 structure. Beyond similar to 0.2 monolayers, the metallic behavior of the CrOx overlayer begins a transformation to an insulating state. The measured valence emission for the p(2 x 2) phase beyond similar to 0.2 monolayers is more consistent with either a gamma-Cr2O3(111) overlayer or possibly a reconstructed Cr2O3(0001) overlayer. (C) 1998 American Vacuum Society. C1 Univ New Orleans, Dept Phys, New Orleans, LA 70148 USA. Brookhaven Natl Lab, Dept Chem, Upton, NY 11973 USA. Seagate Technol, Bloomington, MN 55435 USA. Tulane Univ, Dept Phys, New Orleans, LA 70118 USA. RP Univ New Orleans, Dept Phys, New Orleans, LA 70148 USA. EM CAVPH@uno.edu; johannes_van_ek@notes.seagate.com; rodrigez@bnl.gov; diebold@mailhost.tcs.tulane.edu RI Diebold, Ulrike/A-3681-2010 OI Diebold, Ulrike/0000-0003-0319-5256 NR 21 TC 30 Z9 30 U1 1 U2 13 PU A V S AMER INST PHYSICS PI MELVILLE PA STE 1 NO 1, 2 HUNTINGTON QUADRANGLE, MELVILLE, NY 11747-4502 USA SN 0734-2101 EI 1520-8559 J9 J VAC SCI TECHNOL A JI J. Vac. Sci. Technol. A PD MAY-JUN PY 1998 VL 16 IS 3 BP 990 EP 995 DI 10.1116/1.581283 PN 1 PG 6 WC Materials Science, Coatings & Films; Physics, Applied SC Materials Science; Physics GA ZT991 UT WOS:000074150400018 ER PT J AU Ferris, KF Wang, LQ AF Ferris, KF Wang, LQ TI Electronic structure calculations of small molecule adsorbates on (110) and (100) TiO2 SO JOURNAL OF VACUUM SCIENCE & TECHNOLOGY A-VACUUM SURFACES AND FILMS LA English DT Article; Proceedings Paper CT 44th American-Vacuum-Society Symposium on Flat Panel Displays, Micromechanical Systems, and Quantitative Surface and Analysis CY OCT 20-24, 1997 CL SAN JOSE, CALIFORNIA SP Amer Vacuum Soc ID VALENCE BASIS-SETS; ORBITAL METHODS; 1ST-ROW ELEMENTS; 2ND-ROW ELEMENTS; ADSORPTION; WATER; TIO2(110); SURFACES; H2O; HYDROGEN AB Electronic structure calculations were performed for water and methanol adsorbed onto model structures for ideal (110) and (100) rutile TiO2 surfaces. Both molecular and dissociated forms of water and methanol were examined for each surface, and the reaction coordinate for interconversion of the two forms. Our results indicate a strong thermodynamic favor for the dissociative form in each case; however, there is a potential energetic barrier to proton transfer to generate the dissociative form for the (110) surface. Based upon the structural differences between these surfaces, it is proposed that multiple hydrogen bonding interactions with the adsorbed species facilitate proton transfer. (C) 1998 American Vacuum Society. C1 Pacific NW Lab, Mat & Chem Sci Ctr, Richland, WA 99352 USA. RP Ferris, KF (reprint author), Pacific NW Lab, Mat & Chem Sci Ctr, POB 999, Richland, WA 99352 USA. EM kim@darter.pnl.gov NR 26 TC 38 Z9 39 U1 0 U2 5 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0734-2101 J9 J VAC SCI TECHNOL A JI J. Vac. Sci. Technol. A-Vac. Surf. Films PD MAY-JUN PY 1998 VL 16 IS 3 BP 956 EP 960 DI 10.1116/1.581219 PN 1 PG 5 WC Materials Science, Coatings & Films; Physics, Applied SC Materials Science; Physics GA ZT991 UT WOS:000074150400011 ER PT J AU Bedrossian, PJ de la Rubia, TD AF Bedrossian, PJ de la Rubia, TD TI Surface segregation of low-energy ion-induced defects in Si SO JOURNAL OF VACUUM SCIENCE & TECHNOLOGY A-VACUUM SURFACES AND FILMS LA English DT Article; Proceedings Paper CT 44th American-Vacuum-Society Symposium on Flat Panel Displays, Micromechanical Systems, and Quantitative Surface and Analysis CY OCT 20-24, 1997 CL SAN JOSE, CALIFORNIA SP Amer Vacuum Soc ID DIFFRACTION; DYNAMICS; GROWTH AB Surfaces of Si(100) irradiated at 110 K with 5 keV He ions under ultrahigh vacuum conditions and subsequently annealed isochronally display abrupt healing of the radiation-induced surface roughness at 160 K. Smoothening also occurs at 160 K for Si(100)-2 x 1 irradiated with 230 eV Ar ions at 110 K, but not for Si(100) following submonolayer Si deposition at 110 K. The data suggest that the smoothening at 160 K following 5 keV He ion irradiation at 110 K results from surface recombination of point defects which are generated on or below the surface by the irradiation and migrate to the surface at 110 K. (C) 1998 American Vacuum Society. [S0734-2101(98)06303-9]. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. RP Bedrossian, PJ (reprint author), Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. NR 11 TC 6 Z9 6 U1 0 U2 1 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0734-2101 J9 J VAC SCI TECHNOL A JI J. Vac. Sci. Technol. A-Vac. Surf. Films PD MAY-JUN PY 1998 VL 16 IS 3 BP 1043 EP 1046 DI 10.1116/1.581229 PN 1 PG 4 WC Materials Science, Coatings & Films; Physics, Applied SC Materials Science; Physics GA ZT991 UT WOS:000074150400028 ER PT J AU Mapes, M Hseuh, HC Cameron, P AF Mapes, M Hseuh, HC Cameron, P TI Design of a low cost, low magnetic susceptibility, ultrahigh vacuum compatible, flanged electrical break SO JOURNAL OF VACUUM SCIENCE & TECHNOLOGY A-VACUUM SURFACES AND FILMS LA English DT Article; Proceedings Paper CT 44th American-Vacuum-Society Symposium on Flat Panel Displays, Micromechanical Systems, and Quantitative Surface and Analysis CY OCT 20-24, 1997 CL SAN JOSE, CALIFORNIA SP Amer Vacuum Soc AB At Brookhaven National Laboratory, the g-2 experiment, a muon storage ring, requires a totally nonmagnetic vacuum system. All the vacuum components must have a low magnetic Susceptibility. The design of the beam vacuum system requires hanged electrical breaks on pumping manifolds in order to prevent ground loops. The electrical breaks developed at Brookhaven consist of a ceramic disk clamped between two Conflat flanges. A nonconductive retaining ring is used to support and center the ceramic disk and Seals with respect to the flanges. Two Helicoflex Delta seals are used to seal the flanges to the ceramic disk which has metallized surfaces in the seal area. Threaded rods which are electrically insulated from the flanges with bushings are used to provide the clamping force necessary to compress the vacuum seals. The assembly remains leak tight after repeated bakeouts up to 200 degrees C. This design offers several advantages over commercially available Conflat hanged ceramic breaks. These breaks do not use Kovar and are totally nonmagnetic. In addition to the cost being lower the overall length of the break is much shorter than commercial breaks. The same design concepts can be used for different sized Conflat flanges and for other types of flanges. The detailed design and the performance of this break are presented in this article. C1 Brookhaven Natl Lab, Upton, NY 11973 USA. RP Mapes, M (reprint author), Brookhaven Natl Lab, Upton, NY 11973 USA. NR 1 TC 0 Z9 0 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0734-2101 J9 J VAC SCI TECHNOL A JI J. Vac. Sci. Technol. A-Vac. Surf. Films PD MAY-JUN PY 1998 VL 16 IS 3 BP 1137 EP 1138 DI 10.1116/1.581247 PN 1 PG 2 WC Materials Science, Coatings & Films; Physics, Applied SC Materials Science; Physics GA ZT991 UT WOS:000074150400046 ER PT J AU Hseuh, HC Wallen, E AF Hseuh, HC Wallen, E TI Measurements of the helium propagation at 4.4 K in a 480 m long stainless steel pipe SO JOURNAL OF VACUUM SCIENCE & TECHNOLOGY A-VACUUM SURFACES AND FILMS LA English DT Article; Proceedings Paper CT 44th American-Vacuum-Society Symposium on Flat Panel Displays, Micromechanical Systems, and Quantitative Surface and Analysis CY OCT 20-24, 1997 CL SAN JOSE, CALIFORNIA SP Amer Vacuum Soc AB The relativistic heavy ion collider (RHIC), with two concentric rings 3.8 km in circumference, uses superconducting magnets to focus the high energy beams. Each sextant of RHIC will have continuous cryostats up to 480 m in length housing the magnets and the cold beam pipes. For an acceptable lifetime of the stored beam, the pressure in the cold beam pipe will be < 10(-11) Torr. The characteristics of He pressure front propagation due to He leaks will be of importance for beam lifetimes and for vacuum monitoring due to the high vapor pressure of He at 4.4 K, even with small surface coverage. The travels of the He pressure fronts along a 480 m long, 6.9 cm I.D. stainless steel beam pipe cooled to 4.4 K have recently been measured during the RHIC first sextant test. The experiment was carried out over a 12-day period by bleeding in a calibrated He leak of 3 X 10(-5) Torr 1/s (20 degrees C) while measuring the He pressures along this 480 m cold tube at approximately 30 m intervals. The measured speed of the pressure fronts and the pressure profiles are summarized and compared with the calculated ones. (C) 1998 American Vacuum Society. C1 Brookhaven Natl Lab, RHIC Project, Upton, NY 11973 USA. Univ Lund, Max Lab, S-22100 Lund, Sweden. RP Hseuh, HC (reprint author), Brookhaven Natl Lab, RHIC Project, Upton, NY 11973 USA. NR 9 TC 4 Z9 4 U1 1 U2 1 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0734-2101 J9 J VAC SCI TECHNOL A JI J. Vac. Sci. Technol. A-Vac. Surf. Films PD MAY-JUN PY 1998 VL 16 IS 3 BP 1145 EP 1150 DI 10.1116/1.581249 PN 1 PG 6 WC Materials Science, Coatings & Films; Physics, Applied SC Materials Science; Physics GA ZT991 UT WOS:000074150400048 ER PT J AU Moutinho, HR Al-Jassim, MM Levi, DH Dippo, PC Kazmerski, LL AF Moutinho, HR Al-Jassim, MM Levi, DH Dippo, PC Kazmerski, LL TI Effects of CdCl2 treatment on the recrystallization and electro-optical properties of CdTe thin films SO JOURNAL OF VACUUM SCIENCE & TECHNOLOGY A-VACUUM SURFACES AND FILMS LA English DT Article; Proceedings Paper CT 44th American-Vacuum-Society Symposium on Flat Panel Displays, Micromechanical Systems, and Quantitative Surface and Analysis CY OCT 20-24, 1997 CL SAN JOSE, CALIFORNIA SP Amer Vacuum Soc ID SOLAR-CELLS; VAPOR-DEPOSITION; PHOTOLUMINESCENCE; EFFICIENCY; GROWTH AB The effects of CdCl2 processing on the physical and electro-optical properties of CdTe were evaluated for thin films produced by physical vapor deposition and close-spaced sublimation (CSS). Two substrates (CdS and Indium-tin-oxide) were used with the physical vapor deposition (PVD) films specifically to isolate the effects of the Cd(SxTe1-x) alloy formed during the treatment of films deposited on CdS. The samples were analyzed by x-ray diffraction (XRD), atomic force microscopy (AFM), and photoluminescence. The observed changes in microstructure were caused by recrystallization, which consisted of the nucleation and development of a new CdTe structure and subsequent grain growth. Nevertheless, for these processes to take place, it was necessary that enough lattice-strain energy was available in the films; For this reason, PVD films did recrystallize, while CSS films did not. For the first time, recrystallization was observed directly in AFM images of CdTe films and confirmed by XRD analysis, which indicated the existence of two lattice parameters in PVD samples treated at 350 degrees C. For samples treated at 400 degrees C, the CdCl2 treatment improved the minority-carrier lifetime of the films by more than one order of magnitude. This improvement was attributed to the elimination of deep defect levels within the band gap of the CdTe films as a result of the treatment. The sulfur diffusion into CdTe films deposited on CdS, during the CdCl2 treatment at 400 degrees C, strongly affected the defect structure. C1 Natl Renewable Energy Lab, Golden, CO 80401 USA. RP Moutinho, HR (reprint author), Natl Renewable Energy Lab, Golden, CO 80401 USA. EM helio_moutinho@nrel.gov NR 20 TC 121 Z9 124 U1 3 U2 34 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0734-2101 J9 J VAC SCI TECHNOL A JI J. Vac. Sci. Technol. A-Vac. Surf. Films PD MAY-JUN PY 1998 VL 16 IS 3 BP 1251 EP 1257 DI 10.1116/1.581269 PN 1 PG 7 WC Materials Science, Coatings & Films; Physics, Applied SC Materials Science; Physics GA ZT991 UT WOS:000074150400068 ER PT J AU Mishra, SR Cummins, TR Waddill, GD Goodman, KW Tobin, JG Gammon, WJ Sherwood, T Pappas, DP AF Mishra, SR Cummins, TR Waddill, GD Goodman, KW Tobin, JG Gammon, WJ Sherwood, T Pappas, DP TI Characterization and photoemission dichroism of epitaxially grown Gd(0001)/Y(0001) SO JOURNAL OF VACUUM SCIENCE & TECHNOLOGY A-VACUUM SURFACES AND FILMS LA English DT Article; Proceedings Paper CT 44th American-Vacuum-Society Symposium on Flat Panel Displays, Micromechanical Systems, and Quantitative Surface and Analysis CY OCT 20-24, 1997 CL SAN JOSE, CALIFORNIA SP Amer Vacuum Soc ID CORE-LEVEL PHOTOEMISSION; MAGNETIC CIRCULAR-DICHROISM; LINEARLY POLARIZED-LIGHT; X-RAY DICHROISM; PHOTOELECTRON-SPECTROSCOPY; FINE-STRUCTURE; SURFACE; FILMS; DIFFRACTION; GD AB Gadolinium thin films approximately 100 Angstrom thick have been grown epitaxially on a Y(0001) substrate. A threefold characterization has been performed. The surface structural analyses of the yttrium substrate and the gadolinium films were performed using x-ray photoelectron diffraction (XPD) and low-energy electron diffraction (LEED). The results of the XPD and LEED studies strongly suggest that gadolinium films have an effective C-6v Surface symmetry, consistent with earlier studies of other hcp (0001) surfaces. The elemental analysis of the substrate and the film was done with x-ray photoemission using Mg, Al K alpha x rays and synchrotron radiation. The magnetic analysis is based upon magnetic x-ray dichroisms observed in angle-resolved photoelectron spectroscopy, using both Linearly polarized and circularly polarized synchrotron x-ray radiation as the excitation. Photoemission from the Gd 4f and 5p core-level states were used in this magnetic characterization and will be presented. This includes novel magnetic linear dichroism angular distribution results for the Gd 5p, which exhibit up to 40% asymmetry, on a par with the previously reported circular dichroism results. (C) 1998 American Vacuum Society. [S0734-2101(98)01603-0]. C1 Virginia Commonwealth Univ, Dept Phys, Richmond, VA 23284 USA. Univ Missouri, Dept Phys, Rolla, MO 65401 USA. Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 93550 USA. RP Mishra, SR (reprint author), Virginia Commonwealth Univ, Dept Phys, Richmond, VA 23284 USA. EM sanjay@b17-36.als.lbl.gov RI Tobin, James/O-6953-2015 NR 45 TC 8 Z9 8 U1 0 U2 2 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0734-2101 J9 J VAC SCI TECHNOL A JI J. Vac. Sci. Technol. A-Vac. Surf. Films PD MAY-JUN PY 1998 VL 16 IS 3 BP 1348 EP 1354 DI 10.1116/1.581149 PN 1 PG 7 WC Materials Science, Coatings & Films; Physics, Applied SC Materials Science; Physics GA ZT991 UT WOS:000074150400085 ER PT J AU Freeland, JW Chakarian, V Idzerda, YU Doherty, S Zhu, JG Wende, H Kao, CC AF Freeland, JW Chakarian, V Idzerda, YU Doherty, S Zhu, JG Wende, H Kao, CC TI Directly identifying the order of layer switching in magnetic multilayers SO JOURNAL OF VACUUM SCIENCE & TECHNOLOGY A-VACUUM SURFACES AND FILMS LA English DT Article; Proceedings Paper CT 44th American-Vacuum-Society Symposium on Flat Panel Displays, Micromechanical Systems, and Quantitative Surface and Analysis CY OCT 20-24, 1997 CL SAN JOSE, CALIFORNIA SP Amer Vacuum Soc ID RESONANCE EXCHANGE SCATTERING; CIRCULAR-DICHROISM; COBALT; EDGES; FILMS; IRON; CO AB The determination of the order of layer switching for two different technologically interesting multilayer systems, NiFe/Cu/Co and Co/Cr/Co, is accomplished by monitoring changes in the angular dependence of the magnetic contributions to the soft x-ray resonant magnetic scattering asa function of applied field. (C) 1998 American Vacuum Society. [S0734-2101(98)06603-2]. C1 USN, Res Lab, Washington, DC 20375 USA. Carnegie Mellon Univ, DSSC, Pittsburgh, PA 15213 USA. Free Univ Berlin, D-14195 Berlin, Germany. Brookhaven Natl Lab, NSLS, Upton, NY 11973 USA. RP Freeland, JW (reprint author), NRL, NSLS Bldg 725A-4UB, Upton, NY 11973 USA. EM freeland@bnlls3.nsls.bnl.gov RI Wende, Heiko/J-8505-2012 NR 21 TC 3 Z9 3 U1 0 U2 1 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0734-2101 J9 J VAC SCI TECHNOL A JI J. Vac. Sci. Technol. A-Vac. Surf. Films PD MAY-JUN PY 1998 VL 16 IS 3 BP 1355 EP 1358 DI 10.1116/1.581150 PN 1 PG 4 WC Materials Science, Coatings & Films; Physics, Applied SC Materials Science; Physics GA ZT991 UT WOS:000074150400086 ER PT J AU Jia, QX Arendt, PN Kwon, C Roper, JM Fan, Y Groves, JR Foltyn, SR AF Jia, QX Arendt, PN Kwon, C Roper, JM Fan, Y Groves, JR Foltyn, SR TI Biaxially oriented conductive La0.5Sr0.5CoO3 thin films on SiO2/Si SO JOURNAL OF VACUUM SCIENCE & TECHNOLOGY A-VACUUM SURFACES AND FILMS LA English DT Article; Proceedings Paper CT 44th American-Vacuum-Society Symposium on Flat Panel Displays, Micromechanical Systems, and Quantitative Surface and Analysis CY OCT 20-24, 1997 CL SAN JOSE, CALIFORNIA SP Amer Vacuum Soc ID CO-O HETEROSTRUCTURES; SILICON AB We have grown biaxially textured La0.5Sr0.5CoO3 (LSCO) thin films on technically important SiO2/Si substrates by pulsed laser deposition, where a biaxially oriented yttria-stabilized zirconia (YSZ) produced by ion-beam-assisted deposition (IBAD) is used as a seed layer to enhance the texture of LSCO on SiO2/Si. The degree of in-plane texturing of LSCO is directly related to the quality of IBAD-YSZ. The smaller the value of full width at half maximum of the IBAD-YSZ (220) diffraction peak, the higher the crystallinity of the LSCO film. The biaxially oriented LSCO film deposited at 700 degrees C on SiO2/Si shows metallic resistivity versus temperature characteristics and has a room-temperature resistivity of around 110 mu Ohm cm. (C) 1998 American Vacuum Society. C1 Univ Calif Los Alamos Natl Lab, Div Mat Sci & Technol, Los Alamos, NM 87545 USA. RP Jia, QX (reprint author), Univ Calif Los Alamos Natl Lab, Div Mat Sci & Technol, Los Alamos, NM 87545 USA. RI Jia, Q. X./C-5194-2008 NR 11 TC 7 Z9 7 U1 0 U2 2 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0734-2101 J9 J VAC SCI TECHNOL A JI J. Vac. Sci. Technol. A-Vac. Surf. Films PD MAY-JUN PY 1998 VL 16 IS 3 BP 1380 EP 1383 DI 10.1116/1.581155 PN 1 PG 4 WC Materials Science, Coatings & Films; Physics, Applied SC Materials Science; Physics GA ZT991 UT WOS:000074150400091 ER PT J AU Schenkel, T Hamza, AV Barnes, AV Schneider, DH Walsh, DS Doyle, BL AF Schenkel, T Hamza, AV Barnes, AV Schneider, DH Walsh, DS Doyle, BL TI Analysis of B-SiO2 films by highly charged ion based time-of-flight secondary ion mass spectrometry, standard secondary ion mass spectrometry and elastic recoil detection SO JOURNAL OF VACUUM SCIENCE & TECHNOLOGY A-VACUUM SURFACES AND FILMS LA English DT Article; Proceedings Paper CT 44th American-Vacuum-Society Symposium on Flat Panel Displays, Micromechanical Systems, and Quantitative Surface and Analysis CY OCT 20-24, 1997 CL SAN JOSE, CALIFORNIA SP Amer Vacuum Soc ID SEMICONDUCTORS; SENSITIVITY; BOMBARDMENT; JUNCTIONS; SURFACES; SILICON; OXYGEN; SI AB B-SiO2 films formed by chemical vapor deposition on silicon substrates were analyzed by time-of-flight secondary ion mass spectrometry using slow Xe44+ and Th70+ as primary ions. Boron concentrations of 2 X 10(21) Cm-3 determined directly from positive secondary ion spectra agree with results from elastic recoil detection measurements, indicating strong decoupling of positive secondary ion production probabilities from elemental ionization potentials in the intense electronic sputtering induced by highly charged ions. Results demonstrate advantages of highly charged ions for quantitative analysis of surface near layers of materials. (C) 1998 American Vacuum Society. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. Sandia Natl Lab, Dept Phys, Albuquerque, NM 87185 USA. RP Schenkel, T (reprint author), Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. NR 24 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 USA SN 0734-2101 J9 J VAC SCI TECHNOL A JI J. Vac. Sci. Technol. A-Vac. Surf. Films PD MAY-JUN PY 1998 VL 16 IS 3 BP 1384 EP 1387 DI 10.1116/1.581523 PN 1 PG 4 WC Materials Science, Coatings & Films; Physics, Applied SC Materials Science; Physics GA ZT991 UT WOS:000074150400092 ER PT J AU Chen, JL Mu, R Ueda, A Wu, MH Tung, YS Gu, Z Henderson, DO White, CW Budai, JD Zuhr, RA AF Chen, JL Mu, R Ueda, A Wu, MH Tung, YS Gu, Z Henderson, DO White, CW Budai, JD Zuhr, RA TI Characterization of zinc implanted silica: Effects of thermal annealing and picosecond laser radiation SO JOURNAL OF VACUUM SCIENCE & TECHNOLOGY A-VACUUM SURFACES AND FILMS LA English DT Article; Proceedings Paper CT 44th National Symposium of the American-Vacuum-Society CY OCT 20-24, 1997 CL SAN JOSE, CALIFORNIA SP Amer Vacuum Soc ID SEQUENTIAL ION-IMPLANTATION; POROUS-MEDIA; SURFACE; SPECTRA; MICROCRYSTALS; BOROSILICATE; ABSORPTION; PARTICLES; BEHAVIOR; LIQUIDS AB Zinc ion implanted silica with controlled thermal treatments and pulsed laser radiation has been investigated. Optical spectra of the as-implanted silica at higher doses (>3 X 10(16) ions/cm(2)) and/or the samples annealed in a reducing atmosphere show both Zn clusters and Zn metal colloid formation. The absorption peak at similar to 5.3 eV is attributed to the surface plasmon absorption of Zn metal colloids in silica. The oxidized samples with the ion dose greater than or equal to 3x10(16) ions/cm(2) show an absorption peak in 4.3-4.7 eV region implying ZnO quantum dot formation. It is expected that the average size of the ZnO nanoparticles becomes smaller for lower ion dose. Therefore, a blueshift of the absorption peak with lower ion dose can be attributed to the quantum confinement effects. Pulsed laser radiation at 266 nm with energy density of 30 mJ/cm(2) causes a brownish coloration in these optically transparent Zn implanted silica substrates. The color formation is an irreversible process. Therefore, it is believed that new chemical species may have formed through photochemical reactions. The results also show that the coloring process is photon energy dependent. (C) 1998 American Vacuum Society. C1 Fisk Univ, Dept Phys, Chem Phys Lab, Nashville, TN 37208 USA. Oak Ridge Natl Lab, Div Solid State, Oak Ridge, TN 37831 USA. RP Chen, JL (reprint author), Fisk Univ, Dept Phys, Chem Phys Lab, Nashville, TN 37208 USA. EM hendersn@dubois.fisk.edu RI Budai, John/R-9276-2016 OI Budai, John/0000-0002-7444-1306 NR 25 TC 29 Z9 29 U1 0 U2 6 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0734-2101 J9 J VAC SCI TECHNOL A JI J. Vac. Sci. Technol. A-Vac. Surf. Films PD MAY-JUN PY 1998 VL 16 IS 3 BP 1409 EP 1413 DI 10.1116/1.581159 PN 2 PG 5 WC Materials Science, Coatings & Films; Physics, Applied SC Materials Science; Physics GA ZT992 UT WOS:000074150500002 ER PT J AU Hong, J Lee, JW Abernathy, CR Lambers, ES Pearton, SJ Shul, RJ Hobson, WS AF Hong, J Lee, JW Abernathy, CR Lambers, ES Pearton, SJ Shul, RJ Hobson, WS TI Comparison of plasma chemistries for inductively coupled plasma etching of InGaAlP alloys SO JOURNAL OF VACUUM SCIENCE & TECHNOLOGY A-VACUUM SURFACES AND FILMS LA English DT Article; Proceedings Paper CT 44th National Symposium of the American-Vacuum-Society CY OCT 20-24, 1997 CL SAN JOSE, CALIFORNIA SP Amer Vacuum Soc ID HETEROJUNCTION BIPOLAR-TRANSISTORS; MOLECULAR-BEAM EPITAXY; HIGH-TEMPERATURE OPERATION; CONTINUOUS-WAVE OPERATION; VAPOR-PHASE EPITAXY; SINGLE-HETEROJUNCTION; GROWTH; INP; PERFORMANCE; LASERS AB Two plasma chemistries, i.e., CH4/H-2/Ar and Cl-2/Ar, were compared for the etching of InGaP, AlInP, and AlGaP under inductively coupled plasma (ICP) conditions. While the etching with CH4/H-2/Ar discharges appears to be ion driven, Cl-2/Ar discharges showed an additional strong chemical enhancement. The highest etch rate (similar to 1 mu m/min) for InGaP was achieved at high ICP source power (greater than or equal to 750 W) with the Cl-2/Ar chemistry. Cl-2/Ar discharges provided very smooth surfaces in all three materials with root-mean-square roughness measured by atomic force microscopy around 2 nm. This result may be due to the efficient ion-assisted product desorption in this chemistry. The etched near-surface region of InGaP (similar to 100 Angstrom) with Cl-2/Ar maintained almost the same stoichiometry as that of the unetched control. By contrast, the CH4/H-2/Ar plasma chemistry produced somewhat rougher surfaces and depletion of phosphorous (P) from the surface of InGaP. (C) 1998 American Vacuum Society. C1 Univ Florida, Dept Mat Sci & Engn, Gainesville, FL 32611 USA. Sandia Natl Labs, Albuquerque, NM 87185 USA. AT&T Bell Labs, Lucent Technol, Murray Hill, NJ 07974 USA. RP Hong, J (reprint author), Univ Florida, Dept Mat Sci & Engn, Gainesville, FL 32611 USA. NR 34 TC 5 Z9 5 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0734-2101 J9 J VAC SCI TECHNOL A JI J. Vac. Sci. Technol. A-Vac. Surf. Films PD MAY-JUN PY 1998 VL 16 IS 3 BP 1497 EP 1501 DI 10.1116/1.581176 PN 2 PG 5 WC Materials Science, Coatings & Films; Physics, Applied SC Materials Science; Physics GA ZT992 UT WOS:000074150500019 ER PT J AU Shul, RJ Willison, CG Bridges, MM Han, J Lee, JW Pearton, SJ Abernathy, CR MacKenzie, JD Donovan, SM Zhang, L Lester, LF AF Shul, RJ Willison, CG Bridges, MM Han, J Lee, JW Pearton, SJ Abernathy, CR MacKenzie, JD Donovan, SM Zhang, L Lester, LF TI Selective inductively coupled plasma etching of group-III nitrides in Cl-2- and BCl3-based plasmas SO JOURNAL OF VACUUM SCIENCE & TECHNOLOGY A-VACUUM SURFACES AND FILMS LA English DT Article; Proceedings Paper CT 44th National Symposium of the American-Vacuum-Society CY OCT 20-24, 1997 CL SAN JOSE, CALIFORNIA SP Amer Vacuum Soc ID LIGHT-EMITTING DIODES; V NITRIDES; GAN; BCL3; CHEMISTRIES; ALN; INN AB High-density plasma etching has been an effective patterning technique for the group-III nitrides due to ion fluxes which are two to four orders of magnitude higher than more conventional reactive ion etch systems. GaN etch rates exceeding 0.5 mu m/min have been reported in inductively coupled plasma (ICP) etch systems at relatively high dc-biases (> 200 V). However,; under these conditions, the etch mechanism is dominated by ion bombardment energies which can induce damage and minimize etch selectivity. Development of etch processes with high selectivity has become relevant with recent interest in high power, high temperature electronic devices. In this study, we report ICP etch rates and selectivities for GaN, AlN, and InN in Cl-2/Ar, Cl-2/N-2, Cl-2/H-2, Cl-2/SF6, BCl3/Ar, BCl3/H-2, BCl3/N-2, and BCl3/SF6 plasma chemistries. (C) 1998 American Vacuum Society. C1 Univ Florida, Dept Mat Sci & Engn, Gainesville, FL 32611 USA. Univ New Mexico, Dept Elect Engn, Albuquerque, NM 87131 USA. RP Shul, RJ (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. NR 19 TC 49 Z9 50 U1 1 U2 21 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0734-2101 J9 J VAC SCI TECHNOL A JI J. Vac. Sci. Technol. A-Vac. Surf. Films PD MAY-JUN PY 1998 VL 16 IS 3 BP 1621 EP 1626 DI 10.1116/1.581130 PN 2 PG 6 WC Materials Science, Coatings & Films; Physics, Applied SC Materials Science; Physics GA ZT992 UT WOS:000074150500041 ER PT J AU Cho, H Vartuli, CB Donovan, SM Abernathy, CR Pearton, SJ Shul, RJ Constantine, C AF Cho, H Vartuli, CB Donovan, SM Abernathy, CR Pearton, SJ Shul, RJ Constantine, C TI Comparison of inductively coupled plasma Cl-2 and Cl-4/H-2 etching of III-nitrides SO JOURNAL OF VACUUM SCIENCE & TECHNOLOGY A-VACUUM SURFACES AND FILMS LA English DT Article; Proceedings Paper CT 44th National Symposium of the American-Vacuum-Society CY OCT 20-24, 1997 CL SAN JOSE, CALIFORNIA SP Amer Vacuum Soc ID FIELD-EFFECT TRANSISTORS; MOLECULAR-BEAM EPITAXY; OHMIC CONTACTS; V NITRIDES; GAN; INP; GROWTH; ALN; CL2 AB A parametric study of etch rates, selectivity, surface morphology and etch anisotropy has been performed for Cl-2 and CH4/H-2 inductively coupled plasma (ICP) patterning of GaN, AlN, InN, InAlN, and InGaN at low de self-biases (typically less than or equal to -100 V). Controlled etch rates in the range 500-1500 Angstrom min(-1) are obtained for all materials. Surface morphology is a strong function of ion energy and plasma composition in both chemistries, while vertical sidewalls are obtained over a wide range of conditions because of the ion-driven nature of the etch mechanism. (C) 1998 American Vacuum Society. C1 Univ Florida, Dept Mat Sci & Engn, Gainesville, FL 32611 USA. Sandia Natl Labs, Albuquerque, NM 87185 USA. Plasma Therm Inc, St Petersburg, FL 33716 USA. RP Cho, H (reprint author), Univ Florida, Dept Mat Sci & Engn, Gainesville, FL 32611 USA. NR 30 TC 28 Z9 28 U1 3 U2 12 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0734-2101 J9 J VAC SCI TECHNOL A JI J. Vac. Sci. Technol. A-Vac. Surf. Films PD MAY-JUN PY 1998 VL 16 IS 3 BP 1631 EP 1635 DI 10.1116/1.581132 PN 2 PG 5 WC Materials Science, Coatings & Films; Physics, Applied SC Materials Science; Physics GA ZT992 UT WOS:000074150500043 ER PT J AU Smentkowski, VS Holecek, JC Schultz, JA Krauss, AR Gruen, DM AF Smentkowski, VS Holecek, JC Schultz, JA Krauss, AR Gruen, DM TI Use of reactive ion sputtering to produce clean germanium surfaces in a carbon rich environment - an ion scattering study SO JOURNAL OF VACUUM SCIENCE & TECHNOLOGY A-VACUUM SURFACES AND FILMS LA English DT Article; Proceedings Paper CT 44th National Symposium of the American-Vacuum-Society CY OCT 20-24, 1997 CL SAN JOSE, CALIFORNIA SP Amer Vacuum Soc ID ENERGY-LOSS SPECTROSCOPY; CORE-LEVEL SHIFTS; GE SURFACES; HYDROGEN ADSORPTION; GE(111) SURFACES; THIN-FILMS; GE(100); NO; NH3; H2O AB We have used the ion spectroscopic techniques of direct recoil spectroscopy and mass spectroscopy of recoiled ions to demonstrate that low energy reactive ion sputtering of Ge is capable of removing surface impurities such as carbon. The experiments were performed in a vacuum chamber maintained at 3.5X10(-7) Torr. At these pressures, physical sputtering using noble gas is not effective for cleaning Ge surfaces as carbon redeposits onto the surface. In this article, we demonstrate that reactive sputtering of Ge using 4.0 keV nitrogen at a Ge surface temperature of similar to 740 K and above removes surface carbon and deposits nitrogen on the Ge surface. Heating the nitrogen exposed Ge surface to above similar to 880 K results in the desorption of nitrogen and generates an atomically clean Ge surface, under poor vacuum conditions. (C) 1998 American Vacuum Society. C1 Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. Argonne Natl Lab, Div Chem, Argonne, IL 60439 USA. Ionwerks, Houston, TX 77005 USA. RP Smentkowski, VS (reprint author), GE, Ctr Corp Res & Dev, Characterizat & Environm Technol Lab, POB 8, Schenectady, NY 12301 USA. NR 38 TC 4 Z9 4 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0734-2101 J9 J VAC SCI TECHNOL A JI J. Vac. Sci. Technol. A-Vac. Surf. Films PD MAY-JUN PY 1998 VL 16 IS 3 BP 1779 EP 1784 DI 10.1116/1.581106 PN 2 PG 6 WC Materials Science, Coatings & Films; Physics, Applied SC Materials Science; Physics GA ZT992 UT WOS:000074150500071 ER PT J AU Choi, SJ Veerasingam, R AF Choi, SJ Veerasingam, R TI Simulations of BCl3/Cl-2 plasma in an inductively coupled gaseous reference cell SO JOURNAL OF VACUUM SCIENCE & TECHNOLOGY A-VACUUM SURFACES AND FILMS LA English DT Article; Proceedings Paper CT 44th National Symposium of the American-Vacuum-Society CY OCT 20-24, 1997 CL SAN JOSE, CALIFORNIA SP Amer Vacuum Soc ID INTEGRATED-CIRCUITS; ALUMINUM-ALLOYS; METAL ETCH AB A gas mixture of BCl3/Cl-2 is widely used in the microelectronics industry to etch the Al metal layers on semiconductor wafers. An understanding of the plasma chemistry is necessary and crucial to improve the uniformity and etch rate of the metal etch on the wafers. To study the plasma characteristics of metal etch reactors a two-dimensional numerical plasma reactor model is used to simulate the processing etching chemistry. The predictive capability of the model depends sensitively on the accuracy of the plasma chemistry mechanisms, the database, and the surface chemistry that are included in the model. First, the model is validated over a wide range of power, pressure, and gas compositions with the available experimental data. For low-pressure (few to tens of mTorr) etching reactors used in the semiconductor industry, the boundary conditions for the model are very important because of the relatively large gas mean-free paths. The gas phase chemistry is strongly influenced by the surface chemical processes. Unfortunately, the correct boundary conditions for the surface chemistry in the model are extremely difficult to set since the chamber wall condition is determined by the wall temperature, surface type (wall material and the covered chemical species), and the process history (wall coverage) of the reactor. The sensitivity of the surface condition is demonstrated with the aluminum etching chemistry in an inductively coupled plasma gaseous reference cell reactor geometry by performing numerical simulations with different wall, recombination coefficients. (C) 1998 American Vacuum Society. C1 Sandia Natl Labs, Engn Sci Ctr, Albuquerque, NM 87185 USA. Penn State Univ, University Pk, PA 16802 USA. RP Choi, SJ (reprint author), Sandia Natl Labs, Engn Sci Ctr, POB 5800, Albuquerque, NM 87185 USA. NR 28 TC 8 Z9 10 U1 0 U2 3 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0734-2101 J9 J VAC SCI TECHNOL A JI J. Vac. Sci. Technol. A-Vac. Surf. Films PD MAY-JUN PY 1998 VL 16 IS 3 BP 1873 EP 1879 DI 10.1116/1.581121 PN 2 PG 7 WC Materials Science, Coatings & Films; Physics, Applied SC Materials Science; Physics GA ZT992 UT WOS:000074150500088 ER PT J AU Seal, S Underwood, H Uda, M Osawa, H Kanai, A Barr, TL Benko, E Krauss, A Perera, RCC AF Seal, S Underwood, H Uda, M Osawa, H Kanai, A Barr, TL Benko, E Krauss, A Perera, RCC TI Effect of temperature on Ti and TiN films deposited on a BN substrate SO JOURNAL OF VACUUM SCIENCE & TECHNOLOGY A-VACUUM SURFACES AND FILMS LA English DT Article; Proceedings Paper CT 44th National Symposium of the American-Vacuum-Society CY OCT 20-24, 1997 CL SAN JOSE, CALIFORNIA SP Amer Vacuum Soc ID MECHANICAL-PROPERTIES; COATINGS; SPECTROSCOPY; MORPHOLOGY; INTERFACES; TI(B,N); STRESS AB Nitrides (such as BN and TiN) are widely used in various industrial applications because of their excellent wear and corrosion resistance and their thermal and electronic properties. The structural and chemical features formed during plasma vapor deposition of Ti/TiN on BN substrates have been studied using synchrotron radiation near edge absorption spectroscopy (NEXAFS). Various phases of interest have been formed with different annealing temperatures. Diffusion of the nitridation and the interference from oxidation (e.g., TiO2) and boride formation are of particular concern. X-ray photoelectron spectroscopy and secondary ion mass spectroscopy measurements complement our NEXAFS data. Phase formation and chemical bonding between the coating and the substrate are shown to be determining factors for the microhardness. (C) 1998 American Vacuum Society. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Ctr Xray Opt, Berkeley, CA 94720 USA. Waseda Univ, Tokyo, Japan. Univ Wisconsin, Dept Mat, Milwaukee, WI 53201 USA. Univ Wisconsin, Lab Surface Sci, Milwaukee, WI 53201 USA. Inst Cutting Tools, PL-30011 Cracow, Poland. Argonne Natl Lab, Argonne, IL 60439 USA. RP Seal, S (reprint author), Univ Cent Florida, Adv Mat Proc & Anal Ctr, Orlando, FL 32816 USA. NR 29 TC 5 Z9 5 U1 0 U2 4 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0734-2101 J9 J VAC SCI TECHNOL A JI J. Vac. Sci. Technol. A-Vac. Surf. Films PD MAY-JUN PY 1998 VL 16 IS 3 BP 1901 EP 1906 DI 10.1116/1.581125 PN 2 PG 6 WC Materials Science, Coatings & Films; Physics, Applied SC Materials Science; Physics GA ZT992 UT WOS:000074150500092 ER PT J AU Exarhos, GJ Rose, A Wang, LQ Windisch, CF AF Exarhos, GJ Rose, A Wang, LQ Windisch, CF TI Postdeposition reduction of noble metal doped ZnO films SO JOURNAL OF VACUUM SCIENCE & TECHNOLOGY A-VACUUM SURFACES AND FILMS LA English DT Article; Proceedings Paper CT 44th National Symposium of the American-Vacuum-Society CY OCT 20-24, 1997 CL SAN JOSE, CALIFORNIA SP Amer Vacuum Soc ID OXIDE THIN-FILMS; SAPPHIRE AB Insulating ZnO (wurtzite phase) films containing 1% to 2% Pt, Au, Pd, Ga, or Al dopants have been deposited onto silica, silicon, and aluminum substrates under oxidizing conditions. Substantial enhancement in film conductivity is promoted by postdeposition reduction in hydrogen above a critical temperature or by room temperature cathodic reduction in an electrochemical cell. Film reduction requires the presence of atomic hydrogen, formed at the film surface either by dissociative adsorption of gaseous Hz or its electrochemical generation from a buffered aqueous solution. As deposited and reduced films have been characterized using x-ray photoemission spectroscopy, Raman spectroscopy, optical transmission measurements, spectroscopic ellipsometry, voltammetry, chronopotentiometry, and four-point conductivity measurements. Results indicate that film deposition parameters and postdeposition reduction alter the oxidation states of both the zinc and the resident dopant cations. The zinc reduction reaction appears to be quasireversible while the reduced noble metal dopants in the films are not prone to reoxidation. These results may have implications for enhancing stability of the optical response and electrical conductivity exhibited by these films. (C) 1998 American Vacuum Society. C1 Pacific NW Lab, Richland, WA 99352 USA. RP Exarhos, GJ (reprint author), Pacific NW Lab, POB 999,MS K2-44, Richland, WA 99352 USA. EM gj_exarhos@pnl.gov NR 18 TC 20 Z9 20 U1 2 U2 5 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0734-2101 J9 J VAC SCI TECHNOL A JI J. Vac. Sci. Technol. A-Vac. Surf. Films PD MAY-JUN PY 1998 VL 16 IS 3 BP 1926 EP 1933 DI 10.1116/1.581198 PN 2 PG 8 WC Materials Science, Coatings & Films; Physics, Applied SC Materials Science; Physics GA ZT992 UT WOS:000074150500097 ER PT J AU Klem, JF Breiland, WG Fritz, IJ Drummond, TJ Lee, SR AF Klem, JF Breiland, WG Fritz, IJ Drummond, TJ Lee, SR TI Application of in situ reflectance monitoring to molecular beam epitaxy of vertical-cavity structures SO JOURNAL OF VACUUM SCIENCE & TECHNOLOGY B LA English DT Article; Proceedings Paper CT 16th North American Conference on Molecular Beam Epitaxy CY OCT 05-08, 1997 CL UNIV MICHIGAN, ANN ARBOR, MICHIGAN HO UNIV MICHIGAN ID GROWTH-RATE MEASUREMENTS; LASER REFLECTOMETRY; ELLIPSOMETRY; FILMS AB We have used normal-incidence reflectance to monitor the growth of molecular beam epitaxial films. Least-squares fitting of the single-wavelength reflectance over regions of constant film growth rate and composition allowed the determination of growth rate and the complex refractive index of the film at the growth temperature. For AlInGaAs materials employed in a 1.32 mu m reflectance modulator device, we found that layer thicknesses of approximately 500 Angstrom produced precise measurement of these parameters. A simple feedback control scheme based on these measurements was employed to control the wavelength of the room-temperature cavity mode resonance in these devices to approximately 0.2%. (C) 1998 American Vacuum Society. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Klem, JF (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. NR 14 TC 3 Z9 3 U1 1 U2 3 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 1071-1023 J9 J VAC SCI TECHNOL B JI J. Vac. Sci. Technol. B PD MAY-JUN PY 1998 VL 16 IS 3 BP 1498 EP 1501 DI 10.1116/1.589974 PG 4 WC Engineering, Electrical & Electronic; Nanoscience & Nanotechnology; Physics, Applied SC Engineering; Science & Technology - Other Topics; Physics GA ZV375 UT WOS:000074298300115 ER PT J AU Sinha, AK Bischof, CH AF Sinha, AK Bischof, CH TI Application of automatic differentiation to reservoir design models SO JOURNAL OF WATER RESOURCES PLANNING AND MANAGEMENT-ASCE LA English DT Article AB Automatic differentiation is a technique for computing derivatives accurately and efficiently with minimal human effort. The calculation of derivatives of numerical models is necessary for gradient-based optimization of reservoir systems to determine optimal sizes for reservoirs. The writers report on the use of automatic differentiation and divided difference approaches for computing derivatives for a single-and multiple-reservoir yield model. In the experiments, the ADIFOR (Automatic Differentiation of Fortran) tool is employed. The results show that, for both the single-and the multiple-reservoir model, automatic differentiation computes derivatives exactly and more efficiently than the divided difference implementation. Postoptimization of the ADIFOR-generated derivative code by exploiting the model structure is also discussed. The writers observe that the availability of exact derivatives significantly benefits the convergence of the optimization algorithm: the solution of the multireservoir problem, which took 10.5 hours with divided difference derivatives, is decreased to less than two hours with ADIFOR "out of the box" derivatives, and to less than an hour using the postoptimized ADIFOR derivative code. C1 Indian Inst Technol, Dept Civil Engn, Bombay 400076, Maharashtra, India. Argonne Natl Lab, Div Math & Comp Sci, Argonne, IL 60439 USA. RP Sinha, AK (reprint author), Indian Inst Technol, Dept Civil Engn, Bombay 400076, Maharashtra, India. RI Bischof, Christian/D-2897-2009 NR 23 TC 5 Z9 5 U1 0 U2 1 PU ASCE-AMER SOC CIVIL ENGINEERS PI RESTON PA 1801 ALEXANDER BELL DR, RESTON, VA 20191-4400 USA SN 0733-9496 J9 J WATER RES PL-ASCE JI J. Water Resour. Plan. Manage.-ASCE PD MAY-JUN PY 1998 VL 124 IS 3 BP 162 EP 167 DI 10.1061/(ASCE)0733-9496(1998)124:3(162) PG 6 WC Engineering, Civil; Water Resources SC Engineering; Water Resources GA ZJ414 UT WOS:000073213100005 ER PT J AU Kuhl, AL Ferguson, RE Reichenbach, H Neuwald, P Oppenheim, AK AF Kuhl, AL Ferguson, RE Reichenbach, H Neuwald, P Oppenheim, AK TI Dynamics of an explosion-driven planar exothermic jet SO JSME INTERNATIONAL JOURNAL SERIES B-FLUIDS AND THERMAL ENGINEERING LA English DT Article DE exothermic jet; unmixed turbulent combustion; stoichiometric subgrid model; after-burning in explosions; Adaptive Mesh Refinement (AMR); high order Godunov schemes; fluid-mechanically-controlled combustion AB Considered here is combustion of an explosion-driven turbulent jet in a thin cylindrical enclosure. The process is initiated in a small pre-chamber, filled with acetylene mixed with 10% air, and provided with an explosive igniter charge. The prechamber is connected to the main enclosure, filled with air at NTP, by a sealed orifice. Upon ignition of the explosive charge, the acetylene is thermally decomposed, generating a detonation in the pre-chamber. The high pressure thus engendered breaks the seal and creates a blast wave that injects the fuel jet into the main enclosure which undergoes then an exothermic process of combustion with air. The mixing layer is repeatedly compressed and expanded due to blast wave reverberations within the enclosure. Experimental results, in the form of cinematic shadow photographs and transient pressure records, are modeled by a two-dimensional CFD analysis of combustion dominated by turbulent mixing. The results reveal the dynamic features of turbulent combustion when the exothermicity is controlled by fluid-mechanic transport in a turbulent field, rather than by the effects of the exothermic reaction and diffusion, that is usually the case. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. Enig Associates, Silver Spring, MD 20904 USA. Ernst Mach Inst, Fraunhofer Inst Kurzzeitdynam, D-79104 Freiburg, Germany. Univ Calif Berkeley, Dept Mech Engn, Berkeley, CA 94720 USA. RP Kuhl, AL (reprint author), Univ Calif Lawrence Livermore Natl Lab, 7000 East Ave & POB 808 L-30, Livermore, CA 94550 USA. NR 30 TC 0 Z9 0 U1 1 U2 1 PU JAPAN SOC MECHANICAL ENGINEERS PI TOKYO PA SHINANOMACHI-RENGAKAN BLDG, SHINANOMACHI 35, SHINJUKU-KU, TOKYO, 160, JAPAN SN 1340-8054 J9 JSME INT J B-FLUID T JI JSME Int. J. Ser. B-Fluids Therm. Eng. PD MAY PY 1998 VL 41 IS 2 BP 416 EP 423 PG 8 WC Thermodynamics; Engineering, Mechanical SC Thermodynamics; Engineering GA ZX697 UT WOS:000074544900021 ER PT J AU Beatty, BR Foltz, C AF Beatty, BR Foltz, C TI Not unusual SO LAB ANIMAL LA English DT Editorial Material C1 Oak Ridge Natl Lab, Div Life Sci, Anim Resources Sect, Oak Ridge, TN 37831 USA. RP Beatty, BR (reprint author), Oak Ridge Natl Lab, Div Life Sci, Anim Resources Sect, Oak Ridge, TN 37831 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU NATURE AMERICA INC PI NEW YORK PA 345 PARK AVE SOUTH, NEW YORK, NY 10010-1707 USA SN 0093-7355 J9 LAB ANIMAL JI Lab Anim. PD MAY PY 1998 VL 27 IS 5 BP 22 EP 22 PG 1 WC Veterinary Sciences SC Veterinary Sciences GA ZM568 UT WOS:000073553200007 ER PT J AU Solarz, RW Emanuel, MA Skidmore, JA Freitas, BL Krupke, WF AF Solarz, RW Emanuel, MA Skidmore, JA Freitas, BL Krupke, WF TI Trends in packaging of high power semiconductor laser bars SO LASER PHYSICS LA English DT Article; Proceedings Paper CT 2nd International Conference on Modern Problems of Laser Physics CY JUL 28-AUG 02, 1997 CL NOVOSIBIRSK, RUSSIA AB Several different approaches to packaging high power diode laser bars for pumping solid state lasers or for direct diode laser applications are examined. The benefit and utility of each package is strongly dependent upon the fundamental optoelectronic properties of the individual diode laser bars. Factors which influence these properties are outlined and comparisons of packaging approaches for these materials are made. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Solarz, RW (reprint author), Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. NR 1 TC 5 Z9 5 U1 0 U2 0 PU INTERPERIODICA PI BIRMINGHAM PA PO BOX 1831, BIRMINGHAM, AL 35201-1831 USA SN 1054-660X J9 LASER PHYS JI Laser Phys. PD MAY-JUN PY 1998 VL 8 IS 3 BP 737 EP 740 PG 4 WC Optics; Physics, Applied SC Optics; Physics GA ZV831 UT WOS:000074345700031 ER PT J AU Marshall, CD Beach, RJ Bibeau, C Ebbers, CA Emanuel, MA Honea, EC Krupke, WF Payne, SA Powell, HT Schaffers, KI Skidmore, JA Sutton, SB AF Marshall, CD Beach, RJ Bibeau, C Ebbers, CA Emanuel, MA Honea, EC Krupke, WF Payne, SA Powell, HT Schaffers, KI Skidmore, JA Sutton, SB TI Next-generation laser for inertial confinement fusion SO LASER PHYSICS LA English DT Article; Proceedings Paper CT 2nd International Conference on Modern Problems of Laser Physics CY JUL 28-AUG 02, 1997 CL NOVOSIBIRSK, RUSSIA ID PERFORMANCE; AMPLIFIER AB We are in the process of developing and building the "Mercury" laser system as the first in a series of a new generation of diode-pumped solid-state Inertial Confinement Fusion (ICF) lasers at LLNL (see Fig. I below). Mercury will be the first integrated demonstration of a scalable laser architecture compatible with advanced high energy density (HED) physics applications. Primary performance goals include 10% efficiencies at 10 Hz and a 1-10 ns pulse with 1 omega energies of 100 J and with 2 omega/3 omega frequency conversion. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Marshall, CD (reprint author), Univ Calif Lawrence Livermore Natl Lab, POB 808, Livermore, CA 94550 USA. NR 10 TC 6 Z9 6 U1 0 U2 2 PU INTERPERIODICA PI BIRMINGHAM PA PO BOX 1831, BIRMINGHAM, AL 35201-1831 USA SN 1054-660X J9 LASER PHYS JI Laser Phys. PD MAY-JUN PY 1998 VL 8 IS 3 BP 741 EP 745 PG 5 WC Optics; Physics, Applied SC Optics; Physics GA ZV831 UT WOS:000074345700032 ER PT J AU Davis, AP Justice, MJ AF Davis, AP Justice, MJ TI Meeting report: 11th International Mouse Genome Conference SO MAMMALIAN GENOME LA English DT Editorial Material ID MICE C1 Oak Ridge Natl Lab, Div Life Sci, Oak Ridge, TN 37831 USA. RP Justice, MJ (reprint author), Oak Ridge Natl Lab, Div Life Sci, POB 2009, Oak Ridge, TN 37831 USA. FU NHGRI NIH HHS [HG00756] NR 13 TC 4 Z9 4 U1 0 U2 0 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 USA SN 0938-8990 J9 MAMM GENOME JI Mamm. Genome PD MAY PY 1998 VL 9 IS 5 BP 345 EP 348 DI 10.1007/s003359900767 PG 4 WC Biochemistry & Molecular Biology; Biotechnology & Applied Microbiology; Genetics & Heredity SC Biochemistry & Molecular Biology; Biotechnology & Applied Microbiology; Genetics & Heredity GA ZK441 UT WOS:000073321200001 PM 9545489 ER PT J AU Carver, EA Issel-Tarver, L Rine, J Olsen, AS Stubbs, L AF Carver, EA Issel-Tarver, L Rine, J Olsen, AS Stubbs, L TI Location of mouse and human genes corresponding to conserved canine olfactory receptor gene subfamilies SO MAMMALIAN GENOME LA English DT Article ID EXPRESSION; MAP; ORGANIZATION; SEQUENCE; PROTEIN; REGION; HUMAN-CHROMOSOME-19; CHROMOSOME-11; HOMOLOGY; CLONING AB Olfactory receptors are G protein-coupled, seven-transmembrane-domain proteins that are responsible for binding odorants in the nasal epithelium. They are encoded by a large gene family, members of which are organized in several clusters scattered throughout the genomes of mammalian species. Here we describe the mapping of mouse sequences corresponding to four conserved olfactory receptor genes, each representing separate, recently identified canine gene subfamilies. Three of the four canine genes detected related gene clusters in regions of mouse Chromosomes (Chrs) 2, 9, and 10, near previously mapped mouse olfactory genes, while one detected a formerly unidentified gene cluster located on mouse Chr 6. In addition, we have localized two human gene clusters with homology to the canine gene, CfOLF4, within the established physical map of Chr 19p. Combined with recently published studies, these data link the four conserved olfactory gene subfamilies to homologous regions of the human, dog, and mouse genomes. C1 Univ Calif Lawrence Livermore Natl Lab, Ctr Human Genome, Livermore, CA 94550 USA. Oak Ridge Natl Lab, Div Life Sci, Oak Ridge, TN 37831 USA. Univ Tennessee, Oak Ridge Grad Sch Biomed Sci, Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. Univ Calif Berkeley, Dept Mol & Cell Biol, Div Genet, Berkeley, CA 94720 USA. RP Stubbs, L (reprint author), Univ Calif Lawrence Livermore Natl Lab, Ctr Human Genome, POB 808, Livermore, CA 94550 USA. OI Stubbs, Lisa/0000-0002-9556-1972 NR 37 TC 17 Z9 17 U1 1 U2 3 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 USA SN 0938-8990 J9 MAMM GENOME JI Mamm. Genome PD MAY PY 1998 VL 9 IS 5 BP 349 EP 354 PG 6 WC Biochemistry & Molecular Biology; Biotechnology & Applied Microbiology; Genetics & Heredity SC Biochemistry & Molecular Biology; Biotechnology & Applied Microbiology; Genetics & Heredity GA ZK441 UT WOS:000073321200002 PM 9545490 ER PT J AU Tortorelli, PF DeVan, JH Judkins, RR Wright, IG AF Tortorelli, PF DeVan, JH Judkins, RR Wright, IG TI Solid-state phase stabilities of relevance to metal dusting in coal gasifier environments SO MATERIALS AND CORROSION-WERKSTOFFE UND KORROSION LA English DT Article ID ALLOY STEELS AB Thermochemical calculations involving some typical mixed-gas environments and temperatures of gasifiers were used to examine iron-based phase stabilities to assess the potential for metal dusting in coal gasification systems. The results indicated that Fe3C is only stable under conditions when certain reactions are suppressed and that FeO and Fe0.877S tend to form instead of the carbide. Assuming Fe3C is a necessary step in the metal dusting of steels, there are therefore numerous coal gasification systems where this type of carbon-related degradation will not occur, particularly under conditions associated with higher oxygen and sulfur activities. C1 Oak Ridge Natl Lab, Div Met & Ceram, Oak Ridge, TN 37831 USA. RP Tortorelli, PF (reprint author), Oak Ridge Natl Lab, Div Met & Ceram, POB 2008, Oak Ridge, TN 37831 USA. NR 18 TC 3 Z9 3 U1 0 U2 0 PU WILEY-V C H VERLAG GMBH PI BERLIN PA MUHLENSTRASSE 33-34, D-13187 BERLIN, GERMANY SN 0947-5117 J9 MATER CORROS JI Mater. Corros. PD MAY PY 1998 VL 49 IS 5 BP 340 EP 344 DI 10.1002/(SICI)1521-4176(199805)49:5<340::AID-MACO340>3.0.CO;2-L PG 5 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA ZP163 UT WOS:000073723400008 ER PT J AU Pawel, SJ Lopez, RJ Ondak, E AF Pawel, SJ Lopez, RJ Ondak, E TI Chemical and environmental influences on copper/copper sulfate reference electrode half cell potential SO MATERIALS PERFORMANCE LA English DT Article AB Standard copper/copper sulfate (Cu/CuSO4,) reference electrodes were manipulated to simulate a variety of chemical and environmental factors to evaluate possible sources of error in field potential measurements. C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. Off Pipeline Safety, Houston, TX 77004 USA. Golden Hills Ctr, Off Pipeline Safety, Lakewood, CO 80215 USA. RP Pawel, SJ (reprint author), Oak Ridge Natl Lab, POB 2008, Oak Ridge, TN 37831 USA. NR 1 TC 3 Z9 4 U1 1 U2 3 PU NATL ASSN CORROSION ENG PI HOUSTON PA 1440 SOUTH CREEK DRIVE, HOUSTON, TX 77084-4906 USA SN 0094-1492 J9 MATER PERFORMANCE JI Mater. Perform. PD MAY PY 1998 VL 37 IS 5 BP 24 EP 29 PG 6 WC Materials Science, Characterization & Testing SC Materials Science GA ZM523 UT WOS:000073548700008 ER PT J AU Zhu, YM AF Zhu, YM TI Why the large-angle twist-boundaries in Bi2Sr2CaCu2O8+delta can carry super-current? SO MATERIALS RESEARCH INNOVATIONS LA English DT Article DE Bi-superconductor; Bi-crystals; grain boundaries; structure-properties relationship; high resolution transmission electron microscopy (HRTEM); TEM image simulation; interfacial anisotropic strain-field; hole/charge distribution ID YBA2CU3O7-DELTA GRAIN-BOUNDARIES; BICRYSTALS AB Our recent investigation on superconducting properties of Bi2Sr2CaCu2O8+delta bicrystals showed that the [001] twist grain-boundaries, regardless of their misorientation angle, can carry the same critical current as their constituent single crystals. To find the origin of the absence of the weak-link behavior of the boundaries, we studied the structure of these electromagnetically characterized bicrystals using advanced transmission electron microscopy. The robust superconductivity at these boundaries was found mainly due to the high anisotropy of the crystals and the softness of the double BiO layers at the boundaries, which result the presence of the undisturbed CuO2 layers adjacent to the boundary plane. The structural characteristics of these boundaries are identical to those found in Bi-based tapes, suggesting that the large-angle twist boundaries are not a current-carrying barrier in this important material. C1 Brookhaven Natl Lab, Dept Appl Sci, Upton, NY 11973 USA. RP Zhu, YM (reprint author), Brookhaven Natl Lab, Dept Appl Sci, Upton, NY 11973 USA. EM zhu@bnl.gov NR 17 TC 1 Z9 1 U1 1 U2 2 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 USA SN 1432-8917 J9 MATER RES INNOV JI Mater. Res. Innov. PD MAY PY 1998 VL 2 IS 1 BP 9 EP 15 DI 10.1007/s100190050054 PG 7 WC Materials Science, Multidisciplinary SC Materials Science GA ZU221 UT WOS:000074174400002 ER PT J AU Shchukin, ED Vidensky, IV Michalske, TA Savenko, VI AF Shchukin, ED Vidensky, IV Michalske, TA Savenko, VI TI Microscratching in an electrochemical cell. Effect of gallium on the surface deformation in aluminum SO MATERIALS SCIENCE LA English DT Article ID MECHANICAL-PROPERTIES; FILMS AB The method of microscratching is combined with the electrochemical reduction of an active component on the tested surface to study the initial surface damage to metals and effects caused by active media. This allows us to model the influence of the active liquid metal in the absence of the liquid-metal phase at room temperature. We observed the phenomenon of surface plasticizing of aluminum caused by the reduction of gallium ions and discussed it in terms of the microscopic (dislocation) and macroscopic (finite-elements) approaches. C1 Eyp Johns Hopkins Univ, Baltimore, MD USA. Sandia Natl Labs, Albuquerque, NM 87185 USA. Russian Acad Sci, Inst Phys Chem, Moscow, Russia. NR 32 TC 0 Z9 0 U1 0 U2 1 PU PLENUM PUBL CORP PI NEW YORK PA CONSULTANTS BUREAU, 233 SPRING ST, NEW YORK, NY 10013 USA SN 1068-820X J9 MATER SCI+ JI Mater. Sci. PD MAY-JUN PY 1998 VL 34 IS 3 BP 344 EP 350 DI 10.1007/BF02355624 PG 7 WC Materials Science, Multidisciplinary SC Materials Science GA 191WH UT WOS:000080044200006 ER PT J AU Pint, BA Wright, IG Lee, WY Zhang, Y Prussner, K Alexander, KB AF Pint, BA Wright, IG Lee, WY Zhang, Y Prussner, K Alexander, KB TI Substrate and bond coat compositions: factors affecting alumina scale adhesion SO MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING LA English DT Article; Proceedings Paper CT 1997 Thermal Barrier Coatings Workshop CY MAY 19-21, 1997 CL CINCINNATI, OHIO SP USAF, Off Sci Res, USAF, Mat Directorate, US DOE, DARPA, Natl Aeronaut & Space Adm, Natl Inst Stand & Technol, USN, Off Naval Res DE alumina; oxide scales; scale adhesion; thermal barrier coatings ID PREDICTION MODEL DEVELOPMENT; CYCLIC OXIDATION BEHAVIOR; OXIDE SCALE; REACTIVE ELEMENTS; ALLOYS; SEGREGATION; RESISTANCE; SULFUR; LIFE; ADHERENCE AB Thermally grown oxide scales that form beneath ZrO2, top coats play an important role in determining the performance of thermal barrier coatings. Numerous factors, including the composition of both the alloy substrate and the bond coat, affect adhesion of the alpha-Al2O3 scale. Three areas of focus in the formation of an 'ideal', adherent scale encompass: (1) migration of Al and other elements in the metal substrate, (2) segregation of elements to the metal-scale interface and the scale grain boundaries, and (3) generation of stresses in the scale. Examples of the effects of reactive elements, Pt, indigenous S, and reaction temperature on scale adhesion are discussed. (C) 1998 Elsevier Science S.A. All rights reserved. C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Pint, BA (reprint author), Oak Ridge Natl Lab, POB 2008, Oak Ridge, TN 37831 USA. RI Pruessner, Karin/A-4949-2009; Pint, Bruce/A-8435-2008 OI Pint, Bruce/0000-0002-9165-3335 NR 58 TC 268 Z9 269 U1 5 U2 53 PU ELSEVIER SCIENCE SA 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 MAY 1 PY 1998 VL 245 IS 2 BP 201 EP 211 DI 10.1016/S0921-5093(97)00851-4 PG 11 WC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Science & Technology - Other Topics; Materials Science; Metallurgy & Metallurgical Engineering GA ZP160 UT WOS:000073723000008 ER PT J AU Miller, DJ Todt, VR St Louis-Weber, M Zhang, XF Steel, DG Field, MB Gray, KE AF Miller, DJ Todt, VR St Louis-Weber, M Zhang, XF Steel, DG Field, MB Gray, KE TI Microstructure and transport behavior of grain boundaries in YBa2Cu3Oy: a comparison between thin films and bulk bicrystals SO MATERIALS SCIENCE AND ENGINEERING B-SOLID STATE MATERIALS FOR ADVANCED TECHNOLOGY LA English DT Article; Proceedings Paper CT International Workshop on the Processing and Applications of Superconducting (RE)BCO Large Grain Materials CY JUL 07-09, 1997 CL CAMBRIDGE, ENGLAND DE thin films; bulk bicrystals; grain boundaries AB The microstructure and transport properties of grain boundaries in thin film and bulk bicrystals of YBa2Cu3O7-delta have been studied in detail. In this paper, we will concentrate on the unique features of grain boundaries in dual-seeded bulk bicrystals, particularly in comparison with grain boundaries in thin film bicrystals. The structures of these two types of grain boundaries can be very different: thin film boundaries typically exhibit meandering and impurity phases that extend through the thickness of the film while the bulk boundaries exhibit long, straight facets that can be relatively free of impurity phases. While the meandering configurations of grain boundaries in thin films has led to inconsistencies in transport results, the planar grain boundaries found in bulk samples provide an excellent opportunity to study the grain boundary transport behavior in a simpler geometry. Furthermore, the fabrication of these bulk bicrystals is flexible and reproducible so that boundaries of virtually any misorientation may be prepared. As an example of this versatility, we have systematically measured the transport critical current density as a function of misorientation angle in bulk bicrystals and compare these results with those measured in thin film bicrystals. (C) 1998 Published by Elsevier Science S.A. All rights reserved. C1 Argonne Natl Lab, Div Sci Mat, Argonne, IL 60439 USA. Argonne Natl Lab, Sci & Technol Ctr Superconduct, Argonne, IL 60439 USA. RP Miller, DJ (reprint author), Argonne Natl Lab, Div Sci Mat, 9700 S Cass Ave, Argonne, IL 60439 USA. NR 20 TC 19 Z9 19 U1 0 U2 2 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0921-5107 J9 MAT SCI ENG B-SOLID JI Mater. Sci. Eng. B-Solid State Mater. Adv. Technol. PD MAY 1 PY 1998 VL 53 IS 1-2 BP 125 EP 131 DI 10.1016/S0921-5107(97)00314-0 PG 7 WC Materials Science, Multidisciplinary; Physics, Condensed Matter SC Materials Science; Physics GA ZX654 UT WOS:000074540500024 ER PT J AU Kurmaev, EZ Stadler, S Ederer, DL Yarmoshenko, YM Zatsepin, DA Neumann, M Callcott, TA Grush, MM Perera, RCC Danilov, SE Arbuzov, VL AF Kurmaev, EZ Stadler, S Ederer, DL Yarmoshenko, YM Zatsepin, DA Neumann, M Callcott, TA Grush, MM Perera, RCC Danilov, SE Arbuzov, VL TI Sulphur precipitation in annealed sulphur-doped nickel studied by fluorescent X-ray emission SO MATERIALS TRANSACTIONS JIM LA English DT Article DE alloys; annealing; sulphur precipitation; X-ray fluorescence ID SULFUR; SEGREGATION; SURFACE AB The results of measurements of S L-2,L-3 ultra-soft X-ray emission spectra excited by synchrotron radiation at h upsilon=163-165 eV for samples with 240 ppm S in Ni after annealing at 400-700 degrees C are presented. It is found that S L2,3 X- ray emission spectra of S-impurity atoms in Ni show fine structure which can be simulated by a superposition of spectra of nickel sulphide and pure sulphur providing evidence that sulphur atoms are present after annealing both in solid solution and in clusters where they form S-S bonds. The variation of temperature and time of annealing (at T= 400 degrees C for 1 h and at T=700 degrees C for 2 h) leads to some redistribution of intensity of S L-2.3 X-ray emission valence spectra which can be attributed to changes in the number of S-Ni and S-S bonds in accordance with the limit of sulphur solubility at these temperatures. C1 Russian Acad Sci, Ural Div, Inst Phys Met, Yekaterinburg 620219, Russia. Tulane Univ, Dept Phys, New Orleans, LA 70118 USA. Univ Osnabruck, Fachbereich Phys, D-49069 Osnabruck, Germany. Univ Tennessee, Dept Phys, Knoxville, TN 37996 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Kurmaev, EZ (reprint author), Russian Acad Sci, Ural Div, Inst Phys Met, GSP-170, Yekaterinburg 620219, Russia. RI Yarmoshenko, Yuri/E-9531-2011; Kurmaev, Ernst/J-4254-2013; Danilov, Sergey/J-5554-2013; Arbuzov, Vadim/J-6034-2013; Zatsepin, Dmitry/F-5520-2012 OI Yarmoshenko, Yuri/0000-0001-8971-2052; Kurmaev, Ernst/0000-0003-4625-4930; Danilov, Sergey/0000-0001-9815-8196; Arbuzov, Vadim/0000-0003-0334-7459; NR 21 TC 5 Z9 5 U1 0 U2 4 PU JAPAN INST METALS PI SENDAI PA AOBA ARAMAKI, SENDAI, 980, JAPAN SN 0916-1821 J9 MATER T JIM JI Mater. Trans. JIM PD MAY PY 1998 VL 39 IS 5 BP 570 EP 573 PG 4 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA 102FL UT WOS:000074913700004 ER PT J AU Hanebutte, U Doss, E Ewing, T Tentner, A AF Hanebutte, U Doss, E Ewing, T Tentner, A TI Simulation of vehicle traffic on an Automated Highway System SO MATHEMATICAL AND COMPUTER MODELLING LA English DT Article DE traffic simulator; Automated Highway System; Autonomous Intelligent Cruise Control; vehicle platooning; parallel computing ID DRIVER AB A traffic simulator has been developed at Argonne National Laboratory to study highway traffic under various degrees of automation. The key components of this simulator include a global and a local Expert Driver Model, a human factor study, and a graphical user interface. Furthermore, an Autonomous Intelligent Cruise Control, which is based on a neural network controller, is described and results for two typical driving scenarios are given. Published by Elsevier Science Ltd. C1 Argonne Natl Lab, ITS Program, Argonne, IL 60439 USA. RP Hanebutte, U (reprint author), Argonne Natl Lab, ITS Program, 9700 S Cass Ave, Argonne, IL 60439 USA. RI Ewing, Thomas/G-5396-2014 NR 18 TC 1 Z9 1 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0895-7177 J9 MATH COMPUT MODEL JI Math. Comput. Model. PD MAY-JUN PY 1998 VL 27 IS 9-11 BP 129 EP 141 DI 10.1016/S0895-7177(98)00055-7 PG 13 WC Computer Science, Interdisciplinary Applications; Computer Science, Software Engineering; Mathematics, Applied SC Computer Science; Mathematics GA ZT068 UT WOS:000074045000009 ER PT J AU Karma, A Rappel, WJ Fuh, BC Trivedi, R AF Karma, A Rappel, WJ Fuh, BC Trivedi, R TI Model of banding in diffusive and convective regimes during directional solidification of peritectic systems SO METALLURGICAL AND MATERIALS TRANSACTIONS A-PHYSICAL METALLURGY AND MATERIALS SCIENCE LA English DT Article ID INTERFACE; ALLOYS AB The formation of banded microstructure in peritectic systems is examined theoretically in both diffusive and convective regimes. A rigorous model is developed in the diffusive regime that describes the non-steady-state growth of alternate solid alpha and beta phase bands with a planar solid-liquid interface. The model is extended to incorporate the effect of convection by assuming that solute diffusion takes place within a boundary layer of constant thickness, with a uniform composition in the mixed liquid zone outside this layer. The model predicts that convection effects in a semi-infinite sample narrow the composition range over which extended banding can occur, and the spacing of bands is reduced compared to the diffusive growth model. In a finite length sample, convection is shown to lead only to the transient formation of bands. In this transient banding regime, only a few bands with a Variable width are formed, and this transient banding process can occur over a wide range of compositions inside the two-phase peritectic region. Directional solidification studies in the Pb-Bi system show transient bands and agree qualitatively with these predictions. However, the basic mechanism of band formation observed in this system is found to be significantly different from the one assumed in the model. A new mechanism of banding is proposed in which continuous growth of both phases is present instead of nucleation at the boundary of the pre-existing phase. This mechanism yields an oscillatory structure with a shorter spatial periodicity than the band spacing predicted by the purely diffusive or boundary layer convective models. C1 Northeastern Univ, Dept Phys, Boston, MA 02115 USA. Northeastern Univ, Ctr Interdisciplinary Res Complex Syst, Boston, MA 02115 USA. Iowa State Univ, Dept Mat Sci & Engn, Ames, IA 50011 USA. Iowa State Univ, US DOE, Ames Lab, Ames, IA 50011 USA. RP Karma, A (reprint author), Northeastern Univ, Dept Phys, Boston, MA 02115 USA. NR 20 TC 69 Z9 75 U1 0 U2 12 PU MINERALS METALS MATERIALS SOC PI WARRENDALE PA 420 COMMONWEALTH DR, WARRENDALE, PA 15086 USA SN 1073-5623 J9 METALL MATER TRANS A JI Metall. Mater. Trans. A-Phys. Metall. Mater. Sci. PD MAY PY 1998 VL 29 IS 5 BP 1457 EP 1470 DI 10.1007/s11661-998-0361-1 PG 14 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA ZR054 UT WOS:000073931000011 ER PT J AU O'Hare, D Evans, JSO Francis, RJ Halasyamani, PS Norby, P Hanson, J AF O'Hare, D Evans, JSO Francis, RJ Halasyamani, PS Norby, P Hanson, J TI Time-resolved, in situ X-ray diffraction studies of the hydrothermal syntheses of microporous materials SO MICROPOROUS AND MESOPOROUS MATERIALS LA English DT Article; Proceedings Paper CT International Symposium on Zeolites and Microporous Crystals (ZMPC 97) CY AUG 24-27, 1997 CL WASEDA UNIV, TOKYO, JAPAN SP Waseda Univ, Kanto Dist Council Catalysis Soc Japan HO WASEDA UNIV DE hydrothermal chemistry; time-resolved X-ray diffraction; synchrotron radiation; microporous materials ID ANGLE NEUTRON-SCATTERING; POWDER DIFFRACTION; IN-SITU; RIETVELD REFINEMENT; CRYSTAL-STRUCTURE; CRYSTALLIZATION; ZEOLITES; CATALYST; SILICALITE; APPARATUS AB In this paper we describe the use of energy dispersive diffraction using 'white' synchrotron radiation and angular dispersive X-ray diffraction with a moving image plate detector to record time-resolved in situ diffraction data on a number of hydrothermal syntheses. We have studied the synthesis of an aluminophosphate, the open framework sulfide TMA-SnS-1, and the gallium fluorophosphate ULM-S, under hydrothermal conditions. The effect of varying the temperature of reaction, reactant source and pH of solution on the syntheses has been investigated. Evidence has been obtained that in cases where crystalline TMA-SnS-1 is formed, the reaction proceeds via an intermediate disordered lamellar phase, before reacting further to form the final product. In the synthesis of ULM-5 at least two intermediates have been observed. (C) 1998 Elsevier Science B.V. All rights reserved. C1 Univ Oxford, Inorgan Chem Lab, Oxford OX1 3QR, England. SUNY Stony Brook, Dept Chem, Stony Brook, NY 11794 USA. Brookhaven Natl Lab, Dept Chem, Upton, NY 11973 USA. RP O'Hare, D (reprint author), Univ Oxford, Inorgan Chem Lab, S Parks Rd, Oxford OX1 3QR, England. EM dermot.ohare@icl.ox.ac.uk RI Hanson, jonathan/E-3517-2010; Evans, John/E-6345-2012; Halasyamani, P. Shiv/A-8620-2009; Halasyamani, Shiv/J-3438-2014; Norby, Poul/B-9047-2014 OI Evans, John/0000-0001-6305-6341; Halasyamani, Shiv/0000-0003-1787-1040; Norby, Poul/0000-0002-2590-7050 NR 32 TC 31 Z9 31 U1 2 U2 14 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 1387-1811 J9 MICROPOR MESOPOR MAT JI Microporous Mesoporous Mat. PD MAY PY 1998 VL 21 IS 4-6 BP 253 EP 262 DI 10.1016/S1387-1811(98)00009-2 PG 10 WC Chemistry, Applied; Chemistry, Physical; Nanoscience & Nanotechnology; Materials Science, Multidisciplinary SC Chemistry; Science & Technology - Other Topics; Materials Science GA 116MW UT WOS:000075730000009 ER PT J AU Gabrisch, H Dahmen, U Johnson, E AF Gabrisch, H Dahmen, U Johnson, E TI In situ observations of the interaction of liquid lead inclusions with grain boundaries in aluminum SO MICROSCOPY AND MICROANALYSIS LA English DT Article DE liquid inclusions; grain boundaries; Al-Pb; in situ heating; wetting; triple junctions; coarsening ID VECTOR THERMODYNAMICS; ANISOTROPIC SURFACES; PB; AL AB The evolution of liquid lead (Pb) inclusions at grain boundaries in aluminum (Al) was investigated by direct in situ TEM observation in the temperature range from 330 degrees-643 degrees C. In agreement with earlier reports on quenched alloys, the characteristic contact angle of the lens-shaped grain boundary inclusions was found to be near 120 degrees. This angle remained approximately constant over the entire temperature range, ruling out the possibility of a wetting transition. Coarsening of grain boundary inclusions tvas observed to proceed mainly by Ostwald ripening, although coalescence could also be observed. Inclusions at grain boundaries, at triple junctions, and at the intersection of grain boundaries with the foil surfaces adopted characteristic shapes that were shown to be equilibrium forms. At the highest temperatures, the grain boundaries were observed to detach from the inclusions and the interaction of a migrating grain boundary with inclusions could be observed. C1 Univ Copenhagen, Niels Bohr Inst, Oersted Lab, DK-2100 Copenhagen O, Denmark. Univ Calif Berkeley, Lawrence Berkeley Lab, Natl Ctr Electron Microscopy, Div Sci Mat, Berkeley, CA 94720 USA. RP Johnson, E (reprint author), Univ Copenhagen, Niels Bohr Inst, Oersted Lab, Univ Pk 2, DK-2100 Copenhagen O, Denmark. RI Gabrisch, Heike/I-5021-2013 NR 16 TC 20 Z9 20 U1 0 U2 2 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 USA SN 1431-9276 J9 MICROSC MICROANAL JI Microsc. microanal. PD MAY-JUN PY 1998 VL 4 IS 3 BP 286 EP 293 PG 8 WC Materials Science, Multidisciplinary; Microscopy SC Materials Science; Microscopy GA 125AP UT WOS:000076215500012 ER PT J AU Liu, N Lamerdin, JE Tebbs, RS Schild, D Tucker, JD Shen, MR Brookman, KW Siciliano, MJ Walter, CA Fan, WF Narayana, LS Zhou, ZQ Adamson, AW Sorensen, KJ Chen, DJ Jones, NJ Thompson, LH AF Liu, N Lamerdin, JE Tebbs, RS Schild, D Tucker, JD Shen, MR Brookman, KW Siciliano, MJ Walter, CA Fan, WF Narayana, LS Zhou, ZQ Adamson, AW Sorensen, KJ Chen, DJ Jones, NJ Thompson, LH TI XRCC2 and XRCC3, new human Rad51-family members, promote chromosome stability and protect against DNA cross-links and other damages SO MOLECULAR CELL LA English DT Article ID RAY-SENSITIVE MUTANTS; STRAND BREAK REPAIR; HUMAN RAD51 PROTEIN; ATAXIA-TELANGIECTASIA CELLS; HAMSTER OVARY CELL; MAMMALIAN-CELLS; SACCHAROMYCES-CEREVISIAE; IONIZING-RADIATION; NUCLEAR FOCI; GENE AB The phenotypically similar hamster mutants irs1 and irs1SF exhibit high spontaneous chromosome instability and broad-spectrum mutagen sensitivity, including extreme sensitivity to DNA cross-linking agents. The human XRCC2 and XRCC3 genes, which functionally complement irs1 and irs1SF, respectively, were previously mapped in somatic cell hybrids. Characterization of these genes and sequence alignments reveal that XRCC2 and XRCC3 are members of an emerging family of Rad51-related proteins that likely participate in homologous recombination to maintain chromosome stability and repair DNA damage. XRCC3 is shown to interact directly with HsRad51, and like Rad55 and Rad57 in yeast, may cooperate with HsRad51 during recombinational repair. Analysis of the XRCC2 mutation in irs1 implies that XRCC2's function is not essential for viability in cultured hamster cells. C1 Lawrence Livermore Natl Lab, Biol & Biotechnol Res Program, Livermore, CA 94551 USA. Univ Calif San Francisco, Lab Radiobiol & Environm Hlth, San Francisco, CA 94143 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Life Sci, Berkeley, CA 94720 USA. Univ Texas, Ctr Canc, Dept Mol Genet, Houston, TX 77030 USA. Univ Texas, Hlth Sci Ctr, Dept Cellular & Struct Biol, San Antonio, TX 78284 USA. Los Alamos Natl Lab, Div Life Sci, Los Alamos, NM 87545 USA. RP Thompson, LH (reprint author), Lawrence Livermore Natl Lab, Biol & Biotechnol Res Program, Livermore, CA 94551 USA. RI Jones, Nigel/D-1997-2010 FU NCI NIH HHS [CA74046, CA34936]; NIGMS NIH HHS [GM32833] NR 61 TC 414 Z9 425 U1 1 U2 8 PU CELL PRESS PI CAMBRIDGE PA 600 TECHNOLOGY SQUARE, 5TH FLOOR, CAMBRIDGE, MA 02139 USA SN 1097-2765 J9 MOL CELL JI Mol. Cell PD MAY PY 1998 VL 1 IS 6 BP 783 EP 793 DI 10.1016/S1097-2765(00)80078-7 PG 11 WC Biochemistry & Molecular Biology; Cell Biology SC Biochemistry & Molecular Biology; Cell Biology GA ZQ508 UT WOS:000073869100002 PM 9660962 ER PT J AU Eguiluz, AG Schone, WD AF Eguiluz, AG Schone, WD TI Electronic excitations and correlation effects in metals SO MOLECULAR PHYSICS LA English DT Article; Proceedings Paper CT Coupled Cluster Theory Electron Correlation Workshop on 50 Years of the Correlation Problem CY JUN 15-19, 1997 CL CEDAR KEY, FL ID 2-DIMENSIONAL HUBBARD-MODEL; QUASI-PARTICLE DISPERSION; AB-INITIO CALCULATIONS; LOCAL-FIELD FACTOR; BAND-STRUCTURE; DYNAMIC-RESPONSE; CONSERVING APPROXIMATIONS; QUASIPARTICLE ENERGIES; DIELECTRIC FORMULATION; PLASMON DISPERSION AB Theoretical descriptions of the spectrum of electronic excitations in real metals have not yet reached a fully predictive, 'first-principles' stage. In this paper we begin by presenting brief highlights of recent progress made in the evaluation of dynamical electronic response in metals. A comparison between calculated and measured spectra-we use the loss spectra of Al and Cs as test cases-leads us to the conclusion that, even in 'weakly-correlated' metals, correlation effects beyond mean-field theory play an important role. Furthermore, the effects of the underlying band structure turn out to be significant. Calculations which incorporate the effects of both dynamical correlations and band structure from first principles are not yet available. As a first step towards such a goal, we outline a numerical algorithm for the self-consistent solution of the Dyson equation for the one-particle Green's function. The self-energy is evaluated within the shielded-interaction approximation of Baym and Kadanoff. Our method, which is fully conserving, is a finite-temperature scheme which determines the Green's function and the self-energy at the Matsubara frequencies on the imaginary axis. The analytic continuation to real frequencies is performed via Pade approximants. We present results for the homogeneous electron gas which exemplify the importance of many-body self-consistency. C1 Univ Tennessee, Dept Phys & Astron, Knoxville, TN 37996 USA. Oak Ridge Natl Lab, Div Solid State, Oak Ridge, TN 37831 USA. RP Univ Tennessee, Dept Phys & Astron, Knoxville, TN 37996 USA. EM eguiluz@utk.edu NR 68 TC 11 Z9 11 U1 0 U2 2 PU TAYLOR & FRANCIS LTD PI ABINGDON PA 2-4 PARK SQUARE, MILTON PARK, ABINGDON OR14 4RN, OXON, ENGLAND SN 0026-8976 EI 1362-3028 J9 MOL PHYS JI Mol. Phys. PD MAY PY 1998 VL 94 IS 1 BP 87 EP 97 DI 10.1080/002689798168376 PG 11 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA ZN780 UT WOS:000073681900009 ER PT J AU Gnedin, NY Hui, L AF Gnedin, NY Hui, L TI Probing the Universe with the Ly alpha forest - I. Hydrodynamics of the low-density intergalactic medium SO MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY LA English DT Article DE hydrodynamics; methods, numerical; intergalactic medium; quasars, absorption lines; cosmology, theory ID CLOUDS; MODEL AB We introduce an efficient and accurate alternative to full hydrodynamic simulations, hydro-PM (HPM), for the study of the low column density Ly alpha forest (N-HI less than or similar to 10(14) cm(-2)). It consists of a particle mesh (PM) solver, modified to compute, in addition to the gravitational potential, an effective potential due to the gas pressure. Such an effective potential can be computed from the density field because of a tight correlation between density and pressure in the low-density limit (delta less than or similar to 10), which can be calculated for any photo-re-ionization history by a method outlined by Hui & Gnedin. Such a correlation exists, in part, because of minimal shock heating in the low-density limit. We compare carefully the density and velocity fields as well as absorption spectra, computed using HPM versus hydrodynamic simulations, and find good agreement. We show that HPM is capable of reproducing measurable quantities, such as the column density distribution, computed from full hydrodynamic simulations, to a precision comparable to that of observations. We discuss how, by virtue of its speed and accuracy, HPM can enable us to use the Ly alpha forest as a cosmological probe. We also discuss in detail the smoothing of the gas (or baryon) fluctuation relative to that of the dark matter on small scales due to finite gas pressure. First, it is shown that the conventional wisdom that the linear gas fluctuation is smoothed on the Jeans scale is incorrect for general re-ionization (or reheating) history; the correct linear filtering scale is in general smaller than the Jeans scale after reheating, but larger prior to it. Secondly, it is demonstrated that in the mildly non-linear regime, a PM solver, combined with suitable pre-filtering of the initial conditions, can be used to model the low-density IGM. However, such an approximation is shown to be less accurate than HPM, unless a non-uniform pre-filtering scheme is implemented. C1 Univ Calif Berkeley, Dept Astron, Berkeley, CA 94720 USA. Fermi Natl Accelerator Lab, NASA, Fermilab Astrophys Ctr, Batavia, IL 60510 USA. RP Gnedin, NY (reprint author), Univ Calif Berkeley, Dept Astron, 601 Campbell Hall, Berkeley, CA 94720 USA. NR 38 TC 250 Z9 251 U1 0 U2 2 PU BLACKWELL SCIENCE LTD PI OXFORD PA P O BOX 88, OSNEY MEAD, OXFORD OX2 0NE, OXON, ENGLAND SN 0035-8711 J9 MON NOT R ASTRON SOC JI Mon. Not. Roy. Astron. Soc. PD MAY 1 PY 1998 VL 296 IS 1 BP 44 EP 55 DI 10.1046/j.1365-8711.1998.01249.x PG 12 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA ZP885 UT WOS:000073798400011 ER PT J AU Drinkwater, MJ Gregg, MD AF Drinkwater, MJ Gregg, MD TI High surface brightness dwarf galaxies in the Fornax cluster SO MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY LA English DT Letter DE galaxies, clusters, individual, Fornax; galaxies, compact; galaxies, formation; galaxies, luminosity function, mass function ID ELLIPTICAL GALAXIES; VIRGO CLUSTER; PHOTOMETRY; POPULATION; ORIGIN AB We describe a search for compact dwarf galaxies in the Fornax cluster using the FLAIR spectrograph on the UK Schmidt Telescope. We measured radial velocities of 453 compact galaxies brighter than B-T approximate to 17.3 and found seven new compact dwarf cluster members that were not classified in previous surveys as members of the cluster. These are amongst the most compact, high surface brightness dwarf galaxies known. The inclusion of these galaxies in the cluster does not change the total luminosity function significantly, but they are important because of their extreme nature; one in particular appears to be a dwarf spiral. Three of the new dwarfs have strong emission lines and we identify them as blue compact dwarfs (BCDs), doubling the number of confirmed BCDs in the cluster. We also determined that none of the compact dwarf elliptical (M32-like) candidates is in the cluster, down to an absolute magnitude M-B = -13.2. We have investigated the claim of Irwin et al. that there is no strong relation between surface brightness and magnitude for the cluster members and find some support for this for the brighter galaxies (B-T < 17.3), but fainter galaxies still need to be measured. C1 Univ New S Wales, Sch Phys, Sydney, NSW 2052, Australia. Univ Calif Davis, Dept Phys, Davis, CA 95616 USA. Univ Calif Lawrence Livermore Natl Lab, Inst Geophys & Planetary Phys, Livermore, CA 94550 USA. RP Drinkwater, MJ (reprint author), Univ New S Wales, Sch Phys, Sydney, NSW 2052, Australia. RI Drinkwater, Michael/A-2201-2008 OI Drinkwater, Michael/0000-0003-4867-0022 NR 20 TC 24 Z9 24 U1 0 U2 0 PU BLACKWELL SCIENCE LTD PI OXFORD PA P O BOX 88, OSNEY MEAD, OXFORD OX2 0NE, OXON, ENGLAND SN 0035-8711 J9 MON NOT R ASTRON SOC JI Mon. Not. Roy. Astron. Soc. PD MAY 1 PY 1998 VL 296 IS 1 BP L15 EP L19 DI 10.1046/j.1365-8711.1998.01578.x PG 5 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA ZP885 UT WOS:000073798400004 ER PT J AU Johnson, KL Tucker, JD Nath, J AF Johnson, KL Tucker, JD Nath, J TI Frequency, distribution and clonality of chromosome damage in human lymphocytes by multi-color FISH SO MUTAGENESIS LA English DT Article ID IN-SITU HYBRIDIZATION; PRADER-WILLI SYNDROME; FLUORESCENCE INSITU HYBRIDIZATION; DNA PROBES; UNBALANCED TRANSLOCATION; STRUCTURAL-ABERRATIONS; BIOLOGICAL DOSIMETRY; IONIZING-RADIATION; TELOMERIC SITES; GAMMA-RADIATION AB Whole chromosome painting was used to determine whether the use of different sets of paints would influence results obtained from the analysis of human peripheral blood lymphocytes from 27 healthy unexposed subjects, Painting was also used to determine if aberration frequencies are proportional to the size of selected chromosomes in human lymphocytes irradiated in vitro. The in vitro results showed that the frequencies of radiation-induced stable aberrations (i.e. translocations and insertions) in chromosomes 3, 5 and 6 painted in unique colors are proportional to chromosome size, Aberration frequencies in the normal subjects were measured using two different sets of paints, one set for chromosomes 3, 5 and 6 where each chromosome was labeled in a unique color and one set where chromosomes 1, 2 and 4 were painted in a single color. The frequency of aberrations among chromosomes 1-6 in the population as a whole was also found to be proportional to chromosome size. However, some individual subjects had a distribution of damage that was not proportional to chromosome size due to the presence of clones of abnormal cells. Aberration frequencies measured in chromosomes 3, 5 and 6 as a set were highly correlated with those observed in chromosomes 1, 2 and 4 as a set, after adjusting for the different amounts of the genome that were painted. We also determined whether differences exist in the aberration frequencies measured by two scoring systems: the classical method, where reciprocal exchanges are scored as single events, and PAINT, where each break junction is scored as a single event. The two scoring systems gave highly correlated results for translocations and differed by a constant value (PAINTx0.58 = classical method), Approximately 27% of translocations were observed to be nonreciprocal due to a failure to detect exchanges involving small amounts of material or to a non-reciprocal exchange mechanism. Our results support the hypothesis that cytogenetic evaluations for biodosimetry can be performed with any one or more of the chromosomes studied here and indicate that the aberration frequency measurements are independent of the scoring system selected for the evaluation. We also present a simple statistical method for identifying subjects that may possess clonal aberrations. C1 W Virginia Univ, Genet & Dev Biol Program, Morgantown, WV 26506 USA. Lawrence Livermore Natl Lab, Biol & Biotechnol Res Program, Livermore, CA 94551 USA. RP Nath, J (reprint author), W Virginia Univ, Genet & Dev Biol Program, Morgantown, WV 26506 USA. EM jnath@caf.wvu.edu NR 64 TC 43 Z9 43 U1 1 U2 1 PU OXFORD UNIV PRESS PI OXFORD PA GREAT CLARENDON ST, OXFORD OX2 6DP, ENGLAND SN 0267-8357 J9 MUTAGENESIS JI Mutagenesis PD MAY PY 1998 VL 13 IS 3 BP 217 EP 227 DI 10.1093/mutage/13.3.217 PG 11 WC Genetics & Heredity; Toxicology SC Genetics & Heredity; Toxicology GA ZQ692 UT WOS:000073893500002 PM 9643579 ER PT J AU Livne, Z Munitz, A Rawers, JC Fields, RJ AF Livne, Z Munitz, A Rawers, JC Fields, RJ TI Consolidation of nanoscale iron powders SO NANOSTRUCTURED MATERIALS LA English DT Article ID NANOCRYSTALLINE MATERIALS; COMPACTION; ALLOYS AB The consolidation behavior of two types of nanoscale iron powders- vacuum condensed (nanograins in nanoparticles) and ball-nulled (nanograins BI microparticles), was studied. The consolidation of two microscale powders, atomized and ground, was also characterized for comparison. Consolidation techniques investigated were cold closed die-compaction, cold isostatic pressing (CIPing), and after CIPing, sintering or hot isostatic pressing (HIPing). The mechanical properties, density, and microstructure of the resulting compacts were found to depend on the original powder type and its consolidation history. Significant differences were found between the microscale and nanoscale powders. AII additional reason, besides the dissimilarity in grain size, for the differences observed relates to the fact that the nanograin powders contained! significant amounts of oxygen, which ultimately resulted in a distinctly two-phase bulk microstructure. The vacuum condensed powder achieved satisfactory green strength on CIPing, and high hardness (440 H-V) oil low temperature sintering. While unnecessary for complete consolidation, HIPing at 500 degrees C was found to be beneficial and compacts of this powder thus tl-eared were found to have a hardness of 520 Hv and high compressive yield strength (1800 MPa). For ball-milled powders, HIPing was found to be essential for achieving effective consolidation: ball-milled material, which remained friable after CIPing and sintering at 580 degrees C, achieved exceptionally high hardness (820 H-V) when HIPed at 580 degrees C and 175 MPa. The ductility was greatly improved when HIPed at temperatures between 700 degrees C and 850 degrees C, while preserving its relatively high strength. The behavior of these nanoscale powders can be understood by invoking the usual densification, particle bonding, and grain growth mechanisms. Optimization of these processes may result in unique mechanical properties of ball milled powders. (C) 1998 Acta Metallurgica Inc. C1 Nucl Res Ctr Negev, IL-84190 Beer Sheva, Israel. US Dept Energy, Albany, OR 97321 USA. Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Livne, Z (reprint author), Nucl Res Ctr Negev, POB 9001, IL-84190 Beer Sheva, Israel. NR 15 TC 20 Z9 21 U1 0 U2 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0965-9773 J9 NANOSTRUCT MATER JI Nanostruct. Mater. PD MAY PY 1998 VL 10 IS 4 BP 503 EP 522 DI 10.1016/S0965-9773(98)00094-4 PG 20 WC Materials Science, Multidisciplinary SC Materials Science GA 116QF UT WOS:000075735500001 ER PT J AU Qin, LC Zhou, D Krauss, AR Gruen, DM AF Qin, LC Zhou, D Krauss, AR Gruen, DM TI TEM characterization of nanodiamond thin films SO NANOSTRUCTURED MATERIALS LA English DT Article ID CHEMICAL-VAPOR-DEPOSITION; DIAMOND FILMS; GROWTH AB The microstructure of thin films grown by microwave plasma-enhanced chemical vapor deposition (MPCVD) from fullerene C-60 precursors has been characterized by scanning electron microscopy (SEM), selected-area electron diffraction (SAED), bright-field electron microscopy, high-resolution electron microscopy(HREM), and parallel electron energy-loss spectroscopy (PEELS). The films are composed of nanosize crystallites of diamond, and no graphitic or amorphous phases were observed. The diamond crystallite size measured from lattice images shows that most grains range between 3-5 rtm, reflecting a gamma distribution. SAED gave no evidence of either sp(2)-bonded glassy carbon or sp(3)-bonded diamondlike amorphous carbon. The sp(2)-bonded configuration found in PEELS was attributed to grain boundary carbon atoms, which constitute 5-10% of the total. Occasionally observed larger diamond grains tend to be highly faulted. (C) 1998 Acta Metallurgica Inc. C1 Argonne Natl Lab, Div Mat & Chem Sci, Argonne, IL 60439 USA. RP Qin, LC (reprint author), IBM Corp, 5600 Cottle Rd, San Jose, CA 95193 USA. NR 11 TC 59 Z9 61 U1 2 U2 26 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0965-9773 J9 NANOSTRUCT MATER JI Nanostruct. Mater. PD MAY PY 1998 VL 10 IS 4 BP 649 EP 660 DI 10.1016/S0965-9773(98)00092-0 PG 12 WC Materials Science, Multidisciplinary SC Materials Science GA 116QF UT WOS:000075735500013 ER PT J AU Gilmanshin, R Callender, RH Dyer, RB AF Gilmanshin, R Callender, RH Dyer, RB TI The core of apomyoglobin E-form folds at the diffusion limit SO NATURE STRUCTURAL BIOLOGY LA English DT Article ID MOLTEN GLOBULE INTERMEDIATE; PROTEIN; STATES; EVENTS AB The E-form of apomyoglobin has been characterized using infrared and fluorescence spectroscopies, revealing a compact core with native like contacts, most probably consisting of 15-20 residues of the A, G and H helices of apomyoglobin. Fast temperature-jump, time-resolved infrared measurements reveal that the core is formed within 96 mu s at 46 degrees C, close to the diffusion limit for loop formation. Remarkably, the folding pathway of the E-form is such that the formation of a limited number of native-like contacts is not rate limiting, or that the contacts form on the same time scale expected for diffusion controlled loop formation. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Yeshiva Univ Albert Einstein Coll Med, Dept Biochem, Bronx, NY 10461 USA. RP Dyer, RB (reprint author), Univ Calif Los Alamos Natl Lab, CST-4,Mail Stop J586, Los Alamos, NM 87545 USA. EM bdyer@lanl.gov NR 18 TC 39 Z9 39 U1 0 U2 4 PU NATURE AMERICA INC PI NEW YORK PA 345 PARK AVE SOUTH, NEW YORK, NY 10010-1707 USA SN 1072-8368 J9 NAT STRUCT BIOL JI Nat. Struct. Biol. PD MAY PY 1998 VL 5 IS 5 BP 363 EP 365 DI 10.1038/nsb0598-363 PG 3 WC Biochemistry & Molecular Biology; Biophysics; Cell Biology SC Biochemistry & Molecular Biology; Biophysics; Cell Biology GA ZL597 UT WOS:000073450300012 PM 9586997 ER PT J AU Norby, RJ AF Norby, RJ TI Nitrogen deposition: a component of global change analyses SO NEW PHYTOLOGIST LA English DT Article; Proceedings Paper CT 3rd New Phytologist Symposium on Major Biological Issues Resulting from Anthropogenic Disturbance of the Nitrogen Cycle CY SEP 03-05, 1997 CL LANCASTER UNIV, LANCASTER, ENGLAND HO LANCASTER UNIV DE atmospheric carbon dioxide; C : N ratio; global carbon cycle; global change; nitrogen deposition ID ATMOSPHERIC CARBON-DIOXIDE; TERRESTRIAL ECOSYSTEMS; FOREST ECOSYSTEMS; CO2 CONCENTRATION; LOBLOLLY-PINE; ELEVATED CO2; LEAF-AREA; RESPONSES; PHOTOSYNTHESIS; PRODUCTIVITY AB The global cycles of carbon and nitrogen are being perturbed by human activities that increase the transfer from large pools of non-reactive forms of the elements to reactive forms that are essential to the functioning of the terrestrial biosphere. The cycles are closely linked at all scales, and global change analyses must consider C and N cycles together. The increasing amount of N originating from fossil fuel combustion and deposited to terrestrial ecosystems as nitrogen oxides could increase the capacity of ecosystems to sequester C, thereby removing some of the excess carbon dioxide from the atmosphere and slowing the development of greenhouse warming. Several global and ecosystem models have calculated the amount of C sequestration that can be attributed to N deposition, based on assumptions about the allocation of N among ecosystem components with different C:N ratios. They support the premise that, since industrialization began, N deposition has been responsible for an increasing terrestrial C sink, but there is great uncertainty whether ecosystems will continue to retain exogenous N. Whether terrestrial ecosystems continue to sequester additional C will depend in part on their response to increasing concentrations of atmospheric carbon dioxide, widely thought to be constrained by limited N availability. Ecosystem models generally support the conclusion that responses to increasing concentrations of carbon dioxide will be greater, and the range of possible responses will be wider, in ecosystems where increased N inputs originate as atmospheric deposition. The interactions between N deposition and increasing carbon dioxide concentrations could be altered considerably, however, by additional factors, including N saturation of ecosystems, changes in community composition, and climate change, Nitrogen deposition is also linked to global change issues through the volatile losses of nitrous oxide, which is a potent greenhouse gas, and the role of nitrogen oxides in the production of tropospheric ozone, which could interact with plant responses to elevated carbon dioxide. Any consideration of the role of N deposition in global change issues must also balance the projected responses against the serious detrimental impact of excess N on the environment. C1 Oak Ridge Natl Lab, Div Environm Sci, Oak Ridge, TN 37831 USA. RP Norby, RJ (reprint author), Oak Ridge Natl Lab, Div Environm Sci, POB 2008, Oak Ridge, TN 37831 USA. RI Norby, Richard/C-1773-2012 OI Norby, Richard/0000-0002-0238-9828 NR 68 TC 56 Z9 60 U1 3 U2 24 PU CAMBRIDGE UNIV PRESS PI NEW YORK PA 40 WEST 20TH STREET, NEW YORK, NY 10011-4211 USA SN 0028-646X J9 NEW PHYTOL JI New Phytol. PD MAY PY 1998 VL 139 IS 1 BP 189 EP 200 DI 10.1046/j.1469-8137.1998.00183.x PG 12 WC Plant Sciences SC Plant Sciences GA ZU478 UT WOS:000074202000019 ER PT J AU Fleckinger-Pelle, J Kaper, HG Takac, P AF Fleckinger-Pelle, J Kaper, HG Takac, P TI Dynamics of the Ginzburg-Landau equations of superconductivity SO NONLINEAR ANALYSIS-THEORY METHODS & APPLICATIONS LA English DT Article DE Ginzburg-Landau equations; superconductivity; gauge; weak solutions; global existence; uniqueness; dynamical process; global attractor ID MODEL C1 Univ Toulouse 3, UMR MIP, F-31042 Toulouse, France. Univ Toulouse 1, CEREMATH, F-31042 Toulouse, France. Argonne Natl Lab, Div Math & Comp Sci, Argonne, IL 60439 USA. Univ Rostock, Fachbereich Math, D-18055 Rostock, Germany. RP Fleckinger-Pelle, J (reprint author), Univ Toulouse 3, UMR MIP, Pl Anatole France, F-31042 Toulouse, France. NR 25 TC 18 Z9 18 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0362-546X EI 1873-5215 J9 NONLINEAR ANAL-THEOR JI Nonlinear Anal.-Theory Methods Appl. PD MAY PY 1998 VL 32 IS 5 BP 647 EP 665 DI 10.1016/S0362-546X(97)00508-7 PG 19 WC Mathematics, Applied; Mathematics SC Mathematics GA ZD454 UT WOS:000072687600006 ER PT J AU Krauss, PD Naus, DJ AF Krauss, PD Naus, DJ TI Repair materials and techniques for concrete structures in nuclear power plants SO NUCLEAR ENGINEERING AND DESIGN LA English DT Article; Proceedings Paper CT 6th Symposium on Current Issues Related to Nuclear Power Plant Structures, Equipment and Piping CY DEC 04-06, 1996 CL RALEIGH, NORTH CAROLINA SP N Carolina State Univ, Ctr Nucl Power Plant Struct Equipment & Piping, US Nucl Regulatory Commiss AB The paper summaries portions of work of the Structural Aging Program, sponsored by the Nuclear Regulatory Commission (NRC). The paper addresses the assessment and repair of concrete structures in nuclear power plants. It presents the results of a survey of the the nuclear power plants in the United States to identify susceptible concrete components, rates of occurrence of deterioration, and to determine the durability of repairs. The paper describes deterioration mechanisms and discusses their effect. Repair techniques are described. Evaluation techniques and nondestructive test techniques are also discussed. (C) 1998 Elsevier Science S.A. All rights reserved. C1 Wiss Janney Elstner Associates Inc, Northbrook, IL 60062 USA. Martin Marietta Energy Syst Inc, Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Krauss, PD (reprint author), Wiss Janney Elstner Associates Inc, 330 Pfingsten Rd, Northbrook, IL 60062 USA. NR 30 TC 0 Z9 0 U1 1 U2 2 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0029-5493 J9 NUCL ENG DES JI Nucl. Eng. Des. PD MAY PY 1998 VL 181 IS 1-3 BP 71 EP 89 DI 10.1016/S0029-5493(97)00336-1 PG 19 WC Nuclear Science & Technology SC Nuclear Science & Technology GA ZW714 UT WOS:000074440300007 ER PT J AU Ho, DDM Harte, JA Tabak, M AF Ho, DDM Harte, JA Tabak, M TI Two dimensional simulations of a radiation driven target with two sided illumination for heavy ion fusion SO NUCLEAR FUSION LA English DT Article ID ICF TARGETS; SYMMETRIZATION AB The conventional configuration of a radiation driven target for heavy ion fusion is a quasi-cylindrical hohlraum containing a fusion capsule with radiation converters placed at opposite ends of the hohlraum. Ion beams enter each converter from opposite directions and are stopped by the material inside the converters. The first comprehensive two dimensional (2-D) simulations are presented for this configuration using the radiation hydrodynamics code LASNEX. The fusion capsule inside the hohlraum absorbs 1 MJ of radiation energy and can give a yield of 430 MJ if the illumination symmetry condition and the pulse shape requirements are satisfied. To drive this capsule, the total ion beam energy input into the hohlraum is about 22 MJ, which results in a target gain of only about 20. This yield is substantially lower than the previous estimate of greater than 80. The reason is that the initial length of the converters has to be reasonably long to prevent the hot beam stopping material from leaking into the hohlraum and causing unacceptable implosion asymmetry, without other target modifications. Furthermore, as the beam stopping material inside the converters is being heated, ii; expands substantially in the axial direction. This stretches the length of the converters, and, consequently, the ratio of opening area to volume of the converters decreases. These factors make it difficult for the radiation to escape from the converters and substantially reduce the efficiency of converting ion beam energy into radiation. It is concluded that the gain of this type of target is too low for commercial fusion and an alternative hohlraum configuration that can provide higher gain should therefore be sought. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Ho, DDM (reprint author), Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. NR 15 TC 4 Z9 4 U1 0 U2 0 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 MAY PY 1998 VL 38 IS 5 BP 701 EP 709 DI 10.1088/0029-5515/38/5/305 PG 9 WC Physics, Fluids & Plasmas SC Physics GA ZV537 UT WOS:000074314900005 ER PT J AU Zweben, SJ Darrow, DS Batha, SH Budny, RV Diesso, M Herrmann, HW Giarrusso, J Redi, MH Takahashi, H Von Goeler, S White, RB Wieland, RM AF Zweben, SJ Darrow, DS Batha, SH Budny, RV Diesso, M Herrmann, HW Giarrusso, J Redi, MH Takahashi, H Von Goeler, S White, RB Wieland, RM TI Effects of q(r) on the alpha particle ripple loss in TFTR SO NUCLEAR FUSION LA English DT Article ID FUSION TEST REACTOR; FAST IONS; DT EXPERIMENTS; FIELD RIPPLE; TOKAMAKS; PRODUCTS; MIDPLANE; RECONSTRUCTION; DIFFUSION; PROFILE AB An experiment was done with TFTR DT plasmas to measure the effect of the q(r) profile on the alpha particle ripple loss using a radially movable scintillator detector 20 degrees below the outer midplane. The experimental results were compared with toroidal field (TF) ripple loss calculations done using a Monte Carlo guiding centre orbit following code (ORBIT). Although some of the experimental results are consistent with the ORBIT code modelling, the measured variation of the alpha particle loss with q(r) could not be explained by this code. This inconsistency is most likely due to the effect of limiter shadowing on alpha particle diffusion into this detector, which cannot be modelled with ORBIT. C1 Princeton Univ, Princeton Plasma Phys Lab, Princeton, NJ 08543 USA. RP Zweben, SJ (reprint author), Princeton Univ, Princeton Plasma Phys Lab, POB 451, Princeton, NJ 08543 USA. RI White, Roscoe/D-1773-2013 OI White, Roscoe/0000-0002-4239-2685 NR 35 TC 11 Z9 11 U1 0 U2 8 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 MAY PY 1998 VL 38 IS 5 BP 739 EP 760 DI 10.1088/0029-5515/38/5/308 PG 22 WC Physics, Fluids & Plasmas SC Physics GA ZV537 UT WOS:000074314900008 ER PT J AU Dunietz, I AF Dunietz, I TI Beautiful CP violation SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 5th International Workshop on B-Physics at Hadron Machines (BEAUTY 97) CY OCT 13-17, 1997 CL UNIV CALIFORNIA LOS ANGELES, LOS ANGELES, CALIFORNIA HO UNIV CALIFORNIA LOS ANGELES ID ANGULAR-DISTRIBUTIONS; B-DECAYS; ASYMMETRY; GAMMA; PHASE AB CP violation is observed to date only in K-0 decays and is parameterizable by a single quantity epsilon. Because it is one of the least understood phenomena in the Standard Model and holds a clue to baryogenesis, it must be investigated further. Highly specialized searches in K-0 decays are possible. Effects in B decays are much larger. In addition to the traditional B-d --> J/psi K-s, pi(+)pi(-) asymmetries, CP violation could be searched for in already existing inclusive B data samples. The rapid B-s - (B) over bar(s) oscillations cancel in untagged B-s data samples. which therefore allow feasibility studies for the observation of CP violation and the extraction of CKM elements with present vertex detectors. The favored method for the extraction of the CRM angle gamma is shown to be unfeasible and a solution is presented involving striking direct CP violation in charged B decays. Novel methods for determining the B-s mixing parameter Delta m are described without the traditional requirement of flavor-specific final states. The CKM phase phi = - 2 beta - gamma = - pi + alpha - beta can be obtained from time-dependent studies of B-d(t) --> D(*)(+/-)pi(-/+) even in the presence of possible final-state interactions. (C) 1998 Published by Elsevier Science B.V. All rights reserved. C1 Fermi Natl Accelerator Lab, Batavia, IL 60510 USA. RP Dunietz, I (reprint author), Fermi Natl Accelerator Lab, POB 500, Batavia, IL 60510 USA. NR 51 TC 6 Z9 6 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD MAY 1 PY 1998 VL 408 IS 1 BP 14 EP 20 DI 10.1016/S0168-9002(98)00327-1 PG 7 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA ZX488 UT WOS:000074521200004 ER PT J AU Kasper, P AF Kasper, P CA BTeV Collaboration TI Physics prospects at BTeV SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 5th International Workshop on B-Physics at Hadron Machines (BEAUTY 97) CY OCT 13-17, 1997 CL UNIV CALIFORNIA LOS ANGELES, LOS ANGELES, CALIFORNIA HO UNIV CALIFORNIA LOS ANGELES AB BTeV is a proposed forward collider program at the Fermilab Tevatron dedicated to precision studies of CP violation, mixing and fare decays of beauty and charm hadrons. (C) 1998 Elsevier Science B.V. All rights reserved. C1 Fermi Natl Accelerator Lab, Batavia, IL 60510 USA. RP Kasper, P (reprint author), Fermi Natl Accelerator Lab, POB 500, Batavia, IL 60510 USA. NR 19 TC 3 Z9 3 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 MAY 1 PY 1998 VL 408 IS 1 BP 146 EP 153 DI 10.1016/S0168-9002(98)00256-3 PG 8 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA ZX488 UT WOS:000074521200020 ER PT J AU Schwiening, J AF Schwiening, J CA BABAR-DIRC Collaboration TI DIRC, a new type of particle identification system for BABAR SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 5th International Workshop on B-Physics at Hadron Machines (BEAUTY 97) CY OCT 13-17, 1997 CL UNIV CALIFORNIA LOS ANGELES, LOS ANGELES, CALIFORNIA HO UNIV CALIFORNIA LOS ANGELES AB The DIRC, a new type of Cherenkov imaging device, has been selected as the primary particle identification system for the BABAR detector at the asymmetric B-factory, Per-II. It is based on total internal reflection and uses long, rectangular bars made from synthetic fused silica as Cherenkov radiators and light guides. In this paper, the principles of the DIRC ring imaging Cherenkov technique are explained and results from the prototype program are presented. The studies of the optical properties and radiation hardness of the quartz radiators are described, followed by a discussion of the detector design. (C) 1998 Elsevier Science B.V. All rights reserved. C1 Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. RP Schwiening, J (reprint author), Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. EM jochen@slac.stanford.edu 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 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD MAY 1 PY 1998 VL 408 IS 1 BP 211 EP 220 DI 10.1016/S0168-9002(98)00245-9 PG 10 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA ZX488 UT WOS:000074521200028 ER PT J AU Kwan, S AF Kwan, S CA BTeV Collaboration TI BTeV: pixel development and triggering SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 5th International Workshop on B-Physics at Hadron Machines (BEAUTY 97) CY OCT 13-17, 1997 CL UNIV CALIFORNIA LOS ANGELES, LOS ANGELES, CALIFORNIA HO UNIV CALIFORNIA LOS ANGELES AB The BTeV vertex detector and trigger system are described. The vertex detector is based on planar pixel arrays. The information from the pixel planes will be used in the Level 1 trigger. Recent startup effort on pixel R&D at Fermilab will also be summarized. (C) 1998 Elsevier Science B.V. All rights reserved. C1 Fermi Natl Accelerator Lab, Batavia, IL 60510 USA. RP Kwan, S (reprint author), Fermi Natl Accelerator Lab, POB 500, Batavia, IL 60510 USA. NR 7 TC 5 Z9 5 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 MAY 1 PY 1998 VL 408 IS 1 BP 235 EP 241 DI 10.1016/S0168-9002(98)00320-9 PG 7 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA ZX488 UT WOS:000074521200031 ER PT J AU Jackson, GP AF Jackson, GP TI A dedicated hadronic B-factory: accelerator considerations SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 5th International Workshop on B-Physics at Hadron Machines (BEAUTY 97) CY OCT 13-17, 1997 CL UNIV CALIFORNIA LOS ANGELES, LOS ANGELES, CALIFORNIA HO UNIV CALIFORNIA LOS ANGELES AB There is interest in the high-energy physics program at a dedicated hadronic B-factory. After general considerations are explored for such a facility, a potential implementation at the Fermi National Accelerator Laboratory ia presented. (C) 1998 Elsevier Science B.V. All rights reserved. C1 Fermi Natl Accelerator Lab, Batavia, IL 60510 USA. RP Jackson, GP (reprint author), Fermi Natl Accelerator Lab, POB 500,MS 306, Batavia, IL 60510 USA. NR 7 TC 2 Z9 2 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD MAY 1 PY 1998 VL 408 IS 1 BP 296 EP 307 DI 10.1016/S0168-9002(98)00336-2 PG 12 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA ZX488 UT WOS:000074521200039 ER PT J AU Windl, W Lenosky, TJ Kress, JD Voter, AF AF Windl, W Lenosky, TJ Kress, JD Voter, AF TI First-principles investigation of radiation induced defects in Si and SiC SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS LA English DT Article; Proceedings Paper CT 9th International Conference on Radiation Effects in Insulators (REI-9) CY SEP 14-19, 1997 CL KNOXVILLE, TENNESSEE SP Ctr Mat Proc at Univ TN, Pacific NW Natl Lab DE radiation damage; ab initio calculation; silicon; silicon carbide ID MOLECULAR-DYNAMICS; SILICON; DIFFUSION AB We have calculated the displacement-threshold energies for the main symmetry directions in Si and SiC using a self-consistent first-principles method. We show that - depending on the knock-on direction - 64-atom simulation cells can be sufficient to allow a nearly finite-size-effect-free calculation, thus making the use of first-principles methods possible. We use molecular dynamics (MD) techniques and propose the use of a sudden approximation which agrees reasonably well with the MD results for selected directions and which allows estimates of displacement-threshold energies without employing an MD simulation. (C) 1998 Elsevier Science B.V. All rights reserved. C1 Univ Calif Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. RP Windl, W (reprint author), Univ Calif Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. RI Windl, Wolfgang/C-7255-2012 OI Windl, Wolfgang/0000-0001-5892-0684 NR 21 TC 42 Z9 42 U1 4 U2 13 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 MAY PY 1998 VL 141 IS 1-4 BP 61 EP 65 DI 10.1016/S0168-583X(98)00082-2 PG 5 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Atomic, Molecular & Chemical; Physics, Nuclear SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 103WA UT WOS:000074979800008 ER PT J AU Williford, RE Devanathan, R Weber, WJ AF Williford, RE Devanathan, R Weber, WJ TI Computer simulation of displacement energies for several ceramic materials SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS LA English DT Article; Proceedings Paper CT 9th International Conference on Radiation Effects in Insulators (REI-9) CY SEP 14-19, 1997 CL KNOXVILLE, TENNESSEE SP Ctr Mat Proc at Univ TN, Pacific NW Natl Lab DE radiation damage; displacement energies; ceramics; GULP code ID IRRADIATED MAGNESIUM ALUMINATE; INTERATOMIC POTENTIALS; WEAPONS PLUTONIUM; ZIRCON; MGAL2O4; OXIDES; DAMAGE AB Displacement energies (E-d) are fundamental parameters controlling the production of radiation damage in materials, and as such, are useful for understanding and modeling the effects of radiation on materials. These energies are not easily determined experimentally for many ceramic materials. However, advances in computational methodologies and their application to ceramic materials provide a means to determine these energies in a number of materials of interest. Although computationally intensive molecular dynamics methods can be used to determine E-d for the various cations and anions, energy minimization methods can also provide a more expedient means to obtain reasonable estimates of these energies. In this paper, the energy minimization code General Utility Lattice Program (GULP), which uses a Mott-Littleton approximation to simulate isolated defects in extended solids, is used to calculate displacement energies. The validity of using this code for these computations is established by calculating E-d for several ceramics for which these energies are known. Computational results are in good agreement with the experimental values for alumina, MgO, and ZnO, Results are also presented for two ceramic materials, zircon and spinel, for which there are little or no experimental values yet available. Published by Elsevier Science B.V. C1 Pacific NW Lab, Dept Mat Sci, Richland, WA 99352 USA. RP Williford, RE (reprint author), Pacific NW Lab, Dept Mat Sci, MS K2-44,POB 999, Richland, WA 99352 USA. RI Weber, William/A-4177-2008; Devanathan, Ram/C-7247-2008 OI Weber, William/0000-0002-9017-7365; Devanathan, Ram/0000-0001-8125-4237 NR 25 TC 39 Z9 40 U1 1 U2 25 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 MAY PY 1998 VL 141 IS 1-4 BP 94 EP 98 DI 10.1016/S0168-583X(98)00066-4 PG 5 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Atomic, Molecular & Chemical; Physics, Nuclear SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 103WA UT WOS:000074979800014 ER PT J AU Devanathan, R Weber, WJ de la Rubia, TD AF Devanathan, R Weber, WJ de la Rubia, TD TI Computer simulation of a 10 keV Si displacement cascade in SiC SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS LA English DT Article; Proceedings Paper CT 9th International Conference on Radiation Effects in Insulators (REI-9) CY SEP 14-19, 1997 CL KNOXVILLE, TN SP Ctr Mat Proc at Univ TN, Pacific NW Natl Lab DE SiC; molecular dynamics; damage cascade; Tersoff potential; radiation effects ID MOLECULAR-DYNAMICS; INDUCED AMORPHIZATION; SURFACES; DEFECTS AB The threshold energy for atomic displacement and the evolution of high-energy displacement cascades in beta-SiC have been examined using molecular dynamics simulations. A modified form of the Tersoff potential was used in combination with a repulsive potential obtained from density functional theory to describe the interactions between the atoms. The evolution of lattice damage in a 10 keV Si cascade was studied for about 10 ps. The system size varied from 8000 atoms for the displacement energy calculations to 192,000 atoms for the cascade simulations. The results indicate that the minimum displacement energy is about 36 eV for Si and 28 eV for C. The cascade lifetime was found to be of the order of 0.1 ps, and the surviving C vacancies and interstitials outnumbered the corresponding Si defects by a factor of about 3. These results are discussed in light of previous theoretical and experimental studies of radiation damage in SiC. (C) 1998 Elsevier Science B.V. All rights reserved. C1 Pacific NW Lab, Richland, WA 99352 USA. Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Pacific NW Lab, POB 999,MS K1-96, Richland, WA 99352 USA. EM ram@pnl.gov RI Weber, William/A-4177-2008; Devanathan, Ram/C-7247-2008 OI Weber, William/0000-0002-9017-7365; Devanathan, Ram/0000-0001-8125-4237 NR 17 TC 69 Z9 69 U1 1 U2 12 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-583X EI 1872-9584 J9 NUCL INSTRUM METH B JI Nucl. Instrum. Methods Phys. Res. Sect. B-Beam Interact. Mater. Atoms PD MAY PY 1998 VL 141 IS 1-4 BP 118 EP 122 DI 10.1016/S0168-583X(98)00084-6 PG 5 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Atomic, Molecular & Chemical; Physics, Nuclear SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 103WA UT WOS:000074979800017 ER PT J AU Snead, LL Zinkle, SJ Hay, JC Osborne, MC AF Snead, LL Zinkle, SJ Hay, JC Osborne, MC TI Amorphization of SiC under ion and neutron irradiation SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS LA English DT Article; Proceedings Paper CT 9th International Conference on Radiation Effects in Insulators (REI-9) CY SEP 14-19, 1997 CL KNOXVILLE, TN SP Ctr Mat Proc at Univ TN, Pacific NW Natl Lab DE SiC; amorphization; ion bombardment ID TO-AMORPHOUS TRANSITION; SILICON-CARBIDE; SINGLE-CRYSTALS; IMPLANTATION; RADIATION; CERAMICS; RECRYSTALLIZATION; GRAPHITE; DAMAGE AB This paper presents results on the microstructure and physical properties of SiC amorphized by both ion and neutron irradiation. Specifically, 0.56 MeV Si ions have been implanted in single crystal 6H-SiC from ambient through >200 degrees C and the critical threshold for amorphization was measured as a function of the irradiation temperature. From a high resolution transmission electron microscopy (HRTEM) study of the crystalline to amorphous transition region in these materials, elongated pockets of amorphous material oriented parallel to the free surface are observed. Single crystal 6H-SiC and hot pressed and sintered 6H and 3C SIC were neutron irradiated at approximately 70 degrees C to a dose of similar to 2.56 dpa causing complete amorphization. Property changes resulting from the crystal to amorphous transition in SiC include a density decrease of 10.8%, a hardness decrease from 38.7 to 21.0 GPa, and a decrease in elastic modulus from 528 to 292 GPa. Recrystallization of the amorphized, single crystal 6H-SiC appears to occur in two stages. In the temperature range of similar to 800-1000 degrees C, crystallites nucleate and slowly grow. In the temperature range of 1125-1150 degrees C spontaneous nucleation and rapid growth of crystallites occur. It is further noted that amorphized 6H (alpha) SIC recrystallizes to highly faulted fee (beta) SiC. (C) 1998 Published by Elsevier Science B.V. All rights reserved. C1 Oak Ridge Natl Lab, Div Met & Ceram, Oak Ridge, TN 37831 USA. RP Oak Ridge Natl Lab, Div Met & Ceram, Bldg 4508,MS6087, Oak Ridge, TN 37831 USA. EM z2n@ornl.gov OI Zinkle, Steven/0000-0003-2890-6915 NR 43 TC 122 Z9 125 U1 3 U2 50 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-583X EI 1872-9584 J9 NUCL INSTRUM METH B JI Nucl. Instrum. Methods Phys. Res. Sect. B-Beam Interact. Mater. Atoms PD MAY PY 1998 VL 141 IS 1-4 BP 123 EP 132 DI 10.1016/S0168-583X(98)00085-8 PG 10 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Atomic, Molecular & Chemical; Physics, Nuclear SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 103WA UT WOS:000074979800018 ER PT J AU Evelyn, AL Ila, D Zimmerman, RL Bhat, K Poker, DB Hensley, DK AF Evelyn, AL Ila, D Zimmerman, RL Bhat, K Poker, DB Hensley, DK TI Effects of MeV ions on PE and PVDC SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS LA English DT Article; Proceedings Paper CT 9th International Conference on Radiation Effects in Insulators (REI-9) CY SEP 14-19, 1997 CL KNOXVILLE, TENNESSEE SP Ctr Mat Proc at Univ TN, Pacific NW Natl Lab DE polyethylene; polyvinylidene chloride; alpha bombardment ID PHENOLFORMALDEHYDE; RESIN AB We studied the effects of 3.5 and 5.0 MeV alpha bombardment on polyethylene and polyvinylidene chloride, both of which have simple chemical structures. Using a thin polymer film stacking technique, we were able to map the effects of the MeV alpha particles in their track. The first layer of the thin polymer film stack experienced mostly the effects of the electronic energy deposited, and the last layer received mostly effects of the nuclear stopping. Using Raman microprobe analysis and by measuring the ratio of the formation of graphene structures (G-line) to the disordered (amorphous) carbon line (D-line), we were able to separate the severed bond effects at the end of the alpha particle tracks in the last polymer film layers from the effects of the electronic energy deposited in the first polymer film layers. The results are in agreement with our other measurements of each polymer film using FTIR, RES and resistance measurements. (C) 1998 Elsevier Science B.V. All rights reserved. C1 Alabama A&M Univ, Dept Nat & Phys Sci, Ctr Irradiat Mat, Normal, AL 35762 USA. Oak Ridge Natl Lab, Div Solid State, Oak Ridge, TN 37831 USA. RP Ila, D (reprint author), Alabama A&M Univ, Dept Nat & Phys Sci, Ctr Irradiat Mat, POB 1447, Normal, AL 35762 USA. RI Hensley, Dale/A-6282-2016 OI Hensley, Dale/0000-0001-8763-7765 NR 10 TC 15 Z9 15 U1 0 U2 4 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-583X J9 NUCL INSTRUM METH B JI Nucl. Instrum. Methods Phys. Res. Sect. B-Beam Interact. Mater. Atoms PD MAY PY 1998 VL 141 IS 1-4 BP 164 EP 168 DI 10.1016/S0168-583X(98)00153-0 PG 5 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Atomic, Molecular & Chemical; Physics, Nuclear SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 103WA UT WOS:000074979800025 ER PT J AU White, CW Budai, JD Withrow, SP Zhu, JG Sonder, E Zuhr, RA Meldrum, A Hembree, DM Henderson, DO Prawer, S AF White, CW Budai, JD Withrow, SP Zhu, JG Sonder, E Zuhr, RA Meldrum, A Hembree, DM Henderson, DO Prawer, S TI Encapsulated semiconductor nanocrystals formed in insulators by ion beam synthesis SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS LA English DT Article; Proceedings Paper CT 9th International Conference on Radiation Effects in Insulators (REI-9) CY SEP 14-19, 1997 CL KNOXVILLE, TENNESSEE SP Ctr Mat Proc at Univ TN, Pacific NW Natl Lab DE Si nanocrystals; photoluminescence; CdS nanocrystals; CdSe nanocrystals; ion beam synthesis ID OPTICAL-PROPERTIES; GAAS NANOCRYSTALS; ROOM-TEMPERATURE; QUANTUM DOTS; VISIBLE PHOTOLUMINESCENCE; GE NANOCRYSTALS; POROUS SILICON; IMPLANTATION; GLASS; SIO2 AB Both elemental and compound semiconductor nanocrystals have been formed in insulators by ion beam synthesis. Si nanocrystals in SiO2 give rise to strong optical absorption and intense photoluminescence (PL). The dose dependence of optical absorption provides evidence for size dependent changes in the Si nanocrystal bandgap due to quantum confinement, but the PL results suggest that surface or defect states play an important role in FL. CdS and CdSe nanocrystals have been formed in SiO2 and in Al2O3. Their structure, size, and optical properties are discussed. (C) 1998 Elsevier Science B.V. All rights reserved. C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. Oak Ridge Y 12 Plant, Oak Ridge, TN USA. Fisk Univ, Nashville, TN USA. Univ Melbourne, Parkville, Vic 3052, Australia. RP White, CW (reprint author), Oak Ridge Natl Lab, POB 2008, Oak Ridge, TN 37831 USA. EM xxt@ornl.gov RI Budai, John/R-9276-2016; OI Budai, John/0000-0002-7444-1306; PRAWER, STEVEN/0000-0002-4959-0828 NR 45 TC 119 Z9 120 U1 2 U2 7 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 MAY PY 1998 VL 141 IS 1-4 BP 228 EP 240 DI 10.1016/S0168-583X(98)00091-3 PG 13 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Atomic, Molecular & Chemical; Physics, Nuclear SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 103WA UT WOS:000074979800037 ER PT J AU Magruder, RH Zuhr, RA AF Magruder, RH Zuhr, RA TI Modification of the optical properties of Ag nanoclusters by sequential implantation of Sc(Ti) and O in silica SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS LA English DT Article; Proceedings Paper CT 9th International Conference on Radiation Effects in Insulators (REI-9) CY SEP 14-19, 1997 CL KNOXVILLE, TENNESSEE SP Ctr Mat Proc at Univ TN, Pacific NW Natl Lab DE optical absorption; ion implantation; silica ID GLASSES AB The implantation of Sc(Ti) and O results in the modification of the silica with polarizable Sc(Ti) ions. With annealing the Sc(Ti) ions are incorporated with the O in the network to form a Sc(Ti)-O-silicate layer. Subsequent implantation of Ag into this layer results in the formation of Ag metal nanocluster colloids with significantly modified optical properties compared to samples without the Sc(Ti) ions. The incorporation of the Sc(Ti) results in a shift in the wavelength of the surface plasmon resonance of the Ag nanoclusters and a change in the magnitude of the surface plasmon resonance absorption. The results are interpreted using effective medium theory. (C) 1998 Elsevier Science B.V. All rights reserved. C1 Belmont Univ, Dept Chem & Phys, Nashville, TN 37212 USA. Oak Ridge Natl Lab, Div Solid State, Oak Ridge, TN 37831 USA. RP Magruder, RH (reprint author), Belmont Univ, Dept Chem & Phys, 1900 Belmont Blvd, Nashville, TN 37212 USA. EM magruderr@belmont.edu NR 14 TC 11 Z9 12 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 MAY PY 1998 VL 141 IS 1-4 BP 256 EP 260 DI 10.1016/S0168-583X(98)00095-0 PG 5 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Atomic, Molecular & Chemical; Physics, Nuclear SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 103WA UT WOS:000074979800041 ER PT J AU Ueda, A Mu, R Tung, YS Wu, M Collins, WE Henderson, DO White, CW Zuhr, RA Budai, JD Meldrum, A Wang, PW Li, X AF Ueda, A Mu, R Tung, YS Wu, M Collins, WE Henderson, DO White, CW Zuhr, RA Budai, JD Meldrum, A Wang, PW Li, X TI Interaction of F-n-centers with gold nanocrystals produced by gold ion implantation in MgO single crystals SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS LA English DT Article; Proceedings Paper CT 9th International Conference on Radiation Effects in Insulators (REI-9) CY SEP 14-19, 1997 CL KNOXVILLE, TENNESSEE SP Ctr Mat Proc at Univ TN, Pacific NW Natl Lab DE ion implantation; surface plasmon; gold colloids; MgO; F-center; F-n-center; diffusion ID ATOMIC-FORCE MICROSCOPY; OPTICAL-PROPERTIES; ULTRAVIOLET AB Gold ions were implanted at an energy of 1.1 MeV into (1 0 0) oriented MgO single crystals. In order to form gold colloids from the as-implanted samples, the samples were annealed in three different kinds of atmospheres: (1) Ar only, (2) 10% H-2 + 90% Ar, and (3) 10% O-2 + 90% Ar. Annealing over 1200 degrees C enhanced the gold colloid formation as is evident from the appearance of the surface plasmon resonance band of gold. The surface plasmon bands of samples annealed in three kinds of atmospheres were found to be at 560 nm (Ar only), 524 nm (H-2 + Ar), and 560 nm (O-2 + Ar). The band positions of surface plasmon can be reversibly changed by an additional annealing. Fe3+ impurities in the MgO samples are utilized to monitor the degree of reduction or oxidation of the samples due to annealing. From the absorption measurements of Fe3+ band, the diffusion constants of F-centers were obtained, We found that the shifts of the surface plasmon bands are correlated with the F-center concentration and that the F-n-center (aggregates of F-centers) is responsible for the shifting of the surface plasmon bands. We propose a model to explain the shift of surface plasmon band. (C) 1998 Published by Elsevier Science B.V. All rights reserved. C1 Fisk Univ, Phys Chem Lab, Dept Phys, Nashville, TN 37208 USA. Oak Ridge Natl Lab, Div Solid State, Oak Ridge, TN 37830 USA. Univ Texas, Dept Phys, El Paso, TX 79968 USA. Jilin Univ, Dept Chem, Changchun 130023, Peoples R China. RP Henderson, DO (reprint author), Fisk Univ, Phys Chem Lab, Dept Phys, 1000 17th Ave N, Nashville, TN 37208 USA. RI Budai, John/R-9276-2016 OI Budai, John/0000-0002-7444-1306 NR 17 TC 30 Z9 32 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 MAY PY 1998 VL 141 IS 1-4 BP 261 EP 267 DI 10.1016/S0168-583X(98)00070-6 PG 7 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Atomic, Molecular & Chemical; Physics, Nuclear SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 103WA UT WOS:000074979800042 ER PT J AU Williams, EK Ila, D Sarkisov, S Curley, M Cochrane, JC Poker, DB Hensley, DK Borel, C AF Williams, EK Ila, D Sarkisov, S Curley, M Cochrane, JC Poker, DB Hensley, DK Borel, C TI Study of the effects of MeV Ag and Au implantation on the optical properties of LiNbO3 SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS LA English DT Article; Proceedings Paper CT 9th International Conference on Radiation Effects in Insulators (REI-9) CY SEP 14-19, 1997 CL KNOXVILLE, TENNESSEE SP Ctr Mat Proc at Univ TN, Pacific NW Natl Lab DE ion implantation; LiNbO3; nanoclusters; z-scan ID ION-IMPLANTATION; SILICA GLASS; BEAM AB We present the results of characterization of linear absorption and nonlinear refractive index of Au and Ag nanoclusters made by MeV ion implantation into LiNbO3, Ag was implanted at 1.5 MeV to fluences of 2 to 17 x 10(16)/cm(2) at room temperature. Au was implanted to fluences of 5-20 x 10(16)/cm(2) at an energy of 2.0 MeV. Optical absorption spectrometry indicated an absorption peak at 560 nm for the Au implanted samples after a 30 min heat treatment at 500 degrees C in air. The peak shifted to similar to 620 nm after heat treatment at 1000 degrees C. The Ag implanted samples had absorption peaks at 445-485 nm before heat treatment. After 500 degrees C heat treatment for 1 h the peaks decreased in height and shifted from 545 to 560 nm. Heat treatment at 800 degrees C was sufficient to return the Ag implanted crystals to a dear state. The size of the clusters was determined from the absorption peaks. The Ag clusters did not change appreciably in size with heat treatment. The Au clusters increased from 1 to 3 nm upon heat treatment at 1000 degrees C. Measurements of the nonlinear refractive indices were carried out using the z-scan method with a tunable dye laser pumped by a frequency doubled mode-locked Nd:YAG laser. The dye laser had a 4.5 ps pulse duration time and 76 MHz pulse repetition rate (575 nm). (C) 1998 Elsevier Science B.V. All rights reserved. C1 Howard J Foster Ctr Irradiat Mat, Dept Nat & Phys Sci, Normal, AL 35762 USA. Oak Ridge Natl Lab, Div Solid State, Oak Ridge, TN 37831 USA. Univ Lyon 1, F-69365 Lyon, France. RP Ila, D (reprint author), Howard J Foster Ctr Irradiat Mat, Dept Nat & Phys Sci, POB 1447, Normal, AL 35762 USA. EM ila@cim.aamu.edu RI Hensley, Dale/A-6282-2016 OI Hensley, Dale/0000-0001-8763-7765 NR 26 TC 15 Z9 15 U1 1 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-583X J9 NUCL INSTRUM METH B JI Nucl. Instrum. Methods Phys. Res. Sect. B-Beam Interact. Mater. Atoms PD MAY PY 1998 VL 141 IS 1-4 BP 268 EP 273 DI 10.1016/S0168-583X(98)00150-5 PG 6 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Atomic, Molecular & Chemical; Physics, Nuclear SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 103WA UT WOS:000074979800043 ER PT J AU Tung, YS Ueda, A Mu, R Wu, M Chen, J Gu, Z Henderson, DO Collins, WE White, CW Zhur, R AF Tung, YS Ueda, A Mu, R Wu, M Chen, J Gu, Z Henderson, DO Collins, WE White, CW Zhur, R TI Annealing behavior of tin implanted silica SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS LA English DT Article; Proceedings Paper CT 9th International Conference on Radiation Effects in Insulators (REI-9) CY SEP 14-19, 1997 CL KNOXVILLE, TENNESSEE SP Ctr Mat Proc at Univ TN, Pacific NW Natl Lab DE ion implantation; infrared spectroscopy; Kramers-Kronig transformation ID SEQUENTIAL ION-IMPLANTATION; ATOMIC-FORCE MICROSCOPY; SPECTRA AB Tin ions were implanted into silica substrates at 275 keV. The samples were annealed at 300-1000 degrees C. The as-implanted and annealed samples were studied by the infrared specular reflectance technique. Kramers-Kronig transformation (KKT) was carried out on the reflectance spectra to obtain n, k, transverse optical (TO), and longitudinal optical (LO) spectra. Based on these spectra, we can understand the effects of ion implantation and annealing on the Si-O-Si bond angle, Si-O-Si bond breaking, and density change of implanted silica. (C) 1998 Published by Elsevier Science B.V. All rights reserved. C1 Fisk Univ, Dept Phys, Phys Chem Lab, Nashville, TN 37208 USA. Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Henderson, DO (reprint author), Fisk Univ, Dept Phys, Phys Chem Lab, 1000 17th Ave N, Nashville, TN 37208 USA. NR 12 TC 5 Z9 5 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 MAY PY 1998 VL 141 IS 1-4 BP 279 EP 283 DI 10.1016/S0168-583X(98)00137-2 PG 5 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Atomic, Molecular & Chemical; Physics, Nuclear SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 103WA UT WOS:000074979800045 ER PT J AU Henderson, DO Wu, M Ueda, A Tung, YS Mu, R Chen, JT Gu, Z Collins, WE White, CW Budai, J Meldrum, A Zuhr, RA Zhu, JG AF Henderson, DO Wu, M Ueda, A Tung, YS Mu, R Chen, JT Gu, Z Collins, WE White, CW Budai, J Meldrum, A Zuhr, RA Zhu, JG TI Selenium nanoparticles formed by ion implantation into fused silica SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS LA English DT Article; Proceedings Paper CT 9th International Conference on Radiation Effects in Insulators (REI-9) CY SEP 14-19, 1997 CL KNOXVILLE, TENNESSEE SP Ctr Mat Proc at Univ TN, Pacific NW Natl Lab DE selenium; quantum dot; ion implantation ID NANOCRYSTALS AB Selenium ions were implanted into fused silica hosts at an energy of 330 keV at fluences of 1 x 10(16), 3 x 10(16), 6 x 10(16) and 1 x 10(17) ions/cm(2). The samples containing 1 x 10(17) ions/cm(2) were annealed at 600, 800 and 1000 degrees C for 1 h in a 5% H-2 + 95% Ar atmosphere. The electronic spectra of the as-implanted sample exhibited an absorption edge near 2.5 eV (550 nm) as compared to 1.95 for bulk trigonal or amorphous selenium. The absorption edge is shifted to the red as the samples were annealed at increasing temperatures. Infrared reflection measurements revealed a decrease in the reflectivity of a peak associated with the LO mode silica and is attributed to ion beam damage. A new peak was also observed near 1050 cm(-1) for the as-implanted sample and is assigned to an Si-O-dangling bond vibration formed during ion implantation. This peak vanishes when the samples are annealed at 1000 degrees C indicating that the Si-O-Si linkages have reformed. A redshift of the absorption edge that increases with ion dose and annealing temperature observed in the electronic spectra is attributed to quantum confinement of the photo-generated exciton. This observation is consistent with current models predicting quantum size effects in semiconductor nanocrystals. (C) 1998 Published by Elsevier Science B.V. All rights reserved. C1 Fisk Univ, Phys Chem Lab, Dept Phys, Nashville, TN 37208 USA. Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. New Mexico State Univ, Dept Phys, Las Cruces, NM 88003 USA. RP Henderson, DO (reprint author), Fisk Univ, Phys Chem Lab, Dept Phys, Nashville, TN 37208 USA. OI Budai, John/0000-0002-7444-1306 NR 13 TC 8 Z9 8 U1 0 U2 4 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-583X J9 NUCL INSTRUM METH B JI Nucl. Instrum. Methods Phys. Res. Sect. B-Beam Interact. Mater. Atoms PD MAY PY 1998 VL 141 IS 1-4 BP 284 EP 288 DI 10.1016/S0168-583X(98)00135-9 PG 5 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Atomic, Molecular & Chemical; Physics, Nuclear SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 103WA UT WOS:000074979800046 ER PT J AU Ila, D Williams, EK Sarkisov, S Smith, CC Poker, DB Hensley, DK AF Ila, D Williams, EK Sarkisov, S Smith, CC Poker, DB Hensley, DK TI Formation of metallic nanoclusters in silica by ion implantation SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS LA English DT Article; Proceedings Paper CT 9th International Conference on Radiation Effects in Insulators (REI-9) CY SEP 14-19, 1997 CL KNOXVILLE, TENNESSEE SP Ctr Mat Proc at Univ TN, Pacific NW Natl Lab DE ion implantation; metal colloids; nanocrystals; nanoparticles ID OPTICAL-PROPERTIES; GLASS AB We have changed both linear and nonlinear optical properties of suprasil-1 by implanting 2.0 MeV copper, 350 keV tin, 1.5 MeV silver and 3.0 MeV gold. These changes were induced both by over implantation above the threshold fluence for spontaneous cluster formation and by subsequent thermal annealing, and are due to an increase in resonance optical absorption as well as an enhancement of the nonlinear optical properties. Using optical absorption spectrophotometry and Rutherford Backscattering Spectrometry, we have measured the cluster size for each heat treatment temperature. Using Z-scan technique we have determined the third order electric susceptibility for each implanted species to be 1.5 x 10(-6) esu for Sn nanoclusters, 2.7 x 10(-6) esu for Cu nanoclusters, 5 x 10(-)7 esu for Ag nanoclusters, to 6.5 x 10(-7) esu for Au nanoclusters in suprasil-1. (C) 1998 Elsevier Science B.V. All rights reserved. C1 Alabama A&M Univ, Ctr Irradiat Mat, Normal, AL 35762 USA. NASA, MSFC, Marshall Space Flight Ct, AL 35898 USA. Oak Ridge Natl Lab, Div Solid State, Oak Ridge, TN USA. RP Ila, D (reprint author), Alabama A&M Univ, Ctr Irradiat Mat, Normal, AL 35762 USA. EM ila@cim.aamu.edu RI Hensley, Dale/A-6282-2016 OI Hensley, Dale/0000-0001-8763-7765 NR 16 TC 73 Z9 74 U1 1 U2 11 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 MAY PY 1998 VL 141 IS 1-4 BP 289 EP 293 DI 10.1016/S0168-583X(98)00072-X PG 5 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Atomic, Molecular & Chemical; Physics, Nuclear SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 103WA UT WOS:000074979800047 ER PT J AU Sarkisov, SS Williams, E Curley, M Ila, D Venkateswarlu, P Poker, DB Hensley, DK AF Sarkisov, SS Williams, E Curley, M Ila, D Venkateswarlu, P Poker, DB Hensley, DK TI Third order optical nonlinearity of colloidal metal nanoclusters formed by MeV ion implantation SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS LA English DT Article; Proceedings Paper CT 9th International Conference on Radiation Effects in Insulators (REI-9) CY SEP 14-19, 1997 CL KNOXVILLE, TENNESSEE SP Ctr Mat Proc at Univ TN, Pacific NW Natl Lab DE ion implantation; metal nanocluster colloids; nonlinear refractive index; Z-scan ID SILICA AB We report the results of characterization of nonlinear refractive index of the composite material produced by MeV Ag ion implantation of LiNbO3 crystal (z-cut). The material after implantation exhibited a linear optical obsroption spectrum with the surface plasmon peak near 430 nm attributed to the colloidal silver nanoclusters. Heat treatment of the material at 500 degrees C caused a shift of the absorption peak to 550 nm. The nonlinear refractive index of the sample after heat treatment was measured in the region of the absorption peak with the Z-scan technique using a tunable picosecond laser source (4.5 ps pulse width). The experimental data were compared against the reference sample made of MeV Cu implanted silica with the absorption peak in the same region. The nonlinear index of the Ag implanted LiNbO3 sample produced at five times less fluence is on average two times greater than that of the reference. (C) 1998 Elsevier Science B.V. All rights reserved. C1 Alabama A&M Univ, Ctr Irradiat Mat, Dept Nat & Phys Sci Phys, Normal, AL 35762 USA. Oak Ridge Natl Lab, Div Solid State, Oak Ridge, TN 37831 USA. RP Sarkisov, SS (reprint author), Alabama A&M Univ, Ctr Irradiat Mat, Dept Nat & Phys Sci Phys, POB 1447, Normal, AL 35762 USA. RI Hensley, Dale/A-6282-2016 OI Hensley, Dale/0000-0001-8763-7765 NR 19 TC 27 Z9 28 U1 2 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 MAY PY 1998 VL 141 IS 1-4 BP 294 EP 298 DI 10.1016/S0168-583X(98)00017-2 PG 5 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Atomic, Molecular & Chemical; Physics, Nuclear SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 103WA UT WOS:000074979800048 ER PT J AU Zimmerman, RL Ila, D Williams, EK Sarkisov, S Poker, DB Hensley, DK AF Zimmerman, RL Ila, D Williams, EK Sarkisov, S Poker, DB Hensley, DK TI Fabrication of copper and gold nanoclusters in MgO (100) by MeV ion implantation SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS LA English DT Article; Proceedings Paper CT 9th International Conference on Radiation Effects in Insulators (REI-9) CY SEP 14-19, 1997 CL KNOXVILLE, TENNESSEE SP Ctr Mat Proc at Univ TN, Pacific NW Natl Lab DE nanoclusters; ion implantation; metal nanoclusters AB MeV ions of Au and Cu were implanted into single crystals of MgO (100) and the formation of metallic nanoclusters was observed by an indirect method of optical absorption spectrophotometry, Using Mie's theory we related the observed optical absorption band to the formation of nanoclusters and using Doyle's theory, as well as Rutherford Backscattering Spectrometry (RBS), we correlated the full width half maximum (FWHM) of the absorption bands to the estimated size of the metallic nanoclusters between 1 and 10 nm. These clusters were formed by implantation above the threshold fluence for cluster formation and by a combination of threshold fluence of the implanted species and thermal annealing. The changes in the estimated size of the nanoclusters, after annealing at temperatures ranging from 500 degrees C to 1000 degrees C, were observed using optical absorption spectrophotometry and calculated using Doyle's theory. (C) 1998 Elsevier Science B.V. All rights reserved. C1 Alabama A&M Univ, Dept Nat & Phys Sci, Ctr Irradiat Mat, Normal, AL 35762 USA. Oak Ridge Natl Lab, Div Solid State, Oak Ridge, TN 37831 USA. RP Ila, D (reprint author), Alabama A&M Univ, Dept Nat & Phys Sci, Ctr Irradiat Mat, POB 1447, Normal, AL 35762 USA. RI Hensley, Dale/A-6282-2016 OI Hensley, Dale/0000-0001-8763-7765 NR 11 TC 29 Z9 31 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 MAY PY 1998 VL 141 IS 1-4 BP 308 EP 311 DI 10.1016/S0168-583X(98)00019-6 PG 4 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Atomic, Molecular & Chemical; Physics, Nuclear SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 103WA UT WOS:000074979800051 ER PT J AU Meldrum, A Boatner, LA Ewing, RC AF Meldrum, A Boatner, LA Ewing, RC TI Effects of ionizing and displacive irradiation on several perovskite-structure oxides SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS LA English DT Article; Proceedings Paper CT 9th International Conference on Radiation Effects in Insulators (REI-9) CY SEP 14-19, 1997 CL KNOXVILLE, TENNESSEE SP Ctr Mat Proc at Univ TN, Pacific NW Natl Lab DE irradiation; amorphization; perovskite; CaTiO3; domain boundaries ID INDUCED AMORPHIZATION; CERAMIC INSULATORS; CRYSTALS; DOMAINS; BATIO3 AB Synthetic single crystals of CaTiO3, SrTiO3, BaTiO3, KNbO3, and KTaO3 were irradiated by 800 keV Kr+ ions over a range of temperature from 20 to 900 K. The dose required for amorphization was monitored by selected-area electron diffraction. All of the compounds were found to become amorphous over the temperature range investigated, although a significant variation was observed in the critical amorphization temperature, i.e., the temperature above which amorphization was not induced. This variation is related to chemical differences through a combination of factors, including bonding variations and the ratio of electronic-to-nuclear energy loss. Some of the perovskite-structure compounds undergo one or more instantaneous displacive phase transitions; however, these structural changes were not found to significantly affect the amorphization dose in these experiments. (C) 1998 Published by Elsevier Science B.V. All rights reserved. C1 Oak Ridge Natl Lab, Div Solid State, Oak Ridge, TN 37831 USA. Univ Michigan, Dept Nucl Engn & Radiol Sci, Ann Arbor, MI 48109 USA. RP Meldrum, A (reprint author), Oak Ridge Natl Lab, Div Solid State, MS-6057, Oak Ridge, TN 37831 USA. RI Boatner, Lynn/I-6428-2013 OI Boatner, Lynn/0000-0002-0235-7594 NR 26 TC 43 Z9 43 U1 3 U2 10 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 MAY PY 1998 VL 141 IS 1-4 BP 347 EP 352 DI 10.1016/S0168-583X(98)00075-5 PG 6 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Atomic, Molecular & Chemical; Physics, Nuclear SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 103WA UT WOS:000074979800057 ER PT J AU Sickafus, KE Matzke, H Yasuda, K Chodak, P Verrall, RA Lucuta, PG Andrews, HR Turos, A Fromknecht, R Baker, NP AF Sickafus, KE Matzke, H Yasuda, K Chodak, P Verrall, RA Lucuta, PG Andrews, HR Turos, A Fromknecht, R Baker, NP TI Radiation damage effects in cubic-stabilized zirconia irradiated with 72 MeV I+ ions SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS LA English DT Article; Proceedings Paper CT 9th International Conference on Radiation Effects in Insulators (REI-9) CY SEP 14-19, 1997 CL KNOXVILLE, TENNESSEE SP Ctr Mat Proc at Univ TN, Pacific NW Natl Lab DE radiation damage; amorphization; zirconia ID FUEL; UO2 AB Cubic-stabilized zirconia single crystals were irradiated using 72 MeV I+ ions in the TASSC accelerator facility at Chalk River Laboratory (to simulate a typical U or Pu fission fragment). Irradiations were performed over the fluence range 1 x 10(18) -5 x 10(19) ions/m(2), at temperatures of 300, 770, and 1170 K. Damage accumulation was monitored using Rutherford Backscattering Spectroscopy and ion-channeling (RBS/C) techniques. At ambient temperature and at the highest I-divided by fluence used in these experiments (5 x 10(19) I+/m(2)), RBS/C measurements revealed a rather high degree of lattice disorder. Specifically, the dechanneling parameter chi(min) varied from 80% to greater than 90% over the depth probed by RBS/C (similar to l mu m). Nano-indentation measurements on the same sample indicated decreases in elastic modulus, E, and hardness, H (both by about 9%). These results suggest that an alteration in structure beyond simple defect accumulation occurs under these irradiation conditions. However, transmission electronmicroscopy (TEM) observations and in particular microdiffraction measurements failed to reveal any structural transformations in the irradiated material. (C) 1998 Elsevier Science B.V. All rights reserved. C1 Univ Calif Los Alamos Natl Lab, Mat Sci & Techn Div, Los Alamos, NM 87545 USA. European Commiss JRC, Inst Transuranium Elements, Karlsruhe, Germany. Kyushu Univ, Fukuoka 812, Japan. AECL Res, Chalk River Labs, Chalk River, ON K0J 1J0, Canada. Soltan Inst Nucl Studies, PL-00681 Warsaw, Poland. Forschungszentrum Karlsruhe, INFP, D-76021 Karlsruhe, Germany. RP Sickafus, KE (reprint author), Univ Calif Los Alamos Natl Lab, Mat Sci & Techn Div, POB 1663, Los Alamos, NM 87545 USA. NR 17 TC 70 Z9 70 U1 1 U2 12 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 MAY PY 1998 VL 141 IS 1-4 BP 358 EP 365 DI 10.1016/S0168-583X(98)00217-1 PG 8 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Atomic, Molecular & Chemical; Physics, Nuclear SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 103WA UT WOS:000074979800059 ER PT J AU Devanathan, R Weber, WJ Sickafus, KE Nastasi, M Wang, LM Wang, SX AF Devanathan, R Weber, WJ Sickafus, KE Nastasi, M Wang, LM Wang, SX TI Cryogenic radiation response of sapphire SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS LA English DT Article; Proceedings Paper CT 9th International Conference on Radiation Effects in Insulators (REI-9) CY SEP 14-19, 1997 CL KNOXVILLE, TN SP Ctr Mat Proc at Univ TN, Pacific NW Natl Lab DE amorphization; ion irradiation; electron irradiation; ionization-enhanced diffusion; in situ microscopy ID DIFFUSION AB We have studied the response of sapphire (alpha-Al2O3) to heavy-ion and electron irradiation at cryogenic temperatures using a high-voltage electron microscope. The structural changes were determined in situ during irradiation with 1.5 MeV Xe+, 1 MeV Kr+, and a dual beam of 1 MeV Kr+ and 900 keV electrons at temperatures from 20 to 100 K. At 20 K, alpha-alumina is amorphized by 1.5 MeV Xe+ at about 3.8 displacements per atom (dpa). The critical temperature for this amorphization was determined to be about 170 K, However, the material remains crystalline when irradiated at 26 K with a dual beam of heavy ions and electrons. The results demonstrate that electron irradiation can promote damage annealing, even at cryogenic temperatures, by causing the migration of point-defects produced in ceramics by ion irradiation. Published by Elsevier Science B.V. C1 Pacific NW Lab, Richland, WA 99352 USA. Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Univ Michigan, Ann Arbor, MI 48109 USA. RP Pacific NW Lab, POB 999,MS K1-96,Battelle Blvd, Richland, WA 99352 USA. EM ram@pnl.gov RI Weber, William/A-4177-2008; Devanathan, Ram/C-7247-2008 OI Weber, William/0000-0002-9017-7365; Devanathan, Ram/0000-0001-8125-4237 NR 18 TC 15 Z9 15 U1 0 U2 11 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-583X EI 1872-9584 J9 NUCL INSTRUM METH B JI Nucl. Instrum. Methods Phys. Res. Sect. B-Beam Interact. Mater. Atoms PD MAY PY 1998 VL 141 IS 1-4 BP 366 EP 371 DI 10.1016/S0168-583X(98)00190-6 PG 6 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Atomic, Molecular & Chemical; Physics, Nuclear SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 103WA UT WOS:000074979800060 ER PT J AU Hartmann, T Wang, LM Weber, WJ Yu, N Sickafus, KE Mitchell, JN Wetteland, CJ Nastasi, MA Hollander, MG Baker, NP Evans, CR Tesmer, JR Maggiore, CJ AF Hartmann, T Wang, LM Weber, WJ Yu, N Sickafus, KE Mitchell, JN Wetteland, CJ Nastasi, MA Hollander, MG Baker, NP Evans, CR Tesmer, JR Maggiore, CJ TI Ion beam radiation damage effects in rutile (TiO2) SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS LA English DT Article; Proceedings Paper CT 9th International Conference on Radiation Effects in Insulators (REI-9) CY SEP 14-19, 1997 CL KNOXVILLE, TENNESSEE SP Ctr Mat Proc at Univ TN, Pacific NW Natl Lab DE TiO2 rutile; radiation damage; noble gas ion implantation ID IRRADIATION; ZIRCONOLITE AB Radiation damage accumulation in the rutile phase of titanium dioxide (TiO2) have been studied by Rutherford Backscattering Spectroscopy in channeling geometry (RBS/c) and by transmission electron microscopy (TEM). A large temperature dependence of damage accumulation in rutile was observed. Defect accumulation determined in situ by RBS/c occurs far more rapidly in samples irradiated at 160 K compared to 300 K, A rutile single crystal irradiated at 160 K was rendered fully amorphous at a fluence of 4 x 10(18) Xe2+/m(2), compared to a critical amorphization fluence of 8 x 10(19) Xe2+/m(2) for a crystal irradiated at 300 K. In samples irradiated at 300 K a defect denuded zone at the crystal surface was observed to accompany a buried damage layer. In samples irradiated at 160 K, no defect denuded zone was observed. These observations indicate that there is a large temperature dependence associated with thermally activated point defect mobility in rutile. Moreover, in in situ irradiation experiments using 1.5 MeV Xe+ ions, a critical amorphization temperature of 200 K was observed. The rutile structure is much more susceptible to radiation damage induced by point defect accumulation, compared to dense collision cascades. In the experiments presented here, only the He+ ion irradiation leads to complete amorphization, combined with substantial changes in the micro-hardness and elastic (Young's) modulus. (C) 1998 Elsevier Science B.V. All rights reserved. C1 Los Alamos Natl Lab, Div Mat Sci & Technol, Los Alamos, NM 87545 USA. Univ Michigan, Ann Arbor, MI 48109 USA. Pacific NW Lab, Richland, WA 99352 USA. Texas Instruments Inc, Dallas, TX USA. RP Hartmann, T (reprint author), Los Alamos Natl Lab, Div Mat Sci & Technol, Los Alamos, NM 87545 USA. RI Weber, William/A-4177-2008; Mitchell, Jeremy/E-2875-2010 OI Weber, William/0000-0002-9017-7365; Mitchell, Jeremy/0000-0001-7109-3505 NR 10 TC 25 Z9 25 U1 2 U2 14 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 MAY PY 1998 VL 141 IS 1-4 BP 398 EP 403 DI 10.1016/S0168-583X(98)00134-7 PG 6 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Atomic, Molecular & Chemical; Physics, Nuclear SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 103WA UT WOS:000074979800067 ER PT J AU Mitchell, JN Devanathan, R Yu, N Sickafus, KE Wetteland, CJ Gopalan, V Nastasi, MA McClellan, KJ AF Mitchell, JN Devanathan, R Yu, N Sickafus, KE Wetteland, CJ Gopalan, V Nastasi, MA McClellan, KJ TI Radiation effects in corundum structure derivatives SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS LA English DT Article; Proceedings Paper CT 9th International Conference on Radiation Effects in Insulators (REI-9) CY SEP 14-19, 1997 CL KNOXVILLE, TENNESSEE SP Ctr Mat Proc at Univ TN, Pacific NW Natl Lab DE radiation damage; amorphization; corundum structure; rhombohedral oxides ID AMORPHIZATION; IRRADIATION; DAMAGE AB The radiation response of alpha-Al2O3 (R (3) over bar c), FeTiO3 (R (3) over bar), MgTiO3 (R (3) over bar), and LiTaO3 (R (3) over bar c) was investigated using 200 keV Ar2+ and 1 MeV Kr+ and a combination of Rutherford backscattering spectrometry and transmission electron microscopy. All of these materials have the corundum or a corundum-derivative crystal structure. This family of oxides is of interest due to the simple but significant differences in the structure of the cation sublattices in the different space groups. These materials are also of interest because of their range of melting temperatures, the range of melting temperatures of their oxide components, differences in bonding characteristics, and the complete solid solution between FeTiO3 and MgTiO3. Our results show that alpha-Al2O3 and MgTiO3 are consistently more radiation tolerant than FeTiO3 and that LiTaO3 amorphizes substantially easier than the other three oxides. The greater stability of MgTiO3 than FeTiO3 appears to be analogous to the response of Mg-Fe silicates to ion irradiation and high pressure. A characteristic consistent with the radiation tolerance trend of the four oxides studied is a decreasing melting temperature of the component oxides. Thus, the lower stability of Fe-O octahedra in FeTiO3 and Li-O octahedra in LiTaO3 may adversely affect the radiation tolerance of these oxides. (C) 1998 Elsevier Science B.V. All rights reserved. C1 Los Alamos Natl Lab, Div Mat Sci & Technol, Los Alamos, NM 87545 USA. Pacific NW Lab, Richland, WA 99352 USA. Texas Instruments Inc, Dallas, TX 75243 USA. RP Mitchell, JN (reprint author), Los Alamos Natl Lab, Div Mat Sci & Technol, Mail Stop K762, Los Alamos, NM 87545 USA. RI Devanathan, Ram/C-7247-2008 OI Devanathan, Ram/0000-0001-8125-4237 NR 12 TC 7 Z9 7 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 MAY PY 1998 VL 141 IS 1-4 BP 461 EP 466 DI 10.1016/S0168-583X(98)00141-4 PG 6 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Atomic, Molecular & Chemical; Physics, Nuclear SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 103WA UT WOS:000074979800078 ER PT J AU Magruder, RH Weeks, RA Zuhr, RA Hensley, DK AF Magruder, RH Weeks, RA Zuhr, RA Hensley, DK TI Optical absorption and photosensitivity of N implanted silica SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS LA English DT Article; Proceedings Paper CT 9th International Conference on Radiation Effects in Insulators (REI-9) CY SEP 14-19, 1997 CL KNOXVILLE, TENNESSEE SP Ctr Mat Proc at Univ TN, Pacific NW Natl Lab DE optical absorption; ion implantation; silica ID ION-IMPLANTATION AB Silica was implanted with N ions at 4 MeV with nominal doses of 0.1, 0.3, 1.0 and 3.0 x 10(16) ions/cm(2). Optical absorption, measured from 2.5 to 6.2 eV, had maxima at 5.0 and 5.9 eV whose amplitudes increased with increasing dose. The ratio of the maximum amplitudes of these two bands was invariant with dose. The sample implanted with 1 x 10(16) ions/cm(2) was exposed to 5 eV KrF excimer photons, 150 mJ/cm(2) per 20 ns pulse for totals of 1.5, 15 and 30 J/cm(2). Absorption decreased at 5.0, 5.9 and 6.2 eV for all exposures. The decrease in absorption revealed a band at similar to 4.7 eV that did not bleach, Thes data are compared to similar data of B implanted silica and based on comparison effects specific to N and B are resolved, These differences are attributed to interactions of N with Si and B with O. (C) 1998 Published by Elsevier Science B.V. All rights reserved. C1 Belmont Univ, Dept Phys, Nashville, TN 37212 USA. Vanderbilt Univ, Dept Mech Engn, Nashville, TN 37235 USA. Oak Ridge Natl Lab, Div Solid State, Oak Ridge, TN 37831 USA. RP Magruder, RH (reprint author), Belmont Univ, Dept Phys, Nashville, TN 37212 USA. RI Hensley, Dale/A-6282-2016 OI Hensley, Dale/0000-0001-8763-7765 NR 15 TC 1 Z9 1 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-583X J9 NUCL INSTRUM METH B JI Nucl. Instrum. Methods Phys. Res. Sect. B-Beam Interact. Mater. Atoms PD MAY PY 1998 VL 141 IS 1-4 BP 575 EP 579 DI 10.1016/S0168-583X(98)00100-1 PG 5 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Atomic, Molecular & Chemical; Physics, Nuclear SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 103WA UT WOS:000074979800100 ER PT J AU Darwish, A Ila, D Poker, DB Hensley, DK AF Darwish, A Ila, D Poker, DB Hensley, DK TI Investigation of Mn implanted LiNbO3 applying electron paramagnetic resonance SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS LA English DT Article; Proceedings Paper CT 9th International Conference on Radiation Effects in Insulators (REI-9) CY SEP 14-19, 1997 CL KNOXVILLE, TENNESSEE SP Ctr Mat Proc at Univ TN, Pacific NW Natl Lab DE ion implantation; photorefractive crystal; EPR; transition metal ions; spin concentration; laser illumination AB The effect of ion implantation on LiNbO3 crystal is studied using electron paramagnetic resonance spectroscopy (EPR). EPR measurements on these crystals were performed as a function of ion species Mn and Fe and fluence at room temperature, Also the effect of the laser illumination on the EPR signal was determined by illuminating the crystal in situ and measuring the decay and growth of the EPR signal. LiNbO3:Mn2+ at a depth of approximately 200 nm was formed by implantation of 2.5 x 10(14) and 1 x 10(17) Mn/cm(2) at 2 MeV. The implanted samples were compared with bulk doped crystals. It was found that the decay and growth of Mn EPR for the implanted crystal is very small compared with the bulk doped LiNbO3:Mn crystal. This was found to be primarily due to the spin concentration on the crystals. On the other hand, the decay time of the high fluence is about 40% slower than the decay of the low fluence implanted crystal. (C) 1998 Elsevier Science B.V. All rights reserved. C1 Alabama A&M Univ, Dept Nat & Phys Sci, Ctr Irradiat Mat, Normal, AL 35762 USA. Oak Ridge Natl Lab, Div Solid State, Oak Ridge, TN 37831 USA. Ctr Nonlinear Opt & Mat, Laser Matter Res Lab, Normal, AL 35762 USA. RP Ila, D (reprint author), Alabama A&M Univ, Dept Nat & Phys Sci, Ctr Irradiat Mat, Normal, AL 35762 USA. RI Hensley, Dale/A-6282-2016 OI Hensley, Dale/0000-0001-8763-7765 NR 8 TC 6 Z9 6 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 MAY PY 1998 VL 141 IS 1-4 BP 679 EP 683 DI 10.1016/S0168-583X(98)00147-5 PG 5 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Atomic, Molecular & Chemical; Physics, Nuclear SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 103WA UT WOS:000074979800117 ER PT J AU Taylor, T Ila, D Zimmerman, RL Cochrane, JC Ashley, PR Poker, DB Hensley, DK AF Taylor, T Ila, D Zimmerman, RL Cochrane, JC Ashley, PR Poker, DB Hensley, DK TI Temperature effects on the fabrication of optical channels in planar GaAs/AlGaAs waveguides using MeV ions SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS LA English DT Article; Proceedings Paper CT 9th International Conference on Radiation Effects in Insulators (REI-9) CY SEP 14-19, 1997 CL KNOXVILLE, TENNESSEE SP Ctr Mat Proc at Univ TN, Pacific NW Natl Lab DE ion implantation; GaAs/AlGaAs; optical waveguides ID WAVE-GUIDES; DISORDER AB We have fabricated optical channels in selectively masked planar GaAs/AlGaAs waveguide structures using both 10 MeV oxygen and 8 MeV carbon ions. Implantation at different temperatures appears to have a direct effect on the extracted propagation mode losses. Single-mode operation was observed from all the fabricated optical channels at a wavelength of 1.3 mu m. The optical characterization results provide insight as to which ion beam parameters are best suited to optimize this fabrication process. (C) 1998 Elsevier Science B.V. All rights reserved. C1 Alabama A&M Univ, Dept Nat & Phys Sci, Ctr Irradiat Mat, Normal, AL 35762 USA. USA, Missile Command, Ctr Res Dev & Engn, Weap Sci Directorate, Redstone Arsenal, AL 35898 USA. Oak Ridge Natl Lab, Div Solid State, Oak Ridge, TN 37831 USA. RP Ila, D (reprint author), Alabama A&M Univ, Dept Nat & Phys Sci, Ctr Irradiat Mat, POB 1447, Normal, AL 35762 USA. RI Hensley, Dale/A-6282-2016 OI Hensley, Dale/0000-0001-8763-7765 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 MAY PY 1998 VL 141 IS 1-4 BP 704 EP 708 DI 10.1016/S0168-583X(98)00119-0 PG 5 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Atomic, Molecular & Chemical; Physics, Nuclear SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 103WA UT WOS:000074979800121 ER PT J AU Zinkle, SJ Skuratov, VA AF Zinkle, SJ Skuratov, VA TI Track formation and dislocation loop interaction in spinel irradiated with swift heavy ions SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS LA English DT Article; Proceedings Paper CT 9th International Conference on Radiation Effects in Insulators (REI-9) CY SEP 14-19, 1997 CL KNOXVILLE, TN SP Ctr Mat Proc at Univ TN, Pacific NW Natl Lab DE heavy ion irradiation; spinel; dislocation loops; track formation ID ELECTRONIC STOPPING-POWER; CERAMIC INSULATORS; DAMAGE; OXIDES; BEAM; MICROSTRUCTURE; SAPPHIRE; DISORDER; REGIME; MODEL AB The microstructure of polycrystalline stoichiometric magnesium aluminate spinel (MgAl2O4) has been examined by cross-section electron microscopy following 430 MeV Kr+ or 614 MeV Xe+ ion irradiation near room temperature up to a fluence of 1.1 x 10(16) ions/m(2). In addition, the microstructure was examined for two spinel specimens which had been preirradiated with either 2 MeV Al+ ions or 3.6 MeV Fe+ ions and subsequently irradiated with 430 MeV Kr+ ions. The Al+ and Fe+ preirradiated specimens contained a high density (10(21)-10(23) m(-3)) of interstitial dislocation loops with diameters between 5 and 30 nm prior to the swift heavy ion irradiation. Near-continuous latent ion tracks were observed in all of the specimens irradiated with swift heavy ions. The swift heavy ions also appeared to efficiently destroy pre-existing dislocation loops with diameters <5 nm, whereas larger loops remained intact following the swift heavy ion irradiation. The swift heavy ions caused structural disordering of the octahedral cautions, but did not appear to produce amorphous cores in the ion tracks, The disordered ion track diameters were similar to 2.0 and similar to 2.6 nm for the 430 MeV Kr and 614 MeV Xe ion irradiations, respectively. (C) 1998 Published by Elsevier Science B.V. All rights reserved. C1 Oak Ridge Natl Lab, Div Met & Ceram, Oak Ridge, TN 37831 USA. Joint Inst Nucl Res, Dubna 141980, Russia. RP Oak Ridge Natl Lab, Div Met & Ceram, POB 2008, Oak Ridge, TN 37831 USA. EM zinklesj@ornl.gov OI Zinkle, Steven/0000-0003-2890-6915 NR 39 TC 35 Z9 35 U1 2 U2 13 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-583X EI 1872-9584 J9 NUCL INSTRUM METH B JI Nucl. Instrum. Methods Phys. Res. Sect. B-Beam Interact. Mater. Atoms PD MAY PY 1998 VL 141 IS 1-4 BP 737 EP 746 DI 10.1016/S0168-583X(98)00078-0 PG 10 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Atomic, Molecular & Chemical; Physics, Nuclear SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 103WA UT WOS:000074979800126 ER PT J AU Contogouris, AP Zielinski, M Artru, X Schuler, G Ochs, W AF Contogouris, AP Zielinski, M Artru, X Schuler, G Ochs, W TI Parton k(T) and large-p(T) production of direct photons and pi(0) mesons - Discussions SO NUCLEAR PHYSICS B-PROCEEDINGS SUPPLEMENTS LA English DT Editorial Material C1 Univ Athens, GR-15771 Athens, Greece. Fermi Natl Accelerator Lab, Batavia, IL 60510 USA. LPC, IN2P3, CNRS, F-63177 Aubiere, France. CERN, TH, CH-1211 Geneva 23, Switzerland. Max Planck Inst Phys, D-80805 Munich, Germany. RP Contogouris, AP (reprint author), Univ Athens, GR-15771 Athens, Greece. NR 0 TC 0 Z9 0 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0920-5632 J9 NUCL PHYS B-PROC SUP JI Nucl. Phys. B-Proc. Suppl. PD MAY PY 1998 VL 64 BP 88 EP 89 PG 2 WC Physics, Particles & Fields SC Physics GA ZG231 UT WOS:000072980300024 ER PT J AU Hanlet, P Alexopoulos, T AF Hanlet, P Alexopoulos, T TI CP violation and rare kaon/hyperon decays at KTeV experiment - Discussions SO NUCLEAR PHYSICS B-PROCEEDINGS SUPPLEMENTS LA English DT Editorial Material C1 Fermi Natl Accelerator Lab, Batavia, IL 60510 USA. RP Hanlet, P (reprint author), Fermi Natl Accelerator Lab, POB 500,MS 352, Batavia, IL 60510 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0920-5632 J9 NUCL PHYS B-PROC SUP JI Nucl. Phys. B-Proc. Suppl. PD MAY PY 1998 VL 64 BP 287 EP 287 PG 1 WC Physics, Particles & Fields SC Physics GA ZG231 UT WOS:000072980300077 ER PT J AU Plano, R AF Plano, R TI Properties of the b(b)over-bar-g vertex SO NUCLEAR PHYSICS B-PROCEEDINGS SUPPLEMENTS LA English DT Article; Proceedings Paper CT 5th Montpellier Conference on Quantum Chromodynamics (QCD 97) CY JUL 03-09, 1997 CL PALAIS CONGRES CORUM MONTPELLIER, MONTPELLIER, FRANCE SP European Commiss, Brussels HO PALAIS CONGRES CORUM MONTPELLIER ID SLD AB We have used the unique strengths of the SLAG Linear Collider (SLC) and the SLD detector to study some important properties of the b(b) over barg$ vertex. Using the excellent impact parameter resolution to identify and tag jets produced by Light quarks, by charmed quarks, or by bottom quarks, we have measured the lack of dependence of the strong coupling alpha(s) on quark flavor to within 1.6% (uds), 7.9% (c), and 3.1% (b). We have set an upper Limit of less than 7% on an anomalous chromomagnetic coupling at the b(b) over barg$ vertex. Finally we have shown the parity violation and symmetry properties of the b(b) over barg$ vertex agree with QCD calculations to the 10% level. C1 US DOE, Germantown, MD 20874 USA. RP Plano, R (reprint author), US DOE, Germantown, MD 20874 USA. NR 13 TC 0 Z9 0 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0920-5632 J9 NUCL PHYS B-PROC SUP JI Nucl. Phys. B-Proc. Suppl. PD MAY PY 1998 VL 64 BP 392 EP 396 DI 10.1016/S0920-5632(97)01095-5 PG 5 WC Physics, Particles & Fields SC Physics GA ZG231 UT WOS:000072980300106 ER PT J AU Verzilov, YM Ikeda, Y Maekawa, F Oyama, Y Smith, D AF Verzilov, YM Ikeda, Y Maekawa, F Oyama, Y Smith, D TI Measurements of tritium and C-14 production cross sections for 14.7-MeV neutrons on O-17 and O-18 SO NUCLEAR SCIENCE AND ENGINEERING LA English DT Article AB Samples of water isotopically enriched in O-17, O-18, and H-2 along with natural water were bombarded by neutrons from the intense deuterium-tritium source provided by the Fusion Neutron Source facility. After irradiation, the accumulated concentrations of H-3 and C-14 activities were determined by the liquid scintillation method. Special attention was paid to C-14 losses in the gas phase during irradiation and preparation of scintillation counting samples. Cross sections for the O-17(n, alpha)C-14, O-18(n,n'alpha)C-14, O-17(n, t)N-15 and O-18(n,t)N-16 reactions at 14.7 MeV have been measured for the first time. The following values have been obtained for these reactions: 18.0 +/- 3.3, 35.4 +/- 6.5, 0.82 +/- 0.15, and 26.8 +/- 4.9 mb, respectively, relative to the Nb-93(n,2n)Nb-92m standard reaction cross section of 460 mb. A study of the systematics of (n,t) reactions at 14.7 MeV on light nuclei (atomic number Z < 10) has been carried out. The experimental cross-section values are also compared with data in the comprehensive activation libraries. C1 Tokai Res Estab, Japan Atom Energy Res Inst, Dept Reactor Engn, Tokai, Ibaraki 31911, Japan. Argonne Natl Lab, Technol Dev Div, Argonne, IL 60439 USA. RP Ikeda, Y (reprint author), Tokai Res Estab, Japan Atom Energy Res Inst, Dept Reactor Engn, Tokai, Ibaraki 31911, Japan. NR 35 TC 0 Z9 0 U1 0 U2 0 PU AMER NUCLEAR SOCIETY PI LA GRANGE PK PA 555 N KENSINGTON AVENUE, LA GRANGE PK, IL 60525 USA SN 0029-5639 J9 NUCL SCI ENG JI Nucl. Sci. Eng. PD MAY PY 1998 VL 129 IS 1 BP 81 EP 87 PG 7 WC Nuclear Science & Technology SC Nuclear Science & Technology GA ZL373 UT WOS:000073426400006 ER PT J AU Shapira, Y AF Shapira, Y TI Analysis of matrix-dependent multigrid algorithms SO NUMERICAL LINEAR ALGEBRA WITH APPLICATIONS LA English DT Article DE diffusion problem; discontinuous coefficients; indefinite Helmholtz equation; multigrid method ID NONSYMMETRIC LINEAR-SYSTEMS; MINIMAL RESIDUAL ALGORITHM; FINITE-ELEMENT EQUATIONS; BOUNDARY-VALUE-PROBLEMS; RECIRCULATING-FLOWS; COEFFICIENTS; SCHEMES; SOLVER AB Convergence theory for a multigrid method with matrix-dependent restriction, prolongation and coarse-grid operators is developed for a class of SPD problems. It motivates the construction of improved multigrid versions for diffusion problems with discontinuous coefficients. A computational two-level analysis method for a class of separable problems is also available. It motivates the design of matrix-dependent multigrid algorithms and, in particular, multiple coarse-grid correction algorithms for highly indefinite equations. Numerical experiments show the advantage of the present methods for several examples. (C) 1998 John Wiley & Sons, Ltd. C1 Technion Israel Inst Technol, Dept Comp Sci, IL-32000 Haifa, Israel. RP Los Alamos Natl Lab, Mail Stop B-256, Los Alamos, NM 87545 USA. EM yairs@cs.technion.ac.il NR 48 TC 7 Z9 7 U1 0 U2 0 PU WILEY-BLACKWELL PI HOBOKEN PA 111 RIVER ST, HOBOKEN 07030-5774, NJ USA SN 1070-5325 EI 1099-1506 J9 NUMER LINEAR ALGEBR JI Numer. Linear Algebr. Appl. PD MAY-JUN PY 1998 VL 5 IS 3 BP 165 EP 201 PG 37 WC Mathematics, Applied; Mathematics SC Mathematics GA ZV147 UT WOS:000074274200002 ER PT J AU Reich, PB Walters, MB Ellsworth, DS Vose, JM Volin, JC Gresham, C Bowman, WD AF Reich, PB Walters, MB Ellsworth, DS Vose, JM Volin, JC Gresham, C Bowman, WD TI Relationships of leaf dark respiration to leaf nitrogen, specific leaf area and leaf life-span: a test across biomes and functional groups SO OECOLOGIA LA English DT Article DE respiration; leaf life-span; specific leaf area; nitrogen; functional groups ID HARDWOOD SEEDLINGS; SHADE TOLERANCE; USE EFFICIENCY; GROWTH-RATE; LOW-LIGHT; PLANTS; PHOTOSYNTHESIS; ECOSYSTEMS; NUTRIENT; DEFENSE AB Based on prior evidence of coordinated multiple leaf trait scaling, we hypothesized that variation among species in leaf dark respiration rate (R-d) should scale with variation in traits such as leaf nitrogen (N), leaf life-span, specific leaf area (SLA), and net photosynthetic capacity (A(max)). However, it is not known whether such scaling if it exists, is similar among disparate biomes and plant functional types. We tested this idea by examining the interspecific relationships between R-d measured at a standard temperature and leaf life-span, N, SLA and A(max) for 69 species from four functional groups (forbs, broad-leafed trees and shrubs, and needle-leafed conifers) in six biomes traversing the Americas. alpine tundra/subalpine forest, Colorado; cold temperate forest/ grassland, Wisconsin; cool temperate forest, North Carolina; desert/shrubland, New Mexico; subtropical forest, South Carolina; and tropical rain forest, Amazonas, Venezuela. Area-based R-d was positively related to area-based leaf N within functional groups and for all species pooled, but not when comparing among species within any site. At all sites, mass-based R-d (Rd-mass) decreased sharply with increasing leaf life-span and was positively related to SLA and mass-based A(max) and leaf N (leaf N-mass). These intra-biome relationships were similar in shape and slope among sites, where in each case we compared species belonging to different plant functional groups. Significant Rd-mass-N-mass relationships were observed in all functional groups (pooled across sites), but the relationships differed, with higher R-d at any given leaf N in functional groups (such as forbs) with higher SLA and shorter leaf life-span. Regardless of biome or functional group, Rd-mass was well predicted by all combinations of leaf life-span, N-mass and/or SLA (r(2) > 0.79, P < 0.0001). At any given SLA, Rd-mass rises with increasing N-mass and/or decreasing leaf life-span and at any level of N-mass, Rd-mass rises with increasing SLA and/or decreasing leaf life-span. The relationships between R-d and leaf traits observed in this study support the idea of a global set of predictable interrelationships between key leaf morphological, chemical and metabolic traits. C1 Univ Minnesota, Dept Forest Resources, St Paul, MN 55108 USA. Univ No British Columbia, Fac Nat Resources & Envrionm Studies, Prince George, BC V2N 4Z9, Canada. Brookhaven Natl Lab, Dept Appl Sci, Upton, NY 11973 USA. US Forest Serv, Coweeta Hydrol Lab, Otto, NC 28763 USA. Florida Atlantic Univ, Div Sci, Ft Lauderdale, FL 33314 USA. Clemson Univ, Baruch Forest Inst, Georgetown, SC 29442 USA. Univ Colorado, Inst Arctic & Alpine Res, Mt Res Stn, Boulder, CO 80309 USA. Univ Minnesota, Dept EPO Biol, St Paul, MN 55108 USA. RP Univ Minnesota, Dept Forest Resources, St Paul, MN 55108 USA. OI Ellsworth, David/0000-0002-9699-2272 NR 24 TC 285 Z9 354 U1 13 U2 132 PU SPRINGER PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 0029-8549 EI 1432-1939 J9 OECOLOGIA JI Oecologia PD MAY PY 1998 VL 114 IS 4 BP 471 EP 482 DI 10.1007/s004420050471 PG 12 WC Ecology SC Environmental Sciences & Ecology GA ZR339 UT WOS:000073964200004 PM 28307896 ER PT J AU Vikram, CS Pechersky, MJ AF Vikram, CS Pechersky, MJ TI Effect of low-frequency vibrations on speckle interferometry fringes SO OPTICAL ENGINEERING LA English DT Article DE speckle correlation interferometry; vibration; stress analysis; in situ applications; fringe contrast; fringe shift ID PATTERN INTERFEROMETRY; LASER SPECKLE AB The effects of low-frequency vibrations on speckle correlation fringes have been investigated. The relatively short capture time of the camera in the low-frequency case may yield usable fringe contrast in spite of vibration. It has been shown that the fringes also shift due to the vibration. The study is in agreement with experimental observations of good-contrast correlation fringes even if the object is not on a vibration-isolated table. Some such experimental observations are also presented. (C) 1998 Society of Photo-Optical Instrumentation Engineers. [S0091-3286(98)03605-8]. C1 Univ Alabama, Ctr Appl Opt, Huntsville, AL 35899 USA. Westinghouse Savannah River Co, Savannah River Technol Ctr, Aiken, SC 29802 USA. RP Vikram, CS (reprint author), Univ Alabama, Ctr Appl Opt, Huntsville, AL 35899 USA. NR 21 TC 5 Z9 5 U1 0 U2 0 PU SPIE - INTERNATIONAL SOCIETY FOR OPTICAL ENGINEERING PI BELLINGHAM PA POB 10, BELLINGHAM, WA 98227-0010 USA SN 0091-3286 J9 OPT ENG JI Opt. Eng. PD MAY PY 1998 VL 37 IS 5 BP 1602 EP 1607 DI 10.1117/1.601685 PG 6 WC Optics SC Optics GA ZN953 UT WOS:000073700300033 ER PT J AU Sweetser, JN Durant, JL Trebino, R AF Sweetser, JN Durant, JL Trebino, R TI Ultrafast spectroscopy of high-lying excited states via eight-wave mixing SO OPTICS COMMUNICATIONS LA English DT Article ID 4-WAVE-MIXING SPECTROSCOPY; DEGENERATE; FLAME AB We demonstrate the use of eight-wave mixing (8WM) with femtosecond laser pulses for the detection of the high-lying D state of ethylene (C2H4) gas. The D state is reached through three-photon absorption of 427 nm light followed by a delayed single-photon probe interaction with the ionization continuum. resulting in an overall 8WM process. This scheme allows the detection of high-lying states with both spatial and temporal resolution before a thermal grating tan form. Alternatively, by using a nanosecond delay between pulses, the induced thermal grating may be studied after the population grating has decayed. We verify the precise 8WM nature of this process and show how to use it to study the excited-state dynamics of ethylene and to measure the profile of an ethylene flow. (C) 1998 Elsevier Science B.V. All rights reserved. C1 Sandia Natl Labs, Combust Res Facil, Livermore, CA 94551 USA. RP Trebino, R (reprint author), Sandia Natl Labs, Combust Res Facil, MS 9051, Livermore, CA 94551 USA. NR 18 TC 0 Z9 0 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0030-4018 J9 OPT COMMUN JI Opt. Commun. PD MAY 1 PY 1998 VL 150 IS 1-6 BP 180 EP 184 DI 10.1016/S0030-4018(98)00086-8 PG 5 WC Optics SC Optics GA ZY157 UT WOS:000074592000035 ER PT J AU Friedman, LH Chrzan, DC AF Friedman, LH Chrzan, DC TI Continuum analysis of dislocation pile-ups: influence of sources SO PHILOSOPHICAL MAGAZINE A-PHYSICS OF CONDENSED MATTER STRUCTURE DEFECTS AND MECHANICAL PROPERTIES LA English DT Article AB One explanation of the Hall-Fetch relationship is that dislocation pile-ups serve to enhance the stress felt at grain boundaries. This dislocation pile-up model results in a d(-1/2) dependence of the yield strength, with d the grain size. In fact, this dependence is observed often. However, the traditional pile-up picture neglects two important aspects of pile-up formation: firstly the existence of a threshold stress for dislocation production, and secondly the necessity of a finite-sized dislocation-fi-ee region in which a source may operate. In this paper, both of these aspects are addressed within a continuum model of the dislocation pile-ups. A closed-form expression is obtained for the dependence of yield stress on grain size and source characteristics. The continuum model agrees closely with the corresponding discrete dislocation model even when the pile-up contains as few as ten dislocations. C1 Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Mat Sci & Mineral Engn, Berkeley, CA 94720 USA. Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. RP Friedman, LH (reprint author), Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. RI Friedman, Lawrence/G-5650-2011 OI Friedman, Lawrence/0000-0003-2416-9903 NR 17 TC 39 Z9 39 U1 0 U2 9 PU TAYLOR & FRANCIS LTD PI LONDON PA ONE GUNPOWDER SQUARE, LONDON EC4A 3DE, ENGLAND SN 0141-8610 J9 PHILOS MAG A JI Philos. Mag. A-Phys. Condens. Matter Struct. Defect Mech. Prop. PD MAY PY 1998 VL 77 IS 5 BP 1185 EP 1204 PG 20 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering; Physics, Applied; Physics, Condensed Matter SC Materials Science; Metallurgy & Metallurgical Engineering; Physics GA ZM973 UT WOS:000073595100004 ER PT J AU Silks, LA Wu, RL Dunlap, RB Odom, JD AF Silks, LA Wu, RL Dunlap, RB Odom, JD TI Synthesis and applications of chiral selones SO PHOSPHORUS SULFUR AND SILICON AND THE RELATED ELEMENTS LA English DT Article DE chiral selones; chiral derivatizing agents; aldol reactions AB The use of chiral selone derivatizing reagents (CDA's) and Se-77 NMR spectroscopy for the observation of remotely disposed chiral centers has proven to be a highly sensitive method for the determination of enantiomeric excesses. A variety of functional groups can be attached to these CDA's making them the most diverse class of CDA's yet developed. We are now investigating the chemistry unique to these CDA's such as new aldol reactions. C1 Los Alamos Natl Lab, Biosci & Biotechnol Grp, Los Alamos, NM 87545 USA. Univ S Carolina, Dept Chem & Biochem, Columbia, SC 29208 USA. RP Silks, LA (reprint author), Los Alamos Natl Lab, Biosci & Biotechnol Grp, CST-4,MS C345, Los Alamos, NM 87545 USA. NR 12 TC 4 Z9 4 U1 0 U2 0 PU GORDON BREACH PUBLISHING, TAYLOR & FRANCIS GROUP PI PHILADELPHIA PA 325 CHESTNUT ST, 8TH FL, PHILADELPHIA, PA 19106 USA SN 1042-6507 J9 PHOSPHORUS SULFUR JI Phosphorus Sulfur Silicon Relat. Elem. PD MAY-JUL PY 1998 VL 136 BP 209 EP 214 PG 6 WC Chemistry, Inorganic & Nuclear; Chemistry, Organic SC Chemistry GA V3230 UT WOS:000171897600016 ER PT J AU Silks, LA AF Silks, LA TI Synthesis of Se- and Te-containing amino acids: Useful probes for structural studies of proteins. SO PHOSPHORUS SULFUR AND SILICON AND THE RELATED ELEMENTS LA English DT Article DE selenium and tellurium-containing amino acids; [Se-77]-cystine and Te-cystine; telluromethionine and [4-C-13]telluro-methionine AB The synthesis of (1)-Se-cystine, (1)-[Se-77]-cystine and (1)-Te-cystine in 4 steps from commercially available 2(S)-[(tert-butoxycarbonyl)amino]-3-hydroxy-propionate has been accomplished. [4-C-13]Te-Met has been synthesized in a one pot reaction. C1 Los Alamos Natl Lab, Biosci & Biotechnol Grp, Los Alamos, NM 87545 USA. RP Silks, LA (reprint author), Los Alamos Natl Lab, Biosci & Biotechnol Grp, CST-4,MS C345, Los Alamos, NM 87545 USA. NR 23 TC 7 Z9 7 U1 0 U2 4 PU GORDON BREACH PUBLISHING, TAYLOR & FRANCIS GROUP PI PHILADELPHIA PA 325 CHESTNUT ST, 8TH FL, PHILADELPHIA, PA 19106 USA SN 1042-6507 J9 PHOSPHORUS SULFUR JI Phosphorus Sulfur Silicon Relat. Elem. PD MAY-JUL PY 1998 VL 136 BP 611 EP 616 DI 10.1080/10426509808042676 PG 6 WC Chemistry, Inorganic & Nuclear; Chemistry, Organic SC Chemistry GA V3230 UT WOS:000171897600079 ER PT J AU Kibitel, J Hejmadi, V Alas, L O'Connor, A Sutherland, BM Yarosh, D AF Kibitel, J Hejmadi, V Alas, L O'Connor, A Sutherland, BM Yarosh, D TI UV-DNA damage in mouse and human cells induces the expression of tumor necrosis factor alpha SO PHOTOCHEMISTRY AND PHOTOBIOLOGY LA English DT Article ID HUMAN-IMMUNODEFICIENCY-VIRUS; ULTRAVIOLET-B RADIATION; PYRIMIDINE DIMERS; CYTOKINE PRODUCTION; DERMAL FIBROBLASTS; IRRADIATED MICE; ENDONUCLEASE-V; STRAND BREAKS; UROCANIC ACID; SKIN-CANCER AB Ultraviolet light induces the expression of tumor necrosis factor alpha (TNF alpha) in many mammalian cells. We have examined the signal for this induction in a human DNA repair-deficient cell line carrying a transgene composed of the murine TNF regulatory sequences fused to the chloramphenicol acetyltransferase (CAT) structural gene. When compared by fluence, UVC was a more efficient inducer of CAT than was UVB, but they were equivalent inducers when compared by the frequency of cyclobutyl pyrimidine dimers produced by each source. Further, treatment of UV-irradiated cells with the prokaryotic DNA repair enzyme T4 endonuclease V increased the level of repair of dimers and concomitantly reduced CAT gene expression. Membrane-bound TNF alpha expression was increased by UV and reduced by repair of dimers. Finally, in the TNFcat transgene system, DNA damage directly to the cell with the transgene was required as cocultivation of unirradiated TNFcat cells with W-irradiated cells did not increase CAT activity. These results show that DNA damage is a signal for the induction of TNF alpha gene expression in mouse and human cells. C1 Appl Genet Inc, Freeport, NY 11520 USA. Brookhaven Natl Lab, Dept Biol, Upton, NY 11973 USA. RP Hejmadi, V (reprint author), Appl Genet Inc, 205 Buffalo Ave, Freeport, NY 11520 USA. NR 33 TC 52 Z9 54 U1 0 U2 1 PU AMER SOC PHOTOBIOLOGY PI AUGUSTA PA BIOTECH PARK, 1021 15TH ST, SUITE 9, AUGUSTA, GA 30901-3158 USA SN 0031-8655 J9 PHOTOCHEM PHOTOBIOL JI Photochem. Photobiol. PD MAY PY 1998 VL 67 IS 5 BP 541 EP 546 DI 10.1111/j.1751-1097.1998.tb09452.x PG 6 WC Biochemistry & Molecular Biology; Biophysics SC Biochemistry & Molecular Biology; Biophysics GA ZP864 UT WOS:000073796300013 PM 9644008 ER PT J AU Yocky, DA Johnson, BF AF Yocky, DA Johnson, BF TI Repeat-pass dual-antenna synthetic aperture radar interferometric change-detection post-processing SO PHOTOGRAMMETRIC ENGINEERING AND REMOTE SENSING LA English DT Article AB Synthetic aperture radar (SAR) interferometric change-detection (ICD) maps are highly sensitive to both macro and micro temporal changes in SAR surface reflectivity. This change is detected as decorrelations in the complex cross-correlation between two SAR complex images collected at different times. However, in many instances, numerous detected decorrelations are not due to changes during the elapsed time,but due to other decorrelating effects. Using information from a repeat-pass, dual-antenna interferometric SAR (IFSAR) change pair, we were able to identify over 70 percent of the ICD correlations less than 0.80 as non-temporal changes, or false changes. The remaining temporal changes coincided well with controlled changes made in the scene. Our post-processing results show the IFSAR coherence maps to be the most informative SAR data component for such false temporal change analysis. C1 Sandia Natl Labs, Syst Anal Dept 2, Albuquerque, NM 87185 USA. RP Yocky, DA (reprint author), Sandia Natl Labs, Syst Anal Dept 2, POB 5800, Albuquerque, NM 87185 USA. EM dayocky@sandia.gov NR 12 TC 7 Z9 7 U1 1 U2 1 PU AMER SOC PHOTOGRAMMETRY PI BETHESDA PA 5410 GROSVENOR LANE SUITE 210, BETHESDA, MD 20814-2160 USA SN 0099-1112 J9 PHOTOGRAMM ENG REM S JI Photogramm. Eng. Remote Sens. PD MAY PY 1998 VL 64 IS 5 BP 425 EP 429 PG 5 WC Geography, Physical; Geosciences, Multidisciplinary; Remote Sensing; Imaging Science & Photographic Technology SC Physical Geography; Geology; Remote Sensing; Imaging Science & Photographic Technology GA ZP504 UT WOS:000073760100005 ER PT J AU Lam, PM Akanbi, I Newman, DE AF Lam, PM Akanbi, I Newman, DE TI Effects of randomness and spatially dependent relaxation on sandpile models SO PHYSICA A LA English DT Article ID SELF-ORGANIZED CRITICALITY AB We investigate two types of randomness in the relaxation of sandpile models when the slope at some point becomes over critical. In one type of randomness, the number of particles n(f), falling to its nearest neighbors in the resulting relaxation, is not constant but random, even though an equal number fall in each direction. We find that this kind of randomness does not change the universality class of the models. Another type of randomness is introduced by having all ni particles to fall in one single direction, but with the direction chosen randomly. We find that this type of randomness has a strong effect on the universality of the models. (C) 1998 Elsevier Science B.V. All rights reserved. C1 So Univ, Dept Phys, Baton Rouge, LA 70813 USA. Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Lam, PM (reprint author), So Univ, Dept Phys, Baton Rouge, LA 70813 USA. NR 3 TC 0 Z9 0 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0378-4371 J9 PHYSICA A JI Physica A PD MAY 1 PY 1998 VL 253 IS 1-4 BP 307 EP 314 DI 10.1016/S0378-4371(97)00679-1 PG 8 WC Physics, Multidisciplinary SC Physics GA ZY333 UT WOS:000074609900025 ER PT J AU Marsili, M Maslov, S Zhang, YC AF Marsili, M Maslov, S Zhang, YC TI Dynamical optimization theory of a diversified portfolio SO PHYSICA A-STATISTICAL MECHANICS AND ITS APPLICATIONS LA English DT Article AB We propose and study a simple model of dynamical redistribution of capital in a diversified portfolio. We consider a hypothetical situation of a portfolio composed of Ai uncorrelated stocks. Each stock price follows a multiplicative random walk with identical drift and dispersion. The rules of our model naturally give rise to power law tails in the distribution of capital fractions invested in different stocks. The exponent of this scale free distribution is calculated in both discrete and continuous time formalism. It is demonstrated that the dynamical redistribution strategy results in a larger typical growth rate of the capital than a static "buy-and-hold" strategy. In the large N limit the typical growth rate is shown to asymptotically approach that of the expectation value of the stock price. The finite dimensional variant of the model is shown to describe the partition function of directed polymers in random media. (C) 1998 Elsevier Science B.V. All rights reserved. C1 Univ Fribourg, Inst Phys Theor, CH-1700 Fribourg, Switzerland. Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. RP Univ Fribourg, Inst Phys Theor, CH-1700 Fribourg, Switzerland. RI Maslov, Sergei/C-2397-2009 OI Maslov, Sergei/0000-0002-3701-492X NR 13 TC 43 Z9 43 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0378-4371 EI 1873-2119 J9 PHYSICA A JI Physica A PD MAY 1 PY 1998 VL 253 IS 1-4 BP 403 EP 418 DI 10.1016/S0378-4371(98)00075-2 PG 16 WC Physics, Multidisciplinary SC Physics GA ZY333 UT WOS:000074609900034 ER PT J AU Brooks, JS Engel, L Cothern, J Simmons, JA Hafich, MJ Lewis, W Gallegos, S Devore, D Marshall, B Grover, M Leach, G Mielke, CH Rickel, D Clark, D Fowler, M King, J Tabaka, L Detwiler, J Clark, EC Clark, RG Dzurak, A Kane, B Miura, N Tatsenko, O Platonov, V Bykov, A AF Brooks, JS Engel, L Cothern, J Simmons, JA Hafich, MJ Lewis, W Gallegos, S Devore, D Marshall, B Grover, M Leach, G Mielke, CH Rickel, D Clark, D Fowler, M King, J Tabaka, L Detwiler, J Clark, EC Clark, RG Dzurak, A Kane, B Miura, N Tatsenko, O Platonov, V Bykov, A TI Dirac II series in 800 T fields: Reflectivity measurements on low-dimensional, low electron density materials SO PHYSICA B LA English DT Article; Proceedings Paper CT 5th International Symposium on Research in High Magnetic Fields CY AUG 04-06, 1997 CL SYDNEY, AUSTRALIA DE semiconductors; high magnetic fields; optical measurements; molecular conductors AB We report reflectivity measurements at 810 nm wavelength on GaAs/GaAlAs multiple quantum wells and NbSe2 layers at 75 K up to magnetic fields of 800 T. In the GaAs system, we observed in two separate measurements new, reproducible oscillatory phenomena in the reflectivity between 30 and 800 T, and in a third measurement on 2H-NbSe2 we observed a decrease in reflectivity of about 50% above 200 T, with some additional evidence for oscillatory behavior. We discuss these measurements based on the expected behavior in terms of their known physical properties, and consider future prospects for the application of optical methods to study condensed matter physics under these extremes. (C) 1998 Elsevier Science B.V. All rights reserved. C1 Florida State Univ, Dept Phys, Tallahassee, FL 32310 USA. Florida State Univ, NHMFL, Tallahassee, FL 32310 USA. Sandia Natl Labs, Albuquerque, NM 87185 USA. Bechtel Nevada, Los Alamos, NM 87544 USA. Bechtel Nevada, STL, Santa Barbara, CA 93111 USA. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87544 USA. NHMFL, Los Alamos, NM 87544 USA. Univ New S Wales, Sydney, NSW, Australia. PFML, Sydney, NSW, Australia. Univ Tokyo, Tokyo, Japan. ISSP, Tokyo, Japan. Inst Expt Phys, Nizhnii Novgorod, Sarov, Russia. RP Brooks, JS (reprint author), Florida State Univ, Dept Phys, 1800 E Paul Dirac Dr, Tallahassee, FL 32310 USA. RI Dzurak, Andrew/C-5973-2009 NR 5 TC 1 Z9 1 U1 0 U2 4 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4526 J9 PHYSICA B JI Physica B PD MAY PY 1998 VL 246 BP 50 EP 53 DI 10.1016/S0921-4526(98)00024-6 PG 4 WC Physics, Condensed Matter SC Physics GA ZY829 UT WOS:000074665400011 ER PT J AU Boebinger, GS Brazovskii, S Campbell, LJ AF Boebinger, GS Brazovskii, S Campbell, LJ TI Condensed matter physics for non-destructive 100 T magnets SO PHYSICA B LA English DT Article; Proceedings Paper CT 5th International Symposium on Research in High Magnetic Fields CY AUG 04-06, 1997 CL SYDNEY, AUSTRALIA DE superconductors; layered systems ID ZERO-TEMPERATURE LIMIT; CONDUCTING POLYMERS; LUTTINGER LIQUIDS; STATE; SUPERCONDUCTIVITY; SKYRMIONS; FIELDS; LOCALIZATION; OSCILLATIONS; BIPOLARONS AB Various topics in condensed matter physics are cited as potential beneficiaries of non-destructive 100 T magnets now being designed. These include layered systems, metals, superconductors, semi-metals, narrow gap and doped semiconductors, as well as systems of spin-polarized superstructures, real space Cooper pairs, and bipolarons. An extensive bibliography is provided. (C) 1998 Elsevier Science B.V. All rights reserved. C1 Univ Calif Los Alamos Natl Lab, Natl High Magnet Field Lab, Los Alamos, NM 87545 USA. Lucent Technol, Bell Labs, Murray Hill, NJ 07974 USA. LD Landau Theoret Phys Inst, Moscow, Russia. RP Campbell, LJ (reprint author), Univ Calif Los Alamos Natl Lab, Natl High Magnet Field Lab, MS-E536, Los Alamos, NM 87545 USA. EM ljcampbell@alum.mit.edu RI Brazovskii, Serguei/A-9608-2012 OI Brazovskii, Serguei/0000-0001-8147-9655 NR 72 TC 2 Z9 2 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4526 J9 PHYSICA B JI Physica B PD MAY PY 1998 VL 246 BP 61 EP 66 DI 10.1016/S0921-4526(98)00026-X PG 6 WC Physics, Condensed Matter SC Physics GA ZY829 UT WOS:000074665400013 ER PT J AU Lacerda, AH Mielke, CH Harrison, N Beyermann, WP Yatskar, A Canfield, PC Bud'ko, SL Schmiedeshoff, GM Torikachvili, MS Vestal, RM Montgomery, LK AF Lacerda, AH Mielke, CH Harrison, N Beyermann, WP Yatskar, A Canfield, PC Bud'ko, SL Schmiedeshoff, GM Torikachvili, MS Vestal, RM Montgomery, LK TI Unconventional metals at low temperatures and high magnetic fields SO PHYSICA B LA English DT Article; Proceedings Paper CT 5th International Symposium on Research in High Magnetic Fields CY AUG 04-06, 1997 CL SYDNEY, AUSTRALIA ID HEAVY-FERMION SYSTEMS; ORGANIC SUPERCONDUCTOR; BEDT-TTF; TRANSITION; KAPPA-(BEDT-TTF)(2)CU(NCS)(2) AB This paper focuses on recent magnetotransport and magnetization measurements on unconventional metals and molecular conductors down to 350 mK and in magnetic fields up to 60 T. Measurements were performed at the National High Magnetic Field Laboratory - Los Alamos Facility. Three variants of unconventional materials will be presented. First, the magnetic field effects on the thermodynamic and magnetotransport properties of the Fermi liquid regime of the heavy Fermion compound YbNi2B2C. Second, we present recent investigations of the Fermiology of the pnictide compound SmSb2 by means of Shubnikov-de Haas and de Haas-van Alphen quantum oscillations. Finally, we present recent Fermi surface measurements of kappa-(ET)(2)Cu[N(CN)(2)]Br, the layered organic superconductor with the highest T-c at ambient pressure. (C) 1998 Elsevier Science B.V. All rights reserved. C1 Univ Calif Los Alamos Natl Lab, Pulse Facil, Natl High Magnet Field Lab, Los Alamos, NM 87545 USA. Univ Calif Riverside, Dept Phys, Riverside, CA 92521 USA. Iowa State Univ, Ames Lab, Ames, IA 50011 USA. Occidental Coll, Dept Phys, Los Angeles, CA 90041 USA. San Diego State Univ, Dept Phys, San Diego, CA 92182 USA. Indiana Univ, Dept Phys, Bloomington, IN 47405 USA. RP Lacerda, AH (reprint author), Univ Calif Los Alamos Natl Lab, Pulse Facil, Natl High Magnet Field Lab, MST 10, Los Alamos, NM 87545 USA. EM lacerda@lanl.gov RI Canfield, Paul/H-2698-2014 NR 28 TC 4 Z9 4 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4526 J9 PHYSICA B JI Physica B PD MAY PY 1998 VL 246 BP 97 EP 103 DI 10.1016/S0921-4526(98)00033-7 PG 7 WC Physics, Condensed Matter SC Physics GA ZY829 UT WOS:000074665400020 ER PT J AU Wosnitza, J Goll, G Beckmann, D Wanka, S Schlueter, JA Williams, JM Nixon, PG Winter, RW Gard, GL AF Wosnitza, J Goll, G Beckmann, D Wanka, S Schlueter, JA Williams, JM Nixon, PG Winter, RW Gard, GL TI Organic conductors: Fermi-surface and specific-heat studies SO PHYSICA B LA English DT Article; Proceedings Paper CT 5th International Symposium on Research in High Magnetic Fields CY AUG 04-06, 1997 CL SYDNEY, AUSTRALIA DE organic superconductors; fermi surface; heat capacity ID OSCILLATIONS; QUANTUM; ANION AB We briefly review some of the recent high-field de Haas-van Alphen (dHvA) results we obtained for the quasi-two-dimensional organic metals and superconductors of the type alpha-(ET)(2)X, where ET (=BEDT-TTF) is bis(ethylenedithio)-tetrathiafulvalene and X is a monovalent anion. We further report on new dHvA, Shubnikov-de Haas, and specific-heat results for the recently synthesized organic superconductor beta"-(ET)(2)SF5CH3CF2SO3 (T-c = 4.5 K). The Fermi-surface topology, the possible influence of the low dimensionality on the quantum oscillations, and the influence of many-body interactions are discussed. The results indicate the importance of electron-phonon interaction and point towards strong coupling. (C) 1998 Elsevier Science B.V. All rights reserved. C1 Univ Karlsruhe, Inst Phys, D-76128 Karlsruhe, Germany. Max Planck Inst Festkorperforsch, Grenoble High Magnet Field Lab, F-38042 Grenoble, France. CNRS, F-38042 Grenoble, France. Argonne Natl Lab, Div Chem, Argonne, IL 60439 USA. Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. Portland State Univ, Dept Chem, Portland, OR 97207 USA. RP Wosnitza, J (reprint author), Univ Karlsruhe, Inst Phys, Engesserstr 7, D-76128 Karlsruhe, Germany. NR 24 TC 13 Z9 13 U1 1 U2 5 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4526 J9 PHYSICA B JI Physica B PD MAY PY 1998 VL 246 BP 104 EP 109 DI 10.1016/S0921-4526(98)00034-9 PG 6 WC Physics, Condensed Matter SC Physics GA ZY829 UT WOS:000074665400021 ER PT J AU Hill, S Brooks, JS Qualls, JS Burgin, T Fravel, B Montgomery, LK Sarrao, J Fisk, Z AF Hill, S Brooks, JS Qualls, JS Burgin, T Fravel, B Montgomery, LK Sarrao, J Fisk, Z TI Millimeter-wave spectroscopy of low-dimensional molecular metals in high magnetic fields SO PHYSICA B LA English DT Article; Proceedings Paper CT 5th International Symposium on Research in High Magnetic Fields CY AUG 04-06, 1997 CL SYDNEY, AUSTRALIA DE cyclotron resonance; low-dimensional conductors; Fermi surface ID CYCLOTRON-RESONANCE AB We have used a cavity perturbation technique to probe the electrodynamic response of various low-dimensional molecular metals in high magnetic fields. We discuss some of the technical aspects of these measurements and go on to present recent experimental data obtained in magnetic fields of up to 33 T. In addition to providing finite frequency information in this frequency range, which is highly relevant to narrow bandwidth conducting systems, we show how the extreme flexibility and sensitivity of this technique offers great potential for probing the properties of novel materials in high magnetic fields. (C) 1998 Elsevier Science B.V. All rights reserved. C1 Montana State Univ, Dept Phys, Bozeman, MT 59717 USA. Florida State Univ, Natl High Magnet Field Lab, Tallahassee, FL 32310 USA. Indiana Univ, Dept Chem, Bloomington, IN 47405 USA. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Hill, S (reprint author), Montana State Univ, Dept Phys, Bozeman, MT 59717 USA. RI Hill, Stephen/J-5383-2014 OI Hill, Stephen/0000-0001-6742-3620 NR 26 TC 12 Z9 12 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4526 J9 PHYSICA B JI Physica B PD MAY PY 1998 VL 246 BP 110 EP 116 DI 10.1016/S0921-4526(98)00035-0 PG 7 WC Physics, Condensed Matter SC Physics GA ZY829 UT WOS:000074665400022 ER PT J AU de Boer, FR Kindo, K Nakotte, H Prokes, K Sechovsky, V AF de Boer, FR Kindo, K Nakotte, H Prokes, K Sechovsky, V TI U2T2X (T=Co, Ni, Rh, Pd, Ir, Pt, X=In, Sn) compounds in high magnetic fields SO PHYSICA B LA English DT Article; Proceedings Paper CT 5th International Symposium on Research in High Magnetic Fields CY AUG 04-06, 1997 CL SYDNEY, AUSTRALIA DE U2T2X compounds; 5f-ligand hybridization; magnetization; metamagnetic transition ID SN-119 MOSSBAUER-SPECTROSCOPY; EQUIVALENT-TO-FE; U(2)T(2)X COMPOUNDS; ELECTRICAL-RESISTIVITY; ELECTRONIC-PROPERTIES; CRYSTAL-STRUCTURE; U2NI2IN; DIFFRACTION; U2PT2SN; U2M2SN AB High-field magnetization measurements are reviewed, performed on compounds with stoichiometry U2T2X (T = Co, Ni, Rh, Pd, Tr, Pt; X = In, Sn), up to 38 T in the High-Field Installation at the University of Amsterdam, up to 57 T in the High-Field Facility at Osaka University and, in some cases, up to 55 T in the National High Magnetic Field Laboratory, Los Alamos. Variations of the hybridization of the 5f-electron states with the d and p states of the surrounding ligands play a substantial role in the evolution of ground states ranging from Pauli-paramagnetic ground states (U2Co2In, U2Rh2In, U2Ir2In, U2Pt2In, U2Co2Sn, U2Ir2Sn) to long-range antiferromagnetic order with well-developed U moments (U2Ni2In, U2Pd2In, U2Ni2Sn, U2Rh2Sn, U2Pd2Sn, U2Pt2Sn). At relatively high magnetic fields, the antiferromagnetically ordered compounds undergo metamagnetic phase transitions, presumably to the forced ferromagnetic state. However, the magnetization steps corresponding to these transitions are usually small as well as the magnetization values at the highest fields. In all cases, in high fields, no tendencies to saturation are observed, which points to field-induced moments, on the U and/or on the transition-metal sites. (C) 1998 Elsevier Science B.V. All rights reserved. C1 Univ Amsterdam, VanderWaals Zeeman Inst, NL-1018 XE Amsterdam, Netherlands. Osaka Univ, Extreme Mat Res Ctr, Toyonaka, Osaka 560, Japan. Univ Calif Los Alamos Natl Lab, Manuel Lujan Jr Neutron Scattering Ctr, Los Alamos, NM 87545 USA. Charles Univ, Dept Met Phys, CR-12116 Prague 2, Czech Republic. RP de Boer, FR (reprint author), Univ Amsterdam, VanderWaals Zeeman Inst, NL-1018 XE Amsterdam, Netherlands. RI Sechovsky, Vladimir/A-5256-2008 OI Sechovsky, Vladimir/0000-0003-1298-2120 NR 27 TC 2 Z9 2 U1 1 U2 13 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4526 J9 PHYSICA B JI Physica B PD MAY PY 1998 VL 246 BP 129 EP 134 DI 10.1016/S0921-4526(98)00039-8 PG 6 WC Physics, Condensed Matter SC Physics GA ZY829 UT WOS:000074665400026 ER PT J AU McCall, S Cao, G Crow, JE Harrison, N Mielke, CH Lacerda, AH Guertin, RP AF McCall, S Cao, G Crow, JE Harrison, N Mielke, CH Lacerda, AH Guertin, RP TI Metamagnetism of single crystal Ca3Ru2O7 in high magnetic fields SO PHYSICA B LA English DT Article; Proceedings Paper CT 5th International Symposium on Research in High Magnetic Fields CY AUG 04-06, 1997 CL SYDNEY, AUSTRALIA DE metal-nonmetal transition; antiferromagnetism; meta-magnetism ID V2O3; TRANSITION; SUPERCONDUCTIVITY; PEROVSKITE AB Ca3Ru2O7, which has a double-layered structure related to perovskites and high-T-c cuprates, exhibits several coupled magnetic and transport phases. As-grown single crystals have nonmetallic conductivity for T < T-M = 48 K, antiferromagnetic ordering up to T-N = 56 K and "bad metal" conductivity, linear in temperature for T > T-N. The current study reveals a metamagnetic transition with an accompanying nonmetal to metal transition found in pulsed high magnetic fields (H-c = 37 T) for the field directed perpendicular to the Ru-O planes in the "hard" axis (001) direction of this highly anisotropic system. By contrast, the transition occurs at 6T for the field along the "easy" axis (110). The resistivity for current along(110) or (001) is anisotropic in zero field at low temperatures but becomes isotropic with H > H-c applied along the easy axis, in contrast to results expected from Fermi-liquid models. (C) 1998 Elsevier Science B.V. All rights reserved. C1 Florida State Univ, Natl High Magnet Field Lab, Tallahassee, FL 32310 USA. Univ Calif Los Alamos Natl Lab, Natl High Magnet Field Lab, Los Alamos, NM 87545 USA. Tufts Univ, Medford, MA 02155 USA. RP McCall, S (reprint author), Florida State Univ, Natl High Magnet Field Lab, Tallahassee, FL 32310 USA. RI McCall, Scott/G-1733-2014 OI McCall, Scott/0000-0002-7979-4944 NR 21 TC 1 Z9 1 U1 0 U2 6 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4526 J9 PHYSICA B JI Physica B PD MAY PY 1998 VL 246 BP 144 EP 148 DI 10.1016/S0921-4526(98)00042-8 PG 5 WC Physics, Condensed Matter SC Physics GA ZY829 UT WOS:000074665400029 ER PT J AU Fowler, CM AF Fowler, CM TI Four decades in the megagauss world SO PHYSICA B LA English DT Article; Proceedings Paper CT 5th International Symposium on Research in High Magnetic Fields CY AUG 04-06, 1997 CL SYDNEY, AUSTRALIA DE megagauss fields; explosives; magnetic flux compression ID MAGNETIC-FIELD AB This paper contains a short history of the generation and application of megagauss magnetic fields obtained by explosive flux compression at Los Alamos over the last four decades, a brief description of the high field systems most commonly used for solid state research, and a survey of results obtained from a Los Alamos shot series in which Russian built high field generators were also used, the forerunner of the later Dirac 1 and 2 shot series. (C) 1998 Elsevier Science B.V. All rights reserved. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Fowler, CM (reprint author), Univ Calif Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 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 0921-4526 J9 PHYSICA B JI Physica B PD MAY PY 1998 VL 246 BP 158 EP 163 DI 10.1016/S0921-4526(98)00045-3 PG 6 WC Physics, Condensed Matter SC Physics GA ZY829 UT WOS:000074665400032 ER PT J AU Perry, CH Kim, Y Rickel, DG AF Perry, CH Kim, Y Rickel, DG TI Photoluminescence studies of quantum-well structures in pulsed magnetic fields SO PHYSICA B LA English DT Article; Proceedings Paper CT 5th International Symposium on Research in High Magnetic Fields CY AUG 04-06, 1997 CL SYDNEY, AUSTRALIA DE quantum wells; semiconductor heterostructures; magneto-photoluminescence; pulsed magnetic fields ID HALL REGIME; OPTICAL RECOMBINATION; GROUND-STATE; MAGNETOEXCITONS AB Magneto-photoluminescence spectroscopy at low temperatures has proved to be a powerful technique for investigating the electronic states of quantum well-type semiconductor heterostructures and offers a complimentary tool to electrical transport studies. We have established a magneto-optical facility at NHMFL-LANL and have undertaken a comprehensive investigation of magneto-excitonic and Landau transitions in a large variety of undoped and doped quantum-well structures. Fiber optic probes are used to switch between steady state (to 18 T) and pulsed (to 65 T) magnetic fields applied perpendicular (Faraday geometry) and parallel (Voigt geometry) to the growth axis of the 2D layers. The pulsed field mode requires that the spectroscopic data acquisition to be obtained in 1-2 ms in the 'flat-top' region at the peak of the field. A broad range of samples have been investigated in pulsed magnetic fields as a function of temperature, sample geometry, and high pressure. Examples include single and coupled double quantum wells, modulation-doped quantum wells, and single interface heterojunction structures. (C) 1998 Elsevier Science B.V. All rights reserved. C1 Northeastern Univ, Dept Phys, Boston, MA 02115 USA. Univ Calif Los Alamos Natl Lab, Natl High Magnet Field Lab, Los Alamos, NM 87545 USA. RP Perry, CH (reprint author), Northeastern Univ, Dept Phys, Boston, MA 02115 USA. NR 18 TC 14 Z9 14 U1 1 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4526 J9 PHYSICA B JI Physica B PD MAY PY 1998 VL 246 BP 182 EP 187 DI 10.1016/S0921-4526(98)00006-4 PG 6 WC Physics, Condensed Matter SC Physics GA ZY829 UT WOS:000074665400037 ER PT J AU Tatsenko, OM Platonov, VV Bykov, AI Dolotenko, MI Zvezdin, AK Solem, JC Fowler, CM Goettee, JD Rickel, D Campbell, LJ Veeser, L Sheppard, M Lacerda, AH King, JC Rodriguez, PJ Bartram, DE Clark, RG Kane, BE Dzurak, AS Facer, GR Miura, N Takamasu, T Nakagawa, H Yokoi, H Brooks, JS Engel, LW Pfeiffer, L West, KW Maverick, AW Butler, LG Lewis, W Gallegos, CH Marshall, B AF Tatsenko, OM Platonov, VV Bykov, AI Dolotenko, MI Zvezdin, AK Solem, JC Fowler, CM Goettee, JD Rickel, D Campbell, LJ Veeser, L Sheppard, M Lacerda, AH King, JC Rodriguez, PJ Bartram, DE Clark, RG Kane, BE Dzurak, AS Facer, GR Miura, N Takamasu, T Nakagawa, H Yokoi, H Brooks, JS Engel, LW Pfeiffer, L West, KW Maverick, AW Butler, LG Lewis, W Gallegos, CH Marshall, B TI Quantum jumps in magneto-optical effects and magnetization of rare-earth compounds in ultrahigh magnetic fields SO PHYSICA B LA English DT Article; Proceedings Paper CT 5th International Symposium on Research in High Magnetic Fields CY AUG 04-06, 1997 CL SYDNEY, AUSTRALIA DE quantum jump; Faraday rotation; high magnetic field AB The experimental results of Faraday rotation (FR) measurements in the sample with Eu3+ ion at 4 K in high magnetic fields up to 700 T ('Dirac Series' - Los Alamos) are presented. The magnetic field is produced by the explosive-driven flux-compression generator MC-1. Measurements have been carried using 850 nm light at liquid helium temperature. The magnetic field-induced quantum reorientation of the spin and orbital magnetic moments in the Sm3+ and Eu3+ ions have been investigated. (C) 1998 Elsevier Science B.V. All rights reserved. C1 Russian Fed Nucl Ctr, VNIIEF, Sarov 607200, Nizhni Novgorod, Russia. Russian Acad Sci, Inst Gen Phys, Moscow, Russia. Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Univ New S Wales, Kensington, NSW 2033, Australia. Univ Tokyo, ISSP, Tokyo, Japan. NIMCR, Tsukuba, Ibaraki, Japan. Florida State Univ, NHMFL, Tallahassee, FL 32306 USA. Lucent Technol, Murray Hill, NJ 07974 USA. Louisiana State Univ, Baton Rouge, LA 70803 USA. Bechtel Nevada, Las Vegas, NV 89193 USA. RP Tatsenko, OM (reprint author), Russian Fed Nucl Ctr, VNIIEF, 37 Mira St, Sarov 607200, Nizhni Novgorod, Russia. RI Dzurak, Andrew/C-5973-2009; Zvezdin, Anatoly/K-2072-2013; Goettee, Jeffrey/L-4926-2015; Butler, Leslie/D-1636-2016 OI Butler, Leslie/0000-0003-1547-608X NR 10 TC 0 Z9 0 U1 1 U2 5 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4526 J9 PHYSICA B JI Physica B PD MAY PY 1998 VL 246 BP 315 EP 318 DI 10.1016/S0921-4526(97)00924-1 PG 4 WC Physics, Condensed Matter SC Physics GA ZY829 UT WOS:000074665400068 ER PT J AU Platonov, VV Tatsenko, OM Bykov, AI Dolotenko, MI Solem, JC Fowler, CM Goettee, JD Rickel, D Campbell, LJ Veeser, L Sheppard, M Lacerda, AH King, JC Rodriguez, PJ Bartram, DE Clark, RG Kane, BE Dzurak, AS Facer, GR Miura, N Takamasu, T Nakagawa, H Yokoi, H Brooks, JS Engel, LW Pfeiffer, L West, KW Maverick, AW Butler, LG Lewis, W Gallegos, CH Marshall, B AF Platonov, VV Tatsenko, OM Bykov, AI Dolotenko, MI Solem, JC Fowler, CM Goettee, JD Rickel, D Campbell, LJ Veeser, L Sheppard, M Lacerda, AH King, JC Rodriguez, PJ Bartram, DE Clark, RG Kane, BE Dzurak, AS Facer, GR Miura, N Takamasu, T Nakagawa, H Yokoi, H Brooks, JS Engel, LW Pfeiffer, L West, KW Maverick, AW Butler, LG Lewis, W Gallegos, CH Marshall, B TI The Faraday effect in Cd0.57Mn0.43Te in high magnetic field SO PHYSICA B LA English DT Article; Proceedings Paper CT 5th International Symposium on Research in High Magnetic Fields CY AUG 04-06, 1997 CL SYDNEY, AUSTRALIA DE Cd1-xMnxTe; Faraday rotation; high magnetic field ID SEMICONDUCTORS AB The experimental results of Faraday rotation (FR) measurements in dilute magnetic semiconductors in high magnetic field ('Dirac Series' - Los Alamos) are presented. The magnetic field is produced by an explosive-driven flux-compression generator (150 T). Measurements have been carried with samples of Cd1-xMnxTe with x = 0.43 using 633 nm light at liquid helium temperature. The FR increases in such samples when the magnetic field exceeds 60 T. Interband exchange interaction and the direct influence of the external magnetic field on the exchange interaction must be considered to interpret the experimental results. (C) 1998 Elsevier Science B.V. All rights reserved. C1 Russian Fed Nucl Ctr, VNIIEF, Sarov 607190, Nizhni Novgorod, Russia. Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Univ New S Wales, Kensington, NSW 2033, Australia. Univ Tokyo, ISSP, Tokyo, Japan. NIMCR, Tsukuba, Ibaraki, Japan. Florida State Univ, NHMFL, Tallahassee, FL 32306 USA. Lucent Technol, Murray Hill, NJ 07974 USA. Louisiana State Univ, Baton Rouge, LA 70803 USA. Bechtel Nevada, Las Vegas, NV 89193 USA. RP Platonov, VV (reprint author), Russian Fed Nucl Ctr, VNIIEF, 37 Mira St, Sarov 607190, Nizhni Novgorod, Russia. RI Dzurak, Andrew/C-5973-2009; Goettee, Jeffrey/L-4926-2015; Butler, Leslie/D-1636-2016 OI Butler, Leslie/0000-0003-1547-608X 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 0921-4526 J9 PHYSICA B JI Physica B PD MAY PY 1998 VL 246 BP 319 EP 322 DI 10.1016/S0921-4526(97)00925-3 PG 4 WC Physics, Condensed Matter SC Physics GA ZY829 UT WOS:000074665400069 ER PT J AU Zerwekh, WD Goettee, JD AF Zerwekh, WD Goettee, JD TI A 94 GHz interferometer for use in establishing the upper critical field in YBCO SO PHYSICA B LA English DT Article; Proceedings Paper CT 5th International Symposium on Research in High Magnetic Fields CY AUG 04-06, 1997 CL SYDNEY, AUSTRALIA DE 94 GHz interferometer; upper critical field; YBCO AB This paper describes a 94 GHz interferometer that was used to measure the change in the complex impedance in a thin-film, high-temperature superconductor (YBCO) when under the influence of an extremely high-pulsed magnetic field. It will review the design features necessary to meet the experimental requirements, describe the circuit used, outline the experimental setup, and present a set of data obtained at 4 K. (C) 1998 Elsevier Science B.V. All rights reserved. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Zerwekh, WD (reprint author), Univ Calif Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. RI Goettee, Jeffrey/L-4926-2015 NR 1 TC 0 Z9 0 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4526 J9 PHYSICA B JI Physica B PD MAY PY 1998 VL 246 BP 353 EP 355 DI 10.1016/S0921-4526(97)00933-2 PG 3 WC Physics, Condensed Matter SC Physics GA ZY829 UT WOS:000074665400077 ER PT J AU Nakotte, H Hagmusa, IH Klaasse, JCP Torikachvili, MS Lacerda, AH Bruck, E Prokes, K de Boer, FR AF Nakotte, H Hagmusa, IH Klaasse, JCP Torikachvili, MS Lacerda, AH Bruck, E Prokes, K de Boer, FR TI Magnetic phase diagrams of UNiGe SO PHYSICA B LA English DT Article; Proceedings Paper CT 5th International Symposium on Research in High Magnetic Fields CY AUG 04-06, 1997 CL SYDNEY, AUSTRALIA DE magnetic-phase diagram; antiferromagnetism; uranium compounds AB UNiGe undergoes two magnetic transitions in zero held. Here, the magnetic diagrams of UNiGe for B parallel to b and B parallel to c are reported. We performed temperature scans of the magnetization in static magnetic fields up to 19.5 T applied along the b and c axes. For both orientations three magnetic phases have been identified in the B-T diagrams. We confirmed the previously reported phase boundaries for B parallel to c, and in addition we determined the location of the phase boundaries for B parallel to b. We discuss a possible relationship of the two zero-field antiferromagnetic phases (commensurate: T < 42 K; incommensurate: 42 K < T < 50 K) and the field-induced phase, which at low temperatures, occurs between 18 and 25 T or 4 and 10 T for B parallel to b or B parallel to c, respectively. Finally, we discuss the field dependence of the electronic contribution gamma to the specific heat for B parallel to c up to 17.5 T, and we find that its field dependence is similar to the one found in more itinerant uranium compounds. (C) 1998 Elsevier Science B.V. All rights reserved. C1 Univ Amsterdam, VanderWaals Zeeman Inst, NL-1018 XE Amsterdam, Netherlands. Univ Calif Los Alamos Natl Lab, MLNSC, Los Alamos, NM 87545 USA. San Diego State Univ, Dept Phys, San Diego, CA 92182 USA. Univ Calif Los Alamos Natl Lab, Pulsed Field Facil, NHMFL, Los Alamos, NM 87545 USA. RP Bruck, E (reprint author), Univ Amsterdam, VanderWaals Zeeman Inst, Valckenierstr 65, NL-1018 XE Amsterdam, Netherlands. RI Bruck, Ekkes/E-3365-2014 NR 9 TC 3 Z9 3 U1 1 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4526 J9 PHYSICA B JI Physica B PD MAY PY 1998 VL 246 BP 441 EP 444 DI 10.1016/S0921-4526(97)00956-3 PG 4 WC Physics, Condensed Matter SC Physics GA ZY829 UT WOS:000074665400099 ER PT J AU Singleton, J Harrison, N Honold, MM Yaguchi, H Mielke, C Rickel, D Deckers, I Reinders, PHP Herlach, F Kurmoo, M Day, P AF Singleton, J Harrison, N Honold, MM Yaguchi, H Mielke, C Rickel, D Deckers, I Reinders, PHP Herlach, F Kurmoo, M Day, P TI Chiral Fermi liquids and a new version of the quantum Hall effect observed in organic conductors at very high magnetic fields SO PHYSICA B-CONDENSED MATTER LA English DT Article; Proceedings Paper CT 5th International Symposium on Research in High Magnetic Fields CY AUG 04-06, 1997 CL SYDNEY, AUSTRALIA DE organic metal; quantum Hall effect ID BULK; ALPHA-(BEDT-TTF)(2)KHG(SCN)(4); OSCILLATIONS; SURFACE; STATES; PHASE AB We present evidence for a new form of quantum Hall effect (QHE) in organic molecular metals, in which the chemical potential is pinned to quasi-one-dimensional states between sharp quasi-two-dimensional Landau levels over finite regions of magnetic fields. A dramatic change in the behaviour of the resistivity component rho(zz) occurs when the QHE is observed, suggesting the presence of a chiral Fermi liquid at the sample edges. (C) 1998 Elsevier Science B.V. All rights reserved. C1 Univ Oxford, Dept Phys, Clarendon Lab, Oxford OX1 3PU, England. Los Alamos Natl Lab, Natl High Magnet Field Lab, Los Alamos, NM 87545 USA. Katholieke Univ Leuven, Vaste Stof Fys & Magnetisme Lab, B-3001 Heverlee, Belgium. UCL Royal Inst Great Britain, London W1X 4BS, England. RP Univ Oxford, Dept Phys, Clarendon Lab, Parks Rd, Oxford OX1 3PU, England. EM j.singletonl@physics.ox.ac.uk RI Mielke, Charles/S-6827-2016 OI Mielke, Charles/0000-0002-2096-5411 NR 30 TC 4 Z9 4 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4526 EI 1873-2135 J9 PHYSICA B JI Physica B PD MAY PY 1998 VL 246 BP 6 EP 11 DI 10.1016/S0921-4526(98)00017-9 PG 6 WC Physics, Condensed Matter SC Physics GA ZY829 UT WOS:000074665400003 ER PT J AU Dzurak, AS Kane, BE Clark, RG Lumpkin, NE O'Brien, JL Facer, GR Starrett, RP Skougarevsky, A Nakagawa, H Miura, N Rickel, DG Goettee, JD Campbell, LJ Fowler, CM Mielke, C King, JC Zerwekh, WD Clark, D Bartram, BD von Ortenberg, M Herlach, F Yokoi, H Bykov, AI Tatsenko, OM Platonov, VV Mitchell, EE Hermann, J Muller, KH Maranowski, KD Gossard, AC AF Dzurak, AS Kane, BE Clark, RG Lumpkin, NE O'Brien, JL Facer, GR Starrett, RP Skougarevsky, A Nakagawa, H Miura, N Rickel, DG Goettee, JD Campbell, LJ Fowler, CM Mielke, C King, JC Zerwekh, WD Clark, D Bartram, BD von Ortenberg, M Herlach, F Yokoi, H Bykov, AI Tatsenko, OM Platonov, VV Mitchell, EE Hermann, J Muller, KH Maranowski, KD Gossard, AC TI Low-temperature transport measurements of superconductors and semiconductors in magnetic fields to 800 T SO PHYSICA B-CONDENSED MATTER LA English DT Article; Proceedings Paper CT 5th International Symposium on Research in High Magnetic Fields CY AUG 04-06, 1997 CL SYDNEY, AUSTRALIA DE megagauss pulsed magnetic field; high-T(c) superconductor; parabolic quantum well AB Recent innovations in sample lithography and measurement techniques have made possible electrical transport measurements on both high-T(c) superconductor and semiconductor samples in the harsh environment of implosively generated magnetic fields B up to 800 T, with reliable data obtained up to 300 T. Thin films of the cuprate superconductor YBa(2)Cu(3)O(7-delta) have been studied with B directed parallel to the CuO planes (J parallel to B perpendicular to c-axis). At an ambient temperature of 1.6 K and a probe frequency of 0.9 GHz we find an onset of dissipation at B(on) = (150 +/- 20) T, the highest field yet reported. In addition, the measured upper critical held B(c2) = (240 +/- 30) T is significantly above the paramagnetic limit for this material. Measurements on Al(x)Ga(1-x)As/GaAs parabolic quantum well structures, designed to probe the existence of a magnetically induced triplet superconducting phase, and on HgSe:Fe samples are also discussed. (C) 1998 Elsevier Science B.V. All rights reserved. C1 Univ New S Wales, Sch Phys, Natl Pulsed Magnet Lab, Sydney, NSW 2052, Australia. Univ New S Wales, Sch Phys, Semicond Nanofabricat Facil, Sydney, NSW 2052, Australia. Univ Tokyo, Inst Solid State Phys, Tokyo 106, Japan. Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Humboldt Univ, D-10115 Berlin, Germany. Katholieke Univ Leuven, B-3001 Louvain, Belgium. Natl Res Inst Met, Tsukuba, Ibaraki 305, Japan. All Russian Res Inst Expt Phys, Arzamas 607200 16, Russia. CSIRO, Div Telecommun & Ind Phys, Epping, NSW 2121, Australia. Univ Calif Santa Barbara, Santa Barbara, CA 93106 USA. RP Dzurak, AS (reprint author), Univ New S Wales, Sch Phys, Natl Pulsed Magnet Lab, Sydney, NSW 2052, Australia. EM a.dzurak@unsw.edu.au RI Dzurak, Andrew/C-5973-2009; O'Brien, Jeremy/A-6290-2008; Goettee, Jeffrey/L-4926-2015; Mielke, Charles/S-6827-2016; OI Mielke, Charles/0000-0002-2096-5411; O'Brien, Jeremy/0000-0002-3576-8285 NR 21 TC 4 Z9 4 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4526 J9 PHYSICA B JI Physica B PD MAY PY 1998 VL 246 BP 40 EP 49 DI 10.1016/S0921-4526(98)00046-5 PG 10 WC Physics, Condensed Matter SC Physics GA ZY829 UT WOS:000074665400010 ER PT J AU Lin, CT Yan, Y Peters, K Schonherr, E Cardona, M AF Lin, CT Yan, Y Peters, K Schonherr, E Cardona, M TI Flux growth of Hg1-xRexBa2Can-1CunO2n+2+delta single crystals by self-atmosphere SO PHYSICA C LA English DT Article DE flux growth; Hg1-xRexBa2Can-1CunO2n+2+delta; Re doping; tweed structure; growth spiral; superconductivity ID SUPERCONDUCTIVITY; HGBA2CA2CU3O8+DELTA; HGBA2CACU2O6+DELTA; HGBA2CUO4+DELTA; PRESSURES AB Single crystals of Hg1-xRexBa2Can-1CunO2n+2+delta (x less than or equal to 0.25, n = 2,3) with sizes up to 3 x 2 x 0.1 mm(3) have been obtained from solution in self-atmosphere. An excess flux composition, Hg:Ba:Cu = 1:2:1, was found adequate for growing the crystals. The Re cations acted as stabilizer. They allowed the Hg to be readily incorporated into the compound at soaking temperatures as high as 1020 degrees C, resulting, however, in a Re-doped crystal. The evaporation of Hg was remarkably reduced with the increase of Re doping. The chemical composition of the crystals was determined by electron probe for microanalysis. Growth spirals and Hg-precipitates in the (001) surface were observed by means of optical polarization microscopy. X-ray diffraction studies confirmed the tetragonal structure of the crystals. Transmission electron microscopy studies provided evidence for the tweed-like tetragonal phase in the compound. Oxygenated crystals showed a T-c of 122 and 132 K for the n = 2 and 3, respectively. (C) 1998 Elsevier Science B.V. C1 Max Planck Inst Festkorperforsch, D-70569 Stuttgart, Germany. Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. RP Lin, CT (reprint author), Max Planck Inst Festkorperforsch, Heisenbergstr 1, D-70569 Stuttgart, Germany. NR 22 TC 6 Z9 6 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 MAY 1 PY 1998 VL 300 IS 1-2 BP 141 EP 150 DI 10.1016/S0921-4534(98)00055-0 PG 10 WC Physics, Applied SC Physics GA ZM550 UT WOS:000073551400021 ER PT J AU Wei, GW Althorpe, SC Zhang, DS Kouri, DJ Hoffman, DK AF Wei, GW Althorpe, SC Zhang, DS Kouri, DJ Hoffman, DK TI Lagrange-distributed approximating-functional approach to wave-packet propagation: Application to the time-independent wave-packet reactant-product decoupling method SO PHYSICAL REVIEW A LA English DT Article ID POTENTIAL-ENERGY SURFACES; STATE REACTIVE SCATTERING; REACTION PROBABILITIES; CROSS-SECTIONS; INVERSE METHOD; 6 DIMENSIONS; QUANTUM; DYNAMICS; INTERPOLATION; H-3 AB A connection is made between a recently introduced Lagrange-distributed approximating-functional and the Paley-Wiener sampling theorem. The Lagrange-distributed approximating-functional sampling is found to provide much superior results to that of Paley-Wiener sampling. The relations between discrete variable representation and Lagrange-distributed approximating functionals are discussed. The latter is used to provide an even spaced, interpolative grid representation of the Hamiltonian, in which the kinetic energy matrix has a banded, Toeplitz structure. In this paper we demonstrate that the Lagrange-distributed approximating functional representation is an accurate and reliable representation for use in fast-Fourier-transform wave-packet propagation methods and apply it to the time-independent wave-packet reactant-product decoupling method, calculating state-to-state reaction probabilities for the two-dimensional (collinear) and three-dimensional (J=0) H+H-2 reactions. The results are in very close agreement with those of previous calculations. We also discuss the connection between the distributed approximating-functional method and the existing mathematical formalism of moving least-squares theory. C1 Univ Houston, Dept Chem, Houston, TX 77204 USA. 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 Wei, GW (reprint author), Univ Houston, Dept Chem, Univ Pk, Houston, TX 77204 USA. RI Wei, Guowei /E-1852-2011 NR 65 TC 14 Z9 14 U1 0 U2 4 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1050-2947 J9 PHYS REV A JI Phys. Rev. A PD MAY PY 1998 VL 57 IS 5 BP 3309 EP 3316 DI 10.1103/PhysRevA.57.3309 PG 8 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA ZM869 UT WOS:000073584500025 ER PT J AU Knill, E Chuang, I Laflamme, R AF Knill, E Chuang, I Laflamme, R TI Effective pure states for bulk quantum computation SO PHYSICAL REVIEW A LA English DT Article AB In bulk quantum computation one can manipulate a large number of indistinguishable quantum computers by parallel unitary operations and measure expectation values of certain observables with limited sensitivity. The initial state of each computer in the ensemble is known but not pure. Methods for obtaining effective pure input states by a series of manipulations have been described by Gershenfeld and Chuang (logical labeling) [Science 275. 350 (1997)] and Cory et al. (spatial averaging) [Proc. Natl. Acad. Sci. USA 94, 1634 (1997)] for the case of quantum computation with nuclear magnetic resonance. We gives different technique called temporal averaging. This method is based on classical randomization, requires no ancilla quantum bits, and can be implemented in nuclear magnetic resonance without using gradient fields. We introduce several temporal averaging algorithms suitable for both high-temperature and low-temperature bulk quantum computing and analyze the signal-to-noise behavior of each. Most of these algorithms require only a constant multiple of the number of experiments needed by the other methods for creating effective pure stales. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87455 USA. RP Knill, E (reprint author), Univ Calif Los Alamos Natl Lab, MS B-265, Los Alamos, NM 87455 USA. NR 14 TC 177 Z9 187 U1 0 U2 4 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1050-2947 J9 PHYS REV A JI Phys. Rev. A PD MAY PY 1998 VL 57 IS 5 BP 3348 EP 3363 DI 10.1103/PhysRevA.57.3348 PG 16 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA ZM869 UT WOS:000073584500028 ER PT J AU McCurdy, CW Rescigno, TN Isaacs, WA Manolopoulos, DE AF McCurdy, CW Rescigno, TN Isaacs, WA Manolopoulos, DE TI Calculation of scattering amplitudes as continuous functions of energy: R-matrix theory without a box SO PHYSICAL REVIEW A LA English DT Article ID LIPPMANN-SCHWINGER EQUATIONS; VARIATIONAL-PRINCIPLES; SCHRODINGER AB An extension of the Kohn variational method for computing scattering amplitudes is demonstrated that requires only matrix elements of the resolvent of the Hamiltonian between energy-independent test functions. Scattering boundary conditions are imposed by expanding the resolvent in a basis of square-integrable functions and outgoing-wave continuum functions. By employing several continuum basis functions with overlaps defined by suitable analytic continuation, the scattering amplitude can be expressed efficiently over a continuous range of energies. The method described here differs from previous approaches using time-independent wave packets in that the wave packets which generate the initial and final states in this approach can lie within the interaction region. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. Univ Calif Lawrence Livermore Natl Lab, Phys & Space Technol Directorate, Livermore, CA 94550 USA. Phys & Theoret Chem Lab, Oxford OX1 3QZ, England. RP McCurdy, CW (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. NR 19 TC 6 Z9 6 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1050-2947 J9 PHYS REV A JI Phys. Rev. A PD MAY PY 1998 VL 57 IS 5 BP 3511 EP 3517 DI 10.1103/PhysRevA.57.3511 PG 7 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA ZM869 UT WOS:000073584500047 ER PT J AU Belkacem, A Sorensen, AH AF Belkacem, A Sorensen, AH TI Bound-free heavy-lepton pair production for photon and ion impact on atomic nuclei SO PHYSICAL REVIEW A LA English DT Article ID COLLISIONS; CAPTURE AB Finite nuclear size is found to cause reduction in photoproduction of mu and tau pairs with bound negative lepton. The reduction is less dramatic for muons than claimed previously but very severe for experimental production of tauonic atoms. For both types of leptons, L-shell production exceeds R-shell production in heavy targets, and light targets are more favorable for ground-state tau-atom production. Implications for heavy-ion collisions are outlined. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. Univ Aarhus, Inst Phys & Astron, DK-8000 Aarhus C, Denmark. RP Belkacem, A (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, 1 Cyclotron Rd, Berkeley, CA 94720 USA. NR 17 TC 9 Z9 9 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1050-2947 J9 PHYS REV A JI Phys. Rev. A PD MAY PY 1998 VL 57 IS 5 BP 3646 EP 3651 DI 10.1103/PhysRevA.57.3646 PG 6 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA ZM869 UT WOS:000073584500064 ER PT J AU Fishman, RS AF Fishman, RS TI Magnetic phase diagram of interfacially rough Fe/Cr multilayers SO PHYSICAL REVIEW B LA English DT Article ID DENSITY-WAVE ANTIFERROMAGNETISM; CR; SUPERLATTICES; CHROMIUM; FE(100) AB Neutron-scattering measurements have revealed that the spin-density wave (SDW) inside the Cr spacer of Fe/Cr magnetic multilayers may be either commensurate (C) or incommensurate (I) depending on the temperature and Cr thickness N. We theoretically evaluate the magnetic phase diagram of Fe/Cr multilayers under the assumption that the nodes of the SDW lie at the Cr-Fe interface, as found by recent neutron-scattering measurements. While the C phase is never stable under this assumption, the paramagnetic to I transition temperature T-N(N) takes on a seesaw pattern as the SDW wave vector switches between different allowed values. [S0163-1829(98)07717-0]. C1 Oak Ridge Natl Lab, Div Solid State, Oak Ridge, TN 37831 USA. RP Fishman, RS (reprint author), Oak Ridge Natl Lab, Div Solid State, POB 2008, Oak Ridge, TN 37831 USA. RI Fishman, Randy/C-8639-2013 NR 14 TC 10 Z9 10 U1 0 U2 1 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 EI 1550-235X J9 PHYS REV B JI Phys. Rev. B PD MAY 1 PY 1998 VL 57 IS 17 BP 10284 EP 10286 DI 10.1103/PhysRevB.57.10284 PG 3 WC Physics, Condensed Matter SC Physics GA ZL728 UT WOS:000073464500019 ER PT J AU Soderlind, P Moriarty, JA AF Soderlind, P Moriarty, JA TI First-principles theory of Ta up to 10 Mbar pressure: Structural and mechanical properties SO PHYSICAL REVIEW B LA English DT Article ID GENERALIZED GRADIENT APPROXIMATION; CUBIC TRANSITION-METALS; ELASTIC-CONSTANTS; CONSTITUTIVE MODEL; CRYSTAL-STRUCTURE; STRAIN RATE; BCC; IRON; MO; FREQUENCIES AB Fundamental high-pressure structural and mechanical properties of Ta have been investigated theoretically over a wide pressure range, 0-10 Mbar, by means of ab initio electronic-structure calculations. The calculations are fully relativistic and use a state-of-the-art treatment of gradient corrections to the exchange-correlation potential and energy within density-functional theory. The calculated zero-temperature equation of state for bcc Ta is in good agreement with diamond-anvil-cell measurements up to 750 kbar and with reduced shock data to 2.3 Mbar. The crystal-structure stability among bcc, fee, hcp, and A15 phases has been studied as a function of compression and the observed ambient-pressure bcc phase is found to be thermodynamically stable throughout the entire 0-10 Mbar range. At the upper end of this range, a metastable fee phase develops with positive elastic moduli and a decreasing fcc-bcc energy difference, suggesting that at even higher pressures above 10 Mbar, fee Ta will become stable over the bcc phase. Elastic constants, the H- and N-point zone-boundary phonons, and the ideal shear strength have also been calculated for bcc Ta up to 10 Mbar pressure. The elastic moduli and phonons are in good agreement with experiment at ambient pressure and remain real and positive for all compressions studied, demonstrating that the bcc phase is mechanically stable in this regime. The calculated elastic constants validate the assumed pressure scaling of the shear modulus in the Steinberg-Guinan strength model of Ta, while the calculated values of ideal shear strength provide an upper bound to the high-pressure yield stress. [S0163-1829(98)01117-5]. C1 Lawrence Livermore Natl Lab, Phys & Space Technol Directorate, Livermore, CA 94551 USA. RP Lawrence Livermore Natl Lab, Phys & Space Technol Directorate, POB 808, Livermore, CA 94551 USA. NR 49 TC 101 Z9 101 U1 0 U2 15 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 2469-9950 EI 2469-9969 J9 PHYS REV B JI Phys. Rev. B PD MAY 1 PY 1998 VL 57 IS 17 BP 10340 EP 10350 DI 10.1103/PhysRevB.57.10340 PG 11 WC Physics, Condensed Matter SC Physics GA ZL728 UT WOS:000073464500034 ER PT J AU Yoo, CS Cynn, H Soderlind, P AF Yoo, CS Cynn, H Soderlind, P TI Phase diagram of uranium at high pressures and temperatures SO PHYSICAL REVIEW B LA English DT Article ID METALS; IRON AB The phase diagram of uranium has been studied to 100 GPa by in situ diamond-anvil cell x-ray/laser-heating experiments. The gamma (bcc) phase is discovered at high pressures, and the melting curve is presented to 100 GPa, The gamma phase, B=113.3 Cpa, is approximately 20% softer than the a(orthorhombic), B=135.5 GPa. The volume change in the alpha/gamma transition shows a strong pressure dependence, ranging from 6% at ambient pressure to less than 1% at 80 Gpa. Free-energy calculations, using Debye-Gruneisen quasiharmonic theory, show that the softer bulk modulus of the gamma phase, compared to the alpha phase, stabilizes the gamma phase at high temperatures. [S0163-1829(98)10817-2]. C1 Univ Calif Lawrence Livermore Natl Lab, Phys & Space Technol Directorate, Div H, Livermore, CA 94551 USA. RP Yoo, CS (reprint author), Univ Calif Lawrence Livermore Natl Lab, Phys & Space Technol Directorate, Div H, Livermore, CA 94551 USA. NR 19 TC 64 Z9 66 U1 0 U2 15 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 EI 1550-235X J9 PHYS REV B JI Phys. Rev. B PD MAY 1 PY 1998 VL 57 IS 17 BP 10359 EP 10362 DI 10.1103/PhysRevB.57.10359 PG 4 WC Physics, Condensed Matter SC Physics GA ZL728 UT WOS:000073464500036 ER PT J AU Heaney, PJ Mehta, A Sarosi, G Lamberti, VE Navrotsky, A AF Heaney, PJ Mehta, A Sarosi, G Lamberti, VE Navrotsky, A TI Structural effects of Sr substitution in La2-xSrxNiO4+delta SO PHYSICAL REVIEW B LA English DT Article ID MAGNETIC CORRELATIONS; CRYSTAL-CHEMISTRY; OXYGEN-CONTENT; COPPER OXIDES; LA1.8SR0.2NIO4; CHARGE; SUPERCONDUCTIVITY; LA2NIO4+DELTA; DIFFRACTION; PHASE AB Structures within the La2-xSrxNiO4+delta system (0 < x less than or equal to 1) were refined by Rietveld analysis of powder x-ray-diffraction data. Our results reveal three distinct regimes that parallel energetic transformations within the series. For 0 less than or equal to x < 0.2, enthalpies of oxidation are strongly exothermic and the compounds are monophasic and orthorhombic. Hole saturation occurs for 0.2 < x < 0.6, and the symmetry decreases from orthorhumbic to monoclinic. For 0.6 < x < 1.0, diffraction patterns suggest phase immiscibility between a Sr-poor, hole-saturated compound and a Sr-rich phase for which oxidation is strongly favored. Fourier synthesis maps for all compositions revealed evidence for microtwinning and positional disorder among apical oxygen atoms. [S0163-1829(98)06118-9]. C1 Princeton Univ, Princeton mat Inst, Princeton, NJ 08544 USA. Princeton Univ, Dept Geosci, Princeton, NJ 08544 USA. Stanford Linear Accelerator Ctr, Stanford Synchrotron Radiat Lab, Stanford, CA 94309 USA. RP Heaney, PJ (reprint author), Princeton Univ, Princeton mat Inst, Princeton, NJ 08544 USA. NR 28 TC 13 Z9 13 U1 4 U2 12 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 EI 1550-235X J9 PHYS REV B JI Phys. Rev. B PD MAY 1 PY 1998 VL 57 IS 17 BP 10370 EP 10378 DI 10.1103/PhysRevB.57.10370 PG 9 WC Physics, Condensed Matter SC Physics GA ZL728 UT WOS:000073464500038 ER PT J AU Booth, CH Bridges, F Kwei, GH Lawrence, JM Cornelius, AL Neumeier, JJ AF Booth, CH Bridges, F Kwei, GH Lawrence, JM Cornelius, AL Neumeier, JJ TI Lattice effects in La1-xCaxMnO3 (x=0 -> 1): Relationships between distortions, charge distribution, and magnetism SO PHYSICAL REVIEW B LA English DT Article ID COLOSSAL-MAGNETORESISTANCE; X-RAY; PHASE-TRANSITION; DEFECT CHEMISTRY; DOUBLE EXCHANGE; DOPED LAMNO3; FILMS; LA(1-X)A(X)MNO(3); LAMNO3+/-DELTA; LA1-XSRXMNO3 AB X-ray-absorption fine-structure measurements from the Mn and La K edges of samples of La1-xCaxMnO3 (x = 0-->1) are presented as a function of temperature. In the insulating state, distortions of the Mn-O environment are found to be linear with calcium concentration x. These distortions are consistent with a model where individual Mn3+ sites have strong Jahn-Teller (JT) distortions while Mn4+ sites do not, although intermediate distortions are also possible. Comparisons to simulations of various possible bond length distributions show that these distortions are best modeled as a JT distortion, as opposed to charge disproportionation or other models. In the metallic state, at least similar to 70% of the distortion is removed. A similar effect is seen in the Mn-Mn bond length distribution. The La-O bond length distribution does not change significantly through the ferromagnetic transition, constraining possible changes in the Mn-O-Mn bond angle to less than 0.5 degrees, The changes in the MnO6 distortion that occur near T-c are also present (to a lesser degree) in an insulating sample with x = 0.12. The functional relation between the MnO6 distortions and the magnetization is determined, and compared to transport measurements. [S0163-1829(98)04917-0]. C1 University California Irvine, Dept Phys & Astron, Irvine, CA 92697 USA. Univ Calif Santa Cruz, Dept Phys, Santa Cruz, CA 95064 USA. Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Florida Atlantic Univ, Dept Phys, Boca Raton, FL 33431 USA. RP University California Irvine, Dept Phys & Astron, Irvine, CA 92697 USA. RI Cornelius, Andrew/A-9837-2008; Booth, Corwin/A-7877-2008 NR 49 TC 133 Z9 133 U1 5 U2 22 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 2469-9950 EI 2469-9969 J9 PHYS REV B JI Phys. Rev. B PD MAY 1 PY 1998 VL 57 IS 17 BP 10440 EP 10454 DI 10.1103/PhysRevB.57.10440 PG 15 WC Physics, Condensed Matter SC Physics GA ZL728 UT WOS:000073464500048 ER PT J AU Scherrer, P Dimitropoulos, C Borsa, F Rubini, S AF Scherrer, P Dimitropoulos, C Borsa, F Rubini, S TI NMR study of ordering kinetics in Ni3Al alloys SO PHYSICAL REVIEW B LA English DT Article ID TRANSFORMATION AB Al-27 nuclear magnetic resonance (NMR) and relaxation has been applied to the study of the effects of ball milling on the long-range order (LRO) of fee L1(2) Ni3Al as well as to the subsequent microscopic reordering process through annealing. Structural changes due to the mechanical treatment are correlated to the appearance of a strong magnetization in the disordered phase. In the absence of significant Fe contamination, this magnetic property is attributed to the existence of magnetic moments of the order of 0.23 mu(B) (mu(B) = Bohr magneton) localized at the Ni sites. Al-27 NMR spectra in both the ordered and the disordered phase are presented. The random distribution of atoms combined with the magnetic properties in the disordered phase cause a substantial broadening of the Al-27 NM line. The linewidth is proportional to the fractional change of disorder and is therefore used to monitor the ordering transformation as a function of annealing time and temperature. The changes of spin-lattice relaxation rates (T-1(-1)) and Knight shifts during transformation are also examined. The overall ordering behavior as observed by NMR is described in terms of a stretched exponential for the time dependence of the untransformed fraction, implying a time-dependent transformation rate. The activation energy of the Ni vacancy migration mechanism responsible for the transformation was determined to be E = 1.8 eV +/- 0.2 eV. The average distance covered by the atoms during the ordering is estimated by means of a simple random-walk model. [S0163-1829(98)09317-5]. C1 Ecole Polytech Fed Lausanne, Inst Phys Expt, CH-1015 Lausanne, Switzerland. Univ Pavia, Dipartimento Fis A Volta, I-27100 Pavia, Italy. Univ Pavia, INFM, I-27100 Pavia, Italy. Iowa State Univ Sci & Technol, Ames Lab, Ames, IA 50011 USA. Iowa State Univ Sci & Technol, Dept Phys, Ames, IA 50011 USA. RP Scherrer, P (reprint author), Ecole Polytech Fed Lausanne, Inst Phys Expt, CH-1015 Lausanne, Switzerland. RI Rubini, Silvia/C-8369-2012 OI Rubini, Silvia/0000-0001-5215-2223 NR 23 TC 12 Z9 12 U1 1 U2 1 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 EI 1550-235X J9 PHYS REV B JI Phys. Rev. B PD MAY 1 PY 1998 VL 57 IS 17 BP 10462 EP 10469 DI 10.1103/PhysRevB.57.10462 PG 8 WC Physics, Condensed Matter SC Physics GA ZL728 UT WOS:000073464500050 ER PT J AU Price, DL Saboungi, ML Badyal, YS Wang, J Moss, SC Leheny, RL AF Price, DL Saboungi, ML Badyal, YS Wang, J Moss, SC Leheny, RL TI Structure of molten iron chloride: Neutron scattering and modeling SO PHYSICAL REVIEW B LA English DT Article ID LIQUID AB Neutron-diffraction measurements of molten FeCl3, combined with model calculations and computer simulations, show that on melting the local structure of Fe changes from an octahedral to a tetrahedral environment. A similar change is observed in AlCl3, in contrast to YCl3, for example, where the octahedral coordination of Y is preserved on melting. The local structure of the liquid can be described in terms of Fe2Cl6 molecular units, similar to those observed in the vapor phase but with strong intermolecular interactions. Detailed information about the orientational correlations between molecules is derived from the simulations and compared with recent results on another molecular liquid, propylene glycol. [S0163-1829(98)05417-4]. . C1 Argonne Natl Lab, Argonne, IL 60439 USA. Univ Houston, Houston, TX 77204 USA. Univ Chicago, Chicago, IL 60637 USA. RP Price, DL (reprint author), Argonne Natl Lab, 9700 S Cass Ave, 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 28 TC 18 Z9 18 U1 0 U2 3 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 EI 1550-235X J9 PHYS REV B JI Phys. Rev. B PD MAY 1 PY 1998 VL 57 IS 17 BP 10496 EP 10503 DI 10.1103/PhysRevB.57.10496 PG 8 WC Physics, Condensed Matter SC Physics GA ZL728 UT WOS:000073464500054 ER PT J AU Nipko, JC Loong, CK AF Nipko, JC Loong, CK TI Phonon excitations and related thermal properties of aluminum nitride SO PHYSICAL REVIEW B LA English DT Article ID ELECTRONIC-STRUCTURE; RAMAN-SCATTERING; CRYSTALS; ALN; CONDUCTIVITY; AIN; SEMICONDUCTORS AB The phonon density of states of aluminum nitride was determined by time-of-flight neutron spectroscopy using a polycrystalline sample. The observed phonon excitation spectrum consists of a broadband centered at about 35 meV, a small gap in the 75-80 meV region, and two sharp bands at approximately 85 and 92 meV. A rigid-ion model was applied to the interpretation of the data. After optimization, the model provided a satisfactory description of the neutron results as well as the Raman and IR data, sound-velocity measurements, and the lattice specific heat reported in the literature. The partial and total DOS and the phonon-dispersion curves along major symmetry directions of the Brillouin zone were calculated, and the contribution of phonons to the Debye behavior of the low-temperature thermal conductivity was discussed. [S0163-1829(98)00618-3]. C1 Argonne Natl Lab, Div Intense Pulsed Neutron Source, Argonne, IL 60439 USA. RP Nipko, JC (reprint author), Argonne Natl Lab, Div Intense Pulsed Neutron Source, Argonne, IL 60439 USA. NR 58 TC 60 Z9 60 U1 1 U2 14 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 EI 1550-235X J9 PHYS REV B JI Phys. Rev. B PD MAY 1 PY 1998 VL 57 IS 17 BP 10550 EP 10554 DI 10.1103/PhysRevB.57.10550 PG 5 WC Physics, Condensed Matter SC Physics GA ZL728 UT WOS:000073464500060 ER PT J AU McQueeney, RJ AF McQueeney, RJ TI Dynamic radial distribution function from inelastic neutron scattering SO PHYSICAL REVIEW B LA English DT Article ID AMORPHOUS SOLIDS; SUPERCONDUCTORS AB A real-space, local dynamic structure function g(tau,omega) is defined from the dynamic structure function S(Q,omega), which can be measured using inelastic neutron scattering. At any particular frequency omega, S(Q,omega) contains e-dependent intensity oscillations which reflect the spatial distribution and relative displacement directions for the atoms vibrating at that frequency. Information about local and dynamic atomic correlations is obtained from the Fourier transform of these oscillations g(tau,omega) at the particular frequency, g(tau,omega) can be formulated such that the elastic and frequency-summed limits correspond to the average and instantaneous radial distribution function, respectively, and is thus called the dynamic radial distribution function. As an example, the dynamic radial distribution function is calculated for fee nickel in a model which considers only the harmonic atomic displacements due to phonons. The results of these calculations demonstrate that the magnitude of the atomic correlations can be quantified and g(tau, omega) is a well-defined correlation function. This leads to a simple prescription for investigating local lattice dynamics. [S0163-1829(98)00817-0]. C1 Los Alamos Natl Lab, Los Alamos Neutron Sci Ctr, Lujan Ctr, Los Alamos, NM 87545 USA. RP Los Alamos Natl Lab, Los Alamos Neutron Sci Ctr, Lujan Ctr, POB 1663, Los Alamos, NM 87545 USA. OI McQueeney, Robert/0000-0003-0718-5602 NR 18 TC 10 Z9 10 U1 0 U2 2 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 2469-9950 EI 2469-9969 J9 PHYS REV B JI Phys. Rev. B PD MAY 1 PY 1998 VL 57 IS 17 BP 10560 EP 10568 DI 10.1103/PhysRevB.57.10560 PG 9 WC Physics, Condensed Matter SC Physics GA ZL728 UT WOS:000073464500062 ER PT J AU Cox, DE Iglesias, T Hirota, K Shirane, G Matsuda, M Motoyama, N Eisaki, H Uchida, S AF Cox, DE Iglesias, T Hirota, K Shirane, G Matsuda, M Motoyama, N Eisaki, H Uchida, S TI Low-temperature charge ordering in Sr14Cu24O41 SO PHYSICAL REVIEW B LA English DT Article ID SPIN-1/2 LADDER SYSTEM; NEUTRON-SCATTERING; STATE; CHAINS; GAP AB Synchrotron x-ray measurements were made between 20-300 K on single crystals of Sr14Cu24O41 which has a quasi-one-dimensional chain and ladder structure, in order to investigate possible charge-ordering effects in the CuO2 chains as indicated by recent NMR studies. At 50 K a few very weak satellite peaks were observed at (00l) positions corresponding to a fourfold increase in periodicity along the chain axis. These peaks decreased in intensity with increasing temperature, and eventually disappeared close to 300 K. The observations were interpreted in terms of a charge-ordered model involving both dimerization between two next-nearest-neighbor Cu2+ ions surrounding a Cu3+ ion on a Zhang-Rice singlet site, and dimerization between nearest-neighbor Cu2+ ions. [S0163-1829(98)06617-X]. C1 Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. RIKEN, Inst Phys & Chem Res, Wako, Saitama 35101, Japan. Univ Tokyo, Dept Supercond, Bunkyo Ku, Tokyo 113, Japan. Tohoku Univ, Dept Phys, Sendai, Miyagi 98077, Japan. RP Cox, DE (reprint author), Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. RI Hirota, Kazuma/C-6797-2008; Matsuda, Masaaki/A-6902-2016 OI Matsuda, Masaaki/0000-0003-2209-9526 NR 22 TC 42 Z9 43 U1 0 U2 2 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 EI 1550-235X J9 PHYS REV B JI Phys. Rev. B PD MAY 1 PY 1998 VL 57 IS 17 BP 10750 EP 10754 DI 10.1103/PhysRevB.57.10750 PG 5 WC Physics, Condensed Matter SC Physics GA ZL728 UT WOS:000073464500089 ER PT J AU Bill, A Kresin, VZ Wolf, SA AF Bill, A Kresin, VZ Wolf, SA TI Isotope effect for the penetration depth in superconductors SO PHYSICAL REVIEW B LA English DT Article ID NORMAL-STATE; TRANSITION-TEMPERATURE; EFFECTIVE-MASS; PAIR BREAKING; APEX-OXYGEN; LA2-XSRXCUO4; YBA2CU3O7; CARRIERS AB We show that various factors can lead to an isotopic dependence of the penetration depth delta. Nonadiabaticity (Jahn-Teller crossing) leads to the isotope effect of the charge-carrier concentration n and, consequently, of delta in doped superconductors such as the cuprates. A general equation relating the isotope coefficients of T-c and of delta is presented for London superconductors. We further show that the presence of magnetic impurities or a proximity contact also lead to an isotopic dependence of delta; the isotope coefficient turns out to be temperature dependent, beta(T), in these cases. The existence of the isotope effect for the penetration depth is predicted for conventional as well as for high-temperature superconductors. Various experiments are proposed and/or discussed. [S0163-1829(98)03617-0]. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. USN, Res Lab, Washington, DC 20375 USA. RP Bill, A (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RI Wolf, Stuart/A-7513-2009 NR 53 TC 19 Z9 19 U1 0 U2 1 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 EI 1550-235X J9 PHYS REV B JI Phys. Rev. B PD MAY 1 PY 1998 VL 57 IS 17 BP 10814 EP 10824 DI 10.1103/PhysRevB.57.10814 PG 11 WC Physics, Condensed Matter SC Physics GA ZL728 UT WOS:000073464500096 ER PT J AU Williams, RK Scarbrough, JO Schmitz, JM Thompson, JR AF Williams, RK Scarbrough, JO Schmitz, JM Thompson, JR TI Thermal conductivity of polycrystalline YBa2Cu4O8 from 10 to 300 K SO PHYSICAL REVIEW B LA English DT Article ID HIGH-TEMPERATURE SUPERCONDUCTORS; T-C SUPERCONDUCTORS; SINGLE-CRYSTALS; THIN-FILMS; YBA2CU3O7-DELTA; HEAT; YBA2CU3O6.95; DEPENDENCE; LATTICE; PHASE AB The thermal conductivity lambda and electrical resistivity rho were measured on two samples of the cuprate superconductor YBa2Cu4O8 (Y124). The lambda results pass through a maximum at about half of the superconducting transition temperature T-c. The peak lambda value is much higher than the peak value for polycrystalline YBa2Cu3O7-delta, Y123, and is about equal to ab plane values for good melt processed Y123. In the normal state most of the lambda is due to phonon transport lambda(p) and estimates of lambda(p) were obtained from the data by making a correction for electronic transport. Phonon-phonon and phonon-electron scattering limit the hp of both Y124 and Y123. In the two compounds, the phonon-phonon scattering is about equally strong, but electron-phonon scattering is considerably weaker in Y124. In the superconducting state, below the lambda maximum at T-c/2, lambda varies as T-n(n approximate to 1/2). This behavior has also been observed in Y123, but is not consistent with phonon scattering theory. The implications of this observation are discussed. [S0163-1829(98)08117-X]. C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. Univ Tennessee, Dept Phys, Knoxville, TN 37996 USA. RP Williams, RK (reprint author), Oak Ridge Natl Lab, POB 2008, Oak Ridge, TN 37831 USA. NR 56 TC 8 Z9 8 U1 1 U2 5 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 EI 1550-235X J9 PHYS REV B JI Phys. Rev. B PD MAY 1 PY 1998 VL 57 IS 17 BP 10923 EP 10928 DI 10.1103/PhysRevB.57.10923 PG 6 WC Physics, Condensed Matter SC Physics GA ZL728 UT WOS:000073464500107 ER PT J AU Mendoza, CI Barrera, RG Fuchs, R AF Mendoza, CI Barrera, RG Fuchs, R TI Energy loss of electrons traveling parallel to the interface of a semi-infinite granular composite SO PHYSICAL REVIEW B LA English DT Article ID VALENCE LOSS SPECTRA; MEDIA; DISPERSION; SPHERES AB The energy loss of an electron traveling above a semi-infinite granular composite consisting of randomly located spherical inclusions is investigated. We express this loss in terms of a surface response function which is then calculated using an effective medium theory for the bulk dielectric function of the system. Three different models are analyzed. The first two models correspond to local and nonlocal versions of a truncated bulk, and the third one includes the effects of the distribution of the spherical inclusions near the surface. We find that a correct treatment of this distribution is necessary in order to get meaningful results. C1 Univ Nacl Autonoma Mexico, Inst Fis, Mexico City 01000, DF, Mexico. Iowa State Univ, Ames Lab, Ames, IA 50011 USA. Iowa State Univ, Dept Phys & Astron, Ames, IA 50011 USA. RP Univ Nacl Autonoma Mexico, Inst Fis, Apartado Postal 20364, Mexico City 01000, DF, Mexico. NR 13 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 2469-9950 EI 2469-9969 J9 PHYS REV B JI Phys. Rev. B PD MAY 1 PY 1998 VL 57 IS 18 BP 11193 EP 11203 DI 10.1103/PhysRevB.57.11193 PG 11 WC Physics, Condensed Matter SC Physics GA ZM876 UT WOS:000073585200034 ER PT J AU Asta, M Foiles, SM Quong, AA AF Asta, M Foiles, SM Quong, AA TI First-principles calculations of bulk and interfacial thermodynamic properties for fcc-based Al-Sc alloys SO PHYSICAL REVIEW B LA English DT Article ID ELECTRONIC-STRUCTURE; PSEUDOPOTENTIALS; SYSTEMS; KINETICS; AL3SC AB The configurational thermodynamic properties of fee-based AI-Se alloys and coherent Al/Al3Se interphase-boundary interfaces have been calculated from first principles. The computational approach used in this study combines the results of pseudopotential total-energy calculations with a cluster-expansion description of the alloy energetics. Bulk and interface configurational-thermodynamic properties are computed using a low-temperature-expansion technique. Calculated values of the {100} and {111} Al/Al3Se interfacial energies at zero temperature are, respectively, 192 and 226 mJ/m(2). The temperature dependence of the calculated interfacial free energies is found to be very weak for {100} and more appreciable for {111} orientations; the primary effect of configurational disordering at finite temperature is to reduce the degree of crystallographic anisotropy associated with calculated interfacial free energies. The first-principles-computed solid-solubility limits for Sc in bulk fee Al are found to be underestimated significantly in comparison with experimental measurements. It is argued that this discrepancy can be largely attributed to nonconfigurational contributions to the entropy which have been neglected in the present thermodynamic calculations. C1 Sandia Natl Labs, Computat Mat Sci Div, Livermore, CA 94551 USA. RP Sandia Natl Labs, Computat Mat Sci Div, POB 969,MS 9161, Livermore, CA 94551 USA. OI Foiles, Stephen/0000-0002-1907-454X NR 44 TC 61 Z9 64 U1 2 U2 12 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 2469-9950 EI 2469-9969 J9 PHYS REV B JI Phys. Rev. B PD MAY 1 PY 1998 VL 57 IS 18 BP 11265 EP 11275 DI 10.1103/PhysRevB.57.11265 PG 11 WC Physics, Condensed Matter SC Physics GA ZM876 UT WOS:000073585200042 ER PT J AU Matsuda, M Kojima, KM Uemura, YJ Zarestky, JL Nakajima, K Kakurai, K Yokoo, T Shapiro, SM Shirane, G AF Matsuda, M Kojima, KM Uemura, YJ Zarestky, JL Nakajima, K Kakurai, K Yokoo, T Shapiro, SM Shirane, G TI Ordering of oxygen moments in ferromagnetic edge-sharing CuO4 chains in La14-xCaxCu24O41 SO PHYSICAL REVIEW B LA English DT Article ID NEUTRON-SCATTERING; SUSCEPTIBILITY; LADDERS; SYSTEM; STATE AB Neutron scattering measurements have been performed on the S=1/2 quasi-one-dimensional system La5Ca9Cu24O41, which consists of edge-sharing CuO4 chains. We observed that the chains shaw an antiferromagnetic long-range ordering below T-N=10.5 K with ferromagnetic correlations within the chain. In the antiferromagnetically ordered phase, an ordering of oxygen moments (similar to 0.02 mu(B)) as well as that of Cu moments (similar to 0.2 mu(B)) is observed. The oxygen moments are coupled with Cu moments ferromagnetically. C1 RIKEN, Inst Phys & Chem Res, Wako, Saitama 35101, Japan. Columbia Univ, Dept Phys, New York, NY 10027 USA. Ames Lab, Ames, IA 50011 USA. Univ Tokyo, ISSP, Neutron Scattering Lab, Tokai, Ibaraki 31911, Japan. Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. Aoyama Gakuin Univ, Dept Phys, Setagaya Ku, Tokyo 157, Japan. RP RIKEN, Inst Phys & Chem Res, Wako, Saitama 35101, Japan. RI Matsuda, Masaaki/A-6902-2016 OI Matsuda, Masaaki/0000-0003-2209-9526 NR 22 TC 32 Z9 32 U1 0 U2 2 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 2469-9950 EI 2469-9969 J9 PHYS REV B JI Phys. Rev. B PD MAY 1 PY 1998 VL 57 IS 18 BP 11467 EP 11471 DI 10.1103/PhysRevB.57.11467 PG 5 WC Physics, Condensed Matter SC Physics GA ZM876 UT WOS:000073585200058 ER PT J AU Martindale, JA Hammel, PC Hults, WL Smith, JL AF Martindale, JA Hammel, PC Hults, WL Smith, JL TI Temperature dependence of the anisotropy of the planar oxygen nuclear spin-lattice relaxation rate in YBa2Cu3Oy SO PHYSICAL REVIEW B LA English DT Article ID NEUTRON-SCATTERING EXPERIMENTS; FERMI-LIQUID THEORY; MAGNETIC-RESONANCE; SUPERCONDUCTING STATE; NMR EXPERIMENTS; SINGLE-CRYSTAL; O-17; SITES; MODEL; LA1.85SR0.15CUO4 AB We report measurements of the full planar O-17 nuclear spin-lattice relaxation rate tensor in optimally and underdoped YBa2Cu3Oy (y=6.96 and 6.63). The anisotropy varies strongly with temperature in both samples: for the y = 6.63 sample, the ratio of the relaxation rate measured with the applied field in the ab plane and oriented parallel to the copper-oxygen bond axis to that measured with the applied field in the ab plane and oriented perpendicular to the bond axis changes by over 25% from room temperature to T-c. The consequences of these results for theoretical models are discussed. They suggest that a second spin degree of freedom independent of the Cu(3d(x2-y2))-O(2p sigma) band exists in the CuO2 planes of YBa2Cu3Oy. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Ohio State Univ, Dept Phys, 174 W 18Th Ave, Columbus, OH 43210 USA. RI Hammel, P Chris/O-4845-2014 OI Hammel, P Chris/0000-0002-4138-4798 NR 35 TC 18 Z9 18 U1 0 U2 2 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 2469-9950 EI 2469-9969 J9 PHYS REV B JI Phys. Rev. B PD MAY 1 PY 1998 VL 57 IS 18 BP 11769 EP 11774 DI 10.1103/PhysRevB.57.11769 PG 6 WC Physics, Condensed Matter SC Physics GA ZM876 UT WOS:000073585200094 ER PT J AU Islam, Z Fisher, IR Zarestky, J Canfield, PC Stassis, C Goldman, AI AF Islam, Z Fisher, IR Zarestky, J Canfield, PC Stassis, C Goldman, AI TI Reinvestigation of long-range magnetic ordering in icosahedral Tb-Mg-Zn SO PHYSICAL REVIEW B LA English DT Article ID SPIN-GLASS BEHAVIOR; QUASI-CRYSTALS AB We present results of a study of possible magnetic ordering in the icosahedral phase of Tb-Mg-Zn probed by bulk magnetization measurements and neutron diffraction. Measurements on both crushed single grains and cast polycrystalline samples of To-Mg-Zn were performed. Magnetization measurements on both samples reveal only a spin-glass-like transition at approximately 5.8 g. Neutron diffraction from the crushed single grains reveals only short-range magnetic ordering at low temperatures, with no evidence of the long-range magnetic ordering reported previously [Charrier, Ouladdiaf, and Schmitt Phys. Rev. Lett. 78, 4637 (1997)]. Likewise, the cast polycrystalline samples exhibit primarily diffuse magnetic scattering at low temperature, but at least one relatively sharp diffraction peak was observed. Our results indicate that for single grain samples there is no long-range magnetic ordering and that, at best, the magnetic ordering in these quasicrystalline alloys is not very robust. C1 US DOE, Ames Lab, Ames, IA 50011 USA. Iowa State Univ Sci & Technol, Dept Phys & Astron, Ames, IA 50011 USA. RP US DOE, Ames Lab, Ames, IA 50011 USA. RI Canfield, Paul/H-2698-2014 NR 12 TC 5 Z9 5 U1 0 U2 1 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 2469-9950 EI 2469-9969 J9 PHYS REV B JI Phys. Rev. B PD MAY 1 PY 1998 VL 57 IS 18 BP R11047 EP R11050 DI 10.1103/PhysRevB.57.R11047 PG 4 WC Physics, Condensed Matter SC Physics GA ZM876 UT WOS:000073585200008 ER PT J AU Norman, MR Randeira, M Ding, H Campuzano, JC AF Norman, MR Randeira, M Ding, H Campuzano, JC TI Phenomenology of the low-energy spectral function in high-T-c superconductors SO PHYSICAL REVIEW B LA English DT Article ID ANGLE-RESOLVED PHOTOEMISSION; NORMAL-STATE; GAP; BI2SR2CACU2O8+DELTA; PSEUDOGAP AB We introduce a simple phenomenological form for the self-energy which allows us to extract important information from angle-resolved photoemission data on the high-T-c superconductor Bi2Sr2CaCu2O8 for binding energies of order the spectral gap. First, we find a rapid suppression of the single particle scattering rate below T-c for all doping levels. Second, we find that in the overdoped materials the gap Delta at all k points on the Fermi surface has significant temperature dependence and vanishes near T-c. In contrast, in the underdoped samples such behavior is found only at k points close to the diagonal. Near (pi,0), Delta is essentially T independent in the underdoped samples. The filling-in of the pseudogap with increasing T is described by a broadening proportional to T-T-c, which is naturally explained by pairing correlations above T-c. C1 Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. Tata Inst Fundamental Res, Mumbai 400005, India. Univ Illinois, Dept Phys, Chicago, IL 60607 USA. RP Argonne Natl Lab, Div Mat Sci, 9700 S Cass Ave, Argonne, IL 60439 USA. RI Norman, Michael/C-3644-2013; Campuzano, Juan Carlos/G-4358-2012 NR 23 TC 39 Z9 40 U1 4 U2 10 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 2469-9950 EI 2469-9969 J9 PHYS REV B JI Phys. Rev. B PD MAY 1 PY 1998 VL 57 IS 18 BP R11093 EP R11096 DI 10.1103/PhysRevB.57.R11093 PG 4 WC Physics, Condensed Matter SC Physics GA ZM876 UT WOS:000073585200020 ER PT J AU Norman, MR Ding, H AF Norman, MR Ding, H TI Collective modes and the superconducting-state spectral function of Bi2Sr2CaCu2O8 SO PHYSICAL REVIEW B LA English DT Article ID NEUTRON-SCATTERING; TUNNELING SPECTROSCOPY; PHOTOEMISSION; EXCITATIONS; YBA2CU3O6+X; BILAYER AB Photoemission spectra of the high-temperature superconductor Bi2Sr2CaCu2O8 near (pi,0) show a dramatic change when cooling below T-c: the broad peak. in the normal state turns into a sharp low-energy peak followed by a higher binding-energy hump. Recent experiments fmd that this row-energy peak persists over a significant range in momentum space. We show in this paper that these data are well described by a simple model of electrons interacting with a collective mode that appears only below T-c. C1 Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. Univ Illinois, Dept Phys, Chicago, IL 60607 USA. RP Argonne Natl Lab, Div Mat Sci, 9700 S Cass Ave, Argonne, IL 60439 USA. RI Norman, Michael/C-3644-2013 NR 25 TC 32 Z9 33 U1 1 U2 1 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 2469-9950 EI 2469-9969 J9 PHYS REV B JI Phys. Rev. B PD MAY 1 PY 1998 VL 57 IS 18 BP R11089 EP R11092 DI 10.1103/PhysRevB.57.R11089 PG 4 WC Physics, Condensed Matter SC Physics GA ZM876 UT WOS:000073585200019 ER PT J AU Gueye, P Bernheim, M Danel, JF Ducret, JE Lakehal-Ayat, L Le Goff, JM Magnon, A Marchand, C Morgenstern, J Marroncle, J Vernin, P Zghiche-Lakehal-Ayat, A Breton, V Frullani, S Garibaldi, F Ghio, F Jodice, M Isabelle, DB Meziani, ZE Offermann, E Traini, M AF Gueye, P Bernheim, M Danel, JF Ducret, JE Lakehal-Ayat, L Le Goff, JM Magnon, A Marchand, C Morgenstern, J Marroncle, J Vernin, P Zghiche-Lakehal-Ayat, A Breton, V Frullani, S Garibaldi, F Ghio, F Jodice, M Isabelle, DB Meziani, ZE Offermann, E Traini, M TI Dispersive effects from a comparison of electron and positron scattering from C-12 SO PHYSICAL REVIEW C LA English DT Article ID ENERGY-DEPENDENCE AB Dispersive effects have been investigated by comparing elastic scattering of electrons and positrons from C-12 at the Saclay Linear Accelerator. The results demonstrate that dispersive effects at energies of 262 MeV and 450 MeV are less than 2% below the first diffraction minimum [0.95 threshold previously suggested to explain the anomalous features observed in timelike G(M)(p) LEAR and G(E)(n) FENICE data. [S0556-2813(98)04905-X]. C1 Thomas Jefferson Natl Accelerator Facil, Newport News, VA 23606 USA. Hampton Univ, Dept Phys, Hampton, VA 23668 USA. Kettering Fairmont High Sch, Kettering, OH 45429 USA. RP Williams, RA (reprint author), Thomas Jefferson Natl Accelerator Facil, 12000 Jefferson Ave, Newport News, VA 23606 USA. EM bobw@cebaf.gov; ben2@bigfoot.com NR 50 TC 0 Z9 0 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2813 J9 PHYS REV C JI Phys. Rev. C PD MAY PY 1998 VL 57 IS 5 BP 2605 EP 2617 DI 10.1103/PhysRevC.57.2605 PG 13 WC Physics, Nuclear SC Physics GA ZP516 UT WOS:000073761300061 ER PT J AU Utku, S Ross, JG Bateman, NPT Bardayan, DW Chen, AA Gorres, J Howard, AJ Iliadis, C Parker, PD Smith, MS Vogelaar, RB Wiescher, M Yildiz, K AF Utku, S Ross, JG Bateman, NPT Bardayan, DW Chen, AA Gorres, J Howard, AJ Iliadis, C Parker, PD Smith, MS Vogelaar, RB Wiescher, M Yildiz, K TI Breakout from the hot CNO cycle: The F-18(p,gamma) vs F-18(p,alpha) branching ratio SO PHYSICAL REVIEW C LA English DT Article ID REACTION-RATES; STRENGTHS; ENERGIES; NE-18; ALPHA AB We have studied the properties of low-lying F-18+p resonances as excited states in Ne-19. Three new levels have been found in the range 0 less than or equal to E(c.m.)less than or equal to 1 MeV just above the F-18+p threshold, and partial decay widths and isospin-mirror connections are suggested to known states in F-19 for each of the nine states in this energy range. The properties of these resonances have been used to calculate the reaction rate N-A(sigma v) for the F-18(p,gamma)Ne-19 and F-18(p,alpha)O-15 reactions in the temperature range 10(8) pairs, we have searched for the color-suppressed B hadronic decay processes (B) over bar(0)-->D-0(D*(0))X-0, where X-0 is a light neutral meson pi(0), rho(0), eta, eta' or omega. The D-*0 mesons are reconstructed in D-*0-->D-0 pi(0) and the D-0 mesons in D-0-->K- pi(+), K(-)pi(+)pi(0) and K(-)pi(+)pi(+)pi(-) decay modes. No obvious signal is observed. We set 90% C.L. upper limits on these modes, varying from 1.2 x 10(-4) for (B) over bar(0)-->D-0 pi(0) to 1.9 x 10(-3) for (B) over bar(0)-->D-(*0 eta'. C1 Univ Oklahoma, Norman, OK 73019 USA. Purdue Univ, W Lafayette, IN 47907 USA. Univ Rochester, Rochester, NY 14627 USA. Stanford Univ, Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. So Methodist Univ, Dallas, TX 75275 USA. Syracuse Univ, Syracuse, NY 13244 USA. Vanderbilt Univ, Nashville, TN 37235 USA. Virginia Polytech Inst & State Univ, Blacksburg, VA 24061 USA. Wayne State Univ, Detroit, MI 48202 USA. CALTECH, Pasadena, CA 91125 USA. Univ Calif San Diego, La Jolla, CA 92093 USA. Univ Calif Santa Barbara, Santa Barbara, CA 93106 USA. Univ Colorado, Boulder, CO 80309 USA. Cornell Univ, Ithaca, NY 14853 USA. Univ Florida, Gainesville, FL 32611 USA. Harvard Univ, Cambridge, MA 02138 USA. Univ Hawaii Manoa, Honolulu, HI 96822 USA. Univ Illinois, Urbana, IL 61801 USA. Carleton Univ, Ottawa, ON K1S 5B6, Canada. Inst Particle Phys, Ottawa, ON, Canada. McGill Univ, Montreal, PQ H3A 2T8, Canada. Ithaca Coll, Ithaca, NY 14850 USA. Univ Kansas, Lawrence, KS 66045 USA. Univ Minnesota, Minneapolis, MN 55455 USA. SUNY Albany, Albany, NY 12222 USA. Ohio State Univ, Columbus, OH 43210 USA. Yonsei Univ, Seoul 120749, South Korea. Brookhaven Natl Lab, Upton, NY 11973 USA. Univ Texas, Austin, TX 78712 USA. Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. BINP, RU-630090 Novosibirsk, Russia. RP Nemati, B (reprint author), Univ Oklahoma, Norman, OK 73019 USA. RI Briere, Roy/N-7819-2014 OI Briere, Roy/0000-0001-5229-1039 NR 9 TC 17 Z9 17 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 MAY 1 PY 1998 VL 57 IS 9 BP 5363 EP 5369 DI 10.1103/PhysRevD.57.5363 PG 7 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA ZL725 UT WOS:000073464200006 ER PT J AU Abe, F Akimoto, H Akopian, A Albrow, MG Amadon, A Amendolia, SR Amidei, D Antos, J Aota, S Apollinari, G Arisawa, T Asakawa, T Ashmanskas, W Atac, M Azfar, F Azzi-Bacchetta, P Bacchetta, N Bagdasarov, S Bailey, MW de Barbaro, P Barbaro-Galtieri, A Barnes, VE Barnett, BA Barone, M Bauer, G Baumann, T Bedeschi, F Behrends, S Belforte, S Bellettini, G Bellinger, J Benjamin, D Bensinger, J Beretvas, A Berge, JP Berryhill, J Bertolucci, S Bettelli, S Bevensee, B Bhatti, A Biery, K Bigongiari, C Binkley, M Bisello, D Blair, RE Blocker, C Blusk, S Bodek, A Bokhari, W Bolla, G Bonushkin, Y Bortoletto, D Boudreau, J Breccia, L Bromberg, C Bruner, N Brunetti, R Buckley-Geer, E Budd, HS Burkett, K Busetto, G Byon-Wagner, A Byrum, KL Cammerata, J Campbell, M Caner, A Carithers, W Carlsmith, D Cassada, J Castro, A Cauz, D Cerri, A Chang, PS Chang, PT Chao, HY Chapman, J Cheng, MT Chertok, M Chiarelli, G Chiou, CN Christofek, L Chu, ML Cihangir, S Clark, AG Cobal, M Cocca, E Contreras, M Conway, J Cooper, J Cordelli, M Costanzo, D Couyoumtzelis, C Cronin-Hennessy, D Culbertson, R Dagenhart, D Daniels, T DeJongh, F Dell'Agnello, S Dell'Orso, M Demina, R Demortier, L Deninno, M Derwent, PF Devlin, T Dittmann, JR Donati, S Done, J Dorigo, T Eddy, N Einsweiler, K Elias, JE Ely, R Engels, E Erdmann, W Errede, D Errede, S Fan, Q Feild, RG Feng, Z Ferretti, C Fiori, I Flaugher, B Foster, GW Franklin, M Freeman, J Friedman, J Frisch, H Fukui, Y Gadomski, S Galeotti, S Gallinaro, M Ganel, O Garcia-Sciveres, M Garfinkel, AF Gay, C Geer, S Gerdes, DW Giannetti, P Giokaris, N Giromini, P Giusti, G Gold, M Gordon, A Goshaw, AT Gotra, Y Goulianos, K Grassmann, H Groer, L Grosso-Pilcher, C Guillian, G da Costa, JG Guo, RS Haber, C Hafen, E Hahn, SR Hamilton, R Handa, T Handler, R Happacher, F Hara, K Hardman, AD Harris, RM Hartmann, F Hauser, J Hayashi, E Heinrich, J Hao, W Hinrichsen, B Hoffman, KD Hohlmann, M Holck, C Hollebeek, R Holloway, L Huang, Z Huffman, BT Hughes, R Huston, J Huth, J Ikeda, H Incagli, M Incandela, J Introzzi, G Iwai, J Iwata, Y James, E Jensen, H Joshi, U Kajfasz, E Kambara, H Kamon, T Kaneko, T Karr, K Kasha, H Kato, Y Keaffaber, TA Kelley, K Kennedy, RD Kephart, R Kestenbaum, D Khazins, D Kikuchi, T Kim, BJ Kim, HS Kim, SH Kim, YK Kirsch, L Klimenko, S Knoblauch, D Koehn, P Kongeter, A Kondo, K Konigsberg, J Kordas, K Korytov, A Kovacs, E Kowald, W Kroll, J Kruse, M Kuhlmann, SE Kuns, E Kurino, K Kuwabara, T Laasanen, AT Nakano, I Lami, S Lammel, S Lamoureux, JI Lancaster, M Lanzoni, M Latino, G LeCompte, T Leone, S Lewis, JD Limon, P Lindgren, M Liss, TM Liu, JB Liu, YC Lockyer, N Long, O Loomis, C Loreti, M Lucchesi, D Lukens, P Lusin, S Lys, J Maeshima, K Maksimovic, P Mangano, M Mariotti, M Marriner, JP Martin, A Matthews, JAJ Mazzanti, P McIntyre, P Melese, P Menguzzato, M Menzione, A Meschi, E Metzler, S Miao, C Miao, T Michail, G Miller, R Minato, H Miscetti, S Mishina, M Miyashita, S Moggi, N Moore, E Morita, Y Mukherjee, A Muller, T Murat, P Murgia, S Nakada, H Nakano, I Nelson, C Neuberger, D Newman-Holmes, C Ngan, CYP Nodulman, L Oh, SH Ohmoto, T Ohsugi, T Oishi, R Okabe, M Okusawa, T Olsen, J Pagliarone, C Paoletti, R Papadimitriou, V Pappas, SP Parashar, N Parri, A Patrick, J Pauletta, G Paulini, M Perazzo, A Pescara, L Peters, MD Phillips, TJ Piacentino, G Pillai, M Pitts, KT Plunkett, R Pondrom, L Proudfoot, J Ptohos, F Punzi, G Ragan, K Reher, D Reischl, M Ribon, A Rimondi, F Ristori, L Robertson, WJ Rodrigo, T Rolli, S Rosenson, L Roser, R Saab, T Sakumoto, WK Saltzberg, D Sansoni, A Santi, L Sato, H Schlabach, P Schmidt, EE Schmidt, MP Scott, A Scribano, A Segler, S Seidel, S Seiya, Y Semeria, F Shah, T Shapiro, MD Shaw, NM Shepard, PF Shibayama, T Shimojima, M Shochet, M Siegrist, J Sill, A Sinervo, P Singh, P Skarha, J Sliwa, K Smith, C Snider, FD Spalding, J Speer, T Sphicas, P Spinella, F Spiropulu, M Spiegel, L Stanco, L Steele, J Stefanini, A Strohmer, R Strologas, J Strumia, F Stuart, D Sumorok, K Suzuki, J Suzuki, T Takahashi, T Takano, T Takashima, R Takikawa, K Tanaka, M Tannenbaum, B Tartarelli, F Taylor, W Tecchio, M Teng, PK Teramoto, Y Terashi, K Tether, S Theriot, D Thomas, TL Thurman-Keup, R Timko, M Tipton, P Titov, A Tkaczyk, S Toback, D Tollefson, K Tollestrup, A Toyoda, H Trischuk, W de Troconiz, JF Truitt, S Tseng, J Turini, N Uchida, T Ukegawa, F Valls, J van den Brink, SC Vejcik, S Velev, G Vidal, R Vilar, R Vucinic, D Wagner, RG Wagner, RL Wahl, J Wallace, NB Walsh, AM Wang, C Wang, CH Wang, MJ Warburton, A Watanabe, T Watts, T Webb, R Wei, C Wenzel, H Wester, WC Wicklund, AB Wicklund, E Wilkinson, R Williams, HH Wilson, P Winer, BL Winn, D Wolinski, D Wolinski, J Worm, S Wu, X Wyss, J Yagil, A Yao, W Yasuoka, K Yeh, GP Yeh, P Yoh, J Yosef, C Yoshida, T Yu, I Zanetti, A Zetti, F Zucchelli, S AF Abe, F Akimoto, H Akopian, A Albrow, MG Amadon, A Amendolia, SR Amidei, D Antos, J Aota, S Apollinari, G Arisawa, T Asakawa, T Ashmanskas, W Atac, M Azfar, F Azzi-Bacchetta, P Bacchetta, N Bagdasarov, S Bailey, MW de Barbaro, P Barbaro-Galtieri, A Barnes, VE Barnett, BA Barone, M Bauer, G Baumann, T Bedeschi, F Behrends, S Belforte, S Bellettini, G Bellinger, J Benjamin, D Bensinger, J Beretvas, A Berge, JP Berryhill, J Bertolucci, S Bettelli, S Bevensee, B Bhatti, A Biery, K Bigongiari, C Binkley, M Bisello, D Blair, RE Blocker, C Blusk, S Bodek, A Bokhari, W Bolla, G Bonushkin, Y Bortoletto, D Boudreau, J Breccia, L Bromberg, C Bruner, N Brunetti, R Buckley-Geer, E Budd, HS Burkett, K Busetto, G Byon-Wagner, A Byrum, KL Cammerata, J Campbell, M Caner, A Carithers, W Carlsmith, D Cassada, J Castro, A Cauz, D Cerri, A Chang, PS Chang, PT Chao, HY Chapman, J Cheng, MT Chertok, M Chiarelli, G Chiou, CN Christofek, L Chu, ML Cihangir, S Clark, AG Cobal, M Cocca, E Contreras, M Conway, J Cooper, J Cordelli, M Costanzo, D Couyoumtzelis, C Cronin-Hennessy, D Culbertson, R Dagenhart, D Daniels, T DeJongh, F Dell'Agnello, S Dell'Orso, M Demina, R Demortier, L Deninno, M Derwent, PF Devlin, T Dittmann, JR Donati, S Done, J Dorigo, T Eddy, N Einsweiler, K Elias, JE Ely, R Engels, E Erdmann, W Errede, D Errede, S Fan, Q Feild, RG Feng, Z Ferretti, C Fiori, I Flaugher, B Foster, GW Franklin, M Freeman, J Friedman, J Frisch, H Fukui, Y Gadomski, S Galeotti, S Gallinaro, M Ganel, O Garcia-Sciveres, M Garfinkel, AF Gay, C Geer, S Gerdes, DW Giannetti, P Giokaris, N Giromini, P Giusti, G Gold, M Gordon, A Goshaw, AT Gotra, Y Goulianos, K Grassmann, H Groer, L Grosso-Pilcher, C Guillian, G da Costa, JG Guo, RS Haber, C Hafen, E Hahn, SR Hamilton, R Handa, T Handler, R Happacher, F Hara, K Hardman, AD Harris, RM Hartmann, F Hauser, J Hayashi, E Heinrich, J Hao, W Hinrichsen, B Hoffman, KD Hohlmann, M Holck, C Hollebeek, R Holloway, L Huang, Z Huffman, BT Hughes, R Huston, J Huth, J Ikeda, H Incagli, M Incandela, J Introzzi, G Iwai, J Iwata, Y James, E Jensen, H Joshi, U Kajfasz, E Kambara, H Kamon, T Kaneko, T Karr, K Kasha, H Kato, Y Keaffaber, TA Kelley, K Kennedy, RD Kephart, R Kestenbaum, D Khazins, D Kikuchi, T Kim, BJ Kim, HS Kim, SH Kim, YK Kirsch, L Klimenko, S Knoblauch, D Koehn, P Kongeter, A Kondo, K Konigsberg, J Kordas, K Korytov, A Kovacs, E Kowald, W Kroll, J Kruse, M Kuhlmann, SE Kuns, E Kurino, K Kuwabara, T Laasanen, AT Nakano, I Lami, S Lammel, S Lamoureux, JI Lancaster, M Lanzoni, M Latino, G LeCompte, T Leone, S Lewis, JD Limon, P Lindgren, M Liss, TM Liu, JB Liu, YC Lockyer, N Long, O Loomis, C Loreti, M Lucchesi, D Lukens, P Lusin, S Lys, J Maeshima, K Maksimovic, P Mangano, M Mariotti, M Marriner, JP Martin, A Matthews, JAJ Mazzanti, P McIntyre, P Melese, P Menguzzato, M Menzione, A Meschi, E Metzler, S Miao, C Miao, T Michail, G Miller, R Minato, H Miscetti, S Mishina, M Miyashita, S Moggi, N Moore, E Morita, Y Mukherjee, A Muller, T Murat, P Murgia, S Nakada, H Nakano, I Nelson, C Neuberger, D Newman-Holmes, C Ngan, CYP Nodulman, L Oh, SH Ohmoto, T Ohsugi, T Oishi, R Okabe, M Okusawa, T Olsen, J Pagliarone, C Paoletti, R Papadimitriou, V Pappas, SP Parashar, N Parri, A Patrick, J Pauletta, G Paulini, M Perazzo, A Pescara, L Peters, MD Phillips, TJ Piacentino, G Pillai, M Pitts, KT Plunkett, R Pondrom, L Proudfoot, J Ptohos, F Punzi, G Ragan, K Reher, D Reischl, M Ribon, A Rimondi, F Ristori, L Robertson, WJ Rodrigo, T Rolli, S Rosenson, L Roser, R Saab, T Sakumoto, WK Saltzberg, D Sansoni, A Santi, L Sato, H Schlabach, P Schmidt, EE Schmidt, MP Scott, A Scribano, A Segler, S Seidel, S Seiya, Y Semeria, F Shah, T Shapiro, MD Shaw, NM Shepard, PF Shibayama, T Shimojima, M Shochet, M Siegrist, J Sill, A Sinervo, P Singh, P Skarha, J Sliwa, K Smith, C Snider, FD Spalding, J Speer, T Sphicas, P Spinella, F Spiropulu, M Spiegel, L Stanco, L Steele, J Stefanini, A Strohmer, R Strologas, J Strumia, F Stuart, D Sumorok, K Suzuki, J Suzuki, T Takahashi, T Takano, T Takashima, R Takikawa, K Tanaka, M Tannenbaum, B Tartarelli, F Taylor, W Tecchio, M Teng, PK Teramoto, Y Terashi, K Tether, S Theriot, D Thomas, TL Thurman-Keup, R Timko, M Tipton, P Titov, A Tkaczyk, S Toback, D Tollefson, K Tollestrup, A Toyoda, H Trischuk, W de Troconiz, JF Truitt, S Tseng, J Turini, N Uchida, T Ukegawa, F Valls, J van den Brink, SC Vejcik, S Velev, G Vidal, R Vilar, R Vucinic, D Wagner, RG Wagner, RL Wahl, J Wallace, NB Walsh, AM Wang, C Wang, CH Wang, MJ Warburton, A Watanabe, T Watts, T Webb, R Wei, C Wenzel, H Wester, WC Wicklund, AB Wicklund, E Wilkinson, R Williams, HH Wilson, P Winer, BL Winn, D Wolinski, D Wolinski, J Worm, S Wu, X Wyss, J Yagil, A Yao, W Yasuoka, K Yeh, GP Yeh, P Yoh, J Yosef, C Yoshida, T Yu, I Zanetti, A Zetti, F Zucchelli, S CA CDF Collaboration TI Measurement of B hadron lifetimes using J/psi final states at CDF SO PHYSICAL REVIEW D LA English DT Article ID AVERAGE LIFETIME; MESON LIFETIMES; B-S(0) MESON; Z-DECAYS; P(P)OVER-BAR COLLISIONS; PRECISION-MEASUREMENT; E+E ANNIHILATION; Z(0) DECAYS; BARYONS; B-0 AB The average bottom-hadron and individual B+, B-0, and B-s(0) meson lifetimes have been determined using decays with a J/psi --> u(+)u(-) the final state. The data sample consists of 110 pb(-1) of pp collisions at root s = 1.8 TeV collected by the CDF detector at the Fermilab Tevatron collider during 1992-1995. For the average lifetime of B hadrons decaying into J/(psi + X, we obtain [tau(b)] = 1.533 +/- 0.015(stat)(-0.031)(+0.035) (syst) ps. For the B+ and B-0 meson lifetimes, we determine tau(B+) = 1.68 +/- 0.07(stat) +/- 0.02(syst) ps, tau(B-0) = 1.58 +/- 0.09(stat) +/- 0.02(syst) ps, and tau(B+)/tau(B-0) = 1.06 +/- 0.07(stat) +/- 0.02(syst). For the B-s(0) meson lifetime, we find tau(B-s(0)) = 1.34(-0.19)(+0.23)(stat) +/- 0.05(syst) ps. C1 Natl Lab High Energy Phys, KEK, Tsukuba, Ibaraki 305, Japan. Argonne Natl Lab, Argonne, IL 60439 USA. Univ Bologna, INFN, I-40127 Bologna, Italy. Brandeis Univ, Waltham, MA 02254 USA. Univ Calif Los Angeles, Los Angeles, CA 90024 USA. Univ Chicago, Chicago, IL 60637 USA. Duke Univ, Durham, NC 27708 USA. Fermi Natl Accelerator Lab, Batavia, IL 60510 USA. Univ Florida, Gainesville, FL 32611 USA. Ist Nazl Fis Nucl, Lab Nazl Frascati, I-00044 Frascati, Italy. Univ Geneva, CH-1211 Geneva 4, Switzerland. Harvard Univ, Cambridge, MA 02138 USA. Hiroshima Univ, Higashihiroshima 724, Japan. Univ Illinois, Urbana, IL 61801 USA. McGill Univ, Inst Particle Phys, Montreal, PQ H3A 2T8, Canada. Univ Toronto, Toronto, ON M5S 1A7, Canada. Johns Hopkins Univ, Baltimore, MD 21218 USA. Univ Karlsruhe, Inst Expt Kernphys, D-76128 Karlsruhe, Germany. Ernest Orlando Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. MIT, Cambridge, MA 02139 USA. Univ Michigan, Ann Arbor, MI 48109 USA. Michigan State Univ, E Lansing, MI 48824 USA. Univ New Mexico, Albuquerque, NM 87131 USA. Ohio State Univ, Columbus, OH 43210 USA. Osaka City Univ, Osaka 588, Japan. Univ Padua, Ist Nazl Fis Nucl, I-35131 Padua, Italy. Univ Penn, Philadelphia, PA 19104 USA. Univ Pisa, Ist Nazl Fis Nucl, I-56100 Pisa, Italy. Scuola Normale Super Pisa, I-56100 Pisa, Italy. Univ Pittsburgh, Pittsburgh, PA 15260 USA. Purdue Univ, W Lafayette, IN 47907 USA. Univ Rochester, Rochester, NY 14627 USA. Rockefeller Univ, New York, NY 10021 USA. Rutgers State Univ, Piscataway, NJ 08855 USA. Acad Sinica, Taipei 11530, Taiwan. Texas A&M Univ, College Stn, TX 77843 USA. Texas Tech Univ, Lubbock, TX 79409 USA. Univ Tsukuba, Tsukuba, Ibaraki 315, Japan. Tufts Univ, Medford, MA 02155 USA. Univ Wisconsin, Madison, WI 53706 USA. Yale Univ, New Haven, CT 06520 USA. Waseda Univ, Tokyo 169, Japan. Univ Trieste, Ist Nazl Fis Nucl, Udine, Italy. RP Abe, F (reprint author), Natl Lab High Energy Phys, KEK, Tsukuba, Ibaraki 305, Japan. RI Lancaster, Mark/C-1693-2008; Vucinic, Dejan/C-2406-2008; Azzi, Patrizia/H-5404-2012; Punzi, Giovanni/J-4947-2012; Chiarelli, Giorgio/E-8953-2012; Warburton, Andreas/N-8028-2013; Paulini, Manfred/N-7794-2014; Introzzi, Gianluca/K-2497-2015; vilar, rocio/D-7454-2014 OI CHANG, PAO-TI/0000-0003-4064-388X; Lami, Stefano/0000-0001-9492-0147; Toback, David/0000-0003-3457-4144; Azzi, Patrizia/0000-0002-3129-828X; Punzi, Giovanni/0000-0002-8346-9052; Chiarelli, Giorgio/0000-0001-9851-4816; Warburton, Andreas/0000-0002-2298-7315; Paulini, Manfred/0000-0002-6714-5787; Introzzi, Gianluca/0000-0002-1314-2580; NR 57 TC 48 Z9 48 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2821 J9 PHYS REV D JI Phys. Rev. D PD MAY 1 PY 1998 VL 57 IS 9 BP 5382 EP 5401 DI 10.1103/PhysRevD.57.5382 PG 20 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA ZL725 UT WOS:000073464200008 ER PT J AU Bhattacharya, T Gupta, R Maltman, K AF Bhattacharya, T Gupta, R Maltman, K TI Extraction of light quark masses from sum rule analyses of axial vector and vector current Ward identities SO PHYSICAL REVIEW D LA English DT Article ID CHIRAL PERTURBATION-THEORY; RESONANCE PHYSICS; STRANGE QUARK; QCD; CHROMODYNAMICS; BREAKING; MODEL AB In light of recent lattice results for the light quark masses m(s) and m(u)+ m(d), we reexamine the use of sum rules in the extraction of these quantities, and discuss a number of potential problems with existing analyses. The most important issue is that of the overall normalization of the hadronic spectral functions relevant to the sum rule analyses. We explain why previous treatments, which fix this normalization by assuming complete resonance dominance of the continuum threshold region, can potentially overestimate the resonance contributions to spectral integrals by factors as large as similar to 5. We propose an alternate method of normalization based on an understanding of the role of resonances in chiral perturbation theory which avoids this problem. The second important uncertainty we consider relates to the physical content of the assumed location s(0) of the onset of duality with perturbative QCD. We find that the extracted quark masses depend very sensitively on this parameter. We show that the assumption of duality imposes very severe constraints on the shape of the relevant spectral function in the dual region and present rigorous lower bounds for m(u) + m(d) as a function of so based on a combination of these constraints and the requirement of positivity of rho(5)(s). In the extractions of m(s), we find that the conventional choice of the value of s(0) is not physical. For a more reasonable choice of s(0), we are not able to find a solution that is stable with respect to variations of the Borel transform parameter. This problem can, unfortunately, be overcome only if the hadronic spectral function is determined up to significantly larger values of s than is currently possible. Finally, we also estimate the error associated with the convergence of perturbative QCD expressions used in the sum rule analyses. Our conclusion is that, taking all of these issues into account, the resulting sum rule estimates for both m(u) + m(d) and m(s) could easily have uncertainties as large as a factor of 2, which would make them compatible with the low estimates obtained from lattice QCD. C1 Univ Calif Los Alamos Natl Lab, Grp T8, Los Alamos, NM 87545 USA. York Univ, Dept Math & Stat, N York, ON M3J 1P3, Canada. Univ Adelaide, Special Res Ctr Subatom Struct Matter, Adelaide, SA 5005, Australia. RP Bhattacharya, T (reprint author), Univ Calif Los Alamos Natl Lab, Grp T8, Mail Stop B-285, Los Alamos, NM 87545 USA. RI Bhattacharya, Tanmoy/J-8956-2013 OI Bhattacharya, Tanmoy/0000-0002-1060-652X NR 34 TC 16 Z9 16 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2821 J9 PHYS REV D JI Phys. Rev. D PD MAY 1 PY 1998 VL 57 IS 9 BP 5455 EP 5467 DI 10.1103/PhysRevD.57.5455 PG 13 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA ZL725 UT WOS:000073464200015 ER PT J AU Jalilian-Marian, J Tekin, B AF Jalilian-Marian, J Tekin, B TI Temperature dependence of eta and eta ' masses SO PHYSICAL REVIEW D LA English DT Article ID HEAVY-ION COLLISIONS; FINITE-TEMPERATURE; RESTORATION; SYMMETRY AB We investigate the temperature dependence of eta and eta' masses due to scatterings from thermal pions in a heat bath using the nonlinear sigma model. We show that mass shifts of eta and eta' and the shift in the mixing angle are negligible. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Div Nucl Sci, Berkeley, CA 94720 USA. Univ Minnesota, Sch Phys & Astron, Minneapolis, MN 55455 USA. RP Jalilian-Marian, J (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Div Nucl Sci, 1 Cyclotron Rd, Berkeley, CA 94720 USA. NR 19 TC 2 Z9 2 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2821 J9 PHYS REV D JI Phys. Rev. D PD MAY 1 PY 1998 VL 57 IS 9 BP 5593 EP 5597 DI 10.1103/PhysRevD.57.5593 PG 5 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA ZL725 UT WOS:000073464200030 ER PT J AU Close, FE Dunietz, I Page, PR Veseli, S Yamamoto, H AF Close, FE Dunietz, I Page, PR Veseli, S Yamamoto, H TI Gluonic hadrons and charmless B decays SO PHYSICAL REVIEW D LA English DT Article ID FLUX-TUBE MODEL; HYBRID MESONS; QQBARG HYBRID; QCD; CHARMONIUM; ENHANCEMENT; RESONANCE; LATTICE AB Hybrid charmonium with mass similar to 4 GeV could be produced via a color-octet: component in b-->c(c) over bars$. These states could be narrow and could have a significant branching ratio to Light hadrons, perhaps enhanced by glueballs. Decays to gluonic hadrons could make a sizable contribution to B-->no charm decays. Experimental signatures and search strategies are discussed. C1 Rutherford Appleton Lab, Didcot OX11 0QX, Oxon, England. Fermi Natl Accelerator Lab, Batavia, IL 60510 USA. Thomas Jefferson Natl Accelerator Facil, Newport News, VA 23606 USA. Harvard Univ, Cambridge, MA 02138 USA. RP Close, FE (reprint author), Rutherford Appleton Lab, Didcot OX11 0QX, Oxon, England. RI Page, Philip/L-1885-2015 OI Page, Philip/0000-0002-2201-6703 NR 48 TC 29 Z9 29 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2821 J9 PHYS REV D JI Phys. Rev. D PD MAY 1 PY 1998 VL 57 IS 9 BP 5653 EP 5657 DI 10.1103/PhysRevD.57.5653 PG 5 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA ZL725 UT WOS:000073464200035 ER PT J AU de Gouvea, A Friedland, A Murayama, H AF de Gouvea, A Friedland, A Murayama, H TI Next-to-minimal supersymmetric standard model with the gauge mediation of supersymmetry breaking SO PHYSICAL REVIEW D LA English DT Article ID ABELIAN HORIZONTAL SYMMETRIES; SOFTLY BROKEN SUPERSYMMETRY; MU-PROBLEM; LOCAL SUPERSYMMETRY; GRAND UNIFICATION; FLAVOR SYMMETRY; MODULI SPACES; SUPERGRAVITY; HIERARCHY; ENERGIES AB We study the next-to-minimal supersymmetric standard model (NMSSM) as the simplest candidate solution to the p-problem in the context of the gauge mediation of supersymmetry breaking (GMSB). We first review various proposals to solve the mu-problem in models with the GMSB. We find none of them entirely satisfactory and point out that many of the scenarios still lack quantitative studies, and motivate the NMSSM as the simplest possible solution. We then study the situation in the minimal supersymmetric standard model (MSSM) with the GMSB and find that an order 10% cancellation is necessary between the mu-parameter and the soft SUSY-breaking parameters to correctly reproduce M-Z. Unfortunately, the NMSSM does not give a phenomenologically viable solution to the mu-problem. We present quantitative arguments which apply both for the low-energy and high-energy GMSB and prove that the NMSSM does not work for either case. Possible modifications to the NMSSM are then discussed. The NMSSM with additional vector-like quarks works phenomenologically, but requires an order of a few percent cancellation among parameters. We point out that this cancellation has the same origin as the cancellation required in the MSSM. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Theoret Phys Grp, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. RP Univ Calif Berkeley, Lawrence Berkeley Lab, Theoret Phys Grp, Berkeley, CA 94720 USA. RI Murayama, Hitoshi/A-4286-2011 NR 95 TC 64 Z9 64 U1 0 U2 0 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 2470-0010 EI 2470-0029 J9 PHYS REV D JI Phys. Rev. D PD MAY 1 PY 1998 VL 57 IS 9 BP 5676 EP 5696 DI 10.1103/PhysRevD.57.5676 PG 21 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA ZL725 UT WOS:000073464200039 ER PT J AU Suzuki, M AF Suzuki, M TI Long-distance final-state interactions and J/psi decay SO PHYSICAL REVIEW D LA English DT Article ID STRONG PHASES; CP-VIOLATION; PENGUINS AB To understand the short-versus long-distance final-state interactions, we have performed a detailed amplitude analysis for the two-body decay J/psi --> 1(-)0(-). The current data favor a large relative phase nearly 90 degrees between the three-gluon and the one-photon decay amplitudes. The source of the phase is apparently the long-distance final-state interaction. Nothing anomalous is found in the magnitudes of the three-gluon and one-photon decay amplitudes. We discuss the implications of this large phase in the weak decay of heavy particles. C1 Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Suzuki, M (reprint author), Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. NR 21 TC 17 Z9 18 U1 0 U2 1 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2821 J9 PHYS REV D JI Phys. Rev. D PD MAY 1 PY 1998 VL 57 IS 9 BP 5717 EP 5722 DI 10.1103/PhysRevD.57.5717 PG 6 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA ZL725 UT WOS:000073464200043 ER PT J AU Dawson, S Reina, L AF Dawson, S Reina, L TI QCD corrections to associated Higgs boson production SO PHYSICAL REVIEW D LA English DT Article ID EFFECTIVE W APPROXIMATION; HEAVY-QUARK PRODUCTION; RADIATIVE-CORRECTIONS; PROTON COLLIDERS; PPBAR COLLISIONS; TOP QUARKS AB We compute QCD corrections to the processes e(+)e(-)-->t (t) over bar h(0) and pp-->t (t) over bar h(0) by treating the Higgs boson as a parton which radiates off a heavy quark. This approximation is valid in the limits M-h much less than M-t and M-h,M-t much less than root s. The corrections increase the rate for pp-->t (t) over bar h(0) at the CERN LHC by a factor of 1.2 to 1.5 over the lowest order rate for an intermediate mass Higgs boson, M-h<180 GeV. The QCD corrections are small fore(+)e(-)-->t (t) over bar h(0) at root s=1 TeV. C1 Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. Univ Wisconsin, Dept Phys, Madison, WI 53706 USA. RP Dawson, S (reprint author), Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. OI Dawson, Sally/0000-0002-5598-695X NR 27 TC 51 Z9 52 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2821 J9 PHYS REV D JI Phys. Rev. D PD MAY 1 PY 1998 VL 57 IS 9 BP 5851 EP 5859 DI 10.1103/PhysRevD.57.5851 PG 9 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA ZL725 UT WOS:000073464200058 ER PT J AU Feng, JL Moroi, T Murayama, H Schnapka, E AF Feng, JL Moroi, T Murayama, H Schnapka, E TI Third generation familons, B factories, and neutrino cosmology SO PHYSICAL REVIEW D LA English DT Article ID BIG-BANG NUCLEOSYNTHESIS; COLD DARK-MATTER; NUCLEON SPIN FLUCTUATIONS; TAU-NEUTRINO; GOLDSTONE BOSONS; BRANCHING RATIO; GAUGE-SYMMETRY; UPPER LIMIT; LARGE-SCALE; AXIONS AB We study the physics of spontaneously broken family symmetries acting on the third generation. Massless familons (or Majorons) f associated with such broken symmetries are motivated especially by cosmological scenarios with decaying tau neutrinos. We first note that, in marked contrast to the case for the first two generations, constraints on third generation familon couplings are poor, and are, in fact, non-existent at present in the hadronic sector. We derive new bounds from B-0-(B) over bar(0) mixing, B-0-->l(+)l'(-), b-->s nu<(nu)over bar>, and astrophysics. The resulting constraints on familon decay constants are still much weaker than those for the first and second generation. We then discuss the promising prospects for significant improvements from searches for tau-->lf, B-->(pi,K)f, and b-->(d,s)f with the current CLEO, ARGUS, and CERN LEP data. Finally, we note that future constraints from CLEO III and the B factories will probe decay constants beyond 10(8) GeV, well within regions of parameter space favored by proposed scenarios in neutrino cosmology. C1 Univ Calif Berkeley, Ernest Orlando Lawrence Berkeley Natl Lab, Theoret Phys Grp, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. RP Feng, JL (reprint author), Univ Calif Berkeley, Ernest Orlando Lawrence Berkeley Natl Lab, Theoret Phys Grp, Berkeley, CA 94720 USA. RI Murayama, Hitoshi/A-4286-2011 NR 83 TC 32 Z9 32 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2821 J9 PHYS REV D JI Phys. Rev. D PD MAY 1 PY 1998 VL 57 IS 9 BP 5875 EP 5892 DI 10.1103/PhysRevD.57.5875 PG 18 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA ZL725 UT WOS:000073464200061 ER PT J AU Bliss, DW Masek, G Paar, HP Prell, S Sharma, V Asner, DM Gronberg, J Hill, TS Lange, DJ Morrison, RJ Nelson, HN Nelson, TK Roberts, D Ryd, A Balest, R Behrens, BH Ford, WT Park, H Roy, J Smith, JG Alexander, JP Baker, R Bebek, C Berger, BE Berkelman, K Bloom, K Boisvert, V Cassel, DG Crowcroft, DS Dickson, M von Dombrowski, S Drell, PS Ecklund, KM Ehrlich, R Foland, AD Gaidarev, P Galik, RS Gibbons, L Gittelman, B Gray, SW Hartill, DL Heltsley, BK Hopman, PI Kandaswamy, J Kim, PC Kreinick, DL Lee, T Liu, Y Mistry, NB Ng, CR Nordberg, E Ogg, M Patterson, JR Peterson, D Riley, D Soffer, A Valant-Spaight, B Ward, C Athanas, M Avery, P Jones, CD Lohner, M Patton, S Prescott, C Yelton, J Zheng, J Brandenburg, G Briere, RA Ershov, A Gao, YS Kim, DYJ Wilson, R Yamamoto, H Browder, TE Li, Y Rodriguez, JL Bergfeld, T Eisenstein, BI Ernst, J Gladding, GE Gollin, GD Hans, RM Johnson, E Karliner, I Marsh, MA Palmer, M Selen, M Thaler, JJ Edwards, KW Bellerive, A Janicek, R MacFarlane, DB Patel, PM Sadoff, AJ Ammar, R Baringer, P Bean, A Besson, D Coppage, D Darling, C Davis, R Kotov, S Kravchenko, I Kwak, N Zhou, L Anderson, S Kubota, Y Lee, SJ O'Neill, JJ Poling, R Riehle, T Smith, A Alam, MS Athar, SB Ling, Z Mahmood, AH Timm, S Wappler, F Anastassov, A Duboscq, JE Fujino, D Gan, KK Hart, T Honscheid, K Kagan, H Kass, R Lee, J Spencer, MB Sung, M Undrus, A Wanke, R Wolf, A Zoeller, MM Nemati, B Richichi, SJ Ross, WR Severini, H Skubic, P Bishai, M Fast, J Hinson, JW Menon, N Miller, DH Shibata, EI Shipsey, IPJ Yurko, M Glenn, S Johnson, SD Kwon, Y Roberts, S Thorndike, EH Jessop, CP Lingel, K Marsiske, H Perl, ML Savinov, V Ugolini, D Wang, R Zhou, X Coan, TE Fadeyev, V Korolkov, I Maravin, Y Narsky, I Shelkov, V Staeck, J Stroynowski, R Volobouev, I Ye, J Artuso, M Azfar, F Efimov, A Goldberg, M He, D Kopp, S Moneti, GC Mountain, R Schuh, S Skwarnicki, T Stone, S Viehhauser, G Xing, X Bartelt, J Csorna, SE Jain, V McLean, KW Marka, S Godang, R Kinoshita, K Lai, IC Pomianowski, P Schrenk, S Bonvicini, G Cinabro, D Greene, R Perera, LP Zhou, GJ Chadha, M Chan, S Eigen, G Miller, JS O'Grady, C Schmidtler, M Urheim, J Weinstein, AJ Wurthwein, F AF Bliss, DW Masek, G Paar, HP Prell, S Sharma, V Asner, DM Gronberg, J Hill, TS Lange, DJ Morrison, RJ Nelson, HN Nelson, TK Roberts, D Ryd, A Balest, R Behrens, BH Ford, WT Park, H Roy, J Smith, JG Alexander, JP Baker, R Bebek, C Berger, BE Berkelman, K Bloom, K Boisvert, V Cassel, DG Crowcroft, DS Dickson, M von Dombrowski, S Drell, PS Ecklund, KM Ehrlich, R Foland, AD Gaidarev, P Galik, RS Gibbons, L Gittelman, B Gray, SW Hartill, DL Heltsley, BK Hopman, PI Kandaswamy, J Kim, PC Kreinick, DL Lee, T Liu, Y Mistry, NB Ng, CR Nordberg, E Ogg, M Patterson, JR Peterson, D Riley, D Soffer, A Valant-Spaight, B Ward, C Athanas, M Avery, P Jones, CD Lohner, M Patton, S Prescott, C Yelton, J Zheng, J Brandenburg, G Briere, RA Ershov, A Gao, YS Kim, DYJ Wilson, R Yamamoto, H Browder, TE Li, Y Rodriguez, JL Bergfeld, T Eisenstein, BI Ernst, J Gladding, GE Gollin, GD Hans, RM Johnson, E Karliner, I Marsh, MA Palmer, M Selen, M Thaler, JJ Edwards, KW Bellerive, A Janicek, R MacFarlane, DB Patel, PM Sadoff, AJ Ammar, R Baringer, P Bean, A Besson, D Coppage, D Darling, C Davis, R Kotov, S Kravchenko, I Kwak, N Zhou, L Anderson, S Kubota, Y Lee, SJ O'Neill, JJ Poling, R Riehle, T Smith, A Alam, MS Athar, SB Ling, Z Mahmood, AH Timm, S Wappler, F Anastassov, A Duboscq, JE Fujino, D Gan, KK Hart, T Honscheid, K Kagan, H Kass, R Lee, J Spencer, MB Sung, M Undrus, A Wanke, R Wolf, A Zoeller, MM Nemati, B Richichi, SJ Ross, WR Severini, H Skubic, P Bishai, M Fast, J Hinson, JW Menon, N Miller, DH Shibata, EI Shipsey, IPJ Yurko, M Glenn, S Johnson, SD Kwon, Y Roberts, S Thorndike, EH Jessop, CP Lingel, K Marsiske, H Perl, ML Savinov, V Ugolini, D Wang, R Zhou, X Coan, TE Fadeyev, V Korolkov, I Maravin, Y Narsky, I Shelkov, V Staeck, J Stroynowski, R Volobouev, I Ye, J Artuso, M Azfar, F Efimov, A Goldberg, M He, D Kopp, S Moneti, GC Mountain, R Schuh, S Skwarnicki, T Stone, S Viehhauser, G Xing, X Bartelt, J Csorna, SE Jain, V McLean, KW Marka, S Godang, R Kinoshita, K Lai, IC Pomianowski, P Schrenk, S Bonvicini, G Cinabro, D Greene, R Perera, LP Zhou, GJ Chadha, M Chan, S Eigen, G Miller, JS O'Grady, C Schmidtler, M Urheim, J Weinstein, AJ Wurthwein, F CA CLEO Collaboration TI New limits for neutrinoless tau decays SO PHYSICAL REVIEW D LA English DT Article ID LEPTON-FLAVOR VIOLATION; STRING MODELS; COUPLINGS; SYMMETRY; LIBRARY; NUMBER; MUON AB Neutrinoless 3-prong tau lepton decays into a charged lepton and either two charged particles or one neutral meson have been searched for using 4.79 fb(-1) of data collected with the CLEO II detector at Cornell Electron Storage Ring. This analysis represents an update of a previous study and the addition of six decay channels. In all channels the numbers of events found are compatible with background estimates and branching fraction upper limits are set for 28 different decay modes. These limits an either more stringent than those set previously or represent the first attempt to find these decays. C1 Univ Calif San Diego, La Jolla, CA 92093 USA. Univ Calif Santa Barbara, Santa Barbara, CA 93106 USA. Univ Colorado, Boulder, CO 80309 USA. Cornell Univ, Ithaca, NY 14853 USA. Univ Florida, Gainesville, FL 32611 USA. Harvard Univ, Cambridge, MA 02138 USA. Univ Hawaii Manoa, Honolulu, HI 96822 USA. Univ Illinois, Urbana, IL 61801 USA. Carleton Univ, Ottawa, ON K1S 5B6, Canada. Inst Particle Phys, Ottawa, ON, Canada. Ithaca Coll, Ithaca, NY 14850 USA. Univ Kansas, Lawrence, KS 66045 USA. Univ Minnesota, Minneapolis, MN 55455 USA. SUNY Albany, Albany, NY 12222 USA. Ohio State Univ, Columbus, OH 43210 USA. Univ Oklahoma, Norman, OK 73019 USA. Purdue Univ, W Lafayette, IN 47907 USA. Univ Rochester, Rochester, NY 14627 USA. Stanford Univ, Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. So Methodist Univ, Dallas, TX 75275 USA. Syracuse Univ, Syracuse, NY 13244 USA. Vanderbilt Univ, Nashville, TN 37235 USA. Virginia Polytech Inst & State Univ, Blacksburg, VA 24061 USA. Wayne State Univ, Detroit, MI 48202 USA. CALTECH, Pasadena, CA 91125 USA. Univ Texas, Austin, TX 78712 USA. Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. BINP, RU-630090 Novosibirsk, Russia. Yonsei Univ, Seoul 120749, South Korea. Brookhaven Natl Lab, Upton, NY 11973 USA. RP Bliss, DW (reprint author), Univ Calif San Diego, La Jolla, CA 92093 USA. RI Briere, Roy/N-7819-2014; OI Briere, Roy/0000-0001-5229-1039; Bean, Alice/0000-0001-5967-8674; Poling, Ronald/0000-0001-7305-4702; Bloom, Kenneth/0000-0002-4272-8900 NR 26 TC 38 Z9 38 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 MAY 1 PY 1998 VL 57 IS 9 BP 5903 EP 5907 DI 10.1103/PhysRevD.57.5903 PG 5 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA ZL725 UT WOS:000073464200063 ER PT J AU Jaffe, RL Jin, XM Tang, J AF Jaffe, RL Jin, XM Tang, J TI Interference fragmentation functions and valence quark spin distributions in the nucleon SO PHYSICAL REVIEW D LA English DT Article ID DENSITIES AB We explore further applications of the twist-two quark interference fragmentation functions introduced earlier. We show that semi-inclusive production of two pions in the current fragmentation region in deep inelastic scattering of a longitudinally polarized electron on a longitudinally polarized nucleon can provide a probe of the valence quark spin (or helicity difference) distribution in the nucleon. C1 MIT, Ctr Theoret Phys, Nucl Sci Lab, Cambridge, MA 02139 USA. MIT, Dept Phys, Cambridge, MA 02139 USA. Brookhaven Natl Lab, Res Ctr, RIKEN, Upton, NY 11973 USA. RP Jaffe, RL (reprint author), MIT, Ctr Theoret Phys, Nucl Sci Lab, Cambridge, MA 02139 USA. NR 13 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 0556-2821 J9 PHYS REV D JI Phys. Rev. D PD MAY 1 PY 1998 VL 57 IS 9 BP 5920 EP 5922 DI 10.1103/PhysRevD.57.5920 PG 3 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA ZL725 UT WOS:000073464200067 ER PT J AU Dellago, C Hoover, WG Posch, HA AF Dellago, C Hoover, WG Posch, HA TI Isomorphic multifractal shear flows for hard disks via adiabatic and isokinetic nonequilibrium molecular dynamics SO PHYSICAL REVIEW E LA English DT Article ID LORENTZ GAS; DIMENSION AB Identical particle trajectories can result from driven shear flows of two different types: (i) thermostatted flows, simulating a nonequilibrium steady state, and (ii) adiabatic flows, in which the irreversible heating associated with viscous work is not extracted from the system. This trajectory isomorphism applies to shears of hard particles, such as hard disks and spheres. Here we simulate such isomorphic shear flows. We also discuss the associated instantaneous Lyapunov spectra, which are not isomorphic. We extrapolate the dissipative hard-disk spectra to the large-system limit. C1 Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. Univ Calif Davis, Dept Appl Sci, Livermore, CA 94551 USA. Univ Vienna, Inst Expt Phys, A-1090 Vienna, Austria. RP Dellago, C (reprint author), Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. RI Dellago, Christoph/E-1625-2011 NR 30 TC 6 Z9 6 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 MAY PY 1998 VL 57 IS 5 BP 4969 EP 4975 DI 10.1103/PhysRevE.57.4969 PN A PG 7 WC Physics, Fluids & Plasmas; Physics, Mathematical SC Physics GA ZP582 UT WOS:000073767900018 ER PT J AU Tammaro, M Evans, JW AF Tammaro, M Evans, JW TI Hydrodynamic limits for the monomer-dimer surface reaction: Chemical diffusion, wave propagation, and equistability SO PHYSICAL REVIEW E LA English DT Article ID KINETIC PHASE-TRANSITIONS; A-B(2) REACTION MODEL; LATTICE GAS; MEAN-FIELD; SIMULATIONS; DESORPTION; CATALYSIS; BEHAVIOR AB For finite adspecies mobility, the lattice-gas monomer-dimer (A+B-2) surface reaction model exhibits a discontinuous transition from a stable reactive steady state to a stable A-poisoned steady state, as the impingement rate P-A for A increases above a critical value P*. The reactive (poisoned) state is metastable for P-A just above (below) P*. Increasing the surface mobility of A enhances metastability, leading to bistability in the limit of high mobility. In the bistable region, the more stable state displaces the less stable one separated from it by a planar interface, with P* becoming the equistability point for the two states. This hydrodynamic regime can be described by reaction-diffusion equations (RDE's). However, for finite reaction rates, mixed adlayers of A and B are formed, resulting in a coverage-dependent and tensorial nature to chemical diffusion (even in the absence of interactions beyond site blocking). For equal mobility of adsorbed A and B, and finite reaction rate, the prediction for P* from such RDE's, incorporating the appropriate description of chemical diffusion, is shown to coincide with that from kinetic Monte Carlo simulations for the lattice-gas model in the regime of high mobility. Behavior for this special case is compared with that for various other prescriptions of mobility, for both finite and infinite reaction rates. C1 Univ Rhode Isl, Dept Phys, Kingston, RI 02881 USA. Iowa State Univ Sci & Technol, Ames Lab, Ames, IA 50011 USA. Iowa State Univ Sci & Technol, Dept Math, Ames, IA 50011 USA. RP Tammaro, M (reprint author), Univ Rhode Isl, Dept Phys, Kingston, RI 02881 USA. NR 34 TC 8 Z9 8 U1 0 U2 1 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1063-651X J9 PHYS REV E JI Phys. Rev. E PD MAY PY 1998 VL 57 IS 5 BP 5087 EP 5094 DI 10.1103/PhysRevE.57.5087 PN A PG 8 WC Physics, Fluids & Plasmas; Physics, Mathematical SC Physics GA ZP582 UT WOS:000073767900033 ER PT J AU Gunaratne, GH Hoffman, DK Kouri, DJ AF Gunaratne, GH Hoffman, DK Kouri, DJ TI Characterizations of natural patterns SO PHYSICAL REVIEW E LA English DT Article ID TRANSITION AB Labyrinthine patterns are observed in systems as diverse as animal coats, slime mold colonies, fish scales, and cloud streets. However, even under well-controlled conditions, repetition of an experiment gives structures with vastly different details. A theoretical analysis of "universal" aspects of patterns requires a quantitative description that gives similar values for distinct configurations. We introduce a function to characterize the "disorder" of labyrinthine patterns that is the same for structures generated under identical control parameters. Furthermore, patterns with different visual characteristics are described by distinct functions. 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. Univ Houston, Dept Chem, Houston, TX 77204 USA. RP Gunaratne, GH (reprint author), Univ Houston, Dept Phys, Houston, TX 77204 USA. EM gemunu@uh.edu; hoffman@gdynamic.ameslab.gov; kouri@uh.edu NR 21 TC 16 Z9 16 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 MAY PY 1998 VL 57 IS 5 BP 5146 EP 5149 DI 10.1103/PhysRevE.57.5146 PN A PG 4 WC Physics, Fluids & Plasmas; Physics, Mathematical SC Physics GA ZP582 UT WOS:000073767900040 ER PT J AU Aranson, IS Bishop, AR Kramer, L AF Aranson, IS Bishop, AR Kramer, L TI Dynamics of vortex lines in the three-dimensional complex Ginzburg-Landau equation: Instability, stretching, entanglement, and helices SO PHYSICAL REVIEW E LA English DT Article ID 3-DIMENSIONAL SCROLL WAVES; SPIRAL WAVES; OSCILLATORY MEDIA; EXCITABLE MEDIA; PATTERNS; STATES; RINGS AB The dynamics of curved vortex filaments is studied analytically and numerically in the framework of a three-dimensional complex Ginzburg-Landau equation (CGLE). It is shown that a straight vortex line is unstable with respect to spontaneous stretching and bending in a substantial range of parameters of the COLE, resulting in formation of persistent entangled vortex configurations. The boundary of the three-dimensional instability in parameter space is determined. Near the stability boundary, the supercritical saturation of the instability is found, resulting in the formation of stable helicoidal vortices. C1 Argonne Natl Lab, Argonne, IL 60439 USA. Bar Ilan Univ, Dept Phys, IL-52900 Ramat Gan, Israel. Univ Calif Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. Univ Calif Los Alamos Natl Lab, Ctr Nonlinear Studies, Los Alamos, NM 87545 USA. Univ Bayreuth, Dept Phys, D-95440 Bayreuth, Germany. RP Aranson, IS (reprint author), Argonne Natl Lab, 9700 S Cass Ave, Argonne, IL 60439 USA. RI Aranson, Igor/I-4060-2013 NR 35 TC 24 Z9 24 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 MAY PY 1998 VL 57 IS 5 BP 5276 EP 5286 DI 10.1103/PhysRevE.57.5276 PN A PG 11 WC Physics, Fluids & Plasmas; Physics, Mathematical SC Physics GA ZP582 UT WOS:000073767900058 ER PT J AU Kenkre, VM Scott, JE Pease, EA Hurd, AJ AF Kenkre, VM Scott, JE Pease, EA Hurd, AJ TI Nonlocal approach to the analysis of the stress distribution in granular systems. I. Theoretical framework SO PHYSICAL REVIEW E LA English DT Article ID FORCE FLUCTUATIONS; BEAD PACKS; MODEL; DYNAMICS; SAND AB A theoretical framework for the analysis of the stress distribution in granular materials is presented. It makes use of a transformation of the vertical spatial coordinate into a formal time variable and the subsequent study of a generally non-Markoffian, i.e., memory-possessing (nonlocal) propagation equation. Previous treatments are obtained as particular cases corresponding to, respectively, wavelike and diffusive limits of the general evolution. Calculations are presented for stress propagation in bounded and unbounded media. They can be used to obtain desired features such as a prescribed stress distribution within the compact. C1 Univ New Mexico, Dept Phys & Astron, Ctr Adv Studies, Albuquerque, NM 87131 USA. Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Kenkre, VM (reprint author), Univ New Mexico, Dept Phys & Astron, Ctr Adv Studies, Albuquerque, NM 87131 USA. NR 39 TC 15 Z9 15 U1 1 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 MAY PY 1998 VL 57 IS 5 BP 5841 EP 5849 DI 10.1103/PhysRevE.57.5841 PN B PG 9 WC Physics, Fluids & Plasmas; Physics, Mathematical SC Physics GA ZP583 UT WOS:000073768000046 ER PT J AU Scott, JE Kenkre, VM Hurd, AJ AF Scott, JE Kenkre, VM Hurd, AJ TI Nonlocal approach to the analysis of the stress distribution in granular systems. II. Application to experiment SO PHYSICAL REVIEW E LA English DT Article ID FORCE FLUCTUATIONS; BEAD PACKS; MODEL AB A theory of stress propagation in granular materials developed recently [Kenkre, Scott, Pease, and Hurd, preceding paper, Phys. Rev. E 57, 5841 (1998)] is applied to the compaction of ceramic and metal powders in pipes with previously unexplained experimental features such as nonmonotonic density and stress variation along the axis of cylindrical compacts. C1 Univ New Mexico, Dept Phys & Astron, Ctr Adv Studies, Albuquerque, NM 87131 USA. Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Scott, JE (reprint author), Univ New Mexico, Dept Phys & Astron, Ctr Adv Studies, Albuquerque, NM 87131 USA. NR 25 TC 10 Z9 10 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1063-651X J9 PHYS REV E JI Phys. Rev. E PD MAY PY 1998 VL 57 IS 5 BP 5850 EP 5857 DI 10.1103/PhysRevE.57.5850 PN B PG 8 WC Physics, Fluids & Plasmas; Physics, Mathematical SC Physics GA ZP583 UT WOS:000073768000047 ER PT J AU Decker, CD London, RA Harte, JA Powers, LV Trebes, JE AF Decker, CD London, RA Harte, JA Powers, LV Trebes, JE TI Electron-density measurements in hohlraums using soft-x-ray deflectometry SO PHYSICAL REVIEW E LA English DT Article ID LASER AB This paper presents design calculations for experiments that measure electron densities of laser heated hohlraums with soft-x-ray moire deflectometry. Hydrodynamical simulations of the hohlraums are analyzed to obtain deflection angles of the probing beam and x-ray emission from the hohlraum. The deflection angles and resulting moire fringe shifts and fringe contrast are predicted to be sufficient to infer electron-density gradients from measurements. In addition, the self-emission is found to be much lower than that of the probing laser beam, giving a good signal-to-noise ratio. In conclusion, moire deflectometry with soft-x-ray lasers has the potential to give valuable information about the electron density in laser driven hohlraums. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Decker, CD (reprint author), Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. NR 15 TC 4 Z9 4 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 MAY PY 1998 VL 57 IS 5 BP 5952 EP 5957 DI 10.1103/PhysRevE.57.5952 PN B PG 6 WC Physics, Fluids & Plasmas; Physics, Mathematical SC Physics GA ZP583 UT WOS:000073768000060 ER PT J AU Wrubel, T Ahmad, I Buscher, S Kunze, HJ Glenzer, SH AF Wrubel, T Ahmad, I Buscher, S Kunze, HJ Glenzer, SH TI Stark broadening along the berylliumlike sequence SO PHYSICAL REVIEW E LA English DT Article ID RAY SPECTROSCOPIC MEASUREMENTS; INERTIAL CONFINEMENT FUSION; ISOLATED ION LINES; SPECTRAL-LINES; ISOELECTRONIC SEQUENCE; LI-LIKE; TRANSITIONS; PROFILES; PLASMAS; GAIN AB We report on Stark width measurements of 2s3s-2s3p singlet and triplet transitions along the berylliumlike sequence performed in a gas-liner pinch discharge. Simultaneously with the spectroscopic measurements we have diagnosed the plasma with Thomson scattering testing theoretical scalings of the Stark broadening with density, temperature, and spectroscopic charge number Z. The comparison of measured Stark widths with semiclassical calculations shows that the calculated temperature scaling is consistent with the experiment. However, a systematic discrepancy of measured Stark widths from theoretically predicted Z(-2) scaling is found with increasing spectroscopic charge number Z. C1 Ruhr Univ Bochum, Inst Expt Phys 5, D-44780 Bochum, Germany. Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. Quaid I Azam Univ, Dept Phys, Islamabad, Pakistan. RP Ruhr Univ Bochum, Inst Expt Phys 5, D-44780 Bochum, Germany. NR 39 TC 20 Z9 20 U1 0 U2 1 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 MAY PY 1998 VL 57 IS 5 BP 5972 EP 5977 DI 10.1103/PhysRevE.57.5972 PN B PG 6 WC Physics, Fluids & Plasmas; Physics, Mathematical SC Physics GA ZP583 UT WOS:000073768000062 ER PT J AU Kang, HS Ree, FH AF Kang, HS Ree, FH TI Perturbative hypernetted-chain equation for mixtures: Applications to Coulomb plasma and H-2+H mixtures SO PHYSICAL REVIEW E LA English DT Article ID ONE-COMPONENT-PLASMA; INTEGRAL-EQUATION; PHASE-SEPARATION; IONIC MIXTURES; YUKAWA SYSTEMS; STATE; SIMULATION; DENSITY; LIMIT; MODEL AB The perturbative hypernetted-chain equation for one-component systems [J. Chem. Phys. 103, 9377 (1995)] has been extended to mixture systems by approximating the bridge function of a system by that of a reference system whose repulsive range is chosen to satisfy thermodynamic consistency of partial isothermal compressibilities for individual components in a mixture. Applications to strongly coupled Coulomb and Yukawa mixtures and H+H-2 mixtures show that the theory provides radial distribution functions and thermodynamic functions that are in close agreement with exact computer-simulation data, some of which are obtained in this work. They are often superior to or at least comparable to the best available theories in the literature. C1 Jeonju Univ, Coll Sci & Engn, Dept Chem New Mat, Wansan Ku, Chonju 560759, Chonbuk, South Korea. Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. RP Kang, HS (reprint author), Jeonju Univ, Coll Sci & Engn, Dept Chem New Mat, Wansan Ku, Hyoja Dong, Chonju 560759, Chonbuk, South Korea. NR 18 TC 6 Z9 6 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 MAY PY 1998 VL 57 IS 5 BP 5988 EP 5992 DI 10.1103/PhysRevE.57.5988 PN B PG 5 WC Physics, Fluids & Plasmas; Physics, Mathematical SC Physics GA ZP583 UT WOS:000073768000064 ER PT J AU Babzien, M Ben-Zvi, I Catravas, P Fang, JM Marshall, TC Wang, XJ Wurtele, JS Yakimenko, V Yu, LH AF Babzien, M Ben-Zvi, I Catravas, P Fang, JM Marshall, TC Wang, XJ Wurtele, JS Yakimenko, V Yu, LH TI Observation of self-amplified spontaneous emission in the near-infrared and visible wavelengths SO PHYSICAL REVIEW E LA English DT Article ID FREE-ELECTRON-LASER; SCALING FUNCTION; MU-M; MICROWIGGLER; POWER; BUNCH; BEAMS; GAIN AB We report evidence of self-amplified spontaneous emission (SASE) at 1064 and 633 nm. To our knowledge, these are the first measurements of SASE at such a short wavelength and employ the smallest period wiggler, 8.8 mm, used to date in a successful SASE experiment. The experiments were performed with the MIT microwiggler at the Accelerator Test Facility at BNL. Single-pass, on-axis microwiggler emissions within a 25 nm bandwidth have been recorded as a function of beam charge and show a clear enhancement over spontaneous emission. For the measurement at 1064 nm, a single micropulse at 34 MeV with a variable charge of 0-1 nC and less than 5 ps full width at half maximum bunch length was passed through the microwiggler and emissions into a limited solid angle and bandwidth, selected by an aperture and interference filter, were focused onto a silicon photodiode. Enhancement of the emissions, from 2 to 6 times the spontaneous emission level, was observed at the highest charges. In addition, we observed SASE gain at a wavelength of 633 nm at a beam energy of 48 MeV, without detailed measurements. C1 Brookhaven Natl Lab, Natl Synchrotron Light Source, Upton, NY 11973 USA. MIT, Cambridge, MA 02139 USA. Columbia Univ, Dept Appl Phys, New York, NY 10027 USA. Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. RP Babzien, M (reprint author), Brookhaven Natl Lab, Natl Synchrotron Light Source, Upton, NY 11973 USA. RI wurtele, Jonathan/J-6278-2016 OI wurtele, Jonathan/0000-0001-8401-0297 NR 28 TC 36 Z9 37 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 MAY PY 1998 VL 57 IS 5 BP 6093 EP 6100 DI 10.1103/PhysRevE.57.6093 PN B PG 8 WC Physics, Fluids & Plasmas; Physics, Mathematical SC Physics GA ZP583 UT WOS:000073768000078 ER PT J AU More, RM Kosaka, K AF More, RM Kosaka, K TI Wave-front curvature in geometrical optics SO PHYSICAL REVIEW E LA English DT Article AB This paper develops a general method for calculation of the intensity of light propagating in a medium whose refractive index iz(r) varies slowly with position, based on a differential equation for the curvature of wave fronts. The equation can be integrated along rays, one ray at a time, and gives the changes of intensity caused by convergence or divergence of the rays. An explicit solution is obtained for light in a cylindrically symmetric medium having a linear density gradient. Applied to wave mechanics, the method gives a local semiclassical solution of the three-dimensional Schrodinger equation in a form especially suitable for treatment of collisions. We examine the possibility of extending the method to nonlinear optics. C1 Okayama Univ, Dept Phys, Okayama 700, Japan. Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP More, RM (reprint author), Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. NR 13 TC 2 Z9 2 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 MAY PY 1998 VL 57 IS 5 BP 6127 EP 6134 DI 10.1103/PhysRevE.57.6127 PN B PG 8 WC Physics, Fluids & Plasmas; Physics, Mathematical SC Physics GA ZP583 UT WOS:000073768000082 ER PT J AU Hoffman, DK Wei, GW Zhang, DS Kouri, DJ AF Hoffman, DK Wei, GW Zhang, DS Kouri, DJ TI Interpolating distributed approximating functionals SO PHYSICAL REVIEW E LA English DT Article ID LIPPMANN-SCHWINGER EQUATIONS; POTENTIAL-ENERGY SURFACES; DISCRETE-ORDINATE METHOD; FOKKER-PLANCK EQUATIONS; SCHRODINGER-EQUATION; QUANTUM DYNAMICS; INVERSE METHOD; EIGENFUNCTIONS; SCATTERING; PROPAGATOR AB In this paper, we present a class of distributed approximating functionals (DAF's) for solving various problems in thr sciences and engineering. Previous DAF's were specifically constructed to avoid interpolation in order to achieve the "well-tempered" limit, in which the same order error is made both on and off the grid points. These DAF's are constructed by combining the DAF concept with various interpolation schemes. The approach then becomes the same as the "moving least squares" method, but the specific "interpolating DAF's" obtained are new, to our knowledge. These interpolating DAF's are illustrated using Lagrange interpolation (the "LDAF") and a Gaussian weight function. Four numerical tests are used to illustrate the LDAF's: differentiation on and off a grid, fitting a function off a grid, time-dependent quantum dynamical evolution, and solving nonlinear Burgers' equation. C1 Iowa State Univ Sci & Technol, Dept Chem, Ames, IA 50011 USA. Iowa State Univ Sci & Technol, Ames Lab, Ames, IA 50011 USA. Univ Houston, Dept Chem, Houston, TX 77204 USA. Univ Houston, Dept Phys, Houston, TX 77204 USA. RP Hoffman, DK (reprint author), Iowa State Univ Sci & Technol, Dept Chem, Ames, IA 50011 USA. RI Wei, Guowei /E-1852-2011 NR 64 TC 26 Z9 26 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 MAY PY 1998 VL 57 IS 5 BP 6152 EP 6160 DI 10.1103/PhysRevE.57.6152 PN B PG 9 WC Physics, Fluids & Plasmas; Physics, Mathematical SC Physics GA ZP583 UT WOS:000073768000085 ER PT J AU Josef, JA Morel, JE AF Josef, JA Morel, JE TI Simplified spherical harmonic method for coupled electron-photon transport calculations SO PHYSICAL REVIEW E LA English DT Article ID ANISOTROPIC SCATTERING; ACCELERATION TECHNIQUE; SN EQUATIONS; N EQUATIONS AB In this paper we apply the simplified spherical harmonic (SPN) approximation to coupled electron-photon transport problems in two-dimensional cylindrical geometry in the energy range from roughly 10 keV to 10 MeV. The SPN equations represent an asymptotic approximation that does not necessarily converge to the exact transport solution as N-->infinity, but can sometimes produce solutions that are much more accurate than diffusion theory at a fraction of the cost of a full transport treatment. To our knowledge, the SPN approximation has previously been applied only to neutron transport problems. We investigate the applicability of the SPN method to satellite electronics shielding calculations. In addition to applying the approximation, we generalize certain iterative convergence acceleration techniques originally developed for the one-dimensional S-N (discrete ordinates) equations, and apply them to the two-dimensional SPN equations. We present numerical comparisons with Monte Carlo calculations for the purpose of examining both the accuracy of the SPN approximation and the computational efficiency of our solution techniques. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Josef, JA (reprint author), Univ Calif Los Alamos Natl Lab, MS D409, Los Alamos, NM 87545 USA. NR 26 TC 10 Z9 10 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 MAY PY 1998 VL 57 IS 5 BP 6161 EP 6171 DI 10.1103/PhysRevE.57.6161 PN B PG 11 WC Physics, Fluids & Plasmas; Physics, Mathematical SC Physics GA ZP583 UT WOS:000073768000086 ER PT J AU Myers, SA Cygan, RT Assink, RA Boslough, MB AF Myers, SA Cygan, RT Assink, RA Boslough, MB TI Si-29 MAS NMR relaxation study of shocked Coconino sandstone from Meteor Crater, Arizona SO PHYSICS AND CHEMISTRY OF MINERALS LA English DT Article ID NUCLEAR MAGNETIC-RESONANCE; SILICA POLYMORPHS; SPECTROSCOPY AB Si-29 nuclear magnetic resonance (NMR) spectroscopy was used to characterize the silica phases in a moderately-shocked Coconino sandstone from Meteor Crater, Arizona. The spectra were recorded using direct polarization, magic-angle spinning, and variable delay times in a saturation recovery pulse sequence. Resonances observed at -97.3, -107.1, -113.9 and -191.2 ppm were assigned to a densified hydrous form of amorphous silica (D phase), quartz, coesite and stishovite phases, respectively. The relative percentages were estimated as 1.7, 80.6. 16.4 and 1.3% for the D, quartz, coesite, and stishovite phases. The power-law recoveries of the magnetization for the quartz and coesite phases can be interpreted in terms of their phase geometries. C1 Sandia Natl Labs, Dept Geochem, Albuquerque, NM 87185 USA. RP Cygan, RT (reprint author), Sandia Natl Labs, Dept Geochem, POB 5800, Albuquerque, NM 87185 USA. NR 17 TC 7 Z9 7 U1 0 U2 4 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 USA SN 0342-1791 J9 PHYS CHEM MINER JI Phys. Chem. Miner. PD MAY PY 1998 VL 25 IS 5 BP 313 EP 317 DI 10.1007/s002690050120 PG 5 WC Materials Science, Multidisciplinary; Mineralogy SC Materials Science; Mineralogy GA ZR063 UT WOS:000073931900001 ER PT J AU Hielscher, AH Alcouffe, RE Barbour, RL AF Hielscher, AH Alcouffe, RE Barbour, RL TI Comparison of finite-difference transport and diffusion calculations for photon migration in homogeneous and heterogeneous tissues SO PHYSICS IN MEDICINE AND BIOLOGY LA English DT Article ID SYNTHETIC ACCELERATION METHODS; DISCRETE-ORDINATES EQUATIONS; TIME-RESOLVED REFLECTANCE; BENIGN PROSTATIC HYPERPLASIA; NEAR-INFRARED SPECTROSCOPY; OPTICAL-PROPERTIES; INTRACRANIAL HEMATOMAS; TURBID MEDIA; MONTE-CARLO; ABSORPTION-COEFFICIENTS AB We analyse the limits of the diffusion approximation to the time-independent equation of radiative transfer for homogeneous and heterogeneous biological media. Analytical calculations and finite-difference simulations based on diffusion theory are compared with discrete-ordinate, finite-difference transport calculations. The influence of the ratio of absorption and transport scattering coefficient (mu(a)/mu'(s)) on the accuracy of the diffusion approximation are quantified and different definitions for the diffusion coefficient, D, are discussed. We also address effects caused by void-like heterogeneities in which absorption and scattering are very small compared with the surrounding medium. Based on results for simple homogeneous and heterogeneous systems, we analyse diffusion and transport calculation of light propagation in the human brain. For these simulations we convert density maps obtained from magnetic resonance imaging (MRI) to optical-parameter maps (mu, and mu'(s)) of the brain. We show that diffusion theory fails to describe accurately light propagation in highly absorbing regions, such as haematoma, and void-like spaces, such as the ventricles and the subarachnoid space. C1 Univ Calif Los Alamos Natl Lab, CST 4, Los Alamos, NM 87545 USA. Univ Calif Los Alamos Natl Lab, XTM, Los Alamos, NM 87545 USA. SUNY Hlth Sci Ctr, Dept Pathol, Brooklyn, NY 11203 USA. RP Hielscher, AH (reprint author), Univ Calif Los Alamos Natl Lab, CST 4, MS E535, Los Alamos, NM 87545 USA. FU NCI NIH HHS [CA66184-A02] NR 62 TC 209 Z9 211 U1 1 U2 11 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0031-9155 J9 PHYS MED BIOL JI Phys. Med. Biol. PD MAY PY 1998 VL 43 IS 5 BP 1285 EP 1302 DI 10.1088/0031-9155/43/5/017 PG 18 WC Engineering, Biomedical; Radiology, Nuclear Medicine & Medical Imaging SC Engineering; Radiology, Nuclear Medicine & Medical Imaging GA ZQ134 UT WOS:000073825700017 PM 9623656 ER PT J AU Boldyrev, S AF Boldyrev, S TI Nonlinear magnetosonic waves in a multi-ion-species plasma SO PHYSICS OF PLASMAS LA English DT Article ID 2-ION-SPECIES PLASMA; ACOUSTIC TURBULENCE AB Magnetosonic waves are intensively studied-due to their importance in space plasmas and also in fusion plasmas where they are used in particle acceleration and heating experiments. In the present paper, the magnetosonic waves propagating in a multi-ion-species plasma perpendicular to an external magnetic field are investigated. Due to the presence of several ion species, this mode splits into two branches: high-and low-frequency modes. This opens a new channel of nonlinear interactions (between these two modes), and qualitatively changes the picture of turbulence in the long-wave region. Considering the limit of a cold collisionless plasma, a general system describing the propagation of nonlinearly coupled high-and low-frequency waves is derived. This system includes the Korteweg-de Vries (KdV), Boussinesq, and Zakharov equations as Limiting cases. Solitary solutions of the system of coupled equations are obtained. (C) 1998 American Institute of Physics. C1 Princeton Plasma Phys Lab, Princeton, NJ 08543 USA. RP Boldyrev, S (reprint author), Princeton Plasma Phys Lab, POB 451, Princeton, NJ 08543 USA. NR 14 TC 15 Z9 15 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 1070-664X J9 PHYS PLASMAS JI Phys. Plasmas PD MAY PY 1998 VL 5 IS 5 BP 1315 EP 1320 DI 10.1063/1.872790 PN 1 PG 6 WC Physics, Fluids & Plasmas SC Physics GA ZM871 UT WOS:000073584700011 ER PT J AU Gorelenkova, MV Gorelenkov, NN Azizov, EA Romannikov, AN Herrmann, HW AF Gorelenkova, MV Gorelenkov, NN Azizov, EA Romannikov, AN Herrmann, HW TI Kinetic theory of plasma adiabatic major radius compression in tokamaks SO PHYSICS OF PLASMAS LA English DT Article AB In order to understand the individual charged particle behavior as well as plasma macroparameters (temperature, density, etc.) during the adiabatic major radius compression (R-compression) in a tokamak, a kinetic approach is used. The perpendicular electric field from the Ohm's law at zero resistivity is made use of in order to describe particle motion during the R-compression. Expressions for both passing and trapped particle energy and pitch angle change are derived for a plasma with high aspect ratio and circular magnetic surfaces. The particle behavior near the passing trapped boundary during the compression is studied to simulate the compression-induced collisional losses of alpha particles. Qualitative agreement is obtained with the alphas loss measurements in deuterium-tritium (D-T) experiments in the Tokamak Fusion Test Reactor (TFTR) [World Survey of Activities in Controlled Fusion Research [Nucl. Fusion special supplement (1991)] (Internation at Atomic Energy Agency, Vienna, 1991)]. The plasma macroparameters evolution at the R-compression is calculated by solving the gyroaveraged drift kinetic equation. (C) 1998 American Institute of Physics. C1 Troitsk Inst Innovat & Fus Res, Troitsk 142092, Moscow Region, Russia. Princeton Plasma Phys Lab, Princeton, NJ 08543 USA. RP Gorelenkova, MV (reprint author), Troitsk Inst Innovat & Fus Res, Troitsk 142092, Moscow Region, Russia. NR 16 TC 1 Z9 1 U1 1 U2 2 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 1070-664X J9 PHYS PLASMAS JI Phys. Plasmas PD MAY PY 1998 VL 5 IS 5 BP 1345 EP 1353 DI 10.1063/1.872794 PN 1 PG 9 WC Physics, Fluids & Plasmas SC Physics GA ZM871 UT WOS:000073584700015 ER PT J AU Porter, GD Moller, J Brown, M Lasnier, C AF Porter, GD Moller, J Brown, M Lasnier, C CA DIII-D Team TI Characterization of the separatrix plasma parameters in DIII-D SO PHYSICS OF PLASMAS LA English DT Article ID TOKAMAK AB Characterization of the plasma density and temperature at the last closed flux surface (the separatrix) of a tokamak requires accurate knowledge of the location of the separatrix. In this paper we discuss the effect of inaccuracy in the separatrix location on the measured parameters in DI-II-D [Luxon et al., International Conference on Plasma Physics and Controlled Nuclear Fusion (International Atomic Energy Agency, Vienna, 1986), p. 159] An uncertainty in the separatrix position of +/- 0.5 cm, as expected in this device using magnetic reconstruction to determine the location of the separatrix, leads to unacceptably large uncertainty in the plasma parameters. Several techniques to improve the accuracy obtained from magnetic reconstruction are discussed. A new technique that is based on a characterization of the electron temperature profile is proposed. A comparison of the separatrix location defined in this manner with that obtained using magnetic reconstruction techniques suggests a systematic error in the reconstruction when the plasma is far from the walls and magnetic diagnostics. Determination of the perpendicular transport coefficients is given as an example of the improved statistics obtained using the new technique of defining the separatrix position. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. Gen Atom, San Diego, CA 92121 USA. RP Porter, GD (reprint author), Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. NR 12 TC 26 Z9 26 U1 0 U2 3 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 1070-664X J9 PHYS PLASMAS JI Phys. Plasmas PD MAY PY 1998 VL 5 IS 5 BP 1410 EP 1422 DI 10.1063/1.872830 PN 1 PG 13 WC Physics, Fluids & Plasmas SC Physics GA ZM871 UT WOS:000073584700022 ER PT J AU Giacone, RE Vu, HX AF Giacone, RE Vu, HX TI Nonlinear kinetic simulations of stimulated Brillouin scattering SO PHYSICS OF PLASMAS LA English DT Article ID ION-ACOUSTIC-WAVES; LONG-SCALE-LENGTH; LASER HOT-SPOTS; PARAMETRIC-INSTABILITIES; PLASMAS; BACKSCATTER AB Numerical simulation results of stimulated Brillouin scattering (SBS) using HERCULES [H. X. Vu, J. Comput. Phys. 124, 417 (1996)], an adiabatic fluid-electron particle-in-cell (PIC) code, are presented. The results of these PIC simulations are compared against fluid simulations, and good agreement is obtained for sufficiently weak laser intensities. When the laser intensity is sufficiently strong for ion trapping to be significant, PIC and fluid simulations differ substantially. The trapping time and nonlinear frequency shift obtained in the PIC simulations are in good agreement with analytical predictions. The SBS reflectivity is shown to be very sensitive to frequency mismatch between the light wave used to seed the instability and the incident laser. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Giacone, RE (reprint author), Univ Calif Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. NR 17 TC 28 Z9 28 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 1070-664X J9 PHYS PLASMAS JI Phys. Plasmas PD MAY PY 1998 VL 5 IS 5 BP 1455 EP 1460 DI 10.1063/1.872803 PN 1 PG 6 WC Physics, Fluids & Plasmas SC Physics GA ZM871 UT WOS:000073584700025 ER PT J AU Rose, HA Ghosal, S AF Rose, HA Ghosal, S TI Nonlinear theory of power transfer between multiple crossed laser beams in a flowing plasma SO PHYSICS OF PLASMAS LA English DT Article ID RANDOM-PHASE PLATE; ENERGY-TRANSFER; HOT-SPOTS; DEFLECTION AB Analytic results are obtained for power transfer among crossing, equal frequency, laser beams, each smoothed by a random phase plate, in a flowing homogeneous plasma. For beams with well-separated directions, interbeam coupling transfers power, while intrabeam coupling causes beam deflection. For any pair of such beams, the beam with the largest positive projection on the flow direction will drain power from the other. (C) 1998 American Institute of Physics. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Rose, HA (reprint author), Univ Calif Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. RI Ghosal, Sandip/A-3534-2009; Ghosal, Sandip/B-7595-2009 OI Ghosal, Sandip/0000-0001-6587-3716; NR 12 TC 19 Z9 19 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 1070-664X J9 PHYS PLASMAS JI Phys. Plasmas PD MAY PY 1998 VL 5 IS 5 BP 1461 EP 1466 DI 10.1063/1.872804 PN 1 PG 6 WC Physics, Fluids & Plasmas SC Physics GA ZM871 UT WOS:000073584700026 ER PT J AU Roderick, NF Peterkin, RE Hussey, TW Spielman, RB Douglas, MR Deeney, C AF Roderick, NF Peterkin, RE Hussey, TW Spielman, RB Douglas, MR Deeney, C TI Hydromagnetic Rayleigh-Taylor instability in high-velocity gas-puff implosions SO PHYSICS OF PLASMAS LA English DT Article ID IMPLODING PLASMA LINERS; Z-PINCHES; SUPPRESSION; STABILITY AB Experiments using the Saturn pulsed power generator have produced high-velocity z-pinch plasma implosions with velocities over 100 cm/mu s using both annular and uniform-fill gas injection initial conditions. Both types of implosion show evidence of the hydromagnetic Rayleigh-Taylor instability with the uniform-fill plasmas producing a more spatially uniform pinch. Two-dimensional magnetohydrodynamic simulations including unsteady flow of gas from a nozzle into the diode region have been used to investigate these implosions. The instability develops from the nonuniform gas flow held that forms as the gas expands from the injection nozzle. Instability growth is limited to the narrow unstable region of the current sheath. For, the annular puff the unstable region breaks through the inner edge of the annulus increasing nonlinear growth as mass ejected from the bubble regions is not replenished by accretion. This higher growth leads to bubble thinning and disruption producing greater nonuniformity at pinch for the annular puff. The uniform puff provides gas to replenish bubble mass loss until just before pinch resulting in less bubble thinning and a more uniform pinch. C1 USAF, Res Lab, Kirtland AFB, NM 87117 USA. Sandia Natl Labs, Albuquerque, NM 87185 USA. Univ New Mexico, Dept Chem & Nucl Engn, Albuquerque, NM 87131 USA. RP Roderick, NF (reprint author), USAF, Res Lab, Phillips Site, Kirtland AFB, NM 87117 USA. NR 35 TC 19 Z9 20 U1 0 U2 3 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 1070-664X J9 PHYS PLASMAS JI Phys. Plasmas PD MAY PY 1998 VL 5 IS 5 BP 1477 EP 1484 DI 10.1063/1.872806 PN 1 PG 8 WC Physics, Fluids & Plasmas SC Physics GA ZM871 UT WOS:000073584700028 ER PT J AU Hawryluk, RJ Batha, S Blanchard, W Beer, M Bell, MG Bell, RE Berk, H Bernabei, S Bitter, M Breizman, B Bretz, NL Budny, R Bush, CE Callen, J Camp, R Cauffman, S Chang, Z Cheng, CZ Darrow, DS Dendy, RO Dorland, W Duong, H Efthimion, PC Ernst, D Fisch, NJ Fisher, R Fonck, RJ Fredrickson, ED Fu, GY Furth, HP Gorelenkov, NN Grek, B Grisham, LR Hammett, GW Hanson, GR Herrmann, HW Herrmann, MC Hill, KW Hogan, J Hosea, JC Houlberg, WA Hughes, M Hulse, RA Jassby, DL Jobes, FC Johnson, DW Kaita, R Kaye, S Kim, JS Kissick, M Krasilnikov, AV Kugel, H Kumar, A Leblanc, B Levinton, FM Ludescher, C Majeski, RP Manickam, J Mansfield, DK Mazzucato, E McChesney, J McCune, DC McGuire, KM Meade, DM Medley, SS Mika, R Mikkelsen, DR Mirnov, SV Mueller, D Nagy, A Navratil, GA Nazikian, R Okabayashi, M Park, HK Park, W Paul, SF Pearson, G Petrov, MP Phillips, CK Phillips, M Ramsey, AT Redi, MH Rewoldt, G Reznik, S Roquemore, AL Rogers, J Ruskov, E Sabbagh, SA Sasao, M Schilling, G Schivell, J Schmidt, GL Scott, SD Semenov, I Skinner, CH Stevenson, T Stratton, BC Strachan, JD Stodiek, W Synakowski, E Takahashi, H Tang, W Taylor, G Thompson, ME Von Goeler, S Von Halle, A Walters, RT White, R Wieland, RM Williams, M Wilson, JR Wong, KL Wurden, GA Yamada, M Yavorski, V Young, KM Zakharov, L Zarnstorff, MC Zweben, SJ AF Hawryluk, RJ Batha, S Blanchard, W Beer, M Bell, MG Bell, RE Berk, H Bernabei, S Bitter, M Breizman, B Bretz, NL Budny, R Bush, CE Callen, J Camp, R Cauffman, S Chang, Z Cheng, CZ Darrow, DS Dendy, RO Dorland, W Duong, H Efthimion, PC Ernst, D Fisch, NJ Fisher, R Fonck, RJ Fredrickson, ED Fu, GY Furth, HP Gorelenkov, NN Grek, B Grisham, LR Hammett, GW Hanson, GR Herrmann, HW Herrmann, MC Hill, KW Hogan, J Hosea, JC Houlberg, WA Hughes, M Hulse, RA Jassby, DL Jobes, FC Johnson, DW Kaita, R Kaye, S Kim, JS Kissick, M Krasilnikov, AV Kugel, H Kumar, A Leblanc, B Levinton, FM Ludescher, C Majeski, RP Manickam, J Mansfield, DK Mazzucato, E McChesney, J McCune, DC McGuire, KM Meade, DM Medley, SS Mika, R Mikkelsen, DR Mirnov, SV Mueller, D Nagy, A Navratil, GA Nazikian, R Okabayashi, M Park, HK Park, W Paul, SF Pearson, G Petrov, MP Phillips, CK Phillips, M Ramsey, AT Redi, MH Rewoldt, G Reznik, S Roquemore, AL Rogers, J Ruskov, E Sabbagh, SA Sasao, M Schilling, G Schivell, J Schmidt, GL Scott, SD Semenov, I Skinner, CH Stevenson, T Stratton, BC Strachan, JD Stodiek, W Synakowski, E Takahashi, H Tang, W Taylor, G Thompson, ME Von Goeler, S Von Halle, A Walters, RT White, R Wieland, RM Williams, M Wilson, JR Wong, KL Wurden, GA Yamada, M Yavorski, V Young, KM Zakharov, L Zarnstorff, MC Zweben, SJ TI Fusion plasma experiments on TFTR: A 20 year retrospective SO PHYSICS OF PLASMAS LA English DT Article; Proceedings Paper CT 39th Annual Meeting of the Division-of-Plasma-Physics of the American-Physical-Society CY NOV 17-21, 1997 CL PITTSBURGH, PENNSYLVANIA SP Amer Phys Soc, Div Plasma Phys ID REVERSED MAGNETIC SHEAR; TEST-REACTOR; ENERGY CONFINEMENT; TOKAMAK PLASMAS; TRANSPORT; DEUTERIUM; TRITIUM; STABILITY; HELIUM; MODES AB The Tokamak Fusion Test Reactor (TFTR) (R. J. Hawryluk, to be published in Rev. Mod. Phys.) experiments on high-temperature plasmas, that culminated in the study of deuterium-tritium D-T plasmas containing significant populations of energetic alpha particles, spanned over two decades from conception to completion. During the design of TFTR, the key physics issues were magnetohydrodynamic (MHD) equilibrium and stability, plasma energy transport, impurity effects, and plasma reactivity. Energetic particle physics was given less attention during this phase because, in part, of the necessity to address the issues that would create the conditions for the study of energetic particles and also the lack of diagnostics to study the energetic particles in detail. The worldwide tokamak program including the contributions from TFTR made substantial progress during the past two decades in addressing the fundamental issues affecting the performance of high-temperature plasmas and the behavior of energetic particles. The progress has been the result of the construction of new facilities, which enabled the production of high-temperature well-confined plasmas, development of sophisticated diagnostic techniques to study both the background plasma and the resulting energetic fusion products, and computational techniques to both interpret the experimental results and to predict the outcome of experiments. (C) 1998 American Institute of Physics. C1 Princeton Univ, Plasma Phys Lab, Princeton, NJ 08543 USA. Fus Phys & Technol, Torrance, CA 90503 USA. Univ Texas, Inst Fus Studies, Austin, TX 78712 USA. Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. Univ Wisconsin, Madison, WI 53706 USA. Culham Lab, Oxford OX14 30B, England. MIT, Cambridge, MA 02139 USA. Troitsk Inst Innovat & Thermonucl Res, Moscow 142092, Russia. Northrop Grumman Corp, Princeton, NJ 08544 USA. Univ Calif Los Angeles, Los Angeles, CA 90095 USA. Columbia Univ, New York, NY 10027 USA. AF Ioffe Phys Tech Inst, St Petersburg 194021, Russia. RP Hawryluk, RJ (reprint author), Princeton Univ, Plasma Phys Lab, POB 451, Princeton, NJ 08543 USA. RI Sabbagh, Steven/C-7142-2011; Hammett, Gregory/D-1365-2011; Ernst, Darin/A-1487-2010; Dendy, Richard/A-4533-2009; Dorland, William/B-4403-2009; White, Roscoe/D-1773-2013; Cheng, Chio/K-1005-2014; Yamada, Masaaki/D-7824-2015; Wurden, Glen/A-1921-2017 OI Hammett, Gregory/0000-0003-1495-6647; Ernst, Darin/0000-0002-9577-2809; Dorland, William/0000-0003-2915-724X; White, Roscoe/0000-0002-4239-2685; Yamada, Masaaki/0000-0003-4996-1649; Wurden, Glen/0000-0003-2991-1484 NR 80 TC 57 Z9 57 U1 1 U2 13 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 1070-664X J9 PHYS PLASMAS JI Phys. Plasmas PD MAY PY 1998 VL 5 IS 5 SI SI BP 1577 EP 1589 DI 10.1063/1.872825 PN 2 PG 13 WC Physics, Fluids & Plasmas SC Physics GA ZN238 UT WOS:000073623700002 ER PT J AU Caryotakis, G AF Caryotakis, G TI The klystron: A microwave source of surprising range and endurance SO PHYSICS OF PLASMAS LA English DT Article; Proceedings Paper CT 39th Annual Meeting of the Division-of-Plasma-Physics of the American-Physical-Society CY NOV 17-21, 1997 CL PITTSBURGH, PENNSYLVANIA SP Amer Phys Soc, Div Plasma Phys AB This year marks the 60th anniversary of the birth of the klystron at Stanford University. The tube was the first practical source of microwaves and its invention initiated a search for increasingly more powerful sources, which continues to this day. This paper reviews the scientific uses of the klystron and outlines its operating principles. The history of the device is traced from its scientific beginnings to its role in WWII and the Cold War, its subsequent decline in use for military systems, and to its current resurgence as the key component in a major accelerator project. Finally, the paper describes the development of a modular klystron, which may someday power future accelerators at millimeter wavelengths. (C) 1998 American Institute of Physics. C1 Stanford Univ, Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. RP Caryotakis, G (reprint author), Stanford Univ, Stanford Linear Accelerator Ctr, POB 4349, Stanford, CA 94309 USA. NR 28 TC 19 Z9 19 U1 5 U2 5 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 1070-664X J9 PHYS PLASMAS JI Phys. Plasmas PD MAY PY 1998 VL 5 IS 5 SI SI BP 1590 EP 1598 DI 10.1063/1.872826 PN 2 PG 9 WC Physics, Fluids & Plasmas SC Physics GA ZN238 UT WOS:000073623700003 ER PT J AU Kulsrud, RM AF Kulsrud, RM TI Magnetic reconnection in a magnetohydrodynamic plasma SO PHYSICS OF PLASMAS LA English DT Article; Proceedings Paper CT 39th Annual Meeting of the Division-of-Plasma-Physics of the American-Physical-Society CY NOV 17-21, 1997 CL PITTSBURGH, PENNSYLVANIA SP Amer Phys Soc, Div Plasma Phys ID RE-CONNEXION AB Magnetic reconnection is important because of its connection with the topology of held lines. In general, a change in topology means a change of equilibrium, and a release of energy, such as occurs in solar flares. In the context of the solar flare two models for magnetic reconnection, the Sweet-Parker and the Petschek mechanism are presented. The pros and cons of these two models are presented. The role of anomalous resistivity in the Sweet-Parker model is discussed. The bearing of a laboratory experiment and a boundary layer analysis of the problem are described. (C) 1998 American Institute of Physics. C1 Princeton Plasma Phys Lab, Princeton, NJ 08543 USA. RP Kulsrud, RM (reprint author), Princeton Plasma Phys Lab, POB 451,MS 27,James Forrestal Campus, Princeton, NJ 08543 USA. NR 21 TC 59 Z9 60 U1 0 U2 1 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 1070-664X J9 PHYS PLASMAS JI Phys. Plasmas PD MAY PY 1998 VL 5 IS 5 SI SI BP 1599 EP 1606 DI 10.1063/1.872827 PN 2 PG 8 WC Physics, Fluids & Plasmas SC Physics GA ZN238 UT WOS:000073623700004 ER PT J AU Leemans, WP Volfbeyn, P Guo, KZ Chattopadhyay, S Schroeder, CB Shadwick, BA Lee, PB Wurtele, JS Esarey, E AF Leemans, WP Volfbeyn, P Guo, KZ Chattopadhyay, S Schroeder, CB Shadwick, BA Lee, PB Wurtele, JS Esarey, E TI Laser-driven plasma-based accelerators: Wakefield excitation, channel guiding, and laser triggered particle injection SO PHYSICS OF PLASMAS LA English DT Article; Proceedings Paper CT 39th Annual Meeting of the Division-of-Plasma-Physics of the American-Physical-Society CY NOV 17-21, 1997 CL PITTSBURGH, PENNSYLVANIA SP Amer Phys Soc, Div Plasma Phys ID COLD INHOMOGENEOUS PLASMA; WAKE-FIELD ACCELERATION; UNDERDENSE PLASMAS; ELECTROSTATIC OSCILLATIONS; EQUATION APPROACH; SELF-MODULATION; PULSE; INTENSE; WAVES; PROPAGATION AB Plasma-based accelerators are discussed in which high-power short pulse lasers are the power source, suitably tailored plasma structures provide guiding of the laser beam and support large accelerating gradients, and an optical scheme is used to produce time-synchronized ultrashort electron bunches. From scaling laws laser requirements are obtained for development of compact high-energy accelerators. Simulation results of laser guiding and wakefield excitation in plasma channels, as well as laser-based injection of particles into a plasma wake, are presented. Details of the experimental program at Lawrence Berkeley National Laboratory on laser guiding, laser wakefield-based accelerators, and laser triggered injection are given. C1 Univ Calif Berkeley, Ernest Orlando Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. Univ Calif Berkeley, Berkeley, CA 94720 USA. USN, Res Lab, Washington, DC 20375 USA. RP Leemans, WP (reprint author), Univ Calif Berkeley, Ernest Orlando Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. EM leemans@lbl.gov RI wurtele, Jonathan/J-6278-2016; OI wurtele, Jonathan/0000-0001-8401-0297; Schroeder, Carl/0000-0002-9610-0166 NR 58 TC 57 Z9 57 U1 3 U2 15 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 1070-664X J9 PHYS PLASMAS JI Phys. Plasmas PD MAY PY 1998 VL 5 IS 5 SI SI BP 1615 EP 1623 DI 10.1063/1.872820 PN 2 PG 9 WC Physics, Fluids & Plasmas SC Physics GA ZN238 UT WOS:000073623700006 ER PT J AU Karney, CFF AF Karney, CFF TI Modern computational techniques in plasma physics SO PHYSICS OF PLASMAS LA English DT Article; Proceedings Paper CT 39th Annual Meeting of the Division-of-Plasma-Physics of the American-Physical-Society CY NOV 17-21, 1997 CL PITTSBURGH, PENNSYLVANIA SP Amer Phys Soc, Div Plasma Phys AB This paper offers practical suggestions for how to make the best use of computers to model plasma behavior. This includes advice for ensuring the correctness of a computer code, how to manage a large code project, and how to take advantage of parallel computers. (C) 1998 American Institute of Physics. C1 Princeton Univ, Plasma Phys Lab, Princeton, NJ 08543 USA. RP Karney, CFF (reprint author), Princeton Univ, Plasma Phys Lab, POB 451, Princeton, NJ 08543 USA. EM Karney@Princeton.EDU RI Karney, Charles/C-1371-2013 OI Karney, Charles/0000-0002-5006-5836 NR 8 TC 0 Z9 0 U1 1 U2 1 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 1070-664X J9 PHYS PLASMAS JI Phys. Plasmas PD MAY PY 1998 VL 5 IS 5 SI SI BP 1632 EP 1635 DI 10.1063/1.872831 PN 2 PG 4 WC Physics, Fluids & Plasmas SC Physics GA ZN238 UT WOS:000073623700008 ER PT J AU Nazikian, R Fu, GY Chang, Z Batha, SH Berk, H Budny, RV Chen, Y Cheng, CZ Darrow, DS Gorelenkov, NN Levinton, FM Medley, S Petrov, MP Redi, M Ruskov, E Spong, DA White, RB Zweben, SJ AF Nazikian, R Fu, GY Chang, Z Batha, SH Berk, H Budny, RV Chen, Y Cheng, CZ Darrow, DS Gorelenkov, NN Levinton, FM Medley, S Petrov, MP Redi, M Ruskov, E Spong, DA White, RB Zweben, SJ TI Toroidal Alfven eigenmodes in TFTR deuterium-tritium plasmas SO PHYSICS OF PLASMAS LA English DT Article; Proceedings Paper CT 39th Annual Meeting of the Division-of-Plasma-Physics of the American-Physical-Society CY NOV 17-21, 1997 CL PITTSBURGH, PENNSYLVANIA SP Amer Phys Soc, Div Plasma Phys ID FUSION ALPHA-PARTICLES; TOKAMAK; SIMULATIONS; EXCITATION; FLUCTUATIONS; WAVES; MODES; CORE AB Purely alpha-particle-driven toroidal Alfven eigenmodes (TAEs) with toroidal mode numbers n = 1-6 have been observed in deuterium-tritium (D-T) plasmas on the tokamak fusion test reactor [D. J. Grove and D. M. Meade, Nucl. Fusion 25, 1167 (1985)]. The appearance of mode activity following termination of neutral beam injection in plasmas with q(0)>1 is generally consistent with theoretical predictions of TAE stability [G. Y. Fu et al. Phys. Plasmas 3, 4036 (1996)]. Internal reflectometer measurements of TAE activity is compared with theoretical calculations of the radial mode structure. Core localization of the modes to the region of reduced central magnetic shear is confirmed, however the mode structure can deviate significantly from theoretical estimates. The peak measured TAE amplitude of delta n/n similar to 10(-4) at r/a similar to 0.3-0.4 corresponds to delta B/B similar to 10(-5), while delta B/B similar to 10(-8) is measured at the plasma edge. Enhanced alpha particle lass associated with TAE activity has not been observed. (C) 1998 American Institute of Physics. C1 Princeton Plasma Phys Lab, Princeton, NJ 08543 USA. RP Nazikian, R (reprint author), Princeton Plasma Phys Lab, POB 451, Princeton, NJ 08543 USA. RI Spong, Donald/C-6887-2012; White, Roscoe/D-1773-2013; Cheng, Chio/K-1005-2014 OI Spong, Donald/0000-0003-2370-1873; White, Roscoe/0000-0002-4239-2685; NR 28 TC 28 Z9 28 U1 0 U2 3 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 1070-664X J9 PHYS PLASMAS JI Phys. Plasmas PD MAY PY 1998 VL 5 IS 5 SI SI BP 1703 EP 1711 DI 10.1063/1.872818 PN 2 PG 9 WC Physics, Fluids & Plasmas SC Physics GA ZN238 UT WOS:000073623700017 ER PT J AU Wilson, JR Bell, RE Bernabei, S Hill, K Hosea, JC LeBlanc, B Majeski, R Nazikian, R Ono, M Phillips, CK Schilling, G von Goeler, S Bush, CE Hanson, GR AF Wilson, JR Bell, RE Bernabei, S Hill, K Hosea, JC LeBlanc, B Majeski, R Nazikian, R Ono, M Phillips, CK Schilling, G von Goeler, S Bush, CE Hanson, GR TI Ion cyclotron range of frequencies heating and flow generation in deuterium-tritium plasmas SO PHYSICS OF PLASMAS LA English DT Article; Proceedings Paper CT 39th Annual Meeting of the Division-of-Plasma-Physics of the American-Physical-Society CY NOV 17-21, 1997 CL PITTSBURGH, PA SP Amer Phys Soc, Div Plasma Phys ID BERNSTEIN WAVE ANTENNA; EDGE TURBULENCE; DIII-D; PBX-M; TRANSPORT; TOKAMAK; PROFILE; POWER; TFTR AB Recent radio-frequency heating experiments on the Tokamak Fusion Test Reactor (TFTR) [Hawryluk ct al., Plasma Phys. Controlled Fusion 33, 1509 (1991)] have focused on developing tools for both pressure and current profile control in deuterium-tritium (DT) plasmas. A new antenna was added to investigate pressure profile control utilizing direct ion Bernstein wave (IBW) heating. This was the first time direct IBW heating was explored on TFTR. Plasma heating and driven poloidal hows are observed. Previously heating and current drive via mode-converted IBW waves had been demonstrated in non-DT plasmas but efforts in DT plasmas had been unsuccessful. This lack of success had been ascribed to the presence of a small Li-7 minority ion population. In the most recent experiments Li-6 was used exclusively for machine conditioning and mode-conversion heating consistent with theory is now observed in DT plasmas. (C) 1998 American Institute of Physics. C1 Princeton Plasma Phys Lab, Princeton, NJ 08543 USA. Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Princeton Plasma Phys Lab, POB 451, Princeton, NJ 08543 USA. NR 19 TC 35 Z9 35 U1 0 U2 3 PU AMER INST PHYSICS PI MELVILLE PA 1305 WALT WHITMAN RD, STE 300, MELVILLE, NY 11747-4501 USA SN 1070-664X EI 1089-7674 J9 PHYS PLASMAS JI Phys. Plasmas PD MAY PY 1998 VL 5 IS 5 SI SI BP 1721 EP 1726 DI 10.1063/1.872840 PN 2 PG 6 WC Physics, Fluids & Plasmas SC Physics GA ZN238 UT WOS:000073623700019 ER PT J AU Spong, DA Hirshman, SP Whitson, JC Batchelor, DB Carreras, BA Lynch, VE Rome, JA AF Spong, DA Hirshman, SP Whitson, JC Batchelor, DB Carreras, BA Lynch, VE Rome, JA TI J* optimization of small aspect ratio stellarator/tokamak hybrid devices SO PHYSICS OF PLASMAS LA English DT Article; Proceedings Paper CT 39th Annual Meeting of the Division-of-Plasma-Physics of the American-Physical-Society CY NOV 17-21, 1997 CL PITTSBURGH, PENNSYLVANIA SP Amer Phys Soc, Div Plasma Phys ID EQUILIBRIA; TRANSPORT; FIELDS AB A new class of low aspect ratio toroidal hybrid stellarators is found using a more general plasma confinement optimization criterion than quasisymmetrization. The plasma current profile and shape of the outer magnetic flux surface are used as control variables to achieve near constancy of the longitudinal invariant J* on internal flux surfaces (quasiomnigeneity), in addition to a number of other desirable physics target properties. A range of compact (small aspect ratio A), low plasma current devices have been found with significantly improved confinement, both for thermal as well as energetic (collisionless) particle components. With reasonable increases in magnetic field and geometric size, such devices can also be scaled to confine 3.5 MeV alpha particle orbits. C1 Oak Ridge Natl Lab, Oak Ridge, TN 37830 USA. RP Spong, DA (reprint author), Oak Ridge Natl Lab, POB 2009, Oak Ridge, TN 37830 USA. RI Spong, Donald/C-6887-2012; Lynch, Vickie/J-4647-2012 OI Spong, Donald/0000-0003-2370-1873; Lynch, Vickie/0000-0002-5836-7636 NR 22 TC 18 Z9 18 U1 0 U2 1 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 1070-664X J9 PHYS PLASMAS JI Phys. Plasmas PD MAY PY 1998 VL 5 IS 5 SI SI BP 1752 EP 1758 DI 10.1063/1.872844 PN 2 PG 7 WC Physics, Fluids & Plasmas SC Physics GA ZN238 UT WOS:000073623700023 ER PT J AU Gates, DA Akers, R Appel, L Carolan, PG Conway, N Dowling, J Gryaznevich, M Hender, T Kwon, OJ Martin, R Nightingale, M Price, M Roach, C Sykes, A Tournianski, MR Walsh, M Warrick, CD AF Gates, DA Akers, R Appel, L Carolan, PG Conway, N Dowling, J Gryaznevich, M Hender, T Kwon, OJ Martin, R Nightingale, M Price, M Roach, C Sykes, A Tournianski, MR Walsh, M Warrick, CD CA START Teams NBI Teams TI High-performance discharges in the Small Tight Aspect Ratio Tokamak (START) SO PHYSICS OF PLASMAS LA English DT Article; Proceedings Paper CT 39th Annual Meeting of the Division-of-Plasma-Physics of the American-Physical-Society CY NOV 17-21, 1997 CL PITTSBURGH, PENNSYLVANIA SP Amer Phys Soc, Div Plasma Phys ID STABILITY; PLASMAS AB The Small Tight Aspect Ratio Tokamak (START) [A. Sykes et al., Nucl. Fusion 32, 769 (1994)] spherical tokamak has recently achieved the record value of toroidal beta similar to-30% in a tokamak-like configuration. The improvements that have made these results possible are presented along with a description of the global equilibrium parameters of the discharges. The ideal magnetohydrodynamic (MHD) stability of these discharges is analyzed, and they are found to be in close proximity to both the ballooning limit and the external current driven kink limit, but they are found to be far from the pressure driven external kink Limit. Disruptivity for a range of shots is not correlated with the normalized beta limit, but does correlate well with the empirical high-l(i) disruption limit. The transport properties of these high-beta-equilibria are analyzed and compared to conventional tokamak scaling laws and transport models. The global transport is at least as good as that predicted by the ITER97-ELMy (edge-localized) scaling law. The local ion transport is in good agreement with that predicted by neoclassical models. The electron transport is anomalous, showing rough agreement with the Lackner-Gottardi transport model. (C) 1998 American Institute of Physics. C1 UKAEA Euratom Fus Assoc, Culham Lab, Abingdon OX14 3DB, Oxon, England. RP Gates, DA (reprint author), Princeton Plasma Phys Lab, POB 451, Princeton, NJ 08543 USA. RI Roach, Colin/C-4839-2011 NR 17 TC 34 Z9 34 U1 0 U2 5 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 1070-664X J9 PHYS PLASMAS JI Phys. Plasmas PD MAY PY 1998 VL 5 IS 5 SI SI BP 1775 EP 1783 DI 10.1063/1.872819 PN 2 PG 9 WC Physics, Fluids & Plasmas SC Physics GA ZN238 UT WOS:000073623700026 ER PT J AU Rewoldt, G Beer, MA Chance, MS Hahm, TS Lin, Z Tang, WM AF Rewoldt, G Beer, MA Chance, MS Hahm, TS Lin, Z Tang, WM TI Sheared rotation effects on kinetic stability in enhanced confinement tokamak plasmas, and nonlinear dynamics of fluctuations and flows in axisymmetric plasmas SO PHYSICS OF PLASMAS LA English DT Article; Proceedings Paper CT 39th Annual Meeting of the Division-of-Plasma-Physics of the American-Physical-Society CY NOV 17-21, 1997 CL PITTSBURGH, PENNSYLVANIA SP Amer Phys Soc, Div Plasma Phys ID GRADIENT-DRIVEN TURBULENCE; REVERSED MAGNETIC SHEAR; FLUID MODEL TURBULENCE; TOROIDAL PLASMA; TRANSPORT; TFTR; SIMULATIONS; INSTABILITIES; GENERATION; GEOMETRY AB Sheared rotation dynamics are widely believed to have significant influence on experimentally-observed confinement transitions in advanced operating modes in major tokamak experiments, such as the Tokamak Fusion Test Reactor (TFTR) [D. J. Grove and D. M. Meade, Nucl. Fusion 25, 1167 (1985)], with reversed magnetic shear regions in the plasma interior. The high-n toroidal drift modes destabilized by the combined effects of ion temperature gradients and trapped particles in toroidal geometry can be strongly affected by radially-sheared toroidal and poloidal plasma rotation. In previous work with the FULL Linear microinstability code, a simplified rotation model including only toroidal rotation was employed, and results were obtained. Here, a more complete rotation model, which includes contributions from toroidal and poloidal rotation and the ion pressure gradient to the total radial electric field, is used for a proper self-consistent treatment of this key problem. Relevant advanced operating mode cases for TFTR are presented. In addition, the complementary problem of the dynamics of fluctuation-driven ExB flow is investigated by an integrated program of gyrokinetic simulation in annulus geometry and gyrofluid simulation in flux tube geometry. (C) 1998 American Institute of Physics. C1 Princeton Univ, Plasma Phys Lab, Princeton, NJ 08543 USA. RP Rewoldt, G (reprint author), Princeton Univ, Plasma Phys Lab, Princeton, NJ 08543 USA. NR 48 TC 25 Z9 25 U1 0 U2 1 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 1070-664X J9 PHYS PLASMAS JI Phys. Plasmas PD MAY PY 1998 VL 5 IS 5 SI SI BP 1815 EP 1821 DI 10.1063/1.872851 PN 2 PG 7 WC Physics, Fluids & Plasmas SC Physics GA ZN238 UT WOS:000073623700031 ER PT J AU Mattor, N AF Mattor, N TI Collisionless fluid closure theory and the phase velocity transform SO PHYSICS OF PLASMAS LA English DT Article; Proceedings Paper CT 39th Annual Meeting of the Division-of-Plasma-Physics of the American-Physical-Society CY NOV 17-21, 1997 CL PITTSBURGH, PENNSYLVANIA SP Amer Phys Soc, Div Plasma Phys ID MODELS AB Fluid equations are derived that describe wave-particle resonances, which usually require kinetic theory. The phase velocity transform is introduced, which decomposes a function of space and time into a sum over components with constant phase velocity. This leads to a new technique to solve partial differential equations, similar but not identical to the Radon transform, and produces recursive solutions. This technique is applied to the collisionless drift kinetic equation, to give closure of the fluid moment hierarchy. The result is a new term in the highest moment equation that retains many nonlinear wave-particle effects not before described by fluid equations. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Mattor, N (reprint author), Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. NR 23 TC 9 Z9 9 U1 0 U2 1 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 1070-664X J9 PHYS PLASMAS JI Phys. Plasmas PD MAY PY 1998 VL 5 IS 5 SI SI BP 1822 EP 1831 DI 10.1063/1.872852 PN 2 PG 10 WC Physics, Fluids & Plasmas SC Physics GA ZN238 UT WOS:000073623700032 ER PT J AU Efthimion, PC von Goeler, S Houlberg, WA Synakowski, EJ Zarnstorff, MC Batha, SH Bell, RE Bitter, M Bush, CE Levinton, FM Mazzucato, E McCune, D Mueller, D Park, H Ramsey, AT Roquemore, AL Taylor, G AF Efthimion, PC von Goeler, S Houlberg, WA Synakowski, EJ Zarnstorff, MC Batha, SH Bell, RE Bitter, M Bush, CE Levinton, FM Mazzucato, E McCune, D Mueller, D Park, H Ramsey, AT Roquemore, AL Taylor, G TI Observation of particle transport barriers in reverse shear plasmas on the Tokamak Fusion Test Reactor SO PHYSICS OF PLASMAS LA English DT Article; Proceedings Paper CT 39th Annual Meeting of the Division-of-Plasma-Physics of the American-Physical-Society CY NOV 17-21, 1997 CL PITTSBURGH, PENNSYLVANIA SP Amer Phys Soc, Div Plasma Phys ID MAGNETIC SHEAR; TFTR TOKAMAK; TURBULENCE; DISCHARGES; HELIUM; CONFINEMENT; MODES; IRON AB Perturbative experiments on the Tokamak Fusion Test Reactor [Phys. Plasmas 4, 1736 (1997)] (TFTR) have investigated transport in reverse shear plasmas. On TFTR, reverse magnetic shear plasmas bifurcate into two states with different transport properties: reverse shear (RS) and enhanced reverse shear (ERS) with improved core confinement. Measurements of the 14 MeV t(d,n)alpha neutrons and charge-exchange recombination radiation spectra are used to infer the trace tritium and helium profiles, respectively. The profile evolution indicate the formation of core particle transport barriers in ERS plasmas. The transport barrier is manifested by an order-of-magnitude reduction in the particle diffusivity (D-T,D-He) and a smaller reduction in the pinch within the reverse shear region. The low diffusivities are consistent with neoclassical predictions. Furthermore, D-T and D(He)approximate to chi(eff), the effective thermal diffusivity. Although the measured coefficients imply no helium ash accumulation, the situation is uncertain in a reactor due to unknown chi(eff) scaling. C1 Princeton Univ, Princeton Plasma Phys Lab, Princeton, NJ 08543 USA. Oak Ridge Natl Lab, Oak Ridge, TN 37830 USA. Fus Phys & Technol, Torrance, CA 90503 USA. RP Efthimion, PC (reprint author), Princeton Univ, Princeton Plasma Phys Lab, Princeton, NJ 08543 USA. NR 32 TC 21 Z9 21 U1 1 U2 4 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 1070-664X J9 PHYS PLASMAS JI Phys. Plasmas PD MAY PY 1998 VL 5 IS 5 SI SI BP 1832 EP 1838 DI 10.1063/1.872853 PN 2 PG 7 WC Physics, Fluids & Plasmas SC Physics GA ZN238 UT WOS:000073623700033 ER PT J AU Navratil, GA Cates, C Mauel, ME Maurer, D Nadle, D Taylor, E Xiao, Q Reass, WA Wurden, GA AF Navratil, GA Cates, C Mauel, ME Maurer, D Nadle, D Taylor, E Xiao, Q Reass, WA Wurden, GA TI Active control of 2/1 magnetic islands in a tokamak SO PHYSICS OF PLASMAS LA English DT Article; Proceedings Paper CT 39th Annual Meeting of the Division-of-Plasma-Physics of the American-Physical-Society CY NOV 17-21, 1997 CL PITTSBURGH, PENNSYLVANIA SP Amer Phys Soc, Div Plasma Phys ID FEEDBACK-CONTROL; WALL STABILIZATION; HIGH-BETA; DIII-D; MODES; PERTURBATIONS; PERFORMANCE; PLASMAS; FIELD; JET AB Closed and open loop control techniques were applied to growing m/n=2/1 rotating islands in wall-stabilized plasmas in the High Beta Tokamak-Extended Pulse (HBT-EP) [J. Fusion Energy 12, 303 (1993)]. HBT-EP combines an adjustable, segmented conducting wall (which slows the growth or stabilizes ideal external kinks) with a number of small (6 degrees wide toroidally) driven saddle coils located between the gaps of the conducting wall. Two-phase driven magnetic island rotation control from 5 to 15 kHz has been demonstrated powered by two 10 MW linear amplifiers. The phase instability has been observed and is well modeled by the single-helicity predictions of nonlinear Rutherford island dynamics for 2/1 tearing modes including important effects of ion inertia and finite Larmor radius, which appear as a damping term in the model equations. The closed loop response of active feedback control of the 2/1 mode at moderate gain was observed to be in good agreement with the theory. Suppression of the 2/1 island growth has been demonstrated using an asynchronous frequency modulation drive which maintains the inertial flow damping of the island by application of rotating control fields with frequencies alternating above and below the natural mode frequency. This frequency modulation control technique was also able to prevent disruptions normally observed to follow giant sawtooth crashes in the plasma core. (C) I998 American Institute of Physics. C1 Columbia Univ, Dept Appl Phys, New York, NY 10027 USA. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Navratil, GA (reprint author), Columbia Univ, Dept Appl Phys, New York, NY 10027 USA. RI Wurden, Glen/A-1921-2017; OI Wurden, Glen/0000-0003-2991-1484; Mauel, Michael/0000-0003-2490-7478 NR 22 TC 42 Z9 44 U1 0 U2 2 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 1070-664X J9 PHYS PLASMAS JI Phys. Plasmas PD MAY PY 1998 VL 5 IS 5 SI SI BP 1855 EP 1863 DI 10.1063/1.872856 PN 2 PG 9 WC Physics, Fluids & Plasmas SC Physics GA ZN238 UT WOS:000073623700036 ER PT J AU Collins, GW Celliers, P Da Silva, LB Cauble, R Gold, D Foord, M Budil, KS Stewart, R Holmes, NC Ross, M Hammel, BA Kilkenny, JD Wallace, RJ Ng, A AF Collins, GW Celliers, P Da Silva, LB Cauble, R Gold, D Foord, M Budil, KS Stewart, R Holmes, NC Ross, M Hammel, BA Kilkenny, JD Wallace, RJ Ng, A TI Equation of state measurements of hydrogen isotopes on Nova SO PHYSICS OF PLASMAS LA English DT Article; Proceedings Paper CT 39th Annual Meeting of the Division-of-Plasma-Physics of the American-Physical-Society CY NOV 17-21, 1997 CL PITTSBURGH, PENNSYLVANIA SP Amer Phys Soc, Div Plasma Phys ID NATIONAL-IGNITION-FACILITY; MOLECULAR-HYDROGEN; TEMPERATURE-MEASUREMENTS; DENSE HYDROGEN; SHOCK; DISSOCIATION; DEUTERIUM; PRESSURES; ALUMINUM; DESIGN AB The Nova laser [E. M. Campbell, Laser Part. Beams 9, 209 (1991)] was used to shock-compress liquid deuterium and obtain new principal Hugoniot measurements of density and pressure between 0.3 and 2.1 Mbar. In this pressure-density region, deuterium is predicted to transform from a molecular insulating fluid to an atomic conducting fluid. Nova data show a rapid increase in density from 0.6 g/cc at 0.3 Mbar, to 1 g/cc at 0.6 Mbar, suggestive of such a transition. The observed sixfold compression near 1 Mbar is larger than predicted by many widely used equation of slate models. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. Univ British Columbia, Vancouver, BC V5Z 1M9, Canada. RP Collins, GW (reprint author), Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. NR 36 TC 42 Z9 48 U1 1 U2 2 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 1070-664X J9 PHYS PLASMAS JI Phys. Plasmas PD MAY PY 1998 VL 5 IS 5 SI SI BP 1864 EP 1869 DI 10.1063/1.872857 PN 2 PG 6 WC Physics, Fluids & Plasmas SC Physics GA ZN238 UT WOS:000073623700037 ER PT J AU Bradley, DK Delettrez, JA Epstein, R Town, RPJ Verdon, CP Yaakobi, B Regan, S Marshall, FJ Boehly, TR Knauer, JP Meyerhofer, DD Smalyuk, VA Seka, W Haynes, DA Gunderson, M Junkel, G Hooper, CF Bell, PM Ognibene, TJ Lerche, RA AF Bradley, DK Delettrez, JA Epstein, R Town, RPJ Verdon, CP Yaakobi, B Regan, S Marshall, FJ Boehly, TR Knauer, JP Meyerhofer, DD Smalyuk, VA Seka, W Haynes, DA Gunderson, M Junkel, G Hooper, CF Bell, PM Ognibene, TJ Lerche, RA TI Measurements of core and pusher conditions in surrogate capsule implosions on the OMEGA laser system SO PHYSICS OF PLASMAS LA English DT Article; Proceedings Paper CT 39th Annual Meeting of the Division-of-Plasma-Physics of the American-Physical-Society CY NOV 17-21, 1997 CL PITTSBURGH, PENNSYLVANIA SP Amer Phys Soc, Div Plasma Phys ID INERTIAL-CONFINEMENT-FUSION; RAYLEIGH-TAYLOR INSTABILITY; LINE-PROFILES; INDIRECTLY DRIVEN; GROWTH; PLASMAS; SPECTROSCOPY; SATURATION; UNIFORMITY; OPACITY AB Experiments have been carried out on the 60-beam, 30 kJ OMEGA laser system [T. R. Boehly er al., Opt. Commun. 133, 495 (1997)] as part of an integrated program to diagnose all phases of direct-drive capsule implosions. Laser-imprint levels and Rayleigh-Taylor growth rates associated with the spherical implosions have been inferred from planar-foil radiography experiments. In spherical targets, measurements of the combined effects of imprint and unstable growth at the ablation surface have been carried out using the burnthrough technique [J. Delettrez et al., Phys. Plasmas 1, 2342 (1994)]. Target behavior during the deceleration phase has been investigated using a series of surrogate cryogenic capsules in which the main fuel layer is represented by a Ti-doped CH shell and the hot spot is represented by an Ar-doped deuterium fill gas. (C) 1998 American Institute of Physics. C1 Univ Rochester, Laser Energet Lab, Rochester, NY 14623 USA. Univ Florida, Dept Phys, Gainesville, FL 32611 USA. Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Bradley, DK (reprint author), Univ Rochester, Laser Energet Lab, 250 E River Rd, Rochester, NY 14623 USA. NR 42 TC 34 Z9 34 U1 1 U2 6 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 1070-664X J9 PHYS PLASMAS JI Phys. Plasmas PD MAY PY 1998 VL 5 IS 5 SI SI BP 1870 EP 1879 DI 10.1063/1.872858 PN 2 PG 10 WC Physics, Fluids & Plasmas SC Physics GA ZN238 UT WOS:000073623700038 ER PT J AU Hinkel, DE Williams, EA Berger, RL Powers, LV Langdon, AB Still, CH AF Hinkel, DE Williams, EA Berger, RL Powers, LV Langdon, AB Still, CH TI Propagation of realistic beams in underdense plasma SO PHYSICS OF PLASMAS LA English DT Article; Proceedings Paper CT 39th Annual Meeting of the Division-of-Plasma-Physics of the American-Physical-Society CY NOV 17-21, 1997 CL PITTSBURGH, PENNSYLVANIA SP Amer Phys Soc, Div Plasma Phys ID LASER-BEAM; ELECTROMAGNETIC-WAVES; LIGHT; FILAMENTATION; SCATTERING; DEFLECTION; ABSORPTION; FREQUENCY; NOVA AB The effect of beam structure on propagation through underdense plasma is examined in two different examples. First, it is shown that the distribution of intensities within a laser beam affects how the beam deflects in the presence of transverse plasma how. A detailed analysis of beam deflection shows that the rate scales linearly with intensity and plasma density, and inversely with plasma temperature. When the plasma flow is subsonic, the deflection rate is proportional to the ion damping decrement, and scales as M/(1-M-2)(3/2): where M is the transverse flow Mach number. When the plasma flow is supersonic, the deflection rate scales as 1/[M(M-2-1))(1/2)]. Next, the effect of beam structure on channel formation by very intense laser beams is studied. A diffraction-limited beam with similar to 3 TW of input power forms a channel through 400 mu m of plasma, whereas when this beam is phase aberrated, channel formation does not occur. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Hinkel, DE (reprint author), Univ Calif Lawrence Livermore Natl Lab, POB 808, Livermore, CA 94550 USA. NR 28 TC 15 Z9 15 U1 1 U2 1 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 1070-664X J9 PHYS PLASMAS JI Phys. Plasmas PD MAY PY 1998 VL 5 IS 5 SI SI BP 1887 EP 1894 DI 10.1063/1.872859 PN 2 PG 8 WC Physics, Fluids & Plasmas SC Physics GA ZN238 UT WOS:000073623700040 ER PT J AU Tabak, M Callahan-Miller, D AF Tabak, M Callahan-Miller, D TI Design of a distributed radiator target for inertial fusion driven from two sides with heavy ion beams SO PHYSICS OF PLASMAS LA English DT Article; Proceedings Paper CT 39th Annual Meeting of the Division-of-Plasma-Physics of the American-Physical-Society CY NOV 17-21, 1997 CL PITTSBURGH, PENNSYLVANIA SP Amer Phys Soc, Div Plasma Phys ID NATIONAL-IGNITION-FACILITY; PHYSICS; GAIN AB The status of a distributed radiator heavy-ion target design is described. In integrated calculations this target ignited and produced 390-430 MJ of yield when driven with 5.8-6.5 MJ of 3-4 GeV Pb ions. The target has cylindrical symmetry with disk endplates. The ions uniformly illuminate these endplates in a 5 mm radius spot. Considerations which led to this design are discussed together with some previously unused design features: low-density hohlraum walls in approximate pressure balance with internal low-Z fill materials, radiation symmetry determined by the position of the radiator materials and particle ranges, and early time pressure symmetry possibly influenced by radiation shims. How this target scales to lower input energy or to lower beam power is discussed. Variant designs with more realistic beam focusing strategies are also discussed. Tradeoffs required for targets which accept higher particle energies are described. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Tabak, M (reprint author), Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. NR 17 TC 36 Z9 36 U1 1 U2 3 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 1070-664X J9 PHYS PLASMAS JI Phys. Plasmas PD MAY PY 1998 VL 5 IS 5 SI SI BP 1895 EP 1900 DI 10.1063/1.872860 PN 2 PG 6 WC Physics, Fluids & Plasmas SC Physics GA ZN238 UT WOS:000073623700041 ER PT J AU Bodner, SE Colombant, DG Gardner, JH Lehmberg, RH Obenschain, SP Phillips, L Schmitt, AJ Sethian, JD McCrory, RL Seka, W Verdon, CP Knauer, JP Afeyan, BB Powell, HT AF Bodner, SE Colombant, DG Gardner, JH Lehmberg, RH Obenschain, SP Phillips, L Schmitt, AJ Sethian, JD McCrory, RL Seka, W Verdon, CP Knauer, JP Afeyan, BB Powell, HT TI Direct-drive laser fusion: Status and prospects SO PHYSICS OF PLASMAS LA English DT Article; Proceedings Paper CT 39th Annual Meeting of the Division-of-Plasma-Physics of the American-Physical-Society CY NOV 17-21, 1997 CL PITTSBURGH, PENNSYLVANIA SP Amer Phys Soc, Div Plasma Phys ID RAYLEIGH-TAYLOR INSTABILITY; INDUCED SPATIAL INCOHERENCE; STEEP TEMPERATURE-GRADIENTS; CONSISTENT STABILITY ANALYSIS; INERTIAL CONFINEMENT FUSION; STIMULATED RAMAN-SCATTERING; SCALE-LENGTH PLASMAS; HYDRODYNAMIC INSTABILITIES; INHOMOGENEOUS PLASMAS; UNIFORM ILLUMINATION AB Techniques have been developed to improve the uniformity of the laser focal profile, to reduce the ablative Rayleigh-Taylor instability, and to suppress the various laser-plasma instabilities. There are now three direct-drive ignition target designs that utilize these techniques. An evaluation of these designs is still ongoing. Some of them may achieve the gains above 100 that are necessary for a fusion reactor. Two laser systems have been proposed that may meet all of the requirements for a fusion reactor. (C) 1998 American Institute of Physics. C1 USN, Res Lab, Div Plasma Phys, Washington, DC 20375 USA. Univ Rochester, Laser Energet Lab, Rochester, NY 14623 USA. Polymath Associates, Livermore, CA 94550 USA. Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. USN, Res Lab, Computat Phys & Fluid Dynam Lab, Washington, DC 20375 USA. RP Bodner, SE (reprint author), USN, Res Lab, Div Plasma Phys, Washington, DC 20375 USA. NR 111 TC 249 Z9 257 U1 8 U2 31 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 1070-664X J9 PHYS PLASMAS JI Phys. Plasmas PD MAY PY 1998 VL 5 IS 5 SI SI BP 1901 EP 1918 DI 10.1063/1.872861 PN 2 PG 18 WC Physics, Fluids & Plasmas SC Physics GA ZN238 UT WOS:000073623700042 ER PT J AU Kauffman, RL Powers, LV Dixit, SN Glendinning, SG Glenzer, SH Kirkwood, RK Landon, OL MacGowan, BJ Moody, JD Orzechowski, TJ Pennington, DM Stone, GF Suter, LJ Turner, RE Weiland, TL Richard, AL Blain, MA AF Kauffman, RL Powers, LV Dixit, SN Glendinning, SG Glenzer, SH Kirkwood, RK Landon, OL MacGowan, BJ Moody, JD Orzechowski, TJ Pennington, DM Stone, GF Suter, LJ Turner, RE Weiland, TL Richard, AL Blain, MA TI Improved gas-filled hohlraum performance on Nova with beam smoothing SO PHYSICS OF PLASMAS LA English DT Article; Proceedings Paper CT 39th Annual Meeting of the Division-of-Plasma-Physics of the American-Physical-Society CY NOV 17-21, 1997 CL PITTSBURGH, PENNSYLVANIA SP Amer Phys Soc, Div Plasma Phys ID INERTIAL CONFINEMENT FUSION; STIMULATED RAMAN-SCATTERING; NATIONAL-IGNITION-FACILITY; LASER; RADIATION; SYMMETRY; PLASMAS; DRIVE; DEFLECTION; DESIGN AB Gas-filled hohlraums are presently the base line ignition target design for the National Ignition Facility. Initial Nova [E. M. Campbell et al. Rev. Sci. Instrum. 57, 2101 (1986).] experiments on gas-filled hohlraums showed that radiation temperature was reduced due to stimulated Brillouin and stimulated Raman scattering losses and that implosion symmetry had shifted compared with vacuum hohlraums and calculations. Subsequent single beam experiments imaging thermal x-ray emission showed the shift is due to laser-plasma heating dynamics and filamentation in a flowing plasma. Experiments using a single beam have shown that scattering losses and effects of filamentation are reduced when the beam is spatially smoothed with a random phase plate or kinoform phase plate. Scattering is further reduced to less than 5% of the incident laser energy when temporal smoothing is added. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. CEA, Ctr Etud Limeil Valenton, F-94190 Villeneuve St Georges, France. RP Kauffman, RL (reprint author), Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. NR 33 TC 30 Z9 31 U1 0 U2 6 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 1070-664X J9 PHYS PLASMAS JI Phys. Plasmas PD MAY PY 1998 VL 5 IS 5 SI SI BP 1927 EP 1934 DI 10.1063/1.872822 PN 2 PG 8 WC Physics, Fluids & Plasmas SC Physics GA ZN238 UT WOS:000073623700044 ER PT J AU Wilson, DC Bradley, PA Hoffman, NM Swenson, FJ Smitherman, DP Chrien, RE Margevicius, RW Thoma, DJ Foreman, LR Hoffer, JK Goldman, SR Caldwell, SE Dittrich, TR Haan, SW Marinak, MM Pollaine, SM Sanchez, JJ AF Wilson, DC Bradley, PA Hoffman, NM Swenson, FJ Smitherman, DP Chrien, RE Margevicius, RW Thoma, DJ Foreman, LR Hoffer, JK Goldman, SR Caldwell, SE Dittrich, TR Haan, SW Marinak, MM Pollaine, SM Sanchez, JJ TI The development and advantages of beryllium capsules for the National Ignition Facility SO PHYSICS OF PLASMAS LA English DT Article; Proceedings Paper CT 39th Annual Meeting of the Division-of-Plasma-Physics of the American-Physical-Society CY NOV 17-21, 1997 CL PITTSBURGH, PA SP Amer Phys Soc, Div Plasma Phys ID DESIGN AB Capsules with beryllium ablators have long been considered as alternatives to plastic for the National Ignition Facility laser [J. A. Paisner et al., Laser Focus World 30, 75 (1994)]; now the superior performance of beryllium is becoming well substantiated. Beryllium capsules have the advantages of high density, low opacity, high tensile strength, and high thermal conductivity. Three-dimensional (3-D) calculations with the HYDRA code [NTIS Document No. DE-96004569 (M. M. Marinak et al. in UCRL-LR-105821-95-3)] confirm two-dimensional (2-D) LASNEX [G. B. Zimmerman and W. L. Kruer, Comments Plasmas Phys. Controlled Thermonucl. Fusion 2, 51 (1975)] results that particular beryllium capsule designs are several times less sensitive than the CH point design to instability growth from deuterium-tritium (DT) ice roughness. These capsule designs contain more ablator mass and leave some beryllium unablated at ignition. By adjusting the level of copper dopant, the unablated mass can increase or decrease, with a corresponding decrease or increase in sensitivity to perturbations. A plastic capsule with the same ablator mass as the beryllium and leaving the same unablated mass also shows this reduced perturbation sensitivity. Beryllium's low opacity permits the creation of 250 eV capsule designs. Its high tensile strength allows it to contain DT fuel at room temperature. Its high thermal conductivity simplifies cryogenic fielding. (C) 1998 American Institute of Physics. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. RP Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. EM dcw@lanl.gov NR 24 TC 112 Z9 115 U1 5 U2 14 PU AMER INST PHYSICS PI MELVILLE PA 1305 WALT WHITMAN RD, STE 300, MELVILLE, NY 11747-4501 USA SN 1070-664X EI 1089-7674 J9 PHYS PLASMAS JI Phys. Plasmas PD MAY PY 1998 VL 5 IS 5 SI SI BP 1953 EP 1959 DI 10.1063/1.872865 PN 2 PG 7 WC Physics, Fluids & Plasmas SC Physics GA ZN238 UT WOS:000073623700047 ER PT J AU Murphy, TJ Wallace, JM Delamater, ND Barnes, CW Gobby, P Hauer, AA Lindman, EL Magelssen, G Moore, JB Oertel, JA Watt, R Landen, OL Amendt, P Cable, M Decker, C Hammel, BA Koch, JA Suter, LJ Turner, RE Wallace, RJ Marshall, FJ Bradley, D Craxton, RS Keek, R Knauer, JP Kremens, R Schnittman, JD AF Murphy, TJ Wallace, JM Delamater, ND Barnes, CW Gobby, P Hauer, AA Lindman, EL Magelssen, G Moore, JB Oertel, JA Watt, R Landen, OL Amendt, P Cable, M Decker, C Hammel, BA Koch, JA Suter, LJ Turner, RE Wallace, RJ Marshall, FJ Bradley, D Craxton, RS Keek, R Knauer, JP Kremens, R Schnittman, JD TI Indirect drive experiments utilizing multiple beam cones in cylindrical hohlraums on OMEGA SO PHYSICS OF PLASMAS LA English DT Article; Proceedings Paper CT 39th Annual Meeting of the Division-of-Plasma-Physics of the American-Physical-Society CY NOV 17-21, 1997 CL PITTSBURGH, PENNSYLVANIA SP Amer Phys Soc, Div Plasma Phys ID INERTIAL CONFINEMENT FUSION; NOVA; IGNITION; FACILITY; TARGETS AB Current plans for time-dependent control of flux asymmetry in the National Ignition Facility [J. A. Paisner, J. D. Boyes, S. A. Kumpan, and M. Sorem, "The National Ignition Facility Project," ICF Quart. 5, 110 (1995)] hohlraums rely on multiple beam cones with different laser power temporal profiles in each cone. Experiments with multiple beam cones have begun on the Omega laser facility [T. R. Boehly et al., Opt. Commun. 133, 495 (1997)] at the University of Rochester. In addition to allowing symmetry experiments similar to those performed on Nova [A. Hauer et nl., Rev. Sci. Instrum. 66, 672 (1995)], the Omega facility allows multiple beam cones to be moved independently to confirm our ability to model the resulting implosion image shapes. Results indicate that hohlraum symmetry behaves similarly with multiple rings of beams as with a single ring, but with the weighted beam spot position used to parametrize the beam pointing. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. Univ Rochester, Laser Energet Lab, Rochester, NY 14627 USA. RP Murphy, TJ (reprint author), Univ Calif Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. RI Schnittman, Jeremy/D-3168-2012; Murphy, Thomas/F-3101-2014 OI Murphy, Thomas/0000-0002-6137-9873 NR 14 TC 16 Z9 17 U1 0 U2 5 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 1070-664X J9 PHYS PLASMAS JI Phys. Plasmas PD MAY PY 1998 VL 5 IS 5 SI SI BP 1960 EP 1965 DI 10.1063/1.872866 PN 2 PG 6 WC Physics, Fluids & Plasmas SC Physics GA ZN238 UT WOS:000073623700048 ER PT J AU Key, MH Cable, MD Cowan, TE Estabrook, KG Hammel, BA Hatchett, SP Henry, EA Hinkel, DE Kilkenny, JD Koch, JA Kruer, WL Langdon, AB Lasinski, BF Lee, RW MacGowan, BJ MacKinnon, A Moody, JD Moran, MJ Offenberger, AA Pennington, DM Perry, MD Phillips, TJ Sangster, TC Singh, MS Stoyer, MA Tabak, M Tietbohl, GL Tsukamoto, M Wharton, K Wilks, SC AF Key, MH Cable, MD Cowan, TE Estabrook, KG Hammel, BA Hatchett, SP Henry, EA Hinkel, DE Kilkenny, JD Koch, JA Kruer, WL Langdon, AB Lasinski, BF Lee, RW MacGowan, BJ MacKinnon, A Moody, JD Moran, MJ Offenberger, AA Pennington, DM Perry, MD Phillips, TJ Sangster, TC Singh, MS Stoyer, MA Tabak, M Tietbohl, GL Tsukamoto, M Wharton, K Wilks, SC TI Hot electron production and heating by hot electrons in fast ignitor research SO PHYSICS OF PLASMAS LA English DT Article; Proceedings Paper CT 39th Annual Meeting of the Division-of-Plasma-Physics of the American-Physical-Society CY NOV 17-21, 1997 CL PITTSBURGH, PENNSYLVANIA SP Amer Phys Soc, Div Plasma Phys ID LASER; NOVA AB In an experimental study of the physics of fast ignition, the characteristics of the hot electron source at laser intensities up to 10(20) W cm(-2) have been measured and a diagnosis of the heating at depth by hot electrons has been initiated. Generation of hot electrons with more than 30% efficiency has been observed. Preliminary heating data suggest temperatures kT in the range 300-800 eV. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Key, MH (reprint author), Univ Calif Lawrence Livermore Natl Lab, POB 808,L-473, Livermore, CA 94550 USA. RI MacKinnon, Andrew/P-7239-2014; Cowan, Thomas/A-8713-2011 OI MacKinnon, Andrew/0000-0002-4380-2906; Cowan, Thomas/0000-0002-5845-000X NR 16 TC 351 Z9 363 U1 2 U2 18 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 1070-664X J9 PHYS PLASMAS JI Phys. Plasmas PD MAY PY 1998 VL 5 IS 5 SI SI BP 1966 EP 1972 DI 10.1063/1.872867 PN 2 PG 7 WC Physics, Fluids & Plasmas SC Physics GA ZN238 UT WOS:000073623700049 ER PT J AU Montgomery, DS Afeyan, BB Cobble, JA Fernandez, JC Wilke, MD Glenzer, SH Kirkwood, RK MacGowan, BJ Moody, JD Lindman, EL Munro, DH Wilde, BH Rose, HA Dubois, DF Bezzerides, B Vu, HX AF Montgomery, DS Afeyan, BB Cobble, JA Fernandez, JC Wilke, MD Glenzer, SH Kirkwood, RK MacGowan, BJ Moody, JD Lindman, EL Munro, DH Wilde, BH Rose, HA Dubois, DF Bezzerides, B Vu, HX TI Evidence of plasma fluctuations and their effect on the growth of stimulated Brillouin and stimulated Raman scattering in laser plasmas SO PHYSICS OF PLASMAS LA English DT Article; Proceedings Paper CT 39th Annual Meeting of the Division-of-Plasma-Physics of the American-Physical-Society CY NOV 17-21, 1997 CL PITTSBURGH, PA SP Amer Phys Soc, Div Plasma Phys ID INHOMOGENEOUS-PLASMA; TARGETS; NOVA AB The reflectivity levels of stimulated Brillouin scattering (SBS) in recent large scale length laser plasma experiments is much lower than expected for conditions where the convective gain exponent is expected to be large [J. C. Fernandez et al., Phys. Plasmas 4, 1849 (1997)]. Long-wavelength velocity fluctuations caused during the plasma formation process, or by parametric instabilities themselves, have been proposed as a mechanism to detune SBS in these experiments and reduce its gain [W. L. Kruer et al., Phys. Plasmas 3, 382 (1996); H. A. Rose, Phys. Plasmas 4, 437 (1997)]. Evidence of large-velocity fluctuation levels is found in the time-resolved SBS spectra from these experiments, and correlates with observed changes in the reflectivity of both SBS and stimulated Raman scattering (SRS). Evidence of fluctuations that increase with increasing plasma density is : presented, and their effect on the growth of parametric instabilities is discussed. (C) 1998 American Institute of Physics. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Polymath Associates, Livermore, CA 94550 USA. Univ Nevada, Dept Phys, Reno, NV 89557 USA. Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. RP Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. RI Fernandez, Juan/H-3268-2011; OI Fernandez, Juan/0000-0002-1438-1815; Montgomery, David/0000-0002-2355-6242 NR 27 TC 59 Z9 61 U1 0 U2 8 PU AMER INST PHYSICS PI MELVILLE PA 1305 WALT WHITMAN RD, STE 300, MELVILLE, NY 11747-4501 USA SN 1070-664X EI 1089-7674 J9 PHYS PLASMAS JI Phys. Plasmas PD MAY PY 1998 VL 5 IS 5 SI SI BP 1973 EP 1980 DI 10.1063/1.872868 PN 2 PG 8 WC Physics, Fluids & Plasmas SC Physics GA ZN238 UT WOS:000073623700050 ER PT J AU Hartemann, FV AF Hartemann, FV TI High-intensity scattering processes of relativistic electrons in vacuum SO PHYSICS OF PLASMAS LA English DT Article; Proceedings Paper CT 39th Annual Meeting of the Division-of-Plasma-Physics of the American-Physical-Society CY NOV 17-21, 1997 CL PITTSBURGH, PENNSYLVANIA SP Amer Phys Soc, Div Plasma Phys ID COHERENT SYNCHROTRON-RADIATION; COMPTON-SCATTERING; WAVE-GUIDE; LASER; ACCELERATION; PLASMA; FREQUENCY AB Recent advances in novel technologies such as chirped pulse amplification and high gradient rf photoinjectors make it possible to study experimentally the interaction of relativistic electrons with ultrahigh intensity photon fields. Femtosecond laser systems operating in the TW-PW range are now available, as well as synchronized relativistic electron bunches with subpicosecond durations and THz bandwidths. Ponderomotive scattering can accelerate these electrons with extremely high gradients in a three-dimensional vacuum laser focus. The nonlinear Doppler shift induced by relativistic radiation pressure in Compton backscattering is shown to yield complex nonlinear spectra which can be modified by using temporal laser pulse shaping techniques. Colliding lasers pulses, where ponderomotive acceleration and Compton backscattering are combined, could also yield extremely short wavelength photons. Finally, strong radiative corrections are expected when the Doppler-upshifted laser wavelength approaches the Compton scale. These are discussed within the context of high field classical electrodynamics, a new discipline borne out of the aforementioned innovations. (C) 1998 American Institute of Physics. C1 Univ Calif Lawrence Livermore Natl Lab, Inst Laser Sci & Applicat, Livermore, CA 94550 USA. Univ Calif Davis, Dept Appl Sci, Livermore, CA 95616 USA. RP Hartemann, FV (reprint author), Univ Calif Lawrence Livermore Natl Lab, Inst Laser Sci & Applicat, Livermore, CA 94550 USA. EM fredh@gregor.llnl.gov NR 29 TC 47 Z9 47 U1 0 U2 5 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 1070-664X J9 PHYS PLASMAS JI Phys. Plasmas PD MAY PY 1998 VL 5 IS 5 SI SI BP 2037 EP 2047 DI 10.1063/1.872875 PN 2 PG 11 WC Physics, Fluids & Plasmas SC Physics GA ZN238 UT WOS:000073623700057 ER PT J AU Le Sage, GP Bennett, CV White, WE Landahl, EC Laurent, LL Luhmann, NC Hartemann, FV Ho, CH Lau, WK Yang, TT AF Le Sage, GP Bennett, CV White, WE Landahl, EC Laurent, LL Luhmann, NC Hartemann, FV Ho, CH Lau, WK Yang, TT TI High brightness, X-band photoinjector for the production of coherent synchrotron radiation SO PHYSICS OF PLASMAS LA English DT Article; Proceedings Paper CT 39th Annual Meeting of the Division-of-Plasma-Physics of the American-Physical-Society CY NOV 17-21, 1997 CL PITTSBURGH, PENNSYLVANIA SP Amer Phys Soc, Div Plasma Phys ID FREE-ELECTRON LASERS; WAVE-GUIDE; DRIVEN; DESIGN; FEL AB Linear colliders, future electron acceleration concepts, and short pulse, ultrawideband millimeter-wave sources all require bright electron beams. Photoinjectors have demonstrated the ability to produce relativistic electron beams with low emittance and energy spread. The system described herein combines state-of-the-art capabilities in the laser and rf systems, advanced photocathode materials? and new concepts for synchronization. Phase jitter has been measured in detail, and schemes for alleviating this problem have undergone initial proof-of-principle testing. Direct mode locking of a multiple quantum well Al:GaAs solid-state laser oscillator by an rf signal sampled from within a high-power rf accelerator cavity was demonstrated for the first time. Characterization of the electron beam produced by the system is presented. The linear electron accelerator system is comprised of a 1.5 cell side-wall coupled standing wave accelerator structure, driven by a 20 MW Stanford Linear Accelerator Center (SLAC) Klystron operating at 8.548 GHz, a Ti:sapphire laser oscillator, and a chirped pulse Ti:sapphire laser amplifier. (C) 1998 American Institute of Physics. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. Univ Calif Davis, Dept Appl Sci, Livermore, CA 95616 USA. Univ Calif Davis, Dept Appl Sci, Inst Laser Sci & Applicat, LLNL, Livermore, CA 94550 USA. Synchrotron Radiat Res Ctr, Hsinchu 3007, Taiwan. RP Le Sage, GP (reprint author), Univ Calif Lawrence Livermore Natl Lab, 7000 E Ave, Livermore, CA 94550 USA. EM lesage@wente.llnl.gov RI Bennett, Corey/C-2403-2009; Landahl, Eric/A-1742-2010 OI Bennett, Corey/0000-0003-4365-5739; NR 26 TC 7 Z9 7 U1 0 U2 5 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 1070-664X J9 PHYS PLASMAS JI Phys. Plasmas PD MAY PY 1998 VL 5 IS 5 SI SI BP 2048 EP 2054 DI 10.1063/1.872876 PN 2 PG 7 WC Physics, Fluids & Plasmas SC Physics GA ZN238 UT WOS:000073623700058 ER PT J AU Brownell, JH Bowers, RL McLenithan, KD Peterson, DL AF Brownell, JH Bowers, RL McLenithan, KD Peterson, DL TI Radiation environments produced by plasma z-pinch stagnation on central targets SO PHYSICS OF PLASMAS LA English DT Article; Proceedings Paper CT 39th Annual Meeting of the Division-of-Plasma-Physics of the American-Physical-Society CY NOV 17-21, 1997 CL PITTSBURGH, PA SP Amer Phys Soc, Div Plasma Phys AB A goal of pulsed-power technology is the development of an intense, megajoule level source of soft x rays for use in high-energy density physics experiments. Experimental facilities, theoretical concepts, computational tools, and diagnostics that have been developed since 1980 place pulsed power at the threshold of performing experiments of great interest to the applied physics community. In this paper the "Flying Radiation Case" approach will be presented and its predicted performance on Sandia National Laboratory's Z-Machine [M. K. Matzen, Phys. Plasmas 4, 1519 (1997)] will be described. The effects of instability growth in the plasma during the implosion, its reassembly on a central cushion, and the plasma interactions with shaped electrodes are considered. (C) 1998 American Institute of Physics. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. NR 24 TC 52 Z9 52 U1 0 U2 2 PU AMER INST PHYSICS PI MELVILLE PA 1305 WALT WHITMAN RD, STE 300, MELVILLE, NY 11747-4501 USA SN 1070-664X EI 1089-7674 J9 PHYS PLASMAS JI Phys. Plasmas PD MAY PY 1998 VL 5 IS 5 SI SI BP 2071 EP 2080 DI 10.1063/1.872879 PN 2 PG 10 WC Physics, Fluids & Plasmas SC Physics GA ZN238 UT WOS:000073623700061 ER PT J AU Chattopadhyay, S AF Chattopadhyay, S TI Alight a beam and beaming light: A theme with variations SO PHYSICS OF PLASMAS LA English DT Article; Proceedings Paper CT 39th Annual Meeting of the Division-of-Plasma-Physics of the American-Physical-Society CY NOV 17-21, 1997 CL PITTSBURGH, PENNSYLVANIA SP Amer Phys Soc, Div Plasma Phys ID 90-DEGREES THOMSON SCATTERING; X-RAY PULSES AB The interaction of light (coherent and incoherent) with charged particle beams is explored in various configurations: incoherent scattering of coherent light (laser) from an incoherent particle beam (high temperature), coherent scattering of coherent light (laser) from a "cold" (bunched) beam, femtosecond generation of particle and light beams via "optical slicing" and Thomson/Compton scattering techniques, etc. The domains of ultrashort temporal duration (femtoseconds) as well as ultrashort wavelengths (x rays and shorter), with varying degrees of coherence, are explored. The relevance to a few critical areas of research in the natural sciences, e.g., ultrafast material, chemical and biological processes, protein folding, particle phase space cooling, etc, are touched upon. All the processes discussed involve proper interpretation and understanding of coherent states of matter and radiation, as well as the quality and quantity of information and energy embedded in them. (C) 1998 American Institute of Physics. C1 Univ Calif Berkeley, Ernest Orlando Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. RP Chattopadhyay, S (reprint author), Univ Calif Berkeley, Ernest Orlando Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. EM s_chattopadhyay@lbl.gov NR 17 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 USA SN 1070-664X J9 PHYS PLASMAS JI Phys. Plasmas PD MAY PY 1998 VL 5 IS 5 SI SI BP 2081 EP 2089 DI 10.1063/1.872823 PN 2 PG 9 WC Physics, Fluids & Plasmas SC Physics GA ZN238 UT WOS:000073623700062 ER PT J AU Schoenberg, KF Gerwin, RA Moses, RW Scheuer, JT Wagner, HP AF Schoenberg, KF Gerwin, RA Moses, RW Scheuer, JT Wagner, HP TI Magnetohydrodynamic flow physics of magnetically nozzled plasma accelerators with applications to advanced manufacturing SO PHYSICS OF PLASMAS LA English DT Article; Proceedings Paper CT 39th Annual Meeting of the Division-of-Plasma-Physics of the American-Physical-Society CY NOV 17-21, 1997 CL PITTSBURGH, PENNSYLVANIA SP Amer Phys Soc, Div Plasma Phys ID PULSED ION-BEAMS; IMPULSE PLASMA; THRUSTER; CRYSTALLIZATION; LAYERS; MULTIMEGAWATT; SIMULATION; STEADY AB The coaxial plasma accelerator is a simple, compact, and mechanically robust device that utilizes the Lorentz JxB force to accelerate plasma to high velocity. Originally developed in the 1950s for the purpose of providing energetic plasmas for fusion energy experiments, coaxial plasma accelerators are presently being investigated as an environmentally sound and economical means of materials processing and advanced manufacturing. While commercial applications of this technology are already on line, future commercial applications will require improving accelerator reproducibility and efficiency, better controlling the accelerated plasma flow velocity or energy, and better controlling the distribution of directed energy or power on target. In this paper, the magnetohydrodynamic flow physics of magnetically nozzled plasma accelerators is presented with a view to achieving the accelerator control necessary for future industrial applications. Included is a fundamental description of plasma production, acceleration, and flow in a magnetic nozzle. (C) 1998 American Institute of Physics. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Schoenberg, KF (reprint author), Univ Calif Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. NR 45 TC 25 Z9 25 U1 0 U2 4 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 1070-664X J9 PHYS PLASMAS JI Phys. Plasmas PD MAY PY 1998 VL 5 IS 5 SI SI BP 2090 EP 2104 DI 10.1063/1.872880 PN 2 PG 15 WC Physics, Fluids & Plasmas SC Physics GA ZN238 UT WOS:000073623700063 ER PT J AU Spielman, RB Deeney, C Chandler, GA Douglas, MR Fehl, DL Matzen, MK McDaniel, DH Nash, TJ Porter, JL Sanford, TWL Seamen, JF Stygar, WA Struve, KW Breeze, SP McGurn, JS Torres, JA Zagar, DM Gilliland, TL Jobe, DO McKenney, JL Mock, RC Vargas, M Wagoner, T Peterson, DL AF Spielman, RB Deeney, C Chandler, GA Douglas, MR Fehl, DL Matzen, MK McDaniel, DH Nash, TJ Porter, JL Sanford, TWL Seamen, JF Stygar, WA Struve, KW Breeze, SP McGurn, JS Torres, JA Zagar, DM Gilliland, TL Jobe, DO McKenney, JL Mock, RC Vargas, M Wagoner, T Peterson, DL TI Tungsten wire-array Z-pinch experiments at 200 TW and 2 MJ SO PHYSICS OF PLASMAS LA English DT Article; Proceedings Paper CT 39th Annual Meeting of the Division-of-Plasma-Physics of the American-Physical-Society CY NOV 17-21, 1997 CL PITTSBURGH, PENNSYLVANIA SP Amer Phys Soc, Div Plasma Phys AB Here Z, a 60 TW/5 MJ electrical accelerator located at Sandia National Laboratories, has been used to implode tungsten wire-array Z pinches. These arrays consisted of large numbers of tungsten wires (120-300) with wire diameters of 7.5 to 15 mu m placed in a symmetric cylindrical array. The experiments used array diameters ranging from 1.75 to 4 cm and lengths from 1 to 2 cm. A 2 cm long, 4 cm diam tungsten array consisting of 240, 7.5 mu m diam wires (4.1 mg mass) achieved an x-ray power of similar to 200 TW and an x-ray energy of nearly 2 MJ. Spectral data suggest an optically thick, Planckian-like radiator below 1000 eV. One surprising experimental result was the observation that the total radiated x-ray energies and x-ray powers were nearly independent of pinch length. These data are compared with two-dimensional radiation magnetohydrodynamic code calculations. (C) 1998 American Institute of Physics. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Mission Res Corp, Albuquerque, NM 87106 USA. RP Spielman, RB (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. NR 20 TC 487 Z9 520 U1 1 U2 16 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 1070-664X J9 PHYS PLASMAS JI Phys. Plasmas PD MAY PY 1998 VL 5 IS 5 SI SI BP 2105 EP 2111 DI 10.1063/1.872881 PN 2 PG 7 WC Physics, Fluids & Plasmas SC Physics GA ZN238 UT WOS:000073623700064 ER PT J AU Hershcovitch, A AF Hershcovitch, A TI A plasma window for transmission of particle beams and radiation from vacuum to atmosphere for various applications SO PHYSICS OF PLASMAS LA English DT Article; Proceedings Paper CT 39th Annual Meeting of the Division-of-Plasma-Physics of the American-Physical-Society CY NOV 17-21, 1997 CL PITTSBURGH, PENNSYLVANIA SP Amer Phys Soc, Div Plasma Phys ID ARC PLASMA AB Many industrial and scientific processes like ion material modification, electron beam melting, and welding, as well as generation of synchrotron radiation are performed exclusively in vacuum nowadays, since electron guns, ion guns, their extractors, and accelerators must be kept at a reasonably high vacuum. Consequently, there are numerous limitations, among which are low production rates due to required pumping time, limits on the size of target objects, and degradation of particle beams and radiation through foils or differentially pumped sections. A novel apparatus, which utilized a short plasma are, was successfully used to provide a vacuum-atmosphere interface as an alternative to differential pumping. Successful transmission of charged particle beams from a vacuum through the plasma to atmosphere was accomplished. Included in the article are a theoretical framework, experimental results, and possible applications for this novel interface. (C) 1998 American Institute of Physics. C1 Brookhaven Natl Lab, Upton, NY 11973 USA. RP Hershcovitch, A (reprint author), Brookhaven Natl Lab, Upton, NY 11973 USA. NR 25 TC 31 Z9 31 U1 2 U2 8 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 1070-664X J9 PHYS PLASMAS JI Phys. Plasmas PD MAY PY 1998 VL 5 IS 5 SI SI BP 2130 EP 2136 DI 10.1063/1.872885 PN 2 PG 7 WC Physics, Fluids & Plasmas SC Physics GA ZN238 UT WOS:000073623700068 ER PT J AU Renk, TJ Buchheit, RG Sorensen, NR Senft, DC Thompson, MO Grabowski, KS AF Renk, TJ Buchheit, RG Sorensen, NR Senft, DC Thompson, MO Grabowski, KS TI Improvement of surface properties by modification and alloying with high-power ion beams SO PHYSICS OF PLASMAS LA English DT Article; Proceedings Paper CT 39th Annual Meeting of the Division-of-Plasma-Physics of the American-Physical-Society CY NOV 17-21, 1997 CL PITTSBURGH, PENNSYLVANIA SP Amer Phys Soc, Div Plasma Phys AB Surface treatment and alloying experiments with Al, Fe, and Ti-based metals as well as Si wafers were conducted on the Repetitive High Energy Pulsed Power-I (RHEPP-I) accelerator [0.8 MV, 20 Ohm, 80 ns full width at half maximum (FWHM) pulse width, up to 1 Hz repetition rate] at Sandia National Laboratories. Ions are generated by the magnetically confined anode plasma (MAP) gas-breakdown active anode, which can yield a number of different beam species including H, C, N, O, Kr, and Xe, depending upon the injected gas. Enhanced hardness and wear resistance have been produced by treatment of 440C stainless steel, by the mixing of a thin-film Pt coating into Ti-6Al-4V alloy, and of a Si coating into Al 6061-T6 alloy (Al-1.0Mg-0.6Si). Mixing of a thin-film Hf layer into Al 6061-T6 has improved its corrosion resistance by as much as four orders of magnitude in electrochemical testing, compared with untreated and uncoated Al6061. Processing of Si was used to validate simulation codes. When treated with nitrogen ions, melt and full epitaxial growth was observed to depths of 4-6 mu m. Experiments are ongoing to further understand the microstructural basis for these surface improvements. (C) 1998 American Institute of Physics. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. Cornell Univ, Dept Mat Sci, Ithaca, NY 14853 USA. USN, Res Lab, Washington, DC 20375 USA. RP Renk, TJ (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. OI Grabowski, Kenneth/0000-0003-0816-001X; Thompson, Michael/0000-0002-4933-009X NR 8 TC 24 Z9 26 U1 0 U2 2 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 1070-664X J9 PHYS PLASMAS JI Phys. Plasmas PD MAY PY 1998 VL 5 IS 5 SI SI BP 2144 EP 2150 DI 10.1063/1.872887 PN 2 PG 7 WC Physics, Fluids & Plasmas SC Physics GA ZN238 UT WOS:000073623700070 ER PT J AU Ruvimov, S Liliental-Weber, Z Washburn, J Ledentsov, NN Ustinov, VM Shchukin, VA Kop'ev, PS Alferov, ZI Bimberg, D AF Ruvimov, S Liliental-Weber, Z Washburn, J Ledentsov, NN Ustinov, VM Shchukin, VA Kop'ev, PS Alferov, ZI Bimberg, D TI Structural characterization of self-organized nanostructures SO PHYSICS OF THE SOLID STATE LA English DT Article; Proceedings Paper CT International Symposium Dedicated to the 100th Birthday of Evgenii Fedorovich Gross CY 1997 CL ST PETERSBURG, RUSSIA ID QUANTUM DOTS; GAAS MATRIX; STRAINED ISLANDS; GROWTH; SURFACES; SUPERLATTICES; EPITAXY; INGAAS AB Self-organized nano-objects fabricated in different semiconductor systems are currently at the focus of scientific interest because of their unique electronic properties. Transmission electron microscopy and high-resolution electron microscopy have been used to study the InAs quantum dots grown by molecular-beam epitaxy (MBE) on GaAs and InP substrates. Optimal imaging conditions for visualization of quantum dots were established. Size, shape, and stability of the equilibrium island arrays were analyzed with respect to the growth conditions. Both decrease and increase of the As pressure compared to the optimal value were shown to destroy the regular arrangement of the islands. Energy benefit due to the strain relaxation in the InAs islands is likely to be the driving force for their formation. (C) 1998 American Institute of Physics. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. AF Ioffe Phys Tech Inst, St Petersburg 194021, Russia. Tech Univ Berlin, D-10623 Berlin, Germany. RP Ruvimov, S (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RI Liliental-Weber, Zuzanna/H-8006-2012; Ustinov, Viktor/J-3545-2013 NR 21 TC 6 Z9 6 U1 0 U2 2 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 1063-7834 J9 PHYS SOLID STATE+ JI Phys. Solid State PD MAY PY 1998 VL 40 IS 5 BP 781 EP 783 DI 10.1134/1.1130394 PG 3 WC Physics, Condensed Matter SC Physics GA ZU507 UT WOS:000074205000022 ER PT J AU Synakowski, EJ AF Synakowski, EJ TI Formation and structure of internal and edge transport barriers SO PLASMA PHYSICS AND CONTROLLED FUSION LA English DT Article; Proceedings Paper CT 6th IAEA Technical Committee Meeting on H-Mode Physics CY SEP 22-24, 1997 CL KLOSTER SEEON, GERMANY SP IAEA ID REVERSED MAGNETIC SHEAR; HIGH CONFINEMENT MODE; L-H TRANSITION; DIII-D; POLOIDAL ROTATION; ELECTRIC-FIELD; JFT-2M TOKAMAK; FLOW SHEAR; TURBULENCE; BIFURCATION AB The phenomenology of transport barrier formation is reviewed with a focus on physics that may be common to the edge and the core. To this end, the framework of E x B velocity shear reduction of turbulence-induced fluxes, applied to the edge for some time, is studied in the light of measurements of core bifurcation dynamics and recent tests of causality. Also, the possible role of the magnetic shear structure in facilitating core barrier formation is examined. Experimental and theoretical challenges for developing a predictive capability for reactor-relevant conditions are highlighted by recent observations of spontaneous electric field shear generation far removed from edge effects, and efforts to characterize the plasma edge at and across the GH transition. C1 Princeton Plasma Phys Lab, Princeton, NJ 08543 USA. RP Synakowski, EJ (reprint author), Princeton Plasma Phys Lab, POB 451, Princeton, NJ 08543 USA. NR 79 TC 78 Z9 78 U1 3 U2 5 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0741-3335 J9 PLASMA PHYS CONTR F JI Plasma Phys. Control. Fusion PD MAY PY 1998 VL 40 IS 5 BP 581 EP 596 DI 10.1088/0741-3335/40/5/006 PG 16 WC Physics, Fluids & Plasmas SC Physics GA ZR833 UT WOS:000074019100006 ER PT J AU Bell, RE Levinton, FM Batha, SH Synakowski, EJ Zarnstorff, MC AF Bell, RE Levinton, FM Batha, SH Synakowski, EJ Zarnstorff, MC TI Core poloidal rotation and internal transport barrier formation in TFTR SO PLASMA PHYSICS AND CONTROLLED FUSION LA English DT Article; Proceedings Paper CT 6th IAEA Technical Committee Meeting on H-Mode Physics CY SEP 22-24, 1997 CL KLOSTER SEEON, GERMANY SP IAEA ID REVERSED MAGNETIC SHEAR; CONFINEMENT AB Impurity poloidal rotation velocities have been measured in the core of TFTR plasmas using a new spectroscopic diagnostic. Two types of transition to enhanced confinement in reversed shear plasmas are examined. A bifurcation in carbon poloidal rotation is observed to occur before the transition to enhanced confinement for one of these types, while other measured plasma parameters remain constant. A narrow radial region with reversed poloidal rotation and rotational shear is established 60-100 ms before the transition and is associated with a large negative radial electric field. C1 Princeton Plasma Phys Lab, Princeton, NJ 08543 USA. Fus Phys & Technol, Torrance, CA 90503 USA. RP Bell, RE (reprint author), Princeton Plasma Phys Lab, POB 451, Princeton, NJ 08543 USA. NR 8 TC 32 Z9 32 U1 0 U2 0 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0741-3335 J9 PLASMA PHYS CONTR F JI Plasma Phys. Control. Fusion PD MAY PY 1998 VL 40 IS 5 BP 609 EP 613 DI 10.1088/0741-3335/40/5/008 PG 5 WC Physics, Fluids & Plasmas SC Physics GA ZR833 UT WOS:000074019100008 ER PT J AU Efthimion, PC von Goeler, S Synakowski, EJ Bitter, M Batha, SH Bell, RE Bush, CE Houlberg, WA Levinton, FM Mazzucato, E McCune, D Mueller, D Park, H Ramsey, AT Roquemore, AL Taylor, G Zarnstorff, MC AF Efthimion, PC von Goeler, S Synakowski, EJ Bitter, M Batha, SH Bell, RE Bush, CE Houlberg, WA Levinton, FM Mazzucato, E McCune, D Mueller, D Park, H Ramsey, AT Roquemore, AL Taylor, G Zarnstorff, MC TI Observation of tritium and helium core transport barriers in reversed shear plasmas on TFTR SO PLASMA PHYSICS AND CONTROLLED FUSION LA English DT Article; Proceedings Paper CT 6th IAEA Technical Committee Meeting on H-Mode Physics CY SEP 22-24, 1997 CL KLOSTER SEEON, GERMANY SP IAEA ID MAGNETIC SHEAR; PARTICLE-TRANSPORT; CONFINEMENT AB Tritium and helium gas-puff experiments have been conducted on TFTR to investigate transport in reverse shear plasmas. Small amounts of tritium and helium gas are puffed into the equilibrium phase of these plasmas. Measurements of the 14 MeV t(d, n)alpha neutron fusion product and the charge-exchange spectrum of helium reveal the transport details of tritium and helium, respectively. The inferred tritium and helium density profiles indicate the formation of a core transport barrier for each species in reverse shear plasmas with enhanced confinement. C1 Princeton Univ, Princeton Plasma Phys Lab, Princeton, NJ 08543 USA. Fus Phys & Technol, Torrance, CA 90503 USA. ORNL, Oak Ridge, TN 37380 USA. RP Efthimion, PC (reprint author), Princeton Univ, Princeton Plasma Phys Lab, POB 451, Princeton, NJ 08543 USA. NR 10 TC 1 Z9 1 U1 0 U2 1 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0741-3335 J9 PLASMA PHYS CONTR F JI Plasma Phys. Control. Fusion PD MAY PY 1998 VL 40 IS 5 BP 621 EP 625 DI 10.1088/0741-3335/40/5/010 PG 5 WC Physics, Fluids & Plasmas SC Physics GA ZR833 UT WOS:000074019100010 ER PT J AU Sips, ACC Baranov, YF Challis, CD Cottrell, GA Eriksson, LG Gormezano, C Gowers, C Greenfield, CM de Haas, JCM von Hellermann, M Huysmans, GTA Howman, A Konig, R Lazarus, EA Luce, T Nielsen, P O'Brien, D Rice, BW Sadler, G Soldner, FX Stamp, MF Strait, EJ Tubbing, BJD Wade, M Ward, DJ AF Sips, ACC Baranov, YF Challis, CD Cottrell, GA Eriksson, LG Gormezano, C Gowers, C Greenfield, CM de Haas, JCM von Hellermann, M Huysmans, GTA Howman, A Konig, R Lazarus, EA Luce, T Nielsen, P O'Brien, D Rice, BW Sadler, G Soldner, FX Stamp, MF Strait, EJ Tubbing, BJD Wade, M Ward, DJ TI Internal transport barriers in optimized shear plasmas in JET SO PLASMA PHYSICS AND CONTROLLED FUSION LA English DT Article; Proceedings Paper CT 6th IAEA Technical Committee Meeting on H-Mode Physics CY SEP 22-24, 1997 CL KLOSTER SEEON, GERMANY SP IAEA ID REVERSED MAGNETIC SHEAR; ENHANCED PERFORMANCE; CONFINEMENT AB Experiments using high-power heating during the current nmp-up phase of the discharge have obtained the highest D-D neutron rates in JET; S-n = 5.6 x 10(16) neutrons s(-1) with n(e0), approximate to 6 x 10(19) m(-3), T-e0 approximate to 12 keV and T-i0 approximate to 26 keV. The best discharges (I-p = 3.3 MA and B-t = 3.4 tesla) have peaked pressure profiles with a transport barrier located at tau/a = 0.55. The pressure peaking is limited by MHD modes and requires active input power control to achieve the best performance. Deuterium neutral beam injection into a tritium-rich target plasma has established internal transport barriers at power levels close to the lowest threshold for pure deuterium plasmas. C1 Jet Joint Undertaking, Abingdon OX14 3EA, Oxon, England. Gen Atom Co, San Diego, CA 92186 USA. Oak Ridge Natl Lab, Oak Ridge, TN USA. Univ Calif Lawrence Livermore Natl Lab, Livermore, CA USA. RP Sips, ACC (reprint author), Jet Joint Undertaking, Abingdon OX14 3EA, Oxon, England. NR 9 TC 10 Z9 10 U1 1 U2 1 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0741-3335 J9 PLASMA PHYS CONTR F JI Plasma Phys. Control. Fusion PD MAY PY 1998 VL 40 IS 5 BP 647 EP 652 DI 10.1088/0741-3335/40/5/015 PG 6 WC Physics, Fluids & Plasmas SC Physics GA ZR833 UT WOS:000074019100015 ER PT J AU Hahm, TS Burrell, KH Greenfield, CM Synakowski, EJ AF Hahm, TS Burrell, KH Greenfield, CM Synakowski, EJ TI Effects of E-r/RB phi profiles on transport reduction in DIII-D and TFTR SO PLASMA PHYSICS AND CONTROLLED FUSION LA English DT Article; Proceedings Paper CT 6th IAEA Technical Committee Meeting on H-Mode Physics CY SEP 22-24, 1997 CL KLOSTER SEEON, GERMANY SP IAEA ID DRIFT-WAVE TURBULENCE; ELECTRIC-FIELD; TOKAMAK; SHEAR; ROTATION; PLASMAS AB A possible relation between the E x B flow curvature and the reduction of electron thermal diffusivity is discussed. We show that unlike the E x B flow shear, the E x B Row curvature has no universal effects on the evolution of the two-point correlation function. Since various instabilities respond differently to the E x B Row curvature, we can gain useful insights into the nature of the ambient turbulence responsible for the electron thermal transport by examining the E-tau/RBtheta profiles. Initial results from DIII-D and TFTR are discussed. C1 Princeton Plasma Phys Lab, Princeton, NJ 08543 USA. Gen Atom Co, San Diego, CA 92186 USA. RP Hahm, TS (reprint author), Princeton Plasma Phys Lab, POB 451, Princeton, NJ 08543 USA. NR 16 TC 11 Z9 11 U1 0 U2 1 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0741-3335 J9 PLASMA PHYS CONTR F JI Plasma Phys. Control. Fusion PD MAY PY 1998 VL 40 IS 5 BP 657 EP 660 DI 10.1088/0741-3335/40/5/017 PG 4 WC Physics, Fluids & Plasmas SC Physics GA ZR833 UT WOS:000074019100017 ER PT J AU Owen, LW Carreras, BA Maingi, R Mioduszewski, PK Carlstrom, TN Groebner, RJ AF Owen, LW Carreras, BA Maingi, R Mioduszewski, PK Carlstrom, TN Groebner, RJ TI Assessment of effects of neutrals on the power threshold for L-H transitions in DIII-D SO PLASMA PHYSICS AND CONTROLLED FUSION LA English DT Article; Proceedings Paper CT 6th IAEA Technical Committee Meeting on H-Mode Physics CY SEP 22-24, 1997 CL KLOSTER SEEON, GERMANY SP IAEA ID MODE TRANSITION; TOKAMAK AB To assess the effect of edge neutrals on the low-to-high confinement transition threshold, a broad range of plasma discharges has been analysed. From this analysis, the transition power divided by the density, at constant magnetic field, appears to be a function of a single parameter measuring the neutrals' effect. This results suggest that there is a missing parameter linked to the neutrals in the power-threshold scaling laws. C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. Gen Atom Co, San Diego, CA 92186 USA. RP Owen, LW (reprint author), Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. NR 25 TC 20 Z9 20 U1 0 U2 4 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0741-3335 J9 PLASMA PHYS CONTR F JI Plasma Phys. Control. Fusion PD MAY PY 1998 VL 40 IS 5 BP 717 EP 720 DI 10.1088/0741-3335/40/5/030 PG 4 WC Physics, Fluids & Plasmas SC Physics GA ZR833 UT WOS:000074019100030 ER PT J AU Osborne, TH Groebner, RJ Lao, LL Leonard, AW Maingi, R Miller, RL Porter, GD Thomas, DM Waltz, RE AF Osborne, TH Groebner, RJ Lao, LL Leonard, AW Maingi, R Miller, RL Porter, GD Thomas, DM Waltz, RE TI H-mode pedestal characteristics, ELMs, and energy confinement in ITER shape discharges on DIII-D SO PLASMA PHYSICS AND CONTROLLED FUSION LA English DT Article; Proceedings Paper CT 6th IAEA Technical Committee Meeting on H-Mode Physics CY SEP 22-24, 1997 CL KLOSTER SEEON, GERMANY SP IAEA AB The H-mode confinement enhancement factor, H, is found to be strongly correlated with the height of the edge pressure pedestal in ITER shape discharges. In discharges with type I edge-localized modes (ELMs) the pedestal pressure is set by the maximum pressure gradient before the ELM and the width of the H-mode transport barrier. The pressure gradient before type I ELMs is found to scale as would be expected fora stability limit set by ideal ballooning modes, but with values significantly in excess of that predicted by stability code calculations. The width of the H-mode transport barrier is found to scale equally well with pedestal rho POL2/3 or beta(POL)(1/2) The improved H value in high-beta(POL) discharges may be due to a larger edge pressure gradient and wider H-mode transport barrier consistent with their higher edge ballooning mode limit. Deuterium puffing is found to reduce H, which is consistent with the smaller pedestal pressure which results from the reduced barrier width and critical pressure gradient. Type I ELM energy loss is found to be proportional to the change in the pedestal energy. C1 Gen Atom Co, San Diego, CA 92186 USA. Univ Calif Lawrence Livermore Natl Lab, Livermore, CA USA. Oak Ridge Natl Lab, Oak Ridge, TN USA. RP Osborne, TH (reprint author), Gen Atom Co, POB 85608, San Diego, CA 92186 USA. NR 10 TC 55 Z9 56 U1 1 U2 5 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0741-3335 J9 PLASMA PHYS CONTR F JI Plasma Phys. Control. Fusion PD MAY PY 1998 VL 40 IS 5 BP 845 EP 850 DI 10.1088/0741-3335/40/5/054 PG 6 WC Physics, Fluids & Plasmas SC Physics GA ZR833 UT WOS:000074019100054 ER PT J AU Goyette, AN Lawler, JE Anderson, LW Gruen, DM McCauley, TG Zhou, D Krauss, AR AF Goyette, AN Lawler, JE Anderson, LW Gruen, DM McCauley, TG Zhou, D Krauss, AR TI C-2 swan band emission intensity as a function of C-2 density SO PLASMA SOURCES SCIENCE & TECHNOLOGY LA English DT Article ID DIAMOND-FILM GROWTH AB We report the systematic comparison of the optical emission intensity of the d(3) Pi --> a(3) Pi (0, 0) vibrational band of the C-2 Swan system with the absolute C-2 concentration in Ar/H-2/CH4 and Ar/H-2/C-60 microwave plasmas used in the deposition of nanocrystalline diamond. The absolute C-2 concentration is obtained using white-light absorption spectroscopy. Emission intensity correlates linearly with C-2 density for variations of several plasma parameters and across two decades of species concentration. Although optical emission intensity generally is not an accurate quantitative diagnostic for gas phase species concentrations, these results confirm the reliability of the (0,0) Swan band for relative determination of Cp density with high sensitivity under conditions used for hydrogen-deficient plasma-enhanced chemical vapour deposition of diamond. C1 Univ Wisconsin, Dept Phys, Madison, WI 53706 USA. Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. Argonne Natl Lab, Div Chem, Argonne, IL 60439 USA. RP Goyette, AN (reprint author), Univ Wisconsin, Dept Phys, 1150 Univ Ave, Madison, WI 53706 USA. NR 8 TC 51 Z9 54 U1 0 U2 14 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0963-0252 J9 PLASMA SOURCES SCI T JI Plasma Sources Sci. Technol. PD MAY PY 1998 VL 7 IS 2 BP 149 EP 153 DI 10.1088/0963-0252/7/2/009 PG 5 WC Physics, Fluids & Plasmas SC Physics GA ZT125 UT WOS:000074050900008 ER PT J AU Bruce, JE Smith, VF Liu, CL Randall, LL Smith, RD AF Bruce, JE Smith, VF Liu, CL Randall, LL Smith, RD TI The observation of chaperone-ligand noncovalent complexes with electrospray ionization mass spectrometry SO PROTEIN SCIENCE LA English DT Article DE dissociation; Fourier transform ion cyclotron resonance; MS/MS; OppA; protein export; SecB; stoichiometry ID BINDING PROTEIN; PEPTIDE BINDING; ION-SOURCE; SECB; DNA; DISSOCIATION; BIOMOLECULES; RECOGNITION; PREPROTEIN; SAMPLES AB Fourier transform ion cyclotron resonance mass spectrometry (FTICR-MS) was applied for the study of noncovalent chaperone SecB-ligand complexes produced in solution and examined in the gas phase with the aid of electrospray ionization (ESI). Since chaperone proteins are believed to recognize and bind only with ligands with nonnative tertiary structure, this work required careful unfolding of the ligand and subsequent reaction with the intact chaperone (the noncovalent tetrameric protein, SecB). A high denaturant concentration was employed to produce nonnative structures of the OppA, and microdialysis of the resulting solutions containing the chaperone-ligand complexes was carried out to rapidly remove the denaturant prior to analysis. Multistage mass spectrometry was essential to the successful study of these complexes since the initial mass spectra indicated extensive adduction that precluded mass measurements, even after microdialysis. However, low energy collisional activation of the ions in the FTICR trap proved useful for adduct removal, and careful control of excitation level preserved the intact complexes of interest, revealing a 1:1 SecB:OppA stoichiometry. To our knowledge, these results present the first direct observation of chaperone-ligand noncovalent complexes and the highest molecular weight heterogeneous noncovalent complex observed to date by mass spectrometry. Furthermore, these results highlight the capabilities of FTICR for the study of such complex systems, and the development of a greater understanding of chaperone interactions in protein export. C1 Pacific NW Natl Lab, Environm & Mol Sci Lab, Richland, WA 99352 USA. Washington State Univ, Dept Biochem & Biophys, Pullman, WA 99164 USA. RP Smith, RD (reprint author), Pacific NW Natl Lab, Environm & Mol Sci Lab, Richland, WA 99352 USA. RI Smith, Richard/J-3664-2012 OI Smith, Richard/0000-0002-2381-2349 FU NIGMS NIH HHS [GM29798, T32 GM08336] NR 38 TC 35 Z9 37 U1 0 U2 3 PU CAMBRIDGE UNIV PRESS PI NEW YORK PA 40 WEST 20TH STREET, NEW YORK, NY 10011-4211 USA SN 0961-8368 J9 PROTEIN SCI JI Protein Sci. PD MAY PY 1998 VL 7 IS 5 BP 1180 EP 1185 PG 6 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA ZL552 UT WOS:000073445800012 PM 9605322 ER PT J AU Baker, C AF Baker, C TI Smoothing a robotic design SO R&D MAGAZINE LA English DT Editorial Material C1 Pacific NW Lab, Richland, WA 99352 USA. RP Baker, C (reprint author), Pacific NW Lab, POB 999, Richland, WA 99352 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU CAHNERS-DENVER PUBLISHING CO PI OAK BROOK PA 2000 CLEARWATER DR, OAK BROOK, IL 60523-8809 USA SN 0746-9179 J9 R&D MAG JI R D Mag. PD MAY PY 1998 VL 40 IS 6 BP 65 EP 65 PG 1 WC Engineering, Industrial; Multidisciplinary Sciences SC Engineering; Science & Technology - Other Topics GA ZP224 UT WOS:000073730400012 ER PT J AU Carnes, BA Olshansky, SJ Grahn, D AF Carnes, BA Olshansky, SJ Grahn, D TI An interspecies prediction of the risk of radiation-induced mortality SO RADIATION RESEARCH LA English DT Article ID SENESCENCE AB Mortality data for B6CF(1) mice exposed to Co-60 gamma rays for the duration of life were used to make quantitative predictions of age-specific mortality observed in comparably exposed beagles. Simple Kaplan-Meier survival curves for the beagles and their 95% confidence intervals were computed for each dose-rate group observed. A dose-response equation was estimated from the mortality data for mice using a proportional hazard model. The dose-response model for mice was then used to generate predicted survivorship curves at dose rates that would recreate the dose burdens observed in the beagle at comparable points within the life span of the two organisms. When these predicted survivorship curves were scaled to adjust for species differences in the life span of control animals, the predictions for the mouse fell within the confidence intervals observed for the beagle. The successful interspecies extrapolation of age-specific mortality risks for species as different as the mouse and dog enhances both the value of studies involving laboratory animals and the potential relevance of the animal studies to the prediction of health effects in humans. (C) 1998 by Radiation Research Society. C1 Argonne Natl Lab, Ctr Mechanist Biol & Biotechnol, Argonne, IL 60439 USA. Univ Chicago, Dept Med, Chicago, IL 60637 USA. RP Carnes, BA (reprint author), Argonne Natl Lab, Ctr Mechanist Biol & Biotechnol, 9700 S Cass Ave, Argonne, IL 60439 USA. FU NIA NIH HHS [AG-00577-01] NR 47 TC 17 Z9 18 U1 0 U2 2 PU RADIATION RESEARCH SOC PI OAK BROOK PA 2021 SPRING RD, STE 600, OAK BROOK, IL 60521 USA SN 0033-7587 J9 RADIAT RES JI Radiat. Res. PD MAY PY 1998 VL 149 IS 5 BP 487 EP 492 DI 10.2307/3579789 PG 6 WC Biology; Biophysics; Radiology, Nuclear Medicine & Medical Imaging SC Life Sciences & Biomedicine - Other Topics; Biophysics; Radiology, Nuclear Medicine & Medical Imaging GA ZK825 UT WOS:000073367500011 PM 9588360 ER PT J AU Venkataraman, CT Lang, JC Nelson, CS Srajer, G Haeffner, DR Shastri, SD AF Venkataraman, CT Lang, JC Nelson, CS Srajer, G Haeffner, DR Shastri, SD TI A high energy phase retarder for the simultaneous production of right- and left-handed circularly polarized x rays SO REVIEW OF SCIENTIFIC INSTRUMENTS LA English DT Article ID CRYSTAL AB We have fabricated and characterized the performance of a monolithic Ge Bragg-Laue phase retarder capable of simultaneously producing both right-and left-handed circularly polarized x rays. The energy range of operation of the phase retarder is between 50 and 100 keV making it well suited to the measurement of spin-dependent Compton profiles within the impulse approximation, primarily because of the increased momentum resolution and larger Compton scattering cross section available at these higher incident energies. Although the phase retarder was optimized for operation at 86 keV, it can produce highly circularly polarized x rays over a substantial energy range. The performance of the phase retarder was tested via magnetic Compton scattering measurements on an Fe sample at the undulator A of the Advanced Photon Source. It was found to perform well in terms of flux and degree of circular polarization thereby greatly reducing the data collection times required for this inherently weak scattering process. (C) 1998 American Institute of Physics. C1 Argonne Natl Lab, Adv Photon Source, Argonne, IL 60439 USA. RP Venkataraman, CT (reprint author), Argonne Natl Lab, Adv Photon Source, Argonne, IL 60439 USA. NR 8 TC 4 Z9 4 U1 0 U2 2 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0034-6748 J9 REV SCI INSTRUM JI Rev. Sci. Instrum. PD MAY PY 1998 VL 69 IS 5 BP 1970 EP 1973 DI 10.1063/1.1148882 PG 4 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA ZN403 UT WOS:000073642400009 ER PT J AU Edwards, BC Buchwald, MI Epstein, RI AF Edwards, BC Buchwald, MI Epstein, RI TI Development of the Los Alamos solid-state optical refrigerator SO REVIEW OF SCIENTIFIC INSTRUMENTS LA English DT Article ID CONVERSION AB Laser-induced cooling of a solid by net anti-Stokes fluorescence, first experimentally demonstrated in 1995, can be the basis of a new type of cryocooler, an optical refrigerator. This article describes the physics and design issues of a practical optical refrigerator for operation at 77 K. In particular, the Los Alamos Solid-State Optical Refrigerator (LASSOR) which we are developing would have an operating efficiency comparable to commercial small cryocoolers, be completely vibration-free and operate for years without maintenance. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Edwards, BC (reprint author), Univ Calif Los Alamos Natl Lab, Mail Stop D436, Los Alamos, NM 87545 USA. OI Epstein, Richard/0000-0002-3929-4363 NR 13 TC 35 Z9 39 U1 0 U2 3 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0034-6748 J9 REV SCI INSTRUM JI Rev. Sci. Instrum. PD MAY PY 1998 VL 69 IS 5 BP 2050 EP 2055 DI 10.1063/1.1148897 PG 6 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA ZN403 UT WOS:000073642400024 ER PT J AU Tsang, CF Neretnieks, I AF Tsang, CF Neretnieks, I TI Flow channeling in heterogeneous fractured rocks SO REVIEWS OF GEOPHYSICS LA English DT Review ID TRACER TRANSPORT; SOLUTE TRANSPORT; SINGLE FRACTURE; MIGRATION EXPERIMENT; POROUS-MEDIA; FIELD DATA; MODEL; NETWORK; TESTS; CALIBRATION AB Experimental observations and theoretical studies over the last 10 years or so have demonstrated that flow channeling or preferred flow paths is a common phenomenon in fractured rocks. The reason it has come to the forefront of scientific investigation is the recent interest in predicting solute transport in geological media as part of safety assessment of geologic isolation of nuclear or toxic wastes. Solute transport is much more sensitive to medium heterogeneity than is temperature or pressure. In this paper, experimental observations of tracer transport over distances ranging from centimeters' to hundreds of meters are reviewed, and theoretical efforts to explain or model these observations are summarized. Processes that may explain some of the experimental observations without the use of flow-channeling models are discussed. The paper concludes with a discussion of the implications of flow channeling on the practical problems related to contaminant transport in geologic systems. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Div Earth Sci, Berkeley, CA 94720 USA. Royal Inst Technol, Dept Chem Engn, S-10044 Stockholm, Sweden. RP Tsang, CF (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Div Earth Sci, Berkeley, CA 94720 USA. EM cftsang@lbl.gov NR 71 TC 133 Z9 138 U1 1 U2 19 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 8755-1209 J9 REV GEOPHYS JI Rev. Geophys. PD MAY PY 1998 VL 36 IS 2 BP 275 EP 298 DI 10.1029/97RG03319 PG 24 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 126CW UT WOS:000076276200005 ER PT J AU Aksyuk, V Balakirev, FF Boebinger, GS Gammel, PL Haddon, RC Bishop, DJ AF Aksyuk, V Balakirev, FF Boebinger, GS Gammel, PL Haddon, RC Bishop, DJ TI Micromechanical "trampoline" magnetometers for use in large pulsed magnetic fields SO SCIENCE LA English DT Article ID KAPPA-(BEDT-TTF)(2)CU(NCS)(2) AB A silicon micromechanical magnetometer was constructed and successfully used in 60-tesla pulsed magnetic fields of less than 100-millisecond duration. The device is small, inexpensive to fabricate, and easy to use. It features a fast mechanical response (up to 50,000 hertz) and extremely high sensitivity yet is relatively robust against electrical and mechanical noise. Quantum oscillations in the magnetization of a 1-microgram sam pie of an organic superconductor, K-[bis(ethylenedithio)tetrathiafulvalene](2)Cu(NCS)(2), have been observed with this device. C1 AT&T Bell Labs, Lucent Technol, Murray Hill, NJ 07974 USA. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Aksyuk, V (reprint author), AT&T Bell Labs, Lucent Technol, 600 Mt Ave, Murray Hill, NJ 07974 USA. RI Haddon, Robert/A-2528-2008; OI Haddon, Robert/0000-0002-7903-5139; Aksyuk, Vladimir/0000-0002-9653-4722 NR 7 TC 22 Z9 22 U1 0 U2 7 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 MAY 1 PY 1998 VL 280 IS 5364 BP 720 EP 722 DI 10.1126/science.280.5364.720 PG 3 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA ZL268 UT WOS:000073415600042 ER PT J AU Benzi, M Tuma, M AF Benzi, M Tuma, M TI A sparse approximate inverse preconditioner for nonsymmetric linear systems SO SIAM JOURNAL ON SCIENTIFIC COMPUTING LA English DT Article DE preconditioning; approximate inverses; sparse linear systems; sparse matrices; incomplete factorizations; conjugate gradient-type methods ID CONJUGATE-GRADIENT METHOD; MATRIX; FACTORIZATIONS AB This paper is concerned with a new approach to preconditioning for large, sparse linear systems. A procedure for computing an incomplete factorization of the inverse of a nonsymmetric matrix is developed, and the resulting factorized sparse approximate inverse is used as an explicit preconditioner for conjugate gradient-type methods. Some theoretical properties of the preconditioner are discussed, and numerical experiments on test matrices from the Harwell-Boeing collection and from Tim Davis's collection are presented. Our results indicate that the new preconditioner is cheaper to construct than other approximate inverse preconditioners. Furthermore, the new technique insures convergence rates of the preconditioned iteration which are comparable with those obtained with standard implicit preconditioners. C1 Los Alamos Natl Lab, Sci Comp Grp CIC19, Los Alamos, NM 87545 USA. Acad Sci Czech Republic, Inst Comp Sci, Prague 18207 8, Czech Republic. RP Benzi, M (reprint author), Los Alamos Natl Lab, Sci Comp Grp CIC19, MS B256, Los Alamos, NM 87545 USA. EM benzi@lanl.gov; tuma@uivt.cas.cz RI Tuma, Miroslav/A-5946-2014 OI Tuma, Miroslav/0000-0003-2808-6929 NR 57 TC 171 Z9 180 U1 3 U2 9 PU SIAM PUBLICATIONS PI PHILADELPHIA PA 3600 UNIV CITY SCIENCE CENTER, PHILADELPHIA, PA 19104-2688 USA SN 1064-8275 J9 SIAM J SCI COMPUT JI SIAM J. Sci. Comput. PD MAY PY 1998 VL 19 IS 3 BP 968 EP 994 DI 10.1137/S1064827595294691 PG 27 WC Mathematics, Applied SC Mathematics GA ZH068 UT WOS:000073068900012 ER PT J AU Figueroa, E Lawrence, JM Sarrao, JL Fisk, Z Hundley, MF Thompson, JD AF Figueroa, E Lawrence, JM Sarrao, JL Fisk, Z Hundley, MF Thompson, JD TI Hall effect in YbXCu4 and the role of carrier density in the YbInCu4 valence transition SO SOLID STATE COMMUNICATIONS LA English DT Article DE electronic band structure; electronic transport; heavy fermions ID X-RAY-DIFFRACTION; HIGH-PRESSURE; YB; CE; YBXIN1-XCU2; YTTERBIUM; BEHAVIOR; NEUTRON; LUINCU4 AB An unrealistically large value of the Gruneisen parameter is required to explain the valence transition which occurs at 42 K in YbInCu4 as due to a Kondo Volume Collapse. A hint as to the origin of the transition lies in the large change in carrier density which occurs at the transition, from trivalent semimetallic behavior at high temperature to mixed valent metallic behavior at low temperature. In this paper we report measurements of the Hall coefficient R-H for temperatures in the range 15-300 K for a series of RXCu4 compounds (R = Yb, Lu and X = Au, Zn, Cd, Mg, Tl) that form in the cubic C15b structure. For all X the Hail coefficients are small (similar to 10(-10) m(3)/C) so that the transport appears to be metallic. The observation that low carrier density is unique to RInCu4 leads us to hypothesize that the valence transition (which is also unique to YbInCu4) is connected with the existence of a quasigap, which is a common feature of the band structure of RXCu4. The quasigap allows for two competing hybridization states of the 4f electrons: a small T-K semimetallic state and a large T-K metallic state. (C) 1998 Elsevier Science Ltd. All rights reserved. C1 Univ Calif Irvine, Irvine, CA 92697 USA. Florida State Univ, Tallahassee, FL 32306 USA. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Lawrence, JM (reprint author), Univ Calif Irvine, Irvine, CA 92697 USA. NR 24 TC 29 Z9 29 U1 2 U2 5 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 MAY PY 1998 VL 106 IS 6 BP 347 EP 351 DI 10.1016/S0038-1098(98)00042-8 PG 5 WC Physics, Condensed Matter SC Physics GA ZQ965 UT WOS:000073921100006 ER PT J AU Lee, JW Abernathy, CR Pearton, SJ Ren, F Constantine, C Barratt, C Shul, RJ AF Lee, JW Abernathy, CR Pearton, SJ Ren, F Constantine, C Barratt, C Shul, RJ TI Comparison of dry etch damage in GaAs/AlGaAs heterojunction bipolar transistors exposed to ECR and ICP Ar plasmas SO SOLID-STATE ELECTRONICS LA English DT Article ID INGAAS AB A detailed study has been performed of the damage introduced into GaAs/AlGaAs heterojunction bipolar transistors (HBT) during exposure to two different types of high ion density plasma used for mesa formation during device fabrication, namely electron cyclotron resonance (ECR) and inductively coupled plasma (ICP). Base and emitter sheet resistance increase with plasma source power in both systems until well-defined values where the ion energy falls below threshold values for defect creation. Under these conditions there is no measurable effect on device layer sheet resistance, de current gain or base-collector reverse breakdown voltage. The basic reason for this window of damage-free processing conditions is identified as the suppression of cathode self-bias as the high-density plasma source power is increased. Ion energy, ion flux and plasma exposure time may all have an effect on HBT device parameters. (C) 1998 Elsevier Science Ltd. All rights reserved. C1 Univ Florida, Dept Mat Sci & Engn, Gainesville, FL 32611 USA. Univ Florida, Dept Chem Engn, Gainesville, FL 32611 USA. Plasma Therm IP, St Petersburg, FL 33716 USA. Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Lee, JW (reprint author), Univ Florida, Dept Mat Sci & Engn, Gainesville, FL 32611 USA. NR 21 TC 6 Z9 6 U1 4 U2 7 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0038-1101 J9 SOLID STATE ELECTRON JI Solid-State Electron. PD MAY PY 1998 VL 42 IS 5 BP 733 EP 742 DI 10.1016/S0038-1101(97)00247-5 PG 10 WC Engineering, Electrical & Electronic; Physics, Applied; Physics, Condensed Matter SC Engineering; Physics GA ZT931 UT WOS:000074142500008 ER PT J AU Ren, F Kopf, RF Kuo, JM Lothian, JR Lee, JW Pearton, SJ Shul, RJ Constantine, C Johnson, D AF Ren, F Kopf, RF Kuo, JM Lothian, JR Lee, JW Pearton, SJ Shul, RJ Constantine, C Johnson, D TI Effect of high density H-2 plasmas on InGaP/GaAs and AlGaAs/GaAs HEMTs SO SOLID-STATE ELECTRONICS LA English DT Article ID III-V-SEMICONDUCTORS; CRYSTALLINE SEMICONDUCTORS; HYDROGEN INCORPORATION; GATE RECESS; GAAS; ETCH; HETEROJUNCTION; MIXTURES; CCL2F2; INP AB InGaP/GaAs and AlGaAs/GaAs high electron mobility transistors have been exposed to inductively coupled plasma or electron cyclotron resonance H-2 plasmas as a function of pressure; source power and rf chuck power. The transconductance, gate ideality factor and saturated drain-source current are all degraded by the plasma treatment. Two mechanisms are identified: passivation of Si dopants in the InGaP or AlGaAs donor layers by H-o and lattice disorder created by H+ and H-2(+) ion bombardment. HEMTs are found to be more susceptible to plasma-induced degradation than heterojunction bipolar transistors. Published by Elsevier Science Ltd. All rights reserved. C1 Univ Florida, Dept Chem Engn, Gainesville, FL 32611 USA. AT&T Bell Labs, Lucent Technol, Murray Hill, NJ 07974 USA. Univ Florida, Dept Mat Sci & Engn, Gainesville, FL 32611 USA. Sandia Natl Labs, Albuquerque, NM 87185 USA. Plasma Therm Inc, St Petersburg, FL 33716 USA. RP Ren, F (reprint author), Univ Florida, Dept Chem Engn, Gainesville, FL 32611 USA. RI Schaff, William/B-5839-2009 NR 24 TC 10 Z9 10 U1 0 U2 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0038-1101 J9 SOLID STATE ELECTRON JI Solid-State Electron. PD MAY PY 1998 VL 42 IS 5 BP 749 EP 753 DI 10.1016/S0038-1101(97)00292-X PG 5 WC Engineering, Electrical & Electronic; Physics, Applied; Physics, Condensed Matter SC Engineering; Physics GA ZT931 UT WOS:000074142500010 ER PT J AU Agarwal, A Gossmann, HJ Eaglesham, DJ Pelaz, L Herner, SB Jacobson, DC Haynes, TE Simonton, R AF Agarwal, A Gossmann, HJ Eaglesham, DJ Pelaz, L Herner, SB Jacobson, DC Haynes, TE Simonton, R TI Damage, defects and diffusion from ultra-low energy (0-5 keV) ion implantation of silicon SO SOLID-STATE ELECTRONICS LA English DT Article ID ANOMALOUS TRANSIENT DIFFUSION; ENHANCED DIFFUSION; DOPANT DIFFUSION; SI; BORON; MODEL; FILMS; INTERSTITIALS; EPITAXY AB Continued use of ion implantation for doping of silicon integrated circuits will soon require implantation energies below 5 keV to form electrical junctions less than 50 nm deep, At such low energies, dopant diffusion and formation of extended defects is modified by both the proximity of the surface and by the large volume concentrations of point defects and dopant atoms that arise from reduced range straggling. This brief review summarizes bur recent experiments which measured defect formation and evolution, as well as enhanced diffusion, in silicon implanted with Si+ and B+ ions at energies as low as 0.5 keV. The results have demonstrated that {311}-type extended defects are generated from Si+ implants even within 3 nm of the surface. However, when these defects eventually dissolve, the surface acts as a perfect sink to efficiently annihilate the released interstitials. As a result, the amount of TED from Si+ implantation measured by epitaxially-grown B markers decreases approximately linearly with decreasing ion energy. For sub-keV B+ implants typical doses currently used for source-drain doping lead to a boron diffusion enhancement of 3-4x despite the proximity of the surface. Enhanced diffusion is also observed from molecular beam-deposited silicon layers containing a high boron concentration, This newly emerged diffusion enhancement mechanism, boron-enhanced-diffusion (BED), is associated with the formation of a fine-grain polycrystalline silicon boride phase in the implanted layer during activation annealing, These investigations of ultra-low energy (ULE) implantation have thus reinforced and validated our understanding of the role of implantation damage in enhancing dopant diffusion in silicon, while simultaneously revealing some important new materials issues which will impact semiconductor processing in coming device generations. (C) 1998 Elsevier Science Ltd. All rights reserved. C1 AT&T Bell Labs, Lucent Technol, Murray Hill, NJ 07974 USA. Oak Ridge Natl Lab, Div Solid State, Oak Ridge, TN 37831 USA. Eaton Corp, Beverly, MA 01915 USA. RP Agarwal, A (reprint author), Eaton Corp, 55 Cherry Hill Dr, Beverly, MA 01915 USA. RI Pelaz, Lourdes/M-1766-2014; Haynes, Tony/P-8932-2015 OI Haynes, Tony/0000-0003-2871-4745 NR 32 TC 1 Z9 1 U1 0 U2 5 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0038-1101 J9 SOLID STATE ELECTRON JI Solid-State Electron. PD MAY PY 1998 VL 42 IS 5 BP A17 EP A25 PG 9 WC Engineering, Electrical & Electronic; Physics, Applied; Physics, Condensed Matter SC Engineering; Physics GA ZT931 UT WOS:000074142500031 ER PT J AU Aydil, ES Quiniou, BOM Lee, JTC Gregus, JA Gottscho, RA AF Aydil, ES Quiniou, BOM Lee, JTC Gregus, JA Gottscho, RA TI Incidence angle distributions of ions bombarding grounded surfaces in high density plasma reactors SO SOLID-STATE ELECTRONICS LA English DT Article ID CYCLOTRON RESONANCE PLASMA; LOW-PRESSURE; ENERGY-DISTRIBUTIONS; GLOW-DISCHARGES; TRANSPORT; PARTICLES; SUBSTRATE; ELECTRODE AB Ion incidence angle distribution on surfaces in plasma etching reactors determines the shape evolution of via holes and trenches through its effects on the spatial variation of ion fluxes along the walls of these microscopic features, We describe a novel retarding-field energy analyzer design that is capable of measuring the energy and the incidence angle distributions of ions bombarding grounded surfaces in plasma reactors with sub-0.5 degrees resolution. Using this analyzer we measured the energy and angle distributions of Ar ions incident onto a Si surface in a low-pressure helicon wave excited Ar plasma. Ion angle distributions are approximately Gaussian. In absence of collisions in the sheath, the width of the ion angle distribution function is determined by the ratio of the directed energy gained in the sheath to the random ion energy in the plasma. Variation of the ion angle distribution width as a function of plasma power and pressure is determined by the dependence of the sheath potential and the ion temperature on these externally controlled parameters. In low pressure Ar plasmas, the ion angle distribution broadens with increasing power and shows a maximum as a function of pressure in the range 0.5-4 mTorr. (C) 1998 Elsevier Science Ltd. All rights reserved. C1 Univ Calif Santa Barbara, Dept Chem Engn, Santa Barbara, CA 93106 USA. Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. AT&T Bell Labs, Lucent Technol, Murray Hill, NJ 07974 USA. Lam Res Corp, Fremont, CA 94538 USA. RP Aydil, ES (reprint author), Univ Calif Santa Barbara, Dept Chem Engn, Santa Barbara, CA 93106 USA. NR 30 TC 4 Z9 4 U1 1 U2 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0038-1101 J9 SOLID STATE ELECTRON JI Solid-State Electron. PD MAY PY 1998 VL 42 IS 5 BP A75 EP A82 PG 8 WC Engineering, Electrical & Electronic; Physics, Applied; Physics, Condensed Matter SC Engineering; Physics GA ZT931 UT WOS:000074142500036 ER PT J AU Lee, JW Lambers, ES Abernathy, CR Pearton, SJ Shul, RJ Ren, F Hobson, WS Constantine, C AF Lee, JW Lambers, ES Abernathy, CR Pearton, SJ Shul, RJ Ren, F Hobson, WS Constantine, C TI Inductively coupled plasma etching of III-V semiconductors in Cl-2-based chemistries SO SOLID-STATE ELECTRONICS LA English DT Article DE etching; compound semiconductors ID INP; GAAS AB Inductively coupled plasma (ICP) etching of all of the main III-V compound semiconductors is reported as a function of source and chuck power, pressure and gas additive (Ar, N-2, H-2) in Cl-2 plasmas. Etch rates between 2000 and 5000 Angstrom min(-1) were obtained for all materials at moderate source power (750 W) and low d.c, self-bias (less than or equal to -150 V). Surface morphologies were smooth over a broad range of conditions for Ga-based materials, while for In-based semiconductors there was a much narrower window of appropriate ion-to-neutral ratios to obtain smooth etched surfaces on In-based semiconductors. (C) 1998 Elsevier Science Ltd. All rights reserved. C1 Univ Florida, Dept Mat Sci & Engn, Gainesville, FL 32611 USA. Sandia Natl Labs, Albuquerque, NM 87185 USA. AT&T Bell Labs, Lucent Technol, Murray Hill, NJ 07974 USA. Plasma Therm Inc, St Petersburg, FL 33716 USA. RP Lee, JW (reprint author), Univ Florida, Dept Mat Sci & Engn, Gainesville, FL 32611 USA. NR 28 TC 3 Z9 3 U1 0 U2 3 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0038-1101 J9 SOLID STATE ELECTRON JI Solid-State Electron. PD MAY PY 1998 VL 42 IS 5 BP A65 EP A73 PG 9 WC Engineering, Electrical & Electronic; Physics, Applied; Physics, Condensed Matter SC Engineering; Physics GA ZT931 UT WOS:000074142500035 ER PT J AU Subramanian, MA Ramirez, AP Kwei, GH AF Subramanian, MA Ramirez, AP Kwei, GH TI Colossal magnetoresistance behavior in manganese oxides: pyrochlore versus perovskite SO SOLID STATE IONICS LA English DT Article; Proceedings Paper CT IUMRS-ICA Symposium R on Perovskite-Related Oxides - Preparation, Properties and Perspectives CY SEP 16-17, 1997 CL CHIBA, JAPAN SP Int Union Mat Res Soc DE colossal magnetoresistance; ferromagnetism; perovskite; pyrochlore; manganese oxides ID MN3+/MN4+ DOUBLE EXCHANGE; NEUTRON-SCATTERING; TL2MN2O7; Y2MN2O7; LA1-XCAXMNO3; RESISTIVITY; FILMS; ORDER AB Manganese oxides exhibiting colossal magnetoresistance (CMR) fall broadly into two structural categories: the substituted rare-earth manganite perovskites (Ln(1-x)D(x)MnO(3)) and the thallium manganite pyrochlore (Tl2Mn2O7). The driving forces for the CMR transition in perovskites are thought to be the double-exchange interaction resulting from Mn3+/Mn4+ mixed valency as well as polaronic effects resulting from strong electron-phonon coupling due to the presence of Jahn-Teller ion, Mn3+. On the other hand, structural determination from neutron and single-crystal X-ray diffraction data as well as X-ray absorption spectroscopic analysis of Tl2Mn2O7 pyrochlore show no deviations from ideal stoichiometry, Mn3+/Mn4+ mixed valency or Jahn-Teller distortions of the MnO6 octahedron indicating that the driving force for the CMR here is fundamentally different from perovskites. We review the similarities and the differences in structural and electronic properties exhibited by these two families, and discuss the implications of these observations to our understanding of the mechanism of CMR in these materials. (C) 1998 Elsevier Science B.V. All rights reserved. C1 Dupont Co, Cent Res & Dev, Expt Stn, Wilmington, DE 19880 USA. AT&T Bell Labs, Lucent Technol, Murray Hill, NJ 07974 USA. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Subramanian, MA (reprint author), Dupont Co, Cent Res & Dev, Expt Stn, Wilmington, DE 19880 USA. EM subra@esvax.dnet.dupont.com NR 32 TC 19 Z9 19 U1 3 U2 10 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 MAY PY 1998 VL 108 IS 1-4 BP 185 EP 191 DI 10.1016/S0167-2738(98)00038-1 PG 7 WC Chemistry, Physical; Physics, Condensed Matter SC Chemistry; Physics GA ZP809 UT WOS:000073790600029 ER PT J AU Balachandran, U Ma, B Maiya, PS Mieville, RL Dusek, JT Picciolo, JJ Guan, J Dorris, SE Liu, M AF Balachandran, U Ma, B Maiya, PS Mieville, RL Dusek, JT Picciolo, JJ Guan, J Dorris, SE Liu, M TI Development of mixed-conducting oxides for gas separation SO SOLID STATE IONICS LA English DT Article; Proceedings Paper CT IUMRS-ICA Symposium R on Perovskite-Related Oxides - Preparation, Properties and Perspectives CY SEP 16-17, 1997 CL CHIBA, JAPAN SP Int Union Mat Res Soc DE mixed-conductor; gas separation; oxygen permeation; proton conduction; ceramic membrane ID OXYGEN PERMEATION; SYSTEM AB Mixed-conducting oxides have been used in many applications, including fuel cells, gas-separation membranes, sensors, and electrocatalysis. We are developing a mixed-conducting, dense ceramic membrane for selectively transporting oxygen and hydrogen. Ceramic membranes made of Sr-Fe-Co oxide, which has high combined electronic and oxygen ionic conductions, can be used to selectively transport oxygen during the partial oxidation of methane to synthesis gas (syngas, CO + H-2). We have measured the steady-state oxygen permeability of SrFeCo0.5Ox as a function of oxygen partial-pressure gradient and temperature. At 900 degrees C, oxygen permeability was approximate to 2.5 sec cm(-2) min(-1) for a 2.9 mm thick membrane and this value increases as membrane thickness decreases. We have fabricated tubular SrFeCo0.5Ox membranes and operated them at 900 degrees C for > 1000 h during conversion of methane into syngas. The hydrogen ion (proton) transport properties of Ba(Ce,Y)O3-delta were investigated by impedance spectroscopy and open-cell voltage measurements. High proton conductivity and a high protonic transference number make Ba(Ce,Y)O3-delta a potential membrane for hydrogen separation. Published by Elsevier Science B.V. C1 Argonne Natl Lab, Div Energy Technol, Argonne, IL 60439 USA. Georgia Inst Technol, Sch Mat Sci & Engn, Atlanta, GA 30332 USA. RP Balachandran, U (reprint author), Argonne Natl Lab, Div Energy Technol, 9700 S Cass Ave, Argonne, IL 60439 USA. EM u_balachandran@qmgate.anl.gov RI Liu, Meilin/E-5782-2010; Ma, Beihai/I-1674-2013 OI Liu, Meilin/0000-0002-6188-2372; Ma, Beihai/0000-0003-3557-2773 NR 24 TC 87 Z9 92 U1 1 U2 21 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 MAY PY 1998 VL 108 IS 1-4 BP 363 EP 370 DI 10.1016/S0167-2738(98)00064-2 PG 8 WC Chemistry, Physical; Physics, Condensed Matter SC Chemistry; Physics GA ZP809 UT WOS:000073790600055 ER PT J AU Gurley, LR Jandacek, AL Valdez, JG Sebring, RJ D'Anna, JA Puck, TT AF Gurley, LR Jandacek, AL Valdez, JG Sebring, RJ D'Anna, JA Puck, TT TI Br-cAMP induction of apoptosis in synchronized CHO cells SO SOMATIC CELL AND MOLECULAR GENETICS LA English DT Article ID CHINESE-HAMSTER CELLS; HISTONE PHOSPHORYLATION; CYCLIC-AMP; DNA; TRANSFORMATION; PROLIFERATION; CYTOSKELETON; MITOSIS; CANCER AB The proliferation of suspension cultures of malignant CHO cells was inhibited by 0.5 mM Br-cAMP treatment and restored by its removal. This treatment also inhibited histone HI phosphorylation completely reduced histones H2A and H4 phosphorylations, induced DNA degradation and produced cells containing micronuclei. Agarose gel electrophoresis of the degraded DNA fragments produced a "ladder" pattern confirming these cells were undergoing apoptosis. Cell cycle synchrony experiments demonstrated culture growth inhibition was the result of two different cell cycle-specific processes: [1] arrested cell cycle travel-se at a restriction point in mid-G1, and [2] rapid apoptosis following cell division. Br-cAMP did not stop cells in late-G1, S, G2, or M from traversing the cell cycle and dividing, but. rather, induced apoptosis following mitosis. The restriction point of Br-cAMP arrest was located in the middle of a wider band of G1 arrest induced by isoleucine deprivation. The cells synchronized in G1 before the restriction point were held in G1-arrest by Br-cAMP and spared apoptotic death. These studies support the further study of cAMP derivatives as agents to induce tumor regression by apoptosis and reverse transformation. C1 Univ Calif Los Alamos Natl Lab, Div Life Sci, Los Alamos, NM 87545 USA. Univ Colorado, Hlth Sci Ctr, Dept Med, Denver, CO 80206 USA. Univ Colorado, Hlth Sci Ctr, Ctr Canc, Denver, CO 80206 USA. Eleanor Roosevelt Inst Canc Res, Denver, CO 80206 USA. RP Gurley, LR (reprint author), Univ Calif Los Alamos Natl Lab, Div Life Sci, Los Alamos, NM 87545 USA. NR 30 TC 7 Z9 8 U1 0 U2 0 PU KLUWER ACADEMIC/PLENUM PUBL PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 0740-7750 J9 SOMAT CELL MOLEC GEN JI Somat.Cell Mol.Genet. PD MAY PY 1998 VL 24 IS 3 BP 173 EP 190 DI 10.1023/B:SCAM.0000007120.17128.e0 PG 18 WC Biochemistry & Molecular Biology; Cell Biology; Genetics & Heredity SC Biochemistry & Molecular Biology; Cell Biology; Genetics & Heredity GA 188FJ UT WOS:000079835900004 PM 10226655 ER PT J AU Robertson, EP AF Robertson, EP TI The use of bacteria to reduce water influx in producing oil wells SO SPE PRODUCTION & FACILITIES LA English DT Article; Proceedings Paper CT 1996 SPE Eastern Regional Meeting CY OCT 23-25, 1996 CL COLUMBUS, OHIO SP Soc Petr Engineers AB This paper reports the results of a laboratory investigation evaluating the use of bacteria to reduce water production from oil wells. The objectives are to show that bacteria can be used to form in-depth stable plugs in porous media, to show that the bacterial plug can reduce effectively the amount of water being produced in oil wells by preferentially reducing the relative permeability of water, and to report briefly on the economic value of such a treatment. Bacterial strains for tests in a physical model of a producing well and near-wellbore region with flow in two dimensions were selected based on results in linear-flow sandpacks. Results from the linear sandpacks showed that in-depth plugs can be formed in porous media by the injection of one pore volume of nutrient. The pretreatment sandpack permeability of 6,600 md was reduced to a stable 200 md after one treatment. Bacterial injection and incubation in the two-dimensional physical model resulted in a 47% decrease in water cut (from 95% pretreatment to 50% post-treatment). The experiments also show that the bacterial plug preferentially reduces the relative permeability of water in the presence of both oil and water. A preliminary economic evaluation was performed using field data and laboratory results. Although no attempt was made to economically optimize the laboratory system, an extrapolation to field values shows economic potential. C1 US DOE, Idaho Natl Engn & Environm Lab, Lockheed Martin Idaho Technol Co, Microbial Enhanced Oil Recovery Res Program, Idaho Falls, ID 83401 USA. RP Robertson, EP (reprint author), US DOE, Idaho Natl Engn & Environm Lab, Lockheed Martin Idaho Technol Co, Microbial Enhanced Oil Recovery Res Program, Idaho Falls, ID 83401 USA. NR 14 TC 1 Z9 1 U1 0 U2 0 PU SOC PETROLEUM ENG PI RICHARDSON PA 222 PALISADES CREEK DR,, RICHARDSON, TX 75080 USA SN 1064-668X J9 SPE PROD FACIL JI SPE Prod. Fac. PD MAY PY 1998 VL 13 IS 2 BP 128 EP 132 PG 5 WC Engineering, Petroleum SC Engineering GA ZR340 UT WOS:000073964300008 ER PT J AU Tirumala, SP Lee, DF Kroeger, DM Salama, K AF Tirumala, SP Lee, DF Kroeger, DM Salama, K TI Effects of stoichiometric variation and cooling rate on the phase formation and critical current density of Bi-2223 powder-in-tube tapes made from aerosol precursor SO SUPERCONDUCTOR SCIENCE & TECHNOLOGY LA English DT Article ID SHEATHED TAPES; 110-K PHASE; MICROSTRUCTURE; SYSTEM; BI; DIAGRAM; (BI AB Powder-in-tube Bi-2223 is currently the most promising high-temperature superconductor that can be fabricated in long lengths by industrial processes, and is likely to be used as the conductor component in first-generation applications. Intensive investigations of these conductors have revealed that the critical current density of fully processed tapes is influenced by a large number of processing parameters. Among these are the thermomechanical processing schedule and the extent of Bi-2223 phase conversion. These parameters are, in turn, affected by the precursor stoichiometry. In this study, powder precursors with varying Cu content were prepared using an aerosol pyrolysis technique, and powder-in-tube conductors were fabricated using these precursors. Both fast and slow cooling rates were employed during thermomechanical processing, and different treatment schedules are correlated to the critical current density. The results indicate that the effect of excess Cu on J(c) is minor compared to the large J(c) enhancements obtained by employing one or more slow-cooling steps in the thermomechanical processing schedule. C1 Univ Houston, Texas Ctr Superconduct, Houston, TX 77004 USA. Oak Ridge Natl Lab, Div Met & Ceram, Oak Ridge, TN USA. RP Tirumala, SP (reprint author), Univ Houston, Texas Ctr Superconduct, Houston, TX 77004 USA. NR 27 TC 6 Z9 6 U1 0 U2 0 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0953-2048 J9 SUPERCOND SCI TECH JI Supercond. Sci. Technol. PD MAY PY 1998 VL 11 IS 5 BP 496 EP 504 DI 10.1088/0953-2048/11/5/009 PG 9 WC Physics, Applied; Physics, Condensed Matter SC Physics GA ZP371 UT WOS:000073745600009 ER PT J AU Follstaedt, DM Myers, SM Knapp, JA Dugger, MT Christenson, TA AF Follstaedt, DM Myers, SM Knapp, JA Dugger, MT Christenson, TA TI Microstructure of bulk and electroformed Ni implanted with Ti and C SO SURFACE & COATINGS TECHNOLOGY LA English DT Article; Proceedings Paper CT 10th International Conference on Surface Modification of Metals by Ion Beams (SMMIB 97) CY SEP 21-26, 1997 CL GATLINBURG, TENNESSEE SP Oak Ridge Natl Lab, Danfysik, Implant Sci Corp, Spire Corp DE amorphous phase; electroformed Ni alloys; micro-electromechanical systems (MEMS); Ni-Ti-C ID FE AB The microstructure of high-purity Ni implanted with overlapping concentration profiles of Ti and C was examined with transmission electron microscopy. An amorphous phase forms at concentrations of 15-18 at.% Ti and 22 at.% C, while a two-phase alloy (amorphous+f.c.c. Ni) forms for <16 at.% C. Electroformed layers with sub-micron fc.c. grains of Ni or Ni80Fe20 were also found to be amorphized by Ti+C implantation, a key requirement for applying this treatment to Ni-based microelectromechanical systems to reduce their friction and wear. (C) 1998 Elsevier Science S.A. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Follstaedt, DM (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. EM dmfolls@sandia.gov NR 19 TC 2 Z9 2 U1 0 U2 0 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0257-8972 J9 SURF COAT TECH JI Surf. Coat. Technol. PD MAY PY 1998 VL 104 BP 40 EP 45 DI 10.1016/S0257-8972(98)00372-7 PG 6 WC Materials Science, Coatings & Films; Physics, Applied SC Materials Science; Physics GA ZZ476 UT WOS:000074733200009 ER PT J AU Liu, F Dickinson, MR MacGill, RA Anders, A Monteiro, OR Brown, IG Phillips, L Biallas, G Siggins, T AF Liu, F Dickinson, MR MacGill, RA Anders, A Monteiro, OR Brown, IG Phillips, L Biallas, G Siggins, T TI Surface resistivity tailoring of ceramics by metal ion implantation SO SURFACE & COATINGS TECHNOLOGY LA English DT Article; Proceedings Paper CT 10th International Conference on Surface Modification of Metals by Ion Beams (SMMIB 97) CY SEP 21-26, 1997 CL GATLINBURG, TENNESSEE SP Oak Ridge Natl Lab, Danfysik, Implant Sci Corp, Spire Corp DE ceramics; metal ion implantation; surface resistivity ID VACUUM AB An important technique used for the suppression of high-voltage surface flashover on ceramic insulators as well as for RF windows is to provide some surface conduction to bleed off the accumulated surface charge. We have used metal ion implantation to modify the surface of high-voltage ceramic vacuum insulators so as to provide a uniform surface resistivity of the order of 10(10) Omega square(-1). A broad-beam vacuum are ion source-based implanter was used to implant Pt at about 130 keV to doses of up to similar to 6 x 10(16) ions cm(-2) into both small ceramic test coupons and also into the inside surface of several ceramic accelerator columns 25 cm I.D. by 28 cm long. For implantation of the large columns, an appendage to the implanter was made that allowed the column to be continuously rotated while being implanted. A rotating cradle held the column at an appropriate angle to the incident energetic large-area ion beam while continuously slowly rotating it about its axis so that the entire inside surface was uniformly implanted. The mechanism was insulated, and the high-voltage resistance could be measured in-situ (with implantation switched off) at selected times during the processing. By appropriate choice of dose, the surface resistivity could be tailored over a range from its pre-implantation value of > 10(15) Omega square(-1) down to similar to 10(9) Omega square(-1). The results indicate that even lower resistivity values can be achieved if desired. Here, we describe the experimental set-up used to do the ion implantation and summarize the results of our work on implantation into test coupons and ceramic columns. (C) 1998 Elsevier Science S.A. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. Thomas Jefferson Natl Accelerator Facil, Newport News, VA USA. RP Brown, IG (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RI Anders, Andre/B-8580-2009 OI Anders, Andre/0000-0002-5313-6505 NR 13 TC 11 Z9 13 U1 0 U2 0 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0257-8972 J9 SURF COAT TECH JI Surf. Coat. Technol. PD MAY PY 1998 VL 104 BP 46 EP 51 DI 10.1016/S0257-8972(98)00373-9 PG 6 WC Materials Science, Coatings & Films; Physics, Applied SC Materials Science; Physics GA ZZ476 UT WOS:000074733200010 ER PT J AU Walter, KC Nastasi, M Baker, NP Munson, CP Scarborough, WK Scheuer, JT Wood, BP Conrad, JR Sridharan, K Malik, S Bruen, RA AF Walter, KC Nastasi, M Baker, NP Munson, CP Scarborough, WK Scheuer, JT Wood, BP Conrad, JR Sridharan, K Malik, S Bruen, RA TI Advances in PSII techniques for surface modification SO SURFACE & COATINGS TECHNOLOGY LA English DT Article; Proceedings Paper CT 10th International Conference on Surface Modification of Metals by Ion Beams (SMMIB 97) CY SEP 21-26, 1997 CL GATLINBURG, TN SP Oak Ridge Natl Lab, Danfysik, Implant Sci Corp, Spire Corp DE plasma source ion implantation; wear; friction; surface modification ID SOURCE ION-IMPLANTATION; PLASMA DEPOSITION AB Recent activities in plasma source ion implantation (PSII) technology include scale-up demonstrations for industry and development of variations on the original PSII concept for surface modification. This paper presents an overview of the continued growth of PSII research facilities world-wide and the industrial demonstrations within the USA. In order to expand the applicability of PSII, Los Alamos is actively researching a PSII-related technique called plasma immersion ion processing (PIIP). In one case, a pulsed-biased target can be combined with cathodic are sources to perform ion implantation and coating deposition with metal plasmas. Erbium plasmas have been combined with oxygen to deposit erbia (Er(2)O(3)) coatings that are useful for containment of molten metals. In a second case, hydrocarbon, inorganic and organometallic gases are utilized to create a graded interface between the substrate and the coating that is subsequently deposited by using pulsed-bias techniques. PIIP represents a significant advance since it allows coating deposition with all the strengths of the original PSII approach. Diamond-like carbon (DLC) and boron carbide are two such coatings that will be highlighted here for tribological applications. (C) 1998 Elsevier Science S.A. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Univ Wisconsin, Madison, WI 53706 USA. RP Walter, KC (reprint author), Los Alamos Natl Lab, MS-K762, Los Alamos, NM 87545 USA. NR 16 TC 32 Z9 38 U1 1 U2 3 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0257-8972 J9 SURF COAT TECH JI Surf. Coat. Technol. PD MAY PY 1998 VL 104 BP 205 EP 211 DI 10.1016/S0257-8972(98)00394-6 PG 7 WC Materials Science, Coatings & Films; Physics, Applied SC Materials Science; Physics GA ZZ476 UT WOS:000074733200039 ER PT J AU Knapp, JA Follstaedt, DM Myers, SM Barbour, JC Friedmann, TA Ager, JW Monteiro, OR Brown, IG AF Knapp, JA Follstaedt, DM Myers, SM Barbour, JC Friedmann, TA Ager, JW Monteiro, OR Brown, IG TI Finite-element modeling of nanoindentation for evaluating mechanical properties of MEMS materials SO SURFACE & COATINGS TECHNOLOGY LA English DT Article; Proceedings Paper CT 10th International Conference on Surface Modification of Metals by Ion Beams (SMMIB 97) CY SEP 21-26, 1997 CL GATLINBURG, TENNESSEE SP Oak Ridge Natl Lab, Danfysik, Implant Sci Corp, Spire Corp DE modeling; mechanical properties; MEM; nanoindentation ID PULSED-LASER DEPOSITION; ELASTIC-MODULUS; INDENTATION AB We have developed procedures based on finite-element modeling of nanoindentation data to extract mechanical properties from thin, hard films and ion-beam-modified layers on softer substrates. The method accurately deduces the yield stress, Young's modulus. and hardness from indentations as deep as 50% of the layer thickness. We use these procedures to evaluate two hard layers potentially useful for reducing friction and wear of components in micro-electromechanical systems (MEMS): Ni implanted with Ti and C, and diamond-like carbon layers. We show that the modeling works well even for materials whose hardness approaches that of diamond, a case where commonly used analytical methods for deducing the modulus fail. (C) 1998 Elsevier Science S.A. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Knapp, JA (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. OI Ager, Joel/0000-0001-9334-9751 NR 16 TC 36 Z9 38 U1 0 U2 2 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0257-8972 J9 SURF COAT TECH JI Surf. Coat. Technol. PD MAY PY 1998 VL 104 BP 268 EP 275 DI 10.1016/S0257-8972(98)00422-8 PG 8 WC Materials Science, Coatings & Films; Physics, Applied SC Materials Science; Physics GA ZZ476 UT WOS:000074733200051 ER PT J AU Myers, SM Knapp, JA Follstaedt, DM Dugger, MT Christenson, TR AF Myers, SM Knapp, JA Follstaedt, DM Dugger, MT Christenson, TR TI Strength and tribology of bulk and electroformed nickel amorphized by implantation of titanium and carbon SO SURFACE & COATINGS TECHNOLOGY LA English DT Article; Proceedings Paper CT 10th International Conference on Surface Modification of Metals by Ion Beams (SMMIB 97) CY SEP 21-26, 1997 CL GATLINBURG, TENNESSEE SP Oak Ridge Natl Lab, Danfysik, Implant Sci Corp, Spire Corp DE ion implantation; mechanical properties; micro-electromechanical systems; nickel ID SURFACE MECHANICAL-PROPERTIES; ION-IMPLANTATION; TI; FE; MICROMECHANICS; MICROSTRUCTURE; FRICTION; WEAR; NI AB Dual ion implantation of titanium and carbon was shown to produce an amorphous layer of exceptional strength within annealed bulk Ni and also within electroformed Ni and Ni,,Fe,, materials used in micro-electromechanical systems. The intrinsic elastic and plastic mechanical properties of the implanted region were quantified using nanoindentation testing in conjunction with finite-element modeling, and the results were interpreted in the light of microstructures observed by transmission electron microscopy. The implantation treatment was found to produce substantial reductions in unlubricated friction and wear. (C) 1998 Elsevier Science S.A. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Myers, SM (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. NR 24 TC 10 Z9 10 U1 0 U2 0 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0257-8972 J9 SURF COAT TECH JI Surf. Coat. Technol. PD MAY PY 1998 VL 104 BP 287 EP 292 DI 10.1016/S0257-8972(98)00425-3 PG 6 WC Materials Science, Coatings & Films; Physics, Applied SC Materials Science; Physics GA ZZ476 UT WOS:000074733200054 ER PT J AU Brown, IG Liu, F Monteiro, OR Yu, KM Evans, PJ Dytlewski, N Oztarhan, A Corcoran, SG Crowson, D AF Brown, IG Liu, F Monteiro, OR Yu, KM Evans, PJ Dytlewski, N Oztarhan, A Corcoran, SG Crowson, D TI Synthesis of sub-surface oxide layers by hybrid metal-gas co-implantation into metals SO SURFACE & COATINGS TECHNOLOGY LA English DT Article; Proceedings Paper CT 10th International Conference on Surface Modification of Metals by Ion Beams (SMMIB 97) CY SEP 21-26, 1997 CL GATLINBURG, TENNESSEE SP Oak Ridge Natl Lab, Danfysik, Implant Sci Corp, Spire Corp DE buried layers; ion implantation; metal ion implantation; tribology ID ION SOURCES; VACUUM-ARC; BEAM AB Sub-surface oxide layers can be synthesized by implantation of mixed metal-gas ion beams formed by a modified vacuum are ion source. The particle current fractions of the metal and gas ion components in the beam can be controlled from 100% metallic up to approximately 80% gaseous depending on the ion source operational parameters. We have carried out some exploratory investigations of surfaces modified by co-implantation in this way, particularly of stainless steel ion implanted with Al + O and (separately) Zr + O. Due to the ubiquitous surface layer of native oxide present on the steel substrate, additional oxygen can be recoil-implanted, and the resultant implantation can be different from that expected-the effect of the energetic oxygen ion beam is clouded by the recoil implanted oxygen. To help elucidate this complicated scenario, we have carried out a number of metal-gas co-implantation experiments in various kinds of materials. Here, we briefly describe the ion source modifications and the co-implantation process, and report on the state of our understanding of the overall sub-surface layer structure and the tribological benefits of this kind of surface modification. (C) 1998 Elsevier Science S.A. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. Australian Nucl Sci & Technol Org, Lucas Hts, NSW 2234, Australia. Dokuz Eylul Univ, TR-35100 Izmir, Turkey. Hysitron Inc, Minneapolis, MN 55413 USA. RP Brown, IG (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. EM ibrown@lbl.gov RI Yu, Kin Man/J-1399-2012 OI Yu, Kin Man/0000-0003-1350-9642 NR 20 TC 8 Z9 8 U1 0 U2 0 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0257-8972 J9 SURF COAT TECH JI Surf. Coat. Technol. PD MAY PY 1998 VL 104 BP 293 EP 298 DI 10.1016/S0257-8972(98)00426-5 PG 6 WC Materials Science, Coatings & Films; Physics, Applied SC Materials Science; Physics GA ZZ476 UT WOS:000074733200055 ER PT J AU Sood, DK Mukherjee, S Katselis, G Brown, IG Prince, KE Short, KT Evans, PJ AF Sood, DK Mukherjee, S Katselis, G Brown, IG Prince, KE Short, KT Evans, PJ TI Modification of high-temperature oxidation of titanium diboride films by implantation with tantalum and titanium ions SO SURFACE & COATINGS TECHNOLOGY LA English DT Article; Proceedings Paper CT 10th International Conference on Surface Modification of Metals by Ion Beams (SMMIB 97) CY SEP 21-26, 1997 CL GATLINBURG, TENNESSEE SP Oak Ridge Natl Lab, Danfysik, Implant Sci Corp, Spire Corp DE high-temperature oxidation; ion implantation; stainless steel 430; titanium diboride films ID TIB2 AB Titanium diboride is an attractive material for protective coatings because of its high hardness, high electrical and thermal conductivities. However, many of its high-temperature applications are limited because of its poor oxidation behaviour beyond 700 degrees C. This paper presents a novel approach consisting of doping with implantation of higher valency atoms, to improve its oxidation resistance up to 900 degrees C. TiB2 films (nominal thickness 0.5 mu m) were deposited on polished substrates of stainless steel and alumina using a RF sputtering deposition system. Alumina was chosen as an inert substrate that is more "RBS friendly". Ions of Ta (as a higher valence dopant species) or Ti (to study self ion damage effects) were implanted using a MEVVA ion implanter at an extraction voltage of 65 kV corresponding to an average energy of 190 keV for Ta and 140 keV for Ti ions. Ion doses of 1 x 10(15) to 1 x 10(17) ions cm(-2) (corresponding to dopant concentrations of about 0.1-10 at.%) were implanted at nominal RT. After implantation, some samples were vacuum-annealed (30 min at 900 degrees C, at 1 x 10(-5) Torr) to crystallise the films and/or reduce the ion damage. Oxidation of the implanted samples was conducted at 800 and 900 degrees C for 1-4 h in air. Analysis was performed by using RES, SIMS, XRD and SEM techniques. The results show: (1) as-deposited films undergo rapid corrosion and spalling on oxidation; (2) as-implanted films show little improvement and undergo rapid corrosion and spalling on oxidation; (3) when implanted films are first vacuum-annealed and then oxidised, they show an improvement in corrosion resistance and do not undergo any spalling. Ta is thus an effective dopant for improving the oxidation resistance of TiB2 films. (C) 1998 Elsevier Science S.A. C1 Royal Melbourne Inst Technol, Dept Commun & Elect Engn, Melbourne, Vic 3000, Australia. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. Australian Nucl Sci & Technol Org, Lucas Hts Res Lab, Menai, NSW 2234, Australia. RP Sood, DK (reprint author), Royal Melbourne Inst Technol, Dept Commun & Elect Engn, 124 La Trobe St, Melbourne, Vic 3000, Australia. NR 6 TC 16 Z9 17 U1 0 U2 5 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0257-8972 J9 SURF COAT TECH JI Surf. Coat. Technol. PD MAY PY 1998 VL 104 BP 304 EP 311 DI 10.1016/S0257-8972(98)00428-9 PG 8 WC Materials Science, Coatings & Films; Physics, Applied SC Materials Science; Physics GA ZZ476 UT WOS:000074733200057 ER PT J AU Hamdi, AH Qiu, X Malaczynski, GW Elmoursi, AA Simko, S Militello, MC Balogh, MP Wood, BP Walter, KC Nastasi, MA AF Hamdi, AH Qiu, X Malaczynski, GW Elmoursi, AA Simko, S Militello, MC Balogh, MP Wood, BP Walter, KC Nastasi, MA TI Microstructure analysis of plasma immersion ion implanted diamond-like carbon coatings SO SURFACE & COATINGS TECHNOLOGY LA English DT Article; Proceedings Paper CT 10th International Conference on Surface Modification of Metals by Ion Beams (SMMIB 97) CY SEP 21-26, 1997 CL GATLINBURG, TENNESSEE SP Oak Ridge Natl Lab, Danfysik, Implant Sci Corp, Spire Corp DE coatings; diamond-like carbon; ion implantation; plasma immersion ion implantation AB This paper discusses the deposition of diamond-like carbon (DLC) coatings using Plasma Immersion Ion Implantation (PIII). Microstructure analysis indicates that an adhesion layer composed of carbides is formed by CH4 implantation. Transmission electron microscopy and X-ray diffraction analysis indicates the absence of a long-range crystalline order in these carbides. It was also found that during the formation of the adhesion layer, a thin amorphous carbon layer is formed at the surface of the implanted layer. To promote the adhesion of the following DLC coating, it was found necessary to remove this amorphous carbon layer. This was accomplished by sputter-cleaning with Ar for several minutes and resulted in excellent adhesion of the DLC coatings. The formation of the amorphous carbon layer during CH4 plasma immersion ion implantation is attributed (a) to the low duty cycles used in this process (the neutral species and the residual low energy ions are deposited on the surface during the off-period between pulses), and (b) to the low energy ions (below 1 keV) generated during the rise and fall times of the high-voltage pulses. (C) 1998 Elsevier Science S.A. C1 GM Corp, Ctr Res & Dev, Elect & Elect Dept, Warren, MI 48090 USA. GM Corp, Ctr Res & Dev, Dept Analyt Chem, Warren, MI 48090 USA. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Elmoursi, AA (reprint author), GM Corp, Ctr Res & Dev, Elect & Elect Dept, Mail Code 480-106-605,30500 Mound Rd, Warren, MI 48090 USA. NR 8 TC 12 Z9 14 U1 1 U2 2 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0257-8972 J9 SURF COAT TECH JI Surf. Coat. Technol. PD MAY PY 1998 VL 104 BP 395 EP 400 DI 10.1016/S0257-8972(98)00419-8 PG 6 WC Materials Science, Coatings & Films; Physics, Applied SC Materials Science; Physics GA ZZ476 UT WOS:000074733200074 ER PT J AU Zuhr, RA Magruder, RH Anderson, TS AF Zuhr, RA Magruder, RH Anderson, TS TI Formation and optical properties of intermetallic nanoclusters formed by sequential ion implantation SO SURFACE & COATINGS TECHNOLOGY LA English DT Article; Proceedings Paper CT 10th International Conference on Surface Modification of Metals by Ion Beams (SMMIB 97) CY SEP 21-26, 1997 CL GATLINBURG, TENNESSEE SP Oak Ridge Natl Lab, Danfysik, Implant Sci Corp, Spire Corp DE ion implantation; nanocluster composites; optical materials/properties; silica/SiO2 ID FUSED-SILICA; COLLOID FORMATION; METAL COLLOIDS; GLASS; CU; AG; ABSORPTION; RESONANCE; SPECTRA AB Recent demonstrations that large third-order non-linear responses can be achieved in metal nanocluster glass composites are of significant interest because of their potential for use in all optical switching networks. These composite materials exhibit picosecond switching and relaxation times, thermal and chemical stability, high laser damage thresholds, and low two-photon absorption. Ion implantation has been shown to be a useful fabrication method to form these nanoclusters in silica because of its ability to produce thin films in waveguide configurations containing a high volume fraction (>1%) of metal colloids with well-defined vertical and horizontal dimensional control. Using sequential ion implantation of more than one element, we can modify the composition and microstructure of the composites by forming intermetallic metal colloids. In this work, we report on the improved optical response of metallic nanocluster composites formed by sequential implantation of Cd and Ag and Sb and Ag. Characterization of the samples by transmission electron microscopy (TEM) reveals that approximately spherical metallic colloids are formed for all implanted species during the implantation process. Selected area diffraction patterns indicate that the colloids formed are intermetallic in composition. Linear optical absorption measurements made at room temperature in air from 900 to 200 nm show significant changes in both the magnitude and wavelength of the surface plasmon resonance. The formation of intermetallic nanoclusters results in changes in both the linear and non-linear optical properties of the composite material that are not possible with single element colloids alone. The results are explained in terms of effective medium theory. (C) 1998 Elsevier Science S.A. C1 Oak Ridge Natl Lab, Div Solid State, Oak Ridge, TN 37831 USA. Vanderbilt Univ, Dept Appl & Engn Sci, Nashville, TN 37235 USA. RP Zuhr, RA (reprint author), Oak Ridge Natl Lab, Div Solid State, POB 2008, Oak Ridge, TN 37831 USA. EM zur@ornl.gov NR 25 TC 24 Z9 28 U1 0 U2 3 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0257-8972 J9 SURF COAT TECH JI Surf. Coat. Technol. PD MAY PY 1998 VL 104 BP 401 EP 408 DI 10.1016/S0257-8972(98)00431-9 PG 8 WC Materials Science, Coatings & Films; Physics, Applied SC Materials Science; Physics GA ZZ476 UT WOS:000074733200075 ER PT J AU Hunt, EM Hampikian, JM Poker, DB Evans, ND AF Hunt, EM Hampikian, JM Poker, DB Evans, ND TI Ion implantation induced formation of aluminum nanoparticles in alumina via reduction SO SURFACE & COATINGS TECHNOLOGY LA English DT Article; Proceedings Paper CT 10th International Conference on Surface Modification of Metals by Ion Beams (SMMIB 97) CY SEP 21-26, 1997 CL GATLINBURG, TENNESSEE SP Oak Ridge Natl Lab, Danfysik, Implant Sci Corp, Spire Corp DE alumina; aluminum; ion implantation; nanoparticles ID OPTICAL-PROPERTIES; COLLOID FORMATION; AL2O3; NANOCRYSTALS; SAPPHIRE; SILICA AB Ion implantation of calcium and yttrium into high-purity, single crystalline a-alumina has resulted in the formation of metallic aluminum nanoparticles in the implanted regions. The calcium implantations were carried out at accelerating energies of 50 and 70 keV and resulted in particles with average diameters of approximately 8.2 +/- 1.4 nm. The yttrium was implanted at an accelerating energy of 150 keV and resulted in particles of approximately 10 +/- 1.8 nm in diameter. The ion fluence for all implantations was 5 x 10(16) ions cm(-2). Differential optical absorption measurements support the presence of nanoparticles in these samples. The spectra from the Ca implanted samples show absorption features at similar to 245 nm. The spectrum from the Y implanted sample shows a similar, but more intense, absorption feature at 239 nm. The particles are face-centered cubic with a calculated lattice parameter of a(o) = 0.41 nm and are randomly oriented and aluminum-rich with respect to the surrounding amorphous alumina matrix. Energy filtering transmission electron microscopy (EFTEM) results confirm that the particles contain metallic aluminum, which is formed as a result of the reduction of the alumina matrix. (C) 1998 Elsevier Science S.A. C1 Georgia Inst Technol, Sch Mat Sci & Engn, Atlanta, GA 30332 USA. Oak Ridge Natl Lab, Div Solid State, Oak Ridge, TN 37831 USA. Oak Ridge Inst Sci & Educ, Oak Ridge, TN 37831 USA. RP Hampikian, JM (reprint author), Georgia Inst Technol, Sch Mat Sci & Engn, 778 Atlantic Dr, Atlanta, GA 30332 USA. RI Evans, Neal/F-5955-2011; OI Callahan, Janet /0000-0001-6665-1584 NR 29 TC 5 Z9 5 U1 1 U2 5 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0257-8972 J9 SURF COAT TECH JI Surf. Coat. Technol. PD MAY PY 1998 VL 104 BP 409 EP 414 DI 10.1016/S0257-8972(98)00432-0 PG 6 WC Materials Science, Coatings & Films; Physics, Applied SC Materials Science; Physics GA ZZ476 UT WOS:000074733200076 ER PT J AU Rhykerd, C AF Rhykerd, C TI Explosives sniffing - Response SO TECHNOLOGY REVIEW LA English DT Letter C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Rhykerd, C (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU MASS INST TECHNOL PI CAMBRIDGE PA BUILDING W59, CAMBRIDGE, MA 02139 USA SN 0040-1692 J9 TECHNOL REV JI Technol. Rev. PD MAY-JUN PY 1998 VL 101 IS 3 BP 17 EP 17 PG 1 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA ZJ906 UT WOS:000073265600018 ER PT J AU Tschaplinski, TJ Gebre, GM Shirshac, TL AF Tschaplinski, TJ Gebre, GM Shirshac, TL TI Osmotic potential of several hardwood species as affected by manipulation of throughfall precipitation in an upland oak forest during a dry year SO TREE PHYSIOLOGY LA English DT Article DE Acer rubrum; Acer saccharum; American beech; chestnut oak; Cornus florida; dehydration tolerance; dogwood; Fagus grandifolia; leaf water potential; osmotic adjustment; Quercus alb; Quercus prinus; red maple; sugar maple; white oak ID TISSUE WATER RELATIONS; QUERCUS-ALBA; DROUGHT; STRESS; RESPONSES; SEEDLINGS; SEASON; TIME; LEAF AB Components of dehydration tolerance, including osmotic potential at full turgor (Psi(pi o)) and osmotic adjustment (lowering of (Psi(pi o)), of several deciduous species were investigated in a mature, upland oak forest in eastern Tennessee. Beginning July 1993, the trees were subjected to one of three throughfall precipitation treatments: ambient, ambient minus 33% (dry treatment), and ambient plus 33% (wet treatment). During the dry 1995 growing season, leaf water potentials of all species declined to between -2.5 and -3.1 MPa in the dry treatment. There was considerable variation in Psi(pi o) among species (-1.0 to -2.0 MPa). Based on Psi(pi o) values, American beech (Fagus grandifolia Ehrh,), dogwood (Cornus florida L.), and sugar maple (Acer saccharum Marsh.) were least dehydration tolerant, red maple (A. rubrum L.) was intermediate in tolerance, and white oak (Quercus alba L.) and chestnut oak (Quercus prinus L.) were most tolerant. During severe drought, overstory chestnut oak and understory dogwood, red maple and chestnut oak displayed osmotic adjustment (-0.12 to -0.20 MPa) in the dry treatment relative to the wet treatment. (No osmotic adjustment was evident in understory red maple and chestnut oak during the previous wet year.) Osmotic potential at full turgor was generally correlated with leaf water potential, with both declining over the growing season, especially in species that displayed osmotic adjustment. However, osmotic adjustment was not restricted to species considered dehydration tolerant; for example, dogwood typically maintained high Psi(pi o) and displayed osmotic adjustment to drought, but had the highest mortality rates of the species studied. Understory saplings tended to have higher Psi(pi o) than overstory trees when water availability was high, but Psi(pi o) of understory trees declined to values observed for overstory trees during severe drought. We conclude that Psi(pi o) varies among deciduous hardwood species and is dependent on canopy position and soil water potential in the rooting zone. C1 Oak Ridge Natl Lab, Div Environm Sci, Oak Ridge, TN 37831 USA. Univ Minnesota, Water Resources Ctr, St Paul, MN 55108 USA. RP Tschaplinski, TJ (reprint author), Oak Ridge Natl Lab, Div Environm Sci, POB 2008, Oak Ridge, TN 37831 USA. OI Tschaplinski, Timothy/0000-0002-9540-6622 NR 30 TC 44 Z9 46 U1 2 U2 15 PU HERON PUBLISHING PI VICTORIA PA 202, 3994 SHELBOURNE ST, VICTORIA, BC V8N 3E2, CANADA SN 0829-318X J9 TREE PHYSIOL JI Tree Physiol. PD MAY PY 1998 VL 18 IS 5 BP 291 EP 298 PG 8 WC Forestry SC Forestry GA ZM766 UT WOS:000073573700002 ER PT J AU Gebre, GM Tschaplinski, TJ Shirshac, TL AF Gebre, GM Tschaplinski, TJ Shirshac, TL TI Water relations of several hardwood species in response to throughfall manipulation in an upland oak forest during a wet year SO TREE PHYSIOLOGY LA English DT Article DE Acer rubrum; Acer saccharum; blackgum; chestnut oak; Cornus florida; dogwood; drought tolerance; Nyssa sylvatica; oak; osmotic adjustment; osmotic potential; Quercus alba; Quercus prinus; red maple; sugar maple; white oak ID DROUGHT; LEAF; PENNSYLVANIA; TOLERANCE; POPULUS; ACER AB We investigated the effects of altered precipitation on leaf osmotic potential at full turgor (Psi(pi o)) of several species in an upland oak forest during the 1994 growing season as part of a Throughfall Displacement Experiment at the Walker Branch Watershed near Oak Ridge, Tennessee. The main species sampled included overstory chestnut oak (Quercus prinus L.), white oak (Q. alba L.), red maple (Acer rubrum L.); intermediates sugar maple (A. saccharum L,) and blackgum (Nyssa sylvatica Marsh,); and understory dogwood (Cornus florida L.) and red maple. The precipitation treatments were: ambient precipitation; ambient minus 33% of throughfall (dry); and ambient plus 33% of throughfall (wet), Except in late September, midday leaf water potentials (Psi(1)) were generally high in all species in all treatments, ranging from-031 to -1.34 MPa for C. florida, -0.58 to -1.51 MPa for A. rubrum, and -0.78 to -1.86 MPa for e. prinus. Both treatment and species differences in Psi(pi o) were evident, with oak species generally exhibiting lower Psi(pi o) than A. saccharum, A. rubrum, C. florida, and N. sylvatica. The Psi(pi o) of C. florida saplings declined in the dry treatment, and Q. prinus, Q. alba, and A. saccharum all exhibited a declining trend of Psi(pi o) in the dry treatment, although Psi(pi o) of Q. prinus leaves increased in late August, corresponding to a recovery in soil water potential. Cornus florida exhibited osmotic adjustment with the largest adjustment coinciding with the period of lowest soil water potential in June. The only other species to exhibit osmotic adjustment was e. prinus, which also maintained a lower baseline Psi(pi o) than the other species. We conclude that a 33% reduction of throughfall is sufficient both to alter the water relations of some species in the upland oak forest and to enable the identification of those species capable of osmotic adjustment to a short-term drought during a wet year. C1 Oak Ridge Natl Lab, Div Environm Sci, Oak Ridge, TN 37831 USA. Univ Minnesota, Water Resources Ctr, St Paul, MN 55108 USA. RP Gebre, GM (reprint author), Oak Ridge Natl Lab, Div Environm Sci, POB 2008, Oak Ridge, TN 37831 USA. OI Tschaplinski, Timothy/0000-0002-9540-6622 NR 27 TC 27 Z9 28 U1 1 U2 8 PU HERON PUBLISHING PI VICTORIA PA 202, 3994 SHELBOURNE ST, VICTORIA, BC V8N 3E2, CANADA SN 0829-318X J9 TREE PHYSIOL JI Tree Physiol. PD MAY PY 1998 VL 18 IS 5 BP 299 EP 305 PG 7 WC Forestry SC Forestry GA ZM766 UT WOS:000073573700003 ER PT J AU Carpick, RW Dai, Q Ogletree, DF Salmeron, M AF Carpick, RW Dai, Q Ogletree, DF Salmeron, M TI Friction force microscopy investigations of potassium halide surfaces in ultrahigh vacuum: structure, friction and surface modification SO TRIBOLOGY LETTERS LA English DT Article DE force microscopy; alkali halide; KCl; KBr; KF; friction; wear; surface structure; nanotribology ID IONIC SURFACES; ATOMIC-SCALE; CALIBRATION; ADHESION; CONTACT; SOLIDS; MODEL; AGBR AB Friction force microscopy measurements on the vacuum-cleaved (001) surfaces of RF, KCl and KBr have been carried out. All surfaces exhibit atomically flat terraces with monatomic steps aligned preferentially along low-index lattice directions. Stick-slip lateral forces with the lattice periodicity are observed on all surfaces. Tip-sample contact creates higher friction domains on the terraces of all three materials. The structure, topography and degree of friction force contrast of these domains is material dependent. The dependence of friction upon load generally does not coincide with the behavior expected for an elastic contact. We propose that the observed domains result from surface structural changes created by low load tip-sample contact on these relatively soft materials. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. RP Salmeron, M (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. RI Ogletree, D Frank/D-9833-2016 OI Ogletree, D Frank/0000-0002-8159-0182 NR 33 TC 22 Z9 22 U1 0 U2 3 PU BALTZER SCI PUBL BV PI BUSSUM PA PO BOX 221, 1400 AE BUSSUM, NETHERLANDS SN 1023-8883 J9 TRIBOL LETT JI Tribol. Lett. PD MAY PY 1998 VL 5 IS 1 BP 91 EP 102 DI 10.1023/A:1019112901870 PG 12 WC Engineering, Chemical; Engineering, Mechanical SC Engineering GA 115WJ UT WOS:000075689100011 ER PT J AU Gracias, DH Zhang, D Shen, YR Somorjai, GA AF Gracias, D. H. Zhang, D. Shen, Y. R. Somorjai, G. A. TI Surface chemistry-mechanical property relationship of low density polyethylene: an IR plus visible sum frequency generation spectroscopy and atomic force microscopy study SO TRIBOLOGY LETTERS LA English DT Article DE sum frequency generation (SFG); vibrational spectroscopy; atomic force microscopy (AFM); elastic modulus; friction; additives; polyethylene AB Surface-specific IR+visible sum frequency generation (SFG) spectroscopy was used to obtain chemical composition of two polymer surfaces. The SFG surface vibrational spectrum of pure low density polyethylene and that of a commercial sample of the same kind of polymer, which contains additives, are markedly different. This correlates well with the very different surface mechanical properties, i.e., stiffness (indicative of the elastic modulus) and friction, which were measured by atomic force microscopy (AFM) on the same polymer surfaces. The surface of CLDPE is dominated by methoxy (-OCH(3)) contained additives, segregated from the bulk, which explains a lower stiffness, adhesion and friction of the surface, as measured by AFM. C1 [Gracias, D. H.; Zhang, D.; Somorjai, G. A.] Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. [Shen, Y. R.] Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. [Gracias, D. H.; Zhang, D.; Shen, Y. R.; Somorjai, G. A.] Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. RP Somorjai, GA (reprint author), Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. OI Gracias, David/0000-0003-2735-4725 FU Office of Energy Research, Office of Basic Energy Sciences, Materials Sciences Division, of the U.S. Department of Energy [DE-AC0376SF00098] FX This work was supported by the Director, Office of Energy Research, Office of Basic Energy Sciences, Materials Sciences Division, of the U.S. Department of Energy under Contract No. DE-AC0376SF00098. NR 16 TC 8 Z9 8 U1 1 U2 10 PU SPRINGER/PLENUM PUBLISHERS PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 1023-8883 J9 TRIBOL LETT JI Tribol. Lett. PD MAY PY 1998 VL 4 IS 3-4 BP 231 EP 235 DI 10.1023/A:1019175826460 PG 5 WC Engineering, Chemical; Engineering, Mechanical SC Engineering GA V17SK UT WOS:000207956700002 ER PT J AU Frost, BG Voelkl, E AF Frost, BG Voelkl, E TI On the reliability of quantitative phase measurements by low magnification off-axis image plane electron holography SO ULTRAMICROSCOPY LA English DT Article DE electron holography ID MAGNETIC-FIELDS AB We experimentally found that the object wave function of an electron wave in a transmission electron microscope can depend on the diameter of the condenser aperture and on the excitation of the objective lens. This can be seen by low magnification holograms utilizing as sample electrically charged latex spheres of different diameters, the electric field at a pn-junction and the magnetic leakage field of a magnetic memory cell. (C) 1998 Published by Elsevier Science B.V. All rights reserved. C1 Univ Tennessee, EM Facil, Knoxville, TN 37996 USA. Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Frost, BG (reprint author), Univ Tennessee, EM Facil, Knoxville, TN 37996 USA. NR 14 TC 7 Z9 7 U1 0 U2 4 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0304-3991 J9 ULTRAMICROSCOPY JI Ultramicroscopy PD MAY PY 1998 VL 72 IS 3-4 BP 101 EP 107 DI 10.1016/S0304-3991(98)00015-1 PG 7 WC Microscopy SC Microscopy GA ZQ791 UT WOS:000073903400001 ER PT J AU Bernath, P Sinquefield, SA Baxter, LL Sclippa, G Rohlfing, CM Barfield, M AF Bernath, P Sinquefield, SA Baxter, LL Sclippa, G Rohlfing, CM Barfield, M TI In situ analysis of ash deposits from black liquor combustion SO VIBRATIONAL SPECTROSCOPY LA English DT Article DE black liquor; ash deposits; in situ analysis ID INFRARED-EMISSION SPECTROSCOPY; RAMAN-SPECTRA; FREQUENCIES; MOLECULES; IR AB Aerosols formed during combustion of black liquor cause a significant fire-side fouling problem in pulp mill recovery boilers. (Black liquor is a recycled by-product formed during the pulping of wood in the paper-making industry). The ash deposits reduce heat transfer effectiveness, plug gas passages, and contribute to corrosion. Both vapors and condensation aerosols lead to the formation of such deposits. The high ash content of the fuel and the low dew point of the condensate salts lead to a high aerosol and vapor concentration in most boilers. In situ measurements of the chemical composition of these deposits is an important step in gaining a fundamental understanding of the deposition process. Infrared emission spectroscopy is used to characterize the composition of thin film deposits resulting from the combustion of black Liquor and the deposition of submicron aerosols and vapors. New reference spectra of Na2SO4, K2SO4, Na2CO3 and K2CO3 pure component films were recorded and compared with the spectra of the black liquor deposit. All of the black liquor emission bands were identified using our new reference spectra as well as literature data and ab initio calculations. The ab initio calculations predict the locations and intensities of infrared bands for the alkali-containing vapors of interest. (C) 1998 Elsevier Science B.V. All rights reserved. C1 Sandia Natl Labs, Combust Res Facil, Livermore, CA 94551 USA. Univ Waterloo, Dept Chem, Waterloo, ON N2L 3G1, Canada. Oregon State Univ, Dept Chem Engn, Corvallis, OR 97331 USA. Univ Arizona, Dept Chem, Tucson, AZ 85721 USA. RP Bernath, P (reprint author), Sandia Natl Labs, Combust Res Facil, Livermore, CA 94551 USA. RI Bernath, Peter/B-6567-2012; Baxter, Larry/C-8567-2009 OI Bernath, Peter/0000-0002-1255-396X; Baxter, Larry/0000-0002-0453-2659 NR 39 TC 5 Z9 5 U1 1 U2 12 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0924-2031 J9 VIB SPECTROSC JI Vib. Spectrosc. PD MAY PY 1998 VL 16 IS 2 BP 95 EP 103 DI 10.1016/S0924-2031(98)00002-2 PG 9 WC Chemistry, Analytical; Chemistry, Physical; Spectroscopy SC Chemistry; Spectroscopy GA 104XT UT WOS:000075042500001 ER PT J AU McDonald, LM Evangelou, VP Bertsch, PM AF McDonald, LM Evangelou, VP Bertsch, PM TI The potential role of sediment mineralogy in regulating aluminum concentrations in lakewater SO WATER AIR AND SOIL POLLUTION LA English DT Article DE 2 : 1 clay minerals; Al-hydroxy; aluminum; equilibria; hydroxylation; interlayers ID SPODOSOL BS HORIZONS; RATES AB An understanding of the controls on aluminum solubility is essential because Al can reach toxic levels in waters that are affected by acidic precipitation or acid mine drainage. One factor which has received little attention is the role of in-lake sinks for Al. We hypothesized that a chloritization mechanism was capable of removing large amounts of Al from solution when sediments contained 2:1 minerals without well-developed Al-hydroxy interlayers. The objective of this investigation was to evaluate the potential role of lake sediments in regulating Al equilibria in the overlying waters. Water chemistry data, sediment mineralogy and exchange phase composition, and Al sorption isotherms were used. Sediments with well developed Al-hydroxy interlayers sorbed less total Al, accumulated more Al on the readily reversible exchange phase, and had less pH buffering capacity than sediments without Al-hydroxy interlayers. We conclude that the mineralogy of lake sediments needs to be considered when evaluating Al equilibria in lakes. C1 Univ Kentucky, Dept Agron, Lexington, KY 40546 USA. Univ Georgia, Savannah River Ecol Lab, Aiken, SC 29802 USA. RP McDonald, LM (reprint author), Univ Kentucky, Dept Agron, Lexington, KY 40546 USA. NR 25 TC 3 Z9 3 U1 0 U2 1 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0049-6979 J9 WATER AIR SOIL POLL JI Water Air Soil Pollut. PD MAY PY 1998 VL 104 IS 1-2 BP 41 EP 55 DI 10.1023/A:1004954910658 PG 15 WC Environmental Sciences; Meteorology & Atmospheric Sciences; Water Resources SC Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences; Water Resources GA ZL878 UT WOS:000073482600004 ER PT J AU Zhang, DX Winter, CL AF Zhang, DX Winter, CL TI Nonstationary stochastic analysis of steady state flow through variably saturated, heterogeneous media SO WATER RESOURCES RESEARCH LA English DT Article ID ANISOTROPIC POROUS FORMATIONS; SOIL HYDRAULIC-PROPERTIES; SOLUTE TRANSPORT; UNSATURATED FLOW; VELOCITY COVARIANCE; FIELD-SCALE; DISPERSION; MACRODISPERSION; MODEL; AQUIFERS AB In this study we develop a first-order, nonstationary stochastic model for steady state, unsaturated flow in randomly heterogeneous media. The model is applicable to the entire domain of a bounded vadose zone, unlike most of the existing stochastic models. Because of its nonstationarity, we solve it by the numerical technique of finite differences, which renders the flexibility in handling different boundary conditions, input covariance structures, and soil constitutive relationships. We illustrate the model results in one and two dimensions for soils described by the Brooks-Corey constitutive model; It is found that the flow quantities such as suction head, effective water content, unsaturated hydraulic conductivity, and velocity are nonstationary near the water table and approach stationarity as the vertical distance from the water table increases. The stationary limits and the critical vertical distance at which stationarity is attained depend on soil types and recharge rates. The smaller the recharge rate is, the larger the critical distance; and the coarser the soil texture is, the smaller the distance. One important implication of this is that the existing simpler, gravity-dominated flow models may provide good approximations for flow in vadose zones of large thickness and/or coarse-textured soils although they may not be valid for vadose zones of fine-textured soils with a shallow water table. It is also found that the vertical extent of a domain where nonstationarity is important may be estimated by solving the one-dimensional Richards equation for mean head with average soil properties and appropriate boundary conditions. On the basis of the mean head, one may then determine whether the full, nonstationary model must be solved or whether a simpler, gavity-dominated model will suffice. The flow quantities are also nonstationary in the horizontal direction near the lateral boundaries, as found for flow in saturated zones. C1 Univ Calif Los Alamos Natl Lab, Geoanal Grp, Los Alamos, NM 87545 USA. RP Zhang, DX (reprint author), Univ Calif Los Alamos Natl Lab, Geoanal Grp, EES 5,MS F665, Los Alamos, NM 87545 USA. RI Zhang, Dongxiao/D-5289-2009; Winter, C. Larrabee/D-3918-2013 OI Zhang, Dongxiao/0000-0001-6930-5994; NR 34 TC 33 Z9 37 U1 0 U2 4 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0043-1397 J9 WATER RESOUR RES JI Water Resour. Res. PD MAY PY 1998 VL 34 IS 5 BP 1091 EP 1100 DI 10.1029/97WR03661 PG 10 WC Environmental Sciences; Limnology; Water Resources SC Environmental Sciences & Ecology; Marine & Freshwater Biology; Water Resources GA ZL188 UT WOS:000073407600013 ER PT J AU Waters, RD Gruebel, MM AF Waters, RD Gruebel, MM TI Some considerations for modeling doses from radionuclides transported through groundwater SO WATER RESOURCES RESEARCH LA English DT Article AB Analysts typically incorporate into groundwater pathway models for low-level radioactive waste a simplified approach for the buildup and decay of radioactive progeny during environmental transport. The inventory is transported to the exposure point, with doses calculated there for the parent and progeny based on predicted concentrations of the parent radionuclides. This approach generally provides conservative values because maximum combined doses are larger than they would be if transport of parent and progeny were based on differing travel times. For some radionuclides, however, the approach causes underestimation of doses. Because of buildup of radiologically significant progeny, the dose at the exposure point may be higher at later arrival times than at the parent's arrival time. Also, if a parent radionuclide is shorter-lived and less mobile than one of its progeny, the parent may reach maximum dose before the progeny. We developed an alternate approach that provides conservative doses for these radionuclides. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Waters, RD (reprint author), Sandia Natl Labs, Mail Stop 0734,POB 5000, Albuquerque, NM 87185 USA. NR 10 TC 2 Z9 2 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0043-1397 J9 WATER RESOUR RES JI Water Resour. Res. PD MAY PY 1998 VL 34 IS 5 BP 1215 EP 1221 DI 10.1029/98WR00433 PG 7 WC Environmental Sciences; Limnology; Water Resources SC Environmental Sciences & Ecology; Marine & Freshwater Biology; Water Resources GA ZL188 UT WOS:000073407600022 ER PT J AU Moon, JS Simmons, JA Blount, MA Baca, WE Reno, JL Hafich, MJ AF Moon, JS Simmons, JA Blount, MA Baca, WE Reno, JL Hafich, MJ TI Gate-controlled double electron layer tunnelling transistor and single transistor digital logic applications SO ELECTRONICS LETTERS LA English DT Article AB A novel entirely planar quantum transistor based on tunnelling between two separate electron layers in an AlGaAs/GaAs double quantum well heterostructure is demonstrated. Using the gate-tunability of the tunnelling I-V characteristics, digital logic gates such as XOR and NAND are demonstrated using a single double electron layer tunnelling transistor. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Moon, JS (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. NR 7 TC 4 Z9 4 U1 1 U2 4 PU IEE-INST ELEC ENG PI HERTFORD PA MICHAEL FARADAY HOUSE SIX HILLS WAY STEVENAGE, HERTFORD SG1 2AY, ENGLAND SN 0013-5194 J9 ELECTRON LETT JI Electron. Lett. PD APR 30 PY 1998 VL 34 IS 9 BP 921 EP 922 DI 10.1049/el:19980650 PG 2 WC Engineering, Electrical & Electronic SC Engineering GA ZQ326 UT WOS:000073847300068 ER PT J AU Lucier, GM Whalen, JM Bartlett, N AF Lucier, GM Whalen, JM Bartlett, N TI High yield room temperature syntheses of KAgF4 and AgF3 and the preparation and unit cell of LiAgF4 SO JOURNAL OF FLUORINE CHEMISTRY LA English DT Article DE KAgF4; LiAgF4; AgF3; aHF; sunlight ID ANHYDROUS HYDROGEN-FLUORIDE; SILVER TRIFLUORIDE; CRYSTAL-STRUCTURE; OXIDATION; GOLD AB AgF2 dissolves at similar to 20 degrees C in liquid anhydrous hydrogen fluoride (aHF), containing either LiF or KF, with sunlight or ultraviolet (UV)-irradiated F-2. Concentrated KF-aHF solutions quickly give a nearly quantitative conversion to KAgF4. Preparation of LiAgF4 is less efficient, but it can be prepared in high purity. It is isomorphous with LiAuF4, and has a monoclinic unit cell: a = 4.87(1); b = 5.93(1); c = 10.08(1) Angstrom; beta = 93.0(1)degrees; V = 291(1) Angstrom(3), z = 4. KHF2 impurity in KAgF4 can be removed as KPF6 with PF5 at 0 degrees C. Preparation of AgF3, with minimum contamination by Ag3F8, is achieved at 0 degrees C using GeF4 as F- acceptor. The high solubility of the salt K2GeF6 makes this possible. (C) 1998 Elsevier Science S.A. All rights reserved. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Div Chem Sci, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. RP Bartlett, N (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Div Chem Sci, Berkeley, CA 94720 USA. NR 16 TC 22 Z9 22 U1 1 U2 3 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0022-1139 J9 J FLUORINE CHEM JI J. Fluor. Chem. PD APR 30 PY 1998 VL 89 IS 1 BP 101 EP 104 DI 10.1016/S0022-1139(98)00093-1 PG 4 WC Chemistry, Inorganic & Nuclear; Chemistry, Organic SC Chemistry GA ZJ736 UT WOS:000073247800018 ER PT J AU Shkrob, IA Liu, AD Sauer, MC Schmidt, KH Trifunac, AD AF Shkrob, IA Liu, AD Sauer, MC Schmidt, KH Trifunac, AD TI Hole injection and formation of polarons in cycloalkane liquids SO JOURNAL OF PHYSICAL CHEMISTRY B LA English DT Article ID HIGH-MOBILITY IONS; TEMPERATURE-DEPENDENCE; TRANSIENT ABSORPTION; DISORDERED-SYSTEMS; ELECTRON-TRANSPORT; MOLECULAR-SOLIDS; RATE CONSTANTS; POSITIVE-IONS; CONDUCTIVITY; CYCLOHEXANE AB In several cycloalkanes, ionization of the solvent or photoexcitation of a solute radical cation results in the formation of rapidly hopping solvent holes. Here we report the temperature dependence of scavenging rate constants and conductivity signals (220 to 350 K) for the solvent holes in liquid cyclohexane, methylcyclohexane, and Decalins. Our results indicate that the hopping in Decalins and methylcyclohexane is thermally activated; the activation energies are of the same order as the energy of solvent reorganization. In cyclohexane, the hopping does not seem to be thermally activated. We discuss the hypothesis that the mobile solvent holes in cycloalkanes are small polarons migrating by phonon-assisted hopping. C1 Argonne Natl Lab, Div Chem, Argonne, IL 60439 USA. Beijing Normal Univ, Inst Low Energy Nucl Phys, Beijing 100875, Peoples R China. RP Argonne Natl Lab, Div Chem, 9700 S Cass Ave, Argonne, IL 60439 USA. NR 59 TC 10 Z9 10 U1 1 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 1520-6106 J9 J PHYS CHEM B JI J. Phys. Chem. B PD APR 30 PY 1998 VL 102 IS 18 BP 3363 EP 3370 DI 10.1021/jp973110+ PG 8 WC Chemistry, Physical SC Chemistry GA ZN306 UT WOS:000073632700010 ER PT J AU Shkrob, IA Liu, AD Sauer, MC Schmidt, KH Trifunac, AD AF Shkrob, IA Liu, AD Sauer, MC Schmidt, KH Trifunac, AD TI Reversible hole trapping in liquid cyclohexane SO JOURNAL OF PHYSICAL CHEMISTRY B LA English DT Article ID HIGH-MOBILITY IONS; RADIOLYSIS; CATION; PHOTOCONDUCTIVITY; TIME AB Mobile solvent holes in cyclohexane can be reversibly trapped by methylcyclohexane (Delta G degrees = -0.11 eV), 1,1-dimethylcyclopentane (Delta G degrees = -0.20 eV), trans-1,2-dimethylcyclopentane (Delta G degrees = -0.25 eV), and 2,3-dimethylpentane (Delta G degrees = -0.21 eV). The two dimethylcyclopentanes are identified as "special" impurities responsible for bimodal scavenging kinetics of the solvent holes. The mechanism of the reversible trapping is shown to be charge transfer. Neither the difference in the ionization potentials Delta IPliq of the solvent and the solute, nor the driving force Delta G degrees of the scavenging reaction are found to correlate with the rate constants of this charge transfer. The proposed explanation is that these rate constants are controlled by the height of the activation barrier that can be estimated from the difference in the vertical IP for the solute and adiabatic IP of the solvent. The correlation of the rate constants with this difference suggests that electron transfer involving mobile holes occurs much faster than the relaxation time of the solute radical cations. This work gives the first data on adiabatic IP for saturated hydrocarbons in solution. C1 Argonne Natl Lab, Div Chem, Argonne, IL 60439 USA. RP Shkrob, IA (reprint author), Argonne Natl Lab, Div Chem, 9700 S Cass Ave, Argonne, IL 60439 USA. NR 28 TC 8 Z9 8 U1 1 U2 3 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 1089-5647 J9 J PHYS CHEM B JI J. Phys. Chem. B PD APR 30 PY 1998 VL 102 IS 18 BP 3371 EP 3378 DI 10.1021/jp9731112 PG 8 WC Chemistry, Physical SC Chemistry GA ZN306 UT WOS:000073632700011 ER PT J AU Rufael, TS Huntley, DR Mullins, DR Gland, JL AF Rufael, TS Huntley, DR Mullins, DR Gland, JL TI Adsorption and reaction of dimethyl disulfide on the Ni(111) surface SO JOURNAL OF PHYSICAL CHEMISTRY B LA English DT Article ID (5-ROOT-3X2)S PHASE; METHYL THIOLATE; METHANETHIOL; SULFUR; DECOMPOSITION; NI(100); CARBON; RECONSTRUCTION; CHEMISORPTION; CU(111) AB The adsorption and reactions of dimethyl disulfide, CH3S-SCH3, have been analyzed on the Ni(lll) surface using high-resolution electron energy-loss spectroscopy (HREELS), X-ray photoelectron spectroscopy (XPS), low-energy electron diffraction (LEED), Auger electron spectroscopy (AES), temperature programmed desorption (TPD), and deuterium labeling. All of the S-S bonds in dimethyl disulfide (DMDS) are broken below 150 K, forming methyl thiolate (CH3S) as the primary surface intermediate. Condensed DMDS desorbs at 166 K. Methane, ethane, and hydrogen are the main desorption products from the reaction of the adsorbed disulfide with Ni(lll). The methane desorption following adsorption of DMDS and CH3SH is remarkably similar. Like methanethiol, total decomposition is favored for DMDS at low coverages, while hydrocarbon formation is the main reaction pathway for higher coverages. The methane desorption profiles for DMDS coadsorbed with hydrogen are similar to those observed from methanethiol coadsorbed with hydrogen. Coadsorption of deuterium with high coverages of DMDS results in an increased temperature (+22 K) for the methane formation reaction, indicating that C-H(D) bond formation is the rate-limiting step in CH4 formation at high DMDS coverages. Disproportionation and coupling reactions between the adsorbed thiolates are the main reaction mechanisms for methane and ethane formation, respectively. Analysis of the C Is XPS peak areas and TPD intensities suggests that by 550 K approximately 85% of the saturated surface thiolate desorbs as gaseous methane and ethane. Annealing a saturation exposure of DMDS (>0.33 ML) on the Ni(lll) surface results in a complex LEED pattern as a result of the reconstruction of the top Ni layer. Surface reconstruction starts below room temperature and for S coverages as low as 0.10 ML. C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. Univ Michigan, Dept Chem, Ann Arbor, MI 48109 USA. RP Huntley, DR (reprint author), Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. NR 32 TC 31 Z9 31 U1 2 U2 13 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 1089-5647 J9 J PHYS CHEM B JI J. Phys. Chem. B PD APR 30 PY 1998 VL 102 IS 18 BP 3431 EP 3440 DI 10.1021/jp972991h PG 10 WC Chemistry, Physical SC Chemistry GA ZN306 UT WOS:000073632700020 ER PT J AU Tallarek, U van Dusschoten, D Van As, H Bayer, E Guiochon, G AF Tallarek, U van Dusschoten, D Van As, H Bayer, E Guiochon, G TI Study of transport phenomena in chromatographic columns by pulsed field gradient NMR SO JOURNAL OF PHYSICAL CHEMISTRY B LA English DT Article ID LIQUID-CHROMATOGRAPHY; STIMULATED ECHO; POROUS SOLIDS; DIFFUSION; PACKINGS; PERFORMANCE; VELOCITY; EQUATION; FLUIDS; MEDIA AB Pulsed field gradient NMR has been applied to study mass transfer, flow, and dispersion in packed chromatographic columns. A single measurement allows the determination of the full displacement probability distribution of all fluid particles located in the measurement volume. Depending on the orientation of the pulsed magnetic field gradient with respect to the net flow direction, these-called averaged propagator is obtained independently and quantitatively for either the axial or the transverse fluid particle displacements, over an experimentally adjustable observation time. Thus, this technique can act on a dynamic time scale ranging from a few to several hundred milliseconds. This enabled us to detect the stagnant mobile phase in packed chromatographic columns and to follow the mass transfer between the stagnant solvent and the stream of mobile phase percolating through the column bed. With field gradients in the direction of net flow velocity, mean fluid particle displacements ranging between 0.07 and 100 times the average diameter of the stationary phase particles could be analyzed in terms of the intimately associated averaged propagator, with observation times between 30 and 960 ms. Starting in the absence of flow, the development from the Gaussian propagator for molecular diffusion in the packing (centered at zero net displacement) toward the fully established Gaussian propagator (parallel to the onset and increase of externally driven flow) is recorded, characterizing convection-driven dispersion in the packing. For short observation times, the mass transfer between the deep pools of; stagnant mobile phase in the totally porous support particles and the interstitial space in the packed bed lis found to be incomplete and the transition toward complete exchange is followed. The results indicate that the stagnant mobile-phase mass transfer in the classical HPLC silica-based stationary phase is purely diffusion-controlled. C1 Univ Tennessee, Dept Chem, Knoxville, TN 37996 USA. Oak Ridge Natl Lab, Div Chem & Analyt Sci, Oak Ridge, TN 37831 USA. Univ Tubingen, Inst Organ Chem, D-72076 Tubingen, Germany. Agr Univ Wageningen, Dept Mol Phys, NL-6703 HA Wageningen, Netherlands. Wageningen NMR Ctr, NL-6703 HA Wageningen, Netherlands. RP Guiochon, G (reprint author), Univ Tennessee, Dept Chem, Knoxville, TN 37996 USA. RI Van As, Henk/A-2787-2013 OI Van As, Henk/0000-0003-1076-391X NR 46 TC 67 Z9 67 U1 2 U2 11 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 1089-5647 J9 J PHYS CHEM B JI J. Phys. Chem. B PD APR 30 PY 1998 VL 102 IS 18 BP 3486 EP 3497 DI 10.1021/jp980250q PG 12 WC Chemistry, Physical SC Chemistry GA ZN306 UT WOS:000073632700026 ER PT J AU Heatherly, L George, EP Liu, CT Kumar, KS AF Heatherly, L George, EP Liu, CT Kumar, KS TI An Auger investigation of the grain-boundary chemistry in Ni-3(Si,Ti) alloys SO MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING LA English DT Article DE environmental embrittlement; stoichiometry; Auger microscopy; Ni3Si ID BORON; NI3AL; EMBRITTLEMENT; SEGREGATION; NI3(SI,TI); FRACTURE; NI3SI AB Three different Ni-3(Si,Ti) alloys were cathodically charged with hydrogen and fractured under high vacuum conditions. Scanning Auger microscopy (SAM) and scanning electron microscopy (SEM) were used to determine the chemical compositions of the fracture surfaces and the mode of fracture. The compositions of the transgranular regions were compared with the intergranular regions in order to determine the amount of grain-boundary segregation or depletion of the various constituents. In all the alloys studied, Si and Ti were depleted on the grain boundaries, while Ni was enriched relative to the bulk. Correlations were made between the grain-boundary compositions and the previously reported environmental embrittlement of these alloys. An embrittlement factor defined as [(Si + Ti)/Ti] on the grain boundaries is suggested to be related to the degree of environmental embrittlement at ambient temperatures. Some possible reasons for this correlation are discussed. (C) 1998 Elsevier Science S.A. All rights reserved. C1 Oak Ridge Natl Lab, Div Met & Ceram, Oak Ridge, TN 37831 USA. Brown Univ, Div Engn, Providence, RI 02912 USA. RP Heatherly, L (reprint author), Oak Ridge Natl Lab, Div Met & Ceram, POB 2008, Oak Ridge, TN 37831 USA. RI George, Easo/L-5434-2014; OI Liu, Chain Tsuan/0000-0001-7888-9725 NR 10 TC 9 Z9 9 U1 0 U2 5 PU ELSEVIER SCIENCE SA 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 APR 30 PY 1998 VL 245 IS 1 BP 80 EP 87 DI 10.1016/S0921-5093(97)00691-6 PG 8 WC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Science & Technology - Other Topics; Materials Science; Metallurgy & Metallurgical Engineering GA ZM094 UT WOS:000073504100010 ER PT J AU Christen, D AF Christen, D TI Superconductors - Current limits to wire technology SO NATURE LA English DT Editorial Material C1 Oak Ridge Natl Lab, Div Solid State, Oak Ridge, TN 37831 USA. RP Christen, D (reprint author), Oak Ridge Natl Lab, Div Solid State, POB 2008, Oak Ridge, TN 37831 USA. NR 7 TC 8 Z9 9 U1 0 U2 0 PU MACMILLAN MAGAZINES LTD PI LONDON PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW SN 0028-0836 J9 NATURE JI Nature PD APR 30 PY 1998 VL 392 IS 6679 BP 862 EP 863 DI 10.1038/31801 PG 2 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA ZK759 UT WOS:000073359900020 ER PT J AU Acciarri, M Adriani, O Aguilar-Benitez, M Ahlen, S Alcaraz, J Alemanni, G Allaby, J Aloisio, A Alviggi, MG Ambrosi, G Anderhub, H Andreev, VP Angelescu, T Anselmo, F Arefiev, A Azemoon, T Aziz, T Bagnaia, P Baksay, L Ball, RC Banerjee, S Banerjee, S Banicz, K Barczyk, A 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, BL Bhattacharya, S Biasini, M Biland, A Bilei, GM Blaising, JJ Blyth, SC Bobbink, GJ Bock, R Bohm, A Boldizsar, L Borgia, B Bourilkov, D Bourquin, M Boutigny, D Braccini, S Branson, JG Brigljevic, V Brock, IC Buffini, A Buijs, A Burger, JD Burger, WJ Busenitz, J Cai, XD Campanelli, M Capell, M Romeo, GC Carlino, G Cartacci, AM Casaus, J Castellini, G Cavallari, F Cavallo, N Cecchi, C Cerrada, M Cesaroni, F Chamizo, M Chang, YH Chaturvedi, UK Chekanov, SV Chemarin, M Chen, A Chen, G Chen, GM Chen, HF Chen, HS Chen, M Chiefari, G Chien, CY Cifarelli, L Cindolo, F Civinini, C Clare, I Clare, R Cohn, HO Coignet, G Colijn, AP Colino, N Costantini, S Cotorobai, F de la Cruz, B Csilling, A Dai, TS D'Alessandro, R de Asmundis, R Degre, A Deiters, K Denes, P DeNotaristefani, F DiBitonto, D Diemoz, M van Dierendonck, D Di Lodovico, F Dionisi, C Dittmar, M Dominguez, A Doria, A Dova, MT Drago, E Duchesneau, D Duinker, P Duran, I Dutta, S Easo, S Efremenko, Y El Mamouni, 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 Ferroni, F Fesefeldt, H Fiandrini, E Field, JH Filthaut, F Fisher, PH Fisk, I Forconi, G Fredj, L Freudenreich, K Furetta, C Galaktionov, Y Ganguli, SN Garcia-Abia, 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 Haas, D Hartmann, B Hasan, A Hatzifotiadou, D Hebbeker, T Herve, A Hirschfelder, J van Hoek, WC Hofer, H Hoorani, H Hou, SR Hu, G Innocente, V Jenkes, K Jin, BN Jones, LW de Jong, P Josa-Mutuberria, I Kasser, A Khan, RA Kamrad, D Kamyshkov, Y Kapustinsky, JS Karyotakis, Y Kaur, M Kienzle-Focacci, MN Kim, D Kim, DH Kim, JK Kim, SC Kinnison, WW Kirkby, A Kirkby, D Kirkby, J Kiss, D Kittel, W Klimentov, A Konig, AC Kopp, A Korolko, I Koutsenko, V Kraemer, RW Krenz, W Kunin, A Lacentre, P de Guevara, PL Landi, G Lapoint, C Lassila-Perini, K Laurikainen, P Lavorato, A Lebeau, M Lebedev, A Lebrun, P Lecomte, P Lecoq, P Le Coultre, P Lee, HJ Leggett, C Le Goff, JM Leiste, R Leonardi, E Levtchenko, P Li, C Lin, CH 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 Mana, 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 von der Mey, M Mi, Y Migani, D Mihul, A van Mil, AJW Milcent, H Mirabelli, G Mnich, J Molnar, P Monteleoni, B Moore, R Moulik, T Mount, R Muheim, F Niessen, T Nippe, A Nisati, A Nowak, H Oh, YD Opitz, H Organtini, G Ostonen, R Palit, S Palomares, C Pandoulas, D Paoletti, S Paolucci, P Park, HK Park, IH Pascale, G Passaleva, G Patricelli, S Paul, T Pauluzzi, M Paus, C Pauss, F Peach, D Pei, YJ Pensotti, S Perret-Gallix, D Petersen, B Petrak, S Pevsner, A Picolo, D Pieri, M Piroue, PA Pistolesi, E Plyaskin, V Pohl, M Pojidaev, V Postema, H Produit, N Prokofiev, D Quartieri, J Rahal-Callot, G Raja, N Rancoita, PG Rattaggi, M Raven, G Razis, P Read, K Ren, D Rescigno, M Reucroft, S van Rhee, T Riemann, S Riles, K Rind, O Robohm, A Rodin, J Roe, BP Romero, L Rosier-Lees, S Rosselet, P van Rossum, W Roth, S Rubio, JA Ruschmeier, D Rykaczewski, H Salicio, J Sanchez, E Sanders, MP Sarakinos, ME Sarkar, S Sauvage, G Schafer, C Schneegans, M Scholz, N Schegelsky, V Schmidt-Kaerst, S Schmitz, D Schopper, H Schotanus, DJ Schwenke, J Schwering, G Sciacca, C Sciarrino, D Servoli, L Shevchenko, S Shivarov, N Shoutko, V Shukla, J Shumilov, E Shvorob, A Siedenburg, T Son, D Soulimov, V Smith, B Spillantini, P Steuer, M Stickland, DP Stone, H Stoyanov, B Straessner, A Sudhakar, K Sultanov, G Sun, LZ Susinno, GF Suter, H Swain, JD Tang, XW Tauscher, L Taylor, L Ting, SCC Ting, SM Tonwar, SC Toth, J Tully, C Tuchscherer, H Tung, KL Uchida, Y Ulbricht, J Uwer, U Valente, E Vesztergombi, G Vetlitsky, I Viertel, G Vivargent, M Vlachos, S Volkert, R Vogel, H Vogt, H Vorobiev, I Vorobyov, AA Vorvolakos, A Wadhwa, M Wallraff, W Wang, JC Wang, XL Wang, ZM Weber, A 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 Aguilar-Benitez, M Ahlen, S Alcaraz, J Alemanni, G Allaby, J Aloisio, A Alviggi, MG Ambrosi, G Anderhub, H Andreev, VP Angelescu, T Anselmo, F Arefiev, A Azemoon, T Aziz, T Bagnaia, P Baksay, L Ball, RC Banerjee, S Banerjee, S Banicz, K Barczyk, A 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, BL Bhattacharya, S Biasini, M Biland, A Bilei, GM Blaising, JJ Blyth, SC Bobbink, GJ Bock, R Bohm, A Boldizsar, L Borgia, B Bourilkov, D Bourquin, M Boutigny, D Braccini, S Branson, JG Brigljevic, V Brock, IC Buffini, A Buijs, A Burger, JD Burger, WJ Busenitz, J Cai, XD Campanelli, M Capell, M Romeo, GC Carlino, G Cartacci, AM Casaus, J Castellini, G Cavallari, F Cavallo, N Cecchi, C Cerrada, M Cesaroni, F Chamizo, M Chang, YH Chaturvedi, UK Chekanov, SV Chemarin, M Chen, A Chen, G Chen, GM Chen, HF Chen, HS Chen, M Chiefari, G Chien, CY Cifarelli, L Cindolo, F Civinini, C Clare, I Clare, R Cohn, HO Coignet, G Colijn, AP Colino, N Costantini, S Cotorobai, F de la Cruz, B Csilling, A Dai, TS D'Alessandro, R de Asmundis, R Degre, A Deiters, K Denes, P DeNotaristefani, F DiBitonto, D Diemoz, M van Dierendonck, D Di Lodovico, F Dionisi, C Dittmar, M Dominguez, A Doria, A Dova, MT Drago, E Duchesneau, D Duinker, P Duran, I Dutta, S Easo, S Efremenko, Y El Mamouni, 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 Ferroni, F Fesefeldt, H Fiandrini, E Field, JH Filthaut, F Fisher, PH Fisk, I Forconi, G Fredj, L Freudenreich, K Furetta, C Galaktionov, Y Ganguli, SN Garcia-Abia, 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 Haas, D Hartmann, B Hasan, A Hatzifotiadou, D Hebbeker, T Herve, A Hirschfelder, J van Hoek, WC Hofer, H Hoorani, H Hou, SR Hu, G Innocente, V Jenkes, K Jin, BN Jones, LW de Jong, P Josa-Mutuberria, I Kasser, A Khan, RA Kamrad, D Kamyshkov, Y Kapustinsky, JS Karyotakis, Y Kaur, M Kienzle-Focacci, MN Kim, D Kim, DH Kim, JK Kim, SC Kinnison, WW Kirkby, A Kirkby, D Kirkby, J Kiss, D Kittel, W Klimentov, A Konig, AC Kopp, A Korolko, I Koutsenko, V Kraemer, RW Krenz, W Kunin, A Lacentre, P de Guevara, PL Landi, G Lapoint, C Lassila-Perini, K Laurikainen, P Lavorato, A Lebeau, M Lebedev, A Lebrun, P Lecomte, P Lecoq, P Le Coultre, P Lee, HJ Leggett, C Le Goff, JM Leiste, R Leonardi, E Levtchenko, P Li, C Lin, CH 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 Mana, 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 von der Mey, M Mi, Y Migani, D Mihul, A van Mil, AJW Milcent, H Mirabelli, G Mnich, J Molnar, P Monteleoni, B Moore, R Moulik, T Mount, R Muheim, F Niessen, T Nippe, A Nisati, A Nowak, H Oh, YD Opitz, H Organtini, G Ostonen, R Palit, S Palomares, C Pandoulas, D Paoletti, S Paolucci, P Park, HK Park, IH Pascale, G Passaleva, G Patricelli, S Paul, T Pauluzzi, M Paus, C Pauss, F Peach, D Pei, YJ Pensotti, S Perret-Gallix, D Petersen, B Petrak, S Pevsner, A Picolo, D Pieri, M Piroue, PA Pistolesi, E Plyaskin, V Pohl, M Pojidaev, V Postema, H Produit, N Prokofiev, D Quartieri, J Rahal-Callot, G Raja, N Rancoita, PG Rattaggi, M Raven, G Razis, P Read, K Ren, D Rescigno, M Reucroft, S van Rhee, T Riemann, S Riles, K Rind, O Robohm, A Rodin, J Roe, BP Romero, L Rosier-Lees, S Rosselet, P van Rossum, W Roth, S Rubio, JA Ruschmeier, D Rykaczewski, H Salicio, J Sanchez, E Sanders, MP Sarakinos, ME Sarkar, S Sauvage, G Schafer, C Schneegans, M Scholz, N Schegelsky, V Schmidt-Kaerst, S Schmitz, D Schopper, H Schotanus, DJ Schwenke, J Schwering, G Sciacca, C Sciarrino, D Servoli, L Shevchenko, S Shivarov, N Shoutko, V Shukla, J Shumilov, E Shvorob, A Siedenburg, T Son, D Soulimov, V Smith, B Spillantini, P Steuer, M Stickland, DP Stone, H Stoyanov, B Straessner, A Sudhakar, K Sultanov, G Sun, LZ Susinno, GF Suter, H Swain, JD Tang, XW Tauscher, L Taylor, L Ting, SCC Ting, SM Tonwar, SC Toth, J Tully, C Tuchscherer, H Tung, KL Uchida, Y Ulbricht, J Uwer, U Valente, E Vesztergombi, G Vetlitsky, I Viertel, G Vivargent, M Vlachos, S Volkert, R Vogel, H Vogt, H Vorobiev, I Vorobyov, AA Vorvolakos, A Wadhwa, M Wallraff, W Wang, JC Wang, XL Wang, ZM Weber, A 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 CA L3 Collaboration TI Measurement of the weak dipole moments of the tau lepton SO PHYSICS LETTERS B LA English DT Article ID CP VIOLATION; POLARIZATION; DECAYS; CONSTRUCTION; SLC AB Using the data collected by the L3 experiment at LEP from 1991 to 1995 at energies around the Z mass, a measurement of the weak anomalous magnetic dipole moment, a(tau)(w), and of the weak electric dipole moment, d(tau)(w), of the tau lepton is performed. These quantities are obtained from angular distributions in e(+)e(-)--> tau(+)tau(-)--> h(+)<(nu)over bar>(tau)h(-)nu(tau), where h is a pi or a rho. The results are: Re(a(tau)(w)) = (0.0 +/- 1.6 +/- 2.3) X 10(-3), Im(a(tau)(w)) = (-1.0 +/- 3.6 +/- 4.3) X 10(-3) and Re(d(tau)(w)) = (-0.44 +/- 0.88 +/- 1.33)X 10(-17)e.cm. This is the first direct measurement of a(tau)(w). (C) 1998 Elsevier Science B,V. All rights reserved. C1 Ist Nazl Fis Nucl, Sezione Milano, I-20133 Milan, Italy. Chinese Univ Sci & Technol, USTC, Hefei 230029, Anhui, Peoples R China. Res Inst High Energy Phys, SEFT, SF-00014 Helsinki, Finland. Univ Lausanne, CH-1015 Lausanne, Switzerland. Ist Nazl Fis Nucl, Sezione Lecce, I-73100 Lecce, Italy. Univ Lecce, I-73100 Lecce, Italy. Los Alamos Natl Lab, Los Alamos, NM 87544 USA. Univ Lyon 1, Inst Phys Nucl Lyon, IN2P3, CNRS, F-69622 Villeurbanne, France. CIEMAT, Ctr Invest Energet Medioambientales & Tecnolog, E-28040 Madrid, Spain. ITEP, Inst Theoret & Expt Phys, Moscow, Russia. Ist Nazl Fis Nucl, Sezione Napoli, I-80125 Naples, Italy. Univ Naples Federico II, 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, Sezione Perugia, 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, Sezione Rome, I-00185 Rome, Italy. Univ Roma La Sapienza, I-00185 Rome, Italy. Russian Acad Sci, Inst Nucl Phys, St Petersburg, Russia. Univ Salerno, I-84100 Salerno, Italy. INFN, I-84100 Salerno, Italy. Univ Calif San Diego, La Jolla, CA 92093 USA. Univ Santiago, Dept Fis Particulas Elementales, E-15706 Santiago, Spain. Bulgarian Acad Sci, Cent Lab Mechatron & Instrumentat, BU-1113 Sofia, Bulgaria. Korea Adv Inst Sci & Technol, Ctr High Energy Phys, Taejon 305701, South Korea. Univ Alabama, University, AL 35486 USA. Univ Utrecht, NL-3584 CB Utrecht, Netherlands. NIKHEF, NL-3584 CB Utrecht, Netherlands. Purdue Univ, W Lafayette, IN 47907 USA. Paul Scherrer Inst, PSI, CH-5232 Villigen, Switzerland. DESY, Inst Hochenergiephys, D-15738 Zeuthen, Germany. Swiss Fed Inst Technol, Eidgenoss TH, CH-8093 Zurich, Switzerland. Univ Hamburg, D-22761 Hamburg, Germany. Natl Cent Univ, Chungli 32054, Taiwan. Natl Tsing Hua Univ, Dept Phys, Hsinchu, Taiwan. Rhein Westfal TH Aachen, Inst Phys 1, D-52056 Aachen, Germany. Rhein Westfal TH Aachen, Inst Phys 3, D-52056 Aachen, Germany. NIKHEF, Natl Inst High Energy Phys, NL-1009 DB Amsterdam, Netherlands. Univ Amsterdam, NL-1009 DB Amsterdam, Netherlands. Univ Michigan, Ann Arbor, MI 48109 USA. IN2P3, Lab Annecy Le Vieux Phys Particules, LAPP, 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, IHEP, Beijing 100039, Peoples R China. Humboldt Univ, D-10099 Berlin, Germany. Univ Bologna, I-40126 Bologna, Italy. INFN, Sezion Bologna, I-40126 Bologna, Italy. Tata Inst Fundamental Res, Bombay 400005, Maharashtra, India. Boston Univ, Boston, MA 02215 USA. Northeastern Univ, Boston, MA 02115 USA. Inst Atom Phys, R-76900 Bucharest, Romania. Univ Bucharest, R-76900 Bucharest, Romania. Hungarian Acad Sci, Cent Res Inst Phys, H-1525 Budapest 114, Hungary. MIT, Cambridge, MA 02139 USA. Ist Nazl Fis Nucl, Sezione Firenze, I-50125 Florence, Italy. Univ Florence, I-50125 Florence, Italy. CERN, European Lab Particle Phys, CH-1211 Geneva 23, Switzerland. World Lab, FBLJA Project, CH-1211 Geneva 23, Switzerland. Univ Geneva, CH-1211 Geneva 4, Switzerland. RP Acciarri, M (reprint author), Ist Nazl Fis Nucl, Sezione Milano, Via Celoria 16, I-20133 Milan, Italy. RI Duran, Ignacio/H-7254-2015; Rancoita, Pier Giorgio/J-9896-2015; Hoorani, Hafeez/D-1791-2013; Palomares, Carmen/H-7783-2015; Fedin, Oleg/H-6753-2016; Roth, Stefan/J-2757-2016; Kamyshkov, Yuri/J-7999-2016; Di Lodovico, Francesca/L-9109-2016; Fiandrini, Emanuele/C-4549-2008; Lista, Luca/C-5719-2008; Kirkby, Jasper/A-4973-2012; Servoli, Leonello/E-6766-2012; bertucci, bruna/J-5237-2012; Cavallo, Nicola/F-8913-2012; Cerrada, Marcos/J-6934-2014; de la Cruz, Begona/K-7552-2014; Vogel, Helmut/N-8882-2014; D'Alessandro, Raffaello/F-5897-2015; Sanchez, Eusebio/H-5228-2015; Ferguson, Thomas/O-3444-2014; Berdugo, Javier/A-2858-2015 OI Goldstein, Joel/0000-0003-1591-6014; Rancoita, Pier Giorgio/0000-0002-1990-4283; Palomares, Carmen/0000-0003-4374-9065; Roth, Stefan/0000-0003-3616-2223; Kamyshkov, Yuri/0000-0002-3789-7152; Di Lodovico, Francesca/0000-0003-3952-2175; Read, Kenneth/0000-0002-3358-7667; Sciacca, Crisostomo/0000-0002-8412-4072; Filthaut, Frank/0000-0003-3338-2247; Kirkby, Jasper/0000-0003-2341-9069; Servoli, Leonello/0000-0003-1725-9185; Cerrada, Marcos/0000-0003-0112-1691; Vogel, Helmut/0000-0002-6109-3023; D'Alessandro, Raffaello/0000-0001-7997-0306; Sanchez, Eusebio/0000-0002-9646-8198; Ferguson, Thomas/0000-0001-5822-3731; Berdugo, Javier/0000-0002-7911-8532 NR 25 TC 19 Z9 19 U1 0 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0370-2693 EI 1873-2445 J9 PHYS LETT B JI Phys. Lett. B PD APR 30 PY 1998 VL 426 IS 1-2 BP 207 EP 216 DI 10.1016/S0370-2693(98)00290-1 PG 10 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA ZU522 UT WOS:000074206500027 ER PT J AU Xu, T Barich, DH Goguen, PW Song, WG Wang, ZK Nicholas, JB Haw, JF AF Xu, T Barich, DH Goguen, PW Song, WG Wang, ZK Nicholas, JB Haw, JF TI Synthesis of a benzenium ion in a zeolite with use of a catalytic flow reactor SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Article ID IN-SITU NMR; ACIDIC ZEOLITES; SOLID ACIDS; EXCHANGE C1 Texas A&M Univ, Dept Chem, Lab Magnet Resonance & Mol Sci, College Stn, TX 77843 USA. Pacific NW Lab, Environm Mol Sci Lab, Richland, WA 99352 USA. RP Nicholas, JB (reprint author), Texas A&M Univ, Dept Chem, Lab Magnet Resonance & Mol Sci, College Stn, TX 77843 USA. NR 20 TC 78 Z9 79 U1 1 U2 24 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0002-7863 J9 J AM CHEM SOC JI J. Am. Chem. Soc. PD APR 29 PY 1998 VL 120 IS 16 BP 4025 EP 4026 DI 10.1021/ja973791m PG 2 WC Chemistry, Multidisciplinary SC Chemistry GA ZL105 UT WOS:000073399300027 ER PT J AU Vasenkov, S Frei, H AF Vasenkov, S Frei, H TI Observation of acetyl radical in a zeolite by time-resolved FT-IR spectroscopy SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Article ID LASER FLASH-PHOTOLYSIS; AB-INITIO PREDICTION; DIFFUSE-REFLECTANCE; INTRAZEOLITE PHOTOCHEMISTRY; DIPHENYLMETHYL RADICALS; FRIES REARRANGEMENT; 1-NAPHTHYL ACETATE; NAX ZEOLITE; ION-PAIRS; COMPLEXES C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Phys Biosci Div, MS Calvin Lab, Berkeley, CA 94720 USA. RP Frei, H (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Phys Biosci Div, MS Calvin Lab, Berkeley, CA 94720 USA. RI Lee, Yuan-Pern/F-7938-2012 OI Lee, Yuan-Pern/0000-0001-6418-7378 NR 34 TC 28 Z9 28 U1 0 U2 6 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0002-7863 J9 J AM CHEM SOC JI J. Am. Chem. Soc. PD APR 29 PY 1998 VL 120 IS 16 BP 4031 EP 4032 DI 10.1021/ja980119w PG 2 WC Chemistry, Multidisciplinary SC Chemistry GA ZL105 UT WOS:000073399300030 ER PT J AU Snoeck, E Warot, B Ardhuin, H Rocher, A Casanove, MJ Kilaas, R Hytch, MJ AF Snoeck, E Warot, B Ardhuin, H Rocher, A Casanove, MJ Kilaas, R Hytch, MJ TI Quantitative analysis of strain field in thin films from HRTEM micrographs SO THIN SOLID FILMS LA English DT Article; Proceedings Paper CT Symposium C on Recent Developments in Electron Microscopy and X-Ray Diffraction of Thin Film Structures at the ICAM/E-MRS Spring Conference CY JUN 16-20, 1997 CL STRASBOURG, FRANCE SP Council Europe, Commiss European Communities DE displacement; strain; GaSb/GaAs interface; HREM AB A method for measuring and mapping displacement fields and strain fields has been developed. It is based on the Fourier analysis of a HRTEM lattice image selecting a strong Bragg reflection and performing an inverse Fourier transform. The phase component of the resulting complex image gives information on local displacements of atomic planes. The two-dimensional (2D) displacement field can then be derived by applying the method to two non-collinear Fourier components. Local strain tensor components epsilon(xx)((r) over bar), epsilon(yy)((r) over bar), epsilon(xy)((r) over bar) and epsilon(yx)((r) over bar) can be obtained by analysing the derivative of the displacement field. Applied to HRTEM images of thin films, this technique gives quantitative information on the variations of the strain relaxations in the different layers. The method is illustrated studying a fully relaxed GaSb/GaAs interface. (C) 1998 Elsevier Science S.A. C1 CNRS, CEMES, F-31055 Toulouse 5, France. NCEM, LBL, Berkeley, CA 94720 USA. CNRS, Ctr Etud Chim Met, F-94407 Vitry, France. RP Snoeck, E (reprint author), CNRS, CEMES, BP4347, F-31055 Toulouse 5, France. EM snoeck@cemes.fr RI Warot-Fonrose, Benedicte/A-6131-2017 OI Warot-Fonrose, Benedicte/0000-0001-9829-9431 NR 13 TC 36 Z9 36 U1 0 U2 8 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0040-6090 J9 THIN SOLID FILMS JI Thin Solid Films PD APR 29 PY 1998 VL 319 IS 1-2 BP 157 EP 162 DI 10.1016/S0040-6090(97)01113-9 PG 6 WC Materials Science, Multidisciplinary; Materials Science, Coatings & Films; Physics, Applied; Physics, Condensed Matter SC Materials Science; Physics GA ZV702 UT WOS:000074332500034 ER PT J AU Sussman, JL Barton, GJ AF Sussman, JL Barton, GJ TI Re: Letter to the editor regarding deposition of 3D structural studies of biological macromolecules SO BIOCHEMICAL AND BIOPHYSICAL RESEARCH COMMUNICATIONS LA English DT Letter C1 Brookhaven Natl Lab, Dept Biol, Prot Data Bank, Upton, NY 11973 USA. European Bioinformat Inst, EMBL Outstn, Macromol Struct Grp, Cambridge, England. RP Sussman, JL (reprint author), Brookhaven Natl Lab, Dept Biol, Prot Data Bank, Upton, NY 11973 USA. RI Barton, Geoffrey/C-6267-2011 NR 0 TC 0 Z9 0 U1 0 U2 0 PU ACADEMIC PRESS INC PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0006-291X J9 BIOCHEM BIOPH RES CO JI Biochem. Biophys. Res. Commun. PD APR 28 PY 1998 VL 245 IS 3 BP 946 EP 946 DI 10.1006/bbrc.1998.8544 PG 1 WC Biochemistry & Molecular Biology; Biophysics SC Biochemistry & Molecular Biology; Biophysics GA ZL947 UT WOS:000073489500053 PM 9588220 ER PT J AU Trajmar, S Kanik, I Khakoo, MA LeClair, LR Bray, I Fursa, D Csanak, G AF Trajmar, S Kanik, I Khakoo, MA LeClair, LR Bray, I Fursa, D Csanak, G TI Elastic electron scattering by laser-excited Ba-138(- 6s6p P-1(1)) atoms SO JOURNAL OF PHYSICS B-ATOMIC MOLECULAR AND OPTICAL PHYSICS LA English DT Letter ID EXCITATION; BA AB The results of a combined experimental and theoretical study of elastic electron scattering by laser-excited Ba-138(...6s6p P-1(1)) atoms are presented. From these studies, we extracted differential scattering cross sections and parameters for elastic scattering both by coherently prepared P-1(1) Pa atoms and by Ba atoms in an isotropic, incoherent state of the P-1(1) level. This is the first time that results of this type have been reported for elastic scattering by excited atoms. Good agreement was found between the limited experimental results and those obtained from our convergent close-coupling (CCC) theoretical calculations. It was demonstrated that elastic scattering can create alignment with significant probability. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91125 USA. CALTECH, Div Chem & Chem Engn, Pasadena, CA 91125 USA. Calif State Univ Fullerton, Dept Phys, Fullerton, CA 92634 USA. Flinders Univ S Australia, Elect Struct Mat Ctr, Adelaide, SA 5001, Australia. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87544 USA. RP Trajmar, S (reprint author), CALTECH, Jet Prop Lab, Pasadena, CA 91125 USA. RI Fursa, Dmitry/C-2301-2009; Bray, Igor/B-8586-2009 OI Fursa, Dmitry/0000-0002-3951-9016; Bray, Igor/0000-0001-7554-8044 NR 19 TC 10 Z9 10 U1 0 U2 0 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0953-4075 J9 J PHYS B-AT MOL OPT JI J. Phys. B-At. Mol. Opt. Phys. PD APR 28 PY 1998 VL 31 IS 8 BP L393 EP L400 DI 10.1088/0953-4075/31/8/010 PG 8 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA ZM801 UT WOS:000073577200010 ER PT J AU Frauenfelder, H McMahon, B AF Frauenfelder, H McMahon, B TI Dynamics and function of proteins: The search for general concepts SO PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA LA English DT Editorial Material ID X-RAY-DIFFRACTION; LIGAND-BINDING; MYOGLOBIN; TEMPERATURE; VISCOSITY C1 Univ Calif Los Alamos Natl Lab, Ctr Nonlinear Studies, Los Alamos, NM 87545 USA. RP Frauenfelder, H (reprint author), Univ Calif Los Alamos Natl Lab, Ctr Nonlinear Studies, MS B258, Los Alamos, NM 87545 USA. NR 23 TC 101 Z9 102 U1 2 U2 11 PU NATL ACAD SCIENCES PI WASHINGTON PA 2101 CONSTITUTION AVE NW, WASHINGTON, DC 20418 USA SN 0027-8424 J9 P NATL ACAD SCI USA JI Proc. Natl. Acad. Sci. U. S. A. PD APR 28 PY 1998 VL 95 IS 9 BP 4795 EP 4797 DI 10.1073/pnas.95.9.4795 PG 3 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA ZL269 UT WOS:000073415700003 PM 9560180 ER PT J AU Jamin, N Dumas, P Moncuit, J Fridman, WH Teillaud, JL Carr, GL Williams, GP AF Jamin, N Dumas, P Moncuit, J Fridman, WH Teillaud, JL Carr, GL Williams, GP TI Highly resolved chemical imaging of living cells by using synchrotron infrared microspectrometry SO PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA LA English DT Article ID RAMAN-SPECTROSCOPY; CHROMOSOMES; SPECTRA; TISSUES; LIGHT AB Using synchrotron radiation as an ultrabright infrared source, we have been able to map the distributions of functional groups such as proteins, lipids, and nucleic acids inside a single living cell with a spatial resolution of a few microns. In particular, we have mapped the changes in the lipid and protein distributions in both the final stages of cell division and also during necrosis. C1 Ctr Univ Paris Sud, Utilisat Rayonnement Electromagnet Lab, F-91405 Orsay, France. CEA, Inst Natl Sci & Tech Nucl, F-91191 Gif Sur Yvette, France. Ctr Univ Paris Sud, CNRS, Lab Spect Infrarouge & Raman, F-91405 Orsay, France. Inst Curie, INSERM, U255, F-75248 Paris 05, France. Brookhaven Natl Lab, Natl Synchrotron Light Source, Upton, NY 11974 USA. RP Ctr Univ Paris Sud, Utilisat Rayonnement Electromagnet Lab, Batiment 209D, F-91405 Orsay, France. EM pdumas@lure.u-psud.fr NR 14 TC 187 Z9 188 U1 1 U2 21 PU NATL ACAD SCIENCES PI WASHINGTON PA 2101 CONSTITUTION AVE NW, WASHINGTON, DC 20418 USA SN 0027-8424 J9 P NATL ACAD SCI USA JI Proc. Natl. Acad. Sci. U. S. A. PD APR 28 PY 1998 VL 95 IS 9 BP 4837 EP 4840 DI 10.1073/pnas.95.9.4837 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA ZL269 UT WOS:000073415700012 PM 9560189 ER PT J AU Gualberto, A Aldape, K Kozakiewicz, K AF Gualberto, A Aldape, K Kozakiewicz, K TI An oncogenic form of p53 confers a dominant, gain-of-function phenotype that disrupts spindle checkpoint control SO PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA LA English DT Article ID TUMOR-SUPPRESSOR GENE; CELL-CYCLE ARREST; WILD-TYPE P53; MUTANT P53; FUNCTION MUTATIONS; EXPRESSION; DEFICIENT; APOPTOSIS; MITOSIS; CANCER AB Although it is well-established that p53 functions as a tumor suppresses gene, certain mutations exhibit gain-of-function activities that increase oncogenic transformation. We have found a common class of p53 missense mutations that exhibits a dominant, gain-of-function activity that generates genomic instability. Fibroblasts frown Li-Fraumeni syndrome heterozygotes with such mutations generate polyploid cells when exposed to spindle depolymerizing agents. Expression of such mutant alleles in normal fibroblasts yields the same phenotype. This class of dominant, gain-of-function p53 mutation (p53(RSC), relaxed spindle checkpoint allele) does not require the transcriptional activation function of p53 for this behavior. Thus p53 mutations can contribute to progression of a cancer cell not only by absence of p53 humor suppressor activity but also by the presence of an activity that promotes genetic instability. C1 Univ Calif San Francisco, Sch Med, Dept Pathol, San Francisco, CA 94143 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Life Sci, Berkeley, CA 94720 USA. RP Kozakiewicz, K (reprint author), Univ Calif San Francisco, Sch Med, Dept Pathol, 513 Parnassus Ave,POB 0506,HSW 451, San Francisco, CA 94143 USA. EM ttlsty@itsa.ucsf.edu FU NCI NIH HHS [CA51912, CA58207, CA42765, P50 CA058207] NR 53 TC 195 Z9 196 U1 0 U2 0 PU NATL ACAD SCIENCES PI WASHINGTON PA 2101 CONSTITUTION AVE NW, WASHINGTON, DC 20418 USA SN 0027-8424 J9 P NATL ACAD SCI USA JI Proc. Natl. Acad. Sci. U. S. A. PD APR 28 PY 1998 VL 95 IS 9 BP 5166 EP 5171 DI 10.1073/pnas.95.9.5166 PG 6 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA ZL269 UT WOS:000073415700070 PM 9560247 ER PT J AU Kurtz, SR Allerman, AA Biefeld, RM Baucom, KC AF Kurtz, SR Allerman, AA Biefeld, RM Baucom, KC TI High slope efficiency, "cascaded" midinfrared lasers with type quantum wells SO APPLIED PHYSICS LETTERS LA English DT Article AB Lasers and light-emitting diodes with multistage, type I InAsSb/InAsP quantum well active regions are reported. These ten stage, cascaded devices were grown by metalorganic chemical vapor deposition. The broadband light-emitting diodes produced high average powers, >2 mW (similar to 80 K, 3.7 mu m) and >0.1 mW (similar to 300 K, 4.3 mu m). A 3.8-3.9 mu m laser structure operated up to T = 180 K. At 80 K, peak power >100 mW and a slope efficiency of 48% (4.8% per stage) were observed in our gain guided lasers. The slope efficiency was strongly dependent on cavity length, and analysis of efficiency data suggests an internal differential quantum efficiency >1 and a loss coefficient greater than or equal to 100 cm(-1). (C) 1998 American Institute of Physics. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Kurtz, SR (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. NR 10 TC 19 Z9 20 U1 1 U2 2 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD APR 27 PY 1998 VL 72 IS 17 BP 2093 EP 2095 DI 10.1063/1.121286 PG 3 WC Physics, Applied SC Physics GA ZJ819 UT WOS:000073256700009 ER PT J AU Garcia, MM Jimenez, I Vazquez, L Gomez-Aleixandre, C Albella, JM Sanchez, O Terminello, LJ Himpsel, FJ AF Garcia, MM Jimenez, I Vazquez, L Gomez-Aleixandre, C Albella, JM Sanchez, O Terminello, LJ Himpsel, FJ TI X-ray absorption spectroscopy and atomic force microscopy study of bias-enhanced nucleation of diamond films SO APPLIED PHYSICS LETTERS LA English DT Article ID DEPOSITION; MECHANISM; SILICON AB The bias-enhanced nucleation of diamond on Si(100) has been studied by x-ray absorption near-edge spectroscopy (XANES) and atomic force microscopy, two techniques well suited to characterize nanometric crystallites. Diamond nuclei of similar to 15 nm are formed after 5 min of bias-enhanced treatment. The number of nuclei and its size increases with the time of application of the bias voltage. A nanocrystalline diamond film is attained after 20 min of bias-enhanced nucleation. At the initial nucleation stages, the Si substrate appears covered with diamond crystallites and graphite, without SiC being detected by XANES. (C) 1998 American Institute of Physics. C1 CSIC, Inst Ciencia Mat, Cantoblanco 28049, Madrid, Spain. Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. Univ Wisconsin, Dept Phys, Madison, WI 53706 USA. RP Garcia, MM (reprint author), CSIC, Inst Ciencia Mat, Cantoblanco 28049, Madrid, Spain. EM marpoza@icmm.csic.es RI VAZQUEZ, LUIS/A-1272-2009; Jimenez, Ignacio/F-7422-2010; Olga, Sanchez/C-4771-2011 OI VAZQUEZ, LUIS/0000-0001-6220-2810; Jimenez, Ignacio/0000-0001-5605-3185; Olga, Sanchez/0000-0001-8331-8214 NR 15 TC 37 Z9 39 U1 0 U2 2 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD APR 27 PY 1998 VL 72 IS 17 BP 2105 EP 2107 PG 3 WC Physics, Applied SC Physics GA ZJ819 UT WOS:000073256700013 ER PT J AU Mattila, T Bellaiche, L Wang, LW Zunger, A AF Mattila, T Bellaiche, L Wang, LW Zunger, A TI Electronic structure induced by lateral composition modulation in GaInAs alloys SO APPLIED PHYSICS LETTERS LA English DT Article ID LAYER ORDERING PROCESS; SHORT-PERIOD SUPERLATTICES; QUANTUM AB It has been recently shown that growth of [001]-oriented short period (AC)(n)/(BC)(n) vertical superlattices (n similar to 1-2) spontaneously creates a lateral composition modulation in the substrate plane ([110] direction), when wire-like AC-rich and BC-rich domains alternate with a period of similar to 100-200 Angstrom. This creates a new type of lattice structure with orthogonal [001] and [110] strain fields and compositional waves. Using a three-dimensional plane-wave pseudopotential approach, we study here the electronic properties of this type of structure in a GaInAs alloy, predicting valence band splittings into distinctly polarized components, a less than or equal to 100 meV band-gap reduction and strong, type I electron and hole confinement in the In-rich lateral channels. (C) 1998 American Institute of Physics. C1 Natl Renewable Energy Lab, Golden, CO 80401 USA. RP Mattila, T (reprint author), Natl Renewable Energy Lab, Golden, CO 80401 USA. RI Zunger, Alex/A-6733-2013 NR 19 TC 11 Z9 11 U1 0 U2 1 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD APR 27 PY 1998 VL 72 IS 17 BP 2144 EP 2146 DI 10.1063/1.121303 PG 3 WC Physics, Applied SC Physics GA ZJ819 UT WOS:000073256700026 ER PT J AU Gonis, A Schulthess, TC AF Gonis, A Schulthess, TC TI Systematic treatment of correlations in a generalized Hartree-Fock approximation SO JOURNAL OF PHYSICS-CONDENSED MATTER LA English DT Article AB The HartreeFock (HF) approximation is generalized to the study of n-particle states, taking correlation effects in interacting quantum-mechanical many-particle systems systematically into account. The case of n = 2 is developed explicitly. It is shown that the form of the HF equations remains essentially the same as in the usual formulation, but with appropriate interpretations of various parameters in terms of n-particle, rather than single; particle, states. We show results of calculations for model systems that illustrate the power of the method when compared to ordinary versions of the HF treatment. C1 Univ Calif Lawrence Livermore Natl Lab, Dept Chem & Mat Sci, Livermore, CA 94550 USA. RP Gonis, A (reprint author), Univ Calif Lawrence Livermore Natl Lab, Dept Chem & Mat Sci, L-268, Livermore, CA 94550 USA. NR 11 TC 4 Z9 4 U1 0 U2 1 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0953-8984 J9 J PHYS-CONDENS MAT JI J. Phys.-Condes. Matter PD APR 27 PY 1998 VL 10 IS 16 BP 3535 EP 3546 DI 10.1088/0953-8984/10/16/007 PG 12 WC Physics, Condensed Matter SC Physics GA ZL481 UT WOS:000073437200007 ER PT J AU Cheung, YKE Yin, Z AF Cheung, YKE Yin, Z TI Anomalies, branes, and currents SO NUCLEAR PHYSICS B LA English DT Article DE D-brane; anomaly; electro-magnetic duality; Calabi-Yau compactification and string theory ID GRAVITATIONAL ANOMALIES; CHIRAL ANOMALIES; INDEX THEOREM; GAUGE AB When a D-brane wraps around a cycle of a curved manifold, the twisting of its normal bundle can induce chiral asymmetry in its world-volume theory. We obtain the general form of the resulting anomalies for D-branes and their intersections. They are not cancelled among themselves, and the standard inflow mechanism does not apply at first sight because of their apparent lack of factorizability and the apparent vanishing of the corresponding inflow. We show, however, that after taking into consideration the effects of the non-trivial topology of the normal bundles, the anomalies can be transformed into factorized forms and precisely cancelled by finite inflow from the Chern-Simons actions for the D-branes as long as the latter are well defined. We then consider examples in type II compactifications where the twisting of the normal bundles occurs and calculate the changes in the induced Ramond-Ramond charges on the D-branes. (C) 1998 Elsevier Science B.V. C1 Princeton Univ, Dept Phys, Princeton, NJ 08544 USA. Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Cheung, YKE (reprint author), Princeton Univ, Dept Phys, Princeton, NJ 08544 USA. EM cheung@viper.princeton.edu; zyin@thsrv.lbl.gov NR 43 TC 138 Z9 138 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 27 PY 1998 VL 517 IS 1-3 BP 69 EP 91 DI 10.1016/S0550-3213(98)00115-1 PG 23 WC Physics, Particles & Fields SC Physics GA ZP333 UT WOS:000073741800004 ER PT J AU Jacob, J Espenson, JH Jensen, JH Gordon, MS AF Jacob, J Espenson, JH Jensen, JH Gordon, MS TI 1,3-transposition of allylic alcohols catalyzed by methyltrioxorhenium SO ORGANOMETALLICS LA English DT Article ID MAIN-GROUP ELEMENTS; HYDROGEN-PEROXIDE; METHYLRHENIUM TRIOXIDE; TRANSITION-METALS; MULTIPLE BONDS; BASIS-SETS; OXIDATION; FUNCTIONALITY; DEACTIVATION; EPOXIDATION AB Methyltrioxorhenium (MTO) catalyzes the 1,3-transposition of allylic alcohols to generate the more stable isomer at equilibrium. The direction of the equilibrium is largely decided by the nature of the OH group, i.e., whether it is primary, secondary, or tertiary. In the case of aliphatic allylic alcohols, tertiary is preferred to secondary which is preferred to primary. For aromatic allyl alcohols, the more conjugated isomer predominates largely at equilibrium. Oxygen-18 labeling showed that the OH groups of the parent and product are the same. The reaction is first order with respect to both allyl alcohol and MTO but strongly inhibited by traces of water. Theoretical calculations suggest the same results in the case of aliphatic allyl alcohols, although aromatic allyl alcohols do not follow the predictions. Studies of deuterium-labeled substrates show a large equilibrium isotope effect (K = 1.20 +/- 0.02). For isomeric allyl alcohols differing in the position of deuterium only, the isomer with the deuterium at the sp(3) center predominates at equilibrium. The effect of conjugation from a phenyl group appears to be less important since calculations suggest that the phenyl group is forced out of plane of the allylic pi system. C1 Iowa State Univ, Ames Lab, Ames, IA 50011 USA. Iowa State Univ, Dept Chem, Ames, IA 50011 USA. RP Espenson, JH (reprint author), Iowa State Univ, Ames Lab, Ames, IA 50011 USA. RI Jensen, Jan/G-4338-2010 OI Jensen, Jan/0000-0002-1465-1010 NR 47 TC 55 Z9 55 U1 0 U2 7 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0276-7333 J9 ORGANOMETALLICS JI Organometallics PD APR 27 PY 1998 VL 17 IS 9 BP 1835 EP 1840 DI 10.1021/om971115n PG 6 WC Chemistry, Inorganic & Nuclear; Chemistry, Organic SC Chemistry GA ZM001 UT WOS:000073494800030 ER PT J AU Behrens, BH Ford, WT Gritsan, A Krieg, H Roy, J Smith, JG Zhao, M Alexander, JP Baker, R Bebek, C Berger, BE Berkelman, K Bloom, K Boisvert, V Cassel, DG Crowcroft, DS Dickson, M von Dombrowski, S Drell, PS Ecklund, KM Ehrlich, R Foland, AD Gaidarev, P Gibbons, L Gittelman, B Gray, SW Hartill, DL Heltsley, BK Hopman, PI Kandaswamy, J Kim, PC Kreinick, DL Lee, T Liu, Y Mistry, NB Ng, CR Nordberg, E Ogg, M Patterson, JR Peterson, D Riley, D Soffer, A Valant-Spaight, B Ward, C Athanas, M Avery, P Jones, CD Lohner, M Patton, S Prescott, C Yelton, J Zheng, J Brandenburg, G Briere, RA Ershov, A Gao, YS Kim, DYJ Wilson, R Yamamoto, H Browder, TE Li, Y Rodriguez, JL Bergfeld, T Eisenstein, BI Ernst, J Gladding, GE Gollin, GD Hans, RM Johnson, E Karliner, I Marsh, MA Palmer, M Selen, M Thaler, JJ Edwards, KW Bellerive, A Janicek, R MacFarlane, DB Patel, PM Sadoff, AJ Ammar, R Baringer, P Bean, A Besson, D Coppage, D Darling, C Davis, R Kotov, S Kravchenko, I Kwak, N Zhou, L Anderson, S Kubota, Y Lee, SJ O'Neill, JJ Poling, R Riehle, T Smith, A Alam, MS Athar, SB Ling, Z Mahmood, AH Timm, S Wappler, F Anastassov, A Duboscq, JE Fujino, D Gan, KK Hart, T Honscheid, K Kagan, H Kass, R Lee, J Spencer, MB Sung, M Undrus, A Wolf, A Zoeller, MM Nemati, B Richichi, SJ Ross, WR Severini, H Skubic, P Bishai, M Fast, J Hinson, JW Menon, N Miller, DH Shibata, EI Shipsey, IPJ Yurko, M Glenn, S Kwon, Y Roberts, S Thorndike, EH Jessop, CP Lingel, K Marsiske, H Perl, ML Savinov, V Ugolini, D Wang, R Zhou, X Coan, TE Fadeyev, V Korolkov, I Maravin, Y Narsky, I Shelkov, V Staeck, J Stroynowski, R Volobouev, I Ye, J Artuso, M Azfar, F Efimov, A Goldberg, M He, D Kopp, S Moneti, GC Mountain, R Schuh, S Skwarnicki, T Stone, S Viehhauser, G Xing, X Bartelt, J Csorna, SE Jain, V McLean, KW Marka, S Godang, R Kinoshita, K Lai, IC Pomianowski, P Schrenk, S Bonvicini, G Cinabro, D Greene, R Perera, LP Zhou, GJ Chadha, M Chan, S Eigen, G Miller, JS O'Grady, C Schmidtler, M Urheim, J Weinstein, AJ Wurthwein, F Bliss, DW Masek, G Paar, HP Prell, S Sharma, V Asner, DM Gronberg, J Hill, TS Lange, DJ Morrison, RJ Nelson, HN Nelson, TK Roberts, D Ryd, A AF Behrens, BH Ford, WT Gritsan, A Krieg, H Roy, J Smith, JG Zhao, M Alexander, JP Baker, R Bebek, C Berger, BE Berkelman, K Bloom, K Boisvert, V Cassel, DG Crowcroft, DS Dickson, M von Dombrowski, S Drell, PS Ecklund, KM Ehrlich, R Foland, AD Gaidarev, P Gibbons, L Gittelman, B Gray, SW Hartill, DL Heltsley, BK Hopman, PI Kandaswamy, J Kim, PC Kreinick, DL Lee, T Liu, Y Mistry, NB Ng, CR Nordberg, E Ogg, M Patterson, JR Peterson, D Riley, D Soffer, A Valant-Spaight, B Ward, C Athanas, M Avery, P Jones, CD Lohner, M Patton, S Prescott, C Yelton, J Zheng, J Brandenburg, G Briere, RA Ershov, A Gao, YS Kim, DYJ Wilson, R Yamamoto, H Browder, TE Li, Y Rodriguez, JL Bergfeld, T Eisenstein, BI Ernst, J Gladding, GE Gollin, GD Hans, RM Johnson, E Karliner, I Marsh, MA Palmer, M Selen, M Thaler, JJ Edwards, KW Bellerive, A Janicek, R MacFarlane, DB Patel, PM Sadoff, AJ Ammar, R Baringer, P Bean, A Besson, D Coppage, D Darling, C Davis, R Kotov, S Kravchenko, I Kwak, N Zhou, L Anderson, S Kubota, Y Lee, SJ O'Neill, JJ Poling, R Riehle, T Smith, A Alam, MS Athar, SB Ling, Z Mahmood, AH Timm, S Wappler, F Anastassov, A Duboscq, JE Fujino, D Gan, KK Hart, T Honscheid, K Kagan, H Kass, R Lee, J Spencer, MB Sung, M Undrus, A Wolf, A Zoeller, MM Nemati, B Richichi, SJ Ross, WR Severini, H Skubic, P Bishai, M Fast, J Hinson, JW Menon, N Miller, DH Shibata, EI Shipsey, IPJ Yurko, M Glenn, S Kwon, Y Roberts, S Thorndike, EH Jessop, CP Lingel, K Marsiske, H Perl, ML Savinov, V Ugolini, D Wang, R Zhou, X Coan, TE Fadeyev, V Korolkov, I Maravin, Y Narsky, I Shelkov, V Staeck, J Stroynowski, R Volobouev, I Ye, J Artuso, M Azfar, F Efimov, A Goldberg, M He, D Kopp, S Moneti, GC Mountain, R Schuh, S Skwarnicki, T Stone, S Viehhauser, G Xing, X Bartelt, J Csorna, SE Jain, V McLean, KW Marka, S Godang, R Kinoshita, K Lai, IC Pomianowski, P Schrenk, S Bonvicini, G Cinabro, D Greene, R Perera, LP Zhou, GJ Chadha, M Chan, S Eigen, G Miller, JS O'Grady, C Schmidtler, M Urheim, J Weinstein, AJ Wurthwein, F Bliss, DW Masek, G Paar, HP Prell, S Sharma, V Asner, DM Gronberg, J Hill, TS Lange, DJ Morrison, RJ Nelson, HN Nelson, TK Roberts, D Ryd, A CA CLEO Collaboration TI Two-body B meson decays to eta and eta ': Observation of B ->eta ' K SO PHYSICAL REVIEW LETTERS LA English DT Article ID CP-VIOLATION; SEARCH; PHASES AB In a sample of 6.6 x 10(6) produced B mesons we have observed decays B --> eta'K, with branching fractions B(B+ --> eta'K+)= (6.5(-1.4)(+1.5) +/- 0.9) X 10(-5) and B(B-0 --> eta'K-0) = (4.7(-2.0)(+2.7) +/- 0.9) X 10(-5). We have searched with comparable sensitivity for 17 related decays to final states containing an eta or eta' meson accompanied by a single particle or low-lying resonance. Our upper limits for these constrain theoretical interpretations of the B --> eta'K signal. C1 Univ Colorado, Boulder, CO 80309 USA. Cornell Univ, Ithaca, NY 14853 USA. Univ Florida, Gainesville, FL 32611 USA. Harvard Univ, Cambridge, MA 02138 USA. Univ Hawaii, Honolulu, HI 96822 USA. Univ Illinois, Urbana, IL 61801 USA. Carleton Univ, Ottawa, ON K1S 5B6, Canada. McGill Univ, Montreal, PQ H3A 2T8, Canada. Ithaca Coll, Ithaca, NY 14850 USA. Univ Kansas, Lawrence, KS 66045 USA. Univ Minnesota, Minneapolis, MN 55455 USA. SUNY Albany, Albany, NY 12222 USA. Ohio State Univ, Columbus, OH 43210 USA. Univ Oklahoma, Norman, OK 73019 USA. Purdue Univ, W Lafayette, IN 47907 USA. Univ Rochester, Rochester, NY 14627 USA. Stanford Univ, Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. So Methodist Univ, Dallas, TX 75275 USA. Syracuse Univ, Syracuse, NY 13244 USA. Vanderbilt Univ, Nashville, TN 37235 USA. Virginia Polytech Inst & State Univ, Blacksburg, VA 24061 USA. Wayne State Univ, Detroit, MI 48202 USA. CALTECH, Pasadena, CA 91125 USA. Univ Calif San Diego, La Jolla, CA 92093 USA. Univ Calif Santa Barbara, Santa Barbara, CA 93106 USA. Univ Texas, Austin, TX 78712 USA. Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. BINP, RU-630090 Novosibirsk, Russia. Yonsei Univ, Seoul 120749, South Korea. Brookhaven Natl Lab, Upton, NY 11973 USA. RP Behrens, BH (reprint author), Univ Colorado, Boulder, CO 80309 USA. RI Briere, Roy/N-7819-2014 OI Briere, Roy/0000-0001-5229-1039 NR 32 TC 94 Z9 94 U1 1 U2 2 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD APR 27 PY 1998 VL 80 IS 17 BP 3710 EP 3714 DI 10.1103/PhysRevLett.80.3710 PG 5 WC Physics, Multidisciplinary SC Physics GA ZJ826 UT WOS:000073257600010 ER PT J AU Hawker, EA Awes, TC Beddo, ME Brown, CN Bush, JD Carey, TA Chang, TH Cooper, WE Gagliardi, CA Garvey, GT Geesaman, DF He, XC Isenhower, LD Kaufman, SB Kaplan, DM Kirk, PN Koetke, DD Kyle, G Lee, DM Lee, WM Leitch, MJ Makins, N McGaughey, PL Moss, JM Mueller, BA Nord, PM Park, BK Papavassiliou, V Peng, JC Petitt, G Reimer, PE Sadler, ME Selden, J Stankus, PW Sondheim, WE Thompson, TN Towell, RS Tribble, RE Vasiliev, MA Wang, YC Wang, ZF Webb, JC Willis, JL Wise, DK Young, GR AF Hawker, EA Awes, TC Beddo, ME Brown, CN Bush, JD Carey, TA Chang, TH Cooper, WE Gagliardi, CA Garvey, GT Geesaman, DF He, XC Isenhower, LD Kaufman, SB Kaplan, DM Kirk, PN Koetke, DD Kyle, G Lee, DM Lee, WM Leitch, MJ Makins, N McGaughey, PL Moss, JM Mueller, BA Nord, PM Park, BK Papavassiliou, V Peng, JC Petitt, G Reimer, PE Sadler, ME Selden, J Stankus, PW Sondheim, WE Thompson, TN Towell, RS Tribble, RE Vasiliev, MA Wang, YC Wang, ZF Webb, JC Willis, JL Wise, DK Young, GR TI Measurement of the light antiquark flavor asymmetry in the nucleon sea SO PHYSICAL REVIEW LETTERS LA English DT Article ID DRELL-YAN PROCESS; NN FORM-FACTOR; SYMMETRY-BREAKING; QUARK SEA; DIMUON PRODUCTION; GOTTFRIED SUM; DISTRIBUTIONS; LIMIT AB A precise measurement of the ratio of Drell-Yan yields from an 800 GeV/c proton beam incident on hydrogen and deuterium targets is reported. Over 140 000 Drell-Yan muon pairs with dimuon mass Mmu+mu- greater than or equal to 4.5 GeV/c(2) were recorded. From these data, the ratio of antidown ((d) over bar) to antiup ((u) over bar) quark distributions in the proton sea is determined over a wide range in Bjorken x. A strong x dependence is observed in the ratio (d) over bar/(u) over bar, showing substantial enhancement of (d) over bar with respect to (u) over bar for x < 0.2. This result is in fair agreement with recent parton distribution parametrizations of the sea. For x > 0.2, the observed (d) over bar/(u) over bar ratio is much nearer unity than given by the parametrizations. C1 Abilene Christian Univ, Abilene, TX 79699 USA. Fermilab Natl Accelerator Lab, Batavia, IL 60510 USA. Georgia State Univ, Atlanta, GA 30303 USA. IIT, Chicago, IL 60616 USA. Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Louisiana State Univ, Baton Rouge, LA 70803 USA. New Mexico State Univ, Las Cruces, NM 88003 USA. Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. Texas A&M Univ, College Stn, TX 77843 USA. Valparaiso Univ, Valparaiso, IN 46383 USA. Argonne Natl Lab, Argonne, IL 60439 USA. Univ Texas, Austin, TX 78712 USA. RP Hawker, EA (reprint author), Abilene Christian Univ, Abilene, TX 79699 USA. RI Reimer, Paul/E-2223-2013 NR 24 TC 325 Z9 325 U1 0 U2 6 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 APR 27 PY 1998 VL 80 IS 17 BP 3715 EP 3718 DI 10.1103/PhysRevLett.80.3715 PG 4 WC Physics, Multidisciplinary SC Physics GA ZJ826 UT WOS:000073257600011 ER PT J AU Rangarajan, G Habib, S Ryne, RD AF Rangarajan, G Habib, S Ryne, RD TI Lyapunov exponents without rescaling and reorthogonalization SO PHYSICAL REVIEW LETTERS LA English DT Article ID TRANSPORT-COEFFICIENTS; SYSTEMS; CHAOS AB We present a new method for the computation of Lyapunov exponents utilizing representations of orthogonal matrices applied to decompositions of M or M (M) over tilde where M is the tangent map. This method uses a minimal set of variables, does not require renormalization or reorthogonalization, can be used to efficiently compute partial Lyapunov spectra, and does not break down when the Lyapunov spectrum is degenerate. C1 Indian Inst Sci, Dept Math, Bangalore 560012, Karnataka, India. Indian Inst Sci, Ctr Theoret Studies, Bangalore 560012, Karnataka, India. Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. Los Alamos Natl Lab, LANSCE Div, LANSCE 1, Los Alamos, NM 87545 USA. RP Rangarajan, G (reprint author), Indian Inst Sci, Dept Math, Bangalore 560012, Karnataka, India. EM rangaraj@math.iisc.ernet.in; habib@lanl.gov; ryne@lanl.gov NR 22 TC 49 Z9 49 U1 1 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 APR 27 PY 1998 VL 80 IS 17 BP 3747 EP 3750 DI 10.1103/PhysRevLett.80.3747 PG 4 WC Physics, Multidisciplinary SC Physics GA ZJ826 UT WOS:000073257600019 ER PT J AU Weir, ST Chandler, EA Goodwin, BT AF Weir, ST Chandler, EA Goodwin, BT TI Rayleigh-Taylor instability experiments examining feedthrough growth in an incompressible, convergent geometry SO PHYSICAL REVIEW LETTERS LA English DT Article ID FUSION AB We have performed Rayleigh-Taylor instability and feedthrough growth experiments in a 2D cylindrically convergent geometry by imploding gelatin cylinders with high-pressure gases. Instability growth was seeded by fabricating sinusoidal undulations on the outer surfaces of the cylinders, which were then observed during implosion with high-speed framing cameras. These experiments are the first to study feedthrough perturbation growth in an incompressible, convergent geometry. We compare the results to small-amplitude perturbation analysis and to a recent radiation-drive feedthrough experiment. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. RP Weir, ST (reprint author), Univ Calif Lawrence Livermore Natl Lab, POB 808, Livermore, CA 94551 USA. RI Weir, Samuel/H-5046-2012 NR 18 TC 20 Z9 25 U1 0 U2 1 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD APR 27 PY 1998 VL 80 IS 17 BP 3763 EP 3766 DI 10.1103/PhysRevLett.80.3763 PG 4 WC Physics, Multidisciplinary SC Physics GA ZJ826 UT WOS:000073257600023 ER PT J AU van Buuren, T Dinh, LN Chase, LL Siekhaus, WJ Terminello, LJ AF van Buuren, T Dinh, LN Chase, LL Siekhaus, WJ Terminello, LJ TI Changes in the electronic properties of Si nanocrystals as a function of particle size SO PHYSICAL REVIEW LETTERS LA English DT Article ID POROUS SILICON; CLUSTERS; SURFACES; CHEMISORPTION; LUMINESCENCE; SPECTROSCOPY; CONFINEMENT; ABSORPTION; MECHANISM; SI(111) AB X-ray absorption and photoemission spectra have been used to measure the band edges of silicon nanocrystals with average diameters ranging from 1 to 5 nm. We compare the experimentally measured band edges to recent electronic structure calculations and find that the experimentally measured band gap is smaller than that predicted by theory. C1 Univ Calif Lawrence Livermore Natl Lab, Dept Chem & Mat Sci, Livermore, CA 94550 USA. RP van Buuren, T (reprint author), Univ Calif Lawrence Livermore Natl Lab, Dept Chem & Mat Sci, Livermore, CA 94550 USA. NR 22 TC 322 Z9 324 U1 2 U2 41 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD APR 27 PY 1998 VL 80 IS 17 BP 3803 EP 3806 DI 10.1103/PhysRevLett.80.3803 PG 4 WC Physics, Multidisciplinary SC Physics GA ZJ826 UT WOS:000073257600033 ER PT J AU Louca, D Kwei, GH Mitchell, JF AF Louca, D Kwei, GH Mitchell, JF TI Local lattice effects in the layered manganite La1.4Sr1.6Mn2O7 SO PHYSICAL REVIEW LETTERS LA English DT Article ID DOPED LAMNO3; MAGNETORESISTANCE; RESISTIVITY; DISTORTION; OXIDES AB The pair density function analysis of pulsed neutron diffraction data for the two-layer manganite La1.4Sr1.6Mn2O7 indicates the presence of a large local Jahn-Teller (JT) distortion of comparable magnitude to that found in the perovskites, while the crystallographic structure shows a very small JT effect. A model that includes JT displacements provides a better representation of the local structure than the existing crystallographic one. While the local distortion is reduced at lower temperatures its change corresponds more to the increase in the transport in the ab plane than to the magnetic transition, reflecting the 2D nature of the crystal. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Argonne Natl Lab, Argonne, IL 60439 USA. RP Louca, D (reprint author), Univ Calif Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. NR 33 TC 43 Z9 43 U1 0 U2 7 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD APR 27 PY 1998 VL 80 IS 17 BP 3811 EP 3814 DI 10.1103/PhysRevLett.80.3811 PG 4 WC Physics, Multidisciplinary SC Physics GA ZJ826 UT WOS:000073257600035 ER PT J AU Schmalian, J Pines, D Stojkovic, B AF Schmalian, J Pines, D Stojkovic, B TI Weak pseudogap behavior in the underdoped cuprate superconductors SO PHYSICAL REVIEW LETTERS LA English DT Article ID HIGH-TEMPERATURE SUPERCONDUCTIVITY; ANTIFERROMAGNETIC FERMI-LIQUID; NORMAL-STATE; BI2SR2CACU2O8+DELTA; YBA2CU3O7; OXIDES; GAP AB We report on a novel solution of the nearly antiferromagnetic (AF) spin fermion model in the limit pi T much greater than omega(sf), which demonstrates that the broad high energy features found in angular resolved photoemission spectroscopy measurements of the spectral density of the underdoped cuprates are determined by strong (AF) correlations and precursor effects of a spin density wave state. We show that the onset temperature, T-cr, of weak pseudogap behavior is determined by the strength, xi, of the (AF) correlations, and obtain the generic changes in low frequency magnetic behavior seen in NMR experiments with xi(T-cr) approximate to 2, confirming the Barzykin and Pines crossover criterion. C1 Univ Illinois, Loomis Lab Phys, Urbana, IL 61801 USA. Univ Calif Los Alamos Natl Lab, Ctr Nonlinear Studies, Los Alamos, NM 87545 USA. RP Schmalian, J (reprint author), Univ Illinois, Loomis Lab Phys, 1110 W Green St, Urbana, IL 61801 USA. RI Schmalian, Joerg/H-2313-2011 NR 22 TC 165 Z9 165 U1 0 U2 6 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD APR 27 PY 1998 VL 80 IS 17 BP 3839 EP 3842 DI 10.1103/PhysRevLett.80.3839 PG 4 WC Physics, Multidisciplinary SC Physics GA ZJ826 UT WOS:000073257600042 ER PT J AU Niedermayer, C Bernhard, C Blasius, T Golnik, A Moodenbaugh, A Budnick, JI AF Niedermayer, C Bernhard, C Blasius, T Golnik, A Moodenbaugh, A Budnick, JI TI Common phase diagram for antiferromagnetism in La2-xSrxCuO4 and Y1-xCaxBa2Cu3O6 as seen by muon spin rotation SO PHYSICAL REVIEW LETTERS LA English DT Article ID LIGHTLY DOPED LA2-XSRXCUO4; SUPERCONDUCTING PROPERTIES; LA-139 NQR; LA2CUO4+DELTA; RELAXATION; SEPARATION; SR; LA2-XBAXCUO4; TRANSITION; BEHAVIOR AB By zero field muon spin rotation we studied the antiferromagnetic correlations in the single layer system La2-xSrxCuO4 and the bilayer system Y1-xCaxBa2Cu3O6. We observe a common phase diagram as a function of hole doping per plane with two distinct transitions in the magnetic ground state. The first transition marks the border between the 3D antiferromagnetic state and a disordered state with short ranged correlations. The second transition marks a distinct change in the magnetic correlations at the onset of superconductivity. C1 Univ Konstanz, Fak Phys, D-78434 Constance, Germany. Max Planck Inst Festkorperforsch, D-70569 Stuttgart, Germany. Univ Warsaw, Inst Expt Phys, PL-00681 Warsaw, Poland. Brookhaven Natl Lab, Dept Appl Sci, Upton, NY 11977 USA. Univ Connecticut, Dept Phys, Storrs, CT 06269 USA. Univ Connecticut, Inst Sci Mat, Storrs, CT 06269 USA. RP Niedermayer, C (reprint author), Univ Konstanz, Fak Phys, D-78434 Constance, Germany. RI Niedermayer, Christof/K-4436-2014; OI Moodenbaugh, Arnold/0000-0002-3415-6762 NR 26 TC 329 Z9 329 U1 3 U2 25 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD APR 27 PY 1998 VL 80 IS 17 BP 3843 EP 3846 DI 10.1103/PhysRevLett.80.3843 PG 4 WC Physics, Multidisciplinary SC Physics GA ZJ826 UT WOS:000073257600043 ER PT J AU Ortiz, G Wan, Y Phillips, P AF Ortiz, G Wan, Y Phillips, P TI Comment on "Pair tunneling in semiconductor quantum dots" - Reply SO PHYSICAL REVIEW LETTERS LA English DT Article C1 Univ Calif Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. Univ Illinois, Loomis Lab Phys, Urbana, IL 61801 USA. RP Ortiz, G (reprint author), Univ Calif Los Alamos Natl Lab, Div Theoret, POB 1663, Los Alamos, NM 87545 USA. NR 4 TC 0 Z9 0 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD APR 27 PY 1998 VL 80 IS 17 BP 3885 EP 3885 DI 10.1103/PhysRevLett.80.3885 PG 1 WC Physics, Multidisciplinary SC Physics GA ZJ826 UT WOS:000073257600055 ER PT J AU Brehm, J Worley, PH Madhukar, M AF Brehm, J Worley, PH Madhukar, M TI Performance modeling for SPMD message-passing programs SO CONCURRENCY-PRACTICE AND EXPERIENCE LA English DT Article ID SPECTRAL TRANSFORM METHOD; PARALLEL PROGRAMS; SCALABILITY AB Today's massively parallel machines are typically message-passing systems consisting of hundreds or thousands of processors. Implementing parallel applications efficiently in this environment is a challenging task, and poor parallel design decisions can be expensive to correct. Tools and techniques that allow the fast and accurate evaluation of different parallelization strategies would significantly improve the productivity of application developers and increase throughput on parallel architectures. This paper investigates one of the major issues in building tools to compare parallelization strategies: determining what type of performance models of the application code and of the computer system are sufficient for a fast and accurate comparison of different strategies. The paper is built around a case study employing the performance prediction tool (PerPreT) to predict performance of the parallel spectral transform shallow water model code (PSTSWM) on the Intel Paragon. PSTSWM is a parallel application code that was designed to evaluate different parallel strategies for the spectral transform method as it is used in climate modeling and weather forecasting, Multiple parallel algorithms and algorithm variants are embedded in the code. PerPreT uses a relatively simple algebraic model to predict execution time for SPMD (single program multiple data) parallel applications. Applications are modeled through parameterized formulae for communication and computation, where the parameters include the problem size, the number of processors used to execute the program, and system characteristics (e,g, setup times for communication, link bandwidth and sustained computing performance per processor). In this paper we describe performance models that predict the performance of the different algorithms in PSTSWM accurately enough to allow them to be compared, establishing the feasibility of such a demanding application of performance modeling, We also discuss issues in generating and validating the performance models, emphasizing the practical importance of tools such as PerPreT in such studies. (C) 1998 John Wiley & Sons, Ltd. C1 Univ Hannover, Inst Rechnerstrukturen & Betriebssyst, D-30159 Hannover, Germany. Oak Ridge Natl Lab, Math Sci Sect, Oak Ridge, TN 37831 USA. Vanderbilt Univ, Dept Comp Sci, Nashville, TN 37235 USA. EM worleyph@ornl.gov NR 34 TC 3 Z9 3 U1 0 U2 0 PU JOHN WILEY & SONS LTD PI W SUSSEX PA BAFFINS LANE CHICHESTER, W SUSSEX PO19 1UD, ENGLAND SN 1040-3108 J9 CONCURRENCY-PRACT EX JI Concurrency-Pract. Exp. PD APR 25 PY 1998 VL 10 IS 5 BP 333 EP 357 DI 10.1002/(SICI)1096-9128(19980425)10:5<333::AID-CPE321>3.0.CO;2-X PG 25 WC Computer Science, Software Engineering; Computer Science, Theory & Methods SC Computer Science GA ZL460 UT WOS:000073435100001 ER PT J AU Worley, PH Robinson, AC Mackay, DR Barragy, EJ AF Worley, PH Robinson, AC Mackay, DR Barragy, EJ TI A study of application sensitivity to variation in message-passing latency and bandwidth SO CONCURRENCY-PRACTICE AND EXPERIENCE LA English DT Article ID MODELS; PERFORMANCE; EQUATIONS; PROGRAMS; CODE AB This study measures the effects of changes In message latency and bandwidth for production-level codes on a current generation tightly coupled MPP, the Intel Paragon. Messages are sent multiple times to study the application sensitivity to variations in bandwidth and latency. This method preserves the effects of contention on the interconnection network. Two applications are studied: PCTH, a shock physics code developed at Sandia National Laboratories; and PSTSWM, a spectral shallow water code developed at Oak Ridge National Laboratory and Argonne National Laboratory These codes ape significant in that PCTH is a 'full physics' application code in production use, while PSTSWM serves as a parallel algorithm test bed and benchmark for production codes used in atmospheric modeling. They are also significant in that the message-passing behavior differs significantly between the two codes, each representing an important class of scientific message passing applications, (C) 1998 John Wiley & Sons, Ltd. C1 Oak Ridge Natl Lab, Math Sci Sect, Oak Ridge, TN 37831 USA. Sandia Natl Labs, Albuquerque, NM 87185 USA. Intel Corp, Beaverton, OR 97006 USA. EM worleyph@ornl.gov NR 23 TC 3 Z9 3 U1 0 U2 0 PU JOHN WILEY & SONS LTD PI W SUSSEX PA BAFFINS LANE CHICHESTER, W SUSSEX PO19 1UD, ENGLAND SN 1040-3108 J9 CONCURRENCY-PRACT EX JI Concurrency-Pract. Exp. PD APR 25 PY 1998 VL 10 IS 5 BP 387 EP 406 DI 10.1002/(SICI)1096-9128(19980425)10:5<387::AID-CPE324>3.0.CO;2-7 PG 20 WC Computer Science, Software Engineering; Computer Science, Theory & Methods SC Computer Science GA ZL460 UT WOS:000073435100003 ER PT J AU Zhou, HB Geist, A AF Zhou, HB Geist, A TI LPVM: a step towards multithread PVM SO CONCURRENCY-PRACTICE AND EXPERIENCE LA English DT Article AB LPVM (lightweight-process PVM) is an experimental PVM version that supports the use of lightweight processes or threads as the basic unit of parallelism. It was designed to study potential performance improvements and implementation issues required by multithread message-passing systems. The current version of LPVM was implemented on SMPs (shared memory processors) using POSIX threads and is designed to be thread safe. Initial test results on a SUN SMP are compared with the performance of standard PVM, Task spawning is an order of magnitude faster in LPVM, but message-passing between threads using shared memory was found to be slower than standard PVM due to overheads in getting and releasing shared memory locks. (C) 1998 John Wiley & Sons, Ltd. C1 Oak Ridge Natl Lab, Math Sci Sect, Oak Ridge, TN 37831 USA. NR 13 TC 5 Z9 5 U1 0 U2 0 PU JOHN WILEY & SONS LTD PI W SUSSEX PA BAFFINS LANE CHICHESTER, W SUSSEX PO19 1UD, ENGLAND SN 1040-3108 J9 CONCURRENCY-PRACT EX JI Concurrency-Pract. Exp. PD APR 25 PY 1998 VL 10 IS 5 BP 407 EP 416 DI 10.1002/(SICI)1096-9128(19980425)10:5<407::AID-CPE326>3.0.CO;2-6 PG 10 WC Computer Science, Software Engineering; Computer Science, Theory & Methods SC Computer Science GA ZL460 UT WOS:000073435100004 ER PT J AU Abbott, JR Graham, AL Mondy, LA Brenner, H AF Abbott, JR Graham, AL Mondy, LA Brenner, H TI Dispersion of a ball settling through a quiescent neutrally buoyant suspension SO JOURNAL OF FLUID MECHANICS LA English DT Article ID CONCENTRATED SUSPENSIONS; SELF-DIFFUSION; HYDRODYNAMIC DIFFUSION; VELOCITY FLUCTUATIONS; PARTICLE MIGRATION; COUETTE-FLOW; SPHERES; RHEOMETRY; VISCOSITY; RODS AB Individual falling balls were allowed to settle through otherwise quiescent well-mixed suspensions of non-colloidal neutrally buoyant spheres dispersed in a Newtonian liquid. Balls were tracked in three dimensions to determine the variances in their positions about a mean uniform vertical settling path. The primary experimental parameters investigated were the size of the falling ball and the volume fraction and size of the suspended particles. Unlike the horizontal variances, the vertical variances were found to be affected by short-time deterministic behaviour relating to the instantaneous local configurational arrangement of the suspended particles. For sufficiently long intervals between successive observations, the trajectories of the balls were observed to disperse about their mean settling paths in a random manner. This points to the existence of a Gaussian hydrodynamic dispersivity that characterizes the linear temporal growth of the variance in the position of a falling ball. The functional dependence of these horizontal and vertical dispersivities upon the parameters investigated was established. The dispersivity dyadic was observed to be transversely isotropic with respect to the direction of gravity, with the vertical component at least 25 times larger than the horizontal component. The vertical dispersivity (D) over cap(v) (made dimensionless with the diameter of the suspended spheres and the mean settling velocity) was observed to decrease with increasing falling ball diameter, but to decrease less rapidly with concentration than theoretically predicted for very dilute suspensions; moreover, for falling balls equal in size to the suspended spheres, (D) over cap(v) increased linearly with increasing volume fraction phi of suspended solids. In addition to the above experiments performed on suspensions of spheres, previously published settling-velocity data on the fall of balls through neutrally buoyant suspensions of rods possessing an aspect ratio of 20 were re-analysed, and vertical dispersivities calculated therefrom. (These data, taken by several of the present investigators in conjunction with other researchers, had only been grossly analysed in prior publications to extract the mean settling velocity of the ball, no attempt having been made at the time to extract dispersivity data too.) The resulting vertical dispersivities, when rendered dimensionless with the rod length and mean settling velocity, showed no statistically significant dependence upon the falling-ball diameter; moreover, all other things being equal, these dispersivities were observed to increase with increasing rod concentration. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Sandia Natl Labs, Albuquerque, NM 87185 USA. MIT, Cambridge, MA 02139 USA. RP Abbott, JR (reprint author), Univ Calif Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. NR 28 TC 7 Z9 7 U1 2 U2 5 PU CAMBRIDGE UNIV PRESS PI NEW YORK PA 40 WEST 20TH STREET, NEW YORK, NY 10011-4211 USA SN 0022-1120 J9 J FLUID MECH JI J. Fluid Mech. PD APR 25 PY 1998 VL 361 BP 309 EP 331 DI 10.1017/S0022112098008763 PG 23 WC Mechanics; Physics, Fluids & Plasmas SC Mechanics; Physics GA ZQ776 UT WOS:000073901900013 ER PT J AU Bhugra, B Smolarek, TA Lynch, RA Meloni, AM Sandberg, AA Deaven, L Menon, AG AF Bhugra, B Smolarek, TA Lynch, RA Meloni, AM Sandberg, AA Deaven, L Menon, AG TI Cloning of a breakpoint cluster region on chromosome 14 in uterine leiomyoma SO CANCER LETTERS LA English DT Article DE breakpoint cluster region; chromosome 14; uterine leiomyoma ID PULMONARY HAMARTOMAS; CELL-CARCINOMA; HMGI-C; ABNORMALITIES; T(12-14); LEUKEMIA AB A recurrent reciprocal chromosomal translocation, t(12;14)(q15;q24) is frequently observed in uterine leiomyoma. Chromosome 12 breakpoints have been shown to occur in a region of approximately 150 kb that contains the gene for a high mobility group protein (HMGI-C). The breakpoint region on chromosome 14 has not been precisely defined. We have generated a contig of overlapping yeast artificial chromosome (YAC) clones approximately 3 Mb in size. Fluorescence in situ hybridization (FISH) analysis showed that this contig spanned the t(12;14) breakpoints in three uterine leiomyomas and that the breakpoints in these tumors occurred within a 1 Mb region. A 30 kb cosmid spanning one of the breakpoints was isolated to set the stage for identifying regions on chromosome 14 that may cause this region to be a preferential site for chromosomal translocation. Published by Elsevier Science Ireland Ltd. C1 Univ Cincinnati, Coll Med, Dept Mol Genet Biochem & Microbiol, Cincinnati, OH 45267 USA. Univ Utah, Salt Lake City, UT 84112 USA. Genzyme Genet, Scottsdale, AZ 85251 USA. Univ Calif Los Alamos Natl Lab, Ctr Human Genome Studies, Los Alamos, NM 87545 USA. RP Bhugra, B (reprint author), Univ Cincinnati, Coll Med, Dept Internal Med, Div Infect Dis, Cincinnati, OH 45267 USA. FU NCI NIH HHS [CA67315] NR 23 TC 8 Z9 9 U1 0 U2 0 PU ELSEVIER SCI IRELAND LTD PI CLARE PA CUSTOMER RELATIONS MANAGER, BAY 15, SHANNON INDUSTRIAL ESTATE CO, CLARE, IRELAND SN 0304-3835 J9 CANCER LETT JI Cancer Lett. PD APR 24 PY 1998 VL 126 IS 2 BP 119 EP 126 DI 10.1016/S0304-3835(97)00478-3 PG 8 WC Oncology SC Oncology GA ZH178 UT WOS:000073080600001 PM 9585056 ER PT J AU Griffin, GD Miller, EJ Creekmore, AL Gailey, PC AF Griffin, GD Miller, EJ Creekmore, AL Gailey, PC TI Responses to hormones in an estrogen-responsive subline of MCF-7 cells. SO FASEB JOURNAL LA English DT Meeting Abstract C1 Oak Ridge Natl Lab, Oak Ridge, TN USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU FEDERATION AMER SOC EXP BIOL PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814-3998 USA SN 0892-6638 J9 FASEB J JI Faseb J. PD APR 24 PY 1998 VL 12 IS 8 SU S MA 848 BP A1457 EP A1457 PG 1 WC Biochemistry & Molecular Biology; Biology; Cell Biology SC Biochemistry & Molecular Biology; Life Sciences & Biomedicine - Other Topics; Cell Biology GA 260QN UT WOS:000083961501002 ER PT J AU Jung, CH Lu, TYS Larimer, FW AF Jung, CH Lu, TYS Larimer, FW TI Heterologous expression and characterization of ribose-5-phosphate isomerase from spinach SO FASEB JOURNAL LA English DT Meeting Abstract C1 Oak Ridge Natl Lab, Div Life Sci, Prot Engn Program, Oak Ridge, TN USA. Univ Tennessee, Oak Ridge Grad Sch Biomed Sci, Oak Ridge, TN 37830 USA. NR 0 TC 0 Z9 0 U1 0 U2 1 PU FEDERATION AMER SOC EXP BIOL PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814-3998 USA SN 0892-6638 J9 FASEB J JI Faseb J. PD APR 24 PY 1998 VL 12 IS 8 SU S MA 807 BP A1450 EP A1450 PG 1 WC Biochemistry & Molecular Biology; Biology; Cell Biology SC Biochemistry & Molecular Biology; Life Sciences & Biomedicine - Other Topics; Cell Biology GA 260QN UT WOS:000083961500961 ER PT J AU Karasawa, K Lee, TC AF Karasawa, K Lee, TC TI Purification of platelet-activating factor(PAF)-dependent transacetylases from rat kidney membrane SO FASEB JOURNAL LA English DT Meeting Abstract C1 Oak Ridge Associated Univ, Oak Ridge, TN USA. NR 0 TC 1 Z9 1 U1 0 U2 0 PU FEDERATION AMER SOC EXP BIOL PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814-3998 USA SN 0892-6638 J9 FASEB J JI Faseb J. PD APR 24 PY 1998 VL 12 IS 8 SU S MA 404 BP A1380 EP A1380 PG 1 WC Biochemistry & Molecular Biology; Biology; Cell Biology SC Biochemistry & Molecular Biology; Life Sciences & Biomedicine - Other Topics; Cell Biology GA 260QN UT WOS:000083961500558 ER PT J AU Kim, KK Kim, R Kim, SH AF Kim, KK Kim, R Kim, SH TI Three-dimensional structure of a small heat shock protein homolog from Methanococcus jannaschii, an archaeon SO FASEB JOURNAL LA English DT Meeting Abstract C1 Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Dept Biol Struct, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. NR 0 TC 2 Z9 2 U1 0 U2 0 PU FEDERATION AMER SOC EXP BIOL PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814-3998 USA SN 0892-6638 J9 FASEB J JI Faseb J. PD APR 24 PY 1998 VL 12 IS 8 SU S MA 118 BP A1329 EP A1329 PG 1 WC Biochemistry & Molecular Biology; Biology; Cell Biology SC Biochemistry & Molecular Biology; Life Sciences & Biomedicine - Other Topics; Cell Biology GA 260QN UT WOS:000083961500270 ER PT J AU Kim, SH Zhang, Z Huang, LS Chi, YI Kim, KK Hung, LW Berry, EA AF Kim, SH Zhang, Z Huang, LS Chi, YI Kim, KK Hung, LW Berry, EA TI Dynamic structure of the mitrochondrial cytochrome bc(1) complex. SO FASEB JOURNAL LA English DT Meeting Abstract C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. Univ Calif Berkeley, Grad Grp Biophys, Berkeley, CA 94720 USA. NR 0 TC 0 Z9 0 U1 1 U2 2 PU FEDERATION AMER SOC EXP BIOL PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814-3998 USA SN 0892-6638 J9 FASEB J JI Faseb J. PD APR 24 PY 1998 VL 12 IS 8 SU S MA 17 BP A1309 EP A1309 PG 1 WC Biochemistry & Molecular Biology; Biology; Cell Biology SC Biochemistry & Molecular Biology; Life Sciences & Biomedicine - Other Topics; Cell Biology GA 260QN UT WOS:000083961500171 ER PT J AU Niyogi, SK Nandagopal, K Murray, MB Puddicombe, SM Richter, A Davies, DE Reddy, CC Lauffenburger, DA AF Niyogi, SK Nandagopal, K Murray, MB Puddicombe, SM Richter, A Davies, DE Reddy, CC Lauffenburger, DA TI Use of engineered variants of human epidermal growth factor (hEGF) in elucidating growth signaling. SO FASEB JOURNAL LA English DT Meeting Abstract C1 Oak Ridge Natl Lab, Div Life Sci, Oak Ridge, TN 37831 USA. Southampton Gen Hosp, Med Oncol Unit, Southampton SO16 6YD, Hants, England. MIT, Ctr Biomed Engn, Cambridge, MA 02139 USA. RI Davies, Donna/H-2993-2012 NR 0 TC 0 Z9 0 U1 0 U2 1 PU FEDERATION AMER SOC EXP BIOL PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814-3998 USA SN 0892-6638 J9 FASEB J JI Faseb J. PD APR 24 PY 1998 VL 12 IS 8 SU S MA 188 BP A1342 EP A1342 PG 1 WC Biochemistry & Molecular Biology; Biology; Cell Biology SC Biochemistry & Molecular Biology; Life Sciences & Biomedicine - Other Topics; Cell Biology GA 260QN UT WOS:000083961500340 ER PT J AU Qiu, X Sebok, A Tigvi, G Lee, TC AF Qiu, X Sebok, A Tigvi, G Lee, TC TI Induction of platelet-activating factor (PAF): Sphingosine transacetylase activity (C-2-ceramide forming enzyme) by nerve growth factor (NGF) and lysophosphatidic acid (LPA). SO FASEB JOURNAL LA English DT Meeting Abstract C1 Oak Ridge Associated Univ, Oak Ridge, TN USA. Univ Tennessee, Memphis, TN USA. NR 0 TC 1 Z9 1 U1 0 U2 0 PU FEDERATION AMER SOC EXP BIOL PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814-3998 USA SN 0892-6638 J9 FASEB J JI Faseb J. PD APR 24 PY 1998 VL 12 IS 8 SU S MA 401 BP A1379 EP A1379 PG 1 WC Biochemistry & Molecular Biology; Biology; Cell Biology SC Biochemistry & Molecular Biology; Life Sciences & Biomedicine - Other Topics; Cell Biology GA 260QN UT WOS:000083961500556 ER PT J AU Tanaka, K Ohta, K Haddad, PR Fritz, JS AF Tanaka, K Ohta, K Haddad, PR Fritz, JS TI Ion-exchange chromatography of mono- and divalent cations in natural waters on a weak-acid anion-exclusion column SO JOURNAL OF CHROMATOGRAPHY A LA English DT Article; Proceedings Paper CT 10th Anniversary of the International Ion Chromatography Symposium (IICS 97) CY SEP 14-17, 1997 CL SANTA CLARA, CALIFORNIA DE mobile phase composition; water analysis; environmental analysis; inorganic cations AB Ion-exchange chromatography with indirect conductimetric detection for the simultaneous determination of mono-and divalent cations is investigated using an anion-exclusion chromatographic column packed with polymethacrylate-based weakly acidic cation-exchange resin in the H+ form (Tosoh TSKgel OA-PAK-A, 300 mmx7.8 mm I.D.). An eluent comprising a strong acid, a weak organic acid, methanol and water is used. Using 0.73 mM sulfuric acid, 2 mM tartaric acid, 7.5% (v/v) methanol in water as eluent, the monovalent cations (Na+,NH4+, and K+) and divalent cations (Mg2+ and Ca2+) were separated simultaneously by a cation-exchange mechanism in about 25 min. The application of this method to the analysis of several natural waters including rain, river, lake, underground and forest soil waters for estimating acid rain effects on the natural and urban environments is presented. (C) 1998 Elsevier Science B.V. C1 Natl Ind Res Inst Nagoya, Kita Ku, Nagoya, Aichi 4628510, Japan. Univ Tasmania, Hobart, Tas 7001, Australia. Ames Lab, Ames, IA 50011 USA. Iowa State Univ, Ames, IA 50011 USA. RP Tanaka, K (reprint author), Natl Ind Res Inst Nagoya, Kita Ku, 1-1 Hirate Cho, Nagoya, Aichi 4628510, Japan. NR 9 TC 9 Z9 9 U1 1 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0021-9673 J9 J CHROMATOGR A JI J. Chromatogr. A PD APR 24 PY 1998 VL 804 IS 1-2 BP 179 EP 186 DI 10.1016/S0021-9673(98)00031-4 PG 8 WC Biochemical Research Methods; Chemistry, Analytical SC Biochemistry & Molecular Biology; Chemistry GA ZN363 UT WOS:000073638400023 PM 9615404 ER PT J AU Klampfl, CW Buchberger, W Turner, M Fritz, GS AF Klampfl, CW Buchberger, W Turner, M Fritz, GS TI Determination of underivatized amino acids in beverage samples by capillary electrophoresis SO JOURNAL OF CHROMATOGRAPHY A LA English DT Article; Proceedings Paper CT 10th Anniversary of the International Ion Chromatography Symposium (IICS 97) CY SEP 14-17, 1997 CL SANTA CLARA, CALIFORNIA DE fruit juices; beer; food analysis; amino acids ID PEPTIDES AB A method for the analysis of free amino acids in beverage samples by capillary electrophoresis and direct UV detection at 185 nm is presented. Separations were performed in a strongly acidic carrier electrolyte containing an alkanesulfonic acid and varying amounts of acetonitrile. The organic modifier permitted a manipulation of the separation selectivity for a number of analytes investigated in this study, thereby allowing design of appropriate carrier electrolyte compositions for a given analytical problem. Orange juices as well as beer samples could be analyzed with respect to their content of free amino acids. In this way, different types of beer could be distinguished by their amino acid patterns. (C) 1998 Elsevier Science B.V. C1 Johannes Kepler Univ, Inst Analyt Chem, A-4040 Linz, Austria. Iowa State Univ Sci & Technol, Ames Lab, Ames, IA 50011 USA. Iowa State Univ Sci & Technol, Dept Chem, Ames, IA 50011 USA. RP Klampfl, CW (reprint author), Johannes Kepler Univ, Inst Analyt Chem, Altenbergerstr 69, A-4040 Linz, Austria. OI Buchberger, Wolfgang/0000-0001-6982-0558; Klampfl, Christian/0000-0001-9139-4022 NR 14 TC 39 Z9 42 U1 0 U2 8 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0021-9673 J9 J CHROMATOGR A JI J. Chromatogr. A PD APR 24 PY 1998 VL 804 IS 1-2 BP 349 EP 355 DI 10.1016/S0021-9673(98)00047-8 PG 7 WC Biochemical Research Methods; Chemistry, Analytical SC Biochemistry & Molecular Biology; Chemistry GA ZN363 UT WOS:000073638400043 ER PT J AU Superko, HR AF Superko, HR TI Inclusion of lipoprotein subfractions among efficacy parameters SO AMERICAN JOURNAL OF CARDIOLOGY LA English DT Article; Proceedings Paper CT VIth World Conference on Clinical Pharmacology and Therapeutics CY AUG, 1996 CL BUENOS AIRES, ARGENTINA SP Int Union Pharm ID CORONARY-ARTERY DISEASE; DENSITY LIPOPROTEINS; SUBCLASS PATTERNS; HEART-DISEASE; PROGRESSION; RISK; ATHEROSCLEROSIS; TRIGLYCERIDE; CHOLESTEROL; MEN C1 Berkeley Heart Lab, San Mateo, CA USA. Univ Calif San Mateo, Lawrence Berkeley Natl Lab, Cholesterol Genet & Heart Dis Inst, San Mateo, CA USA. RP Superko, HR (reprint author), Kansas Fdn Clin Pharmacol, 10550 Quivira Rd,Suite 240, Overland Pk, KS 66215 USA. OI Superko, H. Robert/0000-0002-3542-0393 NR 24 TC 3 Z9 3 U1 0 U2 0 PU EXCERPTA MEDICA INC PI NEW YORK PA 245 WEST 17TH STREET, NEW YORK, NY 10011 USA SN 0002-9149 J9 AM J CARDIOL JI Am. J. Cardiol. PD APR 23 PY 1998 VL 81 IS 8A SI SI BP 52F EP 55F DI 10.1016/S0002-9149(98)00263-X PG 4 WC Cardiac & Cardiovascular Systems SC Cardiovascular System & Cardiology GA ZN749 UT WOS:000073678300026 PM 9604909 ER PT J AU Bardeen, CJ Wang, Q Shank, CV AF Bardeen, CJ Wang, Q Shank, CV TI Femtosecond chirped pulse excitation of vibrational wave packets in LD690 and bacteriorhodopsin SO JOURNAL OF PHYSICAL CHEMISTRY A LA English DT Article ID IMPULSIVE EXCITATION; OPTICAL PULSES; RAMAN-SPECTROSCOPY; HEME-PROTEINS; DYNAMICS; ABSORPTION; EVOLUTION; MOTION; STATES; INTERFEROMETRY AB Chirped femtosecond pulses are used to selectively excite vibrationally coherent wave packets in the ground and excited states of molecules in solution. Femtosecond chirped pump/transform-limited probe experiments on both nonreactive and reactive systems (LD690 and bacteriorhodopsin) are presented, showing that slight pulse chirps can lead to large differences in the observed amplitudes and damping times of the wave packet oscillations. By comparing the experimental data with numerical simulations based on multimode harmonic oscillator models for the molecular potential energy surfaces, we conclude that positively chirped pulses discriminate against the formation of an oscillatory ground-state component via impulsive stimulated Raman scattering, while negatively chirped pulses enhance this process. The ability to separate the relative contributions of either the ground- or excited-state vibrational coherence to the transient absorption signal by slightly modifying the phase structure of the excitation pulse enables us to obtain state-specific information about the vibrational dephasing. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. RP Shank, CV (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. NR 43 TC 122 Z9 122 U1 1 U2 27 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 1089-5639 J9 J PHYS CHEM A JI J. Phys. Chem. A PD APR 23 PY 1998 VL 102 IS 17 BP 2759 EP 2766 DI 10.1021/jp980346k PG 8 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA ZM100 UT WOS:000073504700003 ER PT J AU Behar, D Dhanasekaran, T Neta, P Hosten, CM Ejeh, D Hambright, P Fujita, E AF Behar, D Dhanasekaran, T Neta, P Hosten, CM Ejeh, D Hambright, P Fujita, E TI Cobalt porphyrin catalyzed reduction of CO2. Radiation chemical, photochemical, and electrochemical studies SO JOURNAL OF PHYSICAL CHEMISTRY A LA English DT Article ID CARBON-DIOXIDE REDUCTION; ONE-ELECTRON; ELECTROCATALYTIC REDUCTION; AQUEOUS-SOLUTION; HOMOGENEOUS CATALYSIS; 2-ELECTRON REDUCTION; METAL-COMPLEXES; RATE CONSTANTS; MACROCYCLES; TETRAPHENYLPORPHYRIN AB Several cobalt porphyrins (CoP) have been reduced by radiation chemical, photochemical, and electrochemical methods, in aqueous and organic solvents. In aqueous solutions, the (CoP)-P-1 state is stable at high pH but is shorter lived in neutral and acidic solutions. Stable (CoP)-P-1 is also observed in organic solvents and is unreactive toward CO2. One-electron reduction of (CoP)-P-1 leads to formation of a species that is observed as a transient intermediate by pulse radiolysis in aqueous solutions and as a stable product following reduction by Na in tetrahydrofuran solutions. The spectrum of this species is not the characteristic spectrum of a metalloporphyrin pi-radical anion and is ascribed to (CoP)-P-0. This species binds and reduces CO2. Catalytic formation of CO and HCO2- is confirmed by photochemical experiments in acetonitrile solutions containing triethylamine as a reductive quencher. Catalytic reduction of CO2 is also confirmed by cyclic voltammetry in acetonitrile and butyronitrile solutions and is shown to occur at the potential at which (CoP)-P-1 is reduced to (CoP)-P-0. As compared with CoTPP, fluorinated derivatives are reduced, and catalyze CO2 reduction, at less negative potentials. C1 NIST, Phys & Chem Properties Div, Gaithersburg, MD 20899 USA. Howard Univ, Dept Chem, Washington, DC 20059 USA. Brookhaven Natl Lab, Dept Chem, Upton, NY 11973 USA. RP Neta, P (reprint author), NIST, Phys & Chem Properties Div, Gaithersburg, MD 20899 USA. RI Fujita, Etsuko/D-8814-2013 NR 50 TC 96 Z9 99 U1 5 U2 82 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 1089-5639 J9 J PHYS CHEM A JI J. Phys. Chem. A PD APR 23 PY 1998 VL 102 IS 17 BP 2870 EP 2877 DI 10.1021/jp9807017 PG 8 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA ZM100 UT WOS:000073504700018 ER PT J AU Wang, ZL Harfenist, SA Whetten, RL Bentley, J Evans, ND AF Wang, ZL Harfenist, SA Whetten, RL Bentley, J Evans, ND TI Bundling and interdigitation of adsorbed thiolate groups in self-assembled nanocrystal superlattices SO JOURNAL OF PHYSICAL CHEMISTRY B LA English DT Letter AB Self-assembling of nanocrystals involves organization of nanocrystals encapsulated by protective compact organic molecules into a crystalline material. The adsorbed molecules not only serve as the protection layer for the nanocrystals but also provide the dominant cohesive interactions (or "bonding") sustaining the nanocrystal superlattices. The length of the adsorbed molecules is a controllable parameter, making the ratio of particle size to interparticle distance an adjustable parameter that sensitively tunes the interparticle interaction/coupling and resulting collective properties. In this paper, bundling and interdigitation of thiolate molecules adsorbed on Ag nanocrystals are observed using the chemical imaging technique in energy-filtered transmission electron microscopy (EF-TEM) at a resolution of similar to 2 nm. In these orientationally ordered, self-assembled Ag-nanocrystal superlattices, the bundling of the adsorbed molecules on the nanocrystal surfaces is the fundamental structural principle. A model consistent with the nanocrystal's morphology and the interdigitation of the adsorbed thiolates is proposed. C1 Georgia Inst Technol, Sch Mat Sci & Engn, Atlanta, GA 30332 USA. Georgia Inst Technol, Sch Phys, Atlanta, GA 30332 USA. Oak Ridge Natl Lab, Div Met & Ceram, Oak Ridge, TN 37831 USA. RP Wang, ZL (reprint author), Georgia Inst Technol, Sch Mat Sci & Engn, Atlanta, GA 30332 USA. EM zhong.wang@mse.gatech.edu RI Evans, Neal/F-5955-2011; Wang, Zhong Lin/E-2176-2011 OI Wang, Zhong Lin/0000-0002-5530-0380 NR 17 TC 137 Z9 138 U1 0 U2 13 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 1089-5647 J9 J PHYS CHEM B JI J. Phys. Chem. B PD APR 23 PY 1998 VL 102 IS 17 BP 3068 EP 3072 DI 10.1021/jp980864v PG 5 WC Chemistry, Physical SC Chemistry GA ZM102 UT WOS:000073504900002 ER PT J AU Itoh, K Holroyd, RA Nishikawa, M AF Itoh, K Holroyd, RA Nishikawa, M TI Electron mobility in liquid alkenes under high pressure SO JOURNAL OF PHYSICAL CHEMISTRY B LA English DT Article ID NONPOLAR-SOLVENTS; NORMAL-HEXANE; N-HEXANE; 2,2-DIMETHYLBUTANE; TEMPERATURE; ATTACHMENT; TETRAMETHYLSILANE; HYDROCARBONS; EQUILIBRIUM; TOLUENE AB The mobility of excess electrons in l-pentene, cyclohexene, 2-methyl-2-butene, and 2,3-dimethyl-2-butene has been measured as a function of pressure from 1 to 3000 bar and as a function of temperature. The volume changes associated with trapping of the electron in these alkenes are derived assuming an equilibrium exists between quasi-free and trapped electrons. The volume of trapping is positive or negative, depending on the magnitude of the electrostriction term relative to the cavity term. The entropy of trapping is small. A dependence of volume change on the compressibility of the liquid is shown. C1 Brookhaven Natl Lab, Dept Chem, Upton, NY 11973 USA. Univ Tokyo, Dept Pure & Appl Sci, Tokyo 153, Japan. Kanagawa Inst Technol, Fac Engn, Atsugi, Kanagawa 24302, Japan. RP Holroyd, RA (reprint author), Brookhaven Natl Lab, Dept Chem, Upton, NY 11973 USA. NR 30 TC 7 Z9 7 U1 0 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 1520-6106 J9 J PHYS CHEM B JI J. Phys. Chem. B PD APR 23 PY 1998 VL 102 IS 17 BP 3147 EP 3151 DI 10.1021/jp980457j PG 5 WC Chemistry, Physical SC Chemistry GA ZM102 UT WOS:000073504900014 ER PT J AU Park, JH Vescovo, E Kim, HJ Kwon, C Ramesh, R Venkatesan, T AF Park, JH Vescovo, E Kim, HJ Kwon, C Ramesh, R Venkatesan, T TI Direct evidence for a half-metallic ferromagnet SO NATURE LA English DT Article ID COLOSSAL MAGNETORESISTANCE; ELECTRONIC-STRUCTURE; LA1-XSRXMNO3; PHOTOEMISSION; FILMS; NIMNSB; SYSTEM AB Half-metallic materials are characterized by the coexistence of metallic behaviour for one electron spin and insulating behaviour for the other. Thus, the electronic density of states is completely spin polarized at the Fermi level, and the conductivity is dominated by these metallic single-spin charge carriers. This exotic physical property could have a significant effect on technological applications related to magnetism and spin electronics. Some ferromagnetic systems, such as Heusler compounds(1) and chromium dioxide(2), have been predicted theoretically to be half-metallic. However, a half-metallic system has not been demonstrated directly and the predictions are still in doubt(3,4). Here we report spin-resolved photoemission measurements of a ferromagnetic manganese perovskite, La0.7Sr0.3MnO3, which directly manifest the half-metallic nature well below the Curie temperature. For the majority spin, the photoemission spectrum clearly shows a metallic Fermi cut-off, whereas for the minority spin, it shows an insulating gap with disappearance of spectral weight at similar to 0.6 eV binding energy. C1 NSLS Brookhaven Natl Lab, Upton, NY 11973 USA. Univ Maryland, Dept Phys, Ctr Superconduct Res, College Pk, MD 20742 USA. RP Park, JH (reprint author), NSLS Brookhaven Natl Lab, Upton, NY 11973 USA. EM jhpark@bnllsl.nsls.bnl.gov RI Kwon, Chuhee/A-8687-2008; Venkatesan, Thirumalai/E-1667-2013 NR 24 TC 860 Z9 876 U1 13 U2 167 PU MACMILLAN MAGAZINES LTD PI LONDON PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW SN 0028-0836 J9 NATURE JI Nature PD APR 23 PY 1998 VL 392 IS 6678 BP 794 EP 796 DI 10.1038/33883 PG 3 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA ZJ679 UT WOS:000073241200046 ER PT J AU Blaschke, D Roberts, CD Schmidt, S AF Blaschke, D Roberts, CD Schmidt, S TI Thermodynamic properties of a simple, confining model SO PHYSICS LETTERS B LA English DT Article DE field theory at finite temperature and chemical potential; confinement; dynamical chiral symmetry breaking; Dyson-Schwinger equations ID NON-PERTURBATIVE CALCULATION; GAUGE GLUON PROPAGATOR; INFRARED LIMIT; QCD; CONFINEMENT AB We study the equilibrium thermodynamics of a simple, confining, DSE-model of 2-flavour QCD at finite temperature and chemical potential. The model has two phases: one characterised by confinement and dynamical chiral symmetry breaking; and the other by their absence. The phase boundary is defined by the zero of the vacuum-pressure difference between the confined and deconfined phases. Chiral symmetry restoration and deconfinement are coincident with the transition being of first order, except for mu = 0, where it is second order. Nonperturbative modifications of the dressed-quark propagator persist into the deconfined domain and lead to a dispersion law modified by a dynamically-generated, momentum-dependent mass-scale. This entails that the Stefan-Boltzmann limit for the bulk thermodynamic quantities is attained only for large values of temperature and chemical potential. (C) 1998 Published by Elsevier Science B.V. All rights reserved. C1 Univ Rostock, Fachbereich Phys, D-18051 Rostock, Germany. Argonne Natl Lab, Div Phys, Argonne, IL 60439 USA. Tel Aviv Univ, Raymond & Beverly Sackler Fac Exact Sci, Sch Phys & Astron, IL-69978 Tel Aviv, Israel. RP Blaschke, D (reprint author), Univ Rostock, Fachbereich Phys, D-18051 Rostock, Germany. OI Roberts, Craig/0000-0002-2937-1361 NR 20 TC 92 Z9 92 U1 2 U2 5 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0370-2693 J9 PHYS LETT B JI Phys. Lett. B PD APR 23 PY 1998 VL 425 IS 3-4 BP 232 EP 238 DI 10.1016/S0370-2693(98)00229-9 PG 7 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA ZT721 UT WOS:000074118100002 ER PT J AU Wheldon, C D'Alarcao, R Chowdhury, P Walker, PM Seabury, E Ahmad, I Carpenter, MP Cullen, DM Hackman, G Janssens, RVF Khoo, TL Nisius, D Pearson, CJ Reiter, P AF Wheldon, C D'Alarcao, R Chowdhury, P Walker, PM Seabury, E Ahmad, I Carpenter, MP Cullen, DM Hackman, G Janssens, RVF Khoo, TL Nisius, D Pearson, CJ Reiter, P TI Opening up the A approximate to 180 K-isomer landscape: inelastic excitation of new multi-quasiparticle yeast traps SO PHYSICS LETTERS B LA English DT Article DE inelastic excitation; K isomer; high spin ID QUASI-PARTICLE STATES AB New high-spin isomers in Lu-175, Ta-181 and W-186 target nuclei have been strongly excited by pulsed U-238 beams. The use of inelastic excitation opens up an uncharted region in the neutron-rich K-isomer landscape. First results establish the key role of multi-quasiparticle configurations in the high-angular-momentum structure. (C) 1998 Elsevier Science B.V. All rights reserved. C1 Univ Surrey, Dept Phys, Guildford GU2 5XH, Surrey, England. Univ Massachusetts, Dept Phys, Lowell, MA 01854 USA. Argonne Natl Lab, Argonne, IL 60439 USA. Univ Liverpool, Dept Phys, Oliver Lodge Lab, Liverpool L69 7ZE, Merseyside, England. RP Univ Surrey, Dept Phys, Guildford GU2 5XH, Surrey, England. RI Wheldon, Carl/F-9203-2013; Carpenter, Michael/E-4287-2015 OI Carpenter, Michael/0000-0002-3237-5734 NR 26 TC 46 Z9 46 U1 1 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0370-2693 EI 1873-2445 J9 PHYS LETT B JI Phys. Lett. B PD APR 23 PY 1998 VL 425 IS 3-4 BP 239 EP 245 DI 10.1016/S0370-2693(98)00301-3 PG 7 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA ZT721 UT WOS:000074118100003 ER PT J AU Pinnaduwage, LA Zhu, YF AF Pinnaduwage, LA Zhu, YF TI High-Rydberg fragment formation via core dissociation of superexcited Rydberg molecules SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID THRESHOLD IONIZATION SPECTROSCOPY; STATES; EXCITATION; ENERGY; CH3I AB Formation of high-Rydberg iodine atoms via core dissociation of ArF-excimer-laser excited methyl iodide high-Rydberg molecules is observed using a time-resolved, mass-analyzed, pulsed field ionization technique. This observation confirms that the Rydberg electron is essentially a spectator in the core dissociation process. (C) 1998 American Institute of Physics. C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. Univ Tennessee, Dept Phys, Knoxville, TN 37996 USA. RP Pinnaduwage, LA (reprint author), Oak Ridge Natl Lab, POB 2008, Oak Ridge, TN 37831 USA. NR 23 TC 12 Z9 12 U1 0 U2 4 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD APR 22 PY 1998 VL 108 IS 16 BP 6633 EP 6637 DI 10.1063/1.476078 PG 5 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA ZJ230 UT WOS:000073192500014 ER PT J AU Litorja, M Ruscic, B AF Litorja, M Ruscic, B TI Direct observation of the ionization threshold of triplet methylene by photoionization mass spectrometry SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID ELECTRON PARAMAGNETIC RESONANCE; PHOTO-DISSOCIATION; POTENTIAL SURFACE; PROPAGATOR METHOD; MOLECULAR-BEAM; BOND-ENERGIES; CH2; KETENE; STATES; SPECTRUM AB The photoionization spectrum of the ionization threshold region of methylene has been recorded for the first time. The CH? radical was produced in situ by successive hydrogen abstractions from methane precursor. The observed steplike onset corresponds to the vibrationless transition CH2+(X) over tilde(2)A(1) <-- CH2 (X) over tilde(3)B(1) and leads to the adiabatic ionization energy of CH2 of 10.393 +/- 0.011 eV. This value is slightly higher than the nominal midrise of the threshold step structure, which is depressed by rotational autoionization effects. In a separate set of experiments, the threshold region of the CH2+ fragment from CH3 was recorded at room temperature. The fragment appearance energy was accurately determined by fitting to be 15.120 +/- 0.006 eV at 0 K. The combination of these two measurements provides the best current experimental value for the bond dissociation energy of the methyl radical, D-0(H-CH2) = 4.727 +/- 0.012 eV = 109.0 +/- 0.3 kcal/mol (corresponding to 110.4 +/- 0.3 kcal/mol at 298 K), and yields Delta H-f0(circle minus)(CH2, (X) over tilde B-3(1)) = 93.2 +/- 0.3 kcal/mol (93.3 +/- 0.3 kcal/mol at 298 K) and Delta H-f0(circle minus)(CH2, <(alpha)over tilde> (1)A(2)) = 102.2 +/- 0.3 kcal/mol (102.3 +/- 0.3 kcal/mol at 298 K). The latter makes the reaction CH2 (<(alpha)over tilde> (1)A(2)) + H2O --> CH3 + OH essentially thermoneurtral, Delta H-r0(circle minus) = 0.0 +/- 0.3 kcal/mol. (C) 1998 American Institute of Physics. C1 Argonne Natl Lab, Div Chem, Argonne, IL 60439 USA. RP Litorja, M (reprint author), Argonne Natl Lab, Div Chem, 9700 S Cass Ave, Argonne, IL 60439 USA. RI Ruscic, Branko/A-8716-2008 OI Ruscic, Branko/0000-0002-4372-6990 NR 65 TC 21 Z9 21 U1 0 U2 5 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD APR 22 PY 1998 VL 108 IS 16 BP 6748 EP 6755 DI 10.1063/1.476090 PG 8 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA ZJ230 UT WOS:000073192500026 ER PT J AU Drain, CM Gentemann, S Roberts, JA Nelson, NY Medforth, CJ Jia, SL Simpson, MC Smith, KM Fajer, J Shelnutt, JA Holten, D AF Drain, CM Gentemann, S Roberts, JA Nelson, NY Medforth, CJ Jia, SL Simpson, MC Smith, KM Fajer, J Shelnutt, JA Holten, D TI Picosecond to microsecond photodynamics of a nonplanar nickel porphyrin: Solvent dielectric and temperature effects SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Article ID DIFFERENTIAL-OVERLAP TECHNIQUE; RESONANCE RAMAN-SPECTROSCOPY; TRANSITION-METAL COMPLEXES; CHARGE-TRANSFER STATES; INTERMEDIATE NEGLECT; EXCITED-STATE; FORCE-FIELD; PHOTOPHYSICAL PROPERTIES; SUBSTITUTED PORPHYRINS; COPPER(II) PORPHYRINS AB The lifetime of the (d(z)(2),d(x -y)(2)) metal excited state of nickel(II) 5,10,15,20-tetra-tert-butylporphyrin (NiT(t-Bu)P) exhibits an extraordinary dependence on solvent dielectric properties and temperature. At room temperature, the excited-state deactivation time varies from 2 ps in highly polar solvents to about 50 ns in nonpolar media. The lifetimes increase to several microseconds in both polar and nonpolar solvents near 80 K. In contrast, the (d,d) lifetimes of nominally planar nickel porphyrins such as nickel tetraphenylporphyrin (NiTPP) vary only weakly with solvent dielectric properties and temperature, and typically fall in the range of 100 to 300 ps. All available evidence indicates that NiT(t-Bu)P in solution is highly ruffled (nonplanar) in the ground electronic state. It is proposed that the photoinduced conformational changes that occur in NiT(t-Bu)P in order to accommodate the excited-state electronic distribution are limited by the severe steric constraints imposed by the bulky meso tert-butyl substituents, and result in molecular and electronic asymmetry and thus a polar excited state. Solvent dielectric properties and temperature modulate these conformational excursions and thus the electronic deactivation rates by affecting the excited-state energies, porphyrin/solvent reorganizations, and the populations of low-frequency out-of-plane vibrations of the macrocycle. The novel findings for this nonplanar nickel porphyrin demonstrate the intimate connectivity that exists between the static and dynamic molecular structures of porphyrins and their ground- and excited-state electronic properties. Furthermore, the results obtained provide insights into the interactions between tetrapyrrole chromophores and their host proteins, and suggest the potential use of nonplanar porphyrins as building blocks for molecular photonics applications. C1 Washington Univ, Dept Chem, St Louis, MO 63130 USA. CUNY Hunter Coll, Dept Chem, New York, NY 10021 USA. Univ Calif Davis, Dept Chem, Davis, CA 95616 USA. Sandia Natl Labs, Mat Theory & Computat Dept, Albuquerque, NM 87185 USA. Univ New Mexico, Dept Chem, Albuquerque, NM 87131 USA. Case Western Reserve Univ, Dept Chem, Cleveland, OH 44106 USA. Brookhaven Natl Lab, Dept Appl Sci, Upton, NY 11973 USA. RP Holten, D (reprint author), Washington Univ, Dept Chem, St Louis, MO 63130 USA. RI Shelnutt, John/A-9987-2009; Simpson, Miriam/C-4237-2011; Medforth, Craig/D-8210-2013; REQUIMTE, FMN/M-5611-2013; REQUIMTE, UCIBIO/N-9846-2013; Smith, Kevin/G-1453-2011 OI Shelnutt, John/0000-0001-7368-582X; Medforth, Craig/0000-0003-3046-4909; Smith, Kevin/0000-0002-6736-4779 NR 70 TC 113 Z9 115 U1 3 U2 15 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0002-7863 J9 J AM CHEM SOC JI J. Am. Chem. Soc. PD APR 22 PY 1998 VL 120 IS 15 BP 3781 EP 3791 DI 10.1021/ja974101h PG 11 WC Chemistry, Multidisciplinary SC Chemistry GA ZK810 UT WOS:000073366000030 ER PT J AU Nagasubramanian, G Jungst, RG AF Nagasubramanian, G Jungst, RG TI Energy and power characteristics of lithium-ion cells SO JOURNAL OF POWER SOURCES LA English DT Article DE lithium-ion; Ragone data ID IMPEDANCE AB We describe below the electrochemical performance characteristics of cylindrical (18650) and prismatic (48.26 x 25.4 x 7.62) lithium-ion cells at ambient and sub-ambient temperatures. Ragone plots of power and energy data for these cells are compared, and indicate that at room temperature, the similar to 500 mAh prismatic lithium-ion cells exhibit higher specific power and power density than the similar to 1100 mAh cylindrical cells. Over the temperature range from 35 to - 20 degrees C, the cell impedance is almost constant for both cell types. These cells at 100% state-of-charge (s.o.c.) show very little voltage drop for current pulses up to 1 A. (C) 1998 Elsevier Science S.A. C1 Sandia Natl Labs, Lithium Battery Res & Dev Dept, Albuquerque, NM 87185 USA. RP Nagasubramanian, G (reprint author), Sandia Natl Labs, Lithium Battery Res & Dev Dept, POB 5800, Albuquerque, NM 87185 USA. NR 3 TC 36 Z9 37 U1 4 U2 15 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0378-7753 J9 J POWER SOURCES JI J. Power Sources PD APR 21 PY 1998 VL 72 IS 2 BP 189 EP 193 DI 10.1016/S0378-7753(97)02712-2 PG 5 WC Chemistry, Physical; Electrochemistry; Energy & Fuels; Materials Science, Multidisciplinary SC Chemistry; Electrochemistry; Energy & Fuels; Materials Science GA ZV305 UT WOS:000074291300014 ER PT J AU Huang, J Lisowski, MS Runt, J Hall, ES Kean, RT Buehler, N Lin, JS AF Huang, J Lisowski, MS Runt, J Hall, ES Kean, RT Buehler, N Lin, JS TI Crystallization and microstructure of poly(L-lactide-co-meso-lactide) copolymers SO MACROMOLECULES LA English DT Article ID BIODEGRADABLE POLYMERS; INVITRO DEGRADATION; POLY(L-LACTIC ACID); GROWTH-RATE; KINETICS; MELT; THERMODYNAMICS; MORPHOLOGIES; POLYETHYLENE; TEMPERATURE AB Small-angle X-ray scattering (SAXS), optical microscopy and differential scanning calorimetry were used to establish relationships between crystallization, microstructure, and equilibrium melting temperature (T-m(0)) for random copolymers of poly(L-lactide-co-meso-lactide). T(m)(0)s derived using the Gibbs-Thomson and data-fitting(23) approaches were found to be in excellent agreement and decreased significantly with increasing meso-lactide concentration. Analysis of these equilibrium melting temperatures using models for copolymer crystallization leads to the conclusion that the meso defects are rejected from the crystalline regions. From analysis of the SAXS data, it was concluded that the copolymers contained significant interfibrillar regions whose concentration increased with higher comonomer content. Spherulitic growth rates were strongly dependent on meso content and were analyzed using the Lauritzen-Hoffman kinetic theory of crystal growth. C1 Penn State Univ, Dept Mat Sci & Engn, University Pk, PA 16802 USA. Cargill Inc, Cent Res & Eco PLA, Minneapolis, MN 55440 USA. Oak Ridge Natl Lab, Div Solid State, Oak Ridge, TN 37831 USA. RP Runt, J (reprint author), Penn State Univ, Dept Mat Sci & Engn, University Pk, PA 16802 USA. RI He, Yong/F-8752-2012 NR 40 TC 129 Z9 136 U1 2 U2 25 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0024-9297 J9 MACROMOLECULES JI Macromolecules PD APR 21 PY 1998 VL 31 IS 8 BP 2593 EP 2599 DI 10.1021/ma9714629 PG 7 WC Polymer Science SC Polymer Science GA ZK615 UT WOS:000073342900030 ER PT J AU Hino, T Prausnitz, JM AF Hino, T Prausnitz, JM TI Lower and upper critical ordering temperatures in compressible diblock copolymer melts from a perturbed hard-sphere-chain equation of state SO MACROMOLECULES LA English DT Article ID PRESSURE-VOLUME-TEMPERATURE; LIQUID-LIQUID EQUILIBRIA; LATTICE CLUSTER THEORY; BLOCK-COPOLYMER; POLYMER BLENDS; PHASE-EQUILIBRIA; INTERACTION PARAMETERS; MICROPHASE SEPARATION; INCLUDING COPOLYMERS; DISORDER TRANSITION AB The random-phase approximation is combined with the perturbed hard-sphere-chain (PHSC) equation of state for copolymer systems to represent the microphase separation transition in compressible diblock copolymer melts. The PHSC equation of state takes into account the equation-of-state effect that results from differences in compressibility between pairs of segments comprising a diblock copolymer; these differences favor demixing. Upon increasing the temperature of a microphase-separated diblock copolymer melt, theory first predicts an order-to-disorder transition that corresponds to the upper-critical-solution-temperature behavior in the binary blend of parent homopolymers. At conditions where the equation-of-state effect is significant, theory also predicts a disorder-to-order transition at further elevated temperature that follows closely the lower-critical-solution-temperature behavior in the binary blend containing the parent homopolymers. To compare theory with experiment, we obtain the binary interaction parameter between copolymer segments from the coexistence curve for the binary blend of parent homopolymers. Predicted microphase-separation-transition temperatures of diblock copolymer melts are compared with experiment for styrene-based diblock copolymer melts including poly(styrene-bloch-n-butyl methacrylate) melts that show both order-to-disorder and disorder-to-order transitions. We also discuss the pressure dependence of order-to-disorder transition temperatures of styrene-based diblock copolymer melts. Theory and experiment show semiquantitative agreement. C1 Univ Calif Berkeley, Dept Chem Engn, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Chem Sci, Berkeley, CA 94720 USA. RP Univ Calif Berkeley, Dept Chem Engn, Berkeley, CA 94720 USA. NR 54 TC 58 Z9 58 U1 1 U2 5 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0024-9297 EI 1520-5835 J9 MACROMOLECULES JI Macromolecules PD APR 21 PY 1998 VL 31 IS 8 BP 2636 EP 2648 DI 10.1021/ma970796v PG 13 WC Polymer Science SC Polymer Science GA ZK615 UT WOS:000073342900037 ER PT J AU Litvinenko, VN Burnham, B Park, SH Wu, Y Cataldo, R Emamian, M Faircloth, J Goetz, S Hower, N Madey, JMJ Meyer, J Morcombe, P Oakeley, O Patterson, J Swift, G Wang, P Pinayev, IV Fedotov, MG Gavrilov, NG Popik, VM Repkov, VN Isaeva, LG Kulipanov, GN Kurkin, GY Mikhailov, SF Skrinsky, AN Vinokurov, NA Vobly, PD Lumpkin, A Yang, B AF Litvinenko, VN Burnham, B Park, SH Wu, Y Cataldo, R Emamian, M Faircloth, J Goetz, S Hower, N Madey, JMJ Meyer, J Morcombe, P Oakeley, O Patterson, J Swift, G Wang, P Pinayev, IV Fedotov, MG Gavrilov, NG Popik, VM Repkov, VN Isaeva, LG Kulipanov, GN Kurkin, GY Mikhailov, SF Skrinsky, AN Vinokurov, NA Vobly, PD Lumpkin, A Yang, B TI First UV/visible lasing with the OK-4/Duke storage ring FEL SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 19th International Free Electron Laser Conference/4th FEL Users Workshop CY AUG 18-21, 1997 CL BEIJING, PEOPLES R CHINA SP Inst Appl Electr, Inst High Energy Phys, China Inst Atomic Energy, Univ Electr Sci & Technol China, Peking Univ, Inst Appl Phys & Computat Math AB In this paper, we report first lasing results in the near-UV and visible spectral ranges with the OK-4/Duke storage ring - the first storage ring FEL operating in the United Slates. The OK-4/Duke FEL was commissioned in November 1996 and demonstrated lasing in the 345-413 nm range with extracted power of 0.15 W. In addition to lasing, the OK-4/Duke FEL generated a nearly monochromatic (1% FWHM) gamma-ray beams. In this paper, we describe initial performance of the OK-4/Duke storage ring FEL and gamma-ray source in this demonstration experiment. We briefly discuss the present status of the project and its future user program. (C) 1998 Published by Elsevier Science B.V. All rights reserved. C1 Duke Univ, Dept Phys, FEL Lab, Durham, NC 27708 USA. Budker Inst Nucl Phys, Novosibirsk 630090, Russia. Argonne Natl Lab, Adv Photon Source, Argonne, IL 60439 USA. RP Litvinenko, VN (reprint author), Duke Univ, Dept Phys, FEL Lab, Durham, NC 27708 USA. EM vl@phy.duke.edu NR 18 TC 36 Z9 38 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 21 PY 1998 VL 407 IS 1-3 BP 8 EP 15 DI 10.1016/S0168-9002(97)01357-0 PG 8 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA ZW290 UT WOS:000074395200004 ER PT J AU Caplan, M Bongers, WA Verhoeven, AGA van der Geer, CAJ Valentini, M Urbanus, WH AF Caplan, M Bongers, WA Verhoeven, AGA van der Geer, CAJ Valentini, M Urbanus, WH TI Prediction of the FOM FEM experimental results using multi-mode time-dependent simulations SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 19th International Free Electron Laser Conference/4th FEL Users Workshop CY AUG 18-21, 1997 CL BEIJING, PEOPLES R CHINA SP Inst Appl Electr, Inst High Energy Phys, China Inst Atomic Energy, Univ Electr Sci & Technol China, Peking Univ, Inst Appl Phys & Computat Math ID 200-GHZ; 1-MW AB The Free Electron Maser (FEM) constructed at the FOM Institute, Netherlands is now ready to undergo the first set of short pulse (< 20 mu s) experiments to demonstrate the capability of generating 1 MW of microwave power in the range 130-250 GHz. Predictions of the FEM performance requires a time-dependent multi-frequency simulation code which can include the detailed frequency dependence of the measured microwave transmission and feedback system, the time-dependent voltage pulse and the initial shot noise in the electron beam. Simulations predict that in spite of imperfections in the microwave circuit, transmission losses and a substantial voltage droop of 0.34% per mu s, megawatt levels of microwave power will be generated and observed within the 10-20 mu s voltage pulse. (C) 1998 Elsevier Science B.V. All rights reserved. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. FOM, Inst Plasma Phys, Rijnhuizen, NL-3430 BE Nieuwegein, Netherlands. RP Caplan, M (reprint author), Univ Calif Lawrence Livermore Natl Lab, 7000 East Ave,L-637, Livermore, CA 94551 USA. NR 4 TC 3 Z9 3 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD APR 21 PY 1998 VL 407 IS 1-3 BP 45 EP 49 DI 10.1016/S0168-9002(97)01365-X PG 5 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA ZW290 UT WOS:000074395200011 ER PT J AU van der Geer, CAJ Caplan, M Dionne, N van der Geer, SB de Loos, MJ Verhoeven, AGA Valentini, M van der Wiel, MJ Urbanus, WH AF van der Geer, CAJ Caplan, M Dionne, N van der Geer, SB de Loos, MJ Verhoeven, AGA Valentini, M van der Wiel, MJ Urbanus, WH TI Electron beam simulations of a multi-stage depressed collector, including secondary and scattered electrons SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 19th International Free Electron Laser Conference/4th FEL Users Workshop CY AUG 18-21, 1997 CL BEIJING, PEOPLES R CHINA SP Inst Appl Electr, Inst High Energy Phys, China Inst Atomic Energy, Univ Electr Sci & Technol China, Peking Univ, Inst Appl Phys & Computat Math AB The Fusion FEM is the prototype of a high power, rapid-tunable mm-wave source, operating in the range 130-260 GHz (Urbanus, Nucl. Instr. and Meth. A 375 (1996) 401) [1]. The device is driven by a 2 MeV, 12 A DC electron beam. A decelerator and depressed collector will be mounted behind the mm-wave cavity, for energy recovery of the unspent electron beam. This way the device will have a high system efficiency of over 50%. The unspent beam has a high-energy spread due to the FEM interaction. We report on the design of the depressed collector and on the beam transport system from the decelerator into the collector. The current streaming back has to be below 0.1%, Secondary electrons with low energy have little influence. Much attention had to be paid to prevent scattered electrons with high energies from streaming back. Two design solutions will be presented, one completely cylindrical symmetric and one with an a-symmetric bending scheme. (C) 1998 Elsevier Science B.V. All rights reserved. C1 EURATOM Assoc, FOM, Inst Plasma Phys Rijnhuizen, NL-3430 BE Nieuwegein, Netherlands. Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. Raytheon Co, Elect Syst Div, Tewksbury, MA 01876 USA. Pulsar Phys, NL-3582 SX Utrecht, Netherlands. RP van der Geer, CAJ (reprint author), EURATOM Assoc, FOM, Inst Plasma Phys Rijnhuizen, POB 1207, NL-3430 BE Nieuwegein, Netherlands. RI van der Geer, Bas/B-6251-2008 NR 6 TC 4 Z9 4 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD APR 21 PY 1998 VL 407 IS 1-3 BP 70 EP 75 DI 10.1016/S0168-9002(97)01370-3 PG 6 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA ZW290 UT WOS:000074395200017 ER PT J AU Kim, KJ AF Kim, KJ TI Undulator interruption in high-gain free-electron lasers SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 19th International Free Electron Laser Conference/4th FEL Users Workshop CY AUG 18-21, 1997 CL BEIJING, PEOPLES R CHINA SP Inst Appl Electr, Inst High Energy Phys, China Inst Atomic Energy, Univ Electr Sci & Technol China, Peking Univ, Inst Appl Phys & Computat Math ID OPTICAL-KLYSTRON; FEL AB The effect of interrupting an undulator on the performance of high-gain free-electron lasers (FELs) is evaluated by analyzing 1-D Maxwell-Vlasov equations. It is found that the effect is small for a reasonable length of the interruptions for FEL parameters envisaged for short-wavelength self-amplified spontaneous emission (SASE). Since the interruptions provide valuable space for quadrupoles and diagnostics, and at the same time permit a greater flexibility in mechanical design, the result of this paper is encouraging for construction of long undulator magnets required for SASE. (C) 1998 Elsevier Science B.V. All rights reserved. C1 Ernest Orlando Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. RP Kim, KJ (reprint author), Ernest Orlando Lawrence Berkeley Natl Lab, 1 Cyclotron Rd,MS 71-259, Berkeley, CA 94720 USA. EM kwangje@lbl.gov NR 8 TC 9 Z9 9 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD APR 21 PY 1998 VL 407 IS 1-3 BP 126 EP 129 DI 10.1016/S0168-9002(97)01381-8 PG 4 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA ZW290 UT WOS:000074395200027 ER PT J AU Milton, SV Gluskin, E Arnold, ND Berg, S Berg, W Chae, YC Crosbie, EA Dejus, RJ Den Hartog, P Friedsam, H Galayda, JN Grelick, A Jones, J Kang, Y Kim, S Lewellen, JW Lumpkin, AH Maines, JR Markovich, GM Moog, ER Nassiri, A Trakhtenberg, E Vasserman, I Vinokurov, N Walters, DR Wang, J Yang, BX AF Milton, SV Gluskin, E Arnold, ND Berg, S Berg, W Chae, YC Crosbie, EA Dejus, RJ Den Hartog, P Friedsam, H Galayda, JN Grelick, A Jones, J Kang, Y Kim, S Lewellen, JW Lumpkin, AH Maines, JR Markovich, GM Moog, ER Nassiri, A Trakhtenberg, E Vasserman, I Vinokurov, N Walters, DR Wang, J Yang, BX TI Status of the Advanced Photon Source low-energy undulator test line SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 19th International Free Electron Laser Conference/4th FEL Users Workshop CY AUG 18-21, 1997 CL BEIJING, PEOPLES R CHINA SP Inst Appl Electr, Inst High Energy Phys, China Inst Atomic Energy, Univ Electr Sci & Technol China, Peking Univ, Inst Appl Phys & Computat Math DE free-electron laser; fourth generation light source AB A Low-Energy Undulator Test Line (LEUTL) is under construction at the Advanced Photon Source (APS). Its purpose is to fully characterize innovative, future-generation undulators, and to act as a test line in pursuit of generating coherent radiation at wavelengths down to a few tens of nanometers. The line will use a high-brightness RF electron gun as its source and the APS linac to accelerate these electrons up to > 650 MeV. This beam will then be directed through undulators located in a new 50 m long enclosure. In addition, there is an end station external to the radiation environment which will house the equipment necessary to directly study the light generated by the beam and undulator system. At present, the new enclosures are complete, the electron rf gun is installed and operational, and a part of the necessary transport line is installed. A prototypical undulator cell, suitable for testing the requirements of single-pass free-electron laser operation, is near completion and will be installed during the winter shutdown of 1998. This paper will describe the LEUTL project and, in particular, its capabilities for exploring the self-amplified spontaneous emission process. (C) 1998 Elsevier Science B.V. All rights reserved. C1 Argonne Natl Lab, Adv Photon Source, Argonne, IL 60439 USA. RP Milton, SV (reprint author), Argonne Natl Lab, Adv Photon Source, 9700 S Cass Ave, Argonne, IL 60439 USA. NR 7 TC 32 Z9 32 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD APR 21 PY 1998 VL 407 IS 1-3 BP 210 EP 214 DI 10.1016/S0168-9002(97)01398-3 PG 5 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA ZW290 UT WOS:000074395200043 ER PT J AU Yu, LH Krinsky, S AF Yu, LH Krinsky, S TI Analytical theory of intensity fluctuations in SASE SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 19th International Free Electron Laser Conference/4th FEL Users Workshop CY AUG 18-21, 1997 CL BEIJING, PEOPLES R CHINA SP Inst Appl Electr, Inst High Energy Phys, China Inst Atomic Energy, Univ Electr Sci & Technol China, Peking Univ, Inst Appl Phys & Computat Math ID FREE-ELECTRON LASER; AMPLIFIED SPONTANEOUS EMISSION; HIGH-GAIN REGIME AB Recent advances in SASE experiments stimulate interest in quantitative comparison of measurements with theory. Extending our previous analysis (Krinsky and Yu, Phys. Rev. A 35 (8) (1987) 3406) of the SASE intensity in guided modes, we provide an analytical description of the intensity fluctuations by calculating intensity correlation functions in the frequency domain. Comparison of our results with experiment yields new insight into the SASE process. (C) 1998 Elsevier Science B.V. All rights reserved. C1 Brookhaven Natl Lab, Natl Synchrotron Light Source Dept, Upton, NY 11973 USA. RP Yu, LH (reprint author), Brookhaven Natl Lab, Natl Synchrotron Light Source Dept, Upton, NY 11973 USA. NR 10 TC 14 Z9 15 U1 1 U2 4 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD APR 21 PY 1998 VL 407 IS 1-3 BP 261 EP 266 PG 6 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA ZW290 UT WOS:000074395200053 ER PT J AU Babzien, M Ben-Zvi, I Catravas, P Fang, JM Marshall, TC Wang, XJ Wurtele, JS Yakimenko, V Yu, LH AF Babzien, M Ben-Zvi, I Catravas, P Fang, JM Marshall, TC Wang, XJ Wurtele, JS Yakimenko, V Yu, LH TI First observation of self-amplified spontaneous emission at 1.064 mu m SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 19th International Free Electron Laser Conference/4th FEL Users Workshop CY AUG 18-21, 1997 CL BEIJING, PEOPLES R CHINA SP Inst Appl Electr, Inst High Energy Phys, China Inst Atomic Energy, Univ Electr Sci & Technol China, Peking Univ, Inst Appl Phys & Computat Math ID MICROWIGGLER AB We report evidence of self-amplified spontaneous emission at 1064 nm. Single pass, on-axis microwiggler emissions into a 25 nm bandwidth have been recorded as a function of beam charge, and show a clear enhancement over spontaneous emission after threshold. These are the first measurements of SASE at such a short wavelength, and employ the smallest period wiggler used to date in a successful SASE experiment. The experiment has been performed with the MIT microwiggler at the Accelerator Test Facility at BNL. A single micropulse at 34 MeV with a variable charge of 0-1 nC and < 5 ps bunch length is passed through the microwiggler and emissions into a limited solid angle and bandwidth, selected by an aperture and interference filter, are focused onto a silicon photodiode. Enhancement of the emissions from 2 to 6 times the spontaneous emission level is observed at the highest charges. (C) 1998 Elsevier Science B.V. All rights reserved. C1 Brookhaven Natl Lab, Natl Synchrotron Light Source Dept, Upton, NY 11973 USA. MIT, Cambridge, MA 02139 USA. Columbia Univ, Dept Appl Phys, New York, NY 10027 USA. Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. RP Babzien, M (reprint author), Brookhaven Natl Lab, Natl Synchrotron Light Source Dept, Upton, NY 11973 USA. RI wurtele, Jonathan/J-6278-2016 OI wurtele, Jonathan/0000-0001-8401-0297 NR 7 TC 1 Z9 1 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD APR 21 PY 1998 VL 407 IS 1-3 BP 267 EP 270 DI 10.1016/S0168-9002(98)00033-3 PG 4 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA ZW290 UT WOS:000074395200054 ER PT J AU Huang, YC Plettner, T Byer, RL Pantell, RH Swent, RL Smith, TI Spencer, JE Siemann, RH Wiedemann, H AF Huang, YC Plettner, T Byer, RL Pantell, RH Swent, RL Smith, TI Spencer, JE Siemann, RH Wiedemann, H TI The physics experiment for a laser-driven electron accelerator SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 19th International Free Electron Laser Conference/4th FEL Users Workshop CY AUG 18-21, 1997 CL BEIJING, PEOPLES R CHINA SP Inst Appl Electr, Inst High Energy Phys, China Inst Atomic Energy, Univ Electr Sci & Technol China, Peking Univ, Inst Appl Phys & Computat Math DE laser; accelerator; free-electron laser ID GRADIENT; METER AB A physics experiment for laser-driven, electron acceleration in a structure-loaded vacuum is being carried out at Stanford University. The experiment is to demonstrate the linear dependence of the electron energy gain on the laser field strength. The accelerator structure, made of dielectric, is semi-open, with dimensions a few thousand times the laser wavelength. The electrons traverse the axis of two crossed laser beams to obtain acceleration within a coherence distance. We predict that the demonstration experiment will produce a single-stage, electron energy gain of 300 keV over a 2.5 mm distance. Ultimately, acceleration gradients of 1 GeV m(-1) should be possible. (C) 1998 Elsevier Science B.V. All rights reserved. C1 Stanford Univ, Edward L Ginzton Lab, Stanford, CA 94305 USA. Stanford Univ, Hansen Expt Phys Lab, Stanford, CA 94305 USA. Stanford Linear Accelerator Ctr, Stanford, CA 94305 USA. RP Huang, YC (reprint author), Natl Tsing Hua Univ, Dept Nucl Sci, Hsinchu 30043, Taiwan. NR 6 TC 19 Z9 19 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD APR 21 PY 1998 VL 407 IS 1-3 BP 316 EP 321 DI 10.1016/S0168-9002(98)00042-4 PG 6 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA ZW290 UT WOS:000074395200063 ER PT J AU Lumpkin, AH Yang, BX Litvinenko, V Burnham, B Park, S Wang, P Wu, Y AF Lumpkin, AH Yang, BX Litvinenko, V Burnham, B Park, S Wang, P Wu, Y TI Initial dual-sweep streak camera measurements on the Duke storage ring OK-4 UV/visible FEL SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 19th International Free Electron Laser Conference/4th FEL Users Workshop CY AUG 18-21, 1997 CL BEIJING, PEOPLES R CHINA SP Inst Appl Electr, Inst High Energy Phys, China Inst Atomic Energy, Univ Electr Sci & Technol China, Peking Univ, Inst Appl Phys & Computat Math ID ELECTRON AB Initial measurements at the Duke storage ring free electron laser (FEL) of both spontaneous emission radiation (SER) from the OK-4 and FEL radiation outcoupled from the oscillator cavity have been done with a dual-sweep streak camera. In the SER case, ANL's Hamamatsu C5680 streak camera was used to characterize stored electron-beam bunch lengths versus rf gap voltage and single-bunch current. Electron-beam bunch lengths were observed in a range from 50 to 300 ps (FWHM). Particle beam energies of 270 and 500 MeV in the storage ring (SR) were used with the OK-4 to generate SER from 500 nm to less than 200 nm. Sensitivity to single-bunch, single-turn SER was shown down to similar to 4 mu A beam current at lambda = 450 nm. By operating in the synchroscan mode and at bunch currents less than 1 mA, beam orbit length vs. the resonator round-trip time was investigated by detecting the relative arrival time of the second pass outcoupled from the resonator at lambda approximate to 200 nm. These measurements were used in support of first lasing in the UV-visible regime in November 1996. The dual-sweep streak mode was then used to monitor lasing intensity variations on the 1 and 50 ms time scales, to measure a lasing pulse length as short as similar to 3 ps (sigma) at lambda = 388 nm at low beam current, and to track the orbit length detuning curve. (C) 1998 Published by Elsevier Science B,V. All rights reserved. C1 Argonne Natl Lab, Adv Photon Source, Argonne, IL 60439 USA. Duke Univ, FEL Lab, Durham, NC 27708 USA. RP Lumpkin, AH (reprint author), Argonne Natl Lab, Adv Photon Source, 9700 S Cass Ave,Bldg 401, Argonne, IL 60439 USA. NR 10 TC 3 Z9 3 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD APR 21 PY 1998 VL 407 IS 1-3 BP 338 EP 342 DI 10.1016/S0168-9002(98)00046-1 PG 5 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA ZW290 UT WOS:000074395200067 ER PT J AU Song, J Piot, P Legg, R Kehne, D Li, R Feldl, E Jordan, K Denard, JC Krafft, GA Neil, GR Bohn, CL AF Song, J Piot, P Legg, R Kehne, D Li, R Feldl, E Jordan, K Denard, JC Krafft, GA Neil, GR Bohn, CL TI Real-time transverse-emittance and phase-space monitor SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 19th International Free Electron Laser Conference/4th FEL Users Workshop CY AUG 18-21, 1997 CL BEIJING, PEOPLES R CHINA SP Inst Appl Electr, Inst High Energy Phys, China Inst Atomic Energy, Univ Electr Sci & Technol China, Peking Univ, Inst Appl Phys & Computat Math AB A real-time multislit [1] transverse-emittance monitor has been developed for diagnosing the space-charge-dominated beam in the 10 MeV injection line of the FEL at Thomas Jefferson National Accelerator Facility (formerly CEBAF). It gives emittance, Twiss parameters, and phase-space contours (without any symmetry assumptions) at the update rate of 1 Hz. It reduces measurement noise in real-time, and incorporates a special algorithm for constructing the phase-space matrix, which yields more accurate results by sweeping the beam across the slits. In this paper we will discuss issues relevant to the software design and implementation. Experimental results obtained from a 250 keV photocathode gun will also be presented and compared with other methods and with PARMELA simulations. (C) 1998 Published by Elsevier Science B.V. All rights reserved. C1 Beijing Univ, Beijing 100871, Peoples R China. Thomas Jefferson Univ, Natl Accelerator Facil, Newport News, VA 23606 USA. RP Song, J (reprint author), Beijing Univ, Beijing 100871, Peoples R China. NR 6 TC 1 Z9 1 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD APR 21 PY 1998 VL 407 IS 1-3 BP 343 EP 349 DI 10.1016/S0168-9002(98)00047-3 PG 7 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA ZW290 UT WOS:000074395200068 ER PT J AU Kim, KJ Zholents, AA Zolotorev, MS Vinokurov, NA AF Kim, KJ Zholents, AA Zolotorev, MS Vinokurov, NA TI FEL options for power beaming SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 19th International Free Electron Laser Conference/4th FEL Users Workshop CY AUG 18-21, 1997 CL BEIJING, PEOPLES R CHINA SP Inst Appl Electr, Inst High Energy Phys, China Inst Atomic Energy, Univ Electr Sci & Technol China, Peking Univ, Inst Appl Phys & Computat Math ID FREE-ELECTRON LASER; ACCELERATOR AB We discuss the critical issues in designing an FEL-accelerator system for power beaming application and present several possible schemes. (C) 1998 Elsevier Science B.V. All rights reserved. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. Budker Inst Nucl Phys, Novosibirsk 630090, Russia. RP Kim, KJ (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, 1 Cyclotron Rd,MS 71-259, Berkeley, CA 94720 USA. NR 19 TC 4 Z9 4 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD APR 21 PY 1998 VL 407 IS 1-3 BP 380 EP 385 DI 10.1016/S0168-9002(98)00054-0 PG 6 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA ZW290 UT WOS:000074395200075 ER PT J AU Benson, SV Davidson, PS Jain, R Kloeppel, PK Neil, GR Shinn, MD AF Benson, SV Davidson, PS Jain, R Kloeppel, PK Neil, GR Shinn, MD TI Optical modeling of the Jefferson laboratory IR demo FEL SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 19th International Free Electron Laser Conference/4th FEL Users Workshop CY AUG 18-21, 1997 CL BEIJING, PEOPLES R CHINA SP Inst Appl Electr, Inst High Energy Phys, China Inst Atomic Energy, Univ Electr Sci & Technol China, Peking Univ, Inst Appl Phys & Computat Math ID ELECTRON AB The Thomas Jefferson National Accelerator Facility (Jefferson Lab) is in the process of a building a 1 kW free-electron laser operating 3 mu m The details of the accelerator driver are given in other papers in these proceedings. The optical cavity consists of a near-concentric resonator with transmissive outcoupling. Though several free-electron lasers have used similar designs, they have not had to confront the high average-power loading present in this laser. It is useful to know the limits of this type of optical cavity design. The optical system of the laser has been modeled using the commercial code GLAD(R) by using a Beer's-law region to mimic the FEL interaction. The effects of mirror heating have been calculated and compared with analytical treatments. The magnitude of the distortion for several materials and wave lengths has been estimated. The model developed here allows one to quickly determine whether the mirror substrates and coatings are adequate for operation at a given optical power level once the absorption of the coatings, substrate, and transmission are known. Results of calculations of the maximum power level expected using several different sets of mirrors will be presented, Measurements of the distortion in calcium fluoride from absorption of carbon dioxide laser light are planned to benchmark the simulations. Multimode simulations using the code ELIXER have been carried out to characterize the saturated optical mode quality. The results will be presented. (C) 1998 Elsevier Science B.V. All rights reserved. C1 Thomas Jefferson Natl Accelerator Facil, Lab MS 89, Newport News, VA 23606 USA. RP Benson, SV (reprint author), Thomas Jefferson Natl Accelerator Facil, Lab MS 89, 12000 Jefferson Ave, Newport News, VA 23606 USA. NR 11 TC 11 Z9 11 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD APR 21 PY 1998 VL 407 IS 1-3 BP 401 EP 406 DI 10.1016/S0168-9002(98)00058-8 PG 6 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA ZW290 UT WOS:000074395200079 ER PT J AU Osmanov, N Tolmachev, S Varfolomeev, A Varfolomeev, AA Frigola, P Hogan, M Pellegrini, C Carr, R Lidia, S AF Osmanov, N Tolmachev, S Varfolomeev, A Varfolomeev, AA Frigola, P Hogan, M Pellegrini, C Carr, R Lidia, S TI UCLA-KIAE focusing permanent magnet undulator for SASE experiment SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 19th International Free Electron Laser Conference/4th FEL Users Workshop CY AUG 18-21, 1997 CL BEIJING, PEOPLES R CHINA SP Inst Appl Electr, Inst High Energy Phys, China Inst Atomic Energy, Univ Electr Sci & Technol China, Peking Univ, Inst Appl Phys & Computat Math DE magnet; undulator; construction ID FIELD-MEASUREMENTS AB A description of a new 2 m undulator is presented which was specially designed and manufactured for a SASE mode FEL experiment. It is a one section two plane focusing permanent magnet construction. The uniform period length is 2.06 cm, total number of periods is 98. The peak field on the axis is 5.4 kG for a 5 mm gap. (C) 1998 Elsevier Science B.V. All rights reserved. C1 Russian Res Ctr, Coherent Radiat Lab, Kurchatov Inst, Moscow 123182, Russia. Univ Calif Los Angeles, Dept Phys & Astron, Los Angeles, CA 90095 USA. Stanford Synchrotron Radiat Lab, Stanford, CA 94309 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Varfolomeev, A (reprint author), Russian Res Ctr, Coherent Radiat Lab, Kurchatov Inst, Moscow 123182, Russia. EM varfolom@lki.msk.ru 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 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD APR 21 PY 1998 VL 407 IS 1-3 BP 423 EP 427 DI 10.1016/S0168-9002(98)00062-X PG 5 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA ZW290 UT WOS:000074395200083 ER PT J AU Tatchyn, R AF Tatchyn, R TI Field design studies of a planar hybrid/permanent magnet undulator with strong planar permanent magnet focusing SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 19th International Free Electron Laser Conference/4th FEL Users Workshop CY AUG 18-21, 1997 CL BEIJING, PEOPLES R CHINA SP Inst Appl Electr, Inst High Energy Phys, China Inst Atomic Energy, Univ Electr Sci & Technol China, Peking Univ, Inst Appl Phys & Computat Math ID FEL; SCHEMES AB Undulators for Free Electron Laser (FEL) amplifiers driven by multi-GeV electron beams generally require superimposed focusing substantially stronger than that provided by their natural focusing fields. In recent years a wide variety of focusing schemes and configurations have been proposed for undulators of this class, ranging from conventional current-driven quadrupoles external to the undulator magnets to permanent magnet (PM) lattices inserted into, or adjacent to, the insertion device gap. In this paper we present design studies of the field structure of a flexible hybrid/PM undulator with superimposed planar PM focusing proposed for a 1.5 Angstrom Linac Coherent Light Source (LCLS) undulator driven by an electron beam with a 1 mm mrad normalized emittance. Attainable field parameters, tuning modes, and trajectory performance of the proposed structure are discussed. (C) 1998 Elsevier Science B.V. All rights reserved. C1 Stanford Linear Accelerator Ctr, Stanford Synchrotron Radiat Lab, Stanford, CA 94309 USA. RP Tatchyn, R (reprint author), Stanford Linear Accelerator Ctr, Stanford Synchrotron Radiat Lab, Stanford, CA 94309 USA. NR 14 TC 1 Z9 1 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD APR 21 PY 1998 VL 407 IS 1-3 BP 454 EP 458 DI 10.1016/S0168-9002(97)01362-4 PG 5 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA ZW290 UT WOS:000074395200089 ER PT J AU Maiya, PS Erck, RA Moon, BM AF Maiya, PS Erck, RA Moon, BM TI Failure and corrosion resistance of TiN and TiC coatings deposited on graphite by chemical vapor deposition SO SURFACE & COATINGS TECHNOLOGY LA English DT Article DE TiN; TiC; chemical vapor deposition; graphite coatings; pin-pull test; adhesion; corrosion resistance ID BRITTLE AB Adhesion and chemical stability tests were used to investigate graphite coated with TiN and TiC by chemical vapor deposition. Pin-pull tests were used to determine adhesion of the coatings and the failure stresses were analyzed by Weibull statistical analysis. All pull tests resulted in fracture of the graphite substrate. The data showed a good fit tn thp two-parameter Weibull expression, with failure strength near 16.4-17.6 MPa and Weibull moduli of 9.3 and 8.5 for TiN- and TiC-coated graphite, respectively. The coated specimens were exposed to a corrosive molten salt, CaCl2, and a liquid metal alloy (Zn-10 wt.% Mg) at 800 degrees C for 168 h to determine corrosion resistance. No reaction was detected by scanning electron microscopy or energy-dispersive X-ray, Thus, graphite coated with TiC and TiN by chemical vapor deposition is promising for use as a container material for pyrochemical processing of certain rare-earth and nuclear metals, where chemical inertness and a good match of thermal expansion coefficients are required. (C) 1998 Elsevier Science S.A. C1 Argonne Natl Lab, Div Energy Technol, Argonne, IL 60439 USA. SGL Carbon Corp, Dallas, TX 75247 USA. RP Maiya, PS (reprint author), Argonne Natl Lab, Div Energy Technol, 9700 S Cass Ave, Argonne, IL 60439 USA. NR 18 TC 5 Z9 5 U1 0 U2 4 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0257-8972 J9 SURF COAT TECH JI Surf. Coat. Technol. PD APR 21 PY 1998 VL 102 IS 3 BP 218 EP 222 DI 10.1016/S0257-8972(97)00690-7 PG 5 WC Materials Science, Coatings & Films; Physics, Applied SC Materials Science; Physics GA ZR798 UT WOS:000074014800005 ER PT J AU Marquardt, R Balster, A Sander, W Kraka, E Cremer, D Radziszewski, JG AF Marquardt, R Balster, A Sander, W Kraka, E Cremer, D Radziszewski, JG TI p-Benzyne SO ANGEWANDTE CHEMIE-INTERNATIONAL EDITION LA English DT Article DE ab initio calculations; density functional calculations; matrix isolation; photochemistry; radicals ID META-BENZYNE; ABSOLUTE HEATS; ENERGY; THERMOCHEMISTRY; ENEDIYNE; ETHYL C1 Ruhr Univ Bochum, Lehrstuhl Organ Chem 2, D-44780 Bochum, Germany. Univ Gothenburg, Dept Theoret Chem, S-41296 Gothenburg, Sweden. Natl Renewable Energy Lab, Golden, CO 80401 USA. RP Sander, W (reprint author), Ruhr Univ Bochum, Lehrstuhl Organ Chem 2, D-44780 Bochum, Germany. EM sander@neon.orch.ruhr-uni-bochum.de; cremer@theoc.chalmers.se; jradzisz@nrel.nrel.gov NR 37 TC 47 Z9 47 U1 1 U2 7 PU WILEY-V C H VERLAG GMBH PI BERLIN PA MUHLENSTRASSE 33-34, D-13187 BERLIN, GERMANY SN 1433-7851 J9 ANGEW CHEM INT EDIT JI Angew. Chem.-Int. Edit. PD APR 20 PY 1998 VL 37 IS 7 BP 955 EP 958 DI 10.1002/(SICI)1521-3773(19980420)37:7<955::AID-ANIE955>3.0.CO;2-T PG 4 WC Chemistry, Multidisciplinary SC Chemistry GA ZK576 UT WOS:000073339000021 ER PT J AU Warner, BP Scott, BL Burns, CJ AF Warner, BP Scott, BL Burns, CJ TI A simple preparative route to bis(imido)-uranium(VI) complexes by the direct reductions of diazenes and azides SO ANGEWANDTE CHEMIE-INTERNATIONAL EDITION LA English DT Article DE actinides; azo compounds; f orbitals; imido compounds; uranium ID VALENT ORGANOURANIUM COMPLEXES; OXIDATIVE ADDITION; ORGANOMETALLIC CHEMISTRY; TRIVALENT URANIUM; FUNCTIONAL-GROUPS; OXO-ALKYLIDENE; WCL2(PMEPH2)4; ORGANOIMIDO; THORIUM; IMIDO C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Burns, CJ (reprint author), Univ Calif Los Alamos Natl Lab, MS J514, Los Alamos, NM 87545 USA. EM cjb@lanl.gov RI Scott, Brian/D-8995-2017 OI Scott, Brian/0000-0003-0468-5396 NR 25 TC 107 Z9 107 U1 1 U2 18 PU WILEY-V C H VERLAG GMBH PI BERLIN PA MUHLENSTRASSE 33-34, D-13187 BERLIN, GERMANY SN 1433-7851 J9 ANGEW CHEM INT EDIT JI Angew. Chem.-Int. Edit. PD APR 20 PY 1998 VL 37 IS 7 BP 959 EP 960 DI 10.1002/(SICI)1521-3773(19980420)37:7<959::AID-ANIE959>3.0.CO;2-D PG 2 WC Chemistry, Multidisciplinary SC Chemistry GA ZK576 UT WOS:000073339000022 ER PT J AU Suhre, DR Villa, E AF Suhre, DR Villa, E TI Imaging spectroradiometer for the 8-12-mu m region with a 3-cm(-1) passband acousto-optic tunable filter SO APPLIED OPTICS LA English DT Article ID RESOLUTION; DESIGN AB An imaging spectroradiometer was built covering the 8-12-mu m region with an acousto-optic tunable filter with a 3-cm(-1) passband, along with a commercial infrared camera. The system field of view was 7.5 degrees x 10 degrees, and the resolution was nearly diffraction limited. Real-time images were digitally recorded, and software was used to enhance the data and increase the camera temperature sensitivity to less than a millidegree Kelvin. The minimum discernible intensity was 10(-3) that of a globar source at 900 K, and emission from SF6 could be imaged at ambient temperatures. (C) 1998 Optical Society of America. C1 Northrup Grumman Sci & Technol Ctr, Pittsburgh, PA 15235 USA. Savannah River Technol Ctr, Aiken, SC 29801 USA. RP Suhre, DR (reprint author), Northrup Grumman Sci & Technol Ctr, 1350 Beulah Rd, Pittsburgh, PA 15235 USA. NR 19 TC 29 Z9 30 U1 0 U2 1 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA SN 0003-6935 J9 APPL OPTICS JI Appl. Optics PD APR 20 PY 1998 VL 37 IS 12 BP 2340 EP 2345 DI 10.1364/AO.37.002340 PG 6 WC Optics SC Optics GA ZH797 UT WOS:000073148600021 PM 18273161 ER PT J AU Celliers, PM Estabrook, KG Wallace, RJ Murray, JE Da Silva, LB MacGowan, BJ Van Wonterghem, BM Manes, KR AF Celliers, PM Estabrook, KG Wallace, RJ Murray, JE Da Silva, LB MacGowan, BJ Van Wonterghem, BM Manes, KR TI Spatial filter pinhole for high-energy pulsed lasers SO APPLIED OPTICS LA English DT Article AB Spatial filters are essential components for maintaining high beam quality in high-energy pulsed laser systems. The long-duration (21 ns) high-energy pulses envisioned for future inertial-confinement fusion drive systems, such as the U.S. National Ignition Facility (NIF), are likely to lead to increased plasma generation and closure effects within the pinholes in the spatial filters. The design goal for the pinhole spatial filter for the NIF design is to remove small-angle scatter in the beam to as little as a +/- 100-mu rad divergence. It is uncertain whether this design requirement can be met with a conventional pinhole design. We propose a new pinhole architecture that addresses these issues by incorporating features intended to reduce the rate of plasma generation. Initial experiments with this design have verified its performance improvement relative to a conventional pinhole design. (C) 1998 Optical Society of America. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. RP Celliers, PM (reprint author), Univ Calif Lawrence Livermore Natl Lab, POB 808, Livermore, CA 94551 USA. NR 10 TC 24 Z9 31 U1 5 U2 16 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA SN 0003-6935 J9 APPL OPTICS JI Appl. Optics PD APR 20 PY 1998 VL 37 IS 12 BP 2371 EP 2378 DI 10.1364/AO.37.002371 PG 8 WC Optics SC Optics GA ZH797 UT WOS:000073148600026 PM 18273166 ER PT J AU Gopalan, V Mitchell, TE Furukawa, Y Kitamura, K AF Gopalan, V Mitchell, TE Furukawa, Y Kitamura, K TI The role of nonstoichiometry in 180 degrees domain switching of LiNbO3 crystals SO APPLIED PHYSICS LETTERS LA English DT Article ID DEFECT STRUCTURES; LITHIUM-NIOBATE AB We show here conclusively that the internal field originates from nonstoichiometric point defects in LiNbO3 crystals. The switching fields required for 180 degrees domain reversal in congruent crystals [C =Li2O/(Li2O+Nb2O5)=0.484] are similar to 4-5 times larger than the switching fields for near-stoichiometric crystals (C=0.498). An internal field of similar to 2.5 k (V) over bar/mm observed in congruent crystals disappears in stoichiometric crystals. The concentration of hydrogen incorporated during crystal growth has no effect on the switching or internal fields. The measured spontaneous polarization, P-s=80+/-5 mu C/cm(2) is relatively insensitive to the crystal nonstoichiometry and the hydrogen content. (C) 1998 American Institute of Physics. C1 Univ Calif Los Alamos Natl Lab, Ctr Mat Sci, Los Alamos, NM 87545 USA. Natl Inst Res Inorgan Mat, Tsukuba, Ibaraki 305, Japan. RP Gopalan, V (reprint author), Univ Calif Los Alamos Natl Lab, Ctr Mat Sci, MS K765, Los Alamos, NM 87545 USA. NR 15 TC 238 Z9 248 U1 3 U2 38 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD APR 20 PY 1998 VL 72 IS 16 BP 1981 EP 1983 DI 10.1063/1.121491 PG 3 WC Physics, Applied SC Physics GA ZJ533 UT WOS:000073226300015 ER PT J AU Wei, SH Zunger, A AF Wei, SH Zunger, A TI Calculated natural band offsets of all II-VI and Ill-V semiconductors: Chemical trends and the role of cation d orbitals SO APPLIED PHYSICS LETTERS LA English DT Article ID HETEROJUNCTIONS; DISCONTINUITY; ENERGY; CDTE; HGTE AB Using first-principles all-electron band structure method, we have systematically calculated the natural band offsets Delta E-v between all II-VI and separately between III-V semiconductor compounds. Fundamental regularities are uncovered: for common-cation systems Delta E-v decreases when the cation atomic number increases, while for common-anion systems Delta E-v decreases when the anion atomic number increases. We find that coupling between anion p and cation d states plays a decisive role in determining the absolute position of the valence band maximum and thus the observed chemical trends. (C) 1998 American Institute of Physics. C1 Natl Renewable Energy Lab, Golden, CO 80401 USA. RP Wei, SH (reprint author), Natl Renewable Energy Lab, Golden, CO 80401 USA. RI Zunger, Alex/A-6733-2013 NR 18 TC 491 Z9 494 U1 6 U2 132 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD APR 20 PY 1998 VL 72 IS 16 BP 2011 EP 2013 DI 10.1063/1.121249 PG 3 WC Physics, Applied SC Physics GA ZJ533 UT WOS:000073226300025 ER PT J AU Solheim, JE Provencal, JL Bradley, PA Vauclair, G Barstow, MA Kepler, SO Fontaine, G Grauer, AD Winget, DE Marar, TMK Leibowitz, EM Emanuelsen, PI Chevreton, M Dolez, N Kanaan, A Bergeron, P Claver, CF Clemens, JC Kleinman, SJ Hine, BP Seetha, S Ashoka, BN Mazeh, T Sansom, AE Tweedy, RW Meistas, EG Bruvold, A Massacand, CM AF Solheim, JE Provencal, JL Bradley, PA Vauclair, G Barstow, MA Kepler, SO Fontaine, G Grauer, AD Winget, DE Marar, TMK Leibowitz, EM Emanuelsen, PI Chevreton, M Dolez, N Kanaan, A Bergeron, P Claver, CF Clemens, JC Kleinman, SJ Hine, BP Seetha, S Ashoka, BN Mazeh, T Sansom, AE Tweedy, RW Meistas, EG Bruvold, A Massacand, CM TI Whole earth telescope observations of AM Canum Venaticorum - discoseismology at last SO ASTRONOMY & ASTROPHYSICS LA English DT Article DE stars : individual : AM Canum Venaticorum; novae, cataclysmic variables; stars : oscillations; white dwarfs; accretion, accretion disks ID URSAE MAJORIS STARS; ACCRETION DISKS; CLOSE BINARY; CVN; DWARF; SUPEROUTBURST; SUPERHUMPS; SPECTRUM; PERIOD; G61-29 AB We report the results of 143.2 hours of time-series photometry over a 12 day period for AM CVn (= HZ 29) as part of the Whole Earth Telescope (WET) project.(1) This star is believed to be an ultra-short period cataclysmic binary. In the temporal spectrum of the light curve we find a series of 5 harmonically related frequency mo dulations, some with sidebands with a constant frequency spacing of 20.8 mu Hz always on the high-frequency side. The set of harmonics has a fundamental frequency of 951 mu Hz. NO modulation is detected at this frequency in the light curve. In addition, modulations with frequencies 972.5 and 988.9 mu Hz are detected with low amplitudes. The structure of the dominant 1903 mu Hz modulation explains part of the "phase jitter" observed earlier. The amplitude of this peak is modulated with a period of 13.32 +/- 0.05 hrs. The same period is detected in absorption line shape modulations, most likely arising from variable aspects of the outer parts of the disk (Patterson et al. 1993). The observed periodic light modulations can be explained as a combination of aspect variations of disk modifications due to tidally induced shocks as described by Savonie et al. (1994), which leads to a two-armed spiral structure, and the mode coupling model of Lubow (1991), which leads to a three-fold azimuthal symmetry in the outer parts of the disk and a prograde precessing wave. The two-and three-fold aszimuthal structures are stationary in the binary frame and explain the higher harmonics of the orbital period we observe in the light curve. This may be the first example of a successful disco-seismological interpretation. In addition we propose that the variable amplitude modulation at 989 mu Hz may be explained as a g-mode pulsation, which indicates that the central white dwarf may be a DO with a hot envelope. C1 Univ Tromso, Inst Fys, Nordlysobserv, N-9037 Tromso, Norway. Univ Texas, Dept Astron, Austin, TX 78712 USA. Univ Texas, Mcdonald Observ, Austin, TX 78712 USA. Observ Midi Pyrenees, F-31400 Toulouse, France. Univ Leicester, Dept Phys & Astron, Leicester LE1 7RH, Leics, England. Univ Fed Rio Grande do Sul, Inst Fis, BR-91500970 Porto Alegre, RS, Brazil. Univ Montreal, Dept Phys, Montreal, PQ H3C 3J7, Canada. Univ Arkansas, Dept Phys & Astron, Little Rock, AR 72204 USA. ISRO Satelite Ctr, Tech Phys Div, Bangalore 560017, Karnataka, India. Tel Aviv Univ, Dept Phys & Astron, IL-69978 Tel Aviv, Israel. Observ Paris, F-92195 Meudon, France. Vilnius State Univ, Inst Mat Res & Appl Sci, LT-2009 Vilnius, Lithuania. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. Inst Theoret Phys & Astron, Astron Observ, LT-2600 Vilnius, Lithuania. Univ Delaware, Dept Phys, Newark, DE 19716 USA. Los Alamos Natl Lab, XTA, Los Alamos, NM 87545 USA. Kitt Peak Natl Observ, Tucson, AZ 85726 USA. CALTECH, Pasadena, CA 91125 USA. Univ Cent Lancashire, Ctr Astrophys, Preston PR1 2HE, Lancs, England. RP Solheim, JE (reprint author), Univ Tromso, Inst Fys, Nordlysobserv, N-9037 Tromso, Norway. RI Kepler, S. O. /H-5901-2012 OI Kepler, S. O. /0000-0002-7470-5703 NR 55 TC 28 Z9 28 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 0004-6361 J9 ASTRON ASTROPHYS JI Astron. Astrophys. PD APR 20 PY 1998 VL 332 IS 3 BP 939 EP 957 PG 19 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA ZL736 UT WOS:000073465300023 ER PT J AU Klein, RI Woods, DT AF Klein, RI Woods, DT TI Bending mode instabilities and fragmentation in interstellar cloud collisions: A mechanism for complex structure SO ASTROPHYSICAL JOURNAL LA English DT Article DE hydrodynamics; instabilities; ISM, clouds; stars, formation ID H I CLOUDS; STAR-FORMATION; MOLECULAR CLOUD; ORION; HYDRODYNAMICS; STREAMERS; SYSTEMS; BINARY; SHOCKS; WINDS AB A fundamental problem in interstellar gasdynamics is the collision between two interstellar clouds. We present high-resolution two-dimensional results of this interaction using Adaptive mesh refinement (AMR) hydrodynamics with a Godunov scheme for accurate shock tracking in multidimensions. These results are at a resolution that is significantly higher than has been previously achieved by other methodologies such as smoothed particle hydrodynamics. We have studied the collisions between homogeneous clouds with an adiabatic equation of state, isothermal clouds, radiatively cooling clouds, and clouds with initial surface perturbations. In all instances, the collision is complex, resulting in flows that are strongly influenced by Kelvin-Helmholtz and nonlinear thin shell bending mode instabilities. In particular we find that the early evolution of homogeneous cloud collisions initially produces a cold dense disk in the collision midplane. A low mass jet propagates outward with characteristics of dense protostellar jets in a low-density medium. Once the clouds have been compressed by strong shocks, pressure gradients drive the dense disk to re-expand along the symmetry axis. This reexpansion overshoots, resulting in a pressure deficit in the interior of the merged cloud system and a collapse back onto the symmetry axis. If the colliding clouds are initially smooth, the end result of the collision is a large aspect ratio filament with a homogeneous interior and an irregular surface. If the clouds have finite surface perturbations, a bending mode instability renders the merged cloud system asymmetrical and highly inhomogeneous with islands of high density surrounded by low density regions throughout the interior. These results have implications for coelescence models of star formation. The appearance of the merged system is that of a clumpy filamentary structure with a large aspect ratio. This instability is shown to occur for both isothermal shocks, as well as shocks with radiative cooling. The instability occurs in adiabatic shocks for compressions greater than 10. The bending mode instability increases the vorticity of the merged cloud system, resulting in an axial velocity that is twice as large as in the smooth cloud case. Recent observations show an abundance of elongated clumpy filaments in the Orion Molecular Cloud (OMC-1). Our calculations of cloud-cloud collisions undergoing the bending mode instability provide a new mechanism for for generating inhomogeneous filamentary structures which appear to be common in the interstellar medium. C1 Univ Calif Berkeley, Dept Astron, Theoret Astrophys Ctr, Berkeley, CA 94720 USA. Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA. RP Klein, RI (reprint author), Univ Calif Berkeley, Dept Astron, Theoret Astrophys Ctr, 601 Campbell Hall, Berkeley, CA 94720 USA. EM klein@radhydro.berkeley.edu; tod@eaglevail.llnl.gov NR 36 TC 44 Z9 44 U1 0 U2 3 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD APR 20 PY 1998 VL 497 IS 2 BP 777 EP + DI 10.1086/305488 PN 1 PG 30 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA ZJ199 UT WOS:000073189400025 ER PT J AU Szkody, P Hoard, DW Sion, EM Howell, SB Cheng, FH Sparks, WM AF Szkody, P Hoard, DW Sion, EM Howell, SB Cheng, FH Sparks, WM TI Ultraviolet and optical spectroscopy of AL Comae 1 year after superoutburst SO ASTROPHYSICAL JOURNAL LA English DT Article DE novae, cataclysmic variables; stars, individual (AL Com); ultraviolet, stars; white dwarfs ID HUBBLE-SPACE-TELESCOPE; NOVA WZ SAGITTAE; WHITE-DWARF; CATACLYSMIC VARIABLES; U-GEMINORUM; VW HYDRI; QUIESCENCE; FAINT; BERENICES; EVOLUTION AB We present Hubble Space Telescope (HST) ultraviolet spectra of AL Com obtained with the Faint Object Spectrograph (FOS) during four epochs 10-14 months following its 1995 April superoutburst. During our 1996 observations, the continuum fluxes underwent a slow decline of 20%, while the spectrum showed Ly alpha and Si II absorption features indicative of a 20,000 K white dwarf. The cooling sequence in AL Com is found to be about half as long as that of WZ Sge. This timescale is what is predicted for an outburst that was half the duration of WZ Sge, if shear mixing and angular momentum result in nonspherical accretion into an equatorial belt. Our longest data set (1996 June) showed spectral line variations on the orbital period with C IV in emission for about one-third of the orbit but revealed no orbital variability in the continuum. Ground-based optical spectra obtained close in time to our February HST data also show stronger line emission for one-third of an orbit and highly variable broad absorption from the secondary star. The spectral variations may be due to the changing visibility of a nonuniform disk or of a secondary star irradiated by the hot white dwarf. C1 Univ Washington, Dept Astron, Seattle, WA 98195 USA. Villanova Univ, Dept Astron & Astrophys, Villanova, PA 19085 USA. Univ Wyoming, Dept Phys & Astron, Laramie, WY 82071 USA. Univ Sci & Technol China, Ctr Astrophys, Hefei 230026, Anhui, Peoples R China. Univ Calif Los Alamos Natl Lab, Nucl Hydrodynam Applicat Grp, Los Alamos, NM 87545 USA. RP Szkody, P (reprint author), Univ Washington, Dept Astron, Seattle, WA 98195 USA. EM szkody@astro.washington.edu; emsion@ucis.vill.edu; showell@mothra.uwyo.edu; fhcheng@ucis.vill.edu; wms@lanl.gov NR 36 TC 22 Z9 22 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 5801 S ELLIS AVENUE, CHICAGO, IL 60637 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD APR 20 PY 1998 VL 497 IS 2 BP 928 EP 934 DI 10.1086/305506 PN 1 PG 7 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA ZJ199 UT WOS:000073189400039 ER PT J AU Garten, CT Schwab, AB Shirshac, TL AF Garten, CT Schwab, AB Shirshac, TL TI Foliar retention of N-15 tracers: implications for net canopy exchange in low- and high-elevation forest ecosystems SO FOREST ECOLOGY AND MANAGEMENT LA English DT Article DE nitrogen; deposition; throughfall; stable isotopes ID PICEA-ABIES KARST; WET DEPOSITION; RED SPRUCE; ATMOSPHERIC DEPOSITION; NITROGEN UPTAKE; WHITE OAK; SEEDLINGS; MAPLE; VAPOR; RAIN AB Nitrogen-15(N-15) labelled ammonium and nitrate were applied to understory saplings in a low-elevation deciduous forest and a high-elevation coniferous forest during the 1993 growing season to estimate the minimum retention of inorganic N from wet deposition. Tissue samples were collected at both sites before and after: the tracer applications to determine the initial and the final N-15 content. The fraction of the tracer application retained by ceciduous leaves or by current-year leaves and stems on conifers was calculated from measurements of N-15 and total N content. At both study sites, tracer applications significantly increased the N-15 content of sapling tissues, although there was no significant difference between the fractional retention of ammonium and nitrate. The results support earlier studies indicating that the foliar retention of N-15 applied in simulated wet deposition is small. Our estimates of annual N uptake from wet deposition by the forest canopy at the low- and high-elevation study sites were only 14 and 7%, respectively. This study, along with prior studies of the different chemical forms of N deposition, indicates that canopy uptake of dry N deposition is a major contributor to the net canopy exchange of N in both forests. (C) 1998 Elsevier Science B.V. C1 Oak Ridge Natl Lab, Div Environm Sci, Oak Ridge, TN 37831 USA. RP Garten, CT (reprint author), Oak Ridge Natl Lab, Div Environm Sci, POB 2008, Oak Ridge, TN 37831 USA. NR 16 TC 28 Z9 32 U1 1 U2 14 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0378-1127 J9 FOREST ECOL MANAG JI For. Ecol. Manage. PD APR 20 PY 1998 VL 103 IS 2-3 BP 211 EP 216 DI 10.1016/S0378-1127(97)00185-0 PG 6 WC Forestry SC Forestry GA ZJ619 UT WOS:000073234900010 ER PT J AU Lugmair, CG Tilley, TD AF Lugmair, CG Tilley, TD TI Di-tert-butyl phosphate complexes of titanium SO INORGANIC CHEMISTRY LA English DT Article ID CRYSTAL-STRUCTURES; KTIOPO4; CHEMISTRY; ALKOXIDES; ALUMINUM; FILMS AB Reactions of 1 equiv of HO(O)P((OBu)-Bu-t)(2) with Ti(OR)(4) (R = Et, Pr-i) give the new molecular titanium phosphates [Ti(OR)(3)O2P((OBu)-Bu-t)(2)](n) (1, R = Et; 2, R = Pr-i). In the solid state, 2 exists as a centrosymmetric dimer containing five-coordinate metal centers. Addition of 2 equiv of KOEt to an ethanol solution of 1 led to the formation of [Ti2K(OEt)(8)O2P((OBu)-Bu-t)(2)](2) (3) and 1 equiv of KO2P((OBu)-Bu-t)(2). A single-crystal X-ray structure analysis of 3 revealed that this complex exists in the solid state as a centrosymmetric dimer containing two Ti-centered, face-sharing pseudooctahedra in the unique half of the dimer. Addition of 2 equiv of (KOPr)-Pr-i to a 2-propanol solution of 2 led to the formation of KO2P((OBu)-Bu-t)(2) (4) and Ti((OPr)-Pr-i)(4) in high yield. Cooling a 2-propanol solution of 4 to -80 degrees C led to crystallization of the solvated tetramer [4 . (HOPr3)-Pr-i](4) (mp = -30 degrees C). A single-crystal X-ray structure analysis revealed that this tetramer possesses a cubelike K4O4 core with 4-fold improper rotation symmetry. Multinuclear NMR studies of 1-3 show that the structures of these complexes are dynamic in solution. Crystals of 4 are tetragonal (P4(2)/(n)) with a = 15.6261(3) Angstrom, c = 14.7114(3) Angstrom, and Z = 8. C1 Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Chem Sci, Berkeley, CA 94720 USA. RP Tilley, TD (reprint author), Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. NR 37 TC 40 Z9 40 U1 1 U2 7 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0020-1669 J9 INORG CHEM JI Inorg. Chem. PD APR 20 PY 1998 VL 37 IS 8 BP 1821 EP 1826 DI 10.1021/ic971347e PG 6 WC Chemistry, Inorganic & Nuclear SC Chemistry GA ZJ655 UT WOS:000073238400020 ER PT J AU Nataro, C Chen, JB Angelici, RJ AF Nataro, C Chen, JB Angelici, RJ TI Cyanide ligand basicities in Cp ' M(L)(2)CN complexes (M = Ru, Fe). Correlation between heats of protonation and nu CN SO INORGANIC CHEMISTRY LA English DT Article ID CYCLOPENTADIENYL-OSMIUM CHEMISTRY; TRANSITION-METAL COMPLEXES; NUCLEOPHILIC PROPERTIES; RUTHENIUM; DERIVATIVES; ELECTROCHEMISTRY; ENTHALPIES; REACTIVITY; HYDRIDE; HALIDE AB Basicities of the cyanide ligands in a series of Cp'M(L)(2)CN complexes were investigated by measuring their heats of protonation (-Delta N-CNH) by CF3SO3H in 1,2-dichloroethane solution at 25.0 degrees C to give Cp'M(L)(2)(CNH)+CF3SO3-, in which the N-H+ group is probably hydrogen-bonded o the CF3SO3- anion. Basicities (-Delta H-CNH) Of the CpRu(PR3)(2)CN complexes increase from 20.5 (PPh3) to 22.4 (PMe3) kcal/mol with increasing donor abilities of the phosphine ligands. Basicities of all the Cp'Ru(PR3)(2)CN complexes, where Cp' Cp or Cp*, are linearly correlated with their nu CN values; the nonphosphine complexes, CpRu(1,10-phen)CN and CpRu(COD)CN, do not follow the same correlation. For a large number of Cp'M(L)(2)CN complexes (M = Ru, Fe, L-2 = mono- and bidentate phosphines, CO, 1,10-phen, and COD), their nu CN values parallel nu CN values of their protonated Cp'M(L)(2)(CNH)(+) analogues. Also, P-31 NMR chemical shifts of the unprotonated Cp'M(PR3)(2)CN and protonated CpM(PR3)(2)(CNH)(+) complexes are linearly related. Despite the high basicity of Ru in Cp*Ru(PMe3)(2)Cl (30.2 kcal/mol), the CN-in Cp*Ru(PMe3)(2)CN (25.0 kcal/mol) is the site of protonation; factors that determine whether protonation occurs at the Ru or the CN- are discussed. C1 Iowa State Univ, Dept Chem, Ames, IA 50011 USA. Iowa State Univ, Ames Lab, Ames, IA 50011 USA. Chinese Acad Sci, Shanghai Inst Organ Chem, Shanghai 200032, Peoples R China. RP Angelici, RJ (reprint author), Iowa State Univ, Dept Chem, Ames, IA 50011 USA. NR 36 TC 21 Z9 21 U1 0 U2 4 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0020-1669 J9 INORG CHEM JI Inorg. Chem. PD APR 20 PY 1998 VL 37 IS 8 BP 1868 EP 1875 DI 10.1021/ic971124o PG 8 WC Chemistry, Inorganic & Nuclear SC Chemistry GA ZJ655 UT WOS:000073238400026 ER PT J AU Huang, BQ Corbett, JD AF Huang, BQ Corbett, JD TI Ba21Ge2O5H24 and related phases. A corrected structure type and composition for a Zintl phase stabilized by hydrogen SO INORGANIC CHEMISTRY LA English DT Article ID POWDER DIFFRACTION PHOTOGRAPHS; ALKALINE-EARTH; DENSITOMETER; CLUSTERS; METALS AB Syntheses of the so-called "suboxide" phases Ba21T2O5 (T = Ge, Si, Ga, In, Tl) are achieved only in the presence of hydrogen. The heavy-atom structure of Ba21Ge2O5H24 at room temperature was redetermined by single-crystal X-ray diffraction and found to be primitive trigonal symmetry (P3(1)21 (No. 152), Z = 6, a = 14.4227(5) Angstrom, c = 35.332(3) Angstrom) instead of the previously refined cubic (Fd (3) over bar m) result. The change greatly improves the heavy-atom parameters. Twenty-four independent deuterium atoms have also been located by time-of-flight neutron diffraction. The structure contains Ba2+ cations, and three different types of monatomic anions, Corresponding to the oxidation states (Ba+2)(21)(Ge-4)(2)(O-2)5(H-)(24). The deuterium atoms occupy tetrahedral, square-pyramidal, and octahedral barium interstices while the oxide anions lie in nearly regular octahedral barium polyhedra. The germanide anions are surrounded by 12 barium atoms in a distorted icosahedral configuration. Property measurements show that Ba(21)Ge(2)O(5)H(24)is diamagnetic and is a semiconductor (or insulator). The analogues Ba21Tr2O5Hx, Tr = Ga, In, Tl, are isotypic with the heavy-atom structure of the title phase and presumably contain 22 hydride ions. C1 Iowa State Univ, US DOE, Ames Lab, Ames, IA 50011 USA. Iowa State Univ, Dept Chem, Ames, IA 50011 USA. RP Corbett, JD (reprint author), Iowa State Univ, US DOE, Ames Lab, Ames, IA 50011 USA. NR 28 TC 30 Z9 30 U1 0 U2 5 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0020-1669 J9 INORG CHEM JI Inorg. Chem. PD APR 20 PY 1998 VL 37 IS 8 BP 1892 EP 1899 DI 10.1021/ic971339y PG 8 WC Chemistry, Inorganic & Nuclear SC Chemistry GA ZJ655 UT WOS:000073238400030 ER PT J AU Borrmann, H Campbell, J Dixon, DA Mercier, HPA Pirani, AM Schrobilgen, GJ AF Borrmann, H Campbell, J Dixon, DA Mercier, HPA Pirani, AM Schrobilgen, GJ TI Tl(2)Ch(2)(2-) (Ch = Se and/or Te) anions: X-ray crystal structures and Raman spectra of (2,2,2-crypt-K+)(2)Tl2Se22- and (2,2,2-crypt-K+)(2)Tl2Te22- and solution Se-77, Tl-203, and Tl-205 NMR spectroscopic and theoretical studies of Tl(2)Ch(2)(2-), In2Se22-, and In2Te22- SO INORGANIC CHEMISTRY LA English DT Article ID POST-TRANSITION-METALS; MULTINUCLEAR MAGNETIC-RESONANCE; ZINTL ANIONS; HETEROPOLYATOMIC ANIONS; HOMOPOLYATOMIC ANIONS; MOLECULAR GEOMETRIES; CHALCOGENIDE ANIONS; BOND ORDERS; SCF THEORY; CHEMISTRY AB The seleno-and tellurothallate(I) anions Tl(2)Ch(2)(2-)(Ch = Se and/or Te) and the Se-77-enriched Tl2Se22- anion have been obtained by extraction of the alloys MTlCh (M = Na, K; Ch = Se, Te), KTlSe0.5Te0.5, and Se-77-enriched KTlSe in ethylenediamine and liquid NH3 and in the presence of a stoichiometric excess of 2,2,2-crypt with respect to M+. The butterfly-shaped Tl(2)Ch(2)(2-)anions were characterized in solution by Se-77, Tl-203 and Tl-305 NMR spectroscopy, Raman spectroscopy, and X-ray crystallography in (2,2.2-crypt K+)(2)Tl(2)Ch(2)(2-); The energy minimized structures of the Tl(2)Ch(2)(2-)(Ch = Se and/or Te) anions were calculated by using density functional theory calculations confirming the nonplanar geometries of all three anions, which are compared with those of the presently unknown In(2)Ch(2-) (Ch = Se, Te) anions. The magnitudes of the relativistically corrected reduced coupling constants, (KTl-Ch)(RC) are consistent with essentially pure p-bonded rings whereas the magnitudes of (KTl-Tl)(RC) suggest significant s electron density along the Tl ... Tl axes and is confirmed by theory. Density functional theory calculations were also used to assign the solid-state vibrational spectra of Tl2Se22- and Tl2Te2-. The variation of the Tl-205-Tl-203 spin-spin coupling constants with solvent and temperature, the differences between the calculated and experimentally determined fold angles, and the low experimental and calculated vibrational frequencies of the anion deformation modes indicate that the anion geometries are significantly influenced by environmental factors. C1 Max Planck Inst Festkorperforsch, D-70569 Stuttgart, Germany. McMaster Univ, Dept Chem, Hamilton, ON L8S 4M1, Canada. Pacific NW Natl Lab, William R wiley Environm Mol Sci Lab, Richland, WA 99352 USA. RP Max Planck Inst Festkorperforsch, Heisenbergstr 1, D-70569 Stuttgart, Germany. NR 62 TC 12 Z9 12 U1 1 U2 2 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0020-1669 EI 1520-510X J9 INORG CHEM JI Inorg. Chem. PD APR 20 PY 1998 VL 37 IS 8 BP 1929 EP 1943 DI 10.1021/ic9710465 PG 15 WC Chemistry, Inorganic & Nuclear SC Chemistry GA ZJ655 UT WOS:000073238400035 ER PT J AU Song, XZ Jaquinod, L Jentzen, W Nurco, DJ Jia, SL Khoury, RG Ma, JG Medforth, CJ Smith, KM Shelnutt, JA AF Song, XZ Jaquinod, L Jentzen, W Nurco, DJ Jia, SL Khoury, RG Ma, JG Medforth, CJ Smith, KM Shelnutt, JA TI Metal dependence of the contributions of low-frequency normal coordinates to the sterically induced distortions of meso-dialkyl-substituted porphyrins SO INORGANIC CHEMISTRY LA English DT Article ID RESONANCE RAMAN-SPECTROSCOPY; LIGHT-ABSORPTION PROPERTIES; BASKET-HANDLE PORPHYRINS; MOLECULAR MECHANICS; FORCE-FIELD; NICKEL(II) OCTAETHYLPORPHYRIN; PHOTOSYNTHETIC CHROMOPHORES; NONPLANAR DISTORTION; ISOTOPE SHIFTS; CYTOCHROMES-C AB The influence of central metals of different sizes on the macrocyclic structure of a series of 5,15-disubstituted metalloporphyrins has been investigated with X-ray crystallography, molecular mechanics (MM) calculations, and resonance Raman spectroscopy. MM calculations indicate that the series of porphyrins are ina gabled (gab) conformation consisting of a linear combination of ruf (B-1u) and dam (A(2u)) out-of-plane normal-coordinate deformation types. The MM-calculated gab structures have been structurally decomposed into equivalent displacements along the lowest-frequency normal coordinate of each symmetry type. The contributions of each normal coordinate to the total distortion agree well with the contributions obtained from normal-coordinate structural decomposition of the X-ray crystal structures. Symmetry considerations show that any relative proportion of the ruf and dom deformations is allowed in the gab distortion. Varying the size of the central metal causes a change in the ratio of the dom/ruf contributions. A large metal like zinc disfavors ruffling over doming, significantly reducing the ruffling contribution and slightly increasing the doming contribution. In addition, the total degree of nonplanar distortion is reduced for large metals. This is confirmed for the series of disubstituted metalloporphyrins by smaller downshifts of the structure-sensitive Raman lines for the larger metals. C1 Sandia Natl Labs, Mat Theory & Computat Dept, Albuquerque, NM 87185 USA. Univ New Mexico, Dept Chem, Albuquerque, NM 87131 USA. Univ Calif Davis, Dept Chem, Davis, CA 95616 USA. RP Sandia Natl Labs, Mat Theory & Computat Dept, POB 5800, Albuquerque, NM 87185 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 62 TC 39 Z9 39 U1 2 U2 4 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0020-1669 EI 1520-510X J9 INORG CHEM JI Inorg. Chem. PD APR 20 PY 1998 VL 37 IS 8 BP 2009 EP 2019 DI 10.1021/ic970465z PG 11 WC Chemistry, Inorganic & Nuclear SC Chemistry GA ZJ655 UT WOS:000073238400045 ER PT J AU de Belle, I Cai, ST Kohwi-Shigematsu, T AF de Belle, I Cai, ST Kohwi-Shigematsu, T TI The genomic sequences bound to special AT-rich sequence-binding protein 1 (SATB1) in vivo in Jurkat T cells are tightly associated with the nuclear matrix at the bases of the chromatin loops SO JOURNAL OF CELL BIOLOGY LA English DT Article ID HOMOPURINE-HOMOPYRIMIDINE SEQUENCES; SUPERCOILED PLASMID DNA; ATTACHMENT REGIONS; DROSOPHILA-MELANOGASTER; CPG ISLANDS; GENE; ORGANIZATION; SCAFFOLD; ENHANCER; SITES AB Special AT-rich sequence-binding protein 1 (SATB1), a DNA-binding protein expressed predominantly in thymocytes, recognizes an ATC sequence context that consists of a cluster of sequence stretches with well-mixed A's, T's, and C's without Cr's on one strand. Such regions confer a high propensity for stable base unpairing. Using an in vivo cross-linking strategy, specialized genomic sequences (0.1-1.1 kbp) that bind to SATB1 in human lymphoblastic cell line Jurkat cells were individually Isolated and characterized. All in vivo SATB1-binding sequences examined contained typical ATC sequence contexts, with some exhibiting homology to autonomously replicating sequences from the yeast Saccharomyces cerevisiae that function as replication origins in yeast cells. In addition, LINE 1 elements, satellite 2 sequences, and CpG island-containing DNA were identified. To examine the higher-order packaging of these in vivo SATB1-binding sequences, high-resolution in situ fluorescence hybridization was performed with both nuclear "halos" with distended loops and the nuclear matrix after the majority of DNA had been removed by nuclease digestion. In vivo SATB1-binding sequences hybridized to genomic DNA as single spots within the residual nucleus circumscribed by the halo of DNA and remained as single spots in the nuclear matrix, indicating that these sequences are localized at the base of chromatin loops. In human breast cancer SK-BR-3 cells that do not express SATB1, at least one such sequence was found not anchored onto the nuclear matrix. These findings provide the first evidence that a cell type-specific factor such as SATB1 binds to the base of chromatin loops in vivo and suggests that a specific chromatin loop domain structure is involved in T cell-specific gene regulation. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Div Life Sci, Berkeley, CA 94720 USA. RP Kohwi-Shigematsu, T (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Div Life Sci, 1 Cyclotron Rd 70A-1118, Berkeley, CA 94720 USA. EM terumiks@lbl.gov FU NCI NIH HHS [R37 CA039681, R01 CA39681, R01 CA039681] NR 79 TC 116 Z9 118 U1 0 U2 1 PU ROCKEFELLER UNIV PRESS PI NEW YORK PA 1114 FIRST AVE, 4TH FL, NEW YORK, NY 10021 USA SN 0021-9525 J9 J CELL BIOL JI J. Cell Biol. PD APR 20 PY 1998 VL 141 IS 2 BP 335 EP 348 DI 10.1083/jcb.141.2.335 PG 14 WC Cell Biology SC Cell Biology GA ZK156 UT WOS:000073291000003 PM 9548713 ER PT J AU Sachsenberg, N Perelson, AS Yerly, S Schockmel, GA Leduc, D Hirschel, B Perrin, L AF Sachsenberg, N Perelson, AS Yerly, S Schockmel, GA Leduc, D Hirschel, B Perrin, L TI Turnover of CD4(+) and CD8(+) T lymphocytes in HIV-1 infection as measured by Ki-67 antigen SO JOURNAL OF EXPERIMENTAL MEDICINE LA English DT Article ID IMMUNODEFICIENCY-VIRUS TYPE-1; MONOCLONAL-ANTIBODY KI-67; NUCLEAR ANTIGEN; RAPID TURNOVER; IN-VIVO; CELLS; MEMORY; ACTIVATION; EXPRESSION; APOPTOSIS AB We investigated CD4(+) and CD8(+) T cell turnover in both healthy and HIV-1-infected adults by measuring the nuclear antigen Ki-67 specific for cell proliferation. The mean growth fraction, corresponding to the expression of Ki-67, was 1.1% for CD4(+) T cells and 1.0% in CD8(+) T cells in healthy adults, and 6.5 and 4.3% in HIV-1-infected individuals, respectively. Analysis of CD45RA(+) and CD45RO(+) T cell subsets revealed a selective expansion of the CD8(+) CD45RO(+) subset in HIV-1-positive individuals. On the basis of the growth fraction, we derived the potential doubling time and the daily turnover of CD4(+) and CD8(+) T cells. In HIV-1-infected individuals, the mean potential doubling time of T cells was five times shorter than that of healthy adults. The mean daily turnover of CD4(+) and CD8(+) T cells in HIV-1-infected individuals was increased 2- and 6-fold, respectively, with more than 40-fold interindividual variation. In patients with <200 CD4(+) counts, CD4(+) turnover dropped markedly, whereas CD8(+) turnover remained elevated. The large variations in CD4(+) T cell turnover might be relevant to individual differences in disease progression. C1 Univ Hosp Geneva, Div Infect Dis, Virol Lab, CH-1211 Geneva 14, Switzerland. Univ Hosp Geneva, Div Infect Dis, AIDS Ctr, CH-1211 Geneva, Switzerland. Ambilly Hosp, F-74100 Annemasse, France. Univ Calif Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. RP Perrin, L (reprint author), Univ Hosp Geneva, Div Infect Dis, Virol Lab, CH-1211 Geneva 14, Switzerland. EM luc.perrin@hcuge.ch FU NCRR NIH HHS [RR-06555, R01 RR006555] NR 41 TC 240 Z9 241 U1 0 U2 8 PU ROCKEFELLER UNIV PRESS PI NEW YORK PA 1114 FIRST AVE, 4TH FL, NEW YORK, NY 10021 USA SN 0022-1007 J9 J EXP MED JI J. Exp. Med. PD APR 20 PY 1998 VL 187 IS 8 BP 1295 EP 1303 DI 10.1084/jem.187.8.1295 PG 9 WC Immunology; Medicine, Research & Experimental SC Immunology; Research & Experimental Medicine GA ZK126 UT WOS:000073287900013 PM 9547340 ER PT J AU Bitterwolf, TE Gallagher, S Bays, JT Scallorn, B Rheingold, AL Guzei, IA Liable-Sands, L Linehan, JC AF Bitterwolf, TE Gallagher, S Bays, JT Scallorn, B Rheingold, AL Guzei, IA Liable-Sands, L Linehan, JC TI Improved synthesis of (eta(5)-CpR)M(CO)(4) compounds and the Nujol matrix photochemistry of (eta(5)-C5H5)M(CO)(4) and (eta(5)-C9H7)M(CO)(4), where M = Nb and Ta SO JOURNAL OF ORGANOMETALLIC CHEMISTRY LA English DT Article; Proceedings Paper CT Symposium on Frontiers in Organometallic Chemistry, Held in Conjunction with the 213th National Meeting of the American-Chemical-Society CY APR 13, 1997 CL SAN FRANCISCO, CALIFORNIA SP Amer Chem Soc DE photochemistry; niobium; tantalum ID CA 12-K; DERIVATIVES; COMPLEXES; NMR; (ETA5-C5H5)NB(CO)4; NIOBIUM; SPECTRA AB Improved preparative routes for cyclopentadienyl (Cp) and substituted Cp(CO)(4) derivatives of niobium and tantalum and their precursors are described. New compounds are fully characterized by IR, NMR, and elemental analysis. The molecular structures of five compounds were determined: (vinylCp)Nb(CO)(4): triclinic, P (1) over bar, a = 6.770(1) Angstrom, b = 6.937(1) Angstrom, c = 12.706(2) Angstrom, alpha = 90.42(1) Angstrom, beta = 91.07(1)degrees, gamma = 105,560(8)degrees, V = 574.71(12) Angstrom(3), Z = 2, R(F) = 2.82; (acetylCp)Nb(CO)(4): monoclinic, P2(1)/c, a = 10.316(2) Angstrom, b = 14.490(3) Angstrom, c = 7.957(3) Angstrom, beta = 94.68(2)degrees, V = 1185.4(4) Angstrom(3), Z = 4, R(F) = 2.58; (Cp)Ta(CO)(4): orthorhombic, Pnma, a = 7.756(1) Angstrom, b = 12.159(2) Angstrom, c = 10.580(1) Angstrom, V = 997.7(2) Angstrom(3), Z = 4, R(F) = 2.60; (indenyl)Ta(CO)(4): monoclinic, P2(1)/n, a = 6.602(2) Angstrom, b = 12.399(1) Angstrom, c = 7.4775(9) Angstrom, beta = 92.05(2)degrees, V = 611.2(2) Angstrom(3), Z = 2, R(F) = 3.05; and (benzoylCp)Ta(CO)(4): monoclinic, P2(1)/c, a = 12.552(10) Angstrom, b = 6.5247(2) Angstrom, c = 18.4682(2) Angstrom, beta = 98.9152(4)degrees, V = 1494.24(5) Angstrom(3), Z = 4, RF) = 2.83 are reported. Photolysis of CpMCO)(4) and indenyl)MCO)(4), where M = Nb and Ta, in Nujol glass matrices were found to result in loss of one to three CO ligands as a function of the wavelength of the incident light. Annealing or reverse photolysis resulted in reversal of these CO-loss reactions. (C) 1998 Elsevier Science S.A. All rights reserved. C1 Univ Idaho, Dept Chem, Moscow, ID 83844 USA. Univ Delaware, Dept Chem, Newark, DE 19716 USA. Pacific NW Lab, Richland, WA 99352 USA. RP Bitterwolf, TE (reprint author), Univ Idaho, Dept Chem, Moscow, ID 83844 USA. EM bitterte@uidaho.edu NR 26 TC 14 Z9 14 U1 0 U2 3 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0022-328X J9 J ORGANOMET CHEM JI J. Organomet. Chem. PD APR 20 PY 1998 VL 557 IS 1 BP 77 EP 92 DI 10.1016/S0022-328X(97)00735-3 PG 16 WC Chemistry, Inorganic & Nuclear; Chemistry, Organic SC Chemistry GA ZQ322 UT WOS:000073846900007 ER PT J AU Carpenter, JP Lukehart, CM Milne, SB Stock, SR Wittig, JE Jones, BD Glosser, R Zhu, JG AF Carpenter, JP Lukehart, CM Milne, SB Stock, SR Wittig, JE Jones, BD Glosser, R Zhu, JG TI Organometallic compounds as single-source precursors to nanocomposite materials: an overview SO JOURNAL OF ORGANOMETALLIC CHEMISTRY LA English DT Article; Proceedings Paper CT Symposium on Frontiers in Organometallic Chemistry, Held in Conjunction with the 213th National Meeting of the American-Chemical-Society CY APR 13, 1997 CL SAN FRANCISCO, CALIFORNIA SP Amer Chem Soc DE nanocomposites; nanoparticles; silica xerogels; sol-gel chemistry ID NONLINEAR-OPTICAL-PROPERTIES; SEMICONDUCTOR CLUSTERS; SOLID-STATE; COMPLEXES; CATALYSIS; CHEMISTRY; MOLECULES; PARTICLES; COLLOIDS AB Molecularly doped silica xerogels are prepared by adding either main-group or transition metal organometallic compounds containing bifunctional ligands to conventional sol-gel formulations. These bifunctional ligands contain distal (alkoxy or hydroxy)silyl groups, so that the dopant molecules become covalently incorporated into the silica xerogel matrix as it is being formed. Subsequent thermal treatment under reducing or oxidizing-then-reducing conditions leads to the decomposition of molecular precursor and to the formation of a nanoparticulate material with precise stoichiometry highly dispersed throughout the xerogel matrix. (C) 1998 Elsevier Science S.A. All rights reserved. C1 Vanderbilt Univ, Dept Chem, Nashville, TN 37235 USA. Georgia Inst Technol, Sch Mat Sci & Engn, Atlanta, GA 30332 USA. Vanderbilt Univ, Dept Appl & Engn Sci, Nashville, TN 37235 USA. Univ Texas, Dept Phys, Richardson, TX 75083 USA. Oak Ridge Natl Lab, Div Solid State, Oak Ridge, TN 37831 USA. RP Lukehart, CM (reprint author), Vanderbilt Univ, Dept Chem, Box 1583, Nashville, TN 37235 USA. NR 38 TC 21 Z9 22 U1 0 U2 6 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0022-328X J9 J ORGANOMET CHEM JI J. Organomet. Chem. PD APR 20 PY 1998 VL 557 IS 1 BP 121 EP 130 DI 10.1016/S0022-328X(97)00740-7 PG 10 WC Chemistry, Inorganic & Nuclear; Chemistry, Organic SC Chemistry GA ZQ322 UT WOS:000073846900012 ER PT J AU Kohara, S Badyal, YS Koura, N Idemoto, Y Takahashi, S Curtiss, LA Saboungi, ML AF Kohara, S Badyal, YS Koura, N Idemoto, Y Takahashi, S Curtiss, LA Saboungi, ML TI The structure of molten alkali carbonates studied by neutron diffraction and ab initio calculations SO JOURNAL OF PHYSICS-CONDENSED MATTER LA English DT Article ID MOLECULAR-DYNAMICS SIMULATION; BINARY-MIXTURES AB The total structure factors, S(Q), of pure molten Li2CO3 and an equimolar mixture with K2CO3. LiKCO3, were measured by neutron diffraction at 1013 it and 923 K, respectively. The results are generally consistent with the findings of previous MD simulations. The CO32- ion remains essentially unperturbed in the mixture. The real-space pair correlation functions are consistent with a close-packed, regular, planar, trigonal geometry for the CO32- ion in both Li2CO3 and LiKCO3. There is some indication, also consistent with the findings of MD simulation, of a possible tightening of the local coordination of CO32- ions around Li+ in the presence of the larger, more weakly polarizing K+ cation. Modelling the S(Q) data using structure factors calculated from monomer and dimer structures derived from ab initio quantum chemical calculations suggests that larger clusters are needed to realistically describe the melt local structure. C1 Argonne Natl Lab, Argonne, IL 60439 USA. RP Kohara, S (reprint author), Sci Univ Tokyo, Fac Sci & Technol, Dept Ind Chem, 2641 Yamazaki, Noda, Chiba 278, Japan. RI Saboungi, Marie-Louise/C-5920-2013 OI Saboungi, Marie-Louise/0000-0002-0607-4815 NR 10 TC 9 Z9 9 U1 1 U2 19 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0953-8984 J9 J PHYS-CONDENS MAT JI J. Phys.-Condes. Matter PD APR 20 PY 1998 VL 10 IS 15 BP 3301 EP 3308 DI 10.1088/0953-8984/10/15/007 PG 8 WC Physics, Condensed Matter SC Physics GA ZK494 UT WOS:000073327500007 ER PT J AU Vo, NV Willis, JO Peterson, DE Liu, HK Dou, SX AF Vo, NV Willis, JO Peterson, DE Liu, HK Dou, SX TI Optimization on processing parameters for Bi(Pb)-2223 superconducting tapes SO PHYSICA C LA English DT Article DE Bi(Pb)-2223 superconducting tapes; optimization; processing parameters ID BI-(PB)-SR-CA-CU-O TAPES; ELECTRICAL-TRANSPORT; SINTERING PERIODS; CURRENT-DENSITY; MICROSTRUCTURE AB Although there exists a large variety of thermo-mechanical procedures for preparing Bi(Pb)-2223/Ag tapes, primarily because of variation in precursor characteristics, the fabrication of long length Bi(Pb)-2223/Ag high-temperature-superconductors (HTSC) whether single-(SF) or multi-filamentary (MF) tapes, still requires the finesse of an optimizational approach on processing parameters, such as heat treatment, mechanical deformation, filament design, cladding materials and so on, to maximize the engineering critical current density (J(e)) and ultimately improve high field performance for applications. An outline for the small-scale processing of short-and lone-length HTSC SF and MF Bi(Pb)-2223/Ag tapes addresses these issues. (C) 1998 Elsevier Science B.V. C1 Univ Calif Los Alamos Natl Lab, Superconduct Technol Ctr, Los Alamos, NM 87545 USA. Univ Wollongong, Inst Mat Technol & Mfg, Ctr Superconducting & Elect Mat, Wollongong, NSW 2522, Australia. RP Vo, NV (reprint author), Univ Calif Los Alamos Natl Lab, Superconduct Technol Ctr, MS-G755, Los Alamos, NM 87545 USA. RI Gupta, Vishnu/B-9839-2009; Dou, Shi Xue/D-5179-2012; ayyadevara, rajaram/D-1572-2009; Liu, Hua Kun/G-1349-2012 OI Dou, Shi Xue/0000-0003-3824-7693; Liu, Hua Kun/0000-0002-0253-647X NR 19 TC 17 Z9 17 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4534 J9 PHYSICA C JI Physica C PD APR 20 PY 1998 VL 299 IS 3-4 BP 315 EP 326 DI 10.1016/S0921-4534(97)01885-6 PG 12 WC Physics, Applied SC Physics GA ZQ920 UT WOS:000073916300017 ER PT J AU Godang, R Kinoshita, K Lai, IC Pomianowski, P Schrenk, S Bonvicini, G Cinabro, D Greene, R Perera, LP Zhou, GJ Chadha, M Chan, S Eigen, G Miller, JS O'Grady, C Schmidtler, M Urheim, J Weinstein, AJ Wurthwein, F Bliss, DW Masek, G Paar, HP Prell, S Sharma, V Asner, DM Gronberg, J Hill, TS Lange, DJ Morrison, RJ Nelson, HN Nelson, TK Roberts, D Ryd, A Balest, R Behrens, BH Ford, WT Gritsan, A Park, H Roy, J Smith, JG Alexander, JP Baker, R Bebek, C Berger, BE Berkelman, K Bloom, K Boisvert, V Cassel, DG Crowcroft, DS Dickson, M von Dombrowski, S Drell, PS Ecklund, KM Ehrlich, R Foland, AD Gaidarev, P Galik, RS Gibbons, L Gittelman, B Gray, SW Hartill, DL Heltsley, BK Hopman, PI Kandaswamy, J Kim, PC Kreinick, DL Lee, T Liu, Y Mistry, NB Ng, CR Nordberg, E Ogg, M Patterson, JR Peterson, D Riley, D Soffer, A Valant-Spaight, B Ward, C Athanas, M Avery, P Jones, CD Lohner, M Patton, S Prescott, C Yelton, J Zheng, J Brandenburg, G Briere, RA Ershov, A Gao, YS Kim, DYJ Wilson, R Yamamoto, H Browder, TE Li, Y Rodriguez, JL Bergfeld, T Eisenstein, BI Ernst, J Gladding, GE Gollin, GD Hans, RM Johnson, E Karliner, I Marsh, MA Palmer, M Selen, M Thaler, JJ Edwards, KW Bellerive, A Janicek, R MacFarlane, DB Patel, PM Sadoff, AJ Ammar, R Baringer, P Bean, A Besson, D Coppage, D Darling, C Davis, R Kotov, S Kravchenko, I Kwak, N Zhou, L Anderson, S Kubota, Y Lee, SJ O'Neill, JJ Poling, R Riehle, T Smith, A Alam, MS Athar, SB Ling, Z Mahmood, AH Timm, S Wappler, F Anastassov, A Duboscq, JE Fujino, D Gan, KK Hart, T Honscheid, K Kagan, H Kass, R Lee, J Spencer, MB Sung, M Undrus, A Wanke, R Wolf, A Zoeller, MM Nemati, B Richichi, SJ Ross, WR Severini, H Skubic, P Bishai, M Fast, J Hinson, JW Menon, N Miller, DH Shibata, EI Shipsey, IPJ Yurko, M Glenn, S Johnson, SD Kwon, Y Roberts, S Thorndike, EH Jessop, CP Lingel, K Marsiske, H Perl, ML Savinov, V Ugolini, D Wang, R Zhou, X Coan, TE Fadeyev, V Korolkov, I Maravin, Y Narsky, I Shelkov, V Staeck, J Stroynowski, R Volobouev, I Ye, J Artuso, M Azfar, F Efimov, A Goldberg, M He, D Kopp, S Moneti, GC Mountain, R Schuh, S Skwarnicki, T Stone, S Viehhauser, G Xing, X Bartelt, J Csorna, SE Jain, V McLean, KW Marka, S AF Godang, R Kinoshita, K Lai, IC Pomianowski, P Schrenk, S Bonvicini, G Cinabro, D Greene, R Perera, LP Zhou, GJ Chadha, M Chan, S Eigen, G Miller, JS O'Grady, C Schmidtler, M Urheim, J Weinstein, AJ Wurthwein, F Bliss, DW Masek, G Paar, HP Prell, S Sharma, V Asner, DM Gronberg, J Hill, TS Lange, DJ Morrison, RJ Nelson, HN Nelson, TK Roberts, D Ryd, A Balest, R Behrens, BH Ford, WT Gritsan, A Park, H Roy, J Smith, JG Alexander, JP Baker, R Bebek, C Berger, BE Berkelman, K Bloom, K Boisvert, V Cassel, DG Crowcroft, DS Dickson, M von Dombrowski, S Drell, PS Ecklund, KM Ehrlich, R Foland, AD Gaidarev, P Galik, RS Gibbons, L Gittelman, B Gray, SW Hartill, DL Heltsley, BK Hopman, PI Kandaswamy, J Kim, PC Kreinick, DL Lee, T Liu, Y Mistry, NB Ng, CR Nordberg, E Ogg, M Patterson, JR Peterson, D Riley, D Soffer, A Valant-Spaight, B Ward, C Athanas, M Avery, P Jones, CD Lohner, M Patton, S Prescott, C Yelton, J Zheng, J Brandenburg, G Briere, RA Ershov, A Gao, YS Kim, DYJ Wilson, R Yamamoto, H Browder, TE Li, Y Rodriguez, JL Bergfeld, T Eisenstein, BI Ernst, J Gladding, GE Gollin, GD Hans, RM Johnson, E Karliner, I Marsh, MA Palmer, M Selen, M Thaler, JJ Edwards, KW Bellerive, A Janicek, R MacFarlane, DB Patel, PM Sadoff, AJ Ammar, R Baringer, P Bean, A Besson, D Coppage, D Darling, C Davis, R Kotov, S Kravchenko, I Kwak, N Zhou, L Anderson, S Kubota, Y Lee, SJ O'Neill, JJ Poling, R Riehle, T Smith, A Alam, MS Athar, SB Ling, Z Mahmood, AH Timm, S Wappler, F Anastassov, A Duboscq, JE Fujino, D Gan, KK Hart, T Honscheid, K Kagan, H Kass, R Lee, J Spencer, MB Sung, M Undrus, A Wanke, R Wolf, A Zoeller, MM Nemati, B Richichi, SJ Ross, WR Severini, H Skubic, P Bishai, M Fast, J Hinson, JW Menon, N Miller, DH Shibata, EI Shipsey, IPJ Yurko, M Glenn, S Johnson, SD Kwon, Y Roberts, S Thorndike, EH Jessop, CP Lingel, K Marsiske, H Perl, ML Savinov, V Ugolini, D Wang, R Zhou, X Coan, TE Fadeyev, V Korolkov, I Maravin, Y Narsky, I Shelkov, V Staeck, J Stroynowski, R Volobouev, I Ye, J Artuso, M Azfar, F Efimov, A Goldberg, M He, D Kopp, S Moneti, GC Mountain, R Schuh, S Skwarnicki, T Stone, S Viehhauser, G Xing, X Bartelt, J Csorna, SE Jain, V McLean, KW Marka, S CA CLEO Collaboration TI Observation of exclusive two-body B decays to kaons and pions SO PHYSICAL REVIEW LETTERS LA English DT Article ID CP ASYMMETRIES; PI-K; MESONS; SEARCH; ELECTROWEAK; DETECTOR AB We have studied two-body charmless hadronic decays of B mesons into the final states pi pi, K pi and KK. Using 3.3 x 10(6) B (B) over bar pairs collected with the CLEO-II detector, we have made the first observation of the decay B-0 --> K(+)pi(-), the sum of B+ --> pi(+)pi(0) and B+ --> K(+)pi(0) decays, and see strong evidence for the decay B+ --> K-0 pi(+) (an average over charge-conjugate states is always implied). We place upper limits on branching fractions for the remaining decay modes. C1 Virginia Polytech Inst & State Univ, Blacksburg, VA 24061 USA. Wayne State Univ, Detroit, MI 48202 USA. CALTECH, Pasadena, CA 91125 USA. Univ Calif San Diego, La Jolla, CA 92093 USA. Univ Calif Santa Barbara, Santa Barbara, CA 93106 USA. Univ Colorado, Boulder, CO 80309 USA. Cornell Univ, Ithaca, NY 14853 USA. Univ Florida, Gainesville, FL 32611 USA. Harvard Univ, Cambridge, MA 02138 USA. Univ Hawaii Manoa, Honolulu, HI 96822 USA. Univ Illinois, Urbana, IL 61801 USA. Carleton Univ, Ottawa, ON K1S 5B6, Canada. Inst Particle Phys, Montreal, PQ, Canada. McGill Univ, Montreal, PQ, Canada. Ithaca Coll, Ithaca, NY 14850 USA. Univ Kansas, Lawrence, KS 66045 USA. Univ Minnesota, Minneapolis, MN 55455 USA. SUNY Albany, Albany, NY 12222 USA. Ohio State Univ, Columbus, OH 43210 USA. Univ Oklahoma, Norman, OK 73019 USA. Purdue Univ, W Lafayette, IN 47907 USA. Univ Rochester, Rochester, NY 14627 USA. Stanford Univ, Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. So Methodist Univ, Dallas, TX 75275 USA. Syracuse Univ, Syracuse, NY 13244 USA. Vanderbilt Univ, Nashville, TN 37235 USA. Univ Texas, Austin, TX 78712 USA. Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. BINP, RU-630090 Novosibirsk, Russia. Yonsei Univ, Seoul 120749, South Korea. Brookhaven Natl Lab, Upton, NY 11973 USA. RP Godang, R (reprint author), Virginia Polytech Inst & State Univ, Blacksburg, VA 24061 USA. RI Briere, Roy/N-7819-2014; OI Briere, Roy/0000-0001-5229-1039; Bean, Alice/0000-0001-5967-8674 NR 24 TC 73 Z9 73 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 APR 20 PY 1998 VL 80 IS 16 BP 3456 EP 3460 DI 10.1103/PhysRevLett.80.3456 PG 5 WC Physics, Multidisciplinary SC Physics GA ZJ325 UT WOS:000073202700010 ER PT J AU Abe, F Akimoto, H Akopian, A Albrow, MG Amadon, A Amendolia, SR Amidei, D Antos, J Aota, S Apollinari, G Arisawa, T Asakawa, T Ashmanskas, W Atac, M Azzi-Bacchetta, P Bacchetta, N Bagdasarov, S Bailey, MW de Barbaro, P Barbaro-Galtieri, A Barnes, VE Barnett, BA Barone, M Bauer, G Baumann, T Bedeschi, F Behrends, S Belforte, S Bellettini, G Bellinger, J Benjamin, D Bensinger, J Beretvas, A Berge, JP Berryhill, J Bertolucci, S Bettelli, S Bevensee, B Bhatti, A Biery, K Bigongiari, C Binkley, M Bisello, D Blair, RE Blocker, C Blusk, S Bodek, A Bokhari, W Bolla, G Bonushkin, Y Bortoletto, D Boudreau, J Breccia, L Bromberg, C Bruner, N Brunetti, R Buckley-Geer, E Budd, HS Burkett, K Busetto, G Byon-Wagner, A Byrum, KL Campbell, M Caner, A Carithers, W Carlsmith, D Cassada, J Castro, A Cauz, D Cerri, A Chang, PS Chang, PT Chao, HY Chapman, J Cheng, MT Chertok, M Chiarelli, G Chiou, CN Chlebana, F Christofek, L Chu, ML Cihangir, S Clark, AG Cobal, M Cocca, E Contreras, M Conway, J Cooper, J Cordelli, M Costanzo, D Couyoumtzelis, C Cronin-Hennessy, D Culbertson, R Dagenhart, D Daniels, T DeJongh, F Dell'Agnello, S Dell'Orso, M Demina, R Demortier, L Deninno, M Derwent, PF Devlin, T Dittmann, JR Donati, S Done, J Dorigo, T Eddy, N Einsweiler, K Elias, JE Ely, R Engels, E Erdmann, W Errede, D Errede, S Fan, Q Feild, RG Feng, Z Ferretti, C Fiori, I Flaugher, B Foster, GW Franklin, M Freeman, J Friedman, J Frisch, H Fukui, Y Gadomski, S Galeotti, S Gallinaro, M Ganel, O Garcia-Sciveres, M Garfinkel, AF Gay, C Geer, S Gerdes, DW Giannetti, P Giokaris, N Giromini, P Giusti, G Gold, M Gordon, A Goshaw, AT Gotra, Y Goulianos, K Grassmann, H Groer, L Grosso-Pilcher, C Guillian, G da Costa, JG Guo, RS Haber, C Hafen, E Hahn, SR Hamilton, R Handa, T Handler, R Happacher, F Hara, K Hardman, AD Harris, RM Hartmann, F Hauser, J Hayashi, E Heinrich, J Hao, W Hinrichsen, B Hoffman, KD Hohlmann, M Holck, C Hollebeek, R Holloway, L Huang, Z Huffman, BT Hughes, R Huston, J Huth, J Ikeda, H Incagli, M Incandela, J Introzzi, G Iwai, J Iwata, Y James, E Jensen, H Joshi, U Kajfasz, E Kambara, H Kamon, T Kaneko, T Karr, K Kasha, H Kato, Y Keaffaber, TA Kelley, K Kennedy, RD Kephart, R Kestenbaum, D Khazins, D Kikuchi, T Kim, BJ Kim, HS Kim, SH Kim, YK Kirsch, L Klimenko, S Knoblauch, D Koehn, P Kongeter, A Kondo, K Konigsberg, J Kordas, K Korytov, A Kovacs, E Kowald, W Kroll, J Kruse, M Kuhlmann, SE Kuns, E Kurino, K Kuwabara, T Laasanen, AT Nakano, I Lami, S Lammel, S Lamoureux, JI Lancaster, M Lanzoni, M Latino, G LeCompte, T Leone, S Lewis, JD Limon, P Lindgren, M Liss, TM Liu, JB Liu, YC Lockyer, N Long, O Loomis, C Loreti, M Lucchesi, D Lukens, P Lusin, S Lys, J Maeshima, K Maksimovic, P Mangano, M Mariotti, M Marriner, JP Martin, A Matthews, JAJ Mazzanti, P McIntyre, P Melese, P Menguzzato, M Menzione, A Meschi, E Metzler, S Miao, C Miao, T Michail, G Miller, R Minato, H Miscetti, S Mishina, R Miyashita, S Moggi, N Moore, E Morita, Y Mukherjee, A Muller, T Murat, P Murgia, S Nakada, H Nakano, I Nelson, C Neuberger, D Newman-Holmes, C Ngan, CYP Nodulman, L Oh, SH Ohmoto, T Ohsugi, T Oishi, R Okabe, M Okusawa, T Olsen, J Pagliarone, C Paoletti, R Papadimitriou, V Pappas, SP Parashar, R Parri, A Patrick, J Pauletta, G Paulini, M Perazzo, A Pescara, L Peters, MD Phillips, TJ Piacentino, G Pillai, M Pitts, KT Plunkett, R Pondrom, L Proudfoot, J Ptohos, F Punzi, G Ragan, K Reher, D Reischl, M Ribon, A Rimondi, F Ristori, L Robertson, WJ Rodrigo, T Rolli, S Rosenson, L Roser, R Saab, T Sakumoto, WK Saltzberg, D Sansoni, A Santi, L Sato, H Schlabach, P Schmidt, EE Schmidt, MP Scott, A Scribano, A Segler, S Seidel, S Seiya, Y Semeria, F Shah, T Shapiro, MD Shaw, NM Shepard, PF Shibayama, T Shimojima, M Shochet, M Siegrist, J Sill, A Sinervo, P Singh, P Sliwa, K Smith, C Snider, FD Spalding, J Speer, T Sphicas, P Spinella, F Spiropulu, M Spiegel, L Stanco, L Steele, J Stefanini, A Strohmer, R Strologas, J Strumia, F Stuart, D Sumorok, K Suzuki, J Suzuki, T Takahashi, T Takano, T Takashima, R Takikawa, K Tanaka, M Tannenbaum, B Tartarelli, F Taylor, W Tecchio, M Teng, PK Teramoto, Y Terashi, K Tether, S Theriot, T Thomas, TL Thurman-Keup, R Timko, M Tipton, P Titov, A Tkaczyk, S Toback, D Tollefson, K Tollestrup, A Toyoda, H Trischuk, T de Troconiz, JF Truitt, S Tseng, J Turini, N Uchida, T Ukegawa, F Valls, J van den Brink, SC Vejeik, S Velev, G Vidal, R Vilar, R Vucinic, D Wagner, RG Wagner, RL Wahl, J Wallace, NB Walsh, AM Wang, C Wang, CH Wang, MJ Warburton, A Watanabe, T Watts, T Webb, R Wei, C Wenzel, H Wester, WC Wicklund, AB Wicklund, E Wilkinson, R Williams, HH Wilson, P Winer, BL Winn, D Wolinski, D Wolinski, J Worm, S Wu, X Wyss, J Yagil, A Yao, W Yasuoka, K Yeh, GP Yeh, P Yoh, J Yosef, C Yoshida, T Yu, I Zanetti, A Zetti, F Zucchelli, S AF Abe, F Akimoto, H Akopian, A Albrow, MG Amadon, A Amendolia, SR Amidei, D Antos, J Aota, S Apollinari, G Arisawa, T Asakawa, T Ashmanskas, W Atac, M Azzi-Bacchetta, P Bacchetta, N Bagdasarov, S Bailey, MW de Barbaro, P Barbaro-Galtieri, A Barnes, VE Barnett, BA Barone, M Bauer, G Baumann, T Bedeschi, F Behrends, S Belforte, S Bellettini, G Bellinger, J Benjamin, D Bensinger, J Beretvas, A Berge, JP Berryhill, J Bertolucci, S Bettelli, S Bevensee, B Bhatti, A Biery, K Bigongiari, C Binkley, M Bisello, D Blair, RE Blocker, C Blusk, S Bodek, A Bokhari, W Bolla, G Bonushkin, Y Bortoletto, D Boudreau, J Breccia, L Bromberg, C Bruner, N Brunetti, R Buckley-Geer, E Budd, HS Burkett, K Busetto, G Byon-Wagner, A Byrum, KL Campbell, M Caner, A Carithers, W Carlsmith, D Cassada, J Castro, A Cauz, D Cerri, A Chang, PS Chang, PT Chao, HY Chapman, J Cheng, MT Chertok, M Chiarelli, G Chiou, CN Chlebana, F Christofek, L Chu, ML Cihangir, S Clark, AG Cobal, M Cocca, E Contreras, M Conway, J Cooper, J Cordelli, M Costanzo, D Couyoumtzelis, C Cronin-Hennessy, D Culbertson, R Dagenhart, D Daniels, T DeJongh, F Dell'Agnello, S Dell'Orso, M Demina, R Demortier, L Deninno, M Derwent, PF Devlin, T Dittmann, JR Donati, S Done, J Dorigo, T Eddy, N Einsweiler, K Elias, JE Ely, R Engels, E Erdmann, W Errede, D Errede, S Fan, Q Feild, RG Feng, Z Ferretti, C Fiori, I Flaugher, B Foster, GW Franklin, M Freeman, J Friedman, J Frisch, H Fukui, Y Gadomski, S Galeotti, S Gallinaro, M Ganel, O Garcia-Sciveres, M Garfinkel, AF Gay, C Geer, S Gerdes, DW Giannetti, P Giokaris, N Giromini, P Giusti, G Gold, M Gordon, A Goshaw, AT Gotra, Y Goulianos, K Grassmann, H Groer, L Grosso-Pilcher, C Guillian, G da Costa, JG Guo, RS Haber, C Hafen, E Hahn, SR Hamilton, R Handa, T Handler, R Happacher, F Hara, K Hardman, AD Harris, RM Hartmann, F Hauser, J Hayashi, E Heinrich, J Hao, W Hinrichsen, B Hoffman, KD Hohlmann, M Holck, C Hollebeek, R Holloway, L Huang, Z Huffman, BT Hughes, R Huston, J Huth, J Ikeda, H Incagli, M Incandela, J Introzzi, G Iwai, J Iwata, Y James, E Jensen, H Joshi, U Kajfasz, E Kambara, H Kamon, T Kaneko, T Karr, K Kasha, H Kato, Y Keaffaber, TA Kelley, K Kennedy, RD Kephart, R Kestenbaum, D Khazins, D Kikuchi, T Kim, BJ Kim, HS Kim, SH Kim, YK Kirsch, L Klimenko, S Knoblauch, D Koehn, P Kongeter, A Kondo, K Konigsberg, J Kordas, K Korytov, A Kovacs, E Kowald, W Kroll, J Kruse, M Kuhlmann, SE Kuns, E Kurino, K Kuwabara, T Laasanen, AT Nakano, I Lami, S Lammel, S Lamoureux, JI Lancaster, M Lanzoni, M Latino, G LeCompte, T Leone, S Lewis, JD Limon, P Lindgren, M Liss, TM Liu, JB Liu, YC Lockyer, N Long, O Loomis, C Loreti, M Lucchesi, D Lukens, P Lusin, S Lys, J Maeshima, K Maksimovic, P Mangano, M Mariotti, M Marriner, JP Martin, A Matthews, JAJ Mazzanti, P McIntyre, P Melese, P Menguzzato, M Menzione, A Meschi, E Metzler, S Miao, C Miao, T Michail, G Miller, R Minato, H Miscetti, S Mishina, R Miyashita, S Moggi, N Moore, E Morita, Y Mukherjee, A Muller, T Murat, P Murgia, S Nakada, H Nakano, I Nelson, C Neuberger, D Newman-Holmes, C Ngan, CYP Nodulman, L Oh, SH Ohmoto, T Ohsugi, T Oishi, R Okabe, M Okusawa, T Olsen, J Pagliarone, C Paoletti, R Papadimitriou, V Pappas, SP Parashar, R Parri, A Patrick, J Pauletta, G Paulini, M Perazzo, A Pescara, L Peters, MD Phillips, TJ Piacentino, G Pillai, M Pitts, KT Plunkett, R Pondrom, L Proudfoot, J Ptohos, F Punzi, G Ragan, K Reher, D Reischl, M Ribon, A Rimondi, F Ristori, L Robertson, WJ Rodrigo, T Rolli, S Rosenson, L Roser, R Saab, T Sakumoto, WK Saltzberg, D Sansoni, A Santi, L Sato, H Schlabach, P Schmidt, EE Schmidt, MP Scott, A Scribano, A Segler, S Seidel, S Seiya, Y Semeria, F Shah, T Shapiro, MD Shaw, NM Shepard, PF Shibayama, T Shimojima, M Shochet, M Siegrist, J Sill, A Sinervo, P Singh, P Sliwa, K Smith, C Snider, FD Spalding, J Speer, T Sphicas, P Spinella, F Spiropulu, M Spiegel, L Stanco, L Steele, J Stefanini, A Strohmer, R Strologas, J Strumia, F Stuart, D Sumorok, K Suzuki, J Suzuki, T Takahashi, T Takano, T Takashima, R Takikawa, K Tanaka, M Tannenbaum, B Tartarelli, F Taylor, W Tecchio, M Teng, PK Teramoto, Y Terashi, K Tether, S Theriot, T Thomas, TL Thurman-Keup, R Timko, M Tipton, P Titov, A Tkaczyk, S Toback, D Tollefson, K Tollestrup, A Toyoda, H Trischuk, T de Troconiz, JF Truitt, S Tseng, J Turini, N Uchida, T Ukegawa, F Valls, J van den Brink, SC Vejeik, S Velev, G Vidal, R Vilar, R Vucinic, D Wagner, RG Wagner, RL Wahl, J Wallace, NB Walsh, AM Wang, C Wang, CH Wang, MJ Warburton, A Watanabe, T Watts, T Webb, R Wei, C Wenzel, H Wester, WC Wicklund, AB Wicklund, E Wilkinson, R Williams, HH Wilson, P Winer, BL Winn, D Wolinski, D Wolinski, J Worm, S Wu, X Wyss, J Yagil, A Yao, W Yasuoka, K Yeh, GP Yeh, P Yoh, J Yosef, C Yoshida, T Yu, I Zanetti, A Zetti, F Zucchelli, S CA CDF Collaboration TI Measurement of the differential cross section for events with large total transverse energy in p(p)over-bar collisions at root s=1.8 TeV SO PHYSICAL REVIEW LETTERS LA English DT Article ID PROTON-ANTIPROTON COLLIDER; MASS MULTIJET EVENTS; (P)OVER-BAR-P COLLISIONS; JET PRODUCTION AB We present a measurement of the differential cross section d sigma/d Sigma E-T(jet) for the production of multijet events in p (p) over bar collisions where the sum is over all jets with transverse energy E-T(jet) > E-T(mm). The measured cross section for events with Sigma E-T(jet) > 320 GeV is compared to O(alpha(s)(3)) perturbative QCD predictions and QCD parton shower Monte Carlo preidctions. The agreement between the O(alpha(v)(3)) predicted and observed event rates is reasonable for E-T(min) = 100 GeV, but poorer E-T(mm) = 20 GeV. C1 Kek Nat Lab High Energy Phys, Tsukuba, Ibaraki 305, Japan. Argonne Natl Lab, Argonne, IL 60439 USA. Univ Bologna, Ist Nazl Fis Nucl, I-40127 Bologna, Italy. Brandeis Univ, Waltham, MA 02254 USA. Univ Calif Los Angeles, Los Angeles, CA 90024 USA. Univ Chicago, Chicago, IL 60637 USA. Duke Univ, Durham, NC 27708 USA. Fermilab Natl Accelerator Lab, Batavia, IL 60510 USA. Univ Florida, Gainesville, FL 32611 USA. Ist Nazl Fis Nucl, Lab Nazl Frascati, I-00044 Frascati, Italy. Univ Geneva, CH-1211 Geneva 4, Switzerland. Harvard Univ, Cambridge, MA 02138 USA. Hiroshima Univ, Higashihiroshima 724, Japan. Univ Illinois, Urbana, IL 61801 USA. McGill Univ, Inst Particle Phys, Montreal, PQ H3A 2T8, Canada. Univ Toronto, Toronto, ON M5S 1A7, Canada. Johns Hopkins Univ, Baltimore, MD 21218 USA. Univ Karlsruhe, Inst Expt Kernphys, D-76128 Karlsruhe, Germany. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. MIT, Cambridge, MA 02139 USA. Univ Michigan, Ann Arbor, MI 48109 USA. Michigan State Univ, E Lansing, MI 48824 USA. Univ New Mexico, Albuquerque, NM 87131 USA. Ohio State Univ, Columbus, OH 43210 USA. Osaka City Univ, Osaka 588, Japan. Univ Padua, Ist Nazl Fis Nucl, Sez Padova, I-35131 Padua, Italy. Univ Penn, Philadelphia, PA 19104 USA. Univ Pisa, Ist Nazl Fis Nucl, I-56100 Pisa, Italy. Scuola Normale Super Pisa, I-56100 Pisa, Italy. Univ Pittsburgh, Pittsburgh, PA 15260 USA. Purdue Univ, W Lafayette, IN 47907 USA. Univ Rochester, Rochester, NY 14627 USA. Rockefeller Univ, New York, NY 10021 USA. Rutgers State Univ, Piscataway, NJ 08855 USA. Acad Sinica, Taipei 11530, Taiwan. Texas A&M Univ, College Stn, TX 77843 USA. Texas Tech Univ, Lubbock, TX 79409 USA. Univ Trieste, Ist Nazl Fis Nucl, I-34127 Trieste, Italy. Univ Udine, Ist Nazl Fis Nucl, I-33100 Udine, Italy. Univ Tsukuba, Tsukuba, Ibaraki 315, Japan. Tufts Univ, Medford, MA 02155 USA. Waseda Univ, Tokyo 169, Japan. Univ Wisconsin, Madison, WI 53706 USA. Yale Univ, New Haven, CT 06520 USA. RP Kek Nat Lab High Energy Phys, Tsukuba, Ibaraki 305, Japan. RI Introzzi, Gianluca/K-2497-2015; Lancaster, Mark/C-1693-2008; vilar, rocio/D-7454-2014; Vucinic, Dejan/C-2406-2008; Azzi, Patrizia/H-5404-2012; Punzi, Giovanni/J-4947-2012; Chiarelli, Giorgio/E-8953-2012; Warburton, Andreas/N-8028-2013; Paulini, Manfred/N-7794-2014 OI Introzzi, Gianluca/0000-0002-1314-2580; Azzi, Patrizia/0000-0002-3129-828X; Punzi, Giovanni/0000-0002-8346-9052; Chiarelli, Giorgio/0000-0001-9851-4816; Warburton, Andreas/0000-0002-2298-7315; Paulini, Manfred/0000-0002-6714-5787 NR 16 TC 9 Z9 10 U1 0 U2 0 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 APR 20 PY 1998 VL 80 IS 16 BP 3461 EP 3466 DI 10.1103/PhysRevLett.80.3461 PG 6 WC Physics, Multidisciplinary SC Physics GA ZJ325 UT WOS:000073202700011 ER PT J AU Schlei, BR Strottman, D Xu, N AF Schlei, BR Strottman, D Xu, N TI Equation of state of nuclear matter in 158A GeV Pb+Pb collisions SO PHYSICAL REVIEW LETTERS LA English DT Article ID HYDRODYNAMICS AB Within a hydrodynamical approach lye investigate the sensitivity of single inclusive momentum spectra of hadrons in 158A GeV Pb + Pb collisions to three different equations of state of nuclear matter. The initial conditions before the evolution of the fireballs and the space-time evolution pictures differ dramatically for the three equations of state when the same freeze-out temperature is used in all calculations. However, the softest of the equations of state results in transverse mass spectra that are too steep in the central rapidity region. We conclude that the transverse particle momenta are determined by the effective softness of the equation of state during the fireball expansion. C1 Univ Calif Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Nucl Sci, Berkeley, CA 94720 USA. RP Schlei, BR (reprint author), Univ Calif Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. NR 26 TC 6 Z9 6 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD APR 20 PY 1998 VL 80 IS 16 BP 3467 EP 3470 DI 10.1103/PhysRevLett.80.3467 PG 4 WC Physics, Multidisciplinary SC Physics GA ZJ325 UT WOS:000073202700012 ER PT J AU Schneider, MB Dimonte, G Remington, B AF Schneider, MB Dimonte, G Remington, B TI Large and small scale structure in Rayleigh-Taylor mixing SO PHYSICAL REVIEW LETTERS LA English DT Article ID INSTABILITY; HYDRODYNAMICS; SIMULATION; FUSION; MODE AB Laser-induced fluorescence is used to image the central plane of the mix region of two immiscible liquids subject to the Rayleigh-Taylor instability at an acceleration of 70 times Earth's gravity. The size of the mixing zone grows with coefficient alpha(b) greater than or similar to 0.054. Individual bubbles are clearly resolved and their structure is measured. The widths of the bubbles are narrower than recent models predict. An internal structure in the bubbles appears after the mixing zone is established. This structure suggests a cascade to small wavelengths. The cascade is required for molecular mix. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. RP Schneider, MB (reprint author), Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. NR 35 TC 73 Z9 73 U1 0 U2 14 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD APR 20 PY 1998 VL 80 IS 16 BP 3507 EP 3510 DI 10.1103/PhysRevLett.80.3507 PG 4 WC Physics, Multidisciplinary SC Physics GA ZJ325 UT WOS:000073202700022 ER PT J AU Cho, JH Niu, Q Zhang, ZY AF Cho, JH Niu, Q Zhang, ZY TI Oscillatory nonmetal-metal transitions of ultrathin Sb overlayers on a GaAs(110) substrate SO PHYSICAL REVIEW LETTERS LA English DT Article ID SCANNING TUNNELING MICROSCOPY; ELECTRONIC-STRUCTURE; FILMS; PSEUDOPOTENTIALS; DIFFRACTION; ANTIMONY; SURFACE; DENSITY; SPECTROSCOPY; GROWTH AB Based on first-principles calculations, an Sb film on GaAs(110) is found to be nonmetallic at 1 and 3 monolayer (ML) coverages, and metallic at 2, 4, and higher ML coverages. These unusual oscillatory nonmetal-metal transitions are explained in terms of a generalized Wilson rule, constrained by the relative magnitudes of the separation and width of the: subbands derived from the quantum-well states. The present study also establishes the existence of magic stability of the film at the odd numbers of monolayers, and strong interlayer spacing oscillations. C1 Oak Ridge Natl Lab, Div Solid State, Oak Ridge, TN 37831 USA. Univ Texas, Dept Phys, Austin, TX 78712 USA. Univ Tennessee, Dept Phys, Knoxville, TN USA. RP Oak Ridge Natl Lab, Div Solid State, POB 2008, Oak Ridge, TN 37831 USA. RI Niu, Qian/G-9908-2013; Cho, Jun-Hyung/R-7256-2016 OI Cho, Jun-Hyung/0000-0002-1785-1835 NR 34 TC 22 Z9 22 U1 0 U2 2 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 APR 20 PY 1998 VL 80 IS 16 BP 3582 EP 3585 DI 10.1103/PhysRevLett.80.3582 PG 4 WC Physics, Multidisciplinary SC Physics GA ZJ325 UT WOS:000073202700041 ER PT J AU Zheludev, A Ressouche, E Maslov, S Yokoo, T Raymond, S Akimitsu, J AF Zheludev, A Ressouche, E Maslov, S Yokoo, T Raymond, S Akimitsu, J TI Experimental measurement of the staggered magnetization curve for a Haldane spin chain SO PHYSICAL REVIEW LETTERS LA English DT Article ID 1 ANTIFERROMAGNETIC CHAIN; SOFT-MODE TRANSITION; NEUTRON-SCATTERING; GAP ANTIFERROMAGNET; HEISENBERG CHAIN; FIELD; EXCITATIONS; Y2BANIO5; CSNICL3; NENP AB Long-range magnetic ordering in R2BaNiO5 (R = magnetic rare earth) quasi-one-dimensional mixed-spin antiferromagnets is described by a simple mean-field model that is based on the intrinsic staggered magnetization function of isolated Haldane spin chains for the Ni subsystem, and single-ion magnetization functions for the rare earth ions. The model is applied to new experimental results obtained in powder diffraction experiments on Nd2BaNiO5 and NdYBaNiO5, and to previously published diffraction data for Er2BaNiO5. From this analysis we extract the bare staggered magnetization curve for Haldane spin chains in these compounds. C1 Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. Ctr Etudes Nucl, DRFMC, SPSMS, MDN, F-38054 Grenoble, France. Aoyama Gakuin Univ, Dept Phys, Setagaya Ku, Tokyo 157, Japan. RP Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. RI Maslov, Sergei/C-2397-2009 OI Maslov, Sergei/0000-0002-3701-492X NR 28 TC 47 Z9 49 U1 0 U2 5 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 EI 1079-7114 J9 PHYS REV LETT JI Phys. Rev. Lett. PD APR 20 PY 1998 VL 80 IS 16 BP 3630 EP 3633 DI 10.1103/PhysRevLett.80.3630 PG 4 WC Physics, Multidisciplinary SC Physics GA ZJ325 UT WOS:000073202700053 ER PT J AU Puretzky, AA Geohegan, DB AF Puretzky, AA Geohegan, DB TI Gas-phase diagnostics and LIF-imaging of 3-hydroxypicolinic acid maldi-matrix plumes SO CHEMICAL PHYSICS LETTERS LA English DT Article ID ASSISTED LASER-DESORPTION; IONIZATION MASS-SPECTROMETRY; IONS; DISTRIBUTIONS; SPECTROSCOPY; ABLATION AB The first gated laser induced fluorescence (LIF)-imaging and absorption spectroscopy have been performed on laser desorbed plumes from organic crystals which are commonly used as MALDI !matrix assisted laser desorption ionization) matrices. These plasma diagnostic techniques, and also ion probe measurements, were employed to investigate the desorbed products, densities, fractional ionization and velocity distributions of the plume of 3-hydroxypicolinic acid (3-HPA) under ArF(193 nm)- and KrF(238 nm)-laser irradiation. In both cases, gated LIF imaging using 308 nm excitation revealed two plume components: a fast (maximum similar to 0.1 cm/mu s) low-intensity component which appeal to be 3-HPA fragments, and a slower component of 3-HPA expanding at 0.05 cm/mu s. (C) 1998 Published by Elsevier Science B.V. C1 Oak Ridge Natl Lab, Div Solid State, Oak Ridge, TN 37831 USA. RP Puretzky, AA (reprint author), Oak Ridge Natl Lab, Div Solid State, Oak Ridge, TN 37831 USA. RI Puretzky, Alexander/B-5567-2016; Geohegan, David/D-3599-2013 OI Puretzky, Alexander/0000-0002-9996-4429; Geohegan, David/0000-0003-0273-3139 NR 17 TC 57 Z9 57 U1 0 U2 10 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0009-2614 J9 CHEM PHYS LETT JI Chem. Phys. Lett. PD APR 17 PY 1998 VL 286 IS 5-6 BP 425 EP 432 DI 10.1016/S0009-2614(98)00013-X PG 8 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA ZM713 UT WOS:000073568400011 ER PT J AU Benedict, LX Chopra, NG Cohen, ML Zettl, A Louie, SG Crespi, VH AF Benedict, LX Chopra, NG Cohen, ML Zettl, A Louie, SG Crespi, VH TI Microscopic determination of the interlayer binding energy in graphite SO CHEMICAL PHYSICS LETTERS LA English DT Article ID CARBON NANOTUBES; ENERGETICS; GROWTH AB High-tensile-strength carbon nanotubes an nonetheless susceptible to large radial deformations. In particular, tubes may collapse so that opposing tube walls attain the graphitic interlayer spacing. A simple elastic model shows that the ratio of mean curvature modulus to the interwall attraction of graphite determines the cross-section of a collapsed tube. Transmission electron microscopy of collapsed tubes confirms the elastic model and affords the first microscopic measurement of the strength of the intersheet attraction, a quantity otherwise difficult to assess. (C) 1998 Elsevier Science B.V. C1 Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. Penn State Univ, Dept Phys, Davey Lab 104, University Pk, PA 16802 USA. RP Benedict, LX (reprint author), Natl Inst Stand & Technol, Phys Lab, Opt Technol Div, Gaithersburg, MD 20878 USA. RI Zettl, Alex/O-4925-2016; OI Zettl, Alex/0000-0001-6330-136X; Crespi, Vincent/0000-0003-3846-3193 NR 22 TC 246 Z9 248 U1 5 U2 38 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0009-2614 J9 CHEM PHYS LETT JI Chem. Phys. Lett. PD APR 17 PY 1998 VL 286 IS 5-6 BP 490 EP 496 DI 10.1016/S0009-2614(97)01466-8 PG 7 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA ZM713 UT WOS:000073568400021 ER PT J AU Kapanadze, B Kashuba, V Baranova, A Rasool, O van Everdink, W Liu, Y Syomov, A Corcoran, M Poltaraus, A Brodyansky, V Syomova, N Kazakov, A Ibbotson, R van den Berg, A Gizatullin, R Fedorova, L Sulimova, G Zelenin, A Deaven, L Lehrach, H Grander, D Buys, C Oscier, D Zabarovsky, ER Einhorn, S Yankovsky, N AF Kapanadze, B Kashuba, V Baranova, A Rasool, O van Everdink, W Liu, Y Syomov, A Corcoran, M Poltaraus, A Brodyansky, V Syomova, N Kazakov, A Ibbotson, R van den Berg, A Gizatullin, R Fedorova, L Sulimova, G Zelenin, A Deaven, L Lehrach, H Grander, D Buys, C Oscier, D Zabarovsky, ER Einhorn, S Yankovsky, N TI A cosmid and cDNA fine physical map of a human chromosome 13q14 region frequently lost in B-cell chronic lymphocytic leukemia and identification of a new putative tumor suppressor gene, Leu5 SO FEBS LETTERS LA English DT Article DE tumor suppressor gene; location; B-cell chronic lymphocytic leukemia; zinc binding; human ID RETINOBLASTOMA GENE; D13S25 LOCUS; LIBRARIES; HUMAN-CHROMOSOME-13; DELETIONS; YEAST AB B-cell chronic lymphocytic leukemia (B-CLL) is a human hematological neoplastic disease often associated with the toss of a chromosome 13 region between RB1 gene and locus D13S25, A new tumor suppressor gene (TSG) may be located in the region. A cosmid contig has been constructed between the Loci D13S1168 (W19598) and D13S25 (H2-42), which corresponds to the minimal region shared by B-CLL associated deletions. The contig includes more than 200 LANL and ICRF cosmid clones covering 620 kb, Three cDNAs likely corresponding to three different genes hare been found in the minimally deleted region, sequenced and mapped against the contigged cosmids, cDNA clone 10k4 as well as a chimeric clone 13g3, codes for a zinc-finger domain of the RING type and shares homology to some known genes involved in tumorigenesis (RET finger protein, BRCA1) and embryogenesis (MID1). We have termed the gene corresponding to 10k4/13g3 clones LEU5, This is the first gene with homology to known TSGs which has been found in the region of B-CLL rearrangements. (C) 1998 Federation of European Biochemical Societies. C1 NI Vavilov Gen Genet Res Inst, Moscow 117809, Russia. Karolinska Hosp, MTC, S-10401 Stockholm, Sweden. Karolinska Hosp, GCR, S-10401 Stockholm, Sweden. Bion Ltd, Moscow 117809, Russia. Karolinska Hosp & Inst, Res Lab Radiumhemmet, Dept Oncol Pathol, S-17176 Stockholm, Sweden. Univ Groningen, NL-9713 AW Groningen, Netherlands. Royal Bournemouth Hosp, Bournemouth BH7 7DW, Dorset, England. Engelhardt Inst Mol Biol, Moscow 117894, Russia. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Max Planck Inst Mol Genet, D-14195 Berlin, Germany. RP Yankovsky, N (reprint author), NI Vavilov Gen Genet Res Inst, Moscow 117809, Russia. EM yankovsky@vigg.ru RI Zabarovsky, Eugene/A-6645-2010; Baranova, Ancha/B-4608-2012; van den Berg, Anke/H-1718-2011 OI Baranova, Ancha/0000-0001-6810-5982; NR 23 TC 54 Z9 55 U1 1 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0014-5793 J9 FEBS LETT JI FEBS Lett. PD APR 17 PY 1998 VL 426 IS 2 BP 266 EP 270 DI 10.1016/S0014-5793(98)00357-3 PG 5 WC Biochemistry & Molecular Biology; Biophysics; Cell Biology SC Biochemistry & Molecular Biology; Biophysics; Cell Biology GA ZK237 UT WOS:000073299100024 PM 9599022 ER PT J AU Khaselev, O Turner, JA AF Khaselev, O Turner, JA TI A monolithic photovoltaic-photoelectrochemical device for hydrogen production via water splitting SO SCIENCE LA English DT Article ID TANDEM SOLAR-CELLS; SEMICONDUCTING PHOTOELECTRODES; EFFICIENCY; OXYGEN AB Direct water electrolysis was achieved with a novel, integrated, monolithic photoelectrochemical-photovoltaic design. This photoelectrochemical cell, which is voltage biased with an integrated photovoltaic device, splits water directly upon illumination; light is the only energy input. The hydrogen production efficiency of this system, based on the short-circuit current and the lower heating value of hydrogen, is 12.4 percent. C1 Natl Renewable Energy Lab, Golden, CO 80401 USA. RP Turner, JA (reprint author), Natl Renewable Energy Lab, 1617 Cole Blvd, Golden, CO 80401 USA. EM jturner@nrel.gov NR 23 TC 1181 Z9 1196 U1 50 U2 606 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 APR 17 PY 1998 VL 280 IS 5362 BP 425 EP 427 DI 10.1126/science.280.5362.425 PG 3 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA ZH907 UT WOS:000073159600044 ER PT J AU Rice, SF Steeper, RR Aiken, JD AF Rice, SF Steeper, RR Aiken, JD TI Water density effects on homogeneous water-gas shift reaction kinetics SO JOURNAL OF PHYSICAL CHEMISTRY A LA English DT Article ID SUPERCRITICAL AQUEOUS-SOLUTIONS; SOLVENT; DILUTE; MIXTURES; SIMULATION AB Several years ago, using ab initio calculations, Melius et al. examined an interesting pathway for the homogeneous gas-phase water-gas shift reaction. They predicted that an enhancement in the rate of this reaction occurs at high water density due to changes in the generation of formic acid as an intermediate. To investigate this possibility, we have examined the conversion of CO and H2O to CO2 and H-2 in the absence of a catalyst in supercritical water at conditions from 410 to 520 degrees C and 2.0-60 MPa. In these experiments, Raman spectroscopy produced in situ, real-time measurements of reaction rates in an optically accessible, constant-volume reactor. The most rapid homogeneous rate measured, at 59 MPa and 450 degrees C, corresponds to an effective first-order reaction rate constant of 0.0033 s(-1). The data show that the measured reaction rates increase far faster than linearly as water density is raised above 0.35 g/cm(3), and the pressure dependence of the rate constant indicates that the transition state is characterized by an unusually high negative volume of activation, Delta upsilon double dagger = -1135 cm(3)/mol. These data provide strong evidence that this is not a simple gas-kinetic bimolecular reaction at conditions in the neighborhood of the critical density. Rather, the participation of extra water molecules in the structure of the transition-state complex results in a high-order rate dependence on water density. The data are analyzed within the context of a transition-state local density enhancement, expressed as a cluster number, xi(ts), found to be approximately 15 molecules. C1 Sandia Natl Labs, Combust Res Facil, Livermore, CA 94551 USA. RP Rice, SF (reprint author), Sandia Natl Labs, Combust Res Facil, MS-9052,POB 969, Livermore, CA 94551 USA. NR 22 TC 60 Z9 60 U1 3 U2 9 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 1089-5639 J9 J PHYS CHEM A JI J. Phys. Chem. A PD APR 16 PY 1998 VL 102 IS 16 BP 2673 EP 2678 DI 10.1021/jp972368x PG 6 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA ZJ966 UT WOS:000073271600006 ER PT J AU Labouriau, A Higley, TJ Earl, WL AF Labouriau, A Higley, TJ Earl, WL TI Chemical shift prediction in the Si-29 MAS NMR of titanosilicates SO JOURNAL OF PHYSICAL CHEMISTRY B LA English DT Article ID NUCLEAR MAGNETIC-RESONANCE; SILICATE MINERAL STRUCTURE; X-RAY-DIFFRACTION; ORTHORHOMBIC FRAMEWORK; ZEOLITE H-ZSM-5; SINGLE-CRYSTAL; CATALYTIC PROPERTIES; TITANIUM SILICALITE; SELECTIVE OXIDATION; MOLECULAR-SIEVES AB We have related the Si-29 MAS NMR chemical shifts of titanosilicates and highly siliceous zeolites linearly with structural factors. Good correlations in titanosilicates were obtained using the model proposed by Sherriff et al., (1,2) where the chemical shift is described in terms of the summation of valence, dipole, and hybridization terms. This empirical correlation provides a basis for semiquantitative interpretation of spectra for titanium-bearing silicates. Our original goal was to understand the lack, of a Si-29 NMR peak assignable to silicon that is next-nearest neighbor to titanium in titanium-containing zeolites. Although the equations and correlations presented work very well for most titanium-containing silicates, we still do not understand the Si-29 MAS NMR spectrum of these zeolites because our results suggest that there should be a distinguishable peak for TS-1 and TS-2. No such peaks are detected in the actual spectra. C1 Univ Calif Los Alamos Natl Lab, Div Chem Sci & Technol, Los Alamos, NM 87545 USA. RP Earl, WL (reprint author), Univ Calif Los Alamos Natl Lab, Div Chem Sci & Technol, Mail Stop J514, Los Alamos, NM 87545 USA. NR 71 TC 39 Z9 40 U1 1 U2 10 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 1089-5647 J9 J PHYS CHEM B JI J. Phys. Chem. B PD APR 16 PY 1998 VL 102 IS 16 BP 2897 EP 2904 DI 10.1021/jp9716703 PG 8 WC Chemistry, Physical SC Chemistry GA ZJ968 UT WOS:000073271800010 ER PT J AU Chaturvedi, S Strongin, DR AF Chaturvedi, S Strongin, DR TI Methanol chemisorption and reaction on the (111) crystallographic plane of NiAl SO JOURNAL OF PHYSICAL CHEMISTRY B LA English DT Article ID STIMULATED DESORPTION; THERMAL-DECOMPOSITION; NI/AL2O3 CATALYSTS; NEUTRAL MOLECULES; SURFACE KINETICS; NI(100) SURFACES; CO METHANATION; METHYL-IODIDE; ADSORPTION; NI(110) AB Thermal chemistry of CH3OH on the (111) crystallographic plane of NiAl has been investigated with temperature-programmed desorption (TPD), synchrotron-based photoelectron spectroscopy, high-resolution electron energy loss spectroscopy (EELS), and X-ray photoelectron spectroscopy (XPS). It is inferred from EELS results that CH3OH, at least in part, adsorbs molecularly at 120 K and completely converts to methoxy, CH3O(ad), by 200 K. Photoelectron spectroscopy indicates that the majority of methoxy binds strongly to the Al component, inducing a 1 eV shift of the Al 2p core level to higher binding energy, relative to the same Al core level of clean NiAl(111). Comparison of EELS results for methoxy on NiAl(110) and NiAl(100) to NiAl(111) opens up the possibility that methoxy adopts ar least two different binding sites on the (111) plane of NiAl. One of these sites has a strong contribution from Ni, and a second site has a lesser contribution from Ni (i.e., "Al-rich" site), and methoxy decomposition on this latter site leads to no oxygenated gaseous product. Thermal decomposition of methoxy results in the production of gaseous H-2, CO, CH4, and CH3 in the temperature range 200-650 K (aluminum oxide forms by 650 K). It is thought that CO and probably CH4 result from the decomposition of methoxy on the "Al site" with strong Ni character. C1 Temple Univ, Dept Chem, Philadelphia, PA 19122 USA. Brookhaven Natl Lab, Dept Chem, Upton, NY 11973 USA. RP Strongin, DR (reprint author), Temple Univ, Dept Chem, Philadelphia, PA 19122 USA. NR 50 TC 12 Z9 12 U1 0 U2 5 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 1089-5647 J9 J PHYS CHEM B JI J. Phys. Chem. B PD APR 16 PY 1998 VL 102 IS 16 BP 2970 EP 2978 DI 10.1021/jp980216b PG 9 WC Chemistry, Physical SC Chemistry GA ZJ968 UT WOS:000073271800020 ER PT J AU Aichmayr, G Toet, D Mulato, M Santos, PV Spangenberg, A Christiansen, S Albrecht, M Strunk, HP AF Aichmayr, G Toet, D Mulato, M Santos, PV Spangenberg, A Christiansen, S Albrecht, M Strunk, HP TI Lateral grain growth during the laser interference crystallization of a-Si SO PHYSICA STATUS SOLIDI A-APPLIED RESEARCH LA English DT Article; Proceedings Paper CT 185 International WE-Heraeus-Workshop on Laser Crystallization and Modification of Semiconductors (LCMS 98) CY JAN 26-28, 1998 CL TUTZING, GERMANY ID SILICON THIN-FILMS; AMORPHOUS-SILICON; SOLIDIFICATION AB We used laser interference crystallization (LIC), a combination of pulsed laser crystallization and holography, to fabricate polycrystalline silicon lines in an amorphous silicon (a-Si) film. Under appropriate conditions, the grains in the lines reach in-plane dimensions appreciably larger than the thickness of the initial a-Si film (up to 1.7 mu m for a 300 nm a-Si film). Atomic force and transmission electron microscopy indicate that these large grains result from the lateral solidification of the silicon lines melted by the laser pulse. The lateral growth is well reproduced by simulations of the LIC dynamics by means of a two-dimensional melting and solidification model. C1 Max Planck Inst Festkorperforsch, D-70569 Stuttgart, Germany. Univ Autonoma Madrid, Dept Fis Mat, E-28049 Madrid, Spain. Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. Univ Estadual Campinas, Inst Fis Gleb Wataghin, BR-13083970 Campinas, SP, Brazil. RP Santos, PV (reprint author), Max Planck Inst Festkorperforsch, Heisenbergstr 1, D-70569 Stuttgart, Germany. RI Mulato, Marcelo/J-7756-2012; Inst. of Physics, Gleb Wataghin/A-9780-2017 NR 12 TC 25 Z9 25 U1 0 U2 5 PU WILEY-V C H VERLAG GMBH PI BERLIN PA MUHLENSTRASSE 33-34, D-13187 BERLIN, GERMANY SN 0031-8965 J9 PHYS STATUS SOLIDI A JI Phys. Status Solidi A-Appl. Res. PD APR 16 PY 1998 VL 166 IS 2 BP 659 EP 666 DI 10.1002/(SICI)1521-396X(199804)166:2<659::AID-PSSA659>3.3.CO;2-L PG 8 WC Materials Science, Multidisciplinary; Physics, Applied; Physics, Condensed Matter SC Materials Science; Physics GA ZL810 UT WOS:000073473800014 ER PT J AU Ginocchio, JN Leviatan, A AF Ginocchio, JN Leviatan, A TI On the relativistic foundations of pseudospin symmetry in nuclei SO PHYSICS LETTERS B LA English DT Article DE relativistic mean field theory; symmetry; Dirac Hamiltonian; pseudospin ID PHYSICS; STATES; MODEL AB We show that the generators of pseudospin symmetry are the non-relativistic limit of the generators of an SU(2) symmetry which leaves invariant the Dirac Hamiltonian with scalar and vector potentials equal in magnitude but opposite in sign, V-V = -V-S. Furthermore, within this framework, we demonstrate that this symmetry may be approximately conserved for realistic scalar and vector potentials. (C) 1998 Published by Elsevier Science B.V. All rights reserved. C1 Univ Calif Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. Hebrew Univ Jerusalem, Racah Inst Phys, IL-91904 Jerusalem, Israel. RP Ginocchio, JN (reprint author), Univ Calif Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. NR 22 TC 152 Z9 155 U1 1 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 APR 16 PY 1998 VL 425 IS 1-2 BP 1 EP 5 DI 10.1016/S0370-2693(98)00188-9 PG 5 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA ZT720 UT WOS:000074117900001 ER PT J AU Douglas, MR Ooguri, H AF Douglas, MR Ooguri, H TI Why matrix theory is hard SO PHYSICS LETTERS B LA English DT Article ID FIELD-THEORY; QUANTIZATION AB Recently Sen and Seiberg gave a prescription for constructing the matrix theory in any superstring background. We use their prescription to test the finite N matrix theory conjecture on an ALE space. Based on our earlier work with Shenker, we find a sharper discrepancy between matrix theory computation and supergravity prediction. We discuss subtleties in the light-front quantization which may lead to a resolution to the discrepancy. (C) 1998 Published by Elsevier Science B.V. All rights reserved. C1 Inst Hautes Etud Sci, F-91440 Bures Sur Yvette, France. Rutgers State Univ, Dept Phys & Astron, Piscataway, NJ 08855 USA. Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Phys, Theory Grp, Berkeley, CA 94720 USA. RP Douglas, MR (reprint author), Inst Hautes Etud Sci, 35 Route Chartres, F-91440 Bures Sur Yvette, France. RI Ooguri, Hirosi/A-4407-2011; OI Ooguri, Hirosi/0000-0001-6021-3778 NR 28 TC 29 Z9 29 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0370-2693 J9 PHYS LETT B JI Phys. Lett. B PD APR 16 PY 1998 VL 425 IS 1-2 BP 71 EP 76 DI 10.1016/S0370-2693(98)00114-2 PG 6 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA ZT720 UT WOS:000074117900011 ER PT J AU Dine, M Rajaraman, A AF Dine, M Rajaraman, A TI Multigraviton scattering in the matrix model SO PHYSICS LETTERS B LA English DT Article AB We consider scattering processes in the matrix model with three incoming and three outgoing gravitons. We find a discrepancy between the amplitude calculated from the matrix model and the supergravity prediction. Possible sources for this discrepancy are discussed. (C) 1998 Elsevier Science B.V. All rights reserved. C1 Univ Calif Santa Cruz, Santa Cruz Inst Particle Phys, Santa Cruz, CA 95064 USA. Stanford Univ, Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. RP Dine, M (reprint author), Univ Calif Santa Cruz, Santa Cruz Inst Particle Phys, Santa Cruz, CA 95064 USA. EM dine@scipp.ucsc.edu; arvindra@leland.stanford.edu NR 27 TC 22 Z9 22 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0370-2693 J9 PHYS LETT B JI Phys. Lett. B PD APR 16 PY 1998 VL 425 IS 1-2 BP 77 EP 85 DI 10.1016/S0370-2693(98)00153-1 PG 9 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA ZT720 UT WOS:000074117900012 ER PT J AU Barbieri, R Hall, L Stocchie, A Weiner, N AF Barbieri, R Hall, L Stocchie, A Weiner, N TI Alternative theories of CP violation SO PHYSICS LETTERS B LA English DT Article AB Recent improvements to the limit of Delta M-Bs imply that pure superweak theories, while not excluded, no longer provide a good fit to the data. A class of general superweak theories is introduced in which all flavor changing interactions are governed by an approximate flavor symmetry which gives a "3 mechanism". These theories are in good agreement with data, and predict low values for \V-td\ \V-ub\V-cb\, B(K+-->pi(+)(v) over bar v), epsilon'\epsilon and CP asymmetries in B decays, and high values for Delta M-Bs and f(B) root B-B. An important example of such a theory is provided by weak scale supersymmetric theories with soft CP violation. The CP violation originates in the squark mass matrix, and, with phases of order unity, flavor symmetries can yield a correct prediction for the order of magnitude of epsilon(K). (C) 1998 Elsevier Science B.V. All rights reserved. C1 Scuola Normale Super Pisa, Pisa, Italy. Ist Nazl Fis Nucl, Sez Pisa, Pisa, Italy. Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. CNRS, IN2P3, Lab Accelerateur Lineaire, F-91405 Orsay, France. Univ Paris Sud, F-91405 Orsay, France. RP Barbieri, R (reprint author), Scuola Normale Super Pisa, Pisa, Italy. NR 17 TC 17 Z9 17 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0370-2693 J9 PHYS LETT B JI Phys. Lett. B PD APR 16 PY 1998 VL 425 IS 1-2 BP 119 EP 125 DI 10.1016/S0370-2693(98)00148-8 PG 7 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA ZT720 UT WOS:000074117900018 ER PT J AU Bozell, JJ Hoberg, JO Dimmel, DR AF Bozell, JJ Hoberg, JO Dimmel, DR TI Catalytic oxidation of para-substituted phenols with nitrogen dioxide and oxygen. SO TETRAHEDRON LETTERS LA English DT Article ID HYDROQUINONE ETHERS; NITRATION; BENZOQUINONES; DEALKYLATION; QUINONES; LIGNIN AB A series of para-substituted phenols was oxidized to the corresponding benzoquinones in moderate to high yield with catalytic amounts of NO2 under O-2 in MeOH, Little or no oxidation is observed under argon. Substrates of lower reactivity gave quinones when treated with stoichiometric amounts of NO2 in CCl4, but nitration of the aromatic ring became a significant side product. (C) 1998 Elsevier Science Ltd. All rights reserved. C1 Natl Renewable Energy Lab, Golden, CO 80401 USA. RP Bozell, JJ (reprint author), Natl Renewable Energy Lab, 1617 Cole Blvd, Golden, CO 80401 USA. NR 16 TC 24 Z9 24 U1 1 U2 11 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0040-4039 J9 TETRAHEDRON LETT JI Tetrahedron Lett. PD APR 16 PY 1998 VL 39 IS 16 BP 2261 EP 2264 DI 10.1016/S0040-4039(98)00242-1 PG 4 WC Chemistry, Organic SC Chemistry GA ZE729 UT WOS:000072824900011 ER PT J AU Wu, YS Pruess, K AF Wu, YS Pruess, K TI A numerical method for simulating non-Newtonian fluid flow and displacement in porous media SO ADVANCES IN WATER RESOURCES LA English DT Article DE non-Newtonian fluid flow; reservoir simulation; power-law fluid; Bingham fluid; multi-phase flow AB Flow and displacement of non-Newtonian fluids in porous media occurs in many subsurface systems, related to underground natural resource recovery and storage projects, as well as environmental remediation schemes. A thorough understanding of non-Newtonian fluid flow through porous media is of fundamental importance in these engineering applications. Considerable progress has been made in our understanding of single-phase porous flow behavior of non-Newtonian fluids through many quantitative and experimental studies over the past few decades. However, very little research can be found in the literature regarding multi-phase non-Newtonian fluid flow or numerical modeling approaches for such analyses. For non-Newtonian fluid flow through porous media, the governing equations become nonlinear, even under single-phase Bow conditions, because effective viscosity for the non-Newtonian fluid is a highly nonlinear function of the shear rate, or the pore velocity. The solution for such problems can in general only be obtained by numerical methods. We have developed a three-dimensional, fully implicit, integral finite difference simulator for single-and multi-phase flow of non-Newtonian fluids in porous/fractured media. The methodology, architecture and numerical scheme of the model are based on a general multi-phase, multi-component fluid and heat flow simulator-TOUGH2. Several rheological models for power-law and Bingham non-Newtonian fluids have been incorporated into the model. In addition, the model predictions on single-and multi-phase flow of the power-law and Bingham fluids have been verified against the analytical solutions available for these problems, and in all the cases the numerical simulations are in good agreement with the analytical solutions. In this presentation, we will discuss the numerical scheme used in the treatment of non-Newtonian properties, and several benchmark problems for model verification. In an effort to demonstrate the three-dimensional modeling capability of the model, a three-dimensional, two-phase flow example is also presented to examine the model results using laboratory and simulation results existing for the three-dimensional problem with Newtonian fluid flow. (C) 1998 Elsevier Science Limited. All rights reserved. C1 Univ Calif Berkeley, Ernest Orlando Lawrence Berkeley Natl Lab, Div Earth Sci, Berkeley, CA 94720 USA. RP Wu, YS (reprint author), Univ Calif Berkeley, Ernest Orlando Lawrence Berkeley Natl Lab, Div Earth Sci, Berkeley, CA 94720 USA. RI Wu, Yu-Shu/A-5800-2011 NR 30 TC 23 Z9 27 U1 1 U2 9 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0309-1708 J9 ADV WATER RESOUR JI Adv. Water Resour. PD APR 15 PY 1998 VL 21 IS 5 BP 351 EP 362 DI 10.1016/S0309-1708(97)00004-3 PG 12 WC Water Resources SC Water Resources GA ZM185 UT WOS:000073513200003 ER PT J AU Van Berkel, GJ Quirke, JME Tigani, RA Dilley, AS Covey, TR AF Van Berkel, GJ Quirke, JME Tigani, RA Dilley, AS Covey, TR TI Derivatization for electrospray ionization mass spectrometry. 3. Electrochemically ionizable derivatives SO ANALYTICAL CHEMISTRY LA English DT Article ID PERFORMANCE LIQUID-CHROMATOGRAPHY; FAST-ATOM-BOMBARDMENT; ASSISTED LASER DESORPTION/IONIZATION; ACID 2-(DIETHYLAMINO)ETHYL ESTER; SENSITIVE FERROCENE REAGENTS; CHARGE-TRANSFER COMPLEXATION; AMINO-ACIDS; CHEMICAL DERIVATIZATION; FULLERENE ANIONS; PEPTIDES AB In this paper, the use of ferrocene-based "electrochemically ionizable" derivatives to enhance ES-MS analysis of simple alcohols, sterols, and phenols is discussed. These derivatives are designed to take advantage of the electrolysis process inherent to operation of the ES ion source for selective ionization. Derivatization procedures, electrochemical character of the derivatives, and the ES-MS operational parameters necessary to maximize electrochemical ionization and to enhance gas-phase detection are presented with reference to ferrocenecarbamate ester derivatives of a variety of alcohol standards, as well as the ferroceneboronate derivative of the diol, pinacol. Tandem mass spectrometric analysis of the derivatives (precursor and product ion spectra) is shown to provide derivative confirmation, enhanced detection, and additional analyte structure information. The utility of this derivatization approach for the selective detection of alcohols in complicated mixtures is demonstrated using a saw palmetto (Serenoa repens) fruit extract known to contain a variety of alcohols at low levels. C1 Oak Ridge Natl Lab, Div Chem & Analyt Sci, Oak Ridge, TN 37831 USA. Florida Int Univ, Dept Chem, Miami, FL 33199 USA. SCIEX MDS Hlth Grp, Concord, ON L4K 4V8, Canada. RP Van Berkel, GJ (reprint author), Oak Ridge Natl Lab, Div Chem & Analyt Sci, Oak Ridge, TN 37831 USA. EM vanberkelgj@ornl.gov FU NCI NIH HHS [Y1-CB-0016-01] NR 66 TC 137 Z9 138 U1 4 U2 31 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0003-2700 J9 ANAL CHEM JI Anal. Chem. PD APR 15 PY 1998 VL 70 IS 8 BP 1544 EP 1554 DI 10.1021/ac971348o PG 11 WC Chemistry, Analytical SC Chemistry GA ZH511 UT WOS:000073118400012 PM 9569764 ER PT J AU Bocher, M Kusubov, N Nordahl, TE AF Bocher, M Kusubov, N Nordahl, TE TI Seasonal variations in right-to-left metabolic balance in the prefrontal cortex SO BIOLOGICAL PSYCHIATRY LA English DT Meeting Abstract C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Ctr Funct Imaging, Berkeley, CA 94720 USA. Univ Calif Davis, Med Ctr, Dept Psychiat, Sacramento, CA 95817 USA. 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 USA SN 0006-3223 J9 BIOL PSYCHIAT JI Biol. Psychiatry PD APR 15 PY 1998 VL 43 SU 8 MA 38 BP 12S EP 12S DI 10.1016/S0006-3223(98)90486-3 PG 1 WC Neurosciences; Psychiatry SC Neurosciences & Neurology; Psychiatry GA ZJ674 UT WOS:000073240700040 ER PT J AU Salo, R Robertson, LC Henik, A Nordahl, TE AF Salo, R Robertson, LC Henik, A Nordahl, TE TI Analysis of Stroop interference in patients with schizophrenia SO BIOLOGICAL PSYCHIATRY LA English DT Meeting Abstract C1 Univ Calif Davis, Med Ctr, Dept Psychiat, Davis, CA USA. Univ Calif Davis, Ctr Neurosci, Davis, CA USA. Ben Gurion Univ Negev, Zlotowski Ctr Neurosci, Dept Vet Affairs, IL-84105 Beer Sheva, Israel. Ben Gurion Univ Negev, Zlotowski Ctr Neurosci, Dept Behav Sci, IL-84105 Beer Sheva, Israel. Lawrence Berkeley Lab, Berkeley, CA USA. RI HENIK, AVISHAI/F-1176-2012 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 USA SN 0006-3223 J9 BIOL PSYCHIAT JI Biol. Psychiatry PD APR 15 PY 1998 VL 43 SU 8 MA 386 BP 116S EP 116S PG 1 WC Neurosciences; Psychiatry SC Neurosciences & Neurology; Psychiatry GA ZJ674 UT WOS:000073240700388 ER PT J AU Salo, R Robertson, LC Henik, A Nordahl, TE AF Salo, R Robertson, LC Henik, A Nordahl, TE TI Time course of inhibition and facilitation in patients with schizophrenia SO BIOLOGICAL PSYCHIATRY LA English DT Meeting Abstract C1 Univ Calif Davis, Med Ctr, Dept Psychiat, Davis, CA USA. Univ Calif Davis, Ctr Neurosci, Davis, CA USA. Ben Gurion Univ Negev, Zlotowski Ctr Neurosci, Dept Vet Affairs, IL-84105 Beer Sheva, Israel. Ben Gurion Univ Negev, Zlotowski Ctr Neurosci, Dept Behav Sci, IL-84105 Beer Sheva, Israel. Lawrence Berkeley Lab, Berkeley, CA USA. RI HENIK, AVISHAI/F-1176-2012 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 USA SN 0006-3223 J9 BIOL PSYCHIAT JI Biol. Psychiatry PD APR 15 PY 1998 VL 43 SU 8 MA 385 BP 116S EP 116S PG 1 WC Neurosciences; Psychiatry SC Neurosciences & Neurology; Psychiatry GA ZJ674 UT WOS:000073240700387 ER PT J AU Mian, IS AF Mian, IS TI Sequence, structural, functional, and phylogenetic analyses of three glycosidase families SO BLOOD CELLS MOLECULES AND DISEASES LA English DT Article DE hidden Markov model; Klotho; aging; Gaucher disease; Krabbe disease; protein evolution; TIM barrel; glycosidase ID HIDDEN MARKOV-MODELS; EXTRACELLULAR BETA-GLUCOSIDASE; PROTEIN SECONDARY STRUCTURE; GLYCOSYL HYDROLASES; CANDIDA-WICKERHAMII; KINETIN DELAYS; PLANT-GROWTH; SUPERFAMILY; INFORMATION; PREDICTION AB Glycosidases, which cleave the glycosidic bond between a carbohydrate and another moiety, have been classified into over 63 families. Here, a variety of computational techniques have been employed to examine three families important in normal and abnormal pathology with the aim of developing a framework for future homology modeling, experimental and other studies. Family 1 includes bacterial and archaeal enzymes as well as lactase phlorizin-hydrolase and klotho, glycosidases implicated in disaccharide intolerance II and aging respectively. A statistical model, a hidden Markov model (HMM), for the family I glycosidase domain was trained and used as the basis for comparative examination of the conserved and variable sequence and structural features as well as the phylogenetic relationships between family members. Although the structures of four family I glycosidases have been determined, this is the first comparative examination of all these enzymes. Aspects that are unique to specific members or subfamilies (substrate binding loops) as well those common to all members (a (beta/alpha)(8) barrel fold) have been defined, Active site residues in some domains in klotho and lactase-phlorizin hydrolases differ from other members and in one instance may bind but not cleave substrate. The four invariant and most highly conserved residues are not residues implicated in catalysis and/or substrate binding. Of these, a histidine may be involved in transition state stabilization. Glucosylceramidase (family 30) and galactosylceramidase (family 59) are mutated in the lysosomal storage disorders Gaucher disease and Krabbe disease, respectively HMM-based analysis, structure prediction studies and examination of disease mutations reveal a glycosidase domain common to these two families that also occurs in some bacterial glycosidases. Similarities in the reactions catalyzed by families 30 and 59 are reflected in the presence of a structurally and functionally related (beta/alpha)(8) barrel fold related to that in family 1. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Div Life Sci, Berkeley, CA 94720 USA. RP Mian, IS (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Div Life Sci, Mail Stop 29-100,1 Cyclotron Rd, Berkeley, CA 94720 USA. NR 69 TC 40 Z9 41 U1 1 U2 7 PU BLOOD CELLS FOUNDATION PI LA JOLLA PA C/O ERNEST BEUTLER SCRIPPS RES INST, DEPT MOLECULAR EXP MEDICINE, LA JOLLA, CA 92037 USA SN 1079-9796 J9 BLOOD CELL MOL DIS JI Blood Cells Mol. Dis. PD APR 15 PY 1998 VL 24 IS 6-7 BP 83 EP 100 DI 10.1006/bcmd.1998.9998 PG 18 WC Hematology SC Hematology GA ZH387 UT WOS:000073103400001 PM 9779294 ER PT J AU Staudigel, H Albarede, F Blichert-Toft, J Edmond, J McDonough, B Jacobsen, SB Keeling, R Langmuir, CH Nielsen, RL Plank, T Rudnick, R Shaw, HF Shirey, S Veizer, J White, W AF Staudigel, H Albarede, F Blichert-Toft, J Edmond, J McDonough, B Jacobsen, SB Keeling, R Langmuir, CH Nielsen, RL Plank, T Rudnick, R Shaw, HF Shirey, S Veizer, J White, W TI Geochemical Earth Reference Model (GERM): description of the initiative SO CHEMICAL GEOLOGY LA English DT Editorial Material DE transfer dynamics; fluxes; geochemical reservoirs; residence time; geochemical cycles; differentiation of the Earth ID CONTINENTAL-CRUST; OCEANIC BASALTS AB The Geochemical Earth Reference Model (GERM) initiative is a grass root effort with the goals of establishing a community consensus on a chemical characterization of the Earth, its major reservoirs, and the flu?;es between them. The GERM initiative will provide a review of available scientific constraints for: (1) the composition of all major chemical reservoirs of the present-day Earth, from core to atmosphere; (2) present-day fluxes between reservoirs; (3) the Earth's chemical and isotopic evolution since accretion; and (4) the chemical and isotopic evolution of seawater as a record of global tectonics and climate, Even though most of the constraints for the GERM will be drawn from chemical data sets, some data will have to come from other disciplines, such as geophysics, nuclear physics, and cosmochemistry. GERM also includes a diverse chemical and physical data base and computer codes that are useful for our understanding of how the Earth works as a dynamic chemical and physical system. The GERM initiative is developed in an open community discussion on the World Wide Web (http://www-ep.es.llnl.gov/germ/germ-home.html) that is moderated by editors with responsibilities for different reservoirs, fluxes, data bases, and other scientific or technical aspects. These editors have agreed to lay out an initial, strawman GERM for their respective sections and to moderate community discussions leading to a first, preliminary consensus. The development of the GERM began with an initial workshop in Lyon, France in March, 1996. Since then, the GERM has continued to be developed on the Internet, punctuated by workshops and special sessions at professional meetings. A second GERM workshop will be held in La Jolla, CA USA on March 10-13, 1998. (C) 1998 Elsevier Science B.V. All nights reserved. C1 Ecole Normale Super Lyon, F-693647 Lyon 7, France. Univ Calif San Diego, Cecil & Ida Green Inst Geophys & Planetary Phys, Scripps Inst Oceanog, La Jolla, CA 92117 USA. MIT, Dept Earth Atmospher & Planetary Sci, Cambridge, MA 02139 USA. Harvard Univ, Dept Earth & Planetary Sci, Cambridge, MA 02138 USA. Univ Calif San Diego, Scripps Inst Oceanog, Div Marine Res, La Jolla, CA 92117 USA. Lamont Doherty Earth Observ, Palisades, NY 10964 USA. Oregon State Univ, Coll Oceanog, Corvallis, OR 97331 USA. Univ Kansas, Dept Geol, Lawrence, KS 66045 USA. Univ Calif Lawrence Livermore Natl Lab, Geosci & Environm Technol Div, Livermore, CA 94550 USA. Carnegie Inst Washington, Dept Terr Magnetism, Washington, DC 20015 USA. Univ Ottawa, Dept Geol, Ottawa, ON K1N 6N5, Canada. Cornell Univ, Dept Geol, Ithaca, NY 14853 USA. RP Albarede, F (reprint author), Ecole Normale Super Lyon, 46 Allee Italie, F-693647 Lyon 7, France. RI Shaw, Henry/B-6445-2012; Plank, Terry/D-9542-2012; Blichert-Toft, Janne/C-8280-2012; Jacobsen, Stein/B-1759-2013; White, William/N-3231-2014; Albarede, Francis/A-8871-2011 OI Shaw, Henry/0000-0003-0681-5430; Blichert-Toft, Janne/0000-0002-4932-4079; White, William/0000-0001-9024-7039; Rudnick, Roberta/0000-0003-1559-7463; Albarede, Francis/0000-0003-1994-1428 NR 18 TC 13 Z9 21 U1 1 U2 9 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0009-2541 J9 CHEM GEOL JI Chem. Geol. PD APR 15 PY 1998 VL 145 IS 3-4 BP 153 EP 159 DI 10.1016/S0009-2541(97)00141-1 PG 7 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA ZV404 UT WOS:000074301200001 ER PT J AU Kerrick, DM Caldeira, K AF Kerrick, DM Caldeira, K TI Metamorphic CO2 degassing from orogenic belts SO CHEMICAL GEOLOGY LA English DT Article; Proceedings Paper CT Workshop on Geochemical Earth Reference Model CY MAR, 1996 CL LYON, FRANCE DE carbon dioxide; Cenozoic; degassing; metamorphism; orogenic belts ID CONTINENT-CONTINENT COLLISION; SOUTHERN OMINECA BELT; WAITS RIVER FORMATION; REGIONAL METAMORPHISM; BRITISH-COLUMBIA; CARBON-DIOXIDE; NEW-ZEALAND; EXTENSIONAL TECTONICS; PHANEROZOIC TIME; ATMOSPHERIC CO2 AB Kerrick and Caldeira (1993, 1994a) concluded that metamorphic CO2 degassing in collisional orogens, and especially the Himalayan orogenic belt, could have been an important factor in enhancing paleoatmospheric CO2 levels and contributing to early Cenozoic global greenhouse warming [Kerrick, D.M., Caldeira, K., 1993. Paleoatmospheric consequences of CO2 released during early Cenozoic regional metamorphism in the Tethyan orogen. In: Touret, J.L.R., Thompson, A.B. (Guest-Eds.), Fluid-Rock Intel.action in the Deeper Continental Lithosphere. Chem. Geol. 108, 201-230.] [Kerrick, D.M., Caldeira, K., 1994a. Metamorphic CO2 degassing and early Cenozoic paleoclimate. GSA (Geol. Sec. Am.) Today 4, 57-65.]. However, our revised CO2 mass loss computations for regional metamorphism in the Himalaya-Karakoram belt incorporating recent geochronologic data and revised estimates of the proportion of carbonate source rocks indicate that metamorphic CO2 degassing from this orogen cannot explain Early Eocene warmth. Widespread pluton-induced hydrothermal flow occurred during the Eocene in the Cordilleran belt of western North America. Synmetamorphic intrusions, which are common in metamorphic belts, may cause significant regional fluid flow. To obtain a representative CO2 flux from such environments, we computed a CO2 flux of 1.5 x 10(12) mol km(-2) Ma(-1) from petrologic and geochemical studies of the Paleozoic plutonic-metamorphic belt in New England (northeastern United States). For the 2 X 10(6) km(2) area of Eocene metamorphism in the North American Cordillera, the CO2 fluxes derived from the New England metamorphic belt yield an area-integrated flux of similar to 3 x 10(18) mol Ma(-1). If a significant fi action of this CO2 entered the atmosphere, this degassing flux would alone account for Eocene greenhouse global warming. For the Ominica belt within the Cordilleran orogen, a volumetric estimate of the mass of carbonate veins indicates that the consumption of CO2 by precipitation of carbonate veins may not significantly decrease the amount of CO2 in fluids that convect to near-surface crustal levels. Compared to other Eocene metamorphic belts, the widespread hydrothermal activity in the North American Cordillera may have been the largest, and most climatically significant, source of metamorphic CO2 to the Eocene atmosphere. CO2 degassing by active metamorphism is most significant in extensional regimes of high heat flow. Extensional tectonism and hydrothermal activity in metamorphic belts may have substantially contributed to atmospheric CO2 content throughout the Phanerozoic. Examples include the Mesozoic circum-Pacific metamorphic belt, and Oligocene-Miocene regional metamorphism in the Himalayan orogen. (C) 1998 Elsevier Science B.V. All rights reserved. C1 Penn State Univ, Dept Geosci, University Pk, PA 16802 USA. Univ Calif Lawrence Livermore Natl Lab, Climate Syst Modeling Grp, Livermore, CA 94550 USA. RP Kerrick, DM (reprint author), Penn State Univ, Dept Geosci, University Pk, PA 16802 USA. EM kerrick@geosc.psu.edu RI Caldeira, Ken/E-7914-2011 NR 99 TC 59 Z9 61 U1 1 U2 19 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0009-2541 J9 CHEM GEOL JI Chem. Geol. PD APR 15 PY 1998 VL 145 IS 3-4 BP 213 EP 232 DI 10.1016/S0009-2541(97)00144-7 PG 20 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA ZV404 UT WOS:000074301200004 ER PT J AU Banaszak, JE Reed, DT Rittmann, BE AF Banaszak, JE Reed, DT Rittmann, BE TI Speciation-dependent toxicity of neptunium(V) toward Chelatobacter heintzii SO ENVIRONMENTAL SCIENCE & TECHNOLOGY LA English DT Article ID CARBONATE COMPLEXES; NITRILOTRIACETATE; URANIUM AB This work investigates how chemical speciation controls the toxicity of neptunium and the neptunium-NTA complex toward Chelatobacter heintzii. We studied the effect of aquo and complexed/precipitated neptunium on the growth of C. heintzii in noncomplexing glucose and phosphate-buffered nitrilotriacetic acid (NTA) growth media. Equilibrium chemical speciation modeling and absorption spectroscopy were used to link neptunium speciation to biological growth inhibition. Our results show that metal toxicity of aquo NpO2+ significantly limits the growth of C. heintzii at free metal ion concentrations greater than approximate to 10(-5) M. However, neptunium concentrations greater than or equal to 10(-4) M do not cause measurable radiotoxicity effects in C. heintzii when present in the form of a neptunium-NTA complex or colloidal/precipitated neptunium phosphate. The neptunium-NTA complex, which is stable under aerobic conditions, is destabilized by microbial degradation of NTA. When phosphate was present, degradation of NTA led to the precipitation of a neptunium-phosphate phase. C1 Northwestern Univ, Dept Civil Engn, Evanston, IL 60208 USA. Argonne Natl Lab, Div Chem Technol, Argonne, IL 60439 USA. RP Reed, DT (reprint author), Northwestern Univ, Dept Civil Engn, 2145 Sheridan Rd, Evanston, IL 60208 USA. NR 37 TC 16 Z9 16 U1 1 U2 3 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0013-936X J9 ENVIRON SCI TECHNOL JI Environ. Sci. Technol. PD APR 15 PY 1998 VL 32 IS 8 BP 1085 EP 1091 DI 10.1021/es970664h PG 7 WC Engineering, Environmental; Environmental Sciences SC Engineering; Environmental Sciences & Ecology GA ZH500 UT WOS:000073117300011 ER PT J AU Tokunaga, TK Sutton, SR Bajt, S Nuessle, P Shea-McCarthy, G AF Tokunaga, TK Sutton, SR Bajt, S Nuessle, P Shea-McCarthy, G TI Selenium diffusion and reduction at the water-sediment boundary: Micro-XANES spectroscopy of reactive transport SO ENVIRONMENTAL SCIENCE & TECHNOLOGY LA English DT Article ID X-RAY-ABSORPTION; NEAR-EDGE STRUCTURE; FLUORESCENCE MICROPROBE; KESTERSON RESERVOIR; SELENATE REDUCTION; GROUNDWATER CONTAMINATION; MODEL COMPOUNDS; SPECIATION; SOILS; TRANSFORMATIONS AB Mechanistic understanding of trace element cycling between surface waters and sediments can require highly spatially resolved information at water-sediment boundaries not obtainable by conventional sampling and analytical methods. This study demonstrates the application of micro-X-ray absorption near-edge structure (micro-XANES) spectroscopy for obtaining such direct, in-situ, spatially and temporally resolved information for selenium. The experiments determine the fate of soluble Se(VI) ponded over water-saturated oxidizing versus reducing sediments. Scanning micro-XANES analyses showed Se(VI) removal from ponded waters by diffusion into sediments and by conversion to Se(0) in the reducing sediment. Zones of accumulation of insoluble Se(0) were heterogeneously distributed. These results show that the scale over which volume averaging of chemical species is performed at sediment-water boundaries must be selected carefully and that the spatial resolution offered by micro-XANES is well-suited for these types of investigations. C1 Univ Chicago, Dept Geophys Sci, Chicago, IL 60637 USA. Univ Chicago, Consortium Adv Radiat Sources, Chicago, IL 60637 USA. Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. Univ Georgia, Savannah River Ecol Lab, Adv Analyt Ctr Environm Sci, Aiken, SC 29802 USA. Brookhaven Natl Lab, Upton, NY 11973 USA. EO Lawrence Berkeley Natl Lab, Div Earth Sci, Berkeley, CA 94720 USA. RP Tokunaga, TK (reprint author), EO Lawrence Berkeley Natl Lab, Div Earth Sci, 1 Cyclotron Rd,90-1116, Berkeley, CA 94720 USA. EM tktokunaga@lbl.gov RI Bajt, Sasa/G-2228-2010; Schneider, Larissa/C-9863-2012; Tokunaga, Tetsu/H-2790-2014 OI Tokunaga, Tetsu/0000-0003-0861-6128 NR 48 TC 37 Z9 38 U1 1 U2 14 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0013-936X J9 ENVIRON SCI TECHNOL JI Environ. Sci. Technol. PD APR 15 PY 1998 VL 32 IS 8 BP 1092 EP 1098 DI 10.1021/es9706559 PG 7 WC Engineering, Environmental; Environmental Sciences SC Engineering; Environmental Sciences & Ecology GA ZH500 UT WOS:000073117300012 ER PT J AU Lam, NP Neumann, AU Perelson, AS Gretch, DR Wileys, TE Layden, TJ AF Lam, NP Neumann, AU Perelson, AS Gretch, DR Wileys, TE Layden, TJ TI Difference in viral kinetics between HCV genotype 1 versus 2 or 3 may explain differences in treatment response SO GASTROENTEROLOGY LA English DT Meeting Abstract C1 Univ Illinois, Dept Pharm Practice, Chicago, IL 60680 USA. Univ Illinois, Dept Med, Chicago, IL 60680 USA. Bar Ilan Univ, IL-52100 Ramat Gan, Israel. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Univ Washington, Seattle, WA 98195 USA. NR 0 TC 2 Z9 3 U1 0 U2 0 PU W B SAUNDERS CO PI PHILADELPHIA PA INDEPENDENCE SQUARE WEST CURTIS CENTER, STE 300, PHILADELPHIA, PA 19106-3399 USA SN 0016-5085 J9 GASTROENTEROLOGY JI Gastroenterology PD APR 15 PY 1998 VL 114 IS 4 SU S MA L0347 BP A1282 EP A1282 PN 2 PG 1 WC Gastroenterology & Hepatology SC Gastroenterology & Hepatology GA ZH263 UT WOS:000073089605205 ER PT J AU Lam, NP Neumann, AU Perelson, AS Gretch, DR Wileys, TE Layden, TJ AF Lam, NP Neumann, AU Perelson, AS Gretch, DR Wileys, TE Layden, TJ TI Biphasic viral clearance of HCV geneotype 1 (GENO 1) during high dose IFN induction treatment SO GASTROENTEROLOGY LA English DT Meeting Abstract C1 Univ Illinois, Dept Pharm Practice, Chicago, IL 60680 USA. Univ Illinois, Dept Med, Chicago, IL 60680 USA. Bar Ilan Univ, IL-52100 Ramat Gan, Israel. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Univ Washington, Seattle, WA 98195 USA. NR 0 TC 2 Z9 3 U1 0 U2 0 PU W B SAUNDERS CO PI PHILADELPHIA PA INDEPENDENCE SQUARE WEST CURTIS CENTER, STE 300, PHILADELPHIA, PA 19106-3399 USA SN 0016-5085 J9 GASTROENTEROLOGY JI Gastroenterology PD APR 15 PY 1998 VL 114 IS 4 SU S MA L0346 BP A1282 EP A1282 PN 2 PG 1 WC Gastroenterology & Hepatology SC Gastroenterology & Hepatology GA ZH263 UT WOS:000073089605204 ER PT J AU Xu, YZ Soloway, RD Ferraro, JR Xei, DT Xu, JP Xu, DF Wu, JG Xu, GX AF Xu, YZ Soloway, RD Ferraro, JR Xei, DT Xu, JP Xu, DF Wu, JG Xu, GX TI The structural basis for the differences in infrared spectra for anhydrous cholesterol obtained using the KBR pellet and the fluorolube mull methods. SO GASTROENTEROLOGY LA English DT Meeting Abstract C1 Peking Univ, Dept Chem, Beijing 100871, Peoples R China. Univ Texas, Med Branch, Div Gastroenterol, Galveston, TX 77550 USA. Argonne Natl Lab, Div Chem, Argonne, IL 60439 USA. NR 0 TC 0 Z9 0 U1 1 U2 2 PU W B SAUNDERS CO PI PHILADELPHIA PA INDEPENDENCE SQUARE WEST CURTIS CENTER, STE 300, PHILADELPHIA, PA 19106-3399 USA SN 0016-5085 J9 GASTROENTEROLOGY JI Gastroenterology PD APR 15 PY 1998 VL 114 IS 4 SU S MA G2250 BP A550 EP A550 DI 10.1016/S0016-5085(98)82236-1 PN 2 PG 1 WC Gastroenterology & Hepatology SC Gastroenterology & Hepatology GA ZH263 UT WOS:000073089602236 ER PT J AU Parra, M Gascard, P Walensky, LD Snyder, SH Mohandas, N Conboy, JG AF Parra, M Gascard, P Walensky, LD Snyder, SH Mohandas, N Conboy, JG TI Cloning and characterization of 4.1G (EPB41L2), a new member of the skeletal protein 4.1 (EPB41) gene family SO GENOMICS LA English DT Article ID ERYTHROID BETA-SPECTRIN; ANKYRIN GENE; BRAIN SPECTRIN(240/235E); FUNCTIONAL DOMAINS; MAJOR ANKYRIN; ACTIN BINDING; MESSENGER-RNA; CELL-BODIES; ISOFORMS; IDENTIFICATION AB The prototypical erythrocyte membrane skeletal protein 4.1 (HGMW-approved symbol EPB41), here designated 4.1R, is encoded by a large, complexly spliced gene located on human chromosome 1p32-p33. In this paper we report evidence for a second 4.1 gene, 4.1G (HGMW-approved symbol EPB41L2), which maps to human chromosome 6q23 and is widely expressed among human tissues. The complete nucleotide sequence of 4.1G cDNA predicts a 113-kDa protein that exhibits three regions of high homology to 4.1R, including the membrane binding domain, the spectrin-actin binding domain, and the C-terminal domain. Interspersed among the shared domains are unique sequences that may define functional differences between 4.1R and 4.1G. Specific isoforms of 4.1R and 4.1G exhibit differential subcellular localizations. These results expand the 4.1 gene superfamily and demonstrate that the diverse cellular complement of 4.1 isoforms results from both alternative splicing and expression Of distinct genes. (C) 1998 Academic Press. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Div Life Sci, Berkeley, CA 94720 USA. Johns Hopkins Univ, Sch Med, Dept Neurosci, Baltimore, MD 21205 USA. RP Conboy, JG (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Div Life Sci, MS 74-174, Berkeley, CA 94720 USA. NR 42 TC 85 Z9 89 U1 0 U2 0 PU ACADEMIC PRESS INC PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0888-7543 J9 GENOMICS JI Genomics PD APR 15 PY 1998 VL 49 IS 2 BP 298 EP 306 DI 10.1006/geno.1998.5265 PG 9 WC Biotechnology & Applied Microbiology; Genetics & Heredity SC Biotechnology & Applied Microbiology; Genetics & Heredity GA ZN543 UT WOS:000073656400016 PM 9598318 ER PT J AU Cotton, FA Haefner, SC Sattelberger, AP AF Cotton, FA Haefner, SC Sattelberger, AP TI Metal-metal multiply-bonded complexes of technetium. 7. Oxidative decomposition of tetrachlorotetrakis(dimethylphenylphosphino)ditechnetium (II) by an aminium hexachloroantimonate(V) SO INORGANICA CHIMICA ACTA LA English DT Article DE crystal structures; technetium complexes; antimony-arene complexes; metal-metal multiply-bonded complexes ID STRUCTURAL CHARACTERIZATION; SANDWICH STRUCTURE; CRYSTAL-STRUCTURES; ARENE COMPLEXES; SBCL3; SBBR3; DITECHNETIUM; REACTIVITY; BICL3; BIBR3 AB TcCl4(PMe2Ph)(2) . 2SbCl(3) was isolated in low yield from the reaction of Tc2Cl4(PMe2Ph)(2) with 2 equiv. of [(p-BrC6H4)(3)N] [SbCl6] in acetonitrile. Single crystals were obtained by slow evaporation of a toluene solution. The: structure, determined by X-ray crystallography, is composed of infinite one-dimensional chains of an alternating sequence of TcCl4(PMe2Ph)(2) and (SbCl3)(2) molecules. The individual molecular species are loosely associated through Lewis acid-base interactions between the equatorial chlorine atoms of TcCl4(PMe2Ph)(2) and the individual SbCl3 units. The chains are continued by an additional weak Lewis acid-base interaction between neighboring SbCl3 molecules. The distorted pentagonal bipyramidal coordination geometry about the antimony atom is completed by a weak pi-interaction with the phenyl ring of TcCl4(PMe2Ph)(2). Crystal data for TcCl4(PNe2Ph)(2) . 2SbCl(3) (1) at 23 degrees C: M = 972.28, triclinic, (No. 2), a = 10.591(3), b = 10.619(2), c = 7.578(1) Angstrom, a = 104.54(2), beta = 99.69(2), gamma = 69.92(2)degrees, V = 771.7(3) Angstrom(3), Z = 1. (C) 1998 Elsevier Science S.A. C1 Texas A&M Univ, Dept Chem, Mol Struct & Bonding Lab, College Stn, TX 77843 USA. Univ Calif Los Alamos Natl Lab, Div Chem Sci & Technol, Los Alamos, NM 87545 USA. RP Cotton, FA (reprint author), Texas A&M Univ, Dept Chem, Mol Struct & Bonding Lab, College Stn, TX 77843 USA. NR 29 TC 5 Z9 5 U1 1 U2 2 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0020-1693 J9 INORG CHIM ACTA JI Inorg. Chim. Acta PD APR 15 PY 1998 VL 271 IS 1-2 BP 187 EP 190 DI 10.1016/S0020-1693(97)05957-4 PG 4 WC Chemistry, Inorganic & Nuclear SC Chemistry GA ZD617 UT WOS:000072704800028 ER PT J AU Sirac, S Planinic, P Maric, L Brnicevic, N McCarley, RE AF Sirac, S Planinic, P Maric, L Brnicevic, N McCarley, RE TI Synthesis and properties of [M6X12(C3H7NO)(6)]X-2 (M=Nb, Ta; X=Cl, Br) SO INORGANICA CHIMICA ACTA LA English DT Article DE cluster complexes; tantalum complexes; DMF complexes; niobium complexes ID X = CL; HEXANUCLEAR NIOBIUM; CRYSTAL-STRUCTURES; CLUSTER; TANTALUM; COMPLEXES; METAL; (2+); HYDROXIDES; HALIDES AB Reactions of the complexes [M6X12(C2H5OH)(6)]X-2 (M = Nb, Ta; X = Cl, Br) with N,N-dimethylformamide afforded a new series of clusters of the composition [M6X12(C3H7NO)(6)]X-2. These microcrystalline substances are not isotypic with any other series of niobium and tantalum clusters with the [M6X12](2+) unit. The analytical and spectral data point to the conclusion that all octahedral coordination sites in the hexanuclear cluster units are occupied by the oxygen bonded N,N-dimethylformamide molecules. (C) 1998 Elsevier Science S.A. C1 Rudjer Boskovic Inst, Zagreb 10000, Croatia. Univ Zagreb, Fac Sci, Zagreb 10000, Croatia. Ames Lab, Ames, IA USA. Iowa State Univ, Ames, IA 50011 USA. RP Brnicevic, N (reprint author), Rudjer Boskovic Inst, Pob 1016, Zagreb 10000, Croatia. NR 25 TC 4 Z9 4 U1 0 U2 0 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0020-1693 J9 INORG CHIM ACTA JI Inorg. Chim. Acta PD APR 15 PY 1998 VL 271 IS 1-2 BP 239 EP 242 DI 10.1016/S0020-1693(97)05956-2 PG 4 WC Chemistry, Inorganic & Nuclear SC Chemistry GA ZD617 UT WOS:000072704800040 ER PT J AU Bitteker, L AF Bitteker, L TI Nuclear-induced electrical conductivity in He-3 SO JOURNAL OF APPLIED PHYSICS LA English DT Article AB The results of a computational and experimental investigation of nuclear-induced electrical conductivity enhancement in He-3 is discussed with application to magnetohydrodynamic (MHD) energy conversion. Calculations based on the standard model of interactions and conductivity in a gas of partially ionized He-3 suggest a region of conditions not previously considered may provide significant conductivity enhancement. Specifically, at densities less than standard atmospheric density and neutron flux greater than 1x10(12)/cm(2) s, conductivity greater than 10 mho/m may be achievable. These calculations also suggest conductivities of several hundred mho/m may be possible for an achievable range of conditions. Additionally, the calculations show that nuclear-induced conductivity is strongly density dependent and weakly temperature dependent. Therefore, higher flow velocities, and hence higher power densities than those typical in traditional MHD channels utilizing thermal ionization would be possible. Experiments were designed to measure the conductivity enhancement in pure He-3 for temperatures from 300 to 1500 K, pressure from 3.8x10(3)-7.6x10(-2) Torr, and thermal neutron flux from 10(10) to 10(16)/cm(2)s. Due to unforeseeable events, the reactor facility was shut down prior to the completion of these experiments resulting in a sparse data set. The data collected indicate the actual conductivity enhancement is approximately three orders of magnitude below the value calculated by the standard model of interactions. Possible reasons for this discrepancy are discussed, and additional calculations and experiments an proposed to resolve the discrepancy. (C) 1998 American Institute of Physics. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Bitteker, L (reprint author), Univ Calif Los Alamos Natl Lab, Mail Stop E526, Los Alamos, NM 87545 USA. EM lbj@lanl.gov NR 12 TC 0 Z9 0 U1 0 U2 2 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD APR 15 PY 1998 VL 83 IS 8 BP 4018 EP 4023 DI 10.1063/1.367156 PG 6 WC Physics, Applied SC Physics GA ZJ989 UT WOS:000073273900010 ER PT J AU Fleddermann, CB Hebner, GA AF Fleddermann, CB Hebner, GA TI Measurements of relative BCl density in BCl3-containing inductively coupled radio frequency plasmas SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID REFERENCE CELL; DISCHARGES; DISSOCIATION AB The relative density of BCl radicals in inductively coupled plasmas has been studied using laser-induced fluorescence (LIF), and the BCl excited state has been studied using plasma-induced emission (PIE). Measurements were made as a function of input power, pressure, position, and as a function of gas ratio for industry-relevant metal-etch gas mixtures containing BCl3, Cl-2, Ar, and N-2. LIF was used to measure the ground state BCl population, whereas PIE monitored the BCl A (1) Pi excited state; the LIF and PIE intensities varied differently as the plasma parameters were changed. Between 150 and 400 W input power at 20 mTorr pressure, there was no variation in BCl density, indicating that the dissociation fraction for BCl3 to BCl was constant with power. No significant interactions between BCl3 and Cl-2 or Ar were evident in the LIF measurements. However, the BCl density was suppressed by addition of nitrogen to the plasma. The BCl density was radially uniform for all gas mixtures, but axial measurements showed a slight decrease in BCl density near the upper electrode. After running the reactor with a BCl3/N-2 mixture, BCl was observed for up to an hour after the discharge was switched to Cl-2: this is attributed to buildup of BN films on reactor surfaces and subsequent etching of the film by Cl. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. Univ New Mexico, Dept Elect & Comp Engn, Albuquerque, NM 87131 USA. RP Fleddermann, CB (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. NR 15 TC 9 Z9 9 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD APR 15 PY 1998 VL 83 IS 8 BP 4030 EP 4036 DI 10.1063/1.367158 PG 7 WC Physics, Applied SC Physics GA ZJ989 UT WOS:000073273900012 ER PT J AU Kubota, NA Economou, DJ Plimpton, SJ AF Kubota, NA Economou, DJ Plimpton, SJ TI Molecular dynamics simulations of low-energy (25-200 eV) argon ion interactions with silicon surfaces: Sputter yields and product formation pathways SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID PARTICLE BOMBARDMENT; SI(100)(2X1) SURFACE; COMPUTER-SIMULATION; CL2 ENVIRONMENT; FLUORINE; SI; CHLORINE; SEMICONDUCTORS; DEPENDENCE; CHEMISTRY AB The etch yield and subsurface damage are important issues in low energy (<200 eV) ion interactions with surfaces. In particular, atomic layer etching requires etching of electronic materials with monolayer precision and minimal interlayer atomic mixing. In this study, the molecular dynamics technique is used to simulate the impact of argon ions on chlorine-free and chlorine-passivated silicon surfaces, under conditions relevant to atomic layer etching. Thousands of individual ion impact simulations are performed on a massively parallel supercomputer. The silicon sputter yield is obtained for Ar ion energies ranging from 25 to 200 eV. Where possible, simulation results are compared to available experimental data. Volatile product formation during ion bombardment of ordered surfaces tends to follow distinct local trajectories. For example, the formation of products due to 120 eV Ar ions impacting onto Si(001)(2 x 1) at normal incidence has been found to occur mainly by a mechanism in which the Ar ion impacts directly in-between a surface silicon dimer pair. The energetic recoiled silicon atoms undercut nearby silicon atoms resulting in product formation. Several other product formation pathways have also been observed. (C) 1998 American Institute of Physics. C1 Univ Houston, Dept Chem Engn, Plasma Proc Lab, Houston, TX 77204 USA. Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Kubota, NA (reprint author), Univ Houston, Dept Chem Engn, Plasma Proc Lab, Houston, TX 77204 USA. EM economou@uh.edu NR 47 TC 48 Z9 48 U1 1 U2 9 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD APR 15 PY 1998 VL 83 IS 8 BP 4055 EP 4063 DI 10.1063/1.367225 PG 9 WC Physics, Applied SC Physics GA ZJ989 UT WOS:000073273900016 ER PT J AU Sewell, TD AF Sewell, TD TI Monte Carlo calculations of the hydrostatic compression of hexahydro-1,3,5-trinitro-1,3,5-triazine and beta-octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine SO JOURNAL OF APPLIED PHYSICS LA English DT Article AB Rigid molecule Monte Carlo simulations are used in a computational study of the isothermal, hydrostatic compression of crystalline hexahydro-1,3,5-trinitro-1,3,5-triazine and beta-octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine for pressures in the range 0 Gpa less than or equal to p less than or equal to 7.5 Gpa. The purpose of the investigation is to assess the utility of simple intermolecular potential-energy functions, generally parameterized for ambient conditions of temperature and pressure, for studies of polyatomic molecular crystals under the extremes of pressure that are important in accident scenarios involving high explosives. The calculated results are found to be in good agreement with published x-ray diffraction data. (C) 1998 American Institute of Physics. C1 Univ Calif Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. RP Sewell, TD (reprint author), Univ Calif Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. NR 15 TC 26 Z9 26 U1 0 U2 1 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD APR 15 PY 1998 VL 83 IS 8 BP 4142 EP 4145 DI 10.1063/1.367168 PG 4 WC Physics, Applied SC Physics GA ZJ989 UT WOS:000073273900028 ER PT J AU Bowers, RL Brownell, JH Lee, H McLenithan, KD Scannapieco, AJ Shanahan, WR AF Bowers, RL Brownell, JH Lee, H McLenithan, KD Scannapieco, AJ Shanahan, WR TI Design and modeling of precision solid liner experiments on Pegasus SO JOURNAL OF APPLIED PHYSICS LA English DT Article AB Pulsed power driven solid liners may be used for a variety of physics experiments involving materials at high stresses. These include shock formation and propagation, material strain-rate effects, material melt, instability growth, and ejecta from shocked surfaces. We describe the design and performance of a cylindrical solid liner that can attain velocities in the several mm/mu s regime, and that can be used to drive high-stress experiments. An approximate theoretical analysis of solid liner implosions is used to establish the basic parameters (mass, materials, and initial radius) of the driver. We then present one-dimensional and two-dimensional simulations of magnetically driven, Liner implosions which include resistive heating and elastic-plastic behavior. The two-dimensional models are used to study the effects of electrode glide planes on the liner's performance, to examine sources of perturbations of the liner, and to assess possible effects of instability growth during the implosion. Finally, simulations an compared with experimental data to show that the solid liner performed as predicted computationally. Experimental data indicate that the liner imploded from an initial radius of 2.4 cm to a target radius of 1.5 cm, and that it was concentric and cylindrical to better than the experimental resolution (60 mu m) at the target. The results demonstrate that a precision solid liner can be produced for high-stress, pulsed power applications experiments. (C) 1998 American Institute of Physics. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Bowers, RL (reprint author), Univ Calif Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. NR 20 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 USA SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD APR 15 PY 1998 VL 83 IS 8 BP 4146 EP 4159 DI 10.1063/1.367230 PG 14 WC Physics, Applied SC Physics GA ZJ989 UT WOS:000073273900029 ER PT J AU Maria, JP Trolier-McKinstry, S Schlom, DG Hawley, ME Brown, GW AF Maria, JP Trolier-McKinstry, S Schlom, DG Hawley, ME Brown, GW TI The influence of energetic bombardment on the structure and properties of epitaxial SrRuO3 thin films grown by pulsed laser deposition SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID TEMPERATURE; SURFACE; CARUO3 AB SrRuO3 epitaxial thin films were prepared by pulsed laser deposition (PLD) under a range of growth conditions to study the impact of bombardment on properties. Growth conditions favoring energetic bombardment resulted in SrRuO3 films with expanded in-plane and out-of-plane lattice constants. In particular, SrRuO3 films with pseudocubic out-of-plane lattice constants as large as 4.08 Angstrom were deposited (3.8% larger than the bulk value). Those films with expanded lattices had greater resistivities and depressed Curie transition temperatures. The relative lattice mismatch between film and substrate was found to temper the effect of bombardment such that as the mismatch increased, a higher degree of bombardment was required to produce extended lattice parameters. The pressure-dependent energetic species inherent to PLD and their interaction with the ambient are believed to be the source of the bombarding flux. Further experiments confirmed that in the range of 20-200 mTorr, oxygen/ozone partial pressure had a negligible effect on the film properties. (C) 1998 American Institute of Physics. C1 Penn State Univ, Dept Mat Sci & Engn, Intercoll Mat Res Lab, University Pk, PA 16802 USA. Univ Calif Los Alamos Natl Lab, Ctr Mat Sci, Los Alamos, NM 87545 USA. RP Maria, JP (reprint author), Penn State Univ, Dept Mat Sci & Engn, Intercoll Mat Res Lab, University Pk, PA 16802 USA. EM jpm133@psu.edu RI Schlom, Darrell/J-2412-2013; OI Schlom, Darrell/0000-0003-2493-6113; Trolier-McKinstry, Susan/0000-0002-7267-9281 NR 30 TC 52 Z9 53 U1 3 U2 33 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD APR 15 PY 1998 VL 83 IS 8 BP 4373 EP 4379 DI 10.1063/1.367195 PG 7 WC Physics, Applied SC Physics GA ZJ989 UT WOS:000073273900058 ER PT J AU Mao, SS Mao, XL Yoo, JH Greif, R Russo, RE AF Mao, SS Mao, XL Yoo, JH Greif, R Russo, RE TI Thermionic electron emission from narrow band-gap semiconductors under picosecond laser excitation SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID PULSES; ABLATION; PLASMA AB A model is presented to relate picosecond laser induced thermionic electron emission to the carrier and phonon dynamics of semiconductors. Silicon is chosen as a model material since its optical and thermal properties are well characterized. The temporal profiles of thermionic emission current and total electron yield are obtained as a function of incident laser fluence for different surface conditions, below the silicon surface melting threshold. Two distinct regimes have been found for the dependence of the electron yield on the laser fluence due to thermionic emission and this behavior is related to Auger recombination. C1 Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Mech Engn, Berkeley, CA 94720 USA. RP Mao, SS (reprint author), Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. NR 20 TC 3 Z9 3 U1 1 U2 2 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD APR 15 PY 1998 VL 83 IS 8 BP 4462 EP 4465 DI 10.1063/1.367207 PG 4 WC Physics, Applied SC Physics GA ZJ989 UT WOS:000073273900073 ER PT J AU Ang, LK Lau, YY Gilgenbach, RM Spindler, HL Lash, JS Kovaleski, SD AF Ang, LK Lau, YY Gilgenbach, RM Spindler, HL Lash, JS Kovaleski, SD TI Surface instability of multipulse laser ablation on a metallic target SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID FILMS; SCATTERING; SCHLIEREN; DYNAMICS; ALUMINUM; PLUMES; VACUUM; GAS AB Large scale wavelike patterns are observed on an aluminum surface after it is ablated by a series of KrF laser pulses (248 nm, 40 ns, 5 J/cm(2)). These surface structures have a wavelength on the order of 30 mu m, much longer than the laser wavelength. We postulate that these wave patterns are caused by the Kelvin-Helmholtz instability at the interface between the molten aluminum and the plasma plume. A parametric study is given in terms of the molten layer's thickness and of the spatial extent and kinetic energy density in the laser-produced plasma plume. Also included is an estimate of the cumulative growth in a multipulse laser ablation experiment. These estimates indicate that the Kelvin-Helmholtz instability is a viable mechanism for the formation of the large scale structures. (C) 1998 American Institute of Physics. C1 Univ Michigan, Dept Nucl Engn & Radiol Sci, Intense Energy Beam Interact Lab, Ann Arbor, MI 48109 USA. Univ Michigan, Appl Phys Program, Ann Arbor, MI 48109 USA. Boeing Corp, Seattle, WA USA. Sandia Natl Labs, Albuquerque, NM USA. RP Ang, LK (reprint author), Univ Michigan, Dept Nucl Engn & Radiol Sci, Intense Energy Beam Interact Lab, Ann Arbor, MI 48109 USA. RI ANG, Lay Kee/F-8115-2015; OI ANG, Lay Kee/0000-0003-2811-1194; Kovaleski, Scott/0000-0002-5831-6388 NR 27 TC 25 Z9 25 U1 0 U2 3 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD APR 15 PY 1998 VL 83 IS 8 BP 4466 EP 4471 DI 10.1063/1.367208 PG 6 WC Physics, Applied SC Physics GA ZJ989 UT WOS:000073273900074 ER PT J AU Huang, DH Lyo, SK AF Huang, DH Lyo, SK TI Magnetically tuned wide-band quantum well infrared photodetectors SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID INTERSUBBAND TRANSITIONS; MULTIQUANTUM WELLS; DETECTOR; GAAS/ALGAAS; MODULATION AB The electron eigenstates of double quantum well system in an in-plane magnetic field are calculated accurately using the density-functional theory which includes the Coulomb interaction between electrons. The absorption coefficient as a function of the probe photon energy is further calculated using the self-consistent-held theory which takes into account many-body effects on the optical intersubband transitions. The dependence of the absorption spectra on the magnetic field, temperature, electron density, well and middle-barrier widths, quantum-well symmetry, and electric field has been studied extensively. It provides an unconventional approach for designing a tunable wide-band quantum well infrared photodetector by applying an in-plane magnetic field. C1 USAF, Phillips Lab, PL, TMR, Kirtland AFB, NM 87117 USA. Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Huang, DH (reprint author), USAF, Phillips Lab, PL, TMR, 3550 Aberdeen Ave SE,Bldg 426, Kirtland AFB, NM 87117 USA. EM huangd@plk.af.mil NR 25 TC 1 Z9 1 U1 1 U2 1 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD APR 15 PY 1998 VL 83 IS 8 BP 4531 EP 4539 DI 10.1063/1.367216 PG 9 WC Physics, Applied SC Physics GA ZJ989 UT WOS:000073273900085 ER PT J AU Salsbury, FR Harris, RA AF Salsbury, FR Harris, RA TI A nonlocal current density functional for magnetic responses SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article AB A nonlocal current density which is a gauge invariant functional of the electron density in the absence of the magnetic field is constructed. Unlike local functionals, which reduce to the Thomas-Fermi current density in the limit of zero gradients, the new functional treats diamagnetism exactly. Additionally, unlike earlier local functionals, the new functional has the capacity to support net paramagnetism. The full magnetic susceptibility and chemical shielding tensor density functionals are also derived. (C) 1998 American Institute of Physics. [S0021-9606(98)03115-8]. C1 Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. RP Salsbury, FR (reprint author), Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. RI Salsbury, Freddie/A-5923-2008 NR 19 TC 7 Z9 7 U1 0 U2 3 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD APR 15 PY 1998 VL 108 IS 15 BP 6102 EP 6108 DI 10.1063/1.476319 PG 7 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA ZH114 UT WOS:000073073700006 ER PT J AU Stimson, S Evans, M Ng, CY Hsu, CW Heimann, P Destandau, C Chambaud, G Rosmus, P AF Stimson, S Evans, M Ng, CY Hsu, CW Heimann, P Destandau, C Chambaud, G Rosmus, P TI High resolution vacuum ultraviolet pulsed field ionization photoelectron band for OCS+(X-2 Pi): An experimental and theoretical study SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID ROVIBRONIC SPECTRUM; VIBRONIC STRUCTURE; PHOTO-IONIZATION; STATE SELECTION; MOLECULAR-IONS; OCS; SPECTROSCOPY; ENERGY; COS+; PHOTOIONIZATION AB The vacuum ultraviolet pulsed field ionization photoelectron (PFI-PE) band for OCS+(X (2) Pi) in the energy region of 11.09-11.87 eV has been measured using high resolution monochromatized synchrotron radiation, The ionization energies (IEs) for the formation of the (0,0,0) X (2) Pi(3/2) and (0,0,0) (2) Pi(1/2) states of OCS+ are determined to be 11.1831+/-0.0005 and 11.2286+/-0.0005 eV, respectively, yielding a value of 367+/-1.2 cm(-1) for the spin-orbit splitting. Using the internally contracted multireference configuration interaction approach, three-dimensional potential energy functions (PEFs) for the OCS+(X (2) Pi) state have been generated and used in the variational Renner-Teller calculations of the vibronic states. The energies of all vibronic states (J=P) for J=1/2, 3/2, 5/2, and 7/2 have been computed in the energy range of approximate to 4000 cm(-1) above the IE[OCS+(X (2) Pi(3/2))] for the assignment of the experimental spectrum. By a minor modification of the nb initio PEFs, good correlations are found between the experimental and theoretical Renner-Teller structures. Similar to the PFI-PE bands for CO2+(X (2) Pi(g)) and CS2+(X (2) Pi(g)), weak transitions have been detected in the PFI-PE band for OCS+(X (2) Pi), which are forbidden in the Franck-Condon approximation. The nonvanishing single-photon ionization cross sections involving the excitation of the bending vibrational modes of OCS+, CO2+, and CS2+, in their ground electronic states are attributed to the symmetries of the geometry-dependent electronic transition dipole operator components. (C) 1998 American Institute of Physics. [S0021-9606(98)00415-2]. C1 US DOE, Ames Lab, Ames, IA 50011 USA. Iowa State Univ, Dept Chem, Ames, IA 50011 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Chem Sci, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Accelerator & Fus Res, Berkeley, CA 94720 USA. Univ Marne la Vallee, Theoret Chem Grp, F-93166 Noisy Le Grand, France. RP US DOE, Ames Lab, Ames, IA 50011 USA. EM cyng@ameslab.gov; p@rosmus.univ-mlv.fr RI Leonard, Celine/F-7283-2012 OI Leonard, Celine/0000-0002-0642-9655 NR 45 TC 40 Z9 40 U1 1 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 APR 15 PY 1998 VL 108 IS 15 BP 6205 EP 6214 DI 10.1063/1.476027 PG 10 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA ZH114 UT WOS:000073073700015 ER PT J AU Schenter, GK AF Schenter, GK TI A quantum statistical mechanical study of the enthalpy of formation of the water dimer SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID INFRARED PREDISSOCIATION SPECTRA; MOLECULAR-DYNAMICS SIMULATIONS; AQUEOUS IONIC CLUSTERS; CENTROID-DENSITY; AB-INITIO; SPECTROSCOPY; ASSOCIATION; ABINITIO; ENERGY; BEAM AB Monte Carlo simulations of quantum statistical mechanical properties using the Feynman path integral method were carried out over a temperature range from 50 to 400 K to study the energetics of the water dimer (H2O)(2). These results were then used to understand the relation between estimates of the enthalpy of formation obtained from recent ab initio electronic structure calculations and estimates of the enthalpy of formation deduced from experimental measurements of thermal conductivity, second virial coefficients and submillimeter spectroscopy. The full quantum mechanical and anharmonic theoretical results were compared to results obtained from classical mechanical simulation and those obtained from a quantum mechanical harmonic analysis. In performing the analysis for temperatures above 200 K, the definition of a water dimer becomes poorly defined as thermal activation leading to dissociation becomes more probable. The calculated enthalpy of the dimer is strongly dependent on the manner in which trapped and independent monomer species are defined. To address these issues we employ an energy threshold as a dividing surface to separate trapped dimers from those that eventually dissociate on the time scale of an experiment. Approximate quantum mechanical expressions that are consistent with an energy definition of the water dimer were introduced and used in the simulation. It is found that experimental observations are consistent with theoretical calculations once a characteristic time scale for the experimental technique is identified. (C) 1998 American Institute of Physics. [S0021-9606(98)50515-6]. C1 Pacific NW Lab, Environm Mol Sci Lab, Richland, WA 99352 USA. RP Schenter, GK (reprint author), Pacific NW Lab, Environm Mol Sci Lab, POB 999, Richland, WA 99352 USA. RI Schenter, Gregory/I-7655-2014 OI Schenter, Gregory/0000-0001-5444-5484 NR 41 TC 27 Z9 27 U1 0 U2 9 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD APR 15 PY 1998 VL 108 IS 15 BP 6222 EP 6232 DI 10.1063/1.476029 PG 11 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA ZH114 UT WOS:000073073700017 ER PT J AU Song, YQ Goodson, BM Sheridan, B de Swiet, TM Pines, A AF Song, YQ Goodson, BM Sheridan, B de Swiet, TM Pines, A TI Effects of diffusion on magnetic resonance imaging of laser-polarized xenon gas SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID EDGE ENHANCEMENT; HYPERPOLARIZED HE-3; NMR; RELAXATION; XE-129 AB Molecular diffusion during the application of magnetic field gradients can distort magnetic resonance images. A systematic characterization of these distortions in one dimension was performed using highly spin-polarized xenon gas. By varying the strength of the applied gradient and the geometric dimension of the sample, the evolution of these image distortions between the regimes of strong and weak diffusion was observed. These results are compared with numerical simulations. By directly measuring the displacement distribution of the polarized xenon atoms, it is shown that in the weak-diffusion regime the image distortions originate from the restricted diffusive motion near the sample boundaries, in agreement with previous theoretical work. Additionally, it is shown that the effects of diffusion can be utilized to enhance the contrast between the boundaries and bulk in the images of polarized gas samples, and thus may be exploited as a means of boundary detection in such systems. (C) 1998 American Institute of Physics. [S0021-9606(98)02915-8]. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. RP Song, YQ (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. OI Goodson, Boyd/0000-0001-6079-5077 NR 24 TC 33 Z9 33 U1 1 U2 7 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD APR 15 PY 1998 VL 108 IS 15 BP 6233 EP 6239 DI 10.1063/1.476030 PG 7 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA ZH114 UT WOS:000073073700018 ER PT J AU Skurski, P Gutowski, M AF Skurski, P Gutowski, M TI Theoretical study of the dipole-bound anion (H2O...NH3)(-) SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID ABINITIO ELECTRONIC-STRUCTURE; FRANCK-CONDON PRINCIPLE; AMMONIA WATER COMPLEX; GROUND-STATE; VIBRONIC TRANSITIONS; POLYATOMIC-MOLECULES; DYNAMICAL SYMMETRY; BASIS-SETS; ENERGETICS; NITROMETHANE AB The adiabatic electron detachment energy for (H2O...NH3)(-) has been found to be 109 cm(-1) at the coupled-cluster level of theory with single, double, and noninteractive triple excitations (CCSD(T)), to be compared with the recent experimental result of 123-129 cm(-1) obtained by Abdoul-Carime et al. [Z. Phys. D 40, 55 (1997)]. The stationary points on the potential energy surface of the neutral and anionic dimer have been determined at the second-order Moller-Plesset level of theory. Our results indicate that the second-order dispersion interaction between the loosely bound electron and electrons of the neutral dimer is as important as the electrostatic electron-dipole stabilization. The higher-order electron correlation corrections are also very important and the CCSD(T) electron binding energy is approximately four times larger than the Koopmans theorem estimation. In addition, the hydrogen bond in H2O...NH3 is susceptible to a deformation upon attachment of an electron. This deformation enhances both the electrostatic and dispersion components of the electron binding energy. The calculated Franck-Condon factors indicate that neutral dimers formed in electron photodetachment experiments may be vibrationally excited in both soft intermolecular and stiff intramolecular modes. The theoretical photoelectron spectrum based on the calculated Franck-Condon factors is reported. (C) 1998 American Institute of Physics. [S0021-9606(98)01315-4]. C1 Univ Gdansk, Dept Chem, PL-80952 Gdansk, Poland. Univ Utah, Dept Chem, Salt Lake City, UT 84112 USA. Pacific NW Lab, Solid State Theory Grp, Richland, WA 99352 USA. RP Gutowski, M (reprint author), Univ Gdansk, Dept Chem, PL-80952 Gdansk, Poland. NR 45 TC 43 Z9 43 U1 0 U2 1 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD APR 15 PY 1998 VL 108 IS 15 BP 6303 EP 6311 DI 10.1063/1.476037 PG 9 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA ZH114 UT WOS:000073073700026 ER PT J AU Bililign, S Feigerle, CS Miller, JC Velegrakis, M AF Bililign, S Feigerle, CS Miller, JC Velegrakis, M TI Nonstatistical bond breaking in the multiphoton ionization/dissociation of [Fe(CO)(5)](m)Ar-n clusters SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID GAS VANDERWAALS COMPLEXES; PHOTO-DISSOCIATION; IRON PENTACARBONYL; MOLECULAR CLUSTERS; LASER PHOTOLYSIS; METAL-CARBONYLS; ION CHEMISTRY; NITRIC-OXIDE; FE(CO)5; IONIZATION AB Photoionization of iron pentacarbonyl/argon clusters with 30 ps, 266 nm laser pulses results in the ultimate detection of iron ions solvated with argon atoms. Clusters such as Fem+Arn (m = 1,2; n = 1-26) are readily observed following the laser-induced decarbonylation of the [Fe(CO)(5)](m)Ar-n species formed in the supersonic jet. An interesting intensity alternation of the Fe+Arn ions is observed up to a magic number at n = 6, after which a monotonically decreasing intensity pattern is noted. The pattern is similar to a more extensive spectrum (with additional magic numbers) observed in separate experiments where metallic iron is laser ablated into a supersonic flow of argon, krypton, or xenon, and the resulting cluster ions are detected in a reflectron mass spectrometer. In another experiment in the latter apparatus, the sputtering of iron into a mixture of carbon monoxide and argon shows the relative reactivity of Fe+ to form Fe+Arn and Fe+((C) over bar)(n) ions. Mechanisms for the energy disposal during the ionization/dissociation process are discussed. Additionally, the intensity pattern of iron-rare gas clusters, Fe+(RG)(n), is discussed in the context of structural arguments which have previously been applied successfully to a large number of metal-rare gas systems. (C) 1998 American Institute of Physics. [S0021-9606(98)03615-0]. C1 Oak Ridge Natl Lab, Biochem & Biophys Sect, Oak Ridge, TN 37831 USA. Univ Tennessee, Dept Chem, Knoxville, TN 37996 USA. Fdn Res & Technol Hellas, Inst Elect Struct & Laser, FORTH, IESL, Heraklion 71110, Crete, Greece. N Carolina Agr & Technol State Univ, Dept Phys, Greensboro, NC 27411 USA. RP Bililign, S (reprint author), Oak Ridge Natl Lab, Biochem & Biophys Sect, POB 2008, Oak Ridge, TN 37831 USA. RI Velegrakis, Michalis/F-7810-2011 NR 66 TC 19 Z9 19 U1 0 U2 3 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD APR 15 PY 1998 VL 108 IS 15 BP 6312 EP 6319 DI 10.1063/1.476038 PG 8 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA ZH114 UT WOS:000073073700027 ER PT J AU Salian, UA AF Salian, UA TI Microcanonical temperature and "heat capacity" computation of Lennard-Jones clusters under isoergic molecular dynamics simulation SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID MONTE-CARLO SIMULATIONS; PHASE COEXISTENCE; ATOMIC CLUSTERS; FINITE SYSTEMS; MAGIC NUMBERS; TRANSITION; BEHAVIOR; LIQUID; WALKING AB The cumulated distribution of velocity components of atoms of a cluster in a constant energy classical molecular dynamics simulation is found to fit very well with Maxwellian distribution. This enables, with carefully prepared initial configurations, a cluster as small as containing just four atoms to be viewed to constitute a canonical ensemble in itself. In addition, the statistical distribution of velocity components provides an unambiguous, independent and robust method of obtaining the thermodynamic temperature of an isolated system. The temperature thus obtained differs from the conventionally used kinetic temperature by a fixed factor of (3N-6)/(3N), implications of which are discussed. A new procedure of sampling the configurational energy landscape is introduced. and the "heat capacity" curve computed using this method--which is actually the second moment of the potential energy fluctuations as a function of cluster kinetic energy--exhibits its usefulness by clearly demonstrating the two stage melting of Ar-55. (C) 1998 American Institute of Physics. [S0021-9606(98)50815-X]. C1 Inst Phys, Bhubaneswar 751005, Orissa, India. RP Salian, UA (reprint author), Argonne Natl Lab, Div Chem, 9700 S Cass Ave, Argonne, IL 60439 USA. NR 27 TC 10 Z9 10 U1 1 U2 8 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD APR 15 PY 1998 VL 108 IS 15 BP 6342 EP 6346 DI 10.1063/1.476040 PG 5 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA ZH114 UT WOS:000073073700030 ER PT J AU Murdoch, KM Cavellec, R Simoni, E Karbowiak, M Hubert, S Illemassene, M Edelstein, NM AF Murdoch, KM Cavellec, R Simoni, E Karbowiak, M Hubert, S Illemassene, M Edelstein, NM TI Laser spectroscopy and crystal field analysis of Cm3+ diluted in Cs2NaYCl6 SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID CUBIC-SYMMETRY SITE; EMISSION-SPECTRA; LANTHANIDE IONS; ELPASOLITE; CS2NALNCL6; LUMINESCENCE; SYSTEMS; THO2; U3+ AB Laser selective excitation, excited state absorption, two-photon absorption, and fluorescence line narrowing techniques have been used to investigate the electronic energy level structure of the Cm3+ ion diluted in the host crystal Cs2NaYCl6. In this crystal the Cm3+ ion replaces a Y3+ ion at an octahedral site (O-h symmetry). Analysis of these spectra resulted in the assignment of 52 energy levels, which were fitted to the parameters of an empirical Hamiltonian with a rms deviation of 57 cm(-1). Many of the Gamma(8) symmetry levels exhibited small splittings, which was indicative of a site symmetry lower than O-h. The energies of the most prominent vibronic features have been measured and assigned to specific vibrational modes of the CmCl63- moiety or to lattice modes. The lifetimes of four fluorescing levels have been obtained at room and liquid helium temperatures. These were analyzed to determine the processes which contribute to the relaxation of an excited Cm3+ ion in this host. Blue P-6(5/2)-->S-7/2 upconversion fluorescence was observed when pumping the orange S-8(7/2)-->D-6(7/2) absorption transitions and explained by a phonon-assisted energy transfer mechanism. (C) 1998 American Institute of Physics. [S0021-9606(98)02615-4]. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Div Chem Sci, Berkeley, CA 94720 USA. Inst Phys Nucl, CNRS, IN2P3, F-91406 Orsay, France. RP Univ Calif Berkeley, Lawrence Berkeley Lab, Div Chem Sci, Berkeley, CA 94720 USA. NR 32 TC 16 Z9 16 U1 1 U2 2 PU AMER INST PHYSICS PI MELVILLE PA 1305 WALT WHITMAN RD, STE 300, MELVILLE, NY 11747-4501 USA SN 0021-9606 EI 1089-7690 J9 J CHEM PHYS JI J. Chem. Phys. PD APR 15 PY 1998 VL 108 IS 15 BP 6353 EP 6361 DI 10.1063/1.476042 PG 9 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA ZH114 UT WOS:000073073700032 ER PT J AU Machesky, ML Wesolowski, DJ Palmer, DA Ichiro-Hayashi, K AF Machesky, ML Wesolowski, DJ Palmer, DA Ichiro-Hayashi, K TI Potentiometric titrations of rutile suspensions to 250 degrees C SO JOURNAL OF COLLOID AND INTERFACE SCIENCE LA English DT Article DE rutile; metal oxide; surface complexation; potentiometric titration; adsorption; PZC ID SODIUM-CHLORIDE SOLUTIONS; 4-LAYER COMPLEXATION MODEL; ELECTRICAL DOUBLE-LAYER; ZERO CHARGE; TEMPERATURE-DEPENDENCE; WATER INTERFACE; ION ADSORPTION; METAL-OXIDES; ELECTROLYTE/OXIDE INTERFACE; THEORETICAL PREDICTION AB A stirred hydrogen electrode concentration cell was used to conduct potentiometric titrations of rutile suspensions from 25 to 250 degrees C in NaCl and tetramethylammonium chloride media (0.03 to 1.1 m). Hydrothermal pretreatment of the rutile improved titration reproducibility, decreased titration hysteresis, and facilitated determination of the point of zero net proton charge (pHznpc). These pHznpc values are 5.4, 5.1, 4.7, 4.4, 4.3 (+/-0.2 pH units), and 4.2 (+/-0.3 pH units) at 25, 50, 100, 150, 200, and 250 degrees C, respectively. The difference between these pHznpc values and pK(w) (the neutral pH of water) is rather constant between 25 and 250 degrees C (-1.45 +/- 0.2). This constancy is useful for predictive purposes and, more fundamentally, may reflect similarities between the hydration behavior of surface hydroxyl groups and water. A three-layer, 1pKa surface complexation model with three adjustable parameters (two capacitance values and one counterion binding constant) adequately described all titration data. The most apparent trend in these data for pH values greater than the pHznpc was the increase in proton release (negative surface charge) with increasing temperature. This reflects more efficient screening by Na+ relative to Cl-. Replacing Na+ with the larger tetramethylammonium cation for some conditions resulted in decreased proton release due to the less efficient screening of negative surface charge by this larger cation. (C) 1998 Academic Press. C1 Illinois State Water Survey, Champaign, IL 61820 USA. Oak Ridge Natl Lab, Div Chem & Analyt Sci, Oak Ridge, TN 37831 USA. Tohoku Univ, Inst Mineral Petrol & Econ Geol, Sendai, Miyagi 98077, Japan. RP Machesky, ML (reprint author), Illinois State Water Survey, 2204 Griffith Dr, Champaign, IL 61820 USA. EM machesky@sws.uiuc.edu NR 67 TC 104 Z9 104 U1 2 U2 17 PU ACADEMIC PRESS INC ELSEVIER SCIENCE PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0021-9797 EI 1095-7103 J9 J COLLOID INTERF SCI JI J. Colloid Interface Sci. PD APR 15 PY 1998 VL 200 IS 2 BP 298 EP 309 DI 10.1006/jcis.1997.5401 PG 12 WC Chemistry, Physical SC Chemistry GA ZM295 UT WOS:000073524200012 ER PT J AU Wu, S Lipkowski, J Magnussen, OM Ocko, BM Wandlowski, T AF Wu, S Lipkowski, J Magnussen, OM Ocko, BM Wandlowski, T TI The driving force for (px root 3)<->(1x1) phase transition of Au(111) in the presence of organic adsorption: a combined chronocoulometric and surface X-ray scattering study SO JOURNAL OF ELECTROANALYTICAL CHEMISTRY LA English DT Article DE gold; organic adsorption; crystallographic structure ID SCANNING-TUNNELING-MICROSCOPY; ELECTROCHEMICAL INTERFACE; ELECTROLYTE INTERFACE; AU(100) SURFACES; SOLID ELECTRODES; METAL-SURFACES; RECONSTRUCTION; GOLD; REFLECTIVITY; DIFFRACTION AB In situ X-ray scattering and chronocoulometric experiments were performed to assess the influence of adsorption of pyridine, 2,2'-bipyridine and uracil on the driving force for the (p x root 3)-->(1 x 1) transition of the Au(111) surface. We have shown that the overall driving force is a combination of the driving force due to charge and the driving force due to the adsorbate. We have estimated the magnitude of the two driving forces and have given the upper and lower limits to this estimate. Our results show that the two driving forces are of comparable magnitude and that the interpretation of the surface reconstruction phenomena given in terms of either purely charge or a purely adsorbate effect is an oversimplification. (C) 1998 Elsevier Science S.A. All rights reserved. C1 Univ Guelph, Dept Chem, Guelph, ON N1G 2W1, Canada. Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. Univ Ulm, Dept Electrochem, D-89069 Ulm, Germany. RP Lipkowski, J (reprint author), Univ Guelph, Dept Chem, Guelph, ON N1G 2W1, Canada. EM lip-kowski@chembio.uoguelph.ca RI Thomas, Wandlowski/C-7251-2009 NR 51 TC 47 Z9 47 U1 0 U2 7 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0022-0728 J9 J ELECTROANAL CHEM JI J. Electroanal. Chem. PD APR 15 PY 1998 VL 446 IS 1-2 BP 67 EP 77 DI 10.1016/S0022-0728(97)00607-4 PG 11 WC Chemistry, Analytical; Electrochemistry SC Chemistry; Electrochemistry GA ZQ833 UT WOS:000073907500009 ER PT J AU Wereszczak, AA Kirkland, TP Ferber, MK Watkins, TR Yeckley, RL AF Wereszczak, AA Kirkland, TP Ferber, MK Watkins, TR Yeckley, RL TI The effects of residual alpha phase on the 1370 degrees C creep performance of yttria-doped HIPed silicon nitride SO JOURNAL OF MATERIALS SCIENCE LA English DT Article ID HIGH-TEMPERATURE STRENGTH; CERAMICS; CRYSTALLIZATION; TRANSFORMATION; DEFORMATION; COMPOSITES; BEHAVIOR; SI3N4 AB The creep behaviour at 1370 degrees C (2500 degrees F) of yttria-doped, hot isostatically pressed silicon nitride was examined as a function of residual alpha phase content. The pre-test silicon nitride materials had either 30% or 40% alpha phase content. The creep resistance was found to increase as the residual alpha phase content decreased. For equivalent times and stresses, the higher alpha-containing silicon nitride accumulated more creep strain and exhibited faster creep rates. The residual alpha phase decreased as a function of time at 1370 degrees C and converted to beta phase; it was also found that the alpha to beta phase transformation rate was enhanced by stress. In the absence of stress, the kinetics of the alpha to beta phase transformation at 1370 degrees C followed a first-order reaction. If a first-order reaction was assumed for the alpha to beta phase transformation in the presence of stress at 1370 degrees C, then the magnitude of the reaction rate constant for this transformation was twice as large for tensile stresses equal to or greater than 130 MPa than for the reaction rate constant describing the transformation with no applied stress. (C) 1998 Chapman & Hall. C1 Oak Ridge Natl Lab, High Temp Mat Lab, Oak Ridge, TN 37831 USA. St Gobain Norton Ind Ceram Corp, Northboro Res & Dev Ctr, Northboro, MA 01532 USA. RP Wereszczak, AA (reprint author), Oak Ridge Natl Lab, High Temp Mat Lab, Oak Ridge, TN 37831 USA. RI Watkins, Thomas/D-8750-2016; Wereszczak, Andrew/I-7310-2016 OI Watkins, Thomas/0000-0002-2646-1329; Wereszczak, Andrew/0000-0002-8344-092X NR 28 TC 16 Z9 16 U1 0 U2 0 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0022-2461 J9 J MATER SCI JI J. Mater. Sci. PD APR 15 PY 1998 VL 33 IS 8 BP 2053 EP 2060 DI 10.1023/A:1004354732648 PG 8 WC Materials Science, Multidisciplinary SC Materials Science GA ZH367 UT WOS:000073101400011 ER PT J AU Medellin-Rodriguez, FJ Phillips, PJ Lin, JS Avila-Orta, CA AF Medellin-Rodriguez, FJ Phillips, PJ Lin, JS Avila-Orta, CA TI Triple melting behavior of poly(ethylene terephthalate co-1,4-cyclohexylene dimethylene terephthalate) random copolyesters SO JOURNAL OF POLYMER SCIENCE PART B-POLYMER PHYSICS LA English DT Article DE random copolyesters; copolymers; crystallization; melting ID ANGLE X-RAY; LAMELLAR 2-PHASE SYSTEMS; POLY(ETHYLENE-TEREPHTHALATE); CRYSTALLIZATION; SCATTERING; POLYMERS; MORPHOLOGY AB The melting behavior of poly(ethylene terephthalate co-1,4-cyclohexylene dimethylene terephthalate) [PET/CT] random copolyesters has been studied. The basis of this analysis was the triple melting behavior of PET homopolymers, which is commonly observed after a period of isothermal crystallization followed by linear heating in a differential scanning calorimeter. Both ET and CT homopolymers are able to crystallize, and as a consequence, the copolymer morphology depends on the ET/CT ratio. It has been reported that at low CT concentrations, the ET units can crystallize with complete rejection of the CT units and that at high CT concentrations, the CT units can cocrystallize with the ET units. In the present work, low CT concentrations were selected, as they are completely rejected from the ET crystals. The purpose was to further test the hypothesis that in the triple melting behavior of PET homopolymers, the second DSC melting endotherm is related to secondary species crystallized by material rejected from the primary crystals. This concept arose from our previous work, where it was speculated that increasing the average molecular-weight of PET would enhance molecular entanglement and increase secondary crystallization. This process would give rise to a higher amount of species being rejected from the main crystals, i.e., an increase of secondary crystallization would occur, and as a consequence the second melting endotherm would be enhanced. Similar to the effect of molecular weight, such behavior has been observed as a function of rejected copolymer content. This gives support to our previously proposed step-like crystallization and melting mechanism for PET homopolymers, and has the potential to be extended to other high temperature semicrystalline polymeric systems. (C) 1998 John Wiley & Sons, Inc. C1 Univ Tennessee, Dept Mat Sci & Engn, Knoxville, TN 37996 USA. Univ Autonoma San Luis Potosi, Ctr Invest & Estudios Posgrado FCQ, San Luis Potosi 78210, Mexico. Oak Ridge Natl Lab, Div Solid State, Oak Ridge, TN 37831 USA. RP Phillips, PJ (reprint author), Univ Tennessee, Dept Mat Sci & Engn, Knoxville, TN 37996 USA. NR 31 TC 23 Z9 30 U1 2 U2 6 PU JOHN WILEY & SONS INC PI NEW YORK PA 605 THIRD AVE, NEW YORK, NY 10158-0012 USA SN 0887-6266 J9 J POLYM SCI POL PHYS JI J. Polym. Sci. Pt. B-Polym. Phys. PD APR 15 PY 1998 VL 36 IS 5 BP 763 EP 781 DI 10.1002/(SICI)1099-0488(19980415)36:5<763::AID-POLB4>3.0.CO;2-M PG 19 WC Polymer Science SC Polymer Science GA YY875 UT WOS:000072195900004 ER PT J AU Bull, LM Cheetham, AK Anupold, T Reinhold, A Samoson, A Sauer, J Bussemer, B Lee, Y Gann, S Shore, J Pines, A Dupree, R AF Bull, LM Cheetham, AK Anupold, T Reinhold, A Samoson, A Sauer, J Bussemer, B Lee, Y Gann, S Shore, J Pines, A Dupree, R TI A high-resolution(17)O NMR study of siliceous zeolite faujasite SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Article ID AB-INITIO CALCULATION; RESOLUTION O-17 NMR; WORKSTATION COMPUTERS C1 Univ Warwick, Dept Phys, Coventry CV4 7AL, W Midlands, England. Inst Mat Nantes, Lab Chim Solides, F-44322 Nantes 3, France. Estonian Acad Sci, Inst Chem Phys & Biophys, Tallinn, Estonia. Univ Calif Santa Barbara, Mat Res Lab, Santa Barbara, CA 93106 USA. Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. Humboldt Univ, Inst Chem, D-10117 Berlin, Germany. Natl High Magnet Field Lab, Tallahassee, FL USA. RP Dupree, R (reprint author), Univ Warwick, Dept Phys, Coventry CV4 7AL, W Midlands, England. RI dupree, ray/F-6997-2012; Sauer, Joachim/B-7020-2016 OI Sauer, Joachim/0000-0001-6798-6212 NR 19 TC 74 Z9 75 U1 0 U2 14 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0002-7863 J9 J AM CHEM SOC JI J. Am. Chem. Soc. PD APR 15 PY 1998 VL 120 IS 14 BP 3510 EP 3511 DI 10.1021/ja9743001 PG 2 WC Chemistry, Multidisciplinary SC Chemistry GA ZJ097 UT WOS:000073179200032 ER PT J AU Burton, H AF Burton, H TI Cambridge quintet: A work of scientific speculation. SO LIBRARY JOURNAL LA English DT Book Review C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA USA. RP Burton, H (reprint author), Univ Calif Lawrence Livermore Natl Lab, Livermore, CA USA. NR 1 TC 0 Z9 0 U1 0 U2 0 PU BOWKER MAGAZINE GROUP CAHNERS MAGAZINE DIVISION PI NEW YORK PA 249 W 17TH ST, NEW YORK, NY 10011 USA SN 0363-0277 J9 LIBR J JI Libr. J. PD APR 15 PY 1998 VL 123 IS 7 BP 110 EP 110 PG 1 WC Information Science & Library Science SC Information Science & Library Science GA ZH489 UT WOS:000073116200193 ER PT J AU Schwartz, AJ Lassila, DH LeBlanc, MM AF Schwartz, AJ Lassila, DH LeBlanc, MM TI The effects of tungsten addition on the microtexture and mechanical behavior of tantalum plate SO MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING LA English DT Article DE microtexture; alloys; tungsten; tantalum ID TEXTURE; TEMPERATURE; FLOW AB Microtexture variations in annealed tantalum and tantalum-tungsten alloy plate materials have been studied by orientation imaging microscopy (OIM) and correlated with the mechanical behavior over a strain rate range of 10(-3) s(-1) to 3000 s(-1). Plates of nominally pure Ta and Ta-W alloys (2.5, 5 and 10 wt% W), approximate to 6 mm thick were mechanically tested quasistatically in compression and tension and dynamically via a split Hopkinson pressure bar and punch through shear tests. The results indicate that the unalloyed Ta exhibits anomalous mechanical responses such as inverse barreling or hourglassing in compression and multiple necks in tension, whereas the tungsten containing alloys deform homogeneously. OIM indicates severe texture banding in the pure Ta such that the fraction of grains with near [111] normals is very high near the centerline of the plate and decreases toward the surfaces. Large deviations from this generic description occur from specimen to specimen. Microtexture analyses of the Ta-W alloys reveals no significant texture gradients but rather a change in overall texture from a [111] fiber to a [100] cube texture with the addition of 2.5 wt% tungsten. The evidence suggests that the addition of tungsten results in a more uniform texture and thus homogeneous mechanical response. (C) 1998 Published by Elsevier Science S.A. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Schwartz, AJ (reprint author), Univ Calif Lawrence Livermore Natl Lab, POB 808,L-355, Livermore, CA 94550 USA. NR 26 TC 11 Z9 12 U1 0 U2 2 PU ELSEVIER SCIENCE SA 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 APR 15 PY 1998 VL 244 IS 2 BP 178 EP 190 DI 10.1016/S0921-5093(97)00690-4 PG 13 WC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Science & Technology - Other Topics; Materials Science; Metallurgy & Metallurgical Engineering GA ZJ922 UT WOS:000073267200005 ER PT J AU Biner, SB AF Biner, SB TI Characteristics of interface cracks in creep regime SO MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING LA English DT Article DE creep regime; graded/layered materials; interface cracks ID GRAIN-BOUNDARY CAVITATION; DIFFUSIVE CAVITATION; BIMATERIAL INTERFACES; SILICON-CARBIDE; TIP FIELDS; GROWTH; POLYCRYSTALS; STRESS; FACETS AB In this study, the growth behavior of interface cracks in bimaterials and in graded/layered materials at creep regime was studied. In the first part of the study, the evolution of the time-dependent stress states ahead of the stationary interface cracks was elucidated using a finite element model. In the second part, the observed stress states were incorporated into a creep crack growth model resulting from the growth of creep cavities ahead of the interface cracks. The growth model includes the effects of material deposition resulting from the growth of creep cavities on the crack tip stress fields. The results indicate that in graded/layered materials under identical applied loading, both the location of the interface crack and the extent of the transitional layer strongly influence the amplitude of the stress field (C*) at steady state. Also, the time required to achieve the steady state varies considerably with these parameters. The growth rates of the interface cracks are much faster than the growth rate of a homogeneous crack in the fastest creeping sector of that interface. Due to large variation in the distribution of the stresses ahead of the interface cracks at creep regime, depending upon the location, the creep crack growth rates will be significantly different from each other under identical loading for a given graded/layered material. (C) 1998 Elsevier Science S.A. All rights reserved. C1 Iowa State Univ Sci & Technol, Ames Lab, Ames, IA 50011 USA. RP Biner, SB (reprint author), Iowa State Univ Sci & Technol, Ames Lab, Ames, IA 50011 USA. NR 45 TC 7 Z9 8 U1 1 U2 4 PU ELSEVIER SCIENCE SA 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 APR 15 PY 1998 VL 244 IS 2 BP 233 EP 249 DI 10.1016/S0921-5093(97)00645-X PG 17 WC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Science & Technology - Other Topics; Materials Science; Metallurgy & Metallurgical Engineering GA ZJ922 UT WOS:000073267200011 ER PT J AU Luo, X Eisaman, MD Gosnell, TR AF Luo, X Eisaman, MD Gosnell, TR TI Laser cooling of a solid by 21 K starting from room temperature SO OPTICS LETTERS LA English DT Article ID FREQUENCY UP-CONVERSION; CONDENSED-PHASE AB A fluorozirconate glass doped with trivalent ytterbium ions has been laser cooled in vacuo from 298 to 277 K by optical pumping of the ions at 1015 nm. The cooling effect arises from anti-Stokes fluorescence of the laser-excited ions and by virtue of the near-unit fluorescence quantum efficiency for Yb3+ in sufficiently pure solid hosts. The sample temperatures in the experiment are determined by measurement of the Yb3+ emission spectrum; the value of the observed temperature change from room temperature as a function of pump wavelength is successfully explained in terms of a simple two-level model that includes the effect of optical saturation. (C) 1998 Optical Society of America. C1 Univ Calif Los Alamos Natl Lab, Condensed Matter & Thermal Phys Grp, Los Alamos, NM 87545 USA. RP Luo, X (reprint author), Univ Calif Los Alamos Natl Lab, Condensed Matter & Thermal Phys Grp, MS E543, Los Alamos, NM 87545 USA. RI Eisaman, Matthew/E-8006-2011 OI Eisaman, Matthew/0000-0002-3814-6430 NR 7 TC 61 Z9 69 U1 1 U2 2 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA SN 0146-9592 J9 OPT LETT JI Opt. Lett. PD APR 15 PY 1998 VL 23 IS 8 BP 639 EP 641 DI 10.1364/OL.23.000639 PG 3 WC Optics SC Optics GA ZG942 UT WOS:000073055500025 PM 18084602 ER PT J AU Boggon, TJ Chayen, NE Snell, EH Dong, J Lautenschlager, P Potthast, L Siddons, DP Stojanoff, V Gordon, E Thompson, AW Zagalsky, PF Bi, RC Helliwell, JR AF Boggon, TJ Chayen, NE Snell, EH Dong, J Lautenschlager, P Potthast, L Siddons, DP Stojanoff, V Gordon, E Thompson, AW Zagalsky, PF Bi, RC Helliwell, JR TI Protein crystal movements and fluid flows during microgravity growth SO PHILOSOPHICAL TRANSACTIONS OF THE ROYAL SOCIETY A-MATHEMATICAL PHYSICAL AND ENGINEERING SCIENCES LA English DT Article; Proceedings Paper CT Meeting on Marangoni and Interfacial Phenomena in Materials Processing CY JUN 04-05, 1997 CL LONDON, ENGLAND SP Royal Soc DE protein crystallization; microgravity; interferometry; CCD video; crystal perfection; g-jitter; Marangoni convection ID CRYSTALLIZATION; FACILITIES AB The growth of protein crystals suitable for X-ray crystal structure analysis is all important topic. The methods of protein crystal growth are under increasing study whereby different methods are being compared via diagnostic monitoring including charge coupled device (CCD) video and interferometry. The quality (perfection) of protein crystals is now being evaluated by mosaicity analysis (rocking curves) and X-rar topographic images as well as the diffraction resolution limit and overall data quality. Choice of a liquid-liquid linear crystal-growth geometry and microgravity can yield a spatial stability of growing crystals and fluid, as seen in protein crystallization experiments on the uncrewed platform EURECA. A similar geometry used within the Advanced Protein Crystallization Facility (APCF) onboard the crewed shuttle missions SpaceHab-01 and IML-2, however, has shown by CCD video some lysozyme crystal movement through the mother liquor. Moreover, spurts and lulls of growth of a stationary lysozyme protein crystal that was probably fixed to the crystal-growth reactor wall suggests g-jitter stimulated movement of fluid on IML-2, thus transporting new protein to the growing crystal faces. In yet another study, use of a hanging drop vapour diffusion geometry on the IML-2 shuttle mission showed, again via CCD video monitoring, growing apocrustacyanin C-1 protein crystals executing near cyclic movement, reminiscent of Marangoni convection flow of fluid, the crystals serving as 'markers' of the fluid flow. These observations demonstrated that the use of vapour diffusion geometry did not yield spatially stable crystal position or fluid conditions for a solely protein diffusive regime to be realized. Indeed mosaicity evaluation of those vapour diffusion-grown apocrustacyanin C-1 crystals showed inconsistent protein crystal quality although the best crystal studied was microgravity grows. Ln general, realizing perfect conditions for protein crystal growth, of absence of movement of crystal or fluid, requires not only the correct choice of geometry but also the avoidance of low-frequency (less than or similar to 5 Hz) g-jitters. A review is given here of existing results and experience over several microgravity missions. Some comment, is given on gel protein crystal growth in attempts to 'mimic' the benefits of microgravity on Earth. Finally, the recent new results from our experiments on the shuttle mission LMS are described. These results include CCD video as well as interferometry during the mission, followed, on return to Earth, by reciprocal space mapping at the NSLS, Brookhaven, and full X-ray data collection on LMS and Earth control lysozyme crystals. Diffraction data recorded from LMS and ground control apocrustacyanin C-1 crystals are also described. C1 Univ Manchester, Dept Chem, Struct Chem Sect, Manchester M13 9PL, Lancs, England. Univ London Imperial Coll Sci Technol & Med, Dept Biophys, Blackett Lab, London SW7 2BZ, England. NASA, Struct Biol Lab, Huntsville, AL 35812 USA. Dornier Syst GmbH, Raumfahrt Infrastrukt, D-88039 Friedrichshafen, Germany. NSLS, Brookhaven Natl Lab, Upton, NY 11973 USA. European Synchrotron Radiat Facil, F-38043 Grenoble, France. Inst Biol Struct, Inst Cristallog Macromol, F-38027 Grenoble, France. EMBL, F-38043 Grenoble, France. Univ London, Royal Holloway & Bedford New Coll, Dept Biochem, Egham TW20 0EX, Surrey, England. Acad Sinica, Inst Biophys, Beijing 100101, Peoples R China. RP Boggon, TJ (reprint author), Univ Manchester, Dept Chem, Struct Chem Sect, Oxford Rd, Manchester M13 9PL, Lancs, England. RI stojanoff, vivian /I-7290-2012; Helliwell, John /C-4587-2014 OI stojanoff, vivian /0000-0002-6650-512X; Helliwell, John /0000-0002-0520-7540 NR 23 TC 26 Z9 26 U1 0 U2 3 PU ROYAL SOC PI LONDON PA 6-9 CARLTON HOUSE TERRACE, LONDON SW1Y 5AG, ENGLAND SN 1364-503X J9 PHILOS T R SOC A JI Philos. Trans. R. Soc. A-Math. Phys. Eng. Sci. PD APR 15 PY 1998 VL 356 IS 1739 BP 1045 EP 1061 PG 17 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA ZM298 UT WOS:000073524500031 ER PT J AU Boettger, JC AF Boettger, JC TI Scalar-relativistic linear combinations of Gaussian-type-orbitals technique for crystalline solids SO PHYSICAL REVIEW B LA English DT Article ID TOTAL-ENERGY; METALS; TRANSITION; FORMALISM; ALUMINUM; ELECTRON; SYSTEMS; ATOMS AB The first nonperturbative implementation of scalar relativity in an all-electron linear combinations of Gaussian-type-orbitals methodology for crystalline solids is reported. Test calculations on fee gold yield bulk and one-electron properties that are indistinguishable from results obtained with other all-electron, scalar-relativistic density-functional techniques. This development paves the way for joint cluster and crystalline calculations on heavy-atom systems using a single all-electron, full-potential technique. [S0163-1829(98)04212-X]. C1 Univ Calif Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. RP Boettger, JC (reprint author), Univ Calif Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. NR 27 TC 29 Z9 29 U1 0 U2 2 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 EI 1550-235X J9 PHYS REV B JI Phys. Rev. B PD APR 15 PY 1998 VL 57 IS 15 BP 8743 EP 8746 DI 10.1103/PhysRevB.57.8743 PG 4 WC Physics, Condensed Matter SC Physics GA ZJ480 UT WOS:000073219900002 ER EF