FN Thomson Reuters Web of Science™ VR 1.0 PT J AU Wenzel, WW Kirchbaumer, N Prohaska, T Stingeder, G Lombi, E Adriano, DC AF Wenzel, WW Kirchbaumer, N Prohaska, T Stingeder, G Lombi, E Adriano, DC TI Arsenic fractionation in soils using an improved sequential extraction procedure SO ANALYTICA CHIMICA ACTA LA English DT Article DE sequential extraction; arsenic; soil analysis; chemical fractionation ID CHROMATE RETENTION MECHANISMS; TRACE-METALS; SURFACE-CHEMISTRY; ADSORPTION; PHOSPHATE; FERRIHYDRITE; PHOSPHORUS; SPECIATION; SEDIMENTS; SORPTION AB Risk assessment of contaminants requires simple, meaningful tools to obtain information on contaminant pools of differential lability and bioavailability in the soil. We developed and tested a sequential extraction procedure (SEP) for As by choosing extraction reagents commonly used for sequential extraction of metals, Se and P. Tests with alternative extractants that have been used in SEPs for P and metals, including NH4NO3, NaOAc, NH2OH . HCl, EDTA, NH4OH and NH4F were shown to either have only low extraction efficiency for As, or to be insufficiently selective or specific for the phases targeted. The final sequence obtained includes the following five extraction steps: (1) 0.05 M (NH4)(2)SO4, 20 degreesC/4 h; (2) 0.05 M NH4H2PO4, 20 degreesC/16 h; (3) 0.2 M NH4+-oxalate buffer in the dark, pH 3.25, 20 degreesC/4h; (4) 0.2 M NH4+-oxalate buffer + ascorbic acid, pH 3.25, 96 degreesC/0.5 h; (5) HNO3/H2O2 microwave digestion. Within the inherent limitations of chemical fractionation, these As fractions appear to be primarily associated with (1) non-specifically sorbed; (2) specifically-sorbed; (3) amorphous and poorly-crystalline hydrous oxides of Fe and Al; (4) well-crystallized hydrous oxides of Fe and Al; and (5) residual phases. This interpretation is supported by selectivity and specificity tests on soils and pure mineral phases, and by energy dispersive X-ray microanalysis (EDXMA) of As in selected soils. Partitioning of As among these five fractions in 20 soils was (%, medians and ranges): (1) 0.24 (0.02-3.8); (2) 9.5 (2.6-25); (3) 42.3 (12-73); (4) 29.2 (13-39); and(5) 17.5 (1.1-38). The modified SEP is easily adaptable in routine soil analysis, is dependable as indicated by repeatability (w greater than or equal to 0.98) and recovery tests. This SEP can be useful in predicting the changes in the lability of As in various solid phases as a result of soil remediation or alteration in environmental factors. (C) 2001 Elsevier Science B.V. All rights reserved. C1 Agr Univ Vienna, Inst Soil Sci, BOKU, A-1180 Vienna, Austria. Agr Univ Vienna, Inst Chem, BOKU, A-1190 Vienna, Austria. IACR Rothamsted, Dept Soil Sci, Harpenden AL5 2JQ, Herts, England. Univ Georgia, Savannah River Ecol Lab, Aiken, SC 29801 USA. RP Wenzel, WW (reprint author), Agr Univ Vienna, Inst Soil Sci, BOKU, Gregor Mendel Str 33, A-1180 Vienna, Austria. RI Lombi, Enzo/F-3860-2013 OI Lombi, Enzo/0000-0003-3384-0375 NR 46 TC 456 Z9 494 U1 42 U2 290 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0003-2670 J9 ANAL CHIM ACTA JI Anal. Chim. Acta PD JUN 12 PY 2001 VL 436 IS 2 BP 309 EP 323 DI 10.1016/S0003-2670(01)00924-2 PG 15 WC Chemistry, Analytical SC Chemistry GA 442GE UT WOS:000169276200015 ER PT J AU Rose, J Moulin, I Masion, A Bertsch, PM Wiesner, MR Bottero, JY Mosnier, F Haehnel, C AF Rose, J Moulin, I Masion, A Bertsch, PM Wiesner, MR Bottero, JY Mosnier, F Haehnel, C TI X-ray absorption spectroscopy study of immobilization processes for heavy metals in calcium silicate hydrates. 2. Zinc SO LANGMUIR LA English DT Article ID PORTLAND-CEMENT; LEAD; GEL AB Tricalcium silicate (C3S), the major phase of cement-based materials, contains naturally a few hundred parts per million of heavy metals. An X-ray absorption spectroscopy (XAS) study at the Zn K-edge has been carried out to elucidate the binding mechanisms of Zn by calcium silicate hydrates, which is important to predict the long-term behavior of Zn. At low concentration, under the threshold of precipitation of the oxide, oxy hydroxide, and calcium zinc hydroxide, no retardation of the hydration of the C3S has been observed for C3S doped with Zn. A previous Si-29 NMR (Moulin, I.; Stone, W. E. E.; Sanz, J.; Bottero, J.-Y.; Mosnier, J-Y.; Haehnel, C. Langmuir 1999, 151 2829-2835) study has demonstrated that the structure of the hydrated CBS (called C-S-H for calcium silicate hydrates) does not change if Zn is present initially or not. XAS experiments have shown that Zn tetrahedra are incorporated within the matrix of C-S-H and linked directly at the end of the silicate chains through Zn-O-Si bonds. The Zn-Si distance is approximate to3.1 Angstrom. Extended X-ray absorption fine structure results have been confirmed by ab initio calculations including multiple scattering. C1 Univ Aix Marseille 3, CNRS, UMR 6635, CEREGE,Equipe Physicochim Interfaces, F-13545 Aix En Provence 4, France. Univ Georgia, SREL, Aiken, SC 29802 USA. Rice Univ, Dept Environm Sci & Engn, Houston, TX 77005 USA. CIRSEE, F-78230 Le Pecq, France. ATILH Def 4, F-92974 Parisla Defense, France. RP Rose, J (reprint author), Univ Aix Marseille 3, CNRS, UMR 6635, CEREGE,Equipe Physicochim Interfaces, Europole Mediterraneen Arbois,BP 80, F-13545 Aix En Provence 4, France. NR 22 TC 31 Z9 31 U1 3 U2 18 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0743-7463 J9 LANGMUIR JI Langmuir PD JUN 12 PY 2001 VL 17 IS 12 BP 3658 EP 3665 DI 10.1021/la001302h PG 8 WC Chemistry, Multidisciplinary; Chemistry, Physical; Materials Science, Multidisciplinary SC Chemistry; Materials Science GA 440AE UT WOS:000169150100025 ER PT J AU Wang, J Caffrey, M Bedzyk, MJ Penner, TL AF Wang, J Caffrey, M Bedzyk, MJ Penner, TL TI Direct profiling and reversibility of ion distribution at a charged membrane/aqueous interface: An X-ray standing wave study SO LANGMUIR LA English DT Article ID DIFFUSE-DOUBLE-LAYER; LIPID-MEMBRANES; MODEL MEMBRANES; DIFFRACTION; FLUORESCENCE; DAMAGE; FILMS; GOLD AB Thermodynamic reversibility of ion binding at a membrane/aqueous interface has been demonstrated using-variable period X-ray standing waves generated above a gold mirror. The interface consists of-a negatively charged and polymerized phospholipid monolayer bathed in a dilute zinc chloride solution. Zinc ion distribution in the diffuse double layer was monitored as the pH of the aqueous medium was titrated from a value of 5.8 to 2.0 and back again to pH 5.8. The ion distribution was modeled by an exponentially decaying function. As Hf concentration increased upon changing pH from 5.8 to 2.0, the amount of zinc in the diffuse double layer (integrated as a two-dimensional projection along the surface normal) decreased from 1.4 x 10(13) to 1.0 x 10(12) ions/cm(2) and the concentration of bound zinc at the surface dropped by a factor of 6.4 from an initial value of 122 mM to a low of ca. 19 mM. Recovery of the pH 5.8 distribution profile was essentially complete upon back-titration from pH 2.0. These results demonstrate clearly that within the experimental error of the measurement ion distribution at the charged membrane interface is reversible upon adjusting the pH of the electrolyte solution which Corresponds to altering the degree of protonation and, thus, the net charge on the exposed phosphate headgroups. C1 Ohio State Univ, Columbus, OH 43210 USA. Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. Northwestern Univ, Dept Mat Sci & Engn, Evanston, IL 60208 USA. Eastman Kodak Co, Rochester, NY 14650 USA. RP Wang, J (reprint author), Argonne Natl Lab, Adv Photon Source, 9700 S Cass Ave, Argonne, IL 60439 USA. RI Bedzyk, Michael/B-7503-2009; Bedzyk, Michael/K-6903-2013 NR 40 TC 20 Z9 20 U1 1 U2 5 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0743-7463 J9 LANGMUIR JI Langmuir PD JUN 12 PY 2001 VL 17 IS 12 BP 3671 EP 3681 DI 10.1021/la001542x PG 11 WC Chemistry, Multidisciplinary; Chemistry, Physical; Materials Science, Multidisciplinary SC Chemistry; Materials Science GA 440AE UT WOS:000169150100027 ER PT J AU Kim, CC Kim, JK Lee, JL Je, JH Yi, MS Noh, DY Hwu, Y Ruterana, P AF Kim, CC Kim, JK Lee, JL Je, JH Yi, MS Noh, DY Hwu, Y Ruterana, P TI Catalytic role of Au in Ni/Au contact on GaN(0001) SO APPLIED PHYSICS LETTERS LA English DT Article ID P-TYPE GAN; FIELD-EFFECT TRANSISTORS; DIODES; LAYER; NI AB We investigated the structural behavior of the Ni/Au contact on GaN(0001) and found the catalytic role of Au during annealing, using in situ x-ray scattering. The oxidation kinetics of Ni during annealing in air was greatly affected by the presence of Au. The accelerated GaN decomposition and Ni nitride formation during annealing in N-2 also provide evidence of the catalytic role of Au. The results suggest that oxidized Ni/Au ohmic contact exhibit better thermal stability than that of the N-2 annealed Ni/Au contacts. (C) 2001 American Institute of Physics. C1 Pohang Univ Sci & Engn, Dept Mat Sci & Engn, Pohang, South Korea. Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. Kwangju Inst Sci & Technol, Dept Mat Sci & Engn, Kwangju, South Korea. Kwangju Inst Sci & Technol, Ctr Elect Mat Res, Kwangju, South Korea. Acad Sinica, Inst Phys, Taipei 11529, Taiwan. ISMRA, Equipe Struct & Comportement Thermomecan Mat, CRISMAT, CNRS,UMR 6508, F-14050 Caen, France. RP Kim, CC (reprint author), Pohang Univ Sci & Engn, Dept Mat Sci & Engn, Pohang, South Korea. RI LEE, JONG-LAM/F-7334-2010 NR 16 TC 12 Z9 13 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 JUN 11 PY 2001 VL 78 IS 24 BP 3773 EP 3775 DI 10.1063/1.1379064 PG 3 WC Physics, Applied SC Physics GA 441JA UT WOS:000169226200003 ER PT J AU Mahan, AH Xu, Y Nelson, BP Crandall, RS Cohen, JD Palinginis, KC Gallagher, AC AF Mahan, AH Xu, Y Nelson, BP Crandall, RS Cohen, JD Palinginis, KC Gallagher, AC TI Saturated defect densities of hydrogenated amorphous silicon grown by hot-wire chemical vapor deposition at rates up to 150 angstrom/s SO APPLIED PHYSICS LETTERS LA English DT Article ID SOLAR-CELL; FILMS AB Hydrogenated amorphous-silicon (alpha -Si:H) is grown by hot-wire chemical vapor deposition (HWCVD) at deposition rates (R-d) exceeding 140 Angstrom /s (similar to0.8 mum/min). These high rates ore achieved by using multiple filaments and deposition conditions different than those used to produce our standard 20 Angstrom /s material, with proper deposition parameter optimization, an AM1.5 photo-to-dark-conductivity ratio of 10(5) is maintained at an R-d up to 130 Angstrom /s, beyond which it decreases. In addition, the first saturated defect densities of high R-d alpha -Si:H films are presented. These saturated defected densities are similar to those of the best HWCVD films deposited at 5-8 Angstrom /s, and are invariant with R-d up to 130 Angstrom /s. (C) 2001 American Institute of Physics. C1 Natl Renewable Energy Lab, Golden, CO 80401 USA. Univ Oregon, Dept Phys, Eugene, OR 97403 USA. Univ Colorado, Boulder, CO 80309 USA. NIST, Boulder, CO 80309 USA. RP Mahan, AH (reprint author), Natl Renewable Energy Lab, Golden, CO 80401 USA. NR 18 TC 22 Z9 22 U1 1 U2 4 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 JUN 11 PY 2001 VL 78 IS 24 BP 3788 EP 3790 DI 10.1063/1.1375008 PG 3 WC Physics, Applied SC Physics GA 441JA UT WOS:000169226200008 ER PT J AU Lim, SH Washburn, J Liliental-Weber, Z Qiao, D AF Lim, SH Washburn, J Liliental-Weber, Z Qiao, D TI Microstructural evidence on electrical properties of Ta/Ti/Al and Ti/Ta/Al ohmic contacts to n-AlGaN/GaN SO APPLIED PHYSICS LETTERS LA English DT Article ID GAN; RESISTANCE; DIODES; TI/AL AB Electrical properties and microstructures of Ta/Ti/Al and Ti/Ta/Al contacts to n-AlGaN/GaN heterostructure held-effect transistor structures were investigated using the transmission line method and transmission electron microscopy. The specific resistivity (5.3 X 10(-7) Ohm cm(2)) of Ta/Ti/Al contacts is much lower than that (5.1 X 10(-4) Ohm cm(2)) of Ti/Ta/Al contacts, for the same heterostructure and similar metallization. The contact resistivity was found to depend on the thickness of the AlGaN layer, interfacial phase, and interface roughness. The formation of interfacial phases by solid-state reactions with the metal layer during annealing appears to be essential for ohmic behavior on n-III-nitrides suggesting a tunneling contact mechanism. (C) 2001 American Institute of Physics. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. Univ Calif San Diego, La Jolla, CA 92093 USA. RP Lim, SH (reprint author), Univ Calif Santa Barbara, Dept Mat, Santa Barbara, CA 93106 USA. RI Liliental-Weber, Zuzanna/H-8006-2012 NR 11 TC 40 Z9 42 U1 0 U2 13 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 JUN 11 PY 2001 VL 78 IS 24 BP 3797 EP 3799 DI 10.1063/1.1378312 PG 3 WC Physics, Applied SC Physics GA 441JA UT WOS:000169226200011 ER PT J AU Dernburg, AF AF Dernburg, AF TI Here, there, and everywhere: Kinetochore function on holocentric chromosomes SO JOURNAL OF CELL BIOLOGY LA English DT Editorial Material ID CAENORHABDITIS-ELEGANS; CELL-DIVISION; C-ELEGANS; PROTEIN; CENTROMERE; ORGANIZATION; CONSERVATION; SEGREGATION; CYTOKINESIS; COMPLEX C1 Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Mol & Cell Biol, Berkeley, CA 94720 USA. RP Dernburg, AF (reprint author), Lawrence Berkeley Natl Lab, 1 Cyclotron Rd,Ms 84-171, Berkeley, CA 94720 USA. NR 36 TC 59 Z9 63 U1 0 U2 2 PU ROCKEFELLER UNIV PRESS PI NEW YORK PA 1114 FIRST AVE, 4TH FL, NEW YORK, NY 10021 USA SN 0021-9525 J9 J CELL BIOL JI J. Cell Biol. PD JUN 11 PY 2001 VL 153 IS 6 BP F33 EP F38 DI 10.1083/jcb.153.6.F33 PG 6 WC Cell Biology SC Cell Biology GA 443AX UT WOS:000169318100002 PM 11402076 ER PT J AU Bussmann-Holder, A Bishop, AR Buttner, H Egami, T Micnas, R Muller, KA AF Bussmann-Holder, A Bishop, AR Buttner, H Egami, T Micnas, R Muller, KA TI The phase diagram of high-T-c superconductors in the presence of dynamic stripes SO JOURNAL OF PHYSICS-CONDENSED MATTER LA English DT Letter ID HIGH-TEMPERATURE SUPERCONDUCTIVITY; CUPRATE SUPERCONDUCTORS; SPIN FLUCTUATIONS; SINGLE-CRYSTALS; CUO2 PLANE; LATTICE; CHARGE; MODEL; YBA2CU3O7-DELTA; YBA2CU3O6+X AB The phase diagram of superconducting copper oxides is calculated as a function of doping on the basis of a theory of dynamic stripe-induced superconductivity. The two major conclusions from the theory and the numerical analysis are that T-* (the pseudogap onset temperature) and T, (the superconductivity onset temperature) are correlated through the pseudogap, which induces a gap in the single-particle energies that persists into the superconducting state. On decreasing the doping the pseudogap hr increases and T-* increases, but when Delta (*) exceeds a certain critical value the superconducting transition temperature T-c is lowered. A mixed s- and d-wave pairing symmetry is also examined as a function of doping. C1 Max Planck Inst Festkorperforsch, D-70569 Stuttgart, Germany. Univ Calif Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. Univ Bayreuth, Lehrstuhl Theoret Phys 1, D-95440 Bayreuth, Germany. Univ Penn, Dept Mat Sci, Philadelphia, PA 19104 USA. Adam Mickiewicz Univ, Inst Phys, PL-61614 Poznan, Poland. Univ Zurich, Inst Phys, CH-8057 Zurich, Switzerland. RP Bussmann-Holder, A (reprint author), Max Planck Inst Festkorperforsch, Heisenbergstr 1, D-70569 Stuttgart, Germany. RI Micnas, Roman/E-9668-2015 NR 56 TC 27 Z9 27 U1 1 U2 4 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0953-8984 J9 J PHYS-CONDENS MAT JI J. Phys.-Condes. Matter PD JUN 11 PY 2001 VL 13 IS 23 BP L545 EP L551 DI 10.1088/0953-8984/13/23/103 PG 7 WC Physics, Condensed Matter SC Physics GA 449CC UT WOS:000169665900003 ER PT J AU Adams, G Burkert, V Carl, R Carstens, T Frolov, V Houghtlin, L Jacobs, G Kossov, M Klusman, M Kross, B Onuk, M Napolitano, J Price, JW Riggs, C Sharabian, Y Stavinsky, A Smith, LC Stephens, WA Stoler, P Tuzel, W Ullrich, K Vlassov, A Weisenberger, A Witkowski, M Wojtekhowski, B Yergin, PF Zorn, C AF Adams, G Burkert, V Carl, R Carstens, T Frolov, V Houghtlin, L Jacobs, G Kossov, M Klusman, M Kross, B Onuk, M Napolitano, J Price, JW Riggs, C Sharabian, Y Stavinsky, A Smith, LC Stephens, WA Stoler, P Tuzel, W Ullrich, K Vlassov, A Weisenberger, A Witkowski, M Wojtekhowski, B Yergin, PF Zorn, C TI The CLAS Cherenkov detector SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article DE detector; Cherenkov; gas; threshold AB The design, construction, and performance of the CLAS Chrenkov threshold gas detector at Jefferson Lab is described. The detector consists of 216 optical modules. Each module consists of the of three adjustable mirrors of lightweight composite construction. a Winston light collecting cone, a 5-in. photomiltiplier tube, and specially designed magnetic shielding. Efficiencies and response functions have been measured. (C) 2001 Elsevier Science B.V. All rights reserved. C1 Rensselaer Polytech Inst, Dept Phys, Troy, NY 12180 USA. Thomas Jefferson Natl Accelerator Facil, Newport News, VA 23606 USA. Inst Theoret & Expt Phys, Moscow 117259, Russia. Yerevan Phys Inst, Yerevan 375036, Armenia. Univ Virginia, Dept Phys, Charlottesville, VA 22904 USA. RP Stoler, P (reprint author), Rensselaer Polytech Inst, Dept Phys, Troy, NY 12180 USA. NR 8 TC 42 Z9 42 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 JUN 11 PY 2001 VL 465 IS 2-3 BP 414 EP 427 DI 10.1016/S0168-9002(00)01313-9 PG 14 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 445GD UT WOS:000169449000012 ER PT J AU Alavi-Harati, A 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 Hamm, J Hanagaki, K Hidaka, S Hsiung, YB Jejer, V Jensen, DA Kessler, R Kobrak, HGE LaDue, J Lath, A Ledovskoy, A McBride, PL Mikelsons, P Monnier, E Nakaya, T Nelson, KS Nguyen, H O'Dell, V Pang, M Pordes, R Prasad, V Quinn, B Ramberg, EJ Ray, RE Roodman, A Sadamoto, M Schnetzer, S Senyo, K Shanahan, P Shawhan, PS Shields, J Slater, W Solomey, N Somalwar, SV Stone, RL Swallow, EC Taegar, SA Tesarek, RJ Thomson, GB Toale, PA Tripathi, A Tschirhart, R Turner, SE Wah, YW Wang, J White, HB Whitmore, J Winstein, B Winston, R Yamanaka, T Zimmerman, ED AF Alavi-Harati, A 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 Hamm, J Hanagaki, K Hidaka, S Hsiung, YB Jejer, V Jensen, DA Kessler, R Kobrak, HGE LaDue, J Lath, A Ledovskoy, A McBride, PL Mikelsons, P Monnier, E Nakaya, T Nelson, KS Nguyen, H O'Dell, V Pang, M Pordes, R Prasad, V Quinn, B Ramberg, EJ Ray, RE Roodman, A Sadamoto, M Schnetzer, S Senyo, K Shanahan, P Shawhan, PS Shields, J Slater, W Solomey, N Somalwar, SV Stone, RL Swallow, EC Taegar, SA Tesarek, RJ Thomson, GB Toale, PA Tripathi, A Tschirhart, R Turner, SE Wah, YW Wang, J White, HB Whitmore, J Winstein, B Winston, R Yamanaka, T Zimmerman, ED TI Measurements of the rare decay K-L -> e(+)e(-)e(+)e(-) SO PHYSICAL REVIEW LETTERS LA English DT Article ID BRANCHING RATIO; FORM-FACTOR; K-L->PI(+)PI(-)E(+)E(-); CP AB We observe 441 K-L --> e(+)e(-)e(+)e(-) candidate events with a background of 4.2 events and measure B(K-L --> e(+)e(-)e(+)e(-)) = [3.72 +/- 0.18(stat) +/- 0.23(syst)] X 10(-8) in the KTeV/E799II experiment at Fermilab. Using the distribution of the angle between the planes of the e(+)e(-) pairs, we measure the CP parameters beta (CP) = -0.23 +/- 0.09(stat) +/- 0.02(syst) and gamma (CP) = -0.09 +/- 0.09(stat) +/- 0.02(syst). We also present the first detailed study of the e(+)e(-) invariant mass spectrum in this decay mode. C1 Rutgers State Univ, Piscataway, NJ 08854 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, Toyonaka, Osaka 5600043, 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 Halkiadakis, E (reprint author), Rutgers State Univ, Piscataway, NJ 08854 USA. NR 13 TC 19 Z9 19 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD JUN 11 PY 2001 VL 86 IS 24 BP 5425 EP 5429 DI 10.1103/PhysRevLett.86.5425 PG 5 WC Physics, Multidisciplinary SC Physics GA 441PV UT WOS:000169239500005 PM 11415267 ER PT J AU Fleming, BT Adams, T Alton, H Arroyo, CG Avvakumov, S de Barbaro, L de Barbaro, P Bazarko, AO Bernstein, RH Bodek, A Bolton, T Brau, J Buchholz, D Budd, H Bugel, L Conrad, J Drucker, RB Formaggio, JA Frey, R Goldman, J Goncharov, M Harris, DA Johnson, RA Kim, JH King, BJ Kinnel, T Koutsoliotas, S Lamm, MJ Marsh, W Mason, D McFarland, KS McNulty, C Mishra, SR Naples, D Nienaber, P Romosan, A Sakumoto, WK Schellman, H Sciulli, FJ Seligman, WG Shaevitz, MH Smith, WH Spentzouris, P Stern, EC Suwonjandee, N Vaitaitis, A Vakili, M Yang, UK Yu, J Zeller, GP Zimmerman, ED AF Fleming, BT Adams, T Alton, H Arroyo, CG Avvakumov, S de Barbaro, L de Barbaro, P Bazarko, AO Bernstein, RH Bodek, A Bolton, T Brau, J Buchholz, D Budd, H Bugel, L Conrad, J Drucker, RB Formaggio, JA Frey, R Goldman, J Goncharov, M Harris, DA Johnson, RA Kim, JH King, BJ Kinnel, T Koutsoliotas, S Lamm, MJ Marsh, W Mason, D McFarland, KS McNulty, C Mishra, SR Naples, D Nienaber, P Romosan, A Sakumoto, WK Schellman, H Sciulli, FJ Seligman, WG Shaevitz, MH Smith, WH Spentzouris, P Stern, EC Suwonjandee, N Vaitaitis, A Vakili, M Yang, UK Yu, J Zeller, GP Zimmerman, ED TI First measurement of the low-x, low-Q(2) structure function F-2 in neutrino scattering SO PHYSICAL REVIEW LETTERS LA English DT Article ID DEUTERON STRUCTURE FUNCTIONS; FLAVOR STRUCTURE FUNCTIONS; PARTON DISTRIBUTIONS; QCD FORMULATION; GLOBAL ANALYSIS; PROTON; TARGET AB A new structure function analysis of CCFR deep inelastic nu -N and <()over bar>-N scattering data is presented for previously unexplored kinematic regions down to Bjorken x = 0.0045 and Q(2) = 0.3 GeV2. Comparisons to charged lepton scattering data from NMC and E665 experiments are made and the behavior of the structure function F-2(nu) is studied in the limit Q(2) --> 0. C1 Columbia Univ, New York, NY 10027 USA. Fermilab Natl Accelerator Lab, Batavia, IL 60510 USA. Kansas State Univ, Manhattan, KS 66506 USA. Northwestern Univ, Evanston, IL 60208 USA. Univ Oregon, Eugene, OR 97403 USA. Univ Rochester, Rochester, NY 14627 USA. Univ Wisconsin, Madison, WI 53706 USA. Univ Cincinnati, Cincinnati, OH 45221 USA. RP Fleming, BT (reprint author), Columbia Univ, New York, NY 10027 USA. RI Frey, Raymond/E-2830-2016 OI Frey, Raymond/0000-0003-0341-2636 NR 19 TC 26 Z9 27 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 JUN 11 PY 2001 VL 86 IS 24 BP 5430 EP 5433 DI 10.1103/PhysRevLett.86.5430 PG 4 WC Physics, Multidisciplinary SC Physics GA 441PV UT WOS:000169239500006 PM 11415268 ER PT J AU Ko, CM Koch, V Lin, ZW Redlich, K Stephanov, M Wang, XN AF Ko, CM Koch, V Lin, ZW Redlich, K Stephanov, M Wang, XN TI Kinetic equation with exact charge conservation SO PHYSICAL REVIEW LETTERS LA English DT Article ID HEAVY-ION COLLISIONS; NUCLEUS-NUCLEUS COLLISIONS; PLUS PB COLLISIONS; FREEZE-OUT PARAMETERS; QUARK-GLUON PLASMA; INTERNAL SYMMETRY; CHEMICAL EQUILIBRATION; CANONICAL DESCRIPTION; MODEL DESCRIPTION; STRANGENESS AB A kinetic master equation for multiplicity distributions is formulated for charged particles which are created or destroyed only in pairs due to the conservation of their Abelian charge. It allows one to study time evolution of the multiplicity distributions in a relativistic many-body system with arbitrary average particle multiplicities. It is shown to reproduce the equilibrium results for both canonical (rare particles) and grand canonical (abundant particles) systems. For canonical systems, the equilibrium multiplicity is much lower and the relaxation time is much shorter than the naive extrapolation from grand canonical results. Implications for chemical equilibration in heavy-ion collisions are also discussed. C1 Texas A&M Univ, Inst Cyclotron, College Stn, TX 77843 USA. Texas A&M Univ, Dept Phys, College Stn, TX 77843 USA. Lawrence Berkeley Natl Lab, Div Nucl Sci, Berkeley, CA 94720 USA. Univ Wroclaw, Inst Theoret Phys, PL-50204 Wroclaw, Poland. Univ Illinois, Dept Phys, Chicago, IL 60607 USA. Brookhaven Natl Lab, RIKEN, BNL Res Ctr, Upton, NY 11973 USA. RP Ko, CM (reprint author), Texas A&M Univ, Inst Cyclotron, College Stn, TX 77843 USA. OI Wang, Xin-Nian/0000-0002-9734-9967 NR 35 TC 39 Z9 39 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 JUN 11 PY 2001 VL 86 IS 24 BP 5438 EP 5441 DI 10.1103/PhysRevLett.86.5438 PG 4 WC Physics, Multidisciplinary SC Physics GA 441PV UT WOS:000169239500008 PM 11415270 ER PT J AU Voyles, PM Gerbi, JE Treacy, MMJ Gibson, JM Abelson, JR AF Voyles, PM Gerbi, JE Treacy, MMJ Gibson, JM Abelson, JR TI Absence of an abrupt phase change from polycrystalline to amorphous in silicon with deposition temperature SO PHYSICAL REVIEW LETTERS LA English DT Article ID MEDIUM-RANGE ORDER; THERMODYNAMIC CRITERION; FILMS AB Using fluctuation electron microscopy, we have observed an increase in the mesoscopic spatial fluctuations in the diffracted intensity from vapor-deposited silicon thin films as a function of substrate temperature from the amorphous to polycrystalline regimes. We interpret this increase as an increase in paracrystalline medium-range order in the sample. A paracrystal consists: of topologically crystalline grains in a disordered matrix; in this model the increase in ordering is caused by an increase in the grain size or density. Our observations are counter to the previous belief that the amorphous to polycrystalline transition is a discontinuous disorder-order phase transition. C1 Univ Illinois, Dept Phys, Urbana, IL 61801 USA. NEC Res Inst, Princeton, NJ 08540 USA. Univ Illinois, Dept Mat Sci & Engn, Urbana, IL 61801 USA. Univ Illinois, Coordinated Sci Lab, Urbana, IL 61801 USA. Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. RP Voyles, PM (reprint author), Univ Illinois, Dept Phys, 1110 W Green St, Urbana, IL 61801 USA. RI Gibson, Murray/E-5855-2013; OI Gibson, Murray/0000-0002-0807-6224; Voyles, Paul/0000-0001-9438-4284 NR 21 TC 70 Z9 70 U1 2 U2 17 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 JUN 11 PY 2001 VL 86 IS 24 BP 5514 EP 5517 DI 10.1103/PhysRevLett.86.5514 PG 4 WC Physics, Multidisciplinary SC Physics GA 441PV UT WOS:000169239500027 PM 11415289 ER PT J AU Wolverton, C Ozolins, V AF Wolverton, C Ozolins, V TI Entropically favored ordering: The metallurgy of Al2Cu revisited SO PHYSICAL REVIEW LETTERS LA English DT Article ID PSEUDOPOTENTIALS AB The famous sequence of precipitates which form upon heat treating Al-Cu is part of neatly every metallurgical textbook. Numerous precipitation land other) experiments have led to a long-standing belief that the energetic ground start: of Al2Cu is the theta phase. Modern first-principles calculations at T = 0 K surprisingly predict the energy of the observed Al2Cu-theta phase to be higher than that of its metastable counterpart, theta '. We show that vibrational entropy reverses this energetic preference at T similar to 150-200 degreesC, resolves the apparent discrepancy between theory and experiment, and hence plays a critical (but previously unsuspected) role in the precipitation sequence. C1 Ford Res Lab, Dearborn, MI 48121 USA. Sandia Natl Labs, Livermore, CA 94551 USA. RP Wolverton, C (reprint author), Ford Res Lab, MD3028-SRL, Dearborn, MI 48121 USA. RI Wolverton, Christopher/B-7542-2009; Ozolins, Vidvuds/D-4578-2009 NR 19 TC 109 Z9 111 U1 7 U2 40 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 JUN 11 PY 2001 VL 86 IS 24 BP 5518 EP 5521 DI 10.1103/PhysRevLett.86.5518 PG 4 WC Physics, Multidisciplinary SC Physics GA 441PV UT WOS:000169239500028 PM 11415290 ER PT J AU Hoyt, JJ Asta, M Karma, A AF Hoyt, JJ Asta, M Karma, A TI Method for computing the anisotropy of the solid-liquid interfacial free energy SO PHYSICAL REVIEW LETTERS LA English DT Article ID DENSITY-FUNCTIONAL THEORY; EMBEDDED-ATOM-METHOD; MOLECULAR-DYNAMICS; DENDRITIC GROWTH; SOLIDIFICATION; SURFACE; METALS AB We present a method to compute accurately the weak anisotropy of the solid-liquid intel facial free energy, a parameter which influences dendritic evolution in materials with atomically rough interfaces. The method is based on monitoring interfacial fluctuations during molecular dynamics simulation and extracting the interfacial stiffness which is an order of magnitude more anisotropic than the inter racial free energy. We present results for pure Ni with interatomic potentials derived from the embedded atom method. C1 Sandia Natl Labs, Livermore, CA 94550 USA. Northwestern Univ, Dept Mat Sci & Engn, Evanston, IL 60208 USA. Northeastern Univ, Dept Phys, Boston, MA 02115 USA. RP Hoyt, JJ (reprint author), Sandia Natl Labs, MS 9161,POB 969, Livermore, CA 94550 USA. NR 24 TC 262 Z9 263 U1 13 U2 91 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 JUN 11 PY 2001 VL 86 IS 24 BP 5530 EP 5533 DI 10.1103/PhysRevLett.86.5530 PG 4 WC Physics, Multidisciplinary SC Physics GA 441PV UT WOS:000169239500031 PM 11415293 ER PT J AU Feng, DL Armitage, NP Lu, DH Damascelli, A Hu, JP Bogdanov, P Lanzara, A Ronning, F Shen, KM Eisaki, H Kim, C Shen, ZX Shimoyama, JI Kishio, K AF Feng, DL Armitage, NP Lu, DH Damascelli, A Hu, JP Bogdanov, P Lanzara, A Ronning, F Shen, KM Eisaki, H Kim, C Shen, ZX Shimoyama, JI Kishio, K TI Bilayer splitting in the electronic structure of heavily overdoped Bi2Sr2CaCu2O8+delta SO PHYSICAL REVIEW LETTERS LA English DT Article ID HIGH-TEMPERATURE SUPERCONDUCTORS; FERMI-SURFACE; TRANSITION AB The electronic structure of heavily overdoped Bi2Sr2CaCu2O8+delta is investigated by angle-resolved photoemission spectroscopy. The long-sought bilayer band splitting in this two-plane system is observed in both normal and superconducting states, which qualitatively agrees with the bilayer Hubbard model calculations. The maximum bilayer energy splitting is about 88 meV for the normal state feature, while it is only about 20 meV for the superconducting peak. C1 Stanford Univ, Dept Phys, Stanford, CA 94305 USA. Stanford Univ, Stanford Synchrotron Radiat Lab, Stanford, CA 94305 USA. Univ Tokyo, Dept Appl Chem, Tokyo 1138656, Japan. RP Feng, DL (reprint author), Stanford Univ, Dept Phys, Stanford, CA 94305 USA. RI Shen, Kyle/B-3693-2008; damascelli, andrea/P-6329-2014; Hu, Jiangping/A-9154-2010 OI damascelli, andrea/0000-0001-9895-2226; Hu, Jiangping/0000-0003-4480-1734 NR 17 TC 183 Z9 185 U1 4 U2 21 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 JUN 11 PY 2001 VL 86 IS 24 BP 5550 EP 5553 DI 10.1103/PhysRevLett.86.5550 PG 4 WC Physics, Multidisciplinary SC Physics GA 441PV UT WOS:000169239500036 PM 11415298 ER PT J AU Zhou, XJ Yoshida, T Kellar, SA Bogdanov, PV Lu, ED Lanzara, A Nakamura, M Noda, T Kakeshita, T Eisaki, H Uchida, S Fujimora, A Hussain, Z Shen, ZX AF Zhou, XJ Yoshida, T Kellar, SA Bogdanov, PV Lu, ED Lanzara, A Nakamura, M Noda, T Kakeshita, T Eisaki, H Uchida, S Fujimora, A Hussain, Z Shen, ZX TI Dual nature of the electronic structure of (La2-x-yNdySrx)CuO4 and La1.85Sr0.15CuO4 SO PHYSICAL REVIEW LETTERS LA English DT Article ID FERMI-SURFACE; TRANSITION TEMPERATURE; OXIDE SUPERCONDUCTORS; SPIN FLUCTUATIONS; STRIPE ORDER; LA2-XSRXCUO4; PHASE AB High resolution angle-resolved photoemission measurements have been carried out on (La1.4-x-Nd0.6Srx)CuO4, a model system with static one-dimensional (1D) charge ordering (stripe), and (La-1.85-Sr-0.15)CuO4, a high temperature superconductor(T-c = 40 K) with possible dynamic stripes. In addition to the straight segments near (pi, 0) and (0, pi) antinodal regions, we have identified the existence of spectral weight along the [1, 1] nodal direction in the electronic structure of both systems. This observation of nodal state, together with the straight segments near antinodal regions, reveals the dual nature of the electronic structure of stripes due to the competition of order and disorder. C1 Stanford Univ, Dept Phys, Stanford, CA 94305 USA. Stanford Univ, Stanford Synchrotron Radiat Lab, Stanford, CA 94305 USA. Lawrence Berkeley Natl Lab, Adv Light Source, Berkeley, CA 94720 USA. Univ Tokyo, Dept Phys, Bunkyo Ku, Tokyo 113, Japan. Univ Tokyo, Dept Superconduct, Bunkyo Ku, Tokyo 113, Japan. RP Zhou, XJ (reprint author), Stanford Univ, Dept Phys, Stanford, CA 94305 USA. NR 29 TC 83 Z9 85 U1 3 U2 11 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 JUN 11 PY 2001 VL 86 IS 24 BP 5578 EP 5581 DI 10.1103/PhysRevLett.86.5578 PG 4 WC Physics, Multidisciplinary SC Physics GA 441PV UT WOS:000169239500043 PM 11415305 ER PT J AU Butov, LV Ivanov, AL Imamoglu, A Littlewood, PB Shashkin, AA Dolgopolov, VT Campman, KL Gossard, AC AF Butov, LV Ivanov, AL Imamoglu, A Littlewood, PB Shashkin, AA Dolgopolov, VT Campman, KL Gossard, AC TI Stimulated scattering of indirect excitons in coupled quantum wells: Signature of a degenerate Bose-gas of excitons SO PHYSICAL REVIEW LETTERS LA English DT Article ID CONDENSATION; KINETICS; CU2O AB We observe and analyze strongly nonlinear photoluminescence kinetics of indirect excitons in GaAs/AlGaAs coupled quantum wells at low bath temperatures, greater than or equal to 50 mK. The long recombination lifetime of indirect excitons promotes accumulation of these Bose particles in the lowest energy states and allows the photoexcited excitons to cool down to temperatures when the: dilute 2D gas of indirect excitons becomes statistically degenerate. Our main result-a strong enhancement of the exciton scattering rate to the low-energy states with increasing concentration of the indirect excitons-reveals bosonic stimulation of exciton scattering, which is a signature of a degenerate Bose-gas of excitons. C1 Russian Acad Sci, Inst Solid State Phys, Chernogolovka 142432, Russia. Univ Wales Coll Cardiff, Dept Phys & Astron, Cardiff CF24 3YB, S Glam, Wales. Univ Calif Santa Barbara, Dept Elect & Comp Engn, Santa Barbara, CA 93106 USA. Univ Cambridge, Cavendish Lab, Dept Phys, TCM, Cambridge CB3 0HE, England. Bell Labs, Lucent Technol, Murray Hill, NJ 07974 USA. RP Butov, LV (reprint author), Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. RI Cavendish, TCM/C-9489-2009; Littlewood, Peter/B-7746-2008 NR 14 TC 130 Z9 133 U1 1 U2 20 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 JUN 11 PY 2001 VL 86 IS 24 BP 5608 EP 5611 DI 10.1103/PhysRevLett.86.5608 PG 4 WC Physics, Multidisciplinary SC Physics GA 441PV UT WOS:000169239500051 PM 11415313 ER PT J AU Hunt, AW Cassidy, DB Sterne, PA Cowan, TE Howell, RH Lynn, KG Golevchenko, JA AF Hunt, AW Cassidy, DB Sterne, PA Cowan, TE Howell, RH Lynn, KG Golevchenko, JA TI Doppler broadening of in-flight positron annihilation radiation due to electron momentum SO PHYSICAL REVIEW LETTERS LA English DT Article ID ALUMINUM AB We report the first observation of electron momentum contributions to the Doppler broadening of radiation produced by in-flight two-photon annihilation in solids. In these experiments an approximately 2.5 MeV positron beam impinged on thin polyethylene, aluminum, and gold targets. Since energetic positrons easily penetrate the nuclear Coulomb potential and do not cause a strong charge polarization. the experimental annihilation line shapes agree well with calculations based on a simple independent particle model. Moreover, annihilations with the deepest cure electrons are greatly enhanced. C1 Washington State Univ, Mat Res Ctr, Pullman, WA 99164 USA. Harvard Univ, Dept Phys, Cambridge, MA 02138 USA. Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. Washington State Univ, Dept Phys, Pullman, WA 99164 USA. RP Cassidy, DB (reprint author), Washington State Univ, Mat Res Ctr, Pullman, WA 99164 USA. RI Cowan, Thomas/A-8713-2011; OI Cowan, Thomas/0000-0002-5845-000X; Cassidy, David/0000-0001-8332-5553 NR 19 TC 7 Z9 7 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 JUN 11 PY 2001 VL 86 IS 24 BP 5612 EP 5615 DI 10.1103/PhysRevLett.86.5612 PG 4 WC Physics, Multidisciplinary SC Physics GA 441PV UT WOS:000169239500052 PM 11415314 ER PT J AU Goldberg, KA Bokor, J AF Goldberg, KA Bokor, J TI Fourier-transform method of phase-shift determination SO APPLIED OPTICS LA English DT Article ID SELF-CALIBRATING ALGORITHM; POINT-DIFFRACTION INTERFEROMETER; FRINGE-PATTERN ANALYSIS; LEAST-SQUARES; ERROR; ACCURACY; DESIGN; OPTICS AB A new phase-shifting interferometry analysis technique has been developed to overcome the errors introduced by nonlinear, irregular, or unknown phase-step increments. In the presence of a spatial carrier frequency, by observation of the phase of the first-order maximum in the Fourier domain, the global phase-step positions can be measured, phase-shifting elements can be calibrated, and the accuracy of phase-shifting analysis can be improved. Furthermore, reliance on the calibration accuracy of transducers used in phase-shifting interferometry can be reduced; and phase-retrieval errors (e.g., fringe print-through) introduced by uncalibrated fluctuations in the phase-shifting phase increments can be alleviated. The method operates deterministically and does not rely on iterative global error minimization. Relative to other techniques, the number of recorded interferograms required for analysis can be reduced. (C) 2001 Optical Society of America. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Ctr Xray Opt, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Elect Engn & Comp Sci, Berkeley, CA 94720 USA. RP Univ Calif Berkeley, Lawrence Berkeley Lab, Ctr Xray Opt, 1 Cyclotron Rd,Mail Stop 2-400, Berkeley, CA 94720 USA. EM kagoldberg@lbl.gov RI Bokor, Jeffrey/A-2683-2011 NR 35 TC 86 Z9 91 U1 2 U2 8 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 JUN 10 PY 2001 VL 40 IS 17 BP 2886 EP 2894 DI 10.1364/AO.40.002886 PG 9 WC Optics SC Optics GA 440KA UT WOS:000169173400010 PM 18357307 ER PT J AU Alcock, C Allsman, RA Alves, DR Axelrod, TS Becker, A Bennett, DP Clayton, GC Cook, KH Dalal, N Drake, AJ Freeman, KC Geha, M Gordon, KD Griest, K Kilkenny, D Lehner, MJ Marshall, SL Minniti, D Misselt, KA Nelson, CA Peterson, BA Popowski, P Pratt, MR Quinn, PJ Stubbs, CW Sutherland, W Tomaney, A Vandehei, T Welch, DL AF Alcock, C Allsman, RA Alves, DR Axelrod, TS Becker, A Bennett, DP Clayton, GC Cook, KH Dalal, N Drake, AJ Freeman, KC Geha, M Gordon, KD Griest, K Kilkenny, D Lehner, MJ Marshall, SL Minniti, D Misselt, KA Nelson, CA Peterson, BA Popowski, P Pratt, MR Quinn, PJ Stubbs, CW Sutherland, W Tomaney, A Vandehei, T Welch, DL CA MACHO Collaboration TI The MACHO project LMC variable star inventory. X. The R Coronae Borealis stars SO ASTROPHYSICAL JOURNAL LA English DT Article DE Magellanic Clouds; stars : evolution; stars : variables : other ID LARGE-MAGELLANIC-CLOUD; DEFICIENT CARBON STARS; INFRARED OBSERVATIONS; SAKURAIS OBJECT; WHITE-DWARFS; RCB STARS; EVOLUTION; DUST; PHOTOMETRY; SUPERGIANTS AB We report the discovery of eight new R Coronae Borealis (RCB) stars in the Large Magellanic Cloud (LMC) using the MACHO project photometry database. The discovery of these new stars increases the number of known RCB stars in the LMC to thirteen. We have also discovered four stars similar to the Galactic variable DY Per. These stars decline much more slowly and are cooler than the RCB stars. The absolute luminosities of the Galactic RCB stars are unknown since there is no direct measurement of the distance to any Galactic RCB star. Hence, the importance of the LMC RCB stars. We find a much larger range of absolute magnitudes (M-V = -2.5 to -5 mag) than inferred from the small pre-MACHO sample of LMC RCB stars. It is likely that there is a temperature-M, relationship with the cooler stars being intrinsically fainter. Cool (similar to 5000 K) RCB stars are much more common than previously thought based on the Galactic RCB star sample. Using the fairly complete sample of RCB stars discovered in the MACHO fields, we have estimated the likely number of RCB stars in the Galaxy to be similar to 3200. The SMC MACHO fields were also searched for RCB stars, but none were found. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. Univ Calif Berkeley, Ctr Particle Astrophys, Berkeley, CA 94720 USA. Australian Natl Univ, Supercomp Facil, Canberra, ACT 0200, Australia. Space Telescope Sci Inst, Baltimore, MD 21218 USA. Res Sch Astron & Astrophys, Weston Creek, ACT 2611, Australia. Univ Washington, Dept Astron, Seattle, WA 98195 USA. Univ Washington, Dept Phys, Seattle, WA 98195 USA. Univ Notre Dame, Dept Phys, Notre Dame, IN 46556 USA. Louisiana State Univ, Dept Phys & Astron, Baton Rouge, LA 70803 USA. Univ Calif San Diego, Dept Phys, San Diego, CA 92093 USA. Univ Arizona, Steward Observ, Tucson, AZ 85721 USA. S African Astron Observ, ZA-7935 Observatory, South Africa. Univ Sheffield, Dept Phys, Sheffield S3 7RH, S Yorkshire, England. Pontificia Univ Catolica Chile, Dept Astron, Santiago 22, Chile. NASA, Infrared Astrophys Branch, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. European So Observ, D-85748 Garching, Germany. Univ Oxford, Dept Phys, Oxford OX1 3RH, England. McMaster Univ, Hamilton, ON L8S 4M1, Canada. RP Alcock, C (reprint author), Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RI Stubbs, Christopher/C-2829-2012; Quinn, Peter/B-3638-2013; OI Stubbs, Christopher/0000-0003-0347-1724; Lehner, Matthew/0000-0003-4077-0985 NR 81 TC 65 Z9 65 U1 0 U2 2 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD JUN 10 PY 2001 VL 554 IS 1 BP 298 EP 315 DI 10.1086/321369 PN 1 PG 18 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 449MV UT WOS:000169690800028 ER PT J AU Diwan, MV Ma, H AF Diwan, MV Ma, H TI Tests of the standard model using muon polarization asymmetries in kaon decays SO INTERNATIONAL JOURNAL OF MODERN PHYSICS A LA English DT Review ID DIRECT CP VIOLATION; CHIRAL PERTURBATION-THEORY; ELECTRIC-DIPOLE MOMENT; 2 HIGGS DOUBLETS; RARE K-DECAYS; BRANCHING RATIO; K-MU-3 DECAYS; T-VIOLATION; SEMILEPTONIC DECAYS; EXPERIMENTAL LIMIT AB We have examined the physics and the experimental feasibility of studying various kaon decay processes in which the polarization of a muon in the final state is measured. Valuable information on CP violation, the quark mixing (CKM) matrix, and new physics can be obtained from such measurements. We have considered muon polarization in K-L --> mu (+)mu (-) and K --> pi mu (+)mu (-) decays. Although the effects are small, or difficult to measure because of the small branching ratios involved, these studies could provide clean measurements of the CKM parameters. The experimental difficulty appears comparable to the observation of K --> piv (v) over bar. New sources of physics, involving nonstandard CP violation, could produce effects observable in these measurements. Limits from new results on the neutron and electron electric dipole moment, and (epsilon')/(epsilon) in neutral kaon decays, do not eliminate certain models that could contribute to the signal. A detailed examination of muon polarization out of the decay plane in K+ --> mu (+)pi (0)v and K+ --> mu + v gamma decays also appears to be of interest. With current kaon beams and detector techniques, it is possible to measure the T-violating polarization for K+ --> mu (+)pi (0)v with uncertainties approaching similar to 10(-4). This level of sensitivity would provide an interesting probe of new physics. C1 Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. RP Diwan, MV (reprint author), Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. NR 102 TC 8 Z9 8 U1 0 U2 0 PU WORLD SCIENTIFIC PUBL CO PTE LTD PI SINGAPORE PA JOURNAL DEPT PO BOX 128 FARRER ROAD, SINGAPORE 912805, SINGAPORE SN 0217-751X J9 INT J MOD PHYS A JI Int. J. Mod. Phys. A PD JUN 10 PY 2001 VL 16 IS 14 BP 2449 EP 2471 DI 10.1142/S0217751X01003330 PG 23 WC Physics, Nuclear; Physics, Particles & Fields SC Physics GA 447BW UT WOS:000169549500001 ER PT J AU Hunke, EC AF Hunke, EC TI Viscous-plastic sea ice dynamics with the EVP model: Linearization issues SO JOURNAL OF COMPUTATIONAL PHYSICS LA English DT Article DE sea ice; visco-plasticity; constitutive equations; numerical simulation methods ID NUMERICAL-SIMULATION; WEDDELL SEA; PACK ICE; VARIABILITY; OCEAN AB Behavior of the elastic-viscous-plastic (EVP) model for sea ice dynamics is explored, with particular attention to a necessary numerical Linearization of the internal ice stress term in the momentum equation. Improvements to both the mathematical and numerical formulations of the model have moderated the impact of linearizing the stress term; simulations with the original EVP formulation and the improved version are used to explain the consequences of using different numerical approaches. In particular,, we discuss the model behavior in two regimes, low ice concentration such as occurs in the marginal ice zone, and very high ice concentration, where the ice is nearly rigid. Most of these results are highly relevant to the viscous-plastic (VP) ice dynamics model on which the EVP model is based. We provide examples of certain pathologies that the VP model and its numerical formulations exhibit at steady state. (C) 2001 Academic Press. C1 Los Alamos Natl Lab, Div Theoret, Grp Fluid Dynam T 3, Los Alamos, NM 87545 USA. RP Hunke, EC (reprint author), Los Alamos Natl Lab, Div Theoret, Grp Fluid Dynam T 3, Los Alamos, NM 87545 USA. EM eclare@lanl.gov NR 18 TC 80 Z9 83 U1 0 U2 8 PU ACADEMIC PRESS INC ELSEVIER SCIENCE PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0021-9991 J9 J COMPUT PHYS JI J. Comput. Phys. PD JUN 10 PY 2001 VL 170 IS 1 BP 18 EP 38 DI 10.1006/jcph.2001.6710 PG 21 WC Computer Science, Interdisciplinary Applications; Physics, Mathematical SC Computer Science; Physics GA 453YT UT WOS:000169946300002 ER PT J AU Shestakov, AI Milovich, JL Prasad, MK AF Shestakov, AI Milovich, JL Prasad, MK TI Combining cell- and point-centered methods in 3D, unstructured-grid radiation-hydrodynamic codes SO JOURNAL OF COMPUTATIONAL PHYSICS LA English DT Article ID DIFFUSION; SCHEME AB We describe the coupling of a cell-centered hydrodynamic scheme to a point-centered finite element method simulating diffusive processes such as heat conduction and radiation transport. We also discuss procedures that compute the material coefficients, the scheme advancing the radiation energy, and how to tally diffusion boundary fluxes in sections with Dirichlet boundary data. To demonstrate the coupling's robustness and accuracy, we simulate the implosion of a radiatively driven inertial confinement fusion capsule. The simulation, done on an unstructured, 3D, tetrahedral grid, maintains spherical symmetry. (C) 2001 Academic Press. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Shestakov, AI (reprint author), Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. NR 27 TC 7 Z9 7 U1 0 U2 1 PU ACADEMIC PRESS INC PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0021-9991 J9 J COMPUT PHYS JI J. Comput. Phys. PD JUN 10 PY 2001 VL 170 IS 1 BP 81 EP 111 DI 10.1006/jcph.2001.6723 PG 31 WC Computer Science, Interdisciplinary Applications; Physics, Mathematical SC Computer Science; Physics GA 453YT UT WOS:000169946300004 ER PT J AU Morel, JE Hall, ML Shashkov, MJ AF Morel, JE Hall, ML Shashkov, MJ TI A local support-operators diffusion discretization scheme for hexahedral meshes SO JOURNAL OF COMPUTATIONAL PHYSICS LA English DT Article DE diffusion; support-operators method; unstructured mesh ID COEFFICIENTS AB We derive a cell-centered 3-D diffusion differencing scheme for unstructured hexahedral meshes using the local support-operators method. Our method is said to be local because it yields a sparse matrix representation for the diffusion equation, whereas the traditional support-operators method yields a dense matrix representation. The diffusion discretization scheme that we have developed offers several advantages relative to existing schemes. Most importantly, it offers second-order accuracy on reasonably well-behaved nonsmooth meshes, rigorously treats material discontinuities, and has a symmetric positive-definite coefficient matrix. The order of accuracy is demonstrated computationally rather than theoretically. Rigorous treatment of material discontinuities implies that the normal component of the flux is continuous across such discontinuities while the parallel components may be either continuous or discontinuous in accordance with the exact solution to the problem being considered, The only disadvantage of the method is that it has both cell-centered and face-centered scalar unknowns as opposed to just cell-center scalar unknowns. Computational examples are given which demonstrate the accuracy and cost of the new scheme. (C) 2001 Academic Press. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Morel, JE (reprint author), Univ Calif Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. NR 15 TC 18 Z9 18 U1 0 U2 1 PU ACADEMIC PRESS INC PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0021-9991 J9 J COMPUT PHYS JI J. Comput. Phys. PD JUN 10 PY 2001 VL 170 IS 1 BP 338 EP 372 DI 10.1006/jcph.2001.6736 PG 35 WC Computer Science, Interdisciplinary Applications; Physics, Mathematical SC Computer Science; Physics GA 453YT UT WOS:000169946300015 ER PT J AU Durham, WB Stern, LA Kirby, SH AF Durham, WB Stern, LA Kirby, SH TI Rheology of ice I at low stress and elevated confining pressure SO JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH LA English DT Article ID GRAIN-GROWTH; SUPERPLASTICITY; RECRYSTALLIZATION; CAVITATION; SHEET; CREEP; WATER; SHELL; SIZE AB Triaxial compression testing of pure, polycrystalline water ice I at conditions relevant to planetary interiors and near-surface environments (differential stresses 0.45 to 10 MPa, temperatures 200 to 250 K, confining pressure 50 MPa) reveals that a complex variety of theologies and grain structures may exist for ice and that theology of ice appears to depend strongly on the grain structures. The creep of polycrystalline ice I with average grain size of 0.25 mm and larger is consistent with previously published dislocation creep laws, which are now extended to strain rates as low as 2 x 10(-8) s(-1) When ice I is reduced to very fine and uniform grain size by rapid pressure release from the ice II stability field, the theology changes dramatically. At 200 and 220 K the theology matches the grain-size-sensitive theology measured by Goldsby and Kohlstedt [1997, this issue] at 1 atm. This finding dispels concerns that the Goldsby and Kohlstedt results were influenced by mechanisms such as microfracturing and cavitation, processes not expected to operate at elevated pressures in planetary interiors. At 233 K and above, grain growth causes the fine-grained ice to become more creep resistant. Scanning electron microscopy investigation of some of these deformed samples shows that grains have markedly coarsened and the strain hardening can be modeled by normal grain growth and the Goldsby and Kohlstedt theology. Several samples also displayed very heterogeneous grain sizes and high aspect ratio grain shapes. Grain-size-sensitive creep and dislocation creep coincidentally contribute roughly equal amounts of strain rate at conditions of stress, temperature, and grain size that are typical of terrestrial and planetary settings, so modeling ice dynamics in these settings must include both mechanisms. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. US Geol Survey, Menlo Park, CA 94025 USA. RP Durham, WB (reprint author), Univ Calif Lawrence Livermore Natl Lab, POB 808,L-201, Livermore, CA 94550 USA. EM durham1@llnl.gov; lstern@usgs.gov; skirby@usgs.gov NR 26 TC 42 Z9 42 U1 0 U2 6 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-9313 EI 2169-9356 J9 J GEOPHYS RES-SOL EA JI J. Geophys. Res.-Solid Earth PD JUN 10 PY 2001 VL 106 IS B6 BP 11031 EP 11042 DI 10.1029/2000JB900446 PG 12 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 440DG UT WOS:000169160200008 ER PT J AU Salmonson, JD Wilson, JR Mathews, GJ AF Salmonson, JD Wilson, JR Mathews, GJ TI Gamma-ray bursts via the neutrino emission from heated neutron stars SO ASTROPHYSICAL JOURNAL LA English DT Article DE binaries : close; gamma rays : bursts; gamma rays : theory; stars : neutron ID QUASI-PERIODIC OSCILLATIONS; PAIR-ELECTROMAGNETIC PULSE; BLACK-HOLES; RX J0720.4-3125; BOUNDARY-LAYER; BINARIES; MODEL; EQUATION; MATTER; STATE AB A model is proposed for gamma-ray bursts based upon a neutrino burst of similar to 10(52) ergs lasting a few seconds above a heated collapsing neutron star. This type of thermal neutrino burst is suggested by relativistic hydrodynamic studies of the compression, heating, and collapse of close binary neutron stars as they approach their last stable orbit but may arise from other sources as well. We present a spherically symmetric hydrodynamic simulation of the formation and evolution of the pair plasma associated with such a neutrino burst. This pair plasma leads to the production of similar to 10(51)-10(52) ergs in gamma rays with spectral and temporal properties consistent with many observed gamma-ray bursts. C1 Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. Univ Notre Dame, Dept Phys, Notre Dame, IN 46556 USA. RP Salmonson, JD (reprint author), Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. NR 63 TC 18 Z9 18 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD JUN 8 PY 2001 VL 553 IS 2 BP 471 EP 487 DI 10.1086/320938 PN 1 PG 17 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 444YX UT WOS:000169429100001 ER PT J AU Haiman, Z Mohr, JJ Holder, GP AF Haiman, Z Mohr, JJ Holder, GP TI Constraints on cosmological parameters from future galaxy cluster surveys SO ASTROPHYSICAL JOURNAL LA English DT Article DE cosmology : observations; cosmology : theory; galaxies : clusters : general ID X-RAY-CLUSTERS; IA SUPERNOVAE; MODELS; ENERGY; SIMULATIONS; ABUNDANCE; UNIVERSE; CONSTANT; DENSITY; OMEGA AB We study the expected redshift evolution of galaxy cluster abundance between in different 0 less than or similar to z less than or similar to 3 cosmologies, including the effects of the cosmic equation of state parameter w = p/rho. Using the halo mass function obtained in recent large-scale numerical simulations, we model the expected cluster yields in a 12 deg(2) Sunyaev-Zeldovich effect (SZE) survey and a deep 10(4) deg(2) X-ray survey over a wide range of cosmological parameters. We quantify the statistical differences among cosmologies using both the total number and redshift distribution of clusters. Provided that the local cluster abundance is known to a few percent accuracy, we find only mild degeneracies between w and either Omega (m) or h. As a result, both surveys will provide improved constraints on Omega (m) and w. The Omega (m)-w degeneracy from both surveys is complementary to those found either in studies of cosmic microwave background (CMB) anisotropies or of high-redshift supernovae (SNe). As a result, combining these surveys together with either CMB or SNe studies can reduce the statistical uncertainty on both w and Omega (m) to levels below what could be obtained by combining only the latter two data sets. Our results indicate a formal statistical uncertainty of approximate to3% (68% confidence) on both Omega (m) and w when the SZE survey is combined with either the CMB or SN data; the large number of clusters in the X-ray survey further suppresses the degeneracy between w and both and h. Systematics and internal evolution of cluster structure at the present pose uncertainties above these levels. We briefly discuss and quantify the relevant systematic errors. By focusing on clusters with measured temperatures in the X-ray survey, we reduce our sensitivity to systematics such as nonstandard evolution of internal cluster structure. C1 Princeton Univ Observ, Princeton, NJ 08544 USA. Fermilab Natl Accelerator Lab, NASA Fermilab Astrophys Ctr, Batavia, IL 60510 USA. Univ Illinois, Dept Astron, Urbana, IL 61801 USA. Univ Illinois, Dept Phys, Urbana, IL 61801 USA. Univ Chicago, Dept Astron & Astrophys, Chicago, IL 60637 USA. RP Princeton Univ Observ, Peyton Hall, Princeton, NJ 08544 USA. EM zoltan@astro.princeton.edu; mohr@oddjob.uchicago.edu NR 50 TC 332 Z9 333 U1 0 U2 1 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0004-637X EI 1538-4357 J9 ASTROPHYS J JI Astrophys. J. PD JUN 8 PY 2001 VL 553 IS 2 BP 545 EP 561 DI 10.1086/320939 PN 1 PG 17 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 444YX UT WOS:000169429100007 ER PT J AU Hartman, RC Bottcher, M Aldering, G Aller, H Aller, M Backman, DE Balonek, TJ Bertsch, DL Bloom, SD Bock, H Boltwood, P Carini, MT Collmar, W De Francesco, G Ferrara, EC Freudling, W Gear, WK Hall, PB Heidt, J Hughes, P Hunter, SD Jogee, S Johnson, WN Kanbach, G Katajainen, S Kidger, M Kii, T Koskimies, M Kraus, A Kubo, H Kurtanidze, O Lanteri, L Lawson, A Lin, YC Lisenfeld, U Madejski, G Makino, F Maraschi, L Marscher, AP McFarland, JP McHardy, I Miller, HR Nikolashvili, M Nilsson, K Noble, JC Nucciarelli, G Ostorero, L Pian, E Pursimo, T Raiteri, CM Reich, W Rekola, R Richter, GM Robson, EI Sadun, A Savolainen, T Sillanpaa, A Smale, A Sobrito, G Sreekumar, P Stevens, JA Takalo, LO Tavecchio, F Terasranta, H Thompson, DJ Tornikoski, M Tosti, G Ungerechts, H Urry, CM Valtaoja, E Villata, M Wagner, SJ Wehrle, AE Wilson, JW AF Hartman, RC Bottcher, M Aldering, G Aller, H Aller, M Backman, DE Balonek, TJ Bertsch, DL Bloom, SD Bock, H Boltwood, P Carini, MT Collmar, W De Francesco, G Ferrara, EC Freudling, W Gear, WK Hall, PB Heidt, J Hughes, P Hunter, SD Jogee, S Johnson, WN Kanbach, G Katajainen, S Kidger, M Kii, T Koskimies, M Kraus, A Kubo, H Kurtanidze, O Lanteri, L Lawson, A Lin, YC Lisenfeld, U Madejski, G Makino, F Maraschi, L Marscher, AP McFarland, JP McHardy, I Miller, HR Nikolashvili, M Nilsson, K Noble, JC Nucciarelli, G Ostorero, L Pian, E Pursimo, T Raiteri, CM Reich, W Rekola, R Richter, GM Robson, EI Sadun, A Savolainen, T Sillanpaa, A Smale, A Sobrito, G Sreekumar, P Stevens, JA Takalo, LO Tavecchio, F Terasranta, H Thompson, DJ Tornikoski, M Tosti, G Ungerechts, H Urry, CM Valtaoja, E Villata, M Wagner, SJ Wehrle, AE Wilson, JW TI Multiepoch multiwavelength spectra and models for blazar 3C 279 SO ASTROPHYSICAL JOURNAL LA English DT Article DE gamma rays : observations; quasars : individual (3C 279) ID EXTRAGALACTIC RADIO-SOURCES; RAY ASTRONOMY SATELLITE; MILLIMETER CONTINUUM MEASUREMENTS; ENERGY CONCENTRATOR SPECTROMETER; ACTIVE GALACTIC NUCLEI; BL LACERTAE OBJECTS; 3C 279; GAMMA-RAYS; QUASAR 3C-279; INSTRUMENT DESCRIPTION AB Of the blazars detected by EGRET in GeV gamma -rays, 3C 279 is not only the best observed by EGRET but also one of the best monitored at lower frequencies. We have assembled 11 spectra, from GHz radio through GeV gamma -rays, from the time intervals of EGRET observations. Although some of the data have appeared in previous publications, most are new, including data taken during the high states in early 1999 and early 2000. All of the spectra show substantial gamma -ray contribution to the total luminosity of the object; in a high state, the gamma -ray luminosity dominates over that at all other frequencies by a factor of more than 10. There is no clear pattern of time correlation; different bands do not always rise and fall together, even in the optical, X-ray, and gamma -ray bands. The spectra are modeled using a leptonic jet, with combined synchrotron self-Compton plus external Compton gamma -ray production. Spectral variability of 3C 279 is consistent with variations of the bulk Lorentz factor of the jet, accompanied by changes in the spectral shape of the electron distribution. Our modeling results are consistent with the UV spectrum of 3C 279 being dominated by accretion disk radiation during times of low gamma -ray intensity. C1 NASA, Goddard Space Flight Ctr, High Energy Astrophys Lab, Greenbelt, MD 20771 USA. Rice Univ, Dept Space Phys & Astron, Houston, TX 77005 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. Univ Michigan, Dept Astron, Ann Arbor, MI 48109 USA. Franklin & Marshall Coll, Dept Phys & Astron, Lancaster, PA 17604 USA. Colgate Univ, Dept Phys & Astron, Hamilton, NY 13346 USA. Hampden Sydney Coll, Hampden Sydney, VA 23943 USA. Landessternwarte Konigstuhl, D-69117 Heidelberg, Germany. Western Kentucky Univ, Dept Phys & Astron, Bowling Green, KY 42104 USA. Max Planck Inst Extraterr Phys, D-85740 Garching, Germany. Osserv Astron Torino, I-10025 Pino Torinese, Italy. Georgia State Univ, Dept Phys & Astron, Atlanta, GA 30303 USA. European So Observ, D-85748 Munich, Germany. Space Telescope European Coordinating Facil, D-85748 Munich, Germany. Cardiff Univ, Dept Phys & Astron, Cardiff CF2 3YB, S Glam, Wales. Pontificia Univ Catolica Chile, Fac Fis, Dept Astron & Astrofis, Santiago 22, Chile. Princeton Univ Observ, Princeton, NJ 08544 USA. CALTECH, Div Phys Math & Astron, Pasadena, CA 91125 USA. USN, Res Lab, Washington, DC 20375 USA. Tuorla Observ, FIN-21500 Piikkio, Finland. Inst Astrofis Canarias, E-38200 San Cristobal la Laguna, Tenerife, Spain. Inst Space & Astronaut Sci, Kanagawa 2298510, Japan. Max Planck Inst Radioastron, D-53121 Bonn, Germany. Kyoto Univ, Fac Sci, Dept Phys, Kyoto 6068502, Japan. Astrophys Inst Potsdam, D-14482 Potsdam, Germany. Univ Southampton, Dept Phys & Astron, Southampton SO17 1BJ, Hants, England. Stanford Univ, WW Hansen Expt Phys Lab, Stanford, CA 94305 USA. Inst Radioastron Millimetr, E-18012 Granada, Spain. Stanford Linear Accelerator Ctr, GLAST Grp, Menlo Pk, CA 94025 USA. Osserv Astron Brera, I-20121 Milan, Italy. Boston Univ, Inst Astrophys Res, Boston, MA 02215 USA. Abastumani Observ, GE-383762 Abastumani, Rep of Georgia. Osservatorio Astron Perugia, I-06123 Perugia, Italy. Astron Observ Trieste, I-34131 Trieste, Italy. Joint Astron Ctr, Hilo, HI 96720 USA. Univ Cent Lancashire, Ctr Astrophys, Preston PR1 2HE, Lancs, England. Univ Colorado, Dept Phys, Denver, CO 80217 USA. NASA, Goddard Space Flight Ctr, High Energy Astrophys Lab, Greenbelt, MD 20771 USA. Indian Space Res Org, Satellite Ctr, Control & Mission Area, Bangalore 560017, Karnataka, India. UCL, Mullard Space Sci Lab, Dorking RH5 6NT, Surrey, England. Aalto Univ, Metsahovi Radio Observ, Kylmala 02540, Finland. Space Telescope Sci Inst, Baltimore, MD 21218 USA. Univ Turku, Dept Phys, SF-20500 Turku, Finland. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP NASA, Goddard Space Flight Ctr, High Energy Astrophys Lab, Code 661, Greenbelt, MD 20771 USA. EM rch@egret.gsfc.nasa.gov RI Hunter, Stanley/D-2942-2012; Thompson, David/D-2939-2012; Tosti, Gino/E-9976-2013; Urry, Claudia/G-7381-2011; Johnson, Neil/G-3309-2014; Kurtanidze, Omar/J-6237-2014; Lisenfeld, Ute/A-1637-2015; OI Thompson, David/0000-0001-5217-9135; Urry, Claudia/0000-0002-0745-9792; Lisenfeld, Ute/0000-0002-9471-5423; Ostorero, Luisa/0000-0003-3983-5980 NR 79 TC 112 Z9 114 U1 0 U2 4 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0004-637X EI 1538-4357 J9 ASTROPHYS J JI Astrophys. J. PD JUN 8 PY 2001 VL 553 IS 2 BP 683 EP 694 DI 10.1086/320970 PN 1 PG 12 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 444YX UT WOS:000169429100019 ER PT J AU Aerts, C Kaye, AB AF Aerts, C Kaye, AB TI A spectroscopic analysis of the gamma Doradus star HD 207223=HR 8330 SO ASTROPHYSICAL JOURNAL LA English DT Article DE stars : individual (HD 207223, gamma Doradus); stars : oscillations; stars : variables : other ID LINE-PROFILE VARIATIONS; PULSATING B-STARS; MODE-IDENTIFICATION; MOMENT METHOD; VARIABLES AB We present a detailed analysis of 76 high-resolution, high signal-to-noise spectra of the gamma Doradus star HD 207223 = HR 8330. Periodogram analysis of the moments of the line profiles reveals a single period of 2.67 +/- 0.01 days, a result consistent with that found in photometric studies. Mode identification was accomplished with both the moment method and from direct line-profile fitting. Both methods clearly point towards a sectoral mode of degree l greater than or equal to 2. The inclusion of rotational effects, by taking the Coriolis force into account, reveals a single consistent solution : an l = m = +2 retrograde sectoral mode that has a period of 1.4 days in the corotating frame. The star is seen at an inclination of 30 degrees. From this, we derive a rotational period of 4.9 days. C1 Inst Sterrenkunde, B-3001 Louvain, Belgium. Univ Calif Los Alamos Natl Lab, Div Appl Phys, Los Alamos, NM 87545 USA. RP Aerts, C (reprint author), Inst Sterrenkunde, Celestijnenlaan 200, B-3001 Louvain, Belgium. NR 22 TC 16 Z9 16 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD JUN 8 PY 2001 VL 553 IS 2 BP 814 EP 822 DI 10.1086/320973 PN 1 PG 9 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 444YX UT WOS:000169429100032 ER PT J AU Tzeli, D Mavridis, A Xantheas, SS AF Tzeli, D Mavridis, A Xantheas, SS TI A molecular level study of the aqueous microsolvation of acetylene SO CHEMICAL PHYSICS LETTERS LA English DT Article ID WATER CLUSTERS (H2O)(N); AB-INITIO; INTERACTION ENERGY; WAVE-FUNCTIONS; BASIS-SETS; HYDROGEN; SPECTROSCOPY; COMPLEXES; SYSTEMS; RELAXATION AB We present an analysis of the structural, energetic and spectral features associated with the different hydrogen bonded networks found in the first few acetylene-water clusters AW(n) (n = 1-4) from first principles calculations. Contrary to the predictions of an empirical interaction potential, acetylene is incorporated into a hydrogen bonded ring when it clusters with two or three water molecules. This structural pattern changes for n = 4 with the formation of a water tetramer interacting with acetylene. This structural transition from n = 3 to 4 is spectroscopically manifested by a qualitative change in the appearance of the infrared spectra of the corresponding global minima. (C) 2001 Published by Elsevier Science B.V. C1 Pacific NW Natl Lab, Environm Mol Sci Lab, Richland, WA 99352 USA. Natl & Kapodistrian Univ Athens, Chem Phys Lab, Dept Chem, Athens 15710, Greece. RP Xantheas, SS (reprint author), Pacific NW Natl Lab, Environm Mol Sci Lab, 906 Battelle Blvd,POB 999,MS K8-91, Richland, WA 99352 USA. RI Xantheas, Sotiris/L-1239-2015; OI Xantheas, Sotiris/0000-0002-6303-1037 NR 34 TC 20 Z9 20 U1 0 U2 4 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0009-2614 J9 CHEM PHYS LETT JI Chem. Phys. Lett. PD JUN 8 PY 2001 VL 340 IS 5-6 BP 538 EP 546 DI 10.1016/S0009-2614(01)00444-4 PG 9 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 443ZQ UT WOS:000169373800022 ER PT J AU Lee, YC Kolafa, J Curtiss, LA Ratner, MA Shriver, DF AF Lee, YC Kolafa, J Curtiss, LA Ratner, MA Shriver, DF TI Molten salt electrolytes. I. Experimental and theoretical studies of LiI/AlCl3 SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID MOLECULAR-ORBITAL CALCULATIONS; LITHIUM IODIDE; IONIC MODEL; DYNAMICS; SYSTEMS; ALCL3; ELECTRODEPOSITION; CHLORIDE; HALIDES; WATER AB Molten LiI/AlCl3 with different molar ratios of LiI to AlCl3 were prepared and characterized by Raman spectroscopy, thermal analysis, and impedance measurements. The LiI/AlCl3 adducts melt at 70-80 degreesC and the Raman spectrum indicates that a variety of haloaluminates exist in the system. The 1:1 adduct has the highest ionic conductivity, 2x10(-6) S/cm at 25 degreesC, and the conductivity increases dramatically as the temperature is increased. Molecular dynamics (MD) simulations suggest that several haloaluminates are present in the adducts. Ab initio calculations were carried out on the species that were predicted by MD simulations and these results were compared with Raman spectra, and good agreement was obtained. Several-ns-long MD simulations allowed us to study the conductivity and relaxation processes in the 1:1 and 1:2 melts at higher temperatures. (C) 2001 American Institute of Physics. C1 Northwestern Univ, Dept Chem, Evanston, IL 60208 USA. Northwestern Univ, Mat Res Ctr, Evanston, IL 60208 USA. Acad Sci Czech Republ, Inst Chem Proc Fundamentals, E Hala Lab Thermodynam, Prague 16502 6, Czech Republic. Argonne Natl Lab, Div Chem, Argonne, IL 60439 USA. Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. RP Lee, YC (reprint author), Northwestern Univ, Dept Chem, Evanston, IL 60208 USA. RI Kolafa, Jiri/B-7513-2008 NR 44 TC 5 Z9 5 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 JUN 8 PY 2001 VL 114 IS 22 BP 9998 EP 10009 DI 10.1063/1.1372328 PG 12 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 437NP UT WOS:000168998000039 ER PT J AU MacKinnon, JA Eckert, J Coker, DF Bug, ALR AF MacKinnon, JA Eckert, J Coker, DF Bug, ALR TI Computational study of molecular hydrogen in zeolite Na-A. II. Density of rotational states and inelastic neutron scattering spectra SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID VIBRATIONAL FREQUENCY-SHIFTS; ADSORBED DIATOMIC-MOLECULES; HINDERED ROTATION; HOMONUCLEAR DIATOMICS; SEPARATION FACTORS; CRYSTAL-STRUCTURE; IR-SPECTRA; ADSORPTION; H-2; SODIUM AB Part I of this series [J. Chem. Phys. 111, 7599 (1999)] describes a simulation of H-2 adsorbed within zeolite Na-A in which a block Lanczos procedure is used to generate the first several (9) rotational eigenstates of H-2, modeled as a rigid rotor, and equilibrated at a given temperature via Monte Carlo sampling. Here, we show that rotational states are strongly perturbed by the electrostatic fields in the solid. Wave functions and densities of rotational energy states are presented. Simulated neutron spectra are compared with inelastic neutron scattering data. Comparisons are made with IR spectra in which rotational levels may appear due to rovibrational coupling. (C) 2001 American Institute of Physics. C1 Swarthmore Coll, Dept Phys & Astron, Swarthmore, PA 19081 USA. Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Boston Univ, Dept Chem, Boston, MA 02215 USA. RP Swarthmore Coll, Dept Phys & Astron, Swarthmore, PA 19081 USA. NR 64 TC 19 Z9 19 U1 0 U2 2 PU AMER INST PHYSICS PI MELVILLE PA 1305 WALT WHITMAN RD, STE 300, MELVILLE, NY 11747-4501 USA SN 0021-9606 EI 1089-7690 J9 J CHEM PHYS JI J. Chem. Phys. PD JUN 8 PY 2001 VL 114 IS 22 BP 10137 EP 10150 DI 10.1063/1.1352733 PG 14 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 437NP UT WOS:000168998000054 ER PT J AU Rakovic, MJ Schultz, DR Stancil, PC Janev, RK AF Rakovic, MJ Schultz, DR Stancil, PC Janev, RK TI On quantum-classical correspondence in classical studies of atomic processes SO JOURNAL OF PHYSICS A-MATHEMATICAL AND GENERAL LA English DT Article ID FULLY STRIPPED IONS; ELECTRON-CAPTURE; INTERMEDIATE ENERGIES; MOLECULAR-HYDROGEN; CROSS-SECTIONS; COLLISIONS; DISTRIBUTIONS; IONIZATION; HE; H2 AB A general method for the construction of the optimum classical description of a physical process on the atomic scale is presented. The method is developed for physical systems whose quantum versions are obtained by canonical quantization of their classical counterparts and it is in principle applicable even in the case of 'low' quantum numbers. The criterion determining the optimum description was essentially based on the comparison of the quantum and classical probability distributions in terms of the canonical coordinates. The main application of the method is in classical calculations of various quantities measured in atomic collision processes. C1 Oak Ridge Natl Lab, Div Phys, Oak Ridge, TN 37831 USA. Univ Georgia, Dept Phys & Astron, Athens, GA 30602 USA. Macedonian Acad Sci & Arts, Skopje, Macedonia. RP Rakovic, MJ (reprint author), Oak Ridge Natl Lab, Div Phys, POB 2008, Oak Ridge, TN 37831 USA. NR 20 TC 25 Z9 25 U1 1 U2 3 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0305-4470 J9 J PHYS A-MATH GEN JI J. Phys. A-Math. Gen. PD JUN 8 PY 2001 VL 34 IS 22 BP 4753 EP 4770 DI 10.1088/0305-4470/34/22/314 PG 18 WC Physics, Multidisciplinary; Physics, Mathematical SC Physics GA 445MT UT WOS:000169462100017 ER PT J AU Kind, JA Winn, RN Boerrigter, METI Jagoe, CH Glenn, TC Dallas, CE AF Kind, JA Winn, RN Boerrigter, METI Jagoe, CH Glenn, TC Dallas, CE TI Investigation of the radioadaptive response in brain and liver of pUR288 lacZ transgenic mice SO JOURNAL OF TOXICOLOGY AND ENVIRONMENTAL HEALTH-PART A LA English DT Article ID MOUSE MUTATION ASSAY; ADAPTIVE RESPONSE; HUMAN-LYMPHOCYTES; X-RAYS; INDUCED RADIORESISTANCE; MUTANT FREQUENCIES; POSITIVE SELECTION; IONIZING-RADIATION; DNA-DAMAGE; LOCUS TEST AB The radioadaptive response, where a small priming dose of ionizing radiation can lessen the effects of subsequent exposure to a higher radiation challenge dose, was investigated in brain and liver within transgenic mice. Although it is well characterized in models in vitro, current radioadaptive response research has focused on particular cell types (i.e., lymphocytes) and does nor provide comparative data for responses of multiple tissues within an organism. Transgenic animals are useful for such comparisons, because the transgene is integrated into ail cells in the body. The pUR288 lacZ plasmid-based transgenic mouse model utilizes a plasmid vector allowing highly efficient recovery of mutational targets, including large size-change mutations that result from radiation exposure. Female C57Bl/6 pUR288 lacZ mice were exposed to priming doses of 0.075- to 0.375-Gy x-rays over a 3-d period. After 3 wk. they received an acute challenge dose of 2.5-Gy x-rays. Spontaneous mutant frequencies in lacZ were significantly higher in liver than in brain (6.62 x 10(-5) vs. 3.51 x 10(-5)). in the absence of a priming dose, the 2.5-Gy challenge doubled the mutant frequency of both liver and brain (13.38 x 10(-5), and 7.63 x 10(-5) respectively). Priming doses of 0.15, 0.225, and 0.375 Gy significantly reduced (by 40%) the mutagenic effects of the 2.5-Gy challenge in brain. Restriction enzyme analysis of rescued mutant plasmids revealed a decrease in large size-change mutations at the three priming doses in brain. This study demonstrates the utility of this model for the investigation of radiological processes of large size-change mutations, as well as showing a radioadaptive response in brain, but not liver, of mice in vivo. C1 Univ Georgia, Coll Pharm, Dept Pharmaceut & Biomed Sci, Athens, GA 30602 USA. Terra Inc, Tallahassee, FL USA. Univ Georgia, Sch Forest Resources, Athens, GA USA. Leven Inc, Bogart, GA USA. Univ Georgia, Savannah River Ecol Lab, Aiken, SC USA. RP Dallas, CE (reprint author), Univ Georgia, Coll Pharm, Dept Pharmaceut & Biomed Sci, Athens, GA 30602 USA. RI Glenn, Travis/A-2390-2008 NR 34 TC 3 Z9 3 U1 0 U2 2 PU TAYLOR & FRANCIS LTD PI LONDON PA 11 NEW FETTER LANE, LONDON EC4P 4EE, ENGLAND SN 1528-7394 J9 J TOXICOL ENV HEAL A JI J. TOXICOL. ENV. HEALTH PT A PD JUN 8 PY 2001 VL 63 IS 3 BP 207 EP 220 DI 10.1080/15287390151101565 PG 14 WC Environmental Sciences; Public, Environmental & Occupational Health; Toxicology SC Environmental Sciences & Ecology; Public, Environmental & Occupational Health; Toxicology GA 439MU UT WOS:000169121300004 PM 11405416 ER PT J AU Huang, MH Mao, S Feick, H Yan, HQ Wu, YY Kind, H Weber, E Russo, R Yang, PD AF Huang, MH Mao, S Feick, H Yan, HQ Wu, YY Kind, H Weber, E Russo, R Yang, PD TI Room-temperature ultraviolet nanowire nanolasers SO SCIENCE LA English DT Article ID OPTICAL GAIN; QUANTUM; ZNO AB Room-temperature ultraviolet Lasing in semiconductor nanowire arrays has been demonstrated. The self-organized, <0001> oriented zinc oxide nanowires grown on sapphire substrates were synthesized with a simple vapor transport and condensation process. These wide band-gap semiconductor nanowires form natural Laser cavities with diameters varying from 20 to 150 nanometers and Lengths up to 10 micrometers. Under optical excitation, surface-emitting lasing action was observed at 385 nanometers, with an emission Linewidth less than 0.3 nanometer. The chemical flexibility and the one-dimensionality of the nanowires make them ideal miniaturized Laser Light sources. These short-wave-length nanolasers could have myriad applications, including optical computing, information storage, and microanalysis. C1 Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Environm Energy Technol Div, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Sci Mat, Berkeley, CA 94720 USA. RP Yang, PD (reprint author), Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. RI Wu, Yiying/A-3949-2011 NR 17 TC 7090 Z9 7329 U1 203 U2 1986 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 JUN 8 PY 2001 VL 292 IS 5523 BP 1897 EP 1899 DI 10.1126/science.1060367 PG 3 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 440WY UT WOS:000169200700044 PM 11397941 ER PT J AU Lashley, JC Stout, MG Pereyra, RA Blau, MS Embury, JD AF Lashley, JC Stout, MG Pereyra, RA Blau, MS Embury, JD TI The critical recrystallization strain of delta-plutonium SO SCRIPTA MATERIALIA LA English DT Article DE grain growth; cold working; annealing C1 Los Alamos Natl Lab, Div Mat Sci & Technol, Los Alamos, NM 87545 USA. Lawrence Livermore Natl Lab, Div Mat Sci & Technol, Livermore, CA 94550 USA. McMaster Univ, Dept Mat Sci & Engn, Hamilton, ON, Canada. RP Lashley, JC (reprint author), Los Alamos Natl Lab, Div Mat Sci & Technol, Los Alamos, NM 87545 USA. NR 10 TC 10 Z9 10 U1 0 U2 4 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 JUN 8 PY 2001 VL 44 IS 12 BP 2815 EP 2820 DI 10.1016/S1359-6462(01)00979-4 PG 6 WC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Science & Technology - Other Topics; Materials Science; Metallurgy & Metallurgical Engineering GA 460LD UT WOS:000170308300020 ER PT J AU Yeom, YH Frei, H AF Yeom, YH Frei, H TI Photoactivation of CO in Ti silicalite molecular sieve SO JOURNAL OF PHYSICAL CHEMISTRY A LA English DT Article ID FT-IR SPECTROSCOPY; PHOTOCATALYTIC REDUCTION; TITANIUM SILICALITE; FRAMEWORK TI(IV); ZEOLITE; LIGHT; H2O; MECHANISMS; TI-MCM-41; ALKOXIDES AB Irradiation at 266 nm of Ti silicalite (TS-1) molecular sieve loaded with CO and CH3OH gas at 173 K gave methyl formate as the main product. The photoreaction was monitored in situ by FT-IR spectroscopy and was attributed to reduction of CO at LMCT-excited framework Ti centers under concurrent oxidation of methanol. Infrared product analysis based on experiments with (CO)-O-18, (CO)-C-13, and (CH3OH)-C-13 revealed that carbon monoxide is incorporated into the eater as a carbonyl moiety. It is proposed that CO is photoreduced by transient Ti3+ to HCO radical in the primary redox step. This finding opens up the possibility for synthetic chemistry of carbon monoxide in transition metal materials by photoactivation of framework metal centers. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Phys Biosci Div, Mailstop Calvin Lab, Berkeley, CA 94720 USA. RP Frei, H (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Phys Biosci Div, Mailstop Calvin Lab, Berkeley, CA 94720 USA. NR 37 TC 14 Z9 14 U1 1 U2 8 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 JUN 7 PY 2001 VL 105 IS 22 BP 5334 EP 5339 DI 10.1021/jp004031s PG 6 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 441LW UT WOS:000169232700004 ER PT J AU Thiesemann, H Clifford, EP Taatjes, CA Klippenstein, SJ AF Thiesemann, H Clifford, EP Taatjes, CA Klippenstein, SJ TI Temperature dependence and deuterium kinetic isotope effects in the CH(CD)+C2H4(C2D4) reaction between 295 and 726 K SO JOURNAL OF PHYSICAL CHEMISTRY A LA English DT Article ID TRANSITION-STATE THEORY; VARIABLE REACTION COORDINATE; ASSOCIATION REACTIONS; CH RADICALS; RRKM; RECOMBINATION; DISSOCIATION; INSERTION; (CH2)-C-1; ACETYLENE AB Absolute rate coefficients for the reactions CH + C2H4 (k(1)), CD + C2H4 (k(2)), CH + C2D4 (k(3)), and CD + C2D4 (k(4)) have been measured by the laser photolysis/CW laser-induced fluorescence method at temperatures from 295 to 726 K. The individual rate coefficients can be described by k(1) = (2.85 +/- 0.02) (T/293)(-(0.31) (+/-) (0.02)) x 10(-10) cm(3) molecule(-1) s(-1), k(2) = (2.40 +/- 0.01) (T/293)(-(0.28) (+/- 0.01)) x 10(-10) cm(3) molecule(-1) s(-1), k(3) = (2.61 +/- 0.01) (T/293)(-(0.34 +/- 0.01)) x 10(-10) cm(3) molecule(-1) s(-1), k(4) = (2.22 +/- 0.01) (T/293)(-(0.21 +/- 0.02)) x 10(-10) cm(3) molecule(-1) s(-1), where the error estimates are +/-2 sigma and reflect the precision of the fit. The slight negative temperature dependence is in good agreement with previous determinations of this reaction, and is consistent with barrierless formation of an excited C3H5 adduct followed by rapid decomposition. The kinetic isotope effect for deuteration of the CH radical is k(1)/k(2) = 1.19 +/- 0.04 at room temperature, and declines somewhat with temperature. The kinetic isotope effect for deuteration of the ethylene is k(1)/k(3) = 1.08 +/- 0.04 at 290 K, and is approximately independent of temperature over the range studied. Quantum chemical calculations of the reaction path indicate that the reaction is dominated by addition, with a minor role possible for insertion. C1 Sandia Natl Labs, Combust Res Facil, Livermore, CA 94551 USA. Univ Kiel, Inst Phys Chem, D-24118 Kiel, Germany. RP Taatjes, CA (reprint author), Sandia Natl Labs, Combust Res Facil, Mail Stop 9055, Livermore, CA 94551 USA. OI Klippenstein, Stephen/0000-0001-6297-9187 NR 45 TC 25 Z9 25 U1 1 U2 10 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 JUN 7 PY 2001 VL 105 IS 22 BP 5393 EP 5401 DI 10.1021/jp0045641 PG 9 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 441LW UT WOS:000169232700011 ER PT J AU Reinot, T Zazubovich, V Hayes, JM Small, GJ AF Reinot, T Zazubovich, V Hayes, JM Small, GJ TI New insights on persistent nonphotochemical hole burning and its application to photosynthetic complexes SO JOURNAL OF PHYSICAL CHEMISTRY B LA English DT Review ID ALUMINUM PHTHALOCYANINE TETRASULFONATE; HYPERQUENCHED GLASSY FILMS; RHODOPSEUDOMONAS-ACIDOPHILA STRAIN-10050; BACTERIAL REACTION CENTERS; PRIMARY CHARGE SEPARATION; SYNECHOCYSTIS SP PCC-6803; A ANTENNA STATES; PHOTOSYSTEM-I; LOW-TEMPERATURE; ENERGY-TRANSFER AB Nonphotochemical hole burning (NPHB) at low temperatures of the electronic absorption bands of molecular chromophores imbedded in amorphous solids (glasses and polymers) and in proteins is a striking manifestation of configurational tunneling triggered by electronic excitation. The current mechanism of NPHB has it due to a hierarchy of relaxation events that begin in the outer shell and involve the intrinsic two-level systems (TLSint) of the glass and terminate in the inner shell where the rate determining step involving the extrinsic TLS (TLSext) occurs. The TLS correspond to asymmetric intermolecular double well potentials. The TLSext are associated with the chromophore and the inner shell of solvent molecules. The TLSint are intimately associated with the excess free volume of glasses. Their tunneling leads to diffusion of excess free volume. Results for Al-phthalocyanine tetrasulfonate (APT) in hyperquenched glassy water (HGW) and ethanol (HGE) films that provide strong support for the critical role of excess free volume are discussed. Hole spectra of APT/HGW obtained over eight decades of burn fluence reveal that the current mechanism needs to be modified to include multilevel extrinsic systems (MLSext) in order to explain why the antihole ("photoproduct" absorption) lies to the blue of the burn frequency for sufficiently high burn fluences, an intriguing up-conversion process. The spectra also reveal, for the first time, that the zero-phonon hole (ZPH) profile is non-lorentzian. This is shown to be a natural consequence of the interplay between the three distributions that result in dispersive hole growth kinetics. They are associated with the tunnel parameter lambda of the TLSext, the angle alpha between the laser polarization and transition dipole, and off-resonant absorption of the zero-phonon line (the omega distribution). Theoretical simulations of hole growth data for APT/HGW obtained over six decades of burn fluence show that the lambda distribution is of primary importance, describing well the first 80% of the saturated burn. The paper ends with an application of NPHB combined with high pressure and external electric (Stark) fields to the critically important "red" antenna states of photosystem I. The addition of pressure and Stark fields enhances the already impressive selectivity of NPHB, The results show that the linear pressure shift, permanent dipole moment change, and linear electron-phonon coupling are correlated. Of particular importance is that these properties can be used to identify states which involve interacting chlorophyll molecules that possess significant charge transfer character because of electron-exchange coupling. The results also show that the site distribution functions of the antenna states are largely uncorrelated, consistent with the findings for previously studied complexes. This is important because the absence of correlation means that the electronic energy gaps of donor and acceptor states are distributed which, in turn, means that the kinetics can be dispersive under certain conditions. C1 Iowa State Univ, Dept Chem, Ames, IA 50011 USA. Iowa State Univ, US DOE, Ames Lab, Ames, IA 50011 USA. RP Small, GJ (reprint author), Iowa State Univ, Dept Chem, Ames, IA 50011 USA. NR 105 TC 52 Z9 52 U1 0 U2 7 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 JUN 7 PY 2001 VL 105 IS 22 BP 5083 EP 5098 DI 10.1021/jp010126y PG 16 WC Chemistry, Physical SC Chemistry GA 441LX UT WOS:000169232800003 ER PT J AU Xie, SB Iglesia, E Bell, AT AF Xie, SB Iglesia, E Bell, AT TI Effects of temperature on the Raman spectra and dispersed oxides SO JOURNAL OF PHYSICAL CHEMISTRY B LA English DT Article ID RAY PHOTOELECTRON-SPECTROSCOPY; PENTOXIDE SINGLE CRYSTALS; SILICA XEROGEL MATRIX; VANADIUM PENTOXIDE; LASER RAMAN; OPTICAL ABSORPTION; MOLECULAR-STRUCTURES; LATTICE-VIBRATIONS; CATALYSTS; DEHYDRATION AB An investigation has been conducted of the effects of temperature on the intensities and positions of Raman bands of bulk and supported metal oxides. The relationship of band intensity to optical absorption of the sample at frequencies close to that of the laser used for Raman spectroscopy was also investigated. It was observed that bulk oxides exhibit an increase in optical absorption with increasing temperature due to a loss of oxygen and the consequent formation of nonstoichiometric oxides and stoichiometric suboxides, When the increase in optical absorption is significant at or near the frequency of the laser used for Raman spectroscopy, this gives rise to a loss in Raman signal intensity due to a decrease in the sampling depth. The closer the absorption band edge of the oxide is to the laser frequency and the weaker the metal-oxygen bond in the oxide, the more severe will be the effects of temperature on the intensity of the Raman spectrum. For dispersed metal oxides, the influence of temperature on Raman band intensity becomes less severe as the volume fraction of oxide lowers. Temperature also affects the position of the Raman bands for both bulk and supported metal oxides. With increasing temperature, all Raman bands shift to lower frequencies. This effect is attributable to thermal expansion and changes in the population of the vibrational energy levels with increasing temperature. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Div Chem, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Sci Mat, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Chem Engn, Berkeley, CA 94720 USA. RP Iglesia, E (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Div Chem, Berkeley, CA 94720 USA. EM E.Iglesia@cchem.berkeley.edu; bell@cchem.berkeley.edu RI Iglesia, Enrique/D-9551-2017; OI Iglesia, Enrique/0000-0003-4109-1001; Bell, Alexis/0000-0002-5738-4645 NR 37 TC 60 Z9 60 U1 1 U2 13 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 1520-6106 J9 J PHYS CHEM B JI J. Phys. Chem. B PD JUN 7 PY 2001 VL 105 IS 22 BP 5144 EP 5152 DI 10.1021/jp004434s PG 9 WC Chemistry, Physical SC Chemistry GA 441LX UT WOS:000169232800011 ER PT J AU Chekanov, S AF Chekanov, S TI Suppression of multi-gluon fluctuations in jets at a linear collider SO PHYSICS LETTERS B LA English DT Article ID PHASE-SPACE BINS; MULTIPLICITY FLUCTUATIONS; QCD JETS; MULTIPARTON CORRELATIONS; BUNCHING PARAMETER; HADRON SPECTRA; HIGH-ENERGY; INTERMITTENCY; DECAYS AB It was shown that at typical energies and luminosities of an e(+) e(-) linear collider one can observe a significant suppression of fluctuations of the number of gluons in small angular regions. This property of jets is expected in e(+) e(-) annihilation as well as in any collision producing high energy quarks which give rise to the QCD gluon cascade. The reduction of multiplicity fluctuations was obtained from perturbative QCD using bunching parameters and then cross checked with a Monte Carlo simulation. The parton-level Monte Carlo simulation confirms the prediction, while the hadron level illustrates that the effect survives the hadronization process. (C) 2001 Published by Elsevier Science B.V. C1 Argonne Natl Lab, HEP Div, Argonne, IL 60439 USA. RP Chekanov, S (reprint author), Argonne Natl Lab, HEP Div, 9700 S Cass Ave, Argonne, IL 60439 USA. NR 24 TC 0 Z9 0 U1 1 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0370-2693 J9 PHYS LETT B JI Phys. Lett. B PD JUN 7 PY 2001 VL 509 IS 1-2 BP 74 EP 80 DI 10.1016/S0370-2693(01)00540-8 PG 7 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 444XW UT WOS:000169426200010 ER PT J AU Close, FE Isgur, N AF Close, FE Isgur, N TI The origins of quark-hadron duality: how does the square of the sum become the sum of the squares? SO PHYSICS LETTERS B LA English DT Article ID RESONANCES AB Bloom-Gilman duality demonstrates empirically that the electroproduction of N*'s at low momentum transfers averages smoothly around the scaling curve measured at large momentum transfers. The latter is proportional to the sum of the squares of the constituent charges whereas the former involves the coherent excitation of resonances and is driven by the square of summed constituent charges. We determine the minimal necessary conditions for this equality to be realised so that duality can occur and consider the implications for a range of processes that may be studied soon at CEBAF. (C) 2001 Published by Elsevier Science B.V. C1 Univ Oxford, Dept Theoret Phys, Oxford OX1 3NP, England. Jefferson Lab, Newport News, VA 23606 USA. RP Close, FE (reprint author), Univ Oxford, Dept Theoret Phys, 1 Keble Rd, Oxford OX1 3NP, England. NR 21 TC 90 Z9 90 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 JUN 7 PY 2001 VL 509 IS 1-2 BP 81 EP 86 DI 10.1016/S0370-2693(01)00548-2 PG 6 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 444XW UT WOS:000169426200011 ER PT J AU Enomoto, A Takakuwa, Y Manno, S Tanaka, A Mohandas, N AF Enomoto, A Takakuwa, Y Manno, S Tanaka, A Mohandas, N TI Regulation of erythrocyte ghost membrane mechanical stability by chlorpromazine SO BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES LA English DT Article DE chlorpromazine; erythrocyte; membrane stability; spectrin ID BAND 3-ANKYRIN INTERACTION; INDUCED SHAPE CHANGE; PHOSPHOLIPID ASYMMETRY; CELL MEMBRANES; SPECTRIN; DEFORMABILITY; TRANSMEMBRANE; SKELETAL; PHOSPHORYLATION; MODULATION AB Chlorpromazine (CPZ), a widely used tranquilizer, is known to induce stomatocytic shape changes in human erythrocytes. However, the effect of CPZ on membrane mechanical properties of erythrocyte membranes has not been documented. In the present study we show that CPZ induces a dose-dependent increase in mechanical stability of erythrocyte ghost membrane. Furthermore, we document that spectrin specifically binds to CPZ intercalated into inside-out vesicles depleted of all peripheral proteins. These findings imply that CPZ-induced mechanical stabilization of the erythrocyte ghost membranes may be mediated by direct binding of spectrin to the bilayer. Membrane active drugs that partition into lipid bilayer can thus induce cytoskeletal protein interactions with the membrane and modulate membrane material properties. (C) 2001 Published by Elsevier Science B.V. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Div Life Sci, Berkeley, CA 94720 USA. Tokyo Womens Med Univ, Dept Psychiat, Tokyo 1628666, Japan. Tokyo Womens Med Univ, Dept Biochem, Tokyo 1628666, Japan. RP Mohandas, N (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Div Life Sci, Mailstop 74-157,1 Cyclotron Rd, Berkeley, CA 94720 USA. FU NIDDK NIH HHS [DK26263] NR 30 TC 10 Z9 10 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0005-2736 J9 BBA-BIOMEMBRANES JI Biochim. Biophys. Acta-Biomembr. PD JUN 6 PY 2001 VL 1512 IS 2 BP 285 EP 290 DI 10.1016/S0005-2736(01)00329-7 PG 6 WC Biochemistry & Molecular Biology; Biophysics SC Biochemistry & Molecular Biology; Biophysics GA 444TG UT WOS:000169415700014 PM 11406105 ER PT J AU Kinney, JH Marshall, GW Marshall, SJ Haupt, DL AF Kinney, JH Marshall, GW Marshall, SJ Haupt, DL TI Three-dimensional imaging of large compressive deformations in elastomeric foams SO JOURNAL OF APPLIED POLYMER SCIENCE LA English DT Article DE mechanical properties; foam; microtomography; finite-element modeling; elastomer; percolation theory ID RAY TOMOGRAPHIC MICROSCOPY; TRABECULAR BONE; SYNCHROTRON-RADIATION; COMPUTED-TOMOGRAPHY; BEHAVIOR AB Specimens of silica-reinforced polysiloxane foam pads were three-dimensionally imaged during axial compressive loading to densification. The foams' behavior was highly nonlinear and showed the three characteristic regions of linear elastic, elastic buckling, and densification. A finite-element technique, based upon conversion of the image voxels to finite elements, was used to calculate the mechanical properties of the foams. The results were compared with conventional mechanical testing and theory. The finite-element calculations were in excellent agreement with experimental stress-strain data over the entire range of compressive loading. Theoretical models, on the other hand, overestimated the stiffness of the foam above the elastic buckling stress by not correctly predicting the abruptness of the transition from elastic buckling to densification. Three-dimensional analysis of the deformed microstructures indicated that there was a critical foam density beyond which the cell morphology suddenly changed from open-celled to closed-celled and that this "phase"-like transition was responsible for the abrupt increase in stiffness near densification. (C) 2001 John Wiley & Sons, Inc. C1 Univ Calif San Francisco, Sch Dent, Dept Restorat Dent, San Francisco, CA 94143 USA. Univ Calif Lawrence Livermore Natl Lab, Dept Mech Engn, Livermore, CA 94551 USA. RP Kinney, JH (reprint author), Univ Calif San Francisco, Sch Dent, Dept Restorat Dent, San Francisco, CA 94143 USA. NR 19 TC 28 Z9 28 U1 3 U2 10 PU JOHN WILEY & SONS INC PI NEW YORK PA 605 THIRD AVE, NEW YORK, NY 10158-0012 USA SN 0021-8995 J9 J APPL POLYM SCI JI J. Appl. Polym. Sci. PD JUN 6 PY 2001 VL 80 IS 10 BP 1746 EP 1755 DI 10.1002/app.1269 PG 10 WC Polymer Science SC Polymer Science GA 416DC UT WOS:000167764100017 ER PT J AU Gallagher, LA Meyer, TJ AF Gallagher, LA Meyer, TJ TI Surface control of oxidation by an adsorbed Ru-IV-oxo complex SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Article ID COUPLED ELECTRON-TRANSFER; TITANIUM-DIOXIDE; HYDRIDE TRANSFER; BENZYL ALCOHOL; ATOM-TRANSFER; EPOXIDATION; RUTHENIUM(IV); TIO2; <(BPY)2(PY)RU(O)>2+; MECHANISMS AB When adsorbed to optically transparent,,thin films of TiO2 nanoparticles on glass, the aqua complex [Ru-II (typ)(bpy(PO3H2)(2))(OH2)](2+) (bpy(PO3H2)(2) is 2,2'-bipyridyl-4,4'-diphosphonic acid; tpy is 2,2':6',2"-terpyridine) is oxidized by Ce-IV(NH4)(2)(NO3)(6) in 0.1 M HClO4 to its Ru-IV=O2+ form as shown by UV-visible measurements and analysis of oxidative equivalents by oxidation of hydroquinone to quinone. Kinetic studies on the oxidations of cyclohexene, benzyl alcohol, phenol, and tr-ans-stilbene by surface-bound Ru-IV=O2+ by UV-visible monitoring reveal direct evidence for initial 2-electron steps to give Ru-II intermediates in all four cases. These steps are masked in solution where Ru-IV --> Ru-II reduction is followed by rapid reactions between Ru-II intermediates and Ru-IV=O2+ to give Ru-III. Reactions between Ru-II and Ru-IV = O2(+) on the surface are inhibited by binding to the surface, which restricts translational mobility. Rate constants on the surface and in solution are comparable, pointing to comparable reactivities. The surface experiments give unprecedented insight into oxidation mechanism with important implications for achieving product selectivity in synthesis by limiting oxidation to two electrons. C1 Univ N Carolina, Dept Chem, Chapel Hill, NC 27599 USA. RP Meyer, TJ (reprint author), Univ Calif Los Alamos Natl Lab, MS A127, Los Alamos, NM 87545 USA. NR 35 TC 29 Z9 29 U1 0 U2 13 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 JUN 6 PY 2001 VL 123 IS 22 BP 5308 EP 5312 DI 10.1021/ja000971e PG 5 WC Chemistry, Multidisciplinary SC Chemistry GA 438ET UT WOS:000169041300017 PM 11457393 ER PT J AU Pauleta, SR Lu, Y Goodhew, CF Moura, I Pettigrew, GW Shelnutt, JA AF Pauleta, SR Lu, Y Goodhew, CF Moura, I Pettigrew, GW Shelnutt, JA TI Calcium-dependent conformation of a heme and fingerprint peptide of the diheme cytochrome c peroxidase from Paracoccus pantotrophus SO BIOCHEMISTRY LA English DT Article ID RESONANCE RAMAN-SPECTRA; PSEUDOMONAS-AERUGINOSA; SPIN STATE; PORPHYRINS; DENITRIFICANS; DISTORTIONS; SPECTROSCOPY; PROTEIN; OCTAETHYLPORPHYRIN; SPECIFICITY AB The structural changes in the heme macrocycle and substituents caused by binding of Ca2+ to the diheme cytochrome c peroxidase from Paracoccus pantotrophus were clarified by resonance Raman spectroscopy of the inactive fully oxidized form of the enzyme. The changes in the macrocycle vibrational modes are consistent with a Ca2+-dependent increase in the out-of-plane distortion of the low-potential heme, the proposed peroxidatic heme. Most of the increase in out-of-plane distortion occurs when the high-affinity site I is occupied, but a small further increase in distortion occurs when site II is also occupied by Ca2+ or Mg2+. This increase in the heme distortion explains the red shift in the Soret absorption band that occurs upon Ca2+ binding. Changes also occur in the low-frequency substituent modes of the heme, indicating that a structural change in the covalently attached fingerprint pentapeptide of the LP heme occurs upon Ca2+ binding to site I. These structural changes may lead to loss of the sixth ligand at the peroxidatic heme in the semireduced form of the enzyme and activation. C1 Sandia Natl Labs, Biomol Mat & Interfaces Dept, Albuquerque, NM 87185 USA. Univ Nova Lisboa, Fac Ciencias & Tecnol, Ctr Quim Fina & Biotecnol, P-2825 Monte De Caparica, Portugal. Univ Edinburgh, Royal Dick Sch Vet Studies, Dept Vet Preclin Sci, Edinburgh EH9 1QH, Midlothian, Scotland. Univ New Mexico, Dept Chem, Albuquerque, NM 87131 USA. RP Shelnutt, JA (reprint author), Sandia Natl Labs, Biomol Mat & Interfaces Dept, POB 5800, Albuquerque, NM 87185 USA. RI Shelnutt, John/A-9987-2009; Pauleta, Sofia/F-3619-2011; REQUIMTE, SMB/M-5694-2013; Moura, Isabel/D-6339-2013; REQUIMTE, UCIBIO/N-9846-2013 OI Shelnutt, John/0000-0001-7368-582X; Pauleta, Sofia/0000-0002-2149-9416; Moura, Isabel/0000-0003-0971-4977; NR 42 TC 9 Z9 9 U1 0 U2 2 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0006-2960 J9 BIOCHEMISTRY-US JI Biochemistry PD JUN 5 PY 2001 VL 40 IS 22 BP 6570 EP 6579 DI 10.1021/bi002870z PG 10 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA 441LQ UT WOS:000169232200003 PM 11380251 ER PT J AU Buchko, GW Isern, NG Spicer, LD Kennedy, MA AF Buchko, GW Isern, NG Spicer, LD Kennedy, MA TI Human nucleotide excision repair protein XPA: NMR spectroscopic studies of an XPA fragment containing the ERCC1-binding region and the minimal DNA-binding domain (M59-F219) SO MUTATION RESEARCH-DNA REPAIR LA English DT Article DE DNA repair; chemical shift mapping; hydroxyapatite ID DAMAGED-DNA; STRUCTURAL FEATURES; MAMMALIAN-CELLS; RECOGNITION; NUCLEASE; RPA; COMPLEX; MECHANISM; ERCC1; SENSITIVITY AB XPA is a central protein component of nucleotide excision repair (NER), a ubiquitous, multi-component cellular pathway responsible for the removal and repair of many structurally distinct DNA lesions from the eukaryotic genome. The solution structure of the minimal DNA-binding domain of XPA (XPA-MBD: M98-F219) has recently been determined and chemical shift mapping experiments with N-15-labeled XPA-MBD show that XPA binds DNA along a basic surface located in the C-terminal loop-rich subdomain. Here, XPA-DNA interactions are further characterized using an XPA fragment containing the minimal DNA-binding domain plus the ERCC1-binding region (XPA-EM: M59-F219). The N-15/H-1 HSQC spectrum of XPA-EM closely maps onto the N-15/H-1 HSQC spectrum of XPA-MBD, suggesting the DNA-binding domain is intact in the larger XPA fragment. Such a conclusion is corroborated by chemical shift mapping experiments of XPA-EM with a single strand DNA oligomer, dCCAATAACC (d9), that show the same set of N-15/H-1 HSQC cross peaks are effected by the addition of DNA. However, relative to DNA-free XPA-MBD, the N-15/H-1 HSQC cross peaks of many of the basic residues in the loop-rich subdomain of DNA-free XPA-EM are less intense, or gone altogether, suggesting the acidic ERRC1-binding region of XPA-EM may associate transiently with the basic DNA-binding surface. While the DNA-binding domain in XPA-EM is structured and functional, N-15-edited NOESY spectra of XPA-EM indicate that the acidic ERRC1-binding region is unstructured. If the structural features observed for XPA-EM persist in XPA, transient intramolecular association of the ERCC1-binding domain with the DNA-binding region may play a role in the sequential assembly of the NER components. (C) 2001 Elsevier Science B.V. All rights reserved. C1 Pacific NW Natl Lab, Environm Mol Sci Lab, Richland, WA 99352 USA. Duke Univ, Med Ctr, Dept Biochem, Durham, NC 27710 USA. Duke Univ, Med Ctr, Dept Radiobiol, Durham, NC 27710 USA. RP Kennedy, MA (reprint author), Pacific NW Natl Lab, Environm Mol Sci Lab, Richland, WA 99352 USA. RI Buchko, Garry/G-6173-2015; Isern, Nancy/J-8016-2013 OI Buchko, Garry/0000-0002-3639-1061; Isern, Nancy/0000-0001-9571-8864; FU NCI NIH HHS [CM 41829] NR 50 TC 10 Z9 11 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-8777 J9 MUTAT RES-DNA REPAIR JI Mutat. Res.-DNA Repair PD JUN 5 PY 2001 VL 486 IS 1 BP 1 EP 10 DI 10.1016/S0921-8777(01)00072-6 PG 10 WC Biotechnology & Applied Microbiology; Genetics & Heredity; Toxicology SC Biotechnology & Applied Microbiology; Genetics & Heredity; Toxicology GA 435EB UT WOS:000168863500001 PM 11356331 ER PT J AU Qi, SY Groves, JT Chakraborty, AK AF Qi, SY Groves, JT Chakraborty, AK TI Synaptic pattern formation during cellular recognition SO PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA LA English DT Article ID IMMUNOLOGICAL SYNAPSE; SUPPORTED BILAYERS; LATERAL MOBILITY; ACTIVATION; RECEPTORS; ADHESION; PROTEINS; COSTIMULATION; AFFINITY; COMPLEX AB Cell-cell recognition often requires the formation of a highly organized pattern of receptor proteins (a synapse) in the intercellular junction. Recent experiments [e.g., Monks, C. R. F., Freiberg, B. A., Kupfer, H., Sciaky, N. & Kupfer, A. (1998) Nature (London) 395, 82-86; Grakoui, A., Bromley, S. K., Sumen, C., Davis, M. M., Shaw, A. S., Alien, P. M. & Dustin. M. L. (1999) Science 285, 221-227; and Davis, D. M., Chiu, I., Fassett, M., Cohen, C. B., Mandelboim, O. & Strominger, J. L. (1999) Proc. Natl. Acad. Sci. USA 96, 15062-15067] vividly demonstrate a complex evolution of cell shape and spatial receptor-ligand patterns (several microns in size) in the intercellular junction during immunological synapse formation. The current view is that this dynamic rearrangement of proteins into organized supramolecular activation clusters is driven primarily by active cytoskeletal processes [e.g., Dustin, M. L. & Cooper, J. A. (2000) Nat. Immunol. 1, 23-29; and Wulfing, C. & Davis, M. M.(1998) Science 282, 2266-2269]. Here, aided by a quantitative analysis of the relevant physico-chemical processes, we demonstrate that the essential characteristics of synaptic patterns observed in living cells can result from spontaneous self-assembly processes. Active cellular interventions are superimposed on these self-organizing tendencies and may also serve to regulate the spontaneous processes. We find that the protein binding/dissociation characteristics, protein mobilities, and membrane constraints measured in the cellular environment are delicately balanced such that the length and time scales of spontaneously evolving patterns are in near-quantitative agreement with observations for synapse formation between T cells and supported membranes [Grakoui, A., Bromley, S. K., Sumen. C., Davis, M. M., Shaw, A. S., Alien. P. M. & Dustin, M. L.. (1999) Science 285, 221-227]. The model we present provides a common way of analyzing immunological synapse formation in disparate systems (e.g., T cell/antigen-presenting cell junctions with different MHC-peptides. natural killer cells, etc.). C1 Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Dept Chem Engn, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Dept Chem, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Phys Biosci Div, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Div Sci Mat, Berkeley, CA 94720 USA. RP Chakraborty, AK (reprint author), Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Dept Chem Engn, Berkeley, CA 94720 USA. NR 32 TC 230 Z9 232 U1 1 U2 19 PU NATL ACAD SCIENCES PI WASHINGTON PA 2101 CONSTITUTION AVE NW, WASHINGTON, DC 20418 USA SN 0027-8424 J9 P NATL ACAD SCI USA JI Proc. Natl. Acad. Sci. U. S. A. PD JUN 5 PY 2001 VL 98 IS 12 BP 6548 EP 6553 DI 10.1073/pnas.111536798 PG 6 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 440AT UT WOS:000169151500006 PM 11371622 ER PT J AU Watanabe, CMH Wolffram, S Ader, P Rimbach, G Packer, L Maguire, JJ Schultz, PG Gohil, K AF Watanabe, CMH Wolffram, S Ader, P Rimbach, G Packer, L Maguire, JJ Schultz, PG Gohil, K TI The in vivo neuromodulatory effects of the herbal medicine ginkgo biloba SO PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA LA English DT Article ID NEUROFIBRILLARY DEGENERATION; PUR-ALPHA; GLUR-B; PROTEIN; TRANSTHYRETIN; PROLACTIN; QUERCETIN; BRAIN; TAU; DIFFERENTIATION AB Extracts of Ginkgo biloba leaves are consumed as dietary supplements to counteract chronic, age-related neurological disorders. We have applied high-density oligonucleotide microarrays to define the transcriptional effects in the cortex and hippocampus of mice whose diets were supplemented with the herbal extract. Gene expression analysis focused on the mRNAs that showed a more than 3-fold change in their expression. In the cortex, mRNAs for neuronal tyrosine/threonine phosphatase 1, and microtubule-associated tau were significantly enhanced. Hyperphosphorylated tau is the major constituent of the neurofibrillary tangles in the brains of Alzheimer's disease patients. The expression of alpha -amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA)-2, calcium and chloride channels, prolactin, and growth hormone (GH). all of which are associated with brain function, were also up-regulated. In the hippocampus, only transthyretin mRNA was upregulated, Transthyretin plays a role in hormone transport in the brain and possibly a neuroprotective role by amyloid-beta sequestration. This study reveals that diets supplemented with Ginkgo biloba extract have notable neuromodulatory effects in vivo and illustrates the utility of genome-wide expression monitoring to investigate the biological actions of complex extracts. C1 Scripps Res Inst, Dept Chem, La Jolla, CA 92037 USA. Univ Kiel, Inst Anim Nutr Physiol & Metab, D-24118 Kiel, Germany. Univ Reading, Sch Food Biosci, Hugh Sinclair Human Nutr Unit, Reading RG6 6AP, Berks, England. Univ So Calif, Sch Pharm, Los Angeles, CA 90033 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Environm Energy Technol Div, Berkeley, CA 94720 USA. Univ Calif Davis, Dept Internal Med, Davis, CA 95616 USA. RP Schultz, PG (reprint author), Scripps Res Inst, Dept Chem, La Jolla, CA 92037 USA. RI Watanabe, Coran/B-7488-2015; Rimbach, Gerald/A-7178-2011 OI Rimbach, Gerald/0000-0001-7888-4684 FU PHS HHS [EM-27345-21] NR 30 TC 165 Z9 181 U1 3 U2 12 PU NATL ACAD SCIENCES PI WASHINGTON PA 2101 CONSTITUTION AVE NW, WASHINGTON, DC 20418 USA SN 0027-8424 J9 P NATL ACAD SCI USA JI Proc. Natl. Acad. Sci. U. S. A. PD JUN 5 PY 2001 VL 98 IS 12 BP 6577 EP 6580 DI 10.1073/pnas.111126298 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 440AT UT WOS:000169151500011 PM 11381109 ER PT J AU Miao, JW Hodgson, KO Sayre, D AF Miao, JW Hodgson, KO Sayre, D TI An approach to three-dimensional structures of biomolecules by using single-molecule diffraction images SO PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA LA English DT Article ID X-RAY CRYSTALLOGRAPHY; MASS-SPECTROMETRY; ATOMIC-RESOLUTION; PHASE RETRIEVAL; RECONSTRUCTION AB We describe an approach to the high-resolution three-dimensional structural determination of macromolecules that utilizes ultrashort, intense x-ray pulses to record diffraction data in combination with direct phase retrieval by the oversampling technique. It is shown that a simulated molecular diffraction pattern at 2.5-Angstrom resolution accumulated from multiple copies of single rubisco biomolecules, each generated by a femtosecond-level x-ray free electron laser pulse, can be successfully phased and transformed into an accurate electron density map comparable to that obtained by more conventional methods. The phase problem is solved by using an iterative algorithm with a random phase set as an initial input. The convergence speed of the algorithm is reasonably fast, typically around a few hundred iterations. This approach and phasing method do not require any ab initio information about the molecule, do not require an extended ordered lattice array, and can tolerate high noise and some missing intensity data at the center of the diffraction pattern. With the prospects of the x-ray free electron lasers, this approach could provide a major new opportunity for the high-resolution three-dimensional structure determination of single biomolecules. C1 Stanford Univ, Stanford Linear Accelerator Ctr, Stanford Synchrotron Radiat Lab, Stanford, CA 94309 USA. Stanford Univ, Dept Chem, Stanford, CA 94305 USA. SUNY Stony Brook, Dept Phys & Astron, Stony Brook, NY 11794 USA. RP Miao, JW (reprint author), Stanford Univ, Stanford Linear Accelerator Ctr, Stanford Synchrotron Radiat Lab, Stanford, CA 94309 USA. EM miao@ssrl.slac.stanford.edu NR 24 TC 117 Z9 119 U1 1 U2 14 PU NATL ACAD SCIENCES PI WASHINGTON PA 2101 CONSTITUTION AVE NW, WASHINGTON, DC 20418 USA SN 0027-8424 J9 P NATL ACAD SCI USA JI Proc. Natl. Acad. Sci. U. S. A. PD JUN 5 PY 2001 VL 98 IS 12 BP 6641 EP 6645 DI 10.1073/pnas.111083998 PG 5 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 440AT UT WOS:000169151500022 PM 11390993 ER PT J AU Gor'kov, L Kresin, V AF Gor'kov, L Kresin, V TI Giant magnetic effects and oscillations in antiferromagnetic Josephson weak links SO APPLIED PHYSICS LETTERS LA English DT Article ID METALLIC STATE; MANGANITES; MAGNETORESISTANCE; SUPERLATTICES; ND1-XSRXMNO3; TRANSITION AB Josephson junctions with an antiferromagnetic metal as a link are described. An especially interesting case is provided by a barrier built on a giant magnetoresistance multilayer or by using doped manganites in the metallic A-phase. Such a junction is predicted to display unusual properties. The junction can be switched off by a relatively small magnetic field. In addition, the amplitude of the Josephson current rapidly oscillates as a function of the field. (C) 2001 American Institute of Physics. C1 Florida State Univ, Natl High Magnet Field Lab, Tallahassee, FL 32310 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. Russian Acad Sci, LD Landau Theoret Phys Inst, Moscow 117334, Russia. RP Gor'kov, L (reprint author), Florida State Univ, Natl High Magnet Field Lab, Tallahassee, FL 32310 USA. NR 16 TC 7 Z9 7 U1 2 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 JUN 4 PY 2001 VL 78 IS 23 BP 3657 EP 3659 DI 10.1063/1.1377310 PG 3 WC Physics, Applied SC Physics GA 437NC UT WOS:000168996900030 ER PT J AU Muck, M Clarke, J AF Muck, M Clarke, J TI Harmonic distortion and intermodulation products in the microstrip amplifier based on a superconducting quantum interference device SO APPLIED PHYSICS LETTERS LA English DT Article AB The harmonic distortion and intermodulation products have been measured for a microstrip amplifier based on a dc superconducting quantum interference device. When the flux bias is adjusted to maximize the gain, in general both second harmonic and a series of odd harmonics are observed. The magnitude of the third harmonic is in good agreement with a simple model. The magnitude of the second harmonic, however, depends critically on the flux bias and is generally a minimum when the gain is slightly less than the maximum value. Similar results are found for the two lowest order intermodulation products. (C) 2001 American Institute of Physics. 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 Giessen, Inst Appl Phys, Heinrich-Buff-Ring 16, D-35392 Giessen, Germany. EM jclarke@physics.berkely.edu NR 10 TC 4 Z9 4 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 JUN 4 PY 2001 VL 78 IS 23 BP 3666 EP 3668 PG 3 WC Physics, Applied SC Physics GA 437NC UT WOS:000168996900033 ER PT J AU Paranthaman, M Cantoni, C Zhai, HY Christen, HM Aytug, T Sathyamurthy, S Specht, ED Thompson, JR Lowndes, DH Kerchner, HR Christen, DK AF Paranthaman, M Cantoni, C Zhai, HY Christen, HM Aytug, T Sathyamurthy, S Specht, ED Thompson, JR Lowndes, DH Kerchner, HR Christen, DK TI Superconducting MgB2 films via precursor postprocessing approach SO APPLIED PHYSICS LETTERS LA English DT Article AB Superconducting MgB2 films with T-c=38.6 K were prepared using a precursor-deposition, ex situ postprocessing approach. Precursor films of boron, similar to0.5 mum thick, were deposited onto Al2O3 (102) substrates by electron-beam evaporation; a postanneal at 890 degreesC in the presence of bulk MgB2 and Mg metal produced highly crystalline MgB2 films. X-ray diffraction indicated that the films exhibit some degree of c-axis alignment, but are randomly oriented in plane. Transport current measurements of the superconducting properties show high values of the critical current density and yield an irreversibility line that exceeds that determined by magnetic measurements on bulk polycrystalline materials. (C) 2001 American Institute of Physics. C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Paranthaman, M (reprint author), Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RI Christen, David/A-9709-2008; Christen, Hans/H-6551-2013; Specht, Eliot/A-5654-2009; Paranthaman, Mariappan/N-3866-2015; Cantoni, Claudia/G-3031-2013 OI Christen, Hans/0000-0001-8187-7469; Specht, Eliot/0000-0002-3191-2163; Paranthaman, Mariappan/0000-0003-3009-8531; Cantoni, Claudia/0000-0002-9731-2021 NR 13 TC 113 Z9 119 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 JUN 4 PY 2001 VL 78 IS 23 BP 3669 EP 3671 DI 10.1063/1.1377323 PG 3 WC Physics, Applied SC Physics GA 437NC UT WOS:000168996900034 ER PT J AU Matonic, JH Scott, BL Neu, MP AF Matonic, JH Scott, BL Neu, MP TI High-yield synthesis and single-crystal X-ray structure of a plutonium(III) aquo complex: [Pu(H2O)9][CF3SO3](3) SO INORGANIC CHEMISTRY LA English DT Article ID NONAAQUALANTHANOID(III) TRIS(TRIFLUOROMETHANESULFONATES); CHLORIDE SOLUTIONS; IONS; SPECTROSCOPY; HYDRATION; NUMBER AB The aquo complex of Pu(III) is 9-coordinate with an ideal tricapped trigonal-prismatic geometry. The cation was crystallized as the triflate salt in quantitative yield from dissolution of Pu metal in triflic acid. Structural comparisons with analogous lanthanide aquo complexes are presented. C1 Los Alamos Natl Lab, Div Chem, Los Alamos, NM 87545 USA. RP Neu, MP (reprint author), Los Alamos Natl Lab, Div Chem, POB 1663, Los Alamos, NM 87545 USA. RI Scott, Brian/D-8995-2017; OI Scott, Brian/0000-0003-0468-5396; Matonic, John/0000-0002-6059-1514 NR 17 TC 50 Z9 50 U1 0 U2 6 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 JUN 4 PY 2001 VL 40 IS 12 BP 2638 EP 2639 DI 10.1021/ic015509p PG 2 WC Chemistry, Inorganic & Nuclear SC Chemistry GA 439GE UT WOS:000169101800004 PM 11375672 ER PT J AU Chi, LS Corbett, JD AF Chi, LS Corbett, JD TI K6Tl2Sb3, a zintl phase with a novel heteroatomic (1)(infinity)[Tl4Sb612-] chain SO INORGANIC CHEMISTRY LA English DT Article ID CRYSTAL-STRUCTURE; CLUSTERS; COMPOUND; LAYERS; CS; RB AB The title compound with heteratomic anionic chains (1)(infinity)[Tl4Sb612-] has been discovered in the K-Tl-Sb system. The phase is obtained from a range of compositions near K3TlSb1.5 following reaction first at 750-850 degreesC and then at 550 degreesC for one week or more. It crystallizes in the monoclinic system in space group C2/c, Z = 8, a = 9.951(1) Angstrom, b = 17.137(3) Angstrom, c = 19.640(6) Angstrom, and beta = 104.26(3)degrees Swing-like (Tl4Sb6)(12-) units consisting of alternating Sb and Tl atoms in four- and eight-membered rings are linked through Tl-Tl bonds to form infinite one-dimensional chains along (a) over bar. EHTB calculations and resistivity measurements show that the compound is a semiconductor. C1 Iowa State Univ, Ames Lab, US DOE, Ames, IA 50011 USA. Iowa State Univ, Dept Chem, Ames, IA 50011 USA. RP Corbett, JD (reprint author), Iowa State Univ, Ames Lab, US DOE, Ames, IA 50011 USA. NR 26 TC 6 Z9 6 U1 0 U2 2 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 JUN 4 PY 2001 VL 40 IS 12 BP 2705 EP 2708 DI 10.1021/ic0014134 PG 4 WC Chemistry, Inorganic & Nuclear SC Chemistry GA 439GE UT WOS:000169101800015 PM 11375683 ER PT J AU Nemes, A Bakac, A AF Nemes, A Bakac, A TI Disproportionation of aquachromyl(IV) ion by hydrogen abstraction from coordinated water SO INORGANIC CHEMISTRY LA English DT Article ID CHROMIC ACID OXIDATION; SUPEROXOMETAL COMPLEXES; PULSE-RADIOLYSIS; AQUEOUS-SOLUTION; ATOM TRANSFER; CHROMIUM(VI); THERMODYNAMICS; CHEMISTRY; REDUCTION; KINETICS AB In aqueous solutions, the aquachromyl(IV) ion, CraqO2+, disproportionates to Cr-aq(3+) and HCrO4-. The reaction exhibits second-order kinetics with an inverse [H+] dependence, -d[CraqO2+]/dt = 38.8[CraqO2+](2)[H+](-1) at 25 degreesC. The combination of the rate law and substantial kinetic isotope effect, k(H)/k(D) = 6.9, suggests a mechanism whereby a hydrogen atom is abstracted from a coordinated molecule of water or hydroxo group within a singly deprotonated transition state. The buildup of chromate is more complicated and somewhat slower than the loss of chromyl, suggesting the involvement of intermediates. C1 Iowa State Univ, Ames Lab, Ames, IA 50011 USA. RP Bakac, A (reprint author), Iowa State Univ, Ames Lab, Ames, IA 50011 USA. NR 42 TC 21 Z9 21 U1 0 U2 3 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 JUN 4 PY 2001 VL 40 IS 12 BP 2720 EP 2724 DI 10.1021/ic0013577 PG 5 WC Chemistry, Inorganic & Nuclear SC Chemistry GA 439GE UT WOS:000169101800018 PM 11375686 ER PT J AU Brittingham, KA Espenson, JH AF Brittingham, KA Espenson, JH TI Thermodynamics, kinetics, and mechanism of the reversible formation of oxorhenium(VII) catecholate complexes SO INORGANIC CHEMISTRY LA English DT Article ID MAIN-GROUP ELEMENTS; MOLECULAR-STRUCTURE; TRANSITION-METALS; MULTIPLE BONDS; DYNAMIC BEHAVIOR; CRYSTAL; LIGANDS; RHENIUM(V); .0.75C7H8; METHYLTRIOXORHENIUM(VII) AB Mononuclear Re(V) compounds MeReO(mtp)NC5H4X, 3, where mtpH(2) is 2-(mercaptomethyl) thiophenol have been prepared from the monomerization of {MeReO(mtp)}(2) by pyridines with electron-donating substituents in the para or meta position; X = 4-Me, 4-Bu-t, 3-Me, 4-Ph, and H. Analogous compounds, MeReO(edt)N5H4X, 4, edtH(2) = 1,2-ethanedithiol, were prepared similarly. The equilibrium constants for the reaction, dimer + 2Py 2M-Py, are in the range (2.5-31.6) x 10(2) L mol(-1). Both groups of monomeric compounds react with quinones (phenanthrenequinone, PQ, and 3,5-tert-butyl-1,2-benzoquinone, DBQ), displacing the pyridine ligand and forming Re(VII) catecholate complexes MeReO(dithiolate)PCat and MeReO(dithiolate)DBCat. With PQ, the reaction MeReO(dithiolate)Py + PQ = MeReO(dithiolate)PCat + Py is an equilibrium; values of K-Q for different Py ligands lie in the ranges 9.2-42.7 (mtp) and 3.2-11.2 (edt) at 298 K. These second-order rate constants (L mol(-1) s(-1)) at 25 degreesC in benzene were obtained for the PQ reactions: k(f) = (5.3-15.5) x 10(-2) (mtp), (6.6-16.4) x 10(-2)(edt); k(r) = (3.63-5.71) x 10(-3) (mtp), (14.7-22.0) x 10(-3) (edt). The ranges in each case refer to the series of pyridine ligands, the forward rate constant being the largest for C5K5N, with the lowest Lewis basicity. The reactions of MeReO(dithiolate)Py with DBQ proceed to completion. Values of k(f)/L mol(-1) s(-1) fall in a narrow range, 4.02 (X = Bu-t) to 8.4 (X = H) with the dithiolate being mtp. C1 Iowa State Univ Sci & Technol, Ames Lab, Ames, IA 50011 USA. Iowa State Univ Sci & Technol, Dept Chem, Ames, IA 50011 USA. RP Espenson, JH (reprint author), Iowa State Univ Sci & Technol, Ames Lab, Ames, IA 50011 USA. NR 42 TC 1 Z9 1 U1 1 U2 3 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 JUN 4 PY 2001 VL 40 IS 12 BP 2730 EP 2736 DI 10.1021/ic001188q PG 7 WC Chemistry, Inorganic & Nuclear SC Chemistry GA 439GE UT WOS:000169101800020 PM 11375688 ER PT J AU Sylwester, ER Allen, PG Dharmawardana, UR Sutton, M AF Sylwester, ER Allen, PG Dharmawardana, UR Sutton, M TI Structural studies of uranium and thorium complexes with 4,5-dihydroxy-3,5-benzenesdisulfonate (Tiron) at low and neutral pH by X-ray absorption spectroscopy SO INORGANIC CHEMISTRY LA English DT Article ID FINE-STRUCTURE SPECTROSCOPY; AQUEOUS-SOLUTION; CARBONATE COMPLEXES; EXAFS; COORDINATION; IONS AB We have determined the structure of uranyl, UO22+, and Th4+ complexes formed in aqueous solution with 4,5-dihydroxy-3,5-benzenedisulfonate (Tiron) as function of PH and concentration. At equimolar concentrations of 0.05 M UO22+ and Tiron, the predominant species was found to be aqueous uranyl at pH = 2.0. At pH = 6.0, the formation of a 3:3 UO22+:Tiron trimer (proposed in earlier studies) was observed. In this structure, bidentate catecholate complexation to Tiron as well as oxygen bridging between uranyl units is detected. Th4+ structural changes were observed both as a function of pH and Th:L (L = Tiron) ratio. At Th:L = 1:1 and pH = 1.4, a monomeric complex is observed with each Th center complexing monodentate to similar to2 sulfonate functional groups. At pH 4.0 similar sulfonate ligation is observed along with oligomer formation. At pH 6.0 thorium hydrolysis products are detected, with little evidence for inner-sphere Tiron coordination. When the Th:L is changed to 1:2 at pH = 6.0, a stable oligomeric complex is formed that dominates the speciation for Th:L ratios up to 1.5. This complex is characterized by bidentate catechol and monodentate sulfonate ligation to Tiron along with oxygen bridging between Th4+ atoms and is consistent with the formation of the 2:3 Th:L polymeric species proposed from earlier work. At a Th:L ratio of 1:10, Th4+ complexation is dominated by bidentate catechol ligation and the formation of a monomeric Th(Tiron), species, where x 1 2. C1 Univ Calif Lawrence Livermore Natl Lab, Glenn T Seaborg Inst Transactinium Sci, Livermore, CA 94551 USA. RP Allen, PG (reprint author), Univ Calif Lawrence Livermore Natl Lab, Glenn T Seaborg Inst Transactinium Sci, POB 808,MS L-231, Livermore, CA 94551 USA. NR 34 TC 12 Z9 13 U1 1 U2 9 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 JUN 4 PY 2001 VL 40 IS 12 BP 2835 EP 2841 DI 10.1021/ic001223t PG 7 WC Chemistry, Inorganic & Nuclear SC Chemistry GA 439GE UT WOS:000169101800034 PM 11375702 ER PT J AU Hess, RF Abney, KD Burris, JL Hochheimer, HD Dorhout, PK AF Hess, RF Abney, KD Burris, JL Hochheimer, HD Dorhout, PK TI Synthesis and characterization of six new quaternary actinide thiophosphate compounds: Cs8U5(P3S10)(2)(PS4)(6), K10Th3(P2S7)(4)(PS4)(2), and A(5)An(PS4)(3), (A = K, Rb, Cs; An = U, Th) SO INORGANIC CHEMISTRY LA English DT Article ID VIBRATIONAL-SPECTRUM; CRYSTAL-STRUCTURE; FLUX COMPOSITION; SELENOPHOSPHATES; STABILIZATION; CHEMISTRY; COMPLEX; CHAINS AB Six new actinide metal thiophosphates have been synthesized by the reactive flux method and characterized by single-crystal X-ray diffraction: CS8U5(P3S10)(2)(PS4)(6) (I), K10Th3(P2S7)(4)(P-S4)(2) (II), K5U(PS4)(3) (III), K5Th(PS4)(3) (IV), Rb5Th(PS4)(3) (V), and CS5Th(PS4)(3) (VI). Compound I crystallizes in the monoclinic space group P2(1)/c with a 33.2897(1) Angstrom, b = 14.9295(1) Angstrom, c = 17.3528(2) Angstrom, beta = 115.478(1)degrees, Z = 8. Compound II crystallizes in the monoclinic space group C2/c with a = 32.8085(6) Angstrom, b = 9.8482(2) Angstrom, c = 27.2972(3) Angstrom, beta = 125.720(1)degrees, Z = 8. Compound III crystallizes in the monoclinic space group P2(1)/c with a = 14.6132(1) Angstrom, b = 17.0884(2) Angstrom, c = 9.7082(2) Angstrom, beta = 108.63(1)degrees, Z = 4. Compound IV crystallizes in the monoclinic space group P2(1)/c with 9.7436(1) Angstrom, b = 11.3894(2) Angstrom, c = 20.0163(3) Angstrom, beta = 90.041(1)degrees, Z = 4, as a pseudo-merohedrally twinned cell. Compound V crystallizes in the monoclinic space group P2(1)/c with a = 13.197(4) Angstrom, b = 9.997(4) Angstrom, c = 18.189(7) Angstrom, beta = 100.77(1)degrees Z = 4. Compound VI crystallizes in the monoclinic space group P2(1)/c with a = 13.5624(1) Angstrom, b = 10.3007(1) Angstrom, c = 18.6738(1) Angstrom, beta = 100.670(1)degrees, Z = 4. Optical band-gap measurements by diffuse reflectance show that compounds I and III contain tetravalent uranium as part of an extended electronic system. Thorium-containing compounds are large-gap materials. Raman spectroscopy on single crystals displays the vibrational characteristics expected for [PS4](3-), [P2S7](4-), and the new [P3S10](5-) building blocks. This new thiophosphate building block has not been observed except in the structure of the uranium-containing compound CS8U5(P3S10)(2)(PS4)(6). C1 Colorado State Univ, Dept Chem, Ft Collins, CO 80523 USA. Colorado State Univ, Dept Phys, Ft Collins, CO 80523 USA. Univ Calif Los Alamos Natl Lab, Div Chem, Los Alamos, NM 87545 USA. RP Dorhout, PK (reprint author), Colorado State Univ, Dept Chem, Ft Collins, CO 80523 USA. NR 31 TC 34 Z9 34 U1 1 U2 8 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 JUN 4 PY 2001 VL 40 IS 12 BP 2851 EP 2859 DI 10.1021/ic0014437 PG 9 WC Chemistry, Inorganic & Nuclear SC Chemistry GA 439GE UT WOS:000169101800036 PM 11375704 ER PT J AU Sanati, M Albers, RC Pinski, FJ AF Sanati, M Albers, RC Pinski, FJ TI omega-phase formation in NiAl and Ni2Al alloys SO JOURNAL OF PHYSICS-CONDENSED MATTER LA English DT Article ID ELECTRON-DIFFRACTION; BRILLOUIN-ZONE; SPECIAL POINTS; TRANSFORMATION; MICROSCOPY; ANOMALIES; SYSTEMS; BAND AB The phase stability of bcc-like NiAl and Ni2Al with respect to phase transformations into the omega phase is examined by first-principles, full-potential, linear muffin-tin orbital method (FPLMTO), band-structure calculations. In agreement with experiment we find that bcc-like NiAl is stable, whereas Ni2Al is unstable. We have also performed some calculations in slightly disordered phases, and find that the disordering tends to inhibit the transformation. This supports the suggestion that a combined displacive/ordering transformation mechanism is involved in the phase transformations of the Ni2Al system. Calculated lattice parameters and the degree of internal shuffling of atoms for the ordered Ni2Al phase were found to be in excellent agreement with the experiment. C1 Natl Renewable Energy Lab, Golden, CO 80401 USA. Univ Calif Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. Univ Cincinnati, Dept Phys, Cincinnati, OH 45221 USA. RP Sanati, M (reprint author), Natl Renewable Energy Lab, Golden, CO 80401 USA. NR 19 TC 7 Z9 10 U1 0 U2 3 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0953-8984 J9 J PHYS-CONDENS MAT JI J. Phys.-Condes. Matter PD JUN 4 PY 2001 VL 13 IS 22 BP 5387 EP 5398 DI 10.1088/0953-8984/13/22/328 PG 12 WC Physics, Condensed Matter SC Physics GA 442VJ UT WOS:000169305400040 ER PT J AU Harrison, N Singleton, J AF Harrison, N Singleton, J TI On the de Haas-van Alphen effect in inhomogeneous alloys SO JOURNAL OF PHYSICS-CONDENSED MATTER LA English DT Letter AB We show that Landau-level broadening in alloys occurs naturally as a consequence of random variations in the local quasiparticle density, without the need to consider a relaxation time. This approach predicts Lorentzian-broadened Landau levels similar to those derived by Dingle using the relaxation-time approximation. However, rather than being determined by a finite relaxation time tau, the Landau-level widths instead depend directly on the rate at which the de Haas-van Alphen frequency changes with alloy composition. The results are in good agreement with recent data from three very different alloy systems. C1 LANL, Natl High Magnet Field Lab, Los Alamos, NM 87545 USA. Univ Oxford, Dept Phys, Clarendon Lab, Oxford OX1 3PU, England. RP Harrison, N (reprint author), LANL, Natl High Magnet Field Lab, MS-E536, Los Alamos, NM 87545 USA. NR 20 TC 8 Z9 8 U1 0 U2 1 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0953-8984 J9 J PHYS-CONDENS MAT JI J. Phys.-Condes. Matter PD JUN 4 PY 2001 VL 13 IS 22 BP L463 EP L467 DI 10.1088/0953-8984/13/22/103 PG 5 WC Physics, Condensed Matter SC Physics GA 442VJ UT WOS:000169305400003 ER PT J AU Brandan, ME Menchaca-Rocha, A Trache, L Clark, HL Azhari, A Gagliardi, CA Lui, YW Tribble, RE Varner, RL Beene, JR Satchler, GR AF Brandan, ME Menchaca-Rocha, A Trache, L Clark, HL Azhari, A Gagliardi, CA Lui, YW Tribble, RE Varner, RL Beene, JR Satchler, GR TI Refractive elastic scattering of O-16 by C-12 at 300 MeV SO NUCLEAR PHYSICS A LA English DT Article DE O-16+C-12 elastic scattering at 300 MeV; airy structure; nuclear rainbow ID COUPLED-CHANNELS CALCULATIONS; O-16+C-12 SCATTERING; NUCLEAR-MATTER; FOLDING MODEL; POTENTIALS; ENERGIES; MEV/NUCLEON; O-16+O-16 AB The O-16 + C-12 elastic cross section at 300 MeV has been measured over a wide angular range, displaying the shoulder of a nuclear rainbow. The optical model analysis was done using a microscopic potential as well as phenomenological real potentials. The results of this study confirm the potential characteristics found in previous studies at higher and lower energies. (C) 2001 Elsevier Science B.V. All rights reserved. C1 Univ Nacl Autonoma Mexico, Inst Fis, Mexico City 01000, DF, Mexico. Texas A&M Univ, Inst Cyclotron, College Stn, TX 77845 USA. Oak Ridge Natl Lab, Div Phys, Oak Ridge, TN 37831 USA. Univ Tennessee, Dept Phys & Astron, Knoxville, TN 37996 USA. RP Univ Nacl Autonoma Mexico, Inst Fis, Apartado Postal 20-364, Mexico City 01000, DF, Mexico. EM brandan@servidor.unam.mx RI Brandan, Maria-Ester/K-9014-2012; Trache, Livius/M-6265-2016 OI Brandan, Maria-Ester/0000-0002-1165-3440; NR 22 TC 16 Z9 18 U1 1 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0375-9474 EI 1873-1554 J9 NUCL PHYS A JI Nucl. Phys. A PD JUN 4 PY 2001 VL 688 IS 3-4 BP 659 EP 668 DI 10.1016/S0375-9474(00)00588-1 PG 10 WC Physics, Nuclear SC Physics GA 434DG UT WOS:000168799400002 ER PT J AU Post, M Mosel, U AF Post, M Mosel, U TI Coupling of baryon resonances to the N omega channel SO NUCLEAR PHYSICS A LA English DT Article DE resonance decay; vector meson dominance; Breit-Wigner model; nuclear matter; omega spectral function ID DILEPTON EMISSION; PI(-)A REACTIONS; E(+)E(-) PAIRS; NUCLEAR-MATTER; VECTOR-MESONS; QUARK-MODEL; RHO-MESON; PHOTOPRODUCTION; ANISOTROPY; COLLISIONS AB We estimate the resonance couplings strength f(RN omega) and f(RN rho) from a Vector Meson Dominance (VMD) analysis. The isoscalar and isovector part of the photon coupling are obtained separately from helicity amplitudes. The reliability of this approach is tested by comparing VMD predictions fur f(RN rho) with values obtained from fitting the hadronic decay widths into N rho. A reasonable agreement is found, but VMD tends to underestimate the coupling constants. In order to confirm consistency with experimental data, we calculate the cross-sections for photon- and pion-induced reactions within a Breit-Wigner model. Finally, we study how the properties of omega mesons in nuclear matter are affected from the excitation of resonance-hole loops. For an omega at rest, we find a broadening of about 40 MeV, while at higher momenta the effect of resonance excitations is reduced. (C) 2001 Elsevier Science B.V. All rights reserved. C1 Univ Giessen, Inst Theoret Phys, D-35392 Giessen, Germany. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Nucl Sci, Berkeley, CA 94720 USA. RP Post, M (reprint author), Univ Giessen, Inst Theoret Phys, D-35392 Giessen, Germany. RI Mosel, Ulrich/E-2565-2012 NR 28 TC 40 Z9 40 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0375-9474 J9 NUCL PHYS A JI Nucl. Phys. A PD JUN 4 PY 2001 VL 688 IS 3-4 BP 808 EP 822 DI 10.1016/S0375-9474(00)00583-2 PG 15 WC Physics, Nuclear SC Physics GA 434DG UT WOS:000168799400009 ER PT J AU Ping, JL Wang, F Goldman, T AF Ping, JL Wang, F Goldman, T TI Dynamical calculation of d* mass and NN decay width in the quark delocalization, color screening model SO NUCLEAR PHYSICS A LA English DT Article DE mass, decay; Quark, quark model ID INTERMEDIATE RANGE ATTRACTION; DOUBLE-CHARGE-EXCHANGE; TOTAL CROSS-SECTION; HYPERFINE INTERACTIONS; LOW ENERGIES; FRACTIONAL PARENTAGE; DIBARYON; BARYONS; STATES; RESONANCE AB The mass estimate of the d*(IJ(P) = 03(+)) dibaryon is improved by a dynamical calculation in the quark delocalization, color screening model. The partial decay width of d* into an NN D-wave stare is also obtained. The mass obtained is slightly larger than that obtained in adiabatic calculations, due to the anharmonicity of the effective potential between two Delta 's. The value of the width obtained due to tenser one-gluon exchange is about 5 MeV, comparable in magnitude to earlier results found using pion exchange. (C) 2001 Elsevier Science B.V. All rights reserved. C1 Univ Calif Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. Nanjing Univ, Dept Phys, Nanjing 210097, Peoples R China. Nanjing Univ, Ctr Theoret Phys, Nanjing 210093, Peoples R China. Nanjing Univ, Dept Phys, Nanjing 210093, Peoples R China. RP Goldman, T (reprint author), Univ Calif Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. NR 53 TC 34 Z9 35 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0375-9474 J9 NUCL PHYS A JI Nucl. Phys. A PD JUN 4 PY 2001 VL 688 IS 3-4 BP 871 EP 881 DI 10.1016/S0375-9474(00)00593-5 PG 11 WC Physics, Nuclear SC Physics GA 434DG UT WOS:000168799400012 ER PT J AU Beane, SR Bedaque, PF Savage, MJ AF Beane, SR Bedaque, PF Savage, MJ TI Renormalization group improved gap equation for color superconductors SO NUCLEAR PHYSICS A LA English DT Article ID FINITE BARYON DENSITY; SHORT-RANGE INTERACTIONS; DIQUARK CONDENSATION; QUARK MATTER; LATTICE APPROACH; FLAVOR LOCKING; QCD; MODEL; TEMPERATURE; INSTANTONS AB The renormalization group is used to resum leading logarithmic contributions of the form alpha (n+1)(s)beta (n)(0)log(n)(Delta/mu) to the gap equation appropriate for high-density QCD. The scale dependence of the strong coupling constant alpha (s) increases the gap by a factor of exp(33/16(pi (2)/4 - 1)) similar to 20 in the small coupling limit. (C) 2001 Elsevier Science B.V. All rights reserved. C1 Univ Washington, Dept Phys, Seattle, WA 98195 USA. Univ Washington, Inst Nucl Theory, Seattle, WA 98195 USA. Jefferson Lab, Newport News, VA 23606 USA. RP Univ Washington, Dept Phys, Seattle, WA 98195 USA. EM sbeane@phys.washington.edu; bedaque@phys.washington.edu; savage@phys.washington.edu NR 93 TC 12 Z9 12 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0375-9474 EI 1873-1554 J9 NUCL PHYS A JI Nucl. Phys. A PD JUN 4 PY 2001 VL 688 IS 3-4 BP 931 EP 938 DI 10.1016/S0375-9474(00)00595-9 PG 8 WC Physics, Nuclear SC Physics GA 434DG UT WOS:000168799400016 ER PT J AU Boer, D AF Boer, D TI Sudakov suppression in azimuthal spin asymmetries SO NUCLEAR PHYSICS B LA English DT Article ID TRANSVERSE-MOMENTUM DISTRIBUTIONS; DRELL-YAN PROCESS; QUARK FRAGMENTATION FUNCTION; DEEPLY INELASTIC-SCATTERING; BOSON PRODUCTION; E(+)E(-) ANNIHILATION; PARTON DISTRIBUTION; GLUON RESUMMATION; HADRON-PRODUCTION; CROSS-SECTION AB It is shown that transverse momentum dependent azimuthal spin asymmetries suffer from suppression due to Sudakov factors, in the region where the transverse momentum is much smaller than the large energy scale Q(2). The size and Q(2) dependence of this suppression are studied numerically for two, such asymmetries, both arising due to the Collins effect. General features are discussed of how the fall-off with Q(2) is affected by the nonperturbative Sudakov factor and by the transverse momentum weights and angular dependences that appear in different asymmetries. For a subset of asymmetries the asymptotic Q(2) behavior is calculated analytically, providing an upper bound for the decrease with energy of other asymmetries. The effect of Sudakov factors on the transverse momentum distributions is found to be very significant already at present-day collider energies. Therefore, it is essential to rake into account Sudakov factors in transverse momentum dependent azimuth;ll spin asymmetries, (C) 2001 Elsevier Science B.V. All rights reserved. C1 Brookhaven Natl Lab, Res Ctr, BNL, RIKEN, Upton, NY 11973 USA. RP Boer, D (reprint author), Brookhaven Natl Lab, Res Ctr, BNL, RIKEN, Upton, NY 11973 USA. RI Boer, Daniel/B-3493-2015 OI Boer, Daniel/0000-0003-0985-4662 NR 39 TC 68 Z9 68 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0550-3213 J9 NUCL PHYS B JI Nucl. Phys. B PD JUN 4 PY 2001 VL 603 IS 1-2 BP 195 EP 217 DI 10.1016/S0550-3213(01)00156-0 PG 23 WC Physics, Particles & Fields SC Physics GA 445HE UT WOS:000169451400006 ER PT J AU Datta-Gupta, A Vasco, DW AF Datta-Gupta, A Vasco, DW TI Production tomography merges geophysics with reservoir engineering SO OIL & GAS JOURNAL LA English DT Article C1 Texas A&M Univ, College Stn, TX 77843 USA. Berkeley Lab, Berkeley, CA USA. RP Datta-Gupta, A (reprint author), Texas A&M Univ, College Stn, TX 77843 USA. RI Vasco, Donald/I-3167-2016 OI Vasco, Donald/0000-0003-1210-8628 NR 13 TC 1 Z9 2 U1 0 U2 1 PU PENNWELL PUBL CO ENERGY GROUP PI TULSA PA 1421 S SHERIDAN RD PO BOX 1260, TULSA, OK 74101 USA SN 0030-1388 J9 OIL GAS J JI Oil Gas J. PD JUN 4 PY 2001 VL 99 IS 23 BP 75 EP 81 PG 7 WC Energy & Fuels; Engineering, Petroleum SC Energy & Fuels; Engineering GA 439LJ UT WOS:000169118100020 ER PT J AU Boettcher, S Percus, AG AF Boettcher, S Percus, AG TI Optimization with extremal dynamics SO PHYSICAL REVIEW LETTERS LA English DT Article ID SELF-ORGANIZED CRITICALITY; ISING SPIN-GLASS; COMPUTATIONAL-COMPLEXITY; MODELS; EVOLUTION AB We explore a new general-purpose heuristic for finding high-quality solutions to hard discrete optimization problems. The method, called extremal optimization, is inspired by self-organized criticality, a concept introduced to describe emergent complexity in physical systems. Extremal optimization successively updates extremely undesirable Variables of a single suboptimal solution, assigning them new, random values. Large fluctuations ensue, efficiently exploring many local optima. We use extremal optimization to elucidate the phase transition in the 3-coloring problem, and we provide independent confirmation of previously reported extrapolations for the ground-state energy of +/-J spin glasses in d = 3 and 4. C1 Emory Univ, Dept Phys, Atlanta, GA 30322 USA. Univ Calif Los Alamos Natl Lab, Comp & Computat Sci Div, Los Alamos, NM 87545 USA. RP Boettcher, S (reprint author), Emory Univ, Dept Phys, Atlanta, GA 30322 USA. RI Boettcher, Stefan/G-2640-2010 OI Boettcher, Stefan/0000-0003-1273-6771 NR 31 TC 183 Z9 187 U1 3 U2 15 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 JUN 4 PY 2001 VL 86 IS 23 BP 5211 EP 5214 DI 10.1103/PhysRevLett.86.5211 PG 4 WC Physics, Multidisciplinary SC Physics GA 439MW UT WOS:000169121500001 PM 11384460 ER PT J AU Kushnirenko, A Alkhazov, G Atamantchouk, AG Balatz, MY Bondar, NF Cooper, PS Dauwe, LJ Davidenko, GV Dersch, U Dolgolenko, AG Dzyubenko, GB Edelstein, R Emediato, L Endler, AMF Engelfried, J Eschrich, I Escobar, CO Evdokimov, AV Filimonov, IS Garcia, FG Gaspero, M Giller, I Golovtsov, VL Gouffon, P Gulmez, E He, KL Iori, M Jun, SY Kaya, M Kilmer, J Kim, VT Kochenda, LM Konorov, I Kozhevnikov, AP Krivshich, AG Kruger, H Kubantsev, MA Kubarovsky, VP Kulyavtsev, AI Kuropatkin, NP Kurshetsov, VE Kwan, S Lach, J Lamberto, A Landsberg, LG Larin, I Leikin, EM Li, YS Luksys, M Lungov, T Maleev, VP Mao, D Mao, CS Mao, ZL Mathew, P Mattson, M Matveev, V McCliment, E Moinester, MA Molchanov, VV Morelos, A Nelson, KD Nemitkin, AV Neoustroev, PV Newsom, C Nilov, AP Nurushev, SB Ocherashvili, A Onel, Y Ozel, E Ozkonrcuklu, S Penzo, A Petrenko, SV Pogodin, P Procario, M Prutskoi, VA Ramberg, E Rappazzo, GF Razmyslovich, BV Rud, VI Russ, J Schiavon, P Simon, J Sitnikov, AI Skow, D Smith, VJ Srivastava, M Steiner, V Stepanov, V Stutte, L Svoiski, M Terentyev, NK Thomas, GP Uvarov, LN Vasiliev, AN Vavilov, DV Verebryusov, VS Victorov, VA Vishnyakov, VE Vorobyov, AA Vorwalter, K You, J Zhao, WH Zheng, SC Zukanovich-Funchal, R AF Kushnirenko, A Alkhazov, G Atamantchouk, AG Balatz, MY Bondar, NF Cooper, PS Dauwe, LJ Davidenko, GV Dersch, U Dolgolenko, AG Dzyubenko, GB Edelstein, R Emediato, L Endler, AMF Engelfried, J Eschrich, I Escobar, CO Evdokimov, AV Filimonov, IS Garcia, FG Gaspero, M Giller, I Golovtsov, VL Gouffon, P Gulmez, E He, KL Iori, M Jun, SY Kaya, M Kilmer, J Kim, VT Kochenda, LM Konorov, I Kozhevnikov, AP Krivshich, AG Kruger, H Kubantsev, MA Kubarovsky, VP Kulyavtsev, AI Kuropatkin, NP Kurshetsov, VE Kwan, S Lach, J Lamberto, A Landsberg, LG Larin, I Leikin, EM Li, YS Luksys, M Lungov, T Maleev, VP Mao, D Mao, CS Mao, ZL Mathew, P Mattson, M Matveev, V McCliment, E Moinester, MA Molchanov, VV Morelos, A Nelson, KD Nemitkin, AV Neoustroev, PV Newsom, C Nilov, AP Nurushev, SB Ocherashvili, A Onel, Y Ozel, E Ozkonrcuklu, S Penzo, A Petrenko, SV Pogodin, P Procario, M Prutskoi, VA Ramberg, E Rappazzo, GF Razmyslovich, BV Rud, VI Russ, J Schiavon, P Simon, J Sitnikov, AI Skow, D Smith, VJ Srivastava, M Steiner, V Stepanov, V Stutte, L Svoiski, M Terentyev, NK Thomas, GP Uvarov, LN Vasiliev, AN Vavilov, DV Verebryusov, VS Victorov, VA Vishnyakov, VE Vorobyov, AA Vorwalter, K You, J Zhao, WH Zheng, SC Zukanovich-Funchal, R CA SELEX Collaboration TI Precision measurements of the Lambda(+)(c) and D-0 lifetimes SO PHYSICAL REVIEW LETTERS LA English DT Article ID MESON LIFETIMES; DECAYS AB We report new precision measurements of the lifetimes of the A(c)(+) and D-0 from SELEX, the charm hadroproduction experiment at Fermilab. Based upon 1630 A(c)(+) and 10210 D-0 decays we observe lifetimes of tau [A(c)(+)] = 198.1 +/- 7.0 +/- 5.6 fs and tau [D-0] = 407.9 +/- 6.0 +/- 4.3 fs. C1 Carnegie Mellon Univ, Pittsburgh, PA 15213 USA. Ball State Univ, Muncie, IN 47306 USA. Bogazici Univ, TR-80815 Bebek, Turkey. Ctr Brasileiro Pesquisas Fis, Rio De Janeiro, Brazil. Fermilab, Batavia, IL 60510 USA. Inst High Energy Phys, Protvino, Russia. Inst High Energy Phys, Beijing 100039, Peoples R China. Inst Theoret & Expt Phys, Moscow 117259, Russia. Max Planck Inst Kernphys, D-69117 Heidelberg, Germany. Moscow State Univ, Moscow, Russia. Petersburg Nucl Phys Inst, St Petersburg, Russia. Tel Aviv Univ, IL-69978 Ramat Aviv, Israel. Univ Autonoma San Luis Potosi, San Luis Potosi, Mexico. Univ Fed Paraiba, BR-58059900 Joao Pessoa, Paraiba, Brazil. Univ Bristol, Bristol BS8 1TL, Avon, England. Univ Iowa, Iowa City, IA 52242 USA. Univ Michigan, Flint, MI 48502 USA. Univ Rome La Sapienza, Rome, Italy. Ist Nazl Fis Nucl, Rome, Italy. Univ Sao Paulo, Sao Paulo, Brazil. Univ Trieste, Trieste, Italy. Ist Nazl Fis Nucl, Trieste, Italy. RP Kushnirenko, A (reprint author), Carnegie Mellon Univ, Pittsburgh, PA 15213 USA. RI Zukanovich Funchal, Renata/C-5829-2013; Russ, James/P-3092-2014; Gulmez, Erhan/P-9518-2015; Gouffon, Philippe/I-4549-2012; Maleev, Victor/R-4140-2016; OI Zukanovich Funchal, Renata/0000-0001-6749-0022; Russ, James/0000-0001-9856-9155; Gulmez, Erhan/0000-0002-6353-518X; Gouffon, Philippe/0000-0001-7511-4115; Jun, Soon Yung/0000-0003-3370-6109 NR 11 TC 27 Z9 27 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 JUN 4 PY 2001 VL 86 IS 23 BP 5243 EP 5246 DI 10.1103/PhysRevLett.86.5243 PG 4 WC Physics, Multidisciplinary SC Physics GA 439MW UT WOS:000169121500009 PM 11384468 ER PT J AU Haxton, WC Liu, CP Ramsey-Musolf, MJ AF Haxton, WC Liu, CP Ramsey-Musolf, MJ TI Anapole moment and other constraints on the strangeness conserving hadronic weak interaction SO PHYSICAL REVIEW LETTERS LA English DT Article ID ELECTRON NUCLEUS INTERACTION; PARITY NONCONSERVATION; NEUTRAL CURRENT; SCATTERING AB Standard analyses of low-energy NN and nuclear parity-violating observables have been based on a pi-, rho-, and omega -exchange model capable of describing all five independent s-p partial waves. Here a parallel analysis is performed for the one-body, exchange-current, and nuclear polarization contributions to the anapole moments of Cs-133 and Tl-205. The resulting constraints are not consistent; though there remains some degree of uncertainty in the nuclear structure analysis of the atomic moments. C1 Univ Washington, Inst Nucl Theory, Seattle, WA 98195 USA. Univ Washington, Dept Phys, Seattle, WA 98195 USA. CALTECH, Kellogg Radiat Lab, Pasadena, CA 91125 USA. Univ Connecticut, Dept Phys, Storrs, CT 06269 USA. Thomas Jefferson Natl Accelerator Facil, Theory Grp, Newport News, VA 23606 USA. RP Haxton, WC (reprint author), Univ Washington, Inst Nucl Theory, Box 351550, Seattle, WA 98195 USA. NR 22 TC 40 Z9 40 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD JUN 4 PY 2001 VL 86 IS 23 BP 5247 EP 5250 DI 10.1103/PhysRevLett.86.5247 PG 4 WC Physics, Multidisciplinary SC Physics GA 439MW UT WOS:000169121500010 PM 11384469 ER PT J AU Knickelbein, MB AF Knickelbein, MB TI Experimental observation of superparamagnetism in manganese clusters SO PHYSICAL REVIEW LETTERS LA English DT Article ID ELECTRON-SPIN-RESONANCE; NICKEL CLUSTERS; MAGNETIC-PROPERTIES; MN CLUSTERS; FREE COBALT; TRANSITION; METAL; BEAMS; IRON; NANOMAGNETS AB A molecular beam of manganese clusters, Mn-n (n = 11-99), produced at 68 K is deflected toward high field by a gradient field magnet. These results indicate that Mn, clusters in this size range are superparamagnetic species whose intrinsic moments can be determined within the framework of the Langevin model of paramagnetism. Local minima in per-atom magnetic moments are observed for Mn-13 and Mn-19, suggestive of an icosahedral growth sequence for the smaller size range. For larger clusters, broad oscillations in the per-atom moments are observed, with a minimum near Mn32-37 and a maximum around Mn50-56. C1 Argonne Natl Lab, Div Chem, Argonne, IL 60439 USA. RP Knickelbein, MB (reprint author), Argonne Natl Lab, Div Chem, 9700 S Cass Ave, Argonne, IL 60439 USA. NR 29 TC 178 Z9 180 U1 4 U2 29 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 JUN 4 PY 2001 VL 86 IS 23 BP 5255 EP 5257 DI 10.1103/PhysRevLett.86.5255 PG 3 WC Physics, Multidisciplinary SC Physics GA 439MW UT WOS:000169121500012 PM 11384471 ER PT J AU Stupakov, GV Zolotorev, MS AF Stupakov, GV Zolotorev, MS TI Ponderomotive laser acceleration and focusing in vacuum for generation of attosecond electron bunches SO PHYSICAL REVIEW LETTERS LA English DT Article ID INTENSITY LASER; SCATTERING AB A novel approach for the generation of ultrabright attosecond electron bunches is proposed, based on acceleration in vacuum, by a short laser pulse. The laser-pulse profile is tailored such that the electrons are both focused and accelerated by the ponderomotive force of the light. Using time-averaged equations of motion, analytical criteria for optimal regime of acceleration are found. It is shown that for realistic laser parameters, a beam with up to 10(6) particles and normalized transverse and longitudinal emittances < 10(-8) m can be produced. C1 Stanford Univ, Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. Lawrence Berkeley Natl Lab, Ctr Beam Phys, Berkeley, CA 94720 USA. RP Stupakov, GV (reprint author), Stanford Univ, Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. NR 13 TC 131 Z9 132 U1 1 U2 11 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 JUN 4 PY 2001 VL 86 IS 23 BP 5274 EP 5277 DI 10.1103/PhysRevLett.86.5274 PG 4 WC Physics, Multidisciplinary SC Physics GA 439MW UT WOS:000169121500017 PM 11384476 ER PT J AU Son, KA Kim, HI Houston, JE AF Son, KA Kim, HI Houston, JE TI Role of stress on charge transfer through self-assembled alkanethiol monolayers on Au SO PHYSICAL REVIEW LETTERS LA English DT Article ID SCANNING-TUNNELING-MICROSCOPY; ORGANIC-MOLECULES; FORCE MICROSCOPY; AU(111) AB We have studied charge transfer through alkanethiol molecules self-assembled on Au(lll) substrates using interfacial force microscopy. Simultaneous measurement of the tip-substrate current and the normal interfacial force reveals the critical role of tip-film contact. Measurable currents are seen only for tip-applied stresses above about 20 MPa, after which the current rises exponential with stress. We suggest that charge transfer results from stress-induced band-gap states near the Fermi level in these normally highly insulating molecular films. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Son, KA (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. NR 24 TC 54 Z9 54 U1 1 U2 5 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 JUN 4 PY 2001 VL 86 IS 23 BP 5357 EP 5360 DI 10.1103/PhysRevLett.86.5357 PG 4 WC Physics, Multidisciplinary SC Physics GA 439MW UT WOS:000169121500038 PM 11384497 ER PT J AU Coldea, R Hayden, SM Aeppli, G Perring, TG Frost, CD Mason, TE Cheong, SW Fisk, Z AF Coldea, R Hayden, SM Aeppli, G Perring, TG Frost, CD Mason, TE Cheong, SW Fisk, Z TI Spin waves and electronic interactions in La2CuO4 SO PHYSICAL REVIEW LETTERS LA English DT Article ID HIGH-ENERGY SPIN; HEISENBERG-ANTIFERROMAGNET; SQUARE-LATTICE; CHARGE EXCITATIONS; COPPER OXIDES; EXCHANGE; MODEL; SUPERCONDUCTORS; RENORMALIZATION; TEMPERATURE AB The magnetic excitations of the square-lattice spin-1/2 antiferromagnet and high-ir, parent compound La2CuO4 are determined using high-resolution inelastic neutron scattering. Sharp spin waves with absolute intensities in agreement with theory including quantum corrections are found throughout the;Brillouin zone. The observed dispersion relation shows evidence for substantial interactions beyond the nearest-neighbor Heisenberg term which can be understood in terms of a cyclic or ring exchange due to the; strong hybridization path around the CU4O4 square plaquettes. C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. Rutherford Appleton Lab, ISIS Facil, Didcot OX11 0QX, Oxon, England. Univ Bristol, HH Wills Phys Lab, Bristol BS8 1TL, Avon, England. NEC Res Inst, Princeton, NJ 08540 USA. Lucent Technol, Murray Hill, NJ 07974 USA. Florida State Univ, Dept Phys, Tallahassee, FL 32306 USA. RP Coldea, R (reprint author), Oak Ridge Natl Lab, POB 2008, Oak Ridge, TN 37831 USA. RI Hayden, Stephen/F-4162-2011; Mason, Thomas/M-5809-2014 OI Hayden, Stephen/0000-0002-3209-027X; Mason, Thomas/0000-0003-1880-3971 NR 31 TC 378 Z9 380 U1 8 U2 37 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 JUN 4 PY 2001 VL 86 IS 23 BP 5377 EP 5380 DI 10.1103/PhysRevLett.86.5377 PG 4 WC Physics, Multidisciplinary SC Physics GA 439MW UT WOS:000169121500043 PM 11384502 ER PT J AU Zhu, W Seve, L Sears, R Sinkovic, B Parkin, SSP AF Zhu, W Seve, L Sears, R Sinkovic, B Parkin, SSP TI Field cooling induced changes in the antiferromagnetic structure of NiO films SO PHYSICAL REVIEW LETTERS LA English DT Article ID X-RAY DICHROISM; EXCHANGE BIAS; MAGNETIC DICHROISM; SPIN STRUCTURE; BILAYERS; MODEL; ANISOTROPY; FE; INTERFACES; MOMENTS AB The magnetic anisotropy in antiferromagnetic 500 Angstrom thick NiO films, before and after the establishment of an exchange bias field with Co84Fe16 ferromagnetic layers, was measured using magnetic linear dichroism in soft x-ray absorption. Both < 111 > textured NiO and untextured NiO films show exchange-bias induced in-plane magnetic anisotropy of nearly equal magnitude and with the Ni moment axis being nearly parallel to the exchange bias field direction. These results represent the first observation of the key step in the exchange biasing process, namely, repopulation of the antiferromagnetic domains whose magnetization axis is closest to the exchange bias field direction. C1 Univ Connecticut, Dept Phys, Storrs, CT 06269 USA. Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. IBM Corp, Almaden Res Ctr, San Jose, CA 95120 USA. RP Zhu, W (reprint author), Univ Connecticut, Dept Phys, 2152 Hillside Rd, Storrs, CT 06269 USA. RI Parkin, Stuart/D-2521-2012 NR 23 TC 78 Z9 79 U1 4 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 JUN 4 PY 2001 VL 86 IS 23 BP 5389 EP 5392 DI 10.1103/PhysRevLett.86.5389 PG 4 WC Physics, Multidisciplinary SC Physics GA 439MW UT WOS:000169121500046 PM 11384505 ER PT J AU Setlow, RB AF Setlow, RB TI Human cancer: etiologic agents/dose responses/DNA repair/cellular and animal models SO MUTATION RESEARCH-FUNDAMENTAL AND MOLECULAR MECHANISMS OF MUTAGENESIS LA English DT Review DE aging; caloric restriction; endogenous damage; exogenous damage; mutations ID DNA-REPAIR METHYLTRANSFERASE; NONMELANOMA SKIN-CANCER; XERODERMA-PIGMENTOSUM; KNOCKOUT MICE; INDUCED TUMORIGENESIS; SPONTANEOUS MUTATION; HUMAN-LYMPHOCYTES; UNITED-STATES; MELANOMA; DAMAGE AB The observation of cancer in an individual does not identify the causative agent(s). However, epidemiological data on populations do indicate that a large fraction of human cancers are associated with lifestyle/diet. Such studies may also help identify the etiologic agents but unless there are good dose-response data for humans and/or animal models, the probability of identifying the agent is not high. Cancers may result from endogenous reactions, such as oxidations or from exogenous agents, such as tobacco smoke (lung cancer), sunlight exposure (skin cancer), aflatoxin (liver cancer), and relatively high doses of ionizing radiations (many types of cancers). Many carcinogenic chemicals have been identified in the workplace but, they usually do not affect the overall population. Most cancer causing agents affect cellular DNA and change its coding specificity and act as cancer initiators. The repair of DNA damage ameliorates most of these endogenous and exogenous changes. The important role of DNA repair in controlling the induction of human cancer came from the observation that individuals with the skin cancer-susceptible, human disease xeroderma pigmentosum (XP) were defective in nucleotide excision repair. Endogenous DNA damages are usually damages to individual bases and are usually repaired by systems of glycosylases and endonucleases. It should be useful to investigate the rates of appearance of tumors in normal mice and in mice knocked out for specific repair enzymes because such mice could be used to test the roles of diet and caloric input in affecting particular types of endogenous damages Published by Elsevier Science B.V. C1 Brookhaven Natl Lab, Dept Biol, Upton, NY 11973 USA. RP Setlow, RB (reprint author), Brookhaven Natl Lab, Dept Biol, Upton, NY 11973 USA. EM setlow@bnl.gov NR 43 TC 13 Z9 14 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0027-5107 J9 MUTAT RES-FUND MOL M JI Mutat. Res.-Fundam. Mol. Mech. Mutagen. PD JUN 2 PY 2001 VL 477 IS 1-2 SI SI BP 1 EP 6 DI 10.1016/S0027-5107(01)00090-2 PG 6 WC Biotechnology & Applied Microbiology; Genetics & Heredity; Toxicology SC Biotechnology & Applied Microbiology; Genetics & Heredity; Toxicology GA 441WQ UT WOS:000169252900001 PM 11376681 ER PT J AU Thompson, LH Schild, D AF Thompson, LH Schild, D TI Homologous recombinational repair of DNA ensures mammalian chromosome stability SO MUTATION RESEARCH-FUNDAMENTAL AND MOLECULAR MECHANISMS OF MUTAGENESIS LA English DT Review DE homologous recombinational repair; DNA; chromosome ID DOUBLE-STRAND BREAK; HUMAN RAD51 PROTEIN; SISTER-CHROMATID EXCHANGE; CELL-CYCLE CHECKPOINTS; HUMAN-TUMOR-CELLS; ATAXIA-TELANGIECTASIA FIBROBLASTS; ATM-DEPENDENT PHOSPHORYLATION; EARLY EMBRYONIC LETHALITY; ABL TYROSINE KINASE; HAMSTER OVARY CELLS AB The process of homologous recombinational repair (HRR) is a major DNA repair pathway that acts on double-strand breaks and interstrand crosslinks, and probably to a lesser extent on other kinds of DNA damage. HRR provides a mechanism for the error-fret removal of damage present in DNA that has replicated (S and G2 phases). Thus, HRR acts in a critical way, in coordination with the S and G2 checkpoint machinery, to eliminate chromosomal breaks before the cell division occurs. Many of the human HRR genes, including five Rad51 paralogs, have been identified, and knockout mutants for most of these genes are available in chicken DT40 cells. In the mouse, most of the knockout mutations cause embryonic lethality. The Brca1 and Brca2 breast cancer susceptibility genes appear to be intimately involved in HRR, but the mechanistic basis is unknown. Biochemical studies with purified proteins and cell extracts, combined with cytological studies of nuclear foci, have begun to establish an outline of the steps in mammalian HRR. This pathway is subject to complex regulatory controls from the checkpoint machinery and other processes, and there is increasing evidence that loss of HRR gene function can contribute to tumor development. This review article is meant to be an update of our previous review [Biochimie 81 (1999) 87]. Published by Elsevier Science B.V. C1 Lawrence Livermore Natl Lab, Biol & Biotechnol Res Program, Livermore, CA 94551 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Life Sci, Berkeley, CA 94720 USA. RP Thompson, LH (reprint author), Lawrence Livermore Natl Lab, Biol & Biotechnol Res Program, L-441,POB 808, Livermore, CA 94551 USA. EM thompsonl4@llnl.gov FU NIGMS NIH HHS [GM30990] NR 241 TC 302 Z9 306 U1 2 U2 12 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0027-5107 J9 MUTAT RES-FUND MOL M JI Mutat. Res.-Fundam. Mol. Mech. Mutagen. PD JUN 2 PY 2001 VL 477 IS 1-2 SI SI BP 131 EP 153 DI 10.1016/S0027-5107(01)00115-4 PG 23 WC Biotechnology & Applied Microbiology; Genetics & Heredity; Toxicology SC Biotechnology & Applied Microbiology; Genetics & Heredity; Toxicology GA 441WQ UT WOS:000169252900015 PM 11376695 ER PT J AU Gustafsson, T Klintenberg, M Derenzo, SE Weber, MJ Thomas, JO AF Gustafsson, T Klintenberg, M Derenzo, SE Weber, MJ Thomas, JO TI Lu2SiO5 by single-crystal X-ray and neutron diffraction SO ACTA CRYSTALLOGRAPHICA SECTION C-CRYSTAL STRUCTURE COMMUNICATIONS LA English DT Article AB The structure of dilutetium silicon pentaoxide, Lu2SiO5, has isolated ionic SiO4 tetrahedral units and non-Si-bonded O atoms in distorted OLu4 tetrahedra. The OLu4 tetrahedra form edge-sharing infinite chains and double O2Lu6 tetrahedra along the c axis. The edge-sharing chains are connected to the O2Lu6 double tetrahedra by isolated SiO4 units. The structure has been determined by neutron diffraction. C1 Uppsala Univ, Angstrom Lab, SE-75121 Uppsala, Sweden. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Gustafsson, T (reprint author), Uppsala Univ, Angstrom Lab, Box 538, SE-75121 Uppsala, Sweden. FU NCI NIH HHS [R01-CA48002] NR 12 TC 55 Z9 56 U1 1 U2 7 PU MUNKSGAARD INT PUBL LTD PI COPENHAGEN PA 35 NORRE SOGADE, PO BOX 2148, DK-1016 COPENHAGEN, DENMARK SN 0108-2701 J9 ACTA CRYSTALLOGR C JI Acta Crystallogr. Sect. C-Cryst. Struct. Commun. PD JUN PY 2001 VL 57 BP 668 EP 669 DI 10.1107/S0108270101005352 PN 6 PG 2 WC Chemistry, Multidisciplinary; Crystallography SC Chemistry; Crystallography GA 446UN UT WOS:000169532700003 PM 11408663 ER PT J AU Gonzalez, A Larsson, G Persson, R Cedergren-Zeppezauer, E AF Gonzalez, A Larsson, G Persson, R Cedergren-Zeppezauer, E TI Atomic resolution structure of Escherichia coli dUTPase determined ab initio SO ACTA CRYSTALLOGRAPHICA SECTION D-BIOLOGICAL CRYSTALLOGRAPHY LA English DT Article ID FELINE IMMUNODEFICIENCY VIRUS; INFECTIOUS-ANEMIA VIRUS; CRYSTAL-STRUCTURE; MACROMOLECULAR STRUCTURES; STRUCTURE REFINEMENT; PROTEIN; PYROPHOSPHATASE; COMPLEX; CRYSTALLOGRAPHY; BINDING AB Cryocooled crystals of a mercury complex of Escherichia coli dUTPase diffract to atomic resolution. Data to 1.05 Angstrom resolution were collected from a derivative crystal and the structure model was derived from a Fourier map with phases calculated from the coordinates of the Hg atom (one site per subunit of the trimeric enzyme) using the program ARP/ wARP. After refinement with anisotropic temperature factors a highly accurate model of the bacterial dUTPase was obtained. Data to 1.45 Angstrom from a native crystal were also collected and the 100 K structures were compared. Inspection of the refined models reveals that a large part of the dUTPase remains rather mobile upon freezing, with 14% of the main chain being totally disordered and with numerous side chains containing disordered atoms in multiple discrete conformations. A large number of those residues surround the active-site cavity. Two glycerol molecules (the cryosolvent) occupy the deoxyribose-binding site. Comparison between the native enzyme and the mercury complex shows that the active site is not adversely affected by the binding of mercury. An unexpected effect seems to be a stabilization of the crystal lattice by means of long-range interactions, making derivatization a potentially useful tool for further studies of inhibitor- substrate-analogue complexes of this protein at very high resolution. C1 European Mol Biol Lab, Hamburg Outstn, D-22603 Hamburg, Germany. Univ Lund, Dept Biochem, Ctr Chem & Chem Engn, S-22100 Lund, Sweden. RP Gonzalez, A (reprint author), Stanford Synchrotron Radiat Lab, 2575 Sand Hill Rd,MS 99, Menlo Park, CA 94025 USA. NR 46 TC 25 Z9 26 U1 0 U2 0 PU MUNKSGAARD INT PUBL LTD PI COPENHAGEN PA 35 NORRE SOGADE, PO BOX 2148, DK-1016 COPENHAGEN, DENMARK SN 0907-4449 J9 ACTA CRYSTALLOGR D JI Acta Crystallogr. Sect. D-Biol. Crystallogr. PD JUN PY 2001 VL 57 BP 767 EP 774 DI 10.1107/S0907444901004255 PN 6 PG 8 WC Biochemical Research Methods; Biochemistry & Molecular Biology; Biophysics; Crystallography SC Biochemistry & Molecular Biology; Biophysics; Crystallography GA 446UV UT WOS:000169533300001 PM 11375495 ER PT J AU Otagiri, M Kurisu, G Swaminathan, S Ui, S Yoneda, S Ohkuma, M Kudo, T Kusunoki, M AF Otagiri, M Kurisu, G Swaminathan, S Ui, S Yoneda, S Ohkuma, M Kudo, T Kusunoki, M TI Crystallization and preliminary X-ray studies of meso-2,3-butanediol dehydrogenase from Klebsiella pneumoniae IAM1063 SO ACTA CRYSTALLOGRAPHICA SECTION D-BIOLOGICAL CRYSTALLOGRAPHY LA English DT Article ID CRYSTAL-STRUCTURE; ANGSTROM RESOLUTION; 17-BETA-HYDROXYSTEROID DEHYDROGENASE; 2,3-BUTANEDIOL STEREOISOMERS; ESCHERICHIA-COLI; TERNARY COMPLEX; REDUCTASE; FAMILY; MECHANISM; SEQUENCE AB Meso-2,3-butanediol dehydrogenase (meso-BDH) has been crystallized and preliminary X-ray crystallographic characterization of meso-BDH crystals has been performed. Single crystals of meso-BDH were prepared in two forms by the hanging-drop vapour-diffusion method using polyethylene glycol as a precipitant. Form I crystals belong to space group C2, with unit-cell parameters a = 215.5, b = 79.4, c = 134.8 Angstrom, beta = 98.22 degrees, and form II crystals belong to space group P2(1), with unit-cell parameters a = 69.16, b= 109.78, c = 127.28 Angstrom, beta = 102.29 degrees. The crystals diffracted to 2.0 and 1.7 Angstrom resolutions, respectively, using synchrotron radiation. C1 Osaka Univ, Inst Prot Res, Suita, Osaka 5650871, Japan. Brookhaven Natl Lab, Dept Biol, Upton, NY 11973 USA. Yamanashi Univ, Fac Engn, Dept Appl Chem & Biotechnol, Yamanashi 4008511, Japan. RIKEN, Inst Phys & Chem Res, Wako, Saitama 3510198, Japan. RP Kusunoki, M (reprint author), Osaka Univ, Inst Prot Res, 2-2 Yamadaoka, Suita, Osaka 5650871, Japan. RI Ohkuma, Moriya/A-8100-2011; OI KURISU, GENJI/0000-0002-5354-0807 NR 25 TC 1 Z9 1 U1 0 U2 3 PU MUNKSGAARD INT PUBL LTD PI COPENHAGEN PA 35 NORRE SOGADE, PO BOX 2148, DK-1016 COPENHAGEN, DENMARK SN 0907-4449 J9 ACTA CRYSTALLOGR D JI Acta Crystallogr. Sect. D-Biol. Crystallogr. PD JUN PY 2001 VL 57 BP 857 EP 859 DI 10.1107/S0907444901004012 PN 6 PG 3 WC Biochemical Research Methods; Biochemistry & Molecular Biology; Biophysics; Crystallography SC Biochemistry & Molecular Biology; Biophysics; Crystallography GA 446UV UT WOS:000169533300013 PM 11375507 ER PT J AU Shelkov, V AF Shelkov, V CA BaBar Collaboration TI Results on B decays from BaBar SO ACTA PHYSICA POLONICA B LA English DT Article; Proceedings Paper CT Cracow Epiphany Conference on b-Physics and CP Violation CY JAN 05-07, 2001 CL KRAKOW, POLAND SP Polish State Comm Sci Resx, Polsih Acad Sci, Comm Phys AB We present a summary of 1999-2000 BaBar results from BaBar corresponding to about 8-9 fb(-1) of integrated luminosity. All the numbers given in this writeup are preliminary. We report on measurements of B meson lifetime, B0 (B) over bar (0) mixing, sin2 beta of the CKM triangle, and branching ratios of some charmless B decays. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Shelkov, V (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. NR 21 TC 0 Z9 0 U1 0 U2 0 PU ACTA PHYSICA POLONICA B, JAGELLONIAN UNIV, INST PHYSICS PI KRAKOW PA REYMONTA 4, 30-059 KRAKOW, POLAND SN 0587-4254 J9 ACTA PHYS POL B JI Acta Phys. Pol. B PD JUN PY 2001 VL 32 IS 6 BP 1679 EP 1694 PG 16 WC Physics, Multidisciplinary SC Physics GA 457XC UT WOS:000170161800003 ER PT J AU Tkaczyk, S AF Tkaczyk, S CA CDF Collaboration D0 Collaboration TI CP violation measurements at the Tevatron SO ACTA PHYSICA POLONICA B LA English DT Article; Proceedings Paper CT Cracow Epiphany Conference on b-Physics and CP Violation CY JAN 05-07, 2001 CL KRAKOW, POLAND SP Polish State Comm Sci Resx, Polsih Acad Sci, Comm Phys ID P(P)OVER-BAR COLLISIONS; OSCILLATION FREQUENCY; ROOT-S=1.8 TEV; B-MESON; DECAYS; DETECTOR; CHARGE AB The CDF collaboration has adapted several heavy flavor tagging techniques and employed them in analyses of time-dependent flavor asymmetries using data from the Tevatron Run I. The tagging algorithms were calibrated using low-p(T) inclusive lepton and dilepton trigger data samples. The tagging techniques were applied to a sample of similar to 400 B-d(0)/(B) over bar (0)(d) --> J/psi bK(S)(0) decays and were used to measure the CP violation parameter, sin(2 beta). Prospects for future improved measurements of the CP violation parameters at the Tevatron are briefly discussed. C1 Fermi Natl Accelerator Lab, Batavia, IL 60510 USA. RP Tkaczyk, S (reprint author), Fermi Natl Accelerator Lab, POB 500, Batavia, IL 60510 USA. NR 13 TC 3 Z9 3 U1 0 U2 0 PU ACTA PHYSICA POLONICA B, JAGELLONIAN UNIV, INST PHYSICS PI KRAKOW PA REYMONTA 4, 30-059 KRAKOW, POLAND SN 0587-4254 J9 ACTA PHYS POL B JI Acta Phys. Pol. B PD JUN PY 2001 VL 32 IS 6 BP 1747 EP 1756 PG 10 WC Physics, Multidisciplinary SC Physics GA 457XC UT WOS:000170161800008 ER PT J AU Ward, BFL AF Ward, BFL TI Recoil phase effect in exclusive B decays: Implications for CP violation SO ACTA PHYSICA POLONICA B LA English DT Article; Proceedings Paper CT Cracow Epiphany Conference on B-Physics and CP Violation CY JAN 05-07, 2001 CL KRAKOW, POLAND SP Polish State Comm Sci Res, Polish Acad Sci, Comm Phys ID NONLEPTONIC DECAYS; PENGUIN DIAGRAMS; FACTORIZATION; MESONS; ASYMMETRIES; ELECTROWEAK AB In the perturbative QCD approach to exclusive B decays to two light mesons, the leading twist contribution corresponds to those diagrams in the Lepage-Brodsky expansion in which the would be spectator quark receives its recoil momentum via one gluon exchange. We show that the resulting amplitude, which in the spectator model is real, acquires an imaginary part which may be comparable in size to its real part. Thus, this source of the strong interaction phase in the amplitude must be taken into account in general to discuss, reliably, the expectations for CP violation in B decays at any B-factory type scenario. C1 Univ Tennessee, Dept Phys & Astron, Knoxville, TN 37996 USA. Stanford Univ, Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. CERN, Div Theory, CH-1211 Geneva 23, Switzerland. RP Univ Tennessee, Dept Phys & Astron, Knoxville, TN 37996 USA. NR 28 TC 1 Z9 1 U1 0 U2 0 PU JAGIELLONIAN UNIV PRESS PI KRAKOW PA UL MICHALOWSKIEGO 9-2, KRAKOW, 31126, POLAND SN 0587-4254 EI 1509-5770 J9 ACTA PHYS POL B JI Acta Phys. Pol. B PD JUN PY 2001 VL 32 IS 6 BP 1835 EP 1846 PG 12 WC Physics, Multidisciplinary SC Physics GA 457XC UT WOS:000170161800015 ER PT J AU Laughlin, RB Lonzarich, GG Monthoux, P Pines, D AF Laughlin, RB Lonzarich, GG Monthoux, P Pines, D TI The quantum criticality conundrum SO ADVANCES IN PHYSICS LA English DT Review ID HIGH-TEMPERATURE SUPERCONDUCTORS; CRITICAL-POINT; NORMAL-STATE; SCATTERING; INSULATOR; PSEUDOGAP AB It is well known theoretically that materials possessing distinct adjoining quantum phases at zero temperature can display behaviour that is universal and insensitive to microscopic details. This is the phenomenon of quantum criticality. Universality is, however, a central feature of the phases themselves and one essential to identifying them. Recent developments in the study of correlated-electron materials suggest that quantum criticality is present in these materials and has been masking the true nature of their phases. This raises troubling questions about the relation between theory and experiment in physics, as well as in science generally. C1 Stanford Univ, Dept Phys, Stanford, CA 94305 USA. Univ Cambridge, Cavendish Lab, Cambridge CB3 0HE, England. Univ Calif, Inst Complex Adapt Matter, Los Alamos, NM 87545 USA. Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. RP Laughlin, RB (reprint author), Stanford Univ, Dept Phys, Stanford, CA 94305 USA. NR 23 TC 46 Z9 47 U1 2 U2 24 PU TAYLOR & FRANCIS LTD PI LONDON PA 11 NEW FETTER LANE, LONDON EC4P 4EE, ENGLAND SN 0001-8732 J9 ADV PHYS JI Adv. Phys. PD JUN PY 2001 VL 50 IS 4 BP 361 EP 365 DI 10.1080/00018730110098534 PG 5 WC Physics, Condensed Matter SC Physics GA 499LQ UT WOS:000172573000001 ER PT J AU Marley, NA Gaffney, JS Baird, C Blazer, CA Drayton, PJ Frederick, JE AF Marley, NA Gaffney, JS Baird, C Blazer, CA Drayton, PJ Frederick, JE TI An empirical method for the determination of the complex refractive index of size-fractionated atmospheric aerosols for radiative transfer calculations SO AEROSOL SCIENCE AND TECHNOLOGY LA English DT Article ID OPTICAL-PROPERTIES; ABSORPTION-COEFFICIENT; LIGHT-ABSORPTION; REAL-TIME; INTEGRATING PLATE; ELEMENTAL CARBON; BLACK CARBON; FLAME SOOT; ABSORBING PARTICLES; ACETYLENE SMOKE AB To adequately assess the effects of atmospheric aerosols on climate, their optical constants (scattering and absorption coefficients) must be known. The absorption and scattering coefficients of the aerosols are derived from the real and imaginary parts of the complex refractive index and are dependent on their size and chemical composition. Because aerosol properties vary significantly with location, it is difficult to assign values for the absorption and scattering of solar radiation by aerosols in models of global climate change, This study reports a new method of collecting size-fractionated atmospheric aerosol samples for the purpose of directly measuring their transmission and reflectance spectra followed by the determination of the complex refractive index across the entire atmospherically relevant spectral range. The samples were collected with a modified Sierra high-volume cascade impactor with the usual filter collection surfaces replaced with Teflon sheets machined to hold quartz (ultraviolet [UV]/visible transparent) and/or silver chloride (infrared transparent) sample collection plates. Reflectance and transmission spectra can be obtained on the aerosol samples directly as a function of wavelength, from 280 mn to 2.5 mum, with an integrating sphere coupled to an UV/visible or a Fourier transform infrared (FTIR) spectrophotometer. The effective real and imaginary components of the refractive index of the bulk sample material can then be approximated, as a function of wavelength, from the sample spectra, preliminary results are presented for carbon soot samples generated in the laboratory and for standard diesel soot samples in the UV/visible spectral range. These are compared to results obtained for size-fractionated atmospheric aerosol samples collected near Pasco, WA, West Mesa, AZ, and Argonne, IL. C1 Argonne Natl Lab, Div Environm Res, Argonne, IL 60437 USA. Univ Chicago, Dept Geophys Sci, Chicago, IL 60637 USA. RP Marley, NA (reprint author), Argonne Natl Lab, Div Environm Res, Bldg 203,9700 S Cass Ave, Argonne, IL 60437 USA. NR 92 TC 51 Z9 51 U1 3 U2 12 PU TAYLOR & FRANCIS INC PI PHILADELPHIA PA 325 CHESTNUT ST, SUITE 800, PHILADELPHIA, PA 19106 USA SN 0278-6826 J9 AEROSOL SCI TECH JI Aerosol Sci. Technol. PD JUN PY 2001 VL 34 IS 6 BP 535 EP 549 DI 10.1080/02786820118599 PG 15 WC Engineering, Chemical; Engineering, Mechanical; Environmental Sciences; Meteorology & Atmospheric Sciences SC Engineering; Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences GA 440JB UT WOS:000169171200007 ER PT J AU Tepper, F Lerner, M Ginley, D AF Tepper, F Lerner, M Ginley, D TI Nanosized alumina fibers SO AMERICAN CERAMIC SOCIETY BULLETIN LA English DT Article C1 Argonide Corp, Sanford, FL USA. Russian Acad Sci, Design Technol Ctr, Tomsk, Russia. Natl Renewable Energy Lab, Golden, CO USA. RP Tepper, F (reprint author), Argonide Corp, Sanford, FL USA. NR 0 TC 23 Z9 23 U1 0 U2 6 PU AMER CERAMIC SOC PI WESTERVILLE PA 735 CERAMIC PLACE, PO BOX 6136, WESTERVILLE, OH 43081-6136 USA SN 0002-7812 J9 AM CERAM SOC BULL JI Am. Ceram. Soc. Bull. PD JUN PY 2001 VL 80 IS 6 BP 57 EP 60 PG 4 WC Materials Science, Ceramics SC Materials Science GA 439KE UT WOS:000169115400006 ER PT J AU Malaga-Trillo, E Meyer, A AF Malaga-Trillo, E Meyer, A TI Genome duplications and accelerated evolution of Hox genes and cluster architecture in teleost fishes SO AMERICAN ZOOLOGIST LA English DT Article; Proceedings Paper CT Annual Meeting of the Society-for-Integrative-and-Comparative-Biology CY JAN 04-08, 2000 CL ATLANTA, GEORGIA SP Soc Integrat & Comparat Biol ID HOMEOBOX GENES; MORONE-SAXATILIS; TREE TOPOLOGIES; ZEBRAFISH; ORGANIZATION; VERTEBRATES; CONSEQUENCES; REDUNDANCY; EXPRESSION; DROSOPHILA AB The early origin of four vertebrate Hox gene clusters during the evolution of gnathostomes was likely caused by two consecutive duplications of the entire genome and the subsequent loss of individual genes. The presumed conserved and important roles of these genes in tetrapods during development led to the general assumption that Hox cluster architecture had remained unchanged since the last common ancestor of all jawed vertebrates. But recent data from teleost fishes reveals that this is not the case. Here, we present all analysis of the evolution of vertebrate Hox genes and clusters, with emphasis on the differences between the Hox A clusters of fish (actinopterygian) and tetrapod (sarcopterygian) lineages. In contrast to the general conservation of genomic architecture and gene sequence observed in sarcopterygians, the evolutionary history of actinopterygian Hox clusters likely includes an additional (third) genome duplication that initially increased the number of clusters from four to eight. We document, for the first time, higher rates of gene loss and gene sequence evolution in the Hox genes of fishes compared to those of land vertebrates. These two observations might suggest that two different molecular evolutionary strategies exist in the two major vertebrate lineages. Preliminary data from the African cichlid fish Oreochromis niloticus compared to those of the pufferfish and zebrafish reveal important differences in Hox cluster architecture among fishes and, together with genetic mapping data from Medaka, indicate that the third genome duplication was not zebratish-specific, but probably occurred early in the history of fishes. Each descending fish lineage that has been characterized so far, distinctively modified its Hox cluster architecture through independent secondary losses. This variation is related to the large body plan differences observed among fishes, such as the loss of entire sets of appendages and ribs in some lineages. C1 Univ Konstanz, Dept Biol, D-78457 Constance, Germany. DOE Joint Genome Inst, Walnut Creek, CA 94538 USA. RP Malaga-Trillo, E (reprint author), Univ Konstanz, Dept Biol, D-78457 Constance, Germany. RI Meyer, Axel/C-9826-2009 OI Meyer, Axel/0000-0002-0888-8193 NR 47 TC 54 Z9 58 U1 0 U2 10 PU SOC INTEGRATIVE COMPARATIVE BIOLOGY PI MCLEAN PA 1313 DOLLEY MADISON BLVD, NO 402, MCLEAN, VA 22101 USA SN 0003-1569 J9 AM ZOOL JI Am. Zool. PD JUN PY 2001 VL 41 IS 3 BP 676 EP 686 DI 10.1668/0003-1569(2001)041[0676:GDAAEO]2.0.CO;2 PG 11 WC Zoology SC Zoology GA 510MG UT WOS:000173211400028 ER PT J AU Goshe, MB Conrads, TP Panisko, EA Angell, NH Veenstra, TD Smith, RD AF Goshe, MB Conrads, TP Panisko, EA Angell, NH Veenstra, TD Smith, RD TI Phosphoprotein isotope-coded affinity tag approach for isolating and quantitating phosphopeptides in proteome-wide analyses SO ANALYTICAL CHEMISTRY LA English DT Article ID PHOSPHORYLATION SITES; GENE-EXPRESSION; DNA MICROARRAY; PROTEINS; ELECTROPHORESIS; PEPTIDES; PHOSPHOSERINE; SPECTROMETRY; LEVEL; ACID AB ii method has been developed that utilizes phosphoprotein isotope-coded affinity tags (PhIAT) that combines stable isotope and biotin labeling to enrich and quantitatively measure differences in the O-phosphorylation states of proteins. The PhIAT labeling approach involves hydroxide ion-mediated B-elimination of the O-phosphate moiety and the addition of 1,2-ethanedithiol containing either four alkyl hydrogens (EDT-D-0) or four alkyl deuteriums (EDT-D-4) followed by biotinylation of the EDT-D-0/D-4 moiety using (+)-biotinyl-iodoacetamidyl-3,6-dioxaoctanediamine. The PhIAT reagent, which contains the nucleophilic sulfhydryl and isotopic label covalently linked to a biotin moiety, nas synthesized and has the potential utility to reduce the O-phosphorylation derivatization into a one-step process. The PhIAT labeling approach was initially demonstrated using the model phosphoprotein beta -casein, After proteolytic digestion, the PhIAT-labeled peptides were affinity isolated using immobilized avidin and analyzed using capillary reversed-phase Liquid chromatography-mass spectrometry, phIAT-labeled beta -casein peptides corresponding to peptides containing known sites of O-phosphorylation were isolated and identified. The PhIAT labeling method was also applied to a yeast protein extract. The PhIAT labeling technique provides a reliable method for making quantitative measurements of differences in the O-phosphorylation state of proteins. C1 Pacific NW Natl Lab, Environm & Mol Sci Lab, Richland, WA 99352 USA. RP Smith, RD (reprint author), Pacific NW Natl Lab, Environm & Mol Sci Lab, POB 999,MSIN,K8-98, Richland, WA 99352 USA. RI Smith, Richard/J-3664-2012 OI Smith, Richard/0000-0002-2381-2349 FU NCI NIH HHS [CA 86340] NR 22 TC 284 Z9 299 U1 1 U2 23 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0003-2700 J9 ANAL CHEM JI Anal. Chem. PD JUN 1 PY 2001 VL 73 IS 11 BP 2578 EP 2586 DI 10.1021/ac010081x PG 9 WC Chemistry, Analytical SC Chemistry GA 438PV UT WOS:000169063000041 PM 11403303 ER PT J AU Kim, Y Hurst, GB Doktycz, MJ Buchanan, MV AF Kim, Y Hurst, GB Doktycz, MJ Buchanan, MV TI Improving spot homogeneity by using polymer substrates in matrix-assisted laser desorption/ionization mass spectrometry of oligonucleotides SO ANALYTICAL CHEMISTRY LA English DT Article ID MALDI-TOF ANALYSIS; SINGLE-NUCLEOTIDE POLYMORPHISMS; CHAIN-REACTION PRODUCTS; NUCLEIC-ACID PROBES; DESORPTION-IONIZATION; CAPILLARY-ELECTROPHORESIS; DELAYED EXTRACTION; SAMPLE SUPPORT; FILM SUBSTRATE; DNA ANALYSIS AB We describe a method for improving the homogeneity of MALDI samples prepared for analysis of small, single-stranded oligonucleotides using the widely used DNA matrix system, 3-hydroxypicolinic acid/picolinic acid/ammonium citrate. This matrix system typically produces large crystals around the rim of the dried sample and requires tedious searching of this rim with the laser. However, when a substrate is prepared using both Nafion and a hydrophilic, high-molecular-weight polymer, such as linear polyacrylamide, linear poly(ethylene oxide), or methyl cellulose, oligonucleotide-doped matrix crystals tend to be smaller and more uniformly distributed across the entire spot, thus decreasing the time that is required for locating a usable signal. In addition to MALDI characterization of the spatial distribution of "sweet spots," fluorescence microscopy allows for imaging dye-labeled DNA in dried MALDI spots. The mechanism of enhanced uniformity may involve increased viscosity in the MALDI sample droplet due to partial solubilization of the substrate by the MALDI sample solvent as well as partitioning of the matrix or DNA between the solvent and the undissolved portion of the polymer substrate. 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. RP Hurst, GB (reprint author), Oak Ridge Natl Lab, Div Chem & Analyt Sci, Oak Ridge, TN 37831 USA. RI Doktycz, Mitchel/A-7499-2011; Buchanan, Michelle/J-1562-2016; OI Doktycz, Mitchel/0000-0003-4856-8343; Buchanan, Michelle/0000-0002-8078-4575; Hurst, Gregory/0000-0002-7650-8009 NR 85 TC 43 Z9 43 U1 0 U2 13 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0003-2700 J9 ANAL CHEM JI Anal. Chem. PD JUN 1 PY 2001 VL 73 IS 11 BP 2617 EP 2624 DI 10.1021/ac001392v PG 8 WC Chemistry, Analytical SC Chemistry GA 438PV UT WOS:000169063000046 PM 11403308 ER PT J AU Gottschlich, N Jacobson, SC Culbertson, CT Ramsey, JM AF Gottschlich, N Jacobson, SC Culbertson, CT Ramsey, JM TI Two-dimensional electrochromatography/capillary electrophoresis on a microchip SO ANALYTICAL CHEMISTRY LA English DT Article ID COMPREHENSIVE 2-DIMENSIONAL SEPARATIONS; MICELLAR ELECTROKINETIC CHROMATOGRAPHY; CAPILLARY ZONE ELECTROPHORESIS; FLOW GATING INTERFACE; LIQUID-CHROMATOGRAPHY; MICROCOLUMN-LC; CHIPS; DEVICE; SYSTEM; PERFORMANCE AB A two-dimensional separation system on a microfabricated device was demonstrated using open-channel electrochromatography as the first dimension and capillary electrophoresis as the second dimension. The first dimension was operated under isocratic conditions, and the effluent from the first dimension was repetitively injected into the second dimension every few seconds. A 25-cm separation channel with spiral geometry for open-channel electrochromatography was chemically modified with octadecylsilane and coupled to a 1.2-cm straight separation channel for capillary electrophoresis. Fluorescently labeled products from tryptic digests of beta -casein were analyzed in 13 min with this system. C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Ramsey, JM (reprint author), Oak Ridge Natl Lab, POB 2008, Oak Ridge, TN 37831 USA. OI Culbertson, Christopher/0000-0002-6833-3237 FU NCI NIH HHS [R33CA83238] NR 35 TC 173 Z9 183 U1 0 U2 23 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0003-2700 J9 ANAL CHEM JI Anal. Chem. PD JUN 1 PY 2001 VL 73 IS 11 BP 2669 EP 2674 DI 10.1021/ac001019n PG 6 WC Chemistry, Analytical SC Chemistry GA 438PV UT WOS:000169063000053 PM 11403315 ER PT J AU Zalk, DM AF Zalk, DM TI Grassroots ergonomics: Initiating an ergonomics program utilizing participatory techniques SO ANNALS OF OCCUPATIONAL HYGIENE LA English DT Article; Proceedings Paper CT 4th International Scientific Conference of the International-Occupational-Hygiene-Association CY JUL, 2000 CL CAIRNS, AUSTRALIA DE participatory ergonomics; developing countries; exposure assessment; risk factors; psychological; training; ergonomics; program; musculoskeletal disorders ID DEVELOPING-COUNTRIES; OCCUPATIONAL-HEALTH; EXPOSURE ASSESSMENT; RISK-FACTORS; TEAMS; STRATEGIES; DISORDERS; INDUSTRY; WORKERS; SAFETY AB The introduction of ergonomics programs throughout the world requires an easy to understand and inexpensive process, participatory ergonomic intervention techniques have proven to be beneficial in the prevention of musculoskeletal disorders. The participatory approach to ergonomics has also been found to be a useful application within industrialized (developed) countries and industrially developing countries (IDCs), Grassroots Ergonomics principles utilize expertise within a workforce that focuses on participatory ergonomics interpretations of quantitative and qualitative risk and exposure assessment information that in turn results in a peer-developed ergonomics training, Regardless of the intricacy of the exposure assessment tools, workers should fully assist in gathering and analyzing data, then in identifying and implementing solutions, ii coordinated and multidisciplinary application of this approach within IDCs would succeed in the creation and sharing of job-specific ergonomics training information for high physical exposure professions, such as agriculture, fishing, forestry, mining, and small-scale enterprises, to initiate ergonomics programs regionally, Published by Elsevier Science Ltd on behalf of British Occupational Hygiene Society. C1 Univ Calif Lawrence Livermore Natl Lab, Hazards Control Dept, Livermore, CA 94550 USA. RP Zalk, DM (reprint author), Univ Calif Lawrence Livermore Natl Lab, Hazards Control Dept, Livermore, CA 94550 USA. RI Banks, Tamara/G-3007-2012 NR 43 TC 30 Z9 31 U1 0 U2 3 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0003-4878 J9 ANN OCCUP HYG JI Ann. Occup. Hyg. PD JUN PY 2001 VL 45 IS 4 BP 283 EP 289 DI 10.1016/S0003-4878(01)00005-9 PG 7 WC Public, Environmental & Occupational Health; Toxicology SC Public, Environmental & Occupational Health; Toxicology GA 438TQ UT WOS:000169070700004 PM 11378149 ER PT J AU Johnston, RG Martinez, DD Garcia, ARE AF Johnston, RG Martinez, DD Garcia, ARE TI Were ancient seals secure? SO ANTIQUITY LA English DT Article DE stamp seals; cylinder seals; forgery AB Forgeries of ancient seals have been found in modern times, but there has been little previous analysis of how much security ancient seals might have offered. In his paper, we demonstrate four different vulnerabilities of clay seal impressions using stack methods and materials that were available thousands of years ago. The success of these attacks suggests that ancient stamp and cylinder seal may have been highly vulnerable. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Johnston, RG (reprint author), Los Alamos Natl Lab, Los Alamos, NM 87545 USA. NR 21 TC 1 Z9 1 U1 0 U2 1 PU ANTIQUITY PUBL LTD PI CAMBRIDGE PA NEW HALL, CAMBRIDGE CB3 0DF, ENGLAND SN 0003-598X J9 ANTIQUITY JI Antiquity PD JUN PY 2001 VL 75 IS 288 BP 299 EP 305 PG 7 WC Anthropology; Archaeology SC Anthropology; Archaeology GA 441VW UT WOS:000169251100018 ER PT J AU Milcamps, A Struffi, P de Bruijn, FJ AF Milcamps, A Struffi, P de Bruijn, FJ TI The Sinorhizobium meliloti nutrient-deprivation-induced tyrosine degradation gene hmgA is controlled by a novel member of the arsR family of regulatory genes SO APPLIED AND ENVIRONMENTAL MICROBIOLOGY LA English DT Article ID COMPLETE GENOME SEQUENCE; RHIZOBIUM-MELILOTI; NITROGEN-FIXATION; ESCHERICHIA-COLI; NUCLEOTIDE-SEQUENCE; BACILLUS-SUBTILIS; TETRACYCLINE RESISTANCE; KLEBSIELLA-AEROGENES; IDENTIFICATION; PROTEIN AB The regulation of the nutrient-deprivation-induced Sinorhizobium meliloti homogentisate dioxygenase (hmgA) gene, involved in tyrosine degradation, was examined. hmgA expression was found to be independent of the canonical nitrogen regulation (ntr) system. To identify regulators of hmgA, secondary mutagenesis of an S. meliloti strain harboring a hmgA-luxAB reporter gene fusion (N4) was carried out using transposon Tn1721, Two independent Tn1721 insertions were found to be located in a positive regulatory gene (nitR), encoding a protein sharing amino acid sequence similarity with proteins of the ArsR family of regulators. NitR was found to be a regulator of S. meliloti hmgA expression under nitrogen deprivation conditions, suggesting the presence of a ntr-independent nitrogen deprivation regulatory system. nitR insertion mutations were shown not to affect bacterial growth, nodulation of Medicago sativa (alfalfa) plants, or symbiotic nitrogen fixation under the physiological conditions examined. Further analysis of the nitR locus revealed the presence of open reading frames encoding proteins sharing amino acid sequence similarities with an ATP-binding phosphonate transport protein (PhnN), as well as transmembrane efflux proteins. C1 Michigan State Univ, DOE, Plant Res Lab, E Lansing, MI 48824 USA. Michigan State Univ, NSF, Ctr Microbial Ecol, E Lansing, MI 48824 USA. Michigan State Univ, Genet Program, E Lansing, MI 48824 USA. Michigan State Univ, Dept Microbiol, E Lansing, MI 48824 USA. RP Milcamps, A (reprint author), Michigan State Univ, Dept Bot & Plant Pathol, Plant Biol Bldg,Room 366, E Lansing, MI 48824 USA. NR 50 TC 6 Z9 7 U1 0 U2 1 PU AMER SOC MICROBIOLOGY PI WASHINGTON PA 1752 N ST NW, WASHINGTON, DC 20036-2904 USA SN 0099-2240 J9 APPL ENVIRON MICROB JI Appl. Environ. Microbiol. PD JUN PY 2001 VL 67 IS 6 BP 2641 EP 2648 DI 10.1128/AEM.67.6.2641-2648.2001 PG 8 WC Biotechnology & Applied Microbiology; Microbiology SC Biotechnology & Applied Microbiology; Microbiology GA 437QJ UT WOS:000169004800033 PM 11375175 ER PT J AU Stults, JR Snoeyenbos-West, O Methe, B Lovley, DR Chandler, DP AF Stults, JR Snoeyenbos-West, O Methe, B Lovley, DR Chandler, DP TI Application of the 5 ' fluorogenic exonuclease assay (TaqMan) for quantitative ribosomal DNA and rRNA analysis in sediments SO APPLIED AND ENVIRONMENTAL MICROBIOLOGY LA English DT Article ID POLYMERASE CHAIN-REACTION; REVERSE TRANSCRIPTION-PCR; C VIRUS-RNA; LISTERIA-MONOCYTOGENES; MICROBIAL COMMUNITIES; 5'-NUCLEASE ASSAYS; COMPETITIVE PCR; RT-PCR; SOIL; QUANTIFICATION AB In this study, we report on the development of quantitative PCR and reverse transcriptase PCR assays for the 16S rRNA of Geobacter spp, and identify key issues related to fluorogenic reporter systems for nucleic acid analyses of sediments. The lower detection limit of each assay was 5 to 50 fg of genomic DNA or less than or equal to2 pg of 16S rRNA. TaqMan PCR spectral traces from uncontaminated; amended aquifer sediments were significantly lower (P < 0.0002) than traces for the external standard curve, We also observed a similar, significant decrease in mean quencher emissions for undiluted extracts relative to those for diluted extracts (P < 0.0001), If PCR enumerations were based solely upon the undiluted sample eluant, the TaqMan assay generated an inaccurate result even though the threshold cycle (C-t) measurements were precise and reproducible in the sediment extracts. Assay accuracy was significantly improved by employing a system of replicate dilutions and replicate analyses for both DNA and rRNA quantitation, Our results clearly demonstrate that fluorescence quenching and autofluorescence can significantly affect TaqMan PCR enumeration accuracy, with subsequent implications for the design and implementation of TaqMan PCR to sediments and related environmental samples. C1 Pacific NW Natl Lab, Environm Microbiol Grp, Richland, WA 99352 USA. Univ Massachusetts, Dept Microbiol, Amherst, MA 01003 USA. RP Chandler, DP (reprint author), 900 Battele Blvd,Mail Stop P7-50, Richland, WA 99352 USA. OI Snoeyenbos-West, Oona/0000-0001-9146-7244 NR 49 TC 116 Z9 121 U1 0 U2 13 PU AMER SOC MICROBIOLOGY PI WASHINGTON PA 1752 N ST NW, WASHINGTON, DC 20036-2904 USA SN 0099-2240 J9 APPL ENVIRON MICROB JI Appl. Environ. Microbiol. PD JUN PY 2001 VL 67 IS 6 BP 2781 EP 2789 DI 10.1128/AEM.67.6.2781-2789.2001 PG 9 WC Biotechnology & Applied Microbiology; Microbiology SC Biotechnology & Applied Microbiology; Microbiology GA 437QJ UT WOS:000169004800053 PM 11375195 ER PT J AU Lehman, RM Colwell, FS Bala, GA AF Lehman, RM Colwell, FS Bala, GA TI Attached and unattached microbial communities in a simulated basalt aquifer under fracture- and porous-flow conditions SO APPLIED AND ENVIRONMENTAL MICROBIOLOGY LA English DT Article ID SUBSTRATE UTILIZATION PATTERNS; CARBON-SOURCE UTILIZATION; DEEP CRYSTALLINE BEDROCK; FREE-LIVING BACTERIA; SOUTHEASTERN SWEDEN; SUBSURFACE; GROUNDWATER; DIVERSITY; BIODEGRADATION; DEGRADATION AB Bench scale column studies were used to examine the partitioning of microorganisms between groundwater and a geologic medium and to examine the effect of hydrogeology (i.e., porous- versus fracture-how) on organism partitioning. Replicated columns were constructed with intact basalt core segments that contained natural fractures and with the same basalt crushed into particles. The columns were perfused with groundwater, and upon reaching a steady state, the columns were sacrificed and the attached and unattached communities were analyzed by multiple approaches. The analyses included the total number of cells, the phylogenetic affiliation of the cells (i.e., the alpha, beta, and gamma subclasses of the class Proteobacteria and gram positives with high G+C DNA content) by fluorescent in situ hybridization (FISH), number and taxonomic affiliation by fatty acid methyl ester profiles of culturable heterotrophs, most-probable-number estimates of methanotrophs and phenol oxidizers, and whole-community sole carbon source utilization patterns from Biolog GN microplates, In the packed columns, about 99% of the total biomass (per cubic centimeter of porous medium) was attached to the geologic medium. Lack of equitable units precluded a comparison of attached and unattached biomasses in the fractured columns where the attached biomass was expressed per unit of surface area. Compositional differences in the attached and unattached communities were evidenced by (i) the recovery of Pseudomonas stutzeri, an Enterococcus sp., and Bacillus psychrophilus from the groundwater and not from the basalt, (ii) differences between community carbon source utilization patterns, and (iii) the relative abundances of different phylogenetic groups estimated by FISH in both column types. In the packed columns, attached communities were depleted of members of the (alpha- and beta -Proteobacteria subclasses in comparison to those in the corresponding groundwater, In the fractured columns, attached communities were enriched in gram-positive Bacteria and gamma -Proteobacteria and depleted of beta -Proteobacteria, in comparison to those in the corresponding groundwater, Segregation of populations and their activities, possibly modified by attachment to geologic media, may influence contaminant fate and transport in the subsurface and impact other in situ applications. C1 Idaho Natl Engn & Environm Lab, Dept Biotechnol, Idaho Falls, ID 83415 USA. RP Lehman, RM (reprint author), Idaho Natl Engn & Environm Lab, Dept Biotechnol, POB 1625, Idaho Falls, ID 83415 USA. NR 62 TC 79 Z9 81 U1 1 U2 12 PU AMER SOC MICROBIOLOGY PI WASHINGTON PA 1752 N ST NW, WASHINGTON, DC 20036-2904 USA SN 0099-2240 J9 APPL ENVIRON MICROB JI Appl. Environ. Microbiol. PD JUN PY 2001 VL 67 IS 6 BP 2799 EP 2809 DI 10.1128/AEM.67.6.2799-2809.2001 PG 11 WC Biotechnology & Applied Microbiology; Microbiology SC Biotechnology & Applied Microbiology; Microbiology GA 437QJ UT WOS:000169004800055 PM 11375197 ER PT J AU Lee, SH Naulleau, P Goldberg, KA Cho, CH Jeong, S Bokor, J AF Lee, SH Naulleau, P Goldberg, KA Cho, CH Jeong, S Bokor, J TI Extreme-ultraviolet lensless Fourier-transform holography SO APPLIED OPTICS LA English DT Article ID FLARE AB We demonstrate 100-nm-resolution holographic aerial image monitoring based on lensless Fourier-transform holography at extreme-UV (EUV) wavelengths, using synchrotron-based illumination. This method can be used to monitor the coherent imaging performance of EW lithographic optical systems. The system has been implemented in the EUV phase-shifting point-diffraction interferometer recently developed at Lawrence Berkeley National Laboratory. Here we introduce the idea of the holographic aerial image-recording technique and present imaging performance characterization results for a 10 x Schwarzschild objective, a prototype EW lithographic optic. The results are compared with simulations, and good agreement is obtained. Various object patterns, including phase-shift-enhanced patterns, have been studied. Finally, the application of the holographic aerial image-recording technique to EUV multilayer mask-blank defect characterization is discussed. (C) 2001 Optical Society of America. C1 Univ Calif Berkeley, Dept Elect Engn & Comp Sci, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Ctr Xray Opt, Berkeley, CA 94720 USA. RP Lee, SH (reprint author), Univ Calif Berkeley, Dept Elect Engn & Comp Sci, Berkeley, CA 94720 USA. EM shlee@lbl.gov RI Bokor, Jeffrey/A-2683-2011 NR 11 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 JUN 1 PY 2001 VL 40 IS 16 BP 2655 EP 2661 DI 10.1364/AO.40.002655 PG 7 WC Optics SC Optics GA 436AR UT WOS:000168914800008 PM 18357280 ER PT J AU Fassbender, M de Villiers, D Nortier, M van der Walt, N AF Fassbender, M de Villiers, D Nortier, M van der Walt, N TI The Br-nat(p,x)Se-73,Se-75 nuclear processes: a convenient route for the production of radioselenium tracers relevant to amino acid labelling SO APPLIED RADIATION AND ISOTOPES LA English DT Article DE Se-73; Se-75; excitation functions; thin and thick yield; selenomethionine; triphenylphosphine; polymer-supported synthesis; radio-HPLC ID EXCITATION-FUNCTIONS; THERMOCHROMATOGRAPHIC SEPARATION; NO-CARRIER; SE-73; GERMANIUM; COPPER AB A possible route for the production of no-carrier-added (n.c.a.) Se-73 (T-1/2 = 7.1 h) and Se-75 (120 d) is introduced.D,L-2-Amino-4-([Se-73]methyl-seleno) butanoic acid (D,L-[Se-73]selenomethionine) with an overall radiochemical yield of > 40% could be prepared via a 3-step polymer-supported synthesis after successful separation of Se-73 from KBr targets. Excitation functions for the Br-nat(p,x) Se-72,Se-73,Se-75 processes were measured from threshold up to 100 MeV utilizing pellets of pressed KBr. Targets were irradiated at the NAC cyclotron with proton beams having primary energies of 40.4, 66.8 and 100.9 MeV. The calculated 73Se yield (EOB) for 1 h irradiation in 1 muA of beam at the optimum proton energy range of 62 --> 42 MeV is 81.4 MBq (2.2 mCi), and the calculated Se-75 yield (EOB) for the overall range 62 MeV --> threshold for the same irradiation conditions is 0.97 MBq (0.026mCi). (C) 2001 Elsevier Science Ltd. All rights reserved. C1 Natl Accelerator Ctr, ZA-7131 Faure, South Africa. RP Fassbender, M (reprint author), Univ Calif Los Alamos Natl Lab, MS J514, Los Alamos, NM 87545 USA. NR 22 TC 7 Z9 8 U1 0 U2 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0969-8043 J9 APPL RADIAT ISOTOPES JI Appl. Radiat. Isot. PD JUN PY 2001 VL 54 IS 6 BP 905 EP 913 DI 10.1016/S0969-8043(00)00359-6 PG 9 WC Chemistry, Inorganic & Nuclear; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Chemistry; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA 415XL UT WOS:000167748800005 PM 11300403 ER PT J AU McCall, MR Carr, AC Forte, TM Frei, B AF McCall, MR Carr, AC Forte, TM Frei, B TI LDL modified by hypochlorous acid is a potent inhibitor of lecithin-cholesterol acyltransferase activity SO ARTERIOSCLEROSIS THROMBOSIS AND VASCULAR BIOLOGY LA English DT Article DE chloramines; HDL; LDL; lecithin-cholesterol acyltransferase; hypochlorous acid ID LOW-DENSITY-LIPOPROTEIN; HUMAN ATHEROSCLEROTIC LESIONS; ALPHA-1-PROTEINASE INHIBITOR; LIPID HYDROPEROXIDES; METHIONINE RESIDUES; HUMAN-NEUTROPHILS; MODIFIED PROTEINS; OXIDIZED LDL; OXIDATION; MYELOPEROXIDASE AB Modification of low density lipoprotein (LDL) by myeloperoxidase-generated HOCl has been implicated in human atherosclerosis, Incubation of LDL with HOCl generates several reactive intermediates, primarily N-chloramines, which may react with other biomolecules. In this study, we investigated the effects of HOCl-modified LDL on the activity of lecithin-cholesterol acyltransferase (LCAT), an enzyme essential for high density lipoprotein maturation and the antiatherogenic reverse cholesterol transport pathway. We exposed human LDL (0.5 mg protein/mL) to physiological concentrations of HOCl (25 to 200 mu mol/L) and characterized the resulting LDL modifications to apolipoprotein B and lipids; the modified LDL was subsequently incubated with apolipoprotein B-depleted plasma (density >1.063 g/mL fraction), which contains functional LCAT. Increasing concentrations of HOCl caused various modifications to LDL, primarily, loss of lysine residues and increases in N-chloramines and electrophoretic mobility, whereas lipid hydroperoxides were only minor products. LCAT activity was extremely sensitive to HOCl-modified LDL and was reduced by 23% and 93% by LDL preincubated with 25 and 100 mu mol/L HOCl, respectively. Addition of 200 rho mol/L ascorbate or N-acetyl derivatives of cysteine or methionine completely prevented LCAT inactivation by LDL preincubated with less than or equal to 200 mu mol/L HOCl. Protecting the free thiol groups of LCAT with 5,5 ' -dithio-bis-(2-nitrobenzoic acid) before exposure to HOCl-modified LDL, which inhibits lipid hydroperoxide-mediated inactivation of LCAT, failed to prevent the loss of enzyme activity. Our data indicate that N-chloramines from HOCl-modified LDL mediate the loss of plasma LCAT activity and provide a novel mechanism by which myeloperoxidase-generated HOCl may promote atherogenesis. C1 Oregon State Univ, Linus Pauling Inst Sci & Med, Corvallis, OR 97331 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Life Sci, Berkeley, CA 94720 USA. RP Frei, B (reprint author), Oregon State Univ, Linus Pauling Inst Sci & Med, 571 Weniger Hall, Corvallis, OR 97331 USA. FU NHLBI NIH HHS [HL-18574, HL-49954, HL-56170, HL-60886] NR 46 TC 22 Z9 23 U1 1 U2 3 PU LIPPINCOTT WILLIAMS & WILKINS PI PHILADELPHIA PA 530 WALNUT ST, PHILADELPHIA, PA 19106-3621 USA SN 1079-5642 J9 ARTERIOSCL THROM VAS JI Arterioscler. Thromb. Vasc. Biol. PD JUN PY 2001 VL 21 IS 6 BP 1040 EP 1045 PG 6 WC Hematology; Peripheral Vascular Disease SC Hematology; Cardiovascular System & Cardiology GA 443ZK UT WOS:000169373300027 PM 11397717 ER PT J AU Leighly, KM Halpern, JP Helfand, DJ Becker, RH Impey, CD AF Leighly, KM Halpern, JP Helfand, DJ Becker, RH Impey, CD TI First observations of the second-brightest quasar SO ASTRONOMICAL JOURNAL LA English DT Article DE galaxies : active; quasars : individual (PHL 1811); X-rays ID LINE SEYFERT-1 GALAXIES; AGN; ABSORPTION AB We report the discovery of a new bright quasar, PHL 1811, as part of a follow-up program to identify bright quasars in the FIRST radio survey. With B = 13.9, R = 13.9, and z = 0.192, this quasar is now the second-brightest quasar (in apparent magnitude) known beyond z = 0.1. Optically classified as a narrow-line Seyfert 1 galaxy (NLS1), PHL 1811 is unusual for an object in this class in that it was not detected in X-rays in the ROSAT All-Sky Survey or in any previous X-ray survey. A follow-up BeppoSAX observation confirms that it is deficient in X-rays compared with other quasars, but poor signal-to-noise ratio prevents a definitive characterization of the X-ray spectrum. We consider three alternative hypotheses to explain why PHL 1811 is a weak X-ray source: (1) it is a broad absorption line quasi-stellar object and suffers X-ray absorption; (2) like several other luminous NLS1s, it exhibits high-amplitude X-ray variability and has been observed only when it is in an X-ray-quiescent state; and (3) it is intrinsically weak because it simply lacks an X-ray-emitting region. C1 Univ Oklahoma, Dept Phys & Astron, Norman, OK 73019 USA. Columbia Univ, Dept Astron, New York, NY 10027 USA. Univ Calif Davis, Dept Phys, Davis, CA 95616 USA. Univ Calif Lawrence Livermore Natl Lab, Inst Geophys & Planetary Phys, Livermore, CA 94551 USA. Univ Arizona, Steward Observ, Tucson, AZ 85721 USA. RP Leighly, KM (reprint author), Univ Oklahoma, Dept Phys & Astron, 440 W Brooks St, Norman, OK 73019 USA. NR 29 TC 25 Z9 25 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-6256 J9 ASTRON J JI Astron. J. PD JUN PY 2001 VL 121 IS 6 BP 2889 EP 2894 DI 10.1086/321094 PG 6 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 444FC UT WOS:000169387500002 ER PT J AU Blanton, EL Gregg, MD Helfand, DJ Becker, RH Leighly, KM AF Blanton, EL Gregg, MD Helfand, DJ Becker, RH Leighly, KM TI The environments of a complete moderate-redshift sample of first bent-double radio sources SO ASTRONOMICAL JOURNAL LA English DT Article DE galaxies : clusters : general; galaxies : elliptical and lenticular, cD; intergalactic medium; radio continuum; X-rays ID 20-CM VLA SURVEY; ABELL CLUSTERS; OPTICAL OBSERVATIONS; SURFACE PHOTOMETRY; NUMBER COUNTS; GALAXIES; EMISSION; CATALOG; EVOLUTION; MERGERS AB We present an optical spectroscopic and imaging study of the environments of a complete sample of moderate-redshift bent-double radio sources. More than half of the 40 radio galaxies in the sample are associated with clusters of Abell richness class 0 or greater at z < 0.4. Most of the remaining objects are associated with groups, although a few appear to be hosted by nearly isolated elliptical galaxies. For the bent doubles appearing in poor environments, either dense gas must be associated with the systems to provide the ram pressure to bend the lobes or alternative bending mechanisms must be invoked to explain the radio morphologies. Correlation with the ROSAT All-Sky Survey bright and faint source catalogs reveals that the majority of the z < 0.2 objects in our sample that we classify optically as clusters are also X-ray sources. C1 Univ Virginia, Dept Astron, Charlottesville, VA 22903 USA. Columbia Astrophys Lab, New York, NY 10027 USA. Univ Calif Davis, Dept Phys, Davis, CA 95616 USA. Lawrence Livermore Natl Lab, Inst Geophys & Planetary Phys, Livermore, CA 94550 USA. RP Blanton, EL (reprint author), Univ Virginia, Dept Astron, POB 3818, Charlottesville, VA 22903 USA. EM eblanton@virginia.edu; gregg@igpp.ucllnl.org; djh@astro.columbia.edu; bob@igpp.ucllnl.org; leighly@mail.nhn.ou.edu RI Blanton, Elizabeth/H-4501-2014 NR 43 TC 26 Z9 26 U1 0 U2 1 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0004-6256 J9 ASTRON J JI Astron. J. PD JUN PY 2001 VL 121 IS 6 BP 2915 EP 2927 DI 10.1086/321074 PG 13 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 444FC UT WOS:000169387500004 ER PT J AU Blanton, M Blasi, P Olinto, AV AF Blanton, M Blasi, P Olinto, AV TI The Greisen-Zatzepin-Kuzmin feature in our neighborhood of the universe SO ASTROPARTICLE PHYSICS LA English DT Article DE cosmic rays; ultra-high energy; propagation; acceleration ID ENERGY COSMIC-RAYS; MAGNETIC-FIELDS; LOCAL SUPERCLUSTER; NEARBY GALAXIES; SPECTRUM; PROPAGATION; CUTOFF; REDSHIFT; DENSITY; ORIGIN AB We calculate numerically the spectrum of ultra-high energy cosmic rays on Earth assuming that their sources are distributed in space like the observed galaxies. We use the CfA2 and the PSCz galaxy redshift surveys to model the local galaxy distribution, properly taking into account the galaxy selection functions for each survey. When the survey selection effects are included, we find that the local overdensity is only a factor of 2, an order of magnitude less than used in some earlier studies. An overdensity of 2 is not enough to bridge the gap between the predicted number of events above 10(20) eV and the measured flux at these highest energies. This conclusion is particularly strong for soft injection spectra (proportional to E-3) where the observed number of events is 6 sigma higher than the expected one. However, if the injection spectrum is hard (proportional to E-2), the small local overdensity helps bring the present data within 2 sigma of the low number of events predicted above 1020 eV. In this case, the Greisen-Zatzepin-Kurmin cutoff is not a cutoff but rather a feature in the cosmic ray spectrum. (C) 2001 Elsevier Science B.V. All rights reserved. C1 Univ Chicago, Enrico Fermi Inst, Dept Astron & Astrophys, Chicago, IL 60637 USA. Fermilab Natl Accelerator Lab, Batavia, IL 60510 USA. RP Univ Chicago, Enrico Fermi Inst, Dept Astron & Astrophys, Chicago, IL 60637 USA. EM olinto@oddjob.uchicago.edu OI Blasi, Pasquale/0000-0003-2480-599X NR 49 TC 50 Z9 50 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0927-6505 EI 1873-2852 J9 ASTROPART PHYS JI Astropart Phys. PD JUN PY 2001 VL 15 IS 3 BP 275 EP 286 DI 10.1016/S0927-6505(00)00157-2 PG 12 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 438CP UT WOS:000169036400003 ER PT J AU Price, PN Fischer, ML Gadgil, AJ Sextro, RG AF Price, PN Fischer, ML Gadgil, AJ Sextro, RG TI An algorithm for real-time tomography of gas concentrations, using prior information about spatial derivatives SO ATMOSPHERIC ENVIRONMENT LA English DT Article DE computed tomography; concentration mapping; air flow; pollutant dispersion; optical remote sensing ID COMPUTED-TOMOGRAPHY; CONCENTRATION PROFILES; OP-FTIR; RECONSTRUCTION; AIR; ART AB We present a new computed tomography method, the low third derivative (LTD) method, that is particularly suited for reconstructing the spatial distribution of gas concentrations from path-integral data for a small number of optical paths. The method finds a spatial distribution of gas concentrations that (1) has path integrals that agree with measured path integrals, and (2) has a low third spatial derivative in each direction, at every point. The trade-off between (1) and (2) is controlled by an adjustable parameter, which can be set based on analysis of the path-integral data. The method produces a set of linear equations, which can be solved with a single matrix multiplication if the constraint that all concentrations must be positive is ignored; the method is therefore extremely rapid. Analysis of experimental data from thousands of concentration distributions shows that the method works nearly as well as smooth basis function minimization (the best method previously available), yet is about 100 times faster. (C) 2001 Published by Elsevier Science Ltd. C1 Lawrence Berkeley Natl Lab, Indoor Environm Dept, Berkeley, CA 94720 USA. RP Price, PN (reprint author), Lawrence Berkeley Natl Lab, Indoor Environm Dept, Berkeley, CA 94720 USA. OI Gadgil, Ashok/0000-0002-0357-9455 NR 16 TC 19 Z9 20 U1 1 U2 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 1352-2310 J9 ATMOS ENVIRON JI Atmos. Environ. PD JUN PY 2001 VL 35 IS 16 BP 2827 EP 2835 DI 10.1016/S1352-2310(01)00082-6 PG 9 WC Environmental Sciences; Meteorology & Atmospheric Sciences SC Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences GA 440HH UT WOS:000169169500004 ER PT J AU Fischer, ML Price, PN Thatcher, TL Schwalbe, CA Craig, MJ Wood, EE Sextro, RG Gadgil, AJ AF Fischer, ML Price, PN Thatcher, TL Schwalbe, CA Craig, MJ Wood, EE Sextro, RG Gadgil, AJ TI Rapid measurements and mapping of tracer gas concentrations in a large indoor space SO ATMOSPHERIC ENVIRONMENT LA English DT Article DE tracer gas measurement; optical remote sensing; computed tomography; air flow ID COMPUTED-TOMOGRAPHY; RECONSTRUCTION; CONVECTION; POLLUTANT; SYSTEM; LIDAR AB Rapid mapping of gas concentrations in air benefits studies of atmospheric phenomena ranging from pollutant dispersion to surface layer meteorology. Here we demonstrate a technique that combines multiple-open-path tunable-diode-laser spectroscopy and computed tomography to map tracer gas concentrations with approximately 0.5 m spatial and 7 s temporal resolution. Releasing CH4 as a tracer gas in a large (7 m x 9 m x 11 m high) ventilated chamber, we measured path-integrated CH4 concentrations over a planar array of 28 "long" (2-10m) optical paths, recording a complete sequence of measurements every 7 a during the course of hour-long experiments. Maps of CH, concentration were reconstructed from the long path data using a computed tomography algorithm that employed simulated annealing to search for a best fit solution. The reconstructed maps were compared with simultaneous measurements from 25 "short" (0.5m) optical paths located in the same measurement plane. On average, the reconstructed maps capture similar to 74% of the variance in the short path measurements. The accuracy of the reconstructed maps is limited, in large part, by the number of optical paths and the time required for the measurement. Straightforward enhancements to the instrumentation will allow rapid mapping of three-dimensional gas concentrations in indoor and outdoor air, with sub-second temporal resolution. (C) 2001 Elsevier Science Ltd. All rights reserved. C1 Ernest Orlando Lawrence Berkeley Natl Lab, Environm Energy Technol Div, Indoor Environm Dept, Berkeley, CA 94720 USA. RP Fischer, ML (reprint author), Ernest Orlando Lawrence Berkeley Natl Lab, Environm Energy Technol Div, Indoor Environm Dept, Bldg 90-3058,1 Cyclotron Rd, Berkeley, CA 94720 USA. OI Gadgil, Ashok/0000-0002-0357-9455 NR 13 TC 17 Z9 18 U1 1 U2 6 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 1352-2310 J9 ATMOS ENVIRON JI Atmos. Environ. PD JUN PY 2001 VL 35 IS 16 BP 2837 EP 2844 DI 10.1016/S1352-2310(01)00081-4 PG 8 WC Environmental Sciences; Meteorology & Atmospheric Sciences SC Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences GA 440HH UT WOS:000169169500005 ER PT J AU Munthe, J Wangberg, I Pirrone, N Iverfeldt, A Ferrara, R Ebinghaus, R Feng, X Gardfeldt, K Keeler, G Lanzillotta, E Lindberg, SE Lu, J Mamane, Y Prestbo, E Schmolke, S Schroeder, WH Sommar, J Sprovieri, F Stevens, RK Stratton, W Tuncel, G Urba, A AF Munthe, J Wangberg, I Pirrone, N Iverfeldt, A Ferrara, R Ebinghaus, R Feng, X Gardfeldt, K Keeler, G Lanzillotta, E Lindberg, SE Lu, J Mamane, Y Prestbo, E Schmolke, S Schroeder, WH Sommar, J Sprovieri, F Stevens, RK Stratton, W Tuncel, G Urba, A TI Intercomparison of methods for sampling and analysis of atmospheric mercury species SO ATMOSPHERIC ENVIRONMENT LA English DT Article; Proceedings Paper CT 3rd European Land-Ocean Interaction Studies (ELOISE) Conference CY DEC 01-04, 1999 CL NORTHWIJKERHOUT, NETHERLANDS DE mercury; measurement; atmosphere; speciation ID AMBIENT AIR; PARTICULATE MERCURY; DIVALENT MERCURY; GASEOUS MERCURY; CENTRAL-EUROPE; DENUDER; METHYLMERCURY; PRECIPITATION AB An intercomparison for sampling and analysis of atmospheric mercury species was held in Tuscany, June 1998. Methods for sampling and analysis of total gaseous mercury (TGM), reactive gaseous mercury (RGM) and total particulate mercury (TPM) were used in parallel sampling over a period of 4 days. The results show that the different methods employed for TGM compared well whereas RGM and TPM showed a somewhat higher variability. Measurement results of RGM and TPM improved over the time period indicating that activities at the sampling site during set-up and initial sampling affected the results. Especially the TPM measurement results were affected. Additional parallel sampling was performed for two of the TPM methods under more controlled conditions which yielded more comparable results. (C) 2001 Elsevier Science Ltd. All rights reserved. C1 Swedish Environm Res Inst, IVL, S-40258 Gothenburg, Sweden. Univ Calabria, CNR, Inst Atmospher Pollut, IIA, I-87036 Rende, Italy. CNR, Inst Biophys, I-57127 Pisa, Italy. GKSS Forschungszentrum Geesthacht GmbH, Inst Phys & Chem Anal, D-21502 Geesthacht, Germany. Gothenburg Univ, Dept Chem, S-41296 Gothenburg, Sweden. Univ Michigan, Air Qual Lab, Ann Arbor, MI 48109 USA. Oak Ridge Natl Lab, Div Environm Sci, Oak Ridge, TN 37831 USA. Environm Canada, Atmospher Environm Serv, Downsview, ON M3H 5T4, Canada. Technion Israel Inst Technol, IL-32000 Haifa, Israel. Frontier Geosci Ltd, Seattle, WA 98109 USA. US EPA, FL Dept Environm Protect, Res Triangle Pk, NC 27711 USA. Earlham Coll, Dept Chem, Richmond, IN 47374 USA. Middle E Tech Univ, Dept Environm Engn, TR-06531 Ankara, Turkey. Inst Phys, Environm Res Dept, LT-2600 Vilnius, Lithuania. RP Munthe, J (reprint author), Swedish Environm Res Inst, IVL, POB 47086, S-40258 Gothenburg, Sweden. RI Feng, Xinbin/F-4512-2011; Mason, Robert/A-6829-2011; OI Feng, Xinbin/0000-0002-7462-8998; /0000-0002-5161-9597 NR 39 TC 115 Z9 127 U1 3 U2 30 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 1352-2310 J9 ATMOS ENVIRON JI Atmos. Environ. PD JUN PY 2001 VL 35 IS 17 BP 3007 EP 3017 DI 10.1016/S1352-2310(01)00104-2 PG 11 WC Environmental Sciences; Meteorology & Atmospheric Sciences SC Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences GA 443VR UT WOS:000169363100005 ER PT J AU Wall, ME Dyck, PA Brettin, TS AF Wall, ME Dyck, PA Brettin, TS TI SVDMAN - singular value decomposition analysis of microarray data SO BIOINFORMATICS LA English DT Article ID TRANSCRIPTIONAL PROGRAM; IDENTIFICATION; PATTERNS; PROTEINS; YEAST AB We have developed two novel methods for Singular Value Decomposition analysis (SVD) of microarray data. The first is a threshold-based method for obtaining gene groups, and the second is a method for obtaining a measure of confidence in SVD analysis. Gene groups are obtained by identifying elements of the left singular vectors, or gene coefficient vectors, that are greater in magnitude than the threshold WN-1/2, where N is the number of genes, and W is a weight factor whose default value is 3. The groups are non-exclusive and may contain genes of opposite (i.e. inversely correlated) regulatory response. The confidence measure is obtained by systematically deleting assays from the data set, interpolating the SVD of the reduced data set to reconstruct the missing assay, and calculating the Pearson correlation between the reconstructed assay and the original data. This confidence measure is applicable when each experimental assay corresponds to a value of parameter that can be interpolated, such as time, dose or concentration. Algorithms for the grouping method and the confidence measure are available in a software application called SVD Microarray ANalysis (SVDMAN). In addition to calculating the SVD for generic analysis, SVDMAN provides a new means for using microarray data to develop hypotheses for gene associations and provides a measure of confidence in the hypotheses, thus extending current SVD research in the area of global gene expression analysis. C1 Univ Calif Los Alamos Natl Lab, Biosci Div, Los Alamos, NM 87545 USA. RP Brettin, TS (reprint author), Univ Calif Los Alamos Natl Lab, Biosci Div, POB 1663, Los Alamos, NM 87545 USA. NR 14 TC 58 Z9 61 U1 0 U2 1 PU OXFORD UNIV PRESS PI OXFORD PA GREAT CLARENDON ST, OXFORD OX2 6DP, ENGLAND SN 1367-4803 J9 BIOINFORMATICS JI Bioinformatics PD JUN PY 2001 VL 17 IS 6 BP 566 EP 568 DI 10.1093/bioinformatics/17.6.566 PG 3 WC Biochemical Research Methods; Biotechnology & Applied Microbiology; Computer Science, Interdisciplinary Applications; Mathematical & Computational Biology; Statistics & Probability SC Biochemistry & Molecular Biology; Biotechnology & Applied Microbiology; Computer Science; Mathematical & Computational Biology; Mathematics GA 444NC UT WOS:000169404700014 PM 11395437 ER PT J AU Langan, P Nishiyama, Y Chanzy, H AF Langan, P Nishiyama, Y Chanzy, H TI X-ray structure of mercerized cellulose II at 1 angstrom resolution SO BIOMACROMOLECULES LA English DT Article ID D-CELLOTETRAOSE HEMIHYDRATE; STATE C-13 NMR; CRYSTAL-STRUCTURE; NATIVE CELLULOSE; DIFFRACTION; BETA; PARALLEL; COTTON; MODEL AB A revised crystal structure for mercerized cellulose based on high-resolution synchrotron X-ray data collected from ramie fibers is reported (space group P2(1), a = 8.10(3) Angstrom, b = 9.03(3) Angstrom, c = 10.31(5) Angstrom, gamma = 117.10(5)degrees; 751 reflections in 304 composite spots; theta < 2 1.1&DEG;; λ = 0.7208 &ANGS;; LALS refinement with d > 1.5 Angstrom, R" = 0.16, SHELX97 refinement with d > 1 Angstrom, R = 0.21). As with regenerated cellulose the crystal structure consists of antiparallel chains with different conformations but with the hydroxymethyl groups of both chains near the gt position. However, the conformation of the hydroxymethyl group of the center chain in the structure reported here differs significantly from the conformation in regenerated cellulose. This may be related to a large observed difference in the amount of hydroxymethyl group disorder: similar to30% for regenerated cellulose and similar to10% for mercerized cellulose. C1 Los Alamos Natl Lab, Biosci Div, Los Alamos, NM 87545 USA. Univ Tokyo, Grad Sch Agr & Life Sci, Dept Biomat Sci, Tokyo 1138657, Japan. CNRS, Ctr Rech Macromol Vegetales, F-38041 Grenoble, France. RP Langan, P (reprint author), Los Alamos Natl Lab, Biosci Div, M888, Los Alamos, NM 87545 USA. RI Nishiyama, Yoshiharu/A-3492-2012; Chanzy, Henri/A-3526-2012; Langan, Paul/N-5237-2015 OI Nishiyama, Yoshiharu/0000-0003-4069-2307; Langan, Paul/0000-0002-0247-3122 NR 29 TC 219 Z9 222 U1 9 U2 85 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 1525-7797 J9 BIOMACROMOLECULES JI Biomacromolecules PD SUM PY 2001 VL 2 IS 2 BP 410 EP 416 DI 10.1021/mb005612q PG 7 WC Biochemistry & Molecular Biology; Chemistry, Organic; Polymer Science SC Biochemistry & Molecular Biology; Chemistry; Polymer Science GA 528RF UT WOS:000174256200012 PM 11749200 ER PT J AU Ahn, JH Sposato, P Kim, SI Walton, JD AF Ahn, JH Sposato, P Kim, SI Walton, JD TI Molecular cloning and characterization of cel2 from the fungus Cochlibolus carbonum SO BIOSCIENCE BIOTECHNOLOGY AND BIOCHEMISTRY LA English DT Article DE cellulase; Cochliobolus carbonum; pathogenicity ID PATHOGEN COCHLIOBOLUS-CARBONUM; TARGETED GENE DISRUPTION; TRICHODERMA-REESEI; ENDOGLUCANASE-I; MAIZE; WALL; EXPRESSION; SEQUENCE; ENZYMES; LACKING AB ri new cellulase gene, cel2, from the filamentous fungus Cochliobolus carbonum was cloned by using egl-1 of Trichoderma reesei as a heterologous probe. DNA blot analysis of cel2 showed that this gene is present as a single copy. The gene contains one 49-bp- intron. cel2 encodes a predicted protein (cel2p) of 423 amino acids with a molecular mass of 45.8 kDa. The predicted pi is 4.96. It shows similarity to other endoglucanases from various fungi. From the comparison with other cellulase genes, cel2 belongs to family 7 of glucohydrolases, cel2 is located on a 2.5-Mb chromosome in C. carbonum and its expression is repressed by sucrose. A cel2 mutant of C. carbonum was created by transformation-mediated gene disruption. The pathogenicity of the mutant was indistinguishable from the wild type, indicating that cel2 by itself is not important for pathogenicity. C1 Konkuk Univ, Dept Forest Resource, Kwangjin Gu, Seoul 143701, South Korea. Michigan State Univ, DOE, Plant Res Lab, E Lansing, MI 48824 USA. Seoul Natl Univ, Sch Agr Biotechnol, Suwon, South Korea. RP Ahn, JH (reprint author), Konkuk Univ, Dept Forest Resource, Kwangjin Gu, 1 Hwayang Dong, Seoul 143701, South Korea. EM jhahn@konkuk.ac.kr NR 27 TC 6 Z9 7 U1 0 U2 3 PU TAYLOR & FRANCIS LTD PI ABINGDON PA 4 PARK SQUARE, MILTON PARK, ABINGDON OX14 4RN, OXON, ENGLAND SN 0916-8451 EI 1347-6947 J9 BIOSCI BIOTECH BIOCH JI Biosci. Biotechnol. Biochem. PD JUN PY 2001 VL 65 IS 6 BP 1406 EP 1411 DI 10.1271/bbb.65.1406 PG 6 WC Biochemistry & Molecular Biology; Biotechnology & Applied Microbiology; Chemistry, Applied; Food Science & Technology SC Biochemistry & Molecular Biology; Biotechnology & Applied Microbiology; Chemistry; Food Science & Technology GA 447NX UT WOS:000169580300021 PM 11471744 ER PT J AU Han, CS Buckingham, J Meincke, LJ Doggett, NA AF Han, CS Buckingham, J Meincke, LJ Doggett, NA TI Vector for high-throughput sequencing: Construction and preparation with cyclic cut-ligation SO BIOTECHNIQUES LA English DT Article C1 Univ Calif Los Alamos Natl Lab, DOE Joint Genome Inst, Biosci Div, Los Alamos, NM 87545 USA. Univ Calif Los Alamos Natl Lab, DOE Joint Genome Inst, Ctr Human Genome Studies, Los Alamos, NM 87545 USA. RP Han, CS (reprint author), Univ Calif Los Alamos Natl Lab, DOE Joint Genome Inst, Biosci Div, Mail Stop M888, Los Alamos, NM 87545 USA. NR 3 TC 0 Z9 0 U1 0 U2 0 PU EATON PUBLISHING CO PI NATICK PA 154 E. CENTRAL ST, NATICK, MA 01760 USA SN 0736-6205 J9 BIOTECHNIQUES JI Biotechniques PD JUN PY 2001 VL 30 IS 6 BP 1208 EP + PG 2 WC Biochemical Research Methods; Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA 441WH UT WOS:000169252200004 PM 11414206 ER PT J AU Cullum, JK Ruehli, AE AF Cullum, JK Ruehli, AE TI Pseudospectra analysis, nonlinear eigenvalue problems, and studying linear systems with delays SO BIT NUMERICAL MATHEMATICS LA English DT Article DE pseudospectra; delay-differential-algebraic equations; linear systems; stability; passivity; time delays; VLSI circuits; nonlinear eigenvalue problems ID DIFFERENTIAL SYSTEMS; STABILITY; OPERATORS; MATRICES; MODELS AB Time delays occur naturally in many physical and social systems. Computer simulations of such systems require that models of these systems be stable, and perhaps even passive, if several such systems are to be joined together in the simulation. We present a visual procedure for studying the stability and passivity of such systems. This procedure uses ideas from pseudospectra analysis. It is applicable to systems of Linear, delay-differential-algebraic equations. There are no a priori restrictions on the types or sizes of the delays. No approximations to the original system are made. All approximations are confined to the grid used in the visualization procedure, and the procedure parallelizes readily. We apply this procedure to the study of the stability and passivity of proposed models for simulations of the behavior of currents and voltages in packaged VLSI interconnects (wires and planes) in computers. Simulations are required to verify that internal electromagnetic fields do not significantly delay or distort circuit signals. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. IBM Res, Thomas J Watson Res Ctr, Yorktown Hts, NY 10598 USA. EM cullumj@lanl.gov; ruehli@us.ibm.com NR 32 TC 5 Z9 5 U1 0 U2 1 PU SPRINGER PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0006-3835 EI 1572-9125 J9 BIT JI Bit PD JUN PY 2001 VL 41 IS 2 BP 265 EP 281 DI 10.1023/A:1021938406143 PG 17 WC Computer Science, Software Engineering; Mathematics, Applied SC Computer Science; Mathematics GA 450QU UT WOS:000169755200003 ER PT J AU Day, SM Bradley, CR AF Day, SM Bradley, CR TI Memory-efficient simulation of anelastic wave propagation SO BULLETIN OF THE SEISMOLOGICAL SOCIETY OF AMERICA LA English DT Article ID LOS-ANGELES BASIN; 3-DIMENSIONAL SIMULATION; FINITE-DIFFERENCES; HALF-SPACE; CONSTANT-Q; EARTHQUAKE; CALIFORNIA; VARIABLES; MOTIONS; SCHEME AB Realistic anelastic attenuation can be incorporated rigorously into finite difference and other numerical wave propagation methods using internal or memory variables. The main impediment to the realistic treatment of anelastic attenuation in 3D is the very large computational storage requirement imposed by the additional variables. We previously proposed an alternative to the conventional memory-variable formulation, the method of coarse-grain memory variables, and demonstrated its effectiveness in acoustic problems. We generalize this memory-efficient formulation to 3D anelasticity and describe a fourth-order, staggered-grid finite-different implementation. The anelastic coarse-grain method applied to plane wave propagation successfully simulates frequency-independent Q(P), and Q(S), Apparent Q values are constant to within 4% tolerance over approximately two decades in frequency and biased less than 4% from specified target values, This performance is comparable to that achieved previously for acoustic-wave propagation, and accuracy could be further improved by optimizing the memory-variable relaxation times and weights. For a given assignment of relaxation times and weights, the coarse-grain method provides an eight-fold reduction in the storage requirement for memory variables, relative to the conventional approach. The method closely approximates the wavenumber-integration solution for the response of an anelastic half-space to a shallow dislocation source, accurately calculating all phases including the surface-diffracted SP phase and the Rayleigh wave. The half-space test demonstrates that the wave field-averaging concept underlying the coarse-grain method is effective near boundaries and in the presence of evanescent waves. We anticipate that this method will also be applicable to unstructured grid methods, such as the finite-element method and the spectral-element method, although additional numerical testing will be required to establish accuracy in the presence of grid irregularity. The method is not effective at wavelengths equal to and shorter than 4 grid cell dimensions, where it produces anomalous scattering effects. This limitation could be significant for very high-order numerical schemes under some circumstances (i.e., whenever wavelengths as short as 4 grids are otherwise within the usable bandwidth of the scheme), but it is of no practical importance in our fourth-order finite-difference implementation. C1 San Diego State Univ, Dept Geol Sci, San Diego, CA 92182 USA. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Day, SM (reprint author), San Diego State Univ, Dept Geol Sci, San Diego, CA 92182 USA. NR 35 TC 69 Z9 70 U1 0 U2 1 PU SEISMOLOGICAL SOC AMER PI EL CERRITO PA PLAZA PROFESSIONAL BLDG, SUITE 201, EL CERRITO, CA 94530 USA SN 0037-1106 J9 B SEISMOL SOC AM JI Bull. Seismol. Soc. Amer. PD JUN PY 2001 VL 91 IS 3 BP 520 EP 531 DI 10.1785/0120000103 PG 12 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 446ZB UT WOS:000169543100010 ER PT J AU Vitek, JM Kozeschnik, E David, SA AF Vitek, JM Kozeschnik, E David, SA TI Simulating the ferrite-to-austenite transformation in stainless steel welds SO CALPHAD-COMPUTER COUPLING OF PHASE DIAGRAMS AND THERMOCHEMISTRY LA English DT Article; Proceedings Paper CT Annual Meeting of the Minerals-Metals-and-Materials-Society (TMS) CY FEB 12-15, 2001 CL NEW ORLEANS, LOUISIANA SP Minerals Metals Materials Soc ID CR-NI ALLOYS; SOLIDIFICATION; PHASE AB Under some conditions, the transformation of as-solidified ferrite to austenite in stainless steels has characteristics of a massive transformation. Calculations were carried out to determine if experimental evidence from Koseki of such a transformation could be modeled by a diffusion-controlled transformation. Two different conditions at the transformation interface were considered: ortho-equilibrium and para-equilibrium. Simulations solved the multi-component diffusion problem for various thermal conditions, including isothermal and continuous cooling conditions. It was found that neither interface condition could explain the experimental results of Koseki. The ortho-equilibrium interface condition resulted in transformation rates that were too slow. In addition, continuous cooling conditions led to non-uniform compositions, contradicting the experimental evidence. The para-equilibrium condition resulted in sufficiently fast transformation rates but the temperature of the transformation was considerably higher than that found experimentally. It is suggested that a condition of limited partitioning of substitutional solute elements at the interface could better explain the experimental results, but implementation of this condition at the interface is not possible with currently available simulation capabilities. C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. Graz Univ Technol, A-8010 Graz, Austria. RP Vitek, JM (reprint author), Oak Ridge Natl Lab, Bldg 4508,MS 6096, Oak Ridge, TN 37831 USA. NR 20 TC 6 Z9 6 U1 0 U2 2 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0364-5916 J9 CALPHAD JI Calphad-Comput. Coupling Ph. Diagrams Thermochem. PD JUN PY 2001 VL 25 IS 2 BP 217 EP 230 DI 10.1016/S0364-5916(01)00044-X PG 14 WC Thermodynamics; Chemistry, Physical; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Thermodynamics; Chemistry; Materials Science; Metallurgy & Metallurgical Engineering GA 486PV UT WOS:000171826900007 ER PT J AU Hu, JJ Smith, TR Miller, MS Mohrenweiser, HW Golden, A Case, LD AF Hu, JJ Smith, TR Miller, MS Mohrenweiser, HW Golden, A Case, LD TI Amino acid substitution variants of APE1 and XRCC1 genes associated with ionizing radiation sensitivity SO CARCINOGENESIS LA English DT Article ID BREAST-CANCER PATIENTS; BASE EXCISION-REPAIR; DNA-POLYMERASE BETA; APURINIC/APYRIMIDINIC ENDONUCLEASE; POLY(ADP-RIBOSE) POLYMERASE; CHROMOSOME STABILITY; HUMAN-CELLS; POLYMORPHISMS; DAMAGE; RADIOSENSITIVITY AB Although several variants of DNA repair genes have been identified, their functional significance has not been determined. Using samples collected from 135 cancer-free women, this study evaluated whether amino acid substitution variants of DNA repair genes contribute to ionizing radiation (IR) susceptibility as measured by prolonged cell cycle Gz delay. PCR-restriction fragment length polymorphism (RFLP) assays were used to determine four genotypes: X-ray repair cross complementing group 1 (XRCC1, exon 6, C/T, 194 Arg/Trp and exon 10, G/A, 399 Arg/Gln), XRCC group 3 (XRCC3, exon 7, C/T, 241 Thr/Met) and apurinic/apyrimidinic endonuclease 1 (APE1, exon 5, T/G, 148 Asp/Glu), Fluorescence-activated cell sorter (FACS) analysis was used to measure cell cycle delay, APE1 (exon 5) genotype was significantly associated with mitotic delay (P = 0.01), with the Glu/Glu genotype having prolonged delay compared with the other two genotypes. The mitotic delay index (mean +/- SD) in women with the APE1 codon 148 Asp/Asp, Asp/Glu and Glu/Glu genotypes was 30.95 +/- 10.15 (n = 49), 30.65 +/- 10.4 (n = 60) and 39.56 +/- 13.12 (n = 21), respectively, There was a significant interaction between family history (FH) and APE1 (exon 5) genotype (P = 0.007) as well as FH and XRCC1 (exon 10) genotype (P = 0.005) in mitotic delay, Lastly, prolonged cell cycle delay was significantly associated with number of variant alleles when APE1 Asp148Glu and XRCC1 Arg399Gln genotypes were evaluated in a four-level model (chi (2) for linear trend 10.9; P = 0.001), These results suggest that amino acid substitution variants of XRCC1 and APE1 may contribute to IR hypersensitivity. C1 Wake Forest Univ, Sch Med, Dept Canc Biol, Winston Salem, NC 27157 USA. Wake Forest Univ, Sch Med, Dept Publ Hlth Sci, Winston Salem, NC 27157 USA. Lawrence Livermore Natl Lab, Biol & Biotechnol Res Program, Livermore, CA 94550 USA. Georgetown Univ, Med Ctr, Lombardi Canc Ctr, Washington, DC 20007 USA. RP Hu, JJ (reprint author), Wake Forest Univ, Sch Med, Dept Canc Biol, Winston Salem, NC 27157 USA. EM jenhu@wfubmc.edu FU NCI NIH HHS [CA73629] NR 43 TC 254 Z9 267 U1 0 U2 2 PU OXFORD UNIV PRESS PI OXFORD PA GREAT CLARENDON ST, OXFORD OX2 6DP, ENGLAND SN 0143-3334 J9 CARCINOGENESIS JI Carcinogenesis PD JUN PY 2001 VL 22 IS 6 BP 917 EP 922 DI 10.1093/carcin/22.6.917 PG 6 WC Oncology SC Oncology GA 440JE UT WOS:000169171500012 PM 11375899 ER PT J AU Kane, RL Klein, DE AF Kane, RL Klein, DE TI Carbon sequestration: An option for mitigating global climate change SO CHEMICAL ENGINEERING PROGRESS LA English DT Article C1 US DOE, Off Planning & Environm Anal, Off Coal & Power Syst, Off Fossil Energy, Washington, DC 20585 USA. US DOE, Climate Challenge Program, Washington, DC USA. Twenty First Strategies, Mclean, VA USA. RP Kane, RL (reprint author), US DOE, Off Planning & Environm Anal, Off Coal & Power Syst, Off Fossil Energy, Washington, DC 20585 USA. NR 28 TC 5 Z9 6 U1 0 U2 4 PU AMER INST CHEMICAL ENGINEERS PI NEW YORK PA 3 PARK AVE, NEW YORK, NY 10016-5901 USA SN 0360-7275 J9 CHEM ENG PROG JI Chem. Eng. Prog. PD JUN PY 2001 VL 97 IS 6 BP 44 EP 52 PG 9 WC Engineering, Chemical SC Engineering GA 441ZL UT WOS:000169259400041 ER PT J AU Phillips, FM Stone, WD Fabryka-Martin, JT AF Phillips, FM Stone, WD Fabryka-Martin, JT TI An improved approach to calculating low-energy cosmic-ray neutron fluxes near the land/atmosphere interface SO CHEMICAL GEOLOGY LA English DT Article DE cosmogenic elements; exposure age; Cl-36; neutron methods; absolute age; cosmochemistry ID PRODUCTION-RATES; COSMOGENIC NUCLIDES; TERRESTRIAL ROCKS; LATHROP WELLS; CL-36; REEVALUATION; AGE AB Low-energy cosmic-ray neutrons play an important role in the production of the cosmogenic nuclides Cl-36 and Ca-41. Previous approaches to modeling the distribution of low-energy neutrons beneath the surface of the earth have derived the thermal neutrons directly from the high-energy neutron flux. We have improved on this model by deriving the thermal neutrons from the moderation of the epithermal neutron flux, and the epithermal neutrons from the fast neutron flux. Predictions from the improved model agree well with experimental measurements of thermal and epithermal neutron fluxes both above and below the land/atmosphere interface. Recalibration of the Cl-36 surface production parameters of Phillips et al. [Phillips, F.M., Zreda, M.G., Flinsch, M.R., Elmore, D., Sharma, P., 1996. A reevaluation of cosmogenic Cl-36 production rates in terrestrial rocks. Geophys. Res. Lett., 23, pp. 949-952), incorporating the new approach to simulating the low-energy neutron fluxes, yielded the following values: P-s,P-Ca 66.8 atoms (g Ca)(-1) year(-1), P-s,P-K 137 atoms (g K)(-1) year(-1), and P-f(0) 626 neutrons (g air)(-1) year(-1) (this updated calibration also includes mugenic Cl-36 production, based on independent work). Comparison of ages of three groups of samples from sites not included in the calibration data set with independently determined ages gave an average absolute error of 6.6% for all three data sets and coefficients of variation among the samples in the groups ranging from 5% to 14%. (C) 2001 Elsevier Science B.V. All rights reserved. C1 New Mexico Tech, Earth & Environm Sci Dept, Socorro, NM 87801 USA. New Mexico Tech, Dept Math, Socorro, NM 87801 USA. Univ Calif Los Alamos Natl Lab, Grp E ET, Los Alamos, NM 87545 USA. RP Phillips, FM (reprint author), New Mexico Tech, Earth & Environm Sci Dept, Socorro, NM 87801 USA. NR 22 TC 121 Z9 122 U1 1 U2 9 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0009-2541 J9 CHEM GEOL JI Chem. Geol. PD JUN 1 PY 2001 VL 175 IS 3-4 BP 689 EP 701 DI 10.1016/S0009-2541(00)00329-6 PG 13 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 432GL UT WOS:000168683800030 ER PT J AU Bertsch, PM Hunter, DB AF Bertsch, PM Hunter, DB TI Applications of synchrotron-based X-ray microprobes SO CHEMICAL REVIEWS LA English DT Review ID NEAR-EDGE STRUCTURE; MONTE-CARLO-SIMULATION; ADVANCED LIGHT-SOURCE; INTERPLANETARY DUST PARTICLES; MATERIALS SCIENCE SPECTROMICROSCOPY; FINE-STRUCTURE SPECTROSCOPY; PLATE GENERATED MICROPROBE; TRISTAN ACCUMULATION RING; FRESNEL MULTILAYER LENS; TRACE-ELEMENT CONTENTS C1 Univ Georgia, Savannah River Ecol Lab, Adv Analyt Ctr Environm Sci, Aiken, SC 29802 USA. RP Bertsch, PM (reprint author), Univ Georgia, Savannah River Ecol Lab, Adv Analyt Ctr Environm Sci, Drawer E, Aiken, SC 29802 USA. EM bertsch@srel.edu NR 309 TC 97 Z9 97 U1 0 U2 29 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0009-2665 J9 CHEM REV JI Chem. Rev. PD JUN PY 2001 VL 101 IS 6 BP 1809 EP 1842 DI 10.1021/cr990070s PG 34 WC Chemistry, Multidisciplinary SC Chemistry GA 444AK UT WOS:000169375600010 PM 11710000 ER PT J AU Millburn, JE Mitchell, JF AF Millburn, JE Mitchell, JF TI Impact of oxygen partial pressure on the Ruddlesden-Popper series Nd2-2xSr1+2xMn2O7: Oxygen vacancy formation and ordering SO CHEMISTRY OF MATERIALS LA English DT Article ID GIANT MAGNETORESISTANCE; MANGANESE OXIDES; NEUTRON-DIFFRACTION; MAGNETIC-PROPERTIES; CRYSTAL-STRUCTURE; MANGANITES; STOICHIOMETRY; TRANSITION; COMPOUND; STATE AB The phase diagram of the Nd2-2xSr1+2xMn2O7+delta n = 2 Ruddlesden-Popper series has been investigated as a function of composition and oxygen partial pressure at 1400 degreesC. The regions of phase stability for 0.10 less than or equal to x less than or equal to 0.70 and 10(-6) less than or equal to p(O-2)/atm less than or equal to 1.0 have been mapped out and a systematic relationship between x and oxygen partial pressure established. At high p(O-2) (near 1 atm) the upper solubility limit is fixed by an average Mn oxidation state of +3.5, while the lower limit of stability is a strong function of p(O-2). Phases synthesized at low p(Oa) are associated with the introduction of oxygen vacancies that can be filled at low temperature to yield metastable phases with formal Mn oxidation states beyond +3.5. The oxygen vacancy structures are highly dependent on the Nd/Sr ratio, with the location of the vacancies changing from in-plane to axial as a function of both x and temperature. Systematic study of the Mn-O bonding framework reveals a subtle dependence of the crystal structure on both the Mn oxidation state and vacancy location. The unusual crystal chemistry of these phases suggests a more general synthetic technique for accessing layered manganite phases as potential CMR candidates. C1 Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. RP Mitchell, JF (reprint author), Argonne Natl Lab, Div Mat Sci, 9700 S Cass Ave, Argonne, IL 60439 USA. NR 28 TC 5 Z9 6 U1 0 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0897-4756 J9 CHEM MATER JI Chem. Mat. PD JUN PY 2001 VL 13 IS 6 BP 1957 EP 1966 DI 10.1021/cm990809e PG 10 WC Chemistry, Physical; Materials Science, Multidisciplinary SC Chemistry; Materials Science GA 445TD UT WOS:000169473900005 ER PT J AU Bonhomme, F Thoma, SG Rodriguez, MA Nenoff, TM AF Bonhomme, F Thoma, SG Rodriguez, MA Nenoff, TM TI Ga-4(PO4)(4)F center dot N2C7H11 center dot 1/2H(2)O: A three-dimensional open framework with 12-membered pores and "bowl-shaped" building units SO CHEMISTRY OF MATERIALS LA English DT Article ID OXYFLUORINATED MICROPOROUS COMPOUNDS; RAY STRUCTURAL DETERMINATION; CRYSTAL-STRUCTURE; FLUORINATED GALLOPHOSPHATE; MOLECULAR-SIEVES; FLUOROGALLOPHOSPHATE; METHYLAMINE; SOLIDS AB Ga-4(PO4)(4)F .N2C7H11.1/2H(2)O was prepared solvothermally in pure form using 4-(dimethyl-amino)pyridine (4-DMAP) as a template in various solvents (pyridine, pyridine/water, and ethylene glycol) within a broad reaction temperature range (115-180 degreesC). Its structure was determined from X-ray single-crystal diffraction data at low temperature (-105 degreesC). Ga-4-(PO4)(4)F .N2C7H11.1/2H(2)O crystallizes in the monoclinic space group C2/c, witll a = 22.093(4) Angstrom, b = 13.904(2) Angstrom, c = 14.230(2) Angstrom, beta = 98.431.(3)degrees, V = 4324 Angstrom (3), and Z = 8. Its three-dimensional framework is composed of novel distorted "bowl-shaped" octameric double 4-ring units, which are built up by corner-sharing PO4 and GaO4 tetrahedra and GaO4F trigonal bipyramids. The structure consists of a pseudohexagonal array of cylindrical 12-membered pores running parallel to the c axis hosting the protonated 4-DMAP molecules. These pores are interconnected along the b axis through double 3-ring windows. The framework remains stable up to 300 degreesC under oxygen. C1 Sandia Natl Labs, Environm Monitoring & Characterizat Dept, Albuquerque, NM 87185 USA. Sandia Natl Labs, Mat Characterizat Dept, Albuquerque, NM 87185 USA. RP Nenoff, TM (reprint author), Sandia Natl Labs, Environm Monitoring & Characterizat Dept, POB 5800, Albuquerque, NM 87185 USA. NR 38 TC 19 Z9 19 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0897-4756 J9 CHEM MATER JI Chem. Mat. PD JUN PY 2001 VL 13 IS 6 BP 2112 EP 2117 DI 10.1021/cm000971d PG 6 WC Chemistry, Physical; Materials Science, Multidisciplinary SC Chemistry; Materials Science GA 445TD UT WOS:000169473900026 ER PT J AU Jones, BR Varughese, PA Olejniczak, I Pigos, JM Musfeldt, JL Landee, CP Turnbull, MM Carr, GL AF Jones, BR Varughese, PA Olejniczak, I Pigos, JM Musfeldt, JL Landee, CP Turnbull, MM Carr, GL TI Vibrational properties of the one-dimensional, S=1/2, heisenberg antiferromagnet copper pyrazine dinitrate SO CHEMISTRY OF MATERIALS LA English DT Article ID DOPED CUPRATE SUPERCONDUCTORS; PHASE-DIAGRAM; CRYSTAL; ZN; MAGNETIZATION; RESONANCE; COMPLEXES; SYMMETRY; MODES; NI AB We report the temperature-dependent infrared spectra of pure, deuterated, Zn-doped, and 2,6-dimethyl-substituted samples of the S = 1/2, one-dimensional Quantum Heisenberg Antiferromagnet (QHAF) copper pyrazine dinitrate (Cu(C4H4N2)(NO3)(2)) Of the more than 100 vibrational modes observed in the spectra, nearly one-third of them unexpectedly soften throughout the temperature range of investigation (300-5 K). We discuss the temperature dependence of the vibrational spectra in terms of several different models for mode softening. On the basis of detailed structural information and a comparison of the infrared spectra between pure copper pyrazine dinitrate and its chemically modified relatives, we conclude that the unusual softening observed in this low-dimensional molecular magnet is due to enhanced interchain hydrogen bonding with decreasing temperature. C1 SUNY Binghamton, Dept Chem, Binghamton, NY 13902 USA. Clark Univ, Dept Phys, Worcester, MA 01610 USA. Clark Univ, Carlson Sch Chem, Worcester, MA 01610 USA. Brookhaven Natl Lab, Natl Synchtrotron Light Source, Upton, NY 11973 USA. RP Jones, BR (reprint author), SUNY Binghamton, Dept Chem, Binghamton, NY 13902 USA. OI Turnbull, Mark/0000-0002-0232-8224 NR 51 TC 18 Z9 18 U1 1 U2 8 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0897-4756 J9 CHEM MATER JI Chem. Mat. PD JUN PY 2001 VL 13 IS 6 BP 2127 EP 2134 DI 10.1021/cm001412+ PG 8 WC Chemistry, Physical; Materials Science, Multidisciplinary SC Chemistry; Materials Science GA 445TD UT WOS:000169473900028 ER PT J AU Nozaki, A McGrail, BP Fayer, MJ Saripalli, KP AF Nozaki, A McGrail, BP Fayer, MJ Saripalli, KP TI A coupled mechanical-chemical stability analysis for a low activity waste disposal facility at the Hanford site SO COMPUTERS & STRUCTURES LA English DT Article DE waste disposal; corrosion; glass; mechanical instability; modeling; performance assessment ID TUFF; ROCK AB The steel container and vitrified waste materials that comprise waste packages planned for subsurface disposal of low-activity wastes at Hanford are subject to corrosion processes that generate a net volumetric expansion. Stress state and deformation in an idealized disposal system were modeled as a function of expansion pressure. Potential expansion pressures from glass and steel corrosion product formation were estimated and compared with the computed critical inner pressures (P-c) required to induce mechanical instability. Even a moderate degree of steel corrosion was found to generate internal pressures significantly above Pc. However, a kinetics analysis suggests that between 270 and 2500 years would be required before the P-c is exceeded. (C) 2001 Elsevier Science Ltd. All rights reserved. C1 Pacific NW Natl Lab, Dept Appl Geol & Geochem, Richland, WA 99352 USA. Kyushu Elect Power Co Inc, Civil Engn Grp, Minami Ku, Fukuoka 815, Japan. Pacific NW Natl Lab, Dept Hydrol, Richland, WA 99352 USA. RP McGrail, BP (reprint author), Pacific NW Natl Lab, Dept Appl Geol & Geochem, POB 999,MS K6-81, Richland, WA 99352 USA. NR 25 TC 2 Z9 2 U1 0 U2 2 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0045-7949 J9 COMPUT STRUCT JI Comput. Struct. PD JUN PY 2001 VL 79 IS 16 BP 1503 EP 1516 DI 10.1016/S0045-7949(01)00028-1 PG 14 WC Computer Science, Interdisciplinary Applications; Engineering, Civil SC Computer Science; Engineering GA 470FN UT WOS:000170859900006 ER PT J AU Sim, A Nordberg, H Bernardo, LM Shoshani, A Rotem, D AF Sim, A Nordberg, H Bernardo, LM Shoshani, A Rotem, D TI Experience with using CORBA to implement a file caching coordination system SO CONCURRENCY AND COMPUTATION-PRACTICE & EXPERIENCE LA English DT Article DE CORBA; storage management; mass storage system; file caching AB We describe our experience with using several CORBA products to interconnect the software modules of a fairly complex system for file caching coordination from a tertiary storage. The application area that the system was designed for is High Energy and Nuclear Physics (HENP), In this application area, the volume of data reaches hundreds of terabytes per year and therefore it is impractical to store them on disk systems. Rather the data are organized into large files and stored on robotic tape systems that are managed by some Mass Storage System (MSS), The role of the Storage Access Coordination System (STACS) that we developed is to manage the caching of files from the MSS to a large disk cache that is shared by multiple HENP analysis programs, The system design involved multiple components developed by different people at different sites and the modules could potentially be distributed as well. In this paper we describe the architecture and implementation of STAGS, emphasizing the inter-module communication requirements. We describe the use of CORBA interfaces between system components, and our experience with using multi-threaded CORBA and using hundreds of concurrent CORBA connections. STAGS development was recently completed and is being incorporated in an operational environment that started to produce data in the summer of 2000 [1]. Copyright (C) 2001 John Wiley & Sons, Ltd. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Natl Energy Res Sci Comp Div, Berkeley, CA 94720 USA. RP Sim, A (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Natl Energy Res Sci Comp Div, Berkeley, CA 94720 USA. NR 9 TC 0 Z9 0 U1 0 U2 0 PU JOHN WILEY & SONS LTD PI W SUSSEX PA BAFFINS LANE CHICHESTER, W SUSSEX PO19 1UD, ENGLAND SN 1532-0626 J9 CONCURR COMP-PRACT E JI Concurr. Comput.-Pract. Exp. PD JUN PY 2001 VL 13 IS 7 BP 605 EP 619 DI 10.1002/cpe.561 PG 15 WC Computer Science, Software Engineering; Computer Science, Theory & Methods SC Computer Science GA 449PM UT WOS:000169695600005 ER PT J AU Glass, RJ Rajaram, H Nicholl, MJ Detwiler, RL AF Glass, RJ Rajaram, H Nicholl, MJ Detwiler, RL TI The interaction of two fluid phases in fractured media SO CURRENT OPINION IN COLLOID & INTERFACE SCIENCE LA English DT Review DE fractures; two-phase flow; transport; phase dissolution; percolation ID SATURATED POROUS-MEDIA; ROUGH-WALLED FRACTURES; ROCK FRACTURES; TRACER DISPERSION; SINGLE FRACTURE; RELATIVE PERMEABILITY; INVASION PERCOLATION; REYNOLDS-EQUATION; 2-PHASE FLOW; CAPILLARY-PRESSURE AB In fractured porous media, interactions between immiscible fluid phases within the fractures place a critical control on system behavior. A key component of the interactions is the geometry, or structure, of the respective phases. Over the past 10 years, process-based experiments have greatly increased our understanding of phase structure development within individual fractures. In the past 2 years, new calculational models that incorporate some of this understanding have further demonstrated the influence of phase structure on flow and transport within the phases, and inter-phase mass transport. These computational models can now be applied to consider the efficacy and parameterization of constitutive relations for a subset of two-phase situations. Full understanding of the morphology, connectivity, and temporal dynamics of phase structure in rough-walled fractures is yet to be developed, and is a promising area for further research. (C) 2001 Elsevier Science Ltd. All rights reserved. C1 Sandia Natl Labs, Flow Visualization & Proc Lab, Albuquerque, NM 87185 USA. Univ Colorado, Dept Civil Environm & Architectural Engn, Boulder, CO 80309 USA. Univ Idaho, Dept Mat Met Min & Geol Engn, Moscow, ID 83844 USA. RP Glass, RJ (reprint author), Sandia Natl Labs, Flow Visualization & Proc Lab, POB 5800, Albuquerque, NM 87185 USA. RI Detwiler, Russell/C-3228-2008 OI Detwiler, Russell/0000-0002-7693-9271 NR 65 TC 18 Z9 18 U1 1 U2 10 PU ELSEVIER SCIENCE LONDON PI LONDON PA 84 THEOBALDS RD, LONDON WC1X 8RR, ENGLAND SN 1359-0294 J9 CURR OPIN COLLOID IN JI Curr. Opin. Colloid Interface Sci. PD JUN PY 2001 VL 6 IS 3 BP 223 EP 235 DI 10.1016/S1359-0294(01)00086-3 PG 13 WC Chemistry, Physical SC Chemistry GA 453XP UT WOS:000169943700006 ER PT J AU Keegstra, K Raikhel, N AF Keegstra, K Raikhel, N TI Plant glycosyltransferases SO CURRENT OPINION IN PLANT BIOLOGY LA English DT Review ID CELL-WALL; ARABIDOPSIS-THALIANA; MOLECULAR-CLONING; UDP-GLUCOSE; BIOCHEMICAL-CHARACTERIZATION; O-GLUCOSYLTRANSFERASE; FUCOSYL-TRANSFERASE; LAST STEP; BIOSYNTHESIS; EXPRESSION AB Glycosyltransferases are involved in the biosyntheses of cell-wall polysaccharides, the addition of N-linked glycans to glycoproteins, and the attachment of sugar moieties to various small molecules such as hormones and flavonoids. In the past two years, substantial progress has been made in the identification and cloning of genes that encode glycosyltransferases. Moreover, analysis of the recently completed Arabidopsis genome sequence indicates the existence of several hundred additional genes encoding putative glycosyltransferases. C1 Michigan State Univ, DOE Plant Res Lab, E Lansing, MI 48824 USA. Michigan State Univ, Dept Biochem, E Lansing, MI 48824 USA. RP Keegstra, K (reprint author), Michigan State Univ, DOE Plant Res Lab, E Lansing, MI 48824 USA. EM keegstra@msu.edu; nraikhel@msu.edu NR 43 TC 87 Z9 95 U1 0 U2 8 PU CURRENT BIOLOGY LTD PI LONDON PA 84 THEOBALDS RD, LONDON WC1X 8RR, ENGLAND SN 1369-5266 J9 CURR OPIN PLANT BIOL JI Curr. Opin. Plant Biol. PD JUN PY 2001 VL 4 IS 3 BP 219 EP 224 DI 10.1016/S1369-5266(00)00164-3 PG 6 WC Plant Sciences SC Plant Sciences GA 429CY UT WOS:000168499500008 PM 11312132 ER PT J AU Gorbarenko, SA Southon, J AF Gorbarenko, SA Southon, J TI Stratigraphy of the Akademii nauk rise sediments and Late Pleistocene hydrology of the Sea of Okhotsk SO DOKLADY EARTH SCIENCES LA English DT Article ID PACIFIC C1 Russian Acad Sci, Ilichev Pacific Oceanol Inst, Far E Div, Vladivostok 690041, Russia. Lawrence Livermore Natl Lab, AMS Ctr, Livermore, CA 94551 USA. RP Gorbarenko, SA (reprint author), Russian Acad Sci, Ilichev Pacific Oceanol Inst, Far E Div, Baltiiskaya Ul 43, Vladivostok 690041, Russia. NR 15 TC 0 Z9 0 U1 0 U2 0 PU INTERPERIODICA PI BIRMINGHAM PA PO BOX 1831, BIRMINGHAM, AL 35201-1831 USA SN 1028-334X J9 DOKL EARTH SCI JI Dokl. Earth Sci. PD JUN-JUL PY 2001 VL 379 IS 5 BP 597 EP 600 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 458UH UT WOS:000170212600026 ER PT J AU Jang, YI Neudecker, BJ Dudney, NJ AF Jang, YI Neudecker, BJ Dudney, NJ TI Lithium diffusion in LixCoO2 (0.45 < x < 0.7) intercalation cathodes SO ELECTROCHEMICAL AND SOLID STATE LETTERS LA English DT Article ID ELECTROCHEMICAL PROPERTIES; TRANSPORT-PROPERTIES; ELECTRODE MATERIALS; LICOO2 ELECTRODES; TRANSITION; BATTERIES; CELLS; NMR AB Mass transport and thermodynamic properties of LixCoO2 were studied by the potentiostatic intermittent titration technique (PITT). We determined the chemical diffusion coefficient ((D) over tilde (Li)) and the thermodynamic factor (Theta) of Li in the region 0.45 < x < 0.7, where LixCoO2 exists as a single phase having either a rhombohedral or a monoclinic structure. Solid-state thin-film batteries were used in order to ensure a well-defined diffusion geometry. Both (D) over tilde (Li) and Theta have minima at the phase boundaries of the Li vacancy ordered phase Li0.5CoO2. The self-diffusion coefficient of Li (D-Li) has a minimum at x = 0.5 associated with the Li vacancy ordering. As the degree of ordering increases, nonmonotonic variations of (D) over tilde (Li), Theta, and D-Li become more pronounced when approaching x = 0.5 in LixCoO2. (C) 2001 The Electrochemical Society. C1 Oak Ridge Natl Lab, Div Solid State, Oak Ridge, TN 37831 USA. RP Jang, YI (reprint author), Oak Ridge Natl Lab, Div Solid State, POB 2008, Oak Ridge, TN 37831 USA. RI Dudney, Nancy/I-6361-2016 OI Dudney, Nancy/0000-0001-7729-6178 NR 33 TC 109 Z9 110 U1 9 U2 83 PU ELECTROCHEMICAL SOC INC PI PENNINGTON PA 65 SOUTH MAIN STREET, PENNINGTON, NJ 08534 USA SN 1099-0062 J9 ELECTROCHEM SOLID ST JI Electrochem. Solid State Lett. PD JUN PY 2001 VL 4 IS 6 BP A74 EP A77 DI 10.1149/1.1368717 PG 4 WC Electrochemistry; Materials Science, Multidisciplinary SC Electrochemistry; Materials Science GA 422FC UT WOS:000168107000004 ER PT J AU Wang, YF Guo, XD Greenbaum, S Liu, J Amine, K AF Wang, YF Guo, XD Greenbaum, S Liu, J Amine, K TI Solid electrolyte interphase formation on lithium-ion electrodes - A Li-7 nuclear magnetic resonance study SO ELECTROCHEMICAL AND SOLID STATE LETTERS LA English DT Article ID BATTERIES; GRAPHITE AB Lithium-7 nuclear magnetic resonance (NMR) measurements on electrodes from aged and cycled lithium-ion batteries have been performed. The active cathode material was LiNi0.8Co0.2O2, and the anode consisted of a commercial graphite blend. Cells were aged by storage under 60% charge at elevated temperatures. One of the primary failure mechanisms believed to occur in these cells is the formation of a passivating layer on the positive electrode that eventually leads to loss of electrical contact between active cathode particles. The NMR spectra demonstrate buildup of a solid electrolyte interphase (SEI), characterized by a relatively featureless absorption centered at 0 ppm (aqueous LiCl reference). By comparing relative integrated spectral intensities of the SEI and the main cathode signal at 580 ppm, the SEI growth can be quantitatively monitored by NMR methods. (C) 2001 The Electrochemical Society. C1 CUNY Hunter Coll, Dept Phys & Astron, New York, NY 10021 USA. Argonne Natl Lab, Div Chem Technol, Argonne, IL 60439 USA. RP Wang, YF (reprint author), CUNY Hunter Coll, Dept Phys & Astron, New York, NY 10021 USA. RI Amine, Khalil/K-9344-2013 NR 9 TC 61 Z9 63 U1 3 U2 34 PU ELECTROCHEMICAL SOC INC PI PENNINGTON PA 65 SOUTH MAIN STREET, PENNINGTON, NJ 08534 USA SN 1099-0062 J9 ELECTROCHEM SOLID ST JI Electrochem. Solid State Lett. PD JUN PY 2001 VL 4 IS 6 BP A68 EP A70 DI 10.1149/1.1368716 PG 3 WC Electrochemistry; Materials Science, Multidisciplinary SC Electrochemistry; Materials Science GA 422FC UT WOS:000168107000002 ER PT J AU Zhang, XR Pugh, JK Ross, PN AF Zhang, XR Pugh, JK Ross, PN TI Evidence for epoxide formation from the electrochemical reduction of ethylene carbonate SO ELECTROCHEMICAL AND SOLID STATE LETTERS LA English DT Article ID GRAPHITE; LITHIUM; 2R,5R-DIHYDROXYMETHYL-3R,4R-DIHYDROXYPYRROLIDINE; POLYMERIZATION; INTERCALATION; ELECTROLYTE; BATTERIES; LAYER AB It is now generally agreed that the electrochemical reduction of ethylene carbonate (EC) plays an important role in the formation of an effective solid electrolyte interface layer on the carbon anode in lithium-ion cells. However, neither the composition of this layer nor the reaction pathways involved in its formation have been clearly established. We report reflectance infrared spectra from a glassy carbon electrode surface after EC/tetrahydrofuran electrolyte reduction that is unlike any other we have seen in the literature. The spectrum has its strong absorption peak at 838 cm(-1), and this feature is clearly shown not to be from the monoethylcarbonate lithium salt. Ethylene oxide is suggested as a possible, but not exclusive, reduction product. The suggested reaction pathway is an electrochemical-chemical sequence, electrochemical reduction of water to form hydroxide, and hydroxide addition to form ethylene oxide and lithium bicarbonate. (C) 2001 The Electrochemical Society. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Environm Energy Technol Div, Berkeley, CA 94720 USA. RP Zhang, XR (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Environm Energy Technol Div, Berkeley, CA 94720 USA. NR 22 TC 11 Z9 14 U1 1 U2 7 PU ELECTROCHEMICAL SOC INC PI PENNINGTON PA 65 SOUTH MAIN STREET, PENNINGTON, NJ 08534 USA SN 1099-0062 J9 ELECTROCHEM SOLID ST JI Electrochem. Solid State Lett. PD JUN PY 2001 VL 4 IS 6 BP A82 EP A84 DI 10.1149/1.1371252 PG 3 WC Electrochemistry; Materials Science, Multidisciplinary SC Electrochemistry; Materials Science GA 422FC UT WOS:000168107000006 ER PT J AU Li, X Young, DL Moutinho, H Yan, Y Narayanswamy, C Gessert, TA Coutts, TJ AF Li, X Young, DL Moutinho, H Yan, Y Narayanswamy, C Gessert, TA Coutts, TJ TI Properties of CdO thin films produced by chemical vapor deposition SO ELECTROCHEMICAL AND SOLID STATE LETTERS LA English DT Article ID CADMIUM-OXIDE FILMS; ELECTRICAL-PROPERTIES; SPRAY-PYROLYSIS; TRANSPARENT; DEVICES AB The properties of CdO films formed by low-pressure chemical vapor deposition were investigated as a function of deposition temperatures from 150-450 degreesC. Atomic force microscopy, X-ray diffraction, and transmission electron microscopy revealed that the grain size, bulk crystallinity, and intragrain quality all improved with increasing temperature. Spectrophotometry showed that the optical bandgap decreased from 3.10 to 2.35 eV with increasing deposition temperature, whereas Hall measurements indicated that carrier concentration decreased from mid 10(20) to low 10(19) cm(-3). Over the same range of temperature, the mobility increased from similar to6 to 216 cm(2) V-1 s(-1), the latter being the highest value ever achieved for CdO in any form. The high mobility achieved at increased deposition temperature was due partly to a reduction in the effective mass of carriers but mainly to an increase in their relaxation time associated with improved crystallinity. The optical and Hall measurements suggest that the higher optical bandgap for low deposition temperature is likely due to a Moss-Burstein shift, from which the reduced effective mass was estimated as approximately 0.11 m(e). A novel charge-transport method was used to determine the density-of-states effective mass of electrons. This mass increased from 0.14-0.18 m(e) with carrier concentration. Using this range of values and the reduced effective mass, we calculated that the approximate value of the density-of-states valence-band effective mass is 0.28-0.51 m(e). (C) 2001 The Electrochemical Society. C1 Natl Renewable Energy Lab, Golden, CO 80401 USA. RP Li, X (reprint author), Natl Renewable Energy Lab, Golden, CO 80401 USA. NR 18 TC 33 Z9 33 U1 1 U2 6 PU ELECTROCHEMICAL SOC INC PI PENNINGTON PA 65 SOUTH MAIN STREET, PENNINGTON, NJ 08534 USA SN 1099-0062 J9 ELECTROCHEM SOLID ST JI Electrochem. Solid State Lett. PD JUN PY 2001 VL 4 IS 6 BP C43 EP C46 DI 10.1149/1.1369216 PG 4 WC Electrochemistry; Materials Science, Multidisciplinary SC Electrochemistry; Materials Science GA 422FC UT WOS:000168107000009 ER PT J AU Vogel, JS Grant, PG Buchholz, BA Dingley, K Turteltaub, KW AF Vogel, JS Grant, PG Buchholz, BA Dingley, K Turteltaub, KW TI Attomole quantitation of protein separations with accelerator mass spectrometry SO ELECTROPHORESIS LA English DT Review DE protein; proteome; quantitation; radioisotope; accelerator mass spectrometry; review ID 2-DIMENSIONAL GEL-ELECTROPHORESIS; ADDUCT FORMATION; FOLIC-ACID; IDENTIFICATION; BINDING; METABOLISM; HUMANS; ADULT; AMS AB Quantification of specific proteins depends on separation by chromatography or electrophoresis followed by chemical detection schemes such as staining and fluorophore adhesion. Chemical exchange of short-lived isotopes, particularly sulfur, is also prevalent despite the inconveniences of counting radioactivity. Physical methods based on isotopic and elemental analyses offer highly sensitive protein quantitation that has linear response over wide dynamic ranges and is independent of protein conformation. Accelerator mass spectrometry quantifies long-lived isotopes such as C-14 to subattomole sensitivity, We quantified protein interactions with small molecules such as toxins, vitamins, and natural biochemicals at precisions of 1-5%. Micro-proton induced X-ray emission quantifies elemental abundances in separated metalloprotein samples to nanogram amounts and is capable of quantifying phopsphorylated loci in gels. Accelerator-based quantitation is a possible tool for quantifying the genome translation into proteome. C1 Univ Calif Lawrence Livermore Natl Lab, Ctr Accelerator Mass Spectrometry, Livermore, CA 94551 USA. RP Vogel, JS (reprint author), Univ Calif Lawrence Livermore Natl Lab, Ctr Accelerator Mass Spectrometry, 7000 E Ave,L-397, Livermore, CA 94551 USA. RI Buchholz, Bruce/G-1356-2011 FU NCI NIH HHS [CA055861]; NCRR NIH HHS [P41 RR013461, RR013461]; NIEHS NIH HHS [ES009690] NR 36 TC 17 Z9 18 U1 1 U2 8 PU WILEY-V C H VERLAG GMBH PI BERLIN PA PO BOX 10 11 61, D-69451 BERLIN, GERMANY SN 0173-0835 J9 ELECTROPHORESIS JI Electrophoresis PD JUN PY 2001 VL 22 IS 10 BP 2037 EP 2045 DI 10.1002/1522-2683(200106)22:10<2037::AID-ELPS2037>3.0.CO;2-8 PG 9 WC Biochemical Research Methods; Chemistry, Analytical SC Biochemistry & Molecular Biology; Chemistry GA 451GA UT WOS:000169791700022 PM 11465504 ER PT J AU Driessen, BJ Kotulski, JD AF Driessen, BJ Kotulski, JD TI Predicting computer run-time for the Barnes-Hut multipole method for electromagnetic scattering SO ENGINEERING ANALYSIS WITH BOUNDARY ELEMENTS LA English DT Article DE multipole expansion; tree; Barnes-Hut; matrix-vector multiply; computer run-time ID ALGORITHM AB This paper presents a novel simple methodology for quickly predicting and optimizing computer run-time for the Barnes-Hut multipole method for boundary element electromagnetic scattering problems. The methodology is easily extended to other multipole methods (e.g. Greengard-Rokhlin) and to other physics. The novel idea is to simply count the number of element-cell interactions, number of direct element-element interactions, and the number of cell multipole expansion creations teach expansion weighted by the number of elements in the cell), and then finally combine these three results with the associated unit costs to obtain the total computer run-time to perform a single matrix-vector multiply. By counting operations instead of actually performing them, the time to predict the computer run-time is orders of magnitude smaller than the time to actually perform the associated calculations. This new approach allows for very quick optimization of parameters, such as the maximum number of elements in a final generation cell of the tree. Numerical examples are presented herein in which the rate of return (time saved over time spent finding optimal parameter values) is significantly more than two orders of magnitude. (C) 2001 Elsevier Science Ltd. All rights reserved. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Driessen, BJ (reprint author), Sandia Natl Labs, POB 5800,MS 0847, Albuquerque, NM 87185 USA. NR 4 TC 0 Z9 0 U1 0 U2 0 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0955-7997 J9 ENG ANAL BOUND ELEM JI Eng. Anal. Bound. Elem. PD JUN PY 2001 VL 25 IS 6 BP 461 EP 465 DI 10.1016/S0955-7997(01)00050-9 PG 5 WC Engineering, Multidisciplinary; Mathematics, Interdisciplinary Applications SC Engineering; Mathematics GA 445WN UT WOS:000169481700007 ER PT J AU Kim, C Zhou, QH Deng, BL Thornton, EC Xu, HF AF Kim, C Zhou, QH Deng, BL Thornton, EC Xu, HF TI Chromium(VI) reduction by hydrogen sulfide in aqueous media: Stoichiometry and kinetics SO ENVIRONMENTAL SCIENCE & TECHNOLOGY LA English DT Article ID IN-SITU REMEDIATION; CHROMATE REDUCTION; FERROUS IRON; CR(VI); OXIDATION; BIOTITE; SAMPLES; SOILS; ACID; TRANSFORMATIONS AB The objective of this work was to investigate the reaction stoichiometry, kinetics, and mechanism for Cr(VI) reduction by hydrogen sulfide in the aqueous phase. Batch experiments with excess [Cr(VI)] over [H2S](inverted perpendicular) indicated that the molar amount of sulfide required for the reduction of 1 M Cr(VI) was 1.5, suggesting the following stoichiometry: 2CrO(4)(2-) + 3H(2)S + 4H(+) --> 2Cr(OH)(3)(s) + 3S(s) + 2H(2)O. Further study with transmission electron microscopy (TEM) and energy-dispersive X-ray spectroscopy (EDS) confirmed that chromium hydroxide and elemental sulfur were the stable products. The kinetics of Cr(VI) reduction by hydrogen sulfide was measured under various initial concentrations of Cr(VI) and sulfide as well as pH values controlled by HEPES, phosphate, and berate buffers. Results showed that the overall reaction was second-order, i.e., first-order with respect to Cr(VI):and first-order to sulfide. The reaction rate increased as pH was decreased, and the pH dependence correlated well with the fraction of fully protonated sulfide (H2S) in the pH range of 6.5-10. The nature of buffers did not influence the reaction rate significantly in the homogeneous system. The reaction kinetics could be interpreted by a three-step mechanism: formation of an inner-sphere chromate-sulfide intermediate complex (((H2O4CrS)-S-VI)(2-)), intramolecular electron transfer to form Cr(IV) species, and subsequent fast reactions leading to Cr(III). C1 New Mexico Inst Min & Technol, Dept Environm Engn, Socorro, NM 87801 USA. Pacific NW Natl Lab, Field Hydrol & Chem Grp, Richland, WA 99352 USA. Univ New Mexico, Dept Earth & Planetary Sci, Albuquerque, NM 87131 USA. RP Deng, BL (reprint author), New Mexico Inst Min & Technol, Dept Environm Engn, Socorro, NM 87801 USA. OI Deng, Baolin/0000-0001-6569-1808 NR 42 TC 143 Z9 152 U1 6 U2 58 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0013-936X J9 ENVIRON SCI TECHNOL JI Environ. Sci. Technol. PD JUN 1 PY 2001 VL 35 IS 11 BP 2219 EP 2225 DI 10.1021/es0017007 PG 7 WC Engineering, Environmental; Environmental Sciences SC Engineering; Environmental Sciences & Ecology GA 438KQ UT WOS:000169052800032 PM 11414022 ER PT J AU Nzengung, VA Castillo, RM Gates, WP Mills, GL AF Nzengung, VA Castillo, RM Gates, WP Mills, GL TI Abiotic transformation of perchloroethylene in homogeneous dithionite solution and in suspensions of dithionite-treated clay minerals SO ENVIRONMENTAL SCIENCE & TECHNOLOGY LA English DT Article ID IRON OXIDATION-STATE; CARBON-TETRACHLORIDE; REDUCTIVE DECHLORINATION; DIOCTAHEDRAL SMECTITES; FERRUGINOUS SMECTITE; STRUCTURAL IRON; OCTAHEDRAL-IRON; NONTRONITE; MECHANISM; KINETICS AB The reductive dechlorination of perchloroethylene (PCE) in homogeneous solutions of dithionite and at the surfaces of, dithionite-citrate-bicarbonate (DCB) treated ferruginous smectite and Na-montmorillonite was studied. Transformation products of PCE identified in dosed dithionite-treated samples included TCE, DCE, 1,1;2-trichloroethane (TCA), 1,1 dichloroethane (DCP;), chloroacetylene,acetylene, ethene, and ethane. The decomposition of dithionite to sulfate yielded both protons and electrons necessary far hydrodechlorination (hydrogenolysis) of PCE. Dithionite treatment of the Fe-poor Na-montmorillonite enhanced reductive dechlorination of PCE relative to dithionite-treated Fe-rich ferruginous smectite, within the range of 11.5-137.8 mM dithionite. For the same dithionite concentration, the kinetics of the heterogeneous reactions of PCE was generally faster than that of the homogeneous reaction, and higher concentrations of TCE were measured in the heterogeneous reactions. interestingly, increases in the mass of the clay minerals used, the Fe(2+) content in the clay mineral structure, or the dithionite concentration used did not necessarily enhance the abiotic transformation of PCE, as would otherwise be predicted. The most efficient reductive dechlorination of PCE was observed with 0.5% clay (m/v) treated with 34.5 mM dithionite buffered at pH 8.5. The solid-state transfer of electrons to surfaces and edges, rather than the redox capacity, limited the dechlorination of PCE by reduced: ferruginous smectite and/or suspensions containing a higher clay mass. The greater reactivity of ditirionite-reduced montmorillonite than similarly treated ferruginous smectite is attributed to (il the well-documented layer collapse and aggregation of chemically reduced clays that increases with the clay's iron content, (ii) the location of solid-phase Fe(2+) in the reduced clay mineral and whether it is accessible or inaccessible for reaction with PCE at the mineral edges and surfaces where the reactions are thought to occur, and (iii) the greater swellability of montmorillonite versus ferruginous smectite. The faster dechlorination rate of PCE observed with dithionite-reduced Fe-poor montmorillonite than similarly reduced iron-rich ferruginous smectite suggests that the use of dithionite barriers for in-situ treatment of chlorinated solvent plumes should not be limited to aquifers with Fe-rich sediments. C1 Univ Georgia, Dept Geol, Athens, GA 30602 USA. Univ Georgia, Savannah River Ecol Lab, Aiken, SC 29802 USA. RP Nzengung, VA (reprint author), Univ Georgia, Dept Geol, Athens, GA 30602 USA. EM vnzengun@uga.edu NR 51 TC 26 Z9 29 U1 1 U2 16 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0013-936X J9 ENVIRON SCI TECHNOL JI Environ. Sci. Technol. PD JUN 1 PY 2001 VL 35 IS 11 BP 2244 EP 2251 DI 10.1021/es001578b PG 8 WC Engineering, Environmental; Environmental Sciences SC Engineering; Environmental Sciences & Ecology GA 438KQ UT WOS:000169052800035 PM 11414025 ER PT J AU Humphries, SS Gwinn, KD Stewart, AJ AF Humphries, SS Gwinn, KD Stewart, AJ TI Effects of endophyte status of tall fescue tissues on the earthworm (Eisenia fetida) SO ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY LA English DT Article DE tall fescue; Neotyphodium sp.; fungal endophyte; earthworms; soil invertebrate ID ACREMONIUM ENDOPHYTE; INFECTED TURFGRASSES; ENHANCED RESISTANCE; FESTUCA-ARUNDINACEA; CONTAMINATED SOIL; GRASSES; STRESS AB A cryptic fungal endophyte, Neotyphodium coenophialum, infects most tall fescue (Festuca arundinacea) pastures in the United States. Cattle, sheep, and horses that consume the endophyte-infected grass can suffer fescue toxicosis caused by toxic alkaloids in the infected plants. The effects of the endophyte on mammalian herbivores have been well documented. but less is known regarding the quality of the grass (infected vs noninfected) as a food material for soil invertebrates. We conducted 21-d tests with earthworms (Eisenia fetida) to determine the nutritional quality of endophyte-infected and noninfected tall fescue leaf and root tissues. Earthworm survival, growth, and reproduction were measured in each treatment combination of tissue type and infection status. Earthworm survival was 100% in all treatments. Tall fescue tissue type (leaf vs root) and infection status (present or absent) both significantly affected E. fetida growth and reproduction. The earthworms grew and had moderate levels of reproduction in replicates containing tall fescue leaf tissue as the sole food source regardless of the endophyte-infection status, but earthworms lost weight and had less reproduction in replicates where tall fescue root tissue was the sole food source. An unexpected effect of infection status on earthworm growth in the tall fescue leaf-tissue treatments was also evident: mean growth of E. fetida with access to endophyte-infected leaf tissue as the sole food source was 3.6-fold greater than mean growth of E. fetida with access to noninfected leaf tissue as the sole food source, Knowledge regarding the relative effects of endophyte status of tall fescue on soil organisms may allow the development of more effective environmental management strategies at sites where tall fescue is being considered for use in phytoremediation or for vegetative cover. Investigators working with tall fescue should be alert to the possibility of endophyte-mediated effects of tall fescue on other organisms and, at a minimum, should provide information regarding the grass's infection status when reporting the results of studies that involve use of tall fescue. C1 Oak Ridge Natl Lab, Div Environm Sci, Oak Ridge, TN 37831 USA. Univ S Carolina, Columbia, SC 29202 USA. Univ Tennessee, Dept Entomol & Plant Pathol, Knoxville, TN 37901 USA. RP Stewart, AJ (reprint author), Oak Ridge Natl Lab, Div Environm Sci, POB 2008, Oak Ridge, TN 37831 USA. OI stewart, arthur/0000-0003-1968-5997 NR 25 TC 10 Z9 12 U1 2 U2 9 PU SETAC PI PENSACOLA PA 1010 NORTH 12TH AVE, PENSACOLA, FL 32501-3367 USA SN 0730-7268 J9 ENVIRON TOXICOL CHEM JI Environ. Toxicol. Chem. PD JUN PY 2001 VL 20 IS 6 BP 1346 EP 1350 DI 10.1897/1551-5028(2001)020<1346:EOESOT>2.0.CO;2 PG 5 WC Environmental Sciences; Toxicology SC Environmental Sciences & Ecology; Toxicology GA 457YL UT WOS:000170166000025 PM 11392146 ER PT J AU Kemper, G Dewald, A Wiedenhover, I Peusquens, R Kasemann, S Zell, KO von Brentano, P Hubel, H Chmel, S Gorgen, A Bazzacco, D Venturelli, R Lunardi, S Napoli, DR Hannachi, F Lopez-Martens, A Krucken, R Cooper, JR Clark, RM Deleplanque, MA Lee, IY Machiavelli, AO Stephens, FS AF Kemper, G Dewald, A Wiedenhover, I Peusquens, R Kasemann, S Zell, KO von Brentano, P Hubel, H Chmel, S Gorgen, A Bazzacco, D Venturelli, R Lunardi, S Napoli, DR Hannachi, F Lopez-Martens, A Krucken, R Cooper, JR Clark, RM Deleplanque, MA Lee, IY Machiavelli, AO Stephens, FS TI Investigation of the magnetic rotation in Pb-196 SO EUROPEAN PHYSICAL JOURNAL A LA English DT Article ID DECAY CURVE METHOD; SHEARS MECHANISM; BANDS; LIFETIMES AB Lifetimes for low-lying members of the irregular DeltaI = 1 band in Pb-196 have been measured by means of the EUROBALL spectrometer using the coincidence recoil distance technique. The Dy-164(S-36,4n)Pb-196 reaction at a beam energy of 168 MeV was used. The data were analyzed with the differential decay-curve method DDCM). A characteristic drop in the reduced transition probabilities with increasing angular momentum was observed in agreement with predictions by the semiclassical model for the shears mechanism. C1 Univ Cologne, Inst Kernphys, D-50937 Cologne, Germany. Univ Bonn, Inst Strahlen & Kernphys, D-5300 Bonn, Germany. Univ Padua, Dipartimento Fis, Padua, Italy. Ist Nazl Fis Nucl, Sez Padova, Padua, Italy. Ist Nazl Fis Nucl, Lab Nazl Legnaro, I-35020 Legnaro, Italy. Inst Phys Nucl, F-91405 Orsay, France. Yale Univ, AW Wright Nucl Struct Lab, New Haven, CT 06520 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Kemper, G (reprint author), Univ Cologne, Inst Kernphys, Zulpicher Str 77, D-50937 Cologne, Germany. RI Dewald, Alfred/O-5810-2015; Kruecken, Reiner/A-1640-2013; Napoli, Daniel R./D-9863-2012; OI Kruecken, Reiner/0000-0002-2755-8042; Napoli, Daniel R./0000-0002-8154-6958; Gorgen, Andreas/0000-0003-1916-9941 NR 18 TC 9 Z9 9 U1 0 U2 0 PU SPRINGER-VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 USA SN 1434-6001 J9 EUR PHYS J A JI Eur. Phys. J. A PD JUN PY 2001 VL 11 IS 2 BP 121 EP 124 DI 10.1007/s100500170076 PG 4 WC Physics, Nuclear; Physics, Particles & Fields SC Physics GA 465RY UT WOS:000170604800001 ER PT J AU Semadeni, F Amato, A Roessli, B Boni, P Baines, C Masuda, T Uchinokura, K Shirane, G AF Semadeni, F Amato, A Roessli, B Boni, P Baines, C Masuda, T Uchinokura, K Shirane, G TI Macroscopic and local magnetic moments in Si-doped CuGeO3 as determined by neutron and mu SR studies SO EUROPEAN PHYSICAL JOURNAL B LA English DT Article ID UNIFORM-ANTIFERROMAGNETIC PHASES; SPIN-PEIERLS SYSTEMS; SINGLE-CRYSTALS; SCATTERING; TRANSITION; ORDER; DIAGRAM; SUSCEPTIBILITY; CUGE1-XSIXO3; CU1-XZNXGEO3 AB The temperature-concentration phase diagram of the Si-doped spin-Peierls compound CuGeO3 is investigated by means of neutron scattering and muon spin rotation spectroscopy in order to determine the microscopic distribution of the magnetic and lattice dimerised regions as a function of doping. The analysis of the zero-field muon spectra has confirmed the spatial inhomogeneity of the staggered magnetisation that characterises the antiferromagnetic superlattice peaks observed with neutrons. In addition, the variation of the macroscopic order parameter with doping can be understood by considering the evolution of the local magnetic moment as well as of the various regions contributing to the muon signal. C1 ETH Zurich, Neutron Scattering Lab, CH-5232 Villigen, Switzerland. PSI, Lab Muon Spin Spect, CH-5232 Villigen, Switzerland. Tech Univ Munich, Phys Dept E21, D-85747 Garching, Germany. Univ Tokyo, Dept Adv Mat Sci, Bunkyo Ku, Tokyo 1138656, Japan. Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. RP Semadeni, F (reprint author), ETH Zurich, Neutron Scattering Lab, CH-5232 Villigen, Switzerland. RI Amato, Alex/H-7674-2013 OI Amato, Alex/0000-0001-9963-7498 NR 18 TC 0 Z9 0 U1 0 U2 0 PU SPRINGER-VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 USA SN 1434-6028 J9 EUR PHYS J B JI Eur. Phys. J. B PD JUN PY 2001 VL 21 IS 3 BP 307 EP 311 DI 10.1007/s100510170172 PG 5 WC Physics, Condensed Matter SC Physics GA 450LE UT WOS:000169743700001 ER PT J AU Abele, A Adomeit, J Amsler, C Baker, CA Barnett, BM Batty, CJ Benayoun, M Bischoff, S Blum, P Braune, K Case, T Crede, V Crowe, KM Degener, T Doser, M Dunnweber, W Engelhardt, D Faessler, MA Giarritta, P Haddock, RP Heinsius, FH Heinzelmann, M Herbstrith, A Hessey, NP Hidas, P Holtzhaussen, C Jamnik, D Kalinowsky, H Kammel, P Kisiel, J Klempt, E Koch, H Kunze, M Kurilla, U Lakata, M Landua, R Matthay, H Meyer, CA Meyer-Wildhagen, F Montanet, L Ouared, R Peters, K Pick, B Ratajczak, M Regenfus, C Roethel, W Spanier, S Stock, H Strohbusch, U Suffert, M Suh, JS Thoma, U Tischhauser, M Uman, I Wallis-Plachner, S Walther, D Wiedner, U Wittmack, K AF Abele, A Adomeit, J Amsler, C Baker, CA Barnett, BM Batty, CJ Benayoun, M Bischoff, S Blum, P Braune, K Case, T Crede, V Crowe, KM Degener, T Doser, M Dunnweber, W Engelhardt, D Faessler, MA Giarritta, P Haddock, RP Heinsius, FH Heinzelmann, M Herbstrith, A Hessey, NP Hidas, P Holtzhaussen, C Jamnik, D Kalinowsky, H Kammel, P Kisiel, J Klempt, E Koch, H Kunze, M Kurilla, U Lakata, M Landua, R Matthay, H Meyer, CA Meyer-Wildhagen, F Montanet, L Ouared, R Peters, K Pick, B Ratajczak, M Regenfus, C Roethel, W Spanier, S Stock, H Strohbusch, U Suffert, M Suh, JS Thoma, U Tischhauser, M Uman, I Wallis-Plachner, S Walther, D Wiedner, U Wittmack, K CA CRYSTAL BARREL Collaboration TI 4 pi-decays of scalar and vector mesons SO EUROPEAN PHYSICAL JOURNAL C LA English DT Article ID 18 GEV/C; REST; ANNIHILATION; GLUEBALL; STATES; DECAY; WAVE AB Two different pn annihilation modes, (p) over barn --> pi (-)4 pi (0) and (p) over barn --> 2 pi (-)2 pi (0)pi (+), are used to study the 4 pi -decays of scalar and vector mesons. The data are dominated by 4 pi scalar isoscalar interactions. At least two states are needed, the f(0)(1370) and the f(0)(1500). The 4 pi -decay width of the f(0)(1370) is more than 6 times larger than the sum of all observed partial decay widths to two pseudoscalar mesons. The state has important couplings to (pi pi )s(pi pi )s and to pp. The 4 pi -decays of the f(0)(1500) represent about half of its total width. The p(1450) and the p(1700) are observed in several 4 pi decay modes. The ratio of the 4 pi relative to the 2 pi decay of the p(1450) is in contradiction to its proposed interpretation as a pure hybrid state but it suggests that it is not a pure 2(3)S(1)-state either. Our results favour the assignment of the p(1700) as D-3(1) state, its interpretation as 3(3)S(1)-state is less plausible. C1 Univ Karlsruhe, D-76021 Karlsruhe, Germany. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. Ruhr Univ Bochum, D-44780 Bochum, Germany. Univ Bonn, D-53115 Bonn, Germany. Hungarian Acad Sci, H-1525 Budapest, Hungary. Rutherford Appleton Lab, Didcot OX11 0QX, Oxon, England. CERN, CH-1211 Geneva 4, Switzerland. Univ Hamburg, D-22761 Hamburg, Germany. Univ Calif Los Angeles, Los Angeles, CA 90024 USA. Univ Munich, D-80333 Munich, Germany. LPNHE Paris 6, F-75252 Paris, France. Carnegie Mellon Univ, Pittsburgh, PA 15213 USA. Ctr Rech Nucl, F-67037 Strasbourg, France. Univ Zurich, CH-8057 Zurich, Switzerland. RP Univ Karlsruhe, D-76021 Karlsruhe, Germany. RI Peters, Klaus/C-2728-2008; Meyer, Curtis/L-3488-2014; OI Peters, Klaus/0000-0001-7133-0662; Meyer, Curtis/0000-0001-7599-3973; Heinsius, Fritz-Herbert/0000-0002-9545-5117 NR 30 TC 31 Z9 31 U1 0 U2 2 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 JUN PY 2001 VL 21 IS 2 BP 261 EP 269 DI 10.1007/s100520100735 PG 9 WC Physics, Particles & Fields SC Physics GA 475EF UT WOS:000171148700005 ER PT J AU Grimsditch, M Berger, A Johnson, J Metlushko, V Ilic, B Neuzil, P Kumar, R AF Grimsditch, M Berger, A Johnson, J Metlushko, V Ilic, B Neuzil, P Kumar, R TI Magnetic stability of nano-particles: The role of dipolar instability pockets SO EUROPHYSICS LETTERS LA English DT Article ID SWITCHING FIELD; FERROMAGNETIC PARTICLES; THIN-FILMS; CO DOTS; REVERSAL; ARRAYS; LITHOGRAPHY; ELEMENTS; NUCLEATION; ANISOTROPY AB We show that the magnetic stability of nano-particles, with regard to magnetization reversal or domain formation, is controlled by dipolar instability pockets. These pockets are regions in which the local dipolar fields (i.e. shape-dependent effects) favor a spin reorientation. Calculated shape-dependent demagnetizing fields coupled with exchange contributions combine to yield the field at which a magnon mode attains zero frequency implying the onset of reversal or domain formation. Calculated switching-onset fields are found to explain experimental data as a function of: material, thickness, aspect ratio, and shape. C1 Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. Univ Illinois, Dept Elect Engn & Comp Sci, Chicago, IL 60607 USA. Cornell Univ, Sch Appl & Engn Phys, Ithaca, NY 14853 USA. Inst Microelect, Singapore 117685, Singapore. RP Grimsditch, M (reprint author), Argonne Natl Lab, Div Mat Sci, 9700 S Cass Ave, Argonne, IL 60439 USA. RI Neuzil, Pavel/B-9981-2012; Ilic, Rob/N-1359-2014; Berger, Andreas/D-3706-2015 OI Berger, Andreas/0000-0001-5865-6609 NR 45 TC 8 Z9 8 U1 0 U2 4 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 JUN PY 2001 VL 54 IS 6 BP 813 EP 819 DI 10.1209/epl/i2001-00326-y PG 7 WC Physics, Multidisciplinary SC Physics GA 450TT UT WOS:000169759700018 ER PT J AU Lim, JH Choi, J Han, SJ Kim, SH Hwang, HZ Jin, DK Ahn, BY Han, YS AF Lim, JH Choi, J Han, SJ Kim, SH Hwang, HZ Jin, DK Ahn, BY Han, YS TI Molecular cloning and characterization of thermostable DNA ligase from Aquifex pyrophilus, a hyperthermophilic bacterium SO EXTREMOPHILES LA English DT Article DE DNA ligase; Aquifex pyrophilus; hyperthermophile; thermostability; repeat expansion detection ID NUCLEOTIDE-SEQUENCE; ENCODING GENE; BACTERIOPHAGE-T7 DNA; EXPRESSION; PURIFICATION; PROTEIN; OVEREXPRESSION; DISEASE; REPEATS; GENOME AB A DNA ligase gene from the hyperthermophilic bacterium Aquifex pyrophilus (Ap) was cloned and sequenced. An open reading frame of 2,157 bp that codes for a 82-kDa protein showed 40%-60% homology with a series of NAD(+)-dependent DNA ligases from different organisms. The recombinant enzyme Ap DNA ligase expressed in Escherichia coli was purified to homogeneity and characterized. The activity of Ap DNA ligase gradually increased in proportion to the concentration of monovalent salt up to 200 mM NaCl, 150 mM KCl, 200 mM NH4Cl, and 350 mM potassium glutamate. The optimum temperature and pH of Ap DNA ligase were greater than 65 degreesC and 8.0-8.6, respectively, for nick-closing activity. More than 75% of the ligation activity was retained after incubation at 95 degreesC for 60 min, whereas the half-lives of Thermus aquaticus and Escherichia coli DNA ligases at 95 degreesC were less than or equal to 15 min and 5 min, respectively. Thermostable Ap DNA ligase was applied to repeat expansion detection (RED) and could be a useful enzyme in DNA diagnostics. C1 Korea Inst Sci & Technol, Struct Biol Res Ctr, Seoul 130650, South Korea. Korea Univ, Grad Sch Biotechnol, Seoul 136701, South Korea. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. Ewha Womans Univ, Dept Biol, Seoul, South Korea. Sungkyunkwan Univ, Samsung Med Ctr, Dept Pediat, Seoul, South Korea. RP Han, SJ (reprint author), Korea Inst Sci & Technol, Struct Biol Res Ctr, 39-1 Hawallkok Dong, Seoul 130650, South Korea. NR 35 TC 5 Z9 6 U1 1 U2 3 PU SPRINGER-VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 USA SN 1431-0651 J9 EXTREMOPHILES JI Extremophiles PD JUN PY 2001 VL 5 IS 3 BP 161 EP 168 DI 10.1007/s007920100187 PG 8 WC Biochemistry & Molecular Biology; Microbiology SC Biochemistry & Molecular Biology; Microbiology GA 448XY UT WOS:000169656300003 PM 11453459 ER PT J AU Segev, B Wells, JC AF Segev, B Wells, JC TI A light-fronts approach to a two-center time-dependent Dirac equation SO FOUNDATIONS OF PHYSICS LA English DT Article; Proceedings Paper CT International-Association-for-Relativistic-Dynamics CY JUN, 2000 CL RAMAT GAN, ISRAEL SP Internat Assoc Relativist Dynam ID HEAVY-ION COLLISIONS; POSITRON PAIR PRODUCTION; HIGH-ENERGY LIMIT; COULOMB COLLISIONS; ELECTROMAGNETIC-FIELDS; FIXED TARGETS; SULFUR IONS; COLLIDERS AB The two center time dependent Dirac equation, for an electron in the external field of two colliding ultrarelativistic heavy ions is considered, In the ultrarelativistic limit, the ions are practically moving at the speed of light and the electromagnetic fields of the ions arc confined to thc light fronts by the extreme Lorentz contraction and by the choice of gauge, designed to remove the long-range Coulomb effects. An exact solution to the ultrarelativistic limit of the two-center Dirac equation is found by using light-front variables and a light-fronts representation. Previously unexplained experimental results obtained at CERN's SPS are explained in this way and predictions are made as to where one should look, in momentum space, and in space-time, if one wants to study and observe non-perturbative electromagnetic pair-production effects in extremely relativistic heavy-ion collisions. C1 Ben Gurion Univ Negev, Dept Chem, IL-84105 Beer Sheva, Israel. Oak Ridge Natl Lab, Ctr Computat Sci, Oak Ridge, TN 37831 USA. RP Segev, B (reprint author), Ben Gurion Univ Negev, Dept Chem, POB 653, IL-84105 Beer Sheva, Israel. RI Wells, Jack/D-3675-2016 OI Wells, Jack/0000-0002-5083-3030 NR 24 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 0015-9018 J9 FOUND PHYS JI Found. Phys. PD JUN PY 2001 VL 31 IS 6 BP 993 EP 1015 DI 10.1023/A:1017568103155 PG 23 WC Physics, Multidisciplinary SC Physics GA 476GB UT WOS:000171216900008 ER PT J AU Caves, CM Fuchs, CA Rungta, P AF Caves, CM Fuchs, CA Rungta, P TI Entanglement of formation of an arbitrary state of two rebits SO FOUNDATIONS OF PHYSICS LETTERS LA English DT Article DE quantum entanglement; quantum information; real quantum mechanics ID MIXED STATES; QUANTUM; SEPARABILITY AB We consider entanglement for quantum states defined in vector spaces over the real numbers. Such real entanglement is different from entanglement in standard quantum mechanics over the complex numbers. The differences provide insight into the nature of entanglement in standard quantum theory. Wootters [Phys. Rev. Lett. 80, 2245 (1998)] has given an explicit formula for the entanglement of formation of two qubits in terms of what he calls the concurrence of the joint density operator. We give a contrasting formula for the entanglement of formation of an arbitrary state of two "rebits," a rebit being a system whose Hilbert space is a 2-dimensional real vector space. C1 Univ New Mexico, Ctr Adv Studies, Dept Phys & Astron, Albuquerque, NM 87131 USA. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Bell Labs, Lucent Technol, Murray Hill, NJ 07974 USA. RP Caves, CM (reprint author), Univ New Mexico, Ctr Adv Studies, Dept Phys & Astron, Albuquerque, NM 87131 USA. RI Caves, Carlton/K-8167-2014 OI Caves, Carlton/0000-0001-8876-1186 NR 22 TC 34 Z9 35 U1 0 U2 3 PU KLUWER ACADEMIC/PLENUM PUBL PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 0894-9875 J9 FOUND PHYS LETT JI Found. Phys. Lett. PD JUN PY 2001 VL 14 IS 3 BP 199 EP 212 DI 10.1023/A:1012215309321 PG 14 WC Physics, Multidisciplinary SC Physics GA 444KW UT WOS:000169399500001 ER PT J AU Vogt, C Klunder, GL AF Vogt, C Klunder, GL TI Separation of metal ions by capillary electrophoresis - diversity, advantages, and drawbacks of detection methods SO FRESENIUS JOURNAL OF ANALYTICAL CHEMISTRY LA English DT Review ID INDUCTIVELY-COUPLED PLASMA; ALKALINE-EARTH METAL; INDIRECT UV DETECTION; MASS SPECTROMETRIC DETECTION; COLUMN ELECTROCHEMICAL DETECTION; INDIRECT FLUOROMETRIC DETECTION; LASER-INDUCED FLUORESCENCE; ELEMENT-SPECIFIC DETECTION; REFRACTIVE-INDEX DETECTOR; CE-ICP-MS AB Capillary electrophoresis (CE) has been applied to metal-ion analysis during the last 10 years. To improve sensitivity and selectivity different modes of detection have been adapted or developed. The selection of commercially available detection systems for metal-ion analysis is still primarily limited to UV-Vis detection, although other commercial systems, e.g. fluorescence, conductivity, or interfaces for coupling to mass spectrometry (MS) or inductively coupled plasma mass spectrometry (ICP-MS) are becoming available. High demands are made on any detector used in CE, because the analytical signal has to be extracted from less than 1 nL of sample, which corresponds to a total amount of less than or equal to 10(-12) to 10(-15) mol analyte. This paper compares currently available and recently developed detection methods for CE as applied to the analysis of metal ions. Commercially available techniques, for example UV-Vis, fluorescence, or mass spectrometry, and other new detection methods including electrochemistry, radioactivity, and XRF, are discussed and future trends are anticipated. C1 IFW Dresden, D-01171 Dresden, Germany. Univ Calif Lawrence Livermore Natl Lab, Forens Sci Ctr, Livermore, CA 94551 USA. RP Vogt, C (reprint author), IFW Dresden, POB 27 01 16, D-01171 Dresden, Germany. NR 168 TC 32 Z9 34 U1 1 U2 19 PU SPRINGER-VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 USA SN 0937-0633 J9 FRESEN J ANAL CHEM JI Fresenius J. Anal. Chem. PD JUN PY 2001 VL 370 IS 4 BP 316 EP 331 DI 10.1007/s002160100830 PG 16 WC Chemistry, Analytical SC Chemistry GA 457AN UT WOS:000170115100002 PM 11495051 ER PT J AU Hu, WZ Hasebe, K Tanaka, K Fritz, JS Inoue, S Ozeki, M AF Hu, WZ Hasebe, K Tanaka, K Fritz, JS Inoue, S Ozeki, M TI Determination of inorganic acids by ion chromatography with n-tetradecylphosphocholine (zwitterionic surfactant) as the stationary phase and pure water as the mobile phase SO FRESENIUS JOURNAL OF ANALYTICAL CHEMISTRY LA English DT Article ID CATION-EXCHANGE CHROMATOGRAPHY; PRECIPITATION SAMPLES AB A new ion chromatographic (IV) system, in which n-tetradecylphosphocholine (TDPC, a phosphobetaine type of zwitterionic surfactant) was used as the stationary phase, pure water as the mobile phase, and conductivity as the method of detection, has been developed for the determination of inorganic acids. Five model acids' HCl, HNO3, HClO4, H2SO4, and H3PO4, were separated to baseline and eluted in the order H3PO4 > HCl > HNO3 > H2SO4 > HClO4. When peak areas were plotted against the concentrations of the acids in samples, linear calibration curves were obtained. Ultimate determination limits were approximately 1 mmol L-1, but the discrimination of the method between solutions of different concentration was better than 10 mu mol L-1 for those model analytes. Salts of divalent cations could also be separated, but they were eluted faster than the acids. No separation was observed for the salts of monovalent cations. This newly proposed approach is applicable to the simultaneous determination of the inorganic acids (produced by reactions of NOx, SOx, and HCl with water) in aerosols. C1 Hokkaido Univ, Grad Sch Sci, Div Chem, Sapporo, Hokkaido 0600810, Japan. Hokkaido Univ, Grad Sch Environm Earth Sci, Div Mat Sci, Sapporo, Hokkaido 0600810, Japan. Natl Ind Res Inst Nagoya, Nagoya, Aichi 4628510, Japan. Iowa State Univ, US DOE, Ames Lab, Ames, IA USA. Iowa State Univ, Dept Chem, Ames, IA USA. INOAC Corp, Nakamura Ku, Nagoya, Aichi, Japan. RP Hu, WZ (reprint author), Hokkaido Univ, Grad Sch Sci, Div Chem, Sapporo, Hokkaido 0600810, Japan. NR 12 TC 0 Z9 0 U1 0 U2 1 PU SPRINGER-VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 USA SN 0937-0633 J9 FRESEN J ANAL CHEM JI Fresenius J. Anal. Chem. PD JUN PY 2001 VL 370 IS 4 BP 399 EP 402 DI 10.1007/s002160100839 PG 4 WC Chemistry, Analytical SC Chemistry GA 457AN UT WOS:000170115100014 PM 11495063 ER PT J AU Mori, M Hu, WZ Fritz, JS Tsue, H Kaneta, T Tanaka, S AF Mori, M Hu, WZ Fritz, JS Tsue, H Kaneta, T Tanaka, S TI Determination of inorganic anions in human saliva by zwitterionic micellar capillary electrophoresis SO FRESENIUS JOURNAL OF ANALYTICAL CHEMISTRY LA English DT Article ID ELECTROSTATIC ION CHROMATOGRAPHY; MOBILE-PHASE; CATIONIC POLYMERS; SEPARATION; WATER; SURFACTANTS; BEHAVIOR AB Capillary electrophoresis (CE) using sulfobetaine-type zwitterionic micelles as the background electrolyte (BGE) has been used to determine inorganic anions in human saliva. The zwitterionic micelles resulted in unique migration behavior for the separation of inorganic anions. They also prevented adsorption of proteins on the inner wall of the capillary. These properties of the zwitterionic micelles enabled the direct determination of inorganic anions in human saliva. Three species of inorganic anions, NO2-, NO3-, and SCN-, were found in real samples and the analysis was achieved within 3 min. Direct UV-absorption was used as the detection method and the detection limits for these anions were 2.0, 1.0, and 5.0 mu mol L-1, respectively (0.09, 0.06, and 0.30 mug mL(-1)). C1 Hokkaido Univ, Grad Sch Environm Earth Sci, Div Mat Sci 1, Sapporo, Hokkaido 0600810, Japan. Hokkaido Univ, Fac Sci, Dept Chem 1, Sapporo, Hokkaido 0600810, Japan. Iowa State Univ, Dept Chem 1, Ames, IA 50011 USA. Iowa State Univ, Ames Lab, Ames, IA 50011 USA. Kyushu Univ, Grad Sch Engn, Dept Appl Chem 1, Fukuoka 8128581, Japan. RP Tanaka, S (reprint author), Hokkaido Univ, Grad Sch Environm Earth Sci, Div Mat Sci 1, Sapporo, Hokkaido 0600810, Japan. RI Kaneta, Takashi/D-3593-2011 NR 23 TC 21 Z9 21 U1 0 U2 3 PU SPRINGER-VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 USA SN 0937-0633 J9 FRESEN J ANAL CHEM JI Fresenius J. Anal. Chem. PD JUN PY 2001 VL 370 IS 4 BP 429 EP 433 DI 10.1007/s002160100804 PG 5 WC Chemistry, Analytical SC Chemistry GA 457AN UT WOS:000170115100020 PM 11495069 ER PT J AU Stiegel, GJ Maxwell, RC AF Stiegel, GJ Maxwell, RC TI Gasification technologies: the path to clean, affordable energy in the 21st century SO FUEL PROCESSING TECHNOLOGY LA English DT Article DE gasification; energy plants; feedstock AB The gasification of carbon-based solid and liquid materials has been around for nearly two hundred years and was used extensively for the production of town gas in the latter part of the: nineteenth and twentieth centuries. Although this application has all but vanished, other applications have evolved, thus continuing gasification's important role as a commercial technology. Numerous advancements have been made since its introduction, leading to a more cost-competitive, thermally efficient, and environmentally friendly technology. However, as deregulation of the power industry continues and as increased environmental pressures are placed on industry, opportunities for further technological advances and expanded applications to meet these challenges will be created. In addition, these changes will likely restructure the technology and ownership objectives, placing premiums on efficiency, environmental acceptability, and the ability to utilize multiple feedstocks and produce multiple products. In the twentieth century, gasification will be the heart of a new generation of energy plants, possessing both feedstock and product flexibility, near-zero emission of pollutants, high thermal efficiency and capture of carbon dioxide, and low feedstock and operating and maintenance (O&M) costs. Published by Elsevier Science B.V. C1 US DOE, Natl Energy Technol Lab, Pittsburgh, PA 15236 USA. Parson Infrastruct & Technol Grp, Pittsburgh, PA 15236 USA. RP Stiegel, GJ (reprint author), US DOE, Natl Energy Technol Lab, POB 10940, Pittsburgh, PA 15236 USA. NR 8 TC 82 Z9 88 U1 1 U2 16 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0378-3820 J9 FUEL PROCESS TECHNOL JI Fuel Process. Technol. PD JUN PY 2001 VL 71 IS 1-3 SI SI BP 79 EP 97 DI 10.1016/S0378-3820(01)00138-2 PG 19 WC Chemistry, Applied; Energy & Fuels; Engineering, Chemical SC Chemistry; Energy & Fuels; Engineering GA 435PF UT WOS:000168889300006 ER PT J AU Chum, HL Overend, RP AF Chum, HL Overend, RP TI Biomass and renewable fuels SO FUEL PROCESSING TECHNOLOGY LA English DT Article DE biomass; fuels from biomass; biological hydrogen production; sustainable energy systems; carbon constrained world AB Biomass is an important contributor to the world economy. Agriculture and forest products industries provide food, feed, fiber, and a wide range of necessary products like shelter, packaging, clothing, and communications. However, biomass is also a source of a large variety of chemicals and materials, and of electricity and fuels. About 60% of the needed process energy in pulp: paper, and forest products is provided by biomass combustion. These processes could be improved to the point of energy self-sufficiency of these industries. Today's corn refinery industry produces a wide range of products including starch-based ethanol fuels for transportation. The biomass industry can produce additional ethanol by fermenting some by-product sugar streams. Lignocellulosic biomass is a potential source for ethanol that is not directly linked to food production. Also, through gasification biomass can lead to methanol, mixed alcohols, and Fischer-Tropsch liquids. The life science revolution we are witnessing has the potential to radically change the green plants and products we obtain from them. Green plants developed to produce desired products and energy could be possible in the future. Biological systems can already be tailored to produce fuels such as hydrogen. Policy drivers for increased use of biomass for energy and biobased products are reviewed for their potential contributions for a carbon constrained world. (C) 2001 Published by Elsevier Science B.V. C1 Natl Renewable Energy Lab, Golden, CO 80401 USA. RP Chum, HL (reprint author), Natl Renewable Energy Lab, 1617 Cole Blvd, Golden, CO 80401 USA. OI Overend, Ralph/0000-0002-5442-0890 NR 13 TC 198 Z9 213 U1 5 U2 69 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0378-3820 J9 FUEL PROCESS TECHNOL JI Fuel Process. Technol. PD JUN PY 2001 VL 71 IS 1-3 SI SI BP 187 EP 195 DI 10.1016/S0378-3820(01)00146-1 PG 9 WC Chemistry, Applied; Energy & Fuels; Engineering, Chemical SC Chemistry; Energy & Fuels; Engineering GA 435PF UT WOS:000168889300015 ER PT J AU Sackett, JI AF Sackett, JI TI The future of nuclear energy SO FUEL PROCESSING TECHNOLOGY LA English DT Article DE nuclear; technology; energy AB Nothing will be as important to the people of the world in the next century and beyond as energy to provide clean water and electricity. But how will this need be met with the increasingly recognized need to substantially reduce carbon dioxide emissions? Nuclear power provides a compelling option, but it must meet certain requirements in order to gain public and political support. In this paper, those requirements are examined and the imperative for continued research into advanced nuclear power technologies is discussed. Published by Elsevier Science B.V. C1 Argonne Natl Lab, Idaho Falls, ID 83403 USA. RP Sackett, JI (reprint author), Argonne Natl Lab, POB 2528, Idaho Falls, ID 83403 USA. NR 8 TC 1 Z9 1 U1 2 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0378-3820 J9 FUEL PROCESS TECHNOL JI Fuel Process. Technol. PD JUN PY 2001 VL 71 IS 1-3 SI SI BP 197 EP 204 DI 10.1016/S0378-3820(01)00147-3 PG 8 WC Chemistry, Applied; Energy & Fuels; Engineering, Chemical SC Chemistry; Energy & Fuels; Engineering GA 435PF UT WOS:000168889300016 ER PT J AU Collins, C Volik, S Kowbel, D Ginzinger, D Ylstra, B Cloutier, T Hawkins, T Predki, P Martin, C Wernick, M Kuo, WL Alberts, A Gray, JW AF Collins, C Volik, S Kowbel, D Ginzinger, D Ylstra, B Cloutier, T Hawkins, T Predki, P Martin, C Wernick, M Kuo, WL Alberts, A Gray, JW TI Comprehensive genome sequence analysis of a breast cancer amplicon SO GENOME RESEARCH LA English DT Article ID DNA COPY NUMBER; 20Q13.2 AMPLIFICATION; HUMAN NEOPLASMS; PHYSICAL MAP; 20Q GAIN; IN-SITU; HYBRIDIZATION; REGION; GENES; IMMORTALIZATION AB Gene amplification occurs in most solid tumors and is associated with poor prognosis. Amplification of 20q13.2 is common to several tumor types including breast cancer. The 1 Mb of sequence spanning the 20q13.2 breast cancer amplicon is one of the most exhaustively studied segments of the human genome. These studies have included amplicon mapping by comparative genomic hybridization (CGH], fluorescent in-situ hybridization (FISH), array-CGH, quantitative microsatellite analysis (QUMA), and functional genomic studies. Together these studies revealed a complex amplicon structure suggesting the presence of at least two driver genes in some tumors. One of these, ZNF217, is capable of immortalizing human mammary epithelial cells [HMEC) when overexpressed. In addition, we now report the sequencing of this region in human and mouse, and on quantitative expression studies in tumors. Amplicon localization now is straightforward and the availability of human and mouse genomic sequence facilitates their functional analysis. However, comprehensive annotation of megabase-scale regions requires integration of vast amounts of information. We present a system for integrative analysis and demonstrate its utility on 1.2 Mb of sequence spanning the 20q13.2 breast cancer amplicon and 865 kb of syntenic: murine sequence. We integrate tumor genome copy number measurements with exhaustive genome landscape mapping, showing that amplicon boundaries are associated with maxima in repetitive element density and a region of evolutionary instability. This integration of comprehensive sequence annotation, quantitative expression analysis, and tumor amplicon boundaries provide evidence for an additional driver gene prefoldin 4 (PFDN4), coregulated genes, conserved noncoding regions, and associate repetitive elements with regions of genomic instability at this locus. C1 Univ Calif San Francisco, Ctr Canc, San Francisco, CA 94143 USA. Lawrence Berkeley Lab, Berkeley, CA 94143 USA. Joint Genome Inst, Dept Energy, Walnut Creek, CA 94958 USA. Novartis Agr Discovery Inst, San Diego, CA 92121 USA. Van Andel Inst, Grand Rapids, MI 49503 USA. RP Collins, C (reprint author), Univ Calif San Francisco, Ctr Canc, San Francisco, CA 94143 USA. RI Ylstra, Bauke/D-2906-2012 OI Ylstra, Bauke/0000-0001-9479-3010 FU NCI NIH HHS [CA 58207, P50 CA058207] NR 31 TC 67 Z9 74 U1 0 U2 3 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 JUN PY 2001 VL 11 IS 6 BP 1034 EP 1042 DI 10.1101/gr.GR1743R PG 9 WC Biochemistry & Molecular Biology; Biotechnology & Applied Microbiology; Genetics & Heredity SC Biochemistry & Molecular Biology; Biotechnology & Applied Microbiology; Genetics & Heredity GA 438GQ UT WOS:000169045600011 PM 11381030 ER PT J AU Hoskins, RA Phan, AC Naeemuddin, M Mapa, FA Ruddy, DA Ryan, JJ Young, LM Wells, T Kopczynski, C Ellis, MC AF Hoskins, RA Phan, AC Naeemuddin, M Mapa, FA Ruddy, DA Ryan, JJ Young, LM Wells, T Kopczynski, C Ellis, MC TI Single nucleotide polymorphism markers for genetic mapping in Drosophila melanogaster SO GENOME RESEARCH LA English DT Article ID GENOME PROJECT; MUTATIONS; RECOMBINATION; SEQUENCE; RATES; PCR AB For nearly a century, genetic analysis in Drosophila melanogaster has been a powerful tool for analyzing gene function, yet Drosophila lacks the molecular genetic mapping tools that recently have revolutionized human, mouse, and plant genetics. Here, we describe the systematic characterization of a dense set of molecular markers in Drosophila by using a sequence tagged site-based physical map of the genome. We identify 474 biallelic markers in standard laboratory strains of Drosophila that span the genome. Most of these markers are single nucleotide polymorphisms and sequences for these variants are provided in an accessible format. The average density of the new markers is one per 225 kb on the autosomes and one per megabase on the X chromosome. We include in this survey a set of P-element strains that provide additional use for high-resolution mapping. We show one application of the new markers in a simple set of crosses to map a mutation in the hedgehog gene to an interval of <1 Mb. This new map resource significantly increases the efficiency and resolution of recombination mapping and will be of immediate value to the Drosophila research community. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Genome Sci Dept, Berkeley, CA 94720 USA. Exelixis Inc, S San Francisco, CA 94083 USA. RP Hoskins, RA (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Genome Sci Dept, Berkeley, CA 94720 USA. FU NHGRI NIH HHS [P50-HG00750] NR 32 TC 68 Z9 76 U1 1 U2 7 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 JUN PY 2001 VL 11 IS 6 BP 1100 EP 1113 DI 10.1101/gr.GR-1780R PG 14 WC Biochemistry & Molecular Biology; Biotechnology & Applied Microbiology; Genetics & Heredity SC Biochemistry & Molecular Biology; Biotechnology & Applied Microbiology; Genetics & Heredity GA 438GQ UT WOS:000169045600017 PM 11381036 ER PT J AU Kim, J Gordon, L Dehal, P Badri, H Christensen, M Groza, M Ha, C Hammond, S Vargas, M Wehri, E Wagner, M Olsen, A Stubbs, L AF Kim, J Gordon, L Dehal, P Badri, H Christensen, M Groza, M Ha, C Hammond, S Vargas, M Wehri, E Wagner, M Olsen, A Stubbs, L TI Homology-driven assembly of a sequence-ready mouse BAC contig map spanning regions related to the 46-Mb gene-rich euchromatic segments of human chromosome 19 SO GENOMICS LA English DT Article ID PROXIMAL CHROMOSOME-7; FINGER PROTEIN; IMPRINTED GENE; GENOME; HUMAN-CHROMOSOME-19; IDENTIFICATION; MUTATIONS; 19Q13.4; SCALE; PEG3 AB Draft sequence derived from the 46-Mb gene-rich euchromatic portion of human chromosome 19 (HSA19) was utilized to generate a sequence-ready physical map spanning homologous regions of mouse chromosomes. Sequence similarity searches with the human sequence identified more than 1000 individual orthologous mouse genes from which 382 overgo probes were developed for hybridization. Using human gene order and spacing as a model, these probes were used to isolate and assemble bacterial artificial chromosome (BAC) clone contigs spanning homologous mouse regions. Each contig was verified, extended, and joined to neighboring contigs by restriction enzyme fingerprinting analysis. Approximately 3000 mouse BACs were analyzed and assembled into 44 contigs with a combined length of 41.4 Mb. These BAC contigs, covering 90% of HSA19-related mouse DNA, are distributed throughout 15 homology segments derived from different regions of mouse chromosomes 7, 8, 9, 10, and 17. The alignment of the HSA19 map with the ordered mouse BAC contigs revealed a number of structural differences in several overtly conserved homologous regions and more precisely defined the borders of the known regions of HSA19-syntenic homology. Our results demonstrate that given a human draft sequence, BAC contig maps can be constructed quickly for comparative sequencing without the need for preestablished mouse-specific genetic or physical markers and indicate that similar strategies can be applied with equal success to genomes of other vertebrate species. (C) 2001 Academic Press. C1 Dept Energy, Joint Genome Inst, Walnut Creek, CA 94598 USA. Univ Calif Lawrence Livermore Natl Lab, Genomics Div, Livermore, CA 94550 USA. RP Stubbs, L (reprint author), Dept Energy, Joint Genome Inst, 2800 Mitchell Dr, Walnut Creek, CA 94598 USA. OI Stubbs, Lisa/0000-0002-9556-1972 NR 27 TC 30 Z9 31 U1 0 U2 1 PU ACADEMIC PRESS INC PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0888-7543 J9 GENOMICS JI Genomics PD JUN 1 PY 2001 VL 74 IS 2 BP 129 EP 141 DI 10.1006/geno.2001.6521 PG 13 WC Biotechnology & Applied Microbiology; Genetics & Heredity SC Biotechnology & Applied Microbiology; Genetics & Heredity GA 440ML UT WOS:000169179000001 PM 11386749 ER PT J AU Horita, J AF Horita, J TI Carbon isotope exchange in the system CO2-CH4 at elevated temperatures SO GEOCHIMICA ET COSMOCHIMICA ACTA LA English DT Article ID MASS SPECTROMETER MEASUREMENTS; TRANSITION-METAL CATALYSIS; FISCHER-TROPSCH SYNTHESIS; METHANE-HYDROGEN-WATER; NATURAL-GAS; NEW-ZEALAND; HYDROTHERMAL CONDITIONS; EQUILIBRIUM-CONSTANTS; FRACTIONATION FACTORS; THERMAL AREAS AB Carbon isotope exchange was investigated for the system CO2-CH4 at 150 to 600 degreesC in the presence of several potential catalysts by use of isotopically normal or C-13-enriched gases. Silica gel, graphite, molecular sieve Linde 4A, magnetite, and hematite oxidized small amounts of CH4 in starting CO2-CH4 mixtures to CO2 and CO4 but failed to enhance the net rate of carbon isotope exchange between CO2 and CH4, even after 169 to 1833 h at 400 to 500 degreesC. In contrast, several commercial transition-metal catalysts (Ni, Pd, Ph, and Pt) promoted reactions significantly toward chemical and isotopic equilibrium. With the Ni catalyst, the attainment of carbon isotopic equilibrium between CO2 and CH4 was demonstrated for the first time at temperatures from 200 to 600 degreesC by complete isotopic reversal from opposite directions. The experimentally determined carbon isotope fractionation factors between CO2 and CH4 (10(3)ln alpha) were similar to, but slightly greater than (0.7-1.1 parts per thousand, 0.89 parts per thousand on average), those of statistical-mechanical calculations by Richet et al. (1977). The experimental results can be described by the following equation between 200 and 600 degreesC only. 10(3)ln alpha (CO2-CH4) = 26.70 - 49.137(10(3)/T) + 40.828(10(6)/T-2) - 7.512(10(9)/T-3) (T = 473.15-873.15 K, 1 sigma = +/-0.14 parts per thousand, n = 44). Alternatively, an equation generated by fitting Richet et al. (1977) data in the temperature range from 0 to 1300 degreesC can be modified by adding +0.89 parts per thousand to its constant; 10(3)ln alpha (CO2-CH4) = 0.16 + 11.754(10(6)/T-2) - 2.3655(10(9)/T-3) + 0.2054(10(12)T(4)) (T = 273-1573 K, 1 sigma = +/-0.21 parts per thousand, n = 44). This and other recent experimental studies in the literature demonstrate that transition metals, which are widespread in many natural materials, can catalyze reactions among natural gases at relatively low temperatures (less than or equal to 200 degreesC). The role of natural catalysts, "geocatalysts," in the abiogenic formation of methane, hydrocarbons, and simple organic compounds has important implications, ranging from the exploration of hydrocarbon resources to prebiotic organic synthesis. Copyright (C) 2001 Elsevier Science Ltd. C1 Oak Ridge Natl Lab, Div Chem & Analyt Sci, Oak Ridge, TN 37831 USA. RP Oak Ridge Natl Lab, Div Chem & Analyt Sci, POB 2008,MS 6110, Oak Ridge, TN 37831 USA. EM horitaj@ornl.gov NR 78 TC 75 Z9 77 U1 5 U2 25 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 JUN PY 2001 VL 65 IS 12 BP 1907 EP 1919 DI 10.1016/S0016-7037(01)00570-1 PG 13 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 443FK UT WOS:000169330000004 ER PT J AU Crowe, DE Riciputi, LR Bezenek, S Ignatiev, A AF Crowe, DE Riciputi, LR Bezenek, S Ignatiev, A TI Oxygen isotope and trace element zoning in hydrothermal garnets: Windows into large-scale fluid-flow behavior SO GEOLOGY LA English DT Article DE Russian Far East; ore deposits; skarn; stable isotopes; SIMS; hydrothermal systems ID ZONATION PATTERNS; STABLE-ISOTOPE; KING-ISLAND; HYDROGEN; MINERALS; SKARN; GEOCHEMISTRY; CARBON; RATIOS; ROCKS AB Single garnet crystals from a large, multicyclic hydrothermal system in Far East Russia are strongly growth zoned, Microscale ion microprobe analysis reveals consistent intracrystalline patterns in oxygen isotope composition and boron and iron contents, reflecting evolution of the hydrothermal system from magmatic- to meteoric-dominated conditions, and repetitive influx of magmatic fluids, Large intracrystalline variations in oxygen isotope composition (> 12 parts per thousand delta O-18) delimit temporal evolution of magmatic and meteoric fluid input within different portions of the hydrothermal system, and suggest that fluid-flow regimes differed between central and distal portions of the system. These results provide compelling evidence that microanalytical data can be extrapolated from intracrystalline scales to study macroscale processes in complex, large-scale fluid-rock systems. C1 Univ Georgia, Dept Geol, Athens, GA 30602 USA. Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. Univ Georgia, Dept Geol, Athens, GA 30602 USA. Russian Acad Sci, Far E Geol Inst, Vladivostok 690022, Russia. RP Crowe, DE (reprint author), Univ Georgia, Dept Geol, Athens, GA 30602 USA. NR 30 TC 14 Z9 21 U1 4 U2 12 PU GEOLOGICAL SOC AMERICA, INC PI BOULDER PA PO BOX 9140, BOULDER, CO 80301-9140 USA SN 0091-7613 J9 GEOLOGY JI Geology PD JUN PY 2001 VL 29 IS 6 BP 479 EP 482 DI 10.1130/0091-7613(2001)029<0479:OIATEZ>2.0.CO;2 PG 4 WC Geology SC Geology GA 438KK UT WOS:000169052100002 ER PT J AU Riebe, CS Kirchner, JW Granger, DE Finkel, RC AF Riebe, CS Kirchner, JW Granger, DE Finkel, RC TI Strong tectonic and weak climatic control of long-term chemical weathering rates SO GEOLOGY LA English DT Article DE geochemical mass balance; cosmogenic nuclides; chemical weathering rates; climate ID PUERTO-RICO; WATERSHEDS; EQUILIBRIUM; CALIFORNIA; DISCHARGE; SEDIMENT; BE-10; OCEAN AB The relationships among climate, physical erosion, and chemical weathering have remained uncertain, because long-term chemical weathering rates have been difficult to measure. Here we show that long-term chemical weathering rates can be measured by combining physical erosion rates, inferred from cosmogenic nuclides, with dissolution losses, inferred from the rock-to-soil enrichment of insoluble elements, We used this method to measure chemical weathering rates across 22 mountainous granitic catchments that span a wide range of erosion rates and climates, Chemical weathering rates correlate strongly with physical erosion rates but only weakly with climate, implying that, by regulating erosion rates, tectonic uplift may significantly accelerate chemical weathering rates in granitic landscapes. C1 Univ Calif Berkeley, Dept Earth & Planetary Sci, Berkeley, CA 94720 USA. Purdue Univ, Dept Earth & Atmospher Sci, W Lafayette, IN 47907 USA. Univ Calif Lawrence Livermore Natl Lab, Ctr Accelerator Mass Spectrometry, Livermore, CA 94551 USA. RP Riebe, CS (reprint author), Univ Calif Berkeley, Dept Earth & Planetary Sci, Berkeley, CA 94720 USA. RI Kirchner, James/B-6126-2009; Riebe, Clifford/B-7670-2012 OI Kirchner, James/0000-0001-6577-3619; NR 18 TC 183 Z9 187 U1 4 U2 66 PU GEOLOGICAL SOC AMERICA, INC PI BOULDER PA PO BOX 9140, BOULDER, CO 80301-9140 USA SN 0091-7613 J9 GEOLOGY JI Geology PD JUN PY 2001 VL 29 IS 6 BP 511 EP 514 DI 10.1130/0091-7613(2001)029<0511:STAWCC>2.0.CO;2 PG 4 WC Geology SC Geology GA 438KK UT WOS:000169052100010 ER PT J AU Scime, EE Littleton, JE Gary, SP Skoug, R Lin, NG AF Scime, EE Littleton, JE Gary, SP Skoug, R Lin, NG TI Solar cycle variations in the electron heat flux: Ulysses observations SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID VELOCITY DISTRIBUTION-FUNCTIONS; WIND ELECTRONS; PLASMA-EXPERIMENT; GLOBAL PROCESSES; MODEL; HELIOSPHERE; CORONA; WAVES; 1-AU AB Solar wind observations by the Ulysses spacecraft now include nearly ten years of continuous ion and electron measurements. In this study, we report detailed measurements of the electron heat flux in the solar wind. In particular, we examine the heat flux measurements for long-term correlations with wave activity and solar wind speed. We find that the average heat flux, when scaled by R-2.9 to account for variations due to distance from the Sun, is constant and independent of heliographic latitude or solar cycle. We find that during both solar maximum and solar minimum there is no significant correlation between the magnitude of the electron heat flux and the solar wind speed. Comparison of the electron heat flux data with wave activity indicates that the whistler heat flux instability does not play an important role in limiting the solar wind heat flux. C1 W Virginia Univ, Morgantown, WV 26506 USA. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Univ Minnesota, Minneapolis, MN USA. RP Scime, EE (reprint author), W Virginia Univ, Morgantown, WV 26506 USA. NR 22 TC 14 Z9 14 U1 1 U2 1 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 JUN 1 PY 2001 VL 28 IS 11 BP 2169 EP 2172 DI 10.1029/2001GL012925 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 434TB UT WOS:000168831000008 ER PT J AU Yin, L Winske, D Gary, SP Birn, J AF Yin, L Winske, D Gary, SP Birn, J TI Particle Hall-MHD simulation of collisionless reconnection: Ion gyro-radius correction SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID MAGNETOTAIL RECONNECTION; MAGNETIC RECONNECTION; HYBRID SIMULATIONS; DYNAMICS AB Fluid-ion dynamics from a Hall-MHD calculation and test ions that are advanced in Hall-MHD fields are compared to particle-ion dynamics from a hybrid simulation of two-dimensional reconnection in a thin current sheet. These comparisons demonstrate that off-diagonal terms of the ion pressure tenser are important to correctly model the ion out-of-plane momentum transport from the X point. These effects can be efficiently modeled in Hall-MHD simulations by advancing test ions in the Hall-MHD fields, accumulating the pressure tenser onto the spatial grid, and modifying the ion momentum equation. With ion gyro-radius corrections, the "particle Hall-MHD" simulation is shown to model accurately the ion out-of-plane momentum transport from the X point and the reconnection rate comparison with the hybrid simulation is improved. C1 Univ Calif Los Alamos Natl Lab, Div Appl Phys, Los Alamos, NM 87545 USA. RP Yin, L (reprint author), Univ Calif Los Alamos Natl Lab, Div Appl Phys, Mail Stop B259,Plasma Phys X1, Los Alamos, NM 87545 USA. NR 16 TC 7 Z9 7 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 JUN 1 PY 2001 VL 28 IS 11 BP 2173 EP 2176 DI 10.1029/2000GL012797 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 434TB UT WOS:000168831000009 ER PT J AU Riedi, J Goloub, P Marchand, RT AF Riedi, J Goloub, P Marchand, RT TI Comparison of POLDER cloud phase retrievals to active remote sensors measurements at the ARM SGP site. SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID TOP PHASE; NUCLEATION; RADAR AB In our present study, cloud boundaries derived from a combination of active remote sensors at the ARM SGP site are compared to POLDER cloud top phase index which is derived from polarimetric measurements using an innovative method. This approach shows the viability of the POLDER phase retrieval algorithm, and also leads to interesting results. In particular, the analysis demonstrates the sensitivity of polarization measurements to ice crystal shape and indicates that occurrence of polycrystalline ice clouds has to be taken into account in order to improve the POLDER phase retrieval algorithm accuracy. Secondly, the results show that a temperature threshold of 240 K could serve for cloud top particle phase classification. Considering the limitations of the analysis, the temperature threshold could be biased high, but not by more than about 5 degrees. C1 Univ Sci & Technol Lille, Opt Atmospher Lab, F-59655 Villeneuve Dascq, France. Pacific NW Natl Lab, Richland, WA USA. RP Riedi, J (reprint author), Univ Sci & Technol Lille, Opt Atmospher Lab, F-59655 Villeneuve Dascq, France. NR 12 TC 15 Z9 16 U1 3 U2 5 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 JUN 1 PY 2001 VL 28 IS 11 BP 2185 EP 2188 DI 10.1029/2000GL012758 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 434TB UT WOS:000168831000012 ER PT J AU Ulrich, TJ Darling, TW AF Ulrich, TJ Darling, TW TI Observation of anomalous elastic behavior in rock at low temperatures SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID SANDSTONE AB We have measured qualitative elastic properties of basalt and Berea sandstone from room temperature down to 4 K using Resonant Ultrasound Spectroscopy (RUS). A simple elastic solid should show a monotonic increase in the elastic constants as temperature decreases. The basalt samples show this gross behavior while the sandstone shows a very unexpected anomalous regime between 40 K and 200 K where the elastic constants decrease with decreasing temperature. Both rocks show temperature-dependent structure in both the modulus and internal friction, and also significant hysteresis, indicating history and rate-dependent properties. This data provides insight into the time and energy scales of dynamical effects observed in sandstones. The low temperature range (4K-300K) is of interest due to the renewed interest in Mars and Lunar rocks. C1 Univ Nevada, Dept Phys, Reno, NV 89557 USA. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Ulrich, TJ (reprint author), Univ Nevada, Dept Phys, 220, Reno, NV 89557 USA. NR 6 TC 17 Z9 18 U1 1 U2 7 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 JUN 1 PY 2001 VL 28 IS 11 BP 2293 EP 2296 DI 10.1029/2000GL012480 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 434TB UT WOS:000168831000039 ER PT J AU Masiello, CA Druffel, ERM AF Masiello, CA Druffel, ERM TI Carbon isotope geochemistry of the Santa Clara River SO GLOBAL BIOGEOCHEMICAL CYCLES LA English DT Article ID DISSOLVED ORGANIC-MATTER; BLACK CARBON; CONTINENTAL-SHELF; MARINE-SEDIMENTS; ELEMENTAL CARBON; OPEN-OCEAN; TRANSPORT; C-14; SYSTEM AB The Santa Clara River is a prototypical small mountainous river, with a headwater height greater than 1000 m and a basin area smaller than 10,000 m(2). Although individual small mountainous rivers export trivial amounts of sediment and carbon to the ocean, as a group these rivers may export a major fraction las much as 50%) of the total global river sediment flux [Milliman and Syvitski, 1992], making their geochemistry relevant the study of the ocean's carbon cycle. In addition, many small rivers export sediment in a few high flux events, causing massive, sporadic discharge of carbon onto coastal shelves, discharge conditions very different from those of large rivers. This class of rivers is an end-member of the river-ocean carbon exchange system, opposite the Earth's largest river, the Amazon. The carbon mass and isotopic properties of the Santa Clara River are significantly different from previously studied large rivers. During the 1997-1998 winter, all Santa Clara carbon pools were old, with flux-weighted average Delta (14)C values of -428 +/- 76 parts per thousand for particulate organic carbon, -73 +/- 31 parts per thousand for dissolved organic carbon, and -644 +/- 58 parts per thousand for black carbon. The age of exported carbon is primarily due to the deep erosion of old soils and not to inclusion of fossil fuel carbon. Additionally, the delta (13)C signatures of exported carbon pools were high relative to terrestrial carbon, bearing a signature quite similar to marine carbon (average particulate organic carbon (POC) delta (13)C = -22.2 +/- 0.8 parts per thousand). The Santa Clara's estuary is small and drains onto the narrow eastern Pacific coastal margin, exporting this old soil organic matter directly into the ocean. If the Santa Clara export patterns are representative of this class of rivers, they may be a significant source of refractory terrestrial carbon to the ocean. C1 Lawrence Livermore Natl Lab, Ctr Accelerator Mass Spectrometry, Livermore, CA 94550 USA. Univ Calif Irvine, Dept Earth Syst Sci, Irvine, CA 92697 USA. RP Masiello, CA (reprint author), Lawrence Livermore Natl Lab, Ctr Accelerator Mass Spectrometry, L-397,7000 East Ave,POB 808, Livermore, CA 94550 USA. EM masiello1@llnl.gov RI Masiello, Caroline/A-2653-2011 OI Masiello, Caroline/0000-0003-2102-6229 NR 34 TC 119 Z9 130 U1 3 U2 25 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0886-6236 J9 GLOBAL BIOGEOCHEM CY JI Glob. Biogeochem. Cycle PD JUN PY 2001 VL 15 IS 2 BP 407 EP 416 DI 10.1029/2000GB001290 PG 10 WC Environmental Sciences; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences SC Environmental Sciences & Ecology; Geology; Meteorology & Atmospheric Sciences GA 441MB UT WOS:000169233200011 ER PT J AU Daugherty, NM Falk, RB Furman, FJ Aldrich, JM Hilmas, DE AF Daugherty, NM Falk, RB Furman, FJ Aldrich, JM Hilmas, DE TI Former radiation worker medical surveillance program at Rocky Flats SO HEALTH PHYSICS LA English DT Article DE monitoring, personnel; radiation protection; exposure, occupational; plutonium AB The United States Department of Energy (DOE), Office of Occupational Medicine and Medical Surveillance, has supported an ongoing Former Radiation Worker Medical Surveillance Program at the DOE Rocky Flats site since 1992, The program currently is managed for DOE by Oak Ridge Institute for Science and Education through a contract with Oak Ridge Associated Universities, Participation in the program is entirely voluntary and provides former Rocky Flats workers who were exposed to radiation with long-term medical monitoring and an update to the assessment of their radiation dose. Program participants receive medical examinations and kt vivo and irt vitro bioassay measurements of residual radioactivity. Radiation doses to participants are largely a result of internal depositions of plutonium and its radioactive decay products. The causes of many of the higher internal doses were accidents that generally are well documented, Former radiation workers are invited to participate in the program if they meet specific criteria for radiation exposure. Informed consent is documented using a consent form approved by an Institutional Review Board. Demographic, medical, and dosimetric information is maintained in a computer database and will be evaluated for any trends or correlations between exposure and health outcome. C1 Oak Ridge Associated Univ, Arvada, CO 80005 USA. NR 11 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 JUN PY 2001 VL 80 IS 6 BP 544 EP 551 DI 10.1097/00004032-200106000-00004 PG 8 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 436TX UT WOS:000168952900004 PM 11388723 ER PT J AU Little, TT Miller, G Inkret, WC Schillaci, ME Martz, HF AF Little, TT Miller, G Inkret, WC Schillaci, ME Martz, HF TI Bayesian formulations are not appropriate for a priori specification of analytic detection capabilities - Response SO HEALTH PHYSICS LA English DT Letter C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 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 JUN PY 2001 VL 80 IS 6 BP 621 EP 621 PG 1 WC Environmental Sciences; Public, Environmental & Occupational Health; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Environmental Sciences & Ecology; Public, Environmental & Occupational Health; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA 436TX UT WOS:000168952900018 ER PT J AU Jones, DS AF Jones, DS TI Background ecological risks: When and how to weigh in SO HUMAN AND ECOLOGICAL RISK ASSESSMENT LA English DT Letter C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Jones, DS (reprint author), Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. NR 4 TC 3 Z9 3 U1 0 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 JUN PY 2001 VL 7 IS 3 BP 635 EP 638 PG 4 WC Biodiversity Conservation; Environmental Sciences SC Biodiversity & Conservation; Environmental Sciences & Ecology GA 450NY UT WOS:000169751100005 ER PT J AU Freund, HP Biedron, SG Milton, SV Nuhn, HD AF Freund, HP Biedron, SG Milton, SV Nuhn, HD TI The effect of wiggler imperfections on nonlinear harmonic generation in free-electron lasers SO IEEE JOURNAL OF QUANTUM ELECTRONICS LA English DT Article DE electromagnetic radiation; electron beam applications; free-electron lasers; frequency conversion; frequency-domain analysis; nonlinearities; nonlinear differential equations; simulation ID CODE AB The generation of harmonics through a nonlinear mechanism driven by bunching at the fundamental has sparked interest in using this process as a path toward an X-ray free-electron laser (FEL). An important issue in this regard is the sensitivity of the nonlinear harmonic generation to wiggler imperfections. Typically, linear instabilities in FELs are characterized by increasing sensitivity to both electron beam and wiggler quality with increasing harmonic number. However, since the nonlinear harmonic generation mechanism is driven by the growth of the fundamental, the sensitivity of the nonlinear harmonic mechanism is not severely greater than that of the fundamental. in this paper, we study the effects of wiggler imperfections on the nonlinear harmonics in a 1.5-Angstrom FEL, and show that the decline in the third harmonic emission with increasing levels of niggler imperfections roughly tracks that of the fundamental. C1 Sci Applicat Int Corp, Mclean, VA 22102 USA. Argonne Natl Lab, Adv Photon Source, Argonne, IL 60439 USA. Univ Lund, MAX Lab, S-22100 Lund, Sweden. Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. RP Freund, HP (reprint author), Sci Applicat Int Corp, Mclean, VA 22102 USA. NR 13 TC 6 Z9 6 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 0018-9197 J9 IEEE J QUANTUM ELECT JI IEEE J. Quantum Electron. PD JUN PY 2001 VL 37 IS 6 BP 790 EP 793 DI 10.1109/3.922776 PG 4 WC Engineering, Electrical & Electronic; Optics; Physics, Applied SC Engineering; Optics; Physics GA 431GN UT WOS:000168623600007 ER PT J AU Cohen, MI Allerman, AA Choquette, KD Jagadish, C AF Cohen, MI Allerman, AA Choquette, KD Jagadish, C TI Electrically steerable lasers using wide-aperture VCSELs SO IEEE PHOTONICS TECHNOLOGY LETTERS LA English DT Article DE beam steering; free space optical interconnect; vertical-cavity surface-emitting laser ID SURFACE-EMITTING LASERS; MODES AB A wide-aperture vertical-cavity surface-emitting laser has been fabricated so as to enhance the transverse mode selection. It was found that the far field emission can be made to exhibit two distinct steerable beams. The laser beams may be steered from 30 degrees away from the normal right up to normal emission by varying the driving current. The steering effect is a thermal effect as confirmed by transient waveform analysis. A two-channel switch was built with switching time between channels of 10 mus and crosstalk of greater than 18 dB. C1 Australian Natl Univ, Res Sch Phys Sci & Engn, Dept Elect Mat Engn, Canberra, ACT, Australia. Sandia Natl Labs, Albuquerque, NM 88448 USA. RP Cohen, MI (reprint author), Australian Natl Univ, Res Sch Phys Sci & Engn, Dept Elect Mat Engn, GPO Box 4, Canberra, ACT, Australia. NR 12 TC 10 Z9 10 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 1041-1135 J9 IEEE PHOTONIC TECH L JI IEEE Photonics Technol. Lett. PD JUN PY 2001 VL 13 IS 6 BP 544 EP 546 DI 10.1109/68.924014 PG 3 WC Engineering, Electrical & Electronic; Optics; Physics, Applied SC Engineering; Optics; Physics GA 434UB UT WOS:000168833300002 ER PT J AU Schwenterly, SW Demko, JA Lue, JW Walker, MS Reis, CT Hazelton, DW Shi, X Gardner, MT AF Schwenterly, SW Demko, JA Lue, JW Walker, MS Reis, CT Hazelton, DW Shi, X Gardner, MT TI AC loss measurements with a cryocooled sample SO IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY LA English DT Article DE cryogenics; high-temperature superconductors; loss measurement; transformer windings AB A new cryostat cooled by a closed-cycle Cryomech GB-37 cryocooler for superconductor measurements at temperatures down to 20 K is described. The sample is conductively coupled to the cold stage so as to minimize vibration and thermal stresses. AC losses have been measured calorimetrically in several high-temperature superconductors coils that have been wound to simulate subscale transformer winding pairs. Stable temperatures down to 20 K were reached on these coils, allowing measurements at practical levels of ac current and I-c. By using short ac current pulses, losses on individual turns could be resolved. Results are reported mainly to showcase the apparatus, measurement procedure, and analytical approach. C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. IGC SuperPower, Schenectady, NY 12304 USA. RP Schwenterly, SW (reprint author), Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. NR 4 TC 3 Z9 3 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 1051-8223 J9 IEEE T APPL SUPERCON JI IEEE Trans. Appl. Supercond. PD JUN PY 2001 VL 11 IS 2 BP 4027 EP 4031 DI 10.1109/77.947379 PG 5 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA 469FQ UT WOS:000170804300004 ER PT J AU Merten, MC Trick, AR Barnes, RD Nystrom, ME George, CN Gyllenhaal, JC Hsu, WMW AF Merten, MC Trick, AR Barnes, RD Nystrom, ME George, CN Gyllenhaal, JC Hsu, WMW TI An architectural framework for runtime optimization SO IEEE TRANSACTIONS ON COMPUTERS LA English DT Article DE postlink optimization; runtime optimization; dynamic optimization; hardware profiling; low-overhead profiling; code layout; program hot spot; partial function inlining; trace formation and optimization ID COMPILATION; PROCESSORS; SUPPORT AB Wide-issue processors continue to achieve higher performance by exploiting greater instruction-level parallelism. Dynamic techniques such as out-of-order execution and hardware speculation have proven effective at increasing instruction throughput. Runtime optimization promises to provide an even higher level of performance by adaptively applying aggressive code transformations on a larger scope. This paper presents a new hardware mechanism for generating and deploying runtime optimized code. The mechanism can be viewed as a filtering system that resides in the retirement stage of the processor pipeline, accepts an instruction execution stream as input, and produces instruction profiles and sets of linked, optimized traces as output. The code deployment mechanism uses an extension to the branch prediction mechanism to migrate execution into the new code without modifying the original code. These new components do not add delay to the execution of the program except during short bursts of reoptimization. This technique provides a strong platform for runtime optimization because the hot execution regions are extracted, optimized, and written to main memory for execution and because these regions persist across context switches. The current design of the framework supports a suite of optimizations, including partial function inlining (even into shared libraries), code straightening optimizations, loop unrolling, and peephole optimizations. C1 Univ Illinois, Ctr Reliable & High Performance Comp, Urbana, IL 61801 USA. Hewlett Packard Corp, Cupertino, CA 95014 USA. Lawrence Livermore Natl Lab, Dept Computat, Livermore, CA 94551 USA. RP Univ Illinois, Ctr Reliable & High Performance Comp, 1308 W Main St, Urbana, IL 61801 USA. EM merten@crhc.uiuc.edu; andrew_trick@hp.com; rdbarnes@crhc.uiuc.edu; nystrom@crhc.uiuc.edu; c-george@uiuc.edu; gyllen@lnl.gov; hwu@crhc.uiuc.edu NR 34 TC 28 Z9 30 U1 1 U2 1 PU IEEE COMPUTER SOC PI LOS ALAMITOS PA 10662 LOS VAQUEROS CIRCLE, PO BOX 3014, LOS ALAMITOS, CA 90720-1314 USA SN 0018-9340 EI 1557-9956 J9 IEEE T COMPUT JI IEEE Trans. Comput. PD JUN PY 2001 VL 50 IS 6 BP 567 EP 589 DI 10.1109/12.931894 PG 23 WC Computer Science, Hardware & Architecture; Engineering, Electrical & Electronic SC Computer Science; Engineering GA 445HQ UT WOS:000169452400004 ER PT J AU Zaidi, SH Ruby, DS Gee, JM AF Zaidi, SH Ruby, DS Gee, JM TI Characterization of random reactive ion etched-textured silicon solar cells SO IEEE TRANSACTIONS ON ELECTRON DEVICES LA English DT Article DE antireflection surfaces; random RIE texturing; Si solar cells ID SURFACE; DAMAGE; SI; CHF3/C2F6; WAFER AB Hemispherical reflectance and internal quantum efficiency (IQE) measurements have been employed to evaluate the response of Si nanostructured surfaces formed by using reactive ion etching (RIE) random texturing techniques. Random RIE-textured surfaces typically exhibit broadband anti-reflection behavior with solar-weighted-reflectance (SWR) of approximate to3% over 300-1200-nm spectral range. RIE-texturing has been demonstrated over large areas (similar to 180 cm(2)) of both single and multicrystalline Si substrates. Due to the surface contamination and plasma-induced damage, as formed RIE-textured solar cells do not provide enhanced short-circuit current. However, improved surface cleaning combined with controlled wet-chemical damage removal etches provide a significant improvement in the short-circuit current. For such textures, the internal quantum efficiencies are comparable to the random, wet-chemically-textured solar cells. In both the W and near-IR wavelength regions, the RTE-textured subwavelength surfaces exhibit superior performance in comparison with the wet-chemically-textured surfaces. Due to their large area, low-reflection capability, random, RIE-texturing techniques are expected to find widespread commercial applicability in low-cost, large-area multicrystalline Si solar cells. C1 Gratings Inc, Albuquerque, NM 87107 USA. Sandia Natl Labs, Photovoltaic Syst Components Dept, Albuquerque, NM 87185 USA. RP Zaidi, SH (reprint author), Gratings Inc, Albuquerque, NM 87107 USA. NR 21 TC 91 Z9 91 U1 3 U2 31 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 JUN PY 2001 VL 48 IS 6 BP 1200 EP 1206 DI 10.1109/16.925248 PG 7 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA 438GD UT WOS:000169044500028 ER PT J AU Hsu, JS AF Hsu, JS TI Flux guides for permanent magnet machines SO IEEE TRANSACTIONS ON ENERGY CONVERSION LA English DT Article DE effective flux enhancements; electric vehicle; flux guides; generators; intrinsic demagnetization; leakage flux; motors; permanent-magnet machines AB A study for the enhancement of effective flux of PM machines using flux guides is presented. An intrinsic demagnetization curve that considers the leakage flux is introduced. On the basis of a higher effective flux the stator winding can be more compact; consequently, a lighter stator and a higher efficiency permanent magnet (PM) machine can be obtained. C1 Oak Ridge Natl Lab, Natl Transportat Res Ctr, Knoxville, TN 37932 USA. RP Hsu, JS (reprint author), Oak Ridge Natl Lab, Natl Transportat Res Ctr, 2360 Cherahala Blvd, Knoxville, TN 37932 USA. NR 7 TC 4 Z9 4 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 0885-8969 J9 IEEE T ENERGY CONVER JI IEEE Trans. Energy Convers. PD JUN PY 2001 VL 16 IS 2 BP 186 EP 191 DI 10.1109/60.921471 PG 6 WC Energy & Fuels; Engineering, Electrical & Electronic SC Energy & Fuels; Engineering GA 431GA UT WOS:000168622400012 ER PT J AU Hsu, JS AF Hsu, JS TI Hybrid-secondary uncluttered induction (HSU-I) machine SO IEEE TRANSACTIONS ON ENERGY CONVERSION LA English DT Article DE adjustable-speed drives; doubly fed; generators; HSU-I; hybrid secondary; induction motors; magnetically switched; slip-energy control; uncluttered AB A new hybrid-secondary uncluttered induction (HSU-I) machine is introduced. The hybrid secondary includes the effective-resistance, inverter, and magnetic switch options. The rotor current is magnetically coupled to the stator through an uncluttered rotating transformer. This machine can be used as a cost-effective slip-energy-controlled adjustable-speed induction motor that operates below synchronism and the widespeed-range motor drives and generators that operate below and above the synchronous speed of the line frequency. C1 Oak Ridge Natl Lab, Power Elect & Elect Machine Res Ctr, Oak Ridge, TN 37831 USA. RP Hsu, JS (reprint author), Oak Ridge Natl Lab, Power Elect & Elect Machine Res Ctr, POB 2009,MS 8038, Oak Ridge, TN 37831 USA. NR 8 TC 1 Z9 1 U1 0 U2 2 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0885-8969 J9 IEEE T ENERGY CONVER JI IEEE Trans. Energy Convers. PD JUN PY 2001 VL 16 IS 2 BP 192 EP 197 DI 10.1109/60.921472 PG 6 WC Energy & Fuels; Engineering, Electrical & Electronic SC Energy & Fuels; Engineering GA 431GA UT WOS:000168622400013 ER PT J AU Luke, PN Amman, M Lee, JS Manfredi, PF AF Luke, PN Amman, M Lee, JS Manfredi, PF TI Noise in CdZnTe detectors SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT Annual Nuclear Science Symposium (NSS) CY OCT 15-20, 2000 CL LYON, FRANCE SP IEEE, CEA, IN2P3, CERN DE CdZnTe; gamma-ray detectors; noise; semiconductor radiation detectors ID SEMICONDUCTOR; SPECTROMETERS; SPECTRA AB Noise in CdZnTe devices with different electrode configurations was investigated. Measurements on devices with guard-ring electrode structures showed that surface leakage current does not produce any significant noise. The parallel white noise component of the devices appeared to be generated by the bulk current alone, even though the surface current was substantially higher. This implies that reducing the surface leakage current of a CdZnTe detector may not necessarily result in a significant improvement in noise performance. The noise generated by the bulk current is also observed to be below full shot noise. This partial suppression of shot noise may be the result of Coulomb interaction between carriers or carrier trapping. Devices with coplanar strip electrodes were observed to produce a 1/f noise term at the preamplifier output. Higher levels of this 1/f noise were observed with decreasing gap widths between electrodes. The level of this 1/f noise appeared to be independent of bias voltage and leakage current but was substantially reduced after certain surface treatments. C1 Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. Univ Pavia, Dipartimento Elettron, I-27100 Pavia, Italy. RP Luke, PN (reprint author), Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. NR 10 TC 23 Z9 23 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 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD JUN PY 2001 VL 48 IS 3 BP 282 EP 286 DI 10.1109/23.940066 PG 5 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA 465EG UT WOS:000170576200011 ER PT J AU Lopes, JAM dos Santos, JMF Morgado, RE Conde, CAN AF Lopes, JAM dos Santos, JMF Morgado, RE Conde, CAN TI A xenon gas proportional scintillation counter with a UV-sensitive large-area avalanche photodiode SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT Annual Nuclear Science Symposium (NSS) CY OCT 15-20, 2000 CL LYON, FRANCE SP IEEE, CEA, IN2P3, CERN ID X-RAY SPECTROMETRY; VUV PHOTOSENSOR; INTEGRATED PHOTOSENSOR; SILICON PHOTODIODES; ENERGY RESOLUTION; PERFORMANCE; CHAMBER AB The performance characteristics of a xenon gas proportional scintillation counter comprising a large-area avalanche photodiode with enhanced ultraviolet sensitivity were evaluated. By integrating the photodiode within the xenon gas envelope of the scintillator, the intervening quartz window was eliminated. Energy resolutions of 7.8% and 4.4% were measured for 5.9- and 22.1-keV X-rays, respectively. The results demonstrate that large-area avalanche photodiodes may replace photomultiplier tubes without compromising the performance of the gas proportional scintillation counter. C1 Inst Super Engn Coimbra, P-3031601 Coimbra, Portugal. Univ Coimbra, Dept Phys, P-3004516 Coimbra, Portugal. Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Lopes, JAM (reprint author), Inst Super Engn Coimbra, P-3031601 Coimbra, Portugal. RI matias-lopes, jose/H-6074-2012; dos Santos, Joaquim/B-3058-2015; OI matias-lopes, jose/0000-0002-6366-2963; Conde, Carlos/0000-0002-1387-2161; dos Santos, Joaquim Marques Ferreira/0000-0002-8841-6523 NR 21 TC 29 Z9 29 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 JUN PY 2001 VL 48 IS 3 BP 312 EP 319 DI 10.1109/23.940072 PG 8 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA 465EG UT WOS:000170576200017 ER PT J AU Yu, B Mahler, GJ Schaknowski, NA Smith, GC AF Yu, B Mahler, GJ Schaknowski, NA Smith, GC TI A position-sensitive ionization chamber for thermal neutrons SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT Annual Nuclear Science Symposium (NSS) CY OCT 15-20, 2000 CL LYON, FRANCE SP IEEE, CEA, IN2P3, CERN DE ionization chambers; neutron detectors; position sensitive particle detectors AB A position-sensitive neutron detector based on (3)He is being developed for a national crystal backscattering spectrometer (CBS) at a pulsed neutron source. It comprises a single gas volume, of constant depth, in the form of an annulus that is also part of a truncated cone. Charge from each event is collected on one or two anode strips, out of a total 336 around the annulus, yielding an angular resolution of about 1 degrees. Low-noise signal processing, in the form of a monolithic preamplifier/shaping amplifier connected to each anode strip, provides electronic noise that is small enough to permit detector operation in ionization mode. In addition, the segmented anodes ensure near complete induced charge collection. This new detector therefore has significant advantages over previous detectors used in CBS instruments, which primarily consisted of arrays of individual (3)He filled cylindrical counters with dead regions and nonuniform detection efficiency. The optimization of gas mixture/pressure, drift field, and shaping. time is significant in achieving successful performance in the new detector. C1 Brookhaven Natl Lab, Upton, NY 11973 USA. RP Yu, B (reprint author), Brookhaven Natl Lab, Upton, NY 11973 USA. NR 6 TC 6 Z9 6 U1 0 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855-4141 USA SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD JUN PY 2001 VL 48 IS 3 BP 336 EP 340 DI 10.1109/23.940076 PG 5 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA 465EG UT WOS:000170576200021 ER PT J AU Reeder, PL Bowyer, SM AF Reeder, PL Bowyer, SM TI Fast neutron and alpha detection using LiBaF3 scintillator SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT Annual Nuclear Science Symposium (NSS) CY OCT 15-20, 2000 CL LYON, FRANCE SP IEEE, CEA, IN2P3, CERN DE alpha detection; LiBaF3 crystal; neutron detection; scintillation counting ID CRYSTALS AB Pulse-shape discrimination techniques using the scintillator LiBaF3 allow very clean separation of densely ionizing radiation (protons, tritons, alphas, etc.) from less densely ionizing radiation (electrons). The pulse-shape discrimination is based on the presence or absence of subnanosecond core-valence luminescence and in crystals doped with Ce+3 the presence or absence of Ce luminescence. We use a pulse discrimination technique based on integration of the signal over a short time interval compared to integration over a long time interval. Thermal neutron capture events, fast neutron capture events, fast neutron elastic scattering events on Li, and alpha events from Ra impurities in the scintillator have distinctive loci in a two-dimensional plot of the short-gate pulse heights versus long-gate pulse heights. The resolution (full-width at half-maximum) of the (CS)-C-137 gamma photopeak is about 16%, and the resolution of the thermal neutron peak from neutron capture on Li-6 is about 17%. Applications of this scintillator include measurements of fast to thermal neutron ratios, fast neutron spectroscopy, alpha contamination, etc., in the presence of significant gamma radiation. C1 Pacific NW Natl Lab, Richland, WA 99352 USA. RP Reeder, PL (reprint author), Pacific NW Natl Lab, Richland, WA 99352 USA. NR 7 TC 5 Z9 5 U1 0 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 JUN PY 2001 VL 48 IS 3 BP 351 EP 355 DI 10.1109/23.940079 PG 5 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA 465EG UT WOS:000170576200024 ER PT J AU Fabris, L Becker, JA Goulding, FS Madden, NW AF Fabris, L Becker, JA Goulding, FS Madden, NW TI Simultaneous ballistic deficit immunity and resilience to parallel noise sources: A new pulse shaping technique SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT Annual Nuclear Science Symposium (NSS) CY OCT 15-20, 2000 CL LYON, FRANCE SP IEEE, CEA, IN2P3, CERN DE ballistic deficit; pulse shaping; signal-to-noise optimization; time-variant filters ID DETECTORS AB A new and different time-variant pulse processing system has been developed based on a simple CR-RC filter and two analog switches. The new pulse processing technique combines both ballistic deficit immunity and resilience to parallel noise without a significant compromise to the low energy resolution, generally considered a mutually exclusive requirement. The filter is realized by combining two different pulse shaping techniques. One of the techniques creates a low rate of curvature at the pulse peak, which reduces ballistic deficit, while the second technique increases the tolerance to low-frequency noise by modifying the noise history. Several experimental measurements are presented, including tests on a coplanar grid CdZnTe detector. Improvements on both the resolution and line shape are shown for the 662 keV line of Cs-137. C1 Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Fabris, L (reprint author), Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. RI Fabris, Lorenzo/E-4653-2013 OI Fabris, Lorenzo/0000-0001-5605-5615 NR 14 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 JUN PY 2001 VL 48 IS 3 BP 450 EP 454 DI 10.1109/23.940098 PG 5 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA 465EG UT WOS:000170576200043 ER PT J AU Pedrali-Noy, M Grubre, G Krieger, B Mandelli, E Meddeler, G Moses, W Rosso, V AF Pedrali-Noy, M Grubre, G Krieger, B Mandelli, E Meddeler, G Moses, W Rosso, V TI PETRIC - A positron emission tomography readout integrated circuit SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT Annual Nuclear Science Symposium (NSS) CY OCT 15-20, 2000 CL LYON, FRANCE SP IEEE, CEA, IN2P3, CERN DE front-end electronics; integrated circuit design; low noise; mixed signal; preamplifier; pulse shaper; winner-take-all ID DETECTORS; PREAMPLIFIER AB We present the architecture, critical design issues, and performance measurements of PETRIC, a 64-channel mixed signal front-end integrated circuit for reading out a photodiode array coupled with Lu(2)SiOr(5) [Ce] scintillator crystals for a medical imaging application: positron emission topography. Each channel consists of a low-noise charge-sensitive preamplifter, an RC-CR pulse shaper and a winner-take-all multiplexer that selects the channel with the largest input signal. Triggered by an external timing signal, a switch opens and a capacitor stores the peak voltage of the winner channel. The shaper peaking time is adjustable by means of external current inputs over a continuous range of 0.7 mus to 9 mus. Power consumption is 5.4 mW per channel, measured equivalent noise charge at 1-mus peaking time, zero leakage current is 33 rms electrons plus 7.3 rms electrons per pF of input capacitance. Design is fabricated in 0.5-mum 3.3-V complementary metal-oxide semiconductor technology. C1 Lawrence Berkeley Natl Lab, Integrated Syst Grp, Berkeley, CA 94709 USA. Univ Pisa, Dipartimento Fis, I-56010 Pisa, Italy. Sez INFN, I-56010 Pisa, Italy. RP Pedrali-Noy, M (reprint author), Qualcomm, San Diego, CA 92121 USA. NR 15 TC 24 Z9 25 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 JUN PY 2001 VL 48 IS 3 BP 479 EP 484 DI 10.1109/23.940103 PG 6 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA 465EG UT WOS:000170576200048 ER PT J AU Hoff, JR Mekkaoui, A Christian, DC Zimmerman, S Cancelo, G Kasper, P Yarema, R AF Hoff, JR Mekkaoui, A Christian, DC Zimmerman, S Cancelo, G Kasper, P Yarema, R TI PreFPIX2: Core architecture and results SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT Annual Nuclear Science Symposium (NSS) CY OCT 15-20, 2000 CL LYON, FRANCE SP IEEE, CEA, IN2P3, CERN DE deep submicron CMOS; pixel electronics; radiation tolerant VLSI design AB FPIX is a pixel architecture designed for colliding-beam experiments at the Tevatron. Its most important application to date is the BTeV experiment. PreFPIX2 is a chip designed to test the FPIX Core, i.e., the pixel control and readout architecture. This FPIX Core will be mated to a Periphery specific to a particular experiment. Earlier plans called for the BTeV FPIX chip to be designed in a rad-hard process. However, deep-submicron CMOS processes have demonstrated appropriate radiation tolerance at a lower cost and with greater reliability. Therefore, PreFPIX2 has been fabricated in a 0.25 micrometer process utilizing radiation tolerant design techniques. The architecture has undergone substantial development from earlier versions of FPIX. Most notable are the improvements to the column token passing scheme and to the end-of-column logic. Extensive simulations were performed using both SPICE and structural-level Verilog. Monte Carlo physics simulations of the BTeV pixel detector at half, full and double the planned luminosity were converted to Verilog compatible input files for the chip simulations, allowing the designers to observe the chip operating under real conditions and for extended periods of time. Analyzes of the results reveal that at all luminosities the FPIX Core correctly identifies better than 99.6% of input hits. Bench tests of fabricated chips confirm the accuracy of the simulations. C1 Fermilab Natl Accelerator Lab, Batavia, IL 60510 USA. RP Hoff, JR (reprint author), Fermilab Natl Accelerator Lab, POB 500, Batavia, IL 60510 USA. NR 7 TC 8 Z9 8 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 JUN PY 2001 VL 48 IS 3 BP 485 EP 492 DI 10.1109/23.940104 PG 8 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA 465EG UT WOS:000170576200049 ER PT J AU Krieger, B Ewell, K Ludewigt, BA Maier, MR Markovic, D Milgrome, O Wang, YJ AF Krieger, B Ewell, K Ludewigt, BA Maier, MR Markovic, D Milgrome, O Wang, YJ TI An 8 x 8 pixel IC for X-ray spectroscopy SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT Annual Nuclear Science Symposium (NSS) CY OCT 15-20, 2000 CL LYON, FRANCE SP IEEE, CEA, IN2P3, CERN ID PREAMPLIFIER-SHAPER; CMOS PREAMPLIFIER; TIME AB An integrated circuit (IC) providing 64 channels of low-noise signal processing electronics in an 8 x 8 pixel arrangement has been developed as part of an integrated silicon detector array for high count-rate X-ray spectroscopy applications. Each pixel features low-noise charge integration, programmable peaking time and gain, and an output driver. The 8 x 8 pixel IC builds upon our previous development of the XPS chip, a 1-dimensional (1-D) preamplifier-shaper IC for linear silicon detector arrays. The new pixel design features significant improvements to the shaper and output driver stages, including digital peaking time and gain selection, and a low-power charge driver/receiver design. When operated with a cooled, low-capacitance silicon detector, an energy resolution of similar to 210 eV FWHM was obtained for 5.89 keV X-rays. The power dissipation is similar to6 mW per pixel at a supply voltage of 3.3 V. C1 Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. Univ Calif Berkeley, Berkeley, CA 94720 USA. Adv Res & Applicat Corp ARACOR, Sunnyvale, CA 94086 USA. RP Krieger, B (reprint author), Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. NR 9 TC 22 Z9 22 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 JUN PY 2001 VL 48 IS 3 BP 493 EP 498 DI 10.1109/23.940105 PG 6 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA 465EG UT WOS:000170576200050 ER PT J AU Denes, P Bussat, JM Lustermann, W Mathez, H Pangaud, P Walder, JP AF Denes, P Bussat, JM Lustermann, W Mathez, H Pangaud, P Walder, JP TI Light-to-light readout system of the CMS electromagnetic calorimeter SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT Annual Nuclear Science Symposium (NSS) CY OCT 15-20, 2000 CL LYON, FRANCE SP IEEE, CEA, IN2P3, CERN ID LOW-POWER AB For the Compact Muon Solenoid (CMS) experiment at the Large Hadron Collider (LHC) at CERN, an 80 000-crystal electromagnetic calorimeter will measure electron and photon energies with high precision over a dynamic range of roughly 16 bits. The readout electronics will be located directly behind the crystals, and must survive a total dose of up to 2 x 10(4) Gy along with 5 x 10(13) n/cm(2). A readout chain consisting of a custom wide-range acquisition circuit, commercial ADC and custom optical link for each crystal is presently under construction. An overview of the design is presented, with emphasis on the large-scale fiber communication system. C1 Princeton Univ, Dept Phys, Princeton, NJ 08544 USA. ETH Zurich, CH-8093 Zurich, Switzerland. Inst Phys Nucl, F-69622 Villeurbanne, France. RP Denes, P (reprint author), Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. NR 11 TC 1 Z9 1 U1 0 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD JUN PY 2001 VL 48 IS 3 BP 499 EP 503 DI 10.1109/23.940106 PG 5 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA 465EG UT WOS:000170576200051 ER PT J AU Andresen, J Bishai, M Cancelo, G Derylo, G Ely, R Franzen, J Garcia-Sciveres, M Gotra, Y Kwarciany, R Perez, J Shenai, A Shepard, P Treptow, K Zimmermann, S AF Andresen, J Bishai, M Cancelo, G Derylo, G Ely, R Franzen, J Garcia-Sciveres, M Gotra, Y Kwarciany, R Perez, J Shenai, A Shepard, P Treptow, K Zimmermann, S TI The port card for the silicon vertex detector upgrade of the collider detector at Fermilab SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT Annual Nuclear Science Symposium (NSS) CY OCT 15-20, 2000 CL LYON, FRANCE SP IEEE, CEA, IN2P3, CERN DE electronics; multichip modules; silicon radiation detectors; vertex detectors ID READOUT AB The collider detector, at Fermilab is approaching the completion of the silicon vertex detector upgrade for Run II. The port card is a Beryllia multichip module developed to control, read out, and regulate power for the silicon strip readout chips. It has two radiation hard application-specific integrated circuits, parallel fiber-optic transmitters, and voltage regulators. It resides 14 cm from the accelerator beam inside the tracking volume. The function and location of the port card impose severe constraints on its design. This paper presents the port card and describes the adopted solutions to address the main design issues, as well as the result of many characterization tests. C1 Fermilab Natl Accelerator Lab, Batavia, IL 60510 USA. Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. Univ Pittsburgh, Pittsburgh, PA 15260 USA. RP Zimmermann, S (reprint author), Fermilab Natl Accelerator Lab, POB 500, Batavia, IL 60510 USA. NR 15 TC 4 Z9 4 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 JUN PY 2001 VL 48 IS 3 BP 504 EP 508 DI 10.1109/23.940107 PG 5 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA 465EG UT WOS:000170576200052 ER PT J AU Landgraf, JM Adler, C LeVine, MJ Ljubicic, A Nelson, JM Schulz, MW Lange, JS AF Landgraf, JM Adler, C LeVine, MJ Ljubicic, A Nelson, JM Schulz, MW Lange, JS TI The implementation of the STAR data-acquisition system using a Myrinet Network SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT Annual Nuclear Science Symposium (NSS) CY OCT 15-20, 2000 CL LYON, FRANCE SP IEEE, CEA, IN2P3, CERN DE computer network performance; computer networks; nuclear physics; SCADA systems ID DAQ AB We will present results from the first year of operation of the STAR data-acquisition (DAQ) system using a Myrinet Network. STAR is one of four experiments to have been commissioned at the Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory during 1999 and 2000. The DAQ system is fully integrated with a Level 3 Trigger. The combined system currently consists of 33 Myrinet Nodes, which run in a mixed environment of MVME processors running VxWorks, DEC Alpha workstations running Linux, and SUN Solaris machines. The network will eventually contain up to 150 nodes for the expected final size of the L3 processor farm. Myrinet is a switched high-speed low-latency network produced by Myricom and available for PCI and PMC on a wide variety of platforms. The STAR DAQ system uses the Myrinet network for messaging, L3 processing, and event building. After the events are built, they are sent via gigabit ethernet to the RHIC computing facility and stored to tape using HPSS. The combined DAQ/L3 system processes 160-MB events at 100 Hz, compresses each event to 20 NIB, and performs tracking on the events to implement a physics-based filter to reduce the data storage rate to 20 MB/s. C1 Brookhaven Natl Lab, Upton, NY 11973 USA. Univ Frankfurt, D-60486 Frankfurt, Germany. Univ Birmingham, Birmingham B15 2TT, W Midlands, England. RP Landgraf, JM (reprint author), Brookhaven Natl Lab, Upton, NY 11973 USA. NR 9 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 JUN PY 2001 VL 48 IS 3 BP 601 EP 606 DI 10.1109/23.940126 PG 6 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA 465EG UT WOS:000170576200071 ER PT J AU Moses, WW Young, JW Baker, K Jones, W Lenox, M Ho, MH Weng, M AF Moses, WW Young, JW Baker, K Jones, W Lenox, M Ho, MH Weng, M TI The electronics system for the LBNL positron emission mammography (PEM) camera SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT Medical Imaging Conference (MIC) CY OCT 15-20, 2000 CL LYON, FRANCE ID DETECTOR AB We describe the electronics for a high-performance positron emission mammography (PEM) camera. It is based on the electronics for a human brain positron emission tomography (PET) camera (the Siemens/CTI HRRT), modified to use a detector module that incorporates a photodiode (PD) array. An application-specified integrated circuit (ASIC) services the photodetector (PD) array, amplifying its signal and identifying the crystal of interaction. Another ASIC services the photomultiplier tube (PMT), measuring its output and providing a timing signal. Field-programmable gate arrays (FPGAs) and lookup RAMs are used to apply crystal-by-crystal correction factors and measure the energy deposit and the interaction depth (based on the PD/PMT ratio). Additional FPGAs provide event multiplexing, derandomization. coincidence detection. and real-time rebinning. Embedded PC/104 microprocessors provide communication, real-time control, and configure the system. Extensive use of FPGAs make the overall design extremely flexible, allowing many different functions (or design modifications) to be realized without hardware changes. Incorporation of extensive onboard diagnostics, implemented in the FPGAs, is required by the very high level of integration and density achieved by this system. C1 Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. CTI PET Syst, Knoxville, TN 37932 USA. RP Moses, WW (reprint author), Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. NR 10 TC 11 Z9 11 U1 0 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 JUN PY 2001 VL 48 IS 3 BP 632 EP 636 DI 10.1109/23.940138 PN 2 PG 5 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA 465EH UT WOS:000170576300004 ER PT J AU Tornai, MP Archer, CN Weisenberger, AG Wojcik, R Popov, V Majewski, S Keppel, CE Levin, CS Tipnis, SV Nagarkar, VV AF Tornai, MP Archer, CN Weisenberger, AG Wojcik, R Popov, V Majewski, S Keppel, CE Levin, CS Tipnis, SV Nagarkar, VV TI Investigation of microcolumnar scintillators on an optical fiber coupled compact imaging system SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT Medical Imaging Conference (MIC) CY OCT 15-20, 2000 CL LYON, FRANCE DE beta-ray detectors; biomedical nuclear imaging; nuclear imaging; optical fiber coupling; optical fibers; positrons; positron sensitive particle detectors; scintillation detectors ID BETA; DETECTOR; CAMERA; PROBES AB A compact imaging system with a novel front-end detector is under investigation and development. Unique aspects of this collimatorless system include the use of thin arrays of many thousands of microcolumnar (< 10 mum diameter) CsI front-end scintillators that are coupled through a four-times reducing fiber-optic (FO) bundle to a metal-channel multianode position sensitive photodetector. The tested arrays are 140 or 200 pm tall on faceplates of plane glass, FO, and FO with statistical extramural absorbers (EMAs). The highly discrete nature of the scintillator microcolumn arrays ensures very fine intrinsic spatial resolution, limited by the particle penetration and backscatter in the detector assembly. Their retro-reflector-tipped front ends facilitate light propagation toward the photodetector, ensuring good light collection. Monte Carlo simulations confirmed the limiting nature of beta particle penetration on measurable resolution. With this system, absolute light output was higher for the taller arrays, which indicates that these sizes are below the optimum for light output and energy absorption from the energetic beta particles; even taller scintillators, however, would suffer from increased backgrounds from annihilation radiation with positron detection. While MTF measurements with an X-ray source and microslit indicate the best response with the arrays on FO + EMA substrates, measurements with high and medium (1.7 MeV and 635 keV) energy beta line sources yield the best responses with the plane glass substrate, indicating that energy thresholding affects resolution in the classical way, even with these highly miniaturized arrays. Experiments with complex positron emission distributions along with large gamma-ray backgrounds, as may be expected during surgery, yield images with small background contamination and no distortions. C1 Duke Univ, Med Ctr, Dept Radiol, Nucl Med Sect, Durham, NC 27710 USA. Duke Univ, Dept Biomed Engn, Durham, NC 27710 USA. Thomas Jefferson Natl Accelarator Facil, Detector Grp, Newport News, VA 23606 USA. Thomas Jefferson Natl Accelarator Facil, Div Phys, Newport News, VA 23606 USA. Hampton Univ, Dept Nucl & High Energy Phys, Hampton, VA 23668 USA. Univ Calif San Diego, Dept Radiol, San Diego, CA 92161 USA. VA Med Ctr, San Diego, CA 92161 USA. Radiat Monitoring Devices Inc, Watertown, MA 02172 USA. RP Tornai, MP (reprint author), Duke Univ, Med Ctr, Dept Radiol, Nucl Med Sect, Durham, NC 27710 USA. NR 21 TC 11 Z9 11 U1 0 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD JUN PY 2001 VL 48 IS 3 BP 637 EP 644 DI 10.1109/23.940139 PN 2 PG 8 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA 465EH UT WOS:000170576300005 ER PT J AU Vaska, P Petrillo, MJ Muehllehner, G AF Vaska, P Petrillo, MJ Muehllehner, G TI Virtual PMTs: Improving centroid positioning performance near the edges of a gamma camera detector SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT Medical Imaging Conference (MIC) CY OCT 15-20, 2000 CL LYON, FRANCE DE data acquisition; position measurement; positron emission tomography (PET); scintillation detectors; single-photon emission computed tomography (SPECT) AB The radiation detector used in typical gamma cameras and NaI-based positron emission tomography (PET) scanners effectively positions events over most of its crystal area, but the spatial resolution begins to suffer at the edges. One reason is that the measured light distribution is truncated or otherwise asymmetric, and the centroid positioning algorithm no longer optimally weights the photomultiplier tube (PMT) signals in this case. As a result, events less than a certain distance from the edge must be rejected, reducing geometric efficiency and complicating image reconstruction for PET systems with multiple fixed detectors. Short of discarding the centroid algorithm altogether, a computationally simple way to improve the positioning is to define a strip of physically nonexistent, or virtual, PMTs around the actual PMTs and to assign realistic signal values to them event by event based on the signals of nearby real PMTs. If the centroid algorithm now also includes the virtual PMTs, improved spatial resolution is obtained due to better weighting of the PMT signals. With minimal modification to the detector, the virtual PMT method was implemented and tested on an ADAC UGM C-PET detector and found to significantly improve spatial resolution near the detector edges. C1 ADAC UGM, Philadelphia, PA 19104 USA. ADAC Labs, Milpitas, CA 95035 USA. RP Vaska, P (reprint author), Brookhaven Natl Lab, Dept Med, Upton, NY 11973 USA. NR 6 TC 3 Z9 3 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 JUN PY 2001 VL 48 IS 3 BP 645 EP 649 DI 10.1109/23.940140 PN 2 PG 5 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA 465EH UT WOS:000170576300006 ER PT J AU Huber, JS Moses, WW Andreaco, MS Petterson, O AF Huber, JS Moses, WW Andreaco, MS Petterson, O TI An LSO scintillator array for a PET detector module with depth of interaction measurement SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT Medical Imaging Conference (MIC) CY OCT 15-20, 2000 CL LYON, FRANCE ID HIGH-RESOLUTION; LIGHT COLLECTION; SMALL ANIMALS; CAMERA; CRYSTALS; DESIGN AB We present construction methods and performance results for a production scintillator array of 64 optically isolated, 3 mm x 3 mm x 30 mm sized LSO crystals. This scintillator array has been developed for a PET detector module consisting of the 8 x 8 LSO array coupled on one end to a single photomultiplier tube (PMT) and on the opposite end to a 64 pixel array of silicon photodiodes (PD). The PMT provides an accurate timing pulse and initial energy discrimination, the PD identifies the crystal of interaction, the sum provides a total energy signal, and the PD/(PD + PMT) ratio determines the depth of interaction (DOI). Unlike the previous LSO array prototypes, we now glue Lumirror reflector material directly onto 4 sides of each crystal to obtain an easily manufactured, mechanically rugged array with our desired depth dependence. With 511 keV excitation, we obtain a total energy signal of 3600 electrons, pulse-height resolution of 25% FWHM, and 6-15 mm FWHM DOI resolution. C1 Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. RP Huber, JS (reprint author), Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. NR 16 TC 51 Z9 51 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 JUN PY 2001 VL 48 IS 3 BP 684 EP 688 DI 10.1109/23.940147 PN 2 PG 5 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA 465EH UT WOS:000170576300013 ER PT J AU Feng, B Veress, AI Sitek, A Gullberg, GT Roy, DG AF Feng, B Veress, AI Sitek, A Gullberg, GT Roy, DG TI Estimation of mechanical properties from gated SPECT and Cine MRI data using a finite-element mechanical model of the left ventricle SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT Medical Imaging Conference (MIC) CY OCT 15-20, 2000 CL LYON, FRANCE DE Cine MRI; finite element; gated cardiac SPECT; left ventricle mechanical model; myocardial mechanical properties ID LARGE ELASTIC DEFORMATIONS; CONSTITUTIVE RELATIONS; ACTIVE CONTRACTION; CARDIAC-MUSCLE; MYOCARDIUM; STRESS; HEART AB A significant challenge in diagnosing cardiac disease is determining the viability of myocardial tissue when evaluating the prognosis of vascular bypass surgery. A finite-element mechanical model of the left ventricular myocardium was developed to evaluate mechanical properties of the myocardium, which is an important indicator of viable myocardial tissue and of several aspects of congestive heart failure. The model of the heart muscle mechanics was derived from the passive and active behavior of skeletal muscle, which is considered to be a quasi-incompressible transversely isotropic hyperelastic material of a specified helical fiber structure configuration. Contraction of the myocardium was replicated by simulating active contractions along the helical fibers, then solving (quasi-statically) for the associated boundary valued problem at a sequence of time steps between end-diastole and end-systole of the cardiac cycle. At each time step, the finite-element software package ABAQUS was used to determine the deformation of the left ventricle, which was loaded by intraventricular pressure. An ellipsoidal and a cylindrical model of the left ventricle were developed under both passive loading and active contraction. Parameters that describe the material properties of the myocardium were estimated for the cylindrical model by fitting the radial motion described by the model to gated SPECT and eine MRI data. We found that the estimation was sensitive to the measurement of the motion. Results from the finite-element analysis were compared to those from a purely mathematical description of the cylindrical model. C1 Univ Utah, Med Imaging Res Lab, Salt Lake City, UT 84108 USA. Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. USN, Res Lab, Landover, MD 20785 USA. RP Feng, B (reprint author), Univ Utah, Med Imaging Res Lab, Salt Lake City, UT 84108 USA. OI Sitek, Arkadiusz/0000-0002-0677-4002 NR 31 TC 4 Z9 4 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 JUN PY 2001 VL 48 IS 3 BP 725 EP 733 DI 10.1109/23.940154 PN 2 PG 9 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA 465EH UT WOS:000170576300020 ER PT J AU Klein, GJ Reutter, BW Huesman, RH AF Klein, GJ Reutter, BW Huesman, RH TI Four-dimensional affine registration models for respiratory-gated PET SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT Medical Imaging Conference (MIC) CY OCT 15-20, 2000 CL LYON, FRANCE DE image registration; motion compensation; positron emission tomography (PET) ID LEFT-VENTRICULAR FUNCTION; RESOLUTION; MOTION; HEART AB The heart position shifts considerably due to motion associated with the respiratory cycle, and this motion can degrade the image quality of cardiac-gated positron emission tomography (PET) studies. One method to combat this motion-induced blur is a respiratory-gated acquisition followed by recombination of registered image volumes using a rigid-body motion assumption; however, nonrigid deformation of the heart from respiratory motion may reduce the effectiveness of this procedure. We have investigated a 12-parameter global affine motion model for registration of different respiratory gates in an end-diastolic cardiac PET sequence. To obtain robust estimates of motion, a four-dimensional registration model was devised that encouraged smoothly varying motion between adjacent respiratory time frames. Registration parameters were iteratively calculated using a cost function that combined a least squares voxel difference measure with a penalty obtained from a prediction prior. The prior was calculated from adjacent time frames assuming constant velocity and an affine model. After registration, the principal extension ratios were calculated to measure the degree of nonrigid motion. In data from ten subjects, extension ratios of over 5% were common, indicating that an affine model may provide better registrations and in turn, better motion-corrected composite volumes than could a technique restricted to the six-parameter rigid body assumption. C1 Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Ctr Funct Imaging, Berkeley, CA 94720 USA. RP Klein, GJ (reprint author), Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Ctr Funct Imaging, Berkeley, CA 94720 USA. NR 11 TC 44 Z9 44 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 JUN PY 2001 VL 48 IS 3 BP 756 EP 760 DI 10.1109/23.940159 PN 2 PG 5 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA 465EH UT WOS:000170576300025 ER PT J AU Majewski, S Kieper, D Curran, E Keppel, C Kross, B Palumbo, A Popov, V Weisenberger, AG Welch, B Wojcik, R Williams, MB Goode, AR More, M Zhang, G AF Majewski, S Kieper, D Curran, E Keppel, C Kross, B Palumbo, A Popov, V Weisenberger, AG Welch, B Wojcik, R Williams, MB Goode, AR More, M Zhang, G TI Optimization of dedicated scintimammography procedure using detector prototypes and compressible phantoms SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT Medical Imaging Conference (MIC) CY OCT 15-20, 2000 CL LYON, FRANCE DE pixellated scintillator; position-sensitive photo-multipliers; scintimammography ID SUSPECTED BREAST-CANCER; TC-99M-MIBI SCINTIMAMMOGRAPHY; SCINTILLATION CAMERA; TECHNETIUM-99M-SESTAMIBI; TUMOR; SPECT AB Results are presented on the optimization of the design and use of dedicated compact scintimammography gamma cameras. Prototype imagers with a field of view (FOV) of 5 x 5 cm(2), 10 x 10 cm(2), and 15 x 20 cm(2) were used in either a dual modality mode as an adjunct technique to digital X-ray mammography imagers or as stand-alone instruments such as dedicated breast SPECT and planar imagers. Experimental data were acquired to select the best imaging modality (SPECT or planar) to detect small lesions using Tc-99m radio-labeled pharmaceuticals. In addition, studies were performed to optimize the imaging geometry. Results suggest that the preferred imaging geometry is planar imaging with two opposing detector heads while the breast is under compression. However, further study of the dedicated breast SPECT is warranted. C1 Thomas Jefferson Natl Accelerator Facil, Newport News, VA 23606 USA. New Horizons Governors Sch Sci & Technol, Hampton, VA 23666 USA. Hampton Univ, Dept Phys, Hampton, VA 23668 USA. Univ Virginia, Dept Radiol, Charlottesville, VA 22908 USA. RP Majewski, S (reprint author), Thomas Jefferson Natl Accelerator Facil, Newport News, VA 23606 USA. NR 24 TC 57 Z9 57 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 JUN PY 2001 VL 48 IS 3 BP 822 EP 829 DI 10.1109/23.940170 PN 2 PG 8 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA 465EH UT WOS:000170576300036 ER PT J AU Raylman, RR Majewski, S Wojcik, R Weisenberger, AG Kross, B Popov, V AF Raylman, RR Majewski, S Wojcik, R Weisenberger, AG Kross, B Popov, V TI Corrections for the effects of accidental coincidences, Compton scatter, and object size in positron emission mammography (PEM) imaging SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article ID PALPABLE BREAST MASSES; SCINTIMAMMOGRAPHY; CANCER; PHANTOM; SPECT; MODEL; TECHNETIUM-99M-SESTAMIBI; TC-99M-SESTAMIBI; CARCINOMA; LESIONS AB Positron emission mammography (PEM) has begun to show promise as an effective method for the detection of breast lesions. Due to its utilization of tumor-avid radiopharmaceuticals labeled with positron-emitting radionuclides, this technique may be especially useful in imaging of women with radiodense or fibrocystic breasts. While the use of these radiotracers affords PEM unique capabilities, it also introduces some limitations. Specifically, acceptance of accidental and Compton-scattered coincidence events can decrease lesion detectability. We studied the effect of accidental coincidence events on PEM images produced by the presence of F-18-Fluorodeoxyglucose in the organs of a subject using an anthropomorphic phantom. A delayed-coincidence technique was tested as a method for correcting PEM images for the occurrence of accidental events. Also, a Compton scatter correction algorithm designed specifically for PEM was developed and tested using a compressed breast phantom. Finally, the effect of object size on image counts and a correction for this effect were explored. The imager used in this study consisted of two PEM detector heads mounted 20 cm apart on a Lorad biopsy apparatus. The results demonstrated that a majority of the accidental coincidence events (similar to 80%) detected by this system were produced by radiotracer uptake in the adipose and muscle tissue of the torso. The presence of accidental coincidence events was shown to reduce lesion detectability. Much of this effect was eliminated by correction of the images utilizing estimates of accidental-coincidence contamination acquired with delayed coincidence circuitry built into the PEM system. The Compton scatter fraction for this system was similar to 14%. Utilization of a new scatter correction algorithm reduced the scatter fraction to similar to1.5%. Finally, reduction of count recovery due to object size was measured and a correction to the data applied. Application of correction techniques for accidental coincidences, Compton scatter, and count loss due to image size increased target-to-background contrast ratios to approximately the maximum level theoretically achievable with this PEM system. C1 W Virginia Univ, Dept Radiol, Ctr Adv Imaging, Morgantown, WV 26506 USA. Jefferson Lab, Detector Grp, Newport News, VA 23606 USA. RP Raylman, RR (reprint author), W Virginia Univ, Dept Radiol, Ctr Adv Imaging, Morgantown, WV 26506 USA. NR 35 TC 10 Z9 10 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 JUN PY 2001 VL 48 IS 3 BP 913 EP 923 DI 10.1109/23.940132 PN 3 PG 11 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA 465EJ UT WOS:000170576400004 ER PT J AU Demaine, ED Foster, I Kesselman, C Snir, M AF Demaine, ED Foster, I Kesselman, C Snir, M TI Generalized communicators in the message passing interface SO IEEE TRANSACTIONS ON PARALLEL AND DISTRIBUTED SYSTEMS LA English DT Article DE MPI; process spawning; multithreading; process names AB We propose extensions to the Message Passing Interface (MPI) that generalize the MPI communicator concept to allow multiple communication endpoints per process, dynamic creation of endpoints, and the transfer of endpoints between processes. The generalized communicator construct can be used to express a wide range of interesting communication structures, including collective communication operations involving multiple threads per process, communications between dynamically created threads or processes, and object-oriented applications in which communications are directed to specific objects. Furthermore, this enriched functionality can be provided in a manner that preserves backward compatibility with MPI. We describe the proposed extensions, illustrate their use with examples, and describe a prototype implementation in the popular MPI implementation MPICH. C1 Univ Waterloo, Dept Comp Sci, Waterloo, ON N2L 3G1, Canada. Argonne Natl Lab, Div Math & Comp Sci, Argonne, IL 60439 USA. Univ Chicago, Chicago, IL 60637 USA. Univ So Calif, Inst Informat Sci, Marina Del Rey, CA 90292 USA. IBM Corp, Thomas J Watson Res Ctr, Yorktown Heights, NY 10598 USA. RP Demaine, ED (reprint author), Univ Waterloo, Dept Comp Sci, Waterloo, ON N2L 3G1, Canada. RI Snir, Marc/B-1050-2009; OI Snir, Marc/0000-0002-3504-2468; Kesselman, Carl/0000-0003-0917-1562 NR 14 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 1045-9219 J9 IEEE T PARALL DISTR JI IEEE Trans. Parallel Distrib. Syst. PD JUN PY 2001 VL 12 IS 6 BP 610 EP 616 DI 10.1109/71.932714 PG 7 WC Computer Science, Theory & Methods; Engineering, Electrical & Electronic SC Computer Science; Engineering GA 444KJ UT WOS:000169398400007 ER PT J AU Babich, LP Donskoy, EN Kutsyk, IM Kudryavtsev, AY Roussel-Dupre, RA Shamraev, BN Symbalisty, EMD AF Babich, LP Donskoy, EN Kutsyk, IM Kudryavtsev, AY Roussel-Dupre, RA Shamraev, BN Symbalisty, EMD TI Comparison of relativistic runaway electron avalanche rates obtained from Monte Carlo simulations and kinetic equation solution SO IEEE TRANSACTIONS ON PLASMA SCIENCE LA English DT Article DE avalanche; kinetic equation; Monte Carlo; runaway electrons ID AIR BREAKDOWN; THUNDERSTORM AB New computer simulations of the relativistic runaway electron avalanche mechanism were carried out to remove prior approximations and reassess the space and temporal scales predicted by previous Boltzmann calculations. Two Monte Carlo techniques, a finite-difference solution, and a finite-volume solution of the kinetic equation for high-energy electrons were employed. Results obtained for the length and time scales at sufficiently high electric fields by the different methods are consistent with each other and with analytical estimates. The physical reason for the remaining discrepancy at small fields is discussed. C1 VNIIEF, Russian Fed Nucl Ctr, Sarov 607190, Russia. Univ Calif Los Alamos Natl Lab, Div Earth & Environm Sci, Los Alamos, NM 87545 USA. RP Babich, LP (reprint author), VNIIEF, Russian Fed Nucl Ctr, Sarov 607190, Russia. NR 22 TC 31 Z9 31 U1 1 U2 2 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0093-3813 J9 IEEE T PLASMA SCI JI IEEE Trans. Plasma Sci. PD JUN PY 2001 VL 29 IS 3 BP 430 EP 438 DI 10.1109/27.928940 PG 9 WC Physics, Fluids & Plasmas SC Physics GA 444KM UT WOS:000169398700004 ER PT J AU Dixon, WE Dawson, DM Zergeroglu, E Behal, A AF Dixon, WE Dawson, DM Zergeroglu, E Behal, A TI Adaptive tracking control of a wheeled mobile robot via an uncalibrated camera system SO IEEE TRANSACTIONS ON SYSTEMS MAN AND CYBERNETICS PART B-CYBERNETICS LA English DT Article DE adaptive control; visual-servoing; wheeled mobile robot ID VISION AB This paper considers the problem of position/orientation tracking control of wheeled mobile robots via visual servoing in the presence of parametric uncertainty associated with the mechanical dynamics and the camera system. Specifically, we design an adaptive controller that compensates for uncertain camera and mechanical parameters and ensures global asymptotic position/orientation tracking. Simulation and experimental results are included to illustrate the performance of the control law. C1 Oak Ridge Natl Lab, Robot & Proc Syst Div, Oak Ridge, TN 37831 USA. Clemson Univ, Dept Elect & Comp Engn, Clemson, SC 29634 USA. RP Oak Ridge Natl Lab, Robot & Proc Syst Div, Oak Ridge, TN 37831 USA. EM dixonwe@ornl.gov RI Dixon, Warren/F-5238-2015 OI Dixon, Warren/0000-0002-5091-181X NR 24 TC 57 Z9 70 U1 1 U2 7 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855-4141 USA SN 1083-4419 EI 1941-0492 J9 IEEE T SYST MAN CY B JI IEEE Trans. Syst. Man Cybern. Part B-Cybern. PD JUN PY 2001 VL 31 IS 3 BP 341 EP 352 DI 10.1109/3477.931519 PG 12 WC Automation & Control Systems; Computer Science, Artificial Intelligence; Computer Science, Cybernetics SC Automation & Control Systems; Computer Science GA 447XM UT WOS:000169597800006 PM 18244797 ER PT J AU Raber, E Jin, A Noonan, K McGuire, R Kirvel, RD AF Raber, E Jin, A Noonan, K McGuire, R Kirvel, RD TI Decontamination issues for chemical and biological warfare agents: how clean is clean enough? SO INTERNATIONAL JOURNAL OF ENVIRONMENTAL HEALTH RESEARCH LA English DT Article DE biological toxin; biological warfare agent; chemical warfare agent; contamination; decontamination ID ANTHRAX; HEALTH AB The objective of this assessment is to determine what level of cleanup will be required to meet regulatory and stakeholder needs in the case of a chemical and/or biological incident at a civilian facility. A literature review for selected, potential chemical and biological warfare agents shows that dose information is often lacking or controversial. Environmental regulatory limits or other industrial health guidelines that could be used to help establish cleanup concentration levels for such agents are generally unavailable or not applicable for a public setting. Although dose information, cleanup criteria, and decontamination protocols all present challenges to effective planning, several decontamination approaches are available. Such approaches should be combined with risk-informed decision making to establish reasonable cleanup goals for protecting health, property, and resources. Key issues during a risk assessment are to determine exactly what constitutes a safety hazard and whether decontamination is necessary or not for a particular scenario. An important conclusion is that cleanup criteria are site dependent and stakeholder specific. The results of a modeling exercise for two outdoor scenarios are presented to reinforce this conclusion. Public perception of risk to health, public acceptance of recommendations based on scientific criteria, political support, time constraints, and economic concerns must all be addressed in the context of a specific scenario to yield effective and acceptable decontamination. C1 Univ Calif Lawrence Livermore Natl Lab, Environm Protect Dept, Livermore, CA 94550 USA. RP Raber, E (reprint author), Univ Calif Lawrence Livermore Natl Lab, Environm Protect Dept, POB 808,L-626, Livermore, CA 94550 USA. NR 44 TC 40 Z9 41 U1 1 U2 11 PU CARFAX PUBLISHING PI BASINGSTOKE PA RANKINE RD, BASINGSTOKE RG24 8PR, HANTS, ENGLAND SN 0960-3123 J9 INT J ENVIRON HEAL R JI Int. J. Environ. Health Res. PD JUN PY 2001 VL 11 IS 2 BP 128 EP 148 PG 21 WC Environmental Sciences; Public, Environmental & Occupational Health SC Environmental Sciences & Ecology; Public, Environmental & Occupational Health GA 433EE UT WOS:000168741700002 PM 11382346 ER PT J AU Driessen, BJ Dohner, JL AF Driessen, BJ Dohner, JL TI A finite element-boundary element method for advection-diffusion problems with variable advective fields and infinite domains SO INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER LA English DT Article DE advection-diffusion; infinite space; finite elements; boundary elements ID NUMERICAL-SOLUTION; EQUATIONS; FORMULATION AB In this paper a hybrid, finite element-boundary element method which can be used to solve for particle advection-diffusion in infinite domains with variable advective fields is presented. In previous work either boundary element, finite element, or difference methods were used to solve for particle motion in advective-diffusive domains. These methods have a number of limitations. Due to the complexity of computing spatially dependent Green's functions, the boundary element method is limited to domains containing only constant advective fields, and due to their inherent formulations, finite element and finite difference methods are limited to only domains of finite spatial extent. Thus, finite element and finite difference methods are limited to finite space problems for which the boundary element method is not, and the boundary element method is limited to constant advection field problems for which finite element and finite difference methods are not. In this paper it is proposed to split the total domain into two sub-domains, and for each of these sub-domains, apply the appropriate solution method; thereby, producing a method for the total infinite space, variable advective field domain. (C) 2001 Elsevier Science Ltd. All rights reserved. C1 Sandia Natl Labs, Struct Dynam & Controls, Albuquerque, NM 87185 USA. RP Driessen, BJ (reprint author), Sandia Natl Labs, Struct Dynam & Controls, POB 5800,MS 0847, Albuquerque, NM 87185 USA. NR 10 TC 5 Z9 5 U1 0 U2 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0017-9310 J9 INT J HEAT MASS TRAN JI Int. J. Heat Mass Transf. PD JUN PY 2001 VL 44 IS 11 BP 2183 EP 2191 DI 10.1016/S0017-9310(00)00226-X PG 9 WC Thermodynamics; Engineering, Mechanical; Mechanics SC Thermodynamics; Engineering; Mechanics GA 425LQ UT WOS:000168292400016 ER PT J AU Skjellum, A Dimitrov, R Angaluri, SV Lifka, D Coulouris, G Uthayopas, P Scott, SL Eskicioglu, R AF Skjellum, A Dimitrov, R Angaluri, SV Lifka, D Coulouris, G Uthayopas, P Scott, SL Eskicioglu, R TI Systems administration SO INTERNATIONAL JOURNAL OF HIGH PERFORMANCE COMPUTING APPLICATIONS LA English DT Article C1 Mississippi State Univ, Mississippi State, MS 39762 USA. Cornell Theory Ctr, Ithaca, NY USA. Kasetsart Univ, Bangkok, Thailand. Oak Ridge Natl Lab, Div Math & Comp Sci, Distributed Comp Res Grp, Oak Ridge, TN USA. Univ Manitoba, Winnipeg, MB R3T 2N2, Canada. NR 8 TC 0 Z9 0 U1 0 U2 0 PU SAGE PUBLICATIONS INC PI THOUSAND OAKS PA 2455 TELLER RD, THOUSAND OAKS, CA 91320 USA SN 1094-3420 J9 INT J HIGH PERFORM C JI Int. J. High Perform. Comput. Appl. PD SUM PY 2001 VL 15 IS 2 SI SI BP 143 EP 161 DI 10.1177/109434200101500207 PG 19 WC Computer Science, Hardware & Architecture; Computer Science, Interdisciplinary Applications; Computer Science, Theory & Methods SC Computer Science GA 424HE UT WOS:000168226200007 ER PT J AU Dongarra, J Moore, S Trefethen, A AF Dongarra, J Moore, S Trefethen, A TI Numerical libraries and tools for scalable parallel cluster computing SO INTERNATIONAL JOURNAL OF HIGH PERFORMANCE COMPUTING APPLICATIONS LA English DT Article C1 Univ Tennessee, Dept Comp Sci, Knoxville, TN 37996 USA. Oak Ridge Natl Lab, Div Math & Comp Sci, Oak Ridge, TN USA. Rice Univ, Houston, TX 77251 USA. Numer Algorithms Grp, Oxford, England. RP Dongarra, J (reprint author), Univ Tennessee, Dept Comp Sci, Knoxville, TN 37996 USA. NR 20 TC 1 Z9 1 U1 0 U2 0 PU SAGE PUBLICATIONS INC PI THOUSAND OAKS PA 2455 TELLER RD, THOUSAND OAKS, CA 91320 USA SN 1094-3420 J9 INT J HIGH PERFORM C JI Int. J. High Perform. Comput. Appl. PD SUM PY 2001 VL 15 IS 2 SI SI BP 175 EP 180 DI 10.1177/109434200101500210 PG 6 WC Computer Science, Hardware & Architecture; Computer Science, Interdisciplinary Applications; Computer Science, Theory & Methods SC Computer Science GA 424HE UT WOS:000168226200010 ER PT J AU Massoudi, M Boyle, EJ AF Massoudi, M Boyle, EJ TI A continuum-kinetic theory approach to the rapid flow of granular materials: the effects of volume fraction gradient SO INTERNATIONAL JOURNAL OF NON-LINEAR MECHANICS LA English DT Article DE granular materials; constitutive relations; continuum/kinetic theories; inclined plane ID STEADY SHEAR-FLOW; CONSTITUTIVE RELATIONS; INELASTIC SPHERES; INCLINED PLANE; DENSE GAS; SMOOTH; EQUATIONS; MECHANICS; GRAVITY; MODEL AB We study the fully developed flow of granular materials down an inclined plane. The model uses ideas from both continuum and kinetic theories, where the form of the constitutive relation for the stress tensor is derived using standard techniques in continuum mechanics (cf. Rajagopal and Massoudi, DOE Report, DOE/PETC/TR-90/3, 1990); the material properties are derived using the kinetic theory approximation proposed by Boyle and Massoudi (Int. J. Eng. Sci. 28 (1990) 1261-1275), which includes the effects of the gradient of the volume fraction. The equations are nondimensionalized and the system of non-linear ordinary differential equations is solved numerically. Published by Elsevier Science Ltd. C1 US Dept Energy, Natl Energy Technol Lab, Pittsburgh, PA 15236 USA. US Dept Energy, Natl Energy Technol Lab, Morgantown, WV 26505 USA. RP Massoudi, M (reprint author), US Dept Energy, Natl Energy Technol Lab, POB 10940, Pittsburgh, PA 15236 USA. NR 55 TC 17 Z9 17 U1 1 U2 5 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0020-7462 J9 INT J NONLINEAR MECH JI Int. J. Non-Linear Mech. PD JUN PY 2001 VL 36 IS 4 BP 637 EP 648 DI 10.1016/S0020-7462(00)00027-5 PG 12 WC Mechanics SC Mechanics GA 406PP UT WOS:000167224600007 ER PT J AU Kennedy, TF Connery, J AF Kennedy, TF Connery, J TI Barley yellow dwarf virus in winter barley in Ireland: yield loss and timing of autumn aphicides in controlling the MAV-strain SO IRISH JOURNAL OF AGRICULTURAL AND FOOD RESEARCH LA English DT Article DE aphids; aphicide; barley yellow dwarf virus; winter barley; yield loss ID CEREAL APHIDS; RHOPALOSIPHUM-PADI; NORTHERN ENGLAND; WESTERN FRANCE; EPIDEMIOLOGY; VECTORS; AVENAE AB The timing of aphicide application to control barley yellow dwarf virus (BYDV) in autumn-sown barley, at Oak Park in 1988, 1989 and 1995, was investigated. September-sown crops had higher aphid infestations and BYDV infections relative to October-sown crops. In general, Sitobion avenae was the more abundant species of aphid encountered, while the MAV-strain of the disease, which is specifically transmitted by S. avenae, was the only serotype of the virus found in these trials. The rose-grain aphid, Metopolophium dirhodum, which can also transmit the MAV-type of BYDV, was common only in 1989/90. The application of aphicides prevented yield losses, due to virus, of 2.2 to 3.4 t/ha for barley sown in early-September, 2.2 to 3.2 t/ha for late-September, 1.3 t/ha for mid-October and 0.65 t/ha for late-October sown crops. The largest yield response (56%) for a single aphicide application was from a treatment in the first week in November. Results indicated that early September-sown crops should receive two aphicides, one in mid-October and the second in early-November. Crops sown in late September and October should receive only one aphicide (during the first week in November). There was no advantage in applying additional aphicides throughout the winter and early spring, even in a season when aphids and virus were plentiful. However, applying an aphicide in either December, January or February, to plots that had not received an earlier autumn aphicide treatment did prevent yield losses of 2.4 t/ha, 1.9 t/ha and 1.4 t/ha, respectively. C1 TEAGASC, Oak Pk Res Ctr, Carlow, Ireland. RP Kennedy, TF (reprint author), TEAGASC, Oak Pk Res Ctr, Carlow, Ireland. NR 50 TC 5 Z9 5 U1 2 U2 5 PU TEAGASC PI DUBLIN PA 19 SANDYMOUNT AVE, DUBLIN 4, IRELAND SN 0791-6833 J9 IRISH J AGR FOOD RES JI Irish J. Agr. Food Res. PD JUN PY 2001 VL 40 IS 1 BP 55 EP 70 PG 16 WC Agriculture, Multidisciplinary; Food Science & Technology SC Agriculture; Food Science & Technology GA 448EJ UT WOS:000169613700006 ER PT J AU Stoica, AD Popovici, M Hubbard, CR AF Stoica, AD Popovici, M Hubbard, CR TI Neutron imaging with bent perfect crystals. I. Imaging conditions SO JOURNAL OF APPLIED CRYSTALLOGRAPHY LA English DT Article ID QUASI-ELASTIC SCATTERING; 3-AXIS SPECTROMETERS; THERMAL-NEUTRONS; SILICON MONOCHROMATOR; HIGH-RESOLUTION; BRAGG OPTICS; DIFFRACTION; OPTIMIZATION; POSITION; LAMELLAE AB Neutron imaging with bent crystals is considered in the linear approximation of neutron optics. A matrix formalism analogous to that of conventional lens optics is developed. Various imaging conditions are discussed in relation to the crystal deformation type and to possible applications in neutron scattering. All focusing conditions known previously are included as particular cases. Arrangements combining high resolution in imaging with high resolution in scattering are examined. The concept of Bragg mirrors as devices for non-dispersive imaging is introduced. The most powerful application appears to be that of Bragg mirrors combined with the time-of-flight method. Imaging with a thick packet of silicon wafers at the spatial resolution of a single thin wafer is demonstrated. C1 Missouri Univ Res Reactor, Columbia, MO 65211 USA. Oak Ridge Natl Lab, Div Met & Ceram, Oak Ridge, TN 37831 USA. RP Stoica, AD (reprint author), Missouri Univ Res Reactor, Columbia, MO 65211 USA. RI Stoica, Alexandru/K-3614-2013 OI Stoica, Alexandru/0000-0001-5118-0134 NR 45 TC 7 Z9 7 U1 0 U2 6 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 JUN PY 2001 VL 34 BP 343 EP 357 DI 10.1107/S0021889801005106 PN 3 PG 15 WC Chemistry, Multidisciplinary; Crystallography SC Chemistry; Crystallography GA 446WY UT WOS:000169538200015 ER PT J AU Radway, JC Wilde, EW Whitaker, MJ Weissman, JC AF Radway, JC Wilde, EW Whitaker, MJ Weissman, JC TI Screening of algal strains for metal removal capabilities SO JOURNAL OF APPLIED PHYCOLOGY LA English DT Article DE aluminum; bioremoval; blue-green alga; Cyanidium; green algae; heavy metals; Mastigocladus; mercury; Scenedesmus; thermophiles; water pollution; zinc ID BIOSORPTION; TEMPERATURE; MICROALGAE; ALGINATE; PH AB Eight algal species were tested for their ability to remove five toxic metals during 30-min exposures to single-metal (1 mg L-1) solutions at pH 7. Efficacy of metal bioremoval varied according to algal species and metal. Al+3 was best removed by the thermophilic blue-green alga (cyanobacterium) Mastigocladus laminosus, Hg+2 and Zn+2 by the thermophilic and acidophilic red alga Cyanidium caldarium, and Cd+2 by C. caldarium and the green alga Scenedesmus quadricauda. All of these alga/metal combinations resulted in >90% metal removal. However, none of the eight algal species removed more than 10% of Cr+6. Results indicate that some toxic metals are more readily removed than others are by algae and that selection of appropriate strains could potentially enhance bioremoval of specific metals from wastewater at neutral pH. C1 Westinghouse Savannah River Co, Savannah River Lab, Aiken, SC 29808 USA. Microbial Prod Inc, Vero Beach, FL 32968 USA. RP Wilde, EW (reprint author), Westinghouse Savannah River Co, Savannah River Lab, Aiken, SC 29808 USA. NR 17 TC 0 Z9 0 U1 0 U2 1 PU SPRINGER PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0921-8971 J9 J APPL PHYCOL JI J. Appl. Phycol. PD JUN PY 2001 VL 13 IS 3 BP 289 EP 293 PG 5 WC Biotechnology & Applied Microbiology; Marine & Freshwater Biology SC Biotechnology & Applied Microbiology; Marine & Freshwater Biology GA 456AQ UT WOS:000170060300011 ER PT J AU Yan, Y Dhere, RG Jones, KM Al-Jassim, MM AF Yan, Y Dhere, RG Jones, KM Al-Jassim, MM TI Influence of substrate structure on the growth of CdTe thin films SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID CDS/CDTE SOLAR-CELLS; CDS; PERFORMANCE; EFFICIENCY AB We report on a high-resolution transmission electron microscopy and energy-dispersive x-ray spectroscopy study of the microstructure of CdTe thin films epitaxially grown on single-crystal hexagonal CdS and cubic CdTe substrates. We find that the different structures of the substrates do not make a great structural difference on the grown CdTe films; i.e., on both substrates, the grown CdTe films have a cubic structure and high density of planar defects near the interface regions. At the CdTe/CdS interface, interdiffusion occurs, forming CdTe1-xSx and CdS1-xTex alloys. These alloys lead to significantly reduced mismatch at the interface. (C) 2001 American Institute of Physics. C1 Natl Renewable Energy Lab, Golden, CO 80401 USA. RP Yan, Y (reprint author), Natl Renewable Energy Lab, Golden, CO 80401 USA. NR 23 TC 13 Z9 13 U1 0 U2 13 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 JUN 1 PY 2001 VL 89 IS 11 BP 5944 EP 5948 DI 10.1063/1.1367406 PN 1 PG 5 WC Physics, Applied SC Physics GA 440AC UT WOS:000169149900012 ER PT J AU Hochbauer, T Misra, A Nastasi, M Mayer, JW AF Hochbauer, T Misra, A Nastasi, M Mayer, JW TI Investigation of the cut location in hydrogen implantation induced silicon surface layer exfoliation SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID CRYSTALLINE SILICON; SI; DIFFUSION; SPECTRA AB The physical mechanisms of hydrogen induced silicon surface layer exfoliation were investigated using the combination of ion beam analysis, secondary ion mass spectroscopy (SIMS), scanning electron microscopy (SEM), and cross section transmission electron microscopy (XTEM). A [100] oriented silicon wafer was implanted with 175 keV protons to a dose of 5 x 10(16) cm(-2). The implanted wafer was bonded to a silicon oxide capped < 100 > silicon wafer and then heated to an elevated temperature of 600 degreesC to produce exfoliation. The hydrogen-implanted sample was analyzed in the as-implanted state as well as after the cleavage of the silicon wafer. The depth distribution of the implantation damage was monitored by Rutherford backscattering spectrometry (RBS) in channeling condition and XTEM imaging. Elastic recoil detection analysis and SIMS was performed to examine the hydrogen depth distribution. Cross section SEM and RBS channeling was used to measure the thickness of the exfoliated layer after cleavage. A comparison of the results deduced from the methods listed shows conclusively that the cleavage of the silicon wafer takes place above the hydrogen concentration peak near the implantation damage peak, revealing the crucial role of the implantation damage in the crystal in terms of hydrogen induced cleavage of the silicon crystal. The stress and strain field in the proton-implantation induced damage region of the silicon crystal is proposed to explain the observed results. (C) 2001 American Institute of Physics. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Arizona State Univ, Tempe, AZ 85287 USA. RP Hochbauer, T (reprint author), Univ Calif Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. RI Misra, Amit/H-1087-2012 NR 43 TC 50 Z9 51 U1 0 U2 1 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 JUN 1 PY 2001 VL 89 IS 11 BP 5980 EP 5990 PN 1 PG 11 WC Physics, Applied SC Physics GA 440AC UT WOS:000169149900017 ER PT J AU Kazimirov, A Faleev, N Temkin, H Bedzyk, MJ Dmitriev, V Melnik, Y AF Kazimirov, A Faleev, N Temkin, H Bedzyk, MJ Dmitriev, V Melnik, Y TI High-resolution x-ray study of thin GaN film on SiC SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID VAPOR-PHASE EPITAXY; STANDING WAVES; STRUCTURAL-PROPERTIES; POLARITY; SURFACE; SAPPHIRE; ALN AB The x-ray standing wave method (XSW) and high-resolution x-ray diffraction were used to study the structural perfection and polarity of GaN epitaxial thin film grown by hydride vapor phase epitaxy on the Si-face SiC substrate. The x-ray standing wave was generated inside the 300 nm thin film under the condition of Bragg diffraction from the film. Excellent crystalline quality of the GaN film was revealed by both x-ray techniques. The XSW analysis of the angular dependencies of the Ga-K fluorescence yield measured while scanning through the GaN(0002) diffraction peak unambiguously showed the Ga polarity of the film. Correlation between the mosaic structure and the static Debye-Waller factor of the GaN lattice was also studied. (C) 2001 American Institute of Physics. C1 Northwestern Univ, Dept Mat Sci & Engn, Evanston, IL 60208 USA. Northwestern Univ, Mat Res Ctr, Evanston, IL 60208 USA. Texas Tech Univ, Dept Elect Engn, Lubbock, TX 79409 USA. Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. TDI Inc, Gaithersburg, MD 20877 USA. RP Kazimirov, A (reprint author), Cornell Univ, Cornell High Energy Synchrotron Source, Ithaca, NY 14853 USA. RI Bedzyk, Michael/B-7503-2009; Bedzyk, Michael/K-6903-2013 NR 22 TC 20 Z9 20 U1 1 U2 5 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 JUN 1 PY 2001 VL 89 IS 11 BP 6092 EP 6097 DI 10.1063/1.1364644 PN 1 PG 6 WC Physics, Applied SC Physics GA 440AC UT WOS:000169149900034 ER PT J AU Hayes, D AF Hayes, D TI Unsteady compression waves in interferometer windows SO JOURNAL OF APPLIED PHYSICS LA English DT Article AB Optical windows for the velocity interferometer system for any reflector perturb the measurement of specimen/window interface velocity during compression wave experiments. The perturbation is caused by the variation of window index of refraction with density. The correction for shocks and steady waves is the ratio of apparent to actual interface velocity and is called 1 + Delta nu/nu (0) in the literature. We find 1 + Delta nu/nu (0) for unsteady waves also depends only upon interface velocity and not on details of the unsteady compression wave as previously reported. The correction 1 + Delta nu/nu (0) for unsteady waves is the same as for steady waves and shocks only if the index of refraction is linear in density in which case 1 + Delta nu/nu (0) is constant equaling the zero-density intercept of the index of refraction function. Differences in LiF window performance for shocks and for unsteady waves are shown to be small compared with other experimental uncertainties. (C) 2001 American Institute of Physics. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Hayes, D (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. NR 9 TC 32 Z9 33 U1 1 U2 1 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 JUN 1 PY 2001 VL 89 IS 11 BP 6484 EP 6486 DI 10.1063/1.1369409 PN 1 PG 3 WC Physics, Applied SC Physics GA 440AC UT WOS:000169149900097 ER PT J AU Cheng, N Ahn, J Krishnan, KM AF Cheng, N Ahn, J Krishnan, KM TI Epitaxial growth and exchange biasing of PdMn/Fe bilayers grown by ion-beam sputtering SO JOURNAL OF APPLIED PHYSICS LA English DT Article; Proceedings Paper CT 8th Joint MMM/Intermag Conference CY JAN 08-11, 2001 CL SAN ANTONIO, TEXAS SP Motorola Labs, TDK Corp, IBM, Toda Kogyo Corp, EMTEC Magnet GmbH, Quantum, Seagate Res, Sony Corp, Magnequench Technol Ctr, AJA Int Inc, Digital Measurement Syst AB Epitaxial PdMn/Fe bilayer structures, in both a-axis PdMn(100)/Fe(001)/MgO(001) and c-axis PdMn(001)/Fe(001)/MgO(001) orientations, were grown by ion-beam sputtering. The a-axis samples were grown at low temperatures (T < 280 degreesC) while the c-axis films were stabilized at a higher temperature range (T > 300 degreesC). Vibrating sample magnetometry measurements show that the as-grown a-axis samples do not have a measurable exchange bias while c-axis samples have an exchange bias field H-e similar to 33 Oe. However, annealing at 230 degreesC for 40 min results in a measurable exchange (H-e similar to 10 Oe) for a-axis samples due to chemical ordering. The possible cause for the difference of H-e in a-axis and c-axis orientations is also discussed. In addition to the normal structure, inverted structures were obtained epitaxially. The exchange biasing for Fe(001)/PdMn(001)/MgO(001) is as big as 68 Oe. (C) 2001 American Institute of Physics. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. RP Krishnan, KM (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. NR 10 TC 23 Z9 23 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 JUN 1 PY 2001 VL 89 IS 11 BP 6597 EP 6599 DI 10.1063/1.1360677 PN 2 PG 3 WC Physics, Applied SC Physics GA 440AV UT WOS:000169151700007 ER PT J AU Mitchell, JF Ling, CD Millburn, JE Argyriou, DN Berger, A Medarde, M AF Mitchell, JF Ling, CD Millburn, JE Argyriou, DN Berger, A Medarde, M TI Magnetic phase diagram of layered manganites in the highly doped regime SO JOURNAL OF APPLIED PHYSICS LA English DT Article; Proceedings Paper CT 8th Joint MMM/Intermag Conference CY JAN 08-11, 2001 CL SAN ANTONIO, TX SP Motorola Labs, TDK Corp, IBM, Toda Kogyo Corp, EMTEC Magnet GmbH, Quantum, Seagate Res, Sony Corp, Magnequench Technol Ctr, AJA Int Inc, Digital Measurement Syst ID MAGNETORESISTANCE; CHARGE; TRANSITION AB The naturally layered colossal magnetoresistive manganites La2-2xSr1+2xMn2O7 exhibit an extremely varied range of magnetic and electronic behavior over a very narrow composition range between x = 0.3 and x = 0.5. The successful synthesis in our laboratories of compounds with nominally greater than 50% Mn4+ concentration has now allowed the study of this region of the phase diagram. Here we present detailed neutron diffraction measurements of these compounds with doping levels 0.5 < x < 1.0. As predicted by simple theories, the type-A layered antiferromagnetic (AF) structure is found at x similar to 0.5 and the type-G "rocksalt" AF structure at x = 1.0. Between these two extremes is found a C-type structure (ferromagnetic rods parallel to b coupled antiferromagnetically to all neighboring rods) stabilized by orbital ordering of y(2) states. Also in this Mn4+-rich regime is found a region in which no long-range magnetic order is observed. We discuss how semiempirical models can explain the variety of magnetic structures and how structural trends as a function of doping corroborate the unifying notion of a shift from in-plane to axial orbital occupation as the Mn4+ concentration is decreased. (C) 2001 American Institute of Physics. C1 Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. RP Argonne Natl Lab, Div Mat Sci, 9700 S Cass Ave, Argonne, IL 60439 USA. EM mitchell@anl.gov RI Ling, Chris D/B-2228-2009; Berger, Andreas/D-3706-2015 OI Ling, Chris D/0000-0003-2205-3106; Berger, Andreas/0000-0001-5865-6609 NR 17 TC 10 Z9 11 U1 2 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 JUN 1 PY 2001 VL 89 IS 11 BP 6618 EP 6620 DI 10.1063/1.1357135 PN 2 PG 3 WC Physics, Applied SC Physics GA 440AV UT WOS:000169151700013 ER PT J AU Welp, U Berger, A Vlasko-Vlasov, VK You, H Gray, KE Mitchell, JF AF Welp, U Berger, A Vlasko-Vlasov, VK You, H Gray, KE Mitchell, JF TI Effect of layering and doping on the magnetic anisotropy of the layered manganites La2-2xSr1+2xMn2O7 (x=0.3-0.4) SO JOURNAL OF APPLIED PHYSICS LA English DT Article; Proceedings Paper CT 8th Joint MMM/Intermag Conference CY JAN 08-11, 2001 CL SAN ANTONIO, TEXAS SP Motorola Labs, TDK Corp, IBM, Toda Kogyo Corp, EMTEC Magnet GmbH, Quantum, Seagate Res, Sony Corp, Magnequench Technol Ctr, AJA Int Inc, Digital Measurement Syst ID T-C; LA1.2SR1.8MN2O7; SPIN AB Magnetization experiments were performed on a series of single crystals of the bilayer manganites La2-2xSr1+2xMn2O7. The magnetic anisotropy constants were determined by fitting expressions based on the tetragonal anisotropy energy to the magnetization curves. It is shown that there is a significant dipolar contribution to the first order anisotropy constant arising from the layered crystal structure. This contribution determines the magnetization direction in the doping range x = 0.32-0.33 where the anisotropy due to the electronic structure is small. With increasing doping the magnetic anisotropy changes from strong uniaxial anong the c axis (K approximate to 2.5 x 10(6) erg/cm(3)) at x = 0.3 to strong easy plane (K approximate to -3.7 x 10(6) erg/cm(3)) at x = 0.4 in an almost linear fashion. This evolution is explained through the change of the orbital nature of the e(g) electrons from predominantly d(3z2-r2) to predominantly d(x2-y2). On the samples displaying easy-plane anisotropy a small anisotropy in the basal plane of about -7 x 10(4) erg/cm(3) was determined with (110) being the easy axis. An estimate of the spin-wave gap based on these results is in reasonable agreement with experimental determinations. (C) 2001 American Institute of Physics. C1 Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. RP Welp, U (reprint author), Argonne Natl Lab, Div Mat Sci, 9700 S Cass Ave, Argonne, IL 60439 USA. RI Berger, Andreas/D-3706-2015; You, Hoydoo/A-6201-2011 OI Berger, Andreas/0000-0001-5865-6609; You, Hoydoo/0000-0003-2996-9483 NR 17 TC 8 Z9 8 U1 1 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 JUN 1 PY 2001 VL 89 IS 11 BP 6621 EP 6623 DI 10.1063/1.1357136 PN 2 PG 3 WC Physics, Applied SC Physics GA 440AV UT WOS:000169151700014 ER PT J AU Jiang, JS Inomata, A You, CY Pearson, JE Bader, SD AF Jiang, JS Inomata, A You, CY Pearson, JE Bader, SD TI Magnetic stability in exchange-spring and exchange-bias systems after multiple switching cycles SO JOURNAL OF APPLIED PHYSICS LA English DT Article; Proceedings Paper CT 8th Joint MMM/Intermag Conference CY JAN 08-11, 2001 CL SAN ANTONIO, TEXAS SP Motorola Labs, TDK Corp, IBM, Toda Kogyo Corp, EMTEC Magnet GmbH, Quantum, Seagate Res, Sony Corp, Magnequench Technol Ctr, AJA Int Inc, Digital Measurement Syst ID GIANT MAGNETORESISTANCE; ANISOTROPY; FE/CR(211); FILMS AB We have studied the magnetic stability in exchange-bias and exchange-spring systems during repeated reversal of the pinned layer. The samples were prepared by epitaxial sputter deposition. The exchange-biased system consists of a combination of ferromagnetic and antiferromagnetic Fe/Cr superlattices. The exchange-spring system is a bilayer structure made of hard Sm-Co and soft Fe ferromagnetic layers. The magnetic properties were investigated using the magneto-optic Kerr effect during repeated reversal of the soft layer magnetization by field cycling up to 10(7) times. The experimentally observed decay behaviors are discussed in terms of microstructure and spin configuration of the pinning layers. (C) 2001 American Institute of Physics. C1 Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. Fujitsu Ltd, Atsugi, Kanagawa, Japan. RP Jiang, JS (reprint author), Argonne Natl Lab, Div Mat Sci, 9700 S Cass Ave, Argonne, IL 60439 USA. RI You, Chun-Yeol/B-1734-2010; Bader, Samuel/A-2995-2013 OI You, Chun-Yeol/0000-0001-9549-8611; NR 10 TC 6 Z9 6 U1 0 U2 1 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 JUN 1 PY 2001 VL 89 IS 11 BP 6817 EP 6819 DI 10.1063/1.1359787 PN 2 PG 3 WC Physics, Applied SC Physics GA 440AV UT WOS:000169151700078 ER PT J AU Vasiliu-Doloc, L Osborn, R Rosenkranz, S Mesot, J Mitchell, JF Sinha, SK Seeck, OH Lynn, JW Islam, Z AF Vasiliu-Doloc, L Osborn, R Rosenkranz, S Mesot, J Mitchell, JF Sinha, SK Seeck, OH Lynn, JW Islam, Z TI Neutron and x-ray evidence of charge melting in ferromagnetic layered colossal magnetoresistance manganites (invited) SO JOURNAL OF APPLIED PHYSICS LA English DT Article; Proceedings Paper CT 8th Joint MMM/Intermag Conference CY JAN 08-11, 2001 CL SAN ANTONIO, TEXAS SP Motorola Labs, TDK Corp, IBM, Toda Kogyo Corp, EMTEC Magnet GmbH, Quantum, Seagate Res, Sony Corp, Magnequench Technol Ctr, AJA Int Inc, Digital Measurement Syst ID DIFFUSE-SCATTERING; POLARON FORMATION; LA1.2SR1.8MN2O7; LA1-XCAXMNO3; LA1-XSRXMNO3; RESISTIVITY; TRANSITION; DISTORTION; COLLAPSE; STRIPES AB Recent x-ray and neutron scattering studies have revealed static diffuse scattering due to polarons in the paramagnetic phase of the colossal magnetoresistive manganites La2-2xSr1+2xMn2O7, with x = 0.40 and 0.44. We show that the polarons exhibit short-range incommensurate correlations that grow with decreasing temperature, but disappear abruptly at the combined ferromagnetic and metal-insulator transition in the x = 0.40 system because of the sudden charge delocalization, while persisting at low temperature in the antiferromagnetic x = 0.44 system. The "melting" of the polaron ordering as we cool through T-C occurs with the collapse of the polaron scattering itself in the x = 0.40 system. This short-range polaron order is characterized by an ordering wave vector q = (0.3,0,1) that is almost independent of x for x greater than or equal to 0.38, and is consistent with a model of disordered stripes. (C) 2001 American Institute of Physics. C1 No Illinois Univ, Dept Phys, De Kalb, IL 60115 USA. Argonne Natl Lab, Adv Photon Source, Argonne, IL 60439 USA. Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. Natl Inst Stand & Technol, Ctr Neutron Res, Gaithersburg, MD 20899 USA. RP Vasiliu-Doloc, L (reprint author), No Illinois Univ, Dept Phys, De Kalb, IL 60115 USA. RI Osborn, Raymond/E-8676-2011; Rosenkranz, Stephan/E-4672-2011 OI Osborn, Raymond/0000-0001-9565-3140; Rosenkranz, Stephan/0000-0002-5659-0383 NR 28 TC 4 Z9 4 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 JUN 1 PY 2001 VL 89 IS 11 BP 6840 EP 6845 DI 10.1063/1.1365256 PN 2 PG 6 WC Physics, Applied SC Physics GA 440AV UT WOS:000169151700086 ER PT J AU Berger, A Mitchell, JF Miller, DJ Bader, SD AF Berger, A Mitchell, JF Miller, DJ Bader, SD TI Evidence for competing order parameters in the paramagnetic phase of layered manganites (invited) SO JOURNAL OF APPLIED PHYSICS LA English DT Article; Proceedings Paper CT 8th Joint MMM/Intermag Conference CY JAN 08-11, 2001 CL SAN ANTONIO, TEXAS SP Motorola Labs, TDK Corp, IBM, Toda Kogyo Corp, EMTEC Magnet GmbH, Quantum, Seagate Res, Sony Corp, Magnequench Technol Ctr, AJA Int Inc, Digital Measurement Syst ID SPIN-FLOP TRANSITION; T-C; GIANT MAGNETORESISTANCE; MAGNETIC CORRELATIONS; SINGLE-CRYSTALS; LA1.2SR1.8MN2O7; LA1.4SR1.6MN2O7; INTERGROWTHS; OXIDES AB The magnetic field and temperature dependence of the magnetic susceptibility is studied for the ferromagnetic layered manganites SrO(La1-xSrxMnO3)(2) in the composition range x = 0.32-0.40. In the paramagnetic phase, the susceptibility exhibits an anomalous maximum at an intermediate magnetic field value. The size of this field-induced susceptibility enhancement increases dramatically with x from 10% for x = 0.32 to 160% for x = 0.40. The temperature dependence of the effect shows a maximum at T approximate to 1.1 T-C for all x. Quantitative analysis in terms of the Landau theory of phase transitions enables us to identify a distortion of the free energy F in the paramagnetic phase that is associated with the susceptibility anomaly. This free energy distortion corresponds to a magnetic system that approaches a first order magnetic phase transition as the temperature is lowered toward T-C. Such a behavior is indicative of a second, competing order parameter, which is identified as the recently observed charge density wave. In the immediate vicinity of T-C, the anomaly disappears and the system seems to undergo a more conventional second order paramagnetic-ferromagnetic phase transition. (C) 2001 American Institute of Physics. C1 Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. RP Berger, A (reprint author), Argonne Natl Lab, Div Mat Sci, 9700 S Cass Ave, Argonne, IL 60439 USA. RI Bader, Samuel/A-2995-2013; Berger, Andreas/D-3706-2015 OI Berger, Andreas/0000-0001-5865-6609 NR 32 TC 10 Z9 10 U1 0 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 JUN 1 PY 2001 VL 89 IS 11 BP 6851 EP 6856 DI 10.1063/1.1360681 PN 2 PG 6 WC Physics, Applied SC Physics GA 440AV UT WOS:000169151700088 ER PT J AU Moghadam, NY Stocks, GM Kowalewski, M Butler, WH AF Moghadam, NY Stocks, GM Kowalewski, M Butler, WH TI Effects of Ta on the magnetic structure of permalloy SO JOURNAL OF APPLIED PHYSICS LA English DT Article; Proceedings Paper CT 8th Joint MMM/Intermag Conference CY JAN 08-11, 2001 CL SAN ANTONIO, TX SP Motorola Labs, TDK Corp, IBM, Toda Kogyo Corp, EMTEC Magnet GmbH, Quantum, Seagate Res, Sony Corp, Magnequench Technol Ctr, AJA Int Inc, Digital Measurement Syst ID POTENTIALS AB In permalloy (Py) based heterostructures Ta has deleterious effects on the magnetic properties resulting in magnetic dead layers. Using the Korringa-Kohn-Rostoker coherent potential approximation method, it is shown that the average moment of Py (Ni0.8Fe0.2) is rapidly quenched by Ta substitutional additions. Locally self-consistent multiple-scattering method calculations for large supercell models of Py0.9Ta0.1 show that Ta additions also result in substantial fluctuations in the size of the local moments. The configuration dependent reductions in the local moments are larger for Ni than for Fe sites and are the largest for Ni sites closest to Ta. (C) 2001 American Institute of Physics. C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. EM nassrin@gmsis.ms.ornl.gov RI Stocks, George Malcollm/Q-1251-2016 OI Stocks, George Malcollm/0000-0002-9013-260X NR 11 TC 7 Z9 7 U1 0 U2 7 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 JUN 1 PY 2001 VL 89 IS 11 BP 6886 EP 6888 DI 10.1063/1.1356032 PN 2 PG 3 WC Physics, Applied SC Physics GA 440AV UT WOS:000169151700097 ER PT J AU Sant, S Mao, M Kools, J Koi, K Iwasaki, H Sahashi, M AF Sant, S Mao, M Kools, J Koi, K Iwasaki, H Sahashi, M TI Giant magnetoresistance in ion beam deposited spin-valve films with specular enhancement SO JOURNAL OF APPLIED PHYSICS LA English DT Article; Proceedings Paper CT 8th Joint MMM/Intermag Conference CY JAN 08-11, 2001 CL SAN ANTONIO, TEXAS SP Motorola Labs, TDK Corp, IBM, Toda Kogyo Corp, EMTEC Magnet GmbH, Quantum, Seagate Res, Sony Corp, Magnequench Technol Ctr, AJA Int Inc, Digital Measurement Syst AB Three different techniques, natural oxidation, remote plasma oxidation and low energy ion beam oxidation, have been proved to be equally effective in forming nano-oxide layers (NOLs) in spin-valve films for specular enhancement of giant magnetoresistance (GMR) effect. GMR values over 12% have been routinely obtained in spin-valve films with NOL, corresponding to a 30% specular enhancement over those without NOL. The consistency and robustness of the oxidation processes has been demonstrated by a very large GMR value similar to 19% in a dual spin-valve film with the NOLs formed in both pinned layers, the oscillatory dependence of the interlayer coupling field on Cu layer thickness in specular enhanced spin-valve films and the uniform and repeatable film performance over 5 in. substrates. (C) 2001 American Institute of Physics. C1 Veeco Technol Ctr, San Jose, CA 95119 USA. Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. Toshiba Corp, Ctr Corp Res & Dev, Kawasaki, Kanagawa 2128552, Japan. RP Sant, S (reprint author), Veeco Technol Ctr, San Jose, CA 95119 USA. RI Kools, Jacques/A-3863-2013 NR 4 TC 17 Z9 17 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 JUN 1 PY 2001 VL 89 IS 11 BP 6931 EP 6933 DI 10.1063/1.1356718 PN 2 PG 3 WC Physics, Applied SC Physics GA 440AV UT WOS:000169151700112 ER PT J AU Uhlig, WC Mao, M Yiu, V Li, J Shi, J AF Uhlig, WC Mao, M Yiu, V Li, J Shi, J TI Temperature dependent specular scattering enhancement in Cu-wedge spin valves SO JOURNAL OF APPLIED PHYSICS LA English DT Article; Proceedings Paper CT 8th Joint MMM/Intermag Conference CY JAN 08-11, 2001 CL SAN ANTONIO, TEXAS SP Motorola Labs, TDK Corp, IBM, Toda Kogyo Corp, EMTEC Magnet GmbH, Quantum, Seagate Res, Sony Corp, Magnequench Technol Ctr, AJA Int Inc, Digital Measurement Syst ID GIANT MAGNETORESISTANCE; MULTILAYERS AB Magneto-transport properties have been systematically studied in Cu-wedge regular and specular spin valves prepared by magnetron sputtering. In the specular spin valve, a thin oxide layer is inserted between the Ta underlayer and the free layer to provide a specular interface. Up to 50% enhancement in giant magnetoresistance (GMR) is realized by the specular interface at room temperature. The observed Cu layer thickness dependence of both the resistivity and GMR in both types of the spin valves has been satisfactorily modeled using a semiclassical Boltzmann approach. Temperature dependence of the GMR has been measured from 325 to 15 K for several Cu-layer thicknesses. The specular scattering enhancement initially increases as the temperature is lowered from 325 K, but rapidly decreases below 100 K. This decrease is correlated with the reduced degree of the full antiparallel alignment between the magnetic moments of the pinned and free layers in the specular spin valve, which is caused by the antiferromagnetic ordering of the oxide layer. (C) 2001 American Institute of Physics. C1 Univ Utah, Dept Phys, Salt Lake City, UT 84112 USA. Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Shi, J (reprint author), Univ Utah, Dept Phys, 115 South 1500 E, Salt Lake City, UT 84112 USA. NR 7 TC 3 Z9 3 U1 0 U2 1 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 JUN 1 PY 2001 VL 89 IS 11 BP 6937 EP 6939 DI 10.1063/1.1356720 PN 2 PG 3 WC Physics, Applied SC Physics GA 440AV UT WOS:000169151700114 ER PT J AU Gibbons, MR Mao, M Chien, C AF Gibbons, MR Mao, M Chien, C TI Comparison of semiclassical calculations to experiment for spin valve films grown on oxide surfaces SO JOURNAL OF APPLIED PHYSICS LA English DT Article; Proceedings Paper CT 8th Joint MMM/Intermag Conference CY JAN 08-11, 2001 CL SAN ANTONIO, TEXAS SP Motorola Labs, TDK Corp, IBM, Toda Kogyo Corp, EMTEC Magnet GmbH, Quantum, Seagate Res, Sony Corp, Magnequench Technol Ctr, AJA Int Inc, Digital Measurement Syst ID MAGNETORESISTANCE; SCATTERING AB The physical properties of spin valve films grown on the surface of nano-oxide layers were studied as a function of Cu spacer layer thickness. In comparison to identical structures without the oxide surface, the films exhibited an increase in DeltaR/R of 30% accompanied by a reduction of only 5% in resistance. Semiclassical calculations were preformed on these films with a close match to experiment. Assuming the oxide layer did not cause drastic changes in the properties of the other film layers, the specular reflection was changed to obtain a match with experiment. The increase in giant magnetoresistance response was achieved by increasing the specular reflection at the metal/oxide interfaces from 15% to 85%, indicating high efficiency for specular reflection at the nano-oxide interface. (C) 2001 American Institute of Physics. C1 Read Rite Corp, Fremont, CA 94539 USA. Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94500 USA. RP Gibbons, MR (reprint author), Read Rite Corp, 44100 Osgood Rd, Fremont, CA 94539 USA. NR 8 TC 2 Z9 2 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 JUN 1 PY 2001 VL 89 IS 11 BP 6949 EP 6951 DI 10.1063/1.1356721 PN 2 PG 3 WC Physics, Applied SC Physics GA 440AV UT WOS:000169151700118 ER PT J AU Gibbons, MR Sin, K Funada, S Mao, M Rao, D Chien, C Tong, HC AF Gibbons, MR Sin, K Funada, S Mao, M Rao, D Chien, C Tong, HC TI Micromagnetic simulation of tunneling magnetoresistance junctions with parallel hard bias SO JOURNAL OF APPLIED PHYSICS LA English DT Article; Proceedings Paper CT 8th Joint MMM/Intermag Conference CY JAN 08-11, 2001 CL SAN ANTONIO, TEXAS SP Motorola Labs, TDK Corp, IBM, Toda Kogyo Corp, EMTEC Magnet GmbH, Quantum, Seagate Res, Sony Corp, Magnequench Technol Ctr, AJA Int Inc, Digital Measurement Syst AB Tunneling magnetoresistance (TMR) films and devices were simulated to understand the response of the free layer with a parallel hard bias. In order to determine the effect of the granular hard bias material micromagnetic simulation was used to model both the hard bias and TMR material. Minimizing hysteresis and Barkhausen jumps in the response of the device involves an optimization of the spacing between the free layer and the hard bias coupled with the shape of the device edges. (C) 2001 American Institute of Physics. C1 Read Rite Corp, Fremont, CA 94539 USA. Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94500 USA. RP Gibbons, MR (reprint author), Read Rite Corp, 44100 Osgood Rd, Fremont, CA 94539 USA. NR 4 TC 0 Z9 0 U1 0 U2 1 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 JUN 1 PY 2001 VL 89 IS 11 BP 7003 EP 7005 DI 10.1063/1.1355331 PN 2 PG 3 WC Physics, Applied SC Physics GA 440AV UT WOS:000169151700136 ER PT J AU Zhu, B Lo, CCH Lee, SJ Jiles, DC AF Zhu, B Lo, CCH Lee, SJ Jiles, DC TI Micromagnetic modeling of the effects of stress on magnetic properties SO JOURNAL OF APPLIED PHYSICS LA English DT Article; Proceedings Paper CT 8th Joint MMM/Intermag Conference CY JAN 08-11, 2001 CL SAN ANTONIO, TEXAS SP Motorola Labs, TDK Corp, IBM, Toda Kogyo Corp, EMTEC Magnet GmbH, Quantum, Seagate Res, Sony Corp, Magnequench Technol Ctr, AJA Int Inc, Digital Measurement Syst ID DEPENDENCE AB A micromagnetic model has been developed for investigating the effect of stress on the magnetic properties of thin films. This effect has been implemented by including the magnetoelastic energy term into the Landau-Lifshitz-Gilbert equation. Magnetization curves of a nickel film were calculated under both tensile and compressive stresses of various magnitudes applied along the field direction. The modeling results show that coercivity increased with increasing compressive stress while remanence decreased with increasing tensile stress. The results are in agreement with the experimental data in the literature and can be interpreted in terms of the effects of the applied stress on the irreversible rotation of magnetic moments during magnetization reversal under an applied field. (C) 2001 American Institute of Physics. C1 Iowa State Univ, Ctr Nondestruct Evaluat, Ames, IA 50011 USA. Iowa State Univ, US Dept Energy, Ames Lab, Ames, IA 50011 USA. RP Zhu, B (reprint author), Iowa State Univ, Ctr Nondestruct Evaluat, Ames, IA 50011 USA. RI Jiles, David/H-9548-2012 NR 11 TC 37 Z9 39 U1 1 U2 13 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 JUN 1 PY 2001 VL 89 IS 11 BP 7009 EP 7011 DI 10.1063/1.1363604 PN 2 PG 3 WC Physics, Applied SC Physics GA 440AV UT WOS:000169151700138 ER PT J AU Schulthess, TC Butler, WH AF Schulthess, TC Butler, WH TI Electronic structure and magnetic interactions in Mn doped semiconductors SO JOURNAL OF APPLIED PHYSICS LA English DT Article; Proceedings Paper CT 8th Joint MMM/Intermag Conference CY JAN 08-11, 2001 CL SAN ANTONIO, TEXAS SP Motorola Labs, TDK Corp, IBM, Toda Kogyo Corp, EMTEC Magnet GmbH, Quantum, Seagate Res, Sony Corp, Magnequench Technol Ctr, AJA Int Inc, Digital Measurement Syst ID III-V SEMICONDUCTORS; MOLECULAR-DYNAMICS; FERROMAGNETISM; (IN,MN)AS; METALS AB The electronic structures of several magnetic semiconductors were calculated using first-principles based electronic structure techniques. Calculations were performed both for periodic supercells and for disordered systems which were treated within the coherent potential approximation. Our results differ from the conventional atomic model for the Mn impurity. We find strong hybridization between the majority Mn d states and the majority valence band. We find that substitutional Mn impurities add states and electrons to the majority valence band but not to the minority. We find relatively strong carrier induced magnetic interactions between impurities. The sign of these interactions may however, change sign as a function of the distance between the impurities. (C) 2001 American Institute of Physics. C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Schulthess, TC (reprint author), Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. NR 11 TC 44 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 JUN 1 PY 2001 VL 89 IS 11 BP 7021 EP 7023 DI 10.1063/1.1359456 PN 2 PG 3 WC Physics, Applied SC Physics GA 440AV UT WOS:000169151700142 ER PT J AU Martinho, H Moreno, NO Sanjurjo, JA Rettori, C Garcia-Adeva, AJ Huber, DL Oseroff, SB Ratcliff, W Cheong, SW Pagliuso, PG Sarrao, JL Martins, GB AF Martinho, H Moreno, NO Sanjurjo, JA Rettori, C Garcia-Adeva, AJ Huber, DL Oseroff, SB Ratcliff, W Cheong, SW Pagliuso, PG Sarrao, JL Martins, GB TI Studies of the three-dimensional frustrated antiferromagnetic ZnCr2O4 SO JOURNAL OF APPLIED PHYSICS LA English DT Article; Proceedings Paper CT 8th Joint MMM/Intermag Conference CY JAN 08-11, 2001 CL SAN ANTONIO, TEXAS SP Motorola Labs, TDK Corp, IBM, Toda Kogyo Corp, EMTEC Magnet GmbH, Quantum, Seagate Res, Sony Corp, Magnequench Technol Ctr, AJA Int Inc, Digital Measurement Syst AB Results of studies of the susceptibility, magnetic specific heat, and electron paramagnetic resonance spectrum of the geometrically frustrated antiferromagnetic ZnCr2O4 are presented. The temperature dependence of the susceptibility and the specific heat are in good agreement with the predictions of the quantum tetrahedral mean field model for exchange-coupled spin-3/2 ions on a pyrochlore lattice. The origin of the anomalous behavior of the resonance intensity below 90 K is discussed. (C) 2001 American Institute of Physics. C1 UNICAMP, Inst Fis Gleb Wataghin, BR-13083970 Campinas, SP, Brazil. Univ Wisconsin, Dept Phys, Madison, WI 53706 USA. San Diego State Univ, San Diego, CA 92182 USA. Rutgers State Univ, Dept Phys & Astron, Piscataway, NJ 08854 USA. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Florida State Univ, Natl High Magnet Field Lab, Tallahassee, FL 32306 USA. RP Martinho, H (reprint author), UNICAMP, Inst Fis Gleb Wataghin, BR-13083970 Campinas, SP, Brazil. RI Rettori, Carlos/C-3966-2012; Pagliuso, Pascoal/C-9169-2012; Moreno, Nelson/H-1708-2012; Garcia Adeva, Angel/L-5157-2014; Martinho, Herculano/F-4684-2015; Martins, George/C-9756-2012; Optica e Eletronica, Laboratorio/A-8669-2014; Inst. of Physics, Gleb Wataghin/A-9780-2017 OI Rettori, Carlos/0000-0001-6692-7915; Moreno, Nelson/0000-0002-1672-4340; Garcia Adeva, Angel/0000-0003-2776-2390; Martins, George/0000-0001-7846-708X; NR 11 TC 22 Z9 22 U1 0 U2 15 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 JUN 1 PY 2001 VL 89 IS 11 BP 7050 EP 7052 DI 10.1063/1.1358340 PN 2 PG 3 WC Physics, Applied SC Physics GA 440AV UT WOS:000169151700151 ER PT J AU Grimsditch, M Guedes, I Vavassori, P Metlushko, V Ilic, B Neuzil, P Kumar, R AF Grimsditch, M Guedes, I Vavassori, P Metlushko, V Ilic, B Neuzil, P Kumar, R TI Brillouin scattering and diffracted magneto-optical Kerr effect from arrays of dots and antidots (invited) SO JOURNAL OF APPLIED PHYSICS LA English DT Article; Proceedings Paper CT 8th Joint MMM/Intermag Conference CY JAN 08-11, 2001 CL SAN ANTONIO, TEXAS SP Motorola Labs, TDK Corp, IBM, Toda Kogyo Corp, EMTEC Magnet GmbH, Quantum, Seagate Res, Sony Corp, Magnequench Technol Ctr, AJA Int Inc, Digital Measurement Syst ID PERMALLOY ARRAYS; SQUARE LATTICE; MAGNETIZATION; ANISOTROPY; DOMAIN AB The magnetic properties of nanoarrays have been investigated using Brillouin scattering, magneto-optical Kerr effect (MOKE) and diffracted-MOKE (DMOKE) techniques. The anisotropies in negative arrays are found to be due to the shape of the holes and not due to the array itself. The DMOKE results allow us to extract the domain pattern at remanence. (C) 2001 American Institute of Physics. C1 Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. Univ Ferrara, INFM, Dept Phys, Ferrara, Italy. Univ Illinois, Dept Elect Engn & Comp Sci, Chicago, IL 60607 USA. Cornell Univ, Sch Appl & Engn Phys, Ithaca, NY 14853 USA. Inst Microelect, Moscow 117865, Russia. Dept Fis, BR-60455760 Fortaleza, Ceara, Brazil. RP Grimsditch, M (reprint author), Argonne Natl Lab, Div Mat Sci, 9700 S Cass Ave, Argonne, IL 60439 USA. RI Neuzil, Pavel/B-9981-2012; GUEDES, ILDE/C-3451-2013; Ilic, Rob/N-1359-2014; Vavassori, Paolo/B-4299-2014; UFC, DF/E-1564-2017; Universidade Federal do Ceara, Physics Department/J-4630-2016; OI Vavassori, Paolo/0000-0002-4735-6640; Universidade Federal do Ceara, Physics Department/0000-0002-9247-6780; GUEDES, ILDE/0000-0002-1040-5891 NR 14 TC 17 Z9 17 U1 0 U2 7 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 JUN 1 PY 2001 VL 89 IS 11 BP 7096 EP 7100 DI 10.1063/1.1359789 PN 2 PG 5 WC Physics, Applied SC Physics GA 440AV UT WOS:000169151700165 ER PT J AU Enders, A Monchesky, TL Myrtle, K Urban, R Heinrich, B Kirschner, J Zhang, XG Butler, WH AF Enders, A Monchesky, TL Myrtle, K Urban, R Heinrich, B Kirschner, J Zhang, XG Butler, WH TI The role of interfaces in the magnetoresistance of Au/Fe/Au/Fe/GaAs(001) SO JOURNAL OF APPLIED PHYSICS LA English DT Article; Proceedings Paper CT 8th Joint MMM/Intermag Conference CY JAN 08-11, 2001 CL SAN ANTONIO, TEXAS SP Motorola Labs, TDK Corp, IBM, Toda Kogyo Corp, EMTEC Magnet GmbH, Quantum, Seagate Res, Sony Corp, Magnequench Technol Ctr, AJA Int Inc, Digital Measurement Syst ID MAGNETIC MULTILAYERS AB The electron transport and magnetoresistance (MR) were investigated in high quality crystalline epitaxial Fe(001) and Au(001) films and exchange coupled Au/Fe/Au/Fe/GaAs(001) trilayer structures. Fits to the experimental data were based on the semiclassical Boltzmann equation, which incorporates the electronic properties obtained from first-principles local density functional calculations. The fits require a surprisingly high asymmetry for the spin dependent electron lifetimes in Fe, tau (down arrow)/tau (up arrow) = 10 at room temperature. Despite the large atomic terraces at the Au/vacuum and Fe/GaAs interfaces the scattering at the outer interfaces was found to be diffuse. The origin of MR in Au/Fe/Au/Fe/GaAs(001) structures is due to electron channeling in the Au spacer layer. The measured MR is consistent with the diffusivity parameters s(up arrow) = 0.55, s(down arrow) = 0.77 at the metal-metal interfaces. (C) 2001 American Institute of Physics. C1 Simon Fraser Univ, Dept Phys, Burnaby, BC V5A 1S6, Canada. Max Planck Inst, D-06120 Halle, Germany. Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Enders, A (reprint author), Simon Fraser Univ, Dept Phys, 8888 Univ Dr, Burnaby, BC V5A 1S6, Canada. OI Monchesky, Theodore/0000-0001-7401-7866 NR 9 TC 18 Z9 18 U1 1 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 JUN 1 PY 2001 VL 89 IS 11 BP 7110 EP 7112 DI 10.1063/1.1357844 PN 2 PG 3 WC Physics, Applied SC Physics GA 440AV UT WOS:000169151700168 ER PT J AU Fischer, P Eimuller, T Schutz, G Kohler, M Bayreuther, G Denbeaux, G Attwood, D AF Fischer, P Eimuller, T Schutz, G Kohler, M Bayreuther, G Denbeaux, G Attwood, D TI Study of in-plane magnetic domains with magnetic transmission x-ray microscopy SO JOURNAL OF APPLIED PHYSICS LA English DT Article; Proceedings Paper CT 8th Joint MMM/Intermag Conference CY JAN 08-11, 2001 CL SAN ANTONIO, TEXAS SP Motorola Labs, TDK Corp, IBM, Toda Kogyo Corp, EMTEC Magnet GmbH, Quantum, Seagate Res, Sony Corp, Magnequench Technol Ctr, AJA Int Inc, Digital Measurement Syst AB Magnetic transmission x-ray microscopy is a novel technique to image element specifically magnetic domain structures. A lateral resolution down to 25 nm is provided by the Fresnel zone plates used as optical elements in soft x-ray microscopy. The magnetic contrast is given by x-ray magnetic circular dichroism, i.e., large magnetic contributions up to 25% to the absorption cross section of circularly polarized x rays that occur in the vicinity of, e.g., the Fe L-3,L-2 edges (706 and 719 eV) and depend on the relative orientation of the projection of the magnetization of the sample onto the photon propagation direction. Thus, both in-plane and out-of-plane contributions to the magnetization are accessible. Here we present images of the magnetic domain structure of a (3 nm Cr/50 nm Fe/6 nm Cr) thin film system with a preferentially in-plane magnetization recorded at the Fe L edges. The samples have been prepared by thermal evaporation onto a 100 nm thin Si3N4 membrane and were mounted under a tilt of 30 degrees with respect to the transmission direction of the photons in the full-field microscope. Corresponding images taken under a tilt of 0 degrees ruled out out-of-plane contributions. Images recorded in applied varying external magnetic fields allowed to study the switching behavior. These trial results have a large impact on further investigations of nanostructured magnetic systems, e.g., spintronic devices and magnetic sensors with magnetic soft x-ray microscopy. (C) 2001 American Institute of Physics. C1 Univ Wurzburg, EP 4, D-97074 Wurzburg, Germany. Univ Regensburg, D-93040 Regensburg, Germany. Univ Calif Berkeley, Lawrence Berkeley Lab, Ctr Xray Opt, Berkeley, CA 94720 USA. RP Fischer, P (reprint author), Univ Wurzburg, EP 4, D-97074 Wurzburg, Germany. RI Fischer, Peter/A-3020-2010 OI Fischer, Peter/0000-0002-9824-9343 NR 7 TC 27 Z9 29 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 JUN 1 PY 2001 VL 89 IS 11 BP 7159 EP 7161 DI 10.1063/1.1355333 PN 2 PG 3 WC Physics, Applied SC Physics GA 440AV UT WOS:000169151700185 ER PT J AU Pollmann, J Srajer, G Haskel, D Lang, JC Maser, J Jiang, JS Bader, SD AF Pollmann, J Srajer, G Haskel, D Lang, JC Maser, J Jiang, JS Bader, SD TI Magnetic imaging of a buried SmCo layer in a spring magnet SO JOURNAL OF APPLIED PHYSICS LA English DT Article; Proceedings Paper CT 8th Joint MMM/Intermag Conference CY JAN 08-11, 2001 CL SAN ANTONIO, TEXAS SP Motorola Labs, TDK Corp, IBM, Toda Kogyo Corp, EMTEC Magnet GmbH, Quantum, Seagate Res, Sony Corp, Magnequench Technol Ctr, AJA Int Inc, Digital Measurement Syst ID POLARIZED X-RAYS; FILMS; ANISOTROPY AB Images of the magnetic domain structure in a 1600 Angstrom thick buried SmCo layer of a Fe/SmCo spring magnet were obtained using a newly developed x-ray microprobe. This probe combines circularly polarizing optics with a microfocusing Fresnel zone plate to obtain a highly polarized, small cross-section x-ray beam in the energy range between 5 and 10 keV. X-ray magnetic circular dichroism was used to provide contrast between different magnetic domains as a function of the externally applied magnetic field. The obtained images show domain walls not oriented parallel to the external field but correlated with structural features in the sample. A plausible explanation is pinning of domain walls at stacking faults in the layer. The range of external fields for which the magnetic reorientation of a particular microscopic domain occurred was much smaller than the range measured for a macroscopic hysteresis loop, indicating that the reorientation is due to growth of domains developed at local nucleation points. (C) 2001 American Institute of Physics. C1 Argonne Natl Lab, Adv Photon Source, Argonne, IL 60439 USA. Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. RP Pollmann, J (reprint author), Argonne Natl Lab, Adv Photon Source, Argonne, IL 60439 USA. RI Bader, Samuel/A-2995-2013; Maser, Jorg/K-6817-2013 NR 10 TC 9 Z9 9 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 JUN 1 PY 2001 VL 89 IS 11 BP 7165 EP 7167 DI 10.1063/1.1360391 PN 2 PG 3 WC Physics, Applied SC Physics GA 440AV UT WOS:000169151700187 ER PT J AU De Graef, M Zhu, YM AF De Graef, M Zhu, YM TI Quantitative noninterferometric lorentz microscopy SO JOURNAL OF APPLIED PHYSICS LA English DT Article; Proceedings Paper CT 8th Joint MMM/Intermag Conference CY JAN 08-11, 2001 CL SAN ANTONIO, TEXAS SP Motorola Labs, TDK Corp, IBM, Toda Kogyo Corp, EMTEC Magnet GmbH, Quantum, Seagate Res, Sony Corp, Magnequench Technol Ctr, AJA Int Inc, Digital Measurement Syst ID TRANSMISSION ELECTRON-MICROSCOPE; PHASE; RETRIEVAL AB Noninterferometric phase reconstruction based on the transport of intensity equation (TIE) is applied to experimental images for a Permalloy thin film and to a computational magnetization pattern for a high density magnetic recording medium. An alternative derivation of the TIE is given, based on linear image formation theory. A compact formal solution, suitable for numerical computation, is given. (C) 2001 American Institute of Physics. C1 Carnegie Mellon Univ, Dept Mat Sci & Engn, Pittsburgh, PA 15213 USA. Brookhaven Natl Lab, Dept Appl Sci, Upton, NY 11973 USA. RP De Graef, M (reprint author), Carnegie Mellon Univ, Dept Mat Sci & Engn, Pittsburgh, PA 15213 USA. RI DeGraef, Marc/G-5827-2010 OI DeGraef, Marc/0000-0002-4721-6226 NR 10 TC 29 Z9 29 U1 1 U2 15 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 JUN 1 PY 2001 VL 89 IS 11 BP 7177 EP 7179 DI 10.1063/1.1355337 PN 2 PG 3 WC Physics, Applied SC Physics GA 440AV UT WOS:000169151700191 ER PT J AU Chang, S Jung, MH Nakotte, H Bruck, E Klaasse, JCP Mihalik, M Lacerda, AH Prokes, K Torikachvili, MS Schultz, AJ AF Chang, S Jung, MH Nakotte, H Bruck, E Klaasse, JCP Mihalik, M Lacerda, AH Prokes, K Torikachvili, MS Schultz, AJ TI Electronic properties of UIrGe in high magnetic fields SO JOURNAL OF APPLIED PHYSICS LA English DT Article; Proceedings Paper CT 8th Joint MMM/Intermag Conference CY JAN 08-11, 2001 CL SAN ANTONIO, TEXAS SP Motorola Labs, TDK Corp, IBM, Toda Kogyo Corp, EMTEC Magnet GmbH, Quantum, Seagate Res, Sony Corp, Magnequench Technol Ctr, AJA Int Inc, Digital Measurement Syst ID TERNARY AB UIrGe crystallizes in the orthorhombic TiNiSi structure and exhibits a large magnetic anisotropy. Here, we present the results of magnetoresistance and specific-heat studies of single-crystalline UIrGe in magnetic fields up to 18 T applied along the principal axes. The phase boundaries of the zero-field antiferromagnetic phase (T-N approximate to 14.1 K) are established, and we find evidence of a field-induced phase above 12.5 T at 2.1 K and 14 T at 2.5 K for magnetic fields applied along the b and c axis, respectively. (C) 2001 American Institute of Physics. C1 New Mexico State Univ, Phys Dept MSC3D, Las Cruces, NM 88003 USA. Univ Amsterdam, Van der Waals Zeeman Inst, NL-1018 XE Amsterdam, Netherlands. Univ Calif Los Alamos Natl Lab, Pulsed Field Facil, Natl High Magnet Field Lab, Los Alamos, NM 87545 USA. Hahn Meitner Inst Kernforsch Berlin GmbH, D-14109 Berlin, Germany. San Diego State Univ, Dept Phys, San Diego, CA 92182 USA. Argonne Natl Lab, IPNS, Argonne, IL 60439 USA. Slovak Acad Sci, Inst Expt Phys, Kosice 04354, Slovakia. RP Chang, S (reprint author), New Mexico State Univ, Phys Dept MSC3D, Las Cruces, NM 88003 USA. RI Bruck, Ekkes/E-3365-2014 NR 8 TC 4 Z9 4 U1 0 U2 7 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 JUN 1 PY 2001 VL 89 IS 11 BP 7186 EP 7188 DI 10.1063/1.1357847 PN 2 PG 3 WC Physics, Applied SC Physics GA 440AV UT WOS:000169151700194 ER PT J AU Scholl, A Nolting, F Stohr, J Regan, T Luning, J Seo, JW Locquet, JP Fompeyrine, J Anders, S Ohldag, H Padmore, HA AF Scholl, A Nolting, F Stohr, J Regan, T Luning, J Seo, JW Locquet, JP Fompeyrine, J Anders, S Ohldag, H Padmore, HA TI Exploring the microscopic origin of exchange bias with photoelectron emission microscopy (invited) SO JOURNAL OF APPLIED PHYSICS LA English DT Article; Proceedings Paper CT 8th Joint MMM/Intermag Conference CY JAN 08-11, 2001 CL SAN ANTONIO, TEXAS SP Motorola Labs, TDK Corp, IBM, Toda Kogyo Corp, EMTEC Magnet GmbH, Quantum, Seagate Res, Sony Corp, Magnequench Technol Ctr, AJA Int Inc, Digital Measurement Syst ID MAGNETIC-MATERIALS; THIN-FILMS AB It is well known that magnetic exchange coupling across the ferromagnet-antiferromagnet interface results in an unidirectional magnetic anisotropy of the ferromagnetic layer, called exchange bias. Despite large experimental and theoretical efforts, the origin of exchange bias is still controversial, mainly because detection of the interfacial magnetic structure is difficult. We have applied photoelectron emission microscopy (PEEM) on several ferromagnet-antiferromagnet thin-film structures and microscopically imaged the ferromagnetic and the antiferromagnetic structure with high spatial resolution. Taking advantage of the surface sensitivity and elemental specificity of PEEM, the magnetic configuration and critical properties such as the Neel temperature were determined on LaFeO3 and NiO thin films and single crystals. On samples coated with a ferromagnetic layer, we microscopically observe exchange coupling across the interface, causing a clear correspondence of the domain structures in the adjacent ferromagnet and antiferromagnet. Field dependent measurements reveal a strong uniaxial anisotropy in individual ferromagnetic domains. A local exchange bias was observed even in not explicitly field-annealed samples, caused by interfacial uncompensated magnetic spins. These experiments provide highly desired information on the relative orientation of electron spins at the interface between ferromagnets and antiferromagnets. (C) 2001 American Institute of Physics. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Adv Light Source, Berkeley, CA 94720 USA. Stanford Synchrotron Radiat Lab, Stanford, CA 95120 USA. Stanford Univ, Dept Appl Phys, Stanford, CA 94305 USA. IBM Corp, Div Res, Zurich Res Lab, CH-8803 Ruschlikon, Switzerland. Univ Neuchatel, Inst Phys, CH-2000 Neuchatel, Switzerland. IBM Corp, Almaden Res Ctr, Div Res, San Jose, CA 95120 USA. Univ Dusseldorf, Inst Appl Phys, D-40225 Dusseldorf, Germany. RP Scholl, A (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Adv Light Source, 1 Cyclotron Rd, Berkeley, CA 94720 USA. RI Seo, Jin Won/J-3980-2013; Scholl, Andreas/K-4876-2012; Ohldag, Hendrik/F-1009-2014; Raoux, Simone/G-3920-2016 OI Seo, Jin Won/0000-0003-4937-0769; NR 11 TC 12 Z9 12 U1 0 U2 9 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 JUN 1 PY 2001 VL 89 IS 11 BP 7266 EP 7268 DI 10.1063/1.1358828 PN 2 PG 3 WC Physics, Applied SC Physics GA 440AV UT WOS:000169151700221 ER PT J AU Zein, NE Antropov, VP AF Zein, NE Antropov, VP TI Universal and specific contributions in the density-like functionals: Application to transition metals SO JOURNAL OF APPLIED PHYSICS LA English DT Article; Proceedings Paper CT 8th Joint MMM/Intermag Conference CY JAN 08-11, 2001 CL SAN ANTONIO, TEXAS SP Motorola Labs, TDK Corp, IBM, Toda Kogyo Corp, EMTEC Magnet GmbH, Quantum, Seagate Res, Sony Corp, Magnequench Technol Ctr, AJA Int Inc, Digital Measurement Syst ID APPROXIMATION; EXCHANGE; SEMICONDUCTORS; SOLIDS AB We present an approach for obtaining generating functionals for density-functional-like theory, which takes into account the structure of electronic levels near Fermi surface and density variations at distances exceeding the screening radius in metals. Materials-specific information is contained mainly in these structure-dependent terms, while other terms depend mainly on the local density. We used proposed method to study the electronic structure of ferromagnetic Fe and Ni and obtain reasonable agreement with previous local density calculations and experiment. (C) 2001 American Institute of Physics. C1 Iowa State Univ Sci & Technol, Ames Lab, Ames, IA 50011 USA. RP Zein, NE (reprint author), Iowa State Univ Sci & Technol, Ames Lab, Ames, IA 50011 USA. NR 16 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 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD JUN 1 PY 2001 VL 89 IS 11 BP 7314 EP 7316 DI 10.1063/1.1357855 PN 2 PG 3 WC Physics, Applied SC Physics GA 440AV UT WOS:000169151700237 ER PT J AU Sin, K Gibbons, MR Funada, S Mao, M Rao, D Chien, C Tong, HC AF Sin, K Gibbons, MR Funada, S Mao, M Rao, D Chien, C Tong, HC TI Spin-dependent tunneling junctions with parallel hard bias for read heads SO JOURNAL OF APPLIED PHYSICS LA English DT Article; Proceedings Paper CT 8th Joint MMM/Intermag Conference CY JAN 08-11, 2001 CL SAN ANTONIO, TEXAS SP Motorola Labs, TDK Corp, IBM, Toda Kogyo Corp, EMTEC Magnet GmbH, Quantum, Seagate Res, Sony Corp, Magnequench Technol Ctr, AJA Int Inc, Digital Measurement Syst AB We investigated the feasibility of a spin-dependent tunneling (SDT) read head with a parallel hard bias. In this scheme, the longitudinal biasing to the free layer is provided by fringe fields from a hard magnet which is fabricated over or under the free layer. A linear response to the applied field is achieved for a SDT junction biased with 400 Angstrom CoCrPt underneath. Thinner CoCrPt layers yield Barkhausen jumps in the free layer. Micromagnetic simulation indicates the bias field at the edge of the free layer is smaller than that which would result from an abutted magnet. The simulation results are similar to experimental data, and indicate that shielded devices with 400 Angstrom permanent magnet will provide stable transfer curves. (C) 2001 American Institute of Physics. C1 Read Rite Corp, Fremont, CA 94539 USA. Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Sin, K (reprint author), Read Rite Corp, 44100 Osgood Rd, Fremont, CA 94539 USA. 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 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD JUN 1 PY 2001 VL 89 IS 11 BP 7359 EP 7361 DI 10.1063/1.1361051 PN 2 PG 3 WC Physics, Applied SC Physics GA 440AV UT WOS:000169151700252 ER PT J AU Rao, D Sin, K Gibbons, M Funada, S Mao, M Chien, C Tong, HC AF Rao, D Sin, K Gibbons, M Funada, S Mao, M Chien, C Tong, HC TI Voltage-induced barrier-layer damage in spin-dependent tunneling junctions SO JOURNAL OF APPLIED PHYSICS LA English DT Article; Proceedings Paper CT 8th Joint MMM/Intermag Conference CY JAN 08-11, 2001 CL SAN ANTONIO, TEXAS SP Motorola Labs, TDK Corp, IBM, Toda Kogyo Corp, EMTEC Magnet GmbH, Quantum, Seagate Res, Sony Corp, Magnequench Technol Ctr, AJA Int Inc, Digital Measurement Syst ID BREAKDOWN AB The effect of a dc stress voltage on the junction resistance and magnetoresistance (MR) of spin-dependent tunneling (SDT) junctions with naturally oxidized barriers was investigated. There is a threshold voltage at which irreversible resistance change begins. Beyond this threshold, device resistance decreases gradually over a transition period prior to breakdown of the tunneling barrier. The onset voltage of irreversible resistance change is much higher than the optimum operating voltage of SDT heads having the precursor aluminum thicknesses here investigated (5-11 Angstrom). The MR ratio decreased with increasing stress voltage in a pattern similar to that of the junction resistance. (C) 2001 American Institute of Physics. C1 Read Rite Corp, Fremont, CA 94539 USA. Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Rao, D (reprint author), Read Rite Corp, 44100 Osgood Rd, Fremont, CA 94539 USA. NR 6 TC 15 Z9 15 U1 0 U2 1 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 JUN 1 PY 2001 VL 89 IS 11 BP 7362 EP 7364 DI 10.1063/1.1359228 PN 2 PG 3 WC Physics, Applied SC Physics GA 440AV UT WOS:000169151700253 ER PT J AU Berger, A Inomata, A Jiang, JS Pearson, JE Bader, SD Dahmen, K AF Berger, A Inomata, A Jiang, JS Pearson, JE Bader, SD Dahmen, K TI Disorder-driven hysteresis-loop criticality in Co/CoO films SO JOURNAL OF APPLIED PHYSICS LA English DT Article; Proceedings Paper CT 8th Joint MMM/Intermag Conference CY JAN 08-11, 2001 CL SAN ANTONIO, TEXAS SP Motorola Labs, TDK Corp, IBM, Toda Kogyo Corp, EMTEC Magnet GmbH, Quantum, Seagate Res, Sony Corp, Magnequench Technol Ctr, AJA Int Inc, Digital Measurement Syst ID SELF-ORGANIZED CRITICALITY; FERROMAGNETIC DOMAIN-WALL; BARKHAUSEN NOISE; MAGNETIC-MATERIALS; AVALANCHES; DYNAMICS; DIMENSIONS; EXPONENTS; BEHAVIOR; MODEL AB The effect of magnetic disorder on the magnetization reversal process in thin Co/CoO films has been investigated. The antiferromagnetic CoO layer allows a reversible tuning of the magnetic disorder by simple temperature variation. For temperatures above a critical temperature T-c, we observe a discontinuous magnetization reversal, whereas smooth magnetization loops occur for T < T-c. Our measurements establish the existence of a disorder-driven critical point in the nonequilibrium phase diagram. In addition, we observe scaling behavior in the vicinity of the critical point and determine the critical exponents to beta = 0.022 +/-0.006 and beta delta = 0.30 +/-0.03. (C) 2001 American Institute of Physics. C1 Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. Univ Illinois, Dept Phys, Urbana, IL 61801 USA. Fujitsu File Memory Lab, Atsugi, Kanagawa, Japan. RP Berger, A (reprint author), Argonne Natl Lab, Div Mat Sci, 9700 S Cass Ave, Argonne, IL 60439 USA. RI Bader, Samuel/A-2995-2013; Berger, Andreas/D-3706-2015 OI Berger, Andreas/0000-0001-5865-6609 NR 25 TC 7 Z9 8 U1 2 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 JUN 1 PY 2001 VL 89 IS 11 BP 7466 EP 7468 DI 10.1063/1.1361272 PN 2 PG 3 WC Physics, Applied SC Physics GA 440AV UT WOS:000169151700285 ER PT J AU Weller, D Folks, L Best, M Fullerton, EE Terris, BD Kusinski, GJ Krishnan, KM Thomas, G AF Weller, D Folks, L Best, M Fullerton, EE Terris, BD Kusinski, GJ Krishnan, KM Thomas, G TI Growth, structural, and magnetic properties of high coercivity Co/Pt multilayers SO JOURNAL OF APPLIED PHYSICS LA English DT Article; Proceedings Paper CT 8th Joint MMM/Intermag Conference CY JAN 08-11, 2001 CL SAN ANTONIO, TEXAS SP Motorola Labs, TDK Corp, IBM, Toda Kogyo Corp, EMTEC Magnet GmbH, Quantum, Seagate Res, Sony Corp, Magnequench Technol Ctr, AJA Int Inc, Digital Measurement Syst ID RECORDING MEDIA AB Electron beam evaporated Co/Pt multilayers {[Co(t(Co) nm)/Pt(1 nm)](10), 0.2 < t(Co) < 2 nm} with perpendicular magnetic anisotropy and room temperature coercivities H-c = 2-15 kOe are studied as a function of growth temperature T-G. Hysteresis loops and magnetic force microscopy (MFM) indicate changes in the magnetization reversal mechanism along with a sharp increase in coercivity for T(G)greater than or similar to 230-250 degreesC. Films grown at T-G < 230 degreesC (t(Co) = 0.2-0.4 nm) show micrometer size magnetic domains and rectangular hysteresis indicating magnetization reversal dominated by rapid domain wall motion following nucleation at H-n similar to H-c. Films grown at T-G > 250 degreesC show fine-grained MFM features on the sub-100-nm length scale indicating reversal dominated by localized switching of small clusters. High-resolution cross-sectional transmission electron microscopy (TEM) with elemental analysis shows columnar grains extending throughout the multilayer stack. Co depletion and structural defects at the grain boundaries provide a mechanism for exchange decoupling of adjacent grains, which may result in the high coercivities observed. (C) 2001 American Institute of Physics. C1 IBM Corp, Almaden Res Ctr, San Jose, CA 95120 USA. Univ Calif Berkeley, Dept Mat Sci & Engn, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. RP Weller, D (reprint author), Seagate Technol LLC, 2403 Sidney St, Pittsburgh, PA 15203 USA. RI Fullerton, Eric/H-8445-2013; Folks, Liesl/C-7611-2016 OI Fullerton, Eric/0000-0002-4725-9509; Folks, Liesl/0000-0003-0161-957X NR 9 TC 62 Z9 62 U1 3 U2 25 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 JUN 1 PY 2001 VL 89 IS 11 BP 7525 EP 7527 DI 10.1063/1.1363602 PN 2 PG 3 WC Physics, Applied SC Physics GA 440AV UT WOS:000169151700304 ER PT J AU Crew, DC Lewis, LH Kim, J Barmak, K AF Crew, DC Lewis, LH Kim, J Barmak, K TI Magnetic signature of compositional gradient in exchange-spring bilayer films of CoPt/Co SO JOURNAL OF APPLIED PHYSICS LA English DT Article; Proceedings Paper CT 8th Joint MMM/Intermag Conference CY JAN 08-11, 2001 CL SAN ANTONIO, TEXAS SP Motorola Labs, TDK Corp, IBM, Toda Kogyo Corp, EMTEC Magnet GmbH, Quantum, Seagate Res, Sony Corp, Magnequench Technol Ctr, AJA Int Inc, Digital Measurement Syst ID ANISOTROPY AB Experimental studies were performed on model bilayers of fully ordered L1(0) CoPt with thicknesses of 25, 50, or 100 nm, capped by Co of varying thicknesses from 2.6-75 nm. The bilayers were subjected to different annealing conditions; transmission electron microscopy and x-ray diffraction supplied data concerning the crystallographic structure, microstructure, and texture of the constituent phases in the bilayers. The degree of exchange coupling was investigated primarily with magnetic measurement and magnetic force microscopy. Samples subjected to annealing treatments at 300 degreesC showed evidence of grain growth and increased texture of the hexagonally close-packed (hcp) cobalt layer relative to the as-deposited condition. The degree of exchange coupling in these materials improved only slightly with annealing, as evidenced by both magnetic recoil curve measurement and magnetic force microscopy. Samples subjected to a higher-temperature annealing treatment of 550 degreesC evidenced dramatic improvement in the magnetic coupling, an improvement attributed to interdiffusion of CoPt and Co and the formation of alloy phases, specifically face-centered-cubic and hcp Co-Pt solid solutions. (C) 2001 American Institute of Physics. C1 Brookhaven Natl Lab, Energy Sci & Technol Dept, Div Mat & Chem Sci, Upton, NY 11973 USA. Lehigh Univ, Dept Mat Sci & Engn, Bethlehem, PA 18015 USA. Carnegie Mellon Univ, Dept Mat Sci & Engn, Pittsburgh, PA 15213 USA. RP Crew, DC (reprint author), Brookhaven Natl Lab, Energy Sci & Technol Dept, Div Mat & Chem Sci, Upton, NY 11973 USA. RI Barmak, Katayun/A-9804-2008 OI Barmak, Katayun/0000-0003-0070-158X NR 5 TC 4 Z9 4 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 JUN 1 PY 2001 VL 89 IS 11 BP 7528 EP 7530 DI 10.1063/1.1354594 PN 2 PG 3 WC Physics, Applied SC Physics GA 440AV UT WOS:000169151700305 ER PT J AU Schulthess, TC Benakli, M Visscher, PB Sorge, KD Thompson, JR Modine, FA Haynes, TE Boatner, LA Stocks, GM Butler, WH AF Schulthess, TC Benakli, M Visscher, PB Sorge, KD Thompson, JR Modine, FA Haynes, TE Boatner, LA Stocks, GM Butler, WH TI Role of magnetostatic interactions in assemblies of Fe nanoparticles SO JOURNAL OF APPLIED PHYSICS LA English DT Article; Proceedings Paper CT 8th Joint MMM/Intermag Conference CY JAN 08-11, 2001 CL SAN ANTONIO, TEXAS SP Motorola Labs, TDK Corp, IBM, Toda Kogyo Corp, EMTEC Magnet GmbH, Quantum, Seagate Res, Sony Corp, Magnequench Technol Ctr, AJA Int Inc, Digital Measurement Syst ID FERROMAGNETIC PARTICLES AB It has recently become possible to synthesize a class of nanostructured materials by ion implantation. The implanted ions aggregate into crystallographically oriented nanoscale inclusions in the host material. We have performed simulations of the magnetization curves for such assemblies of nanoscale Fe inclusions in a nonmagnetic host. We use random positions for the magnetic particles (not a regular grid) and include magnetostatic interactions in detail. We find that these materials are not adequately described by standard noninteracting theories-interactions have a significant effect. In particular, interactions can mask the effects of crystallite orientation, producing nearly isotropic hysteresis curves. The use of a noninteracting model could thus lead one to conclude, incorrectly, that the inclusions are randomly oriented. (C) 2001 American Institute of Physics. C1 Oak Ridge Natl Lab, Div Math & Comp Sci, Oak Ridge, TN 37831 USA. Quantum Corp, Shrewsbury, MA 01545 USA. Univ Alabama, Dept Phys, Tuscaloosa, AL 35487 USA. Univ Alabama, MINT Ctr, Tuscaloosa, AL 35487 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 Schulthess, TC (reprint author), Oak Ridge Natl Lab, Div Math & Comp Sci, Oak Ridge, TN 37831 USA. RI Haynes, Tony/P-8932-2015; Boatner, Lynn/I-6428-2013; Stocks, George Malcollm/Q-1251-2016; OI Haynes, Tony/0000-0003-2871-4745; Boatner, Lynn/0000-0002-0235-7594; Stocks, George Malcollm/0000-0002-9013-260X; Visscher, Pieter/0000-0002-3457-4593 NR 7 TC 11 Z9 12 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 JUN 1 PY 2001 VL 89 IS 11 BP 7594 EP 7596 DI 10.1063/1.1363608 PN 2 PG 3 WC Physics, Applied SC Physics GA 440AV UT WOS:000169151700327 ER PT J AU Mao, M Cerjan, C Hung, S Miloslavsky, L Chien, C Sant, S AF Mao, M Cerjan, C Hung, S Miloslavsky, L Chien, C Sant, S TI Thermal stability of magnetron and ion beam sputtered top and bottom spin-valve films SO JOURNAL OF APPLIED PHYSICS LA English DT Article; Proceedings Paper CT 8th Joint MMM/Intermag Conference CY JAN 08-11, 2001 CL SAN ANTONIO, TEXAS SP Motorola Labs, TDK Corp, IBM, Toda Kogyo Corp, EMTEC Magnet GmbH, Quantum, Seagate Res, Sony Corp, Magnequench Technol Ctr, AJA Int Inc, Digital Measurement Syst AB The thermal stability of top and bottom IrMn exchange-biased spin-valve films prepared by ion beam deposition (IBD) and magnetron sputtering physical vapor deposition (PVD) is compared. These films exhibit identical temperature dependence for the exchange bias field H-ex, with a blocking temperature of T-B = 250 degreesC, that is independent of preparation technique. Isothermal annealing at temperatures below T-B led to a ln(t) dependent degradation in H-ex, suggesting a thermal activation process. The high crystallographic quality of the IBD films leads to a superior stability compared to PVD films. Top spin-valve films are also found to be more stable than bottom spin-valve films. (C) 2001 American Institute of Physics. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. Read Rite Corp, Fremont, CA 94539 USA. Veeco Instruments Inc, San Jose, CA 95119 USA. RP Cerjan, C (reprint author), Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. NR 4 TC 0 Z9 0 U1 0 U2 0 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 JUN 1 PY 2001 VL 89 IS 11 BP 7628 EP 7630 DI 10.1063/1.1357863 PN 2 PG 3 WC Physics, Applied SC Physics GA 440AV UT WOS:000169151700338 ER PT J AU Jung, MH Yoshino, T Kawasaki, S Pietrus, T Bando, Y Suemitsu, T Sera, M Takabatake, T AF Jung, MH Yoshino, T Kawasaki, S Pietrus, T Bando, Y Suemitsu, T Sera, M Takabatake, T TI Thermoelectric and transport properties of CeBiPt and LaBiPt SO JOURNAL OF APPLIED PHYSICS LA English DT Article; Proceedings Paper CT 8th Joint MMM/Intermag Conference CY JAN 08-11, 2001 CL SAN ANTONIO, TEXAS SP Motorola Labs, TDK Corp, IBM, Toda Kogyo Corp, EMTEC Magnet GmbH, Quantum, Seagate Res, Sony Corp, Magnequench Technol Ctr, AJA Int Inc, Digital Measurement Syst ID PRPTBI AB The electrical resistivity rho, Hall coefficient R-H, thermoelectric power S, and thermal conductivity kappa have been measured on an antiferromagnet CeBiPt (T-N = 1 K) and the nonmagnetic analogue LaBiPt, which crystallize in the cubic MgAgAs-type structure. The large values \R-H\ similar to 1 cm(3)/C and rho similar to 1.2 m Ohm cm at 300 K indicate that both compounds are low-carrier concentration semimetals. The strong temperature dependences of rho, S, and R-H for CeBiPt contrast with the weak temperature dependences for LaBiPt. For CeBiPt, S(T) has a positive maximum of 120 muV/K at 100 K. However, the sign of R-H(T) changes from positive to negative with increasing temperature at 170 K, above which S(T) of CeBiPt becomes smaller than LaBiPt. These observations suggest strong dependence of mobility for hole and electron carriers in CeBiPt. In this system, kappa (T) is dominated by the phonon contribution, which is consistent with a small carrier concentration. Furthermore, the combination of S, rho, and kappa allows us to estimate the figure of merit for thermoelectric application, Z = 1.7 x 10(-4) K-1 at 75 K for CeBiPt. (C) 2001 American Institute of Physics. C1 Hiroshima Univ, ADSM, Dept Quantum Matter, Higashihiroshima 7398526, Japan. Univ Karlsruhe, Inst Phys, D-76128 Karlsruhe, Germany. Kure Natl Coll Technol, Dept Elect Engn, Kure 7378506, Japan. RP Jung, MH (reprint author), Univ Calif Los Alamos Natl Lab, Natl High Magnet Field Lab, Pulse Facil, MS E536, Los Alamos, NM 87545 USA. RI Takabatake, Toshiro/L-2882-2014 OI Takabatake, Toshiro/0000-0002-3293-8592 NR 9 TC 12 Z9 12 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 JUN 1 PY 2001 VL 89 IS 11 BP 7631 EP 7633 DI 10.1063/1.1357864 PN 2 PG 3 WC Physics, Applied SC Physics GA 440AV UT WOS:000169151700339 ER PT J AU Lebed, JB Chechetkin, VR Turygin, AY Shick, VV Mirzabekov, AD AF Lebed, JB Chechetkin, VR Turygin, AY Shick, VV Mirzabekov, AD TI Comparison of complex DNA mixtures with generic oligonucleotide microchips SO JOURNAL OF BIOMOLECULAR STRUCTURE & DYNAMICS LA English DT Article ID DIABETES-MELLITUS; T-CELLS; HYBRIDIZATION; NOD; ARRAYS; SEQUENCE; DUPLEXES; MICE AB The reproducibility of melting curves for repeated hybridizations of target DNA with generic oligonucleotide microchips is shown experimentally to depend on the character of matching between fragments of target DNA and immobilized oligonucleotides. The reproducibility of melting curves is higher for the perfect match duplexes and decreases as the number of mismatched pairs within duplexes increases. This effect was applied to the comparative analysis of complex DNA mixtures. We developed a scheme in which we can identify and discriminate between the probe oligonucleotides responsible for the distinctions between target DNA mixtures. A scheme is illustrated by comparing DNA mixtures corresponding to V-D-J genes connected with populations of mRNAs CDR3 TCR Vb (T-cell receptor beta complementarity determining region 3) from the thymus and pancreas of NOD mice. Our results demonstrate that generic microchips can be applied efficiently to the analysis of DNA mixtures. C1 Russian Acad Sci, Engelhardt Inst Mol Biol, Joint Human Genome Program, Moscow 117984, Russia. Argonne Natl Lab, Biochip Technol Ctr, Argonne, IL 60439 USA. RP Mirzabekov, AD (reprint author), Russian Acad Sci, Engelhardt Inst Mol Biol, Joint Human Genome Program, 32 Vavilov Str, Moscow 117984, Russia. NR 36 TC 7 Z9 7 U1 0 U2 0 PU ADENINE PRESS INC PI GUILDERLAND PA PO BOX 355/340, GUILDERLAND, NY 12084 USA SN 0739-1102 J9 J BIOMOL STRUCT DYN JI J. Biomol. Struct. Dyn. PD JUN PY 2001 VL 18 IS 6 BP 813 EP 823 PG 11 WC Biochemistry & Molecular Biology; Biophysics SC Biochemistry & Molecular Biology; Biophysics GA 445CC UT WOS:000169439700003 PM 11444370 ER PT J AU DeWitt, AE Dong, JY Wiley, HS Lauffenburger, DA AF DeWitt, AE Dong, JY Wiley, HS Lauffenburger, DA TI Quantitative analysis of the EGF receptor autocrine system reveals cryptic regulation of cell response by ligand capture SO JOURNAL OF CELL SCIENCE LA English DT Article DE autocrine; EGF; computational model ID EPIDERMAL GROWTH-FACTOR; MAMMARY EPITHELIAL-CELLS; CANINE KIDNEY-CELLS; HEPARIN-BINDING; FACTOR-ALPHA; TGF-ALPHA; TRANSGENIC MICE; RAT-LIVER; POSTENDOCYTIC TRAFFICKING; CAENORHABDITIS-ELEGANS AB Autocrine signaling is important in normal tissue physiology as well as pathological conditions. It is difficult to analyze these systems, however, because they are both self-contained and recursive. To understand how parameters such as ligand production and receptor expression influence autocrine activity, we investigated a human epidermal growth factor/epidermal growth factor receptor (EGF/ECFR) loop engineered into mouse B82 fibroblasts, We varied the level of ligand production using the tet-off expression system and used metalloprotease inhibitors to modulate ligand release. Receptor expression was varied using antagonistic blocking antibodies. We compared autocrine ligand release with receptor activation using a microphysiometer-based assay and analyzed our data using a quantitative model of ligand release and receptor dynamics. We found that the activity of our autocrine system could be described in terms of a simple ratio between the rate of ligand production (V-LT) and the rate of receptor production (V-R) At a V-LT/V-R ratio of <0.3, essentially no ligand was found in the extracellular medium, but a significant number of cell receptors (30-40%) were occupied. As the V-LT/V-R ratio increased from 0.3 towards unity, receptor occupancy increased and significant amounts of ligand appeared in the medium. Above a V-LT/V-R ratio of 1.0, receptor occupancy approached saturation and most of the released ligand was lost into the medium. Analysis of human mammary epithelial cells showed that a V-LT/V-R ratio of <5x10(-4) was sufficient to evoke >20% of a maximal proliferative response, This demonstrates that natural autocrine systems can be active even when no ligand appears in the extracellular medium. C1 MIT, Dept Chem Engn, Cambridge, MA 02139 USA. Childrens Hosp, Boston, MA 02115 USA. Pacific NW Natl Lab, Fundamental Sci Div, Richland, WA 99352 USA. MIT, Div Bioengn & Environm Hlth, Cambridge, MA 02139 USA. MIT, Ctr Canc Res, Cambridge, MA 02139 USA. RP Lauffenburger, DA (reprint author), MIT, Dept Chem Engn, Cambridge, MA 02139 USA. OI Wiley, Steven/0000-0003-0232-6867 FU NICHD NIH HHS [P01-HD288528] NR 66 TC 62 Z9 62 U1 0 U2 5 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 JUN PY 2001 VL 114 IS 12 BP 2301 EP 2313 PG 13 WC Cell Biology SC Cell Biology GA 451FL UT WOS:000169790400010 PM 11493669 ER PT J AU Thoss, M Wang, HB Miller, WH AF Thoss, M Wang, HB Miller, WH TI Generalized forward-backward initial value representation for the calculation of correlation functions in complex systems SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID THERMAL RATE CONSTANTS; ELECTRONICALLY NONADIABATIC DYNAMICS; CUMULATIVE REACTION PROBABILITIES; TIME-CORRELATION FUNCTIONS; HERMAN-KLUK PROPAGATOR; SEMICLASSICAL CALCULATION; VIBRATIONAL COHERENCE; MOLECULAR-DYNAMICS; LINEARIZED APPROXIMATION; PHOTODISSOCIATION DYNAMICS AB The capability of two different, recently proposed semiclassical (SC) forward-backward (FB) initial value representations (IVR) to describe quantum interference and coherence effects is investigated. It is shown that depending on the way the observable under consideration is represented by unitary operators one can obtain rather different results. Although the FB-IVR based on an integral representation as a rule is capable of describing quantum interference, a closer analysis reveals that it depends on the observable under consideration if all interference that can be described semiclassically is actually included in the calculation. To overcome this problem a new, generalized FB-IVR method (GFB-IVR) is proposed, which combines the capability of the SC-IVR to describe quantum interference effects independent of the observable and the better convergence properties of the FB-IVR. The performance of this new approach is studied in some detail. In particular, it is shown that the GFB-IVR can describe both the coherent and incoherent regime in the dynamics of an anharmonic vibration coupled to a harmonic bath. (C) 2001 American Institute of Physics. C1 Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. Univ Calif Berkeley, Kenneth S Pitzer Ctr Theoret Chem, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Chem Sci, Berkeley, CA 94720 USA. RP Thoss, M (reprint author), Tech Univ Munich, D-85747 Garching, Germany. RI Wang, Haobin/E-1208-2011; Thoss, Michael/C-5976-2013 NR 94 TC 124 Z9 125 U1 1 U2 8 PU AMER INST PHYSICS PI MELVILLE PA 1305 WALT WHITMAN RD, STE 300, MELVILLE, NY 11747-4501 USA SN 0021-9606 EI 1089-7690 J9 J CHEM PHYS JI J. Chem. Phys. PD JUN 1 PY 2001 VL 114 IS 21 BP 9220 EP 9235 DI 10.1063/1.1359242 PG 16 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 434BF UT WOS:000168794700003 ER PT J AU Dunning, TH Peterson, KA Wilson, AK AF Dunning, TH Peterson, KA Wilson, AK TI Gaussian basis sets for use in correlated molecular calculations. X. The atoms aluminum through argon revisited SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID TOTAL ATOMIZATION ENERGIES; PLESSET MP2-R12 CALCULATIONS; ELECTRIC QUADRUPOLE-MOMENT; AUGMENTED SEXTUPLE-ZETA; CONSISTENT BASIS-SETS; QUARTIC FORCE-FIELD; WAVE-FUNCTIONS; AB-INITIO; BENCHMARK CALCULATIONS; CORRELATION CUSP AB For molecules containing second row atoms, unacceptable errors have been found in extrapolating dissociation energies calculated with the standard correlation consistent basis sets to the complete basis set limit. By carefully comparing the convergence behavior of D-e(O-2) and D-e(SO), we show that the cause of these errors is a result of two inter-related problems: near duplication of the exponents in two of the d sets and a lack of high-exponent functions in the early members of the sets. Similar problems exist for the f sets (and probably in higher angular momentum sets), but have only a minor effect on the calculated dissociation energies. A number of approaches to address the problems in the d sets were investigated. Well behaved convergence was obtained by augmenting the (1d) and (2d) sets with a high-exponent function and by replacing the (3d) set by the (4d) set and the (4d) set by the (5d) set and so on. To ensure satisfactory coverage of both the L and M shell regions, the exponents of the new d sets were re-optimized. Benchmark calculations on Si-2, PN, SO, and AlCl with the new cc-pV(n+d)Z sets show greatly improved convergence behavior not only for D-e but for many other properties as well. (C) 2001 American Institute of Physics. C1 Pacific NW Natl Lab, William R Wiley Environm Mol Sci Lab, Richland, WA 99352 USA. Washington State Univ, Dept Chem, Richland, WA 99352 USA. RP Dunning, TH (reprint author), Pacific NW Natl Lab, William R Wiley Environm Mol Sci Lab, Richland, WA 99352 USA. NR 73 TC 886 Z9 885 U1 1 U2 65 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 JUN 1 PY 2001 VL 114 IS 21 BP 9244 EP 9253 DI 10.1063/1.1367373 PG 10 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 434BF UT WOS:000168794700005 ER PT J AU Curtiss, LA Redfern, PC Rassolov, V Kedziora, G Pople, JA AF Curtiss, LA Redfern, PC Rassolov, V Kedziora, G Pople, JA TI Extension of gaussian-3 theory to molecules containing third-row atoms K, Ca, Ga-Kr SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID DENSITY-FUNCTIONAL THEORIES; BASIS-SETS; CONFIGURATION-INTERACTION; PARAMETER-X; G2 THEORY; PCI-X; ENERGIES; COMPUTATION; POTENTIALS; ELEMENTS AB Gaussian-3 (G3) theory is extended to molecules containing the third-row nontransition elements K, Ca, Ga-Kr. Basis sets compatible with those used in G3 theory for molecules containing first- and second-row atoms have been derived. The G3 average absolute deviation from experiment for a set of 47 test reactions containing these elements is 0.94 kcal/mol. This is a substantial improvement over Gaussian-2 theory, which has an average absolute deviation of 1.43 kcal/mol for the same set. Variations of G3 theory are also presented that are based on reduced orders of perturbation theory. These variations also show similar improvement over the corresponding G2 methods. The use of scaling parameters in G3 theory for the third row was investigated and found to perform nearly as well as use of the higher level correction. In addition, these methods are evaluated on a set of molecules containing K and Ca for which the experimental data are not accurate enough for them to be included in the test set. Results for this set indicate that G3 theory performs significantly better than G2 for molecules containing Ca. When the 47 third-row systems are added to the G3/99 database the complete G3 average absolute deviation becomes 1.06 kcal/mol for 423 energies. (C) 2001 American Institute of Physics. C1 Argonne Natl Lab, Div Chem, Argonne, IL 60439 USA. Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. Northwestern Univ, Dept Chem, Evanston, IL 60208 USA. RP Curtiss, LA (reprint author), Argonne Natl Lab, Div Chem, 9700 S Cass Ave, Argonne, IL 60439 USA. EM curtiss@anl.gov OI Rassolov, Vitaly/0000-0002-7244-8870 NR 42 TC 140 Z9 140 U1 0 U2 13 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 JUN 1 PY 2001 VL 114 IS 21 BP 9287 EP 9295 DI 10.1063/1.1366337 PG 9 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 434BF UT WOS:000168794700009 ER PT J AU Marriott, RA Hakin, AW Rard, JA AF Marriott, RA Hakin, AW Rard, JA TI Apparent molar heat capacities and apparent molar volumes of Y-2(SO4)(3)(aq), La-2(SO4)(3)(aq), Pr-2(SO4)(3)(aq), Nd-2(SO4)(3)(aq),Eu-2(SO4)(3)(aq), Dy-2(SO4)(3)(aq), Ho-2(SO4)(3)(aq), and Lu-2(SO4)(3)(aq) at T=298.15 K and p=0.1 MPa SO JOURNAL OF CHEMICAL THERMODYNAMICS LA English DT Article DE apparent molar heat capacities; apparent molar volumes; rare-earth(III) sulfates; aqueous solutions ID EARTH ELECTROLYTE-SOLUTIONS; STANDARD-STATE ENTROPIES; TEMPERATURES 283 K; ISOPIESTIC DETERMINATION; ACTIVITY-COEFFICIENTS; THERMODYNAMIC PROPERTIES; FLOW MICROCALORIMETRY; CHEMICAL-EQUILIBRIA; INORGANIC COMPLEXES; PITZER EQUATIONS AB The apparent molar heat capacities C degrees (p,phi) and apparent molar volumes V degrees (phi) of Y-2(SO4)(3)(aq), La-2(SO4)(3)(aq), Pr-2(SO4)(3)(aq), Nd-2(SO4)(3)(aq), Eu-2(SO4)(3)(aq), Dy-2(SO4)(3)(aq), Ho-2(SO4)(3)(aq), and Lu-2(SO4)(3)(aq) were measured at T = 298.15 K and p = 0.1 MPa with a Sodev (Picker) flow microcalorimeter and a Sodev vibrating-tube densimeter, respectively. These measurements extend from lower molalities of m = (0.005 to 0.018) mol . kg(-1) to m = (0.025 to 0.434) mol . kg(-1), where the upper molality limits are slightly below those of the saturated solutions. There are no previously published apparent molar heat capacities for these systems, and only limited apparent molar volume information. Considerable amounts of the RSO4+(aq) and R(SO4)(2)(-)(aq) complexes are present, where R denotes a rare-earth, which complicates the interpretation of these thermodynamic quantities. Values of the ionic molar heat capacities and ionic molar volumes of these complexes at infinite dilution are derived from the experimental information, but the calculations are necessarily quite approximate because of the need to estimate ionic activity coefficients and other thermodynamic quantities. Nevertheless, the derived standard ionic molar properties for the various RSO4+(aq) and R(SO4)(2)(-)(aq) complexes are probably realistic approximations to the actual values. Comparisons indicate that V degrees (phi){RSO4+ aq, 298.15 K} = -(6 +/-4)cm(3). mol(-1) and V(phi)degrees {R(SO4)(2)(-), aq, 298.15 K} = (35 +/-3) cm(3). mol(-1), with no significant variation with rare-earth. In contrast, values of C degrees (p,phi){RSO4+, aq, 298.15 K} generally increase with the atomic number of the rare-earth, whereas C degrees (p,phi){R(SO4)(2)(-), aq, 298.15 K} shows a less regular trend, although its values are always positive and tend to be larger for the heavier than for the light rare earths. (C) 2001 Academic Press. C1 Dalhousie Univ, Dept Chem, Halifax, NS B3H 4J3, Canada. Univ Lethbridge, Dept Chem & Biochem, Lethbridge, AB T1K 3M4, Canada. Lawrence Livermore Natl Lab, Energy & Environm Directorate, Livermore, CA 94550 USA. RP Marriott, RA (reprint author), Dalhousie Univ, Dept Chem, Halifax, NS B3H 4J3, Canada. NR 85 TC 20 Z9 20 U1 0 U2 3 PU ACADEMIC PRESS LTD PI LONDON PA 24-28 OVAL RD, LONDON NW1 7DX, ENGLAND SN 0021-9614 J9 J CHEM THERMODYN JI J. Chem. Thermodyn. PD JUN PY 2001 VL 33 IS 6 BP 643 EP 687 DI 10.1006/jcht.2000.0792 PG 45 WC Thermodynamics; Chemistry, Physical SC Thermodynamics; Chemistry GA 476CC UT WOS:000171207800004 ER PT J AU Sugama, T Kelley, SS Gawlik, K AF Sugama, T Kelley, SS Gawlik, K TI Hydrothermal degradation study of phenolic polymer coatings by advanced analytical methods SO JOURNAL OF COATINGS TECHNOLOGY LA English DT Article ID RAY PHOTOELECTRON-SPECTROSCOPY; GEOTHERMAL ENVIRONMENTS; INTERFACES; CORROSION; SURFACES; STEEL AB Resole-type phenolic polymer coatings were deposited on carbon steel panels, and then were exposed for 15 days fo a simulated geothermal brine with pH 1.6 af 150 degrees 175 degrees and 200 degreesC. The phenolic polymers were hydrothermally oxidized. To comprehensively understand the mechanisms of this oxidative degradation of the coatings, the modern analytical techniques of XPS, contact angle TGA, SEM-EDX, and EIS were used in combination The oxidative degradation of polymer took place in the three-step oxidation routes:first,the bridging methylene linkages in the network polymer structure were replaced by the benzlhydrol-type linkages; second the benzlhydrol-type linkages were transformed into the benzophenone-type linkages; anti finally, the C-C-C linkage in the benzophenone derivative ruptured to form salicylic acid derivatives as the ultimate degradation products. Hydrothermal temperatures of > 175 degreesC promoted the degree of such oxidative degradation, causing the coating surface to become susceptible fo moisture, to absorb more brine, and also to allow corrosive electrolytes to permeate easily. Consequently, iron oxides as the corrosion products from the underlying steel were yielded at a critical interfacial zone between the coating and steel. The excessive growth of iron oxides led to the generation of internal stress-induced cracks in the coating film, thereby resulting in the failure of these corrosion-preventing barriers. C1 Brookhaven Natl Lab, Dept Appl Sci, Div Mat & Chem Sci, Upton, NY 11973 USA. Natl Renewable Energy Lab, Golden, CO 80401 USA. RP Sugama, T (reprint author), Brookhaven Natl Lab, Dept Appl Sci, Div Mat & Chem Sci, Upton, NY 11973 USA. NR 17 TC 3 Z9 3 U1 0 U2 4 PU FEDERATION SOC COATING TECH PI BLUE BELL PA 492 NORRISTOWN ROAD, BLUE BELL, PA 19422 USA SN 0361-8773 J9 J COATING TECHNOL JI J. Coat. Technol. PD JUN PY 2001 VL 73 IS 917 BP 65 EP 71 DI 10.1007/BF02698399 PG 7 WC Chemistry, Applied; Materials Science, Coatings & Films SC Chemistry; Materials Science GA 439UQ UT WOS:000169136300012 ER PT J AU Komatitsch, D Martin, R Tromp, J Taylor, MA Wingate, BA AF Komatitsch, D Martin, R Tromp, J Taylor, MA Wingate, BA TI Wave propagation in 2-D elastic media using a spectral element method with triangles and quadrangles SO JOURNAL OF COMPUTATIONAL ACOUSTICS LA English DT Article; Proceedings Paper CT 4th International Conference on Theoretical and Computational Acoustics (ICTCA) CY MAY, 1999 CL TRIESTE, ITALY ID POLYNOMIAL INTERPOLATION; HETEROGENEOUS MEDIA; REAL FUNCTIONS; SIMULATION; POINTS; INTERFACE; 2D AB We apply a spectral element method based upon a conforming mesh of quadrangles and triangles to the problem of 2-D elastic wave propagation. The method retains the advantages of classical spectral element methods based upon quadrangles only. It makes use of the classical Gauss-Lobatto-Legendre formulation on the quadrangles, while discretization on the triangles is based upon interpolation at the Fekete points. We obtain a global diagonal mass matrix which allows us to keep the explicit structure of classical spectral element solvers. We demonstrate the accuracy and efficiency of the method by comparing results obtained for pure quadrangle meshes with those obtained using mixed quadrangle-triangle and triangle-only meshes. C1 Harvard Univ, Cambridge, MA USA. Inst Mexicano Petr, Mexico City, DF, Mexico. Univ Calif Los Alamos Natl Lab, Los Alamos, NM USA. RP Komatitsch, D (reprint author), CALTECH, Seismol Lab, Pasadena, CA 91125 USA. RI Tromp, Jeroen/B-6185-2015; Komatitsch, Dimitri/E-7153-2012 OI Tromp, Jeroen/0000-0002-2742-8299; Komatitsch, Dimitri/0000-0003-2309-8269 NR 37 TC 58 Z9 63 U1 0 U2 9 PU WORLD SCIENTIFIC PUBL CO PTE LTD PI SINGAPORE PA JOURNAL DEPT PO BOX 128 FARRER ROAD, SINGAPORE 912805, SINGAPORE SN 0218-396X J9 J COMPUT ACOUST JI J. Comput. Acoust. PD JUN PY 2001 VL 9 IS 2 BP 703 EP 718 DI 10.1142/S0218396X01000796 PG 16 WC Acoustics; Mathematics, Interdisciplinary Applications SC Acoustics; Mathematics GA 454MD UT WOS:000169975600028 ER PT J AU Guha, H Saiers, JE Brooks, S Jardine, P Jayachandran, K AF Guha, H Saiers, JE Brooks, S Jardine, P Jayachandran, K TI Chromium transport, oxidation, and adsorption in manganese-coated sand SO JOURNAL OF CONTAMINANT HYDROLOGY LA English DT Article DE solute transport; geochemical models; oxidation; kinetics; chromium ID OXIDE WATER INTERFACE; REACTIVE TRANSPORT; CR(III) OXIDATION; POROUS-MEDIA; SORPTION; SURFACE; MECHANISMS; BIRNESSITE; REDUCTION; DELTA-MNO2 AB We examine how the processes of advection, dispersion, oxidation-reduction, and adsorption combine to affect the transport of chromium through columns packed with pyrolusite (beta -MnO2)-coated sand. We find that beta -MnO2 effectively oxidizes Cr(III) to Cr(VI) and that the extent of oxidation is sensitive to changes in pH, pore water velocity, and influent concentrations of Cr(III). Cr(III) oxidation rates, although initially high, decline well before the supply of beta -MnO2 is depleted, suggesting that a reaction product inhibits the conversion of Cr(III) to Cr(VI). Rate-limited reactions govern the weak adsorption of each chromium species, with Cr(III) adsorption varying directly with pH and Cr(VI) adsorption varying inversely with pH. The breakthrough data on chromium transport can be matched closely by calculations of a simple model that accounts for (1) advective-dispersive transport of Cr(III), Cr(VI), and dissolved oxygen, (2) first-order kinetics adsorption of the reduced and oxidized chromium species. and (3) nonlinear rate-limited oxidation of Cr(III) to Cr(VI). Our work supplements the limited database on the transport of redox-sensitive metals in porous media and provides a means for quantifying the coupled processes that contribute to this transport. (C) 2001 Elsevier Science B.V. All rights reserved. C1 Yale Univ, Sch Environm Studies, New Haven, CT 06511 USA. Florida Int Univ, Hemispher Ctr Environm Technol, Miami, FL 33174 USA. Oak Ridge Natl Lab, Div Environm Sci, Oak Ridge, TN 37831 USA. Florida Int Univ, Dept Environm Studies, Miami, FL 33199 USA. RP Saiers, JE (reprint author), Yale Univ, Sch Environm Studies, 370 Prospect St, New Haven, CT 06511 USA. NR 40 TC 39 Z9 41 U1 1 U2 27 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 JUN PY 2001 VL 49 IS 3-4 BP 311 EP 334 DI 10.1016/S0169-7722(00)00199-6 PG 24 WC Environmental Sciences; Geosciences, Multidisciplinary; Water Resources SC Environmental Sciences & Ecology; Geology; Water Resources GA 434BH UT WOS:000168794900007 PM 11411402 ER PT J AU Kinney, JH Pople, JA Driessen, CKH Breunig, TM Marshall, GW Marshall, SJ AF Kinney, JH Pople, JA Driessen, CKH Breunig, TM Marshall, GW Marshall, SJ TI Intrafibrillar mineral may be absent in dentinogenesis imperfecta type II (DI-II) SO JOURNAL OF DENTAL RESEARCH LA English DT Article DE dentin; dentinogenesis imperfecta; mineralization; small angle scattering; synchroton radiation ID DENTIN MATRIX; COLLAGEN; BONE; ULTRASTRUCTURE; CRYSTALS; TISSUES; MODEL AB High-resolution synchrotron radiation computed tomography (SRCT) and small-angle x-ray scattering (SAXS) were performed on normal and dentinogenesis imperfecta type II (DI-II) teeth. The SRCT showed that the mineral concentration was 33% lower on average in the DI-II dentin with respect to normal dentin. The SAXS spectra from normal dentin exhibited low-angle diffraction peaks at harmonics of 67.6 nm, consistent with nucleation and growth of the apatite phase within gaps in the collagen fibrils (intrafibrillar mineralization). In contrast, the low-angle peaks were almost non-existent in the DI-II dentin. Crystallite thickness was independent of location in both DI-II and normal dentin, although the crystallites were significantly thicker in DI-II dentin (6.8 nm [SD = 0.5] vs. 5.1 run [SD = 0.6]). as determined The shape factor of the crystallites, by SAXS, showed a continuous progression in normal dentin from roughly one-dimensional (needle-like) near the pulp to two-dimensional (plate-like) near the dentin-enamel junction. The crystallites in DI-II dentin, on the other hand, remained needle-like throughout. The above observations are consistent with an absence of intrafibrillar mineral in DI-II dentin. C1 Univ Calif San Francisco, Dept Prevent & Restorat Dent Sci, San Francisco, CA 94143 USA. Stanford Synchrotron Radiat Lab, Stanford, CA 94309 USA. Univ Pretoria, Dept Restorat Dent, ZA-0002 Pretoria, South Africa. RP Kinney, JH (reprint author), Univ Calif San Francisco, Dept Prevent & Restorat Dent Sci, Box 0758,707 Parnassus Ave, San Francisco, CA 94143 USA. FU NIDCR NIH HHS [P01 DE09859] NR 25 TC 31 Z9 32 U1 0 U2 5 PU AMER ASSOC DENTAL RESEARCH PI ALEXANDRIA PA 1619 DUKE ST, ALEXANDRIA, VA 22314 USA SN 0022-0345 J9 J DENT RES JI J. Dent. Res. PD JUN PY 2001 VL 80 IS 6 BP 1555 EP 1559 PG 5 WC Dentistry, Oral Surgery & Medicine SC Dentistry, Oral Surgery & Medicine GA 473EK UT WOS:000171026900015 PM 11499512 ER PT J AU Kevan, SD Rotenberg, E AF Kevan, SD Rotenberg, E TI Many body effects at surfaces and interfaces SO JOURNAL OF ELECTRON SPECTROSCOPY AND RELATED PHENOMENA LA English DT Article DE angle-resolved photoemission; condensed matter; interface physical; surface physics ID ANGLE-RESOLVED PHOTOEMISSION; CHARGE-DENSITY-WAVE; BAND-STRUCTURE; OSCILLATORY INTERACTION; SUPERCONDUCTING STATE; BE(0001) SURFACE; FERMI-SURFACE; W(110); BI2SR2CACU2O8+DELTA; HYDROGEN AB The past two decades have experienced the development of angle-resolved photoemission to the point that it can now provide crucial information on an energy scale that is relevant to many key problems in condensed matter physics. At the same time, our ability to prepare and characterize surfaces, interfaces, and thin films has improved to the extent that many exotic phases can be produced with a high degree of perfection. The combination of these two developments suggests many interesting experiments can be performed that probe the coupling between charge, lattice, and spin degrees of freedom in the context of surface and interface physics. In this paper we briefly review a few groundbreaking experiments that have initiated this effort. We also speculate on future developments in this area. (C) 2001 Elsevier Science B.V. All rights reserved. C1 Univ Oregon, Dept Phys, Eugene, OR 97403 USA. Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. RP Kevan, SD (reprint author), Univ Oregon, Dept Phys, Eugene, OR 97403 USA. EM kevan@darkwing.uoregon.edu RI Rotenberg, Eli/B-3700-2009; Kevan, Stephen/F-6415-2010 OI Rotenberg, Eli/0000-0002-3979-8844; Kevan, Stephen/0000-0002-4621-9142 NR 58 TC 10 Z9 10 U1 0 U2 2 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 JUN PY 2001 VL 117 BP 57 EP 70 DI 10.1016/S0368-2048(01)00245-6 PG 14 WC Spectroscopy SC Spectroscopy GA 448VY UT WOS:000169651700006 ER PT J AU Abanov, A Chubukov, AV Schmalian, J AF Abanov, A Chubukov, AV Schmalian, J TI Fingerprints of spin mediated pairing in cuprates SO JOURNAL OF ELECTRON SPECTROSCOPY AND RELATED PHENOMENA LA English DT Article DE superconductivity; optics; tunneling; ARPES ID HIGH-TEMPERATURE SUPERCONDUCTORS; T-C SUPERCONDUCTORS; NEUTRON-SCATTERING; QUASI-PARTICLE; TUNNELING SPECTROSCOPY; OVERDOPED BI2SR2CACU2O8+DELTA; FLUCTUATION SCATTERING; MAGNETIC EXCITATIONS; CONDUCTIVITY; YBA2CU3O7-DELTA AB We demonstrate that the feedback effect from bosonic excitations on fermions, which in the past allowed one to verify the phononic mechanism of a conventional, s-wave superconductivity, may also allow one to experimentally detect the 'fingerprints' of the pairing mechanism in cuprates. We argue that for spin-mediated d-wave superconductivity, the fermionic spectral function, the density of states, the tunneling conductance through an insulating junction, and the optical conductivity are affected by the interaction with collective spin excitations, which below T-c are propagating, magnon-like quasiparticles with gap Delta (s). We show that the interaction with a propagating spin excitation gives rise to singularities at frequencies Delta + Delta (s) for the spectral function and the density of states, and at 2 Delta + Delta (s) for tunneling and optical conductivities, where Delta is the maximum value of the d-wave gap. We further argue that recent optical measurements also allow one to detect subleading singularities at 4 Delta and 2 Delta + 2 Delta (s). We consider the experimental detection of these singularities as a strong evidence in favor of the magnetic scenario for superconductivity in cuprates. (C) 2001 Elsevier Science B.V. All rights reserved. C1 Univ Wisconsin, Dept Phys, Madison, WI 53706 USA. Iowa State Univ, Dept Phys, Ames, IA 50011 USA. Iowa State Univ, Ames Lab, Ames, IA 50011 USA. RP Abanov, A (reprint author), Univ Wisconsin, Dept Phys, 1150 Univ Ave, Madison, WI 53706 USA. RI Schmalian, Joerg/H-2313-2011 NR 74 TC 39 Z9 39 U1 0 U2 2 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 JUN PY 2001 VL 117 BP 129 EP 151 DI 10.1016/S0368-2048(01)00251-1 PG 23 WC Spectroscopy SC Spectroscopy GA 448VY UT WOS:000169651700011 ER PT J AU Johnson, PD Fedorov, AV Valla, T AF Johnson, PD Fedorov, AV Valla, T TI Photoemission studies of self-energy effects in cuprate superconductors SO JOURNAL OF ELECTRON SPECTROSCOPY AND RELATED PHENOMENA LA English DT Article DE photoemission; superconductivity; self-energy ID ANGLE-RESOLVED PHOTOEMISSION; HIGH-TEMPERATURE SUPERCONDUCTORS; T-C SUPERCONDUCTORS; FERMI-SURFACE; GAP ANISOTROPY; NORMAL-STATE; ELECTRONIC-STRUCTURE; BI2SR2CACU2O8+DELTA; PHASE; ANTIFERROMAGNETS AB Recent instrumentation developments in photoemission are providing new insights into the physics of complex materials. With increased energy and momentum resolution, it has become possible to examine in detail different contributions to the self-energy or inverse lifetime of the photohole created in the photoexcitation process. In studies of a metallic system such as Mo it is possible to isolate and identify the different contributions to the quasi-particle lifetime including electron-electron, electron-phonon and electron-impurity scattering. In contrast, studies of the high T-c superconductor, Bi2Sr2CaCu2O8+delta, show that the material at optimal doping behaves like a non-Fermi liquid rather a Fermi liquid. (C) 2001 Elsevier Science B.V. All rights reserved. C1 Assoc Univ Inc, Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. RP Johnson, PD (reprint author), Assoc Univ Inc, Brookhaven Natl Lab, Dept Phys, POB 5000, Upton, NY 11973 USA. EM pdj@bnl.gov NR 56 TC 12 Z9 12 U1 1 U2 6 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 JUN PY 2001 VL 117 BP 153 EP 164 DI 10.1016/S0368-2048(01)00263-8 PG 12 WC Spectroscopy SC Spectroscopy GA 448VY UT WOS:000169651700012 ER PT J AU Damascelli, A Lu, DH Shen, ZX AF Damascelli, A Lu, DH Shen, ZX TI From Mott insulator to overdoped superconductor: evolution of the electronic structure of cuprates studied by ARPES SO JOURNAL OF ELECTRON SPECTROSCOPY AND RELATED PHENOMENA LA English DT Review DE photoemission; ARPES; electronic structure; cuprates; Mott insulators; high temperature superconductors ID ANGLE-RESOLVED PHOTOEMISSION; HIGH-TEMPERATURE SUPERCONDUCTORS; T-C SUPERCONDUCTORS; QUASI-PARTICLE DISPERSION; COPPER-OXIDE SR2CUO2CL2; SPIN-CHARGE SEPARATION; NARROW ENERGY BANDS; LANDAU-FERMI LIQUID; HUBBARD-MODEL; NORMAL-STATE AB We review our angle-resolved photoemission spectroscopy (ARPES) results on different layered oxide superconductors, and on their insulating parent compounds. The low energy excitations are discussed with emphasis on some of the most recent issues, such as the Fermi surface and remnant Fermi surface, the pseudogap and d-wave-like dispersion, and lastly the signatures in the ARPES spectra of multiple electronic components, many body effects, and the superfluid density. We will focus on systematic changes in the electronic structure which may be relevant to the development of a comprehensive picture for the evolution from Mott insulators to overdoped superconductors. (C) 2001 Elsevier Science B.V. All rights reserved. C1 Stanford Univ, Dept Phys, Stanford, CA 94305 USA. Stanford Univ, Stanford Synchrotron Radiat Lab, Stanford, CA 94305 USA. RP Damascelli, A (reprint author), Stanford Univ, Dept Phys, Stanford, CA 94305 USA. EM damascel@stanford.edu RI damascelli, andrea/P-6329-2014 OI damascelli, andrea/0000-0001-9895-2226 NR 151 TC 37 Z9 37 U1 3 U2 17 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 JUN PY 2001 VL 117 BP 165 EP 187 DI 10.1016/S0368-2048(01)00264-X PG 23 WC Spectroscopy SC Spectroscopy GA 448VY UT WOS:000169651700013 ER PT J AU Arko, AJ Joyce, JJ Moore, DP Sarrao, JL Morales, L Durakiewicz, T Fisk, Z Koelling, DD Olson, CG AF Arko, AJ Joyce, JJ Moore, DP Sarrao, JL Morales, L Durakiewicz, T Fisk, Z Koelling, DD Olson, CG TI Electronic structure of correlated electron materials from photoemission in high-quality single crystals SO JOURNAL OF ELECTRON SPECTROSCOPY AND RELATED PHENOMENA LA English DT Article DE heavy fermion systems; photoelectron spectra; periodic Anderson model; single impurity model ID HEAVY-FERMION SYSTEMS; VALENCE PHASE-TRANSITION; DILUTE MAGNETIC-ALLOYS; LOW-ENERGY EXCITATIONS; LARGE-N EXPANSION; TEMPERATURE-DEPENDENCE; KONDO RESONANCE; PHOTOELECTRON-SPECTROSCOPY; PHYSICAL-PROPERTIES; SPECTRAL-FUNCTION AB Much of our understanding of heavy fermion systems over the past two decades has been based on the single impurity model and its approximate solutions. We show with numerous examples of photoelectron spectra, especially with YbInCu4, that this model is not applicable to stoichiometric heavy fermion compounds. There is overwhelming evidence that the correct description of heavy fermions must include very narrow, hybridized bands which exist already at temperatures far above the thermodynamically determined Kondo temperature, and that these bands are relatively temperature independent. Some form of the periodic Anderson model (PAM) is needed, one which results in very narrow renormalized LDA bands. We compare our data to one form of the PAM. (C) 2001 Elsevier Science B.V. All rights reserved. C1 Univ Calif Los Alamos Natl Lab, MST10 Grp, Los Alamos, NM 87545 USA. Argonne Natl Lab, Argonne, IL 60439 USA. Iowa State Univ, Ames, IA USA. RP Arko, AJ (reprint author), Univ Calif Los Alamos Natl Lab, MST10 Grp, Mail Stop K764, Los Alamos, NM 87545 USA. OI Durakiewicz, Tomasz/0000-0002-1980-1874 NR 66 TC 17 Z9 17 U1 0 U2 3 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 JUN PY 2001 VL 117 BP 323 EP 345 DI 10.1016/S0368-2048(01)00256-0 PG 23 WC Spectroscopy SC Spectroscopy GA 448VY UT WOS:000169651700023 ER PT J AU Denlinger, JD Gweon, GH Allen, JW Olson, CG Maple, MB Sarrao, JL Armstrong, PE Fisk, Z Yamagami, H AF Denlinger, JD Gweon, GH Allen, JW Olson, CG Maple, MB Sarrao, JL Armstrong, PE Fisk, Z Yamagami, H TI Comparative study of the electronic structure of XRu2Si2: probing the Anderson lattice SO JOURNAL OF ELECTRON SPECTROSCOPY AND RELATED PHENOMENA LA English DT Article DE angle resolved photoemission; f-electron; heavy fermion; Anderson lattice ID RESOLVED PHOTOEMISSION SPECTROSCOPY; HEAVY-FERMION SYSTEMS; SINGLE-IMPURITY MODEL; BAND-STRUCTURE; CE COMPOUNDS; SURFACE; URU2SI2; KONDO; CERU2SI2; STATES AB dThe k-resolved single particle excitations, as determined by angle-resolved photoemission spectroscopy (ARPES), are compared and contrasted for, LaRu2Si2, CeRu2Si2, ThRu2Si2, and URu2Si2, isostructural layered compounds with differing nominal f-occupations of f(0), f(1), f(0), and f(2), respectively. ARPES measurements include 4d and Sd-edge resonant photoemission to distinguish S-character and Fermi-energy intensity mapping of Fermi surface contours. Comparison to RLAPW band structure calculations shows very good agreement of the d-band structure away from E-j. Discrepancies in the near E-j region highlight k-dependent effects of f-correlation and f-d hybridization. Approximately equal dimensions of Fermi contours for X = (La, Ce) suggest the exclusion of 4f electrons from the CeRu2Si2 Fermi surface at temperatures far above the Kondo temperature. High-resolution spectra for X= (Ce, U) allow comparison of f-d mixing to predictions of the Anderson lattice model. Published by Elsevier Science B.V. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Adv Light Source, Berkeley, CA 94720 USA. Univ Michigan, Randall Lab, Ann Arbor, MI 48109 USA. Iowa State Univ Sci & Technol, Ames Lab, Ames, IA 50011 USA. Univ Calif San Diego, Dept Phys, La Jolla, CA 92093 USA. Univ Calif San Diego, Inst Pure & Appl Phys Sci, La Jolla, CA 92093 USA. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Florida State Univ, Dept Phys, Tallahassee, FL 32306 USA. Florida State Univ, Natl High Magnet Field Lab, Tallahassee, FL 32306 USA. Kyoto Sangyo Univ, Kyoto 603, Japan. RP Denlinger, JD (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Adv Light Source, Berkeley, CA 94720 USA. NR 54 TC 82 Z9 82 U1 1 U2 24 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 JUN PY 2001 VL 117 BP 347 EP 369 DI 10.1016/S0368-2048(01)00257-2 PG 23 WC Spectroscopy SC Spectroscopy GA 448VY UT WOS:000169651700024 ER PT J AU Gweon, GH Denlinger, JD Allen, JW Claessen, R Olson, CG Hochst, H Marcus, J Schlenker, C Schneemeyer, LF AF Gweon, GH Denlinger, JD Allen, JW Claessen, R Olson, CG Hochst, H Marcus, J Schlenker, C Schneemeyer, LF TI ARPES line shapes in FL and non-FL quasi-low-dimensional inorganic metals SO JOURNAL OF ELECTRON SPECTROSCOPY AND RELATED PHENOMENA LA English DT Article DE angle resolved photoemission line shape; Fermi liquid; Luttinger liquid; charge density wave ID ANGLE-RESOLVED PHOTOEMISSION; PURPLE BRONZE LI0.9MO6O17; BAND ELECTRONIC-STRUCTURE; TOMONAGA-LUTTINGER MODEL; FERMI-LIQUID BEHAVIOR; T-C SUPERCONDUCTORS; PEIERLS TRANSITION; BLUE BRONZE; SPECTRAL-FUNCTION; NORMAL-STATE AB Quasi-low-dimensional (quasi-low-D) inorganic materials are not only ideally suited for angle resolved photoemission spectroscopy (ARPES) but also they offer a rich ground for studying key concepts for the emerging paradigm of non-Fermi liquid (non-FL) physics. In this article, we discuss the ARPES technique applied to three quasi-low-D inorganic metals: a paradigm Fermi liquid (ni) material TiTe2, a well-known quasi-1D charge density wave (CDW) material K0.3MoO3 and a quasi-1D non-CDW material Li0.9Mo6O17. With TiTe2, we establish that a many body theoretical interpretation of the ARPES line shape is possible. We also address the fundamental question of how to accurately determine the k(F) value from ARPES. Both K0.3MoO3 and Li0.9Mo6O17 show quasi-1D electronic structures with non-FL line shapes, A CDW gap opening is observed for K0.3MoO3, whereas no gap is observed for Li0.9Mo6O17. We show, however, that the standard CDW theory, even with strong fluctuations, is not sufficient to describe the non-FL line shapes of K0.3MoO3. We argue that a Luttinger liquid (LL) model is relevant for both bronzes, but also point out difficulties encountered in comparing data with theory. We interpret this situation to mean that a more complete and realistic theory is necessary to understand these data. (C) 2001 Elsevier Science B.V. All rights reserved. C1 Univ Michigan, Randall Lab Phys, Ann Arbor, MI 48109 USA. Univ Augsburg, D-86135 Augsburg, Germany. Iowa State Univ Sci & Technol, Ames Lab, Ames, IA 50011 USA. Univ Wisconsin, Ctr Synchrotron Radiat, Stoughton, WI 53589 USA. CNRS, Etud Proprietes Elect Solides Lab, F-38042 Grenoble, France. Bell Labs, Lucent Technol, Murray Hill, NJ 07974 USA. RP Gweon, GH (reprint author), Univ Michigan, Randall Lab Phys, Ann Arbor, MI 48109 USA. RI Claessen, Ralph/A-2045-2017 OI Claessen, Ralph/0000-0003-3682-6325 NR 85 TC 58 Z9 58 U1 4 U2 26 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 JUN PY 2001 VL 117 BP 481 EP 502 DI 10.1016/S0368-2048(01)00271-7 PG 22 WC Spectroscopy SC Spectroscopy GA 448VY UT WOS:000169651700032 ER PT J AU Kim, C AF Kim, C TI Spin-charge separation in 1D Mott-insulators and related systems SO JOURNAL OF ELECTRON SPECTROSCOPY AND RELATED PHENOMENA LA English DT Article DE spin-charge separation; ARPES; electronic structure; Mott-insulator ID ANGLE-RESOLVED PHOTOEMISSION; HEISENBERG ANTIFERROMAGNETIC CHAIN; HIGH-TEMPERATURE SUPERCONDUCTORS; COPPER-OXIDE SR2CUO2CL2; MOMENTUM DISTRIBUTION; OPTICAL NONLINEARITY; HUBBARD INSULATOR; STATE; EXCITATIONS; SPECTRA AB This article reviews recent developments in experimental evidences of spin-charge separation in one dimensional (1D) Mott insulators and related systems, focusing on angle resolved photoemission spectroscopy (ARPES) results. The ARPES spectra from ideal 1D Cu-O chain compounds SrCuO2 and Sr2CuO3 show broad features between k = 0 and pi /2 while only one feature is observed between pi /2 and rr. Numerical results based on the t - J model qualitatively explain many important aspects of the observed features, strongly suggesting the excited photo hole decays into spin and charge excitations. Supporting evidences from experiments with other techniques as well as different materials are reviewed. Finally, related issues in high temperature superconductivity are discussed. (C) 2001 Elsevier Science B.V. All rights reserved. C1 Stanford Synchrotron Radiat Lab, Stanford, CA 94309 USA. RP Kim, C (reprint author), Stanford Synchrotron Radiat Lab, POB 4349 MS 99, Stanford, CA 94309 USA. NR 44 TC 7 Z9 7 U1 0 U2 2 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 JUN PY 2001 VL 117 BP 503 EP 515 DI 10.1016/S0368-2048(01)00272-9 PG 13 WC Spectroscopy SC Spectroscopy GA 448VY UT WOS:000169651700033 ER PT J AU Smith, KE Xue, JY Duda, L Federov, A Johnson, PD Hulbert, SL McCarroll, W Greenblatt, M AF Smith, KE Xue, JY Duda, L Federov, A Johnson, PD Hulbert, SL McCarroll, W Greenblatt, M TI Recent high resolution photoemission studies of electronic structure in quasi-one-dimensional conductors SO JOURNAL OF ELECTRON SPECTROSCOPY AND RELATED PHENOMENA LA English DT Article DE one-dimensional metals; photoemission spectroscopy; charge density waves; neutron scattering; Fermi surfaces ID CHARGE-SPIN SEPARATION; FERMI-SURFACE; LUTTINGER-LIQUID; SPECTRAL PROPERTIES; MOLYBDENUM BRONZES; BLUE BRONZE; LI0.9MO6O17; DENSITY; K0.3MOO3; MODEL AB The electronic structure near the Fermi level of K0.3MoO3 and Li0.9Mo6O17, two prototypical quasi-one-dimensiona1 (1D) conductors, has been studied using very high resolution angle-resolved photoemission spectroscopy. Our results differ from earlier lower resolution studies. For Li0.9Mo6O17 we clearly observe a quasi-1D state dispersing through the Fermi level (E-F) and the opening up of a gap at as the sample is cooled through a bulk metal to non-metal transition at 24 K. For K0.3MoO3 we clearly observe two quasi-1D bands cross E-F, and measured a temperature dependence to the Fermi surface nesting vector that correlates well with neutron-scattering measurements of the charge density wave vector. (C) 2001 Elsevier Science B.V. All rights reserved. C1 Boston Univ, Dept Phys, Boston, MA 02215 USA. Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. Brookhaven Natl Lab, Natl Synchrotron Light Source, Upton, NY 11973 USA. Rutgers State Univ, Dept Chem, New Brunswick, NJ 08903 USA. RP Smith, KE (reprint author), Boston Univ, Dept Phys, 590 Commonwealth Ave, Boston, MA 02215 USA. NR 41 TC 2 Z9 2 U1 0 U2 2 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 JUN PY 2001 VL 117 BP 517 EP 526 DI 10.1016/S0368-2048(01)00273-0 PG 10 WC Spectroscopy SC Spectroscopy GA 448VY UT WOS:000169651700034 ER PT J AU Cui, Y Wright, GW Ma, X Chattopadhyay, K James, RB Burger, A AF Cui, Y Wright, GW Ma, X Chattopadhyay, K James, RB Burger, A TI DC photoconductivity study of semi-insulating Cd1-xZnxTe crystals SO JOURNAL OF ELECTRONIC MATERIALS LA English DT Article; Proceedings Paper CT 19th US Workshop on the Physics and Chemistry of II-VI Materials CY OCT 30-NOV 02, 2000 CL ALBUQUERQUE, NEW MEXICO SP USA SMDC, USA, Res Lab, Off Naval Res, Air Force Res Lab, Minerals, Metals & Materials Soc DE DC photocurrent; surface recombination; CZT; detector performance; gamma-ray detectors ID CDZNTE STRIP DETECTORS; RADIATION DETECTORS; SURFACE LEAKAGE; PASSIVATION; RECOMBINATION; SPECTROMETERS; FABRICATION; CONTACTS; SEARCH AB Room temperature direct current (DC) photocurrents were measured for detector grade Cd1-xZnxTe (CZT) crystals in the spectral range of 400-1000 nm as a function of light intensity and voltage. The photocurrent data were analyzed and fit to a theoretical model to extract the electrical transport properties for high-resistivity detector grade CZT material. Using the DC photocurrent measurements, the mobility-lifetime (mu tau) products and the surface recombination velocities for both electrons and holes were measured. For this study the CZT detectors had Au contacts, and the surfaces were treated in a standard 5% bromine in methanol etching solution. The correlation of the DC photocurrent measurements and detector performance is also reported. C1 Fisk Univ, Ctr Photon Mat & Devices, Nashville, TN 37208 USA. Sandia Natl Labs, Livermore, CA 94550 USA. RP Cui, Y (reprint author), Fisk Univ, Ctr Photon Mat & Devices, Nashville, TN 37208 USA. NR 17 TC 20 Z9 20 U1 1 U2 5 PU MINERALS METALS MATERIALS SOC PI WARRENDALE PA 184 THORN HILL RD, WARRENDALE, PA 15086 USA SN 0361-5235 J9 J ELECTRON MATER JI J. Electron. Mater. PD JUN PY 2001 VL 30 IS 6 BP 774 EP 778 DI 10.1007/BF02665871 PG 5 WC Engineering, Electrical & Electronic; Materials Science, Multidisciplinary; Physics, Applied SC Engineering; Materials Science; Physics GA 445EE UT WOS:000169444500038 ER PT J AU Thio, YCF Knapp, CE Kirkpatrick, RC Siemon, RE Turchi, PJ AF Thio, YCF Knapp, CE Kirkpatrick, RC Siemon, RE Turchi, PJ TI A physics exploratory experiment on plasma liner formation SO JOURNAL OF FUSION ENERGY LA English DT Article DE magnetized target fusion; plasma liner; plasma jets; plasma acceleration; plasma gun ID FUSION AB Momentum flux for imploding a target plasma in magnetized target fusion (MTF) may be delivered by an array of plasma guns launching plasma jets that would merge to form an imploding plasma shell (liner). In this paper, we examine what would be a worthwhile experiment to explore the dynamics of merging plasma jets to form a plasma liner as a first step in establishing an experimental database for plasma-jets-driven magnetized target fusion (PJETS-MTF). Using past experience in fusion energy research as a model, we envisage a four-phase program to advance the art of PJETS-MTF to fusion breakeven (Q similar to 1). The experiment (PLX) described in this paper serves as Phase 1 of this four-phase program. The logic underlying the selection of the experimental parameters is presented. The experiment consists of using 12 plasma guns arranged in a circle, launching plasma jets toward the center of a vacuum chamber. The velocity of the plasma jets chosen is 200 km/s, and each jet is to carry a mass of 0.2 mg to 0.4 mg. A candidate plasma accelerator for launching these jets consists of a coaxial plasma gun of the Marshall type. C1 NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA. Los Alamos Natl Lab, Los Alamos, NM 87545 USA. USAF, Res Lab, Kirtland AFB, NM 87185 USA. RP Thio, YCF (reprint author), NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA. RI Thio, Yong Chia/G-5442-2014 OI Thio, Yong Chia/0000-0003-3615-643X NR 24 TC 40 Z9 40 U1 1 U2 9 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 JUN PY 2001 VL 20 IS 1-2 BP 1 EP 11 AR UNSP 0164-0313/01/0600-001/0 DI 10.1023/A:1019813528507 PG 11 WC Nuclear Science & Technology SC Nuclear Science & Technology GA 585TW UT WOS:000177541500001 ER PT J AU Reyes, S Latkowski, JF Sanz, J del Rio, JG AF Reyes, S Latkowski, JF Sanz, J del Rio, JG TI Safety assessment for inertial fusion energy power plants: Methodology and application to the analysis of the HYLIFE-II and SOMBRERO conceptual designs SO JOURNAL OF FUSION ENERGY LA English DT Article DE inertial fusion energy; safety analysis ID HEAVY-ION; DRIVEN; TARGET; IFE AB Although the safety and environmental (S & E) characteristics of fusion energy have long been emphasized, these benefits are not automatically achieved. To maximize the potential S & E attractiveness of the inertial fusion energy (IFE), analyses must be performed early in the designs so that lessons can be learned and intelligent decisions made. In this work we have introduced for the first time heat transfer and thermal-hydraulics calculations as part of a state-of-the-art set of codes and libraries in order to establish an updated methodology for IFE safety analysis. We have focused our efforts primarily on two IFE power plant conceptual designs: HYLIFE-II and SOMBRERO. To some degree, these designs represent the extremes in IFE power plant designs. Also, a preliminary safety assessment has been performed for a generic target fabrication facility producing various types of targets and using various production techniques. Although this study cannot address all issues and hazards posed by an IFE power plant, it advances our understanding of radiological safety of such facilities. This will enable better comparisons between IFE designs and competing technologies from the safety point of view. C1 Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. Univ Nacl Educ Distancia, Dpto Ingn Energet, Madrid, Spain. ETS Ingn Ind, Inst Fus Nucl, Madrid, Spain. RP Reyes, S (reprint author), Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. NR 51 TC 3 Z9 3 U1 0 U2 2 PU SPRINGER PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 0164-0313 J9 J FUSION ENERG JI J. Fusion Energy PD JUN PY 2001 VL 20 IS 1-2 BP 23 EP 44 AR UNSP 0164-0313/01/0600-0023/0 DI 10.1023/A:1019814413486 PG 22 WC Nuclear Science & Technology SC Nuclear Science & Technology GA 585TW UT WOS:000177541500002 ER PT J AU Sanbonmatsu, KY Newman, DL Goldman, MV AF Sanbonmatsu, KY Newman, DL Goldman, MV TI Quasi-linear Zakharov simulations of Langmuir turbulence at rocket altitudes in the auroral ionosphere SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID ALIGNED ELECTRON-FLUXES; WAVE-WAVE INTERACTIONS; PARAMETRIC-INSTABILITIES; PARTICLE; FREJA; COLLAPSE; GROWTH; BURSTS; DRIVEN AB A quasi-linear Zakharov simulation model has been constructed to study intense Langmuir waves and precipitating field-aligned electrons observed in the auroral ionosphere at altitudes below 1000 km. This self-consistent model couples the magnetized Zakharov equations to a modified quasi-linear diffusion equation, which includes an advective term describing electrons streaming into the simulation region. Two-dimensional beam-driven simulations demonstrate that for the parameters of the auroral ionosphere below altitudes of 1000 km, Langmuir wave-wave and wave-particle interactions occur on similar timescales. The resulting reduced electron distribution has multiple shoulders and is a result of a balance between quasi-linear beam-flattening, wave-wave instabilities and beam replenishment due to streaming electrons. C1 Univ Calif Los Alamos Natl Lab, Appl Theoret & Computat Div, Los Alamos, NM 87545 USA. Univ Colorado, Ctr Integrated Plasma Studies, Boulder, CO 80309 USA. RP Sanbonmatsu, KY (reprint author), Univ Calif Los Alamos Natl Lab, Appl Theoret & Computat Div, MS B259, Los Alamos, NM 87545 USA. NR 32 TC 3 Z9 3 U1 1 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 JUN 1 PY 2001 VL 106 IS A6 BP 10519 EP 10535 DI 10.1029/2000JA000270 PG 17 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 435WP UT WOS:000168905400006 ER PT J AU Intriligator, DS Jokipii, JR Horbury, TS Intriligator, JM Forsyth, RJ Kunow, H Wibberenz, G Gosling, JT AF Intriligator, DS Jokipii, JR Horbury, TS Intriligator, JM Forsyth, RJ Kunow, H Wibberenz, G Gosling, JT TI Processes associated with particle transport in corotating interaction regions and near stream interfaces SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID PLANAR MAGNETIC-STRUCTURES; SOLAR-WIND; ENERGETIC IONS; ULYSSES; EVOLUTION; DIFFUSION; CIRS AB Pioneer and Ulysses observations of energetic particles and solar wind plasma and magnetic fields are analyzed to study particle transport in corotating interaction regions (CIRs) and near stream interfaces (SIs). Energetic particle diffusion with a lowered coefficient near the SIs as compared with the free solar wind may account for the energetic particle profiles in CIRs and for the modulation of Jovian electrons. Our analyses include examination of the magnetic power and variances perpendicular and parallel to the magnetic field for a range of wave numbers and for a range of conditions within two CIRs. Since the magnetic field immediately on either side of a SI, but near it, is not connected to either the forward shock or reverse shock, it is the cross-field motion of the energetic particles that is relevant. Since the cross-field transport is thought to be related to field line mixing, or random walk, we examined magnetic field fluctuations normal to the average field to determine whether any signature of reduced perpendicular particle transport could be found. Evidence consistent with reduced particle transport near the SI was indeed found when we examined time series of the 1-min averages of the magnetic field components. A planar magnetic structure was associated with the trailing unshocked layer following the SIs (i.e., SI to SI + 12 hours) and also with the entire CIRs, but it was not present in the free solar wind. We have quantitatively examined the effects of shear and compression on particle transport and conclude that the effects of shear and compression reduce particle transport in CIRs and in the vicinity of SIs. C1 Carmel Res Ctr, Space Plasma Lab, Santa Monica, CA 90406 USA. Univ London Imperial Coll Sci Technol & Med, Blackett Lab, London SW7 2BZ, England. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Univ Arizona, Dept Planetary Sci, Tucson, AZ 85721 USA. Univ Kiel, Inst Expt & Angew Phys, D-24118 Kiel, Germany. RP Intriligator, DS (reprint author), Carmel Res Ctr, Space Plasma Lab, POB 1732, Santa Monica, CA 90406 USA. NR 17 TC 19 Z9 19 U1 0 U2 0 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 JUN 1 PY 2001 VL 106 IS A6 BP 10625 EP 10634 DI 10.1029/2000JA000070 PG 10 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 435WP UT WOS:000168905400013 ER PT J AU Gary, SP Yin, L Winske, D Ofman, L AF Gary, SP Yin, L Winske, D Ofman, L TI Electromagnetic heavy ion cyclotron instability: Anisotropy constraint in the solar corona SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID TEMPERATURE ANISOTROPY; INVERSE CORRELATION; MAGNETOSHEATH; WIND; PROTON; MODEL; WAVES; ACCELERATION; RESONANCE; DRIVEN AB The electromagnetic proton cyclotron anisotropy instability is driven by T-perpendicular top/T-parallel top > 1 where p represents protons and the directional subscripts denote directions relative to the background magnetic field. Fluctuating field growth leads to wave-particle scattering, which in turn imposes an upper bound on the anisotropy of the form T-perpendicular top/T-parallel top - 1 = S-p/beta (alphap)(parallel top),where beta (parallel top) equivalent to 8 pin(p)k(B)T(parallel top)/B-0(2), and the fitting parameters S-p less than or similar to 1 and alpha (p) similar or equal to 0.4 Recent SOHO observations indicate that minority heavy ions are substantially hotter and more anisotropic than protons in the solar corona. Here linear theory and hybrid simulations have been carried out in a model of a homogeneous, magnetized, collisionless plasma with anisotropic minority oxygen ions (denoted by subscript O). These calculations show that the electromagnetic oxygen ion cyclotron anisotropy instability also leads to wave-particle scattering, which constrains that anisotropy by the form T-perpendicular toO/T-parallel toO - 1 = S-O/[(m(p)/m(O))<()over bar>(parallel toO)](alphaO) where <()over bar>(parallel toO) equivalent to 8 pin(e)k(B)T(parallel toO)/B-o(2), S-O similar to 10 and alpha (O) similar to 0.4. This constraint should be observable in the solar corona. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Gary, SP (reprint author), Univ Calif Los Alamos Natl Lab, MS D466, Los Alamos, NM 87545 USA. NR 46 TC 32 Z9 32 U1 0 U2 2 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 JUN 1 PY 2001 VL 106 IS A6 BP 10715 EP 10722 DI 10.1029/2000JA000406 PG 8 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 435WP UT WOS:000168905400021 ER PT J AU Yin, L Winske, D Gary, SP Birn, J AF Yin, L Winske, D Gary, SP Birn, J TI Hybrid and Hall-MHD simulations of collisionless reconnection: Dynamics of the electron pressure tensor SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID MAGNETIC RECONNECTION; MAGNETOTAIL RECONNECTION; ION DYNAMICS; CURRENT SHEETS; INSTABILITIES; DISSIPATION; PLASMAS; LAYER; FIELD AB In this study we compare the results of two-dimensional hybrid (particle ions, massless fluid electrons) and Hall-MHD simulations of collisionless reconnection in a thin current sheet. Both calculations include the full electron pressure tenser (instead of a localized resistivity) in the generalized Ohm's law to initiate reconnection, and in both an initial perturbation to the Harris equilibrium is applied. As in the recent Geospace Environment Modeling (GEM) reconnection challenge studies, we find overall agreement between the two calculations in both the reconnection rate and the global configuration. Results of this study show that in addition to providing the reconnection electric field at the X point the divergence of the electron pressure tenser leads to in-plane electric fields that exert drag forces on the ions as they enter and exit the near-X-point region. The in-plane electric fields are enhanced in regions of small transverse scale along the edge of the sheet, and the resulting narrow electron current layers are demonstrated clearly. The possibility of improving magnetotail reconnection models by embedding a Hall-MHD calculation using the electron pressure tenser model inside a large-scale MHD simulation is suggested. C1 Univ Calif Los Alamos Natl Lab, Div Appl Phys, Los Alamos, NM 87544 USA. Univ Calif Los Alamos Natl Lab, Los Alamos, NM USA. RP Yin, L (reprint author), Univ Calif Los Alamos Natl Lab, Div Appl Phys, Los Alamos, NM 87544 USA. NR 38 TC 31 Z9 31 U1 0 U2 2 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 JUN 1 PY 2001 VL 106 IS A6 BP 10761 EP 10775 DI 10.1029/2000JA000398 PG 15 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 435WP UT WOS:000168905400025 ER PT J AU McAdams, KL Reeves, GD Friedel, RHW Cayton, TE AF McAdams, KL Reeves, GD Friedel, RHW Cayton, TE TI Multisatellite comparisons of the radiation belt response to the Geospace Environment Modeling (GEM) magnetic storms SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID EARTHS INNER MAGNETOSPHERE; ELECTRON-SCATTERING LOSS; RELATIVISTIC ELECTRONS; SOLAR-WIND; ACCELERATION; DIFFUSION; PARTICLE; CLOUD AB We present a compilation of observations of relativistic radiation belt electrons during the four Geospace Environment Modeling (GEM) storms from instruments on 10 separate spacecraft. While these four magnetic storms have very different solar wind and magnetospheric conditions, there are several characteristics of the relativistic electron response which are applicable to all four storms. We find that although the evolution of the spectral shape of the electrons at a specific L shell does not vary from storm to storm, the evolution is very different at L = 4.2 and L = 6.6. Calculations of the phase space density (PSD) show that the evolution of the PSD depends on both radial position and the value of the first adiabatic invariant. The evolution of the greater than 1-MeV electron flux at L = 4.2 and L = 6.6 for the four storms is consistent with the findings of Reeves et al. [1998c]. The flux at L = 4.2 peaks quickly after the storm (12 hours), while the fluxes at geosynchronous altitudes take several days to rise. We suggest that the common characteristics identified in the four storms that are the subject of this paper can provide a useful basis for comparisons with other storms and for development of a more complete theoretical description of relativistic electron events in general. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP McAdams, KL (reprint author), Univ Calif Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. RI Friedel, Reiner/D-1410-2012; Reeves, Geoffrey/E-8101-2011 OI Friedel, Reiner/0000-0002-5228-0281; Reeves, Geoffrey/0000-0002-7985-8098 NR 36 TC 24 Z9 24 U1 0 U2 0 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 JUN 1 PY 2001 VL 106 IS A6 BP 10869 EP 10882 DI 10.1029/2000JA000248 PG 14 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 435WP UT WOS:000168905400033 ER PT J AU Liemohn, MW Kozyra, JU Thomsen, MF Roeder, JL Lu, G Borovsky, JE Cayton, TE AF Liemohn, MW Kozyra, JU Thomsen, MF Roeder, JL Lu, G Borovsky, JE Cayton, TE TI Dominant role of the asymmetric ring current in producing the stormtime Dst SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID MAGNETOSPHERIC ELECTRIC-FIELDS; INTERPLANETARY MAGNETIC-FIELD; CENTRAL PLASMA SHEET; SOLAR-WIND CONTROL; GEOSYNCHRONOUS ORBIT; ION COMPOSITION; GEOMAGNETIC STORMS; CURRENT EVOLUTION; DEPENDENT MODEL; FEBRUARY 1986 AB Three storms are examined to determine the contribution to the Dst* index from the symmetric and asymmetric (partial) components of the ring current. The storms (September 24-25, 1998, October 18-19, 1998, and May 14-15, 1997) all have a similar solar wind trigger (an initial shock followed by a coronal mass ejection with southward interplanetary magnetic field) and placement in the solar cycle (rising phase). The near-Earth ion distribution function is simulated for each storm using a kinetic transport model. The use of a McIlwain magnetospheric electric field description improves the simulation results over the Volland-Stern field used previously. It is found that most of the main phase magnetic field depression is due to the asymmetric component of the ring current (greater than or equal to 80% at the Dst* minimum for the three storms). Note that this is a minimum asymmetric ring current contribution, because the closed-trajectory ions may also be spatially asymmetric. Ions in the partial ring current make one pass through the inner magnetosphere on open drift paths that intersect the dayside magnetopause. Changes in the density of the inner plasma sheet are transmitted directly along these open drift paths. For a steady convection field, an increase in the source population produces a decrease (more intense perturbation) in Dst*, while a decrease produces a Dst* recovery. As the storm recovery proceeds, a decrease in the electric field results in a conversion of open to closed drift paths, forming a trapped, symmetric ring current that dominates Dst*. The mostly H+ composition of the ring current for all three storms rules out the possibility of differential charge exchange being the cause of the fast and slow decay timescales, confirming that outflow is the main loss of ring current-generated Dst* during the early phase decay. The slow decay timescale in the late recovery, however, is dominated by charge exchange with the hydrogen geocorona. The symmetric-asymmetric ring current is also placed in the context of the solar wind and plasma sheet drivers. C1 Univ Michigan, Space Phys Res Lab, Ann Arbor, MI 48109 USA. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Aerospace Corp, El Segundo, CA 90245 USA. Natl Ctr Atmospher Res, High Altitude Observ, Boulder, CO 80307 USA. RP Liemohn, MW (reprint author), Univ Michigan, Space Phys Res Lab, 2455 Hayward St, Ann Arbor, MI 48109 USA. RI Lu, Gang/A-6669-2011; Liemohn, Michael/H-8703-2012 OI Liemohn, Michael/0000-0002-7039-2631 NR 92 TC 209 Z9 211 U1 1 U2 6 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 JUN 1 PY 2001 VL 106 IS A6 BP 10883 EP 10904 DI 10.1029/2000JA000326 PG 22 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 435WP UT WOS:000168905400034 ER PT J AU Idachaba, MA Nyavor, K Egiebor, NO Rogers, RD AF Idachaba, MA Nyavor, K Egiebor, NO Rogers, RD TI A refinement of the biofilm formation method for waste forms stability evaluation SO JOURNAL OF HAZARDOUS MATERIALS LA English DT Article DE biofilm; Thiobacillus thiooxidans; waste forms; stabilization/solidification; leaching AB A refinement of the biofilm formation method for waste form stability evaluation was carried out in this study. Refinement of the biofilm formation method became necessary because of the reduced contrast in degradation between control and experimental samples. The reduction in contrast was occasioned by the long duration of exposure (12 days) of the control samples to sterile medium of low pH in the first stage. Results of evaluation carried out reveal that the duration of the first stage of the biofilm formation method can be reduced to 24 h, with substantial increase in the contrast between degradations experienced by control and experimental samples. Reduction of the first stage can be done without compromising the efficiency of the inoculation process, which the longer duration of the first stage was originally intended to ensure. A doubt as to actual formation of biofilms on experimental samples, resulting from the use of non-sterile tubings and glass wares in the second stage, was also addressed in this study. Results reveal that substantial attachment of microbes occur on the surfaces of experimental samples in the first stage, thus any supply of microbes via the tubings and glass wares in the second stage is only additional and inconsequential. (C) 2001 Published by Elsevier Science B.V. All rights reserved. C1 Tuskegee Univ, Dept Chem Engn, Environm Engn Program, Tuskegee, AL 36088 USA. EG&G Idaho Inc, Idaho Natl Engn & Environm Lab, Idaho Falls, ID 83415 USA. RP Idachaba, MA (reprint author), Tuskegee Univ, Dept Chem Engn, Environm Engn Program, Tuskegee, AL 36088 USA. NR 6 TC 6 Z9 6 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0304-3894 J9 J HAZARD MATER JI J. Hazard. Mater. PD JUN 1 PY 2001 VL 84 IS 1 BP 95 EP 106 DI 10.1016/S0304-3894(01)00200-X PG 12 WC Engineering, Environmental; Engineering, Civil; Environmental Sciences SC Engineering; Environmental Sciences & Ecology GA 439LU UT WOS:000169119000007 PM 11376887 ER PT J AU Chang, SL Lottes, SA Zhou, CQ Bowman, BJ Petrick, M AF Chang, SL Lottes, SA Zhou, CQ Bowman, BJ Petrick, M TI Numerical study of spray injection effects on the heat transfer and product yields of FCC riser reactors SO JOURNAL OF HEAT TRANSFER-TRANSACTIONS OF THE ASME LA English DT Article DE computational; CFD; FCC; heat transfer; modeling; multi-phase; sprays ID CATALYTIC CRACKING; FLOW; MODELS AB A three-phase reacting flow computational fluid dynamics (CFD) computer code was used to study the major effects of spray injection parameters on mixing, heat transfer, vaporization, and reaction product yields in fluidized catalytic cracking (FCC) riser reactors. The CFD code was validated using experimental or field data. A number of computations were performed with varied injection parameters, including injection velocity, injection angle, and droplet size. Local optimum operating windows for spray injection parameters were identified, and the sensitivity of local optima to variation in spray parameters was also investigated. C1 Argonne Natl Lab, Argonne, IL 60439 USA. Purdue Univ Calumet, Hammond, IN 46323 USA. RP Chang, SL (reprint author), Argonne Natl Lab, 9700 S Cass Ave, Argonne, IL 60439 USA. NR 24 TC 14 Z9 14 U1 0 U2 2 PU ASME-AMER SOC MECHANICAL ENG PI NEW YORK PA THREE PARK AVE, NEW YORK, NY 10016-5990 USA SN 0022-1481 J9 J HEAT TRANS-T ASME JI J. Heat Transf.-Trans. ASME PD JUN PY 2001 VL 123 IS 3 BP 544 EP 555 DI 10.1115/1.1370509 PG 12 WC Thermodynamics; Engineering, Mechanical SC Thermodynamics; Engineering GA 442JL UT WOS:000169281400016 ER PT J AU Brace, DM Cerchiai, BL Pasqua, AF Varadarajan, U Zumino, B AF Brace, DM Cerchiai, BL Pasqua, AF Varadarajan, U Zumino, B TI A cohomological approach to the non-abelian Seiberg-Witten map SO JOURNAL OF HIGH ENERGY PHYSICS LA English DT Article DE string duality; brane dynamics in gauge theories; gauge symmetry; non-commutative geometry AB We present a cohomological method for obtaining the non-abelian Seiberg-Witten map for any gauge group and to any order in theta. By introducing a ghost field, we are able to express the equations defining the Seiberg-Witten map through a coboundary operator, so that they can be solved by constructing a corresponding homotopy operator. C1 Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Theoret Phys Grp, Berkeley, CA 94720 USA. RP Brace, DM (reprint author), Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. EM dmbrace@lbl.gov; BLCerchiai@lbl.gov; pasqua@socrates.berkeley.edu; udayv@socrates.berkeley.edu; zumino@thsrv.lbl.gov NR 13 TC 24 Z9 24 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 JUN PY 2001 IS 6 AR 047 PG 17 WC Physics, Particles & Fields SC Physics GA 466LX UT WOS:000170648000047 ER PT J AU Chalmers, G AF Chalmers, G TI Open string decoupling and tachyon condensation SO JOURNAL OF HIGH ENERGY PHYSICS LA English DT Article DE strong coupling expansion; bosonic strings; brane dynamics in gauge theories ID FIELD-THEORY; BRANE AB The amplitudes in perturbative open string theory are examined as functions of the tachyon condensate parameter. The boundary state formalism demonstrates the decoupling of the open string modes at the non-perturbative minima of the tachyon potential via a degeneration of open world-sheets and identifies an independence of the coupling constants g(s) and g(YM) at general values of the tachyon condensate. The closed string sector is generated at the quantum level; it is also generated at the classical level perturbatively through the condensation of propagating open string modes on the D-brane degrees of freedom. C1 Argonne Natl Lab, Div High Energy Phys, Argonne, IL 60439 USA. RP Chalmers, G (reprint author), Argonne Natl Lab, Div High Energy Phys, 9700 S Cass Ave, Argonne, IL 60439 USA. EM chalmers@pcl9.hep.anl.gov NR 31 TC 16 Z9 16 U1 0 U2 0 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 JUN PY 2001 IS 6 AR 012 PG 10 WC Physics, Particles & Fields SC Physics GA 466LX UT WOS:000170648000012 ER PT J AU Diehl, M Hiller, G AF Diehl, M Hiller, G TI New ways to explore factorization in b decays SO JOURNAL OF HIGH ENERGY PHYSICS LA English DT Article DE B-physics; QCD ID FORM-FACTORS; EVOLUTION-EQUATIONS; QCD FACTORIZATION; WAVE-FUNCTIONS; HEAVY MESONS; QUARK-MODEL; BARYONS AB We propose to study factorization breaking effects in exclusive b decays where they are strongly enhanced over the factorizing contributions. This can be done by selecting final-state mesons with a small decay constant or with spin greater than one. We find a variety of decay modes which could help understand the dynamical origin of factorization and the mechanisms responsible for its breaking. C1 DESY, D-22603 Hamburg, Germany. Stanford Univ, Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. RP Diehl, M (reprint author), DESY, D-22603 Hamburg, Germany. EM markus.diehl@desy.de; ghiller@SLAC.Stanford.EDU NR 46 TC 26 Z9 26 U1 0 U2 0 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 JUN PY 2001 IS 6 AR 067 DI 10.1088/1126-6708/2001/06/067 PG 35 WC Physics, Particles & Fields SC Physics GA 466LX UT WOS:000170648000067 ER PT J AU Kachru, S McGreevy, J AF Kachru, S McGreevy, J TI M-theory on manifolds of G(2) holonomy and type-IIA orientifolds SO JOURNAL OF HIGH ENERGY PHYSICS LA English DT Article DE M-theory; string duality; superstring vacua ID COMPACT RIEMANNIAN 7-MANIFOLDS; F-THEORY; STRING DUALITY; COMPACTIFICATIONS AB We demonstrate that M-theory compactifications on 7-manifolds of G(2) holonomy, which yield 4d N = 1 supersymmetric systems, often admit at special loci in their moduli space a description as type-IIA orientifolds. In this way, we are able to find new dualities of special IIA orientifolds, including dualities which relate orientifolds of IIA strings on manifolds of different topology with different numbers of wrapped D-branes. We also discuss models which incorporate, in a natural way, compact embeddings of gauge theory/gravity dualities similar to those studied in the recent work of Atiyah, Maldacena and Vafa. C1 Stanford Univ, Dept Phys, Stanford, CA 94305 USA. Stanford Univ, SLAC, Stanford, CA 94305 USA. Univ Calif Santa Barbara, Inst Theoret Phys, Santa Barbara, CA 93106 USA. RP Kachru, S (reprint author), Stanford Univ, Dept Phys, Stanford, CA 94305 USA. EM skachru@stanford.edu; mcgreevy@stanford.edu NR 30 TC 30 Z9 30 U1 0 U2 0 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 JUN PY 2001 IS 6 AR 027 PG 14 WC Physics, Particles & Fields SC Physics GA 466LX UT WOS:000170648000027 ER PT J AU Fung, JL Weier, HUG Pedersen, RA AF Fung, JL Weier, HUG Pedersen, RA TI Detection of structural and numerical chromosome abnormalities in interphase cells using spectral imaging SO JOURNAL OF HISTOCHEMISTRY & CYTOCHEMISTRY LA English DT Article; Proceedings Paper CT Joint Meeting of the Histochemical-Society/International-Society-for-Analytical-and-Molecular -Morphology CY FEB 02-07, 2001 CL SANTA FE, NEW MEXICO SP Histochem Soc, Int Soc Analyt & Molec Morphol DE spectral imaging; chromosome abnormalities; genetic screening; in vitro fertilization; preimplantation genetic diagnosis ID TRANSLOCATIONS; DIAGNOSIS; PROBES AB Chromosome abnormalities are common causes of congenital malformations and spontaneous abortions. They include structural abnormalities, polyploidy, trisomy, and mosaicism. In in vitro fertilization (IVF) programs, preimplantation genetic diagnosis (PGD) of oocytes and embryos has become the technique of choice to select against abnormal embryos before embryo transfer. For diagnosis of structural abnormalities, we developed case-specific breakpoint-spanning DNA probes. Screening of an in-house yeast artificial chromosome (YAC) library is facilitated by information from publicly available databases and published articles. Most numerical chromosome abnormalities, on the other hand, are detrimental to early embryonic development and increase with maternal age. We therefore developed a multichromosome screening technique based on spectral imaging to simultaneously detect and score as many as 10 different chromosome types. The probe set was chosen to detect more than 70% of all numerical chromosome aberrations responsible for spontaneous abortions. Detecting structural and numerical abnormalities in single interphase cells using spectral imaging is a powerful technique for multilocus genetic screening. C1 Univ Calif San Francisco, Dept Obstet Gynecol & Reprod Sci, Reprod Genet Unit, San Francisco, CA 94143 USA. Univ Calif Berkeley, Life Sci Div 74 157, EO Lawrence Berkeley Natl Lab, Berkeley, CA USA. RP Fung, JL (reprint author), Univ Calif San Francisco, Dept Obstet Gynecol & Reprod Sci, Reprod Genet Unit, 533 Parnassus, San Francisco, CA 94143 USA. FU NIEHS NIH HHS [5-T32-ES07106-17] NR 10 TC 5 Z9 7 U1 0 U2 1 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 JUN PY 2001 VL 49 IS 6 BP 797 EP 798 PG 2 WC Cell Biology SC Cell Biology GA 441MC UT WOS:000169233300016 PM 11373329 ER PT J AU Brushia, RJ Forte, TM Oda, MN La Du, BN Bielicki, JK AF Brushia, RJ Forte, TM Oda, MN La Du, BN Bielicki, JK TI Baculovirus-mediated expression and purification of human serum paraoxonase 1A SO JOURNAL OF LIPID RESEARCH LA English DT Article DE recombinant paraoxonase; HDL; lipid peroxidation; antioxidant; atherogenesis ID LOW-DENSITY-LIPOPROTEIN; ARYLESTERASE; PROTECTION; OXIDATION; PROTEINS; DISEASE; PLASMA; LDL AB Human paraoxonase 1 (hPON1) is a lipid-associated enzyme transported on HDL, There is considerable interest in hPON1 because of its putative antioxidative/antiatherogenic properties. We have created a recombinant baculovirus (BV) to generate hPON1A in large quantities for structure-function studies and here describe the method for production and isolation of the enzyme. A high level of recombinant hPON1 type A (rPON1A) was produced by Hi-5 insect cells (40 mg/l); a fraction (similar to 10 mg/l) was secreted into the cell culture medium, but the majority (similar to 30 mg/l) remained associated with the host insect cells. Cell-associated rPON1A was purified by detergent extraction (Tergitol NP-10) followed by three simple chromatography steps (DEAE-Sepharose, Sephacryl S-200, and concanavalin A). The purified enzyme bound to concanavalin A and was converted to a lower molecular mass by endoglycosidase H digestion, suggesting that rPON1A contained high-mannose N-glycan chains. There was a significant decrease in arylesterase activity (> 99%) concomitant with enzymatic deglycosylation, rPON1A was dependent on Ca2+ for arylesterase activity, exhibiting kinetic parameters similar to native hPON1A (K-m = 3.8 +/- 2.1 vs. 3.7 +/- 2.0 mM and V-max = 1,305 +/- 668 vs. 1,361 +/- 591 U/mg protein, rPON1A and hPON1A, respectively). Both rPON1A and hPON1A efficiently inhibited lipoxygenase-mediated peroxidation of phospholipid, In contrast to the arylesterase activity, which was sensitive to endoglycosidase I-I treatment, enzymatic deglycosylation did not inhibit the antioxidant activity of rPON1A. In conclusion, our BV-mediated PON1A expression system appears ideally suited for the production of relatively large quantities of rPON1A for structure-function studies. - Brushia, R.J., T. M. Forte, M. N. Oda, B. N. La Du, and J. K. Bielicki. Baculovirus-mediated expression and purification of human serum paraoxonase 1A. C1 Univ Calif Berkeley, Lawrence Berkeley Nalt Lab, Dept Mol & Nucl Med, Div Life Sci, Berkeley, CA 94720 USA. Univ Michigan, Dept Pharmacol, Ann Arbor, MI 48109 USA. RP Bielicki, JK (reprint author), Univ Calif Berkeley, Lawrence Berkeley Nalt Lab, Dept Mol & Nucl Med, Div Life Sci, Berkeley, CA 94720 USA. FU NHLBI NIH HHS [HL59483-01A2, HL07279, HL18754] NR 32 TC 28 Z9 28 U1 0 U2 6 PU LIPID RESEARCH INC PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814-3998 USA SN 0022-2275 J9 J LIPID RES JI J. Lipid Res. PD JUN PY 2001 VL 42 IS 6 BP 951 EP 958 PG 8 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA 438BE UT WOS:000169033200009 PM 11369803 ER PT J AU Levin, EM Gschneidner, KA Pecharsky, VK AF Levin, EM Gschneidner, KA Pecharsky, VK TI Magnetic properties of Gd-5(Si1.5Ge2.5) near the temperature and magnetic field induced first order phase transition SO JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS LA English DT Article DE magnetic-martensitic phase transition; first order phase transformation; exchange interaction; AC magnetic susceptibility; DC magnetization ID ELECTRICAL-RESISTANCE; GD-5(SI2GE2); EXCHANGE; MAGNETORESISTANCE; GD-5(SI1.8GE2.2); ER(CO1-XSIX)(2); INSTABILITY; SYSTEM; ALLOYS AB The temperature (from 5 to 300 K) and DC magnetic field (from 0 to 90 kOe) dependencies of the DC magnetization and magnetic susceptibility, and the temperature (from 5 to 350 K) dependency of the AC magnetic susceptibility of Gd-5(Si1.5Ge2.5) have been studied. The temperature and/or magnetic field Induced magnetic phase transition in Gd-5(Si1.5Ge2.5) is a first order ferromagnet tt paramagnet transition. The temperature of the magnetic transition in low AC magnetic field is 206 and 217 K for cooling and heating, respectively. The DC magnetic field increases the transition temperature by similar to0.36K/kOe indicating that the paramagnetic phase can be reversibly transformed into the ferromagnetic phase. When the magnetic field is removed, the ferromagnetic phase transforms into the paramagnetic phase showing a large remanence-free hysteresis. The magnetic phase diagram based on the isothermal magnetic field dependence of the DC magnetization at various temperatures for Gd-5(Si1.5Ge2.5) is proposed. The magnetic field dependence of the magnetization in the vicinity of the first order phase transition shows evidence for the formation of a magnetically heterogeneous system in the volume of Gd-5(Si1.5Ge2.5) specimen where the magnetically ordered (ferromagnetic) and disordered (paramagnetic) phases co-exist. (C) 2001 Elsevier Science B.V. All rights reserved. C1 Iowa State Univ Sci & Technol, Ames Lab, Dept Mat Sci & Engn, Ames, IA 50011 USA. Iowa State Univ Sci & Technol, Dept Mat Sci & Engn, Ames, IA 50011 USA. RP Pecharsky, VK (reprint author), Iowa State Univ Sci & Technol, Ames Lab, Dept Mat Sci & Engn, 242A Spedding, Ames, IA 50011 USA. NR 27 TC 26 Z9 30 U1 0 U2 4 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0304-8853 J9 J MAGN MAGN MATER JI J. Magn. Magn. Mater. PD JUN PY 2001 VL 231 IS 2-3 BP 135 EP 145 DI 10.1016/S0304-8853(01)00154-8 PG 11 WC Materials Science, Multidisciplinary; Physics, Condensed Matter SC Materials Science; Physics GA 441NA UT WOS:000169235400002 ER PT J AU Girt, E Krishnan, KM Thomas, G Girt, E Altounian, Z AF Girt, E Krishnan, KM Thomas, G Girt, E Altounian, Z TI Coercivity limits and mechanism in nanocomposite Nd-Fe-B alloys SO JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS LA English DT Article DE alloys; coercivity; nanocomposites; interacting grains ID MAGNETIC-PROPERTIES; PERMANENT-MAGNETS; PR-FE; CRYSTALLIZATION; DEPENDENCE; FIELD AB The largest coercivity in the Nd-Fe-B system was achieved by systematically tailoring the microstructure from strongly interacting Nd2Fe14B grains to magnetically isolated Nd2Fe14B grains in a Nd-rich matrix. The crystal structure, phase purity and magnetic properties of the Nd-Fe-B samples were extensively measured. In particular energy-filtered images, using spatially resolved measurements of inner-shell ionization edges, was critical in evaluating the particle shapes (platelets with the crystallographic c-axis normal to the plate), size (similar to 100 x 40 x 25 nm) and distribution. For randomly oriented, non-interacting particles, the largest observed coercivity, mu H-0(c) similar to 2.75 T is - 83% of the theoretical limit expected for Stoner-Wohlfarth coherent rotation behavior including demagnetization effects. Initial magnetization curves of thermally demagnetized Nd-Fe-B samples show a systematic increase in susceptibility with an increase in Nd concentration as a result of a competition between contributions from strongly interacting Nd2Fe14B grains with grain sizes smaller or equal to the magnetic domain size and completely isolated multidomain Nd2Fe14B grains. The possible coercivity mechanisms in such Nd-Fe-B samples are discussed. Crown Copyright (C) 2001 Published by Elsevier Science B.V. All rights reserved. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Mat Sci & Mineral Engn, Berkeley, CA 94720 USA. Fac Nat Sci & Math, Dept Phys, Sarajevo 71000, Bosnia & Herceg. McGill Univ, Ctr Phys Mat, Dept Phys, Montreal, PQ H3A 2T8, Canada. RP Krishnan, KM (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. RI Altounian, Zaven/A-2073-2008 NR 23 TC 19 Z9 19 U1 0 U2 11 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0304-8853 J9 J MAGN MAGN MATER JI J. Magn. Magn. Mater. PD JUN PY 2001 VL 231 IS 2-3 BP 219 EP 230 DI 10.1016/S0304-8853(01)00031-2 PG 12 WC Materials Science, Multidisciplinary; Physics, Condensed Matter SC Materials Science; Physics GA 441NA UT WOS:000169235400013 ER PT J AU Novick, VJ Ahluwalia, RK Natesan, K Soppet, WK Spencer, BE AF Novick, VJ Ahluwalia, RK Natesan, K Soppet, WK Spencer, BE TI Performance of an iron aluminide metal filter in a reducing environment SO JOURNAL OF MATERIALS ENGINEERING AND PERFORMANCE LA English DT Article DE aluminides; coal gasification filters; Fe-28% Al-5% Cr; fracture toughness; high temperature AB A laboratory-scale apparatus has been used for unattended, long duration, continuous, flow-through testing of an iron aluminide sintered metal filter under reducing conditions. Two candle specimens were exposed for 1009 to 2251 h to 600 degreesC gas containing 5% CO, 11% H-2, 12% CO2, 12% H2O, 60% N-2, 0.5% H2S, 2.4 ppmv NaCl, 4.7 ppmv KCl, 26.1 ppmv HCI, and 5530 ppmw ash from a transport reactor operated in gasification mode. A database was established on pressure drop of the as-received and exposed filter as a function of face velocity and temperature. Tests were conducted to investigate the effects of back pulse parameters on filter regenerability, Results are reported on the critical reservoir pressure and pulse duration for maintaining a stable saw-tooth profile of pressure drop across the filter element. Data are obtained to characterize the effect of chemical and thermal aging on tensile strength, fast fracture strength, and microstructure. C1 Argonne Natl Lab, Argonne, IL 60439 USA. RP Natesan, K (reprint author), Argonne Natl Lab, 9700 S Cass Ave, Argonne, IL 60439 USA. NR 6 TC 2 Z9 2 U1 1 U2 2 PU ASM INTERNATIONAL PI MATERIALS PARK PA SUBSCRIPTIONS SPECIALIST CUSTOMER SERVICE, MATERIALS PARK, OH 44073-0002 USA SN 1059-9495 J9 J MATER ENG PERFORM JI J. Mater. Eng. Perform. PD JUN PY 2001 VL 10 IS 3 BP 349 EP 361 DI 10.1361/105994901770345079 PG 13 WC Materials Science, Multidisciplinary SC Materials Science GA 442UU UT WOS:000169304000014 ER PT J AU Riester, L Bell, TJ Fischer-Cripps, AC AF Riester, L Bell, TJ Fischer-Cripps, AC TI Analysis of depth-sensing indentation tests with a Knoop indenter SO JOURNAL OF MATERIALS RESEARCH LA English DT Article ID ELASTIC-MODULUS AB The present work shows how data obtained in a depth-sensing indentation test using a Knoop indenter may be analyzed to provide elastic modulus and hardness of the specimen material, The method takes into account the elastic recovery along the direction of the short axis of the residual impression as the indenter is removed. If elastic recovery is not accounted for, the elastic modulus and hardness are overestimated by an amount that depends on the ratio of E/H of the specimen material. The new method of analysis expresses the elastic recovery of the short diagonal of the residual impression into an equivalent face angle for one side of the Knoop indenter. Conventional methods of analysis using this corrected angle provide results for modulus and hardness that are consistent with those obtained with other types of indenters. C1 CSIRO, Div Telecommun & Ind Phys, Lindfield, NSW 2070, Australia. Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Fischer-Cripps, AC (reprint author), CSIRO, Div Telecommun & Ind Phys, POB 218, Lindfield, NSW 2070, Australia. NR 12 TC 12 Z9 13 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 JUN PY 2001 VL 16 IS 6 BP 1660 EP 1667 DI 10.1557/JMR.2001.0230 PG 8 WC Materials Science, Multidisciplinary SC Materials Science GA 440ZM UT WOS:000169206600019 ER PT J AU Curtright, T Uematsu, T Zachos, C AF Curtright, T Uematsu, T Zachos, C TI Generating all Wigner functions SO JOURNAL OF MATHEMATICAL PHYSICS LA English DT Article ID SUPERSYMMETRIC LIOUVILLE THEORY; PHASE-SPACE FORMULATION; WEAK-COUPLING ANALYSIS; QUANTUM-MECHANICS; FIELD-THEORY; DEFORMATION THEORY; QUANTIZATION; PHYSICS AB In the context of phase-space quantization, matrix elements and observables result from integration of c-number functions over phase space, with Wigner functions serving as the quasiprobability measure. The complete sets of Wigner functions necessary to expand all phase-space functions include off-diagonal Wigner functions, which may appear technically involved. Nevertheless, it is shown here that suitable generating functions of these complete sets can often be constructed, which are relatively simple, and lead to compact evaluations of matrix elements. New features of such generating functions are detailed and explored for integer-indexed sets, such as for the harmonic oscillator, as well as continuously indexed ones, such as for the linear potential and the Liouville potential. The utility of such generating functions is illustrated in the computation of star functions, spectra, and perturbation theory in phase space. (C) 2001 American Institute of Physics. C1 Univ Miami, Dept Phys, Coral Gables, FL 33124 USA. Kyoto Univ, FIHS, Dept Fundamental Sci, Kyoto 6068501, Japan. Argonne Natl Lab, Div High Energy Phys, Argonne, IL 60439 USA. RP Curtright, T (reprint author), Univ Miami, Dept Phys, POB 248046, Coral Gables, FL 33124 USA. RI zachos, cosmas/C-4366-2014; Curtright, Thomas/B-6840-2015; OI zachos, cosmas/0000-0003-4379-3875; Curtright, Thomas/0000-0001-7031-5604 NR 54 TC 42 Z9 42 U1 0 U2 1 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0022-2488 J9 J MATH PHYS JI J. Math. Phys. PD JUN PY 2001 VL 42 IS 6 BP 2396 EP 2415 DI 10.1063/1.1366327 PG 20 WC Physics, Mathematical SC Physics GA 434RN UT WOS:000168829800003 ER PT J AU Park, JS Chu, LL Oliver, AD Gianchandani, YB AF Park, JS Chu, LL Oliver, AD Gianchandani, YB TI Bent-beam electrothermal actuators - Part II: Linear and rotary microengines SO JOURNAL OF MICROELECTROMECHANICAL SYSTEMS LA English DT Article DE inchworm; micromachining; micromotor; positioner; scanner; thermal actuator ID MICROMOTORS; FABRICATION; DESIGN AB This paper reports on the use of bent-beam electrothermal actuators for the purpose of generating rotary and long-throw rectilinear displacements. The rotary displacements are achieved by orthogonally arranged pairs of cascaded actuators that are used to rotate a gear. Devices were fabricated using electroplated Ni, p(++) Si, and polysilicon as structural materials. Displacements of 20-30 mum with loading forces > 150 muN at actuation voltages < 12 V and power dissipation < 300 mW could be achieved in the orthogonally arranged actuator pairs, A design that occupies < 1 mm(2) area is presented. Long-throw rectilinear displacements were achieved by inchworm mechanisms in which pairs of opposing actuators grip and shift a central shank that is cantilevered on a flexible suspension. A passive lock holds the displaced shank between pushes and when the power is off, This arrangement permits large output forces to be developed at large displacements, and requires zero standby power. Several designs were fabricated using electroplated Ni as the structural material. Forces > 200 muN at displacements > 100 mum were measured. C1 Univ Wisconsin, Dept Elect Engn & Comp Engn, Madison, WI 53706 USA. Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Univ Wisconsin, Dept Elect Engn & Comp Engn, Madison, WI 53706 USA. EM yogesh@engr.wisc.edu NR 21 TC 104 Z9 107 U1 1 U2 10 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855-4141 USA SN 1057-7157 EI 1941-0158 J9 J MICROELECTROMECH S JI J. Microelectromech. Syst. PD JUN PY 2001 VL 10 IS 2 BP 255 EP 262 DI 10.1109/84.925774 PG 8 WC Engineering, Electrical & Electronic; Nanoscience & Nanotechnology; Instruments & Instrumentation; Physics, Applied SC Engineering; Science & Technology - Other Topics; Instruments & Instrumentation; Physics GA 438EZ UT WOS:000169041800011 ER PT J AU Brown, KK Franklin, MC Binz, JG Henke, BR Winegar, DA Taj, S Bahirwani, R Michaud, EJ Jones, BH Beets, AL Knapp, FF AF Brown, KK Franklin, MC Binz, JG Henke, BR Winegar, DA Taj, S Bahirwani, R Michaud, EJ Jones, BH Beets, AL Knapp, FF TI PPAR gamma activator GI251929 alters glucose and lipid uptake and metabolism: Cardiac gene expression and tracer studies with [I-125]-BMIPP and [F-18]-2-FDG SO JOURNAL OF MOLECULAR AND CELLULAR CARDIOLOGY LA English DT Meeting Abstract C1 GlaxoSmithKline, Res Triangle Pk, NC USA. Oak Ridge Natl Lab, Oak Ridge, TN USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU ACADEMIC PRESS LTD- ELSEVIER SCIENCE LTD PI LONDON PA 24-28 OVAL RD, LONDON NW1 7DX, ENGLAND SN 0022-2828 EI 1095-8584 J9 J MOL CELL CARDIOL JI J. Mol. Cell. Cardiol. PD JUN PY 2001 VL 33 IS 6 BP A163 EP A163 DI 10.1016/S0022-2828(01)90624-8 PG 1 WC Cardiac & Cardiovascular Systems; Cell Biology SC Cardiovascular System & Cardiology; Cell Biology GA 478BH UT WOS:000171322700645 ER PT J AU Forst, CV Schulten, K AF Forst, CV Schulten, K TI Phylogenetic analysis of metabolic pathways SO JOURNAL OF MOLECULAR EVOLUTION LA English DT Article DE metabolic networks; phylogeny; electron transfer; aminoacid biosynthesis; microbial genomes ID COMPLETE GENOME SEQUENCE; EVOLUTION; PATHOGEN; CONSERVATION; TRACHOMATIS; SPIROCHETE; PNEUMONIAE; PROTEINS; VIEW AB The information provided by completely sequenced genomes can yield insights into the multi-level organization of organisms and their evolution. At the lowest level of molecular organization individual enzymes are formed, often through assembly of multiple polypeptides. At a higher level, sets of enzymes group into metabolic networks. Much has been learned about the relationship of species from phylogenetic trees comparing individual enzymes. In this article we extend conventional phylogenetic analysis of individual enzymes in different organisms to the organisms' metabolic networks. For this purpose we suggest a method that combines sequence information with information about the underlying reaction networks. A distance between pathways is defined as incorporating distances between substrates and distances between corresponding enzymes. The new analysis is applied to electron-transfer and amino acid biosynthesis networks yielding a more comprehensive understanding of similarities and differences between organisms. C1 Univ Illinois, Theoret Biophys Grp, Beckman Inst, Urbana, IL 61801 USA. RP Los Alamos Natl Lab, Biosci Di, Mailstop M888, Los Alamos, NM 87545 USA. EM chris@lanl.gov RI Schulten, Klaus/D-5561-2009 FU NCRR NIH HHS [5 P41 RR05969] NR 59 TC 54 Z9 58 U1 0 U2 2 PU SPRINGER PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 0022-2844 EI 1432-1432 J9 J MOL EVOL JI J. Mol. Evol. PD JUN PY 2001 VL 52 IS 6 BP 471 EP 489 PG 19 WC Biochemistry & Molecular Biology; Evolutionary Biology; Genetics & Heredity SC Biochemistry & Molecular Biology; Evolutionary Biology; Genetics & Heredity GA 437KU UT WOS:000168991500001 PM 11443351 ER PT J AU Patterson, JR Vohra, YK Weir, ST Akella, J AF Patterson, JR Vohra, YK Weir, ST Akella, J TI Single-wall carbon nanotubes under high pressures to 62 GPa studied using designer diamond anvils SO JOURNAL OF NANOSCIENCE AND NANOTECHNOLOGY LA English DT Article DE nanotubes; diamond; high pressure; hardness; nanoindentation; electrical resistance; diamond anvils ID FULLERITE C-60; HARDNESS; PHASES AB Single-wall carbon nanotube samples were studied under high pressures to 62 GPa using designer diamond anvils with buried electrical microprobes that allowed for monitoring of the four-probe electrical resistance at elevated pressure. After initial densification, the electrical resistance shows a steady increase from 3 to 42 GPa, followed by a sharp rise above 42 GPa. This sharp rise in electrical resistance at high pressures is attributed to opening of an energy band gap with compression. Nanoindentation hardness measurements on the pressure-treated carbon nanotube samples gave a hardness value of 0.50 +/- 0.03 GPa. This hardness value is approximately 2 orders of magnitude lower than the amorphous carbon phase produced in fullerenes under similar conditions. Therefore, the pressure treatment of single-wall carbon nanotubes to 62 GPa did not produce a superhard carbon phase. C1 Univ Alabama, Dept Phys, Birmingham, AL 35294 USA. Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Vohra, YK (reprint author), Univ Alabama, Dept Phys, Birmingham, AL 35294 USA. RI Weir, Samuel/H-5046-2012 NR 17 TC 16 Z9 16 U1 1 U2 3 PU AMER SCIENTIFIC PUBLISHERS PI STEVENSON RANCH PA 25650 NORTH LEWIS WAY, STEVENSON RANCH, CA 91381-1439 USA SN 1533-4880 J9 J NANOSCI NANOTECHNO JI J. Nanosci. Nanotechnol. PD JUN PY 2001 VL 1 IS 2 BP 143 EP 147 DI 10.1166/jnn.2001.026 PG 5 WC Chemistry, Multidisciplinary; Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Physics, Applied; Physics, Condensed Matter SC Chemistry; Science & Technology - Other Topics; Materials Science; Physics GA 529GJ UT WOS:000174291400005 PM 12914044 ER PT J AU Stolyarov, VV Zhu, YT Lowe, TC Valiev, RZ AF Stolyarov, VV Zhu, YT Lowe, TC Valiev, RZ TI Microstructures and properties of ultrafine-grained pure titanium processed by equal-channel angular pressing and cold deformation SO JOURNAL OF NANOSCIENCE AND NANOTECHNOLOGY LA English DT Article DE ultrafine-grained titanium; equal-channel angular pressing; cold deformation; titanium; microstructures; properties ID EXTRUSION; REFINEMENT; ALUMINUM; ECAP; TI AB Equal-channel angular pressing (ECAP) has been used to refine the grain size of commercially pure (CP) titanium as well as other metals and alloys. CP-Ti is usually processed at about 400 degreesC because it lacks sufficient ductility at lower temperature. The warm processing temperature limits the ability of the ECAP technique to improve the strength of CP-Ti. We have employed cold deformation following warm ECAP to further improve the strength of CP-Ti. Ti billets were first processed for eight passes via ECAP route B(C), with a clockwise rotation of 90degrees between adjacent passes. The grain size obtained by ECAP alone is about 260 nm. The billets were further processed by cold deformation (cold rolling) to increase the crystalline defects such as dislocations. The strength of pure Ti was improved from 380 to around 1000 MPa by the two-step process. This article reports the microstructures, microhardness, tensile properties, and thermal stability of these Ti billets processed by a combination of ECAP and cold deformation. C1 Los Alamos Natl Lab, Div Mat Sci & Technol, Los Alamos, NM 87544 USA. Ufa State Aviat Tech Univ, Inst Phys Adv Mat, Ufa 450000, Russia. RP Zhu, YT (reprint author), Los Alamos Natl Lab, Div Mat Sci & Technol, MS G755, Los Alamos, NM 87544 USA. RI Zhu, Yuntian/B-3021-2008 OI Zhu, Yuntian/0000-0002-5961-7422 NR 19 TC 14 Z9 15 U1 1 U2 9 PU AMER SCIENTIFIC PUBLISHERS PI VALENCIA PA 26650 THE OLD RD, STE 208, VALENCIA, CA 91381-0751 USA SN 1533-4880 J9 J NANOSCI NANOTECHNO JI J. Nanosci. Nanotechnol. PD JUN PY 2001 VL 1 IS 2 BP 237 EP 242 DI 10.1166/jnn.2001.034 PG 6 WC Chemistry, Multidisciplinary; Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Physics, Applied; Physics, Condensed Matter SC Chemistry; Science & Technology - Other Topics; Materials Science; Physics GA 529GJ UT WOS:000174291400018 PM 12914057 ER PT J AU Gash, AE Tillotson, TM Satcher, JH Hrubesh, LW Simpson, RL AF Gash, AE Tillotson, TM Satcher, JH Hrubesh, LW Simpson, RL TI New sol-gel synthetic route to transition and main-group metal oxide aerogels using inorganic salt precursors SO JOURNAL OF NON-CRYSTALLINE SOLIDS LA English DT Article; Proceedings Paper CT 6th International Symposium on Aerogels (ISA-6) CY OCT 08-11, 2000 CL ALBUQUERQUE, NM SP NanoPore Inc, Cabot Corp, Lawrence Livermore Natl Lab ID CHROMIA; CATALYSTS; EVOLUTION AB We have developed a new sol-gel route to synthesize several different transition and main-group metal oxide aerogels. The approach is straightforward, inexpensive, versatile, and it produces monolithic microporous materials with high surface areas. Specifically, we report the use of epoxides as gelation agents for the sol-gel synthesis of chromia aerogels and xerogels from simple Cr(III) inorganic salts. The dependence of both gel formation and its rate was studied by varying the solvent used, the Cr(III) precursor salt, the epoxide/Cr(III) ratio, as well as the type of epoxide employed. All of these variables were shown to affect the rate of gel formation and provide a convenient control of this parameter. Dried chromia aerogels were characterized by high-resolution transmission electron microscopy (HRTEM) and nitrogen adsorption/desorption analyses, results of which will be presented. The results presented hcl c show that rigid monolithic metal oxide aerogels can be prepared from solutions of their respective metal ion salts (Fe3+, Al3+, In3+, Ga3+, Zr4+ Hf4+, Ta5+, Nb5+, and W6+), provided the formal oxidation state of the metal ion is greater. than or equal to +3. Conversely, when di-valent transition metal salts are used precipitated solids are the products. (C) 2001 Elsevier Science B.V. All rights reserved. C1 Lawrence Livermore Natl Lab, Chem & Mat Sci Directorate, Livermore, CA 94550 USA. Lawrence Livermore Natl Lab, Energet Mat Ctr, Livermore, CA 94550 USA. RP Lawrence Livermore Natl Lab, Chem & Mat Sci Directorate, POB 808 L-092, Livermore, CA 94550 USA. EM gash2@llnl.gov NR 19 TC 183 Z9 196 U1 7 U2 64 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3093 EI 1873-4812 J9 J NON-CRYST SOLIDS JI J. Non-Cryst. Solids PD JUN 1 PY 2001 VL 285 IS 1-3 BP 22 EP 28 DI 10.1016/S0022-3093(01)00427-6 PG 7 WC Materials Science, Ceramics; Materials Science, Multidisciplinary SC Materials Science GA 444QJ UT WOS:000169410800005 ER PT J AU Poco, JF Satcher, JH Hrubesh, LW AF Poco, JF Satcher, JH Hrubesh, LW TI Synthesis of high porosity, monolithic alumina aerogels SO JOURNAL OF NON-CRYSTALLINE SOLIDS LA English DT Article; Proceedings Paper CT 6th International Symposium on Aerogels (ISA-6) CY OCT 08-11, 2000 CL ALBUQUERQUE, NEW MEXICO SP NanoPore Inc, Cabot Corp, Lawrence Livermore Natl Lab ID SILICA AEROGELS; ALKOXIDES AB Many non-silica aerogels are notably weak and fragile in monolithic form. In particular, few monolithic aerogels with densities less than 50 kg/m(3) have any significant strength. It is especially difficult to prepare uncracked monoliths of pure alumina aerogels that are robust and moisture stable. In this paper, we discuss the synthesis of unusually strong, stable, monolithic, high porosity (> 98% porous) alumina aerogels, using a two-step sol-gel process. The alumina aerogels have a polycrystalline morphology that results in enhanced physical properties. For an alumina aerogel with a density of 37 kg/m(3), the specific surface area is 376 m(2)/g, the elastic modulus is 550 kPa, and the thermal conductivities at 30 degreesC, 400 degreesC and 800 degreesC, are 29, 98 and 298 mW/mK, respectively. All of the measured physical properties of the alumina aerogels except the specific surface area are superior to those for silica aerogels for equivalent densities. (C) 2001 Elsevier Science B.V. All rights reserved. C1 Univ Calif Lawrence Livermore Natl Lab, Dept Chem & Mat Sci, Livermore, CA 94550 USA. RP Hrubesh, LW (reprint author), Univ Calif Lawrence Livermore Natl Lab, Dept Chem & Mat Sci, Livermore, CA 94550 USA. NR 22 TC 74 Z9 92 U1 10 U2 55 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 JUN 1 PY 2001 VL 285 IS 1-3 BP 57 EP 63 DI 10.1016/S0022-3093(01)00432-X PG 7 WC Materials Science, Ceramics; Materials Science, Multidisciplinary SC Materials Science GA 444QJ UT WOS:000169410800010 ER PT J AU Fan, HY Van Swol, F Lu, YF Brinker, CJ AF Fan, HY Van Swol, F Lu, YF Brinker, CJ TI Multiphased assembly of nanoporous silica particles SO JOURNAL OF NON-CRYSTALLINE SOLIDS LA English DT Article; Proceedings Paper CT 6th International Symposium on Aerogels (ISA-6) CY OCT 08-11, 2000 CL ALBUQUERQUE, NEW MEXICO SP NanoPore Inc, Cabot Corp, Lawrence Livermore Natl Lab ID MESOPOROUS SILICA; MACROPOROUS MEMBRANES; INORGANIC OXIDES; POROUS MATERIALS; NANOSTRUCTURES; EVAPORATION; TEMPLATES AB Porous silica nanoparticles with well-defined mesopores and voids are described. The silica nanoparticles are produced in a rapid aerosol process. The evaporation of solvent during aerosol generation induces multiphased assembly confined to an aerosol droplet containing polystyrene spheres/silica, polystyrene spheres/surfactant/silica or microemulsions/silica. After removal of surfactants, polymer spheres, and microemulsion, the resulting materials exhibit controlled meso- and macro-porosity. TEM and nitrogen sorption isotherms have been used to characterize the porous silica particles. The silica particles templated by polystyrene spheres possess 100 nm voids. The surfactants, as secondary templates, are used to form a mesophase to interconnect the macropores. For the microemulsion-templated silica nanoparticles, the porosity and cell size are controlled by the amount of oil and the size of the swelling molecule. (C) 2001 Elsevier Science B.V. All rights reserved. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. Univ New Mexico, Dept Chem & Nucl Engn, Ctr Microengineered Mat, Albuquerque, NM 87131 USA. RP Brinker, CJ (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. NR 24 TC 50 Z9 50 U1 1 U2 30 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 JUN 1 PY 2001 VL 285 IS 1-3 BP 71 EP 78 DI 10.1016/S0022-3093(01)00434-3 PG 8 WC Materials Science, Ceramics; Materials Science, Multidisciplinary SC Materials Science GA 444QJ UT WOS:000169410800012 ER PT J AU Fan, HY Bentley, HR Kathan, KR Clem, P Lu, YF Brinker, CJ AF Fan, HY Bentley, HR Kathan, KR Clem, P Lu, YF Brinker, CJ TI Self-assembled aerogel-like low dielectric constant films SO JOURNAL OF NON-CRYSTALLINE SOLIDS LA English DT Article; Proceedings Paper CT 6th International Symposium on Aerogels (ISA-6) CY OCT 08-11, 2000 CL ALBUQUERQUE, NEW MEXICO SP NanoPore Inc, Cabot Corp, Lawrence Livermore Natl Lab ID MESOPOROUS SILICA FILMS; NANOSTRUCTURES AB A series of new spin-on nanoporous silica films with controlled porosity and dielectric constants were prepared by evaporation induced self-assembly (EISA) during spin-coating. Starting with a homogeneous solution of soluble silica and surfactant/swelling agent prepared in an alcohol/water solvent, preferential evaporation of alcohol during spin-coating results in the hierarchical self-assembly of surfactants plus swelling agent and soluble silica into a templated microemulsion system. Silicate polymerization followed by removal of surfactant and swelling agents via immediate calcination results in a highly porous silica film of the liquid crystalline assembly with controlled porosity ranging from 50% to 90% and dielectric constant ranging from 1.3 to 2.6. TEM and surface acoustic wave (SAW) techniques were used to characterize the microstructure of the films. The dielectric constant, Young's modulus, and hardness of the final films are also discussed. (C) 2001 Elsevier Science B.V. All rights reserved. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. Univ New Mexico, Dept Chem & Nucl Engn, NSF Ctr Micro Engn Mat, Adv Mat Lab, Albuquerque, NM 87106 USA. RP Brinker, CJ (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. NR 14 TC 90 Z9 92 U1 3 U2 25 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 JUN 1 PY 2001 VL 285 IS 1-3 BP 79 EP 83 DI 10.1016/S0022-3093(01)00435-5 PG 5 WC Materials Science, Ceramics; Materials Science, Multidisciplinary SC Materials Science GA 444QJ UT WOS:000169410800013 ER PT J AU Ayers, MR Hunt, AJ AF Ayers, MR Hunt, AJ TI Synthesis and properties of chitosan-silica hybrid aerogels SO JOURNAL OF NON-CRYSTALLINE SOLIDS LA English DT Article; Proceedings Paper CT 6th International Symposium on Aerogels (ISA-6) CY OCT 08-11, 2000 CL ALBUQUERQUE, NEW MEXICO SP NanoPore Inc, Cabot Corp, Lawrence Livermore Natl Lab AB Chitosan, a polymer that is soluble in dilute aqueous acid, is derived from chitin, a natural polyglucosamide. Aquagels, where the solid phase consists of both chitosan and silica, can be easily prepared by using an acidic solution of chitosan to catalyze the hydrolysis and condensation of tetraethylorthosilicate. Gels with chitosan/tetraethoxysilane (TEOS) mass ratios of 0.1-1.1 have been prepared by this method. Standard drying processes using CO2 give the corresponding aerogels. The amount of chitosan in the gel plays a role in the shrinkage of the aerogel during drying. Gels with the lowest chitosan/silica ratios show the most linear shrinkage, up to 24%, while those with the highest ratios show only a 7% linear shrinkage. Pyrolysis at 700 degreesC under nitrogen produces a darkened aerogel due to the thermal decomposition of the chitosan, however, the aerogel retains its monolithic form. The pyrolyzed aerogels absorb slightly more infrared radiation in the 2-5 mum region than the original aerogels. B.E.T. surface areas of these aerogels range from 470 to 750 m(2)/g. Biocompatibility screening of this material shows a very high value for hemolysis, but a low value for cytotoxicity. (C) 2001 Elsevier Science B.V. All rights reserved. C1 EO Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. RP Hunt, AJ (reprint author), EO Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. NR 5 TC 71 Z9 76 U1 5 U2 63 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 JUN 1 PY 2001 VL 285 IS 1-3 BP 123 EP 127 DI 10.1016/S0022-3093(01)00442-2 PG 5 WC Materials Science, Ceramics; Materials Science, Multidisciplinary SC Materials Science GA 444QJ UT WOS:000169410800020 ER PT J AU Hunt, AJ Ayers, MR AF Hunt, AJ Ayers, MR TI Investigations of silica alcogel aging using coherent light SO JOURNAL OF NON-CRYSTALLINE SOLIDS LA English DT Article; Proceedings Paper CT 6th International Symposium on Aerogels (ISA-6) CY OCT 08-11, 2000 CL ALBUQUERQUE, NEW MEXICO SP NanoPore Inc, Cabot Corp, Lawrence Livermore Natl Lab ID SCATTERING; GEL AB Light scattering methods have previously been used to monitor the formation of gels. In this report we present new light scattering techniques to study the properties of silica alcogels during the aging process. Monitoring one particular polarization transformation of scattered light with time reveals a clear increase in internal strain in standing alcogels with time. The stress birefringence coefficient of an acid-catalyzed SiO2 gel was found to he 1.3 Brewsters. Additionally, the evolution of the stiffness of alcogels was investigated using laser speckle methods. Specifically, image analysis of specklegrams obtained during multi-frequency acoustic excitation of aging gels was used to non-destructively measure the hardening of alcogels. For an acid-catalyzed gel with a theoretical density of similar to0.05 g/cm(3) SiO2, the rate of hardening is found to be greatest between gelation and 2x the gel time, and drops considerably thereafter. The Young's modulus of the gel can be monitored over time with this method and was found to range from 6.2 x 10(3) N/m(2) after 6 h to 2.2 x 10(5) N/m(2) after 24 h for acid-catalyzed silica gels. (C) 2001 Elsevier Science B.V. All rights reserved. C1 EO Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. RP Hunt, AJ (reprint author), EO Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. NR 9 TC 2 Z9 2 U1 0 U2 5 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 JUN 1 PY 2001 VL 285 IS 1-3 BP 162 EP 166 DI 10.1016/S0022-3093(01)00448-3 PG 5 WC Materials Science, Ceramics; Materials Science, Multidisciplinary SC Materials Science GA 444QJ UT WOS:000169410800026 ER PT J AU Hrubesh, LW Coronado, PR Satcher, JH AF Hrubesh, LW Coronado, PR Satcher, JH TI Solvent removal from water with hydrophobic aerogels SO JOURNAL OF NON-CRYSTALLINE SOLIDS LA English DT Article; Proceedings Paper CT 6th International Symposium on Aerogels (ISA-6) CY OCT 08-11, 2000 CL ALBUQUERQUE, NEW MEXICO SP NanoPore Inc, Cabot Corp, Lawrence Livermore Natl Lab AB Hydrophobic aerogels are shown to be efficient absorbers of solvents from water. Solvents miscible with water are separated from it because the solvents are more volatile than water and they enter the porous aerogel as a vapor across the liquid water/solid interface. Solvents that are immiscible with water are separated from it by selectively wetting the aerogel. Adsorption isotherms are presented for hydrophobic silica aerogels, for several solvents (e.g., toluene, ethyl alcohol, trichloroethylene, chlorobenzene) in water mixtures. The adsorption capacities are compared with the standard activated carbon. Our measurements show that the adsorption capacity of the hydrophobic silica aerogels exceed the capacity of comparable granular activated carbon (GAC), on a gram-per-gram basis, for all of the solvents tested. The improved performance of adsorption capacity by the aerogel over the GAC ranged from factors of similar to 30 times for low molecular weight, highly soluble solvents, to factors of 130 times for immiscible solvents. (C) 2001 Elsevier Science B.V. All rights reserved. C1 Univ Calif Lawrence Livermore Natl Lab, Dept Chem & Mat Sci, Livermore, CA 94550 USA. RP Hrubesh, LW (reprint author), Univ Calif Lawrence Livermore Natl Lab, Dept Chem & Mat Sci, POB 808,L-487, Livermore, CA 94550 USA. NR 19 TC 88 Z9 98 U1 2 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 JUN 1 PY 2001 VL 285 IS 1-3 BP 328 EP 332 DI 10.1016/S0022-3093(01)00475-6 PG 5 WC Materials Science, Ceramics; Materials Science, Multidisciplinary SC Materials Science GA 444QJ UT WOS:000169410800051 ER PT J AU Tillotson, TM Gash, AE Simpson, RL Hrubesh, LW Satcher, JH Poco, JF AF Tillotson, TM Gash, AE Simpson, RL Hrubesh, LW Satcher, JH Poco, JF TI Nanostructured energetic materials using sol-gel methodologies SO JOURNAL OF NON-CRYSTALLINE SOLIDS LA English DT Article; Proceedings Paper CT 6th International Symposium on Aerogels (ISA-6) CY OCT 08-11, 2000 CL ALBUQUERQUE, NEW MEXICO SP NanoPore Inc, Cabot Corp, Lawrence Livermore Natl Lab AB We have utilized a sol-gel synthetic approach in preparing nano-sized transition metal oxide components for new energetic nanocomposites. Nanocomposites of Fe2O3/Al(s), are readily produced from a solution of Fe(lll) salt by adding an organic epoxide and a powder of the fuel metal. These materials can be processed to aerogel or xerogel monolithic composite solids. High resolution transmission electron microscopy (HRTEM) of the dried energetic nanocomposites reveal that the metal oxide component consists of small (3-10 nm) clusters of Fe2O3 that are in intimate contact with ultra fine grain (UFG) similar to 25 nm diameter Al metal particles. HRTEM results also indicate that the Al particles have an oxide coating similar to5 nm thick. This value agrees well with analysis of pristine UFG Al powder and indicates that the sol-gel synthetic method and processing does not significantly perturb the fuel metal. Both qualitative and quantitative characterization has shown that these materials are indeed energetic. The materials described here are relatively insensitive to standard impact, spark, and friction tests. results of which will be presented. Qualitatively, it does appear that these energetic nanocomposites burn faster and an mon sensitive to thermal ignition than their conventional counterparts and that aerogel materials are more sensitive to ignition than xerogels. We believe that the sol-gel method will at the very least provide processing advantages over conventional methods in the areas of cost, purity, homogeneity, and safety and potentially yield energetic materials with interesting and special properties. (C) 2001 Published by Elsevier Science B.V. C1 Univ Calif Lawrence Livermore Natl Lab, Chem & Mat Sci Directorate, Livermore, CA 94550 USA. RP Tillotson, TM (reprint author), Univ Calif Lawrence Livermore Natl Lab, Chem & Mat Sci Directorate, POB 808 L-092, Livermore, CA 94550 USA. NR 25 TC 171 Z9 202 U1 6 U2 74 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 JUN 1 PY 2001 VL 285 IS 1-3 BP 338 EP 345 DI 10.1016/S0022-3093(01)00477-X PG 8 WC Materials Science, Ceramics; Materials Science, Multidisciplinary SC Materials Science GA 444QJ UT WOS:000169410800053 ER PT J AU Dinh, LN Cecala, CM Leckey, JH Balooch, M AF Dinh, LN Cecala, CM Leckey, JH Balooch, M TI The effects of moisture on LiD single crystals studied by temperature-programmed decomposition SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article AB Temperature-programmed decomposition (TPD) technique was performed on LiOH powders and LiD single crystals previously exposed to different moisture levels. Our results show that the LiOH decomposition process is rate-limited by an inward moving reaction front mechanism with an activation energy barrier of similar to 122-149 kJ/mol. The LiOH structure is stable even if kept at 320 K. However, LIOH structures formed on the surface of LiD single crystals during moisture exposure at low dosages may have multiple activation energy barriers, some of which may be much lower than 122 kJ/mol. The rate-limiting mechanism for the decomposition of LIOH structures with reduced activation energy barriers is consistent with a unimolecular nucleation model. We attribute the lowering of the activation energy barrier for the LiOH decomposition to the existence of sub-stoichiometric Li(OH), with x < 1 and cracks, broken bonds, and other disorders in the LIOH structures formed at low levels of moisture exposure. These defective LiOH structures may decompose significantly over many years of storage even at room temperature. At high moisture exposure levels, LiOH .H2O formation is observed. The release of H2O molecules from LiOH .H2O structure has small activation energy barriers in the range of 48-69 kJ/mol ann follows a unimolecular nucleation process. The loosely bonded H2O molecules in the LiOH .H2O structure can be easily pumped away at room temperature in a reasonable amount of time. Our experiments also suggest that handling LID single crystals at an elevated temperature of 340 K or more reduces the growth rate of LiOH and LiOH .H2O significantly. (C) 2001 Elsevier Science B.V. All rights reserved. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. Lockheed Martin Energy Syst, Oak Ridge, TN USA. RP Dinh, LN (reprint author), Univ Calif Lawrence Livermore Natl Lab, POB 808,L-350, Livermore, CA 94551 USA. NR 14 TC 30 Z9 34 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 JUN PY 2001 VL 295 IS 2-3 BP 193 EP 204 DI 10.1016/S0022-3115(01)00548-7 PG 12 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA 444RM UT WOS:000169413400007 ER PT J AU Miller, GK Petti, DA Varacalle, DJ Maki, JT AF Miller, GK Petti, DA Varacalle, DJ Maki, JT TI Consideration of the effects on fuel particle behavior from shrinkage cracks in the inner pyrocarbon layer SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article AB The fundamental design for a gas-cooled pebble bed reactor relies on an understanding of the behavior of coated particle fuel. The coating layers surrounding the fuel kernels in these spherical particles consist of pyrolytic carbon layers and a silicon carbide (SiC) layer. These coating layers act as a pressure vessel that retains fission product gases. A small percentage of fuel particles may fail during irradiation in the mode of a traditional pressure vessel failure. Fuel performance models used to predict particle behavior have traditionally been one-dimensional models that focus on this failure mechanism. Results of irradiation experiments, however, show that many more fuel particles fail than would be predicted by this mechanism alone. Post-irradiation examinations indicate that multi-dimensional effects, such as the presence of shrinkage cracks in the inner pyrolytic carbon layer (IPyC), contribute to these unexplained failures. Results of a study performed to evaluate the significance of cracking in the IPyC layer on behavior of a fuel particle are presented herein, which indicate that shrinkage cracks could contribute significantly to fuel particle failures. (C) 2001 Elsevier Science B.V. All rights reserved. C1 Idaho Natl Engn & Environm Lab, Idaho Falls, ID 83415 USA. RP Miller, GK (reprint author), Idaho Natl Engn & Environm Lab, POB 1625, Idaho Falls, ID 83415 USA. NR 12 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 JUN PY 2001 VL 295 IS 2-3 BP 205 EP 212 DI 10.1016/S0022-3115(01)00551-7 PG 8 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA 444RM UT WOS:000169413400008 ER PT J AU Raylman, RR Majewski, S Weisenberger, AG Popov, V Wojcik, R Kross, B Schreiman, JS Bishop, HA AF Raylman, RR Majewski, S Weisenberger, AG Popov, V Wojcik, R Kross, B Schreiman, JS Bishop, HA TI Positron emission mammography-guided breast biopsy SO JOURNAL OF NUCLEAR MEDICINE LA English DT Article DE breast biopsy; positron emission mammography; radionuclide guidance ID DENSITY; PSPMT; PET; AGE AB Positron emission mammography (PEM) is a technique to obtain planar images of the breast for detection of potentially cancerous, radiotracer-avid tumors. To increase the diagnostic accuracy of this method, use of minimally invasive methods (e,g., core biopsy) may be desirable for obtaining tissue samples from lesions detected with PEM. The purpose of this study was to test the capabilities of a novel method for performing PEM-guided stereotactic breast biopsies. Methods: The PEM system consisted of 2 square (10 x 10 cm) arrays of discrete scintillator crystals. The detectors were mounted on a stereotactic biopsy table. The stereotactic technique used 2 PEM images acquired at +/- 15 degrees and a new trigonometric algorithm. The accuracy and precision of the guidance method was tested by placement of small point sources of F-18 at known locations within the field of view of the imager. The calculated positions of the sources were compared with the known locations. In addition, simulated stereotactic biopsies of a breast phantom consisting of a 10-mm-diameter gelatin sphere containing a concentration of F-18-FDG consistent with that reported for breast cancer were performed. The simulated lesion was embedded in a 4-cm-thick slab of gelatin containing a commonly reported concentration of FDG, simulating a compressed breast (target-to-background ratio, approximately 8.5:1). An anthropomorphic torso phantom was used to simulate tracer uptake in the organs of a patient 1 h after a 370-MBq injection of FDG. Five trials of the biopsy procedure were performed to assess repeatability. Finally, a method for verifying needle positioning was tested. Results: The positions of the point sources were successfully calculated to within 0.6 mm of their true positions with a mean error of +/-0.4 mm. The biopsy procedures, including the method for verification of needle position, were successful in all 5 trials in acquiring samples from the simulated lesions. Conclusion: The success of this new technique shows its potential for guiding the biopsy of breast lesions optimally detected with PEM. C1 W Virginia Univ, Hlth Sci Ctr S, Ctr Adv Imaging, Dept Radiol, Morgantown, WV 26506 USA. Jefferson Lab, Detector Grp, Newport News, VA USA. RP Raylman, RR (reprint author), W Virginia Univ, Hlth Sci Ctr S, Ctr Adv Imaging, Dept Radiol, Radiol PET Box 9236, Morgantown, WV 26506 USA. FU NCI NIH HHS [CA82752-01] NR 16 TC 29 Z9 29 U1 0 U2 1 PU SOC NUCLEAR MEDICINE INC PI RESTON PA 1850 SAMUEL MORSE DR, RESTON, VA 20190-5316 USA SN 0161-5505 J9 J NUCL MED JI J. Nucl. Med. PD JUN PY 2001 VL 42 IS 6 BP 960 EP 966 PG 7 WC Radiology, Nuclear Medicine & Medical Imaging SC Radiology, Nuclear Medicine & Medical Imaging GA 439XN UT WOS:000169143000026 PM 11390563 ER PT J AU Kohn, SR Baden, SB AF Kohn, SR Baden, SB TI Parallel software abstractions for structured adaptive mesh methods SO JOURNAL OF PARALLEL AND DISTRIBUTED COMPUTING LA English DT Article ID REFINEMENT AB We describe and analyze parallelization techniques for the implementation of portable structured adaptive mesh applications on distributed memory parallel computers. Such methods are difficult to implement on parallel computers because they employ elaborate dynamic data structures to selectively capture localized irregular phenomena. Our infrastructure supports a set of layered abstractions that encapsulate low-level details of resource management, such as grid generation, interprocessor communication, and load balancing. Our layered design also provides the flexibility necessary to accommodate new applications and to fine-tune performance. This flexibility has enabled us to show that the uniformity restrictions imposed by a data parallel Fortran implementation (e.g., HPF) would significantly impact performance of structured adaptive mesh methods. We present computational results from eigenvalue computation arising in materials design. (C) 2001 Academic Press. C1 Lawrence Livermore Natl Lab, Ctr Appl Sci Comp, Livermore, CA 94550 USA. Univ Calif San Diego, Dept Comp Sci & Engn, La Jolla, CA 92093 USA. RP Lawrence Livermore Natl Lab, Ctr Appl Sci Comp, Livermore, CA 94550 USA. EM baden@cs.ucsd.edu NR 30 TC 7 Z9 7 U1 0 U2 1 PU ACADEMIC PRESS INC ELSEVIER SCIENCE PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0743-7315 EI 1096-0848 J9 J PARALLEL DISTR COM JI J. Parallel Distrib. Comput. PD JUN PY 2001 VL 61 IS 6 BP 713 EP 736 DI 10.1006/jpdc.2001.1700 PG 24 WC Computer Science, Theory & Methods SC Computer Science GA 442CF UT WOS:000169267100001 ER PT J AU Chen, MJ Rathke, JW AF Chen, MJ Rathke, JW TI Dimeric aggregates of five-coordinated methyl(phthalocyaninato)Rh(III): H-1 NMR evidence for staggered and slipped cofacial dimers SO JOURNAL OF PORPHYRINS AND PHTHALOCYANINES LA English DT Article DE phthalocyanine; rhodium; dimer; aggregate; conformation ID PHTHALOCYANINE AB The H-1 NMR spectra of the five-coordinated rhodium phthalocyanine complex Me(RPc)Rh(III) (1, RPc = dianion of 1,4,8,11,15,18,22,25-octa-n-pentylphthalocyanine) in toluene indicate that it exists as a discrete monomer at low concentrations. The complex forms a dimer aggregate reversibly in the concentration range of 2.6-10.2 mM at -90 < T < 22 degreesC. The dimerization constants at -60, -80, and -90 degreesC are 2.0 x 10(2), 5.7 x 10(2), and 1.0 x 10(3) M-1, respectively. In chloroform, aggregation of the complex occurs at similar to0.3 mM, reflecting the lower solvating power of chloroform for this complex. The H-1 NMR spectra of the chloroform solutions indicate that at concentrations greater than 1.0 mM, two discrete dimers in the ratio of 87:13 are reversibly formed. The H-1 NMR spectra of the major isomer, 2a, suggest that it is the 45 degrees -staggered cofacial dimer, a dimer with a D-4d symmetry. The H-1 NMR spectra of the minor isomer, 2b, suggest that it is a slipped cofacial dimer with a C-2h symmetry, which is formed by slipping a (RPc)Rh plane of the eclipsed dimer (a D-4h dimer) along a line connecting two opposing meso nitrogens of (RPc)Rh. Interestingly, the solution conformation of 2b is similar to that of the basic stacking unit found in the crystal structure of 1. Published in 2001 by John Wiley & Sons, Ltd. C1 Argonne Natl Lab, Div Chem Technol, Argonne, IL 60439 USA. RP Chen, MJ (reprint author), Argonne Natl Lab, Div Chem Technol, 9700 S Cass Ave, Argonne, IL 60439 USA. NR 18 TC 10 Z9 10 U1 1 U2 4 PU JOHN WILEY & SONS LTD PI W SUSSEX PA BAFFINS LANE CHICHESTER, W SUSSEX PO19 1UD, ENGLAND SN 1088-4246 J9 J PORPHYR PHTHALOCYA JI J. Porphyr. Phthalocyanines PD JUN PY 2001 VL 5 IS 6 BP 528 EP 536 DI 10.1002/jpp.359 PG 9 WC Chemistry, Multidisciplinary SC Chemistry GA 436PW UT WOS:000168945100007 ER PT J AU Nagasubramanian, G Doughty, D AF Nagasubramanian, G Doughty, D TI Improving the interfacial resistance in lithium cells with additives SO JOURNAL OF POWER SOURCES LA English DT Article; Proceedings Paper CT 22nd International Power Sources Symposium CY APR 09-11, 2001 CL MANCHESTER, ENGLAND SP AEA Technol Battery Syst Ltd, Batteries Int, British Telecom, CMP Batteries, DERA, Hawker Ltd, SAFT, Transport Res Lab, Ultralife Batteries (UK) Ltd, Varta Ltd DE lithium-ion cells; electrolyte additives; interfacial resistances ID LI-ION CELLS; ELECTROLYTES; IMPEDANCE; ENERGY; POWER AB Improved interfacial resistance was observed in lithium cells by the use of new additives. The additives, nitrile sucrose and nitrile cellulose and their lithium salts, were evaluated in polyvinylidene difluoride (PVDF) thin-film gelled electrolytes containing a mixture of ethylene carbonate (EC) and diethyl carbonate (DEC). The electrochemical properties of the films with and without the additives were measured as a function of temperature and compared. The interfacial resistance (R-in) of the films with the additives was significantly lower than that without the additives, especially at sub-ambient temperatures. For example, the R-in at -20 degreesC for the films with additives was around 7000 Ohm cm(2) and that for the films without the additives was > 20.000 Ohm cm(2).]Results obtained from using the additives in lithium-ion (Li-ion) cells show significant improvements in the low frequency resistance of the cells. (C) 2001 Published by Elsevier Science B.V. C1 Sandia Natl Labs, Dept Lithium Battery R&D 2521, Albuquerque, NM 87185 USA. RP Nagasubramanian, G (reprint author), Sandia Natl Labs, Dept Lithium Battery R&D 2521, Albuquerque, NM 87185 USA. NR 9 TC 14 Z9 25 U1 2 U2 6 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0378-7753 J9 J POWER SOURCES JI J. Power Sources PD JUN 1 PY 2001 VL 96 IS 1 BP 29 EP 32 DI 10.1016/S0378-7753(01)00498-0 PG 4 WC Chemistry, Physical; Electrochemistry; Energy & Fuels; Materials Science, Multidisciplinary SC Chemistry; Electrochemistry; Energy & Fuels; Materials Science GA 440KN UT WOS:000169174600007 ER PT J AU Butler, P Dunleavey, J Farber-DeAnda, M Moseley, P AF Butler, P Dunleavey, J Farber-DeAnda, M Moseley, P TI Performance of valve-regulated lead-acid batteries in real-world stationary applications - utility installations SO JOURNAL OF POWER SOURCES LA English DT Article; Proceedings Paper CT 22nd International Power Sources Symposium CY APR 09-11, 2001 CL MANCHESTER, ENGLAND SP AEA Technol Battery Syst Ltd, Batteries Int, British Telecom, CMP Batteries, DERA, Hawker Ltd, SAFT, Transport Res Lab, Ultralife Batteries (UK) Ltd, Varta Ltd DE lead-acid batteries/valve regulated; performance surveys AB A multi-phase project to investigate the reliability of valve-regulated lead-acid (VRLA) batteries in the field has been conducted by US industry and government research organizations. The focus of the study has been to characterize the relationships between VRLA technologies, service conditions, performance, and field failures. Two surveys were conducted. one of VRLA end users, and the other of VRLA manufacturers. Data from end users were obtained for over 56,000 telecom and utility installations representing over 740,000 cells. Seven manufacturers participated in the study. Preliminary correlations between utility end-user data, manufacturer information, and battery reliability have been developed and will be reported. Data for telecommunications installations will be reported in a separate publication when completed. (C) 2001 Published by Elsevier Science B.V. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. Energet Inc, Washington, DC 20024 USA. Int Lead Zinc Res Org, Res Triangle Pk, NC 27709 USA. RP Butler, P (reprint author), Sandia Natl Labs, POB 5800,MS0613, Albuquerque, NM 87185 USA. NR 3 TC 1 Z9 1 U1 0 U2 1 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0378-7753 J9 J POWER SOURCES JI J. Power Sources PD JUN 1 PY 2001 VL 96 IS 1 BP 94 EP 101 DI 10.1016/S0378-7753(01)00713-3 PG 8 WC Chemistry, Physical; Electrochemistry; Energy & Fuels; Materials Science, Multidisciplinary SC Chemistry; Electrochemistry; Energy & Fuels; Materials Science GA 440KN UT WOS:000169174600017 ER PT J AU Sowder, AG Clark, SB Fjeld, RA AF Sowder, AG Clark, SB Fjeld, RA TI The impact of mineralogy in the U(VI)-Ca-PO4 system on the environmental availability of uranium SO JOURNAL OF RADIOANALYTICAL AND NUCLEAR CHEMISTRY LA English DT Article; Proceedings Paper CT 5th International Conference on Methods and Applications of Radioanalytical Chemistry (MARC-V) CY APR 09-14, 2000 CL KAILUA-KONA, HAWAII SP Amer Nucl Soc Top ID CONTAMINATED SOILS; AQUEOUS-SOLUTIONS; MOBILITY; ZINC; EXTRACTABILITY; SPECIATION; EXTRACTION; SOLUBILITY; ADSORPTION; CADMIUM AB Kinetic dissolution studies were conducted on four prominent U-Ca-PO4 minerals (metaschoepite, becquerelite, chemikovite and metaautunite). Synthetic samples were contacted with four extractants (acetic acid, deionized water, EDTA and sodium bicarbonate) at room temperature at two concentrations, 100 mM and 1 mM. Dissolution progress was monitored by periodic sampling for dissolved U, and dissolution rates were obtained from fits to a three term exponential model. Significant Variations were observed in the rate and extent of dissolution among the minerals examined. The uranyl phosphates chemikovite and metaautunite proved resistant to dissolution in non-carbonate systems, with dissolution half-times of days to weeks in 100 mM systems and weeks to years in 1 mM systems. In contrast, the uranyl oxide hydrates schoepite and becquerelite were solubilized over much shorter time scales. While 100 mM bicarbonate was successful in dissolving U in all forms, dissolution rates varied among the four minerals. Overall, EDTA was the least sensitive to a 100 to 1 mM drop in its concentration in its solubilization of all four mineral phases, underscoring the importance of organic complexation for the environmental mobility of uranium. C1 Univ Georgia, Savannah River Ecol Lab, Aiken, SC 29802 USA. Washington State Univ, Dept Chem, Pullman, WA 99164 USA. Clemson Univ, Dept Environm Engn & Sci, Clemson, SC 29634 USA. RP Sowder, AG (reprint author), Univ Georgia, Savannah River Ecol Lab, Aiken, SC 29802 USA. NR 43 TC 30 Z9 30 U1 1 U2 8 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0236-5731 J9 J RADIOANAL NUCL CH JI J. Radioanal. Nucl. Chem. PD JUN PY 2001 VL 248 IS 3 BP 517 EP 524 DI 10.1023/A:1010602225070 PG 8 WC Chemistry, Analytical; Chemistry, Inorganic & Nuclear; Nuclear Science & Technology SC Chemistry; Nuclear Science & Technology GA 445EF UT WOS:000169444600002 ER PT J AU Kaplan, DI Serkiz, SM AF Kaplan, DI Serkiz, SM TI Quantification of thorium and uranium sorption to contaminated sediments SO JOURNAL OF RADIOANALYTICAL AND NUCLEAR CHEMISTRY LA English DT Article; Proceedings Paper CT 5th International Conference on Methods and Applications of Radioanalytical Chemistry (MARC-V) CY APR 09-14, 2000 CL KAILUA-KONA, HAWAII SP Amer Nucl Soc Top ID PARTICLES AB Desorption tests, using a sequential extraction method, were used to characterize and quantify thorium and uranium sorption to contaminated wetland sediments collected from the Department of Energy's Savannah River Site located in South Carolina. In situ distribution coefficients, or K-d values (K-d = C-solid/C-liquid) were determined. Sequential extraction data were used to assign solid-phase radionuclide concentrations (C-solid) that, by definition, should represent only the reversibly sorbed fraction. A series of selective and sequential extractions was used to determine desorption K-d values. Thorium K-d values ranged from 115 to 2255 ml/g. Uranium K-d values ranged from 170 to 6493 ml/g. Compared to sorption K-d values, these desorption K-d values were appreciably greater because they captured the "aging" process of the radionuclides with the sediment, making the radionuclide mon refractory. Compared to nonsite-specific data, these in situ K-d values improved accuracy, were more defensible, and removed unnecessary conservatism for subsequent transport and risk calculations. Additional tests were conducted to provide geochemical information relevant for selecting appropriate remediation technologies for the contaminated site. Thorium and uranium were associated with labile fractions and were not concentrated with the smaller sediment particles. These findings suggest that phytoremediation or heap leaching, and not soil washing, are viable remediation approaches for this site. C1 Westinghouse Savannah River Co, Savannah River Lab, Aiken, SC 29808 USA. RP Kaplan, DI (reprint author), Westinghouse Savannah River Co, Savannah River Lab, Aiken, SC 29808 USA. NR 15 TC 31 Z9 35 U1 3 U2 20 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0236-5731 J9 J RADIOANAL NUCL CH JI J. Radioanal. Nucl. Chem. PD JUN PY 2001 VL 248 IS 3 BP 529 EP 535 DI 10.1023/A:1010606325979 PG 7 WC Chemistry, Analytical; Chemistry, Inorganic & Nuclear; Nuclear Science & Technology SC Chemistry; Nuclear Science & Technology GA 445EF UT WOS:000169444600004 ER PT J AU Eaton, GF Smith, DK AF Eaton, GF Smith, DK TI Aged nuclear explosive melt glass: Radiography and scanning electron microscope analyses documenting radionuclide distribution and glass alteration SO JOURNAL OF RADIOANALYTICAL AND NUCLEAR CHEMISTRY LA English DT Article; Proceedings Paper CT 5th International Conference on Methods and Applications of Radioanalytical Chemistry (MARC-V) CY APR 09-14, 2000 CL KAILUA-KONA, HAWAII SP Amer Nucl Soc Top ID DISSOLUTION; WASTE AB Assessment of the long-term performance of nuclear melt glass under saturated conditions provides insight into factors controlling radionuclide release into groundwater. Melt glass samples were collected from an underground nuclear detonation cavity at the Nevada Test Site that was in contact with groundwater for more than 10 years. The samples were made into thin sections and the distribution of alpha-activity mapped using CR-39 plastic detectors. The melt glass is visually heterogeneous and the results of the alpha-track radiography indicate that the highest alpha-activity is associated with areas of dark colored glass. Analyses of the thin sections by alpha-spectrometry show the prominent actinide species to be Pu-238, Pu-239,Pu-240 and Am-241. Scanning electron microprobe analysis of the bulk glass shows conspicuous alteration layers lining internal Vesicle surfaces in the glass. X-ray diffraction patterns for the alteration phases are consistent with clay mineral compositions. Glass dissolution models indicate these layers are too thick to have formed at ambient temperatures over the IO year period in which they remained in a saturated environment. This implies the alteration layers likely formed at temperatures higher than ambient during cooling of the cavity following the underground detonation. Mobilization of this clay alteration layer as colloidal particles in groundwater represents a potential source of actinide release into the environment. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Eaton, GF (reprint author), Univ Calif Lawrence Livermore Natl Lab, POB 808, Livermore, CA 94550 USA. NR 23 TC 3 Z9 3 U1 1 U2 5 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0236-5731 J9 J RADIOANAL NUCL CH JI J. Radioanal. Nucl. Chem. PD JUN PY 2001 VL 248 IS 3 BP 543 EP 547 DI 10.1023/A:1010610426887 PG 5 WC Chemistry, Analytical; Chemistry, Inorganic & Nuclear; Nuclear Science & Technology SC Chemistry; Nuclear Science & Technology GA 445EF UT WOS:000169444600006 ER PT J AU Espinosa, G Silva, RJ AF Espinosa, G Silva, RJ TI Alpha-particle analysis of a triple isotope Pu-239-Am-241-Cm-244 source by nuclear track methodology SO JOURNAL OF RADIOANALYTICAL AND NUCLEAR CHEMISTRY LA English DT Article; Proceedings Paper CT 5th International Conference on Methods and Applications of Radioanalytical Chemistry (MARC-V) CY APR 09-14, 2000 CL KAILUA-KONA, HAWAII SP Amer Nucl Soc Top ID DETECTOR AB This work presents a new approach using nuclear track in solids methodology (NTSM) for the energy analysis of alpha-particles. This method is based on the quantitative relationship between the energy deposited in the polycarbonate by the geometrical parameters of the developed track after the chemical etching. We used separated calibrated sources of Pu-239 and Am-241 and a mixed source with Pu-239, Am-241 and Cm-244. CR-39 polycarbonate manufactured by Landauer Inc.(R) was selected as the detector material, because of its excellent response to these energies. The chemical etching was done in two steps: (a) pre-etching to avoid the irregularities on the surface of the material, and (b) chemical etching to develop the track. In both processes the temperature and pH of the solution need to be very controlled. The geometrical characteristics of the formed tracks were analyzed automatically by Digital Image System. The results show a distribution of track diameters as a function of the energies analyzed analogous to the pulses produced on the conventional electronic detection system. C1 Univ Nacl Autonoma Mexico, Inst Fis, Mexico City 01000, DF, Mexico. Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Espinosa, G (reprint author), Univ Nacl Autonoma Mexico, Inst Fis, Apdo Postal 20-364, Mexico City 01000, DF, Mexico. NR 11 TC 0 Z9 0 U1 0 U2 0 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0236-5731 J9 J RADIOANAL NUCL CH JI J. Radioanal. Nucl. Chem. PD JUN PY 2001 VL 248 IS 3 BP 575 EP 578 DI 10.1023/A:1010622703206 PG 4 WC Chemistry, Analytical; Chemistry, Inorganic & Nuclear; Nuclear Science & Technology SC Chemistry; Nuclear Science & Technology GA 445EF UT WOS:000169444600012 ER PT J AU Espinosa, G Silva, RJ AF Espinosa, G Silva, RJ TI Mapping of transuranic elements in soil by unclear track methodology SO JOURNAL OF RADIOANALYTICAL AND NUCLEAR CHEMISTRY LA English DT Article; Proceedings Paper CT 5th International Conference on Methods and Applications of Radioanalytical Chemistry (MARC-V) CY APR 09-14, 2000 CL KAILUA-KONA, HAWAII SP Amer Nucl Soc Top ID CR-39 AB This work presents an alternative method to map the distribution of transuranic elements, which is characterized by its simplicity in both implementation and instrumentation. The method is based on the interaction of alpha particles in polymeric materials and the formation of tracks, which become visible after chemical etching. Nuclear track detectors are placed on the soil in order to evaluate the distribution of the radioactive material and its relative intensity for transuranic contaminants. CR-39 polycarbonate was used as a nuclear track detector in this study. Chemical etching was done with a 6.25M KOH solution in a closed system for 16 hours. The readings were performed in an automatic system using digital image analysis. The results show the distribution of the contaminants and their location, identifying the zones with large intensities. This method is attractive for use in areas contaminated with alpha particles, and specially transuranic elements, because it involves in situ measurements, generates very low amounts of radioactive waste, and the detectors are easily handled. C1 Univ Nacl Autonoma Mexico, Inst Fis, Mexico City 01000, DF, Mexico. Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Espinosa, G (reprint author), Univ Nacl Autonoma Mexico, Inst Fis, Apdo Postal 20-364, Mexico City 01000, DF, Mexico. NR 9 TC 0 Z9 0 U1 0 U2 0 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0236-5731 J9 J RADIOANAL NUCL CH JI J. Radioanal. Nucl. Chem. PD JUN PY 2001 VL 248 IS 3 BP 579 EP 582 DI 10.1023/A:1010603620044 PG 4 WC Chemistry, Analytical; Chemistry, Inorganic & Nuclear; Nuclear Science & Technology SC Chemistry; Nuclear Science & Technology GA 445EF UT WOS:000169444600013 ER PT J AU Swindle, DW Pearson, RL Wogman, NA Krey, PW AF Swindle, DW Pearson, RL Wogman, NA Krey, PW TI Screening of potential sites for undeclared nuclear facilities in environmental monitoring for nuclear proliferation SO JOURNAL OF RADIOANALYTICAL AND NUCLEAR CHEMISTRY LA English DT Article; Proceedings Paper CT 5th International Conference on Methods and Applications of Radioanalytical Chemistry (MARC-V) CY APR 09-14, 2000 CL KAILUA-KONA, HAWAII SP Amer Nucl Soc Top AB The sensitivity of environmental sampling and analysis for the estimated atmospheric concentrations of radionuclides in effluents from clandestine nuclear facilities may require many sampling sites and exorbitant costs to monitor such large areas. An assessment has been made of the key factors necessary to support the operation of a nuclear facility, e.g., the existence of a nearby transportation network, main electrical power supply, and population centers. Screening, the subject of this paper, evaluates how cartographic data and satellite imagery can be used to identify areas most capable of supporting undeclared nuclear operations. As a result, large geographical areas can be eliminated from environmental monitoring and sampling. This leads to reduced costs, a reduction in the number of sampling sites required, and a reduction in the overall level of effort required to accomplish effective environmental monitoring. The screening methodology and techniques are described and examples given. C1 EG&G, Littleton, CO 80120 USA. CH2M Hill, Englewood, CO 80112 USA. Pacific NW Natl Lab, Natl Secur Div, Richland, WA 99352 USA. RP Swindle, DW (reprint author), EG&G, 7921 SouthPk Plaza, Littleton, CO 80120 USA. NR 3 TC 1 Z9 1 U1 0 U2 0 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0236-5731 J9 J RADIOANAL NUCL CH JI J. Radioanal. Nucl. Chem. PD JUN PY 2001 VL 248 IS 3 BP 599 EP 604 DI 10.1023/A:1010611921861 PG 6 WC Chemistry, Analytical; Chemistry, Inorganic & Nuclear; Nuclear Science & Technology SC Chemistry; Nuclear Science & Technology GA 445EF UT WOS:000169444600017 ER PT J AU Wogman, NA Wigmosta, MS Swindle, DW Krey, PW AF Wogman, NA Wigmosta, MS Swindle, DW Krey, PW TI Wide-area aquatic sampling and analysis for the detection of nuclear proliferation SO JOURNAL OF RADIOANALYTICAL AND NUCLEAR CHEMISTRY LA English DT Article; Proceedings Paper CT 5th International Conference on Methods and Applications of Radioanalytical Chemistry (MARC-V) CY APR 09-14, 2000 CL KAILUA-KONA, HAWAII SP Amer Nucl Soc Top AB Nuclear proliferation signature radionuclides can be delivered to the aquatic environs via direct liquid discharges or atmospheric routes. The candidate radionuclides for detection are H-3, Sr-90, Nb-95, Zr-95, Tc-99, Ru-106, Sb-125, I-129, Cs-131, Cs-137, Ce-144, Pm-147, U-Nat, U-238, U-235, Np-237, Pu-239, Pu-240, and Pu-241. The criteria for detection are the limits of radionuclide analysis, the nature and variability of background concentrations, and the transport characteristics between the source and sample site. The type of sample to be taken is determined by the signature radionuclides sorption on/in the media sampled. Non-sorbing radionuclides such as H-3, Tc-99, and I-129 are in the water, whereas the Pu radionuclides are in the transported sediments. Results are discussed for monthly releases of radionuclides such as Sr-90, Cs-137, and Pu-239 for variable flow-rate conditions with typical backgrounds and typical detection limits. C1 Pacific NW Natl Lab, Natl Secur Div, Richland, WA 99352 USA. EG&G Sci & Engn Div, Littleton, CO 80120 USA. RP Wogman, NA (reprint author), Pacific NW Natl Lab, Natl Secur Div, POB 999, Richland, WA 99352 USA. NR 5 TC 3 Z9 3 U1 0 U2 1 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0236-5731 J9 J RADIOANAL NUCL CH JI J. Radioanal. Nucl. Chem. PD JUN PY 2001 VL 248 IS 3 BP 611 EP 615 DI 10.1023/A:1010616022770 PG 5 WC Chemistry, Analytical; Chemistry, Inorganic & Nuclear; Nuclear Science & Technology SC Chemistry; Nuclear Science & Technology GA 445EF UT WOS:000169444600019 ER PT J AU Reeder, PL Bowyer, TW McIntyre, JI Pitts, WK AF Reeder, PL Bowyer, TW McIntyre, JI Pitts, WK TI Determination of Xe-131m and Xe-133m in the presence of Xe-133g via combined beta-spectroscopy and delayed coincidence SO JOURNAL OF RADIOANALYTICAL AND NUCLEAR CHEMISTRY LA English DT Article; Proceedings Paper CT 5th International Conference on Methods and Applications of Radioanalytical Chemistry (MARC-V) CY APR 09-14, 2000 CL KAILUA-KONA, HAWAII SP Amer Nucl Soc Top ID TEST BAN TREATY; RADIOXENON AB The International Monitoring System for the Comprehensive Nuclear-Test-Ban Treaty will include measurements of Xe fission products. Pacific Northwest National Laboratory has developed an automated system far separating Xe from air which detects Xe fission products using a beta-gamma counting system for Xe-131m, Xe-133m, Xe-133g, and Xe-135g. Betas and conversion electrons are detected in a plastic scintillation cell containing the Xe sample. Gamma and X-rays are detected in a NaI(Tl) scintillation detector which surrounds the plastic scintillator sample cell. Two-dimensional pulse-height spectra of gamma-energy versus beta-energy are obtained. The plastic scintillator spectrum in coincidence with the 31-keV X-rays from Xe-131m. Xe-133m, and Xe-133g is a complex mixture of conversion electrons and betas. A new technique to simultaneously measure the delayed coincidence (T-1/2 = 6.27 ns) between beta-particles from Xe-133g and conversion electrons depopulating the 81-keV state in Cs-133 is being developed. This technique allows separation of the Xe-133g beta spectrum from the conversion electrons due to Xe-131m and Xe-133m and uniquely quantifies all three nuclides. C1 Pacific NW Natl Lab, Richland, WA 99352 USA. RP Reeder, PL (reprint author), Pacific NW Natl Lab, Richland, WA 99352 USA. RI McIntyre, Justin/P-1346-2014 OI McIntyre, Justin/0000-0002-3706-4310 NR 8 TC 5 Z9 5 U1 0 U2 2 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0236-5731 J9 J RADIOANAL NUCL CH JI J. Radioanal. Nucl. Chem. PD JUN PY 2001 VL 248 IS 3 BP 617 EP 622 DI 10.1023/A:1010668006840 PG 6 WC Chemistry, Analytical; Chemistry, Inorganic & Nuclear; Nuclear Science & Technology SC Chemistry; Nuclear Science & Technology GA 445EF UT WOS:000169444600020 ER PT J AU McIntyre, JI Abel, KH Bowyer, TW Hayes, JC Heimbigner, TR Panisko, ME Reeder, PL Thompson, RC AF McIntyre, JI Abel, KH Bowyer, TW Hayes, JC Heimbigner, TR Panisko, ME Reeder, PL Thompson, RC TI Measurements of ambient radioxenon levels using the automated radioxenon sampler/analyzer (ARSA) SO JOURNAL OF RADIOANALYTICAL AND NUCLEAR CHEMISTRY LA English DT Article; Proceedings Paper CT 5th International Conference on Methods and Applications of Radioanalytical Chemistry (MARC-V) CY APR 09-14, 2000 CL KAILUA-KONA, HAWAII SP Amer Nucl Soc Top ID GAMMA AB The Pacific Northwest National Laboratory has developed an Automated Radioxenon Sampler/Analyzer (ARSA) in support of the Comprehensive Nuclear-Test-Ban-Treaty (CTBT) to measure four radioxenon isotopes: Xe-131m, Xe-133m, Xe-133g, and Xe-135g. This system uses a beta-gamma coincidence counting detector to produce two-dimensional plots of gamma-energy versus beta-energy. Betas and conversion electrons (CE) are detected in a cylindrical plastic scintillation cell and gamma and X-rays are detected in a surrounding NaI(TI) scintillation detector. The ARSA has been field tested at several locations to measure the radioxenon concentrations. Most recently it has been deployed at the Institut fur Atmospharische Radioaktivitat in Freiburg, Germany. During the first 4 months of 2000 the measured Xe-133 concentrations have varied between 0.0 +/-0.1 and 110 +/- 10 mBq/m(3) air. The longer lived Xe-131m (T-1/2 = 11.9 d) and Short lived Xe-135 (T-1/2 = 9.1 h) have also been detected in small quantities, while Xe-133m concentrations have been consistent with zero. Minimum detectable concentration (MDC) calculations for Xe-133g fell well below the 1 mBq per standard-cubic-meter of air requirement adopted by the CTBT preparatory Commission.(1) A description of the radioxenon detector, the concentration and MDC calculations and preliminary results of the field test in Germany are presented. C1 Pacific NW Natl Lab, NSD, Radiol & Chem Sci Grp, Richland, WA 99352 USA. RP McIntyre, JI (reprint author), Pacific NW Natl Lab, NSD, Radiol & Chem Sci Grp, MS In-P8-20,Battelle Blvd, Richland, WA 99352 USA. RI McIntyre, Justin/P-1346-2014 OI McIntyre, Justin/0000-0002-3706-4310 NR 13 TC 25 Z9 29 U1 0 U2 6 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0236-5731 J9 J RADIOANAL NUCL CH JI J. Radioanal. Nucl. Chem. PD JUN PY 2001 VL 248 IS 3 BP 629 EP 635 DI 10.1023/A:1010672107749 PG 7 WC Chemistry, Analytical; Chemistry, Inorganic & Nuclear; Nuclear Science & Technology SC Chemistry; Nuclear Science & Technology GA 445EF UT WOS:000169444600022 ER PT J AU Miley, HS Arthur, RJ Lepel, EA Pratt, SL Thomas, CW AF Miley, HS Arthur, RJ Lepel, EA Pratt, SL Thomas, CW TI Evaluation of fission product isotopes for field or laboratory detection SO JOURNAL OF RADIOANALYTICAL AND NUCLEAR CHEMISTRY LA English DT Article; Proceedings Paper CT 5th International Conference on Methods and Applications of Radioanalytical Chemistry (MARC-V) CY APR 09-14, 2000 CL KAILUA-KONA, HAWAII SP Amer Nucl Soc Top AB An International Monitoring System (IMS) is being created to monitor the Comprehensive Nuclear-Test-Ban Treaty (CTBT). Radionuclide aerosols will be monitored to provide positive proof of an atmospheric explosion In addition, a group of laboratories will perform quality assurance and confirmatory analyses of samples of interest. The field and laboratory systems will perform gamma-ray spectrometric analysis of air filters. While laboratories may undertake additional analysis such as chemical separation and beta counting, the scope of the work reported here is to make evaluations with respect only to gamma-ray spectrometry. Activation products have not been completely considered and are shaded with uncertainty, from the probability of escape from an underground test and the dependence on the sub-surface elemental composition. C1 Pacific NW Lab, Richland, WA 99352 USA. RP Miley, HS (reprint author), Pacific NW Lab, 1 Battelle Blvd, Richland, WA 99352 USA. NR 6 TC 2 Z9 2 U1 0 U2 4 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0236-5731 J9 J RADIOANAL NUCL CH JI J. Radioanal. Nucl. Chem. PD JUN PY 2001 VL 248 IS 3 BP 651 EP 656 DI 10.1023/A:1010628325496 PG 6 WC Chemistry, Analytical; Chemistry, Inorganic & Nuclear; Nuclear Science & Technology SC Chemistry; Nuclear Science & Technology GA 445EF UT WOS:000169444600025 ER PT J AU Hofstetter, KJ Beals, DM Halverson, JE Villa-Aleman, E Hayes, DW AF Hofstetter, KJ Beals, DM Halverson, JE Villa-Aleman, E Hayes, DW TI Law enforcement tools available at the Savannah River Site SO JOURNAL OF RADIOANALYTICAL AND NUCLEAR CHEMISTRY LA English DT Article; Proceedings Paper CT 5th International Conference on Methods and Applications of Radioanalytical Chemistry (MARC-V) CY APR 09-14, 2000 CL KAILUA-KONA, HAWAII SP Amer Nucl Soc Top ID TRITIUM AB A number of nuclear technologies developed and applied at the Savannah River Site in support of nuclear weapons material production and environmental remediation can be applied to problems in law enforcement. Techniques and equipment for high-sensitivity analyses of samples are available to identify and quantify trace elements and establish origins and histories of forensic evidence removed from crime scenes. While some of these capabilities are available at local crime laboratories, state-of-the-art equipment and breakthroughs in analytical techniques are continually being developed at DOE laboratories. Extensive experience with the handling of radioactive samples at the DOE labs minimizes the chances of cross-contamination of evidence received from law enforcement. In addition to high-sensitivity analyses, many of the field techniques developed for use in a nuclear facility can assist law enforcement personnel in detecting illicit materials and operations, in retrieving of pertinent evidence and in surveying crime scenes. Some of these tools include chemical sniffers, hand-held detectors, thermal imaging, etc. In addition, mobile laboratories can be deployed to a crime scene to provide field screening of potential evidence. A variety of portable sensors can be deployed on vehicle, aerial, surface or submersible platforms to assist in the location of pertinent evidence or illicit operations. Several specific nuclear technologies available to law enforcement and their potential uses are discussed. C1 Westinghouse Savannah River Co, Savannah River Technol Ctr, Aiken, SC 29808 USA. RP Hofstetter, KJ (reprint author), Westinghouse Savannah River Co, Savannah River Technol Ctr, Aiken, SC 29808 USA. NR 8 TC 0 Z9 0 U1 0 U2 1 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0236-5731 J9 J RADIOANAL NUCL CH JI J. Radioanal. Nucl. Chem. PD JUN PY 2001 VL 248 IS 3 BP 683 EP 687 DI 10.1023/A:1010636627313 PG 5 WC Chemistry, Analytical; Chemistry, Inorganic & Nuclear; Nuclear Science & Technology SC Chemistry; Nuclear Science & Technology GA 445EF UT WOS:000169444600029 ER PT J AU Seymour, R Hull, CD Crawford, T Coyne, B Bliss, M Craig, RA AF Seymour, R Hull, CD Crawford, T Coyne, B Bliss, M Craig, RA TI Portal, freight and vehicle monitor performance using scintillating glass fiber detectors for the detection of plutonium in the Illicit Trafficking Radiation Assessment Program SO JOURNAL OF RADIOANALYTICAL AND NUCLEAR CHEMISTRY LA English DT Article; Proceedings Paper CT 5th International Conference on Methods and Applications of Radioanalytical Chemistry (MARC-V) CY APR 09-14, 2000 CL KAILUA-KONA, HAWAII SP Amer Nucl Soc Top AB Neutron-sensitive scintillating glass fiber sensors provide several advantages over neutron-sensitive gas-tubes for plutonium detection and surveillance. Large area detectors and higher effective neutron capture density provide significant improvements in sensitivity versus cost. The glass sensors offer a wide dynamic counting range, fast response time, no transport hazard, greater operator safety and lower micro-phonic susceptibility relative to conventional He-3 and (BF3)-B-10 sensors. We report on the testing methods used in Illicit Trafficking Radiation Assessment Program and our experience in evaluating the performance of the portal, freight and vehicle monitors for customs applications employing these new sensors. Results of false and real alarm tests and distribution tests are presented and compared to previous Monte Carlo and first principle calculations. These earlier calculations determined the detection limits for neutron glass panels used for continuous monitoring of special nuclear materials. Assumptions used in the model assumed a nominal background count rate for neutrons of 0.010 n.cm(-2) s(-1), an intrinsic neutron efficiency of 20% and an alarm set point of 5.2 sigma representing one false alarm per month. Measured neutron data taken with Cf-252 and several gamma ray sources confirm the calculated data. Calculations assume an unshielded source and are conservative because they do not include environmental improvements in neutron economy. The results demonstrate that these systems are capable of reliably detecting special nuclear materials (SNM) and other radionuclides within a few seconds. C1 NucSafe LLC, Clinton, TN 37716 USA. Pacific NW Natl Lab, Richland, WA 99352 USA. RP Seymour, R (reprint author), NucSafe LLC, 241 Tracy Allison Dr, Clinton, TN 37716 USA. RI Bliss, Mary/G-2240-2012 OI Bliss, Mary/0000-0002-7565-4813 NR 13 TC 2 Z9 3 U1 0 U2 1 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0236-5731 J9 J RADIOANAL NUCL CH JI J. Radioanal. Nucl. Chem. PD JUN PY 2001 VL 248 IS 3 BP 699 EP 705 DI 10.1023/A:1010692712292 PG 7 WC Chemistry, Analytical; Chemistry, Inorganic & Nuclear; Nuclear Science & Technology SC Chemistry; Nuclear Science & Technology GA 445EF UT WOS:000169444600032 ER PT J AU Reeder, PL Bowyer, SM AF Reeder, PL Bowyer, SM TI Neutron/gamma discrimination in LiBaF3 scintillator SO JOURNAL OF RADIOANALYTICAL AND NUCLEAR CHEMISTRY LA English DT Article; Proceedings Paper CT 5th International Conference on Methods and Applications of Radioanalytical Chemistry (MARC-V) CY APR 09-14, 2000 CL KAILUA-KONA, HAWAII SP Amer Nucl Soc Top ID CRYSTALS AB The detection of neutrons in the presence of significant gamma-radiation is often required in arms control, material accountability, and nuclear smuggling scenarios as well as in basic nuclear research. The new scintillator material LiBaF3 offers the possibility of measuring neutron count rates and energy spectra simultaneously while measuring gamma-count rates and spectra using a single detector. These capabilities derive from the fact that LiBaF3 exhibits a very fast core-valence luminescence under gamma-irradiation whereas this component is missing under neutron irradiation. Relatively simple pulse shape analysis techniques can be used to obtain excellent neutron/gamma discrimination. We present our current results illustrating these capabilities. C1 Pacific NW Natl Lab, Richland, WA 99352 USA. RP Reeder, PL (reprint author), Pacific NW Natl Lab, Richland, WA 99352 USA. NR 7 TC 14 Z9 14 U1 2 U2 4 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0236-5731 J9 J RADIOANAL NUCL CH JI J. Radioanal. Nucl. Chem. PD JUN PY 2001 VL 248 IS 3 BP 707 EP 711 DI 10.1023/A:1010644829130 PG 5 WC Chemistry, Analytical; Chemistry, Inorganic & Nuclear; Nuclear Science & Technology SC Chemistry; Nuclear Science & Technology GA 445EF UT WOS:000169444600033 ER PT J AU Noshkin, VE Robison, WL Brunk, JA Jokela, TA AF Noshkin, VE Robison, WL Brunk, JA Jokela, TA TI An evaluation of activated bismuth isotopes in environmental samples from the former Western Pacific Proving Grounds SO JOURNAL OF RADIOANALYTICAL AND NUCLEAR CHEMISTRY LA English DT Article; Proceedings Paper CT 5th International Conference on Methods and Applications of Radioanalytical Chemistry (MARC-V) CY APR 09-14, 2000 CL KAILUA-KONA, HAWAII SP Amer Nucl Soc Top ID FALLOUT; BI-207 AB Bi-207 (T-1/2 = 32.2 y) was generated by activation of weapons material during a few "clean" nuclear tests at the U.S. Western Pacific Proving Grounds of Enewetak and Bikini Atolls. The radionuclides first appeared in the Enewetak environment during 1958 and in the environment of Bikini during 1956. Crater sediments from Bikini with high levels of Bi-207 were analyzed by gamma-spectrometry in an attempt to determine the relative concentrations of Bi-208 (T = 3.68.10(5) y). The bismuth isotopes were probably generated during the "clean", 9.3 Mt Poplar test held on 7/12/58. The atom ratio of Bi-208 to Bi-207 (R value) ranges from similar to 12 to over 200 in sections of core sediments from the largest nuclear crater at Bikini atoll. The presence of bismuth in the device is suggested to account for R values in excess of 10. C1 Univ Calif Lawrence Livermore Natl Lab, Hlth & Ecol Sci Div, Livermore, CA 94551 USA. RP Noshkin, VE (reprint author), Univ Calif Lawrence Livermore Natl Lab, Hlth & Ecol Sci Div, L-286,POB 808, Livermore, CA 94551 USA. NR 33 TC 5 Z9 5 U1 1 U2 2 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0236-5731 J9 J RADIOANAL NUCL CH JI J. Radioanal. Nucl. Chem. PD JUN PY 2001 VL 248 IS 3 BP 741 EP 750 DI 10.1023/A:1010605115018 PG 10 WC Chemistry, Analytical; Chemistry, Inorganic & Nuclear; Nuclear Science & Technology SC Chemistry; Nuclear Science & Technology GA 445EF UT WOS:000169444600038 ER PT J AU Leon-Escamilla, EA Corbett, JD AF Leon-Escamilla, EA Corbett, JD TI Hydrogen impurity effects. A(5)Tt(3) intermetallic compounds between A = Ca, Sr, Ba, Eu and Tt = Si, Ge, Sn with Cr5B3-like structures that are stable both as binary and as ternary hydride and fluoride phases SO JOURNAL OF SOLID STATE CHEMISTRY LA English DT Article DE hydrogen impurities; Cr5B3-type structures; alkaline-earth metal triels A(5)Tr(3); structures of Cr5B3-type phases; synthesis of Cr5B3-type compounds; interstitial binding of H-, F- ID CRYSTAL-STRUCTURE; ZINTL-PHASES; METALS; STABILIZATION; TRIGERMANIDE; SYSTEM AB All of the binary systems Ca, Sr, Ba, or Eu (A) with Tt (tetrel) = Si or Ge as well as Sr-Sn form both binary Cr5B3-type A(5)Tt(3) phases and the corresponding ternary hydrides with stuffed Cr5B3- (Ca5Sn3F-) type structures. All of those tested, Ca-Si, Be-Si, Ca-Ge, also yield the isotypic A(5)Tt(3)F(x) phases. The tetragonal structures of Ca5Si3, Ca5Si3F0.42, Sr5Si3, Eu5Si3Hx, Ca5Ge3, Ca5Ge3Hx, Ca5Ge3F0.66 (I4/mcm, No. 140) and of Ba5Si3F0.16 (P4/ncc, Ba5Si3-type) were refined from single-crystal X-ray diffraction data. The interstitial H, P atoms are bound in a constricted tetrahedral (A(2+))(4) cavity in the Cr5B3-type heavy atom structure, which can be described ideally as (A(2+))(5)(Tt(2))(6-)(Tt)(4-). Many of 14 previous reports of the phases reported here mere apparently hydrides according to lattice constant differences or, for Sr5Si3, the fractional coordinates of Sr2 about the tetrahedral site. An articulated model is developed that allows description of the relationship between the dimensions of the tetrahedral interstitial site and the cation cavity about Tt(2) and for some matrix effects in this structure type. The model suggests limitations on the stability of these binary A(5)Tt(3) compounds for the heavier tetrels, as observed. The resistivities of Ca5Ge3 and Ca5Ce3Hx are both characteristic of poor metals, and Pauli-like magnetic susceptibilities are exhibited by Ca5Ge3, Ca5Ge3Hx, Ca5Ge3F0.66, Sr5Ge3, and Sr5Sn3. The characteristic ideal Ti-2(6-) dimers are evidently not realistic descriptions for these phases; rather at least some of the pi*(4) electrons in the dimers are delocalized in a conduction band. This effect appears to be greater in two europium salts. Bond lengths of dimers in the Ca-Si and Ca-Ge families appear to shorten slightly in three instances of their oxidation to form the hydride or the fluoride, as might be expected. (C) 2001 Academic Press. C1 Iowa State Univ Sci & Technol, Dept Chem, Ames, IA 50011 USA. Iowa State Univ Sci & Technol, Ames Lab, DOE, Ames, IA 50011 USA. RP Corbett, JD (reprint author), Iowa State Univ Sci & Technol, Dept Chem, Ames, IA 50011 USA. NR 48 TC 49 Z9 49 U1 2 U2 16 PU ACADEMIC PRESS INC PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0022-4596 J9 J SOLID STATE CHEM JI J. Solid State Chem. PD JUN PY 2001 VL 159 IS 1 BP 149 EP 162 DI 10.1006/jssc.2001.9144 PG 14 WC Chemistry, Inorganic & Nuclear; Chemistry, Physical SC Chemistry GA 443YG UT WOS:000169370700022 ER PT J AU Felmy, AR Cho, H Rustad, JR Mason, MJ AF Felmy, AR Cho, H Rustad, JR Mason, MJ TI An aqueous thermodynamic model for polymerized silica species to high ionic strength SO JOURNAL OF SOLUTION CHEMISTRY LA English DT Article DE silica; aqueous; thermodynamics; electrolytes; polynuclear; polymerization; Pitzer ion-interaction parameters ID NUCLEAR MAGNETIC-RESONANCE; POTASSIUM SILICATE; POLYSILICATE FORMATION; MOLECULAR-DYNAMICS; ACIDITY CONSTANTS; ORTHOSILICIC ACID; NATURAL-WATERS; SI-29; NMR; ALUMINUM(III) AB The development of an aqueous thermodynamic model for polymerized silica species is presented, which is valid for high ionic strengths and high dissolved silica concentration (similar to0.1 m) at low temperature (22-25 degreesC). The model is based on the Pitzer equations and has been parameterized from solubility, electromotive force (emf), and nuclear magnetic resonance (NMR) data. The description of the silica speciation reactions at high dissolved silica and basic conditions (pH > 10) required the inclusion of monomeric, dimeric, trimeric (linear, cyclic, and substituted), tetrameric (linear and cyclic), and hexameric (prismatic) species. The standard state equilibrium constants for the Formation of these species, as well as the necessary Pitzer ion-interaction parameters to describe the ionic strength dependence of the formation reactions were determined. C1 Pacific NW Natl Lab, Richland, WA 99352 USA. RP Felmy, AR (reprint author), Pacific NW Natl Lab, POB 999,MS K8-96, Richland, WA 99352 USA. NR 40 TC 74 Z9 74 U1 2 U2 24 PU KLUWER ACADEMIC/PLENUM PUBL PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 0095-9782 J9 J SOLUTION CHEM JI J. Solut. Chem. PD JUN PY 2001 VL 30 IS 6 BP 509 EP 525 DI 10.1023/A:1010382701742 PG 17 WC Chemistry, Physical SC Chemistry GA 454MQ UT WOS:000169976700002 ER PT J AU Hastings, MB AF Hastings, MB TI Eigenvalue distribution in the self-dual non-hermitian ensemble SO JOURNAL OF STATISTICAL PHYSICS LA English DT Article DE Non-hermitian; random matrix; one-component plasma ID ONE-COMPONENT PLASMA; RANDOM-MATRIX THEORY AB We consider an ensemble of self-dual matrices with arbitrary complex entries. This ensemble is closely related to a previously defined ensemble of anti-symmetric matrices with arbitrary complex entries. We study the two-level correlation functions numerically. Although no evidence of non-monotonicity is found in the real space correlation function, a definite shoulder is found. On the analytical side, we discuss the relationship between this ensemble and the beta = 4 two-dimensional one-component plasma, and also argue that this ensemble, combined with other ensembles, exhausts the possible universality classes in nonhermitian random matrix theory. This argument is based on combining the method of hermitization of Feinberg and Zee with Zirnbauer's classification of ensembles in terms of symmetric spaces. C1 Los Alamos Natl Lab, CNLS, Los Alamos, NM 87545 USA. Princeton Univ, Dept Phys, Princeton, NJ 08544 USA. RP Hastings, MB (reprint author), Los Alamos Natl Lab, CNLS, B258, Los Alamos, NM 87545 USA. NR 18 TC 8 Z9 8 U1 0 U2 0 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 JUN PY 2001 VL 103 IS 5-6 BP 903 EP 913 DI 10.1023/A:1010356821471 PG 11 WC Physics, Mathematical SC Physics GA 457BL UT WOS:000170117200012 ER PT J AU Chambers, DH Gautesen, AK AF Chambers, DH Gautesen, AK TI Time reversal for a single spherical scatterer SO JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA LA English DT Article ID BAFFLED PLANAR PISTON; TRANSIENT FIELD; OPERATOR AB We show that the time reversal operator for a planar time reversal mirror (TRM) can have up to four distinct eigenvalues with a small spherical acoustic scatterer. Each eigenstate represents a resonance between the TRM and an induced scattering moment of the sphere. Their amplitude distributions on the TRM are orthogonal superpositions of the radiation patterns from a monopole and up to three orthogonal dipoles. The induced monopole moment is associated with the compressibility contrast between the sphere and the medium, while the dipole moments are associated with density contrast. The number of eigenstates is related to the number of orthogonal orientations of each induced multipole. For hard spheres (glass, metals) the contribution of the monopole moment to the eigenvalues is much greater than that of the dipole moments, leading to a single dominant eigenvalue. The other eigenvalues are much smaller, making it unlikely multiple eigenvalues could have been observed in previous experiments using hard materials. However, for soft materials such as wood, plastic, or air bubbles the eigenvalues are comparable in magnitude and should be observable. The presence of multiple eigenstates breaks the one-to-one correspondence between eigenstates and distinguishable scatterers discussed previously by Prada and Fink [Wave Motion 20, 151-163 (1994)]. However, eigenfunctions from separate scatterers would have different phases for their eigenfunctions, potentially restoring the ability to distinguish separate scatterers. Since relative magnitudes of the eigenvalues for a single scatterer are governed by the ratio of the compressibility contrast to the density contrast, measurement of the eigenvalue spectrum would provide information on the composition of the scatterer. (C) 2001 Acoustical Society of America. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. Iowa State Univ Sci & Technol, Dept Math, Ames, IA 50011 USA. RP Chambers, DH (reprint author), Univ Calif Lawrence Livermore Natl Lab, POB 808,L-154, Livermore, CA 94551 USA. NR 14 TC 45 Z9 46 U1 0 U2 2 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 JUN PY 2001 VL 109 IS 6 BP 2616 EP 2624 DI 10.1121/1.1368404 PG 9 WC Acoustics; Audiology & Speech-Language Pathology SC Acoustics; Audiology & Speech-Language Pathology GA 443CU UT WOS:000169322800010 PM 11425102 ER PT J AU Tuttle, BA Yang, P Gieske, JH Voigt, JA Scofield, TW Zeuch, DH Olson, WR AF Tuttle, BA Yang, P Gieske, JH Voigt, JA Scofield, TW Zeuch, DH Olson, WR TI Pressure-induced phase transformation of controlled-porosity Pb(Zr0.95Ti0.05)O-3 ceramics SO JOURNAL OF THE AMERICAN CERAMIC SOCIETY LA English DT Article ID PORE AB Chemically prepared Pb(Zr0.95Ti0.05)O-3 (PZT 95/5) ceramics were fabricated with a range of different porosity levels, while grain size was held constant, by systematic additions of added organic pore former (Avicel), Use of Avicel in amounts ranging from 0 to 4.0 wt% resulted in fired ceramic densities that ranged from 97.3% to 82.3%, Hydrostatic-pressure-induced ferroelectric (FE) to antiferroelectric (AFE) phase transformations were substantially more diffuse and occurred at lower hydrostatic pressures with increasing porosity, An similar to 12 MPa decrease in hydrostatic transformation pressure per volume percent added porosity was observed, The decrease in transformation pressure with decreasing density was quantitatively consistent with the calculated macroscopic stress required to achieve a specific volumetric macrostrain (0.40%). This strain was equivalent to experimentally measured macrostrain for FE-to-AFE transformation. The macroscopic stress levels were calculated using measured bulk modulus values that decreased from 84 to 46 GPa as density decreased from 97.3% to 82.3%, Good agreement between calculated and measured values of FE-to-AFE transformation stress was obtained for ceramics fired at 1275 degrees and 1345 degreesC. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Tuttle, BA (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. NR 13 TC 49 Z9 53 U1 3 U2 21 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 JUN PY 2001 VL 84 IS 6 BP 1260 EP 1264 PG 5 WC Materials Science, Ceramics SC Materials Science GA 441AX UT WOS:000169209800011 ER PT J AU Dickey, EC Fan, XD Pennycook, SJ AF Dickey, EC Fan, XD Pennycook, SJ TI Structure and chemistry of yttria-stabilized cubic-zirconia symmetric tilt grain boundaries SO JOURNAL OF THE AMERICAN CERAMIC SOCIETY LA English DT Article ID ATOMIC-STRUCTURE; IMAGE-RECONSTRUCTION; ELECTRON-MICROSCOPY; SCATTERED ELECTRONS; HIGH-RESOLUTION; THIN-FILMS; ENERGY; SEGREGATION; CERAMICS; METALS AB The atomic structures of two symmetric [001] tilt grain boundaries in yttria-stabilized cubic-zirconia, Sigma5 (310) and near-Sigma 13 (510), are studied by Z-contrast scanning transmission electron microscopy. Both boundaries are composed of periodic arrays of highly symmetric structural units, with a distinct unit for each boundary, Oxygen K-edge electron energy-loss spectra show that the oxygen coordination is similar between the bulk and grain boundary, indicating that oxygen ions within the grain boundary reside in distorted tetrahedral sites. Atomic models of the grain boundaries are proposed that are consistent with the experimental data. The core structures are different from previously studied metal or oxide grain boundaries and are unique to the fluorite structure, Yttrium segregation to the grain boundaries is also investigated by electron energy-loss spectroscopy. Yttrium is found to segregate preferentially to the Sigma5 grain boundary, and the spatial distribution of the segregation layer is confined to within 1 nm of the boundary plane. C1 Univ Kentucky, Dept Chem & Mat Engn, Lexington, KY 40506 USA. Oak Ridge Natl Lab, Div Solid State, Oak Ridge, TN 37831 USA. RP Dickey, EC (reprint author), Penn State Univ, Dept Mat Sci & Engn, University Pk, PA 16802 USA. RI Dickey, Elizabeth/A-3368-2011 OI Dickey, Elizabeth/0000-0003-4005-7872 NR 42 TC 76 Z9 76 U1 2 U2 25 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 JUN PY 2001 VL 84 IS 6 BP 1361 EP 1368 PG 8 WC Materials Science, Ceramics SC Materials Science GA 441AX UT WOS:000169209800027 ER PT J AU Tikare, V Miodownik, MA Holm, EA AF Tikare, V Miodownik, MA Holm, EA TI Three-dimensional simulation of grain growth in the presence of mobile pores SO JOURNAL OF THE AMERICAN CERAMIC SOCIETY LA English DT Article ID COMPUTER-SIMULATION; BOUNDARY MOTION; POTTS-MODEL; SEPARATION; PARTICLES; KINETICS AB A kinetic, three-dimensional Monte Carte model for simulating grain growth in the presence of mobile pores is presented. The model was used to study grain growth and pore migration by surface diffusion in an idealized geometry that ensures constant driving force for grain growth. The driving forces, pore size, and pore mobilities were varied to study their effects on grain-boundary mobility and grain growth. The simulations captured a variety of complex behaviors, including reduced grain-boundary velocity due to pore drag that has been predicted by analytical theories, The model is capable of treating far more complex geometries, including polycrystals. We present the capabilities of this model and discuss its limitations. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. Natl Univ Ireland Univ Coll Dublin, Dept Mech Engn, Dublin, Ireland. RP Tikare, V (reprint author), Kings Coll London, Dept Mech Engn, London WC2R 2LS, England. RI Holm, Elizabeth/S-2612-2016 OI Holm, Elizabeth/0000-0003-3064-5769 NR 19 TC 23 Z9 23 U1 0 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 JUN PY 2001 VL 84 IS 6 BP 1379 EP 1385 PG 7 WC Materials Science, Ceramics SC Materials Science GA 441AX UT WOS:000169209800030 ER PT J AU Houston, PL Cosofret, BR Dixit, A Dylewski, SM Geiser, JD Mueller, JA Wilson, RJ Pisano, PJ Westley, MS Lorenz, KT Chandler, DW AF Houston, PL Cosofret, BR Dixit, A Dylewski, SM Geiser, JD Mueller, JA Wilson, RJ Pisano, PJ Westley, MS Lorenz, KT Chandler, DW TI Product imaging studies of photodissociation and bimolecular reaction dynamics SO JOURNAL OF THE CHINESE CHEMICAL SOCIETY LA English DT Article; Proceedings Paper CT 4th Asian International Seminars on Atomic and Moleuclar Physics CY OCT 13-18, 2000 CL TAIPEI, TAIWAN DE photo dissociation; rotational energy transfer; ozone; sulfur dioxide; nitric oxide ID DIFFERENTIAL CROSS-SECTIONS; FINE-STRUCTURE TRANSITIONS; STATE; SCATTERING; OZONE; SPECTROSCOPY; COLLISIONS; NO(X(2)PI); BEAM; SO2 AB This paper briefly reviews recent progress in product imaging studies of photodissociation and bimolecular reaction dynamics. The SO2 + hv --> SO((3)Sigma (-)) + O(P-3(2)) channel in the ultraviolet photo dissociation of sulfur dioxide at photolysis wavelengths between 202 and 207 mn has been studied using resonance-enhanced multiphoton ionization with time-of-flight product imaging. These imaging experiments allowed the determination of the vibrational populations of the SO((3)Sigma (-)) fragment at several wavelengths. A change in the vibrational populations occurs from a distribution where most of the population is in v = 0 for wavelengths shorter than 203.0 nm to one where the population is more evenly distributed for longer wavelength dissociation. The changes in the internal energy distribution are attributed to participation of two different predissociation mechanisms. Our data suggest that the predissociation mechanism below 203.0 nm involves an avoided crossing with the repulsive singlet state (1)A(1). The O-3(X (1)A(1)) + hv --> O(2p, P-3(J)) + O-2(X (3)Sigma (-)(g)) product channel in the UV photodissociation of ozone has been investigated at photolysis wavelengths of 226, 230, 233, 234, 240, and 266 nm. At 226, 230, 233, 234, and 240 nm, the yield of the O-2 product in vibrational states greater than or equal to 26 was 11.8 +/- 1.9%, 11.5 +/- 1.2%, 8.2 +/- 2.0, 4.7 +/- 1.8, and 0.6 +/- 0.1%, respectively. Two-dimensional ion counting product imaging has also been used to determine the bond energy for the dissociation of jet-cooled O-3 into O(D-1) + O-2((1)Delta). The bond dissociation energy into O(D-1) + O-2((1)Delta) was found to be 386.59 +/- 0.04 kJ/mol. The standard heat of formation of O-3 is calculated to be -144.31 +/- 0.14 kJ/mol. State-selective differential cross sections for rotationally inelastic scattering of NO (J(i) = 0.5, 1.5, F --> J(f) = 2.5-12.5, F-1 and J(f) = 1.5-9.5, F-2) from He and D-2 measured by crossed molecular beam ion imaging are reported. The images typically exhibit a single broad rotational rainbow maximum that shifts from the forward to the backward scattering direction with increasing DeltaJ. The angle of the rainbow maximum was lower at a given DeltaJ for D-2 than for He as a collision partner. At a collision energy of similar to 500 cm(-1), primarily the repulsive part of the potential surface is probed, which can be modeled with a 2D hard ellipse potential. This model for rotationally inelastic scattering is shown to qualitatively match the experimental differential cross sections. A more advanced CEPA PES for NO + He does not give substantially better agreement with the experiment. C1 Cornell Univ, Dept Chem & Chem Biol, Ithaca, NY 14853 USA. Cornell Univ, Dept Appl & Engn Phys, Ithaca, NY 14853 USA. Sandia Natl Labs, Combust Res Facil, Livermore, CA USA. RP Houston, PL (reprint author), Cornell Univ, Dept Chem & Chem Biol, Ithaca, NY 14853 USA. NR 26 TC 5 Z9 5 U1 1 U2 7 PU CHINESE CHEM SOC PI TAIPEI PA PO BOX 609, TAIPEI 10099, TAIWAN SN 0009-4536 J9 J CHIN CHEM SOC-TAIP JI J. Chin. Chem. Soc. PD JUN PY 2001 VL 48 IS 3 SI SI BP 309 EP 318 PG 10 WC Chemistry, Multidisciplinary SC Chemistry GA 465XW UT WOS:000170616100007 ER PT J AU Reilly, JJ Johnson, JR Vogt, T Adzic, GD Zhu, Y McBreen, J AF Reilly, JJ Johnson, JR Vogt, T Adzic, GD Zhu, Y McBreen, J TI Properties of Li nanocomposite electrode materials prepared via hydrogen-driven, solid-state, metallurgical reactions SO JOURNAL OF THE ELECTROCHEMICAL SOCIETY LA English DT Article ID LITHIUM; BATTERIES; OXIDE AB This paper discusses the ex situ preparation of Li nanocomposite materials for use as Li battery anodes. The syntheses involve high-temperature, hydrogen-driven, solid-state reactions consisting of alloy disproportionation and metathetical transformations. The following systems are described, LiAlH4/SnO, LiAlH4/SiO2, and LiH/SnO, as well as pertinent electrochemical properties of their nanocomposite products. The properties of nanoscale LiAl particles produced by the decomposition and subsequent disproportionation of LiAlH4 are also discussed. Electrochemical experiments were carried out using Li metal as the anode. The possible extension of the process to appropriate, precursor intermetallic compounds is also examined. (C) 2001 The Electrochemical Society. C1 Brookhaven Natl Lab, Upton, NY 11973 USA. RP Reilly, JJ (reprint author), Brookhaven Natl Lab, Upton, NY 11973 USA. RI Vogt, Thomas /A-1562-2011 OI Vogt, Thomas /0000-0002-4731-2787 NR 21 TC 3 Z9 4 U1 1 U2 4 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 JUN PY 2001 VL 148 IS 6 BP A636 EP A641 DI 10.1149/1.1372217 PG 6 WC Electrochemistry; Materials Science, Coatings & Films SC Electrochemistry; Materials Science GA 439RU UT WOS:000169131500021 ER PT J AU Mawdsley, JR Halloran, JW AF Mawdsley, JR Halloran, JW TI The effect of residual carbon on the phase stability of LaPO4 at high temperatures SO JOURNAL OF THE EUROPEAN CERAMIC SOCIETY LA English DT Article DE carbon; chemical properties; composites; hot pressing; LaPO4 ID FIBROUS MONOLITHIC CERAMICS; OXIDE-OXIDE COMPOSITES; CARBOTHERMAL REDUCTION; BEHAVIOR; MICROSTRUCTURE; FRACTURE; MONAZITE; ALUMINA; AL2O3 AB Samples containing LaPO4 and polymeric binders were heated or hot-pressed in oxygen-poor environments to temperatures as high as 1585 degreesC. Carbon analysis, powder X-ray diffraction and thermogravimetric analysis revealed that the residual carbon from the binders caused the LaPO4 to decompose into a lanthanum-rich phosphate compound, La3PO7, or a lanthanum oxide, La2O3, at temperatures above 750 degreesC. These results agree with thermodynamic data, indicating that the driving force responsible for this carbothermic reduction reaction is the free energy of formation of P2O5, which is higher than the Free energy of formation of CO above 750 degreesC. It was also observed that this phenomenon would be detrimental to composites of LaPO4 and Al2O3, because LaAl11O18 and LaAlO3 were found to form at the interface, unless the samples were annealed in air after binder burnout. (C) 2001 Elsevier Science Ltd. All rights reserved. C1 Univ Michigan, Dept Mat Sci & Engn, Ann Arbor, MI 48019 USA. RP Mawdsley, JR (reprint author), Argonne Natl Lab, ETP CMT Blg 205,9700 S Cass Ave, Argonne, IL 60439 USA. RI Halloran, John /G-9210-2011 NR 23 TC 8 Z9 8 U1 0 U2 5 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0955-2219 J9 J EUR CERAM SOC JI J. European Ceram. Soc. PD JUN PY 2001 VL 21 IS 6 BP 751 EP 757 DI 10.1016/S0955-2219(00)00263-6 PG 7 WC Materials Science, Ceramics SC Materials Science GA 427VT UT WOS:000168426700009 ER PT J AU Fincke, JR Haggard, DC Swank, WD AF Fincke, JR Haggard, DC Swank, WD TI Particle temperature measurement in the thermal spray process SO JOURNAL OF THERMAL SPRAY TECHNOLOGY LA English DT Article DE diagnostics; particle temperature ID PLASMA; PARAMETERS; VELOCITY; SIZE AB Particle temperature is a fundamental parameter in the thermal spray process. The measurement of particle temperature usually relies on the measurement of the radiance of the hot, incandescent, particles in two or more wavelength or color bands. Measurement techniques can be categorized as single particle and ensemble methods. Single particle methods use high-speed pyrometry to estimate the temperature of individual particles. The mean and standard deviation of the particle temperature distribution can then be obtained from observations of sufficient numbers of individual particles. Ensemble methods observe Large numbers of particles simultaneously and yield an estimated mean temperature directly, but cannot provide information on the shape or width of the particle temperature distribution. Both techniques have inherent errors, strengths, and limitations that are examined and discussed. C1 Idaho Natl Engn & Environm Lab, Idaho Falls, ID 83415 USA. RP Fincke, JR (reprint author), Idaho Natl Engn & Environm Lab, Idaho Falls, ID 83415 USA. NR 28 TC 40 Z9 40 U1 1 U2 8 PU ASM INTERNATIONAL PI MATERIALS PARK PA SUBSCRIPTIONS SPECIALIST CUSTOMER SERVICE, MATERIALS PARK, OH 44073-0002 USA SN 1059-9630 J9 J THERM SPRAY TECHN JI J. Therm. Spray Technol. PD JUN PY 2001 VL 10 IS 2 BP 255 EP 266 DI 10.1361/105996301770349358 PG 12 WC Materials Science, Coatings & Films SC Materials Science GA 448HV UT WOS:000169622200005 ER PT J AU Wan, YP Gupta, V Deng, Q Sampath, S Prasad, V Williamson, R Fincke, JR AF Wan, YP Gupta, V Deng, Q Sampath, S Prasad, V Williamson, R Fincke, JR TI Modeling and visualization of plasma spraying of functionally graded materials and its application to the optimization of spray conditions SO JOURNAL OF THERMAL SPRAY TECHNOLOGY LA English DT Article DE modeling; FGM; plasma spray AB This paper presents a simulation and visualization system for plasma spraying of functionally graded materials (FGM), The recently modified CFD code, LAVA-P, that incorporates a well-verified model for plasma gas flow and chemistry is employed. The particle movement and its trajectory are described within a Lagrangian formulation by considering drag as the major driving force, and the particle melting, evaporation, and resolidification are considered using a recently developed model for particle-flame interaction. In addition to the noncontinuum and variable property effects associated with high-temperature plasma, the effects of particle evaporation on particle momentum and heat transfer are also taken into account. Calculations are performed for NiCrAlY and ZrO2 powders for a wide range of size distributions. The influences of power levels and flow rate of H-2 on plasma flow field and, hence, on the particle velocity and temperature are investigated, The predicted velocity and temperature fields agree well with the measurements under similar spraying conditions, With the help of a special in-house built process animation and visualization algorithm, the powder injection conditions, such as the number of injectors, injector location, and injection velocity, are investigated and can be optimized to obtain coatings with a specified distribution of different species. C1 SUNY Stony Brook, Ctr Thermal Spray Res, Stony Brook, NY 11794 USA. SUNY Stony Brook, Proc Modeling Lab, Stony Brook, NY 11794 USA. Idaho Natl Engn & Environm Lab, Idaho Falls, ID 83415 USA. RP Wan, YP (reprint author), SUNY Stony Brook, Ctr Thermal Spray Res, Stony Brook, NY 11794 USA. OI Williamson, Richard/0000-0001-7734-3632 NR 13 TC 13 Z9 13 U1 1 U2 5 PU ASM INTERNATIONAL PI MATERIALS PARK PA SUBSCRIPTIONS SPECIALIST CUSTOMER SERVICE, MATERIALS PARK, OH 44073-0002 USA SN 1059-9630 J9 J THERM SPRAY TECHN JI J. Therm. Spray Technol. PD JUN PY 2001 VL 10 IS 2 BP 382 EP 389 DI 10.1361/105996301770349475 PG 8 WC Materials Science, Coatings & Films SC Materials Science GA 448HV UT WOS:000169622200017 ER PT J AU DeJong, ES DeBerardino, TM Brooks, DE Nelson, BJ Campbell, AA Bottoni, CR Pusateri, AE Walton, RS Guymon, CH McManus, AT AF DeJong, ES DeBerardino, TM Brooks, DE Nelson, BJ Campbell, AA Bottoni, CR Pusateri, AE Walton, RS Guymon, CH McManus, AT TI Antimicrobial efficacy of external fixator pins coated with a lipid stabilized hydroxyapatite/chlorhexidine complex to prevent pin tract infection in a goat model SO JOURNAL OF TRAUMA-INJURY INFECTION AND CRITICAL CARE LA English DT Article; Proceedings Paper CT 60th Annual Meeting of the American-Association-for-the-Surgery-of-Trauma CY OCT 11-15, 2000 CL SAN ANTONIO, TEXAS SP Amer Assoc Surg Trauma DE external fixation; pin infection; hydroxyapatite; chlorhexidine ID UNCOATED PINS; ANTIBIOTICS; CHLORHEXIDINE AB Background: Pin tract infection is a common complication of external fixation, An antiinfective external fixator pin might help to reduce the incidence of pin tract infection and improve pin fixation, Methods: stainless steel and titanium external fixator pins, with and without a lipid stabilized hydroxgiapatite/chlorhexidine coating, were evaluated in a goat model. Two pins contaminated with an identifiable Staphylococcus aureus strain were inserted into each tibia of 12 goats. The pin sites were examined daily. On day 14, the animals were killed, and the pin tips cultured. Insertion and extraction torques were measured. Results: Infection developed in 100% of uncoated pins, whereas coated pins demonstrated 4.2% infected, 12.5% colonized, and the remainder, 83.3%, had no growth (p < 0.01). Pin coating decreased the percent loss of fixation torque Over uncoated pins (p = 0.04), Conclusion: These results demonstrate that the lipid stabilized hydroxyapatite/chlorhexidine coating was successful in decreasing infection and improving fixation of external fixator pins. C1 Brooke Army Med Ctr, Orthopaed Surg Serv, Ft Sam Houston, TX 78234 USA. Brooke Army Med Ctr, Extrem Trauma Study Branch, Ft Sam Houston, TX USA. Brooke Army Med Ctr, Div Microbiol, Ft Sam Houston, TX USA. Brooke Army Med Ctr, USA Inst Surg Res, Ft Sam Houston, TX USA. Brooke Army Med Ctr, Orthopaed Surg Serv, Ft Sam Houston, TX USA. Eisenhower Army Med Ctr, Orthopaed Surg Serv, Ft Gordon, GA USA. Pacific NW Natl Lab, Dept Mat Sci, Richland, WA USA. Tripler Army Med Ctr, Orthopaed Surg Serv, Honolulu, HI 96859 USA. RP DeJong, ES (reprint author), Brooke Army Med Ctr, Orthopaed Surg Serv, 3851 Roger Brooke Dr, Ft Sam Houston, TX 78234 USA. OI DeBerardino, Thomas/0000-0002-7110-8743 NR 27 TC 52 Z9 58 U1 0 U2 4 PU LIPPINCOTT WILLIAMS & WILKINS PI PHILADELPHIA PA 530 WALNUT ST, PHILADELPHIA, PA 19106-3621 USA SN 0022-5282 J9 J TRAUMA JI J. Trauma-Injury Infect. Crit. Care PD JUN PY 2001 VL 50 IS 6 BP 1008 EP 1013 PG 6 WC Critical Care Medicine; Surgery SC General & Internal Medicine; Surgery GA 442HD UT WOS:000169278400009 PM 11426113 ER PT J AU Hull, JR Phelan, PE AF Hull, JR Phelan, PE TI The cold reality of power - Advances in cryogenic refrigeration are spurring superconductivity applications. SO MECHANICAL ENGINEERING LA English DT Article C1 Argonne Natl Lab, Thermal & Electromech Sect, Div Energy Technol, Argonne, IL 60439 USA. Arizona State Univ, Dept Mech & Aerosp Engn, Tempe, AZ 85287 USA. RP Hull, JR (reprint author), Argonne Natl Lab, Thermal & Electromech Sect, Div Energy Technol, Argonne, IL 60439 USA. NR 0 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 0025-6501 J9 MECH ENG JI Mech. Eng. PD JUN PY 2001 VL 123 IS 6 BP 54 EP 57 PG 4 WC Engineering, Mechanical SC Engineering GA 439GW UT WOS:000169103400022 ER PT J AU Biggs, MW Eiselein, JE AF Biggs, MW Eiselein, JE TI Suppression of immune surveillance in melanoma SO MEDICAL HYPOTHESES LA English DT Article ID IMMATURE DENDRITIC CELLS; CYCLOPHOSPHAMIDE; CANCER; TUMORS; MICE AB Numerous reports of IL-10 cytokine secretion by tumor infiltrating cells indicate there is suppression of immune surveillance within the milieu of many melanomas. In this paper we have outlined the suppressor system that best fits the published data. The regulatory system is composed of CD4+ T-lymphocytes which have been activated and programmed to secrete Th2 cytokines. Initially these cells do not secrete cytokines, but subsequently they enter an IL-10 secretory phase as a result of T-T cell interaction. After activation, Th1 programmed T-cells express MHC class II molecules and B7 second signals. When these Th1 T-cells express MHC II molecules containing 'self' polypeptides coupled with faulty B7-H1 second signals they are subject to inactivation by Th2 T-cells. If this system can be inactivated, immunotherapy of melanoma will be more successful. If an antigen can be discovered that stimulates sensitized Th2 T-cells without stimulating Th1 T-cells, this antigen, followed with cyclophosphamide, can be used to destroy the Th2 T-cells in the course of both active and passive immunotherapy. Solubilized MHC II molecules with appropriate 'self' polypeptides should qualify as such an antigen. We postulate such an antigen can be prepared using poliovirus 1 (Sabin) to lyse melanoma tissue cultures. (C) 2001 Harcourt Publishers Ltd. C1 Lawrence Livermore Natl Lab, Dept Hlth Serv, Livermore, CA 94550 USA. RP Biggs, MW (reprint author), Lawrence Livermore Natl Lab, Dept Hlth Serv, 7000 East Ave, Livermore, CA 94550 USA. NR 15 TC 11 Z9 13 U1 0 U2 2 PU CHURCHILL LIVINGSTONE PI EDINBURGH PA JOURNAL PRODUCTION DEPT, ROBERT STEVENSON HOUSE, 1-3 BAXTERS PLACE, LEITH WALK, EDINBURGH EH1 3AF, MIDLOTHIAN, SCOTLAND SN 0306-9877 J9 MED HYPOTHESES JI Med. Hypotheses PD JUN PY 2001 VL 56 IS 6 BP 648 EP 652 DI 10.1054/mehy.2000.1211 PG 5 WC Medicine, Research & Experimental SC Research & Experimental Medicine GA 447MM UT WOS:000169577200010 PM 11399114 ER PT J AU Williams, PT AF Williams, PT TI Health effects resulting from exercise versus those from body fat loss SO MEDICINE AND SCIENCE IN SPORTS AND EXERCISE LA English DT Article; Proceedings Paper CT Symposium on Dose-Response Issues Concerning Physical Activity and health CY OCT 11-15, 2000 CL ONTARIO, CANADA DE cardiorespiratory fitness; physical activity; CHD risk; cardiovascular disease; public health recommendations; dose-response; exercise; epidemiology; relative risk; HDL-cholesterol; triglycerides; lipoproteins ID CORONARY HEART-DISEASE; HIGH-DENSITY-LIPOPROTEIN; MIDDLE-AGED MEN; TIME PHYSICAL-ACTIVITY; ALL-CAUSE MORTALITY; MODERATELY OVERWEIGHT MEN; FACTOR INTERVENTION TRIAL; NATIONAL RUNNERS HEALTH; UNITED-STATES RAILROAD; HARVARD ALUMNI HEALTH AB Objective: The purpose of this review was to assess whether body weight confounds the relationships between physical activity and its health benefits. Methods: The review includes 80 reports from population-based studies (Evidence Category C) of physical activity or fitness and cardiovascular disease (CVD) or coronary heart disease (CHD). Results: Eleven of 64 reports on activity found no relationship between physical activity and disease. Of the remaining 53 reports, 11 did not address the possible confounding effects of body weight, nine cited reasons that weight differences should not explain their observed associations, and 33 statistically adjusted for weight (as required). Only three of these changed their associations from significant to nonsignificant when adjusted. Ten of 16 reports on cardiorespiratory fitness and CHD or CVD used statistical adjustment, and none of these changed their findings to nonsignificant. Population studies show that vigorously active individuals also have higher high-density lipoprotein (HDL)-cholesterol concentration, a major risk factor for CHD and CVD, than sedentary individuals when statistically adjusted for weight. In contrast, intervention studies, which relate dynamic changes in weight and HDL, suggest that adjustment for weight loss largely eliminates the increase in HDL-cholesterol in sedentary men who begin exercising vigorously. Adjusting the cross-sectional HDL-cholesterol differences for the dynamic effects of weight loss eliminates most of the HDL-cholesterol difference between active and sedentary men. Conclusion: Population studies show that the lower incidence of CHD and CVD and higher HDL of fit, active individuals are not because of lean, healthy individuals choosing to be active (i.e., self-selection bias). Nevertheless, metabolic processed associated weight loss may be primarily responsible for the HDL differences between active and sedentary men, and possibly also their differences in CHD and CVD. C1 Lawrence Berkeley Lab, Div Life Sci, Berkeley, CA 94720 USA. RP Williams, PT (reprint author), Lawrence Berkeley Lab, Div Life Sci, 1 Cyclotron Rd, Berkeley, CA 94720 USA. FU NHLBI NIH HHS [HL-55640, HL-58621] NR 141 TC 17 Z9 18 U1 1 U2 4 PU LIPPINCOTT WILLIAMS & WILKINS PI PHILADELPHIA PA 530 WALNUT ST, PHILADELPHIA, PA 19106-3621 USA SN 0195-9131 J9 MED SCI SPORT EXER JI Med. Sci. Sports Exerc. PD JUN PY 2001 VL 33 IS 6 SU S BP S611 EP S621 DI 10.1097/00005768-200106001-00030 PG 11 WC Sport Sciences SC Sport Sciences GA 441GT UT WOS:000169223200030 PM 11427786 ER PT J AU Wang, DQ Babu, SS Payzant, EA Radaelli, PG Hannon, AC AF Wang, DQ Babu, SS Payzant, EA Radaelli, PG Hannon, AC TI In-situ characterization of gamma/gamma ' lattice stability in a nickel-base superalloy by neutron diffraction SO METALLURGICAL AND MATERIALS TRANSACTIONS A-PHYSICAL METALLURGY AND MATERIALS SCIENCE LA English DT Article ID TITANIUM C1 Oak Ridge Natl Lab, Div Met & Ceram, Oak Ridge, TN 37831 USA. Rutherford Appleton Lab, ISIS Facil, Didcot OX11 0QX, Oxon, England. RP Wang, DQ (reprint author), NOMOS Corp, 2591 Wexford Bayne Rd, Sewickley, PA 15143 USA. RI Payzant, Edward/B-5449-2009; Radaelli, Paolo/C-2952-2011; Babu, Sudarsanam/D-1694-2010 OI Payzant, Edward/0000-0002-3447-2060; Radaelli, Paolo/0000-0002-6717-035X; Babu, Sudarsanam/0000-0002-3531-2579 NR 12 TC 5 Z9 6 U1 1 U2 2 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 JUN PY 2001 VL 32 IS 6 BP 1551 EP 1556 DI 10.1007/s11661-001-0242-3 PG 6 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA 440GF UT WOS:000169167000027 ER PT J AU Zhu, YT Jiang, HG Huang, JY Lowe, TC AF Zhu, YT Jiang, HG Huang, JY Lowe, TC TI A new route to bulk nanostructured metals SO METALLURGICAL AND MATERIALS TRANSACTIONS A-PHYSICAL METALLURGY AND MATERIALS SCIENCE LA English DT Article ID GRAIN-REFINEMENT; COPPER C1 Los Alamos Natl Lab, Div Mat Sci & Technol, Los Alamos, NM 87545 USA. Technanogy, Newport Beach, CA 92660 USA. RP Zhu, YT (reprint author), Los Alamos Natl Lab, Div Mat Sci & Technol, Los Alamos, NM 87545 USA. RI Zhu, Yuntian/B-3021-2008; Huang, Jianyu/C-5183-2008 OI Zhu, Yuntian/0000-0002-5961-7422; NR 11 TC 87 Z9 93 U1 0 U2 17 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 JUN PY 2001 VL 32 IS 6 BP 1559 EP 1562 DI 10.1007/s11661-001-0245-0 PG 4 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA 440GF UT WOS:000169167000029 ER PT J AU Lexa, D Johnson, I AF Lexa, D Johnson, I TI Occlusion and ion exchange in the molten (lithium chloride-potassium chloride-alkali metal chloride) salt plus zeolite 4A system with alkali metal chlorides of sodium, rubidium, and cesium SO METALLURGICAL AND MATERIALS TRANSACTIONS B-PROCESS METALLURGY AND MATERIALS PROCESSING SCIENCE LA English DT Article AB Interaction between molten salts of the type LiCl-KCl-MeCl (Me = Na, Rb, Cs, x(MeCl) = 0 to 0.5, x(KCl)/x(LiCl) = 0.69) and zeolite 4A have been studied at 823 K. The main interactions between these salts and zeolite are molten salt occlusion to form salt-loaded zeolite and ion exchange between the molten salt and salt-loaded zeolite. No chemical reaction has been observed. The extent of occlusion is a function of the concentration of MeCl in the zeolite and is equal to 11 +/- 1 Cl- per zeolite unit cell, (AlSiO4)(12), at infinite MeCl dilution. The ion-exchange mole fraction equilibrium constants (separation factors) with respect to Li are decreasing functions of concentration of MeCl in the zeolite. At infinite MeCl dilution, they are equal to 0.84, 0.87, and 2.31 for NaCl, RbCl, and CsCl, respectively, and increase in the order Na < Rb < Cs at identical MeCl concentrations. The standard ion-exchange chemical potentials are equal to -(0.0 +/- 0.5) kJ.mol(-1), -(0.4 +/- 0.3) kJ.mol(-1), and -(6.5 +/- 0.5) kJ.mol(-1) for Na+, Rb+, and Cs+, respectively. C1 Argonne Natl Lab, Div Chem Technol, Argonne, IL 60439 USA. RP Lexa, D (reprint author), Argonne Natl Lab, Div Chem Technol, 9700 S Cass Ave, Argonne, IL 60439 USA. NR 12 TC 16 Z9 16 U1 3 U2 8 PU MINERALS METALS MATERIALS SOC PI WARRENDALE PA 184 THORN HILL RD, WARRENDALE, PA 15086 USA SN 1073-5615 J9 METALL MATER TRANS B JI Metall. Mater. Trans. B-Proc. Metall. Mater. Proc. Sci. PD JUN PY 2001 VL 32 IS 3 BP 429 EP 435 DI 10.1007/s11663-001-0028-4 PG 7 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA 440NB UT WOS:000169180400007 ER PT J AU Wan, YP Fincke, JR Jiang, XY Sampath, S Prasad, V Herman, H AF Wan, YP Fincke, JR Jiang, XY Sampath, S Prasad, V Herman, H TI Modeling of oxidation of molybdenum particles during plasma spray deposition SO METALLURGICAL AND MATERIALS TRANSACTIONS B-PROCESS METALLURGY AND MATERIALS PROCESSING SCIENCE LA English DT Article ID EVAPORATION AB An oxidation model for molybdenum particles during the plasma spray deposition process is presented. Based on a well-verified model for plasma chemistry and the heating and phase change of particles in a plasma plume, this model accounts for the oxidant diffusion around the surface of particles or splats, oxidation on the surface, as well as oxygen diffusion in molten molybdenum. Calculations are performed for a single molybdenum particle sprayed under Metco-9MB spraying conditions. The oxidation features of particles during the flight are compared with those during the deposition. The result shows the dominance of oxidation of a molybdenum particle during the flight, as well as during deposition when the substrate temperature is high (above 400 degreesC). C1 GT Equipement Technol Inc, Nashua, NH 03063 USA. SUNY Stony Brook, Ctr Thermal Spray Res, Stony Brook, NY 11794 USA. SUNY Stony Brook, Proc Modeling Lab, Stony Brook, NY 11794 USA. Idaho Natl Engn & Environm Lab, Idaho Falls, ID USA. RP Wan, YP (reprint author), GT Equipement Technol Inc, Nashua, NH 03063 USA. NR 15 TC 11 Z9 13 U1 2 U2 7 PU MINERALS METALS MATERIALS SOC PI WARRENDALE PA 184 THORN HILL RD, WARRENDALE, PA 15086 USA SN 1073-5615 J9 METALL MATER TRANS B JI Metall. Mater. Trans. B-Proc. Metall. Mater. Proc. Sci. PD JUN PY 2001 VL 32 IS 3 BP 475 EP 481 DI 10.1007/s11663-001-0033-7 PG 7 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA 440NB UT WOS:000169180400012 ER PT J AU Fan, HY Reed, S Baer, T Schunk, R Lopez, GP Brinker, CJ AF Fan, HY Reed, S Baer, T Schunk, R Lopez, GP Brinker, CJ TI Hierarchically structured functional porous silica and composite produced by evaporation-induced self-assembly SO MICROPOROUS AND MESOPOROUS MATERIALS LA English DT Article; Proceedings Paper CT 2nd International Symposium on Mesoporous Molecular Sieves (ISMMS) CY AUG 27-SEP 02, 2000 CL QUEBEC CITY, CANADA DE surfactant self-assembly; mesoporous; micro-pen writing; ink-jet printing; selective de-wetting ID MESOPOROUS MOLECULAR-SIEVES; FINITE-ELEMENT METHOD; FREE-SURFACE FLOWS; INCOMPRESSIBLE FLUIDS; 3 DIMENSIONS; FILMS; MONOLAYERS; MICROFABRICATION; GOLD AB Recently so-called soft lithography approaches [Angew. Chem. Int. Ed. 37 (1998) 550] have been combined with surfactant [Adv. Mater. 9 (1997) 811, Nature 390 (1997) 674] and particulate [Science 282 (1998) 2244] templating procedures to create oxides with multiple levels of structural order. But the materials thus formed have been limited primarily to oxides with no specific functionality, and the associated processing times have ranged from hours to days. Using self-assembling inks we have combined evaporation-induced (silica/surfactant) self-assembly [Adv. Mater. 11 (1999) 579] with rapid prototyping techniques like micro-pen lithography [Science 283 (1999) 661, Mat. Res. Sec. Symp. Proc. 542 (1999) 159], ink-jet printing [Adv. Mater. 11 (1999) 734, Mat. Sci. Eng. C5 (1998) 289], and dip coating on micro-contact printed substrates to form hierarchically organized structures in seconds. By co-condensation of tetrafunctional silanes (Si(OR)(4)) with tri-functional organosilanes ((RO)(3)SiR ') [Chem. Commun. (1999) 1367, Chem. Commun. (1997) 1769, J. Am. Chem. Sec. 119 (1997) 4090] or bridged silsesquioxanes (RO)(3)Si-R '-(Si(OR)(3)) or by inclusion of organic additives, we have selectively derivatized the silica framework with functional R ' ligands or molecules. The rapid-prototyping procedures we describe are simple, employ readily available equipment. and provide a link between computer-aided design and self-assembled functional nanostructures. We expect that the ability to form arbitrary functional designs on arbitrary surfaces will be of practical importance for directly writing sensor arrays and Acidic or photonic systems. (C) 2001 Elsevier Science B.V. All rights reserved. C1 Univ New Mexico, Dept Chem & Nucl Engn, Ctr Microengineered Mat, Albuquerque, NM 87131 USA. Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Univ New Mexico, Dept Chem & Nucl Engn, Ctr Microengineered Mat, Albuquerque, NM 87131 USA. NR 33 TC 67 Z9 67 U1 5 U2 33 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 1387-1811 EI 1873-3093 J9 MICROPOR MESOPOR MAT JI Microporous Mesoporous Mat. PD JUN PY 2001 VL 44 SI SI BP 625 EP 637 DI 10.1016/S1387-1811(01)00243-8 PG 13 WC Chemistry, Applied; Chemistry, Physical; Nanoscience & Nanotechnology; Materials Science, Multidisciplinary SC Chemistry; Science & Technology - Other Topics; Materials Science GA 447EF UT WOS:000169557700075 ER PT J AU Hillhouse, HW van Egmond, JW Tsapatsis, M Hanson, JC Larese, JZ AF Hillhouse, HW van Egmond, JW Tsapatsis, M Hanson, JC Larese, JZ TI The interpretation of X-ray diffraction data for the determination of channel orientation in mesoporous films SO MICROPOROUS AND MESOPOROUS MATERIALS LA English DT Article; Proceedings Paper CT 2nd International Symposium on Mesoporous Molecular Sieves (ISMMS) CY AUG 27-SEP 02, 2000 CL QUEBEC CITY, CANADA DE MCM-41; mesoporous; oriented film; X-ray diffraction; Ewald's construction ID SILICA FILMS; THIN-FILMS; ALIGNMENT; DEFECTS AB The relationship between channel orientation in ordered hexagonal phase (plane group p6mm) mesoporous silica films and observed diffraction data is analyzed using Ewald's construction for both reflection geometry and transmission geometry X-ray diffraction. This analysis clarifies ambiguities in the interpretation of diffraction peak absences in patterns collected from a standard powder diffractometer. In particular, it is found that the absence of the 1 10 reflection in this geometry does not indicate that the channels of the hexagonal mesophase are oriented parallel to the substrate but indicates only that the mesophase is rotationally invariant about the sixfold axis with a fraction of the mesophase oriented such that the 100 face is parallel to the substrate. This does not exclude the possibility of coexisting orientations that are perpendicular or inclined to the substrate. A comparison between predicted diffraction patterns and experimental data is used to illustrate this possibility. As a result. the use of 2D transmission X-ray diffraction, grazing angle X-ray diffraction, or pole figure analysis is more appropriate to characterize the channel orientation in mesoporous films. (C) 2001 Elsevier Science B.V. Al rights reserved. C1 Univ Massachusetts, Dept Chem Engn, Goessmann Lab 159, Amherst, MA 01002 USA. Brookhaven Natl Lab, Dept Chem, Upton, NY 11973 USA. RP Tsapatsis, M (reprint author), Univ Massachusetts, Dept Chem Engn, Goessmann Lab 159, Amherst, MA 01002 USA. RI Hanson, jonathan/E-3517-2010 NR 13 TC 60 Z9 62 U1 1 U2 15 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 JUN PY 2001 VL 44 SI SI BP 639 EP 643 DI 10.1016/S1387-1811(01)00244-X PG 5 WC Chemistry, Applied; Chemistry, Physical; Nanoscience & Nanotechnology; Materials Science, Multidisciplinary SC Chemistry; Science & Technology - Other Topics; Materials Science GA 447EF UT WOS:000169557700076 ER PT J AU Lowell, GR Noll, PD AF Lowell, GR Noll, PD TI Fe-Cu-Au-bearing scapolite skarn in moat sediments of the Taum Sauk Caldera, southeastern Missouri, USA SO MINERALOGICAL MAGAZINE LA English DT Article DE reduced skarn; Fe-Cu-Au; mesoproterozoic; SE Missouri; St. Francois Mountains ID ST-FRANCOIS TERRANE; DEPOSITS; IRON; NOMENCLATURE; MINERALS; COUNTY AB Stromatolitic carbonate in moat-fill of a 1.48 Ga caldera was converted to mineralized calc-silicate skarn by interaction with magma-derived brine at Ketcherside Gap in southeastern Missouri. The skarn records early low f(O2) conditions similar to those of reduced W and Au skarns. Initial skarn-forming conditions were: P-L less than or equal to 221 bar (22.1 MPa), X-CO2 less than or equal to 0.10, T = 450-400 degreesC, log f(O2) approximate to -30, and log f(S2) less than or equal to -13. Late skarn records combined effects of T down arrow, f(O2)up arrow, f(S2)up arrow, X(CO2)up arrow, and appearance of an immiscible CO2-rich vapour. The absence of a contact aureole indicates that skarn reactions were driven by advective heat transfer from an infiltrating fluid. Elsewhere in the region, hypersaline, synvolcanic fluids produced oxidized endoskarn in rhyolite. Development of carbonate-hosted, reduced skarn in caldera moat sediments is attributed to: (1) the nature of the host rock and reaction along a lengthy flow path; (2) early, but temporary, dilution of brine influx by CO2-producing reactions; and (3) cooling, possibly accompanied by increased brine influx with time. C1 SE Missouri State Univ, Dept Geosci, Cape Girardeau, MO 63701 USA. Univ Calif Los Alamos Natl Lab, CAAC, Los Alamos, NM 87545 USA. RP Lowell, GR (reprint author), SE Missouri State Univ, Dept Geosci, Cape Girardeau, MO 63701 USA. NR 57 TC 6 Z9 6 U1 2 U2 6 PU MINERALOGICAL SOCIETY PI LONDON PA 41 QUEENS GATE, LONDON SW7 5HR, ENGLAND SN 0026-461X J9 MINERAL MAG JI Mineral. Mag. PD JUN PY 2001 VL 65 IS 3 BP 373 EP 396 DI 10.1180/002646101300119466 PG 24 WC Mineralogy SC Mineralogy GA 444VM UT WOS:000169420800004 ER PT J AU Burke, P Schooler, K Wiley, HS AF Burke, P Schooler, K Wiley, HS TI Regulation of epidermal growth factor receptor signaling by endocytosis and intracellular trafficking SO MOLECULAR BIOLOGY OF THE CELL LA English DT Article ID MAMMARY EPITHELIAL-CELLS; ACTIVATED PROTEIN-KINASE; FACTOR-ALPHA BIND; EGF RECEPTOR; TYROSINE KINASE; C-CBL; DOWN-REGULATION; BETA(2)-ADRENERGIC RECEPTOR; SH2-CONTAINING PROTEINS; ERBB RECEPTORS AB Ligand activation of the epidermal growth factor receptor (EGFR) leads to its rapid internalization and eventual delivery to lysosomes. This process is thought to be a mechanism to attenuate signaling, but signals could potentially be generated after endocytosis. To directly evaluate EGFR signaling during receptor trafficking, we developed a technique to rapidly and selectively isolate internalized EGFR and associated molecules with the use of reversibly biotinylated anti-EGFR antibodies. In addition, we developed antibodies specific to tyrosine-phosphorylated EGFR. With the use of a combination of fluorescence imaging and affinity precipitation approaches, we evaluated the state of EGFR activation and substrate association during trafficking in epithelial cells. We found that after internalization, EGFR remained active in the early endosomes. However, receptors were inactivated before degradation, apparently due to ligand removal from endosomes. Adapter molecules, such as Shc, were associated with EGFR both at the cell surface and within endosomes. Some molecules, such as Grb2, were primarily found associated with surface EGFR, whereas others, such as Eps8, were found only with intracellular receptors. During the inactivation phase, c-Cbl became EGFR associated, consistent with its postulated role in receptor attenuation. We conclude that the association of the EGFR with different proteins is compartment specific. In addition, ligand loss is the proximal cause of EGFR inactivation. Thus, regulated trafficking could potentially influence the pattern as well as the duration of signal transduction. C1 Univ Utah, Dept Pathol, Div Cell Biol & Immunol, Salt Lake City, UT 84132 USA. RP Wiley, HS (reprint author), Pacific NW Natl Lab, Fundamental Sci Div, MSIN P7-56,POB 999, Richland, WA 99352 USA. OI Wiley, Steven/0000-0003-0232-6867 FU NICHD NIH HHS [P01-HD28528] NR 69 TC 240 Z9 246 U1 0 U2 22 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 JUN PY 2001 VL 12 IS 6 BP 1897 EP 1910 PG 14 WC Cell Biology SC Cell Biology GA 461DT UT WOS:000170350200028 PM 11408594 ER PT J AU Peng, Y Mian, IS Lue, NF AF Peng, Y Mian, IS Lue, NF TI Analysis of telomerase processivity: Mechanistic similarity to HIV-1 reverse transcriptase and role in telomere maintenance SO MOLECULAR CELL LA English DT Article ID CATALYTIC SUBUNIT GENE; YEAST TELOMERASE; IN-VITRO; SACCHAROMYCES-CEREVISIAE; DNA-SYNTHESIS; TUMOR-CELLS; EST GENES; COMPLEX; REPLICATION; MUTANTS AB The key protein subunit of the telomerase complex, known as TERT, possesses a reverse transcriptase (RT)-like domain that is conserved in enzymes encoded by retroviruses and retroelements. Structural and functional analysis of HIV-1 RT suggests that RT processivity is governed, in part, by the conserved motif C, motif E, and a C-terminal domain. Mutations in analogous regions of the yeast TERT were found to have anticipated effects on telomerase processivity in vitro, suggesting a great deal of mechanistic and structural similarity between TERT and retroviral RTs, and a similarity that goes beyond the homologous domain. A close correlation was uncovered between telomerase processivity and telomere length in vivo, suggesting that enzyme processivity is a limiting factor for telomere maintenance. C1 Cornell Univ, Dept Microbiol & Immunol, WR Hearst Microbiol Res Ctr, Weill Med Coll, New York, NY 10021 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Life Sci, Berkeley, CA 94720 USA. RP Lue, NF (reprint author), Cornell Univ, Dept Microbiol & Immunol, WR Hearst Microbiol Res Ctr, Weill Med Coll, New York, NY 10021 USA. NR 46 TC 83 Z9 85 U1 0 U2 2 PU CELL PRESS PI CAMBRIDGE PA 1100 MASSACHUSETTES AVE,, CAMBRIDGE, MA 02138 USA SN 1097-2765 J9 MOL CELL JI Mol. Cell PD JUN PY 2001 VL 7 IS 6 BP 1201 EP 1211 DI 10.1016/S1097-2765(01)00268-4 PG 11 WC Biochemistry & Molecular Biology; Cell Biology SC Biochemistry & Molecular Biology; Cell Biology GA 447AY UT WOS:000169547400008 PM 11430823 ER PT J AU Inwood, W Kane, S DiRuggiero, J Robb, F Clark, AJ AF Inwood, W Kane, S DiRuggiero, J Robb, F Clark, AJ TI The RadB protein from Pyrococcus does not complement E-coli recA mutations in vivo SO MOLECULAR GENETICS AND GENOMICS LA English DT Article DE radB gene; Pyrococcus furiosus; recA gene; recombination; repair of UV damage ID DNA STRAND EXCHANGE; HYPERTHERMOPHILIC ARCHAEON; RECA/RAD51 HOMOLOG; ESCHERICHIA-COLI; SACCHAROMYCES-CEREVISIAE; GLUTAMATE-DEHYDROGENASE; FURIOSUS; EXPRESSION; POLYMERASE; BINDING AB A previous publication claimed that the radB gene called Pk-REC from Pyrococcus furiosus complemented an E. coli recA mutation. We found that a sequencing error had led to the test of a mutant form of Pk-REC. The wild-type radB gene from P. furiosus cloned in a similar expression vector to the mutant Pk-REC also appeared to complement an E. coh recA mutation. However, the cloned P. furiosus gdh (glutamate dehydrogenase) gene showed the same activity. We therefore concluded that overexpression of any protein can produce an artificial growth inhibition or stationary phase in recA mutant cells, which allows cells to recover from UV damage due to the action of repair systems that do not require RecA-like activity. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Dept Mol & Cell Biol, Div Life Sci, Berkeley, CA 94720 USA. Univ Maryland, Inst Biotechnol, Ctr Marine Biotechnol, Baltimore, MD 21201 USA. Univ Arizona, Dept Mol & Cellular Biol, Tucson, AZ 85721 USA. RP Clark, AJ (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Dept Mol & Cell Biol, Div Life Sci, Berkeley, CA 94720 USA. OI Robb, Frank/0000-0001-5833-6496 FU NIAID NIH HHS [AI05371] NR 24 TC 1 Z9 1 U1 0 U2 1 PU SPRINGER-VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 USA SN 1617-4615 J9 MOL GENET GENOMICS JI Mol. Genet. Genomics PD JUN PY 2001 VL 265 IS 4 BP 683 EP 686 PG 4 WC Biochemistry & Molecular Biology; Genetics & Heredity SC Biochemistry & Molecular Biology; Genetics & Heredity GA 457AQ UT WOS:000170115300013 PM 11459188 ER PT J AU Murali, A Barve, A Leppert, VJ Risbud, SH Kennedy, IM Lee, HWH AF Murali, A Barve, A Leppert, VJ Risbud, SH Kennedy, IM Lee, HWH TI Synthesis and characterization of indium oxide nanoparticles SO NANO LETTERS LA English DT Article ID FILMS AB Nanoparticles of indium oxide, a transparent conducting oxide with a band gap close to GaN, were synthesized by pulsed laser ablation of a pure indium metal target. X-ray diffraction and transmission electron microscopy confirmed that nanocrystalline indium oxide particles with a mean diameter of 6.6 nm with a cubic crystal structure were formed. Photoluminescence spectroscopy shows a strong emission peak at 3.78 eV with a weak size dependence. C1 Univ Calif Davis, Dept Chem Engn & Mat Sci, Davis, CA 95616 USA. Univ Calif Davis, Dept Mech & Aeronaut Engn, Davis, CA 95616 USA. Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. RP Risbud, SH (reprint author), Univ Calif Davis, Dept Chem Engn & Mat Sci, Davis, CA 95616 USA. NR 11 TC 122 Z9 122 U1 2 U2 21 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 1530-6984 J9 NANO LETT JI Nano Lett. PD JUN PY 2001 VL 1 IS 6 BP 287 EP 289 DI 10.1021/nl010013q PG 3 WC Chemistry, Multidisciplinary; Chemistry, Physical; Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Physics, Applied; Physics, Condensed Matter SC Chemistry; Science & Technology - Other Topics; Materials Science; Physics GA 519JC UT WOS:000173721200002 ER PT J AU Bradbury, A AF Bradbury, A TI Selecting by microdialysis SO NATURE BIOTECHNOLOGY LA English DT News Item ID LIBRARIES; SURFACE; DISPLAY C1 Univ Calif Los Alamos Natl Lab, Biosci Div, Los Alamos, NM 87544 USA. SISSA, Int Sch Adv Studies, Trieste, Italy. RP Bradbury, A (reprint author), Univ Calif Los Alamos Natl Lab, Biosci Div, MS M888, Los Alamos, NM 87544 USA. NR 11 TC 1 Z9 1 U1 0 U2 1 PU NATURE AMERICA INC PI NEW YORK PA 345 PARK AVE SOUTH, NEW YORK, NY 10010-1707 USA SN 1087-0156 J9 NAT BIOTECHNOL JI Nat. Biotechnol. PD JUN PY 2001 VL 19 IS 6 BP 528 EP 529 DI 10.1038/89258 PG 2 WC Biotechnology & Applied Microbiology SC Biotechnology & Applied Microbiology GA 438YK UT WOS:000169081700022 PM 11385448 ER PT J AU Yarema, KJ Goon, S Bertozzi, CR AF Yarema, KJ Goon, S Bertozzi, CR TI Metabolic selection of glycosylation defects in human cells SO NATURE BIOTECHNOLOGY LA English DT Article ID POLYMERASE CHAIN-REACTION; ACID STORAGE DISEASE; ADHESION MOLECULE; POLYSIALIC ACID; PROTEIN GLYCOSYLATION; SIALIC ACIDS; EXPRESSION; CANCER; BIOSYNTHESIS; SURFACE AB Changes in glycosylation are often associated with disease progression, but the genetic and metabolic basis of these events is rarely understood in detail at a molecular level. We describe a metabolism-based approach to the selection of mutants in glycoconjugate biosynthesis that provides insight into regulatory mechanisms for oligosaccharide expression and metabolic flux. Unnatural intermediates are used to challenge a specific pathway, and cell surface expression of their metabolic products provides a readout of flux in that pathway and a basis for selecting genetic mutants. The approach was applied to the sialic acid metabolic pathway in human cells, yielding novel mutants with phenotypes related to the inborn metabolic defect sialuria and metastatic tumor cells. C1 Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Mol & Cell Biol, Berkeley, CA 94720 USA. Lawrence Berkeley Natl Lab, Ctr Adv Mat, Div Mat Sci, Berkeley, CA 94720 USA. Howard Hughes Med Inst, Berkeley, CA 94720 USA. RP Bertozzi, CR (reprint author), Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. FU NIGMS NIH HHS [GM58867-01] NR 34 TC 43 Z9 45 U1 0 U2 5 PU NATURE AMERICA INC PI NEW YORK PA 345 PARK AVE SOUTH, NEW YORK, NY 10010-1707 USA SN 1087-0156 J9 NAT BIOTECHNOL JI Nat. Biotechnol. PD JUN PY 2001 VL 19 IS 6 BP 553 EP 558 DI 10.1038/89305 PG 6 WC Biotechnology & Applied Microbiology SC Biotechnology & Applied Microbiology GA 438YK UT WOS:000169081700029 PM 11385460 ER PT J AU Bonni, S Wang, HR Causing, CG Kavsak, P Stroschein, SL Luo, KX Wrana, JL AF Bonni, S Wang, HR Causing, CG Kavsak, P Stroschein, SL Luo, KX Wrana, JL TI TGF-beta induces assembly of a Smad2-Smurf2 ubiquitin ligase complex that targets SnoN for degradation SO NATURE CELL BIOLOGY LA English DT Article ID TRANSFORMING-GROWTH-FACTOR; KAPPA-B-ALPHA; SMAD PROTEINS; DEPENDENT DEGRADATION; SKI ONCOPROTEIN; CO-REPRESSOR; RECEPTOR; TRCP; PHOSPHORYLATION; CATENIN AB The receptor-regulated Smad proteins are essential intracellular mediators of signal transduction by the transforming growth factor-beta (TGF-beta) superfamily of growth factors and are also important as regulators of gene transcription. Here we describe a new role for TGF-beta -regulated Smad2 and Smad3 as components of a ubiquitin ligase complex. We show that in the presence of TGF-beta signalling, Smad2 interacts through its proline-rich PPXY motif with the tryptophan-rich WW domains of Smurf2, a recently identified E3 ubiquitin ligases. TGF-beta also induces the association of Smurf2 with the transcriptional cc-repressor SnoN and we show that Smad2 can function to mediate this interaction. This allows Smurf2 HECT domain to target SnoN for ubiquitin-mediated degradation by the proteasome. Thus, stimulation by TGF-beta can induce the assembly of a Smad2-Smurf2 ubiquitin ligase complex that functions to target substrates for degradation. C1 Mt Sinai Hosp, Samuel Lunenfeld Res Inst, Program Mol Biol, Toronto, ON M5G 1X5, Canada. Univ Toronto, Dept Med Genet & Microbiol, Toronto, ON M5S 1A8, Canada. Univ Calif Berkeley, Div Life Sci, Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Mol & Cell Biol, Berkeley, CA 94720 USA. RP Wrana, JL (reprint author), Mt Sinai Hosp, Samuel Lunenfeld Res Inst, Program Mol Biol, 600 Univ Ave, Toronto, ON M5G 1X5, Canada. RI Wrana, Jeffrey/F-8857-2013; Tang, Amy/L-3226-2016 OI Tang, Amy/0000-0002-5772-2878 NR 39 TC 217 Z9 236 U1 2 U2 12 PU MACMILLAN PUBLISHERS LTD PI LONDON PA PORTERS SOUTH, 4 CRINAN ST, LONDON N1 9XW, ENGLAND SN 1465-7392 J9 NAT CELL BIOL JI Nat. Cell Biol. PD JUN PY 2001 VL 3 IS 6 BP 587 EP 595 DI 10.1038/35078562 PG 9 WC Cell Biology SC Cell Biology GA 440VC UT WOS:000169194400015 PM 11389444 ER PT J AU Walker, BD Korber, BT AF Walker, BD Korber, BT TI Immune control of HIV: the obstacles of HLA and viral diversity SO NATURE IMMUNOLOGY LA English DT Editorial Material ID T-LYMPHOCYTE RESPONSES; INFECTION; VIREMIA; CD8(+); IDENTIFICATION C1 Massachusetts Gen Hosp, Partners AIDS Res Ctr, Boston, MA 02114 USA. Harvard Univ, Sch Med, Div AIDS, Boston, MA 02114 USA. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Walker, BD (reprint author), Massachusetts Gen Hosp, Partners AIDS Res Ctr, Boston, MA 02114 USA. OI Korber, Bette/0000-0002-2026-5757 NR 27 TC 129 Z9 132 U1 1 U2 4 PU NATURE AMERICA INC PI NEW YORK PA 345 PARK AVE SOUTH, NEW YORK, NY 10010-1707 USA SN 1529-2908 J9 NAT IMMUNOL JI Nat. Immunol. PD JUN PY 2001 VL 2 IS 6 BP 473 EP 475 DI 10.1038/88656 PG 3 WC Immunology SC Immunology GA 438WV UT WOS:000169078000004 PM 11376327 ER PT J AU Barton, WA Lesniak, J Biggins, JB Jeffrey, PD Jiang, JQ Rajashankar, KR Thorson, JS Nikolov, DB AF Barton, WA Lesniak, J Biggins, JB Jeffrey, PD Jiang, JQ Rajashankar, KR Thorson, JS Nikolov, DB TI Structure, mechanism and engineering of a nucleotidylyltransferase as a first step toward glycorandomization SO NATURE STRUCTURAL BIOLOGY LA English DT Article ID CRYSTAL-STRUCTURE; ESCHERICHIA-COLI; GALACTOSE-1-PHOSPHATE URIDYLYLTRANSFERASE; DEOXYSUGAR BIOSYNTHESIS; PYROPHOSPHORYLASE; PATHWAYS; NUCLEOTIDYLTRANSFERASE; NUCLEOTIDE; BACTERIA; ENZYME AB Metabolite glycosylation is affected by three classes of enzymes: nucleotidylyltransferases, which activate sugars as nucleotide diphospho-derivatives, intermediate sugar-modifying enzymes and glycosyltransferases. which transfer the final derivatized activated sugars to aglycon substrates. One of the first crystal structures of an enzyme responsible for the first step in this cascade, alpha -D-glucopyranosyl phosphate thymidylyltransferase (E-p) from Salmonella, in complex with product (UDP-Glc) and substrate (dTTP) is reported at 2.0 Angstrom and 2.1 Angstrom resolution, respectively. These structures, in conjunction with the kinetic characterization of E-p, clarify the catalytic mechanism of this important enzyme class. Structure-based engineering of E-p produced modified enzymes capable of utilizing 'unnatural' sugar phosphates not accepted by wild type E-p. The demonstrated ability to alter nucleotidylyltransferase specificity by design is an integral component of in vitro glycosylation systems developed for the production of diverse glycorandomized libraries. C1 Cornell Univ, Cellular Biochem & Biophys Program, New York, NY 10021 USA. Cornell Univ, Lab Biosynthet Chem, New York, NY 10021 USA. Cornell Univ, Mem Sloan Kettering Canc Ctr, New York, NY 10021 USA. Cornell Univ, Joan & Sanford I Weill Sch Med Sci, Sloan Kettering Div, New York, NY 10021 USA. Brookhaven Natl Lab, Upton, NY 11973 USA. RP Nikolov, DB (reprint author), Cornell Univ, Cellular Biochem & Biophys Program, 1275 York Ave, New York, NY 10021 USA. RI Thorson, Jon/L-3696-2013 OI Thorson, Jon/0000-0002-7148-0721 NR 37 TC 94 Z9 100 U1 1 U2 4 PU NATURE AMERICA INC PI NEW YORK PA 345 PARK AVE SOUTH, NEW YORK, NY 10010-1707 USA SN 1072-8368 J9 NAT STRUCT BIOL JI Nat. Struct. Biol. PD JUN PY 2001 VL 8 IS 6 BP 545 EP 551 DI 10.1038/88618 PG 7 WC Biochemistry & Molecular Biology; Biophysics; Cell Biology SC Biochemistry & Molecular Biology; Biophysics; Cell Biology GA 436EV UT WOS:000168924300020 PM 11373625 ER PT J AU Van Den Abeele, KEA Sutin, A Carmeliet, J Johnson, PA AF Van Den Abeele, KEA Sutin, A Carmeliet, J Johnson, PA TI Micro-damage diagnostics using nonlinear elastic wave spectroscopy (NEWS) SO NDT & E INTERNATIONAL LA English DT Article DE nonlinear acoustics; nonlinearity; hysteresis; damage diagnostics ID DISCERN MATERIAL DAMAGE; BEREA SANDSTONE; SLOW DYNAMICS; PROPAGATION; SOLIDS AB Nonlinear elastic wave spectroscopy (NEWS) represents a class of powerful tools which explore the dynamic nonlinear stress-strain features in the compliant bond system of a micro-inhomogeneous material and Link them to micro-scale damage. Hysteresis and nonlinearity in the constitutive relation (at the micro-strain level) result in acoustic and ultrasonic wave distortion, which gives rise to changes in the resonance frequencies as a function of drive amplitude, generation of accompanying harmonics, nonlinear attenuation, and multiplication of waves of different frequencies. The sensitivity of nonlinear methods to the detection of damage features (cracks, flaws, etc.) is far greater than can be obtained with linear acoustical methods (measures of wavespeed and wave dissipation). We illustrate two recently developed NEWS methods, and compare the results for both techniques on roofing tiles used in building construction. (C) 2001 Elsevier Science Ltd. All rights reserved. C1 Katholieke Univ Leuven, Interdisciplinary Res Ctr, B-8500 Kortrijk, Belgium. Stevens Inst Technol, Hoboken, NJ 07030 USA. Catholic Univ Louvain, Dept Bldg Phys, B-3001 Heverlee, Belgium. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Van Den Abeele, KEA (reprint author), Katholieke Univ Leuven, Interdisciplinary Res Ctr, Campus Kortrijk, B-8500 Kortrijk, Belgium. NR 39 TC 137 Z9 139 U1 5 U2 28 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0963-8695 J9 NDT&E INT JI NDT E Int. PD JUN PY 2001 VL 34 IS 4 BP 239 EP 248 DI 10.1016/S0963-8695(00)00064-5 PG 10 WC Materials Science, Characterization & Testing SC Materials Science GA 439YE UT WOS:000169144500003 ER PT J AU Smyser, C Grabowski, TJ Frank, RJ Bolinger, L AF Smyser, C Grabowski, TJ Frank, RJ Bolinger, L TI A real-time implementation of the general linear model for fMRI SO NEUROIMAGE LA English DT Meeting Abstract C1 Univ Iowa, Dept Neurol, Iowa City, IA 52242 USA. Univ Iowa, Dept Radiol, Iowa City, IA 52242 USA. Univ Calif Lawrence Livermore Natl Lab, Livermore, CA USA. NR 1 TC 0 Z9 0 U1 0 U2 1 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 JUN PY 2001 VL 13 IS 6 SU S BP S251 EP S251 PN 2 PG 1 WC Neurosciences; Neuroimaging; Radiology, Nuclear Medicine & Medical Imaging SC Neurosciences & Neurology; Radiology, Nuclear Medicine & Medical Imaging GA 439HQ UT WOS:000169106300252 ER PT J AU Stephen, J Aine, C Christner, R Ranken, D Huang, MX Best, E AF Stephen, J Aine, C Christner, R Ranken, D Huang, MX Best, E TI Differences in onset latencies of dorsal stream structures due to peripheral versus central visual field stimuation SO NEUROIMAGE LA English DT Meeting Abstract C1 Univ New Mexico, Sch Med, Dept Radiol, Albuquerque, NM 87131 USA. New Mexico VA Hlth Care Syst, Albuquerque, NM USA. Univ Calif Los Alamos Natl Lab, Biophys Grp, Los Alamos, NM 87545 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU ACADEMIC PRESS INC PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 1053-8119 J9 NEUROIMAGE JI Neuroimage PD JUN PY 2001 VL 13 IS 6 SU S BP S1007 EP S1007 PN 2 PG 1 WC Neurosciences; Neuroimaging; Radiology, Nuclear Medicine & Medical Imaging SC Neurosciences & Neurology; Radiology, Nuclear Medicine & Medical Imaging GA 439HQ UT WOS:000169106301006 ER PT J AU Volkow, N Zhu, W Felder, C Mueller, K Welsh, T Wang, GJ de Leon, M AF Volkow, N Zhu, W Felder, C Mueller, K Welsh, T Wang, GJ de Leon, M TI Changes in brain functional homogeneity in subjects with Alzheimer's Disease SO NEUROIMAGE LA English DT Meeting Abstract C1 Brookhaven Natl Lab, Dept Med, Upton, NY 11973 USA. SUNY Stony Brook, Dept Psychiat, Stony Brook, NY 11794 USA. SUNY Stony Brook, Dept Appl Math & Stat, Stony Brook, NY 11794 USA. SUNY Stony Brook, Dept Comp Sci, Stony Brook, NY 11794 USA. NYU, Dept Psychiat, New York, NY 10016 USA. Nathan S Kline Inst Psychiat Res, Orangeburg, NY 10962 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU ACADEMIC PRESS INC PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 1053-8119 J9 NEUROIMAGE JI Neuroimage PD JUN PY 2001 VL 13 IS 6 SU S BP S276 EP S276 PN 2 PG 1 WC Neurosciences; Neuroimaging; Radiology, Nuclear Medicine & Medical Imaging SC Neurosciences & Neurology; Radiology, Nuclear Medicine & Medical Imaging GA 439HQ UT WOS:000169106300277 ER PT J AU Zhu, W Volkow, N Mueller, K Welsh, T Meade, J AF Zhu, W Volkow, N Mueller, K Welsh, T Meade, J TI BrainMiner - an interactive tool for brain functional connectivity study SO NEUROIMAGE LA English DT Meeting Abstract C1 SUNY Stony Brook, Dept Appl Math & Stat, Stony Brook, NY 11794 USA. Brookhaven Natl Lab, Dept Med, Upton, NY 11973 USA. SUNY Stony Brook, Dept Psychiat, Stony Brook, NY 11794 USA. SUNY Stony Brook, Dept Comp Sci, Stony Brook, NY 11794 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU ACADEMIC PRESS INC PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 1053-8119 J9 NEUROIMAGE JI Neuroimage PD JUN PY 2001 VL 13 IS 6 SU S BP S293 EP S293 PN 2 PG 1 WC Neurosciences; Neuroimaging; Radiology, Nuclear Medicine & Medical Imaging SC Neurosciences & Neurology; Radiology, Nuclear Medicine & Medical Imaging GA 439HQ UT WOS:000169106300294 ER PT J AU Pinto, PA Eastman, RG AF Pinto, PA Eastman, RG TI The type Ia supernova width-luminosity relation SO NEW ASTRONOMY LA English DT Article DE supernovae : general; distance scale; radiative transfer ID SPECTRAL-LINES; LIGHT CURVES; WHITE-DWARFS; EXPLOSIONS; UNIVERSE; OPACITY; LAMBDA; OMEGA AB Observations of type Ia supernov ae at high redshifts have become an important tool for studying the geometry of the universe. The relation between the duration of the peak phase of a type Ia supernova's lightcurve and its luminosity (broader is brighter) forms the cornerstone of this measurement, yet it is a purely empirical relation. In this paper we show that the relation is a natural consequence of the radiation transport in type Ia supernovae and suggest constraints on the nature of the explosions which arise from our interpretation of the observed relation. The principle parameter underlying the relation is the mass of radioactive Ni-56 produced in the explosion. The relation is shown to be relatively insensitive to most other parameters in Chandrasekhar-mass explosions. Cosmological results are thus unlikely to suffer from systematic effects stemming from evolution in the explosions' progenitors. (C) 2001 Published by Elsevier Science B. V. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. Univ Calif Santa Cruz, Dept Astron & Astrophys, Santa Cruz, CA 95064 USA. RP Pinto, PA (reprint author), Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. NR 33 TC 33 Z9 33 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 1384-1092 J9 NEW ASTRON JI New Astron. PD JUN PY 2001 VL 6 IS 5 BP 307 EP 319 DI 10.1016/S1384-1076(01)00057-4 PG 13 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 449XV UT WOS:000169713200004 ER PT J AU Smith, UR AF Smith, UR TI Revision of the Cretaceous fossil genus Palaeoaster (Papaveraceae) and clarification of pertinent species of Eriocaulon, Palaeoaster, and Sterculiocarpus SO NOVON LA English DT Article DE Cretaceous; Eriocaulon; fossil; North America; Palaeoaster; Papaveraceae; Sterculiocarpus AB The fossil organ genus Palaeoaster (Papaveraceae), From the Cretaceous Western Interior of North America, is revised to contain a single species,, the new combination P. porosa. The type status is clarified and lectotypes are selected for the basionym Eriocaulon? porosum (Eriocaulaceae) and synonyms P. inquirenda, P? similis, and Sterculiocarpus coloradensis (Sterculiaceae). This revision reflects an informal circumscription of Palaeoaster in use since the late 1930s, and is the first of several papers on this genus. C1 Yale Univ, Dept Ecol & Evolutionary Biol, New Haven, CT 06520 USA. RP Smith, UR (reprint author), Univ Calif Los Alamos Natl Lab, Mail Stop K710, Los Alamos, NM 87545 USA. NR 25 TC 4 Z9 4 U1 2 U2 3 PU MISSOURI BOTANICAL GARDEN PI ST LOUIS PA 2345 TOWER GROVE AVENUE, ST LOUIS, MO 63110 USA SN 1055-3177 J9 NOVON JI Novon PD SUM PY 2001 VL 11 IS 2 BP 258 EP 260 DI 10.2307/3393064 PG 3 WC Plant Sciences SC Plant Sciences GA 451YJ UT WOS:000169830100013 ER PT J AU Lake, JA AF Lake, JA TI Foundations for the fourth generation of nuclear power (Reprinted from Nuclear News, November 2000) SO NUCLEAR ENERGY-JOURNAL OF THE BRITISH NUCLEAR ENERGY SOCIETY LA English DT Reprint C1 Idaho Natl Engn & Environm Lab, Amer Nucl Soc, Idaho Falls, ID 83401 USA. RP Lake, JA (reprint author), Idaho Natl Engn & Environm Lab, Amer Nucl Soc, Idaho Falls, ID 83401 USA. NR 1 TC 0 Z9 0 U1 1 U2 1 PU BRITISH NUCLEAR ENERGY SOC PI WESTMINSTER, LONDON PA 1-7 GREAT GEORGE ST, WESTMINSTER, LONDON, ENGLAND SW1P 3AA SN 0140-4067 J9 NUCL ENERG-J BR NUCL JI Nucl. Energy-J. Br. Nucl. Energy Soc. PD JUN PY 2001 VL 40 IS 3 BP 153 EP 157 DI 10.1680/nuen.40.3.153.40061 PG 5 WC Nuclear Science & Technology SC Nuclear Science & Technology GA 448YJ UT WOS:000169657300010 ER PT J AU Spong, DA Hirshman, SP Berry, LA Lyon, JF Fowler, RH Strickler, DJ Cole, MJ Nelson, BN Williamson, DE Ware, AS Alban, D Sanchez, R Fu, GY Monticello, DA Miner, WH Valanju, PM AF Spong, DA Hirshman, SP Berry, LA Lyon, JF Fowler, RH Strickler, DJ Cole, MJ Nelson, BN Williamson, DE Ware, AS Alban, D Sanchez, R Fu, GY Monticello, DA Miner, WH Valanju, PM TI Physics issues of compact drift optimized stellarators SO NUCLEAR FUSION LA English DT Article ID BALLOONING STABILITY; CONFINEMENT; TRANSPORT; FIELD AB Physics issues are discussed for compact stellarator configurations which achieve good confinement by the fact that the magnetic field modulus \B\ in magnetic co-ordinates is dominated by poloidally symmetric components. Two distinct configuration types are considered: (1) those which achieve their drift optimization and rotational transform at low beta and low bootstrap current by appropriate plasma shaping; and (2) those which have a greater reliance on plasma beta and bootstrap currents for supplying the transform and obtaining quasi-poloidal symmetry. Stability analysis of the latter group of devices against ballooning. kink and vertical displacement modes has indicated that stable beta values on the order of 15% are possible. The first class of devices is being considered for a low beta near term experiment that could explore some of the confinement features of the high beta configurations. C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. Univ Montana, Missoula, MT 59812 USA. Univ Carlos III Madrid, Madrid, Spain. Princeton Univ, Princeton Plasma Phys Lab, Princeton, NJ 08543 USA. Univ Texas, Austin, TX 78712 USA. RP Spong, DA (reprint author), Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RI Sanchez, Raul/C-2328-2008; Spong, Donald/C-6887-2012 OI Spong, Donald/0000-0003-2370-1873 NR 11 TC 54 Z9 54 U1 0 U2 1 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 JUN PY 2001 VL 41 IS 6 BP 711 EP 716 DI 10.1088/0029-5515/41/6/305 PG 6 WC Physics, Fluids & Plasmas SC Physics GA 449KD UT WOS:000169683000005 ER PT J AU Sugiyama, LE Park, W Strauss, HR Hudson, SR Stutman, D Tang, XZ AF Sugiyama, LE Park, W Strauss, HR Hudson, SR Stutman, D Tang, XZ TI Studies of spherical tori, stellarators and anisotropic pressure with the M3D code SO NUCLEAR FUSION LA English DT Article ID MAGNETOHYDRODYNAMICS; EQUILIBRIA; TOKAMAKS; MODELS AB The Multi-level 3D (M3D) project simulates plasmas using multiple levels of physics, geometry and grid models in one code package. The M3D code has been extended to fundamentally non-axisymmetric and small aspect ratio, R/a greater than or similar to 1, configurations. Applications include the non-linear stability of the NSTX spherical torus and of the spherical pinch, as well as the relaxation of stellarator equilibria. The fluid level physics model has been extended to evolve the anisotropic pressures p(j\:) and p(j perpendicular to) for the ion and electron species and has been applied to magnetic island evolution. C1 MIT, Cambridge, MA 02139 USA. Princeton Univ, Princeton Plasma Phys Lab, Princeton, NJ 08543 USA. NYU, New York, NY USA. Johns Hopkins Univ, Baltimore, MD USA. RP Sugiyama, LE (reprint author), MIT, 77 Massachusetts Ave, Cambridge, MA 02139 USA. RI Hudson, Stuart/H-7186-2013; Stutman, Dan/P-4048-2015 OI Hudson, Stuart/0000-0003-1530-2733; NR 15 TC 12 Z9 12 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 JUN PY 2001 VL 41 IS 6 BP 739 EP 746 DI 10.1088/0029-5515/41/6/309 PG 8 WC Physics, Fluids & Plasmas SC Physics GA 449KD UT WOS:000169683000009 ER PT J AU Chen, L Lin, Z White, RB Zonca, F AF Chen, L Lin, Z White, RB Zonca, F TI Non-linear zonal dynamics of drift and drift-Alfven turbulence in tokamak plasmas SO NUCLEAR FUSION LA English DT Article ID ION-TEMPERATURE-GRADIENT; DRIVEN; WAVES; TRANSPORT; FLOWS AB The present work addresses the issue of identifying the major non-linear physics processes which may regulate drift and drift-Alfven turbulence using a weak turbulence approach. Within this framework, on the basis of the non-linear gyrokinetic equation for both electrons and ions, an analytic theory is presented for non-linear zonal dynamics described in terms of two axisymmetric potentials, delta phi (z) and deltaA(parallel toz), which spatially depend only on a (magnetic) flux co-ordinate. Spontaneous excitation of zonal flows by electrostatic drift microinstabilities is demonstrated both analytically and by direct 3-D gyrokinetic stimulations. Direct comparisons indicate good agreement between analytic expressions of the zonal flow growth rate and numerical simulation results for ion temperature gradient driven modes. Analogously, it is shown that zonal flows may be spontaneously excited by drift-Alfven turbulence, in the form of modulational instability of the radial envelope of the mode as well, whereas in general, excitations of zonal currents are possible but have little feedback on the turbulence itself. C1 Univ Calif Irvine, Dept Phys & Astron, Irvine, CA 92668 USA. Princeton Univ, Princeton Plasma Phys Lab, Princeton, NJ 08543 USA. ENEA, Ctr Ric Frascati, Rome, Italy. RP Zonca, F (reprint author), Univ Calif Irvine, Dept Phys & Astron, Irvine, CA 92668 USA. RI chen, liu/I-2297-2013; White, Roscoe/D-1773-2013; Zonca, Fulvio/I-8236-2016 OI White, Roscoe/0000-0002-4239-2685; Zonca, Fulvio/0000-0002-9270-4704 NR 14 TC 54 Z9 55 U1 0 U2 6 PU INT ATOMIC ENERGY AGENCY PI VIENNA PA WAGRAMERSTRASSE 5, PO BOX 100, A-1400 VIENNA, AUSTRIA SN 0029-5515 J9 NUCL FUSION JI Nucl. Fusion PD JUN PY 2001 VL 41 IS 6 BP 747 EP 753 DI 10.1088/0029-5515/41/6/310 PG 7 WC Physics, Fluids & Plasmas SC Physics GA 449KD UT WOS:000169683000010 ER PT J AU Lindstrom, G Ahmed, M Albergo, S Allport, P Anderson, D Andricek, L Angarano, MM Augelli, V Bacchetta, N Bartalini, P Bates, R Biggeri, U Bilei, GM Bisello, D Boemi, D Borchi, E Botila, T Brodbeck, TJ Bruzzi, M Budzynski, T Burger, P Campabadal, F Casse, G Catacchini, E Chilingarov, A Ciampolini, P Cindro, V Costa, MJ Creanza, D Clauws, P Da Via, C Davies, G De Boer, W Dell'Orso, R De Palma, M Dezillie, B Eremin, V Evrard, O Fallica, G Fanourakis, G Feick, H Focardi, E Fonseca, L Fretwurst, E Fuster, J Gabathuler, K Glaser, M Grabiec, P Grigoriev, E Hall, G Hanlon, M Hauler, F Heising, S Holmes-Siedle, A Horisberger, R Hughes, G Huhtinen, M Ilyashenko, I Ivanov, A Jones, BK Jungermann, L Kaminsky, A Kohout, Z Kramberger, G Kuhnke, M Kwan, S Lemeilleur, F Leroy, C Letheren, M Li, Z Ligonzo, T Linhart, V Litovchenko, P Loukas, D Lozano, M Luczynski, Z Lutz, G MacEvoy, B Manolopoulos, S Markou, A Martinez, C Messineo, A Mikuz, M Moll, M Nossarzewska, E Ottaviani, G Oshea, V Parrini, G Passeri, D Petre, D Pickford, A Pintilie, I Pintilie, L Pospisil, S Potenza, R Radicci, V Raine, C Rafi, JM Ratoff, PN Richter, RH Riedler, P Roe, S Roy, P Ruzin, A Ryazanov, AI Santocchia, A Schiavulli, L Sicho, P Siotis, I Sloan, T Slysz, W Smith, K Solanky, M Sopko, B Stolze, K Avset, BS Svensson, B Tivarus, C Tonelli, G Tricomi, A Tzamarias, S Valvo, G Vasilescu, A Vayaki, A Verbitskaya, E Verdini, P Vrba, V Watts, S Weber, ER Wegrzecki, M Wegrzecka, I Weilhammer, P Wheadon, R Wilburn, C Wilhelm, I Wunstorf, R Wustenfeld, J Wyss, J Zankel, K Zabierowski, P Zontar, D AF Lindstrom, G Ahmed, M Albergo, S Allport, P Anderson, D Andricek, L Angarano, MM Augelli, V Bacchetta, N Bartalini, P Bates, R Biggeri, U Bilei, GM Bisello, D Boemi, D Borchi, E Botila, T Brodbeck, TJ Bruzzi, M Budzynski, T Burger, P Campabadal, F Casse, G Catacchini, E Chilingarov, A Ciampolini, P Cindro, V Costa, MJ Creanza, D Clauws, P Da Via, C Davies, G De Boer, W Dell'Orso, R De Palma, M Dezillie, B Eremin, V Evrard, O Fallica, G Fanourakis, G Feick, H Focardi, E Fonseca, L Fretwurst, E Fuster, J Gabathuler, K Glaser, M Grabiec, P Grigoriev, E Hall, G Hanlon, M Hauler, F Heising, S Holmes-Siedle, A Horisberger, R Hughes, G Huhtinen, M Ilyashenko, I Ivanov, A Jones, BK Jungermann, L Kaminsky, A Kohout, Z Kramberger, G Kuhnke, M Kwan, S Lemeilleur, F Leroy, C Letheren, M Li, Z Ligonzo, T Linhart, V Litovchenko, P Loukas, D Lozano, M Luczynski, Z Lutz, G MacEvoy, B Manolopoulos, S Markou, A Martinez, C Messineo, A Mikuz, M Moll, M Nossarzewska, E Ottaviani, G Oshea, V Parrini, G Passeri, D Petre, D Pickford, A Pintilie, I Pintilie, L Pospisil, S Potenza, R Radicci, V Raine, C Rafi, JM Ratoff, PN Richter, RH Riedler, P Roe, S Roy, P Ruzin, A Ryazanov, AI Santocchia, A Schiavulli, L Sicho, P Siotis, I Sloan, T Slysz, W Smith, K Solanky, M Sopko, B Stolze, K Avset, BS Svensson, B Tivarus, C Tonelli, G Tricomi, A Tzamarias, S Valvo, G Vasilescu, A Vayaki, A Verbitskaya, E Verdini, P Vrba, V Watts, S Weber, ER Wegrzecki, M Wegrzecka, I Weilhammer, P Wheadon, R Wilburn, C Wilhelm, I Wunstorf, R Wustenfeld, J Wyss, J Zankel, K Zabierowski, P Zontar, D CA Collaboration TI Developments for radiation hard silicon detectors by defect engineering - results by the CERN RD48 (ROSE) Collaboration SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT International Workshop on Semiconductor Pixel Detectors for Particles and X-rays CY JUN 05-08, 2000 CL GENOA, ITALY SP INFN, Univ Genova, ITC IRST Trento, CAEN Viareggio DE silicon detectors; gamma-, neutron-, proton and pion irradiation; improved radiation tolerance by oxygen enrichment; annealing studies; consequences for high energy physics applications AB This report summarises the final results obtained by the RD48 collaboration. The emphasis is on the more practical aspects directly relevant for LHC applications. The report is based on the comprehensive survey given in the 1999 status report (RD48 3rd Status Report, CERN/LHCC 2000-009, December 1999), a recent conference report (Lindstrom et al, (RD48), and some latest experimental results. Additional data have been reported in the last ROSE workshop (5th ROSE workshop, CERN, CERN/LEB 2000-005), A compilation of all RD48 internal reports and a full publication list can be found on the RD48 homepage (http://cern.ch/RD48/). The success of the oxygen enrichment of FZ-silicon as a highly powerful defect engineering technique and its optimisation with various commercial manufacturers are reported. The focus is on the changes of the effective doping concentration (depletion voltage). The RD48 model for the dependence of radiation effects on fluence, temperature and operational time is verified: projections to operational scenarios for main LHC experiments demonstrate vital benefits. Progress in the microscopic understanding of damage effects as well as the application of defect kinetics models and device modelling for the prediction of the macroscopic behaviour was also been achieved but will not be covered in detail. (C) 2001 Elsevier Science B.V. All rights reserved. C1 Univ Hamburg, Inst Expt Phys 2, D-22761 Hamburg, Germany. Brunel Univ, London, England. Univ Catania, Catania, Italy. Univ Liverpool, Liverpool L69 3BX, Merseyside, England. Fermilab Astrophys Ctr, Batavia, IL USA. Max Planck Inst, Munich, Germany. Univ Perugia, I-06100 Perugia, Italy. Dipartimento Interateneo Fis, Bari, Italy. Ist Nazl Fis Nucl, I-70126 Bari, Italy. Univ Padua, I-35100 Padua, Italy. Univ Glasgow, Glasgow G12 8QQ, Lanark, Scotland. Univ Florence, Florence, Italy. Inst Phys & Technol Mat, Bucharest, Romania. Univ Lancaster, Lancaster LA1 4YW, England. Inst Electr Mat Technol, Warsaw, Poland. Univ Autonoma Barcelona, Ctr Nacl Microelect, E-08193 Barcelona, Spain. Inst Fis Corpuscular, Valencia, Spain. Univ Ljubljana, Jozef Stefan Inst, Ljubljana 61000, Slovenia. Univ Ljubljana, Dept Phys, Ljubljana 61000, Slovenia. Univ Ghent, B-9000 Ghent, Belgium. Kings Coll London, London WC2R 2LS, England. Univ Karlsruhe, Karlsruhe, Germany. Ist Nazl Fis Nucl, Pisa, Italy. Brookhaven Natl Lab, Upton, NY 11973 USA. AF Ioffe Phys Tech Inst, St Petersburg, Russia. STMicroelectronics, Catania, Italy. Inst Phys Nucl, Demokritos, Greece. Univ Calif Berkeley, Dept Mat Sci & Engn, Berkeley, CA 94720 USA. PSI, Villigen, Switzerland. CERN, Geneva, Switzerland. Univ London Imperial Coll Sci Technol & Med, London, England. Czech Tech Univ, CR-16635 Prague, Czech Republic. Univ Montreal, Montreal, PQ, Canada. Ukrainian Acad Sci, Inst Nucl Res, UA-252028 Kiev, Ukraine. Inst Elect Mat Technol, Warsaw, Poland. Univ Modena, I-41100 Modena, Italy. Tel Aviv Univ, Dept Engn, IL-69978 Tel Aviv, Israel. IV Kurchatov Atom Energy Inst, Moscow 123182, Russia. IV Kurchatov Atom Energy Inst, Prague, Czech Republic. Acad Sci Czech Republic, Inst Phys, Prague, Czech Republic. CiS Inst Mikrosensor gGMBH, Erfurt, Germany. SINTEF, Oslo, Norway. Royal Inst Technol, Stockholm, Sweden. Inst Nucl Phys & Engn, Bucharest, Romania. Charles Univ Prague, Fac Math & Phys, Inst Nucl & Particle Phys, Prague, Czech Republic. Univ Dortmund, Dortmund, Germany. RP Univ Hamburg, Inst Expt Phys 2, Gbd 67b,Luruper Chaussee 149, D-22761 Hamburg, Germany. EM gunnar@sesam.desy.de RI Ruzin, Arie/P-9445-2016; Bruzzi, Mara/K-1326-2015; Pintilie, Ioana/C-4545-2011; Vasilescu, Angela/E-9915-2011; Rafi, Joan Marc/D-5500-2012; Focardi, Ettore/E-7376-2012; Grigoriev, Eugene/K-6650-2013; O'Shea, Val/G-1279-2010; Verbitskaya, Elena/D-1521-2014; Campabadal, Francesca/E-6651-2014; Ivanov, Alexander/E-3993-2014; Fonseca, Luis/K-8010-2012; Pintilie, Lucian/D-9475-2011 OI Passeri, Daniele/0000-0001-5322-2414; Tricomi, Alessia Rita/0000-0002-5071-5501; Wyss, Jeffery/0000-0002-8277-4012; SCHIAVULLI, Luigi/0000-0003-0871-3585; Bruzzi, Mara/0000-0001-7344-8365; Rafi, Joan Marc/0000-0003-4581-9477; Focardi, Ettore/0000-0002-3763-5267; Grigoriev, Eugene/0000-0001-7235-9715; O'Shea, Val/0000-0001-7183-1205; Campabadal, Francesca/0000-0001-7758-4567; Fonseca, Luis/0000-0002-1394-8074; Pintilie, Lucian/0000-0002-4934-2912 NR 26 TC 78 Z9 78 U1 1 U2 13 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 EI 1872-9576 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD JUN 1 PY 2001 VL 465 IS 1 BP 60 EP 69 DI 10.1016/S0168-9002(01)00347-3 PG 10 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 444XD UT WOS:000169424600008 ER PT J AU Parker, S Kenney, C AF Parker, S Kenney, C TI Charge compensation in irradiated semiconductor devices using high-resistivity field plates SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT International Workshop on Semiconductor Pixel Detectors for Particles and X-rays CY JUN 05-08, 2000 CL GENOA, ITALY SP INFN, Univ Genova, ITC IRST Trento, CAEN Viareggio DE field plates; semiconductor radiation detectors; sensors; oxide trapped charge; charge compensation; radiation damage; polysilicon resistors ID POLYCRYSTALLINE-SILICON FILMS; DETECTORS; CONDUCTION; RESISTORS; DENSITY; OXIDES; MODEL AB A field-plate structure using a high-resistivity material is described. As with other field plates, it can be used to compensate trapped charges in semiconductor devices, including radiation detectors, but because little current flows through it during the time a pulse is present on the signal electrodes, it does not significantly increase the effective capacitance between signal electrodes or other structures near the plates. (C) 2001 Elsevier Science B.V. All rights reserved. C1 Univ Hawaii, Honolulu, HI 96822 USA. RP Parker, S (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, MS 50B-6208, Berkeley, CA 94720 USA. NR 25 TC 1 Z9 1 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD JUN 1 PY 2001 VL 465 IS 1 BP 101 EP 107 DI 10.1016/S0168-9002(01)00363-1 PG 7 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 444XD UT WOS:000169424600014 ER PT J AU Chiodini, G Appel, JA Artuso, M Butler, JN Cancelo, G Cardoso, G Cheung, H Christian, DC Colautti, A Coluccia, R Di Corato, M Gottschalk, EE Hall, BK Hoff, J Kasper, PA Kutschke, R Kwan, SW Mekkaoui, A Menasce, D Newsom, C Sala, S Yarema, R Wang, JC Zimmermann, S AF Chiodini, G Appel, JA Artuso, M Butler, JN Cancelo, G Cardoso, G Cheung, H Christian, DC Colautti, A Coluccia, R Di Corato, M Gottschalk, EE Hall, BK Hoff, J Kasper, PA Kutschke, R Kwan, SW Mekkaoui, A Menasce, D Newsom, C Sala, S Yarema, R Wang, JC Zimmermann, S TI Beam test results of the BTeV silicon pixel detector SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT International Workshop on Semiconductor Pixel Detectors for Particles and X-rays CY JUN 05-08, 2000 CL GENOA, ITALY SP INFN, Univ Genova, ITC IRST Trento, CAEN Viareggio ID READOUT CHIP; DESIGN AB The results of the BTeV silicon pixel detector beam test carried out at Fermilab in 1999-2000 are reported. The pixel detector spatial resolution has been studied as a function of track inclination, sensor bias, and readout threshold. (C) 2001 Elsevier Science B.V. All rights reserved. C1 Fermi Natl Accelerator Lab, Batavia, IL 60510 USA. Univ Iowa, Iowa City, IA 52242 USA. Ist Nazl Fis Nucl, Sez Milano, I-20133 Milan, Italy. Univ Milan, Dipartimento Fis, I-20133 Milan, Italy. Syracuse Univ, Syracuse, NY USA. RP Chiodini, G (reprint author), Fermi Natl Accelerator Lab, POB 500, Batavia, IL 60510 USA. RI Menasce, Dario Livio/A-2168-2016 OI Menasce, Dario Livio/0000-0002-9918-1686 NR 10 TC 7 Z9 7 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD JUN 1 PY 2001 VL 465 IS 1 BP 125 EP 130 DI 10.1016/S0168-9002(01)00369-2 PG 6 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 444XD UT WOS:000169424600019 ER PT J AU Manfredi, PF Manghisoni, M AF Manfredi, PF Manghisoni, M TI Front-end electronics for pixel sensors SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT International Workshop on Semiconductor Pixel Detectors for Particles and X-rays CY JUN 05-08, 2000 CL GENOA, ITALY SP INFN, Univ Genova, ITC IRST Trento, CAEN Viareggio AB This paper discusses the criteria that underlie the design of front-end systems for pixel sensors of different types in a highly diversified fields of application. In the pixel front-end systems, low level analog signals coexist with digital activities and the design must comply with severe limitations in the area and in the power allotted to the single pixel cell. Noise and radiation hardness issues are of utmost importance in several applications. Some ways to arrive at a design which suits specific application requirements are discussed and the impact of the most advanced monolithic processes is evaluated. (C) 2001 Elsevier Science B.V. All rights reserved. C1 Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. Univ Pavia, I-27100 Pavia, Italy. Ist Nazl Fis Nucl, I-27100 Pavia, Italy. RP Manfredi, PF (reprint author), Univ Calif Berkeley, Lawrence Berkeley Natl Lab, 1 Cyclotron Rd, Berkeley, CA 94720 USA. OI Manghisoni, Massimo/0000-0001-5559-0894 NR 9 TC 20 Z9 20 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 JUN 1 PY 2001 VL 465 IS 1 BP 140 EP 147 DI 10.1016/S0168-9002(01)00374-6 PG 8 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 444XD UT WOS:000169424600022 ER PT J AU Mekkaoui, A Hoff, J AF Mekkaoui, A Hoff, J TI 30Mrad(SiO2) radiation tolerant pixel front end for the BTEV experiment SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT International Workshop on Semiconductor Pixel Detectors for Particles and X-rays CY JUN 05-08, 2000 CL GENOA, ITALY SP INFN, Univ Genova, ITC IRST Trento, CAEN Viareggio DE pixel; radiation tolerance; deep submicron AB The FPIX project is an effort underway at Fermilab to develop a pixel detector ASIC appropriate for use in the BTEV experiment. The most ambitious aspect of this project is that all data from all hit pixels must be read out every beam crossing (132 ns) for use in the lowest level trigger system. Included in each 50 mum x 400 mum pixel is a three-bit analog to digital converter which provides pulse height information to improve resolution. Given the proximity to the beam, the chips must be radiation tolerant. Rather than focusing efforts on a rad-hard technology, the choice has been made to use the inherent radiation tolerance of deep submicron processes with radiation tolerant design techniques. This paper discusses both the design and the radiation tolerance of the FPIX pixel cell. (C) 2001 Elsevier Science B.V. All rights reserved. C1 Fermi Natl Accelerator Lab, Batavia, IL 60510 USA. RP Mekkaoui, A (reprint author), Fermi Natl Accelerator Lab, POB 500, Batavia, IL 60510 USA. NR 11 TC 22 Z9 22 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 JUN 1 PY 2001 VL 465 IS 1 BP 166 EP 175 DI 10.1016/S0168-9002(01)00385-0 PG 10 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 444XD UT WOS:000169424600026 ER PT J AU Gemme, C Fiorello, AM Gagliardi, G Gilchriese, M Netchaeva, P Rossi, L Ruscino, E Vernocchi, F Varasi, M AF Gemme, C Fiorello, AM Gagliardi, G Gilchriese, M Netchaeva, P Rossi, L Ruscino, E Vernocchi, F Varasi, M TI Study of indium bumps for the ATLAS pixel detector SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT International Workshop on Semiconductor Pixel Detectors for Particles and X-rays CY JUN 05-08, 2000 CL GENOA, ITALY SP INFN, Univ Genova, ITC IRST Trento, CAEN Viareggio DE bump bonding; pixel detector AB The bump-bonding technology is used to join the front-end read-out chips to the silicon substrate of the ATLAS pixel detector. We review the current status of the technology used by Alenia Marconi Systems and we report on the electrical and mechanical properties and the defect rate of the Indium bumps. (C) 2001 Elsevier Science B.V. All rights reserved. C1 Univ Genoa, Dipartimento Fis, I-16146 Genoa, Italy. Ist Nazl Fis Nucl, I-16146 Genoa, Italy. Alenia Marconi Syst, Rome, Italy. Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. RP Gemme, C (reprint author), Univ Genoa, Dipartimento Fis, Via Dodecaneso 33, I-16146 Genoa, Italy. NR 1 TC 20 Z9 20 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 JUN 1 PY 2001 VL 465 IS 1 BP 200 EP 203 DI 10.1016/S0168-9002(01)00390-4 PG 4 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 444XD UT WOS:000169424600030 ER PT J AU Netchaeva, P Beccherle, R Darbo, G Einsweiler, K Gagliardi, G Gemme, C Gilchriese, M Oppizzi, P Richardson, J Rossi, L Ruscino, E Vernocchi, F Znizka, G AF Netchaeva, P Beccherle, R Darbo, G Einsweiler, K Gagliardi, G Gemme, C Gilchriese, M Oppizzi, P Richardson, J Rossi, L Ruscino, E Vernocchi, F Znizka, G TI Results on 0.7% X0 thick pixel modules for the ATLAS detector SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT International Workshop on Semiconductor Pixel Detectors for Particles and X-rays CY JUN 05-08, 2000 CL GENOA, ITALY SP INFN, Univ Genova, ITC IRST Trento, CAEN Viareggio AB Modules are the basic building blocks of the ATLAS pixel detector system, they are made of a silicon sensor the containing similar to 46 000 pixel cells of 50 mum x 400 mum, 16 front-end chips connected to the sensor through bump bonding, a kapton hex circuit and the module controller chip. The Pixel detector is the first to encounter particles emerging from LHC interactions, minimization of radiation length of pixel modules is therefore very important. We report here on the construction techniques and on the operation of the first ATLAS pixel modules of 0.7% radiation length thickness. We have operated these modules with threshold of 3700 x 10 +/- 300 x 10, mean noise value of 225 x 10 and 0.3% dead channels. (C) 2001 Published by Elsevier Science B.V. C1 Univ Genoa, I-16126 Genoa, Italy. Ist Nazl Fis Nucl, I-16146 Genoa, Italy. Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. RP Netchaeva, P (reprint author), Univ Genoa, I-16126 Genoa, Italy. NR 3 TC 7 Z9 7 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD JUN 1 PY 2001 VL 465 IS 1 BP 204 EP 210 DI 10.1016/S0168-9002(01)00391-6 PG 7 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 444XD UT WOS:000169424600031 ER PT J AU Zimmermann, S Kwan, SW Appel, JA Cancelo, GE Cardoso, G Cihangir, S Christian, DC Downing, RW Hoff, J Kasper, PA Mekkaoui, A Vargas, A Yarema, R AF Zimmermann, S Kwan, SW Appel, JA Cancelo, GE Cardoso, G Cihangir, S Christian, DC Downing, RW Hoff, J Kasper, PA Mekkaoui, A Vargas, A Yarema, R TI Development of high data readout rate pixel module and detector hybridization at Fermilab SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT International Workshop on Semiconductor Pixel Detectors for Particles and X-rays CY JUN 05-08, 2000 CL GENOA, ITALY SP INFN, Univ Genova, ITC IRST Trento, CAEN Viareggio AB At Fermilab, both pixel detector multichip module and sensor hybridization are being developed for the BTeV experiment. The base line design of the module and preliminary results of characterization tests are presented. (C) 2001 Elsevier Science B.V. All rights reserved. C1 Fermi Natl Accelerator Lab, Batavia, IL 60510 USA. Univ Autonoma Puebla, Puebla 72570, PUE, Mexico. RP Zimmermann, S (reprint author), Fermi Natl Accelerator Lab, POB 500, Batavia, IL 60510 USA. NR 10 TC 4 Z9 4 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD JUN 1 PY 2001 VL 465 IS 1 BP 224 EP 228 DI 10.1016/S0168-9002(01)00394-1 PG 5 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 444XD UT WOS:000169424600034 ER PT J AU Wirth, BD Caturla, MJ de la Rubia, TD Khraishi, T Zbib, H AF Wirth, BD Caturla, MJ de la Rubia, TD Khraishi, T Zbib, H TI Mechanical property degradation in irradiated materials: A multiscale modeling approach SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS LA English DT Article; Proceedings Paper CT 5th International Conference on Computer Simulation of Radiation Effects in Solids CY JUL 24-28, 2000 CL STATE COLL, PENNSYLVANIA ID MOLECULAR-DYNAMICS; PLASTIC-DEFORMATION; INTERSTITIAL LOOPS; TENSILE PROPERTIES; SINGLE-CRYSTALS; DEFECT CLUSTERS; BCC METALS; EVOLUTION; DAMAGE; ACCUMULATION AB High-energy particle irradiation of low stacking fault energy, face centered cubic (fcc) metals produces significant degradation of mechanical properties, as evidenced in tensile tests performed at or near room temperature. Postirradiation microstructural examination reveals that approximately 90% of the radiation-induced defects in copper are stacking fault tetrahedra (SFT). Radiation damage is an inherently multiscale phenomenon involving processes spanning a wide range of length and time scales. Here we present a multiscale modeling methodology to study the formation and evolution of defect microstructure and the corresponding mechanical property changes under irradiation. At the atomic scale, molecular dynamics (MD) simulations have been used to study the evolution of high energy displacement cascades, SFT formation from vacancy rich regions of displacement cascades, and the interaction of SFTs with moving dislocations. Defect accumulation under irradiation is modeled over diffusional length and time scales by kinetic Monte Carlo (KMC), utilizing a database of displacement cascades generated by MD. The mechanical property changes of the irradiated material are modeled using three-dimensional dislocation dynamics (DD). Key input into the DD includes the spatial distribution of defects produced under irradiation, obtained from KMC. and the fate of dislocation interactions with SFTs, obtained from MD. (C) 2001 Elsevier Science B.V. All rights reserved. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. Washington State Univ, Pullman, WA 99164 USA. RP Wirth, BD (reprint author), Univ Calif Lawrence Livermore Natl Lab, POB 808,L-353, Livermore, CA 94550 USA. RI Caturla, Maria /D-6241-2012; Wirth, Brian/O-4878-2015 OI Caturla, Maria /0000-0002-4809-6553; Wirth, Brian/0000-0002-0395-0285 NR 29 TC 42 Z9 42 U1 0 U2 11 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-583X J9 NUCL INSTRUM METH B JI Nucl. Instrum. Methods Phys. Res. Sect. B-Beam Interact. Mater. Atoms PD JUN PY 2001 VL 180 BP 23 EP 31 DI 10.1016/S0168-583X(01)00392-5 PG 9 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Atomic, Molecular & Chemical; Physics, Nuclear SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 451MR UT WOS:000169806300005 ER PT J AU Morishita, K de la Rubia, TD Kimura, A AF Morishita, K de la Rubia, TD Kimura, A TI Mobility of self-interstitial atom clusters in vanadium, tantalum and copper SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS LA English DT Article; Proceedings Paper CT 5th International Conference on Computer Simulation of Radiation Effects in Solids CY JUL 24-28, 2000 CL STATE COLL, PENNSYLVANIA ID BCC IRON; DYNAMICS; METALS; ENERGY; CASCADE AB Molecular dynamics (MD) simulations were performed to investigate the mobility of isolated self-interstitial atoms (SIAs) and their dusters in V, Ta and Cu. The migration of an isolated SIA is accompanied by rotation of a dumbbell axis to the close-packed direction of metals. The migration of an SIA cluster strongly depends on its structure. A relatively smaller-size cluster can migrate with simultaneous rotation of the axes of SIA pairs in the cluster to the same close-packed direction, which is the glissile configuration of the cluster. The transformation to the glissile configuration takes place more frequently than the dumbbell rotation of an isolated SIA in V and Ta, while it takes place less frequently in Cu. The smaller cluster can still change its diffusion direction. A greater-size cluster in the bcc metals, on the other hand- has the thermally stable form of densely-packed, parallel crowdions. It migrates without any changes of diffusion direction. The migration behavior of 7-SIAs clusters in Ta was also evaluated as a function of tensile and compressive strains. (C) 2001 Elsevier Science B.V. All rights reserved. C1 Kyoto Univ, Inst Adv Energy, Kyoto 6110011, Japan. Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Morishita, K (reprint author), Kyoto Univ, Inst Adv Energy, Kyoto 6110011, Japan. NR 14 TC 6 Z9 6 U1 5 U2 12 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-583X J9 NUCL INSTRUM METH B JI Nucl. Instrum. Methods Phys. Res. Sect. B-Beam Interact. Mater. Atoms PD JUN PY 2001 VL 180 BP 66 EP 71 DI 10.1016/S0168-583X(01)00397-4 PG 6 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Atomic, Molecular & Chemical; Physics, Nuclear SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 451MR UT WOS:000169806300011 ER PT J AU Gao, F Weber, WJ Devanathan, R AF Gao, F Weber, WJ Devanathan, R TI Atomic-scale simulation of displacement cascades and amorphization in beta-SiC SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS LA English DT Article; Proceedings Paper CT 5th International Conference on Computer Simulation of Radiation Effects in Solids CY JUL 24-28, 2000 CL STATE COLL, PA DE computer simulation; displacement cascade; defect production; amorphization; SiC ID IRRADIATION-INDUCED AMORPHIZATION; MOLECULAR-DYNAMICS; SILICON-CARBIDE; INDUCED CRYSTALLINE; AMORPHOUS TRANSITION; COMPUTER-SIMULATION; SINGLE-CRYSTALS; DEFECTS; DAMAGE; METALS AB Molecular dynamics (MD) methods with a modified Tersoff potential have been used to simulate Si displacement cascades with energies up to 50 keV and to compare clustering behavior for Si and Au recoils in beta -SiC (3C). The results show that the lifetime of the thermal spike is very short compared to that in metals, and that the surviving defects are dominated by C interstitials and vacancies for Si displacement cascades. Only 19% of the interstitial population is contained in clusters, with the largest cluster containing only four interstitial atoms for energetic Si recoils. The energy dependence of stable defect formation exhibits a power-law relationship. The high energy Si recoil generates multiple sub-cascades and forms dispersed defect configurations. These results suggest that in-cascade amorphization in SiC doss not occur with any high degree of probability during the lifetime of Si cascades. On the other hand, large disordered domains are created in the cascades produced by 10 keV Au recoils. Structure analysis indicates that these highly disordered regions have amorphous characteristics. The data for the cluster spectra have been used to calculate the relative cross-sections for in-cascade amorphization (or clustering) and defect-stimulated amorphization. The ratios of these cross-sections for Si and Au are in excellent agreement with those derived from a fit of the direct-impact/defect-stimulated model to experimental data. (C) 2001 Elsevier Science B.V. All rights reserved. C1 Pacific NW Natl Lab, MS K893,POB 999, Richland, WA 99352 USA. Indian Inst Technol, Dept Met Engn, Madras 600036, Tamil Nadu, India. RP Gao, F (reprint author), Pacific NW Natl Lab, MS K893,POB 999, Richland, WA 99352 USA. EM fei.gao@pnl.gov RI Weber, William/A-4177-2008; Gao, Fei/H-3045-2012; Devanathan, Ram/C-7247-2008 OI Weber, William/0000-0002-9017-7365; Devanathan, Ram/0000-0001-8125-4237 NR 33 TC 29 Z9 31 U1 0 U2 14 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-583X J9 NUCL INSTRUM METH B JI Nucl. Instrum. Methods Phys. Res. Sect. B-Beam Interact. Mater. Atoms PD JUN PY 2001 VL 180 BP 176 EP 186 DI 10.1016/S0168-583X(01)00415-3 PG 11 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Atomic, Molecular & Chemical; Physics, Nuclear SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 451MR UT WOS:000169806300028 ER PT J AU Gao, F Bacon, DJ Flewitt, PEJ Lewis, TA AF Gao, F Bacon, DJ Flewitt, PEJ Lewis, TA TI The influence of strain on defect generation by displacement cascades in alpha-iron SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS LA English DT Article; Proceedings Paper CT 5th International Conference on Computer Simulation of Radiation Effects in Solids CY JUL 24-28, 2000 CL STATE COLL, PENNSYLVANIA ID MOLECULAR-DYNAMICS; COMPUTER-SIMULATION; METALS; TEMPERATURE; FCC; FE; CU AB Although there have been numerous computer-simulation studies of the damage created by displacement cascades in metals, little attention has been paid to the influence of stress on defect generation in the primary cascade process. In the present work. molecular dynamics (MD) has been used to investigate defect production and clustering by displacement cascades in alpha -iron under uniform tensile strain. Cascades of 10 keV primary-recoil energy have been simulated in a single crystal with strain of 0%, 0.1%, 0.5% or 1% applied along a <1 1 1 > axis, with at least four events modelled for each condition. The results show that the number of interstitial and vacancy defects is smaller in the strained models, particularly for the strain of 0.1%. This decrease in the number of defects is possibly related to the effect of strain on self-interstitial motion. leading to enhanced recombination with vacancies. The number of interstitials in clusters is approximately independent of applied strain, but the fraction of interstitials aligned parallel to the strain axis increases with increasing strain. The effect is small at 0.1%, strain, but most single interstitials are created in this orientation at 0.5% and all single and clustered interstitials are aligned at 1%. These results are discussed in terms of the influence of strain on defect formation energy and the mobility of interstitials. (C) 2001 Elsevier Science B.V. All rights reserved. C1 Univ Liverpool, Dept Engn Mat Sci & Engn, Liverpool L69 3BX, Merseyside, England. Pacific NW Natl Lab, Richland, WA 99352 USA. BNFL Magnox Generat, Technol & Cent Engn Div, Berkeley GL13 9PB, Glos, England. RP Bacon, DJ (reprint author), Univ Liverpool, Dept Engn Mat Sci & Engn, Brownlow Hill, Liverpool L69 3BX, Merseyside, England. RI Gao, Fei/H-3045-2012 NR 11 TC 16 Z9 17 U1 0 U2 6 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-583X J9 NUCL INSTRUM METH B JI Nucl. Instrum. Methods Phys. Res. Sect. B-Beam Interact. Mater. Atoms PD JUN PY 2001 VL 180 BP 187 EP 193 DI 10.1016/S0168-583X(01)00416-5 PG 7 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Atomic, Molecular & Chemical; Physics, Nuclear SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 451MR UT WOS:000169806300029 ER PT J AU Moura, CS Motta, AT Lam, NQ Amaral, L AF Moura, CS Motta, AT Lam, NQ Amaral, L TI Atomistic simulations of point defects in ZrNi intermetallic compounds SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS LA English DT Article; Proceedings Paper CT 5th International Conference on Computer Simulation of Radiation Effects in Solids CY JUL 24-28, 2000 CL STATE COLL, PENNSYLVANIA ID INDUCED AMORPHIZATION; ELECTRON-IRRADIATION; TRANSITION; METALS; NICKEL; NIZR2 AB The properties of point defects, including stable configurations, formation and migration energies, and migration mechanisms. in the ZrNi and Zr2Ni intermetallic compounds were simulated using molecular dynamics and statics, in conjunction with interatomic potentials derived from the Embedded Atom Method. We describe a method to calculate the formation energy of point defects from the program and apply the method to ZrNi and Zr2Ni. The results showed that vacancies are most stable in the Ni sublattice, with formation energy of 0.83 and 0.61 eV in ZrNi and Zr2Ni, respectively. Zr vacancies are unstable in both compounds; they spontaneously decay to pairs of Ni vacancy and antisite defect. The interstitial configurations and formation energies were also calculated, with similar behaviors. In ZrNi, vacancy migration occurs preferentially in the [0 2 5] and [1 0 0] directions, with migration energy of 0.67 and 0.73 eV, respectively, and is essentially a two-dimensional process, in the (001) plane. In Zr2Ni. vacancy migration is one-dimensional, occurring in the [0 0 1] direction, with a migration energy of 0.67 eV. In both compounds, the presence of Ni antisite defects decreases the Ni vacancy migration energy by up to a factor-of-three, and facilitates three-dimensional motion. (C) 2001 Elsevier Science B.V. All rights reserved. C1 Univ Fed Rio Grande Sul, Inst Fis, BR-90000 Porto Alegre, RS, Brazil. Penn State Univ, Dept Mech & Nucl Engn, University Pk, PA 16802 USA. Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. RP Moura, CS (reprint author), Univ Fed Rio Grande Sul, Inst Fis, Caixa Postal 15051, BR-90000 Porto Alegre, RS, Brazil. RI Moura, Cassio/E-2604-2013 NR 18 TC 3 Z9 3 U1 0 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-583X J9 NUCL INSTRUM METH B JI Nucl. Instrum. Methods Phys. Res. Sect. B-Beam Interact. Mater. Atoms PD JUN PY 2001 VL 180 BP 257 EP 264 DI 10.1016/S0168-583X(01)00426-8 PG 8 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Atomic, Molecular & Chemical; Physics, Nuclear SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 451MR UT WOS:000169806300039 ER PT J AU Gao, F Bylaska, EJ Weber, WJ Corrales, LR AF Gao, F Bylaska, EJ Weber, WJ Corrales, LR TI Native defect properties in beta-SiC: Ab initio and empirical potential calculations SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS LA English DT Article; Proceedings Paper CT 5th International Conference on Computer Simulation of Radiation Effects in Solids CY JUL 24-28, 2000 CL STATE COLL, PENNSYLVANIA DE Ab initio calculation; molecular dynamics; defect properties; SiC ID DISPLACEMENT CASCADES; SILICON-CARBIDE; ENERGIES; SIMULATIONS; METALS AB There is considerable ambiguity regarding the formation of native defects and their clusters in silicon carbide (SiC), since different empirical potentials give different results. particular for the stability of interstitial configurations. Density functional theory (DFT) is used to study the formation and properties of native defects in beta -SiC. The DFT results are compared with those calculated by molecular dynamics (MD) simulations using the Tersoff potentials, with modified cut-off distances and parameters obtained from the literature. The formation energy of vacancies and antisite defects obtained by DFT calculations are in good agreement with those given by the Tersoff potential, regardless of the cut-off distances, but for interstitials there is a disparity between the two methods, depending on the cut-off distances used in the Tersoff potential. The present results provide guidelines for evaluating the quality and fit of empirical potentials for large-scale simulations of irradiation damage (displacement cascades) and point defect migration (recombination or annealing) in SiC. (C) 2001 Elsevier Science B.V. All rights reserved. C1 Pacific NW Natl Lab, Richland, WA 99352 USA. RP Gao, F (reprint author), Pacific NW Natl Lab, MS K8-93,POB 999, Richland, WA 99352 USA. RI Weber, William/A-4177-2008; Gao, Fei/H-3045-2012 OI Weber, William/0000-0002-9017-7365; NR 17 TC 37 Z9 37 U1 1 U2 13 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-583X J9 NUCL INSTRUM METH B JI Nucl. Instrum. Methods Phys. Res. Sect. B-Beam Interact. Mater. Atoms PD JUN PY 2001 VL 180 BP 286 EP 292 DI 10.1016/S0168-583X(01)00430-X PG 7 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Atomic, Molecular & Chemical; Physics, Nuclear SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 451MR UT WOS:000169806300043 ER PT J AU Shores, EF AF Shores, EF TI Data updates for the SOURCES-4A computer code SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS LA English DT Article DE alpha reactions; spontaneous fission; actinides; neutron production; Watt spectra; data library ID FISSION NEUTRON-SPECTRA AB The SOURCES decay data library, tape5, was updated to include spontaneous fission information for Cf-252 Decay information for the data library was also updated for the 43 isotopes and isomers having Watt fission spectra parameters. Future work will update the remainder of the nuclides. Submitted to the Radiation Safety Information Computational Center, the distributor of the computer code, this work will upgrade SOURCES from version 4A to 4B. (C) 2001 Elsevier Science B.V. All rights reserved. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Shores, EF (reprint author), Univ Calif Los Alamos Natl Lab, Mail Stop K483, Los Alamos, NM 87545 USA. NR 15 TC 9 Z9 9 U1 1 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-583X J9 NUCL INSTRUM METH B JI Nucl. Instrum. Methods Phys. Res. Sect. B-Beam Interact. Mater. Atoms PD JUN PY 2001 VL 179 IS 1 BP 78 EP 82 DI 10.1016/S0168-583X(00)00694-7 PG 5 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Atomic, Molecular & Chemical; Physics, Nuclear SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 435WM UT WOS:000168905200012 ER PT J AU Nelson, RO Chadwick, MB Michaudon, A Young, PG AF Nelson, RO Chadwick, MB Michaudon, A Young, PG TI High-resolution measurements and calculations of photon-production cross sections for O-16(n,x gamma) reactions induced by neutrons with energies between 4 and 200 MeV SO NUCLEAR SCIENCE AND ENGINEERING LA English DT Article ID LIGHT-NUCLEI A=16-17; DETECTOR; OXYGEN; SCATTERING; O-16 AB Photon-production data from neutron-induced reactions with oxygen are important over a wide range of neutron energies for many applied purposes. The quality of existing data is nor sufficient for many applications as evident from the lack of agreement between various data sets, the rather large uncertainties quoted, and the dearth of angular-distribution data. Moreover, measurements of these reactions were rarely made above 15 MeV. To address these data needs, the high-energy pulsed neutron source at the Weapons Neutron Research Facility at the Los Alamos Neutron Science Center was used to measure photon-production data over a wide neutron-energy range. The gamma rays were detected with two high-resolution germanium detectors. Several measurements were made with these detectors at different locations to obtain data at seven angles. Excitation functions and angular-distribution data have been extracted for 24 gamma rays produced in neutron-induced reactions on oxygen. The data are presented and compared with previous measurements and with cross-section calculations. The data reported here are the basis for a new evaluation of neutron-induced reactions with oxygen; furthermore, the photon-production results have been validated through comparison with independent measurements of emitted-neutron spectra in inelastic O-16(n, n ') reactions at 14 MeV. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Los Alamos Natl Lab, Mail Stop H855,LANSCE 3, Los Alamos, NM 87545 USA. EM RNelson@lanl.gov NR 87 TC 15 Z9 15 U1 0 U2 0 PU AMER NUCLEAR SOC PI LA GRANGE PK PA 555 N KENSINGTON AVE, LA GRANGE PK, IL 60526 USA SN 0029-5639 EI 1943-748X J9 NUCL SCI ENG JI Nucl. Sci. Eng. PD JUN PY 2001 VL 138 IS 2 BP 105 EP 144 PG 40 WC Nuclear Science & Technology SC Nuclear Science & Technology GA 430FJ UT WOS:000168563600001 ER PT J AU Williams, ML Broadhead, BL Parks, CV AF Williams, ML Broadhead, BL Parks, CV TI Eigenvalue sensitivity theory for resonance-shielded cross sections SO NUCLEAR SCIENCE AND ENGINEERING LA English DT Article AB A method is presented to compute sensitivity coefficients far the eigenvalue of a critical assembly, including implicit effects associated with changes in resonance-shielded multigroup cross sections. Two alternative approaches, based on a forward and an adjoint solution, respectively, are developed to determine the effect of perturbations on the weight function used in group averaging of resonance cross sections. The forward method uses an automated methodology to compute the flux derivative with respect to various cross-section processing parameters. The adjoint method introduces adjoint equations far a multigroup cross-section functional and presents adjoint slowing-down equations for two common methods of resonance self-shielding. Expressions are presented for sensitivity coefficients of self-shielded group cross sections. These sensitivity coefficients are combined with conventional eigenvalue sensitivity coefficients to obtain a general perturbation expression for the multiplication factor. An example application determines the sensitivity of the critical eigenvalue to hydrogen density changes in a homogeneous sphere containing low-enriched uranium, it is shown that changes in (238)U-shielded cross sections caused by perturbations in hydrogen concentrations are important components in the overall eigenvalue sensitivity coefficient, which is predicted well by the developed method. C1 Louisiana State Univ, Dept Phys & Astron, Baton Rouge, LA 70803 USA. Oak Ridge Natl Lab, Computat Phys & Engn Div, Oak Ridge, TN 37831 USA. RP Williams, ML (reprint author), Louisiana State Univ, Dept Phys & Astron, Baton Rouge, LA 70803 USA. EM parkscv@ornl.gov OI Parks, Cecil/0000-0003-0323-8447 NR 24 TC 20 Z9 21 U1 1 U2 4 PU AMER NUCLEAR SOC PI LA GRANGE PK PA 555 N KENSINGTON AVE, LA GRANGE PK, IL 60526 USA SN 0029-5639 J9 NUCL SCI ENG JI Nucl. Sci. Eng. PD JUN PY 2001 VL 138 IS 2 BP 177 EP 191 PG 15 WC Nuclear Science & Technology SC Nuclear Science & Technology GA 430FJ UT WOS:000168563600004 ER PT J AU Verbeke, JM Chen, AS Vujic, JL Leung, KN AF Verbeke, JM Chen, AS Vujic, JL Leung, KN TI Optimization of beam-shaping assemblies for BNCS using the high-energy neutron sources D-D and D-T SO NUCLEAR TECHNOLOGY LA English DT Article ID CAPTURE SYNOVECTOMY; RADIATION SYNOVECTOMY; THERAPY AB Boron neutron capture synovectomy is a novel approach for the treatment of rheumatoid arthritis. The goal of the treatment is the ablation of diseased synovial membranes in articulating joints. The treatment of knee joints is the focus of this work. A method was developed, as discussed previously, to predict the dose distribution in a knee joint from any neutron and photon beam spectra incident on the knee. This method is validated and used to design moderators for the deuterium-deuterium (D-D) and deuterium-tritium (D-T) neutron sources. Treatment times >2 h were obtained with the D-D reaction. They could potentially be reduced if the B-10 concentration in the synovium was increased. For D-T neutrons, high therapeutic ratios and treatment times <5 min were obtained for neutron yields of 10(14) s(-1) This treatment time makes the D-T reaction attractive for boron neutron capture synovectomy. C1 Univ Calif Berkeley, Dept Nucl Engn, Berkeley, CA 94720 USA. Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. RP Verbeke, JM (reprint author), Univ Calif Berkeley, Dept Nucl Engn, Berkeley, CA 94720 USA. NR 16 TC 1 Z9 1 U1 0 U2 2 PU AMER NUCLEAR SOCIETY PI LA GRANGE PK PA 555 N KENSINGTON AVENUE, LA GRANGE PK, IL 60525 USA SN 0029-5450 J9 NUCL TECHNOL JI Nucl. Technol. PD JUN PY 2001 VL 134 IS 3 BP 278 EP 293 PG 16 WC Nuclear Science & Technology SC Nuclear Science & Technology GA 436CX UT WOS:000168919900005 ER PT J AU Vasiliskov, VA Prokopenko, DV Mirzabekov, AD AF Vasiliskov, VA Prokopenko, DV Mirzabekov, AD TI Parallel multiplex thermodynamic analysis of coaxial base stacking in DNA duplexes by oligodeoxyribonucleotide microchips SO NUCLEIC ACIDS RESEARCH LA English DT Article ID THERMAL-STABILITY; AQUEOUS-SOLUTION; OLIGONUCLEOTIDE MICROCHIPS; HYBRIDIZATION; PARAMETERS; HELIXES; NMR; RNA; IMMOBILIZATION; DISPERSION AB Parallel thermodynamic analysis of the coaxial stacking effect of two bases localized in one strand of DNA duplexes has been performed. Oligonucleotides were immobilized in an array of three-dimensional polyacrylamide gel pads of microchips (MAGIChips (TM)). The stacking effect was studied for all combinations of two bases and assessed by measuring the increase in melting temperature and in the free energy of duplexes formed by 5mers stacked to microchip-immobilized 10mers, For any given interface, the effect was studied for perfectly paired bases, as well as terminal mismatches, single base overlaps, single and double gaps, and modified terminal bases, Thermodynamic parameters of contiguous stacking determined by using microchips closely correlated with data obtained in solution, The extension of immobilized oligonucleotides with 5,6-dihydroxyuridine, a urea derivative of deoxyribose, or by phosphate, decreased the stacking effect moderately, while extension with FITC or Texas Red virtually eliminated stacking. The extension of the immobilized oligonucleotides with either acridine or 5-nitroindole increased stacking to mispaired bases and in some GC-rich interfaces. The measurements of stacking parameters were performed in different melting buffers. Although melting temperatures of AT- and CC-rich oligonucleotides in 5 M tetramethylammonium chloride were equalized, the energy of stacking interaction was significantly diminished. C1 Russian Acad Sci, VA Engelhardt Mol Biol Inst, Moscow 119991, Russia. Moscow Inst Phys & Technol, Dolgoprudnyi 141700, Russia. Argonne Natl Lab, Biochip Technol Ctr, Argonne, IL 60439 USA. RP Mirzabekov, AD (reprint author), Russian Acad Sci, VA Engelhardt Mol Biol Inst, Vavilov Str 32, Moscow 119991, Russia. NR 43 TC 55 Z9 56 U1 1 U2 5 PU OXFORD UNIV PRESS PI OXFORD PA GREAT CLARENDON ST, OXFORD OX2 6DP, ENGLAND SN 0305-1048 J9 NUCLEIC ACIDS RES JI Nucleic Acids Res. PD JUN 1 PY 2001 VL 29 IS 11 BP 2303 EP 2313 DI 10.1093/nar/29.11.2303 PG 11 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA 440EU UT WOS:000169163600012 PM 11376149 ER PT J AU Brudno, M Gelfand, MS Spengler, S Zorn, M Dubchak, I Conboy, JG AF Brudno, M Gelfand, MS Spengler, S Zorn, M Dubchak, I Conboy, JG TI Computational analysis of candidate intron regulatory elements for tissue-specific alternative pre-mRNA splicing SO NUCLEIC ACIDS RESEARCH LA English DT Article ID TRACT-BINDING-PROTEIN; NEURON-SPECIFIC ISOFORM; MESSENGER-RNA; DEVELOPMENTAL CONSEQUENCES; SKELETAL-MUSCLE; GENE STRUCTURE; CHAIN-B; BRAIN; EXPRESSION; ENHANCER AB Alternative pre-mRNA splicing is a major cellular process by which functionally diverse proteins can be generated from the primary transcript of a single gene, often in tissue-specific patterns. The current study investigates the hypothesis that splicing of tissue-specific alternative exons is regulated in part by control sequences in adjacent introns and that such elements may be recognized via computational analysis of exons sharing a highly specific expression pattern. We have identified 25 brain-specific alternative cassette exons, compiled a dataset of genomic sequences encompassing these exons and their adjacent introns and used word contrast algorithms to analyze key features of these nucleotide sequences. By comparison to a control group of constitutive exons, brain-specific exons were often found to possess the following: divergent 5' splice sites; highly pyrimidine-rich upstream introns; a paucity of GGG motifs in the downstream intron; a highly statistically significant over-representation of the hexanucleotide UGCAUG in the proximal downstream intron, UGCAUG was also found at a high frequency downstream of a smaller group of muscle-specific exons, Intriguingly, UGCAUG has been identified previously in a few intron splicing enhancers. Our results indicate that this element plays a much wider role than previously appreciated in the regulated tissue-specific splicing of many alternative exons. C1 NERSC, Berkeley, CA 94720 USA. Lawrence Berkeley Lab, Div Life Sci, Berkeley, CA 94720 USA. State Sci Ctr Biotechnol NII Genetika, Moscow 113545, Russia. Stanford Univ, Dept Comp Sci, Stanford, CA 94305 USA. RP Dubchak, I (reprint author), NERSC, Bldg 84-171,1 Cyclotron Rd, Berkeley, CA 94720 USA. RI Gelfand, Mikhail/F-3425-2012 FU NHLBI NIH HHS [HL45821, R01 HL045182] NR 68 TC 89 Z9 90 U1 0 U2 0 PU OXFORD UNIV PRESS PI OXFORD PA GREAT CLARENDON ST, OXFORD OX2 6DP, ENGLAND SN 0305-1048 J9 NUCLEIC ACIDS RES JI Nucleic Acids Res. PD JUN 1 PY 2001 VL 29 IS 11 BP 2338 EP 2348 DI 10.1093/nar/29.11.2338 PG 11 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA 440EU UT WOS:000169163600015 PM 11376152 ER PT J AU Burton, RK Snodgrass, JJ Gifford-Gonzalez, D Guilderson, T Brown, T Koch, PL AF Burton, RK Snodgrass, JJ Gifford-Gonzalez, D Guilderson, T Brown, T Koch, PL TI Holocene changes in the ecology of northern fur seals: insights from stable isotopes and archaeofauna SO OECOLOGIA LA English DT Article DE Holocene; Callorhinus ursinus; stable isotopes; breeding; migration ID TROPHIC RELATIONSHIPS; CARBON ISOTOPES; MARINE; CALIFORNIA; EVOLUTION; PINNIPEDS; NITROGEN; PACIFIC; CO2; DELTA-C-13 AB The remains of northern fur seals (Callorhinus ursinus) are among the most abundant of pinniped elements recovered from mainland coastal archaeological sites in both California and Oregon. This is surprising as all contemporary northern fur seals breed exclusively on offshore islands, primarily at high latitudes, and the species is otherwise pelagic. The vulnerability of these animals to human predation suggests that either humans were foraging much further offshore than has been presumed or alternatively that the ecology of these animals has shifted during the late Holocene. We used isotopic and archaeofaunal analysis of the remains of pinnipeds from the middle to late Holocene of central and northern California to clarify the breeding and foraging behavior, and migration patterns of these ancient animals. The carbon and nitrogen isotope compositions of ancient northern fur seals reveal that these animals fed as far offshore as they do today, and that they remained at middle latitudes throughout the year. From an archaeological site at Moss Landing, California, we identified 16 skeletal elements from at least 12 very small northern fur seal pups. From another site near Mendocino, California, we identified the remains of at least 6 pups. We estimate the size and age of 5 of the young animals using sex-specific regressions of body length on the short dentary length derived from measurements of modern specimens. Our estimates indicate these ancient pups were substantially smaller, and therefore younger, than modern 3-month-old northern fur seal pups from similar latitudes and their nitrogen isotope compositions suggest they had not been weaned. As present-day northern fur seals do not leave their rookeries until they are at least 4 months old, we consider it highly unlikely that these ancient pups swam to these mainland locations from some distant island rookery. While there are numerous nearshore rocky outcrops along the Mendocino Coast, which may have supported small breeding colonies, the Moss Landing site is centered on a 40-km-long sandy beach, and is more than 120 km from what at the time were the nearest offshore islands. We conclude that northern fur seal adult females, subadults, and pups whose remains were recovered at the Moss Landing archaeological site must have been taken at a mainland rookery. Evidence that northern fur seals once bred on the mainland at this central California location suggests that the abundant remains of these animals at numerous other archaeological sites along the California coast also reflect the presence of nearby mainland rookeries. Based on the relative abundance of their remains in ancient human occupation sites and the widespread distribution of sites where their remains have been found, it appears that northern fur seals were once the predominant pinniped throughout a region where they now only rarely occur. Furthermore, their presence along the central and northern California coasts appears to have once severely limited the distribution of other pinnipeds, which are now common to the region. C1 Moss Landing Marine Labs, Moss Landing, CA 95039 USA. Northwestern Univ, Dept Anthropol, Evanston, IL 60208 USA. Univ Calif Santa Cruz, Dept Anthropol, Santa Cruz, CA 95064 USA. Harvard Univ, Dept Earth & Planetary Sci, Cambridge, MA 02138 USA. Univ Calif Lawrence Livermore Natl Lab, Ctr Accelerator Mass Spectrometry, Livermore, CA 94551 USA. Univ Calif Santa Cruz, Dept Earth Sci, Santa Cruz, CA 95064 USA. RP Burton, RK (reprint author), Moss Landing Marine Labs, Pob 450, Moss Landing, CA 95039 USA. NR 49 TC 64 Z9 66 U1 1 U2 10 PU SPRINGER-VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 USA SN 0029-8549 J9 OECOLOGIA JI Oecologia PD JUN PY 2001 VL 128 IS 1 BP 107 EP 115 DI 10.1007/s004420100631 PG 9 WC Ecology SC Environmental Sciences & Ecology GA 447VE UT WOS:000169592500014 ER PT J AU Karunamuni, J Stitzer, KE Eastwood, D Albert, KJ Walt, DR Brown, SB Myrick, ML AF Karunamuni, J Stitzer, KE Eastwood, D Albert, KJ Walt, DR Brown, SB Myrick, ML TI Interference filter refinement for artificial nose fluorescence sensing SO OPTICAL ENGINEERING LA English DT Article DE fluorescence; interference filter; artificial nose; filter synthesis ID OPTICAL SENSOR ARRAYS; THIN-FILM SYNTHESIS; IMAGING FIBER; POLYMER-FILMS; RECOGNITION; SYSTEM AB Optical interference coatings are used in filter-based T-format fluorimeters to make beamsplitters, bandpasses, and bandblocking filters that separate excitation and emission signals. Commercially available fitters usually perform well in these applications, but better performance may be possible if the system of optical filters is tailored to the specific analysis. We provide a general method for designing optical filters for the optical train of a specific fluorescence sensor system simultaneously using two light-emitting diode (LED) excitation sources (blue and green) and two different fluorescent indicators. We approach the problem of designing the optics of the system by first constructing a hypothetical target spectrum for each filter using the optical spectrum of the excitation source, and the excitation and emission spectra of the fluorescence sensors. Structural designs for Nb2O5/SiO2 multilayer interference filters are then synthesized. An iterative evaluation procedure is then used to improve the performance of the system for minimal leakage of the excitation sources onto our detector array. We also provide experimental results for the construction of these filters using reactive magnetron sputtering, (C) 2001 Society of Photo-Optical Instrumentation Engineers. C1 Univ S Carolina, Dept Chem, Columbia, SC 29208 USA. Tufts Univ, Dept Chem, Max Tishler Lab Organ Chem, Medford, MA 02155 USA. Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Karunamuni, J (reprint author), Univ S Carolina, Dept Chem, Columbia, SC 29208 USA. OI Myrick, Michael/0000-0002-6905-0925 NR 21 TC 4 Z9 4 U1 0 U2 2 PU SPIE-INT SOCIETY OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98225 USA SN 0091-3286 J9 OPT ENG JI Opt. Eng. PD JUN PY 2001 VL 40 IS 6 BP 888 EP 895 DI 10.1117/1.1367255 PG 8 WC Optics SC Optics GA 449RU UT WOS:000169701600002 ER PT J AU Dahan, M Laurence, T Pinaud, F Chemla, DS Alivisatos, AP Sauer, M Weiss, S AF Dahan, M Laurence, T Pinaud, F Chemla, DS Alivisatos, AP Sauer, M Weiss, S TI Time-gated biological imaging by use of colloidal quantum dots SO OPTICS LETTERS LA English DT Article ID EUROPIUM; CHELATE AB The long (but not too long) fluorescence lifetime of CdSe semiconductor quantum dots was exploited to enhance fluorescence biological imaging contrast and sensitivity by time-gated detection. Significant and selective reduction of the autofluorescence contribution to the overall image was achieved, and enhancement of the signal-to-background ratio by more than an order of magnitude was demonstrated. (C) 2001 Optical Society of America. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. Univ Heidelberg, Inst Phys Chem, D-69120 Heidelberg, Germany. RP Dahan, M (reprint author), Ecole Normale Super, Lab Kastler Brossel, 24 Rue Lhomond, F-75231 Paris, France. RI Pinaud, Fabien/F-2306-2010; Laurence, Ted/E-4791-2011; Dahan, Maxime /F-1740-2010; weiss, shimon/B-4164-2009; Alivisatos , Paul /N-8863-2015; Sauer, Markus/C-4378-2017 OI Laurence, Ted/0000-0003-1474-779X; weiss, shimon/0000-0002-0720-5426; Alivisatos , Paul /0000-0001-6895-9048; Sauer, Markus/0000-0002-1692-3219 NR 9 TC 233 Z9 240 U1 4 U2 52 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA SN 0146-9592 J9 OPT LETT JI Opt. Lett. PD JUN 1 PY 2001 VL 26 IS 11 BP 825 EP 827 DI 10.1364/OL.26.000825 PG 3 WC Optics SC Optics GA 436EU UT WOS:000168924200023 PM 18040463 ER PT J AU Kolman, DG Taylor, TN Park, YS Stan, M Butt, DP Maggiore, CJ Tesmer, JR Havrilla, GJ AF Kolman, DG Taylor, TN Park, YS Stan, M Butt, DP Maggiore, CJ Tesmer, JR Havrilla, GJ TI Gallium-suboxide attack of stainless steel and nickel alloys at 800-1200 degrees C SO OXIDATION OF METALS LA English DT Article DE gallium oxide; gallium suboxide; 304 stainless steel; 316 stainless steel; Hastelloy C-276 ID LIQUID-METAL EMBRITTLEMENT; HYDROGEN; BEHAVIOR; FRACTURE; OXIDE; AL AB Failure of furnace parts composed of stainless steel or nickel-base alloys has been observed following treatment of gallium-containing compounds at 800 to 1200 degreesC. This work examines the effect of gallium suboxide (Ga2O) and gallium oxide (Ga2O3) on the chemical and mechanical properties of 304 SS, 316 SS, and Hastelloy C-276 in an effort to elucidate a failure mechanism. Results indicate that all three materials are subject to attack by gallium compounds. Elemental segregation, oxidation, and Ga uptake all occur following exposure. Ga2O gas appears to play the dominant role in alloy attack under reducing conditions. Increasing temperature is shown to increase the magnitude of attack, as measured by, oxide thickness and gallium-metal uptake. Calculations of the system thermodynamics suggest that Cr, Mn, Si, and TP alloying components are responsible for metal oxidation and concurrent gallium absorption. A homogeneous, large (> 30 wt.%) gallium uptake resulted in brittle failure of 304 SS. Therefore, exposure to gallium compounds can result in premature failure of iron- and nickel-base structural alloys. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Kolman, DG (reprint author), Univ Calif Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. RI Butt, Darryl/B-7480-2008 OI Butt, Darryl/0000-0003-4501-8864 NR 23 TC 3 Z9 3 U1 1 U2 6 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 JUN PY 2001 VL 55 IS 5-6 BP 437 EP 470 DI 10.1023/A:1010303730571 PG 34 WC Metallurgy & Metallurgical Engineering SC Metallurgy & Metallurgical Engineering GA 428CX UT WOS:000168444500003 ER PT J AU Greene, GA Finfrock, CC AF Greene, GA Finfrock, CC TI Oxidation of Inconel 718 in air at high temperatures SO OXIDATION OF METALS LA English DT Article DE air oxidation; parabolic; passivation; Inconel 718; high temperature ID ELEVATED-TEMPERATURES; ALLOYS SUPERALLOYS AB Experiments were conducted with Inconel 718 at high temperatures to evaluate the rate of oxidation of the material oner as wide a temperature range as possible, as ave(l as to determine the high-temperature failure limit of the material. Samples of Inconel 718 were inserted into preheated furnaces at temperatures ranging from 973 to 1620 K and oxidized in air for varying periods of time. After being oxidized in air at a constant temperature for the prescribed rime and then being allowed to cool, the samples were reweighed to determine their mass gain due to the uptake of oxygen,gen. From these mass-gain measurements, it was possible to identify three regimes of oxidation for Inconel 718: a low-temperature regime in which the samples behaved as if passivated after an initial period of transient oxidation, an intermediate-temperature regime in which the rate of oxidation was limited by diffusion and exhibited a constant parabolic rate dependence, and a high-temperature regime in which material deformation and damage accompanied an accelerated oxidation rate above the parabolic regime. C1 Brookhaven Natl Lab, Upton, NY 11973 USA. RP Greene, GA (reprint author), Brookhaven Natl Lab, Upton, NY 11973 USA. NR 18 TC 32 Z9 36 U1 5 U2 29 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 JUN PY 2001 VL 55 IS 5-6 BP 505 EP 521 DI 10.1023/A:1010359815550 PG 17 WC Metallurgy & Metallurgical Engineering SC Metallurgy & Metallurgical Engineering GA 428CX UT WOS:000168444500006 ER PT J AU Westmacott, KH Hinderberger, S Dahmen, U AF Westmacott, KH Hinderberger, S Dahmen, U TI Physical vapour deposition growth and transmission electron microscopy characterization of epitaxial thin metal films on single-crystal Si and Ge substrates SO PHILOSOPHICAL MAGAZINE A-PHYSICS OF CONDENSED MATTER STRUCTURE DEFECTS AND MECHANICAL PROPERTIES LA English DT Article ID IONIZED-CLUSTER BEAM; ATOMIC-STRUCTURE; GRAIN-BOUNDARY; AL FILMS; INTERPHASE BOUNDARIES; GEOMETRIC FACTORS; ROOM-TEMPERATURE; BUFFER LAYERS; SI(111); CU AB Epitaxial fcc, bcc and hcp metal and alloy films were grown in high vacuum by physical vapour deposition at high rate ('flash' deposition) on the (111), (110) and (100) surfaces of Si and Ge at different deposition temperatures. The resulting epitaxial relationships and morphological features of these films were characterized by transmission electron microscopy and diffraction. Simple epitaxial relationships were found mainly for the fcc metals that form binary eutectic systems with Si and Ge. Of these, Ag exhibited exceptional behaviour by forming in a single crystal cube-cube relationship on all six semiconduct or surfaces. Al and Au both formed bicrystal films on (100) substrates but differed in their behaviours on (111) substrates. Silicide formers such as the fcc metals Cu and Ni, as well as all bcc and hcp metals investigated, did not adopt epitaxial relationships on most semiconduct or substrates. However, epitaxial single-crystal, bicrystal and tricrystal films of several metals and alloys could be grown by using a Ag buffer layer. The factors controlling the epitaxial growth of metal films are discussed in the light of the observations and compared with the predictions of established models for epitaxial relationships. It is concluded that epitaxial films can be grown easily if the film forms a simple eutectic or monotectic system with the substrate. The epitaxial relationships of those films depend on crystallographic factors for metal-metal epitaxy and on the substrate surface structure for metal-semiconductor epitaxy. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Natl Ctr Electron Microscopy, Berkeley, CA 94720 USA. RP Westmacott, KH (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Natl Ctr Electron Microscopy, 1 Cyclotron Rd, Berkeley, CA 94720 USA. NR 90 TC 19 Z9 19 U1 2 U2 18 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 JUN PY 2001 VL 81 IS 6 BP 1547 EP 1578 PG 32 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering; Physics, Applied; Physics, Condensed Matter SC Materials Science; Metallurgy & Metallurgical Engineering; Physics GA 442LG UT WOS:000169286800007 ER PT J AU Millsaps, JF Bruce, BD Lee, JW Greenbaum, E AF Millsaps, JF Bruce, BD Lee, JW Greenbaum, E TI Nanoscale photosynthesis: Photocatalytic production of hydrogen by platinized photosystem I reaction centers SO PHOTOCHEMISTRY AND PHOTOBIOLOGY LA English DT Article AB A study of the photocatalytic production of molecular hydrogen from platinized photosystem I (PSI) reaction centers is reported. At pH 7 and room temperature metallic platinum was photoprecipitated at the reducing end of PSI according to the reaction, [PtCl6](2-) + 4e(-) + hv --> Pt down arrow + 6Cl,where it interacted with photogenerated PSI electrons and catalyzed the evolution of molecular hydrogen. The reaction mixture included purified spinach PSI reaction centers, sodium ascorbate and spinach plastocyanin, Experimental data on real-time catalytic platinum formation as measured by the onset and rates of hydrogen photoevolution as a function of time are presented. The key objective of the experiments was demonstration of functional nanoscale surface metalization at the reducing end of isolated PSI by substituting negatively charged [PtCl6](2-) for negatively charged ferredoxin, the naturally occurring water-soluble electron carrier in photosynthesis. The data are interpreted in terms of electrostatic interactions between [PtCl6](2-) and the positively charged surface of psaD, the ferredoxin docking site situated at the stromal interface of the photosynthetic membrane and which is presumably retained in our PSI preparation. A discussion of the rates of hydrogen evolution in terms of the structural components of the various PSI preparations as well as of those of the intact thylakoid membranes is presented. C1 Oak Ridge Natl Lab, Div Chem Technol, Oak Ridge, TN 37831 USA. Maryville Coll, Dept Chem, Maryville, TN USA. Univ Tennessee, Grad Sch Genome Sci & Technol, Knoxville, TN USA. Univ Tennessee, Dept Biochem Cellular & Mol Biol, Knoxville, TN USA. Univ Tennessee, Ctr Environm Biotechnol, Knoxville, TN 37932 USA. RP Greenbaum, E (reprint author), Oak Ridge Natl Lab, Div Chem Technol, PO 2008,Bldg 4500N, Oak Ridge, TN 37831 USA. EM greenbaum@ornl.gov NR 20 TC 46 Z9 46 U1 0 U2 14 PU WILEY-BLACKWELL PI HOBOKEN PA 111 RIVER ST, HOBOKEN 07030-5774, NJ USA SN 0031-8655 EI 1751-1097 J9 PHOTOCHEM PHOTOBIOL JI Photochem. Photobiol. PD JUN PY 2001 VL 73 IS 6 BP 630 EP 635 DI 10.1562/0031-8655(2001)073<0630:NPPPOH>2.0.CO;2 PG 6 WC Biochemistry & Molecular Biology; Biophysics SC Biochemistry & Molecular Biology; Biophysics GA 441TY UT WOS:000169246700008 PM 11421068 ER PT J AU Paranthaman, M Thompson, JR Christen, DK AF Paranthaman, M Thompson, JR Christen, DK TI Effect of carbon-doping in bulk superconducting MgB2 samples SO PHYSICA C LA English DT Article DE MgB2 superconductors; bulk samples; carbon-doping; X-ray studies; Meissner state magnetization AB Bulk superconducting samples of MgB2 were prepared by solid state reaction of stoichiometric quantities of Mg turnings and B in a sealed Ta cylinder at 890 degreesC for 2 h. The "as-synthesized" MgB2 samples had a T-c of 39 K, as defined as the onset of diamagnetism. The crystal symmetry was found to be hexagonal with lattice parameters, a = 3.0856 Angstrom, and c = 3.5199 Angstrom, similar to the literature values. To study the effect of carbon-doping in MgB2 various C-containing samples of I varying from 0 to 1.00 in MgB2-xCx were prepared. Magnetic characterizations indicate that the T, onset is same for pure and C-doped samples for x = 0.05 and 0.10. However, the shielding signal decreased monotonically with C content, apparently due to the presence of carbon on the grain boundaries that isolates grains and prevents flow of supercurrents on the perimeter. Published by Elsevier Science B.V. 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. Univ Tennessee, Dept Phys, Knoxville, TN 37996 USA. RP Paranthaman, M (reprint author), Oak Ridge Natl Lab, Div Chem & Analyt Sci, POB 2008,4500S,MS 6100, Oak Ridge, TN 37831 USA. RI Christen, David/A-9709-2008; Paranthaman, Mariappan/N-3866-2015 OI Paranthaman, Mariappan/0000-0003-3009-8531 NR 20 TC 75 Z9 81 U1 0 U2 11 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4534 J9 PHYSICA C JI Physica C PD JUN 1 PY 2001 VL 355 IS 1-2 BP 1 EP 5 DI 10.1016/S0921-4534(01)00424-5 PG 5 WC Physics, Applied SC Physics GA 442LK UT WOS:000169287100001 ER PT J AU Okram, GS Aoki, H Xu, M Hinks, DG AF Okram, GS Aoki, H Xu, M Hinks, DG TI Vortex lock-in transition in Tl2Ba2CuO6 superconductor and vortex phase diagram SO PHYSICA C-SUPERCONDUCTIVITY AND ITS APPLICATIONS LA English DT Article DE Tl2Ba2CuO6 crystal; CuO planes; flux flow; magneto-resistivity; phase-diagram ID HIGH-TEMPERATURE SUPERCONDUCTORS; HIGH-TC SUPERCONDUCTORS; COUPLED LAYER MODEL; SINGLE-CRYSTAL; MAGNETIC-FIELD; JOSEPHSON VORTICES; YBA2CU3O7-DELTA; DISSIPATION; FILMS; STATE AB Lock-in transition in good quality over-doped Tl(2)BalCuO(6) crystals has been investigated. As the c-axis angle H with the magnetic field H approaches 90 degrees, the Aux Row resistivity rho(theta) exhibits a sharp drop, a dip and a peak. These features were observed for a particular range of H and temperatures T and they have been assigned to the vortex phase transitions of different types. These enabled us to identify the associated vortex phase diagrams, viz, the theta -t and theta -H phase diagrams, where t is the reduced temperature T/T-c. We made an attempt to fit the data with the available theories and to discuss the results. (C) 2001 Elsevier Science B,V, All rights reserved. C1 Natl Res Inst Met, Tsukuba, Ibaraki 305, Japan. Tohoku Univ, Ctr Low Temp Sci, Sendai, Miyagi 98077, Japan. Univ Chicago, James Franck Inst, Chicago, IL 60637 USA. Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. RP Natl Phys Lab, Cryogen & Superconduct Div, Dr KS Krishnan Rd, New Delhi 110012, India. EM okram@csnpl.ren.nic.in NR 38 TC 4 Z9 4 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4534 EI 1873-2143 J9 PHYSICA C JI Physica C PD JUN 1 PY 2001 VL 355 IS 1-2 BP 65 EP 76 DI 10.1016/S0921-4534(00)01773-1 PG 12 WC Physics, Applied SC Physics GA 442LK UT WOS:000169287100009 ER PT J AU Bertulani, CA AF Bertulani, CA TI Electromagnetic interaction of ultrarelativistic heavy ions SO PHYSICAL REVIEW A LA English DT Article ID POSITRON PAIR PRODUCTION; COLLISIONS AB The validity of a delta -function approximation for the electromagnetic interaction of relativistic heavy ions is investigated. The production of e(+)e(-) pairs, with electron capture, is used as a test of the approximation. C1 Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. RP Bertulani, CA (reprint author), Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. NR 10 TC 0 Z9 0 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1050-2947 J9 PHYS REV A JI Phys. Rev. A PD JUN PY 2001 VL 63 IS 6 AR 062706 PG 4 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA 439TZ UT WOS:000169134800037 ER PT J AU Doherty, AC Jacobs, K Jungman, G AF Doherty, AC Jacobs, K Jungman, G TI Information, disturbance, and Hamiltonian quantum feedback control SO PHYSICAL REVIEW A LA English DT Article ID ADAPTIVE PHASE MEASUREMENTS; OPTICAL FEEDBACK; HOMODYNE DETECTION; POSTERIORI STATES; WAVE-EQUATION; SINGLE-ATOM; MECHANICS; SYSTEMS; COHERENCE; POSITION AB We consider separating the problem of designing Hamiltonian quantum feedback control algorithms into a measurement (estimation) strategy and a feedback (control) strategy, and we consider optimizing desirable properties of each under the minimal constraint that the available strength of both is limited. This motivates concepts of information extraction and disturbance that are distinct from those usually considered in quantum information theory. Using these concepts, we identify an information tradeoff in quantum feedback control. C1 CALTECH, Norman Bridge Lab Phys 12 33, Pasadena, CA 91125 USA. Univ Calif Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. RP Doherty, AC (reprint author), CALTECH, Norman Bridge Lab Phys 12 33, Pasadena, CA 91125 USA. RI Jacobs, Kurt/E-7049-2011; Doherty, Andrew/D-1816-2010 OI Jacobs, Kurt/0000-0003-0828-6421; Doherty, Andrew/0000-0002-8069-7754 NR 67 TC 70 Z9 71 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 JUN PY 2001 VL 63 IS 6 AR 062306 DI 10.1103/PhysRevA.63.062306 PG 13 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA 439TZ UT WOS:000169134800022 ER PT J AU Fuchs, CA Jacobs, K AF Fuchs, CA Jacobs, K TI Information-tradeoff relations for finite-strength quantum measurements SO PHYSICAL REVIEW A LA English DT Article ID STATE DISTURBANCE; CRYPTOGRAPHY; NONDEMOLITION; THEOREM; ENTROPY; GAIN AB In this paper we describe a way to quantify the folkloric notion that quantum measurements bring a disturbance to the system being measured. We consider two observers who initially assign identical mixed-state density operators to a two-state quantum system. The question we address is to what extent one observer can. by measurement, increase the purity of his density operator without affecting the purity of the other observer's. If there were no restrictions on the first observer's measurements, then he could carry this out trivially by measuring the initial density operator's eigenbasis. If, however, the allowed measurements are those of finite strength-i.e., those measurements strictly within the interior of the convex set of all measurements-then the issue becomes significantly more complex. We find that for a large class of such measurements the first observer's purity increases the most precisely when there is some loss of purity for the second observer. More generally the tradeoff between the two purities, when it exists, forms a monotonic relation. This tradeoff has potential application to quantum state control and feedback. C1 Univ Calif Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. Bell Labs, Lucent Technol, Murray Hill, NJ 07974 USA. RP Fuchs, CA (reprint author), Univ Calif Los Alamos Natl Lab, Div Theoret, T-8, Los Alamos, NM 87545 USA. RI Jacobs, Kurt/E-7049-2011 OI Jacobs, Kurt/0000-0003-0828-6421 NR 52 TC 71 Z9 71 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 JUN PY 2001 VL 63 IS 6 AR 062305 DI 10.1103/PhysRevA.63.062305 PG 15 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA 439TZ UT WOS:000169134800021 ER PT J AU Kukk, E Snell, G Bozek, JD Cheng, WT Berrah, N AF Kukk, E Snell, G Bozek, JD Cheng, WT Berrah, N TI Vibrational structure and partial rates of resonant Auger decay of the N 1s -> 2 pi core excitations in nitric oxide SO PHYSICAL REVIEW A LA English DT Article ID DEEXCITATION ELECTRON-SPECTROSCOPY; CARBON-MONOXIDE; EXCITED NO; SPECTRA; RESOLUTION; ENERGY; INTERFERENCE; MOLECULES AB High-resolution resonant Auger-electron spectra of NO measured at the N 1s -->2 pi core excitations are presented. The open-shell ground-state electronic configuration of the molecule results in four excited electronic states, three of which are populated in the photoabsorption spectrum, (2)Delta, (2)Sigma (-), and (2)Sigma (+). Electron emission spectra obtained at different vibrational levels of the three N 1s core-excited states of NO are reported. Recent ab initio calculations [J. Chem. Phys. 106, 4038 (1997)] are used to generate theoretical spectra for comparison with the experimental results taking lifetime vibration interference and Auger resonant Raman effects into account. The Auger-electron spectra are decomposed into contributions from different final ionic states for comparison of the calculated and experimental partial Auger decay rates. Revised values for the core-hole lifetime width and Morse potential of the (2)Delta excited state, and for the adiabatic ionization energy of the (1)Delta ionic state are given. C1 Western Michigan Univ, Dept Phys, Kalamazoo, MI 49008 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. Natl Cent Univ, Dept Phys, Chungli 32054, Taoyuan, Taiwan. RP Kukk, E (reprint author), Univ Oulu, Dept Phys Sci, POB 3000, FIN-90014 Oulu, Finland. EM Edwin.Kukk@oulu.fi; JDBozek@lbl.gov RI Bozek, John/E-4689-2010; Bozek, John/E-9260-2010 OI Bozek, John/0000-0001-7486-7238 NR 26 TC 26 Z9 26 U1 0 U2 3 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1050-2947 J9 PHYS REV A JI Phys. Rev. A PD JUN PY 2001 VL 63 IS 6 AR 062702 DI 10.1103/PhysRevA.63.062702 PG 9 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA 439TZ UT WOS:000169134800033 ER PT J AU Nahar, SN Pradhan, AK Zhang, HL AF Nahar, SN Pradhan, AK Zhang, HL TI K-shell dielectronic resonances in photoabsorption: Differential oscillator strengths for Li-like CIV, OVI, and Fe XXIV SO PHYSICAL REVIEW A LA English DT Article ID RECOMBINATION CROSS-SECTIONS; SATELLITE SPECTRA; IRON PROJECT; ATOMIC DATA; IONS; LINES; BEAM; XXV AB Recently x-ray photoabsorption in KLL resonances of O VI was predicted [A. K. Pradhan, Astrophys. J. Lett. 545, L165 (2000)], and detected by the Chandra X-Xay Observatory [J. C. Lee er at, Astrophys. J. Lett. (to be published)]. The required resonance oscillator strengths (f) over bar (r) are evaluated in terms of the differential oscillator strength df/d epsilon that relates bound and continuum absorption. We present the (f) over bar (r) values from radiatively damped and undamped photoionization cross sections for Li-like C, O, and Fe calculated using relativistic the close-coupling Breit-Pauli R-matrix method. The KLL resonances of interest here are 1s2p(P-3(o))2s [P-4(1/2,3/2)o P-2(1/2,3/2)o] and 1s2p(P-1(o))2s [P-2(1/2,3/2)o]. The KLL photoabsorption resonances in Fe XXIV are fully resolved up to natural autoionization profiles. It is demonstrated that the undamped (f) over bar (r) independently yield the resonance radiative decay rates, and thereby provide a precise check on the resolution of photoionization calculations in general. The predicted photoabsorption features should be detectable by the x-ray space observatories and enable column densities in highly ionized astrophysical plasmas to be determined from the calculated (f) over bar (r). The dielectronic satellites may appear as redward broadening of resonance lines in emission and absorption. C1 Ohio State Univ, Dept Astron, Columbus, OH 43210 USA. Univ Calif Los Alamos Natl Lab, Appl Theoret & Computat Phys Div, Los Alamos, NM 87544 USA. RP Nahar, SN (reprint author), Ohio State Univ, Dept Astron, 174 W 18th Ave, Columbus, OH 43210 USA. NR 22 TC 14 Z9 14 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1050-2947 J9 PHYS REV A JI Phys. Rev. A PD JUN PY 2001 VL 63 IS 6 AR 060701 DI 10.1103/PhysRevA.63.060701 PG 4 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA 439TZ UT WOS:000169134800002 ER PT J AU Nayandin, O Kukk, E Wills, AA Langer, B Bozek, JD Canton-Rogan, S Wiedenhoeft, M Cubaynes, D Berrah, N AF Nayandin, O Kukk, E Wills, AA Langer, B Bozek, JD Canton-Rogan, S Wiedenhoeft, M Cubaynes, D Berrah, N TI Angle-resolved two-dimensional mapping of electron emission from the inner-shell 2p excitations in Cl-2 SO PHYSICAL REVIEW A LA English DT Article ID RESONANT AUGER DECAY; ANGULAR-DISTRIBUTION; HIGH-RESOLUTION; EXCITED-STATES; HCL; MOLECULES; DCL; CO; PHOTOEXCITATION; SPECTROSCOPY AB Angle-resolved Auger and valence photoelectron spectra were measured over a 14-eV photon energy range across the Cl-2 2p ionization thresholds. The measurements were carried out using highly efficient time-of-flight spectrometers coupled with photons from the Atomic and Molecular undulator beamline of the Advanced Light Source and an advanced data-acquisition system. Auger-electron spectra of 2p --> sigma* and 2p --> nl resonances were analyzed and the evolution of the resonant Auger to the normal Auger decay distorted by postcollision interaction was examined. We find that valence photoionization channels do not resonate strongly at the photon energies of the core-to-Rydberg excitation, in contrast to the strongly resonating ones observed in the HCl molecule. Auger decay spectra of the 2p (-1)sigma* resonances showed no evidence of atomic transitions in Cl*, also in contrast to HCl. In addition. angular distribution of the photoelectron and Auger-electron lines was derived. C1 Western Michigan Univ, Dept Phys, Kalamazoo, MI 49008 USA. Max Born Inst, D-12489 Berlin, Germany. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. Univ Paris 11, Lab Spect Atom & Ion, Orsay, France. RP Nayandin, O (reprint author), Western Michigan Univ, Dept Phys, Kalamazoo, MI 49008 USA. RI Bozek, John/E-4689-2010; Langer, Burkhard/A-6504-2013; Bozek, John/E-9260-2010; Canton, Sophie/A-8432-2016 OI Bozek, John/0000-0001-7486-7238; NR 25 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 JUN PY 2001 VL 63 IS 6 AR 062719 DI 10.1103/PhysRevA.63.062719 PG 6 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA 439TZ UT WOS:000169134800050 ER PT J AU Snell, G Martins, M Kukk, E Cheng, WT Berrah, N AF Snell, G Martins, M Kukk, E Cheng, WT Berrah, N TI High-resolution electron spectroscopy of a strongly correlated system: Atomic barium SO PHYSICAL REVIEW A LA English DT Article ID PHOTOIONIZATION CROSS-SECTION; PHOTOELECTRON-SPECTROSCOPY; AUGER-ELECTRON; 4D THRESHOLD; BA; SPECTRA; PHOTOABSORPTION; EXCITATION; RESONANCES; STATE AB High-resolution 4d and 5p photoelectron spectra of free barium atoms were measured using narrow-bandwidth synchrotron radiation of 131.2 eV photon energy. These measurements were necessary to disentangle the complex structure of the electron spectra. We also performed a Hartree-Fock calculation with relativistic corrections. A very good agreement between theory and experiment was found, which allowed the assignment of all but the weakest lines, in addition to pointing out the significant contribution of configuration interaction and shake processes. C1 Western Michigan Univ, Dept Phys, Kalamazoo, MI 49008 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. Free Univ Berlin, Inst Expt Phys, D-14195 Berlin, Germany. Natl Cent Univ, Dept Phys, Chungli 32054, Taiwan. RP Snell, G (reprint author), Western Michigan Univ, Dept Phys, Kalamazoo, MI 49008 USA. OI Martins, Michael/0000-0002-1228-5029 NR 27 TC 16 Z9 16 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1050-2947 J9 PHYS REV A JI Phys. Rev. A PD JUN PY 2001 VL 63 IS 6 AR 062715 DI 10.1103/PhysRevA.63.062715 PG 7 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA 439TZ UT WOS:000169134800046 ER PT J AU Abrikosov, AA Buzdin, AI AF Abrikosov, AA Buzdin, AI TI Influence of the nonuniform superconductivity on the upper critical field in the extended saddle-point model SO PHYSICAL REVIEW B LA English DT Article ID TEMPERATURE AB The upper critical field is calculated in the framework of the extended saddle-point model, taking into account the formation of a nonuniform superconducting state. The temperature dependence of the upper critical field is characterized by a positive curvature at all temperatures. This peculiar behavior may be of some relevance to the experimental data on low-dimensional superconductors and overdoped Tl2Ba2CuO2 single crystals. C1 Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. Univ Bordeaux 1, Ctr Phys Theor & Modelisat Bordeaux, F-33405 Talence, France. RP Abrikosov, AA (reprint author), Argonne Natl Lab, Div Mat Sci, 9700 S Cass Ave, Argonne, IL 60439 USA. RI Buzdin, Alexander/I-6038-2013 NR 11 TC 2 Z9 2 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 JUN 1 PY 2001 VL 63 IS 22 AR 224506 DI 10.1103/PhysRevB.63.224506 PG 4 WC Physics, Condensed Matter SC Physics GA 442KD UT WOS:000169283000076 ER PT J AU Alchagirov, AB Perdew, JP Boettger, JC Albers, RC Fiolhais, C AF Alchagirov, AB Perdew, JP Boettger, JC Albers, RC Fiolhais, C TI Energy and pressure versus volume: Equations of state motivated by the stabilized jellium model SO PHYSICAL REVIEW B LA English DT Article ID STRUCTURAL PHASE-STABILITY; GENERALIZED GRADIENT APPROXIMATION; DENSITY-FUNCTIONAL APPROXIMATIONS; LIQUID-DROP MODEL; SIMPLE METALS; IDEAL METALS; UNIVERSAL EQUATION; SOLIDS; SURFACE; HARDNESS AB Explicit functions are widely used to interpolate, extrapolate, and differentiate theoretical or experimental data on the equation of state (EOS) of a solid. We present two EOS functions which are theoretically motivated. The simplest realistic model for a simple metal, the stabilized jellium (SJ) or structureless pseudopotential model, is the paradigm for our SJEOS. A simple metal with exponentially overlapped ion cores is the paradigm for an augmented version (ASJEOS) of the SJEOS. For the three solids tested (Al, Li, Mo), the ASJEOS matches all-electron calculations better than prior equations of state. Like most of the prior EOS's, the ASJEOS predicts pressure P as a function of compressed volume v from only a few equilibrium inputs: the volume v(o), the bulk modulus B-o, and its pressure derivative B-1. Under expansion, the cohesive energy serves as another input. A further advantage of the new equation of state is that these equilibrium properties other than vo may be found by linear fitting methods. The SJEOS can be used to correct B-o and the EOS found from an approximate density functional, if the corresponding error in v(o) is known. We also (a) estimate the typically small contribution of phonon zero-point vibration to the EOS, ib) find that the physical hardness By does not maximize at equilibrium, and (c) show that the "ideal metal'' of Shore and Rose is the zero-valence limit of stabilized jellium. C1 Tulane Univ, Dept Phys, New Orleans, LA 70118 USA. Tulane Univ, Quantum Theory Grp, New Orleans, LA 70118 USA. Univ Calif Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. Univ Coimbra, Ctr Computat Phys, P-3000 Coimbra, Portugal. RP Alchagirov, AB (reprint author), Tulane Univ, Dept Phys, New Orleans, LA 70118 USA. NR 79 TC 84 Z9 85 U1 0 U2 12 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 EI 1550-235X J9 PHYS REV B JI Phys. Rev. B PD JUN 1 PY 2001 VL 63 IS 22 AR 224115 DI 10.1103/PhysRevB.63.224115 PG 16 WC Physics, Condensed Matter SC Physics GA 442KD UT WOS:000169283000031 ER PT J AU Booth, CH Sarrao, JL Hundley, MF Cornelius, AL Kwei, GH Bianchi, A Fisk, Z Lawrence, JM AF Booth, CH Sarrao, JL Hundley, MF Cornelius, AL Kwei, GH Bianchi, A Fisk, Z Lawrence, JM TI Local and average crystal structure and displacements of (LaB6)-B-11 and EuB6 as a function of temperature SO PHYSICAL REVIEW B LA English DT Article ID X-RAY-DIFFRACTION; SINGLE-CRYSTAL; MAGNETIC ORDER; SCATTERING; SPECTRA; XAFS AB Measurements of both the average crystal structure from Rietveld refinement of neutron powder diffraction data and the local structure from La L-III-edge x-ray-absorption fine structure (XAFS) are presented for a (LaB6)-B-11 sample as a function of temperature (similar to 10-320 K). These data are compared to XAFS results on a EuB6 sample. The single-site La and B positional distribution widths and the La-B and La-La bond length distribution widths and their temperature dependence are compared. This comparison allows an estimate of the La and B site displacements, and we find that these sublattices are only slightly correlated with each other. Moreover, while the temperature dependence of the displacement parameters of the average sites obtained from diffraction fit an Einstein model well, the temperature dependence of the La-B bond length distribution width requires at least two vibrational frequencies, corresponding to the La and B frequencies of the individual sites. XAFS data on EuB6 indicate that the situation is the same in the Eu compound. In addition, comparisons between data taken below and above the ferromagnetic transition temperature for EuB6 place stringent limits on the lattice involvement in the associated metal-insulator transition and the ensuing large magnetoresistance effect. This lack of lattice involvement in the magnetoresistance transition is in sharp contrast to the strong lattice involvement observed in the colossal magnetoresistance lanthanum manganese perovskites. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Div Chem Sci, Berkeley, CA 94720 USA. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Univ Nevada, Dept Phys, Las Vegas, NV 89154 USA. Florida State Univ, Dept Phys, Tallahassee, FL 32306 USA. Florida State Univ, Natl High Magnet Field Lab, Tallahassee, FL 32306 USA. Univ Calif Irvine, Dept Phys, Irvine, CA 92697 USA. RP Booth, CH (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Div Chem Sci, Berkeley, CA 94720 USA. EM chbooth@lbl.gov RI Cornelius, Andrew/A-9837-2008; Booth, Corwin/A-7877-2008; Bianchi, Andrea/E-9779-2010 OI Bianchi, Andrea/0000-0001-9340-6971 NR 28 TC 21 Z9 21 U1 1 U2 9 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 JUN 1 PY 2001 VL 63 IS 22 AR 224302 DI 10.1103/PhysRevB.63.224302 PG 8 WC Physics, Condensed Matter SC Physics GA 442KD UT WOS:000169283000041 ER PT J AU Bridges, F Booth, CH Anderson, M Kwei, GH Neumeier, JJ Snyder, J Mitchell, J Gardner, JS Brosha, E AF Bridges, F Booth, CH Anderson, M Kwei, GH Neumeier, JJ Snyder, J Mitchell, J Gardner, JS Brosha, E TI Mn K-edge XANES studies of La(1-x)A(x)MnO(3) systems (A = Ca, Ba, Pb) SO PHYSICAL REVIEW B LA English DT Article ID X-RAY-ABSORPTION; FERROMAGNETIC KONDO MODEL; COLOSSAL-MAGNETORESISTANCE; ELECTRONIC-STRUCTURE; LOCAL-STRUCTURE; LA1-XCAXMNO3 SYSTEM; PEROVSKITE OXIDES; PHASE-DIAGRAM; THIN-FILMS; T-C AB We present Mn K-edge x-ray absorption near-edge structure (XANES) data for a number of manganite systems as a function of temperature. The 1s absorption edge for the Ca-substituted samples is very sharp, almost featureless, and shifts uniformly upwards with increasing Ca content. The interpretation of this result is controversial because the lack of structure appears difficult to reconcile with a mixture of Mn+3 and Mn+4 ions or with several different Mn-O bond lengths at high T. We propose a possible solution in terms of covalency and considerable overlap of the Mn p states (mostly Mn 4p). The manganite preedge structure is quite similar to that for a large number of other Mn compounds, with two or three small peaks that are ascribed to 1s-3d weakly allowed dipole transitions plus possibly a small quadrupole component. The weak dipole transitions are explained as arising from a hybridization of the Mn 4p stale of the excited atom with an odd symmetry combination of Mn 3d states on adjacent Mn atoms. The first preedge peak A(1) has a small shift to higher energy with increasing valence while the next peak A(2) is nearly independent of dopant concentration at 300 K. However, for the colossal magnetoresistance (CMR) samples the A(2) preedge peak shifts to a lower energy below the ferromagnetic transition temperature T-c, resulting in a decrease in the A(2)-A(1) splitting by similar to 0.4 eV. This indicates a change in the higher-energy 3d bands, most likely the minority spin e(g) , plus some change in covalency. In addition, the amplitudes are temperature dependent for the CMR materials, with the change in A(1), A(2) correlated with the change in sample magnetization. For the charge ordered (CO) sample, the analysis suggests that the change in the preedge is produced by a distortion that increases below T-CO. We discuss these results in terms of some of the theoretical models that have been proposed and other recent XANES studies. C1 Univ Calif Santa Cruz, Dept Phys, Santa Cruz, CA 95064 USA. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Florida Atlantic Univ, Dept Phys, Boca Raton, FL 33431 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Argonne Natl Lab, Argonne, IL 60439 USA. RP Bridges, F (reprint author), Univ Calif Santa Cruz, Dept Phys, Santa Cruz, CA 95064 USA. RI Gardner, Jason/A-1532-2013; Booth, Corwin/A-7877-2008 NR 56 TC 77 Z9 77 U1 2 U2 18 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 JUN 1 PY 2001 VL 63 IS 21 AR 214405 DI 10.1103/PhysRevB.63.214405 PG 14 WC Physics, Condensed Matter SC Physics GA 438NV UT WOS:000169060700042 ER PT J AU Bud'ko, SL Petrovic, C Lapertot, G Cunningham, CE Canfield, PC Jung, MH Lacerda, AH AF Bud'ko, SL Petrovic, C Lapertot, G Cunningham, CE Canfield, PC Jung, MH Lacerda, AH TI Magnetoresistivity and H (c2)(T) in MgB2 SO PHYSICAL REVIEW B LA English DT Article ID UPPER CRITICAL-FIELD; MAGNETIC-PROPERTIES; TRANSPORT; LUNI2B2C AB Detailed magnetotransport data on dense wires of MgB2 are reported for applied magnetic fields up to 18 T. The temperature and field dependencies of the electrical resistivity are consistent with MgB2 behaving like a simple metal and following a generalized form of Kohler's rule. In addition, given the generally higher-T-c values and narrower resistive transition widths associated with MgB2 synthesized in this manner, combined with applied magnetic fields of up to 18 TI an accurate and complete H-c2(T) curve could be determined. This curve agrees well with curves determined from lower field measurements on sintered pellets and wires of MgB2. H-c2(T) is linear in T over a wide range of temperature (7 K less than or equal toT less than or equal to 32 K) and has an upward curvature for T close to T-c. These features are similar to other high kappa, clean limit, boron-bearing intermetallics: YNi2B2C and LuNi2B2C. C1 Iowa State Univ Sci & Technol, US Dept Energy, Ames Lab, Ames, IA 50011 USA. Iowa State Univ Sci & Technol, Dept Phys & Astron, Ames, IA 50011 USA. Univ Calif Los Alamos Natl Lab, Natl High Magnet Field Lab, Pulse Facil, Los Alamos, NM 87545 USA. New Mexico State Univ, Dept Phys, Las Cruces, NM 88003 USA. RP Lapertot, G (reprint author), Iowa State Univ Sci & Technol, US Dept Energy, Ames Lab, Ames, IA 50011 USA. RI LAPERTOT, Gerard/B-3354-2008; Petrovic, Cedomir/A-8789-2009; Canfield, Paul/H-2698-2014 OI Petrovic, Cedomir/0000-0001-6063-1881; NR 16 TC 115 Z9 117 U1 1 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 JUN 1 PY 2001 VL 63 IS 22 AR 220503 DI 10.1103/PhysRevB.63.220503 PG 3 WC Physics, Condensed Matter SC Physics GA 442KD UT WOS:000169283000010 ER PT J AU Eschrig, M Ferrer, J Fogelstrom, M AF Eschrig, M Ferrer, J Fogelstrom, M TI Mixed-parity superconductivity in Sr2RuO4 SO PHYSICAL REVIEW B LA English DT Article ID SPIN-TRIPLET SUPERCONDUCTIVITY; LAYERED PEROVSKITE; ORDER-PARAMETER; FERMI-SURFACE; SYMMETRY; STATES; FLUCTUATIONS; HEAT AB We show that in Sr2RuO4 the Fermi surface geometry as inferred from angle resolved photoemission experiments has important implications for a pairing interaction dominated by incommensurate, strongly anisotropic, spin fluctuations. For a spin fluctuation spectrum consistent with inelastic neutron-scattering experiments the system is close to an accidental degeneracy between even parity spin singlet and odd parity spin triplet channels. This opens the possibility of a mixed parity order parameter state in Sr2RuO4 We determine the stable and metastable order parameter phases at low-temperatures and discuss especially phases with order parameter nodes. C1 Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. Univ Oviedo, Dept Fis, Fac Ciencias, E-33007 Oviedo, Spain. Chalmers Univ Technol, Inst Theoret Phys, S-41296 Gothenburg, Sweden. Univ Gothenburg, S-41296 Gothenburg, Sweden. RP Eschrig, M (reprint author), Argonne Natl Lab, Div Mat Sci, 9700 S Cass Ave, Argonne, IL 60439 USA. RI Eschrig, Matthias/B-4786-2009; Fogelstrom, Mikael/E-3368-2010; Ferrer, Jaime/G-3888-2011; Nimori, Shigeki/H-2643-2011; OI Fogelstrom, Mikael/0000-0003-3441-2559; Ferrer, Jaime/0000-0002-4067-2325; Eschrig, Matthias/0000-0003-4954-5549 NR 27 TC 13 Z9 13 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 JUN 1 PY 2001 VL 63 IS 22 AR 220509 DI 10.1103/PhysRevB.63.220509 PG 4 WC Physics, Condensed Matter SC Physics GA 442KD UT WOS:000169283000016 ER PT J AU Gao, F Weber, WJ Jiang, W AF Gao, F Weber, WJ Jiang, W TI Primary damage states produced by Si and Au recoils in SiC: A molecular dynamics and experimental investigation SO PHYSICAL REVIEW B LA English DT Article ID IRRADIATION-INDUCED AMORPHIZATION; SILICON-CARBIDE; INDUCED CRYSTALLINE; DEFECT PRODUCTION; DISPLACEMENT CASCADES; AMORPHOUS TRANSITION; SINGLE-CRYSTALS; CERAMICS AB Molecular dynamics (MD) simulations, experimental studies, and a theoretical model have been combined in an investigation of the disordering and amorphization processes in SiC irradiated with Si and Au ions. In MD simulations, large disordered domains, consisting of interstitials and antisite defects, are created in the cascades produced by Au primary knock-on atoms (PKAs); whereas Si PKAs generate only small interstitial clusters, with most defects being single interstitials and vacancies distributed over a large region. The data for a cluster spectrum obtained from MD simulations have been used to calculate the relative cross sections for in-cascade amorphization (or clustering) sigma (DI) and in-cascade defect-stimulated amorphization sigma (DS). The ratio of these-cross sections, sigma (DS)/sigma (DI), for Si and Au is in excellent agreement with those derived from the experimental data based on a fit of the direct-impact-defect-stimulated model. This suggests that the observed higher disordering rate and the residual disorder after thermal annealing at 300 K for irradiation with Au2+ are associated with a higher probability for in-cascade amorphization or large disordered cluster formation. The observed different behavior for the accumulation and recovery of disorder in SiC irradiated by Si+ and Au2+ is qualitatively consistent with the present MD simulations and the direct-impact-defect-stimulated model. C1 Pacific NW Natl Lab, Richland, WA 99352 USA. RP Gao, F (reprint author), Pacific NW Natl Lab, MSIN K8-93,POB 999, Richland, WA 99352 USA. RI Weber, William/A-4177-2008; Gao, Fei/H-3045-2012 OI Weber, William/0000-0002-9017-7365; NR 28 TC 28 Z9 29 U1 1 U2 13 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 JUN 1 PY 2001 VL 63 IS 21 AR 214106 DI 10.1103/PhysRevB.63.214106 PG 6 WC Physics, Condensed Matter SC Physics GA 438NV UT WOS:000169060700031 ER PT J AU Gehring, PM Park, SE Shirane, G AF Gehring, PM Park, SE Shirane, G TI Dynamical effects of the nanometer-sized polarized domains in Pb(Zn1/3Nb2/3)O-3 SO PHYSICAL REVIEW B LA English DT Article ID RELAXOR FERROELECTRIC PBMG1/3NB2/3O3; X-RAY-SCATTERING; SINGLE-CRYSTALS; NEUTRON-SCATTERING; PHASE-TRANSITIONS; BEHAVIOR AB Results from an extensive single-crystal neutron-scattering study of the relaxer ferroelectric Pb(Zn1/3Nb2/3)O-3 (PZN) in the cubic phase reveal an anomalous ridge of inelastic scattering that extends vertically from the transverse acoustic (TA) branch near 4 meV to the transverse optic (TO) branch near 9 meV at q similar to0.2 Angstrom (-1). No zone center optic mode was found. Similar results were recently reported in a sample of PZN doped with 8% PbTiO3. We are able to describe the dynamics of this unusual feature using a simple coupled-mode model that assumes the optic mode linewidth Gamma (1)(q) increases sharply near q = 0.2 Angstrom (-1) as q -->0. The dramatic increase in Gamma (1)(q) is believed to occur when the wavelength of the optic mode becomes comparable to the size of small polarized nanoregions (PNR) that develop in the cubic phase of PZN, far above T-c=410 K. The consequence is that long-wavelength optic modes cannot propagate and become overdamped. Hence the q at which the anomalous scattering is peaked provides an important measure of the size of the PNR. Below T-c, the intensity of this scattering diminishes. At lowest temperatures (similar to 30 K) the feature is absent, and we observe the recovery of a zone center transverse optic mode near 10.5 meV. C1 Natl Inst Stand & Technol, NIST Ctr Neutron Res, Gaithersburg, MD 20899 USA. Penn State Univ, Mat Res Lab, University Pk, PA 16802 USA. Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. RP Park, SE (reprint author), Natl Inst Stand & Technol, NIST Ctr Neutron Res, Gaithersburg, MD 20899 USA. OI Gehring, Peter/0000-0002-9236-2046 NR 21 TC 64 Z9 65 U1 1 U2 12 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 EI 1550-235X J9 PHYS REV B JI Phys. Rev. B PD JUN 1 PY 2001 VL 63 IS 22 AR 224109 DI 10.1103/PhysRevB.63.224109 PG 7 WC Physics, Condensed Matter SC Physics GA 442KD UT WOS:000169283000025 ER PT J AU Haffner, S Brammeier, DM Olson, CG Miller, LL Lynch, DW AF Haffner, S Brammeier, DM Olson, CG Miller, LL Lynch, DW TI No well-defined remnant Fermi surface in Sr2CuO2Cl2 SO PHYSICAL REVIEW B LA English DT Article ID ANGLE-RESOLVED PHOTOEMISSION; ELECTRONIC-STRUCTURE; MATRIX ELEMENT; STATES; GAP; BI2SR2CACU2O8+DELTA; SUPERCONDUCTORS; CA2CUO2CL2; PLANES; MODEL AB In angle-resolved photoelectron spectra of the antiferromagnetic insulators Ca2CuO2Cl2 and Sr2CuO2Cl2, a sharp drop of the spectral intensity of the lowest-lying band is observed along a line in k space equivalent to the Fermi surface of the optimally doped high-temperature superconductors. This was interpreted as a signature of the existence of a remnant Fermi surface in the insulating phase of the high-temperature superconductors. In this paper it is shown that the drop of the spectral intensity is not related to the spectral function but is a consequence of the electron-photon matrix element. C1 Iowa State Univ Sci & Technol, Dept Phys & Astron, Ames, IA 50011 USA. Iowa State Univ Sci & Technol, US Dept Energy, Ames Lab, Ames, IA 50011 USA. RP Haffner, S (reprint author), Iowa State Univ Sci & Technol, Dept Phys & Astron, Ames, IA 50011 USA. NR 26 TC 5 Z9 6 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 JUN 1 PY 2001 VL 63 IS 21 AR 212501 DI 10.1103/PhysRevB.63.212501 PG 4 WC Physics, Condensed Matter SC Physics GA 438NV UT WOS:000169060700017 ER PT J AU Jorgensen, JD Hinks, DG Short, S AF Jorgensen, JD Hinks, DG Short, S TI Lattice properties of MgB2 versus temperature and pressure SO PHYSICAL REVIEW B LA English DT Article AB We have determined the structural properties of the superconducting compound MgB2 as a function of temperature from 11 to 297 K and as a function of hydrostatic pressure up to 0.62 GPa using neutron powder diffraction. This compound, when compared to other diborides with the same structure, is characterized by unusually large anisotropies of both the thermal expansion and compressibility, with the c-axis responses being substantially larger. We speculate that the comparatively weaker metal-boron bonding in MgB2 manifested by these lattice responses, is important for establishing the structural features that give rise to high-T-c superconductivity in this structure type. C1 Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. RP Jorgensen, JD (reprint author), Argonne Natl Lab, Div Mat Sci, 9700 S Cass Ave, Argonne, IL 60439 USA. NR 24 TC 131 Z9 131 U1 4 U2 19 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 JUN 1 PY 2001 VL 63 IS 22 AR 224522 DI 10.1103/PhysRevB.63.224522 PG 5 WC Physics, Condensed Matter SC Physics GA 442KD UT WOS:000169283000092 ER PT J AU Katsnelson, MI Dobrovitski, VV Harmon, BN AF Katsnelson, MI Dobrovitski, VV Harmon, BN TI Neel state of an antiferromagnet as a result of a local measurement in the distributed quantum system SO PHYSICAL REVIEW B LA English DT Article ID MAGNETIC-RESONANCE; ENVIRONMENT AB Single-site measurement in a distributed macroscopic antiferromagnet on a bipartite lattice is considered; we show that it can create antiferromagnetic sublattices at macroscopic scale. We demonstrate that the result of measurement depends on the symmetry of the ground state: for the easy-axis case the Neel state is formed, while for the easy-plane case unusual "fan" sublattices appear with unbroken rotational symmetry, and a decoherence wave is generated. For the latter case, a macroscopically large number of measurements is needed to pin down the orientation of the sublattices. We note that the type of the final state and the appearance of the decoherence wave are governed by the degree of entanglement of spins in the system. C1 Iowa State Univ Sci & Technol, Dept Phys & Astron, Ames Lab, Ames, IA 50011 USA. Russian Acad Sci, Inst Met Phys, Sverdlovsk 620219, Russia. RP Katsnelson, MI (reprint author), Iowa State Univ Sci & Technol, Dept Phys & Astron, Ames Lab, Ames, IA 50011 USA. RI Katsnelson, Mikhail/D-4359-2012 NR 21 TC 6 Z9 6 U1 0 U2 1 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 EI 1550-235X J9 PHYS REV B JI Phys. Rev. B PD JUN 1 PY 2001 VL 63 IS 21 AR 212404 DI 10.1103/PhysRevB.63.212404 PG 4 WC Physics, Condensed Matter SC Physics GA 438NV UT WOS:000169060700011 ER PT J AU Lashley, JC Lang, BE Boerio-Goates, J Woodfield, VG Schmiedeshoff, GM Gay, EC McPheeters, CC Thoma, DJ Hults, WL Cooley, JC Hanrahan, RJ Smith, JL AF Lashley, JC Lang, BE Boerio-Goates, J Woodfield, VG Schmiedeshoff, GM Gay, EC McPheeters, CC Thoma, DJ Hults, WL Cooley, JC Hanrahan, RJ Smith, JL TI Low-temperature specific heat and critical magnetic field of alpha-uranium single crystals SO PHYSICAL REVIEW B LA English DT Article ID CHARGE-DENSITY-WAVE AB The current work reports on the specific heat and the electrical resistivity of alpha -uranium at cryogenic temperatures. Measurements were made on alpha -uranium single crystals that have some unexpected mechanical properties. Despite the fact that alpha -uranium normally work hardens and often fails in a brittle manner, these crystals bend easily. Presumably, the combination of flexibility and strength comes from twinning in response to stress, and these twins can run freely during deformation. Because grain boundaries are not present, we anticipated that the characteristics of the charge density wave (CDW) might be more prominent in these crystals. For these reasons, the specific heat was measured from T approximate to0.5 to 110 K, using semiadiabatic calorimetry in zero field, and the electrical resistivity was measured from T approximate to0.1 to 0.50 K, in magnetic fields up to 80 mT using a standard four-probe ar technique. An abrupt resistance drop typical of a superconducting transition was observed as the temperature fell below 0.78 K, a temperature at which the resistance fell to 90% from its original value. A residual resistivity ratio RRR approximate to 115 was measured from the low-temperature resistivity data. In addition, three phase transitions were clearly seen in the specific-heat data, located at T= 23, 36, and 42 K. These transitions are consistent with the alpha (3), alpha (2), and alpha (1) CDW structures that have been previously observed in uranium metal. Analysis of the specific-heat data give an electronic specific heat (gamma) = 9.13 mJ K-2 mol(-1) and a low-temperature limiting Debye temperature (Theta (D))= 256 K (+/- 0.25 K). The highest calorimetric value measured previously was 218 K. Our value of 256 K is in favorable agreement with that previously obtained from elastic constants 250 K (+/-2 K). The agreement between calorimetric and elastic OD values, ductility at room temperature, and a RRR that is three times larger than previously reported values highlight the properties of these alpha -uranium single crystals. C1 Brigham Young Univ, Dept Chem & Biochem, Provo, UT 84602 USA. Univ Calif Los Alamos Natl Lab, Div Mat Sci & Technol, Los Alamos, NM 87545 USA. Occidental Coll, Dept Phys, Los Angeles, CA 90041 USA. Argonne Natl Lab, CMT Div, Argonne, IL 60439 USA. RP Lashley, JC (reprint author), Brigham Young Univ, Dept Chem & Biochem, Provo, UT 84602 USA. RI Cooley, Jason/E-4163-2013 NR 21 TC 37 Z9 37 U1 0 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 JUN 1 PY 2001 VL 63 IS 22 AR 224510 DI 10.1103/PhysRevB.63.224510 PG 7 WC Physics, Condensed Matter SC Physics GA 442KD UT WOS:000169283000080 ER PT J AU Lindbaum, A Heathman, S Litfin, K Meresse, Y Haire, RG Le Bihan, T Libotte, H AF Lindbaum, A Heathman, S Litfin, K Meresse, Y Haire, RG Le Bihan, T Libotte, H TI High-pressure studies of americium metal: Insights into its position in the actinide series SO PHYSICAL REVIEW B LA English DT Article ID POWDER DIFFRACTION; ATOMIC VOLUMES; PHASE; SUPERCONDUCTIVITY; DELOCALIZATION AB Americium metal occupies a pivotal position in the actinide series, displaying localized f electron bonding while the four preceding members are recognized for their itinerant f electron behavior. Important insights into the nature of americium's f electrons with regard to metallic bonding and the relationship to that in the gamma form of plutonium have been acquired through studies of americium up to 100 GPa. Synchrotron radiation and other experimental advances were used to obtain data of high qualify and resolution to resolve fully the high-pressure crystal structures of americium metal. We have resolved controversial findings reported earlier for americium in the 10-30 GPa region, and also addressed the significant differences that exist between the reported theoretical and experimental volume collapses. In this work we found that the normal pressure double hexagonal close packed (P6(3)/mmc) structure transforms at 6.1 GPa to a face centered cubic (Fm3m) phase. At 10.0 GPa, the latter converts to a face centered orthorhombic (Fddd) structure, which with additional pressure undergoes a further transformation to form a primitive orthorhombic structure (Pnma) at 16 GPa. The Pnma structure is stable up to at least 100 GPa, the maximum pressure reported here. By identifying correctly the structural forms of the Am III and IV phases, the mechanisms for sequential conversion of the structures with pressure have been established. A critical aspect of these data is that the Am III phase is now believed to reflect the first involvement of americium's f electrons in the metallic bonding: additional involvement occurs in the,en IV phase. This work provides important insights for understanding the pivotal position of americium in the actinide series and should bring about the convergence of experimental and theoretical views regarding its pressure behavior. C1 European Commiss, Inst Transuranium Elements, Joint Res Ctr, D-76125 Karlsruhe, Germany. Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. European Synchrotron Radiat Facil, F-38043 Grenoble, France. RP Lindbaum, A (reprint author), Vienna Tech Univ, Inst Expt Phys, Wiedner Hauptstr 8-10-131, A-1040 Vienna, Austria. EM lindbaum@xphys.tuwien.ac.at RI LE BIHAN, Tristan/I-5063-2013 NR 41 TC 71 Z9 71 U1 1 U2 11 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 EI 1550-235X J9 PHYS REV B JI Phys. Rev. B PD JUN 1 PY 2001 VL 63 IS 21 AR 214101 DI 10.1103/PhysRevB.63.214101 PG 10 WC Physics, Condensed Matter SC Physics GA 438NV UT WOS:000169060700026 ER PT J AU Mesot, J Randeria, M Norman, MR Kaminski, A Fretwell, HM Campuzano, JC Ding, H Takeuchi, T Sato, T Yokoya, T Takahashi, T Chong, I Terashima, T Takano, M Mochiku, T Kadowaki, K AF Mesot, J Randeria, M Norman, MR Kaminski, A Fretwell, HM Campuzano, JC Ding, H Takeuchi, T Sato, T Yokoya, T Takahashi, T Chong, I Terashima, T Takano, M Mochiku, T Kadowaki, K TI Determination of the Fermi surface in high-T-c superconductors by angle-resolved photoemission spectroscopy SO PHYSICAL REVIEW B LA English DT Article ID ELECTRONIC-STRUCTURE; BI2SR2CACU2O8+DELTA; STATE; ARPES; DISPERSION; ENERGY; BISCO; BANDS AB We study the normal-state electronic excitations probed by angle-resolved photoemission spectroscopy (ARPES) in Bi1.6Pb0.4Sr2CuO6 (Bi2201) and Bi2Sr2CaCu2O8 divided by delta (Bi2212). Our main goal is to establish explicit criteria for determining the Fermi surface from ARPES data on strongly interacting systems where sharply defined quasiparticles do not exist and the dispersion is very weak in parts of the Brillouin zone. Additional complications arise from strong matrix element variations within the zone. We present detailed results as a function of incident photon energy, and show simple experimental tests to distinguish between an intensity drop due to matrix element effects and spectral weight loss due to a Fermi crossing. We reiterate the use of polarization selection rules in disentangling the effect of umklapps due to the BiO superlattice in Bi2212. We conclude that, despite all the complications, the Fermi surface can be determined unambiguously; it is a single large hole barrel centered about (pi,pi) in both materials. C1 Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. Univ Illinois, Dept Phys, Chicago, IL 60607 USA. Tata Inst Fundamental Res, Mumbai 400005, India. Boston Coll, Dept Phys, Chestnut Hill, MA 02467 USA. Nagoya Univ, Dept Crytalline Mat Sci, Nagoya, Aichi 46401, Japan. Tohoku Univ, Dept Phys, Sendai, Miyagi, Japan. Kyoto Univ, Chem Res Inst, Kyoto 6110011, Japan. Natl Res Inst Met, Tsukuba, Ibaraki 305, Japan. RP Mesot, J (reprint author), Swiss Fed Inst Technol, Neutron Scattering Lab, CH-5232 Villigen, Switzerland. RI Takahashi, Takashi/E-5080-2010; Sato, Takafumi/E-5094-2010; Tohoku, Arpes/A-4890-2010; Norman, Michael/C-3644-2013; YOKOYA, Takayoshi/B-1478-2011 NR 34 TC 59 Z9 59 U1 2 U2 20 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 JUN 1 PY 2001 VL 63 IS 22 AR 224516 DI 10.1103/PhysRevB.63.224516 PG 14 WC Physics, Condensed Matter SC Physics GA 442KD UT WOS:000169283000086 ER PT J AU Mishin, Y Mehl, MJ Papaconstantopoulos, DA Voter, AF Kress, JD AF Mishin, Y Mehl, MJ Papaconstantopoulos, DA Voter, AF Kress, JD TI Structural stability and lattice defects in copper: Ab initio, tight-binding, and embedded-atom calculations SO PHYSICAL REVIEW B LA English DT Article ID PLANE-WAVE-BASIS; TOTAL-ENERGY CALCULATIONS; FCC METALS; INTERATOMIC POTENTIALS; NOBLE-METALS; TRANSITION-METALS; ELASTIC-CONSTANTS; GRAIN-BOUNDARIES; EXTENDED DEFECTS; BCC STRUCTURE AB We evaluate the ability of the embedded-atom method (EAM) potentials and the tight-binding (TB) method to predict reliably energies and stability of nonequilibrium structures by taking Cu as a model material. Two EAM potentials are used here. One is constructed in this work by using more fitting parameters than usual and including ab initio energies in the fitting database. The other potential was constructed previously using a traditional scheme. Excellent agreement is observed between ab initio, TB, and EAM results for the energies and stability of several nonequilibrium structures of Cu, as well as for energies along deformation paths between different structures. We conclude that not only TB calculations but also EAM potentials can be suitable for simulations in which correct energies and stability of different atomic configurations are essential, at least for Cu. The bcc, simple cubic, and diamond structures of Cu were identified as elastically unstable, while some other structures (e.g., hcp and 9R) are metastable. As an application of this analysis, nonequilibrium structures of epitaxial Cu films on (001)-oriented fcc or bcc substrates are evaluated using a simple model and atomistic simulations with an EAM potential. In agreement with experimental data, the structure of the film can be either deformed fee or deformed hcp. The bcc structure cannot be stabilized by epitaxial constraints. C1 George Mason Univ, Sch Computat Sci, Fairfax, VA 22030 USA. USN, Res Lab, Ctr Computat Mat Sci, Washington, DC 20375 USA. Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. RP George Mason Univ, Sch Computat Sci, Fairfax, VA 22030 USA. RI Mishin, Yuri/P-2020-2015; Mehl, Michael/H-8814-2016; OI Voter, Arthur/0000-0001-9788-7194 NR 87 TC 931 Z9 961 U1 19 U2 165 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 JUN 1 PY 2001 VL 63 IS 22 AR 224106 DI 10.1103/PhysRevB.63.224106 PG 16 WC Physics, Condensed Matter SC Physics GA 442KD UT WOS:000169283000022 ER PT J AU Morr, DK AF Morr, DK TI Spin-lattice relaxation in the mixed state of the high-T-c cuprates: Electronic spin-flip scattering versus spin fluctuations SO PHYSICAL REVIEW B LA English DT Article ID VORTEX LATTICE; SUPERCONDUCTORS; YBA2CU3O7-DELTA; NMR AB Recent experimental and theoretical studies have established that the spin-lattice relaxation rate 1/T-1 measured in nuclear magnetic resonance (NMR) experiments is a site-sensitive probe for-the electronic spectrum in the mixed state of the high-T-c cuprates. While some groups suggested that 1/T-1 is solely determined by spin-flip scattering of BCS-like electrons, other groups stressed the importance of antiferromagnetic spin-fluctuations. We show that these two relaxation mechanisms give rise to a qualitatively different temperature and frequency dependence of O-17 1/T-1. A comparison of our results with the experimental O-17 1/T-1 data provides support for a relaxation mechanism dominated by antiferromagnetic spin fluctuations. C1 Univ Calif Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. RP Morr, DK (reprint author), Univ Calif Los Alamos Natl Lab, Div Theoret, MS B262, Los Alamos, NM 87545 USA. NR 16 TC 13 Z9 13 U1 0 U2 0 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 EI 1550-235X J9 PHYS REV B JI Phys. Rev. B PD JUN 1 PY 2001 VL 63 IS 21 AR 214509 DI 10.1103/PhysRevB.63.214509 PG 6 WC Physics, Condensed Matter SC Physics GA 438NV UT WOS:000169060700068 ER PT J AU Morris, JR Ho, KM AF Morris, JR Ho, KM TI Molecular dynamic simulation of a homogeneous bcc -> hcp transition SO PHYSICAL REVIEW B LA English DT Article ID STRUCTURAL PHASE-TRANSITIONS; GROUP-IV METALS; ZR-NB ALLOYS; PHONON-DISPERSION; BCC PHASE; CENTRAL PEAK; OMEGA-PHASE; ZIRCONIUM; MODEL; SCATTERING AB We have performed molecular dynamic simulations of a martensitic bcc-->hcp transformation in a homogeneous system. The system evolves into three martensitic variants, sharing a common nearest-neighbor vector along a bcc(111) direction, plus an fee region. Nucleation occurs locally, followed by subsequent growth. We monitor the time-dependent scattering S(Q,t) during the transformation, and find anomalous, Brillouin-zone-dependent scattering similar to that observed experimentally in a number of systems above the transformation temperature. This scattering is shown to be related to the elastic strain associated with the transformation and is not directly related to the phonon response. C1 Iowa State Univ, Dept Phys & Astron, Ames Lab, US DOE, Ames, IA 50011 USA. RP Morris, JR (reprint author), Iowa State Univ, Dept Phys & Astron, Ames Lab, US DOE, Ames, IA 50011 USA. EM jrmorris@ameslab.gov RI Morris, J/I-4452-2012 OI Morris, J/0000-0002-8464-9047 NR 32 TC 22 Z9 22 U1 0 U2 12 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 EI 1550-235X J9 PHYS REV B JI Phys. Rev. B PD JUN 1 PY 2001 VL 63 IS 22 AR 224116 DI 10.1103/PhysRevB.63.224116 PG 9 WC Physics, Condensed Matter SC Physics GA 442KD UT WOS:000169283000032 ER PT J AU Qian, Q Tyson, TA Kao, CC Prellier, W Bai, J Biswas, A Greene, RL AF Qian, Q Tyson, TA Kao, CC Prellier, W Bai, J Biswas, A Greene, RL TI Strain-induced local distortions and orbital ordering in Nd0.5Sr0.5MnO3 manganite films SO PHYSICAL REVIEW B LA English DT Article ID LOW-FIELD MAGNETORESISTANCE; THIN-FILMS; MAGNETIC-ANISOTROPY; TRANSITION; LAMNO3; DEPENDENCE; CHARGE; STATE; MN AB We have performed a detailed study of the long-range and local structure of Nd0.5Sr0.5MnO3 films of varying thicknesses. The detailed nature of the in-plane and out-of-plane d spacings as a function of film thickness was determined. Comparisons between the local structure about Mn and the long-range structure were made. We found that Mn coordination asymmetry exists in thin films and that it is related to orbital ordering. The results yield a confirmation of models of manganite systems, which suggests that biaxial strain enhances electron localization. C1 New Jersey Inst Technol, Dept Phys, Newark, NJ 07102 USA. Brookhaven Natl Lab, Upton, NY 11973 USA. Univ Maryland, Ctr Superconduct Res, College Pk, MD 20742 USA. Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Qian, Q (reprint author), New Jersey Inst Technol, Dept Phys, Newark, NJ 07102 USA. RI Bai, Jianming/O-5005-2015 NR 23 TC 22 Z9 22 U1 1 U2 9 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 JUN 1 PY 2001 VL 63 IS 22 AR 224424 DI 10.1103/PhysRevB.63.224424 PG 4 WC Physics, Condensed Matter SC Physics GA 442KD UT WOS:000169283000069 ER PT J AU Rubhausen, M Gozar, A Klein, MV Guptasarma, P Hinks, DG AF Rubhausen, M Gozar, A Klein, MV Guptasarma, P Hinks, DG TI Superconductivity-induced optical changes for energies of 100 Delta in the cuprates SO PHYSICAL REVIEW B LA English DT Article ID SINGLE-CRYSTAL YBA2CU3O7-DELTA; TUNNELING SPECTROSCOPY; RAMAN-SCATTERING; EXCITATIONS; ANISOTROPY; GAP; BI2SR2CACU2O8+DELTA; DEPENDENCE AB We present information on the temperature-dependent changes of the complex pseudodielectric function in the high-T-c superconductor Bi2Sr2CaCu2O8-delta by means of spectroscopic ellipsometry. We reveal the existence of three distinct spectral regions. Below 2 eV, there are changes in the dielectric function associated with the free-carrier response. In slightly underdoped compounds we find at around 3 eV a strong rise of epsilon (2) below the temperature signifying the opening of a pseudogap (T* approximate to 150 K) and an additional enhancement of similar strength below the superconducting transition(T-c=90 K). With overdoping, we find vanishing effects above T-c and a significant decrease in the T-c related effect. This behavior fits to the strong suppression of the antiferromagnetic correlations with increasing doping. C1 Univ Illinois, Dept Phys, Urbana, IL 61801 USA. Univ Hamburg, Inst Angew Phys, D-20355 Hamburg, Germany. Bell Labs, Lucent Technol, Murray Hill, NJ USA. Univ Wisconsin, Dept Phys, Milwaukee, WI 53211 USA. Argonne Natl Lab, MSD, Argonne, IL 60439 USA. RP Rubhausen, M (reprint author), Univ Illinois, Dept Phys, 1110 W Green St, Urbana, IL 61801 USA. NR 24 TC 26 Z9 26 U1 0 U2 1 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 EI 1550-235X J9 PHYS REV B JI Phys. Rev. B PD JUN 1 PY 2001 VL 63 IS 22 AR 224514 DI 10.1103/PhysRevB.63.224514 PG 5 WC Physics, Condensed Matter SC Physics GA 442KD UT WOS:000169283000084 ER PT J AU Rudin, SP Liu, AY Freericks, JK Quandt, A AF Rudin, SP Liu, AY Freericks, JK Quandt, A TI Comparison of structural transformations and superconductivity in compressed sulfur and selenium SO PHYSICAL REVIEW B LA English DT Article ID LINEAR-RESPONSE; ELECTRICAL BEHAVIOR; PHASE-TRANSITIONS; PRESSURE; TELLURIUM; DENSITY; PSEUDOPOTENTIALS; METALS AB Density-functional calculations are presented for high-pressure structural phases of S and Se. The structural phase diagrams, phonon spectra, electron-phonon coupling, and superconducting properties of the isovalent elements are compared. We find that with increasing pressure, Se adopts a sequence of ever more closely packed structures (beta -Po, bcc, fcc), while S favors more open structures (beta -Po, simple cubic, bcc). These differences are shown to be attributable to differences in the S and Se core states. All the compressed phases of S and Se considered are calculated to have weak to moderate electron-phonon coupling strengths consistent with superconducting transition temperatures in the range of 1 to 20 K. Our results compare well with experimental data on the beta -Po --> bcc transition pressure in Se and on the superconducting transition temperature in beta -Po S. Further experiments are suggested to search for the other structural phases predicted at higher pressures and to test theoretical results on the electron-phonon interaction and superconducting properties. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Georgetown Univ, Dept Phys, Washington, DC 20057 USA. RP Rudin, SP (reprint author), Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. RI Freericks, James/D-7502-2011; Liu, Amy/E-2266-2015; OI Liu, Amy/0000-0002-2011-1854; Freericks, James/0000-0002-6232-9165 NR 35 TC 12 Z9 12 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 JUN 1 PY 2001 VL 63 IS 22 AR 224107 DI 10.1103/PhysRevB.63.224107 PG 9 WC Physics, Condensed Matter SC Physics GA 442KD UT WOS:000169283000023 ER PT J AU Salem-Sugui, S Alvarenga, AD Friesen, M Moloni, K Ghivelder, L Veal, B Paulikas, P AF Salem-Sugui, S Alvarenga, AD Friesen, M Moloni, K Ghivelder, L Veal, B Paulikas, P TI Reply to "Comment on 'Temperature dependence of the second magnetization peak in a deoxygenated YBa2Cu3O6.65 single crystal' " SO PHYSICAL REVIEW B LA English DT Editorial Material ID SUPERCONDUCTORS AB Using magnetic hysteresis loops obtained at 3.3 K, together with magnetic relaxation measurements, we demonstrate that the location of the central magnetization peak H' is well resolved, and occurs well below the second peak H-p. C1 UFRJ, Inst Fis, BR-21945970 Rio De Janeiro, Brazil. Ctr Brasileiro Pesquisas Fis, BR-22290180 Rio De Janeiro, Brazil. Univ Wisconsin, Madison, WI 53706 USA. Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. RP Salem-Sugui, S (reprint author), UFRJ, Inst Fis, CP8528, BR-21945970 Rio De Janeiro, Brazil. RI Alvarenga, Ana Paula/M-9790-2014; GHIVELDER, LUIS/L-1820-2015 OI GHIVELDER, LUIS/0000-0002-5667-6531 NR 5 TC 0 Z9 0 U1 0 U2 0 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 EI 1550-235X J9 PHYS REV B JI Phys. Rev. B PD JUN 1 PY 2001 VL 63 IS 21 AR 216502 PG 2 WC Physics, Condensed Matter SC Physics GA 438NV UT WOS:000169060700082 ER PT J AU Sanati, M Saxena, A Lookman, T Albers, RC AF Sanati, M Saxena, A Lookman, T Albers, RC TI Landau free energy for a bcc-hcp reconstructive phase transformation SO PHYSICAL REVIEW B LA English DT Article ID GROUP-IV METALS; INTERPHASE BOUNDARIES; PHONON-DISPERSION; GINZBURG MODEL; BRILLOUIN-ZONE; SPECIAL POINTS; TRANSITIONS; TITANIUM; SYSTEMS; BAND AB We study the bcc-hcp phase transition in Ti and Zr with the use of first-principles calculations. We have determined the complete energy surface from the bcc to hcp structure. The results are used to find an appropriate Landau free energy density for describing this transformation. The proposed Landau free energy density has two relevant order parameters: shear and shuffle. Through first-principles calculations, we show that the bcc structure is unstable with respect to the shuffle of atoms (TA(1) N-point phonon) rather than the shear. Therefore, we reduce the two order parameter Landau free energy to an effective one order parameter (shuffle) potential, which is a reasonable approximation. In general, the effective Landau free energy is a triple-well potential. From the phonon dispersion data and the change in entropy at the transition temperature we find the free energy coefficients for Ti and Zr. C1 Natl Renewable Energy Lab, Golden, CO 80401 USA. Univ Calif Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. RP Sanati, M (reprint author), Natl Renewable Energy Lab, Golden, CO 80401 USA. NR 32 TC 25 Z9 25 U1 1 U2 11 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 EI 1550-235X J9 PHYS REV B JI Phys. Rev. B PD JUN 1 PY 2001 VL 63 IS 22 AR 224114 DI 10.1103/PhysRevB.63.224114 PG 7 WC Physics, Condensed Matter SC Physics GA 442KD UT WOS:000169283000030 ER PT J AU Schmidt, H Zasadzinski, JF Gray, KE Hinks, DG AF Schmidt, H Zasadzinski, JF Gray, KE Hinks, DG TI Energy gap from tunneling and metallic contacts onto MgB2: Possible evidence for a weakened surface layer SO PHYSICAL REVIEW B LA English DT Article ID SUPERCONDUCTORS; STATES AB Point-contact tunnel junctions using a Au tip on sintered MgB2 pellets reveal a sharp superconducting energy gap that is confirmed by subsequent metallic contacts made on the same sample. The peak in the tunneling conductance and the metallic contact conductance follow the BCS form, but the gap values of 4.3 -4.6 meV are less than the weak-coupling BCS value of 5.9 meV for the bulk T-c of 39 K. The low value of Delta compared to the BCS value for the bulk T-c is possibly due to chemical reactions at the surface. C1 Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. IIT, Div Phys, Chicago, IL 60616 USA. RP Schmidt, H (reprint author), Argonne Natl Lab, Div Mat Sci, 9700 S Cass Ave, Argonne, IL 60439 USA. NR 23 TC 101 Z9 101 U1 0 U2 1 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 EI 1550-235X J9 PHYS REV B JI Phys. Rev. B PD JUN 1 PY 2001 VL 63 IS 22 AR 220504 DI 10.1103/PhysRevB.63.220504 PG 4 WC Physics, Condensed Matter SC Physics GA 442KD UT WOS:000169283000011 ER PT J AU Tulk, CA Klug, DD AF Tulk, CA Klug, DD TI Formation of amorphous ice by careful annealing of ice XII SO PHYSICAL REVIEW B LA English DT Article ID GLASSY WATER; INDUCED AMORPHIZATION; NEUTRON-SCATTERING; LOW-TEMPERATURE; PRESSURE; VIII; SPECTRUM; PHASES; LIQUID AB Thermally induced transformations of ice XII were characterized using the Raman spectra of the isolated O-D vibration of 5% HDO molecules in H2O ice XII. Spectra were collected continuously as samples were annealed between 77-160 K. Raman spectra first show a sharp peak centered on Delta nu =2424 cm(-1) from ice XII at 120 K. As the sample is further annealed isothermally at 120 K this peak broadens and shifts to higher frequency Delta nu =2439 cm(-1) and full width at half maximum 65 cm(-1). indicating the production of low-density amorphous ice by decompression amorphization. Ice Ic is formed upon further annealing at 130-140 K. The local hydrogen bond strength of the resulting amorphous phase was found to be close to that of glassy water. C1 Natl Res Council Canada, Steacie Inst Mol Sci, Ottawa, ON K1A 6A4, Canada. RP Tulk, CA (reprint author), Argonne Natl Lab, Oak Ridge Natl Lab, Spallat Neutron Source, 9700 S Cass Ave, Argonne, IL 60439 USA. RI Tulk, Chris/R-6088-2016 OI Tulk, Chris/0000-0003-3400-3878 NR 24 TC 14 Z9 14 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 JUN 1 PY 2001 VL 63 IS 21 AR 212201 DI 10.1103/PhysRevB.63.212201 PG 4 WC Physics, Condensed Matter SC Physics GA 438NV UT WOS:000169060700003 ER PT J AU Vogt, T Schneider, G Hriljac, JA Yang, G Abell, JS AF Vogt, T Schneider, G Hriljac, JA Yang, G Abell, JS TI Compressibility and electronic structure of MgB2 up to 8 GPa SO PHYSICAL REVIEW B LA English DT Article ID GENERALIZED GRADIENT APPROXIMATION; PLANE-WAVE METHOD AB The lattice parameters of MgB2 up to a pressure of 8 GPa were determined using high-resolution x-ray powder diffraction in a diamond anvil cell. The bulk modulus, B-0, was determined to be 151 +/-5 GPa. Both experimental and first-principles calculations indicate nearly isotropic mechanical behavior under pressure. This small anisotropy is in contrast to the two-dimensional nature of the boron p states. The pressure dependence of the density of states at the Fermi level and a reasonable value for the average phonon frequency (omega) account within the context of BCS theory for the reduction of T-c under pressure. C1 Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. Univ Birmingham, Sch Chem, Birmingham B15 2TT, W Midlands, England. Univ Birmingham, Sch Met & Mat, Birmingham B15 2TT, W Midlands, England. RP Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. RI Vogt, Thomas /A-1562-2011 OI Vogt, Thomas /0000-0002-4731-2787 NR 25 TC 104 Z9 106 U1 3 U2 12 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 EI 1550-235X J9 PHYS REV B JI Phys. Rev. B PD JUN 1 PY 2001 VL 63 IS 22 AR 220505 DI 10.1103/PhysRevB.63.220505 PG 3 WC Physics, Condensed Matter SC Physics GA 442KD UT WOS:000169283000012 ER PT J AU Yoo, YK Duewer, F Fukumura, T Yang, HT Yi, D Liu, S Chang, HY Hasegawa, T Kawasaki, M Koinuma, H Xiang, X AF Yoo, YK Duewer, F Fukumura, T Yang, HT Yi, D Liu, S Chang, HY Hasegawa, T Kawasaki, M Koinuma, H Xiang, X TI Strong correlation between high-temperature electronic and low-temperature magnetic ordering in Lal(1-x)Ca(x)MnO(3) continuous phase SO PHYSICAL REVIEW B LA English DT Article ID COLOSSAL MAGNETORESISTANCE; MANGANESE OXIDES; CHARGE; MICROSCOPY; STATE; SUPERCONDUCTIVITY; LA1.2SR1.8MN2O7; SCATTERING; MANGANITES; TRANSPORT AB Optical and microwave impedance and magnetic mapping of continuous phase diagram of thin film La1-xCaxMnO3 was achieved on a single chip. The optical and microwave impedance images obtained by charge-coupled device camera and scanned evanescent microwave probe showed abrupt variations in visible wavelength reflectance and microwave impedance as functions of composition at room temperature. The low-temperature magnetic order probed by scanning superconducting quantum interference device microscope is directly correlated with the room-temperature electrical impedance variation. Most of these variations may arise from remnant electronic orbital ordering persisting to room temperature in these compounds. We also observed a narrow singular stripe in composition with dramatically increased conductivity. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Environm Energy Technol Div, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. Tokyo Inst Technol, Dept Innovat & Engineered Mat, Midori Ku, Yokohama, Kanagawa 2268502, Japan. Tokyo Inst Technol, Mat & Struct Lab, Midori Ku, Yokohama, Kanagawa 2268503, Japan. Tokyo Inst Technol, Leading Project Combinatorial Mat Sci & Technol, Midori Ku, Yokohama, Kanagawa 2268503, Japan. RP Xiang, X (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Environm Energy Technol Div, Berkeley, CA 94720 USA. EM xdxiang@hotmail.com RI Kawasaki, Masashi/B-5826-2008; Fukumura, Tomoteru/C-2081-2009; Xiang, Xiaodong/A-9445-2012 OI Fukumura, Tomoteru/0000-0002-8957-3520; NR 23 TC 12 Z9 14 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 JUN 1 PY 2001 VL 63 IS 22 AR 224421 DI 10.1103/PhysRevB.63.224421 PG 5 WC Physics, Condensed Matter SC Physics GA 442KD UT WOS:000169283000066 ER PT J AU Yoshida, T Zhou, XJ Nakamura, M Kellar, SA Bogdanov, PV Lu, ED Lanzara, A Hussain, Z Ino, A Mizokawa, T Fujimori, A Eisaki, H Kim, C Shen, ZX Kakeshita, T Uchida, S AF Yoshida, T Zhou, XJ Nakamura, M Kellar, SA Bogdanov, PV Lu, ED Lanzara, A Hussain, Z Ino, A Mizokawa, T Fujimori, A Eisaki, H Kim, C Shen, ZX Kakeshita, T Uchida, S TI Electronlike Fermi surface and remnant (pi,0) feature in overdoped La1.78Sr0.22CuO4 SO PHYSICAL REVIEW B LA English DT Article ID ANGLE-RESOLVED PHOTOEMISSION; LA2-XSRXCUO4; BI2SR2CACU2O8+DELTA; BEHAVIOR; STRIPES; STATES; BAND AB We have performed an angle-resolved photoemission study of overdoped La1.78Sr0.22CuO4, and have observed sharp nodal quasiparticle peaks in the second Brillouin zone that are comparable to data from Bi2Sr2CaCu2O8+delta The data analysis using energy distribution curves, momentum distribution curves, and intensity maps all show evidence of an electronlike Fermi surface, which is well explained by band-structure calculations. Evidence for many-body effects are also found in the substantial spectral weight remaining below the Fermi level around ( pi ,0), where the band is predicted to lie above E-F. C1 Univ Tokyo, Dept Phys, Bunkyo Ku, Tokyo 1130033, Japan. Stanford Univ, Dept Appl Phys, Stanford, CA 94305 USA. Stanford Univ, Stanford Synchrotron Radiat Lab, Stanford, CA 94305 USA. Nara Univ Educ, Dept Phys, Nara 6308523, Japan. Lawrence Berkeley Natl Lab, Adv Light Source, Berkeley, CA 94720 USA. Japan Atom Energy Res Inst, Synchrotron Radiat Res Ctr, Sayo, Hyogo 6795198, Japan. Univ Tokyo, Dept Adv Mat Sci, Bunkyo Ku, Tokyo 1138656, Japan. Univ Tokyo, Dept Complex Sci & Engn, Bunkyo Ku, Tokyo 1130033, Japan. RP Yoshida, T (reprint author), Univ Tokyo, Dept Phys, Bunkyo Ku, Tokyo 1130033, Japan. RI Mizokawa, Takashi/E-3302-2015 OI Mizokawa, Takashi/0000-0002-7682-2348 NR 24 TC 46 Z9 47 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 JUN 1 PY 2001 VL 63 IS 22 AR 220501 DI 10.1103/PhysRevB.63.220501 PG 4 WC Physics, Condensed Matter SC Physics GA 442KD UT WOS:000169283000008 ER PT J AU Abbott, T Ahle, L Akiba, Y Alburger, D Beavis, D Birstein, L Bloomer, MA Bond, PD Britt, HC Budick, B Chasman, C Chen, Z Chi, CY Chu, YY Cianciolo, V Cole, BA Costales, JB Crawford, HJ Cumming, JB Debbe, R Duek, E Engelage, J Fung, SY Gonin, M Grodzins, L Gushue, S Hamagaki, H Hansen, O Hayano, RS Hayashi, S Homma, S Huang, HZ Ikeda, Y Juricic, I Kaneko, H Kang, J Katcoff, S Kaufman, S Kehoe, WL Kimura, K Kitamura, K Kurita, K Ledoux, RJ LeVine, MJ Miake, Y Morrison, DP Morse, RJ Moskowitz, B Nagamiya, S Namboodiri, MN Nayak, TK Olness, J Parsons, CG Remsberg, LP Rothschild, P Sakurai, H Sangster, TC Sarabura, M Seto, R Shigaki, K Shor, A Soltz, R Stankus, P Steadman, SG Stephans, GSF Sugitate, T Sung, T Tanaka, M Tannenbaum, MJ Thomas, J Tonse, S Torikoshi, M Ueno-Hayashi, S van Dijk, JH Videbaek, F Vient, M Vincent, P Vossnack, O Vulgaris, E Vutsadakis, V Wang, FQ Wang, Y Watson, WA Wegner, HE Woodruff, DS Wu, YD Yagi, K Yang, X Zachary, D Zajc, WA AF Abbott, T Ahle, L Akiba, Y Alburger, D Beavis, D Birstein, L Bloomer, MA Bond, PD Britt, HC Budick, B Chasman, C Chen, Z Chi, CY Chu, YY Cianciolo, V Cole, BA Costales, JB Crawford, HJ Cumming, JB Debbe, R Duek, E Engelage, J Fung, SY Gonin, M Grodzins, L Gushue, S Hamagaki, H Hansen, O Hayano, RS Hayashi, S Homma, S Huang, HZ Ikeda, Y Juricic, I Kaneko, H Kang, J Katcoff, S Kaufman, S Kehoe, WL Kimura, K Kitamura, K Kurita, K Ledoux, RJ LeVine, MJ Miake, Y Morrison, DP Morse, RJ Moskowitz, B Nagamiya, S Namboodiri, MN Nayak, TK Olness, J Parsons, CG Remsberg, LP Rothschild, P Sakurai, H Sangster, TC Sarabura, M Seto, R Shigaki, K Shor, A Soltz, R Stankus, P Steadman, SG Stephans, GSF Sugitate, T Sung, T Tanaka, M Tannenbaum, MJ Thomas, J Tonse, S Torikoshi, M Ueno-Hayashi, S van Dijk, JH Videbaek, F Vient, M Vincent, P Vossnack, O Vulgaris, E Vutsadakis, V Wang, FQ Wang, Y Watson, WA Wegner, HE Woodruff, DS Wu, YD Yagi, K Yang, X Zachary, D Zajc, WA TI Systematics of midrapidity transverse energy distributions in limited apertures from p+Be to Au+Au collisions at relativistic energies SO PHYSICAL REVIEW C LA English DT Article ID HEAVY-ION COLLISIONS; NUCLEUS-NUCLEUS COLLISIONS; CENTRAL RAPIDITY REGION; 200 GEV NUCLEON; MULTIPLICITY DISTRIBUTIONS; MULTIPARTICLE PRODUCTION; PARTICLE-PRODUCTION; 14.6A GEV/C; ALPHA-ALPHA; 11.6A GEV/C AB Measurements of the A dependence and pseudorapidity interval (delta eta) dependence of midrapidity E-T distributions in a half-azimuth (Delta phi = pi) electromagnetic calorimeter are presented for p + Be, p + Au, O + Cu, Si + Au, and Au + Au collisions at the BNL-AGS (Alternating-Gradient Synchrotron). The shapes of the upper edges of midrapidity E-T distributions as a function of the pseudorapidity interval delta eta in the range 0.3 to 1.3, roughly centered at midrapidity, are observed to vary with delta eta. like multiplicity-the upper edges of the distributions flatten as delta eta is reduced. At the typical fixed upper percentiles of E-T distributions used for nuclear geometry characterization by centrality definition-7 percentile, 4 percentile, 2 percentile, I percentile, 0.5 percentile-the effect of this variation in shape on the measured projectile A(p) dependence for O-16, Si-28, Au-197 projectiles on an Au target is small for the ranges of delta eta and percentile examined. The E-T distributions for p + Au and p + Be change in shape with delta eta; but in each delta eta interval the shapes of the p + Au and p + Be distributions remain indentical with each other-a striking confirmation of the absence of multiple-collision effects at midrapidity at AGS energies. The validity of the nuclear geometry characterization versus delta eta is illustrated by plots of the E-T(delta eta) distribution in each delta eta interval in units of the measured (p + Au) same delta eta interval for p + Au collisions. These plots, in the physically meaningful units of "number of average p + Au collisions," are nearly universal as a function of delta eta confirming that the reaction dynamics for E-T production at midrapidity at AGS energies is governed by the number of projectile participants and can be well characterized by measurements in apertures as small as Delta phi = pi, delta eta = 0.3. C1 Argonne Natl Lab, Argonne, IL 60439 USA. Brookhaven Natl Lab, Upton, NY 11973 USA. Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA. Univ Calif Riverside, Riverside, CA 92507 USA. Columbia Univ, New York, NY 10027 USA. Nevis Labs, Irvington, NY 10533 USA. High Energy Accelerator Res Org, Tsukuba, Ibaraki 305, Japan. High Energy Accelerator Res Org, Tanashi Branch, Tokyo 188, Japan. Hiroshima Univ, Hiroshima 730, Japan. Kyoto Univ, Sakyo Ku, Kyoto 606, Japan. Kyushu Univ, Fukuoka 812, Japan. Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. MIT, Cambridge, MA 02139 USA. NYU, New York, NY 10003 USA. Univ Tokyo, Sch Sci, Ctr Nucl Study, Tanashi, Tokyo 188, Japan. Univ Tokyo, Dept Phys, Tokyo 113, Japan. Univ Tsukuba, Tsukuba, Ibaraki 305, Japan. Yonsei Univ, Seoul 120749, South Korea. RP Abbott, T (reprint author), Reedley Coll, Reedley, CA 93654 USA. RI seto, richard/G-8467-2011; Duek, Eliana/J-2499-2012; SAKURAI, HIROYOSHI/G-5085-2014; Hayano, Ryugo/F-7889-2012; HAMAGAKI, HIDEKI/G-4899-2014; Cumming, James/I-3358-2013 OI Hayano, Ryugo/0000-0002-1214-7806; Cumming, James/0000-0001-6930-0958 NR 98 TC 19 Z9 19 U1 0 U2 2 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2813 EI 1089-490X J9 PHYS REV C JI Phys. Rev. C PD JUN PY 2001 VL 63 IS 6 AR 064602 DI 10.1103/PhysRevC.63.064602 PG 25 WC Physics, Nuclear SC Physics GA 440NX UT WOS:000169182200033 ER PT J AU Bardayan, DW Blackmon, JC Bradfield-Smith, W Brune, CR Chamagne, AE Davinson, T Johnson, BA Kozub, RL Lee, CS Lewis, R Parker, PD Shotter, AC Smith, MS Visser, DW Woods, PJ AF Bardayan, DW Blackmon, JC Bradfield-Smith, W Brune, CR Chamagne, AE Davinson, T Johnson, BA Kozub, RL Lee, CS Lewis, R Parker, PD Shotter, AC Smith, MS Visser, DW Woods, PJ TI Destruction of F-18 via F-18(p,alpha)O-15 burning through the E-c.m.=665 keV resonance SO PHYSICAL REVIEW C LA English DT Article ID POSITRON-ANNIHILATION; REACTION-RATES; NOVAE; BEAM; CALIBRATION; SCATTERING; ENERGIES; STATE; NE-19 AB Knowledge of the astrophysical rate of the F-18(p, alpha)O-15 reaction is important for understanding the gamma -ray emission expected from novae and heavy-element production in x-ray bursts. The rate of this reaction is dominated at temperatures above similar to0.4 GK by a resonance near 7.08 MeV excitation energy in Ne-19. The F-18(p, alpha) O-15 rate has been uncertain in part because of disagreements among previous measurements concerning the resonance strength and excitation energy of this state. To resolve these uncertainties, we have made simultaneous measurements of the H-1(F-18, p)F-18 and H-1(F-18, alpha)O-15 excitation functions using a radioactive F-18 beam at the ORNL Holifield Radioactive Ion Beam Facility. A simultaneous fit of the data sets has been performed, and the best fit was obtained with a center-of-mass resonance energy of 664.7 +/- 1.6 keV (E-chi = 7076 +/- 2 keV), a total width of 39.0 +/- 1.6 keV, a proton branching ratio of Gamma (p)/Gamma= 0.39 +/- 0.02, and a resonance strength of omega gamma = 6.2 +/- 0.3 keV. C1 Oak Ridge Natl Lab, Div Phys, Oak Ridge, TN 37831 USA. Univ N Carolina, Dept Phys & Astron, Chapel Hill, NC 27599 USA. Yale Univ, AW Wright Nucl Struct Lab, New Haven, CT 06511 USA. Univ Edinburgh, Dept Phys & Astron, Edinburgh EH9 3JZ, Midlothian, Scotland. Tennessee Technol Univ, Dept Phys, Cookeville, TN 38505 USA. Chung Ang Univ, Dept Phys, Seoul 156756, South Korea. RP Bardayan, DW (reprint author), Oak Ridge Natl Lab, Div Phys, Oak Ridge, TN 37831 USA. RI Visser, Dale/A-8117-2009 OI Visser, Dale/0000-0002-2891-4731 NR 28 TC 95 Z9 95 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 JUN PY 2001 VL 63 IS 6 AR 065802 DI 10.1103/PhysRevC.63.065802 PG 6 WC Physics, Nuclear SC Physics GA 440NX UT WOS:000169182200054 ER PT J AU Bravina, LV Zabrodin, EE Bass, SA Bleicher, M Brandstetter, M Faessler, A Fuchs, C Greiner, W Soff, S Stocker, H AF Bravina, LV Zabrodin, EE Bass, SA Bleicher, M Brandstetter, M Faessler, A Fuchs, C Greiner, W Soff, S Stocker, H TI Equation of state of resonance-rich matter in the central cell in heavy-ion collisions at root s=200A GeV SO PHYSICAL REVIEW C LA English DT Article ID NUCLEUS-NUCLEUS COLLISIONS; QUANTUM MOLECULAR-DYNAMICS; THERMAL HADRON-PRODUCTION; FREEZE-OUT PARAMETERS; PLUS PB COLLISIONS; QUARK-GLUON PLASMA; CHEMICAL EQUILIBRATION; OF-STATE; GAS MODELS; 200A GEV AB The equilibration of hot and dense nuclear matter produced in the central cell of central Au + Au collisions at roots = 200A GeV is studied within a microscopic transport model. The pressure in the cell becomes isotropic at t approximate to 5 fm/c after beginning of the collision. Within the next 15 fm/c the expansion of matter in the cell proceeds almost isentropically with the entropy per baryon ratio S/A congruent to 150, and the equation of state in the (P,epsilon) plane has a very simple form, P = 0.15 epsilon. Comparison with the statistical model of an ideal hadron gas indicates that the time t approximate to 20 fm/c may be too short to reach the fully equilibrated state. Particularly, the creation of long-lived resonance-rich matter in the cell decelerates the relaxation to chemical equilibrium. This resonance-abundant state can be detected experimentally after the thermal freeze out of particles. 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 48824 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Nucl Sci, Berkeley, CA 94720 USA. Univ Frankfurt, Inst Theoret Phys, D-60325 Frankfurt, Germany. Gesell Schwerionenforsch mbH, D-64220 Darmstadt, Germany. RP Bravina, LV (reprint author), Univ Tubingen, Inst Theoret Phys, D-72076 Tubingen, Germany. RI Bleicher, Marcus/A-2758-2010; Stoecker, Horst/D-6173-2013 OI Stoecker, Horst/0000-0002-3282-3664 NR 49 TC 21 Z9 21 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2813 J9 PHYS REV C JI Phys. Rev. C PD JUN PY 2001 VL 63 IS 6 AR 064902 DI 10.1103/PhysRevC.63.064902 PG 8 WC Physics, Nuclear SC Physics GA 440NX UT WOS:000169182200043 ER PT J AU Davids, B Austin, SM Bazin, D Esbensen, H Sherrill, BM Thompson, IJ Tostevin, JA AF Davids, B Austin, SM Bazin, D Esbensen, H Sherrill, BM Thompson, IJ Tostevin, JA TI Electromagnetic dissociation of B-8 and the rate of the Be-7(p, gamma)B-8 reaction in the Sun SO PHYSICAL REVIEW C LA English DT Article ID BE-7(P,GAMMA)B-8 CROSS-SECTION; RADIATIVE-CAPTURE PROCESSES; COULOMB DISSOCIATION; LOW ENERGIES; S-FACTOR; ASTROPHYSICAL INTEREST; CHANNELS CALCULATIONS; E2 TRANSITIONS; BREAKUP; NUCLEAR AB In an effort to better determine the Be-7(p, gamma)B-8 reaction rate, we have performed inclusive and exclusive measurements of the Coulomb dissociation of B-8. The former was a study of longitudinal momentum distributions of Be-7 fragments emitted in the Coulomb breakup of intermediate energy B-8 beams on Pb and Ag targets. Analysis of these data yielded the E2 contribution to the breakup cross section. In the exclusive measurement. we determined the cross section for the Coulomb breakup of B-8 on Pb at low relative energies in order to infer the astrophysical S factor for the Be-7(p, gamma)B-8 reaction. Interpreting the measurements with first-order perturbation theory, we obtained S-E2/S-E1 = 4.7(-1.3)(+2.0) x 10(-4) at E-rel = 0.6 MeV, and S-17(0) =17.8(-1.2)(+1.4) eV b. Semiclassical first-order perturbation theory and fully quantum mechanical continuum-discretized coupled channels analyses yield nearly identical results for the El strength relevant to solar neutrino flux calculations, suggesting that theoretical reaction mechanism uncertainties need not limit the precision of Coulomb breakup determinations of the Be-7(p, gamma)B-8 S factor. A recommended value of S-17(0) based on a weighted average of this and other measurements is presented. C1 Michigan State Univ, Natl Superconducting Cyclotron Lab, E Lansing, MI 48824 USA. Michigan State Univ, Dept Phys & Astron, E Lansing, MI 48824 USA. Argonne Natl Lab, Div Phys, Argonne, IL 60439 USA. Univ Surrey, Dept Phys, Sch Phys & Chem, Guildford GU2 5XH, Surrey, England. RP Davids, B (reprint author), Univ Groningen, Kernfys Versneller Inst, Zernikelaan 25, NL-9747 AA Groningen, Netherlands. EM davids@kvi.nl RI Sherrill, Bradley/B-4098-2009; Sherrill, Bradley/B-3378-2011 NR 52 TC 80 Z9 81 U1 1 U2 1 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2813 J9 PHYS REV C JI Phys. Rev. C PD JUN PY 2001 VL 63 IS 6 AR 065806 DI 10.1103/PhysRevC.63.065806 PG 14 WC Physics, Nuclear SC Physics GA 440NX UT WOS:000169182200058 ER PT J AU Hindi, MM Faircloth, BO Kozub, RL Czerwinski, KR Larimer, RM Norman, EB Sur, B Zlimen, I AF Hindi, MM Faircloth, BO Kozub, RL Czerwinski, KR Larimer, RM Norman, EB Sur, B Zlimen, I TI Q(EC) value and internal bremsstrahlung spectre of Ta-179 SO PHYSICAL REVIEW C LA English DT Article ID ELECTRON-CAPTURE DECAY; NEUTRINO; CE-139; HO-163; I-125 AB The total and 2p internal bremsstrahlung spectra accompanying the electron capture decay of Ta-179 have been measured in singles and in coincidence with L x rays, respectively. The intensity of the total spectrum was found to be (1.131 +/- 0.027) times that predicted by the calculations of Suric et al.; the intensity of the 2p spectrum was found to be ( 1.097 +/- 0.028) times those calculations. The disagreement with theory is thus much smaller than the factor of 1.5-2 previously reported for Pt-193. The Q(EC) value determined from the internal bremsstrahlung end point energy was found to be 105.61 +/- 0.41 keV. An independent value for Q(EC) Of 109.3 +/- 3.1 keV was determined by measuring the L to K capture ratio. C1 Tennessee Technol Univ, Dept Phys, Cookeville, TN 38505 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Nucl Sci, Berkeley, CA 94720 USA. RP Hindi, MM (reprint author), Celoxica Inc, 900 E Hamilton Ave,Suite 150, Campbell, CA 95008 USA. NR 21 TC 3 Z9 3 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2813 J9 PHYS REV C JI Phys. Rev. C PD JUN PY 2001 VL 63 IS 6 AR 065502 DI 10.1103/PhysRevC.63.065502 PG 10 WC Physics, Nuclear SC Physics GA 440NX UT WOS:000169182200052 ER PT J AU Kievsky, A Friar, JL Payne, GL Rosati, S Viviani, M AF Kievsky, A Friar, JL Payne, GL Rosati, S Viviani, M TI Phase shifts and mixing parameters for low-energy proton-deuteron scattering SO PHYSICAL REVIEW C LA English DT Article ID POLARIZATION OBSERVABLES; 3-NUCLEON SCATTERING; BENCHMARK SOLUTIONS; ELASTIC-SCATTERING; POTENTIALS; BREAKUP AB The eigenphase shifts and mixing parameters for p-d elastic scattering below the deuteron-breakup threshold are calculated for the AV14 two-body potential using two different numerical methods. The excellent agree ment confirms that it is possible to perform accurate numerical studies of p-d scattering as well as n-d scattering for energies below the three-body breakup threshold. The numerical results can be considered as benchmarks for future calculations. C1 Ist Nazl Fis Nucl, I-56100 Pisa, Italy. Univ Calif Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. Univ Iowa, Dept Phys & Astron, Iowa City, IA 52242 USA. Univ Pisa, Dipartimento Fis, I-56100 Pisa, Italy. RP Kievsky, A (reprint author), Ist Nazl Fis Nucl, Piazza Torricelli 2, I-56100 Pisa, Italy. RI kievsky, alejandro/A-7123-2011 NR 13 TC 16 Z9 16 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 JUN PY 2001 VL 63 IS 6 AR 064004 DI 10.1103/PhysRevC.63.064004 PG 3 WC Physics, Nuclear SC Physics GA 440NX UT WOS:000169182200015 ER PT J AU Kruppa, AT Varga, K Revai, J AF Kruppa, AT Varga, K Revai, J TI Local realizations of contact interactions in two- and three-body problems SO PHYSICAL REVIEW C LA English DT Article ID SHORT-RANGE INTERACTIONS; EFFECTIVE-FIELD THEORY; QUANTUM-MECHANICS; DRIP-LINE; RENORMALIZATION; REGULARIZATION; POTENTIALS; SCATTERING; SYSTEM; NUCLEI AB Based on the self-adjoint extension theory mathematically rigorously defined two-body contact interaction in three dimension is reviewed. Local potential realizations of this proper contact interaction are given in terms of Poschl-Teller, exponential, and square-well potentials. Three-body calculation is carried out for the halo nucleus Li-11 using adequately represented contact interaction. C1 Hungarian Acad Sci, Inst Nucl Res, H-4001 Debrecen, Hungary. Argonne Natl Lab, Div Phys, Argonne, IL 60439 USA. KFKI, Res Inst Particle & Nucl Phys, H-1525 Budapest, Hungary. RP Kruppa, AT (reprint author), Hungarian Acad Sci, Inst Nucl Res, Pf 51, H-4001 Debrecen, Hungary. RI Varga, Kalman/A-7102-2013; Revai, Janos /B-3893-2016 NR 33 TC 5 Z9 5 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 JUN PY 2001 VL 63 IS 6 AR 064301 DI 10.1103/PhysRevC.63.064301 PG 8 WC Physics, Nuclear SC Physics GA 440NX UT WOS:000169182200016 ER PT J AU Lukashin, K Smith, ES Adams, GS Anciant, E Anghinolfi, M Asavapibhop, B Audit, G Auger, T Avakian, H Ball, J Barrow, S Battaglieri, M Beard, K Bektasoglu, M Bertozzi, W Bianchi, N Biselli, A Boiarinov, S Bonner, BE Bouchigny, S Branford, D Briscoe, WJ Brooks, WK Burkert, VD Calarco, JR Carman, DS Carnahan, B Ciciani, L Clark, R Cole, PL Coleman, A Cords, D Corvisiero, P Crabb, D Crannell, H Cummings, J Degtiarenko, PV Dennis, LC De Sanctis, E DeVita, R Dhuga, KS Djalali, C Dodge, GE Domingo, J Doughty, D Dragovitsch, P Dytman, S Eckhause, M Egiyan, H Egiyan, KS Elouadrhiri, L Empl, A Fatemi, R Feuerbach, RJ Ficenec, J Fissum, K Forest, TA Freyberger, A Funsten, H Gaff, S Gai, M Gavalian, G Gilad, S Gilfoyle, G Giovanetti, K Girard, P Griffioen, KA Guidal, M Guillo, M Gyurjyan, V Hardie, J Heddle, D Hersman, FW Hicks, K Hicks, RS Holtrop, M Hu, J Hyde-Wright, CE Ito, MM Jenkins, D Joo, K Kelley, J Khandaker, M Kim, K Kim, KY Kim, W Klein, A Klein, FJ Klusman, M Kossov, M Kramer, LH Kuhn, SE Laget, JM Lawrence, D Longhi, A Manak, JJ Marchand, C McAleer, S McCarthy, J McNabb, JWC Mecking, BA Mestayer, MD Meyer, CA Mikhailov, K Minehart, R Mirazita, M Miskimen, R Muccifora, V Mueller, J Mutchler, GS Napolitano, J Nelson, S Niculescu, G Niculescu, I Niczyporuk, BB Niyazov, RA Opper, A O'Rielly, G O'Brien, JT Park, K Paschke, K Pasyuk, E Peterson, GA Philips, S Pivnyuk, N Pocanic, D Pogorelko, O Polli, E Pozdniakov, S Preedom, BM Price, JW Qin, LM Raue, BA Reolon, AR Riccardi, G Ricco, G Ripani, M Ritchie, BG Ronchetti, F Rossi, P Rowntree, D Rubin, PD Sabatie, F Sabourov, K Salgado, CW Sapunenko, V Schumacher, RA Serov, V Sharabian, YG Shaw, J Simionatto, S Skabelin, A Smith, LC Sober, DI Stavinsky, A Stepanyan, S Stoler, P Strakovsky, II Taiuti, M Taylor, S Tedeschi, D Thompson, R Vineyard, MF Vlassov, A Wang, K Weller, H Weinstein, LB Welsh, R Weygand, DP Whisnant, S Wolin, E Yanik, L Yegneswaran, A Yun, J Zhao, J Zhang, B Zhou, Z AF Lukashin, K Smith, ES Adams, GS Anciant, E Anghinolfi, M Asavapibhop, B Audit, G Auger, T Avakian, H Ball, J Barrow, S Battaglieri, M Beard, K Bektasoglu, M Bertozzi, W Bianchi, N Biselli, A Boiarinov, S Bonner, BE Bouchigny, S Branford, D Briscoe, WJ Brooks, WK Burkert, VD Calarco, JR Carman, DS Carnahan, B Ciciani, L Clark, R Cole, PL Coleman, A Cords, D Corvisiero, P Crabb, D Crannell, H Cummings, J Degtiarenko, PV Dennis, LC De Sanctis, E DeVita, R Dhuga, KS Djalali, C Dodge, GE Domingo, J Doughty, D Dragovitsch, P Dytman, S Eckhause, M Egiyan, H Egiyan, KS Elouadrhiri, L Empl, A Fatemi, R Feuerbach, RJ Ficenec, J Fissum, K Forest, TA Freyberger, A Funsten, H Gaff, S Gai, M Gavalian, G Gilad, S Gilfoyle, G Giovanetti, K Girard, P Griffioen, KA Guidal, M Guillo, M Gyurjyan, V Hardie, J Heddle, D Hersman, FW Hicks, K Hicks, RS Holtrop, M Hu, J Hyde-Wright, CE Ito, MM Jenkins, D Joo, K Kelley, J Khandaker, M Kim, K Kim, KY Kim, W Klein, A Klein, FJ Klusman, M Kossov, M Kramer, LH Kuhn, SE Laget, JM Lawrence, D Longhi, A Manak, JJ Marchand, C McAleer, S McCarthy, J McNabb, JWC Mecking, BA Mestayer, MD Meyer, CA Mikhailov, K Minehart, R Mirazita, M Miskimen, R Muccifora, V Mueller, J Mutchler, GS Napolitano, J Nelson, S Niculescu, G Niculescu, I Niczyporuk, BB Niyazov, RA Opper, A O'Rielly, G O'Brien, JT Park, K Paschke, K Pasyuk, E Peterson, GA Philips, S Pivnyuk, N Pocanic, D Pogorelko, O Polli, E Pozdniakov, S Preedom, BM Price, JW Qin, LM Raue, BA Reolon, AR Riccardi, G Ricco, G Ripani, M Ritchie, BG Ronchetti, F Rossi, P Rowntree, D Rubin, PD Sabatie, F Sabourov, K Salgado, CW Sapunenko, V Schumacher, RA Serov, V Sharabian, YG Shaw, J Simionatto, S Skabelin, A Smith, LC Sober, DI Stavinsky, A Stepanyan, S Stoler, P Strakovsky, II Taiuti, M Taylor, S Tedeschi, D Thompson, R Vineyard, MF Vlassov, A Wang, K Weller, H Weinstein, LB Welsh, R Weygand, DP Whisnant, S Wolin, E Yanik, L Yegneswaran, A Yun, J Zhao, J Zhang, B Zhou, Z CA CLAS Collaboration TI Exclusive electroproduction of phi mesons at 4.2 GeV SO PHYSICAL REVIEW C LA English DT Article ID LARGE MOMENTUM-TRANSFER; VECTOR-MESONS; ELASTIC-SCATTERING; PHOTOPRODUCTION; HERA; DEEP; RHO(0); PROTON; SYSTEM; CLAS AB We studied the exclusive reaction ep --> e' p' phi using the phi -->K+ K- decay mode. The data were collected using a 4.2 GeV incident electron beam and the CEBAF Large Acceptance Spectrometer (CLAS) at the Thomas Jefferson National Accelerator Facility. Our experiment covers the range in Q(2) from 0.7 to 2.2 GeV2 and W from 2.0 to 2.6 GeV. Taken together with all previous data, we find a consistent picture of phi production on the proton. Our measurement shows the expected decrease of the t slope with the vector-meson formation time c Delta tau below 2 fm. At = 0.6 fm, we measure b(phi) = 2.27 +/- 0.42 GeV-2. The cross section dependence on W as W0.2 +/- 0.1 at Q(2), 1.3 GeV2 was determined by comparison with phi production at HERA after correcting for threshold effects. This is the same dependence as observed in photoproduction. C1 Virginia Polytech Inst & State Univ, Dept Phys, Blacksburg, VA 24061 USA. Thomas Jefferson Natl Accelerator Facil, Newport News, VA 23606 USA. Arizona State Univ, Dept Phys & Astron, Tempe, AZ 85287 USA. Univ Calif Los Angeles, Dept Phys & Astron, Los Angeles, CA 90095 USA. Carnegie Mellon Univ, Dept Phys, Pittsburgh, PA 15213 USA. Catholic Univ Amer, Dept Phys, Washington, DC 20064 USA. CEA Saclay, DAPNIA SPhN, F-91191 Gif Sur Yvette, France. Christopher Newport Univ, Newport News, VA 23606 USA. Univ Connecticut, Dept Phys, Storrs, CT 06269 USA. Duke Univ, Dept Phys, Durham, NC 27706 USA. Univ Edinburgh, Dept Phys & Astron, Edinburgh EH9 3JZ, Midlothian, Scotland. Florida Int Univ, Dept Phys, Miami, FL 33199 USA. Florida State Univ, Dept Phys, Tallahassee, FL 32306 USA. Ist Nazl Fis Nucl, Lab Nazl Frascati, I-00044 Frascati, Italy. Ist Nazl Fis Nucl, Sez Genova, I-16146 Genoa, Italy. Univ Genoa, Dipartimento Fis, I-16146 Genoa, Italy. George Washington Univ, Dept Phys, Washington, DC 20052 USA. Inst Theoret & Expt Phys, RU-117259 Moscow, Russia. James Madison Univ, Dept Phys, Harrisonburg, VA 22807 USA. Kyungpook Natl Univ, Dept Phys, Taegu 702701, South Korea. Univ Massachusetts, Dept Phys, Amherst, MA 01003 USA. MIT, Bates Linear Accelerator, Middleton, MA 01949 USA. Univ New Hampshire, Dept Phys, Durham, NH 03824 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. Inst Phys Nucl, IN2P3, F-91406 Orsay, France. Univ Pittsburgh, Dept Phys, Pittsburgh, PA 15260 USA. Rensselaer Polytech Inst, Dept Phys, Troy, NY 12181 USA. Rice Univ, TW Bonner Nucl Lab, Houston, TX 77005 USA. Univ Richmond, Dept Phys, Richmond, VA 23173 USA. RP Lukashin, K (reprint author), Catholic Univ Amer, Dept Phys, Washington, DC 20064 USA. RI Bektasoglu, Mehmet/A-2074-2012; riccardi, gabriele/A-9269-2012; Brooks, William/C-8636-2013; Schumacher, Reinhard/K-6455-2013; Sabatie, Franck/K-9066-2015; OI Brooks, William/0000-0001-6161-3570; Schumacher, Reinhard/0000-0002-3860-1827; Sabatie, Franck/0000-0001-7031-3975; Hyde, Charles/0000-0001-7282-8120 NR 46 TC 19 Z9 19 U1 0 U2 1 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2813 J9 PHYS REV C JI Phys. Rev. C PD JUN PY 2001 VL 63 IS 6 AR 065205 DI 10.1103/PhysRevC.63.065205 PG 11 WC Physics, Nuclear SC Physics GA 440NX UT WOS:000169182200050 ER PT J AU Mercer, DJ Austin, SM Brown, JA Danczyk, SA Hirzebruch, SE Kelley, JH Suomiyarvi, T Roberts, DA Walker, TP AF Mercer, DJ Austin, SM Brown, JA Danczyk, SA Hirzebruch, SE Kelley, JH Suomiyarvi, T Roberts, DA Walker, TP TI Production of A=6,7 nuclides in the alpha+alpha reaction and cosmic ray nucleosynthesis SO PHYSICAL REVIEW C LA English DT Article ID LIGHT-ELEMENTS; LI; ORIGIN; BERYLLIUM; EVOLUTION; BORON; STARS AB Cross sections for production of He-6, Li-6, Li-7, and Be-7 in the alpha + alpha reaction were measured at bombarding energies of 159.3, 279.6, and 619.8 MeV and are found to decrease rapidly with increasing energy. These cross sections are essential for the calculation of the rate of nucleosynthesis of the lithium isotopes in the cosmic rays and thereby play a key role in our understanding of the synthesis of Li, Be, and B. The results for Li-6 differ significantly from the tabulated values commonly used in cosmic ray production calculations and lead to lower production of Li-6. C1 Univ Colorado, Nucl Phys Lab, Boulder, CO 80309 USA. Michigan State Univ, Natl Superconducting Cyclotron Lab, E Lansing, MI 48824 USA. Michigan State Univ, Dept Phys & Astron, E Lansing, MI 48824 USA. Inst Phys Nucl, IN2P3, CNRS, F-91406 Orsay, France. Univ Michigan, Dept Phys, Ann Arbor, MI 48109 USA. Ohio State Univ, Dept Phys, Columbus, OH 43210 USA. RP Mercer, DJ (reprint author), Univ Calif Los Alamos Natl Lab, NIS Grp 5, POB 1663, Los Alamos, NM 87545 USA. EM mercer@lanl.gov; austin@nscl.msu.edu RI Brown, James/A-7373-2012 OI Brown, James/0000-0003-0548-8634 NR 20 TC 24 Z9 24 U1 0 U2 2 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2813 J9 PHYS REV C JI Phys. Rev. C PD JUN PY 2001 VL 63 IS 6 AR 065805 DI 10.1103/PhysRevC.63.065805 PG 7 WC Physics, Nuclear SC Physics GA 440NX UT WOS:000169182200057 ER PT J AU Randrup, J AF Randrup, J TI Probing chiral dynamics by charged-pion correlations SO PHYSICAL REVIEW C LA English DT Article ID CONDENSATE; COLLISIONS; BOSONS; DCC AB The environment generated in the midrapidity region of a high-energy nuclear collision endows the pionic degrees of freedom with a time-dependent effective mass. Its specific evolution provides a mechanism for the production of back-to-back charge-conjugate pairs of soft pions which may present an observable signal of the nonequilibrium dynamics of the chiral order parameter. 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 14 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 JUN PY 2001 VL 63 IS 6 AR 061901 DI 10.1103/PhysRevC.63.061901 PG 5 WC Physics, Nuclear SC Physics GA 440NX UT WOS:000169182200011 ER PT J AU Ressler, JJ Walters, WB Grzywacz, R Batchelder, JC Bingham, CR Gross, CJ Janas, Z Lipoglavsek, M McConnell, J Paul, SD Piechaczek, A Rykaczewski, K Radford, D Shergur, J AF Ressler, JJ Walters, WB Grzywacz, R Batchelder, JC Bingham, CR Gross, CJ Janas, Z Lipoglavsek, M McConnell, J Paul, SD Piechaczek, A Rykaczewski, K Radford, D Shergur, J TI Evidence for a strongly deformed band in Y-80 using isomer decay tagging SO PHYSICAL REVIEW C LA English DT Article ID NUCLEI; FRAGMENTATION; STATES AB The technique of isomer decay tagging (IDT) has been recently implemented at Oak Ridge National Laboratory to identify strongly deformed bands above a short-lived isomer in Y-80. The IDT method provides very clean reaction channel selection of prompt in-beam decays by correlating these events with delayed events detected at the focal plane of a recoil separator. Using this method, coincident transitions above and below a 4.7 mus isomer in Y-80 were observed. The placement of this isomer in the Y-80 level scheme is further confirmed and the deformed structure of the rotational bands built on the isomer is discussed. C1 Univ Maryland, Dept Chem, College Pk, MD 20742 USA. Argonne Natl Lab, Div Phys, Argonne, IL 60439 USA. Univ Tennessee, Dept Phys & Astron, Knoxville, TN 37996 USA. Univ Warsaw, PL-00681 Warsaw, Poland. Oak Ridge Natl Lab, Div Phys, Oak Ridge, TN 37831 USA. Oak Ridge Associated Univ, UNIRIB, Oak Ridge, TN 37831 USA. Vanderbilt Univ, Dept Phys & Astron, Nashville, TN 37235 USA. Louisiana State Univ, Dept Phys & Astron, Baton Rouge, LA 70803 USA. RP Ressler, JJ (reprint author), Univ Maryland, Dept Chem, College Pk, MD 20742 USA. RI Ressler, Jennifer Jo/F-2279-2010; radford, David/A-3928-2015 NR 14 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 0556-2813 J9 PHYS REV C JI Phys. Rev. C PD JUN PY 2001 VL 63 IS 6 AR 067303 DI 10.1103/PhysRevC.63.067303 PG 4 WC Physics, Nuclear SC Physics GA 440NX UT WOS:000169182200062 ER PT J AU Shuryak, EV Stephanov, MA AF Shuryak, EV Stephanov, MA TI Long-range charge fluctuations and search for a quark-gluon plasma signal SO PHYSICAL REVIEW C LA English DT Article ID HEAVY-ION COLLISIONS; BY-EVENT FLUCTUATIONS; PLUS PB COLLISIONS; EQUATION; STATE; STAGE; POINT; SPS; QCD AB We critically discuss a recent suggestion to use long-range modes of charge (electric or baryon) fluctuations as a signal for the presence of quark-gluon plasma at the early stages of a heavy ion collision. We evaluate the rate of diffusion in rapidity for different secondaries, and argue that for conditions of the Super Proton Synchrotron (SPS) experiments, it is strong enough to relax the magnitude of those fluctuations almost to its equilibrium values, given by hadronic "resonance gas." We evaluate the detector acceptance needed to measure such "primordial'' long-range fluctuations at Relativistic Heavy Ion Collider (RHIC) conditions. We conclude with an application of the charge fluctuation analysis to the search for the QCD critical point. C1 SUNY Stony Brook, Dept Phys & Astron, Stony Brook, NY 11794 USA. Univ Illinois, Dept Phys, Chicago, IL 60607 USA. Brookhaven Natl Lab, RIKEN BNL Res Ctr, Upton, NY 11973 USA. RP Shuryak, EV (reprint author), SUNY Stony Brook, Dept Phys & Astron, Stony Brook, NY 11794 USA. NR 23 TC 86 Z9 87 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 JUN PY 2001 VL 63 IS 6 AR 064903 DI 10.1103/PhysRevC.63.064903 PG 7 WC Physics, Nuclear SC Physics GA 440NX UT WOS:000169182200044 ER PT J AU Staszel, P Majka, Z Sobotka, LG Sarantites, DG Charity, RJ Cibor, J Hagel, K Marie, N Natowitz, JB Wada, R Stracener, DW Auger, G Schutz, Y Wieleczko, JP Dayras, R Plagnol, E Barreto, J Norbeck, E AF Staszel, P Majka, Z Sobotka, LG Sarantites, DG Charity, RJ Cibor, J Hagel, K Marie, N Natowitz, JB Wada, R Stracener, DW Auger, G Schutz, Y Wieleczko, JP Dayras, R Plagnol, E Barreto, J Norbeck, E TI Fragment excitation energies at freeze-out in Kr-84+Nb-93 collisions at 45 MeV/nucleon SO PHYSICAL REVIEW C LA English DT Article ID HEAVY-ION COLLISIONS; QUANTUM MOLECULAR-DYNAMICS; NUCLEAR-EQUATION; CHARGED-PARTICLE; HOT NUCLEI; TEMPERATURES; MULTIFRAGMENTATION; EMISSION; STATE; MODEL AB The emission of light charged particles and intermediate-mass fragments (IMF's) from central collisions of 45 MeV/nucleon Kr-84 with Nb-93 has been studied. Violent collisions have been selected using the total collected charge condition. The analysis of the primary IMF excitation energies has been performed for four bins of the detected IMF charge (2< Z(IMF)<20). We find evidence that ia) the mean excitation energy per nucleon for these fragments is independent of fragment charge and approximately equal to 2.5 MeV, (b) the primary fragments at freeze-out preserve the entrance channel (combined system) N/Z ratio, and (c) the freeze-out volume itself is far from spherical. C1 H Niewodniczanski Inst Nucl Phys, PL-31342 Krakow, Poland. Jagiellonian Univ, M Smoluchowski Inst Phys, PL-30059 Krakow, Poland. Washington Univ, Dept Chem, St Louis, MO 63130 USA. Texas A&M Univ, Inst Cyclotron, College Stn, TX 77843 USA. Oak Ridge Natl Lab, Oak Ridge, TN 37830 USA. GANIL, F-14021 Caen, France. Serv Phys Nucl Basse Energy, F-91191 Gif Sur Yvette, France. Inst Phys Nucl, CNRS, IN2P3, F-91406 Orsay, France. Univ Fed Rio de Janeiro, Inst Fis, BR-21945 Rio De Janeiro, Brazil. Univ Iowa, Dept Phys, Iowa City, IA 52242 USA. RP Staszel, P (reprint author), Niels Bohr Inst, Blegdamsvej 17, DK-2100 Copenhagen, Denmark. RI Natowitz, Joseph/D-4160-2015 NR 36 TC 8 Z9 8 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2813 J9 PHYS REV C JI Phys. Rev. C PD JUN PY 2001 VL 63 IS 6 AR 064610 DI 10.1103/PhysRevC.63.064610 PG 13 WC Physics, Nuclear SC Physics GA 440NX UT WOS:000169182200041 ER PT J AU Svensson, CE Macchiavelli, AO Juodagalvis, A Poves, A Ragnarsson, I Aberg, S Appelbe, DE Austin, RAE Ball, GC Carpenter, MP Caurier, E Clark, RM Cromaz, M Deleplanque, MA Diamond, RM Fallon, P Janssens, RVF Lane, GJ Lee, IY Nowacki, F Sarantites, DG Stephens, FS Vetter, K Ward, D AF Svensson, CE Macchiavelli, AO Juodagalvis, A Poves, A Ragnarsson, I Aberg, S Appelbe, DE Austin, RAE Ball, GC Carpenter, MP Caurier, E Clark, RM Cromaz, M Deleplanque, MA Diamond, RM Fallon, P Janssens, RVF Lane, GJ Lee, IY Nowacki, F Sarantites, DG Stephens, FS Vetter, K Ward, D TI Lifetimes of superdeformed rotational states in Ar-36 SO PHYSICAL REVIEW C LA English DT Article ID SHELL-MODEL DESCRIPTION; HIGH-SPIN; PHASE-TRANSITION; DEFORMED-NUCLEI; BANDS; CR-48; DECAY; SPECTROSCOPY; GAMMASPHERE; MECHANISM AB Lifetimes have been measured in a superdeformed rotational band recently identified in the N=Z nucleus Ar-36. A large low-spin quadrupole deformation (beta (2) = 0.46 +/- 0.03) is confirmed and a decrease in the collectivity is observed as the high-spin band termination at I-pi = 16(+) is approached. Detailed comparisons of the experimental B(E2) values with the results of cranked Nilsson-Strutinsky and large-scale (s(1/2)d(3/2))-pf spherical shell model calculations indicate the need for a more refined treatment of transition matrix elements close to termination in the former, and the inclusion of the complete sd-pf model space in the latter description of this highly-collective rotational band. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Div Nucl Sci, Berkeley, CA 94720 USA. Univ Guelph, Dept Phys, Guelph, ON N1G 2W1, Canada. Lund Inst Technol, Dept Math Phys, S-22100 Lund, Sweden. Univ Autonoma Madrid, Dept Fis Teor, E-28049 Madrid, Spain. McMaster Univ, Dept Phys & Astron, Hamilton, ON L8S 4M1, Canada. TRIUMF, Vancouver, BC V6T 2A3, Canada. Argonne Natl Lab, Argonne, IL 60439 USA. Univ Strasbourg, CNRS, IN2P3, Inst Rech Subatom, F-67037 Strasbourg, France. Univ Strasbourg, Phys Theor Lab, F-67084 Strasbourg, France. Washington Univ, Dept Chem, St Louis, MO 63130 USA. RP Univ Calif Berkeley, Lawrence Berkeley Lab, Div Nucl Sci, 1 Cyclotron Rd, Berkeley, CA 94720 USA. RI Lane, Gregory/A-7570-2011; Poves, Alfredo/L-2594-2013; Carpenter, Michael/E-4287-2015 OI Lane, Gregory/0000-0003-2244-182X; Poves, Alfredo/0000-0001-7539-388X; Carpenter, Michael/0000-0002-3237-5734 NR 38 TC 74 Z9 74 U1 0 U2 1 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 JUN PY 2001 VL 63 IS 6 AR 061301 DI 10.1103/PhysRevC.63.061301 PG 5 WC Physics, Nuclear SC Physics GA 440NX UT WOS:000169182200001 ER PT J AU Wells, SP Averett, T Barkhuff, D Beck, DH Beise, EJ Benson, C Breuer, H Carr, R Covrig, S DelCorso, J Dodson, G Eppstein, C Farkhondeh, M Fillippone, BW Forest, TA Frasier, P Hasty, R Ito, TM Jones, C Korsch, W Kowalski, S Lee, P Maneva, E McCarty, K McKeown, RD Mikell, J Mueller, B Naik, P Pitt, ML Ritter, J Savu, V Spayde, DT Sullivan, M Tieulent, R Tsentalovich, E Yang, B Zwart, T AF Wells, SP Averett, T Barkhuff, D Beck, DH Beise, EJ Benson, C Breuer, H Carr, R Covrig, S DelCorso, J Dodson, G Eppstein, C Farkhondeh, M Fillippone, BW Forest, TA Frasier, P Hasty, R Ito, TM Jones, C Korsch, W Kowalski, S Lee, P Maneva, E McCarty, K McKeown, RD Mikell, J Mueller, B Naik, P Pitt, ML Ritter, J Savu, V Spayde, DT Sullivan, M Tieulent, R Tsentalovich, E Yang, B Zwart, T TI Measurement of the vector analyzing power in elastic electron-proton scattering as a probe of the double virtual Compton amplitude SO PHYSICAL REVIEW C LA English DT Article ID MAGNETIC FORM-FACTOR; PARITY VIOLATION; POLARIZATION AB We report the first measurement of the vector analyzing power in inclusive transversely polarized elastic electron-proton scattering at Q(2) = 0.1 (GeV/c)(2) and large scattering angles. This quantity must vanish in the single virtual photon exchange, plane-wave impulse approximation for this reaction, and can therefore provide information on two photon exchange amplitudes for electromagnetic interactions with hadronic systems. The observable we have measured is driven by the imaginary part of the two photon exchange amplitude, the hadronic side of which is simply the Compton amplitude for the proton with two virtual photons. We find a small but nonzero value of A = -15.4 +/- 5.4 ppm. C1 Louisiana Tech Univ, Ctr Appl Phys Studies, Ruston, LA 71272 USA. Coll William & Mary, Dept Phys, Williamsburg, VA 23187 USA. MIT, Nucl Sci Lab, Bates Linear Accelerator Ctr, Cambridge, MA 02139 USA. MIT, Dept Phys, Cambridge, MA 02139 USA. Univ Illinois, Urbana, IL 61801 USA. Univ Maryland, College Pk, MD 20742 USA. CALTECH, Kellogg Radiat Lab, Pasadena, CA 91125 USA. Virginia Polytech Inst & State Univ, Dept Phys, Blacksburg, VA 24061 USA. Univ Kentucky, Dept Phys & Astron, Lexington, KY 40506 USA. Argonne Natl Lab, Div Phys, Argonne, IL 60439 USA. RP Wells, SP (reprint author), Louisiana Tech Univ, Ctr Appl Phys Studies, Ruston, LA 71272 USA. RI Maneva, Elitza/A-7890-2008; Savu, Veronica/C-6069-2009; Averett, Todd/A-2969-2011; Lee, Patricia/B-6146-2012; Maneva, Elitza/E-9215-2013 OI Maneva, Elitza/0000-0002-8638-1013 NR 17 TC 69 Z9 69 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 JUN PY 2001 VL 63 IS 6 AR 064001 DI 10.1103/PhysRevC.63.064001 PG 5 WC Physics, Nuclear SC Physics GA 440NX UT WOS:000169182200012 ER PT J AU Auerbach, LB Burman, RL Caldwell, DO Church, ED Donahue, JB Fazely, A Garvey, GT Gunasingha, RM Imlay, R Louis, WC Majkic, R Malik, A Metcalf, W Mills, GB Sandberg, V Smith, D Stancu, I Sung, M Tayloe, R VanDalen, GJ Vernon, W Wadia, N White, DH Yellin, S AF Auerbach, LB Burman, RL Caldwell, DO Church, ED Donahue, JB Fazely, A Garvey, GT Gunasingha, RM Imlay, R Louis, WC Majkic, R Malik, A Metcalf, W Mills, GB Sandberg, V Smith, D Stancu, I Sung, M Tayloe, R VanDalen, GJ Vernon, W Wadia, N White, DH Yellin, S CA LSND Collaboration TI Measurement of electron-neutrino electron elastic scattering SO PHYSICAL REVIEW D LA English DT Article ID MISSING ENERGY; E(+)E(-) COLLISIONS; MULTIPHOTON EVENTS; LSND EXPERIMENT; MUON-NEUTRINOS; OSCILLATIONS; INTERFERENCE; PARAMETERS; DETECTOR; CURRENTS AB The cross section for the elastic scattering reaction nu (e)+e(-)-->nu (e)+e(-) was measured by the Liquid Scintillator Neutrino Detector using a mu (+) decay-at-rest nu (e) beam at the Los Alamos Neutron Science Center. The standard model of electroweak physics predicts a large destructive interference between the charge current and neutral current channels for this reaction. The measured cross section, sigma (nu ee)-=[10.1+/-1.1(stat) +/-1.0(syst)]x E-nue (MeV)x 10(-45) cm(2), agrees well with standard model expectations. The measured value of the interference parameter, I = -1.01+/-0.13(stat)+/- 0.12(syst), is in good agreement with the standard model expectation of I-SM = - 1.09. Limits are placed on neutrino flavor-changing neutral currents. An upper limit on the muon-neutrino magnetic moment of 6.8 x 10(-10) mu (Bohr) is obtained using the nu (mu) and <()over bar>(mu) fluxes from pi (+) and mu (+) decay. C1 Temple Univ, Philadelphia, PA 19122 USA. Univ Calif Riverside, Riverside, CA 92521 USA. Univ Calif San Diego, La Jolla, CA 92093 USA. Univ Calif Santa Barbara, Santa Barbara, CA 93106 USA. Embry Riddle Aeronaut Univ, Prescott, AZ 86301 USA. Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Louisiana State Univ, Baton Rouge, LA 70803 USA. So Univ, Baton Rouge, LA 70813 USA. RP Temple Univ, Philadelphia, PA 19122 USA. OI Louis, William/0000-0002-7579-3709 NR 45 TC 113 Z9 114 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 JUN 1 PY 2001 VL 63 IS 11 AR 112001 DI 10.1103/PhysRevD.63.112001 PG 11 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 438AM UT WOS:000169031600005 ER PT J AU Barger, V Geer, S Raja, R Whisnant, K AF Barger, V Geer, S Raja, R Whisnant, K TI Exploring neutrino oscillations with superbeams SO PHYSICAL REVIEW D LA English DT Review ID LONG-BASE-LINE; MUON STORAGE-RING; GEV ENERGY-RANGE; ATMOSPHERIC NEUTRINOS; CP-VIOLATION; T-VIOLATION; KAMIOKANDE DETECTOR; STERILE-NEUTRINO; LSND EXPERIMENT; MASS MATRICES AB We consider the medium- and long-baseline oscillation physics capabilities of intense muon-neutrino and muon-antineutrino beams produced using future upgraded megawatt-scale high-energy proton beams. In particular we consider the potential of these conventional neutrino "superbeams" for observing nu (mu)-->nu (e) oscillations, determining the hierarchy of neutrino mass eigenstates, and measuring CP Violation in the lepton sector. The physics capabilities of superbeams are explored as a function of the beam energy, baseline, and the detector parameters (fiducial mass, background rarest and systematic uncertainties on the backgrounds). The trade-offs between very large detectors with poor background rejection and smaller detectors with excellent background rejection are illustrated. We find that, with an aggressive set of detector parameters, it may be possible, to observe nu (mu)-->nu (e) oscillations with a superbeam provided that the amplitude parameter sin(2)2 theta (13) is larger than a few x 10(-3). If sin(2)2 theta (13) is of order 10(-2) or larger, then the neutrino mass hierarchy can be determined in long-baseline experiments, and if in addition the large mixing angle MSW solution describes the solar neutrino deficit, then there is a small region of parameter space within which maximal CP violation in the lepton sector would be observable (with a significance of a few standard deviations) in a low-energy medium-baseline experiment. We illustrate our results by explicitly considering massive water Cherenkov and liquid argon detectors at superbeams with neutrino energies ranging from 1 GeV to 15 GeV, and baselines ranging from 295 km to 9300 km. Finally, we compare the oscillation physics prospects at superbeams with the corresponding prospects at neutrino factories. The sensitivity at a neutrino factory to CP violation and the neutrino mass hierarchy extends to values of the amplitude parameter sin(2)2 theta (13) that are one to two orders of magnitude lower than at a superbeam. C1 Univ Wisconsin, Dept Phys, Madison, WI 53706 USA. Fermilab Natl Accelerator Lab, Batavia, IL 60510 USA. Iowa State Univ, Dept Phys & Astron, Ames, IA 50011 USA. RP Univ Wisconsin, Dept Phys, 1150 Univ Ave, Madison, WI 53706 USA. NR 139 TC 62 Z9 62 U1 0 U2 2 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 2470-0010 EI 2470-0029 J9 PHYS REV D JI Phys. Rev. D PD JUN 1 PY 2001 VL 63 IS 11 AR 113011 DI 10.1103/PhysRevD.63.113011 PG 24 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 438AM UT WOS:000169031600018 ER PT J AU Berger, EL Harris, BW Sullivan, Z AF Berger, EL Harris, BW Sullivan, Z TI Direct probes of R-parity-violating supersymmetric couplings via single-top-squark production SO PHYSICAL REVIEW D LA English DT Article ID HADRON-COLLISIONS; STOP PRODUCTION; COLLIDERS; SUPERGRAVITY; PHYSICS; MODELS; LEP AB We study the s-channel production of a single top squark in hadron collisions through an R-parity-violating mechanism, examining in detail the case in which the squark decays through an R-parity-conserving process into a bottom quark a lepton, and missing energy. We show that the top squark can be discovered if its mass is less than 400 GeV, or that the current bound on the size of the R-parity-violating couplings can be reduced by up to one order of magnitude with existing data and by two orders of magnitude at the forthcoming run II of the Fermilab Tevatron. C1 Argonne Natl Lab, Div High Energy Phys, Argonne, IL 60439 USA. RP Berger, EL (reprint author), Argonne Natl Lab, Div High Energy Phys, Argonne, IL 60439 USA. NR 31 TC 33 Z9 33 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 JUN 1 PY 2001 VL 63 IS 11 AR 115001 DI 10.1103/PhysRevD.63.115001 PG 12 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 438AM UT WOS:000169031600059 ER PT J AU Burdman, G Hiller, G AF Burdman, G Hiller, G TI Semileptonic form factors from B -> K*gamma decays in the large energy limit SO PHYSICAL REVIEW D LA English DT Article ID HEAVY MESON DECAYS; QUARK-MODEL; B-DECAY; QCD; UPDATE AB Making use of the measurement of the B-->K*gamma branching ratio together with the relations following from the limit of high recoil energy, we obtain stringent constraints on the values of the form factors entering in heavy-to-light B-->Vll' processes such as B-->K*l(+)l(-), B-->K*nu<()over bar> and B-->rhol nu decays. We show that the symmetry predictions, when combined with the experimental information on radiative decays, specify a severely restricted set of values for the vector and axial-vector form factors evaluated at zero momentum transfer, q(2)=0. These constraints can be used to test model calculations and to improve our understanding of the q(2) dependence of semileptonic form factors. We stress that the constraints remain stringent even when corrections are taken into account. C1 Boston Univ, Dept Phys, Boston, MA 02215 USA. Stanford Univ, Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. RP Burdman, G (reprint author), Boston Univ, Dept Phys, 590 Commonwealth Ave, Boston, MA 02215 USA. EM burdman@bu.edu; ghiller@slac.stanford.edu RI Burdman, Gustavo/D-3285-2012 NR 30 TC 42 Z9 42 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2821 J9 PHYS REV D JI Phys. Rev. D PD JUN 1 PY 2001 VL 63 IS 11 AR 113008 DI 10.1103/PhysRevD.63.113008 PG 5 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 438AM UT WOS:000169031600015 ER PT J AU Carlson, CE Hanlon, J Lassila, KE AF Carlson, CE Hanlon, J Lassila, KE TI Experimental and theoretical results for weak charge current backward proton production SO PHYSICAL REVIEW D LA English DT Article ID SPIN STRUCTURE; DEUTERON; SCATTERING; NUCLEI; DISTRIBUTIONS; LEPTON; MODEL AB In this paper, we study deuteron breakup by high energy neutrinos. We present previously unpublished data on neutrino induced backward protons from deuteron targets; we calculate the contributions from both the two-nucleon (2N) and six-quark (6q) deuteron components, which depend upon the overall normalization of the part that is 6q; and, we suggest other signatures for distinguishing the 2N and 6q clusters. We conclude that the 6q cluster naturally contributes to the high momentum backward proton spectrum just in the region where the standard 2N models lie below the data, and the absolute size of the far backward data is nicely explained if the amount of 6q is one or a few percent by normalization of the deuteron. C1 Coll William & Mary, Dept Phys, Williamsburg, VA 23187 USA. Fermilab Natl Accelerator Lab, Batavia, IL 60510 USA. Iowa State Univ, Dept Phys & Astron, Ames, IA 50011 USA. RP Coll William & Mary, Dept Phys, Williamsburg, VA 23187 USA. NR 30 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 JUN 1 PY 2001 VL 63 IS 11 AR 117301 DI 10.1103/PhysRevD.63.117301 PG 4 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 438AM UT WOS:000169031600081 ER PT J AU Chan, S Eigen, G Lipeles, E Miller, JS Schmidtler, M Shapiro, A Sun, WM Urheim, J Weinstein, AJ Wurthwein, F Jaffe, DE Masek, G Paar, HP Potter, EM Prell, S Sharma, V Asner, DM Eppich, A Gronberg, J Hill, TS Lange, DJ Morrison, RJ Nelson, HN Nelson, TK Roberts, D Behrens, BH Ford, WT Gritsan, A Krieg, H Roy, J Smith, JG Alexander, JP Baker, R Bebek, C Berger, BE Berkelman, K Boisvert, V Cassel, DG Crowcroft, DS Dickson, M von Dombrowski, S Drell, PS Ecklund, KM Ehrlich, R Foland, AD Gaidarev, P Gibbons, L Gittelman, B Gray, SW Hartill, DL Heltsley, BK Hopman, PI Kreinick, DL Lee, T Liu, Y Mistry, NB Ng, CR Nordberg, E Ogg, M Patterson, JR Peterson, D Riley, D Soffer, A Valant-Spaight, B Warburton, A Ward, C Athanas, M Avery, P Jones, CD Lohner, M Prescott, C Rubiera, AI Yelton, J Zheng, J Brandenburg, G Briere, RA 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 Selen, M Thaler, JJ Edwards, KW Bellerive, A Janicek, R Patel, PM Sadoff, AJ Ammar, R Baringer, P Bean, A Besson, D Coppage, D Davis, R Kotov, S Kravchenko, I Kwak, N Zhou, L Anderson, S Kubota, Y Lee, SJ Mahapatra, R O'Neill, JJ Poling, R Riehle, T Smith, A Alam, MS Athar, SB Ling, Z Mahmood, AH Timm, S Wappler, F Anastassov, A Duboscq, JE Gan, KK Gwon, C Hart, T Honscheid, K Kagan, H Kass, R Lee, J Lorenc, J Schwarthoff, H Wolf, A Zoeller, MM Richichi, SJ Severini, H Skubic, P Undrus, A Bishai, M Chen, S Fast, J Hinson, JW Menon, N Miller, DH Shibata, EI Shipsey, IPJ Glenn, S Kwon, Y Lyon, AL Roberts, S Thorndike, EH Jessop, CP Lingel, K Marsiske, H Perl, ML Savinov, V Ugolini, D Zhou, X Coan, TE Fadeyev, V Korolkov, I Maravin, Y Narsky, I Stroynowski, R Ye, J Wlodek, T Artuso, M Dambasuren, E Kopp, S Moneti, GC Mountain, R Schuh, S Skwarnicki, T Stone, S Titov, A Viehhauser, G Wang, JC Csorna, SE McLean, KW Marka, S Xu, Z Godang, R Kinoshita, K Lai, IC Pomianowski, P Schrenk, S Bonvicini, G Cinabro, D Greene, R Perera, LP Zhou, GJ AF Chan, S Eigen, G Lipeles, E Miller, JS Schmidtler, M Shapiro, A Sun, WM Urheim, J Weinstein, AJ Wurthwein, F Jaffe, DE Masek, G Paar, HP Potter, EM Prell, S Sharma, V Asner, DM Eppich, A Gronberg, J Hill, TS Lange, DJ Morrison, RJ Nelson, HN Nelson, TK Roberts, D Behrens, BH Ford, WT Gritsan, A Krieg, H Roy, J Smith, JG Alexander, JP Baker, R Bebek, C Berger, BE Berkelman, K Boisvert, V Cassel, DG Crowcroft, DS Dickson, M von Dombrowski, S Drell, PS Ecklund, KM Ehrlich, R Foland, AD Gaidarev, P Gibbons, L Gittelman, B Gray, SW Hartill, DL Heltsley, BK Hopman, PI Kreinick, DL Lee, T Liu, Y Mistry, NB Ng, CR Nordberg, E Ogg, M Patterson, JR Peterson, D Riley, D Soffer, A Valant-Spaight, B Warburton, A Ward, C Athanas, M Avery, P Jones, CD Lohner, M Prescott, C Rubiera, AI Yelton, J Zheng, J Brandenburg, G Briere, RA 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 Selen, M Thaler, JJ Edwards, KW Bellerive, A Janicek, R Patel, PM Sadoff, AJ Ammar, R Baringer, P Bean, A Besson, D Coppage, D Davis, R Kotov, S Kravchenko, I Kwak, N Zhou, L Anderson, S Kubota, Y Lee, SJ Mahapatra, R O'Neill, JJ Poling, R Riehle, T Smith, A Alam, MS Athar, SB Ling, Z Mahmood, AH Timm, S Wappler, F Anastassov, A Duboscq, JE Gan, KK Gwon, C Hart, T Honscheid, K Kagan, H Kass, R Lee, J Lorenc, J Schwarthoff, H Wolf, A Zoeller, MM Richichi, SJ Severini, H Skubic, P Undrus, A Bishai, M Chen, S Fast, J Hinson, JW Menon, N Miller, DH Shibata, EI Shipsey, IPJ Glenn, S Kwon, Y Lyon, AL Roberts, S Thorndike, EH Jessop, CP Lingel, K Marsiske, H Perl, ML Savinov, V Ugolini, D Zhou, X Coan, TE Fadeyev, V Korolkov, I Maravin, Y Narsky, I Stroynowski, R Ye, J Wlodek, T Artuso, M Dambasuren, E Kopp, S Moneti, GC Mountain, R Schuh, S Skwarnicki, T Stone, S Titov, A Viehhauser, G Wang, JC Csorna, SE McLean, KW Marka, S Xu, Z Godang, R Kinoshita, K Lai, IC Pomianowski, P Schrenk, S Bonvicini, G Cinabro, D Greene, R Perera, LP Zhou, GJ CA CLEO Collaboration TI Measurement of the decay asymmetry parameters in Xi(0)(c)->Xi(-)pi(+) SO PHYSICAL REVIEW D LA English DT Article ID NONLEPTONIC WEAK DECAYS; CHARMED BARYONS; QUARK AB Using the CLEO II detector at the Cornell Electron Storage Ring we have measured the Xi (0)(c) decay asymmetry parameter in the decay Xi (0)(c) --> Xi (-)pi (+). We find alpha (o)(Xi)alpha (Xi)= 0.26+/- 0.18(stat)(-0.04)(+0.05)(syst); using the world average value of alpha (Xi)= - 0.456+/-0.014 we obtain alpha (o)(Xic)= - 0.56 +/- 0.39(stat)(-0.09)(+0.10)(syst). The physically allowed rang of a decay asymmetry parameter is - 1 << + 1. Our result prefers a negative value: Xi (0)(c) is <0.1 at the 90% C.L. The central value occupies the middle of the theoretically expected range but is not yet precise enough to choose between models. C1 CALTECH, Pasadena, CA 91125 USA. Univ Calif San Diego, La Jolla, CA 92093 USA. Univ Calif Santa Barbara, Santa Barbara, CA 93106 USA. Univ Colorado, Boulder, CO 80309 USA. Cornell Univ, Ithaca, NY 14853 USA. Univ Florida, Gainesville, FL 32611 USA. Harvard Univ, Cambridge, MA 02138 USA. Univ Hawaii Manoa, Honolulu, HI 96822 USA. Univ Illinois, Urbana, IL 61801 USA. Carleton Univ, Ottawa, ON K1S 5B6, Canada. Inst Particle Phys, Ottawa, ON, Canada. McGill Univ, Montreal, PQ H3A 2T8, Canada. Ithaca Coll, Ithaca, NY 14850 USA. Univ Minnesota, Minneapolis, MN 55455 USA. SUNY Albany, Albany, NY 12222 USA. Ohio State Univ, Columbus, OH 43210 USA. Univ Kansas, Lawrence, KS 66045 USA. Univ Oklahoma, Norman, OK 73019 USA. Purdue Univ, W Lafayette, IN 47907 USA. Univ Rochester, Rochester, NY 14627 USA. Stanford Univ, Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. So Methodist Univ, Dallas, TX 75275 USA. Syracuse Univ, Syracuse, NY 13244 USA. Vanderbilt Univ, Nashville, TN 37235 USA. Virginia Polytech Inst & State Univ, Blacksburg, VA 24061 USA. Wayne State Univ, Detroit, MI 48202 USA. Univ Texas, Austin, TX 78712 USA. Carnegie Mellon Univ, Pittsburgh, PA 15213 USA. Yonsei Univ, Seoul 120749, South Korea. Univ Cincinnati, Cincinnati, OH 45221 USA. RP Chan, S (reprint author), CALTECH, Pasadena, CA 91125 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 20 TC 1 Z9 1 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 JUN 1 PY 2001 VL 63 IS 11 AR 111102 PG 6 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 438AM UT WOS:000169031600002 ER PT J AU Duncan, A Eichten, E Thacker, H AF Duncan, A Eichten, E Thacker, H TI String breaking in four dimensional lattice QCD SO PHYSICAL REVIEW D LA English DT Article ID MATTER FIELDS AB Virtual quark pair screening leads to breaking of the string between fundamental representation quarks in QCD. For unquenched four dimensional lattice QCD, this (so far elusive) phenomenon is studied using the recently developed truncated determinant algorithm (TDA). The dynamical configurations were generated on a 650 MHz PC. Quark eigenmodes up to 420 MeV are included exactly in these TDA studies performed at low quark mass on large coarse [but O(a(2)) improved] lattices. A study of Wilson line correlators in Coulomb gauge extracted from an ensemble of 1000 two-flavor dynamical configurations reveals evidence for flattening of the string tension at distances R greater than or similar to1 fm. C1 Univ Pittsburgh, Dept Phys & Astron, Pittsburgh, PA 15260 USA. Fermilab, Batavia, IL 60510 USA. Univ Virginia, Dept Phys, Charlottesville, VA 22901 USA. RP Duncan, A (reprint author), Univ Pittsburgh, Dept Phys & Astron, Pittsburgh, PA 15260 USA. NR 16 TC 22 Z9 22 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2821 J9 PHYS REV D JI Phys. Rev. D PD JUN 1 PY 2001 VL 63 IS 11 AR 111501 DI 10.1103/PhysRevD.63.111501 PG 5 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 438AM UT WOS:000169031600004 ER PT J AU Dunietz, I Fleischer, R Nierste, U AF Dunietz, I Fleischer, R Nierste, U TI In pursuit of new physics with B-s decays SO PHYSICAL REVIEW D LA English DT Article ID EXTRACTING CKM PHASES; CP-VIOLATION; ANGULAR-DISTRIBUTIONS; WIDTH DIFFERENCE; MESON DECAYS; B-S(0)-(B)OVER-BAR(S)(0) SYSTEM; B-S->J/PSI-PHI DECAYS; DISCRETE AMBIGUITIES; SEMILEPTONIC DECAYS; LIFETIME DIFFERENCE AB The presence of a sizable CP-violating phase in B-s-(B) over bar (s) mixing would be an unambiguous signal of physics beyond the standard model. We analyze various possibilities to detect such a new phase considering both tagged and untagged decays. The effects of a sizable width difference Delta Gamma between the B-s mass eignstates, on which the untagged analyses rely, are included in all formulas. A novel method to find this phase from simple measurements of lifetimes and branching ratios in untagged decays is proposed. This method does not involve two-exponential fits, which require much larger statistics. For the tagged decays, an outstanding role is played by the observables of the time-dependent angular distribution of the B-s-->J/psi[-->l(+)l(-)]phi[-->K+K-] decay products. We list the formulas needed for the angular analysis in the presence of both a new CP-violating phase and a sizable Delta Gamma, and propose methods to remove a remaining discrete ambiguity in the new phase. This phase can therefore be determined in an unambiguous way. C1 Fermi Natl Accelerator Lab, Batavia, IL 60510 USA. DESY, D-22607 Hamburg, Germany. CERN, Div Theory, CH-1211 Geneva, Switzerland. RP Dunietz, I (reprint author), Fermi Natl Accelerator Lab, POB 500, Batavia, IL 60510 USA. EM dunietz@fnal.gov; Robert.Fleischer@desy.de; Ulrich.Nierste@cern.ch NR 72 TC 160 Z9 160 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 JUN 1 PY 2001 VL 63 IS 11 AR 114015 DI 10.1103/PhysRevD.63.114015 PG 16 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 438AM UT WOS:000169031600041 ER PT J AU Hinchliffe, I Kersting, N AF Hinchliffe, I Kersting, N TI Flavor alignment supersymmetric grand unified theories SO PHYSICAL REVIEW D LA English DT Article ID PARTICLE PHYSICS; DOUBLE-BETA; MODEL; CONSERVATION; OSCILLATIONS; UNIFICATION; DECAYS; NUMBER; MASS AB A supersymmetric grand unified model is constructed based on SO(10)x SO(10) symmetry in which new types of Yukawa matrices couple standard and exotic fermions. The evolution of these couplings from the grand unified scale to the electroweak scale causes some of them to be driven to their fixed points. This solves the supersymmetric alignment problem and ensures that there are no observable flavor changing neutral currents mediated by supersymmetric particles. Fermion hierarchy and neutrino mixing constraints are automatically satisfied in this formalism. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. NR 34 TC 0 Z9 0 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 JUN 1 PY 2001 VL 63 IS 11 AR 115008 PG 12 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 438AM UT WOS:000169031600066 ER PT J AU Hinchliffe, I Paige, FE AF Hinchliffe, I Paige, FE TI Lepton flavor violations at the CERN LHC SO PHYSICAL REVIEW D LA English DT Article ID GRAND UNIFICATION; SUPER-KAMIOKANDE; STANDARD MODEL; NEUTRINO; SUPERGRAVITY; SUPERSYMMETRY; PHYSICS; FLUX AB Recent results from Super Kamiokande suggest nu (mu)-nu (tau) mixing and hence lepton flavor violation. In supersymmetric models, this flavor violation may have implications for the pattern of slepton masses and mixings. Possible signals for this mixing in the decays of sleptons produced at the CERN LHC are discussed. The sensitivity expected is compared to that of rare decays such as tau --> mu gamma. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. Brookhaven Natl Lab, Upton, NY 11973 USA. RP Hinchliffe, I (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. NR 31 TC 61 Z9 61 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 JUN 1 PY 2001 VL 63 IS 11 AR 115006 DI 10.1103/PhysRevD.63.115006 PG 8 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 438AM UT WOS:000169031600064 ER PT J AU Jadach, S Ward, BFL Was, Z AF Jadach, S Ward, BFL Was, Z TI Coherent exclusive exponentiation for precision Monte Carlo calculations SO PHYSICAL REVIEW D LA English DT Article ID FERMION-PAIR PRODUCTION; (UN)STABLE W+W PRODUCTION; RADIATIVE-CORRECTIONS; BHABHA SCATTERING; GAUGE-THEORIES; MULTIPLE BREMSSTRAHLUNG; STANDARD MODEL; CROSS-SECTION; SINGLE BREMSSTRAHLUNG; E(+)E(-) COLLISIONS AB We present the new coherent exclusive exponentiation (CEEX), the older exclusive exponentiation (EEX), and the semianalytical inclusive exponentiation (IEX) for the process e(-)e(+)-->f (f) over bar +n gamma, where f = mu, tau ,d,u,s,c,b, which are valid for center-of-mass energies from the tau lepton threshold to 1 TeV, that is, for CERN LEP1, LEP2, the SLC, future linear colliders, and b,c,tau factories, etc. The approaches are based on Yennie-Frautschi-Suura exponentiation. In CEEX, the effects due to photon emission from initial beams and outgoing fermions are calculated in QED up to second order, including all interference effects. Electroweak corrections are included to first order, at the amplitude level. Beams can be polarized longitudinally and transversely, and all spin correlations are incorporated in an exact manner. The EEX is more primitive, lacks initial-final interferences, but it is valuable for testing the newer CEEX. The IEX provides us with a set of sophisticated semianalytical formulas for the total cross section and selected inclusive distributions, which are mainly used for cross-checks of the Monte Carlo results. We analyze numerical results at the Z peak, 189 GeV and 500 GeV for simple kinematical cuts (comparisons with inclusive exponentiation) and for realistic experimental cuts. The physical precision and technical precision are determined for the total cross section and for the charge asymmetry. C1 Univ Tennessee, Dept Phys & Astron, Knoxville, TN 37996 USA. Inst Nucl Phys, PL-30055 Krakow, Poland. Stanford Univ, Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. CERN, Div Theory, CH-1211 Geneva 23, Switzerland. RP Jadach, S (reprint author), Univ Tennessee, Dept Phys & Astron, Knoxville, TN 37996 USA. NR 70 TC 219 Z9 222 U1 1 U2 2 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 JUN 1 PY 2001 VL 63 IS 11 AR 113009 DI 10.1103/PhysRevD.63.113009 PG 65 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 438AM UT WOS:000169031600016 ER PT J AU Khan, AA Aoki, S Aoki, Y Burkhalter, R Ejiri, S Fukugita, M Hashimoto, S Ishizuka, N Iwasaki, Y Izubuchi, T Kanaya, K Kaneko, T Kuramashi, Y Manke, T Nagai, KI Noaki, J Okawa, M Shanahan, HP Taniguchi, Y Ukawa, A Yoshie, T AF Khan, AA Aoki, S Aoki, Y Burkhalter, R Ejiri, S Fukugita, M Hashimoto, S Ishizuka, N Iwasaki, Y Izubuchi, T Kanaya, K Kaneko, T Kuramashi, Y Manke, T Nagai, KI Noaki, J Okawa, M Shanahan, HP Taniguchi, Y Ukawa, A Yoshie, T CA CP-PACS Collaboration TI Chiral properties of domain-wall quarks in quenched QCD SO PHYSICAL REVIEW D LA English DT Article ID EXACTLY MASSLESS QUARKS; LATTICE QCD; WILSON FERMIONS; GAUGE-THEORY; DIRAC OPERATOR; U(1) PROBLEM; INSTANTONS; BREAKING; SPECTRUM; MASSES AB We investigate the chiral properties of quenched domain-wall QCD (DWQCD) at the lattice spacings a(-1) similar or equal to 1 and 2 GeV for both plaquette and renormalization-group (RG) improved gauge actions. In the case of the plaquette action we find that the quark mass defined through the axial Ward-Takahashi identity remains non-vanishing in the DWQCD chiral limit that the bare quark mass m(f)-->0 and the length of the fifth dimension N-s--> infinity, indicating that chiral symmetry is not realized with quenched DWQCD up to a(-1) similar or equal to 2 GeV. The behavior is much improved for the RG-improved gauge action: while a nonvanishing quark mass remains in the chiral limit at a(-1) similar or equal to 1 GeV, the result at a(-1) similar or equal to 2 GeV is consistent with an exponentially vanishing quark mass in the DWQCD chiral limit, indicating the realization of exact chiral symmetry. An interpretation and implications are briefly discussed. C1 Univ Tsukuba, Ctr Computat Phys, Tsukuba, Ibaraki 3058577, Japan. Univ Tsukuba, Inst Phys, Tsukuba, Ibaraki 3058570, Japan. Brookhaven Natl Lab, RIKEN BNL Res Ctr, Upton, NY 11973 USA. Univ Tokyo, Inst Cosm Ray Res, Tokyo 1888502, Japan. KEK, High Energy Accelerator Res Org, Tsukuba, Ibaraki 3050801, Japan. Kanazawa Univ, Dept Phys, Kanazawa, Ishikawa 9201192, Japan. Washington Univ, Dept Phys, St Louis, MO 63130 USA. RP Univ Tsukuba, Ctr Computat Phys, Tsukuba, Ibaraki 3058577, Japan. RI Ukawa, Akira/A-6549-2011; Kuramashi, Yoshinobu /C-8637-2016 NR 58 TC 44 Z9 44 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 JUN 1 PY 2001 VL 63 IS 11 AR 114504 DI 10.1103/PhysRevD.63.114504 PG 19 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 438AM UT WOS:000169031600058 ER PT J AU Laenen, E Sterman, G Vogelsang, W AF Laenen, E Sterman, G Vogelsang, W TI Recoil and threshold corrections in short-distance cross sections SO PHYSICAL REVIEW D LA English DT Article ID DIRECT-PHOTON PRODUCTION; SMALL TRANSVERSE-MOMENTUM; TO-LEADING-ORDER; DRELL-YAN PROCESS; HADRON-HADRON SCATTERING; SOFT-GLUON RESUMMATION; HEAVY-QUARK PRODUCTION; QCD HARD SCATTERING; LIGHT-CONE GAUGE; PARTON DISTRIBUTIONS AB We identify and resum corrections associated with the kinematic recoil of the hard scattering against soft-gluon emission in single-particle inclusive cross sections. The method avoids double counting and conserves the flow of partonic energy. It reproduces threshold resummation for high-p(T) single-particle cross sections, when recoil is neglected, and Q(T) resummation at low Q(T), when higher-order threshold logarithms are suppressed. We exhibit explicit resummed cross sections, accurate to next-to-leading logarithm, for electroweak annihilation and prompt photon inclusive cross sections. C1 NIKHEF, Theory Grp, NL-1098 SJ Amsterdam, Netherlands. SUNY Stony Brook, Cn Yang Inst Theoret Phys, Stony Brook, NY 11794 USA. Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. Brookhaven Natl Lab, RIKEN BNL, Upton, NY 11973 USA. RP Laenen, E (reprint author), NIKHEF, Theory Grp, Kruislaan 409, NL-1098 SJ Amsterdam, Netherlands. NR 95 TC 91 Z9 91 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2821 J9 PHYS REV D JI Phys. Rev. D PD JUN 1 PY 2001 VL 63 IS 11 AR 114018 DI 10.1103/PhysRevD.63.114018 PG 32 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 438AM UT WOS:000169031600044 ER PT J AU Radyushkin, AV Weiss, C AF Radyushkin, AV Weiss, C TI Deeply virtual Compton scattering amplitude at the dree level: Transversality, twist-3, and factorization SO PHYSICAL REVIEW D LA English DT Article ID HARD EXCLUSIVE ELECTROPRODUCTION; NONFORWARD PARTON DISTRIBUTIONS; LIGHT-CONE OPERATORS; EVOLUTION-EQUATIONS; NUCLEON; DECOMPOSITION; CURRENTS; QCD AB We study the virtual Compton amplitude in the generalized Bjorken region (q(2)-->infinity, t small) in QCD by means of a light-cone expansion of the product of EM currents in string operators in coordinate space. Electromagnetic gauge invariance (transversality) is maintained by including in addition to the twist-2 operators "kinematical" twist-3 operators which appear as total derivatives of twist-2 operators. The non-forward matrix elements of the elementary twist-2 operators are parametrized in terms of two-variable spectral functions (double distributions), from which twist-2 and 3 skewed distributions are obtained through reduction formulas. Our approach is equivalent to a Wandzura-Wilczek-type approximation for the twist-3 skewed distributions. The resulting Compton amplitude is manifestly transverse up to terms of order t/q(2). We find that in this approximation the tensor amplitude for longitudinal polarization of the virtual photon is finite, while the one for transverse polarization contains a divergence already at the tree level. However, this divergence has zero projection on the polarization vector of the final photon, so that the physical helicity amplitudes are finite. C1 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. JINR, Theoret Phys Lab, Dubna, Russia. RP Radyushkin, AV (reprint author), Old Dominion Univ, Dept Phys, Norfolk, VA 23529 USA. EM radyush@jlab.org; weiss@tp2.ruhr-uni-bochum.de NR 42 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 JUN 1 PY 2001 VL 63 IS 11 AR 114012 DI 10.1103/PhysRevD.63.114012 PG 24 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 438AM UT WOS:000169031600038 ER PT J AU Scavenius, O Dumitru, A Fraga, ES Lenaghan, JT Jackson, AD AF Scavenius, O Dumitru, A Fraga, ES Lenaghan, JT Jackson, AD TI First-order chiral phase transition in high-energy collisions: Can nucleation prevent spinodal decomposition? SO PHYSICAL REVIEW D LA English DT Article ID QUARK-GLUON PLASMA; HEAVY-ION COLLISIONS; FINITE-TEMPERATURE; SUPERDENSE MATTER; PION FIELDS; QCD; BUBBLES; POINT; CHROMODYNAMICS; DISTRIBUTIONS AB We discuss homogeneous nucleation in a first-order chiral phase transition within an effective field theory approach to low-energy QCD. Exact decay rates and bubble profiles are obtained numerically and compared to analytic results obtained with the thin-wall approximation. The thin-wall approximation overestimates the nucleation rate for any degree of supercooling. The lime scale for critical thermal fluctuations is calculated and compared to typical expansion times for high-energy hadronic or heavy-ion collisions. We find that significant supercooling is possible, and the relevant mechanism for phase conversion might be that of spinodal decomposition. Some potential experimental signatures of supercooling, such as an increase in the correlation length of the scaler condensate, are also discussed. C1 NORDITA, DK-2100 Copenhagen O, Denmark. Niels Bohr Inst, DK-2100 Copenhagen, Denmark. Columbia Univ, Dept Phys, New York, NY 10027 USA. Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. Yale Univ, Dept Phys, New Haven, CT 06520 USA. RP Scavenius, O (reprint author), NORDITA, Blegdamsvej 17, DK-2100 Copenhagen O, Denmark. RI Fraga, Eduardo/H-6010-2016 OI Fraga, Eduardo/0000-0001-5340-156X NR 65 TC 62 Z9 62 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 JUN 1 PY 2001 VL 63 IS 11 AR 116003 DI 10.1103/PhysRevD.63.116003 PG 10 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 438AM UT WOS:000169031600072 ER PT J AU Burakovsky, L Preston, DL AF Burakovsky, L Preston, DL TI Dislocation-mediated melting: The one-component plasma limit SO PHYSICAL REVIEW E LA English DT Article ID MONTE-CARLO CALCULATIONS; DENSE IONIZED MATTER; STATISTICAL-MECHANICS; EQUILIBRIUM PROPERTIES; FLUID EQUATION; YUKAWA SYSTEMS; SHEAR MODULUS; N-DEPENDENCE; STATE; THERMODYNAMICS AB The melting parameter Gamma (m) of a classical one-component plasma is estimated using a relation between the melting temperature, density, shear modulus, and a crystal coordination number that follows from our model of dislocation-mediated melting. We obtain Gamma (m) = 172 +/- 35, in good agreement with the results of numerous Monte Carlo calculations. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Burakovsky, L (reprint author), Univ Calif Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. EM BURAKOV@LANL.GOV; DEAN@LANL.GOV NR 46 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 1063-651X J9 PHYS REV E JI Phys. Rev. E PD JUN PY 2001 VL 63 IS 6 AR 067402 DI 10.1103/PhysRevE.63.067402 PN 2 PG 4 WC Physics, Fluids & Plasmas; Physics, Mathematical SC Physics GA 442KU UT WOS:000169285300106 PM 11415261 ER PT J AU Fatkullin, I Kladko, K Mitkov, I Bishop, AR AF Fatkullin, I Kladko, K Mitkov, I Bishop, AR TI Anomalous relaxation and self-organization in nonequilibrium processes SO PHYSICAL REVIEW E LA English DT Article ID DYNAMICS AB We study thermal relaxation in ordered arrays of coupled nonlinear elements with external driving. We find that our model exhibits dynamic self-organization manifested in a universal stretched-exponential form of relaxation. We identify two types of self-organization, cooperative and anticooperative. which lead to fast and slow relaxation, respectively. We give a qualitative explanation for the behavior of the stretched exponent in different parameter ranges. We emphasize that this is a system exhibiting stretched-exponential relaxation without explicit disorder or frustration. C1 Rensselaer Polytech Inst, Dept Math Sci, Troy, NY 12180 USA. Stanford Univ, Dept Phys, Stanford, CA 94305 USA. Northeastern Univ, Dept Phys, Boston, MA 02115 USA. Northeastern Univ, CIRCS, Boston, MA 02115 USA. Univ Calif Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. Univ Calif Los Alamos Natl Lab, Ctr Nonlinear Studies, Los Alamos, NM 87545 USA. RP Fatkullin, I (reprint author), Rensselaer Polytech Inst, Dept Math Sci, Troy, NY 12180 USA. NR 27 TC 4 Z9 4 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1063-651X J9 PHYS REV E JI Phys. Rev. E PD JUN PY 2001 VL 63 IS 6 AR 067102 DI 10.1103/PhysRevE.63.067102 PN 2 PG 4 WC Physics, Fluids & Plasmas; Physics, Mathematical SC Physics GA 442KU UT WOS:000169285300101 PM 11415256 ER PT J AU Militzer, B Ceperley, DM AF Militzer, B Ceperley, DM TI Path integral Monte Carlo simulation of the low-density hydrogen plasma SO PHYSICAL REVIEW E LA English DT Article ID MOLECULAR-DYNAMICS; LIQUID DEUTERIUM; STATE; EQUATION; FLUID; DISSOCIATION; IONIZATION; TRANSITION; HUGONIOT AB Restricted path integral Monte Carlo simulations are used to calculate the equilibrium properties of hydrogen in the density and temperature range of 9.83 x 10(-4) less than or equal to rho less than or equal to0.153 g cm(-3) and 5000 less than or equal toT less than or equal to 250 000 K. We test the accuracy of the pair density matrix and analyze the dependence on the system size, on the time step of the path integral, and on the type of nodal surface. We calculate the equation of state and compare with other models for hydrogen valid in this regime. Further, we characterize the state of hydrogen and describe the changes from a plasma to an atomic and molecular liquid by analyzing the pair correlation functions and estimating the number of atoms and molecules present. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. Univ Illinois, Natl Ctr Supercomp Applicat, Dept Phys, Urbana, IL 61801 USA. RP Militzer, B (reprint author), Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. EM militzer@llnl.gov; ceperley@uiuc.edu RI Ceperley, David/A-6858-2008 NR 24 TC 77 Z9 79 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 JUN PY 2001 VL 63 IS 6 AR 066404 DI 10.1103/PhysRevE.63.066404 PN 2 PG 10 WC Physics, Fluids & Plasmas; Physics, Mathematical SC Physics GA 442KU UT WOS:000169285300077 PM 11415232 ER PT J AU Sweet, D Ott, E Finn, JM Antonsen, TM Lathrop, DP AF Sweet, D Ott, E Finn, JM Antonsen, TM Lathrop, DP TI Blowout bifurcations and the onset of magnetic activity in turbulent dynamos SO PHYSICAL REVIEW E LA English DT Article ID RIDDLED BASINS; CHAOTIC FLOWS; INTERMITTENCY; FIELD; TRANSITION; STABILITY; SYSTEMS; MAPS AB The transition to magnetic-field self-generation in a turbulent, electrically conducting fluid is shown to exhibit intermittent bursting characterized by distinct scaling laws. This behavior is predicted on the basis of prior analysis of a type of bifurcation (called a blowout bifurcation) occurring in chaotic systems with an invariant phase space submanifold. The predicted scalings are shown to be consistent with numerical solutions of the governing magnetohydrodynamic equations, and implications for recently implemented experimental programs are discussed. C1 Univ Maryland, Inst Plasma Res, College Pk, MD 20742 USA. Univ Maryland, Dept Phys, College Pk, MD 20742 USA. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Univ Maryland, Dept Elect & Comp Engn, College Pk, MD 20742 USA. RP Sweet, D (reprint author), Univ Maryland, Inst Plasma Res, College Pk, MD 20742 USA. RI O, E/F-1630-2015; Antonsen, Thomas/D-8791-2017 OI Antonsen, Thomas/0000-0002-2362-2430 NR 39 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 JUN PY 2001 VL 63 IS 6 AR 066211 PN 2 PG 4 WC Physics, Fluids & Plasmas; Physics, Mathematical SC Physics GA 442KU UT WOS:000169285300055 ER PT J AU Hurricane, OA Glendinning, SG Remington, BA Drake, RP Dannenberg, KK AF Hurricane, OA Glendinning, SG Remington, BA Drake, RP Dannenberg, KK TI Late-time hohlraum pressure dynamics in supernova remnant experiments SO PHYSICS OF PLASMAS LA English DT Article ID NOVA; DRIVE; LASER AB It is shown that laser driven hohlraums obtain significant internal pressures which affect the hydrodynamics of high-energy density shock-tube experiments. By incorporating this previously neglected hohlraum pressure effect (in addition to the usual x-ray drive) into computer simulations which model the NOVA laser driven supernova remnant experiment [R. P. Drake, S. G. Glendinning, K. Estabrook, B. A. Remington, R. McCray, R. J. Williams, L. J. Suter, T. B. Smith, J. J. Carroll III, R. A. London, and E. Liang, Phys. Rev. Lett. 81, 2068 (1998)], calculations are able to reproduce the observed structure of hydrodynamic features. (C) 2001 American Institute of Physics. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. Univ Michigan, Dept Atmospher Ocean & Space Sci, Ann Arbor, MI 48109 USA. RP Hurricane, OA (reprint author), Univ Calif Lawrence Livermore Natl Lab, POB 808, Livermore, CA 94550 USA. RI Drake, R Paul/I-9218-2012 OI Drake, R Paul/0000-0002-5450-9844 NR 12 TC 6 Z9 7 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 JUN PY 2001 VL 8 IS 6 BP 2609 EP 2612 DI 10.1063/1.1373416 PG 4 WC Physics, Fluids & Plasmas SC Physics GA 435DU UT WOS:000168862800003 ER PT J AU Strand, PI Houlberg, WA AF Strand, PI Houlberg, WA TI Magnetic flux evolution in highly shaped plasmas SO PHYSICS OF PLASMAS LA English DT Article ID NEOCLASSICAL TRANSPORT; ENERGY CONFINEMENT; PHYSICS DESIGN; ASPECT-RATIO; HIGH-BETA; STELLARATOR; EQUILIBRIUM; TOKAMAK; REPRESENTATIONS; DIFFUSION AB The resistive evolution of magnetic flux in toroidal devices is studied. The formulation is applicable to general nonaxisymmetric (three-dimensional) toroidal configurations. In particular, it can treat highly shaped, high beta, three-dimensional stellarator configurations, as well as two-dimensional (axisymmetric) tokamak plasmas. The time evolution of the poloidal magnetic flux is posed in terms of the rotational transform, iota, and allows for a transparent inclusion of stellarator specific current-free contributions to iota. Strong diamagnetic and paramagnetic contributions to toroidal magnetic flux, as evident in spherical tokamaks and similar concepts, are calculated by direct iteration with an equilibrium solver. The nonlinear evolution equation is derived using a susceptance matrix formulation originally introduced by Grad and co-workers [Bateman, Nucl. Fusion 13, 227 (1973)]. Here, it is extended to general, nonstraight field line coordinate systems. The basic equations are described, explicit expressions for the susceptance matrix are given, and example applications using the stand-alone code, THRIFT (THRee-dimensional Inductive Flux evolution in Toroidal devices), are discussed. (C) 2001 American Institute of Physics. C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. EM strandpi@ornl.gov NR 31 TC 13 Z9 13 U1 1 U2 5 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 JUN PY 2001 VL 8 IS 6 BP 2782 EP 2792 DI 10.1063/1.1366618 PG 11 WC Physics, Fluids & Plasmas SC Physics GA 435DU UT WOS:000168862800023 ER PT J AU Lewandowski, JLV Williams, J Boozer, AH Lin, Z AF Lewandowski, JLV Williams, J Boozer, AH Lin, Z TI Gyrokinetic calculations of the neoclassical radial electric field in stellarator plasmas SO PHYSICS OF PLASMAS LA English DT Article ID PARTICLE-SIMULATION; TRANSPORT; STABILITY; SHEAR AB A novel method to calculate the neoclassical radial electric field in stellarator plasmas is described. The method, which does not have the inconvenience of large statistical fluctuations (noise) of the standard Monte Carlo technique, is based on the variation of the combined parallel and perpendicular pressures on a magnetic surface. Using a three-dimensional gyro-kinetic deltaf code, the calculation of the radial electric field (E-r) in the National Compact Stellarator Experiment [G. H. Neilson , Phys. Plasmas 7, 1911 (2000)] has been carried out. It is shown that a direct evaluation of E-r based on a direct calculation of the radial particle flux is not tractable due to the considerable noise. (C) 2001 American Institute of Physics. C1 Princeton Univ, Plasma Phys Lab, Princeton, NJ 08543 USA. Columbia Univ, Dept Appl Phys, New York, NY 10027 USA. RP Lewandowski, JLV (reprint author), Princeton Univ, Plasma Phys Lab, POB 451, Princeton, NJ 08543 USA. NR 22 TC 11 Z9 11 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 JUN PY 2001 VL 8 IS 6 BP 2849 EP 2854 DI 10.1063/1.1370363 PG 6 WC Physics, Fluids & Plasmas SC Physics GA 435DU UT WOS:000168862800030 ER PT J AU Amendt, P Shestakov, AI Landen, OL Bradley, DK Pollaine, SM Suter, LJ Turner, RE AF Amendt, P Shestakov, AI Landen, OL Bradley, DK Pollaine, SM Suter, LJ Turner, RE TI Thinshell symmetry surrogates for the National Ignition Facility: A rocket equation analysis SO PHYSICS OF PLASMAS LA English DT Article ID DRIVE; TARGETS; HOHLRAUMS; BALL AB Several techniques for inferring the degree of flux symmetry in indirectly driven cylindrical hohlraums have been developed over the past several years for eventual application to the National Ignition Facility (NIF) [Paisner , Laser Focus World 30, 75 (1994)]. These methods use various ignition capsule surrogates, including non-cryogenic imploded capsules [Hauer , Phys. Plasmas 2, 2488 (1995)], backlit aerogel foamballs [Amendt , Rev. Sci. Instrum. 66, 785 (1995)], reemission balls [Delamater, Magelssen, and Hauer, Phys. Rev. E 53, 5240 (1996)], and backlit thinshells [Pollaine , Phys. Plasmas 8, 2357 (2001)]. Recent attention has focussed on the backlit thinshells as a promising means for detecting higher-order Legendre flux asymmetries, e.g., P6 and P8, which are predicted to be important sources of target performance degradation on the NIF for levels greater than 1% [Haan , Phys. Plasmas 2, 2490 (1995)]. A key property of backlit thinshells is the strong amplification of modal flux asymmetry imprinting with shell convergence. A simple single-parameter analytic description based on a rocket model is presented which explores the degree of linearity of the shell response to an imposed flux asymmetry. Convergence and mass ablation effects introduce a modest level of nonlinearity in the shell response. The effect of target fabrication irregularities on shell distortion is assessed with the rocket model and particular sensitivity to shell thickness variations is shown. The model can be used to relate an observed or simulated backlit implosion trajectory to an ablation pressure asymmetry history. Ascertaining this history is an important element for readily establishing the degree of surrogacy of a symmetry target for a NIF ignition capsule. (C) 2001 American Institute of Physics. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. RP Amendt, P (reprint author), Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. NR 18 TC 10 Z9 10 U1 1 U2 5 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 JUN PY 2001 VL 8 IS 6 BP 2908 EP 2917 DI 10.1063/1.1369412 PG 10 WC Physics, Fluids & Plasmas SC Physics GA 435DU UT WOS:000168862800036 ER PT J AU Stoltz, PH Oliver, BV AF Stoltz, PH Oliver, BV TI Growth rates of the m=0 mode for Bennett equilibria with varying radial density and temperature profiles SO PHYSICS OF PLASMAS LA English DT Article ID Z-PINCH EXPERIMENTS; WIRE AB The linear growth of axisymmetric (m=0) perturbations for various Bennett pinch equilibria are studied numerically with the ALEGRA-MHD code [A. C. Robinson, C. J. Garasi, T. A. Haill, R. L. Morse, and P. H. Stoltz, Proceedings of the 26th IEEE Conference on Plasma Science (IEEE, Piscataway, NJ, 1999), p. 306]. Growth rates are calculated for both skin and diffuse current profiles with varied density and temperature profiles. A destabilizing effect of radially increasing temperature profiles is presented. A factor of three increase in the growth rate over a constant-temperature equilibrium is noted for an equilibrium which is ten times hotter on the edge than at the core. A qualitative explanation is given in terms of the sound speed in the radial region where the mode resides. (C) 2001 American Institute of Physics. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Stoltz, PH (reprint author), Tech X Corp, Boulder, CO 80301 USA. NR 14 TC 1 Z9 1 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 JUN PY 2001 VL 8 IS 6 BP 3096 EP 3098 DI 10.1063/1.1367323 PG 3 WC Physics, Fluids & Plasmas SC Physics GA 435DU UT WOS:000168862800059 ER PT J AU Chu, TK AF Chu, TK TI Symmetries-imposed configurational limit and configurational limit-induced change of symmetry in an inductively driven, dissipative tokamak plasma SO PHYSICS OF PLASMAS LA English DT Article ID MACROTOR TOKAMAK; FLUCTUATIONS; STATE AB Hastie showed that, in a force-free tokamak configuration that encloses the magnetic axis, there exists a critical on-axis safety factor, q(0), above which the q profile monotonically increases with radius and below which decreases with radius [J. Hastie, Nucl. Fusion 29, 96 (1989)]. This critical q(0), when interpreted under the requirement of maximum poloidal magnetic field energy for an inductively driven, dissipative tokamak plasma, which does not allow dq/dr <0 for the toroidally symmetric configuration, becomes the onset condition of helical symmetry during current peaking in a sawtooth cycle. The value is a result of the opposing demands placed on the sign of the on-axis curvature of the safety factor, q(')(0), by the two rotational symmetries (m=0 and n=0) of the configuration. (C) 2001 American Institute of Physics. C1 Princeton Univ, Plasma Phys Lab, Princeton, NJ 08543 USA. RP Chu, TK (reprint author), Princeton Univ, Plasma Phys Lab, POB 451, Princeton, NJ 08543 USA. NR 15 TC 1 Z9 1 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 JUN PY 2001 VL 8 IS 6 BP 3099 EP 3102 DI 10.1063/1.1369121 PG 4 WC Physics, Fluids & Plasmas SC Physics GA 435DU UT WOS:000168862800060 ER PT J AU Batygin, YK AF Batygin, YK TI Self-consistent analysis of three-dimensional uniformly charged ellipsoid with zero emittance SO PHYSICS OF PLASMAS LA English DT Article AB A self-consistent treatment of a three-dimensional ellipsoid with negligible emittance in the time-dependent external field is performed. Envelope equations describing the evolution of an ellipsoid boundary are discussed. For a complete model, it is required that the initial particle momenta be linear functions of the coordinates. Numerical examples and verification of the problem by three-dimensional particle-in-cell simulations are given. (C) 2001 American Institute of Physics. C1 Stanford Univ, Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. RP Stanford Univ, Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. NR 7 TC 4 Z9 4 U1 0 U2 0 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 JUN PY 2001 VL 8 IS 6 BP 3103 EP 3106 DI 10.1063/1.1370553 PG 4 WC Physics, Fluids & Plasmas SC Physics GA 435DU UT WOS:000168862800061 ER PT J AU Kardashev, BK Burenkov, YA Smirnov, BI Shpeizman, VV Stepanov, VA Chernov, VM Singh, D Goretta, KC AF Kardashev, BK Burenkov, YA Smirnov, BI Shpeizman, VV Stepanov, VA Chernov, VM Singh, D Goretta, KC TI Elasticity and inelasticity of ceramic samples of graphitelike boron nitride SO PHYSICS OF THE SOLID STATE LA English DT Article ID FIBROUS MONOLITHIC CERAMICS; TEMPERATURE AB This paper reports a study of the effect of temperature and strain amplitude on Young's modulus and ultrasonic damping in ceramic samples of graphitelike boron nitride prepared in the RF and USA by different technologies and using various additions to improve the mechanical properties of the ceramic. It is shown that, in addition to the influence on the effective elasticity modulus, additions improve the sample microplasticity, which apparently increases the strength of the material. (C) 2001 MAIK "Nauka/Interperiodica". C1 Russian Acad Sci, AF Ioffe Physicotech Inst, St Petersburg 194021, Russia. Leipunskii Inst Phys & Power Engn, Obninsk 249020, Russia. Argonne Natl Lab, Argonne, IL 60439 USA. RP Kardashev, BK (reprint author), Russian Acad Sci, AF Ioffe Physicotech Inst, Politekhnicheskaya Ul 26, St Petersburg 194021, Russia. RI Kardashev, Boris/D-2118-2014 NR 10 TC 6 Z9 6 U1 1 U2 3 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 1063-7834 J9 PHYS SOLID STATE+ JI Phys. Solid State PD JUN PY 2001 VL 43 IS 6 BP 1084 EP 1088 DI 10.1134/1.1378148 PG 5 WC Physics, Condensed Matter SC Physics GA 449NJ UT WOS:000169692100016 ER PT J AU Atwood, D Bar-Shalom, S Eilam, G Soni, A AF Atwood, D Bar-Shalom, S Eilam, G Soni, A TI CP violation in top physics SO PHYSICS REPORTS-REVIEW SECTION OF PHYSICS LETTERS LA English DT Review ID ELECTRIC-DIPOLE MOMENT; QUARK PAIR PRODUCTION; KOBAYASHI-MASKAWA MATRIX; CHARGED HIGGS BOSONS; STANDARD ELECTROWEAK MODEL; CHANGING NEUTRAL CURRENTS; LOW-ENERGY SUPERGRAVITY; PHOTON LINEAR COLLIDER; LARGE HADRON COLLIDER; CHARMLESS B-DECAYS AB CP violation in top physics is reviewed. The standard model has negligible effects, consequently CP violation searches involving the top quark may constitute the best way to look for physics beyond the standard model. Non-standard sources of CP violation due to an extended Higgs sector with and without natural flavor conservation and supersymmetric theories are discussed. Experimental feasibility of detecting CP violation effects in top quark production and decays in high energy e(+)e(-), gamma gamma, mu (+)mu (-), pp and p (p) over barp colliders are surveyed. Searches for the electric. electro-weak and the chrome-electric dipole moments of the top quark in e(+)e(-) --> t (t) over bar and in pp <-- t (t) over barX are described. In addition, other mechanisms that appear promising for experiments, e.g., tree-level CP violation in e(+)e(-) --> t (t) over barh, t (t) over barZ, t (t) over bar nu (e)<()over bar>(e) and in the top decay t --> b tau nu (tau) and CP violation driven by s-channel Higgs exchanges in pp,gamma gamma,mu (+)mu (-) --> t (t) over bar, etc. are also discussed. (C) 2001 Published by Elsevier Science B.V. C1 Iowa State Univ, Dept Phys & Astron, Ames, IA 50011 USA. Sezione Roma, Ist Nazl Fis Nucl, Rome, Italy. Univ Roma 1, Dept Phys, Rome, Italy. Technion Israel Inst Technol, Dept Phys, IL-32000 Haifa, Israel. Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. Univ Calif Riverside, Dept Phys, Riverside, CA 92521 USA. RP Atwood, D (reprint author), Iowa State Univ, Dept Phys & Astron, Ames, IA 50011 USA. EM atwood@iastate.edu; shaouly.barshalom@roma1.infn.it; eilam@physics.technion.ac.il; soni@bnl.gov NR 344 TC 36 Z9 36 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0370-1573 EI 1873-6270 J9 PHYS REP JI Phys. Rep.-Rev. Sec. Phys. Lett. PD JUN PY 2001 VL 347 IS 1-2 BP 2 EP 222 PG 221 WC Physics, Multidisciplinary SC Physics GA 444XU UT WOS:000169426000001 ER PT J AU Rosenfeld, AH Kaarsberg, TM Romm, J AF Rosenfeld, AH Kaarsberg, TM Romm, J TI Reducing CO2 emissions: Turn down the heat, crank up efficiency - reply SO PHYSICS TODAY LA English DT Letter C1 Calif Energy Commiss, Sacramento, CA 95814 USA. US DOE, Washington, DC USA. Ctr Energy & Climate Solut, Annandale, VA USA. RP Rosenfeld, AH (reprint author), Calif Energy Commiss, Sacramento, CA 95814 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 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 JUN PY 2001 VL 54 IS 6 BP 80 EP 80 PG 1 WC Physics, Multidisciplinary SC Physics GA 436BV UT WOS:000168917400026 ER PT J AU Uretsky, J AF Uretsky, J TI Do moons point to new physics? SO PHYSICS WORLD LA English DT Letter C1 Argonne Natl Lab, Argonne, IL 60439 USA. RP Uretsky, J (reprint author), Argonne Natl Lab, 9700 S Cass Ave, Argonne, IL 60439 USA. NR 0 TC 0 Z9 0 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 JUN PY 2001 VL 14 IS 6 BP 24 EP 25 PG 2 WC Physics, Multidisciplinary SC Physics GA 440HN UT WOS:000169170000025 ER PT J AU Rillig, MC Wright, SF Nichols, KA Schmidt, WF Torn, MS AF Rillig, MC Wright, SF Nichols, KA Schmidt, WF Torn, MS TI Large contribution of arbuscular mycorrhizal fungi to soil carbon pools in tropical forest soils SO PLANT AND SOIL LA English DT Article DE glomalin; microbial biomass; soil carbon; soil chronosequence; hyphae ID ECOSYSTEM; HYPHAE; ACCUMULATION; COLONIZATION; ASSOCIATIONS; EXTRACTION; FRACTIONS; DYNAMICS; GLOMALIN; ECONOMY AB The origins and composition of soil organic matter (SOM) are still largely uncertain. Arbuscular mycorrhizal fungi (AMF) are recognized as indirect contributors through their influence on soil aggregation, plant physiology, and plant community composition. Here we present evidence that AMF can also make large, direct contributions to SOM. Glomalin, a recently discovered glycoprotein produced by AMF hyphae, was detected in tropical soils in concentrations of over 60 mg cm(-3). Along a chronosequence of soils spanning ages from 300 to 4.1 Mio years, a pattern of glomalin concentrations is consistent with the hypothesis that this protein accumulates in soil. Carbon dating of glomalin indicated turnover at time scales of several years to decades, much longer than the turnover of AMF hyphae (which is assumed to be on the order of days to weeks). This suggests that contributions of mycorrhizae to soil carbon storage based on hyphal biomass in soil and roots may be an underestimate. The amount of C and N in glomalin represented a sizeable amount (ca. 4-5%) of total soil C and N in the oldest soils. Our results thus indicate that microbial (fungal) carbon that is not derived from above- or below-ground litter can make a significant contribution to soil carbon and nitrogen pools and can far exceed the contributions of soil microbial biomass (ranging from 0.08 to 0.2% of total C for the oldest soils). C1 Univ Montana, Div Biol Sci, Missoula, MT 59812 USA. ARS, USDA, Beltsville, MD 20705 USA. Lawrence Berkeley Lab, Ctr Isotope Geochem, Berkeley, CA 94720 USA. RP Rillig, MC (reprint author), Univ Montana, Div Biol Sci, HS 104, Missoula, MT 59812 USA. RI Rillig, Matthias/B-3675-2009; Torn, Margaret/D-2305-2015 OI Rillig, Matthias/0000-0003-3541-7853; NR 39 TC 219 Z9 261 U1 14 U2 144 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0032-079X J9 PLANT SOIL JI Plant Soil PD JUN PY 2001 VL 233 IS 2 BP 167 EP 177 DI 10.1023/A:1010364221169 PG 11 WC Agronomy; Plant Sciences; Soil Science SC Agriculture; Plant Sciences GA 448UB UT WOS:000169647400003 ER PT J AU Wilson, KB Baldocchi, DD Hanson, PJ AF Wilson, KB Baldocchi, DD Hanson, PJ TI Leaf age affects the seasonal pattern of photosynthetic capacity and net ecosystem exchange of carbon in a deciduous forest SO PLANT CELL AND ENVIRONMENT LA English DT Article DE Ameriflux; canopy model; leaf age; maximum carboxylation rate (V-cmax) ID WATER-VAPOR EXCHANGE; UPLAND OAK FOREST; STOMATAL CONDUCTANCE; BOREAL FOREST; HYDRAULIC-PROPERTIES; EDDY-CORRELATION; MODEL; DIOXIDE; CANOPY; VARIABILITY AB Temporal trends in photosynthetic capacity are a critical factor in determining the seasonality and magnitude of ecosystem carbon fluxes, At a mixed deciduous forest in the south-eastern United States (Walker Branch Watershed, Oak Ridge, TN, USA), we independently measured seasonal trends in photosynthetic capacity (using single-leaf gas exchange techniques) and the whole-canopy carbon flux (using the eddy covariance method). Soil respiration was also measured using chambers and an eddy covariance system beneath the canopy, These independent chamber and eddy covariance measurements, along with a biophysical model (CANOAK), are used to examine how leaf age affects the seasonal pattern of carbon uptake during the growing season. When the measured seasonality in photosynthetic capacity is represented in the CANOAK simulations, there is good agreement with the eddy covariance data on the seasonal trends in carbon uptake. Removing the temporal trends in the simulations by using the early season maximum value of photosynthetic capacity over the entire growing season overestimates the annual carbon uptake by about 300 g C m(-2) year(-1)-half the total estimated annual net ecosystem exchange. Alternatively, use of the mean value of photosynthetic capacity incorrectly simulates the seasonality in carbon uptake by the forest. In addition to changes related to leaf development and senescence, photosynthetic capacity decreased in the middle and late summer, even when leaf nitrogen was essentially constant. When only these middle and late summer reductions were neglected in the model simulations, CANOAK still overestimated the carbon uptake by an amount comparable to 25% of the total annual net ecosystem exchange. C1 NOAA, Atmospher Turbulence & Diffus Div, Oak Ridge, TN 37831 USA. Univ Calif Berkeley, Dept Environm Sci Policy & Management, Berkeley, CA 94720 USA. Oak Ridge Natl Lab, Div Environm Sci, Oak Ridge, TN 37831 USA. RP Wilson, KB (reprint author), NOAA, Atmospher Turbulence & Diffus Div, POB 2456, Oak Ridge, TN 37831 USA. RI Hanson, Paul J./D-8069-2011; Baldocchi, Dennis/A-1625-2009 OI Hanson, Paul J./0000-0001-7293-3561; Baldocchi, Dennis/0000-0003-3496-4919 NR 53 TC 158 Z9 167 U1 8 U2 39 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 JUN PY 2001 VL 24 IS 6 BP 571 EP 583 DI 10.1046/j.0016-8025.2001.00706.x PG 13 WC Plant Sciences SC Plant Sciences GA 441JH UT WOS:000169226900001 ER PT J AU Chiu, HJ Chen, HL Lin, JS AF Chiu, HJ Chen, HL Lin, JS TI Crystallization induced microstructure of crystalline/crystalline poly(vinylidenefluoride)/poly(3-hydroxybutyrate) blends probed by small angle X-ray scattering SO POLYMER LA English DT Article DE blends; morphology; crystallization ID POLY(ETHYLENE OXIDE) BLENDS; POLY(EPSILON-CAPROLACTONE) POLYCARBONATE BLENDS; POLY(VINYLIDENE FLUORIDE); POLYETHYLENE BLENDS; PHASE SEGREGATION; MISCIBLE BLENDS; POLY(1,4-BUTYLENE ADIPATE); MORPHOLOGY; COCRYSTALLIZATION; BEHAVIOR AB The lamellar morphology of a melt-miscible blend consisting of two crystalline constituents, poly(vinylidene fluoride) (PVDF) and poly(3-hydroxybutyrate) (PHB), has been investigated by small angle X-ray scattering (SAXS). Owing to the proximity of melting points, PVDF and PHB crystallized over essentially the same temperature range, and consequently created a crystalline/crystalline state with the morphology characterized by the spatial arrangement of PVDF and PHB lamellae. Irrespective of the crystallization temperatures (T,), the SAXS patterns revealed the presences of two lamellar stack (LS) domains, where one contained mainly PVDF lamellae (PVDF LS domain) and the other primarily consisted of PHB lamellae (PHB LS domain). The interlamellar (IL) regions of both LS domains were found to contain mixed amorphous PVDF and PHB. The blends crystallized at higher T-c exhibited smaller SAXS invariants. This observed T-c dependence was connected with the disparity in crystallization kinetics that gave rise to different LS domain sizes at different T(c)s. (C) 2001 Elsevier Science Ltd. All rights reserved. C1 Natl Tsing Hua Univ, Dept Chem Engn, Hsinchu 30013, Taiwan. Oak Ridge Natl Lab, Div Solid State, Oak Ridge, TN 37831 USA. RP Chen, HL (reprint author), Natl Tsing Hua Univ, Dept Chem Engn, Hsinchu 30013, Taiwan. NR 29 TC 51 Z9 52 U1 1 U2 14 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 JUN PY 2001 VL 42 IS 13 BP 5749 EP 5754 DI 10.1016/S0032-3861(01)00072-6 PG 6 WC Polymer Science SC Polymer Science GA 418MP UT WOS:000167896200030 ER PT J AU Tissot, RG Rodriguez, MA Sipola, DL Voigt, JA AF Tissot, RG Rodriguez, MA Sipola, DL Voigt, JA TI X-ray powder diffraction study of synthetic Palmierite, K2Pb(SO4)(2) SO POWDER DIFFRACTION LA English DT Article DE Palmierite; X-ray powder diffraction; Rietveld refinement; preferred orientation; synthesis AB Palmierite (K2Pb(SO4)(2)) has been prepared via a chemical synthesis method. Intensity differences were observed when X-ray powder data from the newly synthesized compound were compared to the published powder diffraction card (PDF) 29-1015 for Palmierite. Investigation of these differences indicated the possibility of preferred orientation and/or chemical inhomogeneity affecting intensities, particularly those of the basal (00l) reflections. Annealing of the Palmierite was found to reduce the effects of preferred orientation. Electron microprobe analysis confirmed K:Pb:S as 2:1:2 for the for the annealed Palmierite powder. Subsequent least-squares refinement and Rietveld analysis of the annealed powder showed peak intensities very close to that of a calculated Palmierite pattern (based on single crystal data), yet substantially higher than many of the PDF 29-1015 published intensities. Further investigation of peak intensity variation via calculated patterns suggested that the intensity discrepancies between the annealed sample and those found in PDF 29-1015 were potentially due to chemical variation in the K2Pb(SO4)(2) composition. X-ray powder diffraction and crystal data for Palmierite are reported for the annealed sample. Palmierite is trigonal/hexagonal with unit cell parameters a = 5.497(1) , c = 20.864(2) Angstrom, space group R-3m(166), and Z = 3. (C) 2001 International Centre for Diffraction Data. C1 Sandia Natl Labs, Mat Characterizat Dept 1822, Albuquerque, NM 87185 USA. Sandia Natl Labs, Ceram Mat Dept 1843, Albuquerque, NM 87185 USA. RP Tissot, RG (reprint author), Sandia Natl Labs, Mat Characterizat Dept 1822, POB 5800, Albuquerque, NM 87185 USA. NR 7 TC 6 Z9 6 U1 0 U2 5 PU J C P D S-INT CENTRE DIFFRACTION DATA PI NEWTOWN SQ PA 12 CAMPUS BLVD, NEWTOWN SQ, PA 19073-3273 USA SN 0885-7156 J9 POWDER DIFFR JI Powder Diffr. PD JUN PY 2001 VL 16 IS 2 BP 92 EP 97 DI 10.1154/1.1370567 PG 6 WC Materials Science, Characterization & Testing SC Materials Science GA 445GW UT WOS:000169450600006 ER PT J AU Perry, AM Weinberg, AM AF Perry, AM Weinberg, AM TI Nuclear power and the greenhouse effect SO PROCEEDINGS OF THE AMERICAN PHILOSOPHICAL SOCIETY LA English DT Article C1 Oak Ridge Associated Univ, Oak Ridge, TN 37830 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER PHILOSOPHICAL SOC PI PHILADELPHIA PA 104 SOUTH FIFTH ST, PHILADELPHIA, PA 19106-3387 USA SN 0003-049X J9 P AM PHILOS SOC JI Proc. Amer. Philos. Soc. PD JUN PY 2001 VL 145 IS 2 BP 184 EP 186 PG 3 WC Humanities, Multidisciplinary SC Arts & Humanities - Other Topics GA 440NM UT WOS:000169181300004 ER PT J AU Dong, WQ Lal, D Ransom, B Berger, W Caffee, MW AF Dong, WQ Lal, D Ransom, B Berger, W Caffee, MW TI Marine biogeochemistries of Be and Al: A study based on cosmogenic Be-10, Be and Al in marine calcite, aragonite, and opal SO PROCEEDINGS OF THE INDIAN ACADEMY OF SCIENCES-EARTH AND PLANETARY SCIENCES LA English DT Article DE cosmogenic Be-10; Be, Al marine geochemistry; aeolian Be, Al ID ICE CORE; SOUTH-ATLANTIC; TRACE-METALS; PACIFIC; CLIMATE; OCEAN; CYCLE; BERYLLIUM-10; GREENLAND; CADMIUM AB The geochemical behaviors of Be and Al in ocean waters have been successfully studied in recent years using natural, cosmogenic, radioactive Be-10 and Al-26 as tracers. The present day dissolved concentrations and distribution of the stable and radioactive isotopes of Be and Al in ocean waters have revealed their short residence times and appreciable effects of exchange fluxes at the coastal and ocean-sediment interfaces. It follows that concentrations of these particle-active elements must have varied in the past with temporal changes in climate, biological productivity and aeolian flux of continental detritus to the oceans. We therefore investigated the feasibility of extending the measurements of Be and At isotope concentrations in marine systems to the 10(3)-10(6) y BP time scale. We report here the discovery of significant amounts of intrinsic Be and Al in marine foraminiferal calcite and coral aragonite, and of Al in opal (radiolarians) and aragonite (coral), which makes it possible to determine Be-10/Be and Al-26/Al in oceans in the past. We also report measured Be-10/Be-9 in foraminiferal calcite in Pacific Ocean cores, which reveal that the concentrations and ratios of the stable and cosmogenic isotopes of Be and Al have varied significantly in the past 30 ky. The implications of these results are discussed. C1 Univ Calif San Diego, Scripps Inst Oceanog, Geosci Res Div, La Jolla, CA 92093 USA. Lawrence Livermore Natl Lab, Ctr Accelerator Mass Spectrometry, Livermore, CA 94551 USA. RP Dong, WQ (reprint author), Univ Nevada, Dept Geosci, 4505 Maryland Pkwy,Box 454010, Las Vegas, NV 89154 USA. RI Caffee, Marc/K-7025-2015 OI Caffee, Marc/0000-0002-6846-8967 NR 38 TC 5 Z9 5 U1 0 U2 6 PU INDIAN ACADEMY SCIENCES PI BANGALORE PA P B 8005 C V RAMAN AVENUE, BANGALORE 560 080, INDIA SN 0253-4126 J9 P INDIAN AS-EARTH JI Proc. Indian Acad. Sci.-Earth Planet. Sci PD JUN PY 2001 VL 110 IS 2 BP 95 EP 102 PG 8 WC Geosciences, Multidisciplinary SC Geology GA 522ZF UT WOS:000173926300001 ER PT J AU Fthenakis, VM AF Fthenakis, VM TI Multilayer protection analysis for photovoltaic manufacturing facilities SO PROCESS SAFETY PROGRESS LA English DT Article ID HEALTH; ISSUES; SAFETY AB This paper gives an overview of environmental health and safety (EHS) issues related to photovoltaic (PV) technologies, and strategies for reducing EHS risks. These strategies include layers of prevention and mitigation in six sequential steps. Prevention layers are related to safer technologies, processes, and materials; safer use of materials; preventing accident-initiating events; preventing or minimizing releases, and preventing human exposures. The mitigation options include secondary confinement, emergency scrubbers and absorption units. As the PV industry approaches these issues and mitigation strategies in a vigilant, systematic way, the risk to industry, workers, and the public will be minimized. C1 Brookhaven Natl Lab, Dept Environm Sci, Environm Res & Technol Div, Upton, NY 11973 USA. RP Fthenakis, VM (reprint author), Brookhaven Natl Lab, Dept Environm Sci, Environm Res & Technol Div, Upton, NY 11973 USA. NR 13 TC 4 Z9 4 U1 1 U2 1 PU AMER INST CHEMICAL ENGINEERS PI NEW YORK PA 3 PARK AVE, NEW YORK, NY 10016-5901 USA SN 1066-8527 J9 PROCESS SAF PROG JI Process Saf. Prog. PD JUN PY 2001 VL 20 IS 2 BP 87 EP 94 DI 10.1002/prs.680200206 PG 8 WC Engineering, Chemical SC Engineering GA 446BZ UT WOS:000169494200004 ER PT J AU Turner, MS AF Turner, MS TI A sober assessment of cosmology at the new millennium SO PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF THE PACIFIC LA English DT Editorial Material ID UNIVERSE; NUCLEOSYNTHESIS; SUPERNOVAE C1 Univ Chicago, Enrico Fermi Inst, Dept Astron & Astrophys, Chicago, IL 60637 USA. Univ Chicago, Enrico Fermi Inst, Dept Phys, Chicago, IL 60637 USA. Fermi Natl Accelerator Lab, NASA Fermi Astrophys Ctr, Batavia, IL 60510 USA. RP Turner, MS (reprint author), Univ Chicago, Enrico Fermi Inst, Dept Astron & Astrophys, Chicago, IL 60637 USA. NR 25 TC 15 Z9 16 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-6280 J9 PUBL ASTRON SOC PAC JI Publ. Astron. Soc. Pac. PD JUN PY 2001 VL 113 IS 784 BP 653 EP 657 DI 10.1086/320800 PG 5 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 444YW UT WOS:000169429000001 ER PT J AU Willick, JA Thompson, KL Mathiesen, BF Perlmutter, S Knop, RA Hill, GJ AF Willick, JA Thompson, KL Mathiesen, BF Perlmutter, S Knop, RA Hill, GJ TI The Stanford Cluster Search: Scope, method, and preliminary results SO PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF THE PACIFIC LA English DT Article ID X-RAY-CLUSTERS; COLD DARK-MATTER; OPTICALLY SELECTED CLUSTERS; HOBBY-EBERLY TELESCOPE; HIGH-REDSHIFT CLUSTER; GALAXY CLUSTERS; MEASURING OMEGA(0); MATCHED-FILTER; RICH CLUSTERS; SPACE DENSITY AB We describe the scientific motivation behind, and the methodology of, the Stanford Cluster Search (StaCS), a program to compile a catalog of optically selected galaxy clusters at intermediate and high (0.3 less than or similar to z less than or similar to 1) redshifts. The clusters are identified using a matched filter algorithm applied to deep CCD images covering similar to 60 deg(2) of sky. These images are obtained from several data archives, principally that of the Berkeley Supernova Cosmology Project of Perlmutter et al. Potential clusters are confirmed with spectroscopic observations at the 9.2 m Hobby-Eberly Telescope. Follow-up observations at optical, submillimeter, and X-ray wavelengths are planned in order to estimate cluster masses. Our long-term scientific goal is to measure the cluster number density as a function of mass and redshift, n(M, z), which is sensitive to the cosmological density parameter Omega (m) and the amplitude of density fluctuations sigma (8). The combined data set will contain clusters ranging over an order of magnitude in mass and allow constraints on these parameters accurate to similar to 10%. We present our first spectroscopically confirmed cluster candidates and describe how to access them electronically. C1 Stanford Univ, Dept Phys, Stanford, CA 94305 USA. EO Lawrence Berkeley Natl Lab, Inst Nucl & Particle Phys, Berkeley, CA 94720 USA. Univ Texas, McDonald Observ, Austin, TX 78712 USA. RI Perlmutter, Saul/I-3505-2015 OI Perlmutter, Saul/0000-0002-4436-4661 NR 69 TC 6 Z9 6 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-6280 J9 PUBL ASTRON SOC PAC JI Publ. Astron. Soc. Pac. PD JUN PY 2001 VL 113 IS 784 BP 658 EP 676 DI 10.1086/320814 PG 19 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 444YW UT WOS:000169429000002 ER PT J AU Boone, C AF Boone, C TI How to work with national labs SO R&D MAGAZINE LA English DT Article C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Boone, C (reprint author), Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU CAHNERS-DENVER PUBLISHING CO PI OAK BROOK PA 2000 CLEARWATER DR, OAK BROOK, IL 60523-8809 USA SN 0746-9179 J9 R&D MAG JI R D Mag. PD JUN PY 2001 VL 43 IS 6 BP 57 EP 57 PG 1 WC Engineering, Industrial; Multidisciplinary Sciences SC Engineering; Science & Technology - Other Topics GA 451TM UT WOS:000169817400033 ER PT J AU Heilbronn, L Townsend, LW AF Heilbronn, L Townsend, LW TI Overview of ground-based neutron measurements applicable to GCR and SPE transport through shielding materials in space SO RADIATION MEASUREMENTS LA English DT Article ID PRODUCTION CROSS-SECTIONS; STOPPING-LENGTH TARGETS; 585 MEV PROTONS; 256-MEV PROTONS; MEV-NUCLEON; 12-LESS-THAN-OR-EQUAL-TO-A-LESS-THAN-OR-EQUAL-TO-238; SYSTEMATICS; SPECTRA; CARBON; YIELDS C1 Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. Univ Tennessee, Dept Nucl Engn, Knoxville, TN 37996 USA. RP Heilbronn, L (reprint author), Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. RI Heilbronn, Lawrence/J-6998-2013 OI Heilbronn, Lawrence/0000-0002-8226-1057 NR 24 TC 0 Z9 0 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 1350-4487 J9 RADIAT MEAS JI Radiat. Meas. PD JUN PY 2001 VL 33 IS 3 SI SI BP 269 EP 273 DI 10.1016/S1350-4487(00)00103-7 PG 5 WC Nuclear Science & Technology SC Nuclear Science & Technology GA 439EW UT WOS:000169098700007 PM 11855408 ER PT J AU Lennox, AJ AF Lennox, AJ TI Accelerators for cancer therapy SO RADIATION PHYSICS AND CHEMISTRY LA English DT Article; Proceedings Paper CT 8th International Symposium on Radiation Physics (ISRP-8) CY JUN 05-09, 2000 CL PRAGUE, CZECH REPUBLIC SP Int Radiat Phys Soc, Czech Tech Univ, Fac Nucl Sci & Phys Engn, Czech Energy Co DE hadron therapy; neutron therapy; proton therapy; medical accelerators ID RADIOTHERAPY AB The vast majority of radiation treatments for cancerous tumors are given using electron linacs that provide both electrons and photons at several energies. Design and construction of these linacs are based on mature technology that is rapidly becoming more and more standardized and sophisticated. The use of hadrons such as neutrons, protons, alphas, or carbon, oxygen and neon ions is relatively new. Accelerators for hadron therapy are far from standardized, but the use of hadron therapy as an alternative to conventional radiation has led to significant improvements and refinements in conventional treatment techniques. This paper presents the rationale for radiation therapy, describes the accelerators used in conventional and hadron therapy, and outlines the issues that must still be resolved in the emerging field of hadron therapy. (C) 2001 Elsevier Science Ltd. All rights reserved. C1 Fermilab Natl Accelerator Lab, Fermilab Neutron Therapy Facil, Batavia, IL 60510 USA. RP Lennox, AJ (reprint author), Fermilab Natl Accelerator Lab, Fermilab Neutron Therapy Facil, POB 500,Mail Stop 301, Batavia, IL 60510 USA. EM alennox@fnal.gov NR 16 TC 3 Z9 3 U1 0 U2 4 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 JUN PY 2001 VL 61 IS 3-6 BP 223 EP 226 DI 10.1016/S0969-806X(01)00244-4 PG 4 WC Chemistry, Physical; Nuclear Science & Technology; Physics, Atomic, Molecular & Chemical SC Chemistry; Nuclear Science & Technology; Physics GA 464HF UT WOS:000170526600007 ER PT J AU Chantler, CT Tran, CQ Paterson, D Barnea, Z Cookson, DJ AF Chantler, CT Tran, CQ Paterson, D Barnea, Z Cookson, DJ TI Direct observation of scattering contributions in X-ray attenuation measurements, and evidence for Rayleigh scattering from copper samples rather than thermal-diffuse or Bragg-Laue scattering SO RADIATION PHYSICS AND CHEMISTRY LA English DT Article; Proceedings Paper CT 8th International Symposium on Radiation Physics (ISRP-8) CY JUN 05-09, 2000 CL PRAGUE, CZECH REPUBLIC SP Int Radiat Phys Soc, Czech Tech Univ, Fac Nucl Sci & Phys Engn, Czech Energy Co DE attenuation coefficients; X-ray scattering; atomic form factors ID CROSS-SECTIONS; ENERGIES; Z=1-92 AB High-precision attenuation measurements can now lead to a direct assessment of scattering models in the X-ray regime. This is true not just at high energies but even when scattering cross-sections typically lie below 0.1% of the photoelectric absorption cross-section. This allows model-independent results to be obtained in these attenuation experiments for the first time. (C) 2001 Elsevier Science Ltd. All rights reserved. C1 Univ Melbourne, Sch Phys, Parkville, Vic 3010, Australia. Australian Nucl Sci & Technol Org, Menai, NSW 2234, Australia. Argonne Natl Lab, Chem Mat CARS CAT, Sector 15, Argonne, IL 60439 USA. RP Chantler, CT (reprint author), Univ Melbourne, Sch Phys, Parkville, Vic 3010, Australia. RI Chantler, Christopher/D-4744-2013; Tran, Chanh/M-7868-2015 OI Chantler, Christopher/0000-0001-6608-0048; NR 9 TC 4 Z9 4 U1 0 U2 2 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 JUN PY 2001 VL 61 IS 3-6 BP 347 EP 350 DI 10.1016/S0969-806X(01)00262-6 PG 4 WC Chemistry, Physical; Nuclear Science & Technology; Physics, Atomic, Molecular & Chemical SC Chemistry; Nuclear Science & Technology; Physics GA 464HF UT WOS:000170526600026 ER PT J AU Lloyd, DC Lucas, JN Edwards, AA Deng, W Valente, E Hone, PA Moquet, JE AF Lloyd, DC Lucas, JN Edwards, AA Deng, W Valente, E Hone, PA Moquet, JE TI A study to verify a reported excess of chromosomal aberrations in blood lymphocytes of Namibian uranium miners SO RADIATION RESEARCH LA English DT Article ID IONIZING-RADIATION; EXPOSURE; TRANSLOCATIONS; DAMAGE; FISH; AGE; POPULATION; SMOKING AB This report describes a study to verify an earlier report of excess chromosomal damage in the blood lymphocytes of uranium miners. Coded blood samples from 10 miners and 10 controls were analyzed conventionally for unstable aberrations and by FISH for translocations. Conventional analysis, scoring 1000 metaphases per subject, showed no significant difference between miners and controls in the frequencies of chromosome- and chromatid-type aberrations. Investigators at two laboratories undertook FISH analyses, each scoring 4000 metaphases per subject. When the data from each laboratory were examined separately, one found slightly more translocations in the miners while the other found fewer. In neither case was the difference significant at the 95% level of confidence. Combining the data likewise showed no significant excess of damage in the miners. This applied to simple one and two-way translocations and to cells with complex exchanges. There was no correlation between levels of translocations and total lifetime doses from occupational and/or background irradiation. A borderline significant excess of rogue tells was found in the miners. This may be a chance observation, as these rare, highly abnormal cells are considered to be unrelated to radiation exposure and are probably due to a virus. The overall conclusion is that the frequency of chromosomal damage in the miners did not exceed that in the controls. Therefore, the result of the earlier study was not confirmed. (C) 2001 by Radiation Research Society. C1 Natl Radiol Protect Board, Didcot OX11 0RQ, Oxon, England. Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Lloyd, DC (reprint author), Natl Radiol Protect Board, Didcot OX11 0RQ, Oxon, England. NR 25 TC 22 Z9 23 U1 0 U2 1 PU RADIATION RESEARCH SOC PI OAK BROOK PA 820 JORIE BOULEVARD, OAK BROOK, IL 60523 USA SN 0033-7587 J9 RADIAT RES JI Radiat. Res. PD JUN PY 2001 VL 155 IS 6 BP 809 EP 817 DI 10.1667/0033-7587(2001)155[0809:ASTVAR]2.0.CO;2 PG 9 WC Biology; Biophysics; Radiology, Nuclear Medicine & Medical Imaging SC Life Sciences & Biomedicine - Other Topics; Biophysics; Radiology, Nuclear Medicine & Medical Imaging GA 437KX UT WOS:000168991800007 PM 11352763 ER PT J AU Chernikova, SB Lindquist, KL Elkind, MM AF Chernikova, SB Lindquist, KL Elkind, MM TI Cell cycle-dependent effects of wortmannin on radiation survival and mutation SO RADIATION RESEARCH LA English DT Article ID STRAND BREAK REPAIR; HAMSTER OVARY CELLS; HUMAN TUMOR-CELLS; PHOSPHATIDYLINOSITOL 3-KINASE; MAMMALIAN-CELLS; PROTEIN-KINASE; PHOSPHOINOSITIDE 3-KINASE; IONIZING-RADIATION; DNA-DAMAGE; S-PHASE AB Wortmannin, a known radiation sensitizer, has been used in experiments with synchronized cells to compare its effect on radiation survival and mutation induction within the cell cycle. PL61 cells (CHO cells with an inactivated HPRT gene containing a single active copy of a bacterial gpt gene) were synchronized by mitotic selection. Wortmannin administered before gamma irradiation caused a greater sensitization in G(1)-phase cells relative to late S/G(2)-phase cells. Preferential radiosensitization of G(1)-phase cells by wortmannin sets a limit to the proposed use of wortmannin in radiation therapy, since, in contrast to normal tissues, tumors usually have high proportions of S-phase cells. Wortmannin increased mutation frequencies in both G(1)- and S/G(2)-phase cells. Interestingly, relative increases in radiation-induced mutations in G(1) and S/G(2) phases were comparable. The results are discussed in terms of the contributions of different repair modes in the production of mutations. (C) 2001 by Radiation Research Society. C1 Colorado State Univ, Dept Radiol Hlth Sci, Ft Collins, CO 80523 USA. RP Chernikova, SB (reprint author), Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Div Life Sci, 1 Cyclotron Rd, Berkeley, CA 94720 USA. FU NCI NIH HHS [CA47497] NR 35 TC 7 Z9 7 U1 0 U2 1 PU RADIATION RESEARCH SOC PI OAK BROOK PA 820 JORIE BOULEVARD, OAK BROOK, IL 60523 USA SN 0033-7587 J9 RADIAT RES JI Radiat. Res. PD JUN PY 2001 VL 155 IS 6 BP 826 EP 831 DI 10.1667/0033-7587(2001)155[0826:CCDEOW]2.0.CO;2 PG 6 WC Biology; Biophysics; Radiology, Nuclear Medicine & Medical Imaging SC Life Sciences & Biomedicine - Other Topics; Biophysics; Radiology, Nuclear Medicine & Medical Imaging GA 437KX UT WOS:000168991800009 PM 11352765 ER PT J AU Zhang, ZL Nelakuditi, S Aggarwal, R Tsang, RP AF Zhang, ZL Nelakuditi, S Aggarwal, R Tsang, RP TI Efficient selective frame discard algorithms for stored video delivery across resource constrained networks SO REAL-TIME IMAGING LA English DT Article ID VBR VIDEO; TRANSMISSION; ATM AB Video delivery from a server to a client across a network is an important component of many multimedia applications. While delivering a video stream across a resource constrained network, loss of frames may be unavoidable. Under such circumstances, it is desirable to find a server transmission schedule that call efficiently utilize the network resources while maximizing the perceived quality-of-service (QoS) at the client. To address this issue, in this paper we introduce the notion of selective frame discard at the server and formulate the optimal selective-frame discard problem using a QoS-based cost function, Given network bandwidth and client buffer constraints, we develop an O(N log N) algorithm to find the minimum number of frames that must be discarded in order to meet these constraints. The correctness of the algorithm is also formally established. We present a dynamic programming based algorithm for solving the problem of optimal selective frame discard. Since the computational complexity of the optimal algorithm is prohibitively high in general, we also develop several efficient heuristic algorithms for selective frame discard, These algorithms are evaluated using JPEG and MPEG video traces. (C) 2001 Academic Press. C1 Univ Minnesota, Dept Comp Sci & Engn, Minneapolis, MN 55455 USA. Sandia Natl Labs, Livermore, CA 94550 USA. RP Univ Minnesota, Dept Comp Sci & Engn, Minneapolis, MN 55455 USA. EM zhzhang@cs.umn.edu; srihari@cs.umn.edu; raggarwa@cs.umn.edu; rtsang@ca.sandia.gov NR 31 TC 13 Z9 13 U1 0 U2 0 PU ACADEMIC PRESS LTD- ELSEVIER SCIENCE LTD PI LONDON PA 24-28 OVAL RD, LONDON NW1 7DX, ENGLAND SN 1077-2014 J9 REAL-TIME IMAGING JI Real-Time Imaging PD JUN PY 2001 VL 7 IS 3 BP 255 EP 273 DI 10.1006/rtim.2001.0226 PG 19 WC Computer Science, Artificial Intelligence; Computer Science, Software Engineering; Computer Science, Theory & Methods SC Computer Science GA 444UX UT WOS:000169419400004 ER PT J AU Seely, J Back, C Deslattes, R Hudson, L Holland, G Bell, P Miller, M AF Seely, J Back, C Deslattes, R Hudson, L Holland, G Bell, P Miller, M TI Hard x-ray spectrometers for the national ignition facility SO REVIEW OF SCIENTIFIC INSTRUMENTS LA English DT Article ID PLASMA AB A National Ignition Facility (NIF) core diagnostic instrument has been designed and will be fabricated to record x-ray spectra in the 1.1-20.1 keV energy range. The High-Energy Electronic X-Ray (HENEX) instrument has four reflection crystals with overlapping coverage of 1.1-10.9 keV and one transmission crystal covering 8.6-20.1 keV. The spectral resolving power varies from approximately 2000 at low energies to 300 at 20 keV. The spectrum produced by each crystal is recorded by a modified commercial dental x-ray charge coupled device detector with a dynamic range of at least 2500. (C) 2001 American Institute of Physics. C1 USN, Res Lab, Div Space Sci, Washington, DC 20375 USA. Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. SFA Inc, Largo, MD 20899 USA. RP Seely, J (reprint author), USN, Res Lab, Div Space Sci, Washington, DC 20375 USA. NR 11 TC 12 Z9 15 U1 0 U2 3 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0034-6748 J9 REV SCI INSTRUM JI Rev. Sci. Instrum. PD JUN PY 2001 VL 72 IS 6 BP 2562 EP 2565 DI 10.1063/1.1370557 PG 4 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA 435EJ UT WOS:000168864200007 ER PT J AU Weinheimer, J Ahmad I Herzog, O Kunze, HJ Bertschinger, G Biel, W Borchert, G Bitter, M AF Weinheimer, J Ahmad, I Herzog, O Kunze, HJ Bertschinger, G Biel, W Borchert, G Bitter, M TI High-resolution x-ray crystal spectrometer/polarimeter at torus experiment for technology oriented research-94 SO REVIEW OF SCIENTIFIC INSTRUMENTS LA English DT Article ID DIELECTRONIC SATELLITE SPECTRUM; HELIUM-LIKE ARGON; TOKAMAK PLASMAS; TRANSITIONS; IONS; TEMPERATURE; EXCITATION; DEPENDENCE; RATES; LINES AB A high-resolution x-ray polarimeter has been installed at the torus experiment for technology oriented research (TEXTOR-94). The instrument consists of two spectrometers in Johann geometry, utilizing the dependence of Bragg reflection on the polarization. The dispersion plane of the so-called horizontal spectrometer coincides with the midplane of the tokamak, whereas the dispersion plane of the so-called vertical spectrometer lies perpendicular to the midplane of the tokamak. Both spectrometers operate with cylindrically bent quartz crystals of dimensions 153 mmx38 mmx0.7 mm with a 2d spacing of 4.9130 Angstrom. The radii of curvature of the horizontal and vertical spectrometer crystals are 3820 mm and 4630 mm, respectively. The detectors are multiwire proportional counters having a large entrance window of 180 mmx90 mm, with a high count rate capability of up to 2.5x10(5) photons/s, and a spatial resolution of 0.4-0.65 mm, depending on the count rate. The unique data acquisition system makes it possible to record up to 8192 spectra per TEXTOR-94 discharge to study fast events and impurity transport. The instruments are sensitive to spurious amounts of argon in hydrogen or deuterium discharges and aim for x-ray polarization measurements and other core plasma diagnostics like electron temperature, ion temperature, plasma rotation, impurity transport, and relative abundance of Ar(15+)/Ar(16+). The first measurements of toroidal rotation speed, ion and electron temperatures show a very good agreement with charge exchange recombination spectroscopy (XRS) and electron cyclotron emission (ECE) diagnostics available at TEXTOR-94. The measured values of the ratio Ar(15+)/Ar(16+) are higher than that predicted from coronal equilibrium. The ratio depends strongly upon the electron density both for ohmic and neutral beam injection cases. This suggests that the charge state distribution is also dependent on diffusion and charge exchange processes in the plasmas. (C) 2001 American Institute of Physics. C1 Forschungszentrum Julich, EURATOM Assoc, Inst Plasmaphys, D-52425 Julich, Germany. Ruhr Univ Bochum, Inst Expt Phys 5, D-44780 Bochum, Germany. Forschungszentrum Julich, Inst Kernphys, D-52425 Julich, Germany. Princeton Univ, Princeton Plasma Phys Lab, Princeton, NJ 08543 USA. RP Weinheimer, J (reprint author), Forschungszentrum Julich, EURATOM Assoc, Inst Plasmaphys, Trilateral Euregio Cluster, D-52425 Julich, Germany. EM g.bertschinger@fz-juelich.de NR 29 TC 19 Z9 24 U1 0 U2 4 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0034-6748 J9 REV SCI INSTRUM JI Rev. Sci. Instrum. PD JUN PY 2001 VL 72 IS 6 BP 2566 EP 2574 DI 10.1063/1.1370558 PG 9 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA 435EJ UT WOS:000168864200008 ER PT J AU Pincosy, PA Back, N Bergstrom, PM Chen, YJ Poulsen, P AF Pincosy, PA Back, N Bergstrom, PM Chen, YJ Poulsen, P TI Multiple pulse electron beam converter design for high power radiography SO REVIEW OF SCIENTIFIC INSTRUMENTS LA English DT Article AB The typical response of the x-ray converter material to the passage of a high-powered relativistic electron beam is vaporization and rapid dispersal. The effect of this dispersal on subsequent pulses for multi-pulse radiography is the collective effects on the propagation of the electron beam through the expanding plasma and the reduced number of electron to photon interactions. Thus, for the dual-axis radiographic hydrodynamic test facility, the converter material must either be replaced or confined long enough to accommodate the entire pulse train. Typically the 1-mm-thick high Z and full density converter material is chosen to give peak dose and minimum radiographic spot. For repeated pulses we propose a modified converter, constructed of either low density, high Z material in the form of foam or of foils spaced over ten times the axial thickness of the standard 1 mm converter. The converter material is confined within a tube to impede outward motion in radius outside the beam interaction region. We report single-pulse experiments which measure the dose and spot size produced by the modified converter and compare them to similar measurements made by the standard converter. For multiple pulses over a microsecond time scale, we calculate the radial and axial hydrodynamic flow to study the material reflux into the converter volume and the resultant density decrease as the electron beam energy is deposited. Both the electron transport through the expanding low density plasma and beam in the higher density material are modeled. The x-ray source dose and spot size are calculated to evaluate the impact of the changing converter material density distribution on the radiographic spot size and dose. The results indicate that a multiple-pulse converter design for three or four high-power beam pulses is feasible. (C) 2001 American Institute of Physics. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Pincosy, PA (reprint author), Univ Calif Lawrence Livermore Natl Lab, L99 PO 808, Livermore, CA 94550 USA. NR 12 TC 1 Z9 8 U1 1 U2 2 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0034-6748 J9 REV SCI INSTRUM JI Rev. Sci. Instrum. PD JUN PY 2001 VL 72 IS 6 BP 2599 EP 2604 DI 10.1063/1.1369628 PG 6 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA 435EJ UT WOS:000168864200012 ER PT J AU Dadashev, A Pasternak, MP Rozenberg, GK Taylor, RD AF Dadashev, A Pasternak, MP Rozenberg, GK Taylor, RD TI Applications of perforated diamond anvils for very high-pressure research SO REVIEW OF SCIENTIFIC INSTRUMENTS LA English DT Article ID CELL AB To reduce the large absorption effect in diamond anvil pressure cells for soft x rays, perforated anvils employed as diamond-backing plates (DBPs) used in conjunction with miniature anvils (MAs) made of 1/100 carat diamonds were tested for high-pressure efficacy. Static pressures beyond 100 GPa were generated using a piston/cylinder cell having 0.2 mm culets. Tests were carried out in 0.1 mm cavities drilled in a Re gasket, using Ar samples and ruby chips for manometry. Except for a single failure of a 0.3 mm culet MA, no damage was detected in the DBPs drilled with truncated conical holes tapering from 0.3 mm to 1, 1.5, and 2 mm diameter. Another arrangement in which one anvil was partially drilled leaving a 0.5 mm thick wall behind the culet achieved 100 GPa. Detailed discussions are given concerning the benefits of the DBP/MA cells for high-pressure studies with soft x rays and for background reduction in Raman, IR, UV, and Fe-57 Mossbauer spectroscopies. (C) 2001 American Institute of Physics. C1 Tel Aviv Univ, Sch Phys & Astron, IL-69978 Tel Aviv, Israel. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Dadashev, A (reprint author), Tel Aviv Univ, Sch Phys & Astron, IL-69978 Tel Aviv, Israel. NR 6 TC 57 Z9 57 U1 0 U2 7 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0034-6748 J9 REV SCI INSTRUM JI Rev. Sci. Instrum. PD JUN PY 2001 VL 72 IS 6 BP 2633 EP 2637 DI 10.1063/1.1370561 PG 5 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA 435EJ UT WOS:000168864200018 ER PT J AU Christen, HM Silliman, SD Harshavardhan, KS AF Christen, HM Silliman, SD Harshavardhan, KS TI Continuous compositional-spread technique based on pulsed-laser deposition and applied to the growth of epitaxial films SO REVIEW OF SCIENTIFIC INSTRUMENTS LA English DT Article ID OXIDE THIN-FILMS; TRANSPARENT CONDUCTING OXIDE; COMBINATORIAL SYNTHESIS; ABLATION; FABRICATION; DISCOVERY; MBE AB A novel continuous-compositional-spread (CCS) technique based on the nonuniformity of the deposition rate typically observed in pulsed-laser deposition (PLD) is introduced. Using rapid (submonolayer) sequential deposition of the phase spread's constituents, intermixing of the constituents occurs on the atomic scale during the growth process. Therefore, a pseudobinary or pseudoternary phase diagram is deposited without the requirement of a postanneal. The approach uses the spatial variations in the deposition rate naturally occurring in PLD; therefore, there is no need for the masks typically used in combinatorial techniques. Consequently, combinatorial materials synthesis can be carried out under optimized film growth conditions (for example, complex oxides can be grown at high temperature). Additionally, lifting the need for postannealing renders this method applicable to heat-sensitive materials and substrates (e.g., films of transparent oxides on polymer substrates). PLD CCS thus offers an interesting alternative to traditional "combi" for situations where the number of constituents is limited, but the process variables are of critical importance. Additionally, the approach benefits from all the advantages of PLD, particularly the flexibility and the possibility to work with targets of relatively small size. Composition determination across the sample and mapping of physical properties onto the ternary phase diagram is achieved via a simple algorithm using the parameters that describe the deposition-rate profiles. Experimental verification using energy-dispersive x-ray spectroscopy and Rutherford backscattering spectroscopy measurements demonstrates the excellent agreement between the predicted and the calculated composition values. Results are shown for the high-temperature growth of crystalline perovskites [including (Ba,Sr)TiO3 and the formation of a metastable alloy between SrRuO3 and SrSnO3] and the room-temperature growth of transparent conducting oxides. (C) 2001 American Institute of Physics. C1 Neocera Inc, Beltsville, MD 20705 USA. RP Christen, HM (reprint author), Oak Ridge Natl Lab, Div Solid State, POB 2008, Oak Ridge, TN 37831 USA. RI Christen, Hans/H-6551-2013 OI Christen, Hans/0000-0001-8187-7469 NR 31 TC 42 Z9 43 U1 4 U2 30 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0034-6748 J9 REV SCI INSTRUM JI Rev. Sci. Instrum. PD JUN PY 2001 VL 72 IS 6 BP 2673 EP 2678 DI 10.1063/1.1374597 PG 6 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA 435EJ UT WOS:000168864200024 ER PT J AU Koga, T Zhou, SQ Chu, B Fulton, JL Yang, S Ober, CK Erman, B AF Koga, T Zhou, SQ Chu, B Fulton, JL Yang, S Ober, CK Erman, B TI High-pressure cell for simultaneous small-angle x-ray scattering and laser light scattering measurements SO REVIEW OF SCIENTIFIC INSTRUMENTS LA English DT Article ID SUPERCRITICAL CARBON-DIOXIDE; NEUTRON-SCATTERING; DIBLOCK COPOLYMER; POLY(METHYL METHACRYLATE); INDUCED MICELLIZATION; NONIONIC SURFACTANTS; POLY(VINYL ACETATE); MICROEMULSIONS; PLASTICIZATION; POLYMER AB A cell for in situ observation of self-assembled nanostructured materials in high-pressure fluids, including supercritical carbon dioxide, has been constructed and tested. The compact cell can be used for simultaneous small-angle x-ray scattering, laser light scattering, visual observation, and some other types of spectroscopic measurements. The light scattering plane is normal to the x-ray scattering plane with the optical axis and the x-ray axis being perpendicular to each other. The scattering is detected at the intersection of the light and x-ray beams, and thus one effectively probes the same scattering volume. Some preliminary experimental results for the micellar self-assembly of a fluorinated block copolymer in supercritical carbon dioxide are presented. (C) 2001 American Institute of Physics. C1 SUNY Stony Brook, Dept Chem, Stony Brook, NY 11794 USA. SUNY Stony Brook, Dept Mat Sci & Engn, Stony Brook, NY 11794 USA. Pacific NW Natl Lab, Environm & Hlth Sci Div, Richland, WA 99352 USA. Cornell Univ, Dept Mat Sci & Engn, Ithaca, NY 14853 USA. Sabanci Univ, Fac Engn & Nat Sci, TR-81474 Istanbul, Turkey. RP Chu, B (reprint author), SUNY Stony Brook, Dept Chem, Stony Brook, NY 11794 USA. EM bchu@notes.cc.sunysb.edu RI Koga, Tadanori/A-4007-2010; Yang, Shu/D-9758-2011; OI ERMAN, BURAK/0000-0002-2496-6059 NR 47 TC 11 Z9 11 U1 1 U2 6 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0034-6748 J9 REV SCI INSTRUM JI Rev. Sci. Instrum. PD JUN PY 2001 VL 72 IS 6 BP 2679 EP 2685 DI 10.1063/1.1372696 PG 7 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA 435EJ UT WOS:000168864200025 ER PT J AU Jusinski, LE Taatjes, CA AF Jusinski, LE Taatjes, CA TI Efficient and stable operation of an Ar+-pumped continuous-wave ring laser from 505-560 nm using a coumarin laser dye SO REVIEW OF SCIENTIFIC INSTRUMENTS LA English DT Article ID STABILITY AB A coumarin laser dye has been found to produce efficiencies and lifetimes comparable to those of the rhodamines. Coumarin 521 (coumarin 334) produces up to 400 mW of single frequency light (frequency width <1 MHz) at 520 nm in a ring laser when excited with 2.4 W of 457.9 nm light from an Ar+ ion laser. Operation with a 488 nm pump shows slightly lower efficiency. Dye lifetime to 75% full power has exceeded 1000 W h over a period of several months. Methanol and ethylene glycol are the only solvents required. This dye operates in a portion of the tuning range of a continuous-wave ring dye laser which is otherwise extremely difficult to access using an argon ion laser as the pump source. Used in conjunction with an external buildup cavity, 8-12 mW of 258 nm light is reliably produced for weeks at a time. (C) 2001 American Institute of Physics. C1 Sandia Natl Labs, Combust Res Facil, Livermore, CA 94551 USA. RP Jusinski, LE (reprint author), Sandia Natl Labs, Combust Res Facil, Mail Stop 9055, Livermore, CA 94551 USA. NR 8 TC 17 Z9 17 U1 0 U2 4 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0034-6748 J9 REV SCI INSTRUM JI Rev. Sci. Instrum. PD JUN PY 2001 VL 72 IS 6 BP 2837 EP 2838 DI 10.1063/1.1369626 PG 2 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA 435EJ UT WOS:000168864200053 ER PT J AU Bourgade, JL Villette, B Bocher, JL Boutin, JY Chiche, S Dague, N Gontier, D Jadaud, JP Savale, B Wrobel, R Turner, RE AF Bourgade, JL Villette, B Bocher, JL Boutin, JY Chiche, S Dague, N Gontier, D Jadaud, JP Savale, B Wrobel, R Turner, RE TI DMX: An absolutely calibrated time resolved broadband soft x-ray spectrometer designed for MJ class laser produced plasmas (vol 72, pg 1173, 2001) SO REVIEW OF SCIENTIFIC INSTRUMENTS LA English DT Correction C1 CEA, DAM, F-91680 Bruyeres Le Chatel, France. Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Bourgade, JL (reprint author), CEA, DAM, BP 12, F-91680 Bruyeres Le Chatel, France. NR 1 TC 1 Z9 1 U1 0 U2 4 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0034-6748 J9 REV SCI INSTRUM JI Rev. Sci. Instrum. PD JUN PY 2001 VL 72 IS 6 BP 2846 EP 2846 DI 10.1063/1.1372175 PG 1 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA 435EJ UT WOS:000168864200056 ER PT J AU Burger, J Gaines, KF Gochfeld, M AF Burger, J Gaines, KF Gochfeld, M TI Ethnic differences in risk from Mercury among Savannah River fishermen SO RISK ANALYSIS LA English DT Article DE risk assessment; fish; fishing; fish consumption; mercury; Savannah River Site ID SELF-CAUGHT FISH; FOOD-CONSUMPTION; LARGEMOUTH BASS; HUMAN EXPOSURE; METHYLMERCURY; BENEFITS; PEOPLE; DISTRIBUTIONS; FLORIDA; PROGRAM AB Fishing plays an important role in people's lives and contaminant levels in fish are a public health concern. Many states have issued consumption advisories; South Carolina and Georgia have issued them for the Savannah River based on mercury and radionuclide levels. This study examined ethnic differences in risk from mercury exposure among people consuming fish from the Savannah River, based on site-specific consumption patterns and analysis of mercury in fish. Among fish, there were significant interspecies differences in mercury levels, and there were ethnic differences in consumption patterns. Two methods of examining risk are presented: (1) Hazard Index (HI), and (2) estimates of how much and how often people of different body mass can consume different species of fish. Blacks consumed more fish and had higher HIs than Whites. Even at the median consumption, the HI for Blacks exceeded 1.0 for bass and bowfin, and, at the 75th percentile of consumption, the HI exceeded 1.0 for almost all species. At the White male median consumption, noHI exceeded 1, but for the 95th percentile consumer, the HI exceeded 1.0 almost regardless of which species were eaten. Although females consumed about two thirds the quantity of males, HIs exceeded 1 for most Black females and for White females at or above the 75th percentile of consumption. Thus, close to half of the Black fishermen were eating enough Savannah River fish to exceed HI = 1. Caution must be used in evaluating an HI because the RfDs were developed to protect the most vulnerable individuals. The percentage of each fish species tested that exceeded the maximum permitted limits of mercury in fish was also examined. Over 80% of bowfin, 38% of bass, and 21% of pickerel sampled exceeded 0.5 ppm. The risk methodology is applicable anywhere that comparable data can be obtained. The risk estimates are representative for fishermen along the Savannah River, and are not necessarily for the general populations. C1 Rutgers State Univ, Div Life Sci, Nelson Biol Lab, Piscataway, NJ 08854 USA. Environm & Occupat Hlth Sci Inst, Piscataway, NJ USA. Consortium Risk Evaluat Stakeholder Participat, Piscataway, NJ USA. Univ Georgia, Savannah River Ecol Lab, Aiken, SC 29802 USA. Univ Med & Dent New Jersey, Robert Wood Johnson Med Sch, Piscataway, NJ 08854 USA. RP Burger, J (reprint author), Rutgers State Univ, Div Life Sci, Nelson Biol Lab, 604 Allison Rd, Piscataway, NJ 08854 USA. FU NIEHS NIH HHS [ESO 5022] NR 80 TC 80 Z9 84 U1 3 U2 8 PU BLACKWELL PUBL LTD PI OXFORD PA 108 COWLEY RD, OXFORD OX4 1JF, OXON, ENGLAND SN 0272-4332 J9 RISK ANAL JI Risk Anal. PD JUN PY 2001 VL 21 IS 3 BP 533 EP 544 DI 10.1111/0272-4332.213130 PG 12 WC Public, Environmental & Occupational Health; Mathematics, Interdisciplinary Applications; Social Sciences, Mathematical Methods SC Public, Environmental & Occupational Health; Mathematics; Mathematical Methods In Social Sciences GA 468DB UT WOS:000170741900013 PM 11572431 ER PT J AU Burger, J Gaines, KF Peles, JD Stephens, WL Boring, CS Brisbin, IL Snodgrass, J Bryan, AL Smith, MH Gochfeld, M AF Burger, J Gaines, KF Peles, JD Stephens, WL Boring, CS Brisbin, IL Snodgrass, J Bryan, AL Smith, MH Gochfeld, M TI Radiocesium in fish from the Savannah River and Steel Creek: Potential food chain exposure to the public SO RISK ANALYSIS LA English DT Article DE radiocesium; fish; food chain; risk; predators; environmental hazards; fish consumption ID LARGEMOUTH BASS; CHERNOBYL; RESERVOIR; CS-137; SITE; CESIUM-137; SEDIMENTS; RISK; BIOACCUMULATION; RADIONUCLIDES AB This study examined radiocesium (Cs-137) levels in fish from the vicinity of the Department of Energy's Savannah River Site (SRS), a former nuclear weapons production facility in South Carolina. Fish from the Savannah River were sampled above (upstream), along, and below (downstream) the SRS, and from Steel Creek, a tributary that runs through the SRS. There was some off-site contamination of Cs-137 in the Savannah River watershed due to low-level releases from past nuclear production on the SRS. The null hypotheses tested were that there would be no differences Cs-137 levels as a, function of location along the river, and between species collected from the river and from Steel Creek on the SRS. For six of eight species of fish collected from the Savannah River, there were no differences in Cs-137 levels in muscle from fish collected above, along, or below the SRS; exceptions were bowfin and shellcracker. Fish collected from Steel Creek had significantly higher levels (by about an order of magnitude) of Cs-137 in muscle tissue than fish collected in the Savannah River. However, no fish from either Steel Creek or the Savannah River had Cs-137 levels above the European Economic Community limit for fresh meat of 0.6 Bq/g. Lifetime cancer risk was calculated using the cancer slope factor of 3.2 X 10(-11)/pCi, and various fish consumption scenarios reflecting actual data from Savannah River fishermen. Using mean Cs-137 concentrations and median fish consumption for 70 years for Black males-the group with the highest consumption-the excess lifetime risk associated with the eight species of fish in the Savannah River ranged from 9.0 x 10(-7) to 1.0 X 10(-5). The same calculation for fish from Steel Creek gave risk estimates from 1.4 to 8.0 X 10(-5). The 95% level for consumption by Blacks, however, was about 70 kg/year. Black fishermen consuming that amount of bass from Steel Creek would sustain a lifetime risk of 3.1 X 10(-4),whereas the same consumption of Savannah River bass would yield a risk estimate of 1.5 X 10(-5). C1 Rutgers State Univ, Div Life Sci, Piscataway, NJ 08854 USA. Consortium Risk evaluat Stakeholder Participat, Environm & Occupat Hlth Sci Inst, Piscataway, NJ USA. Savannah River Ecol Lab, Aiken, SC 29802 USA. Penn State Univ, McKeesport, PA USA. Towson State Univ, Dept Biol, Towson, MD USA. Univ Med & Dent New Jersey, Robert Wood Johnson Med Sch, Piscataway, NJ 08854 USA. RP Burger, J (reprint author), Rutgers State Univ, Div Life Sci, 604 Allison Rd,Nelson Hall, Piscataway, NJ 08854 USA. RI Snodgrass, Joel/C-5288-2016 NR 48 TC 22 Z9 23 U1 2 U2 8 PU BLACKWELL PUBL LTD PI OXFORD PA 108 COWLEY RD, OXFORD OX4 1JF, OXON, ENGLAND SN 0272-4332 J9 RISK ANAL JI Risk Anal. PD JUN PY 2001 VL 21 IS 3 BP 545 EP 559 DI 10.1111/0272-4332.213131 PG 15 WC Public, Environmental & Occupational Health; Mathematics, Interdisciplinary Applications; Social Sciences, Mathematical Methods SC Public, Environmental & Occupational Health; Mathematics; Mathematical Methods In Social Sciences GA 468DB UT WOS:000170741900014 PM 11572432 ER PT J AU Kelley, AM Michalet, X Weiss, S AF Kelley, AM Michalet, X Weiss, S TI Chemical physics - Single-molecule spectroscopy comes of age SO SCIENCE LA English DT Editorial Material ID ROOM-TEMPERATURE C1 Kansas State Univ, Dept Chem, Manhattan, KS 66506 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Biophys Sci Div, Berkeley, CA 94720 USA. RP Kelley, AM (reprint author), Kansas State Univ, Dept Chem, Manhattan, KS 66506 USA. RI weiss, shimon/B-4164-2009; Michalet, Xavier/A-9704-2009 OI weiss, shimon/0000-0002-0720-5426; Michalet, Xavier/0000-0001-6602-7693 NR 19 TC 35 Z9 38 U1 0 U2 7 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 USA SN 0036-8075 J9 SCIENCE JI Science PD JUN 1 PY 2001 VL 292 IS 5522 BP 1671 EP 1672 PG 2 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 438AP UT WOS:000169031800032 PM 11387465 ER PT J AU Sonier, JE Brewer, JH Kiefl, RF Miller, RI Morris, GD Stronach, CE Gardner, JS Dunsiger, SR Bonn, DA Hardy, WN Liang, R Heffner, RH AF Sonier, JE Brewer, JH Kiefl, RF Miller, RI Morris, GD Stronach, CE Gardner, JS Dunsiger, SR Bonn, DA Hardy, WN Liang, R Heffner, RH TI Anomalous weak magnetism in superconducting YBa2Cu3O6+x SO SCIENCE LA English DT Article ID OXYGEN-DEFICIENT YBA2CU3OX; COPPER-OXIDE METALS; SINGLE-CRYSTALS; POSITIVE MUON; PHASE; RESONANCE; BEHAVIOR; SYSTEM; SITES AB For some time now, there has been considerable experimental and theoretical effort to understand the role of the normal-state "pseudogap" phase in underdoped high-temperature cuprate superconductors. Recent debate has centered on the question of whether the pseudogap is independent of superconductivity. We provide evidence from zero-field muon spin relaxation measurements in YBa2Cu3O6+x for the presence of small spontaneous static magnetic fields of electronic origin intimately related to the pseudogap transition. Our most significant finding is that, for optimal doping, these weak static magnetic fields appear well below the superconducting transition temperature. The two compositions measured suggest the existence of a quantum critical point somewhat above optimal doping. C1 Simon Fraser Univ, Dept Phys, Burnaby, BC V5A 1S6, Canada. Univ British Columbia, Dept Phys & Astron, Vancouver, BC V6T 1Z1, Canada. TRIUMF, Vancouver, BC V6T 2A3, Canada. Virginia State Univ, Dept Phys, Petersburg, VA 23806 USA. Natl Res Council, Chalk River, ON K0J 1P0, Canada. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Sonier, JE (reprint author), Simon Fraser Univ, Dept Phys, Burnaby, BC V5A 1S6, Canada. RI Gardner, Jason/A-1532-2013 NR 31 TC 83 Z9 83 U1 1 U2 10 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 JUN 1 PY 2001 VL 292 IS 5522 BP 1692 EP 1695 DI 10.1126/science.1060844 PG 6 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 438AP UT WOS:000169031800037 PM 11387468 ER PT J AU LeGore, LJ Lad, RJ Vetelino, JF Frederick, BG Kenik, EA AF LeGore, LJ Lad, RJ Vetelino, JF Frederick, BG Kenik, EA TI Aggregation and sticking probability of gold on tungsten trioxide films SO SENSORS AND ACTUATORS B-CHEMICAL LA English DT Article; Proceedings Paper CT 8th International Meeting on Chemical Sensors (IMCS-8) CY JUL 02-05, 2000 CL BASEL, SWITZERLAND DE tungsten trioxide; gold catalyst; particle coalescence; gas sensors ID ISLAND GROWTH-KINETICS; SEMICONDUCTOR GAS SENSORS; ULTRATHIN METAL-FILMS; VAPOR-DEPOSITION; SURFACE; CLUSTERS; SCATTERING; MICROSCOPY; MORPHOLOGY; TIO2(110) AB Both scanning electron microscopy (SEM) and transmission electron microscopy (TEM) images show that gold layers, 0.8-3.2 nm thick, deposited on WO3 films aggregate into particles at temperatures above 400 degreesC. The particles increase in size while the number density decreases over time. Particle size distributions indicate that the growth mechanism is coalescence due to island mobility rather than Ostwald ripening. Both SEM and X-ray photoemission spectroscopy (XPS) analysis indicate that the amount of gold deposited on the surface is approximately 50% of the value as determined by the quartz crystal monitor (QCM) during deposition. This difference is believed to be due to a low initial sticking probability of gold on the WO3 surface during deposition. Finding means to create and stabilize metal particles of the optimum size remains a problem in the fields of catalysis and gas sensors. (C) 2001 Elsevier Science B.V. All rights reserved. C1 Univ Maine, Surface Sci & Technol Lab, Orono, ME 04469 USA. Oak Ridge Natl Lab, Div Met & Ceram, Oak Ridge, TN 37831 USA. RP LeGore, LJ (reprint author), Univ Maine, Surface Sci & Technol Lab, Orono, ME 04469 USA. RI Lad, Robert/G-1669-2014 NR 38 TC 11 Z9 11 U1 0 U2 9 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 JUN 1 PY 2001 VL 76 IS 1-3 BP 373 EP 379 DI 10.1016/S0925-4005(01)00638-4 PG 7 WC Chemistry, Analytical; Electrochemistry; Instruments & Instrumentation SC Chemistry; Electrochemistry; Instruments & Instrumentation GA 445EC UT WOS:000169444300062 ER PT J AU Datskos, PG Sepaniak, MJ Tipple, CA Lavrik, N AF Datskos, PG Sepaniak, MJ Tipple, CA Lavrik, N TI Photomechanical chemical microsensors SO SENSORS AND ACTUATORS B-CHEMICAL LA English DT Article; Proceedings Paper CT 8th International Meeting on Chemical Sensors (IMCS-8) CY JUL 02-05, 2000 CL BASEL, SWITZERLAND DE microcantilevers; microsensors; trinitrotoluene (TNT) ID ATOMIC FORCE MICROSCOPE; RESONATING MICROCANTILEVERS; CANTILEVER ARRAY; ARTIFICIAL NOSE; SENSORS; SURFACE; STRESS; RESOLUTION; SILICON; MICROBALANCE AB Recently, there has been an increasing demand to perform real-time in situ chemical detection of hazardous materials, contraband chemicals, and explosive chemicals. The advent of inexpensive mass produced MEMS (microelectromechanical systems) devices has enabled the use of various microstructures for chemical detection. For example, microcantilevers were found to respond to chemical stimuli by undergoing changes in their bending and resonance frequency even when a small number of molecules adsorb on their surface. In our present studies, we extended this concept by studying changes in both the adsorption-induced stress and photo-induced stress as target chemicals adsorb or desorb on the surface of microcantilevers. We demonstrate that photo-induced bending of microcantilevers depends on the number of absorbed molecules on their surface. On the other hand, microcantilevers that have undergone photo-induced bending will adsorb a different number of guest molecules. Depending on the photon wavelength and microcantilever material, the microcantilever can be made to bend by expanding or contracting a surface layer on one of its sides, unequally. Coating the surface of the microstructure with different materials can provide chemical specificity for the target chemicals. However, by choosing a handful of different photon wavelengths, tunable chemical selectivity can be achieved due to differentiated photo-induced response without the need for multiple chemical coatings. We will present and discuss our results on diisopropyl methyl phosphonate (DIMP), trinitrotoluene (TNT), two isomers of dimethylnaphthalene (DMN), tetrachloroethylene (TCE) and trichloroethylene (TRCE). (C) 2001 Elsevier Science B.V. All rights reserved. C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. Univ Tennessee, Knoxville, TN 37996 USA. RP Datskos, PG (reprint author), Oak Ridge Natl Lab, POB 2008,1 Bear Creek Rd, Oak Ridge, TN 37831 USA. RI Lavrik, Nickolay/B-5268-2011 OI Lavrik, Nickolay/0000-0002-9543-5634 NR 42 TC 45 Z9 48 U1 0 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 JUN 1 PY 2001 VL 76 IS 1-3 BP 393 EP 402 DI 10.1016/S0925-4005(01)00647-5 PG 10 WC Chemistry, Analytical; Electrochemistry; Instruments & Instrumentation SC Chemistry; Electrochemistry; Instruments & Instrumentation GA 445EC UT WOS:000169444300065 ER PT J AU Sohn, H Farrar, CR AF Sohn, H Farrar, CR TI Damage diagnosis using time series analysis of vibration signals SO SMART MATERIALS & STRUCTURES LA English DT Article; Proceedings Paper CT European COST F3 Conference on System Identification and Structural Health Monitoring CY JUN, 2000 CL MADRID, SPAIN SP European COST F3 AB A novel time series analysis is presented to locate damage sources in a mechanical system, which is running in various operational environments. The source of damage is located by solely analyzing the acceleration time histories recorded from a structure of interest. First, a data normalization procedure is proposed. This procedure selects a reference signal that is 'closest' to a newly obtained signal from an ensemble of signals recorded when the structure is undamaged. Second, a two-stage prediction model (combining auto-regressive (AR) and auto-regressive with exogenous inputs (ARX) techniques) is constructed from the selected reference signal. Then, the residual. error, which is the difference between the actual acceleration measurement for the new signal and the prediction obtained from the AR-ARX model developed from the reference signal, is defined as the damage-sensitive feature. This approach is based on the premise that if there were damage in the structure, the prediction model previously identified using the undamaged time history would not be able to reproduce the newly obtained time series measured from the damaged structure. Furthermore, the increase in residual errors would be maximized at the sensors instrumented near the actual damage locations. The applicability of this approach is demonstrated using acceleration time histories obtained from an eight degrees-of-freedom mass-spring system. C1 Univ Calif Los Alamos Natl Lab, Engn Anal Grp, ESA EA, Los Alamos, NM 87545 USA. RI Farrar, Charles/C-6954-2012 NR 10 TC 212 Z9 230 U1 5 U2 24 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0964-1726 J9 SMART MATER STRUCT JI Smart Mater. Struct. PD JUN PY 2001 VL 10 IS 3 BP 446 EP 451 DI 10.1088/0964-1726/10/3/304 PG 6 WC Instruments & Instrumentation; Materials Science, Multidisciplinary SC Instruments & Instrumentation; Materials Science GA 453FY UT WOS:000169906900005 ER PT J AU Tonn, BE Zambrano, P Moore, S AF Tonn, BE Zambrano, P Moore, S TI Community networks or networked communities? SO SOCIAL SCIENCE COMPUTER REVIEW LA English DT Article DE community networking; social capital; public Web sites; government services AB The article provides an overview of the state of the art in community networks. Forty community networks were reviewed. A protocol was developed to guide the evaluation of each site. The protocol covered the types of information currently provided and whether the network contributes to the social capital of the community. It was found that communities are now served by several types of Web sites: nonprofit community networks, those administered by local governments, and various commercial sites. It does not appear that either individually or in combination the Web sites are working to strengthen the social capital of the communities they serve. It is recommended that a community's information networking organizations work together to provide integrated resources and programs that foster community dialogue and help people better meet their citizenship responsibilities, as well as up-to-date information on community events and real-time information about traffic, weather, and the like. C1 Univ Tennessee, Dept Urban & Reg Planning, Knoxville, TN 37996 USA. Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Tonn, BE (reprint author), Univ Tennessee, Dept Urban & Reg Planning, Knoxville, TN 37996 USA. NR 25 TC 11 Z9 11 U1 3 U2 7 PU SAGE PUBLICATIONS INC PI THOUSAND OAKS PA 2455 TELLER RD, THOUSAND OAKS, CA 91320 USA SN 0894-4393 J9 SOC SCI COMPUT REV JI Soc. Sci. Comput. Rev. PD SUM PY 2001 VL 19 IS 2 BP 201 EP 212 PG 12 WC Computer Science, Interdisciplinary Applications; Information Science & Library Science; Social Sciences, Interdisciplinary SC Computer Science; Information Science & Library Science; Social Sciences - Other Topics GA 422XV UT WOS:000168145300006 ER PT J AU Fong, BH Hurricane, OA Cowley, SC AF Fong, BH Hurricane, OA Cowley, SC TI Equilibrium and stability of prominence flux ropes SO SOLAR PHYSICS LA English DT Article ID FREE CYLINDRICAL EQUILIBRIA; IDEAL MAGNETOHYDRODYNAMICS; SOLAR CORONA; INSTABILITIES AB Realistic models of solar prominence flux ropes are numerically constructed. The models are in 2.5 dimensions, including the effects of non-isothermal temperature, density and gravity, and pressure. Stability of the equilibria to pressure- and gravity-driven instabilities is numerically investigated, using the ballooning formalism of fusion plasma theory. The equilibrium models can become unstable to pressure- and gravity-driven modes at plasma parameters characteristic of prominences. C1 Natl Ctr Atmospher Res, Adv Study Program, Boulder, CO 80307 USA. Natl Ctr Atmospher Res, High Altitude Observ, Boulder, CO 80307 USA. Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. Univ Calif Los Angeles, Dept Phys & Astron, Los Angeles, CA 90095 USA. RP Fong, BH (reprint author), Natl Ctr Atmospher Res, Adv Study Program, POB 3000, Boulder, CO 80307 USA. NR 27 TC 14 Z9 14 U1 0 U2 1 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0038-0938 J9 SOL PHYS JI Sol. Phys. PD JUN PY 2001 VL 201 IS 1 BP 93 EP 117 DI 10.1023/A:1010301524783 PG 25 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 456DL UT WOS:000170067800007 ER PT J AU Merkulov, VI Lowndes, DH Baylor, LR Kang, S AF Merkulov, VI Lowndes, DH Baylor, LR Kang, S TI Field emission properties of different forms of carbon SO SOLID-STATE ELECTRONICS LA English DT Article DE field emission; diamond; amorphous carbon; carbon nanotubes and nanofibers; nanostructure ID DIAMOND-LIKE CARBON; NANOSTRUCTURED CARBON; ELECTRON-EMISSION; AMORPHOUS-CARBON; NANOTUBES; FILMS; ENERGY; EMITTERS; DISPLAY; GROWTH AB The results of field emission (FE) studies are reported for three different forms of carbon: smooth amorphous carbon (a-C) films with both low and high sp(3) content prepared by pulsed-laser deposition (PLD), nanostructured carbon prepared by hot-filament chemical-vapor deposition (HFCVD), and vertically aligned carbon nanofibers (VACNFs). The Studies reveal that smooth PLD carbon films are poor field emitters regardless of their sp(3) content. Conditioning of the films, which resulted in films' modification, was required to draw FE current and the emission turn-on fields were relatively high. In contrast, HFCVD carbon films exhibit very good FE properties, including low-emission turn-on fields, relatively high emission site density, and excellent durability. Finally, VACNFs also were found to possess quite promising FE properties that compete with those of HFCVD films. We believe that the latter two forms of carbon are among the most promising candidates for use as cold cathodes in commercial devices. (C) 2001 Elsevier Science Ltd. All rights reserved. C1 Oak Ridge Natl Lab, Div Solid State, Oak Ridge, TN 37831 USA. Univ Tennessee, Dept Phys & Astron, Knoxville, TN 37996 USA. RP Merkulov, VI (reprint author), Oak Ridge Natl Lab, Div Solid State, Bldg 3150,MS 6056, Oak Ridge, TN 37831 USA. NR 34 TC 16 Z9 18 U1 2 U2 5 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0038-1101 J9 SOLID STATE ELECTRON JI Solid-State Electron. PD JUN PY 2001 VL 45 IS 6 BP 949 EP 956 DI 10.1016/S0038-1101(01)00036-3 PG 8 WC Engineering, Electrical & Electronic; Physics, Applied; Physics, Condensed Matter SC Engineering; Physics GA 461VW UT WOS:000170385000018 ER PT J AU Vella, MC Reilly, M Brown, B AF Vella, MC Reilly, M Brown, B TI Conventional beamline implantation of decaborane SO SOLID STATE TECHNOLOGY LA English DT Article AB Low-energy boron implantation is a critical process for semiconductor doping today [1]. Decaborane has been shown to be an attractive alternative to monatomic boron for shallow junction formation. Motivated by the requirement for these ultra-shallow junctions, researchers have demonstrated the conventional application of decaborane beams. C1 Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. ElectroGraph Inc, Carlsbad, CA USA. ATMI Inc, Danbury, CT USA. RP Vella, MC (reprint author), Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. NR 7 TC 0 Z9 0 U1 0 U2 0 PU PENNWELL PUBL CO SOLID STATE TECHNOLOGY OFFICE PI NASHUA PA TEN TARA BLVD 5TH FLOOR, NASHUA, NH 03062-2801 USA SN 0038-111X J9 SOLID STATE TECHNOL JI Solid State Technol. PD JUN PY 2001 VL 44 IS 6 BP 77 EP + PG 3 WC Engineering, Electrical & Electronic; Physics, Applied; Physics, Condensed Matter SC Engineering; Physics GA 436VK UT WOS:000168956400010 ER PT J AU Yoon, S Malallah, AH Datta-Gupta, A Vasco, DW Behrens, RA AF Yoon, S Malallah, AH Datta-Gupta, A Vasco, DW Behrens, RA TI A multiscale approach to production-data integration using streamline models SO SPE JOURNAL LA English DT Article; Proceedings Paper CT 1999 SPE Annual Technical Conference and Exhibition CY OCT 03-06, 1999 CL HOUSTON, TEXAS SP Soc Petr Engineers ID CONJUGATE-GRADIENT; INVERSE PROBLEMS; LEAST-SQUARES AB We propose a multiscale approach to data integration that accounts for the varying resolving power of different data types from the very outset. Starting with a coarse description, we match the production response at the wells by recursively refining the reservoir grid. A multiphase streamline simulator is used for modeling fluid flow in the reservoir. The well data are then integrated using conventional, geostatistics, for example sequential simulation methods. There are several advantages to our proposed approach. First, we explicitly account for the resolution of the production response by refining the grid only up to a level sufficient to match the data, avoiding over-parameterization and incorporation of artificial regularization constraints. Second, production data are integrated at a coarse scale with fewer parameters, which makes the method significantly faster compared to direct fine-scale inversion of the production data. Third, decomposition of the inverse problem by scale greatly facilitates the convergence of iterative descent techniques to the global solution, particularly in the presence of multiple local minima. Finally, the streamline approach allows for parameter sensitivities to be computed analytically using a single simulation run, thus further enhancing the computational speed. The proposed approach has been applied to synthetic as well as field examples. The synthetic examples illustrate the validity of the approach and also address several key issues, such as convergence of the algorithm, computational efficiency, and advantages of the multiscale approach compared to conventional methods. The field example is from the Goldsmith San Andres Unit (GSAU) in west Texas and includes multiple patterns consisting of 11 injectors and 31 producers. Using well-log data and water-cut history from producing wells, we characterize the permeability distribution, thus demonstrating the feasibility of the proposed approach for large-scale field applications. C1 Reservoit Characterizat Res & Consulting Inc, Denver, CO USA. Texas A&M Univ, College Stn, TX 77843 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. Chevron Petr Technol Co, San Ramon, CA USA. RP Yoon, S (reprint author), Reservoit Characterizat Res & Consulting Inc, Denver, CO USA. RI Vasco, Donald/I-3167-2016 OI Vasco, Donald/0000-0003-1210-8628 NR 19 TC 20 Z9 21 U1 0 U2 2 PU SOC PETROLEUM ENG PI RICHARDSON PA 222 PALISADES CREEK DR,, RICHARDSON, TX 75080 USA SN 1086-055X J9 SPE J JI SPE J. PD JUN PY 2001 VL 6 IS 2 BP 182 EP 192 PG 11 WC Engineering, Petroleum SC Engineering GA 457JN UT WOS:000170133900008 ER PT J AU Chi, ZH Cullum, BM Stokes, DL Mobley, J Miller, GH Hajaligol, MR Vo-Dinh, T AF Chi, ZH Cullum, BM Stokes, DL Mobley, J Miller, GH Hajaligol, MR Vo-Dinh, T TI Laser-induced fluorescence studies of polycyclic aromatic hydrocarbons (PAH) vapors at high temperatures SO SPECTROCHIMICA ACTA PART A-MOLECULAR AND BIOMOLECULAR SPECTROSCOPY LA English DT Article DE laser-induced fluorescence; PAHs; high temperature; vapor; pyrene; anthracene ID MECHANISMS; SPECTRA; FLAMES; PYRENE AB In this work. we present the fluorescence spectra of anthracene and pyrene vapors at different elevated temperatures (from 150 to 650 degreesC) excited with the 337 nm line of a nitrogen laser. We describe the high temperature effects on the resulting spectral properties including spectral intensity, spectral bandwidth acid spectral shift. We found that the PAH fluorescence spectral bandwidths become very broad as the temperature increases. The broadening is mainly due to thermal vibrational sequence congestion. We also have found that the fluorescence intensity of pyrene vapor increases with increasing temperature, which results from the increase of the pyrene vapor absorption cross section at 337 nm. (C) 2001 Elsevier Science B.V. All rights reserved. C1 Oak Ridge Natl Lab, Adv Monitoring Dev Grp, Div Life Sci, Oak Ridge, TN 37831 USA. Philip Morris Inc, Res Ctr, Richmond, VA 23261 USA. RP Vo-Dinh, T (reprint author), Oak Ridge Natl Lab, Adv Monitoring Dev Grp, Div Life Sci, POB 2008, Oak Ridge, TN 37831 USA. NR 20 TC 18 Z9 18 U1 1 U2 8 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 1386-1425 J9 SPECTROCHIM ACTA A JI Spectroc. Acta Pt. A-Molec. Biomolec. Spectr. PD JUN PY 2001 VL 57 IS 7 BP 1377 EP 1384 DI 10.1016/S1386-1425(00)00479-0 PG 8 WC Spectroscopy SC Spectroscopy GA 441EK UT WOS:000169217900005 PM 11446693 ER PT J AU Mascarenhas, A Zhang, Y Verley, J Seong, MJ AF Mascarenhas, A Zhang, Y Verley, J Seong, MJ TI Overcoming limitations in semiconductor alloy design SO SUPERLATTICES AND MICROSTRUCTURES LA English DT Article DE isoelectronic impurity; co-doping; GaAs : N : Bi; GaP : N : Bi ID BAND-GAP; OPTICAL-TRANSITIONS; IMPURITY BAND; NITROGEN; GAAS1-XNX; GAAS; LUMINESCENCE; GAINNAS; ZNO AB The phenomenon of giant band gap 'bowing' recently observed in several III-V dilute nitride alloys is promising for increasing the flexibility in choice of semiconductor band gaps available for specified lattice constants. However, the poor electrical transport properties that these materials exhibit seriously limit their usefulness. It is proposed that these materials behave as heavily nitrogen-doped semiconductors rather than dilute nitride alloys and that the abnormal or irregular alloy behavior is associated with impurity band formation that manifests itself in the giant bowing and poor transport properties. The potential for regularizing the alloy behavior using isoelectronic co-doping is discussed. (C) 2001 Academic Press. C1 Natl Renewable Energy Lab, Golden, CO 80401 USA. RP Mascarenhas, A (reprint author), Natl Renewable Energy Lab, 1617 Cole Blvd, Golden, CO 80401 USA. RI Verley, Jason/C-2026-2008 OI Verley, Jason/0000-0003-2184-677X NR 42 TC 18 Z9 18 U1 0 U2 8 PU ACADEMIC PRESS LTD PI LONDON PA 24-28 OVAL RD, LONDON NW1 7DX, ENGLAND SN 0749-6036 J9 SUPERLATTICE MICROST JI Superlattices Microstruct. PD JUN PY 2001 VL 29 IS 6 BP 395 EP 404 DI 10.1006/spmi.2001.0984 PG 10 WC Physics, Condensed Matter SC Physics GA 460UY UT WOS:000170328000003 ER PT J AU Man, KL Altman, MS Poppa, H AF Man, KL Altman, MS Poppa, H TI Spin polarized low energy electron microscopy investigations of magnetic transitions in Fe/Cu(100) SO SURFACE SCIENCE LA English DT Article; Proceedings Paper CT 2nd LEEM/PEEM Workshop CY SEP 26-28, 2000 CL PARIS, FRANCE DE low-energy electron microscopy (LEEM); iron; copper; magnetic measurements ID FE FILMS; CURIE-TEMPERATURE; EPITAXIAL-GROWTH; FCC-FE; CU(100); IRON; SURFACE; W(110); ANTIFERROMAGNETISM; OSCILLATIONS AB Magnetic transitions in ultrathin Fe films on the Cu(1 0 0) surface have been studied with spin polarized low energy electron microscopy. By monitoring averaged image intensity oscillations and the evolution of magnetization and magnetic domain structure simultaneously and continuously during growth, magnetism and film thickness are correlated with unprecedented precision. The thickness range over which ferromagnetism exists in films grown at room temperature generally increases as the deposition rate is decreased. This trend is attributed to the influence of residual hydrogen. The two-dimensional Ising model with finite size scaling of the Curie temperature accurately describes the evolution of magnetization with increasing film thickness. (C) 2001 Elsevier Science B.V. All rights reserved. C1 Hong Kong Univ Sci & Technol, Dept Phys, Kowloon, Hong Kong, Peoples R China. Univ Calif Berkeley, Lawrence Berkeley Lab, Natl Ctr Electron Microscopy, Berkeley, CA 94720 USA. RP Hong Kong Univ Sci & Technol, Dept Phys, Kowloon, Hong Kong, Peoples R China. EM phaltman@ust.hk RI Man, Ka Lun, Michael /B-7639-2015 OI Man, Ka Lun, Michael /0000-0001-6043-3631 NR 36 TC 12 Z9 13 U1 0 U2 11 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0039-6028 EI 1879-2758 J9 SURF SCI JI Surf. Sci. PD JUN 1 PY 2001 VL 480 IS 3 BP 163 EP 172 DI 10.1016/S0039-6028(01)00831-7 PG 10 WC Chemistry, Physical; Physics, Condensed Matter SC Chemistry; Physics GA 442KY UT WOS:000169285800010 ER PT J AU Quitmann, C Flechsig, U Patthey, L Schmidt, T Ingold, G Howells, M Janousch, M Abela, R AF Quitmann, C Flechsig, U Patthey, L Schmidt, T Ingold, G Howells, M Janousch, M Abela, R TI A beamline for time resolved photoelectron microscopy on magnetic materials at the Swiss light source SO SURFACE SCIENCE LA English DT Article; Proceedings Paper CT 2nd LEEM/PEEM Workshop CY SEP 26-28, 2000 CL PARIS, FRANCE DE photoelectron spectroscopy; magnetic surfaces ID BESSY-II; RADIATION AB We describe the "Surface/Interface: Microscopy" beamline currently under construction at the Paul Scherrer Institut. This beamline will use a photoemission electron microscope to study the electronic and magnetic structure of materials. Its photon energy range will be 94-2000 eV. To allow time resolved measurements with millisecond resolution we use a new scheme allowing to switch the photon helicity optically without perturbing the electron orbit. Two identical elliptical insertion devices are placed behind each other in the same straight section. They can produce light with opposing helicities. These two sources are separated horizontally by introducing a small static parallel offset in the electron orbit. Switching between the two rays of opposite helicities is done mechanically at the horizontal focus behind the monochromator. The two sources are brought to overlap on the sample by slightly defocussing the refocussing mirror. A commercial microscope (Deltax similar to 20 nm resolution) is adapted to the synchrotron by various upgrades. These include a software combining microscope and beamline control, a computer controlled mechanical alignment system, a separate sample preparation chamber, and sample cooling using liquid nitrogen. The beamline will be available for user operation in 2002. (C) 2001 Elsevier Science B.V. All rights reserved. C1 Paul Scherrer Inst, Swiss Light Source, CH-5232 Villigen, Switzerland. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Quitmann, C (reprint author), Paul Scherrer Inst, Swiss Light Source, CH-5232 Villigen, Switzerland. RI Quitmann, Christoph/A-7047-2008; Janousch, Markus/B-3285-2010 NR 9 TC 39 Z9 39 U1 1 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0039-6028 J9 SURF SCI JI Surf. Sci. PD JUN 1 PY 2001 VL 480 IS 3 BP 173 EP 179 DI 10.1016/S0039-6028(01)00832-9 PG 7 WC Chemistry, Physical; Physics, Condensed Matter SC Chemistry; Physics GA 442KY UT WOS:000169285800011 ER PT J AU Hwu, Y Tsai, WL Lai, B Je, JH Fecher, GH Bertolo, M Margaritondo, G AF Hwu, Y Tsai, WL Lai, B Je, JH Fecher, GH Bertolo, M Margaritondo, G TI Using photoelectron emission microscopy with hard-X-rays SO SURFACE SCIENCE LA English DT Article; Proceedings Paper CT 2nd LEEM/PEEM Workshop CY SEP 26-28, 2000 CL PARIS, FRANCE DE photoelectron emission; X-ray absorption spectroscopy ID SYNCHROTRON-RADIATION; THIN-FILMS; SPECTROMICROSCOPY; CONTRAST; RESOLUTION; MEPHISTO; SURFACES; IMAGES AB We present several successful test cases of using photoelectron emission microscopy (PEEM) for photon energy up to 25 keV. First, the full extended X-ray absorption fine structure analysis was implemented in areas as small as 100 mum(2) for transition-metal K edge absorption spectra and, therefore, demonstrated the feasibility of combining structural and chemical analysis with hard-X-ray absorption spectroscopy with high lateral resolution. We also show that PEEM can be used in a transmission (radiography) mode as an imaging detector for hard-X-ray, This approach again leads to the unprecedented 0.3 mum lateral resolution, particularly critical for the use of coherence-based phase contrast techniques in real time X-ray radiology. (C) 2001 Elsevier Science B.V. All rights reserved. C1 Ecole Polytech Fed Lausanne, Inst Phys Appl, CH-1015 Lausanne, Switzerland. Acad Sinica, Inst Phys, Taipei, Taiwan. Argonne Natl Lab, Adv Photon Source, Argonne, IL 60439 USA. Pohang Univ Sci & Technol, Dept Mat Sci & Engn, Pohang, South Korea. Univ Mainz, Inst Phys, D-6500 Mainz, Germany. Sincrotrone Trieste SCpA, Trieste, Italy. RP Hwu, Y (reprint author), Ecole Polytech Fed Lausanne, Inst Phys Appl, CH-1015 Lausanne, Switzerland. RI Margaritondo, Giorgio/B-1367-2008; Fecher, Gerhard/H-2470-2011 NR 26 TC 13 Z9 15 U1 0 U2 5 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0039-6028 J9 SURF SCI JI Surf. Sci. PD JUN 1 PY 2001 VL 480 IS 3 BP 188 EP 195 DI 10.1016/S0039-6028(01)00834-2 PG 8 WC Chemistry, Physical; Physics, Condensed Matter SC Chemistry; Physics GA 442KY UT WOS:000169285800013 ER PT J AU Jin, Z Su, YX Duan, YX AF Jin, Z Su, YX Duan, YX TI A novel method for polyaniline synthesis with the immobilized horseradish peroxidase enzyme SO SYNTHETIC METALS LA English DT Article DE polyaniline synthesis; horseradish peroxidase; enzyme; hydrogen peroxide ID MOLECULAR-WEIGHT POLYANILINE; CONDUCTING POLYANILINE; FILMS; ACID; POLYMERS AB A novel method for the synthesis of a water-soluble polyaniline with the immobilized horseradish peroxidase (HRP) enzyme is presented. The enzyme HRP is immobilized on chitosan powder by a simple glutaraldehyde bridge method. The immobilized HRP is an effective catalyst for the oxidative polymerization of aniline in the presence of hydrogen peroxide at room temperature. The overall reaction is sensitive to solution pH and hydrogen peroxide concentration. The UV-VIS absorption spectra of the products are similar to that of polyaniline obtained with an HRP solution as a catalyst, and they display a distinct absorption peak at 750 nm at pH 4.0. The immobilized HRP is stable and remains active after being stored in pH 6.0 buffer solution at room temperature for more than 72 h. Published by Elsevier Science B.V. C1 Univ Calif Los Alamos Natl Lab, Chem Sci & Technol Div, Los Alamos, NM 87545 USA. RP Duan, YX (reprint author), Univ Calif Los Alamos Natl Lab, Chem Sci & Technol Div, CST-9,MS K-484, Los Alamos, NM 87545 USA. NR 25 TC 39 Z9 47 U1 1 U2 6 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0379-6779 J9 SYNTHETIC MET JI Synth. Met. PD JUN 1 PY 2001 VL 122 IS 2 BP 237 EP 242 DI 10.1016/S0379-6779(00)00287-3 PG 6 WC Materials Science, Multidisciplinary; Physics, Condensed Matter; Polymer Science SC Materials Science; Physics; Polymer Science GA 449FR UT WOS:000169674100002 ER PT J AU Qiao, ZJ AF Qiao, ZJ TI The r-matrix and an algebraic-geometric solution of the AKNS system SO THEORETICAL AND MATHEMATICAL PHYSICS LA English DT Article; Proceedings Paper CT 14th International Workshop on Nonlinear Evolution Equations and Dynamical Systems CY JUN 29-JUL 07, 2000 CL GOKOVA, TURKEY AB We construct an approach to finite-dimensional integrable systems with nonlinear evolution equations from the standpoint of the r-matrix and an algebraic-geometric solution, illustrating the method with the well-known AKNS equation. We present the r-matrix of the constrained AKNS flow and obtain the algebraic-geometric solution of the AKNS equation. C1 Univ Calif Los Alamos Natl Lab, Div Theoret, Los Alamos, NM USA. Fudan Univ, Inst Math, Shanghai 200433, Peoples R China. Univ Gesamthsch Kassel, Fachbereich Math 17, D-34109 Kassel, Germany. RP Qiao, ZJ (reprint author), Univ Calif Los Alamos Natl Lab, Div Theoret, T-7, Los Alamos, NM USA. NR 16 TC 11 Z9 11 U1 0 U2 0 PU CONSULTANTS BUREAU PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 0040-5779 J9 THEOR MATH PHYS+ JI Theor. Math. Phys. PD JUN PY 2001 VL 127 IS 3 BP 827 EP 834 DI 10.1023/A:1010412120845 PG 8 WC Physics, Multidisciplinary; Physics, Mathematical SC Physics GA 466GK UT WOS:000170636700014 ER EF