FN Thomson Reuters Web of Science™ VR 1.0 PT J AU Ackerstaff, K Airapetian, A Akopov, N Amarian, M Aschenauer, EC Avakian, H Avakian, R Avetissian, A Bains, B Beckmann, M Belostotski, S Belz, JE Benisch, T Bernreuther, S Bianchi, N Blanchard, S Blouw, J Bottcher, H Borissov, A Brack, J Bray, B Bruckner, W Brull, A Bruins, EEW Bulten, HJ Capitani, GP Carter, P Cisbani, E Court, GR Delheij, PPJ De Sanctis, E De Schepper, D Devitsin, E Huberts, PKAD Duren, M Dvoredsky, A Elbakian, G Emerson, J Fantoni, A Fechtchenko, A Ferstl, M Fiedler, K Filippone, BW Fischer, H Fox, B Franz, J Frullani, S Funk, MA Garber, Y Gagunashvili, ND Galumian, P Gao, H Garibaldi, F Gavrilov, G Geiger, P Gharibyan, V Golendukhin, A Graw, G Grebeniouk, O Green, PY Greeniaus, LG Grosshauser, C Gute, A Gyurjyan, V Haas, JP Haeberli, W Hausser, O Hansen, JO Hasch, D Henderson, R Henkes, T Hertenberger, R Holler, Y Holt, RJ Ihssen, H Iodice, M Izotov, A Jackson, HE Jgoun, A Jones, C Kaiser, R Kinney, E Kirsch, M Kisselev, A Kitching, P Konigsmann, K Kolstein, M Kolster, H Korsch, W Kozlov, V Kramer, LH Krause, B Krivokhijine, VG Kuckes, M Kyle, G Lachnit, W Lorenzon, W Lung, A Makins, NCR Manaenkov, SI Martens, FK Martin, JW Mateos, A McIlhany, K McKeown, RD Meissner, F Menden, F Mercer, D Metz, A Meyners, N Mikloukho, B Miller, CA Miller, MA Milner, R Mitsyn, V Most, A Mozzetti, R Muccifora, V Nagaitsev, A Naryshkin, Y Nathan, AM Neunreither, F Niczyporuk, JM Nowak, WD Nupieri, M Oelwein, P Ogami, H O'Neill, TG Openshaw, R Ouyang, J Pate, SF Pitt, M Poolman, HR Potashov, S Potterveld, DH Rakness, G Redwine, R Reolon, AR Ristinen, R Rith, K Roper, G Roloff, HO Rossi, P Ruh, M Ryckbosch, D Sakemi, Y Savin, I Schuler, KP Schwind, A Shibata, TA Shin, T Simon, A Sinram, K Smythe, WR Sowinski, J Spengos, M Steffens, E Stenger, J Stewart, J Stock, F Stosslein, U Sutter, M Tallini, H Taroian, S Terkulov, A Thiessen, DM Tipton, B Trudel, A Tytgat, M Urciuoli, GM van den Brand, JFJ van der Steenhoven, G van de Vyver, R Vetterli, MC Vincter, MG Volk, E Wander, W Welch, TP Williamson, SE Wise, T Zapfe, K Zohrabian, H AF Ackerstaff, K Airapetian, A Akopov, N Amarian, M Aschenauer, EC Avakian, H Avakian, R Avetissian, A Bains, B Beckmann, M Belostotski, S Belz, JE Benisch, T Bernreuther, S Bianchi, N Blanchard, S Blouw, J Bottcher, H Borissov, A Brack, J Bray, B Bruckner, W Brull, A Bruins, EEW Bulten, HJ Capitani, GP Carter, P Cisbani, E Court, GR Delheij, PPJ De Sanctis, E De Schepper, D Devitsin, E Huberts, PKAD Duren, M Dvoredsky, A Elbakian, G Emerson, J Fantoni, A Fechtchenko, A Ferstl, M Fiedler, K Filippone, BW Fischer, H Fox, B Franz, J Frullani, S Funk, MA Garber, Y Gagunashvili, ND Galumian, P Gao, H Garibaldi, F Gavrilov, G Geiger, P Gharibyan, V Golendukhin, A Graw, G Grebeniouk, O Green, PY Greeniaus, LG Grosshauser, C Gute, A Gyurjyan, V Haas, JP Haeberli, W Hausser, O Hansen, JO Hasch, D Henderson, R Henkes, T Hertenberger, R Holler, Y Holt, RJ Ihssen, H Iodice, M Izotov, A Jackson, HE Jgoun, A Jones, C Kaiser, R Kinney, E Kirsch, M Kisselev, A Kitching, P Konigsmann, K Kolstein, M Kolster, H Korsch, W Kozlov, V Kramer, LH Krause, B Krivokhijine, VG Kuckes, M Kyle, G Lachnit, W Lorenzon, W Lung, A Makins, NCR Manaenkov, SI Martens, FK Martin, JW Mateos, A McIlhany, K McKeown, RD Meissner, F Menden, F Mercer, D Metz, A Meyners, N Mikloukho, B Miller, CA Miller, MA Milner, R Mitsyn, V Most, A Mozzetti, R Muccifora, V Nagaitsev, A Naryshkin, Y Nathan, AM Neunreither, F Niczyporuk, JM Nowak, WD Nupieri, M Oelwein, P Ogami, H O'Neill, TG Openshaw, R Ouyang, J Pate, SF Pitt, M Poolman, HR Potashov, S Potterveld, DH Rakness, G Redwine, R Reolon, AR Ristinen, R Rith, K Roper, G Roloff, HO Rossi, P Ruh, M Ryckbosch, D Sakemi, Y Savin, I Schuler, KP Schwind, A Shibata, TA Shin, T Simon, A Sinram, K Smythe, WR Sowinski, J Spengos, M Steffens, E Stenger, J Stewart, J Stock, F Stosslein, U Sutter, M Tallini, H Taroian, S Terkulov, A Thiessen, DM Tipton, B Trudel, A Tytgat, M Urciuoli, GM van den Brand, JFJ van der Steenhoven, G van de Vyver, R Vetterli, MC Vincter, MG Volk, E Wander, W Welch, TP Williamson, SE Wise, T Zapfe, K Zohrabian, H CA HERMES Collaboration TI Measurement of angular distributions and R = sigma(L)/sigma(T) in diffractive electroproduction of p(0) mesons SO EUROPEAN PHYSICAL JOURNAL C LA English DT Article ID MUON-PROTON-SCATTERING; VECTOR-MESONS; EXCLUSIVE ELECTROPRODUCTION; PHI ELECTROPRODUCTION; HIGH-ENERGIES; QCD; LEPTOPRODUCTION; PHOTONS; NUCLEON; RHO(0) AB Production and decay angular distributions were extracted from measurements of exclusive electroproduction of the rho (0)(770) meson over a range in the virtual photon negative four-momentum squared 0.5 < Q(2) < 4 GeV2 and the photon-nucleon invariant mass range 3.8 < W < 6.5 GeV. The experiment was performed with the HERMES spectrometer, using a longitudinally polarized positron beam and a He-3 gas target internal to the HERA e(+/-) storage ring. The event sample combines rho (0) masons produced incoherently off individual nucleons and coherently off the nucleus as a whole. The distributions in one production angle and two angles describing the rho (0) --> pi (+)pi (-) decay yielded measurements of eight elements of the spin-density matrix, including one that had not been measured before. The results are consistent with the dominance of helicity conserving amplitudes and natural parity exchange. The improved precision achieved at 4 < W < 7 GeV, in combination with other data at W > 7 GeV, reveals evidence for an energy dependence in the ratio R of the longitudinal to transverse cross sections at constant Q(2). C1 DESY, D-22603 Hamburg, Germany. Univ Alberta, Dept Phys, Edmonton, AB T6G 2J1, Canada. Argonne Natl Lab, Div Phys, Argonne, IL 60439 USA. CALTECH, WK Kellogg Radiat Lab, Pasadena, CA 91125 USA. Univ Colorado, Nucl Phys Lab, Boulder, CO 80309 USA. DESY, D-15738 Zeuthen, Germany. Joint Inst Nucl Res, Dubna 141980, Russia. Univ Erlangen Nurnberg, Inst Phys, D-91058 Erlangen, Germany. Ist Nazl Fis Nucl, Lab Nazl Frascati, I-00044 Frascati, Italy. Florida Int Univ, Dept Phys, Miami, FL 33199 USA. Univ Freiburg, Fak Phys, D-79104 Freiburg, Germany. Univ Ghent, Dept Subatom & Radiat Phys, B-9000 Ghent, Belgium. Max Planck Inst Kernphys, D-69029 Heidelberg, Germany. Univ Illinois, Dept Phys, Urbana, IL 61801 USA. Univ Kentucky, Dept Phys & Astron, Lexington, KY 40506 USA. Univ Liverpool, Dept Phys, Liverpool L69 7ZE, Merseyside, England. Univ Wisconsin, Dept Phys, Madison, WI 53706 USA. MIT, Nucl Sci Lab, Cambridge, MA 02139 USA. Univ Michigan, Randall Lab Phys, Ann Arbor, MI 48109 USA. PN Lebedev Phys Inst, Moscow 117924, Russia. Univ Munich, Sekt Phys, D-85748 Garching, Germany. New Mexico State Univ, Dept Phys, Las Cruces, NM 88003 USA. NIKHEF H, NL-1009 DB Amsterdam, Netherlands. Univ Oregon, Dept Phys, Eugene, OR 97403 USA. Petersburg Nucl Phys Inst, Gatchina 188350, Russia. Ist Nazl Fis Nucl, Sezione Sanita, I-00161 Rome, Italy. Ist Super Sanita, Phys Lab, I-00161 Rome, Italy. Simon Fraser Univ, Dept Phys, Burnaby, BC V5A 1S6, Canada. TRIUMF, Vancouver, BC V6T 2A3, Canada. Tokyo Inst Technol, Dept Phys, Tokyo 152, Japan. Free Univ Amsterdam, Dept Phys & Astron, NL-1081 HV Amsterdam, Netherlands. Yerevan Phys Inst, Yerevan 375036, Armenia. RP DESY, Notkestr 85, D-22603 Hamburg, Germany. RI Gao, Haiyan/G-2589-2011; Gavrilov, Gennady/C-6260-2013; Holt, Roy/E-5803-2011; Kozlov, Valentin/M-8000-2015; Terkulov, Adel/M-8581-2015; Cisbani, Evaristo/C-9249-2011 OI Cisbani, Evaristo/0000-0002-6774-8473 NR 48 TC 24 Z9 24 U1 1 U2 6 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 DEC PY 2000 VL 18 IS 2 BP 303 EP 316 DI 10.1007/s100520000536 PG 14 WC Physics, Particles & Fields SC Physics GA 392NC UT WOS:000166416700007 ER PT J AU Bearden, IG Boggild, H Boissevain, J Christiansen, PHL Conin, L Dodd, J Erazmus, B Esumi, S Fabjan, CW Ferenc, D Franz, A Gaardhoje, JJ Hansen, AG Hansen, O Hardtke, D van Hecke, H Holzer, EB Humanic, TJ Hummel, P Jacak, BV Kaimi, K Kaneta, M Kohama, T Kopytine, M Leltchouk, M Ljubicic, A Lorstad, B Maeda, N Martin, L Medvedev, A Murray, M Ohnishi, H Paic, G Pandey, SU Piuz, F Pluta, J Polychronakos, V Potekhin, M Poulard, G Reichhold, D Sakaguchi, A Schmidt-Sorensen, J Simon-Gillo, J Sondheim, W Sugitate, T Sullivan, JP Sumi, Y Willis, WJ Wolf, K Xu, N Zachary, DS AF Bearden, IG Boggild, H Boissevain, J Christiansen, PHL Conin, L Dodd, J Erazmus, B Esumi, S Fabjan, CW Ferenc, D Franz, A Gaardhoje, JJ Hansen, AG Hansen, O Hardtke, D van Hecke, H Holzer, EB Humanic, TJ Hummel, P Jacak, BV Kaimi, K Kaneta, M Kohama, T Kopytine, M Leltchouk, M Ljubicic, A Lorstad, B Maeda, N Martin, L Medvedev, A Murray, M Ohnishi, H Paic, G Pandey, SU Piuz, F Pluta, J Polychronakos, V Potekhin, M Poulard, G Reichhold, D Sakaguchi, A Schmidt-Sorensen, J Simon-Gillo, J Sondheim, W Sugitate, T Sullivan, JP Sumi, Y Willis, WJ Wolf, K Xu, N Zachary, DS TI Space-time evolution of the hadronic source in peripheral to central Pb plus Pb collisions SO EUROPEAN PHYSICAL JOURNAL C LA English DT Article ID HEAVY-ION COLLISIONS; IMAGING CHERENKOV DETECTOR; QUARK-GLUON PLASMA; PION INTERFEROMETRY; PB+PB COLLISIONS; CERN-SPS; STRANGENESS; PARTICLE AB Two-particle correlations of negative pions as a function of charged particle multiplicity are studied in Pb+Pb collisions at roots = 17.3GeV per nucleon using the NA44 experiment at the CERN Super Proton Synchrotron(SPS). We find that the source size parameters increase with the charged particle multiplicity. However the slope of the: source size parameters plotted as a function of charged multiplicity is slightly larger at high multiplicity than at low multiplicity. The value of lambda is independent of charged multiplicity. For Pb+Pb collisions, R-L is larger than R-TS and R-TO for all multiplicity intervals, whereas these three radius parameters were approximately equal in S+Nucleus collisions. The ratios (R-L/R-TS) and (R-L/R-TO) for Pb+Pb data show almost no dependence on charged multiplicity. The duration of pion emission Delta tau is constant at 3.8+/-1.1 fm/c as a function of the charged multiplicity in Pb+Pb collisions. Effective volume (V) is also calculated as V=pi x R-TS(2) x R-L; assuming a cylindrically shaped source. We found, within the limited statistics, the effective Volume rapidly increases at high multiplicity. C1 Niels Bohr Inst, DK-2100 Copenhagen, Denmark. Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Columbia Univ, Dept Phys, New York, NY 10027 USA. Nucl Phys Lab Nantes, F-44072 Nantes, France. Hiroshima Univ, Higashihiroshima 7398526, Japan. CERN, CH-1211 Geneva 23, Switzerland. Rudjer Boskovic Inst, Zagreb, Croatia. Texas A&M Univ, Inst Cyclotron, College Stn, TX 77843 USA. Ohio State Univ, Dept Phys, Columbus, OH 43210 USA. SUNY Stony Brook, Stony Brook, NY 11973 USA. Lund Univ, Dept Phys, S-22362 Lund, Sweden. Brookhaven Natl Lab, Upton, NY 11973 USA. RP Sakaguchi, A (reprint author), Niels Bohr Inst, Blegdamsvej 17, DK-2100 Copenhagen, Denmark. RI Bearden, Ian/M-4504-2014; OI Bearden, Ian/0000-0003-2784-3094; Christiansen, Peter/0000-0001-7066-3473; Gaardhoje, Jens-Jorgen/0000-0001-6122-4698 NR 23 TC 10 Z9 10 U1 0 U2 0 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 DEC PY 2000 VL 18 IS 2 BP 317 EP 325 DI 10.1007/s100520000543 PG 9 WC Physics, Particles & Fields SC Physics GA 392NC UT WOS:000166416700008 ER PT J AU Putz, M Kremer, K Grest, GS AF Putz, M Kremer, K Grest, GS TI Reply to the Comment by A. Wischnewski and D. Richter on "What is the entanglement length in a polymer melt?" SO EUROPHYSICS LETTERS LA English DT Editorial Material ID CONCENTRATED ISOTROPIC SOLUTIONS; SEMIFLEXIBLE POLYMERS; VISCOELASTICITY; REPTATION C1 Max Planck Inst Polymerforsch, D-55021 Mainz, Germany. Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Putz, M (reprint author), Max Planck Inst Polymerforsch, Postfach 3148, D-55021 Mainz, Germany. RI Kremer, Kurt/G-5652-2011; MPIP, Theory/I-9884-2014 NR 7 TC 12 Z9 12 U1 1 U2 12 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 DEC PY 2000 VL 52 IS 6 BP 721 EP 722 DI 10.1209/epl/i2000-00498-4 PG 2 WC Physics, Multidisciplinary SC Physics GA 386JA UT WOS:000166056500020 ER PT J AU Cummings, EB AF Cummings, EB TI An image processing and optimal nonlinear filtering technique for particle image velocimetry of microflows SO EXPERIMENTS IN FLUIDS LA English DT Article; Proceedings Paper CT 3rd International Workshop on Particle Image Velocimetry CY SEP 16-18, 1999 CL SANTA BARBARA, CALIFORNIA AB We have developed a processing methodology for extracting accurate measurements from ensembles of image pairs of particle-laden steady microflows. Processing the subimages and their correlations produces an estimate of the particle-displacement probability-density function that improves with ensemble averaging. An optimal nonlinear filter precisely extracts flow measurements from the measured displacement distribution. This methodology has been used to dissect the pressure-driven component from the electrokinetic component of particle motion in particle-image videos with no depth resolution of a planar microflow past an obstacle array and bubble. C1 Sandia Natl Labs, Livermore, CA 94550 USA. RP Cummings, EB (reprint author), Sandia Natl Labs, Livermore, CA 94550 USA. NR 7 TC 17 Z9 17 U1 0 U2 1 PU SPRINGER-VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 USA SN 0723-4864 J9 EXP FLUIDS JI Exp. Fluids PD DEC PY 2000 VL 29 SU S BP S42 EP S50 DI 10.1007/s003480070006 PG 9 WC Engineering, Mechanical; Mechanics SC Engineering; Mechanics GA 422LH UT WOS:000168119400006 ER PT J AU Plague, GR McArthur, JV AF Plague, GR McArthur, JV TI Polymorphic larval retreats in the net-spinning caddisfly Macrostemum carolina (Trichoptera : Hydropsychidae): Form and putative function SO FLORIDA ENTOMOLOGIST LA English DT Article ID DIMORPHISM C1 Univ Georgia, Savannah River Ecol Lab, Aiken, SC 29802 USA. RP Plague, GR (reprint author), Univ Georgia, Savannah River Ecol Lab, PO Drawer E, Aiken, SC 29802 USA. NR 16 TC 3 Z9 3 U1 0 U2 2 PU FLORIDA ENTOMOLOGICAL SOC PI LUTZ PA 16125 E LAKE BURRELL DR, LUTZ, FL 33548 USA SN 0015-4040 J9 FLA ENTOMOL JI Fla. Entomol. PD DEC PY 2000 VL 83 IS 4 BP 497 EP 500 DI 10.2307/3496728 PG 4 WC Entomology SC Entomology GA 386FA UT WOS:000166049000014 ER PT J AU Miller, SP Sharitz, RR AF Miller, SP Sharitz, RR TI Manipulation of flooding and arbuscular mycorrhiza formation influences growth and nutrition of two semiaquatic grass species SO FUNCTIONAL ECOLOGY LA English DT Article DE arbuscular mycorrhiza; flooding; Leersia hexandra; Panicum hemitomon; wetland grasses ID WIDE HYDROLOGIC GRADIENT; PLANT-RESPONSE; FUNGI; WETLAND; PHOSPHORUS; ROOTS; COLONIZATION; NUTRIENT; INFECTION; AVAILABILITY AB 1. Two semiaquatic grasses, Panicum hemitomon Schultes and Leersia hexandra Schwartz, were grown for 12 weeks in sterilized soil in experimental mesocosms, with and without the addition of arbuscular mycorrhizal (AM) fungal inoculum (as nonsterilized soil), under the following rooting-zone flood regimes: waterlogged (W), free-draining (D), beginning W and ending D (W-D), and beginning D and ending W (D-W). The purpose of the experiment was to determine whether these controlled water regimes affected both colonization of wetland grasses by AM fungi and the effects of the colonization on various plant parameters. 2. Water regime, addition of inoculum, and their interaction were highly significant effects on total and proportion of root length colonized by AM fungi. Trends were very similar for the two grass species. Colonization was less and plants smaller in the W and W-D than in the D and D-W treatments. The viability of mycorrhiza at the end of the experiment, as measured by vital staining techniques, was not affected by changes in water level. 3. Colonized plants in all water level treatments showed an improvement in phosphorus (P) nutrition over noncolonized plants. Colonized grasses of both species gained consistently more P per plant and had greater tissue P concentrations, with the greatest P concentration in the most heavily colonized plants (from the D and D-W treatments). 4. The effect of flooding on the mycorrhizal association depended largely on the extent to which the association was already established when the flooding occurred. Flooding reduced the initiation of colonization either directly or indirectly, but once the fungi were established in the roots they were able to maintain and expand with the growing root system. C1 Savannah River Ecol Lab, Aiken, SC 29802 USA. Univ Georgia, Inst Ecol, Athens, GA 30605 USA. Univ Georgia, Dept Bot, Athens, GA 30605 USA. RP Miller, SP (reprint author), Univ Kentucky, Dept Agron, Lexington, KY 40546 USA. NR 45 TC 52 Z9 61 U1 5 U2 20 PU WILEY-BLACKWELL PI MALDEN PA COMMERCE PLACE, 350 MAIN ST, MALDEN 02148, MA USA SN 0269-8463 J9 FUNCT ECOL JI Funct. Ecol. PD DEC PY 2000 VL 14 IS 6 BP 738 EP 748 DI 10.1046/j.1365-2435.2000.00481.x PG 11 WC Ecology SC Environmental Sciences & Ecology GA 392FT UT WOS:000166401300010 ER PT J AU Lieb, JD de Solorzano, CO Rodriguez, EG Jones, A Angelo, M Lockett, S Meyer, BJ AF Lieb, JD de Solorzano, CO Rodriguez, EG Jones, A Angelo, M Lockett, S Meyer, BJ TI The Caenorhabditis elegans dosage compensation machinery is recruited to X chromosome DNA attached to an autosome SO GENETICS LA English DT Article ID SEX-SPECIFIC REGULATION; MALE-SPECIFIC LETHAL-2; INACTIVATION CENTER; DROSOPHILA-MELANOGASTER; GENE-EXPRESSION; RNA PAINTS; C-ELEGANS; PROTEIN; NEMATODE; ENCODES AB The dosage compensation machinery of Caenorhabditis elegans is targeted specifically to the X chromosomes of hermaphrodites (XX) to reduce gene expression by half. Many of the trans-acting factors that direct the dosage compensation machinery to X have been identified, but none of the proposed cis-acting X chromosome-recognition elements needed to recruit dosage compensation components have been found. To study X chromosome recognition, we explored whether portions of an X chromosome attached to an autosome are competent to bind the C. elegans dosage compensation complex (DCC). To do so, we devised a three-dimensional in situ approach that allowed us to compare the volume, position, and number of chromosomal and subchromosomal bodies bound by the dosage compensation machinery in wild-type XX nuclei and XX nuclei carrying an X duplication. The dosage compensation complex was found to associate with a duplication of the right 30% of X, but the complex did not spread onto adjacent autosomal sequences. This result indicates that all the information required to specify X chromosome identity resides on the duplication and that the dosage compensation machinery can localize to a site distinct from the full-length hermaphrodite X chromosome. In contrast, smaller duplications of other regions of X appeared to not support localization of the DCC. In a separate effort to identify cis-acting X recognition elements, we used a computational approach to analyze genomic DNA sequences for the presence of short motifs that were abundant and overrepresented on X relative to autosomes. Fourteen families of X-enriched motifs were discovered and mapped onto the X chromosome. C1 Univ Calif Berkeley, Howard Hughes Med Inst, Berkeley, CA 94720 USA. Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. Whitehead Inst, Cambridge, MA 02139 USA. MIT, Cambridge, MA 02139 USA. RP Univ Calif Berkeley, Howard Hughes Med Inst, 401 Barker Hall 3204, Berkeley, CA 94720 USA. EM bjmeyer@uclink4.berkeley.edu RI Ortiz de Solorzano, Carlos/G-3278-2010 OI Ortiz de Solorzano, Carlos/0000-0001-8720-0205 FU NIGMS NIH HHS [R01 GM030702] NR 58 TC 21 Z9 23 U1 0 U2 0 PU GENETICS SOCIETY AMERICA PI BETHESDA PA 9650 ROCKVILLE AVE, BETHESDA, MD 20814 USA SN 0016-6731 EI 1943-2631 J9 GENETICS JI Genetics PD DEC PY 2000 VL 156 IS 4 BP 1603 EP 1621 PG 19 WC Genetics & Heredity SC Genetics & Heredity GA 381AL UT WOS:000165740100014 PM 11102361 ER PT J AU Callow, MJ Dudoit, S Gong, EL Speed, TP Rubin, EM AF Callow, MJ Dudoit, S Gong, EL Speed, TP Rubin, EM TI Microarray expression profiling identifies genes with altered expression in HDL-deficient mice SO GENOME RESEARCH LA English DT Article ID HIGH-DENSITY-LIPOPROTEIN; APOLIPOPROTEIN-A-I; RECEPTOR SR-BI; SCAVENGER RECEPTOR; LIPID-PEROXIDATION; TRANSCRIPTIONAL PROGRAM; TRANSGENIC MICE; DNA MICROARRAY; RAT-LIVER; CHOLESTEROL AB Based on the assumption that severe alterations in the expression of genes known to be involved in high-density lipoprotein (HDL) metabolism may affect the expression of other genes, we screened an array of >5000 mouse expressed sequence tags For altered gene expression in the livers of two lines of mice with dramatic decreases in HDL plasma concentrations. Labeled cDNA from livers of apolipoprotein Al (apoAl)-knockout mice, scavenger receptor BI (SR-BI) transgenic mice, and control mice were cohybridized to microarrays. Two-sample t statistics were used to identify genes with altered expression levels in the knockout or transgenic mice compared with control mice. In the SR-BI group we found nine array elements representing at least Five genes that were significantly altered on the basis of an adjusted P value < 0.05. In the apoAl-knockout group, eight array elements representing Four genes were altered compared with the control group (adjusted P < 0.05). Several of the genes identified in the SR-BI transgenic suggest altered sterol metabolism and oxidative processes. These studies illustrate the use of multiple-testing methods for the identification of genes with altered expression in replicated microarray experiments. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Genome Sci Dept, Berkeley, CA 94720 USA. Stanford Univ, Dept Biochem, Stanford, CA 94305 USA. Univ Calif Berkeley, Dept Stat, Berkeley, CA 94720 USA. Univ Calif Berkeley, Program Biostat, Berkeley, CA 94720 USA. RP Callow, MJ (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Genome Sci Dept, Berkeley, CA 94720 USA. RI Speed, Terence /B-8085-2009 OI Speed, Terence /0000-0002-5403-7998 FU NHLBI NIH HHS [1RO1HL63897-01]; NIMH NIH HHS [5R01MH61665-02] NR 38 TC 164 Z9 170 U1 1 U2 6 PU COLD SPRING HARBOR LAB PRESS PI PLAINVIEW PA 1 BUNGTOWN RD, PLAINVIEW, NY 11724 USA SN 1088-9051 J9 GENOME RES JI Genome Res. PD DEC PY 2000 VL 10 IS 12 BP 2022 EP 2029 DI 10.1101/gr.10.12.2022 PG 8 WC Biochemistry & Molecular Biology; Biotechnology & Applied Microbiology; Genetics & Heredity SC Biochemistry & Molecular Biology; Biotechnology & Applied Microbiology; Genetics & Heredity GA 382QN UT WOS:000165833900018 PM 11116096 ER PT J AU Thomas-Keprta, KL Bazylinski, DA Kirschvink, JL Clemett, SJ McKay, DS Wentworth, SJ Vali, H Gibson, EK Romanek, CS AF Thomas-Keprta, KL Bazylinski, DA Kirschvink, JL Clemett, SJ McKay, DS Wentworth, SJ Vali, H Gibson, EK Romanek, CS TI Elongated prismatic magnetite crystals in ALH84001 carbonate globules: Potential Martian magnetofossils SO GEOCHIMICA ET COSMOCHIMICA ACTA LA English DT Review ID DEEP-SEA SEDIMENTS; DOMAIN TITANOMAGNETITE PARTICLES; TRANSMISSION ELECTRON-MICROSCOPE; ULTRAFINE-GRAINED MAGNETITE; NORTHERN APPALACHIAN BASIN; MAGNETOTACTIC BACTERIA; BIOGENIC MAGNETITE; METEORITE ALH84001; SINGLE-DOMAIN; REMANENT MAGNETIZATION AB Using transmission electron microscopy (TEM), we have analyzed magnetite (Fe3O4) crystals acid-extracted from carbonate globules in Martian meteorite ALH84001. We studied 594 magnetites from ALH84001 and grouped them into three populations on the basis of morphology: 389 were irregularly shaped, 164 were elongated prisms, and 41 were whisker-like. As a possible terrestrial analog for the ALH84001 elongated prisms, we compared these magnetites with those produced by the terrestrial magnetotactic bacteria strain MV-1. By TEM again, we examined 206 magnetites recovered from strain MV-1 cells. Natural (Darwinian) selection in terrestrial magnetotactic bacteria appears to have resulted in the formation of intracellular magnetite crystals having the physical and chemical properties that optimize their magnetic moment. In this study, we describe six properties of magnetite produced by biologically controlled mechanisms (e.g., magnetotactic bacteria), properties that, collectively, are not observed in any known population of inorganic magnetites. These criteria can be used to distinguish one of the modes of origin for magnetites from samples with complex or unknown histories. Of the ALH84001 magnetites that we have examined, the elongated prismatic magnetite particles (similar to 27% of the total) are indistinguishable from the MV-1 magnetites in five of these six characteristics observed for biogenically controlled mineralization of magnetite crystals. Copyright (C) 2000 Elsevier Science Ltd. C1 Lockheed Martin, Houston, TX 77058 USA. Iowa State Univ Sci & Technol, Dept Microbiol, Ames, IA 50011 USA. CALTECH, Div Geol & Planetary Sci, Pasadena, CA 91125 USA. NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA. McGill Univ, Dept Earth & Planetary Sci, Montreal, PQ H3A 2A7, Canada. Univ Georgia, Savannah River Ecol Lab, Aiken, SC 29802 USA. RP Lockheed Martin, 2400 NASA Rd 1,Mail Code C23, Houston, TX 77058 USA. EM kthomas@ems.jsc.nasa.gov RI Vali, Hojatollah/F-3511-2012 OI Vali, Hojatollah/0000-0003-3464-9943 NR 207 TC 173 Z9 182 U1 5 U2 30 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0016-7037 EI 1872-9533 J9 GEOCHIM COSMOCHIM AC JI Geochim. Cosmochim. Acta PD DEC PY 2000 VL 64 IS 23 BP 4049 EP 4081 DI 10.1016/S0016-7037(00)00481-6 PG 33 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 376FP UT WOS:000165447800010 PM 11543573 ER PT J AU Crooker, NU Shodhan, S Gosling, JT Simmerer, J Lepping, RP Steinberg, JT Kahler, SW AF Crooker, NU Shodhan, S Gosling, JT Simmerer, J Lepping, RP Steinberg, JT Kahler, SW TI Density extremes in the solar wind SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID CORONAL MASS EJECTIONS; INTER-PLANETARY; MAGNETIC CLOUDS; FLUCTUATIONS; EVENTS; 1-AU; FLUX AB The largest density variations in the solar wind occur near the streamer belt, where frequently they are associated with interplanetary coronal mass ejections (ICMEs). They tend to be embedded in larger-scale regions of high pressure: high densities in ICME sheaths and corotating interaction regions and low densities in structures with distinctive, high-magnetic-pressure profiles, sometimes within ICMEs. On average, however, ICME densities are similar to ambient-wind densities. I;or a set of 34 ICMEs identified in Wind data as magnetic clouds, the average density was 11 cm(-3) in both the clouds and all slow wind during the same period. A set of low-density structures observed earlier by ISEE 3 recurred for three solar rotations, possibly owing to recurrence of the streamer belt itself, with its frequent transient outflows. Density averages less than 1 cm(-3) show a possible solar cycle variation which peaks 1-2 years prior to the peak of ICME signatures. C1 Boston Univ, Ctr Space Phys, Boston, MA 02215 USA. Univ Calif Los Alamos Natl Lab, Los Alamos, NM USA. NASA, Goddard Space Flight Ctr, Extraterr Phys Lab, Greenbelt, MD 20771 USA. USAF, Res Lab, Space Vehicles Directorate, Hanscom AFB, MA USA. RP Crooker, NU (reprint author), Boston Univ, Ctr Space Phys, Boston, MA 02215 USA. NR 28 TC 26 Z9 26 U1 1 U2 2 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD DEC 1 PY 2000 VL 27 IS 23 BP 3769 EP 3772 DI 10.1029/2000GL003788 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 379MQ UT WOS:000165646700003 ER PT J AU Terasawa, T Kasaba, Y Tsubouchi, K Mukai, T Saito, Y Frank, LA Paterson, WR Ackerson, K Matsumoto, H Kojima, H Matsui, H Larson, D Lin, R Phan, T Steinberg, J McComas, D Skoug, R Fujimoto, M Hoshino, M Nishida, A AF Terasawa, T Kasaba, Y Tsubouchi, K Mukai, T Saito, Y Frank, LA Paterson, WR Ackerson, K Matsumoto, H Kojima, H Matsui, H Larson, D Lin, R Phan, T Steinberg, J McComas, D Skoug, R Fujimoto, M Hoshino, M Nishida, A TI GEOTAIL observations of anomalously low density plasma in the magnetosheath SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID SOLAR-WIND; SPACECRAFT AB During the anomalously low density solar wind interval of May 1999, GEOTAIL was in the magnetosheath for similar to 37 hours after making an inbound crossing of the expanding bow shuck at similar to 8 R-E upstream of its nominal position. Comparison among data sets obtained from GEOTAIL (magnetosheath), WIND (near upstream - bow shock), and ACE (far upstream) reveals several unique features: Firstly, during the interval of 1430-1530 UT on 11 May, we observed both in the solar wind and magnetosheath double-peaked protons with a peak separation of 250-300 km/s, which was close to the local Alfven velocity during the event. Secondly, rye observed extremely strong strahl electrons both in the solar wind and magnetosheath during the interval of 0600-2100 UT on 11 May 1999. We present an overview of the GEOTAIL observations, and discuss their physical significance. C1 Univ Tokyo, Fac Sci, Dept Earth & Planetary Sci, Tokyo 1130033, Japan. Inst Space & Astronaut Sci, Sagamihara, Kanagawa 2298510, Japan. Univ Iowa, Dept Phys & Astron, Iowa City, IA 52242 USA. Kyoto Univ, Ctr Radio Atmospher Sci, Uji 6110011, Japan. Tokyo Inst Technol, Tokyo 1528551, Japan. Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Terasawa, T (reprint author), Univ Tokyo, Fac Sci, Dept Earth & Planetary Sci, Tokyo 1130033, Japan. RI Paterson, William/F-5684-2012; Tsubouchi, Ken/B-9343-2015 OI Tsubouchi, Ken/0000-0003-1963-1112 NR 12 TC 9 Z9 9 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD DEC 1 PY 2000 VL 27 IS 23 BP 3781 EP 3784 DI 10.1029/2000GL000087 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 379MQ UT WOS:000165646700006 ER PT J AU Soler, T Foote, RH Hoyle, D Bocean, V AF Soler, T Foote, RH Hoyle, D Bocean, V TI Accurate GPS orientation of a long baseline for neutrino oscillation experiments at Fermilab SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article AB Recent research in elementary particle physics is concentrating a great amount of effort on neutrino oscillation experiments. These studies require the accurate pointing of neutrino beams between two distant points. The Fermi National Accelerator Laboratory (Fermilab) intends to build a new particle beamline to direct a beam of muon neutrinos from its Main Injector toward a far-off (735 km away) underground detector capable of searching for non-zero neutrino mass by looking for neutrino oscillations. This paper describes the GPS work carried out to accurately position the reference ground marks at the two sites from which the spatial orientation of the baseline can be accurately determined. The effect of plate rotations on the absolute orientation of the baseline was also investigated. C1 NOAA, NOS, Natl Geodet Survey, Silver Spring, MD 20910 USA. Fermi Natl Accelerator Lab, Ctr Tech, Batavia, IL 60510 USA. RP Soler, T (reprint author), NOAA, NOS, Natl Geodet Survey, 1315 EW Highway, Silver Spring, MD 20910 USA. RI Soler, Tomas/F-6386-2010 NR 10 TC 2 Z9 2 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD DEC 1 PY 2000 VL 27 IS 23 BP 3921 EP 3924 DI 10.1029/2000GL011539 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 379MQ UT WOS:000165646700041 ER PT J AU Matamala, R Schlesinger, WH AF Matamala, R Schlesinger, WH TI Effects of elevated atmospheric CO2 on fine root production and activity in an intact temperate forest ecosystem SO GLOBAL CHANGE BIOLOGY LA English DT Article DE elevated CO2; forest ecosystem; Pinus taeda; root production; root phosphatase activity; root respiration ID PONDEROSA PINE-SEEDLINGS; CARBON-DIOXIDE; MYCORRHIZAL COLONIZATION; BETULA-PAPYRIFERA; DIRECT INHIBITION; LOBLOLLY-PINE; SOIL-NITROGEN; ENRICHMENT; TURNOVER; DYNAMICS AB We investigated the effects of elevated atmospheric CO2 concentrations (ambient + 200 ppm) on fine root production and soil carbon dynamics in a loblolly pine (Pinus taeda) forest subject to free-air CO2 enrichment (FACE) near Durham, NC (USA). Live fine root mass (LFR) showed less seasonal variation than dead fine root mass (DFR), which was correlated with seasonal changes in soil moisture and soil temperature. LFR mass increased significantly (by 86%) in the elevated CO2 treatment, with an increment of 37 g(dry weight) m(-2) above the control plots after two years of CO2 fumigation. There was no long-term increment in DFR associated with elevated CO2, but significant seasonal accumulations of DFR mass occurred during the summer of the second year of fumigation. Overall, root net primary production (RNPP) was not significantly different, but annual carbon inputs were 21.7 gC m(-2) y(-1) (68%) higher in the elevated CO2 treatment compared to controls. Specific root respiration was not altered by the CO2 treatment during most of the year; however, it was significantly higher by 21% and 13% in September 1997 and May 1998, respectively, in elevated CO2. We did not find statistically significant differences in the C/N ratio of the root tissue, root decomposition or phosphatase activity in soil and roots associated with the treatment. Our data show that the early response of a loblolly pine forest ecosystem subject to CO2 enrichment is an increase in its fine root population and a trend towards higher total RNPP after two years of CO2 fumigation. C1 Duke Univ, Dept Bot, Durham, NC 27708 USA. RP Matamala, R (reprint author), Argonne Natl Lab, Div Environm Res, 9700 S Cass Ave, Argonne, IL 60439 USA. NR 67 TC 147 Z9 164 U1 3 U2 41 PU BLACKWELL SCIENCE LTD PI OXFORD PA P O BOX 88, OSNEY MEAD, OXFORD OX2 0NE, OXON, ENGLAND SN 1354-1013 J9 GLOB CHANGE BIOL JI Glob. Change Biol. PD DEC PY 2000 VL 6 IS 8 BP 967 EP 979 DI 10.1046/j.1365-2486.2000.00374.x PG 13 WC Biodiversity Conservation; Ecology; Environmental Sciences SC Biodiversity & Conservation; Environmental Sciences & Ecology GA 394KV UT WOS:000166524000011 ER PT J AU Rogers, A Humphries, SW AF Rogers, A Humphries, SW TI A mechanistic evaluation of photosynthetic acclimation at elevated CO2 SO GLOBAL CHANGE BIOLOGY LA English DT Article DE acclimation; C-3 photosynthesis; elevated carbon dioxide; modelling; Rubisco ID RISING ATMOSPHERIC CO2; PHASEOLUS-VULGARIS L; LONG-TERM EXPOSURE; LEAF GAS-EXCHANGE; CARBON-DIOXIDE; NITROGEN NUTRITION; ENRICHMENT; PLANTS; FOREST; LEAVES AB Plants grown at elevated pCO(2) often fail to sustain the initial stimulation of net CO2 uptake rate (A). This reduced, acclimated, stimulation of A often occurs concomitantly with a reduction in the maximum carboxylation velocity (V-c,V-max) of Rubisco. To investigate this relationship we used the Farquhar model of C-3 photosynthesis to predict the minimum V-c,V-max capable of supporting the acclimated stimulation in A observed at elevated pCO(2). For a wide range of species grown at elevated pCO(2) under contrasting conditions we found a strong correlation between observed and predicted values of V-c,V-max. This exercise mechanistically and quantitatively demonstrated that the observed acclimated stimulation of A and the simultaneous decrease in V-c,V-max observed at elevated pCO(2) is mechanistically consistent. With the exception of plants grown at a high elevated pCO(2) (> 90 Pa), which show evidence of an excess investment in Rubisco, the failure to maintain the initial stimulation of A is almost entirely attributable to the decrease in V-c,V-max and investment in Rubisco is coupled to requirements. C1 Brookhaven Natl Lab, Dept Environm Sci, Upton, NY 11973 USA. RP Rogers, A (reprint author), Brookhaven Natl Lab, Dept Environm Sci, Upton, NY 11973 USA. RI Rogers, Alistair/E-1177-2011 OI Rogers, Alistair/0000-0001-9262-7430 NR 48 TC 81 Z9 89 U1 0 U2 26 PU BLACKWELL SCIENCE LTD PI OXFORD PA P O BOX 88, OSNEY MEAD, OXFORD OX2 0NE, OXON, ENGLAND SN 1354-1013 J9 GLOB CHANGE BIOL JI Glob. Change Biol. PD DEC PY 2000 VL 6 IS 8 BP 1005 EP 1011 DI 10.1046/j.1365-2486.2000.00375.x PG 7 WC Biodiversity Conservation; Ecology; Environmental Sciences SC Biodiversity & Conservation; Environmental Sciences & Ecology GA 394KV UT WOS:000166524000014 ER PT J AU Korte, N Kearl, PM Siegrist, RL Muck, MT Schlosser, RM AF Korte, N Kearl, PM Siegrist, RL Muck, MT Schlosser, RM TI An evaluation of horizontal recirculation using single-well tests, pumping tests, tracer tests, and the colloidal borescope SO GROUND WATER MONITORING AND REMEDIATION LA English DT Article ID TRANSPORT; REMEDIATION; WATER; INTERMITTENT; IRRIGATION; BROMIDE; FIELD AB Extensive hydrodynamic testing was performed as part of a program to evaluate horizontal recirculation as a means of removing contaminants from thin, interbedded aquifers. Two test sites, each containing a pair of horizontal recirculation wells, were evaluated using various hydraulic tests. Results of these evaluations showed that ground water was intercepted more than 100 feet beyond the wells. and that the hydraulic gradient increased by more than two orders of magnitude. Aquifer heterogeneity: however, controlled the efficiency and uniformity of ground water flow Heterogeneity was assessed with a variety of techniques. Bromide tracer tests and the colloidal borescope provided the most useful data. For example, at an uncontaminated site, the leading edge of the bromide tracer traversed the 100 feet between the injection and extraction wells in 21 hours, and the peak bromide concentration was observed in 2.6 days, compared with the four days predicted by a pumping test. The resulting maximum velocity calculation was consistent with measurements made with the borescope in preferential flow zones. Data obtained from a highly contaminated location indicated that assessments of aquifer heterogeniety are further complicated by the presence of DNAPL. Very low flow occurred in a highly contaminated zone, despite the fact that lithologic descriptions indicated that this region contained permeable sand and gravel. C1 Oak Ridge Natl Lab, Restorat Technol Grp, Div Environm Sci, Grand Junct Off, Grand Junction, CO 81503 USA. RP Korte, N (reprint author), Oak Ridge Natl Lab, Restorat Technol Grp, Div Environm Sci, Grand Junct Off, 2597 B 3-4 Rd, Grand Junction, CO 81503 USA. NR 21 TC 4 Z9 4 U1 0 U2 1 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 WIN PY 2000 VL 20 IS 1 BP 78 EP 85 DI 10.1111/j.1745-6592.2000.tb00254.x PG 8 WC Water Resources SC Water Resources GA 309HF UT WOS:000086761900007 ER PT J AU Beck, WL AF Beck, WL TI 2000 Founders Award presented to Roger J. Cloutier at the 45th Annual Meeting of the Health Physics Society, Denver, CO - 25-29 June 2000 SO HEALTH PHYSICS LA English DT Biographical-Item C1 Oak Ridge Associated Univ, Oak Ridge, TN 37831 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU LIPPINCOTT WILLIAMS & WILKINS PI PHILADELPHIA PA 530 WALNUT ST, PHILADELPHIA, PA 19106-3621 USA SN 0017-9078 EI 1538-5159 J9 HEALTH PHYS JI Health Phys. PD DEC PY 2000 VL 79 IS 6 BP 645 EP 646 DI 10.1097/00004032-200012000-00002 PG 2 WC Environmental Sciences; Public, Environmental & Occupational Health; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Environmental Sciences & Ecology; Public, Environmental & Occupational Health; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA 375GT UT WOS:000165391700001 PM 11089794 ER PT J AU Whicker, JJ Baker, GD Wasiolek, PT AF Whicker, JJ Baker, GD Wasiolek, PT TI Quantitative measurements of airflow inside a nuclear laboratory SO HEALTH PHYSICS LA English DT Article DE air sampling; ventilation; radioactivity; airborne; radiation protection ID AIR-FLOW; INDOOR; ROOM; POLLUTANT AB Dispersion dynamics of accidentally released radioactive aerosols or gases through laboratory workrooms are determined primarily by airflow, which impacts the level of human exposure and the response of air monitoring instrumentation. Therefore, applying conclusions derived from measurements of the fundamental aspects of airflow (velocity, direction, and turbulence) can lead to better protection of workers by suggesting appropriate locations for air monitoring and sampling. Historically, it has been very difficult to quantitatively measure these fundamental aspects of indoor airflow because of the low flow rates (often <10 cm s(-1)) and difficulties in quantitative measurement of three-dimensional airflow, Recent advances in sonic anemometry have enabled such measurements. For this study, a sonic anemometer was used that was capable of measuring airflow velocities with a sensitivity of about 0.5 cm s(-1) for each of the three-directional components. A sampling frequency of 1 Hz was selected to measure the fluctuations in the air velocity associated with turbulence and expressed in terms of "turbulence intensity," Point measurements of airflow velocities, directions, and turbulence intensities were made at 69 locations in a mechanically ventilated plutonium laboratory located at Los Alamos National Laboratory, Although the measurements were not made with workers present, all measurements were made at a height of 1.5 m, approximately the height of a worker's breathing zone (BZ), Velocities ranged from 8 cm s(-1) to 11 cm s(-1), with a median velocity of 18 cm s(-1). Percent turbulence intensities ranged from 13% to 57% with a median of 34%. The measured velocities and turbulence intensities in the laboratory showed that forced convective flows and turbulent eddy diffusion drive dispersion of released aerosols or gases. Results show that after an airborne release, mixing within the room can take minutes and may not always be complete. This is contrary to simplifying assumptions made by some risk modeling of accidentally released materials in a room. Our results also suggest that the mixing pattern would not be omnidirectional at most release locations, especially in the early stages of the release. Finally, airflow directions were upwards in breathing zones at most workstations. Because most releases in the plutonium laboratory occur at a height immediately below the BZ, the concentrated aerosol could be lifted into the BZ, followed by dispersal to the air monitor with the initiation of alarm. C1 Univ Calif Los Alamos Natl Lab, Hlth Phys Measurements Grp, Los Alamos, NM 87545 USA. Univ Calif Los Alamos Natl Lab, Nucl Mat Technol Grp, Los Alamos, NM 87545 USA. NR 27 TC 8 Z9 9 U1 0 U2 2 PU LIPPINCOTT WILLIAMS & WILKINS PI PHILADELPHIA PA 530 WALNUT ST, PHILADELPHIA, PA 19106-3621 USA SN 0017-9078 EI 1538-5159 J9 HEALTH PHYS JI Health Phys. PD DEC PY 2000 VL 79 IS 6 BP 712 EP 721 DI 10.1097/00004032-200012000-00018 PG 10 WC Environmental Sciences; Public, Environmental & Occupational Health; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Environmental Sciences & Ecology; Public, Environmental & Occupational Health; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA 375GT UT WOS:000165391700015 PM 11089809 ER PT J AU Lloyd, RD Taylor, GN Fisher, DR Schlenker, RA Miller, SC AF Lloyd, RD Taylor, GN Fisher, DR Schlenker, RA Miller, SC TI Effective thresholds for induction of skeletal malignancies by radionuclides SO HEALTH PHYSICS LA English DT Article DE dogs; skeleton; radionuclide; cancer ID RELATIVE DISTRIBUTION FACTORS; BONE CANCER; DOSIMETRY; BEAGLES; PU-239; RADIUM-224; RETENTION; EMITTERS; RA-226; CELLS AB Our analysis of data from the beagle project completed at the University of Utah has provided some comparisons that appear to be useful in testing the model proposed by Raabe of effective thresholds for induction of skeletal malignancy by bone-seeking radionuclides in beagles, Raabe's model predicted that cumulative skeletal doses of less than about 0.9 to 1.4 Gy from alpha emitters or 28 to 70 Gy from beta emitters deposited in the skeleton require a long enough time for bone cancer expression that the dog's natural lifespan would be exceeded before the tumor appeared Results fi om the Utah beagle project seem to confirm these projections for Ra-226, Ra-228 and, perhaps, for Sr-90. The lowest doses at which malignant bone tumors were observed in animals injected with these radium isotopes were about 0.9 Gy (Ra-226) and 3 Gy (Ra-228). For the beta emitter. Sr-90, th, lowest doses at which bone tumors were seen were about 18, 50 and 70 Gy with an expectation for naturally occurring tumor of about one. Twenty-six of the two hundred and thirty-three Utah beagles given monomeric Pu-239 that developed skeletal malignancies had doses between 0.02 and 051 Gy (80 of these dogs had skeletal doses of less than 0.9 Gy). Three dog: of 54 given Am-241 with doses lower than 0.9 Gy had bone tumors at 0.23, 0.56, and 0.88 Gy with the expectation of about one naturally occurring case. For 25 animals injected with Th-228 at skeletal doses below 0.9 Gy, one bone tumor dog had a dose of about 0.4 Gy, and the expectation of a dog with natural tumor among the group was only about 0.38. Five beagles of 74 given Ra-224 with resulting doses of less than 0.9 Gy died with skeletal malignancy at 0.32 Gy or less with an expectation for non Ra-224 induced tumor of about one. It appears that Raabe's proposal might be confirmed for some but not all of the radionuclides used in the Utah studies. Models presented in earlier papers by Raabe provide results that are somewhat different from his recent abstract and compare more favorably with those cited herein for Utah dogs. Re-examination of our data for these analyses has suggested a novel concept for calculation of carcinogenic dose to endosteal bone surfaces. C1 Univ Utah, Dept Radiol, Div Radiobiol, Salt Lake City, UT 84108 USA. Pacific NW Natl Lab, Richland, WA 99352 USA. Madison Res Grp Inc, Willowbrook, IL 60521 USA. EM ray.lloyd@hsc.utah.edu FU NCI NIH HHS [1 R01 CA66759] NR 22 TC 4 Z9 4 U1 0 U2 0 PU LIPPINCOTT WILLIAMS & WILKINS PI PHILADELPHIA PA 530 WALNUT ST, PHILADELPHIA, PA 19106-3621 USA SN 0017-9078 EI 1538-5159 J9 HEALTH PHYS JI Health Phys. PD DEC PY 2000 VL 79 IS 6 BP 722 EP 727 DI 10.1097/00004032-200012000-00019 PG 6 WC Environmental Sciences; Public, Environmental & Occupational Health; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Environmental Sciences & Ecology; Public, Environmental & Occupational Health; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA 375GT UT WOS:000165391700016 PM 11089810 ER PT J AU Korte, N Adams, SM AF Korte, N Adams, SM TI Measurements of suborganism level responses are needed to delineate selenium's role in the decline of western native fishes SO HUMAN AND ECOLOGICAL RISK ASSESSMENT LA English DT Letter ID CRITERIA C1 Oak Ridge Natl Lab, Grand Junct Off, Grand Junction, CO 81503 USA. Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Korte, N (reprint author), Oak Ridge Natl Lab, Grand Junct Off, 2597 B 3-4 Rd, Grand Junction, CO 81503 USA. NR 9 TC 0 Z9 0 U1 1 U2 2 PU CRC PRESS LLC PI BOCA RATON PA 2000 CORPORATE BLVD NW, JOURNALS CUSTOMER SERVICE, BOCA RATON, FL 33431 USA SN 1080-7039 J9 HUM ECOL RISK ASSESS JI Hum. Ecol. Risk Assess. PD DEC PY 2000 VL 6 IS 6 BP 1139 EP 1140 PG 2 WC Biodiversity Conservation; Environmental Sciences SC Biodiversity & Conservation; Environmental Sciences & Ecology GA 392FF UT WOS:000166399800016 ER PT J AU Fung, J Weier, HUG Goldberg, JD Pedersen, RA AF Fung, J Weier, HUG Goldberg, JD Pedersen, RA TI Multilocus genetic analysis of single interphase cells by spectral imaging SO HUMAN GENETICS LA English DT Article ID RAPID PRENATAL-DIAGNOSIS; FLUORESCENCE INSITU HYBRIDIZATION; IN-SITU HYBRIDIZATION; CHROMOSOME-ABNORMALITIES; HUMAN OOCYTES; PREIMPLANTATION DIAGNOSIS; SPONTANEOUS-ABORTIONS; DNA AMPLIFICATION; MATERNAL BLOOD; HUMAN EMBRYOS AB Numerical chromosome aberrations are detrimental to early embryonic, fetal and perinatal development of mammals. When fetuses carrying a chromosomal imbalance survive to term, an aberrant gene dosage typically leads to stillbirth or causes a severely altered phenotype. Aneuploidy of any of the 24 chromosomes will negatively impact on human development, and a preimplantation and prenatal genetic diagnosis test should thus score as many chromosomes as possible. Since cells available for analysis are likely to be in interphase, we set out to develop a rapid enumeration procedure based on hybridization of chromosome-specific probes and spectral imaging detection. The probe set was chosen to allow the simultaneous enumeration of ten chromosome types and was expected to detect more than 70% of all numerical chromosome aberrations responsible for spontaneous abortions, i.e., human chromosomes 9, 13, 14, 15, 16, 18, 21, 22, X, and Y. Cell fixation protocols were optimized to achieve the desired detection sensitivity and reproducibility. We were able to resolve and identify ten separate chromosomal signals in interphase nuclei from different types of cells, including lymphocytes, uncultured amniocytes, and blastomeres. In summary, this study demonstrates the strength of spectral imaging, allowing us to construct partial spectral imaging karyotypes for individual interphase cells by assessing the number of each of the target chromosome types. C1 Univ Calif San Francisco, Dept Obstet Gynecol & Reprod Sci, Reprod Genet Unit, San Francisco, CA 94143 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Life Sci Div 74 157, Berkeley, CA 94720 USA. RP Fung, J (reprint author), Univ Calif San Francisco, Dept Obstet Gynecol & Reprod Sci, Reprod Genet Unit, Box 0720,533 Parnassus Ave, San Francisco, CA 94143 USA. FU NIEHS NIH HHS [5-T32-ES07106-17] NR 46 TC 22 Z9 24 U1 0 U2 2 PU SPRINGER-VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 USA SN 0340-6717 J9 HUM GENET JI Hum. Genet. PD DEC PY 2000 VL 107 IS 6 BP 615 EP 622 DI 10.1007/s004390000416 PG 8 WC Genetics & Heredity SC Genetics & Heredity GA 389QC UT WOS:000166248400011 PM 11153916 ER PT J AU Miller, EK Deadrick, FJ AF Miller, EK Deadrick, FJ TI Visualizing near-field energy flow and radiation SO IEEE ANTENNAS AND PROPAGATION MAGAZINE LA English DT Article DE visualization; electric fields; magnetic fields; electromagnetic radiation; dipole antennas ID SCATTERING AB Computed near-field values of Poynting's Vector and electric and magnetic field intensities for a linear dipole are displayed in a way that aids visualization of the radiation process. The fields are computed for time-harmonic excitation, but are shown as a function of time to demonstrate the spatial ebb and flow of the fields around the dipole. By this means, the distinction between near and radiation fields is made clearer, and the shedding of energy by the dipole can be observed(2). C1 Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP 3225 Calle Celestial, Santa Fe, NM 87501 USA. EM e.miller@ieee.org; fdeadrick@home.com NR 16 TC 6 Z9 6 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855-4141 USA SN 1045-9243 EI 1558-4143 J9 IEEE ANTENN PROPAG M JI IEEE Antennas Propag. Mag. PD DEC PY 2000 VL 42 IS 6 BP 46 EP 54 DI 10.1109/74.894181 PG 9 WC Engineering, Electrical & Electronic; Telecommunications SC Engineering; Telecommunications GA 390PT UT WOS:000166306100006 ER PT J AU Schoenwald, DA AF Schoenwald, DA TI AUVs: In space, air, water, and on the ground SO IEEE CONTROL SYSTEMS MAGAZINE LA English DT Editorial Material C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Schoenwald, DA (reprint author), Sandia Natl Labs, POB 5800,MS 1004, Albuquerque, NM 87185 USA. NR 6 TC 55 Z9 56 U1 0 U2 3 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0272-1708 J9 IEEE CONTR SYST MAG JI IEEE Control Syst. Mag. PD DEC PY 2000 VL 20 IS 6 BP 15 EP 18 DI 10.1109/MCS.2000.887445 PG 4 WC Automation & Control Systems SC Automation & Control Systems GA 380EL UT WOS:000165686100004 ER PT J AU Yu, A Takahashi, H AF Yu, A Takahashi, H TI Multiphoton stimulated Compton laser SO IEEE JOURNAL OF QUANTUM ELECTRONICS LA English DT Article DE Compton scattering; free electron laser; intense laser beam; multiphoton; perturbation; quantum electrodynamics; relativistic electron beam ID GAMMA-RAY SOURCE; SCATTERING; RADIATION AB When Compton backscattering (head to head collisions) arises between a relativistic electron beam and one of two intense counterpropagating laser beams, electrons are mainly scattered by the laser beam from the reverse direction and can hardly interact with the other laser beam propagating in the same direction. Thus, the interaction of electrons with the latter laser beam, which induces stimulated Compton scattering, can he treated as a perturbation. With perturbation theory, we calculate the probability of stimulated emission and absorption-of the photons by electrons in two intense counterpropagating laser beams, The results demonstrate that stimulated emission or absorption is significant only if the momenta of photons and the energy Of the electron satisfy certain condition. We also formulate the gain coefficient of the multiphoton Stimulated Compton laser, which is sensitive to the intensity of the pumping laser and the energy spread of the electron beam. C1 Tsing Hua Univ, Dept Phys, Beijing 100084, Peoples R China. Brookhaven Natl Lab, Adv Technol Dept, Upton, NY 11973 USA. RP Yu, A (reprint author), Tsing Hua Univ, Dept Phys, Beijing 100084, Peoples R China. NR 18 TC 0 Z9 0 U1 1 U2 5 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0018-9197 J9 IEEE J QUANTUM ELECT JI IEEE J. Quantum Electron. PD DEC PY 2000 VL 36 IS 12 BP 1402 EP 1406 DI 10.1109/3.892559 PG 5 WC Engineering, Electrical & Electronic; Optics; Physics, Applied SC Engineering; Optics; Physics GA 390UU UT WOS:000166316100008 ER PT J AU Gopinathan, V Long, J Polla, D AF Gopinathan, V Long, J Polla, D TI Special issue on the 2000 ISSCC: Analog, Communication, Imaging, MEMS, and display circuits SO IEEE JOURNAL OF SOLID-STATE CIRCUITS LA English DT Editorial Material C1 Broadcom Corp, Irvine, CA 92619 USA. Univ Toronto, Dept Elect & Comp Engn, Toronto, ON M5S 3G4, Canada. Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. Univ Minnesota, Minneapolis, MN 55455 USA. RP Gopinathan, V (reprint author), Broadcom Corp, Irvine, CA 92619 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0018-9200 J9 IEEE J SOLID-ST CIRC JI IEEE J. Solid-State Circuit PD DEC PY 2000 VL 35 IS 12 BP 1756 EP 1759 PG 4 WC Engineering, Electrical & Electronic SC Engineering GA 387BQ UT WOS:000166100600001 ER PT J AU Nantista, CD Tantawi, SG AF Nantista, CD Tantawi, SG TI A compact, planar, eight-port waveguide power divider/combiner: The cross potent superhybrid SO IEEE MICROWAVE AND GUIDED WAVE LETTERS LA English DT Article DE divider/combiner; hybrid; phased array; waveguide AB In this letter, we present a novel four-way divider/combiner in rectangular waveguide. The design is completely two-dimensional (2-D) in the h-plane, with eight-fold mirror symmetry, and is based on a recent four-port hybrid design [6], Tn combining mode, it can function as a phased array with four inputs and four outputs, The planar nature of this design provides advantages, such as the freedom to increase the waveguide height beyond the over-moding limit in order to reduce field strengths. Along with its open geometry, this makes it ideal for high-power applications where rf break down is a concern. Design criteria, held-solver simulation results, and prototype measurements are presented. C1 Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. Cairo Univ, Commun & Elect Dept, Giza, Egypt. RP Nantista, CD (reprint author), Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. NR 9 TC 13 Z9 17 U1 1 U2 4 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 1051-8207 J9 IEEE MICROW GUIDED W JI IEEE Microw. Guided Wave Lett. PD DEC PY 2000 VL 10 IS 12 BP 520 EP 522 DI 10.1109/75.895089 PG 3 WC Engineering, Electrical & Electronic SC Engineering GA 394EC UT WOS:000166510300004 ER PT J AU Larson, MC Coldren, CW Spruytte, SG Petersen, HE Harris, JS AF Larson, MC Coldren, CW Spruytte, SG Petersen, HE Harris, JS TI Low-threshold oxide-confined GaInNAs long wavelength vertical cavity lasers SO IEEE PHOTONICS TECHNOLOGY LETTERS LA English DT Article DE long wavelength lasers on GaAs; semiconductor lasers; VCSELs; vertical-cavity surface-emitting lasers ID SURFACE-EMITTING LASER; OPERATION AB We report, for the first time, room temperature continuous-wave (CW) operation of GaInNAs vertical-cavity surface-emitting laser diodes emitting at a wavelength of 1.2 mum and grown all-epitaxially in a single step on a GaAs substrate, Oxide-apertured devices demonstrated CW threshold currents as low as 1 mA, slope efficiency above 0.045 W/A, and thermal impedance of 1.24 K/mW. Larger sized devices exhibited pulsed threshold current density of 2-2.5 kA/cm(2) and slope efficiency above 0.09 W/A. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. Stanford Univ, Solid State & Photon Lab, Stanford, CA 94305 USA. RP Larson, MC (reprint author), Univ Calif Lawrence Livermore Natl Lab, L-222, Livermore, CA 94551 USA. NR 10 TC 23 Z9 23 U1 0 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 1041-1135 J9 IEEE PHOTONIC TECH L JI IEEE Photonics Technol. Lett. PD DEC PY 2000 VL 12 IS 12 BP 1598 EP 1600 DI 10.1109/68.896319 PG 3 WC Engineering, Electrical & Electronic; Optics; Physics, Applied SC Engineering; Optics; Physics GA 397AK UT WOS:000166670600002 ER PT J AU Sarti, A de Solorzano, CO Lockett, S Malladi, R AF Sarti, A de Solorzano, CO Lockett, S Malladi, R TI A geometric model for 3-D confocal image analysis SO IEEE TRANSACTIONS ON BIOMEDICAL ENGINEERING LA English DT Article DE cytology; differential geometry; dynamic surfaces; image processing; level sets; Riemannian geometry; segmentation; surface evolution ID THICK TISSUE-SECTIONS; CELL-NUCLEI; CYTOMETRY; SEGMENTATION; MICROSCOPY; CURVATURE AB In this paper, we use partial-differential-equation-based filtering as a preprocessing add post processing strategy for computer-aided cytology, We wish to accurately extract and classify. the shapes of nuclei from confocal microscopy images, which is a prerequisite to an accurate quantitative intranuclear (genotypic and phenotypic) and internuclear (tissue structure) analysis of tissue and cultured specimens. First, we study the use of a geometry-driven edge-preserving image smoothing mechanism before nuclear segmentation. We show how this biter outperforms other widely-used filters in that it provides higher edge fidelity. Then we apply the same filter,,vith a different initial condition, to smooth nuclear surfaces and obtain sub-pixel accuracy. Finally we use another instance of the geometrical filter to correct for misinterpretations of the nuclear surface by the segmentation algorithm. Our prefiltering and post filtering nicely complements our initial segmentation strategy, in that it provides substantial and measurable improvement in the definition of the nuclear surfaces. C1 Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. RP Sarti, A (reprint author), Univ Calif Berkeley, Lawrence Berkeley Natl Lab, MS 50A-1148,1 Cyclotron Rd, Berkeley, CA 94720 USA. RI Ortiz de Solorzano, Carlos/G-3278-2010 OI Ortiz de Solorzano, Carlos/0000-0001-8720-0205 FU NCI NIH HHS [CA-67412] NR 35 TC 54 Z9 60 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 0018-9294 J9 IEEE T BIO-MED ENG JI IEEE Trans. Biomed. Eng. PD DEC PY 2000 VL 47 IS 12 BP 1600 EP 1609 PG 10 WC Engineering, Biomedical SC Engineering GA 378VU UT WOS:000165606500007 PM 11125595 ER PT J AU Dullweber, T Rau, U Contreras, MA Noufi, R Schock, HW AF Dullweber, T Rau, U Contreras, MA Noufi, R Schock, HW TI Photogeneration and carrier recombination in graded gap Cu(In, Ga)Se-2 solar cells SO IEEE TRANSACTIONS ON ELECTRON DEVICES LA English DT Article DE bandgap; chalcopyrite compounds; charge carrier processes; conversion efficiency; photovoltaic cell materials; thin-film devices ID BAND-GAP; CHALCOPYRITES AB We investigate photogeneration and carrier recombination in Cu(In, Ga)Se-2 based thin-film solar cells with graded gap absorbers, The graded gap in the absorbers is obtained by variation of the Ga/In ratio during the coevaporation process from elemental sources. The devices exhibit conversion efficiencies up to eta = 16.7%, In these graded gap devices, the Open circuit voltage depends on that bandgap which corresponds to the Ga content close to the absorber surface (i.e., the bandgap in the space charge region). In contrast, the short circuit current density relates to the overall minimum of the bandgap in the graded gap structure. We show that in our graded gap devices, two different bandgaps, one for recombination and one for photogeneration, are experimentally realized. C1 Univ Stuttgart, Inst Phys Elekt, D-70569 Stuttgart, Germany. Natl Renewable Energy Lab, Golden, CO 80401 USA. RP Dullweber, T (reprint author), Univ Stuttgart, Inst Phys Elekt, D-70569 Stuttgart, Germany. RI Rau, Uwe/G-2256-2011 OI Rau, Uwe/0000-0003-3526-3081 NR 24 TC 42 Z9 43 U1 0 U2 11 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0018-9383 J9 IEEE T ELECTRON DEV JI IEEE Trans. Electron Devices PD DEC PY 2000 VL 47 IS 12 BP 2249 EP 2254 PG 6 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA 378BN UT WOS:000165561900003 ER PT J AU Hisamoto, D Lee, WC Kedzierski, J Takeuchi, H Asano, K Kuo, C Anderson, E King, TJ Bokor, J Hu, CM AF Hisamoto, D Lee, WC Kedzierski, J Takeuchi, H Asano, K Kuo, C Anderson, E King, TJ Bokor, J Hu, CM TI FinFET - A self-aligned double-gate MOSFET scalable to 20 nm SO IEEE TRANSACTIONS ON ELECTRON DEVICES LA English DT Article DE fully depleted SOI; MOSFET; poly SiGe; short-channel effect ID DEVICE TECHNOLOGY AB MOSFETs with gate length down to 17 nm are reported. To suppress the short channel effect, a novel self-aligned double-gate MOSFET, FinFET, is proposed, By using boron-doped Si0.4Ge0.6 as a gate material, the desired threshold voltage was achieved for the ultrathin body device. The quasiplanar nature of this new variant of the vertical double-gate MOSFETs can be fabricated relatively easily using the conventional planar MOSFET process technologies. C1 Hitachi Ltd, Cent Res Lab, Tokyo 1858601, Japan. Univ Calif Berkeley, Dept Elect Engn & Comp Sci, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Hisamoto, D (reprint author), Hitachi Ltd, Cent Res Lab, Tokyo 1858601, Japan. RI Bokor, Jeffrey/A-2683-2011 NR 13 TC 715 Z9 722 U1 31 U2 265 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0018-9383 J9 IEEE T ELECTRON DEV JI IEEE Trans. Electron Devices PD DEC PY 2000 VL 47 IS 12 BP 2320 EP 2325 PG 6 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA 378BN UT WOS:000165561900013 ER PT J AU Hsu, JS AF Hsu, JS TI Direct control of air-gap flux in permanent-magnet machines SO IEEE TRANSACTIONS ON ENERGY CONVERSION LA English DT Article DE field weakening; field control; permanent-magnet (PM) machines; motors; generators; electric vehicle; drives ID MOTOR AB A new field weakening and adjustment technology for PM machines by direct control of air-gap fluxes is introduced, This new technology requires no current decomposition by the inverter eliminating the need for a position sensor. Demagnetization, which normally occurs during field weakening, does not occur with this new method. The field-weakening ratio can reach 10:1 or higher. This technology is robust and particularly useful for, but not limited to, electric vehicle drives and PM generators. C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Hsu, JS (reprint author), Oak Ridge Natl Lab, POB 2009,MS 8038, Oak Ridge, TN 37831 USA. NR 5 TC 22 Z9 23 U1 0 U2 3 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0885-8969 J9 IEEE T ENERGY CONVER JI IEEE Trans. Energy Convers. PD DEC PY 2000 VL 15 IS 4 BP 361 EP 365 DI 10.1109/60.900493 PG 5 WC Energy & Fuels; Engineering, Electrical & Electronic SC Energy & Fuels; Engineering GA 399QU UT WOS:000166824500001 ER PT J AU Va'vra, J AF Va'vra, J TI Particle identification using the dE/dx and the Cherenkov light detection methods in high energy physics SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT Nuclear Science Symposium (NSS) CY OCT 26-28, 1999 CL SEATTLE, WASHINGTON ID HELIUM GAS-MIXTURES; HERA-B RICH; RELATIVISTIC RISE; IONIZATION LOSS; DRIFT CHAMBERS; II DETECTOR; PERFORMANCE; COUNTER; SLD AB This paper deals with two particle identification methods: dE/dx and Cherenkov detection. The dE/dx method is the most common technique used in conjunction with tracking in gaseous detectors. We systematically compare existing dE/dx data with various predictions available in the literature and judge the overall consistency. To my knowledge, this comparison was not done to date. There are two Cherenkov light emission detection techniques: the threshold and the Ring imaging methods. We want to discuss the recent trend in these techniques. C1 Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. RP Va'vra, J (reprint author), Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. NR 75 TC 0 Z9 0 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 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD DEC PY 2000 VL 47 IS 6 BP 1764 EP 1774 DI 10.1109/TNS.2000.914443 PN 1 PG 11 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA 402MG UT WOS:000166991500005 ER PT J AU Xie, XB Cho, HS Chien, CY Liang, GW Huang, W Li, Z AF Xie, XB Cho, HS Chien, CY Liang, GW Huang, W Li, Z TI New designs of silicon pixel detectors fabricated from normal and oxygen-enriched silicon substrates SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT Nuclear Science Symposium (NSS) CY OCT 26-28, 1999 CL SEATTLE, WASHINGTON ID CHARGES N-EFF; RESISTIVITY AB New designs of silicon pixel detectors have been developed for more radiation-hard CMS forward pixel sensors. The new designs differ from our previous ones in that the guard rings on the n(+) side are replaced with a single wide (640 mum) n(+) implant, and the n(+) side and the edge region of the p(+) side are grounded, giving more graded potential distribution over the guard rings after irradiation. Thus, these designs have advantages for safe operation of the detectors at a high depletion voltage and for stability of readout chips. All designs were fabricated from normal and oxygen-enriched silicon substrates, and the radiation hardness effects for neutron (1 MeV equivalent) and proton (24 GeV) irradiation of these detectors were compared. Other electrical characteristics of these detectors such as leakage current, potential distribution over the guard rings and full depletion voltage were obtained using standard measurement techniques (I-V. V-V and TCT) before and after irradiation. C1 Johns Hopkins Univ, Dept Phys & Astron, Baltimore, MD 21218 USA. Brookhaven Natl Lab, Instrumentat Div, Upton, NY 11973 USA. Yonsei Univ, Coll Hlth Sci, Dept Med Engn, Wonju 220710, South Korea. RP Xie, XB (reprint author), Johns Hopkins Univ, Dept Phys & Astron, Baltimore, MD 21218 USA. NR 8 TC 2 Z9 2 U1 0 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD DEC PY 2000 VL 47 IS 6 BP 1807 EP 1811 DI 10.1109/23.914450 PN 1 PG 5 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA 402MG UT WOS:000166991500012 ER PT J AU Park, IJ Kim, JG Kim, HK Hong, WS Han, SH Perez-Mendez, V Kadyk, J Wenzel, W Joo, KS AF Park, IJ Kim, JG Kim, HK Hong, WS Han, SH Perez-Mendez, V Kadyk, J Wenzel, W Joo, KS TI Columnar cesium iodide (CsI) and micro-hole arrays for use in gas avalanche detectors SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT Nuclear Science Symposium (NSS) CY OCT 26-28, 1999 CL SEATTLE, WASHINGTON ID SECONDARY-EMISSION; X-RAYS AB The characteristics of a columnar CsI layer with gas multiplication was investigated by using beta rays from a Sr-90 source. This layer is intended for use as the primary electron source in any gas avalanche microdetector to avoid severe performance loss by the oblique angle of the incident charged particle. It was initially thought that the columnar structure might provide a larger detection efficiency than a planar CsI layer, because of the many surface crossings of incident particle for the columnar geometry. The columnar CsI study was performed in a thin parallel-plane structure, which has a 50-500 mum gas gap between a columnar CsI cathode and metal anode. We discuss the secondary emission and electric fields in the columnar structure, and explain why, based upon field simulation and experimental results, this approach does not succeed in this case. New ideas are presented for driftless gas avalanche detectors insensitive to the angle of incidence. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Div Phys, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Engn, Berkeley, CA 94720 USA. MyonJi Univ, Dept Phys, Young In 449728, South Korea. Korea Adv Inst Sci & Technol, Dept Nucl Engn, Taejon 305701, South Korea. Kyungpook Natl Univ, Dept Phys, Taegu 702701, South Korea. RP Park, IJ (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Div Phys, Berkeley, CA 94720 USA. NR 10 TC 3 Z9 3 U1 0 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD DEC PY 2000 VL 47 IS 6 BP 1820 EP 1824 DI 10.1109/23.914452 PN 1 PG 5 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA 402MG UT WOS:000166991500014 ER PT J AU Shaw, T Nelson, C Wesson, T AF Shaw, T Nelson, C Wesson, T TI The design of the CDF Run 2 calorimetry readout module SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT Nuclear Science Symposium (NSS) CY OCT 26-28, 1999 CL SEATTLE, WASHINGTON AB The CDF Calorimetry Readout module, called the ADMEM, has been designed to contain both the analog circuitry which digitizes the phototube charge pulses, and the digital logic which supports the readout of the results through the CDF Run 2 DAQ system. The ADMEM module is a 9Ux400mm VMEbus module, which is housed in a CDF VMEbus VIPA crate. The ADMEM must support near deadtimeless operation, with data being digititized and stored for possible readout every 132ns or 7.6 MHz. This paper will discuss the implementation of the analog and digital portions of the ADMEM module, and how the board was laid out to avoid the coupling of digital noise into the analog circuitry. C1 Fermi Natl Accelerator Lab, Batavia, IL 60510 USA. RP Shaw, T (reprint author), Fermi Natl Accelerator Lab, POB 500, Batavia, IL 60510 USA. NR 11 TC 8 Z9 8 U1 0 U2 2 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD DEC PY 2000 VL 47 IS 6 BP 1834 EP 1838 DI 10.1109/23.914455 PN 1 PG 5 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA 402MG UT WOS:000166991500017 ER PT J AU Dabrowski, W Anghinolfi, F Buttar, C Cindro, V Clark, AG Dawson, I Dorfan, D Dubbs, T Falconer, N French, M Greenall, A Grillo, AA Happer, R Jarron, P Kaplon, J Kudlaty, J Kramberger, G Lacasta, C LaMarra, D Macina, D Mandic, I Mikuz, M Meddeler, G Milgrome, O Niggli, H Phillips, PW Roe, S Smith, A Spieler, H Spencer, E Szczygiel, R Weilhammer, P Wolter, M Zsenei, A AF Dabrowski, W Anghinolfi, F Buttar, C Cindro, V Clark, AG Dawson, I Dorfan, D Dubbs, T Falconer, N French, M Greenall, A Grillo, AA Happer, R Jarron, P Kaplon, J Kudlaty, J Kramberger, G Lacasta, C LaMarra, D Macina, D Mandic, I Mikuz, M Meddeler, G Milgrome, O Niggli, H Phillips, PW Roe, S Smith, A Spieler, H Spencer, E Szczygiel, R Weilhammer, P Wolter, M Zsenei, A TI Design and performance of the ABCD chip for the binary readout of silicon strip detectors in the ATLAS Semiconductor Tracker SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT Nuclear Science Symposium (NSS) CY OCT 26-28, 1999 CL SEATTLE, WASHINGTON AB The ABCD design is a single chip implementation of the binary readout architecture for silicon strip detectors in the ATLAS Semiconductor Tracker. The prototype chip has been manufactured successfully in the DMILL process. In the paper we present the design of the chip and the measurement results. The basic analogue performance of the ABCD design has been evaluated using a prototype SCT module equipped with the ABCD chips. The digital performance has been evaluated using a general purpose IC tester. The measurements confirmed that all blocks of the ABCD design are fully functional and the chips meet all basic requirements of the SCT. Wafer screening has been performed using a customised wafer tester. The set-up allows measurements of all analogue and digital parameters at the nominal clock frequency of 40 MHz as well as evaluation of speed margins for the digital blocks. The ABCD chips have been irradiated separately with X-rays up to a total dose of 10 Mrad, with neutrons from a nuclear reactor up to a fluence of 2x10(14) n/cm(2) and with a high energy proton beam up to a fluence of 3x10(14) p/cm(2). The test that were performed confirmed satisfactory radiation hardness of the DMILL technology and of the ABCD design up to the radiation levels expected in the SCT. C1 CERN, Geneva, Switzerland. Univ Sheffield, Sheffield, S Yorkshire, England. Jozef Stefan Inst, Ljubljana, Slovenia. Univ Geneva, Geneva, Switzerland. UCSC, SCIPP, Santa Cruz, CA USA. Rutherford Appleton Lab, Didcot OX11 0QX, Oxon, England. Univ Liverpool, Liverpool L69 3BX, Merseyside, England. MPI, Munich, Germany. IFIC, Valencia, Spain. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. Inst Phys Nucl, Krakow, Poland. RP Dabrowski, W (reprint author), UMM, Fac Phys & Nucl Tech, Krakow, Poland. RI Szczygiel, Robert/B-5662-2011; Buttar, Craig/D-3706-2011; Wolter, Marcin/A-7412-2012; OI Lacasta, Carlos/0000-0002-2623-6252 NR 6 TC 34 Z9 34 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 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD DEC PY 2000 VL 47 IS 6 BP 1843 EP 1850 DI 10.1109/23.914457 PN 1 PG 8 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA 402MG UT WOS:000166991500019 ER PT J AU De Geronimo, G O'Connor, P Grosholz, J AF De Geronimo, G O'Connor, P Grosholz, J TI A generation of CMOS readout ASICs for CZT detectors SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT Nuclear Science Symposium (NSS) CY OCT 26-28, 1999 CL SEATTLE, WASHINGTON ID SOLID-STATE DETECTORS; FRONT-END; OPERATIONAL-AMPLIFIERS; ELECTRONICS; CIRCUIT; SIGNALS; SYSTEM; MODEL; CDTE AB As a result of a cooperation between Brookhaven National Laboratory and eV Products a generation of high performance readout ASICs was developed. The ASICs, realized in CMOS 0.5 mum technology, are available in several different versions, single or multi-channel and with unipolar or bipolar shaper, in view of their use in research, spectroscopy, medical, safeguard and industrial applications. Four innovative circuit solutions are implemented in the ASICs: (i) a high linearity compensated continuous reset system which self-adapts to a wide range of detector leakage currents with minimum noise contribution; (ii) a high order shaper realized by using the follow-the-leader feedback (FLF) approach; (iii) a class AB rail-to-rail output stage with high driving capability; (iv) a baseline holder (BLH) for the baseline stabilization. The basic structure of the ASICs, a description of the circuit solutions and the preliminary experimental results are reported. C1 Brookhaven Natl Lab, Instrumentat Div, Upton, NY 11973 USA. EV Prod, Saxonburg, PA 16056 USA. RP De Geronimo, G (reprint author), Brookhaven Natl Lab, Instrumentat Div, Bldg 535B, Upton, NY 11973 USA. NR 44 TC 72 Z9 72 U1 2 U2 5 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD DEC PY 2000 VL 47 IS 6 BP 1857 EP 1867 DI 10.1109/23.914460 PN 1 PG 11 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA 402MG UT WOS:000166991500021 ER PT J AU Jagadish, U Britton, CL Ericson, MN Bryan, WL Schwarz, WG Read, ME Kroeger, RA AF Jagadish, U Britton, CL Ericson, MN Bryan, WL Schwarz, WG Read, ME Kroeger, RA TI A preamplifier-shaper-stretcher Integrated Circuit system for use with gernanium strip detectors SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT Nuclear Science Symposium (NSS) CY OCT 26-28, 1999 CL SEATTLE, WASHINGTON ID CMOS PEAK DETECT; HOLD CIRCUIT; SPECTROSCOPY; CHIP AB A 16-channel integrated Circuit readout electronics chip is being developed for use with a germanium strip detector. Such a system will provide superior energy resolution with 2-dimensional imaging in a single instrument that can be used for X-ray imaging and nuclear line gamma-ray spectroscopy. As part of the total ASIC development, prototype ICs of a typical channel have been designed, fabricated and tested. These integrated circuits include a low-noise, variable gain, preamplifier circuit that can detect both positive and negative going input charges, a 4-pole pulse shaper with variable peaking times and a stretcher circuit that can do a peak detect and hold for the different peaking times. The integrated circuits are fabricated in a 1.2 micron n-well CMOS process. The noise performance for this system was measured to be 185erms +14e/pF for a 2 mus peaking time and gain at similar to 200mV/fC. Linearity measurements in both inverting and non-inverting modes of operation were approximately +/-1%. Peaking times from 0.5 microseconds to 8 microseconds and gain adjustments to get up to 400mV/fC per channel were done through digital switching. C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. Phys Sci Inc, Alexandria, VA USA. USN, Res Lab, Washington, DC 20375 USA. RP Jagadish, U (reprint author), Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. NR 8 TC 7 Z9 7 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 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD DEC PY 2000 VL 47 IS 6 BP 1868 EP 1871 PN 1 PG 4 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA 402MG UT WOS:000166991500022 ER PT J AU Dezillie, B Li, Z Eremin, V Chen, W Zhao, LJ AF Dezillie, B Li, Z Eremin, V Chen, W Zhao, LJ TI The effect of oxygen impurities on radiation hardness of FZ silicon detectors for HEP after neutron, proton and gamma irradiation SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT Nuclear Science Symposium (NSS) CY OCT 26-28, 1999 CL SEATTLE, WASHINGTON ID CHARGES N-EFF; PARTICLE DETECTORS; DAMAGE AB Radiation hardness for fast neutrons, high energy protons and Co-60 gamma rays of planar detectors processed from highly oxygenated silicon detectors obtained by using the high temperature (1200 degreesC), long time (> 200 hours) oxidation technology, are compared with standard silicon detectors. For fast neutron irradiation it is found that there is no advantage of using highly oxygenated silicon FZ detectors as compared to the standard ones in terms of full depletion voltage degradation as measured a few days after radiation. For a gamma ray dose of 250 Mrad, the standard detectors of all resistivities (1 k Omega cm to 5.6 k Omega cm) invert the space charge sign, while there is little change in space charge density for oxygenated ones. For proton irradiation, the rate in full depletion voltage increase (beta) is 2.3 times less than that for neutron irradiation. The difference in radiation hardness is explained in terms of effect of radiation induced disorder regions (clusters of vacancies) on the introduction rates of divacancies in the oxygenated silicon. C1 Brookhaven Natl Lab, Upton, NY 11973 USA. Russian Acad Sci, AF Ioffe Phys Tech Inst, St Petersburg 194021, Russia. RP Dezillie, B (reprint author), Brookhaven Natl Lab, Upton, NY 11973 USA. NR 11 TC 35 Z9 35 U1 0 U2 3 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD DEC PY 2000 VL 47 IS 6 BP 1892 EP 1897 DI 10.1109/23.914465 PN 1 PG 6 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA 402MG UT WOS:000166991500026 ER PT J AU Shapira, D Lewis, TA AF Shapira, D Lewis, TA TI A two-dimensional beam profile monitor based on residual gas ionization SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT 1998 Nuclear Science Symposium (NSS) CY NOV 08-14, 1998 CL TORONTO, CANADA SP IEEE AB A two-dimensional beam profile monitor based on tracking the ionization of the residual gas molecules in the evacuated beam pipe is described. Tracking in position and time of the ions and electrons produced in the ionization enables simultaneous position sampling in three dimensions. Special features which make it possible to sample very low beam currents were employed. C1 Oak Ridge Natl Lab, Div Phys, Oak Ridge, TN 37831 USA. Oak Ridge Natl Lab, Instrumentat & Control Div, Oak Ridge, TN 37831 USA. RP Shapira, D (reprint author), Oak Ridge Natl Lab, Div Phys, Oak Ridge, TN 37831 USA. NR 10 TC 0 Z9 0 U1 0 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD DEC PY 2000 VL 47 IS 6 BP 1969 EP 1973 DI 10.1109/23.903830 PN 2 PG 5 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA 402MK UT WOS:000166991900002 ER PT J AU Shapira, D Lewis, TA AF Shapira, D Lewis, TA TI Position of ion impact determined via detection of secondary electrons SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT 1998 Nuclear Science Symposium (NSS) CY NOV 08-14, 1998 CL TORONTO, CANADA SP IEEE ID PLATE DETECTOR; MICROCHANNEL AB The factors affecting the performance of a Position Sensitive Timing Detector (PSTD), which is based on detecting secondary electrons ejected from a foil by the passing ion in a position sensitive detection device, were investigated. We studied effects of multiple scattering in the foil, electron transport from the foil to the micro-channel plate (MCP) detector surface, and signal processing hardware. We conclude that, for detectors with foil-to-MCP distance of 5-10 cm, which use only electrostatic acceleration, electron transport limits the devices currently in use to resolution worse than 2 mm (FWHM). C1 Oak Ridge Natl Lab, Div Phys, Oak Ridge, TN 37830 USA. Oak Ridge Natl Lab, Div Instrumentat & Controls, Oak Ridge, TN 37830 USA. RP Shapira, D (reprint author), Oak Ridge Natl Lab, Div Phys, Oak Ridge, TN 37830 USA. NR 15 TC 0 Z9 0 U1 0 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD DEC PY 2000 VL 47 IS 6 BP 1974 EP 1978 DI 10.1109/23.903831 PN 2 PG 5 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA 402MK UT WOS:000166991900003 ER PT J AU David, G Kistenev, E White, S Woody, C Bazilevsky, A Belikov, S Kochetkov, V Onuchin, V Usachev, A AF David, G Kistenev, E White, S Woody, C Bazilevsky, A Belikov, S Kochetkov, V Onuchin, V Usachev, A TI Pattern recognition in the PHENIX PbSc electromagnetic calorimeter SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT 1998 Nuclear Science Symposium (NSS) CY NOV 08-14, 1998 CL TORONTO, CANADA SP IEEE AB The pattern recognition algorithm for the PHENIX PbSc electromagnetic calorimeters are presented. The algorithm is based upon energy and impact angle dependent description of the electromagnetic shower shape as measured in the test beam and reproduced in GEANT simulation. The efficiency of the pattern recognition for identification of single and multiple showers is studied and discussed. C1 Brookhaven Natl Lab, Upton, NY 11973 USA. Inst High Energy Phys, Protvino, Russia. RP David, G (reprint author), Brookhaven Natl Lab, Upton, NY 11973 USA. NR 6 TC 5 Z9 5 U1 0 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD DEC PY 2000 VL 47 IS 6 BP 1982 EP 1986 DI 10.1109/23.903833 PN 2 PG 5 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA 402MK UT WOS:000166991900005 ER PT J AU Tanaka, Y Hara, H Ebisu, K Hibino, M Matsumoto, T Sakaguchi, T Kikuchi, J Winterberg, AL Walker, JW Frank, S Moscone, C Jones, JP Young, GR Oyama, K Hamagaki, H AF Tanaka, Y Hara, H Ebisu, K Hibino, M Matsumoto, T Sakaguchi, T Kikuchi, J Winterberg, AL Walker, JW Frank, S Moscone, C Jones, JP Young, GR Oyama, K Hamagaki, H TI Front-end readout system for PHENIX RICH SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT 1998 Nuclear Science Symposium (NSS) CY NOV 08-14, 1998 CL TORONTO, CANADA SP IEEE ID DETECTOR AB A front-end readout system with a custom backplane and custom circuit modules has been developed for the RICH subsystem of the PHENIX experiment. The design specifications and test results of the backplane and the modules are presented in this paper. In the module design, flexibility for modification is maximized through the use of Complex Programmable Logic Devices. In the backplane design, a source-synchronous bus architecture is adopted for the data and control bus. The transfer speed of the backplane has reached 640 Mbyte/s with a 128-bit data bus. Total transaction time is estimated to be less than 30 mus per event when this system is used in the experiment. This result indicates that the performance satisfies the data-rate requirement of the PHENIX experiment. C1 Nagasaki Inst Appl Sci, Nagasaki 8510193, Japan. Waseda Univ, Tokyo 1698555, Japan. Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. Univ Tokyo, CNS, Tokyo 1880002, Japan. RP Tanaka, Y (reprint author), Nagasaki Inst Appl Sci, Nagasaki 8510193, Japan. RI HAMAGAKI, HIDEKI/G-4899-2014 NR 9 TC 0 Z9 0 U1 0 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD DEC PY 2000 VL 47 IS 6 BP 1995 EP 2002 DI 10.1109/23.903835 PN 2 PG 8 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA 402MK UT WOS:000166991900007 ER PT J AU Cancelo, GIE Zimmermann, S AF Cancelo, GIE Zimmermann, S TI Modeling and simulation of a readout architecture for pixel detectors SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT 1998 Nuclear Science Symposium (NSS) CY NOV 08-14, 1998 CL TORONTO, CANADA SP IEEE AB This paper analyzes in detail some theoretical aspects in the modeling of a proposed readout architecture for pixel detectors. The readout architecture is designed for a chip containing about 3000 pixels of 50 mum x 400 mum. The main objective is to get the maximum pixel hit readout with the minimum probability of hit loss. The readout architecture is modeled as a Markov stochastic process. The pixel front-end and readout are simulated and tested with Monte Carlo data. The simulations allow to optimize the communication channel bandwidths and local buffering. The probability of system overflow of the simulated system is compared with the one obtained by modeling. C1 Natl Univ La Plata, Fermilab, La Plata, Argentina. Fermilab, Batavia, IL USA. RP Cancelo, GIE (reprint author), Natl Univ La Plata, Fermilab, La Plata, Argentina. NR 12 TC 0 Z9 0 U1 0 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD DEC PY 2000 VL 47 IS 6 BP 2007 EP 2013 DI 10.1109/23.903837 PN 2 PG 7 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA 402MK UT WOS:000166991900009 ER PT J AU Hansen, RR Reeder, PL Peurrung, AJ Stromswold, DC AF Hansen, RR Reeder, PL Peurrung, AJ Stromswold, DC TI Neutron-gamma discrimination in plastic scintillators SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT 1998 Nuclear Science Symposium (NSS) CY NOV 08-14, 1998 CL TORONTO, CANADA SP IEEE AB Direct detection of fast neutrons prior to moderation offers increased performance at lower cost for future neutron detection technologies. Neutron detection by proton recoil in plastic scintillators could provide this capability if efficient techniques for discrimination against gamma events were available. We describe two possible approaches to neutron/gamma discrimination; one based on digital pulse processing to differentiate pulse types and the other based on low density scintillators to lengthen the time interval between multiple interactions. C1 Pacific NW Natl Lab, Richland, WA 99352 USA. RP Hansen, RR (reprint author), Pacific NW Natl Lab, Richland, WA 99352 USA. NR 6 TC 10 Z9 10 U1 1 U2 4 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD DEC PY 2000 VL 47 IS 6 BP 2024 EP 2028 DI 10.1109/23.903840 PN 2 PG 5 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA 402MK UT WOS:000166991900012 ER PT J AU Bailly, P Beigbeder, C Bernier, R Breton, D Bonneaud, G Caceres, T Chase, R Chauveau, J Del Buono, L Dohou, F Ducorps, A Gastaldi, F Genat, JF Hrisoho, A Imbert, P Lebbolo, H Matricon, P Oxoby, G Renard, C Roos, L Sen, S Thiebaux, C Truong, K Tocut, V Vasileiadis, G Va'Vra, J Verderi, M Warner, D Wilsons, RJ Wormser, G Zhang, B Zomer, F AF Bailly, P Beigbeder, C Bernier, R Breton, D Bonneaud, G Caceres, T Chase, R Chauveau, J Del Buono, L Dohou, F Ducorps, A Gastaldi, F Genat, JF Hrisoho, A Imbert, P Lebbolo, H Matricon, P Oxoby, G Renard, C Roos, L Sen, S Thiebaux, C Truong, K Tocut, V Vasileiadis, G Va'Vra, J Verderi, M Warner, D Wilsons, RJ Wormser, G Zhang, B Zomer, F TI The DIRC Front-end electronics chain for BaBar. SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT 1998 Nuclear Science Symposium (NSS) CY NOV 08-14, 1998 CL TORONTO, CANADA SP IEEE AB Recent results from the Front-End electronics of the Detector of Internally Reflected Cerenkov light (DIRC) for the BaBar experiment at SLAG (Stanford, USA) are presented. It measures to better than Ins the arrival time of Cerenkov photoelectrons detected in a 11,000 phototubes array and their amplitude spectra. It mainly comprises 64-channel DIRC Front-End Boards (DFB) equipped with eight full-custom analog chips performing zero-cross discrimination with 2 mV threshold and pulse shaping, four full-custom digital time to digital chips (TDC) for timing measurements with 500 ps binning and a readout logic selecting hits in the trigger window, and DIRC Crate Controller cards (DCC) serializing the data collected from up to 16 DFBs onto a 1.2 Gb/s optical link. Extensive test results of the pre-production chips will be presented, as well as system tests. C1 Univ Paris 06, Lab Phys Nucl & Hautes Energies, CNRS, IN2P3, F-75252 Paris, France. Univ Paris 07, Lab Phys Nucl & Hautes Energies, CNRS, IN2P3, F-75252 Paris, France. Univ Paris 11, Accelerateur Lineaire Lab, CNRS, IN2P3, F-91405 Orsay, France. Ecole Polytech, CNRS, IN2P3, Lab Phys Nucl & Hautes Energies, F-91128 Palaiseau, France. Stanford Univ, Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. Colorado State Univ, Ft Collins, CO 80523 USA. RP Bailly, P (reprint author), Univ Paris 06, Lab Phys Nucl & Hautes Energies, CNRS, IN2P3, F-75252 Paris, France. OI Wilson, Robert/0000-0002-8184-4103 NR 8 TC 2 Z9 2 U1 0 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD DEC PY 2000 VL 47 IS 6 BP 2106 EP 2113 DI 10.1109/23.903856 PN 2 PG 8 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA 402MK UT WOS:000166991900028 ER PT J AU Pandey, SU Bellwied, R Beuttenmueller, R Caines, H Chen, W DiMassimo, D Dyke, H Elliot, D Grau, M Hoffmann, GW Humanic, TJ Jensen, P Kotov, IV Kraner, HW Kuczewski, P Leonhardt, W Li, Z Liaw, CJ Lo Curto, G Lynn, D Middelkamp, P Minor, R Nehmeh, S Ott, G Pinelli, D Pruneau, C Rykov, V Schambach, J Sedlmeir, J Sheen, J Soja, R Stefani, D Sugarbaker, E Takahashi, J Wilson, WK AF Pandey, SU Bellwied, R Beuttenmueller, R Caines, H Chen, W DiMassimo, D Dyke, H Elliot, D Grau, M Hoffmann, GW Humanic, TJ Jensen, P Kotov, IV Kraner, HW Kuczewski, P Leonhardt, W Li, Z Liaw, CJ Lo Curto, G Lynn, D Middelkamp, P Minor, R Nehmeh, S Ott, G Pinelli, D Pruneau, C Rykov, V Schambach, J Sedlmeir, J Sheen, J Soja, R Stefani, D Sugarbaker, E Takahashi, J Wilson, WK TI The 15 layer silicon drift detector tracker in experiment 896. SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT 1998 Nuclear Science Symposium (NSS) CY NOV 08-14, 1998 CL TORONTO, CANADA SP IEEE ID STAR EXPERIMENT AB Large linear silicon drift detectors have been developed and are in production for use in several experiments. Recently 15 detectors were used as a tracking device in BNL-AGS heavy ion experiment(E896). The detectors were successfully operated in a 6.2T magnetic field. The behavior of the detectors, such as drift uniformity, resolution, and charge collection efficiency are presented. The effect of the environment on the detector performance is discussed. Some results from the experimetal run are presented. The detectors performed well in an experimental enviromental. This is the first tracking application of these detectors. C1 Wayne State Univ, Detroit, MI 48201 USA. Brookhaven Natl Lab, Upton, NY 11973 USA. Ohio State Univ, Columbus, OH 43210 USA. Univ Texas, Austin, TX 78712 USA. Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. Protvino High Energy Phys Inst, Protvino 142284, Russia. Univ Sao Paulo, Sao Paulo, Brazil. RP Pandey, SU (reprint author), Wayne State Univ, Detroit, MI 48201 USA. RI Takahashi, Jun/B-2946-2012 OI Takahashi, Jun/0000-0002-4091-1779 NR 13 TC 0 Z9 0 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 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD DEC PY 2000 VL 47 IS 6 BP 2114 EP 2118 DI 10.1109/23.903857 PN 2 PG 5 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA 402MK UT WOS:000166991900029 ER PT J AU Dodd, PE Shaneyfelt, MR Walsh, DS Schwank, JR Hash, GL Loemker, RA Draper, BL Winokur, PS AF Dodd, PE Shaneyfelt, MR Walsh, DS Schwank, JR Hash, GL Loemker, RA Draper, BL Winokur, PS TI Single-event upset and snapback in silicon-on-insulator devices and integrated circuits SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT IEEE Nuclear and Space Radiation Effects Conference (NSREC) CY JUL 24-28, 2000 CL RENO, NEVADA SP IEEE ID CHARGE COLLECTION; SOI TRANSISTORS; HEAVY-IONS; TECHNOLOGIES; SIMULATION; LATCH; SIMOX AB The characteristics of ion-induced charge collection and single-event upset are studied in silicon-on-insulator (SOI) transistors and circuits with various body tie structures. Impact ionization effects, including single-event snapback, are shown to be very important. Focused ion microbeam experiments are used to find single- event snapback drain voltage thresholds in n-channel SOI transistors as a function of device width. Three-dimensional device simulations are used to determine single-event upset and snapback thresholds in SOI SRAMs, and to study design tradeoffs for various body-tie structures. A window of vulnerability to single-event snapback is shown to exist below the single event upset threshold. The presence of single-event snapback in commercial SOI SRAMs is confirmed through broadbeam ion testing, and implications for hardness assurance testing of SOI integrated circuits are discussed. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Dodd, PE (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. NR 19 TC 32 Z9 32 U1 0 U2 3 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD DEC PY 2000 VL 47 IS 6 BP 2165 EP 2174 DI 10.1109/23.903749 PN 3 PG 10 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA 402MN UT WOS:000166992300003 ER PT J AU Schwank, JR Shaneyfelt, MR Dodd, PE Ferlet-Cavrois, V Loemker, RA Winokur, PS Fleetwood, DM Paillet, P Leray, JL Draper, BL Witczak, SC Riewe, LC AF Schwank, JR Shaneyfelt, MR Dodd, PE Ferlet-Cavrois, V Loemker, RA Winokur, PS Fleetwood, DM Paillet, P Leray, JL Draper, BL Witczak, SC Riewe, LC TI Correlation between Co-60 and X-ray radiation-induced charge buildup in silicon-on-insulator buried oxides SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT IEEE Nuclear and Space Radiation Effects Conference (NSREC) CY JUL 24-28, 2000 CL RENO, NEVADA SP IEEE ID MOS DEVICES; HARDNESS-ASSURANCE; IRRADIATIONS; TRANSISTORS; DEPENDENCE; MOSFETS; ISSUES AB Large differences in charge buildup in SOI buried oxides are observed for X-ray and Co-60 irradiations of SIMOX and Unibond transistors. The Co-60 response is typically worse than the X-ray response. These results are consistent with expectations derived from previous work on the relative charge yield versus field in thick oxides. The effects of bias configuration and substrate type on charge buildup and hardness assurance issues are explored via experiments and simulation. The worst-case bias condition is found to be either the off-state or transmission gate configuration. Simulations of the buried oxide electric field in the various bias configurations are used to illustrate the factors that affect charge transport and trapping in the buried oxides. Hardness assurance implications are discussed. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. CEA, DAM Ile France, Bruyeres Le Chatel, France. Vanderbilt Univ, Nashville, TN 37235 USA. RP Schwank, JR (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. NR 24 TC 44 Z9 50 U1 3 U2 10 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD DEC PY 2000 VL 47 IS 6 BP 2175 EP 2182 DI 10.1109/23.903750 PN 3 PG 8 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA 402MN UT WOS:000166992300004 ER PT J AU Ferlet-Cavrois, V Colladant, T Paillet, P Leray, JL Musseau, O Schwank, JR Shaneyfelt, MR Pelloie, JL de Poncharra, JD AF Ferlet-Cavrois, V Colladant, T Paillet, P Leray, JL Musseau, O Schwank, JR Shaneyfelt, MR Pelloie, JL de Poncharra, JD TI Worst-case bias during total dose irradiation of SOI transistors SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT IEEE Nuclear and Space Radiation Effects Conference (NSREC) CY JUL 24-28, 2000 CL RENO, NEVADA SP IEEE AB The worst case bias during total dose irradiation of partially depleted SOI transistors from two technologies is correlated to the device architecture. Experiments and simulations are used to analyze SOI back transistor threshold voltage shift and charge trapping in the buried oxide. C1 CEA, DIF, F-91680 Bruyeres Le Chatel, France. Sandia Natl Labs, Albuquerque, NM 87185 USA. LETI, CEA, DTA, F-38054 Grenoble, France. RP Ferlet-Cavrois, V (reprint author), CEA, DIF, BP12, F-91680 Bruyeres Le Chatel, France. NR 18 TC 66 Z9 73 U1 3 U2 5 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD DEC PY 2000 VL 47 IS 6 BP 2183 EP 2188 DI 10.1109/23.903751 PN 3 PG 6 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA 402MN UT WOS:000166992300005 ER PT J AU Marka, Z Singh, SK Wang, W Lee, SC Kavich, J Glebov, B Rashkeev, SN Karmarkar, AP Albridge, RG Pantelides, ST Schrimpf, RD Fleetwood, DM Tolk, NH AF Marka, Z Singh, SK Wang, W Lee, SC Kavich, J Glebov, B Rashkeev, SN Karmarkar, AP Albridge, RG Pantelides, ST Schrimpf, RD Fleetwood, DM Tolk, NH TI Characterization of X-ray radiation damage in Si/SiO2 structures using second-harmonic generation SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT IEEE Nuclear and Space Radiation Effects Conference (NSREC) CY JUL 24-28, 2000 CL RENO, NEVADA SP IEEE ID 2ND-HARMONIC GENERATION; SI-SIO2 INTERFACE; BORDER TRAPS; MOS OXIDES; DEVICES; CAPACITORS; SILICON; CENTERS; SIO2 AB We report the first application of second-harmonic generation (SHG) measurements for the characterization of X-ray radiation damage in Si/SiO2 structures. The main advantage of this experimental technique is that it is noninvasive, contactless, and sensitive to the electric field at the interface. Interaction of intense 800 mn femtosecond laser pulses with Si/SiO2 structures results in electron-hole pair creation in the Si, multiphoton carrier injection and second-harmonic generation. The time-dependent second-harmonic (doubled frequency) signal is a measure of the dynamic electric field at the interface. This dynamic field is created and altered by unequal electron-hole injection into the oxide, trapping/detrapping of charges, and carrier recombination processes. We find that the SHG response from Si/SiO2 samples before and after X-ray irradiation is significantly different. Thus, SHG is a promising technique for the characterization of radiation damage in Si/SiO2 structures. In particular, SHG is especially useful in characterizing damage in ultrathin oxide layers, for which conventional electrical measurements may not be sufficiently sensitive to the kinds of defects observable via optical methods. C1 Vanderbilt Univ, Dept Phys & Astron, Nashville, TN 37235 USA. Oak Ridge Natl Lab, Div Solid State, Oak Ridge, TN 37831 USA. Vanderbilt Univ, Dept Elect Engn & Comp Sci, Nashville, TN 37235 USA. RP Marka, Z (reprint author), Vanderbilt Univ, Dept Phys & Astron, 221 Kirkland Hall, Nashville, TN 37235 USA. RI Schrimpf, Ronald/L-5549-2013 OI Schrimpf, Ronald/0000-0001-7419-2701 NR 25 TC 10 Z9 10 U1 1 U2 8 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD DEC PY 2000 VL 47 IS 6 BP 2256 EP 2261 DI 10.1109/23.903762 PN 3 PG 6 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA 402MN UT WOS:000166992300016 ER PT J AU Pantelides, ST Rashkeev, SN Buczko, R Fleetwood, DM Schrimpf, RD AF Pantelides, ST Rashkeev, SN Buczko, R Fleetwood, DM Schrimpf, RD TI Reactions of hydrogen with Si-SiO2 interfaces SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT IEEE Nuclear and Space Radiation Effects Conference (NSREC) CY JUL 24-28, 2000 CL RENO, NEVADA SP IEEE ID ELECTRON-SPIN-RESONANCE; POSITIVE CHARGE; MOBILE PROTONS; HOLE TRAPS; RADIATION; SILICON; OXIDES; SIO2-FILMS; DEVICES; CENTERS AB Radiation experiments have established that H+ released in SiO2 migrates to the Si-SiO2 interface where it can induce new defects. For oxides exposed first to high-temperature annealing and then to molecular hydrogen, mobile positive charge believed to be H+ can be cycled to and from the interface by reversing the oxide electric field. We report first-principles calculations that identify atomic-scale mechanisms for the two types of behavior and the conditions that are necessary for each. Si-Si bonds an the oxide side, i.e., "suboxide bonds," can trap H+ in deep wells with an asymmetric barrier (1.5 eV on the Si side, 1 eV on the SiO2 side). In radiation experiments these centers can act as fixed positive charge. In the mobile-positive-charge experiments, the protons can be cycled between opposing Si-SiO2 interfaces if the density of suboxide bonds is high. C1 Vanderbilt Univ, Dept Phys & Astron, Nashville, TN 37235 USA. Oak Ridge Natl Lab, Div Solid State, Oak Ridge, TN 37831 USA. Polish Acad Sci, Inst Semicond Phys, Warsaw, Poland. Vanderbilt Univ, Dept Elect Engn & Comp Sci, Nashville, TN 37235 USA. RP Pantelides, ST (reprint author), Vanderbilt Univ, Dept Phys & Astron, 221 Kirkland Hall, Nashville, TN 37235 USA. RI Schrimpf, Ronald/L-5549-2013 OI Schrimpf, Ronald/0000-0001-7419-2701 NR 35 TC 96 Z9 96 U1 0 U2 22 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD DEC PY 2000 VL 47 IS 6 BP 2262 EP 2268 DI 10.1109/23.903763 PN 3 PG 7 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA 402MN UT WOS:000166992300017 ER PT J AU Witczak, SC Lacoe, RC Shaneyfelt, MR Mayer, DC Schwank, JR Winokur, PS AF Witczak, SC Lacoe, RC Shaneyfelt, MR Mayer, DC Schwank, JR Winokur, PS TI Implications of radiation-induced dopant deactivation for npn bipolar junction transistors SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT IEEE Nuclear and Space Radiation Effects Conference (NSREC) CY JUL 24-28, 2000 CL RENO, NEVADA SP IEEE ID SHALLOW-ACCEPTOR IMPURITIES; INTERFACE-STATE GENERATION; SINGLE-CRYSTAL SILICON; OXIDE-SEMICONDUCTOR STRUCTURES; LOW ELECTRIC-FIELDS; GROUP-III ACCEPTORS; GATE MOS DEVICES; LOW-DOSE-RATES; HYDROGEN PASSIVATION; HARDNESS-ASSURANCE AB Metal-oxide-silicon capacitors fabricated in a bipolar process were examined for densities of oxide trapped charge, interface traps and deactivated substrate accepters following high-dose-rate irradiation at 100 degreesC. Accepter neutralization near the Si surface occurs most efficiently for small irradiation biases in depletion. The bias dependence is consistent with compensation and passivation mechanisms involving the drift of H+ ions in the oxide and Si layers and the availability of holes in the Si depletion region. The capacitor data were used to simulate the impact of accepter neutralization on the current gain of an irradiated npn bipolar transistor Neutralized accepters near the base surface enhance current gain degradation associated with radiation-induced oxide trapped charge and interface traps by increasing base recombination, The additional recombination results from the convergence of carrier concentrations in the base and increased sensitivity of the base to oxide trapped charge. The enhanced gain degradation is moderated by increased electron injection from the emitter These results suggest that accepter neutralization may complicate hardness assurance test methods for linear circuits, which are based on elevated temperature irradiations. C1 Sandia Natl Labs, Dept 1761, Albuquerque, NM 87185 USA. Aerospace Corp, Elect Technol Ctr, Los Angeles, CA 90009 USA. RP Witczak, SC (reprint author), Sandia Natl Labs, Dept 1761, POB 5800, Albuquerque, NM 87185 USA. NR 79 TC 27 Z9 27 U1 1 U2 10 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD DEC PY 2000 VL 47 IS 6 BP 2281 EP 2288 DI 10.1109/23.903766 PN 3 PG 8 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA 402MN UT WOS:000166992300020 ER PT J AU Fleetwood, DM Riewe, LC Winokur, PS Sexton, FW AF Fleetwood, DM Riewe, LC Winokur, PS Sexton, FW TI Dielectric breakdown of thin oxides during ramped current-temperature stress SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT IEEE Nuclear and Space Radiation Effects Conference (NSREC) CY JUL 24-28, 2000 CL RENO, NEVADA SP IEEE ID THERMALLY STIMULATED CURRENT; IRRADIATED MOS CAPACITORS; INDUCED LEAKAGE CURRENT; SILICON DIOXIDE FILMS; EVENT GATE RUPTURE; IONIZING-RADIATION; DEGRADATION; RELIABILITY; SIO2; SIO2-FILMS AB Dielectric breakdown in thin gate oxides is studied with a bias-temperature ramp technique. Research grade 6.5 nm oxides with Al gates show variable current-temperature (I-T) response with increasing electric field, consistent,vith a wide breakdown distribution at room temperature. Industrial grade 7.0 nm thermal and N2O-nitrided oxides show well-behaved I-T plots, consistent with narrower breakdown distributions at room temperature. In all cases, temperature-to-breakdown decreases with increasing electric field, Charge-to-breakdown Q(BD) levels at elevated temperatures exceed values observed in previous work, especially for the 7 nm nitrided oxides. No significant effect of radiation exposure on high-field oxide conduction or breakdown is observed under positive, zero, or negative radiation bias for the thermal and nitrided oxides, up to 20 Mrad(SiO2), Detectable radiation induced leakage current is observed only for heavy-ion equivalent doses greater than 10 Mrad(SiO2), These results suggest that the long-term reliability of high quality gate oxides may not be significantly degraded by radiation exposure at levels typical of system operation. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Fleetwood, DM (reprint author), Vanderbilt Univ, Dept Elect Engn & Comp Sci, 221 Kirkland Hall, Nashville, TN 37235 USA. NR 31 TC 5 Z9 5 U1 1 U2 3 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD DEC PY 2000 VL 47 IS 6 BP 2305 EP 2310 DI 10.1109/23.903769 PN 3 PG 6 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA 402MN UT WOS:000166992300023 ER PT J AU Barnaby, HJ Cirba, CR Schrimpf, RD Fleetwood, DM Pease, RL Shaneyfelt, MR Turflinger, T Krieg, JF Maher, MC AF Barnaby, HJ Cirba, CR Schrimpf, RD Fleetwood, DM Pease, RL Shaneyfelt, MR Turflinger, T Krieg, JF Maher, MC TI Origins of total-dose response variability in linear bipolar microcircuits SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT IEEE Nuclear and Space Radiation Effects Conference (NSREC) CY JUL 24-28, 2000 CL RENO, NEVADA SP IEEE ID INDUCED GAIN DEGRADATION; IONIZING-RADIATION; INTEGRATED-CIRCUITS; TRANSISTORS; CHARGE; OXIDES AB LM111 voltage comparators exhibit a wide range of total-dose-induced degradation. Simulations show this variability may be a natural consequence of the low base doping of the substrate PNP (SPNP) input transistors. Low base doping increases the SPNPs collector to base breakdown voltage, current gain, and sensitivity to small fluctuations in the radiation-induced oxide defect densities. The build-up of oxide trapped charge (NOT) and interface traps (NIT) is shown to be a function of pre-irradiation bakes. Experimental data indicate that, despite its structural similarities to the LM111, irradiated input transistors of the LM124 operational amplifier do not exhibit the same sensitivity to variations in pre-irradiation thermal cycles. Further disparities in LM111 and LM124 responses may result from a difference in the oxide defect build-up in the two part types. Variations in processing, packaging, and circuit effects are suggested as potential explanations. C1 Vanderbilt Univ, Dept Elect Engn & Comp Sci, Nashville, TN 37235 USA. RLP Res, Albuquerque, NM 87122 USA. Sandia Natl Labs, Albuquerque, NM 87185 USA. NAVSEA Ctr, Crane, IN 47522 USA. RP Barnaby, HJ (reprint author), Vanderbilt Univ, Dept Elect Engn & Comp Sci, Nashville, TN 37235 USA. RI Schrimpf, Ronald/L-5549-2013 OI Schrimpf, Ronald/0000-0001-7419-2701 NR 23 TC 17 Z9 17 U1 1 U2 5 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD DEC PY 2000 VL 47 IS 6 BP 2342 EP 2349 DI 10.1109/23.903775 PN 3 PG 8 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA 402MN UT WOS:000166992300029 ER PT J AU Shaneyfelt, MR Schwank, JR Witczak, SC Fleetwood, DM Pease, RL Winokur, PS Riewe, LC Hash, GL AF Shaneyfelt, MR Schwank, JR Witczak, SC Fleetwood, DM Pease, RL Winokur, PS Riewe, LC Hash, GL TI Thermal-stress effects and enhanced low dose rate sensitivity in linear bipolar ICs SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT IEEE Nuclear and Space Radiation Effects Conference (NSREC) CY JUL 24-28, 2000 CL RENO, NEVADA SP IEEE ID INTERFACE-TRAP BUILDUP; LOW ELECTRIC-FIELDS; INTEGRATED-CIRCUITS; HARDNESS-ASSURANCE; IONIZING-RADIATION; GAIN DEGRADATION; SPACE ENVIRONMENTS; MOS DEVICES; BURN-IN; X-RAY AB A pre-irradiation elevated-temperature stress is shown to have a significant impact on the radiation response of a linear bipolar circuit. Thermal cycling can lead to part-to-part variability in the radiation response of circuits packaged from the same wafer. In addition, it is demonstrated that a pre-irradiation elevated-temperature stress can significantly impact the enhanced low dose rate sensitivity (ELDRS) of the LM111 voltage comparator. Thermal stress moderates and, in some cases, eliminates ELDRS, The data are consistent with space charge models. These results suggest that there may be a connection between the mechanisms responsible for thermal-stress effects and ELDRS in linear circuits. Implications of these results for hardness assurance testing and mechanisms are discussed. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. Vanderbilt Univ, Nashville, TN 37235 USA. RLP Res, Albuquerque, NM 87122 USA. RP Shaneyfelt, MR (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. NR 31 TC 51 Z9 51 U1 1 U2 6 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD DEC PY 2000 VL 47 IS 6 BP 2539 EP 2545 DI 10.1109/23.903805 PN 3 PG 7 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA 402MN UT WOS:000166992300059 ER PT J AU Lai, ST Singh, N Peratt, AL AF Lai, ST Singh, N Peratt, AL TI Space weather - Guest editorial SO IEEE TRANSACTIONS ON PLASMA SCIENCE LA English DT Editorial Material C1 USAF, Res Lab, Space Weather Ctr Excellence, Space Vehicles Directorate, Hanscom AFB, MA 01731 USA. Univ Alabama, Dept Elect & Comp Engn, Huntsville, AL 35899 USA. Univ Calif Los Alamos Natl Lab, Div Phys, Los Alamos, NM 87545 USA. RP Lai, ST (reprint author), USAF, Res Lab, Space Weather Ctr Excellence, Space Vehicles Directorate, Hanscom AFB, MA 01731 USA. NR 0 TC 0 Z9 0 U1 0 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0093-3813 J9 IEEE T PLASMA SCI JI IEEE Trans. Plasma Sci. PD DEC PY 2000 VL 28 IS 6 BP 1783 EP 1785 DI 10.1109/TPS.2000.902207 PG 3 WC Physics, Fluids & Plasmas SC Physics GA 403VP UT WOS:000167063400001 ER PT J AU Hesse, M Birn, J AF Hesse, M Birn, J TI Magnetic reconnection: Three-dimensional aspects and onset in the magnetotail SO IEEE TRANSACTIONS ON PLASMA SCIENCE LA English DT Article DE corona; kinetic and MHD; magnetic reconnection; magnetotail ID PARALLEL ELECTRIC-FIELDS; PARTICLE SIMULATION; GEOMAGNETIC TAIL; HYBRID SIMULATIONS; CURRENT SHEETS; DISSIPATION; ACCELERATION; EVOLUTION; COMPUTER; PLASMAS AB Magnetic reconnection is a fundamental plasma transport mechanism in space and laboratory plasmas. In recent years, much progress has been made in the understanding of the fundamentals of the reconnection process, including basic laws governing magnetic reconnection in three dimensions, the physical mechanisms providing the electric field in the dissipation region, and the onset of magnetic reconnection in the magnetotail of the Earth. This paper summarizes this progress and uses numerical simulations to illustrate the theoretical results in the framework of a solar and a magnetospheric example of magnetic reconnection. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RI Hesse, Michael/D-2031-2012 NR 51 TC 7 Z9 7 U1 0 U2 2 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855-4141 USA SN 0093-3813 EI 1939-9375 J9 IEEE T PLASMA SCI JI IEEE Trans. Plasma Sci. PD DEC PY 2000 VL 28 IS 6 BP 1887 EP 1902 DI 10.1109/27.902217 PG 16 WC Physics, Fluids & Plasmas SC Physics GA 403VP UT WOS:000167063400011 ER PT J AU Peratt, AL Verschuur, GL AF Peratt, AL Verschuur, GL TI Observation of the CIV effect in interstellar clouds: A speculation on the physical mechanism for their existence SO IEEE TRANSACTIONS ON PLASMA SCIENCE LA English DT Article DE CIV; electric space; interstellar clouds; plasma universe ID EMISSION PROFILE STRUCTURE; IONIZATION AB Observations of neutral hydrogen (HI) emission profiles produced by gas in the local interstellar medium are found to be characterized by four linewidth regimes. Dominant and pervasive features have widths on average of 5.2, 13, and 31 km/s, and a very broad component approximately 50 km/s nide. A striking coincidence exists between these linewidths and the magnitudes of the critical ionization velocities of the most abundant atomic species in interstellar space: 6 km/s for sodium and calcium; 13 km/s for carbon, oxygen, and nitrogen; 31 km/s fur helium; and 51 km/s for hydrogen. The data relate to observations near neutral hydrogen structures that are filamentary. C1 US DOE, Washington, DC 20585 USA. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Univ Memphis, Dept Phys, Memphis, TN 38152 USA. RP Peratt, AL (reprint author), US DOE, Washington, DC 20585 USA. NR 22 TC 9 Z9 9 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0093-3813 J9 IEEE T PLASMA SCI JI IEEE Trans. Plasma Sci. PD DEC PY 2000 VL 28 IS 6 BP 2122 EP 2127 DI 10.1109/27.902239 PG 6 WC Physics, Fluids & Plasmas SC Physics GA 403VP UT WOS:000167063400033 ER PT J AU Kwok, DTK Chu, PK Bilek, MMM Brown, IG Vizir, A AF Kwok, DTK Chu, PK Bilek, MMM Brown, IG Vizir, A TI Ion mean charge state in a biased vacuum arc plasma duct SO IEEE TRANSACTIONS ON PLASMA SCIENCE LA English DT Article DE ion charge states; plasma duct; vacuum arc sources ID CATHODIC ARC; DEPOSITION; TRANSPORT; FILTERS; COATINGS; FILMS AB Vacuum are or cathodic are metal plasma sources are attractive and convenient for depositing high-quality thin metal films and metallurgical coatings. It is a common practice to use a cursed magnetic filter duct to eliminate macroparticle contamination and to bias the duct wall with a positive voltage to enhance the throughput of the metal plasma. The metal plasma usually consists of several charge states and time-of-flight (TOF) experiments show that the mean charge state of the metal ions decreases with increasing bias and magnetic field applied to the filter duct. We also derive the throughput of ions with different charge states at different bias voltage and magnetic field by the particle-in-cell (PIC) method. The ion trajectory is simulated neglecting the influence of electron charge. Our results show that the simulated mean charge state displays a similar decreasing trend as the bias voltage and magnetic field strength are increased. Phenomena such as reduction of the mean charge state at high magnetic field strength and bias can be explained in terms of standalone multiply charged metal ions under the influences of magnetic and electric forces inside the filter ducts. C1 City Univ Hong Kong, Dept Phys & Mat Sci, Kowloon, Hong Kong, Peoples R China. Univ Cambridge, Dept Engn, Cambridge CB2 1PZ, England. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. Russian Acad Sci, Inst High Current Elect, Tomsk 634055, Russia. RP Kwok, DTK (reprint author), City Univ Hong Kong, Dept Phys & Mat Sci, Kowloon, Hong Kong, Peoples R China. RI Chu, Paul/B-5923-2013; Vizir, Alexey/R-2139-2016 OI Chu, Paul/0000-0002-5581-4883; Vizir, Alexey/0000-0002-9563-8650 NR 23 TC 5 Z9 5 U1 1 U2 2 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855-4141 USA SN 0093-3813 J9 IEEE T PLASMA SCI JI IEEE Trans. Plasma Sci. PD DEC PY 2000 VL 28 IS 6 BP 2194 EP 2201 DI 10.1109/27.902247 PG 8 WC Physics, Fluids & Plasmas SC Physics GA 403VP UT WOS:000167063400041 ER PT J AU Christlieb, AJ Hitchon, WNG Keiter, ER AF Christlieb, AJ Hitchon, WNG Keiter, ER TI A computational investigation of the effects of varying discharge geometry for an inductively coupled plasma SO IEEE TRANSACTIONS ON PLASMA SCIENCE LA English DT Article DE Boltzmann equation; complex geometry; convected scheme; fluid model; hybrid model; kinetic transport model; mobility; unstructured mesh ID NONLOCAL ELECTRON KINETICS; BOLTZMANN-EQUATION; UNIFORMITY; ARGON; MODEL AB In this paper, a numerical investigation of ionization and density profiles in a low pressure inductively coupled plasma (ICP) discharge is presented. ICP reactors have in recent years become a popular choice for semiconductor processing. To ensure high,yields, it is important to optimize process uniformity. Off-axis ionization can result in the hollowing of the density profile of the plasma, Previous numerical studies [Keiter (1996), Beale (1995), Mumken (1999). Kortshagen (1999)] have focused on electron kinetics and the resulting ionization rates as the main factor in producing nonuniform ion density profiles. Here rye extend some of the previous work to also examine the effects of the ion transport in detail. Two models are used for the study, The first model is a hybrid model that approximates electron transport by solving the Boltzmann transport equation (BTE) using a spatially dependent two-term spherical harmonic expansion (SHE), and neutral and ion transport with a simple fluid model, The second model is a new kinetic model for ion transport in complex geometry based on the convected scheme (CS). This model uses an "unstructured mesh" and "Long Lived Moving Cells." By using the CS model for ion transport, it is possible to investigate the limitations of the fluid model and issues pertinent to process uniformity which are not accessible to the fluid approximation, As the ratio between ion mean-free path and system size is often looked to as the key parameter for determining the applicability of a fluid model, the two parameters we have varied in this study are the reactor chamber height and the neutral temperature. Ion density profiles produced by. the fluid model are qualitatively similar to those of the kinetic ion model, although the kinetic model tends to produce more uniform ion density profiles, C1 Univ Wisconsin, Dept Elect & Comp Engn, Madison, WI 53706 USA. Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Christlieb, AJ (reprint author), Univ Wisconsin, Dept Elect & Comp Engn, 1415 Johnson Dr, Madison, WI 53706 USA. NR 30 TC 16 Z9 17 U1 1 U2 4 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0093-3813 J9 IEEE T PLASMA SCI JI IEEE Trans. Plasma Sci. PD DEC PY 2000 VL 28 IS 6 BP 2214 EP 2231 DI 10.1109/27.902250 PG 18 WC Physics, Fluids & Plasmas SC Physics GA 403VP UT WOS:000167063400044 ER PT J AU Goncharov, AA Protsenko, IM Yushkov, GY Brown, IG AF Goncharov, AA Protsenko, IM Yushkov, GY Brown, IG TI Manipulating large-area, heavy metal ion beams with a high-current electrostatic plasma lens SO IEEE TRANSACTIONS ON PLASMA SCIENCE LA English DT Article DE Intense ion beams; ion beams; ion focusing; plasma lens; plasma optics AB We describe some experimental investigations of the manipulation of high-current, targe-area beams of heavy metal ions using a high-current electrostatic plasma lens. Beams of carbon, copper, zinc, and tantalum ions (separately) were formed by a repetitively pulsed vacuum are ion source, with energy in the range about 10-140 keV beam current up to 0.5 A, initial beam diameter 10 cm, and pulse length 250 ms. The plasma lens was of IO-cm internal diameter and 20-cm length and had nine electrostatic ring electrodes rrilh potential applied to the central electrode of up to 7 kV: in the presence of a pulsed magnetic field of up to 800 Gauss, The current density profile of the focused beam was measured with a radially moveable, magnetically suppressed Faraday cup. The results show that the focal length of the lens and the profile of the transported beam can be controlled by variation of the lens magnetic field and electrode potential distribution. Under optimum operating conditions the ion beam current density at the focus was compressed bg; a factor of up to 31. We also carried out some preliminary observations of the effect of the plasma lens on the ion charge state distribution of the beam. Here we outline the principles underlying plasma lens operation and summarize the experimental observations we have made of the lens performance in this large-area, high-current regime. C1 NASU, Inst Phys, UA-03039 Kiev, Ukraine. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. Russian Acad Sci, Inst High Current Elect, Tomsk 634055, Russia. RP Goncharov, AA (reprint author), NASU, Inst Phys, 46 Prospect Nauki, UA-03039 Kiev, Ukraine. RI Yushkov, Georgy/O-8024-2015 OI Yushkov, Georgy/0000-0002-7615-6058 NR 13 TC 16 Z9 16 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0093-3813 J9 IEEE T PLASMA SCI JI IEEE Trans. Plasma Sci. PD DEC PY 2000 VL 28 IS 6 BP 2238 EP 2246 DI 10.1109/27.902252 PG 9 WC Physics, Fluids & Plasmas SC Physics GA 403VP UT WOS:000167063400046 ER PT J AU Han, L Trinkle, JC Li, ZX AF Han, L Trinkle, JC Li, ZX TI Grasp analysis as linear matrix inequality problems SO IEEE TRANSACTIONS ON ROBOTICS AND AUTOMATION LA English DT Article; Proceedings Paper CT Annual Meeting of the IEEE International Conference on Robotics and Automation CY MAY 10-15, 1999 CL DETROIT, MI SP IEEE DE convex programming; grasp analysis; force closure; force optimization; friction cones; linear matrix inequalities ID OPTIMAL FORCE DISTRIBUTION; CLOSURE GRASPS; OPTIMIZATION; CONSTRAINTS; EXISTENCE; FRICTION AB Three fundamental problems in the study of grasping and dextrous manipulation with multifingered robotic hands are as follows, a) Given a robotic hand and a grasp characterized by a set of contact points and the associated contact models, determine if the grasp has force closure. b) Given a grasp along with robotic hand kinematic structure and joint effort limit constraints, determine if the fingers are able to apply a specified resultant wrench on the object. c) Compute "optimal" contact forces if the answer to problem b) is affirmative. In this paper, based on an early result by Buss et al., which transforms the nonlinear friction cane constraints into positive definiteness constraints imposed on certainy symmetric matrices, we further cast the friction cone constraints into linear matrix inequalities (LMIs) and formulate all three of the problems stated above as a set of convex optimization problems involving LMIs, The latter problems have been extensively studied in optimization and control communities. Currently highly efficient algorithms with polynomial time complexity have been developed and made available. We perform numerical studies to show the simplicity and efficiency of the LMI formulation to the three grasp analysis problems. C1 Carnegie Mellon Univ, Dept Elect & Comp Engn, Inst Complex Engineered Syst, Pittsburgh, PA 15213 USA. Sandia Natl Labs, Albuquerque, NM 87185 USA. Hong Kong Univ Sci & Technol, Dept Elect & Elect Engn, Kowloon, Hong Kong, Peoples R China. RP Carnegie Mellon Univ, Dept Elect & Comp Engn, Inst Complex Engineered Syst, Pittsburgh, PA 15213 USA. EM lihan@cs.cmu.edu; jctrink@sandia.gov; eezxli@ee.ust.hk NR 37 TC 155 Z9 160 U1 1 U2 20 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855-4141 USA SN 1042-296X J9 IEEE T ROBOTIC AUTOM JI IEEE Trans. Robot. Autom. PD DEC PY 2000 VL 16 IS 6 BP 663 EP 674 DI 10.1109/70.897778 PG 12 WC Automation & Control Systems; Engineering, Electrical & Electronic; Robotics SC Automation & Control Systems; Engineering; Robotics GA 397GH UT WOS:000166684600004 ER PT J AU Dixon, WE Walker, ID Dawson, DM Hartranft, JP AF Dixon, WE Walker, ID Dawson, DM Hartranft, JP TI Fault detection for robot manipulators with parametric uncertainty: A prediction-error-based approach SO IEEE TRANSACTIONS ON ROBOTICS AND AUTOMATION LA English DT Article; Proceedings Paper CT IEEE International Conference on Robotics and Automation CY APR 24-28, 2000 CL SAN FRANCISCO, CA SP IEEE DE fault detection; nonlinear dynamics; prediction error; robot manipulator ID KINEMATICALLY REDUNDANT MANIPULATORS; JOINT FAILURES; TOLERANCE; DIAGNOSIS; SYSTEMS AB In this paper, we introduce a new approach to fault detection for robot manipulators. The technique, which is based on the isolation of fault signatures via filtered torque prediction error estimates, does not require measurements or estimates of manipulator acceleration as is the case with some previously suggested methods. The method is formally demonstrated to be robust under uncertainty in the robot parameters. Furthermore, an adaptive version of the algorithm is introduced, and shown to both improve coverage and significantly reduce detection times. The effectiveness of the approach is demonstrated by experiments with a two-joint manipulator system. C1 Clemson Univ, Dept Elect & Comp Engn, Clemson, SC 29634 USA. RP Oak Ridge Natl Lab, Knoxville, TN 37909 USA. EM ianw@ces.clemson.edu RI Dixon, Warren/F-5238-2015 OI Dixon, Warren/0000-0002-5091-181X NR 26 TC 70 Z9 71 U1 2 U2 14 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855-4141 USA SN 1042-296X J9 IEEE T ROBOTIC AUTOM JI IEEE Trans. Robot. Autom. PD DEC PY 2000 VL 16 IS 6 BP 689 EP 699 DI 10.1109/70.897780 PG 11 WC Automation & Control Systems; Engineering, Electrical & Electronic; Robotics SC Automation & Control Systems; Engineering; Robotics GA 397GH UT WOS:000166684600006 ER PT J AU Fodor, IK Stark, PB AF Fodor, IK Stark, PB TI Multitaper spectrum estimation for time series with gaps SO IEEE TRANSACTIONS ON SIGNAL PROCESSING LA English DT Article DE bootstrap; multitaper spectral analysis; solar oscillations; time series with gaps ID TERRESTRIAL FREE OSCILLATIONS; UNCERTAINTY AB Gaps in time series can produce spurious features in power spectrum estimates. These artifacts can be suppressed by averaging spectrum estimates obtained by first windowing the time series with a collection of orthogonal tapers. Such "multitaper' methods have been used for data without gaps since the early 1980s and for more general sampling schemes since the late 1980s, We introduce three families of tapers for time series with gaps. Two of the families solve optimization problems, They minimize bounds on different measures of bias. Computing them involves solving large eigenvalue problems with special structure that can be exploited to construct efficient algorithms. The third family solves no particular optimization problem but is inexpensive to compute and gives spectrum estimates that are quite similar to the other two for actual and simulated helioseismic data All three families of gap-adapted multitaper estimates have lower variance and bias than the periodogram, In simulations of helioseismic data with gaps, standard methods for constructing confidence intervals for multitaper spectrum estimates, including parametric approximations and resampling in the temporal and spectral domains, all failed to attain their nominal confidence level, We present a novel resampling technique that, in the same simulations, gave confidence intervals that attained the correct confidence level. C1 Univ Calif Lawrence Livermore Natl Lab, Ctr Appl Sci Comp, Livermore, CA 94551 USA. Univ Calif Berkeley, Space Sci Lab, Dept Stat, Berkeley, CA 94720 USA. Univ Calif Lawrence Livermore Natl Lab, Theoret Astrophys Ctr, Livermore, CA 94551 USA. RP Fodor, IK (reprint author), Univ Calif Lawrence Livermore Natl Lab, Ctr Appl Sci Comp, Livermore, CA 94551 USA. OI Stark, Philip/0000-0002-3771-9604 NR 33 TC 16 Z9 16 U1 0 U2 5 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 1053-587X J9 IEEE T SIGNAL PROCES JI IEEE Trans. Signal Process. PD DEC PY 2000 VL 48 IS 12 BP 3472 EP 3483 PG 12 WC Engineering, Electrical & Electronic SC Engineering GA 378AT UT WOS:000165559600020 ER PT J AU Apte, MG Fisk, WJ Daisey, JM AF Apte, MG Fisk, WJ Daisey, JM TI Associations between indoor CO2 concentrations and sick building syndrome symptoms in US office buildings: An analysis of the 1994-1996 BASE study data SO INDOOR AIR-INTERNATIONAL JOURNAL OF INDOOR AIR QUALITY AND CLIMATE LA English DT Article DE carbon dioxide; dose-response; sick building syndrome; multivariate logistic regression; office workers; ventilation AB Higher indoor concentrations of air pollutants due, in part, to lower ventilation rates are a potential cause of sick building syndrome (SBS) symptoms in office workers. The indoor carbon dioxide (CO2) concentration is an approximate surrogate for indoor concentrations of other occupant-generated pollutants and for ventilation rate per occupant. Using multivariate logistic regression (MLR) analyses, we evaluated the relationship between indoor CO2 concentrations and SBS symptoms in occupants from a probability sample of 41 U.S. office buildings. Two CO2 metrics were constructed: average workday indoor minus average outdoor CO2 (dCO(2), range 6-418 ppm), and maximum indoor 1-h moving average CO2 minus outdoor CO2 concentrations (dCO(2)MAX). MLR analyses quantified dCO(2)/SBS symptom associations, adjusting for personal and environmental factors. A dose-response relationship (p<0.05) with odds ratios per 100 ppm dCO(2) ranging from 1.2 to 1.5 for sore throat, nose/sinus, tight chest, and wheezing was observed. The dCO(2)MAX/SBS regression results were similar. C1 Lawrence Berkeley Lab, Indoor Environm Dept, Berkeley, CA 94720 USA. RP Apte, MG (reprint author), Lawrence Berkeley Lab, Indoor Environm Dept, 1 Cyclotron Rd, Berkeley, CA 94720 USA. NR 26 TC 109 Z9 110 U1 3 U2 20 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 DEC PY 2000 VL 10 IS 4 BP 246 EP 257 DI 10.1034/j.1600-0668.2000.010004246.x PG 12 WC Construction & Building Technology; Engineering, Environmental; Public, Environmental & Occupational Health SC Construction & Building Technology; Engineering; Public, Environmental & Occupational Health GA 372NF UT WOS:000165239200006 PM 11089329 ER PT J AU Heath, KD Cochran, HD AF Heath, KD Cochran, HD TI Electrodispersion for supercritical CO2-water phase contact SO INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH LA English DT Article; Proceedings Paper CT 5th International Symposium on Supercritical Fluids (ISSF 2000) CY APR, 2000 CL ATLANTA, GEORGIA ID GENERATION AB Supercritical carbon dioxide is a preferred solvent substitute in the chemical process industries, but processing that requires contact between CO2 and an aqueous phase has been hindered by the inefficient phase contact and high capital cost of conventional contactors. We examine the phase-contact performance of an electrodispersion contactor in this service. We have dispersed droplets of aqueous phases into supercritical CO2 using pulsed, high-intensity electric fields. Using small-angle laser light scattering, we characterized the mean droplet size as a function of operating conditions (liquid flow rate, field strength, frequency, temperature, and pressure) and observed operating regions that yield submicron-sized droplets. The effects of temperature and pressure on droplet size were correlated with the interfacial tension. Then, using the extraction of ethanol from a water-ethanol solution as a test system, we attempted to characterized mass transfer performance, but under maximum CO2 flow rate conditions of the downstream liquid condensers, mass transfer was equilibrium-limited in all cases. Because of the small droplet size and high interfacial area, the electrodispersion contactor offers the potential for achieving excellent mass transfer performance. The submicron-sized droplets were efficiently coalesced electrostatically, and negligible entrainment was observed. We anticipate that initial commercial applications might arise in the processing of small volumes of high-value substances in aqueous media such as might be found, for instance, in the pharmaceutical industry. C1 Oak Ridge Natl Lab, Div Chem Technol, Oak Ridge, TN 37831 USA. Univ Tennessee, Dept Chem Engn, Knoxville, TN 37996 USA. RP Cochran, HD (reprint author), Oak Ridge Natl Lab, Div Chem Technol, Oak Ridge, TN 37831 USA. NR 24 TC 5 Z9 5 U1 0 U2 3 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 DEC PY 2000 VL 39 IS 12 BP 4455 EP 4461 DI 10.1021/ie000117w PG 7 WC Engineering, Chemical SC Engineering GA 381GA UT WOS:000165752900005 ER PT J AU Benmore, CJ Tomberli, BL AF Benmore, CJ Tomberli, BL TI The structure of carbon dioxide around naphthalene investigated using H/D substitution in neutron diffraction SO INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH LA English DT Article; Proceedings Paper CT 5th International Symposium on Supercritical Fluids (ISSF 2000) CY APR, 2000 CL ATLANTA, GEORGIA ID SUPERCRITICAL FLUIDS; CO2; SCATTERING; SOLUBILITIES; EQUATION; VOLUMES AB The technique of hydrogen/deuterium substitution in neutron diffraction has been used to investigate the intermolecular structure of carbon dioxide saturated with naphthalene at supercritical pressure. The experiment was performed at P = 206 bar and T = 302 K, corresponding to a dilute concentration of approximately 1 C10H8 molecule to 110 CO2 molecules. Particular attention has been paid to the local structural environment of the hydrogen atoms through the extraction of the first-order neutron difference function. The neutron data show that eight nearest-neighbor CO2 molecules form a well-defined ring around the hydrogen atoms on the naphthalene molecule. Moreover, the CO2 molecules appear to be oriented perpendicular to the plane of the naphthalene molecule at a distance of r(H-CO2) = 3.3 Angstrom. C1 Rutherford Appleton Lab, ISIS Facil, CLRC, Didcot OX11 0QX, Oxon, England. Univ Guelph, Dept Phys, Guelph, ON N1G 2W1, Canada. RP Benmore, CJ (reprint author), Argonne Natl Lab, Intense Pulsed Neutron Source Div, 9700 S Cass Ave, Argonne, IL 60439 USA. OI Benmore, Chris/0000-0001-7007-7749 NR 20 TC 5 Z9 5 U1 0 U2 2 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 DEC PY 2000 VL 39 IS 12 BP 4491 EP 4495 DI 10.1021/ie000150i PG 5 WC Engineering, Chemical SC Engineering GA 381GA UT WOS:000165752900011 ER PT J AU Salaniwal, S Cui, ST Cochran, HD Cummings, PT AF Salaniwal, S Cui, ST Cochran, HD Cummings, PT TI Molecular dynamics simulation of reverse micelles in supercritical carbon dioxide SO INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH LA English DT Article; Proceedings Paper CT 5th International Symposium on Supercritical Fluids (ISSF 2000) CY APR, 2000 CL ATLANTA, GEORGIA ID SODIUM OCTANOATE MICELLE; WATER OIL INTERFACE; INTERMOLECULAR POTENTIALS; COMPUTER-SIMULATIONS; AQUEOUS-SOLUTION; MODEL MICELLES; MONTE-CARLO; SURFACTANT; MICROEMULSIONS; AGGREGATION AB We have studied surfactants and reverse micelles in supercritical carbon dioxide (SCO2) by molecular dynamics simulation using molecular potential models that we have developed for this purpose. In this work we present simulation results suggesting how varying the surfactant molecular architecture and chemistry may affect the structure and properties of reverse micelles in SCO2. We focus on a dichain surfactant, (C7H15)(C7F15)CHSO4-Na+, which forms reverse micelles with aqueous cores in SCO2. C1 Univ Tennessee, Dept Chem Engn, Knoxville, TN 37996 USA. Univ Tennessee, Dept Chem, Knoxville, TN 37996 USA. Univ Tennessee, Dept Comp Sci, Knoxville, TN 37996 USA. Oak Ridge Natl Lab, Div Chem Technol, Oak Ridge, TN 37831 USA. RP Cummings, PT (reprint author), Univ Tennessee, Dept Chem Engn, Knoxville, TN 37996 USA. RI Cummings, Peter/B-8762-2013 OI Cummings, Peter/0000-0002-9766-2216 NR 52 TC 35 Z9 35 U1 1 U2 7 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 DEC PY 2000 VL 39 IS 12 BP 4543 EP 4554 DI 10.1021/ie000144m PG 12 WC Engineering, Chemical SC Engineering GA 381GA UT WOS:000165752900021 ER PT J AU Nicholson, L Hojem, D Philippi, B AF Nicholson, L Hojem, D Philippi, B TI Salted away for a rainy day: A half-billion barrels of crude SO INTECH LA English DT Article C1 US Dept Energy, Strateg Petr Reserve, Washington, DC 20545 USA. RP Nicholson, L (reprint author), US Dept Energy, Strateg Petr Reserve, Washington, DC 20545 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU INSTRUMENT SOC AMER PI RES TRIANGLE PK PA 67 ALEXANDER DRIVE, RES TRIANGLE PK, NC 27709 USA SN 0192-303X J9 INTECH JI Intech PD DEC PY 2000 VL 47 IS 12 BP 32 EP 35 PG 4 WC Engineering, Multidisciplinary; Instruments & Instrumentation SC Engineering; Instruments & Instrumentation GA 381AC UT WOS:000165739300020 ER PT J AU Pike, LM Liu, CT AF Pike, LM Liu, CT TI The effect of vacancies on the environmental yield strength dependence of boron-free and boron-doped Fe-40Al SO INTERMETALLICS LA English DT Article DE iron aluminides, based on FeAl; environmental embrittlement; yield stress; defects : point defects ID HYDROGEN EMBRITTLEMENT; TENSILE PROPERTIES; AL-ALLOYS; FEAL; DUCTILITY; HARDNESS AB The effect of environment on the yield strength of boron-free and boron-doped Fe-40Al was considered. Special attention was given to the role of excess thermal vacancies. It was found that samples given a vacancy-relieving heat treatment had a 12% lower yield strength when tested in ail than when tested in vacuum. This was attributed to an environmental softening effect. However, samples with a large amount of quenched-in vacancies exhibited no environmental yield strength dependence. These observations were found in both the boron-free and boron-doped alloys. (C) 2000 Elsevier Science Ltd. All rights reserved. C1 Oak Ridge Natl Lab, Div Met & Ceram, Oak Ridge, TN 37831 USA. RP Pike, LM (reprint author), Oak Ridge Natl Lab, Div Met & Ceram, POB 2008, Oak Ridge, TN 37831 USA. NR 23 TC 12 Z9 12 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 DEC PY 2000 VL 8 IS 12 BP 1413 EP 1416 DI 10.1016/S0966-9795(00)00095-9 PG 4 WC Chemistry, Physical; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Chemistry; Materials Science; Metallurgy & Metallurgical Engineering GA 382KG UT WOS:000165821000008 ER PT J AU Nesbitt, SL Emerson, JA Bell, JP AF Nesbitt, SL Emerson, JA Bell, JP TI Coupling agent studies: reaction of thiol-containing esters with aluminum SO INTERNATIONAL JOURNAL OF ADHESION AND ADHESIVES LA English DT Article DE aluminum; mercaptoesters; coupling agents; epoxy ID THIOGLYCOLATE CHELATING RESIN; COMPLEXES AB Double cantilever beam experiments performed by Joseph et al. showed increases in strain energy release rate and cohesive failure for mercaptoester-treated aluminum substrates as compared to untreated controls. This paper presents evaluation of the mercaptoester-aluminum reactivity as a first step toward assessing the effectiveness of incorporating the mercaptoester functionality into a polymeric coupling agent for an epoxy-aluminum bond system. Grazing-angle infrared spectroscopy and XPS of mercaptoester-treated solid aluminum substrates did not show evidence of a mercaptoester/aluminum reaction. The reaction was also attempted in solution where potential spatial limitations associated with the solid surface were eliminated. IR and NMR showed no evidence of reactivity between the mercaptoester and aluminum ions in solution. Theoretically, the Hard-Soft Acid-Base Theory, in conjunction with the Mison equation, does not support a mercaptoester-aluminum reaction. Thus incorporating a mercaptoester into a polymeric coupling agent for an epoxy-aluminum bond system would not result in chemical bonding. In addition, no significant reaction between thiols and aluminum in general, in the presence of water and moist air, is expected. O 2000 Elsevier Science Ltd. All rights reserved. C1 Univ Connecticut, Inst Sci Mat, Dept Chem Engn, Storrs, CT 06269 USA. Univ Connecticut, Inst Sci Mat, Polymer Program, Storrs, CT 06269 USA. Sandia Natl Labs, Organ Mat Dept, Albuquerque, NM 87185 USA. Univ Connecticut, Dept Chem Engn, Storrs, CT 06269 USA. RP Bell, JP (reprint author), Univ Connecticut, Inst Sci Mat, Dept Chem Engn, Storrs, CT 06269 USA. NR 26 TC 2 Z9 2 U1 1 U2 7 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0143-7496 J9 INT J ADHES ADHES JI Int. J. Adhes. Adhes. PD DEC PY 2000 VL 20 IS 6 BP 429 EP 436 DI 10.1016/S0143-7496(00)00010-5 PG 8 WC Engineering, Chemical; Materials Science, Multidisciplinary SC Engineering; Materials Science GA 375FA UT WOS:000165387800001 ER PT J AU Jensen, MK Love, BJ Grant, JW Cotton, J Keiser, JR Wilson, DF AF Jensen, MK Love, BJ Grant, JW Cotton, J Keiser, JR Wilson, DF TI Comparison study of dicyandiamide-cured epoxy bonded steel joints and polyamidoamine-cured epoxy bonded steel joints SO INTERNATIONAL JOURNAL OF ADHESION AND ADHESIVES LA English DT Article DE steel; underwater repair; epoxy; three-point flexure; interfacial sheer strength; dicyandiamide; polyamidoamine ID CORROSION AB There are instances where efficiency and safety may be compromised as a result of deteriorating fluid transport systems. Thus, it is worth evaluating other methods that can repair the damage for a temporary period without shutting down the operation. The objective was to evaluate the durability of an epoxy-bonded steel in aqueous environments that would represent such a repair. EPON(R) 828 was chosen as the epoxy resin, and dicyandiamide and polyamidoamine were two types of curing agents evaluated in this study. The epoxy-bonded steel joints were exposed in either distilled water or 3.4% NaCl solution for various times. The mechanical strength of the bonded joints was evaluated using a three-point flexure test. The interfacial shear strength of unaged samples ranged from 0.93 to 0.32 MPa. It was found that the interfacial shear strength decreased with aging time for both epoxy-bonded systems. Scanning electron microscopy (SEM), optical microscopy, and X-ray photoelectron spectroscopy (XPS) were used to determine the locus of failure of the bonded joints. It was concluded that failure occurred cohesively within the oxide layer if oxides were present on the substrate surface prior to the bonding procedure. (C) 2000 Elsevier Science Ltd. All rights reserved. C1 Virginia Polytech Inst & State Univ, Dept Mat Sci & Engn, Blacksburg, VA 24061 USA. Virginia Polytech Inst & State Univ, Dept Engn Sci & Mech, Blacksburg, VA 24061 USA. Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Love, BJ (reprint author), Virginia Polytech Inst & State Univ, Dept Mat Sci & Engn, Blacksburg, VA 24061 USA. RI Love, Brian/A-8702-2008; Cotton, John/H-6302-2011 OI Love, Brian/0000-0002-7319-5481; Cotton, John/0000-0003-4029-2565 NR 14 TC 3 Z9 3 U1 1 U2 5 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0143-7496 J9 INT J ADHES ADHES JI Int. J. Adhes. Adhes. PD DEC PY 2000 VL 20 IS 6 BP 437 EP 444 DI 10.1016/S0143-7496(00)00014-2 PG 8 WC Engineering, Chemical; Materials Science, Multidisciplinary SC Engineering; Materials Science GA 375FA UT WOS:000165387800002 ER PT J AU Fischer, SL Dryer, FL Curran, HJ AF Fischer, SL Dryer, FL Curran, HJ TI The reaction kinetics of dimethyl ether. I: High-temperature pyrolysis and oxidation in flow reactors SO INTERNATIONAL JOURNAL OF CHEMICAL KINETICS LA English DT Review ID TERT-BUTYL ETHER; SHOCK-TUBE; GAS-PHASE; FLASH-PHOTOLYSIS; METHYL RADICALS; ATOMIC-HYDROGEN; RATE CONSTANTS; RECOMBINATION REACTIONS; COMBUSTION CHEMISTRY; RATE COEFFICIENTS AB Dimethyl ether reaction kinetics at high temperature were studied in two different flow reactors under highly dilute conditions. Pyrolysis of dimethyl ether was studied in a variable-pressure now reactor at 2.5 atm and 1118 K. Studies were also conducted in an atmospheric pressure flow reactor at about 1085 K. These experiments included trace-oxygen-assisted pyrolysis, as well as full oxidation experiments, with the equivalence ratio (phi) varying From 0.32 less than or equal to phi less than or equal to 3.4. On-line, continuous, extractive sampling in conjunction with Fourier Transform infra-Red, Non-Dispersive Infra-Red (for CO and CO2) and electrochemical (for O-2) analyses were performed to quantify species at specific locations along the axis of the turbulent flow reactors. Species concentrations were correlated against residence time in the reactor and species evolution profiles were compared to the predictions of a previously published detailed kinetic mechanism. Some changes were made to the model in order to improve agreement with the present experimental data. However, the revised model continues to reproduce previously reported high-temperature jet-stirred reactor and shock tube results. (C) 2000 John Wiley & Sons, Inc. C1 Princeton Univ, Dept Mech & Aerosp Engn, Princeton, NJ 08544 USA. Univ Calif Lawrence Livermore Natl Lab, Chem & Mat Sci Directorate, Livermore, CA 94551 USA. RP Dryer, FL (reprint author), Princeton Univ, Dept Mech & Aerosp Engn, Princeton, NJ 08544 USA. OI Curran, Henry/0000-0002-5124-8562 NR 132 TC 189 Z9 198 U1 4 U2 48 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 DEC PY 2000 VL 32 IS 12 BP 713 EP 740 DI 10.1002/1097-4601(2000)32:12<713::AID-KIN1>3.0.CO;2-9 PG 28 WC Chemistry, Physical SC Chemistry GA 365LV UT WOS:000089953500001 ER PT J AU Curran, HJ Fischer, SL Dryer, FL AF Curran, HJ Fischer, SL Dryer, FL TI The reaction kinetics of dimethyl ether. II: Low-temperature oxidation in flow reactors SO INTERNATIONAL JOURNAL OF CHEMICAL KINETICS LA English DT Article ID CH3OCH2O2 RADICALS; RATE CONSTANTS; SELF-REACTION; GAS-PHASE; COMBUSTION; PRESSURE; DEPENDENCE; CHEMISTRY; MECHANISM; RANGE AB Dimethyl ether oxidation has been studied in a variable-pressure flow reactor over an initial reactor temperature range of 550-850 K, in the pressure range 12-18 atm, at equivalence ratios of 0.7 less than or equal to phi less than or equal to 4.2, with nitrogen diluent of approximately 98.5%. On-line extraction sampling in conjunction with FTIR, NDIR (For CO and CO2), and electrochemical (For O-2) analyses were performed to quantify species at specific locations along the axis of the turbulent now reactor Product species concentrations were correlated against residence time (at constant inlet temperature) and against temperature (at fixed mean residence time) in the reactor. Formic acid was observed as a major intermediate of dimethyl ether oxidation at low temperatures. The experimental species-evolution profiles were compared to the predictions of a previously published detailed kinetic mechanism [1]. This mechanism did not predict the Formation of formic acid. In the current study we have included chemistry leading to formic acid formation (and oxidation). This new chemistry is discussed and is able to reproduce the experimental observations with good accuracy. In addition, this model is able to reproduce low-temperature kinetic data obtained in a jet-stirred reactor [2] and the shock-tube results of Pfahl et al. [3] (C) 2000 John Wiley & Sons, Inc. C1 Princeton Univ, Dept Mech & Aerosp Engn, Princeton, NJ 08544 USA. Univ Calif Lawrence Livermore Natl Lab, Chem & Mat Sci Directorate, Livermore, CA 94551 USA. RP Dryer, FL (reprint author), Princeton Univ, Dept Mech & Aerosp Engn, Princeton, NJ 08544 USA. OI Curran, Henry/0000-0002-5124-8562 NR 43 TC 190 Z9 206 U1 6 U2 50 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 DEC PY 2000 VL 32 IS 12 BP 741 EP 759 DI 10.1002/1097-4601(2000)32:12<741::AID-KIN2>3.0.CO;2-9 PG 19 WC Chemistry, Physical SC Chemistry GA 365LV UT WOS:000089953500002 ER PT J AU Hoisie, A Lubeck, O Wasserman, H AF Hoisie, A Lubeck, O Wasserman, H TI Performance and scalability analysis of teraflop-scale parallel architectures using multidimensional wavefront applications SO INTERNATIONAL JOURNAL OF HIGH PERFORMANCE COMPUTING APPLICATIONS LA English DT Article AB The authors develop a model for the parallel performance of algorithms that consist of concurrent, two-dimensional wavefronts implemented in a message-passing environment. The model, based on a LogGP machine parameterization, combines the separate contributions of computation and communication wavefronts. The authors validate the model on three important supercomputer systems, on up to 500 processors. They use data from a deterministic particle transport application taken from the ASCI workload, although the model is general to any wavefront algorithm implemented on a 2-D processor domain. They also use the validated model to make estimates of performance and scalability of wavefront algorithms on 100 TFLOPS computer systems expected to be in existence within the next decade as part of the ASCI program and elsewhere. In this context, the authors analyze two problem sizes. Their model shows that on the largest such problem (1 billion cells), interprocessor communication performance is not the bottleneck. Single-node efficiency is the dominant factor. C1 Los Alamos Natl Lab, Sci Comp Grp, Los Alamos, NM 87545 USA. RP Los Alamos Natl Lab, Sci Comp Grp, CIC-3,MS B256, Los Alamos, NM 87545 USA. EM hoisie@lanl.gov NR 17 TC 47 Z9 48 U1 0 U2 3 PU SAGE PUBLICATIONS LTD PI LONDON PA 1 OLIVERS YARD, 55 CITY ROAD, LONDON EC1Y 1SP, ENGLAND SN 1094-3420 EI 1741-2846 J9 INT J HIGH PERFORM C JI Int. J. High Perform. Comput. Appl. PD WIN PY 2000 VL 14 IS 4 BP 330 EP 346 DI 10.1177/109434200001400405 PG 17 WC Computer Science, Hardware & Architecture; Computer Science, Interdisciplinary Applications; Computer Science, Theory & Methods SC Computer Science GA 416PV UT WOS:000167790100005 ER PT J AU Keahey, K Beckman, P Ahrens, J AF Keahey, K Beckman, P Ahrens, J TI Ligature: Component architecture for high performance applications SO INTERNATIONAL JOURNAL OF HIGH PERFORMANCE COMPUTING APPLICATIONS LA English DT Article AB The increasing feasibility of developing applications spanning nationwide supercomputing resources makes possible the creation of simulations composed of multiple interdisciplinary components and capable of modeling natural and social phenomena of national importance with unprecedented speed and accuracy. However, the potential offered by hardware technology often fails to be fury realized due to the lack of software environments supporting such efforts. Furthermore, the complexity of combining within one application components with different performance characteristics often prevents such applications from achieving required performance levels. The Ligature project at Los Alamos National Laboratory addresses the issue of designing a software infrastructure enabling fast and efficient development of multicomponent applications and that of providing performance guidance to the programmer using this infrastructure. Ligature allows the programmer to define component interfaces specifying how heterogeneous, distributed components can interact within a larger system and provides a reusable infrastructure capable of connecting these components. These interfaces, as well as information about component performance, are accessible through a database. Within this framework, we are trying to understand how information about the performance of individual components and information about performance of the framework can be combined to develop a performance-aware multicomponent application. C1 Los Alamos Natl Lab, CIC ACL, Adv Comp Lab, Los Alamos, NM 87545 USA. RP Los Alamos Natl Lab, CIC ACL, Adv Comp Lab, MS B287, Los Alamos, NM 87545 USA. EM kate@acl.lanl.gov NR 13 TC 12 Z9 12 U1 0 U2 0 PU SAGE PUBLICATIONS LTD PI LONDON PA 1 OLIVERS YARD, 55 CITY ROAD, LONDON EC1Y 1SP, ENGLAND SN 1094-3420 EI 1741-2846 J9 INT J HIGH PERFORM C JI Int. J. High Perform. Comput. Appl. PD WIN PY 2000 VL 14 IS 4 BP 347 EP 356 DI 10.1177/109434200001400406 PG 10 WC Computer Science, Hardware & Architecture; Computer Science, Interdisciplinary Applications; Computer Science, Theory & Methods SC Computer Science GA 416PV UT WOS:000167790100006 ER PT J AU Vetter, JS Reed, DA AF Vetter, JS Reed, DA TI Real-time performance monitoring, adaptive control, and interactive steering of computational grids SO INTERNATIONAL JOURNAL OF HIGH PERFORMANCE COMPUTING APPLICATIONS LA English DT Article AB To support creation of nimble applications for computational grids, the authors believe one must eliminate the barrier that separates program creation from execution and post-mortem optimization. This paper outlines an approach to dynamic performance adaptation and distributed optimization in the grid environment based on a suite of performance instrumentation, analysis, and presentation tools that includes distributed performance sensors and resource policy actuators, fuzzy logic rule bases for adaptive control, and immersive visualization systems for real-time visualization and direct manipulation of software behavior. C1 Univ Illinois, Dept Comp Sci, Urbana, IL 61801 USA. Lawrence Livermore Natl Lab, Ctr Appl Sci Comp, Livermore, CA USA. RP Univ Illinois, Dept Comp Sci, 1304 W Springfield Ave, Urbana, IL 61801 USA. EM reed@cs.uiuc.edu NR 11 TC 38 Z9 38 U1 0 U2 1 PU SAGE PUBLICATIONS LTD PI LONDON PA 1 OLIVERS YARD, 55 CITY ROAD, LONDON EC1Y 1SP, ENGLAND SN 1094-3420 EI 1741-2846 J9 INT J HIGH PERFORM C JI Int. J. High Perform. Comput. Appl. PD WIN PY 2000 VL 14 IS 4 BP 357 EP 366 DI 10.1177/109434200001400407 PG 10 WC Computer Science, Hardware & Architecture; Computer Science, Interdisciplinary Applications; Computer Science, Theory & Methods SC Computer Science GA 416PV UT WOS:000167790100007 ER PT J AU Deng, W Morrison, DP Gale, KL Lucas, JN AF Deng, W Morrison, DP Gale, KL Lucas, JN TI A comparative study on potential cytogenetic fingerprints for radiation LET in human lymphocytes SO INTERNATIONAL JOURNAL OF RADIATION BIOLOGY LA English DT Article ID IN-SITU HYBRIDIZATION; DENSELY IONIZING-RADIATION; TRUE INCOMPLETE EXCHANGES; DOUBLE-STRAND BREAKS; CHROMOSOMAL FINGERPRINT; HUMAN FIBROBLASTS; TELOMERIC PNA; ABERRATIONS; EXPOSURE; PROBES AB Purpose: To carry out a comparative study on potential cytogenetic fingerprints for radiation LET in human metaphase lymphocytes. Materials and methods: Human lymphocytes were irradiated in vitro with 3.0 Gy Co-60 gamma -rays, 0.9 Gy H-3 beta -rays or 0.2 Gy 2.7 Mev neutrons. Detailed chromosome aberrations were analysed by combined FISH with pan-telomere staining and specific whole-chromosome painting (1, 2 and 4). Total chromosome translocations and insertions were also analysed by multicolour whole-chromosome painting (chromosomes 1, 2 and dr orange, chromosomes 3, 5 and 6 green). Results: Among the six proposed radiation cytogenetic fingerprints, the ratio of total simple translocations to insertions (I-ratio), showed the largest: difference between low-LET Co-60 gamma -ray and high-LET neutron radiation. The ratios of complete exchanges to incomplete rejoinings [S(II)-ratio] and dicentrics to interstitial deletions (H-ratio), showed a similar significant difference between low- and high-LET radiation. The ratios of centric rings to interstitial deletion (G-ratio) showed a trend of LET-related difference, but the difference was not significant in this data set. The ratios of dicentrics to centric rings (F-ratio) and apparent complete exchanges to hidden complete exchanges [S(II)-ratio], showed no difference between low- and high-LET radiation. In the 1426 radiation-induced chromosome aberrations observed after 52 h culture, evidence for sister-chromatid fusion but not telomere addition was found. Conclusion: Pan-telomere staining plus specific whole chromosome painting allows simultaneous and objective detection of complete or incomplete chromosome exchanges and interstitial or terminal deletions in human peripheral lymphocytes. Of the six proposed cytogenetic ratios, the I-ratio is the most effective cytogenetic fingerprint for distinguishing low-LET from high-LET radiation in human metaphase human lymphocytes. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. Sichuan Inst Radiat Hlth & Protect, Chengdu 610041, Sichuan, Peoples R China. AECL, Chalk River Labs, Chalk River, ON K0J 1J0, Canada. RP Lucas, JN (reprint author), Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. NR 34 TC 19 Z9 20 U1 0 U2 2 PU TAYLOR & FRANCIS LTD PI LONDON PA 11 NEW FETTER LANE, LONDON EC4P 4EE, ENGLAND SN 0955-3002 J9 INT J RADIAT BIOL JI Int. J. Radiat. Biol. PD DEC PY 2000 VL 76 IS 12 BP 1589 EP 1598 PG 10 WC Biology; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Life Sciences & Biomedicine - Other Topics; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA 383WF UT WOS:000165906800002 PM 11133040 ER PT J AU Gaffney, ES AF Gaffney, ES TI Transmission of high-amplitude stress pulses through ice- or water-filled joints SO INTERNATIONAL JOURNAL OF ROCK MECHANICS AND MINING SCIENCES LA English DT Article ID WAVE; ROCK; COMPRESSION; FRACTURES; CALCITE C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Gaffney, ES (reprint author), Univ Calif Los Alamos Natl Lab, EES-5 Geoanal,MS F665,POB 1663, Los Alamos, NM 87545 USA. NR 17 TC 0 Z9 0 U1 1 U2 2 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 1365-1609 J9 INT J ROCK MECH MIN JI Int. J. Rock Mech. Min. Sci. PD DEC PY 2000 VL 37 IS 8 BP 1277 EP 1283 DI 10.1016/S1365-1609(00)00043-5 PG 7 WC Engineering, Geological; Mining & Mineral Processing SC Engineering; Mining & Mineral Processing GA 384VP UT WOS:000165967100009 ER PT J AU Kheyfets, A Miller, WA Newton, GA AF Kheyfets, A Miller, WA Newton, GA TI Schild's ladder parallel transport procedure for an arbitrary connection SO INTERNATIONAL JOURNAL OF THEORETICAL PHYSICS LA English DT Article AB We analyze the Schild's ladder parallel transport procedure for on arbitrary connection. We demonstrate that the procedure, while it can be performed for any connection. in fact is only capable of detecting the symmetric part of this connection. In geometries with a symmetric connection it fulfills its goal to express connection and parallel transport of any vector in terms of geodesics of such geometries. C1 N Carolina State Univ, Dept Math, Raleigh, NC 27695 USA. Univ Calif Los Alamos Natl Lab, Div Theoret, Theoret Astrophys Grp T6 MS B288, Los Alamos, NM 87545 USA. N Carolina State Univ, Dept Phys, Raleigh, NC 27695 USA. RP Kheyfets, A (reprint author), N Carolina State Univ, Dept Math, Box 8205, Raleigh, NC 27695 USA. NR 4 TC 3 Z9 3 U1 0 U2 0 PU KLUWER ACADEMIC/PLENUM PUBL PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 0020-7748 J9 INT J THEOR PHYS JI Int. J. Theor. Phys. PD DEC PY 2000 VL 39 IS 12 BP 2891 EP 2898 DI 10.1023/A:1026473418439 PG 8 WC Physics, Multidisciplinary SC Physics GA 391LA UT WOS:000166356400010 ER PT J AU Butler, BD Haeffner, DR Lee, PL Welberry, TR AF Butler, BD Haeffner, DR Lee, PL Welberry, TR TI High-energy X-ray diffuse scattering using Weissenberg flat-cone geometry (vol 33, 1046, 2000) SO JOURNAL OF APPLIED CRYSTALLOGRAPHY LA English DT Correction C1 SRI, CAT, Adv Photon Source, Argonne Natl Lab, Argonne, IL USA. Natl Inst Stand & Technol, Div Phys & Chem Properties, Boulder, CO 80303 USA. Australian Natl Univ, Res Sch Chem, Canberra, ACT 0200, Australia. RP Haeffner, DR (reprint author), SRI, CAT, Adv Photon Source, Argonne Natl Lab, Argonne, IL USA. RI Welberry, Thomas/H-7847-2014 OI Welberry, Thomas/0000-0002-6906-9191 NR 2 TC 0 Z9 0 U1 0 U2 1 PU MUNKSGAARD INT PUBL LTD PI COPENHAGEN PA 35 NORRE SOGADE, PO BOX 2148, DK-1016 COPENHAGEN, DENMARK SN 0021-8898 J9 J APPL CRYSTALLOGR JI J. Appl. Crystallogr. PD DEC 1 PY 2000 VL 33 BP 1449 EP 1048 DI 10.1107/S0021889800013911 PN 6 PG 3 WC Chemistry, Multidisciplinary; Crystallography SC Chemistry; Crystallography GA 376ZV UT WOS:000165488200024 ER PT J AU Scherzinger, W Triantafyllidis, N AF Scherzinger, W Triantafyllidis, N TI Asymptotic stability analysis for sheet metal forming - Part I: Theory SO JOURNAL OF APPLIED MECHANICS-TRANSACTIONS OF THE ASME LA English DT Article AB In his paper is presented a general methodology for predicting puckering instabilities in sheet metal forming applications. A novel approach is introduced which does not use shell theory approximations. The starting point is Hill's stability functional for a three-dimensional rate independent stressed solid which is modified for contact. By using a multiple scale asymptotic technique with respect to the small dimensionless thickness parameter epsilon, one can derive the two-dimensional version of the stability functional which is accurate up to O(epsilon (4)), thus taking into account bending effects. Loss of positive definiteness of this functional indicates possibility of a puckering instability in a sheet metal forming problem with a known stress and deformation state. An advantage of the proposed method is that the puckering investigation is' independent of the algorithm used for calculating the deformed state of the sheet. [S0021-8936(00)00804-7]. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. Univ Michigan, Dept Aerosp Engn, Ann Arbor, MI 48109 USA. RP Scherzinger, W (reprint author), Sandia Natl Labs, POB 5800,MS 0847, Albuquerque, NM 87185 USA. NR 9 TC 0 Z9 0 U1 1 U2 3 PU ASME-AMER SOC MECHANICAL ENG PI NEW YORK PA THREE PARK AVE, NEW YORK, NY 10016-5990 USA SN 0021-8936 J9 J APPL MECH-T ASME JI J. Appl. Mech.-Trans. ASME PD DEC PY 2000 VL 67 IS 4 BP 685 EP 690 DI 10.1115/1.1325012 PG 6 WC Mechanics SC Mechanics GA 407UV UT WOS:000167289900007 ER PT J AU Scherzinger, W Chu, E Triantafyllidis, N AF Scherzinger, W Chu, E Triantafyllidis, N TI Asymptotic stability analysis for sheet metal forming - Part II: Application SO JOURNAL OF APPLIED MECHANICS-TRANSACTIONS OF THE ASME LA English DT Article AB The general asymptotic method proposed in Part I is applied to the investigation of the puckering instability in the hemispherical cup test. Both a membrane and a shell stress state for the principal axisymmetric solution have been considered. Due to the possibility of strong deviations from proportional loading in some cases, a corner theory of plasticity is also employed, in addition to the standard J(2) deformation theory which is often used in plastic buckling calculations. Results are compared to a previous experimental investigation for brass specimens. [S0021-8936(00)00804-1]. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. ALCOA Inc, Alcoa Tech Ctr, Alcoa Center, PA 15069 USA. Univ Michigan, Dept Aerosp Engn, Ann Arbor, MI 48109 USA. RP Scherzinger, W (reprint author), Sandia Natl Labs, POB 5800,MS 0847, Albuquerque, NM 87185 USA. NR 7 TC 0 Z9 0 U1 0 U2 0 PU ASME-AMER SOC MECHANICAL ENG PI NEW YORK PA THREE PARK AVE, NEW YORK, NY 10016-5990 USA SN 0021-8936 J9 J APPL MECH-T ASME JI J. Appl. Mech.-Trans. ASME PD DEC PY 2000 VL 67 IS 4 BP 691 EP 696 DI 10.1115/1.1325013 PG 6 WC Mechanics SC Mechanics GA 407UV UT WOS:000167289900008 ER PT J AU Butcher, EA Segalman, DJ AF Butcher, EA Segalman, DJ TI Characterizing damping and restitution in compliant impacts via modified K-V and higher-order linear viscoelastic models SO JOURNAL OF APPLIED MECHANICS-TRANSACTIONS OF THE ASME LA English DT Article ID DYNAMICS C1 Univ Alaska, Dept Mech Engn, Fairbanks, AK 99775 USA. Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Butcher, EA (reprint author), Univ Alaska, Dept Mech Engn, Fairbanks, AK 99775 USA. NR 11 TC 19 Z9 19 U1 0 U2 1 PU ASME-AMER SOC MECHANICAL ENG PI NEW YORK PA THREE PARK AVE, NEW YORK, NY 10016-5990 USA SN 0021-8936 J9 J APPL MECH-T ASME JI J. Appl. Mech.-Trans. ASME PD DEC PY 2000 VL 67 IS 4 BP 831 EP 834 DI 10.1115/1.1308578 PG 4 WC Mechanics SC Mechanics GA 407UV UT WOS:000167289900031 ER PT J AU Frew, DJ Forrestal, MJ Hanchak, SJ AF Frew, DJ Forrestal, MJ Hanchak, SJ TI Penetration experiments with limestone targets and ogive-nose steel projectiles SO JOURNAL OF APPLIED MECHANICS-TRANSACTIONS OF THE ASME LA English DT Article ID CONCRETE TARGETS; ALUMINUM TARGETS; RODS AB We conducted three sets of depth-of-penetration experiments with limestone targets and 3.0 caliber-radius-head (CRH), ogive-nose steel rod projectiles. The ogive-nose rad projectiles with length-to-diameter ratios of ten were machined from 4340 R-C 45 and Aer Met 100 R-C 53 steel, round stock and had diameters and masses of 7.1 mm, 0.020 kg; 12.7 mm, 0.117 kg; and 25.4 mm, 0.931 kg. C1 USA, Waterways Expt Stn, Vicksburg, MS 39180 USA. Sandia Natl Labs, Albuquerque, NM 87185 USA. Univ Dayton, Res Inst, Dayton, OH 45469 USA. RP Frew, DJ (reprint author), USA, Waterways Expt Stn, Vicksburg, MS 39180 USA. NR 24 TC 37 Z9 48 U1 2 U2 13 PU ASME PI NEW YORK PA TWO PARK AVE, NEW YORK, NY 10016-5990 USA SN 0021-8936 EI 1528-9036 J9 J APPL MECH-T ASME JI J. Appl. Mech.-Trans. ASME PD DEC PY 2000 VL 67 IS 4 BP 841 EP 845 DI 10.1115/1.1331283 PG 5 WC Mechanics SC Mechanics GA 407UV UT WOS:000167289900035 ER PT J AU Hixson, RS Shaw, MS Fritz, JN Vorthman, JE Anderson, WW AF Hixson, RS Shaw, MS Fritz, JN Vorthman, JE Anderson, WW TI Release isentropes of overdriven plastic-bonded explosive PBX-9501 SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID INTERFEROMETER AB Continuous release isentropes for the plastic-bonded explosive PBX-9501 are obtained from velocity interferometer system for any reflector measurements at a high-explosive/LiF interface. Forward calculations from a tabular representation of the isentropes to the measured u(t) data at the interface are iterated to yield isentropes that give agreement with the data. Curves for the isentropes and for the isentropic gamma, gammas=-(partial derivative lnP/partial derivative lnV)(s) are presented. Because isentropes from different overdriven states differ, a crude estimate of the Gruneisen parameter is obtained. An overall representation of the data is achieved with this Gruneisen parameter and a single isentrope through the Chapman-Jouguet state. (C) 2000 American Institute of Physics. [S0021-8979(00)04524-2]. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Fritz, JN (reprint author), Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. EM fritzjn@lanl.gov NR 14 TC 7 Z9 7 U1 1 U2 9 PU AMER INST PHYSICS PI MELVILLE PA 1305 WALT WHITMAN RD, STE 300, MELVILLE, NY 11747-4501 USA SN 0021-8979 EI 1089-7550 J9 J APPL PHYS JI J. Appl. Phys. PD DEC 1 PY 2000 VL 88 IS 11 BP 6287 EP 6293 DI 10.1063/1.1323513 PG 7 WC Physics, Applied SC Physics GA 377TW UT WOS:000165543200020 ER PT J AU Burakovsky, L Preston, DL Silbar, RR AF Burakovsky, L Preston, DL Silbar, RR TI Analysis of dislocation mechanism for melting of elements: Pressure dependence SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID UNIVERSAL EQUATION; BULK MODULUS; PHASE-TRANSITIONS; CURVE; STATE; IRON; TEMPERATURE; SOLIDS; VELOCITIES; THORIUM AB In the framework of melting as a dislocation-mediated phase transition we derive an equation for the pressure dependence of the melting temperatures of the elements valid up to pressures of order their ambient bulk moduli. Melting curves are calculated for Al, Mg, Ni, Pb, the iron group (Fe, Ru, Os), the chromium group (Cr, Mo, W), the copper group (Cu, Ag, Au), noble gases (Ne, Ar, Kr, Xe, Rn), and six actinides (Am, Cm, Np, Pa, Th, U). These calculated melting curves are in good agreement with existing data. We also discuss the apparent equivalence of our melting relation and the Lindemann criterion, and the lack of the rigorous proof of their equivalence. We show that the would-be mathematical equivalence of both formulas must manifest itself in a new relation between the Gruneisen constant, bulk and shear moduli, and the pressure derivative of the shear modulus. (C) 2000 American Institute of Physics. [S0021-8979(00)03624-0]. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. WhistleSoft Inc, Los Alamos, NM 87544 USA. RP Burakovsky, L (reprint author), Univ Calif Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. NR 62 TC 42 Z9 44 U1 1 U2 6 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD DEC 1 PY 2000 VL 88 IS 11 BP 6294 EP 6301 DI 10.1063/1.1323535 PG 8 WC Physics, Applied SC Physics GA 377TW UT WOS:000165543200021 ER PT J AU Barsoum, MW El-Raghy, T Porter, WD Wang, H Ho, JC Chakraborty, S AF Barsoum, MW El-Raghy, T Porter, WD Wang, H Ho, JC Chakraborty, S TI Thermal properties of Nb2SnC SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID TI3SIC2 AB In this article we report on the thermal properties of the ternary carbide Nb2SnC. Its heat capacity, c(p), is 75 J/mol K at ambient temperatures and increases to approximate to 115 J/mol K at 1300 K. Analysis of c(p) measurements in the 4-15 K temperature range yields a Debye temperature of 324 K and a density of states at the Fermi level of 2.66 (eV unit cell)(-1). At room temperature, the thermal conductivity is 17 W/m K and it increases to approximate to 31 W/m K at 1500 K. At temperatures greater than 600 K, roughly 85% of the heat is transported by electronic defects (i.e., electrons and/or holes). The thermal properties-of Nb2SnC are quite comparable to those of near-stoichiometric NbCx. (C) 2000 American Institute of Physics. [S0021-8979(00)02822-X]. C1 Drexel Univ, Dept Mat Engn, Philadelphia, PA 19104 USA. Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. Wichita State Univ, Dept Phys, Wichita, KS 67260 USA. RP Barsoum, MW (reprint author), Drexel Univ, Dept Mat Engn, Philadelphia, PA 19104 USA. RI Wang, Hsin/A-1942-2013 OI Wang, Hsin/0000-0003-2426-9867 NR 22 TC 26 Z9 27 U1 0 U2 4 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD DEC 1 PY 2000 VL 88 IS 11 BP 6313 EP 6316 DI 10.1063/1.1315326 PG 4 WC Physics, Applied SC Physics GA 377TW UT WOS:000165543200023 ER PT J AU Bullen, AJ O'Hara, KE Cahill, DG Monteiro, O von Keudell, A AF Bullen, AJ O'Hara, KE Cahill, DG Monteiro, O von Keudell, A TI Thermal conductivity of amorphous carbon thin films SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID DIAMOND-LIKE CARBON; DEPOSITION; TRANSPORT; CRYSTALS AB Thermal conductivities Lambda of amorphous carbon thin films are measured in the temperatures range 80-400 K using the 3 omega method. Sample films range from soft a-C:H prepared by remote-plasma deposition (Lambda = 0.20 W m(-1) K-1 at room temperature) to amorphous diamond with a large fraction of sp(3) bonded carbon deposited from a filtered-are source (Lambda = 2.2 W m(-1) K-1). Effective-medium theory provides a phenomenological description of the variation of conductivity with mass density. The thermal conductivities are in good agreement with the minimum thermal conductivity calculated from the measured atomic density and longitudinal speed of sound. (C) 2000 American Institute of Physics. [S0021-8979(00)07221-2]. C1 Univ Illinois, Dept Mat Sci & Engn, Coordinated Sci Lab, Urbana, IL 61801 USA. Univ Illinois, Mat Res Lab, Urbana, IL 61801 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. Max Planck Inst Plasma Phys, D-85740 Garching, Germany. RP Bullen, AJ (reprint author), Univ Illinois, Dept Mat Sci & Engn, Coordinated Sci Lab, 1304 W Green St, Urbana, IL 61801 USA. RI Cahill, David/B-3495-2014 NR 24 TC 84 Z9 84 U1 4 U2 37 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD DEC 1 PY 2000 VL 88 IS 11 BP 6317 EP 6320 DI 10.1063/1.1314301 PG 4 WC Physics, Applied SC Physics GA 377TW UT WOS:000165543200024 ER PT J AU Lim, SH Swider, W Washburn, J Liliental-Weber, Z AF Lim, SH Swider, W Washburn, J Liliental-Weber, Z TI Structural analysis of interfacial layers in Ti/Ta/Al ohmic contacts to n-AlGaN SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID GAN; TI/AL; MICROSTRUCTURE AB Detailed structure of the interfacial layers of Ti/Ta/Al ohmic contacts to n-type AlGaN/GaN/ sapphire are investigated by means of transmission electron microscopy. High-resolution electron microscopy (HREM), optical diffractograms, and computer simulations confirmed that TiN (similar to 10.0 nm) and Ti3AlN (similar to1.4 nm) interfacial layers form at the interface between the Ti layer and the Al0.35Ga0.65N substrate by a solid state reaction during annealing for 3 min in N-2 at 950 degreesC. The orientation relationship between Ti3AlN and Al0.35Ga0.65N was found to be: [011](Ti3AlN)parallel to [2 (1) over bar(1) over bar0](Al0.35Ga0.65N) and (1 (1) over bar1)(Ti3AlN)parallel to (0 (0) over bar 01)(Al0.35Ga0.65N). The cubic Ti3AlN interfacial layer, has a lattice parameter of 0.411+/-0.003 nm with the space group Pm3m matching that of Al0.35Ga0.65N A model of the atomic configurations of the Ti3AlN/Al0.35Ga0.65N interface is proposed. This model is supported by a good match between the simulated and the experimental HREM image of the Ti3AlN/Al0.35Ga0.65N interface. The formation of TiN and Ti3AlN interfacial layers appears to be responsible for the onset of the ohmic contact behavior in Ti/Ta/Al contacts. (C) 2000 American Institute of Physics. [S0021-8979(00)04924-0]. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. RP Lim, SH (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. RI Liliental-Weber, Zuzanna/H-8006-2012 NR 13 TC 11 Z9 11 U1 0 U2 2 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD DEC 1 PY 2000 VL 88 IS 11 BP 6364 EP 6368 DI 10.1063/1.1323517 PG 5 WC Physics, Applied SC Physics GA 377TW UT WOS:000165543200031 ER PT J AU Vijayalakshmi, S Grebel, H Yaglioglu, G Pino, R Dorsinville, R White, CW AF Vijayalakshmi, S Grebel, H Yaglioglu, G Pino, R Dorsinville, R White, CW TI Nonlinear optical response of Si nanostructures in a silica matrix SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID NANOCRYSTALS AB We provide a systematic study on the nonlinear optical properties of silicon nanocrystals within a fused silica matrix. Nonlinear measurements at various wavelengths exhibited the role of three bands in the visible spectrum. Measurements at various laser pulse durations showed several time constants, which exhibited the role of quantum confined and surface states. (C) 2000 American Institute of Physics. [S0021-8479(00)04324-3]. C1 New Jersey Inst Technol, Dept Elect & Comp Engn, Newark, NJ 07102 USA. CUNY City Coll, Dept Elect Engn, New York, NY 10031 USA. CUNY, Grad Ctr, New York, NY 10031 USA. Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Vijayalakshmi, S (reprint author), New Jersey Inst Technol, Dept Elect & Comp Engn, Newark, NJ 07102 USA. NR 9 TC 36 Z9 37 U1 0 U2 2 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD DEC 1 PY 2000 VL 88 IS 11 BP 6418 EP 6422 DI 10.1063/1.1323511 PG 5 WC Physics, Applied SC Physics GA 377TW UT WOS:000165543200040 ER PT J AU Imaizumi, M Yamaguchi, K Okitsu, K Yamaguchi, M Hara, T Ito, T Konomi, I Jones, KM Al-Jassim, MM AF Imaizumi, M Yamaguchi, K Okitsu, K Yamaguchi, M Hara, T Ito, T Konomi, I Jones, KM Al-Jassim, MM TI Effects of hydrogen on the growth of nanocrystalline silicon films by electron-beam excited plasma chemical vapor deposition SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID AMORPHOUS-SILICON; MICROCRYSTALLINE SILICON; SURFACE-REACTION; CROSS-SECTIONS; RADICALS; DENSITY AB It has been shown that nanocrystalline silicon films can be grown from silane gas without hydrogen dilution by electron-beam excited plasma chemical vapor deposition (EBEP-CVD). A high density of atomic hydrogen, which is derived from the dissociation of silane molecule, is confirmed in the plasma by optical emission spectroscopy. This fact is thought tb be a reason for the growth of nanocrystalline silicon films without the introduction of hydrogen gas. Transmission electron spectroscopy reveals that crystallites are not distributed uniformly, but rather form the mosaic-like clusters in an amorphous silicon matrix in the film. Hydrogen gas is introduced into the EBEP-CVD silicon film growth so as to study the effects of the hydrogen gas. The growth rate increases proportionally to the hydrogen flow rate, and it is about 2.5 times greater than when no hydrogen gas is introduced. Also, a decrease in both the hydrogen content and the density of dangling bonds in the film is confirmed. These results imply that the generation of dangling bonds is suppressed by the introduction of hydrogen. The rate constants of dissociation reaction of silane molecules in the EBEP are estimated, and the change in density of radicals in the plasma by introducing hydrogen gas is calculated. A growth model is proposed that assumes the sticking coefficient of SiH3 precursor radical increases in proportion to atomic hydrogen flux. Using the calculation results and the model, the effects are explained to be due to an increase in the contribution ratio of SM, radicals to the growth, on account of the increase in the introduced hydrogen gas flow rate. (C) 2000 American Institute of Physics. [S0021-8979(00)10017-9]. C1 Toyota Technol Inst, Tempaku Ku, Nagoya, Aichi 4688511, Japan. Natl Space Dev Agcy Japan, Tsukuba, Ibaraki 3058505, Japan. Toyota Cent Res & Dev Labs Inc, Aichi 4801192, Japan. Natl Renewable Energy Lab, Golden, CO 80401 USA. RP Toyota Technol Inst, Tempaku Ku, 2-12-1 Hisakata, Nagoya, Aichi 4688511, Japan. EM imaizumi.mitsuru@nasda.go.jp; masafumi@toyota-ti.ac.jp NR 29 TC 7 Z9 7 U1 0 U2 3 PU AMER INST PHYSICS PI MELVILLE PA 1305 WALT WHITMAN RD, STE 300, MELVILLE, NY 11747-4501 USA SN 0021-8979 EI 1089-7550 J9 J APPL PHYS JI J. Appl. Phys. PD DEC 1 PY 2000 VL 88 IS 11 BP 6848 EP 6855 DI 10.1063/1.1287754 PG 8 WC Physics, Applied SC Physics GA 377TW UT WOS:000165543200107 ER PT J AU Muck, M Clarke, J AF Muck, M Clarke, J TI The superconducting quantum interference device microstrip amplifier: Computer models SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID MULTITURN INPUT COIL; LOW-NOISE; DC SQUID; RADIOFREQUENCY-AMPLIFIER; RESONANCE AB Computer models are presented for a microstrip amplifier based on a de superconducting quantum interference device (SQUID). In this device, the signal is applied between one end of the spiral input coil and the square washer on which it is deposited. The amplifier exhibits substantial power gain when the signal frequency is such that a half wavelength is approximately equal to the length of the microstrip formed by the coil and the groundplane. The resonant frequency is lowered significantly by the inductance of the square washer transformed into the input coil; this reduction is consistent with predictions of a simple model and with analog simulations. With the washer grounded, the gain of the amplifier peaks at a frequency that is lowered from the unloaded resonant frequency by the damping of the resistance associated with the source. The position and magnitude of the peak are in good agreement with both a lumped circuit model and with a model representing the microstrip as a transmission line. When the counter electrode of the SQUID is grounded and the washer floats, feedback from the output of the SQUID to the input via the capacitance of the microstrip plays a major role and is well described by simulations using the transmission line model. Measurements of the input impedance of the microstrip amplifier show that the return loss can be positive or negative, depending on the sign of the feedback and whether the frequency is above or below the resonant frequency. This behavior is in good accord with simulations. (C) 2000 American Institute of Physics. [S0021-8979 (00)06523-3]. C1 Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. RP Muck, M (reprint author), Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. NR 20 TC 19 Z9 19 U1 0 U2 3 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD DEC 1 PY 2000 VL 88 IS 11 BP 6910 EP 6918 PG 9 WC Physics, Applied SC Physics GA 377TW UT WOS:000165543200116 ER PT J AU Arroyo, CM Schafer, RJ Kurt, EM Broomfield, CA Carmichael, AJ AF Arroyo, CM Schafer, RJ Kurt, EM Broomfield, CA Carmichael, AJ TI Response of normal human keratinocytes to sulfur mustard: Cytokine release SO JOURNAL OF APPLIED TOXICOLOGY LA English DT Article DE vesicant agents; sulfur mustard; ELISA; human keratinocytes; IL-1 beta; IL-6; IL-8; TNF-alpha ID HUMAN EPIDERMAL-KERATINOCYTES; TUMOR-NECROSIS-FACTOR; SKIN; PROLIFERATION; INTERLEUKIN-8; INFLAMMATION; EXPRESSION; EXPOSURE; TOXICITY; CULTURE AB Cytokines play a major role in both acute and chronic inflammatory processes, including those produced by sulfur mustard (2,2 ' -dichlorodiethyl sulfide, HD), This study describes responses of normal human epidermal keratinocytes (NHEK) to HD, defined by interleukin-1 beta (IL-1 beta), IL-6, IL-8 and tumor necrosis factor alpha (TNF-alpha) release. Commercially available enzyme-linked immunosorbent assay (ELISA) kits were used to measure the cytokine release in NHEK during exposure to 100 and 300 muM of HD, Exposure to 100 muM Ho increased the release of cytokines, The amounts of IL-8 and TNF-alpha present in cell suspensions increased up to 59-fold and 4-fold, respectively, above control levels when NHEK were exposed to 300 muM HD Exposure of NHEK to 300 muM HD had a highly variable effect on the release of IL-1 beta, where sometimes the secretion of IL-1 beta increased above baseline level and at other times it decreased in cell suspensions. Supernatants were collected from cell culture flasks 24 h after exposure of 100 and 300 muM HD and significantly increased levels of IL-6 were observed. Interleukin-6 was released in a concentration-dependent manner, 3.6-fold up to 8.4-fold, respectively, in supernatant, These pro-inflammatory mediators IL-1 beta, IL-8, TNF-alpha and IL-6 may play an important role in Ho injury, The present findings suggest that the cytokine changes detected could be used as potential biomarkers of cutaneous vesicant injury. Published in 2000 by John Wiley & Sons, Ltd. C1 USA, Med Res Inst Chem Def, MCMR UV DA, Aberdeen Proving Ground, MD 21010 USA. Oak Ridge Inst Sci & Educ, Res Participat Program, Oak Ridge, TN USA. Armed Forces Radiobiol Res Inst, Appl Cellular Radiobiol Dept, Bethesda, MD 20889 USA. RP Arroyo, CM (reprint author), USA, Med Res Inst Chem Def, MCMR UV DA, 3100 Ricketts Rd, Aberdeen Proving Ground, MD 21010 USA. NR 27 TC 1 Z9 1 U1 0 U2 0 PU JOHN WILEY & SONS LTD PI W SUSSEX PA BAFFINS LANE CHICHESTER, W SUSSEX PO19 1UD, ENGLAND SN 0260-437X J9 J APPL TOXICOL JI J. Appl. Toxicol. PD DEC PY 2000 VL 21 SU 1 BP S63 EP S72 PG 10 WC Toxicology SC Toxicology GA 444DG UT WOS:000169383300012 ER PT J AU Arroyo, CM Schafer, RJ Carmichael, AJ AF Arroyo, CM Schafer, RJ Carmichael, AJ TI Reactivity of chloroethyl sulfides in the presence of a chlorinated prophylactic: A kinetic study by EPR/spin trapping and NMR techniques SO JOURNAL OF APPLIED TOXICOLOGY LA English DT Article DE vesicant agents; sulfur mustard; NMR; EPR; spin trapping; chlorinated glycoluril; C-13-NMR; PBN; kinetic; S-330 ID BUTYL 2-CHLOROETHYL SULFIDE; MONOFUNCTIONAL SULFUR MUSTARD; ELECTRON-SPIN-RESONANCE; SUBCUTANEOUS INJECTION AB This study reports the kinetic reaction of a chlorinated glycoluril, 1,3,4,6-tetrachloro-7, 8-diphenyl-2,5-diimino glycoluril, also known as S-330, with butyl 2-chloroethyl sulfide (half-sulfur mustard, H-MG) and bis-(2-chloroethyl) sulfide (sulfur mustard, HD) using electron paramagnetic resonance (EPR)/spin trapping and nuclear magnetic resonance (NMR) techniques. Both II-MO and HD are highly reactive in water and are capable of alkylating a variety of critical target molecules. It is well known that compounds containing reactive chlorine are useful neutralizers of HD and other vesicating agents. Organic compounds containing a chloroamide group are generally preferred. Currently, the reactive mechanism of this chlorinated glycoluril with these chloroethyl sulfides has not been documented. The kinetic experiments were performed by adding the monofunctional sulfur mustard (H-MG) directly to the spin trap agent alpha -phenyl-N-tert-butylnitrone (PBN, pH 7.1). The intensity of the EPR spectra obtained from the resulting spin adduct (hyperfine coupling constants a(N) = 1.45 mT and a(H)(beta) = 0.225 mT) was sensitive to the rate at which the spin adduct was formed. Different concentrations of the chloroamide were added to the reaction mixtures of PEN and H-MG, The EPR spectra of separate identical reaction mixtures were recorded with the spectrometer set for kinetic experiments. The rate constant determined by EPR was 1.78 +/- 0.14 x 10(7) M(-1)s(-1). It was found that S-330 reacts 55 times faster than PEN. The results obtained for S-330 by EPR indicate that S-330 is an efficient scavenger of H-MG, Furthermore, a C-13-NMR chemical shift of 0.903 +/- 0.002 ppm was observed for the Cl-N-CN-Cl carbon in S-330 after exposure to HD (1 mM), In addition, the decay of C-13-NMR resonance at 91.7 ppm chemical shift was observed in the presence of HD, The C-13-NMR data showed that the formation of the ethylene sulfonium ion usually found in the case of HD was not observed in the presence of S-330. Published in 2000 by John Wiley & Sons, Ltd. C1 USA, Med Res Inst Chem Def, Aberdeen Proving Ground, MD 21010 USA. Oak Ridge Inst Sci & Educ, Res Participat Program, Oak Ridge, TN USA. Armed Forces Radiobiol Res Inst, Appl Cellular Radiobiol Dept, Bethesda, MD 20889 USA. RP Arroyo, CM (reprint author), USA, Med Res Inst Chem Def, Aberdeen Proving Ground, MD 21010 USA. NR 9 TC 0 Z9 0 U1 0 U2 2 PU JOHN WILEY & SONS LTD PI W SUSSEX PA BAFFINS LANE CHICHESTER, W SUSSEX PO19 1UD, ENGLAND SN 0260-437X J9 J APPL TOXICOL JI J. Appl. Toxicol. PD DEC PY 2000 VL 21 SU 1 BP S7 EP S12 PG 6 WC Toxicology SC Toxicology GA 444DG UT WOS:000169383300003 ER PT J AU Keim, P Price, LB Klevytska, AM Smith, KL Schupp, JM Okinaka, R Jackson, PJ Hugh-Jones, ME AF Keim, P Price, LB Klevytska, AM Smith, KL Schupp, JM Okinaka, R Jackson, PJ Hugh-Jones, ME TI Multiple-locus variable-number tandem repeat analysis reveals genetic relationships within Bacillus anthracis (vol 182, pg 2928, 2000) SO JOURNAL OF BACTERIOLOGY LA English DT Correction C1 No Arizona Univ, Dept Biol Sci, Flagstaff, AZ 86011 USA. Louisiana State Univ, Sch Vet Med, Dept Epidemiol & Community Hlth, Baton Rouge, LA 70803 USA. Univ Calif Los Alamos Natl Lab, Environm Mol Biol Grp, Los Alamos, NM 87545 USA. RP Keim, P (reprint author), No Arizona Univ, Dept Biol Sci, Box 5640, Flagstaff, AZ 86011 USA. NR 1 TC 3 Z9 3 U1 0 U2 3 PU AMER SOC MICROBIOLOGY PI WASHINGTON PA 1752 N ST NW, WASHINGTON, DC 20036-2904 USA SN 0021-9193 J9 J BACTERIOL JI J. Bacteriol. PD DEC PY 2000 VL 182 IS 23 BP 6862 EP 6862 DI 10.1128/JB.182.23.6862-6862.2000 PG 1 WC Microbiology SC Microbiology GA 407WK UT WOS:000167293600047 ER PT J AU Harvey, TJ Hooper, JD Myers, SA Stephenson, SA Ashworth, LK Clements, JA AF Harvey, TJ Hooper, JD Myers, SA Stephenson, SA Ashworth, LK Clements, JA TI Tissue-specific expression patterns and fine mapping of the human kallikrein (KLK) locus on proximal 19q13.4 SO JOURNAL OF BIOLOGICAL CHEMISTRY LA English DT Article ID PROSTATE-SPECIFIC ANTIGEN; SERINE-PROTEASE GENE; MOLECULAR-CLONING; SEQUENCE-ANALYSIS; FAMILY; RAT; CDNA; ANDROGEN; BREAST; CANCER AB The tissue or glandular kallikreins (KLK) are members of a highly conserved multigene family encoding serine proteases that are central to many biological processes. The rodent KLK families are large, highly conserved and clustered at one locus. The human KLK gene family is clustered on chromosome 19q13.3-13.4, and until recently consisted of just three members. However, recent studies have identified up to II new members of the KLK family that are less conserved than their rodent counterparts. Using a Southern blot and sequence analysis of 10 BACs and cosmids spanning approximately 400 kilobases (kb) either side of the original KLK 60-kb locus, we demonstrated that these genes also lie adjacent to this. We have also clarified the position of several microsatellite markers in relation to the extended KLK locus. Moreover, from Southern blot analysis of the cosmids and BACs with a degenerate oligonucleotide probe to the histidine-encoding region of serine proteases, we have shown that there are no other serine protease genes approximately 400 kb centromeric and 220 kb telomeric of the extended locus. We performed an extensive analysis of the expression patterns of these genes by poly(A)' RNA dot blot and reverse transcriptase-polymerase chain reaction analysis, and demonstrated a diverse pattern of expression. Of interest are clusters of genes with high prostate (KLK2-4) and pancreatic (KLK6-13) expression suggesting evolutionary conservation of elements conferring tissue specificity. From these findings, it is likely that the human KLK gene family consists of just 14 clustered genes within 300 kb and thus is of a comparable size to the rodent families (13-24 genes within 310 and 480 kb, respectively). In contrast to the rodent families, the newest members of the human KLK family are much less conserved in sequence (23-44% at the protein level) and appear to consist of at least four subfamilies. In addition, like the rat, these genes are expressed at varying levels in a diverse range of tissues although they exhibit quite distinct patterns of expression. C1 Queensland Univ Technol, Sch Life Sci, Ctr Mol Biotechnol, Brisbane, Qld 4001, Australia. Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. RP Clements, JA (reprint author), Queensland Univ Technol, Sch Life Sci, Ctr Mol Biotechnol, GPO Box 2434, Brisbane, Qld 4001, Australia. RI Stephenson, Sally-Anne/I-9801-2012; Hooper, John/C-1481-2016; OI Hooper, John/0000-0003-1054-8486; Harvey, Tracey/0000-0001-5388-0337; Stephenson, Sally-Anne/0000-0003-3227-2476; Clements, Judith/0000-0001-6026-1964 NR 49 TC 123 Z9 128 U1 0 U2 2 PU AMER SOC BIOCHEMISTRY MOLECULAR BIOLOGY INC PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814 USA SN 0021-9258 J9 J BIOL CHEM JI J. Biol. Chem. PD DEC 1 PY 2000 VL 275 IS 48 BP 37397 EP 37406 DI 10.1074/jbc.M004525200 PG 10 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA 379AL UT WOS:000165618700014 PM 10969073 ER PT J AU Bowers, PM Strauss, CEM Baker, D AF Bowers, PM Strauss, CEM Baker, D TI De novo protein structure determination using sparse NMR data SO JOURNAL OF BIOMOLECULAR NMR LA English DT Article DE de novo; limited constraints; NOE; protein structure determination; Rosetta ID DISTANCE RESTRAINTS; PROGRAM; NUMBER AB We describe a method for generating moderate to high-resolution protein structures using limited NMR data combined with the ab initio protein structure prediction method Rosetta. Peptide fragments are selected from proteins of known structure based on sequence similarity and consistency with chemical shift and NOE data. Models are built from these fragments by minimizing an energy function that favors hydrophobic burial, strand pairing, and satisfaction of NOE constraints. Models generated using this procedure with similar to1 NOE constraint per residue are in some cases closer to the corresponding X-ray structures than the published NMR solution structures. The method requires only the sparse constraints available during initial stages of NMR structure determination, and thus holds promise for increasing the speed with which protein solution structures can be determined. C1 Univ Washington, Sch Med, Dept Biochem, Seattle, WA 98195 USA. Univ Calif Los Alamos Natl Lab, Biosci Div, Los Alamos, NM 87545 USA. RP Baker, D (reprint author), Univ Washington, Sch Med, Dept Biochem, Seattle, WA 98195 USA. RI Baker, David/K-8941-2012 OI Baker, David/0000-0001-7896-6217 NR 20 TC 106 Z9 108 U1 1 U2 10 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0925-2738 J9 J BIOMOL NMR JI J. Biomol. NMR PD DEC PY 2000 VL 18 IS 4 BP 311 EP 318 DI 10.1023/A:1026744431105 PG 8 WC Biochemistry & Molecular Biology; Spectroscopy SC Biochemistry & Molecular Biology; Spectroscopy GA 381XN UT WOS:000165789500003 PM 11200525 ER PT J AU Nogales, E AF Nogales, E TI Recent structural insights into transcription preinitiation complexes SO JOURNAL OF CELL SCIENCE LA English DT Article DE transcription initiation; gene regulation; image reconstruction ID RNA-POLYMERASE-II; YEAST TFIIA/TBP/DNA COMPLEX; TATA-BINDING PROTEIN; START SITE SELECTION; CRYSTAL-STRUCTURE; ANGSTROM RESOLUTION; TAF(II)-CONTAINING COMPLEX; 3-DIMENSIONAL STRUCTURE; INITIATION COMPLEX; PROMOTER COMPLEX AB Our understanding of the elaborate mechanism of gene transcription initiation in eukaryotes has been widened by recent structural information on some of the key components of the complex preinitiation transcriptional machinery. The high-resolution structures of both bacterial and eukaryotic polymerases are technical landmarks of great biological significance that have given us the first molecular insight into the mechanism of this large enzyme. While new atomic structures of different domains of general transcription factors, such as the double bromodomain of TAF250, have become available by means of X-ray crystallography and NMR studies, more global pictures of multisubunit transcription complexes, such as TFIID, TFIIH or the yeast mediator, have now been obtained by electron microscopy and image-reconstruction techniques. A combination of methodologies may prove essential for a complete structural description of the initial steps in the expression of eukaryotic genes. C1 Univ Calif Berkeley, Dept Mol & Cell Biol, Howard Hughes Med Inst, Berkeley, CA 94720 USA. Lawrence Berkeley Lab, Div Life Sci, LSA, Berkeley, CA 94720 USA. RP Nogales, E (reprint author), Univ Calif Berkeley, Dept Mol & Cell Biol, Howard Hughes Med Inst, 229 Stanley Hall, Berkeley, CA 94720 USA. NR 53 TC 9 Z9 9 U1 1 U2 1 PU COMPANY OF BIOLOGISTS LTD PI CAMBRIDGE PA BIDDER BUILDING CAMBRIDGE COMMERCIAL PARK COWLEY RD, CAMBRIDGE CB4 4DL, CAMBS, ENGLAND SN 0021-9533 J9 J CELL SCI JI J. Cell Sci. PD DEC PY 2000 VL 113 IS 24 BP 4391 EP 4397 PG 7 WC Cell Biology SC Cell Biology GA 390XT UT WOS:000166325600003 PM 11082032 ER PT J AU Hjeresen, DL Schutt, DL Boese, JM AF Hjeresen, DL Schutt, DL Boese, JM TI Green chemistry and education SO JOURNAL OF CHEMICAL EDUCATION LA English DT Editorial Material C1 Univ Calif Los Alamos Natl Lab, Green Chem Inst, Los Alamos, NM 87545 USA. ACS Off Legislat & Govt Affairs, Washington, DC 20036 USA. ACS, Div Educ & Int Activ, Acad Programs, Washington, DC 20036 USA. RP Hjeresen, DL (reprint author), Univ Calif Los Alamos Natl Lab, Green Chem Inst, POB 1663, Los Alamos, NM 87545 USA. NR 2 TC 61 Z9 61 U1 1 U2 19 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0021-9584 J9 J CHEM EDUC JI J. Chem. Educ. PD DEC PY 2000 VL 77 IS 12 BP 1543 EP + PG 4 WC Chemistry, Multidisciplinary; Education, Scientific Disciplines SC Chemistry; Education & Educational Research GA 373XR UT WOS:000165315800004 ER PT J AU Weston, RE AF Weston, RE TI Climate change and its effect on coral reefs SO JOURNAL OF CHEMICAL EDUCATION LA English DT Article ID CARBON-DIOXIDE C1 Brookhaven Natl Lab, Dept Chem, Upton, NY 11973 USA. RP Weston, RE (reprint author), Brookhaven Natl Lab, Dept Chem, Upton, NY 11973 USA. NR 20 TC 2 Z9 2 U1 1 U2 5 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0021-9584 J9 J CHEM EDUC JI J. Chem. Educ. PD DEC PY 2000 VL 77 IS 12 BP 1574 EP 1577 PG 4 WC Chemistry, Multidisciplinary; Education, Scientific Disciplines SC Chemistry; Education & Educational Research GA 373XR UT WOS:000165315800020 ER PT J AU Guallar, V Batista, VS Miller, WH AF Guallar, V Batista, VS Miller, WH TI Semiclassical molecular dynamics simulations of intramolecular proton transfer in photoexcited 2-(2 '-hydroxyphenyl)-oxazole SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID EXCITED-STATE PROTON; HYDROGEN-ATOM TRANSFER; ELECTRON-TRANSFER REACTIONS; FLUORESCENCE UP-CONVERSION; H-BONDED COMPLEXES; CHEMICAL-REACTIONS; 7-AZAINDOLE DIMER; TAUTOMERISM; MODEL; SOLVENT AB A full-dimensional excited state potential energy surface is constructed, and the proton transfer dynamics associated with the keto-enolic tautomerization reaction in photoexcited 2-(2'-hydroxyphenyl)-oxazole is simulated according to an approximate version of the semiclassical initial value representation method introduced by Miller and co-workers [V. Guallar, V. S. Batista, and W. H. Miller, J. Chem. Phys. 110, 9922 (1999)]. The full-dimensional potential energy surface is developed according to an nb initio reaction surface model obtained at the CIS Level of quantum chemistry. Proton transfer is found to be substantially affected by isotopic substitution, and significantly coupled to the internal oxazole-hydroxyphenyl in-the-plane bending mode. The nascent tautomer is found to be stabilized primarily through vibrational energy redistribution into all of the remaining in-the-plane vibrational modes. The accuracy of the methodology is verified by reducing the dimensionality of the system and comparing our semiclassical results with full quantum mechanical calculations. (C) 2000 American lnstitute of Physics. [S0021-9606(00)01845-6]. C1 Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Chem Sci, Berkeley, CA 94720 USA. RP Guallar, V (reprint author), Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. RI Guallar, Victor/B-1579-2013 OI Guallar, Victor/0000-0002-4580-1114 NR 72 TC 47 Z9 47 U1 0 U2 4 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD DEC 1 PY 2000 VL 113 IS 21 BP 9510 EP 9522 DI 10.1063/1.1321049 PG 13 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 378KY UT WOS:000165584600017 ER PT J AU Hankel, M Balint-Kurti, GG Gray, SK AF Hankel, M Balint-Kurti, GG Gray, SK TI Quantum mechanical calculation of product state distributions for the O(D-1)+H-2 -> OH+H reaction on the ground electronic state surface SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID WAVE-PACKET; RESOLVED STEREODYNAMICS; ENERGY-DISTRIBUTION; REACTION DYNAMICS; CROSS-SECTIONS; RATE CONSTANTS; ORDER DOMAIN; SCATTERING; O(1D2); INSERTION AB The real wave packet method is used to calculate reaction probabilities and product quantum state distributions for the reaction O(D-1) + H-2-->OH + H. The method yields the desired quantities over a wide range of energies from a single wave packet propagation. The calculations are performed on the lowest adiabatic electronic potential energy surface for zero total angular momentum (J=0). A capture model is used to estimate reaction probabilities for J>0 based on our J=0 data, and thus permit the approximate calculation of cross sections. Two different ground state surfaces are used and the results from calculations on the two surfaces are compared with each other and with experiment. O 2000 American Institute of Physics. [S0021-9606(00)01544-0]. C1 Univ Bristol, Sch Chem, Bristol BS8 1TS, Avon, England. Argonne Natl Lab, Div Chem, Argonne, IL 60439 USA. RP Hankel, M (reprint author), Univ Bristol, Sch Chem, Cantocks Close, Bristol BS8 1TS, Avon, England. RI Hankel, Marlies/C-6262-2009 OI Hankel, Marlies/0000-0002-8297-7231 NR 54 TC 44 Z9 44 U1 2 U2 7 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD DEC 1 PY 2000 VL 113 IS 21 BP 9658 EP 9667 DI 10.1063/1.1319996 PG 10 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 378KY UT WOS:000165584600032 ER PT J AU Gee, RH Henderson, D Wasan, DT AF Gee, RH Henderson, D Wasan, DT TI The correlation functions of a suspension of large particles in amorphous polybutadiene: A molecular dynamics simulation study SO JOURNAL OF COLLOID AND INTERFACE SCIENCE LA English DT Article DE polymer liquid; amorphous polymers; molecular dynamics; simulation; bulk polybutadienes; colloid; flocculation; suspensions; dispersions; correlation functions ID POLYMER LIQUID; CONFORMATIONAL DYNAMICS; BROWNIAN DYNAMICS; FORCE; GLASS; POLYETHYLENE; POLYISOPRENE; TRANSITIONS; DIFFUSION; SOLVENT AB The correlation functions of a suspension of Lennard-Jones large particles in a model 1,4-cis-polybutadiene solvent have been investigated by molecular dynamics simulations. We present the effects of temperature, the degree of polymerization, and the solvent/ large particle density on the effective interactions between the large particles and the solvent. It is found that as the temperature increases, the structure between solvent-solvent, solvent-large particle, and large-large particle decreases. Additionally, as the bulk density or the chain length is increased, the attractive part of the large-large interaction becomes weaker and small. We believe that in part, this is due to the polymer having collapsed onto itself and entangling the large particles and lessening their interaction until they are actually in contact. Increasing the length of the polymer also entangles the large particles. However, we believe that this may be a general feature that is a characteristic of a polymer solvent containing macroscopically large colloidal particles even though entanglement should be of less significance. (C) 2000 Academic Press. C1 Univ Calif Lawrence Livermore Natl Lab, Chem & Mat Sci Directorate, Livermore, CA 94551 USA. Brigham Young Univ, Dept Chem & Biochem, Provo, UT 84602 USA. IIT, Dept Chem Engn, Chicago, IL 60616 USA. RP Gee, RH (reprint author), Univ Calif Lawrence Livermore Natl Lab, Chem & Mat Sci Directorate, POB 808,L-397, Livermore, CA 94551 USA. NR 25 TC 0 Z9 0 U1 1 U2 2 PU ACADEMIC PRESS INC PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0021-9797 J9 J COLLOID INTERF SCI JI J. Colloid Interface Sci. PD DEC 1 PY 2000 VL 232 IS 1 BP 39 EP 44 DI 10.1006/jcis.2000.7184 PG 6 WC Chemistry, Physical SC Chemistry GA 378RT UT WOS:000165598000006 ER PT J AU Carr, R AF Carr, R TI Some results on node lifting of TSP inequalities SO JOURNAL OF COMBINATORIAL OPTIMIZATION LA English DT Article DE traveling salesman problem; lifting; node lifting; polytope; inequalities AB We can define important classes of TSP inequalities by performing Naddef and Rinaldi's node lifting operation on simple TSP inequalities. We present some new insights into the node lifting operation, namely that 1-node lifting of cut based inequalities always has a geometric interpretation if a certain claw-free condition which is satisfied by most of these TSP inequalities is met. We go on to show that node lifting of the subtour elimination inequalities does not yield any new inequalities. C1 Sandia Natl Labs, Dept Optimizat & Uncertainty Estimat, Albuquerque, NM 87185 USA. RP Carr, R (reprint author), Sandia Natl Labs, Dept Optimizat & Uncertainty Estimat, Mail Stop 1110,POB 5800, Albuquerque, NM 87185 USA. NR 10 TC 1 Z9 1 U1 0 U2 1 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 1382-6905 J9 J COMB OPTIM JI J. Comb. Optim. PD DEC PY 2000 VL 4 IS 4 BP 395 EP 414 DI 10.1023/A:1009830409833 PG 20 WC Computer Science, Interdisciplinary Applications; Mathematics, Applied SC Computer Science; Mathematics GA 369VV UT WOS:000165089200001 ER PT J AU Boggs, PT Tolle, JW AF Boggs, PT Tolle, JW TI Sequential quadratic programming for large-scale nonlinear optimization SO JOURNAL OF COMPUTATIONAL AND APPLIED MATHEMATICS LA English DT Article DE sequential quadratic programming; nonlinear optimization; Newton methods; interior-point methods; local; trust-region methods convergence; global convergence ID CONSTRAINED OPTIMIZATION; NEWTON METHODS; ALGORITHM; CONVERGENCE AB The sequential quadratic programming (SQP) algorithm has been one of the most successful general methods for solving nonlinear constrained optimization problems. We provide an introduction to the general method and show its relationship to recent developments in interior-point approaches, emphasizing large-scale aspects. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Sandia Natl Labs, Comp Sci & Math Res Dept, Livermore, CA 94550 USA. Univ N Carolina, Dept Operat Res & Math, Chapel Hill, NC 27514 USA. RP Boggs, PT (reprint author), Sandia Natl Labs, Comp Sci & Math Res Dept, Livermore, CA 94550 USA. NR 21 TC 72 Z9 84 U1 1 U2 8 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0377-0427 J9 J COMPUT APPL MATH JI J. Comput. Appl. Math. PD DEC 1 PY 2000 VL 124 IS 1-2 BP 123 EP 137 DI 10.1016/S0377-0427(00)00429-5 PG 15 WC Mathematics, Applied SC Mathematics GA 375PT UT WOS:000165411000007 ER PT J AU Potra, FA Wright, SJ AF Potra, FA Wright, SJ TI Interior-point methods SO JOURNAL OF COMPUTATIONAL AND APPLIED MATHEMATICS LA English DT Article ID POLYNOMIAL-TIME ALGORITHM; CONVERGENCE AB The modern era of interior-point methods dates to 1984, when Karmarkar proposed his algorithm for linear programming. In the years since then, algorithms and software for linear programming have become quite sophisticated, while extensions to more general classes of problems, such as convex quadratic programming, semi-definite programming, and nonconvex and nonlinear problems, have reached varying levels of maturity. We review some of the key developments in the area, and include comments on the complexity theory and practical algorithms for linear programming, semi-definite programming, monotone linear complementarity, and convex programming over sets that can be characterized by self-concordant barrier functions. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Argonne Natl Lab, Div Math & Comp Sci, Argonne, IL 60439 USA. Univ Maryland Baltimore Cty, Dept Math & Stat, Baltimore, MD 21250 USA. RP Wright, SJ (reprint author), Argonne Natl Lab, Div Math & Comp Sci, 9700 S Cass Ave, Argonne, IL 60439 USA. NR 32 TC 65 Z9 71 U1 2 U2 6 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0377-0427 J9 J COMPUT APPL MATH JI J. Comput. Appl. Math. PD DEC 1 PY 2000 VL 124 IS 1-2 BP 281 EP 302 DI 10.1016/S0377-0427(00)00433-7 PG 22 WC Mathematics, Applied SC Mathematics GA 375PT UT WOS:000165411000016 ER PT J AU Voegelin, A Vulava, VM Kuhnen, F Kretzschmar, R AF Voegelin, A Vulava, VM Kuhnen, F Kretzschmar, R TI Multicomponent transport of major cations predicted from binary adsorption experiments SO JOURNAL OF CONTAMINANT HYDROLOGY LA English DT Article DE cation exchange; reactive transport; competitive sorption; column technique; modeling; seawater intrusion ID CALCIUM-MAGNESIUM EXCHANGE; MONTMORILLONITIC SOIL; TERNARY EXCHANGE; INTRUSIONS; ISOTHERMS; MODELS AB Accurate modeling of multicomponent sorption and transport of major cations in subsurface porous media is a prerequisite for predicting complex environmental processes, such as the movement of trace metals in soils and aquifers. In this study, various cation exchange models were compared in their ability to predict ternary Ca-Mg-Na transport in an acidic soil from binary Ca, Mg, and Na adsorption data. A flow-through reactor technique was used to measure binary adsorption isotherms of Ca, Mg, and Na over wide concentration ranges of the adsorptive and the respective background cations. High-resolution transport experiments were conducted in water-saturated chromatographic glass columns. Three sorption models based on cation exchange equations were compared: a 1-site Gaines-Thomas (1-GT), a 1-site Rothmund-Kornfeld (1-RK), and a 3-site Gaines-Thomas (3-GT) model. Although the fit of adsorption data was clearly improved, from the 1-GT to the 1-RK to the 3-GT model, transport predictions were overall not improved compared to the 1-GT model. While predictions by the 1-GT and the 3-GT model were virtually identical, predictions by the 1-RK model were partly improved and partly deteriorated. The most simple 1-GT model, therefore, seems to be adequate for predicting multicomponent transport phenomena involving major cations, however, multi-site models may be useful for predicting transport of trace metals in the presence of several major cations. Regardless of the model used, accurate determination of the cation exchange capacity at the pH conditions of interest is extremely critical in cation transport modeling. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Swiss Fed Inst Technol, Inst Terr Ecol, CH-8952 Schlieren, Switzerland. Univ Georgia, Savannah River Ecol Lab, Aiken, SC 29802 USA. RP Kretzschmar, R (reprint author), Swiss Fed Inst Technol, Inst Terr Ecol, Grabenstr 3, CH-8952 Schlieren, Switzerland. RI Voegelin, Andreas/B-4018-2009; Kretzschmar, Ruben/B-4579-2016 OI Voegelin, Andreas/0000-0003-2873-8966; Kretzschmar, Ruben/0000-0003-2587-2430 NR 29 TC 21 Z9 21 U1 0 U2 8 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 DEC PY 2000 VL 46 IS 3-4 BP 319 EP 338 DI 10.1016/S0169-7722(00)00132-7 PG 20 WC Environmental Sciences; Geosciences, Multidisciplinary; Water Resources SC Environmental Sciences & Ecology; Geology; Water Resources GA 389BN UT WOS:000166218900005 ER PT J AU Munkholm, A Stephenson, GB Eastman, JA Auciello, O Murty, MVR Thompson, C Fini, P Speck, JS DenBaars, SP AF Munkholm, A Stephenson, GB Eastman, JA Auciello, O Murty, MVR Thompson, C Fini, P Speck, JS DenBaars, SP TI In situ studies of the effect of silicon on GaN growth modes SO JOURNAL OF CRYSTAL GROWTH LA English DT Article; Proceedings Paper CT 10th International Conference on Metalorganic Vapor Phase Epitaxy (ICMOVPE-X) CY JUN 05-09, 2000 CL HOKKAIDO UNIV, SAPPORO, JAPAN SP Japan Soc Appl Phys, Res Ctr Interface Quantum Electr, Hokkaido Univ, Asahi Glass Fdn, Casio Sci Promot Fdn, Fdn Promot Mat Sci & Technol Japan, Inoue Fdn Sci, Izumi Fdn Sci & Technol, Nippon Steel Glass Fdn Mat Sci, Ogasawara Fdn Sci & Technol, Sapporo City Int Plaza, Air Water Corp, AIXTRON AG, Daido Air Prod Electr Co Ltd, Eiko Engn Corp, EMF Ltd, EPICHEM Ltd, Furukawa Elect Corp, Hitachi Ltd, Hitachi Cable Ltd, Hitachi Plant Engn & Construct Co Ltd, Int Quantum Epitaxy Plc, Kyoto Semicond Corp, Matsushita Elect Ind Co Ltd, Mitsubishi Chem Co Ltd, MOCHEM GmbH, NEC Corp, Nichic Chem Co Ltd, Nippon Sanso Corp, NTT Bas Res Lab, Oki Elect Ind Co Ltd, Rohm Co Ltd, Sony Corp, Sumitomo Elect Ind Ltd, Toshiba Corp, Toyada Gossei Co Ltd, Ube Ind Ltd HO HOKKAIDO UNIV DE GaN; silicon doping; MOCVD; X-ray scattering ID CHEMICAL-VAPOR-DEPOSITION; X-RAY-DIFFRACTION; SURFACE-STRUCTURE; SCATTERING; MORPHOLOGY; AG(111) AB We present real-time X-ray scattering studies of the influence of silicon on the homoepitaxial growth mode of GaN grown by metal-organic vapor-phase epitaxy. Both annealing of Si-doped GaN and surface dosing of GaN with disilane are shown to change the mode of subsequent growth from step-flow to layer-by-layer. By comparing the growth behavior induced by doped layers which have been annealed to that induced by surface dosing, we extract an approximate diffusion coefficient for Si in GaN of 3.5 x 10(-18) cm(2)/s at 810 degreesC. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Argonne Natl Lab, Div Chem, Argonne, IL 60439 USA. Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. No Illinois Univ, Dept Phys, De Kalb, IL 60115 USA. Univ Calif Santa Barbara, Dept Mat, Santa Barbara, CA 93106 USA. RP Munkholm, A (reprint author), Argonne Natl Lab, Div Chem, 9700 S Cass Ave, Argonne, IL 60439 USA. RI Eastman, Jeffrey/E-4380-2011; Speck, James/H-5646-2011; OI Eastman, Jeff/0000-0002-0847-4265; Thompson, Carol/0000-0003-3832-4855 NR 30 TC 12 Z9 13 U1 1 U2 9 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 DEC PY 2000 VL 221 BP 98 EP 105 DI 10.1016/S0022-0248(00)00656-4 PG 8 WC Crystallography; Materials Science, Multidisciplinary; Physics, Applied SC Crystallography; Materials Science; Physics GA 394AG UT WOS:000166501400018 ER PT J AU Kwon, HK Eiting, CJ Lambert, DJH Wong, MM Shelton, BS Zhu, TG Liliental-Weber, Z Benamura, M Dupuis, RD AF Kwon, HK Eiting, CJ Lambert, DJH Wong, MM Shelton, BS Zhu, TG Liliental-Weber, Z Benamura, M Dupuis, RD TI Time-resolved photoluminescence study of GaN grown by metalorganic chemical vapor deposition SO JOURNAL OF CRYSTAL GROWTH LA English DT Article; Proceedings Paper CT 10th International Conference on Metalorganic Vapor Phase Epitaxy (ICMOVPE-X) CY JUN 05-09, 2000 CL HOKKAIDO UNIV, SAPPORO, JAPAN SP Japan Soc Appl Phys, Res Ctr Interface Quantum Electr, Hokkaido Univ, Asahi Glass Fdn, Casio Sci Promot Fdn, Fdn Promot Mat Sci & Technol Japan, Inoue Fdn Sci, Izumi Fdn Sci & Technol, Nippon Steel Glass Fdn Mat Sci, Ogasawara Fdn Sci & Technol, Sapporo City Int Plaza, Air Water Corp, AIXTRON AG, Daido Air Prod Electr Co Ltd, Eiko Engn Corp, EMF Ltd, EPICHEM Ltd, Furukawa Elect Corp, Hitachi Ltd, Hitachi Cable Ltd, Hitachi Plant Engn & Construct Co Ltd, Int Quantum Epitaxy Plc, Kyoto Semicond Corp, Matsushita Elect Ind Co Ltd, Mitsubishi Chem Co Ltd, MOCHEM GmbH, NEC Corp, Nichic Chem Co Ltd, Nippon Sanso Corp, NTT Bas Res Lab, Oki Elect Ind Co Ltd, Rohm Co Ltd, Sony Corp, Sumitomo Elect Ind Ltd, Toshiba Corp, Toyada Gossei Co Ltd, Ube Ind Ltd HO HOKKAIDO UNIV DE time-resolved photoluminescence; GaN; metalorganic chemical vapor deposition; atomic force microscopy; photoluminescence ID DONOR-BOUND EXCITON; RECOMBINATION; SAPPHIRE; EPITAXY; FILMS AB We have investigated the time decay of the photoluminescence (PL) at room temperature of high-quality (HQ) and low-quality (LQ) GaN epitaxial layers grown on sapphire by metalorganic chemical vapor deposition. For undoped and Si-doped HQ GaN, the full-width at half-maximum of the (1 0 2) X-ray diffraction curve is 562 and 427 arcsec and the dislocation density is 4 x 10(8) and 2 x 10(8) cm (- 2), respectively. It is found that the PL of HQ GaN has a higher intensity and decays slower than that of LQ GaN. The PL decay time is found to be much longer in HQ GaN. The dual-exponential decay times are 50 and 250 ps for undoped HQ GaN, and 150 and 740 ps for Si-doped HQ GaN. To our knowledge, the decay times of 150 and 740 ps are the longest ever reported in GaN thin films at room temperature. Furthermore, the characteristics of PL decay with different excitation intensities and laser beam focusing conditions are also reported. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Univ Texas, Microelect Res Ctr, PRC, MERB, Austin, TX 78712 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. USAF, Mat & Mfg Directorate, Res Lab, Wright Patterson AFB, OH 45433 USA. RP Dupuis, RD (reprint author), Univ Texas, Microelect Res Ctr, PRC, MERB, 1-606D-R9900, Austin, TX 78712 USA. RI Liliental-Weber, Zuzanna/H-8006-2012 NR 17 TC 0 Z9 0 U1 0 U2 5 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 DEC PY 2000 VL 221 BP 240 EP 245 PG 6 WC Crystallography; Materials Science, Multidisciplinary; Physics, Applied SC Crystallography; Materials Science; Physics GA 394AG UT WOS:000166501400041 ER PT J AU Bourret-Courchesne, ED Yu, KM Irvine, SJC Stafford, A Rushworth, SA Smith, LM Kanjolia, R AF Bourret-Courchesne, ED Yu, KM Irvine, SJC Stafford, A Rushworth, SA Smith, LM Kanjolia, R TI MOVPE of GaN on sapphire using the alternate precursor 1,1-dimethylhydrazine SO JOURNAL OF CRYSTAL GROWTH LA English DT Article; Proceedings Paper CT 10th International Conference on Metalorganic Vapor Phase Epitaxy (ICMOVPE-X) CY JUN 05-09, 2000 CL HOKKAIDO UNIV, SAPPORO, JAPAN SP Japan Soc Appl Phys, Res Ctr Interface Quantum Electr, Hokkaido Univ, Asahi Glass Fdn, Casio Sci Promot Fdn, Fdn Promot Mat Sci & Technol Japan, Inoue Fdn Sci, Izumi Fdn Sci & Technol, Nippon Steel Glass Fdn Mat Sci, Ogasawara Fdn Sci & Technol, Sapporo City Int Plaza, Air Water Corp, AIXTRON AG, Daido Air Prod Electr Co Ltd, Eiko Engn Corp, EMF Ltd, EPICHEM Ltd, Furukawa Elect Corp, Hitachi Ltd, Hitachi Cable Ltd, Hitachi Plant Engn & Construct Co Ltd, Int Quantum Epitaxy Plc, Kyoto Semicond Corp, Matsushita Elect Ind Co Ltd, Mitsubishi Chem Co Ltd, MOCHEM GmbH, NEC Corp, Nichic Chem Co Ltd, Nippon Sanso Corp, NTT Bas Res Lab, Oki Elect Ind Co Ltd, Rohm Co Ltd, Sony Corp, Sumitomo Elect Ind Ltd, Toshiba Corp, Toyada Gossei Co Ltd, Ube Ind Ltd HO HOKKAIDO UNIV DE dimethylhydrazine; organometallic vapor-phase epitaxy (OMVPE); gallium nitride (GaN); pyrolysis; adduct; morphology; precursor ID CHEMICAL-VAPOR-DEPOSITION; PHASE EPITAXY; LASER-DIODES; CUBIC GAN; GROWTH; DIMETHYLHYDRAZINE; MOCVD; TRIMETHYLGALLIUM; PYROLYSIS; GAAS AB To date, the most successful method to grow device-quality GaN epitaxial layers by metal-organic vapor-phase epitaxy (MOVPE) uses trimethyl (or triethyl) gallium (Me3Ga/Et-3 Ga) for the Ga source and ammonia (NH3) for the N source. It is a high-temperature process with deposition temperatures typically in excess of 1000 degreesC due to the high stability of the ammonia molecule. The use of a nitrogen precursor that decomposes at lower temperature is expected to result in a more efficient process and to allow growth of alloys at a lower temperature. The liquid precursor 1,1-dimethylhydrazine (Me-2 NNH2) has been tested as such an alternative precursor. GaN epilayers have been grown successfully on c-plane sapphire using low V/III ratio. The growth parameters and the characteristics of the grown epilayers are presented. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Ctr Adv Mat, Berkeley, CA 94720 USA. NE Wales Inst, Wrexham, Wales. Epichem Ltd, Wirral CH62 3QF, Merseyside, England. Epichem Inc, Haverhill, MA 01835 USA. RP Bourret-Courchesne, ED (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Ctr Adv Mat, 1 Cyclotron Rd,Mailstop 2-200, Berkeley, CA 94720 USA. RI Yu, Kin Man/J-1399-2012 OI Yu, Kin Man/0000-0003-1350-9642 NR 21 TC 2 Z9 2 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-0248 J9 J CRYST GROWTH JI J. Cryst. Growth PD DEC PY 2000 VL 221 BP 246 EP 250 DI 10.1016/S0022-0248(00)00693-X PG 5 WC Crystallography; Materials Science, Multidisciplinary; Physics, Applied SC Crystallography; Materials Science; Physics GA 394AG UT WOS:000166501400042 ER PT J AU Pawlowski, RP Theodoropoulos, C Salinger, AG Mountziaris, TJ Moffat, HK Shadid, JN Thrush, EJ AF Pawlowski, RP Theodoropoulos, C Salinger, AG Mountziaris, TJ Moffat, HK Shadid, JN Thrush, EJ TI Fundamental models of the metalorganic vapor-phase epitaxy of gallium nitride and their use in reactor design SO JOURNAL OF CRYSTAL GROWTH LA English DT Article; Proceedings Paper CT 10th International Conference on Metalorganic Vapor Phase Epitaxy (ICMOVPE-X) CY JUN 05-09, 2000 CL HOKKAIDO UNIV, SAPPORO, JAPAN SP Japan Soc Appl Phys, Res Ctr Interface Quantum Electr, Hokkaido Univ, Asahi Glass Fdn, Casio Sci Promot Fdn, Fdn Promot Mat Sci & Technol Japan, Inoue Fdn Sci, Izumi Fdn Sci & Technol, Nippon Steel Glass Fdn Mat Sci, Ogasawara Fdn Sci & Technol, Sapporo City Int Plaza, Air Water Corp, AIXTRON AG, Daido Air Prod Electr Co Ltd, Eiko Engn Corp, EMF Ltd, EPICHEM Ltd, Furukawa Elect Corp, Hitachi Ltd, Hitachi Cable Ltd, Hitachi Plant Engn & Construct Co Ltd, Int Quantum Epitaxy Plc, Kyoto Semicond Corp, Matsushita Elect Ind Co Ltd, Mitsubishi Chem Co Ltd, MOCHEM GmbH, NEC Corp, Nichic Chem Co Ltd, Nippon Sanso Corp, NTT Bas Res Lab, Oki Elect Ind Co Ltd, Rohm Co Ltd, Sony Corp, Sumitomo Elect Ind Ltd, Toshiba Corp, Toyada Gossei Co Ltd, Ube Ind Ltd HO HOKKAIDO UNIV DE MOVPE; gallium nitride; models; kinetics; reactor design ID DEVICES; BLUE AB A fundamental reaction-transport model describing the metalorganic vapor-phase epitaxy (MOVPE) of GaN from trimethyl-gallium (TMG) and ammonia has been developed. This model has been tested against experimental data from research-scale and industrial-scale reactors. A simplified version of the model that includes only transport phenomena and a unity sticking coefficient of the limiting film precursor (TMG) to the surface of the growing film was found to accurately capture observed film deposition variations in an early variant of the Thomas Swan close-coupled-shower-head 3 x 2 " reactor. Modifications of the Thomas Swan reactor, in line with the findings suggested by this work, enabled state-of-the-art thickness uniformity to be achieved. The model has been used to develop performance diagrams for conceptual multi-aperture MOVPE reactors and for the Thomas Swan system. These performance diagrams identify regions of the parameter space of the reactor which correspond to minimal variations in film growth rate across large-area substrates. Published by Elsevier Science B.V. C1 SUNY Buffalo, Dept Chem Engn, Buffalo, NY 14260 USA. Sandia Natl Labs, Albuquerque, NM 87185 USA. Thomas Swan Sci Equipment Ltd, Cambridge, England. RP Mountziaris, TJ (reprint author), SUNY Buffalo, Dept Chem Engn, Buffalo, NY 14260 USA. OI Theodoropoulos, Constantinos/0000-0003-3249-0422 NR 9 TC 34 Z9 36 U1 1 U2 12 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 DEC PY 2000 VL 221 BP 622 EP 628 DI 10.1016/S0022-0248(00)00789-2 PG 7 WC Crystallography; Materials Science, Multidisciplinary; Physics, Applied SC Crystallography; Materials Science; Physics GA 394AG UT WOS:000166501400111 ER PT J AU Lambert, DJH Huang, JJ Shelton, BS Wong, MM Chowdhury, U Zhu, TG Kwon, HK Liliental-Weber, Z Benarama, M Feng, M Dupuis, RD AF Lambert, DJH Huang, JJ Shelton, BS Wong, MM Chowdhury, U Zhu, TG Kwon, HK Liliental-Weber, Z Benarama, M Feng, M Dupuis, RD TI The growth of AlGaN/GaN heterojunction bipolar transistors by metalorganic chemical vapor deposition SO JOURNAL OF CRYSTAL GROWTH LA English DT Article; Proceedings Paper CT 10th International Conference on Metalorganic Vapor Phase Epitaxy (ICMOVPE-X) CY JUN 05-09, 2000 CL HOKKAIDO UNIV, SAPPORO, JAPAN SP Japan Soc Appl Phys, Res Ctr Interface Quantum Electr, Hokkaido Univ, Asahi Glass Fdn, Casio Sci Promot Fdn, Fdn Promot Mat Sci & Technol Japan, Inoue Fdn Sci, Izumi Fdn Sci & Technol, Nippon Steel Glass Fdn Mat Sci, Ogasawara Fdn Sci & Technol, Sapporo City Int Plaza, Air Water Corp, AIXTRON AG, Daido Air Prod Electr Co Ltd, Eiko Engn Corp, EMF Ltd, EPICHEM Ltd, Furukawa Elect Corp, Hitachi Ltd, Hitachi Cable Ltd, Hitachi Plant Engn & Construct Co Ltd, Int Quantum Epitaxy Plc, Kyoto Semicond Corp, Matsushita Elect Ind Co Ltd, Mitsubishi Chem Co Ltd, MOCHEM GmbH, NEC Corp, Nichic Chem Co Ltd, Nippon Sanso Corp, NTT Bas Res Lab, Oki Elect Ind Co Ltd, Rohm Co Ltd, Sony Corp, Sumitomo Elect Ind Ltd, Toshiba Corp, Toyada Gossei Co Ltd, Ube Ind Ltd HO HOKKAIDO UNIV DE Heterojunction bipolar transistor; aluminum gallium nitride; current gain ID JUNCTION TRANSISTOR; OHMIC CONTACTS; GAN AB The growth and properties of AlGaN/GaN heterojunction bipolar transistors grown by low-pressure metalorganic chemical vapor deposition (MOCVD) are described. The "emitter-up" structures are grown on (0 0 0 1) sapphire substrates, Common-emitter characteristics and Gummel plots were measured on 120 x 120 mum(2) devices and useable DC current gains of beta similar to 8-14 were achieved at room temperature. The resistance of the base was a limiting factor in high-current operation of these devices. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Univ Texas, Microelect Res Ctr, Austin, TX 78712 USA. Univ Illinois, Ctr Compound Semicond Microelect, Urbana, IL 61801 USA. Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. RP Dupuis, RD (reprint author), Univ Texas, Microelect Res Ctr, Austin, TX 78712 USA. RI Liliental-Weber, Zuzanna/H-8006-2012 NR 12 TC 6 Z9 6 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-0248 J9 J CRYST GROWTH JI J. Cryst. Growth PD DEC PY 2000 VL 221 BP 730 EP 733 DI 10.1016/S0022-0248(00)00808-3 PG 4 WC Crystallography; Materials Science, Multidisciplinary; Physics, Applied SC Crystallography; Materials Science; Physics GA 394AG UT WOS:000166501400130 ER PT J AU Battaglia, LL Fore, SA Sharitz, RR AF Battaglia, LL Fore, SA Sharitz, RR TI Seedling emergence, survival and size in relation to light and water availability in two bottomland hardwood species SO JOURNAL OF ECOLOGY LA English DT Article DE disturbance; floodplain; forest regeneration; light; microsites; microtopography ID EXPERIMENTAL HURRICANE BLOWDOWN; WOODY PLANT-REGENERATION; CANOPY-TREE SEEDLINGS; FLOODPLAIN FORESTS; SOUTH-CAROLINA; ECOLOGICAL FILTER; FERN UNDERSTORY; RAIN-FOREST; GROWTH; DYNAMICS AB 1 Windstorm disturbances create a wide range of microsites which can have complex effects on forest regeneration patterns. We investigated the combined effects of light and microtopography on emergence, mortality and size of seedlings of two bottomland hardwood canopy tree species, Quercus michauxii and Liquidambar styraciflua, over a 2-year period. A split-plot design in experimental tanks represented the range of light levels and the pits and mounds found in a disturbed floodplain forest. 2 Emergence was always higher on mounds than in pits, except for L. styraciflua in full sunlight. For both species, mortality was consistently lower, and seedlings of both species grew better in both years on mounds. Light levels did not affect the two later stages. 3 There were species-specific interactions between the effects of two factors on seedling emergence, Lower emergence of L. styraciflua on mounds in full sunlight suggested that full sunlight at this stage can eliminate the advantage to later stages of being on a mound. The combined stresses of low light and a high water table significantly reduced emergence of Q. michauxii in pits at low light. 4 Microsites optimal, for one regeneration component of a species were not always optimal for others as seen for L. styraciflua. The relative significance of environmental factors also varied with regeneration stages, such that neither light nor a light-water interaction influenced regeneration after emergence. 5 Environmental factors may have independent or interacting effects on regeneration, and the nature or presence of these effects can vary among demographic stages. Within each environmental combination, effects may be consistently positive or negative across stages; alternatively, demographic conflicts may develop. C1 Univ Georgia, Savannah River Ecol Lab, Aiken, SC 29802 USA. Truman State Univ, Div Sci, Kirksville, MO 63501 USA. RP Louisiana State Univ, Dept Biol Sci, 508 Life Sci Bldg, Baton Rouge, LA 70803 USA. EM 1battal@lsu.edu NR 52 TC 60 Z9 62 U1 4 U2 30 PU WILEY-BLACKWELL PI HOBOKEN PA 111 RIVER ST, HOBOKEN 07030-5774, NJ USA SN 0022-0477 EI 1365-2745 J9 J ECOL JI J. Ecol. PD DEC PY 2000 VL 88 IS 6 BP 1041 EP 1050 DI 10.1046/j.1365-2745.2000.00518.x PG 10 WC Plant Sciences; Ecology SC Plant Sciences; Environmental Sciences & Ecology GA 399DJ UT WOS:000166795700009 ER PT J AU Dunn, JH Arvanitis, D Baberschke, K Hahlin, A Karis, O Carr, R Martensson, N AF Dunn, JH Arvanitis, D Baberschke, K Hahlin, A Karis, O Carr, R Martensson, N TI A comparative study of X-ray absorption spectroscopy at various synchrotron facilities and the effect of transverse source coherence SO JOURNAL OF ELECTRON SPECTROSCOPY AND RELATED PHENOMENA LA English DT Article ID FINE-STRUCTURE; MAGNETISM; FE; CO; DIFFRACTION; UNDULATOR; SPECKLE; NI AB Core level X-ray Absorption Spectroscopy measurements have been performed at the L-3,L-2 edges of thin film Fe samples deposited on the (100) surface of Cu. Soft X-rays from five different beamlines have been used to measure spectra from identical samples with very different degrees of transverse coherence in the synchrotron radiation. The degree of source coherence has been characterised by diffraction. The transverse coherence length has been extracted and found to be on the mum length scale at certain beamlines. An increase of the L edge resonance intensities, relative to the continuum states, is observed in spectra measured at these beamlines. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Stanford Univ, Stanford Linear Accelerator Ctr, Stanford Synchrotron Radiat Lab, Stanford, CA 94309 USA. Univ Uppsala, Dept Phys, S-75121 Uppsala, Sweden. RP Dunn, JH (reprint author), Stanford Univ, Stanford Linear Accelerator Ctr, Stanford Synchrotron Radiat Lab, Stanford, CA 94309 USA. NR 30 TC 3 Z9 3 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0368-2048 J9 J ELECTRON SPECTROSC JI J. Electron Spectrosc. Relat. Phenom. PD DEC PY 2000 VL 113 IS 1 BP 67 EP 77 PG 11 WC Spectroscopy SC Spectroscopy GA 382DP UT WOS:000165804700008 ER PT J AU Huff, DD Hargrove, B Tharp, ML Graham, R AF Huff, DD Hargrove, B Tharp, ML Graham, R TI Managing forests for water yield - The importance of scale SO JOURNAL OF FORESTRY LA English DT Article AB Examination of expected changes in water yield for a large area where vegetation thinning has been proposed in the Sierra Mountains of California indicates that the size of the area has an important bearing on annual runoff. At the smallest scales, some treated areas may have easily measured changes in water yield, with the potential for impacts on aquatic biota and water quality. The average changes in annual runoff per unit area for large tracts, however, are too small to be measured directly and thus must be quantified by using models to extrapolate existing knowledge. C1 Oak Ridge Natl Lab, Computat Phys & Engn Div, Oak Ridge, TN 37831 USA. Oak Ridge Natl Lab, Div Environm Sci, Ecosyst & Plant Sci Sect, Oak Ridge, TN 37831 USA. RP Huff, DD (reprint author), Oak Ridge Natl Lab, Computat Phys & Engn Div, Oak Ridge, TN 37831 USA. NR 10 TC 4 Z9 4 U1 0 U2 4 PU SOC AMER FORESTERS PI BETHESDA PA 5400 GROSVENOR LANE, BETHESDA, MD 20814 USA SN 0022-1201 J9 J FOREST JI J. For. PD DEC PY 2000 VL 98 IS 12 BP 15 EP 19 PG 5 WC Forestry SC Forestry GA 418PD UT WOS:000167899800005 ER PT J AU Baker, CC Dean, SO Ellis, WR Hazeltine, RD Logan, BG Mauel, M Sauthoff, N Taylor, T AF Baker, CC Dean, SO Ellis, WR Hazeltine, RD Logan, BG Mauel, M Sauthoff, N Taylor, T TI Report of the Integrated Program Planning Activity for the US Department of Energy Fusion Energy Sciences Program SO JOURNAL OF FUSION ENERGY LA English DT Article DE fusion energy; fusion program planning AB This report of the Integrated Program Planning Activity (IPPA) has been prepared in response to a recommendation by the Secretary of Energy Advisory Board that, "Given the complex nature of the fusion effort, an integrated program planning process is an absolute necessity." We therefore undertook this activity to integrate the various elements of the program, to improve communication and performance accountability across the program, and to show the interconnectedness and interdependency of the diverse parts of the national Fusion Energy Sciences Program. This report is based on the September 1999 Fusion Energy Sciences Advisory Committee's (FESAC) report "Priorities and Balance within the Fusion Energy Sciences Program." In its December 5, 2000, letter to the Director of the Office of Science, the FESAC reaffirmed the validity of the September 1999 report and stated that the IPPA presents a framework and process to guide the achievement of the 5-year goals listed in the 1999 report. The report also outlines a process for establishing a database for the fusion research program that will indicate how each research element fits into the overall program. This database will also include near-term milestones associated with each research element and will facilitate assessments of the balance within the program at different levels. C1 Univ Calif San Diego, La Jolla, CA 92093 USA. Fus Power Associates, Gaithersburg, MD 20879 USA. Raytheon Tech Serv Co, Lanham, MD 20706 USA. Univ Texas, Austin, TX 78712 USA. Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. Columbia Univ, New York, NY 10027 USA. Princeton Univ, Plasma Phys Lab, Princeton, NJ 08543 USA. Gen Atom Co, San Diego, CA 92186 USA. RP Baker, CC (reprint author), Univ Calif San Diego, La Jolla, CA 92093 USA. OI Mauel, Michael/0000-0003-2490-7478 NR 0 TC 1 Z9 1 U1 0 U2 2 PU KLUWER ACADEMIC/PLENUM PUBL PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 0164-0313 J9 J FUSION ENERG JI J. Fusion Energy PD DEC PY 2000 VL 19 IS 3-4 BP 169 EP 228 AR UNSP 0164-0313/02/1200-0169/0 DI 10.1023/A:1015210800836 PG 60 WC Nuclear Science & Technology SC Nuclear Science & Technology GA 549QX UT WOS:000175457900001 ER PT J AU Sheffield, J Antonsen, TM Berry, LA Brown, MR Dahlburg, JP Davidson, RC Greenwald, M Hegna, CC McCurdy, W Newman, DE Pellegrini, C Phillips, CK Post, DE Rosenbluth, MN Simonen, TC Van Dam, J AF Sheffield, J Antonsen, TM Berry, LA Brown, MR Dahlburg, JP Davidson, RC Greenwald, M Hegna, CC McCurdy, W Newman, DE Pellegrini, C Phillips, CK Post, DE Rosenbluth, MN Simonen, TC Van Dam, J TI Report of the US Department of Energy Fusion Energy Sciences Advisory Committee (FESAC) Panel reviewing the theory and computing program SO JOURNAL OF FUSION ENERGY LA English DT Article DE fusion energy; fusion theory; fusion computation AB This Panel was set up by the Fusion Energy Sciences Advisory Committee (FESAC) at its November 2000 meeting for the purpose of addressing questions from the Department of Energy concerning the theory and computing/simulation program of the Office of Fusion Energy Sciences. Although the Panel primarily addressed programmatic questions, it acknowledges that the theory and computing in fusion energy sciences has a stellar record of research successes. (A recent FESAC report entitled "Opportunities in the Fusion Energy Sciences Program" listed a number of theory and computing research highlights.) Last year the National Research Council performed an assessment of the quality of the fusion energy sciences program-including theory and computing-and concluded that the quality of its research is on a par with that of other leading areas of contemporary physical science. C1 Oak Ridge Natl Lab, Div Fus Energy, Oak Ridge, TN 37831 USA. Univ Tennessee, Joint Inst Energy & Environm, Oak Ridge, TN 37831 USA. Univ Maryland, Inst Plasma Res, College Pk, MD 20742 USA. Swarthmore Coll, Dept Phys & Astron, Swarthmore, PA 19081 USA. Gen Atom Co, San Diego, CA 92186 USA. Princeton Univ, Plasma Phys Lab, Princeton, NJ 08543 USA. MIT, Plasma Sci & Fus Ctr, Cambridge, MA 02139 USA. Univ Wisconsin, Dept Engn Phys, Madison, WI 53706 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Natl Energy Res Supercomp Ctr, Berkeley, CA 94720 USA. Univ Alaska, Dept Phys, Fairbanks, AK 99775 USA. Univ Calif Los Angeles, Dept Phys & Astron, Los Angeles, CA 90095 USA. Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Univ Calif San Diego, Dept Phys, La Jolla, CA 92093 USA. Univ Texas, Inst Fus Studies, Austin, TX 78712 USA. RP Sheffield, J (reprint author), Oak Ridge Natl Lab, Div Fus Energy, Oak Ridge, TN 37831 USA. RI Post, Douglass/L-3773-2014; Antonsen, Thomas/D-8791-2017; OI Post, Douglass/0000-0001-9271-0023; Antonsen, Thomas/0000-0002-2362-2430; Greenwald, Martin/0000-0002-4438-729X NR 0 TC 0 Z9 0 U1 0 U2 1 PU KLUWER ACADEMIC/PLENUM PUBL PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 0164-0313 J9 J FUSION ENERG JI J. Fusion Energy PD DEC PY 2000 VL 19 IS 3-4 BP 229 EP 244 AR UNSP 0164-0313/00/1200-0229/0 DI 10.1023/A:1015278617675 PG 16 WC Nuclear Science & Technology SC Nuclear Science & Technology GA 549QX UT WOS:000175457900002 ER PT J AU Freidberg, JP Berk, HL Betti, R Dahlburg, JP Hooper, EB Meade, DM Navratil, G Nevins, WM Ono, M Perkins, FW Prager, S Schoenburg, K Taylor, TS Uckan, NA AF Freidberg, JP Berk, HL Betti, R Dahlburg, JP Hooper, EB Meade, DM Navratil, G Nevins, WM Ono, M Perkins, FW Prager, S Schoenburg, K Taylor, TS Uckan, NA TI Report of the US Department of Energy Fusion Energy Sciences Advisory Committee Panel on burning plasma physics SO JOURNAL OF FUSION ENERGY LA English DT Article DE fusion burning plasmas; fusion ignition ID FEAT AB This is the report of a panel set up by the U.S. Department of Energy Fusion Energy Sciences Advisory Committee (FESAC) in response to a charge letter on October 5, 2000, from Dr. Mildred Dresselhaus, then Director of the DOE's Office of Science. In that letter, Dr. Dresselhaus asked the FESAC to investigate the subject of burning plasma science. The report addresses several topics, including the scientific issues to be addressed by a burning plasma experiment and its major supporting elements, identification of issues that are generic to toroidal confinement, and the role of the Next-Step Options (NSO) Program. C1 MIT, Cambridge, MA 02139 USA. Univ Texas, Austin, TX 78712 USA. Univ Rochester, Rochester, NY 14623 USA. Gen Atom Co, San Diego, CA 92186 USA. Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. Princeton Univ, Plasma Phys Lab, Princeton, NJ 08543 USA. Columbia Univ, New York, NY 10027 USA. Univ Wisconsin, Madison, WI 53706 USA. Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Freidberg, JP (reprint author), MIT, 77 Massachusetts Ave, Cambridge, MA 02139 USA. NR 15 TC 0 Z9 0 U1 0 U2 1 PU KLUWER ACADEMIC/PLENUM PUBL PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 0164-0313 J9 J FUSION ENERG JI J. Fusion Energy PD DEC PY 2000 VL 19 IS 3-4 BP 245 EP 292 AR UNSP 0164-0313/00/1200-0245/0 DI 10.1023/A:1015230701745 PG 48 WC Nuclear Science & Technology SC Nuclear Science & Technology GA 549QX UT WOS:000175457900003 ER PT J AU Shodhan, S Crooker, NU Kahler, SW Fitzenreiter, RJ Larson, DE Lepping, RP Siscoe, GL Gosling, JT AF Shodhan, S Crooker, NU Kahler, SW Fitzenreiter, RJ Larson, DE Lepping, RP Siscoe, GL Gosling, JT TI Counterstreaming electrons in magnetic clouds SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID CORONAL MASS EJECTION; HEAT-FLUX DROPOUTS; SOLAR-WIND; FIELD; TOPOLOGY; RECONNECTION; EVENTS; SHOCK AB Two widely used signatures of interplanetary coronal mass ejections are counterstreaming suprathermal electrons, implying magnetic structures connected to the Sun at both ends, and magnetic clouds, characterized by large-scale field rotations, low temperature, and high field strength. In order to determine to what extent these signatures coincide, electron heat flux data were examined for 14 magnetic clouds detected by ISEE 3 and IMP 8 near solar maximum and 34 clouds detected by Wind near solar minimum. The percentage of time during each cloud passage that counterstreaming electrons were detected varied widely, from 6 clouds with essentially no counterstreaming to 8 clouds with nearly 100% counterstreaming. All of the former but less than half of the latter occurred near solar minimum, suggesting a possible solar cycle dependence on the degree of magnetic openness. The counterstreaming intervals were distributed randomly throughout the clouds, with a median length of 2.5 hours. A plot of counterstreaming percentages against cloud diameter for 33 clouds modeled as cylindrical flux ropes indicates a linear dependence of the percentage of closed flux on cloud size, with the largest clouds being the most closed. Overall the results are consistent with the view that although magnetic field lines within a magnetic cloud can form a large-scale, coherent structure, reconnection in remote regions of the structure, presumably near the Sun, sporadically alters its topology fi om closed to open until the cloud assimilates into the ambient solar wind. C1 Boston Univ, Ctr Space Phys, Boston, MA 02215 USA. NASA, Goddard Space Flight Ctr, Extraterr Phys Lab, Greenbelt, MD 20771 USA. Los Alamos Natl Lab, Grp NIS 1, Los Alamos, NM 87545 USA. USAF, Res Lab, Space Vehicles Directorate, Hanscom AFB, MA USA. Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA. RP Shodhan, S (reprint author), Boston Univ, Ctr Space Phys, 725 Commonwealth Ave, Boston, MA 02215 USA. EM shodhan@.bu.edu; crooker@bu.edu; kahler@plh.af.mil; u3rjf@leprjf.gsfc.nasa.gov; davin@ssl.berkeley.edu; rpl@leprpl.gsfc.nasa.gov; siscoe@bu.edu; jgosling@lanl.gov NR 33 TC 69 Z9 70 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0148-0227 J9 J GEOPHYS RES-SPACE JI J. Geophys. Res-Space Phys. PD DEC 1 PY 2000 VL 105 IS A12 BP 27261 EP 27268 DI 10.1029/2000JA000060 PG 8 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 386BL UT WOS:000166040200015 ER PT J AU Skoug, RM Feldman, WC Gosling, JT McComas, DJ Reisenfeld, DB Smith, CW Lepping, RP Balogh, A AF Skoug, RM Feldman, WC Gosling, JT McComas, DJ Reisenfeld, DB Smith, CW Lepping, RP Balogh, A TI Radial variation of solar wind electrons inside a magnetic cloud observed at 1 and 5 AU SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID ULYSSES OBSERVATIONS; VOYAGER 2; PLASMA; PROPAGATION; EVOLUTION; LOOP; FLUX AB The fortuitous observations of a magnetic cloud during the ACE/Ulysses radial alignment in March 1998 provide one of the first opportunities to study the same magnetic cloud at two different radial distances. In this paper, we use data from both ACE and Ulysses to examine the expansion of the cloud as well as of the adjacent noncloud solar wind. In particular, we study the evolution of the electrons as the cloud expanded from 1 to 5.4 AU, including the core, halo, and total electron populations. We find that the core and total electron temperatures at either spacecraft are moderately anticorrelated with electron density. However, combined observations from the two spacecraft show that both temperature and density decreased as the cloud expanded and thus that single point measurements cannot be used to determine a polytropic index describing the expansion of solar wind electrons within the cloud. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Univ London Imperial Coll Sci Technol & Med, Blackett Lab, London SW7 2BZ, England. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Univ Delaware, Bartol Res Inst, Newark, DE 19716 USA. RP Skoug, RM (reprint author), Univ Calif Los Alamos Natl Lab, MS D466, Los Alamos, NM 87545 USA. RI Reisenfeld, Daniel/F-7614-2015 NR 31 TC 30 Z9 31 U1 0 U2 4 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0148-0227 J9 J GEOPHYS RES-SPACE JI J. Geophys. Res-Space Phys. PD DEC 1 PY 2000 VL 105 IS A12 BP 27269 EP 27275 DI 10.1029/2000JA000095 PG 7 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 386BL UT WOS:000166040200016 ER PT J AU Arkani-Hamed, N Dimopoulos, S Kaloper, N Dvali, G AF Arkani-Hamed, N Dimopoulos, S Kaloper, N Dvali, G TI Manyfold universe SO JOURNAL OF HIGH ENERGY PHYSICS LA English DT Article DE field theories in higher dimensions; extra large dimensions; cosmology of theories beyond the SM; physics of the early universe ID LARGE EXTRA DIMENSIONS; BIG-BANG NUCLEOSYNTHESIS; SCALE QUANTUM-GRAVITY; ASSISTED CHAOTIC INFLATION; LARGE COMPACT DIMENSIONS; TEV-SCALE; NEUTRINO OSCILLATIONS; SUBMILLIMETER DIMENSIONS; BRANE-UNIVERSE; DOMAIN-WALLS AB We propose that our world is a brane folded many times inside the sub-millimeter extra dimensions. The folding produces many connected parallel branes or folds with identical microphysics - a Manyfold. Nearby matter on other folds can be detected gravitationally as dark matter since the light it emits takes a long time to reach us traveling around the fold. Hence dark matter is microphysically identical to ordinary matter; it can dissipate and clump possibly forming dark replicas of ordinary stars which are good MACHO candidates. Its dissipation may lead to far more frequent occurrence of gravitational collapse and consequently to a significant enhancement in gravitational wave signals detectable by LIGO and LISA. Sterile neutrinos find a natural home on the other folds. Since the folded brane is not a BPS state, it gives a new geometric means for supersymmetry breaking in our world. It may also offer novel approach for the resolution of the cosmological horizon problem, although it still requires additional dynamics to solve the flatness problem. Although there are constraints from BBN, structure formation, the enormity of galactic halos and the absence of stars and globular clusters with a discernible dark matter component, we show that the model is consistent with current observational limits. It presents us with a new dark matter particle and a new framework for the evolution of structure in our universe. C1 Univ Calif Berkeley, Dept Phys, Berkeley, CA 94530 USA. Stanford Univ, Dept Phys, Stanford, CA 94305 USA. NYU, Dept Phys, New York, NY 10003 USA. RP Arkani-Hamed, N (reprint author), Lawrence Berkeley Lab, Theory Grp, Berkeley, CA 94530 USA. EM arkani@thsrv.lbl.gov; savas@stanford.edu; kaloper@epic.stanford.edu; gd23@scires.acf.nyu.edu NR 65 TC 27 Z9 27 U1 0 U2 1 PU SPRINGER PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 1029-8479 J9 J HIGH ENERGY PHYS JI J. High Energy Phys. PD DEC PY 2000 IS 12 AR 010 PG 30 WC Physics, Particles & Fields SC Physics GA 423EC UT WOS:000168161600010 ER PT J AU Hsieh, HB Weier, HUG AF Hsieh, HB Weier, HUG TI Expression profiling of tyrosine kinase genes by FISH and chips SO JOURNAL OF HISTOCHEMISTRY & CYTOCHEMISTRY LA English DT Meeting Abstract C1 Lawrence Berkeley Lab, Berkeley, CA USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU HISTOCHEMICAL SOC INC PI SEATTLE PA UNIV WASHINGTON, DEPT BIOSTRUCTURE, BOX 357420, SEATTLE, WA 98195 USA SN 0022-1554 J9 J HISTOCHEM CYTOCHEM JI J. Histochem. Cytochem. PD DEC PY 2000 VL 48 IS 12 MA 36 BP 1729 EP 1730 PG 2 WC Cell Biology SC Cell Biology GA 384BV UT WOS:000165919900050 ER PT J AU Patrinos, AA AF Patrinos, AA TI The Human Genome Project: Interaction of the physical sciences with biology SO JOURNAL OF LAW MEDICINE & ETHICS LA English DT Article; Proceedings Paper CT Symposium on Genes and Society - Impact of New Technologies on Lae, Medicine and Policy CY MAY 10-12, 2000 CL MIT, CAMBRIDGE, MASSACHUSETTS SP Whitehead Inst Biomed Res, George Washington Univ Med Ctr, Amer Soc Law, Med & Ethics HO MIT C1 US Dept Energy, Off Sci, Washington, DC USA. RP Patrinos, AA (reprint author), US Dept Energy, Off Sci, Washington, DC USA. NR 0 TC 1 Z9 1 U1 0 U2 0 PU AMER SOC LAW MEDICINE ETHICS PI BOSTON PA 765 COMMONWEALTH AVE, 16TH FL, BOSTON, MA 02215 USA SN 1073-1105 J9 J LAW MED ETHICS JI J. Law Med. Ethics PD WIN PY 2000 VL 28 IS 4 SU S BP 54 EP 64 PG 11 WC Ethics; Law; Medical Ethics; Medicine, Legal SC Social Sciences - Other Topics; Government & Law; Medical Ethics; Legal Medicine GA 432NQ UT WOS:000168698300008 PM 11244845 ER PT J AU Mendez, AJ Gagliardi, RM Feng, HXC Heritage, JP Morookian, JM AF Mendez, AJ Gagliardi, RM Feng, HXC Heritage, JP Morookian, JM TI Strategies for realizing optical CDMA for dense, high-speed, long span, optical network applications SO JOURNAL OF LIGHTWAVE TECHNOLOGY LA English DT Article DE access protocols; code division multiaccess; codes; encoding; multiaccess communication; optical fiber communication; optical fiber dispersion; propagation ID ULTRASHORT LIGHT-PULSE; FIBER; SYSTEMS; TRANSMISSION AB Since the mid 1990s, the role of optical CDMA has expanded from local area networks to longer span, telecommunication-type networks. In order to play a significant role in these longer span, denser, higher data rate networks, optical CDMA code set must 1) have at least as many codes as dense wavelength division multiplexing (WDM) (i.e., more than eight codes); 2) operate at high data rates (i.e., greater than 2.5 Gb/s); and 3) propagate with high fidelity over the installed or installable fiber links. Most approaches to optical CDMA require narrow pulses, which are more susceptible to fiber impairments and may have lower spectral efficiency than conventional WDM modulation schemes such as nonreturn-to-zero (NRZ), so they do not meet these new requirements. Therefore, we have formulated a strategy which simultaneously increases the number of good codes (resulting in higher density) and reduces their code length (i.e., decreasing the number of time slots required thus enabling higher data rates for a given chip time): the strategy of matrix codes. In this paper, we describe the design of a set of eight matrix codes for operation at 2.5 Gb/s and evaluate their propagation over an existing 214 km network link by means of computer simulation, The results indicate that the codes propagate well if dispersion management is used. The paper also discusses a strategy for managing the multiaccess interference (MAI) in a bursty traffic environment. C1 MRDA, El Segundo, CA 90245 USA. Univ So Calif, Los Angeles, CA 90089 USA. Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. Univ Calif Davis, Davis, CA 95616 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Mendez, AJ (reprint author), MRDA, El Segundo, CA 90245 USA. NR 28 TC 52 Z9 55 U1 0 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0733-8724 J9 J LIGHTWAVE TECHNOL JI J. Lightwave Technol. PD DEC PY 2000 VL 18 IS 12 BP 1685 EP 1696 DI 10.1109/50.908693 PG 12 WC Engineering, Electrical & Electronic; Optics; Telecommunications SC Engineering; Optics; Telecommunications GA 410JZ UT WOS:000167438000009 ER PT J AU Montfrooij, W Svensson, EC AF Montfrooij, W Svensson, EC TI Superfluid He-4: Just a very cold liquid? SO JOURNAL OF LOW TEMPERATURE PHYSICS LA English DT Article; Proceedings Paper CT International Symposium on Quantum Fluids and Solids (QFS 2000) CY JUN 06-11, 2000 CL MINNEAPOLIS, MN SP Int Union Pure & Appl Phys, Natl Aeronaut & Space Administrat, Jet Propuls Lab, Univ Minnesota, Theoret Phys Inst, Minnesota Supercomp Inst, Digital Simulat & Adv Computat, Natl Sci Fdn, Div Mat Res, Univ Minnesota, Sch Phys & Astronomy, Univ Minnesota, Inst Technol, Univ Minnesota, Off Vice President Res Dean Grad Sch, Univ Minnesota, Off Provost & Execut Vice President, Andeen Hagerling Inc, Keithley Instrument Inc, Lakeshore Cryotron Inc, Oxford Instruments Inc ID ROTON EXCITATIONS; T-LAMBDA; DISAPPEARANCE; PROPAGATION; DEPENDENCE; CONDENSATE; PHONON AB We present a unified description of the dynamic response of superfluid He-4 using perturbation theory. We show that the characteristic features of the He-4 inelastic neutron scattering spectra at T similar to 1 K can be fully described by considering only density fluctuations. We also discuss how the response changes when the temperature is raised through the superfluid phase to the normal-fluid phase, and we argue that these changes principally reflect the behavior expected because of the Bose statistics obeyed by all the He-4 atoms rather than being effects of the depletion of the Bose condensate. C1 Oak Ridge Natl Lab, Div Solid State, Oak Ridge, TN 37831 USA. Natl Res Council Canada, Chalk River Labs, Chalk River, ON KOJ 1JO, Canada. RP Montfrooij, W (reprint author), Oak Ridge Natl Lab, Div Solid State, Oak Ridge, TN 37831 USA. EM Eric.Svensson@nrc.ca NR 25 TC 3 Z9 3 U1 1 U2 3 PU SPRINGER/PLENUM PUBLISHERS PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 0022-2291 EI 1573-7357 J9 J LOW TEMP PHYS JI J. Low Temp. Phys. PD DEC PY 2000 VL 121 IS 5-6 BP 293 EP 302 DI 10.1023/A:1017568722896 PG 10 WC Physics, Applied; Physics, Condensed Matter SC Physics GA 403FF UT WOS:000167031400009 ER PT J AU Cooke, DW Bennett, BL McClellan, KJ Roper, JM Whittaker, MT AF Cooke, DW Bennett, BL McClellan, KJ Roper, JM Whittaker, MT TI Similarities in glow peak positions and kinetics parameters of oxyorthosilicates: evidence for unique intrinsic trapping sites SO JOURNAL OF LUMINESCENCE LA English DT Article DE thermally stimulated luminescence; defects; oxyorthosilicates ID CZOCHRALSKI GROWTH; RARE-EARTH; SCINTILLATORS; CRYSTALS AB Thermally stimulated luminescence measurements on cerium-doped M2SiO5 (M = Lu, Y, Yb, Er) and undoped Lu2SiO5, each possessing monoclinic C2/c crystal symmetry, reveal common glow peaks with the principal one occurring near 375 K. In contrast, cerium-doped Gd2SiO5, characterized by the monoclinic P2(1)/c structure, exhibits a different glow curve with the principal peak occurring near 425 K. Although undoped Lu2SiO5 Shares the characteristic Ce-doped M2SiO5 glow curve, emission spectra data show that it emits weak line-emission, whereas the cerium-doped materials are characterized by the intense Ce3+ band spectrum. This suggests a common and unique trapping site whose formation does not require the presence of cerium. Application of peak-shape glow curve analysis shows that the characteristic peak near 375 K in each sample obeys first-order kinetics with thermal activation energy approx. 1 eV and frequency factor similar to 10(14)s(-1) Based on these results, we suggest that the characteristic glow peak is intrinsic and independent of cerium doping. This unique defect is common to the C2/c-structured oxyorthosilicates and is related to the host metal-ion-ligand configuration. (C) 2001 Elsevier Science B.V. All rights reserved. C1 Univ Calif Los Alamos Natl Lab, Mat Sci & Tech Div, Los Alamos, NM 87545 USA. RP Cooke, DW (reprint author), Univ Calif Los Alamos Natl Lab, Mat Sci & Tech Div, MST-8,MS E546, Los Alamos, NM 87545 USA. NR 18 TC 8 Z9 8 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-2313 J9 J LUMIN JI J. Lumines. PD DEC PY 2000 VL 92 IS 1-2 BP 83 EP 89 DI 10.1016/S0022-2313(00)00235-0 PG 7 WC Optics SC Optics GA 389KB UT WOS:000166236200010 ER PT J AU Carlson, JW AF Carlson, JW TI Nonlinear phase adjustment of selective excitation pulses SO JOURNAL OF MAGNETIC RESONANCE LA English DT Article DE selective excitation; RF waveforms; Bloch equations AB (1)A continuous transformation of an RF waveform with a modified Korteweg-de Vries equation or generalization can be used to adjust the phase behavior of a selective excitation pulse while preserving the magnitude behavior of the spin response. This transformation has applications in removing or adding to the nonlinear phase properties of a selected region. (C) 2000 Academic Press. C1 Toshiba Amer MRI Inc, Radiol Imaging Lab, S San Francisco, CA 94080 USA. RP Carlson, JW (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, 1 Cyclotron Rd,MS 64-121, Berkeley, CA 94720 USA. NR 6 TC 2 Z9 4 U1 0 U2 1 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 DEC PY 2000 VL 147 IS 2 BP 210 EP 216 DI 10.1006/jmre.2000.2201 PG 7 WC Biochemical Research Methods; Physics, Atomic, Molecular & Chemical; Spectroscopy SC Biochemistry & Molecular Biology; Physics; Spectroscopy GA 383XH UT WOS:000165909600005 PM 11097811 ER PT J AU Pruski, M Wiench, JW Amoureux, JP AF Pruski, M Wiench, JW Amoureux, JP TI On the conversion of triple- to single-quantum coherences in MQMAS NMR SO JOURNAL OF MAGNETIC RESONANCE LA English DT Article DE quadrupole nuclei; multiple quantum MAS NMR; efficiency of conversion ID ANGLE-SPINNING NMR; INTEGER QUADRUPOLAR NUCLEI; MAS-NMR; MAGNETIC-RESONANCE; SPECTROSCOPY; SENSITIVITY; SOLIDS; SYSTEMS; GLASSES; PULSES AB A systematic experimental and numerical evaluation of several basic approaches to multiple-quantum magic angle spinning (MQMAS) NMR is presented for spin-3/2 nuclei. The approaches use identical MQ excitation, via a single RF pulse of high power, and three types of methods for conversion to observable coherence: (a) nutation by strong continuous wave pulse; (b) rotation-induced adiabatic coherence transfer (RIACT), and (c) fast amplitude modulation (FAM-1). The optimization strategies and maximum achievable MQMAS efficiencies of Rb-87 in RbNO3 and LiRbSO4 are investigated using several coherence transfer schemes under a wide range of experimental parameters. These parameters include the strength of the RF magnetic field nu (RF), the sample rotation speed nu (R), the length of the conversion period, and the modulation frequency in FAM-1. The data provide new insights into the spin dynamics involved in these techniques and the experimental guidelines for achieving the best sensitivity. The RF requirements for maximum efficiency of conversion depend on the method to be used. In general, FAM-1 performs better than the nutation and RIACT methods in terms of efficiency and off-resonance behavior, especially when nu (RF) is small compared to the quadrupole frequency nu (Q). The experiments performed using nutation, RIACT, and FAM-1 methods yield similar resolution in the isotropic dimension, regardless of nu (RF). (C) 2000 Academic Press. C1 Iowa State Univ Sci & Technol, Ames Lab, Ames, IA 50011 USA. Univ Lille 1, F-59655 Villeneuve Dascq, France. RP Pruski, M (reprint author), Iowa State Univ Sci & Technol, Ames Lab, 230 Spedding Hall, Ames, IA 50011 USA. NR 39 TC 12 Z9 12 U1 1 U2 10 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 DEC PY 2000 VL 147 IS 2 BP 286 EP 295 DI 10.1006/jmre.2000.2190 PG 10 WC Biochemical Research Methods; Physics, Atomic, Molecular & Chemical; Spectroscopy SC Biochemistry & Molecular Biology; Physics; Spectroscopy GA 383XH UT WOS:000165909600014 PM 11097820 ER PT J AU Wind, RA Minard, KR Holtom, GR Majors, PD Ackerman, EJ Colson, SD Cory, DG Daly, DS Ellis, PD Metting, NF Parkinson, CI Price, JM Tang, XW AF Wind, RA Minard, KR Holtom, GR Majors, PD Ackerman, EJ Colson, SD Cory, DG Daly, DS Ellis, PD Metting, NF Parkinson, CI Price, JM Tang, XW TI An integrated confocal and magnetic resonance microscope for cellular research SO JOURNAL OF MAGNETIC RESONANCE LA English DT Article DE magnetic resonance microscopy; confocal scanning; fluorescent microscopy; integrated microscopy; cellular research; Xenopus laevis oocytes ID XENOPUS-LAEVIS OOCYTES; HIGH-RESOLUTION; TRANSFORMED-CELLS; NMR MICROSCOPY; CANCER-CELLS; SPECTROSCOPY; MRS; TUMORS; WATER; GRADIENT AB Complementary data acquired with different microscopy techniques provide a basis for establishing a more comprehensive understanding of health and disease at a cellular level, particularly when data acquired with different methodologies can be correlated in both time and space. In this Communication, a brief description of a novel instrument capable of simultaneously performing confocal optical and magnetic resonance microscopy is presented, and the first combined images of live Xenopus laevis oocytes are shown. Also, the potential benefits of combined microscopy are discussed, and it is shown that the a priori knowledge of the high-resolution optical images can be used to enhance the boundary resolution and contrast of the MR images. (C) 2000 Academic Press. C1 Pacific NW Natl Lab, Richland, WA 99352 USA. MIT, Dept Nucl Engn, Cambridge, MA 02139 USA. RP Wind, RA (reprint author), Pacific NW Natl Lab, POB 999,MS K8-98, Richland, WA 99352 USA. NR 30 TC 29 Z9 29 U1 0 U2 1 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 DEC PY 2000 VL 147 IS 2 BP 371 EP 377 DI 10.1006/jmre.2000.2212 PG 7 WC Biochemical Research Methods; Physics, Atomic, Molecular & Chemical; Spectroscopy SC Biochemistry & Molecular Biology; Physics; Spectroscopy GA 383XH UT WOS:000165909600022 PM 11097828 ER PT J AU Ernst, T Itti, E Itti, L Chang, L AF Ernst, T Itti, E Itti, L Chang, L TI Changes in cerebral metabolism are detected prior to perfusion changes in early HIV-CMC: A coregistered H-1 MRS and SPECT study SO JOURNAL OF MAGNETIC RESONANCE IMAGING LA English DT Article DE HIV; brain; dementia; SPECT; magnetic resonance spectroscopy ID AIDS DEMENTIA COMPLEX; EMISSION COMPUTED-TOMOGRAPHY; MAGNETIC-RESONANCE SPECTROSCOPY; IMMUNODEFICIENCY-SYNDROME DEMENTIA; ACTIVE ANTIRETROVIRAL THERAPY; VIRUS-ASSOCIATED DEMENTIA; COGNITIVE MOTOR COMPLEX; BLOOD-FLOW; ABSOLUTE QUANTITATION; PROTON SPECTROSCOPY AB Human immunodeficiency virus-cognitive motor complex (HIV-CMC), a common complication of the acquired Immunodeficiency syndrome (AIDS), is characterized by progressive cognitive impairment and motor dysfunction. Functional imaging methods, such as single-photon emission computed tomography (SPELT) and proton magnetic resonance spectroscopy (H-1-MRS), have been applied to assess the severity of brain injury. However, it is unclear which of these two methods is more sensitive in detecting brain abnormalities in patients with early HIV-CMC. Twenty-four HIV-CMC patients were compared with 34 healthy subjects; each had quantitative SPELT ((133)Xenon-calibrated Tc-99m-HMPAO) and quantitative 1H-MRS. Both modalities were co-registered in order to assess regional cerebral blood flow (rCBF) and metabolite concentrations within the same voxel of interest in four brain regions (midfrontal and midparietal gray matter, temporoparietal white matter, and basal ganglia). On SPELT, only the temporoparietal white matter showed a trend for decreased rCBF in HIV-CMC patients (-13%, P = 0.06). On MRS, HIV-CMC patients showed significantly reduced creatine concentration in the basal ganglia (-8%, P = 0.008), as well as Increased myoinositol concentrations in the basal ganglia (+25%, P = 0.01) and the temporoparietal white matter (+18%, P = 0.08). There was no significant correlation between SPELT and MRS variables in the patients in any region. H-1 MRS showed abnormal neurochemistry in the basal ganglia, whereas rCBF on SPELT was normal in the same region. This finding suggests that metabolite concentrations on H-1 MRS are better surrogate markers than rCBF measurements with SPELT for the evaluation of brain injury in early HIV-CMC. (C) 2000 Wiley-Liss, Inc. C1 Harbor UCLA Med Ctr, Dept Radiol, Torrance, CA 90502 USA. RP Ernst, T (reprint author), Brookhaven Natl Lab, Dept Med, POB 5000, Upton, NY 11973 USA. FU NCRR NIH HHS [MO1 RR00425]; NIDA NIH HHS [DA00280] NR 62 TC 31 Z9 35 U1 0 U2 2 PU JOHN WILEY & SONS INC PI NEW YORK PA 605 THIRD AVE, NEW YORK, NY 10158-0012 USA SN 1053-1807 J9 J MAGN RESON IMAGING JI J. Magn. Reson. Imaging PD DEC PY 2000 VL 12 IS 6 BP 859 EP 865 DI 10.1002/1522-2586(200012)12:6<859::AID-JMRI8>3.0.CO;2-T PG 7 WC Radiology, Nuclear Medicine & Medical Imaging SC Radiology, Nuclear Medicine & Medical Imaging GA 477QK UT WOS:000171295600008 PM 11105023 ER PT J AU Gresham, GL Groenewold, GS Olson, JE AF Gresham, GL Groenewold, GS Olson, JE TI Identification of the nitrogen-based blister agents bis(2-chloroethyl)methylamine (HN-2) and tris(2-chloroethyl)amine (HN-3) and their hydrolysis products on soil using ion trap secondary ion mass spectrometry SO JOURNAL OF MASS SPECTROMETRY LA English DT Article DE chemical weapons agents; secondary ion mass spectrometry; HN-3; HN-2; vesicants; surface analysis ID CHEMICAL WARFARE AGENTS; STATIC SIMS; DEGRADATION PRODUCTS; TRIBUTYL-PHOSPHATE; IONIZATION; SURFACES; CHROMATOGRAPHY; SULFIDE; NITRATE; REO4 AB The nitrogen blister agents HN-2 (bis(2-chforoethyl)methylemine) and HN-3 (tris(2-chloroethyl)amine) were directly analyzed on the surface of soil samples using ion trap secondary ion mass spectrometry (SIMS), In the presence of water, HN-1 (bis(2-choroethyl)ethylamine), HN-2 and HN-3 undergo hydrolysis to form N-ethyldiethanolamine, N-methyldiethanolamine and triethanolamine (TEA), respectively; these compounds can be readily detected as adsorbed species on soil particles, When soil samples spiked with HN-3 in alcohol were analyzed, 2-alkoxyethylamine derivatives were observed on the sample surfaces, This result shows that nitrogen blister agents mill undergo condensation reactions with nucleophilic compounds and emphasizes the need for an analytical methodology capable of detecting a range of degradation and condensation products on environmental surfaces. The ability of ion trap SIMS to isolate and accumulate ions, and then perform tandem mass spectrometric analysis improves the detection of low-abundance surface contaminants and the selectivity of the technique. Utilizing these techniques, the limits of detection for HN-3 were studied as a function of surface coverage. It was found that HN-3 could be detected at a surface coverage of 0.01 monolayer, which corresponds to 20 ppm (mass/mass) for a soil having a surface area of 2.2 m(2) g(-1). TEA, the exhaustive hydrolysis product of HN-3, was detected at a surface coverage of 0.001 monolayer, which corresponds to 0.86 ppm. Copyright (C) 2000 John Whey & Sons, Ltd. C1 Idaho Natl Engn & Environm Lab, Idaho Falls, ID 83415 USA. RP Gresham, GL (reprint author), Idaho Natl Engn & Environm Lab, POB 1625, Idaho Falls, ID 83415 USA. NR 29 TC 21 Z9 22 U1 1 U2 7 PU JOHN WILEY & SONS LTD PI W SUSSEX PA BAFFINS LANE CHICHESTER, W SUSSEX PO19 1UD, ENGLAND SN 1076-5174 J9 J MASS SPECTROM JI J. Mass Spectrom. PD DEC PY 2000 VL 35 IS 12 BP 1460 EP 1469 DI 10.1002/1096-9888(200012)35:12<1460::AID-JMS82>3.3.CO;2-A PG 10 WC Biophysics; Chemistry, Organic; Spectroscopy SC Biophysics; Chemistry; Spectroscopy GA 391GQ UT WOS:000166348600012 PM 11180637 ER PT J AU Paranthaman, M Park, C Cui, X Goyal, A Lee, DF Martin, PM Chirayil, TG Verebelyi, DT Norton, DP Christen, DK Kroeger, DM AF Paranthaman, M Park, C Cui, X Goyal, A Lee, DF Martin, PM Chirayil, TG Verebelyi, DT Norton, DP Christen, DK Kroeger, DM TI YBa2Cu3O7-y-coated conductors with high engineering current density SO JOURNAL OF MATERIALS RESEARCH LA English DT Article ID THIN-FILMS; SUPERCONDUCTING TAPES; DEPOSITION; YBCO; GROWTH AB Short segments of YBa2Cu3O7-y (YBCO) coated conductors were fabricated on rolling-assisted biaxially textured substrates (RABiTS) with a layer sequence of CeO2/YSZINi using an ex situ BaF2 precursor process. Pulsed laser deposition (PLD) was used to deposit both YSZ and CeO2 layers. The YBCO films were grown using e-beam coevaporated Y-BaF2-Cu precursors followed by postannealing. An overall engineering current density, J(E), of 28,000 A/cm(2) and critical current, I-c, of 147 A/cm width at 77 K were achieved for a 1.6-mum-thick YBCO film. This result demonstrates the possibility of using both the ex situ BaF2 precursor approach and the RABiTS process for producing long lengths of high-J(E) coated conductors. C1 Oak Ridge Natl Lab, Div Chem & Analyt Sci, Oak Ridge, TN 37831 USA. Oak Ridge Natl Lab, Div Solid State, Oak Ridge, TN 37831 USA. Oak Ridge Natl Lab, Div Met & Ceram, Oak Ridge, TN 37831 USA. RP Paranthaman, M (reprint author), Oak Ridge Natl Lab, Div Chem & Analyt Sci, Oak Ridge, TN 37831 USA. RI Christen, David/A-9709-2008; Yoon, Sejin/F-7637-2013; Paranthaman, Mariappan/N-3866-2015 OI Paranthaman, Mariappan/0000-0003-3009-8531 NR 19 TC 61 Z9 61 U1 1 U2 3 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 DEC PY 2000 VL 15 IS 12 BP 2647 EP 2652 DI 10.1557/JMR.2000.0379 PG 6 WC Materials Science, Multidisciplinary SC Materials Science GA 381CZ UT WOS:000165745900012 ER PT J AU Dogan, CP Hawk, JA AF Dogan, CP Hawk, JA TI Influence of whisker toughening and microstructure on the wear behavior of Si3N4- and Al2O3-matrix composites reinforced with SiC SO JOURNAL OF MATERIALS SCIENCE LA English DT Article ID ABRASIVE WEAR; SILICON-NITRIDE; FRACTURE-TOUGHNESS; MATRIX COMPOSITES; CERAMIC MATERIALS; ALUMINUM-OXIDE; GRAIN-SIZE; CARBIDE; INDENTATION; DEFORMATION AB A comparative study of the influence of randomly-oriented SiC whiskers on the abrasive wear behavior of several commercially-produced Si3N4- and Al2O3-based ceramics suggested that the residual stress states present within the materials can be important in predicting their wear resistance. The addition of SiC whiskers to the Si3N4 matrix created residual tensile stresses at the whisker-matrix interfaces which led to enhanced bulk fracture toughness, but which degraded the fracture toughness at the microstructural level, and thus the abrasive wear resistance, by promoting easier whisker debonding and removal by the abrasive particles. The addition of SiC whiskers to an alumina matrix, on the other hand, led to the creation of residual compressive stresses at whisker-matrix interfaces, producing a locally tougher interface that was more able to withstand the rigors of the abrasive wear environment. These results indicate that in brittle materials, improved bulk mechanical properties do not always pop pop directly to improved performance in a tribological environment. (C) 2000 Kluwer Academic Publishers. C1 US DOE, Albany Res Ctr, Albany, OR 97321 USA. RP Dogan, CP (reprint author), US DOE, Albany Res Ctr, Albany, OR 97321 USA. NR 53 TC 5 Z9 5 U1 1 U2 7 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0022-2461 J9 J MATER SCI JI J. Mater. Sci. PD DEC 1 PY 2000 VL 35 IS 23 BP 5793 EP 5807 DI 10.1023/A:1026721418251 PG 15 WC Materials Science, Multidisciplinary SC Materials Science GA 390KK UT WOS:000166294100001 ER PT J AU Li, H Li, L Vienna, JD Qian, M Wang, Z Darab, JG Peeler, DK AF Li, H Li, L Vienna, JD Qian, M Wang, Z Darab, JG Peeler, DK TI Neodymium(III) in alumino-borosilicate glasses SO JOURNAL OF NON-CRYSTALLINE SOLIDS LA English DT Article ID TERNARY-SYSTEM NA2O-B2O3-SIO2; NUCLEAR-MAGNETIC-RESONANCE; SODIUM-BORATE GLASSES; SILICATE-GLASSES; IONS; SPECTROSCOPY; RAMAN; NMR; DEPENDENCE; PARAMETERS AB Optical spectroscopy measurements were performed on Al2O3-B2O3-SiO2 glasses containing 7-25 mol% Nd2O3 (soluble). The local chemical environment of Nd(III) in glass was systematically studied as a function of the Nd2O3 concentration using Judd-Ofelt (J-O) optical oscillator parameters, Omega (2) and Omega (6), that are related to the ligand field symmetry (LFS) and the degree of bond covalency (BC), respectively. Two transition points (TPs), in terms of Omega (lambda) versus Nd2O3 concentration, were found for Omega (2) that is sensitive to LFS and Omega (6) that is sensitive to the degree of BC. The first TP is defined by Nd:3(B + Al) and the second by Nd:3(B + Al + Si). Below the first TP, Omega (2) and Omega (6) were nearly independent of Nd concentration. Between the first and the second TP, Omega (2) and Omega (6) increased and then decreased above the second TP. After reviewing literature data on rare earths (REs) in Na2O-B2O3, Na2O-SiO2, Na2O-B2O3-SiO2, and Al2O3-B2O3 systems, we proposed that up to the first TP, Nd preferentially dissolves in a borate-rich environment composed of two trigonal boron, B-III, and one tetrahedral boron, B-IV, where Al-IV substitutes for B-IV. Further increases in Nd2O3 concentrations result in excess Nd cations, [Nd-3(B + Al)], partitioning to a silicate-rich environment, possibly in a form of Nd-Q(3), and above the second TP, Nd-Q(2) could form at the expense of Nd-Q(3) (Q(n) is the number of bridging oxygens per Si tetrahedron), whereas the concentration of Nd cations in the borate sites is expected to be unchanged. Crystallization of Nd silicate above its solubility, 25-30 mol% Nd2O3, indirectly supports the proposed Nd dissolution mechanisms. The dissolution of rare earth elements in alumino-borosilicate glasses may be best described in terms of their partitioning to these structure groups. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Pacific NW Natl Lab, Richland, WA USA. Savannah River Tech Ctr, Aiken, SC USA. RP Li, H (reprint author), PPG Ind Inc, Glass Technol Ctr, Fundamental Sci Fiber Glass Sci & Technol, POB 2844, Pittsburgh, PA 15230 USA. RI Wang, Zheming/E-8244-2010 OI Wang, Zheming/0000-0002-1986-4357 NR 50 TC 42 Z9 42 U1 3 U2 27 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3093 J9 J NON-CRYST SOLIDS JI J. Non-Cryst. Solids PD DEC PY 2000 VL 278 IS 1-3 BP 35 EP 57 DI 10.1016/S0022-3093(00)00327-6 PG 23 WC Materials Science, Ceramics; Materials Science, Multidisciplinary SC Materials Science GA 388JR UT WOS:000166177800006 ER PT J AU Petri, MC Wei, TYC Kupperman, DS Reifman, J Morman, JA AF Petri, MC Wei, TYC Kupperman, DS Reifman, J Morman, JA TI Eddy current signal deconvolution technique for the improvement of steam generator tubing burst pressure predictions SO JOURNAL OF NONDESTRUCTIVE EVALUATION LA English DT Article DE steam generator tubing; eddy currents; signal processing; artificial neural networks; burst pressure ID NEURAL NETWORKS; EXPERT-SYSTEM; INSPECTION; TUBES; RECOGNITION; FRANCE; NDT AB Eddy current techniques are extremely sensitive to the presence of axial cracks in nuclear power plant steam generator tube walls, but they are equally sensitive to the presence of dents, fretting, support structures, corrosion products, and other artifacts. Eddy current signal interpretation is further complicated by cracking geometries more complex than a single axial crack. Although there has been limited success in classifying and sizing defects through artificial neural networks, the ability to predict tubing integrity has, so far, eluded modelers. In large part, this lack of success stems from an inability to distinguish crack signals from those arising from artifacts. We present here a new signal processing technique that deconvolves raw eddy current voltage signals into separate signal contributions from different sources, which allows signals associated with a dominant crack to be identified. The signal deconvolution technique, combined with artificial neural network modeling, significantly improves the prediction of tube burst pressure from bobbin-coil eddy current measurements of steam generator tubing. C1 Argonne Natl Lab, Argonne, IL 60439 USA. RP Petri, MC (reprint author), Argonne Natl Lab, 9700 S Cass Ave, Argonne, IL 60439 USA. NR 45 TC 2 Z9 2 U1 1 U2 3 PU KLUWER ACADEMIC/PLENUM PUBL PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 0195-9298 J9 J NONDESTRUCT EVAL JI J. Nondestruct. Eval. PD DEC PY 2000 VL 19 IS 4 BP 149 EP 164 DI 10.1023/A:1010712214335 PG 16 WC Materials Science, Characterization & Testing SC Materials Science GA 539XU UT WOS:000174898800004 ER PT J AU Taylor, NP Forty, CBA Petti, DA McCarthy, KA AF Taylor, NP Forty, CBA Petti, DA McCarthy, KA TI The impact of materials selection on long-term activation in fusion power plants SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT 9th International Conference on Fusion Reactor Materials (ICFRM-9) CY OCT 10-15, 1999 CL COLORADO SPRINGS, COLORADO SP US DOE, Off Fus Energy Sci, Argoone Natl Lab, Oak Ridge Natl Lab, Pacific NW Natl Lab, Univ Calif Santa Barbara, Amer Nucl Soc, Min Met & Mat Soc ID WASTE MANAGEMENT AB Neutron-induced transmutation of materials in a D-T fusion power plant will give rise to the potential for long-term activation. To ensure that the attractive safety and environmental characteristics of fusion power are not degraded, careful design choices are necessary. An aim of optimising power plant design must be to minimise both the level of activation and the total volume of active material that might ultimately be categorised as waste requiring disposal. Materials selection is central to this optimisation. In this paper we assess the influence of materials choices for a power plant on the waste volume and the potential to clear (i.e, remove from regulatory control) and recycle material. Although the use of low activation materials in regions of high neutron flux is an important part of the strategy to minimise the level of activation, different choices may result from a strategy aimed at minimising the volume of active waste. (C) 2000 UKAEA. Published by Elsevier Science B.V. All rights reserved. C1 UKAEA Euratom Fus Assoc, Theory & Modelling Dept, Culham Sci Ctr, Abingdon OX14 3DB, Oxon, England. Idaho Natl Engn & Environm Lab, Fus Safety Program, Idaho Falls, ID 83415 USA. RP Taylor, NP (reprint author), UKAEA Euratom Fus Assoc, Theory & Modelling Dept, Culham Sci Ctr, Abingdon OX14 3DB, Oxon, England. NR 25 TC 16 Z9 22 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 DEC PY 2000 VL 283 BP 28 EP 34 DI 10.1016/S0022-3115(00)00101-X PN A PG 7 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA 383HT UT WOS:000165877600005 ER PT J AU Scaffidi-Argentina, F Longhurst, GR Shestakov, V Kawamura, H AF Scaffidi-Argentina, F Longhurst, GR Shestakov, V Kawamura, H TI The status of beryllium technology for fusion SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT 9th International Conference on Fusion Reactor Materials (ICFRM-9) CY OCT 10-15, 1999 CL COLORADO SPRINGS, COLORADO SP US DOE, Off Fus Energy Sci, Argoone Natl Lab, Oak Ridge Natl Lab, Pacific NW Natl Lab, Univ Calif Santa Barbara, Amer Nucl Soc, Min Met & Mat Soc ID TRITIUM; LIMITER; SALT AB Beryllium was used for a number of years in the Joint European Torus (JET), and it is planned to be used extensively on the lower heat-flux surfaces of the reduced technical objective/reduced cost international thermonuclear experimental reactor (RTO/RC ITER). It has been included in Various forms in a number of tritium breeding blanket designs. There are technical advantages but also a number of safety issues associated with the use of beryllium. Research in a variety of technical areas in recent years has revealed interesting issues concerning the use of beryllium in fusion. Progress in this research has been presented at a series of International Workshops on Beryllium Technology for Fusion. The most recent workshop was held in Karlsruhe, Germany on 15-17 September 1999. In this paper, a summary of findings presented there and their implications for the use of beryllium in the development of fusion reactors are presented. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Lockheed Martin Idaho Techn Co, Idaho Natl Engn & Environm Lab, Idaho Falls, ID 83415 USA. Forschungszentrum Karlsruhe, IKET, D-76021 Karlsruhe, Germany. Sci Tech Ctr Controlled Thermonucl Fus, Almaty 480012, Kazakhstan. Japan Atom Energy Res Inst, Ibaraki, Osaka, Japan. RP Longhurst, GR (reprint author), Lockheed Martin Idaho Techn Co, Idaho Natl Engn & Environm Lab, POB 1625, Idaho Falls, ID 83415 USA. NR 36 TC 16 Z9 17 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3115 J9 J NUCL MATER JI J. Nucl. Mater. PD DEC PY 2000 VL 283 BP 43 EP 51 DI 10.1016/S0022-3115(00)00219-1 PN A PG 9 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA 383HT UT WOS:000165877600007 ER PT J AU van der Schaaf, B Gelles, DS Jitsukawa, S Kimura, A Klueh, RL Moslang, A Odette, GR AF van der Schaaf, B Gelles, DS Jitsukawa, S Kimura, A Klueh, RL Moslang, A Odette, GR TI Progress and critical issues of reduced activation ferritic/martensitic steel development SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT 9th International Conference on Fusion Reactor Materials (ICFRM-9) CY OCT 10-15, 1999 CL COLORADO SPRINGS, COLORADO SP US DOE, Off Fus Energy Sci, Argoone Natl Lab, Oak Ridge Natl Lab, Pacific NW Natl Lab, Univ Calif Santa Barbara, Amer Nucl Soc, Min Met & Mat Soc AB The inherent properties of reduced activation ferritic/martensitic (RAFM) steels include reduced swelling and high recycling potential, which make them likely candidates for application in commercial fusion power plants. The International Energy Agency (IEA) agreement has been an effective framework for international co-operation in developing RAFM steers. The progress and critical issues observed in this co-operation are reported. The production of RAFM steels on an industrial scale has been demonstrated. Various methods of fusion welding and solid hot isostatic pressing (HIP) are feasible for joining the steels. Manufacturing of complex shapes with the powder HIP method works well for RAFM steers. Major critical issues addressed concern the effects of simultaneous introduction of helium and displacement damage. The availability of a 14 MeV neutron source is identified as an essential tool to determine this effect. Finally, the potential of oxide dispersion strengthening to increase the operating temperature of RAFM steels is considered as an issue that has to be resolved to enlarge the application temperature window of RAFM steels. (C) 2000 Elsevier Science B.V. All rights reserved. C1 NRG, NL-1755 ZG Petten, Netherlands. Pacific NW Natl Lab, Richland, WA 99352 USA. Japan Atom Energy Res Inst, Tokai, Ibaraki 31911, Japan. Kyoto Univ, IAE, Kyoto 6110011, Japan. Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. FZK, IMF, Karlsruhe, Germany. Univ Calif Santa Barbara, Santa Barbara, CA 93106 USA. RP van der Schaaf, B (reprint author), NRG, POB 25,Westerduinweg 3, NL-1755 ZG Petten, Netherlands. NR 22 TC 117 Z9 117 U1 2 U2 35 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 DEC PY 2000 VL 283 BP 52 EP 59 DI 10.1016/S0022-3115(00)00220-8 PN A PG 8 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA 383HT UT WOS:000165877600008 ER PT J AU Kurtz, RJ Abe, K Chernov, VM Kazakov, VA Lucas, GE Matsui, H Muroga, T Odette, GR Smith, DL Zinkle, SJ AF Kurtz, RJ Abe, K Chernov, VM Kazakov, VA Lucas, GE Matsui, H Muroga, T Odette, GR Smith, DL Zinkle, SJ TI Critical issues and current status of vanadium alloys for fusion energy applications SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT 9th International Conference on Fusion Reactor Materials (ICFRM-9) CY OCT 10-15, 1999 CL COLORADO SPRINGS, COLORADO SP US DOE, Off Fus Energy Sci, Argoone Natl Lab, Oak Ridge Natl Lab, Pacific NW Natl Lab, Univ Calif Santa Barbara, Amer Nucl Soc, Min Met & Mat Soc ID CR-TI ALLOYS; PROGRESS AB Vanadium alloys are widely regarded as possessing desirable mechanical and physical properties for application as structural materials in fusion power systems. The bulk of the recent research on vanadium is focussed on ternaries containing 4-5% Cr and 4-10% Ti. The aim of this paper is to review significant results generated by the international research and development community on this alloy system and to highlight the critical issues that must be resolved before ahoy development can proceed to the next stage. Recent progress on understanding the physical metallurgy, fabrication and joining behavior, and compatibility with hydrogen and oxygen containing environments of unirradiated vanadium alloys is discussed. The effect of low-temperature neutron irradiation on mechanical properties and their relationship to the observed microstructure are briefly summarized. Current efforts to characterize the high-temperature mechanical properties, develop constitutive equations describing flow and fracture, and understand and mitigate the effects of non-metallic impurities on properties are presented. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Pacific NW Natl Lab, Richland, WA 99352 USA. Tohoku Univ, Dept Quantum Sci & Energy Engn, Sendai, Miyagi 9808577, Japan. AA Bochvar Inorgan Mat Res Inst, Moscow, Russia. Res Inst Atom Reactors, Dimitrovgrad, Russia. Univ Calif Santa Barbara, Santa Barbara, CA 93106 USA. Tohoku Univ, Mat Res Inst, Sendai, Miyagi 9808577, Japan. Natl Inst Fus Sci, Gifu 5095292, Japan. Argonne Natl Lab, Argonne, IL 60439 USA. Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Kurtz, RJ (reprint author), Pacific NW Natl Lab, POB 999, Richland, WA 99352 USA. RI Chernov, Vyacheslav/F-1470-2014; OI Zinkle, Steven/0000-0003-2890-6915 NR 65 TC 97 Z9 106 U1 0 U2 6 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3115 J9 J NUCL MATER JI J. Nucl. Mater. PD DEC PY 2000 VL 283 BP 70 EP 78 DI 10.1016/S0022-3115(00)00351-2 PN A PG 9 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA 383HT UT WOS:000165877600010 ER PT J AU Ehrlich, K Bloom, EE Kondo, T AF Ehrlich, K Bloom, EE Kondo, T TI International strategy for fusion materials development SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT 9th International Conference on Fusion Reactor Materials (ICFRM-9) CY OCT 10-15, 1999 CL COLORADO SPRINGS, COLORADO SP US DOE, Off Fus Energy Sci, Argoone Natl Lab, Oak Ridge Natl Lab, Pacific NW Natl Lab, Univ Calif Santa Barbara, Amer Nucl Soc, Min Met & Mat Soc AB In this paper, the results of an IEA-Workshop on Strategy and Planning of Fusion Materials Research and Development (R&D), held in October 1998 in Rise Denmark are summarised and further developed. Essential performance targets for materials to be used in first wall/breeding blanket components have been defined for the major materials groups under discussion: ferritic-martensitic steels, vanadium alloys and ceramic composites of the SiC/SiC-type. R&D strategies are proposed for their further development and qualification as reactor-relevant materials. The important role of existing irradiation facilities (mainly fission reactors) for materials testing within the next decade is described, and the limits for the transfer of results from such simulation experiments to fusion-relevant conditions are addressed. The importance of a fusion-relevant high-intensity neutron source for the development of structural as well as breeding and special purpose materials is elaborated and the reasons for the selection of an accelerator-driven D-Li-neutron source - the International Fusion Materials Irradiation Facility (IFMIF) - as an appropriate test bed are explained. Finally the necessity to execute the materials programme for fusion in close international collaboration, presently promoted by the International Energy Agency, IEA is emphasised. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Forschungszentrum Karlsruhe, Inst Mat Forsch 1, D-76021 Karlsruhe, Germany. Oak Ridge Natl Lab, Div Met & Ceram, Oak Ridge, TN USA. RP Ehrlich, K (reprint author), Forschungszentrum Karlsruhe, Inst Mat Forsch 1, Postfach 3640, D-76021 Karlsruhe, Germany. NR 23 TC 67 Z9 71 U1 1 U2 11 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 DEC PY 2000 VL 283 BP 79 EP 88 DI 10.1016/S0022-3115(00)00102-1 PN A PG 10 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA 383HT UT WOS:000165877600011 ER PT J AU Federici, G Coad, JP Haasz, AA Janeschitz, G Noda, N Philipps V Roth, J Skinner, CH Tivey, R Wu, CH AF Federici, G Coad, JP Haasz, AA Janeschitz, G Noda, N Philipps, V Roth, J Skinner, CH Tivey, R Wu, CH TI Critical plasma-wall interaction issues for plasma-facing materials and components in near-term fusion devices SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT 9th International Conference on Fusion Reactor Materials (ICFRM-9) CY OCT 10-15, 1999 CL COLORADO SPRINGS, CO SP US DOE, Off Fus Energy Sci, Argonne Natl Lab, Oak Ridge Natl Lab, Pacific NW Natl Lab, Univ Calif Santa Barbara, Amer Nucl Soc, Min Met & Mat Soc ID ALCATOR C-MOD; ASDEX UPGRADE; ITER DIVERTOR; DIII-D; TOKAMAK; RETENTION; EROSION; JET; EROSION/REDEPOSITION; TRANSPORT AB The increase in pulse duration and cumulative run-time, together with the increase of the plasma energy content, will represent the largest changes in operation conditions in future fusion devices such as the International Thermonuclear Experimental Reactor (ITER) compared to today's experimental facilities. These will give rise to important plasma-physics effects and plasma-material interactions (PMIs) which are only partially observed and accessible in present-day experiments and will open new design, operation and safety issues. For the first time in fusion research, erosion and its consequences over many pulses (e.g., co-deposition and dust) may determine the operational schedule of a fusion device, This paper identifies the most critical issues arising from PMIs which represent key elements in the selection of materials, the design, and the optimisation of plasma-facing components (PFCs) for the first-wall and divertor. Significant advances in the knowledge base have been made recently, as part of the R&D supporting the engineering design activities (EDA) of ITER, and some of the most relevant data are reviewed here together with areas where further R&D work is urgently needed. (C) 2000 Elsevier Science B.V. All rights reserved. C1 JWS Garching Coctr, ITER, D-85748 Garching, Germany. Jet Joint Undertaking, Abingdon OX14 3EA, Oxon, England. Univ Toronto, Inst Aerosp Studies, Toronto, ON M3H 5T6, Canada. Natl Inst Fus Sci, Toki 5095292, Japan. Forschungszentrum Julich, Inst Plasma Phys, D-52425 Julich, Germany. Max Planck Inst Plasma Phys, D-85748 Garching, Germany. Princeton Univ, Plasma Phys Lab, Princeton, NJ 08543 USA. EFDA, D-85748 Garching, Germany. RP Federici, G (reprint author), JWS Garching Coctr, ITER, Boltzmanstr 2, D-85748 Garching, Germany. EM federig@ipp.mpg.de NR 31 TC 25 Z9 26 U1 0 U2 6 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3115 J9 J NUCL MATER JI J. Nucl. Mater. PD DEC PY 2000 VL 283 BP 110 EP 119 DI 10.1016/S0022-3115(00)00158-6 PG 10 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA 383HT UT WOS:000165877600014 ER PT J AU Hasegawa, A Kohyama, A Jones, RH Snead, LL Riccardi, B Fenici, P AF Hasegawa, A Kohyama, A Jones, RH Snead, LL Riccardi, B Fenici, P TI Critical issues and current status of SiC/SiC composites for fusion SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT 9th International Conference on Fusion Reactor Materials (ICFRM-9) CY OCT 10-15, 1999 CL COLORADO SPRINGS, COLORADO SP US DOE, Off Fus Energy Sci, Argoone Natl Lab, Oak Ridge Natl Lab, Pacific NW Natl Lab, Univ Calif Santa Barbara, Amer Nucl Soc, Min Met & Mat Soc ID SILICON-CARBIDE; NEUTRON-IRRADIATION; SICF/SIC COMPOSITES; MULTILAYERED INTERPHASES; HELIUM IMPLANTATION; CERAMICS; FIBERS AB SiC fiber-reinforced SiC matrix composites (SiC/SiC) are being considered as a candidate structural material for fusion reactors because of their low induced radioactivity by 14 MeV neutron irradiation and high-temperature strength. Material development of SiC/SiC composites, including SiC fiber, matrix and interphase processing for fusion reactor applications, has been under investigation for several years. The purpose of this paper is to present an overview of current research in material development, properties and irradiation response of new SiC/SiC composites. Several technologically critical issues to be solved for fusion applications, such as irradiation resistance, thermal properties, environmental effects, hermeticity, joining technique and protective coating are also reviewed. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Tohoku Univ, Dept Quantum Sci & Energy Engn, Aoba Ku, Sendai, Miyagi 9808579, Japan. Kyoto Univ, Kyoto, Japan. Pacific NW Natl Lab, Richland, WA 99352 USA. JRC, Ispra, Italy. RP Hasegawa, A (reprint author), Tohoku Univ, Dept Quantum Sci & Energy Engn, Aoba Ku, Aramaki Aza Aoba 01, Sendai, Miyagi 9808579, Japan. NR 59 TC 131 Z9 137 U1 6 U2 46 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 DEC PY 2000 VL 283 BP 128 EP 137 DI 10.1016/S0022-3115(00)00374-3 PN A PG 10 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA 383HT UT WOS:000165877600016 ER PT J AU Barabash, V Federici, G Rodig, M Snead, LL Wu, CH AF Barabash, V Federici, G Rodig, M Snead, LL Wu, CH TI Neutron irradiation effects on plasma facing materials SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT 9th International Conference on Fusion Reactor Materials (ICFRM-9) CY OCT 10-15, 1999 CL COLORADO SPRINGS, COLORADO SP US DOE, Off Fus Energy Sci, Argoone Natl Lab, Oak Ridge Natl Lab, Pacific NW Natl Lab, Univ Calif Santa Barbara, Amer Nucl Soc, Min Met & Mat Soc ID CARBON-FIBER COMPOSITES; THERMAL-CONDUCTIVITY; ITER DIVERTOR; GRAPHITE; DAMAGE AB This paper reviews the effects of neutron irradiation on thermal and mechanical properties and bulk tritium retention of armour materials (beryllium, tungsten and carbon). For each material, the main properties affected by neutron irradiation are described and the specific tests of neutron irradiated armour materials under thermal shock and disruption conditions are summarized. Based on current knowledge, the expected thermal and structural performance of neutron irradiated armour materials in the ITER plasma facing components are analysed. (C) 2000 Elsevier Science B.V. All rights reserved. C1 ITER Joint Cent Team, D-85748 Garching, Germany. EURATOM Assoc, Forschungszentrum, D-52425 Julich, Germany. Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. EFDA, Close Support Unit, D-85748 Garching, Germany. RP Barabash, V (reprint author), ITER Joint Cent Team, Boltzmannstr 2, D-85748 Garching, Germany. NR 72 TC 54 Z9 55 U1 4 U2 25 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 DEC PY 2000 VL 283 BP 138 EP 146 DI 10.1016/S0022-3115(00)00203-8 PN A PG 9 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA 383HT UT WOS:000165877600017 ER PT J AU Dvoriashin, AM Porollo, SI Konobeev, YV Garner, FA AF Dvoriashin, AM Porollo, SI Konobeev, YV Garner, FA TI Influence of cold work to increase swelling of pure iron irradiated in the BR-10 reactor to similar to 6 and similar to 25 dpa at similar to 400 degrees C SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT 9th International Conference on Fusion Reactor Materials (ICFRM-9) CY OCT 10-15, 1999 CL COLORADO SPRINGS, COLORADO SP US DOE, Off Fus Energy Sci, Argoone Natl Lab, Oak Ridge Natl Lab, Pacific NW Natl Lab, Univ Calif Santa Barbara, Amer Nucl Soc, Min Met & Mat Soc ID ALLOYS AB Irradiation of pure iron in several starting conditions at 400 degreesC has been conducted in the BR-10 fast reactor. Contrary to expectations, cold working appears to significantly accelerate the onset of void swelling. When compared to a similar experiment conducted in this reactor at the same time, it appears that iron experiences a rather long transient duration before the onset of steady-state swelling. The transient appears to be shortened by both cold-working and lower atomic displacement rates. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Inst Phys & Power Engn, Obninsk, Russia. Pacific NW Natl Lab, Mat Resources Dept, Richland, WA 99352 USA. RP Garner, FA (reprint author), Inst Phys & Power Engn, Obninsk, Russia. NR 5 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 DEC PY 2000 VL 283 BP 157 EP 160 DI 10.1016/S0022-3115(00)00337-8 PN A PG 4 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA 383HT UT WOS:000165877600020 ER PT J AU Sencer, BH Garner, FA AF Sencer, BH Garner, FA TI Compositional and temperature dependence of void swelling in model Fe-Cr base alloys irradiated in the EBR-II fast reactor SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT 9th International Conference on Fusion Reactor Materials (ICFRM-9) CY OCT 10-15, 1999 CL COLORADO SPRINGS, COLORADO SP US DOE, Off Fus Energy Sci, Argoone Natl Lab, Oak Ridge Natl Lab, Pacific NW Natl Lab, Univ Calif Santa Barbara, Amer Nucl Soc, Min Met & Mat Soc ID SIMPLE FERRITIC ALLOYS; AUSTENITIC ALLOYS AB A series of annealed and aged Fe-xCr, Fe-12Cr-yC and Fe-12Cr-0.1C-zMo model alloys were irradiated in EBR-II at eight temperatures between 400 degreesC and 650 degreesC and dose levels ranging from 35 to 131 dpa. Swelling-induced density changes observed in the binary alloys generally peaked at mid-chromium levels, with the chromium and temperature dependence expressed primarily in the duration of the transient regime. The steady-state swelling rate at the lower irradiation temperatures was much higher than previous estimates, reaching similar to0.2%/dpa and possibly still climbing at higher neutron exposures. The dependence of swelling on molybdenum and carbon was more complex, depending on whether the temperature was relatively low or high. At temperatures of 482 degreesC and above, the effect of carbon additions was very pronounced with swelling of Fe-12Cr jumping dramatically from near zero at 0.002% C to 6-10% at 0.1% C. This indicates that the major determinant of the composition and temperature dependence probably lies in the duration of the nucleation-dominated transient regime of swelling and not primarily in the steady-state swelling rate as previously envisioned. This raises the possibility that significant swelling may occur earlier in fusion and spallation neutron spectra where high gas generation rates may assist void nucleation. (C) 2000 Elsevier Science B.V. All rights reserved. C1 New Mexico Tech, Socorro, NM 87801 USA. Pacific NW Natl Lab, Mat Resources Dept, Richland, WA 99352 USA. RP Sencer, BH (reprint author), New Mexico Tech, Socorro, NM 87801 USA. NR 16 TC 23 Z9 24 U1 0 U2 14 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 DEC PY 2000 VL 283 BP 164 EP 168 DI 10.1016/S0022-3115(00)00338-X PN A PG 5 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA 383HT UT WOS:000165877600022 ER PT J AU Porollo, SI Dvoriashin, AM Vorobjev, AN Konobeev, YV Krigan, VM Mironova, EG Budylkin, NI Garner, FA AF Porollo, SI Dvoriashin, AM Vorobjev, AN Konobeev, YV Krigan, VM Mironova, EG Budylkin, NI Garner, FA TI Void swelling and irradiation creep of two high-nickel steels after irradiation at 400-410 degrees C to 84-91 dpa in the BN-350 fast reactor SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT 9th International Conference on Fusion Reactor Materials (ICFRM-9) CY OCT 10-15, 1999 CL COLORADO SPRINGS, COLORADO SP US DOE, Off Fus Energy Sci, Argoone Natl Lab, Oak Ridge Natl Lab, Pacific NW Natl Lab, Univ Calif Santa Barbara, Amer Nucl Soc, Min Met & Mat Soc AB The relationship between irradiation creep and void swelling has been extensively studied for 300 series stainless steels with relatively low-nickel content. Similar studies on high-nickel alloys are not so common, however. An experiment conducted at similar to 400 degreesC and 84-91 dpa on two Russian high-nickel steels in the BN-350 fast reactor demonstrates that the form of the creep law and the creep-swelling relationship are not changed significantly at higher nickel levels. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Pacific NW Natl Lab, Mat Resources Dept, Richland, WA 99352 USA. Inst Phys & Power Engn, Obninsk, Russia. Bochvars Res Inst Nonorgan Mat, Moscow, Russia. RP Garner, FA (reprint author), Pacific NW Natl Lab, Mat Resources Dept, 902 Battelle Blvd,P8-15 Richland, Richland, WA 99352 USA. NR 11 TC 3 Z9 3 U1 1 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3115 J9 J NUCL MATER JI J. Nucl. Mater. PD DEC PY 2000 VL 283 BP 239 EP 243 DI 10.1016/S0022-3115(00)00342-1 PN A PG 5 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA 383HT UT WOS:000165877600037 ER PT J AU Miwa, Y Sawai, T Fukai, K Hoelzer, DT Hishinuma, A AF Miwa, Y Sawai, T Fukai, K Hoelzer, DT Hishinuma, A TI Microstructures in Ti-Al intermetallic compounds irradiated at 673 K in HFIR SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT 9th International Conference on Fusion Reactor Materials (ICFRM-9) CY OCT 10-15, 1999 CL COLORADO SPRINGS, COLORADO SP US DOE, Off Fus Energy Sci, Argoone Natl Lab, Oak Ridge Natl Lab, Pacific NW Natl Lab, Univ Calif Santa Barbara, Amer Nucl Soc, Min Met & Mat Soc ID ELECTRON; ALLOYS AB Four kinds of Ti-Al intermetallic compounds were made from powder metallurgical processing using mechanical alloying or plasma rotating electrode processing. One consisted of alpha (2)-Ti3Al single phase, and the others consisted of alpha (2)-Ti3Al and gamma -TiAl duplex phases. These intermetallic compounds were irradiated at 673 K to the fluence of 5.16x10(25) n/m(2) (E>1 MeV) in the high flux isotope reactor. After irradiation, transmission electron microscopy was carried out. Cavities were observed in both the alpha (2)-Ti3Al- and gamma -TiAl-phases. The nucleation behavior of cavities in the alpha (2)-Ti3Al- and gamma -TiAl-phases was influenced by chemical composition and fabrication processes. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Japan Atom Energy Res Inst, Dept Mat Sci & Engn, Tokai, Ibaraki 3191195, Japan. Oak Ridge Natl Lab, Div Met & Ceram, Oak Ridge, TN 37831 USA. RP Miwa, Y (reprint author), Japan Atom Energy Res Inst, Dept Mat Sci & Engn, Shirakata Shirane 2-4, Tokai, Ibaraki 3191195, Japan. RI Hoelzer, David/L-1558-2016 NR 13 TC 5 Z9 5 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3115 J9 J NUCL MATER JI J. Nucl. Mater. PD DEC PY 2000 VL 283 BP 273 EP 277 DI 10.1016/S0022-3115(00)00357-3 PN A PG 5 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA 383HT UT WOS:000165877600044 ER PT J AU Xu, Q Heinisch, HL Yoshiie, T AF Xu, Q Heinisch, HL Yoshiie, T TI Computer simulations of the effects of temperature change on defect accumulation in copper during neutron irradiation SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT 9th International Conference on Fusion Reactor Materials (ICFRM-9) CY OCT 10-15, 1999 CL COLORADO SPRINGS, COLORADO SP US DOE, Off Fus Energy Sci, Argoone Natl Lab, Oak Ridge Natl Lab, Pacific NW Natl Lab, Univ Calif Santa Barbara, Amer Nucl Soc, Min Met & Mat Soc ID CASCADES AB Kinetic Monte Carlo (kMC) computer simulations were used to study the effects of temperature change during low-dose 14-MeV fusion neutron irradiations on defect accumulation in copper. Instantaneous temperature changes from 300 to 473 K, from 300 to 673 K and from 373 to 573 K were simulated. All the high temperatures are above the Stage-V annealing temperature for copper, approximately 400 K. The total simulated dose was 0.01 dpa for all temperature-change simulations, at a dose rate of 10(-6) dpa/s. In general, the concentrations of both self-interstitial atom (SIA) clusters and vacancy clusters decrease when the temperature is changed from low to high. The relative decrease in concentration of defect clusters when the temperature is increased is determined by the level of accumulation of vacancy clusters in the initial low-temperature part of the irradiation as well as by the specific temperatures involved. If the vacancy clusters are small and their concentration is high, the decrease of cluster density is prominent when the temperature increases, and the higher the second temperature, the easier it is for defect clusters to dissolve. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Kyoto Univ, Inst Res Reactor, Kumatori, Osaka 5900494, Japan. Pacific NW Natl Lab, Richland, WA 99352 USA. RP Xu, Q (reprint author), Kyoto Univ, Inst Res Reactor, Kumatori, Osaka 5900494, Japan. NR 10 TC 7 Z9 7 U1 0 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3115 J9 J NUCL MATER JI J. Nucl. Mater. PD DEC PY 2000 VL 283 BP 297 EP 301 DI 10.1016/S0022-3115(00)00358-5 PN A PG 5 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA 383HT UT WOS:000165877600049 ER PT J AU Zinkle, SJ Singh, BN AF Zinkle, SJ Singh, BN TI Microstructure of Cu-Ni alloys neutron irradiated at 210 degrees C and 420 degrees C to 14 dpa SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT 9th International Conference on Fusion Reactor Materials (ICFRM-9) CY OCT 10-15, 1999 CL COLORADO SPRINGS, CO SP US DOE, Off Fus Energy Sci, Argonne Natl Lab, Oak Ridge Natl Lab, Pacific NW Natl Lab, Univ Calif Santa Barbara, Amer Nucl Soc, Min Met & Mat Soc ID POINT-DEFECT CLUSTERS; CASCADE DAMAGE CONDITIONS; COPPER-ALLOYS; RAPID NEUTRONS; VOID FORMATION; PURE COPPER; BCC METALS; EVOLUTION; ACCUMULATION; TRANSIENT AB Transmission electron microscope (TEM) disks of pure copper and copper containing 0.17-10% Ni were neutron irradiated at 210 degreesC and 420 degreesC in Hf-shielded capsules in the High Flux Isotopes Reactor to doses of 13.5 and 14.9 displacements per atom (dpa), respectively. Void swelling was not observed in any of the specimens irradiated at 210 degreesC. Instead, a high density of stacking fault tetrahedra (SFTs) and a moderate density of dislocation loops were observed. There was no evidence for defect cluster patterning (wall formation) in any of the specimens irradiated at 210 degreesC. The SFT density was independent of Ni content, whereas the loop density was highest in the alloy containing similar to2% Ni. Pronounced void swelling was observed in all of the specimens irradiated at 420 degreesC. A void denuded zone of similar to2 mum width was observed adjacent to grain boundaries. The void swelling in copper containing, similar to2% Ni showed a pronounced maximum in a 10-mum wide band adjacent to the grain boundary denuded zones. Matrix voids aligned along [1 1 0] directions were observed in Cu-10%Ni irradiated at 420 degreesC. The occurrence of the peak swelling zone and the partial ordering of voids are both consistent with the predictions of the recent production bias model which includes 1-D diffusional transport of clusters of self-interstitial atoms. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Oak Ridge Natl Lab, Div Met & Ceram, Oak Ridge, TN 37831 USA. Riso Natl Lab, Mat Res Dept, DK-4000 Roskilde, Denmark. 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 46 TC 29 Z9 29 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 DEC PY 2000 VL 283 BP 306 EP 312 DI 10.1016/S0022-3115(00)00359-7 PN A PG 7 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA 383HT UT WOS:000165877600051 ER PT J AU Katoh, Y Stoller, RE Kohyama, A Muroga, T AF Katoh, Y Stoller, RE Kohyama, A Muroga, T TI Simulating the influence of radiation temperature variations on microstructural evolution SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT 9th International Conference on Fusion Reactor Materials (ICFRM-9) CY OCT 10-15, 1999 CL COLORADO SPRINGS, COLORADO SP US DOE, Off Fus Energy Sci, Argoone Natl Lab, Oak Ridge Natl Lab, Pacific NW Natl Lab, Univ Calif Santa Barbara, Amer Nucl Soc, Min Met & Mat Soc ID REACTOR IRRADIATION; CASCADE DAMAGE; CLUSTERS; GROWTH AB The influence of temperature variations on microstructural evolution in austenitic stainless steels is discussed in order to help interpret the response of materials in the HFIR-RB-13J temperature variation experiment. A kinetic microstructural evolution model developed for irradiated austenitic stainless steels was modified to provide a fully dynamic calculation of point defect and point defect cluster concentrations. Using the modified model, microstructural evolution was predicted for simulated HFIR-RB-13J temperature Variation experiments and variations in material parameters were evaluated. The results indicate that repeated temperature excursion to 573 from 773 K always results in increased dislocation loop density and reduced cumulative defect flux within the calculated material parameter range, while excursions to 473 from 623 K may increase or decrease them depending on material parameters. The primary influence of temperature Variation could be explained by accumulation and release of matrix defects at the temperatures of interest. The applicability of the current model must be further studied by careful investigation of the results from the HFIR-13J and related experiments. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Kyoto Univ, Inst Adv Energy, Kyoto 6110011, Japan. Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. Natl Inst Fus Sci, Toki 5095292, Japan. RP Katoh, Y (reprint author), Kyoto Univ, Inst Adv Energy, Kyoto 6110011, Japan. RI Stoller, Roger/H-4454-2011; OI Katoh, Yutai/0000-0001-9494-5862 NR 19 TC 10 Z9 10 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3115 J9 J NUCL MATER JI J. Nucl. Mater. PD DEC PY 2000 VL 283 BP 313 EP 318 DI 10.1016/S0022-3115(00)00257-9 PN A PG 6 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA 383HT UT WOS:000165877600052 ER PT J AU Sencer, BH Bond, GM Garner, FA Hamilton, ML Oliver, BM Thomas, LE Maloy, SA Sommer, WF James, MR Ferguson, PD AF Sencer, BH Bond, GM Garner, FA Hamilton, ML Oliver, BM Thomas, LE Maloy, SA Sommer, WF James, MR Ferguson, PD TI Microstructural evolution of Alloy 718 at high helium and hydrogen generation rates during irradiation with 600-800 MeV protons SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT 9th International Conference on Fusion Reactor Materials (ICFRM-9) CY OCT 10-15, 1999 CL COLORADO SPRINGS, COLORADO SP US DOE, Off Fus Energy Sci, Argoone Natl Lab, Oak Ridge Natl Lab, Pacific NW Natl Lab, Univ Calif Santa Barbara, Amer Nucl Soc, Min Met & Mat Soc AB When precipitation hardened Ahoy 718 is irradiated with high-energy protons (600-800 MeV) and spallation neutrons at temperatures below similar to 60 degreesC, it quickly hardens and roses almost all uniform elongation. It later softens somewhat at higher exposures but does not regain any elongation. This behavior is explained in terms of the evolution of Frank loop formation, disordering and eventual dissolution of the gamma' and gamma " strengthening phases, and the steady accumulation of very large levels of helium and hydrogen. These gases must be dispersed on a very fine scare in the matrix since no cavities could be found. (C) 2000 Elsevier Science B.V. All rights reserved. C1 New Mexico Inst Min & Technol, Socorro, NM USA. Pacific NW Natl Lab, Mat Res Lab, Richland, WA 99352 USA. Los Alamos Natl Lab, Los Alamos, NM USA. RP Sencer, BH (reprint author), New Mexico Inst Min & Technol, Socorro, NM USA. RI Maloy, Stuart/A-8672-2009; OI Maloy, Stuart/0000-0001-8037-1319; Ferguson, Phillip/0000-0002-7661-4223 NR 10 TC 12 Z9 12 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 DEC PY 2000 VL 283 BP 324 EP 328 DI 10.1016/S0022-3115(00)00308-1 PN A PG 5 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA 383HT UT WOS:000165877600054 ER PT J AU Miwa, Y Wakai, E Shiba, K Hashimoto, N Robertson, JP Rowcliffe, AF Hishinuma, A AF Miwa, Y Wakai, E Shiba, K Hashimoto, N Robertson, JP Rowcliffe, AF Hishinuma, A TI Swelling of F82H irradiated at 673 K up to 51 dpa in HFIR SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT 9th International Conference on Fusion Reactor Materials (ICFRM-9) CY OCT 10-15, 1999 CL COLORADO SPRINGS, COLORADO SP US DOE, Off Fus Energy Sci, Argoone Natl Lab, Oak Ridge Natl Lab, Pacific NW Natl Lab, Univ Calif Santa Barbara, Amer Nucl Soc, Min Met & Mat Soc ID MARTENSITIC STEELS AB Reduced-activation ferritic/martensitic steel, F82H (8Cr-2W-0.2V-0.04Ta-0.1C), and variants doped with isotopically tailored boron were irradiated at 673 K up to 51 dpa in the high flux isotope reactor (HFIR). The concentrations of B-10 in these alloys were 4, 62, and 325 appm during HFIR irradiation which resulted in the production of 4, 62 and 325 appm He, respectively After irradiation, transmission electron microscopy (TEM) was carried out. The number density of cavities increased and the average diameter of cavities decreased with increasing amounts of B-10. The number density decreased and the average diameter increased with increasing displacement damage. Swelling increased as a function of displacement damage and He concentration. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Japan Atom Energy Res Inst, Dept Mat Sci, Tokai, Ibaraki 3191195, Japan. Oak Ridge Natl Lab, Div Met & Ceram, Oak Ridge, TN 37831 USA. RP Miwa, Y (reprint author), Japan Atom Energy Res Inst, Dept Mat Sci, Tokai, Ibaraki 3191195, Japan. RI HASHIMOTO, Naoyuki/D-6366-2012; Wakai, Eiichi/L-1099-2016 NR 20 TC 13 Z9 15 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 DEC PY 2000 VL 283 BP 334 EP 338 DI 10.1016/S0022-3115(00)00222-1 PN A PG 5 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA 383HT UT WOS:000165877600056 ER PT J AU Gelles, DS AF Gelles, DS TI Microstructural examination of V-(3-6%)Cr-(3-5%)Ti irradiated in the ATR-A1 experiment SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT 9th International Conference on Fusion Reactor Materials (ICFRM-9) CY OCT 10-15, 1999 CL COLORADO SPRINGS, COLORADO SP US DOE, Off Fus Energy Sci, Argoone Natl Lab, Oak Ridge Natl Lab, Pacific NW Natl Lab, Univ Calif Santa Barbara, Amer Nucl Soc, Min Met & Mat Soc AB Microstructural examination results are reported for four heats of V-(3-6%)Cr-(3-5%)Ti irradiated in the ATR-Al experiment to similar to4 dpa at 200 degreesC and 300 degreesC to provide an understanding of the microstructural evolution that may be associated with degradation of mechanical properties. Fine precipitates were observed in high density intermixed with small defect clusters for all conditions examined following the irradiation. The irradiation-induced precipitation does not appear to be affected by preirradiation heat treatment or composition. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Pacific NW Natl Lab, Richland, WA 99352 USA. RP Gelles, DS (reprint author), Pacific NW Natl Lab, MS P8-15,POB 999, Richland, WA 99352 USA. NR 11 TC 3 Z9 5 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 DEC PY 2000 VL 283 BP 344 EP 348 DI 10.1016/S0022-3115(00)00309-3 PN A PG 5 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA 383HT UT WOS:000165877600058 ER PT J AU Stoller, RE Zinkle, SJ AF Stoller, RE Zinkle, SJ TI On the relationship between uniaxial yield strength and resolved shear stress in polycrystalline materials SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT 9th International Conference on Fusion Reactor Materials (ICFRM-9) CY OCT 10-15, 1999 CL COLORADO SPRINGS, COLORADO SP US DOE, Off Fus Energy Sci, Argoone Natl Lab, Oak Ridge Natl Lab, Pacific NW Natl Lab, Univ Calif Santa Barbara, Amer Nucl Soc, Min Met & Mat Soc AB Attempts to correlate radiation-induced microstructural changes with changes in mechanical properties rely on a well-established theory to compute the resolved shear stress required to move dislocations through a field of obstacles. However, this microstructure-based shear stress must be converted to an equivalent uniaxial tensile stress in order to make comparisons with mechanical property measurements. A review of the radiation effects literature indicates that there is some confusion regarding the choice of this conversion factor for polycrystalline specimens. Some authors have used values of 1.73 and 2.0, based on an inappropriate application of the von Mises and Tresca yield criteria, respectively. The basic models pertinent to this area of research are reviewed, and it is concluded that the Taylor factor with a Value of 3.06 is the correct parameter to apply in such work. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Oak Ridge Natl Lab, Div Met & Ceram, Oak Ridge, TN 37831 USA. RP Stoller, RE (reprint author), Oak Ridge Natl Lab, Div Met & Ceram, Bldg 5500,POB 2008, Oak Ridge, TN 37831 USA. RI Stoller, Roger/H-4454-2011; OI Zinkle, Steven/0000-0003-2890-6915 NR 22 TC 95 Z9 95 U1 0 U2 8 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 DEC PY 2000 VL 283 BP 349 EP 352 DI 10.1016/S0022-3115(00)00378-0 PN A PG 4 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA 383HT UT WOS:000165877600059 ER PT J AU Shiba, K Klueh, RL Miwa, Y Robertson, JP Hishinuma, A AF Shiba, K Klueh, RL Miwa, Y Robertson, JP Hishinuma, A TI Tensile behavior of F82H with and without spectral tailoring SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT 9th International Conference on Fusion Reactor Materials (ICFRM-9) CY OCT 10-15, 1999 CL COLORADO SPRINGS, COLORADO SP US DOE, Off Fus Energy Sci, Argoone Natl Lab, Oak Ridge Natl Lab, Pacific NW Natl Lab, Univ Calif Santa Barbara, Amer Nucl Soc, Min Met & Mat Soc ID IRRADIATION AB The effects of neutron spectrum on tensile properties of the low-activation martensitic steel F82H (8Cr-2WVTa) was examined using a thermal neutron shield to tailor the neutron spectrum for steels irradiated in the high flux isotope reactor (HFIR). The yield stresses of spectrally tailored specimens irradiated in HFIR to 5 dpa at 300 degreesC and 500 degreesC are on trend lines obtained from unshielded irradiation in HFIR. No significant effect of the neutron spectrum on tensile properties could be detected. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Japan Atom Energy Res Inst, Dept Mat & Engn, Tokai, Ibaraki 3191195, Japan. Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Shiba, K (reprint author), Japan Atom Energy Res Inst, Dept Mat & Engn, Tokai, Ibaraki 3191195, Japan. NR 14 TC 10 Z9 13 U1 1 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3115 J9 J NUCL MATER JI J. Nucl. Mater. PD DEC PY 2000 VL 283 BP 358 EP 361 DI 10.1016/S0022-3115(00)00362-7 PN A PG 4 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA 383HT UT WOS:000165877600061 ER PT J AU Tsai, H Bray, TS Matsui, H Grossbeck, ML Fukumoto, K Gazda, J Billone, MC Smith, DL AF Tsai, H Bray, TS Matsui, H Grossbeck, ML Fukumoto, K Gazda, J Billone, MC Smith, DL TI Effects of low-temperature neutron irradiation on mechanical properties of vanadium-base alloys SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT 9th International Conference on Fusion Reactor Materials (ICFRM-9) CY OCT 10-15, 1999 CL COLORADO SPRINGS, COLORADO SP US DOE, Off Fus Energy Sci, Argoone Natl Lab, Oak Ridge Natl Lab, Pacific NW Natl Lab, Univ Calif Santa Barbara, Amer Nucl Soc, Min Met & Mat Soc AB Vanadium-base alloys were irradiated in three experiments to determine the effects of low-temperature neutron irradiation on their mechanical properties. The properties studied were tensile, Charpy impact and irradiation creep. The result of this study showed the alloys tested incurred significant hardening and embrittlement due to the irradiation. Heat-to-heat variations appeared to have little effect on hardening and embrittlement. Creep strains were measured from the specimens and a preliminary data set on creep strain rate was generated. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Argonne Natl Lab, Argonne, IL 60439 USA. Tohoku Univ, Inst Mat Res, Sendai, Miyagi 98077, Japan. Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. Adv Micro Devices Inc, Austin, TX 78741 USA. RP Tsai, H (reprint author), Argonne Natl Lab, 9700 S Cass Ave, Argonne, IL 60439 USA. NR 6 TC 14 Z9 17 U1 1 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3115 J9 J NUCL MATER JI J. Nucl. Mater. PD DEC PY 2000 VL 283 BP 362 EP 366 DI 10.1016/S0022-3115(00)00224-5 PN A PG 5 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA 383HT UT WOS:000165877600062 ER PT J AU Scholz, R Youngblood, GE AF Scholz, R Youngblood, GE TI Irradiation creep of advanced silicon carbide fibers SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT 9th International Conference on Fusion Reactor Materials (ICFRM-9) CY OCT 10-15, 1999 CL COLORADO SPRINGS, COLORADO SP US DOE, Off Fus Energy Sci, Argoone Natl Lab, Oak Ridge Natl Lab, Pacific NW Natl Lab, Univ Calif Santa Barbara, Amer Nucl Soc, Min Met & Mat Soc ID COMPOSITES AB The bend stress relaxation (BSR) method was applied to study irradiation enhanced creep (IEC) of small diameter silicon carbide (SiC) fibers after 10 MeV proton irradiation. A first series of tests was conducted on Sylramic(TM) fibers irradiated at 600 degreesC with average bending stresses of 400 and 667 MPa and for irradiation doses smaller than 0.04 dpa. The BSR results are compared to previously obtained torsional creep test results for the Textron SCS-6(TM) type SiC fibers by calculating the tensile equivalents for both testing methods. For the Sylramic fibers, the creep constant kappa = 4.7 x 10(-6) Mpa(-1) dpa(-1), was a factor of 6 smaller than the ri-value determined for SCS-6 fibers at 600 degreesC. In contrast, for T < 900C the kappa -value determined by R.J. Price [Nucl. Technol. 35 (1977) 320] for high purity monolithic beta -Si after 7.7 dpa neutron irradiation was only 0.4 x 10(-6) MPa-1 dpa(-1). (C) 2000 Elsevier Science B.V. All rights reserved. C1 Commiss European Communities, Joint Res Ctr, IHCP, I-21020 Ispra, Italy. Pacific NW Natl Lab, Richland, WA 99352 USA. RP Scholz, R (reprint author), Commiss European Communities, Joint Res Ctr, IHCP, TP 202,Via E Fermi 1, I-21020 Ispra, Italy. NR 12 TC 15 Z9 16 U1 1 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 DEC PY 2000 VL 283 BP 372 EP 375 DI 10.1016/S0022-3115(00)00264-6 PN A PG 4 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA 383HT UT WOS:000165877600064 ER PT J AU Hinoki, T Snead, LL Katoh, Y Kohyama, A Shinavski, R AF Hinoki, T Snead, LL Katoh, Y Kohyama, A Shinavski, R TI The effect of neutron-irradiation on the shear properties of SiC/SiC composites with varied interface SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT 9th International Conference on Fusion Reactor Materials (ICFRM-9) CY OCT 10-15, 1999 CL COLORADO SPRINGS, COLORADO SP US DOE, Off Fus Energy Sci, Argoone Natl Lab, Oak Ridge Natl Lab, Pacific NW Natl Lab, Univ Calif Santa Barbara, Amer Nucl Soc, Min Met & Mat Soc ID NICALON FIBERS; HI-NICALON(TM) AB The materials used in this study were unidirectional Hi-Nicalon(TM) SiC fibers reinforced SiC matrix composites. SiC/SiC composites were fabricated by chemical vapor infiltration (CVI) method. Fibers were coated with either pyrolytic carbon, multiple SiC layers or 'porous' SiC by CVI method prior to matrix deposition. They were irradiated in the High Flux Isotope Reactor at damage level of 0.5 dpa. Irradiation temperatures were either 300 degreesC or 500 degreesC. Interfacial shear properties and mechanical properties were evaluated. The correlation between interfacial shear properties and mechanical properties was examined. The 'porous' SiC interface showed a strong bond when compared with the pyrolytic C and multiple SiC interface in the non-irradiated state. The interfacial shear properties were substantially degraded by irradiation with the 'porous' SiC showing the most degradation. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Kyoto Univ, Inst Adv Energy, Kyoto 6110011, Japan. Oak Ridge Natl Lab, Oak Ridge, TN 37830 USA. Japan Sci & Techol Corp, ACE, CREST, Kawaguchi, Saitama 3320012, Japan. Hypertherm High Temp Composites, Huntington Beach, CA 92648 USA. RP Hinoki, T (reprint author), Kyoto Univ, Inst Adv Energy, Kyoto 6110011, Japan. OI Katoh, Yutai/0000-0001-9494-5862 NR 14 TC 11 Z9 11 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 DEC PY 2000 VL 283 BP 376 EP 379 DI 10.1016/S0022-3115(00)00279-8 PN A PG 4 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA 383HT UT WOS:000165877600065 ER PT J AU Garner, FA Toloczko, MB Greenwood, LR Eiholzer, CR Paxton, MM Puigh, RJ AF Garner, FA Toloczko, MB Greenwood, LR Eiholzer, CR Paxton, MM Puigh, RJ TI Swelling, irradiation creep and growth of pure rhenium irradiated with fast neutrons at 1030-1330 degrees C SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT 9th International Conference on Fusion Reactor Materials (ICFRM-9) CY OCT 10-15, 1999 CL COLORADO SPRINGS, COLORADO SP US DOE, Off Fus Energy Sci, Argoone Natl Lab, Oak Ridge Natl Lab, Pacific NW Natl Lab, Univ Calif Santa Barbara, Amer Nucl Soc, Min Met & Mat Soc ID ALLOYS AB This paper discusses the results of two series of experiments conducted on pure hcp rhenium in the EBR-II and FFTF fast reactors. In FFTF, density change data were derived from open tubes and solid rods irradiated at temperatures and fluences in the range of 1020-1250 degreesC and 4.4-8.3 x 10(22) n cm(-2), respectively (E > 0.1 MeV). Both density change and diametral change data were obtained from pressurized tubes irradiated in EBR-II to similar to0.65 and similar to5.1 x 10(22) n cm(-2) at temperatures between 1030 degreesC and 1330 degreesC. Analysis of the data shows that four concurrent processes contribute to the radiation-induced strains observed in these experiments. These are void swelling, transmutation-induced densification via production of osmium, irradiation creep and irradiation growth. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Pacific NW Natl Lab, Mat Resources Dept, Richland, WA 99352 USA. Fluor Daniel NW, Richland, WA USA. RP Garner, FA (reprint author), Pacific NW Natl Lab, Mat Resources Dept, 902 Battelle Blvd,P8-15, Richland, WA 99352 USA. RI Greenwood, Lawrence/H-9539-2016 OI Greenwood, Lawrence/0000-0001-6563-0650 NR 11 TC 7 Z9 7 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3115 J9 J NUCL MATER JI J. Nucl. Mater. PD DEC PY 2000 VL 283 BP 380 EP 385 DI 10.1016/S0022-3115(00)00225-7 PN A PG 6 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA 383HT UT WOS:000165877600066 ER PT J AU Uehira, A Mizuta, S Ukai, S Puigh, RJ AF Uehira, A Mizuta, S Ukai, S Puigh, RJ TI Irradiation creep of 11Cr-0.5Mo-2W, V, Nb ferritic-martensitic, modified 316, and 15Cr-20Ni austenitic SS irradiated in FFTF to 103-206 dpa SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT 9th International Conference on Fusion Reactor Materials (ICFRM-9) CY OCT 10-15, 1999 CL COLORADO SPRINGS, COLORADO SP US DOE, Off Fus Energy Sci, Argoone Natl Lab, Oak Ridge Natl Lab, Pacific NW Natl Lab, Univ Calif Santa Barbara, Amer Nucl Soc, Min Met & Mat Soc AB The irradiation creep of 11Cr-0.5Mo-2W-0.2V-0.05Nb ferritic-martensitic (PNC-FMS), modified 316 (PNC316) and 15Cr-20Ni base austenitic S.S. were determined by the gas pressurized capsule irradiation test using MOTA in FFTF. The pressurized capsules and open tubes were irradiated at 678-943 K to a peak dose of 206 dpa. The irradiation creep coefficients were derived from the diametral change differences between the capsules and open tubes, accounting for the stress-induced swelling. The creep compliance B-0 and creep-swelling coupling coefficient D for PNC-FMS were found to be 0.43-0.76 x 10(-6) MPa-1 dpa(-1) and 0.85-2.5 x 10(-2) MPa-1 for volumetric swelling, respectively. For both PNC316 and 15Cr-20Ni base S.S. the irradiation creep properties were very similar. B-0 and D range from 0.55 to -1.5 x 10(-6) MPa-1 dpa(-1) and from 1.2 to -2.8 x 10(-3) MPa-1, respectively. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Japan Nucl Cycle Dev Inst, Oarai Engn Ctr, Oarai, Ibaraki 3111393, Japan. Pacific NW Natl Lab, Richland, WA 99352 USA. RP Uehira, A (reprint author), Sumitomo Met Ind Ltd, Steel Tube Works, 1 Nishino, Amagasaki, Hyogo 6600856, Japan. NR 12 TC 11 Z9 11 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 DEC PY 2000 VL 283 BP 396 EP 399 DI 10.1016/S0022-3115(00)00079-9 PN A PG 4 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA 383HT UT WOS:000165877600069 ER PT J AU Pokrovsky, AS Fabritsiev, SA Edwards, DJ Zinkle, SJ Rowcliffe, AF AF Pokrovsky, AS Fabritsiev, SA Edwards, DJ Zinkle, SJ Rowcliffe, AF TI Effect of neutron dose and irradiation temperature on the mechanical properties and structure of dispersion strengthened copper alloys SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT 9th International Conference on Fusion Reactor Materials (ICFRM-9) CY OCT 10-15, 1999 CL COLORADO SPRINGS, COLORADO SP US DOE, Off Fus Energy Sci, Argoone Natl Lab, Oak Ridge Natl Lab, Pacific NW Natl Lab, Univ Calif Santa Barbara, Amer Nucl Soc, Min Met & Mat Soc AB This report is the first to present the data on the effect of neutron irradiation doses of 0.2 and 0.4 dpa at T-irr similar to 150 degreesC and T-irr similar to 300 degreesC on the mechanical properties of the GlidCopAl25IG alloy in different metallurgical conditions (CR + annealed, HIP, as-extruded). The dose dependence of radiation strengthening for GlidCopAl25IG alloy at T-test = T-irr = 150 degreesC shows that strengthening increases with dose, up to Delta sigma (y) similar to 100 MPa at 0.4 dpa. Simultaneously, the uniform elongation decreases with increasing dose. An important point is that all investigations on ODS copper alloys, regardless of the metallurgical state (CR + ann, HIP, as-extruded), revealed similar dose dependencies of strengthening and loss of ductility. Irradiation up to 0.4 dpa at 300 degreesC results in a slight strengthening of about 30 MPa of the ODS copper alloys. In this case the tendency to embrittlement depends on the metallurgical state and orientation of the specimens. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. Sci Res Inst Atom Reactors, Dimitrovgrad 433510, Russia. DV Efremov Sci Res Inst, St Petersburg 189631, Russia. Pacific NW Natl Lab, Richland, WA 99352 USA. RP Rowcliffe, AF (reprint author), Oak Ridge Natl Lab, POB 2008,Bldg 5500, Oak Ridge, TN 37831 USA. OI Zinkle, Steven/0000-0003-2890-6915 NR 6 TC 11 Z9 11 U1 0 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3115 J9 J NUCL MATER JI J. Nucl. Mater. PD DEC PY 2000 VL 283 BP 404 EP 408 DI 10.1016/S0022-3115(00)00226-9 PN A PG 5 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA 383HT UT WOS:000165877600071 ER PT J AU Toloczko, MB Hirth, JP Garner, FA AF Toloczko, MB Hirth, JP Garner, FA TI Application of generalized deformation theory to irradiation creep of fcc and bcc stainless steels SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT 9th International Conference on Fusion Reactor Materials (ICFRM-9) CY OCT 10-15, 1999 CL COLORADO SPRINGS, COLORADO SP US DOE, Off Fus Energy Sci, Argoone Natl Lab, Oak Ridge Natl Lab, Pacific NW Natl Lab, Univ Calif Santa Barbara, Amer Nucl Soc, Min Met & Mat Soc ID ABSORPTION AB The physical framework employed for most of the current irradiation creep models of cubic polycrystalline materials is a single crystal with a dislocation system consisting of three orthogonal Burgers vectors. The irradiation creep models based on this crystal system can be broken into two categories, one where irradiation creep occurs by dislocation climb alone, and the other where irradiation creep occurs by a combination of dislocation climb and glide. Often, irradiation creep is presumed to proceed by dislocation climb alone at low applied stresses, but by a combination of dislocation climb and glide at higher applied stresses. However, the rules for generalized deformation, as applied to dislocation climb, determine if a polycrystal is capable of deformation by dislocation climb alone. The current work analyzes generalized deformation by dislocation climb of fee and bcc stainless steel crystals. Some implications for irradiation creep of polycrystalline fee and bcc stainless steels are discussed. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Pacific NW Natl Lab, Richland, WA 99352 USA. Washington State Univ, Pullman, WA 99164 USA. RP Toloczko, MB (reprint author), Pacific NW Natl Lab, POB 999,MS P8-15, Richland, WA 99352 USA. NR 21 TC 3 Z9 3 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 DEC PY 2000 VL 283 BP 409 EP 413 DI 10.1016/S0022-3115(00)00080-5 PN A PG 5 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA 383HT UT WOS:000165877600072 ER PT J AU Hamilton, ML Garner, FA Toloczko, MB Maloy, SA Sommer, WF James, MR Ferguson, PD Louthan, MR AF Hamilton, ML Garner, FA Toloczko, MB Maloy, SA Sommer, WF James, MR Ferguson, PD Louthan, MR TI Shear punch and tensile measurements of mechanical property changes induced in various austenitic alloys by high-energy mixed proton and neutron irradiation at low temperatures SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT 9th International Conference on Fusion Reactor Materials (ICFRM-9) CY OCT 10-15, 1999 CL COLORADO SPRINGS, COLORADO SP US DOE, Off Fus Energy Sci, Argoone Natl Lab, Oak Ridge Natl Lab, Pacific NW Natl Lab, Univ Calif Santa Barbara, Amer Nucl Soc, Min Met & Mat Soc AB Tensile and shear punch tests of Inconel 718, 316L and 304L specimens irradiated with very high-energy protons and spallation neutrons showed that irradiation caused significant hardening and loss of uniform elongation. The specimens were irradiated at temperatures from room temperature to 150 degreesC in the Los Alamos Spallation Radiation Effects Facility (LASREF) at the Los Alamos Neutron Scattering Center (LANSCE). Dose levels ranged from 0.01 to 12 dpa. Most of the observed hardening for all three alloys occurred within the first 0.1 dpa (i.e., low dose) and before significant gas accumulation, indicating that gas generation may not play a significant role in the hardening or ductility loss. The correlations between tensile and shear punch data were as expected for yield strength but were unusual for the maximum strength in comparison with previous correlations based on fission-neutron-irradiated alloys. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Pacific NW Natl Lab, Richland, WA 99352 USA. Los Alamos Natl Lab, Los Alamos, NM USA. Savannah River Technol Ctr, Savannah, GA USA. RP Hamilton, ML (reprint author), Pacific NW Natl Lab, MS P8-15,POB 999, Richland, WA 99352 USA. RI Maloy, Stuart/A-8672-2009; OI Maloy, Stuart/0000-0001-8037-1319; Ferguson, Phillip/0000-0002-7661-4223 NR 6 TC 16 Z9 16 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 DEC PY 2000 VL 283 BP 418 EP 422 DI 10.1016/S0022-3115(00)00363-9 PN A PG 5 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA 383HT UT WOS:000165877600074 ER PT J AU Wakai, E Hashimoto, N Robertson, JP Jistukawa, S Sawai, T Hishinuma, A AF Wakai, E Hashimoto, N Robertson, JP Jistukawa, S Sawai, T Hishinuma, A TI Tensile properties and damage microstructures in ORR/HFIR-irradiated austenitic stainless steels SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT 9th International Conference on Fusion Reactor Materials (ICFRM-9) CY OCT 10-15, 1999 CL COLORADO SPRINGS, COLORADO SP US DOE, Off Fus Energy Sci, Argoone Natl Lab, Oak Ridge Natl Lab, Pacific NW Natl Lab, Univ Calif Santa Barbara, Amer Nucl Soc, Min Met & Mat Soc ID HFIR AB The synergistic effect of displacement damage and helium generation under neutron irradiation on tensile behavior and microstructures of austenitic stainless steels was investigated. The steels were irradiated at 400 degreesC in the spectrally-tailored (ST) Oak Ridge research reactor/high flux isotope reactor (ORR/HFIR) capsule to 17 dpa with a helium production of about 200 appm and in the HFIR target capsule to 21 and 34 dpa with 1590 and 2500 appm He, respectively. The increase of yield strength in the target irradiation was larger than that in the ST irradiation because of the high-number density of Frank loops, bubbles, voids, and carbides. Based on the theory of dispersed barrier hardening, the strengths evaluated from these clusters coincide with the measured increase of yield strengths. This analysis suggests that the main factors of radiation hardening in the ST and the target irradiation at 400 degreesC are Frank-type loops and cavities, respectively (C) 2000 Elsevier Science B.V. All rights reserved. C1 Japan Atom Energy Res Inst, Tokai Res Estab, Dept Mat Sci, Tokai, Ibaraki 3191195, Japan. Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Wakai, E (reprint author), Japan Atom Energy Res Inst, Tokai Res Estab, Dept Mat Sci, Tokai, Ibaraki 3191195, Japan. RI HASHIMOTO, Naoyuki/D-6366-2012; Wakai, Eiichi/L-1099-2016 NR 19 TC 8 Z9 8 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 DEC PY 2000 VL 283 BP 435 EP 439 DI 10.1016/S0022-3115(00)00082-9 PN A PG 5 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA 383HT UT WOS:000165877600077 ER PT J AU Klueh, RL Sokolov, MA Shiba, K Miwa, Y Robertson, JP AF Klueh, RL Sokolov, MA Shiba, K Miwa, Y Robertson, JP TI Embrittlement of reduced-activation ferritic/martensitic steels irradiated in HFIR at 300 degrees C and 400 degrees C SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT 9th International Conference on Fusion Reactor Materials (ICFRM-9) CY OCT 10-15, 1999 CL COLORADO SPRINGS, CO SP US DOE, Off Fus Energy Sci, Argonne Natl Lab, Oak Ridge Natl Lab, Pacific NW Natl Lab, Univ Calif Santa Barbara, Amer Nucl Soc, Min Met & Mat Soc AB Miniature tensile and Charpy specimens of four ferritic/martensitic steels were irradiated at 300 degreesC and 400 degreesC in the high flux isotope reactor (HFIR) to a maximum dose of approximate to 12 dpa. The steels were standard F82H (F82H-Std), a modified F82H (F82H-Mod), ORNL 9Cr-2WVTa, and 9Cr-2WVTa-2Ni, the 9Cr-2WVTa containing 2% Ni to produce helium by (n,alpha) reactions with thermal neutrons. More helium was produced in the F82H-Std than the F82H-Mod because of the presence of boron. Irradiation embrittlement in the form of an increase in the ductile-brittle transition temperature (Delta DBTT) and a decrease in the upper-shelf energy (USE) occurred for all the steels. The two F82H steels had similar Delta DBTTs after irradiation at 300 degreesC, but after irradiation at 400 degreesC, the Delta DBTT for F82H-Std was less than for F82H-Mod. Under these irradiation conditions, little effect of the extra helium in the F82H-Std could be discerned. Less embrittlement was observed for 9Cr-2WVTa steel irradiated at 400 degreesC than for the two F82H steels. The 9Cr-2WVTa-2Ni steel with approximate to 115 appm He had a larger Delta DBTT than the 9Cr-2WVTa with approximate to5 appm He, indicating a possible helium effect. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Oak Ridge Natl Lab, Div Met & Ceram, Oak Ridge, TN 37831 USA. Japan Atom Res Inst, Hitachinaka, Ibaraki 312, Japan. RP Klueh, RL (reprint author), Oak Ridge Natl Lab, Div Met & Ceram, POB 2008,MS 6376, Oak Ridge, TN 37831 USA. EM ku2@ornl.gov NR 12 TC 49 Z9 49 U1 0 U2 8 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 DEC PY 2000 VL 283 BP 478 EP 482 DI 10.1016/S0022-3115(00)00086-6 PN A PG 5 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA 383HT UT WOS:000165877600086 ER PT J AU Hamilton, ML Toloczko, MB AF Hamilton, ML Toloczko, MB TI Effect of low temperature irradiation on the mechanical properties of ternary V-Cr-Ti alloys as determined by tensile tests and shear punch tests SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT 9th International Conference on Fusion Reactor Materials (ICFRM-9) CY OCT 10-15, 1999 CL COLORADO SPRINGS, COLORADO SP US DOE, Off Fus Energy Sci, Argoone Natl Lab, Oak Ridge Natl Lab, Pacific NW Natl Lab, Univ Calif Santa Barbara, Amer Nucl Soc, Min Met & Mat Soc AB Tensile tests and shear punch tests were performed on a variety of vanadium alloys that were irradiated in the Advanced Test Reactor (ATR) at temperatures between 200 degreesC and 300 degreesC to doses between 3 and 5 dpa. Tests were performed at room temperature and the irradiation temperature. The results of both the tensile tests and the shear punch tests show that following low temperature irradiation, the yield strength (YS) increased by a factor of 3-4 while the ultimate strength increased by a factor of approximately 3. Uniform elongation (UE) and tensile reduction in area show that the ductility diminishes following irradiation. The correlation between uniaxial ultimate strength and effective shear maximum strength was in excellent agreement with previous studies on other materials. Using the room temperature test data, the correlation between uniaxial YS and effective shear YS was in excellent agreement with previous studies on other materials. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Pacific NW Natl Lab, Richland, WA 99352 USA. RP Hamilton, ML (reprint author), Pacific NW Natl Lab, MS P8-15,POB 999, Richland, WA 99352 USA. NR 11 TC 21 Z9 26 U1 0 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3115 J9 J NUCL MATER JI J. Nucl. Mater. PD DEC PY 2000 VL 283 BP 488 EP 491 DI 10.1016/S0022-3115(00)00227-0 PN A PG 4 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA 383HT UT WOS:000165877600088 ER PT J AU Fukumoto, KI Matsui, H Tsai, H Smith, DL AF Fukumoto, KI Matsui, H Tsai, H Smith, DL TI Mechanical behavior and microstructural evolution of vanadium alloys irradiated in ATR-A1 SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT 9th International Conference on Fusion Reactor Materials (ICFRM-9) CY OCT 10-15, 1999 CL COLORADO SPRINGS, COLORADO SP US DOE, Off Fus Energy Sci, Argoone Natl Lab, Oak Ridge Natl Lab, Pacific NW Natl Lab, Univ Calif Santa Barbara, Amer Nucl Soc, Min Met & Mat Soc AB An irradiation experiment has been done in the ATR-Al to investigate irradiation behavior of vanadium alloys in the low temperature regime from 200 degreesC to 300 degreesC with damage levels of 3 to 4 dpa. In creep measurements, creep tubes of V-3Fe-4Ti-0.1Si with inner pressures up to 165 MPa did not rupture during irradiation. The effective strain rate of creep was below 0.2% dpa(-1) and it showed the same tendency as V-4Cr-4Ti alloys. In Charpy impact tests, all specimens of V-4Cr-4Ti-0.1Si and V-3Fe-4Ti-0.1Si showed brittle behavior at room temperature and the DBTT increased to 60-150 degreesC. The fracture surface showed cleavage. Tensile tests conducted both at room temperature and at the irradiation temperature showed significant irradiation hardening and brittle responses. TEM showed that high densities of tiny defect clusters were formed in V-Cr-Ti and V-Fe-Ti alloys. Precipitates could not be seen in specimens irradiated below 300 degreesC, however, fine defect clusters are considered to be the origin of brittle behavior in V-Cr-Ti alloys irradiated at low temperatures. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Tohoku Univ, Mat Res Inst, Aoba Ku, Sendai, Miyagi 9808577, Japan. Argonne Natl Lab, Argonne, IL 60439 USA. RP Fukumoto, KI (reprint author), Tohoku Univ, Mat Res Inst, Aoba Ku, Katahira 2-1-1, Sendai, Miyagi 9808577, Japan. NR 12 TC 11 Z9 12 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3115 J9 J NUCL MATER JI J. Nucl. Mater. PD DEC PY 2000 VL 283 BP 492 EP 497 DI 10.1016/S0022-3115(00)00310-X PN A PG 6 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA 383HT UT WOS:000165877600089 ER PT J AU Rowcliffe, AF Zinkle, SJ Hoelzer, DT AF Rowcliffe, AF Zinkle, SJ Hoelzer, DT TI Effect of strain rate on the tensile properties of unirradiated and irradiated V-4Cr-4Ti SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT 9th International Conference on Fusion Reactor Materials (ICFRM-9) CY OCT 10-15, 1999 CL COLORADO SPRINGS, COLORADO SP US DOE, Off Fus Energy Sci, Argoone Natl Lab, Oak Ridge Natl Lab, Pacific NW Natl Lab, Univ Calif Santa Barbara, Amer Nucl Soc, Min Met & Mat Soc AB Tensile tests were carried out on an annealed, unirradiated V-4Cr-4Ti alloy from RT to 850 degreesC at strain rates ranging from 10(-1) to 10(-5) s(-1). Below 300 degreesC, where interstitial solutes are relatively immobile, deformation is homogeneous, and the strain rate sensitivity (SRS) of the yield and how stress is positive. Between 300 degreesC and 700 degreesC, the formation of solute atmospheres at locked dislocations results in dynamic strain-aging (DSA), deformation becomes heterogeneous, and the SRS of the flow stress is negative; in this regime the lower yield stress is independent of strain rate. Above 700 degreesC, substitutional solutes are also mobile, DSA declines, and the material enters a power law creep regime in which the SRS becomes positive again. Following neutron irradiation to 0.5 dpa at temperatures less than or equal to 400 degreesC, severe flow localization occurs due to the high number density of [110] and [111] loops. However, above 400 degreesC, strain hardening capacity returns but without the Luders extension. At 500 degreesC, after several percent plastic deformation, DSA occurs as interstitial solutes are released from the defect structure. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Rowcliffe, AF (reprint author), Oak Ridge Natl Lab, POB 2008,Bldg 5500, Oak Ridge, TN 37831 USA. RI Hoelzer, David/L-1558-2016; OI Zinkle, Steven/0000-0003-2890-6915 NR 15 TC 31 Z9 37 U1 1 U2 9 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3115 J9 J NUCL MATER JI J. Nucl. Mater. PD DEC PY 2000 VL 283 BP 508 EP 512 DI 10.1016/S0022-3115(00)00311-1 PN A PG 5 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA 383HT UT WOS:000165877600092 ER PT J AU Dai, Y Maloy, SA Bauer, GS Sommer, WF AF Dai, Y Maloy, SA Bauer, GS Sommer, WF TI Mechanical properties and microstructure in low-activation martensitic steels F82H and Optimax after 800-MeV proton irradiation SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT 9th International Conference on Fusion Reactor Materials (ICFRM-9) CY OCT 10-15, 1999 CL COLORADO SPRINGS, COLORADO SP US DOE, Off Fus Energy Sci, Argoone Natl Lab, Oak Ridge Natl Lab, Pacific NW Natl Lab, Univ Calif Santa Barbara, Amer Nucl Soc, Min Met & Mat Soc ID BEHAVIOR AB Low-activation martensitic steels, F82H (mod.) and Optimax-A, have been irradiated with 800-MeV protons up to 5.9 dpa. The tensile properties and microstructure have been studied. The results show that radiation hardening increases continuously with irradiation dose. F82H has lesser irradiation hardening as compared to Optimax-A in the present work and DIN1.4926 from a previous study. The irradiation embrittlement effects are evident in the materials since the uniform elongation is reduced sharply to less than 2%. However, all the irradiated samples ruptured in a ductile-fracture mode. Defect clusters have been observed. The size and the density of defect clusters increase with the irradiation dose. Precipitates are amorphous after irradiation. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Paul Scherrer Inst, Spallat Source Div, CH-5232 Villigen, Switzerland. Univ Calif Los Alamos Natl Lab, APT, TPO, Los Alamos, NM 87545 USA. RP Dai, Y (reprint author), Paul Scherrer Inst, Spallat Source Div, CH-5232 Villigen, Switzerland. RI Maloy, Stuart/A-8672-2009 OI Maloy, Stuart/0000-0001-8037-1319 NR 9 TC 33 Z9 33 U1 1 U2 6 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3115 J9 J NUCL MATER JI J. Nucl. Mater. PD DEC PY 2000 VL 283 BP 513 EP 517 DI 10.1016/S0022-3115(00)00267-1 PN A PG 5 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA 383HT UT WOS:000165877600093 ER PT J AU Fabritsiev, SA Pokrovsky, AS Edwards, DJ Zinkle, SJ Rowcliffe, AF AF Fabritsiev, SA Pokrovsky, AS Edwards, DJ Zinkle, SJ Rowcliffe, AF TI Effect of high-dose neutron irradiation on the mechanical properties and structure of copper alloys and Cu/SS joints for ITER applications SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT 9th International Conference on Fusion Reactor Materials (ICFRM-9) CY OCT 10-15, 1999 CL COLORADO SPRINGS, COLORADO SP US DOE, Off Fus Energy Sci, Argoone Natl Lab, Oak Ridge Natl Lab, Pacific NW Natl Lab, Univ Calif Santa Barbara, Amer Nucl Soc, Min Met & Mat Soc AB The base copper alloys Cu-Cs-Zr IG and GlidCopA125 IG and Cu/SS joints manufactured in Russian Federation (RF), United States (US), Europe (EU) and Japan (JA) with the HIP method were irradiated up to 2 dpa at 200 degreesC in SM-2 reactor. Tensile tests, shear tests, metallography and SEM investigations were performed. Mechanical test results on the base alloys and joints irradiated up to 2 dpa at 200 degreesC indicate that the trends established at lower dose (0.3-0.4 dpa) tests are still valid at higher doses. The main effect of the irradiation dose increase can be considered as a shift of the low temperature embrittlement towards higher temperatures. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. DV Efremov Sci Res Inst, St Petersburg 189631, Russia. Sci Res Inst Atom Reactors, Dimitrovgrad 433510, Russia. Pacific NW Natl Lab, Richland, WA 99352 USA. RP Rowcliffe, AF (reprint author), Oak Ridge Natl Lab, POB 2008,Bldg 5500, Oak Ridge, TN 37831 USA. OI Zinkle, Steven/0000-0003-2890-6915 NR 10 TC 12 Z9 12 U1 1 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 DEC PY 2000 VL 283 BP 523 EP 527 DI 10.1016/S0022-3115(00)00372-X PN A PG 5 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA 383HT UT WOS:000165877600095 ER PT J AU Hashimoto, N Zinkle, SJ Rowcliffe, AF Robertson, JP Jitsukawa, S AF Hashimoto, N Zinkle, SJ Rowcliffe, AF Robertson, JP Jitsukawa, S TI Deformation mechanisms in 316 stainless steel irradiated at 60 degrees C and 330 degrees C SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT 9th International Conference on Fusion Reactor Materials (ICFRM-9) CY OCT 10-15, 1999 CL COLORADO SPRINGS, COLORADO SP US DOE, Off Fus Energy Sci, Argoone Natl Lab, Oak Ridge Natl Lab, Pacific NW Natl Lab, Univ Calif Santa Barbara, Amer Nucl Soc, Min Met & Mat Soc ID MICROSTRUCTURAL EVOLUTION AB Plastically deformed microstructures in neutron-irradiated austenitic stainless steel were investigated by transmission electron microscopy (TEM). Neutron irradiation at 60 degreesC and 330 degreesC to about 7 dpa induced a high number density of faulted loops and black dots, which resulted in irradiation-induced hardening. In the specimen irradiated at 60 degreesC and tensile tested at 25 degreesC at a strain rate of 4x10(-4) s(-1), the deformation microstructure consisted of twins, elongated faulted loops, and lath and twin martensite phase. In the specimens irradiated and tested at 330 degreesC at a strain rate of 4x10(-4) and 4x10(-6) s(-1), in addition to these features, dislocation channeling was also observed. The TEM examination suggests that lath and twin martensite can form during tensile testing at both of these temperatures. Examination of the specimens irradiated and tensile tested at 330 degreesC indicated that twinning was the predominant deformation mode at slower strain rate and dislocation channeling was favored at higher temperature. From the micrographs taken from the {111} plane streak in a diffraction pattern, it is suggested that faulted loops could be the principal twin initiation site during deformation. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Oak Ridge Natl Lab, Div Met & Ceram, Oak Ridge, TN 37831 USA. Japan Atom Energy Res Inst, Tokai, Ibaraki 3191195, Japan. RP Hashimoto, N (reprint author), Oak Ridge Natl Lab, Div Met & Ceram, POB 2008,Bldg 5500,MS 6376, Oak Ridge, TN 37831 USA. RI HASHIMOTO, Naoyuki/D-6366-2012; OI Zinkle, Steven/0000-0003-2890-6915 NR 31 TC 60 Z9 61 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 DEC PY 2000 VL 283 BP 528 EP 534 DI 10.1016/S0022-3115(00)00087-8 PN A PG 7 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA 383HT UT WOS:000165877600096 ER PT J AU Snead, LL Yamada, R Noda, K Katoh, Y Zinkle, SJ Eatherly, WS Qualls, AL AF Snead, LL Yamada, R Noda, K Katoh, Y Zinkle, SJ Eatherly, WS Qualls, AL TI In situ thermal conductivity measurement of ceramics in a fast neutron environment SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT 9th International Conference on Fusion Reactor Materials (ICFRM-9) CY OCT 10-15, 1999 CL COLORADO SPRINGS, COLORADO SP US DOE, Off Fus Energy Sci, Argoone Natl Lab, Oak Ridge Natl Lab, Pacific NW Natl Lab, Univ Calif Santa Barbara, Amer Nucl Soc, Min Met & Mat Soc ID SILICON-CARBIDE; IRRADIATION AB A temperature controlled instrumented capsule has been irradiated in the RB* position of the high flux isotope reactor (HFIR) at the Oak Ridge National Laboratory in order to perform in situ thermal conductivity measurements of monolithic ceramics and composite materials during neutron irradiation. This determination of thermal conductivity utilizes a temperature gradient technique whereby two thermocouples measure the absolute temperature along a cylindrical sample which is constrained to one-dimensional thermal conduction. The heat source is the intrinsic gamma heating of the core region of the HFIR. This paper provides an overview of the experiment and gives preliminary results on the degradation in thermal conductivity of a few ceramic specimens measured as a function of irradiation temperature (200-700 degreesC) and fast neutron fluence up to similar to3.4x10(25) n/m(2) (E > 0.1 MeV). (C) 2000 Elsevier Science B.V. All rights reserved. C1 Oak Ridge Natl Lab, Div Met & Ceram, Oak Ridge, TN 37830 USA. Japan Atom Energy Res Inst, Tokai, Ibaraki 3191195, Japan. Kyoto Univ, Uji, Kyoto 611, Japan. RP Snead, LL (reprint author), Oak Ridge Natl Lab, Div Met & Ceram, POB 2008,MS-6087, Oak Ridge, TN 37830 USA. OI Zinkle, Steven/0000-0003-2890-6915; Katoh, Yutai/0000-0001-9494-5862 NR 18 TC 7 Z9 8 U1 0 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3115 J9 J NUCL MATER JI J. Nucl. Mater. PD DEC PY 2000 VL 283 BP 545 EP 550 DI 10.1016/S0022-3115(00)00237-3 PN A PG 6 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA 383HT UT WOS:000165877600099 ER PT J AU Snead, LL Katoh, Y Kohyama, A Bailey, JL Vaughn, NL Lowden, RA AF Snead, LL Katoh, Y Kohyama, A Bailey, JL Vaughn, NL Lowden, RA TI Evaluation of neutron irradiated near-stoichiometric silicon carbide fiber composites SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT 9th International Conference on Fusion Reactor Materials (ICFRM-9) CY OCT 10-15, 1999 CL COLORADO SPRINGS, CO SP US DOE, Off Fus Energy Sci, Argonne Natl Lab, Oak Ridge Natl Lab, Pacific NW Natl Lab, Univ Calif Santa Barbara, Amer Nucl Soc, Min Met & Mat Soc ID RADIATION AB Composites have been fabricated by chemical vapor infiltration of silicon carbide (SiC) into SiC-based fiber preforms. Fibers were Ceramic Grade Nicalon(TM), Hi-Nicalon(TM) and Hi-Nicalon(TM) Type-S. Results are presented for two parallel studies on the effects of neutron irradiation on these materials. In the first study, neutron irradiation induced changes in mechanical properties, as measured by bend testing, for Hi-Nicalon(TM) fiber materials of varied interphase structures is measured. Results indicate that both the Ceramic Grade Nicalon(TM) and Hi-Nicalon(TM) materials degrade substantially under irradiation, though the higher oxygen content Ceramic Grade fiber degrades more rapidly and more substantially Of the three interfaces studied in the Hi-Nicalon(TM) system, the multilayer SiC is the most radiation resistant. At a dose of similar to1 dpa the mechanical property degradation of the Hi-Nicalon(TM) composite is consistent with a fiber densification-induced debonding. At a dose of 10 dpa the properties continue to degrade raising the question of degradation in the CVD SiC matrix as well. Low-dose results on the Hi-Nicalon(TM) Type-S fabricated material are encouraging, as they appear to not lose, and perhaps slightly increase, in ultimate bend strength. This result is consistent with the supposition that as the oxygen content in SiC-based fibers is reduced, the irradiation stability and hence composite performance under irradiation will improve. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Oak Ridge Natl Lab, Div Met & Ceram, Oak Ridge, TN 37830 USA. Kyoto Univ, Uji, Kyoto, Japan. RP Snead, LL (reprint author), Oak Ridge Natl Lab, Div Met & Ceram, POB 2008,MS-6087, Oak Ridge, TN 37830 USA. EM z2n@ornl.gov OI Katoh, Yutai/0000-0001-9494-5862 NR 16 TC 60 Z9 61 U1 1 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 DEC PY 2000 VL 283 BP 551 EP 555 DI 10.1016/S0022-3115(00)00235-X PN A PG 5 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA 383HT UT WOS:000165877600100 ER PT J AU Kowbel, W Bruce, CA Tsou, KL Patel, K Withers, JC Youngblood, GE AF Kowbel, W Bruce, CA Tsou, KL Patel, K Withers, JC Youngblood, GE TI High thermal conductivity SiC/SiC composites for fusion applications SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT 9th International Conference on Fusion Reactor Materials (ICFRM-9) CY OCT 10-15, 1999 CL COLORADO SPRINGS, COLORADO SP US DOE, Off Fus Energy Sci, Argoone Natl Lab, Oak Ridge Natl Lab, Pacific NW Natl Lab, Univ Calif Santa Barbara, Amer Nucl Soc, Min Met & Mat Soc ID SILICON-CARBIDE AB SiC/SiC composites offer excellent potential for fusion energy as well as numerous commercial applications. High manufacturing cost and very low through-the-thickness (transverse) thermal conductivity (below 15 W/m K) hinders wider applications of SiC/SiC composites. To overcome these obstacles, a low cost chemical vapor reaction (CVR) process was developed to fabricate crystalline, high-purity SiC fibers. Several variations of the CVR process were used to fabricate SiC/SiC composites. An unirradiated, 4-mm thick SiC/SiC composite was completely CVR-converted from a converted SiC fiber preform with a pitch graphite matrix, and exhibited a bulk density of 2.65 g/cc, 10% open porosity, room temperature (RT) and 1000 degreesC thermal conductivity values of 70 and 35 W/m K, respectively, and an RT bend strength of 200 MPa. (C) 2000 Elsevier Science B.V. All rights reserved. C1 MER Corp, Tucson, AZ 85706 USA. Pacific NW Natl Lab, Richland, WA 99352 USA. RP Kowbel, W (reprint author), MER Corp, 7960 S Kolb Rd, Tucson, AZ 85706 USA. NR 8 TC 21 Z9 23 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 DEC PY 2000 VL 283 BP 570 EP 573 DI 10.1016/S0022-3115(00)00213-0 PN A PG 4 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA 383HT UT WOS:000165877600104 ER PT J AU Serizawa, H Ando, M Lewinsohn, CA Murakawa, H AF Serizawa, H Ando, M Lewinsohn, CA Murakawa, H TI New evaluation method of crack growth in SiC/SiC composites using interface elements SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT 9th International Conference on Fusion Reactor Materials (ICFRM-9) CY OCT 10-15, 1999 CL COLORADO SPRINGS, CO SP US DOE, Off Fus Energy Sci, Argonne Natl Lab, Oak Ridge Natl Lab, Pacific NW Natl Lab, Univ Calif Santa Barbara, Amer Nucl Soc, Min Met & Mat Soc ID NICALON FIBERS AB Crack propagation behavior in SiC/SiC composites was analyzed using a new computer simulation method that included time-dependent interface elements. The simulation method was used to describe the time-dependent crack growth in SiC/SiC composites under four-point bending of single-edge-notched beam bend-bars. Two methods were used to simulate time-dependent crack growth in SiC/SiC composites due to fiber creep. In one method, the creep property was introduced into the interface elements by the general method of finite element method (FEM) analysis. In the second method, a new technique making the best use of the potential function was used to represent crack closure tractions due to creeping fibers. The stage-II slow crack growth of a general creep deformation was simulated by both methods. Additionally, stage-III crack growth and the transition from stage-II to stage-III could be simulated by the new method. The new method has the potential to completely simulate time-dependent crack growth behavior in SiC/SiC composites due to fiber creep. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Osaka Univ, Joining & Welding Res Inst, Ibaraki, Osaka 5670047, Japan. Osaka Univ, Grad Sch Engn, Suita, Osaka 5650871, Japan. Pacific NW Natl Lab, Richland, WA 99352 USA. RP Osaka Univ, Joining & Welding Res Inst, 11-1 Mihogaoka, Ibaraki, Osaka 5670047, Japan. EM serizawa@jwri.osaka-u.ac.jp NR 12 TC 2 Z9 2 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 DEC PY 2000 VL 283 BP 579 EP 583 DI 10.1016/S0022-3115(00)00214-2 PN A PG 5 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA 383HT UT WOS:000165877600106 ER PT J AU Lewinsohn, CA Youngblood, GE Henager, CH Simonen, EP Jones, RH AF Lewinsohn, CA Youngblood, GE Henager, CH Simonen, EP Jones, RH TI Time-dependent failure mechanisms in silicon carbide composites for fusion energy applications SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT 9th International Conference on Fusion Reactor Materials (ICFRM-9) CY OCT 10-15, 1999 CL COLORADO SPRINGS, COLORADO SP US DOE, Off Fus Energy Sci, Argoone Natl Lab, Oak Ridge Natl Lab, Pacific NW Natl Lab, Univ Calif Santa Barbara, Amer Nucl Soc, Min Met & Mat Soc ID CERAMIC-MATRIX COMPOSITES; ELEVATED-TEMPERATURES; FIBER; NICALON; EMBRITTLEMENT; OXIDATION; CARBON AB Silicon carbide has many properties that are attractive for applications in fusion energy systems. The reliability of monolithic silicon carbide, however, is insufficient for its use in large components. Ceramic matrix composites offer greater flaw tolerance and reliability, but their failure mechanisms are less well understood. This work has focussed on studying potential failure mechanisms in silicon carbide fiber-reinforced, silicon carbide matrix (SiCf/SiCm) composites. In the event of pre-existing cracks, subcritical crack-growth may occur due to creep of fibers that bridge the crack faces. Irradiation-enhanced creep will enhance the subcritical crack-growth rate. The presence of oxygen leads to oxidation of the interphase material and subcritical crack-growth controlled by the rate of interphase recession. Tn addition, fiber shrinkage or weakening due to exposure to radiation can promote additional failure mechanisms, including embrittlement. These mechanisms, the conditions, under which they occur, and the current state of models of the crack-growth mechanisms will be discussed. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Pacific NW Natl Lab, Richland, WA 99352 USA. RP Lewinsohn, CA (reprint author), Pacific NW Natl Lab, MSIN P8-15,POB 999, Richland, WA 99352 USA. OI Henager, Chuck/0000-0002-8600-6803 NR 20 TC 2 Z9 2 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 DEC PY 2000 VL 283 BP 584 EP 587 DI 10.1016/S0022-3115(00)00109-4 PN A PG 4 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA 383HT UT WOS:000165877600107 ER PT J AU Hoelzer, DT West, MK Zinkle, SJ Rowcliffe, AF AF Hoelzer, DT West, MK Zinkle, SJ Rowcliffe, AF TI Solute interactions in pure vanadium and V-4Cr-4Ti alloy SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT 9th International Conference on Fusion Reactor Materials (ICFRM-9) CY OCT 10-15, 1999 CL COLORADO SPRINGS, COLORADO SP US DOE, Off Fus Energy Sci, Argoone Natl Lab, Oak Ridge Natl Lab, Pacific NW Natl Lab, Univ Calif Santa Barbara, Amer Nucl Soc, Min Met & Mat Soc AB Room temperature electrical resistivity and microhardness measurements were performed on cold-worked pure vanadium, solution annealed and cold-worked V-4Cr-4Ti ahoy and fusion weld material over the isochronal annealing temperature range from 200 degreesC to 1200 degreesC. The results suggest that Ti solutes in the vanadium alloy interact with interstitial O, C and N elements at temperatures of 200 degreesC and higher. This interaction lowers the effective diffusivity of the interstitials in the alloys, which shifts the interaction of interstitials with dislocations to higher temperatures as compared to the cold-worked vanadium. Over temperature ranges associated with recovery and recrystallization, general trends showed that the hardness decreased and resistivity first decreased but then increased in each material. Microstructural changes caused by precipitation and by reduction in dislocation density during. recrystallization may account for most of the differences observed in the measured properties of each material. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. Univ Tennessee, Dept Mat Sci & Engn, Knoxville, TN 37902 USA. RP Hoelzer, DT (reprint author), Oak Ridge Natl Lab, POB 2008,Bldg 5500, Oak Ridge, TN 37831 USA. RI Hoelzer, David/L-1558-2016; OI Zinkle, Steven/0000-0003-2890-6915 NR 15 TC 17 Z9 17 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3115 J9 J NUCL MATER JI J. Nucl. Mater. PD DEC PY 2000 VL 283 BP 616 EP 621 DI 10.1016/S0022-3115(00)00344-5 PN A PG 6 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA 383HT UT WOS:000165877600114 ER PT J AU Johnson, WR Trester, PW Sengoku, S Ishiyama, S Fukaya, K Eto, M Oda, T Hirohata, Y Hino, T Tsai, H AF Johnson, WR Trester, PW Sengoku, S Ishiyama, S Fukaya, K Eto, M Oda, T Hirohata, Y Hino, T Tsai, H TI Performance of V-4Cr-4Ti alloy exposed to the JFT-2M tokamak environment SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT 9th International Conference on Fusion Reactor Materials (ICFRM-9) CY OCT 10-15, 1999 CL COLORADO SPRINGS, COLORADO SP US DOE, Off Fus Energy Sci, Argoone Natl Lab, Oak Ridge Natl Lab, Pacific NW Natl Lab, Univ Calif Santa Barbara, Amer Nucl Soc, Min Met & Mat Soc AB A long-term test has been conducted in the JFT-2M tokamak fusion device to determine the effects of environmental exposure on the mechanical and chemical behavior of a V-4Cr-4Ti alloy. Test specimens of the alloy were exposed in the outward lower divertor chamber of JFT-2M in a region away from direct contact with the plasma and were preheated to 300 degreesC just prior to and during selected plasma discharges. During their nine-month residence time in JFT-2M, the specimens experienced approximately 200 lower-single-null divertor shots at 300 degreesC, during which high energy particle fluxes to the preheated test specimens were significant, and approximately 2010 upper-single-null divertor shots and non-divertor shots at room temperature, for which high energy particle fluxes to and expected particle retention in the test specimens were very low. Data from post-exposure tests have indicated that the performance of the V-4Cr-4Ti alloy would not be significantly affected by environmental exposure to gaseous species at partial pressures typical for tokamak operation. Deuterium retention in the exposed alloy was also low (<2 ppm). Absorption of interstitials by the alloy was limited to the very near surface, and neither the strength nor the Charpy impact properties of the alloy appeared to be significantly changed from the exposure to the JFT-2M tokamak environment. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Gen Atom Co, San Diego, CA 92186 USA. Japan Atom Energy Res Inst, Tokai, Ibaraki 3191195, Japan. Hokkaido Univ, Dept Nucl Engn, Sapporo, Hokkaido 0608628, Japan. Argonne Natl Lab, Argonne, IL 60439 USA. RP Johnson, WR (reprint author), Univ Calif Los Alamos Natl Lab, TA-53,Bldg 3R,Mail Stop H809, Los Alamos, NM 87545 USA. NR 15 TC 2 Z9 2 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 DEC PY 2000 VL 283 BP 622 EP 627 DI 10.1016/S0022-3115(00)00272-5 PN A PG 6 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA 383HT UT WOS:000165877600115 ER PT J AU Kurtz, RJ Hamilton, ML AF Kurtz, RJ Hamilton, ML TI Biaxial thermal creep of V-4Cr-4Ti at 700 degrees C and 800 degrees C SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT 9th International Conference on Fusion Reactor Materials (ICFRM-9) CY OCT 10-15, 1999 CL COLORADO SPRINGS, COLORADO SP US DOE, Off Fus Energy Sci, Argoone Natl Lab, Oak Ridge Natl Lab, Pacific NW Natl Lab, Univ Calif Santa Barbara, Amer Nucl Soc, Min Met & Mat Soc ID FUSION AB A study of the thermal creep properties of V-4Cr-4Ti were performed using pressurized tube specimens. Creep tubes nominally 4.57 mm OD by 0.25 mm wall thickness were pressurized with high-purity helium gas to mid-wall effective stresses below the uniaxial yield strength. Specimens were heated to 700 degreesC and 800 degreesC in an ultra-high vacuum furnace and periodically removed to measure the change in OD with a high-precision laser profilometer. The secondary creep rate was found to be power-law dependent on the applied stress with a stress exponent of 3.7 at 700 degreesC and 2.7 at 800 degreesC. The average activation energy for creep of V-4Cr-4Ti was 299 kJ/mol, which is quite close to the activation energy for self-diffusion in pure vanadium in this temperature regime. The predominant mechanism of creep deformation for the conditions employed in this study is most likely climb-assisted dislocation motion. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Pacific NW Natl Lab, Richland, WA 99352 USA. RP Kurtz, RJ (reprint author), Pacific NW Natl Lab, POB 999, Richland, WA 99352 USA. NR 17 TC 23 Z9 23 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 DEC PY 2000 VL 283 BP 628 EP 632 DI 10.1016/S0022-3115(00)00274-9 PN A PG 5 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA 383HT UT WOS:000165877600116 ER PT J AU Bray, TS Tsai, H Nowicki, LJ Billone, MC Smith, DL Johnson, WR Trester, PW AF Bray, TS Tsai, H Nowicki, LJ Billone, MC Smith, DL Johnson, WR Trester, PW TI Tensile and impact properties of V-4Cr-4Ti alloy heats 832665 and 832864 SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT 9th International Conference on Fusion Reactor Materials (ICFRM-9) CY OCT 10-15, 1999 CL COLORADO SPRINGS, COLORADO SP US DOE, Off Fus Energy Sci, Argoone Natl Lab, Oak Ridge Natl Lab, Pacific NW Natl Lab, Univ Calif Santa Barbara, Amer Nucl Soc, Min Met & Mat Soc AB Two large heats of V-4Cr-4Ti alloy were produced in the US in the past few years. The first, 832665, was a 500 kg heat procured by the US Department of Energy for basic fusion structural materials research. The second, 832864, was a 1300 kg heat procured by General Atomics for the DIII-D radiative divertor upgrade. Both heats were produced by Oremet-Wah Chang (previously Teledyne Wah Chang of Albany). Tensile properties up to 800 degreesC and Charpy V-notch impact properties down to liquid nitrogen temperature were measured for both heats. The product forms tested for both heats were rolled sheets annealed at 1000 degreesC for 1 h in vacuum. Testing results show the behavior of the two heats to be similar and the reduction of strengths with temperature to be insignificant up to at least 750 degreesC. Ductility of both materials is good in the test temperature range. Impact properties for both heats are excellent - no brittle failures at temperatures above -150 degreesC. Compared to the data for previous smaller laboratory heats of 15-50 kg, the results show that scale-up of vanadium alloy ingot production to sizes useful for reactor blanket design can be successfully achieved as long as reasonable process control is implemented (H. Tsai, et al., Fusion Materials Semiannual Progress Report for Period Ending 30th June 1998, DOE/ER-0313/24, p. 3; H. Tsai, et al., Fusion Materials Semiannual Progress Report for Period Ending 31st December 1998, DOE/ER-0313/25, p. 3). (C) 2000 Elsevier Science B.V. All rights reserved. C1 Argonne Natl Lab, Argonne, IL 60439 USA. Gen Atom Co, San Diego, CA 92186 USA. RP Bray, TS (reprint author), Argonne Natl Lab, 9700 S Cass Ave, Argonne, IL 60439 USA. NR 18 TC 11 Z9 11 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3115 J9 J NUCL MATER JI J. Nucl. Mater. PD DEC PY 2000 VL 283 BP 633 EP 636 DI 10.1016/S0022-3115(00)00229-4 PN A PG 4 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA 383HT UT WOS:000165877600117 ER PT J AU Romanoski, GR Snead, LL Klueh, RL Hoelzer, DT AF Romanoski, GR Snead, LL Klueh, RL Hoelzer, DT TI Development of an oxide dispersion strengthened, reduced-activation steel for fusion energy SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT 9th International Conference on Fusion Reactor Materials (ICFRM-9) CY OCT 10-15, 1999 CL COLORADO SPRINGS, COLORADO SP US DOE, Off Fus Energy Sci, Argoone Natl Lab, Oak Ridge Natl Lab, Pacific NW Natl Lab, Univ Calif Santa Barbara, Amer Nucl Soc, Min Met & Mat Soc AB A reduced-activation steel having a nominal chemical composition of Fe, 9% Cr, 2% W, 0.25% V, 0.1% Ta, and 0.1% C was mechanically alloyed with a fine dispersion of Y2O3 and TiO2 to assess the potential for extending the elevated temperature limit of this ahoy for structural applications. The total oxide dispersion content was varied from 0.25% to 1% and the molar ratio, TiO2/Y2O3 from 0 to 2. An argon atomized 9Cr2WVTa steel powder was ball milled under vacuum, extruded at 1150 degreesC to a 16 to 1 reduction in area, followed by a normalize and age heat treatment. Mechanical properties were assessed by elevated temperature tensile tests over the temperature range from room temperature to 800 degreesC. Transmission electron microscopy revealed a favorable dispersion of the oxide particles. Oxide dispersion strengthening by mechanical alloying resulted in significant improvement in elevated temperature tensile strengths. Extended ball-milling times improved oxide dispersion, microstructural refinement, and mechanical properties. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Romanoski, GR (reprint author), Oak Ridge Natl Lab, POB 2008,Bldg 4508,MS 6088, Oak Ridge, TN 37831 USA. RI Hoelzer, David/L-1558-2016; Romanoski, Glenn/E-5703-2017 OI Romanoski, Glenn/0000-0002-6874-5071 NR 14 TC 46 Z9 49 U1 2 U2 12 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3115 J9 J NUCL MATER JI J. Nucl. Mater. PD DEC PY 2000 VL 283 BP 642 EP 646 DI 10.1016/S0022-3115(00)00137-9 PN A PG 5 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA 383HT UT WOS:000165877600119 ER PT J AU Klueh, RL Hashimoto, N Buck, RF Sokolov, MA AF Klueh, RL Hashimoto, N Buck, RF Sokolov, MA TI A potential new ferritic/martensitic steel for fusion applications SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT 9th International Conference on Fusion Reactor Materials (ICFRM-9) CY OCT 10-15, 1999 CL COLORADO SPRINGS, COLORADO SP US DOE, Off Fus Energy Sci, Argoone Natl Lab, Oak Ridge Natl Lab, Pacific NW Natl Lab, Univ Calif Santa Barbara, Amer Nucl Soc, Min Met & Mat Soc AB The A-21 steel is an Fe-Cr-Co-Ni-Mo-Ti-C steel that is strengthened by a fine distribution of titanium carbide (TIC) precipitates formed by thermomechanical treatment. Transmission electron microscopy of the A-21 reveals a high number density of small TiC particles uniformly distributed in the matrix. Below approximate to 600 degreesC, the strength of A-21 is less than the average value for conventional Cr-Mo or reduced-activation ferritic/martensitic steels. However, the strength is greater above 600 degreesC. The Charpy impact properties of A-21 are comparable to those of the conventional and reduced-activation steels. Due to the fine TiC particles in the matrix, the creep-rupture properties of A-21 are superior to those of conventional Cr-Mo or reduced-activation Cr-W steels. Although the composition of the A-21 is not applicable for fusion because of the cobalt, the innovative production process may offer a route to an improved steel for fusion. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Oak Ridge Natl Lab, Div Met & Ceram, Oak Ridge, TN 37831 USA. Adv Steel Technol, Trafford, PA 15085 USA. RP Klueh, RL (reprint author), Oak Ridge Natl Lab, Div Met & Ceram, POB 2008,MS 6376, Oak Ridge, TN 37831 USA. RI HASHIMOTO, Naoyuki/D-6366-2012 NR 9 TC 9 Z9 9 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 DEC PY 2000 VL 283 BP 697 EP 701 DI 10.1016/S0022-3115(00)00113-6 PN A PG 5 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA 383HT UT WOS:000165877600131 ER PT J AU Smith, DL Majumdar, S Billone, M Mattas, R AF Smith, DL Majumdar, S Billone, M Mattas, R TI Performance limits for fusion first-wall structural materials SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT 9th International Conference on Fusion Reactor Materials (ICFRM-9) CY OCT 10-15, 1999 CL COLORADO SPRINGS, COLORADO SP US DOE, Off Fus Energy Sci, Argoone Natl Lab, Oak Ridge Natl Lab, Pacific NW Natl Lab, Univ Calif Santa Barbara, Amer Nucl Soc, Min Met & Mat Soc AB Key features of fusion energy relate primarily to potential advantages associated with safety and environmental considerations and the near endless supply of fuel. However, high-performance fusion power systems will be required in order to be an economically competitive energy option. As in most energy systems, the operating limits of structural materials pose a primary constraint to the performance of fusion power systems. In the case of fusion power, the first-wall/blanket system will have a dominant impact on both economic and safety/environmental attractiveness. This paper presents an assessment of the influence of key candidate structural material properties on performance limits for fusion first-wall blanket applications. Key issues associated with interactions of the structural materials with the candidate coolant/breeder materials are discussed. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Argonne Natl Lab, Fus Power Program, Argonne, IL 60439 USA. RP Smith, DL (reprint author), Argonne Natl Lab, Fus Power Program, 9700 S Cass Ave, Argonne, IL 60439 USA. NR 9 TC 7 Z9 7 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 DEC PY 2000 VL 283 BP 716 EP 720 DI 10.1016/S0022-3115(00)00315-9 PN A PG 5 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA 383HT UT WOS:000165877600135 ER PT J AU Heinisch, HL Singh, BN Golubov, SI AF Heinisch, HL Singh, BN Golubov, SI TI The effects of one-dimensional glide on the reaction kinetics of interstitial clusters SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT 9th International Conference on Fusion Reactor Materials (ICFRM-9) CY OCT 10-15, 1999 CL COLORADO SPRINGS, COLORADO SP US DOE, Off Fus Energy Sci, Argoone Natl Lab, Oak Ridge Natl Lab, Pacific NW Natl Lab, Univ Calif Santa Barbara, Amer Nucl Soc, Min Met & Mat Soc AB Collision cascades in metals produce small interstitial clusters and perfect dislocation loops that glide in thermally activated one-dimensional (1D) random walks. These gliding defects can change their Burgers vectors by thermal activation or by interactions with other defects. Their migration is therefore 'mixed 1D/3D migration' along a 3D path consisting of 1D segments, The defect reaction kinetics under mixed 1D/3D diffusion are different from pure 1D diffusion and pure 3D diffusion, both of which can be formulated within analytical rate theory models of microstructure evolution under irradiation. Atomic-scale kinetic Monte Carlo (kMC) defect migration simulations are used to investigate the effects of mixed 1D/3D migration on defect reaction kinetics as a guide for implementing mixed 1D/3D migration into the analytical rate theory. The functional dependence of the sink strength on the size and concentration of sinks under mixed 1D/3D migration is shown to lie between that for pure 1D and pure 3D migration and varies with L, the average distance between direction changes of the gliding defects. It is shown that the sink strength in simulations for spherical sinks of radius R under mixed 1D/3D migration for values of L greater than R can be approximated by an expression that varies directly as R-2. For small L, the form of the transition from mixed 1D/3D to pure 3D diffusion as L decreases is demonstrated in the simulations, the results of which can be used in the future development of an analytical expression describing this transition region. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Pacific NW Natl Lab, Richland, WA 99352 USA. Riso Natl Lab, Mat Res Dept, DK-4000 Roskilde, Denmark. Inst Phys & Power Engn, Obninsk, Russia. RP Heinisch, HL (reprint author), Pacific NW Natl Lab, P8-15,POB 999, Richland, WA 99352 USA. NR 7 TC 21 Z9 21 U1 1 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 DEC PY 2000 VL 283 BP 737 EP 740 DI 10.1016/S0022-3115(00)00258-0 PN B PG 4 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA 383HV UT WOS:000165877800001 ER PT J AU Stoller, RE Calder, AF AF Stoller, RE Calder, AF TI Statistical analysis of a library of molecular dynamics cascade simulations in iron at 100 K SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT 9th International Conference on Fusion Reactor Materials (ICFRM-9) CY OCT 10-15, 1999 CL COLORADO SPRINGS, COLORADO SP US DOE, Off Fus Energy Sci, Argoone Natl Lab, Oak Ridge Natl Lab, Pacific NW Natl Lab, Univ Calif Santa Barbara, Amer Nucl Soc, Min Met & Mat Soc ID DISPLACEMENT CASCADES; COMPUTER-SIMULATION; DEFECT PRODUCTION; ALPHA-IRON; METALS; BCC AB An extensive database of atomic displacement cascades in iron has been developed using molecular dynamics (MD) simulations. Simulations have been carried out at temperatures of 100, 600, and 900 K, and at energies between 0.10 and 50 keV. The results presented here focus on the simulations conducted at 100 K. A sufficient number of cascades has been completed under each condition of cascade energy and temperature to obtain statistically significant average values for the primary damage production parameters. The statistical analysis has been used to examine the influence of primary knockon direction, simulation cell-size, and lattice heating by the high energy recoil. A surprising effect of primary knockon atom (PKA) direction was observed up to 1 keV, but little effect of lattice heating was detected. We have previously reported preliminary results indicating that the ratio of surviving point defects to the number calculated by the Norgett-Robinson-Torrens (NRT) displacement model appears to pass through a minimum value of about 20 keV. The present analysis supports the statistical significance of this minimum, which call be attributed to the onset of extensive subcascade formation. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Oak Ridge Natl Lab, Div Met & Ceram, Oak Ridge, TN 37831 USA. Univ Liverpool, Liverpool L69 3BX, Merseyside, England. RP Stoller, RE (reprint author), Oak Ridge Natl Lab, Div Met & Ceram, POB 2008,Bldg 5500, Oak Ridge, TN 37831 USA. RI Stoller, Roger/H-4454-2011 NR 24 TC 62 Z9 63 U1 1 U2 10 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 DEC PY 2000 VL 283 BP 746 EP 752 DI 10.1016/S0022-3115(00)00074-X PN B PG 7 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA 383HV UT WOS:000165877800003 ER PT J AU Morishita, K de la Rubia, TD Alonso, E Sekimura, N Yoshida, N AF Morishita, K de la Rubia, TD Alonso, E Sekimura, N Yoshida, N TI A molecular dynamics simulation study of small cluster formation and migration in metals SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT 9th International Conference on Fusion Reactor Materials (ICFRM-9) CY OCT 10-15, 1999 CL COLORADO SPRINGS, COLORADO SP US DOE, Off Fus Energy Sci, Argoone Natl Lab, Oak Ridge Natl Lab, Pacific NW Natl Lab, Univ Calif Santa Barbara, Amer Nucl Soc, Min Met & Mat Soc ID EVOLUTION; CASCADE AB Molecular dynamics (MD) simulations were performed to investigate the kinetics and energetics of self-interstitial atom (SIA) clusters in vanadium, tantalum and copper. The formation energies of the SIA clusters in all the metals are well represented by a power function with a 0.75 exponent of the cluster size. The cluster diffusivities strongly depend on their structure. In vanadium and tantalum, all the SIA pairs in clusters are located along the [1 1 1] direction rather than the [1 1 0] direction. The clusters can migrate one-dimensionally in the [1 1 1] direction with a small activation energy of around 0.1 eV. In copper, the collective orientation preference of the SIA pairs is not observed indicating that rotation of several pairs in the cluster is required for the cluster to migrate. The activation energy for the rotation is not so high as the cluster migration energy itself. The difference in the SIA cluster migration behavior between bcc and fee metals is discussed. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Kyoto Univ, Inst Adv Energy, Uji, Kyoto 6110011, Japan. Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. Univ Tokyo, Dept Quantum Engn & Syst Sci, Bunkyo Ku, Tokyo 1138656, Japan. Kyushu Univ, Appl Mech Res Inst, Kasuga, Fukuoka 8168580, Japan. RP Morishita, K (reprint author), Kyoto Univ, Inst Adv Energy, Uji, Kyoto 6110011, Japan. RI U-ID, Kyushu/C-5291-2016; Kyushu, RIAM/F-4018-2015 NR 12 TC 8 Z9 8 U1 0 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3115 J9 J NUCL MATER JI J. Nucl. Mater. PD DEC PY 2000 VL 283 BP 753 EP 757 DI 10.1016/S0022-3115(00)00259-2 PN B PG 5 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA 383HV UT WOS:000165877800004 ER PT J AU Alonso, E Caturla, MJ de la Rubia, TD Soneda, N Marian, J Perlado, JM Stoller, RE AF Alonso, E Caturla, MJ de la Rubia, TD Soneda, N Marian, J Perlado, JM Stoller, RE TI Comparative study of damage accumulation in iron under magnetic and inertial fusion conditions SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT 9th International Conference on Fusion Reactor Materials (ICFRM-9) CY OCT 10-15, 1999 CL COLORADO SPRINGS, COLORADO SP US DOE, Off Fus Energy Sci, Argoone Natl Lab, Oak Ridge Natl Lab, Pacific NW Natl Lab, Univ Calif Santa Barbara, Amer Nucl Soc, Min Met & Mat Soc ID DEFECT PRODUCTION; COMPUTER-SIMULATION; MOLECULAR-DYNAMICS; ANNEALING KINETICS; EVOLUTION; METALS AB We present results of kinetic Monte Carlo (KMC) simulations of damage accumulation in Fe under conditions relevant to inertial (IFE) and magnetic fusion energy (MFE), with input obtained from molecular dynamics (MD). MD simulations provide information on the primary state of damage and were carried out for cascades with primary knockon atom (PKA) energies ranging from 100 eV to 50 keV. These were used as input for a KMC simulation in which pulsed IFE irradiation and continuous MFE irradiation were simulated and compared. The MD collision cascades were introduced into the KMC simulation reproducing a recoil spectrum of 14 MeV neutrons. For pulsed irradiation, we discuss the manner in which damage accumulates depending on temperature and pulse rate. At low temperature, we show that there is no significant difference between pulsed and continuous irradiation when the integrated dose rate is the same. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. Cent Res Inst Elect Power Ind, Tokyo 201, Japan. Univ Politecn Madrid, Inst Fus Nucl, Madrid, Spain. Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Alonso, E (reprint author), Univ Calif Lawrence Livermore Natl Lab, POB 808,L-369, Livermore, CA 94550 USA. RI Caturla, Maria /D-6241-2012; Stoller, Roger/H-4454-2011 OI Caturla, Maria /0000-0002-4809-6553; NR 29 TC 7 Z9 7 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 DEC PY 2000 VL 283 BP 768 EP 772 DI 10.1016/S0022-3115(00)00261-0 PN B PG 5 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA 383HV UT WOS:000165877800007 ER PT J AU Wirth, BD Bulatov, V de la Rubia, TD AF Wirth, BD Bulatov, V de la Rubia, TD TI Atomistic simulation of stacking fault tetrahedra formation in Cu SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT 9th International Conference on Fusion Reactor Materials (ICFRM-9) CY OCT 10-15, 1999 CL COLORADO SPRINGS, COLORADO SP US DOE, Off Fus Energy Sci, Argoone Natl Lab, Oak Ridge Natl Lab, Pacific NW Natl Lab, Univ Calif Santa Barbara, Amer Nucl Soc, Min Met & Mat Soc ID FCC METALS; MOLECULAR-DYNAMICS; VACANCY LOOPS; COPPER; CASCADES; ALLOYS AB Atomistic simulations based on the embedded atom method (EAM) are used to model the formation of stacking fault tetrahedra (SFT) in face centered cubic (fcc) Cu. SFTs are observed in fee metals following both irradiation and plastic deformation and have significant impact on defect accumulation and microstructural evolution of the irradiated material. Many authors have proposed SFT formation mechanisms; :however, a concise atomistic view is lacking. Starting from the vacancy-rich regions produced in high-energy displacement cascades, we have performed molecular dynamics (MD) simulations at a range of temperatures and observed SFT formation. In this work, we provide an atomistic picture of SFT formation. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Univ Calif Lawrence Livermore Natl Lab, Chem & Mat Sci Directorate, Livermore, CA 94551 USA. RP Wirth, BD (reprint author), Univ Calif Lawrence Livermore Natl Lab, Chem & Mat Sci Directorate, POB 808,L-353, Livermore, CA 94551 USA. RI Wirth, Brian/O-4878-2015 OI Wirth, Brian/0000-0002-0395-0285 NR 21 TC 49 Z9 49 U1 1 U2 21 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 DEC PY 2000 VL 283 BP 773 EP 777 DI 10.1016/S0022-3115(00)00262-2 PN B PG 5 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA 383HV UT WOS:000165877800008 ER PT J AU Malerba, L Perlado, JM Sanchez-Rubio, A Pastor, I Colombo, L de la Rubia, TD AF Malerba, L Perlado, JM Sanchez-Rubio, A Pastor, I Colombo, L de la Rubia, TD TI Molecular dynamics simulation of defect production in irradiated beta-SiC SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT 9th International Conference on Fusion Reactor Materials (ICFRM-9) CY OCT 10-15, 1999 CL COLORADO SPRINGS, COLORADO SP US DOE, Off Fus Energy Sci, Argoone Natl Lab, Oak Ridge Natl Lab, Pacific NW Natl Lab, Univ Calif Santa Barbara, Amer Nucl Soc, Min Met & Mat Soc ID INDUCED AMORPHIZATION; SILICON-CARBIDE; COMPUTER-SIMULATION; DAMAGE; POTENTIALS; DEPENDENCE; CERAMICS; BEHAVIOR AB We used the molecular dynamics (MD) code MDCASK, in which the Tersoff potential is implemented, to study the mechanisms of defect production due to Si- and C-recoils of different energies in beta -SiC. In this gaper, we highlight some of our most significant results to date. The threshold displacement energies (TDEs) for Si- and C-atoms have been accurately determined along four main crystallographic directions. The difficulty of defining a single TDE in this material, also because of the effect of temperature, is discussed. High-energy (various keV) recoil-induced displacement cascades have been simulated and it was found that defects on the C-sublattice always outnumber defects on the Si-sublattice, temperature scarcely affecting the number of Frenkel pairs produced within the cascade, Finally, our MD model seems to have proved satisfactory in reproducing the experimentally observed process of irradiation-induced amorphization of SiC at cryogenic temperature. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Univ Politecn Madrid, Inst Fus Nucl, DENIM, E-28006 Madrid, Spain. Univ Milan, Dipartimento Sci Mat, I-20125 Milan, Italy. Univ Calif Lawrence Livermore Natl Lab, Dept Chem & Mat Sci, Livermore, CA 94550 USA. RP Malerba, L (reprint author), Univ Politecn Madrid, Inst Fus Nucl, DENIM, C Jose Gutierrez Abascal 2, E-28006 Madrid, Spain. RI Colombo, Luciano/D-9013-2013 OI Colombo, Luciano/0000-0001-5335-4652 NR 22 TC 15 Z9 15 U1 0 U2 12 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3115 J9 J NUCL MATER JI J. Nucl. Mater. PD DEC PY 2000 VL 283 BP 794 EP 798 DI 10.1016/S0022-3115(00)00263-4 PN B PG 5 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA 383HV UT WOS:000165877800012 ER PT J AU Wakai, E Hashimoto, N Miwa, Y Robertson, JP Klueh, RL Shiba, K Jistukawa, S AF Wakai, E Hashimoto, N Miwa, Y Robertson, JP Klueh, RL Shiba, K Jistukawa, S TI Effect of helium production on swelling of F82H irradiated in HFIR SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT 9th International Conference on Fusion Reactor Materials (ICFRM-9) CY OCT 10-15, 1999 CL COLORADO SPRINGS, COLORADO SP US DOE, Off Fus Energy Sci, Argoone Natl Lab, Oak Ridge Natl Lab, Pacific NW Natl Lab, Univ Calif Santa Barbara, Amer Nucl Soc, Min Met & Mat Soc AB The effects of helium production and heat treatment on the swelling of F82H steel irradiated in the HFIR to 51 dpa have been investigated using B-10, Ni-58 and Ni-60-doped specimens. The swelling of tempered F82H-std and F82H doped with B-10 irradiated at 400 degreesC ranged from 0.52% to 1.2%, while the swelling of the non-tempered F82H doped with Ni-58 or Ni-60 was less than 0.02%. At 300 degreesC the swelling in all steels was insignificant. In the F82H + Ni, a high number of density carbides formed in the matrix at these temperatures. The production of helium atoms enhanced the swelling of the F82H steel. However, the non-tempered treatment for the F82H + Ni suppressed remarkably the swelling. The cause of low swelling in the F82H + Ni may be due to the occurrence of the high density of carbides acting as sinks or the decrease of mobility of vacancies interacting with carbon atoms in matrix. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Japan Atom Energy Res Inst, Dept Mat Sci Radiat Effects & Anal Mat, Tokai, Ibaraki 3191195, Japan. Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Wakai, E (reprint author), Japan Atom Energy Res Inst, Dept Mat Sci Radiat Effects & Anal Mat, Tokai, Ibaraki 3191195, Japan. RI HASHIMOTO, Naoyuki/D-6366-2012; Wakai, Eiichi/L-1099-2016 NR 12 TC 40 Z9 40 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 DEC PY 2000 VL 283 BP 799 EP 805 DI 10.1016/S0022-3115(00)00268-3 PN B PG 7 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA 383HV UT WOS:000165877800013 ER PT J AU Hasegawa, A Oliver, BM Nogami, S Abe, K Jones, RH AF Hasegawa, A Oliver, BM Nogami, S Abe, K Jones, RH TI Study of helium effects in SiC/SiC composites under fusion reactor environment SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT 9th International Conference on Fusion Reactor Materials (ICFRM-9) CY OCT 10-15, 1999 CL COLORADO SPRINGS, COLORADO SP US DOE, Off Fus Energy Sci, Argoone Natl Lab, Oak Ridge Natl Lab, Pacific NW Natl Lab, Univ Calif Santa Barbara, Amer Nucl Soc, Min Met & Mat Soc ID SILICON-CARBIDE; DIFFUSION; GRAPHITE AB Helium release behavior from He-ion implanted SiC/SiC, monolithic beta -SiC, and SiC fiber (Hi-Nicalon) was studied using the thermal desorption method with annealing temperatures between 500 degreesC and 1600 degreesC in 100 degreesC increments. Helium release from SiC/SiC composites began below 500 degreesC, while from monolithic beta -SiC, helium release was observed above 1000 degreesC. The magnitude of the helium released from beta -SiC was 1/10 to 1/50 of the helium released from the composites. Helium release from the fiber became apparent above 1300 degreesC. Helium release from composites at low temperature might be attributed to helium release from the carbon interphase. Behavior of transmuted helium in the SiC/SiC composites under fusion reactor conditions is discussed. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Tohoku Univ, Dept Quantum Sci & Energy Engn, Aoba Ku, Sendai, Miyagi 9808579, Japan. PNNL, Richland, WA 99352 USA. RP Hasegawa, A (reprint author), Tohoku Univ, Dept Quantum Sci & Energy Engn, Aoba Ku, Aramaki Aza Aoba, Sendai, Miyagi 9808579, Japan. NR 14 TC 13 Z9 14 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 DEC PY 2000 VL 283 BP 811 EP 815 DI 10.1016/S0022-3115(00)00375-5 PN B PG 5 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA 383HV UT WOS:000165877800015 ER PT J AU Kurtz, RJ AF Kurtz, RJ TI Effect of oxygen on the crack growth behavior of V-4Cr-4Ti at 600 degrees C SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT 9th International Conference on Fusion Reactor Materials (ICFRM-9) CY OCT 10-15, 1999 CL COLORADO SPRINGS, COLORADO SP US DOE, Off Fus Energy Sci, Argoone Natl Lab, Oak Ridge Natl Lab, Pacific NW Natl Lab, Univ Calif Santa Barbara, Amer Nucl Soc, Min Met & Mat Soc ID DYNAMIC EMBRITTLEMENT; TI ALLOYS; MODEL AB Exploratory experiments were performed to evaluate the effect of oxygen on the crack growth response of V-4Cr-4Ti at 600 degreesC under constant load. Tests were run in gettered argon, argon containing 2000 ppm oxygen,and laboratory air using fatigue pre-cracked compact-tension (CT) specimens. Crack growth was measured primarily by post-test fracture surface examination, but also by in-test compliance measurements. Crack growth rates measured in air and gettered argon were about 2-3 x 10(-3) mm/h at a stress intensity factor of about 40 MPa rootm. The crack growth rate in argon with 2000 ppm oxygen was about 7x10(-2) mm/h at the same stress intensity level. The crack growth rates were very sensitive to the stress intensity factor. Over a limited range of stress intensity values the crack growth rate in argon plus 2000 ppm oxygen appears to be power-law dependent on stress intensity with an exponent of about 8.9. The fracture mode in air and gettered argon was transgranular cleavage with 20-30% intergranular fracture. In the oxygenated argon environment crack growth occurred predominantly by transgranular cleavage. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Pacific NW Natl Lab, Richland, WA 99352 USA. RP Kurtz, RJ (reprint author), Pacific NW Natl Lab, POB 999, Richland, WA 99352 USA. NR 18 TC 3 Z9 3 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3115 J9 J NUCL MATER JI J. Nucl. Mater. PD DEC PY 2000 VL 283 BP 822 EP 826 DI 10.1016/S0022-3115(00)00273-7 PN B PG 5 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA 383HV UT WOS:000165877800017 ER PT J AU Gelles, DS AF Gelles, DS TI On quantification of helium embrittlement in ferritic/martensitic steels SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT 9th International Conference on Fusion Reactor Materials (ICFRM-9) CY OCT 10-15, 1999 CL COLORADO SPRINGS, COLORADO SP US DOE, Off Fus Energy Sci, Argoone Natl Lab, Oak Ridge Natl Lab, Pacific NW Natl Lab, Univ Calif Santa Barbara, Amer Nucl Soc, Min Met & Mat Soc ID LOW FLUENCE IRRADIATION; CR-MO STEELS AB Helium accumulation due to transmutation has long been considered a potential cause for embrittlement in ferritic/martensitic steels. Three Charpy impact databases involving nickel- and boron-doped alloys are quantified with respect to helium accumulation, and it is shown that all predict a very large effect of helium production on embrittlement. If these predictions are valid, then use of ferritic/martensitic steels for fusion first wall applications is highly unlikely. It is therefore necessary to reorient efforts regarding development of these steels for fusion applications to concentrate on the issue of helium embrittlement. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Pacific NW Natl Lab, Richland, WA 99352 USA. RP Gelles, DS (reprint author), Pacific NW Natl Lab, Mail Stop P8-15,POB 999, Richland, WA 99352 USA. NR 9 TC 14 Z9 14 U1 2 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 DEC PY 2000 VL 283 BP 838 EP 840 DI 10.1016/S0022-3115(00)00379-2 PN B PG 3 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA 383HV UT WOS:000165877800020 ER PT J AU DiStefano, JR Pint, BA DeVan, JH Rohrig, HD Chitwood, LD AF DiStefano, JR Pint, BA DeVan, JH Rohrig, HD Chitwood, LD TI Effects of oxygen and hydrogen at low pressure on the mechanical properties of V-Cr-Ti alloys SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT 9th International Conference on Fusion Reactor Materials (ICFRM-9) CY OCT 10-15, 1999 CL COLORADO SPRINGS, COLORADO SP US DOE, Off Fus Energy Sci, Argoone Natl Lab, Oak Ridge Natl Lab, Pacific NW Natl Lab, Univ Calif Santa Barbara, Amer Nucl Soc, Min Met & Mat Soc AB Exposure of V-Cr-Ti alloys to low oxygen partial pressures;It high temperature results in oxygen absorption and internal oxidation. Characterization of a V-4Cr-4Ti alloy after oxidation at 500 degreesC revealed a microstructure with ultrafine oxide precipitates in the matrix and along grain boundaries. Heat treatment at 950 degreesC following oxidation resulted in large TiOx precipitates in the matrix and grain boundaries. Tensile ductility was reduced by exposure to low-pressure oxygen under the temperature and pressure conditions. However, heat treatment at 950 degreesC following oxidation was generally effective in recovering ductility irrespective of initial annealing treatment or grain size. Without increases in oxygen, >500 wppm hydrogen was required to cause significant decreases in tensile elongation. When oxygen was added either during or prior to hydrogen exposure, significant embrittlement occurred with 100 wppm hydrogen. Because of this synergism with hydrogen, oxygen pick-up remains a major concern for V-Cr-Ti alloys in fusion reactor applications. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Oak Ridge Natl Lab, Div Met & Ceram, Oak Ridge, TN 37831 USA. Forschungszentrum Karlsruhe, Projektleitung Kernfus, D-76021 Karlsruhe, Germany. RP DiStefano, JR (reprint author), Oak Ridge Natl Lab, Div Met & Ceram, POB 2008, Oak Ridge, TN 37831 USA. RI Pint, Bruce/A-8435-2008 OI Pint, Bruce/0000-0002-9165-3335 NR 15 TC 24 Z9 27 U1 1 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 DEC PY 2000 VL 283 BP 841 EP 845 DI 10.1016/S0022-3115(00)00231-2 PN B PG 5 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA 383HV UT WOS:000165877800021 ER PT J AU Gritsyna, VT Afanasyev-Charkin, IV Kobyakov, VA Sickafus, KE AF Gritsyna, VT Afanasyev-Charkin, IV Kobyakov, VA Sickafus, KE TI Neutron irradiation effects in magnesium-aluminate spinel doped with transition metals SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT 9th International Conference on Fusion Reactor Materials (ICFRM-9) CY OCT 10-15, 1999 CL COLORADO SPRINGS, COLORADO SP US DOE, Off Fus Energy Sci, Argoone Natl Lab, Oak Ridge Natl Lab, Pacific NW Natl Lab, Univ Calif Santa Barbara, Amer Nucl Soc, Min Met & Mat Soc ID MGAL2O4 SPINELS; DAMAGE AB We present data on optical properties for stoichiometric (MgO . Al2O3) and non-stoichiometric (MgO . 2Al(2)O(3)) spinel crystals: (1) nominally pure; (2) doped with transition metals Mn, Cr, and Fe to a concentration of 0.01 wt%; (3) irradiated with neutrons to a fluence of 1.8x10(21) m(-2); (4) post-annealed at 650 K. The temperature during neutron irradiation was 350 K. Optical absorption and thermoluminescence measurements were performed on irradiated and annealed samples at room temperature. Results of absorption measurements show spectra with the following features: (1) a prominent band at 2.33 eV (for stoichiometric spinel); (2) overlapping bands attributed to hole centers (3.17 eV); (3) optical centers on antisite defects (3.78 and 4.14 eV); (4) F+-;and F-centers (4.75 and 5.3 eV); (5) bands related to defect complexes. For nominally pure samples, the efficiency of optical center formation in stoichiometric spinel is half that in non-stoichiometric spinel. Doped crystals exhibit high efficiencies for defect creation, independent of spinel composition. All dopants enhance the efficiency of defect creation in spinel. Doping with Mn has the least effect on increasing the number of radiation-induced stable defects. Apparently, impurities in spinel serve as centers for stabilization of irradiation-induced interstitials or vacancies. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Kharkov Natl Univ, Dept Phys & Technol, UA-61077 Kharkov, Ukraine. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Gritsyna, VT (reprint author), Kharkov Natl Univ, Dept Phys & Technol, Svoboda Sq 4, UA-61077 Kharkov, Ukraine. RI Gritsyna, Vasyl/J-9021-2016 OI Gritsyna, Vasyl/0000-0002-6734-3812 NR 14 TC 9 Z9 11 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 DEC PY 2000 VL 283 BP 927 EP 931 DI 10.1016/S0022-3115(00)00196-3 PN B PG 5 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA 383HV UT WOS:000165877800040 ER PT J AU Yasuda, K Kinoshita, C Fukuda, K Garner, FA AF Yasuda, K Kinoshita, C Fukuda, K Garner, FA TI Thermal stability and kinetics of defects in magnesium aluminate spinel irradiated with fast neutrons SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT 9th International Conference on Fusion Reactor Materials (ICFRM-9) CY OCT 10-15, 1999 CL COLORADO SPRINGS, COLORADO SP US DOE, Off Fus Energy Sci, Argoone Natl Lab, Oak Ridge Natl Lab, Pacific NW Natl Lab, Univ Calif Santa Barbara, Amer Nucl Soc, Min Met & Mat Soc ID MICROSTRUCTURAL EVOLUTION; DIFFUSION; CERAMICS; SPECTRUM; AL2O3; ION; MGO AB Thermal stability of interstitial-type dislocation loops and cavities in single crystals of MgAl2O4 was examined during isochronal and isothermal annealing. The specimens were irradiated with fast-neutrons in FFTF/MOTA at 658 and 1023 K up to 249 dpa. During the isochronal annealing, dislocation loops started to shrink around 1000 K and completely disappeared at 1470 K without changing their character. Cavities grew slightly around 1570 K, and above this temperature, cavities shrunk with increasing annealing temperature. The recovery stage of point defects in MgAl2O4 was discussed in terms of the thermal stability of defect clusters; vacancy migration starts around 1000 K (corresponding to stage III), whereas vacancy clusters start to dissociate around 1570 K (corresponding to stage V). The vacancy migration energy for rate controlling species was estimated from the shrinkage process of interstitial-type dislocation loops to be 2.0 +/- 0.7 eV. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Kyushu Univ 36, Dept Appl Quantum Phys & Nucl Engn, Fukuoka 8128581, Japan. Pacific NW Natl Lab, Richland, WA 99352 USA. RP Yasuda, K (reprint author), Kyushu Univ 36, Dept Appl Quantum Phys & Nucl Engn, Hakozaki 6-10-1, Fukuoka 8128581, Japan. NR 20 TC 15 Z9 15 U1 3 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 DEC PY 2000 VL 283 BP 937 EP 941 DI 10.1016/S0022-3115(00)00118-5 PN B PG 5 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA 383HV UT WOS:000165877800042 ER PT J AU Soeda, T Matsumura, S Kinoshita, C Zaluzec, NJ AF Soeda, T Matsumura, S Kinoshita, C Zaluzec, NJ TI Cation disordering in magnesium aluminate spinel crystals induced by electron or ion irradiation SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT 9th International Conference on Fusion Reactor Materials (ICFRM-9) CY OCT 10-15, 1999 CL COLORADO SPRINGS, COLORADO SP US DOE, Off Fus Energy Sci, Argoone Natl Lab, Oak Ridge Natl Lab, Pacific NW Natl Lab, Univ Calif Santa Barbara, Amer Nucl Soc, Min Met & Mat Soc ID LIGHT-ELEMENTS; RESISTANCE; CERAMICS; ALCHEMI; DAMAGE; SITE AB Structural changes in magnesium aluminate spinel (MgO . nAl(2)O(3)) single crystals, which were irradiated with 900 keV electrons or 1 MeV Ne+ ions at 873 K, were examined by electron channeling enhanced X-ray microanalysis. Unirradiated MgO . Al2O3 has a tendency to form the normal spinel configuration, where Mg2+ ions and Al3+ ions occupy mainly the tetrahedral and the octahedral sites, respectively. Electron irradiation induces simple cation disordering between the tetrahedral sites and the octahedral sites in MgO . Al2O3 In addition to cation disordering, slight evacuation of cations from the tetrahedral sites to the octahedral sites occurs in a peak-damaged area in MgO . Al2O3 irradiated with Ne+ ions. In contrast, cation disordering is suppressed in MgO .2.4Al(2)O(3) irradiated with electrons. The structural vacancies, present in the non-stoichiometric compound, appear to be effective in promoting irradiation damage recovery through interstitial-vacancy recombination. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Kyushu Univ, Dept Appl Quantum Phys & Nucl Engn, Fukuoka 8128581, Japan. Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. RP Soeda, T (reprint author), Kyushu Univ, Dept Appl Quantum Phys & Nucl Engn, Fukuoka 8128581, Japan. NR 20 TC 38 Z9 38 U1 2 U2 9 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3115 J9 J NUCL MATER JI J. Nucl. Mater. PD DEC PY 2000 VL 283 BP 952 EP 956 DI 10.1016/S0022-3115(00)00164-1 PN B PG 5 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA 383HV UT WOS:000165877800045 ER PT J AU Belyakov, VA Fabritsiev, SA Mazul, IV Rowcliffe, AF AF Belyakov, VA Fabritsiev, SA Mazul, IV Rowcliffe, AF TI Status of international collaborative efforts on selected ITER materials SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT 9th International Conference on Fusion Reactor Materials (ICFRM-9) CY OCT 10-15, 1999 CL COLORADO SPRINGS, COLORADO SP US DOE, Off Fus Energy Sci, Argoone Natl Lab, Oak Ridge Natl Lab, Pacific NW Natl Lab, Univ Calif Santa Barbara, Amer Nucl Soc, Min Met & Mat Soc ID COPPER-ALLOYS AB The paper presents an overview of the performance of refractory metals, beryllium, and copper alloys, for the international thermonuclear experimental reactor (ITER) high heat flux structures. High temperature brazing, hot isostatic pressing (HIP), friction welding, explosive bonding, and other methods were explored to join copper alloys to 316 stainless steel for first wall and limiter applications. It is concluded that the main material problems for the ITER high heat flux components are: (a) degradation of properties after the manufacturing cycle (especially for Be/Cu and Cu/stainless steel (SS) joints); (b) helium embrittlement of Be, and Cu, and; (c) radiation-induced loss of fracture toughness for Be, W, and Cu alloys. (C) 2000 Elsevier Science B.V. All rights reserved. C1 DV Efremov Sci & Res Inst Electrophys Apparatus, St Petersburg 189631, Russia. Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Belyakov, VA (reprint author), DV Efremov Sci & Res Inst Electrophys Apparatus, Sovetsky Pr 1, St Petersburg 189631, Russia. NR 17 TC 2 Z9 3 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3115 J9 J NUCL MATER JI J. Nucl. Mater. PD DEC PY 2000 VL 283 BP 962 EP 967 DI 10.1016/S0022-3115(00)00233-6 PN B PG 6 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA 383HV UT WOS:000165877800047 ER PT J AU Li, M Heuer, JK Stubbins, JF Edwards, DJ AF Li, M Heuer, JK Stubbins, JF Edwards, DJ TI Fracture behavior of high-strength, high-conductivity copper alloys SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT 9th International Conference on Fusion Reactor Materials (ICFRM-9) CY OCT 10-15, 1999 CL COLORADO SPRINGS, COLORADO SP US DOE, Off Fus Energy Sci, Argoone Natl Lab, Oak Ridge Natl Lab, Pacific NW Natl Lab, Univ Calif Santa Barbara, Amer Nucl Soc, Min Met & Mat Soc AB The fracture behavior of three copper alloys, namely, one dispersion-strengthened alloy: GlidCop(TM)CuAl25, and two precipitation-hardened alloys: Hycon3HP(TM)CuNiBe and Elbrodur CuCrZr, was investigated in the temperature range 20-300 degreesC in vacuum. The results show that all these three alloys experienced a loss of fracture resistance with increasing test temperature. In the case of the CuNiBe alloy, the fracture resistance drops very rapidly as test temperature increases, and the other two alloys also experience drops in toughness, but not quite to the same extent. In fact, the fracture resistance of CuCrZr is affected only moderately by test temperature. The reduction of fracture resistance with increasing temperature in vacuum shows that the environment is not the only factor responsible for poor toughness. Further, microstructural analysis of the CuNiBe alloy shows that changes in grain boundary microstructure resulted from discontinuous precipitation. This is assumed to have a significant effect on the fracture behavior of this alloy. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Univ Illinois, Nucl Engn Lab 214, Dept Nucl Plasma & Radiol Engn, Urbana, IL 61801 USA. Pacific NW Natl Lab, Richland, WA 99352 USA. RP Stubbins, JF (reprint author), Univ Illinois, Nucl Engn Lab 214, Dept Nucl Plasma & Radiol Engn, 103 S Goodwin Ave, Urbana, IL 61801 USA. NR 4 TC 14 Z9 14 U1 1 U2 6 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3115 J9 J NUCL MATER JI J. Nucl. Mater. PD DEC PY 2000 VL 283 BP 977 EP 981 DI 10.1016/S0022-3115(00)00316-0 PN B PG 5 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA 383HV UT WOS:000165877800050 ER PT J AU Toloczko, MB Hamilton, ML Lucas, GE AF Toloczko, MB Hamilton, ML Lucas, GE TI Ductility correlations between shear punch and uniaxial tensile test data SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT 9th International Conference on Fusion Reactor Materials (ICFRM-9) CY OCT 10-15, 1999 CL COLORADO SPRINGS, COLORADO SP US DOE, Off Fus Energy Sci, Argoone Natl Lab, Oak Ridge Natl Lab, Pacific NW Natl Lab, Univ Calif Santa Barbara, Amer Nucl Soc, Min Met & Mat Soc AB The shear punch test was developed to address the need of the fusion reactor structural materials community for small scale mechanical properties tests. It has been demonstrated that effective shear strength data obtained from the shear punch test can be linearly related to uniaxial tensile strength for a wide variety of alloys. The current work explores the existence of a similar relationship between shear punch, test data and both the tensile strain hardening exponent and the uniform elongation. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Pacific NW Natl Lab, Richland, WA 99352 USA. Univ Calif Santa Barbara, Santa Barbara, CA 93106 USA. RP Toloczko, MB (reprint author), Pacific NW Natl Lab, Richland, WA 99352 USA. NR 10 TC 41 Z9 42 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 DEC PY 2000 VL 283 BP 987 EP 991 DI 10.1016/S0022-3115(00)00198-7 PN B PG 5 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA 383HV UT WOS:000165877800052 ER PT J AU Oliver, BM Garner, FA Greenwood, LR Abrefah, JA AF Oliver, BM Garner, FA Greenwood, LR Abrefah, JA TI High-sensitivity quadrupole mass spectometry system for the determination of hydrogen in irradiated materials SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT 9th International Conference on Fusion Reactor Materials (ICFRM-9) CY OCT 10-15, 1999 CL COLORADO SPRINGS, COLORADO SP US DOE, Off Fus Energy Sci, Argoone Natl Lab, Oak Ridge Natl Lab, Pacific NW Natl Lab, Univ Calif Santa Barbara, Amer Nucl Soc, Min Met & Mat Soc AB High levels of helium and hydrogen are generated in metals in fusion reactors, and fusion simulations in mixed-spectrum fission reactors, spallation neutron sources, and high-energy charged particle environments. Although hydrogen generation rates are generally higher than those of helium, hydrogen is thought to quickly diffuse out of metals, especially at elevated temperatures. There appear to be some conditions, however, where significant hydrogen retention can occur. To assess this potential, a high-sensitivity analysis system has been developed for the measurement of hydrogen in small samples of irradiated materials. The system is based on a low-volume extraction furnace in combination with a quadrupole mass spectrometer, and has a detection limit of similar to1 appm for steel. Hydrogen levels have been measured in high-energy proton-irradiated tungsten and Inconel 718, in iron-based alloys and vanadium alloys from fusion materials programs, and in stainless steels and pure metals irradiated in light water reactors. Details of the system and typical results are presented. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Pacific NW Natl Lab, Richland, WA 99352 USA. RP Oliver, BM (reprint author), Pacific NW Natl Lab, POB 999, Richland, WA 99352 USA. RI Greenwood, Lawrence/H-9539-2016 OI Greenwood, Lawrence/0000-0001-6563-0650 NR 5 TC 17 Z9 17 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 DEC PY 2000 VL 283 BP 1006 EP 1010 DI 10.1016/S0022-3115(00)00200-2 PN B PG 5 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA 383HV UT WOS:000165877800056 ER PT J AU Kohno, Y Kohyama, A Hamilton, ML Hirose, T Katoh, Y Garner, FA AF Kohno, Y Kohyama, A Hamilton, ML Hirose, T Katoh, Y Garner, FA TI Specimen size effects on the tensile properties of JPCA and JFMS SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT 9th International Conference on Fusion Reactor Materials (ICFRM-9) CY OCT 10-15, 1999 CL COLORADO SPRINGS, COLORADO SP US DOE, Off Fus Energy Sci, Argoone Natl Lab, Oak Ridge Natl Lab, Pacific NW Natl Lab, Univ Calif Santa Barbara, Amer Nucl Soc, Min Met & Mat Soc ID STEELS AB Examinations of specimen size effects on tensile properties were performed with and without neutron irradiation. Specimen thickness was varied to investigate the effect of aspect ratio as well as the thickness itself. Thickness dependence of yield stress, aspect ratio dependence of ultimate stress and aspect ratio dependence of ultimate strain showed good consistency and reproducibility even in heavy neutron irradiation condition. The effect of specimen size on yield stress and ultimate stress was small, but the ductility showed significant dependence on specimen aspect ratio. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Muroran Inst Technol, Dept Mat Sci & Engn, Muroran, Hokkaido 0508585, Japan. Kyoto Univ, Inst Adv Energy, Kyoto 6110011, Japan. Battelle Pacific NW Natl Lab, Richland, WA 99352 USA. RP Kohno, Y (reprint author), Muroran Inst Technol, Dept Mat Sci & Engn, Mizumoto 27-1, Muroran, Hokkaido 0508585, Japan. OI Katoh, Yutai/0000-0001-9494-5862 NR 16 TC 18 Z9 18 U1 3 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 DEC PY 2000 VL 283 BP 1014 EP 1017 DI 10.1016/S0022-3115(00)00245-2 PN B PG 4 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA 383HV UT WOS:000165877800058 ER PT J AU Nakamura, H O'hira, S Shu, W Nishi, M Venhaus, TJ Causey, RA Hyatt, DR Willms, RS AF Nakamura, H O'hira, S Shu, W Nishi, M Venhaus, TJ Causey, RA Hyatt, DR Willms, RS TI Tritium permeation experiment using a tungsten armored divertor-simulating module SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT 9th International Conference on Fusion Reactor Materials (ICFRM-9) CY OCT 10-15, 1999 CL COLORADO SPRINGS, COLORADO SP US DOE, Off Fus Energy Sci, Argoone Natl Lab, Oak Ridge Natl Lab, Pacific NW Natl Lab, Univ Calif Santa Barbara, Amer Nucl Soc, Min Met & Mat Soc ID PLASMA; TRANSPORT AB A first engineering type experiment for evaluation of tritium permeation rate through a tungsten armored divertor of a DT fusion machine was carried out using tritium plasma experimental (TPE) apparatus under the collaborative program between US-DOE and JAERI. A test module having a multi-layer structure (W:1 mm(t), Cu:5 mm(t) and a cavity containing water pressurized at 2.2 MPa) was exposed to DT (D:T = 2:1) plasma. Break-through of tritium permeation into the water was observed after 4 h of plasma exposure. The amount of tritium permeated was compared with permeation rates predicted by numerical simulation codes (TMAP4 and TPERM). Feasibility of the experimental system and procedures to predict the tritium permeation behavior was examined using the simulation codes. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Japan Atom Energy Res Inst, Tritium Engn Lab, Tokai, Ibaraki 3191195, Japan. Sandia Natl Labs, Livermore, CA 94550 USA. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Nakamura, H (reprint author), Japan Atom Energy Res Inst, Tritium Engn Lab, Tokai, Ibaraki 3191195, Japan. NR 15 TC 4 Z9 6 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3115 J9 J NUCL MATER JI J. Nucl. Mater. PD DEC PY 2000 VL 283 BP 1043 EP 1047 DI 10.1016/S0022-3115(00)00283-X PN B PG 5 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA 383HV UT WOS:000165877800064 ER PT J AU Hollis, KJ Castro, RG Maggiore, CJ Ayala, A AF Hollis, KJ Castro, RG Maggiore, CJ Ayala, A TI The removal of ion implanted deuterium from tungsten and stainless steel by transferred-arc cleaning SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT 9th International Conference on Fusion Reactor Materials (ICFRM-9) CY OCT 10-15, 1999 CL COLORADO SPRINGS, COLORADO SP US DOE, Off Fus Energy Sci, Argoone Natl Lab, Oak Ridge Natl Lab, Pacific NW Natl Lab, Univ Calif Santa Barbara, Amer Nucl Soc, Min Met & Mat Soc ID CODEPOSITED LAYERS AB Tungsten and stainless steel samples have been ion implanted with deuterium in an accelerator to simulate hydrogen isotope ion implantation conditions in magnetic confinement fusion devices. The samples were characterized by ion beam analysis both before and after cleaning to determine deuterium concentrations present. The extent of transferred-arc (TA) cleaning was varied to determine the deuterium removal efficiency, surface roughening and sample erosion rate. The deuterium content was greatly reduced by the cleaning thus demonstrating the possibility of using the TA cleaning technique for removing deuterium from components exposed to D-T fuels. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Univ Calif Los Alamos Natl Lab, Div Mat Sci & Technol, Los Alamos, NM 87544 USA. RP Hollis, KJ (reprint author), Univ Calif Los Alamos Natl Lab, Div Mat Sci & Technol, POB 1663,MS G-770, Los Alamos, NM 87544 USA. NR 11 TC 5 Z9 5 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 DEC PY 2000 VL 283 BP 1085 EP 1088 DI 10.1016/S0022-3115(00)00327-5 PN B PG 4 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA 383HV UT WOS:000165877800073 ER PT J AU Hassanein, A Konkashbaev, I AF Hassanein, A Konkashbaev, I TI Hydrodynamic effects of eroded materials of plasma-facing component during a Tokamak disruption SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT 9th International Conference on Fusion Reactor Materials (ICFRM-9) CY OCT 10-15, 1999 CL COLORADO SPRINGS, CO SP US DOE, Off Fus Energy Sci, Argonne Natl Lab, Oak Ridge Natl Lab, Pacific NW Natl Lab, Univ Calif Santa Barbara, Amer Nucl Soc, Min Met & Mat Soc ID INSTABILITIES AB Loss of plasma confinement causes surface and structural damage to plasma-facing materials (PFMs) and remains a major obstacle for tokamak reactors. The deposited plasma energy results in surface erosion and structural failure. The surface erosion consists of vaporization, spallation, and liquid splatter of metallic materials, while the structural damage includes large temperature increases in structural materials and at the interfaces between surface coatings and structural members. Comprehensive models (contained in the HEIGHTS computer simulation package) are being used self-consistently to evaluate material damage. Splashing mechanisms occur as a result of volume bubble boiling and liquid hydrodynamic instabilities and brittle destruction mechanisms of nonmelting materials. The effect of macroscopic erosion on total mass losses and lifetime is evaluated. The macroscopic erosion products may further protect PFMs from severe erosion (via the droplet-shielding effect) in a manner similar to that of the vapor-shielding concept. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Argonne Natl Lab, Argonne, IL 60439 USA. Troitsk Inst Innovat & Fus Res, Troitsk, Russia. RP Hassanein, A (reprint author), Argonne Natl Lab, Bldg 362,9700 S Cass Ave, Argonne, IL 60439 USA. EM hassanein@anl.gov NR 15 TC 3 Z9 3 U1 0 U2 4 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 DEC PY 2000 VL 283 BP 1171 EP 1176 DI 10.1016/S0022-3115(00)00142-2 PN B PG 6 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA 383HV UT WOS:000165877800090 ER PT J AU Reed, CB Natesan, K Xu, Z Smith, DL AF Reed, CB Natesan, K Xu, Z Smith, DL TI The effect of laser welding process parameters on the mechanical and microstructural properties of V-4Cr-4Ti structural materials SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT 9th International Conference on Fusion Reactor Materials (ICFRM-9) CY OCT 10-15, 1999 CL COLORADO SPRINGS, COLORADO SP US DOE, Off Fus Energy Sci, Argoone Natl Lab, Oak Ridge Natl Lab, Pacific NW Natl Lab, Univ Calif Santa Barbara, Amer Nucl Soc, Min Met & Mat Soc AB This paper reports a systematic study which examined the use of a pulsed Nd:YAG laser to weld sheet materials of V-Cr-Ti alloys and to characterize the microstructural and mechanical properties of the resulting joints. Deep penetration, defect-free, and oxygen contamination free welds were achieved under an optimum combination of laser parameters including focal length of lens, pulse energy, pulse repetition rate, beam travel speed, and an innovative shielding gas arrangement. The key for defect-free welds was found to be the stabilization of the keyhole and providing an escape path for the gas trapped in the molten weld pool. Oxygen and nitrogen uptakes were reduced to levels only a few ppm higher than the starting material by design and development of an environmental control box (ECB). Laser-applied post-weld heat treatments showed that five-passes of a diffuse laser beam over the welded region softened the weld material, especially in the root region. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Argonne Natl Lab, Fus Power Program, Argonne, IL 60439 USA. RP Reed, CB (reprint author), Argonne Natl Lab, Fus Power Program, 9700 S Cass Ave, Argonne, IL 60439 USA. NR 4 TC 8 Z9 12 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 DEC PY 2000 VL 283 BP 1206 EP 1209 DI 10.1016/S0022-3115(00)00348-2 PN B PG 4 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA 383HV UT WOS:000165877800097 ER PT J AU Steward, RV Grossbeck, ML Chin, BA Aglan, HA Gan, Y AF Steward, RV Grossbeck, ML Chin, BA Aglan, HA Gan, Y TI Furnace brazing type 304 stainless steel to vanadium alloy (V-5Cr-5Ti) SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT 9th International Conference on Fusion Reactor Materials (ICFRM-9) CY OCT 10-15, 1999 CL COLORADO SPRINGS, COLORADO SP US DOE, Off Fus Energy Sci, Argoone Natl Lab, Oak Ridge Natl Lab, Pacific NW Natl Lab, Univ Calif Santa Barbara, Amer Nucl Soc, Min Met & Mat Soc AB In this investigation, pure copper was joined to type 304 stainless steel and V-5Cr-5Ti by brazing in a high vacuum furnace. Microstructural changes in the brazed region and surrounding substrates were examined as a function of holding time at temperatures of 20 degreesC, 40 degreesC and 60 degreesC above the melting point of copper. Reaction layers, which were extremely brittle, formed between the Cu and V-5Cr-5Ti substrates. The formation of intermetallic phases at the filler metal/substrate interfaces was evaluated. Additionally, precipitates (FeCu2 and FeCu18) formed in the Cu rich filler region. For temperatures greater than or equal to 60 degreesC above the melting point of Cu, extensive transverse cracking was observed. Hardness tests substantiated the hypothesis that the Cu/V-5Cr-5Ti reaction layer was extremely brittle, since micro-cracks propagated from the tips of the diamond-shaped indentations. Results of mechanical properties tests of the brazed material are also presented. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Auburn Univ, Ctr Mat Res, Auburn, AL 36849 USA. Oak Ridge Natl Lab, Oak Ridge, TN USA. Tuskegee Univ, Tuskegee, AL 36088 USA. RP Steward, RV (reprint author), 1000 ASU Dr 1317, Alcorn State, MS 39096 USA. NR 8 TC 8 Z9 12 U1 0 U2 5 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3115 J9 J NUCL MATER JI J. Nucl. Mater. PD DEC PY 2000 VL 283 BP 1224 EP 1228 DI 10.1016/S0022-3115(00)00390-1 PN B PG 5 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA 383HV UT WOS:000165877800101 ER PT J AU Xu, Q Edwards, DJ Yoshiie, T AF Xu, Q Edwards, DJ Yoshiie, T TI Effects of heat treatments on microstructure changes in the interface of Cu/SS316L joint materials SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT 9th International Conference on Fusion Reactor Materials (ICFRM-9) CY OCT 10-15, 1999 CL COLORADO SPRINGS, COLORADO SP US DOE, Off Fus Energy Sci, Argoone Natl Lab, Oak Ridge Natl Lab, Pacific NW Natl Lab, Univ Calif Santa Barbara, Amer Nucl Soc, Min Met & Mat Soc AB Precipitation and dispersion strengthened copper alloys joined with 316L austenitic stainless steel are expected to be heat sink materials in the first wall and divertor of International Thermonuclear Experimental Reactor (ITER) owing to the good thermal conductivity of Cu alloys. In the present study, the effects of heat treatment on microstructural stability in the interface of CuNiBe/SS316L and CuAl25/SS316L have been investigated. In the as-received CuNiBe/SS316L joints, voids were observed at the interface, and in the stainless steel side near the interface. But in the CuAl25/SS316L joints, voids were observed only in the Cu side near the interface. These voids would have a significant effect on the mechanical properties of joints. The results of annealing experiments showed that the microstructures in the interface of both types of joints were thermally stable during annealing at 573 and 673 K for 100 h. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Kyoto Univ, Inst Res Reactor, Osaka 5900494, Japan. Pacific NW Natl Lab, Richland, WA 99352 USA. RP Xu, Q (reprint author), Kyoto Univ, Inst Res Reactor, Osaka 5900494, Japan. NR 7 TC 4 Z9 5 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3115 J9 J NUCL MATER JI J. Nucl. Mater. PD DEC PY 2000 VL 283 BP 1229 EP 1233 DI 10.1016/S0022-3115(00)00175-6 PN B PG 5 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA 383HV UT WOS:000165877800102 ER PT J AU Barabash, V Akiba, M Cardella, A Mazul, I Odegard, BC Plochl, L Tivey, R Vieider, G AF Barabash, V Akiba, M Cardella, A Mazul, I Odegard, BC Plochl, L Tivey, R Vieider, G TI Armor and heat sink materials joining technologies development for ITER plasma facing components SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT 9th International Conference on Fusion Reactor Materials (ICFRM-9) CY OCT 10-15, 1999 CL COLORADO SPRINGS, COLORADO SP US DOE, Off Fus Energy Sci, Argoone Natl Lab, Oak Ridge Natl Lab, Pacific NW Natl Lab, Univ Calif Santa Barbara, Amer Nucl Soc, Min Met & Mat Soc AB An extensive program on the development of the joining technologies between armor (beryllium, tungsten and carbon fibre composites) and copper alloys heat sink materials for ITER plasma facing components (PFCs) has been carried out by ITER home teams. A brief review of this R&D program is presented in this paper. The critical problems related to these joints are described. Based on the results of this program and new requirements on the reduction the manufacturing cost of ITER PFC, reference technologies for use in ITER have been selected and recommended for further development. (C) 2000 Elsevier Science B.V. All rights reserved. C1 ITER Garching Joint Work Site, D-85748 Garching, Germany. Japan Atom Energy Res Inst, Naka, Ibaraki 31101, Japan. DV Efremov Inst Electrophys Apparatus, St Petersburg 189631, Russia. Sandia Natl Labs, Albuquerque, NM 87185 USA. Plansee AG, A-6600 Reutte, Austria. EFDA Close Support Unit, D-85748 Garching, Germany. RP Barabash, V (reprint author), ITER Garching Joint Work Site, Boltsmannstr 2, D-85748 Garching, Germany. NR 38 TC 44 Z9 57 U1 2 U2 10 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 DEC PY 2000 VL 283 BP 1248 EP 1252 DI 10.1016/S0022-3115(00)00120-3 PN B PG 5 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA 383HV UT WOS:000165877800106 ER PT J AU Cadden, CH Odegard, BC AF Cadden, CH Odegard, BC TI Refractory metal joining for first wall applications SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT 9th International Conference on Fusion Reactor Materials (ICFRM-9) CY OCT 10-15, 1999 CL COLORADO SPRINGS, COLORADO SP US DOE, Off Fus Energy Sci, Argoone Natl Lab, Oak Ridge Natl Lab, Pacific NW Natl Lab, Univ Calif Santa Barbara, Amer Nucl Soc, Min Met & Mat Soc AB The potential use of high temperature coolant (e.g. 900 degreesC He) in first wall structures would preclude the applicability of copper alloy heat sink materials and refractory metals would be potential replacements. Brazing trials were conducted in order to examine techniques to join tungsten armor to high tungsten (90-95 wt%) or molybdenum TZM heat sink materials. Palladium-, nickel- and zirconium-based filler metals were investigated using brazing temperatures ranging from 1000 degreesC to 1275 degreesC. Palladium-nickel and palladium-cobalt braze alloys were successful in producing generally sound metallurgical joints in tungsten alloy/tungsten couples, although there was an observed tendency for the pure tungsten armor material to exhibit grain boundary cracking after bonding. The zirconium- and nickel-based filler metals produced defect-containing joints, specifically cracking and porosity, respectively. The palladium-nickel braze alloy produced sound joints in the Mo TZM/tungsten couple. :Substitution of a lanthanum oxide-containing, fine-grained tungsten material (for the pure tungsten) eliminated the observed tungsten grain boundary cracking. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Sandia Natl Labs, Livermore, CA 94551 USA. RP Cadden, CH (reprint author), Sandia Natl Labs, POB 969,MS9402, Livermore, CA 94551 USA. NR 7 TC 21 Z9 21 U1 1 U2 6 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3115 J9 J NUCL MATER JI J. Nucl. Mater. PD DEC PY 2000 VL 283 BP 1253 EP 1257 DI 10.1016/S0022-3115(00)00178-1 PN B PG 5 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA 383HV UT WOS:000165877800107 ER PT J AU Lewinsohn, CA Singh, M Shibayama, T Hinoki, T Ando, M Katoh, Y Kohyama, A AF Lewinsohn, CA Singh, M Shibayama, T Hinoki, T Ando, M Katoh, Y Kohyama, A TI Joining of silicon carbide composites for fusion energy applications SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT 9th International Conference on Fusion Reactor Materials (ICFRM-9) CY OCT 10-15, 1999 CL COLORADO SPRINGS, COLORADO SP US DOE, Off Fus Energy Sci, Argoone Natl Lab, Oak Ridge Natl Lab, Pacific NW Natl Lab, Univ Calif Santa Barbara, Amer Nucl Soc, Min Met & Mat Soc ID CERAMICS AB Joining of silicon carbide based materials has been recognized as one of the enabling technologies for the successful utilization of ceramic components in fusion energy systems. Sintered silicon carbide (Hexoloy SA) and silicon carbide (Hi-Nicalon(TM)) fiber reinforced silicon carbide matrix composites have been joined using reaction forming/bonding based joining technologies. The room- and high-temperature mechanical properties and fractography of ceramic joints have been reported. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Pacific NW Natl Lab, MSIN, Richland, WA 99352 USA. NASA, Glen Res Ctr, Cleveland, OH 44135 USA. Hokkaido Univ, Ctr Adv Res Energy Technol, Sapporo, Hokkaido, Japan. Kyoto Univ, Inst Adv Energy, Uji, Kyoto 611, Japan. RP Lewinsohn, CA (reprint author), Pacific NW Natl Lab, MSIN, P8-15,POB 999, Richland, WA 99352 USA. RI Shibayama, Tamaki/F-7586-2012; OI Katoh, Yutai/0000-0001-9494-5862 NR 13 TC 28 Z9 29 U1 1 U2 10 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 DEC PY 2000 VL 283 BP 1258 EP 1261 DI 10.1016/S0022-3115(00)00247-6 PN B PG 4 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA 383HV UT WOS:000165877800108 ER PT J AU Natesan, K Uz, M Wieder, S AF Natesan, K Uz, M Wieder, S TI Development of electrically insulating coatings for service in a lithium environment SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT 9th International Conference on Fusion Reactor Materials (ICFRM-9) CY OCT 10-15, 1999 CL COLORADO SPRINGS, COLORADO SP US DOE, Off Fus Energy Sci, Argoone Natl Lab, Oak Ridge Natl Lab, Pacific NW Natl Lab, Univ Calif Santa Barbara, Amer Nucl Soc, Min Met & Mat Soc AB Several experiments were conducted to develop electrically insulating CaO coatings on a V-4Cr-4Ti alloy for application in a Li environment. The coatings were developed by vapor-phase transport external to Li, and also in situ in a Li-Ca environment at elevated temperature. In the vapor-phase study, several geometrical arrangements were examined to obtain a uniform coating of Ca on the specimens, which were typically coupons measuring 5 to 10 x 5 x 1 mm(3). After Ca deposition from the vapor phase, the specimens were oxidized in a high-purity argon environment at 600 degreesC to convert the deposited metal into oxide. The specimens exhibited insulating characteristics after this oxidation step. Several promising coated specimens were then exposed to high-purity Li at 500 degreesC for 48-68 h to determine coating integrity. Microstructural characteristics of the coatings were evaluated by scanning electron microscopy (SEM) and energy-dispersive X-ray (EDX) analysis. Electrical resistances of the coatings were measured by a two-probe method between room temperature and 700 degreesC before and after exposure to Li. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Argonne Natl Lab, Div Energy Technol, Argonne, IL 60439 USA. RP Natesan, K (reprint author), Argonne Natl Lab, Div Energy Technol, ET-212,9700 S Cass Ave, Argonne, IL 60439 USA. NR 6 TC 7 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 DEC PY 2000 VL 283 BP 1277 EP 1281 DI 10.1016/S0022-3115(00)00294-4 PN B PG 5 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA 383HV UT WOS:000165877800112 ER PT J AU Hoelzer, DT Pint, BA Wright, IG AF Hoelzer, DT Pint, BA Wright, IG TI A microstructural study of the oxide scale formation on ODS Fe-13Cr steel SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT 9th International Conference on Fusion Reactor Materials (ICFRM-9) CY OCT 10-15, 1999 CL COLORADO SPRINGS, COLORADO SP US DOE, Off Fus Energy Sci, Argoone Natl Lab, Oak Ridge Natl Lab, Pacific NW Natl Lab, Univ Calif Santa Barbara, Amer Nucl Soc, Min Met & Mat Soc ID STAINLESS-STEEL; OXIDATION AB The high-temperature oxidation behavior of a Y2O3-dispersed Fe-13Cr steel was investigated in air at temperatures of 700 degreesC, 800 degreesC, and 900 degreesC for 10 000 h. The kinetic data showed that oxide scale formation obeyed a parabolic rate law at each temperature and that the oxidation rate was lower than in other studies based on shorter test times. Microstructural analysis of the oxide scales formed at 700 degreesC and 800 degreesC was conducted using cross-sectional specimens and analytical electron microscopy (AEM). This analysis showed that the main scale was a continuous Cr-oxide and that an underlying amorphous silica layer formed at both temperatures, despite the low Si content (0.05 wt%) in the alloy. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Hoelzer, DT (reprint author), Oak Ridge Natl Lab, POB 2008,Bldg 5500, Oak Ridge, TN 37831 USA. RI Pint, Bruce/A-8435-2008; Hoelzer, David/L-1558-2016 OI Pint, Bruce/0000-0002-9165-3335; NR 10 TC 31 Z9 34 U1 0 U2 11 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 DEC PY 2000 VL 283 BP 1306 EP 1310 DI 10.1016/S0022-3115(00)00248-8 PN B PG 5 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA 383HV UT WOS:000165877800118 ER PT J AU Natesan, K Soppet, WK AF Natesan, K Soppet, WK TI Performance of V-Cr-Ti alloys in a hydrogen environment SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT 9th International Conference on Fusion Reactor Materials (ICFRM-9) CY OCT 10-15, 1999 CL COLORADO SPRINGS, COLORADO SP US DOE, Off Fus Energy Sci, Argoone Natl Lab, Oak Ridge Natl Lab, Pacific NW Natl Lab, Univ Calif Santa Barbara, Amer Nucl Soc, Min Met & Mat Soc AB A systematic study is underway at Argonne National Laboratory to evaluate the mechanical properties of several V-Cr-Ti alloys after exposure to environments containing hydrogen at various partial pressures (pH(2)). The goal is to correlate the chemistry of the exposure environment with hydrogen uptake by the samples and with the resulting influence on microstructures and tensile properties of the alloys. Other variables examined are specimen cooling rate and synergistic effects, if any, of oxygen and hydrogen on tensile behavior of the alloys. Experiments were conducted to evaluate the effect of pH(2) in the range of 3 x 10(-6) and 1 Torr on tensile properties of two V-Cr-Ti alloys. Up to pH(2) of 0.05 Torr, negligible effect of H was observed on either maximum engineering stress or uniform and total elongation. However, uniform and total elongation decreased substantially when the alloys were exposed at 500 degreesC to 1.0 Torr of H-2 pressure. Preliminary data from sequential exposures of the materials to low-pO(2) and several low-pH(2) environments did not reveal adverse effects on the maximum engineering stress or on uniform and total elongation when the alloy contained approximate to 2000 wppm O and 16 wppm H. Furthermore, tests in H-2-exposed specimens, initially annealed at various temperatures, showed that grain-size variation by a factor of approximate to2 had little or no effect on tensile properties. Also, specimen cooling rate had a small effect, if any, on the tensile properties of the alloy. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Argonne Natl Lab, Div Energy Technol, Argonne, IL 60439 USA. RP Natesan, K (reprint author), Argonne Natl Lab, Div Energy Technol, 9700 S Cass Ave,ET-212, Argonne, IL 60439 USA. NR 6 TC 12 Z9 15 U1 2 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 DEC PY 2000 VL 283 BP 1316 EP 1321 DI 10.1016/S0022-3115(00)00321-4 PN B PG 6 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA 383HV UT WOS:000165877800120 ER PT J AU Grossbeck, ML King, JF Hoelzer, DT AF Grossbeck, ML King, JF Hoelzer, DT TI Impurity effects on gas tungsten arc welds in V-Cr-Ti alloys SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT 9th International Conference on Fusion Reactor Materials (ICFRM-9) CY OCT 10-15, 1999 CL COLORADO SPRINGS, COLORADO SP US DOE, Off Fus Energy Sci, Argoone Natl Lab, Oak Ridge Natl Lab, Pacific NW Natl Lab, Univ Calif Santa Barbara, Amer Nucl Soc, Min Met & Mat Soc AB Plates 6.4 mm thick of V-Cr-Ti alloys, mostly V-4Cr-4Ti, were welded in a glove box argon atmosphere. A hot titanium getter led to excessive hydrogen concentrations. A cold zirconium-aluminum getter was used to reduce both oxygen and hydrogen. It was observed that a major source of hydrogen was dissociation of water vapor by the electric are of the welding torch. Careful monitoring of atmospheric impurities and successive pumping and backfilling cycles permitted welds of higher quality than previously achieved. Welds were evaluated primarily by the Charpy impact test. A ductile-to-brittle transition temperature (DBTT) of -28 degreesC was achieved in V-4Cr-4Ti. Previous GTA welds in the same material seldom had a DBTT below room temperature. Electron beam welding can achieve a DBTT of below -90 degreesC in the V-4Cr-4Ti alloy, indicating a lower limit to the DBTT by impurity control. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Oak Ridge Natl Lab, Met & Ceram Div, Oak Ridge, TN 37831 USA. RP Grossbeck, ML (reprint author), Oak Ridge Natl Lab, Met & Ceram Div, Bldg 5500,MS 6376,POB 2008, Oak Ridge, TN 37831 USA. RI Hoelzer, David/L-1558-2016 NR 19 TC 6 Z9 7 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 DEC PY 2000 VL 283 BP 1356 EP 1360 DI 10.1016/S0022-3115(00)00297-X PN B PG 5 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA 383HV UT WOS:000165877800128 ER PT J AU Gohar, Y Smith, DL AF Gohar, Y Smith, DL TI Multiplier, moderator, and reflector materials for advanced lithium-vanadium fusion blankets SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT 9th International Conference on Fusion Reactor Materials (ICFRM-9) CY OCT 10-15, 1999 CL COLORADO SPRINGS, COLORADO SP US DOE, Off Fus Energy Sci, Argoone Natl Lab, Oak Ridge Natl Lab, Pacific NW Natl Lab, Univ Calif Santa Barbara, Amer Nucl Soc, Min Met & Mat Soc AB The self-cooled lithium-vanadium fusion blanket concept has several attractive operational and environmental features. In this concept, liquid lithium works as the tritium breeder and coolant to alleviate issues of coolant breeder compatibility and reactivity. Vanadium alloy (V-4Cr-Ti) is used as the structural material because of its superior performance relative to other alloys for this application. However, this concept has poor attenuation characteristics and energy multiplication for the DT neutrons. An advanced self-cooled lithium-vanadium fusion blanket concept has been developed to eliminate these drawbacks while maintaining all the attractive features of the conventional concept. An electrical insulator coating for the coolant channels, spectral shifter (multiplier, and moderator) and reflector were utilized in the blanket design to enhance the blanket performance. In addition, the blanket was designed to have the capability to operate at average loading conditions of 2 MW/m(2) surface heat flux and 10 MW/m(2)? neutron wall loading. This paper assesses the spectral shifter and the reflector materials and it defines the technological requirements of this advanced blanket concept. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Argonne Natl Lab, Fus Power Program, Argonne, IL 60439 USA. RP Gohar, Y (reprint author), Argonne Natl Lab, Fus Power Program, 9700 S Cass Ave, Argonne, IL 60439 USA. NR 8 TC 2 Z9 2 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3115 J9 J NUCL MATER JI J. Nucl. Mater. PD DEC PY 2000 VL 283 BP 1370 EP 1374 DI 10.1016/S0022-3115(00)00123-9 PN B PG 5 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA 383HV UT WOS:000165877800131 ER PT J AU Petti, DA Smolik, GR Anderl, RA AF Petti, DA Smolik, GR Anderl, RA TI On the mechanisms associated with the chemical reactivity of Be in steam SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT 9th International Conference on Fusion Reactor Materials (ICFRM-9) CY OCT 10-15, 1999 CL COLORADO SPRINGS, COLORADO SP US DOE, Off Fus Energy Sci, Argoone Natl Lab, Oak Ridge Natl Lab, Pacific NW Natl Lab, Univ Calif Santa Barbara, Amer Nucl Soc, Min Met & Mat Soc ID BERYLLIUM; DEUTERIUM AB One safety concern surrounding beryllium as a plasma-facing material in a water-cooled Tokamak is steam interactions with hot beryllium and the production of significant quantities of hydrogen. We have tested several different product forms of Be with different densities and levels of porosity. Oxidation kinetics has been determined by measurements of hydrogen release with a mass spectrometer, volumetric measurements of the product gas and weight change of the sample. We discuss and compare with the literature the fundamental mechanisms and kinetics controlling the oxidation of Be in steam. Fully dense beryllium exhibits parabolic, linear and accelerating modes of oxidation as temperature increases from 450 degreesC to 1200 degreesC. The oxidation mechanisms and temperature trends are similar for other product forms. Oxidation rates are higher, however, when processing or annealing significantly increases the extent of interconnected porosity and consequently the effective surface area. The effective surface area as measured by BET surface analyses is a key parameter when comparing oxidation rates. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Idaho Natl Engn & Environm Lab, Fus Safety Program, Idaho Falls, ID 83415 USA. RP Petti, DA (reprint author), Idaho Natl Engn & Environm Lab, Fus Safety Program, POB 1625, Idaho Falls, ID 83415 USA. NR 23 TC 21 Z9 22 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 DEC PY 2000 VL 283 BP 1390 EP 1395 DI 10.1016/S0022-3115(00)00299-3 PN B PG 6 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA 383HV UT WOS:000165877800135 ER PT J AU Majumdar, S Kalinin, G AF Majumdar, S Kalinin, G TI ITER structural design criteria and their extension to advanced reactor blankets SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT 9th International Conference on Fusion Reactor Materials (ICFRM-9) CY OCT 10-15, 1999 CL COLORADO SPRINGS, COLORADO SP US DOE, Off Fus Energy Sci, Argoone Natl Lab, Oak Ridge Natl Lab, Pacific NW Natl Lab, Univ Calif Santa Barbara, Amer Nucl Soc, Min Met & Mat Soc AB Applications of the recent ITER structural design criteria (ISDC) are illustrated by two components. First, the low-temperature-design rules are applied to copper alloys that are particularly prone to irradiation embrittlement at relatively low fluences at certain temperatures. Allowable stresses are derived and the impact of the embrittlement on allowable surface heat flux of a simple first-wall/limiter design is demonstrated. Next, the high-temperature-design rules of ISDC are applied to evaporation of lithium and vapor extraction (EVOLVE), a blanket design concept currently being investigated under the US Advanced Power Extraction (APEX) program. A single tungsten first-wall tube is considered for thermal and stress analyses by finite-element method. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Argonne Natl Lab, Fus Power Program, Argonne, IL 60439 USA. Max Planck Inst Plasmaphys, ITER Garching JWS, D-85748 Garching, Germany. RP Majumdar, S (reprint author), Argonne Natl Lab, Fus Power Program, 9700 S Cass Ave, Argonne, IL 60439 USA. NR 4 TC 17 Z9 17 U1 0 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3115 J9 J NUCL MATER JI J. Nucl. Mater. PD DEC PY 2000 VL 283 BP 1424 EP 1428 DI 10.1016/S0022-3115(00)00324-X PN B PG 5 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA 383HV UT WOS:000165877800142 ER PT J AU Greenwood, LR Oliver, BM Ohnuki, S Shiba, K Kohno, Y Kohyama, A Robertson, JP Meadows, JW Gelles, DS AF Greenwood, LR Oliver, BM Ohnuki, S Shiba, K Kohno, Y Kohyama, A Robertson, JP Meadows, JW Gelles, DS TI Accelerated helium and hydrogen production in Fe-54 doped alloys - measurements and calculations for the FIST experiment SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT 9th International Conference on Fusion Reactor Materials (ICFRM-9) CY OCT 10-15, 1999 CL COLORADO SPRINGS, COLORADO SP US DOE, Off Fus Energy Sci, Argoone Natl Lab, Oak Ridge Natl Lab, Pacific NW Natl Lab, Univ Calif Santa Barbara, Amer Nucl Soc, Min Met & Mat Soc AB F-82H alloys isotopically enriched in Fe-54 up to 86% were irradiated in the high Aux isotope reactor (HFIR) to determine the accelerated production of helium and hydrogen due to isotopic effects. Results are compared to calculations using isotopic helium production cross-sections from ENDF/B-VI or GNASH and measured neutron spectra. Helium measurements demonstrated an accelerated helium (appm)/dpa ratio of 2.3 after a 1.25-year irradiation, an increase of a factor of 4.3 over natural iron. The accelerated helium production is due to higher helium production cross-sections for Fe-54 and Fe-55. Alloys doped with Fe-55 could achieve helium/dpa ratios up to about 20, well above the fusion reactor ratio of 10. Hydrogen measurements were performed using a newly developed quadrupole mass spectrometer system at PNNL. Calculations predict that hydrogen production will be accelerated by about a factor of 13 over natural iron. However, measurements show that most of this hydrogen is not retained in the samples. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Pacific NW Natl Lab, Richland, WA 99352 USA. Hokkaido Univ, Fac Engn, Sapporo, Hokkaido 060, Japan. Japan Atom Energy Res Inst, Naka, Ibaraki 31911, Japan. Univ Tokyo, Dept Mat Sci, Bunkyo Ku, Tokyo 113, Japan. Kyoto Univ, Inst Adv Energy, Uji 611, Japan. Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. Argonne Natl Lab, Argonne, IL 60439 USA. RP Greenwood, LR (reprint author), Pacific NW Natl Lab, POB 999, Richland, WA 99352 USA. RI Greenwood, Lawrence/H-9539-2016 OI Greenwood, Lawrence/0000-0001-6563-0650 NR 8 TC 14 Z9 14 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 DEC PY 2000 VL 283 BP 1438 EP 1442 DI 10.1016/S0022-3115(00)00301-9 PN B PG 5 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA 383HV UT WOS:000165877800145 ER PT J AU Maekawa, F Verzilov, YM Smith, DL Ikeda, Y AF Maekawa, F Verzilov, YM Smith, DL Ikeda, Y TI Experimental study on beryllium-7 production via sequential reactions in lithium-containing compounds irradiated by 14 MeV neutrons SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT 9th International Conference on Fusion Reactor Materials (ICFRM-9) CY OCT 10-15, 1999 CL COLORADO SPRINGS, COLORADO SP US DOE, Off Fus Energy Sci, Argoone Natl Lab, Oak Ridge Natl Lab, Pacific NW Natl Lab, Univ Calif Santa Barbara, Amer Nucl Soc, Min Met & Mat Soc AB Except for H-3 and C-14, no radioactive nuclide is produced by neutron-induced reactions with lithium in lithium-containing materials such as Li2O and Li2CO3. However, when the lithium-containing materials are irradiated by 14 MeV neutrons, radioactive Be-7 is produced by sequential charged particle reactions (SCPR). In this study, we measured effective Be-7 production cross-sections in several lithium-containing samples at 14 MeV: the cross-sections are in the order of mub. Estimation of the effective cross-sections is attempted, and the estimated values agreed well with the experimental data. It was shown that the Be-7 activity in a unit volume of lithium-containing materials in D-T fusion reactors can exceed total activity of the same unit volume of the SiC structural material in a certain cooling time. Consequently, a careful consideration of the Be-7 production by SCPR is required to assess radioactive inventories in lithium-containing D-T fusion blanket materials. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Japan Atom Energy Res Inst, Fus Neutron Lab, Tokai, Ibaraki 31911, Japan. Moscow Engn Phys Inst, Moscow 115409, Russia. Argonne Natl Lab, Argonne, IL 60439 USA. RP Maekawa, F (reprint author), Japan Atom Energy Res Inst, Fus Neutron Lab, Tokai, Ibaraki 31911, Japan. NR 12 TC 5 Z9 5 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3115 J9 J NUCL MATER JI J. Nucl. Mater. PD DEC PY 2000 VL 283 BP 1448 EP 1452 DI 10.1016/S0022-3115(00)00182-3 PN B PG 5 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA 383HV UT WOS:000165877800147 ER PT J AU Smolik, GR Petti, DA Schuetz, ST AF Smolik, GR Petti, DA Schuetz, ST TI Oxidation and volatilization of TZM alloy in air SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT 9th International Conference on Fusion Reactor Materials (ICFRM-9) CY OCT 10-15, 1999 CL COLORADO SPRINGS, COLORADO SP US DOE, Off Fus Energy Sci, Argoone Natl Lab, Oak Ridge Natl Lab, Pacific NW Natl Lab, Univ Calif Santa Barbara, Amer Nucl Soc, Min Met & Mat Soc AB The excellent high temperature strength and thermal conductivity of molybdenum-base alloys provide attractive features for components in advanced magnetic and inertial fusion devices. Refractory metal-base alloys react readily with oxygen and other gases, and molybdenum alloys are susceptible to losses from highly volatile molybdenum trioxide (MoO3) species. Transport of radioactivity by the volatilization, migration and re-depssition of MoO3 during a potential accident involving a loss of vacuum or inert environment represents a safety issue. We have experimentally measured the oxidation, volatilization and re-deposition of molybdenum from TZM in flowing air between 400 degreesC and 800 degreesC. Calculations using chemical thermodynamic data for vapor pressures over pure MoO3 and a vaporization mass transfer model correlate well with the experimental data between 600 degreesC and 800 degreesC. Partial saturation of(MoO3) gas species accounts for influences of flow rate at 700 degreesC. Some anomalies in oxidation rate below 650 degreesC suggest that other phases, e.g., MoO2 or other non-stoichiometric oxides may influence oxidation and volatilization processes under some limited conditions. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Lockheed Martin Idaho Technol Co Inc, Idaho Natl Engn & Environm Lab, Idaho Falls, ID 83415 USA. RP Smolik, GR (reprint author), Lockheed Martin Idaho Technol Co Inc, Idaho Natl Engn & Environm Lab, POB 1625, Idaho Falls, ID 83415 USA. NR 9 TC 44 Z9 54 U1 3 U2 15 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 DEC PY 2000 VL 283 BP 1458 EP 1462 DI 10.1016/S0022-3115(00)00303-2 PN B PG 5 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA 383HV UT WOS:000165877800149 ER PT J AU Anderl, RA Scaffidi-Argentina, F Davydov, D Pawelko, RJ Smolik, GR AF Anderl, RA Scaffidi-Argentina, F Davydov, D Pawelko, RJ Smolik, GR TI Steam chemical reactivity of Be pebbles and Be powder SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT 9th International Conference on Fusion Reactor Materials (ICFRM-9) CY OCT 10-15, 1999 CL COLORADO SPRINGS, COLORADO SP US DOE, Off Fus Energy Sci, Argoone Natl Lab, Oak Ridge Natl Lab, Pacific NW Natl Lab, Univ Calif Santa Barbara, Amer Nucl Soc, Min Met & Mat Soc ID BERYLLIUM AB This paper reports the results of chemical reactivity experiments for Be pebbles (2 and 0.2 mm diameter) and Be powder (14-31 mum diameter) exposed to steam at elevated temperatures, 350-900 degreesC for pebbles and 400-500 degreesC for powders. We measured BET specific surface areas of 0.12 m(2)/g for 2 mm pebbles, 0.24 m(2)/g for 0.2 mm pebbles and 0.66-1.21 m(2)/g for Be powder samples. These experiments showed a complex reactivity behavior for the material, dependent primarily on the test temperature. Average H-2 generation rates for powder samples, based on measured BET surface areas, were in good agreement with previous measurements for fully dense consolidated powder metallurgy (CPM)-Be. Rates for the Be pebbles, based on measured BET surface areas, were systematically lower than the CPM-Be rates, possibly because of different surface and bulk features for the pebbles, especially surface layer impurities, that contribute to the measured BET surface area and influence the oxidation process at the material surface. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Lockheed Martin Idaho Techno Co, Idaho Natl Engn & Environm Lab, Idaho Falls, ID 83415 USA. Forschungszentrum Karlsruhe, Inst Neutronenphys & Reaktortech, D-76021 Karlsruhe, Germany. AA Bochvar Inorgan Mat Res Inst, VNIINM, Moscow, Russia. RP Anderl, RA (reprint author), Lockheed Martin Idaho Techno Co, Idaho Natl Engn & Environm Lab, POB 1625, Idaho Falls, ID 83415 USA. NR 12 TC 2 Z9 3 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3115 J9 J NUCL MATER JI J. Nucl. Mater. PD DEC PY 2000 VL 283 BP 1463 EP 1467 DI 10.1016/S0022-3115(00)00304-4 PN B PG 5 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA 383HV UT WOS:000165877800150 ER PT J AU Ebert, WL Wolf, SF AF Ebert, WL Wolf, SF TI An interlaboratory study of a standard glass for acceptance testing of low-activity waste glass SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article AB An interlaboratory study was conducted to determine the precision with which the composition and chemical durability of a borosilicate glass could be measured and to generate a data base of expected values for that glass. The study was conducted with a low-activity reference material (LRM) glass that was developed for use as a standard material for acceptance testing of immobilized low-activity waste (ILAW) products, including those to be made with Hanford tank wastes. The study provided nine independent measurements of the LRM glass composition and eight independent sets of triplicate product consistency tests (PCTs) at 40 degreesC and 90 degreesC. Statistical analysis of these data indicates that LRM glass is suitable for use as a composition and test standard. The results from this study can be used to evaluate the accuracy of composition analyses and PCTs conducted with LRM glass at other laboratories in conjunction with acceptance tests conducted with ILAW products. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Argonne Natl Lab, Div Chem Technol, Argonne, IL 60439 USA. RP Ebert, WL (reprint author), Argonne Natl Lab, Div Chem Technol, 9700 S Cass Ave, Argonne, IL 60439 USA. NR 11 TC 2 Z9 2 U1 0 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3115 J9 J NUCL MATER JI J. Nucl. Mater. PD DEC PY 2000 VL 282 IS 2-3 BP 112 EP 124 DI 10.1016/S0022-3115(00)00420-7 PG 13 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA 385VJ UT WOS:000166025300003 ER PT J AU Hunn, JD Lee, EH Byun, TS Mansur, LK AF Hunn, JD Lee, EH Byun, TS Mansur, LK TI Helium and hydrogen induced hardening in 316LN stainless steel SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article ID TRIPLE ION-BEAM; IRRADIATION; MIGRATION; NICKEL AB In certain radiation environments, such as the spallation neutron source (SNS) presently in design and construction, the high transmutation production rate for helium and hydrogen, concomitant with displacement damage, may affect the mechanical properties of structural materials. To better understand this effect, we have studied type 316LN stainless steel specimens implanted with medium energy Fe-, He-, and H-ions, alone and in combination. In this report, we present nanoindentation measurements of the incremental increase in hardness caused by 360 keV He-ions implanted at 200 degreesC to concentrations from 2 to 200 000 appm. The He-induced hardening was found to saturate at twice the level measured for Fe-induced displacement damage alone. The additional hardening at high helium concentrations was associated with the presence of helium filled cavities (bubbles), observed by transmission electron microscopy (TEM). We also found that co-injection of helium and hydrogen resulted in more hardening than was observed for He-implantation alone. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Oak Ridge Natl Lab, Div Met & Ceram, Oak Ridge, TN 37831 USA. RP Hunn, JD (reprint author), Oak Ridge Natl Lab, Div Met & Ceram, POB 2008, Oak Ridge, TN 37831 USA. NR 26 TC 68 Z9 72 U1 1 U2 42 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 DEC PY 2000 VL 282 IS 2-3 BP 131 EP 136 DI 10.1016/S0022-3115(00)00424-4 PG 6 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA 385VJ UT WOS:000166025300005 ER PT J AU Allen, TR Cole, JI Trybus, CL Porter, DL AF Allen, TR Cole, JI Trybus, CL Porter, DL TI The effects of long-time irradiation and thermal aging on 304 stainless steel SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article AB The effect of long-time irradiation and thermal aging on the tensile, fracture, and swelling properties of 304 stainless steel were studied. Samples of cold-worked and annealed 304 were irradiated in EBR-II at temperatures between 371-400 degreesC or thermally aged in the EBR-II primary core basket at 371 degreesC for times up to 18 years. Samples of annealed steel were irradiated in rows 4 and 12 of EBR-II to determine the effect of dose rate. No significant changes in tensile properties or density occurred in cold-worked thermally aged steel. For samples irradiated near 370 degreesC, decreasing the dose rate caused an increase in swelling and had no measurable effect on tensile properties. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Argonne Natl Lab, Idaho Falls, ID 83403 USA. RP Allen, TR (reprint author), Argonne Natl Lab, POB 2528, Idaho Falls, ID 83403 USA. OI Allen, Todd/0000-0002-2372-7259; Cole, James/0000-0003-1178-5846 NR 15 TC 2 Z9 2 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 DEC PY 2000 VL 282 IS 2-3 BP 171 EP 179 DI 10.1016/S0022-3115(00)00426-8 PG 9 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA 385VJ UT WOS:000166025300010 ER PT J AU Kolman, DG Griego, ME James, CA Butt, DP AF Kolman, DG Griego, ME James, CA Butt, DP TI Thermally induced gallium removal from plutonium dioxide for MOX fuel production SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article ID BEHAVIOR; OXIDE AB A dry process for separating Ga2O3 from PuO2 - 1 wt% Ga2O3 powder was developed. PuO2-Ga2O3 powder was exposed to flowing Ar-6% H-2 at 600-1200 degreesC. Under these conditions, Ga2O3 is reduced to Ga2O, a volatile species. Ga2O, which is stable in a reducing environment at temperatures greater than 800 degreesC, evolves and is collected downstream. Different process parameters were varied in an effort to optimize thermally induced gallium removal (TIGR). Exposure temperature had the greatest effect on TIGR. Temperatures of at least 1000 degreesC were required to obtain discernible TIGR. As little as 25 wppm Ga remained after processing PuO2 at 1200 degreesC. It is likely that a further reduction in retained Ga can be attained by increasing the processing temperature. Ga removal was shown to increase with process time. However, the benefit in processing beyond 4 h is limited for this system. The lack of effect of sample volume and gas flow rate on TIGR suggests that Ga removal is limited by mass transport within the powder particles. The fact that Ga removal is less efficient in more coarse PuO2 powders supports this hypothesis. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Univ Calif Los Alamos Natl Lab, Nucl Mat Technol Div, Mat Corros & Environm Effects Lab, Los Alamos, NM 87545 USA. RP Kolman, DG (reprint author), Univ Calif Los Alamos Natl Lab, Nucl Mat Technol Div, Mat Corros & Environm Effects Lab, MS-E530,POB 1663, Los Alamos, NM 87545 USA. RI Butt, Darryl/B-7480-2008 OI Butt, Darryl/0000-0003-4501-8864 NR 30 TC 11 Z9 11 U1 1 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3115 J9 J NUCL MATER JI J. Nucl. Mater. PD DEC PY 2000 VL 282 IS 2-3 BP 245 EP 254 DI 10.1016/S0022-3115(00)00397-4 PG 10 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA 385VJ UT WOS:000166025300019 ER PT J AU Bishayee, A Rao, DV Srivastava, SC Bouchet, LG Bolch, WE Howell, RW AF Bishayee, A Rao, DV Srivastava, SC Bouchet, LG Bolch, WE Howell, RW TI Marrow-sparing effects of Sn-117m(4+)diethylenetriaminepentaacetic acid for radionuclide therapy of bone cancer SO JOURNAL OF NUCLEAR MEDICINE LA English DT Article DE bone; pain; metastases; radionuclides; granulocyte-macrophage; colony-forming cells; chronic irradiation; dose-response; dosimetry; EGS4; P-32; P-33; Sn-117m; therapy ID OSSEOUS METASTASES; INVIVO BEHAVIOR; DOSE-RATE; PAIN; PALLIATION; RADIOPHARMACEUTICALS; SAMARIUM-153-EDTMP; DOSIMETRY; RADIATION; DISEASE AB Several bone-seeking radionuclides (P-32, Sr-89, Re-186, and Sm-153) have been used to treat bone pain. The limiting factor in this modality is marrow toxicity. Our hypothesis is that marrow toxicity can be reduced while maintaining therapeutic efficacy using radionuclides that emit short-range beta particles or conversion electrons (CEs). A recent study on 47 patients using the short-range CE emitter Sn-117m(4+)diethylenetriaminepentaacetic acid (117mSn(4+)DTPA) supports this hypothesis. The hypothesis is now tested using 117mSn(4+)DTPA in a mouse femur model. Methods: The survival of granulocyte-macrophage colony-forming cells (GM-CFCs) in femoral marrow is used as a biologic dosimeter for bone marrow. The dosimeter is calibrated by irradiating mice with exponentially decreasing dose rates of Cs-137 gamma -rays with a dose-rate decrease half-time, T-d, equal to the effective clearance half-time of Sn-117m(4+)DTPA from the femur (222 h). When T-d = 222 h, the mean absorbed dose required to achieve a survival fraction of 37% is 151 cGy. After calibration, (117)mSn(4+)DTPA is administered and GM-CFC survival is determined as a function of injected activity. These data are used to experimentally determine the mean absorbed dose to the femoral marrow per unit injected activity. The kinetics of radioactivity in the marrow, muscle, and femoral bone are also determined. Finally, a theoretic dosimetry model of the mouse femur is used, and the absorbed doses to the femoral marrow and bone are calculated. Results: The experimental mean absorbed dose to the femoral marrow per unit injected activity of Sn-117m(4+)DTPA is 0.043 cGy/kBq. The theoretic mean absorbed dose to the femoral bone per unit injected activity is 1.07 cGy/kBq. If these data are compared with those obtained previously for P-32-orthophosphate, the radiochemical (117)mSn(4+)DTPA yields up to an 8-fold therapeutic advantage over the energetic beta emitter P-32. Conclusion: The CE emitter 117mSn offers a large dosimetric advantage over energetic beta -particle emitters for alleviating bone pain, and possibly for other therapeutic applications, while minimizing marrow toxicity. C1 Univ Med & Dent New Jersey, New Jersey Med Sch, Dept Radiol, Div Radiat Res, Newark, NJ 07103 USA. Brookhaven Natl Lab, Dept Med, New York, NY USA. Univ Florida, Dept Nucl & Radiol Engn, Gainesville, FL USA. RP Howell, RW (reprint author), Univ Med & Dent New Jersey, New Jersey Med Sch, Dept Radiol, Div Radiat Res, MSB F-451,185 S Orange Ave, Newark, NJ 07103 USA. FU NCI NIH HHS [CA-54891] NR 39 TC 36 Z9 40 U1 0 U2 3 PU SOC NUCLEAR MEDICINE INC PI RESTON PA 1850 SAMUEL MORSE DR, RESTON, VA 20190-5316 USA SN 0161-5505 J9 J NUCL MED JI J. Nucl. Med. PD DEC PY 2000 VL 41 IS 12 BP 2043 EP 2050 PG 8 WC Radiology, Nuclear Medicine & Medical Imaging SC Radiology, Nuclear Medicine & Medical Imaging GA 386NG UT WOS:000166068000024 PM 11138691 ER PT J AU Tzeng, Y Tzeng, SYT Kuo, TTS Lee, TSH AF Tzeng, Y Tzeng, SYT Kuo, TTS Lee, TSH TI A local density approximation treatment for the Pauli exclusion operator in hypernuclei SO JOURNAL OF PHYSICS G-NUCLEAR AND PARTICLE PHYSICS LA English DT Article ID EXCHANGE-POTENTIAL APPROACH; BARYON-BARYON SCATTERING; NUCLEON; MATRIX; MODEL; SHELL AB An effort is made to simplify the complications of computing hyperon-nucleon G-matrix elements arising from the Pauli exclusion operator contained in the integral equation. We perform a two-frequency shell-model folded-diagram calculation on hypernuclei using two different treatments for the Pauli exclusion operator Q(2), namely, a local density approximation where Q(2) is replaced by a nuclear-matter Pauli operator (Q) over bar(rho), with rho being a density parameter, and an exact calculation where Q(2) is expressed in terms of shell-model wavefunctions. With a proper choice of rho, it is possible to reach a reasonable accuracy by using a local density approximation for the Pauli operator. For heavy hypernuclei, this (Q) over bar(rho) can be used to save a tremendous amount of computing time. C1 Acad Sinica, Inst Phys, Taipei, Taiwan. Natl Taipei Univ Technol, Taipei, Taiwan. SUNY Stony Brook, Dept Phys, Stony Brook, NY 11794 USA. Argonne Natl Lab, Div Phys, Argonne, IL 60493 USA. RP Tzeng, Y (reprint author), Acad Sinica, Inst Phys, Taipei, Taiwan. NR 28 TC 2 Z9 2 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 DEC PY 2000 VL 26 IS 12 BP 1765 EP 1774 DI 10.1088/0954-3899/26/12/301 PG 10 WC Physics, Nuclear; Physics, Particles & Fields SC Physics GA 385BE UT WOS:000165981100002 ER PT J AU Garcia, AL Wagner, W AF Garcia, AL Wagner, W TI The limiting kinetic equation of the Consistent Boltzmann Algorithm for dense gases SO JOURNAL OF STATISTICAL PHYSICS LA English DT Article DE kinetic theory; Enskog equation; direct simulation Monte Carlo; Boltzmann equation; consistent Boltzmann Algorithm; dense gases ID ENSKOG EQUATION; SIMULATION; MODELS; BIRD AB This paper establishes a theoretical foundation for the Consistent Boltzmann Algorithm (CBA) by deriving the limiting kinetic equation. The formulation is similar to the proof by one of the authors that the Boltzmann equation is the limiting kinetic equation for Direct Simulation Monte Carlo [W. Wagner, J. Statist. Phys. 66:1011 (1992)]. For a simplified model distilled from CBA, the limiting equation is solved numerically, and very good agreement with the predictions of the theory is found. C1 Univ Calif Lawrence Livermore Natl Lab, Inst Sci Comp Res, Livermore, CA 94550 USA. Weierstr Inst Appl Anal & Stoastics, D-10117 Berlin, Germany. San Jose State Univ, Dept Phys, San Jose, CA 95192 USA. RP Garcia, AL (reprint author), Univ Calif Lawrence Livermore Natl Lab, Inst Sci Comp Res, POB 5508, Livermore, CA 94550 USA. NR 17 TC 10 Z9 10 U1 0 U2 3 PU KLUWER ACADEMIC/PLENUM PUBL PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 0022-4715 J9 J STAT PHYS JI J. Stat. Phys. PD DEC PY 2000 VL 101 IS 5-6 BP 1065 EP 1086 DI 10.1023/A:1026429722169 PG 22 WC Physics, Mathematical SC Physics GA 385MP UT WOS:000166008500004 ER PT J AU Bastea, S Esposito, R Lebowitz, JL Marra, R AF Bastea, S Esposito, R Lebowitz, JL Marra, R TI Binary fluids with long range segregating interaction. I: Derivation of kinetic and hydrodynamic equations SO JOURNAL OF STATISTICAL PHYSICS LA English DT Article DE binary fluids; phase segregation; kinetic and hydrodynamic equations; long-range interactions ID STATIONARY BOLTZMANN-EQUATION; NAVIER-STOKES LIMIT; PHASE SEGREGATION; SPINODAL DECOMPOSITION; PARTICLE-SYSTEMS; DYNAMICS; SEPARATION; ALLOYS AB We study the evolution of a two component fluid consisting of "blue" and ''red" particles which interact via strong short range (hard core) and weak long range pair potentials. At low temperatures the equilibrium state of the system is one in which there are two coexisting phases. Under suitable choices of space-time scalings and system parameters we first obtain (formally) a mesoscopic kinetic Vlasov-Boltzmann equation for the one particle position and velocity distribution functions, appropriate for a description of the phase segregation kinetics in this system, Further scalings then yield Vlasov-Euler and incompressible Vlasov-Navier-Stokes equations. We also obtain, via the usual truncation of the Chapman-Enskog expansion, compressible Vlasov-Navier-Stokes equations. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. Univ Aquila, Dipartimento Matemat, I-67100 Laquila, Italy. Rutgers State Univ, Dept Math & Phys, New Brunswick, NJ 08903 USA. Univ Roma Tor Vergata, Dipartimento Fis, I-00133 Rome, Italy. Univ Roma Tor Vergata, Unita INFM, I-00133 Rome, Italy. RP Bastea, S (reprint author), Univ Calif Lawrence Livermore Natl Lab, POB 808, Livermore, CA 94550 USA. RI Marra, Rossana/K-7677-2015; OI Marra, Rossana/0000-0002-9577-0248; Esposito, Raffaele/0000-0003-1744-4161 NR 32 TC 28 Z9 28 U1 0 U2 5 PU KLUWER ACADEMIC/PLENUM PUBL PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 0022-4715 J9 J STAT PHYS JI J. Stat. Phys. PD DEC PY 2000 VL 101 IS 5-6 BP 1087 EP 1136 DI 10.1023/A:1026481706240 PG 50 WC Physics, Mathematical SC Physics GA 385MP UT WOS:000166008500005 ER PT J AU Bill, A Morawitz, H Kresin, VZ AF Bill, A Morawitz, H Kresin, VZ TI Low-energy electronic collective modes and superconductivity in layered systems SO JOURNAL OF SUPERCONDUCTIVITY LA English DT Article; Proceedings Paper CT International Conference on Major Trends in Superconductivity in the New Millennium CY MAR 31-APR 06, 2000 CL KLOSTERS, SWITZERLAND DE Coulomb interaction; low-energy electronic collective modes; phonon-plasmon scenarios ID PLASMONS; GAS AB The Coulomb interaction induces low-energy electronic collective modes (LEECM) in layered conductors. We study how the superconducting critical temperature T-c is affected by such collective modes within the strong-coupling theory of superconductivity. Whereas we account for both the electron-phonon and the screened Coulomb interactions, the main focus is set on the latter. The dielectric function is displayed and screening within RPA is discussed. We then show that LEECM affect the superconducting state constructively in layered structures. Their effect can be interpreted as a negative mu* in the Eliashberg theory. We examine in what respect the collective-mode scenario differs in layered conductors as compared to three-dimensional (3D) isotropic metals. C1 Paul Scherrer Inst, CH-5232 Villigen, Switzerland. IBM Corp, Almaden Res Ctr, San Jose, CA 95120 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Bill, A (reprint author), Paul Scherrer Inst, CH-5232 Villigen, Switzerland. NR 13 TC 4 Z9 4 U1 0 U2 1 PU KLUWER ACADEMIC/PLENUM PUBL PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 0896-1107 J9 J SUPERCOND JI J. Supercond. PD DEC PY 2000 VL 13 IS 6 BP 907 EP 909 DI 10.1023/A:1026478605060 PG 3 WC Physics, Applied; Physics, Condensed Matter SC Physics GA 378DD UT WOS:000165569000009 ER PT J AU Bonca, J Trugman, SA AF Bonca, J Trugman, SA TI Mobile bipolaron - Strong coupling approach SO JOURNAL OF SUPERCONDUCTIVITY LA English DT Article; Proceedings Paper CT International Conference on Major Trends in Superconductivity in the New Millennium CY MAR 31-APR 06, 2000 CL KLOSTERS, SWITZERLAND DE bipolaron; polaron; electron-phonon coupling; superconductivity ID POLARONS; MODEL AB We explore the properties of the bipolaron in a 1D Holstein-Hubbard model with dynamical quantum phonons. We apply strong coupling theory to investigate the intersite bipolaron. We investigate the influence of the Hubbard interaction on the bipolaron binding energy, effective mass, and phase diagram. We compare our analytic results to recent numerical calculations [1]. In the intermediate and strong coupling regimes, a bipolaron is stable beyond the naive stability limit U-0 = 2 omegag(2). The intersite bipolaron has a significantly reduced mass compared to the single site bipolaron, and is stable in the strong coupling regime up to U-c similar to 4 omegag(2). C1 Univ Ljubljana, FMF, Ljubljana 1000, Slovenia. Jozef Stefan Inst, Ljubljana 1000, Slovenia. Univ Calif Los Alamos Natl Lab, Div Theory, Los Alamos, NM 87545 USA. RP Bonca, J (reprint author), Univ Ljubljana, FMF, Ljubljana 1000, Slovenia. NR 19 TC 3 Z9 3 U1 0 U2 0 PU KLUWER ACADEMIC/PLENUM PUBL PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 0896-1107 J9 J SUPERCOND JI J. Supercond. PD DEC PY 2000 VL 13 IS 6 BP 999 EP 1003 DI 10.1023/A:1026466711595 PG 5 WC Physics, Applied; Physics, Condensed Matter SC Physics GA 378DD UT WOS:000165569000028 ER PT J AU Reid, RS Swift, GW AF Reid, RS Swift, GW TI Experiments with a flow-through thermoacoustic refrigerator SO JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA LA English DT Article ID ENGINES AB Deliberate superposition of steady flow parallel to the thermoacoustic oscillations in a stack is used to cool the steady flow as it passes through the stack. The loudspeaker-driven refrigerator described here cools a flowing helium-argon mixture from 35 to 27 degreesC and provides additional cooling power at a traditional cold heat exchanger. The dependence of the stack's temperature profile and of the additional cooling power on the steady flow rate are in agreement with a simple theory based on augmentation of the well-known thermoacoustic momentum, continuity, and energy equations with a single new term in the energy equation that describes the steady flow. (C) 2000 Acoustical Society of America. [S0001-4966(00)04712-3]. C1 Univ Calif Los Alamos Natl Lab, Energy & Proc Engn Grp, Los Alamos, NM 87545 USA. Univ Calif Los Alamos Natl Lab, Condensed Matter & Thermal Phys Grp, Los Alamos, NM 87545 USA. RP Reid, RS (reprint author), Univ Calif Los Alamos Natl Lab, Energy & Proc Engn Grp, POB 1663, Los Alamos, NM 87545 USA. NR 14 TC 13 Z9 13 U1 0 U2 1 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0001-4966 J9 J ACOUST SOC AM JI J. Acoust. Soc. Am. PD DEC PY 2000 VL 108 IS 6 BP 2835 EP 2842 DI 10.1121/1.1323721 PG 8 WC Acoustics; Audiology & Speech-Language Pathology SC Acoustics; Audiology & Speech-Language Pathology GA 381TV UT WOS:000165780300016 ER PT J AU Plucknett, KP AF Plucknett, KP TI Joining Si3N4-based ceramics with oxidation-formed surface layers SO JOURNAL OF THE AMERICAN CERAMIC SOCIETY LA English DT Article ID SIALON-GLASS ADHESIVES; MECHANICAL-PROPERTIES; SILICON-NITRIDE; SI3N4 AB A simple processing technique has been developed for joining Si3N4,-based ceramics. Thin (<5 m thick), amorphous, or partially crystalline SiO2-based surface layers were formed, via low-temperature oxidation (at 1200 degreesC), on the faces to be joined. Joining of the surface-coated pieces could then be performed in an inert environment at typical sintering/joining temperatures (i,e., 1700 degreesC), with or without applied gas pressure, via a transient viscous/liquid phase. This method was most effective for Si3N4 ceramics with single oxide sintering additives when a thin (similar to1 mum thick), highly smooth (RMS roughness <60 nm) SiO2 layer was formed, and essentially 'pore-free' joints could be formed. However, the method was less suitable for a multi additive SiAlON material under current experimental conditions, as relatively high roughness (RMS roughness >400 nm) oxide scales formed, leaving residual porosity at the joint interface. C1 Oak Ridge Natl Lab, Div Met & Ceram, Oak Ridge, TN 37831 USA. RP Plucknett, KP (reprint author), DERA, Struct Mat Ctr, Griffith Bldg A7, Farnborough GU14 0LX, Hants, England. NR 14 TC 4 Z9 4 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 DEC PY 2000 VL 83 IS 12 BP 2925 EP 2928 PG 4 WC Materials Science, Ceramics SC Materials Science GA 381DD UT WOS:000165746300005 ER PT J AU Zheng, J Kramer, MJ Akinc, M AF Zheng, J Kramer, MJ Akinc, M TI In situ growth of SiC whisker in pyrolyzed monolithic mixture of AHPCS and SiC SO JOURNAL OF THE AMERICAN CERAMIC SOCIETY LA English DT Article AB In situ whisker growth was observed during heat treatment of allylhydridopolycarbosilane (AHPCS) and SLC powder in the temperature range of 1250 degrees -1350 degreesC. TEM equipped with an electron energy loss spectrometer (EELS) verified that the banded whiskers are twinned single-grained P-SIC. Convergent beam electron diffraction patterns (CBED) of the whisker tips were consistent with formation by a vapor-solid (VS) mechanism. The effects of process variables on whisker growth were addressed. The mechanism of whisker growth was discussed and attributed to the reaction between the gaseous products of the polymers AHPCS and polycarbosilane (PCS). Thermal decomposition behavior of the polymers was followed to relate gas evolution to whisker formation. C1 Iowa State Univ, Ames Lab, Ames, IA 50011 USA. Iowa State Univ, Dept Mat Sci & Engn, Ames, IA 50011 USA. RP Zheng, J (reprint author), Iowa State Univ, Ames Lab, Ames, IA 50011 USA. NR 18 TC 16 Z9 18 U1 2 U2 7 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 DEC PY 2000 VL 83 IS 12 BP 2961 EP 2966 PG 6 WC Materials Science, Ceramics SC Materials Science GA 381DD UT WOS:000165746300010 ER PT J AU Besmann, TM Kupp, ER Lara-Curzio, E More, KL AF Besmann, TM Kupp, ER Lara-Curzio, E More, KL TI Ceramic composites with multilayer interface coatings SO JOURNAL OF THE AMERICAN CERAMIC SOCIETY LA English DT Article ID OXIDATION MECHANISMS; INTERPHASES; CVI; KINETICS; OXYGEN AB Silicon carbide matrix composites have been fabricated from either ceramic-grade Nicalon((TM)) or Hi-Nicalon((TM)) fibers coated with an interface material consisting of six alternating carbon and silicon carbide layers. Initial efforts involved the use of chemical vapor infiltration to produce minicomposites (single toms of fibers). In subsequent work, forced-flow thermal-gradient chemical vapor infiltration was used to produce a single composite plate with a multilayer interface from ceramic-grade Nicalon fabric and two plates from Hi-Nicalon fabric, one with a single carbon layer and one with a multilayer interface. Tensile testing of the minicomposites and of specimens cut from the plates revealed typical composite behavior and strengths for the as processed samples. Exposure of tensile specimens to 950 degreesC air for 100 h resulted in large losses in strength and strain tolerance regardless of the interface coating. The results demonstrate that forced-flow thermal-gradient chemical vapor infiltration can be used to prepare multilayer interface material. The results also verified that relatively thick (>100 nm) single or multiple carbon layers are susceptible to oxidation that causes the loss of composite properties. C1 Oak Ridge Natl Lab, Div Met & Ceram, Oak Ridge, TN 37831 USA. RP Besmann, TM (reprint author), Oak Ridge Natl Lab, Div Met & Ceram, POB 2008, Oak Ridge, TN 37831 USA. RI More, Karren/A-8097-2016 OI More, Karren/0000-0001-5223-9097 NR 30 TC 15 Z9 15 U1 3 U2 5 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 DEC PY 2000 VL 83 IS 12 BP 3014 EP 3020 PG 7 WC Materials Science, Ceramics SC Materials Science GA 381DD UT WOS:000165746300019 ER PT J AU Boling-Risser, MA Goretta, KC Routbort, JL Faber, KT AF Boling-Risser, MA Goretta, KC Routbort, JL Faber, KT TI Effect of microstructure on high-temperature compressive creep of self-reinforced hot-pressed silicon nitride SO JOURNAL OF THE AMERICAN CERAMIC SOCIETY LA English DT Article ID GRAIN-BOUNDARY PHASE; TENSILE CREEP; CERAMICS; GLASS; DEFORMATION; GROWTH AB An experimental self-reinforced hot-pressed silicon nitride was used to examine the effects of microstructure on high-temperature deformation mechanisms during compression testing. At 1575-1625 degreesC, the as-received material exhibited a stress exponent of 1 and appeared to deform by steady-state grain-boundary sliding accommodated by solution reprecipitation of silicon nitride through the grain-boundary phase. The activation energy was 610 +/- 110 kJ/mol. At 1450 -1525 degreesC for the as-received material, and at 1525-1600 degreesC for the larger-grained heat-treated samples, the stress exponent was >1, Damage, primarily in the form of pockets of intergranular material at two-grain junctions, was observed in these samples. C1 Argonne Natl Lab, Argonne, IL 60439 USA. Northwestern Univ, Dept Mat Sci & Engn, Evanston, IL 60208 USA. RP Boling-Risser, MA (reprint author), Argonne Natl Lab, 9700 S Cass Ave, Argonne, IL 60439 USA. RI Faber, Katherine/B-6741-2009 NR 27 TC 13 Z9 13 U1 0 U2 2 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 DEC PY 2000 VL 83 IS 12 BP 3065 EP 3069 PG 5 WC Materials Science, Ceramics SC Materials Science GA 381DD UT WOS:000165746300026 ER PT J AU Imamura, PH Evans, ND Sakuma, T Mecartney, ML AF Imamura, PH Evans, ND Sakuma, T Mecartney, ML TI High-temperature tensile deformation of glass-doped 3Y-TZP SO JOURNAL OF THE AMERICAN CERAMIC SOCIETY LA English DT Article ID TETRAGONAL ZIRCONIA POLYCRYSTAL; SUPERPLASTIC FLOW; MICROSTRUCTURE; ADDITIONS; COMPOSITE; BEHAVIOR AB Amorphous grain boundary phases in 3-mol%-yttriastabilized zirconia ceramics (3Y-TZP) were studied to determine the influence of intergranular amorphous silicate phases on tensile superplasticity at temperatures of 1300-1500 degreesC. Controlled additions (1 wt%) of compositionally distinct barium silicate and borosilicate phases were used. The initial grain sizes of the pure, barium silicate added, and borosilicate-added samples were 0.45, 0.55, and 0.55 mum, respectively. Systems with added barium silicate and borosilicate glass both exhibited a 60% reduction in flow stress as compared with pure 3Y-TZP, with the lower-viscosity barium silicate system exhibiting a slightly greater reduction in flow stress. The higher-viscosity borosilicate glass/3Y-TZP materials exhibited the greatest elongation to failure, while the barium silicate/3Y-TZP materials had the least elongation. Yttrium was found to segregate to grain boundaries in the pure and borosilicate-containing samples, and both yttrium and barium were found to segregate to grain boundaries in the barium silicate containing samples. No silicon was observed along two-grain boundaries in any of the samples, even those containing pockets of glass, The difference in deformation behavior may be due to a combination of viscosity of the glass addition, grain boundary segregation, and grain boundary bond character. C1 Univ Calif Irvine, Dept Chem & Biochem Engn & Mat Sci, Irvine, CA 92697 USA. Oak Ridge Natl Lab, Div Met & Ceram, Oak Ridge, TN 37830 USA. Univ Tokyo, Dept Mat Sci, Bunkyo Ku, Tokyo 113, Japan. RP Imamura, PH (reprint author), Univ Calif Irvine, Dept Chem & Biochem Engn & Mat Sci, Irvine, CA 92697 USA. RI Evans, Neal/F-5955-2011 NR 28 TC 8 Z9 8 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 DEC PY 2000 VL 83 IS 12 BP 3095 EP 3099 PG 5 WC Materials Science, Ceramics SC Materials Science GA 381DD UT WOS:000165746300031 ER PT J AU Saruhan, B Abothu, IR Komarneni, S Loong, CK AF Saruhan, B Abothu, IR Komarneni, S Loong, CK TI Crystallization of electrostatically seeded lanthanum hexaluminate films on polycrystalline oxide fibers SO JOURNAL OF THE AMERICAN CERAMIC SOCIETY LA English DT Article ID COMPOSITES; ALUMINA; STABILITY; KINETICS; COATINGS AB Lanthanum hexaluminate (LaAl11O18), which features easily cleavable atomic planes in the magnetoplumbite (MP) structure, is a good candidate material for the fiber/matrix interface in oxide/oxide-fiber-reinforced composites. Difficulties that are encountered when using sol-gel synthesis to produce this material include the high crystallization temperature and the occurrence of an intermediate phase. This paper presents a method to overcome these difficulties by introducing crystalline seeds into the LaAl11O18 sol during the fiber coating. Seed particles are deposited initially on the fibers via electrostatic forces, Then, the sol is dip-coated on the preseeded fibers, and the final LaAl11O18 coating is achieved,ia the use of heat treatments. The crystallization temperature can be reduced by at least 50 degreesC, in comparison with that for the unseeded case, according to differential scanning calorimetry measurements, and no intermediate LaAlO3 phase is formed. The estimated seed numbers are on the order of 10(9) seeds/cm(3) in the preseeded sol-coated fiber surfaces and 10(11) seeds/cm3 in the 4-wt%-seeded gels. The crystallization and structure of the La1-xAl12-yO19-z MP phase in the 4-wt%-seeded gels that have been heated at 400 degrees and 1200 degreesC have been studied using powder neutron diffraction. C1 Inst Mat Res Cologne, German Aerosp Ctr, D-51147 Koeln, Germany. Penn State Univ, Mat Res Lab, University Pk, PA 16802 USA. Argonne Natl Lab, Intense Pulsed Neutron Source Div, Argonne, IL 60439 USA. RP Saruhan, B (reprint author), Inst Mat Res Cologne, German Aerosp Ctr, D-51147 Koeln, Germany. NR 28 TC 7 Z9 7 U1 0 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 DEC PY 2000 VL 83 IS 12 BP 3172 EP 3178 PG 7 WC Materials Science, Ceramics SC Materials Science GA 381DD UT WOS:000165746300043 ER PT J AU Duckworth, DC Goeringer, DE McLuckey, SA AF Duckworth, DC Goeringer, DE McLuckey, SA TI Measurement of collision-induced dissociation rates for tantalum oxide ions in a quadrupole ion trap SO JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY LA English DT Article ID DISCHARGE MASS-SPECTROMETRY; RADIOFREQUENCY GLOW-DISCHARGE; ACTIVATION; RESOLUTION; GAS AB A study of factors influencing the collision-induced dissociation (CID) rate of strongly bound diatomic ions effected via resonance excitation in a quadrupole ion trap is presented. From these studies, an approach to measuring the CID rates is described wherein product ion recovery is optimized and the effect of competitive processes (e.g., parent ion ejection and product ion reactions) on rate measurements are prevented from influencing rate measurements. Tantalum oxide ions (dissociation energy = 8.2 eV), used as a model system, were formed via reactions of glow discharge generated Ta+ ions with residual gases in the ion trap. Neon (0.5 mtorr) was found to be a more favorable target gas for the dissociation of TaO+ than He and Ar, but collisional activation of TaO+ ions in neon during ion isolation by mass selective instability necessitated ion cooling prior to dissociation. A 25 ms delay time at q(z) = 0.2 allowed for kinetic cooling of stored TaO+ ions and enabled precise dissociation rate measurements to be made. CID of TaO+ was determined to be most efficient at q(z) = 0.67 to (226 kHz for m/z 197). Suitable resonance excitation voltages and times ranged from 0.56 to 1.2 Vp-p and 1 to 68 ms, respectively. Under these conditions, measurement of rates approaching 80 s(-1) for the dissociation of TaO+ could be made without significant complications associated with competing processes, such as ion ejection. (J Am Soc Mass Spectrom 2000, 11, 1072-1078) (C) 2000 American Society for Mass Spectrometry. C1 Oak Ridge Natl Lab, Div Chem & Analyt Sci, Oak Ridge, TN 37831 USA. Purdue Univ, Dept Chem, W Lafayette, IN 47907 USA. RP Oak Ridge Natl Lab, Div Chem & Analyt Sci, POB 2008, Oak Ridge, TN 37831 USA. EM DuckworthDC@ornl.gov RI McLuckey, Scott/B-2203-2009; Duckworth, Douglas/B-7171-2015 OI McLuckey, Scott/0000-0002-1648-5570; Duckworth, Douglas/0000-0002-8161-5685 NR 30 TC 6 Z9 6 U1 1 U2 2 PU SPRINGER PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 1044-0305 EI 1879-1123 J9 J AM SOC MASS SPECTR JI J. Am. Soc. Mass Spectrom. PD DEC PY 2000 VL 11 IS 12 BP 1072 EP 1078 DI 10.1016/S1044-0305(00)00185-9 PG 7 WC Biochemical Research Methods; Chemistry, Analytical; Chemistry, Physical; Spectroscopy SC Biochemistry & Molecular Biology; Chemistry; Spectroscopy GA 378CZ UT WOS:000165568600005 PM 11118114 ER PT J AU Yang, H Kwon, K Devine, TM Evans, JW AF Yang, H Kwon, K Devine, TM Evans, JW TI Aluminum corrosion in lithium batteries - An investigation using the electrochemical quartz crystal microbalance SO JOURNAL OF THE ELECTROCHEMICAL SOCIETY LA English DT Article ID CURRENT COLLECTORS; ELECTROLYTES; SALTS; STABILITY; OXIDATION; WATER; CELLS AB An electrochemical quartz crystal microbalance is used in an investigation of the corrosion of aluminum in electrolytes appropriate for lithium batteries. The electrolytes are solutions of LiN(CF3SO2)(2) LIC(CF3SO2)(3), LiCF3SO3, LiPF6, LiBF4, and LiClO4, singly or in a limited number of combinations, in propylene carbonate (PC) and polyethylene glycol dimethyl ether Aluminum that is scratched or abraded in an inert atmosphere (so that a protective surface film does not reform) undergoes significant corrosion in PC containing LiN(CF3SO2)(2), LiC(CF3SO2)(3), LiCF3SO3, and LiClO4, but forms a protective film in PC containing LiPF6, or LiBF4. A mechanism of corrosion of aluminum in LiN(CF3SO2)(2)/PC is proposed. (C) 2000 The Electrochemical Society. S0013-4651(99)10-054-5. All rights reserved. C1 Univ Calif Berkeley, Dept Mat Sci & Engn, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Environm Energy Technol Div, Berkeley, CA 94720 USA. RP Evans, JW (reprint author), ETRI, Taejon 305350, South Korea. RI Yang, Haesik/A-7231-2012 NR 19 TC 109 Z9 116 U1 7 U2 51 PU ELECTROCHEMICAL SOC INC PI PENNINGTON PA 65 SOUTH MAIN STREET, PENNINGTON, NJ 08534 USA SN 0013-4651 J9 J ELECTROCHEM SOC JI J. Electrochem. Soc. PD DEC PY 2000 VL 147 IS 12 BP 4399 EP 4407 DI 10.1149/1.1394077 PG 9 WC Electrochemistry; Materials Science, Coatings & Films SC Electrochemistry; Materials Science GA 376RD UT WOS:000165469800003 ER PT J AU Um, S Wang, CY Chen, KS AF Um, S Wang, CY Chen, KS TI Computational fluid dynamics modeling of proton exchange membrane fuel cells SO JOURNAL OF THE ELECTROCHEMICAL SOCIETY LA English DT Article ID POLYMER-ELECTROLYTE; MATHEMATICAL-MODEL; BATTERIES; MANAGEMENT; TRANSPORT; PLATINUM; WATER AB A transient, multidimensional model has been developed to simulate proton exchange membrane fuel cells. The model accounts simultaneously for electrochemical kinetics, current distribution, hydrodynamics. and multicomponent transport. A single set of conservation equations valid for flow channels, gas-diffusion electrodes, catalyst layers, and the membrane region are developed and numerically solved using a finite-volume-based computational fluid dynamics technique. The numerical model is validated against published experimental data with good agreement. Subsequently, the model is applied to explore hydrogen dilution effects in the anode feed. The predicted polarization curves under hydrogen dilution conditions are in qualitative agreement with recent experiments reported in the literature. The detailed two-dimensional electrochemical and flow/transport simulations further reveal that in the presence of hydrogen dilution in the fuel stream, hydrogen is depleted at the reaction surface, resulting in substantial anode mass transport polarization and hence a lower current density that is limited by hydrogen transport from the fuel stream to the reaction site. Finally, a transient simulation of the cell current density response to a step change in cell voltage is reported. (C) 2000 The Electrochemical Society. S0013-4651(00)08-104-0. All rights reserved. C1 Penn State Univ, Dept Mech & Nucl Engn, GATE, Ctr Adv Energy Storage, University Pk, PA 16802 USA. Sandia Natl Labs, Engn Sci Ctr, Albuquerque, NM 87185 USA. RP Um, S (reprint author), Penn State Univ, Dept Mech & Nucl Engn, GATE, Ctr Adv Energy Storage, 227 Hammond Bldg, University Pk, PA 16802 USA. EM cxw31@psu.edu RI Wang, Chao-Yang/C-4122-2009 NR 28 TC 486 Z9 498 U1 10 U2 77 PU ELECTROCHEMICAL SOC INC PI PENNINGTON PA 65 SOUTH MAIN STREET, PENNINGTON, NJ 08534 USA SN 0013-4651 J9 J ELECTROCHEM SOC JI J. Electrochem. Soc. PD DEC PY 2000 VL 147 IS 12 BP 4485 EP 4493 DI 10.1149/1.1394090 PG 9 WC Electrochemistry; Materials Science, Coatings & Films SC Electrochemistry; Materials Science GA 376RD UT WOS:000165469800016 ER PT J AU Totir, D Mo, YB Kim, S Antonio, MR Scherson, DA AF Totir, D Mo, YB Kim, S Antonio, MR Scherson, DA TI In situ CoK-edge X-ray absorption fine structure of cobalt hydroxide film electrodes in alkaline solutions SO JOURNAL OF THE ELECTROCHEMICAL SOCIETY LA English DT Article ID HYDROUS OXIDE-FILMS; NICKEL-HYDROXIDE; ELECTROCHEMICAL-BEHAVIOR; ELECTROLYTES; OXIDATION; MECHANISM; CHARGE AB Structural and electronic properties of electrodeposited Cu(OH)(2) films on Au electrodes in alkaline solutions have been characterized in situ by Co K-edge X-ray absorption spectroscopy (XAS). The results obtained have shown that freshly prepared films undergo spontaneous partial and irreversible oxidation in 1 M KOH solution even when polarized at -0.58 V vs. Hg/HgO,OH-, as evidenced by the presence of contributions (ca. 20%) from Co-O and Co-Co shells in the extended X-ray absorption fine structure (EXAFS) attributed to CoOOH. Subsequent polarization of the electrode at + 0.6 V oxidizes a significant fraction, but not all of the Co(OH)(2) into CoOOH, as judged by the occurrence of Co-O and Co-Co shells in the EXAFS ascribed to Co(OH)(2). Further reduction of the same film at -0.58 V vs. Hg/HgO,OH- increased the amount of Co(OH)(2) from 28 to 43%, indicating that the fraction of electrochemically active sites does not exceed ca. 15%. On this basis, the redox activity of Co hydroxide is probably associated with surface rather than bulk Co2+/Co3+ sites in the lattice. These results suggest that Co(OH)(2) present as a distinct pure phase in technical Ni oxide electrodes does not contribute significantly to charge storage during cycling, nor to changes in the redox properties of the electrochemically active material. (C) 2000 The Electrochemical Society. All rights reserved. C1 Case Western Reserve Univ, Dept Chem, Cleveland, OH 44106 USA. Konkuk Univ, Dept Chem, Seoul, South Korea. Argonne Natl Lab, Div Chem, Argonne, IL 60439 USA. RP Totir, D (reprint author), Case Western Reserve Univ, Dept Chem, Cleveland, OH 44106 USA. NR 28 TC 19 Z9 19 U1 3 U2 14 PU ELECTROCHEMICAL SOC INC PI PENNINGTON PA 65 SOUTH MAIN STREET, PENNINGTON, NJ 08534 USA SN 0013-4651 J9 J ELECTROCHEM SOC JI J. Electrochem. Soc. PD DEC PY 2000 VL 147 IS 12 BP 4594 EP 4597 DI 10.1149/1.1394107 PG 4 WC Electrochemistry; Materials Science, Coatings & Films SC Electrochemistry; Materials Science GA 376RD UT WOS:000165469800033 ER PT J AU Driscoll, D Yazdanian, M Siminovitch, M AF Driscoll, D Yazdanian, M Siminovitch, M TI Structural stability analysis of a quartz fiber optic coupler under thermal loading SO JOURNAL OF THE ILLUMINATING ENGINEERING SOCIETY LA English DT Article AB A new fiber optic coupler is being developed which will employ 150-0400 W lamps. In this new design the lamp will be surrounded by and directly in contact with, the coupler A major concern with this design is the structural stability of the material surrounding the lamp, because it would need to endure extremely high and rapidly fluctuating temperatures. Because of its thermal stability and desirable optical properties, quartz was the most practical material to use for the coupling system. However, the direct contact between the lamp and the quartz leads to extreme thermal conditions that merit close investigation. To confirm its stability, a detailed thermal analysis was performed on quartz of the approximate size and shape as the specific coupler situation in question. Theoretical computer models, physical quartz models with heating coils to simulate the lamp, computer models based on collected data, and infrared thermographs were used for the analysis. The models and experimental data were used to determine if quartz will remain structurally stable in the proposed couplersituation, or if it will crack or melt due to the ther mal load. Our findings showed that quartz is an ideal material for the coupler because it can withstand the extreme and fluctuating temper-attires of the lamp. This paper describes the results of our tests and models and presents the conclusions drawn fi-om the compiled data. The concept development, analysis of problems, and establishment of procedure have all been completed. All necessary data has been collected or computed, but one experiment is currently being repeated to obtain more data points. Except for the data that will be collected from the additional experiment, the paper is completed with all intended tables and figures. It has passed through thorough internal reviews and will be complete once the additional data points are included. C1 Lawrence Berkeley Natl Lab, Lighting Res Grp, Berkeley, CA 94720 USA. RP Driscoll, D (reprint author), Lawrence Berkeley Natl Lab, Lighting Res Grp, Berkeley, CA 94720 USA. NR 4 TC 0 Z9 0 U1 1 U2 4 PU ILLUMINAT ENG SOC NORTH AMER PI NEW YORK PA 120 WALL ST, 17TH FL, NEW YORK, NY 10005-4001 USA SN 0099-4480 J9 J ILLUM ENG SOC JI J. Illum. Eng. Soc. PD WIN PY 2000 VL 29 IS 1 BP 59 EP + PG 8 WC Optics SC Optics GA 337YR UT WOS:000088391500009 ER PT J AU Koetsier, P McArthur, JV AF Koetsier, P McArthur, JV TI Organic matter retention by macrophyte beds in 2 southeastern USA, low-gradient, headwater streams SO JOURNAL OF THE NORTH AMERICAN BENTHOLOGICAL SOCIETY LA English DT Article DE Sparganium americanum; macrophyte beds; retention; leaf analog; organic matter; Coastal Plains; blackwater streams ID DEBRIS DAMS; DYNAMICS; FLOODPLAIN; ECOSYSTEM; TRANSPORT; CARBON; SYSTEM; SESTON; RIVER; LIFE AB We examined particulate organic matter (POM) storage and retention in aquatic macrophyte beds (Sparganium ameticanum Nutt.) from 2, first-order, blackwater tributaries of Tinker Creek, South Carolina, USA. Measurements were made during the autumn (high lifter input) and summer (low litter input), in 100-m study reaches, 1 with low macrophyte density (T-1) and 1 with high macrophyte density (T-2). Three experiments assessed: 1) POM retention by individual plant beds, 2) short-term retention of leaf analogs in plant beds and by other retention structures, and 3) benthic and transported POM at the reach scale. Upon completion, all above ground macrophyte biomass was removed and the experiments were repeated. At the scale of 1 bed, low plant density effectively trapped and stored POM in summer and autumn High-density beds stored POM in the summer but during autumn POM output exceeded input. At the reach scale, both tributaries effectively retained coarse POM in summer, but only high-density beds did so in autumn. Likewise, only high-density beds trapped and retained fine POM. Following plant removal, both coarse and fine POM were transported with minimal retention. When plants were present, beds played a major role in leaf analog retention and increased the retentive capabilities of other channel structures (debris dams, overhanging vegetation). When beds were removed, most analogs were retained by debris dams or settled to the substrate Macrophyte beds play a major role in POM retention and short-term storage in low-gradient blackwater streams at several spatial scales and are linked to retention by other channel structures. The importance of macrophyte beds varies depending on bed density, total surface coverage, and timing of leaf fall. C1 Boise State Univ, Dept Biol, Boise, ID 83725 USA. Univ Georgia, Savannah River Ecol Lab, Aiken, SC 29802 USA. RP Koetsier, P (reprint author), Boise State Univ, Dept Biol, 1910 Univ Dr, Boise, ID 83725 USA. NR 49 TC 17 Z9 18 U1 2 U2 11 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 DEC PY 2000 VL 19 IS 4 BP 633 EP 647 DI 10.2307/1468122 PG 15 WC Ecology; Marine & Freshwater Biology SC Environmental Sciences & Ecology; Marine & Freshwater Biology GA 390QM UT WOS:000166307900005 ER PT J AU Hakioglu, T AF Hakioglu, T TI Canonical-covariant Wigner function in polar form SO JOURNAL OF THE OPTICAL SOCIETY OF AMERICA A-OPTICS IMAGE SCIENCE AND VISION LA English DT Article ID GROENEWOLD-MOYAL QUANTIZATION; ALGEBRAIC APPROACH; QUANTUM PHASE; TRANSFORMATIONS; SIGNALS AB The two-dimensional Wigner function is examined in polar canonical coordinates, and covariance properties under the action of affine canonical transformations are derived. (C) 2000 Optical Society of America [S0740-3232(00)03912-0] OCIS codes: 080.0080, 070.0070, 270.0270, 000.3860, 000.1600. C1 Bilkent Univ, Dept Phys, TR-06533 Ankara, Turkey. Argonne Natl Lab, Div High Energy Phys, Argonne, IL 60439 USA. RP Hakioglu, T (reprint author), Bilkent Univ, Dept Phys, TR-06533 Ankara, Turkey. NR 32 TC 2 Z9 2 U1 0 U2 0 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA SN 0740-3232 J9 J OPT SOC AM A JI J. Opt. Soc. Am. A-Opt. Image Sci. Vis. PD DEC PY 2000 VL 17 IS 12 BP 2411 EP 2421 DI 10.1364/JOSAA.17.002411 PG 11 WC Optics SC Optics GA 381FU UT WOS:000165752300032 PM 11140501 ER PT J AU Zhang, Y Vijayalakshmi, S Ajgaonkar, M Grebel, H White, CW AF Zhang, Y Vijayalakshmi, S Ajgaonkar, M Grebel, H White, CW TI Optical properties of an ordered array of silica nanospheres embedded with silicon nanoclusters SO JOURNAL OF THE OPTICAL SOCIETY OF AMERICA B-OPTICAL PHYSICS LA English DT Article ID ARTIFICIAL DIELECTRICS; SI NANOPARTICLES; PHOTOLUMINESCENCE AB The optical properties of Si nanoclusters embedded within an ordered array of silica spheres have been measured. Raman data were used to confirm the existence of the Si nanoclusters. Reflection measurements and a large photoluminescence signal demonstrated the effect of the periodic structure on the optical characteristics. The wavelength-dependent, photoluminescence decay time was in the range of 7 to 24 mus for lambda = 650 to lambda = 850 nn, respectively, implying contributions from surface or interface states. (C) 2000 Optical Society of America [S0740-3224(00)01612-X] OCIS codes: 020.4180, 050.1940, 060.5060, 130.0250, 130.4310, 240.5860. C1 New Jersey Inst Technol, Nonlinear Nanostruct Lab, Newark, NJ 07102 USA. Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Grebel, H (reprint author), New Jersey Inst Technol, Nonlinear Nanostruct Lab, Newark, NJ 07102 USA. EM grebel@njit.edu NR 13 TC 5 Z9 5 U1 0 U2 0 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA SN 0740-3224 EI 1520-8540 J9 J OPT SOC AM B JI J. Opt. Soc. Am. B-Opt. Phys. PD DEC PY 2000 VL 17 IS 12 BP 1967 EP 1972 DI 10.1364/JOSAB.17.001967 PG 6 WC Optics SC Optics GA 382QH UT WOS:000165833400002 ER PT J AU Agio, M Lidorikis, E Soukoulis, CM AF Agio, M Lidorikis, E Soukoulis, CM TI Impurity modes in a two-dimensional photonic crystal: coupling efficiency and Q factor SO JOURNAL OF THE OPTICAL SOCIETY OF AMERICA B-OPTICAL PHYSICS LA English DT Article ID NEAR-INFRARED WAVELENGTHS; WAVE-GUIDES; MICROCAVITIES; TRANSMISSION; EMISSION; BENDS AB A finite two-dimensional photonic crystal with a triangular lattice of air columns in a dielectric background is designed with a waveguide and a resonant cavity. By a time-domain solution of Maxwell's equations we observe the existence of impurity modes inside the photonic bandgap. An electromagnetic wave launched through the waveguide, with an appropriate frequency, can enhance the field inside the cavity and yield a peak in the transmission. Considering a manufactured structure, in which the columns are not perfectly equal, we repeat our calculations and analyze how the impurity modes are modified. For both cases, periodic and real, we measure the quality factor of the cavity. (C) 2000 Optical Society of America [S0740-3224(00)01012-2] OCIS codes: 230.7370, 230.5750. C1 Iowa State Univ, Ames Lab, Ames, IA 50011 USA. Iowa State Univ, Dept Phys & Astron, Ames, IA 50011 USA. RP Agio, M (reprint author), Iowa State Univ, Ames Lab, Ames, IA 50011 USA. RI Agio, Mario/F-7366-2011; Soukoulis, Costas/A-5295-2008; OI Agio, Mario/0000-0003-3282-5982; Lidorikis, Elefterios/0000-0002-9552-9366 NR 22 TC 14 Z9 14 U1 0 U2 5 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 DEC PY 2000 VL 17 IS 12 BP 2037 EP 2042 DI 10.1364/JOSAB.17.002037 PG 6 WC Optics SC Optics GA 382QH UT WOS:000165833400012 ER PT J AU Wood-Vasey, WM Budil, KS Remington, BA Glendinning, SG Rubenchik, AM Berning, M Kane, JO Larsen, JT AF Wood-Vasey, WM Budil, KS Remington, BA Glendinning, SG Rubenchik, AM Berning, M Kane, JO Larsen, JT TI Computational modeling of classical and ablative Rayleigh-Taylor instabilities SO LASER AND PARTICLE BEAMS LA English DT Article DE linear; modeling; nonlinear; Rayleigh-Taylor instability ID INERTIAL CONFINEMENT FUSION; GROWTH-RATES; FRONTS; NOVA; HYDRODYNAMICS; STABILITY; INTERFACE; PLASMA; LASER AB Modeling nine simulations using the one-dimensional Lagrangian radiation-hydrodynamics code HYADES are compared with data from classical and ablative Rayleigh-Taylor experiments conducted on the Nova laser. Comparisons between the experiments amd modeling for both the gross hydrodynamic motion and the perturbation evolution are made and show good agreement. A third order perturbation analysis is applied to demonstrate the onset of nonlinearity. A simple, physically intuitive saturation model is used to describe the growth further into the nonlinear regime. Finally, we present the first comparison of the Betti ablation front theory with indirect-drive RT data and obtain good agreement. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. Harvey Mudd Coll, Claremont, CA 91711 USA. RP Remington, BA (reprint author), Univ Calif Lawrence Livermore Natl Lab, L-021, Livermore, CA 94550 USA. NR 34 TC 3 Z9 3 U1 0 U2 2 PU CAMBRIDGE UNIV PRESS PI PORT CHESTER PA 110 MIDLAND AVE, PORT CHESTER, NY 10573-9863 USA SN 0263-0346 J9 LASER PART BEAMS JI Laser Part. Beams PD DEC PY 2000 VL 18 IS 4 BP 583 EP 593 DI 10.1017/S0263034600184022 PG 11 WC Physics, Applied SC Physics GA 434ZK UT WOS:000168845600002 ER PT J AU Hassanein, A AF Hassanein, A TI Liquid-metal targets for high-power applications: Pulsed heating and shock hydrodynamics SO LASER AND PARTICLE BEAMS LA English DT Article AB Significant interest has recently focused on the use of liquid-metal targets flowing with high velocities for various high-power nuclear and high-energy physics applications such as fusion reactor first-walls, the Spallation Neutron Source, Isotope Separation On Line, and Muon Collider projects. This is because the heat generated in solid targets due to beam or plasma bombardment cannot be removed easily and the resulting thermal shock damage could be a serious lifetime problem for long-term operation. More recently, the use of free or open flying-liquid jets has been proposed for higher-power-density applications. The behavior of a free-moving liquid mercury or gallium jet subjected to proton beam deposition in a strong magnetic field has been modeled and analyzed for the Muon Collider project. Free-liquid-metal jets can offer significant advantages over conventional solid targets, particularly for the more demanding and challenging high-power applications. However, the use of free-moving liquid-metal targets raises a number of new and challenging problems such as instabilities of the jet in a strong magnetic field, induced eddy-current effects on jet shape, thermal-shock formation, and possible jet fragmentation. Problems associated with shock heating of liquid jets in a strong magnetic field are analyzed in this study. C1 Argonne Natl Lab, Argonne, IL 60439 USA. RP Hassanein, A (reprint author), Argonne Natl Lab, 9700 S Cass Ave, Argonne, IL 60439 USA. NR 5 TC 4 Z9 4 U1 0 U2 1 PU CAMBRIDGE UNIV PRESS PI PORT CHESTER PA 110 MIDLAND AVE, PORT CHESTER, NY 10573-9863 USA SN 0263-0346 J9 LASER PART BEAMS JI Laser Part. Beams PD DEC PY 2000 VL 18 IS 4 BP 611 EP 622 DI 10.1017/S0263034600184058 PG 12 WC Physics, Applied SC Physics GA 434ZK UT WOS:000168845600005 ER PT J AU Frantz, BR Kashgarian, M Coale, KH Foster, MS AF Frantz, BR Kashgarian, M Coale, KH Foster, MS TI Growth rate and potential climate record from a rhodolith using C-14 accelerator mass spectrometry SO LIMNOLOGY AND OCEANOGRAPHY LA English DT Article ID MARINE SAMPLES; RADIOCARBON; CALIFORNIA; ATMOSPHERE; CORAL; GULF; AGES AB Rhodoliths, free-living calcareous red algae, create large and diverse habitats worldwide. Although these plants are abundant and ecologically important, little is known about their growth rate. We determined the growth rate for an individual rhodolith, Lithothamnium crassiusculum, from the southern Gulf of California through C-14 analysis using accelerator mass spectrometry (AMS) to be 0.6 mm yr(-1). This growth rate suggests large L. crassiusculum, which have been found with radii in excess of 6 cm, may live over 100 yr. Declines in the Delta C-14 record associated with the large El Nino events of 1957, 1982, and 1992 indicate C-14 analysis may lead to identification of important climate events in the more distant past. The ability to determine changes in past ocean circulation related to changes in past climatic conditions through AMS C-14 analysis of rhodoliths would increase the geographic range of available climate records from the tropical oceans to the entire global ocean and potentially allow for the determination of past climate conditions from rhodoliths in fossil beds. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. Moss Landing Marine Labs, Moss Landing, CA 95039 USA. RP Frantz, BR (reprint author), Univ Calif Lawrence Livermore Natl Lab, 7000 East Ave,L-403, Livermore, CA 94550 USA. RI Kashgarian, Michaele/E-1665-2011 OI Kashgarian, Michaele/0000-0001-7824-8418 NR 23 TC 59 Z9 60 U1 0 U2 3 PU AMER SOC LIMNOLOGY OCEANOGRAPHY PI WACO PA 5400 BOSQUE BLVD, STE 680, WACO, TX 76710-4446 USA SN 0024-3590 J9 LIMNOL OCEANOGR JI Limnol. Oceanogr. PD DEC PY 2000 VL 45 IS 8 BP 1773 EP 1777 PG 5 WC Limnology; Oceanography SC Marine & Freshwater Biology; Oceanography GA 382QX UT WOS:000165834700010 ER PT J AU Kortzinger, A Mintrop, L Wallace, DWR Johnson, KM Neill, C Tilbrook, B Towler, P Inoue, HY Ishii, M Shaffer, G Saavedra, RFT Ohtaki, E Yamashita, E Poisson, A Brunet, C Schauer, B Goyet, C Eischeid, G AF Kortzinger, A Mintrop, L Wallace, DWR Johnson, KM Neill, C Tilbrook, B Towler, P Inoue, HY Ishii, M Shaffer, G Saavedra, RFT Ohtaki, E Yamashita, E Poisson, A Brunet, C Schauer, B Goyet, C Eischeid, G TI The international at-sea intercomparison of fCO(2) systems during the R/V Meteor Cruise 36/1 in the North Atlantic Ocean SO MARINE CHEMISTRY LA English DT Article; Proceedings Paper CT 2nd International Symposium on Carbon Dioxide in the Oceans CY JAN 18-22, 1999 CL TSUKUBA CTR INST, TSUKUBA, JAPAN HO TSUKUBA CTR INST DE carbon cycle; air-sea exchange; carbon dioxide partial pressure; intercomparison ID DISSOCIATION-CONSTANTS; CARBONIC-ACID; PARTIAL-PRESSURE; CO2; SEAWATER; WATER; TEMPERATURE; PCO(2); SALINITY; AIR AB The 'International Intercomparison Exercise of fCO(2) Systems' was carried out in 1996 during the R/V Meteor Cruise 36/1 from Bermuda/UK to Gran Canaria/Spain. Nine groups from six countries (Australia, Denmark, France, Germany, Japan, USA) participated in this exercise, bringing together 15 participants with seven underway fugacity of carbon dioxide (fCO(2)) systems, one discrete fCO(2) system, and two underway pH systems, as well as systems for discrete measurement of total alkalinity and total dissolved inorganic carbon. Here, we compare surface seawater fCO(2) measured synchronously by all participating instruments. A common infrastructure (seawater and calibration gas supply), different quality checks (performance of calibration procedures for CO2, temperature measurements) and a common procedure for calculation of final fCO(2) were provided to reduce the largest possible amount of controllable sources of error. The results show that under such conditions underway measurements of the fCO(2) in surface seawater and overlying air can be made to a high degree of agreement(+/-1 mu atm) with a variety of possible equilibrator and system designs. Also, discrete fCO(2) measurements can be made in good agreement (+/-3 mu atm) with underway fCO(2) data sets. However, even well-designed systems, which are operated without any obvious sign of malfunction, can show significant differences of the order of 10 mu atm. Based on our results, no "best choice" for the type of the equilibrator nor specifics on its dimensions and flow rates of seawater and air can be made in regard to the achievable accuracy of the fCO(2) system. Measurements of equilibrator temperature do not seem to be made with the required accuracy resulting in significant errors in fCO(2) results. Calculation of fCO(2) from high-quality total dissolved inorganic carbon (C-T) and total alkalinity (A(T)) measurements does not yield results comparable in accuracy and precision to fCO(2) measurements. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Univ Kiel, Inst Marine Res, Dept Marine Chem, D-24105 Kiel, Germany. Univ Bremen, Dept Geosci, D-28334 Bremen, Germany. Brookhaven Natl Lab, Dept Appl Sci, Upton, NY 11973 USA. Cooperat Res Ctr Antarctic & So Ocean, Div Marine Res, Hobart, Tas 7001, Australia. Commonwealth Sci & Ind Res Org, Hobart, Tas 7001, Australia. Meteorol Res Inst, Geochem Res Dept, Tsukuba, Ibaraki 305, Japan. Univ Copenhagen, Danish Ctr Earth Syst Sci, DK-2100 Copenhagen, Denmark. Gothenburg Univ, Dept Analyt & Marine Chem, S-41296 Gothenburg, Sweden. Okayama Univ, Okayama 700, Japan. Okayama Univ Sci, Res Inst Technol, Okayama 700, Japan. Univ Paris 06, Phys & Chim Marines Lab, F-75252 Paris 05, France. Woods Hole Oceanog Inst, Dept Marine Chem & Geochem, Woods Hole, MA 02543 USA. RP Kortzinger, A (reprint author), Univ Kiel, Inst Marine Res, Dept Marine Chem, Dusternbrooker Weg 20, D-24105 Kiel, Germany. RI Yoshikawa, Hisayuki/A-4056-2012; Kortzinger, Arne/A-4141-2014; Tilbrook, Bronte/A-1522-2012; Shaffer, Gary/G-1742-2016 OI Yoshikawa, Hisayuki/0000-0002-9936-2188; Kortzinger, Arne/0000-0002-8181-3593; Tilbrook, Bronte/0000-0001-9385-3827; Shaffer, Gary/0000-0002-2494-3471 NR 32 TC 44 Z9 48 U1 2 U2 10 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0304-4203 J9 MAR CHEM JI Mar. Chem. PD DEC PY 2000 VL 72 IS 2-4 BP 171 EP 192 DI 10.1016/S0304-4203(00)00080-3 PG 22 WC Chemistry, Multidisciplinary; Oceanography SC Chemistry; Oceanography GA 381AP UT WOS:000165740400008 ER PT J AU Walter, PL AF Walter, PL TI Dynamic force, pressure, and acceleration - Part 10: Data utilization SO MEASUREMENTS & CONTROL LA English DT Article AB The goal of recording valid dynamic force, pressure, or acceleration data is either to enable control of a process or system or to support design and analysis. This part begins to discuss some of the ways in which we use successfully recorded data. C1 Sandia Natl Labs, Livermore, CA 94550 USA. Texas Christian Univ, Dept Engn, Ft Worth, TX 76129 USA. RP Walter, PL (reprint author), Sandia Natl Labs, Livermore, CA 94550 USA. NR 4 TC 0 Z9 0 U1 0 U2 0 PU MEASUREMENTS & DATA CORP PI PITTSBURGH PA 2994 W LIBERTY AVE, PITTSBURGH, PA 15216 USA SN 0148-0057 J9 MEAS CONTROL-US JI Meas. Control PD DEC PY 2000 IS 203 BP 59 EP 66 PG 8 WC Automation & Control Systems; Instruments & Instrumentation SC Automation & Control Systems; Instruments & Instrumentation GA 400MW UT WOS:000166876500003 ER PT J AU Gavriljuk, VG Glavatska, NI Petrov, YN Bojnitska, IM Rawers, JC AF Gavriljuk, VG Glavatska, NI Petrov, YN Bojnitska, IM Rawers, JC TI Structure and mechanical properties of cold worked nitrogen austenitic steels SO METALLOFIZIKA I NOVEISHIE TEKHNOLOGII LA English DT Article DE nitrogen steels; cold work hardening; stacking fault energy; twinning; dislocations; substructure; martensite ID STACKING-FAULT ENERGY; STAINLESS-STEELS; FCC METALS; BEHAVIOR; ALLOYS; SLIP AB Effect of nitrogen on the structure and cold work hardening of austenitic steels Cr18Ni16Mn10 and Cr15Mn17 having different values of stacking fault energy (SFE) and, correspondingly, different stability to the strain-induced phase transformations has been studied using transmission electron microscopy and mechanical tests. Cold rolling was used as a way of plastic deformation. Steel Cr18Ni16Mn10 is essentially stable against the gamma-->epsilon transformation, while the strain-induced epsilon martensite is formed in steel Cr15Mn17. Alloying by nitrogen stabilises the gamma phase. If is shown that nitrogen affects the SFE in the studied steels non-monotonously and in opposite directions with a maximum at 0.4 mass% of N in steel Cr18Ni16Mn10 and with a minimum at 0.48 mass% of N in steel Cr15Mn17. Twinning is more pronounced in steels with the lower value of SFE, however twins having been formed are eroded at higher strains. Twinning and slip contribute concurrently to the plastic deformation and substitute each other in the course of deformation. In contrast to previous studies, no distinguishable contribution of nitrogen to the cold work hardening is found in both steels. The interpretation is proposed based on the diminished contribution of twinning to the plastic deformation in steel Cr18Ni16Mn10 and on the counterbalance between twining and strain-induced epsilon martensite in steel Cr15Mn17 with increasing nitrogen content. C1 NASU, GV Kurdyumov Inst Met Phys, UA-03680 Kyyiv 142, Ukraine. US Dept Energy, Albany, OR 97321 USA. RP Gavriljuk, VG (reprint author), NASU, GV Kurdyumov Inst Met Phys, 36 Acad Vernadsky Blvd, UA-03680 Kyyiv 142, Ukraine. NR 19 TC 1 Z9 1 U1 1 U2 2 PU NATL ACAD SCIENCES UKRAINE, INST METAL PHYSICS PI KIEV 142 PA 36 ACADEMICIAN VERNADSKY BLVD, KIEV 142, UKRAINE UA-252180 SN 0204-3580 J9 METALLOFIZ NOV TEKH+ JI Metallofiz. Nov. Tekhnol.-Met. Phys. Adv. Techn. PD DEC PY 2000 VL 22 IS 12 BP 47 EP 55 PG 9 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering; Physics, Condensed Matter SC Materials Science; Metallurgy & Metallurgical Engineering; Physics GA 392VA UT WOS:000166432200008 ER PT J AU Frueh, C Poirier, DR Felicelli, SD AF Frueh, C Poirier, DR Felicelli, SD TI Effect of computational domain size on the mathematical modeling of transport processes and segregation during directional solidification SO METALLURGICAL AND MATERIALS TRANSACTIONS A-PHYSICAL METALLURGY AND MATERIALS SCIENCE LA English DT Article ID PB-SN ALLOYS; BINARY-ALLOYS; DENDRITIC SOLIDIFICATION; MACROSEGREGATION; CONSERVATION; SIMULATION; FRECKLES AB Using a finite-element simulator, a directionally solidified hypoeutectic Pb-Sn alloy was modeled in two dimensions to determine the effect of the height of the overlying liquid on convective transport and macrosegregation. It was determined that, while the strength of the convection in the overlying liquid depends on the square root of its height, one need not model the entire domain to predict freckling. Furthermore, the assumption of a constant thermal gradient in the liquid causes the predicted convection to be somewhat weaker than the convection in the temperature field used in directional solidification processing. C1 Sandia Natl Labs, Mech Reliabil & Melting Dept, Albuquerque, NM 87185 USA. Univ Arizona, Dept Mat Sci & Engn, Tucson, AZ 85721 USA. Ctr Atom Bariloche, RA-8400 Bariloche, Rio Negro, Argentina. RP Frueh, C (reprint author), Sandia Natl Labs, Mech Reliabil & Melting Dept, POB 5800, Albuquerque, NM 87185 USA. NR 16 TC 8 Z9 8 U1 0 U2 4 PU MINERALS METALS MATERIALS SOC PI WARRENDALE PA 184 THORN HILL RD, WARRENDALE, PA 15086 USA SN 1073-5623 J9 METALL MATER TRANS A JI Metall. Mater. Trans. A-Phys. Metall. Mater. Sci. PD DEC PY 2000 VL 31 IS 12 BP 3129 EP 3135 DI 10.1007/s11661-000-0092-4 PG 7 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA 421AA UT WOS:000168037800015 ER PT J AU Palmer, TA Debroy, T AF Palmer, TA Debroy, T TI Numerical modeling of enhanced nitrogen dissolution during gas tungsten arc welding SO METALLURGICAL AND MATERIALS TRANSACTIONS B-PROCESS METALLURGY AND MATERIALS PROCESSING SCIENCE LA English DT Article ID MOVING HEAT-SOURCE; THERMODYNAMIC PROPERTIES; PARTITION FUNCTIONS; PLASMA ENVIRONMENT; METAL; IRON; ABSORPTION; TEMPERATURE; HYDROGEN; OXYGEN AB Weld-metal nitrogen concentrations far in excess of Sieverts-Iaw calculations during gas tungsten are (GTA) welding of iron are investigated both experimentally and theoretically. A transient, three dimensional mathematical model has been developed to calculate the residual nitrogen concentrations during GTA welding. This mode, combines calculations for the plasma phase with those for nitrogen absorption and for the transport of nitrogen by convection and diffusion in the weld metal and diffusion throughout the weldment. In addition, the model takes into account the roles of turbulence and the nitrogen desorption reaction in affecting the residual nitrogen concentration in the weldment. Autogeneous GTA welding experiments in pure iron have been performed and the resulting nitrogen concentrations compared with the modeling results. Both experimental and modeled nitrogen concentrations fall in a range between 2.7 and 4.7 times higher than Sieverts-law calculations at a temperature of 2000 K. Modeled nitrogen concentrations correlate well with the experimental results, both in magnitude and in the general trends, with changes in the travel speed and nitrogen addition to the shielding gas. C1 Penn State Univ, Dept Mat Sci & Engn, University Pk, PA 16802 USA. RP Palmer, TA (reprint author), Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. RI DebRoy, Tarasankar/A-2106-2010 NR 65 TC 25 Z9 25 U1 1 U2 7 PU SPRINGER PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 1073-5615 J9 METALL MATER TRANS B JI Metall. Mater. Trans. B-Proc. Metall. Mater. Proc. Sci. PD DEC PY 2000 VL 31 IS 6 BP 1371 EP 1385 DI 10.1007/s11663-000-0023-1 PG 15 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA 386FR UT WOS:000166050600023 ER PT J AU Kim, IS Okuda, T Kang, CY Sung, JH Maziasz, PJ Klueh, RL Miyahara, K AF Kim, IS Okuda, T Kang, CY Sung, JH Maziasz, PJ Klueh, RL Miyahara, K TI Effect of oxide species and thermomechanical treatments on the strength properties of mechanically alloyed Fe-17% Cr ferritic ODS materials SO METALS AND MATERIALS-KOREA LA English DT Article DE ferritic alloy; mechanical alloying oxide dispersion strengthening; ODS; yttria; zirconia; magnesia; high temperature strength; thermomechanical treatment ID RECRYSTALLIZATION AB The effects of several oxide species, such as Y2O3, ZrO2 and MgO, and the thermomechanical treatment (TMT) after the mechanical alloying (MA) process on the strength properties of Fe-17%Cr ferritic ODS (oxide dispersion strengthening) MA materials were investigated. Y2O3 showed the most uniform dispersion of the finest particles among the above oxides, but the microstructural evolution during the TMT had a larger effect on the strengthening of the alloys than the fine and uniform dispersion of the Y2O3 particles had. C1 Nagoya Univ, Grad Sch, Nagoya, Aichi 4648603, Japan. Kobe Steel Ltd, Mat Res Inst, Kobe, Hyogo 6512271, Japan. Pukyung Natl Univ, Dept Mat Sci & Engn, Pusan 608739, South Korea. Dong A Univ, Dept Met Engn, Pusan 604714, South Korea. Oak Ridge Natl Lab, Div Met & Ceram, Oak Ridge, TN 37831 USA. Nagoya Univ, Dept Mol Design & Engn, Nagoya, Aichi 4648603, Japan. RP Kim, IS (reprint author), Nagoya Univ, Grad Sch, Nagoya, Aichi 4648603, Japan. OI Maziasz, Philip/0000-0001-8207-334X NR 8 TC 16 Z9 17 U1 1 U2 9 PU KOREAN INST METALS MATERIALS PI SEOUL PA POSCO CENTER, 4TH FL (EAST WING), 892 DAECHI-4-DONG, KANGNAM-KU, SEOUL 135-777, SOUTH KOREA SN 1225-9438 J9 MET MATER-KOREA JI Met. Mater.-Korea PD DEC PY 2000 VL 6 IS 6 BP 513 EP 518 PG 6 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA 385XW UT WOS:000166031300004 ER PT J AU Thoma, SG Nenoff, TM AF Thoma, SG Nenoff, TM TI Vapor phase transport synthesis of zeolites from sol-gel precursors SO MICROPOROUS AND MESOPOROUS MATERIALS LA English DT Article DE zeolite crystallization; vapor phase transport; gel structure ID PURE-SILICA ZEOLITES; STRUCTURE DIRECTION; MFI ZEOLITE; CRYSTALLIZATION; NMR; CONVERSION; MECHANISM; SYSTEM; AMINES; ZSM-5 AB A study of zeolite crystallization from sol-gel precursors using the vapor phase transport synthesis method has been performed. Zeolites (ZSM-5, ZSM-48, zeolite P, and sodalite) were crystallized by contacting vapor phase organic or organic-water mixtures with dried sodium silicate and dried sodium alumino-silicate gels. For each precursor gel, a ternary phase system of vapor phase organic reactant molecules was explored. The vapor phase reactant mixtures ranged from pure ethylene diamine, triethylamine, or water, to an equimolar mixture of each. In addition, a series of gels with varied physical and chemical properties were crystallized using the same vapor phase solvent mixture for each gel. The precursor gels and the crystalline products were analyzed via scanning electron microscopy, electron dispersive spectroscopy, X-ray mapping, powder X-ray diffraction, nitrogen surface area, Fourier transform infrared spectroscopy, and thermal analyses. The product phase and purity as a function of the solvent mixture, precursor gel structure, and precursor gel chemistry is discussed. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Sandia Natl Labs, Dept Catalysis & Chem Technol, Albuquerque, NM 87185 USA. RP Nenoff, TM (reprint author), Sandia Natl Labs, Dept Catalysis & Chem Technol, POB 5800,MS 0710, Albuquerque, NM 87185 USA. NR 23 TC 24 Z9 27 U1 5 U2 23 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 DEC PY 2000 VL 41 IS 1-3 BP 295 EP 305 DI 10.1016/S1387-1811(00)00306-1 PG 11 WC Chemistry, Applied; Chemistry, Physical; Nanoscience & Nanotechnology; Materials Science, Multidisciplinary SC Chemistry; Science & Technology - Other Topics; Materials Science GA 380KT UT WOS:000165701600025 ER PT J AU Pollock, DD Eisen, JA Doggett, NA Cummings, MP AF Pollock, DD Eisen, JA Doggett, NA Cummings, MP TI A case for evolutionary genomics and the comprehensive examination of sequence biodiversity SO MOLECULAR BIOLOGY AND EVOLUTION LA English DT Review DE evolutionary genomics; genomic biodiversity; functional genomics; comparative genomics; molecular evolution ID COMPLETE NUCLEOTIDE-SEQUENCE; MITOCHONDRIAL-DNA SEQUENCE; PROTEIN SECONDARY STRUCTURE; NEUTRAL MOLECULAR VARIATION; CYTOCHROME-C-OXIDASE; AMINO-ACID-SEQUENCES; MAXIMUM-LIKELIHOOD; GENE ORGANIZATION; CRYSTAL-STRUCTURE; ESCHERICHIA-COLI AB Comparative analysis is one of the most powerful methods available for understanding the diverse and complex systems found in biology, but it is often limited by a lack of comprehensive taxonomic sampling. Despite the recent development of powerful genome technologies capable of producing sequence data in large quantities (witness the recently completed first draft of the human genome), there has been relatively little change in how evolutionary studies are conducted. The application of genomic methods to evolutionary biology is a challenge, in part because gene segments from different organisms are manipulated separately, requiring individual purification, cloning, and sequencing. We suggest that a feasible approach to collecting genome-scale data sets for evolutionary biology (i.e., evolutionary genomics) may consist of combination of DNA samples prior to cloning and sequencing, followed by computational reconstruction of the original sequences. This approach will allow the full benefit of automated protocols developed by genome projects to be realized; taxon sampling levels can easily increase to thousands for targeted genomes and genomic regions. Sequence diversity at this level will dramatically improve the quality and accuracy of phylogenetic inference, as well as the accuracy and resolution of comparative evolutionary studies. In particular, it will be possible to make accurate estimates of normal evolution in the context of constant structural and functional constraints (i.e., site-specific substitution probabilities), along with accurate estimates of changes in evolutionary patterns, including pairwise coevolution between sites, adaptive bursts, and changes in selective constraints. These estimates can then be used to understand and predict the effects of protein structure and function on sequence evolution and to predict unknown details of protein structure, function, and functional divergence. In order to demonstrate the practicality of these ideas and the potential benefit for functional genomic analysis, we describe a pilot project we are conducting to simultaneously sequence large numbers of vertebrate mitochondrial genomes. C1 Los Alamos Natl Lab, Div Theoret, Los Alamos, NM USA. Louisiana State Univ, Dept Biol Sci, Baton Rouge, LA 70803 USA. Inst Genomic Res, Gaithersburg, MD USA. Los Alamos Natl Lab, Biosci Div, Genom Grp, Los Alamos, NM USA. Marine Biol Lab, Josephine Bay Paul Ctr Comparat Mol Biol & Evolut, Woods Hole, MA 02543 USA. RP Louisiana State Univ, Dept Biol Sci, Baton Rouge, LA 70803 USA. EM daviddpollock@yahoo.com RI Pollock, David/M-4740-2016 OI Pollock, David/0000-0002-7627-4214 NR 113 TC 48 Z9 53 U1 1 U2 4 PU OXFORD UNIV PRESS PI OXFORD PA GREAT CLARENDON ST, OXFORD OX2 6DP, ENGLAND SN 0737-4038 EI 1537-1719 J9 MOL BIOL EVOL JI Mol. Biol. Evol. PD DEC PY 2000 VL 17 IS 12 BP 1776 EP 1788 PG 13 WC Biochemistry & Molecular Biology; Evolutionary Biology; Genetics & Heredity SC Biochemistry & Molecular Biology; Evolutionary Biology; Genetics & Heredity GA 386GE UT WOS:000166051900002 PM 11110893 ER PT J AU Pollock, DD Bruno, WJ AF Pollock, DD Bruno, WJ TI Assessing an unknown evolutionary process: Effect of increasing site-specific knowledge through taxon addition SO MOLECULAR BIOLOGY AND EVOLUTION LA English DT Article DE evolutionary models; maximum likelihood; rate variation; taxon addition; phylogenetic inference ID MAXIMUM-LIKELIHOOD; PHYLOGENETIC METHODS; PROTEIN RESIDUES; ACCURACY; PARSIMONY; INCONSISTENCY; PERFORMANCE; BIAS AB Assessment of the evolutionary process is crucial for understanding the effect of protein structure and function on sequence evolution and for many other analyses in molecular evolution. Here, we used simulations to study how taxon sampling affects accuracy of parameter estimation and topological inference in the absence of branch length asymmetry. With maximum-likelihood analysis, we find that adding taxa dramatically improves both support for the evolutionary model and accurate assessment of its parameters when compared with increasing the sequence length. Using a method we call "doppelganger trees," we distinguish the contributions of two sources of improved topological inference: greater knowledge about internal nodes and greater knowledge of site-specific rate parameters. Surprisingly, highly significant support for the correct general model does not lead directly to improved topological inference. Instead, substantial improvement occurs only with accurate assessment of the evolutionary process at individual sites. Although these results are based on a simplified model of the evolutionary process, they indicate that in general, assuming processes are not independent and identically distributed among sites, more extensive sampling of taxonomic biodiversity will greatly improve analytical results in many current sequence data sets with moderate sequence lengths. C1 Louisiana State Univ, Dept Biol Sci, Baton Rouge, LA 70803 USA. Univ Calif Los Alamos Natl Lab, Los Alamos, NM USA. RP Pollock, DD (reprint author), Louisiana State Univ, Dept Biol Sci, Baton Rouge, LA 70803 USA. RI Pollock, David/M-4740-2016 OI Pollock, David/0000-0002-7627-4214 NR 26 TC 46 Z9 47 U1 0 U2 3 PU SOC MOLECULAR BIOLOGY EVOLUTION PI LAWRENCE PA PO BOX 1897, LAWRENCE, KS 66044-8897 USA SN 0737-4038 J9 MOL BIOL EVOL JI Mol. Biol. Evol. PD DEC PY 2000 VL 17 IS 12 BP 1854 EP 1858 PG 5 WC Biochemistry & Molecular Biology; Evolutionary Biology; Genetics & Heredity SC Biochemistry & Molecular Biology; Evolutionary Biology; Genetics & Heredity GA 386GE UT WOS:000166051900010 PM 11110901 ER PT J AU Ewan, KB Wakefield, L Shyamala, WG Barcellos-Hoff, MH AF Ewan, KB Wakefield, L Shyamala, WG Barcellos-Hoff, MH TI The mammary phenotype of TGF-beta 1 null heterozygotes indicates that TGF-beta actively restrains ovarian steroid hormone-induced proliferation SO MOLECULAR BIOLOGY OF THE CELL LA English DT Meeting Abstract C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Div Life Sci, Berkeley, CA 94720 USA. NCI, Bethesda, MD 20892 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER SOC CELL BIOLOGY PI BETHESDA PA 8120 WOODMONT AVE, STE 750, BETHESDA, MD 20814-2755 USA SN 1059-1524 J9 MOL BIOL CELL JI Mol. Biol. Cell PD DEC PY 2000 VL 11 SU S MA 140 BP 27A EP 27A PG 1 WC Cell Biology SC Cell Biology GA 377QY UT WOS:000165525900141 ER PT J AU Weaver, VM Lelievre, S Lakins, JN Jones, J Giancotti, F Bissell, MJ AF Weaver, VM Lelievre, S Lakins, JN Jones, J Giancotti, F Bissell, MJ TI Beta 4-integrins induce polarity and apoptosis resistance in mammary tissue structures SO MOLECULAR BIOLOGY OF THE CELL LA English DT Meeting Abstract C1 Univ Penn, Philadelphia, PA 19104 USA. Univ Penn, Inst Med & Engn, Philadelphia, PA 19104 USA. Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. Northwestern Univ, Evanston, IL 60208 USA. Mem Sloan Kettering Canc Ctr, New York, NY 10021 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER SOC CELL BIOLOGY PI BETHESDA PA 8120 WOODMONT AVE, STE 750, BETHESDA, MD 20814-2755 USA SN 1059-1524 J9 MOL BIOL CELL JI Mol. Biol. Cell PD DEC PY 2000 VL 11 SU S MA 272 BP 52A EP 52A PG 1 WC Cell Biology SC Cell Biology GA 377QY UT WOS:000165525900273 ER PT J AU Wallingford, JB Rowning, RA Vogeli, KM Rothbacher, U Fraser, SE Harland, RM AF Wallingford, JB Rowning, RA Vogeli, KM Rothbacher, U Fraser, SE Harland, RM TI Dishevelled controls cell polarity and motility during Xenopus gastrulation SO MOLECULAR BIOLOGY OF THE CELL LA English DT Meeting Abstract C1 Univ Calif Berkeley, Berkeley, CA 94720 USA. Lawrence Berkeley Natl Lab, Berkeley, CA USA. CALTECH, Pasadena, CA 91125 USA. NR 0 TC 0 Z9 0 U1 0 U2 1 PU AMER SOC CELL BIOLOGY PI BETHESDA PA 8120 WOODMONT AVE, STE 750, BETHESDA, MD 20814-2755 USA SN 1059-1524 J9 MOL BIOL CELL JI Mol. Biol. Cell PD DEC PY 2000 VL 11 SU S MA 769 BP 148A EP 148A PG 1 WC Cell Biology SC Cell Biology GA 377QY UT WOS:000165525900772 ER PT J AU Inclan, YF Nogales, E AF Inclan, YF Nogales, E TI Structural models for the self-assembly and microtubule interactions of gamma-, delta-, and epsilon-tubulin SO MOLECULAR BIOLOGY OF THE CELL LA English DT Meeting Abstract C1 Lawrence Berkeley Natl Lab, Div Life Sci, Berkeley, CA 94720 USA. Univ Calif Berkeley, Berkeley, CA 94720 USA. NR 4 TC 0 Z9 0 U1 0 U2 0 PU AMER SOC CELL BIOLOGY PI BETHESDA PA 8120 WOODMONT AVE, STE 750, BETHESDA, MD 20814-2755 USA SN 1059-1524 J9 MOL BIOL CELL JI Mol. Biol. Cell PD DEC PY 2000 VL 11 SU S MA 979 BP 188A EP 188A PG 1 WC Cell Biology SC Cell Biology GA 377QY UT WOS:000165525900983 ER PT J AU Qazi, U Niederstrasser, H Nogales, E AF Qazi, U Niederstrasser, H Nogales, E TI Toward the structural basis of microtubule dynamics: Electron microscopy and reconstruction of Tubulin-GDP rings SO MOLECULAR BIOLOGY OF THE CELL LA English DT Meeting Abstract C1 Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. Univ Calif Berkeley, Berkeley, CA 94720 USA. NR 2 TC 0 Z9 0 U1 0 U2 0 PU AMER SOC CELL BIOLOGY PI BETHESDA PA 8120 WOODMONT AVE, STE 750, BETHESDA, MD 20814-2755 USA SN 1059-1524 J9 MOL BIOL CELL JI Mol. Biol. Cell PD DEC PY 2000 VL 11 SU S MA 978 BP 188A EP 188A PG 1 WC Cell Biology SC Cell Biology GA 377QY UT WOS:000165525900982 ER PT J AU Bielicki, JK Brushia, RJ Forte, TM AF Bielicki, JK Brushia, RJ Forte, TM TI Structure/function studies of human paraoxonase: evidence that glycosylation is not required for the antioxidant activity of the enzyme SO MOLECULAR BIOLOGY OF THE CELL LA English DT Meeting Abstract C1 Lawrence Berkeley Lab, Div Life Sci, Berkeley, CA 94720 USA. Lawrence Berkeley Lab, Berkeley, CA 94720 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER SOC CELL BIOLOGY PI BETHESDA PA 8120 WOODMONT AVE, STE 750, BETHESDA, MD 20814-2755 USA SN 1059-1524 J9 MOL BIOL CELL JI Mol. Biol. Cell PD DEC PY 2000 VL 11 SU S MA 1218 BP 233A EP 234A PG 2 WC Cell Biology SC Cell Biology GA 377QY UT WOS:000165525901221 ER PT J AU Anders, M Hansen, RK McCormick, F Bissell, MJ Korn, WM AF Anders, M Hansen, RK McCormick, F Bissell, MJ Korn, WM TI The expression of the human Coxsackie and Adenovirus receptor (CAR) depends on the three-dimensional organization of epithelial cells. SO MOLECULAR BIOLOGY OF THE CELL LA English DT Meeting Abstract C1 Univ Calif San Francisco, San Francisco, CA 94143 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. Univ Calif San Francisco, Dept Med, Div Gastroenterol, San Francisco, CA 94143 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER SOC CELL BIOLOGY PI BETHESDA PA 8120 WOODMONT AVE, STE 750, BETHESDA, MD 20814-2755 USA SN 1059-1524 J9 MOL BIOL CELL JI Mol. Biol. Cell PD DEC PY 2000 VL 11 SU S MA 1274 BP 245A EP 245A PG 1 WC Cell Biology SC Cell Biology GA 377QY UT WOS:000165525901278 ER PT J AU Taunton, J Coughlin, ML Rowning, BA Wu, M Moon, RT Mitchison, TJ Larabell, CA AF Taunton, J Coughlin, ML Rowning, BA Wu, M Moon, RT Mitchison, TJ Larabell, CA TI Actin-dependent propulsion of endosomes and lysosomes by activation of the Cdc42/RhoGDI complex SO MOLECULAR BIOLOGY OF THE CELL LA English DT Meeting Abstract C1 Univ Calif San Francisco, San Francisco, CA 94143 USA. Harvard Univ, Boston, MA 02115 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. Univ Calif Berkeley, Berkeley, CA 94720 USA. Univ Washington, Seattle, WA 98195 USA. NR 0 TC 0 Z9 0 U1 0 U2 1 PU AMER SOC CELL BIOLOGY PI BETHESDA PA 8120 WOODMONT AVE, STE 750, BETHESDA, MD 20814-2755 USA SN 1059-1524 J9 MOL BIOL CELL JI Mol. Biol. Cell PD DEC PY 2000 VL 11 SU S MA 1999 BP 385A EP 385A PG 1 WC Cell Biology SC Cell Biology GA 377QY UT WOS:000165525902003 ER PT J AU An, XL Gascard, PD Narla, M Takakuwa, Y Manno, S AF An, XL Gascard, PD Narla, M Takakuwa, Y Manno, S TI Characterization of 4.1R interaction with phosphatidylserine SO MOLECULAR BIOLOGY OF THE CELL LA English DT Meeting Abstract C1 LBNL, Div Life Sci, Dept Subcellular Struct, Berkeley, CA 94720 USA. Tokyo Womens Med Univ, Tokyo, Japan. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER SOC CELL BIOLOGY PI BETHESDA PA 8120 WOODMONT AVE, STE 750, BETHESDA, MD 20814-2755 USA SN 1059-1524 J9 MOL BIOL CELL JI Mol. Biol. Cell PD DEC PY 2000 VL 11 SU S MA 2010 BP 387A EP 387A PG 1 WC Cell Biology SC Cell Biology GA 377QY UT WOS:000165525902014 ER PT J AU Pinder, JC Hayes, NVL Taylor-Harris, PM Gascard, PD Maggs, AM Baines, AJ AF Pinder, JC Hayes, NVL Taylor-Harris, PM Gascard, PD Maggs, AM Baines, AJ TI 4.1 proteins in heart SO MOLECULAR BIOLOGY OF THE CELL LA English DT Meeting Abstract C1 Kings Coll London, MRC, Muscle & Cell Motil Unit, London SE1 1UL, England. Univ Kent, Biol Lab, Canterbury, Kent, England. LBNL, Div Life Sci, Dept Subcellular Struct, Berkeley, CA 94720 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER SOC CELL BIOLOGY PI BETHESDA PA 8120 WOODMONT AVE, STE 750, BETHESDA, MD 20814-2755 USA SN 1059-1524 J9 MOL BIOL CELL JI Mol. Biol. Cell PD DEC PY 2000 VL 11 SU S MA 2009 BP 387A EP 387A PG 1 WC Cell Biology SC Cell Biology GA 377QY UT WOS:000165525902013 ER PT J AU Schmeichel, KL Hansen, RK Liu, H Weaver, VM Bissell, MJ AF Schmeichel, KL Hansen, RK Liu, H Weaver, VM Bissell, MJ TI Regulation of EGFR and beta 1 integrin signal integration in human breast epithelial cells in 3-dimensions (3D) SO MOLECULAR BIOLOGY OF THE CELL LA English DT Meeting Abstract C1 Lawrence Berkeley Natl Lab, Div Life Sci, Berkeley, CA 94720 USA. Univ Penn, Philadelphia, PA 19104 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER SOC CELL BIOLOGY PI BETHESDA PA 8120 WOODMONT AVE, STE 750, BETHESDA, MD 20814-2755 USA SN 1059-1524 J9 MOL BIOL CELL JI Mol. Biol. Cell PD DEC PY 2000 VL 11 SU S MA 2061 BP 397A EP 397A PG 1 WC Cell Biology SC Cell Biology GA 377QY UT WOS:000165525902065 ER PT J AU Li, GH Sulkowski, GM Baer, LA Ronca, AE Wade, CE Sajdel-Sulkowska, EM AF Li, GH Sulkowski, GM Baer, LA Ronca, AE Wade, CE Sajdel-Sulkowska, EM TI Cerebellum development under altered gravity: expression of CD15 proteoglycans in the cerebellum of hypergravity-exposed rat neonates. SO MOLECULAR BIOLOGY OF THE CELL LA English DT Meeting Abstract C1 Harvard Univ, Brigham & Womens Hosp, Sch Med, Boston, MA 02115 USA. Harvard Univ, Sch Med, Boston, MA 02215 USA. NASA, Ames Res Ctr, Div Life Sci, Ames, IA 50011 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER SOC CELL BIOLOGY PI BETHESDA PA 8120 WOODMONT AVE, STE 750, BETHESDA, MD 20814-2755 USA SN 1059-1524 J9 MOL BIOL CELL JI Mol. Biol. Cell PD DEC PY 2000 VL 11 SU S MA 2071 BP 399A EP 399A PG 1 WC Cell Biology SC Cell Biology GA 377QY UT WOS:000165525902075 ER PT J AU MacInnes, MA LaRue, K Freyer, J Hudson, L Kusewitt, D AF MacInnes, MA LaRue, K Freyer, J Hudson, L Kusewitt, D TI Differentiation and enrichment of functional keratinocytes from mouse embryonic stem (ES) cells SO MOLECULAR BIOLOGY OF THE CELL LA English DT Meeting Abstract C1 Univ Calif Los Alamos Natl Lab, Biosci Div, Los Alamos, NM 87545 USA. Univ New Mexico, Albuquerque, NM 87131 USA. RI Kusewitt, Donna/E-8107-2011 NR 0 TC 0 Z9 0 U1 0 U2 1 PU AMER SOC CELL BIOLOGY PI BETHESDA PA 8120 WOODMONT AVE, STE 750, BETHESDA, MD 20814-2755 USA SN 1059-1524 J9 MOL BIOL CELL JI Mol. Biol. Cell PD DEC PY 2000 VL 11 SU S MA 2129 BP 410A EP 410A PG 1 WC Cell Biology SC Cell Biology GA 377QY UT WOS:000165525902133 ER PT J AU Muthuswamy, SK Li, DM Lelievre, S Bissell, MJ Brugge, JS AF Muthuswamy, SK Li, DM Lelievre, S Bissell, MJ Brugge, JS TI ErbB1 and ErbB2 receptors differ in their ability to induce cell proliferation and disrupt the polarized organization of mammary epithelial acini SO MOLECULAR BIOLOGY OF THE CELL LA English DT Meeting Abstract C1 Harvard Univ, Sch Med, Boston, MA 02115 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER SOC CELL BIOLOGY PI BETHESDA PA 8120 WOODMONT AVE, STE 750, BETHESDA, MD 20814-2755 USA SN 1059-1524 J9 MOL BIOL CELL JI Mol. Biol. Cell PD DEC PY 2000 VL 11 SU S MA 2228 BP 429A EP 429A PG 1 WC Cell Biology SC Cell Biology GA 377QY UT WOS:000165525902232 ER PT J AU Bianco, PR Brewer, LR Corzett, M Balhorn, R Yeh, Y Kowalczykowski, SC Baskin, RJ AF Bianco, PR Brewer, LR Corzett, M Balhorn, R Yeh, Y Kowalczykowski, SC Baskin, RJ TI Processive translocation and DNA unwinding by individual RecBCD enzyme molecules SO MOLECULAR BIOLOGY OF THE CELL LA English DT Meeting Abstract C1 Univ Calif Davis, Davis, CA 95616 USA. Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RI Brewer, Laurence/G-4056-2012 NR 0 TC 1 Z9 1 U1 0 U2 0 PU AMER SOC CELL BIOLOGY PI BETHESDA PA 8120 WOODMONT AVE, STE 750, BETHESDA, MD 20814-2755 USA SN 1059-1524 J9 MOL BIOL CELL JI Mol. Biol. Cell PD DEC PY 2000 VL 11 SU S MA 2274 BP 438A EP 438A PG 1 WC Cell Biology SC Cell Biology GA 377QY UT WOS:000165525902278 ER PT J AU Lelievre, SA Weaver, VM Larabell, CA Bissell, MJ AF Lelievre, SA Weaver, VM Larabell, CA Bissell, MJ TI Directing apoptosis from inside out: The supramolecular organization of NuMA is involved in cell survival. SO MOLECULAR BIOLOGY OF THE CELL LA English DT Meeting Abstract C1 Lawrence Berkeley Natl Lab, Div Life Sci, Berkeley, CA 94720 USA. Univ Penn, Philadelphia, PA 19104 USA. NR 0 TC 0 Z9 0 U1 0 U2 1 PU AMER SOC CELL BIOLOGY PI BETHESDA PA 8120 WOODMONT AVE, STE 750, BETHESDA, MD 20814-2755 USA SN 1059-1524 J9 MOL BIOL CELL JI Mol. Biol. Cell PD DEC PY 2000 VL 11 SU S MA 2296 BP 442A EP 442A PG 1 WC Cell Biology SC Cell Biology GA 377QY UT WOS:000165525902300 ER PT J AU Garbe, JC Wigington, D Nijjar, T Swisshelm, K Yaswen, P Stampfer, MR AF Garbe, JC Wigington, D Nijjar, T Swisshelm, K Yaswen, P Stampfer, MR TI Loss of p53 function in human mammary epithelial cells accelerates conversion to immortality SO MOLECULAR BIOLOGY OF THE CELL LA English DT Meeting Abstract C1 Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Div Life Sci, Berkeley, CA 94720 USA. Univ Washington, Seattle, WA 98195 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER SOC CELL BIOLOGY PI BETHESDA PA 8120 WOODMONT AVE, STE 750, BETHESDA, MD 20814-2755 USA SN 1059-1524 J9 MOL BIOL CELL JI Mol. Biol. Cell PD DEC PY 2000 VL 11 SU S MA 2377 BP 458A EP 458A PG 1 WC Cell Biology SC Cell Biology GA 377QY UT WOS:000165525902381 ER PT J AU Olsen, CL Yaswen, P Stampfer, MR AF Olsen, CL Yaswen, P Stampfer, MR TI Growth effects of oncogenic Raf-1 on finite lifespan and immortal cultured human mammary epithelial cells (HMEC) SO MOLECULAR BIOLOGY OF THE CELL LA English DT Meeting Abstract C1 Lawrence Berkeley Natl Lab, Div Life Sci, Berkeley, CA 94720 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER SOC CELL BIOLOGY PI BETHESDA PA 8120 WOODMONT AVE, STE 750, BETHESDA, MD 20814-2755 USA SN 1059-1524 J9 MOL BIOL CELL JI Mol. Biol. Cell PD DEC PY 2000 VL 11 SU S MA 2392 BP 460A EP 461A PG 2 WC Cell Biology SC Cell Biology GA 377QY UT WOS:000165525902396 ER PT J AU Muschler, JL Levy, D Campbell, K Bissell, MJ AF Muschler, JL Levy, D Campbell, K Bissell, MJ TI Dystroglycan facilitates correct morphogenesis in mammary epithelial cells and is highly variable among tumor cell lines. SO MOLECULAR BIOLOGY OF THE CELL LA English DT Meeting Abstract C1 Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. Univ Iowa, Iowa City, IA 52242 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER SOC CELL BIOLOGY PI BETHESDA PA 8120 WOODMONT AVE, STE 750, BETHESDA, MD 20814-2755 USA SN 1059-1524 J9 MOL BIOL CELL JI Mol. Biol. Cell PD DEC PY 2000 VL 11 SU S MA 2468 BP 476A EP 476A PG 1 WC Cell Biology SC Cell Biology GA 377QY UT WOS:000165525902472 ER PT J AU Henshall-Powell, RL Park, CC Bissell, MJ Barcellos-Hoff, MH AF Henshall-Powell, RL Park, CC Bissell, MJ Barcellos-Hoff, MH TI Three-dimensional (3D) cultures of human mammary epithelial cells treated with low-dose radiation and transforming growth factor-beta (TGF beta) exhibit altered cell-cell and cell-extracellular matrix interactions. SO MOLECULAR BIOLOGY OF THE CELL LA English DT Meeting Abstract C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Dept Cell & Mol Biol, Div Life Sci, Berkeley, CA 94720 USA. Univ Calif San Francisco, San Francisco, CA 94143 USA. NR 0 TC 0 Z9 0 U1 0 U2 2 PU AMER SOC CELL BIOLOGY PI BETHESDA PA 8120 WOODMONT AVE, STE 750, BETHESDA, MD 20814-2755 USA SN 1059-1524 J9 MOL BIOL CELL JI Mol. Biol. Cell PD DEC PY 2000 VL 11 SU S MA 2485 BP 479A EP 480A PG 2 WC Cell Biology SC Cell Biology GA 377QY UT WOS:000165525902489 ER PT J AU Corzett, MH Mazrimas, J Lee, C Balhorn, R AF Corzett, MH Mazrimas, J Lee, C Balhorn, R TI Protamine 1 : protamine 2 stochiometry in the sperm of eutherian mammals SO MOLECULAR BIOLOGY OF THE CELL LA English DT Meeting Abstract C1 Univ Calif Lawrence Livermore Natl Lab, Biol & Biotechnol Res Program, Livermore, CA 94550 USA. NR 0 TC 0 Z9 0 U1 1 U2 2 PU AMER SOC CELL BIOLOGY PI BETHESDA PA 8120 WOODMONT AVE, STE 750, BETHESDA, MD 20814-2755 USA SN 1059-1524 J9 MOL BIOL CELL JI Mol. Biol. Cell PD DEC PY 2000 VL 11 SU S MA 2686 BP 519A EP 519A PG 1 WC Cell Biology SC Cell Biology GA 377QY UT WOS:000165525902690 ER PT J AU Dolan, CE Bench, G Peariso, K Corzett, MH Penner-Hahn, JE Balhorn, R AF Dolan, CE Bench, G Peariso, K Corzett, MH Penner-Hahn, JE Balhorn, R TI Coordination of zinc by P2 changes during spermiogenesis in Syrian hamster SO MOLECULAR BIOLOGY OF THE CELL LA English DT Meeting Abstract C1 Univ Calif Lawrence Livermore Natl Lab, Biol & Biotechnol Res Program, Livermore, CA 94550 USA. Univ Michigan, Ann Arbor, MI 48109 USA. NR 0 TC 0 Z9 0 U1 1 U2 2 PU AMER SOC CELL BIOLOGY PI BETHESDA PA 8120 WOODMONT AVE, STE 750, BETHESDA, MD 20814-2755 USA SN 1059-1524 J9 MOL BIOL CELL JI Mol. Biol. Cell PD DEC PY 2000 VL 11 SU S MA 2684 BP 519A EP 519A PG 1 WC Cell Biology SC Cell Biology GA 377QY UT WOS:000165525902688 ER PT J AU Hirai, Y Boudreau, R Simian, M Stevens, M Oka, Y Takebe, K Niwa, S Bissell, MJ AF Hirai, Y Boudreau, R Simian, M Stevens, M Oka, Y Takebe, K Niwa, S Bissell, MJ TI Epimorphin alters the ratios of C/EBP-beta gene products with distinct consequences for mammary morphogenesis. SO MOLECULAR BIOLOGY OF THE CELL LA English DT Meeting Abstract C1 Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Div Life Sci, Berkeley, CA 94720 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER SOC CELL BIOLOGY PI BETHESDA PA 8120 WOODMONT AVE, STE 750, BETHESDA, MD 20814-2755 USA SN 1059-1524 J9 MOL BIOL CELL JI Mol. Biol. Cell PD DEC PY 2000 VL 11 SU S MA 2709 BP 523A EP 523A PG 1 WC Cell Biology SC Cell Biology GA 377QY UT WOS:000165525902713 ER PT J AU Krauss, SW Heald, RW Lee, GM Gimm, JA Nunomura, W Narla, M Chasis, JA AF Krauss, SW Heald, RW Lee, GM Gimm, JA Nunomura, W Narla, M Chasis, JA TI Dissecting protein 4.1 function in assembly of vertebrate nuclei, mitotic spindles and centrosomes. SO MOLECULAR BIOLOGY OF THE CELL LA English DT Meeting Abstract C1 Univ Calif Berkeley, LBNL, Berkeley, CA 94720 USA. Univ Calif Berkeley, MCB, Berkeley, CA USA. Tokyo Womens Med Univ, Tokyo, Japan. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER SOC CELL BIOLOGY PI BETHESDA PA 8120 WOODMONT AVE, STE 750, BETHESDA, MD 20814-2755 USA SN 1059-1524 J9 MOL BIOL CELL JI Mol. Biol. Cell PD DEC PY 2000 VL 11 SU S MA 2933 BP 567A EP 567A PG 1 WC Cell Biology SC Cell Biology GA 377QY UT WOS:000165525902937 ER PT J AU Gasch, AP Spellman, PT Kao, CM Carmel-Harel, O Eisen, MB Storz, G Botstein, D Brown, PO AF Gasch, AP Spellman, PT Kao, CM Carmel-Harel, O Eisen, MB Storz, G Botstein, D Brown, PO TI Genomic expression programs in the response of yeast cells to environmental changes SO MOLECULAR BIOLOGY OF THE CELL LA English DT Article ID OXIDATIVE STRESS RESPONSES; SHOCK TRANSCRIPTION FACTOR; UNFOLDED PROTEIN RESPONSE; SACCHAROMYCES-CEREVISIAE; GENE-EXPRESSION; HEAT-SHOCK; ENDOPLASMIC-RETICULUM; OSMOTIC-STRESS; KINASE; PATHWAY AB We explored genomic expression patterns in the yeast Saccharomyces cerevisiae responding to diverse environmental transitions. DNA microarrays were used to measure changes in transcript levels over time for almost every yeast gene, as cells responded to temperature shocks, hydrogen peroxide, the superoxide-generating drug menadione, the sulfhydryl-oxidizing agent diamide, the disulfide-reducing agent dithiothreitol, hyper- and hypo-osmotic shock, amino acid starvation, nitrogen source depletion, and progression into stationary phase. A large set of genes (similar to 900) showed a similar drastic response to almost all of these environmental changes. Additional features of the genomic responses were specialized for specific conditions. Promoter analysis and subsequent characterization of the responses of mutant strains implicated the transcription factors Yap1p, as well as Msn2p and Msn4p, in mediating specific features of the transcriptional response, while the identification of novel sequence elements provided clues to novel regulators. Physiological themes in the genomic responses to specific environmental stresses provided insights into the effects of those stresses on the cell. C1 Stanford Univ, Sch Med, Dept Biochem, Stanford, CA 94305 USA. Stanford Univ, Sch Med, Dept Genet, Stanford, CA 94305 USA. NICHHD, Cell Biol & Metab Branch, NIH, Bethesda, MD 20892 USA. Univ Calif Berkeley, Lawrence Berkeley Natl Labs, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Mol & Cellular Biol, Berkeley, CA 94720 USA. Stanford Univ, Howard Hughes Med Inst, Stanford, CA 94305 USA. RP Brown, PO (reprint author), Stanford Univ, Sch Med, Dept Biochem, Stanford, CA 94305 USA. OI Eisen, Michael/0000-0002-7528-738X; Storz, Gisela/0000-0001-6698-1241 FU NHGRI NIH HHS [HG-00450, HG-00983] NR 57 TC 2777 Z9 2843 U1 22 U2 201 PU AMER SOC CELL BIOLOGY PI BETHESDA PA 8120 WOODMONT AVE, STE 750, BETHESDA, MD 20814-2755 USA SN 1059-1524 J9 MOL BIOL CELL JI Mol. Biol. Cell PD DEC PY 2000 VL 11 IS 12 BP 4241 EP 4257 PG 17 WC Cell Biology SC Cell Biology GA 384PX UT WOS:000165955000015 PM 11102521 ER PT J AU DeWoody, JA Fletcher, DE Mackiewicz, M Wilkins, SD Avise, JC AF DeWoody, JA Fletcher, DE Mackiewicz, M Wilkins, SD Avise, JC TI The genetic mating system of spotted sunfish (Lepomis punctatus): mate numbers and the influence of male reproductive parasites SO MOLECULAR ECOLOGY LA English DT Article DE cuckoldry; evolutionarily stable strategy (ESS); maternity; mating tactics; microsatellite; paternity ID MALE BLUEGILL SUNFISH; CORAL-REEF FISH; CICHLID FISHES; LONGEAR SUNFISH; FEMALE CHOICE; TACTICS; POLYMORPHISM; COMPETITION; STRATEGIES; SATELLITES AB In nest-building fish species, mature males often exhibit one of two alternative reproductive behaviours. Bourgeois males build nests, court females, and guard their eggs. Parasitic cuckolders attempt to steal fertilizations from bourgeois males and do not invest in parental care. Previous evidence from the bluegill sunfish (Lepomis macrochirus) suggests that adult males are morphologically specialized for these two tactics. Here, we used microsatellite markers to determine genetic parentage in a natural population of the spotted sunfish (L. punctatus) that also displayed both bourgeois and parasitic male morphs. As gauged by relative investments in gonadal vs. somatic tissues, between 5 and 15% of the mature adult males were parasites. Multi-locus genotypes were generated for more than 1400 embryos in 30 nests, their nest-guardian males, and for other adults in the population. Progeny in approximately 57% of the nests were sired exclusively by the guardian male, but the remaining nests contained embryos resulting from cuckoldry as well. Overall, the frequency of offspring resulting from stolen fertilizations was only 1.3%, indicating that the great majority of paternity is by bourgeois nesting males. With regard to maternity, 87% of the nests had at least three dams, and computer simulations estimate that about 7.2 dams spawned per nest. C1 Univ Georgia, Dept Genet, Athens, GA 30602 USA. Savannah River Ecol Lab, Aiken, SC 29802 USA. RP DeWoody, JA (reprint author), Texas Tech Univ, Inst Environm & Human Hlth, Lubbock, TX 79409 USA. RI DeWoody, James/C-4909-2008 OI DeWoody, James/0000-0002-7315-5631 NR 43 TC 27 Z9 29 U1 2 U2 6 PU BLACKWELL SCIENCE LTD PI OXFORD PA P O BOX 88, OSNEY MEAD, OXFORD OX2 0NE, OXON, ENGLAND SN 0962-1083 J9 MOL ECOL JI Mol. Ecol. PD DEC PY 2000 VL 9 IS 12 BP 2119 EP 2128 DI 10.1046/j.1365-294X.2000.01123.x PG 10 WC Biochemistry & Molecular Biology; Ecology; Evolutionary Biology SC Biochemistry & Molecular Biology; Environmental Sciences & Ecology; Evolutionary Biology GA 387FR UT WOS:000166112700017 PM 11123623 ER PT J AU Li, W Detter, JC Weiss, HJ Cramer, EM Zhang, Q Novak, EK Favier, R Kingsmore, SF Swank, RT AF Li, W Detter, JC Weiss, HJ Cramer, EM Zhang, Q Novak, EK Favier, R Kingsmore, SF Swank, RT TI 5 '-UTR structural organization, transcript expression, and mutational analysis of the human Rab geranylgeranyl transferase alpha-subunit (RABGGTA) gene SO MOLECULAR GENETICS AND METABOLISM LA English DT Article DE Hermansky-Pudlak syndrome; platelet storage pool deficiency; gray platelet syndrome; Rab geranylgeranyl transferase alpha-subunit ID HERMANSKY-PUDLAK-SYNDROME; STORAGE POOL DEFICIENCY; VON-WILLEBRAND-FACTOR; PALE EAR EP; CDNA CLONING; BETA-SUBUNIT; MOUSE MODELS; TRANSGLUTAMINASE-1; PLATELETS; PROTEINS AB Hermansky-Pudlak syndrome (HPS) is a recessively inherited disease with dysfunction of several related subcellular organelles including platelet-dense granules, melanosomes, and lysosomes, Our recent identification of the mutation in murine Rab geranylgeranyl transferase alpha -subunit gene (Rabggta) in one mouse model of HPS, the gunmetal mouse, suggested that human patients with similar phenotypes might have mutations in the human orthologous RABGGTA gene. This prompted reanalysis of the 5'-untranslated structure of the human RABGGTA gene in normal individuals and in patients with deficiencies of platelet-dense granules (alpha delta -SPD), alpha granules (alpha -SPD or gray platelet syndrome, GPS) or alpha plus dense granules (alpha delta -SPD), We report the complete sequence of intron alpha of RABGGTA and demonstrate that exon alpha is immediately upstream of intron alpha. The exon/intron structural organization of the 5'-untranslated region (UTR) of human RABGGTA was found to be similar to that of the mouse Rabggta gene. However, exons alpha and introns alpha are not homologous between mouse and human. Features of the 5'-UTR of RABGGTA suggest it is a housekeeping gene. While obvious disease-causing mutations of human RABGGTA were not found in our existing SPD patients by sequencing its entire coding region, several polymorphisms of RABGGTA including a putative cryptic splicing mutation in intron 4 were identified. Knowledge of the 5'-UTR structure of RABGGTA and its common polymorphisms will be useful for mutation screening or linkage analysis in patients with albinism, thrombocytopenia, or platelet SPD. (C) 2000 Academic Press. C1 Roswell Pk Canc Inst, Dept Mol & Cellular Biol, Buffalo, NY 14268 USA. DOE Joint Genome Inst, Walnut Creek, CA 94598 USA. St Lukes Roosevelt Hosp Ctr, Div Hematol Oncol, New York, NY 10019 USA. Hop Cochin, Dept Hematol ICGM, F-75014 Paris, France. Mol Staging Inc, Guilford, CT 06437 USA. Hop Enfants Armand Trousseau, Serv Hematol Biol, Paris, France. RP Swank, RT (reprint author), Roswell Pk Canc Inst, Dept Mol & Cellular Biol, Elm & Carlton St, Buffalo, NY 14268 USA. OI kingsmore, stephen/0000-0002-3758-4631 FU NEI NIH HHS [EY12104]; NHLBI NIH HHS [HL31698, HL51480] NR 38 TC 4 Z9 4 U1 0 U2 0 PU ACADEMIC PRESS INC PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 1096-7192 J9 MOL GENET METAB JI Mol. Genet. Metab. PD DEC PY 2000 VL 71 IS 4 BP 599 EP 608 DI 10.1006/mgme.2000.3091 PG 10 WC Endocrinology & Metabolism; Genetics & Heredity; Medicine, Research & Experimental SC Endocrinology & Metabolism; Genetics & Heredity; Research & Experimental Medicine GA 388FW UT WOS:000166167600009 PM 11136552 ER PT J AU Sullivan, M Ellis, R Nugent, P Smail, I Madau, P AF Sullivan, M Ellis, R Nugent, P Smail, I Madau, P TI A strategy for finding gravitationally lensed distant supernovae SO MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY LA English DT Article DE supernovae : general; galaxies : clusters : general; cosmology : observations; gravitational lensing ID ULTRAVIOLET LUMINOSITY DENSITY; SPACE-TELESCOPE OBSERVATIONS; HIGH-REDSHIFT SUPERNOVAE; STAR-FORMATION HISTORY; HUBBLE DEEP FIELD; IA SUPERNOVAE; COSMOLOGICAL MODELS; GALAXIES; EVOLUTION; UNIVERSE AB Distant Type Ia and II supernovae (SNe) can serve as valuable probes of the history of the cosmic expansion and star formation, and provide important information on their progenitor models. At present, however, there are few observational constraints on the abundance of SNe at high redshifts, A major science driver for the Next Generation Space Telescope is the study of such very distant SNe. In this paper we discuss strategies for finding and counting distant SNe by using repeat imaging of supercritical intermediate redshift clusters whose mass distributions are well constrained via modelling of strongly lensed features. For a variety of different models for the star formation history and supernova progenitors, we estimate the likelihood of detecting lensed SNe as a function of their redshift. In the case of a survey conducted with Hubble Space Telescope (HST), we predict a high probability of seeing a supernova in a single return visit with either Wide Field Planetary Camera 2 or Advanced Camera for Surveys, and a much higher probability of detecting examples with z > 1 in the lensed case. Most events would represent magnified SNe II at z similar or equal to 1, and a fraction will be more distant examples. We discuss various ways to classify such events using ground-based infrared photometry. We demonstrate an application of the method using the HST archival data and discuss the case of a possible event found in the rich cluster AC 114 (z = 0.31). C1 Univ Cambridge, Inst Astron, Cambridge CB3 OHA, England. CALTECH, Pasadena, CA 91125 USA. EO Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. Univ Durham, Dept Phys, Durham DH1 3LE, England. RP Sullivan, M (reprint author), Univ Cambridge, Inst Astron, Madingley Rd, Cambridge CB3 OHA, England. EM ms@ast.cam.ac.uk RI Smail, Ian/M-5161-2013 OI Smail, Ian/0000-0003-3037-257X NR 51 TC 34 Z9 34 U1 0 U2 0 PU WILEY-BLACKWELL PI MALDEN PA COMMERCE PLACE, 350 MAIN ST, MALDEN 02148, MA USA SN 0035-8711 J9 MON NOT R ASTRON SOC JI Mon. Not. Roy. Astron. Soc. PD DEC 1 PY 2000 VL 319 IS 2 BP 549 EP 556 DI 10.1046/j.1365-8711.2000.03875.x PG 8 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 387FN UT WOS:000166112300022 ER PT J AU Auciello, O AF Auciello, O TI Alan Krauss SO MRS BULLETIN LA English DT Biographical-Item C1 Argonne Natl Lab, Argonne, IL 60439 USA. RP Auciello, O (reprint author), Argonne Natl Lab, Argonne, IL 60439 USA. NR 1 TC 0 Z9 0 U1 0 U2 0 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DR, WARRENDALE, PA 15086 USA SN 0883-7694 J9 MRS BULL JI MRS Bull. PD DEC PY 2000 VL 25 IS 12 BP 6 EP 6 PG 1 WC Materials Science, Multidisciplinary; Physics, Applied SC Materials Science; Physics GA 383XN UT WOS:000165910100008 ER PT J AU Grabowski, TJ Frank, RJ Szumski, NR Brown, CK Damasio, H AF Grabowski, TJ Frank, RJ Szumski, NR Brown, CK Damasio, H TI Validation of partial tissue segmentation of single-channel magnetic resonance images of the brain SO NEUROIMAGE LA English DT Article ID CEREBROSPINAL-FLUID SPACES; GRAY-MATTER VOLUMES; MR-IMAGES; WHITE-MATTER; MULTISPECTRAL ANALYSIS; CSF; CLASSIFICATION; QUANTIFICATION; ALGORITHM; SURFACE AB We describe and evaluate a practical, automated algorithm based on local statistical mixture modeling for segmenting single-channel, T1-weighted volumetric magnetic resonance images of the brain into gray matter, white matter, and cerebrospinal fluid. We employed a stereological sampling method to assess, prospectively, the performance of the method with respect to human experts on 10 normal T1-weighted brain scans acquired with a three-dimensional gradient echo pulse sequence. The overall kappa statistic for the concordance of the algorithm with the human experts was 0.806, while that among raters, excluding the algorithm, was 0.802. The algorithm had better agreement with the modal expert decision (kappa = 0.878). The algorithm could not be distinguished from the experts by this measure. We also validated the algorithm oil a simulated MR scan of a digital brain phantom with known tissue composition. Global gray matter and white matter errors were 1% and <1%, respectively, and correlation coefficients with the underlying tissue model were 0.95 for gray matter, 0.98 for white matter, and 0.95 for cerebrospinal fluid. In both approaches to validation, we evaluated both local and global performance of the algorithm. Human experts generated slightly higher global gray matter proportion estimates on the test brain scans relative to the algorithm (3.7%) and on the simulated MR scan relative to the true tissue model (4.4%). The algorithm underestimated gray in some subcortical nuclei which contain admired gray and white matter. We demonstrate the reliability of the method on individual 1 NEX data sets of the test subjects, and its insensitivity to the precise values of initial model parameters. The output of this algorithm is suitable for quantifying cerebral cortical tissue, using a commonly performed commercial pulse sequence. (C) 2000 Academic Press. C1 Univ Iowa, Coll Med, Dept Neurol, Div Behav Neurol & Cognit Neurosci, Iowa City, IA 52242 USA. Univ Calif Lawrence Livermore Natl Lab, Livermore, CA USA. Univ Iowa, Coll Publ Hlth, Dept Biostat, Iowa City, IA 52242 USA. RP Grabowski, TJ (reprint author), Univ Iowa, Coll Med, Dept Neurol, Div Behav Neurol & Cognit Neurosci, 200 Hawkins Dr, Iowa City, IA 52242 USA. FU NINDS NIH HHS [P01 NS 19632] NR 59 TC 53 Z9 53 U1 0 U2 0 PU ACADEMIC PRESS INC PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 1053-8119 J9 NEUROIMAGE JI Neuroimage PD DEC PY 2000 VL 12 IS 6 BP 640 EP 656 DI 10.1006/nimg.2000.0649 PG 17 WC Neurosciences; Neuroimaging; Radiology, Nuclear Medicine & Medical Imaging SC Neurosciences & Neurology; Radiology, Nuclear Medicine & Medical Imaging GA 378BT UT WOS:000165562300004 PM 11112396 ER PT J AU Frutos, R Gido, D Henneges, G Schmuck, P AF Frutos, R Gido, D Henneges, G Schmuck, P TI Calculation of fission product behaviour in an advanced containment in case of a severe accident SO NUCLEAR ENGINEERING AND DESIGN LA English DT Article AB The aim of the present work is to demonstrate the applicability of the MELCOR- and CONTAIN-computer programs, respectively, to determine the radiological source terms (RST) of a pressurized water reactor under conservative release conditions based on preliminary reactor data from the European Pressurized Water Reactor Conceptional Design Phase. The determination of the RST means the quantification of the possible release of radionuclides from the plant (mostly from the containment) into the environment in case of a severe accident. This contribution gives an outline of the procedures by which the RST can be estimated conservatively. Such procedures have to be known if the 'harmful effects of ionizing radiation' outside the reactor plant, as mentioned in legislation, are determined in a proper way. It is demonstrated that the computer codes available at Forschungszentrum Karlsruhe can be used for the complete analyses of the containment behaviour and the accident consequences, provided that the design data of the nuclear reactor and information on the initiating phase of the accident are available. The first 12 h of a postulated Large Break Loss-of-Coolant Accident are analysed and a time dependent RST to the environment is calculated, which can be used as input for the COSYMA code system for the assessment of the accident consequences. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Forschungszentrum Karlsruhe, IKET, D-76021 Karlsruhe, Germany. Univ Madrid, Madrid 3, Spain. Sandia Natl Lab, Albuquerque, NM USA. RP Henneges, G (reprint author), Forschungszentrum Karlsruhe, IKET, Postfach 3640, D-76021 Karlsruhe, Germany. NR 5 TC 2 Z9 3 U1 0 U2 1 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0029-5493 J9 NUCL ENG DES JI Nucl. Eng. Des. PD DEC PY 2000 VL 202 IS 2-3 BP 173 EP 178 DI 10.1016/S0029-5493(00)00356-3 PG 6 WC Nuclear Science & Technology SC Nuclear Science & Technology GA 381ZE UT WOS:000165793300007 ER PT J AU Boucher, D Connor, JW Houlberg, WA Turner, MF Bracco, G Chudnovskiy, A Cordey, JG Greenwald, MJ Hoang, GT Hogeweij, GMD Kaye, SM Kinsey, JE Mikkelsen, DR Ongena, J Schissel, DR Shirai, H Stober, J Subberfield, PM Waltz, RE Weiland, J AF Boucher, D Connor, JW Houlberg, WA Turner, MF Bracco, G Chudnovskiy, A Cordey, JG Greenwald, MJ Hoang, GT Hogeweij, GMD Kaye, SM Kinsey, JE Mikkelsen, DR Ongena, J Schissel, DR Shirai, H Stober, J Subberfield, PM Waltz, RE Weiland, J CA ITER 1D Modelling Working Grp TI The International Multi-Tokamak Profile Database SO NUCLEAR FUSION LA English DT Article ID ALCATOR-C-MOD; FUSION TEST REACTOR; IMPROVED CONFINEMENT REGIMES; DEUTERIUM-TRITIUM PLASMAS; REVERSED-MAGNETIC SHEAR; ELECTRON HEAT-TRANSPORT; W-SHAPED DIVERTOR; H-MODE; ENERGY CONFINEMENT; DIII-D AB An international multi-tokamak profile database has been assembled, constituting a representative set of reference tokamak discharges for the purpose of testing local transport models against well documented data. In particular, it will allow one to measure the accuracy with which the models can reproduce experiments and draw confidence intervals for the predictions of the models outside the range covered in the database. This database is now available to the fusion community and may be accessed by anonymous ftp to iterphys.naka.go.jp; the purpose of this article is to describe the structure of the database and the discharges contributing to it so that all can take full advantage of this resource. Thus, after an introductory general discussion of the database, there is a more detailed description of its structure, with listings of variables emphasized and how to access the database. There is then a brief description of each contributing tokamak and information on the type of discharges available from that tokamak. This is followed by a more quantitative description of the data, giving the ranges of dimensional and dimensionless variables available. Some typical modelling results to illustrate the use of the database are given in the conclusion. C1 ITER, Naka Joint Work Site, Naka Ku, Ibaraki, Osaka, Japan. UKAEA Euratom Fus Assoc, Culham Sci Ctr, Abingdon, Oxon, England. Oak Ridge Natl Lab, Oak Ridge, TN USA. ENEA Fus, EURATOM Assoc, CRE Frascati, Rome, Italy. Russian Res Ctr, Kurchatov Inst, Moscow, Russia. MIT, Cambridge, MA 02139 USA. EURATOM, CEA, Ctr Etud Cadarache, St Paul Les Durance, France. EURATOM, FOM, Inst Plasma Phys, Nieuwegein, Netherlands. Princeton Univ, Princeton Plasma Phys Lab, Princeton, NJ 08543 USA. Lehigh Univ, Bethlehem, PA 18015 USA. Assoc Euratom Belgian State, Koninglijke Mil Sch, Ecole Royale Mil, Brussels, Belgium. Gen Atom Co, San Diego, CA USA. Japan Atom Energy Res Inst, Naka Ku, Ibaraki, Osaka, Japan. Max Planck Inst Plasma Phys, EURATOM Assoc, D-85748 Garching, Germany. Chalmers, S-41296 Gothenburg, Sweden. RP Boucher, D (reprint author), ITER, Naka Joint Work Site, Naka Ku, Ibaraki, Osaka, Japan. EM jack.connor@ukaea.org.uk NR 88 TC 42 Z9 42 U1 0 U2 2 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 DEC PY 2000 VL 40 IS 12 BP 1955 EP 1981 PG 27 WC Physics, Fluids & Plasmas SC Physics GA 384QN UT WOS:000165956500002 ER PT J AU Pollaine, SM AF Pollaine, SM TI Radiation transport between two concentric spheres SO NUCLEAR FUSION LA English DT Article ID SPHERICAL CAPSULE; SYMMETRIZATION; ILLUMINATION; TARGETS; CAVITY AB The eigenfunctions for the transport of radiation between concentric spheres are proved to be the spherical harmonics and Legendre polynomials. The corresponding eigenvalues are then derived for the cases of both an outer emitting sphere and an inner absorbing sphere, and an inner emitting sphere and an outer absorbing sphere. Simple approximations to these eigenvalues are found and their various properties are derived. These results are then applied to the problem of ICF capsules inside hohlraums. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Pollaine, SM (reprint author), Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. NR 12 TC 6 Z9 6 U1 0 U2 4 PU INT ATOMIC ENERGY AGENCY PI VIENNA PA WAGRAMERSTRASSE 5, PO BOX 100, A-1400 VIENNA, AUSTRIA SN 0029-5515 J9 NUCL FUSION JI Nucl. Fusion PD DEC PY 2000 VL 40 IS 12 BP 2061 EP 2069 DI 10.1088/0029-5515/40/12/309 PG 9 WC Physics, Fluids & Plasmas SC Physics GA 384QN UT WOS:000165956500009 ER PT J AU Byrd, JM De Santis, S Georgsson, M Stover, G Fox, JD Teytelman, D AF Byrd, JM De Santis, S Georgsson, M Stover, G Fox, JD Teytelman, D TI Commissioning of a higher harmonic RF system for the Advanced Light Source SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article DE storage rings; radio frequency cavities; Touschek lifetime; coupled bunch instabilities AB We report on the commissioning of a higher harmonic RF system designed to improve the Touschek lifetime of the Advanced Light Source. In our best results, we have achieved over a factor of two increase in the beam lifetime. Transient beam loading of the harmonic cavities by unequal fill patterns presents the greatest limitations on lifetime improvement. We also describe several interesting effects of the harmonic cavities on the operation of the longitudinal and transverse multibunch feedback systems. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Adv Light Source Div, Berkeley, CA 94720 USA. Univ Calif Davis, Dept Phys, Davis, CA 95616 USA. Stanford Linear Accelerator Ctr, Menlo Park, CA 94025 USA. RP Byrd, JM (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Adv Light Source Div, Mail Stop 80-101,1 Cyclotron Rd, Berkeley, CA 94720 USA. NR 16 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 DEC 1 PY 2000 VL 455 IS 2 BP 271 EP 282 DI 10.1016/S0168-9002(00)00504-0 PG 12 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 383AH UT WOS:000165859200002 ER PT J AU Chen, YC Cheng, KC Choong, WS Dukes, EC Gu, P Ho, C James, C Kaplan, DM Luebke, WR Luk, KB Nelson, K Rubin, HA Sheng, JP White, CG Yu, CS AF Chen, YC Cheng, KC Choong, WS Dukes, EC Gu, P Ho, C James, C Kaplan, DM Luebke, WR Luk, KB Nelson, K Rubin, HA Sheng, JP White, CG Yu, CS TI A high-throughput data acquisition system for the HyperCP experiment SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article DE acquisition; HyperCP; E871; Fermilab; hyperon; CP violation ID COLLISIONS AB The data acquisition system of the HyperCP experiment at Fermilab recorded about 50 TB of data on 12 000 tapes in 1997. The system recorded data at a sustained throughput of 12 MB/s typically and was capable of a maximum rate of 16 MB/s. The front-end electronics systems read 20 000 channels and achieved a typical readout dead time of about 3 mus per event, allowing operation at a trigger rate of 75 kHz with less than 30% dead time. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Fermilab, Batavia, IL 60510 USA. Acad Sinica, Inst Phys, Taipei 115, Taiwan. IIT, Dept Biol Chem & Phys Sci, Div Phys, Chicago, IL 60616 USA. Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. Lawrence Berkeley Natl Lab, Div Phys, Berkeley, CA 94720 USA. Univ Virginia, Dept Phys, Charlottesville, VA 22901 USA. RP Chen, YC (reprint author), Fermilab, MS 122 E 871, Batavia, IL 60510 USA. NR 14 TC 7 Z9 8 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD DEC 1 PY 2000 VL 455 IS 2 BP 424 EP 432 DI 10.1016/S0168-9002(00)00509-X PG 9 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 383AH UT WOS:000165859200017 ER PT J AU Stoyer, NJ Stoyer, MA Wild, JF Moody, KJ Lougheed, RW Oganessian, YT Utyonkov, VK AF Stoyer, NJ Stoyer, MA Wild, JF Moody, KJ Lougheed, RW Oganessian, YT Utyonkov, VK TI Random probability analysis of heavy-element data SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article ID SUPERHEAVY NUCLEI AB In this paper, we present the Monte Carlo Random Probability (MCRP) calculational method details that were developed for the determination of random correlations in a set of unrelated data. After finding random correlations, we further process the correlations by applying nuclear property systematics. We compare the results of MCRP with methods presented in other references. The MCRP method can provide a conservative estimate of the random probability associated with observed events that takes into account the entire background observed in the experiment and ally other running conditions (noise, decay of long-lived species, etc.) which may have been sporadic or intermittent. We discuss a particular example of a set of correlated alpha decays and its interpretation as a candidate decay chain. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. Joint Inst Nucl Res, Dubna 141980, Russia. RP Stoyer, NJ (reprint author), Univ Calif Lawrence Livermore Natl Lab, L-231,POB 808, Livermore, CA 94551 USA. NR 5 TC 11 Z9 11 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD DEC 1 PY 2000 VL 455 IS 2 BP 433 EP 441 DI 10.1016/S0168-9002(00)00503-9 PG 9 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 383AH UT WOS:000165859200018 ER PT J AU Powell, J Joosten, R Donahue, CA Fairchild, RF Fujisawa, J Guo, FQ Haustein, PE Larimer, RM Lyneis, CM McMahan, MA Moltz, DM Norman, EB O'Neil, JP Ostas, MA Rowe, MW VanBrocklin, HF Wutte, D Xie, ZQ Xu, XJ Cerny, J AF Powell, J Joosten, R Donahue, CA Fairchild, RF Fujisawa, J Guo, FQ Haustein, PE Larimer, RM Lyneis, CM McMahan, MA Moltz, DM Norman, EB O'Neil, JP Ostas, MA Rowe, MW VanBrocklin, HF Wutte, D Xie, ZQ Xu, XJ Cerny, J TI BEARS: radioactive ion beams at Berkeley SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article DE radioactive beams; carbon-11 beam; BEARS ID F-18 AB A light-isotope radioactive ion-beam capability has been added to the 88-in. Cyclotron at Lawrence Berkeley National Laboratory by coupling to the production cyclotron of the Berkeley Isotope Facility. The connection required the development and construction of a 350 m gas transport system between the two accelerators as well as automated cryogenic separation of the produced activity. The first beam developed. (11)C, has been successfully accelerated with an on-target intensity of 1 x 10(8) ions/s at energies of around 10 MeV/u. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. Brookhaven Natl Lab, Upton, NY 11973 USA. RP Powell, J (reprint author), Lawrence Berkeley Natl Lab, 1 Cyclotron Rd, Berkeley, CA 94720 USA. EM jdpowell@lbl.gov NR 7 TC 19 Z9 19 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 DEC 1 PY 2000 VL 455 IS 2 BP 452 EP 459 DI 10.1016/S0168-9002(00)00508-8 PG 8 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 383AH UT WOS:000165859200020 ER PT J AU Brodsky, SJ AF Brodsky, SJ TI The light-cone Fock representation in QCD SO NUCLEAR PHYSICS B-PROCEEDINGS SUPPLEMENTS LA English DT Article; Proceedings Paper CT Xth International Light-Cone-Meeting CY JUN 13-17, 2000 CL HEIDELBERG, GERMANY ID VIRTUAL COMPTON-SCATTERING; LARGE MOMENTUM-TRANSFER; FORM-FACTORS; QUANTUM CHROMODYNAMICS; PARTON DISTRIBUTIONS; EVOLUTION-EQUATIONS; EXCLUSIVE PROCESSES; FIELD-THEORY; COLOR TRANSPARENCY; INTRINSIC CHARM AB The light-cone Fock-state representation of QCD encodes the properties of a hadrons in terms of frame-independent wavefunctions, providing a systematic framework for evaluating structure functions, exclusive hadronic matrix elements, including time-like heavy hadron decay amplitudes, form factors, and deeply virtual Compton scattering. A new type of jet production reaction,''self-resolving diffractive interactions" can provide direct information on the light-cone wavefunctions of hadrons in terms of their quark and gluon degrees of freedom as well as the composition of nuclei in terms of their nucleon and mesonic degrees of freedom. The relation of the intrinsic sea to the light-cone wavefunctions is discussed. Tho decomposition of light-cone spin is illustrated for the quantum fluctuations of an electron. C1 Stanford Univ, Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. RP Brodsky, SJ (reprint author), Stanford Univ, Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. NR 78 TC 9 Z9 9 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 DEC PY 2000 VL 90 BP 3 EP 13 DI 10.1016/S0920-5632(00)00863-X PG 11 WC Physics, Particles & Fields SC Physics GA 388YV UT WOS:000166211400003 ER PT J AU Radyushkin, AV AF Radyushkin, AV TI Generalized parton distributions SO NUCLEAR PHYSICS B-PROCEEDINGS SUPPLEMENTS LA English DT Article; Proceedings Paper CT Xth International Light-Cone-Meeting CY JUN 13-17, 2000 CL HEIDELBERG, GERMANY ID HARD EXCLUSIVE ELECTROPRODUCTION; VIRTUAL COMPTON-SCATTERING; MESONS C1 Old Dominion Univ, Dept Phys, Norfolk, VA 23529 USA. Jefferson Lab, Newport News, VA 23606 USA. RP Radyushkin, AV (reprint author), Old Dominion Univ, Dept Phys, Norfolk, VA 23529 USA. NR 12 TC 4 Z9 4 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 DEC PY 2000 VL 90 BP 113 EP 116 DI 10.1016/S0920-5632(00)00882-3 PG 4 WC Physics, Particles & Fields SC Physics GA 388YV UT WOS:000166211400024 ER PT J AU Brisudova, MM Burakovsky, L Goldman, T AF Brisudova, MM Burakovsky, L Goldman, T TI Lessons from hadron phenomenology SO NUCLEAR PHYSICS B-PROCEEDINGS SUPPLEMENTS LA English DT Article; Proceedings Paper CT Xth International Light-Cone-Meeting CY JUN 13-17, 2000 CL HEIDELBERG, GERMANY AB Meson spectra can be well approximated by a specific form of a nonlinear Regge trajectory which is consistent with a finite number of bound states. This may have important consequences for experiment, and may be a hint for the theory. C1 Univ Florida, Dept Phys, Gainesville, FL 32611 USA. Univ Calif Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87544 USA. RP Brisudova, MM (reprint author), Univ Florida, Dept Phys, Gainesville, FL 32611 USA. NR 8 TC 0 Z9 0 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0920-5632 J9 NUCL PHYS B-PROC SUP JI Nucl. Phys. B-Proc. Suppl. PD DEC PY 2000 VL 90 BP 120 EP 122 DI 10.1016/S0920-5632(00)00884-7 PG 3 WC Physics, Particles & Fields SC Physics GA 388YV UT WOS:000166211400026 ER PT J AU Blackwood, LG Harker, YD AF Blackwood, LG Harker, YD TI The effect of measurement bias on nuclear criticality safety calculations for Wipp TRUPACT-II shipments SO NUCLEAR TECHNOLOGY LA English DT Article AB Current nuclear criticality safety limit requirements for transporting TRUPACT-II waste containers to the U,S, Department of Energy's Waste Isolation Pilot Plant (WIPP) specify that the Pu-239 fissile gram equivalent (FGE) plus two times its measurement error must be less than or equal to 325 g for a payload of fourteen 55-gal drums. The authorized method for calculating a TR UPACT-II FGE measurement error value is to take the square root of the sum of the squared error values for the individual containers (often called root-sum-squares or simply RSS). However, to the extent that the individual drum measurements contain common bias effects (e,g., due to common calibration or other adjustment factors), the corresponding measurement errors are correlated, and simple RSS calculations will underestimate the true error in the TRUPACT-II FGE value. The RSS calculations assume independence, while common bins effects can induce strong correlations between the errors ill measurements, Significant bias effects can occur when the matrix characteristics for a particular waste type are not fully accounted for in the measurement process. Depending on the relative size of the bins error compared to precision error, the true measurement error can be greater than twice that calculated by RSS. In such cases, the FGE shipping requirement may not be met. To avoid underestimating the error, bins components should be estimated and propagated separately (combined only at the final step in the TR UPACT-II FGE calculation), or the effect of bias on covariance between measurements must be calculated These covariance terms then need to be included in the final uncertainty calculations. C1 Idaho Natl Engn & Environm Lab, Idaho Falls, ID 83415 USA. RP Blackwood, LG (reprint author), Idaho Natl Engn & Environm Lab, POB 1625, Idaho Falls, ID 83415 USA. NR 3 TC 0 Z9 0 U1 0 U2 0 PU AMER NUCLEAR SOCIETY PI LA GRANGE PK PA 555 N KENSINGTON AVENUE, LA GRANGE PK, IL 60525 USA SN 0029-5450 J9 NUCL TECHNOL JI Nucl. Technol. PD DEC PY 2000 VL 132 IS 3 BP 366 EP 374 PG 9 WC Nuclear Science & Technology SC Nuclear Science & Technology GA 375TV UT WOS:000165418100004 ER PT J AU Gregory, MV Paul, PK AF Gregory, MV Paul, PK TI Efficient simulation modeling of an integrated high-level-waste processing complex SO NUCLEAR TECHNOLOGY LA English DT Article AB An integrated computational tool named the Production Planning Model (ProdMod) has been developed to simulate the operation of the entire high-level-waste complex (HLW) at the Savannah River Site (SRS) over its full life cycle. ProdMod is used to guide SRS management in operating the waste complex in an economically efficient and environmentally sound manner. SRS HLW operations are modeled using coupled algebraic equations. The dynamic nature of plant processes is modeled in the form of a linear construct in which the time dependence is implicit. Batch processes are modeled in discrete event-space, while continuous processes are modeled in time-space. The ProdMod methodology maps between event-space and time-space such that the inherent mathematical discontinuities in batch process simulation are avoided without sacrificing any of the necessary detail in the batch recipe steps. Modeling the processes separately in event-space and time-space using linear constructs, and then coupling the two spaces, has accelerated the speed of simulation compared to a typical dynamic simulation. The ProdMod simulator models have been validated against operating data and other computer codes. Case studies have demonstrated the usefulness of the ProdMod simulator in developing strategies that demonstrate significant cost savings in operating the SRS HLW complex and in verifying the feasibility of newly proposed processes. C1 Westinghouse Savannah River Co, Savannah River Technol Ctr, Aiken, SC 29808 USA. RP Gregory, MV (reprint author), Westinghouse Savannah River Co, Savannah River Technol Ctr, Bldg 773-42A, Aiken, SC 29808 USA. NR 13 TC 1 Z9 1 U1 0 U2 0 PU AMER NUCLEAR SOCIETY PI LA GRANGE PK PA 555 N KENSINGTON AVENUE, LA GRANGE PK, IL 60525 USA SN 0029-5450 J9 NUCL TECHNOL JI Nucl. Technol. PD DEC PY 2000 VL 132 IS 3 BP 424 EP 435 PG 12 WC Nuclear Science & Technology SC Nuclear Science & Technology GA 375TV UT WOS:000165418100009 ER PT J AU Romanek, CS Gaines, KF Bryan, AL Brisbin, IL AF Romanek, CS Gaines, KF Bryan, AL Brisbin, IL TI Foraging ecology of the endangered wood stork recorded in the stable isotope signature of feathers SO OECOLOGIA LA English DT Article DE wood stork; feather; stable isotopes; geographic information system; conservation ID EAST-CENTRAL GEORGIA; CARBON ISOTOPES; TROPHIC RELATIONSHIPS; DELTA-C-13 ANALYSIS; NEAREST-NEIGHBORS; UNITED-STATES; SALT-MARSH; DIETS; FOOD; RATIOS AB Down feathers and regurgitant were collected from nestling wood storks (Mycteria americana) from two inland and two coastal breeding colonies in Georgia. The stable isotopic ratios of carbon (C-13/C-12) and nitrogen (N-15/N-14) in these materials were analyzed to gain insights into the natal origins of juvenile storks and the foraging activities of adults. Down feathers differed in delta C-13 between inland and coastal colonies, having average isotopic values that reflected the sources of carbon fixed in biomass at the base of the food web. Feathers from the inland colonies differed between colonies in delta N-15, while those from the coastal colonies did not. These patterns primarily reflected the foraging activities of parent storks, with individuals capturing differing percentages of prey of distinct trophic status at each colony. Collectively, the carbon and nitrogen isotopic signatures of feather keratin were used to distinguish nestlings from each colony, except for instances where storks from different colonies foraged in common wetlands. The stable isotopic composition of food items in regurgitant was used to reconstruct the trophic structure of the ecosystems in which wood storks foraged. Predicted foraging activities based on the isotopic composition of keratin were generally consistent with the percentage of prey types (freshwater vs, saltwater and lower trophic level vs. upper trophic level consumer) observed in regurgitant, except for the coastal colony at St. Simons Island, where the delta C-13 of feathers strongly suggested that freshwater prey were a significant component of the diet. This inconsistency was resolved by aerial tracking of adults during foraging excursions using a fixed-wing aircraft. Observed foraging activities supported interpretations based on the stable isotope content of feathers, suggesting that the latter provided a better record of overall foraging activity than regurgitant analysis alone. Observed foraging patterns were compared to the predictions of a statistical model that determined habitat utilization based on habitat availability using a geographic information system (GIS) database. Observed foraging activities and those predicted from feathers both suggested that some adult storks preferred to feed their young freshwater prey, even when saltwater resources were more accessible in the local environment, This conclusion supports the contention that wood stork populations are sensitive to changes in the distribution of freshwater habitats along the southeastern coastal plain of the United States. C1 Savannah River Ecol Lab, Drawer E, Aiken, SC 29802 USA. Univ Georgia, Dept Geol, Athens, GA 30602 USA. RP Romanek, CS (reprint author), Savannah River Ecol Lab, Drawer E, Aiken, SC 29802 USA. NR 66 TC 18 Z9 19 U1 5 U2 15 PU SPRINGER-VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 USA SN 0029-8549 J9 OECOLOGIA JI Oecologia PD DEC PY 2000 VL 125 IS 4 BP 584 EP 594 DI 10.1007/s004420000471 PG 11 WC Ecology SC Environmental Sciences & Ecology GA 376DK UT WOS:000165442800015 ER PT J AU Berryman, JG AF Berryman, James G. TI Analysis of Approximate Inverses in Tomography II. Iterative Inverses SO OPTIMIZATION AND ENGINEERING LA English DT Article DE acoustic tomography; numerical methods; resolution matrices; singular value; conjugate gradients decomposition ID LEAST-SQUARES; RESOLUTION; ALGORITHM; RECONSTRUCTION; PROJECTIONS; MATRIX; LSQR AB This paper continues the analysis of approximate inverses from Part I by concentrating on iterative inverses in linear tomographic applications. The importance of differentiating between the ideal resolution of the operator/matrix to be inverted and the actual or effective resolution obtained by the approximate inverse during an iterative procedure is stressed. Means of obtaining the effective resolution operator for standard iterative procedures such as conjugate gradients, Lanczos, and LSQR are provided, while circumventing the usual need to produce a singular-value decomposition of the operator being inverted. The methods discussed produce very simple results in calculations with infinite precision, but require reorthogonalization of the Krylov vectors/operators produced by the iterative procedures in finite precision. Although this need for reorthogonalization increases the expense of the procedure somewhat, it still produces the desired results much more efficiently than what could be obtained using a full singular-value decomposition of the operator. C1 Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. RP Berryman, JG (reprint author), Lawrence Livermore Natl Lab, POB 808 L-200, Livermore, CA 94551 USA. FU U. S. Department of Energy; University of California Lawrence Livermore National Laboratory [W-7405-ENG-48]; Environmental Management Science Program; Office of Science and Technology, Office of Environmental Management; Stanford Exploration Project FX I thank S. F. Ashby, R. Burridge, J. F. Claerbout, S. Fomel, G. R. Goldstein, J. A. Goldstein, D. M. Goodman, J. B. Keller, F. Muir, G. Nolet, G. Papanicolaou, B. N. Parlett, S. Ronen, W. W. Symes, H. A. van der Vorst, and J. J. Zucca for helpful discussions, lectures, collaborations, correspondence and/or criticism. I especially thank M. A. Saunders for constructive criticism and suggestions for improving the presentation of the results concerning the LSQR method. This work was performed under the auspices of the U. S. Department of Energy by the University of California Lawrence Livermore National Laboratory under contract No. W-7405-ENG-48 and supported by the Environmental Management Science Program with oversight by the Engineering Research Division of the Office of Basic Energy Sciences, Office of Energy Research, and by the Office of Science and Technology, Office of Environmental Management. Early work in this area was performed while the author was visiting the Geophysics Department at Stanford University. Partial support for this visit was provided by the Stanford Exploration Project, whose sponsors are hereby gratefully acknowledged. NR 31 TC 21 Z9 21 U1 0 U2 1 PU SPRINGER PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 1389-4420 J9 OPTIM ENG JI Optim. Eng. PD DEC PY 2000 VL 1 IS 4 BP 437 EP 473 DI 10.1023/A:1011588308111 PG 37 WC Engineering, Multidisciplinary; Operations Research & Management Science; Mathematics, Interdisciplinary Applications SC Engineering; Operations Research & Management Science; Mathematics GA V19TR UT WOS:000208095200004 ER PT J AU Leyens, C Wright, IG Pint, BA AF Leyens, C Wright, IG Pint, BA TI Hot corrosion of an EB-PVD thermal-barrier coating system at 950 degrees C SO OXIDATION OF METALS LA English DT Article DE hot-corrosion testing; MCrAlY-type bond-coat alloys; EB-PVD thermal barrier coatings; oxide-scale fluxing; biomass-derived fuel combustion atmosphere AB Model thermal-barrier coating (TBC) systems consisting of cast NiCrAlY substrates and electron-beam, physically vapor-deposited (EB-PVD) partially yttria-stabilized zirconia (PYSZ) coatings with three different microstructures were tested in I-hr cycles at 9500 degreesC under hot-corrosion conditions (sodium and sodium/potassium sulfates) likely to occur in biomass-derived fuel-fired gas turbines. In contrast to conditions initiating Type I hot-corrosion attack, a modified test procedure was used in this study where periodically salt-coated specimens were subjected to an oxygen atmosphere while SO, was omitted, thus taking into account the essentially sulfur-free biomass fuel-combustion atmosphere. For comparison, similar tests were conducted on bare MCrAlY-type alloys. TBC failure by spallation of the PYSZ coating was observed between 300 and 500 1-hr cycles. Irrespective of PYSZ micsostructure and deposit chemistry, failure was primarily induced by crack formation and propagation within the voluminous oxide scale formed as a result of hot-corrosion attack of the metal, rather than degradation of the ceramic layer. Since the major attack mode of the TBC seemed to be hot corrosion of the bond coat, this paper highlights degradation mechanisms and microstructures of uncoated bond-coat compositions. On the basis of the present results, implications of the failure mode of EB-PVD PPSZ on in-service components are discussed. C1 DLR, German Aerosp Ctr, Inst Mat Res, D-51170 Cologne, Germany. Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Leyens, C (reprint author), DLR, German Aerosp Ctr, Inst Mat Res, D-51170 Cologne, Germany. RI Wright, Ian/A-8300-2008; Pint, Bruce/A-8435-2008 OI Pint, Bruce/0000-0002-9165-3335 NR 23 TC 31 Z9 31 U1 0 U2 22 PU KLUWER ACADEMIC/PLENUM PUBL PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 0030-770X J9 OXID MET JI Oxid. Met. PD DEC PY 2000 VL 54 IS 5-6 BP 401 EP 424 DI 10.1023/A:1004634400479 PG 24 WC Metallurgy & Metallurgical Engineering SC Metallurgy & Metallurgical Engineering GA 380WC UT WOS:000165725600003 ER PT J AU Wehner, BI Koster, U AF Wehner, BI Koster, U TI Microstructural evolution of alumina layers on an Al-Cu-Fe quasicrystal during high-temperature oxidation SO OXIDATION OF METALS LA English DT Article DE quasicrystals; aluminides; oxidation; nodules ID QUASI-CRYSTALLINE; TRANSIENT OXIDATION; SURFACE OXIDATION; ALLOYS; COATINGS; BEHAVIOR; PHASES AB The oxidation of a quasicrystal with the nominal composition Al63CU25Fe12 was studied around 800 degreesC in environmental and synthetic air by means of thermogravimetric analysis, electron microscopy, and analytical electron spectroscopy. In an early oxidation stage, gamma -Al2O3 formed with an orientational relationship to the quasicrystal. At the oxide-metal interface, -gammaAl2O3 transformed into large hexagonal shaped; alpha -Al2O3 grains. The change in surface morphology indicated that at the oxide-gas inteface gamma -Al2O3 continued to grow as Theta -Al2O3. Locally the metastable alumina layer was transformed thoroughly into alpha -Al2O3, which then continued to grow with a nodular morphology. On tap of the oxide nodules, several at.% of Cu2+ were detected. C1 Iowa State Univ Sci & Technol, Ames Lab, Ames, IA 50011 USA. Univ Dortmund, Dept Chem Engn, D-44221 Dortmund, Germany. RP Wehner, BI (reprint author), Iowa State Univ Sci & Technol, Ames Lab, Ames, IA 50011 USA. NR 35 TC 14 Z9 14 U1 0 U2 3 PU KLUWER ACADEMIC/PLENUM PUBL PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 0030-770X J9 OXID MET JI Oxid. Met. PD DEC PY 2000 VL 54 IS 5-6 BP 445 EP 456 DI 10.1023/A:1004638501387 PG 12 WC Metallurgy & Metallurgical Engineering SC Metallurgy & Metallurgical Engineering GA 380WC UT WOS:000165725600005 ER PT J AU Morris, JW Krenn, CR AF Morris, JW Krenn, CR TI The internal stability of an elastic solid SO PHILOSOPHICAL MAGAZINE A-PHYSICS OF CONDENSED MATTER STRUCTURE DEFECTS AND MECHANICAL PROPERTIES LA English DT Article ID METALS; ALUMINUM; STRENGTH; CRYSTALS AB This paper investigates the conditions of elastic stability that set the upper limits of mechanical strength. Following Gibbs, we determine the conditions that ensure stability against reconfigurations that leave the boundary of the system unchanged. The results hold independent of the nature of properties of the loading mechanisms but are identical with those derived previously for a solid in contact with a reservoir that maintains the Cauchy stress. Mechanisms that control the stress in some other way may add further conditions of stability; nonetheless, the conditions of internal stability must always be obeyed and can be consistently used to define the ultimate strength. The conditions of stability are contained in the requirement that lambda (ijkl) delta epsilon (ij) delta epsilon (kl) greater than or equal to 0 for all infinitesimal strains, where lambda (ijkl) = 1/2 (B-ijkl + B-klij), and B is the tensor that governs the change in the Cauchy stress t during incremental strain from a stressed state tau : t(ij) = tau (ij) + B-ijkl delta epsilon (kl). Since lambda has full Voigt symmetry, it can be written as the 6 x 6 matrix lambda (ij) with eigenvalues lambda (alpha). Stability is lost when the least of these vanishes. The conditions of stability are exhibited for cubic (hydrostatic), tetragonal (tensile) and monoclinic (shear) distortions of a cubic crystal and some of their implications are discussed. Elastic stability and the limits of strength are now being explored through first-principles calculations that increment uniaxial stretch or shear to find the maximum stress. We discuss the nature of this limiting stress and the steps that may be taken to identify orthogonal instabilities that might intrude before it is reached. C1 Univ Calif Berkeley, Dept Mat Sci, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Ctr Adv Mat, Berkeley, CA 94720 USA. RP Morris, JW (reprint author), Univ Calif Berkeley, Dept Mat Sci, Berkeley, CA 94720 USA. NR 23 TC 109 Z9 109 U1 1 U2 26 PU TAYLOR & FRANCIS LTD PI LONDON PA 11 NEW FETTER LANE, LONDON EC4P 4EE, ENGLAND SN 0141-8610 J9 PHILOS MAG A JI Philos. Mag. A-Phys. Condens. Matter Struct. Defect Mech. Prop. PD DEC PY 2000 VL 80 IS 12 BP 2827 EP 2840 PG 14 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering; Physics, Applied; Physics, Condensed Matter SC Materials Science; Metallurgy & Metallurgical Engineering; Physics GA 386AA UT WOS:000166036300004 ER PT J AU Keppens, V Sales, BC Mandrus, D Chakoumakos, BC Laermans, C AF Keppens, V Sales, BC Mandrus, D Chakoumakos, BC Laermans, C TI When does a crystal conduct heat like a glass? SO PHILOSOPHICAL MAGAZINE LETTERS LA English DT Article ID FILLED SKUTTERUDITE ANTIMONIDES; LOW-TEMPERATURE PROPERTIES; THERMAL-CONDUCTIVITY; SOLIDS; GE AB Semiconducting crystalline materials that are poor conductors of heat are important as thermoelectric materials and for technological applications involving thermal management. A combination of neutron scattering, low-temperature ultrasonic attenuation and thermal conductivity measurements are reported on single crystals of the semiconductors Sr8Ga16Ge30 and Ba8Ga16Ge30. Taken together, these measurements suggest specific structural features that result in a crystal with the lowest possible thermal conductivity, namely that of a glass with the same chemical composition. Weakly bound atoms that 'rattle' within oversized atomic cages in a crystal result in a low thermal conductivity, but the present data show that both 'rattling' atoms and tunnelling states are necessary to produce a true glass-like thermal conductivity. C1 Univ Mississippi, Natl Ctr Phys Acoust, University, MS 38677 USA. Oak Ridge Natl Lab, Div Solid State, Oak Ridge, TN 37831 USA. Katholieke Univ Leuven, Dept Phys, B-3001 Louvain, Belgium. RP Keppens, V (reprint author), Univ Mississippi, Natl Ctr Phys Acoust, University, MS 38677 USA. RI Mandrus, David/H-3090-2014; Chakoumakos, Bryan/A-5601-2016 OI Chakoumakos, Bryan/0000-0002-7870-6543 NR 18 TC 48 Z9 48 U1 3 U2 17 PU TAYLOR & FRANCIS LTD PI LONDON PA 11 NEW FETTER LANE, LONDON EC4P 4EE, ENGLAND SN 0950-0839 J9 PHIL MAG LETT JI Philos. Mag. Lett. PD DEC PY 2000 VL 80 IS 12 BP 807 EP 812 DI 10.1080/09500830010003830 PG 6 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering; Physics, Applied; Physics, Condensed Matter SC Materials Science; Metallurgy & Metallurgical Engineering; Physics GA 382BP UT WOS:000165798800008 ER PT J AU Kroon, RE Neethling, JH Zolper, JC AF Kroon, RE Neethling, JH Zolper, JC TI Transmission electron microscopy of Be implanted Si-doped GaAs SO PHYSICA STATUS SOLIDI A-APPLIED RESEARCH LA English DT Article ID GALLIUM-ARSENIDE; ACTIVATION; DIFFUSION AB Be ions were implanted into degenerately Si-doped GaAs at 300 keV to a dose of 10(15) cm(-2). The region near the projected range remained crystalline, and subthreshold defects formed at this depth after annealing at 450-500 degreesC. The defects are identified as circular prismatic perfect interstitial loops on the {110} planes, originating after the annealing of defect clusters near 400 degreesC. The Burgers vector of these loops was computed using the comparison of experimental and computed defect intensity profiles. The formation of only interstitial loops is attributed to the dislocation bias effect, whereby interstitials are attracted more strongly to dislocations than vacancies. A high density of small loops with {110} and {111} habit planes were observed to form slightly shallower than the projected range after annealing at 600 degreesC and extend closer to the surface after annealing at 700 degreesC. The density of these loops decreased, and their size increased, after annealing at 800 degreesC. However, they remained small compared to the loops near the projected range. A shift of the loop area per unit volume profile slightly deeper into the material after annealing at 600 degreesC or higher (as compared to annealing at 500 degreesC) resulted from the formation of loops as interstitials diffused deeper into the material, while interstitials diffusing to shallower regions were annihilated by the excess vacancy concentration in this region developed due to knock-on during implantation. The decreased size of the loops found in this study as compared to those reported previously is suggested to be as a result of the use of degenerately Si-doped rather than semi-insulating GaAs. C1 Univ Port Elizabeth, Dept Phys, ZA-6000 Port Elizabeth, South Africa. Sandia Natl Labs, Albuquerque, NM 87123 USA. RP Kroon, RE (reprint author), Univ Port Elizabeth, Dept Phys, POB 1600, ZA-6000 Port Elizabeth, South Africa. RI Kroon, Robin/A-1793-2013 OI Kroon, Robin/0000-0001-9728-9370 NR 40 TC 1 Z9 1 U1 0 U2 0 PU WILEY-V C H VERLAG GMBH PI BERLIN PA PO BOX 10 11 61, D-69451 BERLIN, GERMANY SN 0031-8965 J9 PHYS STATUS SOLIDI A JI Phys. Status Solidi A-Appl. Res. PD DEC PY 2000 VL 182 IS 2 BP 607 EP 617 DI 10.1002/1521-396X(200012)182:2<607::AID-PSSA607>3.0.CO;2-M PG 11 WC Materials Science, Multidisciplinary; Physics, Applied; Physics, Condensed Matter SC Materials Science; Physics GA 389GG UT WOS:000166229800007 ER PT J AU Cancio, AC Fong, CY Nelson, JS AF Cancio, AC Fong, CY Nelson, JS TI Exchange-correlation hole of the Si atom: A quantum Monte Carlo study SO PHYSICAL REVIEW A LA English DT Article ID PAIR-DENSITY INTERPRETATION; POLARIZED ELECTRON-GAS; WAVE-FUNCTIONS; GRADIENT APPROXIMATION; CORRELATION-ENERGY; PSEUDOPOTENTIALS; SYSTEMS; SILICON; WORK AB We have studied the exchange-correlation hole n(xc) and pair-correlation function in the valence shell of the Si atom in its P-3 ground state, using highly accurate Slater-Jastrow wave functions and the variational Monte Carlo method. The exchange-correlation hole shows a number of interesting features caused by the open shell structure of Si, including a marked transition from efficient to poor screening behavior as a test majority-spin electron is moved from the center of a valence p orbital onto the axis perpendicular to the occupied p orbitals. This behavior results from the dramatic difference in the exchange hole in the two cases, which is partially compensated by a corresponding anisotropy in the correlation hole. In addition we observe an anisotropic change in the spin density induced by Coulomb correlation, reducing the spatial overlap between the different spin components of the density and contributing to the anisotropy of the correlation hole. The exclusion effect correlation, in which a 3s(2-)-->3p(2) substitution excitation is allowed along the unoccupied axis and prohibited along the other axes, was found to have a noticeable effect on the correlation hole and is partially accountable for its anisotropy; however, it is inconsistent with the observed changes in spin density. In contrast to the longer-range features, we find that the "on-top" correlation hole is well described by linear density-functional theory for a large range of local density and magnetization. C1 Univ Calif Davis, Dept Phys, Davis, CA 95616 USA. Sandia Natl Labs, Semicond Phys Div, Albuquerque, NM 87185 USA. RP Cancio, AC (reprint author), Georgia Tech, Sch Phys, Atlanta, GA 30332 USA. NR 40 TC 8 Z9 8 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 DEC PY 2000 VL 62 IS 6 AR 062507 PG 14 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA 380JC UT WOS:000165697200038 ER PT J AU Cheng, WT Kukk, E Cubaynes, D Chang, JC Snell, G Bozek, JD Wuilleumier, FJ Berrah, N AF Cheng, WT Kukk, E Cubaynes, D Chang, JC Snell, G Bozek, JD Wuilleumier, FJ Berrah, N TI Measurements and calculations of high-angular-momentum satellite transitions in Li 1s photoionization SO PHYSICAL REVIEW A LA English DT Article ID INNER-SHELL PHOTOIONIZATION; FINAL-STATE SYMMETRY; CROSS-SECTION; TRIPLE PHOTOIONIZATION; EXCITED LITHIUM; ATOMIC LITHIUM; HOLLOW LITHIUM; GROUND-STATE; HELIUM; THRESHOLD AB Lithium is photoelectron spectra are reported in high electron and photon energy resolution, with resolved LS term structure of the Li+ 1 nl satellite transitions up to n = 6. Branching ratios and anisotropy parameters of individual lints, determined over the 85-130 eV photon energy range, are compared with R-matrix calculations and with previous works. The high-angular-momentum satellite lines (L greater than or equal to2) are found to contribute significantly to the 1 snl satellite; cross sections for n=3 and 4, and to become the dominant terms for n greater than or equal to5. The high-angular-momentum lines exhibit the same photon-energy-dependence as the P-lines, providing experimental evidence that the continuum-continuum state coupling (equivalent to virtual electron collision processes) is responsible for the L greater than or equal to1 terms in the satellite spectrum, in contrast to the electron relaxation (shake-up) mechanism responsible for the 5-terms. The angular distribution of the lines in the Li+ 1 snl, rt = 2-6 groups, determined at 110 eV photon energy, is in good agreement with calculations, showing more isotropic distributions for high-angular-momentum lines. C1 Western Michigan Univ, Dept Phys, Kalamazoo, MI 49008 USA. Natl Cent Univ, Dept Phys, Chungli 32054, Taoyuan, Taiwan. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. Univ Paris 11, Lab Spect Atom & Ion, CNRS, UMR 8624, F-91405 Orsay, France. Natl Hsinchu Teachers Coll, Dept Math & Sci Educ, Hsinchu 300, Taiwan. RP Cheng, WT (reprint author), Western Michigan Univ, Dept Phys, Kalamazoo, MI 49008 USA. RI Bozek, John/E-4689-2010; Bozek, John/E-9260-2010 OI Bozek, John/0000-0001-7486-7238 NR 63 TC 12 Z9 12 U1 1 U2 1 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1050-2947 J9 PHYS REV A JI Phys. Rev. A PD DEC PY 2000 VL 62 IS 6 AR 062509 DI 10.1103/PhysRevA.62.062509 PG 9 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA 380JC UT WOS:000165697200040 ER PT J AU Khibnik, AI Braiman, Y Protopopescu, V Kennedy, TAB Wiesenfeld, K AF Khibnik, AI Braiman, Y Protopopescu, V Kennedy, TAB Wiesenfeld, K TI Amplitude dropout in coupled lasers SO PHYSICAL REVIEW A LA English DT Article ID SOLID-STATE LASER; ND-YVO4 MICROCHIP LASERS; DIODE-LASERS; SEMICONDUCTOR-LASERS; PHASE-LOCKING; ARRAYS; INJECTION; DYNAMICS; SYNCHRONIZATION; STABILITY AB We study the entrainment or coupled solid-state lasers by an external injected field. We show that the total output intensity exhibits unexpected nonmonotonic behavior as a function of the injected field and find the critical amplitude marking the transition to the low-intensity branch. In addition, we also show that substantial partial entrainment can be achieved for injected fields much weaker than that required fur full entrainment. C1 United Technol Res Ctr, E Hartford, CT 06108 USA. Oak Ridge Natl Lab, Div Math & Comp Sci, Ctr Engn Sci Adv Res, Oak Ridge, TN 37831 USA. Georgia Inst Technol, Sch Phys, Atlanta, GA 30332 USA. RP Khibnik, AI (reprint author), United Technol Res Ctr, 411 Silver Lane,MS 129-15, E Hartford, CT 06108 USA. NR 33 TC 8 Z9 8 U1 0 U2 4 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1050-2947 J9 PHYS REV A JI Phys. Rev. A PD DEC PY 2000 VL 62 IS 6 AR 063815 DI 10.1103/PhysRevA.62.063815 PG 5 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA 380JC UT WOS:000165697200110 ER PT J AU Guedes, I Mitchell, JF Argyriou, D Grimsditch, M AF Guedes, I Mitchell, JF Argyriou, D Grimsditch, M TI Oxygen stoichiometry in Sr3Mn2O7-delta: A Raman scattering investigation SO PHYSICAL REVIEW B LA English DT Article ID GIANT MAGNETORESISTANCE; MANGANITES; MAGNETOTRANSPORT; LA1.2SR1.8MN2O7; SPECTROSCOPY AB Polycrystalline Sr3Mn2O6.5 and Sr3Mn2O7 layered manganites were studied at room temperature using Raman spectroscopy. While the phonon spectrum of the stoichiometric Sr3Mn2O7 sample is consistent with the group theoretical analysis for the 14/mmm structure, additional features are observed in the phonon spectrum of the oxygen deficient Sr3Mn2O6.5 sample. Based on an analysis of the temperature dependence of the Raman spectrum of Sr3Mn2O6.5 and a comparison with the Raman spectrum of La0.4Sr2.6Mn2O7-delta (delta= 0.0 and 0.35), we conclude that the 'extra' modes should be viewed as disorder induced Raman scattering. C1 Argonne Natl Lab, Div Sci Mat, Argonne, IL 60439 USA. RP Guedes, I (reprint author), Argonne Natl Lab, Div Sci Mat, Argonne, IL 60439 USA. RI GUEDES, ILDE/C-3451-2013; UFC, DF/E-1564-2017; Universidade Federal do Ceara, Physics Department/J-4630-2016; OI Universidade Federal do Ceara, Physics Department/0000-0002-9247-6780; GUEDES, ILDE/0000-0002-1040-5891 NR 17 TC 1 Z9 1 U1 1 U2 7 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 DEC 1 PY 2000 VL 62 IS 21 BP 13809 EP 13811 DI 10.1103/PhysRevB.62.13809 PG 3 WC Physics, Condensed Matter SC Physics GA 380RL UT WOS:000165717200004 ER PT J AU Roy, M Mitchell, JF Ramirez, AP Schiffer, P AF Roy, M Mitchell, JF Ramirez, AP Schiffer, P TI Soft spin waves in the low-temperature thermodynamics of Pr0.7Ca0.3MnO3 SO PHYSICAL REVIEW B LA English DT Article ID INSULATOR-METAL TRANSITION; MAGNETIC-FIELD; NEUTRON-DIFFRACTION; PR1-XCAXMNO3; MANGANITES; MAGNETORESISTANCE; LA0.7SR0.3MNO3; FERROMAGNET; 3D AB We present a detailed magnetothermal study of Pr0.7Ca0.3MnO3, a perovskite manganite in which an insulator-metal transition can be driven by magnetic field, but also by pressure, visible light, x rays, or high currents. Ne find that the field-induced transition is associated with an enormous release of energy which accounts far its strong irreversibility. In the ferromagnetic metallic state, specific heat and magnetization measurements indicate a much smaller spin-wave stiffness than that seen in any other manganite, which we attribute to spin waves among the ferromagnetically ordered Pr moments. The coupling between the Pr and Mn spins may also provide a basis for understanding the low-temperature phase diagram of this most unusual manganite. C1 Univ Notre Dame, Dept Phys, Notre Dame, IN 46556 USA. Argonne Natl Lab, Div Sci Mat, Argonne, IL 60439 USA. Bell Labs, Lucent Technol, Murray Hill, NJ 07974 USA. RP Schiffer, P (reprint author), Penn State Univ, Dept Phys, University Pk, PA 16802 USA. EM schiffer@phys.psu.edu RI Schiffer, Peter/F-3227-2011 NR 35 TC 20 Z9 20 U1 0 U2 3 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 EI 1550-235X J9 PHYS REV B JI Phys. Rev. B PD DEC 1 PY 2000 VL 62 IS 21 BP 13876 EP 13879 DI 10.1103/PhysRevB.62.13876 PG 4 WC Physics, Condensed Matter SC Physics GA 380RL UT WOS:000165717200021 ER PT J AU Cassinese, A Iavarone, M Vaglio, R Grimsditch, M Uran, S AF Cassinese, A Iavarone, M Vaglio, R Grimsditch, M Uran, S TI Transport properties of ZrN superconducting films SO PHYSICAL REVIEW B LA English DT Article ID SPIN FLUCTUATIONS; RESISTIVITY; NB; VN AB Superconductivity in nitrides presents intriguing aspects related to the role of optical phonons. In the present paper we report on high-quality superconducting zirconium nitride film preparation and characterization (including Raman scattering) as well as on both de and microwave frequency transport properties, The high-temperature dc resistivity shows no evidence of saturation effects, possibly due to the low electron-phonon coupling. Surface impedance data can be well fitted by the standard BCS expressions. The data provide further evidence of the ''conventional'' nature of superconductivity in these compounds. C1 Univ Naples, INFM, Dipartimento Sci Fis, I-80125 Naples, Italy. Argonne Natl Lab, Div Sci Mat, Argonne, IL 60439 USA. RP Cassinese, A (reprint author), Univ Naples, INFM, Dipartimento Sci Fis, Piazzale Techio 80, I-80125 Naples, Italy. RI Iavarone, Maria/C-3628-2008; antonio, cassinese/J-7274-2012 OI antonio, cassinese/0000-0002-5866-223X NR 19 TC 20 Z9 20 U1 0 U2 10 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 DEC 1 PY 2000 VL 62 IS 21 BP 13915 EP 13918 DI 10.1103/PhysRevB.62.13915 PG 4 WC Physics, Condensed Matter SC Physics GA 380RL UT WOS:000165717200031 ER PT J AU Fournee, V Pinhero, PJ Anderegg, JW Lograsso, TA Ross, AR Canfield, PC Fisher, IR Thiel, PA AF Fournee, V Pinhero, PJ Anderegg, JW Lograsso, TA Ross, AR Canfield, PC Fisher, IR Thiel, PA TI Electronic structure of quasicrystalline surfaces: Effects of surface preparation and bulk structure SO PHYSICAL REVIEW B LA English DT Article ID AL-PD-MN; ICOSAHEDRAL QUASI-CRYSTALS; RESOLUTION PHOTOEMISSION SPECTROSCOPY; HUME-ROTHERY ALLOYS; X-RAY PHOTOEMISSION; SPECTRA; PHASE; LEED; DIFFRACTION; AL68PD23MN9 AB We elucidate the nature of the surface electronic properties of quasicrystalline Al-Pd-Mn. We do this by using photoelectron and Auger electron spectroscopies, and by making a variety of comparisons-across types of bulk samples, and across methods of surface preparation. The main conclusions are these: (i) The narrow Mn 2P(3/2) core-level line observed in the icosahedral phase is a fingerprint of a suppression in the density of states (a pseudogap) at the Fermi level and is Pot unique to the quasicrystalline phase. It is also independent of the symmetry of the quasicrystalline surface. The Auger line shape is also affected and may be used as a fingerprint of a pseudogap. (ii) A similarly narrow Fe 2P3/2 core-level line characterizes the icosahedral Al-Cu-Fe quasicrystal, consistent with the expectation that the electronic structure is of general importance in the stabilization of icosahedral phases. (iii) In icosahedral AI-Pd-Mn, the pseudogap of the bulk is not retained up to the surface immediately after fracture, but can be restored by annealing, or by sputter annealing to sufficiently high temperatures. Assuming that the pseudogap reflects an electronic stabilization of the atomic structure, these results suggest that the heat-treated surfaces are more stable than the surface obtained by fracturing at room temperature. C1 Iowa State Univ, Ames Lab, Ames, IA 50011 USA. Iowa State Univ, Dept Mat Sci & Engn, Ames, IA 50011 USA. Iowa State Univ, Dept Phys & Astron, Ames, IA 50011 USA. Iowa State Univ, Dept Chem, Ames, IA 50011 USA. RP Fournee, V (reprint author), Iowa State Univ, Ames Lab, Ames, IA 50011 USA. RI Canfield, Paul/H-2698-2014 NR 61 TC 33 Z9 34 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 DEC 1 PY 2000 VL 62 IS 21 BP 14049 EP 14060 DI 10.1103/PhysRevB.62.14049 PG 12 WC Physics, Condensed Matter SC Physics GA 380RL UT WOS:000165717200050 ER PT J AU Cornelius, AL Arko, AJ Sarrao, JL Hundley, MF Fisk, Z AF Cornelius, AL Arko, AJ Sarrao, JL Hundley, MF Fisk, Z TI Anisotropic electronic and magnetic properties of the quasi-two-dimensional heavy-fermion antiferromagnet CeRhIn5 SO PHYSICAL REVIEW B LA English DT Article ID HAAS-VAN-ALPHEN; PHASE-TRANSITIONS; SURFACE; OSCILLATIONS; DEHAAS; FIELDS; (TMTSF)(2)PF6; TEMPERATURE; DEPENDENCE; URU2SI2 AB We have used high pulsed magnetic fields to 50 T to observe de Haas-van Alphen oscillations in the tetragonal antiferromagnet CeRhIn5, which has an enhanced value of the electronic specific heat coefficient gamma greater than or similar to 420 mJ/mol K-2. For T cm), isostructural with GdFeO3 (space group Pnma). The Mn-O-Mn angles remain nearly constant from x=0 to x=0.25, while the Mn-O distances steadily increase with the Mn3+ content. Three distinct phases are observed at 25 K. The first one, observed from 0.15 greater than or equal to x greater than or equal to0.03, is characterized by the absence of charge and orbital ordering, a canted G-type antiferromagnetic spin structure, and delocalized electron transport. The second phase, observed from 0.25 greater than or equal tox greater than or equal to0.12 (single phase at x= 0.18), is characterized by pronounced orbital ordering, a C-type antiferromagnetic spin structure, and insulating behavior. The third low-temperature phase, observed for x greater than or equal to 0.20, is characterized by orbital and magnetic ordering similar to the Wigner crystal structure previously observed for Ca0.67La0.33MnO3, but with a 4a x b x 2c unit cell. The most striking feature of the phase diagram is the wide compositional range over which low-temperature phase separation is observed. Only those samples with x<0.12 and x = 0.18 did not undergo phase separation upon cooling. We show that this behavior cannot be attributed to compositional variations, and therefore, propose that anisotropic strain interactions between crystallites may be partially responsible for this behavior. C1 Ohio State Univ, Dept Chem, Columbus, OH 43210 USA. Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. Ohio State Univ, Dept Phys, Columbus, OH 43210 USA. RP Santhosh, PN (reprint author), Ohio State Univ, Dept Chem, 100 W 18Th Ave, Columbus, OH 43210 USA. RI Goldberger, Joshua/F-5484-2011; Vogt, Thomas /A-1562-2011; Goldberger, Joshua/N-8963-2016 OI Goldberger, Joshua/0000-0003-4284-604X; Vogt, Thomas /0000-0002-4731-2787; Goldberger, Joshua/0000-0003-4284-604X NR 43 TC 39 Z9 39 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 DEC 1 PY 2000 VL 62 IS 22 BP 14928 EP 14942 DI 10.1103/PhysRevB.62.14928 PG 15 WC Physics, Condensed Matter SC Physics GA 383LJ UT WOS:000165883800050 ER PT J AU Batista, CD Eroles, J Avignon, M Alascio, B AF Batista, CD Eroles, J Avignon, M Alascio, B TI Ferromagnetic polarons in manganites SO PHYSICAL REVIEW B LA English DT Article ID COMPETING DOUBLE EXCHANGE; PHASE-DIAGRAM; KONDO MODEL; NEGATIVE MAGNETORESISTANCE; SUPEREXCHANGE INTERACTIONS; ELECTRONIC MODELS; PEROVSKITE; CHARGE; LA1-XCAXMNO3; SEPARATION AB Using the Lanczos method in linear chains we study the double exchange model in the low concentration limit, including an antiferromagnetic super-exchange K. In the strong-coupling limit we find that the ground state contains ferromagnetic polarons whose length is very sensitive to the value of Kit. We investigate the dispersion relation, the trapping by impurities, and the interaction between these polarons. As the overlap between polarons increases, by decreasing Kit, the effective interaction between them changes from antiferromagnetic to ferromagnetic. The scaling to the thermodynamic limit suggests an attractive interaction in the strong-coupling regime (J(h)>t) and no binding in the weak limit (J(h)similar or equal tot). C1 Ctr Atom Bariloche, RA-8400 San Cartos De Bariloche, Argentina. Univ Grenoble 1, Etud Proprietes Elect Solides Lab, CNRS, F-38042 Grenoble 9, France. Inst Balseiro, RA-8400 San Cartos De Bariloche, Argentina. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Batista, CD (reprint author), Ctr Atom Bariloche, RA-8400 San Cartos De Bariloche, Argentina. RI Batista, Cristian/J-8008-2016 NR 40 TC 16 Z9 16 U1 1 U2 3 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 EI 1550-235X J9 PHYS REV B JI Phys. Rev. B PD DEC 1 PY 2000 VL 62 IS 22 BP 15047 EP 15055 DI 10.1103/PhysRevB.62.15047 PG 9 WC Physics, Condensed Matter SC Physics GA 383LJ UT WOS:000165883800060 ER PT J AU Wiener, TA Fisher, IR Bud'ko, SL Kracher, A Canfield, PC AF Wiener, TA Fisher, IR Bud'ko, SL Kracher, A Canfield, PC TI Design of a metallic Ising spin glass in the Y1-xTbxNi2Ge2 system SO PHYSICAL REVIEW B LA English DT Article ID R = Y; CRYSTALS AB There has been much interest in the past ten years in the effects of applying a transverse magnetic field on the freezing temperature of Ising spin glasses. The focus of this study is to search for and characterize a metallic Ising spin-glass system. This is accomplished by site diluting yttrium for terbium in the crystalline material TbNi2Ge2. Pure TbNi2Ge2 is an Ising antiferromagnet with several distinct magnetic states below 17 K. As the terbium is diluted with yttrium, magnetic coupling and ordering temperatures are suppressed in a monotonic way, as is seen in measurements of the transition temperatures and analysis of the high-temperature Curie-Weiss behavior. At low concentrations of terbium, below x similar to 0.35, long-range order is no longer detected and a spin-glass-like state emerges. This state is studied through a variety of measurements: dc and ac susceptibility, resistivity, and specific heat. These data are then compared to that of other well characterized spin-glass systems. It is concluded that there is a region of concentrations for which an Ising spin-glass state is formed with the best spin glasses existing for x less than or equal to0.30. C1 Iowa State Univ Sci & Technol, Ames Lab, Ames, IA 50011 USA. Iowa State Univ Sci & Technol, Dept Phys & Astron, Ames, IA 50011 USA. Iowa State Univ Sci & Technol, Dept Geol & Atmospher Sci, Ames, IA 50011 USA. RP Wiener, TA (reprint author), Iowa State Univ Sci & Technol, Ames Lab, Ames, IA 50011 USA. RI Canfield, Paul/H-2698-2014 NR 20 TC 9 Z9 9 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 DEC 1 PY 2000 VL 62 IS 22 BP 15056 EP 15066 DI 10.1103/PhysRevB.62.15056 PG 11 WC Physics, Condensed Matter SC Physics GA 383LJ UT WOS:000165883800061 ER PT J AU Cyrille, MC Kim, S Gomez, ME Santamaria, J Leighton, C Krishnan, KM Schuller, IK AF Cyrille, MC Kim, S Gomez, ME Santamaria, J Leighton, C Krishnan, KM Schuller, IK TI Effect of sputtering pressure-induced roughness on the microstructure and the perpendicular giant magnetoresistance of Fe/Cr superlattices SO PHYSICAL REVIEW B LA English DT Article ID X-RAY REFLECTIVITY; MAGNETIC MULTILAYERS; INTERFACIAL ROUGHNESS; DIFFRACTION; TRANSPORT; PARALLEL; PLANE; FILMS AB We have studied the connection between structure and magnetism of Fe/Cr superlattices as a function of sputtering pressure. To measure the perpendicular giant magnetoresistance, we have fabricated microstructured Fe/Cr pillars embedded in SiO2 and interconnected with Nb electrodes. Because of the uniform current distribution in the Nb electrodes and the minimization of the superlattice-electrode contact resistance, the method allows a simple and independent measurement of the perpendicular superlattice resistance and giant magnetoresistance. A detailed quantitative structural analysis by x-ray diffraction, transmission electron microscopy, and high spatial resolution electron-energy-loss spectroscopy imaging, was correlated with magnetization and anisotropic magnetotransport properties. Structural characterization of [Fe(3 nm)/Cr(1.3 nm)](20), superlattices indicate that the roughness increases monotonically with pressure. The current perpendicular to the plane giant magnetoresistance was also found to increase with pressure. This is interpreted as arising from an enhanced spin-dependent scattering. C1 Univ Calif San Diego, Dept Phys, La Jolla, CA 92093 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Natl Ctr Electron Microscopy, Berkeley, CA 94720 USA. RP Cyrille, MC (reprint author), Univ Calif San Diego, Dept Phys, La Jolla, CA 92093 USA. RI Santamaria, Jacobo/N-8783-2016 OI Santamaria, Jacobo/0000-0003-4594-2686 NR 30 TC 19 Z9 19 U1 1 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 DEC 1 PY 2000 VL 62 IS 22 BP 15079 EP 15083 DI 10.1103/PhysRevB.62.15079 PG 5 WC Physics, Condensed Matter SC Physics GA 383LJ UT WOS:000165883800063 ER PT J AU Ling, CD Millburn, JE Mitchell, JF Argyriou, DN Linton, J Bordallo, HN AF Ling, CD Millburn, JE Mitchell, JF Argyriou, DN Linton, J Bordallo, HN TI Interplay of spin and orbital ordering in the layered colossal magnetoresistance manganite La2-2xSr1+2xMn2O7 (0.5 <= x <= 1.0) SO PHYSICAL REVIEW B LA English DT Article ID T-C; NEUTRON-DIFFRACTION; MAGNETIC-PROPERTIES; TUNNELING MAGNETORESISTANCE; LA1.2SR1.8MN2O7; LASR2MN2O7; TRANSITIONS; CRYSTAL; STATE; LA1-XCAXMNO3 AB The crystallographic and magnetic phase diagram of the n = 2 layered manganite La2-2xSr1+ 2xMn2O7 in the region x greater than or equal to0.5 has been studied using temperature-dependent neutron powder diffraction. The magnetic phase diagram reveals a progression of ordered magnetic structures generally paralleling that of three-dimensional (3D) perovskites with similar electronic doping: A (0.5 less than or equal tox less than or equal to0.66)-->C (0.75 less than or equal tox less than or equal to0.90)-->G (0.90 less than or equal tox less than or equal to1.0). However, the quasi-2D structure amplifies this progression to expose features of manganite physics uniquely accessible in the layered systems: (i) a ''frustrated'' region between the A and C regimes where no long-range magnetic order is observed; (ii) magnetic polytypism arising from weak interbilayer magnetic exchange in the type-C regime; and (iii) a tetragonal-to-orthorhombic phase transition whose temperature evolution directly measures ordering of d(3y2-r2) orbitals in the a-b plane. This orbital-ordering transition is precursory to type-C magnetic ordering, where ferromagnetic rods lie parallel to the b axis. These observations support the notion that e(g) orbital polarization is the driving force behind magnetic spin ordering. Finally, in the crossover region between type-C and type-G states, we see some evidence for the development of local type-C clusters embedded in a type-G framework, directly addressing proposals of similar short-range magnetic ordering in highly doped La1-xCaxMnO3 perovskites. C1 Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. Argonne Natl Lab, Intense Pulsed Neutron Source, Argonne, IL 60439 USA. RP Ling, CD (reprint author), Argonne Natl Lab, Div Mat Sci, 9700 S Cass Ave, Argonne, IL 60439 USA. RI Ling, Chris D/B-2228-2009; Bordallo, Heloisa/I-6836-2012 OI Ling, Chris D/0000-0003-2205-3106; Bordallo, Heloisa/0000-0003-0750-0553 NR 42 TC 115 Z9 116 U1 1 U2 17 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 DEC 1 PY 2000 VL 62 IS 22 BP 15096 EP 15111 DI 10.1103/PhysRevB.62.15096 PG 16 WC Physics, Condensed Matter SC Physics GA 383LJ UT WOS:000165883800065 ER PT J AU Abrikosov, AA AF Abrikosov, AA TI Fine structure of the neutron maximum in high-temperature superconducting cuprates SO PHYSICAL REVIEW B LA English DT Article ID VANHOVE SINGULARITIES; FERMI-SURFACE; YBA2CU4O8 AB A calculation is performed of the imaginary part of the electron magnetic susceptibility, as function of energy and momentum in the vicinity of the maximum of the inelastic neutron scattering. Compared to the previous calculation a slight bending of the energy bands in the vicinity of extended saddle point singularities is taken into account. It is shown that this simple picture fits qualitatively the recently observed experimental data on the fine structure in momentum space of the inelastic neutron scattering cross section in the vicinity of the maximum at different energies. C1 Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. RP Abrikosov, AA (reprint author), Argonne Natl Lab, Div Mat Sci, 9700 S Cass Ave, Argonne, IL 60439 USA. NR 13 TC 12 Z9 12 U1 1 U2 1 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 EI 1550-235X J9 PHYS REV B JI Phys. Rev. B PD DEC 1 PY 2000 VL 62 IS 22 BP 15156 EP 15161 DI 10.1103/PhysRevB.62.15156 PG 6 WC Physics, Condensed Matter SC Physics GA 383LJ UT WOS:000165883800071 ER PT J AU Morr, DK Pines, D AF Morr, DK Pines, D TI Magnetic coherence as a universal feature of cuprate superconductors SO PHYSICAL REVIEW B LA English DT Article ID FLUCTUATIONS; YBA2CU3O6.6; TEMPERATURE; LA2-XSRXCUO4; SCATTERING; DEPENDENCE; GAP AB We extend our previous work on the magnetic coherence effect in La2-xSrxCuO4 in which it was shown that the effect arises from the interplay of an incommensurate magnetic response, the form of the underlying Fermi surface, and the opening of the d-wave gap in the fermionic spectrum. We present predictions for the magnetic coherence effect in parts of the magnetic Brillouin zone so far unexplored by inelastic neutron scattering (INS) experiments including parts where the so-called spin gap vanishes. We calculate the magnetic coherence effect expected in the superconducting state of YBa2Cu3O6+x, and make derailed predictions for its frequency and momentum dependence. To the extent that our predictions are confirmed by future experiments, our work will demonstrate that INS experiments are riot confined to providing information on the magnetic excitation spec trum, but can also probe the electronic spectrum in the superconducting state. C1 Univ Calif Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. Univ Calif Los Alamos Natl Lab, Inst Complex Adapt Matter, Los Alamos, NM 87545 USA. Univ Calif Los Alamos Natl Lab, LANSCE Div, Los Alamos, NM 87545 USA. RP Morr, DK (reprint author), Univ Calif Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. NR 21 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 DEC 1 PY 2000 VL 62 IS 22 BP 15177 EP 15182 DI 10.1103/PhysRevB.62.15177 PG 6 WC Physics, Condensed Matter SC Physics GA 383LJ UT WOS:000165883800074 ER PT J AU Abfalterer, WP Finlay, RW Grimes, SM AF Abfalterer, WP Finlay, RW Grimes, SM TI Level widths and level densities of nuclei in the 32 <= A <= 60 mass region inferred from fluctuation analysis of total neutron cross sections SO PHYSICAL REVIEW C LA English DT Article ID SPECTRA; SI-29 AB Level widths and level densities of nuclei in the 32 less than or equal toA less than or equal to 60 mass region are inferred from the fluctuation analysis of total neutron cross sections. The experimentally determined level densities are compared to phenomenological and microscopic predictions. The total neutron cross sections were measured in the 0.75 less than or equal toE(n) less than or equal to 11.3 MeV range for (31)p, S-32, K-39, V-51, Fe-56, and Co-59 using a white neutron source and standard time-of-flight techniques. Measured cross sections agree well in magnitude and structure with earlier measurements. Nuclear level widths and cross section variances were determined for the compound nuclei P-32, S-33, K-40, V-52, Fe-57, and Co-60 by means of Fourier analysis of the fluctuating excitation functions and subsequent least squares fit to the resulting In Sk spectra. Nuclear level densities for the above compound nuclei were extracted by relating them to the variance (variance method) of the total neutron cross sections via Ericson theory of fluctuating cross sections. Furthermore, level density values were derived by relating level densities to average level widths (gamma method) via compound nuclear theory. The present study shows good agreement between the two methods for P-32 and S-33, With an uncertainty of 30-40 %. Inclusion of a finite energy resolution correction and use of local instead of global optical model parameters improve agreement, but do not resolve the discrepancy between the two methods completely, especially for A>40. Nuclear level densities were compared with microscopic calculations utilizing a BCS pairing Hamiltonian and specific sets of realistic sets of single-particle energies. A further comparison was made with results obtained from phenomenological models based on the Fermi gas formalism. For P-32, S-33, and K-40, experimental values and phenomenological predictions agree well, but diverge with increasing A. From least squares fits to the present level density data, level density parameters (a and Delta) were extracted for P-32, S-33 and K-40. Results for the level density parameter are consistent with a =A/9. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Ohio Univ, Athens, OH 45701 USA. RP Abfalterer, WP (reprint author), Univ Calif Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. NR 71 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 DEC PY 2000 VL 62 IS 6 AR 064312 PG 21 WC Physics, Nuclear SC Physics GA 381CH UT WOS:000165744400023 ER PT J AU Ahmad, I Carpenter, MP Chasman, RR Greene, JP Janssens, RVF Khoo, TL Kondev, FG Lauritsen, T Lister, CJ Reiter, P Seweryniak, D Sonzogni, A Uusitalo, J Wiedenhover, I Bhattacharyya, P AF Ahmad, I Carpenter, MP Chasman, RR Greene, JP Janssens, RVF Khoo, TL Kondev, FG Lauritsen, T Lister, CJ Reiter, P Seweryniak, D Sonzogni, A Uusitalo, J Wiedenhover, I Bhattacharyya, P TI Energy levels in Cf-251(98) populated in the alpha decay of Fm-255(100) SO PHYSICAL REVIEW C LA English DT Article ID SINGLE-PARTICLE STATES; SUPERHEAVY ELEMENTS; NUCLEI AB Gamma-ray spectra of a 20-h Fm-255 source containing similar to1 mCi activity were measured with a 25% Ge detector and a low-energy photon spectrometer (LEPS). Gamma lines with intensities as low as 1.0 x 10(-6)% per 255Fm, decay were observed. Gamma-gamma coincidence spectra of a Fm-255 Sample were measured with the GAMMASPHERE array. A comparison of the gamma -ray spectrum gated by the Cf K alpha x-ray peak with the gamma -singles spectrum provided spins of the excited states in Cf-251. The gamma -ray data, in conjunction with previously measured Cf-250(d,p) reaction data, allowed us to characterize several single-particle and vibrational states above the N = 152 subshell gap. C1 Argonne Natl Lab, Argonne, IL 60439 USA. Purdue Univ, W Lafayette, IN 47909 USA. RP Greene, JP (reprint author), Argonne Natl Lab, 9700 S Cass Ave, Argonne, IL 60439 USA. RI Carpenter, Michael/E-4287-2015 OI Carpenter, Michael/0000-0002-3237-5734 NR 21 TC 29 Z9 29 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2813 J9 PHYS REV C JI Phys. Rev. C PD DEC PY 2000 VL 62 IS 6 AR 064302 DI 10.1103/PhysRevC.62.064302 PG 5 WC Physics, Nuclear SC Physics GA 381CH UT WOS:000165744400013 ER PT J AU Allgower, CE Ball, J Barabash, LS Beauvais, PY Beddo, ME Borisov, N Boutefnouchet, A Bystricky, J Chamouard, PA Combet, M Demierre, P Fontaine, JM Ghazikhanian, V Grosnick, DP Hess, R Janout, Z Janout, ZF Kalinnikov, VA Kasprzyk, TE Kazarinov, YM Khachaturov, BA Kunne, R Lehar, F de Lesquen, A Lopiano, D de Mali, M Matafonov, VN Pisarev, IL Popov, AA Prokofiev, AN Rapin, D Sans, JL Spinka, HM Usov, YA Vikhrov, VV Vuaridel, B Whitten, CA Zhdanov, AA AF Allgower, CE Ball, J Barabash, LS Beauvais, PY Beddo, ME Borisov, N Boutefnouchet, A Bystricky, J Chamouard, PA Combet, M Demierre, P Fontaine, JM Ghazikhanian, V Grosnick, DP Hess, R Janout, Z Janout, ZF Kalinnikov, VA Kasprzyk, TE Kazarinov, YM Khachaturov, BA Kunne, R Lehar, F de Lesquen, A Lopiano, D de Mali, M Matafonov, VN Pisarev, IL Popov, AA Prokofiev, AN Rapin, D Sans, JL Spinka, HM Usov, YA Vikhrov, VV Vuaridel, B Whitten, CA Zhdanov, AA TI Angular dependence of the pp elastic scattering spin correlation parameter A(00nn) between 0.8 and 2.8 GeV: Results for 1.80-2.24 GeV SO PHYSICAL REVIEW C LA English DT Article ID ANALYZING POWER; SATURNE-II; POLARIZATION; PROTON; BEAM; OBSERVABLES; APPARATUS; ENERGIES; TARGET; REGION AB Measurements at 19 beam kinetic energies between 1795 and 2235 MeV are reported fur the pp elastic scattering spin correlation parameter A(00nn)=A(NN)=C-NN. The c.m. angular range is typically 60-100 degrees. The measurements were performed at Saturne II with a vertically polarized beam and target (transverse to the beam direction and scattering plane), a magnetic spectrometer and a recoil detector, both instrumented with multi-wire proportional chambers, and beam polarimeters. These results are compared to previous data from Saturne II and elsewhere. C1 Argonne Natl Lab, HEP Div, Argonne, IL 60439 USA. CEA Saclay, CEA DSM, F-91191 Gif Sur Yvette, France. IN2P3, CNRS, Natl Saturne Lab, F-91191 Gif Sur Yvette, France. CEA Saclay, DAPNIA, F-91191 Gif Sur Yvette, France. JINR, Lab Nucl Problems, RU-141980 Dubna, Moscow Region, Russia. Univ Calif Los Angeles, Dept Phys, Los Angeles, CA 90024 USA. Univ Geneva, DPNC, CH-1211 Geneva, Switzerland. Petersburg Nucl Phys Inst, RU-188350 Gatchina, Russia. RP Allgower, CE (reprint author), Indiana Univ, Cyclotron Facil, Bloomington, IN 47408 USA. NR 19 TC 14 Z9 16 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 DEC PY 2000 VL 62 IS 6 AR 064001 DI 10.1103/PhysRevC.62.064001 PG 11 WC Physics, Nuclear SC Physics GA 381CH UT WOS:000165744400008 ER PT J AU Appelbe, DE Martinez-Pinedo, G Austin, RAE Cameron, JA Chenkin, J Drake, TE Djerroud, B Flibotte, S Parker, DN Svensson, CE Waddington, JC Ward, D AF Appelbe, DE Martinez-Pinedo, G Austin, RAE Cameron, JA Chenkin, J Drake, TE Djerroud, B Flibotte, S Parker, DN Svensson, CE Waddington, JC Ward, D TI gamma-ray spectroscopy of Fe-56(26)30 SO PHYSICAL REVIEW C LA English DT Article ID STATES AB The 8 pi gamma -ray spectrometer has been used to resolve high-spin states in the nucleus Fe-56 following the reaction Ca-48(C-13,5n)Fe-56 at a beam energy of 65 MeV. This study has extended the known decay scheme of Fe-56 to J(pi)=(13(+))(h) over bar. The experimental decay scheme is compared with theoretical shell model calculations within the pf shell valence space. C1 McMaster Univ, Dept Phys & Astron, Hamilton, ON L8S 4M1, Canada. Aarhus Univ, Inst Fys & Astron, DK-8000 Aarhus C, Denmark. Univ Toronto, Dept Phys, Toronto, ON M5S 1A7, Canada. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Nucl Sci, Berkeley, CA 94720 USA. RP Appelbe, DE (reprint author), CLRC Daresbury, Keckwick Lane, Warrington WA4 4AD, Cheshire, England. RI Martinez-Pinedo, Gabriel/A-1915-2013 OI Martinez-Pinedo, Gabriel/0000-0002-3825-0131 NR 18 TC 5 Z9 5 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2813 J9 PHYS REV C JI Phys. Rev. C PD DEC PY 2000 VL 62 IS 6 AR 064314 DI 10.1103/PhysRevC.62.064314 PG 5 WC Physics, Nuclear SC Physics GA 381CH UT WOS:000165744400025 ER PT J AU Bleicher, M Greiner, W Stocker, H Xu, N AF Bleicher, M Greiner, W Stocker, H Xu, N TI Strangeness enhancement from strong color fields at relativistic heavy ion energies SO PHYSICAL REVIEW C LA English DT Article ID QUARK-GLUON PLASMA; NUCLEUS-NUCLEUS COLLISIONS; PB-PB COLLISIONS; MID-RAPIDITY; MODEL; MATTER; GEV/C; SEARCH; PARTON; PHASE AB In ultrarelativistic heavy ion collisions, early stage multiple scatterings may lead to an increase of the color electric field strength. Consequently, particle production-especially heavy quark (and diquark) production-is greatly enhanced according to the Schwinger mechanism. We test this idea via the ultrarelativistic quantum molecular dynamics model (UrQMD) for Au+Au collisions at the full RHIC energy (roots=200A GeV). Relative to p+p collisions, a factor of 60, 20, and 7 enhancement, respectively, for Omega (sss), Xi (ss), and Lambda, Sigma (s) is predicted for a model with increased color electric field strength. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Div Nucl Sci, Berkeley, CA 94720 USA. Goethe Univ Frankfurt, Inst Theoret Phys, D-60054 Frankfurt, Germany. RP Bleicher, M (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Div Nucl Sci, 1 Cyclotron Rd, Berkeley, CA 94720 USA. EM bleicher@nta2.lbl.gov RI Bleicher, Marcus/A-2758-2010; Stoecker, Horst/D-6173-2013 OI Stoecker, Horst/0000-0002-3282-3664 NR 41 TC 14 Z9 14 U1 0 U2 0 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2813 J9 PHYS REV C JI Phys. Rev. C PD DEC PY 2000 VL 62 IS 6 AR 061901 DI 10.1103/PhysRevC.62.061901 PG 4 WC Physics, Nuclear SC Physics GA 381CH UT WOS:000165744400004 ER PT J AU Bleicher, M Jeon, S Koch, V AF Bleicher, M Jeon, S Koch, V TI Event-by-event fluctuations of the charged particle ratio from nonequilibrium transport theory SO PHYSICAL REVIEW C LA English DT Article ID COLLISIONS; MODEL AB The event-by-event fluctuations of the ratio of positively to negatively charged hadrons an predicted within the UrQMD model. Corrections for finite acceptance and finite net charge are derived. These corrections are relevant to compare experimental data and transport model results to previous predictions. The calculated fluctuations at RHIC and SPS energies are shown to be compatible with a hadron gas, thus, deviating by a factor of 3 from the predictions for a thermalized quark-gluon plasma. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Div Nucl Sci, Berkeley, CA 94720 USA. RP Bleicher, M (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Div Nucl Sci, 1 Cyclotron Rd, Berkeley, CA 94720 USA. EM bleicher@nta2.lbl.gov RI Bleicher, Marcus/A-2758-2010 NR 13 TC 91 Z9 92 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 DEC PY 2000 VL 62 IS 6 AR 061902 DI 10.1103/PhysRevC.62.061902 PG 3 WC Physics, Nuclear SC Physics GA 381CH UT WOS:000165744400005 ER PT J AU Bravina, LV Zabrodin, EE Bass, SA Bleicher, M Brandstetter, M Soff, S Stocker, H Greiner, W AF Bravina, LV Zabrodin, EE Bass, SA Bleicher, M Brandstetter, M Soff, S Stocker, H Greiner, W TI Local equilibrium in heavy-ion collisions: Microscopic analysis of a central cell versus infinite matter SO PHYSICAL REVIEW C LA English DT Article ID NUCLEUS-NUCLEUS COLLISIONS; EQUATION-OF-STATE; QUANTUM MOLECULAR-DYNAMICS; THERMAL FREEZE-OUT; HADRONIC MATTER; CHEMICAL EQUILIBRATION; 200A GEV; SPS; MODEL; HOT AB We study the local equilibrium in the central V=125 fm(3) cell in heavy-ion collisions at energies from 10.7A GeV (AGS) to 160A GeV (SPS) calculated in the microscopic transport mo;del. In the present paper the hadron yields and energy spectra in the cell are compared with those of infinite nuclear matter, as calculated within the same model. The agreement between the spectra in the two systems is established for times t greater than or equal to 10 fm/c in the central cell. The cell results do not deviate noticeably from the infinite matter calculations with rising incident energy, in contrast to the apparent discrepancy with predictions of the statistical model (SM) of an ideal hadron gas. The entropy of this state is found to be very close to the maximum entropy, while hadron abundances and energy spectra differ significantly from those of the SM. C1 Univ Tubingen, Inst Theoret Phys, D-72076 Tubingen, Germany. Moscow MV Lomonosov State Univ, Inst Nucl Phys, RU-119899 Moscow, Russia. Michigan State Univ, Natl Superconducting Cyclotron Lab, E Lansing, MI 48823 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Nucl Sci, Berkeley, CA 94720 USA. Univ Frankfurt, Inst Theoret Phys, D-60325 Frankfurt, Germany. RP Bravina, LV (reprint author), Univ Tubingen, Inst Theoret Phys, Morgenstelle 14, D-72076 Tubingen, Germany. RI Bleicher, Marcus/A-2758-2010; Stoecker, Horst/D-6173-2013 OI Stoecker, Horst/0000-0002-3282-3664 NR 42 TC 13 Z9 13 U1 0 U2 1 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2813 J9 PHYS REV C JI Phys. Rev. C PD DEC PY 2000 VL 62 IS 6 AR 064906 DI 10.1103/PhysRevC.62.064906 PG 10 WC Physics, Nuclear SC Physics GA 381CH UT WOS:000165744400047 ER PT J AU Elliott, JB Albergo, S Bieser, F Brady, FP Caccia, Z Cebra, DA Chacon, AD Chance, JL Choi, Y Costa, S Gilkes, ML Hauger, JA Hirsch, AS Hjort, EL Insolia, A Justice, M Keane, D Kintner, JC Lindenstruth, V Lisa, MA Matis, HS McMahan, M McParland, C Muller, WFJ Olson, DL Partlan, MD Porile, NT Potenza, R Rai, G Rasmussen, J Ritter, HC Romanski, J Romero, JL Russo, GV Sann, H Scharenberg, RP Scott, A Shao, Y Srivastava, BK Symons, TJM Tincknell, M Tuve, C Wang, S Warren, PG Wieman, HH Wienold, T Wolf, K AF Elliott, JB Albergo, S Bieser, F Brady, FP Caccia, Z Cebra, DA Chacon, AD Chance, JL Choi, Y Costa, S Gilkes, ML Hauger, JA Hirsch, AS Hjort, EL Insolia, A Justice, M Keane, D Kintner, JC Lindenstruth, V Lisa, MA Matis, HS McMahan, M McParland, C Muller, WFJ Olson, DL Partlan, MD Porile, NT Potenza, R Rai, G Rasmussen, J Ritter, HC Romanski, J Romero, JL Russo, GV Sann, H Scharenberg, RP Scott, A Shao, Y Srivastava, BK Symons, TJM Tincknell, M Tuve, C Wang, S Warren, PG Wieman, HH Wienold, T Wolf, K TI Statistical signatures of critical behavior in small systems SO PHYSICAL REVIEW C LA English DT Review ID HEAVY-ION COLLISIONS; MULTIFRAGMENTATION CRITICAL EXPONENTS; PREEQUILIBRIUM PARTICLE-EMISSION; PROTON-NUCLEUS INTERACTIONS; SMALL PERCOLATION LATTICES; FISHERS DROPLET MODEL; 1A GEV GOLD; MONTE-CARLO; COULOMBIC CRITICALITY; FRAGMENT PRODUCTION AB The cluster distributions of three different systems are examined to search for signatures of a continuous phase transition. In a system known to possess such a phase transition, both sensitive and insensitive signatures are present; while in systems known not to possess such a phase transition, only insensitive signatures are present. It is shown that nuclear multifragmentation results in cluster distributions belonging to the former category, suggesting that the fragments are the result of a continuous phase transition. C1 Purdue Univ, W Lafayette, IN 47907 USA. Univ Catania, I-95129 Catania, Italy. Ist Nazl Fis Nucl, Sez Catania, I-95129 Catania, Italy. Univ Calif Davis, Davis, CA 95616 USA. GSI Darmstadt, D-64220 Darmstadt, Germany. Kent State Univ, Kent, OH 44242 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Nucl Sci, Berkeley, CA 94720 USA. Texas A&M Univ, College Stn, TX 77834 USA. RP Elliott, JB (reprint author), Purdue Univ, W Lafayette, IN 47907 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 102 TC 46 Z9 47 U1 0 U2 4 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 DEC PY 2000 VL 62 IS 6 AR 064603 DI 10.1103/PhysRevC.62.064603 PG 33 WC Physics, Nuclear SC Physics GA 381CH UT WOS:000165744400029 ER PT J AU Lazarev, YA Lobanov, YV Oganessian, YT Utyonkov, VK Abdullin, FS Polyakov, AN Rigol, J Shirokovsky, IV Tsyganov, YS Iliev, S Subbotin, VG Sukhov, AM Buklanov, GV Mezentsev, AN Subotic, K Moody, KJ Stoyer, NJ Wild, JF Lougheed, RW AF Lazarev, YA Lobanov, YV Oganessian, YT Utyonkov, VK Abdullin, FS Polyakov, AN Rigol, J Shirokovsky, IV Tsyganov, YS Iliev, S Subbotin, VG Sukhov, AM Buklanov, GV Mezentsev, AN Subotic, K Moody, KJ Stoyer, NJ Wild, JF Lougheed, RW TI Decay properties of No-257, (261)Rf, and (262)Rf SO PHYSICAL REVIEW C LA English DT Article ID SPONTANEOUS FISSION PROPERTIES; RUTHERFORDIUM; STABILITY; ISOTOPES; NUCLEI; N=162 AB In bombardments of Pu-244 targets with 114- and 120-MeV Ne-22 projectiles we detected 69 alpha-alpha correlations linking cw decays of (261)Rf and No-257. We observed one alpha peak with E-alpha= 8.30+/-0.06 MeV for (261)Rf and peaks with alpha -particle energies 8.07-8.40 MeV for No-257. The half-life of No-257 was measured to be 25 +/- 3. No correlations were found between alpha decays and subsequent spontaneous fission events, from which we calculated an upper limit of 1.5% for the fission branch of No-257 and estimated an upper limit of 3% for the alpha -decay branch of (262)Rf. The cross section of the Pu-244(Ne-22,5n)(261)Rf reaction was measured to be about 4 nb at both Ne-22 energies used. We also report on some results from Pu-242+Ne-22 and U-238+Mg-26 bombardments. C1 Joint Nucl Res Inst, RU-141980 Dubna, Russia. Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. NR 31 TC 28 Z9 28 U1 0 U2 1 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2813 J9 PHYS REV C JI Phys. Rev. C PD DEC PY 2000 VL 62 IS 6 AR 064307 DI 10.1103/PhysRevC.62.064307 PG 7 WC Physics, Nuclear SC Physics GA 381CH UT WOS:000165744400018 ER PT J AU Martin, A Garrett, PE Kadi, M Warr, N McEllistrem, MT Yates, SW AF Martin, A Garrett, PE Kadi, M Warr, N McEllistrem, MT Yates, SW TI gamma-ray decays in Th-232 and the K-pi=4(+) two-phonon gamma vibration SO PHYSICAL REVIEW C LA English DT Article ID DEFORMED-NUCLEI AB A recent Coulomb excitation study has called into question the 4(+) spin assignment of the 1414-keV level in Th-232, which had earlier been interpreted as a two-phonon gamma -vibrational excitation, and had suggested instead a 3(-) assignment. Data obtained in the present neutron scattering study of Th-232, inconsistent with the 3(-) suggestion and support an I-pi=4(+) assignment for the 1414-keV level, lending credence to the argument that it is a K-pi=4(+) band head. C1 Univ Kentucky, Coll Med, Lexington, KY 40506 USA. Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. RP Martin, A (reprint author), Univ Kentucky, Coll Med, Lexington, KY 40506 USA. NR 12 TC 6 Z9 7 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 DEC PY 2000 VL 62 IS 6 AR 067302 DI 10.1103/PhysRevC.62.067302 PG 3 WC Physics, Nuclear SC Physics GA 381CH UT WOS:000165744400056 ER PT J AU Randrup, J AF Randrup, J TI Quantum field treatment of disoriented-chiral-condensate dynamics SO PHYSICAL REVIEW C LA English DT Article ID PION-PRODUCTION; EVOLUTION; PLASMA; FORM; DCC AB A practical quantum-held treatment is developed for systems endowed with an effective mass function depending on both space and time and a schematic application illustrates the quantitative importance of quantum fluctuations in the dynamics of disoriented chiral condensates. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Div Nucl Sci, Berkeley, CA 94720 USA. RP Randrup, J (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Div Nucl Sci, 1 Cyclotron Rd, Berkeley, CA 94720 USA. NR 19 TC 9 Z9 9 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2813 J9 PHYS REV C JI Phys. Rev. C PD DEC PY 2000 VL 62 IS 6 AR 064905 PG 4 WC Physics, Nuclear SC Physics GA 381CH UT WOS:000165744400046 ER PT J AU Tjon, JA Wallace, SJ AF Tjon, JA Wallace, SJ TI Transition from hadronic to partonic interactions for a composite spin-1/2 model of a nucleon SO PHYSICAL REVIEW C LA English DT Article ID VIRTUAL COMPTON-SCATTERING; DIQUARK-QUARK MODEL; FORM-FACTORS; EXCLUSIVE PROCESSES; VECTOR INTERACTIONS; EXCHANGE CURRENTS; NJL MODEL; SCALAR; QCD; EQUATION AB A simple model of a composite nucleon is developed in which a fermion and a boson, representing quark and diquark constituents of the nucleon, form a bound state owing to a contact interaction. Photon and pion couplings to the quark provide vertex functions for the photon and pion interactions with the composite nucleon. By a suitable choice of cutoff parameters of the model, realistic electromagnetic form factors are obtained for the proton. When a pseudoscalar pion-quark coupling is used, the pion-nucleon coupling is predominantly pseudovector. A virtual photopion amplitude is considered in which there are two types of contributions: hadronic contributions where the photon and pion interactions have an intervening propagator of the nucleon or its excited states, and contactlike contributions where the photon and pion interactions occur within a single vertex. At large Q, the contactlike contributions are dominant. The model nucleon exhibits scaling behavior in deep-inelastic scattering and the normalization of the parton distribution provides a rough normalization of the contactlike contributions. Calculations for the virtual photopion amplitude are performed using kinematics appropriate to its occurrence as a meson-exchange current in electron-deuteron scattering. The results suggest that the contactlike terms can dominate the meson-exchange current for Q>1 GeV/c. There is a direct connection of the contactlike terms to the off-forward parton distributions of the model nucleon. C1 Univ Utrecht, Inst Theoret Phys, NL-3508 TA Utrecht, Netherlands. Univ Groningen, KVI, NL-9747 AA Groningen, Netherlands. Thomas Jefferson Natl Accelerator Facil, Newport News, VA 23606 USA. Univ Maryland, Dept Phys, College Pk, MD 20742 USA. Univ Maryland, Ctr Theoret Phys, College Pk, MD 20742 USA. RP Univ Utrecht, Inst Theoret Phys, NL-3508 TA Utrecht, Netherlands. NR 48 TC 1 Z9 1 U1 0 U2 0 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 2469-9985 EI 2469-9993 J9 PHYS REV C JI Phys. Rev. C PD DEC PY 2000 VL 62 IS 6 AR 065202 DI 10.1103/PhysRevC.62.065202 PG 17 WC Physics, Nuclear SC Physics GA 381CH UT WOS:000165744400049 ER PT J AU Ahmed, S Alam, MS Athar, SB Jian, L Ling, L Saleem, M Timm, S Wappler, F Anastassov, A Duboscq, JE Eckhart, E Gan, KK Gwon, C Hart, T Honscheid, K Hufnagel, D Kagan, H Kass, R Pedlar, TK Schwarthoff, H Thayer, JB von Toerne, E Zoeller, MM Richichi, SJ Severini, H Skubic, P Undrus, A Chen, S Fast, J Hinson, JW Lee, J Miller, DH Shibata, EI Shipsey, IPJ Pavlunin, V Cronin-Hennessy, D Lyon, AL Thorndike, EH Jessop, CP Marsiske, H Perl, ML Savinov, V Zhou, X Coan, TE Fadeyev, V Maravin, Y Narsky, I Stroynowski, R Ye, J Wlodek, T Artuso, M Ayad, R Boulahouache, C Bukin, K Dambasuren, E Karamov, S Majumder, G Moneti, GC Mountain, R Schuh, S Skwarnicki, T Stone, S Viehhauser, G Wang, JC Wolf, A Wu, J Kopp, S Mahmood, AH Csorna, SE Danko, I McLean, KW Marka, S Xu, Z Godang, R Kinoshita, K Lai, IC Schrenk, S Bonvicini, G Cinabro, D McGee, S Perera, LP Zhou, GJ Lipeles, E Pappas, SP Schmidtler, M Shapiro, A Sun, WM Weinstein, AJ Wurthwein, F Jaffe, DE Masek, G Paar, HP Potter, EM Prell, S Sharma, V Asner, DM Eppich, A Hill, TS Morrison, RJ Nelson, HN Richman, JD Witherell, MS Briere, RA Chen, GP Behrens, BH Ford, WT Gritsan, A Roy, J Smith, JG Alexander, JP Baker, R Bebek, C Berger, BE Berkelman, K Blanc, F Boisvert, V Cassel, DG Dickson, H Drell, PS Ecklund, KM Ehrlich, R Foland, AD Gaidarev, P Gibbons, L Gittelman, B Gray, SW Hartill, DL Heltsley, BK Hopman, PI Jones, CD Kreinick, DL Lohner, M Magerkurth, A Meyer, TO Mistry, NB Nordberg, E Patterson, JR Peterson, D Riley, D Thayer, JG Urner, D Valant-Spaight, B Warburton, A Avery, P Prescott, C Rubiera, AI Yelton, J Zheng, J Brandenburg, G Ershov, A Gao, YS Kim, DYJ Wilson, R Browder, TE Li, Y Rodriguez, JL Yamamoto, H Bergfeld, T Eisenstein, BI Ernst, J Gladding, GE Gollin, GD Hans, RM Johnson, E Karliner, I Marsh, MA Palmer, M Plager, C Sedlack, C Selen, M Thaler, JJ Williams, J Edwards, KW Janicek, R Patel, PM Sadoff, AJ Ammar, R Bean, A Besson, D Davis, R Kwak, N Zhao, X Anderson, S Frolov, VV Kubota, Y Lee, SJ Mahapatra, R O'Neill, JJ Poling, R Riehle, T Smith, A Stepaniak, CJ Urheim, J AF Ahmed, S Alam, MS Athar, SB Jian, L Ling, L Saleem, M Timm, S Wappler, F Anastassov, A Duboscq, JE Eckhart, E Gan, KK Gwon, C Hart, T Honscheid, K Hufnagel, D Kagan, H Kass, R Pedlar, TK Schwarthoff, H Thayer, JB von Toerne, E Zoeller, MM Richichi, SJ Severini, H Skubic, P Undrus, A Chen, S Fast, J Hinson, JW Lee, J Miller, DH Shibata, EI Shipsey, IPJ Pavlunin, V Cronin-Hennessy, D Lyon, AL Thorndike, EH Jessop, CP Marsiske, H Perl, ML Savinov, V Zhou, X Coan, TE Fadeyev, V Maravin, Y Narsky, I Stroynowski, R Ye, J Wlodek, T Artuso, M Ayad, R Boulahouache, C Bukin, K Dambasuren, E Karamov, S Majumder, G Moneti, GC Mountain, R Schuh, S Skwarnicki, T Stone, S Viehhauser, G Wang, JC Wolf, A Wu, J Kopp, S Mahmood, AH Csorna, SE Danko, I McLean, KW Marka, S Xu, Z Godang, R Kinoshita, K Lai, IC Schrenk, S Bonvicini, G Cinabro, D McGee, S Perera, LP Zhou, GJ Lipeles, E Pappas, SP Schmidtler, M Shapiro, A Sun, WM Weinstein, AJ Wurthwein, F Jaffe, DE Masek, G Paar, HP Potter, EM Prell, S Sharma, V Asner, DM Eppich, A Hill, TS Morrison, RJ Nelson, HN Richman, JD Witherell, MS Briere, RA Chen, GP Behrens, BH Ford, WT Gritsan, A Roy, J Smith, JG Alexander, JP Baker, R Bebek, C Berger, BE Berkelman, K Blanc, F Boisvert, V Cassel, DG Dickson, H Drell, PS Ecklund, KM Ehrlich, R Foland, AD Gaidarev, P Gibbons, L Gittelman, B Gray, SW Hartill, DL Heltsley, BK Hopman, PI Jones, CD Kreinick, DL Lohner, M Magerkurth, A Meyer, TO Mistry, NB Nordberg, E Patterson, JR Peterson, D Riley, D Thayer, JG Urner, D Valant-Spaight, B Warburton, A Avery, P Prescott, C Rubiera, AI Yelton, J Zheng, J Brandenburg, G Ershov, A Gao, YS Kim, DYJ Wilson, R Browder, TE Li, Y Rodriguez, JL Yamamoto, H Bergfeld, T Eisenstein, BI Ernst, J Gladding, GE Gollin, GD Hans, RM Johnson, E Karliner, I Marsh, MA Palmer, M Plager, C Sedlack, C Selen, M Thaler, JJ Williams, J Edwards, KW Janicek, R Patel, PM Sadoff, AJ Ammar, R Bean, A Besson, D Davis, R Kwak, N Zhao, X Anderson, S Frolov, VV Kubota, Y Lee, SJ Mahapatra, R O'Neill, JJ Poling, R Riehle, T Smith, A Stepaniak, CJ Urheim, J CA CLEO Collaboration TI Measurement of B ->(Ds(*)+D*(*)) branching fractions SO PHYSICAL REVIEW D LA English DT Article ID MESON DECAY CONSTANTS; HEAVY-QUARK SYMMETRY AB This article describes improved measurements by CLEO of the B-0-->D-s(+) D*(-) and B-0-->D-s(*+) D*(-) branching fractions, and first evidence for the decay B+-->D-s(()*()+) (D) over bar**(0), where (D) over bar**(0) represents the sum of the (D) over bar (1)(2420)(0), (D) over bar (2)*(2460)(0), and (D) over bar (1)(j = 1/2)(0) L = 1 charm meson states. Also reported is the first measurement of the D-s*(+) polarization in the decay B-0-->D-s*D+*(-). A partial reconstruction technique, employing only the fully reconstructed D-s(+) and slow pion pi (-)(s) from the D*(-)-->(D) over bar (0)pi (-)(s) decay, enhances sensitivity, The observed branching fractions are B(B-0-->Ds+D*(-)) = (1.10+/-0.18+/-0.10+/-0.28)%, B(B-0-->D-s*(+) D*(-)) =(1.82+/-0.37+/-0.24 +/-0.46)%, and B(B+-D-s(()*()+)(D) over bar**(0)) = (2.73+/-0.78+/-0.48+/-0.68)%, where the first error is statistical, the second systematic, and the third is the uncertainty in the D-s(+)-->phi pi (+) branching fraction. The measured D-s*(+) longitudinal polarization, Gamma (L)/Gamma = (50.6+/-13.9+/-3.6)%, is consistent with the factorization prediction of 54%. C1 SUNY Albany, Albany, NY 12222 USA. Ohio State Univ, Columbus, OH 43210 USA. Univ Oklahoma, Norman, OK 73019 USA. Purdue Univ, W Lafayette, IN 47907 USA. Univ Rochester, Rochester, NY 14627 USA. Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. So Methodist Univ, Dallas, TX 75275 USA. Syracuse Univ, Syracuse, NY 13244 USA. Univ Texas, Austin, TX 78712 USA. Univ Texas Pan Amer, Edinburg, TX 78539 USA. Vanderbilt Univ, Nashville, TN 37235 USA. Virginia Polytech Inst & State Univ, Blacksburg, VA 24061 USA. Wayne State Univ, Detroit, MI 48202 USA. CALTECH, Pasadena, CA 91125 USA. Univ Calif San Diego, La Jolla, CA 92093 USA. Univ Calif Santa Barbara, Santa Barbara, CA 93106 USA. Carnegie Mellon Univ, Pittsburgh, PA 15213 USA. Univ Colorado, Boulder, CO 80309 USA. Cornell Univ, Ithaca, NY 14853 USA. Univ Florida, Gainesville, FL 32611 USA. Harvard Univ, Cambridge, MA 02138 USA. Univ Hawaii Manoa, Honolulu, HI 96822 USA. Univ Illinois, Urbana, IL 61801 USA. Carleton Univ, Ottawa, ON K1S 5B6, Canada. Inst Particle Phys, Montreal, PQ, Canada. McGill Univ, Montreal, PQ H3A 2T8, Canada. Ithaca Coll, Ithaca, NY 14850 USA. Univ Kansas, Lawrence, KS 66045 USA. Univ Minnesota, Minneapolis, MN 55455 USA. Univ Cincinnati, Cincinnati, OH 45221 USA. MIT, Cambridge, MA 02139 USA. RP Ahmed, S (reprint author), SUNY Albany, Albany, NY 12222 USA. RI Warburton, Andreas/N-8028-2013; Briere, Roy/N-7819-2014 OI Warburton, Andreas/0000-0002-2298-7315; Briere, Roy/0000-0001-5229-1039 NR 24 TC 12 Z9 12 U1 1 U2 3 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2821 J9 PHYS REV D JI Phys. Rev. D PD DEC 1 PY 2000 VL 62 IS 11 AR 112003 DI 10.1103/PhysRevD.62.112003 PG 13 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 378YG UT WOS:000165612800007 ER PT J AU Alavi-Harati, A Albuquerque, IF Alexopoulos, T Arenton, M Arisaka, K Averitte, S Barker, AR Bellantoni, L Bellavance, A Belz, J Ben-David, R Bergman, DR Blucher, E Bock, GJ Bown, C Bright, S Cheu, E Childress, S Coleman, R Corcoran, MD Corti, G Cox, B Crisler, MB Erwin, AR Ford, R Glazov, A Golossanov, A Graham, G Graham, J Hagan, K Halkiadakis, E Hanagaki, K Hazumi, M Hidaka, S Hsiung, YB Jejer, V Jennings, J Jensen, DA Kessler, R Kobrak, HGE LaDue, J Lath, A Ledovskoy, A McBride, PL McManus, AP Mikelsons, P Monnier, E Nakaya, T Nelson, KS Nguyen, H O'Dell, V Pang, M Pordes, R Prasad, V Qiao, C Quinn, B Ramberg, EJ Ray, RE Roodman, A Sadamoto, M Schnetzer, S Senyo, K Shanahan, P Shawhan, PS Slater, W Solomey, N Somalwar, SV Stone, RL Suzuki, I Swallow, EC Swanson, RA Taegar, SA Tesarek, RJ Thomson, GB Toale, PA Tripathi, A Tschirhart, R Wah, YW Wang, J White, HB Whitmore, J Winstein, B Winston, R Yamanaka, T Zimmerman, ED AF Alavi-Harati, A Albuquerque, IF Alexopoulos, T Arenton, M Arisaka, K Averitte, S Barker, AR Bellantoni, L Bellavance, A Belz, J Ben-David, R Bergman, DR Blucher, E Bock, GJ Bown, C Bright, S Cheu, E Childress, S Coleman, R Corcoran, MD Corti, G Cox, B Crisler, MB Erwin, AR Ford, R Glazov, A Golossanov, A Graham, G Graham, J Hagan, K Halkiadakis, E Hanagaki, K Hazumi, M Hidaka, S Hsiung, YB Jejer, V Jennings, J Jensen, DA Kessler, R Kobrak, HGE LaDue, J Lath, A Ledovskoy, A McBride, PL McManus, AP Mikelsons, P Monnier, E Nakaya, T Nelson, KS Nguyen, H O'Dell, V Pang, M Pordes, R Prasad, V Qiao, C Quinn, B Ramberg, EJ Ray, RE Roodman, A Sadamoto, M Schnetzer, S Senyo, K Shanahan, P Shawhan, PS Slater, W Solomey, N Somalwar, SV Stone, RL Suzuki, I Swallow, EC Swanson, RA Taegar, SA Tesarek, RJ Thomson, GB Toale, PA Tripathi, A Tschirhart, R Wah, YW Wang, J White, HB Whitmore, J Winstein, B Winston, R Yamanaka, T Zimmerman, ED TI Evidence for the decay K-L ->mu(+)mu(-)gamma gamma SO PHYSICAL REVIEW D LA English DT Article ID BRANCHING RATIO; FORM-FACTOR; KL->E+E-GAMMA AB We have observed the decay K-L-->mu (+)mu (-)gamma gamma at the KTeV experiment at Fermilab. This decay presents a formidable background to the search for new physics in K-L-->pi (0)mu (+)mu (-). The 1997 data yielded a sample of 4 signal events, with an expected background of 0.155+/-0.081 events. The branching ratio is beta (K-L -->mu (+)mu (-)gamma gamma)= [10.4(-5.9)(+7.5) (stat)+/- 0.7 (syst)] x 10(-9) with m(gamma gamma)greater than or equal to1 MeV/c(2), consistent with a QED calculation which predicts (9.1+/-0.8) x 10(-9). C1 Rutgers State Univ, Piscataway, NJ 08855 USA. Univ Arizona, Tucson, AZ 85721 USA. Univ Calif Los Angeles, Los Angeles, CA 90095 USA. Univ Calif San Diego, La Jolla, CA 92093 USA. Univ Chicago, Enrico Fermi Inst, Chicago, IL 60637 USA. Univ Colorado, Boulder, CO 80309 USA. Elmhurst Coll, Elmhurst, IL 60126 USA. Fermi Natl Accelerator Lab, Batavia, IL 60510 USA. Osaka Univ, Osaka 560, Japan. Rice Univ, Houston, TX 77005 USA. Univ Virginia, Dept Phys, Charlottesville, VA 22901 USA. Univ Virginia, Inst Nucl & Particle Phys, Charlottesville, VA 22901 USA. Univ Wisconsin, Madison, WI 53706 USA. RP Lath, A (reprint author), Rutgers State Univ, Piscataway, NJ 08855 USA. RI Albuquerque, Ivone/H-4645-2012 OI Albuquerque, Ivone/0000-0001-7328-0136 NR 12 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 0556-2821 J9 PHYS REV D JI Phys. Rev. D PD DEC 1 PY 2000 VL 62 IS 11 AR 112001 DI 10.1103/PhysRevD.62.112001 PG 5 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 378YG UT WOS:000165612800005 ER PT J AU Bakulev, AP Radyushkin, AV Stefanis, NG AF Bakulev, AP Radyushkin, AV Stefanis, NG TI Form factors and QCD in spacelike and timelike regions SO PHYSICAL REVIEW D LA English DT Article ID QUANTUM-CHROMODYNAMIC CORRECTIONS; INTERMEDIATE MOMENTUM-TRANSFER; QUARK-HADRON DUALITY; PION WAVE-FUNCTION; PERTURBATIVE QCD; EXCLUSIVE PROCESSES; SUM-RULES; ASYMPTOTIC-BEHAVIOR; LEADING ORDER; TRANSVERSE-MOMENTUM AB We analyze the basic hard exclusive processes, the pi gamma* gamma -transition and the pion and nucleon electromagnetic form factors. and discuss the analytic continuation of QCD formulas from the spacelike q(2)<0 to the timelike region q(2)>0 of the relevant momentum transfers. We describe the construction of the timelike version of the coupling constant (s). We Show that due to the analytic continuation of the collinear logarithms, each eigenfunction of the evolution equation acquires a phase factor curd investigate the resulting interference effects which an shown to be very small. We find no sources for the K-factor-type enhancements in the perturbative QCD contribution to the hadronic form factors. To study the soft part of the pion electromagnetic form factor, we use a QCD sum rule inspired model and show that there are noncanceling Sudakov double logarithms which result in a K-factor-type enhancement in the timelike region. C1 Joint Inst Nucl Res, Bogolyubov Lab Theoret Phys, Dubna 141980, Russia. Old Dominion Univ, Dept Phys, Norfolk, VA 23529 USA. Jefferson Lab, Theory Grp, Newport News, VA 23606 USA. Ruhr Univ Bochum, Inst Theoret Phys 2, D-44780 Bochum, Germany. RP Joint Inst Nucl Res, Bogolyubov Lab Theoret Phys, Dubna 141980, Russia. NR 96 TC 54 Z9 54 U1 0 U2 0 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 2470-0010 EI 2470-0029 J9 PHYS REV D JI Phys. Rev. D PD DEC 1 PY 2000 VL 62 IS 11 AR 113001 DI 10.1103/PhysRevD.62.113001 PG 14 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 378YG UT WOS:000165612800008 ER PT J AU Bardeen, W Duncan, A Eichten, E Thacker, H AF Bardeen, W Duncan, A Eichten, E Thacker, H TI Anomalous chiral behavior in quenched lattice QCD SO PHYSICAL REVIEW D LA English DT Article ID PERTURBATION-THEORY; MASS; APPROXIMATION; U(1) AB A study of the chiral behavior of pseudoscalar masses and decay constants is carried out in quenched lattice QCD with Wilson fermions. Using the modified quenched approximation to cure the exceptional configuration problem, accurate results are obtained for pion masses as low as approximate to 200 MeV. The anomalous chiral log effect associated with quenched eta' loops is studied in both the relation between m(pi)(2) vs m(q) and in the light-mass behavior of the pseudoscalar and axial vector matrix elements. The size of these effects agrees quantitatively with a direct measurement of the eta' hairpin graph, as well as with a measurement of the topological susceptibility, thus providing several independent and quantitatively consistent determinations of the quenched chiral log parameter delta. For beta = 5.7 with clover-improved fermions (C-sw=1.57) all results are consistent with delta = 0.065 +/- 0.013. C1 Fermilab Natl Accelerator Lab, Batavia, IL 60510 USA. Univ Pittsburgh, Dept Phys & Astron, Pittsburgh, PA 15260 USA. Univ Virginia, Dept Phys, Charlottesville, VA 22901 USA. RP Fermilab Natl Accelerator Lab, POB 500, Batavia, IL 60510 USA. NR 21 TC 40 Z9 40 U1 0 U2 0 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 2470-0010 EI 2470-0029 J9 PHYS REV D JI Phys. Rev. D PD DEC 1 PY 2000 VL 62 IS 11 AR 114505 DI 10.1103/PhysRevD.62.114505 PG 16 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 378YG UT WOS:000165612800052 ER PT J AU Baur, U Rainwater, D AF Baur, U Rainwater, D TI Probing neutral gauge boson self-interactions in ZZ production at hadron colliders SO PHYSICAL REVIEW D LA English DT Article ID ANOMALOUS WW-GAMMA; ROOT-S=1.8 TEV; PAIR PRODUCTION; P(P)OVER-BAR COLLISIONS; WZ PRODUCTION; HELICITY AMPLITUDES; FERMILAB TEVATRON; PHOTON COUPLINGS; HIGGS DETECTION; W+W PRODUCTION AB A detailed analysis of ZZ production at the upgraded Fermilab Tevatron and the CERN Large Hadron Collider is presented for general ZZZ and ZZ gamma couplings. Deviations from the standard model gauge theory structure for each of these can be parametrized in terms of two form factors which are severely restricted by unitarity at high energy. Achievable limits on these couplings are shown to be a dramatic improvement over the limits currently obtained by e(+)e(-) experiments. C1 SUNY Buffalo, Dept Phys, Buffalo, NY 14260 USA. Fermi Natl Accelerator Lab, Theory Grp, Batavia, IL 60510 USA. RP Baur, U (reprint author), SUNY Buffalo, Dept Phys, Buffalo, NY 14260 USA. EM baur@ubhex.physics.buffalo.edu; dlrain@fnal.gov NR 73 TC 27 Z9 27 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2821 J9 PHYS REV D JI Phys. Rev. D PD DEC 1 PY 2000 VL 62 IS 11 AR 113011 DI 10.1103/PhysRevD.62.113011 PG 16 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 378YG UT WOS:000165612800018 ER PT J AU Brooks, T Dixon, L AF Brooks, T Dixon, L TI Recalculation of proton Compton scattering in perturbative QCD SO PHYSICAL REVIEW D LA English DT Article ID LARGE-MOMENTUM-TRANSFER; NUCLEON DISTRIBUTION AMPLITUDE; ELECTROMAGNETIC FORM-FACTORS; EXCLUSIVE PROCESSES; SUM-RULES; PARTON DISTRIBUTIONS; WAVE-FUNCTIONS; BARYONS; ELFE; REAL AB At very high energy and wide angles, Compton scattering on the proton (gammap-gammap) is described by perturbative QCD. The perturbative QCD calculation has been performed several times previously, at leading twist and at reading order in alpha (s), with mutually inconsistent results, even when the same light-cone distribution amplitudes have been employed. We have recalculated the helicity amplitudes for this process, using contour deformations to evaluate the singular integrals over the light-cone momentum fractions. We do not obtain complete agreement with any previous result. Our results are closest to those of the most recent previous computation, differing significantly for just one of the three independent helicity amplitudes, and only for backward scattering angles. We present results for the unpolarized cross section, and for three different polarization asymmetries. We compare the perturbative QCD predictions for these observables with those of the handbag and diquark models. In order to reduce uncertainties associated with alpha (s) and the three-quark wave function normalization, we have normalized the Compton cross section using the proton elastic form factor. The theoretical predictions for this ratio are about an order of magnitude below existing experimental data. C1 Stanford Univ, Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. RP Brooks, T (reprint author), Stanford Univ, Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. NR 51 TC 38 Z9 38 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2821 J9 PHYS REV D JI Phys. Rev. D PD DEC 1 PY 2000 VL 62 IS 11 AR 114021 DI 10.1103/PhysRevD.62.114021 PG 9 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 378YG UT WOS:000165612800040 ER PT J AU Campbell, J Ellis, RK AF Campbell, J Ellis, RK TI Radiative corrections to Zb(b)over-bar production SO PHYSICAL REVIEW D LA English DT Article ID ONE-LOOP AMPLITUDES; HADRON COLLIDERS; ANNIHILATION; BOSONS; HIGGS; QCD AB We report on QCD radiative corrections to the process p (p) over bar --> Zb (b) over bar in the approximation in which the b quark is considered massless. The implementation of this process in the general purpose Monte Carlo program MCFM is discussed in some detail. These results an used to investigate backgrounds to Higgs boson production in the ZH channel. We investigate the Higgs boson mass range (100 GeVs = 2 TeV. C1 Fermi Natl Accelerator Lab, Theory Dept, Batavia, IL 60510 USA. RP Campbell, J (reprint author), Fermi Natl Accelerator Lab, Theory Dept, POB 500, Batavia, IL 60510 USA. NR 20 TC 160 Z9 160 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 DEC 1 PY 2000 VL 62 IS 11 AR 114012 DI 10.1103/PhysRevD.62.114012 PG 12 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 378YG UT WOS:000165612800031 ER PT J AU Kiers, K Soni, A Wu, GH AF Kiers, K Soni, A Wu, GH TI Direct CP violation in radiative b decays in and beyond the standard model SO PHYSICAL REVIEW D LA English DT Article ID CHANGING NEUTRAL CURRENTS; HIGGS DOUBLET MODEL; 2-HIGGS-DOUBLET MODEL; B->X-S-GAMMA DECAYS; SCALAR INTERACTIONS; LEADING LOGARITHMS; MESON DECAY; TOP-QUARK; S-GAMMA; B->S-GAMMA AB We consider the partial rate asymmetry in the inclusive decay modes b-->s gamma and b-->d gamma, concentrating on non-standard models with new charged Higgs interactions. We find that the charged Higgs contribution to the asymmetry for b-->s gamma is small in such models due to a universal cancellation mechanism. The asymmetry is therefore difficult to distinguish experimentally from the standard model (SM) value, which is also small. The cancellation mechanism is found to be rendered inoperative in supersymmetry due to the presence of chargino loops. Unlike b-->s gamma, the rate asymmetry for b-->d gamma in Higgs models can be quite different from its SM value, generally ranging from -20% to +20%. Specific model calculations are performed for the three-Higgs-doublet model and the "top" two-Higgs-doublet model to serve as illustrations. We also offer some suggestions that may be helpful to experimentalists in the detection of the inclusive mode b-->d gamma. C1 Taylor Univ, Dept Phys, Upland, IN 46989 USA. Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. Univ Oregon, Inst Theoret Sci, Eugene, OR 97403 USA. RP Kiers, K (reprint author), Taylor Univ, Dept Phys, 236 W Reade Ave, Upland, IN 46989 USA. EM knkiers@tayloru.edu; soni@bnl.gov; wu@dirac.uoregon.edu NR 64 TC 50 Z9 51 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 DEC 1 PY 2000 VL 62 IS 11 AR 116004 DI 10.1103/PhysRevD.62.116004 PG 12 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 378YG UT WOS:000165612800066 ER PT J AU Mathur, N Dong, SJ Liu, KF Mankiewicz, L Mukhopadhyay, NC AF Mathur, N Dong, SJ Liu, KF Mankiewicz, L Mukhopadhyay, NC TI Quark orbital angular momentum from lattice QCD SO PHYSICAL REVIEW D LA English DT Article ID EXACTLY MASSLESS QUARKS; MUON-PROTON-SCATTERING; SPIN STRUCTURE; NUCLEON SPIN; PARTON MODEL; FORM-FACTOR AB We calculate the quark orbital angular momentum of the nucleon from the quark energy-momentum tensor form factors on the lattice with the quenched approximation. The disconnected insertion is estimated stochastically which employs the Z(2) noise with an unbiased subtraction. This reduced the error by a factor of 3-4 with negligible overhead. The total quark contribution to the proton spin is found to be 0.30 +/- 0.07. From this and the quark spin content we deduce the quark orbital angular momentum to be 0.17 +/- 0.06 which is similar to 34 % of the proton spin. We further predict that the gluon angular momentum is 0.20 +/- 0.07; i.e., similar to 40% of the proton spin is due to the glue. C1 Univ Kentucky, Dept Phys & Astron, Lexington, KY 40506 USA. Rensselaer Polytech Inst, Dept Phys Appl Phys & Astron, Troy, NY 12180 USA. Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. Copernicus Astron Ctr, PL-00716 Warsaw, Poland. Andrzej Soltan Inst Nucl Studies, Warsaw, Poland. RP Mathur, N (reprint author), Univ Kentucky, Dept Phys & Astron, Lexington, KY 40506 USA. RI Mankiewicz, Lech/G-4171-2011 NR 31 TC 54 Z9 54 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 DEC 1 PY 2000 VL 62 IS 11 AR 114504 DI 10.1103/PhysRevD.62.114504 PG 5 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 378YG UT WOS:000165612800051 ER PT J AU Melnikov, K Yelkhovsky, A AF Melnikov, K Yelkhovsky, A TI O(alpha 3 ln alpha) corrections to positronium decay rates SO PHYSICAL REVIEW D LA English DT Article AB We compute O(alpha (3)1n alpha) corrections to the decay rates of para- and orthopositronium into two and three photons, respectively. For this calculation we employ the nonrelativistic QED regularized dimensionally and we explain how in this framework the logarithms of the fine-structure constant can be extracted. C1 Stanford Univ, Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. Budker Inst Nucl Phys, Novosibirsk 630090, Russia. RP Melnikov, K (reprint author), Stanford Univ, Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. EM melnikov@slac.stanford.edu; yelkhovsky@inp.nsk.su NR 15 TC 32 Z9 32 U1 0 U2 1 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2821 J9 PHYS REV D JI Phys. Rev. D PD DEC 1 PY 2000 VL 62 IS 11 AR 116003 DI 10.1103/PhysRevD.62.116003 PG 8 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 378YG UT WOS:000165612800065 ER PT J AU Pisarski, RD AF Pisarski, RD TI Quark-gluon plasma as a condensate of Z(3) Wilson lines SO PHYSICAL REVIEW D LA English DT Article ID LATTICE GAUGE-THEORY; FINITE-TEMPERATURE QCD; DECONFINING PHASE-TRANSITION; QUANTUM CHROMODYNAMICS; DIMENSIONAL REDUCTION; LARGE-N; CONFINEMENT TRANSITIONS; MEAN FIELD; DEBYE MASS; MODEL AB Effective theories for the thermal Wilson line are constructed in an SU(N) gauge theory at nonzero temperature. I propose that the order of the deconfining phase transition for Z(N) Wilson lines is governed by the behavior of SU(N) Wilson lines. In a mean field theory, the free energy in the deconfined phase is controlled by the condensate for Z(N) Wilson lines. Numerical simulations on the lattice, and the mean held theory for Z(3) Wilson lines, suggest that about any finite temperature transition in QCD the dominant correlation length increases by a large, uniform factor, of order five. C1 Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. RP Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. EM pisarski@bnl.gov NR 63 TC 250 Z9 253 U1 0 U2 0 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 2470-0010 EI 2470-0029 J9 PHYS REV D JI Phys. Rev. D PD DEC 1 PY 2000 VL 62 IS 11 AR 111501 DI 10.1103/PhysRevD.62.111501 PG 5 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 378YG UT WOS:000165612800003 ER PT J AU Savkli, C Gross, F Tjon, J AF Savkli, C Gross, F Tjon, J TI Confinement and the analytic structure of the one-body propagator in scalar QED SO PHYSICAL REVIEW D LA English DT Article ID FEYNMAN-SCHWINGER REPRESENTATION; MODEL; MESONS; SINGULARITIES; EQUATIONS; COVARIANT; PHYSICS AB We investigate the behavior of the one-body propagator in SQED. The self-energy is calculated using three different methods: (i) the simple bubble summation, (ii) the Dyson-Schwinger equation, and (iii) the Feynman-Schwinger representation. The Feynman-Schwinger representation allows an exact analytical result. It is shown that, while the exact result produces a real mass pole for all couplings, the bubble sum and the Dyson-Schwinger approach in the rainbow approximation lead to complex mass poles beyond a certain critical coupling. The model exhibits confinement, yet the exact solution still has one-body propagators with real mass poles. C1 Coll William & Mary, Dept Phys, Williamsburg, VA 23187 USA. Jefferson Lab, Newport News, VA 23606 USA. Univ Utrecht, Inst Theoret Phys, NL-3508 TA Utrecht, Netherlands. RP Coll William & Mary, Dept Phys, Williamsburg, VA 23187 USA. NR 20 TC 4 Z9 4 U1 0 U2 0 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 2470-0010 EI 2470-0029 J9 PHYS REV D JI Phys. Rev. D PD DEC 1 PY 2000 VL 62 IS 11 AR 116006 DI 10.1103/PhysRevD.62.116006 PG 4 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 378YG UT WOS:000165612800068 ER PT J AU Silva, JP AF Silva, JP TI Use of the reciprocal basis in neutral meson mixing SO PHYSICAL REVIEW D LA English DT Article ID CP-VIOLATING PARAMETERS; B-DECAYS; INVARIANCE; REGENERATION AB In the presence of CP violation, the effective Hamiltonian matrix describing a neutral meson-antimeson system does not commute with its Hermitian conjugate. As a result, this matrix cannot be diagonalized by a unitary transformation and one needs to introduce a reciprocal basis. Although known, this fact is seldom discussed and almost never used. Hen, we use this concept to highlight a parametrization of the Hamiltonian matrix in terms of physical observables, and we show that using it reduces a number of long and tedious derivations into simple matrix multiplications. These results have a straightforward application for propagation in matter. We also comment on the (mathematical) relation with neutrino oscillations. C1 Stanford Univ, Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. Inst Super Engn Lisboa, P-1900 Lisbon, Portugal. RP Silva, JP (reprint author), Stanford Univ, Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. RI Silva, Joao/A-2896-2009; Physics Department, ISEL/F-6664-2010 OI Silva, Joao/0000-0002-6455-9618; NR 32 TC 11 Z9 11 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2821 J9 PHYS REV D JI Phys. Rev. D PD DEC 1 PY 2000 VL 62 IS 11 AR 116008 DI 10.1103/PhysRevD.62.116008 PG 12 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 378YG UT WOS:000165612800070 ER PT J AU Tandean, J Valencia, G AF Tandean, J Valencia, G TI Reanalysis of CP violation in K-L ->pi(+)pi(-)gamma SO PHYSICAL REVIEW D LA English DT Article ID NONLEPTONIC KAON DECAYS; BOTTOM CHARGED CURRENT; B->S-GAMMA DECAY; STANDARD MODEL; QCD CORRECTIONS; MESON DYNAMICS; B->SG DECAYS; NEUTRAL KAON; QUARK-MODEL; EPSILON'/EPSILON AB We present a reanalysis of direct CP violation in the decay K-L-->pi (+)pi (-)gamma. We point out an existing discrepancy between the theoretical and experimental definitions of epsilon (+-gamma)'. Adopting the experimental definition of epsilon (+-gamma)' we estimate that epsilon (+-gamma)'/epsilon could be as large as a few times 10(-4) both within the standard model and beyond. We discuss these estimates in detail and we also show how a judicious choice of E-gamma* cuts can increase the sensitivity of the observable epsilon (+-gamma)' to the underlying CP violation. C1 Iowa State Univ, Dept Phys & Astron, Ames, IA 50011 USA. Fermi Natl Accelerator Lab, Batavia, IL 60510 USA. RP Tandean, J (reprint author), Iowa State Univ, Dept Phys & Astron, Ames, IA 50011 USA. EM jtandean@iastate.edu; valencia@iastate.edu NR 72 TC 9 Z9 9 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2821 J9 PHYS REV D JI Phys. Rev. D PD DEC 1 PY 2000 VL 62 IS 11 AR 116007 DI 10.1103/PhysRevD.62.116007 PG 13 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 378YG UT WOS:000165612800069 ER PT J AU Seidler, GT Martinez, G Seeley, LH Kim, KH Behne, EA Zaranek, S Chapman, BD Heald, SM Brewe, DL AF Seidler, GT Martinez, G Seeley, LH Kim, KH Behne, EA Zaranek, S Chapman, BD Heald, SM Brewe, DL TI Granule-by-granule reconstruction of a sandpile from x-ray microtomography data SO PHYSICAL REVIEW E LA English DT Article ID SELF-ORGANIZED CRITICALITY; BOND-ORIENTATIONAL ORDER; CHOLESTERIC BLUE PHASE; METALLIC GLASSES; LIQUIDS; FRUSTRATION; CURVATURE; MICROSTRUCTURE; FLUCTUATIONS; CONVECTION AB Mesoscale disordered materials are ubiquitous in industry and in the environment. Any fundamental understanding of the transport and mechanical properties of such materials must follow from a,thorough understanding of their structure. However, in the overwhelming majority of cases, experimental characterization of such materials has been limited to first- and second-order structural correlation functions, i.e., the mean filling fraction and the structural autocorrelation function. We report here the successful combination of synchrotron x-ray microtomography and image processing to determine the full three-dimensional real-space structure of a model disordered material, a granular bed of relatively monodisperse glass spheres. Specifically, we determine the center location and the local connectivity of each granule. This complete knowledge of structure can be used to calculate otherwise inaccessible high-order correlation functions. We analyze nematic order parameters for contact bonds to characterize the geometric anisotropy or fabric induced by the sample boundary conditions. Away from the boundaries we find short-range bond orientational order exhibiting characteristics of the underlying polytetrahedral structure. C1 Univ Washington, Dept Phys, Seattle, WA 98195 USA. Adv Photon Source, PNC, CAT Sector 20, Argonne, IL 60439 USA. Pacific NW Natl Lab, Richland, WA 99352 USA. RP Univ Washington, Dept Phys, Seattle, WA 98195 USA. EM seidler@phys.washington.edu RI Seidler, Gerald/I-6974-2012 NR 72 TC 62 Z9 62 U1 0 U2 6 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 2470-0045 EI 2470-0053 J9 PHYS REV E JI Phys. Rev. E PD DEC PY 2000 VL 62 IS 6 BP 8175 EP 8181 DI 10.1103/PhysRevE.62.8175 PN B PG 7 WC Physics, Fluids & Plasmas; Physics, Mathematical SC Physics GA 383JN UT WOS:000165879500002 ER PT J AU Zhu, PW White, JW Epperson, JE AF Zhu, PW White, JW Epperson, JE TI Scaled structures in late stages of microphase separation of binary paraffin mixtures SO PHYSICAL REVIEW E LA English DT Article ID CAHN-HILLIARD EQUATION; PHASE-SEPARATION; SPINODAL DECOMPOSITION; COMPUTER-SIMULATION; TIME EVOLUTION; N-PARAFFINS; KINETICS; SYSTEMS; ALLOY AB Since the dynamic properties in paraffin mixtures are different from those in alloys and polymer blends, paraffin mixtures are believed to be another class of substances establishing the "universality" of the dynamical scaling behavior of phase separation. In this paper, the scaled structures of microphase separation in paraffin mixtures are described using a scaling function based on a two-phase model with kinetics based on the Cahn-Hilliard equation. It has been demonstrated that at the late stages of the microphase separation the scaling behavior in the paraffin mixtures agrees well with the universal features predicted by the scaling function. The scaled structures of microphase separation in paraffin mixtures can be directly calculated from the volume fraction of the minority phase without any adjustable parameter. C1 Australian Natl Univ, Res Sch Chem, Canberra, ACT 2601, Australia. Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. RP Zhu, PW (reprint author), Australian Natl Univ, Res Sch Chem, GPO Box 4, Canberra, ACT 2601, Australia. NR 30 TC 3 Z9 3 U1 0 U2 1 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1063-651X J9 PHYS REV E JI Phys. Rev. E PD DEC PY 2000 VL 62 IS 6 BP 8234 EP 8240 DI 10.1103/PhysRevE.62.8234 PN B PG 7 WC Physics, Fluids & Plasmas; Physics, Mathematical SC Physics GA 383JN UT WOS:000165879500007 ER PT J AU Filuk, AB Bailey, JE Cuneo, ME Lake, PW Nash, TJ Noack, DD Maron, Y AF Filuk, AB Bailey, JE Cuneo, ME Lake, PW Nash, TJ Noack, DD Maron, Y TI VUV absorption spectroscopy measurements of the role of fast neutral atoms in a high-power gap breakdown SO PHYSICAL REVIEW E LA English DT Article ID B ION DIODES; DENSITY MEASUREMENTS; PLASMA; PERFORMANCE; DIVERGENCE; GENERATION; EXPANSION; TW AB The maximum power achieved in a wide variety of high-power devices, including electron and ion diodes, z pinches, and microwave generators, is presently limited by anode-cathode gap breakdown. A frequently discussed hypothesis for this effect is ionization of fast neutral atoms injected throughout the anode-cathode gap during the power pulse. We describe a newly developed diagnostic tool that provides a direct test of this hypothesis. Time-resolved vacuum-ultraviolet absorption spectroscopy is used to directly probe fast neutral atoms with l-mm spatial resolution in the 10-mm anode-cathode gap of the SABRE 5 MV, I TW applied-B ion diode. Absorption spectra collected during Ar RF glow discharges and with CO2 gas fills confirm the reliability of the diagnostic technique. Throughout the 50-100 ns ion diode pulses no measurable neutral absorption was seen, setting upper limits of (0.12-1.5) X 10(14) cm(-3) for ground-state fast neutral atom densities of H, C, N, O, and F. The absence of molecular absorption bands also sets upper limits of (0.26-1.2) X 10(15) cm(-3) for common simple molecules. These limits are low enough to rule out ionization of fast neutral atoms as a breakdown mechanism. Breakdown due to ionization of molecules is also found to be unlikely. This technique can now be applied to quantify the role of neutral atoms in other high-power devices. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. Weizmann Inst Sci, IL-76100 Rehovot, Israel. RP Filuk, AB (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. NR 33 TC 2 Z9 2 U1 0 U2 4 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 DEC PY 2000 VL 62 IS 6 BP 8485 EP 8492 DI 10.1103/PhysRevE.62.8485 PN B PG 8 WC Physics, Fluids & Plasmas; Physics, Mathematical SC Physics GA 383JN UT WOS:000165879500036 ER PT J AU Gorham, PW Saltzberg, DP Schoessow, P Gai, W Power, JG Konecny, R Conde, ME AF Gorham, PW Saltzberg, DP Schoessow, P Gai, W Power, JG Konecny, R Conde, ME TI Radio-frequency measurements of coherent transition and Cherenkov radiation: Implications for high-energy neutrino detection SO PHYSICAL REVIEW E LA English DT Article ID FAR-INFRARED REGION; CERENKOV RADIATION; SYNCHROTRON RADIATION; ICE; SHOWERS; PULSES AB We report on measurements of (11-18)-cm wavelength radio emission from interactions of 15.2 MeV pulsed electron bunches at the Argonne Wakefield Accelerator. The electrons were observed both in a configuration where they produced primarily transition radiation from an aluminum foil, and in a configuration designed for the electrons to produce Cherenkov radiation in a silica sand target. Our aim was to emulate the large electron excess expected to develop during an electromagnetic cascade initiated by an ultrahigh-energy particle. Such charge asymmetries are predicted to produce strong coherent radio pulses, which are the basis for several experiments to detect high-energy neutrinos from the showers they induce in Antarctic ice and in the lunar regolith. We detected coherent emission which we attribute both to transition and possibly Cherenkov radiation at different levels depending on the experimental conditions. We discuss implications for experiments relying on radio emission for detection of electromagnetic cascades produced by ultrahigh-energy neutrinos. C1 Argonne Natl Lab, Argonne, IL 60493 USA. Univ Calif Los Angeles, Dept Phys & Astron, Los Angeles, CA 90095 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Gorham, PW (reprint author), Argonne Natl Lab, 9700 S Cass Ave, Argonne, IL 60493 USA. NR 34 TC 66 Z9 67 U1 0 U2 2 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1063-651X J9 PHYS REV E JI Phys. Rev. E PD DEC PY 2000 VL 62 IS 6 BP 8590 EP 8605 DI 10.1103/PhysRevE.62.8590 PN B PG 16 WC Physics, Fluids & Plasmas; Physics, Mathematical SC Physics GA 383JN UT WOS:000165879500045 ER PT J AU Van Meter, JR Kerman, AK Chen, P Hartemann, FV AF Van Meter, JR Kerman, AK Chen, P Hartemann, FV TI Radiative corrections in symmetrized classical electrodynamics SO PHYSICAL REVIEW E LA English DT Article ID COMPTON-SCATTERING AB The physics of radiation reaction for a point charge is discussed within the context of classical electrodynamics. The fundamental equations of classical electrodynamics are first symmetrized to include magnetic charges: a double four-potential formalism is introduced, in terms of which the field tensor and its dual are employed to symmetrize Maxwell's equations and the Lorentz force equation in covariant form. Within this framework, the symmetrized Dirac-Lorentz equation is derived, including radiation reaction (self-force) for a particle possessing both electric and magnetic charge. The connection with electromagnetic duality is outlined, and an in-depth discussion of nonlocal four-momentum conservation for the wave-particle system is given. C1 Univ Calif Lawrence Livermore Natl Lab, Inst Laser Sci & Applicat, Livermore, CA 94550 USA. Univ Calif Davis, Dept Phys, Davis, CA 95616 USA. MIT, Ctr Theoret Phys, Cambridge, MA 02139 USA. MIT, Dept Phys, Cambridge, MA 02139 USA. Stanford Univ, Stanford Linear Accelerator Ctr, Stanford, CA 94305 USA. RP Van Meter, JR (reprint author), Univ Calif Lawrence Livermore Natl Lab, Inst Laser Sci & Applicat, Livermore, CA 94550 USA. RI van meter, james/E-7893-2011 NR 44 TC 6 Z9 6 U1 0 U2 1 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1063-651X J9 PHYS REV E JI Phys. Rev. E PD DEC PY 2000 VL 62 IS 6 BP 8640 EP 8650 DI 10.1103/PhysRevE.62.8640 PN B PG 11 WC Physics, Fluids & Plasmas; Physics, Mathematical SC Physics GA 383JN UT WOS:000165879500051 ER PT J AU Shigemori, K Kodama, R Farley, DR Koase, T Estabrook, KG Remington, BA Ryutov, DD Ochi, Y Azechi, H Stone, J Turner, N AF Shigemori, K Kodama, R Farley, DR Koase, T Estabrook, KG Remington, BA Ryutov, DD Ochi, Y Azechi, H Stone, J Turner, N TI Experiments on radiative collapse in laser-produced plasmas relevant to astrophysical jets SO PHYSICAL REVIEW E LA English DT Article ID INSTABILITIES; TARGETS; STAR AB We report a laser experiment of astrophysical interest on radiative jet formation. Conically shaped targets are irradiated by intense laser Light. An ablated plasma flow collides at the axis of the cone targets, then propagates at high Mach number, forming a jetlike structure. We measure time-resolved x-ray self-emission images from the jets. The diameter of the jet increases with decreasing atomic number of the irradiated target, suggesting that the collimation is due to radiative cooling. Two-dimensional simulations reproduce essential features of the experimental results. C1 Osaka Univ, Inst Laser Engn, Suita, Osaka 5650871, Japan. Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. Univ Maryland, Dept Astron, College Pk, MD 20742 USA. RP Shigemori, K (reprint author), Osaka Univ, Inst Laser Engn, 2-2 Yamadaoka, Suita, Osaka 5650871, Japan. RI Azechi, Hiroshi/H-5876-2015; Shigemori, Keisuke/B-3262-2013; Kodama, Ryosuke/G-2627-2016 OI Shigemori, Keisuke/0000-0002-3978-8427; NR 21 TC 89 Z9 91 U1 3 U2 14 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 DEC PY 2000 VL 62 IS 6 BP 8838 EP 8841 DI 10.1103/PhysRevE.62.8838 PN B PG 4 WC Physics, Fluids & Plasmas; Physics, Mathematical SC Physics GA 383JN UT WOS:000165879500083 ER PT J AU Herzenberg, CL AF Herzenberg, CL TI Dark matter and the origin of mass: A simplified semiclassical approach SO PHYSICS ESSAYS LA English DT Article DE dark matter; dark energy; mass; gravitation; quantum mechanics; Planck length; space-time; physical vacuum; quantum fluctuations AB The pervasive presence in space of a flux of high-speed, electrically uncharged dark matter particles is examined here for potential consequences. Dark matter interactions with ordinary matter are considered, and a model of the dark matter flux is developed. in this model, the property of matter that we designate as mass is a measure of the interaction cross section of ordinary matter with the flux of dark matter. From this model emerge effects similar to certain quantum phenomena, and also a flux-mediated attractive inverse square force between particles of ordinary matter. The occurrence of effects resembling both quantum and gravitational phenomena in this model may enable a straightforward examination of the convergence of gravitational physics and quantum mechanics. C1 Argonne Natl Lab, Argonne, IL 60439 USA. RP Herzenberg, CL (reprint author), Argonne Natl Lab, 9700 S Cass Ave, Argonne, IL 60439 USA. NR 13 TC 0 Z9 0 U1 0 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 DEC PY 2000 VL 13 IS 4 BP 604 EP 612 PG 9 WC Physics, Multidisciplinary SC Physics GA 498FK UT WOS:000172499000014 ER PT J AU Ryutov, DD AF Ryutov, DD TI Destabilizing effect of thermal conductivity on the Rayleigh-Taylor instability in a plasma SO PHYSICS OF PLASMAS LA English DT Article ID INERTIAL CONFINEMENT FUSION; VERTICAL SLOT CONVECTION; SUPERNOVA HYDRODYNAMICS; STABILITY ANALYSIS; SIMULATION; MODEL; LASER AB It is shown that the Rayleigh-Taylor instability in a compressible medium is not necessarily stabilized by thermal conductivity. It is pointed out that one can use the destabilization effect for in situ measurements of thermal conductivity in high-energy-density experiments. The other ii consequence is generation of small-scale turbulence in supernovae, giving rise to significant turbulent viscosity. [S1070-664X(00)03812-X]. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. RP Ryutov, DD (reprint author), Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. NR 22 TC 12 Z9 12 U1 1 U2 4 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 1070-664X J9 PHYS PLASMAS JI Phys. Plasmas PD DEC PY 2000 VL 7 IS 12 BP 4797 EP 4800 DI 10.1063/1.1321316 PG 4 WC Physics, Fluids & Plasmas SC Physics GA 378YH UT WOS:000165612900001 ER PT J AU Brizard, AJ AF Brizard, AJ TI Variational principle for nonlinear gyrokinetic Vlasov-Maxwell equations SO PHYSICS OF PLASMAS LA English DT Article ID PLASMA AB A new variational principle for the nonlinear gyrokinetic Vlasov-Maxwell equations is presented. This Eulerian variational principle uses constrained variations for the gyrocenter Vlasov distribution in eight-dimensional extended phase space and turns out to be simpler than the Lagrangian variational principle recently presented by ii. Sugama [Phys. Plasmas 7, 466 (2000)]. A local energy conservation law is then derived explicitly by the Noether method. In future work, this new variational principle will be used to derive self-consistent, nonlinear, low-frequency Vlasov-Maxwell bounce-gyrokinetic equations, in which the fast gyromotion and bounce-motion time scales have been eliminated. (C) 2000 American Institute of Physics. [S1070-664X(00)03412-7]. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Brizard, AJ (reprint author), St Michaels Coll, Box 254,1 Winooski Pk, Colchester, VT 05439 USA. OI Brizard, Alain/0000-0002-0192-6273 NR 21 TC 59 Z9 59 U1 0 U2 6 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 1070-664X J9 PHYS PLASMAS JI Phys. Plasmas PD DEC PY 2000 VL 7 IS 12 BP 4816 EP 4822 DI 10.1063/1.1322063 PG 7 WC Physics, Fluids & Plasmas SC Physics GA 378YH UT WOS:000165612900005 ER PT J AU Rewoldt, G Ku, LP Tang, WM Sugama, H Nakajima, N Watanabe, KY Murakami, S Yamada, H Cooper, WA AF Rewoldt, G Ku, LP Tang, WM Sugama, H Nakajima, N Watanabe, KY Murakami, S Yamada, H Cooper, WA TI Drift mode calculations for the Large Helical Device SO PHYSICS OF PLASMAS LA English DT Article ID EQUILIBRIA; STABILITY AB A fully kinetic assessment of the stability properties of toroidal drift modes has been obtained for a case for the Large Helical Device [A. Iiyoshi et al., Nucl. Fusion 39, 1245 (1999)]. This calculation retains the important effects in the linearized gyrokinetic equation, using the lowest-order "ballooning representation" for high toroidal mode number instabilities in the electrostatic limit. Results for toroidal drift waves destabilized by trapped particle dynamics and ion temperature gradients are presented, using three-dimensional magnetohydrodynamic equilibria reconstructed from experimental measurements. The effects of helically trapped particles and helical curvature are investigated. (C) 2000 American Institute of Physics. [S1070-664X(00)00512-7]. C1 Princeton Univ, Plasma Phys Lab, Princeton, NJ 08543 USA. Natl Inst Fus Sci, Toki 5095292, Japan. Ecole Polytech Fed Lausanne, Ctr Rech Phys Plasmas, PPB Ecublens, CH-1015 Lausanne, Switzerland. RP Rewoldt, G (reprint author), Princeton Univ, Plasma Phys Lab, POB 451, Princeton, NJ 08543 USA. RI Murakami, Sadayoshi/A-2191-2016; OI Murakami, Sadayoshi/0000-0002-2526-7137; Hideo, Sugama/0000-0001-5444-1758 NR 18 TC 14 Z9 14 U1 0 U2 1 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 1070-664X J9 PHYS PLASMAS JI Phys. Plasmas PD DEC PY 2000 VL 7 IS 12 BP 4942 EP 4947 DI 10.1063/1.1317521 PG 6 WC Physics, Fluids & Plasmas SC Physics GA 378YH UT WOS:000165612900019 ER PT J AU Mynick, HE Pomphrey, N AF Mynick, HE Pomphrey, N TI Control-matrix approach to stellarator design and control SO PHYSICS OF PLASMAS LA English DT Article ID OPTIMIZATION AB The full space Z={Z(j=1,...,Nz)} of independent variables defining a stellarator configuration is large. To, find attractive design points in this space, or to understand operational flexibility about a given design point, one needs insight into the topography in Z-space of the physics figures of merit P-i which characterize the machine performance, and means of determining those directions in Z-space which give one independent control over the P-i, as well as those which affect none of them, and so are available for design flexibility. The control matrix (CM) approach described here provides a mathematical means of obtaining these. In this work, the CM approach is described and used in studying some candidate Quasi-Axisymmetric (QA) stellarator configurations the National Compact Stellarator Experiment design group has been considering. In the process of the analysis, a first exploration of the topography of the configuration space in the vicinity of these candidate systems has been performed, whose character is discussed. (C) 2000 American Institute of Physics. [S1070-664X(00)00912-5]. C1 Princeton Univ, Plasma Phys Lab, Princeton, NJ 08543 USA. RP Mynick, HE (reprint author), Princeton Univ, Plasma Phys Lab, POB 451, Princeton, NJ 08543 USA. RI pomphrey, neil/G-4405-2010 NR 14 TC 4 Z9 4 U1 0 U2 1 PU AMER INST PHYSICS PI MELVILLE PA 1305 WALT WHITMAN RD, STE 300, MELVILLE, NY 11747-4501 USA SN 1070-664X EI 1089-7674 J9 PHYS PLASMAS JI Phys. Plasmas PD DEC PY 2000 VL 7 IS 12 BP 4960 EP 4971 DI 10.1063/1.1318354 PG 12 WC Physics, Fluids & Plasmas SC Physics GA 378YH UT WOS:000165612900021 ER PT J AU Belova, EV Jardin, SC Ji, H Yamada, M Kulsrud, R AF Belova, EV Jardin, SC Ji, H Yamada, M Kulsrud, R TI Numerical study of tilt stability of prolate field-reversed configurations SO PHYSICS OF PLASMAS LA English DT Article ID HYBRID SIMULATIONS; STABILIZATION; INSTABILITY; MODE; PLASMAS; RINGS AB Global stability of the field-reversed configuration (FRC) has been investigated numerically using both three-dimensional magnetohydrodynamic and hybrid (fluid electron and deltaf particle ion) simulations. The stabilizing effects of velocity shear and finite ion Larmor radius (FLR) on the n = 1 internal tilt mode in the prolate FRCs have been studied. Sheared rotation is found to reduce the growth rate, however a large rotation rate with Mach number of M greater than or similar to 1 is required in order for significant reduction in the instability growth rate to occur. Kinetic effects associated with large thermal ion orbits have been studied for different kinetic equilibria. The simulations show that there is a reduction in the tilt mode growth rate due to FLR effects, but complete linear stability has not been found, even when the thermal ion gyroradius is comparable to the distance between the field null and the separatrix. The instability existing beyond the FLR theory threshold could be due to the resonant interaction of the wave with ions whose Doppler shifted frequency matches the betatron frequency. (C) 2000 American Institute of Physics. [S1070-664X(00)01612-8]. C1 Princeton Plasma Phys Lab, Princeton, NJ 08543 USA. RP Belova, EV (reprint author), Princeton Plasma Phys Lab, POB 451, Princeton, NJ 08543 USA. RI Jardin, Stephen/E-9392-2010; Yamada, Masaaki/D-7824-2015 OI Yamada, Masaaki/0000-0003-4996-1649 NR 30 TC 52 Z9 52 U1 1 U2 4 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 1070-664X J9 PHYS PLASMAS JI Phys. Plasmas PD DEC PY 2000 VL 7 IS 12 BP 4996 EP 5006 DI 10.1063/1.1318929 PG 11 WC Physics, Fluids & Plasmas SC Physics GA 378YH UT WOS:000165612900024 ER PT J AU Leboeuf, JN Lynch, VE Carreras, BA Alvarez, JD Garcia, L AF Leboeuf, JN Lynch, VE Carreras, BA Alvarez, JD Garcia, L TI Full torus Landau fluid calculations of ion temperature gradient-driven turbulence in cylindrical geometry SO PHYSICS OF PLASMAS LA English DT Article ID GLOBAL NUMERICAL SIMULATIONS; GYROKINETIC SIMULATION; THERMAL TRANSPORT; TOKAMAKS AB Results of Landau fluid calculations of ion temperature gradient-driven turbulence in cylindrical geometry but which covet the whole plasma cross section ale reported. A simple gyrofluid model is used which evolves in time equations For the ion density or vorticity, the parallel ion velocity, and the ion temperature where Landau damping is included through a linear closure relation. Adiabatic electrons and the electrostatic approximation are assumed to hold. Linear calculations indicate that the growth rates are significantly reduced in the presence of Landau damping. Nonlinear single helicity calculations serve to illustrate the spatial localization of the turbulence in the presence of Landau damping. Finally nonlinear multiple helicity calculations performed with three different values for the ratio of the central ion Larmor radius to the plasma minor radius denoted by rho (*) exhibit a definite linear scaling of all the fluctuation characteristics, such as levels, scale sizes, quasilinear profile modifcations, self-generated poloidal flows, and heat diffusivities, with rho (*) (C) 2000 American Institute of Physics. [S1070-664X(01)00301-9]. C1 Univ Calif Los Angeles, Los Angeles, CA 90095 USA. Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. Univ Carlos III Madrid, Madrid 28911, Spain. RP Leboeuf, JN (reprint author), Univ Calif Los Angeles, Los Angeles, CA 90095 USA. RI Lynch, Vickie/J-4647-2012; Garcia, Luis/A-5344-2015; ALVAREZ, DIEGO/F-9157-2016 OI Lynch, Vickie/0000-0002-5836-7636; Garcia, Luis/0000-0002-0492-7466; ALVAREZ, DIEGO/0000-0002-3712-2461 NR 17 TC 10 Z9 10 U1 1 U2 1 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 1070-664X J9 PHYS PLASMAS JI Phys. Plasmas PD DEC PY 2000 VL 7 IS 12 BP 5013 EP 5022 DI 10.1063/1.1323757 PG 10 WC Physics, Fluids & Plasmas SC Physics GA 378YH UT WOS:000165612900026 ER PT J AU Budny, RV Ernst, DR Hahm, TS McCune, DC Christiansen, JP Cordey, JG Gowers, CG Guenther, K Hawkes, N Jarvis, ON Stubberfield, PM Zastrow, KD Horton, LD Saibene, G Sartori, R Thomsen, K von Hellermann, MG AF Budny, RV Ernst, DR Hahm, TS McCune, DC Christiansen, JP Cordey, JG Gowers, CG Guenther, K Hawkes, N Jarvis, ON Stubberfield, PM Zastrow, KD Horton, LD Saibene, G Sartori, R Thomsen, K von Hellermann, MG TI Local transport in joint European Tokamak edge-localized, high-confinement mode plasmas with H, D, DT, and T isotopes SO PHYSICS OF PLASMAS LA English DT Article ID DEUTERIUM-TRITIUM EXPERIMENTS; HIGH FUSION POWER; TURBULENT TRANSPORT; ASPECT RATIO; JET; SIMULATIONS; FLOW; COLLISIONALITY; OPERATION; REACTOR AB The edge-localized, high-confinement mode regime is of interest for future Tokamak reactors since high performance has been sustained for long durations. Experiments in the Joint European Tokamak [M. Keilhacker et al., Nuclear Fusion 39, 209 (1999)] have studied this regime using scans with the toroidal field and plasma current varied together in H, D, DT, and T isotopes. The local energy transport in more than fifty of these plasmas is analyzed, and empirical scaling relations are derived for energy transport coefficients during quasi-steady state conditions using dimensionless parameters. Neither the Bohm nor gyro-Bohm expressions give the shapes of the profiles. The scalings with beta and nu (*) are in qualitative agreement with Ion Temperature Gradient theory. (C) 2000 American Institute of Physics. [S1070-664X(00)02912-8]. C1 Princeton Univ, Princeton Plasma Phys Lab, Princeton, NJ 08543 USA. UKAEA Euratom Fus Assoc, Culham Lab, Abingdon OX14 3DB, Oxon, England. Max Planck Inst Plasmaphys, D-85748 Garching, Germany. EFDA, Close Support Unit, Garching, Germany. Max Planck Inst Plasmaphys, D-85748 Garching, Germany. EURATOM, FOM, Inst Plasma Phys Rijnhuizen, NL-3430 BE Nieuwegein, Netherlands. RP Budny, RV (reprint author), Princeton Univ, Princeton Plasma Phys Lab, POB 451, Princeton, NJ 08543 USA. RI Ernst, Darin/A-1487-2010 OI Ernst, Darin/0000-0002-9577-2809 NR 38 TC 30 Z9 31 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 1070-664X J9 PHYS PLASMAS JI Phys. Plasmas PD DEC PY 2000 VL 7 IS 12 BP 5038 EP 5050 DI 10.1063/1.1320466 PG 13 WC Physics, Fluids & Plasmas SC Physics GA 378YH UT WOS:000165612900029 ER PT J AU Fredrickson, ED Austin, ME Groebner, R Manickam, J Rice, B Schmidt, G Snider, R AF Fredrickson, ED Austin, ME Groebner, R Manickam, J Rice, B Schmidt, G Snider, R TI Heat pulse propagation studies on DIII-D and the Tokamak Fusion Test Reactor SO PHYSICS OF PLASMAS LA English DT Article ID X-RAY TOMOGRAPHY; SAWTOOTH OSCILLATIONS; TFTR TOKAMAK; DISRUPTIONS; TRANSPORT; PLASMAS; STABILIZATION; RECONNECTION; CRASHES AB Sawtooth phenomena have been studied on DIII-D and the Tokamak Fusion Test Reactor (TFTR) [D. Meade and the TFTR Group, in Proceedings of the International Conference on Plasma Physics and Controlled Nuclear Fusion, Washington, DC, 1990 (International Atomic Energy Agency, Vienna, 1991), Vol. 1, pp. 9-24]. In the experiments the sawtooth characteristics were studied with fast electron temperature (ECE) and soft x-ray diagnostics. For the first time, measurements of a strong ballistic electron heat pulse were made in a shaped tokamak (DIII-D) [J. Luxon and DIII-D Group, in Proceedings of the 11th International Conference on Plasma Physics and Controlled Nuclear Fusion Research, Kyoto (International Atomic Energy Agency, Vienna, 1987), Vol. 1, p. 159] and the "ballistic effect" was stronger than was previously reported on TFTR. Evidence is presented in this paper that the ballistic effect is related to the fast growth phase of the sawtooth precursor. Fast, 2 ms interval, measurements on DIII-D were made of the ion temperature evolution following sawteeth and partial sawteeth to document the ion heat pulse characteristics. It is found that the ion heat pulse does not exhibit the very fast, "ballistic" behavior seen for the electrons. Further, for the first time it is shown that the electron heat pulses from partial sawtooth crashes (on DIII-D and TFTR) are seen to propagate at speeds close to those expected from the power balance calculations of the thermal diffusivities whereas heat pulses from fishbones propagate at rates more consistent with sawtooth induced heat pulses. These results suggest that the fast propagation of sawtooth-induced heat pulses is not a feature of nonlinear transport models, but that magnetohydrodynamic events can have a strong effect on electron thermal transport. (C) 2000 American Institute of Physics. [S1070-664X(00)02012-7]. C1 Princeton Plasma Phys Lab, Princeton, NJ 08543 USA. Univ Texas, Austin, TX 78712 USA. Gen Atom Co, San Diego, CA 92186 USA. Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Fredrickson, ED (reprint author), Princeton Plasma Phys Lab, POB 451, Princeton, NJ 08543 USA. NR 33 TC 13 Z9 13 U1 0 U2 2 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 1070-664X J9 PHYS PLASMAS JI Phys. Plasmas PD DEC PY 2000 VL 7 IS 12 BP 5051 EP 5063 DI 10.1063/1.1319335 PG 13 WC Physics, Fluids & Plasmas SC Physics GA 378YH UT WOS:000165612900030 ER PT J AU Kanzleiter, RJ Stotler, DP Karney, CFF Steiner, D AF Kanzleiter, RJ Stotler, DP Karney, CFF Steiner, D TI Improved elastic collision modeling in DEGAS 2 for low-temperature plasmas SO PHYSICS OF PLASMAS LA English DT Article ID ALCATOR C-MOD; SLOW COLLISIONS; DIVERTOR; TRANSPORT; SCATTERING; DETACHMENT; SIMULATION; EDGE AB Recent emphasis on low-temperature divertor operations has focused attention on proper treatment of neutral-elastic collisions in low-temperature environments. For like species collisions, as in D+ + D, quantum mechanical indistinguishability precludes differentiation of small-angle elastic scattering from resonant charge exchange for collision energies <2 eV. The current work improves the low-temperature simulation capabilities of the DEGAS 2 Monte Carlo neutral transport code [D. P. Stotler and C. F. F. Karney, Contrib. Plasma Phys. 34, 392-397 (1994)] by employing a set of quantum mechanical collision cross sections produced by Oak Ridge National Laboratory to provide a comprehensive treatment of ion-neutral elastic collisions. Ion-molecular collisions in the form of D+ + D-2 are included for the first time. An integration technique is utilized that reduces the total collision cross section while keeping the other transport cross sections invariant. The inclusion of ion-molecular elastic collisions results in significant increases in energy exchange between background ions and neutral test species. (C) 2000 American Institute of Physics. [S1070-664X(00)03712-5]. C1 Rensselaer Polytech Inst, Dept Environm & Energy Engn, Troy, NY 12180 USA. Univ Calif Los Alamos Natl Lab, X Div, Los Alamos, NM 87545 USA. Princeton Plasma Phys Lab, Princeton, NJ 08543 USA. RP Kanzleiter, RJ (reprint author), Rensselaer Polytech Inst, Dept Environm & Energy Engn, 110 8th St, Troy, NY 12180 USA. RI Karney, Charles/C-1371-2013; Stotler, Daren/J-9494-2015 OI Karney, Charles/0000-0002-5006-5836; Stotler, Daren/0000-0001-5521-8718 NR 28 TC 10 Z9 10 U1 1 U2 3 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 1070-664X J9 PHYS PLASMAS JI Phys. Plasmas PD DEC PY 2000 VL 7 IS 12 BP 5064 EP 5069 DI 10.1063/1.1321018 PG 6 WC Physics, Fluids & Plasmas SC Physics GA 378YH UT WOS:000165612900031 ER PT J AU In, Y Ramos, JJ Hastie, RJ Catto, PJ Hubbard, AE Hutchinson, IH Marmar, E Porkolab, M Snipes, J Wolfe, S Taylor, G Bondeson, A AF In, Y Ramos, JJ Hastie, RJ Catto, PJ Hubbard, AE Hutchinson, IH Marmar, E Porkolab, M Snipes, J Wolfe, S Taylor, G Bondeson, A TI Identification of Mercier instabilities in Alcator C-Mod tokamak SO PHYSICS OF PLASMAS LA English DT Article ID INTERNAL KINK MODES; TOROIDAL ROTATION; ASPECT RATIO; STABILITY; PLASMAS; CRITERION; RECONNECTION AB During current ramp-up discharges, highly localized magnetohydrodynamic (MHD) fluctuations were observed on the electron cyclotron emission diagnostics of Alcator C-Mod tokamak [I. H. Hutchinson ci al., Phys. Plasmas 1, 1511 (1994)]. The electron temperature profile was hollow, while the density profile was weakly decreasing. Assuming that the equilibration time was short enough to quickly thermalize ions the pressure profile was also found to be hollow. Using this pressure profile as an additional constraint to the EFIT program, an equilibrium with reversed shear was constructed having a q(0)much greater than1. The localized MHD activity was observed near the inner q =5 rational surface in this reconstructed equilibrium, where the Mercier criterion for ideal MHD stability was violated because of the reversed pressure gradient (dpldr>0), q>1 and moderate shear. When kinetic effects were added, the ideal Mercier mode was finite ion Larmor radius stabilized. However, ion Landau damping was found to be strong enough to drive a kinetic Mercier instability. (C) 2000 American Institute of Physics. [S1070-664X(01)00401-3]. C1 MIT, Plasma Sci & Fus Ctr, Cambridge, MA 02139 USA. Princeton Plasma Phys Lab, Princeton, NJ 08543 USA. Chalmers Univ Technol, S-41296 Gothenburg, Sweden. RP In, Y (reprint author), MIT, Plasma Sci & Fus Ctr, 77 Massachusetts Ave, Cambridge, MA 02139 USA. RI Hutchinson, Ian/D-1136-2009 OI Hutchinson, Ian/0000-0003-4276-6576 NR 28 TC 2 Z9 2 U1 1 U2 2 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 1070-664X J9 PHYS PLASMAS JI Phys. Plasmas PD DEC PY 2000 VL 7 IS 12 BP 5087 EP 5095 DI 10.1063/1.1323758 PG 9 WC Physics, Fluids & Plasmas SC Physics GA 378YH UT WOS:000165612900034 ER PT J AU Turano, EJ McKinstrie, CJ AF Turano, EJ McKinstrie, CJ TI Oblique stimulated Raman scattering of a short laser pulse in a plasma channel SO PHYSICS OF PLASMAS LA English DT Article ID PARAMETRIC-INSTABILITIES DRIVEN; BRILLOUIN-SCATTERING; SPATIOTEMPORAL EVOLUTION; 2-DIMENSIONAL ANALYSIS; TENUOUS PLASMAS; TIME BEHAVIOR; BACKSCATTER; SPACE AB The spatiotemporal evolution of parametric instabilities such as stimulated Raman scattering is studied analytically in time and two spatial dimensions. Initial and boundary conditions are chosen to represent the entrance, propagation, and exit of a laser pulse of finite extent as it progresses through a homogeneous collisional plasma channel. For most scattering angles daughter wave growth is enhanced by lateral reflections within the channel. At late times the two-dimensional interaction approaches a one-dimensional damped mode in which the dissipative loss from lateral transmission of the Stokes wave through the channel boundaries is equivalent to an overall damping of the Stokes amplitudes within the channel. (C) 2000 American Institute of Physics. [S1070-664X(00)01712-2]. C1 Univ Rochester, Dept Phys & Astron, Rochester, NY 14627 USA. Univ Rochester, Laser Energet Lab, Rochester, NY 14623 USA. Univ Rochester, Dept Mech Engn, Rochester, NY 14627 USA. RP Turano, EJ (reprint author), Univ Calif Lawrence Livermore Natl Lab, 7000 E Ave, Livermore, CA 94550 USA. RI McKinstrie, Colin/L-7879-2013 NR 25 TC 3 Z9 3 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 1070-664X J9 PHYS PLASMAS JI Phys. Plasmas PD DEC PY 2000 VL 7 IS 12 BP 5096 EP 5105 DI 10.1063/1.1319332 PG 10 WC Physics, Fluids & Plasmas SC Physics GA 378YH UT WOS:000165612900035 ER PT J AU Hicks, DG Li, CK Seguin, FH Ram, AK Frenje, JA Petrasso, RD Soures, JM Glebov, VY Meyerhofer, DD Roberts, S Sorce, C Stockl, C Sangster, TC Phillips, TW AF Hicks, DG Li, CK Seguin, FH Ram, AK Frenje, JA Petrasso, RD Soures, JM Glebov, VY Meyerhofer, DD Roberts, S Sorce, C Stockl, C Sangster, TC Phillips, TW TI Charged-particle acceleration and energy loss in laser-produced plasmas SO PHYSICS OF PLASMAS LA English DT Article ID FUSION EXPERIMENTS; STOPPING POWERS; HEAVY-IONS; TEMPERATURE; VACUUM; TARGET; EXPANSION; SYSTEM; OMEGA AB Spectral measurements have been made of charged fusion products produced in deuterium + helium-3 filled targets irradiated by the OMEGA laser system [T, R, Boehly et al., Opt. Commun. 133, 495 (1997)]. Comparing the energy shifts of four particle types has allowed two distinct physical processes to be probed: Electrostatic acceleration in the low-density corona and energy loss in the high-density target. When the fusion burn occurred during the laser pulse, particle energy shifts: were dominated by acceleration effects. Using a simple model for the accelerating field region, the time history of the target electrostatic potential was found and shown to decay to zero soon after laser irradiation was complete. When the fusion burn occurred after the pulse, particle energy shifts were dominated by energy losses in the target, allowing fundamental charged-particle stopping-power predictions to be tested. The results provide the first experimental verification of the general form of stopping power theories over a wide velocity range. (C) 2000 American Institute of Physics. [S1070-664X(00)03012-3]. C1 MIT, Plasma Sci & Fus Ctr, Cambridge, MA 02139 USA. Univ Rochester, Laser Energet Lab, Rochester, NY 14623 USA. Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Hicks, DG (reprint author), Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RI Hicks, Damien/B-5042-2015 OI Hicks, Damien/0000-0001-8322-9983 NR 28 TC 39 Z9 39 U1 0 U2 7 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 1070-664X J9 PHYS PLASMAS JI Phys. Plasmas PD DEC PY 2000 VL 7 IS 12 BP 5106 EP 5117 DI 10.1063/1.1320467 PG 12 WC Physics, Fluids & Plasmas SC Physics GA 378YH UT WOS:000165612900036 ER PT J AU Koga, JK Naumova, N Kando, M Tsintsadze, LN Nakajima, K Bulanov, SV Dewa, H Kotaki, H Tajima, T AF Koga, JK Naumova, N Kando, M Tsintsadze, LN Nakajima, K Bulanov, SV Dewa, H Kotaki, H Tajima, T TI Fixed blueshift of high intensity short pulse lasers propagating in gas chambers SO PHYSICS OF PLASMAS LA English DT Article ID ORDER HARMONIC-GENERATION; WHITE-LIGHT CONTINUUM; FEMTOSECOND PULSES; RARE-GASES; UNDERDENSE PLASMA; IONIZATION; AIR; ULTRASHORT; DYNAMICS; MEDIA AB An explanation is given for the fixed blueshift observed of an intense short pulse laser propagating lin a gas chamber filled with helium. The observed shift is found to be independent of the laser power and gas pressure above some critical power. The results are explained by the formation of filaments, which occur due to nonlinear gas polarization effects. The blueshift is in qualitative agreement with a one dimensional particle-in-cell simulation including ionization of the gas. (C) 2000 American Institute of Physics. [S1070-664X(00)03212-2]. C1 JAERI, Adv Photon Res Ctr, Kyoto, Japan. Russian Acad Sci, Inst Gen Phys, Moscow 117333, Russia. High Energy Accelerator Res Org, Tsukuba, Ibaraki, Japan. Univ Texas, Dept Phys, Austin, TX 78712 USA. Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Koga, JK (reprint author), JAERI, Adv Photon Res Ctr, Kyoto, Japan. EM koga@apr.jaeri.go.jp RI Bulanov, Sergei/A-1721-2013 NR 38 TC 24 Z9 24 U1 1 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 1070-664X J9 PHYS PLASMAS JI Phys. Plasmas PD DEC PY 2000 VL 7 IS 12 BP 5223 EP 5231 DI 10.1063/1.1320469 PG 9 WC Physics, Fluids & Plasmas SC Physics GA 378YH UT WOS:000165612900047 ER PT J AU van Milligen, BP Hidalgo, C Carreras, BA AF van Milligen, BP Hidalgo, C Carreras, BA TI Comment on "The Hurst exponent and long-time correlation" SO PHYSICS OF PLASMAS LA English DT Editorial Material ID FLUCTUATIONS C1 Asociac Euratom Ciemat, Madrid 28040, Spain. Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP van Milligen, BP (reprint author), Asociac Euratom Ciemat, Madrid 28040, Spain. RI van Milligen, Boudewijn/H-5121-2015; Hidalgo, Carlos/H-6109-2015 OI van Milligen, Boudewijn/0000-0001-5344-6274; NR 7 TC 6 Z9 6 U1 0 U2 3 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 1070-664X J9 PHYS PLASMAS JI Phys. Plasmas PD DEC PY 2000 VL 7 IS 12 BP 5267 EP 5268 DI 10.1063/1.1319336 PG 2 WC Physics, Fluids & Plasmas SC Physics GA 378YH UT WOS:000165612900054 ER PT J AU Drell, SD AF Drell, SD TI On physics and national security SO PHYSICS TODAY LA English DT Article C1 Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. RP Drell, SD (reprint author), Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. NR 6 TC 2 Z9 2 U1 0 U2 1 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0031-9228 J9 PHYS TODAY JI Phys. Today PD DEC PY 2000 VL 53 IS 12 BP 25 EP 29 DI 10.1063/1.1341911 PG 5 WC Physics, Multidisciplinary SC Physics GA 377MV UT WOS:000165518100016 ER PT J AU Crease, RP AF Crease, RP TI A top ten for science and society SO PHYSICS WORLD LA English DT Editorial Material C1 SUNY Stony Brook, Dept Philosophy, Stony Brook, NY 11794 USA. Brookhaven Natl Lab, Upton, NY 11973 USA. RP Crease, RP (reprint author), SUNY Stony Brook, Dept Philosophy, Stony Brook, NY 11794 USA. NR 1 TC 1 Z9 1 U1 0 U2 0 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0953-8585 J9 PHYS WORLD JI Phys. World PD DEC PY 2000 VL 13 IS 12 BP 17 EP 18 PG 2 WC Physics, Multidisciplinary SC Physics GA 381KD UT WOS:000165761200016 ER PT J AU Anderson, R AF Anderson, R TI Bolstering the backbone of the Natural Gas Industry SO PIPELINE & GAS JOURNAL LA English DT Article C1 NETL, Nat Gas Infrastruct Reliabil, Morgantown, WV USA. RP Anderson, R (reprint author), NETL, Nat Gas Infrastruct Reliabil, Morgantown, WV USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU OILDOM PUBLISHING CO TEXAS INC PI HOUSTON PA 14515 BRIARHILLS PARKWAY SUITE 208, HOUSTON, TX 77077 USA SN 0032-0188 J9 PIPELINE GAS J JI Pipeline Gas J. PD DEC PY 2000 VL 227 IS 12 BP 14 EP + PG 5 WC Engineering, Petroleum SC Engineering GA 387WH UT WOS:000166144500033 ER PT J AU Katul, GG Ellsworth, DS Lai, CT AF Katul, GG Ellsworth, DS Lai, CT TI Modelling assimilation and intercellular CO2 from measured conductance: a synthesis of approaches SO PLANT CELL AND ENVIRONMENT LA English DT Article DE carbon isotope; conductance; CO2 assimilation; elevated CO2; Free Air CO2 Enrichment; intercellular CO2; pine forest ID CARBON-DIOXIDE EXCHANGE; WATER-VAPOR EXCHANGE; PINUS-TAEDA L; STOMATAL CONDUCTANCE; ATMOSPHERIC CO2; CANOPY CONDUCTANCE; DECIDUOUS FOREST; EDDY-CORRELATION; GAS-EXCHANGE; PHOTOSYNTHETIC CAPACITY AB A spectrum of models that estimate assimilation rate A from intercellular carbon dioxide concentration (C-i) and measured stomatal conductance to CO2 (g(c)) were investigated using leaf-level gas exchange measurements. The gas exchange measurements were performed in a uniform loblolly pine stand (Pinus taeda L.) using the Free Air CO2 Enrichment (FACE) facility under ambient and elevated atmospheric CO2 for 3 years. These measurements were also used to test a newly proposed framework that combines basic properties of the A-C-i curve with a Fickian diffusion transport model to predict the relationship between C-i/C-a and g(c), where C-a is atmospheric carbon dioxide concentration. The widely used Ball-Berry model and five other models as well as the biochemical model proposed by Farquhar et al. (1980) were also reformulated to express variations in C-i/C-a as a function of their corresponding driving mechanisms. To assess the predictive capabilities of these approaches, their respective parameters were estimated from independent measurements of long-term stable carbon isotope determinations (delta C-13), meteorological variables, and ensemble A-C-i curves. All eight approaches reproduced the measured A reasonably well, in an ensemble sense, from measured water vapour conductance and modeled C-i/C-a. However, the scatter in the instantaneous A estimates was sufficiently large for both ambient and elevated C-a to suggest that other transient processes were not explicitly resolved by all eight parameterizations. An important finding from our analysis is that added physiological complexity in modeling C-i/C-a (when g(c) is known) need not always translate to increased accuracy in predicting A. Finally, the broader utility of these approaches to estimate assimilation and net ecosystem exchange is discussed in relation to elevated atmospheric CO2. C1 Duke Univ, Sch Environm, Durham, NC 27708 USA. Brookhaven Natl Lab, Dept Environm Sci, Upton, NY 11973 USA. RP Katul, GG (reprint author), Duke Univ, Sch Environm, Box 90328, Durham, NC 27708 USA. RI Katul, Gabriel/A-7210-2008; OI Katul, Gabriel/0000-0001-9768-3693; Ellsworth, David/0000-0002-9699-2272 NR 78 TC 86 Z9 89 U1 4 U2 25 PU BLACKWELL SCIENCE LTD PI OXFORD PA P O BOX 88, OSNEY MEAD, OXFORD OX2 0NE, OXON, ENGLAND SN 0140-7791 J9 PLANT CELL ENVIRON JI Plant Cell Environ. PD DEC PY 2000 VL 23 IS 12 BP 1313 EP 1328 DI 10.1046/j.1365-3040.2000.00641.x PG 16 WC Plant Sciences SC Plant Sciences GA 376MR UT WOS:000165461800003 ER PT J AU White, JA Todd, T Newman, T Focks, N Girke, T de Ilarduya, OM Jaworski, JG Ohlrogge, JB Benning, C AF White, JA Todd, T Newman, T Focks, N Girke, T de Ilarduya, OM Jaworski, JG Ohlrogge, JB Benning, C TI A new set of Arabidopsis expressed sequence tags from developing seeds. The metabolic pathway from carbohydrates to seed oil SO PLANT PHYSIOLOGY LA English DT Article ID FATTY-ACID SYNTHESIS; BRASSICA-NAPUS L; GENE-EXPRESSION; DEVELOPING EMBRYOS; MOLECULAR CHARACTERIZATION; FUNCTIONAL GENOMICS; MESSENGER-RNA; BEAN-SEEDS; PLASTIDS; PROTEIN AB Large-scale single-pass sequencing of cDNAs from different plants has provided an extensive reservoir for the cloning of genes, the evaluation of tissue-specific gene expression, markers for map-based cloning, and the annotation of genomic sequences. Although as of January 2000 GenBank contained over 220,000 entries of expressed sequence tags (ESTs) from plants, most publicly available plant ESTs are derived from vegetative tissues and relatively few ESTs are specifically derived from developing seeds. However, important morphogenetic processes are exclusively associated with seed and embryo development and the metabolism of seeds is tailored toward the accumulation of economically valuable storage compounds such as oil. Here we describe a new set of ESTs from Arabidopsis, which has been derived from 5- to 13-d-old immature seeds. Close to 28,000 cDNAs have been screened by DNA/DNA hybridization and approximately 10,500 new Arabidopsis ESTs have been generated and analyzed using different bioinformatics tools. Approximately 40% of the ESTs currently have no match in dbEST, suggesting many represent mRNAs derived from genes that are specifically expressed in seeds. Although these data can be mined with many different biological questions in mind, this study emphasizes the import of photosynthate into developing embryos, its conversion into seed oil, and the regulation of this pathway. C1 Michigan State Univ, Dept Biochem & Mol Biol, E Lansing, MI 48824 USA. Michigan State Univ, Dept Bot & Plant Pathol, E Lansing, MI 48824 USA. Michigan State Univ, US DOE, Plant Res Lab, E Lansing, MI 48824 USA. Miami Univ, Dept Chem & Biochem, Oxford, OH 45056 USA. RP Benning, C (reprint author), Michigan State Univ, Dept Biochem & Mol Biol, E Lansing, MI 48824 USA. RI Jaworski, Jan/N-2255-2014; OI Jaworski, Jan/0000-0003-3309-4915 NR 42 TC 164 Z9 193 U1 1 U2 9 PU AMER SOC PLANT PHYSIOLOGISTS PI ROCKVILLE PA 15501 MONONA DRIVE, ROCKVILLE, MD 20855 USA SN 0032-0889 J9 PLANT PHYSIOL JI Plant Physiol. PD DEC PY 2000 VL 124 IS 4 BP 1582 EP 1594 DI 10.1104/pp.124.4.1582 PG 13 WC Plant Sciences SC Plant Sciences GA 385BV UT WOS:000165982500023 PM 11115876 ER PT J AU Kim, JH Cho, HT Kende, H AF Kim, JH Cho, HT Kende, H TI alpha-Expansins in the semiaquatic ferns Marsilea quadrifolia and Regnellidium diphyllum: evolutionary aspects and physiological role in rachis elongation SO PLANTA LA English DT Article DE rachis elongation; ethylene; expansin; Marsilea; Regnellidium; submergence ID CELL-WALL EXTENSIBILITY; SEMI-AQUATIC FERN; DEEP-WATER RICE; ETHYLENE BIOSYNTHESIS; PLANTS; EXTENSION; PROTEINS; EXPRESSION; INTERNODES; ENZYMES AB To investigate the evolutionary history of expansins and their role in cell elongation in early land plants, we isolated two alpha -expansin genes, Mq-EXP1 and Rd-EXP1, respectively, from the semiaquatic ferns Marsilea quadrifolia L. and Regnellidium diphyllum Lindm. The deduced amino acid sequences of the fern expansins exhibit a high degree of identity to those of seed plants, showing that expansin genes were conserved during the evolution of vascular plants. Gel-blot analysis of M. quadrifolia and R. diphyllum genomic DNA indicated that, in both ferns, alpha -expansins are encoded by multigene families. Expression of alpha -expansin genes probed with Mq-EXP1 was confined to the elongating region of the Marsilea rachis. Cell-wall proteins of M. quadrifolia induced in-vitro extension of acidified cucumber cell walls. In R. diphyllum, expression of Rd-EXP1 increased when elongation of the rachis was enhanced by submergence or ethylene. These results indicate that alpha -expansins act as wall-loosening proteins in ferns, as has been proposed for angiosperms. In addition, Rd-EXP1 may play a role in mediating elongation of the rachis in submerged plants. C1 Michigan State Univ, MSU DOE Plant Res Lab, E Lansing, MI 48824 USA. Michigan State Univ, Dept Bot & Plant Pathol, E Lansing, MI 48824 USA. RP Kende, H (reprint author), Michigan State Univ, MSU DOE Plant Res Lab, E Lansing, MI 48824 USA. NR 28 TC 35 Z9 42 U1 1 U2 4 PU SPRINGER-VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 USA SN 0032-0935 J9 PLANTA JI Planta PD DEC PY 2000 VL 212 IS 1 BP 85 EP 92 DI 10.1007/s004250000367 PG 8 WC Plant Sciences SC Plant Sciences GA 385KD UT WOS:000166002400011 PM 11219587 ER PT J AU Petty, CC Luce, TC Politzer, PA Wade, MR Allen, SL Austin, ME Bray, B Burrell, KH Casper, TA Chu, MS Ferron, JR Fredrickson, ED Garofalo, AM Gohil, P Gorelov, I Greenfield, CM Heidbrink, WW Hsieh, CL Hyatt, AW Jayakumar, R Johnson, LC Kinsey, JE La Haye, RJ Lao, LL Lasnier, CJ Lazarus, EA Leonard, AW Lin-Liu, YR Lohr, J Mahdavi, MA Makowski, MA McKee, GR Murakami, M Navratil, GA Okabayashi, M Petrie, TW Pinsker, RI Prater, R Rettig, CL Rhodes, TL Rice, BW Scoville, JT Staebler, GM Strait, EJ Taylor, TS Watkins, JG West, WP Wolf, NS Wong, KL AF Petty, CC Luce, TC Politzer, PA Wade, MR Allen, SL Austin, ME Bray, B Burrell, KH Casper, TA Chu, MS Ferron, JR Fredrickson, ED Garofalo, AM Gohil, P Gorelov, I Greenfield, CM Heidbrink, WW Hsieh, CL Hyatt, AW Jayakumar, R Johnson, LC Kinsey, JE La Haye, RJ Lao, LL Lasnier, CJ Lazarus, EA Leonard, AW Lin-Liu, YR Lohr, J Mahdavi, MA Makowski, MA McKee, GR Murakami, M Navratil, GA Okabayashi, M Petrie, TW Pinsker, RI Prater, R Rettig, CL Rhodes, TL Rice, BW Scoville, JT Staebler, GM Strait, EJ Taylor, TS Watkins, JG West, WP Wolf, NS Wong, KL TI Advanced tokamak physics in DIII-D SO PLASMA PHYSICS AND CONTROLLED FUSION LA English DT Article; Proceedings Paper CT 27th European-Physical-Society Conference on Controlled Fusion and Plasma Physics CY JUN 12-16, 2000 CL BUDAPEST, HUNGARY ID NONINDUCTIVE CURRENT; ENERGY CONFINEMENT; TEARING MODES; TRANSPORT; PLASMAS; RATIO; ION; TURBULENCE; PROFILE; HEAT AB Advanced tokamaks seek to achieve a high bootstrap current fraction without sacrificing fusion power density or fusion gain. Good progress has been made towards the DIII-D research goal of demonstrating a high-beta advanced tokamak plasma in steady state with a relaxed, fully non-inductive current profile and a bootstrap current fraction greater than 50%. The limiting factors for transport, stability, and current profile control in advanced operating modes are discussed in this paper. C1 Gen Atom Co, San Diego, CA 92186 USA. Oak Ridge Natl Lab, Oak Ridge, TN USA. Univ Calif Lawrence Livermore Natl Lab, Livermore, CA USA. Univ Texas, Austin, TX 78712 USA. Princeton Plasma Phys Lab, Princeton, NJ 08543 USA. Columbia Univ, New York, NY USA. Univ Calif Irvine, Irvine, CA USA. Lehigh Univ, Bethlehem, PA 18015 USA. Univ Wisconsin, Madison, WI USA. Univ Calif Los Angeles, Los Angeles, CA 90024 USA. Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Petty, CC (reprint author), Gen Atom Co, POB 85608, San Diego, CA 92186 USA. NR 36 TC 9 Z9 9 U1 0 U2 3 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 DEC PY 2000 VL 42 SU 12B BP B75 EP B85 DI 10.1088/0741-3335/42/12B/307 PG 11 WC Physics, Fluids & Plasmas SC Physics GA 387WR UT WOS:000166145300009 ER PT J AU Spielman, RB Deeney, C Douglas, MR Chandler, GA Cuneo, ME Nash, TJ Porter, JL Ruggles, LE Sanford, TWL Stygar, WA Struve, KW Matzen, MK McDaniel, DH Peterson, DL Hammer, JH AF Spielman, RB Deeney, C Douglas, MR Chandler, GA Cuneo, ME Nash, TJ Porter, JL Ruggles, LE Sanford, TWL Stygar, WA Struve, KW Matzen, MK McDaniel, DH Peterson, DL Hammer, JH TI Wire-array z pinches as intense x-ray sources for inertial confinement fusion SO PLASMA PHYSICS AND CONTROLLED FUSION LA English DT Article; Proceedings Paper CT 27th European-Physical-Society Conference on Controlled Fusion and Plasma Physics CY JUN 12-16, 2000 CL BUDAPEST, HUNGARY ID POWER; DENSITY AB Progress in pulsed power technologies has enabled the use of z pinches for inertial confinement Fusion (ICF). Z pinches can provide x-ray powers of 200 TW and x-ray energies approaching 2 MJ. Computational capabilities have advanced to the point that 2-D radiation magneto-hydrodynamics computer codes can be used as detailed design tools. Several ICF configurations have been proposed. The z-pinch driven hohlraum configuration (ZPDH) uses two separate z pinches to provide the radiation to drive an ICF capsule. The decoupling of the z-pinch From the target in the ZPHD permits physics issues such as radiation production, transport, symmetry, and capsule hydrodynamics to be treated separately. The penalty is the increased energy requirement. ZPDH experiments have demonstrated the potential for acceptable capsule symmetry and radiation transport. The dynamic hohlraum concept uses the z pinch itself as a radiation case around the capsule providing the potential for very high coupling efficiency but at the expense of complex z-pinch/target coupling physics. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Spielman, RB (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. NR 17 TC 10 Z9 14 U1 0 U2 2 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 DEC PY 2000 VL 42 SU 12B BP B157 EP B164 DI 10.1088/0741-3335/42/12B/312 PG 8 WC Physics, Fluids & Plasmas SC Physics GA 387WR UT WOS:000166145300014 ER PT J AU Wootton, AJ Perkins, LJ AF Wootton, AJ Perkins, LJ TI Issues for magnetic and inertial fusion energy development SO PLASMA PHYSICS AND CONTROLLED FUSION LA English DT Article; Proceedings Paper CT 27th European-Physical-Society Conference on Controlled Fusion and Plasma Physics CY JUN 12-16, 2000 CL BUDAPEST, HUNGARY ID CONFINEMENT FUSION; BURN PERFORMANCE; IGNITION; TARGETS; GAIN; MICROSPHERES; REQUIREMENTS; PHYSICS; DRIVER; ION AB A discussion of the issues facing both magnetic and inertial fusion schemes for the generation of energy is presented. For magnetic fusion, the conventional tokamak device appears likely to 'work', i.e. it will convert wall plug power into plasma temperature and reasonable energy gain will be obtained. However, it is viewed by many as unacceptable as a commercial reactor candidate-i.e. it is too expensive and too complex. Arguing that within a given concept (but not between concepts) compactness is advantageous, a steady-state energy balance model is used to illustrate how to reduce size. Inertial fusion offers potential advantages over its magnetic counterpart, but while physics progress has been maintained, hot-spot ignition and propagating burn remain to be demonstrated in the laboratory. The proposed solutions to inertial fusion technology challenges, mostly very different from those involved in magnetic fusion, also require demonstrating. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Wootton, AJ (reprint author), Univ Calif Lawrence Livermore Natl Lab, POB 808, Livermore, CA 94550 USA. NR 49 TC 1 Z9 1 U1 0 U2 1 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0741-3335 J9 PLASMA PHYS CONTR F JI Plasma Phys. Control. Fusion PD DEC PY 2000 VL 42 SU 12B BP B125 EP B141 DI 10.1088/0741-3335/42/12B/310 PG 17 WC Physics, Fluids & Plasmas SC Physics GA 387WR UT WOS:000166145300012 ER PT J AU Hohne, GWH Rastogi, S Wunderlich, B AF Hohne, GWH Rastogi, S Wunderlich, B TI High pressure differential scanning calorimetry of poly(4-methyl-pentene-1) SO POLYMER LA English DT Article; Proceedings Paper CT International Symposium on Semicrystalline Polymers in Memory of Andrew Keller held at the American-Chemical-Society National Meeting CY AUG 23-26, 1999 CL NEW ORLEANS, LOUISIANA SP Amer Chem Soc DE high-pressure calorimetry; poly(4-methyl pentene-1); phase diagram ID TEMPERATURE; HEAT; TRANSITION; FUSION; DSC AB The polymer poly(4-methyl pentene-1), P4MP1, displays an unusual pressure-temperature phase diagram. The previous exploration of this phase behavior through X-ray diffraction has been extended through high-pressure calorimetry. The resulting phase diagram displays a melt area, the common tetragonal crystal phase, and a high-pressure phase of hexagonal symmetry. Below the glass transition temperature of the amorphous fraction, the tetragonal phase can be disordered by application of pressure in what seems to be a frustrated transition that leads to a conformationally disordered glass. The transitions between the phases, previously postulated on structural evidence, are supported by calorimetry. Observed are the following: (1) isothermal crystal disordering by increasing of pressure; (2) isobaric crystal perfection on heating, and disordering on cooling; (3) sign inversion of the pressure coefficient of the melting temperature. Equilibrium and nonequilibrium features of the phase diagram are discussed. (C) 2000 Elsevier Science Ltd. All rights reserved. C1 Univ Ulm, Sect Calorimetry, D-89069 Ulm, Germany. Eindhoven Univ Technol, Dutch Polymer Inst, Eindhover Polymer Lab, NL-5600 MB Eindhoven, Netherlands. Univ Tennessee, Dept Chem, Knoxville, TN 37996 USA. Oak Ridge Natl Lab, Div Chem & Analyt Sci, Oak Ridge, TN 37831 USA. RP Hohne, GWH (reprint author), Univ Ulm, Sect Calorimetry, POB 4065, D-89069 Ulm, Germany. NR 27 TC 17 Z9 17 U1 0 U2 3 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0032-3861 J9 POLYMER JI Polymer PD DEC PY 2000 VL 41 IS 25 BP 8869 EP 8878 DI 10.1016/S0032-3861(00)00230-5 PG 10 WC Polymer Science SC Polymer Science GA 353KD UT WOS:000089272600015 ER PT J AU Stansfield, S Shawver, D Sobel, A Prasad, M Tapia, L AF Stansfield, S Shawver, D Sobel, A Prasad, M Tapia, L TI Design and implementation of a virtual reality system and its application to training medical first responders SO PRESENCE-TELEOPERATORS AND VIRTUAL ENVIRONMENTS LA English DT Article ID EMERGENCY-MEDICINE; SIMULATION; ENVIRONMENTS; PROTOTYPE; TEAM AB This paper presents the design and implementation of a distributed virtual reality (VR) platform that was developed to support the training of multiple users who must perform complex tasks in which situation assessment and critical thinking are the primary components of success. The system is fully immersive and multimodal, and users are represented as tracked, full-body figures, The system supports the manipulation of virtual objects, allowing users to act upon the environment in a natural manner. The underlying intelligent simulation component creates an interactive, responsive world in which the consequences of such actions are presented within a realistic, time-critical scenario. The focus of this work has been on the training of medical emergency-response personnel. BjoSimMER an application of the system to training first responders to an act of bio-terrorism, has been implemented and is presented throughout the paper as a concrete example of how the underlying platform architecture supports complex training tasks. Finally, a preliminary field study was performed at the Texas Engineering Extension Service Fire Protection Training Division. The study focused on individual, rather than team, interaction with the system and was designed to gauge user acceptance of VR as a training tool. The results of this study are presented. C1 Ithaca Coll, Ithaca, NY 14850 USA. Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Stansfield, S (reprint author), Ithaca Coll, Ithaca, NY 14850 USA. NR 37 TC 22 Z9 22 U1 0 U2 3 PU M I T PRESS PI CAMBRIDGE PA FIVE CAMBRIDGE CENTER, CAMBRIDGE, MA 02142 USA SN 1054-7460 J9 PRESENCE-TELEOP VIRT JI Presence-Teleoper. Virtual Env. PD DEC PY 2000 VL 9 IS 6 BP 524 EP 556 DI 10.1162/105474600300040376 PG 33 WC Computer Science, Cybernetics; Computer Science, Software Engineering SC Computer Science GA 415RL UT WOS:000167736400002 ER PT J AU Jenkins, RA AF Jenkins, RA TI Commentary SO PREVENTIVE MEDICINE LA English DT Editorial Material C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Jenkins, RA (reprint author), Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. NR 1 TC 1 Z9 1 U1 0 U2 0 PU ACADEMIC PRESS INC PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0091-7435 J9 PREV MED JI Prev. Med. PD DEC PY 2000 VL 31 IS 6 BP 629 EP 630 DI 10.1006/pmed.2000.0783 PG 2 WC Public, Environmental & Occupational Health; Medicine, General & Internal SC Public, Environmental & Occupational Health; General & Internal Medicine GA 386EC UT WOS:000166046300001 PM 11133326 ER PT J AU Fitch, JP Sokhansanj, B AF Fitch, JP Sokhansanj, B TI Genomic engineering: Moving beyond DNA sequence to function SO PROCEEDINGS OF THE IEEE LA English DT Review DE DNA; expression profiling; functional genomics; genomics; protein; proteomics; stochastic simulation ID EXACT STOCHASTIC SIMULATION; COUPLED CHEMICAL-REACTIONS; MYOTONIC-DYSTROPHY LOCUS; GENE-EXPRESSION; CAPILLARY-ELECTROPHORESIS; ESCHERICHIA-COLI; ELECTROCHEMICAL DETECTION; DROSOPHILA-MELANOGASTER; FLUORESCENCE DETECTION; GEL-ELECTROPHORESIS AB The DNA sequence of the human genome has been determined. This significant scientific milestone has been a multidisciplinary effort sponsored by both public and private investments. Engineering and computer science contributions have been essential to success, especially with the accelerated schedules of the Human Genome Project. A tutorial summary of the biological and health implications of sequencing the human genome is presented together with examples of how genome data from human and other organisms are already used. Engineering contributions to sequencing are identified as well as predictions of how engineering methods may contribute to the "postsequencing" era of biology. C1 Lawrence Livermore Natl Lab, Biol & Biotechnol Res Program, Livermore, CA 94550 USA. RP Lawrence Livermore Natl Lab, Biol & Biotechnol Res Program, Livermore, CA 94550 USA. EM jpfitch@llnl.gov; sokhansanj@llnl.gov NR 130 TC 29 Z9 29 U1 0 U2 2 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855-4141 USA SN 0018-9219 EI 1558-2256 J9 P IEEE JI Proc. IEEE PD DEC PY 2000 VL 88 IS 12 BP 1949 EP 1971 DI 10.1109/5.899061 PG 23 WC Engineering, Electrical & Electronic SC Engineering GA 401BW UT WOS:000166907900010 ER PT J AU Cave, JW Werner, K Wemmer, DE AF Cave, JW Werner, K Wemmer, DE TI Backbone dynamics of sequence specific recognition and binding by the yeast Pho4 bHLH domain probed by NMR SO PROTEIN SCIENCE LA English DT Article DE helix-loop-helix protein; nonspecific binding; Pho4; protein dynamics; sequence-specific binding; spectral density mapping ID HELIX-LOOP-HELIX; MAGNETIC-RESONANCE RELAXATION; MODEL-FREE APPROACH; DNA-BINDING; TRANSCRIPTION FACTOR; CRYSTAL-STRUCTURE; LEUCINE-ZIPPER; BASIC REGION; SACCHAROMYCES-CEREVISIAE; SECONDARY STRUCTURE AB Backbone dynamics of the basic/helix-loop-helix domain of Pho4 from Saccharomyces cerevisiae have been probed by NMR techniques, in the absence of DNA. nonspecifically bound to DNA and bound to cognate DNA. Alpha proton chemical shift indices and nuclear Overhauser effect patterns were used to elucidate the secondary structure in these states. These secondary structures are compared to the co-crystal complex of Pho4 bound to a cognate DNA sequence (Shimizu T Toumoto A, Ihara K, Shimizu M, Kyogou Y, Ogawa N, Oshima Y, Hakoshima T, 1997, EMBO J 15: 4689-4697). The dynamic information provides insight into the nature of this DNA binding domain as it progresses from free in solution to a specifically bound DNA complex. Relative to the unbound form, we show that formation of either the nonspecific and cognate DNA bound complexes involves a large change in conformation and backbone dynamics of the basic region. The nonspecific and cognate complexes, however, have nearly identical secondary structure and backbone dynamics. We also present evidence for conformational flexibility at a highly conserved glutamate basic region residue. These results, art: discussed in relation to the mechanism of sequence specific recognition and binding. C1 Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Phys Biosci Div, Calvin Lab, Berkeley, CA 94720 USA. RP Wemmer, DE (reprint author), Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. FU NIGMS NIH HHS [GM08295] NR 53 TC 21 Z9 21 U1 0 U2 0 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 DEC PY 2000 VL 9 IS 12 BP 2354 EP 2365 PG 12 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA 396YH UT WOS:000166665200009 PM 11206057 ER PT J AU Teplova, M Tereshko, V Sanishvili, R Joachimiak, A Bushueva, T Anderson, WF Egli, M AF Teplova, M Tereshko, V Sanishvili, R Joachimiak, A Bushueva, T Anderson, WF Egli, M TI The structure of the yrdC gene product from Escherichia coli reveals a new fold and suggests a role in RNA binding SO PROTEIN SCIENCE LA English DT Article DE protein folding; RNA; structural genomics; Sua5; X-ray crystallography; YrdC ID TRANSLATION INITIATION DEFECT; ANGSTROM CRYSTAL-STRUCTURE; SACCHAROMYCES-CEREVISIAE; RHODOBACTER-CAPSULATUS; PROTEIN; GENOMICS; HYPF; IDENTIFICATION; SUPPRESSORS; MATURATION AB The yrdC family of genes codes for proteins that occur both independently and as a domain in proteins that have been implicated in regulation. An example for the latter case is the sua5 gene from yeast. Sua5 was identified as a suppressor of a translation initiation defect in cytochrome c and is required for normal growth in yeast (Na JG, Pinto I, Hampsey M, 1992, Genetics 11:791-801). However, the function of the Sua5 protein remains unknown: Sua5 could act either at the transcriptional or the posttranscriptional levels to compensate for an aberrant translation start codon in the cyc gene. To potentially learn more about the function of YrdC and proteins featuring this domain, the crystal structure of the YrdC protein from Escherichia coli was determined at a resolution of 2.0 Angstrom. YrdC adopts a new fold with no obvious similarity to those of other proteins with known three-dimensional (3D) structure. The protein features a large concave surface on one side that exhibits a positive electrostatic potential. The dimensions of this depression, its curvature, and the fact that conserved basic amino acids are located at its floor suggest that YrdC may be a nucleic acid binding protein. An investigation of YrdC's binding affinities for single- and double-stranded RNA and DNA fragments as well as tRNAs demonstrates that YrdC binds preferentially to double-stranded RNA. Our work provides evidence that 3D structures of functionally uncharacterized gene products with unique sequences can yield novel folds and functional insights. C1 Vanderbilt Univ, Dept Biol Sci, Nashville, TN 37235 USA. Argonne Natl Lab, Biosci Div, Struct Biol Ctr, Argonne, IL 60439 USA. Russian Acad Med Sci, Cardiol Res Ctr, Moscow 121552, Russia. Northwestern Univ, Sch Med, Dept Biol Chem & Mol Pharmacol, Chicago, IL 60611 USA. RP Egli, M (reprint author), Vanderbilt Univ, Dept Biol Sci, Box 1634,Stn B, Nashville, TN 37235 USA. FU NIGMS NIH HHS [GM-55237] NR 41 TC 53 Z9 56 U1 1 U2 1 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 DEC PY 2000 VL 9 IS 12 BP 2557 EP 2566 PG 10 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA 396YH UT WOS:000166665200029 PM 11206077 ER PT J AU Drinkwater, MJ Jones, JB Gregg, MD Phillipps, S AF Drinkwater, MJ Jones, JB Gregg, MD Phillipps, S TI Compact stellar systems in the Fornax Cluster: Super-massive star clusters or extremely compact dwarf galaxies? SO PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF AUSTRALIA LA English DT Article DE galaxies : star clusters; alaxies : dwarf; galaxies : formation ID GLOBULAR-CLUSTERS; NGC 1399; SPECTROSCOPIC SURVEY; RADIAL-VELOCITIES; NGC-1399; CATALOG; VIRGO AB We describe a population of compact objects in the centre of the Fornax Cluster which were discovered as part of our 2dF Fornax Spectroscopic Survey. These objects have spectra typical of old stellar systems, but are unresolved on photographic sky survey plates. They have absolute magnitudes - 13 < M(B) <-11 so they are 10 times more luminous than any Galactic globular clusters. but fainter than any known compact dwarf galaxies. These objects are all within 30 arcminutes of the central galaxy of the cluster, NGC 1399. but are distributed over larger radii than the globular cluster system of that galaxy. We suggest that these objects are either super-massive star clusters (intra-cluster globular clusters or tidally stripped nuclei of dwarf galaxies) or a new type of low-luminosity, compact elliptical dwarf ('M32-type') galaxy. The best way to test these hypotheses will be To obtain high-resolution imaging and high-dispersion spectroscopy to determine their structures and mass-to-light ratios. This will allow us to compare them to known compact objects and establish whether they represent a new class of hitherto unknown stellar system. C1 Univ Melbourne, Sch Phys, Melbourne, Vic 3010, Australia. Univ Bristol, Dept Phys, Bristol BS8 1TL, Avon, England. Univ Calif Davis, Livermore, CA 94550 USA. Lawrence Livermore Natl Lab, Inst Geophys & Planetary Phys, Livermore, CA 94550 USA. RP Drinkwater, MJ (reprint author), Univ Melbourne, Sch Phys, Melbourne, Vic 3010, Australia. EM m.drinkwater@physics.unimelb.edu.au; B.Jones@bristol.ac.uk; gregg@igpp.ucllnl.org; S.Phillipps@bristol.ac.uk RI Drinkwater, Michael/A-2201-2008; OI Drinkwater, Michael/0000-0003-4867-0022; Jones, Bryn/0000-0002-4679-5625; Phillipps, Steven/0000-0001-5991-3486 NR 25 TC 159 Z9 160 U1 0 U2 1 PU CSIRO PUBLISHING PI COLLINGWOOD PA 150 OXFORD ST, PO BOX 1139, COLLINGWOOD, VICTORIA 3066, AUSTRALIA SN 1323-3580 J9 PUBL ASTRON SOC AUST JI Publ. Astron. Soc. Aust. PD DEC PY 2000 VL 17 IS 3 BP 227 EP 233 PG 7 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 430NF UT WOS:000168579500004 ER PT J AU Pisharody, M Job, PK Berkvens, P Colomp, P AF Pisharody, M Job, PK Berkvens, P Colomp, P TI Absorbed dose distributions in a tissue-equivalent absorber for bremsstrahlung produced at the beamlines of the European Synchrotron Radiation Facility SO RADIATION PHYSICS AND CHEMISTRY LA English DT Article DE bremsstrahlung absorbed dose ID ELECTRON STORAGE-RINGS; GAS BREMSSTRAHLUNG AB The absorbed-dose distributions for bremsstrahlung, incident on a tissue-equivalent phantom, were measured with LiF:Mg,Ti thermoluminescent dosimeters at two insertion device beamlines of the European Synchrotron Radiation Facility (ESRF). The measurements were carried out for two different electron beam energies of 4 and 6 GeV. The corresponding bremsstrahlung spectra and power were measured using a high-resolution lead glass total absorption calorimeter. The results are compared with similar measurements carried out at other facilities. The normalized bremsstrahlung absorbed dose in a cross-sectional area of 100 mm(2), at a depth of 150 mm of the phantom, was measured as 6.1 and 3.6 kGy h(-1) W-1 for the corresponding bremsstrahlung spectra of 4 and 6 GeV. (C) 2000 Elsevier Science Ltd. All rights reserved. C1 Argonne Natl Lab, Adv Photon Source, Argonne, IL 60439 USA. European Synchrotron Radiat Facil, F-38043 Grenoble, France. RP Job, PK (reprint author), Argonne Natl Lab, Adv Photon Source, 9700 S Cass Ave, Argonne, IL 60439 USA. NR 16 TC 4 Z9 4 U1 1 U2 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0969-806X J9 RADIAT PHYS CHEM JI Radiat. Phys. Chem. PD DEC PY 2000 VL 59 IS 5-6 BP 459 EP 466 DI 10.1016/S0969-806X(00)00311-X PG 8 WC Chemistry, Physical; Nuclear Science & Technology; Physics, Atomic, Molecular & Chemical SC Chemistry; Nuclear Science & Technology; Physics GA 374WU UT WOS:000165368000002 ER PT J AU Chien, A Maxwell, R Chambers, D Balazs, B LeMay, J AF Chien, A Maxwell, R Chambers, D Balazs, B LeMay, J TI Characterization of radiation-induced aging in silica-reinforced polysiloxane composites SO RADIATION PHYSICS AND CHEMISTRY LA English DT Article DE solvent swelling; polysiloxane; silica; gamma radiation; crosslink density determination; solid-state NMR ID IRRADIATION; ADSORPTION; SURFACES; RUBBER AB Changes in crosslink density and chemical structure of silica-reinforced silicone polymer composites due to aging in gamma radiation environments were examined in this study. Solvent swelling was utilized to determine the individual contributions of the matrix polymer and filler phase to the overall crosslink density of silica-reinforced silicone polymer composites. The results show how polymer-filler hydrogen bonding dominates the overall crosslink density of the material. Air-irradiated samples displayed decreased hydrogen bonding at the polymer-filler interface, while vacuum irradiation revealed the opposite effect. These results were supported by solid-state NMR experiments that correlated the motional dynamics of the polymer chains with crosslink density through T-2 relaxation time measurements. GC/MS analysis was used to identify degradation products formed as a result of irradiation and speculate upon likely degradation mechanisms. Published by Elsevier Science Ltd. C1 Univ Calif Lawrence Livermore Natl Lab, Chem & Mat Sci Directorate, Livermore, CA 94551 USA. RP Balazs, B (reprint author), Univ Calif Lawrence Livermore Natl Lab, Chem & Mat Sci Directorate, Livermore, CA 94551 USA. NR 24 TC 64 Z9 69 U1 1 U2 22 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0969-806X J9 RADIAT PHYS CHEM JI Radiat. Phys. Chem. PD DEC PY 2000 VL 59 IS 5-6 BP 493 EP 500 DI 10.1016/S0969-806X(00)00305-4 PG 8 WC Chemistry, Physical; Nuclear Science & Technology; Physics, Atomic, Molecular & Chemical SC Chemistry; Nuclear Science & Technology; Physics GA 374WU UT WOS:000165368000006 ER PT J AU Mohrenweiser, HW Jones, IM AF Mohrenweiser, HW Jones, IM TI Uncertainty of response to ionizing radiation due to genotype: Potential role for variation in DNA repair genes SO RADIATION RESEARCH LA English DT Meeting Abstract ID ATAXIA-TELANGIECTASIA; BREAST-CANCER; RISK; POLYMORPHISMS; ONSET C1 Univ Calif Lawrence Livermore Natl Lab, Biol & Biotechnol Res Program, Livermore, CA USA. FU NCI NIH HHS [P01 CA59431] NR 11 TC 5 Z9 5 U1 0 U2 0 PU RADIATION RESEARCH SOC PI OAK BROOK PA 2021 SPRING RD, STE 600, OAK BROOK, IL 60521 USA SN 0033-7587 J9 RADIAT RES JI Radiat. Res. PD DEC PY 2000 VL 154 IS 6 BP 722 EP 723 PG 2 WC Biology; Biophysics; Radiology, Nuclear Medicine & Medical Imaging SC Life Sciences & Biomedicine - Other Topics; Biophysics; Radiology, Nuclear Medicine & Medical Imaging GA 380MG UT WOS:000165705200024 PM 11187011 ER PT J AU Fry, RJM AF Fry, RJM TI Dose-rate effects and radiation protection SO RADIATION RESEARCH LA English DT Meeting Abstract C1 Oak Ridge Natl Lab, Div Life Sci, Oak Ridge, TN USA. NR 6 TC 1 Z9 1 U1 0 U2 0 PU RADIATION RESEARCH SOC PI OAK BROOK PA 2021 SPRING RD, STE 600, OAK BROOK, IL 60521 USA SN 0033-7587 J9 RADIAT RES JI Radiat. Res. PD DEC PY 2000 VL 154 IS 6 BP 735 EP 736 PG 2 WC Biology; Biophysics; Radiology, Nuclear Medicine & Medical Imaging SC Life Sciences & Biomedicine - Other Topics; Biophysics; Radiology, Nuclear Medicine & Medical Imaging GA 380MG UT WOS:000165705200039 PM 11187022 ER PT J AU Sheen, SH Chien, HT Raptis, AC AF Sheen, SH Chien, HT Raptis, AC TI Ultrasonic techniques for detecting helium leaks SO SENSORS AND ACTUATORS B-CHEMICAL LA English DT Article DE ultrasonics; SAW; helium leak; leak detection ID SENSOR; SAW AB We have examined two ultrasonic techniques for their applications in helium leak detectors. In one technique, a surface acoustic wave (SAW) device is used to detect helium gas through changes of thermal conductivity in helium/air mixtures. The second technique measures variations of sound Speed (SS) in such mixtures. Sensitivities and detection limits of both techniques were predicted with simple models and verified by measurements;The SAW sensor and the SS techniques can detect helium leaks as small as 10(-4) and 10(-5) cm(3)/s, respectively. Published by Elsevier Science B.V. C1 Argonne Natl Lab, Div Energy Technol, Argonne, IL 60439 USA. RP Sheen, SH (reprint author), Argonne Natl Lab, Div Energy Technol, 9700 S Cass Ave, Argonne, IL 60439 USA. NR 8 TC 6 Z9 7 U1 3 U2 5 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0925-4005 J9 SENSOR ACTUAT B-CHEM JI Sens. Actuator B-Chem. PD DEC 1 PY 2000 VL 71 IS 3 BP 197 EP 202 DI 10.1016/S0925-4005(00)00616-X PG 6 WC Chemistry, Analytical; Electrochemistry; Instruments & Instrumentation SC Chemistry; Electrochemistry; Instruments & Instrumentation GA 383RX UT WOS:000165897600008 ER PT J AU LaRoche, JR Ren, F Temple, D Pearton, SJ Kuo, JM Baca, AG Cheng, P Park, YD Hudspeth, Q Hebard, AF Arnason, SB AF LaRoche, JR Ren, F Temple, D Pearton, SJ Kuo, JM Baca, AG Cheng, P Park, YD Hudspeth, Q Hebard, AF Arnason, SB TI Processing techniques for InGaAs/InAlAs/InGaAs spin field effect transistors SO SOLID-STATE ELECTRONICS LA English DT Article ID INJECTION AB Wet etch processing techniques For InGaAs/Inal/As/InGaAs transistors are used to Fabricate an N-channel HEMT (High Electron Mobility Transistor) with Fe contacts. These processing techniques can easily be extended for dilute magnetic semiconductor regrowth and for testing of various spin injection geometries. (C) 2000 Elsevier Science Ltd, All rights reserved, C1 Univ Florida, Dept Chem Engn, Gainesville, FL 32611 USA. MCNC, Res Triangle Pk, NC 27709 USA. Univ Florida, Dept Mat Sci & Engn, Gainesville, FL 32611 USA. Bell Labs, Lucent Technol, Murray Hill, NJ 07974 USA. Sandia Natl Lab, Albuquerque, NM 87185 USA. USN, Res Lab, Washington, DC 20375 USA. Univ Florida, Dept Phys, Gainesville, FL 32611 USA. RP Ren, F (reprint author), Univ Florida, Dept Chem Engn, Gainesville, FL 32611 USA. RI Park, Yun/A-9559-2008 OI Park, Yun/0000-0001-7699-0432 NR 12 TC 1 Z9 1 U1 0 U2 4 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 DEC PY 2000 VL 44 IS 12 BP 2117 EP 2122 DI 10.1016/S0038-1101(00)00143-X PG 6 WC Engineering, Electrical & Electronic; Physics, Applied; Physics, Condensed Matter SC Engineering; Physics GA 396YP UT WOS:000166666000004 ER PT J AU Takeuchi, K Loong, CK Richardson, JW Guan, J Dorris, SE Balachandran, U AF Takeuchi, K Loong, CK Richardson, JW Guan, J Dorris, SE Balachandran, U TI The crystal structures and phase transitions in Y-doped BaCeO3: their dependence on Y concentration and hydrogen doping SO SOLID STATE IONICS LA English DT Article DE yttrium-doped barium cerate; mixed ionic and electronic conductors; proton conductors; hydrogen-separation membrane; neutron powder diffraction ID TEMPERATURE FUEL-CELLS; BARIUM CERATE; RAMAN-SCATTERING; PROTON CONDUCTIVITY; SOLID ELECTROLYTES; SRCEO3; PEROVSKITES; CONDUCTORS; OXIDES; NONSTOICHIOMETRY AB The crystal structures and phase transitions in BaCe1-xYxO3-delta (O less than or equal to x less than or equal to 0.3) that occur in response to heat treatment in oxidizing, reducing, and water-vapor-containing atmospheres were determined by neutron powder diffraction at room temperature. Single-phase BaCe1-xYxO3-delta (delta congruent tox/2) can be synthesized by O-2-annealing samples prepared by a solid-state reaction method, wherein they crystallize into perovskite-type structures (orthorhombic Pmcn for x less than or equal to 0.1 and rhombohedral R (3) over barc for x greater than or equal to 0.15), Within the composition range of 0.15 less than or equal to x less than or equal to 0.25, where maximum total conductivity is observed, the rhombohedral structure converts partially to a monoclinic 12/m structure upon exposure to water- or H-2-containing atmospheres (including laboratory air) at elevated temperatures. This study may suggest a correlation between the crystal structures, particularly the 12/m phase, and the proton transport properties, (C) 2000 Elsevier Science B.V. All rights reserved. C1 Argonne Natl Lab, Div Intense Pulsed Neutron Source, Argonne, IL 60439 USA. Argonne Natl Lab, Div Energy Technol, Argonne, IL 60439 USA. RP Loong, CK (reprint author), Argonne Natl Lab, Div Intense Pulsed Neutron Source, 9700 S Cass Ave, Argonne, IL 60439 USA. NR 38 TC 89 Z9 90 U1 2 U2 42 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0167-2738 J9 SOLID STATE IONICS JI Solid State Ion. PD DEC PY 2000 VL 138 IS 1-2 BP 63 EP 77 DI 10.1016/S0167-2738(00)00771-2 PG 15 WC Chemistry, Physical; Physics, Condensed Matter SC Chemistry; Physics GA 394PK UT WOS:000166532300006 ER PT J AU Dake, LS King, DE Czanderna, AW AF Dake, LS King, DE Czanderna, AW TI Ion scattering and X-ray photoelectron spectroscopy of copper overlayers vacuum deposited onto mercaptohexadecanoic acid self-assembled monolayers SO SOLID STATE SCIENCES LA English DT Article DE self-assembled monolayers, metal; organic interfaces; Cu interactions with COOH, penetration of Cu through self-assembled monolayers, XPS and ISS of Cu; HOOC interfaces, surface ID ORGANIZED MOLECULAR ASSEMBLIES; METAL OVERLAYERS; FUNCTIONAL-GROUPS; PENETRATION; INTERFACES AB Metal overlayers deposited in vacuum onto self-assembled monolayer (SAM) systems serve as models for more complex metalized polymers. Metals (M) deposited onto SAMs with different organic functional end groups exhibit a wide range of behavior, ranging from strong chemical interactions with the end group to complete penetration of the metal through the SAM. In this work, we have characterized the interactions of Cu with the -COOH of mercaptohexadecanoic acid (MHA, HOOC(CH2)(15)SH) SAMs self assembled on gold films by using X-ray photoelectron spectroscopy (ISS) to examine the chemical interactions, and a combination of XPS and ion scattering spectroscopy (ISS) to deduce the growth mode and penetration rate of the deposited Cu. We found that submonolayer amounts of Cu react with HOOC, whereas the rest of the Cu remains metallic and penetrates beneath the SAM surface to the SAM [Au interface. Considerable amounts of Cu (5 nm or more) will penetrate beneath the SAM layer, which is ca. 2.5 nm thick, despite the submonolayer presence of Cu at the SAM surface. The penetration rate depends strongly on the Cu deposition rate. Depositing copper onto MHA at 220 K or less, or using faster Cu deposition rates, results in slower or even completely suppressed penetration of the Cu through the SAM layer, whereas exposure to X-rays greatly enhances the penetration rate of large amounts of Cu through the SAM layer. The reacted copper is, based on the XPS 2p and LMM peaks, in the +2 oxidation state, but cannot be identified with a simple, stoichiometric oxide such as Cu2O, CuO, or Cu (OH)(2). (C) 2000 Editions scientifiques et medicales Elsevier SAS. All rights reserved. C1 Natl Renewable Energy Lab, Golden, CO 80401 USA. RP Dake, LS (reprint author), POB 27209, Denver, CO 80227 USA. NR 25 TC 36 Z9 37 U1 0 U2 8 PU EDITIONS SCIENTIFIQUES MEDICALES ELSEVIER PI PARIS CEDEX 15 PA 23 RUE LINOIS, 75724 PARIS CEDEX 15, FRANCE SN 1293-2558 J9 SOLID STATE SCI JI Solid State Sci. PD DEC PY 2000 VL 2 IS 8 BP 781 EP 789 DI 10.1016/S1293-2558(00)01095-5 PG 9 WC Chemistry, Inorganic & Nuclear; Chemistry, Physical; Physics, Condensed Matter SC Chemistry; Physics GA 392RQ UT WOS:000166425900008 ER PT J AU Salazar, MR Kress, JD Redondo, A AF Salazar, MR Kress, JD Redondo, A TI Dissociation of molecular oxygen on unpromoted and cesium promoted Ag(110) surfaces SO SURFACE SCIENCE LA English DT Article DE catalysis; chemisorption; density functional calculations; oxygen; silver ID EFFECTIVE CORE POTENTIALS; ETHYLENE EPOXIDATION; ADSORPTION; DENSITY; CHEMISTRY; CATALYST; SILVER; O-2 AB We have computed the binding energies for the molecular and atomic chemisorbed states of oxygen, and barriers between them, for a three-layer model cluster representative of the (110) face of silver as a function of cesium coverage. To increase computational efficiency, a one-electron potential was developed for the third layer of the silver atoms making up the model cluster. These calculations predict a barrier of similar to 17 kcal/mol to dissociate chemisorbed O-2, in good agreement with experiment. When a Cs atom is added to the cluster, the barrier for O-2 dissociation is significantly lowered. However, when two Cs atoms were added the barrier for dissociation increased relative to the barrier for the cluster with one adsorbed Cs atom. These calculations predict that the dissociation of chemisorbed molecular oxygen will have a Cs coverage dependence. This dissociation pattern is consistent with prior calculations on Ag(111) model clusters. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Univ Calif Los Alamos Natl Lab, Div Theoret, Grp T12, Los Alamos, NM 87545 USA. RP Salazar, MR (reprint author), Univ Calif Los Alamos Natl Lab, Div Theoret, Grp T12, Los Alamos, NM 87545 USA. NR 32 TC 8 Z9 8 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0039-6028 J9 SURF SCI JI Surf. Sci. PD DEC 1 PY 2000 VL 469 IS 1 BP 80 EP 90 DI 10.1016/S0039-6028(00)00796-2 PG 11 WC Chemistry, Physical; Physics, Condensed Matter SC Chemistry; Physics GA 383NP UT WOS:000165889100009 ER PT J AU Brown, J AF Brown, J TI Broadcasting freedom: The Cold War triumph of radio free Europe and radio liberty SO SURVIVAL LA English DT Book Review C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Brown, J (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. NR 1 TC 0 Z9 0 U1 0 U2 0 PU OXFORD UNIV PRESS PI OXFORD PA GREAT CLARENDON ST, OXFORD OX2 6DP, ENGLAND SN 0039-6338 J9 SURVIVAL JI Survival PD WIN PY 2000 VL 42 IS 4 BP 171 EP 172 PG 2 WC International Relations; Political Science SC International Relations; Government & Law GA 379QT UT WOS:000165654500017 ER PT J AU Androsch, R Wunderlich, B AF Androsch, R Wunderlich, B TI Reversing melting and crystallization of indium as a function of temperature modulation SO THERMOCHIMICA ACTA LA English DT Article DE melting; crystallization; indium; DSC; TMDSC ID DIFFERENTIAL SCANNING CALORIMETRY; FIRST-ORDER TRANSITIONS; X-RAY-SCATTERING; DSC; POLYETHYLENE AB The melting and crystallization of indium has been reinvestigated with the heater-controlled Mettler-Toledo differential scanning calorimeter DSC 820. The heat-flow rate during melting and crystallization is largely determined by instrumental characteristics and often does not permit the evaluation of kinetic parameters of the phase transition. We found that the observed reversing character of the melting depends strongly on the modulation parameters. For quasi-isothermal, temperature-modulated calorimetry with a symmetric sawtooth, the degree of reversibility decreases with increasing amplitude of temperature modulation. At a lower average temperature of modulation relative to the melting temperature, the partial melting process can be fully reversing, while at higher average temperatures, the melting becomes less reversing due to instrumental time restrictions for the completion of melting. With an appropriately modified, nonsymmetric sawtooth, however, the phase transition can be made fully reversing, even in the later stages of the melting process (as long as crystal nuclei remain). The influence of sample mass, sample position within the pan, and type of pan are analyzed, and the conditions for the study of the kinetics of crystallization of nucleated crystals close to the melting temperature, and by implication, also the melting kinetics, are suggested. Published by Elsevier Science B.V. C1 Univ Halle Wittenberg, Inst Sci Mat, D-06217 Merseburg, Germany. Univ Tennessee, Dept Chem, Knoxville, TN 37996 USA. Oak Ridge Natl Lab, Div Chem & Analyt Sci, Oak Ridge, TN 37831 USA. RP Wunderlich, B (reprint author), Univ Tennessee, Dept Chem, Knoxville, TN 37996 USA. NR 24 TC 12 Z9 12 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0040-6031 J9 THERMOCHIM ACTA JI Thermochim. Acta PD DEC 1 PY 2000 VL 364 IS 1-2 BP 181 EP 191 DI 10.1016/S0040-6031(00)00644-4 PG 11 WC Thermodynamics; Chemistry, Analytical; Chemistry, Physical SC Thermodynamics; Chemistry GA 381VA UT WOS:000165783100017 ER PT J AU Bozlee, BJ Exarhos, GJ AF Bozlee, BJ Exarhos, GJ TI Preparation and characterization of gold and ruthenium colloids in thin zinc oxide films SO THIN SOLID FILMS LA English DT Article; Proceedings Paper CT 27th International Conference on Metallurgical Coatings and Thin Films CY APR 10-14, 2000 CL SAN DIEGO, CALIFORNIA SP Amer Vacuum Soc, Adv Surface Engn Div DE colloid; gold; mie theory; nanoparticle; Raman; SERS; ZnO ID OPTICAL-PROPERTIES; ZNO FILMS; SPECTROSCOPY AB Gold and Ruthenium colloids have been introduced into thin films of ZnO by spin coating metal ion-doped solutions of zinc acetylacetonate onto quartz or Pt substrates, followed by heating to 400 degreesC. Both types of him exhibit a blue tint due to Mie light absorption of the metal nanoparticles. Analysis of the visible absorption spectra suggests particle radii on the order of 2 nm. However, electron micrographs reveal some larger particles and particle aggregates as well. While the Au colloid absorption band peaks at approximately 575 nm, Raman excitation profiles of the colloidal films exhibit red-shifted maxima near 700 nm. We attribute the striking Raman intensity enhancement at an excitation wavelength of similar to 700 nm to Surface-enhanced Raman (SER) scattering of the E-1 mode of ZnO. Ru colloids also induce SER scattering from a residual RuO2 layer that apparently coats the Ru metal particle. In this case, the SER scattering is greatest when the laser excitation is tuned into the maximum of the Ru colloid absorption band, in accord with the so-called electromagnetic theory of SER scattering. While not all of the Ru in Ru-doped films is prepared in the zero oxidation state, XPS measurements show that all of the gold in the gold-doped films is in the zero oxidation state. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Univ Great Falls, Great Falls, MT 59405 USA. Pacific NW Natl Lab, Richland, WA 99352 USA. RP Exarhos, GJ (reprint author), Univ Great Falls, Great Falls, MT 59405 USA. NR 17 TC 13 Z9 15 U1 5 U2 21 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 DEC 1 PY 2000 VL 377 BP 1 EP 7 DI 10.1016/S0040-6090(00)01377-8 PG 7 WC Materials Science, Multidisciplinary; Materials Science, Coatings & Films; Physics, Applied; Physics, Condensed Matter SC Materials Science; Physics GA 385VD UT WOS:000166024600002 ER PT J AU Jellison, GE Merkulov, VI Puretzky, AA Geohegan, DB Eres, G Lowndes, DH Caughman, JB AF Jellison, GE Merkulov, VI Puretzky, AA Geohegan, DB Eres, G Lowndes, DH Caughman, JB TI Characterization of thin-film amorphous semiconductors using spectroscopic ellipsometry SO THIN SOLID FILMS LA English DT Article; Proceedings Paper CT 27th International Conference on Metallurgical Coatings and Thin Films CY APR 10-14, 2000 CL SAN DIEGO, CALIFORNIA SP Amer Vacuum Soc, Adv Surface Engn Div ID 2-MODULATOR GENERALIZED ELLIPSOMETRY; OPTICAL DISPERSION-RELATIONS; DIAMOND FILMS AB Spectroscopic ellipsometry (SE) has been used to routinely characterize amorphous silicon nitride and diamond thin films. Since SE measurements do not yield quantities of interest directly, the SE data must first be fit to a model to obtain useful parameters such as film thickness and optical functions. The Tauc-Lorentz (TL) model for the optical functions of amorphous materials [Appl. Phys. Lett. 69, 371/373, 2137 (1996)] has been shown to be very useful in interpreting these SE results. A four-parameter model is usually sufficient to describe the optical functions of the thin film to the accuracy of the ellipsometer. One of these parameters, the band gap E-g, correlates with other mechanical and chemical properties of the film, such as the silicon-to-nitrogen ratio in silicon nitride films, and to the sp(3)-bonded carbon fraction and the hardness of amorphous carbon films. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Oak Ridge Natl Lab, Div Solid State, Oak Ridge, TN 37831 USA. Oak Ridge Natl Lab, Div Fus Energy, Oak Ridge, TN 37831 USA. RP Jellison, GE (reprint author), Oak Ridge Natl Lab, Div Solid State, Oak Ridge, TN 37831 USA. RI Puretzky, Alexander/B-5567-2016; Geohegan, David/D-3599-2013; Eres, Gyula/C-4656-2017 OI Puretzky, Alexander/0000-0002-9996-4429; Geohegan, David/0000-0003-0273-3139; Eres, Gyula/0000-0003-2690-5214 NR 21 TC 94 Z9 95 U1 3 U2 22 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 DEC 1 PY 2000 VL 377 BP 68 EP 73 DI 10.1016/S0040-6090(00)01384-5 PG 6 WC Materials Science, Multidisciplinary; Materials Science, Coatings & Films; Physics, Applied; Physics, Condensed Matter SC Materials Science; Physics GA 385VD UT WOS:000166024600013 ER PT J AU Meng, WJ Tittsworth, RC Rehn, LE AF Meng, WJ Tittsworth, RC Rehn, LE TI Mechanical properties and microstructure of TiC/amorphous hydrocarbon nanocomposite coatings SO THIN SOLID FILMS LA English DT Article; Proceedings Paper CT 27th International Conference on Metallurgical Coatings and Thin Films CY APR 10-14, 2000 CL SAN DIEGO, CALIFORNIA SP Amer Vacuum Soc, Adv Surface Engn Div DE nanocomposite; microstructure; mechanical property ID MULTIPLE-SCATTERING CALCULATIONS; PHYSICAL VAPOR-DEPOSITION; ABSORPTION FINE-STRUCTURE; CARBON COATINGS; ASSISTED DEPOSITION; CONTACT FATIGUE; THIN-FILMS; STRESS AB Using the techniques of reactive magnetron sputter deposition and inductively coupled plasma (ICP) assisted hybrid physical vapor deposition (PVD)/chemical vapor deposition (CVD), we have synthesized a wide variety of metal-free amorphous hydrocarbon (a-C:H) and Ti-containing hydrocarbon (Ti-C:H) coatings. Coating elastic modulus and hardness have been measured by the technique of instrumented nanoindentation and related to Ti and hydrogen compositions. We show that both metal and hydrogen compositions significantly influence the mechanical properties of Ti-C:H coatings. The microstructure of Ti-C:H coatings is further characterized by transmission electron microscopy (TEM), X-ray absorption near edge structure (XANES) spectroscopy, and extended X-ray absorption fine structure (EXAFS) spectroscopy. XANES spectroscopy and high-resolution TEM examination of Ti-C:H specimens shows that the dissolution limit of Ti atoms in an a-C:H matrix is between 0.9 and 2.5 at.%. Beyond the Ti dissolution limit, precipitation of nanocrystalline Bi-TiC cluster occurs and Ti-C:H coatings are in fact TiC/a-C:H thin film nanocomposites. Measurements of the average Ti bonding environment in TiC/a-C:H nanocomposites by EXAFS spectroscopy are consistent with a microstructure in which bulk-like Bi-TiC clusters are embedded in an a-C:H matrix. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Louisiana State Univ, Dept Mech Engn, Baton Rouge, LA 70803 USA. Louisiana State Univ, Ctr Adv Microstruct & Devices, Baton Rouge, LA 70803 USA. Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. RP Meng, WJ (reprint author), Louisiana State Univ, Dept Mech Engn, Baton Rouge, LA 70803 USA. NR 29 TC 53 Z9 55 U1 2 U2 7 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 DEC 1 PY 2000 VL 377 BP 222 EP 232 DI 10.1016/S0040-6090(00)01300-6 PG 11 WC Materials Science, Multidisciplinary; Materials Science, Coatings & Films; Physics, Applied; Physics, Condensed Matter SC Materials Science; Physics GA 385VD UT WOS:000166024600039 ER PT J AU Wang, JG Kim, HK Shi, FG Zhao, B Nieh, TG AF Wang, JG Kim, HK Shi, FG Zhao, B Nieh, TG TI Thickness dependence of morphology and mechanical properties of on-wafer low-k PTFE dielectric films SO THIN SOLID FILMS LA English DT Article; Proceedings Paper CT 27th International Conference on Metallurgical Coatings and Thin Films CY APR 10-14, 2000 CL SAN DIEGO, CA SP Amer Vacuum Soc, Adv Surface Engn Div DE surface morphology; polytetrafluoroethylene (PTFE); thickness dependence; nanoindentation ID FLUOROPOLYMER THIN-FILMS; PULSED-LASER DEPOSITION; POLYMER-FILMS; POLYTETRAFLUOROETHYLENE FILMS; FORCE MICROSCOPY; CRYSTALLIZATION; ABLATION; CRYSTALS; MELT AB The structure and morphology of on-wafer low-k ultrathin dielectric polytetrafluoroethylene (PTFE) films have been investigated using X-ray diffraction (XRD), polarized optical microscopy (POM) and scanning electron microscopy (SEM). The morphology observed by POM and SEM is found to be thickness-dependent; the characters of spherulite and lamella morphologies became mature gradually with increasing thickness. A similar thickness dependence of spherulitic and lamellar morphologies is found. The thickness-dependent Young's modulus and hardness obtained by the dynamic contact module (DCM) in a unique frequency-specific depth-sensing indentation can be explained by the observed thickness dependence of morphology. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Univ Calif Irvine, Dept Chem & Biochem Engn & Mat Sci, Irvine, CA 92697 USA. Conexant Syst Inc, Newport Beach, CA 92660 USA. Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. RP Wang, JG (reprint author), Penn State Univ, Mat Characterizat Lab, 194 Mat Res Inst Bldg, University Pk, PA 16802 USA. EM jqw11@psu.edu RI Nieh, Tai-Gang/G-5912-2011 OI Nieh, Tai-Gang/0000-0002-2814-3746 NR 36 TC 14 Z9 15 U1 2 U2 11 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 DEC 1 PY 2000 VL 377 BP 413 EP 417 DI 10.1016/S0040-6090(00)01434-6 PG 5 WC Materials Science, Multidisciplinary; Materials Science, Coatings & Films; Physics, Applied; Physics, Condensed Matter SC Materials Science; Physics GA 385VD UT WOS:000166024600070 ER PT J AU Ott, RD Ruby, C Huang, F Weaver, ML Barnard, JA AF Ott, RD Ruby, C Huang, F Weaver, ML Barnard, JA TI Nanotribology and surface chemistry of reactively sputtered Ti-B-N hard coatings SO THIN SOLID FILMS LA English DT Article; Proceedings Paper CT 27th International Conference on Metallurgical Coatings and Thin Films CY APR 10-14, 2000 CL SAN DIEGO, CALIFORNIA SP Amer Vacuum Soc, Adv Surface Engn Div DE nanoindentation; nanotribology; hard coatings; wear resistant coatings ID FILMS AB The nanotribological performance of Ti-B-N protective coatings, 500 nm thick, have been studied in the range of 0-38.5 at.% N. A correlation was established amongst the chemical state, structure, mechanical properties, and nanowear resistance as a function of atomic percent nitrogen. The mechanical properties, elastic modulus and hardness, of the films were tested using a Hysitron Triboscope nanomechanical test instrument. The nanotribological performance of the films was evaluated using a Nanoindenter II with scratch capability. Single and reciprocating nanowear scratches, 10 mum in length, were performed at normal loads ranging from 50 to 750 muN. An atomic force microscope (AFM) was utilized to characterize the nanowear tracks with respect to depth and amount of plowing of material. The AFM images revealed that the reciprocating nanowear test caused grooving of the films with little to no material removal. Chemical and structural information was obtained by X-ray photoelectron spectroscopy (XPS) and X-ray diffraction. Increasing N content correlated with increasing number of B-N bends, structural disorder, and decreasing hardness, modulus, and wear resistance. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Univ Alabama, Ctr Mat Informat Technol, Tuscaloosa, AL 35487 USA. RP Ott, RD (reprint author), Oak Ridge Natl Lab, POB 2008, Oak Ridge, TN 37831 USA. NR 13 TC 22 Z9 23 U1 2 U2 3 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 DEC 1 PY 2000 VL 377 BP 602 EP 606 DI 10.1016/S0040-6090(00)01274-8 PG 5 WC Materials Science, Multidisciplinary; Materials Science, Coatings & Films; Physics, Applied; Physics, Condensed Matter SC Materials Science; Physics GA 385VD UT WOS:000166024600102 ER PT J AU Riester, L Blau, PJ Lara-Curzio, E Breder, K AF Riester, L Blau, PJ Lara-Curzio, E Breder, K TI Nanoindentation with a Knoop indenter SO THIN SOLID FILMS LA English DT Article; Proceedings Paper CT 27th International Conference on Metallurgical Coatings and Thin Films CY APR 10-14, 2000 CL SAN DIEGO, CALIFORNIA SP Amer Vacuum Soc, Adv Surface Engn Div DE nanoindent; Knoop; mechanical properties ID ELASTIC-MODULUS; INDENTATION; LOAD AB Nanoindentation is a reliable method for measuring mechanical properties of thin films and small volumes of most materials. The Berkovich indenter is preferred for measurement of hardness and Young's modulus at the very low loads at which the Nanoindenter(TM) is capable of operating. For specialized tests, other tip geometries such as a Knoop indenter may be advantageous. This study concerns itself with the comparison of ultra low-load Knoop to Berkovich indents on 6061 aluminum, silicon, aluminum oxide, fused silica, nickel and silicon nitride. Values for material hardness obtained from the indentation loading and unloading history of silicon and 6061 aluminum from barstock were compared to values for hardness calculated by measuring the residual indenter impressions on scanning electron microscope images. Results based on measurements and characterization of residual indenter impressions indicate that the response of materials to Knoop indentation is comparable to other indenters. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. St Gobain Abras, Worcester, MA 01615 USA. RP Riester, L (reprint author), Oak Ridge Natl Lab, POB 2008, Oak Ridge, TN 37831 USA. NR 11 TC 14 Z9 14 U1 1 U2 4 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 DEC 1 PY 2000 VL 377 BP 635 EP 639 DI 10.1016/S0040-6090(00)01298-0 PG 5 WC Materials Science, Multidisciplinary; Materials Science, Coatings & Films; Physics, Applied; Physics, Condensed Matter SC Materials Science; Physics GA 385VD UT WOS:000166024600109 ER PT J AU Jankowski, AF AF Jankowski, AF TI Superlattice effects on the amorphization of Ni-Ti multilayers SO THIN SOLID FILMS LA English DT Article; Proceedings Paper CT 27th International Conference on Metallurgical Coatings and Thin Films CY APR 10-14, 2000 CL SAN DIEGO, CALIFORNIA SP Amer Vacuum Soc, Adv Surface Engn Div DE superlattice; multilayer; Ni-Ti; solid-state amorphization ID SOLID-STATE AMORPHIZATION; CENTERED-CUBIC TITANIUM; NI/TI MULTILAYERS; CALORIMETRY AB A phenomenological model is proposed to correlate the onset of solid-state amorphization with the loss of interfacial stability in Ni-Ti multilayers. Additionally, temperature dependence to the onset of amorphization is attributed to the effect of interfacial coherency that varies with the Ni-Ti layer pair spacing. A decrease in the amorphization temperature occurs as lattice coherency is lost with an increase in the layer pair spacing. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. RP Jankowski, AF (reprint author), Univ Calif Lawrence Livermore Natl Lab, POB 808,MS L-352, Livermore, CA 94551 USA. NR 11 TC 1 Z9 1 U1 0 U2 1 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 DEC 1 PY 2000 VL 377 BP 646 EP 649 DI 10.1016/S0040-6090(00)01281-5 PG 4 WC Materials Science, Multidisciplinary; Materials Science, Coatings & Films; Physics, Applied; Physics, Condensed Matter SC Materials Science; Physics GA 385VD UT WOS:000166024600111 ER PT J AU Tuan, A Yoon, M Medvedev, V Ono, Y Ma, Y Rogers, JW AF Tuan, A Yoon, M Medvedev, V Ono, Y Ma, Y Rogers, JW TI Interface control in the chemical vapor deposition of titanium dioxide on silicon(100) SO THIN SOLID FILMS LA English DT Article; Proceedings Paper CT 27th International Conference on Metallurgical Coatings and Thin Films CY APR 10-14, 2000 CL SAN DIEGO, CALIFORNIA SP Amer Vacuum Soc, Adv Surface Engn Div DE titanium dioxide; high-k dielectric; chemical vapour deposition (CVD) ID DIELECTRIC FILMS; TIO2 FILMS; DEGRADATION AB A novel deposition sequence has been developed for the growth of carbon-free, amorphous titanium dioxide thin films on p-type Si(100) using titanium tetrakis-isopropoxide (TTIP) as the metalorganic precursor. The deposition process occurs in an ultra-high vacuum chamber and consists of three stages. Initially, a continuous layer of titanium was deposited on silicon at a substrate temperature of 650 K using a Ti sublimator. The substrate temperature was then lowered to 300 K and the titanium layer was oxidized using a gas phase oxygen source to form a TiOx buffer layer. Subsequently, a TiO2 thin film was deposited by MOCVD using TTIP at low temperature (below 650 K). Auger electron spectroscopy (AES) performed at each stage of growth showed no detectable carbon contamination. Additional AES measurements suggest that at the process temperature, titanium grows on silicon according to the Stranski-Krastanov mode, which permits the uniform growth of the titanium layer. Finally, X-ray diffraction (XRD) studies show that the thermal decomposition of TTIP produces amorphous TiO2 at 650 K. This unique process allows for the production of a high-quality amorphous titanium dioxide thin film without interfacial carbon contamination. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Pacific NW Natl Lab, Environm Mol Sci Lab, Richland, WA 99352 USA. Univ Washington, Dept Chem Engn, Seattle, WA 98195 USA. Univ Washington, Dept Mat Sci & Engn, Seattle, WA 98195 USA. Sharp Labs Amer, Camas, WA 98607 USA. RP Rogers, JW (reprint author), Pacific NW Natl Lab, Environm Mol Sci Lab, POB 999, Richland, WA 99352 USA. NR 16 TC 15 Z9 16 U1 1 U2 5 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 DEC 1 PY 2000 VL 377 BP 766 EP 771 DI 10.1016/S0040-6090(00)01453-X PG 6 WC Materials Science, Multidisciplinary; Materials Science, Coatings & Films; Physics, Applied; Physics, Condensed Matter SC Materials Science; Physics GA 385VD UT WOS:000166024600130 ER PT J AU Studier, FW AF Studier, FW TI Slab-gel electrophoresis SO TRENDS IN BIOCHEMICAL SCIENCES LA English DT Review ID RESTRICTION ENDONUCLEASE; HEMOPHILUS-INFLUENZAE; BACTERIOPHAGE-T7 DNA; T7; CLEAVAGE; PROTEINS; FRAGMENTS; SEQUENCES C1 Brookhaven Natl Lab, Dept Biol, Upton, NY 11973 USA. RP Studier, FW (reprint author), Brookhaven Natl Lab, Dept Biol, Upton, NY 11973 USA. NR 22 TC 7 Z9 7 U1 1 U2 3 PU ELSEVIER SCIENCE LONDON PI LONDON PA 84 THEOBALDS RD, LONDON WC1X 8RR, ENGLAND SN 0968-0004 J9 TRENDS BIOCHEM SCI JI Trends Biochem.Sci. PD DEC PY 2000 VL 25 IS 12 BP 588 EP 590 DI 10.1016/S0968-0004(00)01679-0 PG 3 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA 394GN UT WOS:000166515800007 PM 11116182 ER PT J AU Ghirardi, ML Zhang, JP Lee, JW Flynn, T Seibert, M Greenbaum, E Melis, A AF Ghirardi, ML Zhang, JP Lee, JW Flynn, T Seibert, M Greenbaum, E Melis, A TI Microalgae: a green source of renewable H-2 SO TRENDS IN BIOTECHNOLOGY LA English DT Review ID PHOTOSYNTHETIC ELECTRON-TRANSPORT; CHLAMYDOMONAS-REINHARDTII; FERMENTATIVE METABOLISM; HYDROGEN METABOLISM; CYANOBACTERIUM; NITROGENASE; EVOLUTION; PROTEIN AB This article summarizes recent advances in the field of algal hydrogen production. Two fundamental approaches are being developed. One involves the temporal separation of the usually incompatible reactions of O-2 and H-2 production in green algae, and the second involves the use of classical genetics to increase the O-2 tolerance of the reversible hydrogenase enzyme. The economic and environmental impact of a renewable source of H-2 are also discussed. C1 Natl Renewable Energy Lab, Golden, CO 80401 USA. Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Ghirardi, ML (reprint author), Natl Renewable Energy Lab, Golden, CO 80401 USA. RI Ducey, Thomas/A-6493-2011 NR 39 TC 327 Z9 348 U1 3 U2 73 PU ELSEVIER SCIENCE LONDON PI LONDON PA 84 THEOBALDS RD, LONDON WC1X 8RR, ENGLAND SN 0167-7799 J9 TRENDS BIOTECHNOL JI Trends Biotechnol. PD DEC PY 2000 VL 18 IS 12 BP 506 EP 511 DI 10.1016/S0167-7799(00)01511-0 PG 8 WC Biotechnology & Applied Microbiology SC Biotechnology & Applied Microbiology GA 401CM UT WOS:000166909500007 PM 11102662 ER PT J AU Vasco, DW Keers, H Karasaki, K AF Vasco, DW Keers, H Karasaki, K TI Estimation of reservoir properties using transient pressure data: An asymptotic approach SO WATER RESOURCES RESEARCH LA English DT Article ID INVERSE PROBLEM; POROUS-MEDIA; FLOW AB An asymptotic formulation of the inverse problem for flow reveals that the inversion may be partitioned into two complementary subproblems. In the first problem the arrival time associated with the peak slope of the transient curve is directly related to reservoir properties. The second inverse problem is similar to current methods for. interpreting flow data; the transient head amplitudes are related to reservoir storage and conductivity. The first subproblem,,the arrival time inversion, involves much less computation than does amplitude matching. Furthermore, it appears to be more robust with respect to the starting model. Therefore the solution to the arrival time inversion provides a starting model for amplitude matching. The methodology is particularly suited to the analysis of observations from well tests. We apply the approach to observations from two interference tests conducted at the Borehole Test Facility in Oklahoma. Using the transient pressure measurements, we image a shallow conductive fracture. The existence and location of the fracture has been verified by both geophysical and borehole data. In particular, core from a slant well contains an open, vertical fracture which coincides with our conductive feature. C1 Lawrence Berkeley Lab, Div Earth Sci, Berkeley, CA 94720 USA. RP Vasco, DW (reprint author), Lawrence Berkeley Lab, Div Earth Sci, Bldg 90,1 Cyclotron Rd, Berkeley, CA 94720 USA. RI Vasco, Donald/I-3167-2016 OI Vasco, Donald/0000-0003-1210-8628 NR 43 TC 93 Z9 94 U1 3 U2 14 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 DEC PY 2000 VL 36 IS 12 BP 3447 EP 3465 DI 10.1029/2000WR900179 PG 19 WC Environmental Sciences; Limnology; Water Resources SC Environmental Sciences & Ecology; Marine & Freshwater Biology; Water Resources GA 382BT UT WOS:000165799100005 ER PT J AU Haggerty, R McKenna, SA Meigs, LC AF Haggerty, R McKenna, SA Meigs, LC TI On the late-time behavior of tracer test breakthrough curves SO WATER RESOURCES RESEARCH LA English DT Article ID AGGREGATED POROUS-MEDIA; HETEROGENEOUS SORPTION PROCESSES; PORE-SCALE HETEROGENEITY; MASS-TRANSFER; SOLUTE TRANSPORT; SIZE DISTRIBUTION; NONEQUILIBRIUM SORPTION; DESORPTION-KINETICS; ASYMPTOTIC ANALYSIS; SUBSURFACE SYSTEMS AB We investigated the late-time (asymptotic) behavior of tracer test breakthrough curves (BTCs) with rate-limited mass transfer (e.g., in dual-porosity or multiporosity systems) and found that the late-time concentration c is given by the simple expression c = t(ad){(c(0)g - [m(0)(partial derivativeg/partial derivativet)]}, for t much greater than t(ad) and t(alpha) much greater than t(ad), where t(ad) is the advection time, co is the initial concentration in the medium, mo is the zeroth moment of the injection pulse, and t, is the mean residence time in the immobile domain (i.e., the characteristic mass transfer time). The function g is proportional to the residence time distribution in the immobile domain; we tabulate g for many geometries, including several distributed (multirate) models of mass transfer. Using this expression, we examine the behavior of late-time concentration for a number of mass transfer models. One key result is that if rate-limited mass transfer causes the ETC to behave as a power law at late time (i.e., c similar to t(-k)), then the underlying density function of rate coefficients must also be a power law with the form alpha (k-3) as alpha --> 0. This is true for both density functions of first-order and diffusion rate coefficients. BTCs with k < 3 persisting to the end of the experiment indicate a mean residence time longer than the experiment, and possibly an infinite residence time, and also suggest an effective rate coefficient that is either undefined or changes as a function of observation time. We apply our analysis to breakthrough curves from single-well injection-withdrawal tests at the Waste Isolation Pilot Plant, New Mexico. C1 Oregon State Univ, Dept Geosci, Corvallis, OR 97331 USA. Sandia Natl Labs, Geohydrol Dept, Albuquerque, NM 87185 USA. RP Haggerty, R (reprint author), Oregon State Univ, Dept Geosci, Corvallis, OR 97331 USA. RI Haggerty, Roy/A-5863-2009 NR 59 TC 246 Z9 248 U1 4 U2 47 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 DEC PY 2000 VL 36 IS 12 BP 3467 EP 3479 DI 10.1029/2000WR900214 PG 13 WC Environmental Sciences; Limnology; Water Resources SC Environmental Sciences & Ecology; Marine & Freshwater Biology; Water Resources GA 382BT UT WOS:000165799100006 ER PT J AU Faybishenko, B Doughty, C Steiger, M Long, JCS Wood, TR Jacobsen, JS Lore, J Zawislanski, PT AF Faybishenko, B Doughty, C Steiger, M Long, JCS Wood, TR Jacobsen, JS Lore, J Zawislanski, PT TI Conceptual model of the geometry and physics of water flow a fractured basalt vadose zone SO WATER RESOURCES RESEARCH LA English DT Article ID THICK UNSATURATED ZONES; SOLUTE TRANSPORT; SATURATED SOILS; ROCK FRACTURES; POROUS-MEDIA; PERMEABILITY; INSTABILITY; SEEPAGE; AQUIFER; CHALK AB conceptual model of the geometry and physics of water flow in a fractured basalt vadose zone was developed based on the results of lithological studies and a series of ponded infiltration tests conducted at the Box Canyon site near the Idaho National Engineering and Environmental Laboratory. The infiltration tests included one 2-week test in 1996, three 2-day tests in 1997, and one 4-day test in 1997. For the various tests, initial infiltration rates ranged from 4.1 cm/d (4.75 x 10(-7) m/s) to 17.7 cm/d (2.05 x 10(-7) m/s) and then decreased with time, presumably because of mechanical or microbiological clogging of fractures and vesicular basalt in the near-surface zone, as well as the effect of entrapped air. The subsurface moisture redistribution was monitored with tensiometers, neutron logging, time domain reflectrometry, and ground-penetrating radar. A conservative tracer, potassium bromide, was added to the pond water at a concentration of 3 g/L to monitor water flow with electrical resistivity probes and water sampling. Analysis of the data shows evidence of preferential flow rather than the propagation of a uniform wetting front. We propose a conceptual model describing the saturation-desaturation behavior of the basalt, in which rapid preferential flow occurs through the largest vertical fractures, followed by a gradual wetting of other fractures and the basalt matrix. Fractures that are saturated early in the tests may become desaturated thereafter, which we attribute to the redistribution of water between fractures and matrix. Lateral movement of water takes place within horizontal fracture and rubble zones, enabling development of perched water bodies. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Div Earth Sci, Berkeley, CA 94720 USA. Univ Nevada, Mackay Sch Mines, Reno, NV 89557 USA. Idaho Natl Engn & Environm Lab, Idaho Falls, ID 83415 USA. Stanford Univ, Dept Geol & Environm Sci, Stanford, CA 94305 USA. RP Faybishenko, B (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Div Earth Sci, 1 Cyclotron Rd,MS 90-1116, Berkeley, CA 94720 USA. RI Doughty, Christine/G-2389-2015; Faybishenko, Boris/G-3363-2015 OI Faybishenko, Boris/0000-0003-0085-8499 NR 56 TC 47 Z9 47 U1 4 U2 17 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 DEC PY 2000 VL 36 IS 12 BP 3499 EP 3520 DI 10.1029/2000WR900144 PG 22 WC Environmental Sciences; Limnology; Water Resources SC Environmental Sciences & Ecology; Marine & Freshwater Biology; Water Resources GA 382BT UT WOS:000165799100008 ER PT J AU Doughty, C AF Doughty, C TI Numerical model of water flow in a fractured basalt vadose zone: Box Canyon site, Idaho SO WATER RESOURCES RESEARCH LA English DT Article ID WALLED ROCK FRACTURES; THERMOHYDROLOGIC CONDITIONS; RELATIVE PERMEABILITY; CAPILLARY-PRESSURE; SOILS; TUFF AB A numerical model of a fractured basalt vadose zone has been developed on the basis of the conceptual model described by Faybishenko et al. [this issue]. The model has been used to simulate a ponded infiltration test in order to investigate infiltration through partially saturated fractured basalt. A key question addressed is how the fracture pattern geometry and fracture connectivity within a single basalt Row of the Snake River Plain basalt affect water infiltration. The two-dimensional numerical model extends from the ground surface to a perched water body 20 m below and uses an unconventional quasi-deterministic approach with explicit but highly simplified representation of major fractures and other important hydrogeologic features. The model adequately reproduces the majority of the field observation and provides insights into the infiltration process that cannot be obtained by data collection alone, demonstrating its value as a component of field studies. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Div Earth Sci, Berkeley, CA 94720 USA. RP Doughty, C (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Div Earth Sci, 1 Cyclotron Rd,MS 90-1116, Berkeley, CA 94720 USA. RI Doughty, Christine/G-2389-2015 NR 38 TC 7 Z9 7 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 DEC PY 2000 VL 36 IS 12 BP 3521 EP 3534 DI 10.1029/2000WR900146 PG 14 WC Environmental Sciences; Limnology; Water Resources SC Environmental Sciences & Ecology; Marine & Freshwater Biology; Water Resources GA 382BT UT WOS:000165799100009 ER PT J AU Callahan, TJ Reimus, PW Bowman, RS Haga, MJ AF Callahan, TJ Reimus, PW Bowman, RS Haga, MJ TI Using multiple experimental methods to determine fracture/matrix interactions and dispersion of nonreactive solutes in saturated volcanic tuff SO WATER RESOURCES RESEARCH LA English DT Article ID SINGLE FRACTURE; TRACER TESTS; SORBING SOLUTES; CONTAMINANT TRANSPORT; FLOW INTERRUPTION; MATRIX DIFFUSION; MASS-TRANSFER; FLUID-FLOW; MEDIA; ROCK AB The objective of this research was to investigate the effects of matrix diffusion on solute transport in fractured volcanic tuff. Two tuff cores were studied, one with a matrix porosity of 0.27 and the other with a porosity of 0.14. The matrix permeabilities of the cores were 4.7 x 10(-15) and 7.8 x 10(-19) m(2), 5 and 9 orders of magnitude less than the respective fracture permeabilities. This suggested that the cores could be modeled as dualporosity systems with no flow in the matrix but significant solute storage capacity. Two types of tracer tests were conducted in each fractured core: (1) iodide was injected in separate experiments at different flow rates and (2) two tracers of different matrix diffusion coefficients (bromide and pentafluorobenzoate (PFBA)) were injected in another test. A difference in the maximum concentrations of the solutes and the extended tailing of the breakthrough curves were assumed to be indicative of diffusive mass transfer between the fracture and the porous matrix of the cores. Interpreting the results from both methods allowed the identification of matrix diffusion and dispersion effects within the fracture by simultaneously fitting the data sets (with known constraints) using a relatively simple conceptual model. Estimates of mass transfer coefficients for the fractured cores were also obtained. C1 Univ Calif Los Alamos Natl Lab, Environm Sci & Waste Technol Grp, Los Alamos, NM 87545 USA. New Mexico Inst Min & Technol, Dept Earth & Environm Sci, Socorro, NM 87801 USA. RP Callahan, TJ (reprint author), Univ Calif Los Alamos Natl Lab, Environm Sci & Waste Technol Grp, Mail Stop J514, Los Alamos, NM 87545 USA. NR 38 TC 28 Z9 28 U1 2 U2 12 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 DEC PY 2000 VL 36 IS 12 BP 3547 EP 3558 DI 10.1029/2000WR900212 PG 12 WC Environmental Sciences; Limnology; Water Resources SC Environmental Sciences & Ecology; Marine & Freshwater Biology; Water Resources GA 382BT UT WOS:000165799100011 ER PT J AU Shvidler, M Karasaki, K AF Shvidler, M Karasaki, K TI Multicontinuum description of flow in composite heterogeneous media SO WATER RESOURCES RESEARCH LA English DT Article AB Adequacy of the description of flow and transport processes in subsurface depends on how well a model represents the heterogeneity. One of the simplest models to describe the heterogeneity structure is a so-called composite system. Flow and transport 'simulation in composite systems can be reduced to solving equations and averaging the solutions. A different approach related to averaging the equations leads to new equations. This description is designated as monocontinuum description. If the homogeneous components of a composite system, so-called phases, have different hydrodynamic and/or geometric parameters, it is natural to study averaging on the individual phases along with the global averaging. This approach takes into consideration the mean fields in the individual continuum phase as well as the cross flows and cross forces between continua. However, this description is nonclosed. To overcome this difficulty, the phenomenological theory usually postulates a special interaction mechanism for closing the equations. This paper presents the exact equations of mass balance and moment balance for each phase. The exact sense of exchange terms in the multicontinuum models is explained. We demonstrate that joint consideration of the monocontinual and multicontinual systems in the case of two-phase random composite leads to a closed description and that we can find the exchange terms. For a periodic composite system the same approach leads to a closed description for any number of phases. The terms describing the interactions between continua for systems with a random and periodical structure are calculated. We examine the hypothesis customarily made in the phenomenological models. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Div Earth Sci, Berkeley, CA 94720 USA. RP Shvidler, M (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Div Earth Sci, 1 Cyclotron Rd,MS 90-1116, Berkeley, CA 94720 USA. NR 15 TC 3 Z9 3 U1 1 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 DEC PY 2000 VL 36 IS 12 BP 3615 EP 3629 DI 10.1029/2000WR900221 PG 15 WC Environmental Sciences; Limnology; Water Resources SC Environmental Sciences & Ecology; Marine & Freshwater Biology; Water Resources GA 382BT UT WOS:000165799100017 ER PT J AU Hackett, RM Bennett, JG AF Hackett, RM Bennett, JG TI An implicit finite element material model for energetic particulate composite materials SO INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN ENGINEERING LA English DT Article DE high explosives; finite element constitutive model; mechanical behaviour; non-shock ignition ID HOT-SPOT IGNITION; CONSTITUTIVE MODEL; COHESIVE CRACK; EXPLOSIVES; MECHANISMS; VISCOELASTICITY AB The predisposition of energetic particulate composite materials, or high explosives (HE), to ignition by bulk heating (cookoff) poses serious safety problems. Because unexpected initiation of HE must be a major consideration in any activity involving employment of the material, its behaviour under a variety of conditions is of much interest. The formulation of a numerical constitutive model that can be employed in an implicit finite element code to predict the mechanical and ignition behaviour of HE is presented. The capability of the developed material model is then demonstrated through its implementation in the ABAQUS finite element code to simulate the response of HE test configurations. The simulated response is found to compare favourably with the physical test results, in the cases where test data exist. Copyright (C) 2000 John Wiley & Sons, Ltd. C1 Univ Calif Los Alamos Natl Lab, ESA EA, Los Alamos, NM 87544 USA. RP Bennett, JG (reprint author), Univ Calif Los Alamos Natl Lab, ESA EA, MS P946,Box 1663, Los Alamos, NM 87544 USA. NR 21 TC 17 Z9 24 U1 0 U2 7 PU JOHN WILEY & SONS LTD PI W SUSSEX PA BAFFINS LANE CHICHESTER, W SUSSEX PO19 1UD, ENGLAND SN 0029-5981 J9 INT J NUMER METH ENG JI Int. J. Numer. Methods Eng. PD NOV 30 PY 2000 VL 49 IS 9 BP 1191 EP 1209 DI 10.1002/1097-0207(20001130)49:9<1191::AID-NME997>3.0.CO;2-V PG 19 WC Engineering, Multidisciplinary; Mathematics, Interdisciplinary Applications SC Engineering; Mathematics GA 369KK UT WOS:000165064300005 ER PT J AU Lee, CT Psathas, PA Ziegler, KJ Johnston, KP Dai, HJ Cochran, HD Melnichenko, YB Wignall, GD AF Lee, CT Psathas, PA Ziegler, KJ Johnston, KP Dai, HJ Cochran, HD Melnichenko, YB Wignall, GD TI Formation of water-in-carbon dioxide microemulsions with a cationic surfactant: A small-angle neutron scattering study SO JOURNAL OF PHYSICAL CHEMISTRY B LA English DT Article ID WATER-IN-CO2 MICROEMULSIONS; INTERFACIAL-TENSION; BENDING ELASTICITY; OIL MICROEMULSIONS; CONTRAST VARIATION; PHASE-EQUILIBRIA; REVERSE MICELLES; METAL PARTICLES; MICRO-EMULSIONS; SYSTEM AB The formation of water-in-carbon dioxide microemulsions with a cationic perfluoropolyether trimethylammonium acetate surfactant, PFPE-C(O)-NH-CH2-N+(CH3)(3) CH3COO-, is reported over a range of temperatures (25-90 degreesC) and pressures (87.3-415 bar). Spherical droplets are observed by SANS with radii ranging from 16 to 36 Angstrom for water-to-surfactant molar ratios (W-o) from 9.5 to 28. Pored analysis of the SANS data indicates an area of approximately 60 Angstrom (2)/surfactant molecule at the water-CO2 interface, in reasonable agreement with the value of 72 Angstrom (2) determined from the change in the droplet radius with W-o. The CO2-phobic functionality between the surfactant headgroup and perfluoropolyether tail reduces CO2 penetration of the tails, resulting in a smaller area/surfactant than in the case of an anionic perfluoropolyether surfactant [Langmuir 1997, 13, 3934]. A relatively rigid film, with a mean film rigidity (2K + (K) over bar) of approximately 1 k(B)T, along with the strong partitioning of the surfactant toward CO2 versus water, lead to the small, rigid, spherical water droplets in CO2. C1 Univ Texas, Dept Chem Engn, Austin, TX 78712 USA. Univ Tennessee, Dept Chem Engn, Knoxville, TN 37996 USA. Oak Ridge Natl Lab, Div Chem Technol, Oak Ridge, TN 37831 USA. Oak Ridge Natl Lab, Div Solid State, Oak Ridge, TN 37831 USA. RP Johnston, KP (reprint author), Univ Texas, Dept Chem Engn, Austin, TX 78712 USA. RI Ziegler, Kirk/K-2658-2015 OI Ziegler, Kirk/0000-0001-6996-2791 NR 64 TC 65 Z9 66 U1 2 U2 9 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 NOV 30 PY 2000 VL 104 IS 47 BP 11094 EP 11102 PG 9 WC Chemistry, Physical SC Chemistry GA 378TP UT WOS:000165600700023 ER PT J AU Li, LS Wang, R Fitzsimmons, M Li, DQ AF Li, LS Wang, R Fitzsimmons, M Li, DQ TI Surface electronic properties of self-assembled, oppositely charged macrocycle and polymer multilayers on conductive oxides SO JOURNAL OF PHYSICAL CHEMISTRY B LA English DT Article ID BENZOIC-ACID DERIVATIVES; KELVIN PROBE TECHNIQUE; THIN-FILMS; WORK FUNCTION; ADSORPTION; PHTHALOCYANINE; CHEMISORPTION; GAAS; CDSE; CDTE AB Using the layer-by-layer self-assembly technique, we have deposited multilayer thin films on conductive indium tin oxide (ITO) surfaces by alternatively dipping ITO substrates in a polymer PDDA or poly(diallydimethylammonium) chloride solution and a macrocyle NiPc or nickel phthalocyanine solution. In addition to characterizing PDDA-NiPc systems with X-ray reflectometry and cyclic voltammetry, we monitored the growth of PDDA/NiPc multilayers on conductive oxides with Fourier transform infrared (IR) spectroscopy at an external grazing-angle reflection configuration. IR spectra with polarization perpendicular to the conductive ITO surfaces revealed vibration bands at 1227 and 1200 cm(-1) corresponding to salt bridges of -SO3-. . . Me2N+ = binding between PDDA and NiPc. An oscillation of the surface electronic potential was observed with a Kelvin Probe as the surface layer alternated between PDDA and NiPc. The average gap of the surface potential difference between NiPc and PDDA monolayers is about 400 mV. Oscillation of surface potential or work function is caused by the modulation in electron affinity of ITO due to the dipolar effect, generated by the highly charged layers of PDDA or NiPc. C1 Univ Calif Los Alamos Natl Lab, Div Mat Sci & Technol, MST, STC, Los Alamos, NM 87545 USA. Manuel Lujan Jr Neutron Scattering Ctr, Los Alamos, NM 87545 USA. RP Li, DQ (reprint author), Washington State Univ, Dept Chem, Pullman, WA 99164 USA. RI Lujan Center, LANL/G-4896-2012 NR 32 TC 22 Z9 22 U1 0 U2 5 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 1089-5647 J9 J PHYS CHEM B JI J. Phys. Chem. B PD NOV 30 PY 2000 VL 104 IS 47 BP 11195 EP 11201 DI 10.1021/jp001716j PG 7 WC Chemistry, Physical SC Chemistry GA 378TP UT WOS:000165600700035 ER PT J AU Stern, D Eisenhardt, P Spinrad, H Dawson, S van Breugel, W Dey, A de Vries, W Stanford, SA AF Stern, D Eisenhardt, P Spinrad, H Dawson, S van Breugel, W Dey, A de Vries, W Stanford, SA TI Evidence against a redshift z > 6 for the galaxy STIS123627+621755 SO NATURE LA English DT Article ID LUMINOSITY DENSITY; WHITE-DWARF; FIELD; UNIVERSE AB The identification of galaxies at extreme distances provides the most direct information about the earliest phases of galaxy formation. But at redshifts z>5 even the most luminous galaxies appear faint; the interpretation of low signal-to-noise ratio data is difficult and misidentifications do occur. Here we report optical and near-infrared observations of the source STIS123627+621755, which was previously suggested to be at a redshift of 6.68 (ref. 1). At that redshift, and with the reported 1 spectral energy distribution, the galaxy should be essentially invisible at wavelengths less than 9,300 Angstrom, because the intervening intergalactic medium absorbs almost all light energetic enough to ionize neutral hydrogen-that is, with wavelengths less than the redshifted Lyman limit of lambda = (1 + z) x 912 Angstrom. At near-infrared wavelengths, however, the galaxy should be relatively bright. Here we report a detection of the galaxy at 6,700 Angstrom and a non-detection at a wavelength of 1.2 mum, contrary to expectations for z approximate to 6.68. The data conservatively require that STIS123627+621755 has a redshift z< 6. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Univ Calif Berkeley, Dept Astron, Berkeley, CA 94720 USA. Lawrence Livermore Natl Lab, Inst Geophys & Planetary Phys, Livermore, CA 94550 USA. Kitt Peak Natl Observ, Natl Opt Astron Observ, Tucson, AZ 85726 USA. Univ Calif Davis, Dept Phys, Davis, CA 95616 USA. RP Dawson, S (reprint author), CALTECH, Jet Prop Lab, Mail Stop 169-327, Pasadena, CA 91109 USA. EM stern@zwolfkinder.jpl.nasa.gov OI Stern, David/0000-0002-1847-6483 NR 18 TC 13 Z9 13 U1 0 U2 3 PU NATURE PUBLISHING GROUP PI LONDON PA MACMILLAN BUILDING, 4 CRINAN ST, LONDON N1 9XW, ENGLAND SN 0028-0836 J9 NATURE JI Nature PD NOV 30 PY 2000 VL 408 IS 6812 BP 560 EP 562 DI 10.1038/35046027 PG 3 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 377WE UT WOS:000165548600110 PM 11117737 ER PT J AU Muscheler, R Beer, J Wagner, G Finkel, RC AF Muscheler, R Beer, J Wagner, G Finkel, RC TI Changes in deep-water formation during the Younger Dryas event inferred from Be-10 and C-14 records SO NATURE LA English DT Article ID GREENLAND ICE CORE; OCEAN CIRCULATION; ATMOSPHERIC C-14; RADIOCARBON; CLIMATE; DEGLACIATION; CALIBRATION; ATLANTIC; MODEL; CYCLE AB Variations in atmospheric radiocarbon (C-14) concentrations can be attributed either to changes in the carbon cycle(1)-through the rate of radiocarbon removal from the atmosphere-or to variations in the production rate of C-14 due to changes in solar activity or the Earth's magnetic field(2). The production rates of Be-10 and C-14 vary in the same way, but whereas atmospheric radiocarbon concentrations are additionally affected by the carbon cycle, Be-10 concentrations reflect production rates more directly. A record of the Be-10 production-rate variations can therefore be used to separate the two influences-production rates and the carbon cycle-on radiocarbon concentrations. Here we present such an analysis of the large fluctuations in atmospheric C-14 concentrations, of unclear origin(3), that occurred during the Younger Dryas cold period(6). We use the Be-10 record from the GISP2 ice core(5) to model past production rates of radionuclides, and rnd that the largest part of the fluctuations in atmospheric radiocarbon concentrations can be attributed to variations in production rate. The residual difference between measured C-14 concentrations and those modelled using the Be-10 record can be explained with an additional change in the carbon cycle, most probably in the amount of deep-water formation. C1 EAWAG, Dept Surface Waters, CH-8600 Dubendorf, Switzerland. Univ Calif Lawrence Livermore Natl Lab, Ctr Accelerator Mass Spectrometry, Livermore, CA 94550 USA. Univ Calif Lawrence Livermore Natl Lab, Geosci & Environm Technol Div, Livermore, CA 94550 USA. RP Muscheler, R (reprint author), EAWAG, Dept Surface Waters, CH-8600 Dubendorf, Switzerland. NR 30 TC 87 Z9 93 U1 2 U2 21 PU MACMILLAN PUBLISHERS LTD PI LONDON PA PORTERS SOUTH, 4 CRINAN ST, LONDON N1 9XW, ENGLAND SN 0028-0836 J9 NATURE JI Nature PD NOV 30 PY 2000 VL 408 IS 6812 BP 567 EP 570 DI 10.1038/35046041 PG 5 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 377WE UT WOS:000165548600113 PM 11117740 ER PT J AU Lipkin, HJ AF Lipkin, HJ TI Experimental puzzles in heavy flavor decays. Anomalously high eta ' appearance in charmless strange B decays - flavor SU(3) breaking in charm decays SO PHYSICS LETTERS B LA English DT Article ID CP VIOLATION; RESCATTERING; PHYSICS AB Simple experimental tests are proposed which can clarify the origin for the anomalously high eta' appearance in charmless strange final states in B decays and can investigate the the nature of SU(3) symmetry-breaking in weak heavy flavor decays. (C) 2000 Published by Elsevier Science B.V. C1 Weizmann Inst Sci, Dept Particle Phys, IL-76100 Rehovot, Israel. Tel Aviv Univ, Raymond & Beverly Sackler Fac Exact Sci, Sch Phys & Astron, IL-69978 Tel Aviv, Israel. Argonne Natl Lab, Div High Energy Phys, Argonne, IL 60439 USA. RP Lipkin, HJ (reprint author), Weizmann Inst Sci, Dept Particle Phys, IL-76100 Rehovot, Israel. NR 15 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 NOV 30 PY 2000 VL 494 IS 3-4 BP 248 EP 254 DI 10.1016/S0370-2693(00)01200-4 PG 7 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 380BX UT WOS:000165679400010 ER PT J AU Reilly, PTA Gieray, RA Whitten, WB Ramsey, JM AF Reilly, PTA Gieray, RA Whitten, WB Ramsey, JM TI Fullerene evolution in flame-generated soot SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Article ID TANDEM MASS-SPECTROMETRY; HYDROCARBON FLAMES; PREMIXED FLAMES; IONS; PARTICLES; PRESSURE; COMBUSTION; CHEMISTRY; C-60; PAH AB Direct observation of the chemical evolution of flame-generated soot was demonstrated for the first time using real-time aerosol mass spectrometry. The data presented unambiguously show the transformation of particle phase polycyclic aromatic hydrocarbons (PAHs) into carbonaceous soot containing fullerenes. The mechanism of fullerene formation in the particle phase that is revealed is not consistent with conventional gas-phase formation mechanisms. This mechanism suggests the possibility of a controlled condensed phase synthesis of fullerenes. C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Reilly, PTA (reprint author), Oak Ridge Natl Lab, POB 2008,4500S MS-6142, Oak Ridge, TN 37831 USA. NR 23 TC 23 Z9 23 U1 0 U2 15 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0002-7863 J9 J AM CHEM SOC JI J. Am. Chem. Soc. PD NOV 29 PY 2000 VL 122 IS 47 BP 11596 EP 11601 DI 10.1021/ja003521v PG 6 WC Chemistry, Multidisciplinary SC Chemistry GA 380HY UT WOS:000165696800004 ER PT J AU Randall, DW George, SD Hedman, B Hodgson, KO Fujisawa, K Solomon, EI AF Randall, DW George, SD Hedman, B Hodgson, KO Fujisawa, K Solomon, EI TI Spectroscopic and electronic structural studies of blue copper model complexes. 1. Perturbation of the thiolate-Cu bond SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Article ID X-RAY-ABSORPTION; RESONANCE RAMAN-SPECTRA; CRYSTAL-STRUCTURE ANALYSIS; CHARGE-TRANSFER DYNAMICS; LIGAND K-EDGE; ANGSTROM RESOLUTION; GROUND-STATE; PROTEINS; PLASTOCYANIN; SITE AB A tris(pyrazolyl)hydroborate triphenylmethylthiolate Cu(II) model complex (1) that reproduces structural and spectroscopic features of active sites of blue Cu proteins is characterized using low-temperature absorption, magnetic circular dichroism (MCD), X-ray absorption (XAS), and resonance Raman (rR) spectroscopies combined with DFT calculations to define its electronic structure. The electronic structure of 1 is further related to the oxidized Cu site in plastocyanin. The key spectral differences relative to plastocyanin include an increase in the intensity of the S p pi --> Cu CT band and a decrease in the absorption intensity at similar to 450 nm. The energies, of d --> d transitions in 1 decrease relative to plastocyanin, which reflects the more tetrahedral geometry of 1. S K-edge XAS measurements demonstrate a more covalent thiolate interaction in the HOMO of 1 (52% S p) than in plastocyanin (38% S p). The effects of the high thiolate;covalency drl:the absorption and Raman spectral features for I are evaluated. Additional changes in the absorption spectrum of 1 relative to plastocyanin in the similar to 450 nm and the near-infrared regions are due to differences in the electronic structure of the nitrogen ligands associated with the change from imidazole to pyrazole. Finally, XAS measurements at the Cu L- and K-edges indicate that the effective nuclear charge of Cu in I is higher than in plastocyanin, which likely results from misdirection of the ligating orbitals in the constrained tris(pyrazolyl)hydroborate Ligand system. This reduces the donor interaction of this ligand with the copper which increases I : the covalency of the thiolate-Cu bond and can contribute to the electron-transfer properties of the blue copper site. C1 Univ Tsukuba, Dept Chem, Tsukuba, Ibaraki 3058571, Japan. Stanford Univ, Dept Chem, Stanford, CA 94305 USA. Stanford Univ, Stanford Linear Accelerator Ctr, Stanford Synchrotron Radiat Lab, Stanford, CA 94309 USA. RP Fujisawa, K (reprint author), Univ Tsukuba, Dept Chem, Tsukuba, Ibaraki 3058571, Japan. RI DeBeer, Serena/G-6718-2012 NR 76 TC 79 Z9 80 U1 1 U2 16 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 NOV 29 PY 2000 VL 122 IS 47 BP 11620 EP 11631 DI 10.1021/ja001591w PG 12 WC Chemistry, Multidisciplinary SC Chemistry GA 380HY UT WOS:000165696800007 ER PT J AU Randall, DW George, SD Holland, PL Hedman, B Hodgson, KO Tolman, WB Solomon, EI AF Randall, DW George, SD Holland, PL Hedman, B Hodgson, KO Tolman, WB Solomon, EI TI Spectroscopic and electronic structural studies of blue copper model complexes. 2. Comparison of three- and four-coordinate Cu(II)-thiolate complexes and fungal laccase SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Article ID RAY ABSORPTION-EDGE; LIGAND K-EDGE; RESONANCE RAMAN; ANGSTROM RESOLUTION; CRYSTAL-STRUCTURE; ACTIVE-SITES; AXIAL LIGAND; PLASTOCYANIN; PROTEINS; STATE AB To evaluate the importance of the axial ligand in blue Cu centers, the electronic: structure of a three-coordinate model compound LCuSCPh3 (2, L, beta -diketiminate ligand) is defined using low-temperature absorption, magnetic circular dichroism (MCD), X-ray absorption spectroscopy (XAS), and resonance Raman (rR) profiles coupled with density functional calculations. Using these excited-state spectroscopic methods the electronic structure of 2 is compared to that of a four-coordinate blue Cu model compound LCuSCPh3 (1, L tris(pyrazolyl)hydroborate ligand) and the three-coordinate blue Cu center in fungal laccase. The spectral features of 2 are substantially altered from those of 1 and reflect a. trans influence of the beta -diketiminate ligand that involves a strong interaction with the Cu d(x2-y2) orbital, concomitant with a decreased S p pi interaction with the Cu d(x2-y2) orbital. The lack of an axial ligand coupled with the influence of this equatorial donor leads I to many of the perturbed spectral features of 2 relative to 1 including: the shift of the,S p pi --> Cu CT transition to lower energy and its reduced intensity, the stronger ligand field, the larger nitrogen covalency in the HOMO at the expense of thiolate covalency, and the decreased excited-state distortion. From XAS, it also is clear that loss of the axial pyrazole ligand in 2 relative to 1 leads to an increase in the effective nuclear charge of the three-coordinate Cu in 2, which demonstrates that the axial ligand modulates, the electronic structure. From a. comparison of 2 to fungal laccase it is evident that even in the absence of an axial ligand the electronic structure can be modulated by differential charge donation from the equatorial ligands. These studies show that elimination of the axial ligand of the blue copper site can affect the covalency of the thiolate-Cu bond and potentially modify the electron-transfer properties of the site. C1 Univ Minnesota, Dept Chem, Minneapolis, MN 55455 USA. Stanford Univ, Dept Chem, Stanford, CA 94305 USA. Stanford Univ, Stanford Linear Accelerator Ctr, Stanford Synchrotron Radiat Lab, Stanford, CA 94309 USA. RP Tolman, WB (reprint author), Univ Minnesota, Dept Chem, 207 Pleasant St SE, Minneapolis, MN 55455 USA. RI DeBeer, Serena/G-6718-2012 NR 73 TC 119 Z9 119 U1 2 U2 27 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 NOV 29 PY 2000 VL 122 IS 47 BP 11632 EP 11648 DI 10.1021/ja001592o PG 17 WC Chemistry, Multidisciplinary SC Chemistry GA 380HY UT WOS:000165696800008 ER PT J AU MacDonald, JC Dorrestein, PC Pilley, MM Foote, MM Lundburg, JL Henning, RW Schultz, AJ Manson, JL AF MacDonald, JC Dorrestein, PC Pilley, MM Foote, MM Lundburg, JL Henning, RW Schultz, AJ Manson, JL TI Design of layered crystalline materials using coordination chemistry and hydrogen bonds SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Article ID MOLECULAR-SOLIDS; ORGANIC-CRYSTALS; PACKING ARRANGEMENTS; TAPES; STATE; ACID; COMPLEXES; NETWORKS; STRATEGIES; FRAMEWORK AB The supramolecular chemistry and crystal structures of five bis(imidazolium 2,6-pyridinedicarboxylate)M(II) trihydrate complexes, where M = Mn2+, Co2+, Ni2+ Cu2+, Or Zn2+ (1-5, respectively), are reported. These complexes serve as supramolecular building blocks that self-assemble when crystallized to generate a single, well-defined, predictable structure in the solid state. 2,6-Pyridinedicarboxylate anions and imidazolium cations form strong ionic hydrogen bonds that dominate crystal packing in compounds 1-5 by forming two-dimensional networks. or layers of molecules. This layer motif serves as a platform with which to control and predict molecular packing by design for engineering the structures of crystals. Moreover, compounds 1-5 create a robust organic host lattice that accommodates five different transition metals without significantly altering molecular packing. Growth of crystals from solutions that contain two or more different metal complexes produces mixed crystals in which mixtures of the different metal complexes are incorporated in the same relative molar ratio present in solution. Epitaxial growth of crystals from one metal complex on the surface of a seed crystal that contains a second metal complex generates composite crystals in which the different metal complexes are segregated into different regions of the crystals. Compounds 1-5 form crystalline solids that represent. a new class of modular materials in which the organic ligands serve as a structural component that defines a single packing arrangement that persists over a range of structures, and in which the metal serves as an interchangeable component with which to vary the physical properties of the material. C1 No Arizona Univ, Dept Chem, Flagstaff, AZ 86011 USA. Argonne Natl Lab, Div Intense Pulsed Neutron Source, Argonne, IL 60439 USA. Argonne Natl Lab, Div Chem, Argonne, IL 60439 USA. Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. RP No Arizona Univ, Dept Chem, Flagstaff, AZ 86011 USA. RI Dorrestein, Pieter/D-5012-2012 NR 67 TC 220 Z9 222 U1 5 U2 35 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 NOV 29 PY 2000 VL 122 IS 47 BP 11692 EP 11702 DI 10.1021/ja002102v PG 11 WC Chemistry, Multidisciplinary SC Chemistry GA 380HY UT WOS:000165696800013 ER PT J AU Nabedryk, E Breton, J Joshi, HM Hanson, DK AF Nabedryk, E Breton, J Joshi, HM Hanson, DK TI Fourier transform infrared evidence of proton uptake by glutamate L212 upon reduction of the secondary quinone Q(B) in the photosynthetic reaction center from Rhodobacter capsulatus SO BIOCHEMISTRY LA English DT Article ID BACTERIAL REACTION CENTERS; FTIR DIFFERENCE SPECTROSCOPY; BACTERIOPHEOPHYTIN ELECTRON-ACCEPTOR; SITE-DIRECTED MUTAGENESIS; MUTANT REACTION CENTERS; RHODOPSEUDOMONAS-VIRIDIS; BINDING-SITES; SPHAEROIDES R-26; C-13-LABELED UBIQUINONE; 2ND-SITE MUTATION AB The photoreduction of the secondary quinone Q(B) in native reaction centers (RCs) of Rhodobacter capsulatus and in RCs from the GluL212 --> Gln and GluL212 --> Ala mutants has been investigated at pH 7 in (H2O)-H-1 and (H2O)-H-2 by light-induced Fourier transform infrared (FTIR) difference spectroscopy. The Q(B)(-)/Q(B) FTIR difference spectra reflect changes of quinone-protein interactions and of protonation state of carboxylic acid groups as well as reorganization of the protein upon electron transfer. Comparison of Q(B)(-)/Q(B) spectra of native and mutant RCs indicates that the interactions between Q(B) or Q(B)(-) and the protein are similar in all RCs. A differential signal at similar to 1650/1640 cm(-1), which is common to all the spectra, is associated with a movement of a peptide carbonyl or a side chain following Q(B) reduction. On the other hand, Q(B)(-)/Q(B) spectra of native and mutant RCs display several differences, notably between 1700 and 1650 cm(-1) (amide I and side chains), between 1570 and 1530 cm(-1) (amide II), and at 1728-1730 cm(-1) (protonated carboxylic acid groups). In particular, the latter region in native RCs is characterized by a main positive band at 1728 cm(-1) and a negative signal at 1739 cm(-1). In the L212 mutants, the amplitude of the positive band is strongly decreased leading to a differential signal at 1739/1730 cm(-1) that is insensitive to H-1/H-2 isotopic exchange. In native RCs, only the 1728 cm(-1) band is affected in (H2O)-H-2 while the 1739 cm(-1) signal is not. The effects of the mutations and of H-1/H-2 exchange on the Q(B)(-)/Q(B) spectra concur in the attribution of the 1728 cm(-1) band in native RCs to (partial) proton uptake by GluL212 upon the first electron transfer to Q(B), as previously observed in Rhodobacter sphaeroides RCs [Nabedryk, E., Breton, J., Hienerwadel, R., Fogel, C., Mantele, W., Paddock, M. L., and Okamura, M. Y. (1995) Biochemistry 34, 14722-14732]. More generally, strong homologies of the Q(B) to Q(B) transition in the RCs from Rb. sphaeroides and Rb. capsulatus are detected by differential FTIR spectroscopy. The FTIR data are discussed in relation with the results from global proton uptake measurements and electrogenic events concomitant with the reduction of Q(B) and with a model of the Q(B) turnover in Rb. sphaeroides RC[Mulkidjanian, A. Y. (1999) FEES Lett. 463, 199-204]. C1 CEA Saclay, DBCM, SBE, F-91191 Gif Sur Yvette, France. Argonne Natl Lab, Biosci Div, Argonne, IL 60439 USA. RP Nabedryk, E (reprint author), CEA Saclay, DBCM, SBE, Bat 532, F-91191 Gif Sur Yvette, France. NR 81 TC 17 Z9 17 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0006-2960 J9 BIOCHEMISTRY-US JI Biochemistry PD NOV 28 PY 2000 VL 39 IS 47 BP 14654 EP 14663 DI 10.1021/bi0013795 PG 10 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA 378UE UT WOS:000165602400035 PM 11087422 ER PT J AU Riley, ME Ritchie, AB AF Riley, ME Ritchie, AB TI Excitation and ionization in H(1s)-H(1s) collisions: II. Inclusion of electron exchange SO JOURNAL OF PHYSICS B-ATOMIC MOLECULAR AND OPTICAL PHYSICS LA English DT Article ID HYDROGEN; IMPACT AB Hydrogen atom-hydrogen atom scattering is a prototype for many of the fundamental principles of atomic collisions. In this work we present the formalism and the predictions of a time-dependent self-consistent-field description of the H + H system for scattering in the intermediate energy regime of 1-100 keV. Because of the unrestricted nature of the numerical orbital description, this method includes the effects of an unlimited basis set within each orbital. Electron exchange and a limited amount of electron correlation are included as well. We solve numerically coupled three-dimensional Schrodinger equations for the two-electron orbitals in singlet and triplet symmetries. Excitation and ionization cross sections are computed and compared with other theory and experiment. The results capture many features of the problem but illustrate a need for more quantitative experimental information concerning the H + H system in this energy range. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Riley, ME (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. NR 17 TC 2 Z9 3 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 NOV 28 PY 2000 VL 33 IS 22 BP 5177 EP 5190 DI 10.1088/0953-4075/33/22/318 PG 14 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA 387CE UT WOS:000166101900021 ER PT J AU Maya, L Muralidharan, G Thundat, TG Kenik, EA AF Maya, L Muralidharan, G Thundat, TG Kenik, EA TI Polymer-mediated assembly of gold nanoclusters SO LANGMUIR LA English DT Article ID TRANSISTOR; NANOPARTICLES; SUPERLATTICES; TEMPERATURE; FABRICATION; MONOLAYERS; CLUSTERS; ARRAYS; FILMS AB Low molecular weight, less than or equal to 4000, polymers containing amine functionalities such as polyethyleneimine or poly-L-lysine serve as a scaffold for assembly of carboxylic acid functionalized gold clusters. The assembly produces at the liquid-air interface of the reaction medium, free-standing, space-filling films that are one monolayer thick. Assembly was promoted through the formation of peptide bonds by the addition of a carbodiimide but also proceeds in the absence of the carbodiimide by ion palling. The morphology of the films is sensitive to the nature of the acid coating on the gold clusters with mercaptododecanoic acid and mercaptosuccinic acid forming more regular films than those coated with thioctic acid. C1 Oak Ridge Natl Lab, Div Chem & Analyt Sci, Oak Ridge, TN 37831 USA. Oak Ridge Natl Lab, Div Life Sci, Oak Ridge, TN 37831 USA. Oak Ridge Natl Lab, Div Met & Ceram, Oak Ridge, TN 37831 USA. RP Maya, L (reprint author), Oak Ridge Natl Lab, Div Chem & Analyt Sci, Oak Ridge, TN 37831 USA. RI Muralidharan, Govindarajan/J-6155-2015 NR 26 TC 24 Z9 24 U1 4 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 NOV 28 PY 2000 VL 16 IS 24 BP 9151 EP 9154 DI 10.1021/la0008737 PG 4 WC Chemistry, Multidisciplinary; Chemistry, Physical; Materials Science, Multidisciplinary SC Chemistry; Materials Science GA 376VR UT WOS:000165477900012 ER PT J AU Kim, SH Tewell, CR Somorjai, GA AF Kim, SH Tewell, CR Somorjai, GA TI Surface characterization of the TiClx/MgCl2 model Ziegler-Natta polymerization catalysts: Adsorption site studies using mesitylene thermal desorption SO LANGMUIR LA English DT Article ID MOLECULAR-WEIGHT DISTRIBUTION; OLEFIN POLYMERIZATION; POLYPROPYLENE; SPECTROSCOPY; MONOLAYER; HALIDES; MGCL2 AB Temperature-programmed desorption (TPD) of physisorbed mesitylene molecules has been used as a nondestructive surface probe to distinguish the surface adsorption sites of model Ziegler-Natta polymerization catalysts. A MgCl2-supported titanium chloride film (TiClx/MgCl2) was fabricated on an inert gold substrate by codeposition of Mg metal and TiCl4 from the gas phase. The mesitylene TPD probe revealed two types of surface adsorption sites. The dominant site was attributed to the basal plane of these halide crystallites. The minor site could be tentatively attributed to a defective structure at the basal plant boundaries or other crystal planes. Due to the chlorine termination nature of the catalyst surface, the metal ions under the chlorine layer could not be differentiated directly with the physisorbed mesitylene molecules. However, the mesitylene TPD profile was able to monitor compositional changes in the outermost chlorine layer accompanying the reaction of the catalyst film with the triethylaluminum cocatalyst, electron beam irradiation of the film surface, and diffusion of bulk chlorine to minimize the number of defect sites. C1 Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. Lawrence Berkeley Natl Lab, Div Mat Sci, Berkeley, CA 94720 USA. RP Somorjai, GA (reprint author), Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. NR 39 TC 20 Z9 20 U1 0 U2 3 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0743-7463 J9 LANGMUIR JI Langmuir PD NOV 28 PY 2000 VL 16 IS 24 BP 9414 EP 9420 DI 10.1021/la000194w PG 7 WC Chemistry, Multidisciplinary; Chemistry, Physical; Materials Science, Multidisciplinary SC Chemistry; Materials Science GA 376VR UT WOS:000165477900052 ER PT J AU O'Brien, JC Stickney, JT Porter, MD AF O'Brien, JC Stickney, JT Porter, MD TI Preparation and characterization of self-assembled double-stranded DNA (dsDNA) microarrays for protein : dsDNA screening using atomic force microscopy SO LANGMUIR LA English DT Article ID GOLD SURFACES; ALKANETHIOL MONOLAYERS; ARRAYS; DISULFIDES; SPECTROSCOPY; CLEAVAGE; AU(111); THIOL AB We report details on the development of a self-assembled, double-stranded DNA (dsDNA) microarray fabrication strategy suitable for protein:dsDNA screening using the atomic force microscope (AFM). Using disulfide-modified dsDNA (26-mer) synthesized to contain the recognition sequence for ECoR1, we have created micron-sized mixed monolayer surfaces where both the spatial orientation and packing density of the immobilized oligonucleotides, two critical parameters for screening protein:dsDNA interactions, are controlled. Before exposure to ECoR1, the topography of microarrays that were composed of 26-mers containing the recognition sequence for EcoR1 was 8.8 nm +/- 1.5 nm (n = 5), a value consistent with that predicted by X-ray diffraction studies. After enzyme digestion, the topography of the microarray decreased to 4.3 nm +/- 0.8 nm (n = 14), a value consistent with predictions based on the position of the recognition sequence within the oligonucleotides. In contrast, the topography of microarrays that were composed of 26-mers that did not contain the recognition sequence for ECoR1 remained essentially the same before (8.9 nm +/- 1.5 nm (n = 5)) and after (8.3 nm +/- 1.4 nm (n = 5)) exposure to ECoR1. Furthermore, because the dsDNA were synthesized to include a fluorescein moiety above the recognition sequence, the loss of fluorescence after exposure to ECoR1 was also used to detect enzymatic cleavage. We believe that this technology holds promise as a tool for the rapid and facile screening of multiple protein interactions using massively parallel dsDNA microarrays. C1 US DOE, Ames Lab, Microanalyt Instrumentat Ctr, Ames, IA 50011 USA. Iowa State Univ, Dept Chem, Ames, IA 50011 USA. RP Porter, MD (reprint author), US DOE, Ames Lab, Microanalyt Instrumentat Ctr, Ames, IA 50011 USA. NR 30 TC 35 Z9 38 U1 3 U2 8 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0743-7463 J9 LANGMUIR JI Langmuir PD NOV 28 PY 2000 VL 16 IS 24 BP 9559 EP 9567 DI 10.1021/la000570c PG 9 WC Chemistry, Multidisciplinary; Chemistry, Physical; Materials Science, Multidisciplinary SC Chemistry; Materials Science GA 376VR UT WOS:000165477900071 ER PT J AU Androsch, R Wunderlich, B AF Androsch, R Wunderlich, B TI Analysis of the degree of reversibility of crystallization and melting in poly(ethylene-co-1-octene) SO MACROMOLECULES LA English DT Article ID DIFFERENTIAL SCANNING CALORIMETRY; X-RAY-SCATTERING; TEMPERATURE-MODULATED CALORIMETRY; ETHYLENE-OCTENE COPOLYMERS; HEAT-CAPACITY; HOMOGENEOUS COPOLYMERS; LINEAR POLYETHYLENE; GLASS-TRANSITION; POLYMER CRYSTALS; ANGLE AB The degree of reversibility of crystallization and melting of poly(ethylene-co-1-octene) containing 7.3 mol % (24 mass %) of 1-octene was measured with temperature-modulated differential scanning calorimetry. The sample was crystallized at different cooling rates after excluding self-nuclei of the crystals. The sample was also examined by X-ray scattering techniques, infrared spectroscopy, and standard differential scanning calorimetry. The cooling rates ranged from 0.1 K min(-1) to quick quenching. The low-temperature enthalpy remained constant in all cases, by increasingly creating a pseudohexagonal crystallinity of lower heat of fusion instead of a smaller amount of orthorhombic crystals. The crystallization during cooling from the nonseeded melt is characterized by a steplike crystal growth, a characteristic not seen on slow, seeded, crystallization. The initial growth is followed by a continuous increase of the crystallinity down to the glass transition. The onset of crystallization shifts to lower temperatures with increasing cooling rates. With increasing cooling rate, the perfection and the size of the initially formed crystals decrease. On slow crystallization orthorhombic crystals grow; on fast crystallization, these are increasingly replaced by the less-ordered, pseudohexagonal crystals. These changes are paralleled by a systematic increase of the reversible crystallization and melting by about 10% when increasing the cooling rate from 1 to 10 K min(-1). For the first time these surprising observations have been dic;cussed on the basis of structural information. C1 Univ Tennessee, Dept Chem, Knoxville, TN 37996 USA. Univ Halle Wittenberg, Inst Mat Sci, D-06217 Merseburg, Germany. Oak Ridge Natl Lab, Div Chem & Analyt Sci, Oak Ridge, TN 37831 USA. RP Wunderlich, B (reprint author), Univ Tennessee, Dept Chem, Knoxville, TN 37996 USA. NR 83 TC 75 Z9 75 U1 3 U2 9 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0024-9297 J9 MACROMOLECULES JI Macromolecules PD NOV 28 PY 2000 VL 33 IS 24 BP 9076 EP 9089 DI 10.1021/ma000504h PG 14 WC Polymer Science SC Polymer Science GA 379CW UT WOS:000165624200024 ER PT J AU Bourret-Courchesne, ED Kellermann, S Yu, KM Benamara, M Liliental-Weber, Z Washburn, J Irvine, SJC Stafford, A AF Bourret-Courchesne, ED Kellermann, S Yu, KM Benamara, M Liliental-Weber, Z Washburn, J Irvine, SJC Stafford, A TI Reduction of threading dislocation density in GaN using an intermediate temperature interlayer SO APPLIED PHYSICS LETTERS LA English DT Article ID MOCVD AB GaN thin films with a reduced threading dislocation density have been produced by organometallic vapor phase epitaxy using an intermediate temperature interlayer. A description of the growth process is presented with characterization results. Reduction of the dislocation density was obtained by insertion of a single thin interlayer grown at an intermediate temperature after the initial growth at high temperature. A large percentage of the threading dislocations present in the first GaN epilayer are found to bend in the interlayer and do not propagate in the top layer grown at higher temperature in a lateral growth mode. (C) 2000 American Institute of Physics. [S0003-6951(00)00849-4]. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. NEWI, Optoelect Mat Res Lab, Wrexham L111 2AW, Wales. RP Bourret-Courchesne, ED (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, 1 Cyclotron Rd MS 2-200, Berkeley, CA 94720 USA. RI Liliental-Weber, Zuzanna/H-8006-2012; Yu, Kin Man/J-1399-2012 OI Yu, Kin Man/0000-0003-1350-9642 NR 15 TC 24 Z9 29 U1 2 U2 8 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD NOV 27 PY 2000 VL 77 IS 22 BP 3562 EP 3564 AR PII [S0003-6951(00)00849-4] DI 10.1063/1.1329635 PG 3 WC Physics, Applied SC Physics GA 375JU UT WOS:000165396400026 ER PT J AU Thiesen, J Branz, HM Crandall, RS AF Thiesen, J Branz, HM Crandall, RS TI Explanation of the limiting thickness observed in low-temperature silicon epitaxy SO APPLIED PHYSICS LETTERS LA English DT Article ID CHEMICAL-VAPOR-DEPOSITION; SI(100); GROWTH AB Solution of the partial differential equation for diffusion of mobile atoms during solid film growth demonstrates that the observed phase transition in low-temperature silicon epitaxy is triggered by supersaturation of the growing layer with hydrogen. The limiting thickness of the epitaxial layer, h(epi), is completely determined by measurable quantities: the flux of hydrogen, the hydrogen diffusion coefficient, and the layer growth rate. Our model accounts for the observed Arrhenius and growth rate dependence of h(epi). (C) 2000 American Institute of Physics. [S0003-6951(00)02348-2]. C1 Natl Renewable Energy Lab, Golden, CO 80401 USA. RP Thiesen, J (reprint author), Technol Applicat Inc, 5455 Conestoga Court, Boulder, CO 80301 USA. NR 19 TC 32 Z9 32 U1 1 U2 2 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD NOV 27 PY 2000 VL 77 IS 22 BP 3589 EP 3591 AR PII [S0003-6951(00)02348-2] DI 10.1063/1.1328767 PG 3 WC Physics, Applied SC Physics GA 375JU UT WOS:000165396400035 ER PT J AU McHugo, SA Flink, C AF McHugo, SA Flink, C TI Thermal stability of copper precipitates in silicon SO APPLIED PHYSICS LETTERS LA English DT Article ID CZOCHRALSKI-GROWN SILICON; STACKING-FAULTS; DISLOCATIONS; IMPURITIES; SURFACE; DEFECTS; IRON; SI; FE AB The dissolution of copper precipitates in Czochralski silicon has been studied with synchrotron-based x-ray fluorescence. Copper has been introduced and allowed to precipitate at oxygen precipitates and growth-related stacking faults. The dissolution of copper precipitates is monitored after low-temperature anneals. This study is designed to determine whether copper can be released from these precipitation sites at low temperatures such that contamination and subsequent device degradation of an integrated circuit device could occur. Our results demonstrate copper dissolution back into the silicon matrix at temperatures as low as 360 degreesC. (C) 2000 American Institute of Physics. [S0003-6951(00)02548-1]. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP McHugo, SA (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, 1 Cyclotron Rd,Mail Stop 2-400, Berkeley, CA 94720 USA. NR 24 TC 13 Z9 14 U1 0 U2 2 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD NOV 27 PY 2000 VL 77 IS 22 BP 3598 EP 3600 AR PII [S0003-6951(00)02548-1] DI 10.1063/1.1328769 PG 3 WC Physics, Applied SC Physics GA 375JU UT WOS:000165396400038 ER PT J AU Chung, G Tin, CC Williams, JR McDonald, K Di Ventra, M Chanana, RK Pantelides, ST Feldman, LC Weller, RA AF Chung, G Tin, CC Williams, JR McDonald, K Di Ventra, M Chanana, RK Pantelides, ST Feldman, LC Weller, RA TI Effects of anneals in ammonia on the interface trap density near the band edges in 4H-silicon carbide metal-oxide-semiconductor capacitors SO APPLIED PHYSICS LETTERS LA English DT Article AB Results of room temperature capacitance-voltage measurements are reported for SiO2/4H-SiC (n and p type) metal-oxide-semiconductor capacitors annealed in ammonia following oxide layer growth using standard wet oxidation techniques. For n-SiC capacitors, both the interface state density near the conduction band edge and the effective oxide charge are substantially reduced by the ammonia anneals. For 2 h anneals, the oxide charge appears to have a minimum value for an anneal temperature of approximately 1100 degreesC. However, for p-SiC, anneals in ammonia produce no improvement in the interface state density near the valence band edge, and the effective oxide charge is not reduced compared to samples that were not annealed. Results are compared to those reported previously for anneals in nitric oxide. Ion beam analyses of the oxide layers show substantially more nitrogen incorporation with the ammonia anneals, although for n-SiC, the decrease in D-it is comparable for both nitric oxide and ammonia anneals. Results reported here for ammonia and those reported previously for nitric oxide are the first to demonstrate that significant passivation of the interface state density near the conduction band edge in SiC can be achieved with high temperature anneals using either gas. This demonstration has important implications for SiC metal-oxide-semiconductor field effect transistor technology development. (C) 2000 American Institute of Physics. [S0003-6951(00)00948-7]. C1 Auburn Univ, Dept Phys, Auburn, AL 36849 USA. Vanderbilt Univ, Dept Phys & Astron, Nashville, TN 37235 USA. Vanderbilt Univ, Dept Elect Engn & Comp Sci, Nashville, TN 37235 USA. Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Chung, G (reprint author), Auburn Univ, Dept Phys, Auburn, AL 36849 USA. RI Di Ventra, Massimiliano/E-1667-2011; Tin, Chin-Che/A-9122-2012 OI Di Ventra, Massimiliano/0000-0001-9416-189X; NR 15 TC 38 Z9 38 U1 0 U2 9 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD NOV 27 PY 2000 VL 77 IS 22 BP 3601 EP 3603 DI 10.1063/1.1328370 PG 3 WC Physics, Applied SC Physics GA 375JU UT WOS:000165396400039 ER PT J AU Yu, KM Walukiewicz, W Shan, W Wu, J Beeman, JW Ager, JW Haller, EE AF Yu, KM Walukiewicz, W Shan, W Wu, J Beeman, JW Ager, JW Haller, EE TI Increased electrical activation in the near-surface region of sulfur and nitrogen coimplanted GaAs SO APPLIED PHYSICS LETTERS LA English DT Article ID N-TYPE GAAS; INDIUM-PHOSPHIDE; OHMIC CONTACTS; INP; SEMICONDUCTORS; RESISTANCE; REDUCTION; EMISSION; BARRIERS; FIELD AB A large increase in the electrical activation of sulfur coimplanted with nitrogen in GaAs is observed within a thin (< 500 Angstrom) near-surface region. A free electron concentration as high as 1.5x10(19) cm(-3) is observed in this layer, which is a factor of 5 higher than in a GaAs sample implanted with S only. The high free electron concentration in this thin layer is the result of the incorporation of N on the As site which forms a thin dilute GaN(x)As(1-x) alloy layer. The increased electrical activity of S in this layer is explained by the N-induced modifications of the conduction band as predicted by the band anticrossing model. The measured free electron concentration is consistent with a GaN(x)As(1-x) alloy layer with x similar to0.3%. The results have important practical implications on the fabrication of low-resistance, nonalloyed ohmic contacts to n-type GaAs. (C) 2000 American Institute of Physics. [S0003-6951(00)02248-8]. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Ctr Adv Mat, Berkeley, CA 94720 USA. RP Yu, KM (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Ctr Adv Mat, Berkeley, CA 94720 USA. EM kmyu@lbl.gov RI Yu, Kin Man/J-1399-2012; Wu, Junqiao/G-7840-2011; OI Yu, Kin Man/0000-0003-1350-9642; Wu, Junqiao/0000-0002-1498-0148; Ager, Joel/0000-0001-9334-9751 NR 26 TC 13 Z9 13 U1 0 U2 1 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD NOV 27 PY 2000 VL 77 IS 22 BP 3607 EP 3609 AR PII [S0003-6951(00)02248-8] DI 10.1063/1.1328766 PG 3 WC Physics, Applied SC Physics GA 375JU UT WOS:000165396400041 ER PT J AU Findikoglu, AT Jia, QX Hahn, SF AF Findikoglu, AT Jia, QX Hahn, SF TI Dynamic time expansion and compression using nonlinear waveguides SO APPLIED PHYSICS LETTERS LA English DT Article ID DIELECTRIC SRTIO3; TEMPERATURE AB We have used coplanar waveguides made from nonlinear dielectric strontium titanate and superconducting YBa2Cu3O7 electrodes to perform dynamic time expansion (DTE) and dynamic time compression (DTC) on fast signals with nanosecond duration. Experiments on 7.8-cm-long waveguides using bipulses with peak-to-peak amplitude on the order of 10 V and peak-to-peak separation of about 1 ns yielded DTC of about -50%, and DTE of about +50%. The implementation of DTE in fast detectors and data acquisition systems at the analog-to-digital conversion stage could enable these systems to operate with improved time resolution. The DTC could be used at the output of high-speed analog-to-digital converters or in radar applications. (C) 2000 American Institute of Physics. [S0003-6951(00)02849-7]. C1 Univ Calif Los Alamos Natl Lab, Div Mat Sci & Technol, Superconduct Technol Ctr, Los Alamos, NM 87545 USA. Univ Calif Los Alamos Natl Lab, Nonproliferat & Int Secur Div, Space Instrumentat & Syst Engn, Los Alamos, NM 87545 USA. RP Findikoglu, AT (reprint author), Univ Calif Los Alamos Natl Lab, Div Mat Sci & Technol, Superconduct Technol Ctr, Los Alamos, NM 87545 USA. RI Jia, Q. X./C-5194-2008 NR 8 TC 4 Z9 4 U1 0 U2 1 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD NOV 27 PY 2000 VL 77 IS 22 BP 3645 EP 3647 DI 10.1063/1.1329872 PG 3 WC Physics, Applied SC Physics GA 375JU UT WOS:000165396400054 ER PT J AU Burns, CJ Clark, DL Donohoe, RJ Duval, PB Scott, BL Tait, CD AF Burns, CJ Clark, DL Donohoe, RJ Duval, PB Scott, BL Tait, CD TI A trigonal bipyramidal uranyl amido complex: Synthesis and structural characterization of [Na(THF)(2)] [UO2(N(SiMe3)(2))(3)] SO INORGANIC CHEMISTRY LA English DT Article ID CRYSTAL-STRUCTURES; ION; PRECURSORS AB The synthesis and structural characterization of a rare example of a uranyl complex possessing three equatorial ligands, [M(THF)(2)][UO2(N(SiMe3)(2))(3)] (3a, M = Na; 3b, M = K), are described. The sodium salt 3a is prepared by protonolysis of [Na(THF)(2)](2)[UO2(N(SiMe3)(2))(4)], wherea's the potassium salt 3b is obtained via a metathesis reaction of uranyl chloride UO2Cl2(THF)(2) (4) with 3 equiv of K[N(SiMe3)(2)]. A single-crystal X-ray diffraction study of 3a revealed a trigonal-bipyramidal geometry about uranium, formed by two axial oxo and three equatorial amido ligands, with average U=O and U-N bond distances of 1.79675) and 2.310(4) Angstrom, respectively. One of the oxo ligands is also coordinated to the sodium counterion. H-1 NMR spectroscopic studies indicate that THF adds reversibly as a ligand to 3 to expand the trigonal bipyramidal geometry. The degree to which the coordination sphere in,3 is electronically satisfied;with only three amido donors:is suggested by (1) the reversible THF coordination, (2) a modest elongation in the bond distances for a five-coordinate U(VI) complex, and (3) the basicity of the oxo ligands as evidenced ih the contact to Na. The vibrational spectra of the series of uranyl amido complexes [UO2(N(SiMe3)(2))(n)](2-n) (n = 2-4) are compared, to evaluate the effects on the axial U=O bonding as a function of increased electron density donated from the equatorial region. Raman spectroscopic measurements of the nu (1) symmetric O=U=O stretch show progressive axial bond weakening as the number of amido donors is increased. Crystal data for [Na(THF)(2)][UO2(N(SiMe3)(2))(3)]: orthorhombic space group Pna2(1), a = 22.945(1) Angstrom, b = 15.2830(7) Angstrom, c = 12.6787(6) Angstrom, z = 4, R1 = 0.0309, wR2 = 0.0524. C1 Univ Calif Los Alamos Natl Lab, Chem Sci & Technol Div, Los Alamos, NM 87545 USA. Univ Calif Los Alamos Natl Lab, Div Nucl Mat Technol, Los Alamos, NM 87545 USA. Univ Calif Los Alamos Natl Lab, GT Seaborg Inst Transactinium Sci, Los Alamos, NM 87545 USA. RP Burns, CJ (reprint author), Univ Calif Los Alamos Natl Lab, Chem Sci & Technol Div, POB 1663, Los Alamos, NM 87545 USA. RI Clark, David/A-9729-2011; Scott, Brian/D-8995-2017 OI Scott, Brian/0000-0003-0468-5396 NR 34 TC 74 Z9 74 U1 0 U2 33 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 NOV 27 PY 2000 VL 39 IS 24 BP 5464 EP 5468 DI 10.1021/ic0003168 PG 5 WC Chemistry, Inorganic & Nuclear SC Chemistry GA 378AX UT WOS:000165560000013 PM 11154561 ER PT J AU Abrams, MB Scott, BL Baker, RT AF Abrams, MB Scott, BL Baker, RT TI Sterically tunable phosphenium cations: Synthesis and characterization of bis(arylamino)phosphenium ions, phosphinophosphenium adducts, and the first well-defined rhodium phosphenium complexes SO ORGANOMETALLICS LA English DT Article ID TRANSITION-METAL-COMPLEXES; RAY CRYSTAL-STRUCTURES; 14 ELEMENT LIGAND; DIPHOSPHORUS COMPOUNDS; MIGRATORY INSERTION; STEPWISE SYNTHESIS; PHOSPHORUS-COBALT; MULTIPLE BONDS; LEWIS-ACID; REACTIVITY AB A family of bis(arylamino)chlorophosphines of the general formula CIPN(Ar)CH(2)CH(2)N(Ar) (Ar = 4-MeO-C(6)H(4), 3a; Ar = 2,4,6-Me(3)-C(6)H(2), 3b; Ar = 2,6-(CHMe(2))(2)-C(6)H(3), 3c) has been prepared from PCl(3) and the appropriate diamine. Steric interactions involving the 2,6-aryl substituents in 3b,c result in hindered rotation about the N-C(Ar) bond, as evidenced by (1)H NMR spectroscopy. Treatment of halophosphines 3a-c with AgOSO(2)CF(3) (AgOTf) or Tl{B[3,5-(CF(3))(2)-C(6)H(3)](4)}) (TlBAr(F)) affords the cationic bis(arylamino)phosphenium compounds [PN(Ar)CH(2)CH(2)N(Ar)] (A), (4a-e; A = OTf, BAr(F)), in high yield. Phosphenium cations 4a-d reversibly form adducts with trimethylphosphine. The structure of the phosphinophosphenium adduct 5c (Ar = 2,6-(CHMe(2))(2)-C(6)H(3)) has been determined by single-crystal X-ray diffraction techniques, revealing both the steric influences of the 2,6-Ar substituents and the electronic nature of the bonding in 5. Treatment of Wilkinson's catalyst, RhCl(PPh(3))(3), with 1 equiv of 4a gives the first well-defined Rh phosphenium complex, {trans-RhCl(PPh(3))(2)[PN(4-MeO-C(6)H(4))CH(2)CH(2)N(4-MeO-C(6)H(4))]}(OTf) (6), which is isolated in 80% yield. In contrast, treatment, of Wilkinson's catalyst with 4c results in quantitative formation of [Rh(PPh(3))(3)](OTf) and chlorophosphine 3c. The influence of the phosphenium N-Ar substituents is further evidenced by the analogous reaction between RhCl(PPh(3))(3) and mesityl-substituted 4b, which affords products analogous to 4a,c as well as the isomeric Rh phosphenium complex 7a, having cis PPh(3) ligands. (31)P NMR spectroscopic parameters for 6 and 7a,b are consistent with Rh-P multiple bonding. C1 Los Alamos Natl Lab, Div Chem, Los Alamos, NM 87545 USA. RP Baker, RT (reprint author), Los Alamos Natl Lab, Div Chem, Los Alamos, NM 87545 USA. RI Scott, Brian/D-8995-2017 OI Scott, Brian/0000-0003-0468-5396 NR 83 TC 95 Z9 95 U1 1 U2 8 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0276-7333 J9 ORGANOMETALLICS JI Organometallics PD NOV 27 PY 2000 VL 19 IS 24 BP 4944 EP 4956 DI 10.1021/om0005351 PG 13 WC Chemistry, Inorganic & Nuclear; Chemistry, Organic SC Chemistry GA 378ZU UT WOS:000165617100006 ER PT J AU Affolder, T Akimoto, H Akopian, A Albrow, MG Amaral, P Amendolia, SR Amidei, D Anikeev, K Antos, J Apollinari, G Arisawa, T Asakawa, T Ashmanskas, W Atac, M Azfar, F Azzi-Bacchetta, P Bacchetta, N Bailey, MW Bailey, S de Barbaro, P Barbaro-Galtieri, A Barnes, VE Barnett, BA Barone, M Bauer, G Bedeschi, F Belforte, S Bellettini, G Bellinger, J Benjamin, D Bensinger, J Beretvas, A Berge, JP Berryhill, J Bevensee, B Bhatti, A Binkley, M Bisello, D Blair, RE Blocker, C Bloom, K Blumenfeld, B Blusk, SR Bocci, A Bodek, A Bokhari, W Bolla, G Bonushkin, Y Bortoletto, D Boudreau, J Brandl, A van den Brink, S Bromberg, C Brozovic, M Bruner, N Buckley-Geer, E Budagov, J Budd, HS Burkett, K Busetto, G Byon-Wagner, A Byrum, KL Calafiura, P Campbell, M Carithers, W Carlson, J Carlsmith, D Cassada, J Castro, A Cauz, D Cerri, A Chan, AW Chang, PS Chang, PT Chapman, J Chen, C Chen, YC Cheng, MT Chertok, M Chiarelli, G Chirikov-Zorin, I Chlachidze, G Chlebana, F Christofek, L Chu, ML Chung, YS Ciobanu, CI Clark, AG Connolly, A Conway, J Cooper, J Cordelli, M Cranshaw, J Cronin-Hennessy, D Cropp, R Culbertson, R Dagenhart, D DeJongh, F Dell'Agnello, S Dell'Orso, M Demina, R Demortier, L Deninno, M Derwent, PF Devlin, T Dittmann, JR Donati, S Done, J Dorigo, T Eddy, N Einsweiler, K Elias, JE Engels, E Erdmann, W Errede, D Errede, S Fan, Q Feild, RG Ferretti, C Field, RD Fiori, I Flaugher, B Foster, GW Franklin, M Freeman, J Friedman, J Fukui, Y Galeotti, S Gallinaro, M Gao, T Garcia-Sciveres, M Garfinkel, AF Gatti, P Gay, C Geer, S Gerdes, DW Giannetti, P Giromini, P Glagolev, V Gold, M Goldstein, J Gordon, A Goshaw, AT Gotra, Y Goulianos, K Green, C Groer, L Grosso-Pilcher, C Guenther, M Guillian, G da Costa, JG Guo, RS Haas, RM Haber, C Hafen, E Hahn, SR Hall, C Handa, T Handler, R Hao, W Happacher, F Hara, K Hardman, AD Harris, RM Hartmann, F Hatakeyama, K Hauser, J Heinrich, J Heiss, A Herndon, M Hoffman, KD Holck, C Hollebeek, R Holloway, L Hughes, R Huston, J Huth, J Ikeda, H Incandela, J Introzzi, G Iwai, J Iwata, Y James, E Jensen, H Jones, M Joshi, U Kambara, H Kamon, T Kaneko, T Karr, K Kasha, H Kato, Y Keaffaber, TA Kelley, K Kelly, M Kennedy, RD Kephart, R Khazins, D Kikuchi, T Kilminster, B Kirby, M Kirk, M Kim, BJ Kim, DH Kim, HS Kim, MJ Kim, SH Kim, YK Kirsch, L Klimenko, S Koehn, P Kongeter, A Kondo, K Konigsberg, J Kordas, K Korn, A Korytov, A Kovacs, E Kroll, J Kruse, M Kuhlmann, SE Kurino, K Kuwabara, T Laasanen, AT Lai, N Lami, S Lammel, S Lamoureux, JI Lancaster, M Latino, G LeCompte, T Lee, AM Lee, K Leone, S Lewis, JD Lindgren, M Liss, TM Liu, JB Liu, YC Lockyer, N Loken, J Loreti, M Lucchesi, D Lukens, P Lusin, S Lyons, L Lys, J Madrak, R Maeshima, K Maksimovic, P Malferrari, L Mangano, M Mariotti, M Martignon, G Martin, A Matthews, JAJ Mayer, J Mazzanti, P McFarland, KS McIntyre, P McKigney, E Menguzzato, M Menzione, A Mesropian, C Moggi, N Moore, E Moore, R Morita, Y Mulhearn, M Mukherjee, A Muller, T Munar, A Murat, P Murgia, S Musy, M Nachtman, J Nahn, S Nakada, H Nakaya, T Nakano, I Nelson, C Neuberger, D Newman-Holmes, C Ngan, CYP Nicolaidi, P Niu, H Nodulman, L Nomerotski, A Oh, SH Ohmoto, T Ohsugi, T Oishi, R Okusawa, T Olsen, J Orejudos, W Pagliarone, C Palmonari, F Paoletti, R Papadimitriou, V Pappas, SP Partos, D Patrick, J Pauletta, G Paulini, M Paus, C Pescara, L Phillips, TJ Piacentino, G Pitts, KT Plunkett, R Pompos, A Pondrom, L Pope, G Popovic, M Prokoshin, F Proudfoot, J Ptohos, F Pukhov, O Punzi, G Ragan, K Rakitine, A Reher, D Reichold, A Riegler, W Ribon, A Rimondi, F Ristori, L Riveline, M Robertson, WJ Robinson, A Rodrigo, T Rolli, S Rosenson, L Roser, R Rossin, R Safonov, A Sakumoto, WK Saltzberg, D Sansoni, A Santi, L Sato, H Savard, P Schlabach, P Schmidt, EE Schmidt, MP Schmitt, M Scodellaro, L Scott, A Scribano, A Segler, S Seidel, S Seiya, Y Semenov, A Semeria, F Shah, T Shapiro, MD Shepard, PF Shibayama, T Shimojima, M Shochet, M Siegrist, J Signorelli, G Sill, A Sinervo, P Singh, P Slaughter, AJ Sliwa, K Smith, C Snider, FD Solodsky, A Spalding, J Speer, T Sphicas, P Spinella, F Spiropulu, M Spiegel, L Steele, J Stefanini, A Strologas, J Strumia, F Stuart, D Sumorok, K Suzuki, T Takano, T Takashima, R Takikawa, K Tamburello, P Tanaka, M Tannenbaum, B Taylor, W Tecchio, M Teng, PK Terashi, K Tether, S Theriot, D Thurman-Keup, R Tipton, P Tkaczyk, S Tollefson, K Tollestrup, A Toyoda, H Trischuk, W de Troconiz, JF Tseng, J Turini, N Ukegawa, F Vaiciulis, T Valls, J Vejcik, S Velev, G Vidal, R Vilar, R Volobouev, I Vucinic, D Wagner, RG Wagner, RL Wahl, J Wallace, NB Walsh, AM Wang, C Wang, CH Wang, MJ Watanabe, T Waters, D Watts, T Webb, R Wenzel, H Wester, WC Wicklund, AB Wicklund, E Williams, HH Wilson, P Winer, BL Winn, D Wolbers, S Wolinski, D Wolinski, J Wolinski, S Worm, S Wu, X Wyss, J Yagil, A Yao, W Yeh, GP Yeh, P Yoh, J Yosef, C Yoshida, T Yu, I Yu, S Yu, Z Zanetti, A Zetti, F Zucchelli, S AF Affolder, T Akimoto, H Akopian, A Albrow, MG Amaral, P Amendolia, SR Amidei, D Anikeev, K Antos, J Apollinari, G Arisawa, T Asakawa, T Ashmanskas, W Atac, M Azfar, F Azzi-Bacchetta, P Bacchetta, N Bailey, MW Bailey, S de Barbaro, P Barbaro-Galtieri, A Barnes, VE Barnett, BA Barone, M Bauer, G Bedeschi, F Belforte, S Bellettini, G Bellinger, J Benjamin, D Bensinger, J Beretvas, A Berge, JP Berryhill, J Bevensee, B Bhatti, A Binkley, M Bisello, D Blair, RE Blocker, C Bloom, K Blumenfeld, B Blusk, SR Bocci, A Bodek, A Bokhari, W Bolla, G Bonushkin, Y Bortoletto, D Boudreau, J Brandl, A van den Brink, S Bromberg, C Brozovic, M Bruner, N Buckley-Geer, E Budagov, J Budd, HS Burkett, K Busetto, G Byon-Wagner, A Byrum, KL Calafiura, P Campbell, M Carithers, W Carlson, J Carlsmith, D Cassada, J Castro, A Cauz, D Cerri, A Chan, AW Chang, PS Chang, PT Chapman, J Chen, C Chen, YC Cheng, MT Chertok, M Chiarelli, G Chirikov-Zorin, I Chlachidze, G Chlebana, F Christofek, L Chu, ML Chung, YS Ciobanu, CI Clark, AG Connolly, A Conway, J Cooper, J Cordelli, M Cranshaw, J Cronin-Hennessy, D Cropp, R Culbertson, R Dagenhart, D DeJongh, F Dell'Agnello, S Dell'Orso, M Demina, R Demortier, L Deninno, M Derwent, PF Devlin, T Dittmann, JR Donati, S Done, J Dorigo, T Eddy, N Einsweiler, K Elias, JE Engels, E Erdmann, W Errede, D Errede, S Fan, Q Feild, RG Ferretti, C Field, RD Fiori, I Flaugher, B Foster, GW Franklin, M Freeman, J Friedman, J Fukui, Y Galeotti, S Gallinaro, M Gao, T Garcia-Sciveres, M Garfinkel, AF Gatti, P Gay, C Geer, S Gerdes, DW Giannetti, P Giromini, P Glagolev, V Gold, M Goldstein, J Gordon, A Goshaw, AT Gotra, Y Goulianos, K Green, C Groer, L Grosso-Pilcher, C Guenther, M Guillian, G da Costa, JG Guo, RS Haas, RM Haber, C Hafen, E Hahn, SR Hall, C Handa, T Handler, R Hao, W Happacher, F Hara, K Hardman, AD Harris, RM Hartmann, F Hatakeyama, K Hauser, J Heinrich, J Heiss, A Herndon, M Hoffman, KD Holck, C Hollebeek, R Holloway, L Hughes, R Huston, J Huth, J Ikeda, H Incandela, J Introzzi, G Iwai, J Iwata, Y James, E Jensen, H Jones, M Joshi, U Kambara, H Kamon, T Kaneko, T Karr, K Kasha, H Kato, Y Keaffaber, TA Kelley, K Kelly, M Kennedy, RD Kephart, R Khazins, D Kikuchi, T Kilminster, B Kirby, M Kirk, M Kim, BJ Kim, DH Kim, HS Kim, MJ Kim, SH Kim, YK Kirsch, L Klimenko, S Koehn, P Kongeter, A Kondo, K Konigsberg, J Kordas, K Korn, A Korytov, A Kovacs, E Kroll, J Kruse, M Kuhlmann, SE Kurino, K Kuwabara, T Laasanen, AT Lai, N Lami, S Lammel, S Lamoureux, JI Lancaster, M Latino, G LeCompte, T Lee, AM Lee, K Leone, S Lewis, JD Lindgren, M Liss, TM Liu, JB Liu, YC Lockyer, N Loken, J Loreti, M Lucchesi, D Lukens, P Lusin, S Lyons, L Lys, J Madrak, R Maeshima, K Maksimovic, P Malferrari, L Mangano, M Mariotti, M Martignon, G Martin, A Matthews, JAJ Mayer, J Mazzanti, P McFarland, KS McIntyre, P McKigney, E Menguzzato, M Menzione, A Mesropian, C Moggi, N Moore, E Moore, R Morita, Y Mulhearn, M Mukherjee, A Muller, T Munar, A Murat, P Murgia, S Musy, M Nachtman, J Nahn, S Nakada, H Nakaya, T Nakano, I Nelson, C Neuberger, D Newman-Holmes, C Ngan, CYP Nicolaidi, P Niu, H Nodulman, L Nomerotski, A Oh, SH Ohmoto, T Ohsugi, T Oishi, R Okusawa, T Olsen, J Orejudos, W Pagliarone, C Palmonari, F Paoletti, R Papadimitriou, V Pappas, SP Partos, D Patrick, J Pauletta, G Paulini, M Paus, C Pescara, L Phillips, TJ Piacentino, G Pitts, KT Plunkett, R Pompos, A Pondrom, L Pope, G Popovic, M Prokoshin, F Proudfoot, J Ptohos, F Pukhov, O Punzi, G Ragan, K Rakitine, A Reher, D Reichold, A Riegler, W Ribon, A Rimondi, F Ristori, L Riveline, M Robertson, WJ Robinson, A Rodrigo, T Rolli, S Rosenson, L Roser, R Rossin, R Safonov, A Sakumoto, WK Saltzberg, D Sansoni, A Santi, L Sato, H Savard, P Schlabach, P Schmidt, EE Schmidt, MP Schmitt, M Scodellaro, L Scott, A Scribano, A Segler, S Seidel, S Seiya, Y Semenov, A Semeria, F Shah, T Shapiro, MD Shepard, PF Shibayama, T Shimojima, M Shochet, M Siegrist, J Signorelli, G Sill, A Sinervo, P Singh, P Slaughter, AJ Sliwa, K Smith, C Snider, FD Solodsky, A Spalding, J Speer, T Sphicas, P Spinella, F Spiropulu, M Spiegel, L Steele, J Stefanini, A Strologas, J Strumia, F Stuart, D Sumorok, K Suzuki, T Takano, T Takashima, R Takikawa, K Tamburello, P Tanaka, M Tannenbaum, B Taylor, W Tecchio, M Teng, PK Terashi, K Tether, S Theriot, D Thurman-Keup, R Tipton, P Tkaczyk, S Tollefson, K Tollestrup, A Toyoda, H Trischuk, W de Troconiz, JF Tseng, J Turini, N Ukegawa, F Vaiciulis, T Valls, J Vejcik, S Velev, G Vidal, R Vilar, R Volobouev, I Vucinic, D Wagner, RG Wagner, RL Wahl, J Wallace, NB Walsh, AM Wang, C Wang, CH Wang, MJ Watanabe, T Waters, D Watts, T Webb, R Wenzel, H Wester, WC Wicklund, AB Wicklund, E Williams, HH Wilson, P Winer, BL Winn, D Wolbers, S Wolinski, D Wolinski, J Wolinski, S Worm, S Wu, X Wyss, J Yagil, A Yao, W Yeh, GP Yeh, P Yoh, J Yosef, C Yoshida, T Yu, I Yu, S Yu, Z Zanetti, A Zetti, F Zucchelli, S CA CDF Collaboration TI Measurement of the decay amplitudes of B-0 -> J/psi K*(0) and B-S(0) -> J/psi phi decays SO PHYSICAL REVIEW LETTERS LA English DT Article ID TOP-QUARK PRODUCTION; B-DECAYS; (P)OVER-BAR-P COLLISIONS; ANGULAR-DISTRIBUTIONS; FORM-FACTORS; D-MESONS; FACTORIZATION; ASYMMETRIES; B->VV; NONFACTORIZATION AB An angular analysis of B-0 --> J/psi K*(0) and B-s(0) --> J/psi phi has been used to determine the decay amplitudes with parity-even longitudinal (A(0)) and transverse (A(\ \)) polarization and parity-odd transverse (A1(-)) polarization. The measurements are based on 190 B-0 and 40 B-s(0) candidates obtained from 89 pb(-1) of (p) over barp collisions at the Fermilab Tevatron. The longitudinal decay amplitude dominates with \A(0)\(2) = 0.59 +/- 0.06 +/- 0.01 for B-0 and \A(0)\ (2) = 0.61 +/- 0.14 +/- 0.02 for B-s(0) decays. The parity-odd amplitude is found to be small with \A1(-)\(2) = 0.13(-0.09)(+0.12) +/- 0.06 for B-0 and \A1(-)\ = 0.23 +/- 0.19 +/- 0.04 for B-s(0) decays. C1 Acad Sinica, Inst Phys, Taipei 11529, Taiwan. Argonne Natl Lab, Argonne, IL 60439 USA. Univ Bologna, Ist Nazl Fis Nucl, I-40127 Bologna, Italy. Brandeis Univ, Waltham, MA 02254 USA. Univ Calif Los Angeles, Los Angeles, CA 90024 USA. Univ Cantabria, CSIC, Inst Fis, E-39005 Santander, Spain. Univ Chicago, Enrico Fermi Inst, Chicago, IL 60637 USA. Joint Inst Nucl Res, RU-141980 Dubna, Russia. Duke Univ, Durham, NC 27708 USA. Fermilab Natl Accelerator Lab, Batavia, IL 60510 USA. Univ Florida, Gainesville, FL 32611 USA. Ist Nazl Fis Nucl, Lab Nazl Frascati, I-00044 Frascati, Italy. Univ Geneva, CH-1211 Geneva 4, Switzerland. Harvard Univ, Cambridge, MA 02138 USA. Hiroshima Univ, Higashihiroshima 724, Japan. Univ Illinois, Urbana, IL 61801 USA. Johns Hopkins Univ, Baltimore, MD 21218 USA. Univ Karlsruhe, Inst Expt Kernphys, D-76128 Karlsruhe, Germany. Kyungpook Natl Univ, Korean Hadron Collider Lab, Taegu 702701, South Korea. Seoul Natl Univ, Seoul 151742, South Korea. Sungkyunkwan Univ, Suwon 440746, South Korea. High Energy Accelerator Res Org, Tsukuba, Ibaraki 305, Japan. Ernest Orlando Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. MIT, Cambridge, MA 02139 USA. McGill Univ, Inst Particle Phys, Montreal, PQ H3A 2T8, Canada. Univ Toronto, Toronto, ON M5S 1A7, Canada. Univ Michigan, Ann Arbor, MI 48109 USA. Michigan State Univ, E Lansing, MI 48824 USA. Univ New Mexico, Albuquerque, NM 87131 USA. Ohio State Univ, Columbus, OH 43210 USA. Osaka City Univ, Osaka 588, Japan. Univ Oxford, Oxford OX1 3RH, England. Univ Padua, Ist Nazl Fis Nucl, Sez Padova, I-35131 Padua, Italy. Univ Penn, Philadelphia, PA 19104 USA. Univ Pisa, Ist Nazl Fis Nucl, I-56100 Pisa, Italy. Scuola Normale Super Pisa, I-56100 Pisa, Italy. Univ Pittsburgh, Pittsburgh, PA 15260 USA. Purdue Univ, W Lafayette, IN 47907 USA. Univ Rochester, Rochester, NY 14627 USA. Rockefeller Univ, New York, NY 10021 USA. Rutgers State Univ, Piscataway, NJ 08855 USA. Texas A&M Univ, College Stn, TX 77843 USA. Texas Tech Univ, Lubbock, TX 79409 USA. Univ Trieste, Ist Nazl Fis Nucl, I-34127 Trieste, Italy. Univ Udine, Ist Nazl Fis Nucl, I-33100 Udine, Italy. Univ Tsukuba, Tsukuba, Ibaraki 305, Japan. Tufts Univ, Medford, MA 02155 USA. Waseda Univ, Tokyo 169, Japan. Univ Wisconsin, Madison, WI 53706 USA. Yale Univ, New Haven, CT 06520 USA. RP Affolder, T (reprint author), Acad Sinica, Inst Phys, Taipei 11529, Taiwan. RI Prokoshin, Fedor/E-2795-2012; Lancaster, Mark/C-1693-2008; Vucinic, Dejan/C-2406-2008; Azzi, Patrizia/H-5404-2012; Punzi, Giovanni/J-4947-2012; Chiarelli, Giorgio/E-8953-2012; Scodellaro, Luca/K-9091-2014; Paulini, Manfred/N-7794-2014; Introzzi, Gianluca/K-2497-2015 OI Prokoshin, Fedor/0000-0001-6389-5399; Azzi, Patrizia/0000-0002-3129-828X; Punzi, Giovanni/0000-0002-8346-9052; Chiarelli, Giorgio/0000-0001-9851-4816; Scodellaro, Luca/0000-0002-4974-8330; Paulini, Manfred/0000-0002-6714-5787; Introzzi, Gianluca/0000-0002-1314-2580 NR 27 TC 38 Z9 38 U1 0 U2 7 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD NOV 27 PY 2000 VL 85 IS 22 BP 4668 EP 4673 DI 10.1103/PhysRevLett.85.4668 PG 6 WC Physics, Multidisciplinary SC Physics GA 377ZP UT WOS:000165556600007 ER PT J AU Anciant, E Auger, T Audit, G Battaglieri, M Laget, JM Marchand, C Adams, GS Amaryan, MJ Anghinolfi, M Armstrong, D Asavapibhop, B Avakian, H Barrow, S Beard, K Bektasoglu, M Berman, BL Bianchi, N Biselli, A Boiarinov, S Briscoe, WJ Brooks, WK Burkert, VD Calarco, JR Capitani, G Carman, DS Carnahan, B Cetina, C Cole, PL Coleman, A Connelly, J Cords, D Corvisiero, P Crabb, D Crannell, H Cummings, J Degtyarneko, PV Dennis, LC De Sanctis, E De Vita, R Dhuga, KS Djalali, C Dodge, GE Doughty, D Dragovitsch, P Dugger, M Dytman, S Efremenko, YV Egiyan, H Egiyan, KS Elouadrhiri, L Farhi, L Feuerbach, RJ Ficenec, J Forest, TA Freyberger, A Funsten, H Gai, M Garcon, M Gilfoyle, GP Giovanetti, K Girard, P Griffioen, KA Guidal, M Gyurjyan, V Heddle, D Hersman, FW Hicks, K Hicks, RS Holtrop, M Hyde-Wright, CE Ito, MM Jenkins, D Joo, K Khandaker, M Kim, DH Kim, W Klein, A Klein, FJ Klusman, M Kossov, M Kramer, LH Kuhn, SE Lawrence, D Longhi, A Loukachine, K Magahiz, R Major, RW Manak, JJ Matthews, SK McAleer, S McCarthy, J McCormick, K McNabb, JWC Mecking, BA Mestayer, MD Meyer, CA Minehart, R Miskimen, R Muccifora, V Mueller, J Murphy, L Mutchler, GS Napolitano, J Niyazov, RA Opper, A O'Brien, JT Philips, S Pivnyuk, N Pocanic, D Pogorelko, O Polli, E Preedom, BM Price, JW Qin, LM Raue, BA Reolon, AR Riccardi, G Ricco, G Ripani, M Ritchie, BG Ronchetti, F Rossi, P Roudot, F Rowntree, D Rubin, PD Salgado, CW Sapunenko, V Schumacher, RA Shafi, A Sharabian, YG Skabelin, A Smith, C Smith, ES Sober, DI Stepanyan, S Stoler, P Taiuti, M Taylor, S Tedeschi, D Thompson, R Vineyard, MF Vlassov, A Weller, H Weinstein, LB Welsh, R Weygand, D Whisnant, S Witkowski, M Wolin, E Yegneswaran, A Yun, J Zhang, B Zhao, J AF Anciant, E Auger, T Audit, G Battaglieri, M Laget, JM Marchand, C Adams, GS Amaryan, MJ Anghinolfi, M Armstrong, D Asavapibhop, B Avakian, H Barrow, S Beard, K Bektasoglu, M Berman, BL Bianchi, N Biselli, A Boiarinov, S Briscoe, WJ Brooks, WK Burkert, VD Calarco, JR Capitani, G Carman, DS Carnahan, B Cetina, C Cole, PL Coleman, A Connelly, J Cords, D Corvisiero, P Crabb, D Crannell, H Cummings, J Degtyarneko, PV Dennis, LC De Sanctis, E De Vita, R Dhuga, KS Djalali, C Dodge, GE Doughty, D Dragovitsch, P Dugger, M Dytman, S Efremenko, YV Egiyan, H Egiyan, KS Elouadrhiri, L Farhi, L Feuerbach, RJ Ficenec, J Forest, TA Freyberger, A Funsten, H Gai, M Garcon, M Gilfoyle, GP Giovanetti, K Girard, P Griffioen, KA Guidal, M Gyurjyan, V Heddle, D Hersman, FW Hicks, K Hicks, RS Holtrop, M Hyde-Wright, CE Ito, MM Jenkins, D Joo, K Khandaker, M Kim, DH Kim, W Klein, A Klein, FJ Klusman, M Kossov, M Kramer, LH Kuhn, SE Lawrence, D Longhi, A Loukachine, K Magahiz, R Major, RW Manak, JJ Matthews, SK McAleer, S McCarthy, J McCormick, K McNabb, JWC Mecking, BA Mestayer, MD Meyer, CA Minehart, R Miskimen, R Muccifora, V Mueller, J Murphy, L Mutchler, GS Napolitano, J Niyazov, RA Opper, A O'Brien, JT Philips, S Pivnyuk, N Pocanic, D Pogorelko, O Polli, E Preedom, BM Price, JW Qin, LM Raue, BA Reolon, AR Riccardi, G Ricco, G Ripani, M Ritchie, BG Ronchetti, F Rossi, P Roudot, F Rowntree, D Rubin, PD Salgado, CW Sapunenko, V Schumacher, RA Shafi, A Sharabian, YG Skabelin, A Smith, C Smith, ES Sober, DI Stepanyan, S Stoler, P Taiuti, M Taylor, S Tedeschi, D Thompson, R Vineyard, MF Vlassov, A Weller, H Weinstein, LB Welsh, R Weygand, D Whisnant, S Witkowski, M Wolin, E Yegneswaran, A Yun, J Zhang, B Zhao, J CA CLAS Collaboration TI Photoproduction of phi (1020) masons on the proton at large momentum transfer SO PHYSICAL REVIEW LETTERS LA English DT Article ID EXCHANGE-POTENTIAL APPROACH; BARYON-BARYON SCATTERING; NUCLEON; MESONS AB The cross section for phi meson photoproduction on the proton has been measured for the first time up to a four-momentum transfer -t = 4 GeV2, using the CLAS detector at the Thomas Jefferson National Accelerator Facility. At low four-momentum transfer, the differential cross section is well described by Pomeron exchange. At large four-momentum transfer, above -t = 1.8 GeV2, the data:support a model where the Pomeron is resolved into its simplest component, two gluons, which may couple to any quark in the proton and in the phi. C1 CEA Saclay, SPhN, DAPNIA, F-91191 Gif Sur Yvette, France. Univ Genoa, Ist Nazl Fis Nucl, Sez Genova, I-16146 Genoa, Italy. Univ Genoa, Ist Nazl Fis Nucl, Dipartimento Fis, I-16146 Genoa, Italy. Arizona State Univ, Dept Phys & Astron, Tempe, AZ 85287 USA. Carnegie Mellon Univ, Dept Phys, Pittsburgh, PA 15213 USA. Catholic Univ Amer, Dept Phys, Washington, DC 20064 USA. Christopher Newport Univ, Newport News, VA 23606 USA. Coll William & Mary, Dept Phys, Williamsburg, VA 23187 USA. Univ Edinburgh, Dept Phys & Astron, Edinburgh EH9 3JZ, Midlothian, Scotland. Duke Univ, Durham, NC 27706 USA. Florida State Univ, Dept Phys, Tallahassee, FL 32306 USA. Florida Int Univ, Miami, FL 33199 USA. George Washington Univ, Dept Phys, Washington, DC 20052 USA. Inst Phys Nucl, IN2P3, F-91406 Orsay, France. Inst Theoret & Expt Phys, Moscow 117259, Russia. James Madison Univ, Dept Phys, Harrisonburg, VA 22807 USA. Kyungpook Natl Univ, Dept Phys, Taegu 702701, South Korea. Ist Nazl Fis Nucl, Lab Nazl Frascati, I-00044 Frascati, Italy. MIT, Bates Linear Accelerator, Middleton, MA 01949 USA. Norfolk State Univ, Norfolk, VA 23504 USA. Ohio Univ, Dept Phys, Athens, OH 45701 USA. Old Dominion Univ, Dept Phys, Norfolk, VA 23529 USA. Rensselaer Polytech Inst, Dept Phys, Troy, NY 12181 USA. Rice Univ, Bonner Lab, Houston, TX 77251 USA. Thomas Jefferson Natl Accelerator Facil, Newport News, VA 23606 USA. Univ Calif Los Angeles, Dept Phys, Los Angeles, CA 90095 USA. Univ Connecticut, Dept Phys, Storrs, CT 06269 USA. Univ Massachusetts, Dept Phys, Amherst, MA 01003 USA. Univ New Hampshire, Dept Phys, Durham, NH 03824 USA. Univ Pittsburgh, Dept Phys, Pittsburgh, PA 15260 USA. Univ Richmond, Dept Phys, Richmond, VA 23173 USA. Univ S Carolina, Dept Phys, Columbia, SC 29208 USA. Univ Texas, Dept Phys, El Paso, TX 79968 USA. Univ Virginia, Dept Phys, Charlottesville, VA 22903 USA. Virginia Polytech Inst & State Univ, Dept Phys, Blacksburg, VA 24061 USA. Yerevan Phys Inst, Yerevan 375036, Armenia. RP Anciant, E (reprint author), CEA Saclay, SPhN, DAPNIA, F-91191 Gif Sur Yvette, France. RI Bektasoglu, Mehmet/A-2074-2012; riccardi, gabriele/A-9269-2012; Brooks, William/C-8636-2013; Schumacher, Reinhard/K-6455-2013; Meyer, Curtis/L-3488-2014; OI Brooks, William/0000-0001-6161-3570; Schumacher, Reinhard/0000-0002-3860-1827; Meyer, Curtis/0000-0001-7599-3973; Sapunenko, Vladimir/0000-0003-1877-9043 NR 27 TC 79 Z9 80 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 NOV 27 PY 2000 VL 85 IS 22 BP 4682 EP 4686 DI 10.1103/PhysRevLett.85.4682 PG 5 WC Physics, Multidisciplinary SC Physics GA 377ZP UT WOS:000165556600010 ER PT J AU Batista, CD Ortiz, G AF Batista, CD Ortiz, G TI Quantum phase diagram of the t-J(z) chain model SO PHYSICAL REVIEW LETTERS LA English DT Article ID SYSTEMS AB We present the quantum phase diagram of the one-dimensional t-J(z) model for arbitrary spin (integer or half-integer) and sign of the spin-spin interaction J(z), using an exact mapping to a spinless fermion model that can be solved exactly using the Bethe ansatz. We discuss: its superconducting phase as a function of hole doping nu. Motivated by the new paradigm of high temperature superconductivity, the stripe phase, we also consider the effect the antiferromagnetic background has on the t-J(z) chain intended to mimic the stripe segments. C1 Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. RP Batista, CD (reprint author), Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. RI Batista, Cristian/J-8008-2016 NR 16 TC 21 Z9 21 U1 0 U2 1 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 EI 1079-7114 J9 PHYS REV LETT JI Phys. Rev. Lett. PD NOV 27 PY 2000 VL 85 IS 22 BP 4755 EP 4758 DI 10.1103/PhysRevLett.85.4755 PG 4 WC Physics, Multidisciplinary SC Physics GA 377ZP UT WOS:000165556600028 ER PT J AU Valla, T Fedorov, AV Johnson, PD Xue, J Smith, KE DiSalvo, FJ AF Valla, T Fedorov, AV Johnson, PD Xue, J Smith, KE DiSalvo, FJ TI Charge-density-wave-induced modifications to the quasiparticle self-energy in 2H-TaSe2 SO PHYSICAL REVIEW LETTERS LA English DT Article ID NEUTRON-SCATTERING; PHOTOEMISSION; YBA2CU3O7; MECHANISM; 2H-NBSE2; PHONON; SYSTEM AB The self-energy of the photohole in 2H-TaSe2 is measured by angle-resolved photoemission spectroscopy as a function:of binding energy and temperature. In the charge-density wave (CDW) state, a structure in the self-energy is detected at similar to 65 meV that cannot be explained by electron-phonon scattering. A reduction in the scattering rates below this energy indicates the collapse of a major scattering channel with the formation of the CDW,state accompanying the appearance of a bosonic "mode" in the excitation spectrum of the system. C1 Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. Boston Univ, Dept Phys, Boston, MA 02215 USA. Cornell Univ, Baker Lab, Dept Chem, Ithaca, NY 14853 USA. RP Valla, T (reprint author), Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. NR 22 TC 53 Z9 53 U1 1 U2 22 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 NOV 27 PY 2000 VL 85 IS 22 BP 4759 EP 4762 DI 10.1103/PhysRevLett.85.4759 PG 4 WC Physics, Multidisciplinary SC Physics GA 377ZP UT WOS:000165556600029 ER PT J AU Mizokawa, T Kim, C Shen, ZX Ino, A Yoshida, T Fujimori, A Goto, M Eisaki, H Uchida, S Tagami, M Yoshida, K Rykov, AI Siohara, Y Tomimoto, K Tajima, S Yamada, Y Horii, S Yamada, N Yamada, Y Hirabayashi, I AF Mizokawa, T Kim, C Shen, ZX Ino, A Yoshida, T Fujimori, A Goto, M Eisaki, H Uchida, S Tagami, M Yoshida, K Rykov, AI Siohara, Y Tomimoto, K Tajima, S Yamada, Y Horii, S Yamada, N Yamada, Y Hirabayashi, I TI Angle-resolved photoemission study of insulating and metallic Cu-O chains in PrBa2Cu3O7 and PrBa2Cu4O8 SO PHYSICAL REVIEW LETTERS LA English DT Article ID NORMAL-STATE PROPERTIES; SPIN-CHARGE SEPARATION; UNTWINNED PRBA2CU3O7; ELECTRONIC-STRUCTURE; SPECTRAL PROPERTIES; FERMI-SURFACE; MODEL; LI0.9MO6O17; EXCITATIONS; COMPOUND AB We compare the angle-resolved photoemission spectra of the hole-doped Cu-O; chains in PrBa2Cu3O7 (Pr123) and in PrBa2Cu4O8 (Pr124). While, in Pr123,: a dispersive feature from the chain takes a band maximum at k(b) (momentum along the chain) similar to pi /4 and loses its spectral weight around the Fermi level, it reaches the Fermi level at k(b) similar to pi /4 in Pr124. Although the chains in Pr123 and Pr124 are approximately 1/4 filled, they show contrasting behaviors: While the chains in Pr123 have an instability to charge ordering, those in Pr124 avoid it and show an interesting spectral feature of a metallic coupled-chain system. C1 Univ Tokyo, Dept Complex Sci & Engn, Bunkyo Ku, Tokyo 1130033, Japan. Stanford Univ, Dept Appl Phys, Stanford, CA 94305 USA. Stanford Univ, Stanford Synchrotron Radiat Lab, Stanford, CA 94305 USA. Univ Tokyo, Dept Phys, Bunkyo Ku, Tokyo 1130033, Japan. Univ Tokyo, Dept Superconduct, Bunkyo Ku, Tokyo 1130033, Japan. Univ Tokyo, Dept Adv Mat, Bunkyo Ku, Tokyo 1130033, Japan. Int Superconduct Technol Ctr, Superconduct Res Lab, Koto Ku, Tokyo 1350062, Japan. Shimane Univ, Fac Sci & Engn, Matsue, Shimane 6900823, Japan. Univ Electrocommun, Dept Appl Phys & Chem, Chofu, Tokyo 1828585, Japan. RP Mizokawa, T (reprint author), Univ Tokyo, Dept Complex Sci & Engn, Bunkyo Ku, Tokyo 1130033, Japan. RI HORII, SHIGERU/B-4703-2009; Mizokawa, Takashi/E-3302-2015 OI Mizokawa, Takashi/0000-0002-7682-2348 NR 28 TC 32 Z9 32 U1 0 U2 1 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD NOV 27 PY 2000 VL 85 IS 22 BP 4779 EP 4782 DI 10.1103/PhysRevLett.85.4779 PG 4 WC Physics, Multidisciplinary SC Physics GA 377ZP UT WOS:000165556600034 ER PT J AU Zheludev, A Kenzelmann, M Raymond, S Ressouche, E Masuda, T Kakurai, K Maslov, S Tsukada, I Uchinokura, K Wildes, A AF Zheludev, A Kenzelmann, M Raymond, S Ressouche, E Masuda, T Kakurai, K Maslov, S Tsukada, I Uchinokura, K Wildes, A TI Energy separation of single-particle and continuum states in an S=1/2 weakly coupled chains antiferromagnet SO PHYSICAL REVIEW LETTERS LA English DT Article ID 2-DIMENSIONAL HEISENBERG-ANTIFERROMAGNET; ZERO TEMPERATURE; DYNAMICS; KCUF3; SPINONS; PHASE AB Inelastic neutron scattering is used to study transverse-polarized magnetic excitations in the quasi-one-dimensional S = 1/2 antiferromagnet BaCu2Si2O7, where the saturation value for the Neel order parameter is mo = 0.12 mu (B) per spin. At: low energies the spectrum is totally dominated by resolution-limited spin-wave-like excitations. An excitation continuum sets in above a well-defined threshold frequency. Experimental results are discussed in the context of current theories for weakly interacting quantum half-integer-spin chains. C1 Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. Univ Oxford, Clarendon Lab, Oxford Phys, Oxford OX1 3PU, England. CENG, MDN, SPSMS, DRFMC, F-38054 Grenoble, France. Univ Tokyo, Dept Appl Phys, Bunkyo Ku, Tokyo 1138656, Japan. Univ Tokyo, Inst Solid State Phys, Neutron Scattering Lab, Tokai, Ibaraki 3191106, Japan. Inst Max Von Laue Paul Langevin, Grenoble 9, France. RP Tsukada, I (reprint author), Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. RI Maslov, Sergei/C-2397-2009; Kenzelmann, Michel/A-8438-2008 OI Maslov, Sergei/0000-0002-3701-492X; Kenzelmann, Michel/0000-0001-7913-4826 NR 19 TC 41 Z9 41 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 NOV 27 PY 2000 VL 85 IS 22 BP 4799 EP 4802 DI 10.1103/PhysRevLett.85.4799 PG 4 WC Physics, Multidisciplinary SC Physics GA 377ZP UT WOS:000165556600039 ER PT J AU Bracht, H Haller, EE AF Bracht, H Haller, EE TI Comment on "Self-diffusion in silicon: Similarity between the properties of native point defects" SO PHYSICAL REVIEW LETTERS LA English DT Article C1 Univ Munster, Inst Mat Phys, D-48149 Munster, Germany. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Bracht, H (reprint author), Univ Munster, Inst Mat Phys, D-48149 Munster, Germany. NR 3 TC 13 Z9 13 U1 0 U2 3 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD NOV 27 PY 2000 VL 85 IS 22 BP 4835 EP 4835 DI 10.1103/PhysRevLett.85.4835 PG 1 WC Physics, Multidisciplinary SC Physics GA 377ZP UT WOS:000165556600048 ER PT J AU Moss, WC AF Moss, WC TI Comment on "Extreme electrostatic phenomena in a single sonoluminescing bubble" SO PHYSICAL REVIEW LETTERS LA English DT Article C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Moss, WC (reprint author), Univ Calif Lawrence Livermore Natl Lab, 7000 East Ave, Livermore, CA 94550 USA. NR 3 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 NOV 27 PY 2000 VL 85 IS 22 BP 4837 EP 4837 DI 10.1103/PhysRevLett.85.4837 PG 1 WC Physics, Multidisciplinary SC Physics GA 377ZP UT WOS:000165556600050 ER PT J AU Montalenti, F Ferrando, R AF Montalenti, F Ferrando, R TI Comment on "Scaling behavior of one-dimensional Pt chains migration on Pt(110)-(1x2) surface" [Phys. Lett. A 268 (2000) 413] SO PHYSICS LETTERS A LA English DT Editorial Material DE scaling relation; one-dimensional Pt chains; leapfrog diffusion mechanism; cluster displacement rate ID DIFFUSION; MECHANISMS; CLUSTERS AB We show that the recently proposed scaling laws [see G. Zhuang, W. Wang, Phys. Lett. A 268 (2000) 413] for chain diffusion on missing-row Pt(110) have no real meaning, since they cannot be extended outside the narrow chain-length range which has been considered by Zhuang and Wang. The only asymptotic scaling law gives a chain mobility which is inversely proportional to the chain length; however this asymptotic scaling behaviour is not physically important due to the occurrence of multiple upward promotions for long chains. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Univ Genoa, Dipartimento Fis, INFM, I-16146 Genoa, Italy. Univ Genoa, Dipartimento Fis, CNR, CFSBT, I-16146 Genoa, Italy. Univ Calif Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. RP Ferrando, R (reprint author), Univ Genoa, Dipartimento Fis, INFM, Via Dodecaneso 33, I-16146 Genoa, Italy. RI Montalenti, Francesco/A-7738-2010; Ferrando, Riccardo /C-4066-2011 OI Montalenti, Francesco/0000-0001-7854-8269; Ferrando, Riccardo /0000-0003-2750-9061 NR 10 TC 0 Z9 0 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0375-9601 J9 PHYS LETT A JI Phys. Lett. A PD NOV 27 PY 2000 VL 277 IS 3 BP 185 EP 187 DI 10.1016/S0375-9601(00)00707-6 PG 3 WC Physics, Multidisciplinary SC Physics GA 382XQ UT WOS:000165853000010 ER PT J AU Porter, GA Liaw, PK Tiegs, TN Wu, KH AF Porter, GA Liaw, PK Tiegs, TN Wu, KH TI Particle size reduction of NiTi shape-memory alloy powders SO SCRIPTA MATERIALIA LA English DT Article DE shape-memory alloy; powder processing; diffusion; phase transformations; scanning electron microscopy C1 Univ Tennessee, Dept Mat Sci & Engn, Knoxville, TN 37996 USA. Oak Ridge Natl Lab, Div Met & Ceram, Oak Ridge, TN 37831 USA. Florida Int Univ, Dept Mech Engn, Miami, FL 33174 USA. RP Porter, GA (reprint author), Univ Tennessee, Dept Mat Sci & Engn, Knoxville, TN 37996 USA. OI Porter, Glen/0000-0001-5598-4041 NR 7 TC 18 Z9 18 U1 0 U2 1 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 NOV 27 PY 2000 VL 43 IS 12 BP 1111 EP 1117 DI 10.1016/S1359-6462(00)00539-X PG 7 WC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Science & Technology - Other Topics; Materials Science; Metallurgy & Metallurgical Engineering GA 383QB UT WOS:000165892800010 ER PT J AU Kliakhandler, IL AF Kliakhandler, IL TI Inverse cascade in film flows SO JOURNAL OF FLUID MECHANICS LA English DT Article ID FREE-SURFACE FLOWS; SLIGHTLY INCLINED PLANE; FALLING-FILM; LIQUID-FILM; HIGH REYNOLDS; NONLINEAR EVOLUTION; SOLITARY WAVES; ELEMENT METHOD; VISCOUS-FLUID; STABILITY AB Developed interfacial dynamics of thin him flows with moderate Reynolds numbers exhibits a remarkable feature: the evolution is dominated by solitary-like pulses with a natural large wavelength between them. This phenomenon is robust and resembles the inverse energy cascade in two-dimensional turbulence. A new simple evolution equation is proposed to describe the film flow dynamics which captures such an inverse cascade. The equation combines the simplest kinematic nonlinearity with the exact linear term. The spectral kernel of the linear term is found from the numerical solution of the associated linear stability problem. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Dept Math, Berkeley, CA 94720 USA. RP Kliakhandler, IL (reprint author), Northwestern Univ, Dept Engn Sci & Appl Math, 2145 Sheridan Rd, Evanston, IL 60208 USA. NR 44 TC 5 Z9 7 U1 0 U2 1 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 NOV 25 PY 2000 VL 423 BP 205 EP 225 DI 10.1017/S0022112000001786 PG 21 WC Mechanics; Physics, Fluids & Plasmas SC Mechanics; Physics GA 376JP UT WOS:000165454700007 ER PT J AU Daly, GM Wright, D El-Shall, MS AF Daly, GM Wright, D El-Shall, MS TI Spectroscopy of acetonitrile (benzene)(n) clusters, n=1-3. Comparison with benzene clusters SO CHEMICAL PHYSICS LETTERS LA English DT Article ID BONDING ENERGIES; DIMER CATION; IONIZATION; SPECTRA; WATER; ASSOCIATION; MOLECULES; DYNAMICS; PROFILES; TOLUENE AB Well-resolved spectra of the small benzene clusters containing a single acetonitrile molecule (B(n)A) with n = 1-3 have been obtained by the tone-color) resonant two-photon ionization technique using benzene's B-2u <--A(1g)6(0)(1) spectral resonance, and compared with the spectra of neat benzene clusters. While only a single spectral feature is found for the benzene-acetonitrile (BA) complex, three distinct isomers are suggested for the B(2)A cluster, and two isomers for the B(3)A cluster. The R2PI spectra obtained, in conjunction with Monte-Carlo (MC) simulations and simple energetic arguments, provide a reasonably compelling picture of the dipole-containing nonpolar molecular cluster system. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Virginia Commonwealth Univ, Dept Chem, Richmond, VA 23284 USA. Brookhaven Natl Lab, Upton, NY 11973 USA. Purdue Pharma LP, Ardsley, NY 10502 USA. RP El-Shall, MS (reprint author), Virginia Commonwealth Univ, Dept Chem, Richmond, VA 23284 USA. RI El-Shall, M. Samy/K-8954-2012 OI El-Shall, M. Samy/0000-0002-1013-4948 NR 29 TC 7 Z9 7 U1 1 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0009-2614 J9 CHEM PHYS LETT JI Chem. Phys. Lett. PD NOV 24 PY 2000 VL 331 IS 1 BP 47 EP 56 DI 10.1016/S0009-2614(00)01107-6 PG 10 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 377LM UT WOS:000165515100009 ER PT J AU Detrich, HW Parker, SK Williams, RC Nogales, E Downing, KH AF Detrich, HW Parker, SK Williams, RC Nogales, E Downing, KH TI Cold adaptation of microtubule assembly and dynamics - Structural interpretation of primary sequence changes present in the alpha- and beta-tubulins of antarctic fishes SO JOURNAL OF BIOLOGICAL CHEMISTRY LA English DT Article ID PHENOL-CHLOROFORM EXTRACTION; SINGLE-STEP METHOD; LOW-TEMPERATURES; IN-VITRO; NOTOTHENIA-CORIICEPS; BRAIN TUBULIN; RNA ISOLATION; PROTEIN; EVOLUTION; ISOTYPES AB The microtubules of Antarctic fishes, unlike those of homeotherms, assemble at very low temperatures (-1.8 degreesC). The adaptations that enhance assembly of these microtubules are intrinsic to the tubulin dimer and reduce its critical concentration for polymerization at 0 degreesC to similar to0.9 mg/ml (Williams, R, C., Jr., Correia, J. J., and DeVries, A. L. (1985) Biochemistry 24, 2790-2798). Here we demonstrate that microtubules formed by pure brain tubulins of Antarctic fishes exhibit slow dynamics at both low (5 degreesC) and high (25 degreesC) temperatures; the rates of polymer growth and shortening and the frequencies of interconversion between these states are small relative to those observed for mammalian microtubules (37 degreesC). To investigate the contribution of tubulin primary sequence variation to the functional properties of the microtubules of Antarctic fishes, we have sequenced brain cDNAs that encode 9 alpha -tubulins and 4 beta -tubulins from the yellowbelly rockcod Notothenia coriiceps and 4 alpha -tubulins and 2 beta -tubulins from the ocellated icefish Chionodraco rastrospinosus. The tubulins of these fishes mere found to contain small sets of unique or rare residue substitutions that mapped to the lateral, interprotofilament surfaces or to the interiors of the alpha- and beta -polypeptides; longitudinal interaction surfaces are not altered in the fish tubulins. Four changes (A278T and S287T in alpha; S280G and A285S in beta) were present in the S7-H9 interprotofilament ''M'' loops of some monomers and would be expected to increase the flexibility of these regions. A fifth lateral substitution specific to the alpha -chain (M302L or M302F) may increase the hydrophobicity of the interprotofilament interaction. Two hydrophobic substitutions (alpha :S187A in helix H5 and beta :Y202F in sheet S6) may act to stabilize the monomers in conformations favorable to polymerization. We propose that cold adaptation of microtubule assembly in Antarctic fishes has occurred in part by evolutionary restructuring of the lateral surfaces and the cores of the tubulin monomers. C1 Northeastern Univ, Dept Biol, Boston, MA 02115 USA. Vanderbilt Univ, Dept Mol Biol, Nashville, TN 37235 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Life Sci, Berkeley, CA 94720 USA. RP Detrich, HW (reprint author), Northeastern Univ, Dept Biol, 414 Mugar Hall,360 Huntington Ave, Boston, MA 02115 USA. FU NIGMS NIH HHS [GM46033, GM25638] NR 54 TC 91 Z9 95 U1 1 U2 7 PU AMER SOC BIOCHEMISTRY MOLECULAR BIOLOGY INC PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814 USA SN 0021-9258 J9 J BIOL CHEM JI J. Biol. Chem. PD NOV 24 PY 2000 VL 275 IS 47 BP 37038 EP 37047 DI 10.1074/jbc.M005699200 PG 10 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA 378GY UT WOS:000165577700082 PM 10956651 ER PT J AU Schmid, AK Bartelt, NC Hwang, RQ AF Schmid, AK Bartelt, NC Hwang, RQ TI Alloying at surfaces by the migration of reactive two-dimensional islands SO SCIENCE LA English DT Article ID BROWNIAN-MOTION; SOLID-SURFACES; DIFFUSION; CLUSTERS; DROPLETS; PHASE AB We have studied the formation kinetics of the copper-tin alloy bronze when tin is deposited on the (111) surface of copper at room temperature. Low-energy electron microscopy and atomic-resolution scanning tunneling microscopy reveal that bronze forms on the surface by a complicated, unanticipated cooperative mechanism: Ordered two-dimensional tin islands containing several hundred thousand atoms spontaneously sweep across the surface, leaving bronze alloys in their tracks. We propose that this process, driven by surface free energy, is a version of the "camphor dance" observed on liquid surfaces, and should be a general mechanism of surface alloying when surface diffusion is faster than exchange into the substrate. C1 Sandia Natl Labs, Livermore, CA 94551 USA. RP Schmid, AK (reprint author), Sandia Natl Labs, Livermore, CA 94551 USA. NR 23 TC 74 Z9 75 U1 2 U2 23 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 NOV 24 PY 2000 VL 290 IS 5496 BP 1561 EP 1564 DI 10.1126/science.290.5496.1561 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 376EX UT WOS:000165446200046 PM 11090351 ER PT J AU Orth, K Xu, ZH Mudgett, MB Bao, ZQ Palmer, LE Bliska, JB Mangel, WF Staskawicz, B Dixon, JE AF Orth, K Xu, ZH Mudgett, MB Bao, ZQ Palmer, LE Bliska, JB Mangel, WF Staskawicz, B Dixon, JE TI Disruption of signaling by Yersinia effector YopJ, a ubiquitin-like protein protease SO SCIENCE LA English DT Article ID CAMPESTRIS PV VESICATORIA; AVIRULENCE GENE AVRRXV; NF-KAPPA-B; ALPHA PRODUCTION; DOWN-REGULATION; ACTIVATION; INHIBITION; SUPPRESSION; EXPRESSION; RESISTANCE AB Homologs of the Yersinia virulence effector YopJ are found in both plant and animal bacterial pathogens, as well as plant symbionts. These YopJ family members were shown to act as cysteine proteases. The catalytic triad of the protease was required for inhibition of the mitogen-activated protein kinase (MAPK) and nuclear factor kappaB (NF-kappaB) signaling in animal cells and for induction of Localized cell death in plants. The substrates for YopJ were shown to be highly conserved ubiquitin-like molecules, which are covalently added to numerous regulatory proteins. YopJ family members exert their pathogenic effect on cells by disrupting this posttranslational modification. C1 Univ Michigan, Dept Biol Chem, Ann Arbor, MI 48109 USA. Univ Calif Berkeley, Dept Plant & Microbial Biol, Berkeley, CA 94720 USA. SUNY Stony Brook, Sch Med, Dept Mol Genet & Microbiol, Stony Brook, NY 11794 USA. Brookhaven Natl Lab, Dept Biol, Upton, NY 11973 USA. RP Dixon, JE (reprint author), Univ Michigan, Dept Biol Chem, Ann Arbor, MI 48109 USA. FU NIAID NIH HHS [AI41599]; PHS HHS [18024] NR 25 TC 361 Z9 380 U1 1 U2 14 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 NOV 24 PY 2000 VL 290 IS 5496 BP 1594 EP 1597 DI 10.1126/science.290.5496.1594 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 376EX UT WOS:000165446200056 PM 11090361 ER PT J AU Onasch, TB McGraw, R Imre, D AF Onasch, TB McGraw, R Imre, D TI Temperature-dependent heterogeneous efflorescence of mixed ammonium sulfate/calcium carbonate particles SO JOURNAL OF PHYSICAL CHEMISTRY A LA English DT Article ID CIRRUS CLOUD FORMATION; ELECTROLYTE-SOLUTIONS; SULFATE AEROSOLS; WATER ACTIVITIES; SULFURIC-ACID; NUCLEATION; PHASE; DUST; DELIQUESCENCE; MODEL AB In this paper, we report observations on single internally mixed ammonium sulfate/calcium carbonate microparticles. Deliquescence and efflorescence relative humidities for this mixed system are reported. The slightly soluble.CaCO3 has a negligible effect on the deliquescence relative humidity and the concentration dependent water activities. Mixed particles at 298 K were observed to exist in two metastable Liquid states: (a) supersaturated with respect to both ammonium sulfate and calcium carbonate and (b) supersaturated with respect to ammonium sulfate and saturated with respect to a solid calcium carbonate inclusion. The efflorescence relative humidities differed greatly between the two cases. Solution droplets supersaturated with respect to both salts (no solid inclusion present) effloresced at the homogeneous efflorescence point of pure ammonium sulfate. In contrast, the presence of the calcium carbonate as a similar to 500 nm solid inclusion within the 15 mum solution droplets served as a catalyst for heterogeneous nucleation and the particle crystallized at similar to 50% relative humidity (RH), a full 13% RH higher than homogeneous efflorescence. A smaller calcium carbonate seed induced efflorescence at an intermediate 47% RH, indicating that the heterogeneous efflorescence rate is a function of the size of the inclusion The data are analyzed using classical nucleation theory to derive the free-energy barrier to nucleation, the size of the critical nucleus, and the contact parameter between ammonium sulfate and calcium carbonate. The results are compared with available literature. The heterogeneous efflorescence was also investigated as a function of temperature (210-298 K) and found to have only a slight temperature dependence, similar to previous homogeneous efflorescence observations. C1 Brookhaven Natl Lab, Dept Environm Sci, Div Atmospher Sci, Upton, NY 11973 USA. RP Brookhaven Natl Lab, Dept Environm Sci, Div Atmospher Sci, Upton, NY 11973 USA. EM imre@bnl.gov NR 49 TC 36 Z9 37 U1 0 U2 18 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 1089-5639 J9 J PHYS CHEM A JI J. Phys. Chem. A PD NOV 23 PY 2000 VL 104 IS 46 BP 10797 EP 10806 DI 10.1021/jp0024064 PG 10 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 379MR UT WOS:000165646800029 ER PT J AU DeBeer, S Randall, DW Nersissian, AM Valentine, JS Hedman, B Hodgson, KO Solomon, EI AF DeBeer, S Randall, DW Nersissian, AM Valentine, JS Hedman, B Hodgson, KO Solomon, EI TI X-ray absorption edge and EXAFS studies of the blue copper site in stellacyanin: Effects of axial amide coordination SO JOURNAL OF PHYSICAL CHEMISTRY B LA English DT Article ID ELECTRONIC-STRUCTURE; K-EDGE; ANGSTROM RESOLUTION; CRYSTAL-STRUCTURE; FINE-STRUCTURE; PSEUDOMONAS-AERUGINOSA; NITRITE REDUCTASE; SPECTRAL FEATURES; ACTIVE-SITE; PLASTOCYANIN AB The blue copper sites in Cucumis sativus stellacyanin and Rhus vernicifera stellacyanin have been investigated by X-ray absorption spectroscopy (XAS) in order to probe the effects of axial amide coordination. EXAFS results show a slight lengthening of the Cu-S(Cys) bond in both stellacyanins compared to the classic blue copper site in azurin. The 1s --> 3d transition in the Cu K-edge of stellacyanin is similar to0.5 eV lower in energy than those of the classic blue copper sites, consistent with a stronger ligand donor set. A configuration interaction (CI) model applied to the 1s --> 4p and 1s --> 4p + shakedown transitions in the edge predicts less covalent bonding for stellacyanin than for plastocyanin, which is attributed to a weaker thiolate bond. These studies demonstrate that the strength of the axial ligand interaction inversely affects the strength of the thiolate-copper bond. C1 Stanford Univ, Dept Chem, Stanford, CA 94305 USA. Univ Calif Los Angeles, Dept Chem & Biochem, Los Angeles, CA 90095 USA. Stanford Univ, Stanford Linear Accelerator Ctr, Stanford Synchrotron Radiat Lab, Stanford, CA 94309 USA. RP Hedman, B (reprint author), Stanford Univ, Dept Chem, Stanford, CA 94305 USA. RI Valentine, Joan/B-6665-2008; DeBeer, Serena/G-6718-2012 OI Valentine, Joan/0000-0002-7174-925X; NR 45 TC 27 Z9 27 U1 0 U2 9 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 NOV 23 PY 2000 VL 104 IS 46 BP 10814 EP 10819 DI 10.1021/jp001334d PG 6 WC Chemistry, Physical SC Chemistry GA 379MV UT WOS:000165647300012 ER PT J AU Airapetian, A Akopov, N Akushevich, I Amarian, M Arrington, J Aschenauer, EC Avakian, H Avakian, R Avetissian, A Avetissian, E Bailey, P Bains, B Baumgarten, C Beckmann, M Belostotski, S Bernreuther, S Bianchi, N Bottcher, H Borissov, A Bouwhuis, M Brack, J Brauksiepe, S Braun, B Bruckner, W Brull, A Budz, P Bulten, HJ Capitani, GP Carter, P Chumney, P Cisbani, E Court, GR Dalpiaz, PF De Leo, R De Nardo, L De Sanctis, E De Schepper, D Devitsin, E Huberts, PKAD Di Nezza, P Djordjadze, V Duren, M Dvoredsky, A Elbakian, G Ely, J Fantoni, A Fechtchenko, A Ferro-Luzzi, M Fiedler, K Filippone, BW Fischer, H Fox, B Franz, J Frullani, S Garber, Y Garibaldi, F Garutti, E Gavrilov, G Gharibyan, V Golendukhin, A Graw, G Grebeniouk, O Green, PW Greeniaus, LG Gute, A Haeberli, W Hartig, M Hasch, D Heesbeen, D Heinsius, FH Henoch, M Hertenberger, R Hesselink, W Hoffmann-Rothe, P Hofmann, G Holler, Y Holt, RJ Hommez, B Iarygin, G Iodice, M Izotov, A Jackson, HE Jgoun, A Jung, P Kaiser, R Kanesaka, J Kinney, E Kisselev, A Kitching, P Kobayashi, H Koch, N Konigsmann, K Kolster, H Korotkov, V Kotik, E Kozlov, V Krivokhijine, VG Kyle, G Lagamba, L Laziev, A Lenisa, P Lindemann, T Lorenzon, W Makins, NCR Martin, JW Marukyan, H Masoli, F McAndrew, M McIlhany, K McKeown, RD Menden, F Metz, A Meyners, N Mikloukho, O Miller, CA Milner, R Mitsyn, V Muccifora, V Mussa, R Nagatisev, A Nappi, E Naryshkin, Y Nass, A Negodaeva, K Nowak, WD O'Neill, TG Openshaw, R Ouyang, J Owen, BR Pate, SF Potashov, S Potterveld, DH Rakness, G Rappoport, V Redwine, R Reggiani, D Reolon, AR Ristinen, R Rith, K Robinson, D Ruh, M Ryckbosch, D Sakemi, Y Savin, I Scarlett, C Schafer, A Schill, C Schmidt, F Schnell, G Schuler, KP Schwind, A Seibert, J Seitz, B Shibata, TA Shin, T Shutov, V Simani, C Simon, A Sinram, K Steffens, E Steijger, JJM Stewart, J Stosslein, U Suetsugu, K Sutter, M Tallini, H Taroian, S Terkulov, A Tessarin, S Thomas, E Tipton, B Tytgat, M Urciuoli, GM van den Brand, JFJ van der Steenhoven, G van de Vyver, R van Hunen, JJ Vetterli, MC Vikhrov, V Vincter, MG Visser, J Volk, E Weiskopf, C Wendland, J Wilbert, J Wise, T Yen, S Yoneyama, S Zohrabian, H AF Airapetian, A Akopov, N Akushevich, I Amarian, M Arrington, J Aschenauer, EC Avakian, H Avakian, R Avetissian, A Avetissian, E Bailey, P Bains, B Baumgarten, C Beckmann, M Belostotski, S Bernreuther, S Bianchi, N Bottcher, H Borissov, A Bouwhuis, M Brack, J Brauksiepe, S Braun, B Bruckner, W Brull, A Budz, P Bulten, HJ Capitani, GP Carter, P Chumney, P Cisbani, E Court, GR Dalpiaz, PF De Leo, R De Nardo, L De Sanctis, E De Schepper, D Devitsin, E Huberts, PKAD Di Nezza, P Djordjadze, V Duren, M Dvoredsky, A Elbakian, G Ely, J Fantoni, A Fechtchenko, A Ferro-Luzzi, M Fiedler, K Filippone, BW Fischer, H Fox, B Franz, J Frullani, S Garber, Y Garibaldi, F Garutti, E Gavrilov, G Gharibyan, V Golendukhin, A Graw, G Grebeniouk, O Green, PW Greeniaus, LG Gute, A Haeberli, W Hartig, M Hasch, D Heesbeen, D Heinsius, FH Henoch, M Hertenberger, R Hesselink, W Hoffmann-Rothe, P Hofmann, G Holler, Y Holt, RJ Hommez, B Iarygin, G Iodice, M Izotov, A Jackson, HE Jgoun, A Jung, P Kaiser, R Kanesaka, J Kinney, E Kisselev, A Kitching, P Kobayashi, H Koch, N Konigsmann, K Kolster, H Korotkov, V Kotik, E Kozlov, V Krivokhijine, VG Kyle, G Lagamba, L Laziev, A Lenisa, P Lindemann, T Lorenzon, W Makins, NCR Martin, JW Marukyan, H Masoli, F McAndrew, M McIlhany, K McKeown, RD Menden, F Metz, A Meyners, N Mikloukho, O Miller, CA Milner, R Mitsyn, V Muccifora, V Mussa, R Nagatisev, A Nappi, E Naryshkin, Y Nass, A Negodaeva, K Nowak, WD O'Neill, TG Openshaw, R Ouyang, J Owen, BR Pate, SF Potashov, S Potterveld, DH Rakness, G Rappoport, V Redwine, R Reggiani, D Reolon, AR Ristinen, R Rith, K Robinson, D Ruh, M Ryckbosch, D Sakemi, Y Savin, I Scarlett, C Schafer, A Schill, C Schmidt, F Schnell, G Schuler, KP Schwind, A Seibert, J Seitz, B Shibata, TA Shin, T Shutov, V Simani, C Simon, A Sinram, K Steffens, E Steijger, JJM Stewart, J Stosslein, U Suetsugu, K Sutter, M Tallini, H Taroian, S Terkulov, A Tessarin, S Thomas, E Tipton, B Tytgat, M Urciuoli, GM van den Brand, JFJ van der Steenhoven, G van de Vyver, R van Hunen, JJ Vetterli, MC Vikhrov, V Vincter, MG Visser, J Volk, E Weiskopf, C Wendland, J Wilbert, J Wise, T Yen, S Yoneyama, S Zohrabian, H TI The Q(2)-dependence of the generalised Gerasimov-Drell-Hearn integral for the proton SO PHYSICS LETTERS B LA English DT Article DE deep inelastic scattering; sum rules; asymmetries; photoabsorption ID POLARIZED STRUCTURE FUNCTIONS; DEEP-INELASTIC SCATTERING; STRUCTURE FUNCTIONS G(1); SUM-RULE; SPIN STRUCTURE; RADIATIVE-CORRECTIONS; MUON SCATTERING; NUCLEON; NEUTRON; PARTICLES AB The dependence on Q(2) (the negative square of the 4-momentum of the exchanged virtual photon) of the generalised Gerasimov-Drell-Hearn integral for the proton has been measured in the range 1.2 GeV2 < Q(2) < 12 GeV2 by scattering longitudinally polarised positrons on a longitudinally polarised hydrogen gas target. The contributions of the nucleon-resonance and deep inelastic regions to this integral have been evaluated separately. The latter has been found to dominate for Q(2) > 3 GeV2, while both contributions are important at low Q(2). The total integral shows no significant deviation from a 1/Q(2) behaviour in the measured Q(2) range, and thus no sign of large effects due to either nucleon-resonance excitations or nonleading twist. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Univ Alberta, Dept Phys, Edmonton, AB T6G 2J1, Canada. Argonne Natl Lab, Div Phys, Argonne, IL 60439 USA. Ist Nazl Fis Nucl, Sez Bari, I-70124 Bari, Italy. CALTECH, WK Kellogg Radiat Lab, Pasadena, CA 91125 USA. Univ Colorado, Nucl Phys Lab, Boulder, CO 80309 USA. DESY, Deutsch Elektronen Synchrotron, D-22603 Hamburg, Germany. DESY Zeuthen, D-15738 Zeuthen, Germany. Joint Inst Nucl Res, Dubna 141980, Russia. Univ Erlangen Nurnberg, Inst Phys, D-91058 Erlangen, Germany. Univ Ferrara, Ist Nazl Fis Nucl, Sez Ferrara, I-44100 Ferrara, Italy. Univ Ferrara, Dipartimento Fis, I-44100 Ferrara, Italy. Ist Nazl Fis Nucl, Lab Nazl Frascati, I-00044 Frascati, Italy. Univ Freiburg, Fak Phys, D-79104 Freiburg, Germany. Univ Ghent, Dept Subat & Radiat Phys, B-9000 Ghent, Belgium. Max Planck Inst Kernphys, D-69029 Heidelberg, Germany. Univ Illinois, Dept Phys, Urbana, IL 61801 USA. Univ Liverpool, Dept Phys, Liverpool L69 7ZE, Merseyside, England. Univ Wisconsin, Dept Phys, Madison, WI 53706 USA. MIT, Nucl Sci Lab, Cambridge, MA 02139 USA. Univ Michigan, Randall Lab Phys, Ann Arbor, MI 48109 USA. PN Lebedev Phys Inst, Moscow 117924, Russia. Univ Munich, Sekt Phys, D-85748 Garching, Germany. New Mexico State Univ, Dept Phys, Las Cruces, NM 88003 USA. NIKHEF, NL-1009 DB Amsterdam, Netherlands. Petersburg Nucl Phys Inst, Gatchina 188350, Russia. Univ Regensburg, Inst Theoret Phys, D-93040 Regensburg, Germany. Ist Nazl Fis Nucl, Sez Sanita, I-00161 Rome, Italy. Ist Super Sanita, Phys Lab, I-00161 Rome, Italy. Simon Fraser Univ, Dept Phys, Burnaby, BC V5A 1S6, Canada. TRIUMF, Vancouver, BC V6T 2A3, Canada. Tokyo Inst Technol, Dept Phys, Tokyo 152, Japan. Free Univ Amsterdam, Dept Phys & Astron, NL-1081 HV Amsterdam, Netherlands. Yerevan Phys Inst, Yerevan 375036, Armenia. RP Univ Alberta, Dept Phys, Edmonton, AB T6G 2J1, Canada. EM vincter@hermes.desy.de RI Arrington, John/D-1116-2012; Gavrilov, Gennady/C-6260-2013; Holt, Roy/E-5803-2011; Kozlov, Valentin/M-8000-2015; Terkulov, Adel/M-8581-2015; Cisbani, Evaristo/C-9249-2011 OI Arrington, John/0000-0002-0702-1328; Cisbani, Evaristo/0000-0002-6774-8473 NR 40 TC 26 Z9 27 U1 1 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0370-2693 EI 1873-2445 J9 PHYS LETT B JI Phys. Lett. B PD NOV 23 PY 2000 VL 494 IS 1-2 BP 1 EP 8 DI 10.1016/S0370-2693(00)01111-4 PG 8 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 378EF UT WOS:000165571500001 ER PT J AU Yu, HG Nyman, G AF Yu, HG Nyman, G TI Interpolated ab initio quantum scattering for the reaction of OH with HCl SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID POTENTIAL-ENERGY SURFACES; APPROXIMATING FUNCTIONAL-APPROACH; ATOM TRIATOM REACTIONS; RATE CONSTANTS; REACTION DYNAMICS; 4-ATOM REACTIONS; CL+CH4-REVERSIBLE-ARROW-HCL+CH3 REACTION; REACTION OH+H-2->H2O+H; DIMENSIONAL QUANTUM; CROSS-SECTIONS AB We present an interpolated ab initio quantum scattering (AIQS) approach to studying chemical reactions. The dynamics calculations were performed by solving the time-independent Schrodinger equation. The potential energy surface used was interpolated from a set of grid energy points by a generalized discrete variable representation method. The guided spectral transform technique developed by the authors and the single-sector hyperspherical projection method for boundary conditions were extended to the rotating bond approximation model. The AIQS approach has been applied to the OH+HCl --> Cl+H2O reaction, where the grid energy points were calculated by a dual level ab initio theory. The results obtained show that there exist a van der Waals complex in the entrance channel and an early saddle point with nonplanar geometry. Calculated thermal rate constants are in good agreement with the experimental results. They are nearly temperature-independent at low temperatures (T < 300 K) while a sharp increase with temperature is observed at higher temperatures. In addition, it was found that the long range interaction potential plays an important role in the dynamics. (C) 2000 American Institute of Physics. [S0021-9606(00)01844-4]. C1 Gothenburg Univ, Dept Chem, S-41296 Gothenburg, Sweden. RP Yu, HG (reprint author), Brookhaven Natl Lab, Dept Chem, Upton, NY 11973 USA. RI Nyman, Gunnar/B-1705-2009; Yu, Hua-Gen/N-7339-2015 NR 89 TC 35 Z9 35 U1 1 U2 6 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD NOV 22 PY 2000 VL 113 IS 20 BP 8936 EP 8944 DI 10.1063/1.1319999 PG 9 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 372CQ UT WOS:000165217000009 ER PT J AU Barrios, R Skurski, P Rak, J Gutowski, M AF Barrios, R Skurski, P Rak, J Gutowski, M TI An ab initio study of (H3B <- NH3)(-) - a dipole-bound anion supported by the dative charge-transfer bond in the neutral host SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID STATES; ELECTRON; COMPLEXES; ENERGIES; BINDING; BH3NH3; BORON; NMR AB The possibility of electron binding to the complex (H3BNH3) was studied at the coupled cluster level of theory with single, double, and noniterative triple excitations. The staggered conformation (minimum), with a dipole moment of 5.3 Debye, binds an electron by 984 cm(-1), whereas the eclipsed conformer (saddle point) possesses a larger dipole moment (5.5 Debye) and binds an electron by 1014 cm(-1). The neutral parent of the (H3BNH3)(-) anion involves a dative bond that is responsible for a significant polarization of the neutral species and generates a significant dipole moment. (C) 2000 American Institute of Physics. [S0021-9606(00)30144-1]. C1 Univ Utah, Dept Chem, Henry Eyring Ctr Theoret Chem, Salt Lake City, UT 84112 USA. Univ Gdansk, Dept Chem, PL-80952 Gdansk, Poland. Pacific NW Natl Lab, Environm Mol Sci Lab, Richland, WA 99352 USA. RP Skurski, P (reprint author), Univ Utah, Dept Chem, Henry Eyring Ctr Theoret Chem, Salt Lake City, UT 84112 USA. EM piotr@hydrogen.hec.utah.edu NR 49 TC 12 Z9 12 U1 0 U2 0 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 EI 1089-7690 J9 J CHEM PHYS JI J. Chem. Phys. PD NOV 22 PY 2000 VL 113 IS 20 BP 8961 EP 8968 DI 10.1063/1.1319642 PG 8 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 372CQ UT WOS:000165217000012 ER PT J AU Hura, G Sorenson, JM Glaeser, RM Head-Gordon, T AF Hura, G Sorenson, JM Glaeser, RM Head-Gordon, T TI A high-quality x-ray scattering experiment on liquid water at ambient conditions SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID PAIR CORRELATION-FUNCTIONS; DIFFRACTION; PRESSURES; NEUTRON; MODEL AB We report a new, high-quality x-ray scattering experiment on pure ambient water using a synchrotron beam line at the Advanced Light Source at Lawrence Berkeley National Laboratory. Several factors contribute to the improved quality of our intensity curves including use of a highly monochromatic source, a well-characterized polarization correction, a Compton scattering correction that includes electron correlation, and more accurate intensities using a modern charge coupled device (CCD) detector. We provide a comprehensive description of the data processing that we have used for correcting systematic errors, and we provide an estimate of our remaining random errors. The resulting error estimates of our data are smaller then the discrepancies between data sets collected in past x-ray experiments. We find that the older x-ray curves support a family of g(OO)(r)'s that exhibit a smaller first peak (similar to2.2), while the current data is better fit with a family of g(OO)(r)'s with a first peak height of 2.8, and systematic shifts in all peak positions to smaller r. (C) 2000 American Institute of Physics. [S0021-9606(00)50744-2]. C1 Univ Calif Berkeley, Dept Mol & Cell Biol, Berkeley, CA 94720 USA. Univ Calif Berkeley, Grad Grp Biophys, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Life Sci, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Phys Biosci Div, Berkeley, CA 94720 USA. RP Glaeser, RM (reprint author), Univ Calif Berkeley, Dept Mol & Cell Biol, 229 Stanley Hall, Berkeley, CA 94720 USA. RI Head-Gordon, Teresa/E-5818-2011 NR 28 TC 221 Z9 227 U1 3 U2 29 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD NOV 22 PY 2000 VL 113 IS 20 BP 9140 EP 9148 AR PII [S0021-9606(00)50744-2] DI 10.1063/1.1319614 PG 9 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 372CQ UT WOS:000165217000031 ER PT J AU Sorenson, JM Hura, G Glaeser, RM Head-Gordon, T AF Sorenson, JM Hura, G Glaeser, RM Head-Gordon, T TI What can x-ray scattering tell us about the radial distribution functions of water? SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID MOLECULAR-DYNAMICS SIMULATIONS; ELECTRON POPULATION ANALYSIS; EFFECTIVE PAIR POTENTIALS; ACCURATE DIFFRACTION DATA; LIQUID WATER; FORCE-FIELDS; MODEL; CHARGE; APPROXIMATION; DIPOLE AB We present an analysis of the Advanced Light Source (ALS) x-ray scattering experiment on pure liquid water at ambient temperature and pressure described in the preceding article. The present study discusses the extraction of radial distribution functions from the x-ray scattering of molecular fluids. It is proposed that the atomic scattering factors used to model water be modified to include the changes in the intramolecular electron distribution caused by chemical bonding effects. Based on this analysis we present a g(OO)(r) for water consistent with our recent experimental data gathered at the ALS, which differs in some aspects from the g(OO)(r) reported by other x-ray and neutron scattering experiments. Our g(OO)(r) exhibits a taller and sharper first peak, and systematic shifts in all peak positions to smaller r. Based on experimental uncertainties, we discuss what features of g(OO)(r) should be reproduced by classical simulations of nonpolarizable and polarizable water models, as well as ab initio simulations of water, at ambient conditions. We directly compare many water models and simulations to the present data, and discuss possible improvements in both classical and ab initio simulation approaches in the future. (C) 2000 American Institute of Physics. [S0021-9606(00)50844-7]. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Div Phys Biosci, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Dept Chem, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Grad Grp Biophys, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Life Sci, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Dept Mol & Cell Biol, Berkeley, CA 94720 USA. RP Head-Gordon, T (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Div Phys Biosci, Berkeley, CA 94720 USA. RI Head-Gordon, Teresa/E-5818-2011 NR 76 TC 298 Z9 303 U1 1 U2 40 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD NOV 22 PY 2000 VL 113 IS 20 BP 9149 EP 9161 DI 10.1063/1.1319615 PG 13 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 372CQ UT WOS:000165217000032 ER PT J AU Wilson, C Iversen, BB Overgaard, J Larsen, FK Wu, G Palii, SP Timco, GA Gerbeleu, NV AF Wilson, C Iversen, BB Overgaard, J Larsen, FK Wu, G Palii, SP Timco, GA Gerbeleu, NV TI Multi-temperature crystallographic studies of mixed-valence polynuclear complexes; Valence trapping process in the trinuclear oxo-bridged iron compound, [Fe3O(O2CC(CH3)(3))(6)(C5H5N)(3)] SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Article ID INTRAMOLECULAR ELECTRON-TRANSFER; DETRAPPING PHASE-TRANSITION; JAHN-TELLER DISTORTIONS; X-RAY; HEAT-CAPACITY; SOLID-STATE; CRYSTAL-STRUCTURE; DISPLACEMENT PARAMETERS; CYANOACETATE COMPLEX; NEUTRON-DIFFRACTION AB Single-crystal X-ray diffraction data have been collected on five different crystals at 12 different temperatures (10, 28, 35, 60, 85, 100, 118, 135, 160, 200, 240, 295 K) on a trinuclear, ore-bridged, mixed-valence iron complex, Fe3O(O2CC(CH3)(3))(6)(C5H5N)(3), using both synchrotron and conventional radiation sources. The present study for the first time provides structural information for an ore-bridged trinuclear compound below the boiling point of nitrogen (77 K). The use of very low-temperature crystallographic data is crucial for understanding the physical properties of the complex. No change of space group is observed in the whole temperature range, although a reversible broadening of the Bragg peaks is observed around 85 K. The structure has ordering processes involving the tert-butyl groups, and above 85 K, four tert-butyl groups become disordered. Around 150 K, a fifth tert-butyl becomes disordered, whereas the last tert-butyl is ordered at all temperatures. Very significant temperature-dependent changes in the Fe-ligand bond lengths an observed which are interpreted as being due to dynamic disorder caused by intramolecular electron transfer (ET) between the metal sites. The ET process is significantly affected by changes in the molecular potential energy surface (PES) caused by the dynamic behavior of the tert-butyls. The dynamic disorder of the Fe3O core resulting from the ET process is examined through analysis of the atomic displacement parameters. The ET process involves only two of the three iron sites, with the third site appearing to be valence-trapped at all temperatures. The trapping of this iron site at all temperatures appears to be related to the asymmetry caused by the different dynamic behaviors of the tert-butyls. At very low temperatures (<10 K), the system becomes valence-trapped and consists of a single configuration without disorder. Boltzmann population models are used to estimate the energy difference between the two lowest-lying minima on the PES (E < 100 cm(-1)) and between two disordered configurations of each of the tert-butyls (E = 217, 212, 255, 359, and 345 cm(-1)). C1 Aarhus Univ, Dept Chem, DK-8000 Aarhus C, Denmark. Brookhaven Natl Lab, Upton, NY 11973 USA. Moldavian Acad Sci, Inst Chem, MD-2028 Kishinev, Moldova. RP Aarhus Univ, Dept Chem, Langelandsgade 140, DK-8000 Aarhus C, Denmark. EM bo@kemi.aau.dk RI Overgaard, Jacob/C-3519-2008; OI Wilson, Claire/0000-0002-0090-5374 NR 68 TC 61 Z9 63 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 NOV 22 PY 2000 VL 122 IS 46 BP 11370 EP 11379 DI 10.1021/ja994162a PG 10 WC Chemistry, Multidisciplinary SC Chemistry GA 378TL UT WOS:000165600300012 ER PT J AU Greathouse, JA Refson, K Sposito, G AF Greathouse, JA Refson, K Sposito, G TI Molecular dynamics simulation of water mobility in magnesium-smectite hydrates SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Article ID MONTE-CARLO SIMULATION; COMPUTER-SIMULATION; INTERLAYER WATER; CLAY HYDRATION; MONTMORILLONITE; SODIUM; POTENTIALS; POTASSIUM; MECHANISM; MINERALS AB Water diffusion and interlayer structure in Mg-smectite hydrates was investigated by molecular dynamics and Monte Carlo computer simulation. Smectites with only tetrahedral layer charge (Mg-beidellite) were examined at 300 and 400 K, each with two layers of adsorbed water. Previous quasielastic neutron-scattering experiments have indicated that nonsolvating water molecules in Mg-smectites exhibit faster diffusional motion within a "cage" formed by the solvated Mg(H2O)(6)(2+) counterions than they do via inter-cage motion. Our 500-1175 ps MD simulations suggested that the dimension of this "cage" region is approximately 5.5 Angstrom, but two-phase diffusional behavior was observed only for water in Mg-beidellite at 300 K. The counterions in Mg-beidellite formed outer-sphere surface complexes with the clay mineral siloxane surface, but nonsolvating water: molecules showed a significant tendency to occupy ditrigonal cavities in the surface. This behavior could be responsible for the small equilibrium layer spacing in Mg-beidellite, as well as a lower water self-diffusion coefficient. C1 St Lawrence Univ, Dept Chem, Canton, NY 13617 USA. Univ Oxford, Dept Earth Sci, Oxford OX1 3PR, England. Univ Calif Berkeley, Lawrence Berkeley Lab, Dept Geochem, Div Earth Sci, Berkeley, CA 94720 USA. RP Greathouse, JA (reprint author), St Lawrence Univ, Dept Chem, Canton, NY 13617 USA. RI Refson, Keith/G-1407-2013; OI Refson, Keith/0000-0002-8715-5835 NR 35 TC 79 Z9 81 U1 1 U2 23 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 NOV 22 PY 2000 VL 122 IS 46 BP 11459 EP 11464 DI 10.1021/ja0018769 PG 6 WC Chemistry, Multidisciplinary SC Chemistry GA 378TL UT WOS:000165600300022 ER PT J AU Coulter, ED Emerson, JP Kurtz, DM Cabelli, DE AF Coulter, ED Emerson, JP Kurtz, DM Cabelli, DE TI Superoxide reactivity of rubredoxin oxidoreductase (desulfoferrodoxin) from Desulfovibrio vulgaris: A pulse radiolysis study SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Article ID RBO GENE-PRODUCT; DESULFURICANS ATCC-27774; ESCHERICHIA-COLI; DISMUTASE; IRON; OVERPRODUCTION; PROTEIN; GIGAS C1 Univ Georgia, Dept Chem, Athens, GA 30602 USA. Univ Georgia, Ctr Metalloenzyme Studies, Athens, GA 30602 USA. Brookhaven Natl Lab, Dept Chem, Upton, NY 11973 USA. RP Kurtz, DM (reprint author), Univ Georgia, Dept Chem, Athens, GA 30602 USA. NR 19 TC 84 Z9 84 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 NOV 22 PY 2000 VL 122 IS 46 BP 11555 EP 11556 DI 10.1021/ja005583r PG 2 WC Chemistry, Multidisciplinary SC Chemistry GA 378TL UT WOS:000165600300052 ER PT J AU Han, ZW Tout, CA Eggleton, PP AF Han, ZW Tout, CA Eggleton, PP TI Low- and intermediate-mass close binary evolution and the initial-final mass relation SO MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY LA English DT Article DE binaries : close; stars : evolution; white dwarfs ID NEUTRINO ENERGY-LOSS; STELLAR EVOLUTION; WHITE-DWARFS; STARS; ABUNDANCES; SUPERNOVAE; OPACITIES; SEQUENCES; INTERIORS; GIANTS AB Using Eggleton's stellar evolution code, we carry out 150 runs of Population I binary evolution calculations with the initial primary mass between 1 and 8 M-circle dot, the initial mass ratio q = M-1/M-2 between 1.1 and 4, and the onset of Roche lobe overflow (RLOF) at an early, middle or late Hertzsprung-gap stage. We assume that PLOP is conservative in the calculations, and find that the remnant mass of the primary may change by more than 40 per cent over the range of initial mass ratio or orbital period, for a given primary mass. This is contrary to the often-held belief that the remnant mass depends only on the progenitor mass if mass transfer begins in the Hertzsprung gap. We fit a formula, with an error less than 3.6 per cent, for the remnant (white dwarf) mass as a function of the initial mass M-li of the primary, the initial mass ratio q(i) and the radius of the primary at the onset of RLOF We also find that a carbon-oxygen white dwarf with mass as low as 0.33 M-circle dot may be formed if the initial mass of the primary is around 2.5 M-circle dot. C1 Acad Sinica, Yunnan Observ, Kunming 650011, Peoples R China. Chinese Acad Sci, Natl Astron Observ, Beijing 100864, Peoples R China. Univ Cambridge, Inst Astron, Cambridge CB3 0HA, England. Univ Calif Lawrence Livermore Natl Lab, IGPP, Livermore, CA 94550 USA. RP Han, ZW (reprint author), Acad Sinica, Yunnan Observ, Kunming 650011, Peoples R China. RI Han, Zhanwen/A-9741-2009 NR 30 TC 88 Z9 92 U1 0 U2 1 PU BLACKWELL SCIENCE LTD PI OXFORD PA P O BOX 88, OSNEY MEAD, OXFORD OX2 0NE, OXON, ENGLAND SN 0035-8711 J9 MON NOT R ASTRON SOC JI Mon. Not. Roy. Astron. Soc. PD NOV 21 PY 2000 VL 319 IS 1 BP 215 EP 222 DI 10.1046/j.1365-8711.2000.03839.x PG 8 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 383VN UT WOS:000165905000017 ER PT J AU Esarey, E AF Esarey, E TI Laser cooling of electron beams via Thomson scattering SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT International Symposium on New Visions in Laser-Beam Interactions CY OCT 11-15, 1999 CL TOKYO, JAPAN SP Fdn High Energy Accelerator Sci, Atom Energy Soc Japan, Japan IBM, Hitachi Zosen Corp, AMSC Co Ltd, BM Ind, IDX Corp, Saitou Shouten, Sumitomo Heavy Ind Ltd, Kantou Informat Serv Co DE laser cooling; electron beams; Thomson scattering ID FEMTOSECOND X-RAYS; PULSES; GENERATION; PLASMAS AB The laser radiative cooling of electron beams via Thomson scattering is discussed, analyzed, and simulated. As a beam radiates via Thomson scattering, it is subsequently cooled, i.e., the mean energy, normalized energy spread, and normalized emittance are reduced in a similar manner. An analytical expression is derived for the damping distance, and this is found to agree well with electron beam transport simulations. Although laser cooling can occur rapidly ton ps time scales), it does not occur indefinitely, due to the effects of quantum excitation from discrete photon emission. Quantum excitation places serious limitations on the minimum energy spread and normalized emittance that can be obtained by laser cooling. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Ctr Beam Phys, Berkeley, CA 94720 USA. RP Esarey, E (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Ctr Beam Phys, Berkeley, CA 94720 USA. NR 16 TC 16 Z9 16 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 NOV 21 PY 2000 VL 455 IS 1 BP 7 EP 14 DI 10.1016/S0168-9002(00)00685-9 PG 8 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 377LE UT WOS:000165514400003 ER PT J AU Kashiwagi, S Washio, M Kobuki, T Kuroda, R Ben-Zvi, I Pogorelsky, I Kusche, K Skaritka, J Yakimenko, V Wang, XJ Hirose, T Dobashi, K Muto, T Urakawa, J Omori, T Okugi, T Tsunemi, A Liu, Y He, P Cline, D Segalov, Z AF Kashiwagi, S Washio, M Kobuki, T Kuroda, R Ben-Zvi, I Pogorelsky, I Kusche, K Skaritka, J Yakimenko, V Wang, XJ Hirose, T Dobashi, K Muto, T Urakawa, J Omori, T Okugi, T Tsunemi, A Liu, Y He, P Cline, D Segalov, Z TI Observation of high-intensity X-rays in inverse Compton scattering experiment SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT International Symposium on New Visions in Laser-Beam Interactions CY OCT 11-15, 1999 CL TOKYO, JAPAN SP Fdn High Energy Accelerator Sci, Atom Energy Soc Japan, Japan IBM, Hitachi Zosen Corp, AMSC Co Ltd, BM Ind, IDX Corp, Saitou Shouten, Sumitomo Heavy Ind Ltd, Kantou Informat Serv Co DE CO2 laser; Compton scattering; X-rays; electron beam AB We report the first results of high-intensity X-ray generation using Inverse Laser Compton scattering, This experiment was carried out by a US-Japan collaboration at the Brookhaven National Laboratory (BNL) Accelerator Test Facility (ATF) in September 1999. The 3.5 ps X-ray pulse at 6.5 keV, containing 3 x 10(6) X-ray photons was generated by the interaction of 60 MeV, 0.5 nC electron bunches and CO2 laser pulses of 600 MW peak power. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Waseda Univ, Adv Res Inst Sci & Engn, Shinjuku Ku, Tokyo 1698555, Japan. Brookhaven Natl Lab, Upton, NY 11973 USA. High Energy Accelerator Res Org, Tsukuba, Ibaraki 3050801, Japan. Tokyo Metropolitan Univ, Hachioji, Tokyo 1920397, Japan. Sumitomo Heavy Ind Ltd, Tanashi, Tokyo 1888585, Japan. Univ Calif Los Angeles, Los Angeles, CA 90024 USA. Rafael Corp, IL-31021 Haifa, Israel. RP Kashiwagi, S (reprint author), Waseda Univ, Adv Res Inst Sci & Engn, Shinjuku Ku, 3-4-1 Okubo, Tokyo 1698555, Japan. RI Kuroda, Ryunosuke/D-2722-2014 OI Kuroda, Ryunosuke/0000-0002-8970-3321 NR 3 TC 28 Z9 30 U1 1 U2 5 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 NOV 21 PY 2000 VL 455 IS 1 BP 36 EP 40 DI 10.1016/S0168-9002(00)00689-6 PG 5 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 377LE UT WOS:000165514400007 ER PT J AU Aoki, Y Yang, JF Hirose, M Sakai, F Tsunemi, A Yorozu, M Okada, Y Endo, A Wang, XJ Ben-Zvi, I AF Aoki, Y Yang, JF Hirose, M Sakai, F Tsunemi, A Yorozu, M Okada, Y Endo, A Wang, XJ Ben-Zvi, I TI A new chemical analysis system using a photocathode RF gun SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT International Symposium on New Visions in Laser-Beam Interactions CY OCT 11-15, 1999 CL TOKYO, JAPAN SP Fdn High Energy Accelerator Sci, Atom Energy Soc Japan, Japan IBM, Hitachi Zosen Corp, AMSC Co Ltd, BM Ind, IDX Corp, Saitou Shouten, Sumitomo Heavy Ind Ltd, Kantou Informat Serv Co DE photocathode; RF gun; pulse radiolysis; photo-absorption spectroscopy; OPG ID PULSE-RADIOLYSIS; PICOSECOND AB A compact chemical analysis (pulse radiolysis) apparatus using a BNL-type s-band photocathode RF gun (GUN-IV) is now under development at Sumitomo Heavy Industries (SHI). Using the apparatus, fast chemical reactions induced by 3.5 ps pulse of electron beam can be analyzed by means of time-resolved photo-absorption spectroscopy with 10 ps laser pulses in the wavelength range of 210-2000 nm. The high-precision control of RF phase makes 10 ps of time-resolution possible for the analysis, (C) 2000 Elsevier Science B.V. All rights reserved. C1 SHI, R&D Ctr, Tanashi, Tokyo 1888585, Japan. Brookhaven Natl Lab, ATF, Upton, NY 11973 USA. RP Aoki, Y (reprint author), SHI, R&D Ctr, Tanashi, Tokyo 1888585, Japan. RI Endo, Akira/G-6268-2014 NR 27 TC 23 Z9 23 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 NOV 21 PY 2000 VL 455 IS 1 BP 99 EP 103 DI 10.1016/S0168-9002(00)00713-0 PG 5 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 377LE UT WOS:000165514400017 ER PT J AU Cowan, TE Roth, M Johnson, J Brown, C Christl, M Fountain, W Hatchett, S Henry, EA Hunt, AW Key, MH MacKinnon, A Parnell, T Pennington, DM Perry, MD Phillips, TW Sangster, TC Singh, M Snavely, R Stoyer, M Takahashi, Y Wilks, SC Yasuike, K AF Cowan, TE Roth, M Johnson, J Brown, C Christl, M Fountain, W Hatchett, S Henry, EA Hunt, AW Key, MH MacKinnon, A Parnell, T Pennington, DM Perry, MD Phillips, TW Sangster, TC Singh, M Snavely, R Stoyer, M Takahashi, Y Wilks, SC Yasuike, K TI Intense electron and proton beams from PetaWatt laser-matter interactions SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT International Symposium on New Visions in Laser-Beam Interactions CY OCT 11-15, 1999 CL TOKYO, JAPAN SP Fdn High Energy Accelerator Sci, Atom Energy Soc Japan, Japan IBM, Hitachi Zosen Corp, AMSC Co Ltd, BM Ind, IDX Corp, Saitou Shouten, Sumitomo Heavy Ind Ltd, Kantou Informat Serv Co ID HOT-ELECTRONS; PLASMA; PULSES AB Recent experiments at the LLNL Petawatt Laser have demonstrated the generation of intense, high-energy beams of electrons and ions from the interaction of ultra-intense laser light with solid targets. The focused laser intensities are as high as 6 x 10(20) W/cm(2), at which point the quiver energies of the target electrons extend to similar to 10 MeV. In this new, fully relativistic regime of laser-plasma interactions, nuclear processes become important and nuclear techniques are required to diagnose the high-energy particle production. We describe recent experiments in which we have observed electrons accelerated to 100 MeV, photo-nuclear fission, positron-electron pair creation, monoenergetic electron jets and intense beams of protons emitted from the back surface of a laser-irradiated target. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Univ Calif Lawrence Livermore Natl Lab, Dept Phys, Livermore, CA 94550 USA. Gesell Schwerionenforsch, Darmstadt, Germany. George C Marshall Space Flight Ctr, Huntsville, AL 35899 USA. Harvard Univ, Cambridge, MA 02138 USA. Univ Alabama, Huntsville, AL 35899 USA. Osaka Univ, Inst Laser Engn, Osaka, Japan. RP Cowan, TE (reprint author), Univ Calif Lawrence Livermore Natl Lab, Dept Phys, L-280,POB 808, Livermore, CA 94550 USA. RI MacKinnon, Andrew/P-7239-2014; Cowan, Thomas/A-8713-2011 OI MacKinnon, Andrew/0000-0002-4380-2906; Cowan, Thomas/0000-0002-5845-000X NR 18 TC 47 Z9 47 U1 0 U2 5 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 NOV 21 PY 2000 VL 455 IS 1 BP 130 EP 139 DI 10.1016/S0168-9002(00)00720-8 PG 10 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 377LE UT WOS:000165514400024 ER PT J AU Katsouleas, T Mori, WB Dodd, E Lee, S Hemker, R Clayton, C Joshi, C Esarey, E AF Katsouleas, T Mori, WB Dodd, E Lee, S Hemker, R Clayton, C Joshi, C Esarey, E TI Laser steering of particle beams: refraction and reflection of particle beams SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT International Symposium on New Visions in Laser-Beam Interactions CY OCT 11-15, 1999 CL TOKYO, JAPAN SP Fdn High Energy Accelerator Sci, Atom Energy Soc Japan, Japan IBM, Hitachi Zosen Corp, AMSC Co Ltd, BM Ind, IDX Corp, Saitou Shouten, Sumitomo Heavy Ind Ltd, Kantou Informat Serv Co ID CHANNEL AB The co-propagation of an intense particle beam with an ionizing laser beam in a working gas/plasma is considered. When the axes of the laser and particle beam are not aligned, then asymmetric plasma lensing results in a net dipole field acting on the particle beam. The particle beam can be steered or bent (as well as focused) by steering the laser. An analogy is made between the bending of the particle beam by collective effects at a plasma boundary and the refraction or reflection of light at an interface. This mechanism of particle steering may be of interest in applications for which permanent magnets are inconvenient or a fast turn on is required. 3-D particle-in-cell simulations and relevance to a recent experiment are discussed. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Univ So Calif, Los Angeles, CA 90089 USA. Univ Calif Los Angeles, Los Angeles, CA 90095 USA. Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. RP Katsouleas, T (reprint author), Univ So Calif, Los Angeles, CA 90089 USA. NR 8 TC 1 Z9 1 U1 0 U2 3 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 NOV 21 PY 2000 VL 455 IS 1 BP 161 EP 165 DI 10.1016/S0168-9002(00)00724-5 PG 5 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 377LE UT WOS:000165514400028 ER PT J AU Pogorelsky, IV Ben-Zvi, I Wang, XJ Hirose, T AF Pogorelsky, IV Ben-Zvi, I Wang, XJ Hirose, T TI Femtosecond laser synchrotron sources based on Compton scattering in plasma channels SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT International Symposium on New Visions in Laser-Beam Interactions CY OCT 11-15, 1999 CL TOKYO, JAPAN SP Fdn High Energy Accelerator Sci, Atom Energy Soc Japan, Japan IBM, Hitachi Zosen Corp, AMSC Co Ltd, BM Ind, IDX Corp, Saitou Shouten, Sumitomo Heavy Ind Ltd, Kantou Informat Serv Co DE CO2 laser; Compton scattering; X-rays ID PULSES AB We propose a laser synchrotron source (LSS) based on Compton backscattering of electron and laser beams in an extended plasma channel. This approach opens new prospects towards high-power monochromatic X-ray and gamma sources by utilizing an existing technology of the high-power high-repetition rate gas lasers. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Brookhaven Natl Lab, Accelerator Test Facil, Upton, NY 11973 USA. Tokyo Metropolitan Univ, Dept Phys, Tokyo, Japan. RP Pogorelsky, IV (reprint author), Brookhaven Natl Lab, Accelerator Test Facil, 725C, Upton, NY 11973 USA. NR 14 TC 16 Z9 18 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD NOV 21 PY 2000 VL 455 IS 1 BP 176 EP 180 DI 10.1016/S0168-9002(00)00727-0 PG 5 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 377LE UT WOS:000165514400031 ER PT J AU Kabel, A Dohlus, M Limberg, T AF Kabel, A Dohlus, M Limberg, T TI Using TraFiC(4) to calculate and minimize emittance growth due to coherent synchrotron radiation SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT International Symposium on New Visions in Laser-Beam Interactions CY OCT 11-15, 1999 CL TOKYO, JAPAN SP Fdn High Energy Accelerator Sci, Atom Energy Soc Japan, Japan IBM, Hitachi Zosen Corp, AMSC Co Ltd, BM Ind, IDX Corp, Saitou Shouten, Sumitomo Heavy Ind Ltd, Kantou Informat Serv Co DE coherent synchrotron radiation; numerical simulation; emittance dilution AB Coherent synchrotron radiation occurs when short bunches travel on strongly bent trajectories. Its effects on high-quality beams can be severe and are well understood qualitatively. For quantitative results, however, one has to rely on numerical methods. The recent interest in high quality, high-current electron beams has generated considerable efforts to understand and minimize the effects of CSR on beam quality. By now several simulation codes, utilizing different approaches and making different approximations, exist. We describe in some detail the coder TraFiC(4) developed at DESY for design and analysis purposes. It calculates the fields acting on the pariticles from first principles and tracks particles through them in the laboratory frame. We present calculational results for three applications and give some comparison with experimental data. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Stanford Linear Accelerator Ctr, Menlo Park, CA 94025 USA. Deutsch Elektronen Synchrotron, D-22603 Hamburg, Germany. RP Kabel, A (reprint author), Stanford Linear Accelerator Ctr, 2575 Sand Hill Rd, Menlo Park, CA 94025 USA. NR 17 TC 13 Z9 13 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 NOV 21 PY 2000 VL 455 IS 1 BP 185 EP 189 DI 10.1016/S0168-9002(00)00729-4 PG 5 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 377LE UT WOS:000165514400033 ER PT J AU Clendenin, JE Kotseroglou, T Mulhollan, GA Palmer, DT Schmerge, JF AF Clendenin, JE Kotseroglou, T Mulhollan, GA Palmer, DT Schmerge, JF TI Reduction of thermal emittance of RF guns SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT International Symposium on New Visions in Laser-Beam Interactions CY OCT 11-15, 1999 CL TOKYO, JAPAN SP Fdn High Energy Accelerator Sci, Atom Energy Soc Japan, Japan IBM, Hitachi Zosen Corp, AMSC Co Ltd, BM Ind, IDX Corp, Saitou Shouten, Sumitomo Heavy Ind Ltd, Kantou Informat Serv Co DE photoemission; thermal emittance; RF guns; semiconductors AB The transverse emittance from optimized RF photoinjectors is limited by the thermal emittance. The thermal emittance can be lowered by a factor > 2 by using a semiconductor photocathode. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. RP Clendenin, JE (reprint author), Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. NR 7 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 NOV 21 PY 2000 VL 455 IS 1 BP 198 EP 201 DI 10.1016/S0168-9002(00)00731-2 PG 4 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 377LE UT WOS:000165514400035 ER PT J AU Okugi, T Hayano, H Kubo, K Naito, T Terunuma, N Urakawa, J Hirose, T Zimmermann, F Raubenheimer, TO AF Okugi, T Hayano, H Kubo, K Naito, T Terunuma, N Urakawa, J Hirose, T Zimmermann, F Raubenheimer, TO TI Evaluation of vertical emittance in KEK-ATF by utilizing lifetime measurement SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT International Symposium on New Visions in Laser-Beam Interactions CY OCT 11-15, 1999 CL TOKYO, JAPAN SP Fdn High Energy Accelerator Sci, Atom Energy Soc Japan, Japan IBM, Hitachi Zosen Corp, AMSC Co Ltd, BM Ind, IDX Corp, Saitou Shouten, Sumitomo Heavy Ind Ltd, Kantou Informat Serv Co AB It is difficult to measure the vertical emittance of the extremely low emittance rings such as third generation synchrotron light sources or damping rings of the future linear colliders due to their small vertical beam size. In such a low emittance ring, the beam lifetime is limited by the Touschek effect and ideally proportional to the bunch volume. Thus the bunch volume, or equivalently the vertical emittance when horizontal and longitudinal beam sizes are known, can be evaluated from the measurement of the Touschek lifetime. We determine the vertical emittance of the beam in KEK Accelerator Test Facility (KEK-ATF) damping ring by the lifetime model. The evaluated vertical emittance was 0.04 +/- 0.01 nm and it was consistent with the vertical emittance measured by wire-scanner beam profile monitors. (C) 2000 Elsevier Science B.V. All rights reserved. C1 High Energy Accelerator Res Org, Tsukuba, Ibaraki 3050801, Japan. Tokyo Metropolitan Univ, Fac Sci, Tokyo 1920364, Japan. CERN, European Lab Particle Phys, CH-1211 Geneva, Switzerland. Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. RP Okugi, T (reprint author), High Energy Accelerator Res Org, 1-1 Oho, Tsukuba, Ibaraki 3050801, Japan. NR 5 TC 2 Z9 2 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD NOV 21 PY 2000 VL 455 IS 1 BP 207 EP 212 DI 10.1016/S0168-9002(00)00733-6 PG 6 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 377LE UT WOS:000165514400037 ER PT J AU Kuroda, R Washio, M Kashiwagi, S Kobuki, T Ben-Zvi, I Wang, XJ Hori, T Sakai, F Tsunemi, A Urakawa, J Hirose, ST AF Kuroda, R Washio, M Kashiwagi, S Kobuki, T Ben-Zvi, I Wang, XJ Hori, T Sakai, F Tsunemi, A Urakawa, J Hirose, ST TI High-quality beam generation using an RF gun and a 150 MeV microtron SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT International Symposium on New Visions in Laser-Beam Interactions CY OCT 11-15, 1999 CL TOKYO, JAPAN SP Fdn High Energy Accelerator Sci, Atom Energy Soc Japan, Japan IBM, Hitachi Zosen Corp, AMSC Co Ltd, BM Ind, IDX Corp, Saitou Shouten, Sumitomo Heavy Ind Ltd, Kantou Informat Serv Co DE electron beam; laser photo-cathode RF gun; racetrack microtron AB Low-emittance sub-picosecond electron pulses are expected to be used in a wide field, such as free electron laser, laser acceleration, femtosecond X-ray generation by Inverse Compton scattering, pulse radiolysis, etc. In order to produce the low-emittance sub-picosecond electron pulse, we are developing a compact Racetrack Microtron (RTM) with a new 5 MeV injection system adopting a laser photo cathode RF gun (Washio et al., Seventh China-Japan Bilateral Symposium on Radiation Chemistry, October 28, Cengdu, China, 1996). The operation of RTM has been kept under a steady state of beam loading for long pulse mode so far (Washio et al., J. Surf Sci. Sec. Jpn. 19 (2) (1998) 23). In earlier work (Washio et al., PAC99, March 31, New York, USA, 1999), we have succeeded in the numerical simulation for the case of single short pulse acceleration. Finally, the modified RTM was demonstrated as a useful accelerator for a picosecond electron pulse generation under a transient state of beam loading. In the simulation, a picosecond electron pulse was accelerated to 149.6 MeV in RTM for the injection of 5 MeV electron bunch with a pulse length of 10 ps (FWHM), a charge of 1 nC per pulse, and an emittance of 3 pi mm mrad. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Waseda Univ, Shinjuku Ku, Tokyo, Japan. Brookhaven Natl Lab, Upton, NY 11973 USA. Tokyo Metropolitan Univ, Tokyo 158, Japan. RP Kuroda, R (reprint author), Waseda Univ, Shinjuku Ku, Okubo 3-4-1, Tokyo, Japan. RI Kuroda, Ryunosuke/D-2722-2014 OI Kuroda, Ryunosuke/0000-0002-8970-3321 NR 7 TC 2 Z9 2 U1 0 U2 3 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 NOV 21 PY 2000 VL 455 IS 1 BP 222 EP 227 DI 10.1016/S0168-9002(00)00736-1 PG 6 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 377LE UT WOS:000165514400040 ER PT J AU Goodrich, DC Chehbouni, A Goff, B MacNish, B Maddock, T Moran, S Shuttleworth, WJ Williams, DG Watts, C Hipps, LH Cooper, DI Schieldge, J Kerr, YH Arias, H Kirkland, M Carlos, R Cayrol, P Kepner, W Jones, B Avissar, R Begue, A Bonnefond, JM Boulet, G Branan, B Brunel, JP Chen, LC Clarke, T Davis, MR DeBruin, H Dedieu, G Elguero, E Eichinger, WE Everitt, J Garatuza-Payan, J Gempko, VL Gupta, H Harlow, C Hartogensis, O Helfert, M Holifield, C Hymer, D Kahle, A Keefer, T Krishnamoorthy, S Lhomme, JP Lagouarde, JP Lo Seen, D Luquet, D Marsett, R Monteny, B Ni, W Nouvellon, Y Pinker, R Peters, C Pool, D Qi, J Rambal, S Rodriguez, J Santiago, F Sano, E Schaeffer, SM Schulte, M Scott, R Shao, X Snyder, KA Sorooshian, S Unkrich, CL Whitaker, M Yucel, I AF Goodrich, DC Chehbouni, A Goff, B MacNish, B Maddock, T Moran, S Shuttleworth, WJ Williams, DG Watts, C Hipps, LH Cooper, DI Schieldge, J Kerr, YH Arias, H Kirkland, M Carlos, R Cayrol, P Kepner, W Jones, B Avissar, R Begue, A Bonnefond, JM Boulet, G Branan, B Brunel, JP Chen, LC Clarke, T Davis, MR DeBruin, H Dedieu, G Elguero, E Eichinger, WE Everitt, J Garatuza-Payan, J Gempko, VL Gupta, H Harlow, C Hartogensis, O Helfert, M Holifield, C Hymer, D Kahle, A Keefer, T Krishnamoorthy, S Lhomme, JP Lagouarde, JP Lo Seen, D Luquet, D Marsett, R Monteny, B Ni, W Nouvellon, Y Pinker, R Peters, C Pool, D Qi, J Rambal, S Rodriguez, J Santiago, F Sano, E Schaeffer, SM Schulte, M Scott, R Shao, X Snyder, KA Sorooshian, S Unkrich, CL Whitaker, M Yucel, I TI Preface paper to the Semi-Arid Land-Surface-Atmosphere (SALSA) Program special issue SO AGRICULTURAL AND FOREST METEOROLOGY LA English DT Article DE interdisciplinary; semi-arid; land-surface-atmosphere; SALSA; water balance; energy balance; ecological diversity AB The Semi-Arid Land-Surface-Atmosphere Program (SALSA) is a multi-agency, multi-national research effort that seeks to evaluate the consequences of natural and human-induced environmental change in semi-arid regions. The ultimate goal of SALSA is to advance scientific understanding of the semi-arid portion of the hydrosphere-biosphere interface in order to provide reliable information for environmental decision making. SALSA approaches this goal through a program of long-term, integrated observations, process research, modeling, assessment, and information management that is sustained by cooperation among scientists and information users. In this preface to the SALSA special issue, general program background information and the critical nature of semi-arid regions is presented. A brief description of the Upper San Pedro River Basin, the initial location for focused SALSA research follows. Several overarching research objectives under which much of the interdisciplinary research contained in the special issue was undertaken are discussed. Principal methods, primary research sites and data collection used by numerous investigators during 1997-1999 are then presented. Scientists from about 20 US, five European (four French and one Dutch), and three Mexican agencies and institutions have collaborated closely to make the research leading to this special issue a reality. The SALSA Program has served as a model of interagency cooperation by breaking new ground in the approach to large scale interdisciplinary science with relatively limited resources. Published by Elsevier Science B.V. C1 USDA ARS, SW Watershed Res Ctr, Tucson, AZ 85719 USA. IRD, IMADES, Hermosillo, Sonora, Mexico. Univ Arizona, Tucson, AZ USA. USDA ARS, Water Conservat Lab, Phoenix, AZ USA. Utah State Univ, Logan, UT 84322 USA. Univ Calif Los Alamos Natl Lab, Los Alamos, NM USA. CESBIO, Toulouse, France. CIRAD, Montpellier, France. Univ Iowa, Iowa City, IA USA. AUW, Wageningen, Netherlands. CNRS, CEFE, Montpellier, France. USDA ARS, Weslaco, TX 78596 USA. CALTECH, Jet Prop Lab, Pasadena, CA USA. INRA, Bordeaux, France. USGS, WRD, Tucson, AZ USA. US EPA, Las Vegas, NV 89193 USA. Audubon Res Ranch, Elgin, AZ USA. Rutgers State Univ, New Brunswick, NJ 08903 USA. Univ Maryland, College Pk, MD 20742 USA. RP Goodrich, DC (reprint author), USDA ARS, SW Watershed Res Ctr, Tucson, AZ 85719 USA. RI Lo Seen, Danny/C-2679-2008; Pinker, Rachel/F-6565-2010; begue, agnes/A-5718-2011; Gupta, Hoshin/D-1642-2010; sorooshian, soroosh/B-3753-2008; Schaeffer, Sean/G-5071-2012; Elguero, Eric/J-3014-2012; Goodrich, David/B-1763-2009; Williams, David/A-6407-2014; Lhomme, Jean Paul /G-7236-2015; Boulet, Gilles/C-3067-2013; Nouvellon, Yann/C-9295-2016; OI Lo Seen, Danny/0000-0002-7773-2109; begue, agnes/0000-0002-9289-1052; Gupta, Hoshin/0000-0001-9855-2839; sorooshian, soroosh/0000-0001-7774-5113; Goodrich, David/0000-0001-7735-1448; Williams, David/0000-0003-3627-5260; Boulet, Gilles/0000-0002-3905-7560; Hipps, Lawrence/0000-0002-7658-8571; Nouvellon, Yann/0000-0003-1920-3847; rambal, serge/0000-0001-5869-8382; Schaeffer, Sean/0000-0002-9684-2952 NR 56 TC 44 Z9 45 U1 0 U2 10 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-1923 J9 AGR FOREST METEOROL JI Agric. For. Meteorol. PD NOV 20 PY 2000 VL 105 IS 1-3 BP 3 EP 20 DI 10.1016/S0168-1923(00)00178-7 PG 18 WC Agronomy; Forestry; Meteorology & Atmospheric Sciences SC Agriculture; Forestry; Meteorology & Atmospheric Sciences GA 377JQ UT WOS:000165510800002 ER PT J AU Eichinger, W Cooper, D Kao, J Chen, LC Hipps, L Prueger, J AF Eichinger, W Cooper, D Kao, J Chen, LC Hipps, L Prueger, J TI Estimation of spatially distributed latent heat flux over complex terrain from a Raman lidar SO AGRICULTURAL AND FOREST METEOROLOGY LA English DT Article DE Raman lidar; topography; sap flux methods; evaporation; complex terrain ID ATMOSPHERIC WATER-VAPOR; BOUNDARY-LAYER; FOOTPRINT; SYSTEM AB A method is presented in which estimates of evaporation may be made over an area approaching three quarters of a square kilometer, with relatively fine (25 m) spatial resolution, using three-dimensional measurements of water vapor concentration from a scanning Raman lidar. The method is based upon Monin-Obukhov similarity theory applied to spatially and temporally averaged data, Data from the lidar is used to sense the location and orientation of the surface and the location of the water vapor measurements with respect to that surface. Maps of the spatial distribution of evaporation have been produced showing the evaporation rates at regular intervals throughout the day. The method was applied to the SALSA experimental site during the 1997 summer field campaign. The estimates of evaporation rates made during the campaign compare favorably with estimates made using sap flux methods with RMS differences of 18W/m(2). While the method has certain limitations, the three-dimensional character of the data allows for the detection of anomalous situations so that analysts may alter the analysis technique or reject the estimates from the affected regions. This information can be used in a wide variety of ways to study the spatial variations in evaporation caused by changes in soil type and moisture content, canopy type and topography. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Univ Iowa, Iowa Inst Hydraul Res, Iowa City, IA 52242 USA. Univ Calif Los Alamos Natl Lab, Los Alamos, NM USA. Utah State Univ, Logan, UT 84322 USA. USDA ARS, Natl Soil Tilth Lab, Ames, IA 50011 USA. RP Eichinger, W (reprint author), Univ Iowa, Iowa Inst Hydraul Res, 300 Riverside Dr, Iowa City, IA 52242 USA. OI Hipps, Lawrence/0000-0002-7658-8571 NR 23 TC 16 Z9 16 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-1923 J9 AGR FOREST METEOROL JI Agric. For. Meteorol. PD NOV 20 PY 2000 VL 105 IS 1-3 BP 145 EP 159 DI 10.1016/S0168-1923(00)00183-0 PG 15 WC Agronomy; Forestry; Meteorology & Atmospheric Sciences SC Agriculture; Forestry; Meteorology & Atmospheric Sciences GA 377JQ UT WOS:000165510800011 ER PT J AU Cooper, DI Eichinger, WE Kao, J Hipps, L Reisner, J Smith, S Schaeffer, SM Williams, DG AF Cooper, DI Eichinger, WE Kao, J Hipps, L Reisner, J Smith, S Schaeffer, SM Williams, DG TI Spatial and temporal properties of water vapor and latent energy flux over a riparian canopy SO AGRICULTURAL AND FOREST METEOROLOGY LA English DT Article DE Raman lidar; geostatistical techniques; Monin-Obukhov gradient technique ID ATMOSPHERIC BOUNDARY-LAYER; PINUS-PINASTER AIT; SAP FLOW; VARIABILITY; FOREST; LIDAR; HEAT; EVAPOTRANSPIRATION; EVAPORATION; FOOTPRINTS AB A scanning, volume-imaging Raman lidar was used in August 1997 to map the water vapor and latent energy flux fields in southern Arizona in support of the (Semi-Arid Land Surface Atmosphere) SALSA program. The SALSA experiment was designed to estimate evapotranspiration over a cottonwood riparian corridor and the adjacent mesquite-grass community. The lidar derived water vapor images showed microscale convective structures with a resolution of 1.5 m, and mapped fluxes with 75 m spatial resolution. Comparisons of water vapor means over cottonwoods and adjacent grasses show similar values over both surfaces, but the spatial Variability over the cottonwoods was substantially higher than over the grasses. Lidar images support the idea that the enhanced variability over the cottonwoods is reflected in the presence of spatially coherent microscale structures. Interestingly, these microscale structures appear to weaken during midday, suggesting possible evidence for stomatal closure. Spatially resolved latent energy fluxes were estimated from the lidar using Monin-Obukhov gradient technique. The technique was validated from sap-flow flux estimates of transpiration, and statistical analysis indicates very good agreement (within +/-15%) with coincident lidar flux estimates. Lidar derived latent energy maps showed that the riparian zone tended to have the highest fluxes over the site. In addition, the spatial variability of 30 min average fluxes were almost as large as the mean values. Geostatistical techniques where used to compute the spatial lag lengths, they were found to be between 100 and 200 m. Determination of such spatially continuous evapotranspiration from such a complex site presents watershed managers with an additional tool to quantify the water budgets of riparian plant communities with spatial resolution and flux accuracy that is compatible with existing hydrologic management tools. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Univ Iowa, Iowa City, IA USA. Utah State Univ, Logan, UT 84322 USA. Univ Arkansas, Fayetteville, AR 72701 USA. Univ Arizona, Tucson, AZ USA. RP Cooper, DI (reprint author), Univ Calif Los Alamos Natl Lab, MS J577, Los Alamos, NM 87545 USA. RI Schaeffer, Sean/G-5071-2012; Williams, David/A-6407-2014; OI Williams, David/0000-0003-3627-5260; Schaeffer, Sean/0000-0002-9684-2952; Hipps, Lawrence/0000-0002-7658-8571 NR 38 TC 27 Z9 33 U1 1 U2 13 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-1923 J9 AGR FOREST METEOROL JI Agric. For. Meteorol. PD NOV 20 PY 2000 VL 105 IS 1-3 BP 161 EP 183 DI 10.1016/S0168-1923(00)00180-5 PG 23 WC Agronomy; Forestry; Meteorology & Atmospheric Sciences SC Agriculture; Forestry; Meteorology & Atmospheric Sciences GA 377JQ UT WOS:000165510800012 ER PT J AU Kao, CYJ Hang, YH Cooper, DI Eichinger, WE Smith, WS Reisner, JM AF Kao, CYJ Hang, YH Cooper, DI Eichinger, WE Smith, WS Reisner, JM TI High-resolution modeling of LIDAR data mechanisms governing surface water vapor variability during SALSA SO AGRICULTURAL AND FOREST METEOROLOGY LA English DT Article DE water vapor LIDAR data; canopy effects; hydrodynamic model; small-scale eddies; water vapor variability ID ATMOSPHERIC BOUNDARY-LAYER; RAMAN-LIDAR AB An integrated tool that consists of a volume scanning high-resolution Raman water vapor LIDAR and a turbulence-resolving hydrodynamic model, called HIGRAD, is used to support the semi-arid land-surface-atmosphere (SALSA) program. The water vapor measurements collected during SALSA have been simulated by the HIGRAD code with a resolution comparable with that of the LIDAR data. The LIDAR provides the required "ground truth" of coherent water vapor eddies and the model allows for interpretation of the underlying physics of such measurements and characterizes the relationships between surface conditions, boundary layer dynamics, and measured quantities. The model results compare well with the measurements, including the overall structure and evolution of water vapor plumes, the contrast of plume variabilities over the cottonwoods and the grass land, and the mid-day suppression of turbulent activities over the canopy. The current study demonstrates an example that such an integration between modeling and LIDAR measurements can advance our understanding of the structure of fine-scale turbulent motions that govern evaporative exchange above a heterogeneous surface. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Kao, CYJ (reprint author), Univ Calif Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. NR 18 TC 9 Z9 9 U1 1 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-1923 J9 AGR FOREST METEOROL JI Agric. For. Meteorol. PD NOV 20 PY 2000 VL 105 IS 1-3 BP 185 EP 194 DI 10.1016/S0168-1923(00)00182-9 PG 10 WC Agronomy; Forestry; Meteorology & Atmospheric Sciences SC Agriculture; Forestry; Meteorology & Atmospheric Sciences GA 377JQ UT WOS:000165510800013 ER PT J AU Goodrich, DC Scott, R Qi, J Goff, B Unkrich, CL Moran, MS Williams, D Schaeffer, S Snyder, K MacNish, R Maddock, T Pool, D Chehbouni, A Cooper, DI Eichinger, WE Shuttleworth, WJ Kerr, Y Marsett, R Ni, W AF Goodrich, DC Scott, R Qi, J Goff, B Unkrich, CL Moran, MS Williams, D Schaeffer, S Snyder, K MacNish, R Maddock, T Pool, D Chehbouni, A Cooper, DI Eichinger, WE Shuttleworth, WJ Kerr, Y Marsett, R Ni, W TI Seasonal estimates of riparian evapotranspiration using remote and in situ measurements SO AGRICULTURAL AND FOREST METEOROLOGY LA English DT Article DE riparian evapotranspiration; Penman-Monteith model; cottonwood/willow transpiration; SALSA program; interdisciplinary; water balance ID TROPICAL FOREST; CANOPY AB In many semi-arid basins during extended periods when surface snowmelt or storm runoff is absent, groundwater constitutes the primary water source for human habitation, agriculture and riparian ecosystems. Utilizing regional groundwater models in the management of these water resources requires accurate estimates of basin boundary conditions. A critical groundwater boundary condition that is closely coupled to atmospheric processes and is typically known with little certainty is seasonal riparian evapotranspiration (ET), This quantity can often be a significant factor in the basin water balance in semi-arid regions yet is very difficult to estimate over a large area. Better understanding and quantification of seasonal, large-area riparian ET is a primary objective of the Semi-Arid Land-Surface-Atmosphere (SALSA) Program. To address this objective, a series of interdisciplinary experimental campaigns were conducted in 1997 in the San Pedro Basin in southeastern Arizona. The riparian system in this basin is primarily made up of three vegetation communities: mesquite (Prosopis velutina), sacaton grasses (Sporobolus wrightii), and a cottonwood (Populus fremontii)/willow (Salix goodingii) forest gallery. Micrometeorological measurement techniques were used to estimate ET from the mesquite and grasses. These techniques could not be utilized to estimate fluxes from the cottonwood/willow (C/W) forest gallery due to the height (20-30 m) and non-uniform linear nature of the forest gallery. Short-term (2-4 days) sap flux measurements were made to estimate canopy transpiration over several periods of the riparian growing season. Simultaneous remote sensing measurements were used to spatially extrapolate tree and stand measurements. Scaled C/W stand level sap flux estimates were utilized to calibrate a Penman-Monteith model to enable temporal extrapolation between synoptic measurement periods. With this model and set of measurements, seasonal riparian vegetation water use estimates for the riparian corridor were obtained. To validate these models, a 90-day pre-monsoon water balance over a 10 km section of the river was carried out. All components of the water balance, including riparian ET, were independently estimated. The closure of the water balance was roughly 5% of total inflows. The ET models were then used to provide riparian ET estimates over the entire corridor for the growing season. These estimates were approximately 14% less than those obtained from the most recent,groundwater model of the basin for a comparable river reach. Published by Elsevier Science B.V. C1 USDA ARS, SW Watershed Res Ctr, Tucson, AZ 85719 USA. Univ Arizona, Tucson, AZ USA. Michigan State Univ, E Lansing, MI 48824 USA. Univ Arkansas, Fayetteville, AR 72701 USA. US Geol Survey, Div Water Resources, Tucson, AZ USA. IRD, IMADES, Hermosillo, Sonora, Mexico. Univ Calif Los Alamos Natl Lab, Los Alamos, NM USA. Univ Iowa, Iowa City, IA USA. CESBIO, Toulouse, France. RP Goodrich, DC (reprint author), USDA ARS, SW Watershed Res Ctr, Tucson, AZ 85719 USA. RI Schaeffer, Sean/G-5071-2012; Goodrich, David/B-1763-2009; Williams, David/A-6407-2014; OI Goodrich, David/0000-0001-7735-1448; Williams, David/0000-0003-3627-5260; Schaeffer, Sean/0000-0002-9684-2952 NR 55 TC 79 Z9 82 U1 4 U2 26 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-1923 J9 AGR FOREST METEOROL JI Agric. For. Meteorol. PD NOV 20 PY 2000 VL 105 IS 1-3 BP 281 EP 309 DI 10.1016/S0168-1923(00)00197-0 PG 29 WC Agronomy; Forestry; Meteorology & Atmospheric Sciences SC Agriculture; Forestry; Meteorology & Atmospheric Sciences GA 377JQ UT WOS:000165510800020 ER PT J AU Reichardt, J Bisson, SE Reichardt, S Weitkamp, C Neidhart, B AF Reichardt, J Bisson, SE Reichardt, S Weitkamp, C Neidhart, B TI Rotational vibrational-rotational Raman differential absorption lidar for atmospheric ozone measurements: methodology and experiment SO APPLIED OPTICS LA English DT Article ID ICE CLOUDS; TROPOSPHERIC OZONE; AEROSOL AB A single-laser Raman differential absorption lidar (DIAL) for ozone measurements in clouds is proposed. An injection-locked XeCl excimer laser serves as the radiation source. The ozone molecule number density is calculated from the differential absorption of the anti-Stokes rotational Raman return signals from molecular nitrogen and oxygen as the on-resonance wavelength and the vibrational-rotational Raman backscattering from molecular nitrogen or oxygen as the off-resonance wavelength. Model calculations show that the main advantage of the new rotational vibrational-rotational (RVR) Raman DIAL over conventional Raman DIAL is a 70-85% reduction in the wavelength-dependent effects of cloud-particle scattering on the measured ozone concentration; furthermore the complexity of the apparatus is reduced substantially. We describe a RVR Raman DIAL setup that uses a narrow-band interference-filter polychromator as the lidar receiver. Single-laser ozone measurements in the troposphere and lower stratosphere are presented, and it is shown that on further improvement of the receiver performance, ozone measurements in clouds are attainable with the filter-polychromator approach. (C) 2000 Optical Society of America OCIS codes: 010.3640, 280.1910, 290.5860, 010.4950, 290.1090, 290.4210. C1 GKSS Forschungszentrum Geesthacht GmbH, Inst Phys & Chem Analyt, D-21494 Geesthacht, Germany. Sandia Natl Labs, Livermore, CA 94551 USA. RP Reichardt, J (reprint author), Univ Maryland Baltimore Cty, NASA, Goddard Space Flight Ctr, Joint Ctr Earth Syst Technol,Lab Atmospheres, Code 916, Greenbelt, MD 20771 USA. EM reichardt@code916.gsfc.nasa.gov; sebisso@sandia.gov; claus.weitkamp@gkss.de; bernd.neidhart@gkss.de NR 17 TC 8 Z9 8 U1 0 U2 1 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA SN 1559-128X EI 2155-3165 J9 APPL OPTICS JI Appl. Optics PD NOV 20 PY 2000 VL 39 IS 33 BP 6072 EP 6079 DI 10.1364/AO.39.006072 PG 8 WC Optics SC Optics GA 372WT UT WOS:000165257600003 PM 18354612 ER PT J AU Fischer, AJ Choquette, KD Chow, WW Allerman, AA Geib, KM AF Fischer, AJ Choquette, KD Chow, WW Allerman, AA Geib, KM TI Bistable output from a coupled-resonator vertical-cavity laser diode SO APPLIED PHYSICS LETTERS LA English DT Article ID SURFACE-EMITTING LASERS; POLARIZATION BISTABILITY; WAVELENGTH AB We report a monolithic coupled-resonator vertical-cavity laser with an ion-implanted top cavity and a selectively oxidized bottom cavity which exhibits bistable behavior in the light output versus injection current. Large bistability regions over current ranges as wide as 18 mA have been observed with on/off contrast ratios of greater than 20 dB. The position and width of the bistability region can be varied by changing the bias to the top cavity. Switching between on and off states can be accomplished with changes as small as 250 muW to the electrical power applied to the top cavity. The bistable behavior is the response of the nonlinear susceptibility in the top cavity to the changes in the bottom intracavity laser intensity as the bottom cavity reaches the thermal rollover point. (C) 2000 American Institute of Physics. [S0003-6951(00)00547-7]. C1 Sandia Natl Labs, Ctr Compound Semicond Sci & Technol, Albuquerque, NM 87185 USA. RP Fischer, AJ (reprint author), Sandia Natl Labs, Ctr Compound Semicond Sci & Technol, POB 5800, Albuquerque, NM 87185 USA. NR 16 TC 9 Z9 9 U1 0 U2 1 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD NOV 20 PY 2000 VL 77 IS 21 BP 3319 EP 3321 DI 10.1063/1.1326840 PG 3 WC Physics, Applied SC Physics GA 375JN UT WOS:000165395900001 ER PT J AU Ripalda, JM de Abajo, FJG Montero, I Galan, L Van Hove, MA AF Ripalda, JM de Abajo, FJG Montero, I Galan, L Van Hove, MA TI Photoelectron diffraction at the surface of amorphous carbon nitride SO APPLIED PHYSICS LETTERS LA English DT Article ID X-RAY PHOTOELECTRON; THIN-FILMS; ABSORPTION; CNX AB The line shape of N 1s photoemission spectra in a certain type of amorphous carbon nitride is shown to depend strongly on the polar angle of photoelectron emission. This effect is explained in terms of photoelectron forward scattering due to preferential orientation of bonds near the surface. An alternative model based on different indepth distributions for each of the nitrogen chemical species does not provide a satisfactory explanation of the observed angular dependence. The changes with polar emission angle of the photoelectron and Auger electron spectra are compared to elucidate the nature of each of the N 1s photoemission peaks. (C) 2000 American Institute of Physics. [S0003-6951(00)02947-8]. C1 Univ Autonoma Madrid, Dept Fis Aplicada, E-28049 Madrid, Spain. Univ Basque Country, Dept CCIA, San Sebastian 20080, Spain. CSIC, Inst Ciencia Mat, E-28049 Madrid, Spain. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Adv Light Source, Berkeley, CA 94720 USA. Univ Calif Davis, Dept Phys, Davis, CA 95616 USA. RP Ripalda, JM (reprint author), Univ Autonoma Madrid, Dept Fis Aplicada, E-28049 Madrid, Spain. EM josem.ripalda@uam.es RI Van Hove, Michel/A-9862-2008; Garcia de Abajo, Javier/A-6095-2009; CSIC-UPV/EHU, CFM/F-4867-2012; Ripalda, Jose/L-4708-2014; DONOSTIA INTERNATIONAL PHYSICS CTR., DIPC/C-3171-2014 OI Van Hove, Michel/0000-0002-8898-6921; Garcia de Abajo, Javier/0000-0002-4970-4565; Ripalda, Jose/0000-0003-3233-8308; NR 14 TC 6 Z9 6 U1 0 U2 2 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD NOV 20 PY 2000 VL 77 IS 21 BP 3394 EP 3396 AR PII [S0003-6951(00)02947-8] DI 10.1063/1.1328093 PG 3 WC Physics, Applied SC Physics GA 375JN UT WOS:000165395900026 ER PT J AU Weir, ST Akella, J Aracne-Ruddle, C Vohra, YK Catledge, SA AF Weir, ST Akella, J Aracne-Ruddle, C Vohra, YK Catledge, SA TI Epitaxial diamond encapsulation of metal microprobes for high pressure experiments SO APPLIED PHYSICS LETTERS LA English DT Article ID X-RAY-DIFFRACTION; ANVIL CELL; SUPERCONDUCTIVITY; METALLIZATION AB Diamond anvils with diamond encapsulated thin-film microcircuits have been fabricated for ultrahigh pressure electrical conductivity experiments. The diamond films were homoepitaxially deposited onto the diamond anvil substrates with microwave plasma chemical vapor deposition using a 2% methane in hydrogen gas mixture and a diamond substrate temperature of 1300 degreesC. The diamond embedded thin-film microprobes remain functional to megabar pressures. We have applied this technology to the study of the pressure-induced metallization of KI under pressures up to 1.8 Mbar. This technology has the potential of greatly advancing the pressure range of a number of existing high-pressure diagnostic techniques, and for expanding the capabilities of diamond anvil cells into new directions. (C) 2000 American Institute of Physics. [S0003-6951(00)00347-8]. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. Univ Alabama, Dept Phys, Birmingham, AL 35294 USA. RP Weir, ST (reprint author), Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RI Weir, Samuel/H-5046-2012 NR 20 TC 104 Z9 112 U1 2 U2 12 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD NOV 20 PY 2000 VL 77 IS 21 BP 3400 EP 3402 DI 10.1063/1.1326838 PG 3 WC Physics, Applied SC Physics GA 375JN UT WOS:000165395900028 ER PT J AU Su, X Stagarescu, C Xu, G Eastman, DE McNulty, I Frigo, SP Wang, YX Retsch, CC Noyan, IC Hu, CK AF Su, X Stagarescu, C Xu, G Eastman, DE McNulty, I Frigo, SP Wang, YX Retsch, CC Noyan, IC Hu, CK TI Quantitative nanoscale metrology study of Cu/SiO2 interconnect technology using transmission x-ray microscopy SO APPLIED PHYSICS LETTERS LA English DT Article ID COPPER INTERCONNECTIONS; RELIABILITY AB This letter describes quantitative nondestructive measurements of multilayer submicron Cu/SiO2 interconnect structures such as Cu lines, vias, and W lines with lateral dimensions down to 300 nm and electromigration defect structures using scanning transmission x-ray microscopy employing a 0.2 mum x-ray beam. Typical measurement accuracies are less than or equal to 60 nm for widths and lengths and less than or equal to 10% in height. The high-resolution and nondestructive nature of this technique provide a very powerful probe of physical properties of nanoscale and submicron materials and structures. (C) 2000 American Institute of Physics. [S0003-6951(00)05546-7]. C1 Univ Chicago, James Franck Inst, Chicago, IL 60637 USA. Argonne Natl Lab, Adv Photon Source, Argonne, IL 60439 USA. IBM Corp, TJ Watson Res Ctr, Yorktown Heights, NY 10589 USA. RP Eastman, DE (reprint author), Univ Chicago, James Franck Inst, 5640 S Ellis Ave, Chicago, IL 60637 USA. RI Xu, Guangyong/A-8707-2010 OI Xu, Guangyong/0000-0003-1441-8275 NR 14 TC 15 Z9 15 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD NOV 20 PY 2000 VL 77 IS 21 BP 3465 EP 3467 DI 10.1063/1.1326489 PG 3 WC Physics, Applied SC Physics GA 375JN UT WOS:000165395900050 ER PT J AU Blanton, M AF Blanton, M TI How stochastic is the relative bias between galaxy types? SO ASTROPHYSICAL JOURNAL LA English DT Article DE galaxies : clusters : general; large-scale structure of universe ID CAMPANAS REDSHIFT SURVEY; MORPHOLOGICAL SEGREGATION; LUMINOSITY FUNCTION; CATALOG; DENSITY AB Examining the nature of the relative clustering of different galaxy types can help tell us how galaxies formed. To measure this relative clustering, I perform a joint counts-in-cells analysis of galaxies of different spectral types in the Las Campanas Redshift Survey (LCRS). I develop a maximum-likelihood technique to fit for the relationship between the density fields of early- and late-type galaxies. This technique can directly measure nonlinearity and stochasticity in the biasing relation. At high significance, a small amount of stochasticity is measured, corresponding to a correlation coefficient r approximate to 0.87 on scales corresponding to 15 h(-1) Mpc spheres. A large proportion of this signal appears to derive from errors in the selection function, and a more realistic estimate finds r approximate to 0.95. These selection function errors probably account for the large stochasticity measured by Tegmark & Bromley, and may have affected measurements of very large-scale structure in the LCRS. Analysis of the data and of mock catalogs shows that the peculiar geometry, variable flux limits, and central surface brightness selection effects of the LCRS do not seem to cause the effect. C1 Princeton Univ Observ, Princeton, NJ 08544 USA. NASA, Fermi Natl Accelerator Lab, Fermilab Astrophys Ctr, Batavia, IL 60510 USA. SUNY Stony Brook, Dept Phys & Astron, Stony Brook, NY 11794 USA. RP Blanton, M (reprint author), Princeton Univ Observ, Peyton Hall, Princeton, NJ 08544 USA. NR 34 TC 23 Z9 23 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD NOV 20 PY 2000 VL 544 IS 1 BP 63 EP 80 DI 10.1086/317198 PN 1 PG 18 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 381FH UT WOS:000165751300007 ER PT J AU Gregg, MD Becker, RH Brotherton, MS Laurent-Muehleisen, SA Lacy, M White, RL AF Gregg, MD Becker, RH Brotherton, MS Laurent-Muehleisen, SA Lacy, M White, RL TI Discovery of a classic FR II broad absorption line quasar from the FIRST survey SO ASTROPHYSICAL JOURNAL LA English DT Article DE quasars : absorption lines; quasars : general; quasars : individual (FIRST J101614.3+520916) ID C-IV ABSORPTION; RADIO-SOURCES; STELLAR OBJECTS; STEEP-SPECTRUM; SKY SURVEY; QSO; GALAXIES; REDSHIFT; EXTINCTION; SYSTEMS AB We have discovered a remarkable quasar, FIRST J101614.3+520916, whose optical spectrum shows unambiguous broad absorption features, while its double-lobed radio morphology and luminosity clearly indicate a classic Fanaroff-Riley type II radio source. Its radio luminosity places it at the extreme of the recently established class of radio-loud broad absorption line quasars. Because of its hybrid nature we speculate that FIRST J101614.3+520916 is a typical FR II quasar that has been rejuvenated as a broad absorption line (BAL) quasar with a compact steep spectrum core. The direction of the jet axis of FIRST J101614.3+520916 can be estimated from its radio structure and optical brightness, indicating that we are viewing the system at a viewing angle of greater than or similar to 40 degrees. The position angles of the radio jet and optical polarization are not well aligned, differing by similar to 20 degrees -30 degrees. When combined with the evidence presented by Becker and coworkers for a sample of 29 BAL quasars showing that at least some BAL quasars are viewed along the jet axis, the implication is that no preferred viewing orientation is necessary to observe BAL systems in a quasar's spectrum. This, and the probable young nature of compact steep spectrum sources, leads naturally to the alternate hypothesis that BALs are an early stage in the lives of quasars. C1 Univ Calif Davis, Dept Phys, Davis, CA 95616 USA. Univ Calif Lawrence Livermore Natl Lab, Inst Geophys & Planetary Phys, Livermore, CA 94550 USA. Natl Opt Astron Observ, Tucson, AZ 85726 USA. Space Telescope Sci Inst, Baltimore, MD 21218 USA. RP Gregg, MD (reprint author), Univ Calif Davis, Dept Phys, 1 Shields Ave, Davis, CA 95616 USA. NR 43 TC 49 Z9 49 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD NOV 20 PY 2000 VL 544 IS 1 BP 142 EP 149 DI 10.1086/317194 PN 1 PG 8 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 381FH UT WOS:000165751300014 ER PT J AU Wood, KS Ray, PS Bandyopadhyay, RM Wolff, MT Fritz, G Hertz, P Kowalski, MP Lovellette, MN Yentis, D Bloom, ED Giebels, B Godfrey, G Reilly, K Parkinson, PS Shabad, G Scargle, J AF Wood, KS Ray, PS Bandyopadhyay, RM Wolff, MT Fritz, G Hertz, P Kowalski, MP Lovellette, MN Yentis, D Bloom, ED Giebels, B Godfrey, G Reilly, K Parkinson, PS Shabad, G Scargle, J TI USA experiment and RXTE observations of a variable low-frequency quasi-periodic oscillation in XTE J1118+480 SO ASTROPHYSICAL JOURNAL LA English DT Article DE binaries : general; stars : individual (XTE J1118+480) ID RAY TIMING EXPLORER AB Using the USA Experiment on the Advanced Research and Global Observation Satellite and the Rossi X-Ray Timing Explorer, we have extensively observed the X-ray transient XTE J1118+480 during its recent outburst in 2000 April-June. We present detailed monitoring of the evolution of a low-frequency quasi-periodic oscillation (QPO) that drifts from 0.07 to 0.15 Hz during the outburst. We examine possible correlations of the QPO frequency with the flux and spectral characteristics of the source, and we compare this QPO with low-frequency QPOs observed in other black hole candidates. C1 USN, Res Lab, EO Hulburt Ctr Space Res, Washington, DC 20375 USA. Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Wood, KS (reprint author), USN, Res Lab, EO Hulburt Ctr Space Res, Washington, DC 20375 USA. OI Ray, Paul/0000-0002-5297-5278 NR 16 TC 31 Z9 31 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD NOV 20 PY 2000 VL 544 IS 1 BP L45 EP L48 DI 10.1086/317287 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 381GB UT WOS:000165753000010 ER PT J AU Warner, BP D'Alessio, JA Morgan, AN Burns, CJ Schake, AR Watkin, JG AF Warner, BP D'Alessio, JA Morgan, AN Burns, CJ Schake, AR Watkin, JG TI Plutonium(III)-catalyzed Meerwein-Ponndorf-Verley reactions SO INORGANICA CHIMICA ACTA LA English DT Article DE plutonium; actinide; Meerwein-Ponndorf-Verley; catalyst ID RAY CRYSTAL-STRUCTURES; ALKOXIDE CHEMISTRY; LANTHANIDE ALKOXIDES; OPPENAUER REACTIONS; COMPLEXES; URANIUM(IV); REDUCTION; ABSORPTION; CATALYST; THORIUM AB The reactivity of Th(IV), U(III), U(IV), Pu(III) and Pu(IV) iso-propoxide in the Meerwein-Ponndorf-Verley reduction of ketones by iso-propanol have been examined. Plutonium(III) iso-propoxide is found to be an effective catalyst for the reduction of a range of substituted aryl-alkyl ketones, while An(IV) iso-propoxides (An = Th, U, Pu) are found to be inactive. U(III) was found to oxidize under the reaction conditions to a U(IV) complex, which was also catalytically inactive. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Univ Calif Los Alamos Natl Lab, Chem Sci & Technol Div CST18, Los Alamos, NM 87545 USA. Univ Calif Los Alamos Natl Lab, Nucl Mat Technol Div NMT11, Los Alamos, NM 87545 USA. Univ Calif Los Alamos Natl Lab, Chem Sci & Technol Div CSTDO, Los Alamos, NM 87545 USA. Univ Calif Los Alamos Natl Lab, Nucl Mat Technol Div NMT5, Los Alamos, NM 87545 USA. RP Warner, BP (reprint author), Univ Calif Los Alamos Natl Lab, Chem Sci & Technol Div CST18, Mailstop J514, Los Alamos, NM 87545 USA. NR 51 TC 12 Z9 12 U1 1 U2 8 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0020-1693 J9 INORG CHIM ACTA JI Inorg. Chim. Acta PD NOV 20 PY 2000 VL 309 IS 1-2 BP 45 EP 48 DI 10.1016/S0020-1693(00)00227-9 PG 4 WC Chemistry, Inorganic & Nuclear SC Chemistry GA 380NQ UT WOS:000165708300006 ER PT J AU Lumetta, GJ McNamara, BK Rapko, BM Sell, RL Rogers, RD Broker, G Hutchison, JE AF Lumetta, GJ McNamara, BK Rapko, BM Sell, RL Rogers, RD Broker, G Hutchison, JE TI Synthesis and characterization of mono- and bis-(tetraalkylmalonamide)uranium(VI) complexes SO INORGANICA CHIMICA ACTA LA English DT Article DE uranium; diamide; malonamide ID NITRIC-ACID SOLUTION; SOLVENT-EXTRACTION; CHEMICAL SEPARATIONS; N,N,N',N'-TETRAALKYL-2-ALKYL-PROPANE-1,3-DIAMIDES; N,N-DIALKYLAMIDES; MALONAMIDES; ACTINIDES; PU(IV); AGENTS; U(VI) AB The complex [UO2(NO3)(2)(TMMA)] (TMMA = N,N,N',N'-tetramethylmalonamide) was structurally characterized by single-crystal X-ray diffraction. The complex consists of two bidentate nitrate ions and one bidentate TMMA ligand coordinated to the UO22+ ion. The complex [UO2(THMA)(2)](2+) (THMA = N,N,N',N'-tetrahexylmalonamide) was prepared as the BF4- salt; this material tended to form an oil. However, [UO2(TMMA)(2)](OTf)(2) (OTf = triflate) was isolated as a crystalline solid. Comparison of the Fourier transform infrared spectra of these complexes to the spectra of complexes formed in liquid-liquid extraction systems supports the hypothesis that complexes of the type [UO2(NO3)(2)L] and [UO2L2](NO3)(2) (L = diamide extractant) form in the extraction systems. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Pacific NW Natl Lab, Richland, WA 99352 USA. Univ Alabama, Dept Chem, Tuscaloosa, AL 35487 USA. Univ Oregon, Dept Chem, Eugene, OR 97403 USA. RP Lumetta, GJ (reprint author), Pacific NW Natl Lab, POB 999, Richland, WA 99352 USA. RI Rogers, Robin/C-8265-2013 OI Rogers, Robin/0000-0001-9843-7494 NR 27 TC 23 Z9 24 U1 1 U2 4 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0020-1693 J9 INORG CHIM ACTA JI Inorg. Chim. Acta PD NOV 20 PY 2000 VL 309 IS 1-2 BP 103 EP 108 DI 10.1016/S0020-1693(00)00253-X PG 6 WC Chemistry, Inorganic & Nuclear SC Chemistry GA 380NQ UT WOS:000165708300014 ER EF