FN Thomson Reuters Web of Science™ VR 1.0 PT J AU Hansen, DC Corcoran, SG Waite, JH AF Hansen, DC Corcoran, SG Waite, JH TI Enzymatic tempering of a mussel adhesive protein film SO LANGMUIR LA English DT Article ID MYTILUS-EDULIS-L; OXIDASE; BYSSUS; DOPA; NMR AB An adhesive protein isolated from the marine mussel Mytilus edulis has been adsorbed to highly oriented pyrolytic graphite and enzymatically oxidized to yield a sclerotized film that is tightly bound to the substrate. Atomic force microscopy was used to image the surface and the adsorbed biopolymer, indicating uniform coverage of the substrate within 1 s of adsorption time from solution. Film thicknesses of the adsorbed protein films were estimated to be 25 and 73 Angstrom for the sclerotized films. Imaging forces ranging from less than or equal to 20 to greater than or equal to 600 nN were used to determine the stability of adhesive protein films without and with added catechol oxidase, respectively. Results indicate that the resistance of adhesive protein films to displacement can be enhanced 10-fold by enzymatic oxidation. Oxidation presumably leads to formation of covalent crosslinks between adsorbed protein chains. C1 EG&G Idaho Inc, Oak Ridge, TN 37831 USA. USN, Res Lab, Washington, DC 20375 USA. Univ Delaware, Dept Chem & Biochem, Newark, DE 19716 USA. RP Hansen, DC (reprint author), EG&G Idaho Inc, Oak Ridge, TN 37831 USA. NR 23 TC 36 Z9 36 U1 0 U2 13 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0743-7463 J9 LANGMUIR JI Langmuir PD MAR 3 PY 1998 VL 14 IS 5 BP 1139 EP 1147 DI 10.1021/la970881w PG 9 WC Chemistry, Multidisciplinary; Chemistry, Physical; Materials Science, Multidisciplinary SC Chemistry; Materials Science GA ZA685 UT WOS:000072390800026 ER PT J AU Chang, FRC Skipper, NT Sposito, G AF Chang, FRC Skipper, NT Sposito, G TI Monte Carlo and molecular dynamics simulations of electrical double-layer structure in potassium-montmorillonite hydrates SO LANGMUIR LA English DT Article ID SWELLING CLAY-MINERALS; COMPUTER-SIMULATION; POTENTIAL FUNCTIONS; WATER; DISPERSIONS; SMECTITES; IONS; K+ AB Monte Carlo and molecular dynamics simulations of interlayer molecular structure in the one-, two-, and (hypothetical) three-layer hydrates of K-montmorillonite were performed concurrently in order to elucidate counterion speciation and water structure in the electrical double layer of this clay mineral. Calculated layer spacings, interlayer water potential energies, and counterion mobilities were in agreement with available experimental data. In the one-layer hydrate, both outer-sphere and inner-sphere surface complexes of K(+) were observed, the latter always near sites of tetrahedral charge substitution, with the counterion species exchanging readily on the simulation time scale (up to 200 ps). In the two-and three-layer hydrates, the surface complexes persisted, but an incipient diffuse layer of counterions also was observed, with all three types of surface species engaging in sluggish exchange. Water molecules in the one-layer hydrate resided at the interlayer midplane, whereas ill the two-layer hydrate they lay in two planes between outer-and inner-sphere K(+) surface complexes, as veil as at the midplane. Hydrogen bonds in the one-layer hydrate were longer and more bent than in bulk liquid water. For all three hydrates, water and cation interlayer mobilities remained below those observed in bulk solution, principally because of the restricted geometry and the retarding effect of clay layer surface charge. Most of our results can be understood in terms of the weak solvation of the counterions by water molecules, which permits significant competition between K(+) and water protons for negatively charged sites in the clay mineral. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Div Earth Sci, Berkeley, CA 94720 USA. Columbia Univ, Lamont Doherty Geol Observ, Palisades, NY 10964 USA. UCL, Dept Phys & Astron, London WC1E 6BT, England. RP Sposito, G (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Div Earth Sci, Mail Stop 90-1116, Berkeley, CA 94720 USA. EM gsposito@nature.berkeley.edu RI Skipper, Neal/F-3663-2012 OI Skipper, Neal/0000-0003-2940-3084 NR 35 TC 92 Z9 97 U1 1 U2 22 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0743-7463 J9 LANGMUIR JI Langmuir PD MAR 3 PY 1998 VL 14 IS 5 BP 1201 EP 1207 DI 10.1021/la9704720 PG 7 WC Chemistry, Multidisciplinary; Chemistry, Physical; Materials Science, Multidisciplinary SC Chemistry; Materials Science GA ZA685 UT WOS:000072390800034 ER PT J AU Gudi, S Nolan, JP Frangos, JA AF Gudi, S Nolan, JP Frangos, JA TI Modulation of GTPase activity of G proteins by fluid shear stress and phospholipid composition SO PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA LA English DT Article ID BETA-ADRENERGIC-RECEPTOR; HUMAN ENDOTHELIAL-CELLS; CALCIUM-ION TRANSPORT; ADENYLATE-CYCLASE; BINDING; MEMBRANES; VESICLES; MEROCYANINE-540; TRANSDUCTION; ACTIVATION AB Mechanical forces arising from strain, pressure, and fluid shear stress are sensed by cells through an unidentified mechanoreceptor(s) coupled to intracellular signaling pathways. In vascular endothelial cells, fluid shear stress is transduced via pathway(s) involving heterotrimeric guanine nucleotide-binding proteins (G proteins) by molecular mechanisms that are unknown. In the present study, we investigated the activation of purified G proteins reconstituted into phospholipid vesicles. Vesicles containing G proteins were loaded with [gamma-P-32]GTP and subjected to physiological Levels of fluid shear stress in a cone-and-plate viscometer. Steady-state GTP hydrolysis was measured as an index of G protein function. Shear stress (0-30 dynes/cm(2)) activated G proteins in dose-dependent manner (0.48-4.6 pmol/min per pg of protein). Liposomes containing lysophosphatidylcholine (30 mol %) or treated with benzyl alcohol (40 mM), conditions that increase bilayer fluidity, exhibited 3- to 5-fold enhancement of basal GTPase activity. Conversely, incorporation of cholesterol (24 mol %) into liposomes reduced the activation of G proteins by shear. These results demonstrate the ability of the phospholipid bilayer to mediate the shear stress-induced activation of membrane-bound G proteins in the absence of protein receptors and that bilayer physical properties modulate this response. C1 Univ Calif San Diego, Dept Bioengn, La Jolla, CA 92093 USA. Los Alamos Natl Lab, Div Life Sci, Los Alamos, NM 87545 USA. RP Univ Calif San Diego, Dept Bioengn, La Jolla, CA 92093 USA. EM frangos@ucsd.edu FU NHLBI NIH HHS [R01 HL040696, R37 HL040696, HL-40696] NR 35 TC 211 Z9 219 U1 1 U2 8 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 MAR 3 PY 1998 VL 95 IS 5 BP 2515 EP 2519 DI 10.1073/pnas.95.5.2515 PG 5 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA ZA471 UT WOS:000072366600103 PM 9482917 ER PT J AU Schneibel, JH Liu, CT Heatherly, L Kramer, MJ AF Schneibel, JH Liu, CT Heatherly, L Kramer, MJ TI Assessment of processing routes and strength of a 3-phase molybdenum boron silicide (Mo5Si3-Mo5SiB2-Mo3Si) SO SCRIPTA MATERIALIA LA English DT Article C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. Iowa State Univ, Ames Lab, Ames, IA 50011 USA. RP Schneibel, JH (reprint author), Oak Ridge Natl Lab, POB 2008, Oak Ridge, TN 37831 USA. OI Liu, Chain Tsuan/0000-0001-7888-9725 NR 7 TC 41 Z9 44 U1 0 U2 5 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 1359-6462 J9 SCRIPTA MATER JI Scr. Mater. PD MAR 3 PY 1998 VL 38 IS 7 BP 1169 EP 1176 DI 10.1016/S1359-6462(97)00558-7 PG 8 WC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Science & Technology - Other Topics; Materials Science; Metallurgy & Metallurgical Engineering GA ZC736 UT WOS:000072611400022 ER PT J AU Engler, O AF Engler, O TI On the influence of orientation pinning on growth selection of recrystallisation SO ACTA MATERIALIA LA English DT Article ID RECRYSTALLIZATION TEXTURES; CUBE TEXTURE; DEFORMED ALUMINUM; COPPER; ORIGIN; DEPENDENCE; NUCLEATION; PARTICLES; NUCLEI AB With the help of techniques for local orientation determination it has been proved that the recrystallisation textures of Al-alloys evolve by a preferred formation of some orientations at characteristic nucleation sites and a subsequent growth select;on of distinct orientations out of this spectrum of nucleus orientations. As an alternative to the standard explanation of a favoured growth of grains with a special orientation relationship to the deformed matrix (e.g. 40 degrees [111]), recently the concept of "orientation pinning" has been proposed, which considers that the growth selection is determined by special orientation relationships being disfavoured (low-angle and twin grain boundaries). The present paper reviews the two rivalling theories of oriented nucleation and oriented growth to explain recrystallisation textures and addresses the new approach of orientation pinning. New EBSD-results on commercial purity Al which substantiate a growth selection of the exact cube-orientation out of the nucleus spectrum available in the cube-bands and the R-orientation out of the nucleus spectrum of the grain boundaries are presented. A semi-quantitative model to simulate the effect of orientation pinning on the evolution of recrystallisation textures is introduced. The results are discussed in view of growth selection and the 40 degrees [111] orientation relationship. (C) 1998 Acta Metallurgica Inc. C1 Univ Calif Los Alamos Natl Lab, Ctr Mat Sci, Los Alamos, NM 87545 USA. RP Engler, O (reprint author), Univ Calif Los Alamos Natl Lab, Ctr Mat Sci, K765, Los Alamos, NM 87545 USA. NR 51 TC 45 Z9 53 U1 6 U2 14 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 1359-6454 J9 ACTA MATER JI Acta Mater. PD MAR 2 PY 1998 VL 46 IS 5 BP 1555 EP 1568 DI 10.1016/S1359-6454(97)00354-6 PG 14 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA ZC925 UT WOS:000072632800009 ER PT J AU Moberlychan, WJ Cao, JJ De Jonghe, LC AF Moberlychan, WJ Cao, JJ De Jonghe, LC TI The roles of amorphous grain boundaries and the beta-alpha transformation in toughening SiC SO ACTA MATERIALIA LA English DT Article ID INTERGRANULAR FILM THICKNESS; B-C ADDITIONS; SILICON-CARBIDE; MECHANICAL-PROPERTIES; FRACTURE-TOUGHNESS; AL2O3 ADDITIONS; CURVE BEHAVIOR; STRENGTH; MICROSTRUCTURE; COMPOSITES AB Controlled development of the ceramic microstructure has produced silicon carbide (SiC) with a toughness three times that of a commercial SiC, Hexoloy-SA, coupled with >50% improvement in strength. Al, B and C were used as sintering additives, hence the designation ABC-SIC. These additives facilitated full densification at temperature as low as 1700 degrees C, the formation of an amorphous phase at the grain boundaries to enhance intergranular fracture, and the promotion of an elongated microstructure to enhance crack deflection and crack bridging. Comparisons of microstructure and fracture properties have been made between the present ABC-SiC, Hexoloy-SA and other reported SiC ceramics sintered with YAG or Al2O3. The Al-O chemistry of the amorphous phase in the ABC-SiC accounted for the intergranular fracture vs the transgranular fracture in Hexoloy-SA. An interlocking, plate-like grain structure developed during the beta to alpha transformation without limiting densification. The combined microstructural developments improved both strength and toughness. (C) 1998 Acta Metallurgica Inc. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Ctr Adv Mat, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Mat Sci & Mineral Engn, Berkeley, CA 94720 USA. RP Moberlychan, WJ (reprint author), Komag Inc, San Jose, CA 95131 USA. NR 43 TC 31 Z9 32 U1 2 U2 6 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 1359-6454 J9 ACTA MATER JI Acta Mater. PD MAR 2 PY 1998 VL 46 IS 5 BP 1625 EP 1635 DI 10.1016/S1359-6454(97)00343-1 PG 11 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA ZC925 UT WOS:000072632800015 ER PT J AU Chu, F Thoma, DJ Kotula, PG Gerstl, S Mitchell, TE Anderson, IM Bentley, J AF Chu, F Thoma, DJ Kotula, PG Gerstl, S Mitchell, TE Anderson, IM Bentley, J TI Phase stability and defect structure of the C15 Laves phase Nb(Cr,V)(2) SO ACTA MATERIALIA LA English DT Article ID MECHANICAL-PROPERTIES; DEFORMATION; ELEMENTS; ALLOYS; SYSTEM; CR2NB AB Vanadium alloyed C15 Laves phase based on NbCr2 and phase equilibria in the Nb-Cr-V system have been studied, focusing on the physical metallurgy and defect structures of the C15 phase. Based on the Nb-Cr-V phase diagram established in this work, the defect structure/mechanism in the ternary C15 Laves phase is investigated using a combination of metallography, SEM/EDS, TEM/ALCHEMI, and X-ray powder diffraction. It is found that the C15 phase field of NbCr2 is extended by V alloying up to more than 30 at.% V and V substitutes exclusively on the Cr site instead of the Nb site, although the atomic sizes of the constituent elements indicate r(Cr) pp pi(0) near threshold SO NUCLEAR PHYSICS A LA English DT Article; Proceedings Paper CT XVth International Conference on Few-Body Problems in Physics (Few-Body XV) CY JUL 22-26, 1997 CL GRONINGEN, NETHERLANDS SP City Groningen, Fdn Fundamental Onderzoek Mat, Fdn Groninger Univ Fonds, Fdn Phys, Inst Theoret Phys, Int Union Pure & Appl Phys, Koninklijke Nederlandse Acad Wetenschappen, Kernfys Versneller Inst, Nederlands Inst Kernen Hoge Energie Fys, Province Groningen, Rijksuniv Groningen, Vrije Univ Amsterdam, DANFYSIK, DIGITAL, LECROY, PQR ID NEAR-THRESHOLD; CROSS-SECTION; EXCHANGE C1 Jefferson Lab, Newport News, VA USA. Inst Nucl Phys, Prague, Czech Republic. CFNUL, Lisbon, Portugal. Univ Tecn Lisboa, Lisbon, Portugal. Coll William & Mary, Williamsburg, VA USA. RP Jefferson Lab, Newport News, VA USA. EM stadler@alf1.cii.fc.ul.pt; teresa@alf1.cii.fc.ul.pt; Franz@asci.wm.edu RI Stadler, Alfred/C-5550-2009; Adam, Jiri/G-9785-2014; Pena, Teresa/M-4683-2013 OI Stadler, Alfred/0000-0002-9596-0770; Pena, Teresa/0000-0002-3529-2408 NR 7 TC 2 Z9 2 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0375-9474 EI 1873-1554 J9 NUCL PHYS A JI Nucl. Phys. A PD MAR 2 PY 1998 VL 631 BP 570C EP 573C PG 4 WC Physics, Nuclear SC Physics GA ZH171 UT WOS:000073079900060 ER PT J AU van Leeuwe, JJ Blok, HP van den Brand, JFJ Bulten, HJ Dodge, GE Ent, R Hesselink, WHA Jans, E Kasdorp, WJ Laget, JM Lapikas, L Onderwater, CJG Pellegrino, AR Spaltro, CM Steijger, JJM Templon, JA Unal, O AF van Leeuwe, JJ Blok, HP van den Brand, JFJ Bulten, HJ Dodge, GE Ent, R Hesselink, WHA Jans, E Kasdorp, WJ Laget, JM Lapikas, L Onderwater, CJG Pellegrino, AR Spaltro, CM Steijger, JJM Templon, JA Unal, O TI The He-4(e,e ' p) cross section at large missing energy SO NUCLEAR PHYSICS A LA English DT Article; Proceedings Paper CT XVth International Conference on Few-Body Problems in Physics (Few-Body XV) CY JUL 22-26, 1997 CL GRONINGEN, NETHERLANDS SP City Groningen, Fdn Fundamental Onderzoek Mat, Fdn Groninger Univ Fonds, Fdn Phys, Inst Theoret Phys, Int Union Pure & Appl Phys, Koninklijke Nederlandse Acad Wetenschappen, Kernfys Versneller Inst, Nederlands Inst Kernen Hoge Energie Fys, Province Groningen, Rijksuniv Groningen, Vrije Univ Amsterdam, DANFYSIK, DIGITAL, LECROY, PQR ID NUCLEON AB The (e,e'p) reaction on He-4 nuclei was studied in kinematics designed to emphasize effects of nuclear short-range correlations. The measured cross sections display a peak in the kinematical regions where two-nucleon processes are expected to dominate. Theoretical models incorporating short-range correlation effects agree reasonably with the data. C1 NIKHEF, NL-1009 DB Amsterdam, Netherlands. Vrije Univ Amsterdam, Dept Phys & Astron, NL-1081 HV Amsterdam, Netherlands. Univ Wisconsin, Dept Phys, Madison, WI 53706 USA. Jefferson Lab, Newport News, VA 23606 USA. Ctr Etud Saclay, Serv Phys Nucl, F-91191 Gif Sur Yvette, France. Old Dominion Univ, Dept Phys, Norfolk, VA 23529 USA. Univ Georgia, Dept Phys & Astron, Athens, GA 30602 USA. RP van Leeuwe, JJ (reprint author), NIKHEF, POB 41882, NL-1009 DB Amsterdam, Netherlands. NR 10 TC 4 Z9 4 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0375-9474 J9 NUCL PHYS A JI Nucl. Phys. A PD MAR 2 PY 1998 VL 631 BP 593C EP 596C PG 4 WC Physics, Nuclear SC Physics GA ZH171 UT WOS:000073079900064 ER PT J AU Huber, D Witala, H Kamada, H Nogga, A Glockle, W AF Huber, D Witala, H Kamada, H Nogga, A Glockle, W TI Recent progress in the 3N system including three-nucleon forces SO NUCLEAR PHYSICS A LA English DT Article; Proceedings Paper CT XVth International Conference on Few-Body Problems in Physics (Few-Body XV) CY JUL 22-26, 1997 CL GRONINGEN, NETHERLANDS SP City Groningen, Fdn Fundamental Onderzoek Mat, Fdn Groninger Univ Fonds, Fdn Phys, Inst Theoret Phys, Int Union Pure & Appl Phys, Koninklijke Nederlandse Acad Wetenschappen, Kernfys Versneller Inst, Nederlands Inst Kernen Hoge Energie Fys, Province Groningen, Rijksuniv Groningen, Vrije Univ Amsterdam, DANFYSIK, DIGITAL, LECROY, PQR ID 3-NUCLEON C1 Univ Calif Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. Jagiellonian Univ, Inst Phys, PL-30059 Krakow, Poland. Ruhr Univ Bochum, Inst Theoret Phys 2, D-44780 Bochum, Germany. RP Huber, D (reprint author), Univ Calif Los Alamos Natl Lab, Div Theoret, MS B283, Los Alamos, NM 87545 USA. EM hueber@t5.lanl.gov; witala@nzfi.if.uj.edu.pl; kamada@tp2lin48.tp2.ruhr-uni-bochum.de; andreas.nogga@ruhr-uni-bochum.de RI Nogga, Andreas/A-3354-2008 OI Nogga, Andreas/0000-0003-2156-748X NR 10 TC 4 Z9 4 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0375-9474 J9 NUCL PHYS A JI Nucl. Phys. A PD MAR 2 PY 1998 VL 631 BP 663C EP 667C PG 5 WC Physics, Nuclear SC Physics GA ZH171 UT WOS:000073079900078 ER PT J AU Carr, SB Afnan, IR Gibson, BF AF Carr, SB Afnan, IR Gibson, BF TI The Lambda Lambda interaction and the reaction Xi(-)+d -> n+Lambda+Lambda SO NUCLEAR PHYSICS A LA English DT Article; Proceedings Paper CT XVth International Conference on Few-Body Problems in Physics (Few-Body XV) CY JUL 22-26, 1997 CL GRONINGEN, NETHERLANDS SP City Groningen, Fdn Fundamental Onderzoek Mat, Fdn Groninger Univ Fonds, Fdn Phys, Inst Theoret Phys, Int Union Pure & Appl Phys, Koninklijke Nederlandse Acad Wetenschappen, Kernfys Versneller Inst, Nederlands Inst Kernen Hoge Energie Fys, Province Groningen, Rijksuniv Groningen, Vrije Univ Amsterdam, DANFYSIK, DIGITAL, LECROY, PQR C1 Flinders Univ S Australia, Adelaide, SA 5001, Australia. Univ Calif Los Alamos Natl Lab, Los Alamos, NM USA. RP Carr, SB (reprint author), Flinders Univ S Australia, Adelaide, SA 5001, Australia. 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 0375-9474 J9 NUCL PHYS A JI Nucl. Phys. A PD MAR 2 PY 1998 VL 631 BP 776C EP 780C PG 5 WC Physics, Nuclear SC Physics GA ZH171 UT WOS:000073079900099 ER PT J AU Csoto, A Hale, GM AF Csoto, A Hale, GM TI S-matrix studies of resonances in A = 3, 4, 5, 6, and 12 nucleon systems SO NUCLEAR PHYSICS A LA English DT Article; Proceedings Paper CT XVth International Conference on Few-Body Problems in Physics (Few-Body XV) CY JUL 22-26, 1997 CL GRONINGEN, NETHERLANDS SP City Groningen, Fdn Fundamental Onderzoek Mat, Fdn Groninger Univ Fonds, Fdn Phys, Inst Theoret Phys, Int Union Pure & Appl Phys, Koninklijke Nederlandse Acad Wetenschappen, Kernfys Versneller Inst, Nederlands Inst Kernen Hoge Energie Fys, Province Groningen, Rijksuniv Groningen, Vrije Univ Amsterdam, DANFYSIK, DIGITAL, LECROY, PQR ID NEUTRON-HALO; 3-BODY RESONANCES; MICROSCOPIC MODEL; HE-6; STATES AB Resonances of certain light nuclei are explored by studying the complex pole structures of the scattering matrices. Among other results we predict the existence of three-neutron and three-proton resonances, a small spin-orbit splitting in the low-lying He-5 and Li-5 states, and the nonexistence of the soft dipole resonance in He-6. C1 Univ Calif Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. RP Csoto, A (reprint author), Univ Calif Los Alamos Natl Lab, Div Theoret, POB 1663, Los Alamos, NM 87545 USA. EM csoto@qmc.lanl.gov NR 19 TC 6 Z9 6 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0375-9474 J9 NUCL PHYS A JI Nucl. Phys. A PD MAR 2 PY 1998 VL 631 BP 783C EP 787C PG 5 WC Physics, Nuclear SC Physics GA ZH171 UT WOS:000073079900100 ER PT J AU Bern, Z Dixon, L Kosower, DA AF Bern, Z Dixon, L Kosower, DA TI One-loop amplitudes for e(+)e(-) to four partons SO NUCLEAR PHYSICS B LA English DT Review DE next-to-leading order corrections; multi-jet production ID JET CROSS-SECTIONS; BACKGROUND FIELD METHOD; MULTI-GLUON SCATTERING; E+E-ANNIHILATION; HELICITY AMPLITUDES; GAUGE-THEORIES; LIGHT GLUINOS; DIMENSIONAL REGULARIZATION; ALPHA-S; HADRON-COLLISIONS AB We present the first explicit formulae for the complete set of one-loop helicity amplitudes necessary for computing next-to-leading order corrections for e(+)e(-) annihilation into four jets, for W, Z or Drell-Yan production in association with two jets at hadron colliders, and for three-jet production in deeply inelastic scattering experiments. We include a simpler form of the previously published amplitudes for e(+)e(-) to four quarks. We obtain the amplitudes using their analytic properties to constrain their form. Systematically eliminating spurious poles from the amplitudes leads to relatively compact results. (C) 1998 Elsevier Science B.V. C1 Univ Calif Los Angeles, Dept Phys, Los Angeles, CA 90024 USA. Stanford Univ, Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. CENS, Serv Phys Theor, CEA, Lab Direct Sci Mat, F-91191 Gif Sur Yvette, France. RP Bern, Z (reprint author), Univ Calif Los Angeles, Dept Phys, Los Angeles, CA 90024 USA. EM bern@physics.ucla.edu; lance@slac.stanford.edu; kosower@spht.saclay.cea.fr NR 111 TC 288 Z9 288 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0550-3213 EI 1873-1562 J9 NUCL PHYS B JI Nucl. Phys. B PD MAR 2 PY 1998 VL 513 IS 1-2 BP 3 EP 86 DI 10.1016/S0550-3213(97)00703-7 PG 84 WC Physics, Particles & Fields SC Physics GA ZE686 UT WOS:000072820000001 ER PT J AU Hanany, A Hori, K AF Hanany, A Hori, K TI Branes and N=2 theories in two dimensions SO NUCLEAR PHYSICS B LA English DT Article DE supersymmetric gauge theories in two dimensions; M-theory; membrane; fivebrane; BPS solitons; level-rank duality ID SUPERSYMMETRIC CPN-1 MODEL; CHIRAL-SYMMETRY BREAKING; FIELD-THEORY; DUALITY; SCATTERING; STRINGS AB Type IIA brane configurations are used to construct N = 2 supersymmetric gauge theories in two dimensions, Using localization of chiral multiplets in ten-dimensional space-time, supersymmetric non-linear sigma models with target space such as CPn-1 and the Grassmann manifolds are studied in detail, The quantum properties of these models are realized in M-theory by taking the strong Type IIA coupling limit. The brane picture implies an equivalence between the parameter space of N = 2 supersymmetric theories in two dimensions and the moduli space of vacua of N = 2 supersymmetric gauge theories in four dimensions, Effects like level-rank duality are interpreted in the brane picture as continuation past infinite coupling. The BPS solitons of the CPn-1 model are identified as topological excitations of a membrane and their masses are computed. This provides the brane realization of higher rank tensor representations of the flavor group. (C) 1998 Elsevier Science B.V. C1 Inst Adv Study, Sch Nat Sci, Princeton, NJ 08540 USA. Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Phys, Berkeley, CA 94720 USA. RP Hanany, A (reprint author), Inst Adv Study, Sch Nat Sci, Olden Lane, Princeton, NJ 08540 USA. NR 70 TC 110 Z9 110 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0550-3213 J9 NUCL PHYS B JI Nucl. Phys. B PD MAR 2 PY 1998 VL 513 IS 1-2 BP 119 EP 174 DI 10.1016/S0550-3213(97)00754-2 PG 56 WC Physics, Particles & Fields SC Physics GA ZE686 UT WOS:000072820000003 ER PT J AU Davids, CN Woods, PJ Seweryniak, D Sonzogni, AA Batchelder, JC Bingham, CR Davinson, T Henderson, DJ Irvine, RJ Poli, GL Uusitalo, J Walters, WB AF Davids, CN Woods, PJ Seweryniak, D Sonzogni, AA Batchelder, JC Bingham, CR Davinson, T Henderson, DJ Irvine, RJ Poli, GL Uusitalo, J Walters, WB TI Proton radioactivity from highly deformed nuclei SO PHYSICAL REVIEW LETTERS LA English DT Article ID DECAY AB Proton radioactivity from Ho-141 and Eu-131 has been identified. The Ho-141 proton transition has an energy E-p = 1169(8) keV, a half-life t(1/2) = 4.2(4) ms, and is assigned to the decay of the 7/2(-)[523] Nilsson state. The Eu-131 transition has an energy E-p = 950(8) keV and a half-life of 26(6) ms, consistent with decay from either the 3/2(+)[411] or 5/2(+)[413] Nilsson orbital. The proton decay rates deviate significantly from calculations assuming spherical configurations, and thus indicate the onset of large deformations in the region of the proton drip line below Z = 69. C1 Argonne Natl Lab, Div Phys, Argonne, IL 60439 USA. Univ Edinburgh, Edinburgh EH9 3JZ, Midlothian, Scotland. Univ Maryland, Dept Chem, College Pk, MD 20742 USA. Oak Ridge Associated Univ, UNIRIB, Oak Ridge, TN 37831 USA. Univ Tennessee, Dept Phys & Astron, Knoxville, TN 37996 USA. Univ Milan, Ist Fis Gen Applicata, I-20133 Milan, Italy. RP Davids, CN (reprint author), Argonne Natl Lab, Div Phys, Argonne, IL 60439 USA. NR 20 TC 153 Z9 158 U1 2 U2 4 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD MAR 2 PY 1998 VL 80 IS 9 BP 1849 EP 1852 DI 10.1103/PhysRevLett.80.1849 PG 4 WC Physics, Multidisciplinary SC Physics GA YZ785 UT WOS:000072291400015 ER PT J AU Baldis, HA Labaune, C Moody, JD Jalinaud, T Tikhonchuk, VT AF Baldis, HA Labaune, C Moody, JD Jalinaud, T Tikhonchuk, VT TI Localization of stimulated Brillouin scattering in random phase plate speckles SO PHYSICAL REVIEW LETTERS LA English DT Article ID LASER HOT-SPOTS; PLASMA AB This paper presents the first experimental evidence of the transverse localization of stimulated Brillouin scattering (SBS) emission to the laser beam axis, demonstrating that only a few small regions of plasma contribute to the emission. As a consequence, SBS reflectivity of these regions is much higher than the average SBS reflectivity, by a factor of similar to 50-100. These observations are consistent with the recent concept of SBS growing mainly in "active" speckles, having an intensity higher than the average laser intensity. C1 Ecole Polytech, CNRS, Lab Utilisat Lasers Intenses, F-91128 Palaiseau, France. Univ Calif Lawrence Livermore Natl Lab, Inst Laser Sci & Applicat, Livermore, CA 94550 USA. Ecole Polytech, CNRS, Ctr Phys Theor, F-91128 Palaiseau, France. Russian Acad Sci, PN Lebedev Phys Inst, Moscow 117924, Russia. RP Baldis, HA (reprint author), Ecole Polytech, CNRS, Lab Utilisat Lasers Intenses, F-91128 Palaiseau, France. NR 12 TC 23 Z9 24 U1 1 U2 8 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD MAR 2 PY 1998 VL 80 IS 9 BP 1900 EP 1903 DI 10.1103/PhysRevLett.80.1900 PG 4 WC Physics, Multidisciplinary SC Physics GA YZ785 UT WOS:000072291400028 ER PT J AU Glendinning, SG Dixit, SN Hammel, BA Kalantar, DH Key, MH Kilkenny, JD Knauer, JP Pennington, DM Remington, BA Rothenberg, J Wallace, RJ Weber, SV AF Glendinning, SG Dixit, SN Hammel, BA Kalantar, DH Key, MH Kilkenny, JD Knauer, JP Pennington, DM Remington, BA Rothenberg, J Wallace, RJ Weber, SV TI Comparison of drive-seeded modulations in planar foils for 0.35 and 0.53 mu m laser drive SO PHYSICAL REVIEW LETTERS LA English DT Article ID RAYLEIGH-TAYLOR INSTABILITY; ABLATION; GROWTH AB Laser-speckle-seeded modulations in laser-driven targets have been observed with the Nova laser using 0.53 and 0.35 mu m drive. The 0.35 mu m drive produced larger modulations (equivalent to 3.3 mu m rms surface finish) than 0.53 mu m drive (2.0 mu m rms). The laser intensity was similar to 10(13) W/cm(2), similar to that suggested for directly driven ignition targets during the first several ns. LASNEX simulations of this thermal smoothing effect in both the rms and spectrum agree with the 0.53 mu m drive data, and are about 15% lower than the measured results with 0.35 mu m drive. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. Univ Rochester, Laser Energet Lab, Rochester, NY 14623 USA. RP Glendinning, SG (reprint author), Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. NR 16 TC 11 Z9 11 U1 0 U2 1 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD MAR 2 PY 1998 VL 80 IS 9 BP 1904 EP 1907 DI 10.1103/PhysRevLett.80.1904 PG 4 WC Physics, Multidisciplinary SC Physics GA YZ785 UT WOS:000072291400029 ER PT J AU Movshovich, R Hubbard, MA Salamon, MB Balatsky, AV Yoshizaki, R Sarrao, JL Jaime, M AF Movshovich, R Hubbard, MA Salamon, MB Balatsky, AV Yoshizaki, R Sarrao, JL Jaime, M TI Low-temperature anomaly in thermal conductivity of Bi2Sr2Ca(Cu1-xNix)(2)O-8: Second superconducting phase? SO PHYSICAL REVIEW LETTERS LA English DT Article ID NMR; NQR; NI AB We report the discovery of a low-temperature anomaly in thermal conductivity of Bi2Sr2Ca(Cu1-xNix)(2)O-8 high-temperature superconductor. This anomaly manifests itself as a sharp reduction of the thermal conductivity of the samples at a temperature T-c* approximate to 200 mK. The temperature dependence of the thermal conductivity changes dramatically from T-alpha with alpha between 1.6 and 1.75 above T-c* to T-Iinear behavior below it. Application of a small magnetic field suppresses the low-temperature anomaly. We propose that such behavior is consistent with a phase transition into a second bulk low-temperature superconducting state at T-c*. The presence of a second superconducting state would constitute direct evidence for unconventional superconductivity in Bi2Sr2CaCu2O8. Within the suggested scenario, time-reversal symmetry is likely to he violated in the low-temperature phase. [S0031-9007(98)05422-2]. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Univ Illinois, Urbana, IL 61801 USA. Univ Tsukuba, Inst Appl Phys, Cryogen Ctr, Tsukuba, Ibaraki 305, Japan. RP Movshovich, R (reprint author), Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RI Jaime, Marcelo/F-3791-2015 OI Jaime, Marcelo/0000-0001-5360-5220 NR 32 TC 63 Z9 63 U1 1 U2 3 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD MAR 2 PY 1998 VL 80 IS 9 BP 1968 EP 1971 DI 10.1103/PhysRevLett.80.1968 PG 4 WC Physics, Multidisciplinary SC Physics GA YZ785 UT WOS:000072291400045 ER PT J AU Balatsky, AV AF Balatsky, AV TI Spontaneous time reversal and parity breaking in a d(x(2)-y(2))-wave superconductor with magnetic impurities SO PHYSICAL REVIEW LETTERS LA English DT Article ID D-WAVE SUPERCONDUCTOR; VORTEX; PLANES; HEAT AB It is shown that patches of complex d(xy), components are generated around a magnetic impurity in the presence of coupling between the orbital moment of the condensate and the impurity spin S-z. The locally induced d(xy) gap leads to the fully gapped quasiparticle spectrum near impurity. It is suggested that at low temperatures the well de tined patches of d(xy) are formed, possibly leading to a phase locked state due ttl Josephson tunneling. Violation of time-reversal symmetry and parity occurs spontaneously at this point via a second order transition. In the ordered phase both the impurity magnetization and the d(xy) component of the order parameter develop and are proportional to each other. [S0031-9007(98)05427-1]. C1 Univ Calif Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. RP Balatsky, AV (reprint author), Univ Calif Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. NR 31 TC 78 Z9 78 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 MAR 2 PY 1998 VL 80 IS 9 BP 1972 EP 1975 DI 10.1103/PhysRevLett.80.1972 PG 4 WC Physics, Multidisciplinary SC Physics GA YZ785 UT WOS:000072291400046 ER PT J AU Wehner, MU Ulm, MH Chemla, DS Wegener, M AF Wehner, MU Ulm, MH Chemla, DS Wegener, M TI Coherent control of electron-LO-phonon scattering in bulk GaAs SO PHYSICAL REVIEW LETTERS LA English DT Article ID QUANTUM KINETICS; SEMICONDUCTORS; SPECTROSCOPY AB Several tens of femtoseconds after optical excitation, scattering processes in semiconductors are not completed, thus, relaxation has not yet become irreversible. This opens the fascinating possibility of actually reversing or enhancing incompleted scattering events. Here, we use attosecond time scale coherent control to suppress or amplify the non-Markovian phonon oscillations in the model semiconductor GaAs. [S0031-9007(98)05370-8]. C1 Univ Karlsruhe, Inst Angew Phys, D-76128 Karlsruhe, Germany. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. RP Wehner, MU (reprint author), Univ Karlsruhe, Inst Angew Phys, Kaiserstr 12, D-76128 Karlsruhe, Germany. RI Wegener, Martin/S-5456-2016 NR 20 TC 143 Z9 144 U1 0 U2 9 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD MAR 2 PY 1998 VL 80 IS 9 BP 1992 EP 1995 DI 10.1103/PhysRevLett.80.1992 PG 4 WC Physics, Multidisciplinary SC Physics GA YZ785 UT WOS:000072291400051 ER PT J AU Jiang, H Klemmer, TJ Barnard, JA Doyle, WD Payzant, EA AF Jiang, H Klemmer, TJ Barnard, JA Doyle, WD Payzant, EA TI Epitaxial growth of Cu(111) films on Si(110) by magnetron sputtering: orientation and twin growth SO THIN SOLID FILMS LA English DT Letter DE epitaxial growth; Cu(111) films; magnetron sputtering ID SURFACE-MORPHOLOGY; METALLIZATION; SI AB Cu epitaxial films were grown on H-terminated Si(110) and Si(111) substrates by magnetron sputtering. The epitaxial orientation of the Cu films and microstructural characteristics were studied by X-ray diffraction, including the conventional theta-2 theta mode and pole figures, and transmission electron microscopy (TEM). The results of pole figure analysis show an epitaxial orientation relationship of Cu(111)//Si(110) with Cu[(1) over bar 10]//Si[001] and Cu[1 (1) over bar 0]//Si[001] which are twin-related. The TEM observations of the cross-sectional samples reveal that the Cu film contains a layered structure due to growth twins. The reason for twin formation is discussed. (C) 1998 Elsevier Science S.A. C1 Univ Alabama, Ctr Mat Informat Technol, Tuscaloosa, AL 35487 USA. Oak Ridge Natl Lab, High Temp Mat Lab, Oak Ridge, TN 37831 USA. RP Jiang, H (reprint author), Univ Alabama, Ctr Mat Informat Technol, Box 870209, Tuscaloosa, AL 35487 USA. RI Payzant, Edward/B-5449-2009 OI Payzant, Edward/0000-0002-3447-2060 NR 13 TC 28 Z9 28 U1 2 U2 13 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 MAR 2 PY 1998 VL 315 IS 1-2 BP 13 EP 16 DI 10.1016/S0040-6090(97)00954-1 PG 4 WC Materials Science, Multidisciplinary; Materials Science, Coatings & Films; Physics, Applied; Physics, Condensed Matter SC Materials Science; Physics GA ZV073 UT WOS:000074265800004 ER PT J AU Nilson, RH Griffiths, SK AF Nilson, RH Griffiths, SK TI Scaling wafer stresses and thermal processes to large wafers SO THIN SOLID FILMS LA English DT Article DE wafer stresses; ramp rates; wafer spacing ID SEMICONDUCTOR WAFERS AB Gravitational stresses limit maximum temperatures for processing semiconductor wafers. Allowable rates of heating and cooling are also limited by the combined affects of thermal and gravitational stresses, particularly in batch processing of stacked wafers. With increasing wafer diameter these limitations become more severe, requiring such measures as improved wafer support to maintain a desired processing temperature or increased wafer spacing to maintain desired rates of heating and cooling. These issues are addressed here through the derivation of scaling rules and engineering formulas relating allowable operating conditions to wafer dimensions. Gravitational stresses and displacements are first determined analytically for wafers supported by rings or at discrete points. The maximum operating temperature is then computed by comparing the calculated gravitational stresses with the temperature-dependent wafer strength. The difference between wafer strength and gravitational stress is used to determine the allowable thermal stress and allowable temperature variation across the wafer. Finally, an analytical model of radial heat transfer in a batch furnace is used to compute the maximum permissible rates of heating and cooling as a function of the instantaneous wafer temperature. Example calculations illustrate the dependence of maximum operating temperatures and allowable ramp rates on wafer dimensions, support geometry, and wafer spacing. (C) 1998 Elsevier Science S.A. C1 Sandia Natl Labs, Livermore, CA 94550 USA. RP Nilson, RH (reprint author), Sandia Natl Labs, Livermore, CA 94550 USA. NR 10 TC 3 Z9 3 U1 0 U2 0 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0040-6090 J9 THIN SOLID FILMS JI Thin Solid Films PD MAR 2 PY 1998 VL 315 IS 1-2 BP 286 EP 293 DI 10.1016/S0040-6090(97)00794-3 PG 8 WC Materials Science, Multidisciplinary; Materials Science, Coatings & Films; Physics, Applied; Physics, Condensed Matter SC Materials Science; Physics GA ZV073 UT WOS:000074265800047 ER PT J AU Oostrom, M Lenhard, RJ AF Oostrom, M Lenhard, RJ TI Comparison of relative permeability-saturation-pressure parametric models for infiltration and redistribution of a light nonaqueous-phase liquid in sandy porous media SO ADVANCES IN WATER RESOURCES LA English DT Article DE constitutive relations; multiphase flow; numerical simulation; LNAPL ID GOVERNING MULTIPHASE FLOW; HYDRAULIC CONDUCTIVITY; FLUID-FLOW; VERIFICATION; SIMULATIONS; VALIDATION; SYSTEMS; SOILS AB To test and evaluate the ability of commonly used constitutive relations for multifluid flow predictions, results of numerical flow and transport simulations are compared to experimental data. Three quantitative experiments were conducted in l-m-long vertical columns. The columns were filled with either a uniform sand, a sand with a broad particle-size distribution, or with a layered system where a layer of a course-textured uniform sand was placed in an otherwise finer-textured uniform sand. After establishing variably water-saturated conditions, a pulse of a light nonaqueous-phase liquid (LNAPL) was injected uniformly at a constant rate. Water and LNAPL saturations were measured as a function of time and elevation with a dual-energy gamma-radiation system. The infiltration and redistribution of the LNAPL were simulated with nonhysteretic and hysteretic parametric relative permeability-saturation-pressure (k-S-P) models. The models were calibrated using two-phase air-water retention data and an established scaling theory. The nonhysteretic Brooks-Corey K-S-P model, which utilizes the Burdine relative permeability model, yielded predictions that closely matched the experimental data. Use of the nonhysteretic and hysteretic k-S-P models, based on the van Genuchten S-P relations and k-S relations derived from the Mualem relative permeability model, did not agree as well with the experimental data as those obtained with the Brooks-Corey k-S-P model. Explanations for the differences in performance of the three tested parametric k-S-P models are proposed. C1 Pacific NW Lab, Environm Technol Div, Richland, WA 99352 USA. Sultan Qaboos Univ, Al Khoud, Oman. RP Oostrom, M (reprint author), Pacific NW Lab, Environm Technol Div, POB 999, Richland, WA 99352 USA. NR 39 TC 53 Z9 56 U1 1 U2 7 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 MAR PY 1998 VL 21 IS 2 BP 145 EP 157 DI 10.1016/S0309-1708(96)00038-3 PG 13 WC Water Resources SC Water Resources GA YR844 UT WOS:000071536500004 ER PT J AU Carrie, FR Modera, MP AF Carrie, FR Modera, MP TI Particle deposition in a two-dimensional slot from a transverse stream SO AEROSOL SCIENCE AND TECHNOLOGY LA English DT Article AB This paper addresses the problem of coarse mode particle deposition in a tao-dimensional slot from a transverse how. A dimensional analysis enables us to identify five independent dimensionless groups: the leak Reynolds number, Re, the dimensionless velocity gradient of the approaching flow, alpha, the Stokes number, Stk, the slot aspect-ratio, e/h, and the interception parameter, d(p)/h. A sticky aerosol (MMD approximate to 3-7 mu m; GSD approximate to 2-3) was injected into a 15 cm diameter duct and blown out through a rectangular opening (3 x 40 mm; e = 0.6 mm) drilled in a direction perpendicular to the flow. A video camera was set up to continuously monitor the leak behavior in time. The image then was digitized, enabling us to assess the slot-width as a function of time. It appeared that the slot could be sealed in less than 20 minutes. These results were compared with a simplified model based on a scale analysis of the deposition velocity on the slot thickness. Agreement between predicted and measured leak-widths is very good when the pressure differential across the opening does not exceed 60 Pascals. Deposition on the upstream edge is observed only when its surface is not smooth. (C) 1998 American Association for Aerosol Research. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Environm Energy Technol Div, Berkeley, CA 94720 USA. Ecole Natl Travaux Publ Etat, Lab Sci Habitat, DGCB, CNRS,URA 1652, F-69518 Vaulx En Velin, France. RP Modera, MP (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Environm Energy Technol Div, Bldg 90,Room 3074, Berkeley, CA 94720 USA. OI Carrie, Francois Remi/0000-0002-5021-7166 NR 13 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 0278-6826 J9 AEROSOL SCI TECH JI Aerosol Sci. Technol. PD MAR PY 1998 VL 28 IS 3 BP 235 EP 246 DI 10.1080/02786829808965524 PG 12 WC Engineering, Chemical; Engineering, Mechanical; Environmental Sciences; Meteorology & Atmospheric Sciences SC Engineering; Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences GA ZA387 UT WOS:000072358400005 ER PT J AU Chialvo, AA Cummings, PT Kalyuzhnyi, YV AF Chialvo, AA Cummings, PT Kalyuzhnyi, YV TI Solvation effect on kinetic rate constant of reactions in supercritical solvents SO AICHE JOURNAL LA English DT Article ID NEAR-CRITICAL CONDITIONS; DILUTE MIXTURES; CARBON-DIOXIDE; FLUIDS; SOLUTE; THERMODYNAMICS; SIMULATION; LIQUID; STATE; WATER AB A statistical mechanical analysis of the solvation effects on the kinetic rate constants of reactions in near and supercritical solvents is presented to understand the experimental findings regarding the thermodynamic pressure effects. This is an extension of the solvation formalism of Chialvo and Cummings to the analysis of the microscopic basis for the macroscopic pressure and temperature effects on the kinetic rate constants of reactions conducted in the compressible region of the solvent phase diagram. This analysis is illustrated with integral equations calculations involving Lennard-Jones infinitely dilute quaternary systems to describe the species in solution during the reaction of triplet benzophenone ((3)BP) with a cosolvent (either O(2) or 1,4-cyclohexadiene) in supercritical CO(2) along the supercritical isotherms T(r) = 1.01 and 1.06. The role of the species molecular asymmetries and consequently their solvation behavior in determining the thermodynamic pressure and temperature effects on the kinetic rate constant of reactions at near-critical conditions are discussed. C1 Univ Tennessee, Dept Chem Engn, Knoxville, TN 37996 USA. Oak Ridge Natl Lab, Div Chem Technol, Oak Ridge, TN 37831 USA. Inst Condensed Matter Phys, UA-290011 Lvov, Ukraine. RP Chialvo, AA (reprint author), Univ Tennessee, Dept Chem Engn, Knoxville, TN 37996 USA. RI Cummings, Peter/B-8762-2013; OI Cummings, Peter/0000-0002-9766-2216; Chialvo, Ariel/0000-0002-6091-4563 NR 59 TC 31 Z9 32 U1 1 U2 5 PU WILEY-BLACKWELL PI MALDEN PA COMMERCE PLACE, 350 MAIN ST, MALDEN 02148, MA USA SN 0001-1541 J9 AICHE J JI AICHE J. PD MAR PY 1998 VL 44 IS 3 BP 667 EP 680 DI 10.1002/aic.690440315 PG 14 WC Engineering, Chemical SC Engineering GA ZA866 UT WOS:000072409900014 ER PT J AU Wise, GM Denn, MM Bell, AT AF Wise, GM Denn, MM Bell, AT TI Near-surface dynamics of sheared polymer melts using ATR/FTIR SO AICHE JOURNAL LA English DT Article ID SOLID INTERFACE; VISCOELASTIC PROPERTIES; SPINODAL DECOMPOSITION; DENSITY POLYETHYLENE; DESORPTION-KINETICS; MOLECULAR-WEIGHT; SELF-DIFFUSION; MONTE-CARLO; ADSORPTION; POLYBUTADIENE AB Using attenuated total-reflectance infrared spectroscopy (ATR/FTIR), the concentration of deuterated polybutadiene near the surface of a flat zinc selenide crystal was followed as it was replaced by ordinary polybutadiene by flow and diffusion. Experiments were performed in the melt, both below (M similar to 1,500) and above (M similar to 15,000) the entanglement threshold. The decay profiles agree well with a finite-element simulation of the system. In contrast to previous investigations of C-16's, the decay profiles of both unentangled and entangled polybutadienes are consistent with a uniform diffusivity in the near-wall region. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Dept Chem Engn, Berkeley, CA 94720 USA. RP Denn, MM (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. OI Bell, Alexis/0000-0002-5738-4645 NR 46 TC 12 Z9 13 U1 0 U2 4 PU AMER INST CHEMICAL ENGINEERS PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 0001-1541 J9 AICHE J JI AICHE J. PD MAR PY 1998 VL 44 IS 3 BP 701 EP 710 DI 10.1002/aic.690440318 PG 10 WC Engineering, Chemical SC Engineering GA ZA866 UT WOS:000072409900017 ER PT J AU Wu, DXY Lee, CYC Uyekubo, SN Choi, HK Bastacky, SJ Widdicombe, JH AF Wu, DXY Lee, CYC Uyekubo, SN Choi, HK Bastacky, SJ Widdicombe, JH TI Regulation of the depth of surface liquid in bovine trachea SO AMERICAN JOURNAL OF PHYSIOLOGY-LUNG CELLULAR AND MOLECULAR PHYSIOLOGY LA English DT Article DE low-temperature scanning electron microscopy; epithelial ion transport ID GUINEA-PIG TRACHEA; SUBMUCOSAL GLAND-CELLS; SUB-MUCOSAL GLANDS; FLUID TRANSPORT; EPITHELIUM; SECRETION; CHLORIDE; MUCUS AB The luminal surface of airways is lined by a thin film of airway surface liquid (ASL). Physiological regulation of the depth of ASL has not been reported previously. In this paper, we have used low-temperature scanning electron microscopy of rapidly frozen specimens of bovine tracheal epithelium to demonstrate alterations in the depth of ASL in response to the cholinergic agonist methacholine. We first established that methacholine selectively stimulated airway glands, with maximal secretion at similar to 2 min and a return to baseline within similar to 5 min. A 2-min exposure to methacholine increased the depth of ASL from 23 to 78 mu m. Thereafter, depth decreased linearly with time, reaching 32 mu m at 30 min. The initial increase in depth was blocked by bumetanide, an inhibitor of active chloride secretion, whereas the slow decline back to baseline was inhibited by amiloride, a blocker of active sodium absorption. We conclude that the methacholine-induced changes in ASL depth reflect transient gland secretion followed by liquid absorption across the surface epithelium. C1 Childrens Hosp, Oakland Res Inst, Oakland, CA 94609 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. Univ Calif San Francisco, Cardiovasc Res Inst, San Francisco, CA 94143 USA. RP Widdicombe, JH (reprint author), Childrens Hosp, Oakland Res Inst, 747 52nd St, Oakland, CA 94609 USA. FU NHLBI NIH HHS [HL-52161, HL-42368] NR 34 TC 35 Z9 36 U1 0 U2 1 PU AMER PHYSIOLOGICAL SOC PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814 USA SN 1040-0605 J9 AM J PHYSIOL-LUNG C JI Am. J. Physiol.-Lung Cell. Mol. Physiol. PD MAR PY 1998 VL 274 IS 3 BP L388 EP L395 PG 8 WC Physiology; Respiratory System SC Physiology; Respiratory System GA ZA925 UT WOS:000072415800011 PM 9530174 ER PT J AU Bartlett, EJ Brodie, JD Simkowitz, P Schlosser, R Dewey, SL Lindenmayer, JP Rusinek, H Wolkin, A Cancro, R Schiffer, W AF Bartlett, EJ Brodie, JD Simkowitz, P Schlosser, R Dewey, SL Lindenmayer, JP Rusinek, H Wolkin, A Cancro, R Schiffer, W TI Effect of a haloperidol challenge on regional brain metabolism in neuroleptic-responsive and nonresponsive schizophrenic patients SO AMERICAN JOURNAL OF PSYCHIATRY LA English DT Article ID POSITRON-EMISSION TOMOGRAPHY; D2-DOPAMINE RECEPTOR OCCUPANCY; CEREBRAL GLUCOSE-UTILIZATION; CLINICAL-RESPONSE; DOPAMINE RELEASE; TIME COURSE; HYPOTHESIS; PET; REGISTRATION; CIRCUITS AB Objective: The CNS metabolic response to a neuroleptic challenge in treatment-responsive and nonresponsive schizophrenic patients was measured in order to examine the relation between treatment outcome and the capacity to alter neurochemical function in response to acute receptor blockade. Method: Positron emission tomography (PET) and [F-18]fluorodeoxyglucose (FDG) were used to measure regional cerebral metabolism in seven schizophrenic patients judged to have been responsive to drug treatment previously and seven nonresponsive schizophrenic patients after a drug-free period of at least 3 weeks (baseline) and again 12 hours after administration of 5.0 mg of haloperidol. Results: The haloperidol challenge caused widespread decreases in absolute metabolism in the nonresponsive patients but not the responsive patients. These group differences reflect the findings on the second (challenge) scans, since metabolic values at baseline were not statistically different in the two groups. The pattern of decreased metabolic activity in the nonresponders after the haloperidol challenge is similar to that previously observed in normal subjects. Conclusions: The metabolic response to drug challenge separates treatment responders from nonresponders and normal subjects. The results suggest that subtyping of schizophrenia (and other psychiatric disorders) can be achieved by measuring the physiologic response to a pharmacologic challenge in vivo with chemical brain-imaging techniques. C1 NYU, Med Ctr, Dept Psychiat, New York, NY 10016 USA. NYU, Med Ctr, Dept Radiol, New York, NY 10016 USA. Brookhaven Natl Lab, Dept Chem, Upton, NY 11973 USA. RP Bartlett, EJ (reprint author), NYU, Med Ctr, Dept Psychiat, 550 1st Ave, New York, NY 10016 USA. RI Schlosser, Ralf/F-2822-2010 FU NCRR NIH HHS [RR-00096]; NIMH NIH HHS [MH-47277]; NINDS NIH HHS [NS-15638] NR 30 TC 37 Z9 37 U1 0 U2 0 PU AMER PSYCHIATRIC ASSOCIATION PI WASHINGTON PA 1400 K ST NW, WASHINGTON, DC 20005 USA SN 0002-953X J9 AM J PSYCHIAT JI Am. J. Psychiat. PD MAR PY 1998 VL 155 IS 3 BP 337 EP 343 PG 7 WC Psychiatry SC Psychiatry GA YZ777 UT WOS:000072290600004 PM 9501742 ER PT J AU Volkow, ND Gur, RC Wang, GJ Fowler, JS Moberg, PJ Ding, YS Hitzemann, R Smith, G Logan, J AF Volkow, ND Gur, RC Wang, GJ Fowler, JS Moberg, PJ Ding, YS Hitzemann, R Smith, G Logan, J TI Association between decline in brain dopamine activity with age and cognitive and motor impairment in healthy individuals SO AMERICAN JOURNAL OF PSYCHIATRY LA English DT Article; Proceedings Paper CT 33rd Annual Meeting of the American-College-of-Neuropsychopharmacology CY DEC 12-16, 1994 CL SAN JUAN, PUERTO RICO SP Amer Coll Neuropsychopharm ID CEREBRAL BLOOD-FLOW; C-11 RACLOPRIDE; D-2 RECEPTORS; PET; BINDING; SCHIZOPHRENIA; PARKINSONISM; ACTIVATION; DISEASE; SYSTEM AB Objective: Although it is documented that brain dopamine activity declines with age, the functional significance of this is not known. This study assessed the relation between measures of brain dopamine activity and indexes of motor and cognitive function in healthy individuals. Method: Thirty healthy volunteers aged 24-86 years were studied with positron emission tomography and [C-11]raclopride to assess dopamine D-2 receptors. All subjects underwent a neuropsychological test battery that included tasks found to be sensitive to dopamine alterations in patients with neurodegenerative disease and control tasks. Results: Transfer of[C-11]-raclopride from plasma to brain in the striatum and cerebellum was not affected by age. In contrast, D-2 receptor availability in the caudate and putamen declined with age. Correlations between D-2 receptors and neuropsychological test performance were strongest for the motor task (Finger Tapping Test) and were also significant for most tasks involving frontal brain regions, including measures of abstraction and mental flexibility (Winconsin Card Sorting Test) and attention and response inhibition (Stroop Color-Word Test, interference score). These relationships remained significant after control for age effects. Conclusions: Age-related decreases in brain dopamine activity are associated with a decline in motor function and may also contribute to impaired performance on tasks that involve frontal brain regions. Interventions that enhance dopamine activity may improve performance and quality of life for the elderly. The fact that correlations remained significant after age effects were partialed out suggests that dopamine activity may influence motor and cognitive performance irrespective of age. C1 Brookhaven Natl Lab, Dept Med, Upton, NY 11973 USA. Brookhaven Natl Lab, Dept Chem, Upton, NY 11973 USA. SUNY Stony Brook, Dept Psychiat, Stony Brook, NY 11794 USA. Univ Penn, Sch Med, Dept Psychiat, Brain Behav Lab, Philadelphia, PA 19104 USA. RP Volkow, ND (reprint author), Brookhaven Natl Lab, Dept Med, Upton, NY 11973 USA. FU NIDA NIH HHS [DA-06891] NR 46 TC 491 Z9 500 U1 7 U2 25 PU AMER PSYCHIATRIC ASSOCIATION PI WASHINGTON PA 1400 K ST NW, WASHINGTON, DC 20005 USA SN 0002-953X J9 AM J PSYCHIAT JI Am. J. Psychiat. PD MAR PY 1998 VL 155 IS 3 BP 344 EP 349 PG 6 WC Psychiatry SC Psychiatry GA YZ777 UT WOS:000072290600005 PM 9501743 ER PT J AU Northrup, MA Benett, B Hadley, D Landre, P Lehew, S Richards, J Stratton, P AF Northrup, MA Benett, B Hadley, D Landre, P Lehew, S Richards, J Stratton, P TI A miniature analytical instrument for nucleic acids based on micromachined silicon reaction chambers SO ANALYTICAL CHEMISTRY LA English DT Article ID CHEMICAL-ANALYSIS SYSTEMS; POLYMERASE CHAIN-REACTION; CAPILLARY ELECTROPHORESIS; DNA AMPLIFICATION; GLASS CHIPS; PCR AMPLIFICATION; SEPARATIONS; INTEGRATION; PRODUCT AB In this paper, we describe a miniature analytical thermal cycling instrument (MATCI) to amplify and detect DNA via the polymerase chain reaction in real-time. The MATCI is an integrated, miniaturized analytical system that uses silicon-based, high-efficiency reaction chambers with integrated heaters and simple, inexpensive electronics to precisely control the reaction temperatures. Optical windows in the silicon and solid-state, diode-based detection components are employed to perform real-time fluorescence monitoring of product DNA production. The entire system fits into a briefcase and runs on rechargeable batteries. The applications of this miniaturized nucleic acid analysis system include clinical, research, environmental, and agricultural analyses as well as others which require rapid, portable, and accurate analysis of biological samples for nucleic acids. This paper describes the MATCI and presents results from ultrafast thermal cycling and real-time PCR detection. Examples include human genes and pathogenic viruses and bacteria. C1 Cepheid, Sunnyvale, CA 94089 USA. Univ Calif Lawrence Livermore Natl Lab, Microtechnol Ctr, Livermore, CA 94551 USA. RP Northrup, MA (reprint author), Cepheid, 1190 Borregas Ave, Sunnyvale, CA 94089 USA. NR 37 TC 211 Z9 220 U1 2 U2 18 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 MAR 1 PY 1998 VL 70 IS 5 BP 918 EP 922 DI 10.1021/ac970486a PG 5 WC Chemistry, Analytical SC Chemistry GA ZB216 UT WOS:000072448400023 PM 9511467 ER PT J AU Egorov, O O'Hara, MJ Ruzicka, J Grate, JW AF Egorov, O O'Hara, MJ Ruzicka, J Grate, JW TI Sequential injection separation system with stopped-flow radiometric detection for automated analysis of Tc-99 in nuclear waste SO ANALYTICAL CHEMISTRY LA English DT Article ID PLASMA-MASS SPECTROMETRY; PRECONCENTRATION; URANIUM AB An automated procedure for the determination of Tc-99 in aged nuclear waste has been developed. Using advanced sequential injection (SI) analysis instrumentation, Tc-99(VII) is separated from radioactive and stable interferences using a TEVA resin column that selectively retains pertechnetate ion from dilute nitric acid solutions. The separated Tc-99 is eluted with 6 M nitric acid and quantified on-line with a now-through liquid scintillation detector. A stopped-flow technique has been optimized that improves the analysis precision and detection limit compared to continuous-flow detection, reduces consumption of liquid scintillation cocktail, and increases sample throughput by separating the next sample while the present sample is being counted. The detection limit is 30 pCi, or 2 ng, of Tc-99, using a 15-min stopped-now period. The analysis time is 40 min for the first sample and is reduced to 20 min for each subsequent sample. Processed nuclear waste samples from the Hanford site were successfully analyzed by this new method. C1 Pacific NW Lab, Environm Mol Sci Lab, Richland, WA 99352 USA. Univ Washington, Dept Chem, Seattle, WA 98195 USA. RP Grate, JW (reprint author), Pacific NW Lab, Environm Mol Sci Lab, POB 999, Richland, WA 99352 USA. RI O'Hara, Matthew/I-4967-2013; OI O'Hara, Matthew/0000-0003-3982-5897 NR 31 TC 39 Z9 40 U1 2 U2 8 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 MAR 1 PY 1998 VL 70 IS 5 BP 977 EP 984 DI 10.1021/ac971121t PG 8 WC Chemistry, Analytical SC Chemistry GA ZB216 UT WOS:000072448400033 PM 21644627 ER PT J AU Willardson, BM Wilkins, JF Rand, TA Schupp, JM Hill, KK Keim, P Jackson, PJ AF Willardson, BM Wilkins, JF Rand, TA Schupp, JM Hill, KK Keim, P Jackson, PJ TI Development and testing of a bacterial biosensor for toluene-based environmental contaminants SO APPLIED AND ENVIRONMENTAL MICROBIOLOGY LA English DT Article ID TRANSCRIPTION INITIATION SITE; UPSTREAM REGULATORY SEQUENCE; TOL PLASMID; PSEUDOMONAS-PUTIDA; NUCLEOTIDE-SEQUENCE; AROMATIC-HYDROCARBONS; XYLENE METABOLISM; UPPER PATHWAY; GENE-PRODUCT; XYLR AB A bacterial biosensor for benzene, toluene, and similar compounds has been constructed, characterized, and field tested on contaminated water and soil, The biosensor is based on a plasmid incorporating the transcriptional activator xylR from the TOL plasmid of Pseudomonas putida mt-2, The XylR protein binds a subset of toluene-like compounds and activates transcription at its promoter, P-u. A reporter plasmid was constructed by placing the luc gene for firefly luciferase under the control of XylR and P-u. When Escherichia coli cells were transformed with this plasmid vector, luminescence from the cells was induced in the presence of benzene, toluene, xylenes, and similar molecules, Accurate concentration dependencies of luminescence were obtained and exhibited K-1/2 values ranging from 39.0 +/- 3.8 mu M for 3-xylene to 2,690 +/- 160 mu M for 3-methylbenzylalcohol (means +/- standard deviations), The luminescence response was specific for only toluene-like molecules that bind to and activate XylR. The biosensor cells were field tested on deep aquifer water, for which contaminant levels were known, and were able to accurately detect toluene derivative contamination in this water, The biosensor cells were also shown to detect BETX (benzene, toluene, and xylene) contamination in soil samples, These results demonstrate the capability of such a bacterial biosensor to accurately measure environmental contaminants and suggest a potential for its inexpensive application in field-ready assays. C1 Brigham Young Univ, Dept Chem & Biochem, Provo, UT 84602 USA. Univ Calif Los Alamos Natl Lab, Div Life Sci, Environm Mol Biol Grp, Los Alamos, NM 87545 USA. No Arizona Univ, Dept Biol Sci, Flagstaff, AZ 86011 USA. RP Willardson, BM (reprint author), Brigham Young Univ, Dept Chem & Biochem, Provo, UT 84602 USA. EM barry_willardson@bpu.edu RI Keim, Paul/A-2269-2010; Wilkins, Jon/A-4984-2009 OI Wilkins, Jon/0000-0001-6405-6538 NR 30 TC 114 Z9 117 U1 1 U2 12 PU AMER SOC MICROBIOLOGY PI WASHINGTON PA 1325 MASSACHUSETTS AVENUE, NW, WASHINGTON, DC 20005-4171 USA SN 0099-2240 J9 APPL ENVIRON MICROB JI Appl. Environ. Microbiol. PD MAR PY 1998 VL 64 IS 3 BP 1006 EP 1012 PG 7 WC Biotechnology & Applied Microbiology; Microbiology SC Biotechnology & Applied Microbiology; Microbiology GA YZ798 UT WOS:000072292700029 PM 9501440 ER PT J AU Ladisch, MR Wright, L AF Ladisch, MR Wright, L TI Feedstock supply and processing SO APPLIED BIOCHEMISTRY AND BIOTECHNOLOGY LA English DT Editorial Material C1 Purdue Univ, Renewable Resources Engn Lab, W Lafayette, IN 47907 USA. Dept Agr & Biol Engn, W Lafayette, IN USA. Oak Ridge Natl Lab, Oak Ridge, TN USA. RP Ladisch, MR (reprint author), Purdue Univ, Renewable Resources Engn Lab, W Lafayette, IN 47907 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU HUMANA PRESS INC PI TOTOWA PA 999 RIVERVIEW DRIVE SUITE 208, TOTOWA, NJ 07512 USA SN 0273-2289 J9 APPL BIOCHEM BIOTECH JI Appl. Biochem. Biotechnol. PD SPR PY 1998 VL 70-2 BP 1 EP 2 DI 10.1007/BF02920118 PG 2 WC Biochemistry & Molecular Biology; Biotechnology & Applied Microbiology SC Biochemistry & Molecular Biology; Biotechnology & Applied Microbiology GA ZP593 UT WOS:000073769000002 ER PT J AU Finkelstein, M Davison, BH AF Finkelstein, M Davison, BH TI Biotechnology for fuels and chemicals - Proceedings of the Nineteenth Symposium on Biotechnology for Fuels and Chemicals held May 4-8, 1997, at Colorado Springs, Colorado - Introduction SO APPLIED BIOCHEMISTRY AND BIOTECHNOLOGY LA English DT Editorial Material C1 Natl Renewable Energy Lab, Golden, CO 80401 USA. Oak Ridge Natl Lab, Oak Ridge, TN USA. RP Finkelstein, M (reprint author), Natl Renewable Energy Lab, Golden, CO 80401 USA. RI Davison, Brian/D-7617-2013 OI Davison, Brian/0000-0002-7408-3609 NR 0 TC 0 Z9 0 U1 0 U2 0 PU HUMANA PRESS INC PI TOTOWA PA 999 RIVERVIEW DRIVE SUITE 208, TOTOWA, NJ 07512 USA SN 0273-2289 J9 APPL BIOCHEM BIOTECH JI Appl. Biochem. Biotechnol. PD SPR PY 1998 VL 70-2 BP III EP VII DI 10.1007/BF02920117 PG 5 WC Biochemistry & Molecular Biology; Biotechnology & Applied Microbiology SC Biochemistry & Molecular Biology; Biotechnology & Applied Microbiology GA ZP593 UT WOS:000073769000001 ER PT J AU Schell, D Nguyen, Q Tucker, M Boynton, B AF Schell, D Nguyen, Q Tucker, M Boynton, B TI Pretreatment of softwood by acid-catalyzed steam explosion followed by alkali extraction SO APPLIED BIOCHEMISTRY AND BIOTECHNOLOGY LA English DT Article; Proceedings Paper CT 19th Symposium on Biotechnology for Fuels and Chemicals CY MAY 04-08, 1997 CL COLORADO SPRINGS, COLORADO DE ethanol; lignocellulosic biomass; lignin extraction; cellulose hydrolysis; alkali ID HYDROLYSIS AB A process for converting lignocellulosic biomass to ethanol hydrolyzes the hemicellulosic fraction to soluble sugars (i.e., pretreatment), followed by acid- or enzyme-catalyzed hydrolysis of the cellulosic fraction. Enzymatic hydrolysis may be improved by using an alkali to extract a fraction of the lignin from the pretreated material. The removal of the lignin may increase the accessibility of the cellulose to enzymatic attack, and thus improve overall economics of the process, if the alkali-treated material can still be effectively converted to ethanol. Pretreated Douglas fir produced by a sulfuric-acid-catalyzed steam explosion was treated with NaOH, NH4OH, and lime to extract some of the lignin. The treated material, along with an untreated control sample, was tested by an enzymatic-digestion procedure, and converted to ethanol by simultaneous saccharification and fermentation using a glucose-fermenting yeast. NaOH was most effective at removing lignin (removed 29%), followed by NH4OH and lime. However, the susceptibility of the treated material to enzymatic digestion was lower than the control and decreased with increasing lignin removal. Ethanol production was similar for the control and NaOH-treated material, and lower for NH4OH- and lime-treated material. C1 Natl Renewable Energy Lab, Golden, CO 80401 USA. RP Schell, D (reprint author), Natl Renewable Energy Lab, Golden, CO 80401 USA. NR 10 TC 21 Z9 24 U1 0 U2 11 PU HUMANA PRESS INC PI TOTOWA PA 999 RIVERVIEW DRIVE SUITE 208, TOTOWA, NJ 07512 USA SN 0273-2289 J9 APPL BIOCHEM BIOTECH JI Appl. Biochem. Biotechnol. PD SPR PY 1998 VL 70-2 BP 17 EP 24 DI 10.1007/BF02920120 PG 8 WC Biochemistry & Molecular Biology; Biotechnology & Applied Microbiology SC Biochemistry & Molecular Biology; Biotechnology & Applied Microbiology GA ZP593 UT WOS:000073769000004 ER PT J AU Tucker, MP Farmer, JD Keller, FA Schell, DJ Nguyen, QA AF Tucker, MP Farmer, JD Keller, FA Schell, DJ Nguyen, QA TI Comparison of yellow poplar pretreatment between NREL digester and sunds hydrolyzer SO APPLIED BIOCHEMISTRY AND BIOTECHNOLOGY LA English DT Article; Proceedings Paper CT 19th Symposium on Biotechnology for Fuels and Chemicals CY MAY 04-08, 1997 CL COLORADO SPRINGS, COLORADO DE biomass; ethanol; dilute-acid pretreatment; bioconversion AB Single-stage cocurrent dilute acid pretreatments were carried out on yellow poplar (Liriodendron tulipifera) sawdust using an as-installed and short residence time modified pilot-scale Sunds hydrolyzer and a 4-L bench-scale NREL digester (steam explosion reactor). Pretreatment conditions for the Sunds hydrolyzer, installed in the NREL process development unit (PDU), which operates at 1 t/d (bone-dry t) feed rate, spanned the temperature range of 160-210 degrees C, 0.1-1.0% (w/w) sulfuric acid, and 4-10-min residence times. The batch pretreatments of yellow poplar sawdust in the bench-scale digester were carried out at 210 and 230 degrees C, 0.26% (w/w) sulfuric acid, and 1-, 3-, and 4-min residence times. The dilute acid prehydrolysis solubilized more than 90% of the hemicellulose, and increased the enzymatic digestibility of the cellulose that remained in the solids. Compositional analysis of the pretreated solids and liquors and mass balance data show that the two pretreatment devices had similar pretreatment performance. C1 Natl Renewable Energy Lab, Golden, CO 80401 USA. RP Tucker, MP (reprint author), Natl Renewable Energy Lab, Golden, CO 80401 USA. NR 14 TC 30 Z9 30 U1 0 U2 4 PU HUMANA PRESS INC PI TOTOWA PA 999 RIVERVIEW DRIVE SUITE 208, TOTOWA, NJ 07512 USA SN 0273-2289 J9 APPL BIOCHEM BIOTECH JI Appl. Biochem. Biotechnol. PD SPR PY 1998 VL 70-2 BP 25 EP 35 DI 10.1007/BF02920121 PG 11 WC Biochemistry & Molecular Biology; Biotechnology & Applied Microbiology SC Biochemistry & Molecular Biology; Biotechnology & Applied Microbiology GA ZP593 UT WOS:000073769000005 ER PT J AU Nguyen, QA Tucker, MP Boynton, BL Keller, FA Schell, DJ AF Nguyen, QA Tucker, MP Boynton, BL Keller, FA Schell, DJ TI Dilute acid pretreatment of softwoods - Scientific note SO APPLIED BIOCHEMISTRY AND BIOTECHNOLOGY LA English DT Article; Proceedings Paper CT 19th Symposium on Biotechnology for Fuels and Chemicals CY MAY 04-08, 1997 CL COLORADO SPRINGS, COLORADO DE biomass; ethanol; pretreatment; softwood; bioconversion AB Selective thinning of forests in the western United States will generate a large, sustainable quantity of softwood residues that can be an attractive feedstock for fuel ethanol production. The major species available from thinning of forests in northern California and the eastern Rocky Mountains include white fir (Abies concolor), Douglas fir (Pseudotsuga menziesii), and Ponderosa pine (Pinus ponderosa). Douglas fir chips were soaked in 0.4% sulfuric acid solution, then pretreated with steam at 200-230 degrees C for 1-5 min. After pretreatment, 90-95% of the hemicellulose and as much as 20% of the cellulose was solubilized in water, and 90% of the remaining cellulose can be hydrolyzed to glucose by cellulase enzyme. The prehydrolysates, at as high as 10% total solid concentration, can be readily fermented by the unadapted yeast Saccharomyces cerevisiae D(5)A. C1 Natl Renewable Energy Lab, Biotechnol Ctr Fuels & Chem, Golden, CO 80401 USA. RP Nguyen, QA (reprint author), Natl Renewable Energy Lab, Biotechnol Ctr Fuels & Chem, Golden, CO 80401 USA. NR 11 TC 64 Z9 65 U1 0 U2 7 PU HUMANA PRESS INC PI TOTOWA PA 999 RIVERVIEW DRIVE SUITE 208, TOTOWA, NJ 07512 USA SN 0273-2289 J9 APPL BIOCHEM BIOTECH JI Appl. Biochem. Biotechnol. PD SPR PY 1998 VL 70-2 BP 77 EP 87 DI 10.1007/BF02920125 PG 11 WC Biochemistry & Molecular Biology; Biotechnology & Applied Microbiology SC Biochemistry & Molecular Biology; Biotechnology & Applied Microbiology GA ZP593 UT WOS:000073769000009 ER PT J AU Jeffries, T Himmel, M AF Jeffries, T Himmel, M TI Applied biological research SO APPLIED BIOCHEMISTRY AND BIOTECHNOLOGY LA English DT Editorial Material C1 US Forest Serv, Forest Prod Lab, Madison, WI 53705 USA. NREL, Golden, CO USA. RP Jeffries, T (reprint author), US Forest Serv, Forest Prod Lab, 1 Gifford Pinchot Dr, Madison, WI 53705 USA. OI Jeffries, Thomas/0000-0001-7408-4065 NR 0 TC 0 Z9 0 U1 0 U2 2 PU HUMANA PRESS INC PI TOTOWA PA 999 RIVERVIEW DRIVE SUITE 208, TOTOWA, NJ 07512 USA SN 0273-2289 J9 APPL BIOCHEM BIOTECH JI Appl. Biochem. Biotechnol. PD SPR PY 1998 VL 70-2 BP 113 EP 114 DI 10.1007/BF02920128 PG 2 WC Biochemistry & Molecular Biology; Biotechnology & Applied Microbiology SC Biochemistry & Molecular Biology; Biotechnology & Applied Microbiology GA ZP593 UT WOS:000073769000012 ER PT J AU Keller, FA Bates, D Ruiz, R Nguyen, Q AF Keller, FA Bates, D Ruiz, R Nguyen, Q TI Yeast adaptation on softwood prehydrolysate SO APPLIED BIOCHEMISTRY AND BIOTECHNOLOGY LA English DT Article; Proceedings Paper CT 19th Symposium on Biotechnology for Fuels and Chemicals CY MAY 04-08, 1997 CL COLORADO SPRINGS, COLORADO DE yeast; adaptation; softwood; ethanol; fermentation AB Several strains and genera of yeast, including Saccharomyces cerevisiae D(5)A, Pachysolen tannophilus, S. cerevisiae K-1, Brettanomyces custersii, Candida shehatae, and Candida acidothermophilum, are screened for growth on dilute acid-pretreated softwood prehydrolysate. Selected softwood species found in forest underbrush of the western United States, which contain predominantly hexosan hemicellulose, were studied. This phase of the work emphasized debarked Douglas fir. The two best initial isolates were gradually selected for improved growth by adaptation to increasing prehydrolysate concentrations in batch culture, with due consideration of nutrient requirements. Microaerophilic conditions were evaluated to encourage tolerance of pretreatment hydrolysate, as well as ethanol product. Adaptation and simultaneous saccharification and fermentation (SSF) results are used to illustrate improved performance with an adapted strain, compared to the wild type. C1 Natl Renewable Energy Lab, Biotechnol Ctr Fuels & Chem, Golden, CO 80401 USA. RP Keller, FA (reprint author), Natl Renewable Energy Lab, Biotechnol Ctr Fuels & Chem, Golden, CO 80401 USA. NR 2 TC 21 Z9 22 U1 0 U2 4 PU HUMANA PRESS INC PI TOTOWA PA 999 RIVERVIEW DRIVE SUITE 208, TOTOWA, NJ 07512 USA SN 0273-2289 J9 APPL BIOCHEM BIOTECH JI Appl. Biochem. Biotechnol. PD SPR PY 1998 VL 70-2 BP 137 EP 148 DI 10.1007/BF02920131 PG 12 WC Biochemistry & Molecular Biology; Biotechnology & Applied Microbiology SC Biochemistry & Molecular Biology; Biotechnology & Applied Microbiology GA ZP593 UT WOS:000073769000015 PM 9627379 ER PT J AU Donnelly, MI Millard, CS Clark, DP Chen, MJ Rathke, JW AF Donnelly, MI Millard, CS Clark, DP Chen, MJ Rathke, JW TI A novel fermentation pathway in an Escherichia coli mutant producing succinic acid, acetic acid, and ethanol SO APPLIED BIOCHEMISTRY AND BIOTECHNOLOGY LA English DT Article; Proceedings Paper CT 19th Symposium on Biotechnology for Fuels and Chemicals CY MAY 04-08, 1997 CL COLORADO SPRINGS, COLORADO DE Escherichia coli; fermentation; succinic acid ID DEHYDROGENASE; GROWTH AB Escherichia coli strain NZN111, which is unable to grow fermentatively because of insertional inactivation of the genes encoding pyruvate: formate lyase and the fermentative lactate dehydrogenase, gave rise spontaneously to a chromosomal mutation that restored its ability to ferment glucose. The mutant strain, named AFP111, fermented glucose more slowly than did its wild-type ancestor, strain W1485, and generated a very different spectrum of products. AFP111 produced succinic acid, acetic acid, and ethanol in proportions of approx 2:1:1. Calculations of carbon and electron balances accounted fully for the observed products; 1 mol of glucose was converted to 1 mol of succinic acid and 0.5 mol each of acetic acid and ethanol. The data support the emergence in E. coli of a novel succinic acid:acetic acid:ethanol fermentation pathway. C1 Argonne Natl Lab, Div Environm Res, Argonne, IL 60439 USA. Argonne Natl Lab, Div Chem Technol, Argonne, IL 60439 USA. So Illinois Univ, Dept Microbiol, Carbondale, IL 62901 USA. RP Donnelly, MI (reprint author), Argonne Natl Lab, Div Environm Res, Argonne, IL 60439 USA. NR 14 TC 71 Z9 74 U1 4 U2 15 PU HUMANA PRESS INC PI TOTOWA PA 999 RIVERVIEW DRIVE SUITE 208, TOTOWA, NJ 07512 USA SN 0273-2289 J9 APPL BIOCHEM BIOTECH JI Appl. Biochem. Biotechnol. PD SPR PY 1998 VL 70-2 BP 187 EP 198 DI 10.1007/BF02920135 PG 12 WC Biochemistry & Molecular Biology; Biotechnology & Applied Microbiology SC Biochemistry & Molecular Biology; Biotechnology & Applied Microbiology GA ZP593 UT WOS:000073769000019 PM 9627382 ER PT J AU Mohagheghi, A Evans, K Finkelstein, M Zhang, M AF Mohagheghi, A Evans, K Finkelstein, M Zhang, M TI Cofermentation of glucose, xylose, and arabinose by mixed cultures of two genetically engineered Zymomonas mobilis strains SO APPLIED BIOCHEMISTRY AND BIOTECHNOLOGY LA English DT Article; Proceedings Paper CT 19th Symposium on Biotechnology for Fuels and Chemicals CY MAY 04-08, 1997 CL COLORADO SPRINGS, COLORADO DE recombinant Zymomonas; ethanol; cofermentation; xylose; arabinose; mixed culture fermentation ID PATHWAY AB Cofermentation of xylose and arabinose, in addition to glucose, is critical for complete bioconversion of lignocellulosic biomass, such as agricultural residues and herbaceous energy crops, to ethanol. A factorial design experiment was used to evaluate the cofermentation of glucose, xylose, and arabinose with mixed cultures of two genetically engineered Zymontonas mobilis strains (one ferments xylose and the other arabinose). The pH range studied was 5.0-6.0, and the temperature range was 30-37 degrees C. The individual sugar concentrations used were 30 g/L glucose, 30 g/L xylose, and 20 g/L arabinose. The optimal cofermentation conditions obtained by data analysis, using Design Expert software, were pH 5.85 and temperature 31.5 degrees C. The cofermentation process yield at optimal conditions was 72.5% of theoritical maximum. The results showed that neither the arabinose strain nor arabinose affected the performance of the xylose strain; however, both xylose strain and xylose had a significant effect on the performance of the arabinose strain. Although cofermentation of all three sugars is achieved by the mixed cultures, there is a preferential order of sugar utilization. Glucose is used rapidly, then xylose, followed by arabinose. C1 Natl Renewable Energy Lab, Biotechnol Ctr Fuels & Chem, Golden, CO 80401 USA. RP Mohagheghi, A (reprint author), Natl Renewable Energy Lab, Biotechnol Ctr Fuels & Chem, Golden, CO 80401 USA. NR 12 TC 17 Z9 17 U1 0 U2 2 PU HUMANA PRESS INC PI TOTOWA PA 999 RIVERVIEW DRIVE SUITE 208, TOTOWA, NJ 07512 USA SN 0273-2289 J9 APPL BIOCHEM BIOTECH JI Appl. Biochem. Biotechnol. PD SPR PY 1998 VL 70-2 BP 285 EP 299 DI 10.1007/BF02920145 PG 15 WC Biochemistry & Molecular Biology; Biotechnology & Applied Microbiology SC Biochemistry & Molecular Biology; Biotechnology & Applied Microbiology GA ZP593 UT WOS:000073769000029 PM 18575998 ER PT J AU Lawford, HG Rousseau, JD Mohagheghi, A McMillan, JD AF Lawford, HG Rousseau, JD Mohagheghi, A McMillan, JD TI Continuous culture studies of xylose-fermenting Zymomonas mobilis SO APPLIED BIOCHEMISTRY AND BIOTECHNOLOGY LA English DT Article; Proceedings Paper CT 19th Symposium on Biotechnology for Fuels and Chemicals CY MAY 04-08, 1997 CL COLORADO SPRINGS, COLORADO DE adaptation; continuous cofermentation; ethanol; xylose; Zymomonas mobilis ID ENZYMATIC-HYDROLYSIS; CELLULOSIC BIOMASS; FUEL ETHANOL; FERMENTATION; GROWTH; MAINTENANCE; METABOLISM; CELLS AB The continuous cofermentation performance of xylose-fermenting Zymomonas mobilis at 30 degrees C and pH 5.5 was characterized using a pure-sugar feed solution that contained 8 g/L glucose and 40 g/L xylose. Successful chemostat start up resulted in complete utilization of glucose and greater than 85% utilization of xylose, but was only reproducibly achieved using initial dilution rates at or less than 0.04/h; once initiated, cofermentation could be maintained at dilution rates of 0.04 to 0.10/h. Whereas xylose and cell-mass concentrations increased gradually with increasing dilution rate, ethanol concentrations and ethanol yields on available sugars remained approximately constant at 20-22 g/L and 80-90% of theoretical, respectively. Volumetric and specific ethanol productivities increased Linearly with increasing dilution rate, rising from approx 1.0 each (g/L/h or g/g/h) at a dilution rate of 0.04/h to approx 2.0 each (g/L/h or g/g/h) at a dilution rate of 0.10/h. Similarly, specific sugar-utilization rates increased from approx 2.0 g/g/h at dilution rate 0.04/h to approx 3.5 g/g/h at dilution rate of 0.10/h. The estimated values of 0.042 g/g for the maximum Z, mobilis cell-mass yield on substrate and 1.13 g/g/h for the minimum specific substrate utilization rate required for cellular maintenance energy are within the range of values reported in the Literature. Results are also presented which suggest that long-term adaptation in continuous culture is a powerful technique for developing strains with higher tolerance to inhibitory hemicellulose hydrolyzates. C1 Natl Renewable Energy Lab, Biotechnol Ctr Fuels & Chem, Golden, CO 80401 USA. Univ Toronto, Dept Biochem, Bioengn Lab, Toronto, ON M5S 1A8, Canada. RP McMillan, JD (reprint author), Natl Renewable Energy Lab, Biotechnol Ctr Fuels & Chem, 1617 Cole Blvd, Golden, CO 80401 USA. NR 45 TC 29 Z9 29 U1 0 U2 1 PU HUMANA PRESS INC PI TOTOWA PA 999 RIVERVIEW DRIVE SUITE 208, TOTOWA, NJ 07512 USA SN 0273-2289 J9 APPL BIOCHEM BIOTECH JI Appl. Biochem. Biotechnol. PD SPR PY 1998 VL 70-2 BP 353 EP 367 DI 10.1007/BF02920151 PG 15 WC Biochemistry & Molecular Biology; Biotechnology & Applied Microbiology SC Biochemistry & Molecular Biology; Biotechnology & Applied Microbiology GA ZP593 UT WOS:000073769000035 PM 18576004 ER PT J AU Baker, JO Ehrman, CI Adney, WS Thomas, SR Himmel, ME AF Baker, JO Ehrman, CI Adney, WS Thomas, SR Himmel, ME TI Hydrolysis of cellulose using ternary mixtures of purified celluloses SO APPLIED BIOCHEMISTRY AND BIOTECHNOLOGY LA English DT Article; Proceedings Paper CT 19th Symposium on Biotechnology for Fuels and Chemicals CY MAY 04-08, 1997 CL COLORADO SPRINGS, CO DE cellulases; Trichoderma reesei; Aspergillus niger; Acidothermus cellulolyticus; Thermomonospora fusca; Microbispora bispora ID THERMOMONOSPORA-FUSCA; TRICHODERMA-REESEI; CELLULASES AB The saccharification of microcrystalline cellulose by reconstituted ternary mixtures of purified cellulases (one endoglucanase and two cellobiohydrolases) has been studied over the entire range of mixture compositions. Ternary plots are used to compare the performance of five synthetic mixtures drawn from the cellulase systems of Acidothermus cellulolyticus, Trichoderma reesei, Thermomonospora fusca, and Thermotoga neapolitana. Results reveal that at least one synthetic mixture utilizing enzymes from three different organisms delivers performance competitive with that of a "native" (i.e., co-evolved) ternary system drawn exclusively from T. reesei. This heterologous system, consisting of the endoglucanase El from A. cellulolyticus and the exoglucanases CBHI from T, ressei and E-3 from T, fusca, is forgiving from the system-design point of view, in that it delivers high saccharification rates over a wide range of mixture compositions. C1 Natl Renewable Energy Lab, Biotechnol Ctr Fuels & Chem, Golden, CO 80401 USA. RP Baker, JO (reprint author), Natl Renewable Energy Lab, Biotechnol Ctr Fuels & Chem, Golden, CO 80401 USA. NR 14 TC 68 Z9 70 U1 1 U2 10 PU HUMANA PRESS INC PI TOTOWA PA 999 RIVERVIEW DRIVE SUITE 208, TOTOWA, NJ 07512 USA SN 0273-2289 EI 1559-0291 J9 APPL BIOCHEM BIOTECH JI Appl. Biochem. Biotechnol. PD SPR PY 1998 VL 70-2 BP 395 EP 403 DI 10.1007/BF02920154 PG 9 WC Biochemistry & Molecular Biology; Biotechnology & Applied Microbiology SC Biochemistry & Molecular Biology; Biotechnology & Applied Microbiology GA ZP593 UT WOS:000073769000038 PM 9627391 ER PT J AU Bajpai, R Glassner, DA AF Bajpai, R Glassner, DA TI Bioprocessing research SO APPLIED BIOCHEMISTRY AND BIOTECHNOLOGY LA English DT Editorial Material C1 Univ Missouri, Columbia, MO 65201 USA. Natl Renewable Energy Lab, Golden, CO USA. RP Bajpai, R (reprint author), Univ Missouri, Columbia, MO 65201 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU HUMANA PRESS INC PI TOTOWA PA 999 RIVERVIEW DRIVE SUITE 208, TOTOWA, NJ 07512 USA SN 0273-2289 J9 APPL BIOCHEM BIOTECH JI Appl. Biochem. Biotechnol. PD SPR PY 1998 VL 70-2 BP 415 EP 415 DI 10.1007/BF02920156 PG 1 WC Biochemistry & Molecular Biology; Biotechnology & Applied Microbiology SC Biochemistry & Molecular Biology; Biotechnology & Applied Microbiology GA ZP593 UT WOS:000073769000040 ER PT J AU Tsai, SP Moon, SH AF Tsai, SP Moon, SH TI An integrated bioconversion process for production of L-lactic acid from starchy potato feedstocks SO APPLIED BIOCHEMISTRY AND BIOTECHNOLOGY LA English DT Article; Proceedings Paper CT 19th Symposium on Biotechnology for Fuels and Chemicals CY MAY 04-08, 1997 CL COLORADO SPRINGS, COLORADO DE lactic acid; starch; simultaneous saccharification and fermentation ID FERMENTATION AB The potential market for lactic acid as the feedstock for biodegradable polymers, oxygenated chemicals, and specialty chemicals is significant. L-lactic acid is often the desired enantiomer for such applications. However, stereospecific lactobacilli do not metabolize starch efficiently. In this work, Argonne researchers have developed a process to convert starchy feedstocks into L-lactic acid. The processing steps include starch recovery, continuous liquefaction, and simultaneous saccharification and fermentation. Over 100 g/L of lactic acid was produced in less than 48 h. The optical purity of the product was greater than 95%. This process has potential economical advantages over the conventional process. C1 Argonne Natl Lab, Argonne, IL 60439 USA. RP Tsai, SP (reprint author), Argonne Natl Lab, 9700 S Cass Ave, Argonne, IL 60439 USA. NR 10 TC 23 Z9 24 U1 1 U2 2 PU HUMANA PRESS INC PI TOTOWA PA 999 RIVERVIEW DRIVE SUITE 208, TOTOWA, NJ 07512 USA SN 0273-2289 J9 APPL BIOCHEM BIOTECH JI Appl. Biochem. Biotechnol. PD SPR PY 1998 VL 70-2 BP 417 EP 428 DI 10.1007/BF02920157 PG 12 WC Biochemistry & Molecular Biology; Biotechnology & Applied Microbiology SC Biochemistry & Molecular Biology; Biotechnology & Applied Microbiology GA ZP593 UT WOS:000073769000041 PM 18576010 ER PT J AU Sun, MY Nghiem, NP Davison, BH Webb, OF Bienkowski, PR AF Sun, MY Nghiem, NP Davison, BH Webb, OF Bienkowski, PR TI Production of ethanol from starch by co-immobilized Zymomonas mobilis-glucoamylase in a fluidized-bed reactor SO APPLIED BIOCHEMISTRY AND BIOTECHNOLOGY LA English DT Article; Proceedings Paper CT 19th Symposium on Biotechnology for Fuels and Chemicals CY MAY 04-08, 1997 CL COLORADO SPRINGS, COLORADO DE ethanol; starch; Zymomonas mobilis; glucoamylase; simultaneous saccharification and fermentation; fluidized-bed reactor ID FERMENTATION; BIOREACTOR AB The production of ethanol from starch was studied in a fluidized-bed reactor (FBR) using co-immobilized Zymomonas mobilis and glucoamylase. The FBR was a glass column of 2.54 cm in diameter and 120 cm in length. The Z. mobilis and glucoamylase were co-immobilized within small uniform beads (1.2-2.5 mm diameter) of kappa-carrageenan. The substrate for ethanol production was a soluble starch. Light steep water was used as the complex nutrient source. The experiments were performed at 35 degrees C and pH range of 4.0-5.5. The substrate concentrations ranged from 40 to 185 g/L, and the feed rates from 10 to 37 mL/min. Under relaxed sterility conditions, the FBR was successfully operated for a period of 22 d, during which no contamination or structural failure of the biocatalyst beads was observed. Volumetric productivity as high as 38 g ethanol/(Lh), which was 74% of the maximum expected value, was obtained. Typical ethanol volumetric productivity was in the range of 15-20 g/(Lh). The average yield was 0.49 g ethanol/g substrate consumed, which was 90% of the theoretical yield. Very low levels of glucose were observed in the reactor, indicating that starch hydrolysis was the rate-limiting step. C1 Oak Ridge Natl Lab, Bioproc Res & Dev Ctr, Oak Ridge, TN 37831 USA. Univ Tennessee, Dept Chem Engn, Knoxville, TN 37916 USA. RP Nghiem, NP (reprint author), Oak Ridge Natl Lab, Bioproc Res & Dev Ctr, POB 2008, Oak Ridge, TN 37831 USA. RI Davison, Brian/D-7617-2013 OI Davison, Brian/0000-0002-7408-3609 NR 12 TC 12 Z9 12 U1 0 U2 1 PU HUMANA PRESS INC PI TOTOWA PA 999 RIVERVIEW DRIVE SUITE 208, TOTOWA, NJ 07512 USA SN 0273-2289 J9 APPL BIOCHEM BIOTECH JI Appl. Biochem. Biotechnol. PD SPR PY 1998 VL 70-2 BP 429 EP 439 DI 10.1007/BF02920158 PG 11 WC Biochemistry & Molecular Biology; Biotechnology & Applied Microbiology SC Biochemistry & Molecular Biology; Biotechnology & Applied Microbiology GA ZP593 UT WOS:000073769000042 PM 18576011 ER PT J AU Klasson, KT Lundback, KMO Clausen, EC Gaddy, JL AF Klasson, KT Lundback, KMO Clausen, EC Gaddy, JL TI In situ global method for measurement of oxygen demand and mass transfer SO APPLIED BIOCHEMISTRY AND BIOTECHNOLOGY LA English DT Article; Proceedings Paper CT 19th Symposium on Biotechnology for Fuels and Chemicals CY MAY 04-08, 1997 CL COLORADO SPRINGS, COLORADO ID CITRIC-ACID; GLUCOSE AB Two aerobic microorganisms, Saccharomycopsis lipolytica and Brevibacterium lactofermentum, have been used in a study of mass transfer and oxygen uptake from a global perspective, using a closed gas system. Oxygen concentrations in the gas and liquid were followed using oxygen electrodes; the results allowed for easy calculation of in situ oxygen transport. The cell yields on oxygen for S. lipolytica and B. lactofermentum were 1.01 and 1.53 g/g, respectively. The mass transfer coefficient was estimated as 10/h at 500 rpm for both fermentations. The advantages with this method are noticeable, since the use of model systems may be avoided, and the in situ measurements of oxygen demand assure reliable data for scale-up. C1 Oak Ridge Natl Lab, Div Chem Technol, Oak Ridge, TN 37831 USA. Univ Arkansas, Dept Chem Engn, Fayetteville, AR 72701 USA. RP Klasson, KT (reprint author), Oak Ridge Natl Lab, Div Chem Technol, Oak Ridge, TN 37831 USA. OI Klasson, K. Thomas/0000-0003-3358-3081 NR 8 TC 0 Z9 0 U1 0 U2 0 PU HUMANA PRESS INC PI TOTOWA PA 999 RIVERVIEW DRIVE SUITE 208, TOTOWA, NJ 07512 USA SN 0273-2289 J9 APPL BIOCHEM BIOTECH JI Appl. Biochem. Biotechnol. PD SPR PY 1998 VL 70-2 BP 527 EP 533 PG 7 WC Biochemistry & Molecular Biology; Biotechnology & Applied Microbiology SC Biochemistry & Molecular Biology; Biotechnology & Applied Microbiology GA ZP593 UT WOS:000073769000049 PM 18576018 ER PT J AU Rivard, CJ Duff, BW Nagle, NJ AF Rivard, CJ Duff, BW Nagle, NJ TI Development of a novel, two-step process for treating municipal biosolids for beneficial reuse SO APPLIED BIOCHEMISTRY AND BIOTECHNOLOGY LA English DT Article; Proceedings Paper CT 19th Symposium on Biotechnology for Fuels and Chemicals CY MAY 04-08, 1997 CL COLORADO SPRINGS, COLORADO DE sewage sludge; biosolids; thermal mechanical treatment; beneficial reuse AB Modern municipal sewage waste treatment plants use conventional mechanical and biological processes to reclaim wastewaters. This process has an overall effect of converting a water pollution problem into a solid waste disposal problem (sludges or biosolids). An estimated 10 million tons of biosolids, which require final disposal, are produced annually in the United States. Although numerous disposal options for biosolids are available, Including land application, landfilling, and incineration, disposal costs have risen, partly because of increased federal and local environmental restrictions (1). A novel, thermomechanical biosolids pretreatment process, which allows for a variety of potential value-added uses, was developed. This two-step process first employs thermal explosive decompression to inactivate or kill the microbial cells and viruses. This primary step also results in the rupture of a small amount of the microbial biomass and increases the intrinsic fluidity of the biosolids. The second step uses shear to effect a near-complete rupturing of the microbial biomass, and shears the nondigested organics, which increases the overall surface area. Pretreated biosolids may be subjected to a secondary anaerobic digestion process to produce additional fuel gas, and to provide for a high-quality, easily dewatered compost product. This novel biosolids pretreatment process was recently allowed a United States patent. C1 Peak Treatment Syst Inc, Golden, CO 80401 USA. Natl Renewable Energy Lab, Golden, CO 80401 USA. RP Rivard, CJ (reprint author), Peak Treatment Syst Inc, Golden, CO 80401 USA. NR 5 TC 5 Z9 5 U1 2 U2 5 PU HUMANA PRESS INC PI TOTOWA PA 999 RIVERVIEW DRIVE SUITE 208, TOTOWA, NJ 07512 USA SN 0273-2289 J9 APPL BIOCHEM BIOTECH JI Appl. Biochem. Biotechnol. PD SPR PY 1998 VL 70-2 BP 569 EP 577 DI 10.1007/BF02920169 PG 9 WC Biochemistry & Molecular Biology; Biotechnology & Applied Microbiology SC Biochemistry & Molecular Biology; Biotechnology & Applied Microbiology GA ZP593 UT WOS:000073769000053 PM 18576022 ER PT J AU Rivard, CJ Duff, BW Dickow, JH Wiles, CC Nagle, NJ Gaddy, JL Clausen, EC AF Rivard, CJ Duff, BW Dickow, JH Wiles, CC Nagle, NJ Gaddy, JL Clausen, EC TI Demonstration-scale evaluation of a novel high-solids anaerobic digestion process for converting organic wastes to fuel gas and compost SO APPLIED BIOCHEMISTRY AND BIOTECHNOLOGY LA English DT Article; Proceedings Paper CT 19th Symposium on Biotechnology for Fuels and Chemicals CY MAY 04-08, 1997 CL COLORADO SPRINGS, COLORADO DE high solids; anaerobic digestion; biogas; cogeneration; pilot-scale ID REACTOR; ENZYMES; BIOCONVERSION; REQUIREMENTS; DEGRADATION AB Early evaluations of the bioconversion potential for combined wastes such as tuna sludge and sorted municipal solid waste (MSW) were conducted at laboratory scale and compared conventional low-solids, stirred-tank anaerobic systems with the novel, high-solids anaerobic digester (HSAD) design. Enhanced feedstock conversion rates and yields were determined for the HSAD system. In addition, the HSAD system demonstrated superior resiliency to process failure. Utilizing relatively dry feedstocks, the HSAD system is approximately one-tenth the size of conventional low-solids systems. In addition, the HSAD system is capable of organic loading rates (OLRs) on the order of 20-25 g volatile solids per liter digester volume per d (gVS/L/d), roughly 4-5 times those of conventional systems. Current efforts involve developing a demonstration-scale (pilot-scale) HSAD system. A two-ton/d plant has been constructed in Stanton, CA and is currently in the commissioning/startup phase. The purposes of the project are to verify laboratory-and intermediate-scale process performance; test the performance of large-scale prototype mechanical systems; demonstrate the long-term reliability of the process; and generate the process and economic data required for the design, financing, and construction of full-scale commercial systems. This study presents conformational fermentation data obtained at intermediate-scale and a snapshot of the pilot-scale project. C1 Pinnacle Biotechnol Int Inc, Golden, CO USA. Natl Renewable Energy Lab, Golden, CO USA. Bioengn Resources Inc, Fayetteville, AR USA. RP Rivard, CJ (reprint author), Pinnacle Biotechnol Int Inc, Golden, CO USA. NR 31 TC 5 Z9 6 U1 1 U2 8 PU HUMANA PRESS INC PI TOTOWA PA 999 RIVERVIEW DRIVE SUITE 208, TOTOWA, NJ 07512 USA SN 0273-2289 J9 APPL BIOCHEM BIOTECH JI Appl. Biochem. Biotechnol. PD SPR PY 1998 VL 70-2 BP 687 EP 695 DI 10.1007/BF02920180 PG 9 WC Biochemistry & Molecular Biology; Biotechnology & Applied Microbiology SC Biochemistry & Molecular Biology; Biotechnology & Applied Microbiology GA ZP593 UT WOS:000073769000064 PM 18576033 ER PT J AU Hinman, ND Yancey, MA AF Hinman, ND Yancey, MA TI Use of net present value analysis to evaluate a publicly funded biomass-to-ethanol research, development, and demonstration program and valuate expected private sector participation SO APPLIED BIOCHEMISTRY AND BIOTECHNOLOGY LA English DT Article; Proceedings Paper CT 19th Symposium on Biotechnology for Fuels and Chemicals CY MAY 04-08, 1997 CL COLORADO SPRINGS, CO AB One of the functions of government is to invest tax dollars in programs, projects, and properties that will result in greater public benefit than would have resulted from leaving the tax dollars in the private sector or using them to pay off the public debt. This paper describes the use of Net Present Value (NPV) as an approach to analyze and select investment opportunities for government money in public research, development, and demonstration (RD&D) programs and to evaluate potential private sector participation in the programs. This approach is then applied to a specific biomass-to-ethanol opportunity in California. C1 Natl Renewable Energy Lab, Ctr Renewable Fuels & Biotechnol, Golden, CO 80401 USA. RP Hinman, ND (reprint author), Natl Renewable Energy Lab, Ctr Renewable Fuels & Biotechnol, Golden, CO 80401 USA. NR 8 TC 0 Z9 0 U1 0 U2 0 PU HUMANA PRESS INC PI TOTOWA PA 999 RIVERVIEW DRIVE SUITE 208, TOTOWA, NJ 07512 USA SN 0273-2289 J9 APPL BIOCHEM BIOTECH JI Appl. Biochem. Biotechnol. PD SPR PY 1998 VL 70-2 BP 807 EP 819 DI 10.1007/BF02920191 PG 13 WC Biochemistry & Molecular Biology; Biotechnology & Applied Microbiology SC Biochemistry & Molecular Biology; Biotechnology & Applied Microbiology GA ZP593 UT WOS:000073769000075 PM 18576044 ER PT J AU Dorsch, R Nghiem, N AF Dorsch, R Nghiem, N TI Specialty chemicals with emphasis on environmentally benign products and processes SO APPLIED BIOCHEMISTRY AND BIOTECHNOLOGY LA English DT Editorial Material C1 Dupont Co, Wilmington, DE 19898 USA. Oak Ridge Natl Lab, Oak Ridge, TN USA. RP Dorsch, R (reprint author), Dupont Co, Wilmington, DE 19898 USA. NR 0 TC 3 Z9 3 U1 0 U2 0 PU HUMANA PRESS INC PI TOTOWA PA 999 RIVERVIEW DRIVE SUITE 208, TOTOWA, NJ 07512 USA SN 0273-2289 J9 APPL BIOCHEM BIOTECH JI Appl. Biochem. Biotechnol. PD SPR PY 1998 VL 70-2 BP 843 EP 844 DI 10.1007/BF02920193 PG 2 WC Biochemistry & Molecular Biology; Biotechnology & Applied Microbiology SC Biochemistry & Molecular Biology; Biotechnology & Applied Microbiology GA ZP593 UT WOS:000073769000077 ER PT J AU Thompson, DN Hames, BR Reddy, CA Grethlein, HE AF Thompson, DN Hames, BR Reddy, CA Grethlein, HE TI In vitro degradation of insoluble lignin in aqueous media by lignin peroxidase and manganese peroxidase SO APPLIED BIOCHEMISTRY AND BIOTECHNOLOGY LA English DT Article; Proceedings Paper CT 19th Symposium on Biotechnology for Fuels and Chemicals CY MAY 04-08, 1997 CL COLORADO SPRINGS, CO DE lignin peroxidase (LIP); manganese peroxidase (MNP); Phanerochaete chrysosporium ID TRANSFORM INFRARED SPECTROMETRY; PHANEROCHAETE-CHRYSOSPORIUM; OXIDATION; CHELATORS AB The abilities of lignin peroxidase (LIP) and manganese peroxidase (MNP) from Phanerochaete chrysosporium to degrade an insoluble hardwood Lignin in vitro in aqueous media were tested. Neither LIP nor MNP appreciably changed the mass or lignin content, although both produced small amounts of unique solubilized lignin fragments. Treatment with both LIP and MNP, however, decreased the mass by 11%, decreased the lignin content by 5.1% (4.2% as total weight), and solubilized unique Lignin-derived molecules. These results suggest that LIP and MNP synergistically degrade high molecular weight insoluble lignin, but singly, neither enzyme is sufficient to effect lignin degradation. C1 Michigan State Univ, Dept Chem Engn, E Lansing, MI 48824 USA. Michigan State Univ, NSF, Ctr Microbial Ecol, E Lansing, MI 48824 USA. Natl Renewable Energy Lab, Biomass Anal Grp, Golden, CO 80401 USA. Michigan State Univ, Dept Microbiol, E Lansing, MI 48824 USA. Michigan Biotechnol Inst, Lansing, MI 48909 USA. RP Idaho Natl Lab, Dept Biotechnol, POB 1625, Idaho Falls, ID 83415 USA. NR 22 TC 6 Z9 6 U1 0 U2 1 PU HUMANA PRESS INC PI TOTOWA PA 999 RIVERVIEW DRIVE SUITE 208, TOTOWA, NJ 07512 USA SN 0273-2289 EI 1559-0291 J9 APPL BIOCHEM BIOTECH JI Appl. Biochem. Biotechnol. PD SPR PY 1998 VL 70-2 BP 967 EP 982 DI 10.1007/BF02920207 PG 16 WC Biochemistry & Molecular Biology; Biotechnology & Applied Microbiology SC Biochemistry & Molecular Biology; Biotechnology & Applied Microbiology GA ZP593 UT WOS:000073769000091 PM 18576060 ER PT J AU Fuhrmann, M Bajt, S Schoonen, MAA AF Fuhrmann, M Bajt, S Schoonen, MAA TI Sorption of iodine on minerals investigated by X-ray absorption near edge structure (XANES) and I-125 tracer sorption experiments SO APPLIED GEOCHEMISTRY LA English DT Article ID IRON-OXIDES; OXIDATION; PYRITE; SOIL; ENVIRONMENT; RADIOIODINE; ADSORPTION; BEHAVIOR; IODATE; WATER AB The sorption of I on a set of selected minerals was examined by: X-ray absorption near edge structure (XANES) and high concentration chemical sorption experiments, as well as very low concentration tracer (using I-123) sorption experiments. A XANES method was used to determine I-2, I(V) and I (-I) in supernatant solutions and slurries of minerals, This is, we believe, the first reported use of XANES to investigate the redox state of I that is sorbed on minerals. With this technique, it was determined that pyrite, biotite and magnetite sorb I from solutions containing 1000 mu g ml(-1) I. In the pyrite/water system, IO3- was reduced to what appeared to be I-2 in the XANES scans and sorbed on the minerals surface. Magnetite sorbed I- from solution but not IO3-. In contrast, biotite sorbed IO3- from solution but did not take up any I-. No changes in I redox state were observed in the magnetite and biotite experiments. Based on this association the presence of Fe(II) in the sorbing phase appears to be related to uptake, but not necessarily to a change in I redox. Results of the XANES experiments, in which high concentrations of I were used, were corroborated for IO3- with pyrite, magnetite and biotite at very low concentrations of I-125. Most of the other minerals tested sorbed small fractions of the I-125 tracer, but this level of uptake could not be observed in XANES scans. To examine the relationship between pyrite and IO3-, experiments were conducted in which concentrations of Fe, I, S2- and SO42- were determined in the aqueous phase of slurries containing pyrite. In the presence of I (starting as IO3-), concentrations of Fe in solution were significantly lower than without I, even at pH values sufficiently low that Fe should stay in solution. The XANES spectra indicate that I-2 is present on this material, eliminating the possibility of FeI2 formation where I is present as I-. The implication is that I-2, sorbed on the surface, inhibits release of Fe to solution (or promotes its precipitation)while S is oxidized to SO42- and released. (C) 1998 Elsevier Science Ltd. All rights reserved. C1 Brookhaven Natl Lab, Environm & Waste Technol Ctr, Dept Adv Technol, Upton, NY 11973 USA. Univ Chicago, Chicago, IL 60637 USA. RP Fuhrmann, M (reprint author), Brookhaven Natl Lab, Environm & Waste Technol Ctr, Dept Adv Technol, POB 5000, Upton, NY 11973 USA. RI Bajt, Sasa/G-2228-2010 NR 59 TC 50 Z9 50 U1 5 U2 19 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0883-2927 J9 APPL GEOCHEM JI Appl. Geochem. PD MAR PY 1998 VL 13 IS 2 BP 127 EP 141 DI 10.1016/S0883-2927(97)00068-1 PG 15 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA ZP306 UT WOS:000073739100001 ER PT J AU Peierls, RF Deng, Y AF Peierls, RF Deng, Y TI An asynchronous decomposition approach to parallel global optimization SO APPLIED MATHEMATICS LETTERS LA English DT Article DE simulated annealing; global optimization; parallel computing; asynchronous; Lennard-Jones clusters AB We introduce an alternating decomposition approach for solving global optimization problems on parallel computers. The method is based on decomposing moves in the state space into components which can be optimized concurrently. A number of features distinguish our approach from others which have been proposed in the literature. We report the results of applying the approach to energy minimization of Lennard-Jones clusters using simulated annealing. We find that the new approach is robust, has high parallel efficiency, and it can rapidly generate a good approximation to the molecular conformation. C1 Brookhaven Natl Lab, Dept Appl Sci, Upton, NY 11973 USA. SUNY Stony Brook, Dept Appl Math & Stat, Stony Brook, NY 11794 USA. RP Peierls, RF (reprint author), Brookhaven Natl Lab, Dept Appl Sci, Upton, NY 11973 USA. OI Deng, Yuefan/0000-0002-5224-3958 NR 5 TC 1 Z9 1 U1 0 U2 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0893-9659 J9 APPL MATH LETT JI Appl. Math. Lett. PD MAR PY 1998 VL 11 IS 2 BP 55 EP 59 DI 10.1016/S0893-9659(98)00011-1 PG 5 WC Mathematics, Applied SC Mathematics GA ZB028 UT WOS:000072427600011 ER PT J AU Shapira, Y AF Shapira, Y TI Multigrid methods for 3-D definite and indefinite problems SO APPLIED NUMERICAL MATHEMATICS LA English DT Article ID NONSYMMETRIC LINEAR-SYSTEMS; MINIMAL RESIDUAL ALGORITHM; BOUNDARY-VALUE-PROBLEMS; COEFFICIENTS; SOLVER AB A multigrid method for the solution of certain finite difference and finite volume schemes for elliptic PDEs is introduced. A parallelizable version of it, suitable for two-level and multi-level analysis, is also defined and serves as a theoretical tool for deriving suitable implementations for the main version. For indefinite equations, this analysis provides a prediction of a suitable mesh size for the coarsest grid used. Numerical experiments show the efficiency of the method for 3-D diffusion problems with discontinuous coefficients and highly indefinite Helmholtz equations. (C) 1998 Elsevier Science B.V. C1 Technion Israel Inst Technol, Dept Comp Sci, IL-32000 Haifa, Israel. RP Los Alamos Natl Lab, MS B-256, Los Alamos, NM 87545 USA. EM yairs@c3serve.c3.lanl.gov NR 26 TC 7 Z9 7 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9274 EI 1873-5460 J9 APPL NUMER MATH JI Appl. Numer. Math. PD MAR PY 1998 VL 26 IS 3 BP 377 EP 398 DI 10.1016/S0168-9274(97)00070-6 PG 22 WC Mathematics, Applied SC Mathematics GA YX682 UT WOS:000072065900007 ER PT J AU Temelkuran, B Ozbay, E Sigalas, M Tuttle, G Soukoulis, CM Ho, KM AF Temelkuran, B Ozbay, E Sigalas, M Tuttle, G Soukoulis, CM Ho, KM TI Reflection properties of metallic photonic crystals SO APPLIED PHYSICS A-MATERIALS SCIENCE & PROCESSING LA English DT Article ID BAND-GAP CAVITY AB We measured reflection-magnitude and reflection-phase properties of metallic photonic crystals. The experimental results are in good agreement with the theoretical calculations. We converted the reflection-phase information to an effective penetration depth of the electromagnetic waves into the photonic crystal. This information was then used to predict resonance frequencies of defect structures. A symmetric resonant cavity was built, and an experimental set-up limited reflection magnitude of 80 dB below the incident signal was observed at resonance frequency. C1 Bilkent Univ, Dept Phys, TR-06533 Ankara, Turkey. Iowa State Univ, Ames Lab, Ames, IA 50011 USA. Iowa State Univ, Microelect Res Ctr, Ames, IA 50011 USA. RP Temelkuran, B (reprint author), Bilkent Univ, Dept Phys, TR-06533 Ankara, Turkey. RI Ozbay, Ekmel/B-9495-2008; Soukoulis, Costas/A-5295-2008 NR 24 TC 17 Z9 17 U1 0 U2 0 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 USA SN 0947-8396 J9 APPL PHYS A-MATER JI Appl. Phys. A-Mater. Sci. Process. PD MAR PY 1998 VL 66 IS 3 BP 363 EP 365 DI 10.1007/s003390050679 PG 3 WC Materials Science, Multidisciplinary; Physics, Applied SC Materials Science; Physics GA ZB170 UT WOS:000072443400019 ER PT J AU Heinrich, AJ Wenderoth, M Rosentreter, MA Engel, K Schneider, MA Ulbrich, RG Weber, ER Uchida, K AF Heinrich, AJ Wenderoth, M Rosentreter, MA Engel, K Schneider, MA Ulbrich, RG Weber, ER Uchida, K TI Ordering in ternary compound semiconductors studied with cross-sectional scanning tunneling microscopy SO APPLIED PHYSICS A-MATERIALS SCIENCE & PROCESSING LA English DT Article; Proceedings Paper CT 9th International Conference on Scanning Tunneling Microscopy/Spectroscopy and Related Techniques CY JUL 20-25, 1997 CL HAMBURG, GERMANY SP Free & Hanseat City Hamburg, German Min Educ Sci Res & Technol, German Sci Fdn, Commiss European Communities, Oxford Instruments GmbH, Omicron Vakuumphys GmbH, Topometrix GmbH, Digital Instruments ID ALLOYS; HETEROSTRUCTURES; SPECTROSCOPY; EPITAXY; SURFACE AB We present atomically resolved, cross-sectional scanning tunneling microscopy images of Al0.2Ga0.8As and Ga0.5In0.5P layers grown by metal organic vapor phase epitaxy. On the AlGaAs layers, we have found large homogeneous areas with typical diameters of 2-5 nm that have a low Al concentration. These areas are surrounded by dipole-like pairs of enhanced and depressed As atoms. We have also found extended Al-related defects along the [1 (1) over bar 2] and [(1) over bar 12] directions and propose a model structure containing small platelets of AlAs on {111} planes. On the GaInP2 layers, with ordering parameter of gamma = 0.42, we have been able to image the natural superlattice on the atomic scale in filled-state images as alternating enhanced and depressed P rows. In addition, we have found a long-period modulation induced by electronic contrasts, with a typical wavelength of about 4 nm. C1 Univ Gottingen, Inst Phys 4, D-37073 Gottingen, Germany. Univ Calif Berkeley, Dept Mat Sci, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. Nippon Sanso Co, Tsukuba Labs, Ibaraki, Osaka 30033, Japan. RP Wenderoth, M (reprint author), Univ Gottingen, Inst Phys 4, D-37073 Gottingen, Germany. RI Schneider, M. Alexander/B-4444-2012; Schneider, M. Alexander/C-6241-2013; Wenderoth, Martin/Q-3966-2016 OI Schneider, M. Alexander/0000-0002-8607-3301; NR 17 TC 4 Z9 4 U1 1 U2 5 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 USA SN 0947-8396 J9 APPL PHYS A-MATER JI Appl. Phys. A-Mater. Sci. Process. PD MAR PY 1998 VL 66 SU S BP S959 EP S962 DI 10.1007/s003390051274 PN 2 PG 4 WC Materials Science, Multidisciplinary; Physics, Applied SC Materials Science; Physics GA 136YR UT WOS:000076887100058 ER PT J AU Espinoza, LH Niemczyk, TM Stallard, BR AF Espinoza, LH Niemczyk, TM Stallard, BR TI Generation of synthetic background spectra by filtering the sample interferogram in FT-IR SO APPLIED SPECTROSCOPY LA English DT Article DE fourier transform infrared spectroscopy; gasphase infrared spectroscopy; background correction; synthetic background ID INFRARED-SPECTROSCOPY AB The calculation of an absorbance spectrum depends on the measurement of a blank, or background spectrum. In many cases, such as the determination of atmospheric constituents with the use of open-path Fourier transform infrared spectroscopy (FT-IR) or the determination of water vapor in a gaseous sample, it is very difficult to obtain a good background spectrum. The difficulty is due to the fact that it is nearly impossible in these situations to measure a spectrum with no analyte features present. We present a method of generating a background spectrum based on filtering the analyte features from the sample spectrum. When the filtering method is used, the accuracy of the results obtained is found to be dependent upon the analyte peak width, peak height, and type of filter employed. Guidelines for the use of this background generation technique for quantitative determinations are presented. C1 Univ New Mexico, Dept Chem, Albuquerque, NM 87131 USA. Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Niemczyk, TM (reprint author), Univ New Mexico, Dept Chem, Albuquerque, NM 87131 USA. NR 8 TC 9 Z9 9 U1 0 U2 0 PU SOC APPLIED SPECTROSCOPY PI FREDERICK PA 201B BROADWAY ST, FREDERICK, MD 21701 USA SN 0003-7028 J9 APPL SPECTROSC JI Appl. Spectrosc. PD MAR PY 1998 VL 52 IS 3 BP 375 EP 379 DI 10.1366/0003702981943554 PG 5 WC Instruments & Instrumentation; Spectroscopy SC Instruments & Instrumentation; Spectroscopy GA ZH219 UT WOS:000073084900011 ER PT J AU Alam, MK Franke, JE Niemczyk, TM Maynard, JD Rohrscheib, MR Robinson, MR Eaton, RP AF Alam, MK Franke, JE Niemczyk, TM Maynard, JD Rohrscheib, MR Robinson, MR Eaton, RP TI Characterization of pH variation in lysed blood by near-infrared spectroscopy SO APPLIED SPECTROSCOPY LA English DT Article DE blood; pH; near-infrared spectroscopy; multivariate calibration; histidine ID HEMOGLOBIN AB Near-infrared spectra (1300-2500 nm) collected from lysed blood solutions were shown to correlate,vith the pH of the solutions measured potentiometrically, Cross-validated partial least-squares (PLS) models were developed from these spectral data, which provided standard error of prediction (SEP) values below 0.05 pH units for a pH range of 1.0 (6.8-7.8). Experiments were designed to eliminate possible correlation between pH and other components in the blood in order to ensure that variations in the spectral data correlated to pH were due to hydrogen ion changes only. Further work was performed to discern the primary source of pH information in the lysed blood spectra by using spectra collected from plasma and histidine solutions, The blood, plasma, and histidine data sets were compared with the use of loading vectors from principal component analysis (PCA). These loading vectors show that variations in the spectra of the titrated amino acid histidine mimic those seen in lysed blood, but not those seen in plasma. These results suggest that histidine residues of hemoglobin are providing the spectral variation necessary for pH modeling in the lysed blood solutions. It is further shown that the observed pa-sensitive histidine bands do not arise from the exchangeable proton on the imidazole ring of histidine; rather they arise from the variation in the C-H bonds of the C2 and/or the C4 carbons of the imidazole ring as they are influenced by the titration of the nitrogen-bound proton of the imidazole ring. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. Rio Grande Med Technol, Albuquerque, NM 87131 USA. Univ New Mexico, Dept Chem, Albuquerque, NM 87131 USA. Univ New Mexico, Sch Med, Albuquerque, NM 87131 USA. RP Alam, MK (reprint author), Sandia Natl Labs, MS 0342, Albuquerque, NM 87185 USA. NR 17 TC 17 Z9 17 U1 0 U2 1 PU SOC APPLIED SPECTROSCOPY PI FREDERICK PA 201B BROADWAY ST, FREDERICK, MD 21701 USA SN 0003-7028 J9 APPL SPECTROSC JI Appl. Spectrosc. PD MAR PY 1998 VL 52 IS 3 BP 393 EP 399 DI 10.1366/0003702981943572 PG 7 WC Instruments & Instrumentation; Spectroscopy SC Instruments & Instrumentation; Spectroscopy GA ZH219 UT WOS:000073084900013 ER PT J AU Tong, W Yeung, ES AF Tong, W Yeung, ES TI Direct visualization of secretion from single bovine adrenal chromaffin cells by laser-induced native fluorescence imaging microscopy SO APPLIED SPECTROSCOPY LA English DT Article DE fluorescence; chromaffin cells; catecholamine; imaging ID MEDULLARY CELLS; CAPILLARY ELECTROPHORESIS; CATECHOLAMINE SECRETION; PATCH-CLAMP; EXOCYTOSIS; GRANULES; RELEASE AB Direct visualization of the secretion process of individual bovine adrenal chromaffin cells was achieved with laser-induced native fluorescence imaging microscopy. By monitoring the native fluorescence of catecholamines excited by the 275 nm laser line with an intensified charge-coupled-device (CCD) camera, we obtained good temporal and spatial resolution simultaneously without using additional fluorescent probes. Large variations were found among individual cells in terms of the amounts of catecholamines secreted and the rates of secretion. Different regions of a cell also behave differently during the secretion process. However, the degree of this local heterogeneity is smaller than in neurons and neuralgia. The influence of deep-ultraviolet (UV) laser excitation on cells is also discussed. This quantitative imaging technique provides a useful noninvasive approach for the study of dynamic cellular changes and the understanding of the molecular mechanisms of secretory processes. C1 Iowa State Univ, US DOE, Ames Lab, Ames, IA 50011 USA. Iowa State Univ, Dept Chem, Ames, IA 50011 USA. RP Yeung, ES (reprint author), Iowa State Univ, US DOE, Ames Lab, Ames, IA 50011 USA. NR 27 TC 8 Z9 9 U1 0 U2 1 PU SOC APPLIED SPECTROSCOPY PI FREDERICK PA 201B BROADWAY ST, FREDERICK, MD 21701 USA SN 0003-7028 J9 APPL SPECTROSC JI Appl. Spectrosc. PD MAR PY 1998 VL 52 IS 3 BP 407 EP 413 DI 10.1366/0003702981943590 PG 7 WC Instruments & Instrumentation; Spectroscopy SC Instruments & Instrumentation; Spectroscopy GA ZH219 UT WOS:000073084900015 ER PT J AU Dybowski, C Smith, ML Hepp, MA Gaffney, EJ Neue, G Perry, DL AF Dybowski, C Smith, ML Hepp, MA Gaffney, EJ Neue, G Perry, DL TI Pb-207 NMR chemical-shift tensors of the lead (II) halides and the lead (II) hydroxyhalides SO APPLIED SPECTROSCOPY LA English DT Article DE NMR; nuclear magnetic resonance; solid state; lead; halide; laurionite ID SPECTRA; NITRATE AB The NMR properties of the solid lead (II) halides and the lead (II) hydroxyhalides are reported. The analysis shows extremely,vide powder patterns in all cases except the lead (II) iodide, The results indicate that one should be able to distinguish the lead (II) halide from the corresponding lead (II) hydroxyhalide in a mixture. C1 Univ Delaware, Dept Chem & Biochem, Newark, DE 19716 USA. Univ Dortmund, D-44221 Dortmund, Germany. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Dybowski, C (reprint author), Univ Delaware, Dept Chem & Biochem, Newark, DE 19716 USA. NR 13 TC 22 Z9 22 U1 2 U2 16 PU SOC APPLIED SPECTROSCOPY PI FREDERICK PA 201B BROADWAY ST, FREDERICK, MD 21701 USA SN 0003-7028 J9 APPL SPECTROSC JI Appl. Spectrosc. PD MAR PY 1998 VL 52 IS 3 BP 426 EP 429 DI 10.1366/0003702981943626 PG 4 WC Instruments & Instrumentation; Spectroscopy SC Instruments & Instrumentation; Spectroscopy GA ZH219 UT WOS:000073084900018 ER PT J AU Richter, BS Stockwell, HG AF Richter, BS Stockwell, HG TI Descriptive study of deaths from cancer associated with residential proximity to the site of underground nuclear detonations SO ARCHIVES OF ENVIRONMENTAL HEALTH LA English DT Article ID FALLOUT AB During the 1960s, two nuclear detonations were exploded in an underground salt dome in Lamar County, Mississippi. Citizens in this rural area expressed concern about excess cancer among the residents as a result of exposure to tritium. Researchers initiated an epidemiologic investigation in response to these concerns. Investigators identified 2 251 deaths, of which 562 (25.7%) were cancer related. Observed cancer rates for the area of Mississippi were no different than those expected for the state as a whole. Investigators found no association between cancer mortality and distance from the center of detonation. C1 US Dept Energy, Off Epidemiol Studies, Germantown, MD 20874 USA. RP Richter, BS (reprint author), US Dept Energy, Off Epidemiol Studies, EH-62,19901 Germantown Rd, Germantown, MD 20874 USA. NR 8 TC 4 Z9 4 U1 0 U2 0 PU HELDREF PUBLICATIONS PI WASHINGTON PA 1319 EIGHTEENTH ST NW, WASHINGTON, DC 20036-1802 USA SN 0003-9896 J9 ARCH ENVIRON HEALTH JI Arch. Environ. Health PD MAR-APR PY 1998 VL 53 IS 2 BP 109 EP 113 PG 5 WC Environmental Sciences; Public, Environmental & Occupational Health SC Environmental Sciences & Ecology; Public, Environmental & Occupational Health GA ZK580 UT WOS:000073339400004 PM 9577933 ER PT J AU Landa, ER Reimnitz, E Beals, DM Pochkowski, JM Winn, WG Rigor, I AF Landa, ER Reimnitz, E Beals, DM Pochkowski, JM Winn, WG Rigor, I TI Transport of Cs-137 and Pu-239,Pu-240 with ice-rafted debris in the Arctic Ocean SO ARCTIC LA English DT Article DE sea ice; ice-rafted debris; radionuclides; cesium-137; plutonium ID FINE-GRAINED SEDIMENT; MARINE SAMPLES; SEA-ICE; PLUTONIUM; RADIONUCLIDES; CESIUM-137; ELEMENTS; ALASKA; PU-239 AB Ice rafting is the dominant mechanism responsible for the transport of fine-grained sediments from coastal zones to the deep Arctic Basin. Therefore, the drift of ice-rafted debris (IRD) could be a significant transport mechanism from the shelf to the deep basin for radionuclides originating from nuclear fuel cycle activities and released to coastal Arctic regions of the former Soviet Union. In this study, 28 samples of IRD collected from the Arctic ice pack during expeditions in 1989-95 were analyzed for Cs-137 by gamma spectrometry and for Pu-239 and Pu-240 by thermal ionization mass spectrometry. Cs-137 concentrations in the IRD ranged from less than 0.2 to 78 Bq . kg(-1) (dry weight basis). The two samples with the highest Cs-137 concentrations were collected in the vicinity of Franz Josef Land, and their backward trajectories suggest origins in the Kara Sea. Among the lowest Cs-137 values are seven measured on sediments entrained on the North American shelf in 1989 and 1995, and sampled on the shelf less than six months later. Concentrations of Pu-239 + Pu-240 ranged from about 0.02 to 1.8 Bq . kg(-1). The two highest values came from samples collected in the central Canada Basin and near Spitsbergen; calculated backward trajectories suggest at least 14 years of circulation in the Canada Basin in the former case, and an origin near Severnaya Zemlya (at the Kara Sea/Laptev Sea boundary) in the latter case. While most of the IRD samples showed Pu-240/Pu-239 ratios near the mean global fallout value of 0.185, five of the samples had lower ratios, in the 0.119 to 0.166 range, indicative of mixtures of Pu from fallout and from the reprocessing of weapons-grade Pu. The backward trajectories of these five samples suggest origins in the Kara Sea or near Severnaya Zemlya. C1 US Geol Survey, Natl Ctr 430, Reston, VA 20192 USA. US Geol Survey, Menlo Park, CA 94025 USA. Westinghouse Savannah River Co, Savannah River Technol Ctr, Environm Technol Sect, Aiken, SC 29808 USA. Univ Washington, Appl Phys Lab, Polar Sci Ctr, Seattle, WA 98105 USA. RP Landa, ER (reprint author), US Geol Survey, Natl Ctr 430, Reston, VA 20192 USA. NR 61 TC 33 Z9 33 U1 1 U2 1 PU ARCTIC INST N AMER PI CALGARY PA UNIV OF CALGARY 2500 UNIVERSITY DRIVE NW 11TH FLOOR LIBRARY TOWER, CALGARY, ALBERTA T2N 1N4, CANADA SN 0004-0843 J9 ARCTIC JI Arctic PD MAR PY 1998 VL 51 IS 1 BP 27 EP 39 PG 13 WC Environmental Sciences; Geography, Physical SC Environmental Sciences & Ecology; Physical Geography GA ZF988 UT WOS:000072953300005 ER PT J AU Barbagallo, CM Levine, GA Blanche, PJ Ishida, BY Krauss, RM AF Barbagallo, CM Levine, GA Blanche, PJ Ishida, BY Krauss, RM TI Influence of apoE content in receptor binding of large, buoyant LDL in subjects with different LDL subclass phenotypes SO ARTERIOSCLEROSIS THROMBOSIS AND VASCULAR BIOLOGY LA English DT Article DE LDL subclass; apoE; receptor binding; fibroblasts ID LOW-DENSITY-LIPOPROTEIN; APOLIPOPROTEIN-E; HEPATIC LIPASE; SUBFRACTIONS; PLASMA; METABOLISM; RISK; MEN; HETEROGENEITY; PATTERNS AB We investigated the influence of apolipoprotein (apo) E-containing particles on LDL receptor binding of large, buoyant LDL subfractions (LDL I) from subjects with predominantly large (phenotype A) and small (phenotype B) LDL particles. Direct binding of human fibroblast LDL receptors was tested at 4 degrees C before and after removal of apoE-containing particles by immunoaffinity chromatography. The binding affinity of total LDL I in phenotype B was greater than that in phenotype A (Kd of 1.83 +/- 0.3 and 3.43 +/- 0.9 nmol/L, respectively, P < .05). LDL I from phenotype B subjects had a higher apoE electrophoresis of apoE-containing LDL I isolated by immunoaffinity revealed a substantially larger peak particle diameter than in apoE-free LDL I, and comparison of LDL I composition before and after immunoaffinity chromatography suggested an increase in triglyceride content of apoE-containing particles. After removal of these particles, there was a greater than twofold reduction in LDL receptor affinity of phenotype B LDL (Kd of 1.83 +/- 0.3 to 3.76 +/- 0.6, P < .01), whereas in phenotype A no change was observed (Kd of 3.43 +/- 0.9 to 3.57 +/- 0.4, respectively). The receptor affinity of apoE-free LDL I from phenotype A and B subjects did not differ. These findings confirm that large, buoyant LDL particles from phenotype B subjects have a higher LDL receptor affinity than does LDL I from phenotype A subjects and suggest that this difference is due to an increased content of large, triglyceride-enriched, apoE-containing lipoproteins. It is possible that the accumulation of these particles reflects abnormalities in the metabolism of remnant lipoproteins that contribute to atherosclerosis risk in phenotype B subjects. C1 Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Div Life Sci, Berkeley, CA 94720 USA. RP Krauss, RM (reprint author), Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Div Life Sci, Room 465,1 Cyclotron Rd, Berkeley, CA 94720 USA. OI Barbagallo, Carlo M./0000-0002-4114-038X FU NHLBI NIH HHS [HL18574] NR 43 TC 7 Z9 7 U1 0 U2 0 PU LIPPINCOTT WILLIAMS & WILKINS PI PHILADELPHIA PA 227 EAST WASHINGTON SQ, PHILADELPHIA, PA 19106 USA SN 1079-5642 J9 ARTERIOSCL THROM VAS JI Arterioscler. Thromb. Vasc. Biol. PD MAR PY 1998 VL 18 IS 3 BP 466 EP 472 PG 7 WC Hematology; Peripheral Vascular Disease SC Hematology; Cardiovascular System & Cardiology GA ZC969 UT WOS:000072637400018 PM 9514416 ER PT J AU Tripp, R AF Tripp, R TI A two-parameter luminosity correction for type Ia supernovae SO ASTRONOMY & ASTROPHYSICS LA English DT Article DE supernovae : general; cosmology : observations; distance scale ID LARGE MAGELLANIC CLOUD; LIGHT CURVES; DISTANCE; RING AB If, in addition to the usual luminosity correction described by the light curve slope parameter b, we introduce a color correction parameter R, then an extraordinarily good fit is realized for all the 29 distant Type Ia supernovae of the recent Calan/Tololo supernova survey. The reduced chi(2) found is much lower than can be expected. All of the intrinsic dispersion is thereby removed from the data sample, leaving perfectly standardized candles insofar as one can measure with present techniques. The best-fit solution has a mysteriously low value for R (referred to the B-band) of about 2 and a value of b approximate to 0.5 which is smaller than previously reported without the color correction. These parameters lead, using pre-Hipparcos distances for Cepheid calibrations, to essentially the same value for the Hubble constant. Our preliminary value, subject to further investigation of Cepheid-calibrated supernovae using this same color correction, is H-o = 60 +/- 6 kms(-1) Mpc(-1). C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Div Phys, Inst Nucl & Particle Astrophys, Berkeley, CA 94720 USA. RP Tripp, R (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Div Phys, Inst Nucl & Particle Astrophys, Berkeley, CA 94720 USA. NR 18 TC 147 Z9 149 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 MAR PY 1998 VL 331 IS 3 BP 815 EP 820 PG 6 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA ZD690 UT WOS:000072713100014 ER PT J AU Gaztanaga, E Bernardeau, F AF Gaztanaga, E Bernardeau, F TI The skewness and kurtosis of the projected density distribution function: validity of perturbation theory SO ASTRONOMY & ASTROPHYSICS LA English DT Article DE cosmic microwave background; dark matter; gravitational lensing; large-scale structure of Universe ID LARGE-SCALE STRUCTURE; APM GALAXY SURVEY; CORRELATION HIERARCHY; STATISTICAL-ANALYSIS; CATALOGS; OBJECTS AB We study the domain of validity of Perturbation Theory (PT), by comparing its predictions for the reduced skewness, s(3), and kurtosis, s(4), Of the projected cosmological density field, with the results of N-body simulations. We investigate models with different linear power spectra and consider as physical applications both angular galaxy catalogues and weak lensing surveys. We first find that the small-angle approximation for the predicted skewness provides a good match to the exact numerical PT results. On the other hand, results from non-linear simulated catalogues agree well with PT results on quasi-linear angular scales, which correspond to scales larger than about 1 deg in the applications we have considered. We also point out that projection effects tend to attenuate the effects of strong non-linearities in the angular skewness and kurtosis. C1 Ctr Etud Saclay, Serv Phys Theor, F-91191 Gif Sur Yvette, France. CSIC, Unidad Nixta, Inst Estudis Espacials Catalunya, E-08034 Barcelona, Spain. NASA, Fermilab Astrophys Ctr, Batavia, IL 60510 USA. RP Bernardeau, F (reprint author), Ctr Etud Saclay, Serv Phys Theor, F-91191 Gif Sur Yvette, France. EM fbernardeau@cea.fr OI Gaztanaga, Enrique/0000-0001-9632-0815 NR 33 TC 38 Z9 38 U1 1 U2 3 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 MAR PY 1998 VL 331 IS 3 BP 829 EP 837 PG 9 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA ZD690 UT WOS:000072713100016 ER PT J AU Kleinman, SJ Nather, RE Winget, DE Clemens, JC Bradley, PA Kanaan, A Provencal, JL Claver, CF Watson, TK Yanagida, K Nitta, A Dixson, JS Wood, MA Grauer, AD Hino, BP Fontaine, G Liebert, J Sullivan, DJ Wickramasinghe, DT Achilleos, N Marar, TMK Seetha, S Ashoka, BN Meistas, E Leibowitz, EM Moskalik, P Krzesinski, J Solheim, JE Bruvold, A O'Donoghue, D Kurtz, DW Warner, B Martinez, P Vauclair, G Dolez, N Chevreton, M Barstow, MA Kepler, SO Giovannini, O Augusteijn, T Hansen, CJ Kawaler, SD AF Kleinman, SJ Nather, RE Winget, DE Clemens, JC Bradley, PA Kanaan, A Provencal, JL Claver, CF Watson, TK Yanagida, K Nitta, A Dixson, JS Wood, MA Grauer, AD Hino, BP Fontaine, G Liebert, J Sullivan, DJ Wickramasinghe, DT Achilleos, N Marar, TMK Seetha, S Ashoka, BN Meistas, E Leibowitz, EM Moskalik, P Krzesinski, J Solheim, JE Bruvold, A O'Donoghue, D Kurtz, DW Warner, B Martinez, P Vauclair, G Dolez, N Chevreton, M Barstow, MA Kepler, SO Giovannini, O Augusteijn, T Hansen, CJ Kawaler, SD TI Understanding the cool DA white dwarf pulsator, G29-38 SO ASTROPHYSICAL JOURNAL LA English DT Article DE stars, individual (G29-38); stars, oscillations; stars, white dwarfs ID WHOLE EARTH TELESCOPE; ASTEROSEISMOLOGY; STARS AB The white dwarfs are promising laboratories for the study of cosmochronology and stellar evolution. Through observations of the pulsating white dwarfs, we can measure their internal structures and compositions, critical to understanding post-main-sequence evolution, along with their cooling rates, which will allow us to calibrate their ages directly. The most important set of white dwarf variables to measure are the oldest of the pulsators, the cool DA variables (DAVs), which have not been explored previously through asteroseismology due to their complexity and instability. Through a time-series photometry data set spanning 10 yr, we explore the pulsation spectrum of the cool DAV, G29 - 38 and find an underlying structure of 19 (not including muitiplet components) normal-mode, probably l = 1 pulsations amidst an abundance of time variability and linear combination modes. Modeling results are incomplete, but we suggest possible starting directions and discuss probable values for the stellar mass and hydrogen layer size. For the first time, we have made sense out of the complicated power spectra of a large-amplitude DA pulsator. We have shown that its seemingly erratic set of observed frequencies can be understood in terms of a recurring set of normal-mode pulsations and their linear combinations. With this result, we have opened the interior secrets of the DAVs to future asteroseismological modeling, thereby joining the rest of the known white dwarf pulsators. C1 New Jersey Inst Technol, Big Bear Solar Observ, Big Bear City, CA 92314 USA. Univ Texas, Dept Astron, Austin, TX 78712 USA. CALTECH, Pasadena, CA 91125 USA. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Univ Fed Rio Grande Sul, Inst Fis, BR-91501970 Porto Alegre, RS, Brazil. Univ Delaware, Dept Phys & Astron, Sharp Lab, Newark, DE 19716 USA. Natl Opt Astron Observ, Tucson, AZ 85726 USA. Iowa State Univ, Dept Phys & Astron, Ames, IA 50211 USA. Florida Inst Technol, Dept Phys & Space Sci, Melbourne, FL 32901 USA. Univ Arkansas, Dept Phys & Astron, Little Rock, AR 72204 USA. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. Univ Montreal, Dept Phys, Montreal, PQ H3C 3J7, Canada. Univ Arizona, Steward Observ, Tucson, AZ 85721 USA. Univ Victoria, Dept Phys, Wellington, New Zealand. Australian Natl Univ, Dept Math, Canberra, ACT, Australia. Indian Space Res Org, Bangalore 560017, Karnataka, India. Inst Theoret Phys & Astron, LT-2600 Vilnius, Lithuania. Tel Aviv Univ, Dept Phys & Astron, IL-69978 Tel Aviv, Israel. Copernicus Astron Ctr, Warsaw, Poland. Cracow Pedagog Univ, Mt Suhora Observ, PL-30084 Krakow, Poland. Univ Tromso, Inst Matemat Realfag, N-9000 Tromso, Norway. Univ Cape Town, Dept Astron, ZA-7700 Rondebosch, Cape Province, South Africa. Observ Midi Pyrenees, F-31400 Toulouse, France. Observ Paris, F-92195 Meudon, France. Univ Leicester, Dept Phys & Astron, Leicester LE1 7RH, Leics, England. European So Observ, Santiago 19, Chile. Univ Colorado, Joint Inst Lab Astrophys, Boulder, CO 80309 USA. RP Kleinman, SJ (reprint author), New Jersey Inst Technol, Big Bear Solar Observ, 40386 N Shore Lane, Big Bear City, CA 92314 USA. RI Achilleos, Nicholas/C-1647-2008; Kepler, S. O. /H-5901-2012; OI Kepler, S. O. /0000-0002-7470-5703; Kawaler, Steven/0000-0002-6536-6367; Achilleos, Nicholas/0000-0002-5886-3509 NR 33 TC 101 Z9 101 U1 1 U2 7 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 MAR 1 PY 1998 VL 495 IS 1 BP 424 EP 434 DI 10.1086/305259 PN 1 PG 11 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA ZA394 UT WOS:000072359100038 ER PT J AU Ferraris, M Marafante, E Dosanjh, M AF Ferraris, M Marafante, E Dosanjh, M TI In vitro studies on the metabolism and toxicity of aflatoxin B-1 in primary cultures of black catfish (Ictalurus melas) hepatocytes SO ATLA-ALTERNATIVES TO LABORATORY ANIMALS LA English DT Article DE aflatoxin B-1 metabolism; black catfish; trout; EROD; microassays ID PRIMARY MONOLAYER-CULTURES; RAT HEPATOCYTES; ENZYME-ACTIVITIES; RAINBOW-TROUT; INDUCTION; VIABILITY; LIVER; ASSAY AB The capacity of a primary hepatocyte culture of black catfish (Ictalurus melas) to metabolise toxic compounds was evaluated by using aflatoxin B-1 (AFB(1)) as a xenobiotic model. Hepatocytes were isolated by a two-step liver perfusion procedure and cultured in a serum-free medium on both porous membranes and 96-well microplates coated with Matrigel(R). A viability of 95-98% was obtained. The ability to maintain cytochrome P450 activities was examined by measuring ethoxyresorufin-O-deethylase and pentoxyresorufin-O-depentylase activities, at various culture times. The cytotoxic effects of AFB(1) on catfish hepatocytes were examined by using a neutral red uptake assay on 96-well microplates. The concentration causing 50% inhibition of uptake (IC50) value was 3 mu M. The AFB(1) metabolites were analysed by HPLC with an ultraviolet diode array and fluorescent detectors. The results obtained show that catfish hepatocytes cultured on Matrigel retain their AFB(1) metabolising activities for at least 6 days after seeding. This comparative study, using primary hepatocytes and isolated microsomes from black catfish, trout and mice, confirms that the observed marked differences in toxic response following exposure to AFB(1) in these species are likely to be related to their various metabolising capacities. C1 Commiss European Communities, Joint Res Ctr, Inst Environm, ECVAM, I-21020 Ispra, VA, Italy. Univ Calif Berkeley, Lawrence Berkeley Labs, Berkeley, CA 94720 USA. RP Ferraris, M (reprint author), Commiss European Communities, Joint Res Ctr, Inst Environm, ECVAM, I-21020 Ispra, VA, Italy. NR 26 TC 7 Z9 7 U1 0 U2 0 PU FRAME PI NOTTINGHAM PA RUSSELL & BURCH HOUSE 96-98 NORTH SHERWOOD ST, NOTTINGHAM, NOTTS, ENGLAND NG1 4EE SN 0261-1929 J9 ATLA-ALTERN LAB ANIM JI ATLA-Altern. Lab. Anim. PD MAR-APR PY 1998 VL 26 IS 2 BP 225 EP 239 PG 15 WC Medicine, Research & Experimental SC Research & Experimental Medicine GA ZL290 UT WOS:000073417800008 PM 26043400 ER PT J AU Lindberg, SE AF Lindberg, SE TI Introduction: The Fourth International Conference on Mercury as a Global Pollutant SO ATMOSPHERIC ENVIRONMENT LA English DT Editorial Material C1 Oak Ridge Natl Lab, Div Environm Sci, Oak Ridge, TN 37831 USA. RP Lindberg, SE (reprint author), Oak Ridge Natl Lab, Div Environm Sci, POB 2008, Oak Ridge, TN 37831 USA. NR 0 TC 6 Z9 7 U1 0 U2 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 1352-2310 J9 ATMOS ENVIRON JI Atmos. Environ. PD MAR PY 1998 VL 32 IS 5 BP 807 EP 808 DI 10.1016/S1352-2310(98)00070-3 PG 2 WC Environmental Sciences; Meteorology & Atmospheric Sciences SC Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences GA ZK565 UT WOS:000073337900001 ER PT J AU Carpi, A Lindberg, SE AF Carpi, A Lindberg, SE TI Application of a Teflon (TM) dynamic flux chamber for quantifying soil mercury flux: Tests and results over background soil SO ATMOSPHERIC ENVIRONMENT LA English DT Article; Proceedings Paper CT 4th International Conference on Mercury as a Global Pollutant CY AUG 04-08, 1996 CL HAMBURG, GERMANY SP Aluminium Co Amer (ALCOA), BSL Olefinverbund GMBH, City Hamburg, Deutsch Forschungsgemeinsch, Elect Power Res Inst, Environm Canada, AES, European Commiss, SM&T, Florida Dept Environm Protect, Frontier Geosci, USA, GKSS Res Ctr, Hlth Canada, MSB, Oak Ridge Natl Lab, US DOE, US EPA, Verein Freunde Forderer GKSS DE emission; dry deposition; trace metals; atmosphere; cycling ID ELEMENTAL MERCURY; HUMIC SUBSTANCES; VAPOR; AIR AB High precision and low blank contamination were achieved with a Teflon(TM) dynamic chamber for measuring soil mercury flux. Using this chamber, background soil mercury flux averaged between 2 and 7 ng m(-2) h(-1) over forest soil, and between 12 and 45 ng m(-2) h(-1) over open field soil. Spatial heterogeneity of soil mercury flux at duplicate plots co-located within 2 m was small but significant, differing by 20-50%. Elevated mercury emission over field soil occurred in the presence of direct sunlight at the open field sites. Solar radiation, soil temperature and soil moisture were all significant factors effecting mercury emission from soil. Solar radiation affected the reduction of naturally occurring, inorganic soil mercury compounds to volatile elemental mercury (Hg-o), we estimate that background soil accounts for the gross emission of similar to 10(9) g yr(-1) of Hg-o to the atmosphere, with approximately two-thirds of this total from sunlight-exposed soil and the remainder from forest and other shaded-soil ecosystems. (C) 1998 Elsevier Science Ltd. All rights reserved. C1 Cornell Univ, Boyce Thompson Inst Plant Res, Field Environm Toxicol, Ithaca, NY 14853 USA. Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Carpi, A (reprint author), Cornell Univ, Boyce Thompson Inst Plant Res, Field Environm Toxicol, Tower Rd, Ithaca, NY 14853 USA. NR 30 TC 182 Z9 199 U1 3 U2 33 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 1352-2310 J9 ATMOS ENVIRON JI Atmos. Environ. PD MAR PY 1998 VL 32 IS 5 BP 873 EP 882 DI 10.1016/S1352-2310(97)00133-7 PG 10 WC Environmental Sciences; Meteorology & Atmospheric Sciences SC Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences GA ZK565 UT WOS:000073337900008 ER PT J AU Lindberg, SE Hanson, PJ Meyers, TP Kim, KH AF Lindberg, SE Hanson, PJ Meyers, TP Kim, KH TI Air/surface exchange of mercury vapor over forests - The need for a reassessment of continental biogenic emissions SO ATMOSPHERIC ENVIRONMENT LA English DT Article; Proceedings Paper CT 4th International Conference on Mercury as a Global Pollutant CY AUG 04-08, 1996 CL HAMBURG, GERMANY SP Aluminium Co Amer (ALCOA), BSL Olefinverbund GMBH, City Hamburg, Deutsch Forschungsgemeinsch, Elect Power Res Inst, Environm Canada, AES, European Commiss, SM&T, Florida Dept Environm Protect, Frontier Geosci, USA, GKSS Res Ctr, Hlth Canada, MSB, Oak Ridge Natl Lab, US DOE, US EPA, Verein Freunde Forderer GKSS DE micrometeorological studies; atmosphere/surface exchange processes; emission; dry deposition; biogeochemical cycling; modeling; trace metals; air toxics; boreal forest; Sweden ID ELEMENTAL MERCURY; VOLATILE MERCURY; SURFACE EXCHANGE; TRACE-METALS; PHASE; SOILS; DEPOSITION; FLUXES; AIR; ATMOSPHERE AB Atmospheric sources are significant in the cycling of Hg in the biosphere, but there are few reliable data on air:surface exchange of Hg in terrestrial systems. We developed a tower-based micrometeorological gradient method for measuring gas-phase Hg(o) fluxes over soils and vegetation. We describe here results of the modified Bowen ratio approach from three separate flux sampling campaigns: over a mature deciduous forest at the Walker Branch Watershed in Tennessee, over a young pine plantation in Tennessee, and over the boreal forest floor at the Lake Gordsjon watershed in Sweden. Our data show that Hg(o) exchange over these surfaces is bidirectional, but is primarily characterized by emissions from plants and soil. Dry deposition (foliar uptake) is less frequent, of generally lower magnitude, and may be enhanced by surface wetness. We measured emissions over tree canopies in Tennessee in the range of similar to 10-300 ng m(-2) h(-1), and over the boreal forest floor in Sweden of similar to 1-4 ng m(-2) h(-1). Fluxes were influenced by temperature, solar radiation, and atmospheric turbulence. The ability of trees to emit Hg from soil pools has now been established. Others have proposed a significant biotic re-emission of Hg(o) from the oceans, and our data provide the first direct evidence of a similar process in terrestrial systems. These data have been combined with results from chamber studies to estimate the overall flux of gas-phase Hg(o) between the atmosphere and terrestrial systems. Transpiration of Hg(o) represents a previously unmeasured mobilization of Hg from the continents to the troposphere. Including this new source term could increase current estimates of so-called natural emissions by over 100%. (C) 1998 Elsevier Science Ltd. All rights reserved. C1 Oak Ridge Natl Lab, Div Environm Sci, Oak Ridge, TN 37831 USA. NOAA, Atmospher Turbulence Diffus Lab, ERL, Oak Ridge, TN USA. Sang Ji Univ, Wonju, South Korea. RP Lindberg, SE (reprint author), Oak Ridge Natl Lab, Div Environm Sci, POB 2008, Oak Ridge, TN 37831 USA. RI Hanson, Paul J./D-8069-2011; Meyers, Tilden/C-6633-2016 OI Hanson, Paul J./0000-0001-7293-3561; NR 52 TC 175 Z9 191 U1 5 U2 41 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 1352-2310 J9 ATMOS ENVIRON JI Atmos. Environ. PD MAR PY 1998 VL 32 IS 5 BP 895 EP 908 DI 10.1016/S1352-2310(97)00173-8 PG 14 WC Environmental Sciences; Meteorology & Atmospheric Sciences SC Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences GA ZK565 UT WOS:000073337900010 ER PT J AU Childs, WJ AF Childs, WJ TI Matrix elements of hyperfine structure operators in the SL and jj representations for the s, P-N, and d(N) configurations and the SL-jj transformation (vol 67, pg 1, 1998) SO ATOMIC DATA AND NUCLEAR DATA TABLES LA English DT Correction C1 Argonne Natl Lab, Div Phys, Argonne, IL 60439 USA. RP Childs, WJ (reprint author), Argonne Natl Lab, Div Phys, Argonne, IL 60439 USA. NR 1 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 0092-640X J9 ATOM DATA NUCL DATA JI Atom. Data Nucl. Data Tables PD MAR PY 1998 VL 68 IS 2 BP 349 EP 349 DI 10.1006/adnd.1998.0778 PG 1 WC Physics, Atomic, Molecular & Chemical; Physics, Nuclear SC Physics GA ZK058 UT WOS:000073280700008 ER PT J AU Verrell, PA Krenz, JD AF Verrell, PA Krenz, JD TI Competition for mates in the mole salamander, Ambystoma talpoideum: Tactics that may maximize male mating success SO BEHAVIOUR LA English DT Article ID COURTSHIP BEHAVIOR; SEXUAL SELECTION; DESMOGNATHUS-OCHROPHAEUS; INTERMALE COMPETITION; STRATEGY; SYSTEMS; ECOLOGY; CHOICE AB The relatively brief mating periods that are typical of mole salamanders (Amphibia: Caudata: Ambystomatidae) have surely selected for males that are efficient in locating and mating with females in the presence of high densities of competitors. We analyzed quantitatively the competitive mating tactics of the mole salamander, Ambystoma talpoideum, in two laboratory studies. First, we observed competitive interactions in encounters staged between two males and a single female. Such interactions were frequent, with males scrambling to interrupt one another's courtship efforts in an apparent attempt to 'steal' inseminations (and, we assume, fertilizations). The competitive behaviour patterns exhibited by male A. talpoideum appear typical of many other ambystomatid salamanders. We then conducted an experiment to determine the influence of a male-biased operational sex ratio on male mating effort (comparing the performance of target males placed with females alone and in the presence of three potential rivals). Contrary to our expectation, target males decreased their mating effort when density was high and the operational sex ratio was male-biased; many simply abandoned any attempt to court and mate. We hypothesize that decreased male mating effort under a currently male-biased operational sex ratio will be favoured if there exist alternative opportunities for relatively competition-free encounters with females. We suggest a method of testing this hypothesis using comparative data. C1 Savannah River Ecol Lab, Aiken, SC 29802 USA. RP Verrell, PA (reprint author), Savannah River Ecol Lab, Drawer E, Aiken, SC 29802 USA. NR 33 TC 19 Z9 21 U1 3 U2 19 PU BRILL ACADEMIC PUBLISHERS PI LEIDEN PA PLANTIJNSTRAAT 2, P O BOX 9000, 2300 PA LEIDEN, NETHERLANDS SN 0005-7959 J9 BEHAVIOUR JI Behaviour PD MAR PY 1998 VL 135 BP 121 EP 138 PN 2 PG 18 WC Behavioral Sciences; Zoology SC Behavioral Sciences; Zoology GA 105JX UT WOS:000075070900002 ER PT J AU Kreevoy, MM Marimanikkuppam, S Young, VG Baran, J Szafran, M Schultz, AJ Trouw, F AF Kreevoy, MM Marimanikkuppam, S Young, VG Baran, J Szafran, M Schultz, AJ Trouw, F TI The proton potential function and dynamics in sodium hydrogen bis(4-nitrophenoxide) dihydrate SO BERICHTE DER BUNSEN-GESELLSCHAFT-PHYSICAL CHEMISTRY CHEMICAL PHYSICS LA English DT Article; Proceedings Paper CT International Autumn Bunsen Discussion Meeting on Hydrogen Transfer - Theory and Experiment CY SEP 10-13, 1997 CL BERLIN, GERMANY SP Deutsch Bunsengesell Physikal Chem, Freie Univ Berlin DE crystal structure; effect of temperature; proton potential; Speakman-Hadzi hydrogen bond; spectroscopy, infrared ID BONDS; VIBRATIONS AB The structure of crystalline sodium hydrogen bis(4-nitrophenoxide) dihydrate (1) has been studied by X-ray diffraction at 105, 173, and 297 K; and by neutron diffraction at 105 K. Vibrational spectra of 1 have been obtained by infrared absorption at temperatures from 14 K to room temperature, and also by inelastic neutron scattering at 15 K. 1 is a Speakman-Hadzi compound, with an O,O distance of 243 pm (neutron diffraction) or 246 pm (X-ray diffraction) at 105 K. This distance increases to 248 pm (X-ray diffraction) at 297 K. The neutron structure suggests that the bridging hydrogen is distributed between two positions, separated by 35 pm, at the lowest temperature. The asymmetric O,H stretching frequency was found by inelastic neutron scattering, using isotopic substitution, at 605 cm(-1). A number of LR fingerprint bands which are separate below 200 K merge between 200 and 250 K, simplifying the appearance of the spectra. Prominent examples occur around 1600 cm(-1) (a) and around 1450 cm(-1) (b). The (a) pair is separated by about 28 cm(-1) and the (b) pair about 20 cm(-1). At low temperature 1 appears to be a mixture of degenerate tautomers. At higher temperature either the proton shift accelerates, adn band averaging occurs, or else the proton is centralized. If the acceleration model is adopted the tautomer lifetime is about 0.5 ps at the convergence temperature, 225 K. Partial or complete centralization may also be responsible for the changes in the IR spectrum. Thermal excitation of one or more low frequency vibrations causes the acceleration and/or centralization. The O,H stretching frequency is too high to be substantially excited at the coalescence temperature, so this cannot be the relevant vibration. The regular increase in the O,O distance with temperature makes it seem unlikely that centralization is the sole cause of the spectral changes. C1 Univ Minnesota, Dept Chem, Minneapolis, MN 55455 USA. Polish Acad Sci, Inst Low Temp & Struct Res, PL-50950 Wroclaw, Poland. Adam Mickiewicz Univ, Fac Chem, PL-60780 Poznan, Poland. Argonne Natl Lab, Div Intense Pulsed Neutron Source, Argonne, IL 60439 USA. RP Kreevoy, MM (reprint author), Univ Minnesota, Dept Chem, 207 Pleasant St SE, Minneapolis, MN 55455 USA. NR 36 TC 14 Z9 14 U1 0 U2 2 PU WILEY-V C H VERLAG GMBH PI BERLIN PA MUHLENSTRASSE 33-34, D-13187 BERLIN, GERMANY SN 0005-9021 J9 BER BUNSEN PHYS CHEM JI Ber. Bunsen-Ges. Phys. Chem. Chem. Phys. PD MAR PY 1998 VL 102 IS 3 BP 370 EP 376 PG 7 WC Chemistry, Physical SC Chemistry GA ZG382 UT WOS:000072996100013 ER PT J AU Machara, NP Goodwin, PM Enderlein, J Semin, DJ Keller, RA AF Machara, NP Goodwin, PM Enderlein, J Semin, DJ Keller, RA TI Efficient detection of single molecules eluting off an optically trapped microsphere SO BIOIMAGING LA English DT Article; Proceedings Paper CT Workshop on Single Molecule Detection - Basics and Applications in Life Sciences CY SEP 24-27, 1997 CL BERLIN-ADLERSHOF, GERMANY DE single molecule detection; laser-induced fluorescence; optical trap ID CONFOCAL FLUORESCENCE MICROSCOPY; LASER-INDUCED FLUORESCENCE; LIQUIDS AB We demonstrate efficient detection of single fluorescent molecules eluting off a polystyrene microsphere optically trapped in a flowing sheath stream. A 1 mu m diameter analyte doped microsphere was positioned similar to 20 mu m upstream of a 16 mu m diameter probe laser without significant degradation of the detection signal-to-noise ratio due to scattered laser light and fluorescence from the microsphere. In comparison to more standard capillary sample introduction, the microsphere causes only small perturbations to the sheath fluid how. The small diameter of the analyte stream eluting from the microsphere results in a greater than 90% detection efficiency for single rhodamine-6G molecules, limited primarily by the photostability of the dye. C1 Univ Calif Los Alamos Natl Lab, Chem Sci & Technol Div, Los Alamos, NM 87545 USA. RP Goodwin, PM (reprint author), Univ Calif Los Alamos Natl Lab, Chem Sci & Technol Div, Mail Stop M888, Los Alamos, NM 87545 USA. NR 30 TC 18 Z9 18 U1 0 U2 0 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0966-9051 J9 BIOIMAGING JI Bioimaging PD MAR PY 1998 VL 6 IS 1 BP 33 EP 42 DI 10.1002/1361-6374(199803)6:1<33::AID-BIO5>3.3.CO;2-A PG 10 WC Biochemical Research Methods; Microscopy SC Biochemistry & Molecular Biology; Microscopy GA ZW385 UT WOS:000074405700005 ER PT J AU Foin, TC Riley, SPD Pawley, AL Ayres, DR Carlsen, TM Hodum, PJ Switzer, PV AF Foin, TC Riley, SPD Pawley, AL Ayres, DR Carlsen, TM Hodum, PJ Switzer, PV TI Improving recovery planning for threatened and endangered species SO BIOSCIENCE LA English DT Article ID ECOSYSTEM MANAGEMENT; ECOLOGICAL-SOCIETY; ACT; AMERICA AB Identifying patterns across species and environments may lead to more effective recovery plans and endangered species management. C1 Univ Calif Davis, Div Environm Studies, Davis, CA 95616 USA. Bodega Marine Lab, Bodega Bay, CA USA. Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. Univ Calif Davis, Dept Anim Sci, Davis, CA 95616 USA. Eastern Illinois Univ, Dept Zool, Charleston, IL 61920 USA. RP Foin, TC (reprint author), Univ Calif Davis, Div Environm Studies, Davis, CA 95616 USA. EM tcfoin@ucdavis.edu; spriley@ucdavis.edu; alpawley@ucdavis.edu; drayres@ucdavis.edu; carlsen1@llnl.gov; pjhodum@ucdavis.edu; cfpvs@eiu.edu NR 24 TC 80 Z9 91 U1 6 U2 27 PU AMER INST BIOLOGICAL SCI PI WASHINGTON PA 1444 EYE ST, NW, STE 200, WASHINGTON, DC 20005 USA SN 0006-3568 J9 BIOSCIENCE JI Bioscience PD MAR PY 1998 VL 48 IS 3 BP 177 EP 184 DI 10.2307/1313263 PG 8 WC Biology SC Life Sciences & Biomedicine - Other Topics GA YY274 UT WOS:000072130700010 ER PT J AU Kim, R Sandler, SJ Goldman, S Yokota, H Clark, AJ Kim, SH AF Kim, R Sandler, SJ Goldman, S Yokota, H Clark, AJ Kim, SH TI Overexpression of archaeal proteins in Escherichia coli SO BIOTECHNOLOGY LETTERS LA English DT Article ID HIGH-LEVEL EXPRESSION; GENES; CODONS; TRANSLATION; RNA AB Six archaeal proteins containing a high number of Escherichia coli rare codons in their genes were not well expressed in E. coli. These genes showed a five to twenty-fold increase in production when expressed in the presence of a plasmid harboring and expressing the argU and ileX genes encoding rare tRNAs(AGA/AGG)(arg) and tRNA(AUA)(ile). C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Dept Biol Struct, Phys Biosci Div, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Mol & Cell Biol, Berkeley, CA 94720 USA. RP Kim, SH (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Dept Biol Struct, Phys Biosci Div, Berkeley, CA 94720 USA. NR 12 TC 127 Z9 130 U1 0 U2 3 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0141-5492 J9 BIOTECHNOL LETT JI Biotechnol. Lett. PD MAR PY 1998 VL 20 IS 3 BP 207 EP 210 DI 10.1023/A:1005305330517 PG 4 WC Biotechnology & Applied Microbiology SC Biotechnology & Applied Microbiology GA ZB491 UT WOS:000072477900001 ER PT J AU Moran, KP Martner, BE Post, MJ Kropfli, RA Welsh, DC Widener, KB AF Moran, KP Martner, BE Post, MJ Kropfli, RA Welsh, DC Widener, KB TI An unattended cloud-profiling radar for use in climate research SO BULLETIN OF THE AMERICAN METEOROLOGICAL SOCIETY LA English DT Article ID DOPPLER RADAR; PARTICLE SIZES; FIRE-II; PRECIPITATION; PARAMETERS; TURBULENCE; ASTEX AB A new millimeter-wave cloud radar (MMCR) has been designed to provide detailed, long-term observations of nonprecipitating and weakly precipitating clouds at Cloud and Radiation Testbed (CART) sites of the Department of Energy's Atmospheric Radiation Measurement (ARM) program. Scientific requirements included excellent sensitivity and vertical resolution to detect weak and thin multiple layers of ice and liquid water clouds over the sites and longterm, unattended operations in remote locales. ln response to these requirements, the innovative radar design features a vertically pointing, single-polarization, Doppler system operating at 35 GHz (K-a band). It uses a low-peak-power transmitter for long-term reliability and high-gain antenna and pulse-compressed waveforms to maximize sensitivity and resolution. The radar uses the same kind of signal processor as that used in commercial wind profilers. The first MMCR began operations at the CART in northern Oklahoma in late 1996 and has operated continuously there for thousands of hours. It routinely provides remarkably detailed images pf the ever-changing cloud structure and kinematics over this densely instrumented site. Examples of the data are presented. The radar measurements will greatly improve quantitative documentation of cloud conditions over the CART sites and will bolster ARM research to understand how clouds impact climate through their effects on radiative transfer. Millimeter-wave radars such as the MMCR also have potential applications in the fields of aviation weather, weather modification, and basic cloud physics research. C1 NOAA, Environm Technol Lab, Boulder, CO 80303 USA. Pacific NW Natl Lab, Richland, WA USA. RP Moran, KP (reprint author), NOAA, Environm Technol Lab, 325 Broadway, Boulder, CO 80303 USA. NR 36 TC 219 Z9 224 U1 3 U2 12 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0003-0007 J9 B AM METEOROL SOC JI Bull. Amer. Meteorol. Soc. PD MAR PY 1998 VL 79 IS 3 BP 443 EP 455 DI 10.1175/1520-0477(1998)079<0443:AUCPRF>2.0.CO;2 PG 13 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA ZE363 UT WOS:000072785100005 ER PT J AU Panofsky, WKH AF Panofsky, WKH TI Mixed message SO BULLETIN OF THE ATOMIC SCIENTISTS LA English DT Editorial Material C1 Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. RP Panofsky, WKH (reprint author), Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. NR 0 TC 1 Z9 1 U1 0 U2 0 PU EDUC FOUNDATION NUCLEAR SCI PI CHICAGO PA 6042 SOUTH KIMBARK, CHICAGO, IL 60637 USA SN 0096-3402 J9 B ATOM SCI JI Bull. Atom. Scient. PD MAR-APR PY 1998 VL 54 IS 2 BP 45 EP 46 PG 2 WC International Relations; Social Issues SC International Relations; Social Issues GA YY538 UT WOS:000072158100015 ER PT J AU Marsh, G AF Marsh, G TI Nuclear power, yes SO BULLETIN OF THE ATOMIC SCIENTISTS LA English DT Editorial Material C1 Argonne Natl Lab, Argonne, IL 60439 USA. RP Marsh, G (reprint author), Argonne Natl Lab, Argonne, IL 60439 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU EDUC FOUNDATION NUCLEAR SCI PI CHICAGO PA 6042 SOUTH KIMBARK, CHICAGO, IL 60637 USA SN 0096-3402 J9 B ATOM SCI JI Bull. Atom. Scient. PD MAR-APR PY 1998 VL 54 IS 2 BP 47 EP 48 PG 2 WC International Relations; Social Issues SC International Relations; Social Issues GA YY538 UT WOS:000072158100017 ER PT J AU Wilson, AK Bhattacharyya, MH Miller, S Mani, A Sacco-Gibson, N AF Wilson, AK Bhattacharyya, MH Miller, S Mani, A Sacco-Gibson, N TI Ovariectomy-induced changes in aged beagles: Histomorphometry of rib cortical bone SO CALCIFIED TISSUE INTERNATIONAL LA English DT Article; Proceedings Paper CT 16th Annual Meeting of the American-Society-for-Bone-and-Mineral-Research CY SEP 09-13, 1994 CL KANSAS CITY, MISSOURI SP Amer Soc Bone & Mineral Res DE cortical bone; dog; histomorphometry; sequential rib biopsies; postmenopausal osteoporosis ID OVARIAN-FUNCTION; DOGS; OOPHORECTOMY; CESSATION; RATS AB Bone loss associated with estrogen depletion is well documented in cancellous bone but less well characterized in cortical bone. The effects of ovariectomy on the aged beagle skeleton were studied by histomorphometric analysis of the cortical bone in sequential rib biopsies. Biopsies were taken from each ovariectomized or sham-operated dog at the time of surgery and at 1, 4, and 8.5 months after surgery. Just prior to each postoperative biopsy, tetracycline, calcein, and xylenol orange, respectively, were administered by a fluorochrome labeling procedure (2d-10d-2d) to provide markers of bone formation. Analysis of sequential rib biopsies provided a means to follow the ovariectomy response over time and to compare each animal against its own baseline. Though ovariectomy did not influence histomorphometric indices at 1 month after surgery, a transient increase in cortical bone formation occurred thereafter, with a sixfold increase over that of sham-operated dogs at 4 months (P < 0.001) and a return to near control levels at 8.5 months. Cortical porosity increased by the fourth month after ovariectomy and remained high at 8.5 months. These data demonstrate for the first time that rib cortical bone is a responsive site for the effects of ovariectomy in aged female dogs. C1 Argonne Natl Lab, Ctr Mechanist Biol & Biotechnol, Argonne, IL 60439 USA. Univ Utah, Div Radiobiol, Salt Lake City, UT 84112 USA. Procter & Gamble Co, Pharmaceut, Cincinnati, OH USA. RP Bhattacharyya, MH (reprint author), Argonne Natl Lab, Ctr Mechanist Biol & Biotechnol, Bldg 202,9700 S Cass Ave, Argonne, IL 60439 USA. FU NIEHS NIH HHS [ES04816] NR 26 TC 18 Z9 18 U1 1 U2 1 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 USA SN 0171-967X J9 CALCIFIED TISSUE INT JI Calcif. Tissue Int. PD MAR PY 1998 VL 62 IS 3 BP 237 EP 243 DI 10.1007/s002239900423 PG 7 WC Endocrinology & Metabolism SC Endocrinology & Metabolism GA YZ408 UT WOS:000072251400010 PM 9501957 ER PT J AU Kurtis, KE Monteiro, PJM Brown, JT Meyer-Ilse, W AF Kurtis, KE Monteiro, PJM Brown, JT Meyer-Ilse, W TI Imaging of ASR gel by soft X-ray microscopy SO CEMENT AND CONCRETE RESEARCH LA English DT Article ID ALKALI-SILICA REACTION; SOLUBILITY; WATER AB The soft x-ray transmission microscope XM-1 was used to examine alkali silicate reaction (ASR) gel morphology in an experimental investigation of the alkali-aggregate reaction (AAR). The XM-1 microscope is operated by the Center for X-ray Optics on beamline 6.1 of the Advanced Light Source, a third generation synchrotron radiation facility operated by the Ernest O. Lawrence Berkeley National Laboratory. The instrument is unique as samples can be observed wet, with high resolution (43 nm), over time, as chemical reactions proceed. Soft x-ray microscopy was used to examine the in situ reaction of ground ASR gel, obtained from a large dam, and solutions of sodium hydroxide, calcium hydroxide, and combined sodium and calcium hydroxide. From this investigation, it appears that ASR gel combines with alkalis present in pore solution to produce a reaction gel capable of swelling, while the reaction of the ASR gel in the presence of calcium hydroxide and no alkalis results in the formation of a structure resembling C-S-H. It is theorized that the formation of C-S-H or a related compound will decrease the degree of swelling that would otherwise result from the formation of an alkali-aggregate reaction product. The C-S-H-like structure may also contribute strength. These hypotheses are currently under investigation. (C) 1998 Elsevier Science Ltd. C1 Univ Calif Berkeley, Dept Civil & Environm Engn, Berkeley, CA 94720 USA. Ernest Orlando Lawrence Berkeley Natl Lab, Ctr Xray Opt, Berkeley, CA 94720 USA. RP Kurtis, KE (reprint author), Univ Calif Berkeley, Dept Civil & Environm Engn, Berkeley, CA 94720 USA. OI Kurtis, Kimberly/0000-0002-1252-7323 NR 18 TC 39 Z9 41 U1 1 U2 7 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0008-8846 J9 CEMENT CONCRETE RES JI Cem. Concr. Res. PD MAR PY 1998 VL 28 IS 3 BP 411 EP 421 DI 10.1016/S0008-8846(97)00274-3 PG 11 WC Construction & Building Technology; Materials Science, Multidisciplinary SC Construction & Building Technology; Materials Science GA ZE356 UT WOS:000072784400011 ER PT J AU Zhong, GM Guiochon, G AF Zhong, GM Guiochon, G TI Steady-state analysis of simulated moving-bed chromatography using the linear, ideal model SO CHEMICAL ENGINEERING SCIENCE LA English DT Article DE simulated moving bed; chromatography; linear chromatography; ideal chromatography; steady state analysis ID COUNTERCURRENT ADSORPTION SYSTEM; SEPARATION PROCESSES; OPERATION; REACTOR AB In a previous publication, an algebraic solution of Simulated Moving-Bed (SMB) chromatography was derived in the linear, ideal case fora binary mixture. This solution predicts the concentration profiles of the two components along the columns and the concentration histories at the raffinate and the extract ports. It shows the asymptotic nature of SMB operations. On the basis of this previous work, we discuss here the steady-state operation of a SMB, the speed at which this state is reached, and the influence of several physical parameters on this speed. A comparison is made between the results obtained with the solution of the ideal model and those derived from the numerical solutions of more realistic, nonideal models. This comparison shows that, in most practical cases, the speed at which the profiles tend toward the steady-state ones is the same with the ideal model and with the nonideal models. Therefore, the results derived here can be applied to practical cases. (C) 1998 Elsevier Science Ltd. All rights reserved. C1 Univ Tennessee, Dept Chem, Knoxville, TN 37996 USA. Oak Ridge Natl Lab, Div Chem & Analyt Sci, Oak Ridge, TN 37831 USA. RP Guiochon, G (reprint author), Univ Tennessee, Dept Chem, 300 S Coll,552 Buehler Hall, Knoxville, TN 37996 USA. NR 17 TC 8 Z9 8 U1 0 U2 4 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0009-2509 J9 CHEM ENG SCI JI Chem. Eng. Sci. PD MAR PY 1998 VL 53 IS 6 BP 1121 EP 1130 DI 10.1016/S0009-2509(97)00401-6 PG 10 WC Engineering, Chemical SC Engineering GA ZL811 UT WOS:000073473900002 ER PT J AU Turesky, RJ Garner, RC Welti, DH Richoz, J Leveson, SH Dingley, KH Turteltaub, KW Fay, LB AF Turesky, RJ Garner, RC Welti, DH Richoz, J Leveson, SH Dingley, KH Turteltaub, KW Fay, LB TI Metabolism of the food-borne mutagen 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline in humans SO CHEMICAL RESEARCH IN TOXICOLOGY LA English DT Article ID HETEROCYCLIC AROMATIC-AMINES; RAT-LIVER MICROSOMES; CARCINOGEN 2-AMINO-3,8-DIMETHYLIMIDAZO<4,5-F>QUINOXALINE; CYTOCHROME P4501A2; COLORECTAL-CANCER; COLON-CANCER; NONHUMAN-PRIMATES; COOKED FOODS; MEAT; RISK AB The metabolism of 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline (MeIQx) was investigated in five human volunteers given a dietary equivalent of C-14-labeled MeIQx. The amount of the dose excreted in urine ranged from 20.2% to 58.6%, with unmetabolized MeIQx accounting for 0.7-2.8% of the dose. Five principal metabolites were detected in urine, and four of the derivatives were characterized by on-line UV spectroscopy and by HPLC-MS following immunoaffinity chromatography. Two metabolites were identified as the phase II conjugates N-2-(3,8-dimethylimidazo[4,5-f]quinoxalin-2-yl)sulfamic acid (MeIQx-N-2-SO3-) and N-2-(beta-1-glucosiduronyl)-2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline (MeIQx-N-2-Gl). Two other metabolites were the cytochrome P450-mediated (P450) oxidation products 2-amino-8(hydroxymethyl)-3-methylimidazo[4,5-f]quinoxaline (8-CH2OH-MeIQx), and N-2-(beta-1-glucosiduronyl)-N-hydroxy-2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline (NOH-MeIQx-N-2-Gl). The latter product is a conjugate of the genotoxic metabolite 2-(hydroxyamino)-3,8-dimethylimidazo[4,5-f]quinoxaline (NHOH-MeIQx). A large interindividual variation was observed in the metabolism and disposition of MeIQx; these four metabolites and unchanged MeIQx combined accounted for 6.3-26.7% of the total dose. The remaining principal metabolite found in all subjects accounted for 7.6-28% of the dose. It has not been previously identified in rodents or nonhuman primates, and its structure remains unknown. P450-mediated ring oxidation of MeIQx at the C-5 position, a major pathway of detoxication in rodents, was not detected in humans. Both 8-CH2OH-MeIQx formation and NHOH-MeIQx formation are catalyzed by P450 1A2 and may be useful biomarkers of P450 1A2 activity in humans. The levels of NHOH-MeIQx-N-2-Gl found in human urine ranged from 1.4% to 10.0% of the dose, which is significantly higher than that formed in rodents and nonhuman primates undergoing cancer bioassays. Thus, bioactivation of MeIQx by P450-mediated N-oxidation is extensive in humans. C1 Nestec Ltd, Nestle Res Ctr, CH-1000 Lausanne 26, Switzerland. Univ York, Jack Birch Unit Environm Carcinogenesis, Dept Biol, York Y01 5DD, N Yorkshire, England. York Dist Hosp, York Y03 7HE, N Yorkshire, England. Univ Calif Lawrence Livermore Natl Lab, Mol & Struct Biol Div, Livermore, CA 94550 USA. Univ Calif Lawrence Livermore Natl Lab, Ctr Accelerator Mass Spectrometry, Livermore, CA 94550 USA. RP Turesky, RJ (reprint author), Nestec Ltd, Nestle Res Ctr, Vers Chez Les Blanc, CH-1000 Lausanne 26, Switzerland. EM Turesky@CHLSNR.NESTRD.CH NR 53 TC 56 Z9 58 U1 1 U2 2 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0893-228X J9 CHEM RES TOXICOL JI Chem. Res. Toxicol. PD MAR PY 1998 VL 11 IS 3 BP 217 EP 225 DI 10.1021/tx9701891 PG 9 WC Chemistry, Medicinal; Chemistry, Multidisciplinary; Toxicology SC Pharmacology & Pharmacy; Chemistry; Toxicology GA ZD197 UT WOS:000072661100009 PM 9544620 ER PT J AU Cleland, WW Andrews, TJ Gutteridge, S Hartman, FC Lorimer, GH AF Cleland, WW Andrews, TJ Gutteridge, S Hartman, FC Lorimer, GH TI Mechanism of Rubisco: The carbamate as general base SO CHEMICAL REVIEWS LA English DT Review ID RIBULOSE-BISPHOSPHATE CARBOXYLASE; SITE-DIRECTED MUTAGENESIS; RUBRUM RIBULOSEBISPHOSPHATE CARBOXYLASE; TRANSITION-STATE ANALOG; BINUCLEAR METAL CENTER; EPSILON-AMINO GROUP; RIBULOSE-1,5-BISPHOSPHATE CARBOXYLASE; CRYSTAL-STRUCTURE; ACTIVE-SITE; RHODOSPIRILLUM-RUBRUM C1 Univ Wisconsin, Inst Enzyme Res, Madison, WI 53705 USA. Australian Natl Univ, Res Sch Biol Sci, Canberra, ACT 2601, Australia. Dupont Co, Dept Cent Res & Dev, Expt Stn, Wilmington, DE 19880 USA. Oak Ridge Natl Lab, Div Life Sci, Prot Engn Program, Oak Ridge, TN 37831 USA. RP Lorimer, GH (reprint author), Univ Maryland, Dept Chem & Biochem, College Pk, MD 20742 USA. EM gl48@umail.umd.edu NR 101 TC 237 Z9 240 U1 7 U2 50 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0009-2665 J9 CHEM REV JI Chem. Rev. PD MAR-APR PY 1998 VL 98 IS 2 BP 549 EP 561 DI 10.1021/cr970010r PG 13 WC Chemistry, Multidisciplinary SC Chemistry GA ZH281 UT WOS:000073091500003 ER PT J AU Alexandrov, S Grigentch, I Vassilevich, D AF Alexandrov, S Grigentch, I Vassilevich, D TI SU(2)-invariant reduction of (3+1)-dimensional Ashtekar gravity SO CLASSICAL AND QUANTUM GRAVITY LA English DT Article ID GENERAL-RELATIVITY; FORMULATION; QUANTIZATION; SPACE AB We consider a spacetime with spatial sections isomorphic to the group manifold of SU(2). Triad and connection fluctuations are assumed to be SU(2) invariant. Thus they form a finite-dimensional phase space. We perform non-perturbative path-integral quantization of the model. Contrary to previous claims, the path integral measure appeared to be non-singular near configurations admitting additional Killing vectors. In this model we are able to calculate the generating functional of Green functions of the reduced phase space variables exactly. C1 St Petersburg State Univ, Dept Theoret Phys, St Petersburg 198904, Russia. Old Dominion Univ, Dept Phys, Norfolk, VA 23529 USA. Jefferson Lab, Newport News, VA 23606 USA. RP Alexandrov, S (reprint author), St Petersburg State Univ, Dept Theoret Phys, St Petersburg 198904, Russia. RI Vassilevich, Dmitri/C-4142-2013 NR 19 TC 6 Z9 6 U1 0 U2 0 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0264-9381 J9 CLASSICAL QUANT GRAV JI Class. Quantum Gravity PD MAR PY 1998 VL 15 IS 3 BP 573 EP 580 DI 10.1088/0264-9381/15/3/009 PG 8 WC Astronomy & Astrophysics; Physics, Multidisciplinary; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA ZD738 UT WOS:000072718500009 ER PT J AU Schefer, RW Goix, PJ AF Schefer, RW Goix, PJ TI Mechanism of flame stabilization in turbulent, lifted-jet flames SO COMBUSTION AND FLAME LA English DT Article ID LAMINAR AB Particle image velocimetry was used to study the velocity field in the stabilization region of lifted, turbulent CH4-jet flames over a range of Reynolds numbers from 7000 to 19,500. Measured velocities at the lame base are considerably below the turbulent flame speeds derived from previous studies and show a dependence on the Reynolds number. The average velocity at the stabilization point is nearly a factor of five below the premixed laminar burning velocity at the lowest Reynolds number and asymptotes to a value about 20% higher as the Reynolds number is increased. Planar images of OH show that the flame zone structure near the stabilization point is also highly dependent on the Reynolds number. Comparison of the present OH images with previous CH, Raman imaging results shows that the flame thickness is determined by the width of the flammable region. At a low Reynolds number, the flame is stabilized near the jet exit where the flammable layer is thin, resulting in a thin flame zone. At an increased Reynolds number, the stabilization point is located farther downstream where the flammable region is wider, resulting in a correspondingly wider flame zone. It is proposed that the lower velocities observed at the flame base are related to thinning of the flame zone at low Reynolds, which results in greater curvature of the flame base. The increased flame curvature effectively defocuses the transport of heat and flame radicals to reactants upstream of the propagating flame front, resulting in reduced burning velocities. The implications of these results for mechanisms controlling turbulent fame stabilization, with an emphasis on the applicability of triple flame concepts to turbulent flows, are discussed. (C) 1998 by The Combustion Institute. C1 Sandia Natl Labs, Combust Res Facil, Livermore, CA 94551 USA. RP Schefer, RW (reprint author), Sandia Natl Labs, Combust Res Facil, Livermore, CA 94551 USA. RI Schefer, Jurg/G-3960-2012 NR 22 TC 84 Z9 88 U1 2 U2 12 PU ELSEVIER SCIENCE INC PI NEW YORK PA 655 AVENUE OF THE AMERICAS, NEW YORK, NY 10010 USA SN 0010-2180 J9 COMBUST FLAME JI Combust. Flame PD MAR PY 1998 VL 112 IS 4 BP 559 EP 574 DI 10.1016/S0010-2180(97)00130-2 PG 18 WC Thermodynamics; Energy & Fuels; Engineering, Multidisciplinary; Engineering, Chemical; Engineering, Mechanical SC Thermodynamics; Energy & Fuels; Engineering GA YQ533 UT WOS:000071397300008 ER PT J AU Margolis, SB AF Margolis, SB TI Influence of pressure-driven gas permeation on the quasi-steady burning of porous energetic materials SO COMBUSTION THEORY AND MODELLING LA English DT Article ID 2-PHASE FLOW; DEFLAGRATION AB A theoretical two-phase-how analysis is developed to describe the quasi-steady propagation, across a pressure jump, of a multi-phase deflagration in confined porous energetic materials. The difference, or overpressure, between the upstream (unburned) and downstream (burned) gas pressure leads to a more complex structure than that which is obtained for an unconfined deflagration in which the pressure across the multi-phase flame region is approximately constant. In particular, the structure of such a wave is shown by asymptotic methods to consist of a thin boundary layer characterized by gas permeation into the unburned solid, followed by a liquid-gas dame region, common to both types of problem, in which the melted material is preheated further and ultimately converted to gaseous products. The effect of gas how relative to the condensed material is shown to be significant, both in the porous unburned solid as well as in the exothermic liquid-gas melt layer, and is, in turn, strongly affected by the overpressure. Indeed, all quantities of interest, including the burn temperature, gas velocity and the propagation speed, depend on this pressure difference, leading to a significant enhancement of the burning rate with increasing overpressure. In the limit that the overpressure becomes small, the pressure gradient is insufficient to drive gas produced in the reaction zone in the upstream direction, and all gas flow relative to the condensed material is directed in the downstream direction, as in the case of an unconfined deflagration. The present analysis is particularly applicable to those types of porous energetic solid, such as degraded nitramine propellants that can experience significant gas how in the solid preheat region and which are characterized by the presence of exothermic reactions in a bubbling melt layer at their surfaces. C1 Sandia Natl Labs, Combust Res Facil, Livermore, CA 94551 USA. RP Margolis, SB (reprint author), Sandia Natl Labs, Combust Res Facil, Mail Stop 9052, Livermore, CA 94551 USA. NR 7 TC 15 Z9 17 U1 0 U2 2 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 1364-7830 J9 COMBUST THEOR MODEL JI Combust. Theory Model. PD MAR PY 1998 VL 2 IS 1 BP 95 EP 113 PG 19 WC Thermodynamics; Energy & Fuels; Engineering, Chemical; Mathematics, Interdisciplinary Applications SC Thermodynamics; Energy & Fuels; Engineering; Mathematics GA ZG885 UT WOS:000073049800006 ER PT J AU Lehoucq, RB Gray, SK Zhang, DH Light, JC AF Lehoucq, RB Gray, SK Zhang, DH Light, JC TI Vibrational eigenstates of four-atom molecules: a parallel strategy employing the implicitly restarted Lanczos method SO COMPUTER PHYSICS COMMUNICATIONS LA English DT Article DE iterative methods; Lanczos method; molecular vibrations; parallel computing ID DISCRETE VARIABLE REPRESENTATION; QUANTUM-DYNAMICS; ENERGY-LEVELS; STATES; IMPLEMENTATION; EIGENVALUES; ALGORITHM; MATRICES; MODEL AB We present an approach for determining the vibrational eigenstates of four-atom molecules. The primary representation of the (six-dimensional) eigenstates involves a finite basis or quantum number representation, whereas Hamiltonian matrix-vector products are evaluated with the aid of certain grid or discrete variable representations. This approach leads to computational and memory demands that are within acceptable limits. The implicitly restarted Lanczos method, as implemented in the ARPACK suites of codes, is then applied to determine some of the corresponding vibrational eigenstates. A distributed-memory parallel implementation of the method allows very large symmetric matrix eigenvalue problems on the order of N = 2 x 10(6) - to be tackled. The lowest fifty vibrational states of the HOCO molecule, with zero total angular momentum and even parity, are accurately computed on Argonne National Laboratory's IBM SP computer. (C) 1998 Published by Elsevier Science B.V. C1 Argonne Natl Lab, Div Math & Comp Sci, Argonne, IL 60439 USA. Argonne Natl Lab, Div Chem, Argonne, IL 60439 USA. Univ Chicago, Dept Chem, Chicago, IL 60637 USA. Univ Chicago, James Franck Inst, Chicago, IL 60637 USA. RP Lehoucq, RB (reprint author), Sandia Natl Labs, MS 1110,POB 5800, Albuquerque, NM 87185 USA. EM rlehoucq@cs.sandia.gov NR 39 TC 58 Z9 59 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0010-4655 J9 COMPUT PHYS COMMUN JI Comput. Phys. Commun. PD MAR PY 1998 VL 109 IS 1 BP 15 EP 26 DI 10.1016/S0010-4655(98)00002-2 PG 12 WC Computer Science, Interdisciplinary Applications; Physics, Mathematical SC Computer Science; Physics GA ZD585 UT WOS:000072701300003 ER PT J AU Garrett, BC Lynch, GC Allison, TC Truhlar, DG AF Garrett, BC Lynch, GC Allison, TC Truhlar, DG TI ABCRATE: A program for the calculation of atom-diatom reaction rates SO COMPUTER PHYSICS COMMUNICATIONS LA English DT Article DE chemical reaction rates; kinetics; tunneling; variational transition state theory ID TRANSITION-STATE-THEORY; CHEMICAL-REACTION RATES; MULTIDIMENSIONAL TUNNELING PROBABILITIES; CLASSICAL MECHANICAL THEORY; POTENTIAL-ENERGY SURFACE; QUANTAL RATE CONSTANTS; COLLINEAR REACTIONS; COMPUTER-PROGRAM; QUARTIC ANHARMONICITY; HYDROGEN MOLECULES AB ABCRATE is a computer program for the calculation of atom-diatom chemical reaction rates for systems with collinear-dominated dynamics. The dynamical methods used are conventional or generalized transition state theory (GTST) and multidimensional semiclassical approximations for tunneling and nonclassical reflection. The GTST methods included in this version of the program are the canonical and improved canonical variational transition state theory (VTST) and the canonical unified statistical (CUS) method. Rate constants may be calculated for canonical ensembles or for specific vibrational states of selected modes with translational, rotational, and other vibrational modes treated thermally. The potential energy surface required by the program may be a global or semiglobal analytic function. The reaction path is calculated as the path of steepest descent in mass-scaled coordinates from a collinear saddle point, and vibrations transverse to the reaction path are treated by curvilinear internal coordinates. The vibrational modes are quantized, and anharmonicity may be included by various options, including the WKB approximation for bond stretches and the centrifugal oscillator approximation through quartic terms for the curvilinear bend coordinate. Tunneling probabilities are calculated by a variety of semiclassical methods, in particular zero-curvature tunneling (ZCT), small-curvature tunneling (SCT), large-curvature tunneling (LCT), least-action tunneling (LAT), and the microcanonical optimized multidimensional tunneling (mu LOMT) methods. (C) 1998 Elsevier Science B.V. C1 Pacific NW Natl Lab, Environm Mol Sci Lab, Richland, WA 99352 USA. Univ Minnesota, Dept Chem, Minneapolis, MN 55455 USA. Univ Minnesota, Inst Supercomp, Minneapolis, MN 55455 USA. RP Pacific NW Natl Lab, Environm Mol Sci Lab, 906 Battelle Blvd,Mail Stop K1-96, Richland, WA 99352 USA. RI Garrett, Bruce/F-8516-2011; Truhlar, Donald/G-7076-2015 OI Truhlar, Donald/0000-0002-7742-7294 NR 56 TC 17 Z9 17 U1 2 U2 9 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0010-4655 EI 1879-2944 J9 COMPUT PHYS COMMUN JI Comput. Phys. Commun. PD MAR PY 1998 VL 109 IS 1 BP 47 EP 54 DI 10.1016/S0010-4655(97)00137-9 PG 8 WC Computer Science, Interdisciplinary Applications; Physics, Mathematical SC Computer Science; Physics GA ZD585 UT WOS:000072701300006 ER PT J AU Tuminaro, RS Shadid, JN Hutchinson, SA AF Tuminaro, RS Shadid, JN Hutchinson, SA TI Parallel sparse matrix vector multiply software for matrices with data locality SO CONCURRENCY-PRACTICE AND EXPERIENCE LA English DT Article AB In this paper we describe general software utilities for performing unstructured sparse matrix-vector multiplications on distributed-memory message-passing computers. The matrix-vector multiply comprises an important kernel in the solution of large sparse linear systems by iterative methods. Our focus is to present the data structures and communication parameters required by these utilities for general sparse unstructured matrices with data locality. These types of matrices are commonly produced by finite difference and finite element approximations to systems of partial differential equations. In this discussion we also present representative examples and timings which demonstrate the utility and performance of the software. (C) 1998 John Wiley & Sons, Ltd. C1 Sandia Natl Labs, Appl & Numer Math Dept, Albuquerque, NM 87185 USA. Sandia Natl Labs, Parallel Computat Sci Dept, Albuquerque, NM 87185 USA. NR 16 TC 16 Z9 16 U1 0 U2 1 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 MAR PY 1998 VL 10 IS 3 BP 229 EP 247 DI 10.1002/(SICI)1096-9128(199803)10:3<229::AID-CPE296>3.0.CO;2-I PG 19 WC Computer Science, Software Engineering; Computer Science, Theory & Methods SC Computer Science GA ZK605 UT WOS:000073341900004 ER PT J AU Clement, O Rapko, BM Hay, BP AF Clement, O Rapko, BM Hay, BP TI Structural aspects of metal-amide complexes SO COORDINATION CHEMISTRY REVIEWS LA English DT Review DE amide; metal complex; coordination compound; structure ID MM3 FORCE-FIELD; X-RAY STRUCTURE; CRYSTAL-STRUCTURE; SOLVENT-EXTRACTION; ALIPHATIC AMIDES; CHEMICAL SEPARATIONS; LANTHANIDE COMPLEXES; MOLECULAR-STRUCTURES; TRANSITION-METAL; LIGANDS AB An exhaustive survey of crystal structure data on simple amides and metal complexes containing monodentate amide ligands has been performed. Statistical analysis of structural features are reported as a function of the degree of alkylation of the amide functional group, the type of metal ion in the amide complex, and the type of binding to the metal ion. Average values are reported for bond lengths, bond angles, and torsional angles. Orientational preferences of the coordinated amide ligand are discussed in terms of M-O-C bond angles and M-O-C-N torsion angles. (C) 1998 Elsevier Science S.A. C1 Pacific NW Natl Lab, Environm Mol Sci Lab, Richmond, WA 99352 USA. RP Hay, BP (reprint author), Pacific NW Natl Lab, Environm Mol Sci Lab, POB 999, Richmond, WA 99352 USA. EM ben.hay@pnl.gov NR 102 TC 97 Z9 99 U1 3 U2 21 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0010-8545 J9 COORDIN CHEM REV JI Coord. Chem. Rev. PD MAR PY 1998 VL 170 BP 203 EP 243 DI 10.1016/S0010-8545(98)00066-6 PG 41 WC Chemistry, Inorganic & Nuclear SC Chemistry GA ZX303 UT WOS:000074501900008 ER PT J AU Sailer, BL Valdez, JG Steinkamp, JA Crissman, HA AF Sailer, BL Valdez, JG Steinkamp, JA Crissman, HA TI Apoptosis induced with different cycle-perturbing agents produces differential changes in the fluorescence lifetime of DNA-bound ethidium bromide SO CYTOMETRY LA English DT Article DE apoptosis; flow cytometry; fluorescence lifetime; HL-60 cells; drug/radiation treatments ID PROGRAMMED CELL-DEATH; FLOW-CYTOMETRY; EMISSION-SPECTRUM; CAMPTOTHECIN; PHASE; FLUOROCHROMES; DEGRADATION; INHIBITORS; TENIPOSIDE; CLEAVAGE AB Fluorescence lifetime analysis was used in combination with conventional flow cytometric analysis to monitor changes in residual chromatin in apoptotic HL-60 cell populations following treatment with camptothecin, cycloheximide, genistein, H7, and gamma radiation, Data presented show that all of these metabolic inhibitors, which act through different signaling cascades, produce apoptotic subpopulations with decreased but different lifetimes for DNA-bound ethidium bromide (EB). Additionally,, treatment with certain agents reduced the fluorescence lifetime in the apoptotic cells prior to extensive endonuclease degradation of DNA and the appearance of the typical sub-G(0)/G(1) peak in the DNA histogram, A Lifetime value of 21.15 +/- 0.12 ns was obtained for EB bound to nonapoptotic cells, while values for EB bound to the apoptotic subpopulations following treatment with the different agents were: camptothecin, 19.87 +/- 0.08 ns; cycloheximide, 19.39 +/- 0.02 ns; H7, 19.77 +/- 0.03 ns; genistein, 20.04 +/- 0.04 ns; and gamma radiation, 19.67 +/- 0.03 ns. Traditional methods of analysis, including gel electrophoresis or morphology assessment, revealed no significant differences among apoptotic subpopulations induced by treatment with these agents, Our data suggest that the mode of action of the various agents induces structural changes in chromatin organization that differentially alter accessibility of DNA to endonuclease digestion. Subsequent fluorescence lifetime analysis appears sensitive to the resulting differences in the residual chromatin in apoptotic cells following DNA cleavage, Results presented indicate that lifetime analysis, used in conjunction with conventional flow cytometry, can be useful for early detection of apoptosis-induced chromatic changes and may also potentially provide new information on the effects of different apoptosis-induced agents. (C) 1998 Wiley-Liss, Inc. C1 Univ Calif Los Alamos Natl Lab, Div Life Sci, Los Alamos, NM 87545 USA. RP Crissman, HA (reprint author), Univ Calif Los Alamos Natl Lab, Div Life Sci, LS-4 M888, Los Alamos, NM 87545 USA. FU NCRR NIH HHS [R01 RR07855, R01 RR06758, P41-RR01315] NR 32 TC 17 Z9 17 U1 1 U2 2 PU WILEY-LISS PI NEW YORK PA DIV JOHN WILEY & SONS INC, 605 THIRD AVE, NEW YORK, NY 10158-0012 USA SN 0196-4763 J9 CYTOMETRY JI Cytometry PD MAR 1 PY 1998 VL 31 IS 3 BP 208 EP 216 DI 10.1002/(SICI)1097-0320(19980301)31:3<208::AID-CYTO8>3.0.CO;2-G PG 9 WC Biochemical Research Methods; Cell Biology SC Biochemistry & Molecular Biology; Cell Biology GA ZA901 UT WOS:000072413400008 PM 9515720 ER PT J AU Rose, KA Smith, EP AF Rose, KA Smith, EP TI Statistical assessment of model goodness-of-fit using permutation tests SO ECOLOGICAL MODELLING LA English DT Article DE goodness-of-fit; validation; permutation test; model performance AB Assessing model goodness-of-fit (GOF) to observed data is critical for establishing model credibility and confidence. We propose a new GOF approach based on permutation statistics. The approach is described for a simple, hypothetical example and demonstrated by comparing predictions of winter flounder length distributions from a population model to observed data from the Niantic River. Analyses of three different GOF measures, designed to evaluate the mean, S.D., and distribution of winter flounder lengths, showed that predicted mean lengths were indistinguishable from observed values while predicted S.D, and distributions differed significantly. Two other commonly used GOF approaches (regression and the Reynolds et al. (1981) approach of combining separate statistical tests) were also applied to the winter flounder example to illustrate the their relationship to permutation tests. The advantages of the permutation approach, and possible extensions to handle multiple predicted values, are discussed. (C) 1998 Published by Elsevier Science B.V. All rights reserved. C1 Oak Ridge Natl Lab, Div Environm Sci, Oak Ridge, TN 37831 USA. Virginia Polytech Inst & State Univ, Dept Stat, Blacksburg, VA 24061 USA. RP Smith, EP (reprint author), Oak Ridge Natl Lab, Div Environm Sci, POB 2008, Oak Ridge, TN 37831 USA. EM ikr@ornl.Gov NR 14 TC 8 Z9 8 U1 1 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0304-3800 J9 ECOL MODEL JI Ecol. Model. PD MAR 1 PY 1998 VL 106 IS 2-3 BP 129 EP 139 DI 10.1016/S0304-3800(97)00188-9 PG 11 WC Ecology SC Environmental Sciences & Ecology GA ZG984 UT WOS:000073060200003 ER PT J AU Kieft, TL White, CS Loftin, SR Aguilar, R Craig, JA Skaar, DA AF Kieft, TL White, CS Loftin, SR Aguilar, R Craig, JA Skaar, DA TI Temporal dynamics in soil carbon and nitrogen resources at a grassland-shrubland ecotone SO ECOLOGY LA English DT Article DE Bouteloua eriopoda and gracilis; Chihuahuan Desert; desertification; ecotone; grassland; Larrea tridentata; Long-Term Ecological Research (LTER) site; N mineralization; shrubland; soil microbes; soil respiration; temporal variability ID SEMI-DESERT ECOSYSTEMS; MICROBIAL BIOMASS; METABOLIC QUOTIENT; ORGANIC-CARBON; DESERTIFICATION; MINERALIZATION; PATTERNS; STEPPE; UTAH AB Plant communities of large portions of the southwestern United States have changed from grassland to desert shrubland. Previous studies have demonstrated that soil nutrient resources become spatially more heterogeneous and are redistributed into islands of fertility with the shift in vegetation. The research presented here addressed the question of whether soil resources become more temporally heterogeneous as well as more spatially heterogeneous when grassland undergoes desertification to form shrubland. Within adjacent grassland and creosotebush sites, soil profiles were described at three soil pits, and samples were collected for description of nutrient resources within the profile. Relative abundance of plant cover and bare soil was determined within each site using line transects. Surface samples (0-20 cm depth) of bare soil and soil beneath the canopies of grasses and creosotebush were collected 17 times during 1992-1994. Soil samples were analyzed for moisture, extractable ammonium and nitrate, nitrogen mineralization potential, microbial biomass carbon, total organic carbon, microbial respiration, dehydrogenase activity, the ratio of microbial C to total organic C (C-mic/C-org), and the ratio of microbial respiration to biomass carbon (metabolic quotient). The major differences in the structure of soils between sites were the apparent loss of 3-5 cm depth of sandy surface soil at the creosotebush site and an associated increase in calcium carbonate content at a more shallow depth. Soils under plants at both sites had greater total and available nutrient resources, with higher concentrations under creosotebush than under grasses. Greatest temporal variation in available soil resources was observed in soils under creosotebush. When expressed on the basis of area, available soil resources were higher in the grassland than in the creosotebush shrubland, primarily due to the difference in plant cover (45% in grassland, 8% in creosotebush shrubland). C1 New Mexico Inst Min & Technol, Dept Biol, Socorro, NM 87801 USA. Univ New Mexico, Dept Biol, Albuquerque, NM 87131 USA. Rocky Mt Forest & Range Expt Stn, Albuquerque, NM 87106 USA. Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Kieft, TL (reprint author), New Mexico Inst Min & Technol, Dept Biol, Socorro, NM 87801 USA. NR 39 TC 144 Z9 168 U1 7 U2 46 PU ECOLOGICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE, NW, STE 400, WASHINGTON, DC 20036 USA SN 0012-9658 J9 ECOLOGY JI Ecology PD MAR PY 1998 VL 79 IS 2 BP 671 EP 683 DI 10.2307/176962 PG 13 WC Ecology SC Environmental Sciences & Ecology GA ZA653 UT WOS:000072387600025 ER PT J AU Jones, JB Mulholland, PJ AF Jones, JB Mulholland, PJ TI Carbon dioxide variation in a hardwood forest stream: An integrative measure of whole catchment soil respiration SO ECOSYSTEMS LA English DT Article DE carbon dioxide; ecosystem metabolism; organic matter decomposition; trace gas evasion; catchment scale; Tennessee ID MID-WALES; STEADY-STATE; COMMUNITY RESPIRATION; WATER; CO2; CHEMISTRY; EXCHANGE; LAKES; VARIABILITY; GENERATION AB The concentration of CO2 in stream water is a product of not only instream metabolism but also upland, riparian, and groundwater processes and as such can provide an integrative measure of whole catchment soil respiration. Using a 5-year dataset of pH, alkalinity, Ca2+, and Mg2+ in surface water of the West Fork of Walker Branch in eastern Tennessee in conjunction with a hydrological flowpath chemistry model, we investigated how CO2 concentrations and respiration rates in stream, bedrock, and soil environments vary seasonally and interannually. Dissolved inorganic carbon concentration was highest in summer and autumn (P < 0.05) although the proportion as free CO2 (pCO(2)) did not vary seasonally (P > 0.05). Over the 5 years, pCO(2) was always supersaturated with respect to the atmosphere ranging from 374 to 3626 ppmv (1.0- to 10.1-fold greater than atmospheric equilibrium), and CO, evasion from the stream to the atmosphere ranged from 146 to 353 mmol m(-2) d(-1). Whereas pCO(2) in surface water exhibited little intra-annual or interannual variation, distinct seasonal patterns in soil and bedrock pCO(2) were revealed by the catchment CO2 model. Seasonally, soil pCO(2) increased from a winter low of 8167 ppmv to a summer high of 27,068 ppmv. Driven by the seasonal variation in gas levels, evasion of CO2 from sails to the atmosphere ranged from 83 mmol m(-2) d(-1) in winter to 287 mmol m(-2) d(-1) in summer. The seasonal variation in soil CO2 tracked soil temperature (r(2) = 0.46, P < 0.001) and model-derived estimates of CO2 evasion rate from soils agreed with previously reported fluxes measured using chambers (Pearson correlation coefficient = 0.62, P < 0.05) supporting the model assumptions. Although rates of CO, evasion were similar between the stream and soils, the overall rate of evasion from the channel was only 0.4% of the 70,752 mol/d that evaded from soils due to the vastly different areas of the two subsystems. Our model provides a means to assess whole catchment CO2 dynamics from easily collected and measured stream-water samples and an approach to study catchment scale variation in soil ecosystem respiration. C1 Univ Nevada, Dept Sci Biol, Las Vegas, NV 89154 USA. Oak Ridge Natl Lab, Div Environm Sci, Oak Ridge, TN 37831 USA. RP Jones, JB (reprint author), Univ Nevada, Dept Sci Biol, 4505 Maryland Pkwy, Las Vegas, NV 89154 USA. EM jjones@ccmail.nevada.edu RI Mulholland, Patrick/C-3142-2012 NR 57 TC 88 Z9 94 U1 1 U2 34 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 USA SN 1432-9840 J9 ECOSYSTEMS JI Ecosystems PD MAR-APR PY 1998 VL 1 IS 2 BP 183 EP 196 PG 14 WC Ecology SC Environmental Sciences & Ecology GA 115QM UT WOS:000075676200005 ER PT J AU Ishikawa, M Steinberg, M AF Ishikawa, M Steinberg, M TI MHD power systems for reduction of CO2 emission SO ENERGY CONVERSION AND MANAGEMENT LA English DT Article DE CO2 emission; MHD power system; coal fuel; methanol synthesis AB To reduce the emission of CO2 into the atmosphere, two schemes are proposed. The first one is a coal-fired MHD-steam combined power generation system where coal is burned with oxygen rather than air, the obtained high temperature is utilized for the MHD generator and the CO2 is liquefied and recovered. The cycle efficiency with CO2 recovery is estimated to be 45.3% (HHV). Another scheme is a combination of liquid fuel production and MHD-steam combined system, where the CARNOL processes of methanol production are used to reduce CO2 emission from sectors where collection of CO2 is otherwise impossible, such as highly dispersed heat engines and small scale fuel users. The carbon produced from the CARNOL processes is used as a fuel for the MHD-steam combined cycle, and CO2 is liquefied and recovered. 56.2 kg/sec of methanol is produced while the net power delivered to the grid is 370.7 MW, 42.2 kg/sec of CH4 is consumed. (C) 1997 Elsevier Science Ltd. C1 Kyoto Univ, Dept Elect Engn, Sakyo Ku, Kyoto 60601, Japan. Brookhaven Natl Lab, Upton, NY 11973 USA. RP Ishikawa, M (reprint author), Kyoto Univ, Dept Elect Engn, Sakyo Ku, Kyoto 60601, Japan. NR 17 TC 2 Z9 2 U1 1 U2 4 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0196-8904 J9 ENERG CONVERS MANAGE JI Energy Conv. Manag. PD MAR-APR PY 1998 VL 39 IS 5-6 BP 529 EP 539 DI 10.1016/S0196-8904(97)00049-6 PG 11 WC Thermodynamics; Energy & Fuels; Mechanics SC Thermodynamics; Energy & Fuels; Mechanics GA YR390 UT WOS:000071483500017 ER PT J AU Warzinski, RP Holder, GD AF Warzinski, RP Holder, GD TI Gas clathrate hydrates SO ENERGY & FUELS LA English DT Editorial Material C1 US DOE, Pittsburgh Energy Technol Ctr, Pittsburgh, PA 15236 USA. RP Warzinski, RP (reprint author), Univ Pittsburgh, Sch Engn, Pittsburgh, PA 15261 USA. NR 0 TC 9 Z9 9 U1 1 U2 2 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0887-0624 J9 ENERG FUEL JI Energy Fuels PD MAR-APR PY 1998 VL 12 IS 2 BP 189 EP 190 DI 10.1021/ef980007q PG 2 WC Energy & Fuels; Engineering, Chemical SC Energy & Fuels; Engineering GA ZD102 UT WOS:000072651600001 ER PT J AU Stern, LA Kirby, SH Durham, WB AF Stern, LA Kirby, SH Durham, WB TI Polycrystalline methane hydrate: Synthesis from superheated ice, and low-temperature mechanical properties SO ENERGY & FUELS LA English DT Article; Proceedings Paper CT Division-of-Fuel-Chemistry Symposium on Gas Hydrates at the American-Chemical-Society National Meeting CY 1997 CL SAN FRANCISCO, CALIFORNIA SP Amer Chem Soc, Div Fuel Chem ID WATER ICE; SYSTEM; FLOW AB We describe a new and efficient technique to grow aggregates of pure methane hydrate in quantities suitable for physical and material properties testing. Test specimens were grown under static conditions by combining cold, pressurized CH4 gas with granulated H2O ice, and then warming the reactants to promote the reaction CH4(g) + 6H(2)O(s --> 1) --> CH4 . 6H(2)O (methane hydrate). Hydrate formation evidently occurs at the nascent ice/liquid water interface on ice grain surfaces, and complete reaction was achieved by warming the system above the ice melting point and up to 290 K, at 25-30 MPa, for approximately 8 h. The resulting material is pure, cohesive, polycrystalline methane hydrate with controlled grain size and random orientation. Synthesis conditions placed the H2O ice well above its melting temperature while reaction progressed, yet samples and run records showed no evidence for bulk melting of the unreacted portions of ice grains. Control experiments using Ne, a non-hydrate-forming gas, showed that under otherwise identical conditions, the pressure reduction and latent heat associated with ice melting are easily detectable in our fabrication apparatus. These results suggest that under hydrate-forming conditions, H2O ice can persist metastably to temperatures well above its ordinary melting point while reacting to form hydrate. Direct observations of the hydrate growth process in a small, high-pressure optical cell verified these conclusions and revealed additional details of the hydrate growth process. Methane hydrate samples were then tested in constant-strain-rate deformation experiments at T = 140-200 K, P-c = 50-100 MPa, and (epsilon) over dot 10(-4)-10(-6) s(-1). Measurements in both the brittle and ductile fields showed that methane hydrate has measurably different strength than H2O ice, and work hardens to an unusually high degree compared to other ices as well as to most metals and ceramics at high homologous temperatures. This work hardening may be related to a changing stoichiometry under pressure during plastic deformation; X-ray analyses showed that methane hydrate undergoes a process of solid-state disproportionation or exsolution during deformation at conditions well within its conventional stability field. C1 US Geol Survey, Western Eaertquake Hazards Team, Menlo Park, CA 94025 USA. Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Stern, LA (reprint author), US Geol Survey, Western Eaertquake Hazards Team, MS-977,345 Middlefield Rd, Menlo Park, CA 94025 USA. EM lstern@isdmnl.wr.usgs.gov; skirby@isdmnl.wr.usgs.gov; durham1@llnl.gov NR 28 TC 58 Z9 63 U1 3 U2 22 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0887-0624 J9 ENERG FUEL JI Energy Fuels PD MAR-APR PY 1998 VL 12 IS 2 BP 201 EP 211 DI 10.1021/ef970167m PG 11 WC Energy & Fuels; Engineering, Chemical SC Energy & Fuels; Engineering GA ZD102 UT WOS:000072651600004 ER PT J AU Hagaman, EW Murray, DK Del Cul, GD AF Hagaman, EW Murray, DK Del Cul, GD TI Solid state C-13 and F-19 NMR characterization of fluorinated charcoal SO ENERGY & FUELS LA English DT Article ID X-RAY PHOTOELECTRON; GRAPHITE FLUORIDES; MAGNETIC-RESONANCE; DILUTE SPINS; INTERCALATION; SPECTROSCOPY AB The preparation of CFx by elemental fluorination of charcoal was studied using solid state C-13 and F-19 NMR spectroscopy. F-19-C-13 CP/MAS NMR experiments determine the extent of fluorination vs reaction temperature. Three types of carbon species observed over the temperature range -80 to 350 degrees C were assigned to graphitic carbon (C), CF, and CF2 on the basis of chemical shift. These assignments were confirmed by measurement of cross polarization and dipolar dephasing time constants, T-CF and T-DD, respectively. The fluorinated carbons fully cross-polarize in tenths of milliseconds, while polarization transfer among graphitic carbon is slower and is explained by a two-component model. One component, with T-CF less than 1 ms, is assigned to sp(2) carbons adjacent to fluorinated carbons, viz., interfacial graphitic carbon. The other component, with T-CF on the order of milliseconds, is assigned to more remote carbon species, viz., bulk graphitic carbon. The concentrations of CF and CF2 found in the F-19-C-13 CP/MAS NMR experiments are confirmed by direct measurement of the F-19 NMR spectrum. NMR results are presented along with gravimetric and XPS results to provide new insight into fluorocharcoal structure. An average platelet size of 2-4 nm for the fully fluorinated charcoal is derived from these measurements and is proposed as representative of the graphitic carbon platelet size of the charcoal. The fluorination of charcoal is initiated by addition of fluorine to the surface of platelets. At the lowest fluorination temperature, -80 degrees C, a substance of formula CF0.16 is produced which is diamagnetic, as is CF1.1-1.2, carbon monofluoride, the white end-product from complete fluorination (350 degrees C). The low free electron density in these materials stands in stark contrast to that of the charcoal and CFx samples prepared at intermediate temperatures. C1 Oak Ridge Natl Lab, Div Chem & Analyt Sci, Oak Ridge, TN 37831 USA. Oak Ridge Natl Lab, Div Chem Technol, Oak Ridge, TN 37831 USA. RP Hagaman, EW (reprint author), Oak Ridge Natl Lab, Div Chem & Analyt Sci, POB 2008, Oak Ridge, TN 37831 USA. NR 35 TC 28 Z9 28 U1 0 U2 6 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0887-0624 J9 ENERG FUEL JI Energy Fuels PD MAR-APR PY 1998 VL 12 IS 2 BP 399 EP 408 DI 10.1021/ef970156t PG 10 WC Energy & Fuels; Engineering, Chemical SC Energy & Fuels; Engineering GA ZD102 UT WOS:000072651600031 ER PT J AU Dale, VH King, AW Mann, LK Washington-Allen, RA McCord, RA AF Dale, VH King, AW Mann, LK Washington-Allen, RA McCord, RA TI Assessing land-use impacts on natural resources SO ENVIRONMENTAL MANAGEMENT LA English DT Article DE land management; assessment; habitat characterization; limestone barrens; ecological modeling; geographic information systems ID ECOSYSTEM MANAGEMENT; ECOLOGICAL-SOCIETY; AMERICA AB Much information is available on changes that occur in natural resources from both spatially-explicit data an environmental conditions and models of the interactions of these conditions acid resources with human activities. The strategy for assessing land-use impacts on natural resources developed in this paper provides a framework for using relevant data and models to address questions of how management practices can promote both use and protection of resources. This assessment strategy integrates spatially explicit environmental data using geographic information systems (GIS) with computer models that simulate changes in land cover in response to land-use impacts. The computer models also simulate susceptibility of species to changes in habitat suitability and landscape patterns. The approach is applied to management of limestone barrens on the Oak Ridge Reservation in East Tennessee. Potential limestone barrens habitats are identified by overlaying appropriate soils, geology, slope, and land-use/land-cover conditions. Their validity is tested against known sites containing rare species that occur in these habitats. The location of habitats at risk in the aftermath of human activities is determined by using an available area model that identifies the size and proximity of sites that particular types of species can no longer use as habitat. The resulting risk map can be used in land management planning. The approach uses readily available in situ and remotely sensed data and is applicable to a wide range of locations and land-use scenarios. This approach can be refined based on needs identified by land managers and on the sensitivity of the results to the resolution of available resource information. C1 Oak Ridge Natl Lab, Div Environm Sci, Oak Ridge, TN 37831 USA. RP Dale, VH (reprint author), Oak Ridge Natl Lab, Div Environm Sci, POB 2008, Oak Ridge, TN 37831 USA. RI Dale, Virginia/B-6023-2009; OI McCord, Raymond/0000-0002-9182-4288 NR 42 TC 22 Z9 24 U1 2 U2 7 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 USA SN 0364-152X J9 ENVIRON MANAGE JI Environ. Manage. PD MAR-APR PY 1998 VL 22 IS 2 BP 203 EP 211 DI 10.1007/s002679900097 PG 9 WC Environmental Sciences SC Environmental Sciences & Ecology GA YX163 UT WOS:000072012700005 ER PT J AU McIntosh, MJ Arzoumanidis, GG Brockmeier, FE AF McIntosh, MJ Arzoumanidis, GG Brockmeier, FE TI Recovery of fuels and chemicals through catalytic pyrolysis of plastic wastes SO ENVIRONMENTAL PROGRESS LA English DT Article AB The effects of various promoted and unpromoted mixed oxide catalysts on yields and compositions of liquid organic products as measured in a small laboratory pyrolysis reactor are reported. While such small-scale results do not accurately predict process plant yields, they provide a useful reference in preliminary economic evaluations and in planning larger-scale tests. Therefore, on the basis of laboratory results, a commercial-scale catalytic pyrolysis plant for the production of synthetic crude oil was simulated by using Aspen Plus and the economics were developed. Depending on certain assumptions, such a process could be profitable. To test the possibility of producing chemicals, a separations plant was added. Simulation results again suggested potential economic viability. C1 Argonne Natl Lab, Div Energy Syst, Argonne, IL 60439 USA. RP McIntosh, MJ (reprint author), Argonne Natl Lab, Div Energy Syst, 9700 S Cass Ave, Argonne, IL 60439 USA. NR 10 TC 7 Z9 7 U1 1 U2 13 PU AMER INST CHEMICAL ENGINEERS PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 0278-4491 J9 ENVIRON PROG JI Environ. Prog. PD SPR PY 1998 VL 17 IS 1 BP 19 EP 23 DI 10.1002/ep.670170114 PG 5 WC Engineering, Environmental; Engineering, Chemical; Environmental Sciences SC Engineering; Environmental Sciences & Ecology GA ZP222 UT WOS:000073730200006 ER PT J AU Suter, GW AF Suter, GW TI In defense of ecorisk assessment SO ENVIRONMENTAL SCIENCE & TECHNOLOGY LA English DT Letter C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Suter, GW (reprint author), Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. NR 0 TC 0 Z9 0 U1 0 U2 2 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 MAR 1 PY 1998 VL 32 IS 5 BP 116A EP 117A PG 2 WC Engineering, Environmental; Environmental Sciences SC Engineering; Environmental Sciences & Ecology GA YZ913 UT WOS:000072307100003 PM 21662128 ER PT J AU Zufall, MJ Bergin, MH Davidson, CI AF Zufall, MJ Bergin, MH Davidson, CI TI Effects of non-equilibrium hygroscopic growth of (NH(4))(2)SO(4) on dry deposition to water surfaces SO ENVIRONMENTAL SCIENCE & TECHNOLOGY LA English DT Article ID AEROSOL; PARTICLES; ELEMENTS; SIZE AB Growth of hygroscopic aerosols near water surfaces is believed to enhance dry deposition rates, which are a strong function of particle size. Previous dry deposition models estimate hygroscopic growth by assuming equilibrium between aerosols and water vapor (Williams, R. M. Atmos. Environ. 1982, 16, 1933-1938). A model is presented here that combines the relative humidity profile above water surfaces with hygroscopic growth rates for (NH(4))(2)SO(4), assuming cases for a deliquescing and metastable aerosol. Model results show that particles greater than 0.1 mu m in diameter do not grow to their equilibrium size before depositing to a hypothetical water surface. As a consequence, equilibrium models overpredict the effects of hygroscopic growth on deposition velocities by as much as a factor of 5. In addition, model results suggest a significant difference in the deposition velocities of metastable and deliquescing aerosols. Based on measured (NH(4))(2)SO(4) size distributions, overall deposition velocities calculated from a thermodynamic equilibrium model, a mass transfer limited non-equilibrium model with a deliquescing aerosol, and a mass transfer limited non-equilibrium model with a metastable aerosol are 0.11, 0.055, and 0.040 cm/s, respectively. C1 Carnegie Mellon Univ, Dept Civil & Environm Engn, Pittsburgh, PA 15213 USA. NOAA, Climate Monitoring & Diagnost Lab, Boulder, CO 80303 USA. Brookhaven Natl Lab, Environm Chem Div, Upton, NY 11973 USA. RP Zufall, MJ (reprint author), Carnegie Mellon Univ, Dept Civil & Environm Engn, Pittsburgh, PA 15213 USA. EM mz25@andrew.cmu.edu NR 33 TC 8 Z9 8 U1 0 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 MAR 1 PY 1998 VL 32 IS 5 BP 584 EP 590 DI 10.1021/es970476r PG 7 WC Engineering, Environmental; Environmental Sciences SC Engineering; Environmental Sciences & Ecology GA YZ913 UT WOS:000072307100030 ER PT J AU Lau, LD Rodriguez, R Henery, S Manuel, D Schwendiman, L AF Lau, LD Rodriguez, R Henery, S Manuel, D Schwendiman, L TI Photoreduction of mercuric salt solutions at high pH SO ENVIRONMENTAL SCIENCE & TECHNOLOGY LA English DT Article ID TITANIUM-DIOXIDE; AQUEOUS SUSPENSIONS; ION-EXCHANGE; REMOVAL; WATER; MERCURY(II); WASTE AB Titanium dioxide and a 100 W mercury spotlamp were used to photoreduce 100 ppm Hg aqueous mercuric chloride solutions. The solution's basicity and temperature were varied. Two optimum photoreduction conditions were determined: pH 9, 0 degrees C and pH 11, 40 degrees C. TiO2-assisted photoreduction at these two conditions lowered the concentration of mercury left in the solution to below 200 ppb. Methodology was developed to perform an overall mercury mass balance on the process. The overall mercury balance revealed that more than 97% (average 103% +/- 6%) of the mercury removed from solution was deposited as mercury metal on the surface of the TiO2 for the pH 9, 0 degrees C treatment conditions. This mercury could be driven off the TiO2 surface by heating to 100 degrees C for half of an hour under nitrogen flow. The pH and temperature information under light and dark conditions is consistent with a pH-dependent adsorption of a dissociated mercuric species by hydroxide ions on the TiO2 surface followed by nucleation of the reduced species. The TiO2 assisted photoreduction process shows promise for remediation of mercuric waste below the EPA 200 ppb mercury disposal limit as well as the potential for recycling the mercury and TiO2 catalyst. C1 Idaho State Univ, Dept Chem, Pocatello, ID 83209 USA. Lockheed Martin Idaho Technol Co, Idaho Falls, ID 83415 USA. RP Rodriguez, R (reprint author), Idaho State Univ, Dept Chem, Pocatello, ID 83209 USA. EM rodrrene@cwis.isu.edu NR 17 TC 34 Z9 35 U1 0 U2 13 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 MAR 1 PY 1998 VL 32 IS 5 BP 670 EP 675 DI 10.1021/es9704242 PG 6 WC Engineering, Environmental; Environmental Sciences SC Engineering; Environmental Sciences & Ecology GA YZ913 UT WOS:000072307100043 ER PT J AU Stahl, K Hanson, JC AF Stahl, K Hanson, JC TI An in situ study of the edingtonite dehydration process from x-ray synchrotron powder diffraction SO EUROPEAN JOURNAL OF MINERALOGY LA English DT Article DE situ powder diffraction; X-ray synchrotron radiation; zeolite dehydration; edingtonite AB The dehydration process of the zeolite edingtonite, Ba1.8Ca0.2Al4Si6O20. 8H(2)O, has been studied in situ by X-ray synchrotron radiation powder diffraction. 61 consecutive powder patterns were collected between 310 and 684 K, in steps of 6 K, at 5 minute intervals, and the structures were refined using the Rietveld method. At 310 K the two water sites in edingtonite, OW(1) and OW(2), are both 3/4 occupied. Between 310 and 400 K the occupancy of OW(1) drops smoothly to 1/2. At the same time as the OW(1) expulsion continues, the OW(2) occupancy starts to increase to reach a maximum of 88 % at 450 K. A simple electrostatic model is suggested to explain this behaviour. Between 450 and 600 K, OW(2) shows a regular dehydration behaviour. The remaining water is then rapidly expelled as the water contents drop below one per Ba ion. Finally, as a consequence of an unstable Ba-O coordination, the edingtonite structure breaks down between 660 and 680 K. The framework responds to the dehydration first by a chain rotation and later by an intra-chain folding. Both mechanisms can be related to the electrostatic and spatial needs of the Ba ion. C1 Tech Univ Denmark, Dept Chem, DK-2800 Lyngby, Denmark. Brookhaven Natl Lab, Dept Chem, Upton, NY 11973 USA. RP Stahl, K (reprint author), Tech Univ Denmark, Dept Chem, Bldg 207, DK-2800 Lyngby, Denmark. RI Hanson, jonathan/E-3517-2010; OI Stahl, Kenny/0000-0002-4459-3026 NR 11 TC 16 Z9 16 U1 0 U2 0 PU E SCHWEIZERBART'SCHE VERLAGS PI STUTTGART PA NAEGELE U OBERMILLER JOHANNESSTRASSE 3A, D 70176 STUTTGART, GERMANY SN 0935-1221 J9 EUR J MINERAL JI Eur. J. Mineral. PD MAR-APR PY 1998 VL 10 IS 2 BP 221 EP 228 PG 8 WC Mineralogy SC Mineralogy GA ZE988 UT WOS:000072851600003 ER PT J AU Simpson, J Riley, MA Laird, RW Hartley, DJ Kondev, FG Sweeney, J Wilson, AN Gale, SJ Bentley, MA Bruce, AM Chapman, R Clark, RM Cullen, DM Fallon, P Forsyth, PD Freeman, SJ Jones, PM Lisle, JC Macchiavelli, AO Sharpey-Schafer, JF Smith, AG Smith, JF Thompson, DM AF Simpson, J Riley, MA Laird, RW Hartley, DJ Kondev, FG Sweeney, J Wilson, AN Gale, SJ Bentley, MA Bruce, AM Chapman, R Clark, RM Cullen, DM Fallon, P Forsyth, PD Freeman, SJ Jones, PM Lisle, JC Macchiavelli, AO Sharpey-Schafer, JF Smith, AG Smith, JF Thompson, DM TI High-K quasiparticle structures in Er-159 and Er-160 SO EUROPEAN PHYSICAL JOURNAL A LA English DT Article ID GAMMA-RAY SPECTROSCOPY; RARE-EARTH NUCLEI; HIGH-SPIN; BAND TERMINATION; LINE; 50H; 40H AB A series of nem strongly coupled high-K, multi-quasiparticle structures have been observed in the light erbium transitional nuclei, Er-159 and Er-160. The interpretation of these bands is discussed within the framework of the cranked shell model. These sequences, when taken together with the existing quasiparticle excitations, form a near complete set of long-lying, multi-quasiparticle structures on which a coherent series of aligned angular momentum, band crossing and blocking arguments can be bast d. The measured B(M1)/B(E2) ratios are compared with geometrical calculations to test the proposed configuration assignments. C1 SERC, Daresbury Lab, CCLRC, Warrington WA4 4AD, Cheshire, England. Florida State Univ, Dept Phys, Tallahassee, FL 32306 USA. Univ Manchester, Schuster Lab, Manchester M13 9PL, Lancs, England. Univ Liverpool, Oliver Lodge Lab, Liverpool L69 7ZE, Merseyside, England. Staffordshire Univ, Sch Sci, Stoke On Trent ST4 2DE, Staffs, England. Univ Brighton, Dept Mech & Mfg Engn, Brighton BN2 4GJ, E Sussex, England. Univ Paisley, Dept Phys, Paisley PA1 2BE, Renfrew, Scotland. Univ York, Dept Phys, York YO1 5DD, N Yorkshire, England. Oak Ridge Natl Lab, Div Phys, Oak Ridge, TN 37831 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Nucl Sci, Berkeley, CA 94720 USA. Niels Bohr Inst, Tandem Accelerator Lab, DK-4000 Roskilde, Denmark. RP Simpson, J (reprint author), SERC, Daresbury Lab, CCLRC, Warrington WA4 4AD, Cheshire, England. RI Freeman, Sean/B-1280-2010; OI Freeman, Sean/0000-0001-9773-4921; Bruce, Alison/0000-0003-2871-0517 NR 32 TC 13 Z9 13 U1 0 U2 1 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 USA SN 1434-6001 J9 EUR PHYS J A JI Eur. Phys. J. A PD MAR PY 1998 VL 1 IS 3 BP 267 EP 274 DI 10.1007/s100500050061 PG 8 WC Physics, Nuclear; Physics, Particles & Fields SC Physics GA ZJ575 UT WOS:000073230500008 ER PT J AU Breitweg, J Derrick, M Krakauer, D Magill, S Mikunas, D Musgrave, B Repond, J Stanek, R Talaga, RL Yoshida, R Zhang, H Mattingly, MCK Anselmo, F Antonioli, P Bari, G Basile, M Bellagamba, L Boscherini, D Bruni, A Bruni, G Romeo, GC Castellini, G Cifarelli, L Cindolo, F Contin, A Corradi, M De Pasquale, S Gialas, I Giusti, P Iacobucci, G Laurenti, G Levi, G Margotti, A Massam, T Nania, R Palmonari, F Pesci, A Polini, A Ricci, F Sartorelli, G Garcia, YZ Zichichi, A Amelung, C Bornheim, A Brock, I Coboken, K Crittenden, J Deffner, R Eckert, M Grothe, M Hartmann, H Heinloth, K Heinz, L Hilger, E Jakob, HP Katz, UF Kerger, R Paul, E Pfeiffer, M Rembser, C Stamm, J Wedemeyer, R Wieber, H Bailey, DS Campbell-Robson, S Cottingham, WN Foster, B Hall-Wilton, R Hayes, ME Heath, GP Heath, HF McFall, JD Piccioni, D Roff, DG Tapper, RJ Arneodo, M Ayad, R Capua, M Garfagnini, A Iannotti, L Schioppa, M Susinno, G Kim, JY Lee, JH Lim, IT Pac, MY Caldwell, A Cartiglia, H Jing, Z Liu, W Mellado, B Parsons, JA Ritz, S Sampson, S Sciulli, F Straub, PB Zhu, Q Borzemski, P Chwastowski, J Eskreys, A Figiel, J Klimek, K Przybycien, MB Zawiejski, L Adamczyk, L Bednarek, B Bukowy, M Jelen, K Kisielewska, D Kowalski, T Przybycien, M Rulikowska-Zarebska, ER Suszycki, L Zajac, J Dulinski, Z Kotanski, A Abbiendi, G Bauerdick, LAT Behrens, U Beier, H Bienlein, JK Cases, G Deppe, O Desler, K Drews, G Fricke, U Gilkinson, DJ Glasman, C Gottlicher, P Haas, T Hain, W Hasell, D Johnson, KF Kasemann, M Koch, W Kotz, U Kowalski, H Labs, J Lindemann, L Lohr, B Lowe, M Manczak, O Milewski, J Monteiro, T Ng, JST Notz, D Ohrenberg, K Park, IH Pellegrino, A Pelucchi, F Piotrzkowski, K Roco, M Rohde, M Roldan, J Ryan, JJ Savin, AA Schneekloth, U Selonke, F Surrow, B Tassi, E Voss, T Westphal, D Wolf, G Wollmer, U Youngman, C Zarnecki, AF Zeuner, W Burow, BD Grabosch, HJ Meyer, A Schlenstedt, S Barbagli, G Gallo, E Pelfer, P Maccarrone, G Votano, L Bamberger, A Eisenhardt, S Markun, P Trefzger, T Wolfle, S Bromley, JT Brook, NH Bussey, PJ Doyle, AT Macdonald, N Saxon, DH Sinclair, LE Strickland, E Waugh, R Bohnet, I Gendner, N Holm, U Meyer-Larsen, A Salehi, H Wick, K Gladilin, LK Horstmann, D Kcira, D Klanner, R Lohrmann, E Poelz, G Schott, W Zetsche, F Bacon, TC Butterworth, I Cole, JE Howell, G Hung, BHY Lamberti, L Long, KR Miller, DB Pavel, N Prinias, A Sedgbeer, JK Sideris, D Mallik, U Wang, SM Wu, JT Cloth, P Filges, D Fleck, JI Ishii, T Kuze, M Suzuki, I Tokushuku, K Yamada, S Yamauchi, K Yamazaki, Y Hong, SJ Lee, SB Nam, SW Park, SK Barreiro, F Fernandez, JP Garcia, G Graciani, R Hernandez, JM Hervas, L Labarga, L Martinez, M del Peso, J Puga, J Terron, J de Troconiz, JF Corriveau, F Hanna, DS Hartmann, J Hung, LW Murray, WN Ochs, A Riveline, M Stairs, DG St-Laurent, M Ullmann, R Tsurugai, T Bashkirov, V Dolgoshein, BA Stifutkin, A Bashindzhagyan, GL Ermolov, PF Golubkov, YA Khein, LA Korotkova, NA Korzhavina, IA Kuzmin, VA Lukina, OY Proskuryakov, AS Shcheglova, LM Solomin, AN Zotkin, SA Bokel, C Botje, M Brummer, N Chlebana, F Engelen, J Koffeman, E Kooijman, P van Sighem, A Tiecke, H Tuning, N Verkerke, W Vossebeld, J Vreeswijk, M Wiggers, L de Wolf, E Acosta, D Bylsma, B Durkin, LS Gilmore, J Ginsburg, CM Kim, CL Ling, TY Nylander, P Romanowski, TA Blaikley, HE Cashmore, RJ Cooper-Sarkar, AM Devenish, RCE Edmonds, JK Grosse-Knetter, J Harnew, N Nath, C Noyes, VA Quadt, A Ruske, O Tickner, JR Uijterwaal, H Walczak, R Waters, DS Bertolin, A Brugnera, R Carlin, R Dal Corso, F Dosselli, U Limentani, S Morandin, M Posocco, M Stanco, L Stroili, R Voci, C Bulmahn, J Oh, BY Okrasinski, JR Toothacker, WS Whitmore, JJ Iga, Y D'Agostini, G Marini, G Nigro, A Raso, M Hart, JC McCubbin, NA Shah, TP Epperson, D Heusch, C Rahn, JT Sadrozinski, HFW Seiden, A Wichmann, R Williams, DC Schwarzer, O Walenta, AH Abramowicz, H Briskin, G Dagan, S Kananov, S Levy, A Abe, T Fusayasu, T Inuzuka, H Nagano, K Umemori, K Yamashita, T Hamatsu, R Hirose, T Homma, K Kitamura, S Matsushita, T Cirio, R Costa, M Ferrero, MI Maselli, S Monaco, V Peroni, C Petrucci, MC Ruspa, M Sacchi, R Solano, A Staiano, A Dardo, M Bailey, DC Fagerstroem, CP Galea, R Hartner, GF Joo, KK Levman, GM Martin, JF Orr, RS Polenz, S Sabetfakhri, A Simmons, D Teuscher, RJ Butterworth, JH Catterall, CD Jones, TW Lane, JB Saunders, RL Sutton, MR Wing, M Ciborowski, J Grzelak, G Kasprzak, M Muchorowski, K Nowak, RJ Pawlak, JM Pawlak, R Tymieniecka, T Wroblewski, AK Zakrzewski, JA Adamus, H Coldewey, C Eisenberg, Y Hochman, D Karshon, U Badgett, WF Chapin, D Cross, R Dasu, S Foudas, C Loveless, RJ Mattingly, S Reeder, DD Smith, WH Vaiciulis, A Wodarczyk, H Bhadra, S Frisken, WR Khakzad, M Schmidke, WB AF Breitweg, J Derrick, M Krakauer, D Magill, S Mikunas, D Musgrave, B Repond, J Stanek, R Talaga, RL Yoshida, R Zhang, H Mattingly, MCK Anselmo, F Antonioli, P Bari, G Basile, M Bellagamba, L Boscherini, D Bruni, A Bruni, G Romeo, GC Castellini, G Cifarelli, L Cindolo, F Contin, A Corradi, M De Pasquale, S Gialas, I Giusti, P Iacobucci, G Laurenti, G Levi, G Margotti, A Massam, T Nania, R Palmonari, F Pesci, A Polini, A Ricci, F Sartorelli, G Garcia, YZ Zichichi, A Amelung, C Bornheim, A Brock, I Coboken, K Crittenden, J Deffner, R Eckert, M Grothe, M Hartmann, H Heinloth, K Heinz, L Hilger, E Jakob, HP Katz, UF Kerger, R Paul, E Pfeiffer, M Rembser, C Stamm, J Wedemeyer, R Wieber, H Bailey, DS Campbell-Robson, S Cottingham, WN Foster, B Hall-Wilton, R Hayes, ME Heath, GP Heath, HF McFall, JD Piccioni, D Roff, DG Tapper, RJ Arneodo, M Ayad, R Capua, M Garfagnini, A Iannotti, L Schioppa, M Susinno, G Kim, JY Lee, JH Lim, IT Pac, MY Caldwell, A Cartiglia, H Jing, Z Liu, W Mellado, B Parsons, JA Ritz, S Sampson, S Sciulli, F Straub, PB Zhu, Q Borzemski, P Chwastowski, J Eskreys, A Figiel, J Klimek, K Przybycien, MB Zawiejski, L Adamczyk, L Bednarek, B Bukowy, M Jelen, K Kisielewska, D Kowalski, T Przybycien, M Rulikowska-Zarebska, ER Suszycki, L Zajac, J Dulinski, Z Kotanski, A Abbiendi, G Bauerdick, LAT Behrens, U Beier, H Bienlein, JK Cases, G Deppe, O Desler, K Drews, G Fricke, U Gilkinson, DJ Glasman, C Gottlicher, P Haas, T Hain, W Hasell, D Johnson, KF Kasemann, M Koch, W Kotz, U Kowalski, H Labs, J Lindemann, L Lohr, B Lowe, M Manczak, O Milewski, J Monteiro, T Ng, JST Notz, D Ohrenberg, K Park, IH Pellegrino, A Pelucchi, F Piotrzkowski, K Roco, M Rohde, M Roldan, J Ryan, JJ Savin, AA Schneekloth, U Selonke, F Surrow, B Tassi, E Voss, T Westphal, D Wolf, G Wollmer, U Youngman, C Zarnecki, AF Zeuner, W Burow, BD Grabosch, HJ Meyer, A Schlenstedt, S Barbagli, G Gallo, E Pelfer, P Maccarrone, G Votano, L Bamberger, A Eisenhardt, S Markun, P Trefzger, T Wolfle, S Bromley, JT Brook, NH Bussey, PJ Doyle, AT Macdonald, N Saxon, DH Sinclair, LE Strickland, E Waugh, R Bohnet, I Gendner, N Holm, U Meyer-Larsen, A Salehi, H Wick, K Gladilin, LK Horstmann, D Kcira, D Klanner, R Lohrmann, E Poelz, G Schott, W Zetsche, F Bacon, TC Butterworth, I Cole, JE Howell, G Hung, BHY Lamberti, L Long, KR Miller, DB Pavel, N Prinias, A Sedgbeer, JK Sideris, D Mallik, U Wang, SM Wu, JT Cloth, P Filges, D Fleck, JI Ishii, T Kuze, M Suzuki, I Tokushuku, K Yamada, S Yamauchi, K Yamazaki, Y Hong, SJ Lee, SB Nam, SW Park, SK Barreiro, F Fernandez, JP Garcia, G Graciani, R Hernandez, JM Hervas, L Labarga, L Martinez, M del Peso, J Puga, J Terron, J de Troconiz, JF Corriveau, F Hanna, DS Hartmann, J Hung, LW Murray, WN Ochs, A Riveline, M Stairs, DG St-Laurent, M Ullmann, R Tsurugai, T Bashkirov, V Dolgoshein, BA Stifutkin, A Bashindzhagyan, GL Ermolov, PF Golubkov, YA Khein, LA Korotkova, NA Korzhavina, IA Kuzmin, VA Lukina, OY Proskuryakov, AS Shcheglova, LM Solomin, AN Zotkin, SA Bokel, C Botje, M Brummer, N Chlebana, F Engelen, J Koffeman, E Kooijman, P van Sighem, A Tiecke, H Tuning, N Verkerke, W Vossebeld, J Vreeswijk, M Wiggers, L de Wolf, E Acosta, D Bylsma, B Durkin, LS Gilmore, J Ginsburg, CM Kim, CL Ling, TY Nylander, P Romanowski, TA Blaikley, HE Cashmore, RJ Cooper-Sarkar, AM Devenish, RCE Edmonds, JK Grosse-Knetter, J Harnew, N Nath, C Noyes, VA Quadt, A Ruske, O Tickner, JR Uijterwaal, H Walczak, R Waters, DS Bertolin, A Brugnera, R Carlin, R Dal Corso, F Dosselli, U Limentani, S Morandin, M Posocco, M Stanco, L Stroili, R Voci, C Bulmahn, J Oh, BY Okrasinski, JR Toothacker, WS Whitmore, JJ Iga, Y D'Agostini, G Marini, G Nigro, A Raso, M Hart, JC McCubbin, NA Shah, TP Epperson, D Heusch, C Rahn, JT Sadrozinski, HFW Seiden, A Wichmann, R Williams, DC Schwarzer, O Walenta, AH Abramowicz, H Briskin, G Dagan, S Kananov, S Levy, A Abe, T Fusayasu, T Inuzuka, H Nagano, K Umemori, K Yamashita, T Hamatsu, R Hirose, T Homma, K Kitamura, S Matsushita, T Cirio, R Costa, M Ferrero, MI Maselli, S Monaco, V Peroni, C Petrucci, MC Ruspa, M Sacchi, R Solano, A Staiano, A Dardo, M Bailey, DC Fagerstroem, CP Galea, R Hartner, GF Joo, KK Levman, GM Martin, JF Orr, RS Polenz, S Sabetfakhri, A Simmons, D Teuscher, RJ Butterworth, JH Catterall, CD Jones, TW Lane, JB Saunders, RL Sutton, MR Wing, M Ciborowski, J Grzelak, G Kasprzak, M Muchorowski, K Nowak, RJ Pawlak, JM Pawlak, R Tymieniecka, T Wroblewski, AK Zakrzewski, JA Adamus, H Coldewey, C Eisenberg, Y Hochman, D Karshon, U Badgett, WF Chapin, D Cross, R Dasu, S Foudas, C Loveless, RJ Mattingly, S Reeder, DD Smith, WH Vaiciulis, A Wodarczyk, H Bhadra, S Frisken, WR Khakzad, M Schmidke, WB CA ZEUS Collaboration TI Measurement of jet shapes in photoproduction at HERA SO EUROPEAN PHYSICAL JOURNAL C LA English DT Article ID LUND MONTE-CARLO; CENTRAL TRACKING DETECTOR; ZEUS BARREL CALORIMETER; CROSS-SECTIONS; PARTON DISTRIBUTIONS; HADRON COLLIDERS; HARD SCATTERING; 3-JET EVENTS; E+E-PHYSICS; COLLISIONS AB The shape of jets produced in quasi-real photon-proton collisions at centre-of-mass energies in the range 134-277 GeV has been measured using the hadronic energy flow. The measurement was done with the ZEUS detector at HERA. Jets are identified using a cone algorithm in the eta - phi plane with a cone radius of one unit. Measured jet shapes both in inclusive jet and dijet production with transverse energies E-T(jet) > 14 GeV are presented. The jet shape broadens as the jet pseudorapidity (eta(jet)) increases and narrows as E-T(jet) increases. In dijet photoproduction, the jet shapes have been measured separately for samples dominated by resolved and by direct processes, Leading-logarithm parton-shower Monte Carlo calculations of resolved and direct processes describe well the measured jet shapes except for the inclusive production of jets with high eta(jet) and low E-T(jet). The observed broadening of the jet shape as eta(jet) increases is consistent with the predicted increase in the fraction of final state gluon jets. C1 Argonne Natl Lab, Argonne, IL 60439 USA. Andrews Univ, Berrien Springs, MI 49104 USA. Ist Nazl Fis Nucl, I-40126 Bologna, Italy. Univ Bologna, I-40126 Bologna, Italy. Univ Bonn, Inst Phys, D-5300 Bonn, Germany. Univ Bristol, HH Wills Phys Lab, Bristol BS8 1TL, Avon, England. Univ Calabria, Dept Phys, I-87036 Cosenza, Italy. Ist Nazl Fis Nucl, Cosenza, Italy. Chonnam Natl Univ, Kwangju, South Korea. Columbia Univ, Nevis Labs, Irvington, NY USA. Inst Nucl Phys, Krakow, Poland. Acad Min & Met, Fac Phys & Nucl Techniques, Krakow, Poland. Jagiellonian Univ, Dept Phys, Krakow, Poland. DESY, D-2000 Hamburg, Germany. DESY, IFH Zeuthen, Zeuthen, Germany. Ist Nazl Fis Nucl, I-50125 Florence, Italy. Univ Florence, I-50121 Florence, Italy. Ist Nazl Fis Nucl, Lab Nazl Frascati, I-00044 Frascati, Italy. Univ Freiburg, Fak Phys, D-7800 Freiburg, Germany. Univ Glasgow, Dept Phys & Astron, Glasgow, Lanark, Scotland. Univ Hamburg, Inst Expt Phys 2, Hamburg, Germany. Univ Hamburg, Inst Expt Phys 1, Hamburg, Germany. Imperial Coll London, High Energy Nucl Phys Grp, London, England. Univ Iowa, Dept Phys & Astron, Iowa City, IA 52242 USA. Forschungszentrum Julich, Inst Kernphys, D-5170 Julich, Germany. Natl Lab High Energy Phys, KEK, Inst Particle & Nucl Studies, Tsukuba, Ibaraki 305, Japan. Korea Univ, Seoul 136701, South Korea. Univ Autonoma Madrid, Dept Fis Teor, Madrid, Spain. McGill Univ, Dept Phys, Quebec City, PQ, Canada. Meiji Gakuin Univ, Fac Gen Educ, Yokohama, Kanagawa, Japan. Moscow Engn Phys Inst, Moscow 115409, Russia. Moscow MV Lomonosov State Univ, Inst Nucl Phys, Moscow, Russia. Univ Amsterdam, NL-1012 WX Amsterdam, Netherlands. NIKHEF H, NL-1009 DB Amsterdam, Netherlands. Ohio State Univ, Dept Phys, Columbus, OH 43210 USA. Univ Oxford, Dept Phys, Oxford, England. Univ Padua, Dipartimento Fis, I-35100 Padua, Italy. Ist Nazl Fis Nucl, Padua, Italy. Penn State Univ, Dept Phys, University Pk, PA 16802 USA. Polytech Univ, Sagamihara, Kanagawa, Japan. Univ Roma La Sapienza, Dipartimento Fis, I-00185 Rome, Italy. Ist Nazl Fis Nucl, Rome, Italy. Rutherford Appleton Lab, Didcot OX11 0QX, Oxon, England. Univ Calif Santa Cruz, Santa Cruz, CA 95064 USA. Univ Siegen, Fachbereich Phys, D-5900 Siegen, Germany. Tel Aviv Univ, Raymond & Beverly Sackler Fac Exact Sci, Sch Phys, IL-69978 Tel Aviv, Israel. Univ Tokyo, Dept Phys, Tokyo 113, Japan. Tokyo Metropolitan Univ, Dept Phys, Tokyo, Japan. Ist Nazl Fis Nucl, I-10125 Turin, Italy. Univ Turin, Dipartimento Fis Sperimentale, I-10124 Turin, Italy. Ist Nazl Fis Nucl, Alessandria, Italy. Univ Turin, Fac Sci 2, I-10124 Turin, Italy. Univ Toronto, Dept Phys, Toronto, ON, Canada. UCL, Dept Phys & Astron, London, England. Warsaw Univ, Inst Phys Expt, Warsaw, Poland. Inst Nucl Studies, PL-00681 Warsaw, Poland. Weizmann Inst Sci, Dept Particle Phys, IL-76100 Rehovot, Israel. Univ Wisconsin, Dept Phys, Madison, WI 53706 USA. York Univ, Dept Phys, N York, ON M3J 1P3, Canada. CNR, IROE, I-50127 Florence, Italy. RP Argonne Natl Lab, 9700 S Cass Ave, Argonne, IL 60439 USA. RI Solomin, Anatoly/C-3072-2016; Graciani Diaz, Ricardo/I-5152-2016; Capua, Marcella/A-8549-2015; De Pasquale, Salvatore/B-9165-2008; Wing, Matthew/C-2169-2008; Bashkirov, Vladimir/A-4818-2008; Doyle, Anthony/C-5889-2009; Gladilin, Leonid/B-5226-2011; Morandin, Mauro/A-3308-2016; Golubkov, Yury/E-1643-2012; Proskuryakov, Alexander/J-6166-2012; Katz, Uli/E-1925-2013; Wiggers, Leo/B-5218-2015; Hernandez Calama, Jose Maria/H-9127-2015; Tassi, Enrico/K-3958-2015 OI Graciani Diaz, Ricardo/0000-0001-7166-5198; Castellini, Guido/0000-0002-0177-0643; Capua, Marcella/0000-0002-2443-6525; Martinez Rodriguez, Manel/0000-0002-9763-9155; Chwastowski, Janusz/0000-0002-6190-8376; De Pasquale, Salvatore/0000-0001-9236-0748; Doyle, Anthony/0000-0001-6322-6195; Gladilin, Leonid/0000-0001-9422-8636; Morandin, Mauro/0000-0003-4708-4240; Katz, Uli/0000-0002-7063-4418; Wiggers, Leo/0000-0003-1060-0520; Hernandez Calama, Jose Maria/0000-0001-6436-7547; NR 50 TC 33 Z9 33 U1 0 U2 3 PU SPRINGER PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 1434-6044 EI 1434-6052 J9 EUR PHYS J C JI Eur. 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C PD MAR PY 1998 VL 2 IS 1 BP 61 EP 75 PG 15 WC Physics, Particles & Fields SC Physics GA ZC527 UT WOS:000072589300004 ER PT J AU Breitweg, J Derrick, M Krakauer, D Magill, S Mikunas, D Yoshida, BR Zhang, H Mattingly, MCK Anselmo, F Antonioli, P Bari, G Basile, M Bellagamba, L Boscherini, D Bruni, A Bruni, G Romeo, GC Castellini, G Cifarelli, L Cindolo, F Contin, A Corradi, M De Pasquale, S Gialas, I Giusti, P Iacobucci, G Laurenti, G Levi, G Margotti, A Massam, T Nania, R Palmonari, F Pesci, A Polini, A Ricci, F Sartorelli, G Garcia, YZ Zichichi, A Amelung, C Bornheim, A Brock, I Coboken, K Crittenden, J Deffner, R Eckert, M Grothe, M Hartmann, H Heinloth, K Heinz, L Hilger, E Jakob, HP Katz, UF Kerger, R Paul, E Pfeiffer, M Rembser, C Stamm, J Wedemeyer, R Wieber, H Bailey, DS Campbell-Robson, S Cottingham, WN Foster, B Hall-Wilton, R Hayes, ME Heath, GP Heath, HF McFall, JD Piccioni, D Roff, DG Tapper, RJ Arneodo, M Ayad, R Capua, M Garfagnini, A Iannotti, L Schioppa, M Susinno, G Kim, JY Lee, JH Lim, IT Pac, MY Caldwell, A Cartiglia, N Jing, Z Liu, W Mellado, B Parsons, JA Ritz, S Sampson, S Sciulli, F Straub, PB Zhu, Q Borzemski, P Chwastowski, J Eskreys, A Figiel, J Klimek, K Przybycien, MB Zawiejski, L Adamczyk, L Bednarek, B Bukowy, M Czermak, A Jelen, K Kisielewska, D Kowalski, T Przybycien, M Rulikowska-Zarebska, E Suszycki, L Zajac, J Dulinski, Z Kotanski, A Abbiendi, G Bauerdick, LAT Behrens, U Beier, H Bienlein, JK Cases, G Deppe, O Desler, K Drews, G Fricke, U Gilkinson, DJ Glasman, C Gottlicher, P Haas, T Hain, W Hasell, D Johnson, KF Kasemann, M Koch, W Kotz, U Kowalski, H Labs, J Lindemann, L Lohr, B Lowe, M Manczak, O Milewski, J Monteiro, T Ng, JST Notz, D Ohrenberg, K Park, IH Pellegrino, A Pelucchi, F Piotrzkowski, K Roco, M Rohde, M Roldan, J Ryan, JJ Savin, AA Schneekloth, U Schwarzer, O Selonke, F Surrow, B Tassi, E Voss, T Westphal, D Wolf, G Wollmer, U Youngman, C Zarnecki, AF Zeuner, W Burow, BD Grabosch, HJ Meyer, A Schlenstedt, S Barbagli, G Gallo, E Pelfer, P Maccarrone, G Votano, L Bamberger, A Eisenhardt, S Markun, P Trefzger, T Wolfle, S Bromley, JT Brook, NK Bussey, PJ Doyle, AT Macdonald, N Saxon, DH Sinclair, LE Strickland, E Waugh, R Wilson, AS Bohnet, I Gendner, N Holm, U Meyler-Larsen, A Salehi, H Wick, K Gladilin, LK Horstmann, D Kcira, D Klanner, R Lohrmann, E Poelz, G Schott, W Zetsche, F Bacon, TC Butterworth, I Cole, JE Howell, G Hung, BHY Lamberti, L Long, KR Miller, DB Pavel, N Prinias, A Sedgbeer, JK Sideris, D Walker, R Mallik, U Wang, SM Wu, JT Cloth, P Filges, D Fleck, JI Ishii, T Kuze, M Suzuki, I Tokushuku, K Yamada, S Yamauchi, K Yamazaki, Y Hong, SJ Lee, SB Nam, SW Park, SK Barreiro, F Fernandez, JP Garcia, G Graciani, R Hernandez, JM Hervas, L Labarga, L Martinez, M del Peso, J Puga, J Terron, J de Troconiz, JF Corriveau, F Hanna, DS Hartmann, J Hung, LW Murray, WN Ochs, A Riveline, M Stairs, DG St-Laurent, M Ullmann, R Tsurugai, T Bashkirov, V Dolgoshein, BA Stifutkin, A Bashindzhagyan, GL Ermolov, PF Golubkov, YA Khein, LA Korotkova, NA Korzhavina, IA Kuzmin, VA Lukina, OY Proskuryakov, AS Shcheglova, LM Solomin, AN Zotkin, SA Bokel, C Botje, M Brummer, N Chlebana, F Engelen, J Koffeman, E Kooijman, P van Sighem, A Tiecke, H Tuning, N Verkerke, W Vossebeld, J Vreeswijk, M Wiggers, L de Wolf, E Acosta, D Bylsma, B Durkin, LS Gilmore, J Ginsburg, CM Kim, CL Ling, TY Nylander, P Romanowski, TA Blaikley, HE Cashmore, RJ Cooper-Sarkar, AM Devenish, RCE Edmonds, JK Grosse-Knetter, J Harnew, N Nath, C Noyes, VA Quadt, A Ruske, O Tickner, JR Uijterwaal, H Walczak, R Waters, DS Bertolin, A Brugnera, R Carlin, R Dal Corso, F Dosselli, U Limentani, S Morandin, M Posocco, M Stanco, L Stroili, R Voci, C Bulmahn, J Oh, BY Okrasinski, JR Toothacker, WS Whitmore, JJ Iga, Y D'Agostini, G Marini, G Nigro, A Raso, M Hart, JC McCubbin, NA Shah, TP Epperson, D Heusch, C Rahn, JT Sadrozinski, HFW Seiden, A Wichmann, R Williams, DC Abramowicz, H Briskin, G Dagan, S Kananov, S Levy, A Abe, T Fusayasu, T Inuzuka, M Nagano, K Umemori, K Yamashita, T Hamatsu, R Hirose, T Homma, K Kitamura, S Matsushita, T Cirio, R Costa, M Ferrero, MI Maselli, S Monaco, V Peroni, C Petrucci, MC Ruspa, M Sacchi, R Solano, A Staiano, A Dardo, M Bailey, DC Fagerstroem, CP Galea, R Hartner, GF Joo, KK Levman, GM Martin, JF Orr, RS Polenz, S Sabetfakhri, A Simmons, D Teuscher, RJ Butterworth, JM Catterall, CD Jones, TW Lane, JB Saunders, RL Sutton, MR Wing, M Ciborowski, J Grzelak, G Kasprzak, M Muchorowski, K Nowak, RJ Pawlak, JM Pawlak, R Tymieniecka, T Wroblewski, AK Zakrzewski, JA Adamus, M Coldewey, C Eisenberg, Y Hochman, D Karshon, U Badgett, WF Chapin, D Cross, R Dasu, S Foudas, C Loveless, RJ Mattingly, S Reeder, DD Smith, WH Vaiciulis, A Wodarczyk, M Deshpande, A Dhawan, S Hughes, VW Bhadra, S Frisken, WR Khakzad, M Schmidke, WB AF Breitweg, J Derrick, M Krakauer, D Magill, S Mikunas, D Yoshida, BR Zhang, H Mattingly, MCK Anselmo, F Antonioli, P Bari, G Basile, M Bellagamba, L Boscherini, D Bruni, A Bruni, G Romeo, GC Castellini, G Cifarelli, L Cindolo, F Contin, A Corradi, M De Pasquale, S Gialas, I Giusti, P Iacobucci, G Laurenti, G Levi, G Margotti, A Massam, T Nania, R Palmonari, F Pesci, A Polini, A Ricci, F Sartorelli, G Garcia, YZ Zichichi, A Amelung, C Bornheim, A Brock, I Coboken, K Crittenden, J Deffner, R Eckert, M Grothe, M Hartmann, H Heinloth, K Heinz, L Hilger, E Jakob, HP Katz, UF Kerger, R Paul, E Pfeiffer, M Rembser, C Stamm, J Wedemeyer, R Wieber, H Bailey, DS Campbell-Robson, S Cottingham, WN Foster, B Hall-Wilton, R Hayes, ME Heath, GP Heath, HF McFall, JD Piccioni, D Roff, DG Tapper, RJ Arneodo, M Ayad, R Capua, M Garfagnini, A Iannotti, L Schioppa, M Susinno, G Kim, JY Lee, JH Lim, IT Pac, MY Caldwell, A Cartiglia, N Jing, Z Liu, W Mellado, B Parsons, JA Ritz, S Sampson, S Sciulli, F Straub, PB Zhu, Q Borzemski, P Chwastowski, J Eskreys, A Figiel, J Klimek, K Przybycien, MB Zawiejski, L Adamczyk, L Bednarek, B Bukowy, M Czermak, A Jelen, K Kisielewska, D Kowalski, T Przybycien, M Rulikowska-Zarebska, E Suszycki, L Zajac, J Dulinski, Z Kotanski, A Abbiendi, G Bauerdick, LAT Behrens, U Beier, H Bienlein, JK Cases, G Deppe, O Desler, K Drews, G Fricke, U Gilkinson, DJ Glasman, C Gottlicher, P Haas, T Hain, W Hasell, D Johnson, KF Kasemann, M Koch, W Kotz, U Kowalski, H Labs, J Lindemann, L Lohr, B Lowe, M Manczak, O Milewski, J Monteiro, T Ng, JST Notz, D Ohrenberg, K Park, IH Pellegrino, A Pelucchi, F Piotrzkowski, K Roco, M Rohde, M Roldan, J Ryan, JJ Savin, AA Schneekloth, U Schwarzer, O Selonke, F Surrow, B Tassi, E Voss, T Westphal, D Wolf, G Wollmer, U Youngman, C Zarnecki, AF Zeuner, W Burow, BD Grabosch, HJ Meyer, A Schlenstedt, S Barbagli, G Gallo, E Pelfer, P Maccarrone, G Votano, L Bamberger, A Eisenhardt, S Markun, P Trefzger, T Wolfle, S Bromley, JT Brook, NK Bussey, PJ Doyle, AT Macdonald, N Saxon, DH Sinclair, LE Strickland, E Waugh, R Wilson, AS Bohnet, I Gendner, N Holm, U Meyler-Larsen, A Salehi, H Wick, K Gladilin, LK Horstmann, D Kcira, D Klanner, R Lohrmann, E Poelz, G Schott, W Zetsche, F Bacon, TC Butterworth, I Cole, JE Howell, G Hung, BHY Lamberti, L Long, KR Miller, DB Pavel, N Prinias, A Sedgbeer, JK Sideris, D Walker, R Mallik, U Wang, SM Wu, JT Cloth, P Filges, D Fleck, JI Ishii, T Kuze, M Suzuki, I Tokushuku, K Yamada, S Yamauchi, K Yamazaki, Y Hong, SJ Lee, SB Nam, SW Park, SK Barreiro, F Fernandez, JP Garcia, G Graciani, R Hernandez, JM Hervas, L Labarga, L Martinez, M del Peso, J Puga, J Terron, J de Troconiz, JF Corriveau, F Hanna, DS Hartmann, J Hung, LW Murray, WN Ochs, A Riveline, M Stairs, DG St-Laurent, M Ullmann, R Tsurugai, T Bashkirov, V Dolgoshein, BA Stifutkin, A Bashindzhagyan, GL Ermolov, PF Golubkov, YA Khein, LA Korotkova, NA Korzhavina, IA Kuzmin, VA Lukina, OY Proskuryakov, AS Shcheglova, LM Solomin, AN Zotkin, SA Bokel, C Botje, M Brummer, N Chlebana, F Engelen, J Koffeman, E Kooijman, P van Sighem, A Tiecke, H Tuning, N Verkerke, W Vossebeld, J Vreeswijk, M Wiggers, L de Wolf, E Acosta, D Bylsma, B Durkin, LS Gilmore, J Ginsburg, CM Kim, CL Ling, TY Nylander, P Romanowski, TA Blaikley, HE Cashmore, RJ Cooper-Sarkar, AM Devenish, RCE Edmonds, JK Grosse-Knetter, J Harnew, N Nath, C Noyes, VA Quadt, A Ruske, O Tickner, JR Uijterwaal, H Walczak, R Waters, DS Bertolin, A Brugnera, R Carlin, R Dal Corso, F Dosselli, U Limentani, S Morandin, M Posocco, M Stanco, L Stroili, R Voci, C Bulmahn, J Oh, BY Okrasinski, JR Toothacker, WS Whitmore, JJ Iga, Y D'Agostini, G Marini, G Nigro, A Raso, M Hart, JC McCubbin, NA Shah, TP Epperson, D Heusch, C Rahn, JT Sadrozinski, HFW Seiden, A Wichmann, R Williams, DC Abramowicz, H Briskin, G Dagan, S Kananov, S Levy, A Abe, T Fusayasu, T Inuzuka, M Nagano, K Umemori, K Yamashita, T Hamatsu, R Hirose, T Homma, K Kitamura, S Matsushita, T Cirio, R Costa, M Ferrero, MI Maselli, S Monaco, V Peroni, C Petrucci, MC Ruspa, M Sacchi, R Solano, A Staiano, A Dardo, M Bailey, DC Fagerstroem, CP Galea, R Hartner, GF Joo, KK Levman, GM Martin, JF Orr, RS Polenz, S Sabetfakhri, A Simmons, D Teuscher, RJ Butterworth, JM Catterall, CD Jones, TW Lane, JB Saunders, RL Sutton, MR Wing, M Ciborowski, J Grzelak, G Kasprzak, M Muchorowski, K Nowak, RJ Pawlak, JM Pawlak, R Tymieniecka, T Wroblewski, AK Zakrzewski, JA Adamus, M Coldewey, C Eisenberg, Y Hochman, D Karshon, U Badgett, WF Chapin, D Cross, R Dasu, S Foudas, C Loveless, RJ Mattingly, S Reeder, DD Smith, WH Vaiciulis, A Wodarczyk, M Deshpande, A Dhawan, S Hughes, VW Bhadra, S Frisken, WR Khakzad, M Schmidke, WB CA ZEUS Collaboration TI Charged particles and neutral kaons in photoproduced jets at HERA SO EUROPEAN PHYSICAL JOURNAL C LA English DT Article ID DEEP-INELASTIC-SCATTERING; CENTRAL TRACKING DETECTOR; GAMMA-P INTERACTIONS; TO-LEADING ORDER; E+E ANNIHILATION; PARTON DISTRIBUTIONS; CROSS-SECTIONS; MONTE-CARLO; MESON PRODUCTION; HARD SCATTERING AB Charged particles (h(+/-)) and K-0 mesons have been studied in photoproduced events containing at least one jet of E-T > 8 GeV in a pseudorapidity interval (-0.5, 0.5) in the ZEUS laboratory frame. Distributions are presented in terms of transverse momentum, pseudorapidity and distance of the particle from the axis of a jet. The properties of h(+/-) within the jet are described well using the standard settings of PYTHIA, but the use of the multiparton interaction option improves the description outside the jets. C1 Argonne Natl Lab, Argonne, IL 60439 USA. Andrews Univ, Berrien Springs, MI 49104 USA. Ist Nazl Fis Nucl, I-40126 Bologna, Italy. Univ Bologna, I-40126 Bologna, Italy. Univ Bonn, Inst Phys, D-5300 Bonn, Germany. Univ Bristol, HH Wills Phys Lab, Bristol BS8 1TL, Avon, England. Univ Calabria, Dept Phys, I-87036 Cosenza, Italy. Ist Nazl Fis Nucl, Cosenza, Italy. Columbia Univ, Nevis Labs, Irvington, NY USA. Inst Nucl Phys, Krakow, Poland. Acad Min & Met, Fac Phys & Nucl Techniques, Krakow, Poland. Jagiellonian Univ, Dept Phys, Krakow, Poland. DESY, D-2000 Hamburg, Germany. DESY, IFH Zeuthen, Zeuthen, Germany. Univ Florence, I-50121 Florence, Italy. Ist Nazl Fis Nucl, I-50125 Florence, Italy. Ist Nazl Fis Nucl, Lab Nazl Frascati, I-00044 Frascati, Italy. Univ Freiburg, Fak Phys, D-7800 Freiburg, Germany. Univ Glasgow, Dept Phys & Astron, Glasgow G12 8QQ, Lanark, Scotland. Univ Hamburg, Inst Expt Phys 2, D-2000 Hamburg, Germany. Univ Hamburg, Inst Expt Phys 1, D-2000 Hamburg, Germany. Imperial Coll London, High Energy Nucl Phys Grp, London, England. Univ Iowa, Dept Phys & Astron, Iowa City, IA 52242 USA. Forschungszentrum Julich, Inst Kernphys, D-5170 Julich, Germany. Natl Lab High Energy Phys, KEK, Inst Particle & Nucl Studies, Tsukuba, Ibaraki 305, Japan. Korea Univ, Seoul 136701, South Korea. Univ Autonoma Madrid, Dept Fis Teor, Madrid, Spain. McGill Univ, Dept Phys, Quebec City, PQ, Canada. Meiji Gakuin Univ, Fac Gen Educ, Yokohama, Kanagawa, Japan. Moscow Engn Phys Inst, Moscow 115409, Russia. Moscow MV Lomonosov State Univ, Inst Nucl Phys, Moscow, Russia. Univ Amsterdam, NL-1012 WX Amsterdam, Netherlands. NIKHEF H, NL-1009 DB Amsterdam, Netherlands. Ohio State Univ, Dept Phys, Columbus, OH 43210 USA. Univ Oxford, Dept Phys, Oxford, England. Univ Padua, Dipartimento Fis, I-35100 Padua, Italy. Ist Nazl Fis Nucl, Padua, Italy. Penn State Univ, Dept Phys, University Pk, PA 16802 USA. Polytech Univ, Sagamihara, Kanagawa, Japan. Univ Roma La Sapienza, Dipartimento Fis, I-00185 Rome, Italy. Ist Nazl Fis Nucl, Rome, Italy. Rutherford Appleton Lab, Didcot OX11 0QX, Oxon, England. Univ Calif Santa Cruz, Santa Cruz, CA 95064 USA. Tel Aviv Univ, Raymond & Beverly Sackler Fac Exact Sci, Sch Phys, IL-69978 Tel Aviv, Israel. Univ Tokyo, Dept Phys, Tokyo 113, Japan. Tokyo Metropolitan Univ, Dept Phys, Tokyo, Japan. Ist Nazl Fis Nucl, I-10125 Turin, Italy. Univ Turin, Dipartimento Fis Sperimentale, Turin, Italy. Ist Nazl Fis Nucl, Alessandria, Italy. Univ Turin, Fac Sci 2, I-10124 Turin, Italy. Univ Toronto, Dept Phys, Toronto, ON, Canada. UCL, Dept Phys & Astron, London, England. Warsaw Univ, Inst Phys Expt, Warsaw, Poland. Inst Nucl Studies, PL-00681 Warsaw, Poland. Weizmann Inst Sci, Dept Particle Phys, IL-76100 Rehovot, Israel. Univ Wisconsin, Dept Phys, Madison, WI 53706 USA. Yale Univ, Dept Phys, New Haven, CT 06520 USA. York Univ, Dept Phys, N York, ON M3J 1P3, Canada. CNR, IROE, I-50127 Florence, Italy. RP Argonne Natl Lab, 9700 S Cass Ave, Argonne, IL 60439 USA. RI De Pasquale, Salvatore/B-9165-2008; Gladilin, Leonid/B-5226-2011; Wing, Matthew/C-2169-2008; Bashkirov, Vladimir/A-4818-2008; Doyle, Anthony/C-5889-2009; Golubkov, Yury/E-1643-2012; Proskuryakov, Alexander/J-6166-2012; Bremner, James/B-1632-2013; Katz, Uli/E-1925-2013; Wiggers, Leo/B-5218-2015; Hernandez Calama, Jose Maria/H-9127-2015; Tassi, Enrico/K-3958-2015; Morandin, Mauro/A-3308-2016; Solomin, Anatoly/C-3072-2016; Graciani Diaz, Ricardo/I-5152-2016; Capua, Marcella/A-8549-2015 OI De Pasquale, Salvatore/0000-0001-9236-0748; Gladilin, Leonid/0000-0001-9422-8636; Doyle, Anthony/0000-0001-6322-6195; Katz, Uli/0000-0002-7063-4418; Wiggers, Leo/0000-0003-1060-0520; Hernandez Calama, Jose Maria/0000-0001-6436-7547; Morandin, Mauro/0000-0003-4708-4240; Graciani Diaz, Ricardo/0000-0001-7166-5198; Castellini, Guido/0000-0002-0177-0643; Capua, Marcella/0000-0002-2443-6525 NR 58 TC 19 Z9 19 U1 0 U2 1 PU SPRINGER PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 1434-6044 EI 1434-6052 J9 EUR PHYS J C JI Eur. Phys. J. C PD MAR PY 1998 VL 2 IS 1 BP 77 EP 93 PG 17 WC Physics, Particles & Fields SC Physics GA ZC527 UT WOS:000072589300005 ER PT J AU Schenkel, T Barnes, AV Hamza, AV Schneider, DH AF Schenkel, T Barnes, AV Hamza, AV Schneider, DH TI Cluster ion emission in the interaction of slow highly charged ions with surfaces SO EUROPEAN PHYSICAL JOURNAL D LA English DT Article ID METAL-CLUSTERS; FRAGMENTATION; MODEL AB Cluster ion emission from a variety of surfaces upon impact of highly charged ions is investigated by time-of-flight secondary ion mass spectrometry. The yield of cluster ions as a function of cluster size for SiO2 and C-84 surface follow a power law decline with exponent approaching the -2 limit of the "equilibrium': and "shock wave" cluster emission models. While the decline of the cluster ion emission with cluster size is an exponential decay for highly oriented pyrolytic graphite upon Th70+ impact, the decline is more gradual than for Cs1+ impact, such that at C-16 the relative cluster yield is 1000 times higher. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. RP Schenkel, T (reprint author), Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. NR 28 TC 30 Z9 30 U1 0 U2 6 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 USA SN 1434-6060 J9 EUR PHYS J D JI Eur. Phys. J. D PD MAR PY 1998 VL 1 IS 3 BP 297 EP 302 DI 10.1007/s100530050096 PG 6 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA ZM841 UT WOS:000073581700011 ER PT J AU Bendele, GM Stephens, PW Fischer, JE AF Bendele, GM Stephens, PW Fischer, JE TI Octahedral cations in Rb3C60: Reconciliation of conflicting evidence from different probes SO EUROPHYSICS LETTERS LA English DT Article ID ABSORPTION FINE-STRUCTURE; ALKALI-METAL FULLERIDES; OFF-CENTER SITES; POWDER DIFFRACTION; LOCAL-STRUCTURE; RB-87 NMR; K-39 NMR; K3C60; SUPERCONDUCTORS; TRANSITION AB There is an apparent contradiction between X-ray diffraction, NMR and extended X-ray-absorption fine-structure (EXAFS) measurements on the structure of Rb3C60. Specifically, a possible displacement of the octahedral alkali cations away from their site center and the origin of a third observed Rb NMR line have been widely discussed. We address this question with X-ray powder diffraction as a function of temperature and find that the octahedral cation does have its equilibrium position at the site center with a large Debye-Waller factor. We show how this result can be reconciled with results of NMR and EXAFS. C1 SUNY Stony Brook, Dept Phys, Stony Brook, NY 11794 USA. Brookhaven Natl Lab, Natl Synchrotron Light Source Dept, Upton, NY 11973 USA. Univ Penn, Dept Mat Sci, Philadelphia, PA 19104 USA. Univ Penn, Res Struct Matter Lab, Philadelphia, PA 19104 USA. RP Bendele, GM (reprint author), SUNY Stony Brook, Dept Phys, Stony Brook, NY 11794 USA. NR 34 TC 8 Z9 8 U1 0 U2 6 PU E D P SCIENCES PI LES ULIS CEDEXA PA 7, AVE DU HOGGAR, PARC D ACTIVITES COURTABOEUF, BP 112, F-91944 LES ULIS CEDEXA, FRANCE SN 0295-5075 J9 EUROPHYS LETT JI Europhys. Lett. PD MAR 1 PY 1998 VL 41 IS 5 BP 553 EP 558 DI 10.1209/epl/i1998-00190-3 PG 6 WC Physics, Multidisciplinary SC Physics GA ZA641 UT WOS:000072386100014 ER PT J AU Saha, A Goldstein, S Cabelli, D Czapski, G AF Saha, A Goldstein, S Cabelli, D Czapski, G TI Determination of optimal conditions for synthesis of peroxynitrite by mixing acidified hydrogen peroxide with nitrite SO FREE RADICAL BIOLOGY AND MEDICINE LA English DT Article DE peroxynitrite; synthesis; H2O2; nitrite; nitrosation; free radical ID PULSE-RADIOLYSIS; SUPEROXIDE; OXIDE; CHEMISTRY; OXYGEN AB The measured parameters for the formation of peroxynitrous acid via the reaction of acidified hydrogen peroxide with nitrous acid and its self-decomposition corroborate with an earlier suggested mechanism in which H2NO2+ nitrosates H2O2. The activation energies for the formation and decay of peroxynitrous acid have been determined to be 15 and 19 kcal/mol, respectively. We found that perchlorate, nitrate, sulfate and phosphate ions have no effect on the formation and decay rates, whereas chloride ions enhance the rate of the formation of peroxynitrous acid at low peroxide concentrations, and have no effect at high peroxide concentrations. This suggests that at relatively low concentration of H2O2, Cl- competes with H2O2 for H2NO2+ to yield NOCl, which may also nitrosate H2O2. Simulation of the experimentally observed parameters for the decay and formation rates suggests that it is not possible to obtain 100% yield of peroxynitrite under any condition. High yields of peroxynitrite were obtained at room temperature using an efficient double mixer where acidified peroxide was mixed with nitrite; after an appropriate delay, the reaction was quenched with strong alkali. An excess of more than 10% of H2O2 over nitrite, or vice versa, is sufficient to get ca. 85-90% of peroxynitrite, almost free from nitrite or H2O2, respectively. The results also suggest that conventional use of ice-cold solutions of the reactants and the alkali solutions is not required if an efficient mixer and appropriate quenching times are available. (C) 1998 Elsevier Science Inc. C1 Hebrew Univ Jerusalem, Dept Phys Chem, IL-91904 Jerusalem, Israel. Brookhaven Natl Lab, Dept Chem, New York, NY USA. RP Czapski, G (reprint author), Hebrew Univ Jerusalem, Dept Phys Chem, IL-91904 Jerusalem, Israel. EM Czapski@HUJI.VMS.AC.IL NR 32 TC 107 Z9 110 U1 0 U2 10 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0891-5849 J9 FREE RADICAL BIO MED JI Free Radic. Biol. Med. PD MAR 1 PY 1998 VL 24 IS 4 BP 653 EP 659 DI 10.1016/S0891-5849(97)00365-1 PG 7 WC Biochemistry & Molecular Biology; Endocrinology & Metabolism SC Biochemistry & Molecular Biology; Endocrinology & Metabolism GA ZE226 UT WOS:000072770800017 PM 9559878 ER PT J AU Bain, RL Overend, RP Craig, KR AF Bain, RL Overend, RP Craig, KR TI Biomass-fired power generation SO FUEL PROCESSING TECHNOLOGY LA English DT Article; Proceedings Paper CT Engineering-Foundation Conference Biomass Usage for Utility and Industrial Power CY APR 28-MAY 02, 1996 CL SNOWBIRD, UTAH SP Engn Fdn DE power generation; biomass; bioenergy C1 Natl Renewable Energy Lab, Golden, CO 80401 USA. RP Craig, KR (reprint author), Natl Renewable Energy Lab, 1617 Cole Blvd, Golden, CO 80401 USA. OI Overend, Ralph/0000-0002-5442-0890 NR 29 TC 71 Z9 73 U1 2 U2 10 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0378-3820 J9 FUEL PROCESS TECHNOL JI Fuel Process. Technol. PD MAR PY 1998 VL 54 IS 1-3 BP 1 EP 16 DI 10.1016/S0378-3820(97)00058-1 PG 16 WC Chemistry, Applied; Energy & Fuels; Engineering, Chemical SC Chemistry; Energy & Fuels; Engineering GA ZU549 UT WOS:000074209200002 ER PT J AU Jenkins, BM Baxter, LL Miles, TR Miles, TR AF Jenkins, BM Baxter, LL Miles, TR Miles, TR TI Combustion properties of biomass SO FUEL PROCESSING TECHNOLOGY LA English DT Article; Proceedings Paper CT Engineering-Foundation Conference Biomass Usage for Utility and Industrial Power CY APR 28-MAY 02, 1996 CL SNOWBIRD, UTAH SP Engn Fdn DE biomass; alkali; silica; slagging; fouling; energy ID FLUIDIZED-BED COMBUSTION; FUEL; WOOD; EMISSIONS; ETHANOL; STRAW AB Properties of biomass relevant to combustion are briefly reviewed. The compositions of biomass among fuel types are variable, especially with respect to inorganic constituents important to the critical problems of fouling and slagging, Alkali and alkaline earth metals, in combination with other fuel elements such as silica and sulfur, and facilitated by the presence of chlorine, are responsible for many undesirable reactions in combustion furnaces and power boilers. Reductions in the concentrations of alkali metals and chlorine, created by leaching the elements from the fuel with water, yield remarkable improvements in ash fusion temperatures and confirm much of what is suggested regarding the nature of fouling by biomass fuels. Other influences of biomass composition are observed for the rates of combustion and pollutant emissions, Standardized engineering practices setting out protocols of analysis and interpretation may prove useful in reducing unfavorable impacts and industry costs, and further development is encouraged. (C) 1998 Elsevier Science B.V. C1 Univ Calif Davis, Dept Biol & Agr Engn, Davis, CA 95616 USA. Sandia Natl Labs, Livermore, CA USA. Thomas R Miles Consulting Engineers, Portland, OR USA. RP Jenkins, BM (reprint author), Univ Calif Davis, Dept Biol & Agr Engn, Davis, CA 95616 USA. RI Baxter, Larry/C-8567-2009 OI Baxter, Larry/0000-0002-0453-2659 NR 40 TC 732 Z9 753 U1 20 U2 202 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0378-3820 J9 FUEL PROCESS TECHNOL JI Fuel Process. Technol. PD MAR PY 1998 VL 54 IS 1-3 BP 17 EP 46 DI 10.1016/S0378-3820(97)00059-3 PG 30 WC Chemistry, Applied; Energy & Fuels; Engineering, Chemical SC Chemistry; Energy & Fuels; Engineering GA ZU549 UT WOS:000074209200003 ER PT J AU Baxter, LL Miles, TR Miles, TR Jenkins, BM Milne, T Dayton, D Bryers, RW Oden, LL AF Baxter, LL Miles, TR Miles, TR Jenkins, BM Milne, T Dayton, D Bryers, RW Oden, LL TI The behavior of inorganic material in biomass-fired power boilers: field and laboratory experiences SO FUEL PROCESSING TECHNOLOGY LA English DT Article DE inorganic material; biomass-fired power boilers; ash deposits ID COMBUSTION AB This paper highlights some of the major findings of the Alkali Deposits Investigation, a collaborative effort to understand the causes of unmanageable ash deposits in biomass-fired electric power boilers. A group of interested industrial institutions and the US DOE Energy Efficiency and Renewable Energy Office's Biomass Power Program through the National Renewable Energy Laboratory jointly sponsored the project. The industries contributed both funding and, in most cases, use of facilities to the project and included Mendota Biomass Power and Woodland Biomass Power (both associated with Thermo Electron Energy Systems), CMS Generation Operating (formerly Hydra-Co Operations), Wheelabrator, Shasta and Hudson Energy, Sithe Energy, Delano Energy, the Electric Power Research Institute, Foster Wheeler Development, and Elkraft Power of Denmark. Research contracts with Thomas R. Miles Consulting Design Engineers, Sandia National Laboratories, and The National Renewable Energy Laboratories provided the government portion of the funding. In addition, the University of California at Davis and the Bureau of Mines performed significant work in close collaboration with the other researchers. This summary highlights the major findings of the project more thoroughly discussed in a recent report [2]. We highlight fuel properties, bench-scale combustion tests, a framework for considering ash deposition processes, pilot-scale tests of biomass fuels, and field tests in commercially operating biomass power generation stations. Detailed chemical analyses of 11 biomass fuels representing a broad cross-section of commercially available fuels reveal their properties that relate to ash deposition tendencies. The fuels fall into three broad categories: (1) straws and grasses (herbaceous materials); (2) pits, shells, hulls and other agricultural by-products of a generally ligneous nature; and (3) woods and recycle fuels of commercial interest. Woods and wood-derived products represent the most commonly used biomass fuels. Herbaceous fuels contain silicon and potassium as their principal ash-forming constituents. They are also commonly high in chlorine relative to other biomass fuels. These properties portend potentially severe ash deposition problems at high or moderate combustion temperatures. The primary sources of these problems are shown to be: (1) the reaction of alkali with silica to form alkali silicates that melt or soften at low temperatures (can be lower than 700 degrees C, depending on composition), and (2) the reaction of alkali with sulfur to form alkali sulfates on combustor heat transfer surfaces. Alkali material plays a central role in both processes. The mobility of alkali material, defined as its ability to come in physical contact with other materials, is measured using chemical extractive techniques. Potassium is the dominant source of alkali in most biomass fuels. The analyses below indicate that essentially, all of the biologically occurring alkali, in particular potassium, has high mobility. The non-biologically occurring alkali is present as soil contaminants and additives to the fuels, such as clay fillers used in paper production. This non-biologically occurring alkali exhibits far lower mobility than the biological fraction. The relative amounts of biologically vs, non-biologically occurring material depend on fuel type and fuel handling. In the fuels investigated here, the dominant form of alkali was biologically occurring potassium. Some traditional indicators of deposit behavior, most notably ash fusion temperatures, poorly predict ash behavior compared with a more mechanistic interpretation of the data. Many of the agricultural by-products also contain high potassium concentrations with equally high potassium mobility. Some woods, on the other hand, contain far less ash overall, differing by as much as a factor of 40 from high-ash straws, for example. In addition, the ash-forming constituents contain greater amounts of calcium with less silicon. The total amount of potassium in wood is much lower than in straws, although this is not necessarily the case when expressed as a fraction of total ash. Calcium reacts with sulfur to form sulfates in ways analogous to potassium, but the lower mobility and vapor pressure of calcium and the structural properties of the deposits it forms are both more favorable to sustained furnace operation than the ashes formed from straws and grasses. Chlorine is shown to be a major factor in deposit formation. Chlorine facilitates the mobility of many inorganic compounds, in particular potassium. Potassium chloride is among the most stable high-temperature, gas-phase, alkali-containing species. Chlorine concentration often dictates the amount of alkali vaporized during combustion more strongly than the alkali concentration in the fuel. In most cases, the chlorine appears to play a shuttle role, facilitating the transport of alkali from the fuel to surfaces, where the alkali often forms sulfates. In the absence of sulfur, chlorides often reside on the surface. In the absence of chlorine, alkali hydroxides are the major stable gas-phase species in moist, oxidizing environments (combustion gases). Bench-scale combustion tests coupled with mass spectrometry techniques reveal the major species evolving from biomass samples during combustion. The fuels subjected to these combustion tests were also examined by chemical analyses. The tests indicate that the major release of alkali material occurs during the char combustion phase and that the primary form of stable alkali-bearing off-gases corresponds with thermodynamic estimates of product stability and vapor pressure. Investigations were performed varying temperature, oxygen concentration, and moisture levels and revealed thermodynamically consistent results; the amount of alkali vaporized increases with temperature and the amount of hydroxide formed increases with increasing moisture content. Details of other species released are also presented. Thermogravimetric and differential thermogravimetric analyses of the samples were also performed, the results of which prove to be marginally useful to predicting ash deposition. A conceptual framework expresses ash deposition as a combination of four mechanisms: inertial impaction, thermophoretic deposition, condensation, and chemical reaction is presented. This conceptual framework serves to organize the remaining discussion and observations of ash deposition at both pilot and commercial scale. The influences of boiler design, boiler operating conditions, and fuel properties on ash deposit behavior reveal themselves by emphasizing or reducing the role of one or more of these mechanisms and thereby changing deposit composition, phase, and properties. Pilot-scale investigations on the standard suite of fuels were carried out in an entrained-flow furnace. Isokinetically sampled fly ash samples and deposits collected on instrumented, temperature-regulated probes simulating both water-walls and convection pass provide the basis for in situ and subsequent ex situ examination of deposits. Deposit properties reveal spatial dependencies on probe surfaces that are consistent with both the commercial-scale tests and the conceptual framework for deposit growth and property development. In addition, changes in deposit composition with time, temperature, and other operation-relevant variables exhibit the same consistencies with commercial operation and the conceptual framework. Fuels containing high alkali and silica concentrations form alkali silicates that melt or sinter at low temperatures. The rates of deposit growth and sintering/melting increase with increasing temperature and chlorine concentration but are high at all boiler-relevant temperatures and chlorine concentrations for the straws and grasses. Surfaces exposed to impacting particles can accumulate silica and alkali silicates at very rapid rates. Surfaces exposed to combustion gases but less exposed to particle impaction show evidence of thermophoretic accumulation of deposits, vapor condensation, and sulfation of condensed alkali-laden vapors. These processes lead to deposits with markedly different properties (high reflectivity, modest thickness and growth rate) compared to the impacted regions. Fuels containing little alkali or silica indicate far less deposit growth and development of more manageable deposits, by which we mean soot blowers and boiler maintenance techniques are able to sustain operation of a facility for periods of many months without unscheduled shutdowns. Commercial-scale investigations using nearly every type of commercially significant biomass boiler design provide full scale data for analysis and comparison with pilot-scale results. Bubbling fluid beds, circulating fluid beds, and various grate-based combustors fed by stokers, augers, and a cigar burner provided the data for comparison. Fuel types ranged from wood-derived material with blended agricultural by-products to straws, sometimes blended with urban wood fuel. Many of the commercial-scale experiments were conducted in the context of commercial operation and employed varying compositions in the fuel. In all cases, comparisons of deposit composition with position in the boiler, type of deposit surface, position on the surface, and fuel properties reveal complete consistency with the fuel analyses, bench-scale combustion results, pilot-scale results, and the conceptual framework. Fuels containing high alkali and silica fractions exhibited the same rapid accumulation of ash deposits with the same sintered/molten character as was observed in the pilot-scale tests. Advanced mineralogical examinations of selected deposits indicate chemical compositions consistent with the conceptual framework and are presented as appendix material. The deposit properties are consistent with the conceptual framework for their formation and the observed bench-scale combustion results. Fuels with less alkali, chlorine, and silica, with less total ash-forming material, and with higher calcium contents exhibit more manageable ash deposits. Wood and non-recyclable paper generated the most manageable deposits. This report provides highlights of a more detailed analysis of fuel property, operating condition, and boiler design issues that dictate as deposit formation and property development [1,2]. The span of investigations from bench-top experiments to commercial operation and observations, including both practical illustrations and theoretical background, provides a self-consistent and reasonably robust basis to understand the qualitative nature of ash deposit formation in biomass boilers. While there remain many quantitative details to be pursued to complete our understanding, this project encapsulates essentially all of the conceptual aspects of the issue. It provides a basis for understanding and potentially resolving the technical and environmental issues associated with ash deposition during biomass combustion. Publised by Elsevier Science B.V. C1 Sandia Natl Labs, Combust Res Facil, Livermore, CA 94550 USA. Univ Calif Davis, Dept Biol & Agr Engn, Davis, CA USA. Natl Renewable Energy Lab, Golden, CO USA. Foster Wheeler Dev, Clinton, NJ USA. US Bur Mines, Albany Res Ctr, Albany, NY USA. RP Baxter, LL (reprint author), Sandia Natl Labs, Combust Res Facil, Livermore, CA 94550 USA. RI zhang, shihong/G-8433-2012; Baxter, Larry/C-8567-2009 OI Baxter, Larry/0000-0002-0453-2659 NR 18 TC 307 Z9 318 U1 12 U2 131 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0378-3820 J9 FUEL PROCESS TECHNOL JI Fuel Process. Technol. PD MAR PY 1998 VL 54 IS 1-3 BP 47 EP 78 DI 10.1016/S0378-3820(97)00060-X PG 32 WC Chemistry, Applied; Energy & Fuels; Engineering, Chemical SC Chemistry; Energy & Fuels; Engineering GA ZU549 UT WOS:000074209200004 ER PT J AU Ekmann, JM Winslow, JC Smouse, SM Ramezan, M AF Ekmann, JM Winslow, JC Smouse, SM Ramezan, M TI International survey of cofiring coal with biomass and other wastes SO FUEL PROCESSING TECHNOLOGY LA English DT Article; Proceedings Paper CT Engineering-Foundation Conference Biomass Usage for Utility and Industrial Power CY APR 28-MAY 02, 1996 CL SNOWBIRD, UTAH SP Engn Fdn DE biomass; cofire; coal C1 Fed Energy Technol Ctr, Pittsburgh, PA 15213 USA. Burns & Roe Serv, Oradell, NJ USA. RP Ekmann, JM (reprint author), Fed Energy Technol Ctr, Pittsburgh, PA 15213 USA. NR 33 TC 33 Z9 34 U1 0 U2 5 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0378-3820 J9 FUEL PROCESS TECHNOL JI Fuel Process. Technol. PD MAR PY 1998 VL 54 IS 1-3 BP 171 EP 188 DI 10.1016/S0378-3820(97)00068-4 PG 18 WC Chemistry, Applied; Energy & Fuels; Engineering, Chemical SC Chemistry; Energy & Fuels; Engineering GA ZU549 UT WOS:000074209200011 ER PT J AU Smouse, SM Staats, GE Rao, SN Goldman, R Hess, D AF Smouse, SM Staats, GE Rao, SN Goldman, R Hess, D TI Promotion of biomass cogeneration with power export in the Indian sugar industry SO FUEL PROCESSING TECHNOLOGY LA English DT Article; Proceedings Paper CT Engineering-Foundation Conference Biomass Usage for Utility and Industrial Power CY APR 28-MAY 02, 1996 CL SNOWBIRD, UTAH SP Engn Fdn DE biomass cogeneration; sugar industry; India AB To meet India's projected power demand over the next 25 years, over 300,000 MVe of new generating capacity will need to be installed. Cogeneration, the combined generation of steam and electricity, is an efficient and cost-effective means to save energy and reduce pollution. Many studies around the world have identified sugar mill cogeneration as an attractive low-cost power option. Most studies estimate the cogeneration potential of India's sugar mills at around 3500 MWe. The United States Agency for International Development (USAID) has implemented a Greenhouse Gas Pollution Prevention (GEP) Project to assist in the direction and pace of India's power sector development. This seven-year, US$19 million effort is funded through the United States' contribution to the pilot phase of the Global Environmental Facility (GEF). The GEF's mission is to assist developing countries in investing in environmental protection initiatives that yield global benefits in terms of reduced or avoided greenhouse gas emissions. Technical aspects of the GEP Project are being managed by the United States Department of Energy's Pittsburgh Energy Technology Center. The objective of the Advanced Bagasse Cogeneration (ABC) Component of the GEP Project is to promote year-round cogeneration in Indian sugar mills with power export using only biomass as a fuel. The structure of the ABC Component, which is implemented through technical assistance and investment subcomponents, and the status of various activities are reviewed. Also, sugar production and economics are reviewed from both a global and local perspective to reveal how they impact the potential for cogeneration projects in Indian sugar mills. Progress in the Indian sugar industry should pave the way for cogeneration projects in other industrial sectors, such as paper, chemicals, and textiles. Contributions from these sectors are important if India is to meet its huge power generation needs. (C) 1998 Published by Elsevier Science B.V. C1 US DOE, Pittsburgh Energy Technol Ctr, Pittsburgh, PA 15236 USA. Burns & Roe Serv, Pittsburgh, PA USA. US Agcy Int Dev, Off Energy Environm & Enterprise, New Delhi, India. RP Smouse, SM (reprint author), US DOE, Pittsburgh Energy Technol Ctr, Pittsburgh, PA 15236 USA. NR 20 TC 21 Z9 21 U1 0 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0378-3820 J9 FUEL PROCESS TECHNOL JI Fuel Process. Technol. PD MAR PY 1998 VL 54 IS 1-3 BP 227 EP 247 DI 10.1016/S0378-3820(97)00071-4 PG 21 WC Chemistry, Applied; Energy & Fuels; Engineering, Chemical SC Chemistry; Energy & Fuels; Engineering GA ZU549 UT WOS:000074209200014 ER PT J AU Asaki, TJ Hoffer, JK Sheliak, JD AF Asaki, TJ Hoffer, JK Sheliak, JD TI Ultrasonic characterization of inertial confinement fusion targets SO FUSION TECHNOLOGY LA English DT Article DE ICF target characterization; ultrasound ID ACOUSTIC-RESONANCE FREQUENCIES; DEFORMED SPHERICAL RESONATORS; TRITIUM AB Inertial confinement fusion (ICF) targets designed to achieve ignition must meet strict surface smoothness and sphericity requirements. One potentially valuable method for evaluating the quality of these targets is resonant ultrasound spectroscopy (RUS). When applied to simple geometries, such as layered spheres ol rectangular parallelepipeds, RUS may yield significant information about alloy homogeneity, elastic constants, cavity geometry, the presence of gross defects such as cracking or hemishell bonding problems, and properties of interior fluids. The strengths of RUS techniques for ICF target characterization include applicability at all temperatures of interest with a single apparatus, high sensitivity in frequency spectral measurements, and the inherent acoustic indifference to optically opaque samples. Possible applications and the limitations of RUS methods for examining layer geometry and material properties are addressed. Preliminary room temperature experiments with a deuterium-filled aluminum shell ape used to evaluate the utility of many of the described applications. The frequency spectrum compares favorably with theory and displays measurable mode splitting, acoustic-mode resonance widths indicative of cavity boundary dissipative mechanisms, and Low-e elastic modes. The acoustic cavity resonance structure confirms the internal gas density and is used to calculate the two lowest even-order cavity boundary perturbation amplitudes. C1 Univ Calif Los Alamos Natl Lab, Div Mat Sci & Technol, Los Alamos, NM 87545 USA. Gen Atom Inc, San Diego, CA 92186 USA. RP Asaki, TJ (reprint author), Univ Calif Los Alamos Natl Lab, Div Mat Sci & Technol, MS K764, Los Alamos, NM 87545 USA. NR 13 TC 8 Z9 8 U1 0 U2 2 PU AMER NUCLEAR SOCIETY PI LA GRANGE PK PA 555 N KENSINGTON AVENUE, LA GRANGE PK, IL 60525 USA SN 0748-1896 J9 FUSION TECHNOL JI Fusion Technol. PD MAR PY 1998 VL 33 IS 2 BP 171 EP 181 PG 11 WC Nuclear Science & Technology SC Nuclear Science & Technology GA ZB468 UT WOS:000072475000008 ER PT J AU Ongena, JPHE Evrard, M McCune, D AF Ongena, JPHE Evrard, M McCune, D TI Numerical transport codes SO FUSION TECHNOLOGY LA English DT Article; Proceedings Paper CT 3rd Carolus Magnus Summer School on Plasma Physics CY SEP 08-19, 1997 CL SPA, BELGIUM SP Trilateral Euregio Cluster, Belgium State, Ecole Royale Mil, Lab Plasma Phys, Belgium, Koninklijke Mil Sch, Belgium, FOM Inst Plasmafys, Netherlands, Assoc Euratom, Inst Plasmaphys, Germany, Forschungzen Julich, Germany, European Commiss, ELECTRABEL, Belgium, BELGATOM, Belgium, Adv Mech & Optical Syst, Belgium ID ION THERMAL-CONDUCTIVITY; TOKAMAK PLASMA; RECONSTRUCTION; PROFILE AB This paper gives a brief introduction on numerical transport codes. The relevant equations which are used in these codes are established, and on the basis of these equations, the necessary calculations needed to resolve them are pointed out. Finally, some examples are given, illustrating their application. C1 Assoc EURATOM Etat Belge, Ecole Royale Mil, Lab Phys Plasmas, B-1000 Brussels, Belgium. Princeton Univ, Princeton Plasma Phys Lab, Princeton, NJ 08543 USA. RP Ongena, JPHE (reprint author), Assoc EURATOM Etat Belge, Ecole Royale Mil, Lab Phys Plasmas, B-1000 Brussels, Belgium. NR 21 TC 19 Z9 19 U1 0 U2 1 PU AMER NUCLEAR SOCIETY PI LA GRANGE PK PA 555 N KENSINGTON AVENUE, LA GRANGE PK, IL 60525 USA SN 0748-1896 J9 FUSION TECHNOL JI Fusion Technol. PD MAR PY 1998 VL 33 IS 2T BP 181 EP 191 PG 11 WC Nuclear Science & Technology SC Nuclear Science & Technology GA ZH018 UT WOS:000073063900023 ER PT J AU Anovitz, LM Blencoe, JG Joyce, DB Horita, J AF Anovitz, LM Blencoe, JG Joyce, DB Horita, J TI Precise measurement of the activity/composition relations of H2O-N-2 and H2O-CO2 fluids at 500 degrees C, 500 bars SO GEOCHIMICA ET COSMOCHIMICA ACTA LA English DT Article ID HIGH-PRESSURE EXPERIMENTS; EXCESS MOLAR ENTHALPIES; REDLICH-KWONG EQUATION; THERMODYNAMIC PROPERTIES; CH4-CO2-H2O SYSTEM; ELEVATED PRESSURES; HIGH-TEMPERATURES; MIXTURES; WATER; NITROGEN AB The activity/composition relations of H2O-N-2 and H2O-CO2 fluids have been measured at 500 degrees C, 500 bars. The results are more accurate, and much more precise, than any currently available, especially for H2O-poor compositions. Samples were reacted at fixed water activities (0.062 less than or equal to a(H2O) less than or equal to 0.777), using Cu3N as the source of N-2, and Ag-oxalate as the source of CO2. After each experiment the masses of water and gas in the samples were analyzed manometrically. Results depend on the value used for the hydrogen fugacity for pure H2O in equilibrium with the oxide buffer, but using a newly measured value for Ni-NiO and fitting the data to a two-parameter Margules equation yields: or H2O-N-2 fluids: W-G,W-H2O = 3455.0 J/mol, W-G,W-N2 = 1990.1 J/mol; and for H2O-CO2 fluids: W-G,W-H2O = 3882.5 J/mol, W-G,W-CO2 = 4902.6 J/mol. As uncertainties are not orthogonal, standard errors cannot be given. The data suggest that H2O-CO2 fluids exhibit large positive deviations from ideality at 500 degrees C, 500 bars, in marked contrast to values predicted by available equations of state. These results indicate that more accurate models for both H2O-N-2 and H2O-CO2 fluids are needed. Copyright (C) 1998 Elsevier Science Ltd. C1 Oak Ridge Natl Lab, Div Chem & Analyt Sci, Geochem Grp, Oak Ridge, TN 37831 USA. RP Anovitz, LM (reprint author), Oak Ridge Natl Lab, Div Chem & Analyt Sci, Geochem Grp, Oak Ridge, TN 37831 USA. EM anovitzlm@ornl.gov RI Anovitz, Lawrence/P-3144-2016 OI Anovitz, Lawrence/0000-0002-2609-8750 NR 73 TC 10 Z9 10 U1 1 U2 8 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0016-7037 J9 GEOCHIM COSMOCHIM AC JI Geochim. Cosmochim. Acta PD MAR PY 1998 VL 62 IS 5 BP 815 EP 829 DI 10.1016/S0016-7037(98)00027-1 PG 15 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA ZJ764 UT WOS:000073250600007 ER PT J AU Pitzer, KS Das, B AF Pitzer, KS Das, B TI Thermodynamic properties of Na2SO4(aq) above 200 degrees C SO GEOCHIMICA ET COSMOCHIMICA ACTA LA English DT Article ID ALKALI-METAL SULFATES; VOLUMETRIC PROPERTIES; AQUEOUS-SOLUTIONS AB In 1988 Pabalan and Fitter published in this journal two equations valid for various thermodynamic functions for Na2SO4(aq) at temperatures to 300 degrees C. One was based on their measurements at 200 bars pressure, with other data at low temperatures converted to that pressure. The second equation was for 1 bar to 100 degrees C and P-sat at higher temperatures. At temperatures below 200 degrees C, the effect of pressure was reasonably well known from volumetric measurements and other data, but above 200 degrees C there were no volumetric data available. Thus, the activity and osmotic coefficients reported for P-sat above 200 degrees C were based on estimates of the effect of the (200 bar-P-sat) pressure difference. Recent volumetric measurements to 300 degrees C of Obsil et al. (1996, 1997) yield accurate values for this pressure effect, which are presented here. Comparisons show that the estimates of 1988 were good and that the activity coefficients of 1988 are accurate within the uncertainties of various other input data. Copyright (C) 1998 Elsevier Science Ltd. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. RP Pitzer, KS (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. NR 7 TC 4 Z9 4 U1 0 U2 3 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0016-7037 J9 GEOCHIM COSMOCHIM AC JI Geochim. Cosmochim. Acta PD MAR PY 1998 VL 62 IS 5 BP 915 EP 916 DI 10.1016/S0016-7037(97)00380-3 PG 2 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA ZJ764 UT WOS:000073250600014 ER PT J AU Wesolowski, DJ Benezeth, P Palmer, DA AF Wesolowski, DJ Benezeth, P Palmer, DA TI ZnO solubility and Zn2+ complexation by chloride and sulfate in acidic solutions to 290 degrees C with in-situ pH measurement SO GEOCHIMICA ET COSMOCHIMICA ACTA LA English DT Article ID AQUEOUS-SOLUTIONS; THERMODYNAMIC PROPERTIES; HIGH-TEMPERATURES; ELECTRICAL CONDUCTANCES; HYDROTHERMAL SOLUTIONS; ELEVATED-TEMPERATURES; OXIDE SOLUBILITY; HIGH-PRESSURES; WATER; ZINC AB The solubility of zincite in mildly to strongly acidic aqueous solutions, according to the reaction ZnO + 2H(+) double left right arrow Zn2+ + H2O, has been measured at ionic strengths of 0.03-1.0 (stoichiometric molal basis) from 50 to 290 degrees C at saturation vapor pressure in sodium triffuoromethanesulfonate solutions (NaTriflate, a noncomplexing 1:1 electrolyte). The hydrogen-electrode concentration cells employed in this study permit continuous and highly accurate pH measurement at elevated temperatures, and periodic sampling to determine the dissolved metal content of the experimental solution. The solubility of zincite is shown to be reversible at 200 degrees C by addition of acidic and basic titrants, at constant ionic strength. The equilibrium constant is precisely described (+/-0.05 log units) by the function log K = -4.0168 + 4527.66/T. One additional adjustable parameter, together with an extended Debye-Huckel function, is sufficient to model the ionic strength dependence of the reaction. The solubility product at infinite dilution obtained from this study is in quantitative agreement with the thermodynamic model of Ziemniak (1992). This experimental approach is demonstrated to be advantageous in studying the complexation of Zn2+ with Cl- and SO42-, by titrations involving the appropriate anion into NaTriflate solutions pre-equilibrated with zincite at constant temperature and ionic strength. Formation constants in 0.1 molal NaTriflate for the reaction Zn2+ + yL(z-) double left right arrow Zn(L)(y)(2-yz) are reported for ZnCl+, ZnCl2 degrees and ZnSO4 degrees at 200 degrees C (log Q = 1.7 +/- 0.1, 3.0 +/- 0.1, and 2.6 +/- 0.1, respectively). Estimates of the equilibrium constants for the chloride species at infinite dilution and 200 degrees C are log K = 2.5 +/- 0.1 (ZnCl+), and 4.2 +/- 0.1 (ZnCl2 degrees). This value for the dichlorozinc complex agrees quantitatively with values reported by Bourcier and Barnes (1987) and Ruaya and Seward (1986). However, the latter authors give a value for the monochlorozinc complex (log K = 4.01 +/- 0.02) that is markedly different from our result and that of Bourcier and Barnes (1987) (log K = 3.1 +/- 0.3). Copyrights (C) 1998 Elsevier Science Ltd. C1 Oak Ridge Natl Lab, Div Chem & Analyt Sci, Oak Ridge, TN 37831 USA. RP Wesolowski, DJ (reprint author), Oak Ridge Natl Lab, Div Chem & Analyt Sci, Oak Ridge, TN 37831 USA. EM dqw@ornl.gov RI BENEZETH, Pascale/H-7969-2014 OI BENEZETH, Pascale/0000-0002-1841-2383 NR 48 TC 32 Z9 32 U1 3 U2 17 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0016-7037 J9 GEOCHIM COSMOCHIM AC JI Geochim. Cosmochim. Acta PD MAR PY 1998 VL 62 IS 6 BP 971 EP 984 DI 10.1016/S0016-7037(98)00039-8 PG 14 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA ZP906 UT WOS:000073800500006 ER PT J AU Nicolussi, GK Pellin, MJ Lewis, RS Davis, AM Amari, S Clayton, RN AF Nicolussi, GK Pellin, MJ Lewis, RS Davis, AM Amari, S Clayton, RN TI Molybdenum isotopic composition of individual presolar silicon carbide grains from the Murchison meteorite SO GEOCHIMICA ET COSMOCHIMICA ACTA LA English DT Article ID ASYMPTOTIC GIANT BRANCH; S-PROCESS BA; SIC GRAINS; INTERSTELLAR GRAINS; MASS-SPECTROMETRY; NOBLE-GASES; GRAPHITE; CARBON; NUCLEOSYNTHESIS; SUPERNOVA AB We report the isotopic composition of molybdenum in twenty-three presolar SiC grains from the Murchison meteorite which have been measured by resonant ionization mass spectrometry (RIMS). Relative to terrestrial abundance land normalized to s-process-only (96)Mo), the majority of the analyzed grains show strong depletions in the p-process isotopes (92)Mo and (94)Mo and the r-process isotope (100)Mo. Sixteen of these grains have delta-values <-600% for these three isotopes. The observed isotopic patterns of Mo from mainstream SiC grains clearly reveal the signature of s-process nucleosynthesis. Three-isotope plots of all grain data (delta(i)Mo vs. delta(92)Mo) show strong linear correlations with characteristic slopes. This finding suggests mixing of solar-like material and pure s-process material in the parent stars. Comparison with evolutionary calculations of nucleosynthesis and mixing in red giants suggests that low-mass thermally-pulsed symptotic giant branch (TP-AGB) stars are the most likely site for the observed s-process nucleosynthesis. Copyright (C) 1998 Elsevier Science Ltd. C1 Univ Chicago, Enrico Fermi Inst, Chicago, IL 60637 USA. Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. Argonne Natl Lab, Div Chem, Argonne, IL 60439 USA. Univ Chicago, Dept Chem, Chicago, IL 60637 USA. Univ Chicago, Dept Geophys Sci, Chicago, IL 60637 USA. Washington Univ, McDonnell Ctr Space Sci, St Louis, MO 63130 USA. RP Nicolussi, GK (reprint author), Univ Chicago, Enrico Fermi Inst, 5640 S Ellis Ave, Chicago, IL 60637 USA. EM gunther_nicoluss@qmgate.anl.gov RI Pellin, Michael/B-5897-2008; OI Pellin, Michael/0000-0002-8149-9768; Davis, Andrew/0000-0001-7955-6236 NR 51 TC 82 Z9 84 U1 0 U2 4 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0016-7037 J9 GEOCHIM COSMOCHIM AC JI Geochim. Cosmochim. Acta PD MAR PY 1998 VL 62 IS 6 BP 1093 EP 1104 DI 10.1016/S0016-7037(98)00038-6 PG 12 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA ZP906 UT WOS:000073800500009 ER PT J AU Chang, H VanDyke, JP Solano, M McMechan, GA Epili, D AF Chang, H VanDyke, JP Solano, M McMechan, GA Epili, D TI 3-D prestack Kirchhoff depth migration: From prototype to production in a massively parallel processor environment SO GEOPHYSICS LA English DT Article ID REFLECTION TOMOGRAPHY; FOCUSING ANALYSIS; EIKONAL EQUATION; 3 DIMENSIONS; TRAVEL-TIME; VELOCITY AB Portable, production-scale 3-D prestack Kirchhoff depth migration software capable of full-volume imaging has been successfully implemented and applied to a six-million trace (46.9 Gbyte) marine data set from a salt/subsalt play in the Gulf of Mexico. Velocity model building and updates use an image-driven strategy and were performed in a Sun Spare environment. Images obtained by 3-D prestack migration after three velocity iterations are substantially better focused and reveal drilling targets that were not visible in images obtained from conventional 3-D poststack time migration. Amplitudes are well preserved, so anomalies associated with known reservoirs conform to the petrophysical predictions. Prototype development was on an 8-node Intel iPSC860 computer; the production version was run on an 1824-node Intel Paragon computer. The code has been successfully ported to GRAY (T3D) and Unix workstation (PVM) environments. C1 Oryx Energy Co, Dallas, TX 75221 USA. Sandia Natl Labs, Albuquerque, NM 87185 USA. Univ Texas, Ctr Lithospher Studies, Richardson, TX 75083 USA. RP Chang, H (reprint author), Oryx Energy Co, POB 2880, Dallas, TX 75221 USA. NR 43 TC 8 Z9 9 U1 0 U2 1 PU SOC EXPLORATION GEOPHYSICISTS PI TULSA PA 8801 S YALE ST, TULSA, OK 74137 USA SN 0016-8033 J9 GEOPHYSICS JI Geophysics PD MAR-APR PY 1998 VL 63 IS 2 BP 546 EP 556 DI 10.1190/1.1444355 PG 11 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA ZD883 UT WOS:000072734000024 ER PT J AU Williams, RS Lincoln, DE Norby, RJ AF Williams, RS Lincoln, DE Norby, RJ TI Leaf age effects of elevated CO(2)-grown white oak leaves on spring-feeding lepidopterans SO GLOBAL CHANGE BIOLOGY LA English DT Article DE elevated CO(2); leaf phytochemistry; Lymantria dispar; Malacosoma disstria; nitrogen utilization; Quercus alba ID INSECT HERBIVORE INTERACTIONS; CARBON-DIOXIDE ENRICHMENT; FOREST TENT CATERPILLAR; GYPSY-MOTH; NUTRITIONAL ECOLOGY; NUTRIENT BALANCE; CO2 ENVIRONMENTS; JUNONIA-COENIA; LOBLOLLY-PINE; GROWTH AB Folivorous insect responses to elevated CO(2)-grown tree species may be complicated by phytochemical changes as leaves age. For example, young expanding leaves in tree species may be less affected by enriched CO(2)-alterations in leaf phytochemistry than older mature leaves due to shorter exposure times to elevated CO(2) atmospheres. This, in turn, could result in different effects on early vs. late instar larvae of herbivorous insects. To address this, seedlings of white oak (Quercus alba L.), grown in open-top chambers under ambient and elevated CO(2), were fed to two important early spring feeding herbivores; gypsy moth (Lymantria dispar L.), and forest tent caterpillar (Malacosoma disstria Hubner). Young, expanding leaves were presented to early instar larvae, and older fully expanded or mature leaves to late instar larvae. Young leaves had significantly lower leaf nitrogen content and significantly higher total nonstructural carbohydrate:nitrogen ratio as plant CO(2) concentration rose, while nonstructural carbohydrates and total carbon-based phenolics were unaffected by plant CO(2) treatment. These phytochemical changes contributed to a significant reduction in the growth rate of early instar gypsy moth larvae, while growth rates of forest tent caterpillar were unaffected. The differences in insect responses were attributed to an increase in the nitrogen utilization efficiency (NUE) of early instar forest tent caterpillar larvae feeding on elevated CO(2)-grown leaves, while early instar gypsy moth larval NUE remained unchanged among the treatments. Later instar larvae of both insect species experienced larger reductions in foliage quality on elevated CO(2)-grown leaves than earlier instars, as the carbohydrate:nitrogen ratio of leaves substantially increased. Despite this, neither insect species exhibited changes in growth or consumption rates between CO(2) treatments in the later instar. An increase in NUE was apparently responsible for offsetting reduced foliar nitrogen for the late instar larvae of both species. C1 Univ S Carolina, Dept Biol Sci, Columbia, SC 29208 USA. Oak Ridge Natl Lab, Div Environm Sci, Oak Ridge, TN 37831 USA. RP Williams, RS (reprint author), Appalachian State Univ, Dept Biol, 572 Rivers St, Boone, NC 28608 USA. EM willmsrs@appstate.edu RI Norby, Richard/C-1773-2012 OI Norby, Richard/0000-0002-0238-9828 NR 53 TC 47 Z9 60 U1 0 U2 8 PU WILEY-BLACKWELL PI MALDEN PA COMMERCE PLACE, 350 MAIN ST, MALDEN 02148, MA USA SN 1354-1013 J9 GLOBAL CHANGE BIOL JI Glob. Change Biol. PD MAR PY 1998 VL 4 IS 3 BP 235 EP 246 DI 10.1046/j.1365-2486.1998.00127.x PG 12 WC Biodiversity Conservation; Ecology; Environmental Sciences SC Biodiversity & Conservation; Environmental Sciences & Ecology GA ZF050 UT WOS:000072857700001 ER PT J AU Thompson, M Rayner, S AF Thompson, M Rayner, S TI Risk and governance Part 1: The discourses of climate change SO GOVERNMENT AND OPPOSITION LA English DT Article ID MENTAL MODELS; PEOPLE KNOW; ENERGY USE AB JUST OVER A QUARTER OF A CENTURY AGO TWO SEMINAL PAPERS ON risk were published: Chauncey Starr's 'Social Benefit Versus Technological Risk'(1) and Mary Douglas's 'Environments At Risk'.(2) The former insisted on the fundamental distinction between objective risk and perceived risk; the latter argued that there is often no valid way of drawing that distinction. In the United States, the National Academy of Sciences has consistently held to the objective/perceived distinction (until the last year or so) and the same has been true of Britain's Royal Society (until last year). Over the intervening years, and regardless of how many mattresses (in the form of handbooks and reports from august committees and working groups) were piled on top of one another, Mary Douglas's pea still rubbed its way through. Hence the very recent switch on both sides of the Atlantic.(3) The last mattress-piling effort, in Britain, was in 1992,(4) when the Royal Society set out to re-work its handbook of ten years before.(5) Its launch was not a successful event. C1 Musgrave Inst, London, England. Univ Bergen, Dept Polit, N-5020 Bergen, Norway. Pacific NW Lab, Richland, WA USA. RP Thompson, M (reprint author), Musgrave Inst, London, England. NR 66 TC 42 Z9 42 U1 0 U2 3 PU GOVERNMENT OPPOSITION LTD PI LONDON PA LONDON SCH OF ECON AND POL SCI HOUGHTON ST, LONDON, ENGLAND WC2 2AE SN 0017-257X J9 GOV OPPOS JI Gov. Oppos. PD SPR PY 1998 VL 33 IS 2 BP 139 EP 166 DI 10.1111/j.1477-7053.1998.tb00787.x PG 28 WC Political Science SC Government & Law GA ZL431 UT WOS:000073432200001 ER PT J AU Steiner, A Kimmel, R Bruckstein, AM AF Steiner, A Kimmel, R Bruckstein, AM TI Planar shape enhancement and exaggeration SO GRAPHICAL MODELS AND IMAGE PROCESSING LA English DT Article ID CURVES; CURVATURE; FRONTS AB A local smoothing operator applied in the reverse direction is used to obtain planar shape enhancement and exaggeration. Inversion of a smoothing operator is an inherently unstable operation. Therefore, a stable numerical scheme simulating the inverse smoothing effect is introduced. Enhancement is obtained for short time spans of evolution. Carrying the evolution further yields shape exaggeration or caricaturization effect. Introducing attraction forces between the evolving shape and the initial one yields an enhancement process that converges to a steady state. These forces depend on the distance of the evolving curve from the original one and on local properties. Results of applying the unrestrained and restrained evolution on planar shapes, based on a stabilized inverse geometric heat equation, are presented showing enhancement and caricaturization effects. (C) 1998 Academic Press. C1 Technion Israel Inst Technol, Dept Elect Engn, IL-32000 Haifa, Israel. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Math, Berkeley, CA 94720 USA. Technion Israel Inst Technol, Dept Comp Sci, IL-32000 Haifa, Israel. RP Technion Israel Inst Technol, Dept Elect Engn, IL-32000 Haifa, Israel. EM steiner@tx.technion.ac.il; ron@math.lbl.gov; freddy@cs.technion.ac.il NR 27 TC 9 Z9 10 U1 0 U2 0 PU ACADEMIC PRESS INC ELSEVIER SCIENCE PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 1077-3169 J9 GRAPH MODEL IM PROC JI Graph. Models Image Process. PD MAR PY 1998 VL 60 IS 2 BP 112 EP 124 DI 10.1006/gmip.1998.0461 PG 13 WC Computer Science, Software Engineering SC Computer Science GA ZJ799 UT WOS:000073254400003 ER PT J AU Narasimhan, TN AF Narasimhan, TN TI Something to think about ... Darcy-Buckingham's law SO GROUND WATER LA English DT Editorial Material C1 Univ Calif Berkeley, Dept Mat Sci & Mineral Engn, Dept Environm Sci Policy & Management, Earth Sci Div,EO Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. RP Narasimhan, TN (reprint author), Univ Calif Berkeley, Dept Mat Sci & Mineral Engn, Dept Environm Sci Policy & Management, Earth Sci Div,EO Lawrence Berkeley Natl Lab, 467 Evans Hall, Berkeley, CA 94720 USA. NR 0 TC 1 Z9 1 U1 0 U2 0 PU GROUND WATER PUBLISHING CO PI WESTERVILLE PA 601 DEMPSEY RD, WESTERVILLE, OH 43081 USA SN 0017-467X J9 GROUND WATER JI Ground Water PD MAR-APR PY 1998 VL 36 IS 2 BP 194 EP 195 DI 10.1111/j.1745-6584.1998.tb01080.x PG 2 WC Geosciences, Multidisciplinary; Water Resources SC Geology; Water Resources GA YZ695 UT WOS:000072281600002 ER PT J AU McCarthy, J Shevenell, L AF McCarthy, J Shevenell, L TI Obtaining representative ground water samples in a fractured and karstic formation SO GROUND WATER LA English DT Article ID MONITORING WELLS; TRANSPORT; METALS AB Ground water was sampled from a number of wells along recharge pathways between fractured shale and karstic carbonate formations to determine the effect of sampling methods on the colloid abundance and the chemical and hydrologic mechanisms controlling the abundance of ground water colloids. Low-flow minimal drawdown purging and sampling produced samples with much lower and more consistent turbidity than had been obtained during compliance monitoring of the same wells using much higher now rates and purging of three well volumes. Although some low-yielding wells required very low pumping rates (10 ml/min) to prevent drawdown, water quality parameters (temperature, pH, electrode potential, dissolved oxygen, specific conductance, and turbidity) stabilized fairly quickly. The total volume of water removed during purging was small (usually only a few liters), and did not appear to be related to either the casing volume or the screen volume of the well. This lack of correlation may indicate that a limited volume of the formation is sampled at the low flow rates. Since only a portion of long screened intervals appear to be sampled, care must be given to placement of the sample tubing to access zones where contaminant migration is expected. C1 Oak Ridge Natl Lab, Div Environm Sci, Oak Ridge, TN 37831 USA. Univ Nevada, Nevada Bur Mines & Geol, Reno, NV 89557 USA. RP McCarthy, J (reprint author), Oak Ridge Natl Lab, Div Environm Sci, POB 2008, Oak Ridge, TN 37831 USA. NR 29 TC 9 Z9 9 U1 0 U2 1 PU GROUND WATER PUBLISHING CO PI WESTERVILLE PA 601 DEMPSEY RD, WESTERVILLE, OH 43081 USA SN 0017-467X J9 GROUND WATER JI Ground Water PD MAR-APR PY 1998 VL 36 IS 2 BP 251 EP 260 DI 10.1111/j.1745-6584.1998.tb01090.x PG 10 WC Geosciences, Multidisciplinary; Water Resources SC Geology; Water Resources GA YZ695 UT WOS:000072281600013 ER PT J AU Davis, SN Whittemore, DO Fabryka-Martin, J AF Davis, SN Whittemore, DO Fabryka-Martin, J TI Uses of chloride/bromide ratios in studies of potable water SO GROUND WATER LA English DT Review ID MILK RIVER AQUIFER; HYDROTHERMAL FLUIDS; UNSATURATED SOIL; MICHIGAN BASIN; METHYL-BROMIDE; GROUNDWATER; GEOCHEMISTRY; CHEMISTRY; CANADA; TRANSPORT AB In natural ground water systems, both chlorine and bromine occur primarily as monovalent anions, chloride and bromide. Although dissolution or precipitation of halite, biological activity in the root zone, anion sorption, and exchange can affect chloride/bromide ratios in some settings, movement of the ions in potable ground water is most often conservative. Atmospheric precipitation will generally have mass ratios between 50 and 150; shallow ground water, between 100 and 200; domestic sewage, between 300 and 600; water affected by dissolution of halite, between 1000 and 10,000; and summer runoff from urban streets, between 10 and 100. These, and other distinctive elemental ratios, are useful in the reconstruction of the origin and movement of ground water, as illustrated by case studies investigating sources of salinity in ground water from Alberta, Kansas, and Arizona, and infiltration rates and pathways at Yucca Mountain, Nevada. C1 Univ Arizona, Dept Hydrol & Water Resources, Tucson, AZ 85721 USA. Univ Kansas, Kansas Geol Survey, Lawrence, KS 66047 USA. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Davis, SN (reprint author), Univ Arizona, Dept Hydrol & Water Resources, Tucson, AZ 85721 USA. RI Whittemore, Donald/M-8875-2015 OI Whittemore, Donald/0000-0003-1679-6675 NR 127 TC 229 Z9 235 U1 4 U2 41 PU GROUND WATER PUBLISHING CO PI WESTERVILLE PA 601 DEMPSEY RD, WESTERVILLE, OH 43081 USA SN 0017-467X J9 GROUND WATER JI Ground Water PD MAR-APR PY 1998 VL 36 IS 2 BP 338 EP 350 DI 10.1111/j.1745-6584.1998.tb01099.x PG 13 WC Geosciences, Multidisciplinary; Water Resources SC Geology; Water Resources GA YZ695 UT WOS:000072281600022 ER PT J AU Clement, TP Sun, Y Hooker, BS Petersen, JN AF Clement, TP Sun, Y Hooker, BS Petersen, JN TI Modeling multispecies reactive transport in ground water SO GROUND WATER MONITORING AND REMEDIATION LA English DT Article ID POROUS-MEDIA; BACTERIAL TRANSPORT; MICROBIAL-GROWTH; BIODEGRADATION; CONTAMINATION; DISTRIBUTIONS; HYDROCARBONS; SIMULATION; NUTRIENT; AQUIFER AB In this paper, the details of RT3D, a general purpose, multispecies, reactive transport code, are presented. The code uses MODFLOW to simulate flow and several MT3D sub-programs to simulate advection and dispersion. A set of reaction modules were developed and incorporated into RT3D to simulate various types of multispecies reactive transport. This new computer model can be used for analyzing different types of subsurface contaminant reactions, microbial metabolisms, and microbial transport kinetics. Details of the model and numerical solution procedure are presented. The numerical formulation of the code is general enough to allow description of any type of reaction with any number of mobile/immobile species. Several example problems are presented to test the performance of the code, and to illustrate its features. The presented numerical model is shown to be a useful tool for analyzing different types of subsurface bioremediation systems. Prediction based on this model can be used for screening remediation alternatives including natural attenuation and/or for forecasting contaminant exposure levels and environmental risks at sensitive, downgradient receptors. C1 Battelle Mem Inst, PNNL, Richland, WA 99352 USA. RP Clement, TP (reprint author), Battelle Mem Inst, PNNL, MS1N P7-41, Richland, WA 99352 USA. RI Petersen, James/B-8924-2008; Sun, Yunwei/C-9751-2010 NR 40 TC 152 Z9 152 U1 4 U2 28 PU GROUND WATER PUBLISHING CO PI WESTERVILLE PA 601 DEMPSEY RD, WESTERVILLE, OH 43081 USA SN 1069-3629 J9 GROUND WATER MONIT R JI Ground Water Monit. Remediat. PD SPR PY 1998 VL 18 IS 2 BP 79 EP 92 DI 10.1111/j.1745-6592.1998.tb00618.x PG 14 WC Water Resources SC Water Resources GA ZQ910 UT WOS:000073915300005 ER PT J AU Dorcas, ME Peterson, CR AF Dorcas, ME Peterson, CR TI Daily body temperature variation in free-ranging rubber boas SO HERPETOLOGICA LA English DT Article DE Charina bottae; body temperature; operative temperature; body temperature pattern; thermal utilization; thermal constraint; reproductive condition; activity; nocturnal activity; physical environment; radiotelemetry ID SCELOPORUS-MERRIAMI; GARTER SNAKES; THERMOREGULATION; PERFORMANCE; RATTLESNAKES; CONSTRAINTS; ECTOTHERMS; BEHAVIOR; LIZARDS; ECOLOGY AB A current generalization regarding body temperature (T-b) variation in free-ranging reptiles is that, when possible, they maintain relatively high T-b's to optimize important biological functions. However, because this generalization is based primarily on studies using opportunistic spot measurements of diurnal lizards, it is both phylogenetically and ecologically biased in addition to underrepresenting inactive animals. We addressed these problems by continually monitoring T-b variation in free-ranging rubber boas (Charina bottae), a nocturnal bold. We surgically implanted temperature sensitive radiotransmitters into 14 female snakes and monitored their T-b's at 5-min intervals for periods of up to a year (September 1990 to September 1992) using an automated monitoring system. Operative environmental temperatures (T-e's) were concurrently measured using physical snake models. We describe four daily T-b patterns, including a preciously undescribed pattern in which snakes were nocturnally active, frequently at unusually low temperatures (modal activity temperature = 14 C). Nocturnal activity occurred about once every eight days. As found in previous studies, pregnant snakes maintained higher and less variable T-b's than nonpregnant snakes, which is likely important for maintaining a high developmental rate. Our results also support findings from another study in which the thermal environment prevented snakes from maintaining high, stable T-b's much of the time. However, unlike precious studies, we found th;it when unconstrained by the thermal environment, snakes did not maintain high stable T-b's much of the time. These results raise questions regarding the predictability of reptilian thermoregulation using environmental temperatures. C1 Idaho State Univ, Dept Biol Sci, Pocatello, ID 83209 USA. RP Dorcas, ME (reprint author), Savannah River Ecol Lab, Drawer E, Aiken, SC 29802 USA. NR 53 TC 30 Z9 30 U1 1 U2 11 PU HERPETOLOGISTS LEAGUE PI JOHNSON CITY PA EAST TENNESSEE STATE UNIV, DEPT BIOLOGICAL SCIENCES, BOX 70726, JOHNSON CITY, TN 37614-0726 USA SN 0018-0831 J9 HERPETOLOGICA JI Herpetologica PD MAR PY 1998 VL 54 IS 1 BP 88 EP 103 PG 16 WC Zoology SC Zoology GA ZB722 UT WOS:000072501000009 ER PT J AU McCormick, PS Ahrens, JP AF McCormick, PS Ahrens, JP TI Visualization of wildfire simulations SO IEEE COMPUTER GRAPHICS AND APPLICATIONS LA English DT Editorial Material C1 Univ Calif Los Alamos Natl Lab, Adv Comp Lab, Los Alamos, NM 87545 USA. RP McCormick, PS (reprint author), Univ Calif Los Alamos Natl Lab, Adv Comp Lab, Mail Stop B287, Los Alamos, NM 87545 USA. NR 6 TC 3 Z9 3 U1 0 U2 1 PU IEEE COMPUTER SOC PI LOS ALAMITOS PA 10662 LOS VAQUEROS CIRCLE, PO BOX 3014, LOS ALAMITOS, CA 90720-1314 USA SN 0272-1716 J9 IEEE COMPUT GRAPH JI IEEE Comput. Graph. Appl. PD MAR-APR PY 1998 VL 18 IS 2 BP 17 EP 19 DI 10.1109/38.656785 PG 3 WC Computer Science, Software Engineering SC Computer Science GA YZ161 UT WOS:000072226400004 ER PT J AU Party, CPJ White, W Sibbett, W Trebino, R AF Party, CPJ White, W Sibbett, W Trebino, R TI Introduction to the issue on Ultrafast Optics SO IEEE JOURNAL OF SELECTED TOPICS IN QUANTUM ELECTRONICS LA English DT Editorial Material C1 Univ Calif San Diego, Inst Nonlinear Sci, La Jolla, CA 92093 USA. Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. Univ St Andrews, Dept Phys & Astron, St Andrews KY16 9TR, Fife, Scotland. Sandia Natl Labs, Combust Res Facil, Livermore, CA 94551 USA. RP Party, CPJ (reprint author), Univ Calif San Diego, Inst Nonlinear Sci, La Jolla, CA 92093 USA. NR 0 TC 1 Z9 1 U1 0 U2 2 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 1077-260X J9 IEEE J SEL TOP QUANT JI IEEE J. Sel. Top. Quantum Electron. PD MAR-APR PY 1998 VL 4 IS 2 BP 157 EP 158 PG 2 WC Engineering, Electrical & Electronic; Optics; Physics, Applied SC Engineering; Optics; Physics GA ZV019 UT WOS:000074260200001 ER PT J AU Kwok, A Jusinski, L Krumbugel, MA Sweetser, JN Fittinghoff, DN Trebino, R AF Kwok, A Jusinski, L Krumbugel, MA Sweetser, JN Fittinghoff, DN Trebino, R TI Frequency-resolved optical gating using cascaded second-order nonlinearities SO IEEE JOURNAL OF SELECTED TOPICS IN QUANTUM ELECTRONICS LA English DT Article; Proceedings Paper CT Meeting on Ultrafast Optics CY 1997 CL MONTEREY, CALIFORNIA DE femtosecond; frequency-resolved optical gating (FROG); ultrafast ID ULTRASHORT PULSES; GENERATION AB We demonstrate frequency-resolved optical gating (FROG) using cascaded second-order nonlinearities (up-conversion followed by down-conversion). We describe two different cascaded second-order beam geometries-self-diffraction and polarization-gate-which are identical to their third-order nonlinear-optical cousins, except that they use second-harmonic-generation crystals instead of (weaker) third-order materials. Like the corresponding third-order processes, these new versions of FROG yield the same intuitive traces, uniquely determine the pulse intensity and phase (without direction-of-time ambiguity), and yield signal light at the input-pulse wavelength (which simplifies the required spectral measurements). Most importantly, however, we show that these techniques are significantly more sensitive than the corresponding third-order FROG methods, conveniently allowing, for the first time, the unambiguous measurement of ultrashort similar to 1-nJ pulses, that is, unamplified Ti:sapphire oscillator pulses. C1 Sandia Natl Labs, Combust Res Facil, Livermore, CA 94550 USA. RP Kwok, A (reprint author), Sandia Natl Labs, Combust Res Facil, Livermore, CA 94550 USA. NR 10 TC 12 Z9 12 U1 2 U2 4 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 1077-260X J9 IEEE J SEL TOP QUANT JI IEEE J. Sel. Top. Quantum Electron. PD MAR-APR PY 1998 VL 4 IS 2 BP 271 EP 277 DI 10.1109/2944.686732 PG 7 WC Engineering, Electrical & Electronic; Optics; Physics, Applied SC Engineering; Optics; Physics GA ZV019 UT WOS:000074260200015 ER PT J AU Cha, YS Yang, ZJ Turner, LR Poeppel, RB AF Cha, YS Yang, ZJ Turner, LR Poeppel, RB TI Analysis of a passive superconducting fault current limiter SO IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY LA English DT Article DE fault current limiters; noninductively wound superconductor coils; superconductors ID PERFORMANCE AB An analysis was carried out to predict the forced response of the equivalent circuit of an innovative superconducting fault current limiter (FCL), The FCE employs two superconducting coils with differing critical currents wound noninductively. The analysis shows that to reduce the voltage drop under normal operating conditions, the coupling coefficient should be kept fairly high (k > 0.90), For a given coil configuration (omega L = constant), the limiting capability of the device increases with the resistance R of the trigger coil up to a certain value of R, then further increase in R changes very little the limiting capability of the FCL. However, further increase in R can reduce the heat generation rate in the device which will help alleviate the problem of relatively long recovery time. The fault current predicted from estimated values of R compares fairly well with results of an experiment reported in the Literature, The discrepancy between the predicted and measured current is due mainly to the uncertainty In the estimated resistance R, because both the purity of Cn and the percentage of Cu in CuNi are neat known. By varying the ratio of NbTi-Cu-CuNi in the matrix, the purity of Co, and the percentage of Cn in CuNi various values of R, can be achieved, which should help to alleviate the problem off excessive Joule heating and recovery time. C1 Argonne Natl Lab, Div Energy Technol, Argonne, IL 60439 USA. Lucent Technol, Naperville, IL 60566 USA. RP Cha, YS (reprint author), Argonne Natl Lab, Div Energy Technol, 9700 S Cass Ave, Argonne, IL 60439 USA. NR 15 TC 5 Z9 5 U1 0 U2 2 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 1051-8223 J9 IEEE T APPL SUPERCON JI IEEE Trans. Appl. Supercond. PD MAR PY 1998 VL 8 IS 1 BP 20 EP 25 DI 10.1109/77.662690 PG 6 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA ZC985 UT WOS:000072639200004 ER PT J AU Sochen, N Kimmel, R Malladi, R AF Sochen, N Kimmel, R Malladi, R TI A general framework for low level vision SO IEEE TRANSACTIONS ON IMAGE PROCESSING LA English DT Article DE color image processing; image enhancement; image smoothing; nonlinear image diffusion; scale-space ID PRESCRIBED MEAN-CURVATURE; EVOLUTIONARY SURFACES; ANISOTROPIC DIFFUSION; SCALE-SPACE; IMAGE AB We introduce a new geometrical framework based on which natural flows for image scale space and enhancement are presented, We consider intensity images as surfaces in the (x.I) space, The image is, thereby, a two-dimensional (2-D) surface in three-dimensional (3-D) space for gray-level images, and 2-D surfaces in five dimensions for color images. The new formulation unifies many classical schemes and algorithms via a simple scaling of the intensity contrast, and results in new and efficient schemes, Extensions to multidimensional signals become natural and lead to powerful deionising and scale space algorithms. C1 Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Math, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Tel Aviv Univ, Sch Phys & Astron, IL-69978 Tel Aviv, Israel. EM ron@math.lbl.gov; malladi@math.lbl.gov NR 45 TC 367 Z9 384 U1 0 U2 8 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855-4141 USA SN 1057-7149 EI 1941-0042 J9 IEEE T IMAGE PROCESS JI IEEE Trans. Image Process. PD MAR PY 1998 VL 7 IS 3 BP 310 EP 318 DI 10.1109/83.661181 PG 9 WC Computer Science, Artificial Intelligence; Engineering, Electrical & Electronic SC Computer Science; Engineering GA YY931 UT WOS:000072202300006 PM 18276251 ER PT J AU Apte, MG Nero, AV Revzan, KL AF Apte, MG Nero, AV Revzan, KL TI Meteorological database for the United States SO INDOOR AIR-INTERNATIONAL JOURNAL OF INDOOR AIR QUALITY AND CLIMATE LA English DT Article DE meteorology; infiltration degree days; indoor air quality; database; modeling; radon; US; World Wide Web ID RADON CONCENTRATIONS; MINNESOTA; HOMES AB A meteorological database for the 48 contiguous states of the United States has been developed for use in indoor air pollution predictive models. The database contains predicted typical monthly meteorological statistics at the county level derived from hourly meteorological data from 208 (234 for precipitation) geographically distinct monitoring stations. Interpolation and extrapolation techniques were used to predict statistics for counties not containing a meteorological monitoring site. The LBNL database includes statistics for meteorological variables including dry-bulb temperature, dew-point temperature, barometric pressure, wind speed, wind direction, hours of precipitation, precipitation, and derived infiltration degree-days. The database consists of individual files of derived statistics for each weather variable and is potentially useful for indoor radon modeling as well as for other purposes. Each file contains data values for all 12 months and an aggregation of the 12 months up to a yearly statistic for all county centroids. A test was conducted to assess the quality of interpolated values. Examples showing the use of the database for mapping infiltration degree-days and an application of the database to a statistical correlation analysis attempting to find meteorological factors influencing indoor radon levels in the United States are discussed. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Indoor Environm Program, Berkeley, CA 94720 USA. RP Apte, MG (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Indoor Environm Program, Berkeley, CA 94720 USA. NR 13 TC 3 Z9 3 U1 0 U2 3 PU MUNKSGAARD INT PUBL LTD PI COPENHAGEN PA 35 NORRE SOGADE, PO BOX 2148, DK-1016 COPENHAGEN, DENMARK SN 0905-6947 J9 INDOOR AIR JI Indoor Air-Int. J. Indoor Air Qual. Clim. PD MAR PY 1998 VL 8 IS 1 BP 61 EP 67 DI 10.1111/j.1600-0668.1998.t01-2-00008.x PG 7 WC Construction & Building Technology; Engineering, Environmental; Public, Environmental & Occupational Health SC Construction & Building Technology; Engineering; Public, Environmental & Occupational Health GA ZD465 UT WOS:000072688700007 ER PT J AU Chaiko, DJ Kopasz, JP Ellison, AJG AF Chaiko, DJ Kopasz, JP Ellison, AJG TI Use of sol-gel systems for solid/liquid separation SO INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH LA English DT Article AB A unique approach using sol-gel technology is presented for separating and recovering particulates and colloids from caustic waste slurries. The approach involves the addition of an alkali silicate and an organic gelling agent directly to the waste stream to immobilize particulates that range from macro sizes to submicron colloids. The particulates and colloids become trapped within a silica network that remains porous during the early stages of the sol-gel process. The freshly gelled monolith undergoes a process of syneresis, whereby the water and soluble salts are ejected from the monolith as it contracts. The approach has been illustrated by removal of ultrafine particulates from a Hanford Tank Waste simulant. Initial laboratory tests have shown that it is possible to produce silica monoliths in the presence of 4 M hydroxide. Analysis of the mother liquor produced during syneresis indicated quantitative recovery of the particulates within the monolith. The partitioning of ions between the silica gel and the mother liquor during syneresis correlates directly with the lyotropic series. Salt recoveries from the mother liquor in excess of 90% can be achieved. With a capability of recovering >99.999% of all particulates, including colloids, the process is more efficient than membrane filtration. This approach produces a rock-hard silica monolith that can be used directly as a feedstock to a-glass melter or can be consolidated to near theoretical density by sintering. C1 Argonne Natl Lab, Div Chem Technol, Argonne, IL 60439 USA. RP Chaiko, DJ (reprint author), Argonne Natl Lab, Div Chem Technol, 9700 S Cass Ave, Argonne, IL 60439 USA. NR 28 TC 4 Z9 4 U1 0 U2 4 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0888-5885 J9 IND ENG CHEM RES JI Ind. Eng. Chem. Res. PD MAR PY 1998 VL 37 IS 3 BP 1071 EP 1078 DI 10.1021/ie970502u PG 8 WC Engineering, Chemical SC Engineering GA ZA689 UT WOS:000072391200044 ER PT J AU Hutzler, MJ AF Hutzler, MJ TI Untitled SO INTERFACES LA English DT Editorial Material C1 US DOE, Energy Informat Adm, Off Integrated Anal & Forecasting, Washington, DC 20585 USA. RP Hutzler, MJ (reprint author), US DOE, Energy Informat Adm, Off Integrated Anal & Forecasting, Washington, DC 20585 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU INST OPERATIONS RESEARCH MANAGEMENT SCIENCES PI LINTHICUM HTS PA 901 ELKRIDGE LANDING RD, STE 400, LINTHICUM HTS, MD 21090-2909 USA SN 0092-2102 J9 INTERFACES JI Interfaces PD MAR-APR PY 1998 VL 28 IS 2 BP 15 EP 15 PG 1 WC Management; Operations Research & Management Science SC Business & Economics; Operations Research & Management Science GA ZP589 UT WOS:000073768600002 ER PT J AU Shastry, V Farkas, D AF Shastry, V Farkas, D TI Atomistic simulation of fracture in CoAl and FeAl SO INTERMETALLICS LA English DT Article DE aluminides; miscellaneous; iron aluminides based on FeAl; fracture mode; simulations; acoustic ID DISLOCATION AB The behavior of mode I cracks in CoAl and FeAl is investigated using molecular statics computer simulation methods with embedded atom (EAM) potentials developed by Vailhe and Farkas (not yet published). A double ended crack of finite size embedded in a cylindrical simulation cell and fixed boundary conditions are prescribed along the periphery of the cell, whereas periodic boundary conditions are imposed parallel to the crack front. The displacement field of the finite crack is represented by that of an equivalent pileup of opening dislocations distributed in a manner consistent with the anisotropy of the crystal and traction free conditions of the crack faces. The crack lies on the {110} plane and the crack front is located either along [100], [110] or [111] directions. Cleavage in found to occur in both materials for most crack orientations. In one orientation, cleavage in FeAl is found to occur concurrently with dislocation emission. The crack tip response is rationalized in terms of the surface energy (gamma(s)) of the cleavage plane and the unstable stacking energies (gamma(us)) of the slip planes emanating from the crack front. (C) 1997 Elsevier Science Limited. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. Virginia Polytech Inst & State Univ, Dept Mat Sci & Engn, Blacksburg, VA 24061 USA. RP Shastry, V (reprint author), Univ Calif Lawrence Livermore Natl Lab, POB 808,MS L-268, Livermore, CA 94551 USA. NR 8 TC 8 Z9 9 U1 0 U2 2 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0966-9795 J9 INTERMETALLICS JI Intermetallics PD MAR PY 1998 VL 6 IS 2 BP 95 EP 104 DI 10.1016/S0966-9795(97)00048-4 PG 10 WC Chemistry, Physical; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Chemistry; Materials Science; Metallurgy & Metallurgical Engineering GA YV110 UT WOS:000071790400002 ER PT J AU Wang, ZM Wei, C Feng, Q Whang, SH Allard, LF AF Wang, ZM Wei, C Feng, Q Whang, SH Allard, LF TI Superdislocations and their relative stability single crystal Ti-56Al deformed at 573 K SO INTERMETALLICS LA English DT Article DE titanium aluminides; TiAl; defects, dislocation geometry and arrangement ID STRESSES AB The core configurations of [(1) over bar 01] superdislocations in single crystal Ti-56Al have been investigated by high resolution electron microscopy. The results show that the dissociated superpartial dislocations in deformed Ti-56Al at 573 K adapt two different configurations: (1) coplanar dissociation; and (2) rooftop type dissociation in which each coupling superpartial (1/2[(1) over bar 01]) lies in two different {111} slip planes. The rooftop configuration appears to be formed by a thermally activated process and provides the pinning of gliding superdislocations at this temperature. The calculated elastic interaction energy between the coupling superpartial dislocations in the anisotropic medium shows that the rooftop configuration has lower interaction energy than that of the coplanar configuration. Based the observation and theoretical calculations, a model based on partial cross slip and its reversal is proposed for the anomalous hardening in the range of RT-650 K. (C) 1997 Elsevier Science Limited. C1 Polytech Univ, Brooklyn, NY 11201 USA. Oak Ridge Natl Lab, High Temp Mat Lab, Oak Ridge, TN 37831 USA. RP Wang, ZM (reprint author), Polytech Univ, 6 Metrotech Ctr, Brooklyn, NY 11201 USA. NR 14 TC 5 Z9 5 U1 0 U2 1 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0966-9795 J9 INTERMETALLICS JI Intermetallics PD MAR PY 1998 VL 6 IS 2 BP 131 EP 139 DI 10.1016/S0966-9795(97)00056-3 PG 9 WC Chemistry, Physical; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Chemistry; Materials Science; Metallurgy & Metallurgical Engineering GA YV110 UT WOS:000071790400006 ER PT J AU Miller, JA Melius, CF Glarborg, P AF Miller, JA Melius, CF Glarborg, P TI The CH3+NO rate coefficient at high temperatures: Theoretical analysis and comparison with experiment SO INTERNATIONAL JOURNAL OF CHEMICAL KINETICS LA English DT Article ID COMBUSTION; NO AB Using stationary-point information from a BAC-MP4 potential-energy surface and statistical-dynamical methods, we have calculated the total rate coefficient for the two-channel reaction, [GRAPHICS] in the temperature range 1000 K greater than or equal to T greater than or equal to 2500 K. The result obtained, k(T) = 3.0 x 10(-1)T(3.52)exp(-3950/RT) cm(3)/mole s, is in excellent agreement with recent shock-tube measurements of k(T) by Braun-Unkhoff, et al. and Hennig and Wagner. Qualitative considerations suggest that the radical channel (R2) is dominant in this temperature range. The analysis and the results are discussed in some detail. (C) 1998 John Wiley & Sons, Inc. C1 Sandia Natl Labs, Combust Res Facil, Livermore, CA 94551 USA. Tech Univ Denmark, Dept Chem Engn, DK-2800 Lyngby, Denmark. RP Miller, JA (reprint author), Sandia Natl Labs, Combust Res Facil, Livermore, CA 94551 USA. NR 23 TC 14 Z9 14 U1 1 U2 4 PU JOHN WILEY & SONS INC PI NEW YORK PA 605 THIRD AVE, NEW YORK, NY 10158-0012 USA SN 0538-8066 J9 INT J CHEM KINET JI Int. J. Chem. Kinet. PD MAR PY 1998 VL 30 IS 3 BP 223 EP 228 DI 10.1002/(SICI)1097-4601(1998)30:3<223::AID-KIN8>3.0.CO;2-U PG 6 WC Chemistry, Physical SC Chemistry GA YZ563 UT WOS:000072266600008 ER PT J AU Curran, HJ Pitz, WJ Westbrook, CK Dagaut, P Boettner, JC Cathonnet, M AF Curran, HJ Pitz, WJ Westbrook, CK Dagaut, P Boettner, JC Cathonnet, M TI A wide range modeling study of dimethyl ether oxidation SO INTERNATIONAL JOURNAL OF CHEMICAL KINETICS LA English DT Article ID GAS-PHASE; CH3OCH2O2 RADICALS; HYDROXYL RADICALS; ALIPHATIC ETHERS; RATE CONSTANTS; KINETIC DATA; TEMPERATURE; PYROLYSIS; HYDROGEN; PRESSURE AB A detailed chemical kinetic model has been used to study dimethyl ether (DME) oxidation over a wide range of conditions. Experimental results obtained in a jet-stirred reactor (JSR) at 1 and 10 atm, 0.2 less than or equal to phi less than or equal to 2.5, and 800 less than or equal to T less than or equal to 1300 K were modeled, in addition to those generated in a shock tube at 13 and 40 bar, phi = 1.0 and 650 less than or equal to T 1300 K. The JSR results are particularly valuable as they include concentration profiles of reactants, intermediates, and products pertinent to the oxidation of DME. These data test the kinetic model severely, as it must be able to predict the correct distribution and concentrations of intermediate and final products formed in the oxidation process. Additionally, the shock-tube results are very useful, as they were taken at low temperatures and at high pressures, and thus undergo negative temperature dependence (NTC) behavior. This behavior is characteristic of the oxidation of saturated hydrocarbon fuels, (e.g., the primary reference fuels, n-heptane and iso-octane) under similar conditions. The numerical model consists of 78 chemical species and 336 chemical reactions. The thermodynamic properties of unknown species pertaining to DME oxidation were calculated using THERM. (C) 1998 John Wiley & Sons, Inc. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. CNRS, Lab Combust & Syst React, F-45071 Orleans 2, France. RP Curran, HJ (reprint author), Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RI Dagaut, Philippe/C-1709-2008; OI Dagaut, Philippe/0000-0003-4825-3288; Curran, Henry/0000-0002-5124-8562 NR 51 TC 184 Z9 200 U1 6 U2 47 PU JOHN WILEY & SONS INC PI NEW YORK PA 605 THIRD AVE, NEW YORK, NY 10158-0012 USA SN 0538-8066 J9 INT J CHEM KINET JI Int. J. Chem. Kinet. PD MAR PY 1998 VL 30 IS 3 BP 229 EP 241 DI 10.1002/(SICI)1097-4601(1998)30:3<229::AID-KIN9>3.0.CO;2-U PG 13 WC Chemistry, Physical SC Chemistry GA YZ563 UT WOS:000072266600009 ER PT J AU Baker, WE Togami, TC Weydert, JC AF Baker, WE Togami, TC Weydert, JC TI Static and dynamic properties of high-density metal honeycombs SO INTERNATIONAL JOURNAL OF IMPACT ENGINEERING LA English DT Article AB Metal honeycombs are commonly used to absorb energy in applications involving impact because of their high-energy capacity to weight ratio. The energy capacity of a material will be affected by any strain-rate effect in the material; thus knowledge of this property is necessary for design purposes. The materials studied in this work were a thick-walled aluminum and stainless-steel honeycomb. A method of testing the specimens in a state approximating uniaxial strain was developed for the large compressive deformations required with honeycombs, and used For both static and dynamic tests. For the dynamic rests, a gas gun was used to propel projectiles into fixed specimens of the test materials, and measurements of the force at the fixed ends of the specimens were used to determine the energy absorption properties of the materials. Initial strain rates to about 2000/s were obtained. Both materials showed a strain-rate effect. (C) 1998 Elsevier Science Ltd. All rights reserved. C1 Univ New Mexico, Dept Mech Engn, Albuquerque, NM 87131 USA. Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Baker, WE (reprint author), Univ New Mexico, Dept Mech Engn, Albuquerque, NM 87131 USA. NR 8 TC 60 Z9 65 U1 0 U2 7 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0734-743X J9 INT J IMPACT ENG JI Int. J. Impact Eng. PD MAR PY 1998 VL 21 IS 3 BP 149 EP 163 DI 10.1016/S0734-743X(97)00040-7 PG 15 WC Engineering, Mechanical; Mechanics SC Engineering; Mechanics GA ZF697 UT WOS:000072923000003 ER PT J AU Groenewold, GS Gianotto, AK Olson, JE Appelhans, AD Ingram, JC Delmore, JE Shaw, AD AF Groenewold, GS Gianotto, AK Olson, JE Appelhans, AD Ingram, JC Delmore, JE Shaw, AD TI Static SIMS investigation of tetraethylammonium bromide on soil particles using ReO4- and Ga+ projectiles SO INTERNATIONAL JOURNAL OF MASS SPECTROMETRY LA English DT Article DE tetraethylammonium bromide; SIMS; soil particles; disappearance cross section; polyatomic projectile ID ION MASS-SPECTROMETRY; ENVIRONMENTAL SURFACES; TRIBUTYL-PHOSPHATE; LEAF SURFACES; IONIZATION; MATRIX; EMISSION; ENERGY; ACIDS AB Tetraethylammonium (TEN+) adsorbed to soil particles (primarily silicate) was investigated using static secondary ion mass spectrometry (SIMS) in order to assess the behavior of the adsorbate under atomic and polyatomic projectile bombardment. Three different instruments were used for the investigation: a quadrupole-SIMS instrument equipped with a ReO4- primary ion gun; an ion trap SIMS instrument equipped with ReO4-; and an imaging time-of-flight (ToF) SIMS equipped with Ga+. In all experiments, TEN+ was observed to decrease in abundance with increasing primary ion dose. The disappearance cross-section (sigma(130)) for intact TEN+ (m/z 130), induced by ReO4-, was measured at 670 Angstrom(2) using the quadrupole, and 560 Angstrom(2) using the ion trap. The sigma(130) induced by Ga+ was measured at 450 Angstrom(2) using the ToF-SIMS, indicating that the polyatomic projectile was perturbing an area 20-50% larger than the monoatomic. These values are significantly larger than Ga+-induced cross-sections in the literature (100-200 Angstrom(2)), for similar compounds in a more fluid matrix (gelatin). The comparison was extended by measuring the cross-section using ReO4- projectiles and a gelatin matrix: sigma(130) in this case was 480 Angstrom(2), which is of the order of 150% greater than the same experiment using Ga+. It is concluded that Real produces a larger a than does Ga+. In addition, the results suggest that disappearance cross-sections are larger on a refractory solid surface (silicate), than they are on a fluid surface (gelatin). The minimum detection limit was estimated for TEN+ on soil using ReO4- with the quadrupole SIMS instrument, at approximately 5 x 10(-4) monolayers (ML), which corresponds to about 500 ppb. Consideration of this result suggests that a lower detection limit may be achievable using a brighter primary ion beam together with a trapped ion mass spectrometer. (C) 1998 Elsevier Science B.V. C1 EG&G Idaho Inc, Idaho Natl Engn Lab, Idaho Falls, ID 83415 USA. Westminster Christian Acad, St Louis, France. RP Groenewold, GS (reprint author), EG&G Idaho Inc, Idaho Natl Engn Lab, POB 1625, Idaho Falls, ID 83415 USA. NR 34 TC 24 Z9 24 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 1387-3806 J9 INT J MASS SPECTROM JI Int. J. Mass Spectrom. PD MAR PY 1998 VL 174 IS 1-3 BP 129 EP 142 DI 10.1016/S0168-1176(97)00296-6 PG 14 WC Physics, Atomic, Molecular & Chemical; Spectroscopy SC Physics; Spectroscopy GA ZK282 UT WOS:000073303600012 ER PT J AU Tsekouras, AA Iedema, MJ Ellison, GB Cowin, JP AF Tsekouras, AA Iedema, MJ Ellison, GB Cowin, JP TI Soft-landed ions: a route to ionic solution studies SO INTERNATIONAL JOURNAL OF MASS SPECTROMETRY LA English DT Article DE soft-land ions; ionic solution studies; condensed phase ID WATER; DYNAMICS AB Solvated ions in condensed phase can be studied with new directness, using a very low energy(less than or equal to 1 eV) mass-selected ion source, to 'soft-land' ions on or within surface films. The very low energy allows almost any ion to be studied without impact damage. Results for hydronium ions deposited on water ice are presented, where the lack of hydronium diffusion up to 190 K is evident, and intriguing information on dielectric behavior is measured. Cs+ ions moving in n-hexane and 3-methyl pentane are also discussed. (C) 1998 Elsevier Science B.V. C1 Pacific NW Lab, Environm Mol Sci Lab, Richland, WA 99352 USA. Univ Colorado, Dept Chem & Biochem, Boulder, CO 80309 USA. RP Cowin, JP (reprint author), Pacific NW Lab, Environm Mol Sci Lab, POB 999, Richland, WA 99352 USA. OI Tsekouras, Athanassios/0000-0002-4757-324X NR 18 TC 23 Z9 23 U1 1 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 1387-3806 J9 INT J MASS SPECTROM JI Int. J. Mass Spectrom. PD MAR PY 1998 VL 174 IS 1-3 BP 219 EP 230 DI 10.1016/S0168-1176(97)00303-0 PG 12 WC Physics, Atomic, Molecular & Chemical; Spectroscopy SC Physics; Spectroscopy GA ZK282 UT WOS:000073303600018 ER PT J AU Chadha, M Capala, J Coderre, JA Elowitz, EH Iwai, J Joel, DD Liu, HYB Wielopolski, L Chanana, AD AF Chadha, M Capala, J Coderre, JA Elowitz, EH Iwai, J Joel, DD Liu, HYB Wielopolski, L Chanana, AD TI Boron neutron-capture therapy (BNCT) for glioblastoma multiforme (GBM) using the epithermal neutron beam at the Brookhaven National Laboratory SO INTERNATIONAL JOURNAL OF RADIATION ONCOLOGY BIOLOGY PHYSICS LA English DT Article; Proceedings Paper CT 38th Annual Meeting of American-Society-for-Therapeutic-Radiology-and-Oncology CY OCT 26-30, 1996 CL LOS ANGELES, CALIFORNIA SP Amer Soc Therapeut Radiol & Oncol DE boron neutron capture therapy; glioblastoma multiforme; epithermal neutrons; p-boronophenylalanine-fructose ID HIGH-GRADE GLIOMAS; PARA-BORONOPHENYLALANINE; RADIATION-THERAPY; BRAIN; PHARMACOKINETICS; BIODISTRIBUTION; RADIOTHERAPY; SULFHYDRYL; COMPLEX; TUMORS AB Objective: Boron neutron-capture therapy (BNCT) is a binary form of radiation therapy based on the nuclear reactions that occur when boron (B-10) is exposed to thermal neutrons. Preclinical studies have demonstrated the therapeutic efficacy of p-boronophenylalanine (EPA)-based BNCT. The objectives of the Phase I/II trial were to study the feasibility and safety of single-fraction BNCT in patients with GEM. Materials and Methods: The trial design required (a) a BPA biodistribution study performed at the time of craniotomy; and (b) BNCT within approximate to 4 weeks of the biodistribution study. From September 1993 to July 1995, 10 patients were treated. For biodistribution, patients received a 2-hour intravenous (i.v.) infusion of BPA-fructose complex (BPA-F). Blood samples, taken during and after infusion, and multiple tissue samples collected during surgical debulking were analyzed for B-10 concentration. For BNCT, all patients received a dose of 250 mg BPA/kg administered by a 2-hour i.v. infusion of BPA-F, followed by neutron beam irradiation at the Brookhaven Medical Research Reactor (BMRR). The average blood B-10 concentrations measured before and during treatment mere used to calculate the time of reactor irradiation that would deliver the prescribed dose. Results: B-10 concentrations in specimens of scalp and tumor were higher than in blood by factors of approximate to 1.5 and approximate to 3.5, respectively. The B-10 concentration in the normal brain was less than or equal to that in the blood; however, for purposes of estimating radiation doses to normal brain endothelium, it was always assumed to be equal to blood. BNCT doses are expressed as gray-equivalent (Gy-Eq), which is the sum of the various physical dose components multiplied to appropriate biologic effectiveness factors. The dose to a 1-cm(3) volume where the thermal flux reached a maximum was 10.6 +/- 0.3 Gy-Eq in 9 patients and 13.8 Gy-Eq in 1 patient. The minimum dose in tumor ranged from 20 to 32.3 Gy-Eq. The minimum dose in the target volume (tumor plus 2 cm margin) ranged from 7.8 to 16.2 Gy-Eq. Dose to scalp ranged from 10 to 16 Gy-Eq. All patients experienced in-field alopecia. No CNS toxicity attributed to BNCT was observed. The median time to local disease progression following BNCT was 6 months (range 2.7 to 9.0). The median time to local disease progression was longer in patients who received a higher tumor dose. The median survival time from diagnosis was 13.5 months. Conclusion: It is feasible to safely deliver a single fraction of BPA-based BNCT. At the dose prescribed, the patients did not experience any morbidity. To further evaluate the therapeutic efficacy of BNCT, a dose-escalation study delivering a minimum target volume dose of 17 Gy-Eq is in progress. (C) 1998 Elsevier Science Inc. C1 Beth Israel Med Ctr, Dept Radiat Oncol, Beth Israel Hlth Care Syst, New York, NY 10003 USA. Beth Israel Med Ctr, Dept Neurosurg, Beth Israel Hlth Care Syst, New York, NY 10003 USA. Brookhaven Natl Lab, Dept Med, Upton, NY 11973 USA. RP Chadha, M (reprint author), Beth Israel Med Ctr, Dept Radiat Oncol, Beth Israel Hlth Care Syst, 10 Union Sq E, New York, NY 10003 USA. NR 32 TC 65 Z9 66 U1 0 U2 4 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0360-3016 J9 INT J RADIAT ONCOL JI Int. J. Radiat. Oncol. Biol. Phys. PD MAR 1 PY 1998 VL 40 IS 4 BP 829 EP 834 DI 10.1016/S0360-3016(97)00891-2 PG 6 WC Oncology; Radiology, Nuclear Medicine & Medical Imaging SC Oncology; Radiology, Nuclear Medicine & Medical Imaging GA ZC991 UT WOS:000072639900011 PM 9531367 ER PT J AU Pitzer, KS AF Pitzer, KS TI Aqueous electrolytes at near-critical and supercritical temperatures SO INTERNATIONAL JOURNAL OF THERMOPHYSICS LA English DT Article; Proceedings Paper CT 13th Symposium on Thermophysical Properties CY JUN 22-27, 1997 CL UNIV COLORADO, BOULDER, COLORADO SP Amer Soc Mech Engineers, Heat Transfer Div, Standing Comm Thermophys Properties, Natl Inst Stand & Technol, Chem Sci & Technol Lab, Phys & Chem Properties Div HO UNIV COLORADO DE aqueous electrolytes; calcium chloride; equation of state; near-critical properties; phase-diagram type; potassium chloride; sodium chloride; supercritical properties ID THERMODYNAMIC PERTURBATION-THEORY; DIPOLAR HARD SPHERES; SIMPLE POLAR FLUIDS; PHASE-EQUILIBRIA; VOLUMETRIC PROPERTIES; STATE REPRESENTATION; SODIUM-CHLORIDE; CRITICAL LINES; IONIC FLUIDS; MONTE-CARLO AB The aqueous electrolyte systems NaCl-H2O, KCl-H2O, and CaCl2-H2O are of great interest both geologically and industrially. Equations of state were developed recently for these systems; they are based on theoretical modeling for mixtures of hard spheres with appropriate diameters and dipole moments for H2O, NaCl, and KCl and with a quadrupole moment for CaCl2. Empirical terms are added as required to fit the available experimental data. The fit to the compositions and densities at equilibrium of the saturated vapor and liquid constitutes a severe test, in addition to properties in the single-phase regions. Temperatures range upward from 300 degrees C for NaCl and KCl and from 250 degrees C for CaCl2 for these equations. Complications from hydrolysis and alternate equations valid at lower temperatures are discussed briefly. In addition, there is a very important theoretical aspect relating to the general phase diagrams. With the high ratio of critical temperatures of the salts to that of water, complex diagrams involving liquid-liquid phase separation near the critical point of water are expected. But no such effect is observed experimentally; instead, one finds simple type I phase diagrams. This is particularly clear in the case of NaCl-H2O, where the database is very accurate and extends above 1000 K. C1 Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Pitzer, KS (reprint author), Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. NR 36 TC 11 Z9 11 U1 1 U2 5 PU PLENUM PUBL CORP PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 0195-928X J9 INT J THERMOPHYS JI Int. J. Thermophys. PD MAR PY 1998 VL 19 IS 2 BP 355 EP 366 DI 10.1023/A:1022549024247 PG 12 WC Thermodynamics; Chemistry, Physical; Mechanics; Physics, Applied SC Thermodynamics; Chemistry; Mechanics; Physics GA ZY912 UT WOS:000074675100003 ER PT J AU Cui, ST Cummings, PT Cochran, HD Moore, JD Gupta, SA AF Cui, ST Cummings, PT Cochran, HD Moore, JD Gupta, SA TI Nonequilibrium molecular dynamics simulation of the rheology of linear and branched alkanes SO INTERNATIONAL JOURNAL OF THERMOPHYSICS LA English DT Article; Proceedings Paper CT 13th Symposium on Thermophysical Properties CY JUN 22-27, 1997 CL UNIV COLORADO, BOULDER, COLORADO SP Amer Soc Mech Engineers, Heat Transfer Div, Standing Comm Thermophys Properties, Natl Inst Stand & Technol, Chem Sci & Technol Lab, Phys & Chem Properties Div HO UNIV COLORADO DE alkanes; nonequilibrium molecular dynamics; order tensor; rheology; shear thinning; viscosity; viscosity index ID NORMAL-DECANE; HEXADECANE; FLUIDS AB Liquid alkanes in the molecular weight range of C-20-C-40 are the main constituents of lubricant basestocks, and their rheological properties are therefore of great concern in industrial lubricant applications. Using massively parallel supercomputers and an efficient parallel algorithm, we have carried out systematic studies of the rheological properties of a variety of model liquid alkanes ranging from linear to singly branched and multiply branched alkanes. We aim to elucidate the relationship between the molecular architecture and the viscous behavior. Nonequilibrium molecular dynamics simulations have been carried out for n-decane (C10H22), n-hexadecane (C16H34), n-tetracosane (C24H50), 10-n-hexylnonadecane (C25H52), and squalane (2, 6, 10, 15, 19, 23-hexamethyltetracosane, C-30 H-62). At a high strain rate, the viscosity shows a power-law shear thinning behavior over several orders of magnitude in strain rate, with exponents ranging from - 0.33 to - 0.59. This power-law sheer thinning is shown to be closely related to the ordering of the molecules. The molecular architecture is shown to have a significant influence on the power-law exponent. At a low strain rate, the viscosity behavior changes to a Newtonian plateau, whose accurate determination has been elusive in previous studies. The molecular order in this regime is essentially that of the equilibrium system, a signature of the linear response. The Newtonian plateau is verified by independent equilibrium molecular dynamics simulations using the Green-Kubo method. The reliable determination of the Newtonian viscosity from nonequilibrium molecular simulation permits us to calculate the viscosity index for squalane. The viscosity index is a widely used property to characterize the lubricant's temperature performance, and our studies represent the first approach toward its determination by molecular simulation. C1 Univ Tennessee, Dept Chem Engn, Knoxville, TN 37996 USA. Oak Ridge Natl Lab, Div Chem Technol, Oak Ridge, TN 37831 USA. RP Cui, ST (reprint author), Univ Tennessee, Dept Chem Engn, Knoxville, TN 37996 USA. RI Moore, Jonathan/B-8201-2009; Cummings, Peter/B-8762-2013 OI Cummings, Peter/0000-0002-9766-2216 NR 28 TC 28 Z9 28 U1 1 U2 15 PU PLENUM PUBL CORP PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 0195-928X J9 INT J THERMOPHYS JI Int. J. Thermophys. PD MAR PY 1998 VL 19 IS 2 BP 449 EP 459 DI 10.1023/A:1022565427881 PG 11 WC Thermodynamics; Chemistry, Physical; Mechanics; Physics, Applied SC Thermodynamics; Chemistry; Mechanics; Physics GA ZY912 UT WOS:000074675100011 ER PT J AU Mang, JT Hjelm, RP AF Mang, JT Hjelm, RP TI Small-angle neutron scattering studies of vesicle stability SO INTERNATIONAL JOURNAL OF THERMOPHYSICS LA English DT Article; Proceedings Paper CT 13th Symposium on Thermophysical Properties CY JUN 22-27, 1997 CL UNIV COLORADO, BOULDER, COLORADO SP Amer Soc Mech Engineers, Heat Transfer Div, Standing Comm Thermophys Properties, Natl Inst Stand & Technol, Chem Sci & Technol Lab, Phys & Chem Properties Div HO UNIV COLORADO DE small-angle neutron scattering; stability; vesicles ID MEMBRANE; SHAPE; BILE AB Small-angle neutron scattering (SANS) was used to investigate the structure of mixed colloids of egg yolk phosphatidylcholine (EYPC) with the bile salt, cholylglycine (CG), in D2O as a function of pressure (P) and temperature (T). At atmospheric pressure, the system forms an isotropic phase of mixed, single bilayer vesicles (SLVs). Increasing the external hydrostatic pressure brought about significant changes in particle morphology. At T = 25 degrees C, application of a pressure of 3.5 MPa resulted in collapse of the SLVs. A further increase in P, up to 51.8 MPa, resulted in a transition from a phase of ordered (stacked), collapsed vesicles to one of stacked, ribbon-like particles. A similar collapse of the vesicles was observed at a higher temperature (T = 37 degrees C) with increasing P, but at this temperature, no ribbon phase was found at the highest pressure explored. C1 Univ Calif Los Alamos Natl Lab, Manuel Lujan Jr Neutron Scattering Ctr, Los Alamos, NM 87545 USA. RP Hjelm, RP (reprint author), Univ Calif Los Alamos Natl Lab, Manuel Lujan Jr Neutron Scattering Ctr, POB 1663, Los Alamos, NM 87545 USA. RI Lujan Center, LANL/G-4896-2012 NR 15 TC 1 Z9 1 U1 0 U2 1 PU PLENUM PUBL CORP PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 0195-928X J9 INT J THERMOPHYS JI Int. J. Thermophys. PD MAR PY 1998 VL 19 IS 2 BP 461 EP 470 DI 10.1023/A:1022517511951 PG 10 WC Thermodynamics; Chemistry, Physical; Mechanics; Physics, Applied SC Thermodynamics; Chemistry; Mechanics; Physics GA ZY912 UT WOS:000074675100012 ER PT J AU Frazer, NB AF Frazer, NB TI Preserving natural laboratories SO ISSUES IN SCIENCE AND TECHNOLOGY LA English DT Editorial Material C1 Savannah River Ecol Lab, Aiken, SC 29802 USA. RP Frazer, NB (reprint author), Savannah River Ecol Lab, Aiken, SC 29802 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU NATL ACAD SCIENCES PI WASHINGTON PA 2101 CONSTITUTION AVE NW, WASHINGTON, DC 20418 USA SN 0748-5492 J9 ISSUES SCI TECHNOL JI Issues Sci. Technol. PD SPR PY 1998 VL 14 IS 3 BP 16 EP + PG 2 WC Engineering, Multidisciplinary; Engineering, Industrial; Multidisciplinary Sciences; Social Issues SC Engineering; Science & Technology - Other Topics; Social Issues GA ZH151 UT WOS:000073077900012 ER PT J AU Hoffman, AR AF Hoffman, AR TI No funds for ocean power SO ISSUES IN SCIENCE AND TECHNOLOGY LA English DT Editorial Material C1 US DOE, Off Util Technol Energy Efficiency & Renewable En, Washington, DC USA. RP Hoffman, AR (reprint author), US DOE, Off Util Technol Energy Efficiency & Renewable En, Washington, DC USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU NATL ACAD SCIENCES PI WASHINGTON PA 2101 CONSTITUTION AVE NW, WASHINGTON, DC 20418 USA SN 0748-5492 J9 ISSUES SCI TECHNOL JI Issues Sci. Technol. PD SPR PY 1998 VL 14 IS 3 BP 20 EP 20 PG 1 WC Engineering, Multidisciplinary; Engineering, Industrial; Multidisciplinary Sciences; Social Issues SC Engineering; Science & Technology - Other Topics; Social Issues GA ZH151 UT WOS:000073077900014 ER PT J AU Melgaard, DK Williamson, RL Beaman, JJ AF Melgaard, DK Williamson, RL Beaman, JJ TI Controlling remelting processes for superalloys and aerospace Ti alloys SO JOM-JOURNAL OF THE MINERALS METALS & MATERIALS SOCIETY LA English DT Article ID VACUUM AB Remelting is performed to facilitate the production of clean, fully dense, homogeneous castings of superalloys and aerospace titanium alloys and is crucial to the defect-free production of these important materials. Modern electroslag remelting and vacuum are remelting control systems are closed-loop, single input-single output systems that oversimplify the physical properties of the processes; the ever-increasing demand for cleaner, more highly engineered, chemically tuned alloys has pushed these control methodologies to their limit. A new generation of these controllers is being developed by the Specialty Metals Process Consortium and Sandia National Laboratories to answer the challenges of remelting control for the next generation of alloys; these control systems will use multiple sensor inputs and apply material-specific system and process models. C1 Sandia Natl Labs, Dept 1846, Albuquerque, NM 87185 USA. Univ Texas, Austin, TX USA. RP Melgaard, DK (reprint author), Sandia Natl Labs, Dept 1846, MS 1134,POB 5800, Albuquerque, NM 87185 USA. NR 37 TC 16 Z9 17 U1 0 U2 3 PU MINERALS METALS MATERIALS SOC PI WARRENDALE PA 420 COMMONWEALTH DR, WARRENDALE, PA 15086 USA SN 1047-4838 J9 JOM-J MIN MET MAT S JI JOM-J. Miner. Met. Mater. Soc. PD MAR PY 1998 VL 50 IS 3 BP 13 EP 17 DI 10.1007/s11837-998-0372-9 PG 5 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering; Mineralogy; Mining & Mineral Processing SC Materials Science; Metallurgy & Metallurgical Engineering; Mineralogy; Mining & Mineral Processing GA ZA966 UT WOS:000072420800004 ER PT J AU Bertram, LA Schunk, PR Kempka, SN Spadafora, F Minisandram, R AF Bertram, LA Schunk, PR Kempka, SN Spadafora, F Minisandram, R TI The macroscale simulation of remelting processes SO JOM-JOURNAL OF THE MINERALS METALS & MATERIALS SOCIETY LA English DT Article ID MOLTEN AB Vacuum are remelting and electroslag remelting processes are used to produce large (five tonne) insets of nickel-based superalloys, titanium alloys, and other high-value-added alloys. The remelting processes provide controlled solidification conditions capable of producing extremely uniform chemistry and microstructure; however, the con sequences of a single defect are potentially so great, that process improvements are being vigorously pursued by the Specialty Metals Processing Consortium. The ultimate modelling goal is the realistic description of the liquid-solid mixed-phase region of the ingot ("mushy zone"), so that solidification defects such as freckles, macrosegregation, and solidification white spots can be avoided. Reaching this goal requires a numerical strategy capable of yielding not only accurate temperatures at the macroscale, but also accurate temperature gradients. The numerical procedure also requires thermophysical-property data for the alloy and some furnace data (such as contact resistance at ingot-crucible interfaces) as well as characterization of the heat sources. C1 Sandia Natl Labs, Livermore, CA 94551 USA. RP Bertram, LA (reprint author), Sandia Natl Labs, MS9405,POB 969, Livermore, CA 94551 USA. NR 33 TC 21 Z9 23 U1 3 U2 12 PU MINERALS METALS MATERIALS SOC PI WARRENDALE PA 420 COMMONWEALTH DR, WARRENDALE, PA 15086 USA SN 1047-4838 J9 JOM-J MIN MET MAT S JI JOM-J. Miner. Met. Mater. Soc. PD MAR PY 1998 VL 50 IS 3 BP 18 EP 21 DI 10.1007/s11837-998-0373-8 PG 4 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering; Mineralogy; Mining & Mineral Processing SC Materials Science; Metallurgy & Metallurgical Engineering; Mineralogy; Mining & Mineral Processing GA ZA966 UT WOS:000072420800005 ER PT J AU Van Den Avyle, JA Brooks, JA Powell, AC AF Van Den Avyle, JA Brooks, JA Powell, AC TI Reducing defects in remelting processes for high-performance alloys SO JOM-JOURNAL OF THE MINERALS METALS & MATERIALS SOCIETY LA English DT Article AB Defect reduction is one of the most important goals in continuing research to improve remelting technologies, such as vacuum arc remelting, electroslag remelting, or hearth melting (plasma or electron beam), of specialty alloys. Ingot defects may originate from several sources in these processes, such as foreign materials in the melt stock or electrode, drop-in material from the furnace interior, and solidification defects. Laboratory- and industrial-scale melting experiments are used by Sandia National Laboratories and the Specialty Metals Processing Consortium to determine relationships between melt-processing conditions and defect formation. Examples described here include freckle formation, a solidification defect in large insets of alloy 625 (electroslag remelting), and alloy 718 (vacuum are remelting). These examples demonstrate how integrated melting experiments, process modelling, and inset analysis can guide the control of melting conditions to reduce defects. C1 Sandia Natl Labs, Albuquerque, NM 87175 USA. RP Van Den Avyle, JA (reprint author), Sandia Natl Labs, MS 1134, Albuquerque, NM 87175 USA. NR 13 TC 37 Z9 38 U1 1 U2 13 PU MINERALS METALS MATERIALS SOC PI WARRENDALE PA 420 COMMONWEALTH DR, WARRENDALE, PA 15086 USA SN 1047-4838 J9 JOM-J MIN MET MAT S JI JOM-J. Miner. Met. Mater. Soc. PD MAR PY 1998 VL 50 IS 3 BP 22 EP + PG 5 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering; Mineralogy; Mining & Mineral Processing SC Materials Science; Metallurgy & Metallurgical Engineering; Mineralogy; Mining & Mineral Processing GA ZA966 UT WOS:000072420800006 ER PT J AU Conry, MJ AF Conry, MJ TI The effect of seedbed condition on the grain yield and quality of spring malting barley SO JOURNAL OF AGRICULTURAL SCIENCE LA English DT Article ID SCREENINGS CONTENT; NITROGEN AB The effect of seedbed conditions at the time of sowing on the grain yield and quality ex-farm of spring-own malting barley was examined in three experiments in the south-east of Ireland in 1993-95. Blenheim malting barley sown in good seedbed conditions gave significantly (P < 0.05) greater yields (3.1-9.6 % more) than the identically treated crop, sown several days earlier, in less suitable seedbed conditions in all three experiments, but there was no effect on grain nitrogen content or the amount of screenings. The better soil conditions gave significantly (P < 0.05) better plant emergence, a greater number of fertile tillers and more grains per ear. C1 TEAGASC, Oak Pk Res Ctr, Carlow, Ireland. RP Conry, MJ (reprint author), TEAGASC, Oak Pk Res Ctr, Carlow, Ireland. NR 9 TC 3 Z9 3 U1 2 U2 3 PU CAMBRIDGE UNIV PRESS PI NEW YORK PA 40 WEST 20TH STREET, NEW YORK, NY 10011-4211 USA SN 0021-8596 J9 J AGR SCI JI J. Agric. Sci. PD MAR PY 1998 VL 130 BP 135 EP 138 DI 10.1017/S0021859697005005 PN 2 PG 4 WC Agriculture, Multidisciplinary SC Agriculture GA ZD995 UT WOS:000072746500002 ER PT J AU Minnich, MG Houk, RS AF Minnich, MG Houk, RS TI Comparison of cryogenic and membrane desolvation for attenuation of oxide, hydride and hydroxide ions and ions containing chlorine in inductively coupled plasma mass spectrometry SO JOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY LA English DT Article DE inductively coupled plasma mass spectrometry; cryogenic desolvation; membrane desolvation; vanadium; arsenic; actinides; oxide ions; metal hydride ions ID ATOMIC EMISSION-SPECTROMETRY; ULTRASONIC NEBULIZATION; OPERATING PARAMETERS; SAMPLE INTRODUCTION; ORGANIC-SOLVENTS; ANALYTE SIGNALS; TRACE-ELEMENTS; INTERFERENCES; INSTRUMENT; REDUCTION AB Conventional, cryogenic and membrane desolvation methods were compared with respect to sensitivity, MO+/M+ signal ratios and the aerosol gas flow rate required to maximize M+ and MO+ signals, Thorium was used to represent the actinides, which form relatively strong hydrides and hydroxides, The LaO+/La+ ratio is reduced from 0.24% with conventional desolvation to 0.08% with membrane desolvation and 0.01% with cryogenic desolvation, Membrane desolvation reduces ThH+ and ThOH+ 2-fold compared with conventional desolvation, Cryogenic desolvation attenuates ThH+ 7-fold and ThOH+ 20-fold compared with conventional desolvation, The three desolvation methods were also evaluated for the removal of CIO+ and ArCl+ for the determination of vanadium and arsenic at trace levels in the presence of chloride, The density of oxygen atoms is reduced as water vapor is removed, and chloride is also removed, presumably as hydrogen chloride, The concentration of vanadium in a urine standard reference material was determined by standard additions to be 7 ppb with cryogenic desolvation and 5 ppb with membrane desolvation, Analysis of several nasal wash samples using cryogenic and membrane desolvation yielded results that agreed within 5% for the two methods in all cases except for the sample with the highest V+ concentration. C1 Iowa State Univ Sci & Technol, Ames Lab, Dept Chem, US DOE, Ames, IA 50011 USA. RP Houk, RS (reprint author), Iowa State Univ Sci & Technol, Ames Lab, Dept Chem, US DOE, Ames, IA 50011 USA. NR 38 TC 50 Z9 54 U1 0 U2 5 PU ROYAL SOC CHEMISTRY PI CAMBRIDGE PA THOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON ROAD, CAMBRIDGE CB4 4WF, CAMBS, ENGLAND SN 0267-9477 J9 J ANAL ATOM SPECTROM JI J. Anal. At. Spectrom. PD MAR PY 1998 VL 13 IS 3 BP 167 EP 174 DI 10.1039/a704274d PG 8 WC Chemistry, Analytical; Spectroscopy SC Chemistry; Spectroscopy GA ZD166 UT WOS:000072658000002 ER PT J AU Katkov, II Mazur, P AF Katkov, II Mazur, P TI Influence of centrifugation regimes on motility, yield, and cell associations of mouse spermatozoa SO JOURNAL OF ANDROLOGY LA English DT Article; Proceedings Paper CT 25th Anniversary Meeting of Frozen Mice - Embryo and Gamete Gryopreservation CY SEP 24-28, 1997 CL BAR HARBOR, MAINE DE cryopreservation; mechanical sensitivity; damage; recovery; sedimentation; clusters ID SPERM; SEPARATION; CRYOPRESERVATION; VELOCITY; PLASMA AB Mouse sperm are exceptionally sensitive to mechanical forces associated with pipetting and mixing. This characteristic raised the question of the sensitivity of mouse sperm to centrifugation, a step necessary in the removal of cryoprotectants and a common component in the general manipulation of sperm suspensions for experimental purpose. Epididymal spermatozoa from ICR mice were isolated and manipulated to minimize pipetting and mixing damage. The centrifugal accelerations studied were 200, 400, 600, and 800 x g (measured with a stroboscope) for 5, 10, or 15 minutes of centrifugation time. The number of cells and the number of motile cells were counted. The percent motility and longevity, total yield, and motile yield were calculated. Centrifugation at 200 and 400 x g for short times (5 minutes) caused only a small loss in either immediate or 2.5-hour motility, but centrifugation at 600 and 800 x g for 15 minutes produced up to a fivefold loss. Low speed/short time centrifugation pelleted only about half of the cells; the others were lost when the supernatant was removed. The maximum number of motile sperm (motile yield) was obtained at intermediate centrifugal forces (similar to 400 x g for 10-12 minutes), and it is the total number of motile sperm (and not the percent motility) that is important in the use of cryopreserved sperm to regenerate cryopreserved mutant lines. Relative centrifugal force and centrifugation time exhibit reciprocity (e.g., 200 x g for 10 minutes produces similar results to 400 x g for 5 minutes). The spermatozoa must be centrifuged under carefully defined conditions to minimize the damage and to maximize the recovery of viable cells. C1 Oak Ridge Natl Lab, Fundamental & Appl Cryobiol Grp, Div Life Sci, Oak Ridge, TN 37831 USA. Oak Ridge Associated Univ, Oak Ridge, TN USA. RP Katkov, II (reprint author), Oak Ridge Natl Lab, Fundamental & Appl Cryobiol Grp, Div Life Sci, POB 2009,MS 8080, Oak Ridge, TN 37831 USA. RI Katkov, Igor/D-7163-2015 OI Katkov, Igor/0000-0001-9251-0494 FU NICHD NIH HHS [R01-HD30274] NR 35 TC 46 Z9 47 U1 0 U2 2 PU AMER SOC ANDROLOGY, INC PI LAWRENCE PA C/O ALLEN PRESS, INC PO BOX 368, LAWRENCE, KS 66044 USA SN 0196-3635 J9 J ANDROL JI J. Androl. PD MAR-APR PY 1998 VL 19 IS 2 BP 232 EP 241 PG 10 WC Andrology SC Endocrinology & Metabolism GA ZH107 UT WOS:000073072900014 PM 9570748 ER PT J AU Togami, TC Brown, FA Forrestal, MJ Baker, WE AF Togami, TC Brown, FA Forrestal, MJ Baker, WE TI Performance evaluation of acclerometers to 200,000 G SO JOURNAL OF APPLIED MECHANICS-TRANSACTIONS OF THE ASME LA English DT Article C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. Univ New Mexico, Dept Mech Engn, Albuquerque, NM 87171 USA. RP Togami, TC (reprint author), Sandia Natl Labs, Albuquerque, NM 87185 USA. NR 3 TC 4 Z9 11 U1 0 U2 1 PU ASME-AMER SOC MECHANICAL ENG PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 0021-8936 J9 J APPL MECH-T ASME JI J. Appl. Mech.-Trans. ASME PD MAR PY 1998 VL 65 IS 1 BP 266 EP 268 DI 10.1115/1.2789036 PG 3 WC Mechanics SC Mechanics GA ZG771 UT WOS:000073037700037 ER PT J AU Turkot, BA Robertson, IM Rehn, LE Baldo, PM Forbes, DV Coleman, JJ AF Turkot, BA Robertson, IM Rehn, LE Baldo, PM Forbes, DV Coleman, JJ TI On the amorphization process in Al0.6Ga0.4As/GaAs heterostructures SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID CHEMICAL VAPOR-DEPOSITION; ION-IMPLANTATION DAMAGE; GAAS; DEPENDENCE; ALXGA1-XAS; ALAS AB The amorphization mechanism operative in Al0.6Ga0.4As/GaAs structures has been studied by using ion implantation at 77 K with different ion masses (Kr and Ar) and energies (1-3 MeV). The damage produced by these implantations was examined by using a combination of ion channeling and cross-sectional transmission electron microscopy. For all implantation conditions, the damage accumulation produced by implantation at 77 K increases with depth into the Al0.6Ga0.4As layer. Neither point defects nor energetically dense cascade events by themselves were found to be sufficient to drive Al0.6Ga0.4As amorphous at 77 K. Amorphization occurred only when a high density of energetically dense cascade events were superimposed on a high total defect population. These conditions were satisfied deep in the layer and only for the 1.5 MeV Kr ion implantation. With the exception pf the amorphous material, the damage structure produced at 77 K recovered on warming to room temperature. The recovered structure consisted of dislocation loops or planar defects. (C) 1998 American Institute of Physics. C1 Univ Illinois, Dept Mat Sci & Engn, Urbana, IL 61801 USA. Argonne Natl Lab, Argonne, IL 60439 USA. Univ Illinois, Dept Elect & Comp Engn, Urbana, IL 61801 USA. RP Turkot, BA (reprint author), Univ Illinois, Dept Mat Sci & Engn, Urbana, IL 61801 USA. RI Coleman, James/C-9703-2011 NR 21 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 MAR 1 PY 1998 VL 83 IS 5 BP 2539 EP 2547 DI 10.1063/1.366630 PG 9 WC Physics, Applied SC Physics GA YZ942 UT WOS:000072310700024 ER PT J AU Pryor, C Kim, J Wang, LW Williamson, AJ Zunger, A AF Pryor, C Kim, J Wang, LW Williamson, AJ Zunger, A TI Comparison of two methods for describing the strain profiles in quantum dots SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID OPTICAL-PROPERTIES; ELECTRONIC-STRUCTURE; SILICON; ALLOYS AB The electronic structure of interfaces between lattice-mismatched semiconductors is sensitive to the strain. We compare two approaches for calculating such inhomogeneous strain-continuum elasticity [(CE), treated as a finite difference problem] and atomistic elasticity. While for small strain the two methods must agree, for the large strains that exist between lattice-mismatched III-V semiconductors (e.g., 7% for InAs/GaAs outside the linearity regime of CE) there are discrepancies. We compare the strain profile obtained by both approaches (including the approximation of the correct C-2 symmetry by the C-4 symmetry in the CE method) when applied to C-2-symmetric InAs pyramidal dots capped by GaAs. (C) 1998 American Institute of Physics. C1 Univ Lund, Dept Solid State Phys, S-22100 Lund, Sweden. Natl Renewable Energy Lab, Golden, CO 80401 USA. RP Pryor, C (reprint author), Univ Lund, Dept Solid State Phys, Box 118, S-22100 Lund, Sweden. RI Zunger, Alex/A-6733-2013 NR 17 TC 324 Z9 327 U1 4 U2 18 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 MAR 1 PY 1998 VL 83 IS 5 BP 2548 EP 2554 DI 10.1063/1.366631 PG 7 WC Physics, Applied SC Physics GA YZ942 UT WOS:000072310700025 ER PT J AU Streiffer, SK Parker, CB Romanov, AE Lefevre, MJ Zhao, L Speck, JS Pompe, W Foster, CM Bai, GR AF Streiffer, SK Parker, CB Romanov, AE Lefevre, MJ Zhao, L Speck, JS Pompe, W Foster, CM Bai, GR TI Domain patterns in epitaxial rhombohedral ferroelectric films. I. Geometry and experiments SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID MISFIT RELAXATION MECHANISMS; PBTIO3 THIN-FILMS; FERROELASTIC FILMS; CONFIGURATIONS; MICROSTRUCTURE; MOCVD; MGO AB Possible domain patterns are developed for (001) oriented (pseudocubic indexing) epitaxial rhombohedral perovskite ferroelectric (F-R) films. We assume that the films are grown above their Curie temperature (T-C) in a cubic paraelectric (P-C) state, The rhombohedral distortion consists of a "stretch" along one of the four [111] crystallographic directions of the cubic perovskite unit cell. Domain pattern formation is concurrent with the P-C-->F-R transformation on cooling from the growth temperature. The domain patterns form to minimize elastic energy in the film, at the energetic expense of both forming domain boundaries and developing local stresses in the substrate. Eight possible domains may form, half of which are related by inversion, thus leading to four mechanically distinct variants. The possible domain walls are determined by mechanical and charge compatibility and follow closely from the analysis of Fousek and Janovec [J. Appl. Phys. 40, 135 (1969)]. Domain patterns may develop with either {100} or {101} boundaries. In both cases, the individual domains in the patterns are energetically degenerate and thus equal width lamellar patterns are predicted. When polarization is included in the analysis, the {100} boundary patterns have no normal component of the net polarization, whereas the {101} boundary patterns correspond to the fully poled state. We report on experimental observation of {100} domain patterns in epitaxial PbZr0.80Ti0.20O3 and PbZr0.65Ti0.35O3 films. (C) 1998 American Institute of Physics. C1 N Carolina State Univ, Dept Mat Sci & Engn, Raleigh, NC 27695 USA. Max Planck Inst Met Forsch, D-70174 Stuttgart, Germany. Univ Calif Santa Barbara, Dept Mat, Santa Barbara, CA 93106 USA. Tech Univ Dresden, D-01069 Dresden, Germany. Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. Russian Acad Sci, AF Ioffe Physicotech Inst, St Petersburg 194021, Russia. RP Streiffer, SK (reprint author), N Carolina State Univ, Dept Mat Sci & Engn, Box 7907, Raleigh, NC 27695 USA. EM speck@mrl.ucsb.edu RI Streiffer, Stephen/A-1756-2009; Speck, James/H-5646-2011 NR 26 TC 203 Z9 204 U1 13 U2 83 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 MAR 1 PY 1998 VL 83 IS 5 BP 2742 EP 2753 DI 10.1063/1.366632 PG 12 WC Physics, Applied SC Physics GA YZ942 UT WOS:000072310700052 ER PT J AU Romanov, AE Lefevre, MJ Speck, JS Pompe, W Streiffer, SK Foster, CM AF Romanov, AE Lefevre, MJ Speck, JS Pompe, W Streiffer, SK Foster, CM TI Domain pattern formation in epitaxial rhombohedral ferroelectric films. II. Interfacial defects and energetics SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID MISFIT RELAXATION MECHANISMS; THIN-FILMS; FERROELASTIC FILMS; CONFIGURATIONS AB The coherency defect technique is developed for the domain pattern energetics in rhombohedral (001) epitaxial ferroelectric films. The coherency defects that are necessary to maintain the epitaxy during the ferroelectric phase transition are considered to be the only sources of elastic strains and stresses (and, correspondingly energy) in the film/substrate system. The coherency defects include: (i) a uniform distribution of edge dislocations which are responsible for the in-plane tension or compression and have Burgers vectors parallel to the interface; and two kinds of mesoscale defects: (ii) Somigliana screw dislocations which are responsible for in-plane shear; and (iii) wedge disclinations which are responsible for the out of plane rotations in neighboring domains. Using this approach, analytical expressions were found for the elastic energy in the film/substrate system for both the {101}-r(i)/r(j) and the {100}-r(i)/r(j) domain patterns. These two configurations differ by the orientation of domain walls, coherency defect content, and also the morphology of the free surface (flat versus puckered surfaces). Calculations are performed for screened mesoscale coherency defect configurations that represent a single embedded domain pattern and multidomain patterns, The following mesoscale defect configurations are used for these calculations: Somigliana dislocation dipoles, wedge disclination dipoles, Somigliana dislocation quadrupoles, and disclination quadrupoles. It is predicted that there is no critical thickness for domain pattern formation in rhombohedral ferroelectric epitaxial films. Agreement is shown between experimentally observed domain widths and theoretically predicted values. (C) 1998 American Institute of Physics. C1 Max Planck Inst Met Forsch, D-70174 Stuttgart, Germany. Univ Calif Santa Barbara, Dept Mat, Santa Barbara, CA 93106 USA. Tech Univ Dresden, D-01069 Dresden, Germany. N Carolina State Univ, Dept Mat Sci & Engn, Raleigh, NC 27695 USA. Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. Russian Acad Sci, AF Ioffe Physicotech Inst, St Petersburg 194021, Russia. RP Romanov, AE (reprint author), Max Planck Inst Met Forsch, D-70174 Stuttgart, Germany. EM speck@mrl.ucsb.edu RI Streiffer, Stephen/A-1756-2009; Speck, James/H-5646-2011 NR 19 TC 86 Z9 87 U1 4 U2 42 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 MAR 1 PY 1998 VL 83 IS 5 BP 2754 EP 2765 DI 10.1063/1.366636 PG 12 WC Physics, Applied SC Physics GA YZ942 UT WOS:000072310700053 ER PT J AU Warren, WL Seager, CH Soininen, E Benalloul, P Barthou, C Sun, SS AF Warren, WL Seager, CH Soininen, E Benalloul, P Barthou, C Sun, SS TI Chromaticity and electroluminescent efficiency of atomic layer epitaxy SrS : Ce thin films SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID ELECTRON-PARAMAGNETIC-RESONANCE; SRSCE3+ AB We have studied various factors that control the luminous properties of atomic layer epitaxy (ALE) SrS:Ce electroluminescent (EL) devices by using electron paramagnetic resonance, photoluminescent decay, x-ray diffraction, and charge-voltage characterization. EL and PL light is green shifted in ALE SrS:Ce films, compared to powders and thin films prepared with some other techniques. The origin of the green shift is discussed. Moderate heat treatments of as-deposited SrS:Ce devices were found to dramatically improve the EL efficiency. This is due to the removal of defects leading to nonradiative Ce3+ decay and to reduction of Ce4+ to radiative Ce3+. Different heat treatments were found to influence the transferred charge, so that there is an optimal heat treatment temperature between 500 and 750 degrees C. Heat treatments also induce macroscopic stress in these SrS:Ce films. This was seen to induce a local stress around Ce3+ sites. However, the stresses were not found to directly correlate with the luminous efficiency, The SrS:Ge growth temperature was found to affect the Ce3+ excitation efficiency in EL. Electronic traps in SrS:Ce films are discussed. We suggest that some traps can be beneficial in providing necessary charge for the Ce3+ excitation process and others can be deleterious in that they suppress radiative Ce3+ decay events. To determine the effects of Ce doping, undoped SrS films were also deposited and fully characterized. Finally, we compare the properties of films prepared by ALE to those deposited via rf sputtering. (C) 1998 American Institute of Physics. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. Planar Int Ltd, SF-02201 Espoo, Finland. Univ Paris 06, Lab Opt Solides, F-75252 Paris, France. Planar Amer Inc, Beaverton, OR 97006 USA. RP Warren, WL (reprint author), DSO, DARPA, 3701 N Fairfax Dr, Arlington, VA 22203 USA. EM wwarren@darpa.mil NR 27 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 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD MAR 1 PY 1998 VL 83 IS 5 BP 2788 EP 2795 DI 10.1063/1.366637 PG 8 WC Physics, Applied SC Physics GA YZ942 UT WOS:000072310700056 ER PT J AU Ho, PC Palmer, DA AF Ho, PC Palmer, DA TI Determination of ion association in dilute aqueous lithium chloride and lithium hydroxide solutions to 600 degrees C and 300 MPa by electrical conductance measurements SO JOURNAL OF CHEMICAL AND ENGINEERING DATA LA English DT Article ID WATER; CONDUCTIVITY; TEMPERATURES AB The limiting molar conductances (Lambda(0)) and ion association constants of dilute aqueous lithium chloride and lithium hydroxide solutions (<0.01 mol.kg(-1)) were determined by electrical conductance measurements at temperatures from 100 to 600 degrees C and pressures up to 300 MPa. The values of Lambda(0)(LiCl) and Lambda(0)(LiOH) obtained from with Shedlovsky (at densities greater than or equal to 0.6 g.cm(-3)) and Fuoss-Hsia-Fernandez-Prini (FHFP) equations (at densities <0.6 g.cm(-8)) increase with increasing temperature up to 300 degrees C and decreasing density. Above 300 degrees C and densities between 0.8 and 0.5 g.cm(-3) for LiCl(aq) and 0.8 to 0.6 g.cm(-3) for LiOH(aq), Lambda(0) is nearly temperature-independent but does increase linearly with decreasing density. The molal association constants, K-A(m) for both electrolytes were computed exclusively from the data greater than or equal to 400 degrees C (at densities 0.8-0.3 for LiCl and 0.8-0.5 g.cm(-3) for LiOH) by the Shedlovsky equation and can be represented as functions of temperature (Kelvin) and the logarithm of water density (rho(w)) as follows: log K-A(m)(LiCl) = 0.724 - 8.980/(T/X) - (12.796 - 5431.2/(T/K)) log rho(w)/g.cm(-3)) and log K-A(m)(LiOH) = 0.856 + 135.60/(T/K) - (11.998 - 4226.3/(T/K)) log rho(w)/(g.cm(-3)). At corresponding conditions and within experimental error, the degree of ion association of LiCl(aq) is comparable with NaCl(aq) and KCl(aq), whereas ion association for LiOH(aq), is significantly stronger than for NaOH(aq) and KOH(aq). Moreover, the same values of K-A(m) were obtained for each electrolyte irrespective of the whether the Shedlovsky or FHFP equations were employed. This point is exemplified by a comparison of the K-A(m) value for LiCl obtained from the present study with those of a recent investigation that utilized an advanced design for moderately high temperature conductance measurements. C1 Oak Ridge Natl Lab, Div Chem & Analyt Sci, Oak Ridge, TN 37831 USA. RP Ho, PC (reprint author), Oak Ridge Natl Lab, Div Chem & Analyt Sci, POB 2008, Oak Ridge, TN 37831 USA. NR 28 TC 25 Z9 26 U1 4 U2 12 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0021-9568 J9 J CHEM ENG DATA JI J. Chem. Eng. Data PD MAR-APR PY 1998 VL 43 IS 2 BP 162 EP 170 DI 10.1021/je970198b PG 9 WC Thermodynamics; Chemistry, Multidisciplinary; Engineering, Chemical SC Thermodynamics; Chemistry; Engineering GA ZD783 UT WOS:000072723400009 ER PT J AU Viel, A Leforestier, C Miller, WH AF Viel, A Leforestier, C Miller, WH TI Quantum mechanical calculation of the rate constant for the reaction H+O-2 -> OH+O SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID DISCRETE VARIABLE REPRESENTATION; POTENTIAL-ENERGY SURFACES; CUMULATIVE REACTION PROBABILITY; MINIMAL RESIDUAL ALGORITHM; H+O-2 SCATTERING; UNIMOLECULAR DISSOCIATION; RECOMBINATION RESONANCES; TRAJECTORY CALCULATIONS; CONICAL INTERSECTION; COMBUSTION REACTION AB Quantum rate calculations for the H+O-2-->HO+O combustion reaction, as well as for the reverse reaction, are reported. Using the DMBE IV potential energy surface, the cumulative reaction probability N-0(E) has been directly computed for total angular momentum J=0, by means of the Seideman, Manthe and Miller Lanczos-based absorbing boundary condition method [J. Chem. Phys. 96, 4412 (1992); 99, 3411 (1993)]. Special attention has been paid to the definition of the molecular basis set, and to the sensitivity of the results to the absorbing potentials used in the asymptotic regions. The N-0(E) results show very good overall agreement with the coupled channel calculations of Pack et al. [J. Chem. Phys. 102, 5998 (1995)], although the highly oscillatory behavior just above threshold renders such a comparison difficult in that energy range. The behavior of the J not equal 0 cumulative reaction probability has been estimated from calculations using the J(z)-conserving approximation for J values in the range 10-70. This allowed us to define which reference geometry should be used in the J-shifting approximation, in order to compute the cumulative reaction probability N-J(E) for any J value. By imposing conservation of the total energy within this approximation, the rate constants are shown to display better agreement with the experimental results. (C) 1998 American Institute of Physics. [S0021-9606(98)02609-9]. C1 Univ Montpellier 2, Lab Struct & Dynam Syst Mol & Solides, UMR 5636, F-34095 Montpellier 05, France. Univ Calif Berkeley, Lawrence Berkeley Lab, Dept Chem, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Chem Sci, Berkeley, CA 94720 USA. RP Viel, A (reprint author), Univ Montpellier 2, Lab Struct & Dynam Syst Mol & Solides, UMR 5636, CC 014, F-34095 Montpellier 05, France. RI VIEL, Alexandra/A-7894-2008 NR 52 TC 42 Z9 42 U1 2 U2 6 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 MAR 1 PY 1998 VL 108 IS 9 BP 3489 EP 3497 DI 10.1063/1.475776 PG 9 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA YZ048 UT WOS:000072215000014 ER PT J AU Parks, EK Nieman, GC Kerns, KP Riley, SJ AF Parks, EK Nieman, GC Kerns, KP Riley, SJ TI The thermodynamics of nitrogen adsorption on nickel clusters: Ni-19-Ni-71 SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID MOLECULAR NITROGEN; CHEMISORBED MOLECULES; IONIZATION-POTENTIALS; LATERAL INTERACTIONS; COBALT CLUSTERS; CHEMICAL PROBES; METAL-SURFACES; NI(110); N-2; N2 AB Equilibrium constants for the chemisorption reactions of molecular nitrogen with nickel clusters Ni-n have been determined as a function of temperature for n = 19 to 71. Van't Hoff analysis of the data yields standard-state changes in reaction enthalpy and entropy. These changes are related to what is known about nickel cluster structure and the nature of the cluster-N-2 interaction. In general, the adsorption energy is highest for the smallest clusters studied, reaching values twice those for N-2 adsorption on bulk nickel surfaces. In many cases, there is a correlation between enthalpy and entropy: high adsorption energy is accompanied by a large change in entropy, and vice versa. These effects are discussed in terms of the configurational entropy of reaction and the frequencies of the frustrated translational and rotational motions of the adsorbed N-2 molecules. (C) 1998 American Institute of Physics. C1 Argonne Natl Lab, Div Chem, Argonne, IL 60439 USA. Monmouth Coll, Dept Chem, Monmouth, IL 61462 USA. RP Parks, EK (reprint author), Argonne Natl Lab, Div Chem, 9700 S Cass Ave, Argonne, IL 60439 USA. NR 59 TC 34 Z9 34 U1 2 U2 9 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD MAR 1 PY 1998 VL 108 IS 9 BP 3731 EP 3739 DI 10.1063/1.475779 PG 9 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA YZ048 UT WOS:000072215000041 ER PT J AU Martin, JE Anderson, RA Tigges, CP AF Martin, JE Anderson, RA Tigges, CP TI Simulation of the athermal coarsening of composites structured by a uniaxial field SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID ELECTRORHEOLOGICAL FLUIDS; DYNAMIC SIMULATION; SPHERES; CONDUCTIVITY; LATTICES; ARRAY AB We report the results of a computer simulation of the evolution of structure in a two component fluid consisting of a liquid phase and a dispersed colloidal phase subjected to a uniaxial field. Our primary objective is to understand the mechanism and kinetics of coarsening and the emergence of crystallinity, Using an efficient, linear-N simulation method we report studies of systems of N = 10 000 particles over the concentration range of 10-50 vol %. We present a variety of methods. of characterizing the structures that emerge, including the anisotropy of the conductivity, capacitance and dipolar interaction energy, the two-dimensional pair correlation function, principal moments of the gyration tensor, velocity correlation functions, microcrystallinity and coordination number, and the optical attenuation length. We conclude that athermal coarsening is effectively driven by the presence of defect structures and that as the concentration increases, the structures progressively lose the well-known "chain" anisotropy evinced at low concentration. (C) 1998 American Institute of Physics. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Martin, JE (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. NR 27 TC 73 Z9 74 U1 1 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 MAR 1 PY 1998 VL 108 IS 9 BP 3765 EP 3787 DI 10.1063/1.475781 PG 23 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA YZ048 UT WOS:000072215000044 ER PT J AU Holmes, HF Mesmer, RE AF Holmes, HF Mesmer, RE TI Isopiestic molalities for aqueous solutions of the alkali metal hydroxides at elevated temperatures SO JOURNAL OF CHEMICAL THERMODYNAMICS LA English DT Article DE MOH(aq); isopiestic; high temperature; osmotic; activity ID THERMODYNAMIC PROPERTIES; ELECTROLYTES; NAOH(AQ); SULFATES; WATER AB Isopiestic molalities of aqueous solutions of the alkali metal hydroxides have been measured at T = (383.25, 413.12, and 443409) K. The isopiestic standard for calculation of osmotic coefficients was NaCl(aq). The ion-interaction model gave an excellent fit with the experimental osmotic coefficients and provided parameters for the calculation of activity coefficients. Osmotic and activity coefficients both decrease with increasing temperature in this temperature range. As at T = 298.15 K, the order of the results is the reverse of that for the alkali metal chlorides. The model of Simonson et al. (J. Chem. Thermodynamics 1989, 21, 561-584) is an excellent predictor of the experimental results for NaOH(aq). A simple model is presented from which activity and osmotic coefficients (at p(sat)) can be calculated as a function of molality for T = 273.15 K to T = 523.15 K. C1 Oak Ridge Natl Lab, Div Chem & Analyt Sci, Oak Ridge, TN 37831 USA. RP Mesmer, RE (reprint author), Oak Ridge Natl Lab, Div Chem & Analyt Sci, POB 2008, Oak Ridge, TN 37831 USA. EM rem@ornl.gov NR 37 TC 24 Z9 24 U1 2 U2 8 PU ACADEMIC PRESS LTD PI LONDON PA 24-28 OVAL RD, LONDON NW1 7DX, ENGLAND SN 0021-9614 J9 J CHEM THERMODYN JI J. Chem. Thermodyn. PD MAR PY 1998 VL 30 IS 3 BP 311 EP 326 DI 10.1006/jcht.1997.0301 PG 16 WC Thermodynamics; Chemistry, Physical SC Thermodynamics; Chemistry GA ZG866 UT WOS:000073047900004 ER PT J AU Albright, JG Rizzo, P Rard, JA AF Albright, JG Rizzo, P Rard, JA TI Isopiestic determination of the osmotic and activity coefficients of Cu(NO3)(2)(aq) at the temperature 298.15 K SO JOURNAL OF CHEMICAL THERMODYNAMICS LA English DT Article DE isopiestic measurements; copper nitrate; osmotic coefficients; activity coefficients; Pitzer's equation ID MUTUAL DIFFUSION-COEFFICIENTS; EARTH ELECTROLYTE-SOLUTIONS; THERMODYNAMIC PROPERTIES; AQUEOUS NICL2; 25-DEGREES-C; SOLUBILITY; SYSTEM; DENSITIES; EU(NO3)3; NITRATES AB The four previous isopiestic investigations of Cu(NO3)(2)(aq) at the temperature 298.15 K exhibit a remarkable lack of agreement. Consequently, isopiestic vapor-pressure measurements were performed for Cu(NO3)(2)(aq) solutions at T = 298.15 K both at the Texas Christian University and the Lawrence Livermore National Laboratory. These measurements extend from molality m = (0.0638 to 6.9235) mol.kg(-1). Under the conditions typically used for isopiestic experiments, it is found that solutions of Cu(NO3)(2)(aq) at higher molalities lose HNO3 into the vapor phase, resulting in a gradual increase in the extent of hydrolysis of their solutions as the samples are re-equilibrated. This produces a progressive downward drift in the apparent osmotic coefficients. Consequently, most previous higher-molality isopiestic results for this system are believed to be unreliable. Experiments were performed to quantify and to minimize the effect of this hydrolysis on the resulting osmotic coefficients. These experiments indicate that the error in the osmotic coefficient from this HNO3 loss is insignificant at lower molalities of Cu(NO3)(2)(aq); at m = 4 mol.kg(-1) it is less than or equal to 0.2 per cent, but above m approximate to 5 mol.kg(-1) it can become quite significant. Recommended values of the osmotic coefficients, water activities, and mean activity coefficients of Cu(NO3)(2)(aq) are presented up to m = 3.00 mol.kg(-1), the maximum molality where we consider them to be completely accurate, and, with slightly lower accuracy, up to m = 6.9235 mol.kg(-1). Pitzer's equation was found to represent reliably the experimental osmotic coefficients provided the third virial coefficient was ionic-strength dependent. C1 Texas Christian Univ, Dept Chem, Ft Worth, TX 76129 USA. Univ Calif Lawrence Livermore Natl Lab, Earth & Environm Sci Directorate, Livermore, CA 94550 USA. RP Rard, JA (reprint author), Texas Christian Univ, Dept Chem, Ft Worth, TX 76129 USA. EM rard1@llnl.gov RI rizzo, paola/I-3016-2012 NR 33 TC 12 Z9 13 U1 0 U2 5 PU ACADEMIC PRESS LTD PI LONDON PA 24-28 OVAL RD, LONDON NW1 7DX, ENGLAND SN 0021-9614 J9 J CHEM THERMODYN JI J. Chem. Thermodyn. PD MAR PY 1998 VL 30 IS 3 BP 327 EP 352 DI 10.1006/jcht.1997.0307 PG 26 WC Thermodynamics; Chemistry, Physical SC Thermodynamics; Chemistry GA ZG866 UT WOS:000073047900005 ER PT J AU Richards, WG Sweeney, WE Yoder, BK Wilkinson, JE Woychik, RP Avner, ED AF Richards, WG Sweeney, WE Yoder, BK Wilkinson, JE Woychik, RP Avner, ED TI Epidermal growth factor receptor activity mediates renal cyst formation in polycystic kidney disease SO JOURNAL OF CLINICAL INVESTIGATION LA English DT Article DE epidermal growth factor receptor; tyrosine kinase activity; polycystic kidney disease; mouse mutations ID METANEPHRIC ORGAN-CULTURE; EGF RECEPTOR; CELL-PROLIFERATION; TYROSINE KINASE; MOUSE KIDNEY; MICE; EXPRESSION; GENE; PHENOTYPE; MUTATION AB A consistent phenotype observed in both human patients and several different mouse models of autosomal recessive polycystic kidney disease (ARPKD) is an increased activity of the epidermal growth factor receptor (EGFR) in the affected kidneys. To determine whether this increased activity of the EGFR is a functional event that is directly part of the disease pathway of renal cyst formation, we used a genetic approach to introduce a mutant EGFR with decreased tyrosine kinase activity into a murine model of ARPKD, We found that the modified form of the EGFR could block the increase in EGFR-specific tyrosine kinase activity that normally accompanies the development of renal cysts, and this correlated with an improvement in kidney function and a substantial decrease in cyst formation in the collecting ducts, These results suggest that changes in the expression of the EGFR contribute to the formation of cysts in the collecting ducts, and that drugs that target the tyrosine kinase activity of the EGFR may potentially be therapeutic in ARPKD. C1 Case Western Reserve Univ, Rainbow Babies & Childrens Hosp, Dept Pediat, Cleveland, OH 44106 USA. Oak Ridge Natl Lab, Div Life Sci, Oak Ridge, TN 37831 USA. Univ Tennessee, Coll Vet Med, Dept Pathobiol, Knoxville, TN 37996 USA. RP Avner, ED (reprint author), Case Western Reserve Univ, Rainbow Babies & Childrens Hosp, Dept Pediat, 11100 Euclid Ave, Cleveland, OH 44106 USA. FU NIDDK NIH HHS [R01DK5106801] NR 31 TC 139 Z9 145 U1 1 U2 2 PU ROCKEFELLER UNIV PRESS PI NEW YORK PA 1114 FIRST AVE, 4TH FL, NEW YORK, NY 10021 USA SN 0021-9738 J9 J CLIN INVEST JI J. Clin. Invest. PD MAR 1 PY 1998 VL 101 IS 5 BP 935 EP 939 DI 10.1172/JCI2071 PG 5 WC Medicine, Research & Experimental SC Research & Experimental Medicine GA ZB194 UT WOS:000072445800003 PM 9486961 ER PT J AU Hellyer, TJ DesJardin, LE Beggs, ML Yang, Z Eisenach, KD Cave, MD Bates, JH Assaf, MK Crawford, JT AF Hellyer, TJ DesJardin, LE Beggs, ML Yang, Z Eisenach, KD Cave, MD Bates, JH Assaf, MK Crawford, JT TI IS6110 homologs are present in multiple copies in mycobacteria other than tuberculosis-causing mycobacteria SO JOURNAL OF CLINICAL MICROBIOLOGY LA English DT Letter ID DNA C1 Univ Arkansas Med Sci, John L McClellan Mem Vet Hosp, Med Res Serv, Dept Pathol, Little Rock, AR 72205 USA. Univ Arkansas Med Sci, John L McClellan Mem Vet Hosp, Med Res Serv, Dept Anat, Little Rock, AR 72205 USA. Univ Arkansas Med Sci, John L McClellan Mem Vet Hosp, Med Res Serv, Dept Med, Little Rock, AR 72205 USA. Univ Calif Lawrence Livermore Natl Lab, Biol & Biotechnol Res Program, Livermore, CA USA. Ctr Dis Control & Prevent, TB Mycobacteriol Branch, Atlanta, GA USA. RP Hellyer, TJ (reprint author), Univ Arkansas Med Sci, John L McClellan Mem Vet Hosp, Med Res Serv, Dept Pathol, Little Rock, AR 72205 USA. NR 8 TC 2 Z9 2 U1 0 U2 1 PU AMER SOC MICROBIOLOGY PI WASHINGTON PA 1325 MASSACHUSETTS AVENUE, NW, WASHINGTON, DC 20005-4171 USA SN 0095-1137 J9 J CLIN MICROBIOL JI J. Clin. Microbiol. PD MAR PY 1998 VL 36 IS 3 BP 853 EP 854 PG 2 WC Microbiology SC Microbiology GA YX389 UT WOS:000072035100055 PM 9508334 ER PT J AU Mian, IS Moser, MJ Holley, WR Chatterjee, A AF Mian, IS Moser, MJ Holley, WR Chatterjee, A TI Statistical modelling and phylogenetic analysis of a deaminase domain SO JOURNAL OF COMPUTATIONAL BIOLOGY LA English DT Article DE hidden Markov model; RNA editing; deamination; TENR protein; DM domain ID HIDDEN MARKOV-MODELS; RNA ADENOSINE-DEAMINASE; PROTEIN-SEQUENCE HOMOLOGY; BLASTICIDIN-S-DEAMINASE; HEPATITIS-DELTA VIRUS; AMINO-ACID-SEQUENCE; PRE-MESSENGER-RNAS; CYTIDINE DEAMINASE; BACILLUS-SUBTILIS; DEOXYCYTIDYLATE DEAMINASE AB Deamination reactions are catalyzed by a variety of enzymes including those involved in nucleoside/nucleotide metabolism and cytosine to uracil (C-->U) and adenosine to inosine (A-->I) mRNA editing, The active site of the deaminase (DM) domain in these enzymes contains a conserved histidine (or rarely cysteine), two cysteines and a glutamate proposed to act as a proton shuttle during deamination. Here, a statistical model, a hidden Markov model (HMM), of the DM domain has been created which identifies currently known DM domains and suggests new DM domains in viral, bacterial and eucaryotic proteins, However, no DM domains were identified in the currently predicted proteins from the archaeon Methanococcus jannaschii and possible causes for, and a potential means to ameliorate this situation are discussed, In some of the newly identified DM domains, the glutamate is changed to a residue that could not function as a proton shuttle and in one instance (Mus musculus spermatid protein TENR) the cysteines are also changed to lysine and serine, These may be non-competent DM domains able to bind but not act upon their substrate, Phylogenetic analysis using an HMM-generated alignment of DM domains reveals three branches with clear substructure in each branch, The results suggest DM domains that are candidates for yeast, platyhelminth, plant and mammalian C-->U and A-->I mRNA editing enzymes, Some bacterial and eucaryotic DM domains form distinct branches in the phylogenetic tree suggesting the existence of common, novel substrates. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Div Life Sci, Berkeley, CA 94720 USA. RP Univ Calif Berkeley, Lawrence Berkeley Lab, Div Life Sci, Mail Stop 29-100,1 Cyclotron Rd, Berkeley, CA 94720 USA. EM SMian@lbl.gov NR 75 TC 19 Z9 20 U1 0 U2 0 PU MARY ANN LIEBERT, INC PI NEW ROCHELLE PA 140 HUGUENOT STREET, 3RD FL, NEW ROCHELLE, NY 10801 USA SN 1066-5277 EI 1557-8666 J9 J COMPUT BIOL JI J. Comput. Biol. PD SPR PY 1998 VL 5 IS 1 BP 57 EP 72 DI 10.1089/cmb.1998.5.57 PG 16 WC Biochemical Research Methods; Biotechnology & Applied Microbiology; Computer Science, Interdisciplinary Applications; Mathematical & Computational Biology; Statistics & Probability SC Biochemistry & Molecular Biology; Biotechnology & Applied Microbiology; Computer Science; Mathematical & Computational Biology; Mathematics GA ZD374 UT WOS:000072678800005 PM 9541871 ER PT J AU Smolarkiewicz, PK Margolin, LG AF Smolarkiewicz, PK Margolin, LG TI MPDATA: A finite-difference solver for geophysical flows SO JOURNAL OF COMPUTATIONAL PHYSICS LA English DT Article DE advection; nonoscillatory approximations; computational fluid dynamics ID ADVECTION TRANSPORT ALGORITHM; SMALL IMPLICIT DIFFUSION; SCHEMES; FLUIDS; APPROXIMATIONS; EQUATIONS AB This article is a review of MPDATA, a class of methods for the numerical simulation of fluid flows based on the sign-preserving properties of upstream differencing. MPDATA was designed originally as an inexpensive alternative to flux-limited schemes for evaluating the advection of nonnegative thermodynamic variables (such as liquid water or water vapour) in atmospheric models. During the last decade, MPDATA has evolved from a simple advection scheme to a general approach for integrating the conservation laws of geophysical fluids on micro-to-planetary scales. The purpose of this paper is to summarize the basic concepts leading to a family of MPDATA schemes, to review existing MPDATA options, and to demonstrate the use of MPDATA to effectively construct two distinct types of models (elastic and anelastic) for complex geophysical flows. (C) 1998 Academic Press. C1 Natl Ctr Atmospher Res, Boulder, CO 80307 USA. Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Smolarkiewicz, PK (reprint author), Natl Ctr Atmospher Res, Pob 3000, Boulder, CO 80307 USA. EM smolar@ncar.ucar.edu; len@lanl.gov NR 38 TC 223 Z9 226 U1 0 U2 8 PU ACADEMIC PRESS INC ELSEVIER SCIENCE PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0021-9991 EI 1090-2716 J9 J COMPUT PHYS JI J. Comput. Phys. PD MAR 1 PY 1998 VL 140 IS 2 BP 459 EP 480 DI 10.1006/jcph.1998.5901 PG 22 WC Computer Science, Interdisciplinary Applications; Physics, Mathematical SC Computer Science; Physics GA ZF789 UT WOS:000072933400012 ER PT J AU Sulea, T Kurunczi, L Oprea, TI Simon, Z AF Sulea, T Kurunczi, L Oprea, TI Simon, Z TI MTD-ADJ: A multiconformational minimal topologic difference for determining bioactive conformers using adjusted biological activities SO JOURNAL OF COMPUTER-AIDED MOLECULAR DESIGN LA English DT Article DE 3D-QSAR methodology; acetylcholinesterase active site; acetic acid esters; adjusted biological activity; bioactive conformation; MTD ID STERIC DIFFERENCE; COBRA VENOM; ACETYLCHOLINESTERASE; HYDROLYSIS; STEROIDS; DYNAMICS; TORPEDO; BINDING; ESTERS AB The active conformation is part of a conformational mixture with experimental activity Y(exp), and is used in QSAR studies to extract more information regarding the ligand-receptor interaction. To reflect the relative amount (a) of the active conformation, we adjust Y(exp) : Y(adj) = Y(exp) - log alpha. We establish a quantitative structure-activity relationship (QSAR) between Y(adj) and 3D conformational characteristics for the acetylcholinesterase (AChE) hydrolysis rates of 25 acetic esters. The 3D-QSAR model was obtained using the adjusted multiconformational minimal steric/topologic difference (MTD-ADJ) method, optimizing the receptor map based on Yadj for each conformer. Y(adj) was updated during each step of the optimization process, alpha and Y(adj) are based on the Boltzmann distribution calculated using AM1 (MOPAC 6.0) relative energies of the COSMIC 90 derived conformers. The MTD-ADJ results are: (i) the 3D-QSAR models obtained by this procedure have significant statistical parameters and are similar to the unadjusted (MTD-MC, using Y(exp)) models; (ii) the selected bioactive conformations are extended, occupy cavity vertices and, for the same structures, have the same MTD value; and (iii) the optimized conformational map of the neutral ligands obtained from the MTD-ADJ model fits well in the active site of the crystallographic structure of AChE (from Torpedo californica). We propose a neutral ligands binding site model for AChE. Our results show that MTD-ADJ, which can be implemented in any 3D-QSAR method, is capable of providing additional information regarding the active conformations, and can be used to gain further insight into the ligand-receptor models for which no structural data are available. C1 FORSYLS Grp Formal Study Living Syst, RO-1900 Timisoara 14, Romania. Univ Med & Pharm, Fac Med, Dept Biophys, RO-1900 Timisoara, Romania. Univ Med & Pharm, Fac Pharm, Dept Chem Phys, RO-1900 Timisoara, Romania. Los Alamos Natl Lab, Theoret Biol & Biophys Grp T10, Los Alamos, NM USA. RP Oprea, TI (reprint author), Astra Hassle AB, Med Chem 1, S-43183 Molndal, Sweden. RI Oprea, Tudor/A-5746-2011 OI Oprea, Tudor/0000-0002-6195-6976 NR 25 TC 9 Z9 9 U1 0 U2 3 PU SPRINGER PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0920-654X J9 J COMPUT AID MOL DES JI J. Comput.-Aided Mol. Des. PD MAR PY 1998 VL 12 IS 2 BP 133 EP 146 DI 10.1023/A:1007913622673 PG 14 WC Biochemistry & Molecular Biology; Biophysics; Computer Science, Interdisciplinary Applications SC Biochemistry & Molecular Biology; Biophysics; Computer Science GA 100JJ UT WOS:000074812800004 PM 9690173 ER PT J AU Johnson, TL Fish, W Gorby, YA Tratnyek, PG AF Johnson, TL Fish, W Gorby, YA Tratnyek, PG TI Degradation of carbon tetrachloride by iron metal: Complexation effects on the oxide surface SO JOURNAL OF CONTAMINANT HYDROLOGY LA English DT Article DE iron oxide; passive film; groundwater remediation; dechlorination; corrosion ID PASSIVE FILM BREAKDOWN; BORATE BUFFER SOLUTION; COORDINATION CHEMISTRY; REDUCTIVE DISSOLUTION; MICROBIAL REDUCTION; CHROMATE REDUCTION; EDTA COMPLEXES; FERROUS IRON; ADSORPTION; FE(II) AB Dehalogenation of chlorinated aliphatic contaminants at the surface of zero-valent iron metal (Fe(0)) is mediated by the thin film of iron (hydr)oxides found on Fe(0) under environmental conditions. To evaluate the role this oxide film plays in the reduction of chlorinated methanes, carbon tetrachloride (CCl(4)) degradation by Fe(0) was studied under the influence of various anions, ligands, and initial CCl(4) concentrations ([P](0)). Over the range of conditions examined in these batch experiments, the reaction kinetics could be characterized by surface-area-normalized rate constants that were pseudo-first order for CCl(4) disappearance (k(CCl4)), and zero order for the appearance of dissolved Fe(2+) (k(Fe2+)). The rate of dechlorination exhibits saturation kinetics with respect to [P](0), suggesting that CCl(4) is transformed at a limited number of reactive surface sites. Because oxidation of Fe(0) by CCl(4) is the major corrosion reaction in these systems, k(Fe2+) also approaches a limiting value at high CCl(4) concentrations. The adsorption of borate strongly inhibited reduction of CCl(4), but a concomitant addition of chloride partially offset this effect by destabilizing the film. Redox active ligands (catechol and ascorbate), and those that are not redox active (EDTA and acetate), all decreased k(CCl4) (and k(Fe2+)). Thus, it appears that the relatively strong complexation of these Ligands at the oxide-electrolyte interface blocks the sites where weak interactions with the metal oxide lead to dehalogenation of chlorinated aliphatic compounds. (C) 1998 Elsevier Science B.V. C1 Oregon Grad Inst Sci & Technol, Dept Environm Sci & Engn, Portland, OR 97291 USA. Pacific NW Lab, Richland, WA 99352 USA. RP Tratnyek, PG (reprint author), Oregon Grad Inst Sci & Technol, Dept Environm Sci & Engn, POB 91000, Portland, OR 97291 USA. EM tratnyek@ese.ogi.edu NR 74 TC 109 Z9 118 U1 3 U2 34 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0169-7722 J9 J CONTAM HYDROL JI J. Contam. Hydrol. PD MAR 1 PY 1998 VL 29 IS 4 BP 379 EP 398 DI 10.1016/S0169-7722(97)00063-6 PG 20 WC Environmental Sciences; Geosciences, Multidisciplinary; Water Resources SC Environmental Sciences & Ecology; Geology; Water Resources GA ZE787 UT WOS:000072830900005 ER PT J AU Potapenko, SY AF Potapenko, SY TI Formation of solution inclusions in crystal under effect of solution flow SO JOURNAL OF CRYSTAL GROWTH LA English DT Article ID MORPHOLOGICAL INSTABILITY; HEATING CURRENT; GROWTH; DIFFUSION; INTERFACE; STABILITY; KINETICS; SURFACES; DYNAMICS; STEPS AB The morphological instability of a vicinal crystal face growing from a supersaturated solution is analyzed for arbitrary orientation of step motion, shear solution Bow and wave vector of the surface perturbation. It is shown that the condition of the inclusions formation can arise in two stages, First the steps bunch into macrosteps and then a lateral instability of the steps moving at the vicinity of the leading edge of the macrosteps develops under the influence of their diffusion field. (C) 1998 Elsevier Science B.V. All rights reserved. C1 Russian Acad Sci, Inst Appl Phys, Nizhnii Novgorod 603600, Russia. Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Potapenko, SY (reprint author), Russian Acad Sci, Inst Appl Phys, 46 Ulanov St, Nizhnii Novgorod 603600, Russia. NR 24 TC 12 Z9 15 U1 1 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-0248 J9 J CRYST GROWTH JI J. Cryst. Growth PD MAR PY 1998 VL 186 IS 3 BP 446 EP 455 DI 10.1016/S0022-0248(97)00542-3 PG 10 WC Crystallography; Materials Science, Multidisciplinary; Physics, Applied SC Crystallography; Materials Science; Physics GA ZE996 UT WOS:000072852400021 ER PT J AU Hong, J Lambers, ES Abernathy, CR Pearton, SJ Shul, RJ Hobson, WS AF Hong, J Lambers, ES Abernathy, CR Pearton, SJ Shul, RJ Hobson, WS TI Inductively coupled plasma etching of InGaP, AlInP, and AlGaP in Cl-2 and BCl3 chemistries SO JOURNAL OF ELECTRONIC MATERIALS LA English DT Article DE AlGaP; AlInP; InGaP; plasma etching ID HETEROJUNCTION BIPOLAR-TRANSISTORS; HIGH-TEMPERATURE OPERATION; SINGLE-HETEROJUNCTION; CW OPERATION; LASER-DIODES; INP; GAAS; HETEROSTRUCTURES; BASE AB Dry etching of InGaP, AlInP, and AlGaP in inductively coupled plasmas (ICP) is reported as a function of plasma chemistry (BCl3 or Cl-2, with additives of Ar, N-2, or H-2), source power, radio frequency chuck power, and pressure. Smooth anisotropic pattern transfer at peak etch rates of 1000-2000 Angstrom.min(-1) is obtained at low DC self-biases (-100V dc) and pressures (2 mTorr). The etch mechanism is characterized by a trade-off between supplying sufficient active chloride species to the surface to produce a strong chemical enhancement of the etch rate, and the efficient removal of the chlorinated etch products before a thick selvedge layer is formed. Cl-2 produces smooth surfaces over a wider range of conditions than does BCl3. C1 Univ Florida, Dept Mat Sci & Engn, Gainesville, FL 32611 USA. AT&T Bell Labs, Lucent Technol, Murray Hill, NJ 07974 USA. Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Hong, J (reprint author), Univ Florida, Dept Mat Sci & Engn, Gainesville, FL 32611 USA. NR 27 TC 4 Z9 4 U1 0 U2 4 PU MINERALS METALS MATERIALS SOC PI WARRENDALE PA 420 COMMONWEALTH DR, WARRENDALE, PA 15086 USA SN 0361-5235 J9 J ELECTRON MATER JI J. Electron. Mater. PD MAR PY 1998 VL 27 IS 3 BP 132 EP 137 DI 10.1007/s11664-998-0203-3 PG 6 WC Engineering, Electrical & Electronic; Materials Science, Multidisciplinary; Physics, Applied SC Engineering; Materials Science; Physics GA ZB992 UT WOS:000072528800007 ER PT J AU Hammad, KJ Vradis, GC AF Hammad, KJ Vradis, GC TI Asymptotic flow regimes in pulsatile flows of bingham plastics SO JOURNAL OF FLUIDS ENGINEERING-TRANSACTIONS OF THE ASME LA English DT Article ID VISCOUS DISSIPATION; HEAT-TRANSFER; CONTRACTIONS C1 Polytech Univ, Dept Mech Aerosp & Mfg Engn, Metrotech Ctr 6, Brooklyn, NY 11201 USA. RP Hammad, KJ (reprint author), Pacific NW Lab, Fluid Dynam Grp, POB 999,Battelle Blvd, Richland, WA 99352 USA. NR 5 TC 2 Z9 2 U1 0 U2 0 PU ASME-AMER SOC MECHANICAL ENG PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 0098-2202 J9 J FLUID ENG-T ASME JI J. Fluids Eng.-Trans. ASME PD MAR PY 1998 VL 120 IS 1 BP 211 EP 213 DI 10.1115/1.2819653 PG 3 WC Engineering, Mechanical SC Engineering GA ZE038 UT WOS:000072751100035 ER PT J AU Barshick, SA AF Barshick, SA TI Analysis of accelerants and fire debris using aroma detection technology SO JOURNAL OF FORENSIC SCIENCES LA English DT Article DE forensic science; accelerants; fire debris; arson; aroma detection; gas sensor arrays; artificial neural network ID CHROMATOGRAPHY-MASS-SPECTROMETRY; CHEMICAL-ANALYSIS; ARSON ANALYSIS; GASOLINE AB The purpose of this work was to investigate the utility of electronic aroma detection technologies for the detection and identification of ignitable liquid accelerants and their residues in suspected arson debris. Through the analysis of "known" accelerants and residues, a trained neural network was developed for classifying fire debris samples. Three "unknown" items taken from actual fire debris that had contained the fuels, gasoline, kerosene, and diesel fuel, were classified using this neural network. One item, taken from the area known to have contained diesel fuel, was correctly identified as diesel fuel residue every time. For the other two "unknown" items, variations in sample composition, possibly due to the effects of weathering or increased sample humidities, were shown to influence the sensor response. This manifested itself in inconsistent fingerprint patterns and incorrect classifications by the neural network. Sorbent sampling prior to aroma detection was demonstrated to reduce these problems and allowed improved neural network classification of the remaining items which were identified as kerosene and gasoline residues. C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Barshick, SA (reprint author), Oak Ridge Natl Lab, POB 2008, Oak Ridge, TN 37831 USA. NR 28 TC 23 Z9 23 U1 3 U2 6 PU AMER SOC TESTING MATERIALS PI W CONSHOHOCKEN PA 100 BARR HARBOR DR, W CONSHOHOCKEN, PA 19428-2959 USA SN 0022-1198 J9 J FORENSIC SCI JI J. Forensic Sci. PD MAR PY 1998 VL 43 IS 2 BP 284 EP 293 PG 10 WC Medicine, Legal SC Legal Medicine GA ZE009 UT WOS:000072748000004 ER PT J AU Belgrader, P Smith, JK Weedn, VW Northrup, MA AF Belgrader, P Smith, JK Weedn, VW Northrup, MA TI Rapid PCR for identity testing using a battery-powered miniature thermal cycler SO JOURNAL OF FORENSIC SCIENCES LA English DT Article DE forensic science; rapid PCR; DNA typing; microchip ID ELECTROPHORESIS CHIPS; DNA; HYBRIDIZATION; ARRAYS AB A microfabricated, battery-powered thermal cycler was implemented in PCR-based DNA typing for human identification. HLA DQ alpha and an STR tripler were PCR amplified using a device known as the Miniature Analytical Thermal Cycling Instrument (MATCI). The extremely efficient heating properties of the MATCI enabled thermal cycling to be completed in as little as 21 min. In addition, the feasibility of using the real-time fluorescent detection system of the MATCI was demonstrated. The successful application of this portable, prototype device to forensic identity testing is a significant milestone towards the eventual development of a completely integrated DNA testing instrument that would also incorporate sample preparation and allele detection. C1 Univ Calif Lawrence Livermore Natl Lab, Biol & Biotechnol Res Program, Livermore, CA 94550 USA. Armed Forces Inst Pathol, DNA Identificat Lab, Rockville, MD 20850 USA. Cepheid, Sunnyvale, CA 94089 USA. RP Belgrader, P (reprint author), Univ Calif Lawrence Livermore Natl Lab, Biol & Biotechnol Res Program, POB 808,Mail Stop L452, Livermore, CA 94550 USA. NR 16 TC 44 Z9 45 U1 0 U2 1 PU AMER SOC TESTING MATERIALS PI W CONSHOHOCKEN PA 100 BARR HARBOR DR, W CONSHOHOCKEN, PA 19428-2959 USA SN 0022-1198 J9 J FORENSIC SCI JI J. Forensic Sci. PD MAR PY 1998 VL 43 IS 2 BP 315 EP 319 PG 5 WC Medicine, Legal SC Legal Medicine GA ZE009 UT WOS:000072748000008 PM 9544539 ER PT J AU Voelz, NJ McArthur, JV Rader, RB AF Voelz, NJ McArthur, JV Rader, RB TI Upstream mobility of the Asiatic clam Corbicula fluminea: Identifying potential dispersal agents SO JOURNAL OF FRESHWATER ECOLOGY LA English DT Article AB Based on studies conducted in 1987 and 1993, we have determined that the Asiatic clam, Corbicula fluminea, has moved upstream at least 1.2 km/year in a southeastern U.S. blackwater stream. Since these studies were done in a protected area (the Savannah River Site, South Carolina), our data suggest that this was a process unaided by humans. In addition, the upstream movement has been halted by a large, permanent wetland and two culverts. Because the Asiatic clam has not colonized headwater areas, where several wetlands ern:st, this precludes the aided movement of C. fluminea by waterfowl. It is possible that fish are partially responsible for dispersing C. fluminea, at least for longer distances. We suggest that unassisted upstream movements may also be an important dispersal mechanism for this species. C1 Univ Georgia, Savannah River Ecol Lab, Aiken, SC 29802 USA. RP Voelz, NJ (reprint author), St Cloud State Univ, Dept Sci Biol, MS 262, St Cloud, MN 56301 USA. NR 16 TC 18 Z9 18 U1 1 U2 8 PU OIKOS PUBL INC PI LA CROSSE PA PO BOX 2558, LA CROSSE, WI 54601 USA SN 0270-5060 J9 J FRESHWATER ECOL JI J. Freshw. Ecol. PD MAR PY 1998 VL 13 IS 1 BP 39 EP 45 DI 10.1080/02705060.1998.9663589 PG 7 WC Ecology; Limnology SC Environmental Sciences & Ecology; Marine & Freshwater Biology GA YZ929 UT WOS:000072309100006 ER PT J AU Anderson, JW AF Anderson, JW TI What is the nature of the future marketplace in which fusion will compete? The potential marketplace for fusion SO JOURNAL OF FUSION ENERGY LA English DT Article C1 Princeton Plasma Phys Lab, Princeton, NJ 08543 USA. RP Anderson, JW (reprint author), Princeton Plasma Phys Lab, POB 451, Princeton, NJ 08543 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU PLENUM PUBL CORP PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 0164-0313 J9 J FUSION ENERG JI J. Fusion Energy PD MAR PY 1998 VL 17 IS 1 BP 11 EP 15 DI 10.1023/A:1022509114172 PG 5 WC Nuclear Science & Technology SC Nuclear Science & Technology GA ZW755 UT WOS:000074444900003 ER PT J AU Nevins, WM AF Nevins, WM TI A review of confinement requirements for advanced fuels SO JOURNAL OF FUSION ENERGY LA English DT Article DE confinement requirements; advanced fuels ID CROSS-SECTIONS; FUSION POWER; ENERGY AB The energy confinement requirements for burning D-He-3, D-D, or P-B-11 are reviewed, with particular attention to the effects of helium ash accumulation. It is concluded that the DT cycle will lead to the more compact and economic fusion power reactor. The substantially less demanding requirements for ignition in DT (the n(e) tau(E) T required for ignition in DT is smaller than that of the nearest advanced fuel, D-He-3, by a factor of 50) will allow ignition, or significant fusion gain, in a smaller device; while the higher fusion power density (the fusion power density in DT is higher than that of D-3He by a factor of 100 at the same plasma pressure) allows for a more compact and economic device at fixed fusion power. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Nevins, WM (reprint author), Univ Calif Lawrence Livermore Natl Lab, POB 808,L-637, Livermore, CA 94550 USA. NR 21 TC 17 Z9 17 U1 2 U2 10 PU PLENUM PUBL CORP PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 0164-0313 J9 J FUSION ENERG JI J. Fusion Energy PD MAR PY 1998 VL 17 IS 1 BP 25 EP 32 DI 10.1023/A:1022513215080 PG 8 WC Nuclear Science & Technology SC Nuclear Science & Technology GA ZW755 UT WOS:000074444900005 ER PT J AU Peng, M AF Peng, M TI Spherical torus pathway to fusion power SO JOURNAL OF FUSION ENERGY LA English DT Article DE spherical torus; fusion power ID TOKAMAK; PLASMAS AB Spherical Torus (ST) as an example of confinement concept innovation to enable a potentially attractive pathway to fusion power is discussed. Given the anticipated high performance in small size, the ST plasma could be used to stimulate innovation also in engineering, technology, and material combinations to provide a smarter, cheaper, faster pathway. This pathway could complement the mainline program based on the tokamak in making the desired progress in fusion energy sciences. The ST pathway could include a small VNS (Volume Neutron Source) with low fusion amplification (Q similar to 1-2) for Fusion Energy Development (energy technology) and a small Pilot Plant with high Q (similar to 15-30) to practice Fusion Power Demonstration. Success in these steps also enhances the possibility for competitive non-electric applications of interest to society in time scales shorter than electric power generation. The scientific basis for these possibilities will be tested in the U.S. by the Proof of Principle experiment NSTX (National Spherical Torus Experiment) presently being built, and could be completed by a Proof of Performance and Optimization experiment such as a small DTST (Deuterium-Tritium Spherical Torus). Utilization of facilities and equipment already available in the U.S. would minimize the time and cost for these experiments and accelerate the approach to the stage of Fusion Energy Development. C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Peng, M (reprint author), Princeton Plasma Phys Lab, POB 451, Princeton, NJ 08543 USA. NR 68 TC 13 Z9 15 U1 0 U2 4 PU PLENUM PUBL CORP PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 0164-0313 J9 J FUSION ENERG JI J. Fusion Energy PD MAR PY 1998 VL 17 IS 1 BP 45 EP 59 DI 10.1023/A:1022569300059 PG 15 WC Nuclear Science & Technology SC Nuclear Science & Technology GA ZW755 UT WOS:000074444900008 ER PT J AU Olsson, A Andersson, L Eriksson, AI Clemmons, J Erlandsson, RE Reeves, G Hughes, T Murphee, JS AF Olsson, A Andersson, L Eriksson, AI Clemmons, J Erlandsson, RE Reeves, G Hughes, T Murphee, JS TI Freja studies of the current-voltage relation in substorm-related events SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID PARTICLE-PRECIPITATION; ELECTRIC-FIELDS; POTENTIAL DIFFERENCE; HIGH-ALTITUDE; AURORA; MODEL; SATELLITE; FLUXES; DISTRIBUTIONS; SURGE AB Field-aligned currents and electrostatic potentials play important roles in the coupling between the magnetosphere and the ionosphere. If one assumes that the ionosphere-magnetosphere potential difference is mainly due to the mirror force, one can use the single particle adiabatic kinetic theory to describe the system. From this theory, a linear relationship j(parallel to)=KV between field-aligned current density j(parallel to) and potential drop V along the same field line can be derived, provided that the potential drop is not too large and not too small. With rare exceptions, observational tests of this relation have mainly concentrated on quiet magnetospheric situations, with acceleration voltages V less than or similar to 5 kV. Here we use observations from the Freja satellite of precipitating auroral electrons at 1.700 km altitude to study substorm related events, with acceleration voltages up to 20 keV. The observations are found to be consistent with a linear current-voltage relation even in these conditions, although with values of the field aligned K lower than previously reported (1-5 x 10(-11) S/m(2)). This can be explained by lower densities and higher characteristic electron energies in the magnetospheric source region of the precipitating electrons. We analyze the data by three different methods, which are all found to be in general agreement. The results are in agreement with a previous study [Olsson et al., 1996 b], where the spectra of precipitating electrons were indirectly infered by inversion of data from the EISCAT incoherent scatter radar, thereby validating the use of radar data for studies of auroral electrons. Comparisons with previous studies are made, emphasizing the dependence of the results on the type of auroral structure and magnetospheric conditions. C1 Swedish Inst Space Phys, Uppsala Div, S-75591 Uppsala, Sweden. Swedish Inst Space Phys, Kiruna Div, S-98128 Kiruna, Sweden. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Johns Hopkins Univ, Appl Phys Lab, Laurel, MD USA. Univ Calif Los Alamos Natl Lab, Los Alamos, NM USA. Natl Res Council Canada, Herzberg Inst Astrophys, Ottawa, ON K1A 0R6, Canada. Univ Calgary, Dept Phys & Astron, Calgary, AB T2N 1N4, Canada. RP Olsson, A (reprint author), Swedish Inst Space Phys, Uppsala Div, S-75591 Uppsala, Sweden. EM ao@irfu.se; laila@irf.se; jhc@leppow.gsfc.nasa.gov; boberlandson@spacemail.jhuapl.edu; reeves@Lanl.gov; hughes@canott.sp-agency.ca; mur-phree@.phys.ucalgary.ca RI Eriksson, Anders/C-2887-2009; Reeves, Geoffrey/E-8101-2011 OI Reeves, Geoffrey/0000-0002-7985-8098 NR 38 TC 32 Z9 32 U1 0 U2 3 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA J9 J GEOPHYS RES-SPACE JI J. Geophys. Res-Space Phys. PD MAR 1 PY 1998 VL 103 IS A3 BP 4285 EP 4301 DI 10.1029/97JA00560 PG 17 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA ZA782 UT WOS:000072401200029 ER PT J AU Shiokawa, K Baumjohann, W Haerendel, G Paschmann, G Fennell, JF Friis-Christensen, E Luhr, H Reeves, GD Russell, CT Sutcliffe, PR Takahashi, K AF Shiokawa, K Baumjohann, W Haerendel, G Paschmann, G Fennell, JF Friis-Christensen, E Luhr, H Reeves, GD Russell, CT Sutcliffe, PR Takahashi, K TI High-speed ion flow, substorm current wedge, and multiple Pi 2 pulsations SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article; Proceedings Paper CT Chapman Conference on the Earths Magnetotail - New Perspectives CY NOV 05-09, 1996 CL KANAZAWA, JAPAN ID CENTRAL PLASMA SHEET; TAIL CURRENT SHEET; MAGNETIC PULSATIONS; CURRENT DISRUPTION; GEOMAGNETIC TAIL; NEUTRAL SHEET; MAGNETOTAIL; ONSET; EVENT; MODEL AB We have studied the onset timing of earthward high-speed ion flow observed by the AMPTE/IRM satellite at 12.3 Earth radii (R-E) and 0100 MLT in the central plasma sheet during an isolated substorm event on March 1, 1985. The timing of this onset is compared with that of the substorm current wedge and Pi 2 magnetic pulsations observed by a large number of ground-based stations and the AMPTE/CCE, GOES 5, and ISEE 1 satellites and with that of high-energy particle injection observed at Los Alamos geosynchronous satellite 1982-019. The onset of earthward high-speed how is observed 3 min before the onset of the global current wedge formation and 6 min before the onset of high-energy particle injection. The three bursts of the high-speed flow observed at AMPTE/IRM are likely to correspond to three compressional pulses observed at AMPTE/CCE at 6 R-E and three Pi 2 wave packets observed at midlatitude ground stations. On the basis of these observations we conclude that the substorm current wedge is caused by inertia current and the current due to flow shear at the braking point of the earthward high-speed flow during the initial stage of the substorm expansion phase. The braking point is well separated from the near-Earth neutral line. It is also suggested that the compressional pulses and fluctuations of field-aligned currents generated at the how braking point can be the initial cause of the Pi 2 magnetic pulsations in the inner magnetosphere. C1 Max Planck Inst Extraterr Phys, D-85740 Garching, Germany. Aerospace Corp, El Segundo, CA 90245 USA. Danish Meteorol Inst, DK-2100 Copenhagen, Denmark. Geoforschungszentrum Potsdam, D-14473 Potsdam, Germany. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Univ Calif Los Angeles, Inst Geophys & Planetary Phys, Los Angeles, CA 90024 USA. CSIR, Hermanus Magnet Observ, ZA-7200 Hermanus, South Africa. Nagoya Univ, Solar Terr Environm Lab, Toyokawa 442, Japan. RP Shiokawa, K (reprint author), Max Planck Inst Extraterr Phys, D-85740 Garching, Germany. EM shiokawa@stelab.nagoya-u.ac.jp RI Baumjohann, Wolfgang/A-1012-2010; Sutcliffe, Peter/E-8124-2014; Reeves, Geoffrey/E-8101-2011; OI Baumjohann, Wolfgang/0000-0001-6271-0110; Reeves, Geoffrey/0000-0002-7985-8098; Russell, Christopher/0000-0003-1639-8298 NR 54 TC 222 Z9 230 U1 2 U2 12 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA J9 J GEOPHYS RES-SPACE JI J. Geophys. Res-Space Phys. PD MAR 1 PY 1998 VL 103 IS A3 BP 4491 EP 4507 DI 10.1029/97JA01680 PG 17 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA ZA782 UT WOS:000072401200043 ER PT J AU Heber, B Bothmer, V Droge, W Kunow, H Muller-Mellin, R Sierks, H Wibberenz, G Ferrando, P Raviart, A Paizis, C Potgieter, MS Burger, RA Hattingh, M Haasbroek, LJ McComas, D AF Heber, B Bothmer, V Droge, W Kunow, H Muller-Mellin, R Sierks, H Wibberenz, G Ferrando, P Raviart, A Paizis, C Potgieter, MS Burger, RA Hattingh, M Haasbroek, LJ McComas, D TI Latitudinal distribution of > 106 MeV protons and its relation to the ambient solar wind in the inner southern and northern heliosphere: Ulysses Cosmic and Solar Particle Investigation Kiel Electron Telescope Results SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID MODULATION; RAY; CONSEQUENCES AB We present observations and model calculations of the modulated intensities of galactic cosmic ray protons above 106 MeV/n along the Ulysses trajectory. Data are taken by the Cosmic and Solar Particle Investigation (COSPIN) Kiel Electron Telescope (KET) from spring 1993 to fall 1996. During this time period solar activity decreased and galactic cosmic rays recovered, To separate spatial from temporal variations we used the University of Chicago measurements from IMP 8 near Earth and compare the residual spatial variation with time independent modulation models. According to standard drift dominated modulation model, one would expect a radial gradient of approximate to 2%/AU and a latitudinal gradient of approximate to 1.2%/degree in both hemispheres. The measured mean radial gradient of approximate to 3%/AU is within the uncertainties in good agreement with the model predictions, However, the measured mean latitudinal gradient has a value of (0.33 +/- 0.04)%/degree in both hemispheres at intermediate latitudes and is by a factor of 4 lower than expected, In the modified models the latitudinal gradient is in agreement with the measured ones when we increase the diffusion coefficient Mss perpendicular to the magnetic field in polar direction to a value of 15% of the diffusion coefficient parallel to the magnetic field, The latitudinal gradients >106 MeV protons calculated by modified modulation models are in very good agreement with the measured ones at intermediate latitudes, At lower latitudes, when Ulysses is embedded in the streamer belt, the models predict approximately the same latitudinal gradient than at intermediate latitudes, whereas the measured ones are significant smaller, or even vanishing, The observations support the previous conclusion from Paizis et al. [1995] that a significant latitudinal gradient is only observed when Ulysses is outside the streamer belt, Another remarkable observation is the difference of the radial gradient G(r) at similar to 3.5 AU in the southern (G(r) approximate to 3.5%/AU) and in the northern hemisphere (G(r) approximate to 2.3%/AU), Probable reasons for the significantly lower radial gradient in the northern hemisphere can be either a spatial asymmetry of the heliosphere or temporal variations. C1 Univ Kiel, Inst Expt & Angew Phys, D-24118 Kiel, Germany. Potchefstroom Univ Christian Higher Educ, Space Res Unit, ZA-2520 Potchefstroom, South Africa. CEA Saclay, DSM, DAPNIA, Serv Astrophys, F-91191 Gif Sur Yvette, France. Univ Calif Los Alamos Natl Lab, Los Alamos, NM USA. Univ Milan, CNR, Ist Fis Cosm, I-20133 Milan, Italy. RP Heber, B (reprint author), Univ Kiel, Inst Expt & Angew Phys, D-24118 Kiel, Germany. NR 31 TC 20 Z9 20 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA J9 J GEOPHYS RES-SPACE JI J. Geophys. Res-Space Phys. PD MAR 1 PY 1998 VL 103 IS A3 BP 4809 EP 4816 DI 10.1029/97JA01984 PG 8 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA ZA782 UT WOS:000072401200071 ER PT J AU Stroud, PD AF Stroud, PD TI Adaptive simulated pilot SO JOURNAL OF GUIDANCE CONTROL AND DYNAMICS LA English DT Article C1 Univ Calif Los Alamos Natl Lab, Technol & Safety Assessment Div, Tech Staff, Los Alamos, NM 87545 USA. RP Stroud, PD (reprint author), Univ Calif Los Alamos Natl Lab, Technol & Safety Assessment Div, Tech Staff, POB 1663, Los Alamos, NM 87545 USA. NR 5 TC 3 Z9 3 U1 0 U2 0 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091 USA SN 0731-5090 J9 J GUID CONTROL DYNAM JI J. Guid. Control Dyn. PD MAR-APR PY 1998 VL 21 IS 2 BP 352 EP 354 DI 10.2514/2.7606 PG 3 WC Engineering, Aerospace; Instruments & Instrumentation SC Engineering; Instruments & Instrumentation GA ZA178 UT WOS:000072336800021 ER PT J AU Ryan, TJ AF Ryan, TJ TI Larval life history and abundance of a rare salamander, Eurycea junaluska SO JOURNAL OF HERPETOLOGY LA English DT Article ID DECLINING AMPHIBIAN POPULATIONS; NATURAL FLUCTUATIONS; HUMAN IMPACTS; METAMORPHOSIS; BISLINEATA; CAROLINA; PERIODS; GROWTH; AGE AB The larval life history of Eurycea junaluska was studied in three southwestern North Carolina populations Populations were sampled quarterly over a 13 mo period and size-class analyses were used to evaluate the pattern of larval growth and metamorphosis. Young of the year appeared in the late spring and experienced rapid growth through the first summer. Growth slowed in the second year and metamorphosis usually occured in the summer at about 25.5 mo post-hatching, although some data suggest that either 1 yr or 3 yr larval periods may be possible The overall larval growth rate of E. junaluska is estimated at 1.27 mm/mo, much higher than in other stream-dwelling plethodontids. This species typically represents only about 10% of the larval Eurycea community, with adults even less common. The relative scarcity of individuals and the significant distance between documented populations raises concern about long term population viability in the face of declines due to either natural or anthropogenic causes, or both. C1 Highlands Biol Stn, Highlands, NC 28741 USA. Western Carolina Univ, Dept Biol, Cullowhee, NC 28723 USA. RP Ryan, TJ (reprint author), Savannah River Ecol Lab, Drawer E, Aiken, SC 29802 USA. NR 38 TC 8 Z9 10 U1 0 U2 1 PU SOC STUDY AMPHIBIANS REPTILES PI ST LOUIS PA C/O ROBERT D ALDRIDGE, ST LOUIS UNIV, DEPT BIOLOGY, 3507 LACLEDE, ST LOUIS, MO 63103 USA SN 0022-1511 J9 J HERPETOL JI J. Herpetol. PD MAR PY 1998 VL 32 IS 1 BP 10 EP 17 DI 10.2307/1565473 PG 8 WC Zoology SC Zoology GA ZF094 UT WOS:000072862000002 ER PT J AU Desprez, F Dongarra, J Rastello, F Robert, Y AF Desprez, F Dongarra, J Rastello, F Robert, Y TI Determining the idle time of a tiling: New results SO JOURNAL OF INFORMATION SCIENCE AND ENGINEERING LA English DT Article DE distributed arrays; redistribution; block-cyclic distribution; scheduling; MPI (Message Passing Interface); HFP (High Performance Fortran) AB In the framework of fully permutable loops, tiling has been studied extensively as a source-to-source program transformation. We build upon recent results by Hogsted, Carter, and Ferrante [12], who aimed at determining the cumulated idle time spent by all processors while executing the partitioned (tiled) computation domain. We propose new, much shorter proofs of all their results and extend these in several important directions. More precisely, we provide an accurate solution for all values of the rise parameter that relates the shape of the iteration space to that of the tiles, and for all possible distributions of the tiles to processors. In contrast, the authors in [12] dealt only with a limited number of cases and provided upper bounds rather than exact formulas. C1 Ecole Normale Super Lyon, LIP, F-69364 Lyon 07, France. Univ Tennessee, Dept Comp Sci, Knoxville, TN 37996 USA. Oak Ridge Natl Lab, Math Sci Sect, Oak Ridge, TN 37831 USA. RP Desprez, F (reprint author), Ecole Normale Super Lyon, LIP, F-69364 Lyon 07, France. EM desprez@ens-lyon.fr; dongarra@cs.utk.edu; frastell@ens-lyon.fr; yrobert@cs.utk.edu RI Dongarra, Jack/E-3987-2014 NR 24 TC 9 Z9 9 U1 0 U2 0 PU INST INFORMATION SCIENCE PI TAIPEI PA ACADEMIA SINICA, TAIPEI 115, TAIWAN SN 1016-2364 J9 J INF SCI ENG JI J. Inf. Sci. Eng. PD MAR PY 1998 VL 14 IS 1 BP 167 EP 190 PG 24 WC Computer Science, Information Systems SC Computer Science GA ZR070 UT WOS:000073932600008 ER PT J AU Robinett, RD Petterson, BJ Farenholtz, JC AF Robinett, RD Petterson, BJ Farenholtz, JC TI Lag-stabilized force feedback damping SO JOURNAL OF INTELLIGENT & ROBOTIC SYSTEMS LA English DT Article DE lag-stabilization; force feedback; damping; robot AB A lag-stabilized, force feedback controller for damping initial and residual oscillations of a planar, cantilevered flexible arm has been analytically developed and experimentally implemented on a commercial robot. The controller feeds back force sensor measurements that are delayed in time and proportional to the displacement (angular orientation) of the arm in order to damp the oscillation. As a result of the lag (contrary to popular belief), the controlled robot system is stable and provides tunable performance on a Cincinnati Milacron T3-786 robot. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Robinett, RD (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. NR 3 TC 8 Z9 8 U1 0 U2 0 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0921-0296 J9 J INTELL ROBOT SYST JI J. Intell. Robot. Syst. PD MAR PY 1998 VL 21 IS 3 BP 277 EP 285 DI 10.1023/A:1007967028141 PG 9 WC Computer Science, Artificial Intelligence; Robotics SC Computer Science; Robotics GA ZB661 UT WOS:000072494900005 ER PT J AU Latli, B Morimoto, H Williams, PG Casida, JE AF Latli, B Morimoto, H Williams, PG Casida, JE TI Photoaffinity radioligand for NADH : ubiquinone oxidoreductase: [S-(CH2)-H-3](trifluoromethyl)diazirinyl-pyridaben SO JOURNAL OF LABELLED COMPOUNDS & RADIOPHARMACEUTICALS LA English DT Article DE lithium borotritide; NADH : ubiquinone oxidoreductase; photoaffinity; pyridaben; radioligand; tritium labeling ID NICOTINIC ACETYLCHOLINE-RECEPTOR; COMPLEX-I; PARKINSONS-DISEASE; OXIDATIVE STRESS; INHIBITORS; ACARICIDE; DEFECT AB Pyridaben is a new and very potent insecticide and miticide that acts by inhibiting the activity of NADH:ubiquinone oxidoreductase (the most complex of all the respiratory enzymes). The binding site, presumed to be the same as that of rotenone and fenazaquin, resides at an unknown location within the 43-polypeptide-subunit Complex I. To define the structure of the pyridaben-inhibition site(s), we prepared [S-C3H2](trifluoromethyl)diazirinylphenylacetyl as a photoaffinity probe. Tritium was incorporated by reducing 4-(trifluoromethyl)diazirinylphenylacetyl fluoride to the benzyl alcohol with freshly prepared (LiBH4)-H-3 at 97% tritium enrichment. The tritium-labeled alcohol was converted to the benzyl bromide derivative and coupled to 2-tert-butyl-4-chloro-5-mercapto-3(2H)-pyridazinone to obtain the photoaffinity probe (56 Ci/mmol) with an IC50 of 3.0 nM for NADH:ubiquinone oxidoreductase activity of bovine heart electron transport particles. [S-C3H2](Trifluoromethyl)diazirinyl-pyridaben is an improved photoaffinity radioligand combining outstanding potency for inhibiting NADH:ubiquinone oxidoreductase activity, high specific activity close to the theoretical value, and a preferred photolabile substituent (known to combine high reactivity and generation of a carbene species at wavelengths not damaging to proteins). C1 Univ Calif Berkeley, Dept Environm Sci Policy & Management, Environm Chem & Toxicol Lab, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Natl Tritium Labelling Facil & Struct Biol Div, Berkeley, CA 94720 USA. RP Latli, B (reprint author), Univ Calif Berkeley, Dept Environm Sci Policy & Management, Environm Chem & Toxicol Lab, Berkeley, CA 94720 USA. NR 33 TC 10 Z9 10 U1 1 U2 3 PU JOHN WILEY & SONS LTD PI W SUSSEX PA BAFFINS LANE CHICHESTER, W SUSSEX PO19 1UD, ENGLAND SN 0362-4803 J9 J LABELLED COMPD RAD JI J. Label. Compd. Radiopharm. PD MAR PY 1998 VL 41 IS 3 BP 191 EP 199 PG 9 WC Biochemical Research Methods; Chemistry, Medicinal; Chemistry, Analytical SC Biochemistry & Molecular Biology; Pharmacology & Pharmacy; Chemistry GA ZA420 UT WOS:000072361700003 ER PT J AU Larsen, FH Jakobsen, HJ Ellis, PD Nielsen, NC AF Larsen, FH Jakobsen, HJ Ellis, PD Nielsen, NC TI QCPMG-MAS NMR of half-integer quadrupolar nuclei SO JOURNAL OF MAGNETIC RESONANCE LA English DT Article ID MAGNETIC-RESONANCE; SPIN-ECHO; RELATIVE ORIENTATION; CENTRAL TRANSITION; RB-87 NMR; SPECTROSCOPY; RELAXATION; COUPLINGS; SPECTRA; RBCLO4 AB By combination of fast magic-angle spinning (MAS) and detection of the free-induction decay during a rotor-synchronized quadrupolar Carr-Purcell-Meiboom-Gill (QCPMG) train of refocusing pulses, the sensitivity of quadrupolar-echo MAS NMR spectra for the central transition of half-integer quadrupolar nuclei exhibiting large quadrupolar couplings may be significantly enhanced. Enhancements by an order of magnitude may easily be realized while maintaining information about the anisotropic interactions. In the present study the so-called QCPMG-MAS experiment is demonstrated experimentally and by numerical simulations for the two Rb-87 sites in Rb2SO4. (C) 1998 Academic Press. C1 Aarhus Univ, Dept Chem, Instrument Ctr Solid State NMR Spect, DK-8000 Aarhus C, Denmark. Pacific NW Natl Lab, Environm Mol Sci Lab, Richland, WA 99352 USA. RP Nielsen, NC (reprint author), Aarhus Univ, Dept Chem, Instrument Ctr Solid State NMR Spect, DK-8000 Aarhus C, Denmark. RI Larsen, Flemming/A-5255-2015 OI Larsen, Flemming/0000-0001-5180-6870 NR 34 TC 80 Z9 81 U1 1 U2 20 PU ACADEMIC PRESS INC PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 1090-7807 J9 J MAGN RESON JI J. Magn. Reson. PD MAR PY 1998 VL 131 IS 1 BP 144 EP 147 DI 10.1006/jmre.1997.1341 PG 4 WC Biochemical Research Methods; Physics, Atomic, Molecular & Chemical; Spectroscopy SC Biochemistry & Molecular Biology; Physics; Spectroscopy GA ZH656 UT WOS:000073133900019 PM 9533917 ER PT J AU Amoureux, JP Pruski, M Lang, DP Fernandez, C AF Amoureux, JP Pruski, M Lang, DP Fernandez, C TI The effect of RF power and spinning speed on MQMAS NMR SO JOURNAL OF MAGNETIC RESONANCE LA English DT Article ID QUADRUPOLAR NUCLEI; MAS; SPECTROSCOPY; ROTOR AB It is known that the patterns of spinning sidebands observed in the multiple-quantum dimension of MQMAS spectra are often significantly wider than expected from the anisotropies of relevant interactions. It has been recently shown by others that these sidebands are generated due to the rotor-driven reorientations that the quadrupole tensors of the crystallites undergo during the evolution period between the multiple-and single-quantum conversion processes. We present an experimental and theoretical study of the effects of the spinning speed nu(R) and RF field strength nu(RF) on the development of these sideband patterns. The theoretical analysis relies upon numerical simulations and includes propagation of the density matrix during the entire MQMAS experiment. The possibility of additional rotational encoding during the RF pulses is discussed. Both the theoretical and experimental results show the benefits of using the highest available nu(R) and nu(RF). (C) 1998 Academic Press. C1 Univ Sci & Technol Lille, CNRS URA801, Lab Dynam & Struct Mat Mol, F-59655 Villeneuve Dascq, France. Ames Lab, Ames, IA 50011 USA. RP Amoureux, JP (reprint author), Univ Sci & Technol Lille, CNRS URA801, Lab Dynam & Struct Mat Mol, F-59655 Villeneuve Dascq, France. RI fernandez, christian/C-3158-2008 OI fernandez, christian/0000-0002-5476-3148 NR 16 TC 47 Z9 47 U1 2 U2 12 PU ACADEMIC PRESS INC PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 1090-7807 J9 J MAGN RESON JI J. Magn. Reson. PD MAR PY 1998 VL 131 IS 1 BP 170 EP 175 DI 10.1006/jmre.1997.1275 PG 6 WC Biochemical Research Methods; Physics, Atomic, Molecular & Chemical; Spectroscopy SC Biochemistry & Molecular Biology; Physics; Spectroscopy GA ZH656 UT WOS:000073133900025 ER PT J AU Pechan, MJ Fullerton, EE Schuller, IK AF Pechan, MJ Fullerton, EE Schuller, IK TI Sources of interface magnetization and interface anisotropy in Fe/Cu multilayers as revealed by thermal behavior SO JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS LA English DT Article DE multilayers; interface; anisotropy; magnetization; temperature dependence ID MODULATED THIN-FILMS; TEMPERATURE-DEPENDENCE; SUPERLATTICES; FE; MOSSBAUER; SURFACE AB Sources on interface magnetization and anisotropy in Fe/Cu multilayers have been investigated via thermal behavior using DC magnetization and ferromagnetic resonance techniques. The samples were prepared by DC sputtering resulting in equal thickness elemental layers ranging in modulation wavelength from 1 to 30 nm. The interface anisotropy remains nearly constant at 0.32 erg/cm(2) through the temperature range 4-300 K, which is in stark contrast to large thermal effects observed in Ni-based systems, but is consistent with weak thermal Variations of the crystal field in bulk Fe. Both the interface and volume Fe magnetizations follow Bloch T-3/2 behavior? but whereas the volume Fe coefficient matches the bulk value of 3.5 x 10(-6)K(-3/2), the interface coefficient is 17 times greater. This indicates an interface Fe-Fe exchange which is much weaker than would be expected at a free Fe surface. (C) 1998 Elsevier Science B.V. All rights reserved. C1 Miami Univ, Dept Phys, Oxford, OH 45056 USA. Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. Univ Calif San Diego, Dept Phys, La Jolla, CA 92093 USA. RP Pechan, MJ (reprint author), Miami Univ, Dept Phys, Oxford, OH 45056 USA. RI Fullerton, Eric/H-8445-2013 OI Fullerton, Eric/0000-0002-4725-9509 NR 29 TC 9 Z9 10 U1 1 U2 5 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0304-8853 J9 J MAGN MAGN MATER JI J. Magn. Magn. Mater. PD MAR PY 1998 VL 183 IS 1-2 BP 19 EP 24 DI 10.1016/S0304-8853(97)01064-0 PG 6 WC Materials Science, Multidisciplinary; Physics, Condensed Matter SC Materials Science; Physics GA ZD538 UT WOS:000072696500003 ER PT J AU Pasternak, MP Rozenberg, GK Milner, AP Amanowicz, M Brister, KE Taylor, RD AF Pasternak, MP Rozenberg, GK Milner, AP Amanowicz, M Brister, KE Taylor, RD TI Pressure-induced amorphization of antiferromagnetic FePO4 SO JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS LA English DT Article DE amorphization; high-pressure; antiferromagnets; Mossbauer spectroscopy ID PHASE AB In this paper we describe for the first time an unusual phenomenon occurring in FePO4 (T-N = 25 K), where pressure drives the crystalline low-pressure phase (I) into two, coexisting antiferromagnetic states; one amorphous designated as IIa, the other crystalline (IIb) with an enhanced coordination number. This is unlike the case of berlinite (AlPO4), which completely amorphizes above 15 GPa. Measurements were carried out with Mossbauer Spectroscopy (MS) and X-ray diffraction (XRD) at CHESS, over the pressure range 0-30 GPa. XRD shows that the double transformation starts at similar to 2 GPa reaching saturation at 7 GPa. MS, however, shows that the FePO4-I phase coexists to the highest pressure, indicating possible formation of clusters with sizes undetected by XRD. The abundance of the FePO4 IIa and IIb phases are about equal. Both XRD and the new T-N (= 60 K) value obtained by MS, show that the FePO4-IIa phase is isostructural to CrVO4. No change is observed in the relative abundance of the three phases at P > 7 GPa in which the I-phase constitutes about 10% of the total. The T-N value of the FePO4-II phases increases with increasing pressure: from 50 It at 2.5 GPa to 65 at 25 GPa, The pressure transitions at room temperature are not reversible; after pressure release to ambient value, the FePO4-I is completely restored only after heat treatment in air at T = 700 degrees C. (C) 1998 Elsevier Science B.V. All rights reserved. C1 Tel Aviv Univ, Sch Phys & Astron, IL-69978 Tel Aviv, Israel. Cornell Univ, Wilson Lab, CHESS, Ithaca, NY 14853 USA. Univ Calif Los Alamos Natl Lab, Div Mat Sci & Technol, Los Alamos, NM 87545 USA. RP Pasternak, MP (reprint author), MS K764, Los Alamos, NM 87545 USA. NR 5 TC 3 Z9 3 U1 1 U2 12 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0304-8853 J9 J MAGN MAGN MATER JI J. Magn. Magn. Mater. PD MAR PY 1998 VL 183 IS 1-2 BP 185 EP 187 DI 10.1016/S0304-8853(97)00297-7 PG 3 WC Materials Science, Multidisciplinary; Physics, Condensed Matter SC Materials Science; Physics GA ZD538 UT WOS:000072696500027 ER PT J AU Milewski, JO Lewis, GK Thoma, DJ Keel, GI Nemec, RB Reinert, RA AF Milewski, JO Lewis, GK Thoma, DJ Keel, GI Nemec, RB Reinert, RA TI Directed light fabrication of a solid metal hemisphere using 5-axis powder deposition SO JOURNAL OF MATERIALS PROCESSING TECHNOLOGY LA English DT Article DE directed light fabrication; fully-dense metal deposit; high-powered laser beam AB Directed light fabrication (DLF) is a direct metal deposition process that fuses metal powders, delivered by gas into the focal zone of a high-powered laser beam, to form a fully-dense metal deposit. Computer-based design and numerical controls are used in conjunction with the metal deposition process to guide the formation of 3D parts. This study demonstrates the ability to directly fabricate complex shapes using a 5-axis DLF machine. As an example, the production of a hemispherical shape is described, with the associated fabrication case study, metallographic examination and part characterization. The deposition of fully-dense stainless-steel components is achieved in all orientations, from horizontal to vertical, and dimensional comparisons between the DLF-deposited shape and the original part definition, illustrates that near-net shape tolerance levels are attainable within a 0.1 mm envelope. The single-step production of fully-dense, near-net shaped, 3D metal parts directly from a computer model is achieved without the use of forming dies, tooling or machining. As a result, significant process flexibility over conventional processing capabilities are recognized, with potentially lower productions costs and higher quality components. (C) 1998 Published by Elsevier Science S.A. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. CAD CAM Resources, Rio Rancho, NM 87124 USA. RP Milewski, JO (reprint author), Univ Calif Los Alamos Natl Lab, POB 1663,MS G770, Los Alamos, NM 87545 USA. NR 7 TC 73 Z9 83 U1 5 U2 21 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0924-0136 J9 J MATER PROCESS TECH JI J. Mater. Process. Technol. PD MAR PY 1998 VL 75 IS 1-3 BP 165 EP 172 DI 10.1016/S0924-0136(97)00321-X PG 8 WC Engineering, Industrial; Engineering, Manufacturing; Materials Science, Multidisciplinary SC Engineering; Materials Science GA ZE030 UT WOS:000072750200022 ER PT J AU Adolf, DB Martin, JE Chambers, RS Burchett, SN Guess, TR AF Adolf, DB Martin, JE Chambers, RS Burchett, SN Guess, TR TI Stresses during thermoset cure SO JOURNAL OF MATERIALS RESEARCH LA English DT Review ID SOL-GEL TRANSITION; BRANCHED POLYMERS; VISCOELASTICITY; GELATION; PERCOLATION; EXPONENTS; POINT; EPOXY AB Production problems attributed to excessive stresses generated during the cure of epoxies led us to develop a formalism to predict these stresses. In our first studies, we developed a fundamental understanding of the complex evolution of viscoelasticity as the cure progresses. We then incorporated these results into a proper tensorial constitutive equation that was integrated into our finite element codes and validated using more complicated geometries, thermal histories, and strain profiles. The formalism was then applied to the original production problem to determine cure schedules that would minimize stress generation during cure. During the pursuit of these activities, several interesting and puzzling phenomena were discovered that have stimulated further investigation. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Adolf, DB (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. NR 28 TC 58 Z9 58 U1 1 U2 14 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DR, WARRENDALE, PA 15086 USA SN 0884-2914 J9 J MATER RES JI J. Mater. Res. PD MAR PY 1998 VL 13 IS 3 BP 530 EP 550 DI 10.1557/JMR.1998.0069 PG 21 WC Materials Science, Multidisciplinary SC Materials Science GA ZJ207 UT WOS:000073190200003 ER PT J AU Drews, AR Cline, JP Vanderah, TA Salazar, KV AF Drews, AR Cline, JP Vanderah, TA Salazar, KV TI High-temperature x-ray diffraction studies of a precursor mixture for Pb-substituted Bi-2223 superconducting mires SO JOURNAL OF MATERIALS RESEARCH LA English DT Article ID CRYSTAL-STRUCTURE AB High-temperature x-ray diffraction measurements of a (Bi, Pb)-2223 precursor mixture used to produce high-J(c) superconducting tapes were conducted on silver and ZrO2 substrates. The precursor mixture consisted primarily of 2212, Ca2PbO4, and CuO. Phase evolution was markedly sensitive to oxygen partial pressure: In 10% O-2 growth of the 2223 phase on silver was rapid, proceeded at the expense of the 2212 phase, and was preceded by the disappearance of the Ca2PbO4 phase. When slowly heated on a silver substrate in 7.5% O-2 the 2212 phase melted near 800 degrees C and subsequently recrystallized near 820 degrees C in a highly textured form, but with no detectable 2223 formation. Under similar conditions on a ZrO2 substrate, the mixture exhibited no marked changes in the XRD patterns up to 850 degrees C. The dramatic reactivity on silver was also highly dependent on heating rate; rapid heating in 7.5% O-2 to 825 degrees C did not result in melting of the 2212 phase or appearance of the 2223 phase. In experiments leading to formation of 2223, the c-lattice parameter of the 2212 phase contracted just prior to the onset of formation of 2223. This result is consistent with the formation of an intermediate Pb-doped phase of 2212. A transient amorphous phase appeared briefly at the onset of formation of 2223. No evidence for intergrowth conversion of 2212 to 2223 was observed. C1 Natl Inst Stand & Technol, Mat Sci & Engn Lab, Gaithersburg, MD 20899 USA. Univ Calif Los Alamos Natl Lab, Div Mat Sci & Technol, Los Alamos, NM 87545 USA. RP Drews, AR (reprint author), Natl Inst Stand & Technol, Mat Sci & Engn Lab, Gaithersburg, MD 20899 USA. NR 24 TC 4 Z9 4 U1 0 U2 1 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DR, WARRENDALE, PA 15086 USA SN 0884-2914 J9 J MATER RES JI J. Mater. Res. PD MAR PY 1998 VL 13 IS 3 BP 574 EP 582 DI 10.1557/JMR.1998.0073 PG 9 WC Materials Science, Multidisciplinary SC Materials Science GA ZJ207 UT WOS:000073190200007 ER PT J AU Rawers, J Krabbe, R AF Rawers, J Krabbe, R TI Reproducibility of the synthesis and processing of nanostructured material properties SO JOURNAL OF MATERIALS SYNTHESIS AND PROCESSING LA English DT Article DE nanostructured; mechanical alloying; hot-pressing; reproducibility; iron ID NANOCRYSTALLINE IRON; FE-AL; POWDERS; BEHAVIOR; STABILITY; METALS; ALLOYS; CU AB The reproducibility or variance in the properties of nanostructured milled iron and iron alloy powders and nanostructured compacts was determined and characterized. To date, all too often the characterization of nanostructured materials has been limited to examination of one or two samples, from which it is impossible to determine the reproducibility of the reported values. In this study, multiple attritor millings were made and the variability of the macroscopic and nanostructure characteristics was determined (e.g., particle size, grain size, etc.). From a single milled powder composition, multiple hot-press compacts were made. Statistical analyses were made of the reproducibility of resulting consolidated macroscopic and nanostructured properties, such as density, hardness, grain size, and tensile/compression strength. Mechanical processing of iron powder and mechanical alloying of iron powder with aluminum, carbon, and nitrogen showed that attrition milling reliably reproduced 0.5-kg lots of nanostructured powder. Hot-pressing the milled powder also produced reproducibility nanostructured compacts. There was little or no correlation found between the milled powder properties and the compacted powder properties. Several correlations that are generally valid for large grain materials were found not to hold for nanograin compacts (e.g., between density and hardness). C1 US DOE, Albany Res Ctr, Albany, OR 97321 USA. RP Rawers, J (reprint author), US DOE, Albany Res Ctr, Albany, OR 97321 USA. NR 26 TC 7 Z9 8 U1 0 U2 0 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 MAR PY 1998 VL 6 IS 2 BP 133 EP 146 DI 10.1023/A:1022699503967 PG 14 WC Materials Science, Multidisciplinary SC Materials Science GA 124EW UT WOS:000076169400006 ER PT J AU Rawers, J Slavens, G Du, H AF Rawers, J Slavens, G Du, H TI High-pressure processing and characterization of Fe-high-C/N alloys SO JOURNAL OF MATERIALS SYNTHESIS AND PROCESSING LA English DT Article DE high-pressure melting; iron-carbon-nitrogen steels; microstructure; compression strength ID NITROGEN; IRON AB A new process has been developed that results in (i) enhanced nitrogen addition to ferritic iron-carbon alloys and (ii) melt-casting in a single operation. This new processing technique enables Fe-C alloys to retain high nitrogen interstitial concentrations and to reduce significantly, and possibly eliminate, carbide formation. In this study two commercial-grade, steel alloys were cast under elevated nitrogen pressures, resulting in solid solution (austenite, ferrite, and martensite) high-carbon and high-nitrogen iron alloys that were, within detection limits, carbide- and nitride-free. These alloys were subsequently thermally processed to transform part of the retained austenite to martensite. The microstructure and mechanical properties of the alloys were studied as a function of carbon and nitrogen composition and as a function of thermal processing. The retain high nitrogen concentrations in these cast and processed iron-carbon alloys resulted in a substantial improvement in compression strengths. C1 US DOE, Albany Res Ctr, Adv Mat & Proc Div, Albany, OR 97321 USA. United Technol Res Ctr, E Hartford, CT 06108 USA. RP Rawers, J (reprint author), US DOE, Albany Res Ctr, Adv Mat & Proc Div, Albany, OR 97321 USA. NR 12 TC 5 Z9 5 U1 0 U2 1 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 MAR PY 1998 VL 6 IS 2 BP 147 EP 154 DI 10.1023/A:1022651620806 PG 8 WC Materials Science, Multidisciplinary SC Materials Science GA 124EW UT WOS:000076169400007 ER PT J AU Brigmon, RL Franck, MM Bray, JS Scott, DF Lanclos, KD Fliermans, CB AF Brigmon, RL Franck, MM Bray, JS Scott, DF Lanclos, KD Fliermans, CB TI Direct immunofluorescence and enzyme-linked immunosorbent assays for evaluating organic contaminant degrading bacteria SO JOURNAL OF MICROBIOLOGICAL METHODS LA English DT Article DE bacteria; immunofluorescence; methanotroph; ELISA; trichloroethylene; chlorobenzene ID MONOCLONAL-ANTIBODY; TRICHLOROETHYLENE; GROUNDWATER; ENUMERATION; DEGRADATION; SAMPLES; NUMBER; CELLS; ELISA; SITE AB Immunological procedures were developed to enumerate chlorinated hydrocarbon (CH) degrading bacteria in environmental samples. Polyclonal antibodies (Pabs) were produced by immunizing New Zealand white rabbits against 18 CH-degrading bacteria. These bacteria included methanotrophic and chlorobenzene (CB)-degrading species. An enzyme-linked immunosorbent assay (ELISA) was used to test for cross-reactivity and sensitivity of the Pabs. Direct fluorescent antibodies (DFAs) were developed against selected methanotrophic bacteria isolated from a trichloroethylene (TCE)-contaminated landfill at the Savannah River Site (SRS) and cultures from the American Type Culture Collection (ATCC). Analysis of ELISA results showed some of the Pabs to be group specific while others were species specific. The threshold of sensitivity for the ELISA is 10(5) bacteria cells/ml. Results from the DFA and ELISA techniques for enumeration of methanotrophic bacteria in groundwater were higher but not significantly different (P<0.05) compared to indirect microbiological techniques such as MPN, although the direct enumerations were accomplished in significantly less time. These methods provide important information on in situ microbial community structure and function for bioremediation applications within 1-4 h of sampling. (C) 1998 Elsevier Science B.V. C1 Westinghouse Savannah River Co, Savannah River Technol Ctr, Environm Biotechnol Sect, Aiken, SC 29808 USA. Med Coll Georgia, Dept Biochem & Mol Biol, Augusta, GA 30912 USA. RP Brigmon, RL (reprint author), Westinghouse Savannah River Co, Savannah River Technol Ctr, Environm Biotechnol Sect, Bldg 704-8T, Aiken, SC 29808 USA. EM R03.brigmon@srs.gov NR 29 TC 8 Z9 8 U1 0 U2 6 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0167-7012 J9 J MICROBIOL METH JI J. Microbiol. Methods PD MAR PY 1998 VL 32 IS 1 BP 1 EP 10 DI 10.1016/S0167-7012(97)00092-4 PG 10 WC Biochemical Research Methods; Microbiology SC Biochemistry & Molecular Biology; Microbiology GA ZG793 UT WOS:000073040200001 ER PT J AU Marr, AJ North, SW Sears, TJ Ruslen, L Field, RW AF Marr, AJ North, SW Sears, TJ Ruslen, L Field, RW TI Laser transient absorption spectroscopy of bromomethylene SO JOURNAL OF MOLECULAR SPECTROSCOPY LA English DT Article ID SINGLET-TRIPLET GAP; PHOTOELECTRON-SPECTROSCOPY; EXCITATION SPECTROSCOPY; SUBSTITUTED CARBENES; HCCL; HCBR; HCI; FREQUENCIES; HALOCARBENE; TRANSITION AB We report the observation and assignment of new high-resolution spectra of the (A) over tilde(1) A " <-- (X) over tilde (1)A' transition of bromomethylene, HCBr, obtained by transient laser absorption spectroscopy at near-infrared wavelengths. The 2(0)(1) band of HCBr (nu(0) = 11 957 cm(-1)) and the 2(0)(2) band of DCBr (nu(0) = 12 349 cm(-1)) have been observed for both naturally occurring isotopes of bromine. The c-type rotational branches of the K-a = 0 <-- 1 subbands have been assigned in detail. Other subbands have been partially assigned, but their detailed rotational quantum number analysis has not yet proved possible. Their presence does, however, indicate that the molecule exhibits nonlinear rotational structure in these vibrational levels, in contrast to what was found for the (A) over tilde (1)A " (0, 2, 0) level of HCBr (nu(0) = 12 786 cm(-1)) [B. C. Chang and T. J. Sears, J. Chem. Phys. 105, 2135-2140 (1996)]. Analysis of the rotational structure in the spectra reported here has required a reassessment of certain rotational assignments of that previous work. We now find that the lower singlet state is isolated; there is no evidence of triplet state perturbations. Rotational. constants derived for the ground state of all the naturally occurring isotopomers were used to estimate structural parameters. A barrier to linearity for the (A) over tilde (1) A " state, 13 590 cm(-1) above the zero point level of the ground (X) over tilde (1)A' state, is estimated. (C) 1998 Academic Press. C1 Brookhaven Natl Lab, Dept Chem, Upton, NY 11973 USA. MIT, Dept Chem, Cambridge, MA 02139 USA. RP Sears, TJ (reprint author), Brookhaven Natl Lab, Dept Chem, Upton, NY 11973 USA. RI Sears, Trevor/B-5990-2013; North, Simon/G-5054-2012 OI Sears, Trevor/0000-0002-5559-0154; North, Simon/0000-0002-0795-796X NR 29 TC 36 Z9 36 U1 0 U2 2 PU ACADEMIC PRESS INC PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0022-2852 J9 J MOL SPECTROSC JI J. Mol. Spectrosc. PD MAR PY 1998 VL 188 IS 1 BP 68 EP 77 DI 10.1006/jmsp.1997.7500 PG 10 WC Physics, Atomic, Molecular & Chemical; Spectroscopy SC Physics; Spectroscopy GA YZ914 UT WOS:000072307200008 ER PT J AU Sunwoo, AJ Chow, TS Long, CJ AF Sunwoo, AJ Chow, TS Long, CJ TI Effect of physical vapor deposition on microstructure and properties of uranium 6 wt% niobium alloy SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article AB Uranium-6 wt% niobium alloy samples produced by the physical vapor deposition (PVD) process reveal unique metallurgical and mechanical properties. From two deposition conditions at 580 degrees C with a bias voltage, and at 900 degrees C without bias, the microstructural characterization indicates that the grain distribution morphology of the alloy in each case was primarily determined by the deposition process. Applying the bias voltage of 500 V during the PVD changed the grain morphology from a typical columnar to an equiaxed structure. On the other hand, the substrate temperature controlled the diffusivity of Nb and U and hence the characteristic 'banding' into slightly different compositions observed in such microstructures. Very fine. equiaxed grains of the 580 degrees C specimens are mainly responsible for the highly favorable strength and ductility combination. However, the columnar structure morphology present in the 900 degrees C specimens did not adversely affect the tensile behavior. The 580 degrees C material exhibited superior subzero tensile properties compared to both the 900 degrees C and the wrought-processed materials. The PVD materials that had been specifically heat treated after deposition had room temperature tensile properties comparable to the wrought-processed material. (C) 1998 Elsevier Science B.V. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Sunwoo, AJ (reprint author), Univ Calif Lawrence Livermore Natl Lab, 7000 East Ave, Livermore, CA 94550 USA. NR 10 TC 0 Z9 0 U1 0 U2 4 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3115 J9 J NUCL MATER JI J. Nucl. Mater. PD MAR PY 1998 VL 254 IS 1 BP 65 EP 73 DI 10.1016/S0022-3115(97)00296-1 PG 9 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA ZK952 UT WOS:000073384100009 ER PT J AU Causey, RA Walsh, DS AF Causey, RA Walsh, DS TI Codeposition of deuterium with beryllium SO JOURNAL OF NUCLEAR MATERIALS LA English DT Letter ID HYDROGEN; CARBON AB We have measured the codeposition and/or coimplantation of deuterium with beryllium. Beryllium, sputtered from a target disk was collected on a heated silicon catcher plate where it was simultaneously bombarded by reflected deuterons. Oxygen to beryllium ratios in the layer varied between 0.03 and 0.13. Deuterium to beryllium ratios dropped from 0.15 at 373 K to 0.02 at 573 K. (C) 1998 Elsevier Science B.V. C1 Sandia Natl Labs, Livermore, CA 94550 USA. Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Causey, RA (reprint author), Sandia Natl Labs, Livermore, CA 94550 USA. NR 18 TC 40 Z9 40 U1 0 U2 5 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3115 J9 J NUCL MATER JI J. Nucl. Mater. PD MAR PY 1998 VL 254 IS 1 BP 84 EP 86 DI 10.1016/S0022-3115(97)00344-9 PG 3 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA ZK952 UT WOS:000073384100012 ER PT J AU Miriyala, N Liaw, PK McHargue, CJ Snead, LL AF Miriyala, N Liaw, PK McHargue, CJ Snead, LL TI The mechanical behavior of a Nicalon/SiC composite at room temperature and 1000 degrees C SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT 5th International Symposium on Fabrication and Properties of Ceramics for Fusion Energy and Other High Radiation Environments, at the 99th Annual Meeting of the ACS CY MAY 05-07, 1997 CL CINCINNATI, OHIO SP Amer Ceram Soc, Nucl & Environm Technol Div ID CERAMIC-MATRIX COMPOSITES; SIC/SIC COMPOSITES; STRENGTH; FATIGUE AB The effects of fabric orientation on the mechanical behavior of a Nicalon/SiC composite were investigated by performing flexure tests at room temperature in air, and at 1000 degrees C in an argon environment. The specimen configurations were designated as edge-on and transverse, depending on whether the load was applied parallel or normal to the fabric plies, respectively. The monotonic and fatigue behavior of the material was not noticeably affected by fabric orientation, at both room and elevated temperatures. The interlaminar pores in the material appeared to have acted as stress concentration sites. The cracks initiated from these sites linked up the interlaminar pores, resulting in specimen severance under monotonic and fatigue loadings, in both edge-on and transverse orientations. (C) 1998 Elsevier Science B.V. C1 Oak Ridge Natl Lab, Div Met & Ceram, Oak Ridge, TN 37831 USA. Univ Tennessee, Dept Mat Sci & Engn, Knoxville, TN 37996 USA. RP Snead, LL (reprint author), Oak Ridge Natl Lab, Div Met & Ceram, POB 2008, Oak Ridge, TN 37831 USA. NR 31 TC 9 Z9 13 U1 0 U2 7 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3115 J9 J NUCL MATER JI J. Nucl. Mater. PD MAR PY 1998 VL 253 BP 1 EP 9 DI 10.1016/S0022-3115(97)00341-3 PG 9 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA ZR723 UT WOS:000074007300002 ER PT J AU Snead, LL Osborne, MC Lowden, RA Strizak, J Shinavski, RJ More, KL Eatherly, WS Bailey, J Williams, AM AF Snead, LL Osborne, MC Lowden, RA Strizak, J Shinavski, RJ More, KL Eatherly, WS Bailey, J Williams, AM TI Low dose irradiation performance of SiC interphase SiC/SiC composites SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT 5th International Symposium on Fabrication and Properties of Ceramics for Fusion Energy and Other High Radiation Environments, at the 99th Annual Meeting of the ACS CY MAY 05-07, 1997 CL CINCINNATI, OH SP Amer Ceram Soc, Nucl & Environm Technol Div ID SILICON-CARBIDE FIBER; NEUTRON-IRRADIATION; RADIATION; STRENGTH AB Reduced oxygen Hi-Nicalon(TM) fiber reinforced composite SiC materials were densified with a chemically vapor infiltrated (CVI) silicon carbide (SiC) matrix and interphases of either 'porous' SiC or multilayer SiC and irradiated to a neutron fluence of 1.1 x 10(25) n m(-2) (E > 0.1 MeV) in the temperature range of 260 to 1060 degrees C. The unirradiated properties of these composites are superior to previously studied ceramic grade Nicalon fiber reinforced/carbon interphase materials. Negligible reduction in the macroscopic matrix microcracking stress was observed after irradiation for the multilayer SiC interphase material and a slight reduction in matrix microcracking stress was observed for the composite with porous SiC interphase. The reduction in strength for the porous SiC interfacial material is greatest for the highest irradiation temperature, The ultimate fracture stress (in four point bending) following irradiation For the multilayer SiC and porous SiC interphase materials was reduced by 15% and 30%, respectively, which is an improvement over the 40% reduction suffered by irradiated ceramic grade Nicalon fiber materials fabricated in a similar fashion, though with a carbon interphase. The degradation of the mechanical properties of these composites is analyzed by comparison with the irradiation behavior of bare Hi-Nicalon fiber and Morton chemically vapor deposited (CVD) SIG. It is concluded that the degradation of these composites, as with the previous generation ceramic grade Nicalon fiber materials, is dominated by interfacial effects, though the overall degradation ol-fiber and hence composite is reduced for the newer low-oxygen fiber. (C) 1998 Elsevier Science B.V. C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. Rensselaer Polytech Inst, Troy, NY 12180 USA. Hypertherm Inc, Huntington Beach, CA 92648 USA. RP Snead, LL (reprint author), Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. EM z2n@ornl.gov RI More, Karren/A-8097-2016 OI More, Karren/0000-0001-5223-9097 NR 34 TC 59 Z9 62 U1 0 U2 14 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3115 EI 1873-4820 J9 J NUCL MATER JI J. Nucl. Mater. PD MAR PY 1998 VL 253 BP 20 EP 30 DI 10.1016/S0022-3115(97)00321-8 PG 11 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA ZR723 UT WOS:000074007300004 ER PT J AU Hasegawa, A Saito, M Abe, K Jones, RH AF Hasegawa, A Saito, M Abe, K Jones, RH TI Helium implantation effects on mechanical properties of SiCf/SiC composites SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT 5th International Symposium on Fabrication and Properties of Ceramics for Fusion Energy and Other High Radiation Environments, at the 99th Annual Meeting of the ACS CY MAY 05-07, 1997 CL CINCINNATI, OH SP Amer Ceram Soc, Nucl & Environm Technol Div ID FIBERS AB Helium effects on mechanical properties of SiC/SiC composites were studied to apply the composites on structural materials of a fusion reactor. Two types of 2D-SiC/SiC composites were examined in this work. Helium was implanted using 36 MeV alpha particles with an energy degrader system to obtain a uniform helium depth distribution in the specimen. The implantation temperature was 400-800 degrees C and the helium concentration after implantation was about 150-170 appm. Three-point bending test was carried out at room temperature. Results of bending test showed that a small decrease of bend strength was observed in the composite which had the higher bend strength before implantation. Helium implantation effect was not clearly observed in the lower bend strength composite. SEM observation results on the fracture surface gave no evidence for fiber coating failure. The decrease of bend strength after helium implantation may be attributed to a degradation of mechanical properties of the fibers by implanted helium. (C) 1998 Elsevier Science B.V. C1 Tohoku Univ, Dept Quantum Sci & Energy Engn, Aoba Ku, Sendai, Miyagi 98077, Japan. Pacific NW Natl Lab, Richland, WA 99352 USA. RP Hasegawa, A (reprint author), Tohoku Univ, Dept Quantum Sci & Energy Engn, Aoba Ku, Sendai, Miyagi 98077, Japan. EM akira.hasegawa@qse.tohoku.ac.jp NR 12 TC 9 Z9 10 U1 0 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3115 EI 1873-4820 J9 J NUCL MATER JI J. Nucl. Mater. PD MAR PY 1998 VL 253 BP 31 EP 35 DI 10.1016/S0022-3115(97)00342-5 PG 5 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA ZR723 UT WOS:000074007300005 ER PT J AU Lewinsohn, CA Hamilton, ML Youngblood, GE Jones, RH Garner, FA Hecht, SL Kohyama, A AF Lewinsohn, CA Hamilton, ML Youngblood, GE Jones, RH Garner, FA Hecht, SL Kohyama, A TI Irradiation-enhanced creep in SiC: data summary and planned experiments SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT 5th International Symposium on Fabrication and Properties of Ceramics for Fusion Energy and Other High Radiation Environments, at the 99th Annual Meeting of the ACS CY MAY 05-07, 1997 CL CINCINNATI, OHIO SP Amer Ceram Soc, Nucl & Environm Technol Div ID HIGH-TEMPERATURE CREEP; SILICON-CARBIDE; FUSION APPLICATIONS; MECHANISMS; KINETICS; COMPOSITES; FIBER AB Silicon carbide composites are under consideration for structural applications in proposed magnetic fusion energy systems. The limited data available suggest that creep of silicon carbide, like that of metals, is enhanced in a neutron environment. Existing irradiation-creep data on silicon carbide are reviewed and the ramifications of these data are discussed. Two experimental approaches to determine the irradiation creep of a silicon carbide composite are described. One of these utilizes a flat, reduced gage section specimen loaded in tension and the other utilizes a pressurized cylinder. (C) 1998 Elsevier Science B.V. C1 Pacific NW Natl Lab, Richland, WA 99352 USA. DE&S Hanford, Richland, WA USA. Kyoto Univ, Kyoto 606, Japan. RP Lewinsohn, CA (reprint author), Pacific NW Natl Lab, Richland, WA 99352 USA. EM ca_lewinsohn@pnl.gov NR 21 TC 8 Z9 8 U1 1 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3115 J9 J NUCL MATER JI J. Nucl. Mater. PD MAR PY 1998 VL 253 BP 36 EP 46 DI 10.1016/S0022-3115(97)00303-6 PG 11 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA ZR723 UT WOS:000074007300006 ER PT J AU Devanathan, R de la Rubia, TD Weber, WJ AF Devanathan, R de la Rubia, TD Weber, WJ TI Displacement threshold energies in beta-SiC SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT 5th International Symposium on Fabrication and Properties of Ceramics for Fusion Energy and Other High Radiation Environments, at the 99th Annual Meeting of the ACS CY MAY 05-07, 1997 CL CINCINNATI, OH SP Amer Ceram Soc, Nucl & Environm Technol Div ID 6H SILICON-CARBIDE; MOLECULAR-DYNAMICS; SURFACES; DEFECTS; POTENTIALS AB We have calculated the displacement threshold energies (E-d) for C and Si primary knock-on atoms (PKA) in beta-SIC using molecular dynamic simulations. The interactions between atoms were modeled using a modified form of the Tersoff potential in combination with a realistic repulsive potential obtained from density-functional theory calculations. The simulation cell was cubic, contained 8000 atoms and had periodic boundaries. The temperature of the simulation was about 150 K. Our results indicate strong anisotropy in the E-d values for both Si and C PKA. The displacement threshold for Si varies from about 36 eV along [001] to 113 eV along [111], while E-d for C varies from 28 eV along [111] to 71 eV along [111]. These results are in good agreement with experimental observations. (C) 1998 Elsevier Science B.V. C1 Pacific NW Natl Lab, Richland, WA 99352 USA. Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Devanathan, R (reprint author), Pacific NW Natl Lab, POB 999,MS K1-96, Richland, WA 99352 USA. EM ran.devanathan@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 27 TC 90 Z9 91 U1 1 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 MAR PY 1998 VL 253 BP 47 EP 52 DI 10.1016/S0022-3115(97)00304-8 PG 6 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA ZR723 UT WOS:000074007300007 ER PT J AU Weber, WJ Yu, N Wang, LM AF Weber, WJ Yu, N Wang, LM TI Irradiation-induced amorphization in beta-SiC SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT 5th International Symposium on Fabrication and Properties of Ceramics for Fusion Energy and Other High Radiation Environments, at the 99th Annual Meeting of the ACS CY MAY 05-07, 1997 CL CINCINNATI, OHIO SP Amer Ceram Soc, Nucl & Environm Technol Div ID IMPLANTED IONS; TRANSITION AB Single-crystal (001) beta-SIC (3C) films have been irradiated with 360 keV Ar2+ ions at 175, 310 and 375 K and the damage accumulation after each incremental fluence has been measured insitu by Rutherford backscattering spectroscopy in channeling geometry (RBS/C) along the [011] direction using the dual beam facilities within the Ion Beam Materials Laboratory at Los Alamos National Laboratory. The relative rate of disordering along [011] decreases with increasing temperature. The critical dose for the relative disorder to reach the random level along [011] is 0.35 dpa (17.5 eV/atom), 0.44 dpa (22.0 eV/atom) and 0.61 dpa (30.5 eV/atom) at 175, 310 and 375 K, respectively. The sigmoidal increase in relative disorder with dose is consistent with defect accumulation processes. Although RBS/C along [011] indicates a fully random layer at the highest dose for each temperature, ex situ RBS/C and XTEM along [001] indicate some residual crystallinity remains near the surface and the end of range. (C) 1998 Elsevier Science B.V. C1 Pacific NW Natl Lab, Richland, WA 99352 USA. Texas Instruments Inc, Dallas, TX 75243 USA. Univ New Mexico, Dept Earth & Planetary Sci, Albuquerque, NM 87131 USA. RP Weber, WJ (reprint author), Pacific NW Natl Lab, POB 999,MSIN K2-44, Richland, WA 99352 USA. RI Weber, William/A-4177-2008 OI Weber, William/0000-0002-9017-7365 NR 19 TC 75 Z9 75 U1 1 U2 18 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 MAR PY 1998 VL 253 BP 53 EP 59 DI 10.1016/S0022-3115(97)00305-X PG 7 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA ZR723 UT WOS:000074007300008 ER PT J AU Henager, CH Youngblood, GE Senor, DJ Newsome, GA Woods, JJ AF Henager, CH Youngblood, GE Senor, DJ Newsome, GA Woods, JJ TI Dimensional stability and tensile strength of irradiated Nicalon-CG and Hi-Nicalon fibers SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT 5th International Symposium on Fabrication and Properties of Ceramics for Fusion Energy and Other High Radiation Environments, at the 99th Annual Meeting of the ACS CY MAY 05-07, 1997 CL CINCINNATI, OHIO SP Amer Ceram Soc, Nucl & Environm Technol Div ID SILICON-CARBIDE; WEIBULL DISTRIBUTION; COMPOSITES; FUSION AB Nicalon-CG and Hi-Nicalon fibers were characterized by measuring their density and tensile strength in the unirradiated, thermal annealed, and irradiated conditions. The results indicate the fibers that perform best after irradiation to 43 dDa SiC at 1000 degrees C are those Chat approach stoichiometric and crystalline SiC. Hi-Nicalon fiber exhibited less than 1% densification, accompanied by a slight increase in tensile strength after irradiation. Nicalon-CG, in contrast, was significantly weakened in the annealed and irradiated conditions. In addition, Nicalon-CG exhibited substantial irradiation-induced shrinkage. Loss of fiber tensile strength after irradiation is shown to reduce the flexural strength of irradiated composites while fiber shrinkage, and resultant debonding from the matrix, are linked to a reduced composite elastic modulus. (C) 1998 Elsevier Science B.V. C1 Pacific NW Natl Lab, Richland, WA 99352 USA. Lockheed Martin, Schenectady, NY 12301 USA. RP Henager, CH (reprint author), Pacific NW Natl Lab, POB 999, Richland, WA 99352 USA. OI Henager, Chuck/0000-0002-8600-6803 NR 16 TC 8 Z9 8 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3115 J9 J NUCL MATER JI J. Nucl. Mater. PD MAR PY 1998 VL 253 BP 60 EP 66 DI 10.1016/S0022-3115(97)00322-X PG 7 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA ZR723 UT WOS:000074007300009 ER PT J AU Osborne, MC Hubbard, CR Snead, LL Steiner, D AF Osborne, MC Hubbard, CR Snead, LL Steiner, D TI Neutron irradiation effects on the density, tensile properties and microstructural changes in Hi-Nicalon (TM) and Sylramic (TM) SiC fibers SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT 5th International Symposium on Fabrication and Properties of Ceramics for Fusion Energy and Other High Radiation Environments, at the 99th Annual Meeting of the ACS CY MAY 05-07, 1997 CL CINCINNATI, OH SP Amer Ceram Soc, Nucl & Environm Technol Div ID SILICON-CARBIDE; REINFORCED CERAMICS; FUSION-REACTORS; COMPOSITES; RADIATION; FRACTURE; BEHAVIOR; STRENGTH AB Tensile results are presented for ceramic grade (cg) Nicalon(TM), Hi-Nicalon(TM) and Sylramic(TM) SiC fibers which have all been neutron irradiated in the high flux isotope reactor (HFIR) at damage levels of 0,1, 0.5, 2 and 5 dpa. Single fibers were tensile tested and the results were analyzed using Weibull statistics. Fiber axial displacements were measured with a laser micrometer which allowed for the determination of the tensile moduli. Density changes were measured with a gradient column. Transmission electron microscopy (TEM) was performed to assess microstructural damage and X-ray diffraction (XRD) was used to measure uniform strain, degree of crystallinity, average coherence length and root-mean-square microstrain. The physical and tensile results indicate that cg Nicalon(TM) and Hi-Nicalon(TM) are unstable in a neutron field. Both fiber types densify by 3-5% which would be detrimental to a composite's matrix cracking st ess due to weakening or debonding of the interface. The Sylramic(TM) swells which is similar behavior to the monolithic SiC, The failure strength of the Sylramic(TM) drops by 50% after an irradiation temperature of 500 degrees C which would have little effect on the matrix cracking condition of a composite. The Sylramic(TM) fiber strength decrease would significantly reduce the ultimate composite strength but the composite strength would remain above the matrix cracking strength such that the fibers may still potentially be viable for fusion applications. (C) 1998 Elsevier Science B.V. C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. Rensselaer Polytech Inst, Troy, NY 12180 USA. RP Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. EM z2n@ornl.gov NR 41 TC 18 Z9 19 U1 0 U2 10 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3115 EI 1873-4820 J9 J NUCL MATER JI J. Nucl. Mater. PD MAR PY 1998 VL 253 BP 67 EP 77 DI 10.1016/S0022-3115(97)00306-1 PG 11 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA ZR723 UT WOS:000074007300010 ER PT J AU Devanathan, R Sickafus, KE Weber, WJ Nastasi, M AF Devanathan, R Sickafus, KE Weber, WJ Nastasi, M TI Effects of ionizing radiation in ceramics SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT 5th International Symposium on Fabrication and Properties of Ceramics for Fusion Energy and Other High Radiation Environments, at the 99th Annual Meeting of the ACS CY MAY 05-07, 1997 CL CINCINNATI, OHIO SP Amer Ceram Soc, Nucl & Environm Technol Div ID ISOLATED AMORPHOUS REGIONS; IRRADIATION SPECTRUM; ION; DIFFUSION; MICROSTRUCTURE; INSULATORS; AL2O3; MGO AB The evolution of radiation damage in ceramics under highly ionizing conditions has been examined by irradiating a number of oxides with high-energy heavy ions and electrons simultaneously. alpha-Al2O3, MgTiO3, FeTiO3 and Ca2La8(SiO4)(6)O-2 were irradiated with 1 MeV Kr+ or 1.5 MeV Xe+ and 1 MeV electrons. The irradiations were performed in a high-voltage electron microscope interfaced to an ion accelerator that enabled the in situ observation of the structural changes. The results indicate that simultaneous electron irradiation can retard or prevent amorphization by heavy ions. Comparison with similar experiments in metals suggests that highly ionizing radiation can anneal damage to the crystal lattice in ceramics by enhancing the mobility of point defects. (C) 1998 Elsevier Science B.V. C1 Pacific NW Natl Lab, Richland, WA 99352 USA. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Devanathan, R (reprint author), Pacific NW Natl 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 29 TC 19 Z9 19 U1 1 U2 17 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 MAR PY 1998 VL 253 BP 113 EP 119 DI 10.1016/S0022-3115(97)00307-3 PG 7 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA ZR723 UT WOS:000074007300014 ER PT J AU Zinkle, SJ Pells, GP AF Zinkle, SJ Pells, GP TI Microstructure of Al2O3 and MgAl2O4 irradiated at low temperatures SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT 5th International Symposium on Fabrication and Properties of Ceramics for Fusion Energy and Other High Radiation Environments, at the 99th Annual Meeting of the ACS CY MAY 05-07, 1997 CL CINCINNATI, OH SP Amer Ceram Soc, Nucl & Environm Technol Div ID MAGNESIUM ALUMINATE SPINEL; ELECTRON-IRRADIATION; ION-IRRADIATION; RADIATION-RESISTANCE; SAPPHIRE ALPHA-AL2O3; CERAMIC INSULATORS; DEFECT CLUSTERS; SINGLE-CRYSTALS; DAMAGE RESPONSE; SILICON-CARBIDE AB Polycrystalline specimens of aluminum oxide (99.9% purity) and stoichiometric magnesium aluminate spinel (MgAl2O4) were irradiated with 4 MeV Ar+ ions at 200 and 300 K to doses of 0.1 to 10 displacements per atom (dpa). Volumetric swelling was determined from step-height and lattice parameter measurements. The step-height swelling increased with decreasing irradiation temperature, with values of similar to 4.5% and similar to 0.8% in Al2O3 and MgAl2O4, after similar to 10 and 5 dpa at 200 K, respectively. Faulted interstitial dislocation loops lying on {111} planes were observed in spinel irradiated at 200 and 300 K, indicating the presence of significant interstitial mobility at both temperatures. Dislocation loops and network dislocations were observed in alumina following irradiation at 300 K, but resolvable defect clusters did not form at 200 K. Amorphization was not observed in any of the specimens. The critical temperature for amorphization is predicted to be slightly below 200 K for alumina irradiated at similar to 10(-4) dpa/s. Due to the higher defect mobility in spinel compared to alumina, the critical temperature for amorphization in spinel is expected to he significantly lower than that of alumina. (C) 1998 Elsevier Science B.V. C1 Oak Ridge Natl Lab, Div Met & Ceram, Oak Ridge, TN 37831 USA. AEA Technol, Harwell Lab, Mat Chem Grp, Didcot OX11 0RA, Oxon, England. RP Zinkle, SJ (reprint author), 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 72 TC 35 Z9 35 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 MAR PY 1998 VL 253 BP 120 EP 132 DI 10.1016/S0022-3115(97)00323-1 PG 13 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA ZR723 UT WOS:000074007300015 ER PT J AU Hazelton, C Rice, J Snead, LL Zinkle, SJ AF Hazelton, C Rice, J Snead, LL Zinkle, SJ TI Effect of neutron radiation on the dielectric, mechanical and thermal properties of ceramics for rf transmission windows SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT 5th International Symposium on Fabrication and Properties of Ceramics for Fusion Energy and Other High Radiation Environments, at the 99th Annual Meeting of the ACS CY MAY 05-07, 1997 CL CINCINNATI, OHIO SP Amer Ceram Soc, Nucl & Environm Technol Div ID IRRADIATION; AL2O3 AB The behavior of electrically insulating ceramics was investigated before and after exposure to neutron radiation. Mechanical, thermal and dielectric specimens were studied after exposure to a fast neutron dose of 0.1 displacements per atom (dpa) at Oak Ridge National Laboratory (ORNL). Four materials were compared to alumina: polycrystalline spinel, aluminum nitride, sialon and silicon nitride. Mechanical bend tests were performed before and after irradiation. Thermal diffusivity was measured using a room temperature laser flash technique. Dielectric loss factor was measured at 105 MHz with a special high resolution resonance cavity. The materials exhibited a significant degradation of thermal diffusivity and an increase in dielectric loss tangent, The flexural strength and physical dimensions were not significantly affected by the 0.1 dpa level of neutron radiation. The aluminum nitride and S silicon nitride showed superior rf window performance over the sialon and the alumina. The results are compared to radiation studies on similar materials. (C) 1998 Elsevier Science B.V. C1 Composite Technol Dev Inc, Lafayette, CO 80026 USA. Oak Ridge Natl Lab, Div Met & Ceram, Oak Ridge, TN 37831 USA. RP Hazelton, C (reprint author), Composite Technol Dev Inc, 1505 Coal Creek Dr, Lafayette, CO 80026 USA. OI Zinkle, Steven/0000-0003-2890-6915 NR 22 TC 17 Z9 17 U1 0 U2 7 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3115 J9 J NUCL MATER JI J. Nucl. Mater. PD MAR PY 1998 VL 253 BP 190 EP 195 DI 10.1016/S0022-3115(97)00333-4 PG 6 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA ZR723 UT WOS:000074007300023 ER PT J AU Roberts, JE Hu, DN Wishart, JF AF Roberts, JE Hu, DN Wishart, JF TI Pulse radiolysis studies of melatonin and chloromelatonin (vol 42, pg 125, 1998) SO JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY B-BIOLOGY LA English DT Correction C1 Fordham Univ, New York, NY 10023 USA. New York Eye & Ear Infirm, Tissue Culture Ctr, New York, NY 10003 USA. Brookhaven Natl Lab, Dept Chem, Upton, NY 11973 USA. RP Roberts, JE (reprint author), Fordham Univ, 113 W 60th St, New York, NY 10023 USA. NR 1 TC 0 Z9 0 U1 0 U2 0 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 1011-1344 J9 J PHOTOCH PHOTOBIO B JI J. Photochem. Photobiol. B-Biol. PD MAR PY 1998 VL 42 IS 3 BP 246 EP 246 DI 10.1016/S1011-1344(98)00084-0 PG 1 WC Biochemistry & Molecular Biology; Biophysics SC Biochemistry & Molecular Biology; Biophysics GA ZK367 UT WOS:000073313300012 ER PT J AU Idemoto, Y Richardson, JW Koura, N Kohara, S Loong, CK AF Idemoto, Y Richardson, JW Koura, N Kohara, S Loong, CK TI Crystal structure of (LixK1-x)(2)CO3 (x = 0, 0.43, 0.5, 0.62, 1) by neutron powder diffraction analysis SO JOURNAL OF PHYSICS AND CHEMISTRY OF SOLIDS LA English DT Article DE crystal structure; inorganic compound; neutron scattering ID MOLECULAR-DYNAMICS SIMULATION; ALKALI CARBONATES; MD-SIMULATION; MOLTEN AB The crystal structures of (LixKl-x)(2)CO3(x = 0, 0.43, 0.5, 0.62, 1) were determined by neutron powder diffraction at room temperature. These samples were obtained by a melt and quench process. (LixKl-x)(2)CO3 (x = 0, 0.5, 1) formed as single phases and (LixKl-x)(2)CO3(x = 0.43, 0.62) contained two phases at room temperature. In the Rietveld refinements, the improvement from Li-7 enrichment is due to the lower absorption coefficient of Li-7 than of Li-6. A final weighted R-factor of 4.54% was obtained for the refinement of 2373 reflections by the Rietveld method from a (Li0.5K0.5)(2)CO3 synthesized using (Li2CO3)-Li-7 and K2CO3 (99.9% pure). Slight distortion of the CO32- units in the monoclinic cell was observed; the O(1)-C-O(2) angle and C-O(3) length are larger than those for the other C-O bonds and O-C-O angles. These local structure characteristics can be explained by the difference in the ionic size of Li+ and K+ and the different electrostatic interactions between the cations and CO32- units. (C) 1997 Elsevier Science Ltd. C1 Sci Univ Tokyo, Fac Sci & Technol, Dept Ind Chem, Chiba 278, Japan. Argonne Natl Lab, Argonne, IL 60439 USA. RP Idemoto, Y (reprint author), Sci Univ Tokyo, Fac Sci & Technol, Dept Ind Chem, 2641 Yamazaki, Chiba 278, Japan. NR 17 TC 42 Z9 44 U1 0 U2 12 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0022-3697 J9 J PHYS CHEM SOLIDS JI J. Phys. Chem. Solids PD MAR PY 1998 VL 59 IS 3 BP 363 EP 376 DI 10.1016/S0022-3697(97)00209-6 PG 14 WC Chemistry, Multidisciplinary; Physics, Condensed Matter SC Chemistry; Physics GA YR362 UT WOS:000071487800010 ER PT J AU Smith, AB AF Smith, AB TI Fast neutrons incident on titanium SO JOURNAL OF PHYSICS G-NUCLEAR AND PARTICLE PHYSICS LA English DT Article ID OPTICAL-MODEL; ELASTIC-SCATTERING; ENERGY-DEPENDENCE; CROSS-SECTIONS; NUCLEI; STATE AB Differential neutron elastic-scattering cross sections of elemental titanium were measured from 4.5 to 10.0 MeV in incident-energy increments of approximate to 0.5 MeV and at forty or more scattering angles distributed between approximate to 17 degrees and 160 degrees degrees. Concurrently, differential neutron inelastic-scattering cross sections were measured for observed excitations of 975 +/- 34, 1497 +/- 33, 2322 +/- 58, 3252 +/- 43, 3700 +/- 93, 4317 +/- 75 and 4795 +/- approximate to 100 keV. All of the observed inelastic neutron groups were composites of contributions from several isotopes and/or levels. The experimental results were used to develop energy-average optical, statistical and coupled-channels models. C1 Argonne Natl Lab, Argonne, IL 60439 USA. Univ Arizona, Tucson, AZ USA. RP Argonne Natl Lab, 9700 S Cass Ave, Argonne, IL 60439 USA. NR 90 TC 3 Z9 3 U1 0 U2 0 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0954-3899 EI 1361-6471 J9 J PHYS G NUCL PARTIC JI J. Phys. G-Nucl. Part. Phys. PD MAR PY 1998 VL 24 IS 3 BP 637 EP 651 DI 10.1088/0954-3899/24/3/014 PG 15 WC Physics, Nuclear; Physics, Particles & Fields SC Physics GA ZE467 UT WOS:000072795800014 ER PT J AU Webb, SW AF Webb, SW TI Gas-phase diffusion in porous media - Evaluation of an advective-dispersive formulation and the dusty-gas model for binary mixtures SO JOURNAL OF POROUS MEDIA LA English DT Article ID TRANSPORT; FLOW AB Two models for combined gas-phase diffusion and advection in porous media, the Advective-Dispersive Model (ADM) and the Dusty-Gas Model (DGM), are commonly used. The ADM is based on a simple linear addition of advection calculated by Darcy's law and ordinary diffusion using Fick's law with a porosity-tortuosity-gas saturation multiplier to account for the porous medium. Another approach for gas-phase transport in porous media is the Dusty-Gas Model (DGM). This model applies the kinetic theory of gases to the gaseous components and the porous media (or "dust") to develop an approach for combined transport due to diffusion and advection that includes porous medium effects. The objective of this paper is to evaluate these two approaches by comparison to Graham's laws and to isothermal experimental data for He-Ar gas diffusion in a low-permeability graphite. This evaluation shows that the ADM while intuitively appealing, violates Graham's laws and does not compare well to the experimental data. In contrast, the DGM is based on Graham's laws and shows excellent agreement with the data. The two models are further compared for a hypothetical linear air-water porous media heat pipe, involving heat, advection, capillary transport, and diffusion under nonisothermal unsaturated conditions. If diffusion is an important transport mechanism, the DGM is preferable to the ADM because the ADM may give incorrect trends and/or misleading results. C1 Sandia Natl Labs, Dept Geohydrol, Albuquerque, NM 87185 USA. RP Webb, SW (reprint author), Sandia Natl Labs, Dept Geohydrol, 6115-MS-1324, Albuquerque, NM 87185 USA. NR 29 TC 25 Z9 25 U1 3 U2 8 PU BEGELL HOUSE INC PI NEW YORK PA 79 MADISON AVE, SUITE 1205, NEW YORK, NY 10016-7892 USA SN 1091-028X J9 J POROUS MEDIA JI J. Porous Media PD MAR PY 1998 VL 1 IS 2 BP 187 EP 199 PG 13 WC Thermodynamics; Engineering, Mechanical; Mechanics SC Thermodynamics; Engineering; Mechanics GA 154PC UT WOS:000077896600007 ER PT J AU Navratil, JD Todd, TA Van Vliet, JA AF Navratil, JD Todd, TA Van Vliet, JA TI Chemical separation activities in environmental management at the Idaho National Engineering and Environmental Laboratory SO JOURNAL OF RADIOANALYTICAL AND NUCLEAR CHEMISTRY LA English DT Article; Proceedings Paper CT 7th International Conference on Separation of Ionic Solutes CY MAY 18-23, 1997 CL PIESTANY SPA, SLOVAKIA SP Comenius Univ, Fac Sci, Bratislava, Fdn CURIE, Bratislava, Slovak Acad Sci, Slovak Chem Soc, EMVI 2000 s r o Brno, Czech Republic, HUMA LAB APEKO s r o, Kosice AB Besides a brief review of the INEEL, examples of chemical separation activities in environmental management are presented in this paper. Under development at the INEEL are separation technologies for the treatment of radioactive wastes, including highly radioactive liquid wastes, solid calcined wastes and mixed wastes, as well as contaminated groundwater and soils. An overview of these technologies, specific applications of the technologies, and the benefits from their use are discussed. C1 Lockheed Martin Idaho Technol Co, Idaho Falls, ID 83415 USA. RP Navratil, JD (reprint author), Lockheed Martin Idaho Technol Co, POB 1625, Idaho Falls, ID 83415 USA. RI Todd, Terry /O-4930-2016 OI Todd, Terry /0000-0003-1324-6950 NR 16 TC 0 Z9 0 U1 0 U2 1 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0236-5731 J9 J RADIOANAL NUCL CH JI J. Radioanal. Nucl. Chem. PD MAR PY 1998 VL 229 IS 1-2 BP 99 EP 103 DI 10.1007/BF02389455 PG 5 WC Chemistry, Analytical; Chemistry, Inorganic & Nuclear; Nuclear Science & Technology SC Chemistry; Nuclear Science & Technology GA ZF336 UT WOS:000072887300019 ER PT J AU Pfanstiel, SE Hofstetter, KJ DeVol, TA AF Pfanstiel, SE Hofstetter, KJ DeVol, TA TI Comparison of four types of gamma- and X-ray detectors for environmental applications in the 10-450 keV energy range (vol 223, pg 89, 1997) SO JOURNAL OF RADIOANALYTICAL AND NUCLEAR CHEMISTRY LA English DT Correction C1 Clemson Univ, Dept Environm Syst Engn, Clemson, SC 29634 USA. Westinghouse Savannah River Co, Savannah River Technol Ctr, Aiken, SC 29808 USA. RP Pfanstiel, SE (reprint author), Clemson Univ, Dept Environm Syst Engn, Clemson, SC 29634 USA. NR 1 TC 0 Z9 0 U1 0 U2 1 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0236-5731 J9 J RADIOANAL NUCL CH JI J. Radioanal. Nucl. Chem. PD MAR PY 1998 VL 229 IS 1-2 BP 216 EP 216 DI 10.1007/BF02389481 PG 1 WC Chemistry, Analytical; Chemistry, Inorganic & Nuclear; Nuclear Science & Technology SC Chemistry; Nuclear Science & Technology GA ZF336 UT WOS:000072887300044 ER PT J AU Davenport, DW Breshears, DD Wilcox, BP Allen, CD AF Davenport, DW Breshears, DD Wilcox, BP Allen, CD TI Viewpoint: Sustainability of pinon-juniper ecosystems - a unifying perspective of soil erosion thresholds SO JOURNAL OF RANGE MANAGEMENT LA English DT Article DE pinyon; pinon; juniper; soil erosion; threshold; site erodibility; percolation theory; catastrophe theory; scale dependence; runoff; grazing; drought; understory; canopy; intercanopy ID NEW-MEXICO; SEDIMENT PRODUCTION; CATASTROPHE-THEORY; SPATIAL PATTERN; RANGE CONDITION; WOODLANDS; WATER; INFILTRATION; VEGETATION; DYNAMICS AB Many pinon-juniper ecosystems in the western U.S. are subject to accelerated erosion while others are undergoing little or no erosion. Controversy has developed over whether invading or encroaching pinon and juniper species are inherently harmful to rangeland ecosystems. We developed a conceptual model of soil erosion in pinon-juniper ecosystems that is consistent with both sides of the controversy and suggests that the diverse perspectives on this issue arise from threshold effects operating under very different site conditions. Soil erosion rate can be viewed as a function of (1) site erosion potential (SEP), determined by climate, geomorphology and soil erodibility; and (2) ground cover. Site erosion potential and cover act synergistically to determine soil erosion rates, as evident even from simple USLE predictions of erosion. In pinion-juniper ecosystems with high SEP, the erosion rate is highly sensitive to ground cover and can cross a threshold so that erosion increases dramatically in response to a small decrease in cover. The sensitivity of erosion rate to SEP and cover can be visualized as a cusp catastrophe surface on which changes may occur rapidly and irreversibly. The mechanisms associated with a rapid shift from low to high erosion rate can be illustrated using percolation theory to incorporate spatial, temporal, and scale-dependent patterns of water storage capacity on a hillslope. Percolation theory demonstrates how hillslope runoff can undergo a threshold response to a minor change in storage capacity. Our conceptual model suggests that pinon and juniper contribute to accelerated erosion only under a limited range of site conditions which, however, may exist over large areas. C1 Univ Calif Los Alamos Natl Lab, Environm Sci Grp, Los Alamos, NM 87545 USA. US Geol Survey, Jemez Mt Field Stn, Bandelier Natl Monument, Los Alamos, NM 87544 USA. RP Davenport, DW (reprint author), Univ Calif Los Alamos Natl Lab, Environm Sci Grp, Mail Stop J495, Los Alamos, NM 87545 USA. RI Breshears, David/B-9318-2009 OI Breshears, David/0000-0001-6601-0058 NR 82 TC 136 Z9 143 U1 2 U2 27 PU SOC RANGE MANAGEMENT PI DENVER PA 1839 YORK ST, DENVER, CO 80206 USA SN 0022-409X J9 J RANGE MANAGE JI J. Range Manage. PD MAR PY 1998 VL 51 IS 2 BP 231 EP 240 DI 10.2307/4003212 PG 10 WC Agriculture, Dairy & Animal Science; Ecology SC Agriculture; Environmental Sciences & Ecology GA ZD323 UT WOS:000072673700017 ER PT J AU Tetlow, N Graham, AL Ingber, MS Subia, SR Mondy, LA Altobelli, SA AF Tetlow, N Graham, AL Ingber, MS Subia, SR Mondy, LA Altobelli, SA TI Particle migration in a couette apparatus: Experiment and modeling SO JOURNAL OF RHEOLOGY LA English DT Article ID CONCENTRATED SUSPENSIONS; SPHERES; FLOW AB Suspensions comprised of neutrally buoyant spheres in Newtonian fluids undergoing creeping flow in the annular region between two rotating, coaxial cylinders (a wide-gap Couette) display a bulk migration of particles towards regions of lower shear rate. A series of experiments are performed to characterize this particle migration, including the influence of particle size, surface roughness, and volume fraction. Little, if any, effect of particle surface roughness is observed. An existing continuum diffusive-flux model [Phillips et ni. (1992)] for predicting particle concentration profiles in monomodal suspensions is evaluated using the current series of experimental data. This model predicts a dependence of the migration rate on the square of the suspended particles' radius, a(2). whereas the present experiments indicate that systems with average particle volume fractions of 50% display a rate that scales with a(3). Previous use of the diffusive-flux model has assumed constant values far diffusion coefficients which serve as tuning parameters in the phenomenological equation. Here the experimental data are used to investigate variations of the model in which the diffusion coefficients depend upon either the local or global particle volume fraction. For initially uniform suspensions, the coefficients are found to be best modeled as functions of the local particle volume fraction. (C) 1998 The Society of Rheology. [S0148-6055(98)01002-5]. C1 Univ New Mexico, Dept Mech Engn, Albuquerque, NM 87131 USA. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Sandia Natl Labs, Albuquerque, NM 87185 USA. New Mexico Resonance, Albuquerque, NM 87108 USA. RP Ingber, MS (reprint author), Univ New Mexico, Dept Mech Engn, Albuquerque, NM 87131 USA. NR 21 TC 83 Z9 83 U1 0 U2 8 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0148-6055 J9 J RHEOL JI J. Rheol. PD MAR-APR PY 1998 VL 42 IS 2 BP 307 EP 327 DI 10.1122/1.550954 PG 21 WC Mechanics SC Mechanics GA ZB556 UT WOS:000072484400006 ER PT J AU Kleinke, H Franzen, HF AF Kleinke, H Franzen, HF TI Bonding and site preferences in the new quasi-binary Zr2.7Hf11.3P9 SO JOURNAL OF SOLID STATE CHEMISTRY LA English DT Article DE zirconium hafnium phosphide; structure and bonding; site preferences ID TA-NB-S; TRANSITION-METAL PHOSPHIDE; CRYSTAL-STRUCTURE; TERNARY-SYSTEM; COMPOUND AB The new quasi-binary Zr2.7Hf11.3P9 was synthesized by arc-melting of Zr, Hf, Co, and HfP in a ratio corresponding to the initial composition "Zr2.25Hf6.75Co2P4". Zr2.7Hf11.3P9 crystallizes in the Zr14P9 structure type, which is unknown in the binary Hf/P system. The ideal orthorhombic lattice dimensions (space group Pnnm (No. 58), Z = 4) were refined to a = 16.640(7) Angstrom, b = 27.40(2)Angstrom, c = 3.619(1)Angstrom, V = 1650(2)Angstrom(3). The structure consists of three-dimensional condensed one-, two-, and three-capped trigonal (Zr,Hf)(6)P prisms, occurring with numerous short M-M bonds (M = Zr, Hf), Each of the 15 metal sites is statistically occupied by a mixture of Zr and I-If, which varies significantly from site to site. The Hf/Zr ratio in a given site depends on the M-M and M-P interactions. The systematic increase of this ratio with increasing total bond order, as evaluated via Mulliken overlap populations and Pauling bond orders, can be understood based on the trend that I-If forms stronger M-M and M-P bonds than Zr. As expected for a metal-rich phosphide, band structure calculations for the hypothetical "Hf14P9" carried out with the extended Huckel approximation result in a significant density of states at the Fermi level. (C) 1998 Academic Press. C1 Iowa State Univ Sci & Technol, Ames Lab, Dept Energy, Ames, IA 50011 USA. RP Kleinke, H (reprint author), Univ Marburg, Fb Chem, D-35032 Marburg, Germany. NR 23 TC 10 Z9 10 U1 0 U2 1 PU ACADEMIC PRESS INC PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0022-4596 J9 J SOLID STATE CHEM JI J. Solid State Chem. PD MAR PY 1998 VL 136 IS 2 BP 221 EP 226 DI 10.1006/jssc.1997.7684 PG 6 WC Chemistry, Inorganic & Nuclear; Chemistry, Physical SC Chemistry GA ZR527 UT WOS:000073986500011 ER PT J AU Ridley, MK Palmer, DA Wesolowski, DJ Kettler, RM AF Ridley, MK Palmer, DA Wesolowski, DJ Kettler, RM TI Cadmium malonate complexation in aqueous sodium trifluoromethanesulfonate media to 75 degrees C; Including dissociation quotients of malonic acid SO JOURNAL OF SOLUTION CHEMISTRY LA English DT Article DE malonic acid; propanedioic acid; dissociation constants; cadmium; complexation constants; sodium trifluoromethanesulfonate; potentiometry ID POTENTIOMETRIC DETERMINATION; CHLORIDE MEDIA; ALUMINUM SPECIATION; ACETATE COMPLEXES; HIGH-TEMPERATURES; ZINC; THERMODYNAMICS; ELECTROLYTES; EQUILIBRIA; CONSTANTS AB The molal formation quotients for cadmium-malonate complexes were measured potentiometrically from 5 to 75 degrees C, at ionic strengths of 0.1, 0.3, 0.6 and 1.0 molal in aqueous sodium trifluoromethanesulfonate (NaTr) media. In addition, the stepwise dissociation quotients for malonic acid were measured in the same medium from 5 to 100 degrees C, at ionic strengths of 0.1, 0.3, 0.6, and 1.0 molal by the same method. The dissociation quotients for malonic acid were modeled as a function of temperature and ionic strength with empirical equations formulated such that the equilibrium constants at infinite dilution were consistent, within the error estimates, with the malonic acid dissociation constants obtained in NaCl media. The equilibrium constants calculated for the dissociation of malonic acid at 25 degrees C and infinite dilution are log K-1a = -2.86 +/- 0.01 and log K-2a = -5.71 +/- 0.01. A single Cd-malonate species, CdCH2C2O4, was identified from the complexation study and the formation quotients for this species were also modeled as a function of temperature and ionic strength. Thermodynamic parameters obtained by differentiating the equation with respect to temperature for the formation of CdCH2C2O4 at 25 degrees C and infinite dilution are: log K = 3.45 +/- 0.09, Delta H degrees = 7 +/- 6 kJ-mol(-1), Delta S degrees = 91 +/- 22 J-K-1-mol(-1), and Delta C-p(o) = 400 +/- 300 J-K-1-mol(-1). C1 Oak Ridge Natl Lab, Div Chem & Analyt Sci, Oak Ridge, TN 37831 USA. Univ Nebraska, Dept Geol, Lincoln, NE 68588 USA. RP Oak Ridge Natl Lab, Div Chem & Analyt Sci, POB 2008, Oak Ridge, TN 37831 USA. NR 42 TC 8 Z9 8 U1 0 U2 2 PU SPRINGER/PLENUM PUBLISHERS PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 0095-9782 EI 1572-8927 J9 J SOLUTION CHEM JI J. Solut. Chem. PD MAR PY 1998 VL 27 IS 3 BP 195 EP 216 DI 10.1023/A:1022638817245 PG 22 WC Chemistry, Physical SC Chemistry GA ZH917 UT WOS:000073160700001 ER PT J AU Garcia, AL Sonnino, G Mansour, MM AF Garcia, AL Sonnino, G Mansour, MM TI Long-ranged correlations in bounded nonequilibrium fluids SO JOURNAL OF STATISTICAL PHYSICS LA English DT Article DE fluctuating hydrodynamics; long-ranged correlations; direct simulation Monte Carlo; molecular dynamics ID THERMAL-EQUILIBRIUM; DILUTE GAS; FLUCTUATIONS; SCATTERING AB In a recent paper, Liu and Oppenheim [J. Stat. Phys. 86:179 (1997)] solve the fluctuating heat diffusion equation for a bounded system with a temperature gradient. This note demonstrates that, contrary to their claims, their solution for the temperature correlation function is indeed long-ranged and reduces to that of Garcia ct nl. [J. Star. Phys. 47:209 (1987)]. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Ctr Computat Sci & Engn, Berkeley, CA 94720 USA. Free Univ Brussels, Ctr Nonlinear Phenomena & Complex Syst, B-1050 Brussels, Belgium. San Jose State Univ, Dept Phys, San Jose, CA 95192 USA. RP Garcia, AL (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Ctr Computat Sci & Engn, Berkeley, CA 94720 USA. NR 12 TC 6 Z9 6 U1 0 U2 2 PU PLENUM PUBL CORP PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 0022-4715 J9 J STAT PHYS JI J. Stat. Phys. PD MAR PY 1998 VL 90 IS 5-6 BP 1489 EP 1492 DI 10.1023/A:1023260201995 PG 4 WC Physics, Mathematical SC Physics GA ZQ778 UT WOS:000073902100021 ER PT J AU Shastri, SD Dejus, RJ Haeffner, DR AF Shastri, SD Dejus, RJ Haeffner, DR TI Experimental characterization of APS undulator A at high photon energies (50-200 keV) SO JOURNAL OF SYNCHROTRON RADIATION LA English DT Article DE undulators; insertion devices; X-ray sources; high-energy X-rays ID X-RAY-DIFFRACTION; SYNCHROTRON-RADIATION; SCATTERING AB The considerable intensity of Advanced Photon Source (APS) undulator A as a source of high-energy X-rays permits the performance of numerous types of experiments that require such photon energies. Measured and calculated properties, in the 50-200 keV range, of the X-ray beam from undulator A, installed in sector 1 of the APS, are presented. The flux spectra observed at various gaps agree well with calculations that incorporate the actual magnetic field within the device and the emittance and energy spread of the stored positrons. The field errors and energy spread cause the X-ray beam to lose undulator radiation properties at high energies, as seen in the smeared-out spectral harmonics and increased beam divergence, giving resemblance to a low-K wiggler source. Owing to the wiggler-like behavior in this photon-energy range, the optimal operating condition for undulator A is in the vicinity of the closed-gap setting, corresponding to a maximum critical energy. C1 Argonne Natl Lab, Adv Photon Source, Argonne, IL 60439 USA. RP Shastri, SD (reprint author), Argonne Natl Lab, Adv Photon Source, Argonne, IL 60439 USA. NR 15 TC 10 Z9 10 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 MAR 1 PY 1998 VL 5 BP 67 EP 71 DI 10.1107/S090904959701368X PN 2 PG 5 WC Instruments & Instrumentation; Optics; Physics, Applied SC Instruments & Instrumentation; Optics; Physics GA ZL322 UT WOS:000073421100001 PM 16687805 ER PT J AU Ressler, T AF Ressler, T TI WinXAS: a program for X-ray absorption spectroscopy data analysis under MS-Windows SO JOURNAL OF SYNCHROTRON RADIATION LA English DT Article DE XAFS data analysis; FEFF; time-resolved studies; energy-dispersive XAS AB WinXAS is a new X-ray absorption spectroscopy (XAS) data-analysis program. It runs under the operating system MS-Windows 95/NT and offers several unique features. It has a user-friendly graphical environment and is capable of reading a variety of data formats. It contains a number of useful numerical algorithms beyond those used in conventional XAS analysis and offers a simple interface to the ab-initio theoretical code FEFF. The availability of fast macros in WinXAS makes it particularly useful for on-line data examination at synchrotron radiation facilities during XAS experiments as well as for the analysis of multiple-scan data such as those from time-resolved experiments. C1 Univ Hamburg, Inst Phys Chem, D-20146 Hamburg, Germany. RP Ressler, T (reprint author), Univ Calif Lawrence Livermore Natl Lab, POB 808,L-369, Livermore, CA 94551 USA. NR 11 TC 1024 Z9 1028 U1 7 U2 58 PU MUNKSGAARD INT PUBL LTD PI COPENHAGEN PA 35 NORRE SOGADE, PO BOX 2148, DK-1016 COPENHAGEN, DENMARK SN 0909-0495 J9 J SYNCHROTRON RADIAT JI J. Synchrot. Radiat. PD MAR 1 PY 1998 VL 5 BP 118 EP 122 DI 10.1107/S0909049597019298 PN 2 PG 5 WC Instruments & Instrumentation; Optics; Physics, Applied SC Instruments & Instrumentation; Optics; Physics GA ZL322 UT WOS:000073421100009 PM 16687813 ER PT J AU Zhu, YT Butt, DP Taylor, ST Lowe, TC AF Zhu, YT Butt, DP Taylor, ST Lowe, TC TI Evaluation of a modified Weibull distribution for describing the strength of ceramic fibers and whiskers with varying diameters SO JOURNAL OF TESTING AND EVALUATION LA English DT Article DE modified Weibull distribution; strength; varying diameter; fiber; whisker ID COMPOSITE-MATERIALS; CARBON-FIBERS AB A modified Weibull distribution is evaluated for characterizing the statistical strength of ceramic fibers and whiskers with varying diameters from filament to filament. Many commercial ceramic fibers and whiskers have a significant range of diameters. A single modal Weibull distribution is found inadequate to describe the statistical strength of these fibers and whiskers because of the effect of fiber diameter variation on strength. Procedures for extracting distribution parameters for the modified Weibull distribution from experimental data an presented. Comparison of the modified Weibull distribution with the single-modal Weibull distribution is made far the strength data from. Nicalon fibers, Nextel (Al2O3) fibers, hydridopolysilazalane (HPZ) Si-N-C-O fibers, Al2O3 whiskers, Si3N4 whiskers, and SiC whiskers. Due to its ability to account for the diameter effect on strength, the modified Weibull distribution can yield a more accurate beta value than the single-modal Weibull distribution. The modified Weibull distribution is shown to fit experimental data well and is recommended for characterizing the strength of ceramic fibers and whiskers, the diameters of which vary from filament to filament. C1 Univ Calif Los Alamos Natl Lab, Div Mat Sci & Technol, Los Alamos, NM 87545 USA. RP Zhu, YT (reprint author), Univ Calif Los Alamos Natl Lab, Div Mat Sci & Technol, Los Alamos, NM 87545 USA. RI Zhu, Yuntian/B-3021-2008; Butt, Darryl/B-7480-2008 OI Zhu, Yuntian/0000-0002-5961-7422; Butt, Darryl/0000-0003-4501-8864 NR 28 TC 1 Z9 1 U1 0 U2 2 PU AMER SOC TESTING MATERIALS PI W CONSHOHOCKEN PA 100 BARR HARBOR DR, W CONSHOHOCKEN, PA 19428-2959 USA SN 0090-3973 J9 J TEST EVAL JI J. Test. Eval. PD MAR PY 1998 VL 26 IS 2 BP 144 EP 150 PG 7 WC Materials Science, Characterization & Testing SC Materials Science GA ZJ973 UT WOS:000073272300009 ER PT J AU Matula, TJ Hallaj, IM Cleveland, RO Crum, LA Moss, WC Roy, RA AF Matula, TJ Hallaj, IM Cleveland, RO Crum, LA Moss, WC Roy, RA TI The acoustic emissions from single-bubble sonoluminescence SO JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA LA English DT Article ID CAVITATION; DYNAMICS AB Detailed measurements of the acoustic emissions from single-bubble sonoluminescence have been made utilizing both a small 200-mu m aperture PVDF needle hydrophone, and a focused 10-MHz transducer. Signals obtained with the needle hydrophone show a fast (5.2 ns), probably bandlimited rise time and relatively large pulse amplitude (approximate to 1.7 bar). Below the sonoluminescence threshold, the emissions are observable, but considerably smaller in amplitude (approximate to 0.4 bar). Several signals are observed with the 10-MHz transducer and correspond to acoustic emissions from the bubble during the main collapse, as well as from the rebounds. Experiments reveal that the acoustic emissions occur at or near the minimum bubble radius. Calculations of the peak pressures and pulse widths are compared with experimental data. (C) 1998 Acoustical Society of America. [S0001-4966(98)03203-2]. C1 Univ Washington, Appl Phys Lab, Seattle, WA 98105 USA. Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. Boston Univ, Dept Aerosp & Mech Engn, Boston, MA 02215 USA. RP Matula, TJ (reprint author), Univ Washington, Appl Phys Lab, 1013 NE 40th St, Seattle, WA 98105 USA. RI Matula, Tom/I-5346-2012; Cleveland, Robin/G-9468-2013; OI Roy, Ronald/0000-0001-6394-5667 NR 28 TC 48 Z9 48 U1 1 U2 8 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0001-4966 J9 J ACOUST SOC AM JI J. Acoust. Soc. Am. PD MAR PY 1998 VL 103 IS 3 BP 1377 EP 1382 DI 10.1121/1.421279 PG 6 WC Acoustics; Audiology & Speech-Language Pathology SC Acoustics; Audiology & Speech-Language Pathology GA ZB933 UT WOS:000072522900017 ER PT J AU Avellaneda, M Swart, PJ AF Avellaneda, M Swart, PJ TI Calculating the performance of 1-3 piezoelectric composites for hydrophone applications: An effective medium approach SO JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA LA English DT Article ID NEGATIVE POISSON RATIOS; TRANSDUCER APPLICATIONS; DIFFERENTIAL SCHEME; LEAD-TITANATE; MODULI; EPOXY AB A new method is presented for evaluating the performance of 1-3 polymer/piezoelectric ceramic composites for hydrophone applications. The Poisson's ratio effect, i.e., the enhancement of the hydrostatic performance which can be achieved by mixing piezoelectric ceramics with polymers, is studied in detail. Using an "effective medium" approach, algebraic expressions are derived for the composite hydrostatic charge coefficient d(h), the hydrostatic figure of merit d(h)g(h), and the hydrostatic electromechanical coupling coefficient k(h) in terms of the properties of the constituent materials, the ceramic volume fraction, and a microstructural parameter p. The high contrast in stiffness and dielectric constants existing between the two phases can be exploited to derive simple, geometry-independent approximations which explain quantitatively the Poisson's ratio effect. It is demonstrated that the stiffness and the Poisson's ratio of the polymer matrix play a crucial role in enhancing hydrophone performance. Using a differential scheme to model the parameter p, we evaluate d(h), d(h)g(h), and k(h) for polymer/piezoelectric ceramic systems at varying compositions. Several examples involving Pb (Zr, Ti)O-3 and (Pb, Ca)TiO3 piezoelectric ceramics are given to illustrate the theory. (C) 1998 Acoustical Society of America. [S0001-4966(97)00506-7]. C1 NYU, Courant Inst Math Sci, New York, NY 10012 USA. Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. RP NYU, Courant Inst Math Sci, 251 Mercer St, New York, NY 10012 USA. NR 41 TC 39 Z9 40 U1 1 U2 9 PU ACOUSTICAL SOC AMER AMER INST PHYSICS PI MELVILLE PA STE 1 NO 1, 2 HUNTINGTON QUADRANGLE, MELVILLE, NY 11747-4502 USA SN 0001-4966 EI 1520-8524 J9 J ACOUST SOC AM JI J. Acoust. Soc. Am. PD MAR PY 1998 VL 103 IS 3 BP 1449 EP 1467 DI 10.1121/1.421306 PG 19 WC Acoustics; Audiology & Speech-Language Pathology SC Acoustics; Audiology & Speech-Language Pathology GA ZB933 UT WOS:000072522900025 ER PT J AU Holm, EA AF Holm, EA TI Surface formation energy for intergranular fracture in two-dimensional polycrystals SO JOURNAL OF THE AMERICAN CERAMIC SOCIETY LA English DT Article; Proceedings Paper CT 99th Annual Meeting of the American-Ceramic-Society CY MAY 04-07, 1997 CL CINCINNATI, OHIO SP Amer Ceram Soc ID COMPUTER-SIMULATION; GRAIN-GROWTH; MODEL AB A global energy minimization method for calculating intergranular fracture surfaces which minimize surface formation energy was developed using standard graph algorithms, The intergranular fracture of equiaxed, single-phase, polycrystalline grain structures was examined under a variety of energetic conditions. In energetically isotropic systems the minimum energy fracture surface has length 1.1 times the sample width independent of grain size, A criterion for fracture mode was derived for this case. Using a ball-and-spring model, local mechanical effects were found to increase fracture length by at most 5% in isotropic systems, The presence of typical low-energy, low-angle grain boundaries minimally affects intergranular fracture path, but may alter the preferred fracture mode, In systems with randomly dispersed, very weak boundaries (i.e., micro-cracks), fracture surfaces veer to follow low surface formation energy boundaries, resulting in tortuous, low-energy fracture paths, and intergranular fracture is strongly preferred. C1 Sandia Natl Labs, Theoret & Computat Mat Modeling Dept, Albuquerque, NM 87185 USA. RP Holm, EA (reprint author), Sandia Natl Labs, Theoret & Computat Mat Modeling Dept, POB 5800, Albuquerque, NM 87185 USA. RI Holm, Elizabeth/S-2612-2016 OI Holm, Elizabeth/0000-0003-3064-5769 NR 14 TC 13 Z9 13 U1 1 U2 1 PU AMER CERAMIC SOC PI WESTERVILLE PA 735 CERAMIC PLACE, PO BOX 6136, WESTERVILLE, OH 43081-6136 USA SN 0002-7820 J9 J AM CERAM SOC JI J. Am. Ceram. Soc. PD MAR PY 1998 VL 81 IS 3 BP 455 EP 459 PG 5 WC Materials Science, Ceramics SC Materials Science GA ZC554 UT WOS:000072592300001 ER PT J AU Tikare, V Holm, EA AF Tikare, V Holm, EA TI Simulation of grain growth and pore migration in a thermal gradient SO JOURNAL OF THE AMERICAN CERAMIC SOCIETY LA English DT Article; Proceedings Paper CT 99th Annual Meeting of the American-Ceramic-Society CY MAY 04-07, 1997 CL CINCINNATI, OHIO SP Amer Ceram Soc ID COMPUTER-SIMULATION; POTTS-MODEL; KINETICS AB The Potts Monte Carlo simulation was used to simulate microstructural evolution in uranium dioxide fuel rods, During service, grain growth, pore migration, and thermal segregation of the pores and UO2 occur in the rods in a thermal gradient. In this investigation, we developed a model which simulates simultaneous grain growth, pore migration, and thermal segregation of the pores and UO2 in a temperature gradient, Grain growth in a thermal gradient was simulated using the Monte Carlo Potts model technique developed by Anderson, Srolovitz, and co-workers. Pore migration was simulated using conserved dynamics with minimum-energy exchanges at a finite temperature, A temperature gradient was introduced into the model via interfacial mobility gradient, Finally, thermal segregation of the pores and UO2 was achieved by introducing a heat of migration term, Delta E-t, which biased the motion of porosity to the high-temperature region, The development of this model is described and the incorporation of the proper physics of pore migration and thermal segregation is discussed. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Tikare, V (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. RI Holm, Elizabeth/S-2612-2016 OI Holm, Elizabeth/0000-0003-3064-5769 NR 12 TC 53 Z9 56 U1 1 U2 11 PU AMER CERAMIC SOC PI WESTERVILLE PA 735 CERAMIC PLACE, PO BOX 6136, WESTERVILLE, OH 43081-6136 USA SN 0002-7820 J9 J AM CERAM SOC JI J. Am. Ceram. Soc. PD MAR PY 1998 VL 81 IS 3 BP 480 EP 484 PG 5 WC Materials Science, Ceramics SC Materials Science GA ZC554 UT WOS:000072592300005 ER PT J AU Tikare, V Cawley, JD AF Tikare, V Cawley, JD TI Application of the Potts model to simulation of ostwald ripening SO JOURNAL OF THE AMERICAN CERAMIC SOCIETY LA English DT Article ID PARTICLE DIFFUSION PROBLEM; DRIVEN GRAIN-GROWTH; COMPUTER-SIMULATION; VOLUME FRACTION; 2 DIMENSIONS; GEOMETRY; TOPOLOGY AB Many models have been developed to simulate microstructural evolution in recent years, Among these is the Monte Carlo Potts model used to simulate microstructural evolution under a wide range of conditions for a variety of microstructural evolution processes. An advantage of the Potts model is that the thermodynamic and kinetic characteristics are inherent to the technique. In this paper, grain growth by Ostwald ripening will be used as an example to demonstrate how a well-designed Potts model need not explicitly specify the thermodynamics of the process; rather, it should rely on the statistical-mechanical nature of the model to simulate the physics of the process, Simulation of Ostwald ripening requires two components forming two-phase, solid grains in a liquid matrix with solubility of the components forming the solid phase in the liquid phase, Another requirement is Gibbs-Thomson's behavior for the solid grains where solubility is inversely proportional to size. The incorporation of these characteristics into the Potts model using the statistical-mechanical nature of the system will be demonstrated in this paper. C1 Sandia Natl Labs, Albuquerque, NM 87110 USA. Case Western Reserve Univ, Cleveland, OH 44106 USA. RP Tikare, V (reprint author), Sandia Natl Labs, Albuquerque, NM 87110 USA. NR 21 TC 18 Z9 19 U1 0 U2 5 PU AMER CERAMIC SOC PI WESTERVILLE PA 735 CERAMIC PLACE, PO BOX 6136, WESTERVILLE, OH 43081-6136 USA SN 0002-7820 J9 J AM CERAM SOC JI J. Am. Ceram. Soc. PD MAR PY 1998 VL 81 IS 3 BP 485 EP 491 PG 7 WC Materials Science, Ceramics SC Materials Science GA ZC554 UT WOS:000072592300006 ER PT J AU Cleri, F Phillpot, SR Wolf, D Yip, S AF Cleri, F Phillpot, SR Wolf, D Yip, S TI Atomistic simulations of materials fracture and the link between atomic and continuum length scales SO JOURNAL OF THE AMERICAN CERAMIC SOCIETY LA English DT Article; Proceedings Paper CT 99th Annual Meeting of the American-Ceramic-Society CY APR 24-MAY 07, 1997 CL CINCINNATI, OH SP Amer Ceram Soc ID MOLECULAR-DYNAMICS METHOD; BRITTLE-DUCTILE TRANSITION; DISLOCATION NUCLEATION; CRACK TIPS; ALPHA-IRON; CRYSTALS; EMISSION; BEHAVIOR; PROPAGATION; INTERFACES AB The macroscopic fracture response of real materials originates from the competition and interplay of several atomic-scale mechanisms of decohesion and shear, such as interplanar cleavage and dislocation nucleation and motion. These phenomena involve processes over a wide range of length scales, from the atomic to the macroscopic, We briefly review the attempts to span these length scales in dislocation and fracture modeling by (1) fully atomistic large-scale simulations of millions of atoms or more, approaching the continuum limit from the "bottom-up"; (2) directly coupling atomic-scale simulations and continuum mechanics, in a "top-down" approach; and (3) by defining a set of variables common to atomistic simulations and continuum mechanics and feeding the results of atomistic simulations into continuum-mechanics models in the form of constitutive relations, For this latter approach we discuss in detail the issues crucial to ensuring the consistency of the atomistic results and continuum mechanics. A case study of the constitutive-relation approach is presented for the problem of dislocation nucleation from a crack tip in a crystal under stress; a comparison of the results of atomistic simulations to the Peierls-Nabarro continuum model is made. C1 Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. ENEA, Ctr Ric Casaccia, Div Mat Avanzati, I-00100 Rome, Italy. MIT, Dept Nucl Engn, Cambridge, MA 02139 USA. RP Cleri, F (reprint author), Argonne Natl Lab, Div Mat Sci, 9700 S Cass Ave, Argonne, IL 60439 USA. RI Phillpot, Simon/J-9117-2012; OI Phillpot, Simon/0000-0002-7774-6535 NR 88 TC 46 Z9 46 U1 0 U2 9 PU WILEY-BLACKWELL PI MALDEN PA COMMERCE PLACE, 350 MAIN ST, MALDEN 02148, MA USA SN 0002-7820 J9 J AM CERAM SOC JI J. Am. Ceram. Soc. PD MAR PY 1998 VL 81 IS 3 BP 501 EP 516 PG 16 WC Materials Science, Ceramics SC Materials Science GA ZC554 UT WOS:000072592300008 ER PT J AU Fan, D Chen, LQ Chen, SPP AF Fan, D Chen, LQ Chen, SPP TI Numerical simulation of Zener pinning with growing second-phase particles SO JOURNAL OF THE AMERICAN CERAMIC SOCIETY LA English DT Article; Proceedings Paper CT 99th Annual Meeting of the American-Ceramic-Society CY APR 24-MAY 07, 1997 CL CINCINNATI, OH SP Amer Ceram Soc ID GRAIN-GROWTH; COMPUTER-SIMULATION; COMPOSITES; MODEL AB The Zener pinning effect with growing second-phase particles in Al2O3-ZrO2 composite systems were studied by two-dimensional (2-D) computer simulations using a diffuse-interface field model, In these systems, ail second-phase particles are distributed at grain corners and boundaries, The second-phase particles grow continuously, and the motion of grain boundaries of the matrix phase is pinned by the second-phase particles which coarsen through the Ostwald ripening mechanism, i.e., long-range diffusion, It is shown that both matrix grains and second-phase particles grow following the power-growth law, R-t(m) - R-0(m) = kt with m = 3, It is found that the mean size of the matrix phase (D) depends linearly on the mean size of the second-phase particles (r) for all volume fractions of second phase from 10% to 40%, which agrees well with experimental results. It is shown that D/r is proportional to the volume fraction of the second phase (f) as f(-1/2) for a volume fraction less than 30%, which agrees with Hillert and Srolovitz's predictions for 2-D systems, while experimental results from 2-D cross sections of three-dimensional (3-D) Al2O3-rich systems showed that either a f(-1/2) or a f(-1/3) relation might be possible, It is also found that D/r is not proportional to f(-1/3) and f(-1) in 2-D simulations, which suggests that the Zener pinning effect can be very different in 2-D and 3-D systems. C1 Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. Penn State Univ, Dept Mat Sci & Engn, University Pk, PA 16802 USA. RP Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. RI Chen, LongQing/I-7536-2012 OI Chen, LongQing/0000-0003-3359-3781 NR 21 TC 43 Z9 44 U1 1 U2 12 PU WILEY-BLACKWELL PI HOBOKEN PA 111 RIVER ST, HOBOKEN 07030-5774, NJ USA SN 0002-7820 EI 1551-2916 J9 J AM CERAM SOC JI J. Am. Ceram. Soc. PD MAR PY 1998 VL 81 IS 3 BP 526 EP 532 PG 7 WC Materials Science, Ceramics SC Materials Science GA ZC554 UT WOS:000072592300010 ER PT J AU Janney, MA Omatete, OO Walls, CA Nunn, SD Ogle, RJ Westmoreland, G AF Janney, MA Omatete, OO Walls, CA Nunn, SD Ogle, RJ Westmoreland, G TI Development of low-toxicity gelcasting systems SO JOURNAL OF THE AMERICAN CERAMIC SOCIETY LA English DT Article AB A series of low-toxicity gelcasting systems has been developed, The reagents used in these systems have very low acute toxicity. The new systems perform at least as well as, and in some cases better than, the original acrylamide-based system, The development of these systems is described herein, including the search for new gel compositions, the study of suspensions made with the new gel precursor solutions, and pyrolysis of the dried gels and gelcast parts, Applications of the new gelcasting systems include complex silicon nitride parts, large-diameter rings, rapid prototyping by green machining, and metal-powder gel casting. C1 Oak Ridge Natl Lab, Div Met & Ceram, Oak Ridge, TN 37831 USA. RP Janney, MA (reprint author), Oak Ridge Natl Lab, Div Met & Ceram, POB 2008, Oak Ridge, TN 37831 USA. NR 13 TC 237 Z9 265 U1 6 U2 47 PU AMER CERAMIC SOC PI WESTERVILLE PA 735 CERAMIC PLACE, PO BOX 6136, WESTERVILLE, OH 43081-6136 USA SN 0002-7820 J9 J AM CERAM SOC JI J. Am. Ceram. Soc. PD MAR PY 1998 VL 81 IS 3 BP 581 EP 591 PG 11 WC Materials Science, Ceramics SC Materials Science GA ZC554 UT WOS:000072592300017 ER PT J AU Zhu, YT Taylor, ST Stout, MG Butt, DP Lowe, TC AF Zhu, YT Taylor, ST Stout, MG Butt, DP Lowe, TC TI Kinetics of thermal, passive oxidation of Nicalon fibers SO JOURNAL OF THE AMERICAN CERAMIC SOCIETY LA English DT Article ID SOLID-STATE REACTIONS; SILICON-CARBIDE; SIC FIBERS; STABILITY; DEGRADATION; BEHAVIOR AB The oxidation of Nicalon(TM) fibers is a concern, because of its potential as a reinforcement of high-temperature composites, whose service conditions involve high-temperature, oxidizing environments, Two limiting types of oxidation mechanisms are often used to describe the kinetics: chemical-reaction-controlled oxidation, at small oxide thicknesses, and diffusion-controlled oxidation, at large oxide thicknesses, Neither mechanism can satisfactorily describe the intermediate region where the oxidation kinetics are controlled jointly by both the chemical reaction rate at the interface and the diffusion of oxygen through the oxide layer. To describe the entire oxidation process with a general relationship, one must consider all stages of the oxidation process, namely (i) adsorption of oxygen at the outer surface of the oxide, (ii) diffusion of oxygen from the outer surface toward the interface,where oxidation occurs, and (iii) reaction at the interface to form a new layer of oxide, Previously, a very useful general relationship was derived for the oxidation kinetics for a flat plate, which could account for all three stages of oxidation, However, that equation is inadequate to describe the oxidation of cylindrical fibers, because the effective area for oxygen diffusion changes along the diffusion path and the oxidation interfacial area decreases as the oxide thickness increases for cylindrical fibers, In this paper, we have derived a general kinetic relationship for the oxidation of cylindrical fibers, which can account for all stages of oxidation, Comparison of the theory with experimental data of Nicalon(TM) fibers shows good agreement. C1 Univ Calif Los Alamos Natl Lab, Div Mat Sci & Technol, Los Alamos, NM 87545 USA. RP Zhu, YT (reprint author), Univ Calif Los Alamos Natl Lab, Div Mat Sci & Technol, Los Alamos, NM 87545 USA. RI Zhu, Yuntian/B-3021-2008; Butt, Darryl/B-7480-2008 OI Zhu, Yuntian/0000-0002-5961-7422; Butt, Darryl/0000-0003-4501-8864 NR 22 TC 32 Z9 32 U1 1 U2 6 PU AMER CERAMIC SOC PI WESTERVILLE PA 735 CERAMIC PLACE, PO BOX 6136, WESTERVILLE, OH 43081-6136 USA SN 0002-7820 J9 J AM CERAM SOC JI J. Am. Ceram. Soc. PD MAR PY 1998 VL 81 IS 3 BP 655 EP 660 PG 6 WC Materials Science, Ceramics SC Materials Science GA ZC554 UT WOS:000072592300026 ER PT J AU Lee, WY Lara-Curzio, E More, KL AF Lee, WY Lara-Curzio, E More, KL TI Multilayered oxide interphase concept for ceramic-matrix composites SO JOURNAL OF THE AMERICAN CERAMIC SOCIETY LA English DT Article AB Hi-Nicalon/SiC minicomposite specimens containing three oxide interphase layers (amorphous SiO2, monoclinic ZrO2, and amorphous SiO2) were prepared by chemical vapor deposition. The minicomposites exhibited graceful composite failure behavior with reasonable load-carrying capability in room-temperature tensile tests. Much of the composite behavior and load-carrying capability was retained even after matrix precracking and subsequent oxidation in air at 960 degrees C for 10 h. In both the as-prepared and oxidized specimens, crack deflection and fiber pull-out occurred preferentially within the multilayered interphase region. The potential merits and uncertainties associated with this multilayered oxide interphase approach were discussed in the context of designing environmentally durable interfaces for ceramic-matrix composites. C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Lee, WY (reprint author), Stevens Inst Technol, Dept Mat Sci & Engn, Hoboken, NJ 07030 USA. RI More, Karren/A-8097-2016 OI More, Karren/0000-0001-5223-9097 NR 7 TC 30 Z9 31 U1 0 U2 3 PU AMER CERAMIC SOC PI WESTERVILLE PA 735 CERAMIC PLACE, PO BOX 6136, WESTERVILLE, OH 43081-6136 USA SN 0002-7820 J9 J AM CERAM SOC JI J. Am. Ceram. Soc. PD MAR PY 1998 VL 81 IS 3 BP 717 EP 720 PG 4 WC Materials Science, Ceramics SC Materials Science GA ZC554 UT WOS:000072592300036 ER PT J AU Viecelli, JA AF Viecelli, JA TI On the possibility of singular low-frequency spectra and Levy law persistence statistics in the planetary-scale turbulent circulation SO JOURNAL OF THE ATMOSPHERIC SCIENCES LA English DT Article ID NORTHERN-HEMISPHERE WINTER; MULTIPLE FLOW REGIMES; LONG-RANGE PREDICTION; FINITE-SAMPLE SIZE; METEOROLOGICAL STATISTICS; SOUTHERN OSCILLATION; ANGULAR-MOMENTUM; VARIABILITY; WAVES; MODEL AB Long-time integrations of general circulation models with constant forcing and idealized models of turbulent rotating discrete vortex flows in a planar dish have consistently yielded red ultralow-frequency spectra. A red spectrum having an integrable fractional-exponent singularity at the frequency origin is associated with occasional long-lasting random persistence intervals described by probability distributions with Levy law tails, suggesting this type of persistence distribution may be relevant to the planetary scale turbulence. Decade-length records of 200-mb wind velocity fluctuations from North American 12-h radiosonde data are examined for the presence of Levy statistics, and the convergence properties of errors in means and variances computed from finite length time-series samples containing random persistence intervals governed by Levy probability laws are compared with the convergence properties corresponding to the low-frequency white-noise hypothesis. Some implications for estimating climatic means and variances are discussed. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Viecelli, JA (reprint author), Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. NR 37 TC 7 Z9 7 U1 1 U2 2 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0022-4928 J9 J ATMOS SCI JI J. Atmos. Sci. PD MAR 1 PY 1998 VL 55 IS 5 BP 677 EP 689 DI 10.1175/1520-0469(1998)055<0677:OTPOSL>2.0.CO;2 PG 13 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA YZ755 UT WOS:000072288400001 ER PT J AU Schmuki, P Virtanen, S Isaacs, HS Ryan, MP Davenport, AJ Bohni, H Stenberg, T AF Schmuki, P Virtanen, S Isaacs, HS Ryan, MP Davenport, AJ Bohni, H Stenberg, T TI Electrochemical behavior of Cr2O3/Fe2O3 artificial passive films studied by in situ XANES SO JOURNAL OF THE ELECTROCHEMICAL SOCIETY LA English DT Article ID IRON-CHROMIUM ALLOYS; IN-SITU; PERCOLATION MODEL; FE-CR; SPECTROSCOPY; STEELS; AES AB The electrochemical behavior of thin sputter-deposited mixed Cr2O3/Fe2O3 oxide films with Cr2O3-contents of 10, 20, 50, and 90% was studied with in situ X-ray absorption near edge spectroscopy (XANES). These measurements gave information on the chemical states and dissolution rates during anodic and cathodic polarization in different electrolytes. Bt low Cr oxide concentrations, the films dissolve when cathodically polarized and are resistant to dissolution when polarized in the anodic direction. At high Cr2O3 concentrations, dissolution occurs when the films are anodically polarized, but the films are stable against cathodic dissolution. In the intermediate Cr oxide concentration range, the oxides neither dissolve under anodic nor cathodic polarization. However, in all the cases, even when no dissolution takes place, the species show electroactivity in that the redox reactions Fe3+ --> Fe2+ and Cr3+ --> Cr6+ Can take place under cathodic and anodic polarization, respectively. In the mixed oxides a solid-state conversion takes place in the iron oxide phase during reduction, whereas the oxidation of the chromium oxide phase converts only the outermost layer. An acidic environment accelerates both anodic and cathodic dissolution, associated with chemical dissolution of the iron oxide. The results further show that critical threshold values exist for the dissolution resistance of the oxide. These values are different for anodic and cathodic reactions and further strongly depend on the solution chemistry. C1 Swiss Fed Inst Technol, ETH Honggerberg, Inst Mat Chem & Corros, CH-8093 Zurich, Switzerland. Brookhaven Natl Lab, Dept Appl Sci, Div Mat Sci, Upton, NY 11973 USA. Univ Manchester, Manchester Mat Sci Ctr, Manchester M1 7HS, Lancs, England. Tampere Univ Technol, Inst Mat Sci, FIN-33101 Tampere, Finland. RP Schmuki, P (reprint author), Ecole Polytech Fed Lausanne, Swiss Fed Inst Technol, Dept Mat Sci, LC DMX, CH-1015 Lausanne, Switzerland. RI Davenport, Alison/J-6089-2013; Virtanen, Sannakaisa/N-3699-2015 OI Davenport, Alison/0000-0003-0853-515X; Virtanen, Sannakaisa/0000-0002-7179-7593 NR 29 TC 76 Z9 77 U1 0 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 MAR PY 1998 VL 145 IS 3 BP 791 EP 801 DI 10.1149/1.1838347 PG 11 WC Electrochemistry; Materials Science, Coatings & Films SC Electrochemistry; Materials Science GA YZ478 UT WOS:000072258100018 ER PT J AU Darling, R Newman, J AF Darling, R Newman, J TI Modeling side reactions in composite LiyMn2O4 electrodes SO JOURNAL OF THE ELECTROCHEMICAL SOCIETY LA English DT Article ID PT/LAMBDA-MNO2 ELECTRODE; INSERTION CELL; LI+ INSERTION; AQUEOUS-PHASE; ION CELLS; LITHIUM; DISCHARGE; CAPACITY; LIMN2O4; CARBON AB A Li/1 M LIClO4 in propylene carbonate (PC)/Li8Mn2O4 cell is used to investigate the influence of side reactions on the current-potential behavior of intercalation electrodes. Slow cyclic voltammograms and self-discharge data are combined to estimate, simultaneously, the reversible potential vs state-of-charge curve for the host material and the kinetic parameters for the side reaction. This information is then used, together with estimates of the solid-state diffusion coefficient and main reaction exchange current density, in a mathematical model of the system. Predictions from the model compare favorably with continuous cycling results and galvanostatic experiments with periodic current interruptions. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Environm Energy Technol Div, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Chem Engn, Berkeley, CA 94720 USA. RP Darling, R (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Environm Energy Technol Div, Berkeley, CA 94720 USA. RI Newman, John/B-8650-2008 OI Newman, John/0000-0002-9267-4525 NR 26 TC 85 Z9 87 U1 4 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 MAR PY 1998 VL 145 IS 3 BP 990 EP 998 DI 10.1149/1.1838376 PG 9 WC Electrochemistry; Materials Science, Coatings & Films SC Electrochemistry; Materials Science GA YZ478 UT WOS:000072258100047 ER PT J AU Leeper, DA Taylor, BE AF Leeper, DA Taylor, BE TI Insect emergence from a South Carolina (USA) temporary wetland pond, with emphasis on the Chironomidae (Diptera) SO JOURNAL OF THE NORTH AMERICAN BENTHOLOGICAL SOCIETY LA English DT Article DE Insecta; emergence; Chironomidae; depression wetlands; temporary ponds; Carolina bays; South Carolina ID COMMUNITY STRUCTURE; NORTHWESTERN ONTARIO; AQUATIC INSECTS; WATER CHEMISTRY; ABUNDANCE; CANADA; PHENOLOGY; DURATION; DROUGHT; POOLS AB At Rainbow Bay, a 1.5-ha temporary wetland pond in South Carolina, 115 taxa of aquatic and semi-aquatic insects from 29 families representing 7 orders (Diptera, Coleoptera, Hemiptera, Trichoptera, Megaloptera, Odonata, Ephemeroptera) were collected using emergence traps from Math 1992 through June 1993, a period including 2 hydroperiod cycles. The Chironomidae were the most diverse group (59 species), followed by the Coleoptera (23 species). The Chironomini were the most diverse and abundant chironomids. The chironomid assemblage included many taxa with wide distributions from a variety of southeastern habitats, but several species, including some of the dominant species, are typical of acidic, dystrophic habitats. Several taxa of chironomids collected at the wetland represent new species or generic records for South Carolina or the southeastern USA. Ckironomid assemblages at Rainbow Bay and other local depression wetlands were moderately dissimilar, in accordance with reports for other aquatic organisms. Most other insect groups collected at Rainbow Bay are common to other depression wetlands of the region. Cumulative insect emergence was moderate (2774 and 1017 individuals m(-2) y(-1) in 1992 and 1993), and was dominated by the Chironomidae (93% of the total). Annual variation in emergence was probably most strongly influenced by annual variation in hydrology. C1 Univ Georgia, Savannah River Ecol Lab, Aiken, SC 29802 USA. RP Leeper, DA (reprint author), SW Florida Water Management Dist, 2379 Broad St, Brooksville, FL 34609 USA. NR 69 TC 30 Z9 34 U1 0 U2 13 PU NORTH AMER BENTHOLOGICAL SOC PI LAWRENCE PA 1041 NEW HAMSPHIRE STREET, LAWRENCE, KS 66044 USA SN 0887-3593 J9 J N AM BENTHOL SOC JI J. N. Am. Benthol. Soc. PD MAR PY 1998 VL 17 IS 1 BP 54 EP 72 DI 10.2307/1468051 PG 19 WC Ecology; Marine & Freshwater Biology SC Environmental Sciences & Ecology; Marine & Freshwater Biology GA ZL298 UT WOS:000073418600004 ER PT J AU Page, RH Schaffers, KI Waide, PA Tassano, JB Payne, SA Krupke, WF Bischel, WK AF Page, RH Schaffers, KI Waide, PA Tassano, JB Payne, SA Krupke, WF Bischel, WK TI Upconversion-pumped luminescence efficiency of rare-earth-doped hosts sensitized with trivalent ytterbium SO JOURNAL OF THE OPTICAL SOCIETY OF AMERICA B-OPTICAL PHYSICS LA English DT Article ID UP-CONVERSION; ENERGY-TRANSFER; FLUORIDE GLASS; IONS; PHOSPHORS; STATE; TM3+ AB We discuss the upconversion luminescence efficiencies of phosphors that generate red, green, and blue light. The phosphors studied are single crystals and powders codoped with Er3+ and Yb3+ and with Tm3- and Yb3+. The Yb ions are pumped near 980 nm; transfers of two or three quanta to the codoped rare-earth ion generate visible luminescence. The main contribution is the quantitative measurement of this upconversion efficiency, based on the use of a calibrated integrating sphere, determination of the fraction of pump light absorbed, and careful control of the pump-laser-beam profile. The green phosphors are the most efficient, yielding efficiency values as high as 4%, with the red and blue materials giving 1%-2%. Saturation was observed in all cases, suggesting that populations of upconversion steps of the ions are maximized at higher power. Quasi-cw modeling of the intensity-dependent upconversion efficiency was attempted; input data included level lifetimes, transition cross sections, and cross-relaxation-rate coefficients. The saturation of the Yb,Er:fluoride media is explained by the pumping of Er3+ ions into a bottleneck (long-lived state), that is, the I-4(13/2) metastable level, making them unavailable for further excitation transfer. (C) 1998 Optical Society of America. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. Gemfire Corp, Palo Alto, CA 94303 USA. RP Page, RH (reprint author), Univ Calif Lawrence Livermore Natl Lab, POB 808,Mailcode L-441, Livermore, CA 94550 USA. NR 33 TC 192 Z9 195 U1 16 U2 80 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA SN 0740-3224 J9 J OPT SOC AM B JI J. Opt. Soc. Am. B-Opt. Phys. PD MAR PY 1998 VL 15 IS 3 BP 996 EP 1008 DI 10.1364/JOSAB.15.000996 PG 13 WC Optics SC Optics GA ZA564 UT WOS:000072377200008 ER PT J AU Sugio, K Shimomura, Y de la Rubia, TD AF Sugio, K Shimomura, Y de la Rubia, TD TI Computer simulation of displacement damage cascade formation near sigma 5 twist boundary in silver SO JOURNAL OF THE PHYSICAL SOCIETY OF JAPAN LA English DT Article DE interstitial atom; damage cascade; sigma 5 boundary; computer simulation; segregation ID EMBEDDED-ATOM-METHOD; METALS; DEFECTS; ALLOYS AB A computer simulation of molecular dynamics is carried out to study the effects of a sigma 5 twist boundary on the formation of displacement damage cascades in silver. When a displacement damage cascade forms near the boundary, interstitial atoms are attracted and segregate on the boundary. The number of Frenkel defects after the formation of damage cascade near the boundary is more than that in a perfect crystal. The segregation of interstitial atoms is due to the interaction with the boundary through the strain field. The movement of interstitial clusters in a strain field is due to a (110) crowdion migration. The larger interstitial clusters are attracted to the boundary at the larger separation. When a damage cascade forms on the boundary, the crystal structure of sigma 5 boundary is modified during the solidification of its molten core, The segregation of interstitial atoms on stacking fault and tn in boundary on the formation of damage cascade was also studied. The segregation of interstitial to these defect planes during the formation of damage cascade was not observed. The preferential segregation of interstitial and vacancy on these planes is due to a strong trapping of point defects on these planes. C1 Hiroshima Univ, Fac Engn, Higashihiroshima 739, Japan. Univ Calif Lawrence Livermore Natl Lab, Chem & Mat Sci Directorate, Div Mat Sci & Technol, Livermore, CA 94550 USA. RP Sugio, K (reprint author), Hiroshima Univ, Fac Engn, 1-4-1 Kagamiyama, Higashihiroshima 739, Japan. RI Sugio, Kenjiro/D-7485-2011 NR 14 TC 17 Z9 19 U1 2 U2 6 PU PHYSICAL SOC JAPAN PI TOKYO PA YUSHIMA URBAN BUILDING 5F, 2-31-22 YUSHIMA, BUNKYO-KU, TOKYO, 113-0034, JAPAN SN 0031-9015 J9 J PHYS SOC JPN JI J. Phys. Soc. Jpn. PD MAR PY 1998 VL 67 IS 3 BP 882 EP 889 DI 10.1143/JPSJ.67.882 PG 8 WC Physics, Multidisciplinary SC Physics GA ZF775 UT WOS:000072932000032 ER PT J AU Hale, DL Swank, WD Haggard, DC AF Hale, DL Swank, WD Haggard, DC TI In-flight particle measurements of twin wire electric arc sprayed aluminum SO JOURNAL OF THERMAL SPRAY TECHNOLOGY LA English DT Article DE aluminum atomization; inflight particle diagnostics; inflight particle pyrometry; laser Doppler velocimeter; twin-wire electric arc ID DISTRIBUTIONS; SIZE AB A real-time, nonintrusive measurement technique was successfully applied to a Tafa Model 9000 (TAFA Incorporated, Concord, NH) twin wire electric arc thermal spray system to simultaneously measure particle size, velocity, and temperature within the spray plume. Aluminum wire was sprayed with the current varied from 100 to 300 amp, and the gun pressure (air flowrate) varied from 40 to 75 psia, For all cases, the average sizes of the molten aluminum particles along the spray centerline range from 33 to 53 mu m. The particles accelerate to peak velocities between 130 and 190 m/s, then decelerate slightly as they travel downstream. The average centerline particle temperature ranges from 2004 to 2056 degrees C, and the temperature profile remains fairly net throughout transport to the substrate. A stagnation pressure probe was used to quantify the gas flow regime in the unladen jet. The wires were found to have a pronounced effect on the flow, resulting in a complex three dimensional flowfield with mixed regions of subsonic and supersonic flow. C1 Lockheed Martin Idaho Technol Co, Idaho Natl Engn & Environm Lab, Idaho Falls, ID 83415 USA. RI Guillen, Donna/B-9681-2017 OI Guillen, Donna/0000-0002-7718-4608 NR 11 TC 14 Z9 17 U1 0 U2 2 PU ASM INTERNATIONAL PI MATERIALS PARK PA SUBSCRIPTIONS SPECIALIST CUSTOMER SERVICE, MATERIALS PARK, OH 44073-0002 USA SN 1059-9630 J9 J THERM SPRAY TECHN JI J. Therm. Spray Technol. PD MAR PY 1998 VL 7 IS 1 BP 58 EP 63 DI 10.1007/s11666-006-5004-8 PG 6 WC Materials Science, Coatings & Films SC Materials Science GA ZB684 UT WOS:000072497200034 ER PT J AU Hassan, B Lopez, AR Oberkampf, WL AF Hassan, B Lopez, AR Oberkampf, WL TI Computational analysis of a three-dimensional high-velocity oxygen fuel (HVOF) thermal spray torch SO JOURNAL OF THERMAL SPRAY TECHNOLOGY LA English DT Article DE computational fluid dynamics; gas dynamics; HVOF AB An analysis of a high-velocity oxygen fuel thermal spray torch is presented using computational fluid dynamics (CFD). Three-dimensional CFD results are presented for a curved aircap used for coating interior surfaces such as engine cylinder bores. The device analyzed is similar to the Metco diamond jet rotating wire torch, but wire feed is not simulated. The feed gases are injected through an axisymmetric nozzle into the curved aircap. Argon is injected through the center of the nozzle. Premixed propylene and oxygen are introduced from an annulus in the nozzle, while cooling air is injected between the nozzle and the interior wall of the aircap. The combustion process is modeled assuming instantaneous chemistry. A standard, two-equation, k-epsilon turbulence model is employed for the turbulent flow field. An implicit, iterative, finite volume numerical technique is used to solve the coupled conservation of mass, momentum, and energy equations for the gas in a sequential manner. Computed flow fields inside and outside the aircap are presented and discussed. C1 Sandia Natl Labs, Aerosci & Compressible Fluid Mech Dept, Albuquerque, NM 87185 USA. NR 13 TC 22 Z9 22 U1 0 U2 6 PU ASM INTERNATIONAL PI MATERIALS PARK PA SUBSCRIPTIONS SPECIALIST CUSTOMER SERVICE, MATERIALS PARK, OH 44073-0002 USA SN 1059-9630 J9 J THERM SPRAY TECHN JI J. Therm. Spray Technol. PD MAR PY 1998 VL 7 IS 1 BP 71 EP 77 DI 10.1007/s11666-006-5006-6 PG 7 WC Materials Science, Coatings & Films SC Materials Science GA ZB684 UT WOS:000072497200036 ER PT J AU Meeks, E Larson, RS Ho, P Apblett, C Han, SM Edelberg, E Aydil, ES AF Meeks, E Larson, RS Ho, P Apblett, C Han, SM Edelberg, E Aydil, ES TI Modeling of SiO2 deposition in high density plasma reactors and comparisons of model predictions with experimental measurements SO JOURNAL OF VACUUM SCIENCE & TECHNOLOGY A-VACUUM SURFACES AND FILMS LA English DT Article ID CHEMICAL-VAPOR-DEPOSITION; COLLISION CROSS-SECTIONS; ELECTRON SWARM PARAMETERS; GAS-PHASE; RATE CONSTANTS; ATOMIC OXYGEN; SURFACE-REACTIONS; SILICON DIOXIDE; SILANE; CHEMISTRY AB High-density-plasma deposition of SiO2 is an important process in integrated circuit manufacturing. A list of gas-phase and surface reactions has been compiled for modeling plasma-enhanced chemical vapor deposition of SiO2 from SiH4, O-2, and Ar gas mixtures in high-density-plasma reactors. The gas-phase reactions include electron impact. neutral-neutral, ion-ion, and ion-neutral reactions. The surface reactions and deposition mechanism is based on insights gained from attenuated total reflection Fourier transform infrared spectroscopy experiments and includes radical adsorption onto the SiO2 surface, ion-enhanced desorption from the surface layer, radical abstractions, as well as direct ion-energy-dependent sputtering of the oxide film. A well-mixed reactor model that consists of mass and energy conservation equations averaged across the reactor volume was used to model three different kinds of high-density plasma deposition chambers. Experimental measurements of total ion densities, relative radical densities, and net deposition rate. as functions of plasma operating conditions, have been compared to model predictions. The results show good quantitative agreement between model predictions and experimental measurements. The compiled reaction set and surface reaction network description was thus validated and can be employed in more sophisticated two-or three-dimensional plasma simulations. (C) 1998 American Vacuum Society. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. Sandia Natl Labs, Livermore, CA 94551 USA. Univ Calif Santa Barbara, Dept Chem Engn, Santa Barbara, CA 93106 USA. RP Aydil, ES (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. EM Aydil@engineering.ucsb.edu OI Aydil, Eray/0000-0002-8377-9480 NR 86 TC 83 Z9 83 U1 3 U2 16 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 MAR-APR PY 1998 VL 16 IS 2 BP 544 EP 563 DI 10.1116/1.581096 PG 20 WC Materials Science, Coatings & Films; Physics, Applied SC Materials Science; Physics GA ZC509 UT WOS:000072587200024 ER PT J AU Dudney, NJ AF Dudney, NJ TI Radio frequency magnetron sputter deposition of CaF2 films SO JOURNAL OF VACUUM SCIENCE & TECHNOLOGY A-VACUUM SURFACES AND FILMS LA English DT Article ID FLUORIDE THIN-FILMS; CALCIUM-FLUORIDE; NEGATIVE-IONS; GROWTH; SI(111); EROSION AB Calcium fluoride films have been deposited onto unheated (<100 degrees C) substrates by low power rf magnetron sputtering of CaF2 targets using Ar and Ne process gases at pressures of 0.5-2.7 Pa, biased and floating substrate potentials, and various geometries of the substrate with respect to the source. The thickness and composition of the films are very sensitive to resputtering of the growing film. Uniform and stoichiometric films were most readily obtained on off-axis substrates using two sputter sources oriented with the targets facing each other. The films were found to be crystalline, have a fine textured microstructure, and to be transparent and highly resistive. (C) 1998 American Vacuum Society. C1 Oak Ridge Natl Lab, Div Solid State, Oak Ridge, TN 37831 USA. RP Dudney, NJ (reprint author), Oak Ridge Natl Lab, Div Solid State, POB 2008, Oak Ridge, TN 37831 USA. RI Dudney, Nancy/I-6361-2016 OI Dudney, Nancy/0000-0001-7729-6178 NR 28 TC 5 Z9 5 U1 3 U2 9 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 MAR-APR PY 1998 VL 16 IS 2 BP 615 EP 623 DI 10.1116/1.581092 PG 9 WC Materials Science, Coatings & Films; Physics, Applied SC Materials Science; Physics GA ZC509 UT WOS:000072587200033 ER PT J AU Gibson, JK AF Gibson, JK TI Laser ablation and gas-phase reactions of small gold cluster ions, Au-n(+) (1 <= n <= 7) SO JOURNAL OF VACUUM SCIENCE & TECHNOLOGY A-VACUUM SURFACES AND FILMS LA English DT Article ID TRANSITION-METAL ATOMS; AROMATIC-HYDROCARBONS; MASS-SPECTROMETER; CHEMISTRY; COPPER; OXIDE AB The abundance distributions of gold cations, Au-n(+) for 1 less than or equal to n less than or equal to 7, generated by pulsed laser albiation of gold metal were determined by time-of-flight mass spectrometry. The odd-n ions, Au-3(+), Au-6(+), and Au-7(+) were particularly abundant, consistent with previous results understood by rudimentary molecular orbital bonding models. A unique aspect of our experiment was the ability to enhance concentrations of the larger Au-n(+) by sampling slower ions in the tail of the ablation plume; this effect indicates ion formation under quasiequilibrium (high temperature) conditions. The primary goal of this study was to examine gas-phase reactions of Au-n(+) for n=1-7 by injecting a hydrocarbon or halocarbon into the ion trajectory and determining compositions/abundances of the resulting complex ions, Au-n(+)-L, formed by abstraction of a ligand(s) L from the organic molecule(s). Among the more significant products were the carbides AunCc+, for n less than or equal to 7 and c less than or equal to 4. The Au-n(+)-L products and distinctive n-dependent variations in product compositions and abundances are interpreted in the context of organogold bonding and condensed phase gold cluster chemistry. The coherence of the exhibited chemistries demonstrates the value of this approach in examining novel transition metal cluster ion chemistry despite the potential for internal excitation of nascent laser-ablated cluster ions. This approach offers a means to prepare new heteronuclear clusters, including noble metal carbides, which may exhibit unique properties. C1 Oak Ridge Natl Lab, Div Chem & Analyt Sci, Oak Ridge, TN 37831 USA. RP Gibson, JK (reprint author), Oak Ridge Natl Lab, Div Chem & Analyt Sci, Oak Ridge, TN 37831 USA. NR 38 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 0734-2101 J9 J VAC SCI TECHNOL A JI J. Vac. Sci. Technol. A-Vac. Surf. Films PD MAR-APR PY 1998 VL 16 IS 2 BP 653 EP 659 DI 10.1116/1.581099 PG 7 WC Materials Science, Coatings & Films; Physics, Applied SC Materials Science; Physics GA ZC509 UT WOS:000072587200039 ER PT J AU Baer, DR Bomben, KD AF Baer, DR Bomben, KD TI Summary: ASTM guide E 1523 to charge control and charge referencing techniques in x-ray photoelectron spectroscopy SO JOURNAL OF VACUUM SCIENCE & TECHNOLOGY A-VACUUM SURFACES AND FILMS LA English DT Article C1 Pacific NW Natl Lab, Richland, WA 99352 USA. Phys Elect, Eden Prairie, MN 55344 USA. RP Baer, DR (reprint author), Pacific NW Natl Lab, Richland, WA 99352 USA. RI Baer, Donald/J-6191-2013 OI Baer, Donald/0000-0003-0875-5961 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 MAR-APR PY 1998 VL 16 IS 2 BP 754 EP 754 DI 10.1116/1.581055 PG 1 WC Materials Science, Coatings & Films; Physics, Applied SC Materials Science; Physics GA ZC509 UT WOS:000072587200054 ER PT J AU Todd, RJ McIntyre, GT AF Todd, RJ McIntyre, GT TI Bakeable, all metal burst diaphragm for ultrahigh vacuum applications requiring low pressure venting SO JOURNAL OF VACUUM SCIENCE & TECHNOLOGY A-VACUUM SURFACES AND FILMS LA English DT Article AB A bakable, all metal burst diaphragm for low pressure venting is described. The device incorporates a bellows which, under pressure, drives a piece of copper foil into a stationary blade. The spring constant of the bellows allows for a puncturing pressure of 8 psi, while complete rupture occurs at 15 psi. The copper foil can be replaced at minimal cost, and the device can be reliably baked at temperatures up to 300 degrees C. (C) 1998 American Vacuum Society. [S0734-2101(98)02502-0]. C1 Brookhaven Natl Lab, Relativist Heavy Ion Collider Project, Upton, NY 11973 USA. RP Todd, RJ (reprint author), Brookhaven Natl Lab, Relativist Heavy Ion Collider Project, Upton, NY 11973 USA. NR 1 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 0734-2101 J9 J VAC SCI TECHNOL A JI J. Vac. Sci. Technol. A-Vac. Surf. Films PD MAR-APR PY 1998 VL 16 IS 2 BP 767 EP 767 DI 10.1116/1.581100 PG 1 WC Materials Science, Coatings & Films; Physics, Applied SC Materials Science; Physics GA ZC509 UT WOS:000072587200059 ER PT J AU Leitner, T Kumar, S Albert, J AF Leitner, T Kumar, S Albert, J TI Tempo and mode of nucleotide substitution in gag and env gene fragments in human immunodeficiency virus type 1 populations with a known transmission history (vol 71, pg 4761, 1997) SO JOURNAL OF VIROLOGY LA English DT Correction C1 Univ Calif Los Alamos Natl Lab, Grp T 10, Los Alamos, NM 87545 USA. Penn State Univ, Inst Mol Evolut Genet, University Pk, PA 16802 USA. Penn State Univ, Dept Biol, University Pk, PA 16802 USA. Karolinska Inst, Swedish Inst Infect Dis Control, Dept Clin Virol, S-10521 Stockholm, Sweden. RP Leitner, T (reprint author), Univ Calif Los Alamos Natl Lab, Grp T 10, POB 1663, Los Alamos, NM 87545 USA. RI Kumar, Sudhir/F-1411-2011 NR 1 TC 4 Z9 4 U1 0 U2 1 PU AMER SOC MICROBIOLOGY PI WASHINGTON PA 1325 MASSACHUSETTS AVENUE, NW, WASHINGTON, DC 20005-4171 USA SN 0022-538X J9 J VIROL JI J. Virol. PD MAR PY 1998 VL 72 IS 3 BP 2565 EP 2565 PG 1 WC Virology SC Virology GA YX013 UT WOS:000071997600110 ER PT J AU Tuzun, RE Sumpter, BG Noid, DW AF Tuzun, RE Sumpter, BG Noid, DW TI On the correspondence between classical and quantum mechanics in macromolecular systems: Too much classical chaos SO MACROMOLECULAR THEORY AND SIMULATIONS LA English DT Article ID MOLECULAR-DYNAMICS SIMULATIONS; MONTE-CARLO; WAVE-FUNCTIONS; RANDOM-WALK; CHEMISTRY; ENERGY; ALGORITHM AB In a recent study we found the classical dynamics of a polyethylene (PE) chain to exhibit low dimensional chaos at temperatures as low as a few Kelvin. These results strongly suggest that classical molecular dynamic simulations in polymer systems can grossly overestimate vibrational motion, which consequently results in disordered structures. In contrast, quantum mechanical calculations using Internal Coordinate Quantum Monte Carlo (an improved method with an initial conjecture for the correct wave function) indicate that the quantum ground state for a three-dimensional model PE chain is far more rigid than determined from molecular dynamics (MD) simulations, even at energies as low as a small fraction of the ground state energy This result casts uncertainty on the reliability of MD estimates of dynamical or structural quanti ties relevant to the study of some macromolecular systems. C1 Oak Ridge Natl Lab, Div Chem & Analyt Sci, Oak Ridge, TN 37831 USA. RP Tuzun, RE (reprint author), Oak Ridge Natl Lab, Div Chem & Analyt Sci, Oak Ridge, TN 37831 USA. RI Sumpter, Bobby/C-9459-2013 OI Sumpter, Bobby/0000-0001-6341-0355 NR 30 TC 10 Z9 10 U1 0 U2 3 PU WILEY-V C H VERLAG GMBH PI BERLIN PA MUHLENSTRASSE 33-34, D-13187 BERLIN, GERMANY SN 1022-1344 J9 MACROMOL THEOR SIMUL JI Macromol. Theory Simul. PD MAR PY 1998 VL 7 IS 2 BP 203 EP 209 PG 7 WC Polymer Science SC Polymer Science GA ZG473 UT WOS:000073006100002 ER PT J AU Ayers, MR Hunt, AJ AF Ayers, MR Hunt, AJ TI Titanium oxide aerogels prepared from titanium metal and hydrogen peroxide SO MATERIALS LETTERS LA English DT Article DE titanium; peroxide; aerogel ID DEGRADATION; GELS; WATER AB The reaction of hydrogen peroxide with excess titanium metal produces rigid titanium oxide aquagels. Subsequent solvent exchanges with ethanol and carbon dioxide, and supercritical drying produces the corresponding aerogels. The aerogels are translucent yellow in appearance, are amorphous to X-rays, and have a BET surface area of 350 m(2)/g. The empirical formula of the material, as prepared, is TiO3H2.7C0.35. Infrared spectroscopy indicates the presence of peroxide and carbonate groups. The microstructure of the aerogel consists of a network of elongated particles 2-5 nm in diameter and tens of nm in length. Thermal treatment under argon at 473 K causes rapid decomposition of the aerogel, forming a blue-gray powder consisting of a mixture of rutile and anatase with a surface area of 80 m(2)/g. Additional thermal treatment at 973 K under air forms predominantly rutile, with a surface area of 20 m(2)/g. (C) 1998 Elsevier Science B.V. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Environm Energy Technol Div, Berkeley, CA 94720 USA. RP Ayers, MR (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Environm Energy Technol Div, Berkeley, CA 94720 USA. EM ajhunt@lbl.gov NR 21 TC 33 Z9 33 U1 2 U2 19 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0167-577X J9 MATER LETT JI Mater. Lett. PD MAR PY 1998 VL 34 IS 3-6 BP 290 EP 293 DI 10.1016/S0167-577X(97)00181-X PG 4 WC Materials Science, Multidisciplinary; Physics, Applied SC Materials Science; Physics GA ZK188 UT WOS:000073294200036 ER PT J AU Roy, AK Fleming, DL Lum, BY AF Roy, AK Fleming, DL Lum, BY TI Localized corrosion behavior of candidate nuclear waste package container materials (Reprinted from Proceedings of the 5th International Conference on Nuclear Engineering, May 1997) SO MATERIALS PERFORMANCE LA English DT Reprint AB Electrochemical cyclic potentiodynamic polarization experiments were performed on six types of alloys to evaluate their susceptibility to localized corrosion in aqueous environments relevant to the potential underground, high-level nuclear waste repository. The effects of chloride ion (Cl-) concentration, pH, temperature, and electrochemical potential scan rate on the pitting/crevice corrosion behavior of these materials were investigated. The results indicated that alloys 825, G-3, and G-30 suffered from pitting and crevice corrosion in all tested environments. Alloy C-4 showed localized attack in 90 degrees C brines, but alloys C-22 and Ti Grade-12 were immune to localized corrosion under all experimental conditions studied. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. RP Roy, AK (reprint author), Univ Calif Lawrence Livermore Natl Lab, POB 808,M-S L-369, Livermore, CA 94551 USA. NR 4 TC 8 Z9 8 U1 0 U2 1 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 MAR PY 1998 VL 37 IS 3 BP 54 EP 58 PG 5 WC Materials Science, Characterization & Testing SC Materials Science GA ZA586 UT WOS:000072379400018 ER PT J AU Horstemeyer, MF McDowell, DL AF Horstemeyer, MF McDowell, DL TI Modeling effects of dislocation substructure in polycrystal elastoviscoplasticity SO MECHANICS OF MATERIALS LA English DT Article DE dislocation substructure; kinematic hardening; anisotropy; elastoviscoplasticity; geometric necessary boundaries; cell blocks ID PLASTIC-DEFORMATION; SINGLE-CRYSTALS; CELL STRUCTURES; LOCALIZED DEFORMATION; TEXTURE DEVELOPMENT; TORSION; COPPER; STRAIN; ALUMINUM; TENSION AB Microheterogeneity resulting from dislocation substructure evolution is introduced into polycrystal elastoviscoplasticity through a second rank tensorial internal state variable. This evolving tensorial variable operates at the scale of the grain to capture the effects of subgrain scale dislocation substructures. The microheterogeneity resulting fr om dislocation substructure evolution is mapped to each single crystal slip system as kinematic hardening and also affects the higher length scale of intergranular constraints in a self-consistent manner. The anisotropy from the microheterogeneity internal state variable improves the: trends of correlation between polycrystalline calculation macroscale responses (stress-strain curve. texture, and axial stresses developed during fixed-end torsion) and the experimental results. Elastic moduli under finite strains were experimentally measured to corroborate numerical predictions. Calculations with the microheterogeneity internal state variable compared better with the elastic moduli measurements than did the Taylor model. (C) 1998 Elsevier Science Ltd. C1 Sandia Natl Labs, Ctr Mat Sci & Engn, Livermore, CA 94551 USA. Georgia Inst Technol, George W Woodruff Sch Mech Engn, Atlanta, GA 30332 USA. RP Horstemeyer, MF (reprint author), Sandia Natl Labs, Ctr Mat Sci & Engn, POB 969, Livermore, CA 94551 USA. OI Horstemeyer, Mark/0000-0003-4230-0063 NR 75 TC 27 Z9 27 U1 0 U2 5 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0167-6636 J9 MECH MATER JI Mech. Mater. PD MAR PY 1998 VL 27 IS 3 BP 145 EP 163 DI 10.1016/S0167-6636(97)00037-9 PG 19 WC Materials Science, Multidisciplinary; Mechanics SC Materials Science; Mechanics GA ZJ253 UT WOS:000073195500002 ER PT J AU Strom, DJ AF Strom, DJ TI Argument for both motions SO MEDICAL PHYSICS LA English DT Editorial Material C1 Pacific NW Lab, Richland, WA 99352 USA. RP Strom, DJ (reprint author), Pacific NW Lab, POB 999, Richland, WA 99352 USA. NR 10 TC 1 Z9 1 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0094-2405 J9 MED PHYS JI Med. Phys. PD MAR PY 1998 VL 25 IS 3 BP 274 EP 275 PG 2 WC Radiology, Nuclear Medicine & Medical Imaging SC Radiology, Nuclear Medicine & Medical Imaging GA ZC355 UT WOS:000072569500003 ER PT J AU Jensen, JA Chumbley, LS AF Jensen, JA Chumbley, LS TI Processing and mechanical properties of magnesium-lithium composites containing steel fibers SO METALLURGICAL AND MATERIALS TRANSACTIONS A-PHYSICAL METALLURGY AND MATERIALS SCIENCE LA English DT Article ID ROLLED CU-20-PERCENT NB; INTERPHASE BARRIER; STRENGTH; ALLOYS; MICROSTRUCTURE; TITANIUM; YTTRIUM; DRAWN; WIRE AB Deformation-processed metal-metal composites (DMMC) of Mg-Li alloys containing steel reinforcing fibers were prepared by infiltrating a preform of steel wool with the molten matrix. The Li content was varied to control the crystal structure of the matrix; Mg-4 wt pet Li is hexagonal close packed (hcp), while Mg-12 wt pet Li is body-centered cubic (bcc). The low carbon steel used as the reinforcing fiber is essentially bcc. The hcp/bcc and bcc/bcc composites were subsequently deformed by rolling and by extrusion/swaging and mechanically tested to relate the tensile strength of the composites to true deformation strain. The hcp/bcc composites had limited formability at temperatures up to 400 degrees C, while the bcc/bcc composites had excellent formability during sheet rolling at room temperature but limited formability during swaging at room temperature. The tensile strengths of the hcp/bcc composite rod and the bcc/bcc composite sheet and rod increased moderately with deformation, though less than predicted from rule-of-mixtures (ROM) calculations. This article presents the experimental data for these DMMC materials and comments on the possible effect of texture development in the matrix and fiber phases on the deformation characteristics of the composite material. C1 Caterpillar Inc, Peoria, IL 61629 USA. Iowa State Univ Sci & Technol, Dept Mat Sci & Engn, Ames, IA 50011 USA. US DOE, Ames Lab, Ames, IA 50011 USA. RP Jensen, JA (reprint author), Caterpillar Inc, Peoria, IL 61629 USA. NR 47 TC 15 Z9 17 U1 1 U2 6 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 MAR PY 1998 VL 29 IS 3 BP 863 EP 873 DI 10.1007/s11661-998-0277-9 PG 11 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA ZE391 UT WOS:000072787900016 ER PT J AU Taleff, EM Henshall, GA Nieh, TG Lesuer, DR Wadsworth, J AF Taleff, EM Henshall, GA Nieh, TG Lesuer, DR Wadsworth, J TI Warm-temperature tensile ductility in Al-Mg alloys SO METALLURGICAL AND MATERIALS TRANSACTIONS A-PHYSICAL METALLURGY AND MATERIALS SCIENCE LA English DT Article ID SOLID-SOLUTION ALLOYS; STRAIN-RATE SENSITIVITY; VISCOUS GLIDE; DISLOCATION CLIMB; CREEP; ALUMINUM; SUPERPLASTICITY; DEFORMATION; TRANSITION; MECHANISMS AB Several binary and ternary Al alloys containing from 2.8 to 5.5 wt pet Mg were tested in tension at elevated temperatures (200 degrees C to 500 degrees C) over a range of strain rates (10(-4) to 2.0 s(-1)). Tensile ductilities of up to 325 pet were obtained in binary Al-Mg alloys with coarse grains deformed in the solute-drag creep regime. Under test conditions in which solute-drag creep controls deformation, Mg in concentrations from 2.8 to 5.5 wt pet neither affects tensile ductility nor influences strain-rate sensitivity or flow stress significantly. Strength is shown to increase with increasing Mg concentration, however, in the power-law-breakdown regime. The solute-drag creep process, which leads to superplastic-like elongations, is shown to have no observable grain-size dependence in a binary Al-Mg material. Ternary alloying additions of Mn and Zr are shown to decrease the strain-rate sensitivity during solute-drag creep, negatively influencing ductility. An important cause of reduced ductility in the ternary alloys during creep deformation is found to be a transition from necking-controlled failure in the binary alloys to cavitation-controlled failure in the ternary alloys investigated. An increase in ternary element concentration, which can increase the relative volume percentage of proeutectic products, increases cavitation. C1 Univ Texas, Dept Aerosp Engn & Engn Mech, Austin, TX 78712 USA. Hewlett Packard Labs, Palo Alto, CA 94303 USA. Univ Calif Lawrence Livermore Natl Lab, Dept Chem & Mat Sci, Livermore, CA 94550 USA. Univ Calif Lawrence Livermore Natl Lab, Mfg & Mat Engn Div, Livermore, CA 94550 USA. RP Taleff, EM (reprint author), Univ Texas, Dept Aerosp Engn & Engn Mech, Austin, TX 78712 USA. RI Nieh, Tai-Gang/G-5912-2011 OI Nieh, Tai-Gang/0000-0002-2814-3746 NR 51 TC 91 Z9 91 U1 0 U2 8 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 MAR PY 1998 VL 29 IS 3A BP 1081 EP 1091 DI 10.1007/s11661-998-0300-1 PG 11 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA ZG358 UT WOS:000072993600019 ER PT J AU Wolf, SF Lipschutz, ME AF Wolf, SF Lipschutz, ME TI Chemical studies of H chondrites 9: Volatile trace element composition and petrographic classification of equilibrated H chondrites SO METEORITICS & PLANETARY SCIENCE LA English DT Article ID PARENT BODIES; METEORITES; METAMORPHISM; ORIGIN; STONY AB To examine the thermal history of the parent body/bodies of equilibrated H chondrites, we treated data for Il volatile trace elements (Go, Rb, Ag, Se, Cs, Te, Zn, Cd, Bi, Tl, and In in order of putative volatility) in 90 falls: 15 H4; 46 H5, and 29 H6. Using univariate statistical tests, contents of few of these elements differ significantly between any two of these suites. One element, Cs, differs systematically between all three pairs of suites; Co and Tl differ between two pairs of suites. For Co and Cs, contents varied as H4 > H5 > H6; while for Tl, contents varied as H4 < H5 < H6. Using multivariate statistical tests, all three suites can be distinguished compositionally, with trace element contents in the H5 suite being intermediate to those of H4 and H6. Surprisingly, the multivariate distinguishability reflects contents of less volatile Co, Rb, Ag, Se and Cs, and not of highly volatile Te, Zn, Cd, Bi, Tl and In. The compositional trends apparently reflect heterogeneous accretion >600 K, with the suites deriving from a stratified parent body/bodies. C1 Argonne Natl Lab, Div Chem Technol, Argonne, IL 60439 USA. Purdue Univ, Dept Chem, W Lafayette, IN 47907 USA. RP Argonne Natl Lab, Div Chem Technol, 9700 S Cass Ave, Argonne, IL 60439 USA. EM wolf@cmt.anl.gov NR 40 TC 3 Z9 3 U1 0 U2 3 PU WILEY-BLACKWELL PI HOBOKEN PA 111 RIVER ST, HOBOKEN 07030-5774, NJ USA SN 1086-9379 EI 1945-5100 J9 METEORIT PLANET SCI JI Meteorit. Planet. Sci. PD MAR PY 1998 VL 33 IS 2 BP 303 EP 312 PG 10 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA ZF084 UT WOS:000072861000014 ER PT J AU Balkwill, DL Murphy, EM Fair, DM Ringelberg, DB White, DC AF Balkwill, DL Murphy, EM Fair, DM Ringelberg, DB White, DC TI Microbial communities in high and low recharge environments: Implications for microbial transport in the vadose zone SO MICROBIAL ECOLOGY LA English DT Article ID PSEUDOMONAS-FLUORESCENS; SUBSURFACE BACTERIA; CHLORINATED ALIPHATICS; INSITU BIORESTORATION; MODEL SIMULATIONS; ESCHERICHIA-COLI; BEREA SANDSTONE; SOIL PROPERTIES; FATTY-ACIDS; MOVEMENT AB Microbial communities along vertical transects in the unsaturated zone were evaluated at five sites in the Pasco Basin, in southeastern Washington State. Sites with contrasting recharge rates were chosen to maximize or minimize the potential for microbial transport. Pore water ages along the vertical transects were established using natural chloride tracers, and ranged from modern to either similar to 15,000 yBP (years before present) or similar to 30,000 yBP at the two low-recharge sites. Unsaturated flow processes were short-circuited by preferential flow at two of the three high-recharge sites, resulting in rapid movement of water through the vertical transects. Microbial numbers and biomass, based on plate counts, and phospholipid fatty acid (PLFA) concentrations decreased with depth at all sites. The majority (55-90%) of the culturable chemoheterotrophs recovered from most samples were streptomycete bacteria. 16S rRNA gene sequence and MIDI analyses indicated that 75% of the remaining isolates were Gram-positive bacteria (most likely species of Arthrobacter and Bacillus) 25% were Gram-negative bacteria (probably members of several genera in the alpha- and gamma-Proteobacteria). Comparison of microbial communities at low-recharge sites vs. high-recharge sites, where preferential flow occurs, revealed several differences that might be attributed to vertical transport of microbial cells at the high-recharge sites. Plate counts and PLFA analyses indicated that the proportion of streptomycetes, which were abundant at the surface but present in the subsurface as spores, decreased, or remained constant, with depth at the low-recharge sites, but increased with depth at the high-recharge sites. PLFA analyses also indicated that Gram-negative bacteria displayed increased nutrient stress with depth at the high-recharge sites characterized by preferential flow, but not at the low recharge site. This may be a result of advective transport of microbes to depths where it was difficult for them to compete effectively with the established community. Moreover, PLFA community structure profiles fluctuated considerably with depth at the low-recharge sites, but not at the high-recharge sites. This might be expected if transport were distributing the microbial community along the vertical profile at the high-recharge sites. In contrast to the high-recharge sites at which preferential flow occurs, filtration likely prevented vertical transport of microorganisms at the high-recharge site that was characterized by unsaturated flow. C1 Florida State Univ, Dept Biol Sci, Tallahassee, FL 32306 USA. Pacific NW Natl Lab, Environm & Energy Sci Div, Richland, WA 99352 USA. Univ Tennessee, Ctr Environm Biotechnol, Knoxville, TN 37932 USA. Oak Ridge Natl Lab, Div Environm Sci, Oak Ridge, TN 37831 USA. RP Balkwill, DL (reprint author), Florida State Univ, Dept Biol Sci, B-157, Tallahassee, FL 32306 USA. EM balkwill@bio.fsu.edu NR 69 TC 47 Z9 51 U1 1 U2 10 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 USA SN 0095-3628 J9 MICROBIAL ECOL JI Microb. Ecol. PD MAR-APR PY 1998 VL 35 IS 2 BP 156 EP 171 DI 10.1007/s002489900070 PG 16 WC Ecology; Marine & Freshwater Biology; Microbiology SC Environmental Sciences & Ecology; Marine & Freshwater Biology; Microbiology GA ZY884 UT WOS:000074671900006 ER PT J AU Lee, Y Gough, RA Kunkel, WB Leung, KN Vujic, J Williams, MD Wutte, D Yang, FL AF Lee, Y Gough, RA Kunkel, WB Leung, KN Vujic, J Williams, MD Wutte, D Yang, FL TI Lifetime enhancement of a multicusp ion source for lithography SO MICROELECTRONIC ENGINEERING LA English DT Article; Proceedings Paper CT Internation Conference on Micro and Nanofabrication CY SEP 15-18, 1998 CL ATHENS, GREECE SP Natl Res Ctr, Inst Microelectr, Greece, European Union, PHANTOMS netw, Greek Secreteriat Res & Technol, Greek Min Culture & Sci, ASM Lithog, Shipley Europe Ltd, Photron, Olymp Airways, Intracom SA, IBM Hellas AB The acceleration system designed by Ion Microfabrication System (IMS) for ion projection lithography (IPL) generates a divergent beam of which only a small portion is employed in the process. Computer simulation shows that by optimizing the accelerator design, the source can he operated with lower discharge power resulting in longer lifetime and lower energy spread. RF induction discharge operation provides long ion source lifetime with energy spread comparable to that of the filament discharge multicusp source when RF modulation in the extraction voltage is eliminated through proper shielding. New antenna designs have been developed which can further extend the lifetime of the RF-driven ion source. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Dept Nucl Engn, Berkeley, CA 94720 USA. Vienna Tech Univ, Inst Allgemeine Phys, A-1040 Vienna, Austria. RP Lee, Y (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Dept Nucl Engn, Berkeley, CA 94720 USA. NR 8 TC 4 Z9 4 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0167-9317 J9 MICROELECTRON ENG JI Microelectron. Eng. PD MAR PY 1998 VL 42 BP 241 EP 244 DI 10.1016/S0167-9317(98)00055-0 PG 4 WC Engineering, Electrical & Electronic; Nanoscience & Nanotechnology; Optics; Physics, Applied SC Engineering; Science & Technology - Other Topics; Optics; Physics GA ZK097 UT WOS:000073284600055 ER PT J AU Eres, G Hui, FYC Thundat, TG Joy, DC AF Eres, G Hui, FYC Thundat, TG Joy, DC TI Nanofabrication by direct epitaxial growth SO MICROELECTRONIC ENGINEERING LA English DT Article; Proceedings Paper CT Internation Conference on Micro and Nanofabrication CY SEP 15-18, 1998 CL ATHENS, GREECE SP Natl Res Ctr, Inst Microelectr, Greece, European Union, PHANTOMS netw, Greek Secreteriat Res & Technol, Greek Min Culture & Sci, ASM Lithog, Shipley Europe Ltd, Photron, Olymp Airways, Intracom SA, IBM Hellas ID SURFACES AB We describe a novel, all dry approach that uses direct epitaxial growth for nanostructure fabrication. The two major requirements for achieving direct epitaxial growth are the ability to generate and to subsequently maintain and control spatial and chemical selectivity in the film growth process. The spatial selectivity is generated by patterning a surface adsorption layer on Si(100) using scanning electron beam lithography. This artificial later al variation in surface reactivity is used as a template in subsequent epitaxy. Selective epitaxial growth on the resulting patterns is achieved by supersonic molecular jet epitaxy. Systematic investigation of the effects of various patterning and growth parameters on spatial and chemical selectivity at a sub-100-nm feature scale using hydrogen terminated and nitrogen terminated growing Si(100) surfaces are presented. C1 Oak Ridge Natl Lab, Div Solid State, Oak Ridge, TN 37831 USA. Oak Ridge Natl Lab, Div Life Sci, Oak Ridge, TN 37831 USA. Univ Tennessee, Knoxville, TN 37996 USA. RP Eres, G (reprint author), Oak Ridge Natl Lab, Div Solid State, POB 2008,Bldg 3150,MS 6056, Oak Ridge, TN 37831 USA. RI Eres, Gyula/C-4656-2017 OI Eres, Gyula/0000-0003-2690-5214 NR 7 TC 5 Z9 5 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0167-9317 J9 MICROELECTRON ENG JI Microelectron. Eng. PD MAR PY 1998 VL 42 BP 519 EP 522 DI 10.1016/S0167-9317(98)00121-X PG 4 WC Engineering, Electrical & Electronic; Nanoscience & Nanotechnology; Optics; Physics, Applied SC Engineering; Science & Technology - Other Topics; Optics; Physics GA ZK097 UT WOS:000073284600121 ER PT J AU Christensen, AN Norby, P Hanson, JC AF Christensen, AN Norby, P Hanson, JC TI Crystallization of microporous aluminophosphates and Me2+-substituted aluminophosphates investigated by in situ synchrotron X-ray powder diffraction SO MICROPOROUS AND MESOPOROUS MATERIALS LA English DT Article DE in situ methods; di-n-propylamine; aluminophosphates; powder diffraction; zeolites ID DI-NORMAL-PROPYLAMINE; MOLECULAR-SIEVES; MAGNESIUM ALUMINOPHOSPHATE; THERMAL-STABILITY; CATALYTIC PROPERTIES; VPI-5; ACIDITY; SAPO-11 AB In situ synchrotron X-ray powder diffraction was used to investigate the crystallization of microporous aluminophosphate and of Mg2+- and Zn2+-substituted aluminophosphates. The gels contained di-n-propylamine as the template, and were heated in quartz glass capillaries at temperatures up to 200 degrees C. The following crystalline reaction products were formed: MgAPO-39, MgAPO-11, ZnAPO-39, ZnAPO-36, APO-39, APO-31, and APO-11. (C) 1998 Elsevier Science B.V. C1 Aarhus Univ, Dept Inorgan Chem, DK-8000 Aarhus C, Denmark. Brookhaven Natl Lab, Dept Chem, Upton, NY 11973 USA. RP Norby, P (reprint author), SUNY Stony Brook, Dept Chem, Stony Brook, NY 11794 USA. RI Hanson, jonathan/E-3517-2010; Norby, Poul/B-9047-2014 OI Norby, Poul/0000-0002-2590-7050 NR 20 TC 10 Z9 10 U1 2 U2 8 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 MAR PY 1998 VL 20 IS 4-6 BP 349 EP 354 PG 6 WC Chemistry, Applied; Chemistry, Physical; Nanoscience & Nanotechnology; Materials Science, Multidisciplinary SC Chemistry; Science & Technology - Other Topics; Materials Science GA 115RJ UT WOS:000075678700010 ER PT J AU Wang, YC Chou, TM Libera, M Voelkl, E Frost, BG AF Wang, YC Chou, TM Libera, M Voelkl, E Frost, BG TI Measurement of polystyrene mean inner potential by transmission electron holography of latex spheres SO MICROSCOPY AND MICROANALYSIS LA English DT Article ID MAGNETIC-FIELDS; MICROSCOPY; CHARGE AB This study describes the use of transmission electron holography to determine the mean inner potential of polystyrene. Spherical nanoparticles of amorphous polystyrene are studied so that the effect of specimen thickness on the phase shift of an incident electron wave can be separated from the intrinsic refractive properties of the specimen, A recursive four-parameter X-squared minimization routine is developed to determine the sphere center, radius, and mean inner potential (Phi(0)) at each pixel in the phase image. Because of the large number of pixels involved, the statistics associated with determining a single Phi(0) value characteristic of a given sphere are guile good. Simulated holograms show that the holographic reconstruction procedure and the chi-squared analysis method are robust. Averaging the Phi(0) data derived from ten phase images from ten different polystyrene spheres gives a value of Phi(0)(PS) = 8.5 V (sigma) = 0.7 V). Specimen charging and electron-beam damage, if present, affect the measurement at a level below the current precision of the experiment. C1 Stevens Inst Technol, Dept Mat Sci & Engn, Hoboken, NJ 07030 USA. Oak Ridge Natl Lab, High Temp Mat Lab, Oak Ridge, TN 37831 USA. Univ Tennessee, Sci & Engn Res Facil, Knoxville, TN 37996 USA. RP Libera, M (reprint author), Stevens Inst Technol, Dept Mat Sci & Engn, Hoboken, NJ 07030 USA. NR 46 TC 26 Z9 26 U1 0 U2 5 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 MAR-APR PY 1998 VL 4 IS 2 BP 146 EP 157 PG 12 WC Materials Science, Multidisciplinary; Microscopy SC Materials Science; Microscopy GA ZQ328 UT WOS:000073847500006 ER PT J AU Kestila, M Lenkkeri, U Mannikko, M Lamerdin, J McCready, P Putaala, H Ruotsalainen, V Morita, T Nissinen, M Herva, R Kashtan, CE Peltonen, L Holmberg, C Olsen, A Tryggvason, K AF Kestila, M Lenkkeri, U Mannikko, M Lamerdin, J McCready, P Putaala, H Ruotsalainen, V Morita, T Nissinen, M Herva, R Kashtan, CE Peltonen, L Holmberg, C Olsen, A Tryggvason, K TI Positionally cloned gene for a novel glomerular protein - nephrin - is mutated in congenital nephrotic syndrome SO MOLECULAR CELL LA English DT Article ID LINKED ALPORT-SYNDROME; COL4A5 COLLAGEN GENE; FINNISH TYPE; BASEMENT-MEMBRANE; DNA-SEQUENCES; MUTATIONS; EXONS; IDENTIFICATION; GLYCOPROTEIN; MANAGEMENT AB Congenital nephrotic syndrome of the Finnish type (NPHS1) is an autosomal-recessive disorder, characterized by massive proteinuria in utero and nephrosis at birth. In this study, the 150 kb critical region of NPHS1 was sequenced, revealing the presence of at least 11 genes, the structures of 5 of which were determined. Four different mutations segregating with the disease were found in one of the genes in NPHS1 patients. The NPHS1 gene product, termed nephrin, is a 1241-residue putative transmembrane protein of the immunoglobulin family of cell adhesion molecules, which by Northern and in situ hybridization was shown to be specifically expressed in renal glomeruli. The results demonstrate a crucial role for this protein in the development or function of the kidney filtration barrier. C1 Univ Oulu, Bioctr, FIN-90570 Oulu, Finland. Univ Oulu, Dept Biochem, FIN-90570 Oulu, Finland. Karolinska Inst, Dept Med Biochem & Biophys, Div Matrix Biol, S-17177 Stockholm, Sweden. Lawrence Livermore Natl Lab, Ctr Human Genome, Livermore, CA 94550 USA. Oulu Univ Hosp, Dept Pathol, FIN-90220 Oulu, Finland. Univ Minnesota, Dept Pediat, Minneapolis, MN 55455 USA. Univ Helsinki, Inst Biomed, Dept Human Mol Genet, FIN-00300 Helsinki, Finland. Natl Publ Hlth Inst, FIN-00300 Helsinki, Finland. Univ Helsinki, Hosp Children & Adolescence, FIN-00290 Helsinki, Finland. RP Tryggvason, K (reprint author), Univ Oulu, Bioctr, FIN-90570 Oulu, Finland. NR 42 TC 1125 Z9 1213 U1 1 U2 21 PU CELL PRESS PI CAMBRIDGE PA 1050 MASSACHUSETTES AVE, CIRCULATION DEPT, CAMBRIDGE, MA 02138 USA SN 1097-2765 J9 MOL CELL JI Mol. Cell. PD MAR PY 1998 VL 1 IS 4 BP 575 EP 582 DI 10.1016/S1097-2765(00)80057-X PG 8 WC Biochemistry & Molecular Biology; Cell Biology SC Biochemistry & Molecular Biology; Cell Biology GA ZG146 UT WOS:000072970700010 PM 9660941 ER PT J AU Gacy, AM Goellner, GM Spiro, C Chen, X Gupta, G Bradbury, EM Dyer, RB Mikesell, MJ Yao, JZ Johnson, AJ Richter, A Melancon, SB McMurray, CT AF Gacy, AM Goellner, GM Spiro, C Chen, X Gupta, G Bradbury, EM Dyer, RB Mikesell, MJ Yao, JZ Johnson, AJ Richter, A Melancon, SB McMurray, CT TI GAA instability in Friedreich's Ataxia shares a common, DNA-directed and intraallelic mechanism with other trinucleotide diseases SO MOLECULAR CELL LA English DT Article ID HUMAN GENETIC-DISEASE; MISMATCH REPAIR; GENERAL-POPULATION; ESCHERICHIA-COLI; TRIPLET REPEAT; MUTATION; SEQUENCE; EXPANSION; REPLICATION; FAMILIES AB We show that GAA instability in Friedreich's Ataxia is a DNA-directed mutation caused by improper DNA structure at the repeat region. Unlike CAG or CGG repeats, which form hairpins, GAA repeats form a YRY triple helix containing non-Watson-Crick pairs. As with hairpins, tripler mediates intergenerational instability in 96% of transmissions. In families with Friedreich's Ataxia, the only recessive trinucleotide disease, GAA instability is not a function of the number of long alleles, ruling out homologous recombination or gene conversion as a major mechanism. The similarity of mutation pattern among triple repeat-related diseases indicates that all trinucleotide instability occurs by a common, intraallelic mechanism that depends on DNA structure. Secondary structure mediates instability by creating strong polymerase pause sites at or within the repeats, facilitating slippage or sister chromatid exchange. C1 Mayo Fdn, Dept Pharmacol, Rochester, MN 55905 USA. Mayo Fdn, Mol Neurosci Program, Rochester, MN 55905 USA. Mayo Fdn, Dept Biochem & Mol Biol, Rochester, MN 55905 USA. Mayo Fdn, Dept Immunol, Rochester, MN 55905 USA. Mayo Grad Sch, Rochester, MN 55905 USA. Univ Calif Los Alamos Natl Lab, Div Life Sci, Los Alamos, NM 87545 USA. Univ Montreal, Hop St Justine, Dept Pediat, Serv Genet Med, Montreal, PQ H3T 1C5, Canada. RP McMurray, CT (reprint author), Mayo Fdn, Dept Pharmacol, Rochester, MN 55905 USA. FU NIDDK NIH HHS [DK 43694-01A2] NR 62 TC 111 Z9 114 U1 0 U2 4 PU CELL PRESS PI CAMBRIDGE PA 1050 MASSACHUSETTES AVE, CIRCULATION DEPT, CAMBRIDGE, MA 02138 USA SN 1097-2765 J9 MOL CELL JI Mol. Cell. PD MAR PY 1998 VL 1 IS 4 BP 583 EP 593 DI 10.1016/S1097-2765(00)80058-1 PG 11 WC Biochemistry & Molecular Biology; Cell Biology SC Biochemistry & Molecular Biology; Cell Biology GA ZG146 UT WOS:000072970700011 PM 9660942 ER PT J AU Mian, IS Moser, MJ AF Mian, IS Moser, MJ TI The Fanconi anemia complementation group A protein contains a peroxidase domain SO MOLECULAR GENETICS AND METABOLISM LA English DT Article DE Fanconi anemia; FAA protein; hidden Markov model; peroxidase; oxidative damage ID HIDDEN MARKOV-MODELS; SECONDARY STRUCTURE; INFORMATION; IDENTIFICATION; SUPERFAMILY; ALIGNMENT; MEMBERS AB Computational analysis of the Fanconi anemia (FA) complementation group A protein suggests that it contains a peroxidase domain. FA proteins may be part of a general mechanism that protects cells from oxidative damage. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Div Life Sci, Berkeley, CA 94720 USA. RP Univ Calif Berkeley, Lawrence Berkeley Lab, Div Life Sci, Mail Stop 29-100,1 Cyclotron Rd, Berkeley, CA 94720 USA. EM SMian@lbl.gov NR 38 TC 16 Z9 16 U1 0 U2 0 PU ACADEMIC PRESS INC ELSEVIER SCIENCE PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 1096-7192 EI 1096-7206 J9 MOL GENET METAB JI Mol. Genet. Metab. PD MAR PY 1998 VL 63 IS 3 BP 230 EP 234 DI 10.1006/mgme.1997.2652 PG 5 WC Endocrinology & Metabolism; Genetics & Heredity; Medicine, Research & Experimental SC Endocrinology & Metabolism; Genetics & Heredity; Research & Experimental Medicine GA ZR390 UT WOS:000073970200010 PM 9608546 ER PT J AU Sohlberg, K Sumpter, BG Tuzun, RE Noid, DW AF Sohlberg, K Sumpter, BG Tuzun, RE Noid, DW TI Continuum methods of mechanics as a simplified approach to structural engineering of nanostructures SO NANOTECHNOLOGY LA English DT Article ID VIBRATIONAL-SPECTRA; DYNAMICS; TRAJECTORIES AB Recent studies of potential components for nanomachines reveal that for a wide variety of structures. the rigidity of the structure is a key element in its proper performance. Vibrational analysis is an ideal way to study structural rigidity, but standard methods of molecular Vibrational analysis are computationally prohibitive for nanostructures with large numbers of atoms. Herein, the Vibration of nanotubes is used to demonstrate that continuum methods of Vibrational analysis have potential utility in the engineering of nanostructures. C1 Oak Ridge Natl Lab, Div Chem & Analyt Sci, Oak Ridge, TN 37831 USA. RP Sohlberg, K (reprint author), Oak Ridge Natl Lab, Div Chem & Analyt Sci, 4500N MS6197, Oak Ridge, TN 37831 USA. RI Sumpter, Bobby/C-9459-2013 OI Sumpter, Bobby/0000-0001-6341-0355 NR 23 TC 65 Z9 67 U1 1 U2 3 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0957-4484 J9 NANOTECHNOLOGY JI Nanotechnology PD MAR PY 1998 VL 9 IS 1 BP 30 EP 36 DI 10.1088/0957-4484/9/1/004 PG 7 WC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Physics, Applied SC Science & Technology - Other Topics; Materials Science; Physics GA ZP225 UT WOS:000073730500004 ER PT J AU Tuzun, RE Sohlberg, K Noid, DW Sumpter, BG AF Tuzun, RE Sohlberg, K Noid, DW Sumpter, BG TI Docking envelopes for the assembly of molecular bearings SO NANOTECHNOLOGY LA English DT Article ID DYNAMICS SIMULATIONS AB To design a process for the assembly or self-assembly of a nanomachine requires knowing the degree of spatial control needed to put the components together. A useful starting point in this area of study is the concept of a docking envelope, which is a continuous region of initial condition parameter space for which two structures will dock. In this paper docking envelopes, determined from molecular dynamics simulation, are presented for the assembly of a molecular bearing consisting of two concentric carbon nanotubes. in-the beginning of each simulation the outer nanotube (sleeve) is held in place and the inner nanotube (shaft) starts far away from, but is given an initial velocity toward, the sleeve. The docking envelope in this case is delineated by the initial offset from a coaxial geometry. In order to address recent concerns about the effects of zero-point energy leakage and chaos in classical simulations of nanomachine components, docking envelopes from two types of simulations are presented: fully atomistic (all degrees of freedom included) and rigid body (each nanotube rigid but shaft allowed to rotate and translate). C1 Oak Ridge Natl Lab, Div Chem & Analyt Sci, Oak Ridge, TN 37831 USA. RP Tuzun, RE (reprint author), Oak Ridge Natl Lab, Div Chem & Analyt Sci, Oak Ridge, TN 37831 USA. RI Sumpter, Bobby/C-9459-2013 OI Sumpter, Bobby/0000-0001-6341-0355 NR 30 TC 23 Z9 23 U1 1 U2 1 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0957-4484 J9 NANOTECHNOLOGY JI Nanotechnology PD MAR PY 1998 VL 9 IS 1 BP 37 EP 48 DI 10.1088/0957-4484/9/1/005 PG 12 WC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Physics, Applied SC Science & Technology - Other Topics; Materials Science; Physics GA ZP225 UT WOS:000073730500005 ER PT J AU Beiu, V AF Beiu, V TI On the circuit and VLSI complexity of threshold gate COMPARISON SO NEUROCOMPUTING LA English DT Article DE area-time complexity; circuit complexity; COMPARISON; threshold gates/circuits; VLSI complexity ID NEURAL NETWORKS; COMPUTATION; TRADEOFFS AB The paper overviews recent developments concerning optimal (from the point of view of size and depth) implementations of COMPARISON using threshold gates. We detail a class of solutions which also covers other particular solutions, and spans from constant to logarithmic depths. These theoretical circuit complexity results are extended to VLSI complexity ones, having practical applications to: (i) hardware implementations of integrated circuits; (ii) VLSI-friendly neural learning algorithms (i.e., constructive, or ontogenetic algorithms); and (iii) synthesis methods for mixed digital/analog technologies. In order to estimate the area (A) and the delay (T), as well as the classical AT(2), we make use of the following "cost functions": (i) the connectivity (i.e., sum of fan-ins) and the number-of-bits for representing the weights and thresholds are used as closer approximations of the area; while (ii) the fan-ins and the length of the wires are used for closer estimates of the delay. Such approximations will allow us to compare several solutions - which present very interesting fan-in-dependent depth-size and area-delay tradeoffs - with respect to AT(2). (C) 1998 Elsevier Science B.V. All rights reserved. C1 Univ Calif Los Alamos Natl Lab, Div NIS 1, Los Alamos, NM 87545 USA. RP Beiu, V (reprint author), Univ Calif Los Alamos Natl Lab, Div NIS 1, MS D466, Los Alamos, NM 87545 USA. RI Beiu, Valeriu/F-7799-2015 OI Beiu, Valeriu/0000-0001-8185-956X NR 64 TC 13 Z9 13 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0925-2312 J9 NEUROCOMPUTING JI Neurocomputing PD MAR PY 1998 VL 19 IS 1-3 BP 77 EP 98 DI 10.1016/S0925-2312(97)00099-4 PG 22 WC Computer Science, Artificial Intelligence SC Computer Science GA ZK800 UT WOS:000073365000008 ER PT J AU Elowitz, EH Bergland, RM Coderre, JA Joel, DD Chadha, M Chanana, AD AF Elowitz, EH Bergland, RM Coderre, JA Joel, DD Chadha, M Chanana, AD TI Biodistribution of p-boronophenylalanine in patients with glioblastoma multiforme for use in boron neutron capture therapy SO NEUROSURGERY LA English DT Article DE boron neutron capture therapy; boronophenylalanine; glioblastoma multiforme ID MALIGNANT-MELANOMA; COMPLEX-FORMATION; MONOSACCHARIDES; TUMORS; MODEL AB OBJECTIVE: The success of boron neutron capture therapy depends on the safety and specificity of the boron delivery agent. As a preface to clinical boron neutron capture therapy of glioblastoma multiforme, a biodistribution study of intravenous p-boronophenylalanine (BPA) in patients undergoing craniotomy for resection of glioblastoma was performed. METHODS: Varying doses of intravenously administered BPA-fructose (130-250 mg BPA per kilogram of body weight) were given to patients 2 to 3 hours prior to the start of craniotomy for either suspected or known glioblastoma multiforme. Blood samples were collected over a 48-hour period for boron assay. At surgery, multiple samples of tumor, brain, and scalp were obtained for boron and histological analysis. RESULTS: Seventeen patients were studied; all but one had glioblastoma multiforme. No adverse effects from the BPA infusions were noted. The boron concentration in the blood reached a maximum at the end of the EPA infusion and was proportional to the administered dose of EPA. Normal brain concentrations of boron generally were equal to or less than that in blood. Tumor-blood boron ratios were highly variable: 1.6 +/- 0.8 (mean +/- standard deviation; n = 187; range, 0.3-3.5). The observed heterogeneity of BPA uptake in glioblastoma samples appears to correlate with the degree of cellularity observed on histological examination. CONCLUSION: Intravenous BPA administration up to a dose of 250 mg/kg is safe and well tolerated. EPA uptake in surgical samples of glioblastoma tissue is variable and may depend on the fraction of viable tumor cells in the individual sample. Further clinical studies using BPA as a boron delivery agent for boron neutron capture therapy of glioblastoma multiforme appear warranted. C1 Beth Israel Med Ctr, Div N, Dept Neurosurg, New York, NY 10128 USA. Beth Israel Med Ctr, Dept Radiat Oncol, New York, NY 10128 USA. Brookhaven Natl Lab, Dept Med, Upton, NY 11973 USA. RP Elowitz, EH (reprint author), Beth Israel Med Ctr, Div N, Dept Neurosurg, 170 E End Ave, New York, NY 10128 USA. NR 22 TC 63 Z9 65 U1 0 U2 0 PU LIPPINCOTT WILLIAMS & WILKINS PI PHILADELPHIA PA 227 EAST WASHINGTON SQ, PHILADELPHIA, PA 19106 USA SN 0148-396X J9 NEUROSURGERY JI Neurosurgery PD MAR PY 1998 VL 42 IS 3 BP 463 EP 468 DI 10.1097/00006123-199803000-00004 PG 6 WC Clinical Neurology; Surgery SC Neurosciences & Neurology; Surgery GA ZC008 UT WOS:000072530300016 PM 9526978 ER PT J AU Kaper, HG Takac, P AF Kaper, HG Takac, P TI Ginzburg-Landau dynamics with a time-dependent magnetic field SO NONLINEARITY LA English DT Article ID SUPERCONDUCTIVITY; EQUATIONS AB The time-dependent Ginzburg-Landau equations of superconductivity define a dynamical process when the applied magnetic field varies with time. Sufficient conditions (in terms of the time rate of change of the applied field) are given that, if satisfied, guarantee that this dynamical process is asymptotically autonomous. As time goes to infinity, the dynamical process asymptotically approaches a dynamical system whose attractor coincides with the omega-limit set of the dynamical process. C1 Argonne Natl Lab, Div Math & Comp Sci, Argonne, IL 60439 USA. Univ Rostock, Fachbereich Math, D-18055 Rostock, Germany. RP Kaper, HG (reprint author), Argonne Natl Lab, Div Math & Comp Sci, Argonne, IL 60439 USA. NR 11 TC 11 Z9 11 U1 0 U2 0 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0951-7715 J9 NONLINEARITY JI Nonlinearity PD MAR PY 1998 VL 11 IS 2 BP 291 EP 305 DI 10.1088/0951-7715/11/2/006 PG 15 WC Mathematics, Applied; Physics, Mathematical SC Mathematics; Physics GA ZC111 UT WOS:000072541000006 ER PT J AU Jaeger, EF Berry, LA Batchelor, DB AF Jaeger, EF Berry, LA Batchelor, DB TI Reduced order methods for full wave ICRF calculations in tokamaks SO NUCLEAR FUSION LA English DT Article ID RAY-TRACING ANALYSIS; CURRENT DRIVE; GLOBAL WAVES; PLASMAS; FIELDS AB Reduced order methods have been used extensively to eliminate ion Bernstein waves (IBWs) from full wave calculations in the ion cyclotron range of frequencies (ICRF). These reduced order methods replace higher order derivatives in the finite Larmor radius (FLR) expansion of the plasma current with algebraic terms depending on the local perpendicular wavenumber k(perpendicular to) determined from the fourth order plasma dispersion relation. However, the dispersion relation determines only the magnitude of k(perpendicular to), not the direction. If k(perpendicular to) is assumed to be perpendicular to the flux surface, energy conservation is violated near the magnetic axis. One method of dealing with this problem is to solve algebraically for the parallel electric field E-parallel to, in which case the direction of k(perpendicular to) drops out of the problem completely. Another method, which allows for the complete differential solution of E-parallel to, assumes a direction for k(perpendicular to). Both methods are limited by assumptions. A better approach is to apply the reduced order algorithm to the ion FLR current alone, while treating the electron current differentially. Since the direction of k(perpendicular to) enters only through electron terms, this method resolves the ambiguity in the direction of k(perpendicular to) while still suppressing the IBW, which originates in the ion current. Comparison with the simpler models suggests that it is necessary to include the differential electron current for an accurate description of direct electron heating and fast wave current drive near the ion second harmonic. C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Jaeger, EF (reprint author), Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. NR 24 TC 2 Z9 2 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 MAR PY 1998 VL 38 IS 3 BP 437 EP 447 DI 10.1088/0029-5515/38/3/310 PG 11 WC Physics, Fluids & Plasmas SC Physics GA ZK796 UT WOS:000073364500010 ER PT J AU Pomphrey, N Bialek, JM Park, W AF Pomphrey, N Bialek, JM Park, W TI Modelling of the toroidal asymmetry of poloidal halo currents in conducting structures SO NUCLEAR FUSION LA English DT Article ID VACUUM VESSEL; DISRUPTIONS; SIMULATION AB During plasma disruptions, substantial toroidal and poloidal eddy currents are generated in the vacuum vessel and other plasma facing conducting structures. Eddy currents that conduct charge through paths which close through the plasma periphery are called halo currents, and these can be of substantial magnitude. Of particular concern for tokamak design and operation is the observed toroidal asymmetry of the halo current distribution: such an asymmetric distribution leads to problematic non-uniform forces on the conducting structures. The premise is adopted that the source of toroidal asymmetry is the plasma deformation resulting from the non-linear external kink instability that develops during the current quench phase of a disruption. A simple model is presented of the kinked plasma that allows an analytic calculation of the dependence of the toroidal peaking factor (TPF) on the ratio of the halo current to the total toroidal plasma current, I-h/I-p. Expressions for the TPF as a function of I-h/I-p are derived for m/n = 2/1 and m/n = 1/1 helical instabilities. The expressions depend on a single parameter, which measures the amplitude of the saturated state of the kink instability. A comparison with disruption data from experiments shows good agreement. Numerical experiments that simulate non-linear external kinks provide guidance on the values expected for the saturated amplitude. It is proposed that a simple plasma halo model is adequate for assessing the engineering impact of asymmetric halo currents, since the force distribution on the conducting structures depends mainly on the 'resistive distribution' of the eddy currents. A brief description is given of an electromagnetics code that calculates the time development of eddy currents in conducting structures, and the code is applied to two halo current disruption scenarios. These are used to emphasize the importance of having an accurate eddy current calculation to correctly estimate the engineering impact of tokamak disruptions. C1 Princeton Univ, Princeton Plasma Phys Lab, Princeton, NJ 08543 USA. RP Pomphrey, N (reprint author), Princeton Univ, Princeton Plasma Phys Lab, POB 451, Princeton, NJ 08543 USA. RI pomphrey, neil/G-4405-2010 NR 17 TC 35 Z9 35 U1 1 U2 4 PU INT ATOMIC ENERGY AGENCY PI VIENNA PA WAGRAMERSTRASSE 5, PO BOX 100, A-1400 VIENNA, AUSTRIA SN 0029-5515 J9 NUCL FUSION JI Nucl. Fusion PD MAR PY 1998 VL 38 IS 3 BP 449 EP 466 DI 10.1088/0029-5515/38/3/311 PG 18 WC Physics, Fluids & Plasmas SC Physics GA ZK796 UT WOS:000073364500011 ER PT J AU Eden, T Madey, R Markowitz, P Rutt, PM Anderson, BD Baldwin, AR Barkhuff, D Beard, KB Bertozzi, W Cameron, JM Chang, CC Dodson, GW Dow, K Farkhondeh, M Finn, JM Flanders, BS Hyde-Wright, C Jiang, WD Keane, D Kelly, JJ Korsch, W Kowalski, S Lourie, R McIntyre, J Manley, DM Mougey, J Ni, B Payerle, T Pella, PJ Reichelt, T Spraker, M Tieger, D Turchinetz, W Ulmer, PE Van Verst, S Watson, JW Weinstein, LB Whitney, RR Zhang, WM AF Eden, T Madey, R Markowitz, P Rutt, PM Anderson, BD Baldwin, AR Barkhuff, D Beard, KB Bertozzi, W Cameron, JM Chang, CC Dodson, GW Dow, K Farkhondeh, M Finn, JM Flanders, BS Hyde-Wright, C Jiang, WD Keane, D Kelly, JJ Korsch, W Kowalski, S Lourie, R McIntyre, J Manley, DM Mougey, J Ni, B Payerle, T Pella, PJ Reichelt, T Spraker, M Tieger, D Turchinetz, W Ulmer, PE Van Verst, S Watson, JW Weinstein, LB Whitney, RR Zhang, WM TI Neutron detection efficiency for the measurement of the H-2(e,e ' n) H-1 cross section SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article DE neutron detection efficiency; associated-particle technique ID ELECTRIC FORM-FACTOR; SYSTEM AB We report a measurement of the neutron detection efficiency for an array of neutron detectors behind a lead-steel wall consisting of 10.16 cm thick lead bricks sandwiched between 3.18 cm steel plates. The neutron detection efficiency epsilon was obtained from the ratio of coincidence to single-arm proton cross sections using the gamma + H-2(1) --> p + n reaction. Knowledge of the neutron detection efficiency was necessary to extract the cross section for the exclusive H-2(e,e'n)H-1 reaction, which we used to obtain the elastic magnetic form factor G(M)(n) of the neutron. The measurements for three different neutron energies were carried out at the MIT-Bates Linear Accelerator Center with an incident electron beam energy of 254 MeV. (C) 1998 Elsevier Science B.V. All rights reserved. C1 Kent State Univ, Kent, OH 44242 USA. Hampton Univ, Hampton, VA 23668 USA. Coll William & Mary, Williamsburg, VA 23185 USA. Univ Virginia, Charlottesville, VA 22904 USA. MIT, Cambridge, MA 02139 USA. Indiana Univ, Cyclotron Facil, Bloomington, IN 47408 USA. Univ Maryland, College Pk, MD 20742 USA. American Univ, Washington, DC 20016 USA. Univ Washington, Seattle, WA 98195 USA. Gettysburg Coll, Gettysburg, PA 17325 USA. Univ Bonn, Inst Phys, D-53115 Bonn, Germany. Thomas Jefferson Natl Accelerator Facil, Newport News, VA 23606 USA. RP Eden, T (reprint author), Thomas Jefferson Natl Accelerator Facil, MS28F,12000 Jefferson Ave, Newport News, VA 23606 USA. RI McIntyre, Justin/P-1346-2014 OI McIntyre, Justin/0000-0002-3706-4310 NR 12 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 MAR 1 PY 1998 VL 405 IS 1 BP 60 EP 70 DI 10.1016/S0168-9002(97)01158-3 PG 11 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA ZD608 UT WOS:000072703600008 ER PT J AU Blasdell, RC Simmons, RO AF Blasdell, RC Simmons, RO TI Simulation of the response of the IPNS neutron time-of-flight chopper spectrometers to samples in the Compton limit SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article DE chopper spectrometer; Monte Carlo; instrument simulation; multiple scattering; LRMECS; HRMECS ID MONTE-CARLO CALCULATION; MULTIPLE-SCATTERING; KINETIC-ENERGY; RESOLUTION FUNCTION; LIQUID; ARGON; HE-4 AB We describe the comprehensive biased Monte Carlo code SPEC_SIM used to obtain accurate estimates of instrument response functions for neutron Compton scattering studies of the atomic momentum distribution of noble gas solids and liquids. The code is tailored to simulate epithermal neutron transport in the Intense Pulsed Neutron Source (IPNS) chopper spectrometers. The simulation begins with the neutrons emitted from the face of the moderator. The neutron trajectories are traced through a curved slit Fermi rotor (chopper) and are allowed to scatter multiple times from the sample region which may contain a sample, sample cell, and set of thermal radiation shields in any of a complex set of geometries. The scattered neutrons are tracked to the detector bank where they are again allowed to scatter before being "absorbed" and converted into a time-of-flight (TOF) signal which is histogrammed. A similar simulation code calculates the TOF response of two beam monitors to the incident neutron pulse, including the effects of scattering in the walls of the monitors. All of the scattering in the simulation is treated within a generalization of the impulse approximation. The results of the Monte Carlo simulations compare very favorably with experiments on solid and liquid He, Ar, and Ne. (C) 1998 Published by Elsevier Science B.V. All rights reserved. C1 Univ Illinois, Dept Phys, Urbana, IL 61801 USA. Univ Illinois, Frederick Seitz Mat Res Lab, Urbana, IL 61801 USA. Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. RP Simmons, RO (reprint author), Univ Illinois, Dept Phys, 1110 W Green St, Urbana, IL 61801 USA. EM ros@uiuc.edu NR 41 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 MAR 1 PY 1998 VL 405 IS 1 BP 71 EP 97 DI 10.1016/S0168-9002(97)01212-6 PG 27 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA ZD608 UT WOS:000072703600009 ER PT J AU Baglin, JEE Davis, JC Gabella, P Prozesky, VM Sie, S AF Baglin, JEE Davis, JC Gabella, P Prozesky, VM Sie, S TI Future analytical needs for industry and technology SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS LA English DT Article; Proceedings Paper CT 13th International Conference on Ion Beam Analysis (IBA-13) CY JUL 27-AUG 01, 1997 CL LISBON, PORTUGAL DE future analytical needs; semiconductors; biomedicine; minerals; geoscience; PIXE; AMS; ion microbeams AB This paper summarizes reports and opinions presented during a Roundtable Session of the same title at the 13th International Conference on Ion Beam Analysis, Lisbon, 1997, The evolution of new technologies and new fields of research is creating new demands for advanced materials analysis, often at a level not attainable with current techniques. We therefore explore some opportunities for creative development of new or enhanced ion beam techniques to satisfy major predictable needs of the future. In particular, new analytical applications are discussed for the semiconductor industry. for biomedical research, and for advanced research in minerals and geoscience. (C) 1998 Elsevier Science B.V. C1 IBM Corp, Almaden Res Ctr, San Jose, CA 95120 USA. Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. SEMATECH, SEMI, Austin, TX 78741 USA. Natl Accelerator Ctr, Van de Graaff Grp, ZA-7131 Faure, South Africa. CSIRO Explorat & Min, N Ryde, NSW 2113, Australia. RP Baglin, JEE (reprint author), IBM Corp, Almaden Res Ctr, 650 Harry Rd,K191D1, San Jose, CA 95120 USA. EM baglin@almaden.ibm.com NR 0 TC 1 Z9 1 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-583X J9 NUCL INSTRUM METH B JI Nucl. Instrum. Methods Phys. Res. Sect. B-Beam Interact. Mater. Atoms PD MAR PY 1998 VL 136 BP 35 EP 41 DI 10.1016/S0168-583X(97)00832-X PG 7 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Atomic, Molecular & Chemical; Physics, Nuclear SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA ZW154 UT WOS:000074380400005 ER PT J AU McIntyre, PC Maggiore, CJ Nastasi, M AF McIntyre, PC Maggiore, CJ Nastasi, M TI Interpretation of ion channeling results from epitaxial Pt thin films and Co/Pt multilayers SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS LA English DT Article; Proceedings Paper CT 13th International Conference on Ion Beam Analysis (IBA-13) CY JUL 27-AUG 01, 1997 CL LISBON, PORTUGAL AB Ion channeling was used to characterize the orientation and crystalline quality of very thin (<40 nm) Pt films and Co/Pt multilayers grown epitaxially on (0 0 1) MgO single crystal substrates by electron beam evaporation. Planar channeling measurements were found to be particularly useful for characterizing the film orientation, and for identifying the structure of ultra-thin Co layers in the multilayers. Comparison of ion channeling and transmission electron microscopy (TEM) results points out several potential difficulties in interpreting ion channeling data in these highly mismatched epitaxial systems. (C) 1998 Published by Elsevier Science B.V. C1 Stanford Univ, Dept Mat Sci & Engn, Stanford, CA 94305 USA. Univ Calif Los Alamos Natl Lab, Mat Sci & Technol Div, Los Alamos, NM 87545 USA. RP McIntyre, PC (reprint author), Stanford Univ, Dept Mat Sci & Engn, Stanford, CA 94305 USA. NR 15 TC 0 Z9 0 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-583X J9 NUCL INSTRUM METH B JI Nucl. Instrum. Methods Phys. Res. Sect. B-Beam Interact. Mater. Atoms PD MAR PY 1998 VL 136 BP 214 EP 219 DI 10.1016/S0168-583X(97)00682-4 PG 6 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Atomic, Molecular & Chemical; Physics, Nuclear SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA ZW154 UT WOS:000074380400036 ER PT J AU Cole, DH Shull, KR Rehn, LE Baldo, PM AF Cole, DH Shull, KR Rehn, LE Baldo, PM TI RBS analysis of the diffusion of nano-size spheres in a polymer matrix SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS LA English DT Article; Proceedings Paper CT 13th International Conference on Ion Beam Analysis (IBA-13) CY JUL 27-AUG 01, 1997 CL LISBON, PORTUGAL ID GOLD AB Rutherford Backscattering Spectrometry (RBS) with 1.5 MeV He ions was employed to measure the depth distribution of gold particles sandwiched between two poly (tell-butyl acrylate) layers following various isothermal annealing treatments: temperatures were kept below 170 degrees C to prevent degradation of the polymer. Since PTBA also degrades when the ion beam impinges the sample, it was necessary to quantify the mass loss in order to obtain accurate diffusion coefficients. Although the total mass loss was substantial (40-60%). a simple expansion of the energy-to-depth scale was sufficient to account for the beam-induced shrinkage. This result is attributed to the fact that the mass loss occurs very rapidly, and is uniformly distributed through the depth of the sample. The data reveal that the diffusion of the nanometer-size gold particles is substantially slower than is predicted by a simple physical model (Stokes-Einstein) for noninteracting particles. This slowdown is attributed to polymer bridging interactions, in which polymer strands bind to individual metal particles, thereby retarding their diffusion. (C) 1998 Elsevier Science B.V. C1 Northwestern Univ, Dept Mat Sci & Engn, Evanston, IL 60208 USA. Argonne Natl Lab, Div Sci Mat, Argonne, IL 60439 USA. RP Shull, KR (reprint author), Northwestern Univ, Dept Mat Sci & Engn, Evanston, IL 60208 USA. EM k-shull@nwu.edu RI Shull, Kenneth/B-7536-2009 NR 7 TC 5 Z9 5 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-583X J9 NUCL INSTRUM METH B JI Nucl. Instrum. Methods Phys. Res. Sect. B-Beam Interact. Mater. Atoms PD MAR PY 1998 VL 136 BP 283 EP 289 DI 10.1016/S0168-583X(97)00855-0 PG 7 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Atomic, Molecular & Chemical; Physics, Nuclear SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA ZW154 UT WOS:000074380400049 ER PT J AU Yasuda, K Nastasi, M Sickafus, KE Maggiore, CJ Yu, N AF Yasuda, K Nastasi, M Sickafus, KE Maggiore, CJ Yu, N TI Ion beam channeling study on the damage accumulation in yttria-stabilized cubic zirconia SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS LA English DT Article; Proceedings Paper CT 13th International Conference on Ion Beam Analysis (IBA-13) CY JUL 27-AUG 01, 1997 CL LISBON, PORTUGAL AB The lattice damage kinetics of defect accumulation in ion irradiated yttria-stabilized cubic zirconia (YSZ) was investigated by using in situ Rutherford backscattering spectrometry and channeling (RBS/C) techniques. The samples of single crystalline YSZ were irradiated with 400 keV Xe++ ions over a range of doses and for sample temperatures of 170 and 300 E;. Under all irradiation conditions studied, the samples remained crystalline. However, lattice damage, as measured by the minimum yield, chi(min) was observed to have three distinct stages (stages I-III) in the rate of accumulation. Energy dependent channeling experiments revealed -1 and 1/2 power dependence for the dechanneling parameter in stage I and stage III, respectively. Corresponding transmission electron microscopy (TEM) studies detected defects which appear as tiny dot contrasts in stage I samples, ultimately leading to the overlaps of dislocations at stage III. The three stages of damage accumulations have been interpreted as an evolving defect structure which changes the dominant RBS/C ion scattering process from direct scattering to dechanneling. A comparison between RBS/C and TEM techniques has also been made for the effective use of in situ RBS/C techniques for the study of radiation damage. (C) 1998 Elsevier Science B.V. C1 Univ Calif Los Alamos Natl Lab, Div Mat Sci & Technol, Los Alamos, NM 87545 USA. Kyushu Univ, Dept Nucl Engn, Fukuoka 81281, Japan. Texas Instruments Inc, Dallas, TX 75243 USA. RP Nastasi, M (reprint author), Univ Calif Los Alamos Natl Lab, Div Mat Sci & Technol, Los Alamos, NM 87545 USA. EM nasty@lanl.gov NR 12 TC 47 Z9 47 U1 4 U2 15 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-583X J9 NUCL INSTRUM METH B JI Nucl. Instrum. Methods Phys. Res. Sect. B-Beam Interact. Mater. Atoms PD MAR PY 1998 VL 136 BP 499 EP 504 DI 10.1016/S0168-583X(97)00898-7 PG 6 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Atomic, Molecular & Chemical; Physics, Nuclear SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA ZW154 UT WOS:000074380400088 ER PT J AU Dytlewski, N Evans, PJ Brown, IG Liu, F Oks, EM Yushkov, GY AF Dytlewski, N Evans, PJ Brown, IG Liu, F Oks, EM Yushkov, GY TI Time-of-flight ERDA of dual implanted metals SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS LA English DT Article; Proceedings Paper CT 13th International Conference on Ion Beam Analysis (IBA-13) CY JUL 27-AUG 01, 1997 CL LISBON, PORTUGAL ID ARC ION-SOURCE AB Heavy Ion Time-of-Flight Recoil Spectrometry has been used to measure the implant distributions and dose in metal surfaces subject to dual ion implantation. Polished specimens of type 304 stainless steel were simultaneously implanted with both metallic and gaseous species produced from a modified metal vapour vacuum are ion source (MEVVA). The combination of ions used were Al + O, Cr + O, Zr + O and Ti + N. Results show that the retained doses differ significantly from the expected applied values, and metal-gas implant ratios. In particular, the metal-oxygen systems show an anomalously low retained metal dose. (C) 1998 Elsevier Science B.V. C1 Australian Nucl Sci & Technol Org, Menai, NSW 2234, Australia. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. Russian Acad Sci, Inst High Current Elect, Tomsk 634050, Russia. State Acad Control Syst & Radioelectron, Tomsk 634050, Russia. RP Dytlewski, N (reprint author), Australian Nucl Sci & Technol Org, PMB 1, Menai, NSW 2234, Australia. RI Oks, Efim/A-9409-2014; Yushkov, Georgy/O-8024-2015 OI Oks, Efim/0000-0002-9323-0686; Yushkov, Georgy/0000-0002-7615-6058 NR 10 TC 2 Z9 2 U1 1 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-583X J9 NUCL INSTRUM METH B JI Nucl. Instrum. Methods Phys. Res. Sect. B-Beam Interact. Mater. Atoms PD MAR PY 1998 VL 136 BP 644 EP 648 DI 10.1016/S0168-583X(97)00782-9 PG 5 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Atomic, Molecular & Chemical; Physics, Nuclear SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA ZW154 UT WOS:000074380400113 ER PT J AU Roth, J Walsh, DS Wampler, WR Mayer, M AF Roth, J Walsh, DS Wampler, WR Mayer, M TI Ion beam analysis of oxidised a-C : D layers on Be - A comparison of He-4 RBS and Si-28 ERD analysis SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS LA English DT Article; Proceedings Paper CT 13th International Conference on Ion Beam Analysis (IBA-13) CY JUL 27-AUG 01, 1997 CL LISBON, PORTUGAL ID RUTHERFORD BACKSCATTERING; CROSS-SECTION AB The composition of intermixed layers on Be containing H, D, Be, C and O has been analysed using conventional He-4 RES at 2.2 MeV together with 2.5 MeV He-4 ERD for hydrogen isotope analysis. The results are compared with heavy ion ERD using 12-40 MeV Si incident ions and detection of recoils without mass separation. For the analysis of the RES and ERD data the newly developed spectra simulation program SIMNRA has been used. The advantages and disadvantages of both methods in respect to depth resolution, data analysis and radiation damage are discussed. (C) 1998 Elsevier Science B.V. C1 EURATOM Assoc, Max Planck Inst Plasmaphys, D-85748 Garching, Germany. Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Roth, J (reprint author), EURATOM Assoc, Max Planck Inst Plasmaphys, D-85748 Garching, Germany. OI Mayer, Matej/0000-0002-5337-6963 NR 23 TC 3 Z9 3 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-583X J9 NUCL INSTRUM METH B JI Nucl. Instrum. Methods Phys. Res. Sect. B-Beam Interact. Mater. Atoms PD MAR PY 1998 VL 136 BP 689 EP 694 DI 10.1016/S0168-583X(97)00774-X PG 6 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Atomic, Molecular & Chemical; Physics, Nuclear SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA ZW154 UT WOS:000074380400121 ER PT J AU Banks, JC Doyle, BL Knapp, JA Werho, D Gregory, RB Anthony, M Hurd, TQ Diebold, AC AF Banks, JC Doyle, BL Knapp, JA Werho, D Gregory, RB Anthony, M Hurd, TQ Diebold, AC TI Using heavy ion backscattering spectrometry (HIBS) to solve integrated circuit manufacturing problems SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS LA English DT Article; Proceedings Paper CT 13th International Conference on Ion Beam Analysis (IBA-13) CY JUL 27-AUG 01, 1997 CL LISBON, PORTUGAL ID TRACE AB Heavy Ion Backscattering Spectrometry (HIBS) is a new IBA tool for measuring extremely low levels of surface contamination on very pure substrates, such as Si wafers used in the manufacture of integrated circuits. HIBS derives its high sensitivity through the use of moderately low energy (similar to 100 keV) heavy ions (e,g. C-12) to boost the RES cross-section to levels approaching 1000 b, and by using specially designed time-of-flight (TOF) detectors which have been optimized to provide a large scattering solid angle with minimal kinematic broadening. A HIBS User Facility has been created which provides US industry, national laboratories, and universities with a place for conducting ultra-trace level surface contamination studies. A review of the HIBS technique is given and examples of using the facility to calibrate Total-Reflection X-ray Fluorescence Spectroscopy (TXRF) instruments and develop wafer cleaning processes are discussed. (C) 1998 Elsevier Science B.V. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. Motorola Inc, Mesa, AZ 85202 USA. Texas Instruments Inc, Dallas, TX 75243 USA. SEMATECH, Austin, TX 78741 USA. RP Banks, JC (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. NR 10 TC 10 Z9 10 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-583X J9 NUCL INSTRUM METH B JI Nucl. Instrum. Methods Phys. Res. Sect. B-Beam Interact. Mater. Atoms PD MAR PY 1998 VL 136 BP 1223 EP 1228 DI 10.1016/S0168-583X(97)00817-3 PG 6 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Atomic, Molecular & Chemical; Physics, Nuclear SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA ZW154 UT WOS:000074380400218 ER PT J AU Breese, MBH Horn, KM AF Breese, MBH Horn, KM TI The influence of ion induced damage on lateral charge collection and IBIC image contrast SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS LA English DT Article; Proceedings Paper CT 13th International Conference on Ion Beam Analysis (IBA-13) CY JUL 27-AUG 01, 1997 CL LISBON, PORTUGAL DE IBIC microscopy; lateral charge diffusion; ion induced damage; integrated circuit analysis ID BEAM-INDUCED CHARGE; MICROSCOPY; ICS AB High resolution, calibrated ion beam induced charge (IBIC) measurements from integrated circuit test structures have demonstrated that the measured charge collection in a device can exhibit significant change after only a few hundred ions/mu m(2)? exposure, which may easily be exceeded in the initial targeting of a structure. For the purposes of determining a circuit's upset immunity or undamaged charge collection characteristics, such behaviour must be accounted for in evaluating IBIC measurements. This paper examines the influence of low level, ion induced damage on the magnitude of the measured lateral charge collection and also its resulting impact on IBIC image contrast. The lateral charge collection process is first characterised by calculating the amount of charge which diffuses to a collecting junction as a function of carrier diffusion length and the distance between the ion strike and junction edge. The effect of accumulated ion induced damage on lateral charge collection is then incorporated as a decrease in the resultant diffusion length. Calibrated IBIC measurements from the drain of a test FET structure are then explained using this predicted behaviour. (C) 1998 Elsevier Science B.V. C1 Univ Lisbon, CFNUL, P-1699 Lisbon, Portugal. Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Breese, MBH (reprint author), Univ Lisbon, CFNUL, Av Prof Gama Pinto 2, P-1699 Lisbon, Portugal. EM breese@alf4.cii.fc.ul.pt RI Breese, Mark/G-2068-2012 NR 16 TC 1 Z9 1 U1 0 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-583X J9 NUCL INSTRUM METH B JI Nucl. Instrum. Methods Phys. Res. Sect. B-Beam Interact. Mater. Atoms PD MAR PY 1998 VL 136 BP 1349 EP 1354 DI 10.1016/S0168-583X(97)00852-5 PG 6 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Atomic, Molecular & Chemical; Physics, Nuclear SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA ZW154 UT WOS:000074380400241 ER PT J AU Feng, JL AF Feng, JL TI New probes of supersymmetry beyond the minimal framework SO NUCLEAR PHYSICS B-PROCEEDINGS SUPPLEMENTS LA English DT Article; Proceedings Paper CT 5th International Conference on Supersymmetries in Physics CY MAY 27-31, 1997 CL PHILADELPHIA, PENNSYLVANIA ID LEPTON FLAVOR; COLLIDERS AB If supersymmetry is discovered at future colliders, what can we learn? While our appreciation of the variety of possible supersymmetric models has grown tremendously in recent years, most attempts to answer this question have been in the context of some simple and highly restrictive framework, such as minimal supergravity. In this talk I describe new probes of phenomena that are generic in models beyond the minimal framework. These include tests of supersymmetric flavor and CP violation and probes of kinematically inaccessible superparticle sectors through "super-oblique corrections." Such probes have wide applicability to distinguishing models, from gravity- and gauge-mediated theories to hybrid models and models with flavor symmetries. Examples of measurements at LEP II, the LHC, and the NLC are given. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. RP Feng, JL (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. NR 25 TC 1 Z9 1 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 MAR PY 1998 VL 62 BP 36 EP 46 DI 10.1016/S0920-5632(97)00641-5 PG 11 WC Physics, Particles & Fields SC Physics GA ZG188 UT WOS:000072976000005 ER PT J AU Pierce, DM Erler, J AF Pierce, DM Erler, J TI chi(2) analysis of supersymmetric models SO NUCLEAR PHYSICS B-PROCEEDINGS SUPPLEMENTS LA English DT Article; Proceedings Paper CT 5th International Conference on Supersymmetries in Physics CY MAY 27-31, 1997 CL PHILADELPHIA, PENNSYLVANIA ID RENORMALIZATION-GROUP EQUATIONS; W-BOSON MASS; QUANTUM-FIELD THEORY; SOFTLY BROKEN SUPERSYMMETRY; RADIATIVE-CORRECTIONS; GRAND UNIFICATION; ATOMIC THALLIUM; STANDARD MODEL; SUPERGRAVITY; BREAKING AB We discuss the results of a global fit to precision data in supersymmetric models. We consider both gravity- and gauge-mediated models. As the superpartner spectrum becomes light, the global fit to the data typically results in larger values of chi(2). We indicate the regions of parameter space which are excluded by the data. We discuss the additional effect of the B(B --> X-s gamma) measurement. Our analysis excludes chargino masses below M-z in the simplest gauge-mediated model with mu > 0, With stronger constraints for larger values of tan beta. C1 Stanford Univ, Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. Univ Calif Santa Cruz, Inst Particle Phys, Santa Cruz, CA 95064 USA. RP Pierce, DM (reprint author), Stanford Univ, Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. NR 64 TC 5 Z9 5 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 MAR PY 1998 VL 62 BP 97 EP 107 DI 10.1016/S0920-5632(97)00647-6 PG 11 WC Physics, Particles & Fields SC Physics GA ZG188 UT WOS:000072976000011 ER PT J AU Feng, JL Moroi, T AF Feng, JL Moroi, T TI Determining tan beta at the NLC with SUSY Higgs bosons SO NUCLEAR PHYSICS B-PROCEEDINGS SUPPLEMENTS LA English DT Article; Proceedings Paper CT 5th International Conference on Supersymmetries in Physics CY MAY 27-31, 1997 CL PHILADELPHIA, PENNSYLVANIA ID SUPERSYMMETRIC STANDARD MODEL; GRAND UNIFIED THEORIES; QUARK-MASS PREDICTION; QCD CORRECTIONS; RADIATIVE-CORRECTIONS; E(+)E(-) COLLIDERS; LINEAR COLLIDER; SFERMION MASSES; UNIFICATION; DECAY AB We examine the prospects for determining tan beta From heavy Higgs scalar production in the minimal supersymmetric standard model at a future e(+)e(-) collider. Our analysis is independent of assumptions of parameter unification, and we consider general radiative corrections in the Higgs sector. Bounds are presented for root s = 500 GeV and 1 TeV, several Higgs masses, and a variety of integrated luminosities. For all cases considered, it is possible to distinguish low, moderate, and high tan beta. In addition, we find stringent constraints for 3 less than or similar to tan beta less than or similar to 10, and, for some scenarios, also interesting bounds on high tan beta through tbH(+/-) production. Such measurements may provide strong tests of the Yukawa unifications in grand unified theories and make possible highly precise determinations of soft SUSY breaking mass parameters. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. RP Feng, JL (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. NR 33 TC 3 Z9 3 U1 0 U2 1 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 MAR PY 1998 VL 62 BP 108 EP 115 DI 10.1016/S0920-5632(97)00648-8 PG 8 WC Physics, Particles & Fields SC Physics GA ZG188 UT WOS:000072976000012 ER PT J AU Wu, YY AF Wu, YY TI Recent progress in weakly-coupled heterotic string phenomenology SO NUCLEAR PHYSICS B-PROCEEDINGS SUPPLEMENTS LA English DT Article; Proceedings Paper CT 5th International Conference on Supersymmetries in Physics CY MAY 27-31, 1997 CL PHILADELPHIA, PENNSYLVANIA ID DYNAMICAL SUPERSYMMETRY BREAKING; COSMOLOGICAL MODULI PROBLEM; SUPERSTRING MODELS; LINEAR MULTIPLET; INVISIBLE AXION; GAUGINO CONDENSATION; SUPERGRAVITY; UNIFICATION; COMPACTIFICATION; SCALE AB Some recent developments in the weakly-coupled heterotic sl,ring phenomenology are reviewed. We discuss several important issues such as dilaton/moduli stabilization, supersymmetry breaking (by hidden-sector gaugino condensation), gauge coupling unification (or the Newton's constant), the QCD axion, as well as cosmological problems involving the dilaton/moduli and the axion. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Theoret Phys Grp, Berkeley, CA 94720 USA. RP Wu, YY (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Theoret Phys Grp, Berkeley, CA 94720 USA. NR 54 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 MAR PY 1998 VL 62 BP 197 EP 203 DI 10.1016/S0920-5632(97)00657-9 PG 7 WC Physics, Particles & Fields SC Physics GA ZG188 UT WOS:000072976000021 ER PT J AU Wells, JD AF Wells, JD TI Dark-matter in gravity-mediated supersymmetry breaking SO NUCLEAR PHYSICS B-PROCEEDINGS SUPPLEMENTS LA English DT Article; Proceedings Paper CT 5th International Conference on Supersymmetries in Physics CY MAY 27-31, 1997 CL PHILADELPHIA, PA ID DISCRETE GAUGE-SYMMETRY; STANDARD MODEL; MASSES; CONSERVATION; PHENOMENOLOGY; NEUTRALINO; EXISTENCE; PHOTINO; NUMBER AB In R parity conserving supersymmetric theories, the lightest superpartner (LSP) is stable. The LSPs may comprise a large fraction of the energy density of the current universe, which would lead to dramatic astrophysical consequences. In this talk, I will discuss some of the main points we have learned about supersymmetric models from relic abundance considerations of the LSP. C1 Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. RP Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. NR 37 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 EI 1873-3832 J9 NUCL PHYS B-PROC SUP JI Nucl. Phys. B-Proc. Suppl. PD MAR PY 1998 VL 62 BP 235 EP 240 DI 10.1016/S0920-5632(97)00662-2 PG 6 WC Physics, Particles & Fields SC Physics GA ZG188 UT WOS:000072976000026 ER PT J AU Riotto, A AF Riotto, A TI The superhot, superdense, supersymmetric universe SO NUCLEAR PHYSICS B-PROCEEDINGS SUPPLEMENTS LA English DT Article; Proceedings Paper CT 5th International Conference on Supersymmetries in Physics CY MAY 27-31, 1997 CL PHILADELPHIA, PA ID SYMMETRY NON-RESTORATION; HIGH-TEMPERATURE; BARYON ASYMMETRY; MONOPOLE PROBLEM; GAUGE THEORIES; HIGH-DENSITY; CONDENSATION; BREAKING AB In this talk the following question is addressed: are internal symmetries necessarily restored at high temperature in supersymmetric theories? Contrary to the general belief, we argue that the answer is no when systems possess a net background charge. Our findings are exemplified on abelian models, for both cases of global and local symmetries and possible cosmological implications are also discussed. C1 Fermilab Natl Accelerator Lab, NASA, Fermilab Astrophys Ctr, Batavia, IL 60510 USA. RP Fermilab Natl Accelerator Lab, NASA, Fermilab Astrophys Ctr, POB 500, Batavia, IL 60510 USA. NR 27 TC 3 Z9 3 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0920-5632 EI 1873-3832 J9 NUCL PHYS B-PROC SUP JI Nucl. Phys. B-Proc. Suppl. PD MAR PY 1998 VL 62 BP 253 EP 258 DI 10.1016/S0920-5632(97)00665-8 PG 6 WC Physics, Particles & Fields SC Physics GA ZG188 UT WOS:000072976000029 ER PT J AU Poppitz, E Trivedi, SP AF Poppitz, E Trivedi, SP TI Gauge-mediated supersymmetry breaking within the dynamical messenger sector SO NUCLEAR PHYSICS B-PROCEEDINGS SUPPLEMENTS LA English DT Article; Proceedings Paper CT 5th International Conference on Supersymmetries in Physics CY MAY 27-31, 1997 CL PHILADELPHIA, PENNSYLVANIA ID DUALITY AB We consider the idea of combining the supersymmetry breaking and messenger sectors in models of gauge-mediated supersymmetry breaking. We discuss the advantages and problems of such models, and present an existence proof by constructing an explicit example. We explore in some detail the low-energy supersymmetry-breaking dynamics and the generation of supersymmetry-breaking soft masses of the standard model superpartners, and discuss many features which are likely to be shared by more realistic models with dynamical messengers. C1 Univ Chicago, Enrico Fermi Inst, Chicago, IL 60657 USA. Fermi Natl Accelerator Lab, Batavia, IL 60510 USA. RP Poppitz, E (reprint author), Univ Calif San Diego, Dept Phys, 9500 Gilman Dr, La Jolla, CA 92093 USA. NR 17 TC 3 Z9 3 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 MAR PY 1998 VL 62 BP 281 EP 288 DI 10.1016/S0920-5632(97)00669-5 PG 8 WC Physics, Particles & Fields SC Physics GA ZG188 UT WOS:000072976000033 ER PT J AU Murayama, H AF Murayama, H TI Gauge mediation without a messenger sector SO NUCLEAR PHYSICS B-PROCEEDINGS SUPPLEMENTS LA English DT Article; Proceedings Paper CT 5th International Conference on Supersymmetries in Physics CY MAY 27-31, 1997 CL PHILADELPHIA, PENNSYLVANIA ID DYNAMICAL SUPERSYMMETRY BREAKING; MASS AB I present a model of gauge mediation without a messenger sector. This is the first phenomenologically viable model of this type. The sector of dynamical supersymmetry breaking couples directly to the standard model gauge groups. The apparent gauge unification is preserved despite the direct coupling. The inverted hierarchy mechanism plays a crucial role in dynamics. The model is completely chiral, and hence there is no need to forbid mass terms by hand. Still vector-like messengers emerge as a consequence of dynamical breakdown of gauge symmetries. C1 Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Theoret Phys Grp, Berkeley, CA 94720 USA. RP Murayama, H (reprint author), Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. RI Murayama, Hitoshi/A-4286-2011 NR 34 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 MAR PY 1998 VL 62 BP 289 EP 298 DI 10.1016/S0920-5632(97)00670-1 PG 10 WC Physics, Particles & Fields SC Physics GA ZG188 UT WOS:000072976000034 ER PT J AU Marciano, WJ AF Marciano, WJ TI SUSY perspective and outlook SO NUCLEAR PHYSICS B-PROCEEDINGS SUPPLEMENTS LA English DT Article; Proceedings Paper CT 5th International Conference on Supersymmetries in Physics CY MAY 27-31, 1997 CL PHILADELPHIA, PA ID FINE-STRUCTURE CONSTANT; G-2; ELECTRON AB A general perspective on the standard model and its supersymmetric extension is given. Possible advances via High Precision, High Rate, and High Energy experimental initiatives are described. An outlook on the future is given. C1 Brookhaven Natl Lab, Upton, NY 11973 USA. RP Brookhaven Natl Lab, Upton, NY 11973 USA. NR 17 TC 2 Z9 2 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0920-5632 EI 1873-3832 J9 NUCL PHYS B-PROC SUP JI Nucl. Phys. B-Proc. Suppl. PD MAR PY 1998 VL 62 BP 457 EP 462 DI 10.1016/S0920-5632(97)00686-5 PG 6 WC Physics, Particles & Fields SC Physics GA ZG188 UT WOS:000072976000050 ER PT J AU Stamps, DW AF Stamps, DW TI Analyses of the thermal hydraulics in the NUPEC 1/4-scale model containment experiments SO NUCLEAR SCIENCE AND ENGINEERING LA English DT Article AB The CONTAIN code was used to predict the helium concentrations, gas temperatures and pressures, and wall temperatures of four experiments performed in the NUPEC 1/4-scale model containment These experiments investigated the thermal-hydraulic effects of helium and steam source flow rates, source elevation, and internal water sprays. Two CONTAIN flow solvers and two nodalization schemes were assessed. One NUPEC test, International Standard Problem 35, was investigated in detail, including the pretest heating phase. The thermal hydraulics of this test were dominated by internal water sprays. A modeling approach based on the assumption that the water sprays generated a large air vortex yielded the best results. Reasons for deviations between the predictions and data are suggested based on experimental uncertainties, different analysis methods, and nodalization schemes. C1 Sandia Natl Labs, Modeling & Anal Dept 6421, Albuquerque, NM 87185 USA. RP Stamps, DW (reprint author), Univ Evansville, Dept Mech & Civil Engn, 1800 Lincoln Ave, Evansville, IN 47722 USA. NR 14 TC 7 Z9 7 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 MAR PY 1998 VL 128 IS 3 BP 243 EP 269 PG 27 WC Nuclear Science & Technology SC Nuclear Science & Technology GA ZA693 UT WOS:000072391600002 ER PT J AU Loaiza, DJ Brunson, G Sanchez, R Butterfield, K AF Loaiza, DJ Brunson, G Sanchez, R Butterfield, K TI Measurements of absolute delayed neutron yield and group constants in the fast fission of U-235 and Np-237 SO NUCLEAR SCIENCE AND ENGINEERING LA English DT Article ID PARAMETERS AB The delayed neutron activity resulting from the fast induced fission of U-235 and Np-237 has been studied. The sir-group decay constants, relative abundances, and absolute yield of delayed neutrons from fast fission of U-235 and Np-237 were measured using the Godiva IV fast assembly at the Los Alamos Critical Experiment Facility. The absolute yield measured for U-235 was 0.0163 +/- 0.0008 neutron/fission. This value compares very well with the well-established Keepin absolute yield of 0.0165 +/- 0.0005. The absolute yield value measured for Np-237 was 0.0126 +/- 0.0007. The measured delayed neutron parameters for U-235 are corroborated with period (e-folding time) versus reactivity calculations. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Loaiza, DJ (reprint author), Univ Calif Los Alamos Natl Lab, POB 1663,MS J562, Los Alamos, NM 87545 USA. NR 19 TC 7 Z9 7 U1 0 U2 1 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 MAR PY 1998 VL 128 IS 3 BP 270 EP 277 PG 8 WC Nuclear Science & Technology SC Nuclear Science & Technology GA ZA693 UT WOS:000072391600003 ER PT J AU Baker, RS Koch, KR AF Baker, RS Koch, KR TI An S-n algorithm for the massively parallel CM-200 computer SO NUCLEAR SCIENCE AND ENGINEERING LA English DT Article ID NEUTRON-TRANSPORT AB A parallel three-dimensional S-n algorithm is described for performing eigenvalue calculations on rectangular meshes using the Thinking Machines Connection Machine model CM-200 computer. By using a two-dimensional spatial decomposition. We retain the ability to invert the source iteration equation in a single "sweep." Thus, this scheme gives essentially problem-independent performance in the sense that it represents an intrinsic decomposition. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Baker, RS (reprint author), Univ Calif Los Alamos Natl Lab, Mail Stop B226, Los Alamos, NM 87545 USA. NR 17 TC 44 Z9 50 U1 0 U2 2 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 MAR PY 1998 VL 128 IS 3 BP 312 EP 320 PG 9 WC Nuclear Science & Technology SC Nuclear Science & Technology GA ZA693 UT WOS:000072391600006 ER PT J AU Dosanjh, MK Collins, DW Fan, WF Lennon, GG Albala, JS Shen, ZY Schild, D AF Dosanjh, MK Collins, DW Fan, WF Lennon, GG Albala, JS Shen, ZY Schild, D TI Isolation and characterization of RAD51C, a new human member of the RAD51 family of related genes SO NUCLEIC ACIDS RESEARCH LA English DT Article ID SACCHAROMYCES-CEREVISIAE; 2-HYBRID SYSTEM; PROTEIN; RECOMBINATION; REPAIR; RECA; YEAST; MOUSE; CDNA; HOMOLOGS AB The yeast and human RAD51 genes encode strand-transfer proteins that are thought to be involved in both recombinational repair of DNA damage and meiotic recombination, In yeast, the Rad51 family of related proteins also includes Rad55, Rad57 and Dmc1, In mammalian cells, five genes in this family have been identified (HsRAD51, XRCC2, XRCC3, RAD41B/hREC2 and HsDMC1), and here we report the isolation of the sixth member, RAD51C, RAD51C was originally identified by a computer screen of the EST database, A full-length similar to 1.3 kb cDNA clone has been isolated that encodes a protein of 376 aa, having a 18-26% aa identity with other human Rad51 family members. RAD51C includes a previously mapped sequenced-tagged site location near the end of chromosome 17q. The RAD51C transcript is expressed in various human tissues, with highest level of expression in testis, followed by heart muscle, spleen and prostate, Yeast two-hybrid experiments indicate that the Rad51C protein binds to two other members of the Rad51 protein family (Xrcc3 and Rad51B) but not to itself, These findings suggest that Rad51C may function similarly to the yeast Rad55 or Rad57 proteins, rather than as a Rad51 functional homolog. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Div Life Sci, Berkeley, CA 94720 USA. Univ Calif Lawrence Livermore Natl Lab, Biol & Biotechnol Res Program, Livermore, CA 94550 USA. Univ Calif Los Alamos Natl Lab, Div Life Sci, Los Alamos, NM 87545 USA. RP Schild, D (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Div Life Sci, Bldg 70A,Room 1118,1 Cyclotron Rd, Berkeley, CA 94720 USA. FU NIEHS NIH HHS [ES08353]; NIGMS NIH HHS [GM30990] NR 34 TC 124 Z9 128 U1 0 U2 3 PU OXFORD UNIV PRESS PI OXFORD PA GREAT CLARENDON ST, OXFORD OX2 6DP, ENGLAND SN 0305-1048 J9 NUCLEIC ACIDS RES JI Nucleic Acids Res. PD MAR 1 PY 1998 VL 26 IS 5 BP 1179 EP 1184 DI 10.1093/nar/26.5.1179 PG 6 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA ZA438 UT WOS:000072363300007 PM 9469824 ER PT J AU Kotzerke, J Rentschler, M Glatting, G Schneider, E Stabin, M Knapp, FF Reske, SN AF Kotzerke, J Rentschler, M Glatting, G Schneider, E Stabin, M Knapp, FF Reske, SN TI Dosimetric fundamentals of endovascular brachytherapy using Re-188 to prevent restenosis after angioplasty SO NUKLEARMEDIZIN LA German DT Article DE Re-188; dosimetry; brachytherapy; angioplasty ID MUSCLE CELL-PROLIFERATION; CORONARY ANGIOPLASTY; NEOINTIMAL PROLIFERATION; RADIONUCLIDE GENERATOR; STENT IMPLANTATION; IRRADIATION; HYPERPLASIA; ARTERIES; SWINE AB Aim: Various radionuclides can be used for endovascular brachytherapy. A new concept is to inflate the balloon of a dilitation catheter with a radioactive solution. Re-188 can be eluated from a generator system and is available daily. The aim of this study was to obtain dosimetric data for this radionuclide. Methods: The dose decrease of Re-188 was calculated and measured with a TLD-system radial to a balloon catheter typically used in cardiology (diameter: 3 mm, length: 20 mm). Results: Using a specific acitivity of 370 MBq/ml a dose of 0,3 Gy could be achieved within 1 min in a TLD in contact with the balloon. Paired TLDs differed about 3%. A fast dose reduction of 50% and 10% were stated within 0.5 mm and 2.5 mm, respectively. Calculated and measured values were in good agreement. The data are comparable to those known for Y-90. Conclusion: Calculations of dose distribution are consistent with TLD measurements of Re-188. Using a specific acitivity of 1.85 GBq/ml, a dose of 10-15 Gy at the coronary artery wall can be achieved within 2-3 min. Compared to radioactive stents or wires the use of this liquid beta-emitter is a simple alternative for prevention of the restenosis following the angioplasty. C1 Univ Ulm, D-89069 Ulm, Germany. ORISE, Oakland, CA USA. Oak Ridge Natl Lab, Nucl Med Grp, Oakland, CA USA. RP Kotzerke, J (reprint author), Univ Ulm Klinikum, D-89070 Ulm, Germany. NR 31 TC 20 Z9 22 U1 0 U2 0 PU F K SCHATTAUER VERLAG GMBH PI STUTTGART PA P O BOX 10 45 45, LENZHALDE 3, D-70040 STUTTGART, GERMANY SN 0029-5566 J9 NUKLEARMED JI Nuklearmedizin PD MAR PY 1998 VL 37 IS 2 BP 68 EP 72 PG 5 WC Radiology, Nuclear Medicine & Medical Imaging SC Radiology, Nuclear Medicine & Medical Imaging GA ZE817 UT WOS:000072834400007 PM 9547753 ER PT J AU Ditmire, T Smith, RA Hutchinson, MHR AF Ditmire, T Smith, RA Hutchinson, MHR TI Plasma waveguide formation in predissociated clustering gases SO OPTICS LETTERS LA English DT Article ID UNDERDENSE PLASMA; LASER-PULSES; IONIZATION AB We report on the use of a novel technique to create a plasma waveguide suitable for guiding high-intensity laser pulses in underdense plasmas. A narrow channel of a clustering gas is dissociated with a low-intensity prepulse. This prepulse is followed by a high-intensity, focused laser pulse. The high absorption of the clusters surrounding the dissociated atomic channel causes the remaining annulus of clusters to become highly ionized, leaving low-density plasma in the center. We have interferometrically probed the formation of this channel with picosecond laser pulses. (C) 1998 Optical Society of America. C1 Univ London Imperial Coll Sci Technol & Med, Blackett Lab, London SW7 2BZ, England. RP Ditmire, T (reprint author), Univ Calif Lawrence Livermore Natl Lab, L-440, Livermore, CA 94550 USA. NR 13 TC 25 Z9 25 U1 1 U2 1 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 MAR 1 PY 1998 VL 23 IS 5 BP 322 EP 324 DI 10.1364/OL.23.000322 PG 3 WC Optics SC Optics GA ZA057 UT WOS:000072324400004 PM 18084499 ER PT J AU George, EP Baker, I AF George, EP Baker, I TI A model for the yield strength anomaly of Fe-Al SO PHILOSOPHICAL MAGAZINE A-PHYSICS OF CONDENSED MATTER STRUCTURE DEFECTS AND MECHANICAL PROPERTIES LA English DT Article ID SINGLE-CRYSTALS; BETA-CUZN; TEMPERATURE-DEPENDENCE; TENSILE PROPERTIES; INTERMETALLIC COMPOUNDS; DISLOCATION-STRUCTURES; DEFORMATION-BEHAVIOR; CLIMB DISSOCIATION; PLASTIC-FLOW; B2 STRUCTURE AB A phenomenological model is introduced for the temperature dependence of the yield strength of Fe-Al. The key feature of the model is that it incorporates hardening by thermal vacancies to account for the yield strength anomaly. Since the vacancy concentration C-V varies as exp(-1/T) and the hardening due to vacancies varies as C-V(1/2), the model predicts at intermediate temperatures an exponential increase in strength with increasing temperature. This increasing strength is terminated by the onset of dislocation creep. The model includes strain rate dependences that are consistent with experimental observations and yields an activation enthalpy for vacancy formation which is in excellent agreement with a previously measured value. C1 Oak Ridge Natl Lab, Div Met & Ceram, Oak Ridge, TN 37831 USA. Dartmouth Coll, Thayer Sch Engn, Hanover, NH 03755 USA. RP George, EP (reprint author), Oak Ridge Natl Lab, Div Met & Ceram, POB 2008, Oak Ridge, TN 37831 USA. RI George, Easo/L-5434-2014 NR 59 TC 69 Z9 69 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 MAR PY 1998 VL 77 IS 3 BP 737 EP 750 PG 14 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering; Physics, Applied; Physics, Condensed Matter SC Materials Science; Metallurgy & Metallurgical Engineering; Physics GA YZ239 UT WOS:000072234200013 ER PT J AU Reardon, BJ Kieffer, J AF Reardon, BJ Kieffer, J TI Phase stability limits via non-equilibrium normal mode analysis SO PHILOSOPHICAL MAGAZINE B-PHYSICS OF CONDENSED MATTER STATISTICAL MECHANICS ELECTRONIC OPTICAL AND MAGNETIC PROPERTIES LA English DT Article ID INSTANTANEOUS NORMAL-MODES; DIFFUSION; LIQUIDS AB Alkali chlorides in both their rock-salt and CsCl modifications were isotropically expanded or compressed to produce non-equilibrium structures while preserving the crystal symmetries and perfect force balance. These structures were analysed by determining the eigenvalues of the linearized Hamiltonian equations of motion. This procedure, which is similar to normal mode analysis, yields all elastic coefficients and the spectrum of rates of motion, which can include oscillatory as well as aperiodic modes. In balanced structures, the onset of aperiodic modes of motion coincides with singularities or roots in the density dependence of elastic coefficients. This onset is interpreted as the limit of stability for a given crystallographic phase and, by comparing the values of the various elastic constants, some information about the type of transition that is impending at those densities can be obtained. Results for chlorides with varying alkali cation are consistent with the experimentally observed phase stability trends. Violation of the symmetry due to thermal disorder or lattice defects, however; affects the onset of unstable modes and the roots of elastic constants in opposite ways, suggesting that the phase stability is sensitive to localized extreme states, while the mechanical properties are derived from ensemble averages. C1 Univ Illinois, Dept Mat Sci & Engn, Urbana, IL 61801 USA. RP Reardon, BJ (reprint author), Univ Calif Los Alamos Natl Lab, Div Mat Sci & Technol, Los Alamos, NM 87545 USA. NR 19 TC 3 Z9 3 U1 0 U2 0 PU TAYLOR & FRANCIS LTD PI LONDON PA ONE GUNPOWDER SQUARE, LONDON EC4A 3DE, ENGLAND SN 0141-8637 J9 PHILOS MAG B JI Philos. Mag. B-Phys. Condens. Matter Stat. Mech. Electron. Opt. Magn. Prop. PD MAR PY 1998 VL 77 IS 3 BP 907 EP 924 DI 10.1080/13642819808214842 PG 18 WC Materials Science, Multidisciplinary; Mechanics; Physics, Applied; Physics, Condensed Matter SC Materials Science; Mechanics; Physics GA YZ241 UT WOS:000072234400013 ER PT J AU Abresch, EC Paddock, ML Stowell, MHB McPhillips, TM Axelrod, HL Soltis, SM Rees, DC Okamura, MY Feher, G AF Abresch, EC Paddock, ML Stowell, MHB McPhillips, TM Axelrod, HL Soltis, SM Rees, DC Okamura, MY Feher, G TI Identification of proton transfer pathways in the X-ray crystal structure of the bacterial reaction center from Rhodobacter sphaeroides SO PHOTOSYNTHESIS RESEARCH LA English DT Article; Proceedings Paper CT Workshop on Reaction Centers of Photosynthetic Purple Bacteria - Structure, Spectroscopy, Dynamics CY JUN 01-06, 1997 CL CADARACHE, FRANCE DE bacterial photosynthesis; crystal structure; electron transfer; proton transfer ID PHOTOSYNTHETIC REACTION-CENTER; SITE-DIRECTED MUTANTS; 2 IONIZABLE RESIDUES; QB-BINDING-SITE; ELECTRON-TRANSFER; PROTEIN INTERACTIONS; QUINONE; REDUCTION; R-26; Q(B) AB Structural features that have important implications for the fundamental process of transmembrane proton transfer are examined in the recently published high resolution atomic structures of the reaction center (RC) from Rhodobacter sphaeroides in the dark adapted state (DQ(A)Q(B)) and the charged separated state (D(+)Q(A)Q(B)(-)); the latter is the active state for proton transfer to the semiquinone. The structures have been determined at 2.2 Angstrom and 2.6 Angstrom resolution, respectively, as reported by Stowell et al. (1997) [Science 276: 812-816]. Three possible proton transfer pathways (P1, P2, P3) consisting of water molecules and/or protonatable residues were identified which connect the Q(B) binding region with the cytoplasmic exposed surface at Asp H224 & Asp M240 (P1), Tyr M3 (P2) and Asp M17 (P3). All three represent possible pathways for proton transfer into the RC. P1 contains an uninterrupted chain of water molecules. This path could, in addition, facilitate the exchange of quinone for quinol during the photocycle by allowing water to move into and out of the binding pocket. Located near these pathways is a cluster of electrostatically interacting acid residues (Asp-L213, Glu-H173, Asp-M17, Asp H124, Asp-L210 and Asp H170) each being within 4.5 Angstrom of a neighboring carboxylic acid or a bridging water molecule. This cluster could serve as an internal 'proton reservoir' facilitating fast protonation of Q(B)(-) that could occur at a rate greater than that attainable by proton uptake from solution. C1 Univ Calif San Diego, Dept Phys, La Jolla, CA 92093 USA. CALTECH, Div Chem & Chem Engn, Pasadena, CA 91125 USA. Stanford Univ, Stanford Synchrotron Radiat Lab, Stanford, CA 94305 USA. RP Feher, G (reprint author), Univ Calif San Diego, Dept Phys, La Jolla, CA 92093 USA. RI Feher, George/E-3050-2010 NR 30 TC 60 Z9 64 U1 0 U2 4 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0166-8595 J9 PHOTOSYNTH RES JI Photosynth. Res. PD MAR PY 1998 VL 55 IS 2-3 BP 119 EP 125 DI 10.1023/A:1006047519260 PG 7 WC Plant Sciences SC Plant Sciences GA 105MG UT WOS:000075076900002 ER PT J AU Tiede, DM Utschig, L Hanson, DK Gallo, DM AF Tiede, DM Utschig, L Hanson, DK Gallo, DM TI Resolution of electron and proton transfer events in the electrochromism associated with quinone reduction in bacterial reaction centers SO PHOTOSYNTHESIS RESEARCH LA English DT Article; Proceedings Paper CT Workshop on Reaction Centers of Photosynthetic Purple Bacteria - Structure, Spectroscopy, Dynamics CY JUN 01-06, 1997 CL CADARACHE, FRANCE DE bacterial photosynthesis; electrochromism; electron transfer; proton transfer; quinone; reaction center ID PHOTOSYNTHETIC REACTION CENTERS; RESOLVED INFRARED-SPECTROSCOPY; RHODOBACTER-SPHAEROIDES; RHODOPSEUDOMONAS-VIRIDIS; KINETICS; ACCEPTOR; COMPLEX AB We have measured the electrochromic response of the bacteriopheophytin, BPh, and bacteriochlorophyll, BChl, cofactors during the Q(A) (-)Q(B) --> Q(A)Q(B)(-) electron transfer in chromatophores of Rhodobacter (Rb.) capsulatus and Rb. sphaeroides. The electrochromic response rises faster in chromatophores and is more clearly biexponential than it is in isolated reaction centers. The chromatophore spectra can be interpreted in terms of a clear kinetic separation between fast electron transfer and slower non-electron transfer events such as proton transfer or protein relaxation. The electrochromic response to electron transfer exhibits rise times of about 4 mu s (70%) and 40 mu s (30%) in Rb. capsulatus and 4 mu s (60%) and 80 mu s (40%) in Rb. sphaeroides. The BPh absorption band is shifted to nearly equivalent positions in the Q(A)(-) and nascent Q(B)(-) states, indicating that the electrochromic perturbation of BPh absorption from the newly formed Q(B)(-) state is comparable to that of Q(A)(-). Subsequently, partial attenuation of the Q(B)(-) electrochromism occurs with a time constant on the order of 200 mu s. This can be attributed to partial charge compensation by H+ (or other counter ion) movement into the QB pocket. Electron transfer events were found to be slower in detergent isolated RCs than in chromatophores, more nearly monoexponential, and overlap H+ transfer, suggesting that a change in rate-limiting step has occurred upon detergent solubilization. C1 Argonne Natl Lab, Div Chem, Argonne, IL 60439 USA. Argonne Natl Lab, Ctr Mech Biol & Biotechnol, Argonne, IL 60439 USA. Augustana Coll, Rock Isl, IL 61201 USA. RP Tiede, DM (reprint author), Argonne Natl Lab, Div Chem, 9700 S Cass Ave, Argonne, IL 60439 USA. NR 21 TC 30 Z9 31 U1 0 U2 3 PU SPRINGER PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0166-8595 EI 1573-5079 J9 PHOTOSYNTH RES JI Photosynth. Res. PD MAR PY 1998 VL 55 IS 2-3 BP 267 EP 273 DI 10.1023/A:1006009529004 PG 7 WC Plant Sciences SC Plant Sciences GA 105MG UT WOS:000075076900021 ER PT J AU Hanson, DK Schiffer, M AF Hanson, DK Schiffer, M TI Symmetry-related mutants in the quinone binding sites of the bacterial reaction center - the effects of changes in charge distribution SO PHOTOSYNTHESIS RESEARCH LA English DT Article; Proceedings Paper CT Workshop on Reaction Centers of Photosynthetic Purple Bacteria - Structure, Spectroscopy, Dynamics CY JUN 01-06, 1997 CL CADARACHE, FRANCE DE electron transfer; phenotypic revertants; photosynthesis; proton transfer; site-specific mutagenesis ID PHOTOSYNTHETIC REACTION-CENTER; RHODOBACTER-SPHAEROIDES; PROTON-TRANSFER; RHODOPSEUDOMONAS-VIRIDIS; SECONDARY QUINONE; ELECTRON-TRANSFER; PROTEIN; SPECTROSCOPY; CAPSULATUS; PATHWAYS AB To probe the structural elements that contribute to the functional asymmetries of the two ubiquinone(10) binding pockets in the reaction center of Rhodobacter capsulatus, we targeted the L212Glu-L213Asp (near Q(B)) and the M246Ala-M247Ala (near Q(A)) pairs of symmetry-related residues for site-specific mutagenesis. We have constructed site-specific mutants that eliminate the sequence differences at these positions (L212Glu-L213Asp-->Ala-Ala or M246Ala-M247Ala-->Glu-Asp), and have reversed that asymmetry by constructing a quadruple-mutant strain, 'RQ' (L212Glu-L213Asp-M246Ala-M247Ala-->Ala-Ala-Glu-Asp). The mutations were designed to change the charge distribution in the quinone-binding region of the reaction center; none of the strains is capable of photosynthetic growth. In photocompetent phenotypic revertants of the RQ strain, second-site mutations which affect Q(B) function are coupled to mutations in the Q(A) site which restore an Ala or substitute a Tyr at the M247 site; one strain carries an additional Met-->Leu substitution at M260 near Q(A). All of the RQ revertants retain the engineered M246Ala-->Glu mutation in the Q(A) site as well as the L212Ala-L213Ala mutations in the Q(B) site. Kinetic characterization of the RQ revertants will give us an idea of what structural and functional elements are important for restoring efficiency to electron and proton transfer pathways in the RQ RC, which is far from native. To date, these preliminary results underscore the importance of an asymmetric distribution of polar amino acids in the quinone binding pockets and its influence on the functional properties of the reaction center. C1 Argonne Natl Lab, Ctr Mech Biol & Biotechnol, Argonne, IL 60439 USA. RP Hanson, DK (reprint author), Argonne Natl Lab, Ctr Mech Biol & Biotechnol, 9700 S Cass Ave, Argonne, IL 60439 USA. NR 24 TC 8 Z9 8 U1 0 U2 0 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0166-8595 J9 PHOTOSYNTH RES JI Photosynth. Res. PD MAR PY 1998 VL 55 IS 2-3 BP 275 EP 280 DI 10.1023/A:1005901510444 PG 6 WC Plant Sciences SC Plant Sciences GA 105MG UT WOS:000075076900022 ER PT J AU Lidorikis, E Busch, K Li, QM Chan, CT Soukoulis, CM AF Lidorikis, E Busch, K Li, QM Chan, CT Soukoulis, CM TI Wave propagation in linear and nonlinear structures SO PHYSICA D LA English DT Article; Proceedings Paper CT International Conference on Fluctuations, Nonlinearity and Disorder CY SEP 30-OCT 04, 1996 CL HERAKLION, CRETE, GREECE ID OPTICAL-RESPONSE; MULTILAYER STRUCTURES; SCHRODINGER-EQUATION; BISTABILITY; SUPERLATTICES AB We consider the general problem of electromagnetic wave propagation through a one-dimensional system consisting of a nonlinear medium sandwiched between two linear structures. Special emphasis is given to systems where the latter comprise Bragg-reflectors. We obtain an exact expression for the nonlinear response of such dielectric superlattices when the nonlinear impurity is very thin, or in thc delta-function limit. We find that both the switching-up and switching-down intensities of the bistable response can be made very lour, when the frequency of the incident wave matches that of the impurity mode of the structure, Numerical results for it nonlinear layer of finite width display qualitatively similar behavior, thus confirming the usefulness of the simpler delta-function model, In addition, an analytical solution for the resonance states of an infinitely extended finite width superlattice with a finite width nonlinear impurity is presented. Finally, we investigate the adequacy of the Kronig-Penney delta-function model in describing the electromagnetic wave propagation in periodic structures consistent of thin layers of materials with an intensity-dependent dielectric constant. Copyright (C) 1998 Elsevier Science B.V. C1 US DOE, Ames Lab, Ames, IA 50011 USA. Iowa State Univ Sci & Technol, Dept Phys & Astron, Ames, IA 50011 USA. Univ Karlsruhe, Inst Theorie Kondesierten Mat, D-76128 Karlsruhe, Germany. Hong Kong Univ Sci & Technol, Dept Phys, Kowloon, Hong Kong. RP Soukoulis, CM (reprint author), US DOE, Ames Lab, Ames, IA 50011 USA. RI Soukoulis, Costas/A-5295-2008 NR 21 TC 6 Z9 6 U1 0 U2 4 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0167-2789 J9 PHYSICA D JI Physica D PD MAR 1 PY 1998 VL 113 IS 2-4 BP 346 EP 365 DI 10.1016/S0167-2789(97)00289-3 PG 20 WC Mathematics, Applied; Physics, Multidisciplinary; Physics, Mathematical SC Mathematics; Physics GA ZC388 UT WOS:000072573000033 ER PT J AU Bruch, R Safronova, UI Shlyaptseva, AS Nilsen, J Schneider, D AF Bruch, R Safronova, UI Shlyaptseva, AS Nilsen, J Schneider, D TI Theoretical analysis of the doubly excited 3lnl ' states of sodiumlike copper SO PHYSICA SCRIPTA LA English DT Article ID DOUBLE-ELECTRON CAPTURE; LASER PLASMA SOURCE; IONS; COLLISIONS; SPECTRA; AUGER AB Energy levels, radiative transition probabilities and autoionization rates for CuXIX including the 1s(2)2s(2)2p(5)3lnl' (n=3 divided by 8, l'less than or equal to n-1) and 1s(2)2s(2)2p(6)3lnl' (n=3 divided by 4, l'less than or equal to n-1) doubly excited states were calculated using the multi-configurational Hartree-Fock method (Cowan code). Contributions of relativistic effects were discussed in comparison with data obtained by the multi-configurational Dirac-Fock method (YODA code). Application of the theoretical data for interpretation of experimental spectra obtained by double-electron capture in slow ion-atom collisions is discussed. C1 Russian Acad Sci, Inst Spect, Troitsk 142092, Russia. Univ Nevada, Dept Phys, Reno, NV 89557 USA. Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. RP Safronova, UI (reprint author), Univ Notre Dame, Dept Phys, Notre Dame, IN 46556 USA. NR 15 TC 4 Z9 4 U1 1 U2 1 PU ROYAL SWEDISH ACAD SCIENCES PI STOCKHOLM PA PUBL DEPT BOX 50005, S-104 05 STOCKHOLM, SWEDEN SN 0281-1847 J9 PHYS SCRIPTA JI Phys. Scr. PD MAR PY 1998 VL 57 IS 3 BP 334 EP 344 DI 10.1088/0031-8949/57/3/005 PG 11 WC Physics, Multidisciplinary SC Physics GA ZC257 UT WOS:000072558700005 ER PT J AU Wehner, MU Ulm, MH Chemla, DS Wegener, M AF Wehner, MU Ulm, MH Chemla, DS Wegener, M TI Coherent dynamics in semiconductors on a 10 fs timescale: Coherent control of scattering processes SO PHYSICA STATUS SOLIDI B-BASIC RESEARCH LA English DT Article; Proceedings Paper CT 5th International Workshop on Nonlinear Optics and Excitation Kinetics in Semiconductors (NOEKS 5) CY SEP 01-05, 1997 CL GRAAL MURITZ, GERMANY ID PHONON QUANTUM KINETICS; BULK GAAS; BAND AB In the quantum kinetics regime, i.e. a few tens of femtoseconds after optical excitation: scattering processes in semiconductors are not completed, thus relaxation has: not yet become irreversible. This opens the fascinating possibility of actually reversing or enhancing uncompleted scattering-events. We present here nem recent experiments performed on the model semiconductor GaAs, where me use attosecond timescale coherent control to suppress or amplify the phonon oscillations. C1 Univ Karlsruhe, Inst Angew Phys, D-76128 Karlsruhe, Germany. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. RP Wehner, MU (reprint author), Univ Karlsruhe, Inst Angew Phys, Kaiserstr 12, D-76128 Karlsruhe, Germany. EM martin.wegener@physik.uni-karlsruhe.de RI Wegener, Martin/S-5456-2016 NR 13 TC 5 Z9 5 U1 0 U2 1 PU WILEY-V C H VERLAG GMBH PI BERLIN PA MUHLENSTRASSE 33-34, D-13187 BERLIN, GERMANY SN 0370-1972 J9 PHYS STATUS SOLIDI B JI Phys. Status Solidi B-Basic Res. PD MAR PY 1998 VL 206 IS 1 BP 281 EP 291 DI 10.1002/(SICI)1521-3951(199803)206:1<281::AID-PSSB281>3.0.CO;2-X PG 11 WC Physics, Condensed Matter SC Physics GA ZD262 UT WOS:000072667600036 ER PT J AU Ellmers, C Hofmann, M Ruhle, WW Girndt, A Jahnke, F Chow, WW Knorr, A Koch, SW Hanke, C Korte, L Hoyler, C AF Ellmers, C Hofmann, M Ruhle, WW Girndt, A Jahnke, F Chow, WW Knorr, A Koch, SW Hanke, C Korte, L Hoyler, C TI Gain spectra of an (InGa)As single quantum well laser diode SO PHYSICA STATUS SOLIDI B-BASIC RESEARCH LA English DT Article; Proceedings Paper CT 5th International Workshop on Nonlinear Optics and Excitation Kinetics in Semiconductors (NOEKS 5) CY SEP 01-05, 1997 CL GRAAL MURITZ, GERMANY ID OPTICAL-GAIN; GAAS AB A new method using the broad spectrum of a 10 fs Ti:sapphire laser is demonstrated for measuring the gain spectra of semiconductor lasers with high and quantitative accuracy. Results are shown for an edge-emitting ridge-waveguide In0.05Ga0.95As single quantum well (SQW) laser. The device is studied from the absorption regime up to the strong gain regime recording both, TE and TM polarizations. The experiments are compared to the predictions of a microscopic model based on the semiconductor Bloch equations including microscopic scattering and dephasing terms. A very good quantitative agreement is obtained. C1 Fachbereich Phys, D-35032 Marburg, Germany. Zentrum Mat Wissensch, D-35032 Marburg, Germany. Sandia Natl Labs, Albuquerque, NM 87185 USA. Siemens AG, Zent Abt Forsch & Entwicklung, D-81739 Munich, Germany. RP Ellmers, C (reprint author), Fachbereich Phys, Renthof 5, D-35032 Marburg, Germany. NR 20 TC 12 Z9 12 U1 0 U2 1 PU WILEY-V C H VERLAG GMBH PI BERLIN PA MUHLENSTRASSE 33-34, D-13187 BERLIN, GERMANY SN 0370-1972 J9 PHYS STATUS SOLIDI B JI Phys. Status Solidi B-Basic Res. PD MAR PY 1998 VL 206 IS 1 BP 407 EP 412 DI 10.1002/(SICI)1521-3951(199803)206:1<407::AID-PSSB407>3.0.CO;2-X PG 6 WC Physics, Condensed Matter SC Physics GA ZD262 UT WOS:000072667600051 ER PT J AU Fritsch, M Kao, CC Hamalainen, K Gang, O Forster, E Deutsch, M AF Fritsch, M Kao, CC Hamalainen, K Gang, O Forster, E Deutsch, M TI Evolution of the Cu K alpha(3,4) satellites from threshold to saturation SO PHYSICAL REVIEW A LA English DT Article ID X-RAY-ABSORPTION; K-ALPHA; SYNCHROTRON RADIATION; SHELL PHOTOIONIZATION; ARGON; SPECTRA; TRANSITION; EXCITATION; IONIZATION; COPPER AB Photoexcited Cu K alpha(3,4) satellite spectra were measured as a function of excitation energy, from threshold at similar to 10.010 keV to saturation at similar to 11 keV. A two-regime behavior is found, where in the near-threshold regime (TR) both the shape and the intensity of the spectrum vary. In the higher-energy regime (GR) only the intensity varies but not the shape. The GR spectra are well described by relativistic Dirac-Fock calculations. The analytic Thomas model, applicable in this adiabatic regime, does not agree well with the measured intensity variation with excitation energy. The continuous intensity rise from zero at threshold confirms the shake theory prediction of a pure shake-off process for inner-shell, medium-Z atom satellites. The thresholds for the individual spectral features, the overall shape variation, and the variations of the individual lines in the TR regime are determined, and discussed. C1 Bar Ilan Univ, Dept Phys, IL-52900 Ramat Gan, Israel. Brookhaven Natl Lab, NSLS, Upton, NY 11973 USA. Univ Helsinki, Dept Phys, FIN-00014 Helsinki, Finland. Univ Jena, Inst Opt & Quantum Elect, D-07743 Jena, Germany. RP Fritsch, M (reprint author), Bar Ilan Univ, Dept Phys, IL-52900 Ramat Gan, Israel. RI Hamalainen, Keijo/A-3986-2010 OI Hamalainen, Keijo/0000-0002-9234-9810 NR 58 TC 43 Z9 43 U1 0 U2 3 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1050-2947 J9 PHYS REV A JI Phys. Rev. A PD MAR PY 1998 VL 57 IS 3 BP 1686 EP 1697 DI 10.1103/PhysRevA.57.1686 PG 12 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA ZB155 UT WOS:000072441900034 ER PT J AU Pieksma, M Havener, CC AF Pieksma, M Havener, CC TI Low-energy electron capture by B4+ ions from hydrogen atoms SO PHYSICAL REVIEW A LA English DT Article ID MERGED-BEAMS; COLLISION ENERGIES; MULTICHARGED IONS; H-ATOMS AB Using a merged-beam technique, the absolute, total electron-capture cross section has been measured for collisions of B4+ ions with hydrogen (deuterium) atoms at collision energies between 60 and 1200 eV/amu. The data are compared to two semiclassical coupled-channel molecular-orbital calculations, which differ by 30% with respect to each other over the entire energy range, and to two previous measurements at higher energies that differ by up to a factor of 2. C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Pieksma, M (reprint author), Univ Utrecht, Debye Inst, Dept Atom & Interface Phys, POB 80000, NL-3508 TA Utrecht, Netherlands. RI Institute (DINS), Debye/G-7730-2014 NR 19 TC 7 Z9 7 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1050-2947 J9 PHYS REV A JI Phys. Rev. A PD MAR PY 1998 VL 57 IS 3 BP 1892 EP 1894 DI 10.1103/PhysRevA.57.1892 PG 3 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA ZB155 UT WOS:000072441900055 ER PT J AU Samson, JAR Stolte, WC He, ZX Cutler, JN Lu, Y Bartlett, RJ AF Samson, JAR Stolte, WC He, ZX Cutler, JN Lu, Y Bartlett, RJ TI Double photoionization of helium SO PHYSICAL REVIEW A LA English DT Article ID IONIZATION CROSS-SECTIONS; PHOTON DOUBLE IONIZATION; ELECTRON-BEAM TIME; SINGLE-PHOTON; RARE-GASES; HE; THRESHOLD; ENERGIES; IMPACT; RATIO AB The cross sections for double photoionization of helium and thr ratios of double to single ionization have been measured from the double-ionization threshold to 820 eV. The results are in very good agreement with several recent calculations. C1 Univ Nebraska, Dept Phys & Astron, Lincoln, NE 68588 USA. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Samson, JAR (reprint author), Univ Nebraska, Dept Phys & Astron, Lincoln, NE 68588 USA. NR 43 TC 148 Z9 148 U1 1 U2 6 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1050-2947 J9 PHYS REV A JI Phys. Rev. A PD MAR PY 1998 VL 57 IS 3 BP 1906 EP 1911 DI 10.1103/PhysRevA.57.1906 PG 6 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA ZB155 UT WOS:000072441900057 ER PT J AU Cerf, NJ Adami, C Kwiat, PG AF Cerf, NJ Adami, C Kwiat, PG TI Optical simulation of quantum logic SO PHYSICAL REVIEW A LA English DT Article ID BEAM SPLITTER; COMPUTATION; UNIVERSAL; GATES AB A constructive method for simulating small-scale quantum circuits by use of linear optical devices is presented. It relies on the representation of several quantum bits by a single photon, and on the implementation of universal quantum gates using simple optical components (beam splitters, phase shifters, etc.). This suggests that the optical realization of small quantum networks with present-day quantum optics technology is a reasonable goal. This technique could be useful for demonstrating basic concepts of simple quantum algorithms or error-correction schemes. The optical analog of a nontrivial three-bit quantum circuit is presented as an illustration. [S1050-2947(98)50403-9]. C1 CALTECH, WK Kellogg Radiat Lab, Pasadena, CA 91125 USA. Univ Calif Los Alamos Natl Lab, Div Phys, Los Alamos, NM 87545 USA. RP Cerf, NJ (reprint author), CALTECH, WK Kellogg Radiat Lab, Pasadena, CA 91125 USA. RI Adami, Christoph/A-5181-2009; Adami, Christoph/A-9675-2011 OI Adami, Christoph/0000-0002-2915-9504 NR 19 TC 120 Z9 121 U1 1 U2 7 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1050-2947 J9 PHYS REV A JI Phys. Rev. A PD MAR PY 1998 VL 57 IS 3 BP R1477 EP R1480 DI 10.1103/PhysRevA.57.R1477 PG 4 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA ZB155 UT WOS:000072441900003 ER PT J AU Kukk, E Wils, A Berrah, N Langer, B Bozek, JD Nayadin, O Alsherhi, M Farhat, A Cubaynes, D AF Kukk, E Wils, A Berrah, N Langer, B Bozek, JD Nayadin, O Alsherhi, M Farhat, A Cubaynes, D TI Angle-resolved two-dimensional mapping of electron emission following Cl 2p excitations in the HCl molecule SO PHYSICAL REVIEW A LA English DT Article ID AUGER DECAY; ANGULAR-DISTRIBUTION; DCL MOLECULES; STATES; SPECTROSCOPY; SPECTRUM; ATOMS; CO AB Angle-resolved Anger and valence photoelectron spectra of HCl were measured over a 14-eV-wide photon-energy range across the Cl 2p ionization thresholds. Auger decay spectra of dissociative core-excited states were observed to change with photon energy, reflecting a change in the rate of dissociation. Anger electron spectra at the first Rydberg states were analyzed and the evolution of the resonant Anger to the normal Auger decay distorted by postcollision interaction was examined. Valence photoionization channels were shown to resonate strongly at the photon energies of the core-to-Rydberg excitations. Angular distributions of the photo-and Anger electron lines were derived; strong fluctuations of the beta values of the 2 pi photoline were observed at some Rydberg resonances. Anisotropy of the Auger decay at the sigma* and Rydberg excitations was found to be different, with the latter showing uniformly negative beta values. [S1050-2947(98)50203-X]. C1 Western Michigan Univ, Dept Phys, Kalamazoo, MI 49008 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. Max Planck Gesell, Fritz Haber Inst, D-14195 Berlin, Germany. Univ Paris Sud, Lab Spect Atom & Ion, CNRS, URA 775, F-91405 Orsay, France. RP Kukk, E (reprint author), Western Michigan Univ, Dept Phys, Kalamazoo, MI 49008 USA. RI Bozek, John/E-4689-2010; Langer, Burkhard/A-6504-2013; Bozek, John/E-9260-2010 OI Bozek, John/0000-0001-7486-7238 NR 19 TC 18 Z9 18 U1 0 U2 2 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1050-2947 J9 PHYS REV A JI Phys. Rev. A PD MAR PY 1998 VL 57 IS 3 BP R1485 EP R1488 DI 10.1103/PhysRevA.57.R1485 PG 4 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA ZB155 UT WOS:000072441900005 ER PT J AU Qiu, YH Tang, JZ Burgdorfer, J Wang, JY AF Qiu, YH Tang, JZ Burgdorfer, J Wang, JY TI Double photoionization of helium from threshold to high energies SO PHYSICAL REVIEW A LA English DT Article ID DOUBLE-IONIZATION; CROSS-SECTIONS; PHOTON IMPACT; HE; SINGLE; ELECTRONS AB We present accurate calculations for the single and double photoionization of helium from the threshold to the high-energy limit. At low and intermediate energies, we use the ab initio hyperspherical close-coupling method, which is extended up to 1 keV by introducing an energy-dependent reaction region. At high energies we employ an accurate Hylleraas initial state and a 3C correlated final-state wave function. The 3C wave function is shown to be correct to leading order in Z/k. We find good agreement with recent experiments over the entire energy range. The two calculations merge at similar to 1 keV to within 5 %. [S1050-2947(98)50603-8]. C1 Univ Tennessee, Dept Phys, Knoxville, TN 37996 USA. Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. Tulane Univ, Dept Phys, New Orleans, LA 70118 USA. RP Qiu, YH (reprint author), Univ Tennessee, Dept Phys, Knoxville, TN 37996 USA. NR 24 TC 28 Z9 28 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1050-2947 J9 PHYS REV A JI Phys. Rev. A PD MAR PY 1998 VL 57 IS 3 BP R1489 EP R1492 DI 10.1103/PhysRevA.57.R1489 PG 4 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA ZB155 UT WOS:000072441900006 ER PT J AU Lundin, U Fast, L Nordstrom, L Johansson, B Wills, JM Eriksson, O AF Lundin, U Fast, L Nordstrom, L Johansson, B Wills, JM Eriksson, O TI Transition-metal dioxides with a bulk modulus comparable to diamond SO PHYSICAL REVIEW B LA English DT Article ID HIGH-PRESSURE; MODEL AB Recently it has been reported that a high-pressure cubic phase of ruthenium dioxide has an unusually large bulk modulus, and consequently is a most interesting candidate as a very hard material. Based on ab initio calculations it is shown that the high bulk modulus is a result of a strong covalent bonding between ruthenium d states and oxygen p states in combination with the favorable geometry of the orbitals in the fluorite structure. In addition an even higher bulk modulus is predicted for the isoelectronic and isostructural compound OsO2. C1 Univ Uppsala, Dept Phys, Condensed Matter Theory Grp, S-75121 Uppsala, Sweden. Univ Calif Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. RP Lundin, U (reprint author), Univ Uppsala, Dept Phys, Condensed Matter Theory Grp, Box 530, S-75121 Uppsala, Sweden. RI Eriksson, Olle/E-3265-2014 OI Eriksson, Olle/0000-0001-5111-1374 NR 10 TC 47 Z9 48 U1 0 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 MAR 1 PY 1998 VL 57 IS 9 BP 4979 EP 4982 DI 10.1103/PhysRevB.57.4979 PG 4 WC Physics, Condensed Matter SC Physics GA ZA389 UT WOS:000072358600005 ER PT J AU Zharnitsky, V Mitkov, I Levi, M AF Zharnitsky, V Mitkov, I Levi, M TI Parametrically forced sine-Gordon equation and domain wall dynamics in ferromagnets SO PHYSICAL REVIEW B LA English DT Article ID EASY-PLANE; SOLITONS; CHAIN; KINKS AB A parametrically forced sine-Gordon equation with a fast periodic mean-zero forcing is considered. It is shown that pi kinks represent a class of solitary-wave solutions of the equation. This result is applied to quasi-one-dimensional ferromagnets with an easy-plane anisotropy, in a rapidly oscillating magnetic field. In this case the pi-kink solution we have introduced corresponds to the uniform "true" domain-wall motion, since the magnetization directions on opposite sides of the wall are antiparallel. In contrast to previous work, no additional anisotropy is required to obtain a true domain wall. Numerical simulations showed good qualitative agreement with the theory. C1 Brown Univ, Div Appl Math, Providence, RI 02912 USA. Univ Calif Los Alamos Natl Lab, Div Appl Theoret Phys, Los Alamos, NM 87545 USA. Univ Calif Los Alamos Natl Lab, Ctr Nonlinear Studies, Los Alamos, NM 87545 USA. Rensselaer Polytech Inst, Dept Math Sci, Troy, NY 12180 USA. RP Zharnitsky, V (reprint author), Brown Univ, Div Appl Math, Providence, RI 02912 USA. NR 20 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 MAR 1 PY 1998 VL 57 IS 9 BP 5033 EP 5035 DI 10.1103/PhysRevB.57.5033 PG 3 WC Physics, Condensed Matter SC Physics GA ZA389 UT WOS:000072358600019 ER PT J AU Chmaissem, O Jorgensen, JD Shaked, H Ikeda, S Maeno, Y AF Chmaissem, O Jorgensen, JD Shaked, H Ikeda, S Maeno, Y TI Thermal expansion and compressibility of Sr2RuO4 SO PHYSICAL REVIEW B LA English DT Article ID NEUTRON POWDER DIFFRACTION; PRESSURE; SUPERCONDUCTIVITY; TEMPERATURE AB The thermal expansion and compressibility of Sr2RuO4 have been investigated using neutron-powder diffraction. Our results confirm that the temperature dependence of the Ru-O2 apical bond length is linear with no structural anomaly (reported previously) corresponding to the metal-to-insulator transition. The response of the crystal lattice of Sr2RuO4 to pressure is similar to that of the superconducting cuprate (La,Sr)(2)CuO4. However, the Ru-O2 apical bond is much harder to compress than the corresponding Cu-O2 bond. C1 Argonne Natl Lab, Sci & Technol Ctr Superconductiv, Div Sci Mat, Argonne, IL 60439 USA. Ben Gurion Univ Negev, Dept Phys, IL-84105 Beer Sheva, Israel. Kyoto Univ, Dept Phys, Kyoto 60601, Japan. RP Chmaissem, O (reprint author), Argonne Natl Lab, Sci & Technol Ctr Superconductiv, Div Sci Mat, Argonne, IL 60439 USA. RI Ikeda, Shinichi/I-5829-2012 OI Ikeda, Shinichi/0000-0003-2134-7786 NR 15 TC 31 Z9 32 U1 1 U2 6 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 MAR 1 PY 1998 VL 57 IS 9 BP 5067 EP 5070 DI 10.1103/PhysRevB.57.5067 PG 4 WC Physics, Condensed Matter SC Physics GA ZA389 UT WOS:000072358600028 ER PT J AU Darling, TW Migliori, A Moshopoulou, EG Trugman, SA Neumeier, JJ Sarrao, JL Bishop, AR Thompson, JD AF Darling, TW Migliori, A Moshopoulou, EG Trugman, SA Neumeier, JJ Sarrao, JL Bishop, AR Thompson, JD TI Measurement of the elastic tensor of a single crystal of La0.83Sr0.17MnO3 and its response to magnetic fields SO PHYSICAL REVIEW B LA English DT Article ID LA1-XSRXMNO3; CA AB We have measured the (cubic-lattice-approximation) elastic moduli of optical melt-zone-grown single-crystal La0.83Sr0.17MnO3 using resonant ultrasound spectroscopy. We observe the structural transition at 285 K to be hysteretic in the ambient (almost zero) magnetic field. A second elastic feature at the ferromagnetic T-c 265 K, a third at 252 K, and a fourth in magnetic field at 220 K are also observed in this sample, which sits in a particularly complex region in composition space. The application of a magnetic field changes some of the elastic moduli significantly between 220 K and 285 K. By determining the complete elastic tensor, we identify which cubic crystallographic distortions are strongest at each elastic anomaly and which are sensitive to magnetic field. We also determine which bonds play a role in each of the observed features. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Darling, TW (reprint author), Univ Calif Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. NR 14 TC 65 Z9 66 U1 0 U2 6 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 MAR 1 PY 1998 VL 57 IS 9 BP 5093 EP 5097 DI 10.1103/PhysRevB.57.5093 PG 5 WC Physics, Condensed Matter SC Physics GA ZA389 UT WOS:000072358600034 ER PT J AU Shastri, A Majzoub, EH Borsa, F Gibbons, PC Kelton, KF AF Shastri, A Majzoub, EH Borsa, F Gibbons, PC Kelton, KF TI H-1 NMR study of hydrogen in quasicrystalline Ti0.45-xVxZr0.38Ni0.17 SO PHYSICAL REVIEW B LA English DT Article ID QUASI-CRYSTALS; SCANDIUM; METAL; DIFFUSION; SYSTEMS; PROTON AB H-1 nuclear-magnetic-resonance (NMR) spectra and spin-lattice relaxation rates (RI) were studied in the hydrogenated Ti0.45-xVxZr0.38Ni0.17 quasicrystal for x=0.00, 0.02, and a hydrogen-to-metal-atom ratio (H/M)=1.88. NMR measurements were made from 4 to 550 K at resonance frequencies of 8, 18, 55, and 200 MHz. Theoretical H-1 second-moment values (M-2) were calculated based on Bergman and Mackay cluster models and compared with experimental M-2 values. The R-1 data reveal a distribution of activation energies for the H-1 diffusion through the quasilattice; the distribution is insensitive to the vanadium concentration, x. Low-temperature R-1 data reveal an additional low-temperature relaxation mechanism that is not yet well understood. C1 US DOE, Ames Lab, Ames, IA 50011 USA. Iowa State Univ Sci & Technol, Dept Phys & Astron, Ames, IA 50011 USA. Washington Univ, Dept Phys, St Louis, MO 63130 USA. Univ Pavia, Dipartimento Fis, I-27100 Pavia, Italy. RP Shastri, A (reprint author), Med Univ S Carolina, Dept Radiol, 107 Ashley Ave, Charleston, SC 29425 USA. NR 27 TC 24 Z9 24 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 MAR 1 PY 1998 VL 57 IS 9 BP 5148 EP 5153 DI 10.1103/PhysRevB.57.5148 PG 6 WC Physics, Condensed Matter SC Physics GA ZA389 UT WOS:000072358600041 ER PT J AU Keavney, DJ Fullerton, EE Li, DQ Sowers, CH Bader, SD Goodman, K Tobin, JG Carr, R AF Keavney, DJ Fullerton, EE Li, DQ Sowers, CH Bader, SD Goodman, K Tobin, JG Carr, R TI Enhanced Co orbital moments in Co-rare-earth permanent-magnet films SO PHYSICAL REVIEW B LA English DT Article ID RAY CIRCULAR-DICHROISM; SUM-RULE; MAGNETIZATION; TRANSITION; ABSORPTION; ANISOTROPY; ENERGY; SPIN; INTERMETALLICS; DEPENDENCE AB Soft x-ray magnetic circular dichroism (MCD) data were collected at the Co L edges from a series of epitaxial R-Co (R=Pr, Nd, Sm, Dy, and Ho) intermetallic compound films grown by sputter deposition. The Co orbital-to-spin moment ratios were extracted from the data using the MCD sum rules. An enhanced Co orbital moment, as compared to that of bulk hcp-Co, is seen in all but one of the films: The enhancement is dependent on both the average R-Co bond length and on the R species. These results suggest that a significant transition-metal (TM) orbital moment is the origin of the TM sublattice contribution to the magnetocrystalline anisotropy energy in R-TM compounds. C1 Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. Univ Calif Lawrence Livermore Natl Lab, Dept Chem & Mat Sci, Livermore, CA 94550 USA. Stanford Synchrotron Radiat Lab, Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. RP Keavney, DJ (reprint author), Argonne Natl Lab, Div Mat Sci, 9700 S Cass Ave, Argonne, IL 60439 USA. RI Bader, Samuel/A-2995-2013; Fullerton, Eric/H-8445-2013; Tobin, James/O-6953-2015 OI Fullerton, Eric/0000-0002-4725-9509; NR 29 TC 16 Z9 16 U1 1 U2 11 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 MAR 1 PY 1998 VL 57 IS 9 BP 5291 EP 5297 DI 10.1103/PhysRevB.57.5291 PG 7 WC Physics, Condensed Matter SC Physics GA ZA389 UT WOS:000072358600061 ER PT J AU Chakarian, V Idzerda, YU Chen, CT AF Chakarian, V Idzerda, YU Chen, CT TI Absolute helicity-dependent photoabsorption cross sections of Fe thin films and quantitative evaluation of magnetic-moment determination SO PHYSICAL REVIEW B LA English DT Article ID RAY CIRCULAR-DICHROISM; SUM-RULES; ABSORPTION; NI; TRANSMISSION; EDGES; METALS; CO AB Energy and helicity-dependent absolute photoabsorption cross sections at the Fe L-2,L-3 edge, measured in transmission from a supported ultrathin Fe film, are presented. These cross sections and semiempirical total-electron-yield (TEY) equations are used to show that the effects of saturation/self-absorption in the TEY spectra, as reflected in the quantitative evaluation of magnetic moments, can be quite severe. These conclusions are confirmed by directly comparing the data obtained simultaneously by TEY and transmission. C1 USN, Res Lab, Washington, DC 20375 USA. AT&T Bell Labs, Murray Hill, NJ 07974 USA. RP Chakarian, V (reprint author), Brookhaven Natl Lab, Bldg 510E, Upton, NY 11973 USA. NR 23 TC 52 Z9 52 U1 0 U2 4 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 MAR 1 PY 1998 VL 57 IS 9 BP 5312 EP 5315 DI 10.1103/PhysRevB.57.5312 PG 4 WC Physics, Condensed Matter SC Physics GA ZA389 UT WOS:000072358600063 ER PT J AU Schmeltzer, D Bishop, AR AF Schmeltzer, D Bishop, AR TI Magnetic-field dependence of coupled Luttinger chains SO PHYSICAL REVIEW B LA English DT Article ID HUBBARD-MODEL; BOSONIZATION; LIQUIDS AB The model of two coupled Luttinger chains in the presence of a magnetic field is investigated for weak and strong magnetic field strengths. For magnetic fields that are close to the commensurate wave vector condition Q approximate to 2 K-F (with K-F the Fermi wave vector), incoherent tunneling between the chains takes place. Under these conditions, we propose that the incoherent non-Fermi-liquid Anderson fixed point is realized. Implications for the normal-state behavior of organic and cuprate superconductors are discussed. C1 CUNY City Coll, Dept Phys, New York, NY 10031 USA. Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. RP Schmeltzer, D (reprint author), CUNY City Coll, Dept Phys, New York, NY 10031 USA. NR 23 TC 2 Z9 2 U1 0 U2 0 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 MAR 1 PY 1998 VL 57 IS 9 BP 5419 EP 5424 DI 10.1103/PhysRevB.57.5419 PG 6 WC Physics, Condensed Matter SC Physics GA ZA389 UT WOS:000072358600077 ER PT J AU Gray, KE AF Gray, KE TI Vortex correlation lengths and bundle sizes from voltage noise in YBa2Cu3O7 SO PHYSICAL REVIEW B LA English DT Article ID LATTICE-MELTING TRANSITION; FLUX-FLOW NOISE; HIGH-TEMPERATURE SUPERCONDUCTORS; FILMS AB Voltage noise is one way to estimate flux-bundle sizes in superconductors undergoing Aux creep. Modeling such data from epitaxial films of YBa2CU3O7. we show that at high temperatures, the bundle size grows with the c-axis correlation length of pancake vortices (residing in the Cu-O planes), while at low temperatures, flux creep is consistent with vortex-line bundles which are larger than a minimum size. The separation of these regimes is roughly at the vortex-lattice melting line, implying that a large c-axis correlation length is needed for vortex-lattice freezing. C1 Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. RP Gray, KE (reprint author), Argonne Natl Lab, Div Mat Sci, 9700 S Cass Ave, Argonne, IL 60439 USA. NR 26 TC 12 Z9 12 U1 0 U2 0 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 MAR 1 PY 1998 VL 57 IS 9 BP 5524 EP 5528 DI 10.1103/PhysRevB.57.5524 PG 5 WC Physics, Condensed Matter SC Physics GA ZA389 UT WOS:000072358600090 ER PT J AU Cai, ZX Sen, S AF Cai, ZX Sen, S TI Domain structure in two-dimensional lattices with randomly distributed pinning centers: Application to type-II superconductors SO PHYSICAL REVIEW B LA English DT Article ID GRAPHITE-INTERCALATION COMPOUNDS; MOLECULAR-DYNAMICS; SIMULATION; MODEL AB We present a molecular-dynamics-based study on certain structural features of disordered two-dimensional lattices of N particles with screened Coulomb interactions which are placed on rigid substrates with N-p randomly distributed Gaussian pinning centers. We find that over a wide temperature range, for N-p=N and for various pinning intensities A(p), the lattice structures are typically described by domains of triangular-latticelike regions punctuated by domains of clustered topological defects. Our calculations reveal that as A(p) increases, sizable triangular-lattice-like regions coexist with increased topological defect densities. This result suggests that the particles remain correlated even at strong pinning regimes. Its implications are discussed in relation to recent experiments on heavy-ion-irradiated high-temperature superconductors and the assumptions used in various flux pinning theories of type-II superconductors. C1 Brookhaven Natl Lab, Div Mat Sci, Upton, NY 11973 USA. SUNY Buffalo, Dept Phys, Buffalo, NY 14260 USA. RP Cai, ZX (reprint author), Brookhaven Natl Lab, Div Mat Sci, Upton, NY 11973 USA. NR 24 TC 2 Z9 2 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 MAR 1 PY 1998 VL 57 IS 9 BP 5529 EP 5534 DI 10.1103/PhysRevB.57.5529 PG 6 WC Physics, Condensed Matter SC Physics GA ZA389 UT WOS:000072358600091 ER PT J AU Staub, U Soderholm, L Skanthakumar, S Pattison, P Conder, K AF Staub, U Soderholm, L Skanthakumar, S Pattison, P Conder, K TI Structural disorder in the Pb2Sr2Y1-xCaxCu3O8+delta cuprates SO PHYSICAL REVIEW B LA English DT Article ID CRYSTAL NEUTRON-DIFFRACTION; ELECTRON-MICROSCOPY; MAGNETIC-PROPERTIES; POWDER DIFFRACTION; OXIDATION-STATE; OXYGEN; ND; IONS AB High-resolution powder x-ray-diffraction results on Pb2Sr2Y1-xCaxCu3O8+delta are presented. Assuming an orthorhombic cell with Cmmm symmetry, the reflections that index with h and l simultaneous nonzero are observed to be distinctly broader than the other reflections. A model is presented that is able to explain quantitatively and qualitatively the relative widths of the different hkl reflections. The widths of the reflections are found to be independent of the doping level. The model employed is based on anisotropic distributions of the d spacings within the (a,c) plane, corresponding to a fluctuation of the beta angle around 90 degrees that occurs as a result of oxygen nonstoichiometry. The distortions may be related to the incommensurable modulation along the b direction in the structurally similar (Bi/Pb)(2)Sr-2(Ca/Y)Cu2O8+delta compounds. At elevated temperatures, a disorder-order phase transition (T-do=240 degrees C) is observed. At temperatures above T-do, the structure relaxes to the undistorted average orthorhombic structure. This order-disorder transition results from oxygen diffusion, which sets in at the transition temperature. C1 Paul Scherrer Inst, Swiss Light Source Project, CH-5232 Villigen, Switzerland. Argonne Natl Lab, Div Chem, Argonne, IL 60439 USA. Univ Lausanne, Inst Crystallog, CH-1015 Lausanne, Switzerland. ETH Zurich, Festkorperphys Lab, CH-8093 Zurich, Switzerland. RP Staub, U (reprint author), Paul Scherrer Inst, Swiss Light Source Project, CH-5232 Villigen, Switzerland. RI Staub, Urs/C-4914-2015 NR 27 TC 9 Z9 9 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 MAR 1 PY 1998 VL 57 IS 9 BP 5535 EP 5540 DI 10.1103/PhysRevB.57.5535 PG 6 WC Physics, Condensed Matter SC Physics GA ZA389 UT WOS:000072358600092 ER PT J AU Sullow, S Prasad, I Aronson, MC Sarrao, JL Fisk, Z Hristova, D Lacerda, AH Hundley, MF Vigliante, A Gibbs, D AF Sullow, S Prasad, I Aronson, MC Sarrao, JL Fisk, Z Hristova, D Lacerda, AH Hundley, MF Vigliante, A Gibbs, D TI Structure and magnetic order of EuB6 SO PHYSICAL REVIEW B LA English DT Article ID RARE-EARTH BORIDES; SINGLE-CRYSTALS; HEAT; URU2SI2 AB We present a study of the structural and magnetic properties of single-crystalline EuB6. Temperature-dependent x-ray diffraction found no significant anomalies at the onset of ferromagnetic order. The resistivity, de susceptibility, magnetization, and specific heat prove the crystal to be of extraordinarily high quality. Two ferromagnetic transitions at T-cl=15.3 K and T-c2=12.5 K are observed in all investigated properties. The ordered state displays an unexpected anisotropy, and we derive the magnetic phase diagrams for the three principal cubic directions. We argue that the two magnetic phases are connected by spin reorientation, enabled by a reduction of the crystalline symmetry from cubic. An additional anomaly in the specific heat is observed at low temperatures, which we interpret as arising from the splitting of the Eu ground-state multiplet in internal magnetic fields. C1 Univ Michigan, Dept Phys, Randall Lab 2071, Ann Arbor, MI 48109 USA. Florida State Univ, Natl High Magnet Field Lab, Tallahassee, FL 32310 USA. Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Brookhaven Natl Lab, Upton, NY 11973 USA. RP Sullow, S (reprint author), Univ Michigan, Dept Phys, Randall Lab 2071, Ann Arbor, MI 48109 USA. NR 47 TC 95 Z9 95 U1 1 U2 16 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 MAR 1 PY 1998 VL 57 IS 10 BP 5860 EP 5869 DI 10.1103/PhysRevB.57.5860 PG 10 WC Physics, Condensed Matter SC Physics GA ZB577 UT WOS:000072486500048 ER PT J AU Vigliante, A Christensen, MJ Hill, JP Helgesen, G Sorensen, SA McMorrow, DF Gibbs, D Ward, RCC Wells, MR AF Vigliante, A Christensen, MJ Hill, JP Helgesen, G Sorensen, SA McMorrow, DF Gibbs, D Ward, RCC Wells, MR TI Interplay between structure and magnetism in HoxPr1-x alloys. II. Resonant x-ray magnetic scattering SO PHYSICAL REVIEW B LA English DT Article ID RARE-EARTH SUPERLATTICES; PHASE-TRANSITIONS; HOLMIUM; POLARIZATION; DIFFRACTION AB X-ray-scattering techniques have been used to study the crystal and magnetic structures of HoxPr1-x alloys in the form of thin films. Three distinct crystal structures are found as a function of concentration x, each of which has a characteristic magnetic structure. For x greater than or equal to 0.6 a hexagonal-close-packed phase is found with the magnetic moments ordered in a basal-plane helix, whereas for 0.4 less than or equal to x<0.6 the lattice adopts the crystal structure of bulk Sm with the moments forming a six-layer c-axis antiferromagnet. At Ho concentrations x <0.4 the alloys are double hexagonal-close-packed and remain nonmagnetic down to the lowest temperatures studied. Using x-ray magnetic resonance scattering techniques, we demonstrate that a small, static spin-density wave is induced within the alloy 5d band at both the Pr and Ho sites in both of the magnetically ordered phases. The interpretation of the data is, however, complicated by the fact that the intensity branching ratio L-III/L-II differs from order unity for both Ho and Pr, in contrast to what is predicted from the simplest models of the resonance process. This suggests that an improved treatment of the full exchange interaction between the 5d and 4f moments, such as recently proposed by van Veenendaal, Goedkoop, and Thole [Phys. Rev. Lett. 78, 1162 (1997)], may be needed before quantitative estimates of the magnitudes of the induced 5d moments can be obtained. The temperature dependences of the lattice and magnetic structures, including the lattice constants, magnetic wave vectors, magnetic order parameters, and c-axis coherence lengths, are also characterized. C1 Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. SUNY Stony Brook, Dept Phys, Stony Brook, NY 11794 USA. Riso Natl Lab, Dept Solid State Phys, DK-400 Roskilde, Denmark. Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. Univ Oxford, Dept Phys, Oxford OX1 3PU, England. RP Vigliante, A (reprint author), Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. RI McMorrow, Desmond/C-2655-2008; Hill, John/F-6549-2011 OI McMorrow, Desmond/0000-0002-4947-7788; NR 25 TC 7 Z9 7 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 MAR 1 PY 1998 VL 57 IS 10 BP 5941 EP 5950 DI 10.1103/PhysRevB.57.5941 PG 10 WC Physics, Condensed Matter SC Physics GA ZB577 UT WOS:000072486500057 ER PT J AU Schabel, MC Park, CH Matsuura, A Shen, ZX Bonn, DA Liang, RX Hardy, WN AF Schabel, MC Park, CH Matsuura, A Shen, ZX Bonn, DA Liang, RX Hardy, WN TI Angle-resolved photoemission on untwinned YBa2Cu3O6.95. I. Electronic structure and dispersion relations of surface and bulk bands SO PHYSICAL REVIEW B LA English DT Article ID HIGH-TEMPERATURE SUPERCONDUCTORS; FERMI-SURFACE; GAP ANISOTROPY; VALENCE BANDS; YBA2CU3O7-DELTA; YBA2CU4O8; STATE; BI2SR2CACU2O8+DELTA; SINGULARITY; SYMMETRY AB Angle-resolved photoemission studies of the dispersion relations and polarization dependence of bands in the near E-F region of untwinned YBa2Cu3O7-delta (Y123) single crystals reveal previously unseen details of the electronic structure and significantly expand our understanding of this system. We find that the narrow, intense feature seen along TY in Y123 and YBa2Cu4O8 (Y124) is best explained as a surface termination effect related to the quasi-one-dimensional CuO3 chains, masking underlying electronic states at the Fermi energy. Many of the previously puzzling photoemission results from these materials are readily understood within this context, including the failure to observe a superconducting gap, the weak effect of deoxygenation on the photoemission spectra for delta less than or equal to 0.5, the weak dependence of this feature on Pr doping, and the strong photon energy dependence of the photoemission spectra. Our data, taken in the superconducting state, reveal the bilayer splitting and c-axis dispersion of the CuO2 plane bands. We also find evidence for a one-dimensional chain Fermi surface parallel to the TX direction, but see no indication of the BaO derived "stick" pocket centered on the S point. C1 Stanford Univ, Dept Appl Phys, Stanford, CA 94305 USA. Stanford Univ, Dept Phys, Stanford, CA 94305 USA. Stanford Univ, Stanford Synchrotron Radiat Lab, Stanford, CA 94305 USA. Univ British Columbia, Dept Phys & Astron, Vancouver, BC V6T 1Z1, Canada. RP Schabel, MC (reprint author), Stanford Univ, Dept Appl Phys, Stanford, CA 94305 USA. NR 40 TC 120 Z9 120 U1 0 U2 8 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 MAR 1 PY 1998 VL 57 IS 10 BP 6090 EP 6106 DI 10.1103/PhysRevB.57.6090 PG 17 WC Physics, Condensed Matter SC Physics GA ZB577 UT WOS:000072486500075 ER PT J AU Schabel, MC Park, CH Matsuura, A Shen, ZX Bonn, DA Liang, RX Hardy, WN AF Schabel, MC Park, CH Matsuura, A Shen, ZX Bonn, DA Liang, RX Hardy, WN TI Angle-resolved photoemission on untwinned YBa2Cu3O6.95. II. Determination of Fermi surfaces SO PHYSICAL REVIEW B LA English DT Article ID HIGH-TEMPERATURE SUPERCONDUCTORS; RANGE ANTIFERROMAGNETIC CORRELATIONS; ELECTRONIC-STRUCTURE; GAP ANISOTROPY; BAND-STRUCTURE; VALENCE BANDS; PLANE; BI2SR2CACU2O8+DELTA; COEXISTENCE; METALLICITY AB We present complete Fermi-surface mappings of an untwinned single crystal of YBa2Cu3O7-delta in two distinct photon polarization geometries. Various methods for Fermi-surface determination with angle-resolved photoelectron spectroscopy are discussed and a technique based on the momentum space density of states is developed and applied. The data reveal the presence of two CuO2 plane-derived Fermi-surface pockets, along with weak evidence for a single chain sheet, in agreement with earlier work on twinned crystals and ab initio predictions, but show no sign of the expected "stick" pocket centered at (pi,pi). In contrast with earlier work on Bi2Sr2CaCu2O8+delta we see no evidence for "shadow bands" in optimally doped YBa2Cu3O7-delta supporting the contention that these features arise from structural rather than magnetic correlations. C1 Stanford Univ, Dept Appl Phys, Stanford, CA 94305 USA. Stanford Univ, Dept Phys, Stanford, CA 94305 USA. Stanford Univ, Stanford Synchrotron Radiat Lab, Stanford, CA 94305 USA. Univ British Columbia, Dept Phys & Astron, Vancouver, BC V6T 1Z1, Canada. RP Schabel, MC (reprint author), Stanford Univ, Dept Appl Phys, Stanford, CA 94305 USA. NR 30 TC 60 Z9 61 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 MAR 1 PY 1998 VL 57 IS 10 BP 6107 EP 6115 DI 10.1103/PhysRevB.57.6107 PG 9 WC Physics, Condensed Matter SC Physics GA ZB577 UT WOS:000072486500076 ER PT J AU Yan, Y Kirk, MA AF Yan, Y Kirk, MA TI Observation and mechanism of local oxygen reordering induced by high-energy heavy-ion (U+, Au+, Xe+) irradiation in the high-T-c superconductor YBa2Cu3O7-delta SO PHYSICAL REVIEW B LA English DT Article ID COLUMNAR DEFECTS; CRYSTALS; DAMAGE; FIELD AB Transmission electron microscopy study reveals that high-energy (>1 GeV) heavy-ion (U+, Au+, Xe+) irradiation in the c-axis direction of high-ir, superconductor YBa2Cu3O7-delta leads to the formation of aligned columnar defects, which are usually amorphous, and the associated volume expansion causes strain in surrounding matrix. Lobed "bow-tie" contrast is observed in both the [001] zone axis bright field and the high-resolution images of the regions surrounding the amorphous columns, the direction of which is rotated 90 degrees across a typical pre-existing twin boundary in YBa2Cu3O7-delta Our study shows that this contrast is caused by local oxygen reordering in the ab planes that gives a 90 degrees reorientation of the orthorhombic unit cell in the affected area. The mechanism of resulting oxygen reordering in the ab planes for this area is reported here. A qualitative result on the form, the position, and the size of the oxygen reordering region distributed around an isolated track and between two or more tracks, is related to the orientation of the Cu-O chain direction of matrix and the energy of incident ions. C1 Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. RP Yan, Y (reprint author), Argonne Natl Lab, Div Mat Sci, 9700 S Cass Ave, Argonne, IL 60439 USA. NR 20 TC 15 Z9 15 U1 1 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 MAR 1 PY 1998 VL 57 IS 10 BP 6152 EP 6164 DI 10.1103/PhysRevB.57.6152 PG 13 WC Physics, Condensed Matter SC Physics GA ZB577 UT WOS:000072486500082 ER PT J AU Yamada, K Lee, CH Kurahashi, K Wada, J Wakimoto, S Ueki, S Kimura, H Endoh, Y Hosoya, S Shirane, G Birgeneau, RJ Greven, M Kastner, MA Kim, YJ AF Yamada, K Lee, CH Kurahashi, K Wada, J Wakimoto, S Ueki, S Kimura, H Endoh, Y Hosoya, S Shirane, G Birgeneau, RJ Greven, M Kastner, MA Kim, YJ TI Doping dependence of the spatially modulated dynamical spin correlations and the superconducting-transition temperature in La2-xSrxCuO4 SO PHYSICAL REVIEW B LA English DT Article ID FERMI-SURFACE; MAGNETIC EXCITATIONS; ELECTRONIC-STRUCTURE; LA1.85SR0.15CUO4; DISAPPEARANCE; FLUCTUATIONS; LA2CUO4; GAP AB Systematic low-energy neutron-scattering studies have been performed on float-zone-grown single crystals of La2-xSrxCuO4 with x extending from zero doping, x = 0, to the overdoped, weakly superconducting regime, x = 0.25. For x beyond a critical doping value of x(c) approximate to 0.05 the low-energy spin-fluctuation peak position shifts from (1/2,1/2) to (1/2+/-delta,1/2), and (1/2,1/2+/-delta); x(c) also represents the onset concentration for superconductivity. For 0.06 less than or equal to x less than or equal to 0.12 the incommensurability delta follows approximately the quantitative relation delta=x. However, beyond x approximate to 0.12 the incommensurability tends to saturate around delta approximate to 1/8. The superconducting-transition temperature T-c(x) for stoichiometric samples at a given doping scales linearly with delta up to the optimal doping value of x. The peak momentum width of the spin fluctuations at low energies is small throughout the superconducting concentration region except in the strongly overdoped region. An anomalously small width is observed for x = 1/8. The incommensurate spatial modulation is found to be robust with respect to pair-breaking effects that lower T-c, such as deoxygenation of the sample or replacement of Cu by Zn. C1 Tohoku Univ, Dept Phys, Sendai, Miyagi 98077, Japan. Yamanashi Univ, Fac Engn, Inst Inorgan Synth, Kofu, Yamanashi 400, Japan. Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. MIT, Dept Phys, Cambridge, MA 02139 USA. RP Yamada, K (reprint author), Tohoku Univ, Dept Phys, Sendai, Miyagi 98077, Japan. RI Yamada, Kazuyoshi/C-2728-2009; Kim, Young-June /G-7196-2011 OI Kim, Young-June /0000-0002-1172-8895 NR 40 TC 739 Z9 740 U1 7 U2 59 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 MAR 1 PY 1998 VL 57 IS 10 BP 6165 EP 6172 DI 10.1103/PhysRevB.57.6165 PG 8 WC Physics, Condensed Matter SC Physics GA ZB577 UT WOS:000072486500083 ER PT J AU Bulaevskii, LN Maley, MP Vinokur, VM AF Bulaevskii, LN Maley, MP Vinokur, VM TI Vortex phases in irradiated highly anisotropic layered superconductors SO PHYSICAL REVIEW B LA English DT Article ID REVERSIBLE MAGNETIZATION; COLUMNAR DEFECTS; 2-DIMENSIONAL VORTICES; SINGLE-CRYSTALS; BI2SR2CACU2O8; TRANSITION AB Resistivity, reversible magnetization, and Josephson plasma resonance (JPR) data for Bi2Sr2CaCu2O8 With columnar defects (CD) show that two liquid phases exist above the irreversibility line. They differ by the c-axis correlations in pancake positions. We explain the existence of two liquids with different c-axis correlations and transition between them in some temperature interval exploring the particle-hole symmetry in the free energy functional for pancakes inside CD. This functional accounts for magnetic interaction of pancakes, their interaction via Josephson coupling, and pinning by CD. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. RP Bulaevskii, LN (reprint author), Univ Calif Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. NR 23 TC 7 Z9 7 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 MAR 1 PY 1998 VL 57 IS 10 BP R5626 EP R5629 DI 10.1103/PhysRevB.57.R5626 PG 4 WC Physics, Condensed Matter SC Physics GA ZB577 UT WOS:000072486500018 ER PT J AU Zuo, F Su, X Zhang, P Schlueter, JA Kelly, ME Williams, JM AF Zuo, F Su, X Zhang, P Schlueter, JA Kelly, ME Williams, JM TI Effects of inhomogeneity on the interlayer magnetoresistance in the organic superconductor kappa-(BEDT-TTF)(2)Cu[N(CN)(2)]Br SO PHYSICAL REVIEW B LA English DT Article ID MAGNETIC-FIELD; MIXED-STATE; SINGLE-CRYSTAL; KAPPA-(BEDT-TTF)2CUBR; BI2SR2CACU2O8 AB In this paper, we compare the interlayer transport in the organic superconductor kappa-(BEDT-TTF)(2)Cu[N(CN)(2)]Br on samples of different inhomogeneities in terms of resistive transition width Delta T. For field parallel to the current, H parallel to I, in the direction perpendicular to the layers, the isothermal magnetoresistance R(H) displays a peak effect as a function of field for high quality samples. The peak effect decreases gradually with increasing Delta T and it disappears completely for the sample with Delta T>2 K. The results demonstrate clearly that the peak in R(H) in the interlayer direction is intrinsic to the layered structure in this compound. C1 Univ Miami, Dept Phys, Coral Gables, FL 33124 USA. Argonne Natl Lab, Div Chem, Argonne, IL 60439 USA. Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. RP Zuo, F (reprint author), Univ Miami, Dept Phys, Coral Gables, FL 33124 USA. NR 17 TC 9 Z9 9 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 MAR 1 PY 1998 VL 57 IS 10 BP R5610 EP R5613 DI 10.1103/PhysRevB.57.R5610 PG 4 WC Physics, Condensed Matter SC Physics GA ZB577 UT WOS:000072486500014 ER PT J AU White, DH Hoff, RW Borner, HG Schreckenbach, K Hoyler, F Colvin, G Ahmad, I Friedman, AM Erskine, JR AF White, DH Hoff, RW Borner, HG Schreckenbach, K Hoyler, F Colvin, G Ahmad, I Friedman, AM Erskine, JR TI Nuclear structure of Pu-241 from neutron-capture, (d,p)-, and (d,t)-reaction measurements SO PHYSICAL REVIEW C LA English DT Article ID HIGH-FLUX REACTOR; GRENOBLE AB We report experimental measurements in Pu-241 of the following: primary and secondary gamma rays and conversion electrons from thermal neutron capture in Pu-240; gamma rays from Cm-245 alpha decay; proton and triton spectra, respectively, from (d,p) and (d,t) reactions on Pu-240 and Pu-242 targets. From these data and those of other investigations, we have identified 53 excited levels in Pu-241 below 1400 keV. Of these, 44 are placed in 10 rotational bands (with connecting transitions) that have been assigned Nilsson configurations. For the bands below 1 MeV in Pu-241 that are largely of single-particle character, then is good correspondence with similar bands in U-239 and with the theoretical model of Gareev et al. For those bands in Pu-241 where there is mixing between single-particle and vibrational modes, we find some significant deviations from theoretical predictions. For example, the 5/2[622]circle times 0(-) state at 519 keV appears to mix less with other states than predicted, while a trio of K-pi 1/2(-) bands show unexpected mixing patterns. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. Inst Max Von Laue Paul Langevin, F-38042 Grenoble, France. Argonne Natl Lab, Argonne, IL 60439 USA. RP White, DH (reprint author), Western Oregon Univ, Monmouth, OR 97361 USA. NR 34 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 0556-2813 J9 PHYS REV C JI Phys. Rev. C PD MAR PY 1998 VL 57 IS 3 BP 1112 EP 1133 DI 10.1103/PhysRevC.57.1112 PG 22 WC Physics, Nuclear SC Physics GA ZC593 UT WOS:000072596600016 ER PT J AU Doring, J Schatz, H Aprahamian, A de Haan, RC Gorres, J Wiescher, M Walters, WB Rikovska, J Brown, LT Davids, CN Lister, CJ Seweryniak, D Foy, B AF Doring, J Schatz, H Aprahamian, A de Haan, RC Gorres, J Wiescher, M Walters, WB Rikovska, J Brown, LT Davids, CN Lister, CJ Seweryniak, D Foy, B TI New isomer in Y-80 SO PHYSICAL REVIEW C LA English DT Article ID SHAPE CHANGES; HIGH-SPIN; NUCLEI; ISOTOPES; MOMENTS; DEFORMATIONS; STRONTIUM; ZIRCONIUM; BANDS; SR-79 AB The beta(+)/EC decay of mass-separated A = 80 nuclei was studied by means of beta- and gamma-ray spectroscopy after the bombardment of a Mg-24 target with Ni-58 ions at 190 MeV. A new 1(-) isomer at 228.5(1) keV has been identified in Y-80 With a half-life of 4.7(3) s. This new isomer decays to the 4(-) ground state with an 81(2)% branch and by beta(+)/EC transitions to levels in Sr-80 With a 19(2)% branch. The half-life of the Y-80 ground-state decay has been remeasured to be 30.1(5) s. A level scheme for the low-lying stales in Y-80 is presented. Hartree-Fock-Bogolyubov calculations show a large prolate deformation for these states, and two-quasiparticle + rotor model calculation results suggest that the low-lying states can be reproduced by inclusion of an effective proton-neutron residual interaction. The dominating Nilsson configurations for the 4(-) ground state and the 1(-) isomeric state have been found to originate from the parallel and antiparallel coupling of the proton [422]5/2(+) and the neutron [301]3/2(-) orbitals. C1 Univ Notre Dame, Dept Phys, Notre Dame, IN 46556 USA. Univ Maryland, Dept Chem, College Pk, MD 20742 USA. Univ Oxford, Dept Phys, Oxford OX1 3PU, England. Argonne Natl Lab, Div Phys, Argonne, IL 60439 USA. Vanderbilt Univ, Dept Phys, Nashville, TN 37235 USA. Clark Univ, Worcester, MA 01610 USA. RP Doring, J (reprint author), Univ Notre Dame, Dept Phys, Notre Dame, IN 46556 USA. NR 41 TC 16 Z9 16 U1 1 U2 1 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2813 J9 PHYS REV C JI Phys. Rev. C PD MAR PY 1998 VL 57 IS 3 BP 1159 EP 1166 DI 10.1103/PhysRevC.57.1159 PG 8 WC Physics, Nuclear SC Physics GA ZC593 UT WOS:000072596600020 ER PT J AU Ginocchio, JN Madland, DG AF Ginocchio, JN Madland, DG TI Pseudospin symmetry and relativistic single-nucleon wave functions SO PHYSICAL REVIEW C LA English DT Article ID MODEL AB We show that the occurrence of approximate pseudospin symmetry in nuclei is connected with certain similarities in the relativistic single-nucleon wave functions of the corresponding pseudospin doublets. We perform a case study in which several examples and the systematics of this connection are explored. C1 Univ Calif Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. RP Ginocchio, JN (reprint author), Univ Calif Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. NR 16 TC 112 Z9 113 U1 0 U2 1 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2813 J9 PHYS REV C JI Phys. Rev. C PD MAR PY 1998 VL 57 IS 3 BP 1167 EP 1173 DI 10.1103/PhysRevC.57.1167 PG 7 WC Physics, Nuclear SC Physics GA ZC593 UT WOS:000072596600021 ER PT J AU Bertsch, GF Hencken, K Esbensen, H AF Bertsch, GF Hencken, K Esbensen, H TI Nuclear breakup of Borromean nuclei SO PHYSICAL REVIEW C LA English DT Article ID INTERACTION CROSS-SECTIONS; MOMENTUM DISTRIBUTIONS; LI-11; FRAGMENTATION; DISSOCIATION; SCATTERING; RADII AB We study the eikonal model for the nuclear-induced breakup of Borromean nuclei, using Li-11 and He-6 as examples. The full eikonal model is difficult to realize because of six-dimensional integrals, but a number of simplifying approximations an found to be accurate. The integrated diffractive and one-nucleon stripping cross sections are rather insensitive to the neutron-neutron correlation, but the two-nucleon stripping does show some dependence on the correlation. The distribution of excitation energy in the neutron-core final state in one-neutron stripping reactions is quite sensitive to the shell structure of the halo wave function. Experimental data favor models with comparable amounts of s and p waves in the Li-11 halo. C1 Univ Washington, Inst Nucl Theory, Seattle, WA 98195 USA. Argonne Natl Lab, Div Phys, Argonne, IL 60439 USA. RP Bertsch, GF (reprint author), Univ Washington, Inst Nucl Theory, Seattle, WA 98195 USA. NR 37 TC 101 Z9 102 U1 0 U2 1 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2813 J9 PHYS REV C JI Phys. Rev. C PD MAR PY 1998 VL 57 IS 3 BP 1366 EP 1377 DI 10.1103/PhysRevC.57.1366 PG 12 WC Physics, Nuclear SC Physics GA ZC593 UT WOS:000072596600043 ER PT J AU Weppner, SP Elster, C Huber, D AF Weppner, SP Elster, C Huber, D TI Off-shell structures of nucleon-nucleon t matrices and their influence on nucleon-nucleus elastic scattering observables SO PHYSICAL REVIEW C LA English DT Article ID PROTON-SCATTERING; INTERMEDIATE ENERGIES; POTENTIAL MODELS; EXPANSION AB The sensitivity of nucleon-nucleus elastic scattering observables to the off-shell structure of nucleon-nucleon t matrices, derived from realistic NN potentials, is investigated within the context of a full-folding model based on the impulse approximation. Our study uses recently developed NN potential models which describe a subset of the NN data base with a chi(2) per datum similar to 1, which means that the NN t matrices are essentially on-shell equivalent. We calculate proton-nucleus elastic scattering observables for O-16, Ca-40, and Pb-208 between 100 and 200 MeV laboratory energy. We find that the elastic scattering observables are insensitive to off-shell differences of the employed NN t matrices. A more detailed investigation of the scattering equation and the optical potential as given in a factorized approximation reveals that the elastic scattering observables do not sample the NN t matrices very far off-shell where they exhibit differences. C1 Eckerd Coll, St Petersburg, FL 33711 USA. Ohio Univ, Inst Nucl & Particle Phys, Athens, OH 45701 USA. Ohio Univ, Dept Phys & Astron, Athens, OH 45701 USA. Univ Calif Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. RP Weppner, SP (reprint author), Eckerd Coll, St Petersburg, FL 33711 USA. RI Elster, Charlotte/N-9845-2015 NR 28 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 0556-2813 J9 PHYS REV C JI Phys. Rev. C PD MAR PY 1998 VL 57 IS 3 BP 1378 EP 1385 DI 10.1103/PhysRevC.57.1378 PG 8 WC Physics, Nuclear SC Physics GA ZC593 UT WOS:000072596600044 ER PT J AU Ahle, L Akiba, Y Ashktorab, K Baker, MD Beavis, D Britt, HC Chang, J Chasman, C Chen, Z Chi, CY Chu, YY Cianciolo, V Cole, BA Crawford, HJ Cumming, JB Debbe, R Eldredge, W Engelage, J Fung, SY Gaardhoje, JJ Gonin, M Gushue, S Hamagaki, H Hansen, AG Hansen, L Heintzelman, G Homma, S Hayano, RS Judd, E Kang, JH Kaneko, H Kumagai, A Kurita, K Levine, M Luke, J Miake, Y Moskowitz, B Moulson, M Nagamiya, S Namboodiri, MN Nayak, TK Ogilvie, CA Olness, J Remsberg, LP Sangster, TC Seto, R Shigaki, K Sako, H Soltz, R Steadman, SG Stephans, GSF Sung, T Tannenbaum, MJ Thomas, JH Tonse, SR Ueno-Hayashi, S Videbaek, F Wang, FQ Wang, Y Woodruff, DS Wu, Y Xu, G Yagi, K Zachary, D Zajc, WA Zhu, F Zhu, Q AF Ahle, L Akiba, Y Ashktorab, K Baker, MD Beavis, D Britt, HC Chang, J Chasman, C Chen, Z Chi, CY Chu, YY Cianciolo, V Cole, BA Crawford, HJ Cumming, JB Debbe, R Eldredge, W Engelage, J Fung, SY Gaardhoje, JJ Gonin, M Gushue, S Hamagaki, H Hansen, AG Hansen, L Heintzelman, G Homma, S Hayano, RS Judd, E Kang, JH Kaneko, H Kumagai, A Kurita, K Levine, M Luke, J Miake, Y Moskowitz, B Moulson, M Nagamiya, S Namboodiri, MN Nayak, TK Ogilvie, CA Olness, J Remsberg, LP Sangster, TC Seto, R Shigaki, K Sako, H Soltz, R Steadman, SG Stephans, GSF Sung, T Tannenbaum, MJ Thomas, JH Tonse, SR Ueno-Hayashi, S Videbaek, F Wang, FQ Wang, Y Woodruff, DS Wu, Y Xu, G Yagi, K Zachary, D Zajc, WA Zhu, F Zhu, Q TI Proton, deuteron, and triton emission at target rapidity in Au+Au collisions at 10.20A GeV: Spectra and directed flow SO PHYSICAL REVIEW C LA English DT Article ID HEAVY-ION COLLISIONS; HADRONIC MATTER; COLLECTIVE FLOW; ENERGY; SPECTROMETER; FRAGMENTS; DYNAMICS; DETECTOR; CASCADE AB Systematic results are presented on proton, deuteron, and triton emission from the target spectator region in collisions of 10.20A GeV gold projectiles with a gold target. A forward hodoscope utilizes detection of projectile spectator fragments to determine the orientation of the reaction plane, event by event. The directed flow (p(x)) is determined as a function of pseudorapidity. Projectile spectator energy is used to estimate impact parameters. Results are compared to current theoretical models ARC, ART, and RQMD. In all cases good agreement with theory is obtained for calculations utilizing a pure cascade without nuclear potential contributions. C1 Univ Tokyo, Inst Nucl Study, Tokyo 188, Japan. Brookhaven Natl Lab, Upton, NY 11973 USA. Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA. Univ Calif Riverside, Riverside, CA 92507 USA. Columbia Univ, New York, NY 10027 USA. Nevis Labs, Irvington, NY 10533 USA. Kyoto Univ, Sakyo Ku, Kyoto 606, Japan. Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. MIT, Cambridge, MA 02139 USA. Univ Tokyo, Dept Phys, Tokyo 113, Japan. Univ Tsukuba, Ibaraki, Osaka 305, Japan. Yonsei Univ, Seoul 120749, South Korea. Niels Bohr Inst, DK-2100 Copenhagen, Denmark. RP Ahle, L (reprint author), Univ Tokyo, Inst Nucl Study, Tokyo 188, Japan. RI seto, richard/G-8467-2011; Cumming, James/I-3358-2013; Hayano, Ryugo/F-7889-2012; HAMAGAKI, HIDEKI/G-4899-2014; OI Cumming, James/0000-0001-6930-0958; Hayano, Ryugo/0000-0002-1214-7806; Tannenbaum, Michael/0000-0002-8840-5314; Thomas, James/0000-0002-6256-4536; Ogilvie, Craig/0000-0002-5188-5123; Gaardhoje, Jens-Jorgen/0000-0001-6122-4698 NR 37 TC 18 Z9 18 U1 0 U2 2 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2813 J9 PHYS REV C JI Phys. Rev. C PD MAR PY 1998 VL 57 IS 3 BP 1416 EP 1427 DI 10.1103/PhysRevC.57.1416 PG 12 WC Physics, Nuclear SC Physics GA ZC593 UT WOS:000072596600049 ER PT J AU Batchelder, JC Bingham, CR Rykaczewski, K Toth, KS Davinson, T McKenzie, JA Woods, PJ Ginter, TN Gross, CJ McConnell, JW Zganjar, EF Hamilton, JH Walters, WB Baktash, C Greene, J Mas, JF Milner, WT Paul, SD Shapira, D Xu, XJ Yu, CH AF Batchelder, JC Bingham, CR Rykaczewski, K Toth, KS Davinson, T McKenzie, JA Woods, PJ Ginter, TN Gross, CJ McConnell, JW Zganjar, EF Hamilton, JH Walters, WB Baktash, C Greene, J Mas, JF Milner, WT Paul, SD Shapira, D Xu, XJ Yu, CH TI Observation of the exotic nucleus Tm-145 via its direct proton decay SO PHYSICAL REVIEW C LA English DT Article ID RADIOACTIVITY; EMITTERS AB Proton emission from Tm-145 was observed for the first time via the Mo-92(Ni-58,p4n) reaction, using the Holifield Radioactive Ion Beam Facility Recoil Mass Spectrometer in conjunction with a double-sided Si strip detector at the focal plane. The measured energy of the emitted proton is 1.728(10) MeV and its half-life is 3.5(10) mu s, the shortest ever observed for ground-state proton radioactivity. When compared to the calculated WKB half-life for an l=5 transfer, the spectroscopic factor is 0.51(16), which is consistent with the value of 0.64 calculated via the BCS approximation for a spherical nucleus. Also, the half-life of Cs-113 was determined with a greater precision than previously available to be 16.7(7) mu sec. C1 Oak Ridge Associated Univ, UNIRIB, Oak Ridge, TN 37831 USA. Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. Univ Tennessee, Knoxville, TN 37996 USA. Warsaw Univ, PL-00681 Warsaw, Poland. Univ Edinburgh, Edinburgh EH9 3JZ, Midlothian, Scotland. Vanderbilt Univ, Nashville, TN 37235 USA. Oak Ridge Inst Sci & Educ, Oak Ridge, TN 37831 USA. Louisiana State Univ, Baton Rouge, LA 70803 USA. Univ Maryland, College Pk, MD 20742 USA. Argonne Natl Lab, Argonne, IL 60439 USA. Inst Modern Phys, Lanzhou 730000, Peoples R China. Joint Inst Heavy Ion Res, Oak Ridge, TN 37831 USA. RP Batchelder, JC (reprint author), Oak Ridge Associated Univ, UNIRIB, Oak Ridge, TN 37831 USA. NR 23 TC 63 Z9 63 U1 0 U2 6 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2813 J9 PHYS REV C JI Phys. Rev. C PD MAR PY 1998 VL 57 IS 3 BP R1042 EP R1046 DI 10.1103/PhysRevC.57.R1042 PG 5 WC Physics, Nuclear SC Physics GA ZC593 UT WOS:000072596600006 ER PT J AU Busse, BC Fallon, P Krucken, R Ackermann, D Ahmad, I Asztalos, SJ Blumenthal, DJ Carpenter, MP Clark, RM Deleplanque, MA Diamond, RM Fischer, SM Hannachi, F Janssens, RVF Khoo, TL Korichi, A Lauritsen, T Lee, IY Lopez-Martens, A Macchiavelli, AO MacLeod, RW Moore, EF Nisius, D Schmid, G Seweryniak, D Stephens, FS Vetter, K AF Busse, BC Fallon, P Krucken, R Ackermann, D Ahmad, I Asztalos, SJ Blumenthal, DJ Carpenter, MP Clark, RM Deleplanque, MA Diamond, RM Fischer, SM Hannachi, F Janssens, RVF Khoo, TL Korichi, A Lauritsen, T Lee, IY Lopez-Martens, A Macchiavelli, AO MacLeod, RW Moore, EF Nisius, D Schmid, G Seweryniak, D Stephens, FS Vetter, K TI Lifetime measurements of yrast and excited superdeformed bands in Hg-192,Hg-193 SO PHYSICAL REVIEW C LA English DT Article ID STATES; HG-192; NUCLEI; SPIN AB Quadrupole moments of the six known superdeformed (SD) bands of Hg-193 and the yrast SD band of Hg-192 have been determined by a Doppler-shift-attenuation-method measurement utilizing the gammasphere array. The quadrupole moments of all Hg-193 SD bands were found to be similar, suggesting the active single-particle orbitals in the mass-190 region exhibit only small shape-driving effects. Additionally, there is evidence for an unexpected difference in the quadrupole moments of SD bands in Hg-192 and Hg-193. C1 Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. Argonne Natl Lab, Argonne, IL 60439 USA. N Carolina State Univ, Raleigh, NC 27695 USA. Triangle Univ Nucl Lab, Durham, NC 27708 USA. CNRS IN2P3, Ctr Spectrometrie Nucl & Spectrometrie Masse, F-91405 Orsay, France. CNRS IN2P3, Inst Phys Nucl, F-91406 Orsay, France. RP Busse, BC (reprint author), Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. RI Carpenter, Michael/E-4287-2015; Kruecken, Reiner/A-1640-2013 OI Carpenter, Michael/0000-0002-3237-5734; Kruecken, Reiner/0000-0002-2755-8042 NR 32 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 0556-2813 J9 PHYS REV C JI Phys. Rev. C PD MAR PY 1998 VL 57 IS 3 BP R1017 EP R1021 DI 10.1103/PhysRevC.57.R1017 PG 5 WC Physics, Nuclear SC Physics GA ZC593 UT WOS:000072596600001 ER PT J AU Hackman, G Janssens, RVF Khoo, TL Ahmad, I Greene, JP Amro, H Ackermann, D Carpenter, MP Fischer, SM Lauritsen, T Morss, LR Reiter, P Seweryniak, D Cline, D Wu, CY Moore, EF Nakatsukasa, T AF Hackman, G Janssens, RVF Khoo, TL Ahmad, I Greene, JP Amro, H Ackermann, D Carpenter, MP Fischer, SM Lauritsen, T Morss, LR Reiter, P Seweryniak, D Cline, D Wu, CY Moore, EF Nakatsukasa, T TI High-spin properties of octupole bands in Pu-240 and Cm-248 SO PHYSICAL REVIEW C LA English DT Article ID EXCITATIONS; HG-190; STATES AB High-spin states in Pu-240(94) and Cm-248(96) have been populated with Coulomb excitation at beam energies slightly above the Coulomb barrier. In each nucleus a new side band has been identified in gamma-gamma coincidence measurements and has been interpreted as the lowest-lying octupole excitation. The alignments and Routhians of these bands, as well as the branching ratios of El decays to the ground-state bands, are in good agreement with results from cranked RPA calculations. C1 Argonne Natl Lab, Argonne, IL 60439 USA. N Carolina State Univ, Raleigh, NC 27695 USA. Triangle Univ Nucl Lab, Durham, NC 27708 USA. Univ Rochester, Nucl Struct Res Lab, Rochester, NY 14627 USA. Univ Manchester, Inst Sci & Technol, Dept Phys, Manchester M60 1QD, Lancs, England. RP Hackman, G (reprint author), Argonne Natl Lab, Argonne, IL 60439 USA. RI Carpenter, Michael/E-4287-2015; Nakatsukasa, Takashi/O-9995-2014 OI Carpenter, Michael/0000-0002-3237-5734; NR 25 TC 21 Z9 21 U1 0 U2 2 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2813 J9 PHYS REV C JI Phys. Rev. C PD MAR PY 1998 VL 57 IS 3 BP R1056 EP R1059 DI 10.1103/PhysRevC.57.R1056 PG 4 WC Physics, Nuclear SC Physics GA ZC593 UT WOS:000072596600009 ER PT J AU Lane, GJ Fossan, DB Sears, JM Smith, JF Cameron, JA Clark, RM Hibbert, IM Janzen, VP Krucken, R Lee, IY Macchiavelli, AO Parry, CM Wadsworth, R AF Lane, GJ Fossan, DB Sears, JM Smith, JF Cameron, JA Clark, RM Hibbert, IM Janzen, VP Krucken, R Lee, IY Macchiavelli, AO Parry, CM Wadsworth, R TI Octupole correlations at low spin in Te-108(52)56 SO PHYSICAL REVIEW C LA English DT Article ID BAND TERMINATION; NUCLEI; SPECTROSCOPY; BEHAVIOR; ISOTOPES; ROTATION; SHAPES AB Excited states in Te-108 have been identified up to spins of similar to 20h using the extremely weak 2p2n evaporation channel (similar to 0.2% of sigma(fus)) from the bombardment of a backed Fe-54 target with 243 MeV Ni-58 ions. Channel selection and enhancement was made possible using the power of the GAMMASPHERE array to measure high-fold gamma-ray coincidences and the resultant application of multiple gamma-ray gating techniques. The observation in Te-108 of two interleaved sequences of levels with assumed opposite parity connected by enhanced El transitions is interpreted in terms of octupole correlations. The current results for Te-108 make it the closest nucleus to the predicted region of octupole deformation centered at N=Z=56 yet studied to high spin. C1 SUNY Stony Brook, Dept Phys & Astron, Stony Brook, NY 11794 USA. McMaster Univ, Dept Phys & Astron, Hamilton, ON L8S 4M1, Canada. Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. Univ York, Dept Phys, Heslington YO1 5DD, England. AECL Res, Chalk River Labs, Chalk River, ON K0J 1J0, Canada. RP Lane, GJ (reprint author), SUNY Stony Brook, Dept Phys & Astron, Stony Brook, NY 11794 USA. RI Lane, Gregory/A-7570-2011; Kruecken, Reiner/A-1640-2013 OI Lane, Gregory/0000-0003-2244-182X; Kruecken, Reiner/0000-0002-2755-8042 NR 26 TC 17 Z9 17 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2813 J9 PHYS REV C JI Phys. Rev. C PD MAR PY 1998 VL 57 IS 3 BP R1022 EP R1026 DI 10.1103/PhysRevC.57.R1022 PG 5 WC Physics, Nuclear SC Physics GA ZC593 UT WOS:000072596600002 ER PT J AU Lauret, J Albergo, S Bieser, F Ajitanand, NN Alexander, JM Brady, FP Caccia, Z Cebra, D Chacon, AD Chance, JL Choi, Y Chung, P Costa, S Danielewicz, P Elliott, JB Gilkes, M Hauger, JA Hirsch, AS Hjort, EL Insolia, A Justice, M Keane, D Kintner, J Lacey, RA Lindenstruth, V Lisa, MA Matis, HS McGrath, R McMahan, M McParland, C Muller, WFJ Olson, DL Partlan, MD Porile, NT Potenza, R Rai, G Rasmussen, J Ritter, HG Romanski, J Romero, JL Russo, GV Sann, H Scharenberg, R Scott, A Shao, Y Srivastava, BK Symons, TJM Tincknell, M Tuve, C Wang, S Warren, P Wienold, T Wieman, HH Wolf, K AF Lauret, J Albergo, S Bieser, F Ajitanand, NN Alexander, JM Brady, FP Caccia, Z Cebra, D Chacon, AD Chance, JL Choi, Y Chung, P Costa, S Danielewicz, P Elliott, JB Gilkes, M Hauger, JA Hirsch, AS Hjort, EL Insolia, A Justice, M Keane, D Kintner, J Lacey, RA Lindenstruth, V Lisa, MA Matis, HS McGrath, R McMahan, M McParland, C Muller, WFJ Olson, DL Partlan, MD Porile, NT Potenza, R Rai, G Rasmussen, J Ritter, HG Romanski, J Romero, JL Russo, GV Sann, H Scharenberg, R Scott, A Shao, Y Srivastava, BK Symons, TJM Tincknell, M Tuve, C Wang, S Warren, P Wienold, T Wieman, HH Wolf, K TI Dynamics of radial collective energy in near central collisions for 1A GeV Au+C SO PHYSICAL REVIEW C LA English DT Article ID HEAVY-ION COLLISIONS; STATISTICAL MULTIFRAGMENTATION; EMISSION; FLOW; EXPANSION; EQUATION; NUCLEI; STATE; GOLD AB Transverse kinetic energies of individual fragments have been measured over a broad range of emitter excitation energies for the reaction 1A GeV Au+C. For excitation energies leading to large intermediate mass fragment multiplicities, these transverse energies require large collective radial expansion of the emitting systems. However, the traditional decomposition of the transverse energy into a thermal component and a Coulomb and collective component proportional to the fragment mass cannot account for this expansion. Expansion velocities show an increase with decreasing fragment Z and thus indicate fractionation of the collective energy for the expanding system. This collective energy increases with emitter excitation up to about 50% of the energy deposited for a nuclear system with total energy similar to 12A MeV. The bulk of the collective energy is carried away by ejectiles of Z less than or equal to 3. C1 SUNY Stony Brook, Dept Chem, Stony Brook, NY 11794 USA. SUNY Stony Brook, Dept Phys, Stony Brook, NY 11794 USA. Purdue Univ, Dept Phys, W Lafayette, IN 47907 USA. Michigan State Univ, Nscl, E Lansing, MI 48824 USA. Michigan State Univ, Dept Phys, E Lansing, MI 48824 USA. Lawrence Berkeley Natl Lab, Div Nucl Sci, Berkeley, CA 94720 USA. Kent State Univ, Dept Phys, Kent, OH 44242 USA. Univ Calif Davis, Dept Phys, Davis, CA 95616 USA. Texas A&M Univ, Dept Phys, College Stn, TX 77843 USA. Ist Nazl Fis Nucl, Sez Catania, I-95129 Catania, Italy. Univ Catania, I-95129 Catania, Italy. Sung Kyun Univ, Chun Chun Dong 300, South Korea. GSI, D-64220 Darmstadt, Germany. RP Lauret, J (reprint author), SUNY Stony Brook, Dept Chem, Stony Brook, NY 11794 USA. RI Insolia, Antonio/M-3447-2015; TUVE', Cristina/P-3933-2015 OI Insolia, Antonio/0000-0002-9040-1566; TUVE', Cristina/0000-0003-0739-3153 NR 28 TC 21 Z9 21 U1 0 U2 1 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2813 J9 PHYS REV C JI Phys. Rev. C PD MAR PY 1998 VL 57 IS 3 BP R1051 EP R1055 DI 10.1103/PhysRevC.57.R1051 PG 5 WC Physics, Nuclear SC Physics GA ZC593 UT WOS:000072596600008 ER PT J AU Macchiavelli, AO Clark, RM Fallon, P Deleplanque, MA Diamond, RM Krucken, R Lee, IY Stephens, FS Asztalos, S Vetter, K AF Macchiavelli, AO Clark, RM Fallon, P Deleplanque, MA Diamond, RM Krucken, R Lee, IY Stephens, FS Asztalos, S Vetter, K TI Semiclassical description of the shears mechanism and the role of effective interactions SO PHYSICAL REVIEW C LA English DT Article ID BANDS; PB-200 AB By deriving the angle between the proton and neutron spin vectors <(j)over right arrow(pi)> and <(j)over right arrow(nu)> in the shears bands in Pb-198,Pb-199, we present a semiclassical analysis of the B(MI) and B(E2) transition probabilities as a function of the shears angle. This provides a semiempirical confirmation of the shears mechanism proposed by Frauendorf using the tilted-axis-cranking model. In addition, we propose that the rotational-like behavior observed for these bands may arise from a residual proton-neutron interaction. C1 Lawrence Berkeley Lab, Div Nucl Sci, Berkeley, CA 94720 USA. RP Macchiavelli, AO (reprint author), Lawrence Berkeley Lab, Div Nucl Sci, Berkeley, CA 94720 USA. RI Kruecken, Reiner/A-1640-2013 OI Kruecken, Reiner/0000-0002-2755-8042 NR 16 TC 48 Z9 50 U1 0 U2 1 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2813 J9 PHYS REV C JI Phys. Rev. C PD MAR PY 1998 VL 57 IS 3 BP R1073 EP R1076 DI 10.1103/PhysRevC.57.R1073 PG 4 WC Physics, Nuclear SC Physics GA ZC593 UT WOS:000072596600013 ER PT J AU Smith, JF Chiara, CJ Fossan, DB Lane, GJ Sears, JM Thorslund, I Amro, H Davids, CN Janssens, RVF Seweryniak, D Hibbert, IM Wadsworth, R Lee, IY Macchiavelli, AO AF Smith, JF Chiara, CJ Fossan, DB Lane, GJ Sears, JM Thorslund, I Amro, H Davids, CN Janssens, RVF Seweryniak, D Hibbert, IM Wadsworth, R Lee, IY Macchiavelli, AO TI First observation of excited states in Ba-118: Possible evidence for octupole correlations in neutron-deficient barium isotopes SO PHYSICAL REVIEW C LA English DT Article ID COINCIDENCE DATA SETS; HIGH-SPIN STATES; LIGHT XENON; NUCLEI; MASS; DEFORMATION; REGION; BANDS AB Excited states have been observed for the first time in the very neutron-deficient Ba-118 nuclide. The groundstate band and a side band have been observed up to spins 20 and 17 (h) over bar, respectively. The bands have been assigned to Ba-118 using gamma-recoil and gamma-x ray coincidences. Excitation-energy systematics suggest that the ground state of Ba-118 is less deformed than that of Ba-120. The side band decays into the ground-state band via three transitions, which are presumed to have El character. The occurrence of El transitions and negative-parity states in the very neutron-deficient barium (Z=56) isotopes is discussed with respect to the possible onset of octupole correlations. C1 SUNY Stony Brook, Dept Phys & Astron, Stony Brook, NY 11794 USA. Argonne Natl Lab, Argonne, IL 60439 USA. Univ York, Dept Phys, York YO1 5DD, N Yorkshire, England. Lawrence Berkeley Natl Lab, Div Nucl Sci, Berkeley, CA 94720 USA. RP Smith, JF (reprint author), SUNY Stony Brook, Dept Phys & Astron, Stony Brook, NY 11794 USA. EM jfsmith@nuclear.physics.sunysb.edu RI Lane, Gregory/A-7570-2011 OI Lane, Gregory/0000-0003-2244-182X NR 31 TC 15 Z9 15 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2813 J9 PHYS REV C JI Phys. Rev. C PD MAR PY 1998 VL 57 IS 3 BP R1037 EP R1041 DI 10.1103/PhysRevC.57.R1037 PG 5 WC Physics, Nuclear SC Physics GA ZC593 UT WOS:000072596600005 ER PT J AU Ellis, J Jack, I Jones, DRT Karliner, M Samuel, MA AF Ellis, J Jack, I Jones, DRT Karliner, M Samuel, MA TI Asymptotic Pade approximant predictions: Up to five loops in QCD and SQCD SO PHYSICAL REVIEW D LA English DT Article ID ESTIMATING PERTURBATIVE COEFFICIENTS; QUANTUM-FIELD THEORY; MANN LOW FUNCTION; BETA-FUNCTION; GAUGE-THEORIES; ELECTRODYNAMICS; EXPANSION AB We use asymptotic Pade approximants to predict the four-and five-loop beta functions in QCD and N=1 supersymmetric QCD, as well as the quark mass anomalous dimensions in Abelian and non-Abelian gauge theories. We show how the accuracy of our previous beta-function predictions at the four-loop level may be further improved by using estimators weighted over negative numbers of flavors (WAPAP's). The accuracy of the improved four-loop results encourages confidence in the new five-loop beta-function predictions that we present. However, the WAPAP approach does not provide improved results for the anomalous mass dimension, or for Abelian theories. C1 CERN, Div Theory, CH-1211 Geneva 23, Switzerland. Univ Liverpool, Dept Math Sci, Liverpool L69 3BX, Merseyside, England. Tel Aviv Univ, Sch Phys & Astron, Raymond & Beverly Sackler Fac Exact Sci, IL-69978 Tel Aviv, Israel. Oklahoma State Univ, Dept Phys, Stillwater, OK 74078 USA. Stanford Univ, SLAC, Stanford, CA 94309 USA. RP Ellis, J (reprint author), CERN, Div Theory, CH-1211 Geneva 23, Switzerland. NR 30 TC 53 Z9 53 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2821 J9 PHYS REV D JI Phys. Rev. D PD MAR 1 PY 1998 VL 57 IS 5 BP 2665 EP 2675 DI 10.1103/PhysRevD.57.2665 PG 11 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA YZ950 UT WOS:000072311500003 ER PT J AU Szczepaniak, A Ji, CR Radyushkin, A AF Szczepaniak, A Ji, CR Radyushkin, A TI Consistent analysis of O(alpha(s)) corrections to the pion elastic form factor SO PHYSICAL REVIEW D LA English DT Article ID INTERMEDIATE MOMENTUM-TRANSFER; EXCLUSIVE PROCESSES; PERTURBATIVE QCD; QUANTUM CHROMODYNAMICS; TRANSVERSE-MOMENTUM; ASYMPTOTIC-BEHAVIOR; SUM-RULES; APPLICABILITY; MESONS AB We examine the role of O(alpha(s)) perturbative corrections to the pion elastic form factor F-pi(Q(2)). We express the quark current three-point function in terms of light cone variables and use Borel transformation to simultaneously model the Feynman mechanism contribution determined by the soft part of the pion light cone wave function and the hard term involving one gluon exchange. We find that for Q(2) similar to 4 GeV2 the total O(alpha(s)) contribution may reach 30% of the soft contribution, even though its hard, factorization scale dependent part remains rather small. C1 N Carolina State Univ, Dept Phys, Raleigh, NC 27695 USA. Old Dominion Univ, Dept Phys, Norfolk, VA 23529 USA. Jefferson Lab, Newport News, VA 23606 USA. JINR, Theoret Phys Lab, Dubna, Russia. RP Szczepaniak, A (reprint author), Indiana Univ, Dept Phys, Bloomington, IN 47405 USA. RI Ji, Chueng/J-2623-2013 NR 25 TC 23 Z9 24 U1 0 U2 1 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2821 J9 PHYS REV D JI Phys. Rev. D PD MAR 1 PY 1998 VL 57 IS 5 BP 2813 EP 2822 DI 10.1103/PhysRevD.57.2813 PG 10 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA YZ950 UT WOS:000072311500016 ER PT J AU Baur, U Han, T Ohnemus, J AF Baur, U Han, T Ohnemus, J TI QCD corrections and anomalous couplings in Z gamma production at hadron colliders SO PHYSICAL REVIEW D LA English DT Article ID TOP-QUARK PRODUCTION; ALPHA-S CALCULATION; LEADING-LOGARITHM CALCULATION; WEAK-BOSON SECTOR; W+/-Z PRODUCTION; = 1.8 TEV; ROOT-S=1.8 TEV; P(P)OVER-BAR COLLISIONS; PHOTON PRODUCTION; CROSS-SECTION AB The processes pp((-))-->Z gamma+X-->l(+)l(-)gamma+X (l = e,mu) and pp((-))-->Z gamma y+X-->(v) over bar v gamma+X are calculated to O(alpha(s)) for general ZZ gamma and Z gamma gamma couplings. The impact of O(alpha(s)) QCD corrections on the observability of ZZ gamma and Z gamma gamma couplings in Z gamma production at the Fermilab Tevatron and the CERN Large Hadron Collider (LHC) is discussed. C1 SUNY Buffalo, Dept Phys, Buffalo, NY 14260 USA. Univ Calif Davis, Dept Phys, Davis, CA 95616 USA. Univ Wisconsin, Dept Phys, Madison, WI 53706 USA. Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Baur, U (reprint author), SUNY Buffalo, Dept Phys, Buffalo, NY 14260 USA. OI Han, Tao/0000-0002-5543-0716 NR 96 TC 91 Z9 91 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2821 J9 PHYS REV D JI Phys. Rev. D PD MAR 1 PY 1998 VL 57 IS 5 BP 2823 EP 2836 DI 10.1103/PhysRevD.57.2823 PG 14 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA YZ950 UT WOS:000072311500017 ER PT J AU Johnson, MB Kisslinger, LS AF Johnson, MB Kisslinger, LS TI Hadronic couplings via QCD sum rules using three-point functions: Vacuum susceptibilities SO PHYSICAL REVIEW D LA English DT Article ID PION FORM-FACTOR; NUCLEAR-MATTER; RESONANCE PHYSICS; MAGNETIC-MOMENTS; QUARK CONDENSATE; WAVE-FUNCTION; 2ND MOMENTS; CONSTANTS; BEHAVIOR; PROTON AB We develop a three-point formalism to treat vacuum susceptibilities used for the coupling of currents to hadrons within the method of QCD sum rules. By introducing nonlocal condensates, with the space-time structure taken from fits to experimental parton distrbutions, we show that one can treat hadronic: coupling at zero or low momentum transfer as well as medium and asymptotic momentum transfers and obtain a general expression for the;vacuum susceptibilities df the two-point formalism. The pion susceptibility, for which there has been a major uncertainty, is evaluated successfully with no new parameters. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Carnegie Mellon Univ, Dept Phys, Pittsburgh, PA 15213 USA. RP Johnson, MB (reprint author), Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. NR 35 TC 24 Z9 24 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2821 J9 PHYS REV D JI Phys. Rev. D PD MAR 1 PY 1998 VL 57 IS 5 BP 2847 EP 2852 DI 10.1103/PhysRevD.57.2847 PG 6 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA YZ950 UT WOS:000072311500019 ER PT J AU Burakovsky, L Goldman, T AF Burakovsky, L Goldman, T TI Regarding the enigmas of P-wave meson spectroscopy SO PHYSICAL REVIEW D LA English DT Article ID RELATIVIZED QUARK-MODEL; ANTIQUARK POTENTIAL MODELS; AXIAL-VECTOR MESONS; REGGE TRAJECTORIES; SCALAR MESONS; BOUND-STATES; CHARMONIUM; MASSES; DECAY; CHROMODYNAMICS AB The mass spectrum of P-wave mesons is considered in a nonrelativistic constituent quark model. The results show the common mass degeneracy of the isovector and isodoublet states of the scalar and tensor meson nonets, m(a(0))congruent to m(a(2)), m(K-0*)congruent to m(K-2*), and do not exclude the possibility of a similar degeneracy of the same states of the axial-vector and pseudovector nonets. Current experimental hadronic and tau-decay data suggest, however, a different scenario leading to the a(1) meson mass similar or equal to 1190 MeV and the K-1A-K-1B mixing angle = (37 +/- 3)degrees. Possible s (s) over bar states of the foul nonets are also discussed. C1 Univ Calif Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. RP Burakovsky, L (reprint author), Univ Calif Los Alamos Natl Lab, Div Theoret, MS B285, Los Alamos, NM 87545 USA. NR 59 TC 59 Z9 59 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2821 J9 PHYS REV D JI Phys. Rev. D PD MAR 1 PY 1998 VL 57 IS 5 BP 2879 EP 2888 DI 10.1103/PhysRevD.57.2879 PG 10 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA YZ950 UT WOS:000072311500023 ER PT J AU Bar-Shalom, S Eilam, G Soni, A Wudka, J AF Bar-Shalom, S Eilam, G Soni, A Wudka, J TI Implications of a W+W-(ZZ) Higgs boson t(c)over-bar interaction for e(+)e(-)-> t(c)over-bar-v(e)(v)over-bar(e), t(c)over-bar-e(+)e(-), t(c)over-bar-Z and for t -> cW(+)W(-), cZZ in a two Higgs doublet model SO PHYSICAL REVIEW D LA English DT Article ID CHANGING NEUTRAL CURRENTS; EFFECTIVE W-APPROXIMATION; HEAVY-LEPTON PRODUCTION; HIGH-ENERGY COLLISIONS; SCALAR INTERACTIONS; COLLIDERS; DECAYS; QUARKS; FUSION AB The standard model with one extra Higgs doublet may give rise to an enhanced tree-level flavor-changing-scalar coupling of a neutral Higgs boson to a pair of top-charm quarks. This coupling map drive a large tree-level effective W+W-(ZZ)-Higgs boson-t (c) over bar interaction. As a result we find that the reactions e(+)e(-) -->v(e) (v) over bar(e), t(c) over barZ$ and the two rare top decays t-->cW(+)W(-), t-->cZZ become very sensitive probes of such an effective interaction. The most promising ones, e(+)e(-) --> v(e) (v) over bar(e), e(+)e(-), may yield several hundreds and up to thousands of such events at the Next Linear Collider with a center of mass energy of root s= 0.5-2 TeV if the mass of the lightest neutral Higgs boson is a few hundred GeV. The rare decays t-->cW(+)W(-) and t-->cZZ may be accessible at the CERN LHC if the mass of the lightest neutral Higgs boson lies in the narrow window 150 GeV less than or similar to m(h) less than or similar to 200 GeV. C1 Univ Calif Riverside, Dept Phys, Riverside, CA 92521 USA. Technion Israel Inst Technol, Dept Phys, IL-32000 Haifa, Israel. Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. RP Bar-Shalom, S (reprint author), Univ Calif Riverside, Dept Phys, Riverside, CA 92521 USA. NR 36 TC 40 Z9 40 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2821 J9 PHYS REV D JI Phys. Rev. D PD MAR 1 PY 1998 VL 57 IS 5 BP 2957 EP 2968 DI 10.1103/PhysRevD.57.2957 PG 12 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA YZ950 UT WOS:000072311500029 ER PT J AU Kiers, K Weiss, N AF Kiers, K Weiss, N TI Neutrino oscillations in a model with a source and detector SO PHYSICAL REVIEW D LA English DT Article ID QUANTUM-MECHANICS; LAMBDA-OSCILLATIONS; DECAYS; MATTER; SPECTROSCOPY AB We study the oscillations of neutrinos in a model in which the neutrino is coupled to a localized, idealized source and detector. By varying the spatial and temporal resolution of the sourer and detector we are able to model the full range of source and detector types ranging from coherent to incoherent. We find that this approach is useful in understanding the interface between the quantum mechanical nature of neutrino oscillations on the one hand and the production and detection systems on the other hand. This method can easily be extended to study the oscillations of other particles such as the neutral K and B mesons. We find that this approach gives a reliable way to treat the various ambiguities which arise when one examines the oscillations from a wave packet point of view. We demonstrate that the conventional oscillation formula is correct in the relativistic limit and that several recent claims of an extra factor of 2 in the oscillation length are incorrect. We also demonstrate explicitly that the oscillations of neutrinos which have separated spatially may be "revived" by a long coherent measurement. C1 Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. Tel Aviv Univ, Sch Phys & Astron, IL-69978 Tel Aviv, Israel. Weizmann Inst Sci, Inst Particle Phys, IL-76100 Rehovot, Israel. Univ British Columbia, Dept Phys & Astron, Vancouver, BC V6T 1Z1, Canada. RP Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. EM kiers@bnl.gov; weissn@post.tau.ac.il NR 34 TC 30 Z9 30 U1 0 U2 2 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 2470-0010 EI 2470-0029 J9 PHYS REV D JI Phys. Rev. D PD MAR 1 PY 1998 VL 57 IS 5 BP 3091 EP 3105 DI 10.1103/PhysRevD.57.3091 PG 15 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA YZ950 UT WOS:000072311500043 ER PT J AU He, YD AF He, YD TI Can track-etch detector CR-39 record low-velocity GUT magnetic monopoles? SO PHYSICAL REVIEW D LA English DT Article ID SEARCH AB A set of new data on the response of the CR-39 detector to low-energy heavy ions, collected with a recently developed technique based on atomic force microscopy, was used to evaluate the effectiveness of nuclear stopping in producing etchable tracks relative to electronic stopping. The results for two types of CR-39 are found to be significantly different from those obtained previously with other methods. I discuss the implications of the use of CR-39 for detecting particles with low ionization rates such as supermassive magnetic monopoles in cosmic rays as cosmological relies. C1 Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Nucl Sci, Berkeley, CA 94720 USA. RP He, YD (reprint author), Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. NR 14 TC 6 Z9 6 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 MAR 1 PY 1998 VL 57 IS 5 BP 3182 EP 3185 DI 10.1103/PhysRevD.57.3182 PG 4 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA YZ950 UT WOS:000072311500054 ER PT J AU Scheidl, S Vinokur, VM AF Scheidl, S Vinokur, VM TI Driven dynamics of periodic elastic media in disorder SO PHYSICAL REVIEW E LA English DT Article ID CHARGE-DENSITY WAVES; THRESHOLD CRITICAL-DYNAMICS; FLUX-LINE-LATTICE; 4-EPSILON DIMENSIONS; II SUPERCONDUCTORS; VARIATIONAL THEORY; PHASE-TRANSITIONS; VORTEX LATTICES; DIRECTED LINES; FIELD-THEORY AB We analyze the large-scale dynamics of vortex lattices and charge-density waves driven in a disordered potential. Using a perturbative coarse-graining procedure, we present an explicit derivation of nonequilibrium terms in the renormalized equation of motion, in particular Kardar-Parisi-Zhang nonlinearities and dynamic strain terms. We demonstrate the absence of glassy features such as diverging linear friction coefficients and transverse critical currents in the drifting state. We discuss the structure of the dynamical phase diagram containing different elastic phases at very small and very large drives, and plastic phases at intermediate velocity. C1 Univ Cologne, Inst Theoret Phys, D-50937 Cologne, Germany. Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. RP Scheidl, S (reprint author), Univ Cologne, Inst Theoret Phys, Zulpicher Str 77, D-50937 Cologne, Germany. NR 75 TC 58 Z9 59 U1 1 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 MAR PY 1998 VL 57 IS 3 BP 2574 EP 2593 DI 10.1103/PhysRevE.57.2574 PN A PG 20 WC Physics, Fluids & Plasmas; Physics, Mathematical SC Physics GA ZD003 UT WOS:000072641100019 ER PT J AU Daw, CS Kennel, MB Finney, CEA Connolly, FT AF Daw, CS Kennel, MB Finney, CEA Connolly, FT TI Observing and modeling nonlinear dynamics in an internal combustion engine SO PHYSICAL REVIEW E LA English DT Article ID RECONSTRUCTION AB We propose a low-dimensional, physically motivated, nonlinear map as a model for cyclic combustion variation in spark-ignited internal combustion engines. A key feature is the interaction between stochastic, small-scale fluctuations in engine parameters and nonlinear deterministic coupling between successive engine cycles. Residual cylinder gas from each cycle alters the in-cylinder fuel-air ratio and thus the combustion efficiency in succeeding cycles. The model's simplicity allows rapid simulation of thousands of engine cycles, permitting statistical studies of cyclic-variation patterns and providing physical insight into this technologically important phenomenon. Using symbol statistics to characterize the noisy dynamics, we find good quantitative matches between our model and experimental time-series measurements. C1 Oak Ridge Natl Lab, Engn Technol Div, Oak Ridge, TN 37831 USA. Univ Calif San Diego, Inst Nonlinear Sci, La Jolla, CA 92093 USA. Univ Tennessee, Coll Engn, Knoxville, TN 37996 USA. Ford Motor Co, Dearborn, MI 48121 USA. RP Daw, CS (reprint author), Oak Ridge Natl Lab, Engn Technol Div, POB 2009, Oak Ridge, TN 37831 USA. NR 22 TC 112 Z9 116 U1 1 U2 11 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1063-651X J9 PHYS REV E JI Phys. Rev. E PD MAR PY 1998 VL 57 IS 3 BP 2811 EP 2819 DI 10.1103/PhysRevE.57.2811 PN A PG 9 WC Physics, Fluids & Plasmas; Physics, Mathematical SC Physics GA ZD003 UT WOS:000072641100047 ER PT J AU Dawson, SP Mineev-Weinstein, M AF Dawson, SP Mineev-Weinstein, M TI Dynamics of closed interfaces in two-dimensional Laplacian growth SO PHYSICAL REVIEW E LA English DT Article ID KURAMOTO-SIVASHINSKY EQUATION; HELE-SHAW FLOWS; PATTERN-FORMATION; INERTIAL MANIFOLDS; POLE DECOMPOSITION; CRYSTAL-GROWTH; FLAME FRONTS; MOTION AB We study the process of two-dimensional Laplacian growth in the limit of zero-surface tension for cases with a closed interface around a growing bubble (exterior problem with circular geometry). Using the time-dependent conformal map technique we obtain a class of fingerlike solutions that are characterized by a finite number of poles. We find the conditions under which these solutions remain smooth for all times. These solutions allow the description of the system in terms of a finite number of degrees of freedom, at least in the limit of zero-surface tension. We believe that, whenever they remain smooth, they can also be used as a nonlinear basis even when surface tension is included. C1 Univ Buenos Aires, Fac Ciencias Exactas & Nat, Dept Fis, RA-1428 Buenos Aires, DF, Argentina. Univ Calif Los Alamos Natl Lab, Div Theoret, Complex Syst Grp, Los Alamos, NM 87545 USA. RP Dawson, SP (reprint author), Univ Buenos Aires, Fac Ciencias Exactas & Nat, Dept Fis, Ciudad Univ,Pabellon 1, RA-1428 Buenos Aires, DF, Argentina. EM silvina@df.uba.ar; mariner@lanl.gov OI Ponce Dawson, Silvina/0000-0001-6550-4267 NR 39 TC 11 Z9 11 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 MAR PY 1998 VL 57 IS 3 BP 3063 EP 3072 PN B PG 10 WC Physics, Fluids & Plasmas; Physics, Mathematical SC Physics GA ZD006 UT WOS:000072641400001 ER PT J AU Towne, N Wang, JM AF Towne, N Wang, JM TI Spectrum of single bunch longitudinal dipole modes SO PHYSICAL REVIEW E LA English DT Article AB A mode of coherent longitudinal dipole motion of the beam in the National Synchrotron Light Source (NSLS) vacuum ultraviolet (vuv) ring with small frequency is observed by Biscardi et al. [Rev. Sci. Instrum. 66, 1856 (1995)]. We point out in this paper that the coherent motion observed is, although a solution to the well-known secular equation for Robinson instability, a distinct mode of beam dipole motion from what is normally known as the Robinson mode. In this paper the mode's properties and its relationships with the usual Robinson mode are developed. The collision of the two modes is understood analytically and observed experimentally in the NSLS vuv ring. C1 Brookhaven Natl Lab, Natl Synchrotron Light Source, Upton, NY 11973 USA. RP Towne, N (reprint author), Brookhaven Natl Lab, Natl Synchrotron Light Source, Upton, NY 11973 USA. NR 10 TC 3 Z9 3 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 MAR PY 1998 VL 57 IS 3 BP 3461 EP 3467 DI 10.1103/PhysRevE.57.3461 PN B PG 7 WC Physics, Fluids & Plasmas; Physics, Mathematical SC Physics GA ZD006 UT WOS:000072641400045 ER PT J AU Arunasalem, V AF Arunasalem, V TI Pauli nonrelativistic versus Dirac relativistic theory of the electron SO PHYSICS ESSAYS LA English DT Article DE Pauli Hamiltonian versus Dirac Hamiltonian; nonrelativistic versus relativistic theory of electron; relativity and g = 2; relativity and Schwinger (g - 2); nonrelativistic theoretical similarity between (g - 2); Lamb shift linearly and quadratically divergent nonrelativistic; self-energy integrals versus the corresponding logarithmically; divergent relativistic integrals electron electric dipole moment ID QUANTUM AB The formal, basic mathematical structure and the predictions of the Pauli (nonrelativistic) Galilean-invariant, the Dirac (relativistic) Lorentz-invariant, and the corresponding (relativistic) Lorentz-covariant (quantum) Hamiltonian theories of the spinning electron are compared and contrasted. It is pointed out that with the aid of the same simple correspondence principle these three theories are a direct and natural generalization of the corresponding nonrelativistic and relativistic (Klein-Gordon or) Schrodinger theories of spin-0 particles, and they all predict that the electron spin is 1/2 with a g-factor of about 2, and the same Schwinger value (g - 2) = 2e(2)/hc. That is, spin-1/2 and not only g = 2 but also the same Schwinger (g - 2) value for the electron also arise from the Pauli nonrelativistic theory and hence has nothing to do with the special theory of relativity. As pointed out by Weisskopf, in the relativistic theory the electron behaves as though it is spread over its Compton wavelength lambda = h/mc; thus the self-energy integrals are logarithmically divergent, while in the nonrelativistic theory the electron behaves as a point particle with linearly and quadratically divergent self-energy integrals which are fairly sensitive to the equivalent Bethe high-frequency cutoff at f(max) = mc(2)/h (i.e., omega(max) = mc(2)/h), since f(max) = c/(Compton wavelength lambda). C1 Princeton Univ, Princeton Plasma Phys Lab, Princeton, NJ 08543 USA. William Paterson State Coll, Dept Chem & Phys, Wayne, NJ 07470 USA. RP Arunasalem, V (reprint author), Princeton Univ, Princeton Plasma Phys Lab, POB 451, Princeton, NJ 08543 USA. NR 31 TC 1 Z9 1 U1 1 U2 1 PU PHYSICS ESSAYS PUBLICATION PI HULL PA C/O ALFT INC, 189 DEVEAULT ST, UNIT NO. 7, HULL, PQ J8Z1S7, CANADA SN 0836-1398 J9 PHYS ESSAYS JI Phys. Essays PD MAR PY 1998 VL 11 IS 1 BP 137 EP 143 PG 7 WC Physics, Multidisciplinary SC Physics GA ZQ369 UT WOS:000073854300013 ER PT J AU Kennedy, CA Chen, JH AF Kennedy, CA Chen, JH TI Mean flow effects on the linear stability of compressible planar jets SO PHYSICS OF FLUIDS LA English DT Article ID MIXING LAYER; INSTABILITY; NUMBER; NOISE AB An analytical solution is derived for the two-dimensional, laminar, compressible, planar free jet. The solution assumes constant pressure, specific heats, and unity Prandtl number and accounts for the effects of heat conduction and viscous dissipation in a self-consistent fashion. Exact closed-form expressions are provided for the streamwise and transverse velocities, temperature, vorticity, and dilatation. Temporal instability analyses of these high Reynolds number mean flows indicate that jet-to-ambient temperature ratio exerts a far greater effect on instability growth rates than compressibility. Relative to isothermal conditions, a hot jet flowing into cold ambient fluid is an order of magnitude more unstable and is unstable over a far greater range of wavenumbers. For this hot jet both symmetric and antisymmetric modes are equally amplified whereas isothermal jets have relatively stronger amplification of their antisymmetric modes. A cold jet issuing into a hot fluid is very stable relative to isothermal conditions. Increasing compressibility suppresses instability growth rates for all temperature ratios. All modes found were two-dimensional. Comparison of the instability analysis and the mean vorticity transport equation indicates that the relative instability growth rates of these jets is qualitatively predicted by the mean inertial vorticity generation term, -omega theta. Jets exhibiting the greatest mean vorticity generation rate inside of the jet half-thickness are the most unstable. C1 Sandia Natl Labs, Combust Res Facil, Livermore, CA 94551 USA. RP Kennedy, CA (reprint author), Sandia Natl Labs, Combust Res Facil, Livermore, CA 94551 USA. NR 67 TC 10 Z9 10 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 1070-6631 J9 PHYS FLUIDS JI Phys. Fluids PD MAR PY 1998 VL 10 IS 3 BP 615 EP 626 DI 10.1063/1.869599 PG 12 WC Mechanics; Physics, Fluids & Plasmas SC Mechanics; Physics GA YZ949 UT WOS:000072311400009 ER PT J AU Ernst, DR Bell, MG Bell, RE Bush, CE Chang, Z Fredrickson, E Grisham, LR Hill, KW Jassby, DL Mansfield, DK McCune, DC Park, HK Ramsey, AT Scott, SD Strachan, JD Synakowski, EJ Taylor, G Thompson, M Wieland, RM AF Ernst, DR Bell, MG Bell, RE Bush, CE Chang, Z Fredrickson, E Grisham, LR Hill, KW Jassby, DL Mansfield, DK McCune, DC Park, HK Ramsey, AT Scott, SD Strachan, JD Synakowski, EJ Taylor, G Thompson, M Wieland, RM TI Notched velocity profiles and the radial electric field in high ion temperature plasmas in the Tokamak Fusion Test Reactor SO PHYSICS OF PLASMAS LA English DT Article ID DIII-D TOKAMAK; NEOCLASSICAL TRANSPORT; TFTR TOKAMAK; H-MODE; POLOIDAL ROTATION; BOOTSTRAP CURRENT; HIGH CONFINEMENT; TURBULENCE; DEUTERIUM; MOMENTUM AB A large "notch," or non-monotonic feature, appears in measured toroidal velocity profiles of the carbon impurity in the Tokamak Fusion Test Reactor (TFTR) [Plasma Phys. Controlled Fusion 26, 11 (1984)], centered near the radius of strongest ion temperature gradient. This is explained as a consequence of radial momentum transport dominated by anomalous diffusion together with parallel heat friction on the impurity ions arising from the hydrogenic neoclassical parallel heat flow. The toroidal velocity profile of the hydrogenic species is predicted to be monotonic, from measurements of the impurity toroidal velocity, consistent with the anomalous radial diffusion of toroidal momentum. This supports a neoclassical calculation of the radial electric field for near-balanced beam injection. In supershot plasmas [Phys. Rev. Lett. 58, 1004 (1987)], a well structure in the radial electric field profile is found in the enhanced confinement region. An associated shear layer separates the core, where the local confinement trends are favorable, from the degraded outer region. This provides a mechanism for the nonlinear coupling of the ion temperature gradient, ion thermal confinement, and the radial electric field, which may help explain the favorable core confinement trends of very high temperature supershot plasmas. (C) 1998 American Institute of Physics. C1 MIT, Dept Phys, Cambridge, MA 02139 USA. Princeton Univ, Princeton Plasma Phys Lab, Princeton, NJ 08543 USA. RP Ernst, DR (reprint author), MIT, Dept Phys, 77 Massachusetts Ave, Cambridge, MA 02139 USA. EM dernst@pppl.gov RI Ernst, Darin/A-1487-2010 OI Ernst, Darin/0000-0002-9577-2809 NR 60 TC 55 Z9 55 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 MAR PY 1998 VL 5 IS 3 BP 665 EP 681 DI 10.1063/1.872771 PG 17 WC Physics, Fluids & Plasmas SC Physics GA ZA377 UT WOS:000072357400015 ER PT J AU Lee, DY Chance, MS Manickam, J Pomphrey, N Okabayashi, M AF Lee, DY Chance, MS Manickam, J Pomphrey, N Okabayashi, M TI Two-dimensional calculation of eddy currents on external conducting walls induced by low-n external modes SO PHYSICS OF PLASMAS LA English DT Article ID STABILIZATION; TOKAMAKS; SHELL AB The results of two-dimensional calculations of eddy currents induced on external conducting walls surrounding a tokamak are reported. The computed eddy currents are generated by low-n (n = 1,2,3) external ideal-magnetohydrodynamic (MHD) instabilities. For a given toroidal mode number n the eddy current patterns are found to be very similar in a variety of plasma configurations, e.g., different edge safety factors and different plasma-wall separation distances, in high beta plasmas. This result is promising for the design of active feedback coils for the stabilization of the resistive wall mode. Also, the effects of having a partial wall that has a poloidal gap on the outboard side are considered. Using the expected gap size in the proposed Korea Superconducting Tokamak Advanced Research (KSTAR) ["The KSTAR tokmak," in Proceedings of the 17th Symposium on Fusion Engineering, San Diego, 1997 (Institute of Electrical and Electronics Engineers, New York, in press), Paper No. O3.1], the calculation shows that active coils mounted behind the partial walls (the KSTAR passive plates) cover an adequate portion of the eddy current dominant region, enabling feedback stabilization. (C) 1998 American Institute of Physics. C1 Korea Adv Inst Sci & Technol, Ctr Plasma & Fus Studies, Taejon 305701, South Korea. Princeton Plasma Phys Lab, Princeton, NJ 08543 USA. RP Lee, DY (reprint author), Korea Adv Inst Sci & Technol, Ctr Plasma & Fus Studies, 373-1 Kusongdong, Taejon 305701, South Korea. EM dylee@yebbi.kaist.ac.kr RI pomphrey, neil/G-4405-2010 NR 11 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 1070-664X J9 PHYS PLASMAS JI Phys. Plasmas PD MAR PY 1998 VL 5 IS 3 BP 735 EP 742 DI 10.1063/1.872760 PG 8 WC Physics, Fluids & Plasmas SC Physics GA ZA377 UT WOS:000072357400021 ER PT J AU Chrien, RE Hoffman, NM Colvin, JD Keane, CJ Landen, OL Hammel, BA AF Chrien, RE Hoffman, NM Colvin, JD Keane, CJ Landen, OL Hammel, BA TI Fusion neutrons from the gas-pusher interface in deuterated-shell inertial confinement fusion implosions SO PHYSICS OF PLASMAS LA English DT Article ID NATIONAL-IGNITION-FACILITY; INDIRECTLY DRIVEN; HYDRODYNAMIC INSTABILITY; NOVA; GROWTH; SPECTROSCOPY; DESIGN; MIX AB The first measurements and numerical simulations of fusion neutrons from the gas-pusher interface of indirectly-driven inertial confinement fusion implosions have been performed using hydrogen-filled capsules made with a deuterated inner layer. Nonlinear saturation of the growth of hydrodynamic perturbations in high linear growth factor (similar or equal to 325) implosions was varied by adjusting the initial surface roughness of the capsule. The neutron yields are in quantitative agreement with the direct simulations of perturbation growth, and also with a linear mode superposition and saturation model including enhanced thermal loss in the mixed region. Neutron spectra from these capsules are broader than expected for the calculated ion temperatures, suggesting the presence of nonthermal broadening from mass motion during the fusion burn. (C) 1998 American Institute of Physics. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Chrien, RE (reprint author), Univ Calif Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. EM bchrien@lanl.gov NR 31 TC 18 Z9 18 U1 0 U2 3 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 1070-664X J9 PHYS PLASMAS JI Phys. Plasmas PD MAR PY 1998 VL 5 IS 3 BP 768 EP 774 DI 10.1063/1.872761 PG 7 WC Physics, Fluids & Plasmas SC Physics GA ZA377 UT WOS:000072357400025 ER PT J AU Rose, HA Ghosal, S AF Rose, HA Ghosal, S TI Effect of smoothing by spectral dispersion on flow induced laser beam deflection: The random phase modulation scheme SO PHYSICS OF PLASMAS LA English DT Article ID INERTIAL CONFINEMENT FUSION; UNIFORMITY; PLASMA AB Analytical results are presented for the effect of random phase modulated smoothing by spectral dispersion on flow induced laser beam deflection. It is shown that in the limit of a large number of color cycles, N-cc, the effect is identical to that of the induced spatial incoherence method of temporal smoothing. For small N-cc, the beam deflection rate may be significantly larger in the direction perpendicular to the dispersion, than in the parallel direction. (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 17 TC 7 Z9 7 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 MAR PY 1998 VL 5 IS 3 BP 775 EP 781 DI 10.1063/1.872763 PG 7 WC Physics, Fluids & Plasmas SC Physics GA ZA377 UT WOS:000072357400026 ER PT J AU Cohen, RH Ryutov, DD AF Cohen, RH Ryutov, DD TI Particle trajectories in a sheath in a strongly tilted magnetic field SO PHYSICS OF PLASMAS LA English DT Article ID HELMHOLTZ VORTEX FORMATION; PLASMA SHEATH; TRANSPORT; SURFACE AB In this paper we provide a systematic analysis of particle motion in a sheath under the condition that the magnetic field intersects the wall at a small angle. A general qualitative classification of particle trajectories is presented. It is shown that the ion motion in the ion subsheath can be described in terms of an adiabatic invariant, despite the fact that the electrostatic potential varies on a scale comparable with the ion gyroradius. Trajectories of heavy impurity ions for the cases of both low and high ionization states have been found. Electron motion is considered, and it is shown that, if the electron gyroradius is much less than the electron Debye radius, electrons hit the wall at shallow angles. The possible role of an electrostatic field directed along the wall is briefly discussed. The results obtained in the paper can be used for evaluating the sputtering rate and the secondary emission coefficient, as well as for analyzing sheath stability and for formulating the boundary conditions for the bulk of the plasma. (C) 1998 American Institute of Physics. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. RP Cohen, RH (reprint author), Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. NR 18 TC 18 Z9 18 U1 4 U2 9 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 MAR PY 1998 VL 5 IS 3 BP 808 EP 817 DI 10.1063/1.872764 PG 10 WC Physics, Fluids & Plasmas SC Physics GA ZA377 UT WOS:000072357400032 ER PT J AU Brandow, B AF Brandow, B TI Characteristic features of the exotic superconductors SO PHYSICS REPORTS-REVIEW SECTION OF PHYSICS LETTERS LA English DT Review DE superconductivity; exotic superconductors ID UPPER-CRITICAL-FIELD; HIGH-TEMPERATURE SUPERCONDUCTORS; MAGNETIC PENETRATION DEPTH; HIGH-TC-SUPERCONDUCTORS; PRESSURE ORGANIC SUPERCONDUCTOR; HEAVY-FERMION SUPERCONDUCTORS; ANGLE-RESOLVED PHOTOEMISSION; NORMAL STATE PROPERTIES; MUON-SPIN-RELAXATION; SINGLE-CRYSTAL K3C60 AB The exotic superconductors of this survey are those defined by Uemura and co-workers - the materials which approximately satisfy an empirical relation T-c proportional to lambda(L)(-2) where lambda(L) is the London penetration depth. As superconductors these materials are strange in many respects - in their chemistry and crystal structures, in many of their electronic and superconducting properties, and in their often conspicuously high transition temperatures. This category includes all of the presently known high-temperature superconductors. We now examine their unusual features in considerable detail, to sort out the features which are apparently universal (such as strong type-II behavior and high resistivity), or which are non-universal but common enough to be considered typical for this class (such as gap nodes). Several characteristics of the crystal chemistry are identified. Although fragments of this program have been reported often, this is the first attempt at a comprehensive examination. There appears to be a quasi-continuum of electronic behaviors, ranging from strongly exotic down to barely exotic cases. The location of a material within this continuum may thus depend on the relative strength of some "new" mechanism, as compared to the conventional phonon mechanism. In various places this survey is broadened to include other "strange formula" superconductors, since many other materials share the typical crystal-chemistry features of the exotic materials. (C) 1998 Elsevier Science B.V. C1 Los Alamos Natl Lab, Ctr Nonlinear Studies, Los Alamos, NM 87545 USA. RP Brandow, B (reprint author), Los Alamos Natl Lab, Ctr Nonlinear Studies, Los Alamos, NM 87545 USA. NR 714 TC 15 Z9 15 U1 0 U2 9 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0370-1573 EI 1873-6270 J9 PHYS REP JI Phys. Rep.-Rev. Sec. Phys. Lett. PD MAR PY 1998 VL 296 IS 1 BP 2 EP 63 PG 62 WC Physics, Multidisciplinary SC Physics GA YZ571 UT WOS:000072267400001 ER PT J AU Sessler, AM AF Sessler, AM TI Gamma-ray colliders and muon colliders SO PHYSICS TODAY LA English DT Article ID BEAMS C1 Ernest Orlando Lawrence Berkeley Natl Lab, Berkeley, CA USA. Amer Phys Soc, College Pk, MD 20740 USA. RP Sessler, AM (reprint author), Ernest Orlando Lawrence Berkeley Natl Lab, Berkeley, CA USA. NR 15 TC 7 Z9 7 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0031-9228 J9 PHYS TODAY JI Phys. Today PD MAR PY 1998 VL 51 IS 3 BP 48 EP 53 DI 10.1063/1.882185 PG 6 WC Physics, Multidisciplinary SC Physics GA ZA380 UT WOS:000072357700013 ER PT J AU Helmer, RG AF Helmer, RG TI Russell La Verne Heath - Obituary SO PHYSICS TODAY LA English DT Biographical-Item C1 Idaho Natl Engn & Environm Lab, Idaho Falls, ID USA. RP Helmer, RG (reprint author), Idaho Natl Engn & Environm Lab, Idaho Falls, ID USA. NR 0 TC 0 Z9 0 U1 0 U2 1 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0031-9228 J9 PHYS TODAY JI Phys. Today PD MAR PY 1998 VL 51 IS 3 BP 107 EP 108 DI 10.1063/1.882165 PG 2 WC Physics, Multidisciplinary SC Physics GA ZA380 UT WOS:000072357700020 ER PT J AU Soulen, RJ Fogle, WE AF Soulen, RJ Fogle, WE TI Author's expressions change in reaction to superfluidity glitches SO PHYSICS TODAY LA English DT Letter C1 USN, Res Lab, Washington, DC 20375 USA. Lawrence Berkeley Lab, Berkeley, CA USA. RP Soulen, RJ (reprint author), USN, Res Lab, Washington, DC 20375 USA. NR 2 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 0031-9228 J9 PHYS TODAY JI Phys. Today PD MAR PY 1998 VL 51 IS 3 BP 117 EP 117 DI 10.1063/1.882171 PG 1 WC Physics, Multidisciplinary SC Physics GA ZA380 UT WOS:000072357700028 ER PT J AU Anderson, LE Li, AD Stevens, FJ AF Anderson, LE Li, AD Stevens, FJ TI The enolases of ice plant and Arabidopsis contain a potential disulphide and are redox sensitive SO PHYTOCHEMISTRY LA English DT Article DE Arabidopsis thaliana; Brassicaceae; thale cress; Mesembryanthemum crystallinum; Aizoaceae; common ice plant; enolase; activity modulation; redox-sensitive cysteines ID CRYSTAL-STRUCTURE; YEAST ENOLASE; ACTIVE-SITE; 2.2-A RESOLUTION; EXPRESSION; PURIFICATION; COMPLEX; ACID; PHOSPHOENOLPYRUVATE; IDENTIFICATION AB The simulated structures of the enolases of Arabidopsis and the common ice plant contain a pair of Cys residues in the correct orientation to form a disulphide bond. Formation of this disulphide might be expected to affect the positioning of several residues in the active site. The enzyme in crude extracts of these two plants is activated by oxidation. Apparently formation of the disulphide crosslink enhances catalysis. The enolases from tomato leaves, maize roots and castor bean embryos lack one of these Cys residues and are not redox sensitive. It seems possible that enolase is redox-regulated by a cytosolic thioredoxin system in a limited number of plant species including ice plant and Arabidopsis. (C) 1998 Elsevier Science Ltd. All rights reserved. C1 Univ Illinois, Dept Sci Biol, Chicago, IL 60607 USA. Argonne Natl Lab, Ctr Mechanist Biol & Biotechnol, Argonne, IL 60439 USA. RP Anderson, LE (reprint author), Univ Illinois, Dept Sci Biol, 845 W Taylor St, Chicago, IL 60607 USA. NR 32 TC 18 Z9 18 U1 2 U2 2 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0031-9422 J9 PHYTOCHEMISTRY JI Phytochemistry PD MAR PY 1998 VL 47 IS 5 BP 707 EP 713 DI 10.1016/S0031-9422(97)00659-6 PG 7 WC Biochemistry & Molecular Biology; Plant Sciences SC Biochemistry & Molecular Biology; Plant Sciences GA ZE418 UT WOS:000072790600007 PM 9542166 ER PT J AU Young, KM AF Young, KM TI Workshop on Diagnostics for Fusion Plasmas - Varenna, Italy, 4-12 September 1997 SO PLASMA PHYSICS AND CONTROLLED FUSION LA English DT Editorial Material AB The Workshop on Diagnostics for Fusion Plasmas primarily concentrated on the diagnostic designs being prepared for ITER, but many of the challenges being addressed would be common with any ignited D-T fusion device. This short report gives some impression of the status of the diagnostics at this point in their design, towards the end of the EDA period. C1 Princeton Plasma Phys Lab, Princeton, NJ 08543 USA. RP Young, KM (reprint author), Princeton Plasma Phys Lab, POB 451, Princeton, NJ 08543 USA. NR 1 TC 0 Z9 0 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 MAR PY 1998 VL 40 IS 3 BP 445 EP 446 PG 2 WC Physics, Fluids & Plasmas SC Physics GA ZF521 UT WOS:000072905800009 ER PT J AU Koch, JA Landen, OL Hammel, BA Seely, J Barbee, TW Bennett, G Brown, C Celliers, P Da Silva, LB Glendinning, SG Hsing, W Kalantar, DH AF Koch, JA Landen, OL Hammel, BA Seely, J Barbee, TW Bennett, G Brown, C Celliers, P Da Silva, LB Glendinning, SG Hsing, W Kalantar, DH TI High-energy X-ray microscopy of laser-fusion plasmas at the National Ignition Facility SO PLASMA PHYSICS REPORTS LA English DT Article AB Multi-keV X-ray microscopy will be an important laser-produced plasma diagnostic at future megajoule facilities such as the National Ignition Facility (NIF). In preparation for the construction of this facility, we have investigated several instrumentation options in detail, and we conclude that near-normal-incidence single spherical or toroidal crystals may offer the best general solution for high-energy X-ray microscopy at NIF and at similar large facilities. Kirkpatrick-Baez microscopes using multilayer mirrors may also be good secondary options, particularly if apertures are used to increase the band width-limited field of view. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. USN, Res Lab, Washington, DC 20375 USA. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Koch, JA (reprint author), Univ Calif Lawrence Livermore Natl Lab, POB 808,L-473, Livermore, CA 94550 USA. NR 10 TC 0 Z9 0 U1 1 U2 3 PU MAIK NAUKA/INTERPERIODICA PUBL PI WOODBURY PA C/O AMERICAN INST PHYSICS, 500 SUNNYSIDE BLVD, MEMBER SUBSCRIBER SERVICES, WOODBURY, NY 11797-2999 USA SN 1063-780X J9 PLASMA PHYS REP JI Plasma Phys. Rep. PD MAR PY 1998 VL 24 IS 3 BP 177 EP 179 PG 3 WC Physics, Fluids & Plasmas SC Physics GA ZF061 UT WOS:000072858800002 ER PT J AU Cobble, JA Bessarab, AV Kunin, AV Tokarev, VA Goldman, SR AF Cobble, JA Bessarab, AV Kunin, AV Tokarev, VA Goldman, SR TI Radiation temperature measurements in laser-heated hohlraums SO PLASMA PHYSICS REPORTS LA English DT Article ID POWER AB Two X-ray spectrographs have been used on the Trident laser at LANL to monitor the radiation temperature of small Au hohlraums. The cylindrical targets are smaller than 1 mm, The X-radiation produced by similar to 400 J of 0.53 mu m laser light is detected with a 7-channel VNIIEF soft-X-ray spectrometer. Each channel employs a multilayer mirror and a filter to limit the channel bandwidth to 1-3% of the channel energy. X-rays are detected with calibrated A1 X-ray diodes, A second spectrometer is based on a freestanding Au transmission grating for spectral dispersion and a multichannel diamond photoconductive device detector. The small hohlraum results are consistent with radiation temperatures exceeding 100 eV. Simple computer modeling shows that, late in the plasma discharge, radiation of this temperature is emitted from the target. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Russian Fed Nucl Ctr, All Russia Sci Res Inst Expt Phys, Nizhnii Novgorod 607200, Russia. RP Cobble, JA (reprint author), Univ Calif Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. NR 9 TC 1 Z9 1 U1 0 U2 0 PU MAIK NAUKA/INTERPERIODICA PUBL PI WOODBURY PA C/O AMERICAN INST PHYSICS, 500 SUNNYSIDE BLVD, MEMBER SUBSCRIBER SERVICES, WOODBURY, NY 11797-2999 USA SN 1063-780X J9 PLASMA PHYS REP JI Plasma Phys. Rep. PD MAR PY 1998 VL 24 IS 3 BP 180 EP 182 PG 3 WC Physics, Fluids & Plasmas SC Physics GA ZF061 UT WOS:000072858800003 ER PT J AU Fthenakis, VM AF Fthenakis, VM TI Prevention and control of accidental releases of hazardous materials in PV facilities SO PROGRESS IN PHOTOVOLTAICS LA English DT Article; Proceedings Paper CT Workshop on the Environmental Aspects of PV Power Systems CY JUN, 1997 CL UNIV UTRECHT, UTRECHT, NETHERLANDS HO UNIV UTRECHT AB This paper reviews the approaches to preventing and mitigating accidental releases of toxic and flammable gases in photovoltaic R&D and manufacturing facilities. The prevention options are r elated to safer technologies, processes and materials, safer use of material, preventing accident-initiating events, preventing or minimizing releases and preventing human exposures. The mitigation options include secondary confinement, emergence scrubbers and adsorption units. (C) 1998 John Wiley & Sons, Ltd. C1 Brookhaven Natl Lab, Environm & Waste Technol Ctr, Dept Adv Technol, Upton, NY 11973 USA. RP Fthenakis, VM (reprint author), Brookhaven Natl Lab, Environm & Waste Technol Ctr, Dept Adv Technol, Upton, NY 11973 USA. NR 5 TC 4 Z9 4 U1 0 U2 0 PU JOHN WILEY & SONS LTD PI W SUSSEX PA BAFFINS LANE CHICHESTER, W SUSSEX PO19 1UD, ENGLAND SN 1062-7995 J9 PROG PHOTOVOLTAICS JI Prog. Photovoltaics PD MAR-APR PY 1998 VL 6 IS 2 BP 91 EP 98 DI 10.1002/(SICI)1099-159X(199803/04)6:2<91::AID-PIP213>3.0.CO;2-7 PG 8 WC Energy & Fuels; Materials Science, Multidisciplinary; Physics, Applied SC Energy & Fuels; Materials Science; Physics GA ZQ917 UT WOS:000073916000003 ER PT J AU Hart, PJ Liu, HB Pellegrini, M Nersissian, AM Gralla, EB Valentine, JS Eisenberg, D AF Hart, PJ Liu, HB Pellegrini, M Nersissian, AM Gralla, EB Valentine, JS Eisenberg, D TI Subunit asymmetry in the three-dimensional structure of a human CuZnSOD mutant found in familial amyotrophic lateral sclerosis SO PROTEIN SCIENCE LA English DT Article DE amyotrophic lateral sclerosis; apoptosis; Lou Gehrig's disease; motor neuron; neurodegeneration; oxidative damage; superoxide dismutase; X-ray crystallography ID CU/ZN-SUPEROXIDE-DISMUTASE; HYDROGEN-PEROXIDE; X-RAY; CU,ZN-SUPEROXIDE DISMUTASE; MOLECULAR-DYNAMICS; CRYSTAL-STRUCTURE; PULSE-RADIOLYSIS; TRANSGENIC MICE; MOTOR-NEURONS; ANIMAL-MODEL AB The X-ray crystal structure of a human copper/zinc superoxide dismutase mutant (G37R CuZnSOD) found in some patients with the inherited form of Lou Gehrig's disease (FALS) has been determined to 1.9 Angstrom resolution. The two SOD subunits have distinct environments in the crystal and are different in structure at their copper binding sites. One subunit (subunit(intact)) shows a four-coordinate ligand geometry of the copper ion, whereas the other subunit (subunit(broken)) shows a three-coordinate geometry of the copper ion. Also, subunit(intact) displays higher atomic displacement parameters for backbone atoms ([B] = 30 +/- 10 Angstrom(2)) than subunit(broken) ([B] = 24 +/- 11 Angstrom(2)). This structure is the first CuZnSOD to show large differences between the two subunits. Factors that may contribute to these differences are discussed and a possible link of a looser structure to FALS is suggested. C1 Univ Calif Los Angeles, US DOE, Lab Struct Biol & Mol Med, Los Angeles, CA 90095 USA. Univ Calif Los Angeles, Dept Chem & Biochem, Los Angeles, CA 90095 USA. Univ Calif Los Angeles, Dept Biol Chem, Los Angeles, CA 90095 USA. RP Eisenberg, D (reprint author), Univ Calif Los Angeles, Inst Mol Biol, Box 951570, Los Angeles, CA 90095 USA. EM david@pauling.mbi.ucla.edu RI Valentine, Joan/B-6665-2008 OI Valentine, Joan/0000-0002-7174-925X FU NIGMS NIH HHS [GM28222, GM31299] NR 75 TC 89 Z9 91 U1 1 U2 4 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 MAR PY 1998 VL 7 IS 3 BP 545 EP 555 PG 11 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA ZC005 UT WOS:000072530000002 PM 9541385 ER PT J AU Becker, M Stubbs, MT Huber, R AF Becker, M Stubbs, MT Huber, R TI Crystallization of phycoerythrin 545 of Rhodomonas lens using detergents and unusual additives SO PROTEIN SCIENCE LA English DT Article DE Cryptophyceae; detergent; light-harvesting protein; photosynthesis; phycobiliprotein; propionamide; protein crystal; X-ray diffraction ID CRYSTAL-STRUCTURE ANALYSIS; CRYPTOMONAD BILIPROTEINS; MASTIGOCLADUS-LAMINOSUS; ANGSTROM RESOLUTION; ENERGY-TRANSFER; C-PHYCOCYANIN; CHROOMONAS SP; MEMBRANE; REFINEMENT; PROTEINS AB Phycoerythrin 545 from the cryptomonad alga, Rhodomonas lens, has been crystallized under a wide variety of conditions. Although this type of photosynthetic light-harvesting protein is water soluble, detergents were always required for crystallization. The crystals were typically poorly ordered, or ordered in only two dimensions. However, crystals that were well-ordered in three dimensions could be obtained under two different conditions. Both used polyethylene glycol as precipitant and the detergent lauryldimethylaminoxide, but the additives that were critical for obtaining well-ordered crystals were propionamide in one case and Cs+/Br- in the other. Crystals obtained in the presence of propionamide have the space group P2(1)2(1)2(1), with cell constants of a = 85.6 Angstrom, b = 108.2 Angstrom, and c = 131.0 Angstrom, and contain two dimers [i.e., 2 X (alpha(2) beta(2))] in the asymmetric unit. They show diffraction to at least 3.0 Angstrom resolution. The crystals grown with Cs+/Br- are nearly isomorphous. Both types of crystals show intense, strongly polarized fluorescence, suggesting that energy transfer in the crystals is highly efficient. This should provide a basis for quantitative investigation of the role of exciton interactions in energy transfer in cryptomonad phycobiliproteins. C1 Max Planck Inst Biochem, Abt Strukturforsch, D-82152 Martinsried, Germany. RP Becker, M (reprint author), Brookhaven Natl Lab, Dept Biol, Bldg 463,POB 5000, Upton, NY 11973 USA. NR 30 TC 9 Z9 9 U1 0 U2 2 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 MAR PY 1998 VL 7 IS 3 BP 580 EP 586 PG 7 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA ZC005 UT WOS:000072530000006 PM 9541389 ER PT J AU Trakhanov, S Kreimer, DI Parkin, S Ames, GFL Rupp, B AF Trakhanov, S Kreimer, DI Parkin, S Ames, GFL Rupp, B TI Cadmium-induced crystallization of proteins: II. Crystallization of the Salmonella typhimurium histidine-binding protein in complex with L-histidine, L-arginine, or L-lysine SO PROTEIN SCIENCE LA English DT Article DE cadmium addition; crystal growth; crystallization; crystal morphology; histidine binding protein; X-ray crystallography ID PRELIMINARY-X-RAY; LIGAND AB To further investigate favorable effects of divalent cations on the formation of protein crystals, three complexes of Salmonella typhimurium histidine-binding protein were crystallized with varying concentrations of cadmium salts. For each of the three histidine-binding protein complexes, cadmium cations were found to promote or improve crystallization. The optimal cadmium concentration is ligand specific and falls within a narrow concentration range. In each case, crystals grown in the presence of cadmium diffract to better than 2.0 Angstrom resolution and belong to the orthorhombic space group P2(1)2(1)2(1). From our results and from the analysis of cadmium sites in well-refined protein structures, we propose that cadmium addition provides a generally useful technique to modify crystal morphology and to improve diffraction quality. C1 Univ Calif Lawrence Livermore Natl Lab, Biol & Biotechnol Res Program, Livermore, CA 94550 USA. Univ Calif Berkeley, Dept Mol & Cellular Biol, Div Biochem & Mol Biol, Berkeley, CA 94720 USA. RP Rupp, B (reprint author), Univ Calif Lawrence Livermore Natl Lab, Biol & Biotechnol Res Program, L-452, Livermore, CA 94550 USA. RI Parkin, Sean/E-7044-2011 FU NIDDK NIH HHS [DK 12121] NR 19 TC 31 Z9 31 U1 0 U2 4 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 MAR PY 1998 VL 7 IS 3 BP 600 EP 604 PG 5 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA ZC005 UT WOS:000072530000008 PM 9541391 ER PT J AU Harpel, MR Larimer, FW Hartman, FC AF Harpel, MR Larimer, FW Hartman, FC TI Multiple catalytic roles of His 287 of Rhodospirillum rubrum ribulose 1,5-bisphosphate carboxylase/oxygenase SO PROTEIN SCIENCE LA English DT Article DE analysis of partial reactions; reaction-intermediate stabilization; Rubisco; site-directed mutagenesis ID SITE-DIRECTED MUTANT; EPSILON-AMINO GROUP; RIBULOSE-1,5-BISPHOSPHATE CARBOXYLASE; RIBULOSEBISPHOSPHATE CARBOXYLASE; ACTIVE-SITE; CARBON-DIOXIDE; CRYSTAL-STRUCTURE; CO2/O2 SPECIFICITY; BETA-ELIMINATION; LYSYL RESIDUE AB Active-site His 287 of Rhodospirillum rubrum ribulose 1,5-bisphosphate (RuBP) carboxylase/oxygenase interacts with the C3-hydroxyl of bound substrate or reaction-intermediate analogue (CABP), water molecules, and ligands for the activator metal-ion (Andersson I, 1996, J Mol Biol 259:160-174; Taylor TC, Andersson I, 1997, J Mol Biol 265:432-444). To test structure-based postulates of catalytic functionality, His 287 was replaced with Asn or Gln. The mutants are not affected adversely in subunit assembly, activation (binding of Mg(2+) and carbamylation of Lys 191), or recognition of phosphorylated ligands; they bind CABP with even greater tenacity than does wild-type enzyme. H287N and H287Q are severely impaired in catalyzing overall carboxylation (similar to 10(3)-fold and >10(5)-fold, respectively) and enolization (each mutant below threshold for detection) of RuBP. H287N preferentially catalyzes decarboxylation of carboxylated reaction intermediate instead of forward processing to phosphoglycerate. Analysis of RuBP turnover that occurs at high concentrations of mutants over extended time periods reveal >10-fold reduced CO(2)/O(2) specificities, elevated misprotonation of the enediol intermediate, and misprocessing of the oxygenated intermediate of the oxygenase pathway. These results are consistent with multifaceted roles for His 287 in promoting enediol formation, enediol tautomerization, and forward-processing of carboxylated intermediate. C1 Oak Ridge Natl Lab, Div Life Sci, Prot Engn Program, Oak Ridge, TN 37831 USA. RP Hartman, FC (reprint author), Oak Ridge Natl Lab, Div Life Sci, Prot Engn Program, Oak Ridge, TN 37831 USA. EM hartmanfc@ornl.gov NR 52 TC 12 Z9 12 U1 0 U2 3 PU WILEY-BLACKWELL PI MALDEN PA COMMERCE PLACE, 350 MAIN ST, MALDEN 02148, MA USA SN 0961-8368 J9 PROTEIN SCI JI Protein Sci. PD MAR PY 1998 VL 7 IS 3 BP 730 EP 738 PG 9 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA ZC005 UT WOS:000072530000022 PM 9541405 ER PT J AU Kim, SH AF Kim, SH TI Structure-based inhibitor design for CDK2, a cell cycle controlling protein kinase SO PURE AND APPLIED CHEMISTRY LA English DT Article; Proceedings Paper CT AFMC International Medicinal Chemistry Symposium (AIMECS 97) CY JUL 27-AUG 01, 1997 CL SEOUL, SOUTH KOREA SP IUPAC, Asian Federat Med Chem ID DEPENDENT KINASES; COMPLEX; ACTIVATION AB The central role of cyclin-dependent kinases (CDKs) in cell cycle regulation makes them a promising target for discovering small inhibitory molecules that can modify the degree of cell proliferation. The three-dimensional structure of CDK2 provides a structural foundation for understanding the mechanisms of activation and inhibition of CDK2 and for the discovery of the inhibitors. In this presentation five structures of human CDK2 are summarized: apo protein, ATP complex, olomoucine complex, isopentenyladenine complex, and flavopiridol complex. This structural information is used for the design of a small, directed combinatorial library. C1 Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Kim, SH (reprint author), Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. NR 20 TC 21 Z9 21 U1 0 U2 3 PU BLACKWELL SCIENCE LTD PI OXFORD PA P O BOX 88, OSNEY MEAD, OXFORD OX2 0NE, OXON, ENGLAND SN 0033-4545 J9 PURE APPL CHEM JI Pure Appl. Chem. PD MAR PY 1998 VL 70 IS 3 BP 555 EP 565 DI 10.1351/pac199870030555 PG 11 WC Chemistry, Multidisciplinary SC Chemistry GA 100WP UT WOS:000074838600006 ER PT J AU Werst, DW Han, P Trifunac, AD AF Werst, DW Han, P Trifunac, AD TI Radiation chemical studies in zeolites: Radical cations and zeolite catalysis SO RADIATION PHYSICS AND CHEMISTRY LA English DT Review ID ELECTRON-TRANSFER REACTIONS; H-MORDENITE; RESONANCE; MATRICES; EPR; ADSORPTION; OLEFINS AB The constrained spaces within zeolites offer unique opportunities for chemical reaction control of very reactive intermediates. Here we review studies which illustrate the use of EPR detection of paramagnetic species following radiolysis of guest molecules in zeolites to gain new insights into reactions of organic radical cations. The radiolysis/EPR technique is also a valuable method to study catalytic transformations on acidic zeolites. In essence, radiolysis is used to spin label products of catalysis in order that they may be detected and identified by EPR. Several examples are presented to show that application at low temperatures makes the radiolysis/EPR method a promising new in situ spectroscopy for elucidating mechanisms in zeolite catalysis. (C) 1998 Elsevier Science Ltd. All rights reserved. C1 Argonne Natl Lab, Div Chem, Argonne, IL 60439 USA. RP Werst, DW (reprint author), Argonne Natl Lab, Div Chem, Argonne, IL 60439 USA. NR 32 TC 21 Z9 21 U1 1 U2 5 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND J9 RADIAT PHYS CHEM JI Radiat. Phys. Chem. PD MAR PY 1998 VL 51 IS 3 BP 255 EP 262 DI 10.1016/S0969-806X(97)00113-8 PG 8 WC Chemistry, Physical; Nuclear Science & Technology; Physics, Atomic, Molecular & Chemical SC Chemistry; Nuclear Science & Technology; Physics GA ZL951 UT WOS:000073489900004 ER PT J AU Liu, AD Shkrob, IA Sauer, MC Trifunac, AD AF Liu, AD Shkrob, IA Sauer, MC Trifunac, AD TI High mobility solvent holes in cycloalkane liquids studied by a two-color laser ionization SO RADIATION PHYSICS AND CHEMISTRY LA English DT Article ID CYCLOHEXANE; IONS; CATION AB Solvent holes were studied in two-laser, two-color experiments in decalin, methylcyclohexane, and cyclohexane solutions containing aromatic solutes. The holes were produced by photoinduced valence band electron transfer from the solvent to the excited doublet states of aromatic radical cations. The d.c. conductivity signals of these rapidly migrating holes exhibit an exponential decay in both decalins and methylcyclohexane. The rate constants for reaction of the solvent holes with various solutes were measured in trans-decalin, mixtures of trans-and cis-decalins, and methylcyclohexane at room temperature. (C) 1998 Elsevier Science Ltd. All rights reserved. C1 Argonne Natl Lab, Div Chem, Argonne, IL 60439 USA. RP Trifunac, AD (reprint author), Argonne Natl Lab, Div Chem, 9700 S Cass Ave, Argonne, IL 60439 USA. NR 18 TC 8 Z9 8 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND J9 RADIAT PHYS CHEM JI Radiat. Phys. Chem. PD MAR PY 1998 VL 51 IS 3 BP 273 EP 280 DI 10.1016/S0969-806X(97)00269-7 PG 8 WC Chemistry, Physical; Nuclear Science & Technology; Physics, Atomic, Molecular & Chemical SC Chemistry; Nuclear Science & Technology; Physics GA ZL951 UT WOS:000073489900007 ER PT J AU Smith, CL AF Smith, CL TI Calculating conditional core damage probabilities for nuclear power plant operations SO RELIABILITY ENGINEERING & SYSTEM SAFETY LA English DT Article AB A part of managing nuclear power plant operations is the control of plant risk over time as components are taken out of service or plant upsets are caused by initiating events. Unfortunately, measuring risk over time proves to be challenging, even with modern probabilistic risk analyses (PRAs) and PRA tools. In general, the process of measuring the operational risk would satisfy three desires: (I)the measurement would provide the risk magnitude for a particular event or over a period of time; (2) the risk results could be summed for a period of time to obtain a cumulative risk profile: and (3) the measurement process would be tractable while still using the current modeling techniques and tools. This paper demonstrates the calculation of the conditional core damage probability (CCDP) for the two cases of component outages and initiating events. In addition, two potential complications were identified that must be addressed when performing a CCDP calculation. The first complication, determining the appropriate nonrecovery probabilities to be applied to an inoperable component or initiating event, addresses the possibility of the plant operators preventing damage to the plant from their actions. The second complication, adjusting common-cause probabilities specific to the plant configuration, accounts for the fact that the PRA common-cause probabilities built into the model are applicable only during nominal conditions. The examples presented in the paper illustrate the potential underestimation in CCDP when modifications to common-cause probabilities are ignored. These underestimation errors ranged from a factor of two to over a factor of six underestimation in CCDP. (C) 1998 Elsevier Science Limited.. C1 Idaho Natl Engn & Environm Lab, Idaho Falls, ID 83415 USA. RP Smith, CL (reprint author), Idaho Natl Engn & Environm Lab, Idaho Falls, ID 83415 USA. NR 11 TC 16 Z9 16 U1 0 U2 0 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0951-8320 J9 RELIAB ENG SYST SAFE JI Reliab. Eng. Syst. Saf. PD MAR PY 1998 VL 59 IS 3 BP 299 EP 307 DI 10.1016/S0951-8320(97)00152-X PG 9 WC Engineering, Industrial; Operations Research & Management Science SC Engineering; Operations Research & Management Science GA ZJ646 UT WOS:000073237600005 ER PT J AU Yeung, J Brown, JT Nair, A Meites, E Coppel, RL Mohandas, N Meyer-Ilse, W Magowan, C AF Yeung, J Brown, JT Nair, A Meites, E Coppel, RL Mohandas, N Meyer-Ilse, W Magowan, C TI X-ray microscopic visualization of specific labeling of adhesive molecule CD36 and cytoadherence by Plasmodium falciparum infected erythrocytes. SO RESEARCH COMMUNICATIONS IN MOLECULAR PATHOLOGY AND PHARMACOLOGY LA English DT Article ID MEMBRANE GLYCOPROTEIN; ANTIGENIC VARIATION; BAND-3 PROTEIN; MALARIA; RECEPTOR; SEQUESTRATION; SURFACE; CELLS; GENE; LOCALIZATION AB We investigated the cytoadherence of Plasmodium falciparum infected erythrocytes to target cells that express CD36 by soft x-ray microscopy. Using immunogold beads enhanced with silver, we localized CD36 on the surface of intact melanoma cells and throughout Triton extracted melanoma cells. We examined the orientation of parasites within erythrocytes that bound to target cells, and the interactions between the red cell membrane and the target cell, and we confirmed that fibrillar structures on the surface of melanoma and endothelial cells can be involved in the association between infected erythrocytes and melanoma cells or endothelial cells. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Div Life Sci, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Ctr Xray Opt, Berkeley, CA 94720 USA. Monash Univ, Dept Microbiol, Clayton, Vic 3168, Australia. RP Magowan, C (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Div Life Sci, Berkeley, CA 94720 USA. RI Coppel, Ross/A-6626-2008; OI Coppel, Ross/0000-0002-4476-9124; Meites, Elissa/0000-0002-0077-2591 FU NIDDK NIH HHS [DK32094-10] NR 38 TC 3 Z9 3 U1 0 U2 0 PU P J D PUBLICATIONS LTD PI WESTBURY PA PO BOX 966, WESTBURY, NY 11590 USA SN 1078-0297 J9 RES COMMUN MOL PATH JI Res. Commun. Mol. Pathol. Pharmacol. PD MAR PY 1998 VL 99 IS 3 BP 245 EP 258 PG 14 WC Biochemistry & Molecular Biology; Pathology; Pharmacology & Pharmacy SC Biochemistry & Molecular Biology; Pathology; Pharmacology & Pharmacy GA ZJ713 UT WOS:000073245000001 PM 9591321 ER PT J AU Power, JG Conde, ME AF Power, JG Conde, ME TI A 3.9 MeV photoinjector and delay system for Wakefield measurements SO REVIEW OF SCIENTIFIC INSTRUMENTS LA English DT Article AB We report on the characterization of the 3.9 MeV electron beam from a rf photoinjector at the Argonne Wakefield Accelerator. This beam is used to diagnose wakefields produced by the 15 MeV beam from a second rf photoinjector. We measured the emittance with the usual quadrupole scan method but used a fitting algorithm that includes space-charge forces. This photocathode gun has produced a beam charge per pulse ranging from 10 pC to 4 nC, but is normally operated at 100 pC with a measured normalized emittance of 3.4 pi mm mrad and bunch length of 8 ps full width at half maximum. (C) 1998 American Institute of Physics. [S0034-6748(98)01203-9]. C1 Argonne Natl Lab, Argonne, IL 60439 USA. RP Power, JG (reprint author), Argonne Natl Lab, 9700 S Cass Ave, Argonne, IL 60439 USA. NR 13 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 0034-6748 J9 REV SCI INSTRUM JI Rev. Sci. Instrum. PD MAR PY 1998 VL 69 IS 3 BP 1295 EP 1297 DI 10.1063/1.1148793 PG 3 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA ZC403 UT WOS:000072574500017 ER PT J AU Liu, Y Alton, GD Mills, GD Reed, CA Haynes, DL AF Liu, Y Alton, GD Mills, GD Reed, CA Haynes, DL TI Design aspects of a compact, single-frequency, permanent-magnet electron cyclotron resonance ion source with a large uniformly distributed resonant plasma volume SO REVIEW OF SCIENTIFIC INSTRUMENTS LA English DT Article AB compact, all-permanent-magnet single-frequency electron cyclotron resonance (ECR) ion source with a large uniformly distributed ECR plasma volume has been designed and is presently under construction at the Oak Ridge National Laboratory. The central region of the field is designed to achieve a flat field (constant mod-B) which extends over the length of the central field region along the axis of symmetry and radially outward to form a uniformly distributed ECR plasma "volume." The magnetic field design strongly contrasts with those used in conventional ECR ion sources where the central field regions are approximately parabolic and the resulting ECR zones are "surfaces." The plasma confinement magnetic field mirror has a mirror ratio B-max/B-ECR of slightly greater than 2. The source is designed to operate at a nominal if frequency of 6 GHz. The central flat magnetic field region can be easily adjusted by mechanical means to tune the source to the resonant conditions within the limits of 5.5-6.8 GHz. The rf injection system is broadband to ensure excitation of transverse electric modes so that the rf power is largely concentrated in the resonant plasma volume which lies along and surrounds the axis of symmetry of the source. Because of the much larger ECR zone, the probability for absorption of microwave power is dramatically increased, thereby increasing the probability for acceleration of electrons, the electron temperature of the plasma, and, consequently, the "hot" electron population within the plasma volume of the source. The creation of an ECR "volume" rather than a "surface" is commensurate with higher charge states and higher beam intensities within a particular charge state. The source has also been designed so that it can be easily converted into a conventional magnetic field geometry source so that comparisons of the performances of the "volume" and "surface" forms of the source can be easily made. The design features of the source and rf injection system will be described In detail in this article. (C) 1998 American Institute of Physics. [S0034-6748(98)54602-3]. C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Liu, Y (reprint author), Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. NR 10 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 0034-6748 J9 REV SCI INSTRUM JI Rev. Sci. Instrum. PD MAR PY 1998 VL 69 IS 3 BP 1311 EP 1315 DI 10.1063/1.1148798 PG 5 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA ZC403 UT WOS:000072574500020 ER PT J AU Alton, GD Welton, RF Murray, SN Cui, B AF Alton, GD Welton, RF Murray, SN Cui, B TI The electron-beam plasma ion source as source of negative fluorine SO REVIEW OF SCIENTIFIC INSTRUMENTS LA English DT Article ID HALOGENS; FACILITY AB Radioactive ion beams (RIBs) of short-lived isotopes of fluorine are in demand for investigating astrophysical phenomena related to the hot CNO cycle and rp processes responsible for stellar nucleosynthesis. Since negative ion beams are required for injection into tandem electrostatic accelerators, such as the 25 MV tandem accelerator used for post acceleration of RIBs for the Holifield radioactive ion beam facility research program at the Oak Ridge National Laboratory, efficient, direct-formation F- ion sources are highly desirable. We have conceived and evaluated a direct extraction F- source for potential RIB applications which is predicated on the reverse polarity operation of a positive electron-beam-plasma target/ion source (EBPTIS) while simultaneously feeding fluorine-rich compounds and Cs vapor into the source. The source is found to operate in two separately distinct temperature regimes for the generation of F-: (1) a high cathode temperature regime or plasma mode and (2) a lower cathode temperature regime or surface ionization mode. For the latter mode of operation, net efficiencies of eta = 0.2% were attained for the EBPTIS; delay times, tau, attributable to the transport of F and fluoride compounds from the target to the ionization chamber of the source, typically, were found to be tau similar to 60 s. Brief descriptions of the EBPTIS and experimental techniques used in the studies, as well as net efficiency and effusive flow data for the negative EBPTIS, are presented in this article. (C) 1998 American Institute of Physics. [S0034-6748(98)65702-6]. C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. China Inst Atom Energy, Beijing, Peoples R China. RP Alton, GD (reprint author), Oak Ridge Natl Lab, POB 2008, Oak Ridge, TN 37831 USA. NR 28 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 0034-6748 J9 REV SCI INSTRUM JI Rev. Sci. Instrum. PD MAR PY 1998 VL 69 IS 3 BP 1327 EP 1331 DI 10.1063/1.1148800 PG 5 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA ZC403 UT WOS:000072574500023 ER PT J AU Anders, A Yushkov, G Oks, E Nikolaev, A Brown, I AF Anders, A Yushkov, G Oks, E Nikolaev, A Brown, I TI Ion charge state distributions of pulsed vacuum arc plasmas in strong magnetic fields SO REVIEW OF SCIENTIFIC INSTRUMENTS LA English DT Article ID JET AB Vacuum are plasmas with discharge currents of 300 A and duration 250 mu s have been produced in strong magnetic fields up to 4 T. Ion charge state distributions have been measured for C, Al, Ag, Ta, Pt, Ho, and Er with a time-of-flight charge-mass-spectrometer. Our previous measurements have been confirmed which show that ion charge states can be considerably enhanced when increasing the magnetic field up to about 1 T, The new measurements address the question of whether or not the additional increase continues at even higher magnetic field strength. It has been found that the increase becomes insignificant for field strengths greater than 1 T. Ion charge state distributions are almost constant for magnetic field strengths between 2 and 4 T. The results are explained by comparing the free expansion length with the freezing length, The most significant changes of charge state distributions are observed when these lengths are similar. (C) 1998 American Institute of Physics. [S0034-6748(98)61602-6]. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. Russian Acad Sci, Inst High Current Elect, Tomsk 634055, Russia. State Univ Control Syst & Radioelect, Tomsk 634055, Russia. RP Anders, A (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RI Oks, Efim/A-9409-2014; Anders, Andre/B-8580-2009; Yushkov, Georgy/O-8024-2015; Nikolaev, Alexey/R-2154-2016 OI Oks, Efim/0000-0002-9323-0686; Anders, Andre/0000-0002-5313-6505; Yushkov, Georgy/0000-0002-7615-6058; Nikolaev, Alexey/0000-0003-2724-3697 NR 16 TC 35 Z9 36 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 MAR PY 1998 VL 69 IS 3 BP 1332 EP 1335 DI 10.1063/1.1148801 PG 4 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA ZC403 UT WOS:000072574500024 ER PT J AU Anders, A Kuhn, M AF Anders, A Kuhn, M TI Characterization of a low-energy constricted-plasma source SO REVIEW OF SCIENTIFIC INSTRUMENTS LA English DT Article ID ION-SOURCE; HOLLOW; DISCHARGE; NITROGEN AB The construction and principle of operation of the constricted-plasma source are described. A supersonic plasma stream is produced by a special form of a de-glow discharge, the constricted glow discharge. The discharge current and gas flow pass through an orifice of small diameter (constriction) which causes a space charge double layer but also serves as a nozzle to gas-dynamically accelerate the plasma flow. Plasma parameters have been measured using Langmuir probes, optical emission spectroscopy, and a plasma monitor for mass-resolved energy measurements. Experiments have been done with nitrogen as the discharge gas. It was found that the energy distribution of both atomic and molecular ions have two peaks at about 5 and 15 eV, and the energy of almost all ions is less than 20 eV. The ionization efficiency decreases with increasing gas flow. The downstream plasma density is relatively low but activated species such as excited molecules and radicals contribute to film growth when the source is used for reactive film deposition. (C) 1998 American Institute of Physics. [S0034-6748(98)57302-9]. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. Tech Univ Chemnitz, Inst Phys, D-09107 Chemnitz, Germany. RP Anders, A (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 20 TC 35 Z9 35 U1 0 U2 4 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0034-6748 J9 REV SCI INSTRUM JI Rev. Sci. Instrum. PD MAR PY 1998 VL 69 IS 3 BP 1340 EP 1343 DI 10.1063/1.1148803 PG 4 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA ZC403 UT WOS:000072574500026 ER PT J AU Lin, SY Wang, L Zubrzycki, W AF Lin, SY Wang, L Zubrzycki, W TI Direct measurement of refractive-index dispersion using a time-delayed technique SO REVIEW OF SCIENTIFIC INSTRUMENTS LA English DT Article AB We describe a new way to measure the refractive index of dielectric materials using a time-resolved correlation method. By measuring the time delay of femtosecond pulse trains through a dielectric material, we obtain the refractive index of the material. This technique is direct, less surface sensitive, and precise to four digits. Consequently, it gives a true bulk index value. We apply this technique to measure the refractive index of fused silica, InP, and GaAs in the near infrared spectral regime. (C) 1998 American Institute of Physics. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Lin, SY (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. NR 9 TC 5 Z9 5 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 MAR PY 1998 VL 69 IS 3 BP 1472 EP 1475 DI 10.1063/1.1148794 PG 4 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA ZC403 UT WOS:000072574500048 ER PT J AU Gourley, PL AF Gourley, PL TI Nanolasers SO SCIENTIFIC AMERICAN LA English DT Article C1 Sandia Natl Labs, Livermore, CA 94550 USA. RP Gourley, PL (reprint author), Sandia Natl Labs, Livermore, CA 94550 USA. NR 6 TC 17 Z9 17 U1 0 U2 3 PU SCI AMERICAN INC PI NEW YORK PA 415 MADISON AVE, NEW YORK, NY 10017 USA SN 0036-8733 J9 SCI AM JI Sci.Am. PD MAR PY 1998 VL 278 IS 3 BP 56 EP 61 PG 6 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA YX866 UT WOS:000072087500026 PM 9487703 ER PT J AU Klawonn, A AF Klawonn, A TI An optimal preconditioner for a class of saddle point problems with a penalty term SO SIAM JOURNAL ON SCIENTIFIC COMPUTING LA English DT Article DE mixed finite elements; saddle point problems; penalty term; nearly incompressible materials; elasticity; preconditioned conjugate residual method; domain decomposition; multigrid ID FINITE-ELEMENT APPROXIMATION; MULTILEVEL SCHWARZ METHODS; STABILIZED STOKES SYSTEMS; PLANAR LINEAR ELASTICITY; FAST ITERATIVE SOLUTION; MIXED MULTIGRID METHOD; ELLIPTIC PROBLEMS; 3 DIMENSIONS; DISCONTINUOUS COEFFICIENTS; INDEFINITE SYSTEMS AB Iterative methods are considered for a class of saddle point problems with a penalty term arising from finite element discretizations of certain elliptic problems. An optimal preconditioner which is independent of the discretization and the penalty parameter is constructed. This approach is then used to design an iterative method with a convergence rate bounded independently of the Lame parameters occurring in the equations of linear elasticity. C1 Univ Munster, Inst Numer & Instrumentelle Math, D-48149 Munster, Germany. NYU, Courant Inst, New York, NY USA. Argonne Natl Lab, Argonne, IL 60439 USA. RP Klawonn, A (reprint author), Univ Munster, Inst Numer & Instrumentelle Math, Einsteinstr 62, D-48149 Munster, Germany. RI Klawonn, Axel/P-8705-2014 NR 47 TC 60 Z9 60 U1 0 U2 4 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 MAR PY 1998 VL 19 IS 2 BP 540 EP 552 DI 10.1137/S1064827595279575 PG 13 WC Mathematics, Applied SC Mathematics GA YW920 UT WOS:000071988000013 ER PT J AU Czyzyk, J Fourer, R Mehrotra, S AF Czyzyk, J Fourer, R Mehrotra, S TI Using a massively parallel processor to solve large sparse linear programs by an interior-point method SO SIAM JOURNAL ON SCIENTIFIC COMPUTING LA English DT Article DE parallel computation; linear programming; large-scale optimization; interior-point methods ID SYMMETRICAL INDEFINITE SYSTEMS AB Most implementations of interior-point methods for linear programming rely on some form of elimination to solve the key equation system or systems at each iteration. Although these systems are typically very sparse, a substantial dense block often arises as the elimination proceeds. We describe a strategy that uses a serial "front-end" computer to carry out the sparse part of the elimination and a massively parallel processor to complete the elimination on the dense block. Through computational tests, we show that two such computers working together can solve hard linear programs much faster than either could alone. We conclude that our strategy is technically feasible now but that its components will have to be closer to the state of the art-in both serial and parallel processing-for it to be feasible in an economic sense. C1 Argonne Natl Lab, Div Math & Comp Sci, Argonne, IL 60439 USA. Northwestern Univ, Dept Ind Engn & Management Sci, Evanston, IL 60208 USA. RP Czyzyk, J (reprint author), Argonne Natl Lab, Div Math & Comp Sci, 9700 S Cass Ave, Argonne, IL 60439 USA. RI Fourer, Robert/A-9455-2009; Fourer, Robert/B-7459-2009; Mehrotra, Sanjay/B-7477-2009 NR 21 TC 4 Z9 4 U1 0 U2 0 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 MAR PY 1998 VL 19 IS 2 BP 553 EP 565 DI 10.1137/S1064827594272086 PG 13 WC Mathematics, Applied SC Mathematics GA YW920 UT WOS:000071988000014 ER PT J AU Seaman, JC AF Seaman, JC TI Retardation of fluorobenzoate tracers in highly weathered soil and groundwater systems SO SOIL SCIENCE SOCIETY OF AMERICA JOURNAL LA English DT Article ID ASH-DERIVED SOILS; NONREACTIVE TRACERS; ORGANIC COMPOUNDS; HYDROUS OXIDES; SOLUTE SIZE; ADSORPTION; TRANSPORT; BENZOATE; WATER; SALICYLATE AB Fluorobenzoate (FBA) compounds have been used extensively as hydrologic tracers based on the assumption that they are not significantly sorbed or degraded in most soil and groundwater environments, However, previous hatch studies have indicated that such compounds may be readily sorbed by organic matter and hydrous Fe oxides, such as goethite, This study was conducted to evaluate the transport properties os' FBA tracers within the highly weathered sediments of the southeastern Coastal Plain, Repacked columns of coarse-textured alluvial soil and aquifer sediments were leached with tracer solutions (pH approximate to 5.0) containing various fluorobenzoates with negative logs of the acid dissociation constants (pK(a)s) ranging from 3.83 to 2.85, Bromide was included in many of the solutions to evaluate the influence of ionic strength and competition For anion-exchange sites on FBA mobility. Despite possible differences in the mechanisms of sorption, retardation within surface and subsurface materials increased with increasing pK(a) of a given FBA compound, Retardation was attributed to partitioning to the organic fraction for the surface soil and to sorption by Fe oxides for the subsurface sample. Far the transport of mixed-benzoate solutions through surface soil, 2,6-di-FBA, 2,3,4,5- tetra-FBA, and Br- yielded transport velocities consistent with those observed for H-3; however, 3,4,5-tri-FBA and 3,4-di-FBA were significantly retarded, most likely due to partitioning to the organic fraction, For the subsurface sample, all of the PEA tracers and Br- were retarded compared with H-3, with FBA retardation increasing with pK(a). At higher ionic strengths, retardation was reduced in the subsurface sample due to competition with Br for anion sorption sites. C1 Univ Georgia, Savannah River Ecol Lab, Adv Analyt Ctr Environm Sci, Aiken, SC 29802 USA. RP Seaman, JC (reprint author), Univ Georgia, Savannah River Ecol Lab, Adv Analyt Ctr Environm Sci, Drawer E, Aiken, SC 29802 USA. NR 35 TC 17 Z9 18 U1 1 U2 3 PU SOIL SCI SOC AMER PI MADISON PA 677 SOUTH SEGOE ROAD, MADISON, WI 53711 USA SN 0361-5995 J9 SOIL SCI SOC AM J JI Soil Sci. Soc. Am. J. PD MAR-APR PY 1998 VL 62 IS 2 BP 354 EP 361 PG 8 WC Soil Science SC Agriculture GA ZJ690 UT WOS:000073242700010 ER PT J AU Rubin, M Von Rottkay, K Powles, R AF Rubin, M Von Rottkay, K Powles, R TI Window optics SO SOLAR ENERGY LA English DT Article ID GLASSES AB Optical and radiative properties of glazing materials are primary inputs for determination of energy performance in buildings. This paper revisits the problem and reformulates the calculations to encompass a variety of solutions to practical problems in window optics. Properties of composite systems such as flexible films applied to rigid glazing and laminated glazing can be predicted from measurements on isolated components in air or other gases. Properties of a series of structures can be generated from those of a base structure. For example, the measured properties of a coated or uncoated substrate can be extended to a range of available substrate thicknesses without the need to measure each thickness. Similarly, a coating type could be transferred by calculation to any other substrate. A simple monolithic model for extrapolating from normal properties to oblique properties is shown to have sufficient accuracy for the purpose of annual energy performance calculations; A process is initiated to develop a reliable method for determination of effective indices suitable for more detailed spectral and directional optical calculations. (C) 1998 Elsevier Science Ltd. All rights reserved. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. Univ Giessen, Inst Phys 1, D-35392 Giessen, Germany. Univ Sydney, Sch Phys, Sydney, NSW 2006, Australia. RP Rubin, M (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, 1 Cyclotron Rd,MS 2-300, Berkeley, CA 94720 USA. RI Powles, Rebecca/C-4272-2008 NR 27 TC 35 Z9 36 U1 0 U2 3 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0038-092X J9 SOL ENERGY JI Sol. Energy PD MAR PY 1998 VL 62 IS 3 SI SI BP 149 EP 161 DI 10.1016/S0038-092X(98)00010-3 PG 13 WC Energy & Fuels SC Energy & Fuels GA ZV758 UT WOS:000074338200002 ER PT J AU Smith, GB Dligatch, S Sullivan, R Hutchins, MG AF Smith, GB Dligatch, S Sullivan, R Hutchins, MG TI Thin film angular selective glazing SO SOLAR ENERGY LA English DT Article ID OPTICAL-PROPERTIES; CR FILMS; TRANSMITTANCE; METAL; COMPOSITES; ALUMINUM AB Angular selective glazing based on special obliquely deposited thin films, has considerable potential for optimizing the overall performance of a window in temperate to hot climates. In contrast to most currently used glazings for these environments it has the ability to control solar heat gain and glare while providing a clear view through the window and considerable but not excessive light gain. Various deposition techniques and film materials will be discussed and the spectral and integrated optical performance of single and double-layered systems presented for various directions of incidence. Full optical characterisation requires measurements for incidence directions over half a hemisphere. Some of this is presented but most data is confined to planes of incidence where angular selectivity is greatest as determined by deposition geometry. Two layer systems are designed to provide a low emittance and better solar control than the single layer systems while retaining good visible angular selectivity. The single layers are primarily to provide angular selective control of the visual radiation since they have moderately high transmittance in the near infrared and a high emittance. Theoretical models used to extract structural information and model the complex optical properties are introduced and their predictions assessed. Preliminary results on simulation of the performance of Full size angular selective windows in comparison to other types of solar control glazing such as low e heavily tinted windows are discussed in terms of their relative impact on cooling load, lighting contribution, glare control and total energy savings. (C) 1998 Elsevier Science Ltd. All rights reserved. C1 Univ Technol Sydney, Dept Appl Phys, Broadway, NSW 2007, Australia. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. Oxford Brookes Univ, Sch Engn, Oxford OX3 0BP, England. RP Smith, GB (reprint author), Univ Technol Sydney, Dept Appl Phys, POB 123, Broadway, NSW 2007, Australia. RI Smith, Geoff/A-6639-2012 OI Smith, Geoff/0000-0002-6985-2880 NR 37 TC 26 Z9 26 U1 2 U2 8 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0038-092X J9 SOL ENERGY JI Sol. Energy PD MAR PY 1998 VL 62 IS 3 SI SI BP 229 EP 244 DI 10.1016/S0038-092X(98)00009-7 PG 16 WC Energy & Fuels SC Energy & Fuels GA ZV758 UT WOS:000074338200008 ER PT J AU Wu, CH Zory, PS Emanuel, MA AF Wu, CH Zory, PS Emanuel, MA TI Abnormal lasing behaviors in thin p-clad InGaAs quantum well lasers SO SOLID-STATE ELECTRONICS LA English DT Article ID THRESHOLD CURRENT AB Thin p-clad (250 nm) InGaAs quantum well (QW) lasers with 200 nm p(+)-GaAs cap layer thickness and various device configurations are studied. For wide stripe (w = 50 mu m) lasers, abnormal lasing characteristics of very high thresholds, current on-time dependent lasing and micro-second long delays are observed. With 300 nm ridge-height, micro-second long lasing delays are found in w = 6 mu m lasers, and Q-switching in w = 2.5 mu m and 3.5 mu m lasers, respectively. The unusual lasing behaviors are attributed to the decrease of transverse optical confinement caused by the increase of p(+)-GaAs cap layer thickness. To improve device performance and eliminate lasing delay, p(+)-GaAs cap layer thickness of wide stripe lasers and stripe width of narrow stripe devices have to be not greater than 170 nm and 1.5 mu m, respectively, in thin p-clad (250 nm) laser structure. (C) 1998 Published by Elsevier Science Ltd. All rights reserved. C1 Inst Nucl Energy Res, Tao Yuan 325, Taiwan. Univ Florida, Dept Elect Engn, Gainesville, FL 32611 USA. Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Wu, CH (reprint author), Inst Nucl Energy Res, POB 3-11, Tao Yuan 325, Taiwan. NR 13 TC 0 Z9 0 U1 0 U2 0 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 MAR PY 1998 VL 42 IS 3 BP 405 EP 410 DI 10.1016/S0038-1101(97)00205-0 PG 6 WC Engineering, Electrical & Electronic; Physics, Applied; Physics, Condensed Matter SC Engineering; Physics GA ZJ337 UT WOS:000073203900017 ER PT J AU Zhang, Z Hammel, PC AF Zhang, Z Hammel, PC TI Magnetic resonance force microscopy with a ferromagnetic tip mounted on the force detector SO SOLID STATE NUCLEAR MAGNETIC RESONANCE LA English DT Article DE magnetic resonance force microscopy; mechanical detection; cantilever; force microscopy; electron spin resonance; nuclear magnetic resonance; ferromagnetic resonance; magnetic resonance imaging ID MECHANICAL DETECTION AB The Magnetic Resonance Force Microscope (MRFM) presents the opportunity for a magnetic resonance imaging probe with ultra-high, potentially atomic-scale, resolution. The successful application of this technique in detection of nuclear magnetic, electron-spin and ferromagnetic resonance (FMR) highlights its significant potential. We discuss the capabilities of the MRFM with particular emphasis on the detection of FMR using MRFM techniques. A crucial remaining challenge in the development of the magnetic resonance force microscope (MRFM) is to place the magnetic probe on the mechanical resonator. We address the problem of spurious detector response arising from interactions between the magnetic tip and various external applied fields. We show that miniature, magnetically-polarized Nd2Fe14B particles show promise as magnetic probe tips. Our experience indicates it will be important to minimize the total polarized moment of the magnetic tip and to ensure that the applied fields are as uniform as possible. (C) 1998 Elsevier Science B.V. C1 Univ Calif Los Alamos Natl Lab, Condensed Matter & Thermal Phys Grp, Los Alamos, NM 87545 USA. Univ Calif Los Alamos Natl Lab, Ctr Nonlinear Studies, Los Alamos, NM 87545 USA. RP Hammel, PC (reprint author), Univ Calif Los Alamos Natl Lab, Condensed Matter & Thermal Phys Grp, POB 1663, Los Alamos, NM 87545 USA. RI Hammel, P Chris/O-4845-2014 OI Hammel, P Chris/0000-0002-4138-4798 NR 15 TC 17 Z9 17 U1 0 U2 9 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0926-2040 J9 SOLID STATE NUCL MAG JI Solid State Nucl. Magn. Reson. PD MAR PY 1998 VL 11 IS 1-2 SI SI BP 65 EP 72 DI 10.1016/S0926-2040(97)00097-0 PG 8 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical; Physics, Condensed Matter; Spectroscopy SC Chemistry; Physics; Spectroscopy GA ZT411 UT WOS:000074083000007 PM 9650791 ER PT J AU Augustine, MP TonThat, DM Clarke, J AF Augustine, MP TonThat, DM Clarke, J TI SQUID detected NMR and NQR SO SOLID STATE NUCLEAR MAGNETIC RESONANCE LA English DT Article DE dc SQUID; Optical Pumping; NMR; NQR; spin-echo ID QUANTUM INTERFERENCE DEVICE; NUCLEAR-QUADRUPOLE RESONANCE; ROOM-TEMPERATURE SAMPLES; INTEGRATED DC SQUID; MAGNETIC-RESONANCE; MAGNETOMETER; N-14; SPECTROMETER; FIELD; SPECTROSCOPY AB The dc Superconducting QUantum Interference Device (SQUID) is a sensitive detector of magnetic flux, with a typical flux noise of the order 1 mu Phi(0) Hz(-1/2) at liquid helium temperatures. Here Phi(0) = (h) over bar/2e is the flux quantum. In our NMR or NQR spectrometer, a niobium wire coil wrapped around the sample is coupled to a thin film superconducting coil deposited on the SQUID to form a flux transformer. With this untuned input circuit the SQUID measures the flux, rather than the rate of change of flux, and thus retains its high sensitivity down to arbitrarily low frequencies. This feature is exploited in a cw spectrometer that monitors the change in the static magnetization of a sample induced by radio frequency irradiation. Examples of this technique are the detection of NQR in Al-27 in sapphire and B-11 in boron nitride, and a level crossing technique to enhance the signal of N-14 in peptides. Research is now focused on a SQUID-based spectrometer for pulsed NQR and NMR, which has a bandwidth of 0-5 MHz. This spectrometer is used with spin-echo techniques to measure the NQR longitudinal and transverse relaxation times of N-14 in NH4ClO4, 63 +/- 6 ms and 22 +/- 2 ms, respectively. With the aid of two-frequency pulses to excite the 359 kHz and 714 kHz resonances in ruby simultaneously, it is possible to obtain a two-dimensional NQR spectrum. As a third example, the pulsed spectrometer is used to study NMR spectrum of Xe-129 after polariza-tion with optically pumped Rb. The NMR line can be detected at frequencies as low as 200 Hz. At fields below about 2 mT the longitudinal relaxation time saturates at about 2000 s. Two recent experiments in other laboratories have extended these pulsed NMR techniques to higher temperatures and smaller samples. In the first, images were obtained of mineral oil floating on water at room temperature. In the second, a SQUID configured as a thin film gradiometer was used to detect NMR in a 50 mu m particle of Pt-195 at 6 mT and 4.2 K. (C) 1998 Elsevier Science B.V. C1 Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Dept Mat Sci, Berkeley, CA 94720 USA. RP Augustine, MP (reprint author), Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. NR 73 TC 14 Z9 15 U1 2 U2 14 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0926-2040 J9 SOLID STATE NUCL MAG JI Solid State Nucl. Magn. Reson. PD MAR PY 1998 VL 11 IS 1-2 SI SI BP 139 EP 156 DI 10.1016/S0926-2040(97)00103-3 PG 18 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical; Physics, Condensed Matter; Spectroscopy SC Chemistry; Physics; Spectroscopy GA ZT411 UT WOS:000074083000013 PM 9650797 ER PT J AU Kramer, JA Adams, MD Singh, GB Doggett, NA Krawetz, SA AF Kramer, JA Adams, MD Singh, GB Doggett, NA Krawetz, SA TI A matrix associated region localizes the human SOCS-1 gene to chromosome 16p13.13 SO SOMATIC CELL AND MOLECULAR GENETICS LA English DT Article ID NUCLEAR MATRIX; ATTACHMENT REGIONS; SITES; DOMAIN; CELLS AB The MarFinder algorithm was applied to a newly sequenced segment of 16p13,13 abutting the 3' end of the human PRM1 --> PRM2 --> TNP2 locus. A candidate region of matrix attached was identified. Subsequent biophysical analysis showed that this region was attached to the somatic nuclear matrix. Nucleotide sequence analysis also revealed the presence of a CpG island. Data base queries showed that this region contained the SOCS-1 gene. Thus, the SOCS-1 gene is bounded by a somatic MAR and is just 3' of the spermatid-expressed PRM1 --> PRM2 --> TNP2 domain at position 16p13.13. C1 Wayne State Univ, Sch Med, Ctr Mol Med & Genet, Dept Obstet & Gynecol, Allen Park, MI 48101 USA. Oakland Univ, Dept Comp Sci & Engn, Rochester, MI 48309 USA. Univ Calif Los Alamos Natl Lab, Ctr Human Genome Studies, Los Alamos, NM 87545 USA. RP Krawetz, SA (reprint author), Wayne State Univ, Sch Med, Ctr Mol Med & Genet, Dept Obstet & Gynecol, 275 E Hancock, Allen Park, MI 48101 USA. NR 15 TC 13 Z9 13 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 MAR PY 1998 VL 24 IS 2 BP 131 EP 133 DI 10.1023/B:SCAM.0000007115.58601.87 PG 3 WC Biochemistry & Molecular Biology; Cell Biology; Genetics & Heredity SC Biochemistry & Molecular Biology; Cell Biology; Genetics & Heredity GA 158EH UT WOS:000078102700005 PM 9919312 ER PT J AU Wolpert, DH Knill, E Grossman, T AF Wolpert, DH Knill, E Grossman, T TI Some results concerning off-training-set and IID error for the Gibbs and the Bayes optimal generalizers SO STATISTICS AND COMPUTING LA English DT Article DE Supervised learning; learning curves; off-training-set; Bayes-optimal; Gibbs; IID AB In this paper we analyse the average behaviour of the Bayes-optimal and Gibbs learning algorithms. We do this both for off-training-set error and conventional IID (independent identically distributed) error (for which test sets overlap with training sets). For the IID case we provide a major extension to one of the better known results. We also show that expected IID test set error is a non-increasing function of training set size for either algorithm. On the other hand, as we show, the expected off-training-set error for both learning algorithms can increase with training set size, for non-uniform sampling distributions. We characterize the relationship the sampling distribution must have with the prior for such an increase. We show in particular that for uniform sampling distributions and either algorithm, the expected off-training-set error is a non-increasing function of training set size. For uniform sampling distributions, we also characterize the priors for which the expected error of the Bayes-optimal algorithm stays constant. In addition we show that for the Bayes-optimal algorithm, expected off-training-set error can increase with training set size when the target function is fixed, but if and only if the expected error averaged over all targets decreases with training set size. Our results hold for arbitrary noise and arbitrary loss functions. 0960-3174 (C) 1998 Chapman & Hall. C1 NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. Univ Calif Los Alamos Natl Lab, CIC 3 Comp Res & Applicat, Los Alamos, NM 87545 USA. Univ Calif Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. Univ Calif Los Alamos Natl Lab, CNLS, Los Alamos, NM 87545 USA. NR 24 TC 0 Z9 0 U1 1 U2 1 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0960-3174 J9 STAT COMPUT JI Stat. Comput. PD MAR PY 1998 VL 8 IS 1 BP 35 EP 54 DI 10.1023/A:1008867009312 PG 20 WC Computer Science, Theory & Methods; Statistics & Probability SC Computer Science; Mathematics GA ZC249 UT WOS:000072557900004 ER PT J AU Zemek, J Hucek, S Jablonski, A Tilinin, IS AF Zemek, J Hucek, S Jablonski, A Tilinin, IS TI Escape probability of s-photoelectrons leaving aluminium and copper oxides SO SURFACE AND INTERFACE ANALYSIS LA English DT Article DE escape probability of photoelectrons; depth distribution function; overlayer experiment; inelastic and elastic electron scattering ID ANGULAR-DISTRIBUTION; DEPTH PROFILES; SIGNAL ELECTRONS; SURFACE-ANALYSIS; SPECTROSCOPY; SOLIDS; XPS; PHOTOEMISSION; DECONVOLUTION; ATTENUATION AB The escape probability of O 1s and Al 2s photoelectrons from Al2O3 and CuO overlayers grown an Al and Cu substrates, respectively, has been studied as a function of photoelectron depth of origin and emission direction. Escape probabilitics have been determined experimentally, analytically and by a Monte Carlo method. The analytical approach is based an solution of a kinetic equation satisfying appropriate boundary conditions. Both the Monte Carlo calculations and analytical theory account properly for multiple elastic and inelastic scattering of photoelectrons on their way out of the target, The results are compared with those of the straight-line approximation (SLA), where elastic scattering is neglected. It has been found experimentally that the escape probability as a function of depth of origin for the O 1s photoelectrons leaving Al2O3 surface at an emission angle of 60 degrees with respect to the incident x-ray beam direction can be approximated by an exponential function. In contrast, the escape probability of s-photoelectrons in a direction close to that of x-ray propagation exhibits non-monotinic behaviour, with a maximum at a depth of 4-10 Angstrom, The experimental data agree well with the predictions of Monte Carlo simulations and analytical theory, and differ noticeably from the SLA results. (C) 1998 John Wiley & Sons, Ltd. C1 Acad Sci Czech Republ, Inst Phys, CR-16200 Prague 6, Czech Republic. Polish Acad Sci, Inst Phys Chem, PL-01224 Warsaw, Poland. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. RP Zemek, J (reprint author), Acad Sci Czech Republ, Inst Phys, Cukrovarnicka 10, CR-16200 Prague 6, Czech Republic. EM zemek@fzu.cz RI Zemek, Josef/G-6203-2014 NR 33 TC 22 Z9 22 U1 1 U2 5 PU JOHN WILEY & SONS LTD PI W SUSSEX PA BAFFINS LANE CHICHESTER, W SUSSEX PO19 1UD, ENGLAND SN 0142-2421 J9 SURF INTERFACE ANAL JI Surf. Interface Anal. PD MAR PY 1998 VL 26 IS 3 BP 182 EP 187 DI 10.1002/(SICI)1096-9918(199803)26:3<182::AID-SIA358>3.0.CO;2-Z PG 6 WC Chemistry, Physical SC Chemistry GA ZD823 UT WOS:000072728000002 ER PT J AU Fairbrother, DH Roberts, JG Somorjai, GA AF Fairbrother, DH Roberts, JG Somorjai, GA TI The growth of magnesium chloride monolayer and multilayer structures on different transition metal (Pt, Pd, Rh) single crystals with varied orientations SO SURFACE SCIENCE LA English DT Article DE low energy electron diffraction (LEED); magnesium chloride ID EPITAXIAL-GROWTH; FILMS; SURFACE; OXIDE; MO(110); PT(111); FACES; LEED; GOLD AB The growth of magnesium chloride (MgCl2) monolayer and multilayer structures on a variety of transition metal single crystal surfaces [Pd(111) and (100), Pt(111) and (100)-hex and Rh(111)] has been studied. Low energy electron diffraction (LEED) has been employed as a probe of the long range order at both monolayer and multilayer coverages while temperature programmed desorption (TPD) provided information on the strength of adsorbate-substrate interactions. LEED results indicated that MgCl2 growth at both monolayer and multilayer coverages is dependent upon the magnitude of the monolayer adsorbate-substrate interactions which are themselves a function of the underlying single crystal template. LEED results indicated that, on each transition metal surface studied, the MgCl2 monolayer structures act as a template for subsequent multilayer structures. On Pt(111) and Pd(111), identical, well ordered LEED structures at both monolayer and multilayer coverages, were produced. The commensurate (4x4) and (root 13x root 13)R13.9 degrees monolayer structures were associated with expansions and contractions in the MgCl2 unit cell dimension, respectively. These structural changes were correlated with the strength of the monolayer adsorbate-substrate interaction, which on these surfaces lead to distinct monolayer TPD features. in contrast, MgCl2 growth on Pt(100)-hex and Pd(100) exhibited more complex LEED patterns associated with various degrees of ordered and rotationally disordered domains. This was attributed to a reduction in the magnitude of monolayer adsorbate-substrate interactions, correlated by TPD measurements. Experiments on Rh(111) indicate that the factors responsible for ordered MgCl2 growth on this surface differ from those observed on Pt and Pd single crystals. In general, better matching between the substrate and adsorbate unit cell dimensions leads to enhanced adsorbate-substrate interactions which are responsible for the degree of ordering at monolayer and subsequent multilayer coverages. (C) 1998 Elsevier Science B.V. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. RP Somorjai, GA (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. EM somorjai@cchem.berkeley.edu NR 21 TC 26 Z9 26 U1 1 U2 9 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0039-6028 J9 SURF SCI JI Surf. Sci. PD MAR 1 PY 1998 VL 399 IS 1 BP 109 EP 122 DI 10.1016/S0039-6028(97)00816-9 PG 14 WC Chemistry, Physical; Physics, Condensed Matter SC Chemistry; Physics GA ZD644 UT WOS:000072708000013 ER PT J AU Roberts, JG Gierer, M Fairbrother, DH Van Hove, MA Somorjai, GA AF Roberts, JG Gierer, M Fairbrother, DH Van Hove, MA Somorjai, GA TI Quantitative LEED analysis of the surface structure of a MgCl2 thin film grown on Pd(111) SO SURFACE SCIENCE LA English DT Article DE catalysis; chlorides; chlorine; compound formation; electron-solid interactions, scattering, diffraction; low energy electron diffraction (LEED); low index single crystal surfaces; magnesium ID ENERGY ELECTRON-DIFFRACTION; CRYSTALLOGRAPHY AB An epitaxial, ultrathin single-crystal film (12 Angstrom) of MgCl2 was deposited molecularly onto a Pd single crystal of (111) orientation at a crystal temperature of similar to 650 K. A detailed surface structure determination of this insulating him was performed by low-energy electron diffraction (LEED). A low incident LEED beam current (0.36 mu A) was employed to minimize the electron-stimulated desorption (ESD) of Cl. The best-fit model for the observed hexagonal MgCl2(1x1) pattern corresponds to the unreconstructed (0001) Cl-terminated plane of alpha-MgCl2, whose stacking sequence is Cl-Mg-Cl-Cl-Mg-Cl..., with a Pendry R-factor of 0.317. Small relaxations of the surface were found as 0.03+/-0.03, 0.03+/-0.04 and 0.04+/-0.08 Angstrom expansions of the first three Mg-Cl interlayer spacings, respectively, and a 0.10+/-0.06 Angstrom contraction of the first Cl-Cl interlayer spacing. These small deviations were probably driven by the loss of the van der Waals interaction at the termination plane, since surface structure data for transition-metal dichalcogenides, which have different intralayer bonding, but the same intertrilayer bonding, report a similar magnitude of interlayer spacing deviations as seen in MgCl2. (C) 1998 Elsevier Science B.V. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. RP Van Hove, MA (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. RI Van Hove, Michel/A-9862-2008 OI Van Hove, Michel/0000-0002-8898-6921 NR 13 TC 12 Z9 12 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0039-6028 J9 SURF SCI JI Surf. Sci. PD MAR 1 PY 1998 VL 399 IS 1 BP 123 EP 128 DI 10.1016/S0039-6028(97)00838-8 PG 6 WC Chemistry, Physical; Physics, Condensed Matter SC Chemistry; Physics GA ZD644 UT WOS:000072708000014 ER PT J AU Kuusinen, TL Barker, RH Alexander, DA AF Kuusinen, TL Barker, RH Alexander, DA TI Life cycle assessment in woven textiles SO TAPPI JOURNAL LA English DT Article DE analysis; computer programs; cost control; fabric; life cycle; North America; textiles; USA; woven fabric AB The cycle assessment can evaluate th system-wide effects of product and process design options. Software development is streamlining and reducing the cost of life cycle assessments in the textile industry. One environmental decision support tool builds on the experience of life cycle assessment of textile products such as the inventory analysis of a woman's 100% polyester blouse. Other types of product evaluations might include analysis of the proposed eco-labeling systems being considered overseas that may pose trade barriers to the import of U.S. textiles. Additional uses include analysis of the cost of resource losses and opportunities for improving the system-wide cost-effectiveness of the integrated U.S. textile industry. C1 Pacific NW Lab, Richland, WA 99352 USA. Amer Fiber Manufacturers Assoc, Washington, DC 20036 USA. Inst Text Technol, AMTEX TREC Project, Spartanburg, SC 29301 USA. RP Kuusinen, TL (reprint author), Pacific NW Lab, Batelle Blvd, Richland, WA 99352 USA. NR 0 TC 2 Z9 2 U1 1 U2 3 PU TECH ASSN PULP PAPER IND INC PI NORCROSS PA 15 TECHNOLOGY PARK SOUTH, NORCROSS, GA 30092 USA SN 0734-1415 J9 TAPPI J JI TAPPI J. PD MAR PY 1998 VL 81 IS 3 BP 179 EP 182 PG 4 WC Materials Science, Paper & Wood SC Materials Science GA ZB621 UT WOS:000072490900031 ER PT J AU O'Flaherty, EJ Inskip, MJ Franklin, CA Durbin, PW Manton, WI Baccanale, CL AF O'Flaherty, EJ Inskip, MJ Franklin, CA Durbin, PW Manton, WI Baccanale, CL TI Evaluation and modification of a physiologically based model of lead kinetics using data from a sequential isotope study in cynomolgus monkeys SO TOXICOLOGY AND APPLIED PHARMACOLOGY LA English DT Article ID BONE-SEEKING ELEMENTS; QUANTITATIVE MEASUREMENTS; MACACA-FASCICULARIS; TRABECULAR BONE; BLOOD LEAD; RAT FEMUR; ABSORPTION; HUMANS; MOBILIZATION; DISPOSITION AB Endogenous (predominantly bone) and exogenous lead were differentially labeled in two 11-year-old female cynomolgus monkeys (Macaca fascicularis) to establish the contributions of the two sources to blood lead, The monkeys had been administered a common lead isotope "mix" at the rate of about 1300 mu g Pb/kg body wt/day from age 10 months until the start of the study, On day 0, common lead was replaced in sequence by mixes artificially enriched in Pb-204, Pb-206, and Pb-207, given for periods of from 50 to 281 days. Total lead ingestion rate was held constant except during administration of the Pb-207-enriched mix to one of the monkeys, when it was reduced to 650 mu g/kg/day. Blood and bone were sampled at intervals and analyzed for their content of each of the isotope mixes, A physiologically based model of human lead kinetics was scaled to the cynomolgus monkey and fit to the data to test the correctness of the model structure and to assist with interpretation of study results, Fractional absorption was varied to achieve the best visual fits of the scaled model to blood and bone concentration data for each monkey, The model failed to reproduce the sharp drop in isotope concentrations in blood observed after each exchange of isotope mix, Consequently, it was revised to include a rapid-turnover trabecular bone compartment and a slow-turnover cortical bone compartment, using estimates of trabecular and cortical bone turnover rates from histomorphometric studies in adult cynomolgus monkeys. The revised model fit most of the sets of bone and blood concentrations well, About 17% of the blood lead originated from bone after 11 years of exposure, at blood lead concentrations in excess of 50 mu g/dl. The rate of return of common lead from bone, as estimated from the model, was 28 mu g/day just before termination of controlled common lead exposure on day 0, Based on the success of the scaled human model in fitting these data and on the absolute and relative values of bone and blood lead concentrations, the metabolism of lead in the cynomolgus monkey appears to be similar to human lead metabolism. (C) 1998 Academic Press. C1 Univ Cincinnati, Coll Med, Cincinnati, OH 45221 USA. Hlth Canada, Environm Hlth Directorate, Hlth Protect Branch, Ottawa, ON K1A 0L2, Canada. Hlth Canada, Pest Management Regulatory Agcy, Ottawa, ON K1A 0L2, Canada. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. Univ Texas, Mass Spectrometry Lab, Richardson, TX USA. RP O'Flaherty, EJ (reprint author), Univ Cincinnati, Coll Med, Cincinnati, OH 45221 USA. FU NIEHS NIH HHS [N01-ES-05285] NR 49 TC 26 Z9 26 U1 0 U2 2 PU ACADEMIC PRESS INC PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0041-008X J9 TOXICOL APPL PHARM JI Toxicol. Appl. Pharmacol. PD MAR PY 1998 VL 149 IS 1 BP 1 EP 16 DI 10.1006/taap.1997.8328 PG 16 WC Pharmacology & Pharmacy; Toxicology SC Pharmacology & Pharmacy; Toxicology GA ZA337 UT WOS:000072353400001 PM 9512721 ER PT J AU Doyle, JL Stubbs, L AF Doyle, JL Stubbs, L TI Ataxia, arrhythmia and ion-channel gene defects SO TRENDS IN GENETICS LA English DT Review ID LONG QT SYNDROME; MUSCLE CHLORIDE CHANNEL; POTASSIUM CHANNEL; GLYCINE RECEPTOR; CARDIAC-ARRHYTHMIA; PERIODIC PARALYSIS; MISSENSE MUTATION; ALPHA-4 SUBUNIT; MOLECULAR-BASIS; K+ CHANNELS AB Ion channels are essential to a wide range of physiological functions including neuronal signaling, muscle contraction cardiac pacemaking, hormone secretion and cell proliferation The important role that highly regulated ion influx plays In these processes has been underscored by a recent flurry of discovered linking ion-channel gene mutations to inherited disorders. Ion channels of many, different types hare been demonstrated as being causative factors. In genetic disease This review discusses the growing number of disorders associated with genes of the voltage-gated ion channel superfamily with special focus on those characterized by neurological, neuromuscular, or cardiac dysfunction in humans and mice. C1 Oak Ridge Natl Lab, Div Life Sci, Oak Ridge, TN 37831 USA. RP Doyle, JL (reprint author), NIHGR, NIH, Bethesda, MD 20892 USA. EM jdoyle@venus.nhgri.nih.gov; stubbs5@llnl.gov OI Stubbs, Lisa/0000-0002-9556-1972 NR 56 TC 38 Z9 38 U1 0 U2 0 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0168-9525 J9 TRENDS GENET JI Trends Genet. PD MAR PY 1998 VL 14 IS 3 BP 92 EP 98 DI 10.1016/S0168-9525(97)01370-X PG 7 WC Genetics & Heredity SC Genetics & Heredity GA ZB856 UT WOS:000072514900004 PM 9540405 ER PT J AU He, SY AF He, SY TI On the origin and function of pili - Response from He SO TRENDS IN MICROBIOLOGY LA English DT Letter C1 Michigan State Univ, DOE Plant Res Lab, E Lansing, MI 48824 USA. RP He, SY (reprint author), Michigan State Univ, DOE Plant Res Lab, E Lansing, MI 48824 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0966-842X J9 TRENDS MICROBIOL JI Trends Microbiol. PD MAR PY 1998 VL 6 IS 3 BP 99 EP 99 DI 10.1016/S0966-842X(98)01223-2 PG 1 WC Biochemistry & Molecular Biology; Microbiology SC Biochemistry & Molecular Biology; Microbiology GA ZC100 UT WOS:000072539900010 ER PT J AU Warren, OL Graham, JF Norton, PR Houston, JE Michalske, TA AF Warren, O. L. Graham, J. F. Norton, P. R. Houston, J. E. Michalske, T. A. TI Nanomechanical properties of films derived from zinc dialkyldithiophosphate SO TRIBOLOGY LETTERS LA English DT Article DE zinc dialkyldithiophosphate; boundary lubrication; wear; interfacial force microscopy; nanoindentation AB We have applied scanning force microscopes to the problem of determining the nanomechanical properties and topography of films derived from the antioxidant/antiwear oil additive zinc dialkyldithiophosphate (ZDDP). The enhanced capabilities of the interfacial force microscope (IFM) are exploited to obtain quantitative force-displacement data and pre- and post-indent images, and the atomic force microscope (AFM) enables us to survey topography up to much larger spatial dimensions. A film which has been generated by static immersion of a steel coupon in heated ZDDP/oil solution displays a nanoindentation response similar to that of lightly loaded regions of a film which has been prepared by conventional wear testing using the same starting materials. More interestingly, highly loaded regions of the same wear specimen exhibit a much different nanomechanical response, which signals the presence of at least two different film materials. The film material in highly loaded regions displays an amazing capacity to deform in a predominantly elastic mode, which is in sharp contrast with the elastic-plastic properties of lightly loaded regions, and of the film generated by static immersion. Our results are not inconsistent with the possibility of friction-induced glass as a proper description for highly loaded regions of the wear specimen. C1 [Warren, O. L.; Graham, J. F.; Norton, P. R.] Univ Western Ontario, Dept Chem, London, ON N6A 5B7, Canada. [Houston, J. E.; Michalske, T. A.] Sandia Natl Labs, Surface & Interface Sci Dept, Albuquerque, NM 87185 USA. RP Warren, OL (reprint author), Univ Western Ontario, Dept Chem, London, ON N6A 5B7, Canada. FU Natural Sciences and Engineering Research Council of Canada; Ontario Centre for Materials Research; US Department of Energy [AC04-94AL85000] FX We thank C.R. Ribaudo and The Timken Co. for characterizing the steel coupons, K.F. Fyfe and Imperial Oil (Esso) of Canada for preparing the antiwear sample, M. Fuller for preparing the thermal sample, and C.A. DiRubio for assisting in the AFM work. We also appreciate the helpful discussions with members of the University of Western Ontario Tribology Research Centre, Exxon Corp., and Ford Motor Co. The University of Western Ontario component of this project was supported by the Natural Sciences and Engineering Research Council of Canada, and by the Ontario Centre for Materials Research. The Sandia portion of this work was supported by the US Department of Energy under Contract DE-AC04-94AL85000. NR 48 TC 66 Z9 66 U1 0 U2 7 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 MAR PY 1998 VL 4 IS 2 BP 189 EP 198 DI 10.1023/A:1019194903262 PG 10 WC Engineering, Chemical; Engineering, Mechanical SC Engineering GA V17SJ UT WOS:000207956600015 ER PT J AU Novotny, L Sanchez, EJ Xie, XS AF Novotny, L Sanchez, EJ Xie, XS TI Near-field optical imaging using metal tips illuminated by higher-order Hermite-Gaussian beams SO ULTRAMICROSCOPY LA English DT Article; Proceedings Paper CT 4th International Conference on Near-Field Optics and Related Techniques CY FEB 09-13, 1997 CL JERUSALEM, ISRAEL DE near-field optics; single molecule detection; fluorescence imaging; nonlinear optics; nanotechnology ID SINGLE MOLECULES; MICROSCOPY; SPECTROSCOPY; PROBE; SIZE AB We propose a new scheme for high-resolution near-field optical imaging. The method relies on the highly enhanced fields at sharp metal tips under laser illumination. These fields are laterally confined to the tip size and can be used to locally excite the sample surface. Illumination along the tip axis with a higher-order beam mode (Hermite-Gaussian(1,0) mode) and detection of nonlinear responses (two-photon fluorescence, generation of second/third harmonics) ensure sufficient background discrimination. We outline the theory of laser beams beyond the paraxial approximation and investigate the electromagnetic fields for the proposed scheme. (C) 1998 Elsevier Science B.V. All rights reserved. C1 Pacific NW Lab, Environm Mol Sci Lab, Richland, WA 99352 USA. RP Novotny, L (reprint author), Pacific NW Lab, Environm Mol Sci Lab, POB 999, Richland, WA 99352 USA. NR 24 TC 206 Z9 212 U1 2 U2 26 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0304-3991 J9 ULTRAMICROSCOPY JI Ultramicroscopy PD MAR PY 1998 VL 71 IS 1-4 BP 21 EP 29 DI 10.1016/S0304-3991(97)00077-6 PG 9 WC Microscopy SC Microscopy GA ZF289 UT WOS:000072882600004 ER PT J AU Madsen, S Holme, NCR Ramanujam, PS Hvilsted, S Hvam, JM Smith, SJ AF Madsen, S Holme, NCR Ramanujam, PS Hvilsted, S Hvam, JM Smith, SJ TI Optimizing the fabrication of aluminum-coated fiber probes and their application to optical near-field lithography SO ULTRAMICROSCOPY LA English DT Article; Proceedings Paper CT 4th International Conference on Near-Field Optics and Related Techniques CY FEB 09-13, 1997 CL JERUSALEM, ISRAEL DE fabrication of fiber probes; optical near-field lithography ID MICROSCOPY; REFLECTION; SPECTROSCOPY; SURFACE; SAMPLES AB We report on routine fabrication of fiber probes suitable for metal coating. We have investigated how aperture sizes ranging from 75 to 300 nm can be produced using an appropriate set of pulling parameters in a combined heating/pulling process. The quality of the metal coating has been investigated in terms of roughness and the presence of leaking holes in the coating. We report on how the quality of the coating depends on parameters such as deposition rate and background pressure during evaporation. We have used aluminum-coated fiber probes in lithographical studies of different materials, like side-chain azobenzene polyesters and hydrogen-passivated silicon surfaces displaying linewidths as narrow as 20 nm. (C) 1998 Published by Elsevier Science B.V. All rights reserved. C1 Danish Microengn AS, DME, DK-2730 Herlev, Denmark. Tech Univ Denmark, Mikroelekt Ctr, DK-2800 Lyngby, Denmark. Riso Natl Lab, DK-4000 Roskilde, Denmark. Natl Renewable Energy Lab, Golden, CO 80401 USA. RP Madsen, S (reprint author), Danish Microengn AS, DME, DK-2730 Herlev, Denmark. RI Hvam, Jorn/I-2987-2016 OI Hvam, Jorn/0000-0002-2429-1012 NR 19 TC 12 Z9 12 U1 0 U2 6 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0304-3991 J9 ULTRAMICROSCOPY JI Ultramicroscopy PD MAR PY 1998 VL 71 IS 1-4 BP 65 EP 71 DI 10.1016/S0304-3991(97)00095-8 PG 7 WC Microscopy SC Microscopy GA ZF289 UT WOS:000072882600009 ER PT J AU Smith, S Holme, NCR Orr, B Kopelman, R Norris, T AF Smith, S Holme, NCR Orr, B Kopelman, R Norris, T TI Ultrafast measurement in GaAs thin films using NSOM SO ULTRAMICROSCOPY LA English DT Article; Proceedings Paper CT 4th International Conference on Near-Field Optics and Related Techniques CY FEB 09-13, 1997 CL JERUSALEM, ISRAEL ID MICROSCOPY AB We combine near-field microscopy with ultrafast time-resolved spectroscopy, By combining these two techniques, local carrier cooling and relaxation processes can be measured with submicron spatial resolution, shedding light on their relationship to the microstructure in these materials. The first step in making these kinds of measurements is to characterize the measurement technique. NSOM measurements of differential transmission in GaAs thin films made using transmission mode NSOM combined with the equal pulse correlation (EPC) technique (first demonstrated by Tang and Erskine [C.L. Tang, D.J. Erskine, Phys. Rev. Lett. 51 (9) (1993)844]) are presented. These measurements show some features unique to the near-field: a high sensitivity to impurity concentrations(as low as 10(13) cm(-3)), a decrease in the depth of field as compared to a linear NSOM measurement, and a contribution due to carrier transport. These measurements show the potential for making spatially resolved femtosecond time-resolved measurements at surfaces of semiconductor bulk materials and devices. (C) 1998 Published by Elsevier Science B.V. All rights reserved. C1 Natl Renewable Energy Lab, Golden, CO 80401 USA. Univ Michigan, Ctr Ultrafast Opt Sci, Ann Arbor, MI 48109 USA. RP Smith, S (reprint author), Natl Renewable Energy Lab, 1617 Cole Blvd, Golden, CO 80401 USA. NR 12 TC 36 Z9 37 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0304-3991 J9 ULTRAMICROSCOPY JI Ultramicroscopy PD MAR PY 1998 VL 71 IS 1-4 BP 213 EP 223 DI 10.1016/S0304-3991(97)00062-4 PG 11 WC Microscopy SC Microscopy GA ZF289 UT WOS:000072882600029 ER PT J AU Enderle, T Ha, T Chemla, DS Weiss, S AF Enderle, T Ha, T Chemla, DS Weiss, S TI Near-field fluorescence microscopy of cells SO ULTRAMICROSCOPY LA English DT Article; Proceedings Paper CT 4th International Conference on Near-Field Optics and Related Techniques CY FEB 09-13, 1997 CL JERUSALEM, ISRAEL DE near-held optical microscopy; microscopic methods, specifically for biological specimens; spectroscopy in NFOM; green fluorescent protein; red-blood cells; malaria ID SCANNING OPTICAL MICROSCOPY; PROTEIN; FORCE AB We demonstrate the surface sensitivity of near-field scanning optical microscopy by fluorescence imaging of membrane and bulk proteins in cells. We discuss instrument design considerations for successful cell-biology work with NSOM and show that the technique is most suited for studying membrane proteins. (C) 1998 Published by Elsevier Science B.V. All rights reserved. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Mol Design Inst, Berkeley, CA 94720 USA. RP Weiss, S (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Mol Design Inst, Berkeley, CA 94720 USA. RI Ha, Taekjip/B-9506-2009; OI Ha, Taekjip/0000-0003-2195-6258; weiss, shimon/0000-0002-0720-5426 NR 18 TC 38 Z9 43 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0304-3991 J9 ULTRAMICROSCOPY JI Ultramicroscopy PD MAR PY 1998 VL 71 IS 1-4 BP 303 EP 309 DI 10.1016/S0304-3991(97)00075-2 PG 7 WC Microscopy SC Microscopy GA ZF289 UT WOS:000072882600042 PM 9566345 ER PT J AU Novotny, L Hecht, B Pohl, DW AF Novotny, L Hecht, B Pohl, DW TI Implications of high resolution to near-field optical microscopy SO ULTRAMICROSCOPY LA English DT Article; Proceedings Paper CT 4th International Conference on Near-Field Optics and Related Techniques CY FEB 09-13, 1997 CL JERUSALEM, ISRAEL DE near-field optics; scanning near-field optical microscopy; nanotechnology ID CONTRAST AB This paper presents problems inherent to high-resolution near-field optical microscopy. It is shown on an easily understandable level, that high lateral confinement of optical fields (a prerequisite for high-resolution microscopy) leads to a fast decay of the fields. Consequently, the optical probe has to be brought very close to the sample surface, increasing the sensitivity to artifacts. Highly confined optical fields are strongly sensitive to variations in the probe-sample separation. The resulting optical images are, therefore, dominated by topographical variations and do not represent the optical properties of the sample surface. (C) 1998 Published by Elsevier Science B.V. All rights reserved. C1 Pacific NW Natl Lab, Richland, WA 99352 USA. ETH Zurich, CH-8092 Zurich, Switzerland. IBM Corp, Div Res, Zurich Res Lab, CH-8803 Ruschlikon, Switzerland. RP Novotny, L (reprint author), Pacific NW Natl Lab, POB 999, Richland, WA 99352 USA. RI Hecht, Bert/B-4996-2010 OI Hecht, Bert/0000-0002-4883-8676 NR 6 TC 31 Z9 30 U1 0 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0304-3991 J9 ULTRAMICROSCOPY JI Ultramicroscopy PD MAR PY 1998 VL 71 IS 1-4 BP 341 EP 344 DI 10.1016/S0304-3991(97)00066-1 PG 4 WC Microscopy SC Microscopy GA ZF289 UT WOS:000072882600047 ER PT J AU Hsieh, HT Brown, GO Stone, ML Lucero, DA AF Hsieh, HT Brown, GO Stone, ML Lucero, DA TI Measurement of porous media component content and heterogeneity using gamma ray tomography SO WATER RESOURCES RESEARCH LA English DT Article ID COMPUTER-ASSISTED TOMOGRAPHY; SOIL BULK-DENSITY; WATER AB Tomographic images of porous media are complex distributions of linear attenuation coefficients that reflect the combined effects of scanning spatial resolution, photon statistical measurement errors, and true material densities. We address how the true voxel-scale attenuation distribution and measurement errors are convoluted to yield measured density frequency distributions. A deconvolution algorithm is demonstrated that uses the measured density frequency distributions and known photon statistical errors to quantify average cross-section volume contents of pure components and a mixed-component phase. The mixed-component phase represents regions where components are intertwined or varied in spaces smaller than the scanning resolution. This approach is applied to a complex core of the Culebra Dolomite Member of the Rustler Formation collected at the Waste Isolation Pilot Plant, near Carlsbad, New Mexico. The methodology provides a quantitative measure of the volume content of gypsum, dolomite, and mixed-components, and heterogeneity in the sample. C1 Oklahoma State Univ, Dept Agr & Biosyst Engn, Stillwater, OK 74078 USA. Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Hsieh, HT (reprint author), Oklahoma State Univ, Dept Agr & Biosyst Engn, 219 Agr Hall, Stillwater, OK 74078 USA. EM gbrown@agen.okstate.edu RI Brown, Glenn/H-4354-2012 NR 23 TC 11 Z9 11 U1 0 U2 1 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 MAR PY 1998 VL 34 IS 3 BP 365 EP 372 DI 10.1029/97WR02228 PG 8 WC Environmental Sciences; Limnology; Water Resources SC Environmental Sciences & Ecology; Marine & Freshwater Biology; Water Resources GA YZ627 UT WOS:000072273000005 ER PT J AU Zhang, DX AF Zhang, DX TI Numerical solutions to statistical moment equations of groundwater flow in nonstationary, bounded, heterogeneous media SO WATER RESOURCES RESEARCH LA English DT Article ID HEAD SPATIAL VARIABILITY; ANISOTROPIC POROUS-MEDIA; STEADY-STATE FLOW; STOCHASTIC-ANALYSIS; VELOCITY COVARIANCES; 3-DIMENSIONAL FLOW; HYDRAULIC CONDUCTIVITY; AQUIFERS; MACRODISPERSION; TRANSPORT AB In this pager we investigate the combined effect of nonstationarity in log hydraulic conductivity and the presence of boundaries on flow in heterogeneous aquifers. We derive general equations governing the statistical moments of hydraulic head for steady state flow by perturbation expansions. Due to their mathematical complexity, we solve the moment equations by the numerical technique of finite differences. The numerical approach has flexibility in handling (moderately) irregular geometry, different boundary conditions, various trends in the mean log hydraulic conductivity, spatial variabilities in the magnitude and direction of mean flow, and different covariance functions, all of which are important factors to consider for real-world applications. The effect of boundaries on the first two statistical moments involving head is strong and persistent. For example, in the case of stationary log hydraulic conductivity the head variance is always finite in a bounded domain while the head variance may be infinite in an unbounded domain. As in many other stochastic models, the statistical moment equations are derived under the assumption that the variance of log hydraulic conductivity is small. Accounting for a spatially varying, large-scale trend in the log hydraulic conductivity field reduces the variance of log hydraulic conductivity. Although this makes the conductivity field nonstationary and significantly increases the mathematical complexity in the problem, it justifies the small-variance assumption for many aquifers. 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,Mail Stop F665, Los Alamos, NM 87545 USA. RI Zhang, Dongxiao/D-5289-2009 OI Zhang, Dongxiao/0000-0001-6930-5994 NR 24 TC 57 Z9 61 U1 0 U2 3 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 MAR PY 1998 VL 34 IS 3 BP 529 EP 538 DI 10.1029/97WR03607 PG 10 WC Environmental Sciences; Limnology; Water Resources SC Environmental Sciences & Ecology; Marine & Freshwater Biology; Water Resources GA YZ627 UT WOS:000072273000020 ER PT J AU Nieves, RA Ehrman, CI Adney, WS Elander, RT Himmel, ME AF Nieves, RA Ehrman, CI Adney, WS Elander, RT Himmel, ME TI Survey and analysis of commercial cellulase preparations suitable for biomass conversion to ethanol SO WORLD JOURNAL OF MICROBIOLOGY & BIOTECHNOLOGY LA English DT Article DE cellobiase; cellulase; beta-glucosidase; industrial enzyme preparations ID TRICHODERMA AB Commercial cellulase enzymes have been used in the food, detergent, and textile industries, and are potentially effective for processing biomass feedstocks. A survey was undertaken to identify major manufacturers/distributors of cellulases in the USA and to evaluate 13 representative commercial preparations for enzyme activity, protein concentration, and chemical composition. Samples were subjected to activity measurements using filter paper, carboxymethylcellulose, cellobiose, and p-nitrophenyl-beta-D-glucopyranoside as substrates. To ascertain the microbial origin of the commercial preparations, Western blots utilizing monoclonal antibodies specific for Trichoderma reesei CBH I and Aspergillus niger beta-D-glucosidase were developed. Eleven of the cellulases tested were of T. reesei or T. viride origin and two were from A. niger. C1 Natl Renewable Energy Lab, Biotechnol Ctr Fuels & Chem, Golden, CO 80401 USA. RP Himmel, ME (reprint author), Natl Renewable Energy Lab, Biotechnol Ctr Fuels & Chem, Golden, CO 80401 USA. NR 6 TC 79 Z9 87 U1 0 U2 20 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0959-3993 J9 WORLD J MICROB BIOT JI World J. Microbiol. Biotechnol. PD MAR PY 1998 VL 14 IS 2 BP 301 EP 304 PG 4 WC Biotechnology & Applied Microbiology SC Biotechnology & Applied Microbiology GA ZB496 UT WOS:000072478400029 ER PT J AU Beck, HP Schramm, M Haberkorn, R Dinnebier, R Stephens, PW AF Beck, HP Schramm, M Haberkorn, R Dinnebier, R Stephens, PW TI Synthesis and crystal structure of Rb6Pb5Cl16 SO ZEITSCHRIFT FUR ANORGANISCHE UND ALLGEMEINE CHEMIE LA English DT Article DE ternary halide; lone pair cation; high coordination ID BINARY-SYSTEM INCL-SNCL2; PHASE-DIAGRAM; POWDER DIFFRACTION; AB2X5 COMPOUNDS; REDETERMINATION; REFINEMENT; PB; CL; BR AB The synthesis of a hitherto unknown 6:5 phase in the quasi-binary system RbCl/PbCl2 and its structure determination is reported. The compound Rb6Pb5Cl16 crystallizes in the tetragonal space group P4/mbm with a large variety of different coordination polyhedra for the cations. Special feature of the structure is a statistical distribution of Rb and Pb at one of the cation sites with a ratio of 1:3 as defined by electroneutrality. There is no evidence for symmetry reduction by ordering. C1 Univ Saarlandes, Fachrichtung Anorgan & Analyt Chem & Radiochem, D-66123 Saarbrucken, Germany. Univ Bayreuth, Inst Crystallog, Bayreuth, Germany. Brookhaven Natl Lab, Natl Synchrotron Light Source, Upton, NY 11973 USA. RP Beck, HP (reprint author), Univ Saarlandes, Fachrichtung Anorgan & Analyt Chem & Radiochem, D-66123 Saarbrucken, Germany. RI Dinnebier, Robert/B-5642-2015; OI Dinnebier, Robert/0000-0003-2778-2113; Haberkorn, Robert/0000-0002-4605-3760 NR 21 TC 5 Z9 5 U1 0 U2 1 PU WILEY-V C H VERLAG GMBH PI BERLIN PA MUHLENSTRASSE 33-34, D-13187 BERLIN, GERMANY SN 0044-2313 J9 Z ANORG ALLG CHEM JI Z. Anorg. Allg. Chem. PD MAR PY 1998 VL 624 IS 3 BP 393 EP 398 DI 10.1002/(SICI)1521-3749(199803)624:3<393::AID-ZAAC393>3.0.CO;2-V PG 6 WC Chemistry, Inorganic & Nuclear SC Chemistry GA ZB860 UT WOS:000072515300011 ER PT J AU Krstic, PS Reinhold, CO Schultz, DR AF Krstic, PS Reinhold, CO Schultz, DR TI Interference oscillations in the excitation cross section for slow ion-hydrogen collisions SO JOURNAL OF PHYSICS B-ATOMIC MOLECULAR AND OPTICAL PHYSICS LA English DT Letter ID ELECTRON-CAPTURE; INELASTIC PROCESSES; IONIZATION AB We have determined the minimum set of molecular states and couplings that can explain the origin of ubiquitous oscillations in the excitation cross section for low-energy ion-atom collisions which have recently drawn significant theoretical and experimental attention. To this end, the model of non-adiabatic radial couplings between quasimolecular states in slow heavy particle collisions is reformulated using the hidden-crossings theory to circumvent certain inherent shortcomings of the conventional molecular orbital close-coupling approach. We find that four diabatic states, two of which are formed by appropriate S superseries of branch points of the complex adiabatic quasimolecular energy surface, are required to represent the physical mechanism responsible for the oscillations. In particular, the oscillations originate from the interference of two paths along these terms through which the initial state is promoted to the same final quasimolecular state. C1 Oak Ridge Natl Lab, Div Phys, Oak Ridge, TN 37831 USA. RP Krstic, PS (reprint author), Oak Ridge Natl Lab, Div Phys, Oak Ridge, TN 37831 USA. OI Reinhold, Carlos/0000-0003-0100-4962 NR 30 TC 25 Z9 25 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 FEB 28 PY 1998 VL 31 IS 4 BP L155 EP L163 DI 10.1088/0953-4075/31/4/007 PG 9 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA ZA423 UT WOS:000072362000007 ER PT J AU Chambers, TK Fritz, JS AF Chambers, TK Fritz, JS TI Effect of polystyrene-divinylbenzene resin sulfonation on solute retention in high-performance liquid chromatography SO JOURNAL OF CHROMATOGRAPHY A LA English DT Article; Proceedings Paper CT 21st International Symposium on High Performance Liquid Phase Separations and Related Techniques CY JUN 22-27, 1997 CL BIRMINGHAM, ENGLAND DE stationary phases; LC; polystyrene-divinylbenzene resins; glycols; sugars; benzenes ID HYDROPHILIC-INTERACTION CHROMATOGRAPHY; POLAR COMPOUNDS; SEPARATION; EXCHANGE; ACIDS; OLIGOSACCHARIDES; PEPTIDES AB Polystyrene-divinylbenzene (PS-DVB) resins were sulfonated under different conditions to give a series of resins with sulfonic acid capacities ranging from 0.27 to 2.63 mmol/g. Each of the resins was packed into a conventional column and used for HPLC separation of various substituted benzenes using acetonitrile-water solutions as the mobile phase. In a mobile phase of acetonitrile-water (30:70), a nearly linear decrease in retention factor with increasing sulfonic acid capacity was noted for a set of substituted benzenes (polar and non-polar). The retention factors at the highest sulfonic acid capacity studied (2.63 mmol/g) were only 0.10 to 0.16 that of the unsulfonated resin. The sulfonated resins were also used for quasi-normal-phase separations of polar analytes such as glycols and sugars. In binary acetonitrile-water mobile phases, retention factors increased in a regular fashion as the concentration of acetonitrile was increased from 70 to 95%. Retention factors of the same analytes also increased substantially with increases in sulfonic acid content of the resin. (C) 1998 Elsevier Science B.V. C1 Iowa State Univ, US Dept Energy, Ames Lab, Dept Chem, Ames, IA 50011 USA. RP Fritz, JS (reprint author), Iowa State Univ, US Dept Energy, Ames Lab, Dept Chem, 332 Wilhelm Hall, Ames, IA 50011 USA. NR 28 TC 33 Z9 34 U1 0 U2 7 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 FEB 27 PY 1998 VL 797 IS 1-2 BP 139 EP 147 DI 10.1016/S0021-9673(97)01208-9 PG 9 WC Biochemical Research Methods; Chemistry, Analytical SC Biochemistry & Molecular Biology; Chemistry GA ZC852 UT WOS:000072625400016 ER PT J AU Biefeld, RM Allerman, AA Kurtz, SR AF Biefeld, RM Allerman, AA Kurtz, SR TI Recent advances in mid-infrared (3-6 mu m) emitters SO MATERIALS SCIENCE AND ENGINEERING B-SOLID STATE MATERIALS FOR ADVANCED TECHNOLOGY LA English DT Article; Proceedings Paper CT 2nd International Conference on Low Dimensional Structures and Devices CY MAY 19-21, 1997 CL LISBON, PORTUGAL DE InAsSb; mid-infrared laser; metal-organic chemical vapor deposition; infrared; light emitting diodes; antimonide materials ID CHEMICAL-VAPOR-DEPOSITION; CONTINUOUS-WAVE OPERATION; STRAINED-LAYER SUPERLATTICES; QUANTUM-WELLS; LASERS; INAS1-XSBX; TEMPERATURE; GROWTH; DIODES; ALLOYS AB We describe the metal-organic chemical vapor deposition (MOCVD) of InAsSb/InAs multiple quantum well (MQW) and InAsSb/InAsP strained-layer superlattice (SLS) active regions for use in mid-infrared emitters. We have made gain-guided, injection lasers using undoped, p-type AlAs0.16Sb0.84 for optical confinement and both strained InAsSb/InAs MQW and InAsSb/InAsP SLS active regions. The lasers and light emitting diodes (LED) utilize the semi-metal properties of a p-GaAsSb/nInAs heterojunction as a source for electrons injected into active regions. A multiple-stage LED utilizing this semi-metal injection scheme is reported. Gain-guided, injected lasers with a strained InAsSb/InAs MQW active region operated up to 210 K in pulsed mode with an emission wavelength of 3.8-3.9 mu m and a characteristic temperature of 29-40 K. We also present results for both optically pumped and injection lasers with InAsSb/InAsP SLS active regions. The maximum operating temperature of an optically pumped 3.7 mu m SLS laser was 240 K. An SLS LED emitted at 4.0 mu m with 80 mu W of power at 300 K. (C) 1998 Published by Elsevier Science S.A. All rights reserved. C1 Sandia Natl Labs, Dept 1113, Albuquerque, NM 87185 USA. RP Biefeld, RM (reprint author), Sandia Natl Labs, Dept 1113, POB 5800, Albuquerque, NM 87185 USA. NR 25 TC 20 Z9 20 U1 3 U2 10 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 FEB 27 PY 1998 VL 51 IS 1-3 BP 1 EP 8 DI 10.1016/S0921-5107(97)00218-3 PG 8 WC Materials Science, Multidisciplinary; Physics, Condensed Matter SC Materials Science; Physics GA ZD831 UT WOS:000072728800002 ER PT J AU Jackson, JD AF Jackson, JD TI The story of spin SO SCIENCE LA English DT Book Review C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Jackson, JD (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. NR 1 TC 0 Z9 0 U1 0 U2 0 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 FEB 27 PY 1998 VL 279 IS 5355 BP 1319 EP 1319 DI 10.1126/science.279.5355.1319 PG 1 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA YZ412 UT WOS:000072251800036 ER PT J AU Houk, RS AF Houk, RS TI Electrospray and ICP-mass spectrometry: enemies or allies? SO SPECTROCHIMICA ACTA PART B-ATOMIC SPECTROSCOPY LA English DT Article DE electrospray-MS; HPLC; inductively coupled plasma-MS; speciation ID INDUCTIVELY-COUPLED PLASMA; DIRECT-INJECTION NEBULIZATION; MUSCLE REFERENCE MATERIAL; ELEMENTAL SPECIATION; LIQUID-CHROMATOGRAPHY; CRYOGENIC DESOLVATION; TRACE-ELEMENTS; ION-SOURCE; RESOLUTION; ELECTROPHORESIS AB A case is made that either inductively coupled plasma-mass spectrometry or electrospray-mass spectrometry alone will not be adequate for the identification of unknown elemental species at trace levels in complex mixtures. These two types of ion source can be readily combined to provide both selective elemental analysis and molecular identification. The liquid flow rate regimes of these two measurement techniques are such that little compromise is expected if the two are used simultaneously on the same liquid chromatographic effluent. (C) 1998 Elsevier Science B.V. C1 Iowa State Univ, Dept Chem, US DOE, Ames Lab, Ames, IA 50011 USA. RP Houk, RS (reprint author), Iowa State Univ, Dept Chem, US DOE, Ames Lab, Ames, IA 50011 USA. NR 48 TC 16 Z9 16 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0584-8547 J9 SPECTROCHIM ACTA B JI Spectroc. Acta Pt. B-Atom. Spectr. PD FEB 27 PY 1998 VL 53 IS 2 BP 267 EP 271 DI 10.1016/S0584-8547(97)00147-X PG 5 WC Spectroscopy SC Spectroscopy GA ZW243 UT WOS:000074389900012 ER PT J AU Krauss, RM AF Krauss, RM TI Atherogenicity of triglyceride-rich lipoproteins SO AMERICAN JOURNAL OF CARDIOLOGY LA English DT Article; Proceedings Paper CT Symposium on the Role of Statins in Patients with Hypertriglyceridemia CY AUG 08-09, 1997 CL DALLAS, TEXAS SP Merck & Co Inc ID CORONARY-ARTERY DISEASE; INTERMEDIATE-DENSITY LIPOPROTEINS; RETINYL PALMITATE RESPONSES; MIDDLE-AGED MEN; POSTPRANDIAL TRIGLYCERIDE; PLASMA-LIPOPROTEINS; PROGRESSION; ATHEROSCLEROSIS; ASSOCIATION; RISK AB There is increasing evidence that alterations in metabolism of triglyceride-rich lipoproteins are of importance in the pathogenesis of atherosclerosis and its clinical consequences. particles with the characteristics of triglyceride-rich lipoprotein remnants have been related to the extent and severity of atherosclerosis in humans and in animal models. These particles can be identified using ultracentrifugal procedures as small, very low-density lipoprotein (VLDt) and intermediate-density lipoprotein (IDL) with Svedberg flotation rates (S-f) of 12-60. Postprandial triglyceride levels also have been related to risk of coronary artery disease, consistent with a pathologic role for remnant lipoproteins. In studies in which measurements of lipoprotein subfractions have been carried out, levels of IDL have been more predictive than low-density lipoprotein (LDL) of atherosclerosis progression as assessed by coronary artery angiography or carotid artery ultrasonography. These findings suggest that a considerable portion of the coronary disease risk attributed to LDL may be accounted for by the IDL particles included in standard LDL measurements. Other metabolic changes associated with increased levels of plasma triglyceride may also adversely affect cardiovascular disease risk. These include reductions in HDL-cholesterol and apoprotein A1, increased levels of small dense LDL particles, redistribution of apoC-III from HDL to apoB-containing lipoproteins, diminished insulin sensitivity, and procoagulant changes, including increased levels of the fibrinolyis inhibitor, plasminogen-activator inhibitor-1 (PAI-1). A predominance of small dense LDL (subclass pattern 8) is a discrete marker for this cluster of interrelated abnormalities and is found in 40-50% of patients with coronary artery disease. Therapeutic interventions with favorable effects on components of this dysmetabolic profile appear to be of value in decreasing atherosclerosis risk in a substantial proportion of the population. (C) 1998 by Excerpta Medica, Inc. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Donner Lab, Berkeley, CA 94720 USA. RP Krauss, RM (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Donner Lab, Room 465,1 Cyclotron Rd, Berkeley, CA 94720 USA. FU NHLBI NIH HHS [HL 18574] NR 35 TC 131 Z9 138 U1 0 U2 1 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 FEB 26 PY 1998 VL 81 IS 4A SI SI BP 13B EP 17B DI 10.1016/S0002-9149(98)00032-0 PG 5 WC Cardiac & Cardiovascular Systems SC Cardiovascular System & Cardiology GA ZA899 UT WOS:000072413200003 PM 9526808 ER PT J AU Parkhutik, VP Matveeva, E AF Parkhutik, VP Matveeva, E TI Effects of molecular doping by hydroquinones on morphology and optical properties of polyaniline SO JOURNAL OF PHYSICAL CHEMISTRY B LA English DT Article ID ELECTRICAL-PROPERTIES; POLYMERS; SOLVENTS; FILMS AB Thin films of the emeraldine base (EB) form of polyaniline containing different forms of hydroquinones (hydroquinone, HQ(1); tetrafluorohydroquinone, HQ(2); tetrahydroxy-1,4,-quinone, HQ(3)) were cast from the solutions of EB/HQ(1,2,3) in N-methylpyrrolidinone (NMP), Their properties were studied using optical micrography, UV-vis, and infrared absorption. It was found that hydroquinones act as molecular dopants of PANI by donating protons from their OH groups to the imine centers of the polymer and thus provoking a conversion of EB toward the emeraldine salt (ES). The extent of this conversion process is determined by the concentration of HQs and their ability to transform into the anion. Other important parameters are the temperature of drying and the time of storage of the liquid substance before casting, Because of the presence of at least two OH groups in HQ molecules, they can react with two or more imine centers of the polymer, thus bridging different polymer chains and provoking their ordering. Drying of the macroscopically ordered EB/HQ(1,2,3) liquid allows us to fix this ordering and to observe the nucleation and growth of spherulite crystals. Thus, HQ molecules play a double role in determining the structure and properties of emeraldine base. They, on one hand, produce protonation of the imine bonds of the polymer, similar to the mechanism of acid anion doping, and on the other hand, they operate as agents, causing the reorientation of conformational planes in polymeric chains and their mutual ordering. C1 Argonne Natl Lab, Argonne, IL 60439 USA. Univ Politecn Valencia, Dept Appl Thermodynam, Valencia 46071, Spain. RP Parkhutik, VP (reprint author), Argonne Natl Lab, MSD-223,S Cass Ave 9700, Argonne, IL 60439 USA. EM vitali@srsxr3.msd.anl.gov; vitali@ter.upv.es RI Matveeva, Eugenia/H-4676-2011 NR 32 TC 7 Z9 7 U1 1 U2 4 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 FEB 26 PY 1998 VL 102 IS 9 BP 1549 EP 1555 DI 10.1021/jp972471m PG 7 WC Chemistry, Physical SC Chemistry GA YZ899 UT WOS:000072305600009 ER PT J AU Laible, PD Knox, RS Owens, TG AF Laible, PD Knox, RS Owens, TG TI Detailed balance in Forster-Dexter excitation transfer and its application to photosynthesis SO JOURNAL OF PHYSICAL CHEMISTRY B LA English DT Article ID LIGHT-HARVESTING ANTENNA; ULTRAFAST ENERGY-TRANSFER; EXCITON MIGRATION; PHOTOSYSTEM-II; RHODOBACTER-SPHAEROIDES; CHARGE SEPARATION; ELECTRON-TRANSFER; EMISSION-SPECTRA; MOLECULAR PAIRS; CORE ANTENNA AB Under the conditions assumed both by Forster in his resonance-transfer theory and by Kennard and Stepanov in their theory of a universal relation between fluorescence and absorption, the rates of transfer between two chromophores k and l are related by Fl-k/Fk-l = exp[-(Delta G(k) - Delta G(l))/k(B)T)], where the energies Delta G(j) are the free energies of excitation relating to the vibrational and other bath states interacting with the chromophore. They are dominated by, but not identical with, the 0-0 transition energies of the two chromophores. We show that Delta G(k) - Delta G(l) can be computed reliably with Forster's overlap integral approximation only when the Kennard-Stepanov relation is obeyed for both chromophores. We examine the extent to which approximations to Forster-Dexter transfer agree with this detailed balance result and the implications of the result for multichromophore systems. C1 Cornell Univ, Plant Biol Sect, Ithaca, NY 14853 USA. Univ Rochester, Dept Phys & Astron, Rochester, NY 14627 USA. Univ Rochester, Rochester Theory Ctr Opt Sci & Engn, Rochester, NY 14627 USA. RP Laible, PD (reprint author), Argonne Natl Lab, Div Chem, 9700 S Cass Ave, Argonne, IL 60439 USA. NR 70 TC 32 Z9 32 U1 0 U2 12 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 FEB 26 PY 1998 VL 102 IS 9 BP 1641 EP 1648 DI 10.1021/jp9730104 PG 8 WC Chemistry, Physical SC Chemistry GA YZ899 UT WOS:000072305600022 ER PT J AU Maris, P Roberts, CD Tandy, PC AF Maris, P Roberts, CD Tandy, PC TI Pion mass and decay constant SO PHYSICS LETTERS B LA English DT Article DE goldstone bosons; dynamical chiral symmetry breaking; Dyson-Schwinger equations; nonperturbative QCD ID NON-PERTURBATIVE CALCULATION; CHIRAL-SYMMETRY BREAKING; GAUGE GLUON PROPAGATOR; GOLDSTONES THEOREM; INFRARED LIMIT; CONFINEMENT; EQUATIONS; DYSON; MODEL AB Independent of assumptions about the form of the quark-antiquark scattering kernel we derive the explicit relation between the pion Bethe-Salpeter amplitude, Gamma(pi), and the quark propagator in the chiral limit; Gamma(pi), necessarily involves a non-negligible gamma(5) gamma.P term (P is the pion four-momentum). We also obtain exact expressions for the pion decay constant, f(pi), and mass, both of which depend on Gamma(pi); and demonstrate the equivalence between f(pi) and the pion Bethe-Salpeter normalisation constant in the chiral limit. We stress the importance of preserving the axial-vector Ward-Takahashi identity in any study of the pion itself, and in any study whose goal is a unified understanding of the properties of the pion and other hadronic bound states. (C) 1998 Published by Elsevier Science B.V. C1 Argonne Natl Lab, Div Phys, Argonne, IL 60439 USA. Kent State Univ, Dept Phys, Nucl Res Ctr, Kent, OH 44242 USA. RP Maris, P (reprint author), Argonne Natl Lab, Div Phys, Bldg 203, Argonne, IL 60439 USA. OI Roberts, Craig/0000-0002-2937-1361 NR 23 TC 317 Z9 319 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0370-2693 J9 PHYS LETT B JI Phys. Lett. B PD FEB 26 PY 1998 VL 420 IS 3-4 BP 267 EP 273 DI 10.1016/S0370-2693(97)01535-9 PG 7 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA ZH149 UT WOS:000073077700005 ER PT J AU Anthony, TR Alvarenga, AD Grimsditch, M Kim, H Ramdas, AK Rodriguez, S Vogelgesang, R AF Anthony, TR Alvarenga, AD Grimsditch, M Kim, H Ramdas, AK Rodriguez, S Vogelgesang, R TI Vibrational and electronic excitations in isotopically controlled diamonds SO CURRENT SCIENCE LA English DT Article ID SEMICONDUCTORS AB Lattice vibrations of isotopically controlled single crystals of diamond (C-12(1-x) C-13(x), 0 less than or equal to x less than or equal to 1) are investigated with Raman, Brillouin, and Fourier transform infrared spectroscopy. The variation of the zone center optical phonon frequency and elastic moduli in the context of the virtual crystal approximation and zero-point motion; critical point frequencies as manifested in the two-phonon Raman and infrared spectra are addressed in these studies. The electronic infrared and Raman spectra of holes bound to substitutional boron accepters in isotopically controlled diamonds show: (1) the Lyman transitions in which the bound states manifest host-related-self-energy shifts; (2) the spin-orbit splitting (Delta') of the 1s ground state into 1s(p(3/2)) and 1s(p(1/2)), 1s(p(1/2)) being thermally populated; (3) a direct observation of the 1s(p(3/2)) --> 1s(p(1/2)) transition as an electronic Raman at Delta', together with its isotopic effects. C1 GE, Corp Res & Dev, Schenectady, NY 12309 USA. Purdue Univ, Dept Phys, W Lafayette, IN 47907 USA. Argonne Natl Lab, Argonne, IL 60439 USA. RP Anthony, TR (reprint author), GE, Corp Res & Dev, POB 8, Schenectady, NY 12309 USA. RI Vogelgesang, Ralf/B-4460-2009; Alvarenga, Ana Paula/M-9790-2014 OI Vogelgesang, Ralf/0000-0002-1026-3205; NR 23 TC 0 Z9 0 U1 0 U2 0 PU CURRENT SCIENCE ASSN PI BANGALORE PA C V RAMAN AVENUE, PO BOX 8005, BANGALORE 560 080, INDIA SN 0011-3891 J9 CURR SCI INDIA JI Curr. Sci. PD FEB 25 PY 1998 VL 74 IS 4 BP 317 EP 321 PG 5 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA ZC722 UT WOS:000072610000013 ER PT J AU Dreeben, TD Pope, SB AF Dreeben, TD Pope, SB TI Probability density function Monte Carlo simulation of near-wall turbulent flows SO JOURNAL OF FLUID MECHANICS LA English DT Article ID REYNOLDS-STRESS; FUNCTION MODEL; CHANNEL FLOW; PDF METHODS; CLOSURE AB Probability density function (p.d.f.) methods are extended to include modelling of wall-bounded turbulent flows. A p.d.f near-wall model is developed in which the generalized Langevin model is combined with a model for viscous transport. This provides exact treatment of viscous inhomogeneous effects, and enables consistent imposition of the no-slip condition in a particle framework. The method of elliptic relaxation is combined with additional boundary conditions and with the generalized Langevin model to provide an analogy for the near-wall fluctuating continuity equation. This provides adequate representation of the near-wall anisotropy of the Reynolds stresses. The model is implemented with a p.d.f./Monte Carlo simulation for the joint p.d.f. of velocity and turbulent frequency. Results are compared with DNS and experimental profiles for fully developed turbulent channel flow. C1 Cornell Univ, Dept Mech & Aerosp Engn, Ithaca, NY 14853 USA. RP Dreeben, TD (reprint author), Sandia Natl Labs, Combust Res Facil, Livermore, CA 94551 USA. RI Pope, Stephen/F-6268-2011 OI Pope, Stephen/0000-0001-5629-0420 NR 56 TC 40 Z9 40 U1 0 U2 2 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 FEB 25 PY 1998 VL 357 BP 141 EP 166 DI 10.1017/S0022112097008008 PG 26 WC Mechanics; Physics, Fluids & Plasmas SC Mechanics; Physics GA ZD994 UT WOS:000072746400007 ER PT J AU Collman, JP Harford, ST Franzen, S Eberspacher, TA Shoemaker, RK Woodruff, WH AF Collman, JP Harford, ST Franzen, S Eberspacher, TA Shoemaker, RK Woodruff, WH TI Spectroscopic comparisons of MoW(porphyrin)(2) heterodimers with homologous Mo-2 and W-2 quadruple bonds: A dynamic NMR and resonance Raman study SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Article ID RUTHENIUM PORPHYRIN DIMERS; METAL-METAL BONDS; STRUCTURAL CHARACTERIZATION; PHOTOELECTRON-SPECTROSCOPY; ELECTRONIC-STRUCTURES; ROTATIONAL BARRIER; P-31(H-1) NMR; COMPLEXES; MOLYBDENUM; TUNGSTEN AB The rotational barrier for MoW(meso-monotolyl octaethylporphyrin)(2) ([(TOEP)MoW(TOEP)]) has been determined (Delta G(rot)double dagger = 10.6 +/- 0.1 kcal/mol) by variable-temperature NMR and complete band shape analysis and is compared with values previously obtained for the analogous homodimers. The overall quadruple bond strengths of these isostructural dimolybdenum, ditungsten, and molybdenum-tungsten porphyrin dimers have also been compared by calculation of the force constants corresponding to each metal-metal bond stretching frequency as observed by resonance Raman spectroscopy. The Raman results are as follows: [Mo(OEP)](2), nu(MoMo) = 310 cm(-1), k = 2.72 mdyn/Angstrom; [(OEP)MoW(OEP)], nu(MoW) = 279 cm(-1), k = 2.89 mdyn/Angstrom; [Mo(TOEP)](2), nu(MoMo) = 310 cm(-1), k = 2.72 nu(MoMo) [W(TOEP)](2), nu(WW) = 275 cm(-1), k = 4.08 mdyn/Angstrom; and [(TOEP)MoW(TOEP)], nu(MoW) = 278 cm-1, k = 2.87 mdyn/Angstrom. Both the H-1 NMR and Raman specta are consistent with a [(Por)MoW(Por)] structure wherein the Mo(Por) congener experiences a more drastic "bending-back" distortion of the porphyrin macrocycle. C1 Stanford Univ, Dept Chem, Stanford, CA 94305 USA. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Univ Nebraska, Lincoln, NE 68588 USA. RP Collman, JP (reprint author), Stanford Univ, Dept Chem, Stanford, CA 94305 USA. RI Shoemaker, Richard/M-7409-2013 OI Shoemaker, Richard/0000-0002-0805-1449 NR 44 TC 18 Z9 18 U1 0 U2 7 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 FEB 25 PY 1998 VL 120 IS 7 BP 1456 EP 1465 DI 10.1021/ja972130m PG 10 WC Chemistry, Multidisciplinary SC Chemistry GA YZ359 UT WOS:000072246500016 ER PT J AU Majewski, J Kuhl, TL Kjaer, K Gerstenberg, MC Als-Nielsen, J Israelachvili, JN Smith, GS AF Majewski, J Kuhl, TL Kjaer, K Gerstenberg, MC Als-Nielsen, J Israelachvili, JN Smith, GS TI X-ray synchrotron study of packing and protrusions of polymer-lipid monolayers at the air-water interface SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Article ID GRAZING-INCIDENCE DIFFRACTION; NEUTRON REFLECTION; HYDRATION FORCES; SURFACES; BILAYERS; MODULATION; FLUID AB Using X-ray scattering, the structure of compressed phospholipid monolayers at the air-water interface matrixed with varying amounts of polymer lipid has been determined. The out-of-plane structure of the monolayer was greatly perturbed by the incorporation of the bulky polymer lipid resulting in a systematic roughening of the interface and a decrease in the coherently Bragg-scattering lipid tail region. Our results indicate that the increased lateral packing stresses due to the hydrophilic polymer chains are predominately relaxed through an increase in lipid protrusions rather than an increased area per lipid molecule. C1 Los Alamos Natl Lab, Manuel Lujan Jr Neutron Scattering Ctr, Los Alamos, NM 87545 USA. Riso Natl Lab, Dept Solid State Phys, DK-4000 Roskilde, Denmark. Univ Copenhagen, Niels Bohr Inst, HC Orsted Lab, DK-2100 Copenhagen, Denmark. Univ Calif Santa Barbara, Mat Res Lab, Santa Barbara, CA 93106 USA. RP Smith, GS (reprint author), Los Alamos Natl Lab, Manuel Lujan Jr Neutron Scattering Ctr, Los Alamos, NM 87545 USA. RI Lujan Center, LANL/G-4896-2012 NR 29 TC 41 Z9 41 U1 0 U2 8 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 FEB 25 PY 1998 VL 120 IS 7 BP 1469 EP 1473 DI 10.1021/ja973024n PG 5 WC Chemistry, Multidisciplinary SC Chemistry GA YZ359 UT WOS:000072246500018 ER PT J AU Tallarek, U Bayer, E Guiochon, G AF Tallarek, U Bayer, E Guiochon, G TI Study of dispersion in packed chromatographic columns by pulsed field gradient nuclear magnetic resonance SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Article ID PERFORMANCE LIQUID-CHROMATOGRAPHY; TO-VOLUME RATIO; POROUS-MEDIA; DIFFUSION-COEFFICIENT; RADIAL HOMOGENEITY; SURFACE RELAXATION; AXIAL-DISPERSION; STIMULATED-ECHO; PGSE NMR; TRANSPORT AB Pulsed field gradient nuclear magnetic resonance (PFGNMR) allows the direct determination of the average value of the axial and transverse apparent dispersion coefficient in a packed bed over a certain volume of this bed. From these data, the dependence of the local value of the height equivalent to a theoretical plate (HETP) of a chromatographic column on the fluid velocity can be measured accurately. The results are shown to be exactly accounted for by the Giddings equation. The PFGNMR measurements are made over a very short period of time. Hence they give the value of the HETP averaged over a limited volume of packing and a short time. This value is markedly smaller than the one afforded by the classical methods of chromatography and which is derived from the width of the distribution of the residence time of a small sample. The difference is explained by systematic variations of the local mobile-phase velocity across the column. PFGNMR techniques also allow the determination of the tortuosity of the column packing in the absence of flow. Their results confirm that the apparent dispersion experienced by a molecule is a function of the duration of the observation, until the tortuosity of the packing is completely felt. The values obtained agree very well with those derived from classical chromatography determinations. C1 Univ Tennessee, Dept Chem, Knoxville, TN 37996 USA. Univ Tubingen, Inst Organ Chem, D-72076 Tubingen, Germany. Oak Ridge Natl Lab, Div Analyt Chem, Oak Ridge, TN 37831 USA. RP Guiochon, G (reprint author), Univ Tennessee, Dept Chem, Knoxville, TN 37996 USA. NR 83 TC 84 Z9 84 U1 0 U2 9 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 FEB 25 PY 1998 VL 120 IS 7 BP 1494 EP 1505 DI 10.1021/ja9726623 PG 12 WC Chemistry, Multidisciplinary SC Chemistry GA YZ359 UT WOS:000072246500023 ER PT J AU Miksovska, J Valerio-Lepiniec, M Schiffer, M Hanson, DK Sebban, P AF Miksovska, J Valerio-Lepiniec, M Schiffer, M Hanson, DK Sebban, P TI In bacterial reaction centers, a key residue suppresses mutational blockage of two different proton transfer steps SO BIOCHEMISTRY LA English DT Article ID PHOTOSYNTHETIC REACTION-CENTER; ACCEPTOR QUINONE COMPLEX; RHODOBACTER-SPHAEROIDES; RHODOPSEUDOMONAS-VIRIDIS; SECONDARY QUINONE; 2ND-SITE MUTATION; ELECTRON-TRANSFER; BINDING-SITE; PROTEIN; PATHWAY AB In reaction centers of Rhodobacter (Rb.) capsulatus, the M43Asn -->Asp substitution is capable of restoring rapid rates for delivery of the second proton to Q(B) in a mutant that lacks L212Glu, Flash-induced absorbance spectroscopy was used to show a nearly native rate for transfer of the second proton to Q(B) (congruent to 700 s(-1)) in the L212Gln+M43Asp double-mutant reaction center; this rate was shown to decrease more than 1000-fold in the photoincompetent L212Glu -->Gln mutant [Miksovska, J., Kalman, L., Maroti, P., Schiffer, M., Set,ban, P., and Hanson, D. K, (1997) Biochemistry 36, 12216-12226]. In Rb, sphaeroides, the equivalent M44Asn -->Asp mutation was reported to restore the rate of transfer of the first proton to a wild-type level when it is added to the L213Asp -->Asn photoincompetent mutant [Rongey, S. H., Paddock, M. L., Feher, G., and Okamura, M. Y. (1993) Proc, Natl. Acad. Sci. U.S.A. 90, 1325-1329]. It is remarkable that the same second-site mutation can compensate for both of these mutations which severely impair reaction center function by blocking two different proton-transfer reactions. We suggest that residue M43Asp is situated in a key position which can link pathways for delivery of both the first and second protons; (involving structured water molecules) to Q(B). C1 CNRS, Ctr Mol Genet, F-91440 Gif Sur Yvette, France. Argonne Natl Lab, Ctr Mechanist Biol & Biotechnol, Argonne, IL 60439 USA. RP Miksovska, J (reprint author), CNRS, Ctr Mol Genet, Bat 24, F-91440 Gif Sur Yvette, France. NR 35 TC 13 Z9 13 U1 0 U2 4 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0006-2960 J9 BIOCHEMISTRY-US JI Biochemistry PD FEB 24 PY 1998 VL 37 IS 8 BP 2077 EP 2083 DI 10.1021/bi972696n PG 7 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA YZ846 UT WOS:000072299900001 PM 9518006 ER PT J AU Hodis, HN Krauss, RM AF Hodis, HN Krauss, RM TI Intermediate lipoproteins, atherosclerosis, and Gofman - Response SO CIRCULATION LA English DT Letter C1 Univ So Calif, Sch Med, Atherosclerosis Res Unit, Los Angeles, CA 90089 USA. Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Dept Mol & Nucl Med, Berkeley, CA 94720 USA. RP Hodis, HN (reprint author), Univ So Calif, Sch Med, Atherosclerosis Res Unit, Los Angeles, CA 90089 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU LIPPINCOTT WILLIAMS & WILKINS PI PHILADELPHIA PA 227 EAST WASHINGTON SQ, PHILADELPHIA, PA 19106 USA SN 0009-7322 J9 CIRCULATION JI Circulation PD FEB 24 PY 1998 VL 97 IS 7 BP 708 EP 708 PG 1 WC Cardiac & Cardiovascular Systems; Peripheral Vascular Disease SC Cardiovascular System & Cardiology GA YX717 UT WOS:000072070200021 ER PT J AU Gracias, DH Somorjai, GA AF Gracias, DH Somorjai, GA TI Continuum force microscopy study of the elastic modulus, hardness and friction of polyethylene and polypropylene surfaces SO MACROMOLECULES LA English DT Article ID MECHANICAL-PROPERTIES; FILMS; ADHESION; PRESSURE; POLYMERS; CONTACT AB The atomic force microscope (AFM) has been modified to a continuum force microscope (CFM) by using a tip of a large radius of curvature (1000 nm), in an attempt to reduce the pressure in the contact region. The elastic modulus, hardness, and friction of the surfaces of low density polyethylene, high density polyethylene, isotactic polypropylene, and atactic polypropylene have been quantitatively measured at low loads (10(-8)-10(-6) N) with the CFM. The effect of pressure applied by the tip has been observed in the measurements, resulting in an increase in the elastic modulus and the shear strength of the polymer surface with increasing pressure. The effect of pressure increases with decreasing density of the polymer. The higher values of elastic modulus and hardness of the polymer surface correlate well with the higher crystallinity of the polymers. Frictional properties of the polymers show characteristics that can be explained by the JKR model; the relative frictional behavior of the polyolefin surfaces however is controlled by the deformation component of the friction, i.e., the yield strength, the elastic modulus and the pressure dependence of the shear strength. C1 Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. 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. RI Gracias, David/A-1942-2010 OI Gracias, David/0000-0003-2735-4725 NR 48 TC 74 Z9 74 U1 3 U2 23 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0024-9297 J9 MACROMOLECULES JI Macromolecules PD FEB 24 PY 1998 VL 31 IS 4 BP 1269 EP 1276 DI 10.1021/ma970683b PG 8 WC Polymer Science SC Polymer Science GA YZ347 UT WOS:000072245300044 ER PT J AU Lugmair, CG Tilley, TD AF Lugmair, CG Tilley, TD TI Hydrolysis of zirconium and hafnium siloxide complexes. Isolation and characterization of the intermediate aqua complexes M[OSi((OBu)-Bu-t)(3)](4)(H2O)(n) (M = Zr, Hf; n = 1, 2) SO INORGANIC CHEMISTRY LA English DT Article ID ALKOXIDE PRECURSORS; METAL OXIDES; GEL; TRANSITION; CHEMISTRY; AEROGELS AB Hydrolysis of the tris(tert-butoxy)siloxy complexes M[OSi((OBu)-Bu-t)(3)](4) (1,M = Zr; 2, M = Hf) was studied. Careful addition of 1 or 2 equiv of water to THF solutions of 1 and 2 produced the isolable aqua complexes M[OSi((OBu)-Bu-t)(3)](4)(H2O) (3, M = Zr; 4, M = Hf) and M[OSi((OBu)-Bu-t)(3)](4)(H2O)(2) (5, M = Zr; 6, M = Hf)., These complexes are stable for weeks in solution and are stable indefinitely in the solid state, In solution, the aqua ligands in 3-6 are labile. Crystals of 4 are monoclinic (C2/c) With a = 62.2352(4) Angstrom, b = 13.3362(2) Angstrom, c = 27.0940(4) Angstrom, beta = 103.535(1)degrees, V = 21836.0(4) Angstrom(3), and Z = 4. Addition of excess water to solutions of 5 and 6 at room temperature results in rapid hydrolysis to form a MOx(OH)(y)(OH2)(z) gel and HOSi((OBu)-Bu-t)(3). Below 10 degrees C in tetrahydrofuran-d(8), however, hydrolysis does not occur at an appreciable rate. At low temperatures, the rate of exchange between the aqua ligands of 5 and excess free water was found to depend on the water concentration This indicates that the aqua ligand exchange occurs by an associative mechanism involving a seven-coordinate intermediate. On the basis of this observation, we postulate that the hydrolysis of 5 also proceeds via the tris(aqua) intermediate Zr[OSi((OBu)-Bu-t)(3)](4)(H2O)(3). Compounds 3-6 are more thermally stable than 1 and 2, indicating that the elimination of isobutene from the latter complexes is facilitated by a free coordination site on the Lewis acidic metal center. 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 41 TC 16 Z9 16 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 FEB 23 PY 1998 VL 37 IS 4 BP 764 EP 769 DI 10.1021/ic971211g PG 6 WC Chemistry, Inorganic & Nuclear SC Chemistry GA YZ549 UT WOS:000072265200026 ER PT J AU Kurmaev, EZ van Ek, J Ederer, DL Zhou, L Callcott, TA Perera, RCC Cherkashenko, VM Shamin, SN Trofimova, VA Bartkowski, S Neumann, M Fujimori, A Moloshag, VP AF Kurmaev, EZ van Ek, J Ederer, DL Zhou, L Callcott, TA Perera, RCC Cherkashenko, VM Shamin, SN Trofimova, VA Bartkowski, S Neumann, M Fujimori, A Moloshag, VP TI Experimental and theoretical investigation of the electronic structure of transition metal sulphides: CuS, FeS2 and FeCuS2 SO JOURNAL OF PHYSICS-CONDENSED MATTER LA English DT Article ID RAY-EMISSION-SPECTROSCOPY; SI K; EXCITATION; BAND AB Results of measurements of sulphur L-2,L-3 x-ray emission spectra of CuS and FeS2, excited by synchrotron radiation near the sulphur 2p threshold, are presented. An excitation energy dependence of the sulphur L-2,L-3 XES is only observed for CuS, and is attributed to the presence of inequivalent sulphur atoms in CuS. Two thirds of the sulphur atoms form S-2 dimers (as in FeS2) while the remaining ones are single (as in CuFeS2). This conclusion is confirmed by XPS measurements and LMTO band structure calculations for CuS, FeS2 and CuFeS2. It is shown that selective excitation of x-ray emission valence spectra can be used to determine the atom-decomposed partial density of states for inequivalent sites in solids, occupied by chemically identical species. C1 Russian Acad Sci, Inst Phys Met, Ural Div, Yekaterinburg 620219, Russia. Tulane Univ, Dept Phys, New Orleans, LA 70118 USA. Univ Tennessee, Dept Phys, Knoxville, TN 37996 USA. Lawrence Berkeley Lab, Berkeley, CA 94720 USA. Univ Osnabruck, Fachbereich Phys, D-49069 Osnabruck, Germany. Univ Tokyo, Dept Phys, Bunkyo Ku, Tokyo 113, Japan. Russian Acad Sci, Inst Geol & Geochem, Ural Div, Yekaterinburg 620151, Russia. RP Kurmaev, EZ (reprint author), Russian Acad Sci, Inst Phys Met, Ural Div, GSP-170, Yekaterinburg 620219, Russia. RI Kurmaev, Ernst/J-4254-2013; Shamin, Sergey/K-2922-2013 OI Kurmaev, Ernst/0000-0003-4625-4930; Shamin, Sergey/0000-0001-8213-5926 NR 25 TC 43 Z9 43 U1 3 U2 35 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 FEB 23 PY 1998 VL 10 IS 7 BP 1687 EP 1697 DI 10.1088/0953-8984/10/7/016 PG 11 WC Physics, Condensed Matter SC Physics GA YZ278 UT WOS:000072238100016 ER PT J AU Abbott, B Abolins, M Acharya, BS Adams, I Adams, DL Adams, M Ahn, S Aihara, H Alves, GA Amos, N Anderson, EW Astur, R Baarmand, MM Baden, A Balamurali, V Balderston, J Baldin, B Banerjee, S Bantly, J Barberis, E Bartlett, JF Bazizi, K Belyaev, A Beri, SB Bertram, I Bezzubov, VA Bhat, PC Bhatnagar, V Bhattacharjee, M Biswas, N Blazey, G Blessing, S Bloom, P Boehnlein, A Bojko, NI Borcherding, F Boswell, C Brandt, A Brock, R Bross, A Buchholz, D Burtovoi, VS Butler, JM Carvalho, W Casey, D Casilum, Z Castilla-Valdez, H Chakraborty, D Chang, SM Chekulaev, SV Chen, LP Chen, W Choi, S Chopra, S Choudhary, BC Christenson, JH Chung, M Claes, D Clark, AR Cobau, WG Cochran, J Coney, L Cooper, WE Cretsinger, C Cullen-Vidal, D Cummings, MAC Cutts, D Dahl, OI Davis, K De, K Del Signore, K Demarteau, M Denisov, D Denisov, SP Diehl, HT Diesburg, M Di Loreto, G Draper, P Ducros, Y Dudko, LV Dugad, SR Edmunds, D Ellison, J Elvira, VD Engelmann, R Eno, S Eppley, G Ermolov, P Eroshin, OV Evdokimov, VN Fahland, T Fatyga, MK Feher, S Fein, D Ferbel, T Finocchiaro, G Fisk, HE Fisyak, Y Flattum, E Forden, GE Fortner, M Frame, KC Fuess, S Gallas, E Galyaev, AN Gartung, P Geld, TL Genik, RJ Genser, K Gerber, CE Gibbard, R Glenn, S Gobbi, B Goforth, M Goldschmidt, A Gomez, B Gomez, G Goncharov, PI Solis, JLG Gordon, H Goss, LT Gounder, K Goussiou, A Graf, N Grannis, PD Green, DR Greenlee, H Grim, G Grinstein, S Grossman, N Grudberg, P Grunendahl, S Guglielmo, G Guida, JA Guida, JM Gupta, A Gurzhiev, SN Gutierrez, P Gutnikov, YE Hadley, NJ Haggerty, H Hagopian, S Hagopian, V Hahn, KS Hall, RE Hanlet, P Hansen, S Hauptman, JM Hedin, D Heinson, AP Heintz, U Hernandez-Montoya, R Heuring, T Hirosky, R Hobbs, JD Hoeneisen, B Hoftun, JS Hsieh, F Hu, T Hu, T Huehn, T Ito, AS James, E Jaques, J Jerger, SA Jesik, R Jiang, JZY Joffe-Minor, T Johns, K Johnson, M Jonckheere, A Jones, M Jostlein, H Jun, SY Jung, CK Kahn, S Kalbfleisch, G Kang, JS Karmanov, D Karmgard, D Kehoe, R Kelly, ML Kim, CL Kim, SK Klatchko, A Klima, B Klopfenstein, C Klyukhin, VI Kochetkov, VI Kohli, JM Koltick, D Kostritskiy, AV Kotcher, J Kotwal, AV Kourlas, J Kozelov, AV Kozlovski, EA Krane, J Krishnaswamy, MR Krzywdzinski, S Kunori, S Lami, S Lander, R Landry, F Landsberg, G Lauer, B Leflat, A Li, H Li, J Li-Demarteau, QZ Lima, JGR Lincoln, D Linn, SL Linnemann, J Lipton, R Liu, YC Lobkowicz, F Loken, SC Lokos, S Lueking, L Lyon, AL Maciel, AKA Madaras, RJ Madden, R Magana-Mendoza, L Manankov, V Mani, S Mao, HS Markeloff, R Marshall, T Martin, MI Mauritz, KM May, B Mayorov, AA McCarthy, R McDonald, J McKibben, T McKinley, J McMahon, T Melanson, HL Merkin, M Merritt, KW Miettinen, H Mincer, A Mishra, CS Mokhov, N Mondal, NK Montgomery, HE Mooney, P da Motta, H Murphy, C Nang, F Narain, M Narasimham, VS Narayanan, A Neal, HA Negret, JP Nemethy, P Norman, D Oesch, L Oguri, V Oltman, E Oshima, N Owen, D Padley, P Para, A Park, YM Partridge, R Parua, N Paterno, M Pawlik, B Perkins, J Peters, M Piegaia, R Piekarz, H Pischalnikov, Y Podstavkov, VM Pope, BG Prosper, HB Protopopescu, S Qian, J Quintas, PZ Raja, R Rajagopalan, S Ramirez, O Rasmussen, L Reucroft, S Rijssenbeek, M Rockwell, T Roe, NA Rubinov, P Ruchti, R Rutherfoord, J Sanchez-Hernandez, A Santoro, A Sawyer, L Schamberger, RD Schellman, H Sculli, J Shabalina, E Shaffer, C Shankar, HC Shivpuri, RK Shupe, M Singh, H Singh, JB Sirotenko, V Smart, W Smith, E Smith, RP Snihur, R Snow, GR Snow, J Snyder, S Solomon, J Sood, PM Sosebee, M Sotnikova, N Souza, M Spadafora, AL Steinbrueck, G Stephens, RW Stevenson, ML Stewart, D Stichelbaut, F Stoianova, DA Stoker, D Strauss, M Streets, K Strovink, M Sznajder, A Tamburello, P Tarazi, J Tartaglia, M Thomas, TLT Thompson, J Trippe, TG Tuts, PM Varelas, N Varnes, EW Vititoe, D Volkov, AA Vorobiev, AP Wahl, HD Wang, G Warchol, J Watts, G Wayne, M Weerts, H White, A White, JT Wightman, JA Willis, S Wimpenny, SJ Wirjawan, JVD Womersley, J Won, E Wood, DR Xu, H Yamada, R Yamin, P Yang, J Yasuda, T Yepes, P Yoshikawa, C Youssef, S Yu, J Yu, Y Zhu, ZH Zieminska, D Zieminski, A Zverev, EG Zylberstejn, A AF Abbott, B Abolins, M Acharya, BS Adams, I Adams, DL Adams, M Ahn, S Aihara, H Alves, GA Amos, N Anderson, EW Astur, R Baarmand, MM Baden, A Balamurali, V Balderston, J Baldin, B Banerjee, S Bantly, J Barberis, E Bartlett, JF Bazizi, K Belyaev, A Beri, SB Bertram, I Bezzubov, VA Bhat, PC Bhatnagar, V Bhattacharjee, M Biswas, N Blazey, G Blessing, S Bloom, P Boehnlein, A Bojko, NI Borcherding, F Boswell, C Brandt, A Brock, R Bross, A Buchholz, D Burtovoi, VS Butler, JM Carvalho, W Casey, D Casilum, Z Castilla-Valdez, H Chakraborty, D Chang, SM Chekulaev, SV Chen, LP Chen, W Choi, S Chopra, S Choudhary, BC Christenson, JH Chung, M Claes, D Clark, AR Cobau, WG Cochran, J Coney, L Cooper, WE Cretsinger, C Cullen-Vidal, D Cummings, MAC Cutts, D Dahl, OI Davis, K De, K Del Signore, K Demarteau, M Denisov, D Denisov, SP Diehl, HT Diesburg, M Di Loreto, G Draper, P Ducros, Y Dudko, LV Dugad, SR Edmunds, D Ellison, J Elvira, VD Engelmann, R Eno, S Eppley, G Ermolov, P Eroshin, OV Evdokimov, VN Fahland, T Fatyga, MK Feher, S Fein, D Ferbel, T Finocchiaro, G Fisk, HE Fisyak, Y Flattum, E Forden, GE Fortner, M Frame, KC Fuess, S Gallas, E Galyaev, AN Gartung, P Geld, TL Genik, RJ Genser, K Gerber, CE Gibbard, R Glenn, S Gobbi, B Goforth, M Goldschmidt, A Gomez, B Gomez, G Goncharov, PI Solis, JLG Gordon, H Goss, LT Gounder, K Goussiou, A Graf, N Grannis, PD Green, DR Greenlee, H Grim, G Grinstein, S Grossman, N Grudberg, P Grunendahl, S Guglielmo, G Guida, JA Guida, JM Gupta, A Gurzhiev, SN Gutierrez, P Gutnikov, YE Hadley, NJ Haggerty, H Hagopian, S Hagopian, V Hahn, KS Hall, RE Hanlet, P Hansen, S Hauptman, JM Hedin, D Heinson, AP Heintz, U Hernandez-Montoya, R Heuring, T Hirosky, R Hobbs, JD Hoeneisen, B Hoftun, JS Hsieh, F Hu, T Hu, T Huehn, T Ito, AS James, E Jaques, J Jerger, SA Jesik, R Jiang, JZY Joffe-Minor, T Johns, K Johnson, M Jonckheere, A Jones, M Jostlein, H Jun, SY Jung, CK Kahn, S Kalbfleisch, G Kang, JS Karmanov, D Karmgard, D Kehoe, R Kelly, ML Kim, CL Kim, SK Klatchko, A Klima, B Klopfenstein, C Klyukhin, VI Kochetkov, VI Kohli, JM Koltick, D Kostritskiy, AV Kotcher, J Kotwal, AV Kourlas, J Kozelov, AV Kozlovski, EA Krane, J Krishnaswamy, MR Krzywdzinski, S Kunori, S Lami, S Lander, R Landry, F Landsberg, G Lauer, B Leflat, A Li, H Li, J Li-Demarteau, QZ Lima, JGR Lincoln, D Linn, SL Linnemann, J Lipton, R Liu, YC Lobkowicz, F Loken, SC Lokos, S Lueking, L Lyon, AL Maciel, AKA Madaras, RJ Madden, R Magana-Mendoza, L Manankov, V Mani, S Mao, HS Markeloff, R Marshall, T Martin, MI Mauritz, KM May, B Mayorov, AA McCarthy, R McDonald, J McKibben, T McKinley, J McMahon, T Melanson, HL Merkin, M Merritt, KW Miettinen, H Mincer, A Mishra, CS Mokhov, N Mondal, NK Montgomery, HE Mooney, P da Motta, H Murphy, C Nang, F Narain, M Narasimham, VS Narayanan, A Neal, HA Negret, JP Nemethy, P Norman, D Oesch, L Oguri, V Oltman, E Oshima, N Owen, D Padley, P Para, A Park, YM Partridge, R Parua, N Paterno, M Pawlik, B Perkins, J Peters, M Piegaia, R Piekarz, H Pischalnikov, Y Podstavkov, VM Pope, BG Prosper, HB Protopopescu, S Qian, J Quintas, PZ Raja, R Rajagopalan, S Ramirez, O Rasmussen, L Reucroft, S Rijssenbeek, M Rockwell, T Roe, NA Rubinov, P Ruchti, R Rutherfoord, J Sanchez-Hernandez, A Santoro, A Sawyer, L Schamberger, RD Schellman, H Sculli, J Shabalina, E Shaffer, C Shankar, HC Shivpuri, RK Shupe, M Singh, H Singh, JB Sirotenko, V Smart, W Smith, E Smith, RP Snihur, R Snow, GR Snow, J Snyder, S Solomon, J Sood, PM Sosebee, M Sotnikova, N Souza, M Spadafora, AL Steinbrueck, G Stephens, RW Stevenson, ML Stewart, D Stichelbaut, F Stoianova, DA Stoker, D Strauss, M Streets, K Strovink, M Sznajder, A Tamburello, P Tarazi, J Tartaglia, M Thomas, TLT Thompson, J Trippe, TG Tuts, PM Varelas, N Varnes, EW Vititoe, D Volkov, AA Vorobiev, AP Wahl, HD Wang, G Warchol, J Watts, G Wayne, M Weerts, H White, A White, JT Wightman, JA Willis, S Wimpenny, SJ Wirjawan, JVD Womersley, J Won, E Wood, DR Xu, H Yamada, R Yamin, P Yang, J Yasuda, T Yepes, P Yoshikawa, C Youssef, S Yu, J Yu, Y Zhu, ZH Zieminska, D Zieminski, A Zverev, EG Zylberstejn, A TI Search for trilepton signatures from associated gaugino pair production SO PHYSICAL REVIEW LETTERS LA English DT Article ID P(P)OVER-BAR COLLISIONS; PARTICLE PHYSICS; ROOT-S=1.8 TEV; SUPERSYMMETRY; NEUTRALINOS; CHARGINOS; FERMILAB AB We report on a search for the trilepton decay signature from the associated production of supersymmetric gaugino pairs, <(chi)over tilde>(+/-)(1)<(chi)over tilde>(0)(2), within the context of minimal supersymmetric models that conserve R parity. This search uses 95 pb(-1) of data taken at root(s) = 1.8 TeV with the D0 detector. No evidence of a trilepton signature has been found, and a limit on the product of cross section times branching fraction to trileptons is given as a function of <(chi)over tilde>(+/-)(1) mass. C1 NYU, New York, NY 10003 USA. Univ Los Andes, Bogota, Colombia. Univ Arizona, Tucson, AZ 85721 USA. Boston Univ, Boston, MA 02215 USA. Brookhaven Natl Lab, Upton, NY 11973 USA. Brown Univ, Providence, RI 02912 USA. Univ Buenos Aires, Buenos Aires, DF, Argentina. Univ Calif Davis, Davis, CA 95616 USA. Univ Calif Riverside, Riverside, CA 92521 USA. Univ Calif Irvine, Irvine, CA 92697 USA. Ctr Brasileiro Pesquisas Fis, LAFEX, Rio De Janeiro, Brazil. CINVESTAV, Mexico City 14000, DF, Mexico. Columbia Univ, New York, NY 10027 USA. Univ Delhi, Delhi 110007, India. Fermi Natl Accelerator Lab, Batavia, IL 60510 USA. Florida State Univ, Tallahassee, FL 32306 USA. Univ Hawaii, Honolulu, HI 96822 USA. Univ Illinois, Chicago, IL 60607 USA. Indiana Univ, Bloomington, IN 47405 USA. Iowa State Univ, Ames, IA 50011 USA. Korea Univ, Seoul 136701, South Korea. Kyungsung Univ, Pusan 608736, South Korea. Inst Phys Nucl, Krakow, Poland. Lawrence Berkeley Lab, Berkeley, CA USA. Univ Calif Berkeley, Berkeley, CA 94720 USA. Louisiana Tech Univ, Ruston, LA 71272 USA. Univ Maryland, College Pk, MD 20742 USA. Univ Michigan, Ann Arbor, MI 48109 USA. Michigan State Univ, E Lansing, MI 48824 USA. Moscow State Univ, Moscow, Russia. Univ Nebraska, Lincoln, NE 68588 USA. Northeastern Univ, Boston, MA 02115 USA. No Illinois Univ, De Kalb, IL 60115 USA. Northwestern Univ, Evanston, IL 60208 USA. Univ Oklahoma, Norman, OK 73019 USA. Punjab Univ, Chandigarh 160014, India. Inst High Energy Phys, Protvino 142284, Russia. Purdue Univ, W Lafayette, IN 47907 USA. Rice Univ, Houston, TX 77005 USA. Univ Estado do Rio de Janeiro, Rio De Janeiro, Brazil. Univ Rochester, Rochester, NY 14627 USA. Ctr Etud Saclay, CEA, DAPNIA, Serv Phys Particules, F-91191 Gif Sur Yvette, France. Seoul Natl Univ, Seoul, South Korea. SUNY Stony Brook, Stony Brook, NY 11794 USA. Tata Inst Fundamental Res, Mumbai 400005, India. Univ Texas, Arlington, TX 76019 USA. Texas A&M Univ, College Stn, TX 77843 USA. RP Abbott, B (reprint author), NYU, New York, NY 10003 USA. RI Belyaev, Alexander/F-6637-2015; Kim, Sun Kee/G-2042-2015; Chekulaev, Sergey/O-1145-2015; Sznajder, Andre/L-1621-2016; Alves, Gilvan/C-4007-2013; Santoro, Alberto/E-7932-2014; Peters, Michael/B-4973-2009; Aihara, Hiroaki/F-3854-2010; Shivpuri, R K/A-5848-2010; Gutierrez, Phillip/C-1161-2011; Dudko, Lev/D-7127-2012; Leflat, Alexander/D-7284-2012; Merkin, Mikhail/D-6809-2012; Klyukhin, Vyacheslav/D-6850-2012; De, Kaushik/N-1953-2013; Oguri, Vitor/B-5403-2013 OI Belyaev, Alexander/0000-0002-1733-4408; Kim, Sun Kee/0000-0002-0013-0775; Sznajder, Andre/0000-0001-6998-1108; Baarmand, Marc/0000-0002-9792-8619; Aihara, Hiroaki/0000-0002-1907-5964; Dudko, Lev/0000-0002-4462-3192; Klyukhin, Vyacheslav/0000-0002-8577-6531; De, Kaushik/0000-0002-5647-4489; NR 17 TC 27 Z9 27 U1 0 U2 2 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD FEB 23 PY 1998 VL 80 IS 8 BP 1591 EP 1596 DI 10.1103/PhysRevLett.80.1591 PG 6 WC Physics, Multidisciplinary SC Physics GA YY143 UT WOS:000072117600007 ER PT J AU Nagae, T Miyachi, T Fukuda, T Outa, H Tamagawa, T Nakano, J Hayano, RS Tamura, H Shimizu, Y Kubota, K Chrien, RE Sutter, R Rusek, A Briscoe, WJ Sawafta, R Hungerford, EV Empl, A Naing, W Neerman, C Johnston, K Planinic, M AF Nagae, T Miyachi, T Fukuda, T Outa, H Tamagawa, T Nakano, J Hayano, RS Tamura, H Shimizu, Y Kubota, K Chrien, RE Sutter, R Rusek, A Briscoe, WJ Sawafta, R Hungerford, EV Empl, A Naing, W Neerman, C Johnston, K Planinic, M TI Observation of a He-4(Sigma) bound state in the He-4(K-, pi(-)) reaction at 600 MeV/c SO PHYSICAL REVIEW LETTERS LA English DT Article ID SIGMA AB We have observed a clear peak below the Sigma(+)-production threshold in the He-4(K-, pi(-)) reaction at 600 MeV/c and theta(K pi) = 4 degrees. This is confirmation of the existence of the bound state of He-4(Sigma), which was reported in the He-4(stopped K-, pi(-)) reaction. As in the case of stopped kaons, no such peak was found in the He-4(K-, pi(+)) spectrum. Quantitatively reliable parameters for this level have been established. The binding energy and the width of the bound state are 4.4 +/- 0.3(stat) +/- 1(syst) MeV and 7.0 +/- 0.7(stat)(-0.0)(+1.2)(syst) MeV, respectively. C1 Univ Tokyo, Inst Nucl Study, Tokyo 188, Japan. Univ Tokyo, Tokyo 113, Japan. Brookhaven Natl Lab, Upton, NY 11973 USA. George Washington Univ, Brookhaven Natl Lab, Dept Phys, Washington, DC 20052 USA. George Washington Univ, Ctr Nucl Studies, Washington, DC 20052 USA. N Carolina Agr & Technol State Univ, Greensboro, NC 27411 USA. Univ Houston, Houston, TX 77204 USA. Hampton Univ, Hampton, VA 23668 USA. Louisiana Tech Univ, Dept Phys, Ruston, LA 71272 USA. Univ Zagreb, HR-10004 Zagreb, Croatia. RP Nagae, T (reprint author), KEK, 1-1 Oho, Ibaraki, Osaka 305, Japan. RI Planinic, Mirko/E-8085-2012; Hayano, Ryugo/F-7889-2012 OI Hayano, Ryugo/0000-0002-1214-7806 NR 19 TC 113 Z9 117 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 FEB 23 PY 1998 VL 80 IS 8 BP 1605 EP 1609 DI 10.1103/PhysRevLett.80.1605 PG 5 WC Physics, Multidisciplinary SC Physics GA YY143 UT WOS:000072117600010 ER PT J AU Bracker, AS Wouters, ER Suits, AG Lee, YT Vasyutinskii, OS AF Bracker, AS Wouters, ER Suits, AG Lee, YT Vasyutinskii, OS TI Observation of coherent and incoherent dissociation mechanisms in the angular distribution of atomic photofragment alignment SO PHYSICAL REVIEW LETTERS LA English DT Article ID PHOTODISSOCIATION; POLARIZATION; FRAGMENTS; MOLECULE; PROFILES AB We have analyzed the recoil angle dependence of chlorine atom angular momentum alignment for the dissociation of chlorine molecules at 355 nm. This angular distribution was isolated from ion image measurements, which map a three-dimensional velocity vector distribution of state-selectively-ionized photofragments into a two-dimensional spatial distribution. Using a general quantum mechanical method to simulate the alignment angular distribution, we show that there are clear contributions to alignment from both incoherent and coherent components of a perpendicular optical transition in the molecule. C1 Ernest Orlando Lawrence Berkeley Natl Lab, Div Chem Sci, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. Acad Sinica, Taipei 11529, Taiwan. AF Ioffe Phys Tech Inst, St Petersburg 194021, Russia. RP Vasyutinskii, OS (reprint author), Ernest Orlando Lawrence Berkeley Natl Lab, Div Chem Sci, Berkeley, CA 94720 USA. RI Lee, Yuan-Tseh/F-7914-2012 NR 20 TC 74 Z9 74 U1 2 U2 4 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD FEB 23 PY 1998 VL 80 IS 8 BP 1626 EP 1629 DI 10.1103/PhysRevLett.80.1626 PG 4 WC Physics, Multidisciplinary SC Physics GA YY143 UT WOS:000072117600015 ER PT J AU Dai, PC Mook, HA Dogan, F AF Dai, PC Mook, HA Dogan, F TI Incommensurate magnetic fluctuations in YBa2Cu3O6.6 SO PHYSICAL REVIEW LETTERS LA English DT Article ID HIGH-TEMPERATURE SUPERCONDUCTORS; NEUTRON-SCATTERING; LA2-XSRXCUO4; SUSCEPTIBILITY; SYSTEM; SPINS; HOLES AB We use inelastic neutron scattering to demonstrate that the low-frequency magnetic fluctuations in YBa2Cu3O6.6 (T-c = 62.7 K) change from commensurate to incommensurate on cooling with the incommensurability first appearing at temperatures above T-c. For the energies studied, the susceptibility at incommensurate positions increases on cooling below T-c, accompanied by a suppression of the spin fluctuations at the commensurate points. These results suggest that incommensurate spin fluctuations may be a common feature for all cuprate superconductors. C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. Univ Washington, Dept Mat Sci & Engn, Seattle, WA 98195 USA. RP Dai, PC (reprint author), Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RI Dai, Pengcheng /C-9171-2012 OI Dai, Pengcheng /0000-0002-6088-3170 NR 30 TC 211 Z9 211 U1 0 U2 8 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD FEB 23 PY 1998 VL 80 IS 8 BP 1738 EP 1741 DI 10.1103/PhysRevLett.80.1738 PG 4 WC Physics, Multidisciplinary SC Physics GA YY143 UT WOS:000072117600043 ER PT J AU Kawakami, RK Rotenberg, E Escorcia-Aparicio, EJ Choi, HJ Cummins, TR Tobin, JG Smith, NV Qiu, ZQ AF Kawakami, RK Rotenberg, E Escorcia-Aparicio, EJ Choi, HJ Cummins, TR Tobin, JG Smith, NV Qiu, ZQ TI Observation of the quantum well interference in magnetic nanostructures by photoemission SO PHYSICAL REVIEW LETTERS LA English DT Article ID GIANT MAGNETORESISTANCE; STATES; METAL; SUPERLATTICES; MULTILAYERS; OVERLAYERS; TRANSITION; SUBSTRATE; SYSTEMS; LAYERS AB The Ca/Co/Ni/Co(100) system was investigated by photoemission to study the interference between the Cu quantum well and the Ni layer. Bq varying their separation, we found that the density of states of the Cu quantum well states were biperiodically modulated. This result provides clear evidence for the quantum interference between two quantum wells in magnetic nanostructures. The biperiodicity was identified to correspond to the two Fermi vectors of the Co minority energy bands. C1 Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. Lawrence Berkeley Lab, Berkeley, CA 94720 USA. Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Kawakami, RK (reprint author), Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. RI Rotenberg, Eli/B-3700-2009; Tobin, James/O-6953-2015; Qiu, Zi Qiang/O-4421-2016 OI Rotenberg, Eli/0000-0002-3979-8844; Qiu, Zi Qiang/0000-0003-0680-0714 NR 29 TC 34 Z9 34 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 FEB 23 PY 1998 VL 80 IS 8 BP 1754 EP 1757 DI 10.1103/PhysRevLett.80.1754 PG 4 WC Physics, Multidisciplinary SC Physics GA YY143 UT WOS:000072117600047 ER PT J AU Aranson, IS Bishop, AR Daruka, I Vinokur, VM AF Aranson, IS Bishop, AR Daruka, I Vinokur, VM TI Ginzburg-Landau theory of spiral surface growth SO PHYSICAL REVIEW LETTERS LA English DT Article ID CRYSTAL-GROWTH; SIMULATION; DYNAMICS AB A description of the spiral crystal growth of thin films in terms of a Ginzburg-Landau-like continuum field equation is proposed. The phase of the complex order parameter is identified with the local height of the growing surface and the absolute value represents the density of crystalline phase. This theory describes the helicoidal configuration from the growth of a screw dislocation core, as well as spontaneous nucleation of new dislocation pairs. 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 Notre Dame, Dept Phys, Notre Dame, IN 46556 USA. RP Aranson, IS (reprint author), Argonne Natl Lab, 9700 S Cass Ave, Argonne, IL 60439 USA. RI Aranson, Igor/I-4060-2013 NR 22 TC 16 Z9 16 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 FEB 23 PY 1998 VL 80 IS 8 BP 1770 EP 1773 DI 10.1103/PhysRevLett.80.1770 PG 4 WC Physics, Multidisciplinary SC Physics GA YY143 UT WOS:000072117600051 ER PT J AU Dai, P Yethiraj, M Mook, HA Lindemer, TB Dogan, F AF Dai, P Yethiraj, M Mook, HA Lindemer, TB Dogan, F TI "Magnetic dynamics in underdoped YBa2Cu3O7-x: Direct observation of a superconducting gap" - Reply SO PHYSICAL REVIEW LETTERS LA English DT Article C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. Univ Washington, Seattle, WA 98195 USA. RP Dai, P (reprint author), Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RI Dai, Pengcheng /C-9171-2012 OI Dai, Pengcheng /0000-0002-6088-3170 NR 6 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 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD FEB 23 PY 1998 VL 80 IS 8 BP 1794 EP 1794 DI 10.1103/PhysRevLett.80.1794 PG 1 WC Physics, Multidisciplinary SC Physics GA YY143 UT WOS:000072117600060 ER PT J AU Kendall, RA Chalasinski, G Klos, J Bukowski, R Severson, MW Szczesniak, MM Cybulski, SM AF Kendall, RA Chalasinski, G Klos, J Bukowski, R Severson, MW Szczesniak, MM Cybulski, SM TI Ab initio study of the van der Waals interaction of NH(X-3 Sigma(-)) with Ar(S-1) SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID DIFFUSION MONTE-CARLO; POTENTIAL-ENERGY SURFACES; ADAPTED PERTURBATION-THEORY; STRETCH-BEND LEVELS; WATER DIMER; RANDOM-WALK; BASIS-SETS; INTERMOLECULAR INTERACTIONS; MOLECULAR INTERACTIONS; QUANTUM-CHEMISTRY AB The potential energy surface for the Ar(S-1)+NH(X (3)Sigma(-)) interaction is calculated using the supermolecular unrestricted Moller-Plesset (UMP) perturbation theory approach and analyzed via the perturbation theory of intermolecular forces. The global minimum occurs for the approximate T-shaped geometry with Ar skewed toward the H atom at about Theta = 67 degrees and R =6.75 a(0). Our UMP4 estimate of the well depth of the global minimum is D-e = 100.3 cm(-1) and the related ground state dissociation energy obtained by rigid-body diffusion quantum Monte Carlo calculations (RBDQMC) is D-0 = 71.5 +/- 0.1 cm(-1). These values are expected to be accurate to within a few percent. The potential energy surface also features a wide plateau in the proximity of Ar-N-H collinear geometry, at ca. 7.0 a(0). RBDQMC calculations reveal nearly a free rotation of the NH subunit in the complex. (C) 1998 American Institute of Physics. C1 Pacific NW Lab, High Performance Computat Chem Grp, Environm Mol Sci Lab, Richland, WA 99352 USA. Univ Warsaw, Dept Chem, PL-02093 Warsaw, Poland. Oakland Univ, Dept Chem, Rochester, MI 48309 USA. Miami Univ, Dept Chem, Oxford, OH 45056 USA. RP Kendall, RA (reprint author), Pacific NW Lab, High Performance Computat Chem Grp, Environm Mol Sci Lab, POB 999, Richland, WA 99352 USA. RI Klos, Jacek/A-6457-2008 OI Klos, Jacek/0000-0002-7407-303X NR 57 TC 35 Z9 35 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 FEB 22 PY 1998 VL 108 IS 8 BP 3235 EP 3242 DI 10.1063/1.475737 PG 8 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA ZW146 UT WOS:000074379600019 ER PT J AU Lamoen, D Persson, BNJ AF Lamoen, D Persson, BNJ TI Adsorption of potassium and oxygen on graphite: A theoretical study SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID DENSITY-FUNCTIONAL CALCULATIONS; ELECTRONIC-STRUCTURE; GASIFICATION REACTIONS; PLASMON FREQUENCY; ENERGY; PSEUDOPOTENTIALS; APPROXIMATION; CHARGE; CARBON; PLANE AB We have performed electronic structure calculations of the interaction of potassium and oxygen with graphite (GR), individually and as coadsorbates. We use up to three graphite planes to represent the graphite surface, but we show that the main physics is correctly described by a single graphite layer. At low coverage the potassium-graphite bond is largely ionic, and the variation of the K-GR bond energy with the lateral position of the K atom in the graphite unit cell is very small. We study the interaction between atomic oxygen and graphite, We find that O binds strongest at the bridge site, but the barrier for diffusion is rather small. The frequency for the perpendicular O-graphite vibrational mode is remarkably low (53 meV), reflecting the relative slow variation of the O-graphite interaction energy with the separation z between the O atom and the graphite surface. We consider the adsorption of O-2 on a clean graphite surface and on a graphite surface with a low concentration of potassium. On the clean surface the O-2-graphite interaction is found to be repulsive (the weak attractive van der Waals interaction is not included in our theoretical method), in accordance with the extremely low sticking coefficient observed for O-2 on clean graphite. When potassium is adsorbed on the graphite surface, O-2 chemisorbs at the potassium sites which is consistent with the large sticking coefficient observed for O-2 On a potassium covered surface. The energy barrier towards dissociation of O-2 On the clean graphite surface is estimated to be similar to that of gas phase O-2 For O-2 on K/graphite we find that O-2 chemisorbs "side-on" K, and that the barrier for dissociation is much smaller than in the gas phase or on the clean graphite surface. (C) 1998 American Institute of Physics. C1 Univ Instelling Antwerp, Dept Phys, B-2610 Antwerp, Belgium. Oak Ridge Natl Lab, Div Solid State, Oak Ridge, TN 37831 USA. Forschungszentrum Julich, Inst Festkorperforsch, D-52425 Julich, Germany. RP Univ Instelling Antwerp, Dept Phys, Univ Plein 1, B-2610 Antwerp, Belgium. RI Persson, Bo Nils Johan/I-1548-2013 OI Persson, Bo Nils Johan/0000-0003-1535-738X NR 30 TC 97 Z9 98 U1 1 U2 23 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 FEB 22 PY 1998 VL 108 IS 8 BP 3332 EP 3341 DI 10.1063/1.475732 PG 10 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA ZW146 UT WOS:000074379600032 ER PT J AU Falana, OM Koch, HF Roundhill, DM Lumetta, GJ Hay, BP AF Falana, OM Koch, HF Roundhill, DM Lumetta, GJ Hay, BP TI Synthesis and extraction studies of 1,2- and 1,3-disubstituted butylcalix[4]arene amides with oxyions; geometric and conformational effects SO CHEMICAL COMMUNICATIONS LA English DT Article ID LOWER-RIM; CALIX<4>ARENES; SUBSTITUENTS; REDUCTION AB 26,28-(Dibutylcarbamoyl)methoxy-5,11,17,23-tert-butylcalix[4]arene and two geometric isomers of 27,28-(dibutylcarbamoyl)methoxy-5,11,17,23-tert-butylcalix[4]arene have been used to extract U-VI, Mo-VI, Cr-VI and Se-VI from aqueous solution into toluene or isooctane. C1 Texas Tech Univ, Dept Chem & Biochem, Lubbock, TX 79409 USA. Pacific NW Lab, Richland, WA 99352 USA. RP Roundhill, DM (reprint author), Texas Tech Univ, Dept Chem & Biochem, Lubbock, TX 79409 USA. EM uldmr@ttacs.ttu.edu NR 20 TC 14 Z9 14 U1 1 U2 2 PU ROYAL SOC CHEMISTRY PI CAMBRIDGE PA THOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON ROAD, CAMBRIDGE CB4 4WF, CAMBS, ENGLAND SN 1359-7345 J9 CHEM COMMUN JI Chem. Commun. PD FEB 21 PY 1998 IS 4 BP 503 EP 504 DI 10.1039/a707786f PG 2 WC Chemistry, Multidisciplinary SC Chemistry GA YZ264 UT WOS:000072236700029 ER PT J AU Jensen, TR Norby, P Hanson, JC Skou, EM Stein, PC AF Jensen, TR Norby, P Hanson, JC Skou, EM Stein, PC TI Hydrothermal synthesis, crystal structure and thermal transformation of a new zinc arsenate hydrate, Zn-9(AsO4)(6)center dot 4H(2)O SO JOURNAL OF THE CHEMICAL SOCIETY-DALTON TRANSACTIONS LA English DT Article AB A new synthetic polymorph of zinc arsenate hydrate, Zn-9(AsO4)(6) . 4H(2)O, was prepared from an aqueous solution. Owing to the small size of the crystals, synchrotron X-ray radiation was applied for the indexing and data collection. An initial structural model was found from 1819 unique reflections measured (space group P (1) over bar, refined to wR = 0.154, R = 0.060). Optimisation of the synthesis conditions provided larger crystals for crystallographic measurements using a conventional diffractometer: a = 6.6895(3), b = 9.1761(4), c = 10.1377(8) Angstrom, alpha = 69.428(5), beta = 77.205(5), gamma = 75.765(4)degrees, space group P (1) over bar. The structure was refined to wR = 0.072, R = 0.061. The crystal structure of Zn-9(AsO4)(6) . H2O is built from chains of edge-sharing octahedra and trigonal-bipyramidal Zn atoms co-ordinated to framework oxygen and water molecule oxygen atoms These chains are connected by tetrahedra of Zn and As co-ordinated to framework oxygen atoms. Channels run along the a axis where the water molecules are placed. The compound transforms into a new phase of Zn-3(AsO4)(2) at 424(1) degrees C and into the known phase beta-Zn-3(AsO4)(2) at 865(1) degrees C. C1 Odense Univ, Dept Chem, DK-5230 Odense M, Denmark. SUNY Stony Brook, Dept Chem, Stony Brook, NY 11794 USA. Brookhaven Natl Lab, Dept Chem, Upton, NY 11973 USA. RP Jensen, TR (reprint author), Odense Univ, Dept Chem, DK-5230 Odense M, Denmark. RI Hanson, jonathan/E-3517-2010; Stein, Paul/M-9044-2015; Norby, Poul/B-9047-2014; OI Stein, Paul/0000-0002-7723-1419; Norby, Poul/0000-0002-2590-7050; Jensen, Torben Rene/0000-0002-4278-3221 NR 35 TC 6 Z9 6 U1 0 U2 0 PU ROYAL SOC CHEMISTRY PI CAMBRIDGE PA THOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON ROAD, CAMBRIDGE CB4 4WF, CAMBS, ENGLAND SN 0300-9246 J9 J CHEM SOC DALTON JI J. Chem. Soc.-Dalton Trans. PD FEB 21 PY 1998 IS 4 BP 527 EP 532 DI 10.1039/a706827a PG 6 WC Chemistry, Inorganic & Nuclear SC Chemistry GA ZD135 UT WOS:000072654900006 ER PT J AU Reynolds, PA Cable, JW Sobolev, AN Figgis, BN AF Reynolds, PA Cable, JW Sobolev, AN Figgis, BN TI Structure, covalence and spin polarisation in tris(acetylacetonato)ruthenium(III) studied by X-ray and polarised neutron diffraction SO JOURNAL OF THE CHEMICAL SOCIETY-DALTON TRANSACTIONS LA English DT Article ID ELECTRON-PARAMAGNETIC RESONANCE; COCL42 ION; DENSITY; TRANSITION; RUTHENIUM(III); MAGNETIZATION; COMPLEXES; CS3COCL5; CHARGE AB A polarised neutron diffraction (PND) experiment on [Ru(acac)(3)] at 4.18 K and 5 T along the b and c axes yielded 28 and 17 flipping ratios respectively. Single-crystal X-ray structure determinations at 293, 92 and 10.5 K, together with powder neutron diffraction experiments, provided auxiliary data allowing magnetic structure factors to be deduced from the PND experiment. The structure is disordered at all temperatures. There are ordered stacks of molecules along b, which stacks are arranged in the ac plane in two sites of relative displacement 0.4 Angstrom along b. The molecular geometries at the sites are similar and approximately D-3 in symmetry, but the magnetisation data indicate C-2 symmetry The PND data showed significant spin delocalisation by covalence onto the acetylacetonato rings, dominated by spin-polarisation effects, and of C-2 symmetry. However the two data sets differed, with the field along b indicating a (2)A and that along c a B-2 dominated state. This cannot be explained in the ligand-field model which fits the magnetic susceptibility data, indicating that vibronic effects must be explicitly considered. Good-quality ab-initio local density calculations reproduced the molecular geometry but grossly underestimated the spin correlation between metal and rings. C1 Australian Natl Univ, Res Sch Chem, Canberra, ACT 0200, Australia. Oak Ridge Natl Lab, Div Solid State, Oak Ridge, TN 37831 USA. Univ Western Australia, Dept Chem, Nedlands, WA 6009, Australia. RP Reynolds, PA (reprint author), Australian Natl Univ, Res Sch Chem, Canberra, ACT 0200, Australia. NR 53 TC 22 Z9 23 U1 0 U2 4 PU ROYAL SOC CHEMISTRY PI CAMBRIDGE PA THOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON ROAD, CAMBRIDGE CB4 4WF, CAMBS, ENGLAND SN 0300-9246 J9 J CHEM SOC DALTON JI J. Chem. Soc.-Dalton Trans. PD FEB 21 PY 1998 IS 4 BP 559 EP 569 DI 10.1039/a706681c PG 11 WC Chemistry, Inorganic & Nuclear SC Chemistry GA ZD135 UT WOS:000072654900011 ER PT J AU Ng, KY AF Ng, KY TI Quasi-isochronous buckets in storage rings SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article DE isochronous; momentum compaction; muon collider AB In order to maintain a reasonable r.f. system, it may be necessary for a collider with ultra-short bunches to operate with a small slippage factor, for example, eta < 1 x 10(-6) for all the particles in the bunches. The buckets dominated by the zeroth order, first order, or second order of eta are examined, and the required r.f. voltages are computed. The problem of microwave instability is addressed. The reliability of computing higher-order momentum-compaction factor using lattice codes is examined. (C) 1998 Elsevier Science B.V. All rights reserved. C1 Fermi Natl Accelerator Lab, Batavia, IL 60510 USA. RP Ng, KY (reprint author), Fermi Natl Accelerator Lab, MS 345,POB 500, Batavia, IL 60510 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 FEB 21 PY 1998 VL 404 IS 2-3 BP 199 EP 216 DI 10.1016/S0168-9002(97)01136-4 PG 18 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA YZ383 UT WOS:000072248900003 ER PT J AU Seidel, M Adolphsen, C Bane, KLF Jones, RM Kroll, NM Miller, RH Whittum, DH AF Seidel, M Adolphsen, C Bane, KLF Jones, RM Kroll, NM Miller, RH Whittum, DH TI Absolute beam position measurement in an accelerator structure SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article DE accelerator structures; wakefields; dipole modes; alignment; X-band ID LINEAR COLLIDERS AB High gradient acceleration requires exquisite control of beam position relative to the accelerating structure electrical center in order to avoid the excitation of transverse deflecting fields. We have measured such "absolute" beam position in a prototype X-band accelerator structure using beam induced microwave signals. We then verified our measurements independently by probing the beam excited field with a second witness bunch. Absolute beam positioning precision has been demonstrated at the level of 40 mu m. (C) 1998 Elsevier Science B.V. All rights reserved. C1 Stanford Univ, Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. Univ Calif San Diego, La Jolla, CA 92093 USA. RP Seidel, M (reprint author), Stanford Univ, Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. OI Jones, Roger/0000-0001-6528-214X NR 10 TC 7 Z9 7 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 FEB 21 PY 1998 VL 404 IS 2-3 BP 231 EP 236 DI 10.1016/S0168-9002(97)01169-8 PG 6 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA YZ383 UT WOS:000072248900006 ER PT J AU Appuhn, RD Arndt, C Barrelet, E Barschke, R Bassler, U Bipp, T Boudry, V Brasse, F Bruncko, D Buchholz, R Chechelnitski, S Claxton, B Cozzika, G Cvach, J Dagoret-Campagne, S Dau, WD Deckers, H Deckers, T Descamps, F Dirkmann, M Dowdell, J Efremenko, V Eisenhandler, E Eliseev, AN Falley, G Ferencei, J Fleischer, M Fominykh, B Gadow, K Goerlach, U Gorbov, LA Gorelov, I Grewe, M Hajduk, L Heck, A Herynek, I Hladky, J Hutte, M Hutter, H Janczur, W Janoth, J Jonsson, L Kolanoski, H Korbel, V Krivan, F Lacour, D Laforge, B Lamarche, F Landon, MPJ Laporte, JF Lehner, F Maracek, R Meier, K Meyer, A Migliori, A Moreau, F Muller, G Murin, P Nagovizin, V Nicholls, TC Ozerov, D Perez, E Pharabod, JP Poschl, R Rostovtsev, A Royon, C Rybicki, K Schediwy, R Schleif, S Schmitt, K Schuhmacher, A Semenov, A Shekelyan, V Sirois, Y Smirnov, PA Solochenko, V Spalek, J Spielmann, S Steiner, H Stellberger, A Stiewe, J Tasevsky, M Tchernyshov, V Thiele, K Tzamariudaki, E Valkar, S VanDenPlas, D Villet, G Wacker, K Walther, A Weber, M Wegener, D Wenk, T Zacek, J Zhokin, A Zuber, K AF Appuhn, RD Arndt, C Barrelet, E Barschke, R Bassler, U Bipp, T Boudry, V Brasse, F Bruncko, D Buchholz, R Chechelnitski, S Claxton, B Cozzika, G Cvach, J Dagoret-Campagne, S Dau, WD Deckers, H Deckers, T Descamps, F Dirkmann, M Dowdell, J Efremenko, V Eisenhandler, E Eliseev, AN Falley, G Ferencei, J Fleischer, M Fominykh, B Gadow, K Goerlach, U Gorbov, LA Gorelov, I Grewe, M Hajduk, L Heck, A Herynek, I Hladky, J Hutte, M Hutter, H Janczur, W Janoth, J Jonsson, L Kolanoski, H Korbel, V Krivan, F Lacour, D Laforge, B Lamarche, F Landon, MPJ Laporte, JF Lehner, F Maracek, R Meier, K Meyer, A Migliori, A Moreau, F Muller, G Murin, P Nagovizin, V Nicholls, TC Ozerov, D Perez, E Pharabod, JP Poschl, R Rostovtsev, A Royon, C Rybicki, K Schediwy, R Schleif, S Schmitt, K Schuhmacher, A Semenov, A Shekelyan, V Sirois, Y Smirnov, PA Solochenko, V Spalek, J Spielmann, S Steiner, H Stellberger, A Stiewe, J Tasevsky, M Tchernyshov, V Thiele, K Tzamariudaki, E Valkar, S VanDenPlas, D Villet, G Wacker, K Walther, A Weber, M Wegener, D Wenk, T Zacek, J Zhokin, A Zuber, K CA H1 SpCal Grp TI Series tests of fine mesh photomultiplier tubes in magnetic fields of up to 1.2 Tesla SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article ID CALORIMETER AB The new lead/scintillating-fibre calorimeter ("SpaCal") for the backward region of the H1 experiment at HERA (DESY) is equipped with fine mesh phototubes which operate in a magnetic field close to 1T, A large sample of these tubes of the types Hamamatsu R5505 and R5506, and Hamamatsu R2490-06, have been tested in fields of up to 1.2 T. We have investigated the cathode homogeneity with and without magnetic field, the gain loss under the influence of the magnetic field? and stability with time. For a subsample of tubes, we have performed additional studies on stability with respect to temperature changes, variation of gain as a function of the magnetic field, high voltage discharges, single photo-electron response, and linearity. We finally summarize the experience with these tubes after one year of operation in the experiment. (C) 1998 Elsevier Science B.V. All rights reserved. C1 DESY, D-2000 Hamburg, Germany. Univ Paris 06, LPNHE, Paris, France. Univ Paris 07, CNRS, IN2P3, Paris, France. Ecole Polytech, LPNHE, CNRS, IN2P3, Palaiseau, France. Slovak Acad Sci, Inst Expt Phys, Kosice 04353, Slovakia. Inst Theoret & Expt Phys, Moscow 117259, Russia. Rutherford Appleton Lab, Div Elect, Didcot OX11 0QX, Oxon, England. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. Ctr Etud Saclay, DAPNIA, DSM, CEA, F-91191 Gif Sur Yvette, France. Acad Sci Czech Republ, Inst Phys, Prague, Czech Republic. Univ Kiel, Inst Reine & Angew Kernphys, D-2300 Kiel, Germany. Univ Dortmund, Inst Phys, D-4600 Dortmund, Germany. Univ London Queen Mary & Westfield Coll, London E1 4NS, England. PN Lebedev Phys Inst, Moscow 117924, Russia. Inst Nucl Phys, Krakow, Poland. Univ Heidelberg, Inst Hochenergiephys, Heidelberg, Germany. Univ Lund, Dept Phys, S-22100 Lund, Sweden. Univ Birmingham, Sch Phys & Space Res, Birmingham B15 2TT, W Midlands, England. Charles Univ, Nucl Ctr, Prague, Czech Republic. RP Appuhn, RD (reprint author), DESY, Notkestr 85, D-2000 Hamburg, Germany. RI Gorelov, Igor/J-9010-2015; Ozerov, Dmitry/E-9139-2016; Cvach, Jaroslav/G-6269-2014; OI Gorelov, Igor/0000-0001-5570-0133; Bassler, Ursula/0000-0002-9041-3057 NR 15 TC 4 Z9 4 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 FEB 21 PY 1998 VL 404 IS 2-3 BP 265 EP 282 DI 10.1016/S0168-9002(97)01092-9 PG 18 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA YZ383 UT WOS:000072248900009 ER PT J AU Komatsubara, TK Morimoto, T Omata, K Sugimoto, S Tauchi, K Inagaki, T Kabe, S Kobayashi, M Kuno, Y Sato, T Shinkawa, T Yoshimura, Y Chiang, IH Kettell, S Li, KK Littenberg, LS Yamashita, A Suzuki, H Suzuki, S AF Komatsubara, TK Morimoto, T Omata, K Sugimoto, S Tauchi, K Inagaki, T Kabe, S Kobayashi, M Kuno, Y Sato, T Shinkawa, T Yoshimura, Y Chiang, IH Kettell, S Li, KK Littenberg, LS Yamashita, A Suzuki, H Suzuki, S TI Performance of fine-mesh photomultiplier tubes designed for an undoped-CsI endcap photon detector SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article DE fine-mesh photomultiplier tube; magnetic field; gain; undoped-CsI; endcap; E787 ID HIGH MAGNETIC-FIELD; SEARCH; K+->PI+NU(NU)OVER-BAR AB We have developed two types of fine-mesh photomultiplier tubes for an undoped-CsI endcap photon detector installed in a strong axial magnetic field. These photomultiplier tubes have ultraviolet-transmitting glass windows, backed by large-area bialkali photocathodes, in order to efficiently detect scintillation light from undoped-CsI crystals. A gain of more than 2 x 10(5), in a magnetic field of 1.0 T, was obtained from these tubes with 19-stage fine-mesh dynodes, Gain drops caused by the magnetic field and by high anode currents were investigated. Several performance criteria of the tubes were studied: gain, quantum efficiency, linearity, noise, and transit time spread. (C) 1998 Elsevier Science B.V. All rights reserved. C1 High Energy Accelerator Res Org, Tanashi Branch, Tanashi, Tokyo 188, Japan. High Energy Accelerator Res Org, Tsukuba, Ibaraki 305, Japan. Brookhaven Natl Lab, Upton, NY 11973 USA. Hamamatsu Photon KK, Electron Tube Ctr, Toyooka, Shizuoka 43801, Japan. RP Komatsubara, TK (reprint author), High Energy Accelerator Res Org, Tanashi Branch, 3-2-1 Midori Cho, Tanashi, Tokyo 188, Japan. OI Littenberg, Laurence/0000-0001-8373-7179 NR 28 TC 23 Z9 23 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 FEB 21 PY 1998 VL 404 IS 2-3 BP 315 EP 326 DI 10.1016/S0168-9002(97)01107-8 PG 12 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA YZ383 UT WOS:000072248900014 ER PT J AU Buchalter, A Helfand, DJ Becker, RH White, RL AF Buchalter, A Helfand, DJ Becker, RH White, RL TI Constraining Omega(0) with the angular size redshift relation of double-lobed quasars in the first survey SO ASTROPHYSICAL JOURNAL LA English DT Article DE cosmology, observations; galaxies, fundamental parameters; quasars, general; radio continuum, galaxies ID EXTRAGALACTIC RADIO-SOURCES; LUMINOSITY DEPENDENCE; INFRARED PROPERTIES; SOURCE ORIENTATION; LINEAR SIZES; GALAXIES; EVOLUTION; MORPHOLOGY; STATISTICS; PROBE AB In previous attempts to measure cosmological parameters from the angular size-redshift (theta-z) relation of double-lobed radio sources, the observed data have generally been consistent with a static Euclidean universe rather than with standard Friedmann models, and past authors have disagreed significantly as to what effects are responsible for this observation. These results and different interpretations may be due largely to a variety of selection effects and differences in the sample definitions destroying the integrity of the data sets, and inconsistencies in the analysis undermining the results. Using the VLA FIRST survey, we investigate the theta-z relation for a new sample of double-lobed quasars. We define a set of 103 sources, carefully addressing the various potential problems that, we believe, have compromised past work,. including a robust definition of size and the completeness and homogeneity of the sample, and further devise a self-consistent method to assure accurate morphological classification and account for finite resolution effects in the analysis. Before focusing on cosmological constraints, we investigate the possible impact of correlations among the intrinsic properties of these sources over the entire assumed range of allowed cosmological parameter values. For all cases, we find apparent size evolution of the form l proportional to(1 + z)(c), with c approximate to -0.8 +/- 0.4, which is found to arise mainly from a power-size correlation of the form l proportional to P-beta (beta approximate to -0.13 +/- 0.06) coupled with a power-redshift correlation. Intrinsic size evolution is consistent with zero. We also find that in all cases, a subsample with c approximate to 0 can be defined, whose theta-z relation should therefore arise primarily from cosmological effects. These results are found to be independent of orientation effects, although other evidence indicates that orientation effects are present and consistent with predictions of the unified scheme for radio-loud active galactic nuclei. The above results are all confirmed by nonparametric analysis. Contrary to past work, we find that the observed theta-z relation for our sample is more consistent with standard Friedmann models than with a static Euclidean universe. Though the current data cannot distinguish with high significance between various Friedmann models, significant constraints on the cosmological parameters within a given model are obtained. In particular, we find that a flat, matter-dominated universe (theta(0) = 1), a flat universe with a cosmological constant, and an open universe all provide comparably good fits to the data, with the latter two models both yielding Ohm(0) approximate to 0.35 with 1 sigma ranges including values between similar to 0.25 and 1.0; the c approximate to 0 subsamples yield values of Ohm(0), near unity in these models, though with even greater error ranges. We also examine the values of H-0 implied by the data, using plausible assumptions about the intrinsic source sizes, and find these to be consistent with the currently accepted range of values. We determine the sample size needed to improve significantly the results and outline future strategies for such work. C1 Columbia Univ, Dept Astron, New York, NY 10027 USA. Univ Calif Davis, Dept Phys, Davis, CA 95616 USA. Space Telescope Sci Inst, Baltimore, MD 21218 USA. Lawrence Livermore Natl Lab, IGPP, Livermore, CA 94550 USA. RP Columbia Univ, Dept Astron, New York, NY 10027 USA. EM ari@astro.columbia.edu; djh@astro.columbia.edu; bob@igpp.llnl.gov; rlw@stsci.edu NR 53 TC 39 Z9 41 U1 0 U2 0 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0004-637X EI 1538-4357 J9 ASTROPHYS J JI Astrophys. J. PD FEB 20 PY 1998 VL 494 IS 2 BP 503 EP 522 DI 10.1086/305236 PN 1 PG 20 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA YZ796 UT WOS:000072292500003 ER PT J AU Liu, WH Jeffery, DJ Schultz, DR AF Liu, WH Jeffery, DJ Schultz, DR TI Ionization of type Ia supernovae: Electron impact, photon impact, or charge transfer? SO ASTROPHYSICAL JOURNAL LA English DT Article DE atomic data; atomic processes; supernovae, general ID PHOTOIONIZATION CROSS-SECTIONS; OSCILLATOR-STRENGTHS; ENERGY DEPOSITION; FE-III; MODELS; RECOMBINATION; EXCITATION; ATOMS; IONS AB The ionization structure of the nebular Type Ia supernova iron core is determined by treating important atomic processes with the best available evaluated atomic data and by assuming both Chandrasekhar-mass and sub-Chandrasekhar-mass white dwarf explosion models. The electron impact ionization rates are calculated by analyzing the energetic electron energy deposition processes. Charge transfer processes between neutral and ionized iron-group elements are included in the calculations using the recently available rate coefficients. The effect of photoionization due to the recombination photons is critically evaluated by carrying out a detailed cascade calculation using the recently improved state-specific rate coefficients of radiative recombination and cross sections of photoionization of iron. It is concluded that the ionization structure is mainly controlled by a combination of the energetic electron impact ionization and charge transfer, while the photoionization plays only a minor role and its effect on the synthetic spectra is small. C1 Oak Ridge Natl Lab, Div Phys, Oak Ridge, TN 37831 USA. RP Liu, WH (reprint author), Oak Ridge Natl Lab, Div Phys, Oak Ridge, TN 37831 USA. NR 23 TC 11 Z9 11 U1 0 U2 0 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 FEB 20 PY 1998 VL 494 IS 2 BP 812 EP 815 DI 10.1086/305249 PN 1 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA YZ796 UT WOS:000072292500031 ER PT J AU Zhang, DS Wei, GW Kouri, DJ Hoffman, DK AF Zhang, DS Wei, GW Kouri, DJ Hoffman, DK TI Lagrange distributed approximating functional method for the solution of the Schrodinger equation SO CHEMICAL PHYSICS LETTERS LA English DT Article ID LIPPMANN-SCHWINGER EQUATIONS; EIGENFUNCTIONS; DYNAMICS; FORMS AB The utility and accuracy of a new distributed approximating functional (DAF), combining the Gaussian weighted DAF concept with Lagrange interpolation, is explored for the discrete spectrum solution of the Schrodinger equation. Two instructive examples, an I-2 Morse oscillator and the 2-dimensional Henon-Heiles potential, are considered in the present study. The present "Lagrange DAF" (LDAF) approach achieves extremely high accuracy for I-2 while using fewer grid points than previous approaches. The present results for the Henon-Heiles system are in excellent agreement with those of earlier established methods, such as that of Shizgal. (C) 1998 Elsevier Science B.V. C1 Univ Houston, Dept Chem, Houston, TX 77204 USA. Univ Houston, Dept Phys, Houston, TX 77204 USA. Iowa State Univ, Dept Chem, Ames, IA 50011 USA. Iowa State Univ, Ames Lab, Ames, IA 50011 USA. RP Zhang, DS (reprint author), Univ Houston, Dept Chem, Univ Pk, Houston, TX 77204 USA. RI Wei, Guowei /E-1852-2011 NR 35 TC 7 Z9 7 U1 1 U2 1 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 FEB 20 PY 1998 VL 284 IS 1-2 BP 56 EP 62 DI 10.1016/S0009-2614(97)01360-2 PG 7 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA ZD959 UT WOS:000072742900009 ER PT J AU Haschke, JM Martz, JC AF Haschke, JM Martz, JC TI Oxidation kinetics of plutonium in air from 500 to 3500 degrees C - Application to source terms for dispersal SO JOURNAL OF ALLOYS AND COMPOUNDS LA English DT Article DE plutonium; oxidation; kinetics; dispersal AB The oxidation kinetics of plutonium in air are described for the autothermic regime using literature data and are applied in defining source-term relationships for dispersal. The oxidation rate of static plutonium is temperature independent (E-a=0) above the 500 degrees C ignition point, but that of ignited droplets is temperature dependent (E-a=9.6 kcal mol(-1)) during free fall in air. Kinetic dependences on humidity and alloying with gallium are absent. The appearance of a constant rate (0.2 g PuO2 cm(-2) min(-1)) for oxidation of static metal above 500 degrees C is attributed to formation of an oxygen-depleted boundary layer of nitrogen at the gas-solid interface during oxidation. The rate is temperature dependent under dynamic conditions that disturb or destroy the boundary layer. The ignition point of Pu is accurately predicted using a first-principles kinetic model and rate data for dynamic conditions. Arrhenius behavior, which is defined by combining the kinetic results with data for low temperature oxidation, is reflected in aerosol release rates reported for self-sustained oxidation of plutonium. The time-dependent source term for continuous release of PuO2 particles during reaction is defined, and the dependences of the airborne release fraction on oxidation temperatures and air velocity are described. (C) 1998 Elsevier Science S.A. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Haschke, JM (reprint author), Univ Calif Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. NR 24 TC 17 Z9 22 U1 0 U2 7 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0925-8388 J9 J ALLOY COMPD JI J. Alloy. Compd. PD FEB 20 PY 1998 VL 266 IS 1-2 BP 81 EP 89 DI 10.1016/S0925-8388(97)00499-4 PG 9 WC Chemistry, Physical; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Chemistry; Materials Science; Metallurgy & Metallurgical Engineering GA ZB161 UT WOS:000072442500016 ER PT J AU Martz, JC Haschke, JM AF Martz, JC Haschke, JM TI A mechanism for combustive heating and explosive dispersal of plutonium SO JOURNAL OF ALLOYS AND COMPOUNDS LA English DT Article DE plutonium; explosion; oxidation; dispersal ID WATER AB A first-principles model is developed for defining the combustive explosion of ignited plutonium droplets during free-fall in air and for quantifying fractions of plutonium aerosolization. The model, which is based on literature data and a conceptual description of the combustion and explosion processes, determines heat accumulation and temperature of a droplet over time using the rates of oxidation and heat loss, as well as physical and thermochemical properties of plutonium metal and oxide. Self-heating during combustion leads to fusion of the oxide layer and pressurization of the droplet by plutonium vapor that ultimately vents through the molten oxide to produce fume aerosol and a hollow spherule of residual oxide. Observed dependencies of time-to-explosion and aerosolized fraction on droplet size are accurately calculated by the model. All ignited droplets with sizes greater than a threshold diameter (approximately 0.01 cm) explode with aerosolization of residual plutonium (68-75%), if the free-fall period or distance is sufficient for the droplet temperature to exceed 3300 degrees C. A practical size window for explosion is bounded by the threshold value and by the diameter (about 9.13 cm) of a droplet that attains the explosion temperature during a free-fall distance of ten meters. Calculations show that a 1.0 cm-diameter drop heated initially to 1000 degrees C is 0.3% oxidized after free-falling for this distance in 1000 degrees C air and reaches a maximum temperature of 1560 degrees C. Since minimum diameters of one centimeter are observed for naturally occurring plutonium drops during containment failures at 1000 degrees C and the amount of dispersible plutonium is limited by the extent of oxidation, the reliability of large aerosol release fractions recommended in the literature for fuel-fire scenarios are questionable. Effects of independent variables on combustion and explosion are discussed and application of the model in predicting aerosol fractions released by plutonium fragments formed during highly energetic events is described. (C) 1998 Elsevier Science S.A. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Haschke, JM (reprint author), Univ Calif Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. NR 25 TC 8 Z9 12 U1 0 U2 5 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0925-8388 J9 J ALLOY COMPD JI J. Alloy. Compd. PD FEB 20 PY 1998 VL 266 IS 1-2 BP 90 EP 103 DI 10.1016/S0925-8388(97)00498-2 PG 14 WC Chemistry, Physical; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Chemistry; Materials Science; Metallurgy & Metallurgical Engineering GA ZB161 UT WOS:000072442500017 ER PT J AU Kleinke, H Franzen, HF AF Kleinke, H Franzen, HF TI Hf5CoAs3, the first Hf rich hafnium cobalt arsenide: intercalation of Co vs a Co/As exchange SO JOURNAL OF ALLOYS AND COMPOUNDS LA English DT Article DE metal-rich arsenide; crystal structure; electronic structure; magnetic properties ID NI AB Hf5CoAs3 was prepared by are-melting of HfAs, Hf and Co. This new arsenide crystallizes in the orthorhombic space group Pnma with cell dimensions of a=17.327(5)Angstrom, b=3.685(4)Angstrom, c=10.370(4)Angstrom, V=662(1)Angstrom(3). Its crystal structure is isostructural to the structure of Hf5CoP3. The Co and As atoms both are located in trigonal prismatic voids of the Hf substructure. The Hf atoms form double channels, each of which is filled with an infinite -Co-As-zigzag chain. These double channels are interconnected via bonding Hf-Hf interactions to form the three-dimensional Hf substructure. Since adding more Co occurs with significantly enlarged cell dimensions, it is concluded that the additional Co atoms are included in the structure of Hf5CoAs3, as Ni is in case of Hf5Ni1+xP3. The densities of states obtained by Extended Huckel calculations and the Pauli paramagnetism experimentally obtained point to metallic behavior of Hf5CoAs3. (C) 1998 Elsevier Science S.A. C1 Iowa State Univ, DOE, Ames Lab, Ames, IA 50011 USA. Univ Marburg, Fb Chem, D-35032 Marburg, Germany. RP Franzen, HF (reprint author), Iowa State Univ, DOE, Ames Lab, Ames, IA 50011 USA. NR 16 TC 2 Z9 2 U1 0 U2 1 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0925-8388 J9 J ALLOY COMPD JI J. Alloy. Compd. PD FEB 20 PY 1998 VL 266 IS 1-2 BP 139 EP 144 DI 10.1016/S0925-8388(97)00442-8 PG 6 WC Chemistry, Physical; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Chemistry; Materials Science; Metallurgy & Metallurgical Engineering GA ZB161 UT WOS:000072442500024 ER PT J AU Zeng, LM Franzen, HF AF Zeng, LM Franzen, HF TI Crystal structure of a new compound Bi2NdNi SO JOURNAL OF ALLOYS AND COMPOUNDS LA English DT Article DE crystal structure; rare-earth; bismuth AB The crystal structure of the new ternary compound Bi2NdNi has been determined from single-crystal X-ray data. The compound crystallizes in tetragonal, space group P4/nmm, (No. 129) with a=4.525(2) Angstrom, c=9.546(4) Angstrom, V=195.5(1) Angstrom(3), and Z=2 at room temperature. The structure refinement (R=0.053, R-w=0.052) showed the compound has a defect AsCuSiZr structure. (C) 1998 Elsevier Science S.A. C1 Iowa State Univ, Ames Lab, US DOE, Ames, IA 50011 USA. RP Franzen, HF (reprint author), Iowa State Univ, Ames Lab, US DOE, Ames, IA 50011 USA. NR 9 TC 5 Z9 5 U1 0 U2 0 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0925-8388 J9 J ALLOY COMPD JI J. Alloy. Compd. PD FEB 20 PY 1998 VL 266 IS 1-2 BP 155 EP 157 DI 10.1016/S0925-8388(97)00517-3 PG 3 WC Chemistry, Physical; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Chemistry; Materials Science; Metallurgy & Metallurgical Engineering GA ZB161 UT WOS:000072442500027 ER PT J AU Ting, EY Porter, MD AF Ting, EY Porter, MD TI Electrochemically modulated liquid chromatography (EMLC) as a probe of the adsorption characteristics of monosubstituted benzenes at porous graphitic carbon SO JOURNAL OF ELECTROANALYTICAL CHEMISTRY LA English DT Article DE stationary phases; liquid chromatography; electrochemically modulated liquid chromatography; porous graphitic carbon; adsorption; monosubstituted benzenes ID STATIONARY-PHASE; SEPARATIONS; RETENTION; PERFORMANCE; ELECTRODES; POLYPYRROLE; AFFINITY; COLUMN AB The utility of electrochemically modulated liquid chromatography (EMLC) as a probe of the adsorption characteristics of monosubstituted benzenes at porous graphitic carbon (PGC) is investigated. An analysis on the extent of the changes in retention as a function of applied potential (E-appl) is performed to develop preliminary insights into the critical interactions between these compounds and PGC. The results show that the retention, and therefore the extent of adsorption, of these compounds increases as E-appl becomes more positive. Furthermore, the dependence of the increase varies between compounds, reflecting differences in the sensitivities of the adsorption strengths to pi-donor/acceptor interactions. Together, these results demonstrate the potential value of EMLC as (1) a tool for investigating fundamental issues related to the adsorption of organic compounds on electrode surfaces and (2) a separation technique for mixtures of this important class of analytes. (C) 1998 Elsevier Science S.A. All rights reserved. C1 Iowa State Univ, Ames Lab, US DOE, Microanalyt Instrumentat Ctr, Ames, IA 50011 USA. Iowa State Univ, Dept Chem, Ames, IA 50011 USA. RP Porter, MD (reprint author), Iowa State Univ, Ames Lab, US DOE, Microanalyt Instrumentat Ctr, Ames, IA 50011 USA. EM mporter@porter1.ameslab.gov NR 33 TC 14 Z9 14 U1 0 U2 0 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 FEB 20 PY 1998 VL 443 IS 2 BP 180 EP 185 DI 10.1016/S0022-0728(97)00551-2 PG 6 WC Chemistry, Analytical; Electrochemistry SC Chemistry; Electrochemistry GA ZG326 UT WOS:000072990300004 ER PT J AU Homes, CC Kamal, S Bonn, DA Liang, R Hardy, WN Clayman, BP AF Homes, CC Kamal, S Bonn, DA Liang, R Hardy, WN Clayman, BP TI Determination of the condensate from optical techniques in unconventional superconductors SO PHYSICA C LA English DT Article DE unconventional superconductivity; high-T-c superconductors; anisotropic; far infrared; microwave ID C-AXIS; INPLANE ANISOTROPY; PENETRATION DEPTH; CHARGE DYNAMICS; GAP ANISOTROPY; YBA2CU3O6+X; YBA2CU3O7-DELTA; PSEUDOGAP; YBA2CU4O8 AB The optical properties of superconductors, in particular the real parts of the conductivity and the dielectric function, may he used to calculate the strength of the condensate. In systems where all the free carriers collapse into the condensate, this approach works well. However, in gapless systems, and in unconventional systems in which the superconducting energy gap is observed to have zeros at the Fermi surface. there is usually considerable amount of residual conductivity at low frequency. This is the case in many of the cuprate-based high-temperature superconductors. In particular. YBa2Cu3O7-delta is almost perfectly stoichiometric with little chemical disorder(delta approximate to 0), yet there is a. large amount of residual conductivity both in the copper-oxygen planes as well as perpendicular to the planes for T much less than T-c, due to the presumed unconventional nature of the energy gap. The assumption that the condensate dominates the optical response at low frequencies lends to optical estimates for the condensate which are too large. However, the microwave surface reactance depends only upon the condensate and is not affected by the presence of residual conductivity (which affects the surface resistance), thus allowing an unambiguous determination of the strength of the condensate. When optical techniques are used in conjunction with microwave techniques. a more complete physical picture emerges. This problem is examined and resolved for the oxygen 'overdoped' YBa2Cu3O6.99 material along the c axis. (C) 1998 Elsevier Science B.V. C1 Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. Univ British Columbia, Dept Phys & Astron, Vancouver, BC V6T 1Z1, Canada. Simon Fraser Univ, Dept Phys, Burnaby, BC V5A 1S6, Canada. RP Homes, CC (reprint author), Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. EM homes@bnl.gov NR 29 TC 7 Z9 7 U1 1 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4534 J9 PHYSICA C JI Physica C PD FEB 20 PY 1998 VL 296 IS 3-4 BP 230 EP 240 DI 10.1016/S0921-4534(97)01840-6 PG 11 WC Physics, Applied SC Physics GA ZK636 UT WOS:000073345200009 ER PT J AU Kaiser, RI Ochsenfeld, C Head-Gordon, M Lee, YT AF Kaiser, RI Ochsenfeld, C Head-Gordon, M Lee, YT TI The formation of HCS and HCSH molecules and their role in the collision of comet Shoemaker-Levy 9 with Jupiter SO SCIENCE LA English DT Article ID GAUSSIAN-BASIS SETS; IMPACT; THIOFORMALDEHYDE; SPECTROSCOPY; ATMOSPHERE; BEAM AB The reaction of hydrogen sulfide with ground-state atomic carbon was examined with crossed molecular beams experiments and ab initio calculations. The thiohydroxycarbene molecule, HCSH, was the reactive intermediate, which fragmented into atomic hydrogen and the thioformyl radical HCS. This finding may account for the unassigned HCS source and an unidentified HCSH radical needed to match observed CS abundances from the collision of comet Shoemaker-Levy 9 into Jupiter. In the shocked jovian atmosphere, HCS could further decompose to H and CS, and CS could react with SH and OH to yield the observed CS2 and COS. C1 Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Chem Sci, Berkeley, CA 94720 USA. RP Kaiser, RI (reprint author), Acad Sinica, Inst Atom & Mol Sci, 1,Sect 4,Roosevelt Rd, Taipei 116, Taiwan. RI Lee, Yuan-Tseh/F-7914-2012; Ochsenfeld, Christian/E-8021-2015 OI Ochsenfeld, Christian/0000-0002-4189-6558 NR 30 TC 31 Z9 31 U1 0 U2 5 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 FEB 20 PY 1998 VL 279 IS 5354 BP 1181 EP 1184 DI 10.1126/science.279.5354.1181 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA YY119 UT WOS:000072115200034 PM 9469802 ER PT J AU Moler, KA Kirtley, JR Hinks, DG Li, TW Xu, M AF Moler, KA Kirtley, JR Hinks, DG Li, TW Xu, M TI Images of interlayer Josephson vortices in Tl2Ba2CuO6+delta SO SCIENCE LA English DT Article ID HIGH-TC SUPERCONDUCTORS; HALL-PROBE MICROSCOPY; COUPLED LAYER MODEL; CUO2 PLANES; PSEUDOGAP; FIELD AB The strength of the interlayer Josephson tunneling in layered superconductors is an essential test of the interlayer tunneling model as a mechanism for superconductivity, as well as a useful phenomenological parameter. A scanning superconducting quantum interference device (SQUID) microscope was used to image interlayer Josephson vortices in Tl2Ba2CuO6+delta and to obtain a direct measure of the interlayer tunneling in a high-transition temperature superconductor with a single copper oxide plane per unit cell. The measured interlayer penetration depth, lambda(c), is similar to 20 micrometers, about 20 times the penetration depth required by the interlayer tunneling model. C1 Princeton Univ, Dept Phys, Princeton, NJ 08544 USA. IBM Corp, Thomas J Watson Res Ctr, Yorktown Heights, NY 10598 USA. Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. Univ Chicago, James Franck Inst, Chicago, IL 60637 USA. RP Moler, KA (reprint author), Princeton Univ, Dept Phys, Princeton, NJ 08544 USA. RI Moler, Kathryn/F-2541-2011 NR 37 TC 130 Z9 130 U1 2 U2 13 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 FEB 20 PY 1998 VL 279 IS 5354 BP 1193 EP 1196 DI 10.1126/science.279.5354.1193 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA YY119 UT WOS:000072115200038 ER PT J AU Mohri, H Bonhoeffer, S Monard, S Perelson, AS Ho, DD AF Mohri, H Bonhoeffer, S Monard, S Perelson, AS Ho, DD TI Rapid turnover of T lymphocytes in SIV-infected rhesus macaques SO SCIENCE LA English DT Article ID HIV-1 INFECTION; LIFE-SPAN; IN-VIVO; CELLS; MEMORY; ACTIVATION; LENGTH; NAIVE; DEATH; CD4 AB Studies of lymphocyte turnover in animal models have implications for understanding the mechanism of cell killing and the extent of lymphocyte regeneration in human immunodeficiency virus infection. Quantitative analyses of the sequential changes in bromodeoxyuridine labeling of CD4 and CD8 T lymphocytes not only revealed the normal proliferation and death rates of these cell populations in uninfected macaques, but also showed a substantial increase in these rates associated with simian immunodeficiency virus (SIV) infection. Faster labeling and delabeling in memory and naive T lymphocyte subpopulations as well as in NK (natural killer) and B cells were also observed in infected macaques, suggesting a state of generalized activation induced by SIV. C1 Rockefeller Univ, Aaron Diamond AIDS Res Ctr, New York, NY 10016 USA. Univ Calif Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. RP Ho, DD (reprint author), Rockefeller Univ, Aaron Diamond AIDS Res Ctr, 455 1st Ave, New York, NY 10016 USA. EM dho@adarc.org RI Bonhoeffer, Sebastian/A-2735-2008 OI Bonhoeffer, Sebastian/0000-0001-8052-3925 FU NIAID NIH HHS [AI40387, AI41534, AI45128] NR 28 TC 249 Z9 250 U1 0 U2 2 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 FEB 20 PY 1998 VL 279 IS 5354 BP 1223 EP 1227 DI 10.1126/science.279.5354.1223 PG 5 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA YY119 UT WOS:000072115200048 PM 9469816 ER PT J AU Allerman, AA Kurtz, SR Biefeld, RM Baucom, KC AF Allerman, AA Kurtz, SR Biefeld, RM Baucom, KC TI 10-stage, 'cascaded' InAsSb quantum well laser at 3.9 mu m SO ELECTRONICS LETTERS LA English DT Article AB Injection lasers with type I, multiple (or 'cascaded') electron-hole recombination stages have been demonstrated. Laser emission at 3.9 mu m was observed up to 170K. The device had a 10-stage active region with each stage composed of a semi-metal, electron-hole source and three strained InAsSb quantum wells separated by InAsP barriers. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Allerman, AA (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. NR 7 TC 7 Z9 7 U1 0 U2 0 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 FEB 19 PY 1998 VL 34 IS 4 BP 369 EP 370 DI 10.1049/el:19980304 PG 2 WC Engineering, Electrical & Electronic SC Engineering GA YZ226 UT WOS:000072232900038 ER PT J AU Rodriguez, JA Chaturvedi, S Hanson, JC Albornoz, A Brito, JL AF Rodriguez, JA Chaturvedi, S Hanson, JC Albornoz, A Brito, JL TI Electronic properties and phase transformations in CoMoO4 and NiMoO4: XANES and time-resolved synchrotron XRD studies SO JOURNAL OF PHYSICAL CHEMISTRY B LA English DT Article ID X-RAY-ABSORPTION; TRANSITION-METAL OXIDES; NICKEL MOLYBDATE; OXIDATIVE DEHYDROGENATION; FINE-STRUCTURE; SELECTIVE OXIDATION; CATALYSTS; EDGE; SURFACE; BUTANE AB The thermal stability of a series of cobalt and nickel molybdates (AMoO4 . nH(2)O, alpha-AMo(4), and beta-AMoO(4); A = Co or Ni) was examined using synchrotron-based time-resolved X-ray powder diffraction (XRD). The results of X-ray absorption near-edge spectroscopy (XANES) indicate that the Co and Ni atoms are in octahedral sites in all these compounds, while the coordination of Mo varies from octahedral in the alpha-phases to tetrahedral in the beta-phases and hydrates. Upon heating of AMoO(4) . nH(2)O, evolution-of gaseous water was seen at two different temperature ranges: 100-200 degrees C for reversibly bound H2O; 200-400 degrees C for H2O from the crystal structure. The results of time-resolved XRD show a direct transformation of the hydrates into the beta-AMoO(4) compounds (following a kinetics of first order) without any intermediate phase. This is probably facilitated by the similarities that AMoO4 . nH(2)O and beta-AMoO(4) have in their structural and electronic properties. The XRD experiments show that the alpha-AMoO(4)-->beta-AMoO(4) transitions occur at much higher temperatures than the hydrate --> beta-AMoO(4) transformations (Delta T approximate to 150 degrees C in CoMoO4 and 280 degrees C in NiMoO4). The activation energy for the alpha-NiMoO4 --> beta-NiMoO4 transition is similar to 40 kcal/mol larger than that for the NiMoO4 . nH(2)O --> beta-NiMoO4 + nH(2)O reaction. The larger activation energy reflects the change in the coordination of Mo (O-h --> T-d) that occurs during the alpha --> beta transition. The K- and L-edges of Co in XANES spectra indicate that there are no big variations in the electronic properties of this metal when comparing CoMoO4 . nH(2)O, alpha-CoMoO4, and beta-CoMoO4. The same is valid for the electronic properties of Ni in the nickel molybdates. In contrast, the L-2,L-3-edges of Mo show large changes in the splitting of the Mo 4d orbitals as the coordination of this metal varies from octahedral (alpha-phases) to tetrahedral (beta-phases and hydrates). The features near the threshold in the O K-edge spectra track very well the splitting of the Mo 4d orbitals in tetrahedral and,octahedral fields and can be very useful for probing the local symmetry of Mo atoms in molybdenum oxides. C1 Brookhaven Natl Lab, Dept Chem, Upton, NY 11973 USA. Inst Venezolano Invest Cient, Ctr Quim, Caracas 1020A, Venezuela. RP Rodriguez, JA (reprint author), Brookhaven Natl Lab, Dept Chem, Upton, NY 11973 USA. RI Brito, Joaquin/F-4974-2010; Hanson, jonathan/E-3517-2010 NR 53 TC 77 Z9 77 U1 8 U2 44 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 FEB 19 PY 1998 VL 102 IS 8 BP 1347 EP 1355 DI 10.1021/jp972137q PG 9 WC Chemistry, Physical SC Chemistry GA YY564 UT WOS:000072160800002 ER PT J AU Schlei, BR Strottman, D Xu, N AF Schlei, BR Strottman, D Xu, N TI The linear correlation coefficient vs. the cross term in Bose-Einstein correlations SO PHYSICS LETTERS B LA English DT Article ID HEAVY-ION COLLISIONS; NUCLEUS-NUCLEUS COLLISIONS; HYDRODYNAMICAL ANALYSIS; INTERFEROMETRY AB We investigate the nature of the new cross term for Gaussian parameterizations of Bose-Einstein correlations of identical particles emitted from purely chaotic hadron sources formed by relativistic heavy ion collisions. We find that this additional parameter in the so-called Bertsch-Pratt parameterization can be expressed in terms of a linear "out-longitudinal" correlation coefficient for emission of bosons and two already known "radius" parameters, R-l and R-o. The linear correlation coefficient is of kinematical origin and can be used to determine the widths of longitudinal momentum distributions. (C) 1998 Elsevier Science B.V. 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 28 TC 8 Z9 8 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0370-2693 J9 PHYS LETT B JI Phys. Lett. B PD FEB 19 PY 1998 VL 420 IS 1-2 BP 1 EP 7 DI 10.1016/S0370-2693(97)01523-2 PG 7 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA ZH148 UT WOS:000073077600001 ER PT J AU Aharony, O Berkooz, M Kachru, S Silverstein, E AF Aharony, O Berkooz, M Kachru, S Silverstein, E TI Matrix description of (1,0) theories in six dimensions SO PHYSICS LETTERS B LA English DT Article ID STRING DYNAMICS; DUALITY AB We propose descriptions of interacting (1,0) supersymmetric theories without gravity in six dimensions in the infinite momentum frame. They are based on the large N limit of quantum mechanics or 1 + 1 dimensional field theories with SO(N) gauge group and four supercharges. explicitly describe We argue that this formulation allows for a concrete description of the chirality-changing phase transitions which connect (1,0) theories with different numbers of tensor multiplets. (C) 1998 Published by Elsevier Science B.V. C1 Rutgers State Univ, Dept Phys & Astron, Piscataway, NJ 08855 USA. Inst Adv Study, Sch Nat Sci, Princeton, NJ 08540 USA. Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. Stanford Univ, Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. RP Aharony, O (reprint author), Rutgers State Univ, Dept Phys & Astron, POB 849, Piscataway, NJ 08855 USA. NR 41 TC 13 Z9 13 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0370-2693 J9 PHYS LETT B JI Phys. Lett. B PD FEB 19 PY 1998 VL 420 IS 1-2 BP 55 EP 63 DI 10.1016/S0370-2693(97)01503-7 PG 9 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA ZH148 UT WOS:000073077600010 ER PT J AU Hampel, W Heusser, G Kiko, J Kirsten, T Laubenstein, M Pernicka, E Rau, W Ronn, U Schlosser, C Wojcik, M von Ammon, R Ebert, KH Fritsch, T Heidt, D Henrich, E Stieglitz, L Weirich, F Balata, M Hartmann, FX Sann, M Bellotti, E Cattadori, C Cremonesi, O Ferrari, N Fiorini, E Zanotti, L Altmann, M von Feilitzsch, F Mossbauer, R Berthomieu, G Schatzman, E Carmi, I Dostrovsky, I Bacci, C Belli, P Bernabei, R d'Angelo, S Paoluzi, L Bevilacqua, A Cribier, M Gosset, L Rich, J Spiro, M Tao, C Vignaud, D Boger, J Hahn, RL Rowley, JK Stoenner, RW Weneser, J AF Hampel, W Heusser, G Kiko, J Kirsten, T Laubenstein, M Pernicka, E Rau, W Ronn, U Schlosser, C Wojcik, M von Ammon, R Ebert, KH Fritsch, T Heidt, D Henrich, E Stieglitz, L Weirich, F Balata, M Hartmann, FX Sann, M Bellotti, E Cattadori, C Cremonesi, O Ferrari, N Fiorini, E Zanotti, L Altmann, M von Feilitzsch, F Mossbauer, R Berthomieu, G Schatzman, E Carmi, I Dostrovsky, I Bacci, C Belli, P Bernabei, R d'Angelo, S Paoluzi, L Bevilacqua, A Cribier, M Gosset, L Rich, J Spiro, M Tao, C Vignaud, D Boger, J Hahn, RL Rowley, JK Stoenner, RW Weneser, J CA GALLEX Collaboration TI Final results of the Cr-51 neutrino source experiments in GALLEX SO PHYSICS LETTERS B LA English DT Article ID SOLAR MODELS; OSCILLATIONS; LIMITS; SEARCH; HELIOSEISMOLOGY; MUON AB The radiochemical GALLEX experiment, which has been measuring the solar neutrino flux since May 1991, has performed an investigation with two intense Cr-51 neutrino sources (> 60 PBq) that were produced in the Siloe nuclear reactor and used at the Gran Sasso National Laboratory, one between June and October 1994, and the second between October 95 and February 96. The ratio, R, of the the neutrino source strength derived from the measured rate of Ge-71 production, divided by the directly determined source strength is R = 1.01(-0.11)(+0.12) for the first source and R = 0.84(-0.11)(+0.12) for the second one. The combined value of R for the two source experiments is R = 0.93 +/- 0.08. It shows that the > 40% deficit of solar neutrino flux observed by GALLEX cannot be attributed to experimental artifacts and demonstrates the absence of any significant unexpected systematic errors at the 10% level. (C) 1998 Elsevier Science B.V. C1 Max Planck Inst Kernphys, D-69029 Heidelberg, Germany. Forschungszentrum Karlsruhe, Inst Chem Tech, D-76021 Karlsruhe, Germany. INFN, Lab Nazl Gran Sasso, I-67010 Coppito, Italy. Univ Milan, Dipartimento Fis, I-20133 Milan, Italy. INFN, I-20133 Milan, Italy. Tech Univ Munchen, Phys Dept E15, D-85748 Munchen, Germany. Observ Cote Azur, Dept Cassini, F-06004 Nice 4, France. Weizmann Inst Sci, Dept Environm & Energy Res, IL-76100 Rehovot, Israel. Univ Roma Tor Vergata 2, Dipartimento Fis, I-00133 Rome, Italy. INFN, I-00133 Rome, Italy. CEA Saclay, DAPNIA, F-91191 Gif Sur Yvette, France. Brookhaven Natl Lab, Dept Chem, Upton, NY 11973 USA. Jagiellonian Univ, Inst Phys, PL-30059 Krakow, Poland. Observ Paris, DASGAL, F-92195 Meudon, France. Univ Rome 3, Dipartimento Fis, I-00100 Rome, Italy. CEN, SAPR, SRS, F-38041 Grenoble, France. Coll France, LPCC, F-75231 Paris 05, France. RP Hampel, W (reprint author), Max Planck Inst Kernphys, Postfach 103980, D-69029 Heidelberg, Germany. RI Belli, Pierluigi/H-1942-2012; Laubenstein, Matthias/C-4851-2013; Bernabei, Rita/C-1212-2016; OI Belli, Pierluigi/0000-0003-4517-4891; Laubenstein, Matthias/0000-0001-5390-4343; Bernabei, Rita/0000-0003-1786-5396; cattadori, carla maria/0000-0001-7885-6253 NR 31 TC 159 Z9 160 U1 0 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0370-2693 J9 PHYS LETT B JI Phys. Lett. B PD FEB 19 PY 1998 VL 420 IS 1-2 BP 114 EP 126 DI 10.1016/S0370-2693(97)01562-1 PG 13 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA ZH148 UT WOS:000073077600019 ER PT J AU Aggarwal, MM Agnihotri, A Ahammed, Z Angelis, ALS Antonenko, V Arefiev, V Astakhov, V Avdeitchikov, V Awes, TC Baba, PVKS Badyal, SK Baldine, A Barabach, L Barlag, C Bathe, S Batiounia, B Bernier, T Bhalla, KB Bhatia, VS Blume, C Bock, R Bohne, EM Bucher, D Buijs, A Buis, EJ Busching, H Carlen, L Chalyshev, V Chattopadhyay, S Cherbatchev, R Chujo, T Claussen, A Das, AC Decowski, MP Djordjadze, V Donni, P Doubovik, I Majumdar, MRD El Chenawi, K Eliseev, S Enosawa, K Foka, P Fokin, S Frolov, V Ganti, MS Garpman, S Gavrishchuk, O Geurts, FJM Ghosh, TK Glasow, R Gupta, SK Guskov, B Gustafsson, HA Gutbrod, HH Higuchi, R Hrivnacova, I Ippolitov, M Kalechofsky, H Kamermans, R Kampert, KH Karadjev, K Karpio, K Kato, S Kees, S Kim, H Kolb, BW Kosarev, I Koutcheryaev, I Kugler, A Kulinich, P Kumar, V Kurata, M Kurita, K Kuzmin, N Langbein, I Lebedev, A Lee, YY Lohner, H Luquin, L Mahapatra, DP Manko, V Martin, M Maximov, A Mehdiyev, R Mgebrichvili, G Miake, Y Mikhalev, D Mishra, GC Miyamoto, Y Morrison, D Mukhopadhyay, DS Myalkovski, V Naef, H Nandi, BK Nayak, SK Nayak, TK Neumaier, S Nianine, A Nikitine, V Nikolaev, S Nishimura, S Nomokonov, P Nystrand, J Obenshain, FE Oskarsson, A Otterlund, I Pachr, M Parfenov, A Pavliouk, S Pietzmann, T Petracek, V Plasil, F Purschke, ML Raeven, B Rak, J Raniwala, S Ramamurthy, VS Rao, NK Retiere, F Reygers, K Roland, G Rosselet, L Roufanov, I Roy, C Rubio, JM Sako, H Sambyal, SS Santo, R Sato, S Schlagheck, H Schmidt, HR Shabratova, G Sibiriak, I Siemiarczuk, T Sinha, BC Slavine, N Soderstrom, K Solomey, N Sorensen, SP Stankus, P Stefanek, G Steinberg, P Stenlund, E Stuken, D Sumbera, M Svensson, T Trivedi, MD Tsvetkov, A Twenhofel, C Tykarski, L Urbahn, J von Eijndhoven, N von Heeringen, WH von Nieuwenhuizen, GJ Vinogradov, A Viyogi, YP Vodopianov, A Voros, S Vos, MA Wyslouch, B Yagi, K Yokota, Y Young, GR AF Aggarwal, MM Agnihotri, A Ahammed, Z Angelis, ALS Antonenko, V Arefiev, V Astakhov, V Avdeitchikov, V Awes, TC Baba, PVKS Badyal, SK Baldine, A Barabach, L Barlag, C Bathe, S Batiounia, B Bernier, T Bhalla, KB Bhatia, VS Blume, C Bock, R Bohne, EM Bucher, D Buijs, A Buis, EJ Busching, H Carlen, L Chalyshev, V Chattopadhyay, S Cherbatchev, R Chujo, T Claussen, A Das, AC Decowski, MP Djordjadze, V Donni, P Doubovik, I Majumdar, MRD El Chenawi, K Eliseev, S Enosawa, K Foka, P Fokin, S Frolov, V Ganti, MS Garpman, S Gavrishchuk, O Geurts, FJM Ghosh, TK Glasow, R Gupta, SK Guskov, B Gustafsson, HA Gutbrod, HH Higuchi, R Hrivnacova, I Ippolitov, M Kalechofsky, H Kamermans, R Kampert, KH Karadjev, K Karpio, K Kato, S Kees, S Kim, H Kolb, BW Kosarev, I Koutcheryaev, I Kugler, A Kulinich, P Kumar, V Kurata, M Kurita, K Kuzmin, N Langbein, I Lebedev, A Lee, YY Lohner, H Luquin, L Mahapatra, DP Manko, V Martin, M Maximov, A Mehdiyev, R Mgebrichvili, G Miake, Y Mikhalev, D Mishra, GC Miyamoto, Y Morrison, D Mukhopadhyay, DS Myalkovski, V Naef, H Nandi, BK Nayak, SK Nayak, TK Neumaier, S Nianine, A Nikitine, V Nikolaev, S Nishimura, S Nomokonov, P Nystrand, J Obenshain, FE Oskarsson, A Otterlund, I Pachr, M Parfenov, A Pavliouk, S Pietzmann, T Petracek, V Plasil, F Purschke, ML Raeven, B Rak, J Raniwala, S Ramamurthy, VS Rao, NK Retiere, F Reygers, K Roland, G Rosselet, L Roufanov, I Roy, C Rubio, JM Sako, H Sambyal, SS Santo, R Sato, S Schlagheck, H Schmidt, HR Shabratova, G Sibiriak, I Siemiarczuk, T Sinha, BC Slavine, N Soderstrom, K Solomey, N Sorensen, SP Stankus, P Stefanek, G Steinberg, P Stenlund, E Stuken, D Sumbera, M Svensson, T Trivedi, MD Tsvetkov, A Twenhofel, C Tykarski, L Urbahn, J von Eijndhoven, N von Heeringen, WH von Nieuwenhuizen, GJ Vinogradov, A Viyogi, YP Vodopianov, A Voros, S Vos, MA Wyslouch, B Yagi, K Yokota, Y Young, GR CA WA98 Collaboration TI Search for disoriented chiral condensates in 158 AGeV Pb+Pb collisions SO PHYSICS LETTERS B LA English DT Article ID PHASE-TRANSITION; ENERGY; DETECTOR; CERN; QCD AB The restoration of chiral symmetry and its subsequent breaking through a phase transition has been predicted to create regions of Disoriented Chiral Condensates (DCC). This phenomenon has been predicted to cause anomalous fluctuations in th; relative production of charged and neutral plans in high-energy hadronic and nuclear collisions. The WA98 experiment has been used to measure charged and photon multiplicities in the central region of 158 AGeV Pb + Pb collisions at the CERN SPS. In a sample of 212646 events, no clear DCC signal can be distinguished. Using a simple DCC model. we have set a 90% C.L. upper limit on the maximum DCC production allowed by the data. (C) 1998 Elsevier Science B.V. C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. Panjab Univ, Chandigarh 160014, India. Univ Rajasthan, Jaipur 302004, Rajasthan, India. Ctr Variable Energy Cyclotron, Calcutta 700064, W Bengal, India. Univ Geneva, CH-1211 Geneva 4, Switzerland. RRC Kurchatov, RU-123182 Moscow, Russia. Joint Nucl Res Inst, RU-141980 Dubna, Russia. Univ Jammu, Jammu 180001, India. Univ Munster, D-48149 Munster, Germany. Ecole Mines, SUBATECH, Nantes, France. Gesell Schwerionenforsch GmbH, D-64220 Darmstadt, Germany. Univ Utrecht, NIKHEF, NL-3508 TA Utrecht, Netherlands. Univ Lund, SE-22100 Lund, Sweden. Univ Tsukuba, Ibaraki, Osaka 305, Japan. Inst Nucl Phys, CZ-25068 Rez, Czech Republic. Univ Groningen, KVI, NL-9747 AA Groningen, Netherlands. Inst Nucl Studies, PL-00681 Warsaw, Poland. MIT, Cambridge, MA 02139 USA. Inst Phys, Bhubaneswar 751005, Orissa, India. Univ Tennessee, Knoxville, TN 37966 USA. RP Aggarwal, MM (reprint author), Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RI Decowski, Patrick/A-4341-2011; Mehdiyev, Rashid/H-6299-2013; Lohner, Herbert/B-2397-2014; Sumbera, Michal/O-7497-2014; OI Lohner, Herbert/0000-0002-7441-739X; Sumbera, Michal/0000-0002-0639-7323; Kampert, Karl-Heinz/0000-0002-2805-0195 NR 29 TC 58 Z9 58 U1 0 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0370-2693 J9 PHYS LETT B JI Phys. Lett. B PD FEB 19 PY 1998 VL 420 IS 1-2 BP 169 EP 179 DI 10.1016/S0370-2693(97)01528-1 PG 11 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA ZH148 UT WOS:000073077600023 ER PT J AU Ganguli, AK Corbett, JD Kockerling, M AF Ganguli, AK Corbett, JD Kockerling, M TI Mixed cations for the stabilization of new features. Ca6.2Mg3.8Sn7, a phase with planar zigzag chains of interlinked square-planar tin units SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Article ID ZINTL-PHASES; CHEMISTRY; SYSTEMS AB The structure of orthorhombic Ca-6.24(6)Mg-3.76(6)Sn-7 contains two types of chains built from edge- or face-sharing trigonal prisms of Ca and Mg atoms that are centered by Sn atoms. In one type, bonded zigzag (1)(infinity)[Sn-5(12-)] chains are built of interconnected square-planar (D-2h) Sn-5 units. Alternating chains of condensed trigonal prismatic cations centered by isolated Sn atoms are interbonded to the first type through Sn-Ca,Mg interactions. The chain unit is two electrons richer than that for a simple Zintl-Klemm formalism for 1-, 2-, and 4-bonded Sn (4b-Sn-0) because of the square-planar tin bonding. Band structure calculations within the extended Huckel formalism indicate the infinite tin chain alone is closed shell, but a metallic behavior (via open pi-bonding) is produced by cation mixing in the full structure. Local bonding within square-planar Sn-5 consists of normal s, p(x), p(y) (sigma) bonding, a single 4c-2e nonbonding MO on the outer tins, and a p(z)(2) lone (pi) pair. This new intermediate degree of hypervalency makes the unit isoelectronic with XeF42+. Property studies on powdered samples reveal a good metallic conduction but a small diamagnetism that is not uncharacteristic of heavy p-elements and their compounds. C1 Iowa State Univ Sci & Technol, Ames Lab, US DOE, Ames, IA 50011 USA. Iowa State Univ Sci & Technol, Dept Chem, Ames, IA 50011 USA. Gerhard Mercator Univ, FB Festkorperchem 6, D-47057 Duisburg, Germany. Indian Inst Technol, Dept Chem, New Delhi 110016, India. RP Corbett, JD (reprint author), Iowa State Univ Sci & Technol, Ames Lab, US DOE, Ames, IA 50011 USA. NR 35 TC 28 Z9 29 U1 0 U2 0 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 FEB 18 PY 1998 VL 120 IS 6 BP 1223 EP 1229 DI 10.1021/ja972812+ PG 7 WC Chemistry, Multidisciplinary SC Chemistry GA YY185 UT WOS:000072121800015 ER PT J AU George, GN Colangelo, CM Dong, J Scott, RA Khangulov, SV Gladyshev, VN Stadtman, TC AF George, GN Colangelo, CM Dong, J Scott, RA Khangulov, SV Gladyshev, VN Stadtman, TC TI X-ray absorption spectroscopy of the molybdenum site of Escherichia coli formate dehydrogenase SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Article ID DIMETHYL-SULFOXIDE REDUCTASE; BOND-VALENCE PARAMETERS; XANTHINE-OXIDASE; CRYSTAL-STRUCTURE; RHODOBACTER-SPHAEROIDES; NUCLEOTIDE-SEQUENCE; SULFITE OXIDASE; HYDROGEN-LYASE; FINE-STRUCTURE; COMPLEXES AB X-ray absorption spectroscopy at the molybdenum and selenium K-edges has been used to probe the active site structure of Escherichia coli formate dehydrogenase H. The active sites of both oxidized and reduced wild-type protein, and of a variant containing cysteine instead of selenocysteine, were studied. The oxidized and reduced enzymes were found to be very similar, both containing a novel des-oxo molybdenum site, with four Mo-S ligands at 2.35 Angstrom, (probably) one Mo-O at 2.1 Angstrom, and one Mo-Se ligand at 2.62 Angstrom being indicated from the Mo K-edge data. The selenium K-edge EXAFS not only is in good agreement with the Mo K-edge data but also indicates the unexpected presence of Se-S ligation, with a bond length of 2.19 Angstrom. We suggest that the active site of Escherichia coli formate dehydrogenase H contains a novel selenosulfide ligand to molybdenum, where the selenium and sulfur originate from selenocysteine and one of the pterin-cofactor dithiolenes, respectively. C1 Stanford Univ, SLAC, Stanford Synchrotron Radiat Lab, Stanford, CA 94309 USA. Univ Georgia, Ctr Metalloenzyme Studies, Athens, GA 30602 USA. Univ Georgia, Dept Chem, Athens, GA 30602 USA. NIH, Bethesda, MD 20892 USA. RP George, GN (reprint author), Stanford Univ, SLAC, Stanford Synchrotron Radiat Lab, POB 4349,MS 69, Stanford, CA 94309 USA. RI Gladyshev, Vadim/A-9894-2013; George, Graham/E-3290-2013; OI Colangelo, Christopher/0000-0002-0438-1395 NR 50 TC 59 Z9 59 U1 2 U2 8 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 FEB 18 PY 1998 VL 120 IS 6 BP 1267 EP 1273 DI 10.1021/ja973004l PG 7 WC Chemistry, Multidisciplinary SC Chemistry GA YY185 UT WOS:000072121800020 ER PT J AU Young, DM Geiser, U Schultz, AJ Wang, HH AF Young, DM Geiser, U Schultz, AJ Wang, HH TI Hydrothermal synthesis of a dense metal-organic layered framework that contains Cu(I)-olefinic bonds, Cn(2)(O2CCH = CHCO2) SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Article ID COORDINATION NETWORK; CRYSTAL-STRUCTURE; CARBON-MONOXIDE; COPPER(I); CHANNELS; COMPLEXES C1 Argonne Natl Lab, Div Chem, Argonne, IL 60439 USA. Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. RP Schultz, AJ (reprint author), Argonne Natl Lab, Div Chem, 9700 S Cass Ave, Argonne, IL 60439 USA. NR 28 TC 60 Z9 61 U1 1 U2 19 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 FEB 18 PY 1998 VL 120 IS 6 BP 1331 EP 1332 DI 10.1021/ja973483o PG 2 WC Chemistry, Multidisciplinary SC Chemistry GA YY185 UT WOS:000072121800030 ER PT J AU Durbin, MK Malik, A Richter, AG Yu, CJ Eisenhower, R Dutta, P AF Durbin, MK Malik, A Richter, AG Yu, CJ Eisenhower, R Dutta, P TI Ordered phases in Langmuir monolayers of an azobenzene derivative SO LANGMUIR LA English DT Article ID X-RAY-DIFFRACTION; CHAIN FATTY-ACIDS; CRYSTAL-STRUCTURE; CONTAINING AMPHIPHILES; MOLECULAR-ORIENTATION; BARIUM SALTS; FILMS; BILAYER; GRAPHITE AB We have performed grazing incidence X-ray diffraction studies of Langmuir monolayers of an azobenzene derivative. There are only two phases over a range of temperatures and pressures in which at least seven phases exist in monolayers of simpler molecules (0-30 degrees C, 0-40 dyn/cm). The low-pressure phase has tilt toward a nearest neighbor, while the high-pressure phase has tilt toward a next-nearest neighbor. Within each phase the tilt angle does not change significantly wit h pressure. This behavior is very different from that of monolayers with saturated hydrocarbon tails and implies that the azobenzene groups 'lock' and prevent the molecules from sliding against each other. However, the lattice parameters change with pressure; this suggests that the molecular conformation changes. The structure of the low-pressure phase is similar to one observed in ate-derivative bilayer membranes and crystals, while the high pressure phase has a structure not seen before in such systems. C1 Northwestern Univ, Dept Phys & Astron, Evanston, IL 60206 USA. Oak Ridge Natl Lab, Div Met & Ceram, Oak Ridge, TN 37830 USA. RP Durbin, MK (reprint author), Northwestern Univ, Dept Phys & Astron, Evanston, IL 60206 USA. NR 25 TC 24 Z9 24 U1 0 U2 4 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0743-7463 J9 LANGMUIR JI Langmuir PD FEB 17 PY 1998 VL 14 IS 4 BP 899 EP 903 DI 10.1021/la9710334 PG 5 WC Chemistry, Multidisciplinary; Chemistry, Physical; Materials Science, Multidisciplinary SC Chemistry; Materials Science GA YY251 UT WOS:000072128400031 ER PT J AU Pande, VS Rokhsar, DS AF Pande, VS Rokhsar, DS TI Is the molten globule a third phase of proteins? SO PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA LA English DT Article ID CRYSTAL-STRUCTURES; BUNDLE PROTEIN; STATE; SIMULATIONS; MODELS; HETEROPOLYMERS; TRANSITION; PRINCIPLES; MOLECULES; DIAGRAM AB The equilibrium properties of proteins are studied by Monte Carlo simulation of two simplified models of protein-like heteropolymers. These models emphasize the polymeric entropy of the fluctuating polypeptide chain, Our calculations suggest a generic phase diagram that contains a thermodynamically distinct "molten globule" state in addition to a rigid native state and a nontrivial unfolded state. The roles of side-chain packing and loop entropy are discussed. C1 Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. Lawrence Berkeley Lab, Phys Biosci Sci Div, Berkeley, CA 94720 USA. RP Rokhsar, DS (reprint author), Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. NR 35 TC 73 Z9 73 U1 0 U2 2 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 FEB 17 PY 1998 VL 95 IS 4 BP 1490 EP 1494 DI 10.1073/pnas.95.4.1490 PG 5 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA YY126 UT WOS:000072115900025 PM 9465042 ER PT J AU Hummer, G Garde, S Garcia, AE Paulaitis, ME Pratt, LR AF Hummer, G Garde, S Garcia, AE Paulaitis, ME Pratt, LR TI The pressure dependence of hydrophobic interactions is consistent with the observed pressure denaturation of proteins SO PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA LA English DT Article DE protein folding; protein folding kinetics; hydrophobic effect; activation volumes; protein unfolding ID EGG-WHITE LYSOZYME; MOLECULAR-DYNAMICS SIMULATION; HYDROSTATIC-PRESSURE; ENTROPY CONVERGENCE; CRYSTAL-STRUCTURE; RIBONUCLEASE-A; LIQUID WATER; FREE-ENERGY; DEEP-SEA; THERMODYNAMICS AB Proteins can be denatured by pressures of a few hundred MPa. This finding apparently contradicts the most widely used model of protein stability, where the formation of a hydrophobic core drives protein folding, The pressure denaturation puzzle is resolved by focusing on the pressure-dependent transfer of water into the protein interior, in contrast to the transfer of nonpolar residues into water, the approach commonly taken in models of protein unfolding, Pressure denaturation of proteins can then be explained by the pressure destabilization of hydrophobic aggregates by using an information theory model of hydrophobic interactions, Pressure-denatured proteins, unlike heat-denatured proteins, retain a compact structure with water molecules penetrating their core, Activation volumes for hydrophobic contributions to protein folding and unfolding kinetics are positive. Clathrate hydrates are predicted to form by virtually the same mechanism that drives pressure denaturation of proteins. C1 Univ Calif Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. Univ Delaware, Dept Chem Engn, Ctr Mol & Engn Thermodynam, Newark, DE 19716 USA. Johns Hopkins Univ, Dept Chem Engn, Baltimore, MD 21218 USA. RP Hummer, G (reprint author), Univ Calif Los Alamos Natl Lab, Div Theoret, MS K710, Los Alamos, NM 87545 USA. RI Garde, Shekhar/C-3060-2008; Pratt, Lawrence/H-7955-2012; Hummer, Gerhard/A-2546-2013 OI Pratt, Lawrence/0000-0003-2351-7451; Hummer, Gerhard/0000-0001-7768-746X NR 66 TC 434 Z9 438 U1 12 U2 80 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 FEB 17 PY 1998 VL 95 IS 4 BP 1552 EP 1555 DI 10.1073/pnas.95.4.1552 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA YY126 UT WOS:000072115900036 PM 9465053 ER PT J AU Zhou, JP McDevitt, JT Jia, QX AF Zhou, JP McDevitt, JT Jia, QX TI Improved N-layer materials for high-T-c superconductor/normal-metal/superconductor junctions and superconducting quantum interference device sensors SO APPLIED PHYSICS LETTERS LA English DT Article ID EDGE JUNCTIONS; SQUIDS; YBA2CU3O7-DELTA; BARRIERS AB In order to solve some of the formidable problems related to producing reliable and reproducible cuprate superconductor/normal-metal/superconductor (SNS) junctions, new N-layer compounds from the family of R1-xCaxBa2-yLayCu3-zMzO7-delta (R = Y, Gd and Pr; M = Co, Ni and Zn; 0 less than or equal to x less than or equal to 0.4; 0 less than or equal to y less than or equal to 0.4; 0 less than or equal to z less than or equal to 0.4) have been synthesized and their properties characterized. Thus, a crystal engineering approach has been adopted in an effort to generate reliable materials for use in high T-c superconducting devices. Careful analyses of the various prepared phases reveal optimum substitution levels for selected compositions where the N-layer compounds exhibit structures compatible with common superconductor electrode materials. The new compounds have been used for demonstration purposes as the N-layer material for the construction of ramp-edge-geometry SNS junctions and superconducting quantum interference device sensors. (C) 1998 American Institute of Physics. C1 Univ Texas, Dept Chem & Biochem, Austin, TX 78712 USA. Univ Calif Los Alamos Natl Lab, Superconduct Technol Ctr, Los Alamos, NM 87545 USA. RP Zhou, JP (reprint author), Univ Texas, Dept Chem & Biochem, Austin, TX 78712 USA. EM mcdevitt@huckel.cm.utexas.edu RI Jia, Q. X./C-5194-2008; McDevitt, John/P-4108-2014 OI McDevitt, John/0000-0001-8789-9351 NR 13 TC 7 Z9 7 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 FEB 16 PY 1998 VL 72 IS 7 BP 848 EP 850 DI 10.1063/1.120913 PG 3 WC Physics, Applied SC Physics GA ZH583 UT WOS:000073126000033 ER PT J AU Kwiatkowski, K Hsi, WC Viola, VE Wang, G Bracken, DS Breuer, H Cornell, E Foxford, ER Gimeno-Nogues, F Ginger, DS Gushue, S Korteling, RG Lynch, WG Morley, KB Pollacco, EC Ramakrishnan, E Remsberg, LP Tsang, MB Volant, C Yennello, SJ Xi, H Yoder, NR AF Kwiatkowski, K Hsi, WC Viola, VE Wang, G Bracken, DS Breuer, H Cornell, E Foxford, ER Gimeno-Nogues, F Ginger, DS Gushue, S Korteling, RG Lynch, WG Morley, KB Pollacco, EC Ramakrishnan, E Remsberg, LP Tsang, MB Volant, C Yennello, SJ Xi, H Yoder, NR CA ISiS Collaboration TI Multifragmentation: thermal vs. dynamic effects SO NUCLEAR PHYSICS A LA English DT Article; Proceedings Paper CT 6th International Conference on Nucleus-Nucleus Collisions CY JUN 02-06, 1997 CL GATLINBURG, TENNESSEE SP US DOE, US Natl Sci Fdn, Oak Ridge Natl Lab, Michigan State Univ, Natl Superconducting Cyclotron Lab ID INTRANUCLEAR CASCADE CALCULATION; HEAVY-ION COLLISIONS; HE-3+ AG-NAT; AU-197 REACTIONS; HIGH-ENERGY; 4-PI; NUCLEI AB Reactions of 1.8 - 4.8 GeV He-3, 5.0 - 9.2 GeV/c pi(-) and 6.0 - 14.6 GeV/c protons with Ag-nat and Au-197 targets have been studied with the ISiS 4 pi detector array. From reconstructed events, excitation-energy distributions have been determined and combined with a H-2,H-3/He-3,He-4 isotope-ratio thermometer to study the heating curve for the thermal-like component of these reactions. Dynamic effects also manifest themselves in the data, as evidenced by deposition-energy saturation above similar to 5 GeV, IMF emission during expansion,and sideways peaking of the IMF angular distributions for beam energies E-b greater than or equal to 10 GeV. C1 Indiana Univ, Bloomington, IN 47405 USA. Simon Fraser Univ, Burnaby, BC V5A 1S6, Canada. CE Saclay, SPHN, DAPNIA, F-91191 Gif Sur Yvette, France. Texas A&M Univ, College Stn, TX 77843 USA. Michigan State Univ, E Lansing, MI 48824 USA. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Univ Maryland, College Pk, MD 20742 USA. Brookhaven Natl Lab, Upton, NY 11973 USA. RP Kwiatkowski, K (reprint author), Indiana Univ, Bloomington, IN 47405 USA. RI Ginger, David/C-4866-2011; Lynch, William/I-1447-2013; Yennello, Sherry/B-5803-2015 OI Ginger, David/0000-0002-9759-5447; Lynch, William/0000-0003-4503-176X; Yennello, Sherry/0000-0003-3963-5217 NR 23 TC 4 Z9 4 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0375-9474 J9 NUCL PHYS A JI Nucl. Phys. A PD FEB 16 PY 1998 VL 630 IS 1-2 BP 168C EP 175C PG 8 WC Physics, Nuclear SC Physics GA ZG938 UT WOS:000073055100016 ER PT J AU Ohnishi, A Randrup, J Hirata, Y Otuka, N Nara, Y Harada, T AF Ohnishi, A Randrup, J Hirata, Y Otuka, N Nara, Y Harada, T TI Quantum fluctuation effects on nuclear and atomic cluster formation SO NUCLEAR PHYSICS A LA English DT Article; Proceedings Paper CT 6th International Conference on Nucleus-Nucleus Collisions CY JUN 02-06, 1997 CL GATLINBURG, TENNESSEE SP US DOE, US Natl Sci Fdn, Oak Ridge Natl Lab, Michigan State Univ, Natl Superconducting Cyclotron Lab ID ANTISYMMETRIZED MOLECULAR-DYNAMICS; 2-NUCLEON COLLISIONS; VERSION AB The effects of quantum fluctuations on various fragmentation reactions, from the production of intermediate mass fragments in Au+Au collisions to atomic cluster formation, are studied by using the recently developed Quantal Langevin mode!. The larger fluctuations and the intrinsic distortion enhances fragments with low excitation energies. The fragmentation patterns in quantal and classical simulations are discussed in terms of an effective classical temperature. C1 Hokkaido Univ, Dept Phys, Sapporo, Hokkaido 060, Japan. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Nucl Sci, Berkeley, CA 94720 USA. Japan Atom Energy Res Inst, Adv Sci Res Ctr, Tokai, Ibaraki 31911, Japan. Sapporo Gakuin Univ, Dept Social Informat, Ebetsu, Hokkaido 069, Japan. RP Ohnishi, A (reprint author), Hokkaido Univ, Dept Phys, Sapporo, Hokkaido 060, Japan. RI Ohnishi, Akira/F-7403-2011 OI Ohnishi, Akira/0000-0003-1513-0468 NR 18 TC 0 Z9 0 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0375-9474 J9 NUCL PHYS A JI Nucl. Phys. A PD FEB 16 PY 1998 VL 630 IS 1-2 BP 223C EP 230C PG 8 WC Physics, Nuclear SC Physics GA ZG938 UT WOS:000073055100023 ER PT J AU Nazarewicz, W AF Nazarewicz, W TI Frontiers of nuclear structure SO NUCLEAR PHYSICS A LA English DT Article; Proceedings Paper CT 6th International Conference on Nucleus-Nucleus Collisions CY JUN 02-06, 1997 CL GATLINBURG, TN SP US DOE, US Natl Sci Fdn, Oak Ridge Natl Lab, Michigan State Univ, Natl Superconducting Cyclotron Lab ID SUPERDEFORMED ROTATIONAL BANDS; IDENTICAL BANDS; SHELL-MODEL; MEAN-FIELD; SUPERHEAVY NUCLEI; ISOTOPE SHIFTS; GROUND-STATE; MONTE-CARLO; MASS REGION; DRIP-LINE AB Current developments in nuclear structure at the "limits" are discussed. The studies of nuclear behavior at extreme conditions provide us with invaluable information about, the nature of the nuclear interaction and nucleonic correlations at various energy-distance scales. In this talk, frontiers of nuclear structure are briefly reviewed from a theoretical perspective, mainly concentrating on medium-mass and heavy nuclei. C1 Univ Tennessee, Dept Phys, Knoxville, TN 37996 USA. Oak Ridge Natl Lab, Div Phys, Oak Ridge, TN 37831 USA. Univ Warsaw, Inst Theoret Phys, PL-00681 Warsaw, Poland. RP Nazarewicz, W (reprint author), Univ Tennessee, Dept Phys, Knoxville, TN 37996 USA. NR 103 TC 6 Z9 6 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0375-9474 J9 NUCL PHYS A JI Nucl. Phys. A PD FEB 16 PY 1998 VL 630 IS 1-2 BP 239C EP 256C PG 18 WC Physics, Nuclear SC Physics GA ZG938 UT WOS:000073055100025 ER PT J AU Fallon, P AF Fallon, P TI A new spin on high spin SO NUCLEAR PHYSICS A LA English DT Article; Proceedings Paper CT 6th International Conference on Nucleus-Nucleus Collisions CY JUN 02-06, 1997 CL GATLINBURG, TENNESSEE SP US DOE, US Natl Sci Fdn, Oak Ridge Natl Lab, Michigan State Univ, Natl Superconducting Cyclotron Lab ID SUPERDEFORMED BANDS; C-4 SYMMETRY; NUCLEI; ALIGNMENT C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Fallon, P (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, 1 Cyclotron Rd, Berkeley, CA 94720 USA. NR 28 TC 0 Z9 0 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0375-9474 J9 NUCL PHYS A JI Nucl. Phys. A PD FEB 16 PY 1998 VL 630 IS 1-2 BP 257C EP 267C PG 11 WC Physics, Nuclear SC Physics GA ZG938 UT WOS:000073055100026 ER PT J AU Rykaczewski, K Grzywacz, R Lewitowicz, M Pfutzner, M AF Rykaczewski, K Grzywacz, R Lewitowicz, M Pfutzner, M TI New mu s-isomers and isomeric beams SO NUCLEAR PHYSICS A LA English DT Article; Proceedings Paper CT 6th International Conference on Nucleus-Nucleus Collisions CY JUN 02-06, 1997 CL GATLINBURG, TN SP US DOE, US Natl Sci Fdn, Oak Ridge Natl Lab, Michigan State Univ, Natl Superconducting Cyclotron Lab AB A review of experimental results obtained within the last three years on mu s-isomeric states produced in fragmentation reactions and studied at projectile fragment separators at GANIL Caen and GSI Darmstadt is given. Experiments based on secondary reactions with isomeric beams are discussed. C1 Oak Ridge Natl Lab, Oak Ridge, TN 37830 USA. Univ Warsaw, Inst Expt Phys, PL-00681 Warsaw, Poland. GANIL, F-14021 Caen, France. Gesell Schwerionenforsch mbH, D-64220 Darmstadt, Germany. RP Rykaczewski, K (reprint author), Oak Ridge Natl Lab, Oak Ridge, TN 37830 USA. NR 44 TC 5 Z9 5 U1 1 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0375-9474 J9 NUCL PHYS A JI Nucl. Phys. A PD FEB 16 PY 1998 VL 630 IS 1-2 BP 307C EP 315C PG 9 WC Physics, Nuclear SC Physics GA ZG938 UT WOS:000073055100031 ER PT J AU Davids, CN AF Davids, CN TI Nuclear structure information derived from proton radioactivity measurements SO NUCLEAR PHYSICS A LA English DT Article; Proceedings Paper CT 6th International Conference on Nucleus-Nucleus Collisions CY JUN 02-06, 1997 CL GATLINBURG, TENNESSEE SP US DOE, US Natl Sci Fdn, Oak Ridge Natl Lab, Michigan State Univ, Natl Superconducting Cyclotron Lab AB Recent results on proton radioactivity are described. Nuclear structure information such as spins, single particle orbital orderings: spectroscopic factors: and mass excesses have been obtained for a number of spherical proton emitters. New results on deformed proton emitters are discussed. C1 Argonne Natl Lab, Div Phys, Argonne, IL 60439 USA. RP Davids, CN (reprint author), Argonne Natl Lab, Div Phys, Argonne, IL 60439 USA. NR 6 TC 0 Z9 0 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0375-9474 J9 NUCL PHYS A JI Nucl. Phys. A PD FEB 16 PY 1998 VL 630 IS 1-2 BP 321C EP 327C PG 7 WC Physics, Nuclear SC Physics GA ZG938 UT WOS:000073055100033 ER EF