FN Thomson Reuters Web of Science™ VR 1.0 PT J AU Seweryniak, D Woods, PJ Carpenter, MP Davinson, T Janssens, RVF Jenkins, DG Lauritsen, T Lister, CJ Ruiz, C Shergur, J Sinha, S Woehr, A AF Seweryniak, D Woods, PJ Carpenter, MP Davinson, T Janssens, RVF Jenkins, DG Lauritsen, T Lister, CJ Ruiz, C Shergur, J Sinha, S Woehr, A TI Level structure of Mg-22: Implications for the Na-21(p,gamma)Mg-22 astrophysical reaction rate and for the Mg-22 mass SO PHYSICAL REVIEW LETTERS LA English DT Article ID ENERGY-LEVELS; NOVAE; THRESHOLD; STATES AB The level structure of Mg-22 has been studied with high-sensitivity gamma-ray spectroscopy techniques. A complete level scheme is derived incorporating all subthreshold states and all levels in the energy region relevant for novae burning. The excitation energy of the most important astrophysical resonance is measured with improved accuracy and found to differ from previous values. Combining the present result with a recent resonance energy measurement of this state leads to a derived Mg-22 mass excess of -400.5(13) keV. C1 Argonne Natl Lab, Argonne, IL 60439 USA. Univ Edinburgh, Edinburgh EH9 3JZ, Midlothian, Scotland. Univ York, York YO10 5DD, N Yorkshire, England. Simon Fraser Univ, Burnaby, BC V5A 1S6, Canada. Univ Maryland, College Pk, MD 20742 USA. Univ Notre Dame, Notre Dame, IN 46556 USA. RP Seweryniak, D (reprint author), Argonne Natl Lab, 9700 S Cass Ave, Argonne, IL 60439 USA. RI Carpenter, Michael/E-4287-2015 OI Carpenter, Michael/0000-0002-3237-5734 NR 25 TC 35 Z9 35 U1 0 U2 2 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD JAN 28 PY 2005 VL 94 IS 3 AR 032501 DI 10.1103/PhysRevLett.94.032501 PG 4 WC Physics, Multidisciplinary SC Physics GA 891TU UT WOS:000226604700016 PM 15698256 ER PT J AU Sovinec, CR Cohen, BI Cone, GA Hooper, EB McLean, HS AF Sovinec, CR Cohen, BI Cone, GA Hooper, EB McLean, HS TI Numerical investigation of transients in the SSPX spheromak SO PHYSICAL REVIEW LETTERS LA English DT Article ID MAGNETIC HELICITY; ENERGY CONFINEMENT; PLASMA-GUN; SUSTAINMENT; MODEL AB Nonlinear plasma simulations of the Sustained Spheromak Physics Experiment demonstrate the role of transient effects in establishing a toroidal magnetic structure that confines internal energy. Magnetohydrodynamics modeling with temperature-dependent transport coefficients compares well with experimental measurements and shows that the second current pulse improves confinement by keeping the q profile from falling below the value of 1/2, suppressing resonant m=1, n=2 fluctuations. C1 Univ Wisconsin, Madison, WI 53706 USA. Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Sovinec, CR (reprint author), Univ Wisconsin, Madison, WI 53706 USA. NR 23 TC 22 Z9 22 U1 0 U2 9 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD JAN 28 PY 2005 VL 94 IS 3 AR 035003 DI 10.1103/PhysRevLett.94.035003 PG 4 WC Physics, Multidisciplinary SC Physics GA 891TU UT WOS:000226604700036 PM 15698276 ER PT J AU Won, C Wu, YZ Kurahashi, N Zhao, HW Qiu, ZQ Scholl, A Doran, A AF Won, C Wu, YZ Kurahashi, N Zhao, HW Qiu, ZQ Scholl, A Doran, A TI Comment on "Magnetic phase transition in Co/Cu/Ni/Cu(100) and Co/Fe/Ni/Cu(100)" - Reply SO PHYSICAL REVIEW LETTERS LA English DT Editorial Material ID QUANTUM FERROMAGNETS C1 Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Adv Light Source, Berkeley, CA 94720 USA. RP Won, C (reprint author), Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. RI Wu, yizheng/P-2395-2014; Scholl, Andreas/K-4876-2012; Qiu, Zi Qiang/O-4421-2016 OI Wu, yizheng/0000-0002-9289-1271; Qiu, Zi Qiang/0000-0003-0680-0714 NR 7 TC 0 Z9 0 U1 2 U2 4 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD JAN 28 PY 2005 VL 94 IS 3 AR 039704 DI 10.1103/PhysRevLett.94.039704 PG 1 WC Physics, Multidisciplinary SC Physics GA 891TU UT WOS:000226604700097 ER PT J AU Wu, J Lynn, JW Glinka, CJ Burley, J Zheng, H Mitchell, JF Leighton, C AF Wu, J Lynn, JW Glinka, CJ Burley, J Zheng, H Mitchell, JF Leighton, C TI Intergranular giant magnetoresistance in a spontaneously phase separated perovskite oxide SO PHYSICAL REVIEW LETTERS LA English DT Article ID CO-SIO2 GRANULAR FILMS; MAGNETIC SUPERLATTICES; TRANSPORT-PROPERTIES; MANGANITES; TRANSITION; METAL; CONDUCTIVITY; LA1-XCAXMNO3; MULTILAYERS AB We present small-angle neutron scattering data proving that, on the insulating side of the metal-insulator transition, the doped perovskite cobaltite La1-xSrxCoO3 phase separates into ferromagnetic metallic clusters embedded in a nonferromagnetic matrix. This induces a hysteretic magnetoresistance, with temperature and field dependence characteristic of intergranular giant magnetoresistance (GMR). We argue that this system is a natural analog to the artificial structures fabricated by depositing nanoscale ferromagnetic particles in a metallic or insulating matrix; i.e., this material displays a GMR effect without the deliberate introduction of chemical interfaces. C1 Univ Minnesota, Dept Chem Engn & Mat Sci, Minneapolis, MN 55455 USA. Natl Inst Stand & Technol, Ctr Neutron Res, Gaithersburg, MD 20899 USA. Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. RP Leighton, C (reprint author), Univ Minnesota, Dept Chem Engn & Mat Sci, 421 Washington Ave SE, Minneapolis, MN 55455 USA. EM leighton@umn.edu NR 36 TC 123 Z9 125 U1 2 U2 33 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 EI 1079-7114 J9 PHYS REV LETT JI Phys. Rev. Lett. PD JAN 28 PY 2005 VL 94 IS 3 AR 037201 DI 10.1103/PhysRevLett.94.037201 PG 4 WC Physics, Multidisciplinary SC Physics GA 891TU UT WOS:000226604700074 PM 15698314 ER PT J AU Yunoki, S Dagotto, E Sorella, S AF Yunoki, S Dagotto, E Sorella, S TI Role of strong correlation in the recent angle-resolved photoemission spectroscopy experiments on cuprate superconductors SO PHYSICAL REVIEW LETTERS LA English DT Article ID T-J MODEL; HIGH-TEMPERATURE SUPERCONDUCTORS AB Motivated by recent photoemission experiments on cuprates, the low-lying excitations of a strongly correlated superconducting state are studied numerically. It is observed that along the nodal direction these low-lying one-particle excitations show a linear momentum dependence for a wide range of excitation energies and, thus, they do not present a kinklike structure. The nodal Fermi velocity v(F), as well as other observables, are systematically evaluated directly from the calculated dispersions, and they are found to compare well with experiments. It is argued that the parameter dependence of v(F) is quantitatively explained by a simple picture of a renormalized Fermi velocity. C1 Ist Nazl Fis Mat, I-34014 Trieste, Italy. Scuola Int Super Studi Avanzati, I-34014 Trieste, Italy. Univ Tennessee, Dept Phys & Astron, Knoxville, TN 37996 USA. Oak Ridge Natl Lab, Condensed Matter Sci Div, Oak Ridge, TN 37831 USA. RP Yunoki, S (reprint author), Ist Nazl Fis Mat, Via Beirut 4, I-34014 Trieste, Italy. RI Yunoki, Seiji/B-1831-2008 NR 25 TC 24 Z9 24 U1 1 U2 3 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD JAN 28 PY 2005 VL 94 IS 3 AR 037001 DI 10.1103/PhysRevLett.94.037001 PG 4 WC Physics, Multidisciplinary SC Physics GA 891TU UT WOS:000226604700067 PM 15698307 ER PT J AU Sharma, P AF Sharma, P TI Physics - How to create a spin current SO SCIENCE LA English DT Editorial Material ID SPINTRONICS C1 Argonne Natl Lab, Argonne, IL 60439 USA. RP Argonne Natl Lab, 9700 S Cass Ave, Argonne, IL 60439 USA. EM psharma@anl.gov NR 13 TC 41 Z9 43 U1 3 U2 13 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 USA SN 0036-8075 EI 1095-9203 J9 SCIENCE JI Science PD JAN 28 PY 2005 VL 307 IS 5709 BP 531 EP 533 DI 10.1126/science.1099388 PG 3 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 893BJ UT WOS:000226694000034 PM 15681374 ER PT J AU Ghosal, S Hemminger, JC Bluhm, H Mun, BS Hebenstreit, ELD Ketteler, G Ogletree, DF Requejo, FG Salmeron, M AF Ghosal, S Hemminger, JC Bluhm, H Mun, BS Hebenstreit, ELD Ketteler, G Ogletree, DF Requejo, FG Salmeron, M TI Electron spectroscopy of aqueous solution interfaces reveals surface enhancement of halides SO SCIENCE LA English DT Article ID SALT-SOLUTIONS; AIR/WATER INTERFACE; MOLECULAR-STRUCTURE; POLAR SUNRISE; CHEMISTRY; OZONE; BROMINE; PHOTOEMISSION; IONS; NACL AB It has been suggested that enhanced anion concentrations at the liquid/vapor interface of airborne saline droplets are important to aerosol reactions in the atmosphere. We report ionic concentrations in the surface of such solutions. Using x-ray photoelectron spectroscopy operating at near ambient pressure, we have measured the composition of the liquid/vapor interface for deliquesced samples of potassium bromide and potassium iodide. In both cases, the surface composition of the saturated solution is enhanced in the halide anion compared with the bulk of the solution. The enhancement of anion concentration is more dramatic for the larger, more polarizable iodide anion. By varying photoelectron kinetic energies, we have obtained depth profiles of the liquid/vapor interface. Our results are in good qualitative agreement with classical molecular dynamics simulations. Quantitative comparison between the experiments and the simulations indicates that the experimental results exhibit more interface enhancement than predicted theoretically. C1 Univ Calif Irvine, Dept Chem, Irvine, CA 92697 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Chem Sci, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Adv Light Source, Berkeley, CA 94720 USA. Natl Univ La Plata, Fac Ciencias Exactas, Dept Fis, RA-1900 La Plata, Argentina. RP Hemminger, JC (reprint author), Univ Calif Irvine, Dept Chem, Irvine, CA 92697 USA. EM jchemmin@uci.edu RI Mun, Bongjin /G-1701-2013; Ogletree, D Frank/D-9833-2016; Requejo, Felix/O-2260-2016 OI Ogletree, D Frank/0000-0002-8159-0182; Requejo, Felix/0000-0003-4439-864X NR 21 TC 387 Z9 388 U1 14 U2 128 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 JAN 28 PY 2005 VL 307 IS 5709 BP 563 EP 566 DI 10.1126/science.1106525 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 893BJ UT WOS:000226694000042 PM 15681380 ER PT J AU Kamakoti, P Morreale, BD Ciocco, MV Howard, BH Killmeyer, RP Cugini, AV Sholl, DS AF Kamakoti, P Morreale, BD Ciocco, MV Howard, BH Killmeyer, RP Cugini, AV Sholl, DS TI Prediction of hydrogen flux through sulfur-tolerant binary alloy membranes SO SCIENCE LA English DT Article ID PALLADIUM-COPPER ALLOYS; ELEVATED-TEMPERATURES; COMPOSITE MEMBRANES; DILUTE-SOLUTIONS; DIFFUSION; THERMODYNAMICS; PD; SEPARATION; PRESSURES; PERMEANCE AB Metal membranes play a vital rote in hydrogen purification. Defect-free membranes can exhibit effectively infinite selectivity but must also provide high fluxes, resistance to poisoning, long operational lifetimes, and low cost. Alloying offers one route to improve on membranes based on pure metals such as palladium. We show how ab initio calculations and coarse-grained modeling can accurately predict hydrogen fluxes through binary alloy membranes as functions of alloy composition, temperature, and pressure. Our approach, which requires no experimental input apart from knowledge of bulk crystal structures, is demonstrated for palladium-copper alloys, which show nontrivial behavior due to the existence of face-centered cubic and body-centered cubic crystal structures and have the potential to resist sulfur poisoning. The accuracy of our approach is examined by a comparison with extensive experiments using thick foils at elevated temperatures. Our experiments also demonstrate the ability of these membranes to resist poisoning by hydrogen sulfide. C1 Carnegie Mellon Univ, Dept Chem Engn, Pittsburgh, PA 15213 USA. US DOE, Natl Energy Technol Lab, Pittsburgh, PA 15236 USA. RP Sholl, DS (reprint author), Carnegie Mellon Univ, Dept Chem Engn, Pittsburgh, PA 15213 USA. EM shotl@andrew.cmu.edu NR 33 TC 166 Z9 166 U1 5 U2 56 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 JAN 28 PY 2005 VL 307 IS 5709 BP 569 EP 573 DI 10.1126/science.1107041 PG 5 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 893BJ UT WOS:000226694000044 PM 15681382 ER PT J AU Dozzo, P Koo, MS Berger, S Forte, TM Kahl, SB AF Dozzo, P Koo, MS Berger, S Forte, TM Kahl, SB TI Synthesis, characterization, and plasma lipoprotein association of a nucleus-targeted boronated porphyrin SO JOURNAL OF MEDICINAL CHEMISTRY LA English DT Article ID INTRACELLULAR DELIVERY; CHLORIN E(6); PHOTOSENSITIZERS; LOCALIZATION; GLIOMA AB The efficacy of binary cancer therapies such as BNCT and PDT depends critically on the subcellular localization site of the sensitizer. This work presents the synthesis and plasma lipoprotein binding properties of the first reported binary conjugate of a boronated porphyrin with a peptide nuclear localization sequence. The porphyrin-NLS conjugate associates in vitro predominantly with low density lipoproteins. Such association provides a potentially selective entry pathway into malignant cells that overexpress the LDL receptor. C1 Univ Calif San Francisco, Dept Pharmaceut Chem, San Francisco, CA 94143 USA. Lawrence Berkeley Lab, Div Life Sci, Berkeley, CA 94720 USA. RP Kahl, SB (reprint author), Univ Calif San Francisco, Dept Pharmaceut Chem, San Francisco, CA 94143 USA. EM sbkahl@itsa.ucsf.edu FU NCI NIH HHS [CA82478]; NCRR NIH HHS [RR01614] NR 13 TC 40 Z9 41 U1 0 U2 4 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0022-2623 J9 J MED CHEM JI J. Med. Chem. PD JAN 27 PY 2005 VL 48 IS 2 BP 357 EP 359 DI 10.1021/jm049277q PG 3 WC Chemistry, Medicinal SC Pharmacology & Pharmacy GA 891OZ UT WOS:000226591700005 PM 15658849 ER PT J AU Reboredo, FA Galli, G AF Reboredo, FA Galli, G TI Theory of alkyl-terminated silicon quantum dots SO JOURNAL OF PHYSICAL CHEMISTRY B LA English DT Article ID POROUS SILICON; OPTICAL-PROPERTIES; NANOCRYSTALLINE SILICON; ELECTRONIC-PROPERTIES; SI NANOCRYSTALS; SURFACE; NANOPARTICLES; LUMINESCENCE; GAPS; FUNCTIONALIZATION AB We have carried out a series of ab initio calculations to investigate changes in the optical properties of Si quantum dots as a function of surface passivation. In particular, we have compared hydrogen-passivated dots with those having alkyl groups at the surface. We find that, while on clusters with reconstructed surfaces complete alkyl passivation is possible, steric repulsion prevents full passivation of Si dots with unreconstructed surfaces. In addition, our calculations show that steric repulsion may have a dominant effect in determining the surface structure and eventually the stability of alkyl-passivated clusters, with results dependent on the length of the carbon chain. Alkyl passivation weakly affects optical gaps of silicon quantum dots, while it substantially decreases ionization potentials and electron affinities and affects their excited state properties. On the basis of our results, we propose that alkyl-terminated quantum dots may be size selected, taking advantage of the change in ionization potential as a function of the cluster size. C1 Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. RP Reboredo, FA (reprint author), Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. RI Reboredo, Fernando/B-8391-2009 NR 47 TC 96 Z9 96 U1 2 U2 22 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 JAN 27 PY 2005 VL 109 IS 3 BP 1072 EP 1078 DI 10.1021/jp0462254 PG 7 WC Chemistry, Physical SC Chemistry GA 889NN UT WOS:000226449800003 PM 16851062 ER PT J AU Anderson, AB Roques, J Mukerjee, S Murthi, VS Markovic, NM Stamenkovic, V AF Anderson, AB Roques, J Mukerjee, S Murthi, VS Markovic, NM Stamenkovic, V TI Activation energies for oxygen reduction on platinum alloys: Theory and experiment SO JOURNAL OF PHYSICAL CHEMISTRY B LA English DT Article ID TRIFLUOROMETHANE SULFONIC-ACID; HYDROGEN REFERENCE ELECTRODE; SINGLE-CRYSTAL SURFACES; X-RAY-ABSORPTION; POTENTIAL DEPENDENCE; DISK ELECTRODE; O-2 REDUCTION; FUEL-CELLS; THIN-FILM; ADSORPTION AB A combined theoretical and experimental analysis of the electrode potential dependencies of activation energies is presented for the first step in oxygen reduction over platinum and platinum alloy catalysts in both polycrystalline and carbon supported form. Tafel data for several of the catalysts are used to predict potential-dependent activation energies for oxygen reduction over the 0.6-0.9 V range in strong and weak acid. Comparisons with the theoretical curve show good agreement above 0.8 V, suggesting a fairly constant preexponential factor. Arrhenius determinations of activation energies over the 0.7-0.9 V range yield little trend for weak acid, possibly because of the larger uncertainties in the Arrhenius fits, but the strong acid results have smaller uncertainties and for them the measured activation energies trend up with potential. C1 Case Western Reserve Univ, Dept Chem, Cleveland, OH 44106 USA. Northeastern Univ, Dept Chem, Boston, MA 02115 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. RP Anderson, AB (reprint author), Case Western Reserve Univ, Dept Chem, 10900 Eucid Ave, Cleveland, OH 44106 USA. EM aba@po.cwru.edu; smukerjee@lynx.neu.edu; nmmarkovic@lbl.gov NR 40 TC 113 Z9 115 U1 6 U2 51 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 JAN 27 PY 2005 VL 109 IS 3 BP 1198 EP 1203 DI 10.1021/jp047468z PG 6 WC Chemistry, Physical SC Chemistry GA 889NN UT WOS:000226449800022 PM 16851081 ER PT J AU Pingali, SV Takiue, T Luo, GM Tikhonov, AM Ikeda, N Aratono, M Schlossman, ML AF Pingali, SV Takiue, T Luo, GM Tikhonov, AM Ikeda, N Aratono, M Schlossman, ML TI X-ray reflectivity and interfacial tension study of the structure and phase behavior of the interface between water and mixed surfactant solutions of CH(3)(CH(2))(19)OH and CF(3)(CF(2))(7)(CH(2))(2)OH in hexane SO JOURNAL OF PHYSICAL CHEMISTRY B LA English DT Article ID ADSORBED FILM; FLUOROALKANOL MIXTURE; NEUTRON-SCATTERING; HYDROCARBON SURFACTANTS; ALKANE INTERFACE; MONOLAYERS; TRANSITION; FLUOROCARBON; MISCIBILITY; MICELLES AB The interface between water and mixed surfactant solutions of CH(3)(CH(2))(19)OH and CF(3)(CF(2))(7)(CH(2))(2)OH in hexane was studied with interfacial tension and X-ray reflectivity measurements. Measurements of the tension as a function of temperature for a range of total bulk surfactant concentrations and for three different values of the molal ratio of fluorinated to total surfactant concentration (0.25, 0.28, and 0.5) determined that the interface can be in three different monolayer phases. The interfacial excess entropy determined for these phases suggests that two of the phases are condensed single surfactant monolayers of CH(3)(CH(2))(19)OH and CF(3)(CF(2))(7)(CH(2))(2)OH. By studying four different compositions as a function of temperature, X-ray reflectivity was used to determine the structure of these monolayers in all three phases at the liquid-liquid interface. The X-ray reflectivity measurements were analyzed with a layer model to determine the electron density and thickness of the headgroup and tailgroup layers. The reflectivity demonstrates that phases 1 and 2 correspond to an interface fully covered by only one of the surfactants (liquid monolayer of CH(3)(CH(2))(19)OH in phase 1 and a solid condensed monolayer of CF(3)(CF(2))(7)(CH(2))(2)OH in phase 2). This was determined by analysis of the electron density profile as well as by direct comparison to reflectivity studies of the liquid-liquid interface in systems containing only one of the surfactants (plus hexane and water). The liquid monolayer of CH3(CH2)19OH undergoes a transition to the solid monolayer of CF(3)(CF(2))(7)(CH(2))(2)OH with increasing temperature. Phase 3 and the transition regions between phases 1 and 2 consist of a mixed monolayer at the interface that contains domains of the two surfactants. In phase 3 the interface also contains gaseous regions that occupy progressively more of the interface as the temperature is increased. The reflectivity determined the coverage of the surfactant domains at the interface. A simple model is presented that predicts the basic features of the domain coverage as a function of temperature for the mixed surfactant system from the behavior of the single surfactant systems. C1 Univ Illinois, Dept Phys, Chicago, IL 60607 USA. Univ Illinois, Dept Chem, Chicago, IL 60607 USA. Brookhaven Natl Lab, Natl Synchrotron Light Source, Upton, NY 11973 USA. Kyushu Univ, Fac Sci, Dept Chem, Fukuoka 8128581, Japan. Fukuoka Womens Univ, Fac Human Environm Sc, Dept Environm Sci, Fukuoka 8138529, Japan. RP Takiue, T (reprint author), Univ Illinois, Dept Phys, 845 W Taylor St, Chicago, IL 60607 USA. EM t.takscc@mbox.nc.kyushu-u.ac.jp; m.arascc@mbox.nc.kyushu-u.ac.jp; schloss@uic.edu RI Tikhonov, Aleksey/N-1111-2016; OI Pingali, Sai Venkatesh/0000-0001-7961-4176 NR 54 TC 31 Z9 31 U1 1 U2 7 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 JAN 27 PY 2005 VL 109 IS 3 BP 1210 EP 1225 DI 10.1021/jp045887q PG 16 WC Chemistry, Physical SC Chemistry GA 889NN UT WOS:000226449800024 PM 16851083 ER PT J AU Bowie, JU AF Bowie, JU TI Cell biology - Border crossing SO NATURE LA English DT Editorial Material ID MEMBRANE-PROTEIN; INTEGRATION; CHANNEL C1 Univ Calif Los Angeles, Inst Mol Biol, Dept Chem & Biochem, Los Angeles, CA 90095 USA. Univ Calif Los Angeles, UCLA DOE Lab Genom & Proteom, Los Angeles, CA 90095 USA. RP Bowie, JU (reprint author), Univ Calif Los Angeles, Inst Mol Biol, Dept Chem & Biochem, Los Angeles, CA 90095 USA. EM bowie@mbi.ucla.edu NR 11 TC 9 Z9 9 U1 0 U2 3 PU NATURE PUBLISHING GROUP PI LONDON PA MACMILLAN BUILDING, 4 CRINAN ST, LONDON N1 9XW, ENGLAND SN 0028-0836 J9 NATURE JI Nature PD JAN 27 PY 2005 VL 433 IS 7024 BP 367 EP 369 DI 10.1038/433367a PG 3 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 890XZ UT WOS:000226546200025 PM 15674274 ER PT J AU Lee, HN Christen, HM Chisholm, MF Rouleau, CM Lowndes, DH AF Lee, HN Christen, HM Chisholm, MF Rouleau, CM Lowndes, DH TI Strong polarization enhancement in asymmetric three-component ferroelectric superlattices SO NATURE LA English DT Article ID ARTIFICIAL BATIO3/SRTIO3 SUPERLATTICES; PULSED-LASER DEPOSITION; DIELECTRIC-PROPERTIES; FILMS; INTERFACE; SURFACE; SRTIO3 AB Theoretical predictions - motivated by recent advances in epitaxial engineering - indicate a wealth of complex behaviour arising in superlattices of perovskite-type metal oxides. These include the enhancement of polarization by strain(1,2) and the possibility of asymmetric properties in three-component superlattices(3). Here we fabricate superlattices consisting of barium titanate (BaTiO3), strontium titanate (SrTiO3) and calcium titanate (CaTiO3) with atomic-scale control by high-pressure pulsed laser deposition on conducting, atomically flat strontium ruthenate (SrRuO3) layers. The strain in BaTiO3 layers is fully maintained as long as the BaTiO3 thickness does not exceed the combined thicknesses of the CaTiO3 and SrTiO3 layers. By preserving full strain and combining heterointerfacial couplings, we find an overall 50% enhancement of the superlattice global polarization with respect to similarly grown pure BaTiO3, despite the fact that half the layers in the superlattice are nominally nonferroelectric. We further show that even superlattices containing only single-unit-cell layers of BaTiO3 in a paraelectric matrix remain ferroelectric. Our data reveal that the specific interface structure and local asymmetries play an unexpected role in the polarization enhancement. C1 Oak Ridge Natl Lab, Condensed Matter Sci Div, Oak Ridge, TN 37831 USA. RP Lee, HN (reprint author), Oak Ridge Natl Lab, Condensed Matter Sci Div, Oak Ridge, TN 37831 USA. EM hnlee@ornl.gov RI Kim, Yu Jin/A-2433-2012; Christen, Hans/H-6551-2013; Lee, Ho Nyung/K-2820-2012; Rouleau, Christopher/Q-2737-2015 OI Christen, Hans/0000-0001-8187-7469; Lee, Ho Nyung/0000-0002-2180-3975; Rouleau, Christopher/0000-0002-5488-3537 NR 23 TC 445 Z9 449 U1 26 U2 271 PU NATURE PUBLISHING GROUP PI LONDON PA MACMILLAN BUILDING, 4 CRINAN ST, LONDON N1 9XW, ENGLAND SN 0028-0836 J9 NATURE JI Nature PD JAN 27 PY 2005 VL 433 IS 7024 BP 395 EP 399 DI 10.1038/nature03261 PG 5 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 890XZ UT WOS:000226546200037 PM 15674286 ER PT J AU Heger, A Kolbe, E Haxton, WC Langanke, K Martinez-Pinedo, G Woosley, SE AF Heger, A Kolbe, E Haxton, WC Langanke, K Martinez-Pinedo, G Woosley, SE TI Neutrino nucleosynthesis SO PHYSICS LETTERS B LA English DT Article ID MASSIVE STARS; SHELL-MODEL; ABUNDANCES; EVOLUTION; FLUORINE; NUCLEAR; SOLAR AB Nucleosynthesis in massive stars by the neutrino process is studied using newly calculated cross sections, an expanded reaction network, and realistic models for 15 and 25 solar mass supernovae. The production of light isotopes from abundant progenitors is considered, along with that of several rare, heavy, proton-rich isotopes. In particular, new results are presented for B-11, F-19, La-138, and Ta-180. The production of these isotopes could potentially place limits on neutrino spectra and neutrino oscillations. (C) 2004 Elsevier B.V. All rights reserved. C1 Univ Chicago, Dept Astron & Astrophys, Chicago, IL 60637 USA. Los Alamos Natl Lab, Theoret Astrophys Grp, Los Alamos, NM 87545 USA. Univ Basel, Dept Phys, CH-4056 Basel, Switzerland. Univ Washington, Inst Nucl Theory, Seattle, WA 98195 USA. Aarhus Univ, Inst Fys & Astronomi, DK-8000 Aarhus, Denmark. ICREA, E-08034 Barcelona, Spain. Inst Estudis Espacials Catalunya, E-08034 Barcelona, Spain. Univ Calif Santa Cruz, Dept Astron & Astrophys, Santa Cruz, CA 95064 USA. RP Heger, A (reprint author), Univ Chicago, Dept Astron & Astrophys, 5640 S Ellis Ave, Chicago, IL 60637 USA. EM 1@2sn.org RI Martinez-Pinedo, Gabriel/A-1915-2013 OI Martinez-Pinedo, Gabriel/0000-0002-3825-0131 NR 22 TC 138 Z9 138 U1 0 U2 5 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0370-2693 J9 PHYS LETT B JI Phys. Lett. B PD JAN 27 PY 2005 VL 606 IS 3-4 BP 258 EP 264 DI 10.1016/j.physletb.2004.12.017 PG 7 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 893CJ UT WOS:000226696600005 ER PT J AU Vitev, I AF Vitev, I TI Jet quenching at intermediate RHIC energies SO PHYSICS LETTERS B LA English DT Article ID NUCLEUS-NUCLEUS COLLISIONS; P(T) AZIMUTHAL ASYMMETRY; PLUS AU; PARTON DISTRIBUTIONS; HADRON-PRODUCTION; PERTURBATIVE QCD; MATTER; SPS; TOMOGRAPHY; SCATTERING AB The final state energy loss of fast partons penetrating a longitudinally expanding quark-gluon plasma of effective gluon rapidity density dN(g)/dy = 650-800 is evaluated and incorporated together with the multiple initial state Cronin scattering in the lowest order perturbative QCD hadron production formalism. Predictions for the neutral pion attenuation in central An + An collisions at the intermediate RHIC energy of roots(NN) = 62 GeV relative to the binary collision scaled p + p result are given. The quenching is found to be a factor of 2-3 with a moderate transverse momentum dependence and the attenuation of the away side di-hadron correlation function is estimated to be 3-5-fold. (C) 2004 Elsevier B.V. All rights reserved. C1 Iowa State Univ, Dept Phys & Astron, Ames, IA 50011 USA. Los Alamos Natl Lab, Div Theory, Los Alamos, NM 87545 USA. Los Alamos Natl Lab, Div Phys, Los Alamos, NM 87545 USA. RP Iowa State Univ, Dept Phys & Astron, Ames, IA 50011 USA. EM ivitev@iastate.edu NR 82 TC 22 Z9 22 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0370-2693 EI 1873-2445 J9 PHYS LETT B JI Phys. Lett. B PD JAN 27 PY 2005 VL 606 IS 3-4 BP 303 EP 312 DI 10.1016/j.physletb.2004.12.013 PG 10 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 893CJ UT WOS:000226696600011 ER PT J AU Vergados, JD Ejiri, H AF Vergados, JD Ejiri, H TI The role of ionization electrons in direct neutralino detection SO PHYSICS LETTERS B LA English DT Article DE LSP; direct neutralino search; ionization electrons; electron detection; dark matter; WIMP ID DARK-MATTER DETECTION; DIRECT SEARCH; WIMP SEARCH; MODULATION; MAXIMA-1; LIMITS; RATES; SPIN AB In this Letter we estimate the event rates of neutralino-nucleus scattering leading to electron emission by the atomic ionization. We find that the branching ratio for detecting electrons vis-a-vis the traditional neutralino-nucleus elastic scattering sensitively depends on the threshold energy. In the case of a light target and a neutralino mass of 100 GeV we estimate it to be around 10 percent assuming a reasonable threshold energy of 250 eV. (C) 2004 Published by Elsevier B.V. C1 Univ Cyprus, Dept Phys, CY-1678 Nicosia, Cyprus. Los Alamos Natl Lab, Div Theoret Phys, Los Alamos, NM 87545 USA. Int Christian Univ, Mitaka, Tokyo 1818585, Japan. Osaka Univ, Emeritus RCNP, Osaka 5670047, Japan. RP Vergados, JD (reprint author), Univ Cyprus, Dept Phys, CY-1678 Nicosia, Cyprus. EM vergados@arteiiiisl.physics.uoi.gr NR 59 TC 15 Z9 15 U1 1 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0370-2693 EI 1873-2445 J9 PHYS LETT B JI Phys. Lett. B PD JAN 27 PY 2005 VL 606 IS 3-4 BP 313 EP 322 DI 10.1016/j.physletb.2004.11.085 PG 10 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 893CJ UT WOS:000226696600012 ER PT J AU Lu, ZM Zhang, DX AF Lu, ZM Zhang, DX TI Analytical solutions to statistical moments for transient flow in two-dimensional, bounded, randomly heterogeneous media SO WATER RESOURCES RESEARCH LA English DT Article ID STEADY-STATE FLOW; HEAD SPATIAL VARIABILITY; STOCHASTIC-ANALYSIS; GROUNDWATER-FLOW; CONDITIONAL PROBABILITIES; LOCALIZED ANALYSES; DOMAINS 1; AQUIFERS; MODELS; SIMULATIONS AB [1] In this paper we derive analytical solutions to statistical moments for transient saturated flow in two-dimensional, bounded, randomly heterogeneous porous media. By perturbation expansions, we first derive partial differential equations governing the zeroth-order head h((0)) and the first-order head term h((1)), where orders are in terms of the standard deviation of the log transmissivity. We then solve h((0)) and h((1)) analytically, both of which are expressed as infinite series. The head perturbation h((1)) is then used to derive expressions for autocovariance of the hydraulic head and the cross covariance between the log transmissivity and head. The expressions for the mean flux and flux covariance tensor are formulated from the head moments based on Darcy's law. Using numerical examples, we demonstrate the convergence of these solutions. We also examine the accuracy of these first-order solutions by comparing them with solutions from both Monte Carlo simulations and the numerical moment equation method. C1 Los Alamos Natl Lab, Hydrol Geochem & Geol Grp, Los Alamos, NM 87545 USA. Univ Oklahoma, Mewbourne Sch Petr & Geol Engn, Norman, OK 73019 USA. RP Lu, ZM (reprint author), Los Alamos Natl Lab, Hydrol Geochem & Geol Grp, EES-6,MS T003, Los Alamos, NM 87545 USA. EM zhiming@lanl.gov; donzhang@ou.edu RI Zhang, Dongxiao/D-5289-2009 OI Zhang, Dongxiao/0000-0001-6930-5994 NR 29 TC 4 Z9 4 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0043-1397 J9 WATER RESOUR RES JI Water Resour. Res. PD JAN 27 PY 2005 VL 41 IS 1 AR W01016 DI 10.1029/2004WR003389 PG 13 WC Environmental Sciences; Limnology; Water Resources SC Environmental Sciences & Ecology; Marine & Freshwater Biology; Water Resources GA 892ZI UT WOS:000226688100003 ER PT J AU Daly, DS White, AM Varnum, SM Anderson, KK Zangar, RC AF Daly, DS White, AM Varnum, SM Anderson, KK Zangar, RC TI Evaluating concentration estimation errors in ELISA microarray experiments SO BMC BIOINFORMATICS LA English DT Article ID CDNA MICROARRAY; STANDARDS; DESIGN; NORMALIZATION; CALIBRATION; REGRESSION AB Background: Enzyme-linked immunosorbent assay (ELISA) is a standard immunoassay to estimate a protein's concentration in a sample. Deploying ELISA in a microarray format permits simultaneous estimation of the concentrations of numerous proteins in a small sample. These estimates, however, are uncertain due to processing error and biological variability. Evaluating estimation error is critical to interpreting biological significance and improving the ELISA microarray process. Estimation error evaluation must be automated to realize a reliable high-throughput ELISA microarray system. In this paper, we present a statistical method based on propagation of error to evaluate concentration estimation errors in the ELISA microarray process. Although propagation of error is central to this method and the focus of this paper, it is most effective only when comparable data are available. Therefore, we briefly discuss the roles of experimental design, data screening, normalization, and statistical diagnostics when evaluating ELISA microarray concentration estimation errors. Results: We use an ELISA microarray investigation of breast cancer biomarkers to illustrate the evaluation of concentration estimation errors. The illustration begins with a description of the design and resulting data, followed by a brief discussion of data screening and normalization. In our illustration, we fit a standard curve to the screened and normalized data, review the modeling diagnostics, and apply propagation of error. We summarize the results with a simple, three-panel diagnostic visualization featuring a scatterplot of the standard data with logistic standard curve and 95% confidence intervals, an annotated histogram of sample measurements, and a plot of the 95% concentration coefficient of variation, or relative error, as a function of concentration. Conclusions: This statistical method should be of value in the rapid evaluation and quality control of high-throughput ELISA microarray analyses. Applying propagation of error to a variety of ELISA microarray concentration estimation models is straightforward. Displaying the results in the three-panel layout succinctly summarizes both the standard and sample data while providing an informative critique of applicability of the fitted model, the uncertainty in concentration estimates, and the quality of both the experiment and the ELISA microarray process. C1 Pacific NW Natl Lab, Richland, WA 99352 USA. RP Daly, DS (reprint author), Pacific NW Natl Lab, POB 999, Richland, WA 99352 USA. EM DS.Daly@PNL.gov; Amanda.White@pnl.gov; susan.varnum@pnl.gov; Kevin.Anderson@pnl.gov; Richard.Zangar@pnl.gov NR 32 TC 23 Z9 25 U1 2 U2 12 PU BIOMED CENTRAL LTD PI LONDON PA MIDDLESEX HOUSE, 34-42 CLEVELAND ST, LONDON W1T 4LB, ENGLAND SN 1471-2105 J9 BMC BIOINFORMATICS JI BMC Bioinformatics PD JAN 26 PY 2005 VL 6 AR 17 DI 10.1186/1471-2105/6/17 PG 11 WC Biochemical Research Methods; Biotechnology & Applied Microbiology; Mathematical & Computational Biology SC Biochemistry & Molecular Biology; Biotechnology & Applied Microbiology; Mathematical & Computational Biology GA 903UO UT WOS:000227451300001 PM 15673468 ER PT J AU Hirano, S Yamamoto, K Ishiai, M Yamazoe, M Seki, M Matsushita, N Ohzeki, M Yamashita, YM Arakawa, H Buerstedde, JM Enomoto, T Takeda, S Thompson, LH Takata, M AF Hirano, S Yamamoto, K Ishiai, M Yamazoe, M Seki, M Matsushita, N Ohzeki, M Yamashita, YM Arakawa, H Buerstedde, JM Enomoto, T Takeda, S Thompson, LH Takata, M TI Functional relationships of FANCC to homologous recombination, translesion synthesis, and BLM SO EMBO JOURNAL LA English DT Article DE Bloom syndrome; Fanconi anemia; homologous recombination; sister chromatid exchange; translesion synthesis ID DOUBLE-STRAND BREAKS; SISTER-CHROMATID EXCHANGES; ANEMIA GROUP-C; VERTEBRATE CELLS; RECQ HELICASES; DNA-DAMAGE; REPLICATION FORKS; GENOMIC STABILITY; FANCONIS ANEMIA; BLOOM-SYNDROME AB Some of the restarting events of stalled replication forks lead to sister chromatid exchange ( SCE) as a result of homologous recombination (HR) repair with crossing over. The rate of SCE is elevated by the loss of BLM helicase or by a defect in translesion synthesis (TLS). We found that spontaneous SCE levels were elevated similar to2-fold in chicken DT40 cells deficient in Fanconi anemia ( FA) gene FANCC. To investigate the mechanism of the elevated SCE, we deleted FANCC in cells lacking Rad51 paralog XRCC3, TLS factor RAD18, or BLM. The increased SCE in fancc cells required Xrcc3, whereas the fancc/rad18 double mutant exhibited higher SCE than either single mutant. Unexpectedly, SCE in the fancc/blm mutant was similar to that in blm cells, indicating functional linkage between FANCC and BLM. Furthermore, MMC-induced formation of GFP-BLM nuclear foci was severely compromised in both human and chicken fancc or fancd2 cells. Our cell survival data suggest that the FA proteins serve to facilitate HR, but not global TLS, during crosslink repair. C1 Kawasaki Med Univ, Dept Immunol & Mol Genet, Okayama 7010192, Japan. Kyoto Univ, Grad Sch Med, Dept Radiat Genet, Sakyo Ku, Kyoto, Japan. Tohoku Univ, Grad Sch Pharmaceut Sci, Mol Cell Biol Lab, Aoba Ku, Sendai, Miyagi 980, Japan. GSF, Inst Mol Radiobiol, Munich, Germany. Lawrence Livermore Natl Lab, Biol & Biotechnol Res Program, Livermore, CA USA. RP Takata, M (reprint author), Kawasaki Med Univ, Dept Immunol & Mol Genet, 577 Matsushima, Okayama 7010192, Japan. EM mtakata@med.kawasaki-m.ac.jp OI Yamashita, Yukiko/0000-0001-5541-0216 FU NCI NIH HHS [CA89405, R01 CA089405] NR 60 TC 80 Z9 82 U1 2 U2 4 PU NATURE PUBLISHING GROUP PI NEW YORK PA 345 PARK AVE SOUTH, NEW YORK, NY 10010-1707 USA SN 0261-4189 J9 EMBO J JI Embo J. PD JAN 26 PY 2005 VL 24 IS 2 BP 418 EP 427 DI 10.1038/sj.emboj.7600534 PG 10 WC Biochemistry & Molecular Biology; Cell Biology SC Biochemistry & Molecular Biology; Cell Biology GA 897CQ UT WOS:000226982000018 PM 15616572 ER PT J AU Li, B Corbett, JD AF Li, B Corbett, JD TI Phase stabilization through electronic tuning: Electron-poorer alkali-metal-indium compounds with unprecedented In/Li clusters SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Article ID MACROPOLYHEDRAL BORANES; ZINTL-PHASES; NETWORK; REQUIREMENTS; CHEMISTRY; GALLIUM AB Three alkali-metal-indium compounds K34In92.30Li12.70 (I), K14Na20In91.82Li13.18 (II), and K14Na20I96.30 (III) (all R (3) over barm) have been synthesized and characterized by structural and physical property measurements and electronic structure calculations. Novel mixed In/Li anionic icosahedra and fused icosahedra form in I and II. All three contain In-28 as the first triply fused In icosahedra, which are further linked into (In-28)In(In-28) sandwich adducts in compounds I and II and (In-28)In-2(In-28) in III. Stabilization of these electron-poorer phases through electronic tuning occurs via two different structural (redox) perturbations, either by substitution of certain indium atoms in the clusters by electron-poorer lithium atoms or by the introduction of defects and disorder in the fused cluster (111). The preferential occurrence of either substitutions or defect formation in the clusters is consistent with extended Huckel band calculation results for both the ideal pure indium phase and the Li-substituted equivalent. Model (ideal) and experimental E-F values (based on stoichiometries) fall around a pseudogap in DOS. All three compounds are metallic according to both EHTB band calculations and measured resistivities. The cations (A = K, Na) in all the three structures generate A(136) clathrate-II type networks with remarkably specific and transferable cation dispositions around the two types of anionic cluster units. C1 Iowa State Univ, Ames Lab DOE, Ames, IA 50011 USA. Iowa State Univ, Dept Chem, Ames, IA 50011 USA. RP Corbett, JD (reprint author), Iowa State Univ, Ames Lab DOE, Ames, IA 50011 USA. EM jcorbett@iastate.edu NR 48 TC 35 Z9 35 U1 0 U2 4 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 JAN 26 PY 2005 VL 127 IS 3 BP 926 EP 932 DI 10.1021/ja0402046 PG 7 WC Chemistry, Multidisciplinary SC Chemistry GA 889SO UT WOS:000226463000034 PM 15656631 ER PT J AU Chen, BW Mayer, MU Markillie, LM Stenoien, DL Squier, TC AF Chen, BW Mayer, MU Markillie, LM Stenoien, DL Squier, TC TI Dynamic motion of helix A in the amino-terminal domain of calmodulin is stabilized upon calcium activation SO BIOCHEMISTRY LA English DT Article ID MEMBRANE CA-ATPASE; OPPOSING GLOBULAR DOMAINS; N-DOMAIN; VERTEBRATE CALMODULIN/; MOLECULAR RECOGNITION; ROTATIONAL-DYNAMICS; NMR-SPECTROSCOPY; NERVOUS-SYSTEM; BINDING; FLUORESCENCE AB Calcium-dependent changes in the internal dynamics and average structures of the opposing globular domains of calmodulin (CaM), as well as their relative spatial arrangement, contribute to the productive association between CaM and a range of different target proteins, affecting their functional activation. To identify dynamic structural changes involving individual alpha-helical elements and their modulation by calcium activation, we have used site-directed mutagenesis to engineer a tetracysteine binding motif within helix A near the amino terminus of calmodulin (CaM), permitting the selective and rigid attachment of the fluorescent probe 4',5'-bis(1,3,2-dithioarsolan-2-yl)fluorescein (FlAsH) with full retention of function. The rigid tetracoordinate linkage of FlAsH to CaM, in conjunction with frequency domain fluorescence anisotropy measurements, allows assessment of dynamic changes associated with calcium activation without interference from independent probe motion. Taking advantage of the large fluorescence enhancement associated with binding of FlAsH to CaM, we determined rates of binding of FlAsH to apo-CaM and calcium-activated CaM to be 2800 +/- 80 and 310 +/- 10 M-1 s(-1), respectively. There is no difference in the solvent accessibility of the bound FlAsH irrespective of calcium binding to CaM. Thus, given that FlAsH selectively labels disordered structures, the large difference in rates of FlAsH binding indicates that calcium binding stabilizes helix A. Frequency domain anisotropy measurements of bound HASH indicate that prior to calcium activation, helix A undergoes large amplitude nanosecond motions. Following calcium activation, helix A becomes immobile, and structurally coupled to the overall rotation of CaM. We discuss these results in the context of a model that suggests stabilization of helix A relative to other domain elements in the CaM structure is critical to defining high-affinity binding clefts, and in promoting specific and ordered binding of the opposing lobes of CaM to target proteins. C1 Pacific NW Natl Lab, Fundamental Sci Directorate, Div Biol Sci, Cell Biol & Biochem Grp, Richland, WA 99352 USA. RP Squier, TC (reprint author), Pacific NW Natl Lab, Fundamental Sci Directorate, Div Biol Sci, Cell Biol & Biochem Grp, POB 999,Mail Stop P7-53, Richland, WA 99352 USA. EM thomas.squier@pnl.gov FU NIA NIH HHS [AG17996] NR 65 TC 29 Z9 31 U1 0 U2 4 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0006-2960 J9 BIOCHEMISTRY-US JI Biochemistry PD JAN 25 PY 2005 VL 44 IS 3 BP 905 EP 914 DI 10.1021/bi048332u PG 10 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA 889CN UT WOS:000226421200008 PM 15654746 ER PT J AU Schneider, EL Marletta, MA AF Schneider, EL Marletta, MA TI Heme binding to the histidine-rich protein II from Plasmodium falciparum SO BIOCHEMISTRY LA English DT Article ID FERRIPROTOPORPHYRIN-IX; HEMOZOIN FORMATION; BETA-HEMATIN; MALARIA; POLYMERIZATION; CHLOROQUINE; SERUM; GLYCOPROTEIN; CONFORMATION; 3(10)-HELIX AB The histidine-rich protein II (HRP II) from Plasmodium falciparum has been implicated in the formation of hemozoin, a detoxified, crystalline form of ferric protoporphyrin IX (Fe3+-PPIX) produced by the parasite. Fe3+-PPIX titrations coupled with quantitative amino acid analysis showed that HRP II binds 15 Fe3+-PPIX molecules per 30 kDa monomer. Circular dichroism spectroscopy was used to probe the secondary structure of HRP II with and without bound Fe3+-PPIX. These studies have revealed large changes in the secondary structure with Fe3+-PPIX binding, changing from a random coil in the absence of Fe3+-PPIX to a more ordered helical structure in the presence of Fe3+-PPIX. The Fe3+-PPIX-bound HRP II structure most closely resembles a 3(10)-helix. Coincident with this structural change caused by Fe3+-PPIX binding, the formation of an intermolecular disulfide bond occurs between HRP II monomers. In vitro pull-down assays show an interaction between monomers that is dependent on the presence of Fe3+-PPIX. One model that best fits with the data reported here requires formation of 15 intermolecular bishistidyl ligated Fe3+-PPIX molecules arranged in a head to head fashion, which would then allow for the formation of an intermolecular disulfide bond. The structure best able to accommodate these requirements is a 3(10)-helix. C1 Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Dept Chem, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Dept Mol & Cell Biol, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Div Phys Biosci, Berkeley, CA 94720 USA. RP Marletta, MA (reprint author), Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Dept Chem, 211 Lewis Hall, Berkeley, CA 94720 USA. EM marletta@berkeley.edu NR 37 TC 27 Z9 29 U1 0 U2 4 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0006-2960 J9 BIOCHEMISTRY-US JI Biochemistry PD JAN 25 PY 2005 VL 44 IS 3 BP 979 EP 986 DI 10.1021/bi048570p PG 8 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA 889CN UT WOS:000226421200016 PM 15654754 ER PT J AU Schneider, EL King, DS Marletta, MA AF Schneider, EL King, DS Marletta, MA TI Amino acid substitution and modification resulting from Escherichia coli expression of recombinant Plasmodium falciparum histidine-rich protein II SO BIOCHEMISTRY LA English DT Article ID FERRIPROTOPORPHYRIN-IX; CHLOROQUINE; MISTRANSLATION; METHYLATION; MECHANISM; PARASITE AB The histidine-rich protein II (HRP II) from Plasmodium falciparum is an unusual protein composed of 40% alanine, 36% histidine, and 11% aspartate residues. Expression of HRP II in Escherichia coli results in the isolation of a heterogeneous protein. Mass spectrometry reveals a reduction in mass by multiples of 9 Da from the expected molecular mass that can be attributed to the substitution of glutamine for some histidine residues in the sequence. The extent of the glutamine for histidine substitution can be reduced by slowing the expression rate. Mass spectral analysis of HRP II also revealed cc-amino methylation of the N-terminal alanine residue of HRP II. C1 Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Dept Chem, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Dept Mol & Cell Biol, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Div Phys Biosci, Berkeley, CA 94720 USA. Univ Calif Berkeley, Howard Hughes Med Inst, Berkeley, CA 94720 USA. RP Marletta, MA (reprint author), Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Dept Chem, 211 Lewis Hall, Berkeley, CA 94720 USA. EM marletta@berkeley.edu NR 24 TC 11 Z9 11 U1 0 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0006-2960 J9 BIOCHEMISTRY-US JI Biochemistry PD JAN 25 PY 2005 VL 44 IS 3 BP 987 EP 995 DI 10.1021/bi048581h PG 9 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA 889CN UT WOS:000226421200017 PM 15654755 ER PT J AU Baumann, TF Gash, AE Chinn, SC Sawvel, AM Maxwell, RS Satcher, JH AF Baumann, TF Gash, AE Chinn, SC Sawvel, AM Maxwell, RS Satcher, JH TI Synthesis of high-surface-area alumina aerogels without the use of alkoxide precursors SO CHEMISTRY OF MATERIALS LA English DT Article ID SOL-GEL SYNTHESIS; ISOPROPYL-ALCOHOL SYSTEM; MAS NMR; CATALYTIC-PROPERTIES; POROUS ALUMINA; OXIDE; WATER; HYDROLYSIS; TEXTURE; AL2O3 AB Alumina aerogels were prepared through the addition of propylene oxide to aqueous or ethanolic solutions of hydrated aluminum salts, AlCl3.6H(2)O or Al(NO3)(3).9H(2)O, followed by drying with supercritical CO,. This technique affords low-density (60-130 kg/ml), high-surface-area (600-700 m(2)/g) alumina aerogel monoliths without the use of alkoxide precursors. The dried alumina aerogels were characterized using elemental analysis, high-resolution transmission electron microscopy, powder X-ray diffraction, solid-state NMR, acoustic measurements, and nitrogen adsorption/desorption analysis. Powder X-ray diffraction and TEM analysis indicated that the aerogel prepared from hydrated AlCl3 in water or ethanol possessed microstructures containing highly reticulated networks of pseudoboehmite fibers, 2-5 nm in diameter and of varying lengths, whereas the aerogels prepared from hydrated Al(NO3)(3) in ethanol were amorphous with microstructures comprised of interconnected spherical particles with diameters in the 5-15 nm range. The difference in microstructure resulted in each type of aerogel displaying distinct physical and mechanical properties. In particular, the alumina aerogels with the weblike microstructure were far more mechanically robust than those with the colloidal network, based on acoustic measurements. Both types of alumina aerogels can be transformed to gamma-Al2O3 through calcination at 800 degreesC without a significant loss in surface area or monolithicity. C1 Lawrence Livermore Natl Lab, Chem & Mat Sci Directorate, Livermore, CA 94551 USA. Lawrence Livermore Natl Lab, Energy & Environm Directorate, Livermore, CA 94551 USA. RP Satcher, JH (reprint author), Lawrence Livermore Natl Lab, Chem & Mat Sci Directorate, POB 808,L-092, Livermore, CA 94551 USA. EM satcherl@llnl.gov RI Chinn, Sarah/E-1195-2011 NR 56 TC 169 Z9 176 U1 23 U2 147 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 JAN 25 PY 2005 VL 17 IS 2 BP 395 EP 401 DI 10.1021/cm048800m PG 7 WC Chemistry, Physical; Materials Science, Multidisciplinary SC Chemistry; Materials Science GA 889ZC UT WOS:000226480400030 ER PT J AU Tachikawa, H Abe, S AF Tachikawa, H Abe, S TI Structures and excitation energies of ozone-water clusters O-3(H2O)n (n=1-4) SO INORGANICA CHIMICA ACTA LA English DT Article DE ozone-water complex; excitation energy; hydration structure; spectral shift ID AB-INITIO; COMPLEXES; STATES; O-3 AB Hybrid density functional theory (DFT) and time-dependent DFT (TD-DFT) calculations have been carried out for ozone-water clusters O-3(H2O)(n) (n = 1-4) in order to obtain hydration effects on the absorption spectrum of ozone. The first water molecule in n = I is bound to the ozone molecule by an oxygen orientation form in which the oxygen atom of H2O orients the central oxygen atom of O-3. In n = 2, the water dimer is bound to O-3 and then the cyclic structure is formed as the most stable structure. For n = 3 (or n = 4), the cyclic water trimer (or tetramer) is bound by a hydrogen bond to the ozone molecule. The TD-DFT calculations of O-3(H2O)(n) (n = 0-4) show that the first and second excitation energies of O-3 are blue-shifted by the interaction with the water clusters. The magnitude of the spectral shift is largest in n = 2, and the shifts of the excitation energies are +0.07 eV for S-1 and +0.13 eV for S-2 states. In addition to the spectral shifts (SI and S2 states), it is suggested that a charge-transfer band is appeared as a low-lying excited state above the S-1 and S-2 states. The origin of the spectrum shifts was discussed on the basis of theoretical results. (C) 2004 Elsevier B.V. All rights reserved. C1 Hokkaido Univ, Grad Sch Chem, Div Mol Chem, Sapporo, Hokkaido 0608628, Japan. Los Alamos Natl Lab, Biosci Div, Los Alamos, NM 87545 USA. RP Tachikawa, H (reprint author), Hokkaido Univ, Grad Sch Chem, Div Mol Chem, Sapporo, Hokkaido 0608628, Japan. EM hiroto@eng.hokudai.ac.jp RI Tachikawa, Hiroto/F-7560-2012 NR 12 TC 19 Z9 19 U1 0 U2 8 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0020-1693 J9 INORG CHIM ACTA JI Inorg. Chim. Acta PD JAN 25 PY 2005 VL 358 IS 2 BP 288 EP 294 DI 10.1016/j.ica.2004.07.050 PG 7 WC Chemistry, Inorganic & Nuclear SC Chemistry GA 886LP UT WOS:000226229100006 ER PT J AU Rozenak, P Sirois, E Ladna, B Birnbaum, HK Spooner, S AF Rozenak, P Sirois, E Ladna, B Birnbaum, HK Spooner, S TI Characterization of hydrogen defects forming during chemical charging in the aluminum SO JOURNAL OF ALLOYS AND COMPOUNDS LA English DT Article DE hydrogen; aluminum; vacancies; hydrogen charging; hydrogen bubbles ID THERMAL-DECOMPOSITION; HYDRIDE POWDER; SOLUBILITY; DIFFUSIVITY; DIFFRACTION; PURITY AB The behavior of hydrogen and deuterium in high-purity aluminum introduced by high-fugacity chemical techniques has been studied. The aims were to establish: (a) the presence of the hydrogen-vacancies clusters and bubbles formations, (b) their size and size distributions, (c) the symmetry of the clusters and the dependence of these parameters on the hydrogen charging conditions and on subsequent annealing procedures and (d) the kinetics of hydrogen release from these clusters and the structure of the remaining defects produced when the hydrogen is removed. The study was combined with a parallel series of experiments, which utilized secondary ion mass spectrometry (SIMS), X-ray techniques (Laue, small-angle X-ray scattering (SAXS), diffractometer measurements), transmission electron microscopy (TEM) and scanning electron microscope (SEM). The experiments revealed the existence of a large size distribution of hydrogen voids and bubbles on the surface and under the surface obtained during electrochemical and chemical charging. The depth of these defects was controlled by electrochemical and chemical charging conditions and depended on the charging time. Hydrogen nearly entered the aluminum lattice interstitially. A TEM technique revealed the existence of surface bubble from the interactions between the aluminum hydroxide with hydrogen and formed a hydrogen-vacancy complex at the surface, which diffused into the volume and then clustered to form H-2 interior bubbles. A large size (some micrometers in the diameter) to very small sizes (nanometers in the diameter) in the distribution and variety in the density of the surface bubbles was obtained. Between the densely packed surface bubbles, formation of the dense dislocations could be seen. Internal bubble with symmetrical bend contours of the height and dense distributions of dislocations was observed. (C) 2004 Elsevier B.V. All rights reserved. C1 Univ Illinois, Mat Res Lab, Urbana, IL 61801 USA. Oak Ridge Natl Lab, Div Met & Ceram, Oak Ridge, TN USA. RP Hydrogen Energy Batteries Com, Eshel 44 St,POB 195, IL-84965 Omer, Israel. EM rozenak@internet-zahav.net NR 38 TC 20 Z9 20 U1 3 U2 13 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0925-8388 EI 1873-4669 J9 J ALLOY COMPD JI J. Alloy. Compd. PD JAN 25 PY 2005 VL 387 IS 1-2 BP 201 EP 210 DI 10.1016/j.jallcom.2004.06.041 PG 10 WC Chemistry, Physical; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Chemistry; Materials Science; Metallurgy & Metallurgical Engineering GA 887BN UT WOS:000226277400040 ER PT J AU Palmblad, M Vogel, JS AF Palmblad, M Vogel, JS TI Quantitation of binding, recovery and desalting efficiency of peptides and proteins in solid phase extraction micropipette tips SO JOURNAL OF CHROMATOGRAPHY B-ANALYTICAL TECHNOLOGIES IN THE BIOMEDICAL AND LIFE SCIENCES LA English DT Article DE solid phase extraction; quantitation; recovery; peptides; proteins; accelerator mass spectrometry ID ACCELERATOR MASS-SPECTROMETRY; BIOCHEMICAL SAMPLES; PROTEOMICS; MIXTURES; GRAPHITE; C-14 AB Micropipette-tip solid phase extraction (SPE) systems are common in proteomic analyses for desalting and concentrating samples for mass spectrometry, removing interferences, and increasing sensitivity. These systems are inexpensive, disposable, and highly efficient. Here, we show micropipette-tip solid phase extraction is a direct sample preparation method for (14)C-accelerator mass spectrometry (AMS), removing salts or reagent from labeled macromolecules. We compared loading, recovery and desalting efficiency in commercially available SPE microtips using (14)C-labeled peptides and proteins, AMS, and alpha spectrometry ion energy loss quantitation. The polypropylene in the tips was nearly (14)C-free and simultaneously provided low-background carrier for AMS. The silica material did not interfere with the analysis. Alpha spectrometry provided an absolute measurement of desalting efficiency. (C) 2004 Elsevier B.V. All rights reserved. C1 Lawrence Livermore Natl Lab, Ctr Accelerator Mass Spectrometry, Livermore, CA 94551 USA. RP Palmblad, M (reprint author), Lawrence Livermore Natl Lab, Ctr Accelerator Mass Spectrometry, Livermore, CA 94551 USA. EM palmblad1@llnl.gov RI Palmblad, Magnus/B-8649-2016 OI Palmblad, Magnus/0000-0002-5865-8994 NR 14 TC 19 Z9 19 U1 2 U2 9 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 1570-0232 J9 J CHROMATOGR B JI J. Chromatogr. B PD JAN 25 PY 2005 VL 814 IS 2 BP 309 EP 313 DI 10.1016/j.jchromb.2004.10.052 PG 5 WC Biochemical Research Methods; Chemistry, Analytical SC Biochemistry & Molecular Biology; Chemistry GA 889JD UT WOS:000226438400014 PM 15639453 ER PT J AU Soloviev, SP Sweeney, JJ AF Soloviev, SP Sweeney, JJ TI Generation of electric and magnetic field during detonation of high explosive charges in boreholes SO JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH LA English DT Article ID ELECTROMAGNETIC-RADIATION; ROCK FRACTURE; EMISSION; MECHANISM AB We present experimental results of a study of electromagnetic field generation during underground detonation of high explosive charges in holes bored in sandy loam and granite. Three components of electric field (vertical component in air and two horizontal components in the soil) and three components of the magnetic induction were recorded during the field experiments. Test conditions and physicomechanical properties of the soil exert significant influence on the parameters of electromagnetic signals generated by underground explosions with masses of 2-200 kg. The electric and magnetic field experimental data are satisfactorily described by an electric dipole model with the source embedded in layered media. We used the solution for a field produced by stationary vertical and horizontal electric dipoles placed near the interface between two layers with different conductivity. The magnitude of the field source was estimated on the basis of the records of electromagnetic signals obtained at different distances from the borehole. For an underground explosion of a TNT charge with a mass of 2 kg carried out in granite the maximum estimated value of the electric dipole component is about 10(-7) C m. This estimate is more than an order of magnitude greater than that obtained for an explosion of the same mass carried out in sandy loam. C1 Russian Acad Sci, Inst Geospheres Dynam, Moscow 119334, Russia. Lawrence Livermore Natl Lab, Div Earth Sci, Livermore, CA 94550 USA. RP Soloviev, SP (reprint author), Russian Acad Sci, Inst Geospheres Dynam, Leninsky Prospect,38 Korpus 1, Moscow 119334, Russia. EM sweeney3@llnl.gov OI Qian, Liying/0000-0003-2430-1388 NR 28 TC 10 Z9 10 U1 0 U2 14 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 JAN 25 PY 2005 VL 110 IS B1 AR B01312 DI 10.1029/2004JB003223 PG 14 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 892YS UT WOS:000226686500003 ER PT J AU Yang, ZG Hou, PY AF Yang, ZG Hou, PY TI Wrinkling behavior of alumina scales formed during isothermal oxidation of Fe-Al binary alloys SO MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING LA English DT Article DE oxidation; iron alloys; alumina; oxide/alloy interface; wrinkling ID CR-AL; HIGH-TEMPERATURE; IRON ALUMINIDES; SULFUR SEGREGATION; ALPHA-AL2O3 SCALES; OXIDE SCALES; AL2O3 SCALES; Y ALLOYS; GROWTH; DIFFUSION AB The morphological development of Al2O3 scales formed on Fe-24, 28, 32, 36 and 40 at% Al alloys during isothermal oxidation at 900-1100degreesC in pure oxygen was studied by SEM, and the extent of surface undulation was quantified by AFM. In all cases, the initially formed scale was flat with a macroscopically planar scale/alloy interface. With further oxidation, the scale and the alloy undulated together, developing a convoluted interface that was often strongly depended upon alloy grain orientations. Eventually, the scale detached and buckled. Convolution was found to develop much earlier at higher oxidation temperatures and on alloys with aluminum concentrations in the disordered bcc phase field (A2) than those with the ordered bcc structure (B2), which suggests that diffusivity in the alloy is the dominating factor for Al2O3/alloy interface convolution during scale growth. (C) 2004 Elsevier B.V. All rights reserved. C1 Tsinghua Univ, Dept Mat Sci & Engn, Beijing 100084, Peoples R China. Lawrence Berkeley Lab, Div Sci Mat, Berkeley, CA 94720 USA. RP Tsinghua Univ, Dept Mat Sci & Engn, Beijing 100084, Peoples R China. EM zgyang@tsinghua.edu.cn NR 49 TC 26 Z9 26 U1 1 U2 10 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0921-5093 EI 1873-4936 J9 MAT SCI ENG A-STRUCT JI Mater. Sci. Eng. A-Struct. Mater. Prop. Microstruct. Process. PD JAN 25 PY 2005 VL 391 IS 1-2 BP 1 EP 9 DI 10.1016/j.msea.2004.05.016 PG 9 WC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Science & Technology - Other Topics; Materials Science; Metallurgy & Metallurgical Engineering GA 890UQ UT WOS:000226536800001 ER PT J AU Elmer, JW Palmer, TA Babu, SS Specht, ED AF Elmer, JW Palmer, TA Babu, SS Specht, ED TI In situ observations of lattice expansion and transformation rates of alpha and beta phases in Ti-6Al-4V SO MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING LA English DT Article DE X-ray diffraction; synchrotron radiation; thermal expansion; annealing; phase transformations; kinetics; vanadium partitioning; diffusion; lattice parameter; residual stress ID X-RAY-DIFFRACTION; TITANIUM-ALLOYS; WELDS; TRANSITIONS; SYSTEM AB In situ X-ray diffraction experiments using synchrotron radiation were performed on Ti-6Al-4V samples to directly observe the alpha --> beta phase transformation during heating. These experiments were conducted at the Advanced Photon Source (APS) using a 30 keV synchrotron X-ray beam to monitor changes in the alpha and beta phases as a function of heating time under different heating rates. The results were compared to computational thermodynamic predictions of the phase fractions versus temperature, providing information about the kinetics of the alpha --> beta transformation in Ti-6Al-4V. The measured transformation rates were shown to be consistent with a diffusion-controlled growth mechanism, whereby diffusion of V in the beta-Ti phase controls the rate. Based on the X-ray diffraction data, real time measurements of the alpha and beta phase lattice parameters were made. Dramatic differences were observed in the changes of the lattice parameters of the two phases during the transformation. These changes are believed to be due to the partitioning of V and its strong effect on the lattice parameter of the beta phase. An unexpected contraction of the lattice parameter of the beta phase was further observed during heating in the temperature range between 500 and 600degreesC. The origin of this contraction is most likely related to the annealing of residual stresses created by the different thermal expansion behaviors of the two phases. Published by Elsevier B.V. C1 Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Lawrence Livermore Natl Lab, POB 808,L-355, Livermore, CA 94551 USA. EM elmer1@llnl.gov RI Babu, Sudarsanam/D-1694-2010; Specht, Eliot/A-5654-2009 OI Babu, Sudarsanam/0000-0002-3531-2579; Specht, Eliot/0000-0002-3191-2163 NR 19 TC 58 Z9 63 U1 4 U2 34 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0921-5093 EI 1873-4936 J9 MAT SCI ENG A-STRUCT JI Mater. Sci. Eng. A-Struct. Mater. Prop. Microstruct. Process. PD JAN 25 PY 2005 VL 391 IS 1-2 BP 104 EP 113 DI 10.1016/j.msea.2004.08.084 PG 10 WC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Science & Technology - Other Topics; Materials Science; Metallurgy & Metallurgical Engineering GA 890UQ UT WOS:000226536800014 ER PT J AU Liu, C Alexander, DJ AF Liu, C Alexander, DJ TI A kinematic analysis of the angular extrusion (AE) operations SO MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING LA English DT Article DE analytical methods; angular extrusion; finite deformation ID ECAP; SHEAR; FEM AB Detailed deformation analysis of the AE process is presented, based on a finite-deformation formulation. The two basic assumptions used in the analysis are that (1) the material is incompressible, and (2) the material flow is steady state in both the incoming channel and the outgoing channel. The main objective of this study is to identify the parameters, which are consistent with finite-deformation formulation, that appropriately characterize the extrusion process and can be observed and measured through experiments. These parameters are the maximum principal stretch and its orientation angle, or equivalently, the maximum amount of shear and its orientation. The expressions of these parameters as functions of the geometry of the angular extrusion setup are given in closed forms for angular extrusions with either sharp transitions or circular transitions. Finally, we also analyze the deformation of multiple-extrusion operations. Through a specific example, we illustrate that the final deformation is not simply the summation of the deformation associated with each individual step, as suggested by the infinitesimal deformation theory. (C) 2004 Elsevier B.V. All rights reserved. C1 Los Alamos Natl Lab, Mat Sci & Technol Div, Los Alamos, NM 87545 USA. RP Liu, C (reprint author), Los Alamos Natl Lab, Mat Sci & Technol Div, Los Alamos, NM 87545 USA. EM cliu@lanl.gov NR 17 TC 2 Z9 2 U1 0 U2 0 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0921-5093 J9 MAT SCI ENG A-STRUCT JI Mater. Sci. Eng. A-Struct. Mater. Prop. Microstruct. Process. PD JAN 25 PY 2005 VL 391 IS 1-2 BP 198 EP 209 DI 10.1016/j.msea.2004.08.078 PG 12 WC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Science & Technology - Other Topics; Materials Science; Metallurgy & Metallurgical Engineering GA 890UQ UT WOS:000226536800025 ER PT J AU Cho, J Terry, SG LeSar, R Levi, CG AF Cho, J Terry, SG LeSar, R Levi, CG TI A kinetic Monte Carlo simulation of film growth by physical vapor deposition on rotating substrates SO MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING LA English DT Article DE thermal barrier coatings; physical vapor deposition; film growth; microstructure evolution; kinetic Monte Carlo ID THERMAL BARRIER COATINGS; COMPUTER-SIMULATION; THIN-FILMS; EB-PVD; SURFACE; MICROSTRUCTURE; DIFFUSION; ENERGY; OXIDE; DIAMOND AB Film growth by physical vapor deposition on rotating substrates is modeled via a kinetic Monte Carlo algorithm on a two-dimensional hexagonal lattice. The motivation is to provide insight on the evolution of porosity during the deposition of thermal barrier coatings (TBCs). The model is implemented on an atomic scale that incorporates the effect of surface diffusion as well as the interplay between surface topography and the changing vapor incidence angle. It is shown that substrate rotation generates voids with a periodicity dependent on the amount of material deposited per revolution. The onset of pore formation and morphology of the pores are linked to the presence of shadowing features on the surface, either in the form of stochastic or crystallographic peaks and valleys evolving during columnar growth, or pre-existing roughness typical of polycrystalline oxide substrates. In addition, various forms of anisotropy develop in the microstructure as a result of the "sunrise-sunset" pattern of vapor incidence characteristic of TBC deposition on, for example, turbine airfoils. Comparison with observations on actual TBCs reveals that the simulations, in spite of their simplicity, capture several key microstructural features characteristic of these complex films. (C) 2004 Elsevier B.V. All rights reserved. C1 Univ Calif Santa Barbara, Coll Engn, Dept Mat, Santa Barbara, CA 93106 USA. SUNY Binghamton, Dept Mech Engn, Binghamton, NY 13902 USA. Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. RP Univ Calif Santa Barbara, Coll Engn, Dept Mat, Santa Barbara, CA 93106 USA. EM levic@engineering.ucsb.edu RI LeSar, Richard/G-1609-2012 NR 44 TC 26 Z9 27 U1 2 U2 13 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0921-5093 EI 1873-4936 J9 MAT SCI ENG A-STRUCT JI Mater. Sci. Eng. A-Struct. Mater. Prop. Microstruct. Process. PD JAN 25 PY 2005 VL 391 IS 1-2 BP 390 EP 401 DI 10.1016/j.msea.2004.09.015 PG 12 WC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Science & Technology - Other Topics; Materials Science; Metallurgy & Metallurgical Engineering GA 890UQ UT WOS:000226536800044 ER PT J AU Balch, DK O'Dwyer, JG Davis, GR Cady, CM Gray, GT Dunand, DC AF Balch, DK O'Dwyer, JG Davis, GR Cady, CM Gray, GT Dunand, DC TI Plasticity and damage in aluminum syntactic foams deformed under dynamic and quasi-static conditions SO MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING LA English DT Article DE syntactic foam; aluminum alloys; energy absorption dynamic compression; strain rate sensitivity; X-ray tomography ID CLOSED-CELL ALUMINUM; COMPRESSIVE DEFORMATION; MATRIX COMPOSITES; ENERGY-ABSORPTION; ALLOY FOAMS; FLY-ASH; TOMOGRAPHY; MANUFACTURE; MECHANISMS; BEHAVIOR AB Syntactic foams were fabricated by liquid metal infiltration of commercially pure and 7075 aluminum into preforms of hollow ceramic microspheres. The foams exhibited peak strengths during quasi-static compression ranging from - 100 to -230 MPa, while dynamic compression loading showed a 10-30% increase in peak strength magnitude, with strain rate sensitivities similar to those of aluminum-matrix composite materials. X-ray tomographic investigation of the post-compression loaded foam microstructures revealed sharp differences in deformation modes, with the unalloyed-Al foam failing initially by matrix deformation, while the alloy-matrix foams failed more abruptly through the formation of sharp crush bands oriented at about 45degrees to the compression axis. These foams displayed pronounced energy-absorbing capabilities, suggesting their potential use in packaging applications or for impact protection; proper tailoring of matrix and microsphere strengths would result in optimized syntactic foam properties. (C) 2004 Elsevier B.V. All rights reserved. C1 Northwestern Univ, Evanston, IL 60201 USA. Waterford Inst Technol, Waterford, Ireland. Univ London, Queen Mary, London WC1E 7HU, England. Los Alamos Natl Lab, Los Alamos, NM USA. RP Dunand, DC (reprint author), Northwestern Univ, Evanston, IL 60201 USA. EM dunand@northwestern.edu RI Dunand, David/B-7515-2009; OI Dunand, David/0000-0001-5476-7379 NR 37 TC 124 Z9 127 U1 7 U2 37 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0921-5093 J9 MAT SCI ENG A-STRUCT JI Mater. Sci. Eng. A-Struct. Mater. Prop. Microstruct. Process. PD JAN 25 PY 2005 VL 391 IS 1-2 BP 408 EP 417 DI 10.1016/j.msea.2004.09.012 PG 10 WC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Science & Technology - Other Topics; Materials Science; Metallurgy & Metallurgical Engineering GA 890UQ UT WOS:000226536800046 ER PT J AU Kiran, B Bulusu, S Zhai, HJ Yoo, S Zeng, XC Wang, LS AF Kiran, B Bulusu, S Zhai, HJ Yoo, S Zeng, XC Wang, LS TI Planar-to-tubular structural transition in boron clusters: B-20 as the embryo of single-walled boron nanotubes SO PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA LA English DT Article DE photoelectron spectroscopy; density functional calculation; global minimum search ID PHOTOELECTRON-SPECTROSCOPY; AB-INITIO; SILICON CLUSTERS; CARBON CLUSTERS; GEOMETRY; CHAINS; N=2-14; RINGS AB Experimental and computational simulations revealed that boron clusters, which favor planar (2D) structures up to 18 atoms, prefer 3D structures beginning at 20 atoms. Using global optimization methods, we found that the B-20 neutral cluster has a double-ring tubular structure with a diameter of 5.2 Angstrom. For the B-20(-) anion, the tubular structure is shown to be isoenergetic to 2D structures, which were observed and confirmed by photoelectron spectroscopy. The 2D-to-3D structural transition observed at B-20, reminiscent of the ring-to-fullerene transition at C-20 in carbon clusters, suggests it may be considered as the embryo of the thinnest single-walled boron nanotubes. C1 Washington State Univ, Dept Phys, Richland, WA 99352 USA. Pacific NW Natl Lab, Div Chem Sci, Richland, WA 99352 USA. Univ Nebraska, Dept Chem, Lincoln, NE 68588 USA. Univ Nebraska, Ctr Mat Res & Anal, Lincoln, NE 68588 USA. RP Zeng, XC (reprint author), Washington State Univ, Dept Phys, 2710 Univ Dr, Richland, WA 99352 USA. EM xczeng@phasel.unl.edu; ls.wang@pnl.gov NR 27 TC 241 Z9 242 U1 3 U2 43 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 JAN 25 PY 2005 VL 102 IS 4 BP 961 EP 964 DI 10.1073/pnas.0408132102 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 891YW UT WOS:000226617900002 PM 15644450 ER PT J AU Benzerara, K Yoon, TH Menguy, N Tyliszczak, T Brown, GE AF Benzerara, K Yoon, TH Menguy, N Tyliszczak, T Brown, GE TI Nanoscale environments associated with bioweathering of a Mg-Fe-pyroxene SO PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA LA English DT Article DE aluminosilicate; biomineralization; geomicrobiology; STXM; Urey reaction ID TRANSMISSION X-RAY; MINERAL DISSOLUTION; MICROBIAL POLYSACCHARIDES; OXIDIZING BACTERIA; SILICATE MINERALS; WEATHERING RATES; EDGE; RHIZOSPHERE; ABSORPTION; MICROSCOPY AB Microorganisms are believed to create microenvironments leading to reaction products not predictable from equilibrium thermodynamics and to unique biomineral morphologies. Unambiguous evidence for such environments is, however, rare in natural samples. We have used scanning transmission x-ray microscopy and spectromicroscopy at the sub-40-nm scale, coupled with transmission electron microscopy, to examine bioweathering products on a meteoritic Fe-Mg-orthopyroxene colonized by a filamentous microorganism. Our measurements reveal an amorphous Al-rich layer beneath the microorganism, calcium carbonates of unique morphology intimately associated with polysaccharicles adjacent to the microorganism, and regions surrounding the microorganism with different iron oxidation states. Our results confirm the presence of different microenvironments at this microorganism-mineral interface and provide unique nanometer-scale views of microbially controlled pyroxene weathering products. C1 Stanford Univ, Dept Geog & Environm Sci, Surface & Aqueous Geochem Grp, Stanford, CA 94305 USA. CNRS, UMR 7590, Lab Mineral Cristallog, F-75252 Paris, France. Inst Phys Globe, F-75252 Paris, France. Lawrence Berkeley Lab, Div Chem Sci, Berkeley, CA 94720 USA. Stanford Linear Accelerator Ctr, Stanford Synchrotron Radiat Lab, Menlo Pk, CA 94025 USA. RP Benzerara, K (reprint author), Stanford Univ, Dept Geog & Environm Sci, Surface & Aqueous Geochem Grp, Stanford, CA 94305 USA. EM benzerar@stanford.edu RI MENGUY, Nicolas/F-5607-2012; Benzerara, Karim/J-1532-2016; IMPMC, Geobio/F-8819-2016 OI MENGUY, Nicolas/0000-0003-4613-2490; Benzerara, Karim/0000-0002-0553-0137; NR 34 TC 58 Z9 69 U1 2 U2 34 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 JAN 25 PY 2005 VL 102 IS 4 BP 979 EP 982 DI 10.1073/pnas.0409029102 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 891YW UT WOS:000226617900006 PM 15647362 ER PT J AU Alsem, DH Stach, EA Muhlstein, CL Ritchie, RO AF Alsem, DH Stach, EA Muhlstein, CL Ritchie, RO TI Fatigue failure in thin-film polycrystalline silicon is due to subcritical cracking within the oxide layer SO APPLIED PHYSICS LETTERS LA English DT Article ID HIGH-CYCLE FATIGUE; SINGLE-CRYSTAL SILICON; POLYSILICON; MECHANISM; FRACTURE; SYSTEMS; MEMS AB It has been established that microelectromechanical systems created from polycrystalline silicon thin films are subject to cyclic fatigue. Prior work by the authors has suggested that although bulk silicon is not susceptible to fatigue failure in ambient air, fatigue in micron-scale silicon is a result of a "reaction-layer" process, whereby high stresses induce a thickening of the post-release oxide at stress concentrations such as notches, which subsequently undergoing moisture-assisted cracking. However, there exists some controversy regarding the post-release oxide thickness of the samples used in the prior study. In this letter, we present data from devices from a more recent fabrication run that confirm our prior observations. Additionally, new data from tests in high vacuum show that these devices do not fatigue when oxidation and moisture are suppressed. Each of these observations lends credence to the "reaction-layer" mechanism. (C) 2005 American Institute of Physics. C1 Univ Calif Berkeley, Dept Mat Sci & Engn, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Natl Ctr Electron Microscopy, Berkeley, CA 94720 USA. Penn State Univ, Dept Mat Sci & Engn, University Pk, PA 16802 USA. RP Alsem, DH (reprint author), Univ Calif Berkeley, Dept Mat Sci & Engn, Berkeley, CA 94720 USA. RI Stach, Eric/D-8545-2011; Ritchie, Robert/A-8066-2008; OI Stach, Eric/0000-0002-3366-2153; Ritchie, Robert/0000-0002-0501-6998; Muhlstein, Christopher/0000-0002-5928-068X NR 19 TC 30 Z9 32 U1 1 U2 5 PU AMER INST PHYSICS PI MELVILLE PA 1305 WALT WHITMAN RD, STE 300, MELVILLE, NY 11747-4501 USA SN 0003-6951 EI 1077-3118 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD JAN 24 PY 2005 VL 86 IS 4 AR 041914 DI 10.1063/1.1856689 PG 3 WC Physics, Applied SC Physics GA 894AE UT WOS:000226761400031 ER PT J AU Auciello, O Fan, W Kabius, B Saha, S Carlisle, JA Chang, RPH Lopez, C Irene, EA Baragiola, RA AF Auciello, O Fan, W Kabius, B Saha, S Carlisle, JA Chang, RPH Lopez, C Irene, EA Baragiola, RA TI Hybrid titanium-aluminum oxide layer as alternative high-k gate dielectric for the next generation of complementary metal-oxide-semiconductor devices SO APPLIED PHYSICS LETTERS LA English DT Article AB Research is focused on finding reliable high-dielectric constant (k) oxides with high capacitance and all critical properties required for the next generation of complementary metal-oxide-semiconductor (CMOS) gates. A trade-off between dielectric constant and band-offset height is generally observed on gate oxides. Combining TiO2 and Al2O3, with the two extremes of high permittivity (k) and high band offset, we produced a TixAl1-xOy (TAO) oxide layer with k=similar to30 and low dielectric leakage for a next generation of high-k dielectric gates. We developed a low temperature oxidation process, following room temperature sputter-deposition of TiAl layers, to produce ultrathin TAO layers on Si with subatomic or no SiO2 or silicide interface formation. We demonstrated TAO layers with <0.5 nm equivalent oxide thickness on Si and thermal stability under rapid thermal annealing up to about 950 degreesC. The data presented here provide insights into fundamental physics and materials science of the TAO layer and its potential application as gate dielectric for the next generation of CMOS devices. (C) 2005 American Institute of Physics. C1 Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. Northwestern Univ, Dept Mat Sci & Engn, Evanston, IL 60208 USA. Univ N Carolina, Dept Chem, Chapel Hill, NC 27599 USA. Univ Virginia, Dept Mat Sci, Charlottesville, VA 22904 USA. RP Auciello, O (reprint author), Argonne Natl Lab, Div Mat Sci, 9700 S Cass Ave, Argonne, IL 60439 USA. EM auciello@anl.gov RI Chang, R.P.H/B-7505-2009 NR 11 TC 55 Z9 58 U1 0 U2 17 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 JAN 24 PY 2005 VL 86 IS 4 AR 042904 DI 10.1063/1.1856137 PG 3 WC Physics, Applied SC Physics GA 894AE UT WOS:000226761400056 ER PT J AU Cao, HJ Liu, CY Ling, H Deng, H Benavidez, M Smagley, VA Caldwell, RB Peake, GM Smolyakov, GA Eliseev, PG Osinski, M AF Cao, HJ Liu, CY Ling, H Deng, H Benavidez, M Smagley, VA Caldwell, RB Peake, GM Smolyakov, GA Eliseev, PG Osinski, M TI Frequency beating between monolithically integrated semiconductor ring lasers SO APPLIED PHYSICS LETTERS LA English DT Article ID OPERATION; BISTABILITY; RESONATOR; CW AB Optoelectronic integrated circuits incorporating a pair of optically independent large-cavity semiconductor ring lasers (SRLs), directional couplers, waveguides, Y-junction mixer, and photodetectors are demonstrated. Counterclockwise and clockwise output beams from the two SRLs are collected separately and mixed prior to detection. Frequency beating between modes of two SRLs is measured. The beat frequency is fine-tuned by an integrated Joule heater, designed for thermal control of the lasing wavelength. No signs of frequency lock-in in the vicinity of zero detuning are observed, which makes this structure a promising candidate for applications in ring laser gyros and optical rotation sensors. (C) 2005 American Institute of Physics. C1 Univ New Mexico, Ctr High Technol Mat, Albuquerque, NM 87106 USA. Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Cao, HJ (reprint author), Univ New Mexico, Ctr High Technol Mat, 1313 Goddard SE, Albuquerque, NM 87106 USA. EM osinski@chtm.unm.edu NR 12 TC 20 Z9 20 U1 0 U2 9 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD JAN 24 PY 2005 VL 86 IS 4 AR 041101 DI 10.1063/1.1853532 PG 3 WC Physics, Applied SC Physics GA 894AE UT WOS:000226761400001 ER PT J AU Chekh, Y Goncharov, A Protsenko, I Brown, IG AF Chekh, Y Goncharov, A Protsenko, I Brown, IG TI Effect of the electrostatic plasma lens on the emittance of a high-current heavy ion beam SO APPLIED PHYSICS LETTERS LA English DT Article ID LARGE-AREA AB We describe measurements we have made of the emittance of a high-current, moderate-energy ion beam after transport through a permanent-magnet electrostatic plasma lens. The results indicate the absence of emittance growth due to the lens, when the lens is adjusted for optimal beam focusing. The measured normalized emittance for a 32 keV Cu2+ ion beam formed by a vacuum arc ion source was 0.6 pi mm mrad at a beam current of 50 mA rising more-or-less linearly to 2.2 pi mm mrad at 250 mA, and was conserved in beam transport through the lens. These results have significance for the application of high-current ion sources and the electrostatic plasma lens to particle accelerator injection. (C) 2005 American Institute of Physics. C1 Natl Acad Sci Ukraine, Inst Phys, UA-03028 Kiev, Ukraine. Lawrence Berkeley Lab, Berkeley, CA 94708 USA. RP Chekh, Y (reprint author), Natl Acad Sci Ukraine, Inst Phys, 46 Prosp Nauky, UA-03028 Kiev, Ukraine. EM gonchar@iop.kiev.ua NR 13 TC 9 Z9 9 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 JAN 24 PY 2005 VL 86 IS 4 AR 041502 DI 10.1063/1.1855428 PG 3 WC Physics, Applied SC Physics GA 894AE UT WOS:000226761400017 ER PT J AU Lany, S Zhao, YJ Persson, C Zunger, A AF Lany, S Zhao, YJ Persson, C Zunger, A TI Halogen n-type doping of chalcopyrite semiconductors SO APPLIED PHYSICS LETTERS LA English DT Article ID SOLAR-CELLS; TOTAL-ENERGY; THIN-FILMS; EFFICIENCY; CUINSE2; CULNSE2 AB We theoretically identify the chemical thermodynamic boundary conditions that will produce n-type CuInSe2 via halogen doping. Remarkably, we find that due to the low formation energies of the intrinsic defects, V-Cu and In-Cu in CuInSe2, the growth conditions that maximize the halogen donor incorporation do not yield n-type conductivity, whereas the conditions that maximize the concentration of the intrinsic donor In-Cu do yield n-type conductivity. Under the latter conditions, however, the contribution of the halogen donors to the net donor concentration stays significantly below that of In-Cu. (C) 2005 American Institute of Physics. C1 Natl Renewable Energy Lab, Golden, CO 80401 USA. RP Lany, S (reprint author), Natl Renewable Energy Lab, Golden, CO 80401 USA. EM Alex_Zunger@nrel.gov RI Zhao, Yu-Jun/A-1219-2011; Zunger, Alex/A-6733-2013; OI Zhao, Yu-Jun/0000-0002-6923-1099; Lany, Stephan/0000-0002-8127-8885 NR 16 TC 18 Z9 18 U1 1 U2 15 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 JAN 24 PY 2005 VL 86 IS 4 AR 042109 DI 10.1063/1.1854218 PG 3 WC Physics, Applied SC Physics GA 894AE UT WOS:000226761400040 ER PT J AU Park, S Zhang, X Misra, A Thompson, JD Fitzsimmons, MR Lee, S Falco, CM AF Park, S Zhang, X Misra, A Thompson, JD Fitzsimmons, MR Lee, S Falco, CM TI Tunable magnetic anisotropy of ultrathin Co layers SO APPLIED PHYSICS LETTERS LA English DT Article ID ALLOY-FILMS; SUPERLATTICES; SCATTERING; SURFACE; FE AB We prepared multilayers, consisting of an epitaxial Au/Co/Au/Cu(111) architecture on Si(111) substrates, to understand the magnetic anisotropy of an ultrathin Co layer in relation to its structure. The room-temperature magnetization of an 8-monolayer (ML)-thick Co layer is predominately either in-plane or out-of-plane depending upon the thickness of the Au underlayer. Specifically, for a Co film grown on a 2-ML-thick Au, the Co film has a distorted fcc structure and in-plane magnetic anisotropy. For a Co film grown on a 6-ML-thick Au, the Co film has a distorted hcp structure and out-of-plane magnetic anisotropy. (C) 2005 American Institute of Physics. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Inha Univ, Dept Phys, Inchon, South Korea. Univ Arizona, Ctr Opt Sci, Tucson, AZ 85721 USA. RP Park, S (reprint author), Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. EM spark@lanl.gov RI Lujan Center, LANL/G-4896-2012; Misra, Amit/H-1087-2012 NR 21 TC 13 Z9 13 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 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD JAN 24 PY 2005 VL 86 IS 4 AR 042504 DI 10.1063/1.1850592 PG 3 WC Physics, Applied SC Physics GA 894AE UT WOS:000226761400049 ER PT J AU Wang, ZW Zhao, YS Lazor, P Annersten, H Saxena, SK AF Wang, ZW Zhao, YS Lazor, P Annersten, H Saxena, SK TI In situ pressure Raman spectroscopy and mechanical stability of superhard boron suboxide SO APPLIED PHYSICS LETTERS LA English DT Article ID HIGH-TEMPERATURE; AMORPHOUS BORON; B6O; SCATTERING; NITRIDE; SYSTEM; B2O3 AB In situ Raman spectroscopy was used to explore the mechanical stability and electronic properties of superhard boron suboxide (B6O) under nonhydrostatic pressure. B6O stabilizes in a rhombohedral structure (R (3) over barm) to the peak pressure of 90 GPa. The icosahedra-chain (B-O) phonon at 274 cm(-1) exhibits a negative pressure dependent profile of -0.21 cm(-1)/GPa, while the intraicosahedral vibrations (B-B) between 400 and 1100 cm(-1) and the intericosahedral phonon at 1141 cm(-1) display 0.7-2.3 and 3.8 cm(-1)/GPa, respectively. The small pressure dependencies of intraicosahedral modes resulting from the crystal lattice are significant indications of the low compressibility of B6O. Upon decompression to 3.3 GPa, crystalline B6O transforms to the amorphous boron oxide and glassy boron. The structure instability of superhard B6O upon release of pressure implies its critical weakness for applications in harsh environments of dynamic impacts and high stress concentrations.(C) 2005 American Institute of Physics. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Uppsala Univ, Inst Earth Sci, SE-75236 Uppsala, Sweden. Florida Int Univ, CeSMEC, Miami, FL 33199 USA. RP Wang, ZW (reprint author), Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. EM z_wang@lanl.gov RI Lujan Center, LANL/G-4896-2012 NR 15 TC 8 Z9 8 U1 2 U2 21 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 JAN 24 PY 2005 VL 86 IS 4 AR 041911 DI 10.1063/1.1857091 PG 3 WC Physics, Applied SC Physics GA 894AE UT WOS:000226761400028 ER PT J AU Yoo, YK Xue, Q Lee, HC Cheng, SF Xiang, XD Dionne, GF Xu, SF He, J Chu, YS Preite, SD Lofland, SE Takeuchi, I AF Yoo, YK Xue, Q Lee, HC Cheng, SF Xiang, XD Dionne, GF Xu, SF He, J Chu, YS Preite, SD Lofland, SE Takeuchi, I TI Bulk synthesis and high-temperature ferromagnetism of (In1-xFex)(2)O3-sigma with Cu co-doping SO APPLIED PHYSICS LETTERS LA English DT Article ID FILMS; ZNO AB The synthesis and magnetic properties of (In1-xFex)(2)O3-sigma bulk ceramics with Cu co-doping are reported. Magnetic Fe ions are found to have high thermodynamic solubility (up to 20%) in the In2O3 host compound. The lattice constant decreases almost linearly as Fe doping concentration increases indicating the incorporation of Fe ions into the host lattice. The samples with high Fe concentration annealed under Ar reduced atmosphere were found to be ferromagnetic, and the Curie temperature is around 750 K. The extensive structural and magnetic studies rule out the possibility that the observed magnetism is derived from magnetic impurity phases. (C) 2005 American Institute of Physics. C1 Intematix Corp, Moraga, CA 94556 USA. SRI Int, Menlo Pk, CA 94025 USA. Argonne Natl Lab, Adv Photon Source, Argonne, IL 60439 USA. Rowan Coll, Ctr Mat Res & Educ, Glassboro, NJ 08028 USA. Univ Maryland, Dept Mat Sci & Engn, College Pk, MD 20742 USA. Univ Maryland, Ctr Superconduct Res, College Pk, MD 20742 USA. RP Xiang, XD (reprint author), Intematix Corp, 351 Rheem Blvd, Moraga, CA 94556 USA. EM xdxiang@intematix.com RI Xiang, Xiaodong/A-9445-2012; Xiang, Xiaodong/A-5936-2017; OI Lofland, Samuel/0000-0002-1024-5103 NR 17 TC 105 Z9 109 U1 0 U2 14 PU AMER INST PHYSICS PI MELVILLE PA 1305 WALT WHITMAN RD, STE 300, MELVILLE, NY 11747-4501 USA SN 0003-6951 EI 1077-3118 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD JAN 24 PY 2005 VL 86 IS 4 AR 042506 DI 10.1063/1.1854720 PG 3 WC Physics, Applied SC Physics GA 894AE UT WOS:000226761400051 ER PT J AU Yu, KM Walukiewicz, W Wojtowicz, T Denlinger, J Scarpulla, MA Liu, X Furdyna, JK AF Yu, KM Walukiewicz, W Wojtowicz, T Denlinger, J Scarpulla, MA Liu, X Furdyna, JK TI Effect of film thickness on the incorporation of Mn interstitials in Ga1-xMnxAs SO APPLIED PHYSICS LETTERS LA English DT Article ID CURIE-TEMPERATURE; SEMICONDUCTORS; (GA,MN)AS AB We have investigated the effect of film thickness on the distribution of Mn atoms at various lattice sites in Ga1-xMnxAs thin films. We find that the growth surface acts as a sink facilitating the outdiffusion of Mn interstitials (Mn-I), and thus reducing its concentration in the film. The outdiffused Mn-I accumulate on the surface in a surface oxide layer and do not participate in the ferromagnetism of the film. For thin films less than 15 nm thick, no Mn-I can be detected. Because of the absence of compensating Mn-I defects, higher T-C can be achieved for such extremely thin Ga1-xMnxAs layers. These results agree with our previously suggested Fermi-level-governed upper limit of the T-C of III-Mn-V ferromagnetic semiconductors. (C) 2005 American Institute of Physics. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Elect Mat Program, Berkeley, CA 94720 USA. Polish Acad Sci, Inst Phys, PL-02668 Warsaw, Poland. Univ Notre Dame, Dept Phys, Notre Dame, IN 46556 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Adv Light Source, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Mat Sci & Engn, Berkeley, CA 94720 USA. RP Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Elect Mat Program, Berkeley, CA 94720 USA. EM kmyu@lbl.gov RI Scarpulla, Michael/C-7941-2009; Yu, Kin Man/J-1399-2012; Wojtowicz, Tomasz/A-2887-2017 OI Yu, Kin Man/0000-0003-1350-9642; NR 17 TC 24 Z9 24 U1 0 U2 2 PU AMER INST PHYSICS PI MELVILLE PA 1305 WALT WHITMAN RD, STE 300, MELVILLE, NY 11747-4501 USA SN 0003-6951 EI 1077-3118 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD JAN 24 PY 2005 VL 86 IS 4 AR 042102 DI 10.1063/1.1855430 PG 3 WC Physics, Applied SC Physics GA 894AE UT WOS:000226761400033 ER PT J AU Ballard, JB Dai, XC Arrowsmith, AN Huwel, L Stauffer, HU Leone, SR AF Ballard, JB Dai, XC Arrowsmith, AN Huwel, L Stauffer, HU Leone, SR TI Observation of wave packets with simultaneous electronic, vibrational, and rotational degrees of freedom in Li-2 SO CHEMICAL PHYSICS LETTERS LA English DT Article ID OPTICAL DOUBLE-RESONANCE; CHEMICAL-REACTION DYNAMICS; RYDBERG STATES; LASER CONTROL; SHELF STATE; LI-7(2); PHASE; PREDISSOCIATION; FEMTOCHEMISTRY; PERTURBATION AB Using ultrafast pump-probe spectroscopy, we observe quantum beats between rovibrational states located on the uncoupled bound G(1)Pi(g)(divided by) and F(1)Sigma(g)(divided by) electronic curves of Li-2. From a pure launch state (A(1)Sigma(u)(+) v(A), J(A) = 11, 28), a wave packet is prepared using the output from a visible ultrafast optical parametric amplifier and is photoionized by an 800 nm ultrafast pulse. As the OPA wavelength is scanned, a vibrational progression of rotational quantum beats on the G curve is observed. At energies around 35000 cm(-1), in addition to rotational beats on the G curve, vibrational, rotational, and electronic beating between the G and F curves is observed. (C) 2004 Elsevier B.V. All rights reserved. C1 Univ Colorado, Natl Inst Stand & Technol, JILA, Boulder, CO 80309 USA. Univ Colorado, Dept Chem & Biochem, Boulder, CO 80309 USA. Univ Colorado, Dept Phys, Boulder, CO 80309 USA. Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Leone, SR (reprint author), Univ Colorado, Natl Inst Stand & Technol, JILA, Boulder, CO 80309 USA. EM jballard@uiuc.edu; srl@cchem.berkeley.edu RI Dai, Xingcan/B-3556-2014; OI Huwel, Lutz/0000-0003-0370-3521 NR 33 TC 3 Z9 4 U1 1 U2 7 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 JAN 24 PY 2005 VL 402 IS 1-3 BP 27 EP 31 DI 10.1016/j.cplett.2004.11.128 PG 5 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 889YX UT WOS:000226479900006 ER PT J AU Canton, SE Kukk, E Bozek, JD Cubaynes, D Berrah, N AF Canton, SE Kukk, E Bozek, JD Cubaynes, D Berrah, N TI Imaging wavepacket interferences using Auger resonant Raman spectroscopy SO CHEMICAL PHYSICS LETTERS LA English DT Article ID VIBRATIONAL STRUCTURE; DECAY SPECTRA; ATOMIC PEAKS; EXCITATION; SCATTERING; STATES; HCL; MOLECULES; DYNAMICS; COLLAPSE AB Novel interference effects are observed in the Auger resonant Raman transitions of core-excited HF. Pronounced oscillations, controlled by detuning above the resonance maximum, appear in the spectator decay spectra of the dissociating molecule. Using predictions from the time-dependent theory of the resonant inelastic Raman scattering, these observations are explained by a favorable spatial localization of the nuclear wavepacket in the intermediate state during its creation. This phenomenon should occur whenever photoexcitation, electronic decay and nuclear dynamics have comparable time scales. (C) 2004 Elsevier B.V. All rights reserved. C1 Univ Oulu, Dept Phys Sci, FIN-90570 Oulu, Finland. Univ Paris 11, CNRS, LURE, F-91405 Orsay, France. Univ Paris 11, LIXAM, F-91405 Orsay, France. Univ Calif Berkeley, Lawrence Berkeley Natl Lab, ALS, Adv Light Source, Berkeley, CA 94720 USA. Western Michigan Univ, Dept Phys, Kalamazoo, MI 49008 USA. RP Kukk, E (reprint author), Univ Oulu, Dept Phys Sci, FIN-90570 Oulu, Finland. EM edwin.kukk@oulu.fi RI Bozek, John/E-4689-2010; Bozek, John/E-9260-2010; Canton, Sophie/A-8432-2016 OI Bozek, John/0000-0001-7486-7238; NR 31 TC 1 Z9 1 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0009-2614 J9 CHEM PHYS LETT JI Chem. Phys. Lett. PD JAN 24 PY 2005 VL 402 IS 1-3 BP 143 EP 148 DI 10.1016/j.cplett.2004.12.017 PG 6 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 889YX UT WOS:000226479900028 ER PT J AU Tang, YJ Kassel, WS Zakharov, LN Rheingold, AL Kemp, RA AF Tang, YJ Kassel, WS Zakharov, LN Rheingold, AL Kemp, RA TI Insertion reactions of carbon dioxide into Zn-N bonds: Syntheses and structures of tetrameric and dimeric alkylzinc carbamato complexes SO INORGANIC CHEMISTRY LA English DT Article ID DIIMINATE ZINC CATALYSTS; X-RAY; ALTERNATING COPOLYMERIZATION; CRYSTAL-STRUCTURES; N,N-DIALKYLCARBAMATO COMPLEXES; MAGNESIUM COMPLEXES; MOLECULAR-STRUCTURE; CO2; EPOXIDES; DERIVATIVES AB The formal insertions of carbon dioxide into a series of methylzinc dialkylamide complexes (MeZnNR2) initially form solvent-free, tetrameric zinc carbamato complexes [Me4Zn4(O2CNR2)(4)] (NR2 = N(i-Pr)(2) (1), N(i-Bu)(2) (2), and piperidinyl (3)). These compounds have been characterized by traditional techniques as well as by single-crystal X-ray diffraction analyses. The tetrameric backbones seen in the solid state for 1-3 were structurally similar to each other. Addition of excess pyridine (py) to 1-3 breaks apart the tetramers and converts them into solvated dimeric species [Me2Zn2(O2CNR2)(2)(py)(2)] (NR2 = N(i-Pr)(2) (4), N(i-Bu)(2) (5), and piperidinyl (6)). X-ray crystallographic analyses of 4 and 5 confirmed the dimeric structure in the solid state. This study significantly increases the number of well-characterized zinc carbamates prepared via CO2 insertion into zinc amides. C1 Univ New Mexico, Dept Chem, Albuquerque, NM 87131 USA. Univ Calif San Diego, Dept Chem & Biochem, La Jolla, CA 92093 USA. Sandia Natl Labs, Adv Mat Lab, Albuquerque, NM 87106 USA. RP Kemp, RA (reprint author), Univ New Mexico, Dept Chem, Albuquerque, NM 87131 USA. EM rakemp@unm.edu NR 38 TC 41 Z9 41 U1 3 U2 10 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 JAN 24 PY 2005 VL 44 IS 2 BP 359 EP 364 DI 10.1021/ic048830r PG 6 WC Chemistry, Inorganic & Nuclear SC Chemistry GA 889LF UT WOS:000226443800029 PM 15651882 ER PT J AU Beane, SR Malheiro, M McGovern, JA Phillips, DR van Kolck, U AF Beane, SR Malheiro, M McGovern, JA Phillips, DR van Kolck, U TI Compton scattering on the proton, neutron, and deuteron in chiral perturbation theory to O(Q(4)) SO NUCLEAR PHYSICS A LA English DT Review ID EFFECTIVE-FIELD THEORY; NUCLEON-NUCLEON-SCATTERING; PION-PHOTOPRODUCTION; MAGNETIC POLARIZABILITIES; ELECTROMAGNETIC POLARIZABILITIES; PHENOMENOLOGICAL LAGRANGIANS; ELECTRIC POLARIZABILITY; DISPERSION-RELATIONS; 2-NUCLEON SYSTEM; FORCES AB We study Compton scattering in systems with A = 1 and 2 using chiral perturbation theory up to fourth order. For the proton we fit the two undetermined parameters in the O(Q(4)) gammap amplitude of McGovern to experimental data in the region omega,root\t\ less than or equal to 180 MeV, obtaining a x(2)/d.o.f. of 133/113. This yields a model-independent extraction of proton polarizabilities based solely on low-energy data: alpha(p) = (12.1 +/- 1.1(stat.)) (+0.5)(-0.5)(theory) and beta(p) = (3.4 +/- 1.1(stat.)) (+0.1)(-0.1) (theory), both in units of 10(-4) fm(3). We also compute Compton scattering on deuterium to O(Q(4)). The gammad amplitude is a sum of one- and two-nucleon mechanisms, and contains two undetermined parameters, which are related to the isoscalar nucleon polarizabilities. We fit data points from three recent gammad scattering experiments with a x(2)/d.o.f. = 26.6/20, and find alpha(N) = (13.0 +/- 1.9 (stat.)) (+3.9)(-1.5) (theory) and a beta(N) that is consistent with zero within sizable error bars. (C) 2004 Elsevier B.V. All rights reserved. C1 Ohio Univ, Dept Phys & Astron, Athens, OH 45701 USA. Univ New Hampshire, Dept Phys, Durham, NH 03824 USA. Jefferson Lab, Newport News, VA 23606 USA. Univ Fed Fluminense, Inst Fis, BR-24210340 Niteroi, RJ, Brazil. Univ Manchester, Dept Phys & Astron, Manchester M13 9PL, Lancs, England. Univ Arizona, Dept Phys, Tucson, AZ 85721 USA. Brookhaven Natl Lab, BNL Res Ctr, RIKEN, Upton, NY 11973 USA. Univ Washington, Dept Phys, Seattle, WA 98195 USA. RP Ohio Univ, Dept Phys & Astron, Athens, OH 45701 USA. EM phillips@phy.ohiou.edu RI Malheiro, Manuel/C-4943-2013; OI McGovern, Judith/0000-0001-8364-1724 NR 102 TC 51 Z9 52 U1 0 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 JAN 24 PY 2005 VL 747 IS 2-4 BP 311 EP 361 DI 10.1016/j.nuclphysa.2004.09.068 PG 51 WC Physics, Nuclear SC Physics GA 886HR UT WOS:000226218000008 ER PT J AU Epelbaum, E Glockle, W Meissner, UG AF Epelbaum, E Glockle, W Meissner, UG TI The two-nucleon system at next-to-next-to-next-to-leading order SO NUCLEAR PHYSICS A LA English DT Review ID EFFECTIVE-FIELD THEORY; CHIRAL PERTURBATION-THEORY; PROTON-PROTON SCATTERING; PION-NUCLEON SCATTERING; PHASE-SHIFT ANALYSIS; CHARGE-INDEPENDENCE BREAKING; DIFFERENTIAL CROSS-SECTION; ASYMPTOTIC D-STATE; NEUTRON-PROTON; ISOSPIN VIOLATION AB We consider the two-nucleon system at next-to-next-to-next-to-leading order ((NLO)-L-3) in chiral effective field theory. The two-nucleon potential at (NLO)-L-3 consists of one-, two- and three-pion exchanges and a set of contact interactions with zero, two and four derivatives. In addition, one has to take into account various isospin-breaking and relativistic corrections. We employ spectral function regularization for the multi-pion exchanges. Within this framework, it is shown that the three-pion exchange contribution is negligibly small. The low-energy constants (LECs) related to pion-nucleon vertices are taken consistently from studies of pion-nucleon scattering in chiral perturbation theory. The total of 26 four-nucleon LECs has been determined by a combined fit to some np and pp phase shifts from the Nijmegen analysis together with the nn scattering length. The description of nucleon-nucleon scattering and the deuteron observables at (NLO)-L-3 is improved compared to the one at NLO and NNLO. The theoretical uncertainties in observables are estimated based on the variation of the cut-offs in the spectral function representation of the potential and in the regulator utilized in the Lippmann-Schwinger equation. (C) 2004 Elsevier B.V. All rights reserved. C1 Jefferson Lab, Div Theory, Newport News, VA 23606 USA. Ruhr Univ Bochum, Inst Theoret Phys 2, D-44870 Bochum, Germany. Univ Bonn, Helmholtz Inst Strahlen & Kernphys Theorie, D-53115 Bonn, Germany. Forschungszentrum Julich, Inst Kernphys Theorie, D-52425 Julich, Germany. RP Epelbaum, E (reprint author), Jefferson Lab, Div Theory, Newport News, VA 23606 USA. EM epelbaum@jlab.org; waiter.gloeckle@tp2.ruhr-uni-bochum.de; meissner@itkp.uni-bonn.de NR 119 TC 416 Z9 418 U1 1 U2 4 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 JAN 24 PY 2005 VL 747 IS 2-4 BP 362 EP 424 DI 10.1016/j.nuclphysa.2004.09.107 PG 63 WC Physics, Nuclear SC Physics GA 886HR UT WOS:000226218000009 ER PT J AU Kharzeev, D Levin, E Nardi, M AF Kharzeev, D Levin, E Nardi, M TI Color glass condensate at the LHC: hadron multiplicities in pp, pA and AA collisions SO NUCLEAR PHYSICS A LA English DT Article ID CHARGED-PARTICLE MULTIPLICITY; GLUON DISTRIBUTION-FUNCTIONS; NUCLEUS-NUCLEUS COLLISIONS; PLUS AU COLLISIONS; HIGH-DENSITY QCD; HIGH-ENERGY; SMALL-X; RENORMALIZATION-GROUP; TRANSVERSE-MOMENTUM; SEMIHARD PROCESSES AB We make quantitative predictions for the rapidity and centrality dependencies of hadron multiplicities in AA, pA and pp collisions at the LHC energies basing on the ideas of parton saturation in the color glass condensate. (C) 2004 Published by Elsevier B.V. C1 Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. Tel Aviv Univ, Raymond & Beverly Sackler Fac Exact Sci, Sch Phys, HEP Dept, IL-69978 Tel Aviv, Israel. Univ Turin, Dipartimento Fis Teor, I-10125 Turin, Italy. RP Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. EM leving@post.tau.ac.il OI Nardi, Marzia/0000-0003-1574-9869 NR 87 TC 185 Z9 188 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0375-9474 EI 1873-1554 J9 NUCL PHYS A JI Nucl. Phys. A PD JAN 24 PY 2005 VL 747 IS 2-4 BP 609 EP 629 DI 10.1016/j.nuclphysa.2004.10.018 PG 21 WC Physics, Nuclear SC Physics GA 886HR UT WOS:000226218000016 ER PT J AU Davis, CE Ho, CK Hughes, RC Thomas, ML AF Davis, CE Ho, CK Hughes, RC Thomas, ML TI Enhanced detection of m-xylene using a preconcentrator with a chemiresistor sensor SO SENSORS AND ACTUATORS B-CHEMICAL LA English DT Article DE chemiresistor; preconcentrator; m-xylene; limit of detection; environmental monitoring ID ARRAY AB Chemiresistor chemical microsensors are being investigated as a tool for environmental monitoring. These devices can provide real-time in situ chemical concentration data for solvent-contaminated sites of interest. Detection limits of an unaided chemiresistor, however, are typically in the range of 1/1000th of the saturated vapor pressure of a given analyte, which may not be sufficient for chemicals with high vapor pressures and low desired detection limits. Tests were conducted in this study to determine the response of a chemiresistor sensor to in-xylene with and without preconcentration. Results showed that by adding a microfabricated preconcentrator to a chemiresistor sensor, detection limits of m-xylene were decreased by more than two orders of magnitude, from 13.5 ppm to 61.8 ppb, without significantly increasing the complexity of the sensing system. (C) 2004 Elsevier B.V. All rights reserved. C1 Sandia Natl Labs, Dept Microsensor Sci & Technol 1744, Albuquerque, NM 87185 USA. Sandia Natl Labs, Dept Geohydrol 6115, Albuquerque, NM 87185 USA. RP Hughes, RC (reprint author), Sandia Natl Labs, Dept Microsensor Sci & Technol 1744, Albuquerque, NM 87185 USA. EM rchughe@sandia.gov NR 11 TC 37 Z9 37 U1 0 U2 4 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 JAN 24 PY 2005 VL 104 IS 2 BP 207 EP 216 DI 10.1016/j.snb.2004.04.120 PG 10 WC Chemistry, Analytical; Electrochemistry; Instruments & Instrumentation SC Chemistry; Electrochemistry; Instruments & Instrumentation GA 874XP UT WOS:000225384200006 ER PT J AU Zhao, ZB Rek, ZU Yalisove, SM Bilello, JC AF Zhao, ZB Rek, ZU Yalisove, SM Bilello, JC TI Nanostructured chromium nitride films with a valley of residual stress SO THIN SOLID FILMS LA English DT Article DE nanostructures; coatings; residual stress; surface roughness ID SPUTTER-DEPOSITION; TITANIUM NITRIDE; WEAR-RESISTANCE; THIN-FILMS; COATINGS; MICROSTRUCTURE; CRN; EVOLUTION; STATE AB A series of chromium nitride films has been prepared by reactive DC magnetron sputtering onto multiple moving substrates. The films are characterized via an array of experimental techniques, including high-resolution synchrotron radiation X-ray scattering, transmission electron microscope (TEM), atomic force microscope (AFM) and double-crystal diffraction topography (DCDT). Chromium nitride films displays distinct phase structure, stress state and growth morphology, depending on nitrogen flows. The films deposited at very low nitrogen flows show significantly refined microstructures. The macrostructural refinement, accompanied by decreased surface roughness, takes place continuously with increasing nitrogen flow until a nanocrystalline film is obtained. The nanostructured film appears to occur only at the onset of transition from the hexagonal Cr2N to a distorted cubic lattice CrNx. Correspondingly, a deep stress valley (i.e. a sudden reversal of tensile stress to compressive stress) is observed by DCDT. Deposition at higher nitrogen flows leads to the formation of nearly stoichiometric CrN films, with slightly elongated grain structures. The elongated grains also align up crystallographically in a unique direction related to the deposition geometry, indicating the development of tri-axial texture in the CrN films. (C) 2004 Elsevier B.V. All rights reserved. C1 Delphi Corp, Delphi Res Labs, Shelby Township, MI 48315 USA. Stanford Univ, Stanford Synchrotron Radiat Lab, Stanford, CA 94309 USA. Univ Michigan, Dept Mat Sci & Engn, Ann Arbor, MI 48109 USA. RP Zhao, ZB (reprint author), Delphi Corp, Delphi Res Labs, 51786 Shelby Pkwy, Shelby Township, MI 48315 USA. EM zhibo.zhao@delphi.com NR 26 TC 37 Z9 41 U1 0 U2 5 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0040-6090 J9 THIN SOLID FILMS JI Thin Solid Films PD JAN 24 PY 2005 VL 472 IS 1-2 BP 96 EP 104 DI 10.1016/j.tsf.2004.06.116 PG 9 WC Materials Science, Multidisciplinary; Materials Science, Coatings & Films; Physics, Applied; Physics, Condensed Matter SC Materials Science; Physics GA 879WA UT WOS:000225748600017 ER PT J AU Jiang, CS Moutinho, HR Romero, MJ Al-Jassim, MM Xu, YQ Wang, Q AF Jiang, CS Moutinho, HR Romero, MJ Al-Jassim, MM Xu, YQ Wang, Q TI Distribution of the electrical potential in hydrogenated amorphous silicon solar cells SO THIN SOLID FILMS LA English DT Article DE electrical properties and measurements; silicon; solar cells AB We report on a direct measurement of the spatial distribution of electrical potential on cross sections of hydrogenated amorphous silicon (a-Si:H) n-i-p solar cells using scanning Kelvin probe microscopy. We found that most voltage has dropped near the p/i interface up to similar to500 nm into the i-layer, but that the voltage flattens out near the n/i region for a device with i-layer thickness of similar to800 nm. However, the potential distributes approximate-linearly on the entire i-layer for a device with i-layer of similar to250 nm. The potential measurements suggest that the i-layer is slightly n-type (6-13 x 10(15)/cm(3)), and the depletion width is similar to350-500 nm at the i/p interface. This depletion width provides a direct experimental evidence for the device design criteria that a-Si:H solar cells should be thinner than similar to500 nm, in the point view of electrical potential. (C) 2004 Elsevier B.V. All rights reserved. C1 Natl Renewable Energy Lab, Golden, CO 80004 USA. RP Jiang, CS (reprint author), Natl Renewable Energy Lab, 1617 Cole Blvd, Golden, CO 80004 USA. EM chun_sheng_jiang@nrel.gov RI jiang, chun-sheng/F-7839-2012 NR 11 TC 4 Z9 4 U1 1 U2 3 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0040-6090 J9 THIN SOLID FILMS JI Thin Solid Films PD JAN 24 PY 2005 VL 472 IS 1-2 BP 203 EP 207 DI 10.1016/j.tsf.2004.07.049 PG 5 WC Materials Science, Multidisciplinary; Materials Science, Coatings & Films; Physics, Applied; Physics, Condensed Matter SC Materials Science; Physics GA 879WA UT WOS:000225748600031 ER PT J AU Yan, YF Jones, KM Wu, X Al-Jassim, MM AF Yan, YF Jones, KM Wu, X Al-Jassim, MM TI Microstructure of CdTe thin films after mixed nitric and phosphoric acids etching and (HgTe, CuTe)-graphite pasting SO THIN SOLID FILMS LA English DT Article DE CdTe; solar cells; transmisson electron microscopy; interface structure ID CDS/CDTE SOLAR-CELLS; SURFACE PRETREATMENTS; INTERFACE; BEHAVIOR; CONTACTS AB We report on our investigation of the microstructure and composition of the surface of CdTe films after mixed nitric and phosphoric (NP) acids etching, (HgTe, CuTe)-graphite pasting, and thermal annealing. We find that after this process, a thin layer of CdxHg1-xTe forms between the CdTe and Te-rich layers, giving a structure of CdTe/CdxHg1-xTe/Te. High-resolution electron microscopy reveals that the CdxHg1-xTe layer has an epitaxial relationship with the CdTe. Bromine/methanol-etched samples or samples with intentionally deposited Te layers do not form the CdxHg1-xTe layer after (HgTe, CuTe)-graphite pasting and thermal annealing, indicating that they cannot act as fully as the NP etching. (C) 2004 Elsevier B.V All rights reserved. C1 Natl Renewable Energy Lab, Golden, CO 80401 USA. RP Yan, YF (reprint author), Natl Renewable Energy Lab, 1617 Cole Blvd, Golden, CO 80401 USA. EM yanfa_yan@nrel.gov NR 14 TC 10 Z9 11 U1 0 U2 6 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0040-6090 J9 THIN SOLID FILMS JI Thin Solid Films PD JAN 24 PY 2005 VL 472 IS 1-2 BP 291 EP 296 DI 10.1016/j.tsf.2004.07.002 PG 6 WC Materials Science, Multidisciplinary; Materials Science, Coatings & Films; Physics, Applied; Physics, Condensed Matter SC Materials Science; Physics GA 879WA UT WOS:000225748600046 ER PT J AU Babikov, D Kendrick, BK Zhang, P Morokuma, K AF Babikov, D Kendrick, BK Zhang, P Morokuma, K TI Cyclic-N-3. II. Significant geometric phase effects in the vibrational spectra SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID STATE TRANSITION-PROBABILITIES; QUANTUM REACTIVE SCATTERING; POTENTIAL-ENERGY SURFACES; CONICAL INTERSECTION; MOLECULAR-SPECTRA; H+O-2 SCATTERING; WAVE-FUNCTIONS; GROUND-STATE; DYNAMICS; SYSTEMS AB An accurate theoretical prediction of the vibrational spectra for a pure nitrogen ring (cyclic-N-3) molecule is obtained up to the energy of the (2)A(2)/B-2(1) conical intersection. A coupled-channel approach using the hyperspherical coordinates and the recently published ab initio potential energy surface [D. Babikov, P. Zhang, and K. Morokuma, J. Chem. Phys. 121, 6743 (2004)] is employed. Two independent sets of calculations are reported: In the first set, the standard Born-Oppenheimer approximation is used and the geometric phase effects are totally neglected. In the second set, the generalized Born-Oppenhimer approximation is used and the geometric phase effects due to the D-3h conical intersection are accurately treated. All vibrational states are analyzed and assigned in terms of the normal vibration mode quantum numbers. The magnitude of the geometric phase effect is determined for each state. One important finding is an unusually large magnitude of the geometric phase effects in the cyclic-N-3: it is similar to100 cm(-1) for the low-lying vibrational states and exceeds 600 cm(-1) for several upper states. On average, this is almost two orders of magnitude larger than in the previously reported studies. This unique example suggests a favorable path to experimental validation. (C) 2005 American Institute of Physics. C1 Marquette Univ, Dept Chem, Milwaukee, WI 53201 USA. Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Emory Univ, Dept Chem, Atlanta, GA 30322 USA. RP Babikov, D (reprint author), Marquette Univ, Dept Chem, Wehr Chem Bldg, Milwaukee, WI 53201 USA. NR 46 TC 52 Z9 52 U1 0 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 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD JAN 22 PY 2005 VL 122 IS 4 AR 044315 DI 10.1063/1.1824905 PG 20 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 894QP UT WOS:000226807000031 PM 15740256 ER PT J AU Ceotto, M Yang, S Miller, WH AF Ceotto, M Yang, S Miller, WH TI Quantum reaction rate from higher derivatives of the thermal flux-flux autocorrelation function at time zero. SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID TRANSITION-STATE THEORY; PATH-INTEGRAL METHODS; MECHANICAL RATE CONSTANTS; PROTON-TRANSFER REACTIONS; CHEMICAL-REACTION RATES; INSTANTON APPROXIMATION; COLLINEAR REACTIONS; MOLECULAR-DYNAMICS; POLAR ENVIRONMENT; SIMULATIONS AB A quantum theory of thermal reaction rates is presented which maybe viewed as an extension of the recently developed "quantum instanton" (QI) model [W. H. Miller, Y. Zhao, M. Ceotto, and S. Yang, J. Chem. Phys. 119, 1329 (2003)]. It is based on using higher derivatives of the flux-flux autocorrelation function C(t) (as given by Miller, Schwartz, and Tromp) at t=0 to construct a short time approximation for C(t). Tests of this theory on 1 d and collinear reactions, both symmetric and asymmetric, show it to be more accurate than the original QI model, giving rate constants to similar to5% for a wide range of temperature. (C) 2005 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. Lawrence Berkeley Natl Lab, Div Chem Sci, Berkeley, CA 94720 USA. RP Ceotto, M (reprint author), Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. EM miller@cchem.berkeley.edu RI Ceotto, Michele/C-6805-2009 OI Ceotto, Michele/0000-0002-8270-3409 NR 34 TC 14 Z9 14 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 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD JAN 22 PY 2005 VL 122 IS 4 AR 044109 DI 10.1063/1.1839177 PG 7 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 894QP UT WOS:000226807000012 PM 15740237 ER PT J AU Rintelman, JM Adamovic, I Varganov, S Gordon, MS AF Rintelman, JM Adamovic, I Varganov, S Gordon, MS TI Multireference second-order perturbation theory: How size consistent is "almost size consistent" SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID MOLECULAR-ORBITAL METHODS; CONFIGURATION-INTERACTION CALCULATIONS; DIATOMIC DISSOCIATION-ENERGIES; GAUSSIAN-TYPE BASIS; BASIS-SET; ORGANIC-MOLECULES; WAVE-FUNCTIONS; SYSTEMS; STATES; H2O AB A systematic study of the deviation from size consistency of the multireference second-order Moller-Plesset perturbation theory (MRMP2) method is presented. The size-consistency error is shown to depend on the number of monomers in a supermolecule calculation, size of basis set, number of correlated valence electrons, and size of active space. HF, F-2, and N-2 are used as test cases, with stretched bonds, to include simple, well-defined multireference character. This is essential in ensuring that MRMP2 is being tested as a multireference method. It is concluded that the MRMP2 and other multireference perturbation theory methods can exhibit significant size-consistency errors, and that the size of the error depends on the manner in which the perturbation theory is implemented. (C) 2005 American Institute of Physics. C1 Iowa State Univ, Dept Chem, US Dept Energy, Ames, IA 50011 USA. Iowa State Univ, US Dept Energy, Ames Lab, Ames, IA 50011 USA. RP Iowa State Univ, Dept Chem, US Dept Energy, Ames, IA 50011 USA. NR 34 TC 47 Z9 47 U1 1 U2 5 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 JAN 22 PY 2005 VL 122 IS 4 AR 044105 DI 10.1063/1.1817891 PG 7 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 894QP UT WOS:000226807000008 PM 15740233 ER PT J AU Sun, LP Peterson, KA Alexeev, Y Windus, T Kindt, J Hase, WL AF Sun, LP Peterson, KA Alexeev, Y Windus, T Kindt, J Hase, WL TI Effect of the Ar-Ni(s) potential on the cross section for Ar+CH(4)/Ni{111} collision-induced desorption and the need for a more accurate CH(4)/Ni{111} potential SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID VIBRATIONAL-ENERGY FLOW; TRANSITION-STATE THEORY; GAS-SURFACE SCATTERING; COUPLED-CLUSTER METHOD; MOLECULAR-DYNAMICS; CLASSICAL MECHANICS; DISSOCIATION; NI(111); MODEL; CH4 AB In a previous paper [L. Sun, P. de Sainte Claire, O. Meroueh, and W. L Hase, J. Chem. Phys. 114, 535 (2001)], a classical trajectory simulation was reported of CH(4) desorption from Ni{111} by Ar-atom collisions. At an incident angle theta(i) of 60degrees (with respect to the surface normal), the calculated collision-induced desorption (CID) cross sections are in excellent agreement with experiment. However, for smaller incident angles the calculated cross sections are larger than the experimental values and for normal collisions, theta(i) = 0degrees, the calculated cross sections are approximately a factor of 2 larger. This trajectory study used an analytic function for the Ar +Ni(s) intermolecular potential which gives an Ar-Ni{111} potential energy minimum which is an order of magnitude too deep. In the work reported here, the previous trajectory study is repeated with an Ar+Ni(s) analytic intermolecular potential which gives an accurate Ar-Ni{111} potential energy minimum and also has a different surface corrugation than the previous potential. Though there are significant differences between the two Ar+Ni(s) analytic potentials, they have no important effects on the CID dynamics and the cross sections reported here are nearly identical to the previous values. Zero-point energy motions of the surface and the CH(4)-Ni(s) intermolecular modes are considered in the simulation and they are found to have a negligible effect on the CID cross sections. Calculations of the intermolecular potential between CH(4) and a Ni atom, at various levels of theory, suggest that there are substantial approximations in the ab initio calculation used to develop the CH(4)+Ni{111} potential. The implication is that the differences between the trajectory and experimental CID cross sections may arise from an inaccurate CH(4)+Ni{111} potential used in the trajectory simulation. (C) 2005 American Institute of Physics. C1 Northwestern Univ, Dept Chem, Evanston, IL 60208 USA. Washington State Univ, Dept Chem, Pullman, WA 99164 USA. Pacific NW Natl Lab, Environm Mol Sci Lab, Richland, WA 99352 USA. Emory Univ, Dept Chem, Atlanta, GA 30322 USA. Texas Tech Univ, Dept Chem & Biochem, Lubbock, TX 79409 USA. RP Sun, LP (reprint author), Northwestern Univ, Dept Chem, Evanston, IL 60208 USA. NR 38 TC 2 Z9 2 U1 1 U2 2 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD JAN 22 PY 2005 VL 122 IS 4 AR 044704 DI 10.1063/1.1829993 PG 6 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 894QP UT WOS:000226807000055 PM 15740280 ER PT J AU Yamamoto, T Miller, WH AF Yamamoto, T Miller, WH TI Path integral evaluation of the quantum instanton rate constant for proton transfer in a polar solvent SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID TRANSITION-STATE THEORY; THERMAL RATE CONSTANTS; TIME-CORRELATION-FUNCTIONS; BACKWARD SEMICLASSICAL DYNAMICS; MOLECULAR-DYNAMICS; MONTE-CARLO; NONSEPARABLE SYSTEMS; CATALYZED-REACTIONS; CHEMICAL-REACTIONS; ENZYME CATALYSIS AB The quantum instanton approximation for thermal rate constants, a type of quantum transition state theory (QTST), is applied to a model proton transfer reaction in liquid methyl chloride developed by Azzouz and Borgis. Monte Carlo path integral methods are used to carry out the calculations, and two other closely related QTST's, namely, the centroid-density and Hansen-Andersen QTST, are also evaluated for comparison using the present path integral approach. A technique is then introduced that calculates the kinetic isotope effect directly via thermodynamic integration of the rate with respect to hydrogen mass, which has the practical advantage of avoiding costly evaluation of the activation free energy. The present application to the Azzouz-Borgis problem shows that the above three types of QTST provide very similar results for the rate, within 30% of each other, which is nontrivial considering the totally different derivations of these QTSTs; the latter rates are also in reasonable agreement with some other previous results (e.g., obtained via molecular dynamics with quantum transitions), within a factor of similar to2(7) for the H(D) transfer, thus significantly diminishing the possible range of the exact rates. In addition, it is revealed that a small but nonnegligible inconsistency exists in the parametrization of the Azzouz-Borgis model employed in previous studies, which resulted in the large apparent discrepancy in the calculated rates. (C) 2005 American Institute of Physics. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Div Chem Sci, Dept Chem, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Chem Sci, Kenneth S Pitzer Ctr Theoret Chem, Berkeley, CA 94720 USA. RP Yamamoto, T (reprint author), Kyoto Univ, Grad Sch Sci, Dept Chem, Kyoto 6068502, Japan. EM yamamoto@kuchem.kyoto-u.ac.jp; miller@cchem.berkeley.edu NR 56 TC 60 Z9 60 U1 0 U2 5 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD JAN 22 PY 2005 VL 122 IS 4 AR 044106 DI 10.1063/1.1832598 PG 13 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 894QP UT WOS:000226807000009 PM 15740234 ER PT J AU Stapleton, RD Sabree, ZL Palumbo, AV Moyer, CL Devol, AH Roh, Y Zhou, JZ AF Stapleton, RD Sabree, ZL Palumbo, AV Moyer, CL Devol, AH Roh, Y Zhou, JZ TI Metal reduction at cold temperatures by Shewanella isolates from various marine environments SO AQUATIC MICROBIAL ECOLOGY LA English DT Article DE biogeochemistry; geomicrobiology; iron reduction; cobalt reduction; magneite ID DEEP SUBSURFACE ENVIRONMENTS; PSYCHROPHILE STRAIN PA-43; ORGANIC-CARBON OXIDATION; CENTRAL BALTIC SEA; DISSIMILATORY REDUCTION; SP. NOV.; FACULTATIVE ANAEROBE; ENRICHMENT CULTURES; CONTINENTAL-MARGIN; SUBOXIC DIAGENESIS AB Members of the genus Shewanella capable of reducing metals and forming minerals under cold-temperature conditions were isolated from 3 distinct marine habitats (the coast of Washington State, the Puget Sound, and an iron-rich microbial mat off Hawaii). Cultures of microorganisms were isolated at 8degreesC on nutrient agar medium prepared in artificial seawater. Isolates in this study could use a wide variety of electron acceptors such as oxygen, nitrate, and metals, and reduce various metals coupled to the oxidation of several organic acids, glucose or hydrogen at temperatures down to 0degreesC. Akaganeite was reduced to either magnetite or siderite, depending on the test conditions. The geochemical profiles at the sample sites from which these strains were isolated spanned a temperature range of 1.8 to 11degreesC, and all showed active oxygen and nitrate reduction as well as metal reduction. This confirms previous reports that sediment microorganisms participating in biogeochemical cycles remain active at low temperatures. C1 Oak Ridge Natl Lab, Div Environm Sci, Oak Ridge, TN 37831 USA. Western Washington Univ, Dept Biol, Bellingham, WA 98225 USA. Univ Washington, Sch Oceanog, Seattle, WA 98295 USA. RP Palumbo, AV (reprint author), Oak Ridge Natl Lab, Div Environm Sci, Oak Ridge, TN 37831 USA. EM palumboav@ornl.gov RI Palumbo, Anthony/A-4764-2011 OI Palumbo, Anthony/0000-0002-1102-3975 NR 68 TC 21 Z9 21 U1 2 U2 15 PU INTER-RESEARCH PI OLDENDORF LUHE PA NORDBUNTE 23, D-21385 OLDENDORF LUHE, GERMANY SN 0948-3055 J9 AQUAT MICROB ECOL JI Aquat. Microb. Ecol. PD JAN 21 PY 2005 VL 38 IS 1 BP 81 EP 91 DI 10.3354/ame038081 PG 11 WC Ecology; Marine & Freshwater Biology; Microbiology SC Environmental Sciences & Ecology; Marine & Freshwater Biology; Microbiology GA 896QF UT WOS:000226947900008 ER PT J AU Song, JH Kim, F Kim, D Yang, PD AF Song, JH Kim, F Kim, D Yang, PD TI Crystal overgrowth on gold nanorods: Tuning the shape, facet, aspect ratio, and composition of the nanorods SO CHEMISTRY-A EUROPEAN JOURNAL LA English DT Article DE colloids; crystal growth; gold; nanorods; nanostructures ID SEED-MEDIATED GROWTH; CATALYTIC-ACTIVITY; NANOPARTICLES; NANOWIRES; CLUSTERS; SPECTRA AB Electrochemically prepared Au nanorods were used as seeds for the overgrowth of thin shells of gold, silver, and palladium by using a mild reducing agent, ascorbic acid, in the presence of surfactants at ambient condition. The unique crystal facets of the starting nanorods results in anisotropic crystal overgrowth. The overgrowth rates along different crystallographical directions can be further regulated by adding foreign ions or by using different metal reduction methods. overgrowth study provides insights on how different metal ions could be reduced preferentially on different Au nanorod surfaces, so that the composition, aspect ratio, shape, and facet of the resulting nanostructures can be rationally tuned. These surfactant-stabilized bimetallic AU(core)M(shell) (M=Au, Ag, Pd) nanorod colloids might serve as better substrates in surface-enhanced Raman spectroscopy as well as exhibiting enhanced catalytic properties. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Dept Chem, Div Sci Mat, Berkeley, CA 94720 USA. RP Yang, PD (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Dept Chem, Div Sci Mat, Berkeley, CA 94720 USA. EM p_yang@uclink.berkeley.edu OI Kim, Franklin/0000-0002-6548-6588 NR 30 TC 149 Z9 150 U1 16 U2 120 PU WILEY-V C H VERLAG GMBH PI WEINHEIM PA BOSCHSTRASSE 12, D-69469 WEINHEIM, GERMANY SN 0947-6539 EI 1521-3765 J9 CHEM-EUR J JI Chem.-Eur. J. PD JAN 21 PY 2005 VL 11 IS 3 BP 910 EP 916 DI 10.1002/chem.200400805 PG 7 WC Chemistry, Multidisciplinary SC Chemistry GA 893JF UT WOS:000226714400012 PM 15593133 ER PT J AU Patterson, LJ Sturchio, NC Kennedy, BM van Soest, MC Sultan, M Lu, ZT Lehmann, B Purtschert, R El Alfy, Z El Kaliouby, B Dawood, Y Abdallah, A AF Patterson, LJ Sturchio, NC Kennedy, BM van Soest, MC Sultan, M Lu, ZT Lehmann, B Purtschert, R El Alfy, Z El Kaliouby, B Dawood, Y Abdallah, A TI Cosmogenic, radiogenic, and stable isotopic constraints on groundwater residence time in the Nubian Aquifer, Western Desert of Egypt SO GEOCHEMISTRY GEOPHYSICS GEOSYSTEMS LA English DT Article DE chlorine-36; Egypt; groundwater; geochemistry : radiogenic isotope geochemistry; global change : water cycles (1836); hydrology : groundwater hydrology ID GREAT ARTESIAN BASIN; ACCELERATOR MASS-SPECTROMETRY; MILK RIVER AQUIFER; OLD GROUNDWATER; PARIS BASIN; NOBLE-GASES; WATER CIRCULATION; NATURAL TRACERS; CL-36; AUSTRALIA AB [ 1] Measurements of radiochlorine ( (36)Cl), radiogenic noble gases ( (4)He and (40)Ar), and stable chlorine isotope ratios were obtained to assess the residence time of groundwater in the Nubian Aquifer of the Western Desert of Egypt. Measured (36)Cl/ Cl ratios yield apparent residence times from similar to 0.2 to 1.2 x 10(6) years in the deep ( 600 - 1200 m) groundwater ( assuming constant Cl) and less than or equal to 0.16 x 10(6) years in the shallow (< 600 m) groundwater. Values of delta(37) Cl in the groundwater strengthen the application of the (36)Cl dating method by constraining Cl sources and identifying groundwater mixing. Dissolved gases were measured in some of the deep groundwater samples. Measured (4)He concentrations indicate accumulation of radiogenic (4)He that is qualitatively consistent with the age progression indicated by the (36)Cl/ Cl ratios, but the flux of external (4)He from the underlying crust has not been quantified and is not constant throughout the aquifer. Concentrations of (40)Ar range from 3.3 to 6.7 x 10(-4) ccSTP/ g and indicate excess air incorporation at recharge. Measured (40)Ar/(36)Ar ratios do not exceed the atmospheric ratio. A two- dimensional numerical hydrodynamic transect of the aquifer was modeled from the area of the Uweinat Uplift to the northern Bahariya Oasis. Predicted groundwater velocities in the deep portion of the aquifer are 0.5 - 3.5 m/ yr with groundwater residence times up to 9 x 10(5) years; residence times up to 1.3 x 10(6) years are predicted in the confining shale. Aquifer properties are estimated by using the model to fit the measured (36)Cl/ Cl ratios. Under these conditions, hydrodynamic residence times are within about 30% of those calculated from (36)Cl when mixing of Cl(-) is accounted for in the highest- Cl(-) deep groundwaters. By mutually calibrating multiple methods ( hydrodynamic, (36)Cl, and (4)He), a consistent picture of the Nubian Aquifer has emerged in which lateral flow from a southern recharge area dominates the deep horizons, while shallow horizons contain younger, autochthonous recharge. C1 Univ Illinois, Dept Earth & Environm Sci, Chicago, IL 60607 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Earth Sci, Berkeley, CA 94720 USA. Western Michigan Univ, Dept Geosci, Kalamazoo, MI 49008 USA. Argonne Natl Lab, Div Phys, Argonne, IL 60439 USA. Univ Bern, Inst Phys, CH-3012 Bern, Switzerland. Egyptian Geol Survey & Min Author, Cairo, Egypt. Ain Shams Univ, Dept Geol, Cairo, Egypt. RP Patterson, LJ (reprint author), Univ Illinois, Dept Earth & Environm Sci, 845 W Taylor St,MC 186, Chicago, IL 60607 USA. EM sturchio@uic.edu RI dawood, Yehia/J-2599-2012; Abd-Allah, Ali/D-5559-2013; Purtschert, Roland/N-7108-2016 OI Abd-Allah, Ali/0000-0001-5597-4943; Purtschert, Roland/0000-0002-4734-7664 NR 62 TC 15 Z9 15 U1 2 U2 11 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 1525-2027 J9 GEOCHEM GEOPHY GEOSY JI Geochem. Geophys. Geosyst. PD JAN 21 PY 2005 VL 6 AR Q01005 DI 10.1029/2004GC000779 PG 19 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 891JS UT WOS:000226577800001 ER PT J AU Zaveri, RA Easter, RC Wexler, AS AF Zaveri, RA Easter, RC Wexler, AS TI A new method for multicomponent activity coefficients of electrolytes in aqueous atmospheric aerosols SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID SULFURIC-ACID; THERMODYNAMIC MODEL; EQUILIBRIUM-MODEL; SULFATE; AMMONIUM; SYSTEMS; NITRATE AB [1] Three- dimensional models of atmospheric inorganic aerosols need accurate and computationally efficient parameterizations of activity coefficients of various electrolytes in multicomponent aqueous solutions. In this paper, we extend the Taylor's series expansion mixing rule used by C. Wagner in 1952 for estimating activity coefficients in dilute alloy solutions to aqueous electrolyte solutions at any concentration. The resulting method, called the multicomponent Taylor expansion method ( MTEM), estimates the mean activity coefficient of an electrolyte in a multicomponent solution on the basis of its values in binary solutions of all the electrolytes present in the mixture at the solution water activity a(w), assuming a(w) is equal to the ambient relative humidity. MTEM is applied here for atmospheric aerosol systems containing H+, NH4 (+), Na+, Ca2+, SO42 -, HSO4-, NO3-, and Cl- ions. The aerosol water content is calculated using the Zdanovskii- Stokes- Robinson ( ZSR) method. For self- consistency, most of the MTEM and ZSR parameters are derived using the comprehensive Pitzer- Simonson- Clegg model at 298.15 K and are valid for an a(w) range of 0.2 - 0.97. Because CaSO4 is sparingly soluble, it is treated as a solid in the model over the entire a(w) range. MTEM is evaluated for several multicomponent systems representing various continental and marine aerosols and is contrasted against the mixing rule of C. L. Kusik and H. P. Meissner and of L. A. Bromley and the newer approach of S. Metzger and colleagues. Predictions of MTEM are found to be generally within a factor of 0.8 - 1.25 of the comprehensive Pitzer- Simonson- Clegg model and are shown to be significantly more accurate than predictions of the other three methods. MTEM also yields a noniterative solution of the bisulfate ion dissociation in sulfate- rich systems: a major computational advantage over other ionic- strength- based methods that require an iterative solution. CPU time requirements of MTEM relative to other methods for sulfate- poor and sulfate- rich systems are also discussed. C1 Pacific NW Natl Lab, Atmospher Sci & Global Change Div, Richland, WA 99352 USA. Univ Calif Davis, Dept Mech & Aeronaut Engn, Davis, CA 95616 USA. Univ Calif Davis, Dept Civil & Environm Engn, Davis, CA 95616 USA. Univ Calif Davis, Dept Land Air & Water Resources, Davis, CA 95616 USA. RP Zaveri, RA (reprint author), Pacific NW Natl Lab, Atmospher Sci & Global Change Div, MSIN K9-30,POB 999, Richland, WA 99352 USA. EM rahul.zaveri@pnl.gov; richard.easter@pnl.gov; aswexler@ucdavis.edu OI Zaveri, Rahul/0000-0001-9874-8807 NR 31 TC 64 Z9 66 U1 3 U2 17 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD JAN 21 PY 2005 VL 110 IS D2 AR D02201 DI 10.1029/2004JD004681 PG 23 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 891KG UT WOS:000226579200002 ER PT J AU Westermann, S Avila-Sakar, A Wang, HW Niederstrasser, H Wong, J Drubin, DG Nogales, E Barnes, G AF Westermann, S Avila-Sakar, A Wang, HW Niederstrasser, H Wong, J Drubin, DG Nogales, E Barnes, G TI Formation of a dynamic kinetochore-microtubule interface through assembly of the Dam1 ring complex SO MOLECULAR CELL LA English DT Article ID BUDDING YEAST KINETOCHORE; MITOTIC SPINDLE; SACCHAROMYCES-CEREVISIAE; DUO1P/DAM1P COMPLEX; CENTROMERE; IDENTIFICATION; ATTACHMENT; MECHANISM; METAPHASE; INTEGRITY AB How kinetochore proteins form a dynamic interface with microtubules is largely unknown. In budding yeast, the 10-protein Dam1 complex is an Aurora kinase target that plays essential roles maintaining the integrity of the mitotic spindle and regulating interactions with the kinetochore. Here, we investigated the biochemical properties of purified Dam1 complex. The complex oligomerized into rings around microtubules. Ring formation was facilitated by microtubules but could occur in their absence. Mutant alleles led to partially assembled complexes or reduced microtubule binding. The interaction between rings and microtubules is mediated by the C termini of both Dam1 and up-tubulin. Ring formation promotes microtubule assembly, stabilizes against disassembly, and promotes bundling. A GTP-tubulin lattice is the preferred binding partner for the complex, and Dam1 rings can exhibit lateral mobility on microtubules. These observations suggest a mechanism by which the kinetochore can recognize and stay attached to the plus ends of microtubules. C1 Univ Calif Berkeley, Dept Mol & Cell Biol, Berkeley, CA 94720 USA. Univ Calif Berkeley, Howard Hughes Med Inst, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Barnes, G (reprint author), Univ Calif Berkeley, Dept Mol & Cell Biol, Berkeley, CA 94720 USA. EM gbarnes@socrates.berkeley.edu FU NIGMS NIH HHS [GM51487-09, GM47842] NR 35 TC 183 Z9 199 U1 1 U2 11 PU CELL PRESS PI CAMBRIDGE PA 1100 MASSACHUSETTS AVE, CAMBRIDGE, MA 02138 USA SN 1097-2765 J9 MOL CELL JI Mol. Cell PD JAN 21 PY 2005 VL 17 IS 2 BP 277 EP 290 DI 10.1016/j.molcel.2004.12.019 PG 14 WC Biochemistry & Molecular Biology; Cell Biology SC Biochemistry & Molecular Biology; Cell Biology GA 891QR UT WOS:000226596100014 PM 15664196 ER PT J AU Klassen, NV Shmurak, SZ Shmyt'ko, IM Strukova, GK Derenzo, SE Weber, MJ AF Klassen, NV Shmurak, SZ Shmyt'ko, IM Strukova, GK Derenzo, SE Weber, MJ TI Structure and luminescence spectra of lutetium and yttrium borates synthesized from ammonium nitrate melt SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 7th International Conference on Inorganic Scintillators and Industrial Applications CY SEP 08-12, 2003 CL Polytechnic Univ Valencia, Valencia, ITALY HO Polytechnic Univ Valencia DE scintillation detectors; powder processing; chemical synthesis; photoluminescence AB Lutetium and yttriurn borates doped with europium, terbium, gadolinium, etc. have been synthesized by dissolving initial oxides and nitrates in ammonium nitrate melt and thermal decomposition of the solvent. Annealings in the range of 500-1100degreesC modified the dimensions of the grains from 2 to 3 nm to more than 100 nm. Significant dependence of the structure of lutetium borate on slight doping with rare earth ions has been found: terbium makes high-temperature vaterite phase preferential at room temperature, whereas europium stabilizes low-temperature calcite phase. Influence of the structure of the borates on the pattern of the luminescence spectra of europium dopant was observed. Possibilities for manufacturing of scintillating lutetium borate ceramics by means of this method of synthesis are discussed. (C) 2004 Elsevier B.V. All rights reserved. C1 Russian Acad Sci, Inst Solid State Phys, Chernogolovka 142432, Russia. Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. RP Klassen, NV (reprint author), Russian Acad Sci, Inst Solid State Phys, Chernogolovka 142432, Russia. EM klassen@issp.ac.ru NR 7 TC 17 Z9 17 U1 1 U2 5 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD JAN 21 PY 2005 VL 537 IS 1-2 BP 144 EP 148 DI 10.1016/j.nima.2004.07.254 PG 5 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 893RP UT WOS:000226737200030 ER PT J AU Shmurak, SZ Strukova, GK Smyt'ko, IM Klassen, NV Kobelev, NP Derenzo, SE Weber, MJ AF Shmurak, SZ Strukova, GK Smyt'ko, IM Klassen, NV Kobelev, NP Derenzo, SE Weber, MJ TI Studies of nanocrystalline rare earth gallate and aluminate scintillators prepared by a new method SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 7th International Conference on Inorganic Scintillators and Industrial Applications CY SEP 08-12, 2003 CL Polytechnic Univ Valencia, Valencia, ITALY HO Polytechnic Univ Valencia DE scintillation detectors; powder processing; chemical synthesis; photoluminescence AB Powdered gallates and aluminates of rare earth metals doped with rare earth activators of scintillations have been synthesized by a new method based on dissolving of initial oxides or nitrates in ammonium nitrate me] (at about 200degreesC). Subsequent annealings in the range from 500degreesC to about 1000degreesC resulted in gradual modifications of the dimensions of the grains in nanoscopic range from 2 to 3 nm to more than 100 nm. The studies of the spectra of photo-and X-ray luminescence showed that the structure of radiative electron transitions was modified in parallel with variations of the grain sizes of the materials. Essential increase of the light emission by optimal nanocrystalline structure was obtained. (C) 2004 Elsevier B.V. All rights reserved. C1 Russian Acad Sci, Inst Solid State Phys, Chernogolovka 142432, Russia. Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. RP Klassen, NV (reprint author), Russian Acad Sci, Inst Solid State Phys, Chernogolovka 142432, Russia. EM klassen@issp.ac.ru NR 4 TC 12 Z9 12 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 JAN 21 PY 2005 VL 537 IS 1-2 BP 149 EP 153 DI 10.1016/j.nima.2004.07.055 PG 5 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 893RP UT WOS:000226737200031 ER PT J AU Kurlov, VN Klassen, NV Dodonov, AM Shmurak, SZ Strukova, GK Shmyt'ko, IM Derenzo, SE Weber, MJ AF Kurlov, VN Klassen, NV Dodonov, AM Shmurak, SZ Strukova, GK Shmyt'ko, IM Derenzo, SE Weber, MJ TI Growth of YAG : Re3+ (Re=Ce, Eu)-shaped crystals by the EFG/Stepanov technique SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 7th International Conference on Inorganic Scintillators and Industrial Applications CY SEP 08-12, 2003 CL Polytechnic Univ Valencia, Valencia, ITALY HO Polytechnic Univ Valencia DE EFG/Stepanov method; shaped crystal growth; YAG single crystals; scintillators ID PHOSPHOR AB YAG:Re3+ (Re3+ = Ce, Eu)-shaped crystals were grown by the EFG/Stepanov technique. The method is useful for the economics of single crystals of high value materials, in decreasing the waste of materials. and to make possible the production of complex-shaped crystals. Luminescence of the YAG:RE fibers is investigated. (C) 2004 Published by Elsevier B.V. C1 Russian Acad Sci, Inst Solid State Phys, Chernogolovka 142432, Moscow Region, Russia. Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. RP Kurlov, VN (reprint author), Russian Acad Sci, Inst Solid State Phys, Chernogolovka 142432, Moscow Region, Russia. EM kurlov@issp.ac.ru NR 8 TC 7 Z9 7 U1 2 U2 5 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD JAN 21 PY 2005 VL 537 IS 1-2 BP 197 EP 199 DI 10.1016/j.nima.2004.08.007 PG 3 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 893RP UT WOS:000226737200042 ER PT J AU Derenzo, SE Bourret-Courchesne, E Weber, M Klintenberg, MK AF Derenzo, SE Bourret-Courchesne, E Weber, M Klintenberg, MK TI Scintillation studies of CdS(In): effects of various semiconductor doping strategies SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 7th International Conference on Inorganic Scintillators and Industrial Applications CY SEP 08-12, 2003 CL Polytechnic Univ Valencia, Valencia, ITALY HO Polytechnic Univ Valencia DE cadmium sulfide; scintillation mechanisms; radiative recombination; doping II-VI semiconductors ID FLUORESCENT LIFETIME MEASUREMENTS; CADMIUM-SULFIDE; OPTICAL-PROPERTIES; CDS-IN; ZNO; LUMINESCENCE; EMISSION AB We present room-temperature photoluminescence and pulsed X-ray measurements of powder samples of CdS(In) codoped with three hole traps (Te, Ag, and Na). Te is an isoelectronic hole trap and Ag, and Na are acceptor hole traps. The emission of CdS(In) excited at 430 nm is centered at approximate to 520 nm (near the band edge) with approximate to 20 nm FWHM. The emissions from CdS(Te) and the three codoped samples are shifted to longer wavelengths and are characterized by broad emission bands peaking near 630 nm. Whereas the decay of the CdS(Te) emission is nonexponential with times > 10 its, the decay of CdS(In, Te) is 3.3 ns and exponential over three decades. The decay of the acceptor-doped samples CdS(In,Ag) and CdS(In, Na) are also fast, 2.5 and 2.8 ns, respectively. These results show the potential for developing fast inorganic scintillators based on direct-gap semiconductors that can be codoped to provide fast radiative recombination. Additional work is needed to increase the luminosity. (C) 2004 Elsevier B.V. All rights reserved. C1 Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. Uppsala Univ, Dept Phys, Uppsala, Sweden. RP Derenzo, SE (reprint author), Univ Calif Berkeley, Lawrence Berkeley Natl Lab, 1 Cyclotron Rd,Mail Stop 55-121, Berkeley, CA 94720 USA. EM sederenzo@lbl.gov NR 15 TC 9 Z9 9 U1 0 U2 13 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 JAN 21 PY 2005 VL 537 IS 1-2 BP 261 EP 265 DI 10.1016/j.nima.2004.08.022 PG 5 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 893RP UT WOS:000226737200057 ER PT J AU Shiran, N Gektin, A Neicheva, S Weber, M Derenzo, S Kirm, M True, M Shpinkov, I Spassky, D Shimamura, K Ichinose, N AF Shiran, N Gektin, A Neicheva, S Weber, M Derenzo, S Kirm, M True, M Shpinkov, I Spassky, D Shimamura, K Ichinose, N TI Energy transfer in pure and Ce-doped LiCaAlF6 and LiSrAlF6 crystals SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 7th International Conference on Inorganic Scintillators and Industrial Applications CY SEP 08-12, 2003 CL Polytechnic Univ Valencia, Valencia, ITALY HO Polytechnic Univ Valencia DE Ce-doped LiCaAlF6 and LiSrAlF6; ultra-fast rise time; decay time; scintillation; thermoluminescence ID LUMINESCENCE AB Intrinsic ultra-fast scintillations at pulsed X-ray excitation were found in LiCaAlF6 and LiSrAlF6. Radiative recombination features of Ce-doped crystals are explained by differences of lattice properties, defect structure and Ce3+ ion environment in these crystals. The role of exciton formation, electron and hole traps, and energy transfer to the activator centers are discussed. (C) 2004 Elsevier B.V. All rights reserved. C1 Inst Scintillat Mat, UA-61001 Kharkov, Ukraine. Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. Univ Hamburg, Inst Phys Expt, D-22761 Hamburg, Germany. Moscow MV Lomonosov State Univ, Dept Phys, Moscow 119899, Russia. Waseda Univ, Kagami Mem Lab Mat Sci & Tecn, Tokyo 1690051, Japan. RP Shiran, N (reprint author), Inst Scintillat Mat, 60 Lenin Ave, UA-61001 Kharkov, Ukraine. EM shiran@isc.kharkov.com RI Spassky, Dmitry/D-9524-2012; Kirm, Marco/M-1533-2016 OI Kirm, Marco/0000-0002-1833-6894 NR 10 TC 11 Z9 11 U1 0 U2 4 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD JAN 21 PY 2005 VL 537 IS 1-2 BP 266 EP 270 DI 10.1016/j.nima.2004.08.023 PG 5 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 893RP UT WOS:000226737200058 ER PT J AU Moses, WW Shah, KS AF Moses, WW Shah, KS TI Potential for RbGd2Br7 : Ce, LaBr3 : Ce, LaBr3 : Ce, and LuI3 : Ce in nuclear medical imaging SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 7th International Conference on Inorganic Scintillators and Industrial Applications CY SEP 08-12, 2003 CL Polytechnic Univ Valencia, Valencia, ITALY HO Polytechnic Univ Valencia DE scintillator; nuclear medical imaging; PET; SPECT; RbGd2Br7 : LaCl3 : LaBr3 : Lul(3) ID ENERGY-RESOLUTION SCINTILLATOR; GAMMA-RAY AB Several new scintillators (RbGd2Br7:Ce, LaCl3:Ce, LaBr3:Ce, and LuI3:Ce) have excellent energy resolution, high light output, short decay time, and moderate density and effective atomic number, making them attractive for nuclear medical imaging. We analyze how well these four materials meet the requirements for SPECT and PET. Because of their high light output and excellent energy resolution, LaBr3:Ce and LaCl3:Ce have the potential to replace NaI:Tl as the material of choice for SPECT. The light output and energy resolution make LaBr3:Ce and LuI3:Ce the most promising of these scintillators for PET, but their relatively low density and photoelectric fraction make them less attractive than BGO and LSO. (C) 2001 Elsevier Science. All rights reserved (C) 2004 Elsevier B.V. All rights reserved. C1 Lawrence Berkeley Lab, Berkeley, CA 94720 USA. Radiat Monitoring Devices Inc, Watertown, MA 02472 USA. RP Moses, WW (reprint author), Lawrence Berkeley Lab, 1 Cyclotron Rd,Mail Stop 55-221, Berkeley, CA 94720 USA. EM wwmoses@lbl.gov NR 12 TC 34 Z9 38 U1 0 U2 5 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD JAN 21 PY 2005 VL 537 IS 1-2 BP 317 EP 320 DI 10.1016/j.nima.2004.08.034 PG 4 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 893RP UT WOS:000226737200069 ER PT J AU Ryzhikov, VD Opolonin, AD Pashko, PV Svishch, VM Volkov, VG Lysetskaya, EK Kozin, DN Smith, C AF Ryzhikov, VD Opolonin, AD Pashko, PV Svishch, VM Volkov, VG Lysetskaya, EK Kozin, DN Smith, C TI Instruments and detectors on the base of scintillator crystals ZnSe(Te), CWO, CsI(Tl) for systems of security and customs inspection systems SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 7th International Conference on Inorganic Scintillators and Industrial Applications CY SEP 08-12, 2003 CL Polytechnic Univ Valencia, Valencia, ITALY HO Polytechnic Univ Valencia DE multi-energy radiography; two-energy detection method; X-ray digital radiography AB Results of experimental studies of detector arrays scintillator-photodiode (S-PD) and scintillator-photoreceiving device (S-PRD) used for X-ray digital radiography have shown that there exist further possibilities to increase spatial resolution of this system up to 2-3 line pairs per mm. Theoretical analysis and experimental studies show that the two-energy detection method not only allows one to detect organics on the background of metal, but also substantially increases (by 3-5 times) the detection ability of the system as a whole, especially if parameters of the S-PD pair are optimized, in particular, when ZnSe(Te) is used in the low-energy circuit. A possibility to distinguish, in principle, between substances with insignificant differences in atomic number has been theoretically proven-by transition to multi-energy radiography. 3D-imaging has been realized using S-PD detector arrays. On base of theoretical and experimental search was installation of several types of inspection systems for control objects with square size 0.4 x 0.6-2.5 x 3.5 m. (C) 2004 Elsevier B.V. All rights reserved. C1 Inst Single Crystals, STC Radiat Instruments Concern, UA-61001 Kharkov, Ukraine. State Customs Serv Ukraine, Kiev, Ukraine. SCB Polisvit PC Kommunar, Kharkov, Ukraine. Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. RP Ryzhikov, VD (reprint author), Inst Single Crystals, STC Radiat Instruments Concern, 60 Lenin Ave, UA-61001 Kharkov, Ukraine. EM stcri@isc.kharkov.com NR 8 TC 10 Z9 11 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 JAN 21 PY 2005 VL 537 IS 1-2 BP 424 EP 430 DI 10.1016/j.nima.2004.08.056 PG 7 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 893RP UT WOS:000226737200091 ER PT J AU Naydenov, SV Ryzhikov, VD Smith, CF AF Naydenov, SV Ryzhikov, VD Smith, CF TI Multi-energy approach in radiography and introscopy SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 7th International Conference on Inorganic Scintillators and Industrial Applications CY SEP 08-12, 2003 CL Polytechnic Univ Valencia, Valencia, ITALY HO Polytechnic Univ Valencia DE applications of scintillation detectors; multi-energy radiography; non-destructive testing; X-ray introscopy; remote control ID DIGITAL RADIOGRAPHY; DETECTOR AB Prospects of the multi-energy approach are considered for radiography and introsopy using scintillation detectors for detection of penetrating radiation. Three main physical methods using the multi-energeticity principle are compared: the method of basic materials (synthesis), radiographic spectrometry (decomposition), and radiographic spectroscopy (analysis) of materials. A new algorithm has been developed for direct quantitative reconstruction of the effective atomic number. A universal law has been predicted relating the effective atomic number and relative radiographic reflex of the two-energy radiography. This law is confirmed by experimental data on radiation absorption in simple materials at low, medium and high energies. It has been proved that the accuracy of the new method can be by an order of magnitude higher than with the existing procedures, reaching 90-95%. The proposed developments can find applications in industrial non-destructive testing, nuclear monitoring, materials science, detection of explosives, etc. (C) 2004 Published by Elsevier B.V. C1 Natl Acad Sci Ukraine, Inst Single Crystals, UA-61001 Kharkov, Ukraine. Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Naydenov, SV (reprint author), Natl Acad Sci Ukraine, Inst Single Crystals, 60 Lenin Ave, UA-61001 Kharkov, Ukraine. EM naydenov@isc.kharkov.com OI Naydenov, Sergei/0000-0002-5585-763X NR 5 TC 5 Z9 5 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD JAN 21 PY 2005 VL 537 IS 1-2 BP 462 EP 466 DI 10.1016/j.nima.2004.08.065 PG 5 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 893RP UT WOS:000226737200100 ER PT J AU Arslan, I Bleloch, A Stach, EA Browning, ND AF Arslan, I Bleloch, A Stach, EA Browning, ND TI Atomic and electronic structure of mixed and partial dislocations in GaN SO PHYSICAL REVIEW LETTERS LA English DT Article ID LIGHT-EMITTING-DIODES; CLOSE-PACKED METALS; THREADING DISLOCATIONS; SCREW DISLOCATIONS; STACKING-FAULT; MICROSCOPY; FILMS; EPITAXY; EDGE AB Here we present a detailed study of mixed dislocations in GaN, in which the complexities of the atomic arrangement in the cores have been imaged directly for the first time using an aberration corrected scanning transmission electron microscope. In addition to being present as a full-core structure, the mixed dislocation is observed to dissociate into partial dislocations separated by a stacking fault only a few unit cells in length. The generation of this stacking fault appears to be impurity driven and its presence is consistent with theoretical predictions for dislocation dissociation in materials with hexagonal crystal symmetry. C1 Univ Cambridge, Dept Mat Sci & Met, Cambridge CB2 3QZ, England. SERC, Daresbury Lab, UK SuperSTEM, Warrington WA4 4AD, Cheshire, England. Univ Calif Berkeley, Lawrence Berkeley Lab, Natl Ctr Electron Microscopy, Berkeley, CA 94720 USA. Purdue Univ, Sch Mat Engn, W Lafayette, IN 47907 USA. Univ Calif Davis, Dept Chem Engn & Mat Sci, Davis, CA 95616 USA. RP Univ Cambridge, Dept Mat Sci & Met, Pembroke St, Cambridge CB2 3QZ, England. RI Bleloch, Andrew/A-1350-2009; Stach, Eric/D-8545-2011; OI Stach, Eric/0000-0002-3366-2153; Browning, Nigel/0000-0003-0491-251X NR 30 TC 36 Z9 36 U1 2 U2 31 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 EI 1079-7114 J9 PHYS REV LETT JI Phys. Rev. Lett. PD JAN 21 PY 2005 VL 94 IS 2 AR 025504 DI 10.1103/PhysRevLett.94.025504 PG 4 WC Physics, Multidisciplinary SC Physics GA 889YN UT WOS:000226478900042 PM 15698191 ER PT J AU Audebert, P Renaudin, P Bastiani-Ceccotti, S Geindre, JP Chenais-Popovics, C Tzortzakis, S Nagels-Silvert, V Shepherd, R Matsushima, I Gary, S Girard, F Peyrusse, O Gauthier, JC AF Audebert, P Renaudin, P Bastiani-Ceccotti, S Geindre, JP Chenais-Popovics, C Tzortzakis, S Nagels-Silvert, V Shepherd, R Matsushima, I Gary, S Girard, F Peyrusse, O Gauthier, JC TI Picosecond time-resolved x-ray absorption spectroscopy of ultrafast aluminum plasmas SO PHYSICAL REVIEW LETTERS LA English DT Article ID SUBPICOSECOND LASER; IONIZATION; SIMULATION; DYNAMICS AB We have used point-projection K-shell absorption spectroscopy to infer the ionization and recombination dynamics of transient aluminum plasmas. Two femtosecond beams of the 100 TW laser at the LULI facility were used to produce an aluminum plasma on a thin aluminum foil (83 or 50 nm), and a picosecond x-ray backlighter source. The short-pulse backlighter probed the aluminum plasma at different times by adjusting the delay between the two femtosecond driving beams. Absorption x-ray spectra at early times are characteristic of a dense and rather homogeneous plasma. Collisional-radiative atomic physics coupled with hydrodynamic simulations reproduce fairly well the measured average ionization as a function of time. C1 Univ Paris 06, Ecole Polytech, CEA CNRS UMR 7605, Lab Utilisat Lasers Intenses, F-91128 Palaiseau, France. CEA, F-91680 Bruyeres Le Chatel, France. Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. Natl Inst Adv Ind Sci & Technol, Tsukuba, Ibaraki 3058568, Japan. Univ Bordeaux 1, CEA, CNRS UMR 5107, Ctr Lasers Intenses & Applicat, F-33405 Talence, France. RP Audebert, P (reprint author), Univ Paris 06, Ecole Polytech, CEA CNRS UMR 7605, Lab Utilisat Lasers Intenses, F-91128 Palaiseau, France. RI Isao, Matsushima/A-2365-2013; Tzortzakis, Stelios/J-5559-2013 OI Tzortzakis, Stelios/0000-0001-9242-4182 NR 21 TC 66 Z9 68 U1 1 U2 3 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD JAN 21 PY 2005 VL 94 IS 2 AR 025004 DI 10.1103/PhysRevLett.94.025004 PG 4 WC Physics, Multidisciplinary SC Physics GA 889YN UT WOS:000226478900035 PM 15698184 ER PT J AU Brodsky, SJ Carlson, CE Hiller, JR Hwang, DS AF Brodsky, SJ Carlson, CE Hiller, JR Hwang, DS TI Constraints on proton structure from precision atomic-physics measurements SO PHYSICAL REVIEW LETTERS LA English DT Article ID HYDROGEN HYPERFINE STRUCTURE; POLARIZABILITY CONTRIBUTION; SCATTERING; RADIUS; SHIFT AB Ground-state hyperfine splittings in hydrogen and muonium are very well measured. Their difference, after correcting for magnetic moment and reduced mass effects, is due solely to proton structure-the large QED contributions for a pointlike nucleus essentially cancel. The rescaled hyperfine difference depends on the Zemach radius, a fundamental measure of the proton, computed as an integral over a product of electric and magnetic proton form factors. The determination of the Zemach radius, (1.019+/-0.016) fm, from atomic physics tightly constrains fits to accelerator measurements of proton form factors. Conversely, we can use muonium data to extract an experimental value for QED corrections to hydrogenic hyperfine data. There is a significant discrepancy between measurement and theory, in the same direction as a corresponding discrepancy in positronium. C1 Stanford Univ, Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. Coll William & Mary, Dept Phys, Particle Theory Grp, Williamsburg, VA 23187 USA. Univ Minnesota, Dept Phys, Duluth, MN 55812 USA. Sejong Univ, Dept Phys, Seoul 143747, South Korea. RP Stanford Univ, Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. EM sjbth@slac.stanford.edu; carlson@physics.wm.edu; jhiller@d.umn.edu; dshwang@sejong.ac.kr NR 40 TC 19 Z9 19 U1 1 U2 3 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 EI 1079-7114 J9 PHYS REV LETT JI Phys. Rev. Lett. PD JAN 21 PY 2005 VL 94 IS 2 AR 022001 DI 10.1103/PhysRevLett.94.022001 PG 4 WC Physics, Multidisciplinary SC Physics GA 889YN UT WOS:000226478900015 PM 15698164 ER PT J AU Cai, YQ Mao, HK Chow, PC Tse, JS Ma, Y Patchkovskii, S Shu, JF Struzhkin, V Hemley, RJ Ishii, H Chen, CC Jarrige, I Chen, CT Shieh, SR Huang, EP Kao, CC AF Cai, YQ Mao, HK Chow, PC Tse, JS Ma, Y Patchkovskii, S Shu, JF Struzhkin, V Hemley, RJ Ishii, H Chen, CC Jarrige, I Chen, CT Shieh, SR Huang, EP Kao, CC TI Ordering of hydrogen bonds in high-pressure low-temperature H2O SO PHYSICAL REVIEW LETTERS LA English DT Article ID RAY RAMAN-SCATTERING; ABSORPTION SPECTRA; LIQUID WATER; ICE; PHASE; TRANSITION; PERFORMANCE; MBAR AB The near K-edge structure of oxygen in liquid water and ices III, II, and IX at 0.25 GPa and several low temperatures down to 4 K has been studied using inelastic x-ray scattering at 9884.7 eV with a total energy resolution of 305 and 175 meV. A marked decrease of the preedge intensity from the liquid phase and ice III to ices II and IX is attributed to ordering of the hydrogen bonds in the proton-ordered lattice of the latter phases. Density functional theory calculations including the influence of the Madelung potential of the ice IX crystal correctly account for the remaining preedge feature. Furthermore, we obtain spectroscopic evidence suggesting a possible new phase of ice at temperatures between 4 and 50 K. C1 Natl Synchrotron Radiat Res Ctr, Hsinchu 30077, Taiwan. Carnegie Inst Sci, Geophys Lab, Washington, DC 20015 USA. Natl Res Council Canada, Steacie Inst Mol Sci, Ottawa, ON K1A 0R6, Canada. Natl Cheng Kung Univ, Tainan 701, Taiwan. Brookhaven Natl Lab, Natl Synchrotron Light Source, Upton, NY 11937 USA. RP Natl Synchrotron Radiat Res Ctr, Hsinchu 30077, Taiwan. EM cai@nsrrc.org.tw RI Ma, Yanming/A-7297-2008; Ma, Yanming/A-4982-2009; Cai, Yong/C-5036-2008; Struzhkin, Viktor/J-9847-2013; Jarrige, Ignace/M-6371-2016 OI Ma, Yanming/0000-0003-3711-0011; Cai, Yong/0000-0002-9957-6426; Struzhkin, Viktor/0000-0002-3468-0548; Jarrige, Ignace/0000-0002-1043-5695 NR 27 TC 60 Z9 61 U1 2 U2 23 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 EI 1079-7114 J9 PHYS REV LETT JI Phys. Rev. Lett. PD JAN 21 PY 2005 VL 94 IS 2 AR 025502 DI 10.1103/PhysRevLett.94.025502 PG 4 WC Physics, Multidisciplinary SC Physics GA 889YN UT WOS:000226478900040 PM 15698189 ER PT J AU Chartier, A Meis, C Crocombette, JP Weber, WJ Corrales, LR AF Chartier, A Meis, C Crocombette, JP Weber, WJ Corrales, LR TI Molecular dynamic simulation of disorder induced amorphization in pyrochlore SO PHYSICAL REVIEW LETTERS LA English DT Article ID RADIATION-INDUCED AMORPHIZATION; ORDER-DISORDER; WASTE FORM; TRANSITION; PLUTONIUM; DAMAGE; ION AB The defect accumulation mechanism of amorphization has been studied for the La2Zr2O7 pyrochlore by means of classical molecular dynamic simulations. Present calculations show that the accumulation of cation Frenkel pairs is the main driving parameter for the amorphization process, while the oxygen atoms simply rearrange around cations. Under Frenkel pair accumulation, the structure follows the pyrochlore-fluorite-amorphous sequence. Present results consequently provide atomic-level interpretation to previous experimental irradiation observations of the two-step phase transition. C1 CEA Saclay, DEN, DPC, SCP, F-91191 Gif Sur Yvette, France. INSTN Saclay, UEPEM, F-91191 Gif Sur Yvette, France. CEA Saclay, DEN, DMN, SRMP, F-91991 Gif Sur Yvette, France. Pacific NW Natl Lab, Richland, WA 99352 USA. RP Chartier, A (reprint author), CEA Saclay, DEN, DPC, SCP, Batiment 450 Sud, F-91191 Gif Sur Yvette, France. EM achartier@CARNAC.CEA.FR RI Weber, William/A-4177-2008; Crocombette, Jean-Paul/E-7681-2012 OI Weber, William/0000-0002-9017-7365; Crocombette, Jean-Paul/0000-0001-9543-3973 NR 19 TC 42 Z9 42 U1 3 U2 27 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 JAN 21 PY 2005 VL 94 IS 2 AR 025505 DI 10.1103/PhysRevLett.94.025505 PG 4 WC Physics, Multidisciplinary SC Physics GA 889YN UT WOS:000226478900043 PM 15698192 ER PT J AU Leng, YS Cummings, PT AF Leng, YS Cummings, PT TI Fluidity of hydration layers nanoconfined between mica surfaces SO PHYSICAL REVIEW LETTERS LA English DT Article ID MOLECULARLY THIN-LAYERS; SIMPLE LIQUIDS; DYNAMICAL PROPERTIES; PHASE-TRANSITIONS; WATER; FILMS; CONFINEMENT; SIMULATION; DIFFUSION; SHEAR AB We perform molecular dynamics simulations to investigate the shear dynamics of hydration water nanoconfined between two mica surfaces at 1 bar pressure and 298 K. Newtonian plateaus of shear viscosity comparable to the bulk value for different hydration layers D=0.92-2.44 nm are obtained. The origin of this persistent fluidity of the confined aqueous system is found to be closely associated with the rotational dynamics of water molecules, accompanied by fast translational diffusion under this confinement. C1 Vanderbilt Univ, Dept Chem Engn, Nashville, TN 37235 USA. Oak Ridge Natl Lab, Div Chem Sci, Oak Ridge, TN 37831 USA. Oak Ridge Natl Lab, Ctr Nanophase Mat Sci, Oak Ridge, TN 37831 USA. RP Leng, YS (reprint author), Vanderbilt Univ, Dept Chem Engn, Nashville, TN 37235 USA. RI Cummings, Peter/B-8762-2013 OI Cummings, Peter/0000-0002-9766-2216 NR 34 TC 130 Z9 133 U1 9 U2 40 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 EI 1079-7114 J9 PHYS REV LETT JI Phys. Rev. Lett. PD JAN 21 PY 2005 VL 94 IS 2 AR 026101 DI 10.1103/PhysRevLett.94.026101 PG 4 WC Physics, Multidisciplinary SC Physics GA 889YN UT WOS:000226478900048 PM 15698197 ER PT J AU Martins, GB Busser, CA Al-Hassanieh, KA Moreo, A Dagotto, E AF Martins, GB Busser, CA Al-Hassanieh, KA Moreo, A Dagotto, E TI Prediction of ferromagnetic correlations in coupled double-level quantum dots SO PHYSICAL REVIEW LETTERS LA English DT Article ID TRANSPORT; 2-IMPURITY; SYSTEM AB Numerical results for transport properties of two coupled double-level quantum dots (QDs) strongly suggest that under appropriate conditions the dots develop a novel ferromagnetic (FM) correlation at quarter filling (one electron per dot). In the strong coupling regime (Coulomb repulsion larger than electron hopping) and with interdot tunneling larger than tunneling to the leads, an S=1 Kondo resonance develops in the density of states, leading to a peak in the conductance. A qualitative "phase diagram," incorporating the new FM phase, is presented. In addition, the necessary conditions for the FM regime are less restrictive than naively believed, leading to its possible experimental observation in real QDs. C1 Oakland Univ, Dept Phys, Rochester, MI 48309 USA. Oak Ridge Natl Lab, Condensed Matter Sci Div, Oak Ridge, TN 37831 USA. Univ Tennessee, Dept Phys, Knoxville, TN 37996 USA. Florida State Univ, Dept Phys, Tallahassee, FL 32306 USA. Florida State Univ, Natl High Magnet Field Lab, Tallahassee, FL 32306 USA. RP Martins, GB (reprint author), Oakland Univ, Dept Phys, Rochester, MI 48309 USA. EM martins@oakland.edu RI Busser, Carlos/K-1017-2014; Martins, George/C-9756-2012 OI Busser, Carlos/0000-0002-0353-7490; Martins, George/0000-0001-7846-708X NR 21 TC 23 Z9 24 U1 0 U2 2 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD JAN 21 PY 2005 VL 94 IS 2 AR 026804 DI 10.1103/PhysRevLett.94.026804 PG 4 WC Physics, Multidisciplinary SC Physics GA 889YN UT WOS:000226478900061 PM 15698210 ER PT J AU Park, HK Burnstein, RA Chakravorty, A Chen, YC Choong, WS Clark, K Dukes, EC Durandet, C Felix, J Fu, Y Gidal, G Gustafson, HR Holmstrom, T Huang, M James, C Jenkins, CM Jones, T Kaplan, DM Lederman, LM Leros, N Longo, MJ Lopez, F Lu, LC Luebke, W Luk, KB Nelson, KS Perroud, JP Rajaram, D Rubin, HA Volk, J White, CG White, SL Zyla, P AF Park, HK Burnstein, RA Chakravorty, A Chen, YC Choong, WS Clark, K Dukes, EC Durandet, C Felix, J Fu, Y Gidal, G Gustafson, HR Holmstrom, T Huang, M James, C Jenkins, CM Jones, T Kaplan, DM Lederman, LM Leros, N Longo, MJ Lopez, F Lu, LC Luebke, W Luk, KB Nelson, KS Perroud, JP Rajaram, D Rubin, HA Volk, J White, CG White, SL Zyla, P CA HyperCP Collaboration TI Evidence for the decay Sigma(+) -> p mu(+) mu(-) SO PHYSICAL REVIEW LETTERS LA English DT Article AB We report the first evidence for the decay Sigma(+)-->pmu(+)mu(-) from data taken by the HyperCP (E871) experiment at Fermilab. Based on three observed events, the branching ratio is B(Sigma(+)-->pmu(+)mu(-))=[8.6(-5.4)(+6.6)(stat)+/-5.5(syst)]x10(-8). The narrow range of dimuon masses may indicate that the decay proceeds via a neutral intermediate state, Sigma(+)-->pP(0),P-0-->mu(+)mu(-) with a P-0 mass of 214.3+/-0.5 MeV/c(2) and branching ratio B(Sigma(+)-->pP(0),P-0-->mu(+)mu(-))=[3.1(-1.9)(+2.4)(stat)+/-1.5(syst)]x10(-8). C1 Univ Michigan, Ann Arbor, MI 48109 USA. Acad Sinica, Inst Phys, Taipei 11529, Taiwan. Univ Calif Berkeley, Berkeley, CA 94720 USA. Fermilab Natl Accelerator Lab, Batavia, IL 60510 USA. Univ Guanajuato, Leon 37000, Mexico. IIT, Chicago, IL 60616 USA. Univ Lausanne, CH-1015 Lausanne, Switzerland. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. Univ S Alabama, Mobile, AL 36688 USA. Univ Virginia, Charlottesville, VA 22904 USA. RP Univ Michigan, Ann Arbor, MI 48109 USA. EM mlongo@umich.edu NR 9 TC 63 Z9 65 U1 0 U2 0 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 EI 1079-7114 J9 PHYS REV LETT JI Phys. Rev. Lett. PD JAN 21 PY 2005 VL 94 IS 2 AR 021801 DI 10.1103/PhysRevLett.94.021801 PG 4 WC Physics, Multidisciplinary SC Physics GA 889YN UT WOS:000226478900013 PM 15698162 ER PT J AU Wu, YZ Schmid, AK Altman, MS Jin, XF Qiu, ZQ AF Wu, YZ Schmid, AK Altman, MS Jin, XF Qiu, ZQ TI Spin-dependent Fabry-Perot interference from a Cu thin film grown on fcc Co(001) SO PHYSICAL REVIEW LETTERS LA English DT Article ID QUANTUM-WELL STATES; ENERGY-ELECTRON MICROSCOPY; PHOTOEMISSION; COPPER; TRANSMISSION; POLARIZATION; OVERLAYERS; AU; AG AB Spin-dependent electron reflection from a Cu thin film grown on Co/Cu(001) was investigated using spin-polarized low-energy electron microscopy (SPLEEM). Fabry-Perot type interference was observed and is explained using the phase accumulation model. SPLEEM images of the Cu overlayer reveal magnetic domains in the Co underlayer, with the domain contrast oscillating with electron energy and Cu film thickness. This behavior is attributed to the spin-dependent electron reflectivity at the Cu/Co interface which leads to spin-dependent Fabry-Perot electron interference in the Cu film. C1 Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Natl Ctr Electron Microscopy, Berkeley, CA 94720 USA. Hong Kong Univ Sci & Technol, Dept Phys, Hong Kong, Hong Kong, Peoples R China. Fudan Univ, Dept Phys, Shanghai 200433, Peoples R China. Chinese Acad Sci, Int Ctr Quantum Struct, Beijing 100864, Peoples R China. RP Wu, YZ (reprint author), Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. RI wu, YiZheng/O-1547-2013; Wu, yizheng/P-2395-2014; Qiu, Zi Qiang/O-4421-2016 OI Wu, yizheng/0000-0002-9289-1271; Qiu, Zi Qiang/0000-0003-0680-0714 NR 25 TC 25 Z9 25 U1 2 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 JAN 21 PY 2005 VL 94 IS 2 AR 027201 DI 10.1103/PhysRevLett.94.027201 PG 4 WC Physics, Multidisciplinary SC Physics GA 889YN UT WOS:000226478900072 PM 15698221 ER PT J AU Guilderson, TP Reimer, PJ Brown, TA AF Guilderson, TP Reimer, PJ Brown, TA TI The boon and bane of radiocarbon dating SO SCIENCE LA English DT Editorial Material ID AGE CALIBRATION; C-14 DATA; VARIABILITY C1 Lawrence Livermore Natl Lab, Ctr Accelerator Mass Spectrometry, Livermore, CA 94550 USA. Univ Calif Santa Cruz, Inst Marine Sci, Santa Cruz, CA 95064 USA. Univ Calif Santa Cruz, Dept Ocean Sci, Santa Cruz, CA 95064 USA. RP Guilderson, TP (reprint author), Lawrence Livermore Natl Lab, Ctr Accelerator Mass Spectrometry, Livermore, CA 94550 USA. EM tguilderson@llnl.gov RI Reimer, Paula/I-5915-2015 NR 14 TC 44 Z9 44 U1 0 U2 24 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 JAN 21 PY 2005 VL 307 IS 5708 BP 362 EP 364 DI 10.1126/science.1104164 PG 3 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 890DQ UT WOS:000226492300025 PM 15661996 ER PT J AU Chevalier, ML Ryerson, FJ Tapponnier, P Finkel, RC Van der Woerd, J Li, HB Liu, Q AF Chevalier, ML Ryerson, FJ Tapponnier, P Finkel, RC Van der Woerd, J Li, HB Liu, Q TI Slip-rate measurements on the Karakorum Fault may imply secular variations in fault motion SO SCIENCE LA English DT Article ID ALTYN TAGH FAULT; SAN-ANDREAS; TIBET; SYSTEM; DEFORMATION; EVOLUTION; MORAINES; HIMALAYA; BE-10; CHINA AB Beryllium-10 surface exposure dating of offset moraines on one branch of the Karakorum Fault west of the Gar basin yields a long-term (140- to 20-thousand-year) right-lateral slip rate of similar to10.7 +/- 0.7 millimeters per year. This rate is 10 times larger than that inferred from recent InSAR analyses (similar to1 +/- 3 millimeters per year) that span similar to8 years and sample all branches of the fault. The difference in slip-rate determinations suggests-that large rate fluctuations may exist over centennial or millennial time scales. Such fluctuations would be consistent with mechanical coupling between the seismogenic, brittle-creep, and ductile shear sections of faults that reach deep into the crust. C1 Lawrence Livermore Natl Lab, Inst Geophys & Planetary Phys, Livermore, CA 94550 USA. Inst Phys Globe Strasbourg, CNRS, UMR 7578, Lab Tecton Mecan Lithosphere, F-75252 Paris 05, France. Inst Phys Globe Strasbourg, CNRS, UMR 7516, F-67084 Strasbourg, France. Chinese Acad Geol Sci, Inst Geol, Lab Continental Dynam, Beijing 100037, Peoples R China. Total Fina Elf, Total Explorat China, Beijing 100004, Peoples R China. RP Ryerson, FJ (reprint author), Lawrence Livermore Natl Lab, Inst Geophys & Planetary Phys, Livermore, CA 94550 USA. EM ryerson@ltnl.gov RI Tapponnier, .Paul/B-7033-2011; Chevalier, Marie-Luce/C-5154-2013; OI Tapponnier, .Paul/0000-0002-7135-1962; Chevalier, Marie-Luce/0000-0001-9110-2456 NR 27 TC 123 Z9 135 U1 3 U2 24 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 USA SN 0036-8075 EI 1095-9203 J9 SCIENCE JI Science PD JAN 21 PY 2005 VL 307 IS 5708 BP 411 EP 414 DI 10.1126/science.1105466 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 890DQ UT WOS:000226492300042 PM 15662010 ER PT J AU Holt, NE Zigmantas, D Valkunas, L Li, XP Niyogi, KK Fleming, GR AF Holt, NE Zigmantas, D Valkunas, L Li, XP Niyogi, KK Fleming, GR TI Carotenoid cation formation and the regulation of photosynthetic light harvesting SO SCIENCE LA English DT Article ID PHOTOSYSTEM-II; ARABIDOPSIS MUTANTS; XANTHOPHYLL CYCLE; PURPLE BACTERIA; PSBS PROTEIN; ENERGY; PLANTS; PHOTOPROTECTION; COMPLEXES; STATE AB Photosynthetic light harvesting in excess light is regulated by a process known as feedback deexcitation. Femtosecond transient absorption measurements on thylakoid membranes show selective formation of a carotenoid radical cation upon excitation of chlorophyll under conditions of maximum, steady-state feedback deexcitation. Studies on transgenic Arabidopsis thaliana plants confirmed that this carotenoid radical cation formation is correlated with feedback deexcitation and requires the presence of zeaxanthin, the specific carotenoid synthesized during high light exposure. These results indicate that energy transfer from chlorophyll molecules to a chlorophyll-zeaxanthin heterodimer, which then undergoes charge separation, is the mechanism for excess energy dissipation during feedback deexcitation. C1 Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Plant & Microbial Biol, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Phys Biosci Div, Berkeley, CA 94720 USA. RP Fleming, GR (reprint author), Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. EM grfleming@lbl.gov RI Zigmantas, Donatas/E-5541-2014 OI Zigmantas, Donatas/0000-0003-2007-5256 NR 25 TC 419 Z9 432 U1 6 U2 87 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 JAN 21 PY 2005 VL 307 IS 5708 BP 433 EP 436 DI 10.1126/science.1105833 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 890DQ UT WOS:000226492300050 PM 15662017 ER PT J AU Priedhorsky, W Bloch, JJ AF Priedhorsky, W Bloch, JJ TI Optical detection of rapidly moving objects in space SO APPLIED OPTICS LA English DT Article ID PHOTON-COUNTING DETECTORS; SYSTEMS; NOISE; PERFORMANCE; ASTRONOMY AB We compare the sensitivity of photon-counting and charged-coupled-device (CCD) imagers for rapidly moving objects. Our test case involves the detection of small objects in space, seen against a diffuse zodiacal light background, as observed from a space platform. We contrast photon-counting detectors. with excellent time resolution and negligible readout noise, against CCDs with a significantly larger quantum efficiency. For fast moving objects and small fields of view. the photon-counting detectors are able to detect significantly smaller targets. with the added benefit of providing angle-angle-time metric information in addition to high-time-resolution tight curves. For larger fields of view and Slower moving objects, the CCDs are more sensitive. These results may motivate the further development of microchannel-plate photon-counting systems and amplified CCDs for detecting and tracking space objects. (C) 2005 Optical Society of America. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Los Alamos Natl Lab, Mail Stop B241, Los Alamos, NM 87545 USA. EM wpriedhorsky@lanl.gov OI Priedhorsky, William/0000-0003-0295-9138 NR 26 TC 8 Z9 10 U1 2 U2 7 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 JAN 20 PY 2005 VL 44 IS 3 BP 423 EP 433 DI 10.1364/AO.44.000423 PG 11 WC Optics SC Optics GA 889SA UT WOS:000226461500015 PM 15717832 ER PT J AU Fragile, PC Anninos, P Gustafson, K Murray, SD AF Fragile, PC Anninos, P Gustafson, K Murray, SD TI Magnetohydrodynamic simulations of shock interactions with radiative clouds SO ASTROPHYSICAL JOURNAL LA English DT Article DE hydrodynamics; ISM : clouds; ISM : kinematics and dynamics; magnetic fields; MHD; shock waves ID REDSHIFT RADIO GALAXIES; MAGNETIC-FIELD; STAR-FORMATION; INTERSTELLAR CLOUDS; GAS CLOUDS; EQUATIONS; EVOLUTION; HYDRODYNAMICS; DIFFERENCE; ALIGNMENT AB We present results from two-dimensional numerical simulations of the interactions between magnetized shocks and radiative clouds. Our primary goal is to characterize the dynamical evolution of the shocked clouds. We perform runs in both the strong and weak magnetic field limits and consider three different field orientations. For the geometries considered, we generally find that magnetic fields external to, but concentrated near, the surface of the cloud suppress the growth of destructive hydrodynamic instabilities. External fields also increase the compression of the cloud by effectively acting as a confinement mechanism driven by the interstellar flow and local field stretching. This can have a dramatic effect on both the efficiency of radiative cooling, which tends to increase with increasing magnetic field strength, and on the size and distribution of condensed cooled fragments. In contrast, fields acting predominately internally to the cloud tend to resist compression, thereby inhibiting cooling. We observe that, even at modest strengths (beta(0) less than or similar to 100), internal fields can completely suppress low-temperature (T < 100 K) cooling in two-dimensional clouds. C1 Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. Univ Missouri, Dept Phys, Columbia, MO 65201 USA. RP Fragile, PC (reprint author), Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RI Murray, Stephen/I-8685-2016; OI Murray, Stephen/0000-0001-5597-090X; Gustafson, Kyle/0000-0002-1903-9015 NR 38 TC 39 Z9 40 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 JAN 20 PY 2005 VL 619 IS 1 BP 327 EP 339 DI 10.1086/426313 PN 1 PG 13 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 890KA UT WOS:000226508900026 ER PT J AU Nordquist, CD Goldsmith, CL Dyck, CW Kraus, GM Finnegan, PS Austin, E Sullivan, C AF Nordquist, CD Goldsmith, CL Dyck, CW Kraus, GM Finnegan, PS Austin, E Sullivan, C TI X-band RF MEMS tuned combline filter SO ELECTRONICS LETTERS LA English DT Article AB A three-pole combline filter tuning from 8.2 to 11.3 GHz using RF MEMS switched capacitors is reported. This structure, measuring 2.85 x 2.15 mm(2), allows 31% tuning with 11% 3 dB bandwidth for the four tuning states and insertion losses ranging from 4.4 to 6 dB. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. MEMtron Corp, Plano, TX USA. L&M Technol, Albuquerque, NM USA. Plus Grp, Albuquerque, NM USA. RP Nordquist, CD (reprint author), Sandia Natl Labs, POB 5800,MS 0603, Albuquerque, NM 87185 USA. EM cdnordq@sandia.gov NR 10 TC 17 Z9 17 U1 0 U2 0 PU IEE-INST ELEC ENG PI HERTFORD PA MICHAEL FARADAY HOUSE SIX HILLS WAY STEVENAGE, HERTFORD SG1 2AY, ENGLAND SN 0013-5194 J9 ELECTRON LETT JI Electron. Lett. PD JAN 20 PY 2005 VL 41 IS 2 BP 76 EP 77 DI 10.1049/el:20057375 PG 2 WC Engineering, Electrical & Electronic SC Engineering GA 894ZR UT WOS:000226830700018 ER PT J AU Zhang, Y Mascarenhas, A AF Zhang, Y Mascarenhas, A TI Total and negative refraction of electromagnetic waves SO INTERNATIONAL JOURNAL OF MODERN PHYSICS B LA English DT Review DE negative refraction; reflectionless; left-handed media; anisotropic media; photonic crystals; spatial dispersion ID PHOTONIC CRYSTALS; EXPERIMENTAL-VERIFICATION; INDEX; LENS; PERMITTIVITY; PERMEABILITY; PROPAGATION; MEDIA AB Recently there has been a great deal of interest in an unusual category of material, that is, a material that exhibits negative refractive index or more generally negative group velocity. Perhaps the most immediate application of this type of material is in an area known as total and negative refraction, which may potentially lead to many novel optical devices. The reason that the phenomenon of total and negative refraction has become so interesting to the physics community is also due largely to the notion that this phenomenon would never occur in conventional materials with positive refractive index. It turns out that total and negative refraction can be realized even in natural crystalline materials or in artificial materials (e.g. photonic crystals) without negative (effective) refractive index. In this brief review, after providing a brief historic account for the research related to finding materials with negative group velocity and achieving negative refraction, we discuss the three primary approaches that have yielded experimental demonstrations of negative refraction, in an effort to clarify the underlying physics involved with each approach. A brief discussion on the subwavelength resolution application of the negative (effective) refractive index material is also given. C1 Natl Renewable Energy Lab, Golden, CO 80401 USA. RP Zhang, Y (reprint author), Natl Renewable Energy Lab, 1617 Cole Blvd, Golden, CO 80401 USA. NR 66 TC 0 Z9 0 U1 1 U2 1 PU WORLD SCIENTIFIC PUBL CO PTE LTD PI SINGAPORE PA 5 TOH TUCK LINK, SINGAPORE 596224, SINGAPORE SN 0217-9792 J9 INT J MOD PHYS B JI Int. J. Mod. Phys. B PD JAN 20 PY 2005 VL 19 IS 1-2 BP 21 EP 33 PG 13 WC Physics, Applied; Physics, Condensed Matter; Physics, Mathematical SC Physics GA 908DR UT WOS:000227768100002 ER PT J AU Stamenkovic, V Chou, KC Somorjai, GA Ross, PN Markovic, NM AF Stamenkovic, V Chou, KC Somorjai, GA Ross, PN Markovic, NM TI Vibrational properties of CO at the Pt(111)-solution interface: the anomalous stark-tuning slope SO JOURNAL OF PHYSICAL CHEMISTRY B LA English DT Letter ID CARBON-MONOXIDE; INFRARED-SPECTROSCOPY; OXIDATION; PT(111); ADSORPTION; ELECTRODES AB Vibrational properties of CO have been studied on Pt(111) in acid and alkaline electrolytes by synchronous measurements of CO oxidation current (0.5 mV/s) and WAS spectra (one spectrum for every 1 mV). We found that in acid solutions the frequency-tuning rate (dv(CO)/dE) as well as the potential-dependent bandwidth (dDeltav(1/2)/dE) deviates from expected linear relationships. This unusual potential-dependent behavior is interpreted in terms of compression/dissipation of CO islands during the CO oxidation, engendered by competitive adsorption between inactive anions from a supporting electrolyte and the reactive OH species. C1 Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. RP Markovic, NM (reprint author), Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. EM nmmarkovic@lbl.gov RI Chou, Kuo-Chen/A-8340-2009 NR 12 TC 36 Z9 38 U1 0 U2 18 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 JAN 20 PY 2005 VL 109 IS 2 BP 678 EP 680 DI 10.1021/jp044802i PG 3 WC Chemistry, Physical SC Chemistry GA 887NQ UT WOS:000226313200003 PM 16866425 ER PT J AU Pivovar, AA Pivovar, BS AF Pivovar, AA Pivovar, BS TI Dynamic behavior of water within a polymer electrolyte fuel cell membrane at low hydration levels SO JOURNAL OF PHYSICAL CHEMISTRY B LA English DT Article ID ELASTIC NEUTRON-SCATTERING; SWOLLEN PERFLUOROSULFONATE IONOMER; SMALL-ANGLE SCATTERING; NAFION MEMBRANES; SELF-DIFFUSION; TRANSPORT; NMR; IR; MICROSTRUCTURE; NANOSTRUCTURE AB Protonic conduction across the membrane of a polymer electrolyte fuel cell is intimately related to the dynamic behavior of water present within the membrane. To further the understanding of water dynamics in these materials, quasielastic neutron scattering (QENS) has been used to investigate the picosecond dynamic behavior of water within a perfluorosulfonated ionomer (PFSI) membrane under increasing hydration levels from dry to saturation. Evaluation of the elastic incoherent structure factor (EISF) reveals an increase in the characteristic length-scale of confinement as the number of water molecules in the membrane increases. tending to an asymptotic value at saturation. The fraction of elastic incoherent scattering observed at high Q over all hydration levels is well fit by a simple model that assumes a single, nondiffusing hydronium ion per membrane sulfonic acid site. The quasielastic component of the fitted data indicates confined dynamic behavior for scattering vectors less than 0.7 Angstrom(-1). As such, the dynamic behavior was interpreted using continuous diffusion confined within a sphere at Q < 0.7 Angstrom(-1) and random unconstrained jump diffusion at 0 > 0.7 Angstrom(-1). As the number of water molecules in the membrane increases, the characteristic residence times obtained from both models is reduced. The increased dynamical frequency is further reflected in the, diffusion coefficients predicted by both models. Between low hydration (2 H2O/SO3H) and saturation (16 H2O/SO3H), the continuous spherical diffusion coefficient changes from 0.46 +/- 0.12 to 1.04 +/- 0.12 (10(-5) cm(2)/s) and jump diffusion indicates an increase from 1.21 +/- 0.03 to 2.14 +/- 0.08 (10(-5) cm(2)/s). Overall, the dynamic behavior of water has been quantified over different length scale regimes. the results of which may be rationalized on the basis of the formation of water clusters in the hydrophilic domain that expand toward an asymptotic upper limit with increased hydration. C1 NIST, Ctr Neutron Res, Gaithersburg, MD 20089 USA. Los Alamos Natl Lab, Div Mat Sci & Technol, Los Alamos, NM 87545 USA. RP Pivovar, AA (reprint author), NIST, Ctr Neutron Res, Gaithersburg, MD 20089 USA. EM adam.pivovar@nist.gov NR 48 TC 90 Z9 92 U1 1 U2 38 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 JAN 20 PY 2005 VL 109 IS 2 BP 785 EP 793 DI 10.1021/jp046029x PG 9 WC Chemistry, Physical SC Chemistry GA 887NQ UT WOS:000226313200020 PM 16866442 ER PT J AU Lei, JL McLarnon, F Kostecki, R AF Lei, JL McLarnon, F Kostecki, R TI In situ Raman microscopy of individual LiNi0.8Co0.15Al0.05O2 particles in a Li-ion battery composite cathode SO JOURNAL OF PHYSICAL CHEMISTRY B LA English DT Article ID CAPACITY FADE; ELECTRODES; IMPEDANCE; CARBON; PERFORMANCE AB Kinetic characteristics of Li+ intercalation/deintercalation into/from individual LiNi0.8Co0.15Al0.05O2 particles in a composite cathode were studied in situ using Raman microscopy during galvanostatic charge-discharge in 1.2 M LiPF6, ethylene carbonate (EC): ethyl methyl carbonate (EMC), 3:7 by volume. Ex situ spectroscopic analysis of a cathode that was removed from a tested high-power Li-ion cell, which suffered substantial power and capacity loss, showed that the state of charge (SOC) of oxide particles on the cathode surface was highly nonuniform despite deep discharge of the Li-ion cell at the end of the test. In situ monitoring of the SOC of selected oxide particles in the composite cathode in a sealed spectro-electrochemical cell revealed that the rate at which particles charge and discharge varied with time and location. The inconsistent kinetic behavior of individual oxide particles was attributed to degradation of the electronically conducting carbon matrix in the composite cathode upon testing. These local microphenomena are most likely responsible for the overall impedance rise of the cathode and contribute to the mechanism of lithium-ion cell failure. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Environm Energy Technol Div, Berkeley, CA 94720 USA. RP Kostecki, R (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Environm Energy Technol Div, Berkeley, CA 94720 USA. EM r_kostecki@lbl.gov NR 23 TC 55 Z9 56 U1 9 U2 102 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 JAN 20 PY 2005 VL 109 IS 2 BP 952 EP 957 DI 10.1021/jp046027c PG 6 WC Chemistry, Physical SC Chemistry GA 887NQ UT WOS:000226313200042 PM 16866464 ER PT J AU Hurum, DC Gray, KA Rajh, T Thurnauer, MC AF Hurum, DC Gray, KA Rajh, T Thurnauer, MC TI Recombination pathways in the Degussa P25 formulation of TiO2: Surface versus lattice mechanisms SO JOURNAL OF PHYSICAL CHEMISTRY B LA English DT Article ID TITANIUM-DIOXIDE; PHOTOCATALYTIC TRANSFORMATION; HETEROGENEOUS PHOTOCATALYSIS; CHARGE SEPARATION; OXIDE CATALYSTS; SOLAR-CELLS; THIN-FILMS; RUTILE; ANATASE; DEGRADATION AB Charge migration between electron trapping sites within the mixed-phase titania photocatalyst Degussa P25 has been studied. In addition to previously described lattice electron trapping sites on both anatase and rutile phases, surface electron trapping sites and an anatase-ruble interface trapping site specific to Degussa P25 are identified. The relationship between these sites and recombination with surface hole trapping sites is also determined. It is experimentally shown that upon band-gap illumination holes appear at the surface and preferentially recombine with electrons in surface trapping sites. These findings indicate that in nixed-phase TiO2, such as Degussa P25, photogenerated holes are trapped exclusively on the particle surface. while photogenerated electrons are trapped within the nanoparticle lattice. Recombination reactions are dominated by surface reactions that follow charge migration. These findings indicate that, in mixed-phase TiO2. such as Degussa P25, a random flight mechanism of recombination predominates. Such knowledge simplifies the mechanistic mathematical models used for process design and points the way for improving future oxidative titania catalysts. C1 Northwestern Univ, Inst Environm Catalysis, Evanston, IL 60208 USA. Northwestern Univ, Dept Civil & Environm Engn, Evanston, IL 60208 USA. Argonne Natl Lab, Div Chem, Argonne, IL 60439 USA. RP Gray, KA (reprint author), Northwestern Univ, Inst Environm Catalysis, Evanston, IL 60208 USA. RI Gray, Kimberly/B-6989-2009 NR 42 TC 236 Z9 237 U1 5 U2 121 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 JAN 20 PY 2005 VL 109 IS 2 BP 977 EP 980 DI 10.1021/jp015395d PG 4 WC Chemistry, Physical SC Chemistry GA 887NQ UT WOS:000226313200046 PM 16866468 ER PT J AU Wang, LJ Tang, RK Bonstein, T Orme, CA Bush, PJ Nancollas, GH AF Wang, LJ Tang, RK Bonstein, T Orme, CA Bush, PJ Nancollas, GH TI A new model for nanoscale enamel dissolution SO JOURNAL OF PHYSICAL CHEMISTRY B LA English DT Article ID ATOMIC-FORCE MICROSCOPY; IN-VITRO DEMINERALIZATION; RESOLUTION ELECTRON-MICROSCOPY; CALCIUM HYDROXYAPATITE POWDER; DENTAL ENAMEL; CONSTANT-COMPOSITION; SUBSURFACE DEMINERALIZATION; CRYSTAL DISSOLUTION; KINETIC CONSTRAINTS; HUMAN AMELOGENESIS AB The dissolution kinetics of human tooth enamel surfaces was investigated using nanomolar-sensitive constant composition (CC) and in situ atomic force microscopy (AFM) under simulated caries formation conditions (relative undersaturation with respect to hydroxyapatite = 0.902, pH = 4.5). Scanning electron microscopic (SEM) examination of the resulting etched enamel surfaces showed that deminerzalization, initiated at core/wall interfaces of rods, developed anisotropically along the c-axes. After an initial rapid removal of surface polishing artifacts, the dissolution rate decreased as the reaction proceeded in accordance with our recently proposed crystal dissolution model, resulting in hollow enamel cores and nanosized remaining crystallites, resistant to further dissolution. Generally, dissolution of minerals is regarded as a spontaneous reaction in which all the solid phase can be dissolved in undersaturated solutions However, the dissolution of some biominerals may be suppressed when the crystallites approach nanometer size. This studs shows that CC demineralization of enamel in acidic medium follows this new model that can be used to mimic carious lesion formation. In dissolution studies, nanosized enamel crystallites exhibit a remarkable degree of self-preservation in the fluctuating physiological milieu. C1 SUNY Buffalo, Dept Chem, Buffalo, NY 14260 USA. SUNY Buffalo, Sch Dent Med, Buffalo, NY 14260 USA. Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Nancollas, GH (reprint author), SUNY Buffalo, Dept Chem, 756 Nat Sci Complex, Buffalo, NY 14260 USA. EM ghn@buffalo.edu RI Orme, Christine/A-4109-2009 FU NIDCR NIH HHS [DE03223] NR 56 TC 46 Z9 48 U1 3 U2 27 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 JAN 20 PY 2005 VL 109 IS 2 BP 999 EP 1005 DI 10.1021/jp046451d PG 7 WC Chemistry, Physical SC Chemistry GA 887NQ UT WOS:000226313200050 PM 16866472 ER PT J AU Zhang, Y Mascarenhas, A AF Zhang, Y Mascarenhas, A TI Total and negative refraction of electromagnetic waves SO MODERN PHYSICS LETTERS B LA English DT Review DE negative refraction; reflectionless; left-handed media; anisotropic media; photonic crystals; spatial dispersion ID PHOTONIC CRYSTALS; EXPERIMENTAL-VERIFICATION; INDEX; LENS; PERMITTIVITY; PERMEABILITY; PROPAGATION; MEDIA AB Recently there has been a great deal of interest in an unusual category of material, that is, a material that exhibits negative refractive index or more generally negative group velocity. Perhaps the most immediate application of this type of material is in an area known as total and negative refraction, which may potentially lead to many novel optical devices. The reason that the phenomenon of total and negative refraction has become so interesting to the physics community is also due largely to the notion that this phenomenon would never occur in conventional materials with positive refractive index. It turns out that total and negative refraction can be realized even in natural crystalline materials or in artificial materials (e.g. photonic crystals) without negative (effective) refractive index. In this brief review, after providing a brief historic account for the research related to finding materials with negative group velocity and achieving negative refraction, we discuss the three primary approaches that have yielded experimental demonstrations of negative refraction, in an effort to clarify the underlying physics involved with each approach. A brief discussion on the subwavelength resolution application of the negative (effective) refractive index material is also given. C1 Natl Renewable Energy Lab, Golden, CO 80401 USA. RP Natl Renewable Energy Lab, 1617 Cole Blvd, Golden, CO 80401 USA. NR 65 TC 16 Z9 17 U1 0 U2 5 PU WORLD SCIENTIFIC PUBL CO PTE LTD PI SINGAPORE PA 5 TOH TUCK LINK, SINGAPORE 596224, SINGAPORE SN 0217-9849 EI 1793-6640 J9 MOD PHYS LETT B JI Mod. Phys. Lett. B PD JAN 20 PY 2005 VL 19 IS 1-2 BP 21 EP 33 DI 10.1142/S0217984905008074 PG 13 WC Physics, Applied; Physics, Condensed Matter; Physics, Mathematical SC Physics GA 919LI UT WOS:000228619100002 ER PT J AU Abazov, VM Abbott, B Abdesselam, A Abolins, M Abramov, V Acharya, BS Adams, DL Adams, M Alexeev, GD Alton, A Alves, GA Arnoud, Y Avila, C Babukhadia, L Bacon, TC Baden, A Baffioni, S Baldin, B Balm, PW Banerjee, S Barberis, E Baringer, P Barreto, J Bartlett, JF Bassler, U Bauer, D Bean, A Beaudette, F Begel, M Belyaev, A Beri, SB Bernardi, G Bertram, I Besson, A Beuselinck, R Bezzubov, VA Bhat, PC Bhatnagar, V Blazey, G Blekman, F Blessing, S Boehnlein, A Bolton, TA Borcherding, F Bos, K Bose, T Brandt, A Briskin, G Brock, R Brooijmans, G Bross, A Buchholz, D Buehler, M Buescher, V Butler, JM Canelli, F Carvalho, W Castilla-Valdez, H Chakraborty, D Chan, KM Cho, DK Choi, S Claes, D Clark, AR Connolly, B Cooper, WE Coppage, D Crepe-Renaudin, S Cummings, MAC Cutts, D da Motta, H Davis, GA De, K de Jong, SJ Demarteau, M Demina, R Demine, P Denisov, D Denisov, SP Desai, S Diehl, HT Diesburg, M Doulas, S Dudko, LV Duflot, L Dugad, SR Duperrin, A Dyshkant, A Edmunds, D Ellison, J Eltzroth, JT Elvira, VD Engelmann, R Eno, S Ermolov, P Eroshin, OV Estrada, J Evans, H Evdokimov, VN Ferbel, T Filthaut, F Fisk, HE Fortner, M Fox, H Fu, S Fuess, S Gallas, E Gao, M Gavrilov, V Genser, K Gerber, CE Gershtein, Y Ginther, G Gomez, B Goncharov, PI Gounder, K Goussiou, A Grannis, PD Greenlee, H Greenwood, ZD Grinstein, S Groer, L Grunendahl, S Gurzhiev, SN Gutierrez, G Gutierrez, P Hadley, NJ Haggerty, H Hagopian, S Hagopian, V Hall, RE Han, C Hansen, S Hauptman, JM Hebert, C Hedin, D Heinmiller, JM Heinson, AP Heintz, U Hildreth, MD Hirosky, R Hobbs, JD Hoeneisen, B Huang, J Iashvili, I Illingworth, R Ito, AS Jaffre, M Jain, S Jain, V Jesik, R Johns, K Johnson, M Jonckheere, A Jostlein, H Juste, A Kahl, W Kahn, S Kajfasz, E Kalinin, AM Karmanov, D Karmgard, D Kehoe, R Kesisoglou, S Khanov, A Kharchilava, A Klima, B Kohli, JM Kostritskiy, AV Kotcher, J Kothari, B Kozelov, AV Kozlovsky, EA Krane, J Krishnaswamy, MR Krivkova, P Krzywdzinski, S Kubantsev, M Kuleshov, S Kulik, Y Kunori, S Kupco, A Landsberg, G Lee, WM Leflat, A Lehner, F Leonidopoulos, C Li, J Li, QZ Lima, JGR Lincoln, D Linn, SL Linnemann, J Lipton, R Lueking, L Lundstedt, C Luo, C Maciel, AKA Madaras, RJ Malyshev, VL Manankov, V Mao, HS Marshall, T Martin, MI Mattingly, SEK Mayorov, AA McCarthy, R McMahon, T Melanson, HL Melnitchouk, A Merkin, M Merritt, KW Miao, C Miettinen, H Mihalcea, D Mokhov, N Mondal, NK Montgomery, HE Moore, RW Mutaf, YD Nagy, E Narain, M Narasimham, VS Naumann, NA Neal, HA Negret, JP Nelson, S Nomerotski, A Nunnemann, T O'Neil, D Oguri, V Oshima, N Padley, P Parashar, N Partridge, R Parua, N Patwa, A Peters, O Petroff, P Piegaia, R Pope, BG Prosper, HB Protopopescu, S Przybycien, MB Qian, J Rajagopalan, S Rapidis, PA Reay, NW Reucroft, S Rijssenbeek, M Rizatdinova, F Royon, C Rubinov, P Ruchti, R Sabirov, BM Sajot, G Santoro, A Sawyer, L Schamberger, RD Schellman, H Schwartzman, A Shabalina, E Shivpuri, RK Shpakov, D Shupe, M Sidwell, RA Simak, V Sirotenko, V Slattery, P Smith, RP Snow, GR Snow, J Snyder, S Solomon, J Song, Y Sorin, V Sosebee, M Sotnikova, N Soustruznik, K Souza, M Stanton, NR Steinbruck, G Stewart, D Stoker, D Stolin, V Stone, A Stoyanova, DA Strang, MA Strauss, M Strovink, M Stutte, L Sznajder, A Talby, M Taylor, W Tentindo-Repond, S Trippe, TG Turcot, AS Tuts, PM Van Kooten, R Varelas, N Villeneuve-Seguier, F Volkov, AA Wahl, HD Wang, ZM Warchol, J Watts, G Wayne, M Weerts, H White, A Whiteson, D Wijngaarden, DA Willis, S Wimpenny, SJ Womersley, J Wood, DR Xu, Q Yamada, R Yasuda, T Yatsunenko, YA Yip, K Yu, J Zhang, X Zhou, B Zhou, Z Zielinski, M Zieminska, D Zieminski, A Zutshi, V Zverev, EG Zylberstejn, A AF Abazov, VM Abbott, B Abdesselam, A Abolins, M Abramov, V Acharya, BS Adams, DL Adams, M Alexeev, GD Alton, A Alves, GA Arnoud, Y Avila, C Babukhadia, L Bacon, TC Baden, A Baffioni, S Baldin, B Balm, PW Banerjee, S Barberis, E Baringer, P Barreto, J Bartlett, JF Bassler, U Bauer, D Bean, A Beaudette, F Begel, M Belyaev, A Beri, SB Bernardi, G Bertram, I Besson, A Beuselinck, R Bezzubov, VA Bhat, PC Bhatnagar, V Blazey, G Blekman, F Blessing, S Boehnlein, A Bolton, TA Borcherding, F Bos, K Bose, T Brandt, A Briskin, G Brock, R Brooijmans, G Bross, A Buchholz, D Buehler, M Buescher, V Butler, JM Canelli, F Carvalho, W Castilla-Valdez, H Chakraborty, D Chan, KM Cho, DK Choi, S Claes, D Clark, AR Connolly, B Cooper, WE Coppage, D Crepe-Renaudin, S Cummings, MAC Cutts, D da Motta, H Davis, GA De, K de Jong, SJ Demarteau, M Demina, R Demine, P Denisov, D Denisov, SP Desai, S Diehl, HT Diesburg, M Doulas, S Dudko, LV Duflot, L Dugad, SR Duperrin, A Dyshkant, A Edmunds, D Ellison, J Eltzroth, JT Elvira, VD Engelmann, R Eno, S Ermolov, P Eroshin, OV Estrada, J Evans, H Evdokimov, VN Ferbel, T Filthaut, F Fisk, HE Fortner, M Fox, H Fu, S Fuess, S Gallas, E Gao, M Gavrilov, V Genser, K Gerber, CE Gershtein, Y Ginther, G Gomez, B Goncharov, PI Gounder, K Goussiou, A Grannis, PD Greenlee, H Greenwood, ZD Grinstein, S Groer, L Grunendahl, S Gurzhiev, SN Gutierrez, G Gutierrez, P Hadley, NJ Haggerty, H Hagopian, S Hagopian, V Hall, RE Han, C Hansen, S Hauptman, JM Hebert, C Hedin, D Heinmiller, JM Heinson, AP Heintz, U Hildreth, MD Hirosky, R Hobbs, JD Hoeneisen, B Huang, J Iashvili, I Illingworth, R Ito, AS Jaffre, M Jain, S Jain, V Jesik, R Johns, K Johnson, M Jonckheere, A Jostlein, H Juste, A Kahl, W Kahn, S Kajfasz, E Kalinin, AM Karmanov, D Karmgard, D Kehoe, R Kesisoglou, S Khanov, A Kharchilava, A Klima, B Kohli, JM Kostritskiy, AV Kotcher, J Kothari, B Kozelov, AV Kozlovsky, EA Krane, J Krishnaswamy, MR Krivkova, P Krzywdzinski, S Kubantsev, M Kuleshov, S Kulik, Y Kunori, S Kupco, A Landsberg, G Lee, WM Leflat, A Lehner, F Leonidopoulos, C Li, J Li, QZ Lima, JGR Lincoln, D Linn, SL Linnemann, J Lipton, R Lueking, L Lundstedt, C Luo, C Maciel, AKA Madaras, RJ Malyshev, VL Manankov, V Mao, HS Marshall, T Martin, MI Mattingly, SEK Mayorov, AA McCarthy, R McMahon, T Melanson, HL Melnitchouk, A Merkin, M Merritt, KW Miao, C Miettinen, H Mihalcea, D Mokhov, N Mondal, NK Montgomery, HE Moore, RW Mutaf, YD Nagy, E Narain, M Narasimham, VS Naumann, NA Neal, HA Negret, JP Nelson, S Nomerotski, A Nunnemann, T O'Neil, D Oguri, V Oshima, N Padley, P Parashar, N Partridge, R Parua, N Patwa, A Peters, O Petroff, P Piegaia, R Pope, BG Prosper, HB Protopopescu, S Przybycien, MB Qian, J Rajagopalan, S Rapidis, PA Reay, NW Reucroft, S Rijssenbeek, M Rizatdinova, F Royon, C Rubinov, P Ruchti, R Sabirov, BM Sajot, G Santoro, A Sawyer, L Schamberger, RD Schellman, H Schwartzman, A Shabalina, E Shivpuri, RK Shpakov, D Shupe, M Sidwell, RA Simak, V Sirotenko, V Slattery, P Smith, RP Snow, GR Snow, J Snyder, S Solomon, J Song, Y Sorin, V Sosebee, M Sotnikova, N Soustruznik, K Souza, M Stanton, NR Steinbruck, G Stewart, D Stoker, D Stolin, V Stone, A Stoyanova, DA Strang, MA Strauss, M Strovink, M Stutte, L Sznajder, A Talby, M Taylor, W Tentindo-Repond, S Trippe, TG Turcot, AS Tuts, PM Van Kooten, R Varelas, N Villeneuve-Seguier, F Volkov, AA Wahl, HD Wang, ZM Warchol, J Watts, G Wayne, M Weerts, H White, A Whiteson, D Wijngaarden, DA Willis, S Wimpenny, SJ Womersley, J Wood, DR Xu, Q Yamada, R Yasuda, T Yatsunenko, YA Yip, K Yu, J Zhang, X Zhou, B Zhou, Z Zielinski, M Zieminska, D Zieminski, A Zutshi, V Zverev, EG Zylberstejn, A CA D0 Collaboration TI Measurement of the top quark mass in all-jet events SO PHYSICS LETTERS B LA English DT Article DE top quark ID DECAY AB We describe a measurement of the mass of the top quark from the purely hadronic decay modes of t (t) over bar pairs using all-jet data produced in p (p) over bar collisions at roots = 1.8 TeV at the Fermilab Tevatron Collider. The data, which correspond to an integrated luminosity of 110.2 +/- 5.8 pb(-1), were collected with the DO detector from 1992 to 1996. We find a top quark mass of 178.5 +/- 13.7(stat) +/- 7.7(syst) GeV/c(2). (C) 2004 Elsevier B.V. All rights reserved. C1 Joint Inst Nucl Res, Dubna, Russia. Univ Buenos Aires, Buenos Aires, DF, Argentina. Ctr Brasileiro Pesquisas Fis, LAFEX, Rio De Janeiro, Brazil. Univ Estado Rio de Janeiro, Rio De Janeiro, Brazil. Inst High Energy Phys, Beijing 100039, Peoples R China. Univ Los Andes, Bogota, Colombia. Charles Univ Prague, Ctr Particle Phys, Prague, Czech Republic. Acad Sci Czech Republic, Inst Phys, Ctr Particle Phys, Prague, Czech Republic. Univ San Francisco, Quito, Ecuador. Univ Grenoble 1, Lab Phys Subatom & Cosmol, IN2P3, CNRS, Grenoble, France. Univ Aix Marseille 2, CPPM, IN2P3, CNRS, Marseille, France. IN2P3, CNRS, Lab Accelerateur Lineaire, Orsay, France. Univ Paris 06, LPNHE, IN2P3, CNRS, Paris, France. Univ Paris 07, LPNHE, IN2P3, CNRS, Paris, France. CEA, DAPNIA, Serv Phys Particules, Saclay, France. Univ Freiburg, Inst Phys, Freiburg, Germany. Panjab Univ, Chandigarh 160014, India. Univ Delhi, Delhi 110007, India. Tata Inst Fundamental Res, Bombay 400005, Maharashtra, India. CINVESTAV, Mexico City 14000, DF, Mexico. NIKHEF H, FOM Inst, Amsterdam, Netherlands. Univ Amsterdam, NIKHEF, Amsterdam, Netherlands. Univ Nijmegen, NIKHEF H, Nijmegen, Netherlands. Joint Inst Nucl Res, Dubna, Russia. Inst Theoret & Expt Phys, Moscow 117259, Russia. Moscow MV Lomonosov State Univ, Moscow, Russia. Inst High Energy Phys, Protvino, Russia. Univ Lancaster, Lancaster, England. Univ London Imperial Coll Sci Technol & Med, London, England. Univ Arizona, Tucson, AZ 85721 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. Calif State Univ Fresno, Fresno, CA 93740 USA. Univ Calif Irvine, Irvine, CA 92697 USA. Univ Calif Riverside, Riverside, CA 92521 USA. Florida State Univ, Tallahassee, FL 32306 USA. Fermilab Natl Accelerator Lab, Batavia, IL 60510 USA. Univ Illinois, Chicago, IL 60607 USA. No Illinois Univ, De Kalb, IL 60115 USA. Northwestern Univ, Evanston, IL 60208 USA. Indiana Univ, Bloomington, IN 47405 USA. Univ Notre Dame, Notre Dame, IN 46556 USA. Iowa State Univ Sci & Technol, Ames, IA 50011 USA. Univ Kansas, Lawrence, KS 66045 USA. Kansas State Univ, Manhattan, KS 66506 USA. Louisiana Tech Univ, Ruston, LA 71272 USA. Univ Maryland, College Pk, MD 20742 USA. Boston Univ, Boston, MA 02215 USA. Northeastern Univ, Boston, MA 02115 USA. Univ Michigan, Ann Arbor, MI 48109 USA. Michigan State Univ, E Lansing, MI 48824 USA. Univ Nebraska, Lincoln, NE 68588 USA. Columbia Univ, New York, NY 10027 USA. Univ Rochester, Rochester, NY 14627 USA. SUNY Stony Brook, Stony Brook, NY 11794 USA. Brookhaven Natl Lab, Upton, NY 11973 USA. Langston Univ, Langston, OK 73050 USA. Univ Oklahoma, Norman, OK 73019 USA. Brown Univ, Providence, RI 02912 USA. Univ Texas, Arlington, TX 76019 USA. Rice Univ, Houston, TX 77005 USA. Univ Virginia, Charlottesville, VA 22901 USA. Univ Washington, Seattle, WA 98195 USA. RP Abazov, VM (reprint author), Joint Inst Nucl Res, Dubna, Russia. RI Grinstein, Sebastian/N-3988-2014; Sznajder, Andre/L-1621-2016; Canelli, Florencia/O-9693-2016; Juste, Aurelio/I-2531-2015; Gutierrez, Phillip/C-1161-2011; Dudko, Lev/D-7127-2012; Leflat, Alexander/D-7284-2012; Merkin, Mikhail/D-6809-2012; Yip, Kin/D-6860-2013; Kuleshov, Sergey/D-9940-2013; De, Kaushik/N-1953-2013; Oguri, Vitor/B-5403-2013; Alves, Gilvan/C-4007-2013; Belyaev, Alexander/F-6637-2015; Nomerotski, Andrei/A-5169-2010; Shivpuri, R K/A-5848-2010 OI Blekman, Freya/0000-0002-7366-7098; Blazey, Gerald/0000-0002-7435-5758; Evans, Harold/0000-0003-2183-3127; Beuselinck, Raymond/0000-0003-2613-7446; Heinson, Ann/0000-0003-4209-6146; grannis, paul/0000-0003-4692-2142; Qian, Jianming/0000-0003-4813-8167; Bean, Alice/0000-0001-5967-8674; Strovink, Mark/0000-0001-7020-7769; Madaras, Ronald/0000-0001-7399-2993; Begel, Michael/0000-0002-1634-4399; Grinstein, Sebastian/0000-0002-6460-8694; Melnychuk, Oleksandr/0000-0002-2089-8685; Bassler, Ursula/0000-0002-9041-3057; Filthaut, Frank/0000-0003-3338-2247; Naumann, Axel/0000-0002-4725-0766; Bertram, Iain/0000-0003-4073-4941; Sznajder, Andre/0000-0001-6998-1108; Canelli, Florencia/0000-0001-6361-2117; Sawyer, Lee/0000-0001-8295-0605; Hedin, David/0000-0001-9984-215X; Wahl, Horst/0000-0002-1345-0401; Juste, Aurelio/0000-0002-1558-3291; de Jong, Sijbrand/0000-0002-3120-3367; Landsberg, Greg/0000-0002-4184-9380; Blessing, Susan/0000-0002-4455-7279; Gershtein, Yuri/0000-0002-4871-5449; Duperrin, Arnaud/0000-0002-5789-9825; Hoeneisen, Bruce/0000-0002-6059-4256; Leonidopoulos, Christos/0000-0002-7241-2114; Dudko, Lev/0000-0002-4462-3192; Yip, Kin/0000-0002-8576-4311; Kuleshov, Sergey/0000-0002-3065-326X; De, Kaushik/0000-0002-5647-4489; Belyaev, Alexander/0000-0002-1733-4408; NR 25 TC 15 Z9 15 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0370-2693 EI 1873-2445 J9 PHYS LETT B JI Phys. Lett. B PD JAN 20 PY 2005 VL 606 IS 1-2 BP 25 EP 33 DI 10.1016/j.physletb.2004.11.071 PG 9 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 889ID UT WOS:000226435800004 ER PT J AU Lane, GJ Maier, KH Byrne, AP Dracoulis, GD Broda, R Fornal, B Carpenter, MP Clark, RM Cromaz, M Janssens, RVF Macchiavelli, AO Wiedenhover, I Vetter, K AF Lane, GJ Maier, KH Byrne, AP Dracoulis, GD Broda, R Fornal, B Carpenter, MP Clark, RM Cromaz, M Janssens, RVF Macchiavelli, AO Wiedenhover, I Vetter, K TI High-spin isomers and three-neutron valence configurations in Pb-211 SO PHYSICS LETTERS B LA English DT Article DE nuclear structure; gamma-ray transitions; isomers; shell model; neutron-rich nuclei; deep-inelastic collisions; multi-nucleon transfer ID GAMMA-SPECTROSCOPY; STATES; COLLISIONS; MOMENTS; NUCLEI AB Deep-inelastic reactions between a beam of 1360 MeV Pb-208 ions and a thick U-238 target have been used to populate the neutron-rich nucleus Pb-211. The observation of its gamma decay has allowed identification of excited states up to the highest spin which can be formed from the three valence neutrons, including identification of three high-spin isomers. Level energies and transition strengths are compared to shell-model calculations with empirical interactions and predictions are made for the expected behaviour of more neutron-rich lead isotopes. The evidence for a possible increase in the neutron effective charge moving away from the N = 126 shell gap is evaluated. (C) 2004 Elsevier B.V. All rights reserved. C1 Australian Natl Univ, Dept Nucl Phys, RS Phys SE, Canberra, ACT 0200, Australia. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. H Niewodniczanski Inst Nucl Phys, PL-31342 Krakow, Poland. Argonne Natl Lab, Div Phys, Argonne, IL 60439 USA. RP Lane, GJ (reprint author), Australian Natl Univ, Dept Nucl Phys, RS Phys SE, Canberra, ACT 0200, Australia. EM gregory.lane@anu.edu.au RI Dracoulis, George/A-8123-2008; Lane, Gregory/A-7570-2011; Carpenter, Michael/E-4287-2015; OI Lane, Gregory/0000-0003-2244-182X; Carpenter, Michael/0000-0002-3237-5734; Byrne, Aidan/0000-0002-7096-6455 NR 24 TC 13 Z9 13 U1 0 U2 4 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0370-2693 J9 PHYS LETT B JI Phys. Lett. B PD JAN 20 PY 2005 VL 606 IS 1-2 BP 34 EP 42 DI 10.1016/j.physletb.2004.11.065 PG 9 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 889ID UT WOS:000226435800005 ER PT J AU Kryjevski, A Schafer, T AF Kryjevski, A Schafer, T TI An effective theory for baryons in the CFL phase SO PHYSICS LETTERS B LA English DT Article ID HIGH-DENSITY QCD; COLOR-FLAVOR LOCKING; QUARK MATTER; SYMMETRY-BREAKING; SUPERCONDUCTOR AB We study the effective field theory for fermions in the color-flavor locked (CFL) phase of high density QCD. The effective theory contains a flavor nonet of baryons interacting with a nonet of pseudoscalar Goldstone bosons as well as a singlet scalar Goldstone boson. The theory is similar to chiral perturbation theory in the one-baryon sector. We explain how to incorporate quark mass terms and study the spectrum as a function of the strange quark mass. Without meson condensation gapless baryon modes appears if the strange quark mass exceeds a critical value m(S)(2)/(2(PF)) = Delta, where (PF) is the Fermi momentum and Delta is the gap in the chiral limit. We show that kaon condensation leads to a rearrangement of the baryon spectrum and shifts the critical strange quark mass for the appearance of a gapless mode to higher values. (C) 2004 Elsevier B.V. All rights reserved. C1 Univ Washington, Inst Nucl Theory, Seattle, WA 98195 USA. N Carolina State Univ, Dept Phys, Raleigh, NC 27695 USA. Brookhaven Natl Lab, Riken BNL Res Ctr, Upton, NY 11973 USA. RP Kryjevski, A (reprint author), Univ Washington, Inst Nucl Theory, Seattle, WA 98195 USA. EM tmschaef@unity.ncsu.edu OI Schaefer, Thomas/0000-0002-2297-782X NR 34 TC 31 Z9 32 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 JAN 20 PY 2005 VL 606 IS 1-2 BP 52 EP 58 DI 10.1016/j.physletb.2004.11.081 PG 7 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 889ID UT WOS:000226435800007 ER PT J AU Bidder, SJ Bjerrum-Bohr, NEJ Dixon, LJ Dunbar, DC AF Bidder, SJ Bjerrum-Bohr, NEJ Dixon, LJ Dunbar, DC TI N=1 supersymmetric one-loop amplitudes and the holomorphic anomaly of unitarity cuts SO PHYSICS LETTERS B LA English DT Article ID GAUGE-THEORIES; GLUON SCATTERING; BREMSSTRAHLUNG AB Recently, it has been shown that the holomorphic anomaly of unitarity cuts can be used as a tool in determining the one-loop amplitudes in N = 4 super-Yang-Mills theory. It is interesting to examine whether this method can be applied to more general cases. We present results for a non-MHV N = 1 supersymmetric one-loop amplitude. We show that the holomorphic anomaly of each unitarity cut correctly reproduces the action on the amplitude's imaginary part of the differential operators corresponding to collinearity in twistor space. We find that the use of the holomorphic anomaly to evaluate the amplitude requires the solution of differential rather than algebraic equations. (C) 2004 Elsevier B.V. All rights reserved. C1 Univ Coll Swansea, Dept Phys, Swansea SA2 8PP, W Glam, Wales. Stanford Univ, Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. RP Bidder, SJ (reprint author), Univ Coll Swansea, Dept Phys, Swansea SA2 8PP, W Glam, Wales. EM d.c.dunbar@swansea.ac.uk RI Bjerrum-Bohr, Niels Emil Jannik/N-4551-2014; OI Bjerrum-Bohr, Niels Emil Jannik/0000-0002-4894-5412; dunbar, david/0000-0003-2433-1675 NR 37 TC 71 Z9 71 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 JAN 20 PY 2005 VL 606 IS 1-2 BP 189 EP 201 DI 10.1016/j.physletb.2004.11.073 PG 13 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 889ID UT WOS:000226435800026 ER PT J AU Polop, C Hansen, H Langenkamp, W Zhong, Z Busse, C Linke, U Kotrla, M Feibelman, PJ Michely, T AF Polop, C Hansen, H Langenkamp, W Zhong, Z Busse, C Linke, U Kotrla, M Feibelman, PJ Michely, T TI Oscillatory interaction between O impurities and Al adatoms on Al(111) and its effect on nucleation and growth SO SURFACE SCIENCE LA English DT Article DE scanning tunneling microscopy; growth; nucleation; surface diffusion; aluminum; adatoms; density functional calculations; Monte Carlo simulations ID ADSORBATE-ADSORBATE INTERACTIONS; INITIO MOLECULAR-DYNAMICS; TOTAL-ENERGY CALCULATIONS; WEAK CORRUGATION REGIME; WAVE BASIS-SET; SURFACE MIGRATION; SELF-DIFFUSION; ULTRASOFT PSEUDOPOTENTIALS; CRYSTAL-GROWTH; DEFECT SITES AB We present a combined experimental and theoretical study of submonolayer growth in the presence of predeposited immobile impurities. Scanning tunneling microscopy measurements of Al/Al(1 1 1) epitaxy in the presence of oxygen adsorbates show that immobile O impurities influence all aspects of the early stages of homoepitaxial growth on Al(1 1 1). Possible scenarios for modified growth are investigated using kinetic Monte Carlo simulations. Dependences of island density on temperature, impurity concentration and strength and type of adatom-impurity interaction are compared. The comparison shows that the morphology of the growing Al film cannot result from only one interaction type: attractive or repulsive. An oscillatory interaction, suggested by ab initio calculations, is proposed to explain the behavior of the system. (C) 2004 Elsevier B.V. All rights reserved. C1 Rhein Westfal TH Aachen, Inst Phys 1, D-52056 Aachen, Germany. Forschungszentrum Julich, ISG 3, D-52425 Julich, Germany. Acad Sci Czech Republic, Inst Phys, Prague 18221 8, Czech Republic. Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Rhein Westfal TH Aachen, Inst Phys 1, D-52056 Aachen, Germany. EM polop@physik.rwth-aachen.de RI Busse, Carsten/A-7485-2008; Kotrla, Miroslav/C-2136-2014 OI Busse, Carsten/0000-0001-5522-0578; Kotrla, Miroslav/0000-0001-8273-1402 NR 54 TC 4 Z9 4 U1 0 U2 5 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 JAN 20 PY 2005 VL 575 IS 1-2 BP 89 EP 102 DI 10.1016/j.susc.2004.11.010 PG 14 WC Chemistry, Physical; Physics, Condensed Matter SC Chemistry; Physics GA 894WS UT WOS:000226822900013 ER PT J AU Zhao, XY Hrbek, J Rodriguez, JA AF Zhao, XY Hrbek, J Rodriguez, JA TI The decomposition and chemistry of Ru-3(CO)(12) on TiO2(110) studied with X-ray photoelectron spectroscopy and temperature programmed desorption SO SURFACE SCIENCE LA English DT Article DE ruthenium carbonyl; titania; surface reaction; X-ray photoelectron spectroscopy; temperature programmed desorption; sulfur dioxide; ruthenium oxide ID ULTRAHIGH-VACUUM; ADSORPTION; SURFACES; NANOPARTICLES; DEPOSITION; METAL; TIO2; GOLD; TRIS(ALLYL)RHODIUM; ACTIVATION AB The decomposition process of triruthenium dodecacarbonyl (Ru-3(CO)(12)) on single crystal TiO2(1 1 0) has been investigated using synchrotron-based high resolution photoemission spectroscopy and temperature programmed desorption (TPD). Ruthenium carbonyl adsorbs molecularly on TiO2(1 1 0) at 100 K. When dosing at room temperature, the molecule dissociatively adsorbs forming a Ru-3(CO)(m) (m less than or equal to 10) species on the surface. TPD spectra for ruthenium carbonyl dosed at 100 K and 300 K are quite different in peak numbers and shape, indicating that the ruthenium carbonyl decomposition is sensitive to the preparation procedure. Both TPD and photoemission demonstrate that around 700 K, the decarbonylation process is completed yielding almost pure Ru particles. A small amount of CO adsorbs on the obtained Ru particles after large CO exposures (60-100 L) at 300 K. The Ru particles can be oxidized to form RuO2 at 600 K with an O-2 pressure of similar to1 x 10(-6) Torr (>400 L exposure). In addition, the chemical activity of the Ru metal particles dispersed on TiO2(1 1 0) has also been examined with SO2 and compared to that of a Ru(0 0 1) single crystal. SO2 is easily decomposed by the Ru particles at room temperature, producing S and O adatoms. SO4 is the main product of the reaction of SO2 with the titania support, and the presence of the Ru particles favors a SO4.ads --> S-ads + nO(ads) + mO(2.gas) transformation at elevated temperature. (C) 2004 Elsevier B.V. All rights reserved. C1 Brookhaven Natl Lab, Dept Chem, Upton, NY 11973 USA. RP Rodriguez, JA (reprint author), Brookhaven Natl Lab, Dept Chem, Upton, NY 11973 USA. EM rodrigez@bnl.gov RI Hrbek, Jan/I-1020-2013 NR 29 TC 13 Z9 13 U1 2 U2 10 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0039-6028 J9 SURF SCI JI Surf. Sci. PD JAN 20 PY 2005 VL 575 IS 1-2 BP 115 EP 124 DI 10.1016/j.susc.2004.11.012 PG 10 WC Chemistry, Physical; Physics, Condensed Matter SC Chemistry; Physics GA 894WS UT WOS:000226822900015 ER PT J AU Rogers, RN AF Rogers, RN TI Studies on the radiocarbon sample from the Shroud of Turin SO THERMOCHIMICA ACTA LA English DT Article DE Shroud of Turin; lignin kinetics; pyrolysis/mass spectrometry; flax fiber analyses AB In 1988, radiocarbon laboratories at Arizona, Cambridge, and Zurich determined the age of a sample from the Shroud of Turin. They reported that the date of the cloth's production lay between A.D. 1260 and 1390 with 95% confidence. This came as a surprise in view of the technology used to produce the cloth, its chemical composition, and the lack of vanillin in its lignin. The results prompted questions about the validity of the sample. Preliminary estimates of the kinetics constants for the loss of vanillin from lignin indicate a much older age for the cloth than the radiocarbon analyses. The radiocarbon sampling area is uniquely coated with a yellow-brown plant gum containing dye lakes. Pyrolysis-mass-spectrometry results from the sample area coupled with microscopic and microchemical observations prove that the radiocarbon sample was not part of the original cloth of the Shroud of Turin. The radiocarbon date was thus not valid for determining the true age of the shroud. (C) 2004 Elsevier B.V. All rights reserved. C1 Los Alamos Natl Lab, Los Alamos, NM 87544 USA. RP Rogers, RN (reprint author), Los Alamos Natl Lab, 1961 Cumbres Patio, Los Alamos, NM 87544 USA. EM rnrogers@att.net NR 8 TC 29 Z9 29 U1 3 U2 29 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0040-6031 J9 THERMOCHIM ACTA JI Thermochim. Acta PD JAN 20 PY 2005 VL 425 IS 1-2 BP 189 EP 194 DI 10.1016/j.tca.2004.09.029 PG 6 WC Thermodynamics; Chemistry, Analytical; Chemistry, Physical SC Thermodynamics; Chemistry GA 893OJ UT WOS:000226728800024 ER PT J AU Salve, R Kneafsey, TJ AF Salve, R Kneafsey, TJ TI Vapor-phase transport in the near-drift environment at Yucca Mountain SO WATER RESOURCES RESEARCH LA English DT Article ID EXCLUSION PROBLEM; SEEPAGE; CAVITIES; NEVADA; TESTS; MODEL; FLOW; TUFF AB [1] A key issue regarding the performance of the potential high- level radioactive waste repository at Yucca Mountain, Nevada, is the likelihood of precipitation percolating a vertical distance of similar to 300 m through fractured unsaturated rock into drifts containing waste packages. Water enhances waste package corrosion and is required for transport of released radionuclides. To evaluate the propensity for seepage into tunnels at Yucca Mountain, a 5- m- diameter, 2.7- km- long tunnel, commonly referred to as the Cross Drift ( CD), was excavated in 1998, branching off from the main Exploratory Studies Facility tunnel. Sections of this tunnel have been isolated from ventilation for extended periods over the last 4 years. We present continuous measurements of relative humidity and temperature and periodic observations of liquid water in the CD over two periods. During this observation duration the terminal section of the drift was partitioned into four sections by bulkheads, and ventilation to these sections was minimized to a few days. We compare these observations to results from analytical and numerical models to investigate processes associated with the movement of water vapor between the tunnel bore and the surrounding fractured rock formation. Observations from this effort indicate that fractures can be primary paths for unsaturated zone vapor flow in the immediate vicinity of emplacement drifts. Observations, measurements, and analysis indicate the need for a model that includes fracture- dominated vapor transport as a significant contributor to total water flow into the drifts. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Div Earth Sci, Berkeley, CA 94720 USA. RP Salve, R (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Div Earth Sci, 1 Cyclotron Rd, Berkeley, CA 94720 USA. EM r_salve@lbl.gov; tjkneafsey@lbl.gov RI Kneafsey, Timothy/H-7412-2014 OI Kneafsey, Timothy/0000-0002-3926-8587 NR 21 TC 3 Z9 3 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0043-1397 J9 WATER RESOUR RES JI Water Resour. Res. PD JAN 20 PY 2005 VL 41 IS 1 AR W01012 DI 10.1029/2004WR003373 PG 17 WC Environmental Sciences; Limnology; Water Resources SC Environmental Sciences & Ecology; Marine & Freshwater Biology; Water Resources GA 891LI UT WOS:000226582100002 ER PT J AU Ferrizz, RM Stuecker, JN Cesarano, J Miller, JE AF Ferrizz, RM Stuecker, JN Cesarano, J Miller, JE TI Monolithic supports with unique geometries and enhanced mass transfer SO INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH LA English DT Article ID FOAM CATALYST SUPPORTS; HEAT-TRANSFER; COMBUSTION; OXIDATION; METHANE; REACTORS; SYSTEMS AB Novel monolithic catalyst supports with regular three-dimensional structure and channel-to-channel interconnectivity have been fabricated using a direct ceramic fabrication technique known as "robocasting". Using the oxidation of CO over a Pt/gamma-Al2O3 catalyst as a probe reaction, we have quantified the mass transfer over several new geometries and compared them to traditional straight-channel monolithic supports. A geometry of alternating rods that presents no line-of-sight flow paths and about 45% void volume increases the dimensionless Sherwood number by a factor of 3 over that of traditional honeycomb supports. However, the resulting pressure drop is similar to that of a packed bed (up to a 1000-fold increase). A similar robocast structure with 74% void volume improves the Sherwood number by a factor of about 1.5 relative to the honeycomb geometry but only increases the pressure drop by a factor of 4. The results illustrate that robocasting technology affords an unprecedented degree of freedom, allowing optimization of ceramic monoliths for specific applications. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Miller, JE (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. EM jemille@sandia.gov RI Miller, James/C-1128-2011 OI Miller, James/0000-0001-6811-6948 NR 28 TC 11 Z9 11 U1 0 U2 20 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0888-5885 J9 IND ENG CHEM RES JI Ind. Eng. Chem. Res. PD JAN 19 PY 2005 VL 44 IS 2 BP 302 EP 308 DI 10.1021/ie049468r PG 7 WC Engineering, Chemical SC Engineering GA 888BM UT WOS:000226349200009 ER PT J AU Kleinman, LI Daum, PH Lee, YN Nunnermacker, LJ Springston, SR Weinstein-Lloyd, J Rudolph, J AF Kleinman, LI Daum, PH Lee, YN Nunnermacker, LJ Springston, SR Weinstein-Lloyd, J Rudolph, J TI A comparative study of ozone production in five U.S. metropolitan areas SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID MIDDLE TENNESSEE OZONE; NASHVILLE URBAN PLUME; POWER-PLANT PLUMES; TEXAS AIR-QUALITY; NEW-YORK-CITY; SOUTHERN OXIDANTS; UNITED-STATES; STAGNATION EPISODE; TROPOSPHERIC OZONE; ATMOSPHERIC CHEMISTRY AB We present observations of O-3 and O-3 precursors measured at mid boundary layer altitude during field campaigns in Nashville, Tennessee (1995), New York City, New York (1996), Phoenix, Arizona (1998), Philadelphia, Pennsylvania (1999), and Houston, Texas (2000). Ozone production rates P(O-3) and their sensitivity to NOx and volatile organic carbons (VOCs) are calculated using observed concentrations as inputs to a steady state box model. City to city comparisons are made to illustrate common features of urban photochemistry and features that are unique to specific cities. Ozone production rates vary from nearly zero to 155 ppb h(-1). Differences in P(O-3) depend on precursor concentrations, namely, radical sources, NOx and VOCs. Under conditions where P(O-3) is greater than 25 ppb h(-1), there is a potential to produce enough same-day O-3 to transform a typical regional background into a severe O-3 episode. Six such cases were observed, in Nashville, Philadelphia, and Houston, with elevated O-3 concentrations in the afternoon (130-211 ppb) following a morning in which P(O-3) was 25-140 ppb h(-1). High P(O-3) occurs when NOx concentrations are 5-25 ppb and OH-VOC reactivity is above 5 s(-1). These conditions are infrequent, and aside from a common dependence on calm winds, reasons vary from city to city. In Nashville, high P(O-3) was observed during a stagnation event over downtown and under the circumstance that an air mass with a high concentration of isoprene encountered a NOx source. In Houston, NOx and light olefins are coemitted from petrochemical facilities leading to the highest P(O-3)s of the five cities studied. High values of P(O-3) did not occur in Phoenix because of low radical production, caused mainly by a dry atmosphere, and a low VOC to NOx ratio. The sensitivity of P(O-3) to its precursors varied from NOx limited in rural samples to VOC limited near emission sources. In Philadelphia, and especially Phoenix, the highest O-3 production rates occurred under VOC-limited conditions. In Nashville, New York City, and Houston the high-P(O-3) samples were near the ridge line where P(O-3) responds somewhat to VOC reductions but is insensitive to NOx changes. C1 Brookhaven Natl Lab, Div Atmospher Sci, Upton, NY 11973 USA. SUNY Coll Old Westbury, Dept Chem Phys, Old Westbury, NY 11568 USA. York Univ, Dept Chem, N York, ON M3J 1P3, Canada. York Univ, Ctr Atmospher Res, N York, ON M3J 1P3, Canada. RP Kleinman, LI (reprint author), Brookhaven Natl Lab, Div Atmospher Sci, Upton, NY 11973 USA. EM kleinman@bnl.gov; phdaum@bnl.gov; ynlee@bnl.gov; lindan@bnl.gov; srs@bnl.gov; jlloyd@bnl.gov NR 72 TC 55 Z9 56 U1 8 U2 42 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X EI 2169-8996 J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD JAN 19 PY 2005 VL 110 IS D2 AR D02301 DI 10.1029/2004JD005096 PG 20 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 891KE UT WOS:000226579000003 ER PT J AU Fak, B McMorrow, DF Niklowitz, PG Raymond, S Ressouche, E Flouquet, J Canfield, PC Bud'ko, SL Janssen, Y Gutmann, MJ AF Fak, B McMorrow, DF Niklowitz, PG Raymond, S Ressouche, E Flouquet, J Canfield, PC Bud'ko, SL Janssen, Y Gutmann, MJ TI An inelastic neutron scattering study of single-crystal heavy-fermion YbAgGe SO JOURNAL OF PHYSICS-CONDENSED MATTER LA English DT Article ID MAGNETIC FLUCTUATIONS; EXCITATIONS; SYSTEMS AB Single crystals of the heavy-fermion compound YbAgGe have been studied by neutron scattering. The magnetic ordering occurring below T, 0.5 K is characterized by a commensurate propagation vector k = (1/3, 0, 1/3) and the moments in the basal plane of the hexagonal structure. The dynamic magnetic susceptibility is dominated by quasielastic spin fluctuations with a characteristic energy F(q)(T) of the order of I meV. The spins fluctuate predominantly in the basal plane. No spin-wave excitations are observed in the magnetically ordered phase. Below the Kondo temperature, T(K) similar to 20 K, 17,(T) shows a strong q-dependence for wavevectors along the c* direction, but is q-independent in the basal plane. Gamma(q)(T) initially shows a rapid increase with temperature T at the antiferromagnetic zone centre, but follows a standard rootT law for other q values and for T > TK in general. These observations classify YbAgGe as a well-behaved heavy-fermion compound with a particular q-dependence of the antiferromagnetic spin fluctuations, possibly related to the geometrical frustration of the Yb(3+) ions. C1 Commissariat Energie Atom, Dept Rech Fondamentale Mat Condense, SPSMS, F-38054 Grenoble, France. UCL, Dept Phys & Astron, London WC1E 6BT, England. Iowa State Univ, Dept Phys & Astron, Ames Lab, Ames, IA 50010 USA. Rutherford Appleton Lab, ISIS Facil, Didcot OX11 0QX, Oxon, England. RP Fak, B (reprint author), Commissariat Energie Atom, Dept Rech Fondamentale Mat Condense, SPSMS, F-38054 Grenoble, France. RI McMorrow, Desmond/C-2655-2008; Canfield, Paul/H-2698-2014 OI McMorrow, Desmond/0000-0002-4947-7788; NR 25 TC 20 Z9 20 U1 1 U2 12 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0953-8984 J9 J PHYS-CONDENS MAT JI J. Phys.-Condes. Matter PD JAN 19 PY 2005 VL 17 IS 2 BP 301 EP 311 DI 10.1088/0953-8984/17/2/006 PG 11 WC Physics, Condensed Matter SC Physics GA 896XV UT WOS:000226968700013 ER PT J AU Kim, H Achermann, M Balet, LP Hollingsworth, JA Klimov, VI AF Kim, H Achermann, M Balet, LP Hollingsworth, JA Klimov, VI TI Synthesis and characterization of Co/CdSe core/shell nanocomposites: Bifunctional magnetic-optical nanocrystals SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Article ID SHELL QUANTUM DOTS; NANOPARTICLES; CORE; TEMPERATURE; EXCITON; SYSTEM; DECAY; DARK C1 Los Alamos Natl Lab, Div Chem, CPCS, Los Alamos, NM 87545 USA. RP Klimov, VI (reprint author), Los Alamos Natl Lab, Div Chem, CPCS, Los Alamos, NM 87545 USA. EM klimov@lanl.gov RI Achermann, Marc/A-1849-2011 OI Achermann, Marc/0000-0002-3939-9309 NR 28 TC 365 Z9 375 U1 9 U2 95 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 JAN 19 PY 2005 VL 127 IS 2 BP 544 EP 546 DI 10.1021/ja047107x PG 3 WC Chemistry, Multidisciplinary SC Chemistry GA 887RZ UT WOS:000226324500035 PM 15643877 ER PT J AU Sadow, AD Tilley, TD AF Sadow, AD Tilley, TD TI Synthesis and characterization of scandium silyl complexes of the type CP*2ScSiHRR '. sigma-Bond metathesis reactions and catalytic dehydrogenative silation of hydrocarbons SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Review ID C-H BONDS; LUTETIUM HYDRIDE COMPLEXES; CARBON-HYDROGEN; LOWER ALKANES; SI-H; ENHANCED REACTIVITY; LOW-TEMPERATURE; H/D EXCHANGE; ACTIVATION REACTIONS; IRIDIUM CATALYSTS AB The scandium dihydrosilyl complexes Cp*2ScSiH2R (R = Mes (4), Trip (5), SiPh3 (6), Si(SiMe3)(3) (7); Mes = 2,4,6-Me3C6H2, Trip = 2,4,6-(Pr3C6H2)-Pr-i) and Cp*2ScSiH(SiMe3)(2) (8) were synthesized by addition of the appropriate hydrosilane to Cp*2ScMe (1). Studies of these complexes in the context of hydrocarbon activation led to discovery of catalytic processes for the dehydrogenative silation of hydrocarbons (including methane, isobutene and cyclopropane) with Ph2SiH2 via sigma-bond metathesis. C1 Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. Lawrence Berkeley Lab, Div Chem Sci, Berkeley, CA 94720 USA. RP Tilley, TD (reprint author), Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. EM tdtilley@socrates.berkeley.edu NR 109 TC 90 Z9 90 U1 0 U2 21 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 JAN 19 PY 2005 VL 127 IS 2 BP 643 EP 656 DI 10.1021/ja040141r PG 14 WC Chemistry, Multidisciplinary SC Chemistry GA 887RZ UT WOS:000226324500047 PM 15643889 ER PT J AU George, SD Brant, P Solomon, EI AF George, SD Brant, P Solomon, EI TI Metal and ligand K-Edge XAS of organotitanium complexes: Metal 4p and 3d contributions to pre-edge intensity and their contributions to bonding SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Article ID X-RAY-ABSORPTION; TITANOCENE DICHLORIDE; CRYSTAL-STRUCTURES; OXIDATION-STATE; FINE-STRUCTURE; TITANIUM; POLYMERIZATION; CATALYSTS; SPECTRA; STYRENE AB Titanium cyclopentadienyl (Cp) complexes play important roles as homogeneous polymerization catalysts and have recently received attention as potential anticancer agents. To systematically probe the contribution of the Cp to bonding in organotitanium complexes, Ti K-edge XAS has been applied to TiCl2 and then to the mono- and bis-Cp complexes, TiCpCl3 and TiCp2Cl2. Ti K-edge XAS is used as a direct probe of metal 3d-4p mixing and provides insight into the contribution of the Cp to bonding. These data are complimented by Cl K-edge XAS data, which provide a direct probe of the effect of the Cp on the bonding to the spectator chloride ligand. The experimental results are correlated to DFT Calculations. A model for metal 3d-4p mixing is proposed, which is based on covalent interactions with the ligands and demonstrates that metal K-pre-edge intensities may be used as a measure of ligand-metal covalency in molecular Ti(IV) systems in noncentrosymmetric environments. C1 Stanford Univ, Stanford Synchrotron Radiat Lab, SLAC, Stanford, CA 94309 USA. ExxonMobil Chem Co, Baytown Polymer Ctr, Baytown, TX 77522 USA. Stanford Univ, Dept Chem, Stanford, CA 94309 USA. RP George, SD (reprint author), Stanford Univ, Stanford Synchrotron Radiat Lab, SLAC, Stanford, CA 94309 USA. EM serena@slac.stanford; Edward.Solomon@Stanford.edu RI DeBeer, Serena/G-6718-2012 NR 48 TC 54 Z9 54 U1 1 U2 26 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 JAN 19 PY 2005 VL 127 IS 2 BP 667 EP 674 DI 10.1021/ja044827v PG 8 WC Chemistry, Multidisciplinary SC Chemistry GA 887RZ UT WOS:000226324500049 PM 15643891 ER PT J AU Da Re, RE Jantunen, KC Golden, JT Kiplinger, JL Morris, DE AF Da Re, RE Jantunen, KC Golden, JT Kiplinger, JL Morris, DE TI Molecular spectroscopy of uranium(IV) bis(ketimido) complexes. Rare observation of resonance-enhanced Raman scattering from organoactinide complexes and evidence for broken-symmetry excited states SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Article ID ELECTRONIC-STRUCTURE; URANOCENE; SPECTRA; IMIDO AB Electronic absorption and resonance-enhanced Raman spectra for ketimido (azavinylidene) complexes of tetravalent uranium, (C5Me5)(2)U[-N=C(Ph)(R)](2) (R = Ph, Me, and CH2Ph), have been recorded. The absorption spectra exhibit four broad bands between 13 000 and 24 000 cm(-1). The highest-energy band is assigned to the ketimido-localized p(perpendicular to)(N)-->pi*(N=C) transition based on comparison to the spectra of (C5H5)(2)Zr[-N=CPh2](2) and (C5Me5)(2)Th[-N=CPh2](2). Upon excitation into any of these four absorption bands, the (C5Me5)2U[-N=C(Ph)(R)](2) complexes exhibit resonance enhancement for several Raman bands attributable to vibrations of the ketimido ligands. Raman bands for both the symmetric and nominally asymmetric N=C stretching bands are resonantly enhanced upon excitation into the p(perpendicular to)(N)-->pi*-(N=C) absorption bands, indicating that the excited state is localized on a single ketimido ligand. Raman excitation profiles for (C5Me5)2U[-N=CPh2]2 confirm that at least one of the lower-energy electronic absorption bands (E-max similar to 16300 cm(-1)) is a charge-transfer transition between the U(IV) center and the ketimido ligand(s). The observations of both charge-transfer transitions and resonance enhancement of Raman vibrational bands are exceedingly rare for tetravalent actinide complexes and reflect the strong bonding interactions between the uranium 5f/6d orbitals and those on the ketimido ligands. C1 Los Alamos Natl Lab, Div Chem, Los Alamos, NM 87545 USA. Los Alamos Natl Lab, Glenn T Seaborg Inst Transactinium Sci, Los Alamos, NM 87545 USA. RP Kiplinger, JL (reprint author), Los Alamos Natl Lab, Div Chem, Los Alamos, NM 87545 USA. EM kiplinger@lanl.gov; demorris@lanl.gov RI Morris, David/A-8577-2012; Kiplinger, Jaqueline/B-9158-2011 OI Kiplinger, Jaqueline/0000-0003-0512-7062 NR 25 TC 34 Z9 34 U1 2 U2 12 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 JAN 19 PY 2005 VL 127 IS 2 BP 682 EP 689 DI 10.1021/ja044315g PG 8 WC Chemistry, Multidisciplinary SC Chemistry GA 887RZ UT WOS:000226324500051 PM 15643893 ER PT J AU Haranczyk, M Gutowski, M AF Haranczyk, M Gutowski, M TI Valence and dipole-bound anions of the most stable tautomers of guanine SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Article ID ELECTRON-SPIN-RESONANCE; THEORETICAL AB-INITIO; DOUBLE-RYDBERG ANIONS; NUCLEIC-ACID BASES; ULTRAVIOLET SPECTROSCOPY; IONIZATION-POTENTIALS; AQUEOUS-SOLUTION; GAS-PHASE; DNA; ENERGY AB Anionic states of guanine, which is the only nucleic acid base of which the anions have not yea, been studied in either photoelectron spectroscopic (PES) or Rydberg electron transfer (RET) experiments. have been characterized for the four most stable tautomers; of neutral guanine using a broad spectrum of electronic structure methods from the density functional theory, with the B3LYP exchange-correlation functional, to the coupled-cluster method, with single, double, and perturbative triple excitations. Both valence and dipole-bound anionic states were addressed. We identified some of the difficulties facing future PES or RET experiments on the anion of guanine. Even it guanine is successfully transferred to the gas phase without thermal decomposition, it is critical to have the canonical amino-oxo (G) and both amino-hydroxy (GH and GHN7H) tautomers in the beam, not only the most stable, a noncanonical, amino-oxo tautomer (GN7H), as the latter does not support an adiabatically bound anionic state. We also suggested a scheme for enrichment of gas-phase guanine with the canonical tautomer, which is not the most stable in the gas phase, but which is of main interest due to its biological relevance. The tautomers G. GN7H, and GHN7H support vertically bound valence anionic states with the CCSD(T) value of vertical detachment energy of +0.58, +0.21, and +0.39 eV, respectively. These anionic states are, however, adiabatically unbound and thus metastable. The vertical electronic stability of these valence anionic states is accompanied by serious "buckling" of the molecular skeleton. The G and GHN7H tautomers support dipole-bound states with the CCSD(T) values of adiabatic electron affinity of 65 and 36 meV. respectively. A contribution from higher-than-second-order correlation terms represents, respectively, 48 and 68% of the total vertical electron detachment energy determined at the CCSD(T) level. C1 Pacific NW Natl Lab, Div Chem Sci, Richland, WA 99352 USA. Univ Gdansk, Dept Chem, PL-80952 Gdansk, Poland. RP Gutowski, M (reprint author), Pacific NW Natl Lab, Div Chem Sci, Richland, WA 99352 USA. EM maciej.gutowski@pnt.gov RI Haranczyk, Maciej/A-6380-2014 OI Haranczyk, Maciej/0000-0001-7146-9568 NR 58 TC 63 Z9 63 U1 0 U2 4 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 JAN 19 PY 2005 VL 127 IS 2 BP 699 EP 706 DI 10.1021/ja046622s PG 8 WC Chemistry, Multidisciplinary SC Chemistry GA 887RZ UT WOS:000226324500053 PM 15643895 ER PT J AU Banerjee, S Hemraj-Benny, T Wong, SS AF Banerjee, S Hemraj-Benny, T Wong, SS TI Covalent surface chemistry of single-walled carbon nanotubes SO ADVANCED MATERIALS LA English DT Review ID SIDEWALL FUNCTIONALIZATION; STRUCTURAL-CHARACTERIZATION; CHROMATOGRAPHIC PURIFICATION; CHEMICAL FUNCTIONALIZATION; 1,3-DIPOLAR CYCLOADDITIONS; WATER-SOLUBILIZATION; ELECTRONIC-STRUCTURE; RAMAN-SPECTROSCOPY; CDSE NANOCRYSTALS; QUANTUM DOTS AB In this review article, we explore covalent chemical strategies for the functionalization of carbon-nanotube surfaces. In recent years, nanotubes have been treated as chemical reagents (be it inorganic or organic) in their own right. Indeed, from their inherent structure, one can view nanotubes as sterically bulky, pi-conjugated ligands, or conversely as electron-deficient alkenes. Hence, herein we seek to understand, from a structural perspective, the breadth and types of reactions single-walled nanotubes (SWNTs) can undergo in solution phase, not only at the ends and defect sites but also along the sidewalls. Controllable chemical functionalization suggests that the unique electronic and mechanical properties of SWNTs can be tailored in a determinable manner. Moreover, prevailing themes in nanotube functionalization have been involved with dissolution of tubes. C1 SUNY Stony Brook, Dept Chem, Stony Brook, NY 11794 USA. Brookhaven Natl Lab, Dept Mat & Chem Sci, Upton, NY 11973 USA. RP Wong, SS (reprint author), SUNY Stony Brook, Dept Chem, Stony Brook, NY 11794 USA. EM sswong@notes.cc.sunysb.edu NR 103 TC 857 Z9 876 U1 53 U2 340 PU WILEY-V C H VERLAG GMBH PI WEINHEIM PA PO BOX 10 11 61, D-69451 WEINHEIM, GERMANY SN 0935-9648 J9 ADV MATER JI Adv. Mater. PD JAN 18 PY 2005 VL 17 IS 1 BP 17 EP 29 DI 10.1002/adma.200401340 PG 13 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 892VU UT WOS:000226678900001 ER PT J AU Shin, YS Wang, CM Exarhos, GL AF Shin, YS Wang, CM Exarhos, GL TI Synthesis of SiC ceramics by the carbothermal reduction of mineralized wood with silica SO ADVANCED MATERIALS LA English DT Article ID HIERARCHICALLY ORDERED CERAMICS; CELLULAR STRUCTURES; FIBERS AB Ordered wood cellular structures are used for the synthesis of hierarchical SiC via mineralization with silica followed by carbothermal reduction in argon. C1 Pacific NW Natl Lab, Richland, WA 99352 USA. RP Shin, YS (reprint author), Pacific NW Natl Lab, 902 Battelle Blvd,POB 999, Richland, WA 99352 USA. EM yongsoon.shin@pnl.gov NR 20 TC 78 Z9 82 U1 4 U2 32 PU WILEY-V C H VERLAG GMBH PI WEINHEIM PA PO BOX 10 11 61, D-69451 WEINHEIM, GERMANY SN 0935-9648 J9 ADV MATER JI Adv. Mater. PD JAN 18 PY 2005 VL 17 IS 1 BP 73 EP + DI 10.1002/adma.200400371 PG 6 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 892VU UT WOS:000226678900012 ER PT J AU Lynn, GW Heller, WT Mayasundari, A Minor, KH Peterson, CB AF Lynn, GW Heller, WT Mayasundari, A Minor, KH Peterson, CB TI A model for the three-dimensional structure of human plasma vitronectin from small-angle scattering measurements SO BIOCHEMISTRY LA English DT Article ID PLASMINOGEN-ACTIVATOR INHIBITOR-1; SOMATOMEDIN-B DOMAIN; PROTEIN-KINASE-A; EXHIBIT SIMILAR AFFINITY; CELL-ADHESION; SELF-ASSOCIATION; BINDING-SITES; S-PROTEIN; CONFORMATIONAL-CHANGE; UROKINASE RECEPTOR AB Small-angle X-ray scattering (SAXS) measurements were used to characterize vitronectin, a circulatory protein found in human plasma that functions in regulating cell adhesion and migration, as well as proteolytic cascades that affect blood coagulation, fibrinolysis, and pericellular proteolysis. SAXS measurements were taken over a 3-fold range of protein concentrations, yielding data that characterize a monodisperse system of particles with an average radius of gyration of 30.3 +/- 0.6 Angstrom and a maximum linear dimension of 110 A. Shape restoration was applied to the data to produce two models of the solution structure of the ligand-free protein. A low-resolution model of the protein was generated that indicates the protein to be roughly peanut-shaped. A better understanding of the domain structure of vitronectin resulted from low-resolution models developed from available high-resolution structures of the domains. These domains include the N-terminal domain that was determined experimentally by NMR [Mayasundari, A., Whittemore. N. A., Setpersu, E. H., and Peterson, C. B. (2004) J. Biol. Chem. 279, 29359-29366] and the docked structure of the central and C-terminal domains that were determined by computational threading [Xu, D., Baburaj, K., Peterson, C. B., and Xu, Y. (2001) Proteins: Struct., Funct., Genet. 44, 312-320]. This model provides an indication of the disposition of the central domain and C-terminal heparin-binding domains of vitronectin with respect to the N-terminal somatomedin B (SMB) domain. This model constructed from the available domain structures, which agrees with the low-resolution model produced from the SAXS data, shows the SMB domain well separated from the central and heparin-binding domains by a disordered linker (residues 54-130). Also, binding sites within the SMB domain are predicted to be well exposed to the surrounding solvent for ease of access to its various ligands. C1 Univ Tennessee, Dept Biochem & Cellular & Mol Biol, Knoxville, TN 37996 USA. Univ Tennessee, Ctr Excellence Struct Biol, Knoxville, TN 37996 USA. Oak Ridge Natl Lab, Ctr Struct Mol Biol, Oak Ridge, TN 37831 USA. Oak Ridge Natl Lab, Condensed Matter Sci Div, Oak Ridge, TN 37831 USA. RP Peterson, CB (reprint author), Univ Tennessee, Dept Biochem & Cellular & Mol Biol, Knoxville, TN 37996 USA. EM cynthia_peterson@utk.edu FU NHLBI NIH HHS [HL50676] NR 62 TC 30 Z9 31 U1 4 U2 11 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0006-2960 J9 BIOCHEMISTRY-US JI Biochemistry PD JAN 18 PY 2005 VL 44 IS 2 BP 565 EP 574 DI 10.1021/bi048347s PG 10 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA 888BA UT WOS:000226348000014 PM 15641781 ER PT J AU Zhang, P Smith, S Rumbles, G Himmel, ME AF Zhang, P Smith, S Rumbles, G Himmel, ME TI Direct imaging of surface-enhanced Raman scattering in the near field SO LANGMUIR LA English DT Article ID OPTICAL-PROPERTIES; COLLOID CLUSTERS; SPECTROSCOPY; LOCALIZATION; EXCITATIONS; MICROSCOPY; MOLECULES; FILMS AB By using near-field scanning microscopy/spectroscopy, we show that surface-enhanced Raman scattering (SERS) of rhodamine 6G deposited on self-affine silver colloidal film is localized to small, down to less than 200 nm, portions of the film. The locus of the SERS signals ("hot spots") does not necessarily reside in special topographic elements such as interstices and between nanoparticles. The local SERS enhancement is estimated to be over 3 orders of magnitude higher compared to the far-field measurements. Near-field imaging of SERS directly validates the theory of the optical response of self-affine fractal objects. C1 Natl Renewable Energy Lab, Ctr Basic Sci, Golden, CO 80401 USA. Natl Renewable Energy Lab, Natl Bioenergy Ctr, Golden, CO 80401 USA. RP Zhang, P (reprint author), New Mexico Inst Min & Technol, Dept Chem, Socorro, NM 87801 USA. EM pzhang@nmt.edu; ssmith@nrel.gov OI Rumbles, Garry/0000-0003-0776-1462 NR 20 TC 29 Z9 29 U1 1 U2 6 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0743-7463 J9 LANGMUIR JI Langmuir PD JAN 18 PY 2005 VL 21 IS 2 BP 520 EP 523 DI 10.1021/la048037a PG 4 WC Chemistry, Multidisciplinary; Chemistry, Physical; Materials Science, Multidisciplinary SC Chemistry; Materials Science GA 887ZD UT WOS:000226343100006 PM 15641817 ER PT J AU Sims, GE Choi, IG Kim, SH AF Sims, GE Choi, IG Kim, SH TI Protein conformational space in higher order phi-psi maps SO PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA LA English DT Article DE global peptide conformational mapping multidimensional scaling; Ramachandran map; global mapping ID REPRESENTATIONS; PATHWAYS AB We have mapped protein conformational space from two to seven residue lengths by employing multidimensional scaling on a data matrix composed of pair-wise angular distances for multiple phi-Psi values collected from high-resolution protein structures. The resulting global maps show clustering of peptide conformations that reveals a dramatic reduction of conformational space as sampled by experimentally observed pepticles. Each map can be viewed as a higher order phi-Psi plot defining regions of space that are conformationally allowed. C1 Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. Univ Calif Berkeley, Biophys Grad Grp, Berkeley, CA 94720 USA. Lawrence Berkeley Natl Lab, Berkeley Struct Genom Ctr, Berkeley, CA 94720 USA. RP Kim, SH (reprint author), Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. EM shkim@cchem.berkeley.edu RI Choi, In-Geol/F-3152-2013 FU NHGRI NIH HHS [HG-0004705]; NIGMS NIH HHS [P50 GM062412, GM-62412, GM-0829515] NR 16 TC 27 Z9 28 U1 1 U2 5 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 JAN 18 PY 2005 VL 102 IS 3 BP 618 EP 621 DI 10.1073/pnas.0408746102 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 889IF UT WOS:000226436000019 PM 15640351 ER PT J AU Keys, DN Lee, BI Di Gregorio, A Harafuji, N Detter, JC Wang, M Kahsai, O Ahn, S Zhang, C Doyle, SA Satoh, N Satou, Y Saiga, H Christian, AT Rokhsar, DS Hawkins, TL Levine, M Richardson, PM AF Keys, DN Lee, BI Di Gregorio, A Harafuji, N Detter, JC Wang, M Kahsai, O Ahn, S Zhang, C Doyle, SA Satoh, N Satou, Y Saiga, H Christian, AT Rokhsar, DS Hawkins, TL Levine, M Richardson, PM TI A saturation screen for cis-acting regulatory DNA in the Hox genes of Ciona intestinalis SO PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA LA English DT Article DE cis-regulation; hox cluster; ascidian ID NERVOUS-SYSTEM; EXPRESSION; SEQUENCE; EVOLUTION; CHORDATE; IDENTIFICATION; COLINEARITY; DROSOPHILA; JUVENILE; ORIGINS AB A screen for the systematic identification of cis-regulatory elements within large (> 100 kb) genomic domains containing Hox genes was performed by using the basal chordate Ciona intestinalis. Randomly generated DNA fragments from bacterial artificial chromosomes containing two clusters of Hox genes were inserted into a vector upstream of a minimal promoter and lacZ reporter gene. A total of 222 resultant fusion genes were separately electroporated into fertilized eggs, and their regulatory activities were monitored in larvae. In sum, 21 separable cis-regulatory elements were found. These include eight Hox linked domains that drive expression in nested anterior-posterior domains of ectodermally derived tissues. In addition to vertebrate-like CNS regulation, the discovery of cis-regulatory domains that drive epidermal transcription suggests that C. intestinalis has arthropod-like Hox patterning in the epidermis. C1 US DOE, Joint Genome Inst, Walnut Creek, CA USA. Cornell Univ, Weill Med Coll, Dept Cell & Dev Biol, New York, NY 10021 USA. Univ Calif Berkeley, Dept Mol & Cell Biol, Div Genet & Dev, Berkeley, CA 94720 USA. Kyoto Univ, Grad Sch Sci, Dept Zool, Sakyo Ku, Kyoto 6068502, Japan. Tokyo Metropolitan Univ, Dept Biol Sci, Hachioji, Tokyo 1920397, Japan. Lawrence Livermore Natl Lab, Biol & Biotechnol Res Program, Livermore, CA 94551 USA. RP Richardson, PM (reprint author), US DOE, Joint Genome Inst, Walnut Creek, CA USA. EM pmrichardson@lbl.gov RI Satoh, Nori/C-4123-2009; Di Gregorio, Anna/C-4766-2008; Satou, Yutaka/K-7131-2012 OI Satou, Yutaka/0000-0001-5193-0708 NR 32 TC 19 Z9 20 U1 1 U2 2 PU NATL ACAD SCIENCES PI WASHINGTON PA 2101 CONSTITUTION AVE NW, WASHINGTON, DC 20418 USA SN 0027-8424 J9 P NATL ACAD SCI USA JI Proc. Natl. Acad. Sci. U. S. A. PD JAN 18 PY 2005 VL 102 IS 3 BP 679 EP 683 DI 10.1073/pnas.0408952102 PG 5 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 889IF UT WOS:000226436000030 PM 15647365 ER PT J AU Mack, GH Cole, DR AF Mack, GH Cole, DR TI Geochemical model of delta O-18 of pedogenic calcite versus latitude and its application to Cretaceous palaeoclimate SO SEDIMENTARY GEOLOGY LA English DT Article DE palaeosols; palaeoclimate; oxygen isotopes; cretaceous ID CENTRAL NEW-MEXICO; OXYGEN ISOTOPES; SOIL CARBONATES; FORELAND-BASIN; STABLE CARBON; PALEOSOLS; HISTORY; CLIMATE; UTAH; INDICATORS AB In the absence of a systematic, global data base on the delta(18)O composition of modem soil calcite, predicted isotopic values are calculated as a function of latitude between 60degrees and 20degrees, using delta(18)O of summer and winter meteoric water, ambient soil temperature equal to either measured values in Asia or mean annual temperature, and 0%, 10%, 20% and 30% evaporation of soil water. The results show overall higher isotopic values for summer versus winter precipitation, but steeper, positive slopes for the winter-precipitation curves. Where soil temperature is equated to mean annual temperature, the summer-precipitation curves are nearly flat at high latitudes and have a negative slope at low latitudes. In all cases, the delta(18)O values increase with increasing percent evaporation of soil water. Oxygen isotopic data for Early (Aptian) and Late (Maastrichtian) Cretaceous palaeosol calcite as a function of palaeolatitude of the Western Interior of North America plot in the modem winter-precipitation field, which, along with vertic features, may suggest a winter-wet palaeoclimate. Steeper, positive slopes for the Cretaceous curves compared to the modem curves may be attributable to greater latitudinal gradients in mean annual temperature and soil temperature in the Cretaceous compared to today, and/or to a greater degree of evaporation in Cretaceous soils at low latitudes compared to the modem earth. Distinguishing between these possibilities will require a more complete understanding of the variables that affect oxygen isotopes in pedogenic calcite, as well as better Cretaceous terrestrial palaeoclimate proxies with which to compare the isotopic data. (C) 2004 Elsevier B.V. All rights reserved. C1 New Mexico State Univ, Coll Arts & Sci, Dept Geol Sci, Las Cruces, NM 88003 USA. Oak Ridge Natl Lab, Div Chem Sci, Oak Ridge, TN 37831 USA. RP Mack, GH (reprint author), New Mexico State Univ, Coll Arts & Sci, Dept Geol Sci, Box 3AB, Las Cruces, NM 88003 USA. EM gmack@nmsu.edu NR 40 TC 11 Z9 12 U1 0 U2 5 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0037-0738 J9 SEDIMENT GEOL JI Sediment. Geol. PD JAN 18 PY 2005 VL 174 IS 1-2 BP 115 EP 122 DI 10.1016/j.sedgeo.2004.12.002 PG 8 WC Geology SC Geology GA 902RQ UT WOS:000227374600005 ER PT J AU Berryman, JG AF Berryman, JG TI Thermal conductivity of porous media SO APPLIED PHYSICS LETTERS LA English DT Article ID COMPLEX DIELECTRIC-CONSTANT; 2-COMPONENT COMPOSITE-MATERIAL; VARIATIONAL BOUNDS; RIGOROUS BOUNDS; PERMITTIVITY; TRANSPORT; ROCKS; MODEL AB An analytical formulation of Bergman-Milton conductivity bounds is used in a different way to obtain rigorous bounds on the real thermal conductivity of a fluid-saturated porous material. These bounds do not depend explicitly on the porosity, but rather on two formation factors-one associated with the pore space and the other with the solid frame. (C) 2005 American Institute of Physics. C1 Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. RP Berryman, JG (reprint author), Lawrence Livermore Natl Lab, POB 808 L-200, Livermore, CA 94551 USA. EM berryman1@llnl.gov RI Berryman, James/A-9712-2008 NR 18 TC 13 Z9 13 U1 5 U2 11 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 JAN 17 PY 2005 VL 86 IS 3 AR 032905 DI 10.1063/1.1852718 PG 3 WC Physics, Applied SC Physics GA 895LO UT WOS:000226864600060 ER PT J AU Chen, P Chu, PK Hochbauer, T Lee, JK Nastasi, M Buca, D Mantl, S Loo, R Caymax, M Alford, T Mayer, JW Theodore, ND Cai, M Schmidt, B Lau, SS AF Chen, P Chu, PK Hochbauer, T Lee, JK Nastasi, M Buca, D Mantl, S Loo, R Caymax, M Alford, T Mayer, JW Theodore, ND Cai, M Schmidt, B Lau, SS TI Investigation of plasma hydrogenation and trapping mechanism for layer transfer SO APPLIED PHYSICS LETTERS LA English DT Article ID SILICON-ON-INSULATOR; IMPLANTED SI; NUCLEATION; DEFECTS; BORON AB Hydrogen ion implantation is conventionally used to initiate the transfer of Si thin layers onto Si wafers coated with thermal oxide. In this work, we studied the feasibility of using plasma hydrogenation to replace high dose H implantation for layer transfer. Boron ion implantation was used to introduce H-trapping centers into Si wafers to illustrate the idea. Instead of the widely recognized interactions between boron and hydrogen atoms, this study showed that lattice damage, i.e., dangling bonds, traps H atoms and can lead to surface blistering during hydrogenation or upon postannealing at higher temperature. The B implantation and subsequent processes control the uniformity of H trapping and the trap depths. While the trap centers were introduced by B implantation in this study, there are many other means to do the same without implantation. Our results suggest an innovative way to achieve high quality transfer of Si layers without H implantation at high energies and high doses. (C) 2005 American Institute of Physics. C1 City Univ Hong Kong, Dept Phys & Mat Sci, Kowloon, Hong Kong, Peoples R China. Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Forschungszentrum Julich, Inst Schicht & Ionentech, D-52425 Julich, Germany. IMEC, B-3001 Louvain, Belgium. Arizona State Univ, Dept Chem & Mat Engn, Tempe, AZ 85287 USA. Motorola Inc, Adv Prod Res & Dev Lab, Tempe, AZ 85284 USA. Univ Calif San Diego, San Diego, CA 92093 USA. RP City Univ Hong Kong, Dept Phys & Mat Sci, Tat Chee Ave, Kowloon, Hong Kong, Peoples R China. EM paul.chu@cityu.edu.hk RI Chen, Peng/H-3384-2012; Chu, Paul/B-5923-2013; Mantl, Siegfried/L-1317-2013; Buca, Dan/K-3373-2013; Loo, Roger/F-8392-2010 OI Chu, Paul/0000-0002-5581-4883; Mantl, Siegfried/0000-0002-4266-0619; Buca, Dan/0000-0002-3692-5596; NR 15 TC 26 Z9 26 U1 0 U2 4 PU AMER INST PHYSICS PI MELVILLE PA 1305 WALT WHITMAN RD, STE 300, MELVILLE, NY 11747-4501 USA SN 0003-6951 EI 1077-3118 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD JAN 17 PY 2005 VL 86 IS 3 AR 031904 DI 10.1063/1.1852087 PG 3 WC Physics, Applied SC Physics GA 895LO UT WOS:000226864600016 ER PT J AU Eah, SK Jaeger, HM Scherer, NF Wiederrecht, GP Lin, XM AF Eah, SK Jaeger, HM Scherer, NF Wiederrecht, GP Lin, XM TI Plasmon scattering from a single gold nanoparticle collected through an optical fiber SO APPLIED PHYSICS LETTERS LA English DT Article ID METALLIC NANOPARTICLES; SILVER NANOPARTICLES; SPECTROSCOPY; MICROSCOPY; RESONANCE AB A single gold nanoparticle is attached to the end of a chemically etched fiber axicon microlens tip by modifying the tip surface with linker molecules. The high collection efficiency of the fiber axicon microlens allows plasmon scattering of a single nanoparticle to be measured directly through the optical fiber. The portable nature of this probe allows direct optical sensing of environmental changes using a single nanoparticle. (C) 2005 American Institute of Physics. [DOI: 10.1063/1.1851011] C1 Argonne Natl Lab, Div Chem, Div Mat Sci, Argonne, IL 60439 USA. Argonne Natl Lab, Ctr Nanoscale Mat, Argonne, IL 60439 USA. Univ Chicago, James Franck Inst, Chicago, IL 60637 USA. Univ Chicago, Dept Phys, Chicago, IL 60637 USA. Univ Chicago, Dept Chem, Chicago, IL 60637 USA. RP Argonne Natl Lab, Div Chem, Div Mat Sci, Argonne, IL 60439 USA. EM wiederrecht@anl.gov; xmlin@anl.gov RI Eah, Sang-Kee/E-2343-2012 NR 16 TC 37 Z9 37 U1 0 U2 18 PU AMER INST PHYSICS PI MELVILLE PA 1305 WALT WHITMAN RD, STE 300, MELVILLE, NY 11747-4501 USA SN 0003-6951 EI 1077-3118 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD JAN 17 PY 2005 VL 86 IS 3 AR 031902 DI 10.1063/1.1851011 PG 3 WC Physics, Applied SC Physics GA 895LO UT WOS:000226864600014 ER PT J AU Feng, J Ding, SY Tucker, MP Himmel, ME Kim, YH Zhang, SB Keyes, BM Rumbles, G AF Feng, J Ding, SY Tucker, MP Himmel, ME Kim, YH Zhang, SB Keyes, BM Rumbles, G TI Cyclodextrin driven hydrophobic/hydrophilic transformation of semiconductor nanoparticles SO APPLIED PHYSICS LETTERS LA English DT Article ID QUANTUM DOTS; PROTEIN AB Quantum dots (QDs) have been the subject of considerable study in theoretical physics, and water soluble QDs now appear to have numerous applications in biological tagging, molecular electronic devices, and nanoscale engineering. The work reported here supports the notion that the aliphatic chains of the trioctylphosphine oxide molecules decorating these (CdSe)ZnS core-shell QDs are stabilized by the hydrophobic cyclodextrin (CD) lumen. Photoluminescence studies show a redshift of over 15 nm in the emission wavelength of the QDs upon complexation with the CD, and first-principles calculations reveal an exothermic exchange of the S in the ZnS shell with the CD hydroxyl oxygen. Unlike simple water-driven surface transformations, the directed bonding of hydroxyl groups to the ZnS shell results in stable structures, verified by photoluminescence and Fourier transform infrared spectroscopy. (C) 2005 American Institute of Physics. C1 Natl Renewable Energy Lab, Natl Bioenergy Ctr, Golden, CO 80401 USA. Natl Renewable Energy Lab, Basic Sci Ctr, Golden, CO 80401 USA. RP Natl Renewable Energy Lab, Natl Bioenergy Ctr, Golden, CO 80401 USA. EM mike_himmel@nrel.gov RI Kim, Yong-Hyun/C-2045-2011; Krausnick, Jennifer/D-6291-2013; Zhang, Shengbai/D-4885-2013; Ding, Shi-You/O-1209-2013 OI Kim, Yong-Hyun/0000-0003-4255-2068; Zhang, Shengbai/0000-0003-0833-5860; NR 15 TC 17 Z9 17 U1 1 U2 5 PU AMER INST PHYSICS PI MELVILLE PA 1305 WALT WHITMAN RD, STE 300, MELVILLE, NY 11747-4501 USA SN 0003-6951 EI 1077-3118 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD JAN 17 PY 2005 VL 86 IS 3 AR 033108 DI 10.1063/1.1854739 PG 3 WC Physics, Applied SC Physics GA 895LO UT WOS:000226864600073 ER PT J AU Lee, M Wanke, MC Reno, JL AF Lee, M Wanke, MC Reno, JL TI Millimeter wave mixing using plasmon and bolometric response in a double-quantum-well field-effect transistor SO APPLIED PHYSICS LETTERS LA English DT Article ID 2-DIMENSIONAL ELECTRON-GAS; TERAHERTZ RADIATION; MOBILITY TRANSISTORS; RESONANT DETECTION; MIXER; SUBTERAHERTZ; MODES AB Heterodyne mixing characteristics of a double-quantum-well field-effect transistor (DQW FET) from 94 to 145 GHz are reported. The DQW FET exhibits two physically distinct mixing responses. Near pinch-off, the device behaves as a broadband bolometric mixer with intermediate frequency (IF) bandwidth of 620 MHz. Away from pinch-off it shows an electrically tunable resonant plasmon response. Mixing on a plasmon resonance yields an IF with significant harmonic distortion, signaling a complicated nonlinear mechanism, and shows a wide IF bandwidth >2 GHz. (C) 2005 American Institute of Physics. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Lee, M (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. EM mleel@sandia.gov NR 16 TC 54 Z9 55 U1 1 U2 9 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD JAN 17 PY 2005 VL 86 IS 3 AR 033501 DI 10.1063/1.1851606 PG 3 WC Physics, Applied SC Physics GA 895LO UT WOS:000226864600080 ER PT J AU MacManus-Driscoll, JL Foltyn, SR Maiorov, B Jia, QX Wang, H Serquis, A Civale, L Lin, Y Hawley, ME Maley, MP Peterson, DE AF MacManus-Driscoll, JL Foltyn, SR Maiorov, B Jia, QX Wang, H Serquis, A Civale, L Lin, Y Hawley, ME Maley, MP Peterson, DE TI Rare earth ion size effects and enhanced critical current densities in Y2/3Sm1/3Ba2Cu3O7-x coated conductors SO APPLIED PHYSICS LETTERS LA English DT Article ID THIN-FILMS; PHASE-STABILITY; BARIUM CUPRATE; DEPOSITION AB The influence of rare earth (RE) ion size on critical current density (J(c)) in epitaxial films of superconducting REBa2CuO7-x was studied, where RE is the mixture of two or three rare earth ions. No systematic dependence of Jc on RE ion size was found. However, strongly enhanced critical current densities (J(c)'s) were found for the composition Y2/3SM1/3Ba2Cu3O7-x (YSmBCO). In similar to1-mum-thick films, J(c)'s as high as 4.7X 10(6) A cm(-2) (7.5.5 K, 0 T) and 1 X 10(4) A cm(-2) (75.5 K, 5 T) were obtained on single crystals and 6 X 104 A cm(-2) (75.5 K, 5 T) on buffered metal. The values are up to a factor of 3 higher than for comparative YBCO samples. (C) 2005 American Institute of Physics. C1 Los Alamos Natl Lab, Superconductiv Technol Ctr, Los Alamos, NM 87545 USA. Univ Cambridge, Dept Mat Sci & Met, Cambridge CB2 3QZ, England. RP MacManus-Driscoll, JL (reprint author), Los Alamos Natl Lab, Superconductiv Technol Ctr, Los Alamos, NM 87545 USA. EM jld35@cam.ac.uk RI Jia, Q. X./C-5194-2008; Wang, Haiyan/P-3550-2014; Serquis, Adriana/L-6554-2015; lin, yuan/B-9955-2013; OI Wang, Haiyan/0000-0002-7397-1209; Serquis, Adriana/0000-0003-1499-4782; Maiorov, Boris/0000-0003-1885-0436 NR 13 TC 38 Z9 38 U1 0 U2 5 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 JAN 17 PY 2005 VL 86 IS 3 AR 032505 DI 10.1063/1.1851006 PG 3 WC Physics, Applied SC Physics GA 895LO UT WOS:000226864600047 ER PT J AU Xi, Y Xi, JQ Gessmann, T Shah, JM Kim, JK Schubert, EF Fischer, AJ Crawford, MH Bogart, KHA Allerman, AA AF Xi, Y Xi, JQ Gessmann, T Shah, JM Kim, JK Schubert, EF Fischer, AJ Crawford, MH Bogart, KHA Allerman, AA TI Junction and carrier temperature measurements in deep-ultraviolet light-emitting diodes using three different methods SO APPLIED PHYSICS LETTERS LA English DT Article ID LASERS AB The junction temperature of AlGaN ultraviolet light-emitting diodes emitting at 295 nm is measured by using the temperature coefficients of the diode forward voltage and emission peak energy. The high-energy slope of the spectrum is explored to measure the carrier temperature. A linear relation between junction temperature and current is found. Analysis of the experimental methods reveals that the diode-forward voltage is the most accurate (+/- 3 degreesC). A theoretical model for the dependence of the diode forward voltage (V-f) on junction temperature (T-j) is developed that takes into account the temperature dependence of the energy gap. A thermal resistance of 87.6 K/W is obtained with the device mounted with thermal paste on a heat sink. (C) 2005 American Institute of Physics. C1 Rensselaer Polytech Inst, Dept Elect Comp & Syst Engn, Troy, NY 12180 USA. Rensselaer Polytech Inst, Dept Phys Appl Phys & Astron, Troy, NY 12180 USA. Sandia Natl Labs, Compound Semicond Res Lab, Albuquerque, NM 87185 USA. RP Xi, Y (reprint author), Rensselaer Polytech Inst, Dept Elect Comp & Syst Engn, Troy, NY 12180 USA. EM efschubert@rpi.edu NR 14 TC 116 Z9 122 U1 2 U2 29 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 JAN 17 PY 2005 VL 86 IS 3 AR 031907 DI 10.1063/1.1849838 PG 3 WC Physics, Applied SC Physics GA 895LO UT WOS:000226864600019 ER PT J AU Bigelow, DJ Squier, TC AF Bigelow, DJ Squier, TC TI Redox modulation of cellular signaling and metabolism through reversible oxidation of methionine sensors in calcium regulatory proteins SO BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS LA English DT Review DE methionine oxidation; calmodulin; signal transduction; calcium regulation; methionine sulfoxide reductase; cellular metabolism ID MEMBRANE CA-ATPASE; CARDIAC SARCOPLASMIC-RETICULUM; CALMODULIN-DEPENDENT ACTIVATION; SKELETAL-MUSCLE; NITRIC-OXIDE; SULFOXIDE REDUCTASE; TYROSINE NITRATION; OXIDIZED CALMODULIN; AMINO-ACIDS; FUNCTIONAL ASSOCIATION AB Adaptive responses associated with environmental stressors are critical to cell survival. Under conditions when cellular redox and antioxidant defenses are overwhelmed, the selective oxidation of critical methionines within selected protein sensors functions to downregulate energy metabolism and the further generation of reactive oxygen species (ROS). Mechanistically, these functional changes within protein sensors take advantage of the helix-breaking character of methionine sulfoxide. The sensitivity of several calcium regulatory proteins to oxidative modification provides cellular sensors that link oxidative stress to cellular response and recovery. Calmodulin (CaM) is one such critical calcium regulatory protein, which is functionally sensitive to methionine oxidation. Helix destabilization resulting from the oxidation of either Met(144) or Met(145) results in the nonproductive association between CaM and target proteins. The ability of oxidized CaM to stabilize its target proteins in an inhibited state with an affinity similar to that of native (unoxidized) CaM permits this central regulatory protein to function as a cellular rheostat that down-regulates energy metabolism in response to oxidative stress. Likewise, oxidation of a methionine within a critical switch region of the regulatory protein phospholamban is expected to destabilize the phosphorylation-dependent helix formation necessary for the release of enzyme inhibition, resulting in a down-regulation of the Ca-ATPase in response to beta-adrenergic signaling in the heart. We suggest that under acute conditions, such as inflammation or ischemia, these types of mechanisms ensure minimal nonspecific cellular damage, allowing for rapid restoration of cellular function through repair of oxidized methionines by methionine sulfoxide reductases and degradation pathways after restoration of normal cellular redox conditions. (C) 2004 Published by Elsevier B.V. C1 Pacific NW Natl Lab, Fundamental Sci Directorate, Cel Biol & Biochem Grp, Richland, WA 99352 USA. Pacific NW Natl Lab, Fundamental Sci Directorate, Div Biol Sci, Richland, WA 99352 USA. RP Squier, TC (reprint author), Pacific NW Natl Lab, Fundamental Sci Directorate, Cel Biol & Biochem Grp, POB 999, Richland, WA 99352 USA. EM thomas.squier@pnl.gov FU NIA NIH HHS [AG18013, AG17996, AG12993] NR 116 TC 117 Z9 122 U1 4 U2 17 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 1570-9639 J9 BBA-PROTEINS PROTEOM JI BBA-Proteins Proteomics PD JAN 17 PY 2005 VL 1703 IS 2 BP 121 EP 134 DI 10.1016/j.bbapap.2004.09.012 PG 14 WC Biochemistry & Molecular Biology; Biophysics SC Biochemistry & Molecular Biology; Biophysics GA 899GE UT WOS:000227132100004 PM 15680220 ER PT J AU Nix, DA Eisen, MB AF Nix, DA Eisen, MB TI GATA: a graphic alignment tool for comparative sequence analysis SO BMC BIOINFORMATICS LA English DT Article ID MULTIPLE ALIGNMENT; VISUALIZATION; EVOLUTION; GENOME; DROSOPHILA; DNA AB Background: Several problems exist with current methods used to align DNA sequences for comparative sequence analysis. Most dynamic programming algorithms assume that conserved sequence elements are collinear. This assumption appears valid when comparing orthologous protein coding sequences. Functional constraints on proteins provide strong selective pressure against sequence inversions, and minimize sequence duplications and feature shuffling. For non-coding sequences this collinearity assumption is often invalid. For example, enhancers contain clusters of transcription factor binding sites that change in number, orientation, and spacing during evolution yet the enhancer retains its activity. Dot plot analysis is often used to estimate non-coding sequence relatedness. Yet dot plots do not actually align sequences and thus cannot account well for base insertions or deletions. Moreover, they lack an adequate statistical framework for comparing sequence relatedness and are limited to pairwise comparisons. Lastly, dot plots and dynamic programming text outputs fail to provide an intuitive means for visualizing DNA alignments. Results: To address some of these issues, we created a stand alone, platform independent, graphic alignment tool for comparative sequence analysis ( GATA http:// gata. sourceforge. net/). GATA uses the NCBI-BLASTN program and extensive post-processing to identify all small sub-alignments above a low cut-off score. These are graphed as two shaded boxes, one for each sequence, connected by a line using the coordinate system of their parent sequence. Shading and colour are used to indicate score and orientation. A variety of options exist for querying, modifying and retrieving conserved sequence elements. Extensive gene annotation can be added to both sequences using a standardized General Feature Format ( GFF) file. Conclusions: GATA uses the NCBI-BLASTN program in conjunction with post-processing to exhaustively align two DNA sequences. It provides researchers with a fine-grained alignment and visualization tool aptly suited for non- coding, 0 - 200 kb, pairwise, sequence analysis. It functions independent of sequence feature ordering or orientation, and readily visualizes both large and small sequence inversions, duplications, and segment shuffling. Since the alignment is visual and does not contain gaps, gene annotation can be added to both sequences to create a thoroughly descriptive picture of DNA conservation that is well suited for comparative sequence analysis. C1 Univ Calif Berkeley, Dept Mol & Cell Biol, Berkeley, CA 94720 USA. Lawrence Berkeley Natl Lab, Dept Genome Sci, Div Life Sci, Berkeley, CA 94720 USA. RP Nix, DA (reprint author), Univ Calif Berkeley, Dept Mol & Cell Biol, 229 Stanley Hall, Berkeley, CA 94720 USA. EM danix@lbl.gov; mbeisen@lbl.gov NR 25 TC 40 Z9 42 U1 0 U2 4 PU BIOMED CENTRAL LTD PI LONDON PA MIDDLESEX HOUSE, 34-42 CLEVELAND ST, LONDON W1T 4LB, ENGLAND SN 1471-2105 J9 BMC BIOINFORMATICS JI BMC Bioinformatics PD JAN 17 PY 2005 VL 6 AR 9 DI 10.1186/1471-2105-6-9 PG 8 WC Biochemical Research Methods; Biotechnology & Applied Microbiology; Mathematical & Computational Biology SC Biochemistry & Molecular Biology; Biotechnology & Applied Microbiology; Mathematical & Computational Biology GA 895LS UT WOS:000226865300001 PM 15655071 ER PT J AU Barger, V Chiang, CW Jiang, J Li, TJ AF Barger, V Chiang, CW Jiang, J Li, TJ TI Axion models with high-scale supersymmetry breaking SO NUCLEAR PHYSICS B LA English DT Review ID RENORMALIZATION-GROUP EQUATIONS; STRONG-CP PROBLEM; QUANTUM-FIELD THEORY; DISCRETE GAUGE SYMMETRIES; PARTICLE PHYSICS; COSMOLOGICAL CONSTANT; SUPERSTRING THEORY; GLOBAL SYMMETRIES; YUKAWA COUPLINGS; STANDARD MODEL AB Inspired by the possibility of high-scale supersymmetry breaking in the string landscape where the cosmological constant problem and the gauge hierarchy problem can be solved while the strong CP problem is still a challenge for naturalness, we propose a supersymmetric KSVZ axion model with an approximate universal intermediate-scale (similar to 10(11) GeV) supersymmetry breaking. To protect the global Peccei-Quinn (PQ) symmetry against quantum gravitational violation, we consider the gauged discrete Z(N) PQ symmetry. In our model the axion can be a cold dark matter candidate, and the intermediate supersymmetry breaking scale is directly related to the PQ symmetry breaking scale. Gauge coupling unification can be achieved at about 2.7 x 10(16) GeV. The Higgs mass range is 130 to 160 GeV. We briefly discuss other axion models with high-scale supersymmetry breaking where the stabilization of the axion solution is similar. (C) 2004 Elsevier B.V. All rights reserved. C1 Univ Wisconsin, Dept Phys, Madison, WI 53706 USA. Natl Cent Univ, Dept Phys, Chungli 320, Taiwan. Argonne Natl Lab, Div High Energy Phys, Argonne, IL 60439 USA. Univ Oregon, Inst Theoret Sci, Eugene, OR 97403 USA. Inst Adv Study, Sch Nat Sci, Princeton, NJ 08540 USA. RP Univ Wisconsin, Dept Phys, Madison, WI 53706 USA. EM tli@sns.ias.edu OI Chiang, Cheng-Wei/0000-0003-1716-0169 NR 111 TC 28 Z9 28 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0550-3213 EI 1873-1562 J9 NUCL PHYS B JI Nucl. Phys. B PD JAN 17 PY 2005 VL 705 IS 1-2 BP 71 EP 91 DI 10.1016/j.nuclphysb.2004.11.033 PG 21 WC Physics, Particles & Fields SC Physics GA 889GQ UT WOS:000226431900004 ER PT J AU Phuoc, TX AF Phuoc, TX TI A comparative study of the photon pressure force, the photophoretic force, and the adhesion van der Waals force SO OPTICS COMMUNICATIONS LA English DT Article ID OPTICAL LEVITATION; DIELECTRIC SPHERE; LASER GUIDANCE; PARTICLES; BEAM; REMOVAL; FIBERS AB A comparative study of the photon pressure force, the photophoretic force, and the adhesion van der Waals force acting on particles attached to an optical window was presented. The goal is to explore the use of radiation forces for in situ cleaning of engine optical access windows. Using aluminum, glass, fly ash and soot particles on a glass substrate the calculations show that radiation forces could be several times greater than the van der Waals force and they are very effective for particle removal applications if radiation intensity is above a certain critical level. For soot and fly ash particles, which are typically present in many combustion environments, the photon pressure forces were about 3 times and the photophoretic forces were about 3 orders of magnitude greater than the van der Waals force. (C) 2004 Elsevier B.V. All rights reserved. C1 Natl Energy Technol Lab, Pittsburgh, PA 15236 USA. RP Phuoc, TX (reprint author), Natl Energy Technol Lab, POB 10940,MS 84-340, Pittsburgh, PA 15236 USA. EM Tran@netl.doe.gov NR 21 TC 23 Z9 24 U1 1 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0030-4018 J9 OPT COMMUN JI Opt. Commun. PD JAN 17 PY 2005 VL 245 IS 1-6 BP 27 EP 35 DI 10.1016/j.optcom.2004.10.047 PG 9 WC Optics SC Optics GA 891XM UT WOS:000226614300004 ER PT J AU Lushnikov, PM AF Lushnikov, PM TI Diffusion of optical pulses in dispersion-shifted randomly birefringent optical fibers SO OPTICS COMMUNICATIONS LA English DT Article DE optical communications; fiber optics; randomness; polarization mode dispersion; pulse propagation ID POLARIZATION-MODE DISPERSION; SOLITON; COMPENSATION; PROPAGATION; CONFINEMENT; SYSTEMS AB An effect of polarization-mode dispersion, nonlinearity and random variation of dispersion along an optical fiber on a pulse propagation in a randomly birefringent dispersion-shifted optical fiber with zero average dispersion is studied. An averaged pulse width is shown analytically to diffuse with propagation distance for arbitrary strong pulse amplitude. It is found that optical fiber nonlinearity can not change qualitatively a diffusion of pulse width but can only modify a diffusion law which means that a root mean square pulse width grows at least as a linear function of the propagation distance. (C) 2004 Published by Elsevier B.V. C1 Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. LD Landau Theoret Phys Inst, Moscow 119334, Russia. RP Lushnikov, PM (reprint author), Los Alamos Natl Lab, Div Theoret, MS-B213, Los Alamos, NM 87545 USA. EM lushnikov@cnls.lanl.gov RI Lushnikov, Pavel/I-2304-2013 NR 27 TC 0 Z9 0 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0030-4018 J9 OPT COMMUN JI Opt. Commun. PD JAN 17 PY 2005 VL 245 IS 1-6 BP 187 EP 192 DI 10.1016/j.optcom.2004.10.016 PG 6 WC Optics SC Optics GA 891XM UT WOS:000226614300021 ER PT J AU Flinn, JM Hunter, D Linkous, DH Lanzirotti, A Smith, LN Brightwell, J Jones, BF AF Flinn, JM Hunter, D Linkous, DH Lanzirotti, A Smith, LN Brightwell, J Jones, BF TI Enhanced zinc consumption causes memory deficits and increased brain levels of zinc SO PHYSIOLOGY & BEHAVIOR LA English DT Article DE zinc; cognitive deficits; spatial memory; Morris water maze; drinking water; biometals; synchrotron X-ray fluorescence; brain concentrations of zinc; rats; learning; thigmotaxicity; atlantis platform; working memory ID LONG-TERM POTENTIATION; METHYL-D-ASPARTATE; MORRIS WATER MAZE; ALZHEIMERS-DISEASE; SPATIAL MEMORY; SUPEROXIDE-DISMUTASE; SYNAPTIC PLASTICITY; ZN-65 UPTAKE; RATS; COPPER AB Zinc deficiency has been shown to impair cognitive functioning, but little work has been done on the effects of elevated zinc. This research examined the effect on memory of raising Sprague-Dawley rats on enhanced levels of zinc (10 ppm ZnCO3; 0.153 mm) in the drinking water for periods of 3 or 9 months, both pre- and postnatally. Controls were raised on lab water. Memory was tested in a series of Morris Water Maze (MWM) experiments, and zinc-treated rats were found to have impairments in both reference and working memory. They were significantly slower to find a stationary platform and showed greater thigraotaxicity, a measure of anxiety. On a working memory task, where the platform was moved each day, zinc-treated animals had longer latencies over both trials and days, swam further from the platform, and showed greater thigmotaxicity. On trials using an Atlantis platform, which remained in one place but was lowered on probe trials, the zinc-treated animals had significantly fewer platform crossings, spent less time in the target quadrant, and did not swim as close to the platform position. They had significantly greater latency on nonprobe trials. Microprobe synchrotron X-ray fluorescence (muSXRF) confirmed that brain zinc levels were increased by adding ZnCO3 to the drinking water. These data show that long-term dietary administration of zinc can lead to impairments in cognitive function. (C) 2004 Elsevier Inc. All rights reserved. C1 George Mason Univ, Dept Psychol, Fairfax, VA 22030 USA. Westinghouse Savannah River Co, Aiken, SC USA. Brookhaven Natl Lab, Natl Synchrotron Light Source, Beamline X26A, Upton, NY 11973 USA. Univ Chicago, Consortium Adv Radiat Sources, Chicago, IL 60637 USA. Tulane Univ, Neurosci Program, New Orleans, LA 70118 USA. US Geol Survey, Div Water Resources, Reston, VA 22092 USA. RP Flinn, JM (reprint author), George Mason Univ, Dept Psychol, 4400 Univ Dr,MS-3F5, Fairfax, VA 22030 USA. EM jflinn@gmu.edu OI Smith, Laura/0000-0003-3687-3148 NR 53 TC 48 Z9 50 U1 0 U2 7 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0031-9384 J9 PHYSIOL BEHAV JI Physiol. Behav. PD JAN 17 PY 2005 VL 83 IS 5 BP 793 EP 803 DI 10.1016/j.physbeh.2004.10.009 PG 11 WC Psychology, Biological; Behavioral Sciences SC Psychology; Behavioral Sciences GA 891CE UT WOS:000226558100015 PM 15639165 ER PT J AU Masselon, C Pasa-Tolic, L Tolic, N Anderson, GA Bogdanov, B Vilkov, AN Shen, YF Zhao, R Oian, WJ Lipton, MS Camp, DG Smith, RD AF Masselon, C Pasa-Tolic, L Tolic, N Anderson, GA Bogdanov, B Vilkov, AN Shen, YF Zhao, R Oian, WJ Lipton, MS Camp, DG Smith, RD TI Targeted comparative proteomics by liquid chromatography-tandem Fourier ion cyclotron resonance mass spectrometry SO ANALYTICAL CHEMISTRY LA English DT Article ID QUANTITATIVE-ANALYSIS; PROTEIN EXPRESSION; MIXTURES; IDENTIFICATION; DISSOCIATION; IONIZATION; REDUCTION; ONLINE AB In proteomics, effective methods are needed for identifying the relatively limited subset of proteins displaying significant changes in abundance between two samples. One way to accomplish this task is to target for identification by MS/MS only the "interesting" proteins based on the abundance ratio of isotopically labeled pairs of peptides. We have developed the software and hardware tools for online LC-FTICR MS/MS studies in which a set of initially unidentified peptides from a proteome analysis can be selected for identification based on their distinctive changes in abundance following a "perturbation". We report here the validation of this method using a mixture of standard proteins combined in different ratios after isotopic labeling. We also demonstrate the application of this method to the identification of Shewanella oneiden-sis peptides/proteins exhibiting differential abundance in suboxic versus aerobic cell cultures. 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, MSIN K8-98, Richland, WA 99352 USA. RI Masselon, Christophe/A-2340-2010; Smith, Richard/J-3664-2012 OI Smith, Richard/0000-0002-2381-2349 FU NCI NIH HHS [CA81654, CA86340]; NCRR NIH HHS [P41 RR018522, RR18522] NR 21 TC 39 Z9 40 U1 0 U2 4 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 JAN 15 PY 2005 VL 77 IS 2 BP 400 EP 406 DI 10.1021/ac049043e PG 7 WC Chemistry, Analytical SC Chemistry GA 887PP UT WOS:000226318300006 PM 15649034 ER PT J AU Renzi, RF Stamps, J Horn, BA Ferko, S VanderNoot, VA West, JAA Crocker, R Wiedenman, B Yee, D Fruetel, JA AF Renzi, RF Stamps, J Horn, BA Ferko, S VanderNoot, VA West, JAA Crocker, R Wiedenman, B Yee, D Fruetel, JA TI Hand-held microanalytical instrument for chip-based electrophoretic separations of proteins SO ANALYTICAL CHEMISTRY LA English DT Article ID CAPILLARY-ELECTROPHORESIS; MICROCHIP; DEVICES; SYSTEMS AB The design, fabrication, and demonstration of a hand-held microchip-based analytical instrument for detection and identification of proteins and other biomolecules are reported. The overall system, referred to as muChemLab, has a modular design that provides for reliability and flexibility and that facilitates rapid assembly, fluid and microchip replacement, troubleshooting, and sample analysis. Components include two independent separation modules that incorporate interchangeable fluid cartridges, a 2-cm-square fused-silica microfluidic chip, and a miniature laser-induced fluorescence detection module. A custom O-ring sealed manifold plate connects chip access ports to a fluids cartridge and a syringe injection port and provides sample introduction and world-to-chip interface. Other novel microfluidic connectors include capillary needle fittings for fluidic connection between septum-sealed fluid reservoirs and the manifold housing the chip, enabling rapid chip priming and fluids replacement. Programmable high-voltage power supplies provide bidirectional currents up to 100 muA at 5000 V, enabling real-time current and voltage monitoring and facilitating troubleshooting and methods development. Laser-induced fluorescence detection allows picomolar (10(-11) M) detection sensitivity of fluorescent dyes and nanomolar sensitivity (10(-9) M) for fluorescamine-labeled proteins. Migration time reproducibility was significantly improved when separations were performed under constant current control (0.5-1%) as compared to constant voltage control (2-8%). C1 Sandia Natl Labs, Livermore, CA 94551 USA. RP Fruetel, JA (reprint author), Sandia Natl Labs, Livermore, CA 94551 USA. EM jfruet@sandia.gov NR 18 TC 87 Z9 90 U1 0 U2 29 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 JAN 15 PY 2005 VL 77 IS 2 BP 435 EP 441 DI 10.1021/ac049214f PG 7 WC Chemistry, Analytical SC Chemistry GA 887PP UT WOS:000226318300010 PM 15649038 ER PT J AU Herr, AE Throckmorton, DJ Davenport, AA Singh, AK AF Herr, AE Throckmorton, DJ Davenport, AA Singh, AK TI On-chip native gel electrophoresis-based immunoassays for tetanus antibody and toxin SO ANALYTICAL CHEMISTRY LA English DT Article ID CAPILLARY ZONE ELECTROPHORESIS; INFLUENZAE TYPE-B; POLYACRYLAMIDE-GELS; ANALYSIS SYSTEM; AMINO-ACIDS; MICROCHIPS; SEPARATION; SERUM; DNA; IMMOBILIZATION AB By integrating photopolymerized cross-linked polyacrylamide gels within a microfluidic device, we have developed a microanalytical platform for performing electrophoresis-based immunoassays. The microfluidic immunoassays are performed by gel electrophoretic separation and quantitation of bound and unbound antibody or antigen. To retain biological activity of proteins and maintain intact immune complexes, nondenaturing polyacrylamide gel electrophoresis conditions were investigated. Both direct (noncompetitive) and competitive immunoassay formats are demonstrated in microchips. A direct immunoassay was developed for detection of tetanus antibodies in buffer as well as diluted serum samples. After an off-chip incubation step, the immunoassay was completed in less than 3 min and the sigmoidal dose-response curve spanned an antibody concentration range from 0.17 to 260 nM. The minimum detectable antibody concentration was 0.68 nM. A competitive immunoassay was also developed for tetanus toxin C-fragment by allowing unlabeled and fluorescently labeled tetanus toxin C-fragment compete to bind to a limited fixed concentration of tetanus antibody. The immunoassay technique described in this work shows promise as a component of an integrated microfluidic device amenable to automation and relevant to development of clinical diagnostic devices. C1 Sandia Natl Labs, Livermore, CA 94551 USA. RP Herr, AE (reprint author), Sandia Natl Labs, Livermore, CA 94551 USA. EM aeherr@sandia.gov FU NIDCR NIH HHS [U01DE014961] NR 44 TC 65 Z9 69 U1 0 U2 10 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 JAN 15 PY 2005 VL 77 IS 2 BP 585 EP 590 DI 10.1021/ac0489768 PG 6 WC Chemistry, Analytical SC Chemistry GA 887PP UT WOS:000226318300029 PM 15649057 ER PT J AU Chen, JF Wabuyele, M Chen, HW Patterson, D Hupert, M Shadpour, H Nikitopoulos, D Soper, SA AF Chen, JF Wabuyele, M Chen, HW Patterson, D Hupert, M Shadpour, H Nikitopoulos, D Soper, SA TI Electrokinetically synchronized polymerase chain reaction microchip fabricated in polycarbonate SO ANALYTICAL CHEMISTRY LA English DT Article ID INDUCED FLUORESCENCE DETECTION; PCR AMPLIFICATION; MICROFLUIDIC DEVICES; ELECTROOSMOTIC FLOW; RNA AMPLIFICATION; MULTIPLEX PCR; DNA; ELECTROPHORESIS; CHIP; SYSTEM AB This paper presents a novel method for DNA thermal amplification using the polymerase chain reaction (PCR) in an electrokinetically driven synchronized continuous flow PCR (EDS-CF-PCR) configuration carried out in a microfabricated polycarbonate (PC) chip. The synchronized format allowed patterning a shorter length microchannel for the PCR compared to nonsynchronized continuous flow formats, permitting the use of smaller applied voltages when the flow is driven electrically and also allowed flexibility in selecting the cycle number without having to change the microchip architecture. A home-built temperature control system was developed to precisely configure three isothermal zones on the chip for denaturing (95 degreesC), annealing (55 degreesC), and extension (72 degreesC) within a single-loop channel. DNA templates were introduced into the PCR reactor, which was filled with the PCR cocktail, by electrokinetic injection. The PCR cocktail consisted of low salt concentrations (KC1) to reduce the current in the EDS-CF-PCR device during cycling. To control the EOF in the PC microchannel to minimize dilution effects as the DNA "plug" was shuttled through the temperature zones, Polybrene was used as a dynamic coating, which resulted in reversal of the EOF. The products generated from 15, 27, 35, and 40 EDS-CF-PCR amplification cycles were collected and analyzed using microchip electrophoresis with LIF detection for fragment sizing. The results showed that the EDS-CF-PCR format produced results similar to that of a conventional block thermal cycler with leveling effects observed for amplicon generation after similar to25 cycles. To the best of our knowledge, this is the first report of electrokinetically driven synchronized PCR performed on chip. C1 Louisiana State Univ, Dept Chem, Baton Rouge, LA 70803 USA. Louisiana State Univ, Ctr BioModular Multi Scale Syst, Baton Rouge, LA 70803 USA. Louisiana State Univ, Dept Mech Engn, Baton Rouge, LA 70803 USA. Zhejiang Univ, Dept Chem, Hangzhou 310028, Peoples R China. Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Soper, SA (reprint author), Louisiana State Univ, Dept Chem, Baton Rouge, LA 70803 USA. EM chsope@lsu.edu RI Nikitopoulos, Dimitris/N-7469-2015 FU NHGRI NIH HHS [R01-HG01499]; NIBIB NIH HHS [R24-EB002115] NR 28 TC 71 Z9 73 U1 0 U2 15 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 JAN 15 PY 2005 VL 77 IS 2 BP 658 EP 666 DI 10.1021/ac048758e PG 9 WC Chemistry, Analytical SC Chemistry GA 887PP UT WOS:000226318300040 PM 15649068 ER PT J AU Martin, S Roe, D Faulon, JL AF Martin, S Roe, D Faulon, JL TI Predicting protein-protein interactions using signature products SO BIOINFORMATICS LA English DT Article ID EXTENDED VALENCE SEQUENCES; MOLECULAR DESCRIPTOR; SACCHAROMYCES-CEREVISIAE; INTERACTION MAP; NETWORKS; DATABASE; SYSTEM; YEAST AB Motivation: Proteome-wide prediction of protein-protein interaction is a difficult and important problem in biology. Although there have been recent advances in both experimental and computational methods for predicting protein-protein interactions, we are only beginning to see a confluence of these techniques. In this paper, we describe a very general, high-throughput method for predicting protein-protein interactions. Our method combines a sequence-based description of proteins with experimental information that can be gathered from any type of protein-protein interaction screen. The method uses a novel description of interacting proteins by extending the signature descriptor, which has demonstrated success in predicting peptide/protein binding interactions for individual proteins. This descriptor is extended to protein pairs by taking signature products. The signature product is implemented within a support vector machine classifier as a kernel function. Results: We have applied our method to publicly available yeast, Helicobacter pylori, human and mouse datasets. We used the yeast and H.pylori datasets to verify the predictive ability of our method, achieving from 70 to 80% accuracy rates using 10-fold cross-validation. We used the human and mouse datasets to demonstrate that our method is capable of cross-species prediction. Finally, we reused the yeast dataset to explore the ability of our algorithm to predict domains. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. Biosyst Res, Livermore, CA 94551 USA. Computat Biol, Livermore, CA 94551 USA. RP Martin, S (reprint author), Sandia Natl Labs, 9212,POB 5800,MS 310, Albuquerque, NM 87185 USA. EM smartin@sandia.gov NR 37 TC 174 Z9 183 U1 2 U2 16 PU OXFORD UNIV PRESS PI OXFORD PA GREAT CLARENDON ST, OXFORD OX2 6DP, ENGLAND SN 1367-4803 J9 BIOINFORMATICS JI Bioinformatics PD JAN 15 PY 2005 VL 21 IS 2 BP 218 EP 226 DI 10.1093/bioinformatics/bth483 PG 9 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 887LV UT WOS:000226308500010 PM 15319262 ER PT J AU Yu, D Volponi, J Chhabra, S Brinker, CJ Mulchandani, A Singh, AK AF Yu, D Volponi, J Chhabra, S Brinker, CJ Mulchandani, A Singh, AK TI Aqueous sol-gel encapsulation of genetically engineered Moraxella spp. cells for the detection of organophosphates SO BIOSENSORS & BIOELECTRONICS LA English DT Article DE biosensors; sol-gel; organophosphates; Moraxella; organophosphate hydrolase; acetylcholine esterase ID NERVE AGENTS; ESCHERICHIA-COLI; ENZYME BIOSENSOR; HYDROLASE; BACTERIA; PROTEIN AB An all-aqueous sol-gel method for encapsulation of bacterial cells in porous silicate matrices towards the development of a biosensor is described. The sol-gel encapsulation of cells is achieved at room temperature and neutral pH. Furthermore, use of sodium silicate as precursor avoids generation of alcohol that can be detrimental to cells in contrast to the traditional alkoxide sol-gel encapsulation process. Moraxella spp. cells engineered to express recombinant organophosphorus hydrolase (OPH) on the cell surface were encapsulated and OPH enzymatic activity was measured for paraoxon hydrolysis. Kinetic parameters (K-m and V-max) as well as pH behavior of surface-expressed OPH were determined to evaluate the effect of encapsulation. Cells encapsulated by the sodium silicate method displayed higher activity retention compared to those by the traditional alkoxide process. Time-course studies over a 2-month period indicate that immobilization through the sodium silicate process led to a reduction in activity of similar to5% as compared to similar to30% activity reduction in case of free cells in buffer indicating that immobilization leads to stabilization, a key parameter in biosensor development. (C) 2004 Elsevier B.V. All rights reserved. C1 Sandia Natl Labs, Livermore, CA 94550 USA. Sandia Natl Labs, Albuquerque, NM 87185 USA. Univ Calif Riverside, Dept Chem & Environm Engn, Riverside, CA 92521 USA. RP Singh, AK (reprint author), Sandia Natl Labs, Livermore, CA 94550 USA. EM aksingh@sandia.gov RI Mulchandani, Ashok/B-9692-2016 OI Mulchandani, Ashok/0000-0002-2831-4154 NR 18 TC 54 Z9 56 U1 2 U2 16 PU ELSEVIER ADVANCED TECHNOLOGY PI OXFORD PA OXFORD FULFILLMENT CENTRE THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0956-5663 J9 BIOSENS BIOELECTRON JI Biosens. Bioelectron. PD JAN 15 PY 2005 VL 20 IS 7 BP 1433 EP 1437 DI 10.1016/j.bios.2004.04.022 PG 5 WC Biophysics; Biotechnology & Applied Microbiology; Chemistry, Analytical; Electrochemistry; Nanoscience & Nanotechnology SC Biophysics; Biotechnology & Applied Microbiology; Chemistry; Electrochemistry; Science & Technology - Other Topics GA 887ZN UT WOS:000226344100024 PM 15590300 ER PT J AU Nemecek, ER Hamlin, DK Fisher, DR Krohn, KA Pagel, JM Appelbaum, FR Press, OW Matthews, DC AF Nemecek, ER Hamlin, DK Fisher, DR Krohn, KA Pagel, JM Appelbaum, FR Press, OW Matthews, DC TI Biodistribution of yttrium-90-labeled anti-CD45 antibody in a nonhuman primate model SO CLINICAL CANCER RESEARCH LA English DT Article ID TOTAL-BODY IRRADIATION; ACUTE MYELOID-LEUKEMIA; NON-HODGKINS-LYMPHOMA; ALLOGENEIC MARROW TRANSPLANTATION; STEM-CELL TRANSPLANTATION; PHASE-I-II; MONOCLONAL-ANTIBODIES; I-131-ANTI-CD45 ANTIBODY; MYELODYSPLASTIC SYNDROME; IBRITUMOMAB TIUXETAN AB Purpose: Radioimmunotherapy may improve the outcome of hematopoietic cell transplantation for hematologic malignancies by delivering targeted radiation to hematopoietic organs while relatively sparing nontarget organs. We evaluated the organ localization of yttrium-90-labeled anti-CD45 (Y-90-anti-CD45) antibody in macaques, a model that had previously predicted iodine-131-labeled anti-CD45 (I-131-anti-CD45) antibody biodistribution in humans. Experimental Design: Twelve Macaca nemestrina primates received anti-CD45 antibody labeled with 1 to 2 mCi of Y-90 followed by serial blood sampling and marrow and lymph node biopsies, and necropsy. The content of Y-90 per gram of tissue was determined by liquid scintillation spectrometry. Time-activity curves were constructed using average isotope concentrations in each tissue at measured time points to yield the fractional residence time and estimate radiation absorbed doses for each organ per unit of administered activity. The biodistribution of Y-90-anti-CD45 antibody was then compared with that previously obtained with I-131-anti-CD45 antibody in macaques. Results: The spleen received 2,120, marrow 1,060, and lymph nodes 315 cGy/mCi of Y-90 injected. The liver and lungs were the nontarget organs receiving the highest radiation absorbed doses (440 and 285 cGy/mCi, respectively). Ytrrium-90-labeled anti-CD45 antibody delivered 2.5- and 3.7-fold more radiation to marrow than to liver and lungs, respectively. The ratios previously observed with I-131-antiCD45 antibody were 2.5- and 2.2-fold more radiation to marrow than to liver and lungs, respectively. Conclusions: This study shows that Y-90-anti-CD45 antibody can deliver relatively selective radiation to hematopoietic tissues, with similar ratios of radiation delivered to target versus nontarget organs, as compared with the I-131 immunoconjugate in the same animal model. C1 Fred Hutchinson Canc Res Ctr, Div Clin Res, Seattle, WA 98109 USA. Univ Washington, Dept Pediat, Seattle, WA 98195 USA. Univ Washington, Dept Med, Seattle, WA 98195 USA. Univ Washington, Dept Radiol, Seattle, WA 98195 USA. Univ Washington, Dept Radiat Oncol, Seattle, WA 98195 USA. Pacific NW Natl Lab, Richland, WA USA. RP Nemecek, ER (reprint author), Fred Hutchinson Canc Res Ctr, Div Clin Res, 1100 Fairview Ave N,POB 19024,MS D5-280, Seattle, WA 98109 USA. EM enemecek@fhcrc.org FU NCI NIH HHS [CA 71077, CA 100394, P01 CA042045, CA 44991] NR 49 TC 10 Z9 11 U1 0 U2 1 PU AMER ASSOC CANCER RESEARCH PI PHILADELPHIA PA 615 CHESTNUT ST, 17TH FLOOR, PHILADELPHIA, PA 19106-4404 USA SN 1078-0432 J9 CLIN CANCER RES JI Clin. Cancer Res. PD JAN 15 PY 2005 VL 11 IS 2 BP 787 EP 794 PG 8 WC Oncology SC Oncology GA 889IZ UT WOS:000226438000048 PM 15701869 ER PT J AU Sun, XG Hou, J Kerr, JB AF Sun, XG Hou, J Kerr, JB TI Comb-shaped single ion conductors based on polyacrylate ethers and lithium alkyl sulfonate SO ELECTROCHIMICA ACTA LA English DT Article DE single ion conductor; ionic conductivity; polyacrylate ethers; plasticizer ID POLY(ETHYLENE OXIDE); POLYMER ELECTROLYTES; TRANSPORT-PROPERTIES; GEL ELECTROLYTE; CONDUCTIVITY; PERFORMANCE; POLYELECTROLYTES; SIMULATIONS; COMPLEXES; SALTS AB Comb-shaped single ion conductors have been synthesized by (1) sulfonation of small molecule chloroethyleneglycols, which, after ion exchange to the Li+ salt were then converted to the acrylate by reaction with acryloyl chloride and copolymerized with polyethylene glycol monomethyl ether acrylate (Mn = 454, n = 8) (PAE(8)-co-E3SO3Li); (2) sulfonation of chloride end groups grafted on to prepolymers of polyacrylate ethers (PAE(8)-g-EnSO3Li, n = 2, 3). The highest conductivity at 25 degreesC of 2.0 x 10(-7) S cm(-1) was obtained for the PAE(8)-co-E3SO3Li with a salt concentration of EO/Li = 40. The conductivity of PAE(8)-g-E3SO3Li is lower than that of PAE(8)-co-E3SO3Li at similar salt concentrations, which is related to the incomplete sulfonation of the grafted polymer that leads to a lower concentration of Li+. The addition of 50 wt.% of plasticizer, PC/EMC (1/1, v/v), to PAE(8)-g-E2SO3Li increases the ambient conductivity by three orders of magnitude, which is due to the increased ion mobility in a micro-liquid environment and an increase concentration of free ions as a result of the higher dielectric constant of the solvent. A symmetrical Li/Li cell with an electrolyte membrane consisting of 75 wt.% PC/EMC (1/1, v/v) was cycled at a current density of 100 muA cm(-2) at 85 degreesC. The cycling profile showed no concentration polarization after a break-in period during the first few cycles, which was apparently due to reaction of the solvent at the lithium metal surface that reacted with lithium metal to form a stable SEI layer. (C) 2004 Elsevier Ltd. All rights reserved. C1 EETD, Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. RP Kerr, JB (reprint author), EETD, Lawrence Berkeley Natl Lab, MS 62-203,1 Cyclotron Rd, Berkeley, CA 94720 USA. EM xsun@lbl.gov; jbkerr@lbl.gov NR 33 TC 21 Z9 21 U1 5 U2 24 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0013-4686 J9 ELECTROCHIM ACTA JI Electrochim. Acta PD JAN 15 PY 2005 VL 50 IS 5 BP 1139 EP 1147 DI 10.1016/j.electacta.2004.08.011 PG 9 WC Electrochemistry SC Electrochemistry GA 889DX UT WOS:000226424800007 ER PT J AU Limoges, BR Stanis, RJ Turner, JA Herring, AM AF Limoges, BR Stanis, RJ Turner, JA Herring, AM TI Electrocatalyst materials for fuel cells based on the polyoxometalates [PMo(12-n)VnO40]((3+n)-) (n=0-3) SO ELECTROCHIMICA ACTA LA English DT Article DE heteropoly acid; vanadium; PEM fuel cell; hydrogen oxidation; oxygen reduction ID MOLYBDOVANADOPHOSPHORIC ACIDS; ELECTROCHEMICAL PROPERTIES; OXYGEN REDUCTION; HETEROPOLY ACIDS; OXIDATION; COMPLEXES; VANADIUM; ADSORPTION; CATALYSTS; METHANOL AB We report on the use of the polyoxometalate acids of the series [PMo(12-n)VnO40]((3+n)-) (n = 0-3) as electrocatalysts in both the anode and the cathode of polymer-electrolyte membrane (PEM) fuel cells. The heteropolyacids were incorporated as catalysts in a commercial gas diffusion electrode based on Vulcan XC-72 carbon which strongly adsorbed a low loading of the catalyst, ca. 0.1 mg/cm(2). The moderate activity observed was independent of the number of vanadium atoms in the polyoxometalate. In the anode the electrochemistry is dominated by the V3+/(4+) couple. With a platinum reference wire in contact with the anode, polarization curves are obtained with V-OC of 650 mV and current densities of 10 mA cm(-2) at 100 mV at 80degreesC. These catalysts showed an order of magnitude more activity on the cathode after moderate heat treatment than on the anode, V-OC = 750 mV, current densities of 140 mA cm(-2) at 100 mV. The temperature dependence of the catalysts was also investigated and showed increasing current densities could be achieved on the anode up to 139degreesC and the cathode to 100degreesC showing the potential for these materials to work at elevated temperatures. (C) 2004 Elsevier Ltd. All rights reserved. C1 Colorado Sch Mines, Dept Chem Engn, Golden, CO 80401 USA. Hydrogen & Elect Syst & Infrastruct Grp, Natl Renewable Energy Lab, Golden, CO 80401 USA. RP Colorado Sch Mines, Dept Chem Engn, Golden, CO 80401 USA. EM aherring@mines.edu RI Herring, Andy/E-7088-2010; OI Herring, Andrew/0000-0001-7318-5999 NR 36 TC 50 Z9 53 U1 5 U2 37 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0013-4686 EI 1873-3859 J9 ELECTROCHIM ACTA JI Electrochim. Acta PD JAN 15 PY 2005 VL 50 IS 5 BP 1169 EP 1179 DI 10.1016/j.electacta.2004.08.014 PG 11 WC Electrochemistry SC Electrochemistry GA 889DX UT WOS:000226424800010 ER PT J AU McKone, TE Deshpande, AW AF McKone, TE Deshpande, AW TI Can fuzzy logic bring complex environmental problems into fucus? SO ENVIRONMENTAL SCIENCE & TECHNOLOGY LA English DT Article ID HEALTH AB On modeling complex environmental problems, researchers often fail to make precise statements about inputs and outcome, but fuzzy logic could help. C1 Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. RP McKone, TE (reprint author), Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. EM temckone@lbl.gov NR 11 TC 21 Z9 22 U1 2 U2 7 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 JAN 15 PY 2005 VL 39 IS 2 BP 42A EP 47A DI 10.1021/es0531632 PG 6 WC Engineering, Environmental; Environmental Sciences SC Engineering; Environmental Sciences & Ecology GA 889KG UT WOS:000226441300009 PM 15707036 ER PT J AU Villalobos, M Bargar, J Sposito, G AF Villalobos, M Bargar, J Sposito, G TI Mechanisms of Pb(II) sorption on a biogenic manganese oxide SO ENVIRONMENTAL SCIENCE & TECHNOLOGY LA English DT Article ID BOND-VALENCE DETERMINATION; SURFACE FUNCTIONAL-GROUPS; CONTAMINATED SOILS; WATER INTERFACES; LEAD; PB; PRODUCTS; BIOFILMS; XAFS; COMPLEXATION AB Macroscopic Pb(II) uptake experiments and Pb L-3-edge extended X-ray absorption fine structure (EXAFS) spectroscopy were combined to examine the mechanisms of Pb(II) sequestration by a biogenic manganese oxide and its synthetic analogues, all of which are layer-type manganese oxides (phyllomanganates). Relatively fast Pb(II) sorption was observed, as well as extremely high sorption capacities, suggesting Pb incorporation into the structure of the oxides. EXAFS analysis revealed similar uptake mechanisms regardless of the specific nature of the phyllomanganate, electrolyte background, total Pb(II) loading, or equilibration time. One Pb-O and two Pb-Mn shells at distances of 2.30, 3.53, and 3.74 Angstrom, respectively, were found, as well as a linear relationship between Brunauer-Emmett-Teller (BET; i.e., external) specific surface area and maximum Pb(II) sorption that also encompassed data from previous work. Both observations support the existence of two bonding mechanisms in Pb(II) sorption: a triple-corner-sharing complex in the interlayers above/ below cationic sheet vacancies (N theoretical = 6), and a double-corner-sharing complex on particle edges at exposed singly coordinated -O(H) bonds (N theoretical = 2). General prevalence of external over internal sorption is predicted, but the two simultaneous sorption mechanisms can account for the widely noted high affinity of manganese oxides for Pb(II) in natural environments. C1 Univ Nacl Autonoma Mexico, Inst Geog, LAFQA, Environm Biogeochem Grp, Mexico City 04510, DF, Mexico. Stanford Synchrotron Radiat Lab, SLAC, Stanford, CA 94309 USA. Univ Calif Berkeley, Div Ecosyst Sci, Berkeley, CA 94720 USA. RP Univ Nacl Autonoma Mexico, Inst Geog, LAFQA, Environm Biogeochem Grp, Circuito Exterior,Ciudad Univ, Mexico City 04510, DF, Mexico. EM marvilla@igiris.igeograf.unam.mx RI Villalobos, Mario/A-1203-2007; Grandjean, Agnes/H-3115-2011 NR 34 TC 114 Z9 133 U1 10 U2 69 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0013-936X EI 1520-5851 J9 ENVIRON SCI TECHNOL JI Environ. Sci. Technol. PD JAN 15 PY 2005 VL 39 IS 2 BP 569 EP 576 DI 10.1021/es049434a PG 8 WC Engineering, Environmental; Environmental Sciences SC Engineering; Environmental Sciences & Ecology GA 889KG UT WOS:000226441300030 PM 15707057 ER PT J AU Icopini, GA Brantley, SL Heaney, PJ AF Icopini, GA Brantley, SL Heaney, PJ TI Kinetics of silica oligomerization and nanocolloid formation as a function of pH and ionic strength at 25 degrees C SO GEOCHIMICA ET COSMOCHIMICA ACTA LA English DT Article ID DILUTE AQUEOUS-SOLUTION; COLLOIDAL SILICA; POLYMERIZATION; TEMPERATURES; PRESSURES; STABILITY; GROWTH; ACID AB Rate laws reported for the oligomerization of silica in natural environments are often contradictory, and the kinetics of monosilicic acid condensation are poorly understood. Here we present rate expressions that systematically describe the initial oligomerization of silica in terms of concentration of initial silica, ionic strength, and pH for a natural brine solution. The oligomerization of silica in dilute aqueous solutions was examined in solutions with ionic strengths of 0.01 and 0.24 molal, from pH 3 to 11, and with initial silica concentrations of 4.2, 12.5, and 20.8 millimolal (250, 750, and 1250 ppm SiO2 respectively). The decrease in concentration of molybdate-reactive silica was monitored over time to determine the extent of oligomerization. This decrease in concentration of molybdate-reactive silica is accompanied by the appearance of a transient population of nanocolloidal particles with diameter similar to3 nm, as determined by atomic force microscopy (AFM). The oligomerization rate increases as pH approaches near neutral and as ionic strength increases. Early in the reaction where the concentration of molybdate-reactive silica, [SiO2](nless than or equal to3), is assumed to equal the concentration of monosilicic acid, [H4SiO4], the rate of change of monosilicic acid as a function of time, R, shows a fourth-order dependence: R = k(4)[H4SiO4](4) Furthermore, the log of the rate constant (k(4), millimolal(-3) s(-1)) varies linearly with pH according to log k(4) = m pH + log k(o), where k(o) is the rate constant at pH 0 and m is an empiric constant. The value of m is positive below pH 7 and negative above pH 7. The observed fourth-order rate dependence with respect to [H4SiO4] is consistent with formation of a critical nucleus with four silica groups during the oligomerization of silica into metastable nanocolloidal silica. The sensitivity of the reaction rate constant, k(4), to ionic strength and to silica concentration as a function of pH suggests that the critical species (in our model, a cyclic tetramer) chemically behaves as a bulk surface. In the brine solution employed in this study at 25degreesC, nanocolloids are relatively stable at low pH and at low ionic strength, and thus such colloids would be expected to occur in natural solutions even as they approach steady-state equilibrium with amorphous silica. The form of the log rate (oligomerization) vs. pH curve is roughly the inverse of the form of the log rate (dissolution)-pH curve for feldspar dissolution, and therefore may also be indicative of the importance of silica condensation reactions during feldspar dissolution. Copyright (C) 2005 Elsevier Ltd. C1 Los Alamos Natl Lab, Div Chem, Los Alamos, NM 87545 USA. Penn State Univ, Dept Geosci, University Pk, PA 16802 USA. RP Icopini, GA (reprint author), Los Alamos Natl Lab, Div Chem, MS J-514, Los Alamos, NM 87545 USA. EM gicopini@lanl.gov NR 36 TC 87 Z9 90 U1 3 U2 42 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0016-7037 J9 GEOCHIM COSMOCHIM AC JI Geochim. Cosmochim. Acta PD JAN 15 PY 2005 VL 69 IS 2 BP 293 EP 303 DI 10.1016/j.gca.2004.06.038 PG 11 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 891GH UT WOS:000226568800005 ER PT J AU Apra, E Carter, EA Fortunelli, A AF Apra, E Carter, EA Fortunelli, A TI Separability between valence and conduction bands in transition metal clusters (vol 100, pg 277, 2004) SO INTERNATIONAL JOURNAL OF QUANTUM CHEMISTRY LA English DT Correction C1 Pacific NW Natl Lab, Environm Mol Sci Lab, Richland, WA 99352 USA. Univ Calif Los Angeles, Dept Chem & Biochem, Los Angeles, CA 90095 USA. CNR, Mol Modeling Lab, IPCF, I-56010 Ghezzano, PI, Italy. RP Apra, E (reprint author), Pacific NW Natl Lab, Environm Mol Sci Lab, POB 999, Richland, WA 99352 USA. RI Apra, Edoardo/F-2135-2010 OI Apra, Edoardo/0000-0001-5955-0734 NR 1 TC 0 Z9 0 U1 0 U2 0 PU JOHN WILEY & SONS INC PI HOBOKEN PA 111 RIVER ST, HOBOKEN, NJ 07030 USA SN 0020-7608 J9 INT J QUANTUM CHEM JI Int. J. Quantum Chem. PD JAN 15 PY 2005 VL 101 IS 2 BP 230 EP 230 DI 10.1002/qua.20355 PG 1 WC Chemistry, Physical; Mathematics, Interdisciplinary Applications; Physics, Atomic, Molecular & Chemical SC Chemistry; Mathematics; Physics GA 880TJ UT WOS:000225811900012 ER PT J AU Biener, J Hodge, AM Hamza, AV Hsiung, LM Satcher, JH AF Biener, J Hodge, AM Hamza, AV Hsiung, LM Satcher, JH TI Nanoporous Au: A high yield strength material SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID PLASTIC-DEFORMATION; CORROSION; SURFACES; BEHAVIOR; CONTACTS; CRACKING; ALLOYS; METALS; SIZE; FOAM AB The plastic deformation of nanoporous Au under compressive stress was studied by depth-sensing nanoindentation combined with scanning electron microscope characterization. The nanoporous Au investigated in the current study exhibits a relative density of 42%, and a spongelike morphology of interconnecting ligaments on a length scale of similar to100 nm. The material is polycrystalline with a grain size on the order of 10-60 nm. Microstructural characterization of residual indentation impressions reveals a localized densification via ductile (plastic) deformation under compressive stress and demonstrates the ductile behavior of Au ligaments. A mean hardness of 145(+/-11) MPa and a Young's modulus of 11.1(+/-0.9) GPa was obtained from the analysis of the load-displacement curves. The hardness of investigated np-Au is similar to10 times higher than the hardness predicted by scaling laws of open-cell foams thus potentially opening a door to a class of high yield strength-low-density materials. (C) 2005 American Institute of Physics. C1 Lawrence Livermore Natl Lab, Nanoscale Synth & Characterizat Lab, Livermore, CA 94550 USA. RP Biener, J (reprint author), Lawrence Livermore Natl Lab, Nanoscale Synth & Characterizat Lab, POB 808,L-370, Livermore, CA 94550 USA. EM biener2@llnl.gov NR 24 TC 137 Z9 140 U1 4 U2 55 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD JAN 15 PY 2005 VL 97 IS 2 AR 024301 DI 10.1063/1.1832742 PG 4 WC Physics, Applied SC Physics GA 893DW UT WOS:000226700500073 ER PT J AU Czaplewski, DA Sullivan, JP Friedmann, TA Carr, DW Keeler, BEN Wendt, JR AF Czaplewski, DA Sullivan, JP Friedmann, TA Carr, DW Keeler, BEN Wendt, JR TI Mechanical dissipation in tetrahedral amorphous carbon SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID ENERGY-DISSIPATION; LOW-TEMPERATURES; SILICON; DIAMOND; OSCILLATORS; CANTILEVERS; RESONATORS; GLASSES; SYSTEMS; MEMS AB We have fabricated micromechanical oscillators from tetrahedrally coordinated amorphous carbon (ta-C) in order to study mechanical dissipation mechanisms in this material. Cantilever oscillators with either in-plane or out-of-plane dominant transverse vibrational modes and free-free beam oscillators with in-plane modes were fabricated with critical dimensions ranging from 75 nm to over 1 mm. The resonant frequency and quality factor were measured for all oscillators. The resonant frequencies ranged from a few kilohertz to several megahertz, while the quality factor remained nearly constant at approximately 2-4x10(3). Possible dissipation mechanisms were evaluated for these oscillators, and it was found that the observed dissipation was not limited by mechanical clamping losses, air damping, thermoelastic dissipation, or dissipation due to phonon-mechanical vibration interactions. However, an extrinsic dissipation mechanism in which dissipation is limited by a spectrum of defects in ta-C was found to be consistent with the observed behavior. Assuming that the mechanical relaxation associated with the dissipative defects is thermally activated, we derive a defect distribution that is relatively flat with activation energies ranging from about 0.35 to over 0.55 eV. (C) 2005 American Institute of Physics. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Czaplewski, DA (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. NR 36 TC 22 Z9 22 U1 0 U2 3 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD JAN 15 PY 2005 VL 97 IS 2 AR 023517 DI 10.1063/1.1821638 PG 10 WC Physics, Applied SC Physics GA 893DW UT WOS:000226700500031 ER PT J AU Istratov, AA Zhang, P McDonald, RJ Smith, AR Seacrist, M Moreland, J Shen, J Wahlich, R Weber, ER AF Istratov, AA Zhang, P McDonald, RJ Smith, AR Seacrist, M Moreland, J Shen, J Wahlich, R Weber, ER TI Nickel solubility in intrinsic and doped silicon SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID ELECTRON-PARAMAGNETIC-RESONANCE; NEUTRON-ACTIVATION ANALYSIS; TRANSITION-METALS; SOLID SOLUBILITY; COPPER; DIFFUSION; DEFECTS; SEMICONDUCTORS; GERMANIUM; WAFERS AB Solubility of nickel in intrinsic, moderately, and heavily doped n-type and p-type silicon was determined using instrumental neutron activation analysis. The solubility data for intrinsic silicon were found to be in good agreement with the literature data. In heavily doped p-type silicon the enhancement of nickel solubility, if present, was close to the error margins of the experiment, indicating that interstitial nickel is predominantly neutral in silicon and suggesting that its donor level lies close to the valence band edge, if not within the valence band itself. No dependence of nickel solubility on doping level of the samples was observed in n-type silicon. This is consistent with the model reported in the literature of two acceptor levels of substitutional nickel located in the upper half of the band gap, one of the levels close to the conduction band edge. Consequently, unlike copper or iron, nickel does not segregate in heavily p-type or n-type doped areas of silicon wafers. (C) 2005 The American Institute of Physics. C1 Univ Calif Berkeley, Dept Mat Sci & Engn, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Nucl Phys, Berkeley, CA 94720 USA. MEMC Elect Mat, St Peters, MO 63376 USA. Siltron Corp, Portland, OR 97210 USA. Siltron AG, Burghausen, Germany. RP Istratov, AA (reprint author), Univ Calif Berkeley, Dept Mat Sci & Engn, Berkeley, CA 94720 USA. EM istratov@socrates.berkeley.edu NR 39 TC 31 Z9 31 U1 0 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 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD JAN 15 PY 2005 VL 97 IS 2 AR 023505 DI 10.1063/1.1836852 PG 6 WC Physics, Applied SC Physics GA 893DW UT WOS:000226700500019 ER PT J AU Liu, B Leone, SR Kitajima, T Zhang, TH Borca, C AF Liu, B Leone, SR Kitajima, T Zhang, TH Borca, C TI Imaging of defect-mediated surface morphology of GaN(000(1)over-bar) grown on sapphire by molecular beam epitaxy SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID QUANTUM DOTS; GAN; WURTZITE; KINETICS; DISLOCATIONS; MICROSCOPY; GAN(0001); POLARITY AB In situ scanning tunneling microscopy and ex situ atomic force microscopy are used to study the surface morphology of GaN(000 (1) over bar ) grown on sapphire substrates by plasma-assisted molecular beam epitaxy. Several types of defect-mediated surface morphologies are characterized, including surface terminations of screw and mixed dislocations, defect-induced grooves, and impurity-induced step bunching. In addition to the early theory of dislocation-enhanced crystal growth developed by Frank [F. C. Frank, Acta Crystallogr 4, 497 (1951)] step structures are also found to be critical to understand the formation of spiral growth hillocks around surface terminations of different types of threading dislocations. Growth experiments are also performed under different conditions, e.g., by varying III/V flux ratio and growth temperature to further investigate the relationship between the final surface morphology and the early stages of growth, such as sapphire nitridation and the transition stage from the three-dimensional buffer layer growth under nitrogen-rich conditions to the two-dimensional active layer growth under slightly Ga-rich conditions. (C) 2005 American Institute of Physics. C1 Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. Natl Def Acad Japan, Yokosuka, Kanagawa 2398686, Japan. Natl Inst Stand & Technol, Joint Inst Lab Astrophys, Boulder, CO 80309 USA. Univ Colorado, Dept Phys, Boulder, CO 80309 USA. RP Liu, B (reprint author), Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. EM srl@cchem.berkeley.edu NR 25 TC 6 Z9 6 U1 1 U2 7 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD JAN 15 PY 2005 VL 97 IS 2 AR 023509 DI 10.1063/1.1839636 PG 8 WC Physics, Applied SC Physics GA 893DW UT WOS:000226700500023 ER PT J AU Menikoff, R Dick, JJ Hooks, DE AF Menikoff, R Dick, JJ Hooks, DE TI Analysis of wave profiles for single-crystal cyclotetramethylene tetranitramine SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID PRECURSOR DECAY AB Wave profiles measured in the beta-polymorph of single-crystal cyclotetramethylene tetranitramine display the characteristic response of an elastic-plastic material, an elastic precursor followed by a plastic wave. Moreover, the elastic precursor decays with the length of run. Numerical simulations with a rate-dependent elastic-plastic model are used to account for nonlinear and transient wave behavior. In addition, to account for the measured anisotropy in propagation, parameters of an isotropic model are fit for two propagation directions, normal to the (011) and (010) planes of the P2(1)/n space group. Equation of state parameters are constrained by data for the longitudinal sound speed and hydrostatic compression. The fits show that the effective yield strength varies with direction from 0.18 GPa for the (011) orientation to 0.31 GPa in the (010) orientation. (C) 2005 American Institute of Physics. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Menikoff, R (reprint author), Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. EM rtm@lanl.gov NR 23 TC 25 Z9 26 U1 1 U2 2 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD JAN 15 PY 2005 VL 97 IS 2 AR 023529 DI 10.1063/1.1828602 PG 6 WC Physics, Applied SC Physics GA 893DW UT WOS:000226700500043 ER PT J AU Perry, WL Dickson, PM Parker, GR Asay, BW AF Perry, WL Dickson, PM Parker, GR Asay, BW TI Quantification of reaction violence and combustion enthalpy of plastic bonded explosive 9501 under strong confinement SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID PBX-9501 AB The confinement experienced by an explosive during thermal self-initiation can substantially affect performance in terms of deflagration-to-detonation characteristics and explosion/detonation violence. To this end, we have developed an experiment to quantitatively observe enthalpy change and reaction violence in thermally initiated plastic bonded explosive (PBX) 9501. Traditionally, researchers attempt to quantify violence using terminal observations of fragment size, fragment velocity, and through subjective observations. In the work presented here, the explosive was loaded into a heated gun assembly where we subjected a 300 mg charge to a cook-off schedule and a range of static and inertial confinements. Static confinement was controlled using rupture disks calibrated at 34.5 and 138 MPa. The use of 3.15 and 6.3 g projectile masses provided a variation in inertial confinement. This was a regime of strong confinement; a significant fraction of the explosive energy was required to rupture the disk, and the projectile mass was large compared to the charge mass. The state variables pressure and volume were measured in the breech. From these data, we quantified both the reaction enthalpy change and energy release rate of the explosive on a microsecond time scale using a thermodynamic analyisis. We used these values to unambiguously quantify explosion violence as a function of confinement at a fixed cook-off schedule of 190 C for 1 h. P(2)tau, a measure of critical shock energy required for shock ignition of an adjacent explosive was also computed. We found variations in this confinement regime to have a weak effect on enthalpy change, power, violence and shock energy. Violence was approximately 100 times lower than detonating trinitrotoluene, but the measured shock energy approached the critical shock energy for initiating secondary high explosives. (C) 2005 American Institute of Physics. C1 Los Alamos Natl Lab, High Explos Phys Team, Dynam Experimentat Div, Los Alamos, NM 87545 USA. RP Perry, WL (reprint author), Los Alamos Natl Lab, High Explos Phys Team, Dynam Experimentat Div, POB 1663,Mail Stop C920, Los Alamos, NM 87545 USA. EM wperry@lanl.gov NR 14 TC 3 Z9 3 U1 0 U2 5 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD JAN 15 PY 2005 VL 97 IS 2 AR 023528 DI 10.1063/1.1828220 PG 8 WC Physics, Applied SC Physics GA 893DW UT WOS:000226700500042 ER PT J AU Puthenkovilakam, R Lin, YS Choi, J Lu, J Blom, HO Pianetta, P Devine, D Sendler, M Chang, JP AF Puthenkovilakam, R Lin, YS Choi, J Lu, J Blom, HO Pianetta, P Devine, D Sendler, M Chang, JP TI Effects of post-deposition annealing on the material characteristics of ultrathin HfO2 films on silicon SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID ATOMIC LAYER DEPOSITION; HAFNIUM OXIDE; THERMAL-DECOMPOSITION; GATE DIELECTRICS; SI; STABILITY; STACKS; ZRO2 AB High quality HfO2 films were deposited on p-type Si(100) wafers by an atomic layer deposition scheme. The deposited films were smooth, amorphous, and stoichiometric, as determined by atomic force microscopy, x-ray diffraction, and x-ray photoelectron spectroscopy, respectively. The as-deposited films showed a very small interfacial layer between the HfO2 and silicon. The index of refraction of the film was determined to be slightly smaller than that of bulk HfO2 by spectroscopic ellipsometry. The films annealed in O-2 and NH3 at 800 degreesC showed a growth of the interfacial layer, which resembles a SiO2-rich dielectric layer. Short-range order in the as-deposited films was determined to be monoclinic by the extended x-ray absorption fine structure measurements, and signs of crystallization were observed in the O-2 annealed sample. The films appeared to be polycrystalline upon high temperature (800 degreesC) annealing as confirmed by high-resolution transmission electron microscopy. Annealing in the forming gas (450 degreesC) resulted in a more substantial growth of the interfacial layer, though the film remained amorphous. (C) 2005 American Institute of Physics. C1 Univ Calif Los Angeles, Dept Chem Engn, Los Angeles, CA 90095 USA. Nova Measuring Instruments, Phoenix, AZ 85040 USA. Mattson Technol Inc, Fremont, CA 94538 USA. Stanford Synchrotron Radiat Lab, Menlo Pk, CA 94025 USA. Univ Uppsala, Angstrom Lab, SE-75121 Uppsala, Sweden. RP Chang, JP (reprint author), Univ Calif Los Angeles, Dept Chem Engn, Los Angeles, CA 90095 USA. EM jpchang@ucla.edu RI Lu, Jun/K-3321-2015 OI Lu, Jun/0000-0003-2754-6962 NR 24 TC 35 Z9 38 U1 1 U2 11 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD JAN 15 PY 2005 VL 97 IS 2 AR 023704 DI 10.1063/1.1831543 PG 7 WC Physics, Applied SC Physics GA 893DW UT WOS:000226700500051 ER PT J AU Sinha, S Schelling, PK Phillpot, SR Goodson, KE AF Sinha, S Schelling, PK Phillpot, SR Goodson, KE TI Scattering of g-process longitudinal optical phonons at hotspots in silicon SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID LATTICE THERMAL-CONDUCTIVITY; MOLECULAR-DYNAMICS; HEAT-CONDUCTION; AMORPHOUS-SILICON; SIMULATION; TRANSPORT; SEMICONDUCTORS; LIFETIMES AB Transistors with gate lengths below 100 nm generate phonon hotspots with dimensions on the order of 10 nm and peak power densities of about 50 W/mum(3). This work employs molecular dynamics to investigate the impact of lattice energy density on phonon scattering at the hotspot. The hotspot studied in this work consists of longitudinal optical phonons involved in the g-type intervalley scattering of conduction electrons in silicon. A comparison of the decay modes in hotspots with high and moderate energy densities reveals that the decay mechanisms are the same but the relaxation rates differ. Scattering occurs through a three phonon process of the form LO-->LA+TA, involving the zone-edge transverse acoustic modes. An increase in the energy density from a moderate value of 5 to 125 W/mum(3) changes the relaxation time from 79 to 16 ps, approximately proportional to the the maximum initial amplitude of the phonons. This work improves the accuracy of the scattering rates of optical phonons and helps in advancing the electro-thermal modeling of nanotransistors. (C) 2005 American Institute of Physics. C1 Stanford Univ, Dept Mech Engn, Thermosci Div, Stanford, CA 94305 USA. Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. Univ Cent Florida, Adv Mat Proc & Anal Ctr, Orlando, FL 32816 USA. Univ Cent Florida, Dept Phys, Orlando, FL 32816 USA. Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. Univ Florida, Dept Mat Sci & Engn, Gainesville, FL 32611 USA. Stanford Univ, Dept Mech Engn, Thermosci Div, Stanford, CA 94305 USA. RP Sinha, S (reprint author), Stanford Univ, Dept Mech Engn, Thermosci Div, Stanford, CA 94305 USA. EM sanjiv@stanford.edu RI Goodson, Kenneth/C-3545-2011; Sinha, Sanjiv/A-7661-2012; Phillpot, Simon/J-9117-2012 NR 28 TC 42 Z9 42 U1 0 U2 7 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD JAN 15 PY 2005 VL 97 IS 2 AR 023702 DI 10.1063/1.1831549 PG 9 WC Physics, Applied SC Physics GA 893DW UT WOS:000226700500049 ER PT J AU Zhao, ZB Rek, ZU Yalisove, SM Bilello, JC AF Zhao, ZB Rek, ZU Yalisove, SM Bilello, JC TI Evolution of in-plane texture in reactively sputtered CrN films SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID CHROMIUM NITRIDE FILMS; THIN-FILMS; MAGNETIC-ANISOTROPY; RESIDUAL-STRESS; GROWTH; MICROSTRUCTURE; MODEL AB The microstructure and texture of chromium nitride films reactively sputtered on silicon substrates were investigated using x-ray scattering, pole figures, transmission electron microscopy, and atomic force microscopy. Under the given deposition geometry, the CrN films were shown to develop a in-plane texture. The three preferred crystallographic orientations of the CrN films approximately coincided with the characteristic directions associated with the deposition geometry. There appear to be two regimes that govern the microstructural evolution and texture development for reactively sputtered chromium films. The first one involves the deposition conditions that lead to the formation of a single, stable phase such as stoichiometric CrN (above certain level of nitrogen partial pressure). In this regime, the film growth appears to be controlled by local epitaxy in individual columns, competitive grain growth, and kinetic roughening. The film characteristics resulted from this regime include the development of the in-plane texture, well-organized microstructures with relatively coarse grains, increased surface roughness, and large tensile stress. The second regime involves the transitional region prior to formation of the stable phase CrN in which significant microstructural refinements take place. This transitional region is associated with the thermodynamically metastable phase CrNx or the presence of multiple phases. The continuous renucleations during film growth disrupt the local epitaxy and impede kinetic roughening. This leads to film characteristics manifested by weakened or no texture, ultrafine microstructure (e.g., nanocrystalline structures), reduced surface roughness, and a tendency for residual stress to transit from tensile to compressive. (C) 2004 American Institute of Physics. C1 Delphi Res Labs, Shelby Township, MI 48315 USA. Stanford Univ, Stanford Synchrotron Radiat Lab, Stanford, CA 94309 USA. Univ Michigan, Dept Mat Sci & Engn, Ann Arbor, MI 48109 USA. RP Zhao, ZB (reprint author), Delphi Res Labs, 51786 Shelby Pkwy, Shelby Township, MI 48315 USA. EM zhibo.zhao@delphi.com NR 21 TC 1 Z9 1 U1 1 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 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD JAN 15 PY 2005 VL 97 IS 2 AR 023525 DI 10.1063/1.1833022 PG 9 WC Physics, Applied SC Physics GA 893DW UT WOS:000226700500039 ER PT J AU Subotnik, JE Head-Gordon, M AF Subotnik, JE Head-Gordon, M TI A localized basis that allows fast and accurate second-order Moller-Plesset calculations SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID BODY PERTURBATION-THEORY; ELECTRON CORRELATION; REPRESENTATION; ENERGIES; ORBITALS; SYSTEMS; MP2 AB We present a method for computing a basis of localized orthonormal orbitals (both occupied and virtual), in whose representation the Fock matrix is extremely diagonal dominant. The existence of these orbitals is shown empirically to be sufficient for achieving highly accurate second-order Moller-Plesset (MP2) energies, calculated according to Kapuy's method. This method (which we abbreviate KMP2) involves a different partitioning of the n-electron Hamiltonian and scales at most quadratically, with potential for linearity, in the number of electrons. As such, we believe the KMP2 algorithm presented here could be the basis of a viable approach to local -correlation calculations. (C) 2005 American Institute of Physics. C1 Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Chem Sci, Berkeley, CA 94720 USA. RP Head-Gordon, M (reprint author), Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. EM mhg@cchem.berkley.edu NR 23 TC 32 Z9 32 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 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD JAN 15 PY 2005 VL 122 IS 3 AR 034109 DI 10.1063/1.1834911 PG 9 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 893VP UT WOS:000226748800012 PM 15740194 ER PT J AU Wang, SY Wang, CZ Chuang, FC Morris, JR Ho, KM AF Wang, SY Wang, CZ Chuang, FC Morris, JR Ho, KM TI Ab initio molecular dynamics simulation of liquid Al88Si12 alloys SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID TOTAL-ENERGY CALCULATIONS; WAVE BASIS-SET; GE ALLOYS; AL; MELT; METALS AB First-principles molecular dynamics simulations are carried out to study the structures, dynamics, and electronic properties of liquid Al88Si12 in the temperature ranging from 898 to 1298 K. The temperature dependence of static structure factors, pair correlation functions, and electronic density-of-states are investigated. The structural properties obtained from the simulations are in good agreement with the x-ray diffraction experimental results. (C) 2005 American Institute of Physics. C1 Fudan Univ, State Key Lab Adv Photon Mat & Devices, Dept Opt Sci & Engn, Shanghai 200433, Peoples R China. 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. Iowa State Univ, Ames Lab, US Dept Energy, Ames, IA 50011 USA. Iowa State Univ, Ames Lab, Dept Phys & Astron, Ames, IA 50011 USA. Oak Ridge Natl Lab, Met & Ceram Div, Oak Ridge, TN 37831 USA. RP Wang, SY (reprint author), Fudan Univ, State Key Lab Adv Photon Mat & Devices, Dept Opt Sci & Engn, Shanghai 200433, Peoples R China. RI Wang, Songyou/H-4529-2011; Chuang, FengChuan/H-7166-2013; Morris, J/I-4452-2012 OI Wang, Songyou/0000-0002-4249-3427; Chuang, FengChuan/0000-0003-0351-4253; Morris, J/0000-0002-8464-9047 NR 27 TC 16 Z9 16 U1 0 U2 5 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD JAN 15 PY 2005 VL 122 IS 3 AR 034508 DI 10.1063/1.1833355 PG 6 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 893VP UT WOS:000226748800027 PM 15740210 ER PT J AU Li, H Qian, MX Buck, E Strachan, DM AF Li, H Qian, MX Buck, E Strachan, DM TI Reply to "Comment on 'Extended electron energy loss fine structure simulation of the local boron environment in sodium aluminoboro silicate glasses containing gadolinium' by M. Qian, H. Li, L. Li and D.M. Strachan SO JOURNAL OF NON-CRYSTALLINE SOLIDS LA English DT Editorial Material ID EDGE STRUCTURE ELNES; BOROSILICATE GLASSES; LOSS SPECTROSCOPY; BETA-IRRADIATION; PHASE-SEPARATION; COORDINATION; MICROSCOPY; MINERALS; RAMAN C1 Pacific NW Natl Lab, Richland, WA 99352 USA. RP Li, H (reprint author), PPG Ind Inc, Glass Technol Ctr, Fundamental Sci, Fiber Glass Sci & Technol, Pittsburgh, PA USA. EM hli@ppg.com RI Buck, Edgar/D-4288-2009; Buck, Edgar/N-7820-2013 OI Buck, Edgar/0000-0001-5101-9084 NR 23 TC 0 Z9 0 U1 0 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3093 J9 J NON-CRYST SOLIDS JI J. Non-Cryst. Solids PD JAN 15 PY 2005 VL 351 IS 2 BP 186 EP 188 DI 10.1016/j.jnoncrysol.2004.07.090 PG 3 WC Materials Science, Ceramics; Materials Science, Multidisciplinary SC Materials Science GA 887IV UT WOS:000226300100013 ER PT J AU Rosu, L Cascaval, CN Ciobanu, C Rosu, D Ion, ED Morosanu, C Enachescu, M AF Rosu, L Cascaval, CN Ciobanu, C Rosu, D Ion, ED Morosanu, C Enachescu, M TI Effect of UV radiation on the semi-interpenetrating polymer networks based on polyurethane and epoxy maleate of bisphenol A SO JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY A-CHEMISTRY LA English DT Article DE UV radiation; polyurethane; epoxy maleate; networks; photooxidative degradation ID SEGMENTED POLYURETHANES; PHOTOCHEMICAL BEHAVIOR; INFRARED-ANALYSIS; MORPHOLOGY AB The behavior of two semi-interpenetrating polymer networks (S-IPNs) based on polyurethane (PU) and epoxy maleate of bisphenol A (EMBA) under exposure to UV radiation for long period of times (up to 200 h) was investigated. The networks obtained by the specific mixture under certain thermal treatment included in their structures crosslinked EMBA and linear PU. Advanced photooxidative degradation took place for long time of UV irradiation (over 160 h, especially), with almost a total destruction of the raw structures. The important modification of both the surface and of the morphology of the tested samples with the time of irradiation was also analyzed. Simultaneously, as compared to results obtained for short time of UV radiations (up to 10 h), where the mechanical properties of the tested samples improved, long time of UV radiations led to deterioration of many of the mechanical properties. (C) 2004 Elsevier B.V. All rights reserved. C1 Romanian Acad Alley Gr Ghica Voda, Dept Polymer Mat, Petru Poni Inst Macromol Chem, Iasi 700487, Romania. Natl Inst Mat Phys, Bucharest, Romania. Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. RP Cascaval, CN (reprint author), Romanian Acad Alley Gr Ghica Voda, Dept Polymer Mat, Petru Poni Inst Macromol Chem, 41A, Iasi 700487, Romania. EM cascaval@icmpp.tuiasi.ro RI Enachescu, Marius/C-4963-2011; Milliken, Elena/E-2159-2011 NR 16 TC 20 Z9 26 U1 1 U2 11 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 1010-6030 J9 J PHOTOCH PHOTOBIO A JI J. Photochem. Photobiol. A-Chem. PD JAN 15 PY 2005 VL 169 IS 2 BP 177 EP 185 DI 10.1016/j.jphotochem.2004.06.008 PG 9 WC Chemistry, Physical SC Chemistry GA 888NA UT WOS:000226380300009 ER PT J AU Prinja, AK Olson, GL AF Prinja, AK Olson, GL TI Grey radiative transfer in binary statistical media with material temperature coupling: asymptotic limits SO JOURNAL OF QUANTITATIVE SPECTROSCOPY & RADIATIVE TRANSFER LA English DT Article DE radiative transfer; participating random media; asymptotic limits ID TRANSPORT AB Simplified models for the unconditional ensemble-averaged radiation intensity and material energy are developed for radiative transfer in binary statistical media. Asymptotic analysis is used to construct an effective transport model with homogenized opacities in two limits. In the first, the material properties are assumed to have low contrast on average, and is shown to correctly reproduce the well-known atomic mix model in both time-dependent and equilibrium situations. Our analysis successfully resolves an inconsistency previously noted in the literature with the application of the standard definition of the atomic mix limit to radiative transfer in participating random media. In the second limit considered, the materials are assumed to have highly contrasting opacities, yielding a reduced transport model with effective scattering. The existence of these limits requires the mean chunk sizes to be independent of the photon direction and this creates an ambiguity in the interpretation of the models when the underlying stochastic geometry is comprised of alternating one-dimensional slabs. A consistent one-dimensional setting is defined and the asymptotic models are numerically validated over a broad range of physical parameter values. (C) 2004 Elsevier Ltd. All rights reserved. C1 Los Alamos Natl Lab, Transport Methods Grp CCS4, Los Alamos, NM 87545 USA. Univ New Mexico, Farris Engn Ctr 209, Dept Chem & Nucl Engn, Albuquerque, NM 87131 USA. RP Prinja, AK (reprint author), Los Alamos Natl Lab, Transport Methods Grp CCS4, Los Alamos, NM 87545 USA. EM prinja@unm.edu NR 14 TC 6 Z9 6 U1 0 U2 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0022-4073 J9 J QUANT SPECTROSC RA JI J. Quant. Spectrosc. Radiat. Transf. PD JAN 15 PY 2005 VL 90 IS 2 BP 131 EP 159 DI 10.1016/j.jqsrt.2004.03.010 PG 29 WC Optics; Spectroscopy SC Optics; Spectroscopy GA 857SU UT WOS:000224139400001 ER PT J AU Ramesh, A Melkote, SN Allard, LF Riester, L Watkins, TR AF Ramesh, A Melkote, SN Allard, LF Riester, L Watkins, TR TI Analysis of white layers formed in hard turning of AISI 52100 steel SO MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING LA English DT Article DE white layers; hard turning; plastic deformation; phase transformation ID ETCHING LAYERS; SURFACE; MECHANISM AB The formation mechanisms and properties of white layers produced in machining of hardened steels are not clearly understood to date. In particular, detailed analysis of their structure and mechanical properties is lacking. This paper investigates the differences in structure and properties of white layers formed during machining of hardened AISI 52100 steel (62 HRC) at different cutting speeds. A combination of experimental techniques including transmission electron microscopy (TEM), X-ray diffraction (XRD), and nano-indentation are used to analyze the white layers formed. TEM results suggest that white layers produced at low-to-moderate cutting speeds are in large part due to grain refinement induced by severe plastic deformation, whereas white layer formation at high cutting speeds is mainly due to thermally-driven phase transformation. The white layers at all speeds are found to be comprised of very fine (nano-scale) grains compared to the bulk material. XRD-based residual stress and retained austenite measurements, and hardness data support these findings. (C) 2004 Elsevier B.V. All rights reserved. C1 Georgia Inst Technol, George W Woodruff Sch Mech Engn, Atlanta, GA 30332 USA. Oak Ridge Natl Lab, High Temp Mat Lab, Oak Ridge, TN 37831 USA. RP Melkote, SN (reprint author), Georgia Inst Technol, George W Woodruff Sch Mech Engn, Atlanta, GA 30332 USA. EM shreyes.melkote@me.gatech.edu RI Watkins, Thomas/D-8750-2016 OI Watkins, Thomas/0000-0002-2646-1329 NR 31 TC 120 Z9 129 U1 0 U2 19 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0921-5093 J9 MAT SCI ENG A-STRUCT JI Mater. Sci. Eng. A-Struct. Mater. Prop. Microstruct. Process. PD JAN 15 PY 2005 VL 390 IS 1-2 BP 88 EP 97 DI 10.1016/j.msea.2004.08.052 PG 10 WC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Science & Technology - Other Topics; Materials Science; Metallurgy & Metallurgical Engineering GA 888KI UT WOS:000226372400011 ER PT J AU Nayak, S Wang, H Kenik, EA Anderson, IM Dahotre, NB AF Nayak, S Wang, H Kenik, EA Anderson, IM Dahotre, NB TI Observation of exothermic reaction during laser-assisted iron oxide coating on aluminum alloy SO MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING LA English DT Article DE infrared thermography; laser coating; A319; thermite reaction; iron oxides ID AL AB Aluminum and Fe3O4 reacts readily in what is known as thermite reaction to produce large amount of heat. Attempts were made to coat Feoxide on A319 cast aluminum alloy employing a high power laser to exploit this reaction. High-speed, high-resolution infrared thermography was employed to study the thermal conditions during the laser treatment. Parallel experiment using a less exothermic oxide (FeO) and the same substrate further emphasized development of higher temperature during highly exothermic reaction. The cooling rate calculated via both steady state and non-steady state relations were one order of magnitude different, which was supported by microstructural observations. Transmission electron microscopy revealed formation of aluminides as a result of reaction between iron oxide and aluminum alloys. (C) 2004 Elsevier B.V. All rights reserved. C1 Univ Tennessee, Dept Mat Sci & Engn, Knoxville, TN 37932 USA. Oak Ridge Natl Lab, High Temp Mat Lab, Oak Ridge, TN 37831 USA. Oak Ridge Natl Lab, Mat Proc Grp, Oak Ridge, TN USA. Oak Ridge Natl Lab, Div Met & Ceram, Oak Ridge, TN USA. RP Dahotre, NB (reprint author), Univ Tennessee, Dept Mat Sci & Engn, Knoxville, TN 37932 USA. EM ndahotre@utk.edu RI Wang, Hsin/A-1942-2013 OI Wang, Hsin/0000-0003-2426-9867 NR 21 TC 3 Z9 3 U1 0 U2 0 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0921-5093 J9 MAT SCI ENG A-STRUCT JI Mater. Sci. Eng. A-Struct. Mater. Prop. Microstruct. Process. PD JAN 15 PY 2005 VL 390 IS 1-2 BP 404 EP 413 DI 10.1016/j.msea.2004.08.008 PG 10 WC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Science & Technology - Other Topics; Materials Science; Metallurgy & Metallurgical Engineering GA 888KI UT WOS:000226372400051 ER PT J AU Zhao, XC Johnson, JK AF Zhao, XC Johnson, JK TI An effective potential for adsorption of polar molecules on graphite SO MOLECULAR SIMULATION LA English DT Article DE adsorption; polar molecules; graphite; graphite quadrupole moment ID CANONICAL MONTE-CARLO; QUADRUPOLE-MOMENTS; CARBON-DIOXIDE; SIMULATION; MIXTURES; SURFACE; MODEL; WATER; TRANSITION; METHANE AB Each carbon atom in the graphite crystal has a quadrupole moment due to the symmetry of the crystal. We show that these graphite quadrupoles, along with the polarizability of graphite, have a substantial effect on adsorption of strongly polar molecules. We present an approximate method for accounting for the change in the solid-fluid potential energy due to polar interactions with graphite. The potential function is integrated over the graphite surface using a truncated Fourier series, so that the resulting potential is analogous to the Steele 10-4-3 potential. The interactions included in this potential include dipole-induced dipole, dipole-quadrupole, and quadrupole-quadrupole interactions. Hence, the potential can be used for fluid molecules with dipole and/or quadrupole moments. Fluid-fluid multipole interactions can be computed with any model; but point multipoles must be used in the solid-fluid potential. The multipole solid-fluid potential is most accurate for nearly spherical molecules. C1 Univ Pittsburgh, Dept Chem & Petr Engn, Pittsburgh, PA 15261 USA. US DOE, Natl Energy Technol Lab, Pittsburgh, PA 15236 USA. RP Johnson, JK (reprint author), Univ Pittsburgh, Dept Chem & Petr Engn, Pittsburgh, PA 15261 USA. EM karlj@pitt.edu RI Johnson, Karl/E-9733-2013 OI Johnson, Karl/0000-0002-3608-8003 NR 38 TC 38 Z9 39 U1 1 U2 11 PU TAYLOR & FRANCIS LTD PI ABINGDON PA 4 PARK SQUARE, MILTON PARK, ABINGDON OX14 4RN, OXON, ENGLAND SN 0892-7022 J9 MOL SIMULAT JI Mol. Simul. PD JAN 15 PY 2005 VL 31 IS 1 BP 1 EP 10 DI 10.1080/0892702042000272889 PG 10 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 882EZ UT WOS:000225923100001 ER PT J AU Tran, CQ Peele, AG Roberts, A Nugent, KA Paterson, D McNulty, I AF Tran, CQ Peele, AG Roberts, A Nugent, KA Paterson, D McNulty, I TI Synchrotron beam coherence: a spatially resolved measurement SO OPTICS LETTERS LA English DT Article ID HARD X-RAYS; DIFFRACTION AB We report a precise and spatially resolved measurement of the complex degree of coherence of a one-dimensional 1.5-keV beam produced by a third-generation synchrotron source. The method of phase-space tomography is used, which requires only measurements of the x-ray intensity. We find that the field is statistically stationary to within experimental error, the correlations are very well approximated by a Gaussian distribution, and the measured coherence length is in excellent agreement with expectations. (C) 2005 Optical Society of America. C1 Univ Melbourne, Sch Phys, Melbourne, Vic 3010, Australia. Argonne Natl Lab, Adv Photon Source, Argonne, IL 60439 USA. RP Tran, CQ (reprint author), Univ Melbourne, Sch Phys, Melbourne, Vic 3010, Australia. EM keithan@unimelb.edu.au RI Roberts, Ann/C-3418-2011; Nugent, Keith/J-2699-2012; Tran, Chanh/M-7868-2015; Nugent, Keith/I-4154-2016 OI Roberts, Ann/0000-0003-4295-9730; Nugent, Keith/0000-0003-1522-8991; Nugent, Keith/0000-0002-4281-3478 NR 11 TC 17 Z9 17 U1 0 U2 5 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 JAN 15 PY 2005 VL 30 IS 2 BP 204 EP 206 DI 10.1364/OL.30.000204 PG 3 WC Optics SC Optics GA 886HW UT WOS:000226218500030 PM 15675714 ER PT J AU Baker, GA Johnson, JD AF Baker, GA Johnson, JD TI Perturbation theory calculation of the pressure for an electron-ion system (vol 265, pg 129, 1999) SO PHYSICA A-STATISTICAL MECHANICS AND ITS APPLICATIONS LA English DT Correction C1 Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. RP Baker, GA (reprint author), Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. EM gbj@viking.lanl.gov NR 1 TC 2 Z9 2 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0378-4371 J9 PHYSICA A JI Physica A PD JAN 15 PY 2005 VL 345 IS 3-4 BP 722 EP 724 DI 10.1016/j.physa.2004.08.005 PG 3 WC Physics, Multidisciplinary SC Physics GA 877NU UT WOS:000225578100032 ER PT J AU Fernandez, AM Dheree, N Turner, JA Martinez, AM Arriaga, LG Cano, U AF Fernandez, AM Dheree, N Turner, JA Martinez, AM Arriaga, LG Cano, U TI Photoelectrochemical characterization of the Cu(In,Ga)S-2 thin film prepared by evaporation SO SOLAR ENERGY MATERIALS AND SOLAR CELLS LA English DT Article DE chalcopyrite; CuIn1-xGaxS; physical evaporation; thin films AB Cu(In.Ga)S-2 chalcopyrite thin films have been characterized in order to determine the band edges potential position for photoelectrolysis water splitting. These values are correlated with the atomic composition of the samples. The characterization includes structural and atomic composition of the films. Sputtering/Sulphurization technique was used to prepare the films using different types of Cu-Ga and In targets. According to the capacitance measurements all of the films tested were p-type and the photoresponse technique shows that the band-gap values are between 1.38 and 1.74eV. We distinguish three type of samples, low, medium and high content of Ga in the films, and the band edges potential position values depend on the amount of Ga in the films and also these values shift more positive when the pH of solution increases. (C) 2004 Elsevier B.V. All rights reserved. C1 Univ Nacl Autonoma Mexico, Ctr Invest & Energia, Dept Mat Solares, Temixco, Morelos, Mexico. Florida Solar Energy Ctr, Cocoa, FL 32922 USA. Natl Renewable Energy Lab, Golden, CO 80401 USA. Inst Invest Elect Gerencia Energias No Convencion, Cuernavaca 62490, Morelos, Mexico. RP Fernandez, AM (reprint author), Univ Nacl Autonoma Mexico, Ctr Invest & Energia, Dept Mat Solares, Av Xochicalco S-N, Temixco, Morelos, Mexico. EM afm@cie.unam.mx NR 5 TC 14 Z9 14 U1 0 U2 11 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0927-0248 J9 SOL ENERG MAT SOL C JI Sol. Energy Mater. Sol. Cells PD JAN 15 PY 2005 VL 85 IS 2 BP 251 EP 259 DI 10.1016/j.solmat.2004.03.006 PG 9 WC Energy & Fuels; Materials Science, Multidisciplinary; Physics, Applied SC Energy & Fuels; Materials Science; Physics GA 875MP UT WOS:000225424800008 ER PT J AU Lin, L Lawrence, NS Thongngamdee, S Wang, J Lin, YH AF Lin, L Lawrence, NS Thongngamdee, S Wang, J Lin, YH TI Catalytic adsorptive stripping determination of trace chromium(VI) at the bismuth film electrode SO TALANTA LA English DT Article DE bismuth film electrode; chromium (VI); diethylenetriannnine pentaacetic acid (DTPA) adsorptive stripping voltammetry; square wave voltammetry ID VOLTAMMETRIC CONDITIONS; CARBON ELECTRODES AB A sensitive adsorptive stripping voltammetric protocol at a bismuth-coated glassy-carbon electrode for trace measurements of chromium (V I) in the presence of diethylenetriammine pentaacetic acid (DTPA) is described. The new protocol is based on accumulation of the Cr-DTPA complex at a preplated bismuth film electrode held at -0.80 V. followed by a negatively-going square-wave voltammetric waveform. Factors influencing the stripping performance including the film preparation, solution pH. DTPA and nitrate concentrations, deposition potential and deposition time, have been optimized. The resulting performance compares well with that observed for analogous measurements at mercury film electrodes. A preconcentration time of 7 min results in a detection limit of 0.3 nM Cr(VI) and after 2 min a relative standard deviation at 20 nM of 5.1% (n = 25). Applicability to river water samples is demonstrated. The attractive behavior of the new "mercury-free" chromium sensor holds great promise for on-site environmental and industrial monitoring of chromium (VI). Preliminary data in this direction using bismuth-coated screen-printed electrodes are encouraging (C) 2004 Elsevier B.V. All rights reserved. C1 New Mexico State Univ, Dept Chem & Biochem, Las Cruces, NM 88003 USA. Pacific NW Natl Lab, Richland, WA 99352 USA. RP Wang, J (reprint author), New Mexico State Univ, Dept Chem & Biochem, Las Cruces, NM 88003 USA. EM joewang@nmsu.edu RI Wang, Joseph/C-6175-2011; Lin, Yuehe/D-9762-2011 OI Lin, Yuehe/0000-0003-3791-7587 NR 13 TC 109 Z9 115 U1 3 U2 41 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0039-9140 J9 TALANTA JI Talanta PD JAN 15 PY 2005 VL 65 IS 1 BP 144 EP 148 DI 10.1016/j.talanta.2004.05.004 PG 5 WC Chemistry, Analytical SC Chemistry GA 874WQ UT WOS:000225381600021 PM 18969776 ER PT J AU Hart, LS Yannone, SM Naczki, C Orlando, JS Waters, SB Akman, SA Chen, DJ Ornelles, D Koumenis, C AF Hart, LS Yannone, SM Naczki, C Orlando, JS Waters, SB Akman, SA Chen, DJ Ornelles, D Koumenis, C TI The adenovirus E4orf6 protein inhibits DNA double strand break repair and radiosensitizes human tumor cells in an E1B-55K-independent manner SO JOURNAL OF BIOLOGICAL CHEMISTRY LA English DT Article ID KINASE CATALYTIC SUBUNIT; IN-VIVO; HISTONE H2AX; RADIATION SENSITIVITY; GENOMIC INSTABILITY; V(D)J RECOMBINATION; AUTOPHOSPHORYLATION; PHOSPHORYLATION; RADIOTHERAPY; EXPRESSION AB The adenoviral protein E4orf6 has been shown to inhibit both in vitro V(D)J recombination and adenoviral DNA concatenation, two processes that rely on cellular DNA double strand break repair (DSBR) proteins. Most of the known activities of E4orf6 during adenoviral infection require its interaction with another adenoviral protein, E1B-55K. Here we report that E4orf6, stably expressed in RKO human colorectal carcinoma cells or transiently expressed by adenoviral vector in U251 human glioblastoma cells, inhibits DSBR and induces significant radiosensitization in the absence of E1B-55K. Expression of a mutant form of E4orf6 (L245P) failed to radiosensitize RKO cells. E4orf6 reduced DSBR capacity in transfected and infected cells, as measured by sublethal DNA damage repair assay and phosphorylated H2AX (gamma-H2AX) levels, respectively. Consistent with the inhibitory effect of E4orf6 on DSBR, expression of wild-type but not mutant E4orf6 reduced recovery of a transfected, replicating reporter plasmid (pSP189) in 293 cells but did not increase the mutation frequency measured in the reporter plasmid. The kinase activity of DNA-PKcs (the DNA-dependent protein kinase catalytic subunit) toward heterologous substrates was not affected by expression of E4orf6; however, autophosphorylation of DNA-PKcs at Thr-2609 following ionizing radiation was prolonged in the presence of E4orf6 when compared with control-infected cells. Our results demonstrate for the first time that E4orf6 expression hinders the cellular DNA repair process in mammalian cells in the absence of E1B-55K or other adenoviral genes and suggest that viral-mediated delivery of E4orf6, combined with localized external beam radiation, could be a useful approach for the treatment of radioresistant solid tumors such as glioblastomas. C1 Wake Forest Univ, Sch Med, Sect Radiat Biol, Dept Radiat Oncol, Winston Salem, NC 27157 USA. Wake Forest Univ, Sch Med, Dept Canc Biol, Winston Salem, NC 27157 USA. Wake Forest Univ, Sch Med, Dept Neurosurg, Winston Salem, NC 27157 USA. Wake Forest Univ, Sch Med, Dept Microbiol & Immunol, Winston Salem, NC 27157 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Life Sci, Berkeley, CA 94720 USA. RP Koumenis, C (reprint author), Wake Forest Univ, Sch Med, Sect Radiat Biol, Dept Radiat Oncol, NRC 412,Med Ctr Blvd, Winston Salem, NC 27157 USA. EM ckoumeni@wfubmc.edu RI Koumenis, Constantinos/B-2002-2008; Yannone, Steven/G-1927-2011 FU NCI NIH HHS [CA77342]; NIAID NIH HHS [T32 AI07401] NR 38 TC 34 Z9 34 U1 0 U2 0 PU AMER SOC BIOCHEMISTRY MOLECULAR BIOLOGY INC PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814-3996 USA SN 0021-9258 J9 J BIOL CHEM JI J. Biol. Chem. PD JAN 14 PY 2005 VL 280 IS 2 BP 1474 EP 1481 DI 10.1074/jbc.M409934200 PG 8 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA 885ZF UT WOS:000226195200076 PM 15507430 ER PT J AU Suvorova, A Dmitriev, A Chao, JK Thomsen, M Yang, YH AF Suvorova, A Dmitriev, A Chao, JK Thomsen, M Yang, YH TI Necessary conditions for geosynchronous magnetopause crossings SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID WIND DYNAMIC PRESSURE; INTERPLANETARY MAGNETIC-FIELD; SOLAR-WIND; DAYSIDE MAGNETOPAUSE; BOW SHOCK; SHAPE; MAGNETOSPHERE; MODELS; ORBIT; PLASMA AB [1] The International Solar Terrestrial Physics database of the magnetic measurements on GOES and plasma measurements on Los Alamos National Laboratory (LANL) geosynchronous satellites is used for selection of 169 case events containing 638 geosynchronous magnetopause crossings (GMCs) in 1995 to 2001. The GMCs and magnetosheath intervals associated with them are identified using advanced methods that take into account ( 1) strong deviation of the magnetic field measured by GOES from the magnetospheric field, ( 2) high correlation between the GOES magnetic field and interplanetary magnetic field ( IMF), and ( 3) substantial increase of the midenergy ion and electron fluxes measured by LANL. Accurate determination of the upstream solar wind conditions for the GMCs is performed using correlation of geomagnetic activity (Dst (SYM-H) index) with the upstream solar wind pressure. The location of the GMCs and associated upstream solar wind conditions are ordered in an aberrated GSM coordinate system (aGSM) with X-axis directed along the solar wind flow. In the selected data set of GMCs the solar wind total pressure Psw varies up to 100 nPa and the southward IMF Bz reaches 60 nT. We study the conditions necessary for geosynchronous magnetopause crossings using scatterplots of the GMCs in the coordinate space of Psw versus Bz. In such a representation the upstream solar wind conditions show a sharp envelope boundary beyond which no GMCs are observed. The boundary has two straight horizontal branches where Bz does not influence the magnetopause location. The first branch is located in the range of Psw = 21 nPa for large positive Bz and is associated with a regime of pressure balance. The second branch asymptotically approaches the range of Psw = 4.8 nPa under strong negative Bz, and it is associated with a regime in which the Bz influence saturates. The intermediate region of the boundary ranges from moderate negative to moderate positive IMF Bz and can be well approximated by a hyperbolic tangent function. We interpret the envelope boundary as a range of necessary upstream solar wind conditions required for the magnetopause to reach geosynchronous orbit at its closest approach to the Earth ( its "perigee'' location). C1 Natl Cent Univ, Inst Space Sci, Chungli 320, Taiwan. Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Moscow MV Lomonosov State Univ, Skobeltsyn Inst Nucl Phys, Moscow, Russia. RP Suvorova, A (reprint author), Natl Cent Univ, Inst Space Sci, Chungli 320, Taiwan. EM dalex@jupiter.ss.ncu.edu.tw; alla@dec1.npi.msu.su; jkchao@jupiter.ss.ncu.edu.tw; mthomsen@lanl.gov; yhyang@jupiter.ss.ncu.edu.tw RI Suvorova, Alla/J-4174-2012; Dmitriev, Alexei/J-6161-2012 OI Suvorova, Alla/0000-0002-5146-0846; Dmitriev, Alexei/0000-0001-8038-251X NR 48 TC 19 Z9 19 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 JAN 14 PY 2005 VL 110 IS A1 AR A01206 DI 10.1029/2003JA010079 PG 17 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 890YU UT WOS:000226548500001 ER PT J AU Weygand, JM Kivelson, MG Khurana, KK Schwarzl, HK Thompson, SM McPherron, RL Balogh, A Kistler, LM Goldstein, ML Borovsky, J Roberts, DA AF Weygand, JM Kivelson, MG Khurana, KK Schwarzl, HK Thompson, SM McPherron, RL Balogh, A Kistler, LM Goldstein, ML Borovsky, J Roberts, DA TI Plasma sheet turbulence observed by cluster II SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID SELF-ORGANIZED CRITICALITY; INTERPLANETARY MAGNETIC-FIELD; SOLAR-WIND; MULTIFRACTAL STRUCTURE; INTERMITTENT TURBULENCE; MAGNETOHYDRODYNAMIC TURBULENCE; RECURRENT STREAMS; SCALE VELOCITY; FLUCTUATIONS; DISSIPATION AB [1] Cluster fluxgate magnetometer (FGM) and ion spectrometer (CIS) data are employed to analyze magnetic field fluctuations within the plasma sheet during passages through the magnetotail region in the summers of 2001 and 2002 and, in particular, to look for characteristics of magnetohydrodynamic (MHD) turbulence. Power spectral indices determined from power spectral density functions are on average larger than Kolmogorov's theoretical value for fluid turbulence as well as Kraichnan's theoretical value for MHD plasma turbulence. Probability distribution functions of the magnetic fluctuations show a scaling law over a large range of temporal scales with non-Gaussian distributions at small dissipative scales and inertial scales and more Gaussian distribution at large driving scales. Furthermore, a multifractal analysis of the magnetic field components shows scaling behavior in the inertial range of the fluctuations from about 20 s to 13 min for moments through the fifth order. Both the scaling behavior of the probability distribution functions and the multifractal structure function suggest that intermittent turbulence is present within the plasma sheet. The unique multispacecraft aspect and fortuitous spacecraft spacing allow us to examine the turbulent eddy scale sizes. Dynamic autocorrelation and cross correlation analysis of the magnetic field components allow us to determine that eddy scale sizes fit within the plasma sheet. These results suggest that magnetic field turbulence is occurring within the plasma sheet resulting in turbulent energy dissipation. C1 Univ Calif Los Angeles, Inst Geophys & Planetary Phys, Los Angeles, CA 90095 USA. Univ London Imperial Coll Sci Technol & Med, London SW7 2BZ, England. Univ New Hampshire, Inst Study Earth Oceans & Space, Durham, NH 03824 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Univ Calif Los Angeles, Inst Geophys & Planetary Phys, Los Angeles, CA 90095 USA. EM jweygand@igpp.ucla.edu RI Roberts, Dana/D-4625-2012; Kivelson, Margaret/I-9019-2012; Goldstein, Melvyn/B-1724-2008 OI Kivelson, Margaret/0000-0003-3859-8581; NR 45 TC 69 Z9 69 U1 1 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-9380 EI 2169-9402 J9 J GEOPHYS RES-SPACE JI J. Geophys. Res-Space Phys. PD JAN 14 PY 2005 VL 110 IS A1 AR A01205 DI 10.1029/2004JA010581 PG 29 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 890YU UT WOS:000226548500003 ER PT J AU Tran, CQ Chantler, CT Barnea, Z de Jonge, MD Dhal, BB Chung, CTY Paterson, D Wang, J AF Tran, CQ Chantler, CT Barnea, Z de Jonge, MD Dhal, BB Chung, CTY Paterson, D Wang, J TI Measurement of the x-ray mass attenuation coefficient of silver using the x-ray-extended range technique SO JOURNAL OF PHYSICS B-ATOMIC MOLECULAR AND OPTICAL PHYSICS LA English DT Article ID ATOMIC FORM-FACTORS; CROSS-SECTIONS; PHOTOELECTRIC ABSORPTION; INTERNATIONAL-UNION; SCATTERING; SILICON; TABULATION; GERMANIUM; ENERGIES; ELEMENTS AB We used the x-ray-extended range technique to measure the x-ray mass attenuation coefficients of silver in the 15-50 keV energy range with a level of uncertainty between 0.27% and 0.4% away from the K-edge. The imaginary part of the atomic form factor of silver was derived by subtracting the scattering component from the measured total mass attenuation coefficients. Discrepancies between the measured mass attenuation coefficients and alternative theoretical predictions are discussed. C1 Univ Melbourne, Sch Phys, Melbourne, Vic 3010, Australia. Argonne Natl Lab, XOR, APS, Argonne, IL 60439 USA. RP Tran, CQ (reprint author), Univ Melbourne, Sch Phys, Melbourne, Vic 3010, Australia. EM tran@physics.unimelb.edu.au RI de Jonge, Martin/C-3400-2011; Chantler, Christopher/D-4744-2013; Tran, Chanh/M-7868-2015 OI Chantler, Christopher/0000-0001-6608-0048; NR 46 TC 34 Z9 34 U1 0 U2 4 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0953-4075 J9 J PHYS B-AT MOL OPT JI J. Phys. B-At. Mol. Opt. Phys. PD JAN 14 PY 2005 VL 38 IS 1 BP 89 EP 107 DI 10.1088/0953-4075/38/1/009 PG 19 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA 898AE UT WOS:000227047200014 ER PT J AU Hu, SX Colgan, J Collins, LA AF Hu, SX Colgan, J Collins, LA TI Triple-differential cross-sections for two-photon double ionization of He near threshold SO JOURNAL OF PHYSICS B-ATOMIC MOLECULAR AND OPTICAL PHYSICS LA English DT Article ID PHOTO-DOUBLE-IONIZATION; DOUBLE PHOTOIONIZATION; ABOVE-THRESHOLD; HELIUM; EXCITATION; SINGLE; LASER AB Complete two-photon break-up of He near threshold has been investigated by solving the time-dependent closing-coupling equations on a numerical lattice. We have obtained good agreement for the total double ionization cross-section with previous theoretical results. The triple-differential cross-sections exhibit interesting features as the two-photon energy approaches the threshold of double ionization. We found that two-electron ejection with equal energy sharing is most probable near the two-photon threshold, in contrast to the case away from threshold, where ejection with large unequal energy sharings is most probable. C1 Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. RP Hu, SX (reprint author), Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. RI Hu, Suxing/A-1265-2007; OI Hu, Suxing/0000-0003-2465-3818; Colgan, James/0000-0003-1045-3858 NR 27 TC 69 Z9 69 U1 0 U2 3 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0953-4075 J9 J PHYS B-AT MOL OPT JI J. Phys. B-At. Mol. Opt. Phys. PD JAN 14 PY 2005 VL 38 IS 1 BP L35 EP L45 DI 10.1088/0953-4075/38/1/L05 PG 11 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA 898AE UT WOS:000227047200005 ER PT J AU Airapetian, A Akopov, N Akopov, Z Amarian, M Andrus, A Aschenauer, EC Augustyniak, W Avakian, R Avetissian, A Avetissian, E Bacchetta, A Bailey, P Balin, D Beckmann, M Belostotski, S Bianchi, N Blok, HP Bottcher, H Borissov, A Borysenko, A Bouwhuis, M Brull, A Bryzgalov, V Capitani, GP Cappiluppi, M Chen, T Ciullo, G Contalbrigo, M Dalpiaz, PF De Leo, R Demey, M De Nardo, L De Sanctis, E Devitsin, E Di Nezza, P Duren, M Ehrenfried, M Elalaoui-Moulay, A Elbakian, G Ellinghaus, F Elschenbroich, U Fabbri, R Fantoni, A Fechtchenko, A Felawka, L Frullani, S Gapienko, G Gapienko, V Garibaldi, F Garrow, K Gavrilov, G Gharibyan, V Grebeniouk, O Gregor, IM Hadjidakis, C Hafidi, K Hartig, M Hasch, D Henoch, M Hesselink, WHA Hillenbrand, A Hoek, M Holler, Y Hommez, B Hristova, I Iarygin, G Ilyichev, A Ivanilov, A Izotov, A Jackson, HE Jgoun, A Kaiser, R Kinney, E Kisselev, A Kobayashi, T Kopytin, M Korotkov, V Kozlov, V Krauss, B Krivokhijine, VG Lagamba, L Lapikas, L Laziev, A Lenisa, P Liebing, P Linden-Levy, LA Lorenzon, W Lu, H Lu, J Lu, S Ma, BQ Maiheu, B Makins, NCR Mao, Y Marianski, B Marukyan, H Masoli, F Mexner, V Meyners, N Michler, T Mikloukho, O Miller, CA Miyachi, Y Muccifora, V Nagaitsev, A Nappi, E Naryshkin, Y Nass, A Negodaev, M Nowak, WD Oganessyan, K Ohsuga, H Osborne, A Pickert, N Potterveld, DH Raithel, M Reggiani, D Reimer, PE Reischl, A Reolon, AR Riedl, C Rith, K Rosner, G Rostomyan, A Rubacek, L Rubin, J Ryckbosch, D Salomatin, Y Sanjiev, I Savin, I Schafer, A Schill, C Schnell, G Schuler, KP Seele, J Seidl, R Seitz, B Shanidze, R Shearer, C Shibata, TA Shutov, V Sinram, K Sommer, W Stancari, M Statera, M Steffens, E Steijger, JJM Stenzel, H Stewart, J Stinzing, F Tait, P Tanaka, H Taroian, S Tchuiko, B Terkulov, A Trzcinski, A Tytgat, M Vandenbroucke, A van der Nat, PB van der Steenhoven, G van Haarlem, Y Vetterli, MC Vikhrov, V Vincter, MG Vogel, C Volmer, J Wang, S Wendland, J Wilbert, J Smit, GY Ye, Y Ye, Z Yen, S Zihlmann, B Zupranski, P AF Airapetian, A Akopov, N Akopov, Z Amarian, M Andrus, A Aschenauer, EC Augustyniak, W Avakian, R Avetissian, A Avetissian, E Bacchetta, A Bailey, P Balin, D Beckmann, M Belostotski, S Bianchi, N Blok, HP Bottcher, H Borissov, A Borysenko, A Bouwhuis, M Brull, A Bryzgalov, V Capitani, GP Cappiluppi, M Chen, T Ciullo, G Contalbrigo, M Dalpiaz, PF De Leo, R Demey, M De Nardo, L De Sanctis, E Devitsin, E Di Nezza, P Duren, M Ehrenfried, M Elalaoui-Moulay, A Elbakian, G Ellinghaus, F Elschenbroich, U Fabbri, R Fantoni, A Fechtchenko, A Felawka, L Frullani, S Gapienko, G Gapienko, V Garibaldi, F Garrow, K Gavrilov, G Gharibyan, V Grebeniouk, O Gregor, IM Hadjidakis, C Hafidi, K Hartig, M Hasch, D Henoch, M Hesselink, WHA Hillenbrand, A Hoek, M Holler, Y Hommez, B Hristova, I Iarygin, G Ilyichev, A Ivanilov, A Izotov, A Jackson, HE Jgoun, A Kaiser, R Kinney, E Kisselev, A Kobayashi, T Kopytin, M Korotkov, V Kozlov, V Krauss, B Krivokhijine, VG Lagamba, L Lapikas, L Laziev, A Lenisa, P Liebing, P Linden-Levy, LA Lorenzon, W Lu, H Lu, J Lu, S Ma, BQ Maiheu, B Makins, NCR Mao, Y Marianski, B Marukyan, H Masoli, F Mexner, V Meyners, N Michler, T Mikloukho, O Miller, CA Miyachi, Y Muccifora, V Nagaitsev, A Nappi, E Naryshkin, Y Nass, A Negodaev, M Nowak, WD Oganessyan, K Ohsuga, H Osborne, A Pickert, N Potterveld, DH Raithel, M Reggiani, D Reimer, PE Reischl, A Reolon, AR Riedl, C Rith, K Rosner, G Rostomyan, A Rubacek, L Rubin, J Ryckbosch, D Salomatin, Y Sanjiev, I Savin, I Schafer, A Schill, C Schnell, G Schuler, KP Seele, J Seidl, R Seitz, B Shanidze, R Shearer, C Shibata, TA Shutov, V Sinram, K Sommer, W Stancari, M Statera, M Steffens, E Steijger, JJM Stenzel, H Stewart, J Stinzing, F Tait, P Tanaka, H Taroian, S Tchuiko, B Terkulov, A Trzcinski, A Tytgat, M Vandenbroucke, A van der Nat, PB van der Steenhoven, G van Haarlem, Y Vetterli, MC Vikhrov, V Vincter, MG Vogel, C Volmer, J Wang, S Wendland, J Wilbert, J Smit, GY Ye, Y Ye, Z Yen, S Zihlmann, B Zupranski, P CA HERMES Collaboration TI Single-spin asymmetries in semi-inclusive deep-inelastic scattering on a transversely polarized hydrogen target SO PHYSICAL REVIEW LETTERS LA English DT Article ID FINAL-STATE INTERACTIONS; PARTON DISTRIBUTIONS; DEUTERIUM TARGET; AZIMUTHAL ASYMMETRIES; DRELL-YAN; HERMES; FRAGMENTATION; ELECTROPRODUCTION; CONSTITUENTS; QUARKS AB Single-spin asymmetries for semi-inclusive electroproduction of charged pions in deep-inelastic scattering of positrons are measured for the first time with transverse target polarization. The asymmetry depends on the azimuthal angles of both the pion (phi) and the target spin axis (phi(S)) about the virtual-photon direction and relative to the lepton scattering plane. The extracted Fourier component (pi)(UT) is a signal of the previously unmeasured quark transversity distribution, in conjunction with the Collins fragmentation function, also unknown. The component (pi)(UT) arises from a correlation between the transverse polarization of the target nucleon and the intrinsic transverse momentum of quarks, as represented by the previously unmeasured Sivers distribution function. Evidence for both signals is observed, but the Sivers asymmetry may be affected by exclusive vector meson production. C1 Univ Michigan, Randall Lab Phys, Ann Arbor, MI 48109 USA. Univ Alberta, Dept Phys, Edmonton, AB T6G 2J1, Canada. Argonne Natl Lab, Div Phys, Argonne, IL 60439 USA. Ist Nazl Fis Nucl, Sez Bari, I-70124 Bari, Italy. Peking Univ, Sch Phys, Beijing 100871, Peoples R China. Univ Sci & Technol China, Dept Modern Phys, Hefei 230026, Anhui, Peoples R China. Univ Colorado, Phys Nucl Lab, Boulder, CO 80309 USA. DESY, D-22603 Hamburg, Germany. DESY, D-15738 Zeuthen, Germany. Joint Inst Nucl Res, Dubna 141980, Russia. Univ Erlangen Nurnberg, Inst Phys, D-91058 Erlangen, Germany. Ist Nazl Fis Nucl, Sez Ferrara, I-44100 Ferrara, Italy. Univ Ferrara, Dipartimento Fis, I-44100 Ferrara, Italy. Ist Nazl Fis Nucl, Lab Nazl Frascati, I-00044 Frascati, Italy. Univ Ghent, Dept Subatom & Radiat Phys, B-9000 Ghent, Belgium. Univ Giessen, Inst Phys, D-35392 Giessen, Germany. Univ Glasgow, Dept Phys & Astron, Glasgow G12 8QQ, Lanark, Scotland. Univ Illinois, Dept Phys, Urbana, IL 61801 USA. MIT, Nucl Sci Lab, Cambridge, MA 02139 USA. PN Lebedev Phys Inst, Moscow 117924, Russia. Natl Inst Nucl & High Energy Phys, NL-1009 DB Amsterdam, Netherlands. Petersburg Nucl Phys Inst, Gatchina 188350, Russia. Inst High Energy Phys, Protvino 142281, Moscow Region, Russia. Univ Regensburg, Inst Theoret Phys, D-93040 Regensburg, Germany. Ist Super Sanita, Phys Lab, I-00161 Rome, Italy. Ist Nazl Fis Nucl, Sez Roma 1, Grp Sanita, Rome, Italy. Simon Fraser Univ, Dept Phys, Burnaby, BC V5A 1S6, Canada. TRIUMF, Vancouver, BC V6T 2A3, Canada. Tokyo Inst Technol, Dept Phys, Tokyo 152, Japan. Free Univ Amsterdam, Dept Phys & Astron, NL-1081 HV Amsterdam, Netherlands. Andrzej Soltan Inst Nucl Studies, PL-00689 Warsaw, Poland. Yerevan Phys Inst, Yerevan 375036, Armenia. RP Airapetian, A (reprint author), Univ Michigan, Randall Lab Phys, Ann Arbor, MI 48109 USA. RI Bacchetta, Alessandro/F-3199-2012; Gavrilov, Gennady/C-6260-2013; Reimer, Paul/E-2223-2013; Negodaev, Mikhail/A-7026-2014; El Alaoui, Ahmed/B-4638-2015; Kozlov, Valentin/M-8000-2015; Terkulov, Adel/M-8581-2015; OI Bacchetta, Alessandro/0000-0002-8824-8355; Lagamba, Luigi/0000-0002-0233-9812; Hoek, Matthias/0000-0002-1893-8764 NR 40 TC 455 Z9 455 U1 1 U2 17 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 EI 1079-7114 J9 PHYS REV LETT JI Phys. Rev. Lett. PD JAN 14 PY 2005 VL 94 IS 1 AR 012002 DI 10.1103/PhysRevLett.94.012002 PG 6 WC Physics, Multidisciplinary SC Physics GA 887LQ UT WOS:000226308000020 PM 15698069 ER PT J AU Aubert, B Barate, R Boutigny, D Couderc, F Gaillard, JM Hicheur, A Karyotakis, Y Lees, JP Tisserand, V Zghiche, A Palano, A Pompili, A Chen, JC Qi, ND Rong, G Wang, P Zhu, YS Eigen, G Ofte, I Stugu, B Abrams, GS Borgland, AW Breon, AB Brown, DN Button-Shafer, J Cahn, RN Charles, E Day, CT Gill, MS Gritsan, AV Groysman, Y Jacobsen, RG Kadel, RW Kadyk, J Kerth, LT Kolomensky, YG Kukartsev, G Lynch, G Mir, LM Oddone, PJ Orimoto, TJ Pripstein, M Roe, NA Ronan, MT Shelkov, VG Wenzel, WA Barrett, M Ford, KE Harrison, TJ Hart, AJ Hawkes, CM Morgan, SE Watson, AT Fritsch, M Goetzen, K Held, T Koch, H Lewandowski, B Pelizaeus, M Steinke, M Boyd, JT Chevalier, N Cottingham, WN Kelly, MP Latham, TE Wilson, FF Cuhadar-Donszelmann, T Hearty, C Knecht, NS Mattison, TS McKenna, JA Thiessen, D Khan, A Kyberd, P Teodorescu, L Blinov, AE Blinov, VE Druzhinin, VP Golubev, VB Ivanchenko, VN Kravchenko, EA Onuchin, AP Serednyakov, SI Skovpen, YI Solodov, EP Yushkov, AN Best, D Bruinsma, M Chao, M Eschrich, I Kirkby, D Lankford, AJ Mandelkern, M Mommsen, RK Roethel, W Stoker, DP Buchanan, C Hartfiel, BL Foulkes, SD Gary, JW Shen, BC Wang, K del Re, D Hadavand, HK Hill, EJ MacFarlane, DB Paar, HP Rahatlou, S Sharma, V Berryhill, JW Campagnari, C Dahmes, B Long, O Lu, A Mazur, MA Richman, JD Verkerke, W Beck, TW Eisner, AM Heusch, CA Kroseberg, J Lockman, WS Nesom, G Schalk, T Schumm, BA Seiden, A Spradlin, P Williams, DC Wilson, MG Albert, J Chen, E Dubois-Felsmann, GP Dvoretskii, A Hitlin, DG Narsky, I Piatenko, T Porter, FC Ryd, A Samuel, A Yang, S Jayatilleke, S Mancinelli, G Meadows, BT Sokoloff, MD Abe, T Blanc, F Bloom, P Chen, S Ford, WT Nauenberg, U Olivas, A Rankin, P Smith, JG Zhang, J Zhang, L Chen, A Harton, JL Soffer, A Toki, WH Wilson, RJ Zeng, QL Altenburg, D Brandt, T Brose, J Dickopp, M Feltresi, E Hauke, A Lacker, HM Muller-Pfefferkorn, R Nogowski, R Otto, S Petzold, A Schubert, J Schubert, KR Schwierz, R Spaan, B Sundermann, JE Bernard, D Bonneaud, GR Brochard, F Grenier, P Schrenk, S Thiebaux, C Vasileiadis, G Verderi, M Bard, DJ Clark, PJ Lavin, D Muheim, F Playfer, S Xie, Y Andreotti, M Azzolini, V Bettoni, D Bozzi, C Calabrese, R Cibinetto, G Luppi, E Negrini, M Piemontese, L Sarti, A Treadwell, E Anulli, F Baldini-Ferroli, R Calcaterra, A de Sangro, R Finocchiaro, G Patteri, P Peruzzi, IM Piccolo, M Zallo, A Buzzo, A Capra, R Contri, R Crosetti, G Lo Vetere, M Macri, M Monge, MR Passaggio, S Patrignani, C Robutti, E Santroni, A Tosi, S Bailey, S Brandenburg, G Chaisanguanthum, KS Morii, M Won, E Dubitzky, RS Langenegger, U Bhimji, W Bowerman, DA Dauncey, PD Egede, U Gaillard, JR Morton, GW Nash, JA Nikolich, MB Taylor, GP Charles, MJ Grenier, GJ Mallik, U Cochran, J Crawley, HB Lamsa, J Meyer, WT Prell, S Rosenberg, EI Rubin, AE Yi, J Biasini, M Covarelli, R Pioppi, M Davier, M Giroux, X Grosdidier, G Hocker, A Laplace, S Le Diberder, F Lepeltier, V Lutz, AM Petersen, TC Plaszczynski, S Schune, MH Tantot, L Wormser, G Cheng, CH Lange, DJ Simani, MC Wright, DM Bevan, AJ Chavez, CA Coleman, JP Forster, IJ Fry, JR Gabathuler, E Gamet, R Hutchcroft, DE Parry, RJ Payne, DJ Sloane, RJ Touramanis, C Back, JJ Cormack, CM Harrison, PF Di Lodovico, F Mohanty, GB Brown, CL Cowan, G Flack, RL Flaecher, HU Green, MG Jackson, PS McMahon, TR Ricciardi, S Salvatore, F Winter, MA Brown, D Davis, CL Allison, J Barlow, NR Barlow, RJ Hart, PA Hodgkinson, MC Lafferty, GD Lyon, AJ Williams, JC Farbin, A Hulsbergen, WD Jawahery, A Kovalskyi, D Lae, CK Lillard, V Roberts, DA Blaylock, G Dallapiccola, C Flood, KT Hertzbach, SS Kofler, R Koptchev, VB Moore, TB Saremi, S Staengle, H Willocq, S Cowan, R Sciolla, G Sekula, SJ Taylor, F Yamamoto, RK Mangeol, DJJ Patel, PM Robertson, SH Lazzaro, A Lombardo, V Palombo, F Bauer, JM Cremaldi, L Eschenburg, V Godang, R Kroeger, R Reidy, J Sanders, DA Summers, DJ Zhao, HW Brunet, S Cote, D Taras, P Nicholson, H Cavallo, N Fabozzi, F Gatto, C Lista, L Monorchio, D Paolucci, P Piccolo, D Sciacca, C Baak, M Bulten, H Raven, G Snoek, HL Wilden, L Jessop, CP LoSecco, JM Allmendinger, T Gan, KK Honscheid, K Hufnagel, D Kagan, H Kass, R Pulliam, T Rahimi, AM Ter-Antonyan, R Wong, QK Brau, J Frey, R Igonkina, O Potter, CT Sinev, NB Strom, D Torrence, E Colecchia, F Dorigo, A Galeazzi, F Margoni, M Morandin, M Posocco, M Rotondo, M Simonetto, F Stroili, R Tiozzo, G Voci, C Benayoun, M Briand, H Chauveau, J David, P de la Vaissiere, C Buono, LD Hamon, O John, MJJ Leruste, P Malcles, J Ocariz, J Pivk, M Roos, L T'Jampens, S Therin, G Manfredi, PF Re, V Behera, PK Gladney, L Guo, QH Panetta, J Angelini, C Batignani, G Bettarini, S Bondioli, M Bucci, F Calderini, G Carpinelli, M Forti, F Giorgi, MA Lusiani, A Marchiori, G Martinez-Vidal, F Morganti, M Neri, N Paoloni, E Rama, M Rizzo, G Sandrelli, F Walsh, J Haire, M Judd, D Paick, K Wagoner, DE Danielson, N Elmer, P Lau, YP Lu, C Miftakov, V Olsen, J Smith, AJS Telnov, AV Bellini, F Cavoto, G Faccini, R Ferrarotto, F Ferroni, F Gaspero, M Li Gioi, L Mazzoni, MA Morganti, S Pierini, M Piredda, G Tehrani, FS Voena, C Christ, S Wagner, G Waldi, R Adye, T De Groot, N Franek, B Geddes, NI Gopal, GP Olaiya, EO Aleksan, R Emery, S Gaidot, A Ganzhur, SF Giraud, PF de Monchenault, GH Kozanecki, W Legendre, M London, GW Mayer, B Schott, G Vasseur, G Yeche, C Zito, M Purohit, MV Weidemann, AW Wilson, JR Yumiceva, FX Aston, D Bartoldus, R Berger, N Boyarski, AM Buchmueller, OL Claus, R Convery, MR Cristinziani, M De Nardo, G Dong, D Dorfan, J Dujmic, D Dunwoodie, W Elsen, EE Fan, S Field, RC Glanzman, T Gowdy, SJ Hadig, T Halyo, V Hast, C Hryn'ova, T Innes, WR Kelsey, MH Kim, P Kocian, ML Leith, DWGS Libby, J Luitz, S Luth, V Lynch, HL Marsiske, H Messner, R Muller, DR O'Grady, CP Ozcan, VE Perazzo, A Perl, M Petrak, S Ratcliff, BN Roodman, A Salnikov, AA Schindler, RH Schwiening, J Simi, G Snyder, A Soha, A Stelzer, J Su, D Sullivan, MK Va'vra, J Wagner, SR Weaver, M Weinstein, AJR Wisniewski, WJ Wittgen, M Wright, DH Yarritu, AK Young, CC Burchat, PR Edwards, AJ Meyer, TI Petersen, BA Roat, C Ahmed, S Alam, MS Ernst, JA Saeed, MA Saleem, M Wappler, FR Bugg, W Krishnamurthy, M Spanier, SM Eckmann, R Kim, H Ritchie, JL Satpathy, A Schwitters, RF Izen, JM Kitayama, I Lou, XC Ye, S Bianchi, F Bona, M Gallo, F Gamba, D Bosisio, L Cartaro, C Cossutti, F Della Ricca, G Dittongo, S Grancagnolo, S Lanceri, L Poropat, P Vitale, L Vuagnin, G Panvini, RS Banerjee, S Brown, CM Fortin, D Jackson, PD Kowalewski, R Roney, JM Sobie, RJ Band, HR Cheng, B Dasu, S Datta, M Eichenbaum, AM Graham, M Hollar, JJ Johnson, JR Kutter, PE Li, H Liu, R Mihalyi, A Mohapatra, AK Pan, Y Prepost, R Tan, P von Wimmersperg-Toeller, JH Wu, J Wu, SL Yu, Z Greene, MG Neal, H AF Aubert, B Barate, R Boutigny, D Couderc, F Gaillard, JM Hicheur, A Karyotakis, Y Lees, JP Tisserand, V Zghiche, A Palano, A Pompili, A Chen, JC Qi, ND Rong, G Wang, P Zhu, YS Eigen, G Ofte, I Stugu, B Abrams, GS Borgland, AW Breon, AB Brown, DN Button-Shafer, J Cahn, RN Charles, E Day, CT Gill, MS Gritsan, AV Groysman, Y Jacobsen, RG Kadel, RW Kadyk, J Kerth, LT Kolomensky, YG Kukartsev, G Lynch, G Mir, LM Oddone, PJ Orimoto, TJ Pripstein, M Roe, NA Ronan, MT Shelkov, VG Wenzel, WA Barrett, M Ford, KE Harrison, TJ Hart, AJ Hawkes, CM Morgan, SE Watson, AT Fritsch, M Goetzen, K Held, T Koch, H Lewandowski, B Pelizaeus, M Steinke, M Boyd, JT Chevalier, N Cottingham, WN Kelly, MP Latham, TE Wilson, FF Cuhadar-Donszelmann, T Hearty, C Knecht, NS Mattison, TS McKenna, JA Thiessen, D Khan, A Kyberd, P Teodorescu, L Blinov, AE Blinov, VE Druzhinin, VP Golubev, VB Ivanchenko, VN Kravchenko, EA Onuchin, AP Serednyakov, SI Skovpen, YI Solodov, EP Yushkov, AN Best, D Bruinsma, M Chao, M Eschrich, I Kirkby, D Lankford, AJ Mandelkern, M Mommsen, RK Roethel, W Stoker, DP Buchanan, C Hartfiel, BL Foulkes, SD Gary, JW Shen, BC Wang, K del Re, D Hadavand, HK Hill, EJ MacFarlane, DB Paar, HP Rahatlou, S Sharma, V Berryhill, JW Campagnari, C Dahmes, B Long, O Lu, A Mazur, MA Richman, JD Verkerke, W Beck, TW Eisner, AM Heusch, CA Kroseberg, J Lockman, WS Nesom, G Schalk, T Schumm, BA Seiden, A Spradlin, P Williams, DC Wilson, MG Albert, J Chen, E Dubois-Felsmann, GP Dvoretskii, A Hitlin, DG Narsky, I Piatenko, T Porter, FC Ryd, A Samuel, A Yang, S Jayatilleke, S Mancinelli, G Meadows, BT Sokoloff, MD Abe, T Blanc, F Bloom, P Chen, S Ford, WT Nauenberg, U Olivas, A Rankin, P Smith, JG Zhang, J Zhang, L Chen, A Harton, JL Soffer, A Toki, WH Wilson, RJ Zeng, QL Altenburg, D Brandt, T Brose, J Dickopp, M Feltresi, E Hauke, A Lacker, HM Muller-Pfefferkorn, R Nogowski, R Otto, S Petzold, A Schubert, J Schubert, KR Schwierz, R Spaan, B Sundermann, JE Bernard, D Bonneaud, GR Brochard, F Grenier, P Schrenk, S Thiebaux, C Vasileiadis, G Verderi, M Bard, DJ Clark, PJ Lavin, D Muheim, F Playfer, S Xie, Y Andreotti, M Azzolini, V Bettoni, D Bozzi, C Calabrese, R Cibinetto, G Luppi, E Negrini, M Piemontese, L Sarti, A Treadwell, E Anulli, F Baldini-Ferroli, R Calcaterra, A de Sangro, R Finocchiaro, G Patteri, P Peruzzi, IM Piccolo, M Zallo, A Buzzo, A Capra, R Contri, R Crosetti, G Lo Vetere, M Macri, M Monge, MR Passaggio, S Patrignani, C Robutti, E Santroni, A Tosi, S Bailey, S Brandenburg, G Chaisanguanthum, KS Morii, M Won, E Dubitzky, RS Langenegger, U Bhimji, W Bowerman, DA Dauncey, PD Egede, U Gaillard, JR Morton, GW Nash, JA Nikolich, MB Taylor, GP Charles, MJ Grenier, GJ Mallik, U Cochran, J Crawley, HB Lamsa, J Meyer, WT Prell, S Rosenberg, EI Rubin, AE Yi, J Biasini, M Covarelli, R Pioppi, M Davier, M Giroux, X Grosdidier, G Hocker, A Laplace, S Le Diberder, F Lepeltier, V Lutz, AM Petersen, TC Plaszczynski, S Schune, MH Tantot, L Wormser, G Cheng, CH Lange, DJ Simani, MC Wright, DM Bevan, AJ Chavez, CA Coleman, JP Forster, IJ Fry, JR Gabathuler, E Gamet, R Hutchcroft, DE Parry, RJ Payne, DJ Sloane, RJ Touramanis, C Back, JJ Cormack, CM Harrison, PF Di Lodovico, F Mohanty, GB Brown, CL Cowan, G Flack, RL Flaecher, HU Green, MG Jackson, PS McMahon, TR Ricciardi, S Salvatore, F Winter, MA Brown, D Davis, CL Allison, J Barlow, NR Barlow, RJ Hart, PA Hodgkinson, MC Lafferty, GD Lyon, AJ Williams, JC Farbin, A Hulsbergen, WD Jawahery, A Kovalskyi, D Lae, CK Lillard, V Roberts, DA Blaylock, G Dallapiccola, C Flood, KT Hertzbach, SS Kofler, R Koptchev, VB Moore, TB Saremi, S Staengle, H Willocq, S Cowan, R Sciolla, G Sekula, SJ Taylor, F Yamamoto, RK Mangeol, DJJ Patel, PM Robertson, SH Lazzaro, A Lombardo, V Palombo, F Bauer, JM Cremaldi, L Eschenburg, V Godang, R Kroeger, R Reidy, J Sanders, DA Summers, DJ Zhao, HW Brunet, S Cote, D Taras, P Nicholson, H Cavallo, N Fabozzi, F Gatto, C Lista, L Monorchio, D Paolucci, P Piccolo, D Sciacca, C Baak, M Bulten, H Raven, G Snoek, HL Wilden, L Jessop, CP LoSecco, JM Allmendinger, T Gan, KK Honscheid, K Hufnagel, D Kagan, H Kass, R Pulliam, T Rahimi, AM Ter-Antonyan, R Wong, QK Brau, J Frey, R Igonkina, O Potter, CT Sinev, NB Strom, D Torrence, E Colecchia, F Dorigo, A Galeazzi, F Margoni, M Morandin, M Posocco, M Rotondo, M Simonetto, F Stroili, R Tiozzo, G Voci, C Benayoun, M Briand, H Chauveau, J David, P de la Vaissiere, C Buono, LD Hamon, O John, MJJ Leruste, P Malcles, J Ocariz, J Pivk, M Roos, L T'Jampens, S Therin, G Manfredi, PF Re, V Behera, PK Gladney, L Guo, QH Panetta, J Angelini, C Batignani, G Bettarini, S Bondioli, M Bucci, F Calderini, G Carpinelli, M Forti, F Giorgi, MA Lusiani, A Marchiori, G Martinez-Vidal, F Morganti, M Neri, N Paoloni, E Rama, M Rizzo, G Sandrelli, F Walsh, J Haire, M Judd, D Paick, K Wagoner, DE Danielson, N Elmer, P Lau, YP Lu, C Miftakov, V Olsen, J Smith, AJS Telnov, AV Bellini, F Cavoto, G Faccini, R Ferrarotto, F Ferroni, F Gaspero, M Li Gioi, L Mazzoni, MA Morganti, S Pierini, M Piredda, G Tehrani, FS Voena, C Christ, S Wagner, G Waldi, R Adye, T De Groot, N Franek, B Geddes, NI Gopal, GP Olaiya, EO Aleksan, R Emery, S Gaidot, A Ganzhur, SF Giraud, PF de Monchenault, GH Kozanecki, W Legendre, M London, GW Mayer, B Schott, G Vasseur, G Yeche, C Zito, M Purohit, MV Weidemann, AW Wilson, JR Yumiceva, FX Aston, D Bartoldus, R Berger, N Boyarski, AM Buchmueller, OL Claus, R Convery, MR Cristinziani, M De Nardo, G Dong, D Dorfan, J Dujmic, D Dunwoodie, W Elsen, EE Fan, S Field, RC Glanzman, T Gowdy, SJ Hadig, T Halyo, V Hast, C Hryn'ova, T Innes, WR Kelsey, MH Kim, P Kocian, ML Leith, DWGS Libby, J Luitz, S Luth, V Lynch, HL Marsiske, H Messner, R Muller, DR O'Grady, CP Ozcan, VE Perazzo, A Perl, M Petrak, S Ratcliff, BN Roodman, A Salnikov, AA Schindler, RH Schwiening, J Simi, G Snyder, A Soha, A Stelzer, J Su, D Sullivan, MK Va'vra, J Wagner, SR Weaver, M Weinstein, AJR Wisniewski, WJ Wittgen, M Wright, DH Yarritu, AK Young, CC Burchat, PR Edwards, AJ Meyer, TI Petersen, BA Roat, C Ahmed, S Alam, MS Ernst, JA Saeed, MA Saleem, M Wappler, FR Bugg, W Krishnamurthy, M Spanier, SM Eckmann, R Kim, H Ritchie, JL Satpathy, A Schwitters, RF Izen, JM Kitayama, I Lou, XC Ye, S Bianchi, F Bona, M Gallo, F Gamba, D Bosisio, L Cartaro, C Cossutti, F Della Ricca, G Dittongo, S Grancagnolo, S Lanceri, L Poropat, P Vitale, L Vuagnin, G Panvini, RS Banerjee, S Brown, CM Fortin, D Jackson, PD Kowalewski, R Roney, JM Sobie, RJ Band, HR Cheng, B Dasu, S Datta, M Eichenbaum, AM Graham, M Hollar, JJ Johnson, JR Kutter, PE Li, H Liu, R Mihalyi, A Mohapatra, AK Pan, Y Prepost, R Tan, P von Wimmersperg-Toeller, JH Wu, J Wu, SL Yu, Z Greene, MG Neal, H CA BABAR Collaboration TI Search for radiative penguin decays B+->rho(+)gamma, B-0 ->rho(0)gamma, and B-0 ->omega gamma SO PHYSICAL REVIEW LETTERS LA English DT Article ID TO-LEADING ORDER; BRANCHING RATIOS; B-MESONS; PHYSICS; SUPERSYMMETRY; DETECTOR; GAMMA; QCD AB A search for the decays B-->rho(770)gamma and B-0-->omega(782)gamma is performed on a sample of 211x10(6) Y(4S)-->B (B) over bar events collected by the BABAR detector at the SLAC PEP-II asymmetric-energy e(+)e(-) storage ring. No evidence for the decays is seen. We set the following limits on the individual branching fractions: B(B+-->rho(+)gamma)<1.8x10(-6), B(B-0-->rho(0)gamma)<0.4x10(-6), and B(B-0-->omegagamma)<1.0x10(-6) at the 90% confidence level. We use the quark model to limit the combined branching fraction (B) over bar [B-->(rho/omega)gamma]<1.2x10(-6), from which we determine a constraint on the ratio of Cabibbo-Kobayashi-Maskawa matrix elements |V-td|/|V-ts|. C1 Lab Annecy Le Vieux Phys Particules, F-74941 Annecy Le Vieux, France. Univ Bari, Dipartmento Fis, I-70126 Bari, Italy. Ist Nazl Fis Nucl, I-70126 Bari, Italy. Inst High Energy Phys, Beijing 100039, Peoples R China. Univ Bergen, Inst Phys, N-5007 Bergen, Norway. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. Univ Birmingham, Birmingham B15 2TT, W Midlands, England. Ruhr Univ Bochum, Inst Expt Phys 1, D-44780 Bochum, Germany. Univ Bristol, Bristol BS8 1TL, Avon, England. Univ British Columbia, Vancouver, BC V6T 1Z1, Canada. Brunel Univ, Uxbridge UB8 3PH, Middx, England. Budker Inst Nucl Phys, Novosibirsk 630090, Russia. Univ Calif Irvine, Irvine, CA 92697 USA. Univ Calif Los Angeles, Los Angeles, CA 90024 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. Univ Calif Santa Cruz, Santa Cruz, CA 95064 USA. CALTECH, Pasadena, CA 91125 USA. Univ Cincinnati, Cincinnati, OH 45221 USA. Univ Colorado, Boulder, CO 80309 USA. Colorado State Univ, Ft Collins, CO 80523 USA. Tech Univ Dresden, Inst Kern & Teilchenphys, D-01062 Dresden, Germany. Ecole Polytech, LLR, F-91128 Palaiseau, France. Univ Edinburgh, Edinburgh EH9 3JZ, Midlothian, Scotland. Univ Ferrara, Dipartimento Fis, I-44100 Ferrara, Italy. Ist Nazl Fis Nucl, I-44100 Ferrara, Italy. Florida A&M Univ, Tallahassee, FL 32307 USA. Ist Nazl Fis Nucl, Lab Nazl Frascati, I-00044 Frascati, Italy. Univ Genoa, Dipartimento Fis, I-16146 Genoa, Italy. Ist Nazl Fis Nucl, I-16146 Genoa, Italy. Harvard Univ, Cambridge, MA 02138 USA. Heidelberg Univ, Inst Phys, D-69120 Heidelberg, Germany. Univ London Imperial Coll Sci Technol & Med, London SW7 2AZ, England. Univ Iowa, Iowa City, IA 52242 USA. Iowa State Univ, Ames, IA 50011 USA. Univ Perugia, Dipartimento Fis, I-06100 Perugia, Italy. Ist Nazl Fis Nucl, I-06100 Perugia, Italy. Lab Accelerateur Lineaire, F-91898 Orsay, France. Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. Univ Liverpool, Liverpool L69 72E, Merseyside, England. Univ London, Queen Mary, London E1 4NS, England. Univ London, Royal Holloway & Bedford New Coll, Egham TW20 0EX, Surrey, England. Univ Louisville, Louisville, KY 40292 USA. Univ Manchester, Manchester M13 9PL, Lancs, England. Univ Maryland, College Pk, MD 20742 USA. Univ Massachusetts, Amherst, MA 01003 USA. MIT, Nucl Sci Lab, Cambridge, MA 02139 USA. McGill Univ, Montreal, PQ H3A 2T8, Canada. Univ Milan, Dipartimento Fis, I-20133 Milan, Italy. Ist Nazl Fis Nucl, I-20133 Milan, Italy. Univ Mississippi, University, MS 38677 USA. Univ Montreal, Lab Rene JA Levesque, Montreal, PQ H3C 3J7, Canada. Mt Holyoke Coll, S Hadley, MA 01075 USA. Univ Naples Federico II, Dipartimento Sci Fis, I-80126 Naples, Italy. Ist Nazl Fis Nucl, I-80126 Naples, Italy. Natl Inst Nucl & High Energy Phys, NIKHEF, NL-1009 DB Amsterdam, Netherlands. Univ Notre Dame, Notre Dame, IN 46556 USA. Ohio State Univ, Columbus, OH 43210 USA. Univ Oregon, Eugene, OR 97403 USA. Univ Padua, Dipartimento Fis, I-35131 Padua, Italy. Ist Nazl Fis Nucl, I-35131 Padua, Italy. Univ Paris 06, Lab Phys Nucl & Hautes Energies, F-75252 Paris, France. Univ Paris 07, Lab Phys Nucl & Hautes Energies, F-75252 Paris, France. Univ Pavia, Dipartimento Elettron, I-27100 Pavia, Italy. Ist Nazl Fis Nucl, I-27100 Pavia, Italy. Univ Penn, Philadelphia, PA 19104 USA. Univ Pisa, Dipartimento Fis, I-56127 Pisa, Italy. Scuola Normale Super Pisa, I-56127 Pisa, Italy. Ist Nazl Fis Nucl, I-56127 Pisa, Italy. Prairie View A&M Univ, Prairie View, TX 77446 USA. Princeton Univ, Princeton, NJ 08544 USA. Univ Roma La Sapienza, Dipartimento Fis, I-00185 Rome, Italy. Ist Nazl Fis Nucl, I-00185 Rome, Italy. Univ Rostock, D-18051 Rostock, Germany. Rutherford Appleton Lab, Didcot OX11 0QX, Oxon, England. CEA Saclay, DSM Dapnia, F-91191 Gif Sur Yvette, France. Univ S Carolina, Columbia, SC 29208 USA. Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. Stanford Univ, Stanford, CA 94305 USA. SUNY Albany, Albany, NY 12222 USA. Univ Tennessee, Knoxville, TN 37996 USA. Univ Texas, Austin, TX 78712 USA. Univ Texas, Richardson, TX 75083 USA. Univ Turin, Dipartimento Fis Sperimentale, I-10125 Turin, Italy. Ist Nazl Fis Nucl, I-10125 Turin, Italy. Univ Trieste, Dipartimento Fis, I-34127 Trieste, Italy. Ist Nazl Fis Nucl, I-34127 Trieste, Italy. Vanderbilt Univ, Nashville, TN 37235 USA. Univ Victoria, Victoria, BC V8W 3P6, Canada. Univ Wisconsin, Madison, WI 53706 USA. Yale Univ, New Haven, CT 06511 USA. Univ Basilicata, I-85100 Potenza, Italy. Univ Valencia, CSIC, Inst Fis Corpuscular, IFIC, Valencia, Spain. RP Lab Annecy Le Vieux Phys Particules, F-74941 Annecy Le Vieux, France. RI Negrini, Matteo/C-8906-2014; de Groot, Nicolo/A-2675-2009; Lista, Luca/C-5719-2008; Bellini, Fabio/D-1055-2009; crosetti, nanni/H-3040-2011; Neri, Nicola/G-3991-2012; Forti, Francesco/H-3035-2011; Rotondo, Marcello/I-6043-2012; Patrignani, Claudia/C-5223-2009; de Sangro, Riccardo/J-2901-2012; Sarti, Alessio/I-2833-2012; Cavallo, Nicola/F-8913-2012; Saeed, Mohammad Alam/J-7455-2012; Monge, Maria Roberta/G-9127-2012; Luppi, Eleonora/A-4902-2015; Martinez Vidal, F*/L-7563-2014; Lo Vetere, Maurizio/J-5049-2012; Della Ricca, Giuseppe/B-6826-2013; Calcaterra, Alessandro/P-5260-2015; Frey, Raymond/E-2830-2016 OI Negrini, Matteo/0000-0003-0101-6963; Bellini, Fabio/0000-0002-2936-660X; Neri, Nicola/0000-0002-6106-3756; Forti, Francesco/0000-0001-6535-7965; Rotondo, Marcello/0000-0001-5704-6163; Patrignani, Claudia/0000-0002-5882-1747; de Sangro, Riccardo/0000-0002-3808-5455; Sarti, Alessio/0000-0001-5419-7951; Saeed, Mohammad Alam/0000-0002-3529-9255; Monge, Maria Roberta/0000-0003-1633-3195; Luppi, Eleonora/0000-0002-1072-5633; Martinez Vidal, F*/0000-0001-6841-6035; Lo Vetere, Maurizio/0000-0002-6520-4480; Della Ricca, Giuseppe/0000-0003-2831-6982; Calcaterra, Alessandro/0000-0003-2670-4826; Frey, Raymond/0000-0003-0341-2636 NR 25 TC 17 Z9 17 U1 1 U2 13 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 EI 1079-7114 J9 PHYS REV LETT JI Phys. Rev. Lett. PD JAN 14 PY 2005 VL 94 IS 1 AR 011801 DI 10.1103/PhysRevLett.94.011801 PG 7 WC Physics, Multidisciplinary SC Physics GA 887LQ UT WOS:000226308000016 PM 15698065 ER PT J AU Aubin, C Bernard, C DeTar, C DiPierro, M El-Khadra, A Gottlieb, S Gregory, EB Heller, UM Hetrick, J Kronfeld, AS Mackenzie, PB Menscher, D Nobes, M Okamoto, M Oktay, MB Osborn, J Simone, J Sugar, R Toussaint, D Trottier, HD AF Aubin, C Bernard, C DeTar, C DiPierro, M El-Khadra, A Gottlieb, S Gregory, EB Heller, UM Hetrick, J Kronfeld, AS Mackenzie, PB Menscher, D Nobes, M Okamoto, M Oktay, MB Osborn, J Simone, J Sugar, R Toussaint, D Trottier, HD CA Fermilab Lattice Collaboration MILC Collaboration HPQCD Collaboration TI Semileptonic decays of D mesons in three-flavor lattice QCD SO PHYSICAL REVIEW LETTERS LA English DT Article ID STAGGERED LIGHT QUARKS; FORM-FACTORS; HEAVY QUARKS AB We present the first three-flavor lattice QCD calculations for D-->pi\nu and D-->K\nu semileptonic decays. Simulations are carried out using ensembles of unquenched gauge fields generated by the MILC Collaboration. With an improved staggered action for light quarks, we are able to simulate at light quark masses down to 1/8 of the strange mass. Consequently, the systematic error from the chiral extrapolation is much smaller than in previous calculations with Wilson-type light quarks. Our results for the form factors at q(2)=0 are f(+)(D-->pi)(0)=0.64(3)(6) and f(+)(D-->K)(0)=0.73(3)(7), where the first error is statistical and the second is systematic, added in quadrature. Combining our results with experimental branching ratios, we obtain the Cabibbo-Kobayashi-Maskawa matrix elements |V-cd|=0.239(10)(24)(20) and |V-cs|=0.969(39)(94)(24), where the last errors are from experimental uncertainties. C1 Washington Univ, Dept Phys, St Louis, MO 63130 USA. Univ Utah, Dept Phys, Salt Lake City, UT 84112 USA. Depaul Univ, Sch Comp Sci Telecommun & Informat Syst, Chicago, IL 60604 USA. Univ Illinois, Dept Phys, Urbana, IL 61801 USA. Indiana Univ, Dept Phys, Bloomington, IN 47405 USA. Univ Arizona, Dept Phys, Tucson, AZ 85721 USA. Amer Phys Soc, Ridge, NY 11961 USA. Univ Pacific, Stockton, CA 95211 USA. Fermilab Natl Accelerator Lab, Batavia, IL 60510 USA. Simon Fraser Univ, Dept Phys, Vancouver, BC, Canada. Univ Calif Santa Barbara, Dept Phys, Santa Barbara, CA 93106 USA. RP Washington Univ, Dept Phys, St Louis, MO 63130 USA. OI Hetrick, James/0000-0002-0740-2251; Heller, Urs M./0000-0002-2780-5584 NR 24 TC 121 Z9 123 U1 0 U2 1 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 EI 1079-7114 J9 PHYS REV LETT JI Phys. Rev. Lett. PD JAN 14 PY 2005 VL 94 IS 1 AR 011601 DI 10.1103/PhysRevLett.94.011601 PG 5 WC Physics, Multidisciplinary SC Physics GA 887LQ UT WOS:000226308000013 PM 15698062 ER PT J AU Doorn, SK O'Connell, MJ Zheng, LX Zhu, YT Huang, SM Liu, J AF Doorn, SK O'Connell, MJ Zheng, LX Zhu, YT Huang, SM Liu, J TI Raman spectral imaging of a carbon nanotube intramolecular junction SO PHYSICAL REVIEW LETTERS LA English DT Article ID ELECTRONIC-PROPERTIES; SPECTROSCOPY; HETEROJUNCTIONS AB Confocal Raman spectral imaging results are presented for a metal-to-semiconductor intramolecular junction (IMJ) on an isolated carbon nanotube. Spectra observed at the junction are consistent with the symmetry lowering expected from the occurrence of pentagon-heptagon defects to produce the chirality shift. The IMJ transition zone is sharp and preserves the nanotube diameter. These results have significant implications for the future use of IMJs as electronic devices, including how prevalent these structures are and how their growth may be rationally targeted. Raman imaging has been demonstrated to be a powerful tool for IMJ studies and provides a more accessible method for further studies of IMJ structure and growth. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Duke Univ, Dept Chem, Durham, NC 27708 USA. RP Doorn, SK (reprint author), Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. EM skdoorn@lanl.gov RI Zhu, Yuntian/B-3021-2008; Zheng, Lianxi/A-3855-2011; Liu, Jie/B-4440-2010 OI Zhu, Yuntian/0000-0002-5961-7422; Zheng, Lianxi/0000-0003-4974-365X; Liu, Jie/0000-0003-0451-6111 NR 30 TC 52 Z9 52 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 JAN 14 PY 2005 VL 94 IS 1 AR 016802 DI 10.1103/PhysRevLett.94.016802 PG 4 WC Physics, Multidisciplinary SC Physics GA 887LQ UT WOS:000226308000063 PM 15698112 ER PT J AU Gerhardt, SP Talmadge, JN Canik, JM Anderson, DT AF Gerhardt, SP Talmadge, JN Canik, JM Anderson, DT TI Experimental evidence of reduced plasma flow damping with quasisymmetry SO PHYSICAL REVIEW LETTERS LA English DT Article ID BIASED ELECTRODE; DIII-D; STELLARATORS; ROTATION; PHYSICS; DESIGN AB Measurements of plasma flow damping have been made in the helically symmetric experiment using a biased electrode to impulsively spin the plasma. There are two time scales in the evolution of the plasma flow, for both the spin-up and relaxation. Compared to a configuration with the quasisymmetry broken, the flow in the quasisymmetric configuration rises more slowly and to a higher value at bias turn-on, and decays more slowly at bias turn-off. The decays of the flows are significantly faster than the neoclassical prediction. C1 Univ Wisconsin, Dept Elect & Comp Engn, Madison, WI 53706 USA. RP Gerhardt, SP (reprint author), Princeton Plasma Phys Lab, POB 451, Princeton, NJ 08543 USA. OI Canik, John/0000-0001-6934-6681 NR 18 TC 22 Z9 22 U1 1 U2 4 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD JAN 14 PY 2005 VL 94 IS 1 AR 015002 DI 10.1103/PhysRevLett.94.015002 PG 4 WC Physics, Multidisciplinary SC Physics GA 887LQ UT WOS:000226308000041 PM 15698090 ER PT J AU He, LX Bester, G Zunger, A AF He, LX Bester, G Zunger, A TI Prediction of an excitonic ground state in InAs/InSb quantum dots SO PHYSICAL REVIEW LETTERS LA English DT Article ID BOSE-EINSTEIN CONDENSATION; PSEUDOPOTENTIAL THEORY; TRANSITION; CRYSTALS; SYSTEM; STRAIN; GASES AB Using atomistic pseudopotential and configuration-interaction many-body calculations, we predict an excitonic ground state in the InAs/InSb quantum-dot system. For large dots, the conduction band minimum of the InAs dot lies below the valence band maximum of the InSb matrix. Due to quantum confinement, at a critical size calculated here for various shapes, the gap E-g between InAs conduction states and InSb valence states vanishes. Strong electron-hole correlation effects are induced by the spatial proximity of the electron and hole wave functions, and by the lack of strong (exciton unbinding) screening, afforded by the existence of discrete 0D confined energy levels. These correlation effects overcome E-g, leading to the formation of a biexcitonic ground state (two electrons in InAs and two holes in InSb) being energetically more favorable (by similar to15 meV) than the dot without excitons. C1 Natl Renewable Energy Lab, Golden, CO 80401 USA. RP He, LX (reprint author), Natl Renewable Energy Lab, Golden, CO 80401 USA. RI Bester, Gabriel/I-4414-2012; Zunger, Alex/A-6733-2013 OI Bester, Gabriel/0000-0003-2304-0817; NR 30 TC 21 Z9 21 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 JAN 14 PY 2005 VL 94 IS 1 AR 016801 DI 10.1103/PhysRevLett.94.016801 PG 4 WC Physics, Multidisciplinary SC Physics GA 887LQ UT WOS:000226308000062 PM 15698111 ER PT J AU Ocko, BM Kraack, H Pershan, PS Sloutskin, E Tamam, L Deutsch, M AF Ocko, BM Kraack, H Pershan, PS Sloutskin, E Tamam, L Deutsch, M TI Crystalline phases of alkyl-thiol monolayers on liquid mercury SO PHYSICAL REVIEW LETTERS LA English DT Article ID SELF-ASSEMBLED MONOLAYERS; LANGMUIR FILMS; THROUGH-BOND; X-RAY; SURFACE; JUNCTIONS; AU(111); METAL; DIFFRACTION; STABILITY AB The structure of octadecanethiol monolyers on liquid Hg surfaces, measured with subangstrom resolution, evolves with increasing coverage from a laterally disordered phase of surface-parallel molecules to ordered rotator phases of surface-normal molecules. For the latter, an abrupt transition is found at 19 A(2)/molecule from a rectangular packing of molecules tilted by 27degrees in the nearest-neighbor direction to a hexagonal unit cell of untilted molecules. The unit cell of the tilted phase is centered for the chains and noncentered for the headgroups. The thiol headgroups associate in pairs with a single Hg atom, and the bonds form long-range orientational order. The different order of thiols on Au(111) and on Hg highlights the subphase's role in determining the overlayer's structure. C1 Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. Bar Ilan Univ, Dept Phys, IL-52900 Ramat Gan, Israel. Harvard Univ, Dept Phys, Cambridge, MA 02138 USA. RP Ocko, BM (reprint author), Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. EM ocko@bnl.gov NR 31 TC 34 Z9 35 U1 0 U2 8 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD JAN 14 PY 2005 VL 94 IS 1 AR 017802 DI 10.1103/PhysRevLett.94.017802 PG 4 WC Physics, Multidisciplinary SC Physics GA 887LQ UT WOS:000226308000084 PM 15698133 ER PT J AU Park, T Nussinov, Z Hazzard, KRA Sidorov, VA Balatsky, AV Sarrao, JL Cheong, SW Hundley, MF Lee, JS Jia, QX Thompson, JD AF Park, T Nussinov, Z Hazzard, KRA Sidorov, VA Balatsky, AV Sarrao, JL Cheong, SW Hundley, MF Lee, JS Jia, QX Thompson, JD TI Novel dielectric anomaly in the hole-doped La2Cu1-xLixO4 and La2-xSrxNiO4 insulators: Signature of an electronic glassy state SO PHYSICAL REVIEW LETTERS LA English DT Article ID PHASE-DIAGRAM; SPIN-GLASS; ANTIFERROMAGNETIC ORDER; CHARGE STRIPES; SUPERCONDUCTORS; MAGNETISM; LA2CUO4 AB The low-frequency dielectric response of hole-doped insulators La2Cu1-xLixO4 and La2-xSrxNiO4 shows a large dielectric constant epsilon(') at high temperature and a steplike drop by a factor of 100 at a material-dependent low temperature T-f. T-f increases with frequency, and the dielectric response shows universal scaling in a Cole-Cole plot, suggesting that a charge-glass state is realized both in the cuprates and in the nickelates. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Ohio State Univ, Dept Phys, Columbus, OH 43210 USA. Rutgers State Univ, Dept Phys & Astron, Murray Hill, NJ 07974 USA. Lucent Technol, Bell Labs, Murray Hill, NJ 07974 USA. RP Park, T (reprint author), Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. RI Lee, Jang-Sik/A-6629-2008; Park, Tuson/A-1520-2012; Jia, Q. X./C-5194-2008 OI Lee, Jang-Sik/0000-0002-1096-1783; NR 31 TC 66 Z9 66 U1 0 U2 25 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD JAN 14 PY 2005 VL 94 IS 1 AR 017002 DI 10.1103/PhysRevLett.94.017002 PG 4 WC Physics, Multidisciplinary SC Physics GA 887LQ UT WOS:000226308000072 PM 15698121 ER PT J AU Pierce, MS Buechler, CR Sorensen, LB Turner, JJ Kevan, SD Jagla, EA Deutsch, JM Mai, T Narayan, O Davies, JE Liu, K Dunn, JH Chesnel, KM Kortright, JB Hellwig, O Fullerton, EE AF Pierce, MS Buechler, CR Sorensen, LB Turner, JJ Kevan, SD Jagla, EA Deutsch, JM Mai, T Narayan, O Davies, JE Liu, K Dunn, JH Chesnel, KM Kortright, JB Hellwig, O Fullerton, EE TI Disorder-induced microscopic magnetic memory SO PHYSICAL REVIEW LETTERS LA English DT Article AB Using coherent x-ray speckle metrology, we have measured the influence of disorder on major loop return point memory (RPM) and complementary point memory (CPM) for a series of perpendicular anisotropy Co/Pt multilayer films. In the low disorder limit, the domain structures show no memory with field cycling-no RPM and no CPM. With increasing disorder, we observe the onset and the saturation of both the RPM and the CPM. These results provide the first direct ensemble-sensitive experimental study of the effects of varying disorder on microscopic magnetic memory and are compared against the predictions of existing theories. C1 Univ Washington, Dept Phys, Seattle, WA 98195 USA. Univ Oregon, Dept Phys, Eugene, OR 97403 USA. Abdus Salam Int Ctr Theoret Phys, Trieste, Italy. Univ Calif Santa Cruz, Dept Phys, Santa Cruz, CA 95064 USA. Univ Calif Davis, Dept Phys, Davis, CA 95616 USA. MAX Lab, SE-22100 Lund, Sweden. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. Hitachi Global Storage Technol, San Jose, CA 95120 USA. RP Pierce, MS (reprint author), Univ Washington, Dept Phys, Seattle, WA 98195 USA. RI Davies, Joseph/C-4384-2008; Liu, Kai/B-1163-2008; Kevan, Stephen/F-6415-2010; Fullerton, Eric/H-8445-2013; Pierce, Michael/D-5570-2014 OI Davies, Joseph/0000-0001-5727-2371; Liu, Kai/0000-0001-9413-6782; Kevan, Stephen/0000-0002-4621-9142; Fullerton, Eric/0000-0002-4725-9509; Pierce, Michael/0000-0002-9209-8556 NR 17 TC 71 Z9 71 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 JAN 14 PY 2005 VL 94 IS 1 AR 017202 DI 10.1103/PhysRevLett.94.017202 PG 4 WC Physics, Multidisciplinary SC Physics GA 887LQ UT WOS:000226308000076 PM 15698125 ER PT J AU Rossi, P Mirazita, M Ronchetti, F De Sanctis, E Adams, G Ambrozewicz, P Anciant, E Anghinolfi, M Asavapibhop, B Audit, G Avakian, H Bagdasaryan, H Ball, JP Barrow, S Battaglieri, M Beard, K Bektasoglu, M Bellis, M Benmouna, N Berman, BL Bertozzi, W Bianchi, N Biselli, AS Boiarinov, S Bonner, BE Bouchigny, S Bradford, R Branford, D Briscoe, WJ Brooks, WK Burkert, VD Butuceanu, C Calarco, JR Carman, DS Carnahan, B Chen, S Cole, PL Cords, D Corvisiero, P Crabb, D Crannell, H Cummings, JP De Vita, R Degtyarenko, PV Denizli, H Dennis, L Deppman, A Dharmawardane, KV Dhuga, KS Djalali, C Dodge, GE Doughty, D Dragovitsch, P Dugger, M Dytman, S Dzyubak, OP Egiyan, H Egiyan, KS Elouadrhiri, L Empl, A Eugenio, P Fatemi, R Feuerbach, RJ Ficenec, J Forest, TA Funsten, H Gai, M Gavalian, G Gilad, S Gilfoyle, GP Giovanetti, KL Gordon, CIO Griffioen, K Guidal, M Guillo, M Guo, L Gyurjyan, V Hadjidakis, C Hakobyan, RS Hardie, J Heddle, D Hersman, FW Hicks, K Hicks, RS Holtrop, M Hu, J Hyde-Wright, CE Ilieva, Y Ito, MM Jenkins, D Jo, HS Joo, K Kellie, JD Khandaker, M Kim, KY Kim, K Kim, W Klein, A Klein, FJ Klimenko, AV Klusman, M Kossov, M Kramer, LH Kuhn, J Kuhn, SE Lachniet, J Laget, JM Lawrence, D Li, J Lima, ACS Livingston, K Lukashin, K Manak, JJ Marchand, C McAleer, S McCarthy, J McNabb, JWC Mecking, BA Mehrabyan, S Melone, JJ Mestayer, MD Meyer, CA Mikhailov, K Miskimen, R Mokeev, V Morand, L Morrow, SA Muccifora, V Mueller, J Mutchler, GS Napolitano, J Nasseripour, R Niccolai, S Niculescu, G Niculescu, I Niczyporuk, BB Niyazov, RA Nozar, M O'Brien, JT O'Rielly, GV Osipenko, M Ostrovidov, A Park, K Pasyuk, E Peterson, G Philips, SA Pivnyuk, N Pocanic, D Pogorelko, O Polli, E Pozdniakov, S Preedom, BM Price, JW Prok, Y Protopopescu, D Qin, LM Raue, BA Riccardi, G Ricco, G Ripani, M Ritchie, BG Rosner, G Rowntree, D Rubin, PD Sabatie, F Salgado, C Santoro, JP Sapunenko, V Schumacher, RA Serov, VS Sharabian, YG Shaw, J Simionatto, S Skabelin, AV Smith, ES Smith, LC Sober, DI Spraker, M Stavinsky, A Stepanyan, S Stokes, B Stoler, P Strakovsky, II Strauch, S Taiuti, M Taylor, S Tedeschi, DJ Thoma, U Thompson, R Tkabladze, A Todor, L Tur, C Ungaro, M Vineyard, MF Vlassov, AV Wang, K Weinstein, LB Weller, H Weygand, DP Whisnant, CS Wolin, E Wood, MH Yegneswaran, A Yun, J Zhang, B Zhou, Z AF Rossi, P Mirazita, M Ronchetti, F De Sanctis, E Adams, G Ambrozewicz, P Anciant, E Anghinolfi, M Asavapibhop, B Audit, G Avakian, H Bagdasaryan, H Ball, JP Barrow, S Battaglieri, M Beard, K Bektasoglu, M Bellis, M Benmouna, N Berman, BL Bertozzi, W Bianchi, N Biselli, AS Boiarinov, S Bonner, BE Bouchigny, S Bradford, R Branford, D Briscoe, WJ Brooks, WK Burkert, VD Butuceanu, C Calarco, JR Carman, DS Carnahan, B Chen, S Cole, PL Cords, D Corvisiero, P Crabb, D Crannell, H Cummings, JP De Vita, R Degtyarenko, PV Denizli, H Dennis, L Deppman, A Dharmawardane, KV Dhuga, KS Djalali, C Dodge, GE Doughty, D Dragovitsch, P Dugger, M Dytman, S Dzyubak, OP Egiyan, H Egiyan, KS Elouadrhiri, L Empl, A Eugenio, P Fatemi, R Feuerbach, RJ Ficenec, J Forest, TA Funsten, H Gai, M Gavalian, G Gilad, S Gilfoyle, GP Giovanetti, KL Gordon, CIO Griffioen, K Guidal, M Guillo, M Guo, L Gyurjyan, V Hadjidakis, C Hakobyan, RS Hardie, J Heddle, D Hersman, FW Hicks, K Hicks, RS Holtrop, M Hu, J Hyde-Wright, CE Ilieva, Y Ito, MM Jenkins, D Jo, HS Joo, K Kellie, JD Khandaker, M Kim, KY Kim, K Kim, W Klein, A Klein, FJ Klimenko, AV Klusman, M Kossov, M Kramer, LH Kuhn, J Kuhn, SE Lachniet, J Laget, JM Lawrence, D Li, J Lima, ACS Livingston, K Lukashin, K Manak, JJ Marchand, C McAleer, S McCarthy, J McNabb, JWC Mecking, BA Mehrabyan, S Melone, JJ Mestayer, MD Meyer, CA Mikhailov, K Miskimen, R Mokeev, V Morand, L Morrow, SA Muccifora, V Mueller, J Mutchler, GS Napolitano, J Nasseripour, R Niccolai, S Niculescu, G Niculescu, I Niczyporuk, BB Niyazov, RA Nozar, M O'Brien, JT O'Rielly, GV Osipenko, M Ostrovidov, A Park, K Pasyuk, E Peterson, G Philips, SA Pivnyuk, N Pocanic, D Pogorelko, O Polli, E Pozdniakov, S Preedom, BM Price, JW Prok, Y Protopopescu, D Qin, LM Raue, BA Riccardi, G Ricco, G Ripani, M Ritchie, BG Rosner, G Rowntree, D Rubin, PD Sabatie, F Salgado, C Santoro, JP Sapunenko, V Schumacher, RA Serov, VS Sharabian, YG Shaw, J Simionatto, S Skabelin, AV Smith, ES Smith, LC Sober, DI Spraker, M Stavinsky, A Stepanyan, S Stokes, B Stoler, P Strakovsky, II Strauch, S Taiuti, M Taylor, S Tedeschi, DJ Thoma, U Thompson, R Tkabladze, A Todor, L Tur, C Ungaro, M Vineyard, MF Vlassov, AV Wang, K Weinstein, LB Weller, H Weygand, DP Whisnant, CS Wolin, E Wood, MH Yegneswaran, A Yun, J Zhang, B Zhou, Z CA CLAS Collaboration TI Onset of asymptotic scaling in deuteron photodisintegration SO PHYSICAL REVIEW LETTERS LA English DT Article ID 2-BODY PHOTODISINTEGRATION AB We investigate the transition from the nucleon-meson to the quark-gluon description of the strong interaction using the photon energy dependence of the d(gamma,p)n differential cross section for photon energies above 0.5 GeV and center-of-mass proton angles between 30degrees and 150degrees. A possible signature for this transition is the onset of cross-section s(-11) scaling with the total energy squared, s, at some proton transverse momentum P-T. The results show that the scaling has been reached for proton transverse momentum above about 1.1 GeV/c. This may indicate that the quark-gluon regime is reached above this momentum. C1 Ist Nazl Fis Nucl, Lab Nazl Frascati, I-00044 Frascati, Italy. Univ Roma 3, I-00146 Rome, Italy. Arizona State Univ, Tempe, AZ 85287 USA. CEA Saclay, Serv Phys Nucl, F-91191 Gif Sur Yvette, France. Univ Calif Los Angeles, Los Angeles, CA 90095 USA. Carnegie Mellon Univ, Pittsburgh, PA 15213 USA. Catholic Univ Amer, Washington, DC 20064 USA. Christopher Newport Univ, Newport News, VA 23606 USA. Univ Connecticut, Storrs, CT 06269 USA. Duke Univ, Durham, NC 27708 USA. Univ Edinburgh, Edinburgh EH9 3JZ, Midlothian, Scotland. Florida Int Univ, Miami, FL 33199 USA. Florida State Univ, Tallahassee, FL 32306 USA. George Washington Univ, Washington, DC 20052 USA. Univ Glasgow, Glasgow G12 8QQ, Lanark, Scotland. Ist Nazl Fis Nucl, Sez Genova, I-16146 Genoa, Italy. Inst Phys Nucl, IN2P3, F-91406 Orsay, France. Inst Theoret & Expt Phys, Moscow 117259, Russia. James Madison Univ, Harrisonburg, VA 22807 USA. Kyungpook Natl Univ, Taegu 702701, South Korea. MIT, Cambridge, MA 02139 USA. Univ Massachusetts, Amherst, MA 01003 USA. Moscow MV Lomonosov State Univ, Moscow 119899, Russia. Univ New Hampshire, Durham, NH 03824 USA. Norfolk State Univ, Norfolk, VA 23504 USA. Ohio Univ, Athens, OH 45701 USA. Old Dominion Univ, Norfolk, VA 23529 USA. Univ Pittsburgh, Pittsburgh, PA 15260 USA. Rensselaer Polytech Inst, Troy, NY 12180 USA. Rice Univ, Houston, TX 77005 USA. Univ Richmond, Richmond, VA 23173 USA. Univ S Carolina, Columbia, SC 29208 USA. Univ Texas, El Paso, TX 79968 USA. Thomas Jefferson Natl Accelerator Facil, Newport News, VA 23606 USA. Union Coll, Schenectady, NY 12308 USA. Virginia Polytech Inst & State Univ, Blacksburg, VA 24061 USA. Univ Virginia, Charlottesville, VA 22901 USA. Coll William & Mary, Williamsburg, VA 23187 USA. Yerevan Phys Inst, Yerevan 375036, Armenia. RP Rossi, P (reprint author), Ist Nazl Fis Nucl, Lab Nazl Frascati, POB 13, I-00044 Frascati, Italy. RI Deppman, Airton/F-6332-2010; Bektasoglu, Mehmet/A-2074-2012; Protopopescu, Dan/D-5645-2012; riccardi, gabriele/A-9269-2012; Brooks, William/C-8636-2013; Schumacher, Reinhard/K-6455-2013; Meyer, Curtis/L-3488-2014; Sabatie, Franck/K-9066-2015; Deppman, Airton/J-5787-2014; OI Deppman, Airton/0000-0001-9179-6363; Brooks, William/0000-0001-6161-3570; Schumacher, Reinhard/0000-0002-3860-1827; Meyer, Curtis/0000-0001-7599-3973; Sabatie, Franck/0000-0001-7031-3975; Deppman, Airton/0000-0001-9179-6363; Hyde, Charles/0000-0001-7282-8120; Bellis, Matthew/0000-0002-6353-6043 NR 15 TC 33 Z9 33 U1 0 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 JAN 14 PY 2005 VL 94 IS 1 AR 012301 DI 10.1103/PhysRevLett.94.012301 PG 5 WC Physics, Multidisciplinary SC Physics GA 887LQ UT WOS:000226308000024 PM 15698073 ER PT J AU Schroder, C Nojiri, H Schnack, J Hage, P Luban, M Kogerler, P AF Schroder, C Nojiri, H Schnack, J Hage, P Luban, M Kogerler, P TI Competing spin phases in geometrically frustrated magnetic molecules SO PHYSICAL REVIEW LETTERS LA English DT Article ID ANTIFERROMAGNET; FIELD; LATTICE; SPHERES; STATE AB We identify a class of zero-dimensional classical and quantum Heisenberg spin systems exhibiting anomalous behavior in an external magnetic field B similar to that found for the geometrically frustrated kagome lattice of classical spins. Our calculations for the isotropic Heisenberg model show the emergence of a pronounced minimum in the differential susceptibility dM/dB at B-sat/3 as the temperature T is raised from 0 K for structures based on corner-sharing triangles, specifically the octahedron, cuboctahedron, and icosidodecahedron. As the first experimental evidence we note that the giant Keplerate magnetic molecule {Mo72Fe30} (Fe3+ ions on the 30 vertices of an icosidodecahedron) exhibits this behavior. For low T when Bapproximate toB(sat)/3 two competing families of spin configurations exist of which one behaves magnetically "stiff" leading to a reduction of dM/dB. C1 Univ Appl Sci Bielefeld, Dept Elect Engn & Comp Sci, D-33602 Bielefeld, Germany. Iowa State Univ, Ames Lab, Ames, IA 50011 USA. Okayama Univ, Dept Phys, Okayama 7008530, Japan. Univ Osnabruck, Fachbereich Phys, D-49069 Osnabruck, Germany. Iowa State Univ, Dept Phys & Astron, Ames, IA 50011 USA. RP Schroder, C (reprint author), Univ Appl Sci Bielefeld, Dept Elect Engn & Comp Sci, D-33602 Bielefeld, Germany. EM schroder@ameslab.gov RI Schnack, Jurgen/A-4079-2008; Nojiri, Hiroyuki/B-3688-2011; Kogerler, Paul/H-5866-2013 OI Schnack, Jurgen/0000-0003-0702-2723; Kogerler, Paul/0000-0001-7831-3953 NR 16 TC 65 Z9 65 U1 0 U2 12 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD JAN 14 PY 2005 VL 94 IS 1 AR 017205 DI 10.1103/PhysRevLett.94.017205 PG 4 WC Physics, Multidisciplinary SC Physics GA 887LQ UT WOS:000226308000079 PM 15698128 ER PT J AU Strachan, A Holian, BL AF Strachan, A Holian, BL TI Energy exchange between mesoparticles and their internal degrees of freedom SO PHYSICAL REVIEW LETTERS LA English DT Article ID MOLECULAR-DYNAMICS; SIMULATION; COLLISIONS AB We present mesoscale equations of motion that lead to a thermodynamically accurate description of the energy exchange between mesoparticles and their internal degrees of freedom. In our approach, energy exchange is done through particle coordinates, rather than momenta, resulting in Galilean invariant equations of motion. The total linear momentum and total energy (including the internal energy of the mesoparticles) are conserved, and no coupling occurs when a mesoparticle is in free flight. We test our method for shock wave propagation in a crystalline polymer, poly(vinylidene fluoride); the mesodynamics results agree very well with all-atom molecular dynamics. C1 Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. RP Strachan, A (reprint author), Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. NR 17 TC 35 Z9 35 U1 0 U2 8 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD JAN 14 PY 2005 VL 94 IS 1 AR 014301 DI 10.1103/PhysRevLett.94.014301 PG 4 WC Physics, Multidisciplinary SC Physics GA 887LQ UT WOS:000226308000036 PM 15698085 ER PT J AU Bradley, J Dai, ZR Erni, R Browning, N Graham, G Weber, P Smith, J Hutcheon, I Ishii, H Bajt, S Floss, C Stadermann, F Sandfords, S AF Bradley, J Dai, ZR Erni, R Browning, N Graham, G Weber, P Smith, J Hutcheon, I Ishii, H Bajt, S Floss, C Stadermann, F Sandfords, S TI An astronomical 2175 angstrom feature in interplanetary dust particles SO SCIENCE LA English DT Article ID ULTRAVIOLET EXTINCTION CURVES; SOLAR-SYSTEM; GRAINS; IDENTIFICATION; CONSTRAINTS; SHAPES; CARBON AB The 2175 angstrom extinction feature is the strongest (visible-ultraviolet) spectral signature of dust in the interstellar medium. Forty years after its discovery, the origin of the feature and the nature of the carrier(s) remain controversial. Using a transmission electron microscope, we detected a 5.7-electron volt (2175 angstrom) feature in interstellar grains embedded within interplanetary dust particles (IDPs). The carriers are organic carbon and amorphous silicates that are abundant in IDPs and in the interstellar medium. These multiple carriers may explain the enigmatic invariant central wavelength and variable bandwidth of the astronomical 2175 angstrom feature. C1 Lawrence Livermore Natl Lab, Inst Geophys & Planetary Phys, Livermore, CA 94550 USA. Univ Calif Davis, Dept Chem Engn, Davis, CA 95616 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Natl Ctr Electron Microscopy, Berkeley, CA 94720 USA. Washington Univ, Space Sci Lab, St Louis, MO 63130 USA. NASA, Ames Res Ctr, Astrophys Branch, Moffett Field, CA 94035 USA. RP Bradley, J (reprint author), Lawrence Livermore Natl Lab, Inst Geophys & Planetary Phys, Livermore, CA 94550 USA. EM jbradley@igpp.ucllnl.org RI Dai, Zurong/E-6732-2010; Bajt, Sasa/G-2228-2010; Erni, Rolf/P-7435-2014 OI Erni, Rolf/0000-0003-2391-5943 NR 26 TC 46 Z9 46 U1 1 U2 11 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 JAN 14 PY 2005 VL 307 IS 5707 BP 244 EP 247 DI 10.1126/science.1106717 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 888GJ UT WOS:000226361900039 PM 15653501 ER PT J AU Chervin, C Glass, RS Kauzlarich, SM AF Chervin, C Glass, RS Kauzlarich, SM TI Chemical degradation of La1-xSrMnO3/Y2O3-stabilized ZrO2 composite cathodes in the presence of current collector pastes SO SOLID STATE IONICS LA English DT Article DE current collector; fuel cell; La1-xSrMnO3; Bi subnitrate; bismuth oxide; La2Zr2O7; lanthanum zirconate; SOFC; LSM; YSZ; cathode; ZrO2 ID OXIDE FUEL-CELLS; YTTRIA-STABILIZED ZIRCONIA; INTERMEDIATE TEMPERATURE SOFC; IMPEDANCE SPECTROSCOPY; ELECTROCHEMICAL PROPERTIES; LANTHANUM MANGANITE; OXYGEN REDUCTION; ELECTROLYTE; INTERFACE; LAMNO3 AB The chemical reactivity of current collector pastes, utilized in electrode performance measurements, were investigated with respect to the solid oxide fuel cell composite cathode, (La85Sr15)(98)MnO3/8 mol% Y2O3-stabilized ZrO2 (LSM/YSZ). Anode substrate single cells were prepared with Pt or Ag paste current collectors applied to the electrodes. Phase purity of the cathodes before and after sintering the current collectors were examined with powder X-ray diffraction (XRD) and the performance of the cells determined with current-potential measurements. XRD experiments provided evidence that Pt paste, containing a bismuth flux, reacted with the composite cathode at temperatures above 800 degreesC leading to formation of the pyrochlore phase, La2Zr2O7. Cathodes coated with Ag paste, which did not contain a bismuth flux, showed no sign of chemical degradation. Synthesized Bi-subnitrate and commercial Bi2O3 were shown to have similar chemical reactions with LSM/YSZ powders leading to pyrochlore phase formation. Current-potential experiments on single test cells demonstrated that samples prepared with paste containing bismuth flux had a decrease in initial performance. (C) 2004 Elsevier B.V. All rights reserved. C1 Univ Calif Davis, Dept Chem, Davis, CA 95616 USA. Lawrence Livermore Natl Lab, Univ Outreach, Livermore, CA 94550 USA. Lawrence Livermore Natl Lab, Energy & Environm Directorate, Livermore, CA 94550 USA. RP Kauzlarich, SM (reprint author), Univ Calif Davis, Dept Chem, 1 Shields Ave, Davis, CA 95616 USA. EM smkauzlarich@ucdavis.edu RI Kauzlarich, Susan/H-1439-2011 NR 39 TC 33 Z9 36 U1 1 U2 19 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0167-2738 J9 SOLID STATE IONICS JI Solid State Ion. PD JAN 14 PY 2005 VL 176 IS 1-2 BP 17 EP 23 DI 10.1016/j.ssi.2004.06.004 PG 7 WC Chemistry, Physical; Physics, Condensed Matter SC Chemistry; Physics GA 883NW UT WOS:000226020900003 ER PT J AU Tarumi, T Small, GW Combs, RJ Kroutil, RT AF Tarumi, T Small, GW Combs, RJ Kroutil, RT TI Infinite impulse response filters for direct analysis of interferogram data from airborne passive Fourier transform infrared spectrometry SO VIBRATIONAL SPECTROSCOPY LA English DT Article DE digital filtering; infinite impulse response filters; Fourier transform infrared spectrometry; interferograin processing; remote sensing ID TIME DIGITAL-FILTERS; SUPPORT VECTOR MACHINES; FLOW-INJECTION ANALYSIS; AUTOMATED DETECTION; PATTERN-RECOGNITION; DESIGN; PLUMES; RECONSTRUCTION; CHROMATOGRAMS; SPECTROSCOPY AB Infinite impulse response (IIR) filters and support vector machines (SVMs) are applied to interferogram data to implement the automated detection of heated ethanol plumes by airborne passive Fourier transform infrared (FT-IR) spectrometry. To simulate monitoring of industrial emissions, the spectrometer is mounted in a downward-looking mode on a fixed-wing aircraft and used to detect plumes released from a portable emission stack. Both IIR and finite impulse response (FIR) filters having similar frequency responses are designed and applied to the interferogram data to extract the information associated with the ethanol C-O stretching band at 1066 cm(-1). This study investigates the effects of distortions in the interferogram introduced by the nonlinear phase responses of the IIR filters on the ability of the SVMs to recognize ethanol. In addition, three ways to apply the filters to the interferogram are explored. These studies reveal that the phase distortion introduced by the IIR filters causes no measurable degradation in classifier performance. This allows the intrinsically lower filter order of the IIR filters to be used to reduce the length of the interferogram segment required to implement the filtering. With an independent prediction set of interferograms collected during overflights of the stack, the best SVMs miss detecting ethanol in less than 4% of the cases while achieving false detection (false positive) rates of less than 0.5%. This level of performance is accomplished with an interferogram segment of only 24 points, including those points required to implement the filtering. The ability to detect analyte vapor plumes with such a short interferogram segment is particularly advantageous in the airborne measurement because of the potential to increase the interferogram acquisition rate, thereby improving the ability to resolve ground-based targets. (C) 2004 Elsevier B.V. All rights reserved. C1 Ohio Univ, Clippinger Labs, Dept Chem & Biochem, Ctr Intelligent Chem Instrumentat, Athens, OH 45701 USA. Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Small, GW (reprint author), Ohio Univ, Clippinger Labs, Dept Chem & Biochem, Ctr Intelligent Chem Instrumentat, Athens, OH 45701 USA. EM small@ohio.edu NR 32 TC 5 Z9 6 U1 0 U2 7 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0924-2031 J9 VIB SPECTROSC JI Vib. Spectrosc. PD JAN 14 PY 2005 VL 37 IS 1 BP 39 EP 52 DI 10.1016/j.vibspec.2004.06.002 PG 14 WC Chemistry, Analytical; Chemistry, Physical; Spectroscopy SC Chemistry; Spectroscopy GA 892ZP UT WOS:000226688800006 ER PT J AU Mutschlecner, JP Whitaker, RW AF Mutschlecner, JP Whitaker, RW TI Infrasound from earthquakes SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID WAVES AB [ 1] Infrasonic signals have been observed from 31 earthquakes by arrays of microphones operated by the Los Alamos National Laboratory between 1983 and 2003. The properties of the signals are presented. Signal amplitudes corrected for propagation and distance show a relation with seismic magnitude. The variance in the relation is understood primarily in terms of the uncertainties or errors in the ground motion, deduced from an independent data set, and the stratospheric winds, which strongly influence signal propagation. Signal durations can extend over many minutes. A relation is found between signal duration and magnitude. To understand this, we propose a model in which regions distant from the epicenter are excited by seismic surface waves. The surface motion of these regions, in turn, produces signals which precede or follow the signals from the epicenter. Analysis failed to detect signals from 56 earthquakes during the observation period. Predicted signal-to-noise ratios for these earthquakes indicated that the signals would have been too weak for detection. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Mutschlecner, JP (reprint author), Los Alamos Natl Lab, EES-5,MS F665, Los Alamos, NM 87545 USA. EM rww@lanl.gov NR 24 TC 52 Z9 56 U1 4 U2 17 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD JAN 13 PY 2005 VL 110 IS D1 AR D01108 DI 10.1029/2004JD005067 PG 11 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 890YP UT WOS:000226548000001 ER PT J AU Hosoya, N Takegami, R Suzumura, J Yada, K Koyasu, K Miyajima, K Mitsui, M Knickelbein, MB Yabushita, S Nakajima, A AF Hosoya, N Takegami, R Suzumura, J Yada, K Koyasu, K Miyajima, K Mitsui, M Knickelbein, MB Yabushita, S Nakajima, A TI Lanthanide organometallic sandwich nanowires: Formation mechanism SO JOURNAL OF PHYSICAL CHEMISTRY A LA English DT Letter ID GAS-PHASE; COMPLEXES; CLUSTERS AB A molecular beam of europium-cyclooctatetraene sandwich nanowires Eu-n(COT)(m) was produced by a laser vaporization synthesis method. The formation mechanism of the nanowires was quantitatively revealed by photoelectron and photoionization spectroscopies of the Eu-COT species, together with supporting theoretical calculations. From these results. it is confirmed that growth processes extending the length of Eu-COT nanowires involve a series of elementary reactions in which efficient charge transfer occur at the terminal reaction sites. In every elementary step, the reaction proceeds between one reactant having low ionization energy and the other reactant having high electron affinity, probably via a "harpoon" mechanism. C1 Keio Univ, Fac Sci & Technol, Dept Chem, Kohoku Ku, Yokohama, Kanagawa 2238522, Japan. Argonne Natl Lab, Div Chem, Argonne, IL 60439 USA. RP Nakajima, A (reprint author), Keio Univ, Fac Sci & Technol, Dept Chem, Kohoku Ku, 3-14-1 Hiyoshi, Yokohama, Kanagawa 2238522, Japan. EM nakajima@chem.keio.ac.jp RI Miyajima, Ken/C-8422-2013; Yabushita, Satoshi/C-5784-2014 OI Miyajima, Ken/0000-0002-5385-8911; NR 10 TC 45 Z9 45 U1 2 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 JAN 13 PY 2005 VL 109 IS 1 BP 9 EP 12 DI 10.1021/jp0452103 PG 4 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 886FT UT WOS:000226213000003 PM 16839084 ER PT J AU Creighton, JR Wang, GT AF Creighton, JR Wang, GT TI Reversible adduct formation of trimethylgallium and trimethylindium with ammonia SO JOURNAL OF PHYSICAL CHEMISTRY A LA English DT Article ID CHEMICAL-VAPOR-DEPOSITION; GAS-PHASE REACTIONS; GALLIUM NITRIDE; GROWTH; ALGAN; EPITAXY; CHEMISTRY; MOVPE; PRECURSORS; MOCVD AB We have used gas-phase infrared spectroscopy to determine the equilibrium constant (K-p) for the formation of (CH3)(3)Ga:NH3 and (CH3)(3)In:NH3 adducts in the 80-230 degreesC range. In this temperature range, and at reactant concentrations typically used for metal organic chemical vapor deposition. the dominant chemical reaction is reversible adduct formation/dissociation. Reaction enthalpies and entropies are extracted from the temperature dependence of K-p, yielding DeltaH(Ga) = -16.3 +/- 0.5 kcal/mol, DeltaS(Ga) = -32.4 +/- 1.2 eu, and DeltaH(In) = -15.0 +/- 0.6 kcal/mol, DeltaS(In) = -30.3 +/- 1.4 eu. These results will aid current and future modeling efforts, as well as advance our general understanding, of the 2,group-III nitride deposition process. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Creighton, JR (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. EM jrcreig@sandia.gov RI Wang, George/C-9401-2009 OI Wang, George/0000-0001-9007-0173 NR 26 TC 20 Z9 23 U1 0 U2 7 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 JAN 13 PY 2005 VL 109 IS 1 BP 133 EP 137 DI 10.1021/jp046491h PG 5 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 886FT UT WOS:000226213000016 PM 16839097 ER PT J AU Goldberger, J Sirbuly, DJ Law, M Yang, P AF Goldberger, J Sirbuly, DJ Law, M Yang, P TI ZnO nanowire transistors SO JOURNAL OF PHYSICAL CHEMISTRY B LA English DT Letter ID FIELD-EFFECT TRANSISTORS; THIN-FILM TRANSISTORS; ZINC-OXIDE; ELECTRICAL-PROPERTIES; N-ZNO; CONTACT RESISTANCE; ROOM-TEMPERATURE; OHMIC CONTACTS; SURFACE; NANOSENSORS AB ZnO nanowire field-effect transistors (FETs) were fabricated and studied in vacuum and a variety of ambient gases from 5 to 300 K. In air, these n-type nanowire transistors have among the highest mobilities yet reported for ZnO FETs (mu(e) = 13 +/- 5 cm(2) V-1 s(-1)), with carrier concentrations averaging 5.2 +/- 2.5 x 10(17) cm(-3) and on-off current ratios ranging from 10(5) to 10(7). Four probe measurements show that the resistivity of the Ti/Au-ZnO contacts is 0.002-0.02 Omega-cm. The performance characteristics of the nanowire transistors are intimately tied to the presence and nature of adsorbed surface species. In addition, we describe a dynamic gate effect that seems to involve mobile surface charges and causes hysteresis in the transconductance, among other effects. C1 Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Dept Chem, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Div Mat Sci, Berkeley, CA 94720 USA. RP Yang, P (reprint author), Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Dept Chem, Berkeley, CA 94720 USA. EM p_yang@uclink.berkeley.edu RI Goldberger, Joshua/F-5484-2011; Goldberger, Joshua/N-8963-2016 OI Goldberger, Joshua/0000-0003-4284-604X; Goldberger, Joshua/0000-0003-4284-604X NR 43 TC 441 Z9 448 U1 8 U2 115 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 JAN 13 PY 2005 VL 109 IS 1 BP 9 EP 14 DI 10.1021/jp0452599 PG 6 WC Chemistry, Physical SC Chemistry GA 886FV UT WOS:000226213200003 PM 16850973 ER PT J AU Lai, JI Shafi, KVPM Ulman, A Loos, K Lee, YJ Vogt, T Lee, WL Ong, NP AF Lai, JI Shafi, KVPM Ulman, A Loos, K Lee, YJ Vogt, T Lee, WL Ong, NP TI Controlling the size of magnetic nanoparticles using pluronic block copolymer surfactants SO JOURNAL OF PHYSICAL CHEMISTRY B LA English DT Letter ID NANOCRYSTAL SUPERLATTICES AB We have successfully controlled the size of magnetic nanoparticles by adjusting the surfactant/solvent ratio. gamma-Fe2O3 nanoparticles of 5.6 and 12.7, and Fe-0 nanoparticles of 22.3 nm in diameter were prepared, all having spherical shape and uniform size as confirmed by TEM. Mossbauer spectra confirmed Fe 31 for the 5.6 and 12.7 run particles and Fe3+ and Fe-0 for 22.3 nm particles, in good agreement with synchrotron XRD patterns. Both room temperature and 5 K H-M measurements show that 22.3 nm particles have much higher magnetization than their oxide Counterparts, in agreement with their being Fe-0. T-M measurements show superparamagnetism for 5.6 and 12.7 nm particles and ferromagnetism for 22.3 nm particles. C1 Polytech Univ, Dept Biol & Chem Sci & Engn, Brooklyn, NY 11201 USA. Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. Princeton Univ, Dept Phys, Princeton, NJ 08544 USA. RP Ulman, A (reprint author), Polytech Univ, Dept Biol & Chem Sci & Engn, 6 Metrotech Ctr, Brooklyn, NY 11201 USA. EM aulman@duke.poly.edu RI Loos, Katja/B-9792-2008; Vogt, Thomas /A-1562-2011; Lee, Yongjae/K-6566-2016; ESTOURNES, Claude/F-2322-2017 OI Loos, Katja/0000-0002-4613-1159; Vogt, Thomas /0000-0002-4731-2787; ESTOURNES, Claude/0000-0001-8381-8454 NR 12 TC 43 Z9 43 U1 0 U2 4 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 1520-6106 J9 J PHYS CHEM B JI J. Phys. Chem. B PD JAN 13 PY 2005 VL 109 IS 1 BP 15 EP 18 DI 10.1021/jp0457702 PG 4 WC Chemistry, Physical SC Chemistry GA 886FV UT WOS:000226213200004 PM 16850974 ER PT J AU Wang, JX Robinson, IK Ocko, BM Adzic, RR AF Wang, JX Robinson, IK Ocko, BM Adzic, RR TI Adsorbate-geometry specific subsurface relaxation in the CO/Pt(111) system SO JOURNAL OF PHYSICAL CHEMISTRY B LA English DT Letter ID CARBON-MONOXIDE; SURFACE; CO; CHEMISORPTION; PT(111) AB A dramatic multilayer substrate relaxation is observed for the (root19 x root19)-13CO adlayer phase on a Pt(111) electrode by surface X-ray scattering. Within the (root19 x root19) unit cell, a vertical expansion of 0.28 Angstrom was determined for the Pt atoms under near-to-site CO molecules, whereas only 0.04 Angstrom was found under near-bridge-site CO molecules. The lateral displacements involve small rotations toward more symmetric bonding. Both the expansions and rotations extend into the bulk with a decay length of 1.8 Pt layers. This nonuniform layer expansion, hitherto unseen, appears to be a manifestation of the differential stress induced by CO adsorption at different sites. C1 Brookhaven Natl Lab, Dept Mat Sci, Upton, NY 11973 USA. Univ Illinois, Dept Phys, Urbana, IL 61801 USA. Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. RP Wang, JX (reprint author), Brookhaven Natl Lab, Dept Mat Sci, Upton, NY 11973 USA. RI Wang, Jia/B-6346-2011 NR 14 TC 30 Z9 30 U1 0 U2 9 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 JAN 13 PY 2005 VL 109 IS 1 BP 24 EP 26 DI 10.1021/jp045082i PG 3 WC Chemistry, Physical SC Chemistry GA 886FV UT WOS:000226213200006 PM 16850976 ER PT J AU Szanyi, J Kwak, JH Kim, DH Burton, SD Peden, CHF AF Szanyi, J Kwak, JH Kim, DH Burton, SD Peden, CHF TI NO2 adsorption on BaO/Al2O3: The nature of nitrate species SO JOURNAL OF PHYSICAL CHEMISTRY B LA English DT Letter ID BARIUM OXIDE; FT-IR; STORAGE; CATALYSTS AB Temperature programmed desorption, infrared spectroscopy, and N-15 solid state NMR spectroscopy were used to characterize the nature of the nitrate species formed on Al2O3 and BaO/Al2O3 NOx storage/reduction materials. Two distinctly different nitrate species were found: surface nitrates that are associated with a monolayer BaO on the alumina support, and a bulk-like nitrate that forms on this thin BaO layer. The surface nitrates desorb as NO2 at lower temperatures than do the bulk-like nitrates, which decompose as NO+O-2 at higher temperatures. The amount of NOx stored in the monolayer nitrate is proportional to the surface area of the catalyst, while that in the bulk nitrate increases with BaO coverage. C1 Pacific NW Natl Lab, Richland, WA 99352 USA. RP Szanyi, J (reprint author), Pacific NW Natl Lab, POB 999,MSIN K8-93, Richland, WA 99352 USA. EM janos.szany@pnl.gov RI Kwak, Ja Hun/J-4894-2014; Kim, Do Heui/I-3727-2015; OI Peden, Charles/0000-0001-6754-9928 NR 10 TC 101 Z9 101 U1 5 U2 20 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 JAN 13 PY 2005 VL 109 IS 1 BP 27 EP 29 DI 10.1021/jp044993p PG 3 WC Chemistry, Physical SC Chemistry GA 886FV UT WOS:000226213200007 PM 16850977 ER PT J AU Horn, JM Song, Z Potapenko, DV Hrbek, J White, MG AF Horn, JM Song, Z Potapenko, DV Hrbek, J White, MG TI Characterization of molybdenum carbide nanoparticles formed on Au(111) using reactive-layer assisted deposition SO JOURNAL OF PHYSICAL CHEMISTRY B LA English DT Letter ID TRANSITION-METAL CARBIDES; MODIFIED MO(110); CATALYTIC-PROPERTIES; SURFACE REACTIVITY; TUNGSTEN CARBIDE; SYNTHESIS GAS; GROWTH; PHOTOEMISSION; ADSORPTION; THIOPHENE AB Temperature programmed desorption (TPD), Auger electron spectroscopy (AES), X-ray photoelectron spectroscopy (XPS), and scanning tunneling microscopy (STM) have been used to characterize molybdenum carbide nanoparticles prepared on a Au(111) substrate. The MoCx nanoparticles were formed by Mo metal deposition onto a reactive multilayer of ethylene, which was physisorbed on a Au(111) substrate at low temperatures (<100 K). The resulting clusters have an average diameter of similar to1.5 nm and aggregate in the fee troughs located on either side of the elbows of the reconstructed Au(111) surface. Core level XPS shows that the electronic environment of the Mo and C atoms in the nanoparticles is similar to that found in Mo2C-(0001) single crystals and carburized Mo metal surfaces. Peak intensities in XPS and AES spectra were used to estimate an average Mo/C atomic ratio of 1.2 +/- 0.3 for nanoparticles annealed above 600 K. C1 Brookhaven Natl Lab, Dept Chem, Upton, NY 11973 USA. SUNY Stony Brook, Dept Chem, Stony Brook, NY 11794 USA. RP White, MG (reprint author), Brookhaven Natl Lab, Dept Chem, Upton, NY 11973 USA. EM mgwhite@bnl.gov RI Hrbek, Jan/I-1020-2013 NR 40 TC 21 Z9 21 U1 2 U2 35 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 JAN 13 PY 2005 VL 109 IS 1 BP 44 EP 47 DI 10.1021/jp044837i PG 4 WC Chemistry, Physical SC Chemistry GA 886FV UT WOS:000226213200012 PM 16850982 ER PT J AU Song, H Kim, F Connor, S Somorjai, GA Yang, PD AF Song, H Kim, F Connor, S Somorjai, GA Yang, PD TI Pt nanocrystals: Shape control and Langmuir-Blodgett monolayer formation SO JOURNAL OF PHYSICAL CHEMISTRY B LA English DT Article ID COLLOIDAL PLATINUM NANOPARTICLES; SILVER NANOPARTICLES; GOLD NANOPARTICLES; OPTICAL-PROPERTIES; AQUEOUS-SOLUTION; SIZE; MORPHOLOGY; NANOWIRES; NANORODS; GROWTH AB We report the synthesis of monodisperse Pt nanocrystals with three different shapes-cubes, cuboctahedra, and octahedra, selectively, with similar sizes of 9-10 nm by a modified polyol process. We found that addition of silver ion enhances the crystal growth rate along (100), and essentially determines the shape and surface structure of the Pt nanocrystals. After the reaction, the silver species can be easily removed by repetitive precipitation giving pure Pt nanoparticles. Two-dimensional arrays of the Pt nanocrystals were assembled by using the Langmuir-Blodgett (LB) method. The particles were evenly distributed on the entire substrate, and their surface coverage and density can be precisely controlled by tuning the surface pressure. The resulting Pt LB layers are potential candidates for 2-D model catalysts as a result of their high surface area and the structural uniformity of the metal nanocrystals. C1 Univ Calif Berkeley, Dept Chem, Div Mat Sci, Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. RP Yang, PD (reprint author), Univ Calif Berkeley, Dept Chem, Div Mat Sci, Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. EM p_yang@uclink.berkeley.edu RI Song, Hyunjoon/C-1638-2011; OI Song, Hyunjoon/0000-0002-1565-5697; Kim, Franklin/0000-0002-6548-6588 NR 44 TC 387 Z9 392 U1 22 U2 240 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 JAN 13 PY 2005 VL 109 IS 1 BP 188 EP 193 DI 10.1021/jp0464775 PG 6 WC Chemistry, Physical SC Chemistry GA 886FV UT WOS:000226213200033 PM 16851003 ER PT J AU Sullivan, VS Jackson, SD Stair, PC AF Sullivan, VS Jackson, SD Stair, PC TI Situ ultraviolet Raman spectroscopy of the reduction of chromia on alumina catalysts SO JOURNAL OF PHYSICAL CHEMISTRY B LA English DT Article ID METAL-OXIDE CATALYSTS; BED CR2O3/AL2O3 CATALYST; PROPANE DEHYDROGENATION; BUTENE-1 DEHYDROGENATION; COKE FORMATION; ALKANE DEHYDROGENATION; CRO3/AL2O3 CATALYSTS; ZIRCONIA CATALYSTS; MIXED-OXIDE; SPECTRA AB A fluidized bed in situ cell is used to examine the chromia on alumina catalyst surface. The loading is varied from 1 to 20% chromium oxide on alumina. The structure of the surface is monitored as a function of temperature, reduction, and hydration. This is the first study to use ultraviolet excitation to study a reduced chromium catalyst surface. Reduction of the sample in hydrogen gas leads to the formation of noncrystalline Cr3+ species. Addition of potassium to the surface reduces the size of the chromia clusters. C1 Northwestern Univ, Dept Chem, Evanston, IL 60208 USA. Northwestern Univ, Ctr Catalysis & Surface Sci, Evanston, IL 60208 USA. Argonne Natl Lab, Argonne, IL 60439 USA. Univ Glasgow, Dept Chem, Glasgow G12 8QQ, Lanark, Scotland. RP Stair, PC (reprint author), Northwestern Univ, Dept Chem, 2145 Sheridan Rd, Evanston, IL 60208 USA. EM pstair@northwestern.edu RI Jackson, Samuel/F-8095-2011 OI Jackson, Samuel/0000-0003-1257-5533 NR 45 TC 5 Z9 5 U1 0 U2 9 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 JAN 13 PY 2005 VL 109 IS 1 BP 352 EP 356 DI 10.1021/jp046610t PG 5 WC Chemistry, Physical SC Chemistry GA 886FV UT WOS:000226213200052 PM 16851022 ER PT J AU Vysotsky, YB Bryantsev, VS Boldyreva, FL Fainerman, VB Vollhardt, D AF Vysotsky, YB Bryantsev, VS Boldyreva, FL Fainerman, VB Vollhardt, D TI Quantum chemical semiempirical approach to the structural and thermodynamic characteristics of fluoroalkanols at the air/water interface SO JOURNAL OF PHYSICAL CHEMISTRY B LA English DT Article ID AB-INITIO; ALCOHOLS; POLY(TETRAFLUOROETHYLENE); PERFLUOROALKANES; DEPENDENCE; ENERGIES; CLUSTERS; CHAINS; MODEL AB In the framework of quantum chemical PM3 approximation, the geometrical structure and thermodynamic functions characteristics of the formation of monomers (n = 1-14, 34), dimers (it = 1-14, 34), and trimers and tetramers (it = 1-8) of fluoroalkanols with the composition CnF2n+1CH2CH2OH are calculated. It is shown that, in contrast to the fatty alcohols, which have a flat zigzag structure, the fluoroalkanol monomers are helical with an average backbone torsion angle equal to 162degrees. For the minimum-energy structure of dimers, the self-organization of the molecules in a dimer was observed; that leads to an opposite alternation of the torsion angles corresponding to the matching atoms in the two molecules that form the dimer. This results in the fact that the most stable conformation of the dimer is the double helix. The lead (39.5 A) and diameter (7.3 A) of the double helix are determined from the calculations Of C34F69CH2CH2OH dimers. Enthalpy, entropy, and Gibbs energy of the clusterization are shown to be linearly dependent on the length of the fluorinated chain. From the analysis of these thermodynamic quantities, it is concluded that dimerization of fluoroalkanols at the air/water interface takes place if the hydrocarbon link number exceeds 6, whereas for ordinary alcohols this characteristic number is 11. These calculated values agree with experimental data. The additive scheme for the evaluation of the clusterization free energies for arbitrary clusters is developed and applied to obtain the estimate of the Gibbs clusterization energy for infinitely large clusters. C1 Donetsk State Univ Econ & Trade, UA-83050 Donetsk, Ukraine. Pacific NW Natl Lab, Richland, WA 99352 USA. Donbas Acad Civil Engn & Architecture, UA-86123 Makiyivka, Ukraine. Donetsk Med Univ, Med Physicochem Ctr, UA-83003 Donetsk, Ukraine. Max Planck Inst Colloids & Interfaces, D-14424 Potsdam, Germany. RP Vollhardt, D (reprint author), Donetsk State Univ Econ & Trade, 31 Shchorsa Str, UA-83050 Donetsk, Ukraine. RI Vysotsky, Yuri/Q-1338-2015; Bryantsev, Vyacheslav/M-5111-2016 OI Vysotsky, Yuri/0000-0001-7645-7419; Bryantsev, Vyacheslav/0000-0002-6501-6594 NR 24 TC 19 Z9 19 U1 0 U2 2 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 JAN 13 PY 2005 VL 109 IS 1 BP 454 EP 462 DI 10.1021/jp048240e PG 9 WC Chemistry, Physical SC Chemistry GA 886FV UT WOS:000226213200066 PM 16851036 ER PT J AU Hadjidakis, C Guidal, M Garcon, M Laget, JM Smith, ES Vanderhaeghen, M Adams, G Ambrozewicz, P Anciant, E Anghinolfi, M Asavapibhop, B Asryan, G Audit, G Auger, T Avakian, H Bagdasaryan, H Ball, JP Barrow, S Battaglieri, M Beard, K Bektasoglu, M Bellis, M Benmouna, N Bianchi, N Biselli, AS Boiarinov, S Bonner, BE Bouchigny, S Bradford, R Branford, D Briscoe, WJ Brooks, WK Burkert, VD Butuceanu, C Calarco, JR Carman, DS Carnahan, B Cetina, C Chen, S Cole, PL Coleman, A Cords, D Corvisiero, P Crabb, D Crannell, H Cununings, JP De Sanctis, E DeVita, R Degtyarenko, PV Dennis, L Dharmawardane, KV Dhuga, KS Didelez, JP Djalali, C Dodge, GE Doughty, D Dragovitsch, P Dugger, M Dytman, S Dzyubak, OP Egiyan, H Egiyan, KS Elouadrhiri, L Empl, A Eugenio, P Farhi, L Fatemi, R Feuerbach, RJ Forest, TA Frolov, V Funsten, H Gaff, SJ Gavalian, G Gilfoyle, GP Giovanetti, KL Girard, P Gordon, CIO Gothe, RW Griffioen, KA Guillo, M Guler, M Guo, L Gyurjyan, V Hakobyan, RS Hardie, J Heddle, D Hersman, FW Hicks, K Hleiqawi, H Holtrop, M Hourany, E Hu, J Hyde-Wright, CE Ilieva, Y Ireland, D Ito, MM Jenkins, D Jo, HS Joo, K Juengst, HG Kelley, JH Kellie, J Khandaker, M Kim, KY Kim, K Kim, W Klein, A Klein, FJ Klimenko, AV Klusman, M Kossov, M Kramer, LH Kuhn, SE Kuhn, J Lachniet, J Langheinrich, J Lawrence, D Lee, T Li, J Livingstone, K Lukashin, K Manak, JJ Marchand, C McAleer, S McNabb, JWC Mecking, BA Melone, JJ Mestayer, MD Meyer, CA Mikhailov, K Minehart, R Mirazita, M Miskimen, R Morand, L Morrow, SA Muccifora, V Mueller, J Mutchler, GS Napolitano, J Nasseripour, R Nelson, SO Niccolai, S Niculescu, G Niculescu, I Niczyporuk, BB Niyazov, RA Nozar, M O'Rielly, GV Osipenko, M Park, K Pasyuk, E Peterson, G Philips, SA Pivnyuk, N Pocanic, D Pogorelko, O Polli, E Pozdniakov, S Preedom, BM Price, JW Prok, Y Protopopescu, D Qin, LM Raue, BA Riccardi, G Ricco, G Ripani, M Ritchie, BG Ronchetti, F Rossi, P Rosner, G Rowntree, D Rubin, PD Sabatie, F Sabourov, K Salgado, C Santoro, JP Sapunenko, V Schumacher, RA Serov, VS Sharabian, YG Shaw, J Simionatto, S Skabelin, AV Smith, LC Sober, DI Spraker, M Stavinsky, A Stepanyan, S Stokes, BE Stoler, P Strauch, S Taiuti, M Taylor, S Tedeschi, DJ Thoma, U Thompson, R Tkabladze, A Todor, L Tur, C Ungaro, M Vineyard, MF Vlassov, AV Wang, K Weinstein, LB Weller, H Weygand, DP Whisnant, CS Williams, M Wolin, E Wood, MH Yegneswaran, A Yun, J Zana, L AF Hadjidakis, C Guidal, M Garcon, M Laget, JM Smith, ES Vanderhaeghen, M Adams, G Ambrozewicz, P Anciant, E Anghinolfi, M Asavapibhop, B Asryan, G Audit, G Auger, T Avakian, H Bagdasaryan, H Ball, JP Barrow, S Battaglieri, M Beard, K Bektasoglu, M Bellis, M Benmouna, N Bianchi, N Biselli, AS Boiarinov, S Bonner, BE Bouchigny, S Bradford, R Branford, D Briscoe, WJ Brooks, WK Burkert, VD Butuceanu, C Calarco, JR Carman, DS Carnahan, B Cetina, C Chen, S Cole, PL Coleman, A Cords, D Corvisiero, P Crabb, D Crannell, H Cununings, JP De Sanctis, E DeVita, R Degtyarenko, PV Dennis, L Dharmawardane, KV Dhuga, KS Didelez, JP Djalali, C Dodge, GE Doughty, D Dragovitsch, P Dugger, M Dytman, S Dzyubak, OP Egiyan, H Egiyan, KS Elouadrhiri, L Empl, A Eugenio, P Farhi, L Fatemi, R Feuerbach, RJ Forest, TA Frolov, V Funsten, H Gaff, SJ Gavalian, G Gilfoyle, GP Giovanetti, KL Girard, P Gordon, CIO Gothe, RW Griffioen, KA Guillo, M Guler, M Guo, L Gyurjyan, V Hakobyan, RS Hardie, J Heddle, D Hersman, FW Hicks, K Hleiqawi, H Holtrop, M Hourany, E Hu, J Hyde-Wright, CE Ilieva, Y Ireland, D Ito, MM Jenkins, D Jo, HS Joo, K Juengst, HG Kelley, JH Kellie, J Khandaker, M Kim, KY Kim, K Kim, W Klein, A Klein, FJ Klimenko, AV Klusman, M Kossov, M Kramer, LH Kuhn, SE Kuhn, J Lachniet, J Langheinrich, J Lawrence, D Lee, T Li, J Livingstone, K Lukashin, K Manak, JJ Marchand, C McAleer, S McNabb, JWC Mecking, BA Melone, JJ Mestayer, MD Meyer, CA Mikhailov, K Minehart, R Mirazita, M Miskimen, R Morand, L Morrow, SA Muccifora, V Mueller, J Mutchler, GS Napolitano, J Nasseripour, R Nelson, SO Niccolai, S Niculescu, G Niculescu, I Niczyporuk, BB Niyazov, RA Nozar, M O'Rielly, GV Osipenko, M Park, K Pasyuk, E Peterson, G Philips, SA Pivnyuk, N Pocanic, D Pogorelko, O Polli, E Pozdniakov, S Preedom, BM Price, JW Prok, Y Protopopescu, D Qin, LM Raue, BA Riccardi, G Ricco, G Ripani, M Ritchie, BG Ronchetti, F Rossi, P Rosner, G Rowntree, D Rubin, PD Sabatie, F Sabourov, K Salgado, C Santoro, JP Sapunenko, V Schumacher, RA Serov, VS Sharabian, YG Shaw, J Simionatto, S Skabelin, AV Smith, LC Sober, DI Spraker, M Stavinsky, A Stepanyan, S Stokes, BE Stoler, P Strauch, S Taiuti, M Taylor, S Tedeschi, DJ Thoma, U Thompson, R Tkabladze, A Todor, L Tur, C Ungaro, M Vineyard, MF Vlassov, AV Wang, K Weinstein, LB Weller, H Weygand, DP Whisnant, CS Williams, M Wolin, E Wood, MH Yegneswaran, A Yun, J Zana, L TI Exclusive rho(0) meson electroproduction from hydrogen at CLAS SO PHYSICS LETTERS B LA English DT Article ID VIRTUAL COMPTON-SCATTERING; VECTOR-MESONS; ELASTIC ELECTROPRODUCTION; DIFFRACTIVE PRODUCTION; PARTON DISTRIBUTIONS; HIGH-ENERGIES; LARGE Q(2); NUCLEON; PHOTOPRODUCTION; PHOTONS AB The longitudinal and transverse components of the cross section for the ep --> e' prho(0) reaction were measured in Hall B at Jefferson Laboratory using the CLAS detector. The data were taken with a 4.247 GeV electron beam and were analyzed in a range of x(B) from 0.2 to 0.6 and of Q(2) from 1.5 to 3.0 GeV2. The data are compared to a Regge model based on effective hadronic degrees of freedom and to a calculation based on Generalized Parton Distributions. It is found that, at our lowest x(B) values, the transverse part of the cross section is well described by the former approach while the longitudinal part can be reproduced by the latter. (C) 2004 Elsevier B.V. All rights reserved. C1 Inst Phys Nucl, F-91406 Orsay, France. Ist Nazl Fis Nucl, Lab Nazl Frascati, I-00044 Frascati, Italy. CEA Saclay, Serv Phys Nucl, F-91191 Gif Sur Yvette, France. Thomas Jefferson Natl Accelerator Fac, Newport News, VA 23606 USA. Coll William & Mary, Williamsburg, VA 23187 USA. Arizona State Univ, Tempe, AZ 85287 USA. Univ Calif Los Angeles, Los Angeles, CA 90095 USA. Carnegie Mellon Univ, Pittsburgh, PA 15213 USA. Catholic Univ Amer, Washington, DC 20064 USA. Christopher Newport Univ, Newport News, VA 23606 USA. Univ Connecticut, Storrs, CT 06269 USA. Duke Univ, Durham, NC 27708 USA. Univ Edinburgh, Edinburgh EH9 3JZ, Midlothian, Scotland. Florida Int Univ, Miami, FL 33199 USA. Florida State Univ, Tallahassee, FL 32306 USA. Univ Giessen, Inst Phys, D-35392 Giessen, Germany. George Washington Univ, Washington, DC 20052 USA. Univ Glasgow, Glasgow G12 8QQ, Lanark, Scotland. Ist Nazl Fis Nucl, Sez FEnova, I-16146 Genoa, Italy. Inst Theoret & Expt Phys, Moscow 117259, Russia. James Madison Univ, Harrisonburg, VA 22807 USA. Kyungpook Natl Univ, Taegu 702701, South Korea. MIT, Cambridge, MA 02139 USA. Univ Massachusetts, Amherst, MA 01003 USA. Univ New Hampshire, Durham, NH 03824 USA. Norfolk State Univ, Norfolk, VA 23504 USA. Ohio Univ, Athens, OH 45701 USA. Old Dominion Univ, Norfolk, VA 23529 USA. Penn State Univ, University Pk, PA 15260 USA. Univ Pittsburgh, Pittsburgh, PA 15260 USA. Rensselaer Polytech Inst, Troy, NY 12180 USA. Univ Rome III, I-00146 Rome, Italy. Rice Univ, Houston, TX 77005 USA. Univ Richmond, Richmond, VA 23173 USA. Univ S Carolina, Columbia, SC 29208 USA. Union Coll, Schenectady, NY 12308 USA. Virginia Polytech Inst & State Univ, Blacksburg, VA 24061 USA. Univ Virginia, Charlottesville, VA 22901 USA. RP Hadjidakis, C (reprint author), Inst Phys Nucl, BP 1, F-91406 Orsay, France. EM guidal@ipno.in2p3.fr RI Ireland, David/E-8618-2010; Bektasoglu, Mehmet/A-2074-2012; Protopopescu, Dan/D-5645-2012; riccardi, gabriele/A-9269-2012; Zana, Lorenzo/H-3032-2012; Brooks, William/C-8636-2013; Schumacher, Reinhard/K-6455-2013; Auger, Thierry/L-1073-2013; Meyer, Curtis/L-3488-2014; Sabatie, Franck/K-9066-2015; Osipenko, Mikhail/N-8292-2015; OI Bellis, Matthew/0000-0002-6353-6043; Ireland, David/0000-0001-7713-7011; Brooks, William/0000-0001-6161-3570; Schumacher, Reinhard/0000-0002-3860-1827; Meyer, Curtis/0000-0001-7599-3973; Sabatie, Franck/0000-0001-7031-3975; Osipenko, Mikhail/0000-0001-9618-3013; Hyde, Charles/0000-0001-7282-8120 NR 44 TC 32 Z9 32 U1 1 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0370-2693 J9 PHYS LETT B JI Phys. Lett. B PD JAN 13 PY 2005 VL 605 IS 3-4 BP 256 EP 264 DI 10.1016/j.physletb.2004.11.019 PG 9 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 887OA UT WOS:000226314200005 ER PT J AU Taylor, MJ Benczer-Koller, N Bernstein, L Cooper, J Hiles, K Judson, DS Kumbartzki, G Maier-Komor, P McMahan, MA Mertzimekis, TJ Phair, L Robinson, SJQ Sharon, YY Speidel, KH Stuchbery, AE Zamick, L AF Taylor, MJ Benczer-Koller, N Bernstein, L Cooper, J Hiles, K Judson, DS Kumbartzki, G Maier-Komor, P McMahan, MA Mertzimekis, TJ Phair, L Robinson, SJQ Sharon, YY Speidel, KH Stuchbery, AE Zamick, L TI Shell model configurations in the 2(1)(+) state in Ca-46 from a g-factor measurement SO PHYSICS LETTERS B LA English DT Article DE g factor; Ca-46; Coulomb excitation; inverse kinematics; magnetic moment; transient field ID MAGNETIC-MOMENTS; CALCIUM ISOTOPES; NUCLEAR MOMENTS; DEFORMED STATES; EXCITATION; CORE; IONS AB The g factor of the first excited 2(1)(+) state in Ca-46 has been remeasured with better accuracy than previously obtained, g(2(1)(+), Ca-46) = -0.26(6). The experiment utilized the transient field technique combined with Coulomb excitation in inverse kinematics. This result was analyzed in terms of shell model plus deformed core calculations. The positive g factors of the 2(1)(+) states in Ca-42 and Ca-44 suggest that the 2(1)(+) state wave functions require significant particle-hole excitations of the Z = 20, N = 20 core. The new data for Ca-46 show that (fp)(v)(6) configurations dominate near the shell closure at Ca-48 and indicate that core excitation plays a lesser role than was hitherto believed. (C) 2004 Elsevier B.V. All rights reserved. C1 Univ Brighton, Sch Engn, Brighton BN2 4GJ, E Sussex, England. Rutgers State Univ, Dept Phys & Astron, New Brunswick, NJ 08903 USA. Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. Tech Univ Munich, Dept Phys, D-85748 Garching, Germany. Lawrence Berkeley Lab, Berkeley, CA 94720 USA. Michigan State Univ, NSCL, E Lansing, MI 48824 USA. Univ So Indiana, Dept Geol & Phys, Evansville, IN 47712 USA. Univ Bonn, Helmholtz Inst Strahlen & Kernphys, D-53115 Bonn, Germany. Australian Natl Univ, Dept Phys Nucl, Canberra, ACT 0200, Australia. RP Taylor, MJ (reprint author), Univ Brighton, Sch Engn, Brighton BN2 4GJ, E Sussex, England. EM m.j.taylor@brighton.ac.uk RI Mertzimekis, Theo/A-3287-2008; Taylor, Michael/N-1725-2015 OI Mertzimekis, Theo/0000-0001-9191-7903; Taylor, Michael/0000-0002-8718-3684 NR 30 TC 15 Z9 16 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0370-2693 J9 PHYS LETT B JI Phys. Lett. B PD JAN 13 PY 2005 VL 605 IS 3-4 BP 265 EP 272 DI 10.1016/j.physletb.2004.11.021 PG 8 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 887OA UT WOS:000226314200006 ER PT J AU Chen, MJ Zhang, DX Keller, AA Lu, ZM AF Chen, MJ Zhang, DX Keller, AA Lu, ZM TI A stochastic analysis of steady state two-phase flow in heterogeneous media SO WATER RESOURCES RESEARCH LA English DT Article ID FRACTURED POROUS-MEDIA; UNSATURATED FLOW; 3-PHASE FLOW; NONSTATIONARY AB [1] We present a novel approach to modeling stochastic multiphase flow problems, for example, nonaqueous phase liquid flow, in a heterogeneous subsurface medium with random soil properties, in particular, with randomly heterogeneous intrinsic permeability and soil pore size distribution. A stochastic numerical model for steady state water-oil flow in a random soil property field is developed using the Karhunen-Loeve moment equation (KLME) approach and is numerically implemented. An exponential model is adopted to define the constitutive relationship between phase relative permeability and capillary pressure. The log-transformed intrinsic permeability Y(x) and soil pore size distribution beta(x) are assumed to be Gaussian random functions with a separable exponential covariance function. The perturbation part of these two log-transformed soil properties is then decomposed into an infinite series based on a set of orthogonal normal random variables {xi(n)}. The phase pressure, capillary pressure, and phase mobility are decomposed by polynomial expansions and the perturbation method. Combining these expansions of Y(x), beta(x) and dependent pressures, the steady state water-oil flow equations and corresponding boundary conditions are reformulated as a series of differential equations up to second order. These differential equations are solved numerically, and the solutions are directly used to construct moments of phase pressure and capillary pressure. We demonstrate the validity of the proposed KLME model by favorably comparing first- and second-order approximations to Monte Carlo simulations. The significant computational efficiency of the KLME approach over Monte Carlo simulation is also illustrated. C1 Univ Calif Santa Barbara, Bren Sch Environm Sci & Management, Santa Barbara, CA 93106 USA. Los Alamos Natl Lab, Hydrol Geochem & Geol Grp, Los Alamos, NM 87545 USA. Univ Oklahoma, Mewbourne Sch Petr & Geol Engn, Norman, OK 73019 USA. RP Chen, MJ (reprint author), Univ Calif Santa Barbara, Bren Sch Environm Sci & Management, Santa Barbara, CA 93106 USA. EM mchen@bren.ucsb.edu; donzhang@ou.edu; keller@bren.ucsb.edu; zhiming@lanl.gov RI Zhang, Dongxiao/D-5289-2009 OI Zhang, Dongxiao/0000-0001-6930-5994 NR 31 TC 18 Z9 18 U1 1 U2 5 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0043-1397 J9 WATER RESOUR RES JI Water Resour. Res. PD JAN 13 PY 2005 VL 41 IS 1 AR W01006 DI 10.1029/2004WR003412 PG 14 WC Environmental Sciences; Limnology; Water Resources SC Environmental Sciences & Ecology; Marine & Freshwater Biology; Water Resources GA 890ZC UT WOS:000226549500001 ER PT J AU Guo, JH Vayssieres, L Persson, C Ahuja, R Johansson, B Nordgren, J AF Guo, JH Vayssieres, L Persson, C Ahuja, R Johansson, B Nordgren, J TI Polarization-dependent soft-x-ray absorption of a highly oriented ZnO microrod-array SO JOURNAL OF PHYSICS-CONDENSED MATTER LA English DT Article ID AQUEOUS CHEMICAL GROWTH; ROOM-TEMPERATURE; FILMS AB Polarization-dependent x-ray absorption measurements were performed on a crystalline ZnO three-dimensional array consisting of highly oriented microrods as well as on particulate thin film consisting of monodisperse spherical nanoparticles. Strong anisotropic effects have been observed for the highly oriented ZnO rods, unlike for the isotropic spherical ones. Full-potential calculations of orbital-resolved x-ray absorption of a ZnO wurtzite periodic crystal, including the Zn 3d as part of the valence states, shows a very good agreement with the experimental findings. Comprehensive fundamental knowledge of the electronic structure of ZnO is obtained by probing and demonstrating the orbital symmetry of oxygen and its contribution to the conduction band of this important II-VI semiconductor. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Adv Light Source, Berkeley, CA 94720 USA. Uppsala Univ, Dept Phys, SE-75121 Uppsala, Sweden. Univ Texas, Dept Mat Sci & Engn, Austin, TX 78712 USA. RP Guo, JH (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Adv Light Source, Berkeley, CA 94720 USA. NR 17 TC 4 Z9 4 U1 1 U2 7 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 JAN 12 PY 2005 VL 17 IS 1 BP 235 EP 240 DI 10.1088/0953-8984/17/1/022 PG 6 WC Physics, Condensed Matter SC Physics GA 892DS UT WOS:000226630600024 PM 21690683 ER PT J AU Zuo, XB Tiede, DM AF Zuo, XB Tiede, DM TI Resolving conflicting crystallographic and NMR models for solution-state DNA with solution X-ray diffraction SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Article ID CHEMICAL-SHIFT ANISOTROPY; DIPOLAR COUPLINGS; DODECAMER; DYNAMICS; SCATTERING; SEQUENCE C1 Argonne Natl Lab, Chem Div, Argonne, IL 60439 USA. RP Tiede, DM (reprint author), Argonne Natl Lab, Chem Div, 9700 S Cass Ave, Argonne, IL 60439 USA. EM tiede@anl.gov RI Zuo, Xiaobing/F-1469-2010; OI Zuo, Xiaobing/0000-0002-0134-4804 NR 22 TC 23 Z9 24 U1 1 U2 6 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0002-7863 J9 J AM CHEM SOC JI J. Am. Chem. Soc. PD JAN 12 PY 2005 VL 127 IS 1 BP 16 EP 17 DI 10.1021/ja044533+ PG 2 WC Chemistry, Multidisciplinary SC Chemistry GA 886PN UT WOS:000226240900007 PM 15631426 ER PT J AU Maron, L Werkema, EL Perrin, L Eisenstein, O Andersen, RA AF Maron, L Werkema, EL Perrin, L Eisenstein, O Andersen, RA TI Hydrogen for fluorine exchange in C6F6 and C6F5H by monomeric [1,3,4-(Me3C)(3)C5H2](2)CeH: Experimental and computational studies SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Article ID F BOND ACTIVATION; SOLID-STATE STRUCTURES; C-H ACTIVATION; CRYSTAL-STRUCTURE; HYDRIDE COMPLEXES; METATHESIS REACTIONS; OXIDATIVE ADDITION; ARYNE CHEMISTRY; METAL-COMPLEXES; H/D EXCHANGE AB The net reaction of monomeric CP'2CeH [Cp' = 1,3,4-(Me3C)(3)(C5H2)] in C6D6 with C6F6 is CP'2CeF, H-2, and tetrafluorobenzyne. The pentafluoropheny/metallocene, CP'Ce-2(C6F5), is formed as an intermediate that decomposes slowly to CP'2CeF and C6F4 (tetrafluorobenzyne), and the latter is trapped by the solvent C6D6 as a [2+4] cycloadcluct. In C6F5H, the final products are also CP'2CeF and H-2, which are formed from the intermediates CP'Ce-2(C6F5) and CP'Ce-2(2,3,5,6-C6F4H) and from an unidentified metallocene of cerium and the [2+4] cycloadducts of tetra- and trifluorobenzyne with C6D6. The hydride, fluoride, and pentafluoropheny/metallocenes are isolated and characterized by X-ray crystallography. DFT(B3PW91) calculations have been used to explore the pathways leading to the observed products of the exergonic reactions. A key step is a H/F exchange reaction which transforms C6F6 and the cerium hydride into C6F5H and CP'2CeF. This reaction starts by an eta(1)-F-C6F5 interaction, which serves as a hook. The reaction proceeds via a sigma bond metathesis where the fluorine ortho to the hook migrates toward H with a relatively low activation energy. All products observed experimentally are accommodated by pathways that involve C-F and C-H bond cleavages. C1 Univ Toulouse 3, IRSAMC, Lab Phys Quant, UMR 5626, F-31064 Toulouse 4, France. Univ Calif Berkeley, Lawrence Berkeley Lab, Dept Chem, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Chem Sci, Berkeley, CA 94720 USA. Univ Montpellier 2, LSDSMS, UMR 5636, F-34095 Montpellier 5, France. RP Maron, L (reprint author), Univ Toulouse 3, IRSAMC, Lab Phys Quant, UMR 5626, 118 Route Narbonne, F-31064 Toulouse 4, France. EM laurent.maron@irsamc.ups-tlse.fr; odile.eisenstein@univ-montp2.fr; raandersen@lbl.gov RI Perrin, Lionel/B-6456-2009; Eisenstein, Odile/I-1704-2016; PERRIN, Lionel/N-9323-2013 OI Eisenstein, Odile/0000-0001-5056-0311; PERRIN, Lionel/0000-0002-0702-8749 NR 83 TC 138 Z9 138 U1 0 U2 14 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0002-7863 J9 J AM CHEM SOC JI J. Am. Chem. Soc. PD JAN 12 PY 2005 VL 127 IS 1 BP 279 EP 292 DI 10.1021/ja0451012 PG 14 WC Chemistry, Multidisciplinary SC Chemistry GA 886PN UT WOS:000226240900058 PM 15631477 ER PT J AU Mozharivskyj, Y Pecharsky, AO Pecharsky, VK Miller, GJ AF Mozharivskyj, Y Pecharsky, AO Pecharsky, VK Miller, GJ TI On the high-temperature phase transition of Gd5Si2Ge2 SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Article ID ELECTRICAL-RESISTANCE; ELECTRONIC-STRUCTURE; CRYSTAL-STRUCTURE; MAGNETIC-FIELD; GD-5(SIXGE1-X)(4); GD-5(SI2GE2); SYSTEM; GD5SI4-GD5GE4; BEHAVIOR AB The first-order monoclinic-to-orthorhombic (beta-->gamma) phase transition of the giant magnetocaloric material Gd5Si2Ge2 was studied using in situ high-temperature single-crystal X-ray diffraction. A special crystal mounting procedure was developed to avoid crystal contamination by oxygen or nitrogen at high temperatures. The elastic beta-->gamma transformation occurs at 300-320 degreesC during heating, and it is reversible during fast and slow heating and slow cooling but irreversible during rapid cooling. Contrary to theoretical predictions, the macroscopic distribution of the Si and Ge atoms remains the same in both the orthorhombic gamma-polymorph and the monoclinic beta-phase. It appears that interstitial impurities may affect stability of both the monoclinic and orthorhombic phases. In the presence of small amounts of air, the beta-->gamma transformation is complete only at 600 degreesC. The interslab voids, which can accommodate impurity atoms, have been located in the structure, and an effect of partially filling these voids with oxygen or nitrogen atoms on the beta-->gamma transition is discussed. C1 Iowa State Univ, Dept Chem, Ames, IA 50011 USA. Iowa State Univ, Dept Mat Sci & Engn, Ames, IA 50011 USA. Iowa State Univ, Ames Lab, Mat & Engn Phys Program, Ames, IA 50011 USA. RP Iowa State Univ, Dept Chem, Ames, IA 50011 USA. EM gmiller@iastate.edu NR 26 TC 52 Z9 53 U1 1 U2 14 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0002-7863 J9 J AM CHEM SOC JI J. Am. Chem. Soc. PD JAN 12 PY 2005 VL 127 IS 1 BP 317 EP 324 DI 10.1021/ja048679k PG 8 WC Chemistry, Multidisciplinary SC Chemistry GA 886PN UT WOS:000226240900062 PM 15631481 ER PT J AU Dillon, AC Parilla, PA Alleman, JL Gennett, T Jones, KM Heben, MJ AF Dillon, AC Parilla, PA Alleman, JL Gennett, T Jones, KM Heben, MJ TI Systematic inclusion of defects in pure carbon single-wall nanotubes and their effect on the Raman D-band SO CHEMICAL PHYSICS LETTERS LA English DT Article ID SPECTROSCOPY; SCATTERING; GRAPHITE AB The Raman D-band feature (similar to1350 cm(-1)) is examined with 2.54 eV excitation for pure bulk carbon single-wall nanotube samples before and after treatments that increase defect densities. Upon employing mass-transport-limited oxidation to introduce defects, the D-band intensity increases approximately linearly with reaction time. A relatively constant ratio of the D-band intensity and the major tangential G-band intensity (D/G) is observed for the purified samples examined at 2.54 and 1.96 eV suggesting a characteristic number of defects is introduced for given synthesis and purification processes. The D/G ratio is similar to1/190 and 1/40 for excitation at 2.54 and 1.96 eV, respectively. (C) 2004 Elsevier B.V. All rights reserved. C1 Natl Renewable Energy Lab, Golden, CO 80401 USA. RP Dillon, AC (reprint author), Natl Renewable Energy Lab, 1617 Cole Blvd, Golden, CO 80401 USA. EM adillon@nrel.gov NR 23 TC 78 Z9 79 U1 0 U2 14 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 JAN 11 PY 2005 VL 401 IS 4-6 BP 522 EP 528 DI 10.1016/j.cplett.2004.11.104 PG 7 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 886YT UT WOS:000226269800037 ER PT J AU Park, SH Shin, HS Myung, ST Yoon, CS Amine, K Sun, YJ AF Park, SH Shin, HS Myung, ST Yoon, CS Amine, K Sun, YJ TI Synthesis of nanostructured Li[Ni1/3Co1/3Mn1/3]O-2 via a modified carbonate process SO CHEMISTRY OF MATERIALS LA English DT Article ID ION BATTERIES; HIGH-CAPACITY; CATHODE; PERFORMANCE; OXIDES C1 Hanyang Univ, Dept Chem Engn, Seoul 133791, South Korea. Hanyang Univ, Dept Mat Sci & Engn, Ctr Informat & Commun Mat, Seoul 133791, South Korea. VK Corp, Pyongtaek City 450090, South Korea. Argonne Natl Lab, Div Chem Engn, Electrochem Technol Program, Argonne, IL 60439 USA. RP Sun, YJ (reprint author), Hanyang Univ, Dept Chem Engn, Seoul 133791, South Korea. EM yksun@hanyang.ac.kr RI Sun, Yang-Kook/B-9157-2013; Amine, Khalil/K-9344-2013 OI Sun, Yang-Kook/0000-0002-0117-0170; NR 12 TC 146 Z9 152 U1 4 U2 34 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 JAN 11 PY 2005 VL 17 IS 1 BP 6 EP 8 DI 10.1021/cm048433e PG 3 WC Chemistry, Physical; Materials Science, Multidisciplinary SC Chemistry; Materials Science GA 886KS UT WOS:000226226700003 ER PT J AU Chaiko, DJ Leyva, AA AF Chaiko, DJ Leyva, AA TI Thermal transitions and barrier properties of olefinic nanocomposites SO CHEMISTRY OF MATERIALS LA English DT Article AB Differential scanning calorimetry (DSC) was used to study the thermal transitions of smectite organoclays and their dispersions in olefinic systems, which included paraffinic waxes and polyethylene. The organoclays, with treatment on both the basal and edge Surfaces, produced nanocscale dispersions without the aid of external coupling agents or compatibilizers. In addition to DSC measurements, the nanocomposites were further characterized using X-ray diffraction and oxygen transmission. The DSC measurements indicated that a clay/wax nanocomposite phase was generated with melt/freeze transition temperatures that were different from those of the individual components, while X-ray data indicated that the nanocomposite phase was in equilibrium with an intercalate phase. Barrier improvement of over 300x was observed and ascribed to a tortuosity effect resulting from dispersed clay platelets having a high aspect ratio and strong cohesion between the wax and the organoclay surface. Available data indicate that the barrier enhancement decreases as the difference between the freezing points of the organoclay and the wax widens. The cause of poor barrier performance in polyolefin systems is traced to the large difference in recrystallization temperatures, such that when the polymer begins to crystallize the surface of the organoclay is still in a liquid state, which leads to phase separation. C1 Argonne Natl Lab, Div Chem Engn, Argonne, IL 60439 USA. RP Chaiko, DJ (reprint author), Argonne Natl Lab, Div Chem Engn, 9700 S Cass Ave, Argonne, IL 60439 USA. EM chaiko@cmt.ant.gov NR 14 TC 65 Z9 65 U1 3 U2 12 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 JAN 11 PY 2005 VL 17 IS 1 BP 13 EP 19 DI 10.1021/cm0302680 PG 7 WC Chemistry, Physical; Materials Science, Multidisciplinary SC Chemistry; Materials Science GA 886KS UT WOS:000226226700005 ER PT J AU Chakraborty, S Sahoo, B Teraoka, I Miller, LM Gross, RA AF Chakraborty, S Sahoo, B Teraoka, I Miller, LM Gross, RA TI Enzyme-catalyzed regioselective modification of starch nanoparticles SO MACROMOLECULES LA English DT Article ID RING-OPENING POLYMERIZATION; ANTARTICA LIPASE B; ORGANIC-SOLVENTS; DELIVERY; RELEASE; DRUGS; AMYLOSE; WATER; CARRIERS; SYSTEM AB The selective esterification of starch nanoparticles was performed using as catalyst Candida antartica Lipase B (CAL-B) in its immobilized (Novozym. 435) and free (SP-525) forms. The starch nanoparticles were made accessible for acylation reactions by formation of Aerosol-OT (AOT, bis(2-ethylhexyl)sodium sulfosuccinate) stabilized microemulsions. Starch nanoparficleS in microemulsions were. reacted with vinyl stearate, epsilon-caprolactone, and maleic anhydride at 40 degreesC for 48 h to give. Starch esters with degrees of substitution (DS) of 0.8, 0.6, and 0.4, respectively. Substitution occurred reposelectively at the C-6 position of the glucose repeat units. Infrared microspectroscopy (IMMS) revealed that AOT-coated starch nanoparticles diffuse into the outer 50 mum shell of catalyst beads. Thus. even ihough CAL-B is immobilized within a macroporous resin, CAL-B Is sufficiently accessible to the starch nanoparticleS. When free CAL-B was incorporated along with starch within AOT-coated reversed tnicelleS.. CAL-B was: also active and catalyzed the acylation with vinyl stearate (24 h, 40 degreesC) to give DS = 0.5. -Aliter removal of surfactant from the modified starch nanoparticles, the.), were dispersed in DMSO or water and were T shown to retain their nanodimensions. C1 Polytech Univ, NSF, Ctr Biocatalysis & Bioproc Macromol, Othmer Dept Chem & Biol Sci & Engn, Brooklyn, NY 11201 USA. Brookhaven Natl Lab, Natl Synchrotron Light Source, Upton, NY 11973 USA. RP Gross, RA (reprint author), Polytech Univ, NSF, Ctr Biocatalysis & Bioproc Macromol, Othmer Dept Chem & Biol Sci & Engn, 6 Metrotech Ctr, Brooklyn, NY 11201 USA. EM rgross@poly.edu NR 31 TC 60 Z9 68 U1 1 U2 38 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0024-9297 J9 MACROMOLECULES JI Macromolecules PD JAN 11 PY 2005 VL 38 IS 1 BP 61 EP 68 DI 10.1021/ma048842w PG 8 WC Polymer Science SC Polymer Science GA 885QX UT WOS:000226173100011 ER PT J AU Mendez, S Curro, JG McCoy, JD Lopez, GP AF Mendez, S Curro, JG McCoy, JD Lopez, GP TI Computational modeling of the temperature-induced structural changes of tethered poly(N-isopropylacrylamide) with self-consistent field theory SO MACROMOLECULES LA English DT Article ID DENSITY-FUNCTIONAL THEORY; DIBLOCK COPOLYMER MONOLAYERS; GRAFTED POLYMER BRUSHES; MOLECULAR-DYNAMICS SIMULATION; TERMINALLY ATTACHED CHAINS; MONTE-CARLO SIMULATION; PHASE-TRANSITIONS; SLIT PORE; N-ISOPROPYLACRYLAMIDE; CONFORMATIONAL-CHANGE AB We modeled the effects of temperature, degree of polymerization, and surface coverage on the equilibrium structure of tethered poly(N-isopropylacrylamide) chains immersed in water. We employed a numerical self-consistent field theory where the experimental phase diagram was used as input to the theory. At low temperatures, the composition profiles are approximately parabolic and extend into the solvent. In contrast, at temperatures above the LCST of the bulk solution, the polymer profiles are collapsed near the surface. The layer thickness and the effective monomer fraction within the layer undergo what appears to be a first-order change at a temperature that depends on surface coverage and chain length. Our results suggest that as a result of the tethering constraint, the phase diagram becomes distorted relative to the bulk polymer solution and exhibits closed loop behavior. As a consequence, we find that the relative magnitude of the layer thickness change at 20 and 40 degreesC is a nonmonotonic function of surface coverage, with a maximum that shifts to lower surface coverage as the chain length increases in qualitative agreement with experiment. C1 Univ New Mexico, Dept Chem & Nucl Engn, Albuquerque, NM 87131 USA. Sandia Natl Labs, Albuquerque, NM 87185 USA. New Mexico Inst Min & Technol, Dept Mat & Met Engn, Socorro, NM 87801 USA. RP Curro, JG (reprint author), Univ New Mexico, Dept Chem & Nucl Engn, Albuquerque, NM 87131 USA. RI McCoy, John/B-3846-2010 OI McCoy, John/0000-0001-5404-1404 NR 67 TC 52 Z9 52 U1 0 U2 21 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0024-9297 J9 MACROMOLECULES JI Macromolecules PD JAN 11 PY 2005 VL 38 IS 1 BP 174 EP 181 DI 10.1021/ma048156x PG 8 WC Polymer Science SC Polymer Science GA 885QX UT WOS:000226173100025 ER PT J AU Conway, E Maddox, S Wild, V Peacock, JA Hawkins, E Norberg, P Madgwick, DS Baldry, IK Baugh, CM Hawthorn, JB Bridges, T Cannon, R Cole, S Colless, M Collins, C Couch, W Dalton, G De Propris, R Driver, SP Efstathiou, G Ellis, RS Frenk, CS Glazebrook, K Jackson, C Jones, B Lahav, O Lewis, I Lumsden, S Percival, W Peterson, BA Sutherland, W Taylor, K AF Conway, E Maddox, S Wild, V Peacock, JA Hawkins, E Norberg, P Madgwick, DS Baldry, IK Baugh, CM Hawthorn, JB Bridges, T Cannon, R Cole, S Colless, M Collins, C Couch, W Dalton, G De Propris, R Driver, SP Efstathiou, G Ellis, RS Frenk, CS Glazebrook, K Jackson, C Jones, B Lahav, O Lewis, I Lumsden, S Percival, W Peterson, BA Sutherland, W Taylor, K CA 2dFGRS Team TI The 2dF Galaxy Redshift Survey: the nature of the relative bias between galaxies of different spectral type SO MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY LA English DT Article DE surveys; galaxies : distances and redshifts; galaxies : statistics; large-scale structure of Universe ID LARGE-SCALE STRUCTURE; DENSITY; LUMINOSITY; MORPHOLOGY; UNIVERSE; COUNTS; STATISTICS; DEPENDENCE; EVOLUTION; MOMENTS AB We present an analysis of the relative bias between early- and late-type galaxies in the Two-degree Field Galaxy Redshift Survey(2dFGRS) - as defined by the parameter of Madgwick et al., which quantifies the spectral type of galaxies in the survey. We calculate counts in cells for flux-limited samples of early- and late-type galaxies, using approximately cubical cells with sides ranging from 7 to 42 h(-1) Mpc. We measure the variance of the counts in cells using the method of Efstathiou et al., which we find requires a correction for a finite volume effect equivalent to the integral constraint bias of the autocorrelation function. Using a maximum-likelihood technique we fit lognormal models to the one-point density distribution, and develop methods of dealing with biases in the recovered variances resulting from this technique. We then examine the joint density distribution function, f (delta(E), delta(L)), and directly fit deterministic bias models to the joint counts in cells. We measure a linear relative bias of approximate to1.3, which does not vary significantly with.Adeterministic linear bias model is, however, a poor approximation to the data, especially on small scales (l less than or equal to 28 h(-1) Mpc) where deterministic linear bias is excluded at high significance. A power-law bias model with index b(1) approximate to 0.75 is a significantly better fit to the data on all scales, although linear bias becomes consistent with the data for l greater than or similar to 40 h(-1) Mpc. C1 Univ Nottingham, Sch Phys & Astron, Nottingham NG7 2RD, England. Univ Durham, Dept Phys, Durham DH1 3LE, England. Univ Cambridge, Inst Astron, Cambridge CB3 0HA, England. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. ETH Honggerberg, Inst Astron, CH-8093 Zurich, Switzerland. Univ Edinburgh, Royal Observ, Inst Astron, Edinburgh EH9 3HJ, Midlothian, Scotland. Johns Hopkins Univ, Dept Phys & Astron, Baltimore, MD 21218 USA. Anglo Australian Observ, Epping, NSW 2121, Australia. Australian Natl Univ, Res Sch Astron & Astrophys, Weston, ACT 2611, Australia. Liverpool John Moores Univ, Astrophys Res Inst, Birkenhead L14 1LD, Merseyside, England. Univ New S Wales, Dept Astrophys, Sydney, NSW 2052, Australia. Univ Oxford, Dept Phys, Oxford OX1 3RH, England. Rutherford Appleton Lab, Space Sci & Technol Div, Didcot OX11 0QX, Oxon, England. CALTECH, Dept Astron, Pasadena, CA 91125 USA. Univ Leeds, Dept Phys, Leeds LS2 9JT, W Yorkshire, England. UCL, Dept Phys & Astron, London WC1E 6BT, England. Univ Bristol, Dept Phys, Astrophys Grp, Bristol BS8 1TL, Avon, England. RP Conway, E (reprint author), Univ Nottingham, Sch Phys & Astron, Nottingham NG7 2RD, England. EM edward.conway@astro.nottingham.ac.uk; steve.maddox@nottingham.ac.uk RI Baugh, Carlton/A-8482-2012; Jackson, Carole/K-1648-2013; Driver, Simon/H-9115-2014; Glazebrook, Karl/N-3488-2015; OI Hawkins, Ed/0000-0001-9477-3677; Baugh, Carlton/0000-0002-9935-9755; Jackson, Carole/0000-0002-7089-8827; Driver, Simon/0000-0001-9491-7327; Glazebrook, Karl/0000-0002-3254-9044; Maddox, Stephen/0000-0001-5549-195X; Jones, Bryn/0000-0002-4679-5625; Baldry, Ivan/0000-0003-0719-9385; Colless, Matthew/0000-0001-9552-8075 NR 63 TC 17 Z9 17 U1 0 U2 3 PU WILEY-BLACKWELL PI MALDEN PA COMMERCE PLACE, 350 MAIN ST, MALDEN 02148, MA USA SN 0035-8711 J9 MON NOT R ASTRON SOC JI Mon. Not. Roy. Astron. Soc. PD JAN 11 PY 2005 VL 356 IS 2 BP 456 EP 474 DI 10.1111/j.1365-2966.2004.08446.x PG 19 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 882OW UT WOS:000225949200004 ER PT J AU Zelenski, A Bravar, A Graham, D Haeberli, W Kokhanovski, S Makdisi, Y Mahler, G Nass, A Ritter, J Wise, T Zubets, V AF Zelenski, A Bravar, A Graham, D Haeberli, W Kokhanovski, S Makdisi, Y Mahler, G Nass, A Ritter, J Wise, T Zubets, V TI Absolute polarized H-jet polarimeter development, for RHIC SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 10th Workshop on Polarized Sources and Targets CY SEP 22-26, 2003 CL Russian Acad Sci, Budker Inst Nucl Phys, Siberian Branch, Novosibirsk, RUSSIA SP Int Comm High Energy Spin Phys, Int Sci & Technol Ctr, Russian Fdn Basic Res HO Russian Acad Sci, Budker Inst Nucl Phys, Siberian Branch DE polarized atomic beam source; intensity of the beam ID HYDROGEN; TARGET AB Status of the H-jet polarimeter development is reviewed. The preliminary results of atomic beam intensity and density measurements are presented. (C) 2004 Elsevier B.V. All rights reserved. C1 Brookhaven Natl Lab, Upton, NY 11973 USA. Univ Wisconsin, Madison, WI 53706 USA. INR, Moscow, Russia. RP Zelenski, A (reprint author), Brookhaven Natl Lab, Upton, NY 11973 USA. EM zelenski@bnl.gov NR 8 TC 35 Z9 35 U1 0 U2 4 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD JAN 11 PY 2005 VL 536 IS 3 BP 248 EP 254 DI 10.1016/j.nima.2004.08.080 PG 7 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 886XZ UT WOS:000226267700004 ER PT J AU Clendenin, JE Brachmann, A Garwin, EL Harvey, S Jiang, J Kirby, RE Luh, DA Maruyama, T Prepost, R Prescott, CY Turner, JL AF Clendenin, JE Brachmann, A Garwin, EL Harvey, S Jiang, J Kirby, RE Luh, DA Maruyama, T Prepost, R Prescott, CY Turner, JL TI Recent progress at SLAC extracting high charge from highly polarized photocathodes for future-collider applications SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 10th Workshop on Polarized Sources and Targets CY SEP 22-26, 2003 CL Russian Acad Sci, Budker Inst Nucl Phys, Siberian Branch, Novosibirsk, RUSSIA SP Int Comm High Energy Spin Phys, Int Sci & Technol Ctr, Russian Fdn Basic Res HO Russian Acad Sci, Budker Inst Nucl Phys, Siberian Branch DE photocathodes; photoemission; semiconductors; surface charge limit AB Future colliders such as NLC and JLC will require a highly polarized macropulse with charge that is more than an order of magnitude beyond that which could be produced for the SLC. The maximum charge from the SLC uniformly doped GaAs photocathode was limited by the surface charge limit (SCL). The SCL effect can be overcome by using an extremely high (greater than or equal to 10(19) cm(-3)) surface dopant concentration. When combined with a medium dopant concentration in the majority of the active layer (to avoid depolarization), the surface concentration has been found to degrade during normal heat cleaning (1 h at 600degreesC). The Be dopant as typically used in an MBE-grown superlattice cathode is especially susceptible to this effect compared to Zn or C dopant. Some relief can be found by lowering the cleaning temperature, but the long-term general solution appears to be atomic hydrogen cleaning. (C) 2004 Elsevier B.V. All rights reserved. C1 Stanford Linear Accelerator Ctr, Menlo Pk, CA 94025 USA. Univ Wisconsin, Dept Phys, Madison, WI 53706 USA. RP Clendenin, JE (reprint author), Stanford Linear Accelerator Ctr, 2575 Sand Hill Rd,Menlo Pk, Menlo Pk, CA 94025 USA. EM clen@slac.stanford.edu RI LUH, DAH-AN/B-3921-2008; Schaff, William/B-5839-2009 NR 9 TC 7 Z9 7 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD JAN 11 PY 2005 VL 536 IS 3 BP 308 EP 311 DI 10.1016/j.nima.2004.08.089 PG 4 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 886XZ UT WOS:000226267700014 ER PT J AU Otboeva, AV Shatunov, YM Ptitsyn, V AF Otboeva, AV Shatunov, YM Ptitsyn, V TI Self-polarizing electron ring for eRHIC project SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 10th Workshop on Polarized Sources and Targets CY SEP 22-26, 2003 CL Russian Acad Sci, Budker Inst Nucl Phys, Siberian Branch, Novosibirsk, RUSSIA SP Int Comm High Energy Spin Phys, Int Sci & Technol Ctr, Russian Fdn Basic Res HO Russian Acad Sci, Budker Inst Nucl Phys, Siberian Branch DE polarized beams; storage rings AB We present the electron storage ring for an arrangement of electron-proton and electron-ion collisions at RHIC. High degree of radiative electron polarization will be achieved at the beam energy range 5-10 GeV with characteristic time about 10 min. Required luminosity of polarized e-p collisions for studies of deep inelastic scattering is 1 X 10(33) cm(-2) s(-1) in the SCM energy range 15-100 GeV. (C) 2004 Elsevier B.V. All rights reserved. C1 Budker Inst Nucl Phys, Novosibirsk 630090, Russia. Brookhaven Natl Lab, Upton, NY 11973 USA. RP Shatunov, YM (reprint author), Budker Inst Nucl Phys, Novosibirsk 630090, Russia. EM Yu.M.Shatunov@inp.nsk.su NR 4 TC 0 Z9 0 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD JAN 11 PY 2005 VL 536 IS 3 BP 319 EP 322 DI 10.1016/j.nima.2004.08.091 PG 4 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 886XZ UT WOS:000226267700016 ER PT J AU Rong, Z Mohles, V Bacon, DJ Osetsky, YN AF Rong, Z Mohles, V Bacon, DJ Osetsky, YN TI Dislocation dynamics modelling of dislocation-loop interactions in irradiated metals SO PHILOSOPHICAL MAGAZINE LA English DT Article; Proceedings Paper CT Symposium on Defects and Deformation of Crystalline Solids CY MAR 02-06, 2003 CL San Diego, CA SP USAF Off Sci Res, Oak Ridge Natl Lab ID INTERSTITIAL CLUSTERS; COMPUTER-SIMULATION; DEFECT CLUSTERS; STRESS; FCC; DEFORMATION; MECHANISMS; MOBILITY; BCC AB The resistance dislocation loops provide to the glide of dislocations is an important element of several features of plasticity of irradiated metals. In the present work, a dislocation dynamics model based on the elasticity treatment of dislocations, with self-stress effects included. has been used to investigate the critical applied stress required for a gliding dislocation to overcome the stress field of a row of sessile loops near the glide plane. The critical stress has been determined for wide ranges of loop size, spacing and distance front the glide plane. Various approximations to the loop distribution have been tested. including an edge dipole, a single dislocation and a row of infinitesimal loops. The infinitesimal loop model, in particular, is shown to give good agreement with the accurate simulation data over a wide range of loop size and spacing. The ranges of applicability are discussed and compared with previous treatments in which such approximations have been used to investigate hardening due to dislocation-loop interactions. C1 Univ Liverpool, Dept Engn, Liverpool L69 3GH, Merseyside, England. Rhein Westfal TH Aachen, Inst Metallkunde & Metallphys, D-52056 Aachen, Germany. Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Bacon, DJ (reprint author), Univ Liverpool, Dept Engn, Brownlow Hill, Liverpool L69 3GH, Merseyside, England. EM djbacon@liv.ac.uk OI Osetskiy, Yury/0000-0002-8109-0030 NR 17 TC 12 Z9 12 U1 0 U2 9 PU TAYLOR & FRANCIS LTD PI ABINGDON PA 4 PARK SQUARE, MILTON PARK, ABINGDON OX14 4RN, OXON, ENGLAND SN 1478-6435 J9 PHILOS MAG JI Philos. Mag. PD JAN 11 PY 2005 VL 85 IS 2-3 SI SI BP 171 EP 188 DI 10.1080/14786430412331315644 PG 18 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering; Physics, Applied; Physics, Condensed Matter SC Materials Science; Metallurgy & Metallurgical Engineering; Physics GA 892ZY UT WOS:000226689700005 ER PT J AU Morris, JR Ye, YY Yoo, MH AF Morris, JR Ye, YY Yoo, MH TI First-principles examination of the (1012) twin boundary in hcp metals SO PHILOSOPHICAL MAGAZINE LA English DT Article; Proceedings Paper CT Symposium on Defects and Deformation of Crystalline Solids CY MAR 02-06, 2003 CL San Diego, CA SP USAF Off Sci Res, Oak Ridge Natl Lab ID RESOLUTION ELECTRON-MICROSCOPY; CLOSE-PACKED METALS; COMPUTER-SIMULATION; DISLOCATIONS; DEFECTS; 10(1)OVER-BAR-2; ZIRCONIUM; MOBILITY; ZINC; INTERFACES AB We have performed total-energy electronic structure calculations to examine competing structures for the (1012) twin boundary, which can form under tensile stress along the c axis. The twin boundary structures are significantly different. most notably in their symmetry. These calculations show that, for all materials studied, the different structures have nearly the same energy, in agreement with calculations from empirical potentials. This result is surprising given the difference in the structures. and the fact that previous first-principles calculations of the enemies of compression twin boundaries have shown significant differences from empirical potentials. C1 US DOE, Ames Lab, Ames, IA 50011 USA. Wuhan Univ, Ctr Anal & Testing, Wuhan 430072, Peoples R China. Korea Adv Inst Sci & Technol, Dept Mat Sci & Engn, Taejon 305701, South Korea. RP Morris, JR (reprint author), Oak Ridge Natl Lab, Met & Ceram Div, POB 2008, Oak Ridge, TN 37831 USA. EM morrisj@ornl.gov RI Morris, J/I-4452-2012 OI Morris, J/0000-0002-8464-9047 NR 24 TC 11 Z9 12 U1 4 U2 17 PU TAYLOR & FRANCIS LTD PI ABINGDON PA 4 PARK SQUARE, MILTON PARK, ABINGDON OX14 4RN, OXON, ENGLAND SN 1478-6435 EI 1478-6443 J9 PHILOS MAG JI Philos. Mag. PD JAN 11 PY 2005 VL 85 IS 2-3 SI SI BP 233 EP 238 DI 10.1080/14786430412331315671 PG 6 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering; Physics, Applied; Physics, Condensed Matter SC Materials Science; Metallurgy & Metallurgical Engineering; Physics GA 892ZY UT WOS:000226689700008 ER PT J AU Minor, AM Lilleodden, ET Jin, M Stach, EA Chrzan, DC Morris, JW AF Minor, AM Lilleodden, ET Jin, M Stach, EA Chrzan, DC Morris, JW TI Room temperature dislocation plasticity in silicon SO PHILOSOPHICAL MAGAZINE LA English DT Article; Proceedings Paper CT Symposium on Defects and Deformation of Crystalline Solids CY MAR 02-06, 2003 CL San Diego, CA SP USAF Off Sci Res, Oak Ridge Natl Lab ID TRANSMISSION ELECTRON-MICROSCOPY; PHASE-TRANSFORMATIONS; INDENTATION; NANOINDENTATION; DEFORMATION; AMORPHIZATION; SIMULATION; GERMANIUM; CRYSTALS; BEHAVIOR AB We present direct observations of room temperature dislocation plasticity in single crystalline silicon. Previous studies have shown that phase transformation and fracture are the relevant mechanisms of deformation in silicon. In contrast, using in-situ nanoindentation in a transmission electron microscope we find dislocation nucleation and metal-like flow. The results of finite-element modelling suggest that the presence of free surfaces in our unique sample geometry leads to preferential surface nucleation of dislocations and the suppression of phase transformation. C1 Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Mat Sci & Engn, Berkeley, CA 94720 USA. Lawrence Berkeley Lab, Natl Ctr Electron Microscopy, Berkeley, CA 94720 USA. RP Minor, AM (reprint author), Lawrence Berkeley Lab, Div Mat Sci, 1 Cyclotron Rd,MS 66, Berkeley, CA 94720 USA. EM aminor@lbl.gov RI Stach, Eric/D-8545-2011 OI Stach, Eric/0000-0002-3366-2153 NR 29 TC 75 Z9 76 U1 4 U2 28 PU TAYLOR & FRANCIS LTD PI ABINGDON PA 4 PARK SQUARE, MILTON PARK, ABINGDON OX14 4RN, OXON, ENGLAND SN 1478-6435 J9 PHILOS MAG JI Philos. Mag. PD JAN 11 PY 2005 VL 85 IS 2-3 SI SI BP 323 EP 330 DI 10.1080/14786430412331315680 PG 8 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering; Physics, Applied; Physics, Condensed Matter SC Materials Science; Metallurgy & Metallurgical Engineering; Physics GA 892ZY UT WOS:000226689700013 ER PT J AU Illman, WA Tartakovsky, DM AF Illman, WA Tartakovsky, DM TI Asymptotic analysis of three-dimensional pressure interference tests: A point source solution SO WATER RESOURCES RESEARCH LA English DT Article ID UNSATURATED FRACTURED TUFF; PNEUMATIC INJECTION TESTS; CROSS-HOLE TESTS; HYDRAULIC CONDUCTIVITY; CURVE INTERPRETATION; NUMERICAL INVERSION; METHODOLOGY; BOREHOLE; SCALE; ROCKS AB [1] Well test analyses conducted in steady state and transient flow regimes have complementary strengths and drawbacks. While steady state analyses are easy to interpret, they are useful only on a late-time portion of the data collected during pressure interference tests and do not provide estimates of porosity. Transient type curve and numerical inverse approaches overcome these shortcomings but are harder to analyze, and their reliability can be affected by changing external forcings. We develop a new approach to estimate permeability and porosity from well tests, which is based on an asymptotic analysis of pressure transients during three-dimensional pressure interference tests. Our approach results in a straight line data fitting, rendering the data interpretation straightforward. It also allows one to use intermediate-to-late time pressure data. To illustrate the advantages of the proposed technique, we use it to analyze data from several cross-hole pneumatic injection tests conducted in unsaturated fractured tuff. We demonstrate that the equivalent permeabilities and porosities obtained from our analysis compare well with their counterparts inferred from more complicated approaches, such as type curve and numerical inverse analyses as well as from a steady state analysis. C1 Univ Iowa, Dept Geosci, Iowa City, IA 52242 USA. Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. Univ Iowa, Dept Civil & Environm Engn, Iowa City, IA 52242 USA. Univ Iowa, IIHR Hydrosci & Engn, Iowa City, IA 52242 USA. RP Illman, WA (reprint author), Univ Iowa, Dept Geosci, Iowa City, IA 52242 USA. EM walter-illman@uiowa.edu; dmt@lan1.gov RI Tartakovsky, Daniel/E-7694-2013 NR 16 TC 12 Z9 12 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0043-1397 J9 WATER RESOUR RES JI Water Resour. Res. PD JAN 11 PY 2005 VL 41 IS 1 AR W01002 DI 10.1029/2004WR003431 PG 7 WC Environmental Sciences; Limnology; Water Resources SC Environmental Sciences & Ecology; Marine & Freshwater Biology; Water Resources GA 890ZA UT WOS:000226549300002 ER PT J AU Naulleau, PP AF Naulleau, PP TI Effect of mask-roughness on printed contact-size variation in extreme-ultraviolet lithography SO APPLIED OPTICS LA English DT Article ID SIMULATION; SCATTERING; MODEL AB Relying on reflective mask technology, extreme-ultraviolet (EUV) lithography is particularly vulnerable to mask substrate roughness. Previous research has shown mask roughness to play a significant role in printed line-edge roughness (LER). Here the analysis of mask-roughness effects is extended to printed contact-size variations. Unlike LER, illumination partial coherence is found to have little affect on the results for contacts that are near the diffraction limit. Analysis shows that, given the current state-of-the-art EUV mask, mask roughness has a significant effect on the process window for small contacts. The analysis also shows that a significant portion of the contact-size variation observed in recent 0.1-numerical-aperture EUV exposures can be attributed to the mask-roughness effect studied here. 0 2005 Optical Society of America. C1 Lawrence Berkeley Lab, Ctr Xray Opt, Berkeley, CA 94720 USA. RP Lawrence Berkeley Lab, Ctr Xray Opt, 1 Cyclotron Rd, Berkeley, CA 94720 USA. EM pnaulleau@lbl.gov NR 24 TC 7 Z9 7 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 JAN 10 PY 2005 VL 44 IS 2 BP 183 EP 189 DI 10.1364/AO.44.000183 PG 7 WC Optics SC Optics GA 887QJ UT WOS:000226320300003 PM 15678769 ER PT J AU Gai, Z Howe, JY Guo, JD Blom, DA Plummer, EW Shen, J AF Gai, Z Howe, JY Guo, JD Blom, DA Plummer, EW Shen, J TI Self-assembled FePt nanodot arrays with mono-dispersion and -orientation SO APPLIED PHYSICS LETTERS LA English DT Article AB For self-assembled nanodots, the ultimate dream is to simultaneously achieve tunable uniformity in size, spatial distribution, chemical composition, and crystallographic orientation. By utilizing the Volmer-Weber growth mode in thin film epitaxy, we have grown self-assembled two-dimensional arrays of FePt alloy nanodots that are uniform in size, chemical composition, and are all crystallgraphically aligned. These dot assemblies are ferromagnetic at room temperature and can be easily transferred onto other templates without destroying the size and orientation uniformity. (C) 2005 American Institute of Physics. C1 Oak Ridge Natl Lab, Condensed Matter Sci Div, Oak Ridge, TN 37831 USA. Peking Univ, State Key Lab Mesoscop Phys, Dept Phys, Beijing 100871, Peoples R China. Oak Ridge Natl Lab, Div Met & Ceram, Oak Ridge, TN 37831 USA. Univ Tennessee, Dept Phys & Astron, Knoxville, TN 37996 USA. RP Gai, Z (reprint author), Oak Ridge Natl Lab, Condensed Matter Sci Div, Oak Ridge, TN 37831 USA. EM shenj@ornl.gov RI Gai, Zheng/B-5327-2012; Howe, Jane/G-2890-2011; Guo, Jiandong/F-2081-2015 OI Gai, Zheng/0000-0002-6099-4559; Guo, Jiandong/0000-0002-7893-022X NR 7 TC 26 Z9 29 U1 0 U2 5 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 JAN 10 PY 2005 VL 86 IS 2 AR 023107 DI 10.1063/1.1849849 PG 3 WC Physics, Applied SC Physics GA 893EG UT WOS:000226701500069 ER PT J AU Han, SH Hasoon, FS Al-Thani, HA Hermann, AM Levi, DH AF Han, SH Hasoon, FS Al-Thani, HA Hermann, AM Levi, DH TI Effect of Cu deficiency on the defect levels of Cu0.86In1.09Se2.05 determined by spectroscopic ellipsometry SO APPLIED PHYSICS LETTERS LA English DT Article ID THIN-FILMS; CUINSE2; SURFACE; DIFFERENTIATION; CULNSE2 AB Room temperature spectroscopic ellipsometry measurement of Cu0.86In1.09Se2.05 reveals that shallow defect states are found in the sub-band-gap region. The energies of these defect levels are in quantitative agreement with those calculated and measured by photoluminescence, electrical conductivity, optical absorption, and deep level transient spectroscopy at low temperatures. The results can be explained in terms of the defect physics of this material and suggest that the defect levels are due to Cu deficiency. This work opens up the possibility of measuring defect levels of off-stoichiometric or heavily doped semiconductors by spectroscopic ellipsometry at room temperature. (C) 2005 American Institute of Physics. C1 Natl Renewable Energy Lab, Golden, CO 80401 USA. Univ Colorado, Dept Phys, Boulder, CO 80309 USA. RP Han, SH (reprint author), Natl Renewable Energy Lab, 1617 Cole Blvd, Golden, CO 80401 USA. EM dean_levi@nrel.gov RI Han, Sung-Ho/B-7678-2008 NR 24 TC 7 Z9 7 U1 0 U2 3 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD JAN 10 PY 2005 VL 86 IS 2 AR 021903 DI 10.1063/1.1849840 PG 3 WC Physics, Applied SC Physics GA 893EG UT WOS:000226701500021 ER PT J AU Losurdo, M Capezzuto, P Bruno, G Brown, A Kim, TH Yi, CY Zakharov, DN Liliental-Weber, Z AF Losurdo, M Capezzuto, P Bruno, G Brown, A Kim, TH Yi, CY Zakharov, DN Liliental-Weber, Z TI Interfacial reactions during GaN and AiN epitaxy on 4H- and 6H-SiC(0001) SO APPLIED PHYSICS LETTERS LA English DT Article ID MOLECULAR-BEAM EPITAXY; SURFACE; GROWTH; TEMPERATURE; SUBSTRATE AB Thin layers of AlN and GaN have been grown by plasma-assisted molecular beam epitaxy on Si-face 4H- and 6H-SiC(0001)(Si) substrates. The impact of the SiC surface preparation and oxide removal via a Ga deposition and desorption process on the chemistry and structure of the GaN/SiC and AlN/SiC interfaces, and on the GaN/SiC subsurface reactivity is characterized. We also investigate the impact of this process on growth mode evolution. (C) 2005 American Institute of Physics. C1 CNR, IMIP, Inst Inorgan Methodol & Plasmas, I-70126 Bari, Italy. INSTM, I-70126 Bari, Italy. Duke Univ, Dept Elect & Comp Engn, Durham, NC 27709 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Losurdo, M (reprint author), CNR, IMIP, Inst Inorgan Methodol & Plasmas, Via Orabona 4, I-70126 Bari, Italy. EM cscpml18@area.ba.cnr.it RI Liliental-Weber, Zuzanna/H-8006-2012; Zakharov, Dmitri/F-4493-2014; OI LOSURDO, MARIA/0000-0002-8008-5192 NR 11 TC 11 Z9 11 U1 0 U2 8 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 JAN 10 PY 2005 VL 86 IS 2 AR 021920 DI 10.1063/1.1852703 PG 3 WC Physics, Applied SC Physics GA 893EG UT WOS:000226701500038 ER PT J AU Krumholz, MR McKee, CF Klein, RI AF Krumholz, MR McKee, CF Klein, RI TI Bondi accretion in the presence of vorticity SO ASTROPHYSICAL JOURNAL LA English DT Article DE accretion, accretion disks; black hole physics; hydrodynamics; stars : formation; stars : neutron ID ADAPTIVE MESH REFINEMENT; GAUSSIAN CLOUD CONDITIONS; STELLAR CLUSTERS; BLACK-HOLES; NUMERICAL SIMULATIONS; INTERSTELLAR MATTER; HOYLE ACCRETION; NEUTRON-STARS; FRAGMENTATION; HYDRODYNAMICS AB The classical Bondi-Hoyle formula gives the accretion rate onto a point particle of a gas with a uniform density and velocity. However, the Bondi-Hoyle problem considers only gas with no net vorticity, while in a real astrophysical situation accreting gas invariably has at least a small amount of vorticity. We therefore consider the related case of accretion of gas with constant vorticity, for the cases of both small and large vorticity. We confirm the findings of earlier two-dimensional simulations that even a small amount of vorticity can substantially change both the accretion rate and the morphology of the gas flow lines. We show that in three dimensions the resulting flow field is nonaxisymmetric and time-dependent. The reduction in accretion rate is due to an accumulation of circulation near the accreting particle. Using a combination of simulations and analytic treatment, we provide an approximate formula for the accretion rate of gas onto a point particle as a function of the vorticity of the surrounding gas. C1 Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Phys & Astron, Berkeley, CA 94720 USA. Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Krumholz, MR (reprint author), Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. EM krumholz@astron.berkeley.edu; cmckee@astron.berkeley.edu; klein@astron.berkeley.edu OI Krumholz, Mark/0000-0003-3893-854X NR 36 TC 45 Z9 45 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 JAN 10 PY 2005 VL 618 IS 2 BP 757 EP 768 DI 10.1086/426051 PN 1 PG 12 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 887GM UT WOS:000226293800019 ER PT J AU Chen, H Beiersdorfer, P Scofield, JH Brown, GV Boyce, KR Kelley, RL Kilbourne, CA Porter, FS Gu, MF Kahn, SM AF Chen, H Beiersdorfer, P Scofield, JH Brown, GV Boyce, KR Kelley, RL Kilbourne, CA Porter, FS Gu, MF Kahn, SM TI Excitation cross section measurement for n=3 to n=2 line emission in Fe20+ to Fe23+ SO ASTROPHYSICAL JOURNAL LA English DT Article DE atomic data; atomic processes; methods : laboratory; X-rays : general ID X-RAY SPECTROMETER; BEAM ION-TRAP; LABORATORY MEASUREMENTS; ELECTRON-BEAM; FE-XVII; RADIATIVE RECOMBINATION; RELATIVE INTENSITY; XMM-NEWTON; TRANSITIONS; POLARIZATION AB Electron impact excitation cross sections have been measured for iron L-shell 3 --> 2 lines of Fe XXI to Fe XXIV at the EBIT-II electron beam ion trap using a crystal spectrometer and a 6x6 element array microcalorimeter. The cross sections were determined by direct normalization to the well-established cross section of radiative electron capture, and a summary of calculated energy-dependent radiative recombination cross sections for electron capture into the n=2 state fine-structure levels of Fe16+ to Fe23+ ions is given. The measurement results for 17 lines and their comparison with model calculations are presented. While agreement of the model calculations with the experiment is good for most measured lines, significant discrepancies were found for a few lines, including the strongest line in Fe XXI. C1 Lawrence Livermore Natl Lab, High Temp & Astrophys Div, Livermore, CA 94551 USA. Johns Hopkins Univ, Dept Phys & Astron, Baltimore, MD 21218 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Stanford Univ, Dept Phys, Stanford, CA 94305 USA. RP Chen, H (reprint author), Lawrence Livermore Natl Lab, High Temp & Astrophys Div, 7000 East Ave, Livermore, CA 94551 USA. RI Porter, Frederick/D-3501-2012; Kelley, Richard/K-4474-2012 OI Porter, Frederick/0000-0002-6374-1119; NR 40 TC 14 Z9 14 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 JAN 10 PY 2005 VL 618 IS 2 BP 1086 EP 1094 DI 10.1086/426135 PN 1 PG 9 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 887GM UT WOS:000226293800052 ER PT J AU Kenny, PA Enver, T Ashworth, A AF Kenny, PA Enver, T Ashworth, A TI Receptor and secreted targets of Wnt-I/beta-catenin signalling in mouse mammary epithelial cells SO BMC CANCER LA English DT Article ID MOTILITY-STIMULATING PROTEIN; GREEN FLUORESCENT PROTEIN; BETA-CATENIN; GENE-EXPRESSION; LYSOPHOSPHOLIPASE-D; AUTOCRINE GROWTH; COLON-CARCINOMA; CYCLIN D1; PATHWAY; IDENTIFICATION AB Background: Deregulation of the Wnt/ beta-catenin signal transduction pathway has been implicated in the pathogenesis of tumours in the mammary gland, colon and other tissues. Mutations in components of this pathway result in beta-catenin stabilization and accumulation, and the aberrant modulation of beta-catenin/TCF target genes. Such alterations in the cellular transcriptional profile are believed to underlie the pathogenesis of these cancers. We have sought to identify novel target genes of this pathway in mouse mammary epithelial cells. Methods: Gene expression microarray analysis of mouse mammary epithelial cells inducibly expressing a constitutively active mutant of beta-catenin was used to identify target genes of this pathway. Results: The differential expression in response to DeltaNbeta-catenin for five putative target genes, Autotaxin, Extracellular Matrix Protein 1 (Ecm1), CD14, Hypoxia-inducible gene 2 (Hig2) and Receptor Activity Modifying Protein 3 (RAMP3), was independently validated by northern blotting. Each of these genes encodes either a receptor or a secreted protein, modulation of which may underlie the interactions between Wnt/beta-catenin tumour cells and between the tumour and its microenvironment. One of these genes, Hig2, previously shown to be induced by both hypoxia and glucose deprivation in human cervical carcinoma cells, was strongly repressed upon DeltaNbeta-catenin induction. The predicted N-terminus of Hig2 contains a putative signal peptide suggesting it might be secreted. Consistent with this, a Hig2-EGFP fusion protein was able to enter the secretory pathway and was detected in conditioned medium. Mutation of critical residues in the putative signal sequence abolished its secretion. The expression of human HIG2 was examined in a panel of human tumours and was found to be significantly downregulated in kidney tumours compared to normal adjacent tissue. Conclusions: HIG2 represents a novel non-cell autonomous target of the Wnt pathway which is potentially involved in human cancer. C1 Inst Canc Res, Breakthrough Breast Canc Res Ctr, London SW3 6JB, England. Inst Canc Res, Sect Gene Funct & Regulat, London SW3 6JB, England. RP Univ Calif Berkeley, Lawrence Berkeley Lab, Div Life Sci, Berkeley, CA 94720 USA. EM pakenny@lbl.gov; tenver@gwmail.jr2.ox.ac.uk; alana@icr.ac.uk RI Kenny, Paraic/A-3120-2008 NR 58 TC 37 Z9 38 U1 0 U2 4 PU BIOMED CENTRAL LTD PI LONDON PA 236 GRAYS INN RD, FLOOR 6, LONDON WC1X 8HL, ENGLAND SN 1471-2407 J9 BMC CANCER JI BMC Cancer PD JAN 10 PY 2005 VL 5 AR 3 DI 10.1186/1471-2407-5-3 PG 9 WC Oncology SC Oncology GA 891XS UT WOS:000226614900001 PM 15642117 ER PT J AU Balakin, AA Fraiman, GM Fisch, NJ AF Balakin, AA Fraiman, GM Fisch, NJ TI Hot electron production in plasmas illuminated by intense lasers SO JETP LETTERS LA English DT Article ID BEAMS AB Electron-ion collisions in strong electromagnetic fields, whether nonrelativistic or ultrarelativistic, can lead to the acceleration of electrons to high energies. The production efficiency and the Joule heating rate are calculated. Experimental verification of theoretical predictions, including the power law scaling, is presented. (c) 2005 Pleiades Publishing, Inc. C1 Russian Acad Sci, Inst Appl Phys, Nizhnii Novgorod 603950, Russia. Princeton Plasma Phys Lab, Princeton, NJ 08543 USA. RP Balakin, AA (reprint author), Russian Acad Sci, Inst Appl Phys, Nizhnii Novgorod 603950, Russia. RI Balakin, Alexey/Q-9326-2016 OI Balakin, Alexey/0000-0001-6252-7279 NR 10 TC 4 Z9 4 U1 0 U2 2 PU MAIK NAUKA/INTERPERIODICA/SPRINGER PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013-1578 USA SN 0021-3640 J9 JETP LETT+ JI Jetp Lett. PD JAN 10 PY 2005 VL 81 IS 1 BP 1 EP 5 DI 10.1134/1.1881725 PG 5 WC Physics, Multidisciplinary SC Physics GA 908JV UT WOS:000227784200001 ER PT J AU Wheatley, V Pullin, DI Samtaney, R AF Wheatley, V Pullin, DI Samtaney, R TI Regular shock refraction at an oblique planar density interface in magnetohydrodynamics SO JOURNAL OF FLUID MECHANICS LA English DT Article ID MHD INTERMEDIATE SHOCKS; IDEAL MAGNETOHYDRODYNAMICS; RIEMANN PROBLEMS; MAGNETIC-FIELD; WAVES; RECONNECTION; STABILITY; MODEL AB We consider the problem of regular refraction (where regular implies all waves meet at a single point) of a shock at an oblique planar contact discontinuity separating conducting fluids of different densities in the presence of a magnetic field aligned with the incident shock velocity. Planar ideal magnetohydrodynamic (MHD) simulations indicate that the presence of a magnetic field inhibits the deposition of vorticity on the shocked contact. We show that the shock refraction process produces a system of five to seven plane waves that may include fast, intermediate, and slow MHD shocks, slow compound waves, 180degrees rotational discontinuities, and slow-mode expansion fans that intersect at a point. In all solutions, the shocked contact is vorticity free and hence stable. These solutions are not unique, but differ in the types of waves that participate. The set of equations governing the structure of these multiple-wave solutions is obtained in which fluid property variation is allowed only in the azimuthal direction about the wave-intersection point. Corresponding solutions are referred to as either quintuple-points, sextuple-points, or septuple-points, depending on the number of participating waves. A numerical method of solution is described and examples are compared to the results of numerical simulations for moderate magnetic field strengths. The limit of vanishing magnetic field at fixed permeability and pressure is studied for two solution types. The relevant solutions correspond to the hydrodynamic triple-point with the shocked contact replaced by a singular structure consisting of a wedge, whose angle scales with the applied field magnitude, bounded by either two slow compound waves or two 180degrees rotational discontinuities, each followed by a slow-mode expansion fan. These bracket the MHD contact which itself cannot support a tangential velocity jump in the presence of a non-parallel magnetic field. The magnetic field within the singular wedge is finite and the shock-induced change in tangential velocity across the wedge is supported by the expansion fans that form part of the compound waves or follow the rotational discontinuities. To verify these findings, an approximate leading-order asymptotic solution appropriate for both flow structures was computed. The full and asymptotic solutions are compared quantitatively. C1 CALTECH, Grad Aeronaut Labs, Pasadena, CA 91125 USA. Princeton Univ, Princeton Plasma Phys Lab, Princeton, NJ 08543 USA. RP Wheatley, V (reprint author), CALTECH, Grad Aeronaut Labs, Pasadena, CA 91125 USA. RI Wheatley, Vincent/D-9627-2013 OI Wheatley, Vincent/0000-0002-7287-7659 NR 18 TC 17 Z9 17 U1 0 U2 9 PU CAMBRIDGE UNIV PRESS PI NEW YORK PA 40 WEST 20TH ST, NEW YORK, NY 10011-4211 USA SN 0022-1120 J9 J FLUID MECH JI J. Fluid Mech. PD JAN 10 PY 2005 VL 522 BP 179 EP 214 DI 10.1017/S0022112004001880 PG 36 WC Mechanics; Physics, Fluids & Plasmas SC Mechanics; Physics GA 898KG UT WOS:000227075100008 ER PT J AU Kollet, SJ Zlotnik, VA AF Kollet, SJ Zlotnik, VA TI Influence of aquifer heterogeneity and return flow on pumping test data interpretation SO JOURNAL OF HYDROLOGY LA English DT Article DE unconfined aquifer; pumping test; heterogeneity; aquifer return flow; effective hydraulic parameters; analytical and numerical models ID DELAYED GRAVITY RESPONSE; UNCONFINED AQUIFERS; WATER-TABLE; HYDRAULIC CONDUCTIVITY; MODELS; YIELD; WELL; TRANSMISSIVITY; DEPLETION; DRAINAGE AB Analytical solutions of drawdown in unconfined aquifers are widely applied for determining the specific yield, S-y, and the horizontal and the vertical hydraulic conductivity K-r and K-z, respectively. In many previous studies, estimates of S-y and K-z were observed to be highly variable and physically unrealistic. This has been attributed to the conceptualization of flow above the declining water table and aquifer heterogeneity in the applied models. We present the analysis of time-drawdown data from a pumping test instrumented with depth-differentiated observation piezometers arranged in clusters. Applying homogeneous anisotropic aquifer models in combination with nonlinear least squares parameter identification techniques, the data were analyzed in different groups: analysis of data from individual piezometer clusters and simultaneous analysis of the entire data set from all piezometer clusters (global analysis). From the cluster analyses, estimates of S-y and K-z exhibit large variances and depart from a priori estimates inferred from the hydrostratigraphy. Parameter estimates from the global analysis do not fall within the parameter bounds (minimum and maximum values) defined by the cluster analyses. While heterogeneity appears to be the important reason for large parameter variances, we discuss the influence of rarely considered aquifer return flow on drawdown and the inconsistent results from the cluster and global analyses. We corroborate our findings with data on hydraulic gradients, slug test data, and results from the application of a more realistic numerical flow model. (C) 2004 Elsevier B.V. All rights reserved. C1 Univ Nebraska, Dept Geosci, Lincoln, NE 68588 USA. RP Kollet, SJ (reprint author), Lawrence Livermore Natl Lab, Div Environm Sci, 700 East Ave,L-206, Livermore, CA 94550 USA. EM kollet2@llnl.gov NR 53 TC 15 Z9 15 U1 2 U2 5 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-1694 J9 J HYDROL JI J. Hydrol. PD JAN 10 PY 2005 VL 300 IS 1-4 BP 267 EP 285 DI 10.1016/j.jhydrol.2004.06.011 PG 19 WC Engineering, Civil; Geosciences, Multidisciplinary; Water Resources SC Engineering; Geology; Water Resources GA 886JN UT WOS:000226223400018 ER PT J AU Liaw, BY Jungst, RG Nagasubramanian, G Case, HL Doughty, DH AF Liaw, BY Jungst, RG Nagasubramanian, G Case, HL Doughty, DH TI Modeling capacity fade in lithium-ion cells SO JOURNAL OF POWER SOURCES LA English DT Article DE lithium-ion battery; capacity fade; equivalent-circuit model simulation; battery life prediction; thermal aging ID BATTERY SIMULATION; FUEL-CELLS; POWER AB Battery life is an important, yet technically challenging, issue for battery development and application. Adequately estimating battery life requires a significant amount of testing and modeling effort to validate the results. Integrated battery testing and modeling is quite feasible today to simulate battery performance, and therefore applicable to predict its life. A relatively simple equivalent-circuit model (ECM) is used in this work to show that such an integrated approach can actually lead to a high-fidelity simulation of a lithium-ion cell's performance and life. The methodology to model the cell's capacity fade during thermal aging is described to illustrate its applicability to battery calendar life prediction. (C) 2004 Elsevier B.V. All rights reserved. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Liaw, BY (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. EM bliaw@hawaii.edu NR 22 TC 98 Z9 103 U1 3 U2 58 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0378-7753 J9 J POWER SOURCES JI J. Power Sources PD JAN 10 PY 2005 VL 140 IS 1 BP 157 EP 161 DI 10.1016/j.jpowsour.2004.08.017 PG 5 WC Chemistry, Physical; Electrochemistry; Energy & Fuels; Materials Science, Multidisciplinary SC Chemistry; Electrochemistry; Energy & Fuels; Materials Science GA 886XH UT WOS:000226265900020 ER PT J AU Mena, O AF Mena, O TI Unveiling neutrino mixing and leptonic CP violation SO MODERN PHYSICS LETTERS A LA English DT Review DE neutrino oscillations; CP violation; degeneracies ID OSCILLATION EXPERIMENTS; BETA-DECAY; PHYSICS; GOLDEN; BEAM; MASS AB We review the present understanding of neutrino masses and mixings, discussing what are the unknowns in the three-family oscillation scenario. Despite the anticipated success coming from the planned long baseline neutrino experiments in unraveling the leptonic mixing sector, there are two important unknowns which may remain obscure: the mixing angle theta(13) and the CP-phase delta. The measurement of these two parameters has led us to consider the combination of superbeams and neutrino factories as the key to unveil the neutrino oscillation picture. C1 Fermilab Natl Accelerator Lab, Batavia, IL 60510 USA. RP Fermilab Natl Accelerator Lab, POB 500, Batavia, IL 60510 USA. EM omena@fnal.gov NR 63 TC 20 Z9 20 U1 0 U2 0 PU WORLD SCIENTIFIC PUBL CO PTE LTD PI SINGAPORE PA 5 TOH TUCK LINK, SINGAPORE 596224, SINGAPORE SN 0217-7323 EI 1793-6632 J9 MOD PHYS LETT A JI Mod. Phys. Lett. A PD JAN 10 PY 2005 VL 20 IS 1 BP 1 EP 17 DI 10.1142/S0217732305016269 PG 17 WC Physics, Nuclear; Physics, Particles & Fields; Physics, Mathematical SC Physics GA 894BA UT WOS:000226763600001 ER PT J AU Beane, SR Bedaque, PF Parreno, A Savage, MJ AF Beane, SR Bedaque, PF Parreno, A Savage, MJ TI A framework for exploring the interactions and decays of hyperons with lattice QCD SO NUCLEAR PHYSICS A LA English DT Article ID CHIRAL PERTURBATION-THEORY; EFFECTIVE-FIELD THEORY; NUCLEON-NUCLEON INTERACTIONS; MESON-EXCHANGE MODEL; ELASTIC-SCATTERING; MATRIX-ELEMENTS; FINITE-VOLUME; BARYON OCTET; FORCES; POTENTIALS AB In this work we outline a program for lattice QCD that would greatly contribute to understanding the strong and weak interactions of strange baryons. The low-energy, effective field theory describing hyperon-nucleon scattering in QCD and partially-quenched QCD is constructed. This framework will allow lattice simulations of the low-energy scattering parameters to be extrapolated to the physical values of the quark masses. We explore the long-standing discrepancies in the P-wave amplitudes for non-leotonic hyperon decays using two-flavor chiral perturbation theory, and emphasize that the problem is not merely. an artifact of perturbing about the chiral limit of the three-flavour theory. As energy is not conserved in the lattice simulation of the Lambda --> N two-point function, we include the surface terms in, the effective field theory required to determine the underlying weak amplitude. (C) 2004 Published by Elsevier B.V. C1 Univ New Hampshire, Dept Phys, Durham, NH 03824 USA. Jefferson Lab, Newport News, VA 23606 USA. Lawrence Berkeley Lab, Berkeley, CA 94720 USA. Univ Barcelona, Fac Fis, Dept ECM, E-08028 Barcelona, Spain. Univ Washington, Dept Phys, Seattle, WA 98195 USA. RP Beane, SR (reprint author), Univ New Hampshire, Dept Phys, Durham, NH 03824 USA. EM silas@physics.unh.edu NR 65 TC 62 Z9 62 U1 1 U2 6 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 JAN 10 PY 2005 VL 747 IS 1 BP 55 EP 74 DI 10.1016/j.nuclphysa.2004.09.081 PG 20 WC Physics, Nuclear SC Physics GA 881CN UT WOS:000225841100004 ER PT J AU Juodagalvis, A Langanke, K Martinez-Pinedo, G Hix, WR Dean, DJ Sampaio, JM AF Juodagalvis, A Langanke, K Martinez-Pinedo, G Hix, WR Dean, DJ Sampaio, JM TI Neutral-current neutrino-nucleus cross sections for A similar to 50-65 nuclei SO NUCLEAR PHYSICS A LA English DT Article DE shell model; random-phase approximation; Gamow-Teller transitions; neutral current; weak interactions; neutrino-nucleus reaction cross section; nuclear astrophysics ID WEAK-INTERACTION RATES; INTERMEDIATE-MASS NUCLEI; SHELL-MODEL CALCULATIONS; STELLAR CORE COLLAPSE; SUPERNOVA ENVIRONMENT; RANGE A=45-65; DISTRIBUTIONS; EVOLUTION; STRENGTH; PHYSICS AB We study neutral-current neutrino-nucleus reaction cross sections for Mn, Fe, Co and Ni isotopes. An earlier study for a few selected nuclei has shown that in the supernova environment the cross sections are increased for low energy neutrinos due to finite-temperature effects. Our work supports this finding for a much larger set of nuclei. Furthermore we extend previous work to higher neutrino energies considering allowed and forbidden multipole contributions to the cross sections. The allowed contributions are derived from large-scale shell model calculations of the Gamow-Teller strength, while the other multipole contributions are calculated within the random phase approximation. We present the cross sections as functions of initial and final neutrino energies and for a range of supernova-relevant temperatures. These cross sections will allow improved estimates of inelastic neutrino reactions on nuclei in supenova simulations. (C) 2004-Elsevier B.V. All rights reserved. C1 Oak Ridge Natl Lab, Div Phys, Oak Ridge, TN 37831 USA. Univ Tennessee, Dept Phys & Astron, Knoxville, TN 37996 USA. Aarhus Univ, Inst Fys & Astron, DK-8000 Aarhus C, Denmark. Inst Estudis Espacials Catalunya, Edifici Nexus, E-08034 Barcelona, Spain. Inst Catalana Recerca & Estudis Avancats, E-08010 Barcelona, Spain. RP Oak Ridge Natl Lab, Div Phys, POB 2008, Oak Ridge, TN 37831 USA. EM andrius@mail.phy.ornl.gov RI Hix, William/E-7896-2011; Martinez-Pinedo, Gabriel/A-1915-2013; Sampaio, Jorge/M-4750-2013; OI Hix, William/0000-0002-9481-9126; Martinez-Pinedo, Gabriel/0000-0002-3825-0131; Sampaio, Jorge/0000-0003-4359-493X; Dean, David/0000-0002-5688-703X NR 38 TC 39 Z9 39 U1 1 U2 6 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 JAN 10 PY 2005 VL 747 IS 1 BP 87 EP 108 DI 10.1016/j.nuclphysa.2004.09.005 PG 22 WC Physics, Nuclear SC Physics GA 881CN UT WOS:000225841100006 ER PT J AU Gonzalez, J Liu, CY Yoo, J Mao, XL Russo, RE AF Gonzalez, J Liu, CY Yoo, J Mao, XL Russo, RE TI Double-pulse laser ablation inductively coupled plasma mass spectrometry SO SPECTROCHIMICA ACTA PART B-ATOMIC SPECTROSCOPY LA English DT Article DE double pulse; laser ablation; ICP-MS; particles; temporal relative standard deviation; precision ID PARTICLE-SIZE DISTRIBUTION; INDUCED BREAKDOWN SPECTROSCOPY; ELEMENTAL FRACTIONATION; SINGLE; SEPARATION; SAMPLES; SOLIDS AB This paper describes the use of double-pulse laser ablation to improve ICP-MS internal (temporal relative standard deviation, %TRSD) and external (%RSD) precision. The first laser pulse is used to ablate a large quantity of mass from the sample surface. The second pulse is applied with a variable time delay after the first pulse to break the ablated mass into a finer aerosol, which is more readily transported to and digested in the ICP-MS. A factor of two improvement in %TRSD and factor of five in %RSD are demonstrated. (C) 2004 Elsevier B.V. All rights reserved. C1 Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. RP Russo, RE (reprint author), Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. EM rerusso@lbl.gov NR 13 TC 27 Z9 28 U1 0 U2 6 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0584-8547 J9 SPECTROCHIM ACTA B JI Spectroc. Acta Pt. B-Atom. Spectr. PD JAN 10 PY 2005 VL 60 IS 1 BP 27 EP 31 DI 10.1016/j.sab.2004.10.009 PG 5 WC Spectroscopy SC Spectroscopy GA 892ZN UT WOS:000226688600003 ER PT J AU Potapenko, DV Horn, JM Beuhler, RJ Song, Z White, MG AF Potapenko, DV Horn, JM Beuhler, RJ Song, Z White, MG TI Reactivity studies with gold-supported molybdenum nanoparticles SO SURFACE SCIENCE LA English DT Article DE scanning tunneling microscopy; thermal desorption spectroscopy; chemical vapor deposition; surface structure, morphology, roughness and topography; molybdenum; sulfides; clusters ID SCANNING-TUNNELING-MICROSCOPY; EPITAXIAL-GROWTH; ULTRAHIGH-VACUUM; SURFACE ALLOYS; AU(111); METAL; ADSORPTION; MO(110); MO(CO)(6); CHEMISTRY AB The reconstructed (22 x root3)-Au(111) surface was used as a template and inert support for depositing Mo nanoparticles for reactivity studies of desulfurization and the formation of MoSx nanoparticles. Nanoparticles of Mo were prepared on the Au(111) substrate by two methods: physical vapor deposition (PVD) of Mo and UV-assisted chemical vapor deposition (UV-CVD) through a molybdenum hexacarbonyl precursor. STM studies have shown that the Mo nanoparticles are thermodynamically unstable on the Au(111) surface, and that gold encapsulates Mo at temperatures above 300K. Reactivity studies using Auger electron spectroscopy (AES) and temperature programmed desorption (TPD) show that bare Mo nanoparticles are very reactive and can cause complete dissociation of hydrogen sulfide, methyl mercaptan, and thiophene. The presence of gold atoms on the Mo nanoparticles modifies their reactivity. In the case of H2S and CH3SH, the overall activity for desufurization is unaffected by gold encapsulation; however, the selectivity to form methane from CH3SH increased from 20% on bare Mo particles to 60% on gold-covered Mo particles. In contrast, gold-encapsulated Mo nanoparticles are relatively inert towards dissociation of thiophene. We believe that the interaction of R-SH compounds with Au-encapsulated Mo nanoparticles proceeds through intermediacy of surface gold thiolates. (C) 2004 Elsevier B.V. All rights reserved. C1 Brookhaven Natl Lab, Dept Chem, Upton, NY 11973 USA. SUNY Stony Brook, Dept Chem, Stony Brook, NY 11790 USA. RP White, MG (reprint author), Brookhaven Natl Lab, Dept Chem, Bldg 555, Upton, NY 11973 USA. EM mgwhite@bnl.gov NR 47 TC 18 Z9 18 U1 2 U2 19 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0039-6028 J9 SURF SCI JI Surf. Sci. PD JAN 10 PY 2005 VL 574 IS 2-3 BP 244 EP 258 DI 10.1016/j.susc.2004.10.035 PG 15 WC Chemistry, Physical; Physics, Condensed Matter SC Chemistry; Physics GA 892PR UT WOS:000226663000017 ER PT J AU Zuberi, B Johnson, KS Aleks, GK Molina, LT Laskin, A AF Zuberi, B Johnson, KS Aleks, GK Molina, LT Laskin, A TI Hydrophilic properties of aged soot SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID SCANNING-ELECTRON-MICROSCOPY; BLACK CARBON; AEROSOL-PARTICLES; OXIDATION; WATER; KINETICS; TROPOSPHERE; SATELLITE; CHEMISTRY; MECHANISM AB [ 1] The global presence of soot has significant effects on regional and global climate, as well as human health. Influence of soot on radiation budget, rain formation and heterogeneous chemistry, and its residence time in the atmosphere are largely dependent on its ability to interact with water. While freshly emitted soot is extremely hydrophobic, oxidation during aging causes soot to become more hydrophilic. Laboratory studies demonstrate that aged soot attracts and retains water, and can be efficiently removed from the troposphere by entrapment in existing liquid cloud droplets or by activation as cloud condensation nuclei. C1 MIT, Dept Chem, Cambridge, MA 02139 USA. MIT, Dept Earth Atmospher & Planetary Sci, Cambridge, MA 02139 USA. Pacific NW Natl Lab, William R Wiley Environm Mol Sci Lab, Richland, WA 99352 USA. RP Zuberi, B (reprint author), GEO2 Technol, 27 Saddle Hill Rd, Weston, MA 02493 USA. EM bilal@alum.mit.edu RI Keppel-Aleks, Gretchen/A-3239-2013; Laskin, Alexander/I-2574-2012 OI Laskin, Alexander/0000-0002-7836-8417 NR 37 TC 84 Z9 85 U1 3 U2 30 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 JAN 8 PY 2005 VL 32 IS 1 AR L01807 DI 10.1029/2004GL021496 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 890KT UT WOS:000226510800003 ER PT J AU Jang, SJ Newton, MD AF Jang, SJ Newton, MD TI Theory of torsional non-Condon electron transfer: A generalized spin-boson Hamiltonian and its nonadiabatic limit solution SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID SOLVENT REORGANIZATION ENERGY; CHARGE-TRANSFER; HOLE TRANSFER; PHENYLENEVINYLENE OLIGOMERS; SUPEREXCHANGE MECHANISM; VARIATIONAL CALCULATION; TEMPERATURE-DEPENDENCE; CONFORMATIONAL-CHANGES; FLUCTUATING BRIDGES; BORN-OPPENHEIMER AB The paper develops a theory of electron transfer with torsionally induced non-Condon (NC) effects. The starting point of the theory is a generalized spin-boson Hamiltonian, where an additional torsional oscillator bilinearly coupled to other bath modes causes a sinusoidal NC modulation. We derive closed form time dependent nonadiabatic rate expressions for both sudden and relaxed initial conditions, which are applicable for general spectral densities and energetic condition. Under the assumption that the torsional motion is not correlated with the polaronic shift of the bath, simple stationary limit rate expression is obtained. Model calculations of this rate expression illustrate the effects of torsional quantization and gating on the driving force and temperature dependences of the electron transfer rate. The classical limit of the rate expression consists of three Marcus-type terms, and is shown to agree very well with the exact numerical result. (C) 2005 American Institute of Physics. C1 Brookhaven Natl Lab, Dept Chem, Upton, NY 11973 USA. RP Jang, SJ (reprint author), Brookhaven Natl Lab, Dept Chem, Upton, NY 11973 USA. EM sjang@bnl.gov; newton@bnl.gov NR 71 TC 19 Z9 19 U1 1 U2 11 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD JAN 8 PY 2005 VL 122 IS 2 AR 024501 DI 10.1063/1.1828431 PG 15 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 893DH UT WOS:000226699000030 PM 15638592 ER PT J AU Lee, TG Rochow, C Martin, R Clark, TK Forrey, RC Balakrishnan, N Stancil, PC Schultz, DR Dalgarno, A Ferland, GJ AF Lee, TG Rochow, C Martin, R Clark, TK Forrey, RC Balakrishnan, N Stancil, PC Schultz, DR Dalgarno, A Ferland, GJ TI Close-coupling calculations of low-energy inelastic and elastic processes in He-4 collisions with H-2: A comparative study of two potential energy surfaces SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID RO-VIBRATIONAL TRANSITIONS; ATOM-MOLECULE COLLISIONS; RATE CONSTANTS; CROSS-SECTIONS; RELAXATION; SCATTERING; COLD; TEMPERATURES; DIFFRACTION; EXCITATION AB The two most recently published potential energy surfaces (PESs) for the HeH2 complex, the so-called MR (Muchnick and Russek) and BMP (Boothroyd, Martin, and Peterson) surfaces, are quantitatively evaluated and compared through the investigation of atom-diatom collision processes. The BMP surface is expected to be an improvement, approaching chemical accuracy, over all conformations of the PES compared to that of the MR surface. We found significant differences in inelastic rovibrational cross sections computed on the two surfaces for processes dominated by large changes in target rotational angular momentum. In particular, the H-2(nu=1,j=0) total quenching cross section computed using the BMP potential was found to be a factor of 1000 larger than that obtained with the MR surface. A lesser discrepancy persists over a large range of energies from the ultracold to thermal and occurs for other low-lying initial rovibrational levels. The MR surface was used in previous calculations of the H-2(nu=1,j=0) quenching rate coefficient and gave results in close agreement with the experimental data of Audibert which were obtained for temperatures between 50 and 300 K. Examination of the rovibronic coupling matrix elements, which are obtained following a Legendre expansion of the PES, suggests that the magnitude of the anisotropy of the BMP potential is too large in the interaction region. However, cross sections for elastic and pure rotational processes obtained from the two PESs differ typically by less than a factor of 2. The small differences may be ascribed to the long-range and anharmonic components of the PESs. Exceptions occur for (nu=10,j=0) and (nu=11,j=1) where significant enhancements have been found for the low-energy quenching and elastic cross sections due to zero-energy resonances in the BMP PES which are not present in the MR potential. (C) 2005 American Institute of Physics. C1 Univ Kentucky, Dept Phys & Astron, Lexington, KY 40506 USA. Oak Ridge Natl Lab, Div Phys, Oak Ridge, TN 37831 USA. Penn State Univ, Berks Lehigh Valley Coll, Dept Phys, Reading, PA 19610 USA. Univ Nevada, Dept Chem, Las Vegas, NV 89154 USA. Univ Georgia, Dept Phys & Astron, Athens, GA 30602 USA. Univ Georgia, Ctr Simulat Phys, Athens, GA 30602 USA. Harvard Smithsonian Ctr Astrophys, Inst Theoret Atom & Mol Phys, Cambridge, MA 02138 USA. RP Lee, TG (reprint author), Univ Kentucky, Dept Phys & Astron, Lexington, KY 40506 USA. RI Lee, Teck Ghee/D-5037-2012 OI Lee, Teck Ghee/0000-0001-9472-3194 NR 51 TC 17 Z9 18 U1 1 U2 5 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD JAN 8 PY 2005 VL 122 IS 2 AR 024307 DI 10.1063/1.1833351 PG 9 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 893DH UT WOS:000226699000024 PM 15638586 ER PT J AU Wang, GF Van Hove, MA Ross, PN Baskes, MI AF Wang, GF Van Hove, MA Ross, PN Baskes, MI TI Monte Carlo simulations of segregation in Pt-Ni catalyst nanoparticles SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID EMBEDDED-ATOM-METHOD; ENERGY ELECTRON-DIFFRACTION; FACE-RELATED SEGREGATION; SURFACE-SANDWICH SEGREGATION; TRANSITION-METALS; OXYGEN REDUCTION; ALLOYS; RELAXATION; PARTICLES; CRYSTALS AB We have investigated the segregation of Pt atoms in the surfaces of Pt-Ni nanoparticles, using modified embedded atom method potentials and the Monte Carlo method. The nanoparticles are constructed with disordered fcc configurations at two fixed overall concentrations (50 at. % Pt and 75 at. % Pt). We use octahedral and cubo-octahedral nanoparticles terminated by {111} and {100} facets to examine the extent of the Pt segregation to the nanoparticle surfaces at T=600 K. The model particles contain between 586 and 4033 atoms (particle size ranging from 2.5 to 5 nm). Our results imply that a complete {100}-facet reconstruction could make the cubo-octahendral Pt-Ni nanoparticles most energetically favorable. We predict that at 600 K due to segregation the equilibrium cubo-octahedral Pt50Ni50 nanoparticles with fewer than 1289 atoms and Pt75Ni25 nanoparticles with fewer than 4033 atoms would achieve a surface-sandwich structure, in which the Pt atoms are enriched in the outermost and third atomic shells while the Ni atoms are enriched in the second atomic shell. We also find that, due to an order-disorder transition, the Pt50Ni50 cubo-octahedral nanoparticles containing more than 2406 atoms would form a core-shell structure with a Pt-enriched surface and a Pt-deficient homogenous core. (C) 2005 American Institute of Physics. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Adv Light Source, Berkeley, CA 94720 USA. Univ Calif Davis, Dept Phys, Davis, CA 95616 USA. Los Alamos Natl Lab, Struct & Property Relat Grp MST8, Los Alamos, NM 87545 USA. RP Wang, GF (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. EM gfwang@lbl.gov RI Van Hove, Michel/A-9862-2008 OI Van Hove, Michel/0000-0002-8898-6921 NR 53 TC 78 Z9 79 U1 5 U2 42 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD JAN 8 PY 2005 VL 122 IS 2 AR 024706 DI 10.1063/1.1828033 PG 12 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 893DH UT WOS:000226699000051 PM 15638613 ER PT J AU de Koning, CA Steinberg, JT Gosling, JT Reisenfeld, DB Skoug, RM St Cyr, OC Malayeri, ML Balogh, A Rees, A McComas, DJ AF de Koning, CA Steinberg, JT Gosling, JT Reisenfeld, DB Skoug, RM St Cyr, OC Malayeri, ML Balogh, A Rees, A McComas, DJ TI An unusually fast interplanetary coronal mass ejection observed by Ulysses at 5 AU on 15 November 2003 SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID INTER-PLANETARY SHOCK; SOLAR-WIND; MAGNETIC HOLES; PLASMA OBSERVATIONS; EVENTS; FIELD; ACCELERATION; LASCO; CME; DISTURBANCES AB [1] On 15 November 2003, at similar to 2030 UT, Ulysses/ SWOOPS observed the onset of a large, unusually fast interplanetary coronal mass ejection ( ICME) in the solar wind at 5.2 AU. Ulysses measured the peak solar wind flow speed associated with this event, nu(max) = 993 km s(-1), in the turbulent sheath region preceding the ICME. This is the fastest solar wind speed recorded by Ulysses/ SWOOPS at this distance since November 1992. On 7 November 2003 at 1554 UT, SOHO/ LASCO observed the solar counterpart of this ICME behind the west limb of the Sun; the CME had a plane- of- sky speed of 1995 km s(-1). We believe this CME originated in AR 0486, the same active region responsible for the extremely fast ICMEs that impacted the Earth on 29 and 30 October 2003. The ICME took at least 4.3 days to propagate past Ulysses and had a radial width of similar to 2.1 AU. The ICME was a magnetic cloud, with a depressed proton beta of similar to 0.01 and a smooth rotation of the magnetic field polar angle from 43degrees to 62degrees. In addition, Ulysses/ SWOOPS also observed bidirectional electron streaming throughout the ICME, indicating that even at this distance, closed field lines threaded the entire event. In the days preceding the ICME, Ulysses observed disturbed solar wind conditions, including six shocks from 6 November to 15 November and several small ICMEs, indicating a high degree of solar activity. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Univ Maryland, Dept Phys, College Pk, MD 20742 USA. Univ London Imperial Coll Sci Technol & Med, Blackett Lab, London SW7 2BW, England. SW Res Inst, Space Sci & Engn Div, San Antonio, TX 78228 USA. RP de Koning, CA (reprint author), Los Alamos Natl Lab, MS D466, Los Alamos, NM 87545 USA. EM dekoning@lanl.gov RI Reisenfeld, Daniel/F-7614-2015 NR 44 TC 7 Z9 7 U1 0 U2 4 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0148-0227 J9 J GEOPHYS RES-SPACE JI J. Geophys. Res-Space Phys. PD JAN 8 PY 2005 VL 110 IS A1 AR A01102 DI 10.1029/2004JA010645 PG 12 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 890LN UT WOS:000226512800004 ER PT J AU Kim, KS Davis, IS Macpherson, PA Pedley, TJ Hill, AE AF Kim, KS Davis, IS Macpherson, PA Pedley, TJ Hill, AE TI Osmosis in small pores: a molecular dynamics study of the mechanism of solvent transport SO PROCEEDINGS OF THE ROYAL SOCIETY A-MATHEMATICAL PHYSICAL AND ENGINEERING SCIENCES LA English DT Article DE molecular dynamics; pore transport; solvent flow; osmosis; drag coefficients ID COMPUTER-SIMULATION; WATER TRANSPORT; MEMBRANE PORES; OSMOTIC FLOW; PERMEABILITY; DIFFUSION; KINETICS; FLUIDS; AQUAPORIN-1; MICROPORES AB Osmosis through semi-permeable pores is a complex process by which solvent is driven by its free energy gradient towards a solute-rich reservoir. We have studied osmotic flow across a semi-permeable cylindrical pore using hard-sphere molecular dynamics which simulates osmosis in the absence of attractive forces between solute and solvent. In addition, we recorded the rates of pressure-driven solvent flow and the diffusive flow of labelled solvent under concentration gradients. It is apparent that there are differences, which are radius dependent, between viscous and diffusive solvent permeabilities in small pores. The osmotic flow rate is decreased by allowing solute entry into part of the pore, an effect which is not due to solute obstruction. The flow rate is dependent on the structure of the pore, which for asymmetric pores leads, surprisingly, to flow asymmetry or osmotic rectification. In the absence of any possible viscous rectification at these very low flow rates the effect correlates with changes between diffusive and pressure flows created by the presence of solute, an effect which has been predicted from thermodynamic arguments. The geometry of a semi-permeable pore in relation to the solute size is therefore required to predict the osmotic flow rate, a departure from the classical picture. Finally, by extracting transport parameters from simulations with pure solvent, we examine the departure of observed flow rate from that predicted by continuum mechanics, obtaining drag coefficients which we compare with those derived from hydrodynamics alone. C1 Physiol Lab, Cambridge CB2 3EG, England. Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. Rogers State Univ, Dept Appl Technol, Claremore, OK 74017 USA. Ctr Math Sci, Dept Appl Math & Theoret Phys, Cambridge CB3 0WA, England. RP Kim, KS (reprint author), Physiol Lab, Downing St, Cambridge CB2 3EG, England. EM aehill@ntlworld.com NR 42 TC 11 Z9 11 U1 6 U2 40 PU ROYAL SOC PI LONDON PA 6-9 CARLTON HOUSE TERRACE, LONDON SW1Y 5AG, ENGLAND SN 1364-5021 EI 1471-2946 J9 P ROY SOC A-MATH PHY JI Proc. R. Soc. A-Math. Phys. Eng. Sci. PD JAN 8 PY 2005 VL 461 IS 2053 BP 273 EP 296 DI 10.1088/rspa.2004.1374 PG 24 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 882WC UT WOS:000225969900015 ER PT J AU Sutradhar, A Paulino, GH Gray, LJ AF Sutradhar, A Paulino, GH Gray, LJ TI On hypersingular surface integrals in the symmetric Galerkin boundary element method: application to heat conduction in exponentially graded materials SO INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN ENGINEERING LA English DT Article DE symmetric Galerkin; boundary element method; functionally graded materials; diffusion; hypersingular integrals; Green's function ID FRACTURE-ANALYSIS; 3D BEM; ELASTICITY; EQUATION; KERNEL AB A symmetric Galerkin formulation and implementation for heat conduction in a three-dimensional functionally graded material is presented. The Green's function of the graded problem, in which the thermal conductivity varies exponentially in one co-ordinate, is used to develop a boundary-only formulation without any domain discretization. The main task is the evaluation of hypersingular and singular integrals. which is carried Out using a direct 'limit to the boundary' approach. However, due to complexity of the Green's function for graded materials, the usual direct limit procedures have to be modified, incorporating Taylor expansions to obtain expressions that can be integrated analytically. Several test examples are provided to verify the numerical implementation. The results of test calculations are in good agreement with exact solutions and corresponding finite element method simulations. Copyright (C) 2004 John Wiley Sons, Ltd. C1 Univ Illinois, Dept Civil & Environm Engn, Netwark Lab, Urbana, IL 61801 USA. Oak Ridge Natl Lab, Comp Sci & Math Div, Oak Ridge, TN 37831 USA. RP Paulino, GH (reprint author), Univ Illinois, Dept Civil & Environm Engn, Netwark Lab, 205 N Mathews Ave, Urbana, IL 61801 USA. EM paulino@uiuc.edu RI Paulino, Glaucio/A-2426-2008; OI Sutradhar, Alok/0000-0001-8166-9950 NR 39 TC 15 Z9 15 U1 0 U2 0 PU JOHN WILEY & SONS LTD PI CHICHESTER PA THE ATRIUM, SOUTHERN GATE, CHICHESTER PO19 8SQ, W SUSSEX, ENGLAND SN 0029-5981 J9 INT J NUMER METH ENG JI Int. J. Numer. Methods Eng. PD JAN 7 PY 2005 VL 62 IS 1 BP 122 EP 157 DI 10.1002/nme.1195 PG 36 WC Engineering, Multidisciplinary; Mathematics, Interdisciplinary Applications SC Engineering; Mathematics GA 881ZL UT WOS:000225908000006 ER PT J AU Waddell, R Dale, DE Monagle, M Smith, SA AF Waddell, R Dale, DE Monagle, M Smith, SA TI Determination of nitroaromatic and nitramine explosives from a PTFE wipe using thermal desorption-gas chromatography with electron-capture detection SO JOURNAL OF CHROMATOGRAPHY A LA English DT Article DE explosives; thermal desorption; GC-ECD; dry wipe; dual column; dual ECD ID NITRATE ESTER EXPLOSIVES; TRACE ANALYSIS; LIQUID-CHROMATOGRAPHY; MOBILITY SPECTROMETRY; MASS-SPECTROMETRY; WATER; EXTRACTION; SAMPLES; SOIL AB A method for the detection of nitroaromatic and nitramine explosives from a PTFE wipe has been developed using thermal desorption and gas chromatography with electron-capture detection (TD-GC-ECD). For method development a standard mixture containing eight nitroaromatic and two nitramine (HMX and RDX) explosive compounds was spiked onto a PTFE wipe. Explosives were desorbed from the wipe in a commercial thermal desorption system and trapped onto a cooled injection system, which was incorporated into the injection port of the GC. A dual column, dual ECD configuration was adopted to enable simultaneous confirmation analysis of the explosives desorbed. For the desorption of 50ng of each explosive, desorption efficiencies ranged between 80.0 and 117%, for both columns. Linearity over the range 2.5-50 ng was demonstrated for each explosive on both columns with r(2) values ranging from 0.979 to 0.991 and limits of detection less than 4 ng. Desorption of HMX from a PTFE wipe has also been demonstrated for the first time, albeit at relatively high loadings (100 ng). (C) 2004 Elsevier B.V. All rights reserved. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Adv Ind Corp, Albuquerque, NM 87114 USA. RP Dale, DE (reprint author), Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. EM ddale@lanl.gov OI Waddell Smith, Ruth/0000-0002-2574-7974 NR 25 TC 30 Z9 32 U1 4 U2 19 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0021-9673 J9 J CHROMATOGR A JI J. Chromatogr. A PD JAN 7 PY 2005 VL 1062 IS 1 BP 125 EP 131 DI 10.1016/j.chroma.2004.11.028 PG 7 WC Biochemical Research Methods; Chemistry, Analytical SC Biochemistry & Molecular Biology; Chemistry GA 886WZ UT WOS:000226265000014 PM 15679150 ER PT J AU Cai, Y Koshino, N Saha, B Espenson, JH AF Cai, Y Koshino, N Saha, B Espenson, JH TI Kinetics of self-decomposition and hydrogen atom transfer reactions of substituted phthalimide N-oxyl radicals in acetic acid SO JOURNAL OF ORGANIC CHEMISTRY LA English DT Article ID FACTORS CONTROLLING REACTIVITY; MOLECULAR-OXYGEN; AEROBIC OXIDATION; BENZYL ALCOHOLS; CHARGE-TRANSFER; RATE CONSTANTS; ABSTRACTIONS; HYDROXYPHTHALIMIDES; NITROXIDE; CATALYSTS AB Kinetic data have been obtained for three distinct types of reactions of plathalimide N-oxyl radicals (PINO.) and N-hydroxyphthalimide (NHPI) derivatives. The first is the self-decomposition of PINO. which was found to follow second-order kinetics. In the self-decomposition of 4-methyl-Nhydroxyphthalimide (4-Me-NHPI), H-atom abstraction competes with self-decomposition in the presence of excess 4-Me-NHPI. The second set of reactions studied is hydrogen atom transfer from NHPI to PINO., e.g., PINO. + 4-Me-NHPI reversible arrow NHPI + 4-Me-PINO.. The substantial KIE, k(H)/k(D) = 11 for both forward and reverse reactions, supports the assignment of H-atom transfer rather than stepwise electron-proton transfer. These data were correlated with the Marcus cross relation for hydrogen-atom transfer, and good agreement between the experimental and the calculated rate constants was obtained. The third reaction studied is hydrogen abstraction by PINO. from p-xylene and toluene. The reaction becomes regularly slower as the ring substituent on PINO. is more electron donating. Analysis by the Hammett equation gave p = 1.1 and. 1.8 for the reactions of PINO. with p-xylene and toluene, respectively. 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. EM espenson@iastate.edu NR 29 TC 33 Z9 33 U1 7 U2 18 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0022-3263 J9 J ORG CHEM JI J. Org. Chem. PD JAN 7 PY 2005 VL 70 IS 1 BP 238 EP 243 DI 10.1021/jo048418t PG 6 WC Chemistry, Organic SC Chemistry GA 890JX UT WOS:000226508600029 PM 15624928 ER PT J AU Sood, V Redner, S Ben-Avraham, D AF Sood, V Redner, S Ben-Avraham, D TI First-passage properties of the Erdos-Renyi random graph SO JOURNAL OF PHYSICS A-MATHEMATICAL AND GENERAL LA English DT Article ID DIFFUSION; NETWORKS AB We study the mean time for a random walk to traverse between two arbitrary sites of the Erdos-Renyi random graph. We develop an effective medium approximation that predicts that the mean first-passage time between pairs of nodes, as well as all moments of this first-passage time, are insensitive to the fraction p of occupied links. This prediction qualitatively agrees with numerical simulations away from the percolation threshold. Near the percolation threshold, the statistically meaningful quantity is the mean transit rate, namely, the inverse of the first-passage time. This rate varies non-monotonically with p near the percolation transition. Much of this behaviour can be understood by simple heuristic arguments. C1 Los Alamos Natl Lab, Div Theory, Los Alamos, NM 87545 USA. Los Alamos Natl Lab, Ctr Nonlinear Studies, Los Alamos, NM 87545 USA. Clarkson Univ, Dept Phys, Potsdam, NY 13699 USA. RP Sood, V (reprint author), Los Alamos Natl Lab, Div Theory, POB 1663, Los Alamos, NM 87545 USA. EM vsood@bu.edu; redner@bu.edu; qd00@clarkson.edu NR 26 TC 52 Z9 52 U1 1 U2 4 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0305-4470 J9 J PHYS A-MATH GEN JI J. Phys. A-Math. Gen. PD JAN 7 PY 2005 VL 38 IS 1 BP 109 EP 123 DI 10.1088/0305-4470/38/1/007 PG 15 WC Physics, Multidisciplinary; Physics, Mathematical SC Physics GA 892KG UT WOS:000226648800010 ER PT J AU Verlet, JRR Bragg, AE Kammrath, A Cheshnovsky, O Neumark, DM AF Verlet, JRR Bragg, AE Kammrath, A Cheshnovsky, O Neumark, DM TI Observation of large water-cluster anions with surface-bound excess electrons SO SCIENCE LA English DT Article ID HYDRATED-ELECTRON; PHOTOELECTRON-SPECTROSCOPY; DYNAMICS; ION; SPECTRA; ENERGETICS; ISOMERS; BULK; TIME AB Anionic water clusters have long been studied to infer properties of the bulk hydrated electron. We used photoelectron imaging to characterize a class of (H2O)(n)(-) and (D2O)(n)(-) cluster anions (n less than or equal to 200 molecules) with vertical binding energies that are significantly lower than those previously recorded. The data are consistent with a structure in which the excess electron is bound to the surface of the cluster. This result implies that the excess electron in previously observed water-cluster anions, with higher vertical binding energies, was internally solvated. Thus, the properties of those clusters could be extrapolated to those of the bulk hydrated electron. C1 Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. Tel Aviv Univ, Sackler Fac Exact Sci, Sch Chem, IL-69978 Tel Aviv, Israel. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Chem Sci, Berkeley, CA 94720 USA. RP Neumark, DM (reprint author), Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. EM dneumark@berkeley.edu RI Neumark, Daniel/B-9551-2009; Verlet, Jan/G-5940-2012 OI Neumark, Daniel/0000-0002-3762-9473; Verlet, Jan/0000-0002-9480-432X NR 28 TC 280 Z9 283 U1 6 U2 84 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 JAN 7 PY 2005 VL 307 IS 5706 BP 93 EP 96 DI 10.1126/science.1106719 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 886GG UT WOS:000226214300043 PM 15604360 ER PT J AU Yagci, B Frazho, AE Sumali, H AF Yagci, B Frazho, AE Sumali, H TI Determining the extension of a hydraulic cylinder using spectral estimation SO JOURNAL OF SOUND AND VIBRATION LA English DT Article ID NOISE C1 Purdue Univ, Sch Aeronaut & Astronaut Engn, W Lafayette, IN 47907 USA. Purdue Univ, Dept Agr & Biol Engn, W Lafayette, IN 47907 USA. RP Sumali, H (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. EM hsumali@sandia.gov NR 10 TC 9 Z9 9 U1 1 U2 2 PU ACADEMIC PRESS LTD ELSEVIER SCIENCE LTD PI LONDON PA 24-28 OVAL RD, LONDON NW1 7DX, ENGLAND SN 0022-460X J9 J SOUND VIB JI J. Sound Vibr. PD JAN 6 PY 2005 VL 279 IS 1-2 BP 487 EP 496 DI 10.1016/j.jsv.2004.01.052 PG 10 WC Acoustics; Engineering, Mechanical; Mechanics SC Acoustics; Engineering; Mechanics GA 874FS UT WOS:000225336900023 ER PT J AU Mathur, N Chen, Y Dong, SJ Draper, T Horvath, I Lee, FX Liu, KF Zhang, JB AF Mathur, N Chen, Y Dong, SJ Draper, T Horvath, I Lee, FX Liu, KF Zhang, JB TI Roper resonance and S-11 (1535) from lattice QCD SO PHYSICS LETTERS B LA English DT Article ID BREATHING MODE; QUARK-MODEL; SPECTRUM; BARYONS; SIGNATURES; SKYRMION; MASS AB Using the constrained-curve fitting method and overlap fermions with the lowest pion mass at 180 MeV, we observe that the masses of the first positive and negative parity excited states of the nucleon tend to cross over as the quark masses are taken to the chiral limit. Both results at the physical pion mass agree with the experimental values of the Roper resonance (N1/2+(1440)) and S-11 (N1/2- (1535)). This is seen for the first time in a lattice QCD calculation. These results are obtained on a quenched Iwasaki 16(3) x 28 lattice with a = 0.2 fm. We also extract the ghost eta'N states (a quenched artifact) which are shown to decouple from the nucleon interpolation field above mpi similar to 300 MeV. From the quark mass dependence of these states in the chiral region, we conclude that spontaneously broken chiral symmetry dictates the dynamics of light quarks in the nucleon. (C) 2004 Elsevier B.V. All rights reserved. C1 Univ Kentucky, Dept Phys & Astron, Lexington, KY 40506 USA. Chinese Acad Sci, Inst High Energy Phys, Beijing 100039, Peoples R China. George Washington Univ, Dept Phys, Ctr Nucl Studies, Washington, DC 20052 USA. Jefferson Lab, Newport News, VA 23606 USA. Univ Adelaide, CSSM, Adelaide, SA 5005, Australia. Univ Adelaide, Dept Phys & Math Phys, Adelaide, SA 5005, Australia. RP Horvath, I (reprint author), Univ Kentucky, Dept Phys & Astron, Lexington, KY 40506 USA. EM liu@pa.uky.edu OI Lee, Frank/0000-0001-8169-3440 NR 29 TC 80 Z9 81 U1 2 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 JAN 6 PY 2005 VL 605 IS 1-2 BP 137 EP 143 DI 10.1016/j.physletb.2004.11.010 PG 7 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 886HQ UT WOS:000226217900017 ER PT J AU Martinovic, L Luban, M AF Martinovic, L Luban, M TI Analytic solution of the microcausality problem in discretized light cone quantization SO PHYSICS LETTERS B LA English DT Article ID FIELD-THEORY AB lt is shown that violation of causality in two-dimensional light-front field theories quantized in a finite "volume" L with periodic or antiperiodic boundary conditions is marginal and vanishes smoothly in the continuum limit. For this purpose, we derive an exact integral representation for the complete infinite series expansion of the two-point functions of a free massive scalar and Fermi field for an arbitrary finite value of L and show that in the L --> infinity limit we retrieve the correct continuum results. (C) 2004 Elsevier B.V. All rights reserved. C1 Slovak Acad Sci, Inst Phys, Bratislava 84511, Slovakia. Iowa State Univ, Ames Lab, Ames, IA 50011 USA. Iowa State Univ, Dept Phys & Astron, Ames, IA 50011 USA. RP Martinovic, L (reprint author), Slovak Acad Sci, Inst Phys, Dubravska Cesta 9, Bratislava 84511, Slovakia. EM fyziluma@savba.sk; luban@ameslab.gov NR 12 TC 5 Z9 5 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0370-2693 J9 PHYS LETT B JI Phys. Lett. B PD JAN 6 PY 2005 VL 605 IS 1-2 BP 203 EP 213 DI 10.1016/j.physletb.2004.11.028 PG 11 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 886HQ UT WOS:000226217900025 ER PT J AU Galloway, JA Jeon, HK Bell, JR Macosko, CW AF Galloway, JA Jeon, HK Bell, JR Macosko, CW TI Block copolymer compatibilization of cocontinuous polymer blends SO POLYMER LA English DT Article DE copolymer; cocontinuous; polystyrene-polyethylene block copolymers ID POLYETHYLENE POLYSTYRENE BLENDS; CO-CONTINUOUS MORPHOLOGIES; INTERFACIAL-TENSION; POLYSTYRENE/POLY(DIMETHYLSILOXANE) BLENDS; MECHANICAL-PROPERTIES; PHASE MORPHOLOGY; MOLECULAR DESIGN; INVERSION; CONTINUITY; STABILITY AB The effect of block copolymers on the cocontinuous morphology of 50/50 (w/w) polystyrene (PS)/high density polyethylene (HDPE) blends was investigated using symmetric polystyrene-polyethylene block copolymers (PS-PE) with molecular weights varying from 6 to 200 kg/mol. The coarsening rate during annealing was compared to the Doi-Ohta theory. An intermediate molecular weight PS-PE, 40 kg/mol, showed remarkable results in reducing the phase size and stabilizing the blend morphology during annealing. Mixing small amounts of 6, 100 or 200 kg/mol PS-PE in the blend did not reduce the phase size significantly, but did decrease the coarsening rate during annealing. In stabilizing the morphology, 6 kg/mol PS-PE was inferior to 100 and 200 kg/mol. The existence of an optimal molecular weight block copolymer is due to a balance between the ability of the block copolymer to reach the interface and its relative stabilization effect at the interface. (C) 2004 Elsevier Ltd. All rights reserved. C1 Univ Minnesota, Dept Mat Sci & Chem Engn, Minneapolis, MN 55455 USA. Sandia Natl Labs, Albuquerque, NM 87185 USA. Dow Chem Co USA, Midland, MI 48674 USA. RP Macosko, CW (reprint author), Univ Minnesota, Dept Mat Sci & Chem Engn, Minneapolis, MN 55455 USA. EM bell@cems.umn.edu NR 36 TC 78 Z9 82 U1 2 U2 37 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 JAN 6 PY 2005 VL 46 IS 1 BP 183 EP 191 DI 10.1016/j.polymer.2004.10.061 PG 9 WC Polymer Science SC Polymer Science GA 887OZ UT WOS:000226316700020 ER PT J AU Silver, GL AF Silver, GL TI Analysis of three-dimensional grids: five- and nine-point cubes SO APPLIED MATHEMATICS AND COMPUTATION LA English DT Article DE cubes; operational equations; response surfaces; quadratic cocificients; three-dimensional grids ID DIAMOND CONFIGURATION AB It is widely believed that quadratic coefficients cannot be estimated from nine data in cubical array. This paper illustrates three equations for that array and one equation for the five-point array. The quadratic coefficients obtained by the equations are compared to the true values as obtained by Taylor expansions of typical generating functions. The accuracy of the estimated coefficients may be sufficient to interest experimentalists. (C) 2003 Elsevier Inc. All rights reserved. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Silver, GL (reprint author), Los Alamos Natl Lab, POB 1663,MS E500, Los Alamos, NM 87545 USA. EM gsilver@lanl.gov NR 5 TC 7 Z9 7 U1 0 U2 0 PU ELSEVIER SCIENCE INC PI NEW YORK PA 360 PARK AVE SOUTH, NEW YORK, NY 10010-1710 USA SN 0096-3003 J9 APPL MATH COMPUT JI Appl. Math. Comput. PD JAN 5 PY 2005 VL 160 IS 1 BP 133 EP 140 DI 10.1016/j.amc.2003.08.152 PG 8 WC Mathematics, Applied SC Mathematics GA 873HE UT WOS:000225269700012 ER PT J AU Cellmer, T Bratko, D Prausnitz, JM Blanch, H AF Cellmer, T Bratko, D Prausnitz, JM Blanch, H TI The competition between protein folding and aggregation: Off-lattice minimalist model studies SO BIOTECHNOLOGY AND BIOENGINEERING LA English DT Article DE protein refolding; computer simulation; protein aggregation ID FIBRIL FORMATION; IN-VITRO; KINETICS; SIMULATION; THERMODYNAMICS; INTERMEDIATE; PROPAGATION; LANDSCAPES; TIMESCALES; MECHANISM AB Protein aggregation has been associated with a number of human diseases, and is a serious problem in the manufacture of recombinant proteins. Of particular interest to the biotechnology industry is deleterious aggregation that occurs during the refolding of proteins from inclusion bodies. As a complement to experimental efforts, computer simulations of multi-chain systems have emerged as a powerful tool to investigate the competition between folding and aggregation. Here we report results from Langevin dynamics simulations of minimalist model proteins. Order parameters are developed to follow both folding and aggregation. By mapping natural units to real units, the simulations are shown to be carried out under experimentally relevant conditions. Data pertaining to the contacts formed during the association process show that multiple mechanisms for aggregation exist, but certain pathways are statistically preferred. Kinetic data show that there are multiple time scales for aggregation, although most association events take place at times much shorter than those required for folding. Last, we discuss results presented here as a basis for future work aimed at rational design of mutations to reduce aggregation propensity, as well as for development of small-molecular weight refolding enhancers. (C) 2004 Wiley Periodicals, Inc. C1 Univ Calif Berkeley, Dept Chem Engn, Berkeley, CA 94720 USA. Virginia Commonwealth Univ, Dept Chem, Richmond, VA 23284 USA. Lawrence Berkeley Lab, Div Chem Sci, Berkeley, CA 94720 USA. RP Univ Calif Berkeley, Dept Chem Engn, Berkeley, CA 94720 USA. EM blanch@socrates.berkeley.edu NR 43 TC 23 Z9 24 U1 1 U2 2 PU WILEY-BLACKWELL PI HOBOKEN PA 111 RIVER ST, HOBOKEN 07030-5774, NJ USA SN 0006-3592 EI 1097-0290 J9 BIOTECHNOL BIOENG JI Biotechnol. Bioeng. PD JAN 5 PY 2005 VL 89 IS 1 BP 78 EP 87 DI 10.1002/bit.20302 PG 10 WC Biotechnology & Applied Microbiology SC Biotechnology & Applied Microbiology GA 884XV UT WOS:000226120900008 PM 15540197 ER PT J AU Worrell, E AF Worrell, E TI Energy at the crossroads: Global perspectives and uncertainties SO ECOLOGICAL ECONOMICS LA English DT Book Review C1 Lawrence Berkeley Natl Lab, Environm Energy Technol Div, Energy Anal Dept, Berkeley, CA 94720 USA. RP Worrell, E (reprint author), Lawrence Berkeley Natl Lab, Environm Energy Technol Div, Energy Anal Dept, MS 90-4000,1 Cyclotron Rd, Berkeley, CA 94720 USA. EM EWorrell@lbl.gov RI Worrell, Ernst/L-5455-2013 OI Worrell, Ernst/0000-0002-0199-9755 NR 1 TC 0 Z9 0 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-8009 J9 ECOL ECON JI Ecol. Econ. PD JAN 5 PY 2005 VL 52 IS 1 BP 128 EP 129 DI 10.1016/j.ecolecon.2004.07.007 PG 2 WC Ecology; Economics; Environmental Sciences; Environmental Studies SC Environmental Sciences & Ecology; Business & Economics GA 893NV UT WOS:000226727400010 ER PT J AU Li, LY King, DL AF Li, LY King, DL TI High-capacity sulfur dioxide absorbents for diesel emissions control SO INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH LA English DT Article ID OCTAHEDRAL MOLECULAR-SIEVES; MANGANESE OXIDE; SO2; TODOROKITE AB High-capacity sulfur dioxide absorbents based on manganese oxide octahedral molecular sieves (OMS) have been identified. These materials are based on MnO6 octahedra sharing faces and edges to form various tunnel structures (2 x 2, 2 x 3, 2 x 4, 3 x 3) differentiated by the number of octahedra on a side. The SO2 capacities of these materials, measured at 325 degreesC with a feed containing 250 ppmv SO2 in air, are as high as 70 wt % (w/w), remarkably higher than conventional metal oxide based SO2 absorbents. Among the OMS materials, the 2 x 2 member, cryptomelane, exhibits the highest capacity and absorption rate. Its SO2 absorption behavior has been further characterized as a function of temperature, space velocity, and feed composition. The dominant pathway for SO2 absorption is through the oxidation Of SO2 to SO3 by Mn4+ followed by SO3 reaction with Mn2+ to form MnSO4. Absorption can occur in the absence of gas-phase oxygen, with a moderate loss in overall capacity. The inclusion of gases NO and CO in the feed does not reduce SO2 capacity. The absorption capacity decreases at high space velocity and low absorption temperature. A color change of cryptomelane from black to yellow-brown after SO2 absorption can be used as an indicator of absorption progress. Cryptomelane can be synthesized using MnSO4 as a reagent. Therefore, after full SO2 absorption, the product MnSO4 can be reused as raw material for a subsequent cryptomelane synthesis. Cryptomelane has a similarly high capacity toward SO3; therefore, it can be used for removal of all SOx species generated from a variety of combustion sources. Cryptomelane may find application as a replaceable absorbent for the removal of SOx from diesel truck exhaust, protecting downstream emissions control devices such as particulate filters and NOx traps. C1 Pacific NW Natl Lab, Div Mat, Richland, WA 99354 USA. RP King, DL (reprint author), Pacific NW Natl Lab, Div Mat, POB 999, Richland, WA 99354 USA. EM david.king@pnl.gov NR 14 TC 18 Z9 19 U1 1 U2 10 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0888-5885 J9 IND ENG CHEM RES JI Ind. Eng. Chem. Res. PD JAN 5 PY 2005 VL 44 IS 1 BP 168 EP 177 DI 10.1021/ie049111n PG 10 WC Engineering, Chemical SC Engineering GA 890KN UT WOS:000226510200018 ER PT J AU Bae, JM Ahmed, S Kumar, R Doss, E AF Bae, JM Ahmed, S Kumar, R Doss, E TI Microchennel development for autothermal reforming of hydrocarbon fuels SO JOURNAL OF POWER SOURCES LA English DT Article DE fuel cell; fuel-processing; autothermal reforming; microchannel; catalyst AB Fuel-processing is a bridging technology to assist the commercialization of fuel cell systems in the absence of a hydrogen infrastructure. The Argonne National Laboratory has been developing fuel-processing technologies for fuel cells, and has reported the development of novel catalysts that are active and selective for hydrocarbon-reforming reactions. It has been realized, however, that with pellets or conventional honeycomb catalysts, the reforming process is mass-transport limited. This study addresses the development of catalysts structures with microchannels that are able to reduce the diffusion resistance and, thereby, achieve the same production rate within a smaller reactor bed. The microchannel reforming catalysts are prepared and tested with natural gas and gasoline-type fuels in a microreactor (diameter: 1 cm) at space velocities of up to 250 000 h(-1). The catalysts have also been used in engineering-scale reactors (10 kWe; diameter: 7 cm) with similar product qualities. Compared with pellet catalysts, the microchannel catalysts offer a nearly five-fold reduction in catalyst weight and volume. (C) 2004 Published by Elsevier B.V. C1 Korea Adv Inst Sci & Technol, Dept Mech Engn, Taejon, South Korea. Argonne Natl Lab, Argonne, IL 60439 USA. RP Bae, JM (reprint author), Korea Adv Inst Sci & Technol, Dept Mech Engn, Taejon, South Korea. EM jmbae@kaist.ac.kr RI Bae, joongmyeon/C-1608-2011 NR 4 TC 31 Z9 38 U1 4 U2 7 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0378-7753 J9 J POWER SOURCES JI J. Power Sources PD JAN 4 PY 2005 VL 139 IS 1-2 BP 91 EP 95 DI 10.1016/j.jpowsour.2004.05.054 PG 5 WC Chemistry, Physical; Electrochemistry; Energy & Fuels; Materials Science, Multidisciplinary SC Chemistry; Electrochemistry; Energy & Fuels; Materials Science GA 886XG UT WOS:000226265800014 ER PT J AU Vernon, DR Meng, FQ Dec, SF Williamson, DL Turner, JA Herring, AM AF Vernon, DR Meng, FQ Dec, SF Williamson, DL Turner, JA Herring, AM TI Synthesis, characterization, and conductivity measurements of hybrid membranes containing a mono-lacunary heteropolyacid for PEM fuel cell applications SO JOURNAL OF POWER SOURCES LA English DT Article DE fuel cell; heteropolyacid; proton exchange membrane; hybrid nano-composite; membrane electrode assembly ID POLYMER ELECTROLYTE MEMBRANE; 12-TUNGSTOPHOSPHORIC ACID; ELEVATED-TEMPERATURES; COMPOSITE MEMBRANES; POLYBENZIMIDAZOLE; PERFORMANCE; DIFFUSION; OPERATION; H3PW12O40 AB Hybrid inorganic/organic membranes using a lacunary heteropolyacid proton conductor, H8SiW11O39, in stable polymer matrices based on polyethylene glycol were prepared by a sol-gel method. NMR and IR measurements indicate that this improved sol-gel membrane contains robust covalent bonds between the proton conductor and polymer backbone. However, the polymer in these model systems is not expected to be oxidatively stable. Diffusion coefficients measured for this material, 1.2 x 10(-6) cm(2) s(-1), are of the same order of magnitude as for to that of Nafion(R) whilst ion exchange capacities, 2-2.5 meq g(-1), are twice that of Nafion(R) 117. The temperature dependence of the conductivity increases exponentially with temperature. However, fuel cell performance of this material is poor when compared to a Nafion(R) 117 membrane electrode assembly (MEA). One possible explanation is that there is a lack of organization of the proton conducting elements in the hybrid material. In addition, ex situ membrane conductivity measurements compared to in situ MEA polarization measurements reveal large interfacial resistances in the hybrid membrane MEAs. Further, it appears that these membranes, as currently formulated, require quite stringent humidification requirements for maximum performance. (C) 2004 Elsevier B.V. All rights reserved. C1 Colorado Sch Mines, Dept Chem Engn, Golden, CO 80401 USA. Colorado Sch Mines, Dept Chem & Geochem, Golden, CO 80401 USA. Colorado Sch Mines, Dept Phys, Golden, CO 80401 USA. Natl Renewable Energy Lab, Hydrogen & Elect Syst & Infrastruct Grp, Golden, CO 80401 USA. RP Colorado Sch Mines, Dept Chem Engn, Golden, CO 80401 USA. EM jturner@nrel.gov; aherring@mines.edu RI Herring, Andy/E-7088-2010; OI Herring, Andrew/0000-0001-7318-5999 NR 45 TC 68 Z9 69 U1 1 U2 19 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0378-7753 EI 1873-2755 J9 J POWER SOURCES JI J. Power Sources PD JAN 4 PY 2005 VL 139 IS 1-2 BP 141 EP 151 DI 10.1016/j.jpowsour.2004.07.027 PG 11 WC Chemistry, Physical; Electrochemistry; Energy & Fuels; Materials Science, Multidisciplinary SC Chemistry; Electrochemistry; Energy & Fuels; Materials Science GA 886XG UT WOS:000226265800019 ER PT J AU Ahluwalia, RK Wang, X AF Ahluwalia, RK Wang, X TI Direct hydrogen fuel cell systems for hybrid vehicles SO JOURNAL OF POWER SOURCES LA English DT Article DE hydrogen fuel cell; fuel cells for transportation; thermal and water management; air management; fuel cells for hybrid vehicles; cold start of fuel cell systems AB Hybridizing a fuel cell system with an energy storage system offers an opportunity to improve the fuel economy of the vehicle through regenerative braking and possibly to increase the specific power and decrease the cost of the combined energy conversion and storage systems. Even in a hybrid configuration it is advantageous to operate the fuel cell system in a load-following mode and use the power from the energy storage system when the fuel cell alone cannot meet the power demand. This paper discusses an approach for designing load-following fuel cell systems for hybrid vehicles and illustrates it by applying it to pressurized, direct hydrogen, polymer-electrolyte fuel cell (PEFC) systems for a mid-size family sedan. The vehicle level requirements relative to traction power, response time, start-up time and energy conversion efficiency are used to select the important parameters for the PEFC stack, air management system, heat rejection system and the water management system. (C) 2004 Published by Elsevier B.V. C1 Argonne Natl Lab, Argonne, IL 60439 USA. RP Ahluwalia, RK (reprint author), Argonne Natl Lab, 9700 S Cass Ave, Argonne, IL 60439 USA. EM walia@anl.gov NR 8 TC 40 Z9 40 U1 0 U2 9 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0378-7753 J9 J POWER SOURCES JI J. Power Sources PD JAN 4 PY 2005 VL 139 IS 1-2 BP 152 EP 164 DI 10.1016/j.jpowsour.2004.07.018 PG 13 WC Chemistry, Physical; Electrochemistry; Energy & Fuels; Materials Science, Multidisciplinary SC Chemistry; Electrochemistry; Energy & Fuels; Materials Science GA 886XG UT WOS:000226265800020 ER PT J AU Bloom, I Jansen, AN Abraham, DP Knuth, J Jones, SA Battaglia, VS Henriksen, GL AF Bloom, I Jansen, AN Abraham, DP Knuth, J Jones, SA Battaglia, VS Henriksen, GL TI Differential voltage analyses of high-power, lithium-ion cells 1. Technique and application SO JOURNAL OF POWER SOURCES LA English DT Article DE differential voltage; reference electrode; lithium ion; battery ID CHEMICAL DIFFUSION; CATHODE MATERIAL; INTERCALATION; BATTERIES; ELECTRODE; LI; SPECTROSCOPY; GRAPHITE; SYSTEM; SPINEL AB The C/25 discharge data from 18650-size cells containing LiNi0.8Co0.1Al0.1O2 cathode and graphite anode laminates were analyzed through the use of the differential voltage, dV/dQ, curves. Using half-cell data, the peaks in the dV/dQ curve of the full cell data were assigned. Analysis of the relative peak shifts allowed for the determination of the source of capacity fade. For cells formed and aged at 45 degreesC for 40 weeks (capacity fade = 7.5%), the analysis indicated negligible loss of accessible material at the anode and at the cathode. Capacity loss of the cell could be accounted for, largely, by side reactions at the anode. This type of analysis can be used when the introduction of a reference electrode is difficult or impractical. (C) 2004 Elsevier B.V. All rights reserved. C1 Argonne Natl Lab, Electrochem Technol Program, Argonne, IL 60439 USA. RP Bloom, I (reprint author), Argonne Natl Lab, Electrochem Technol Program, 9700 S Cass Ave, Argonne, IL 60439 USA. EM bloom@cmt.anl.gov RI Jansen, Andrew/Q-5912-2016 OI Jansen, Andrew/0000-0003-3244-7790 NR 41 TC 104 Z9 106 U1 7 U2 75 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0378-7753 J9 J POWER SOURCES JI J. Power Sources PD JAN 4 PY 2005 VL 139 IS 1-2 BP 295 EP 303 DI 10.1016/j.jpowsour.2004.07.021 PG 9 WC Chemistry, Physical; Electrochemistry; Energy & Fuels; Materials Science, Multidisciplinary SC Chemistry; Electrochemistry; Energy & Fuels; Materials Science GA 886XG UT WOS:000226265800040 ER PT J AU Bloom, I Christophersen, J Gering, K AF Bloom, I Christophersen, J Gering, K TI Differential voltage analyses of high-power lithium-ion cells 2. Applications SO JOURNAL OF POWER SOURCES LA English DT Article DE differential voltage; reference electrode; lithium ion; battery AB We characterized high-power lithium-ion cells in terms of performance and cycle- and calendar life at 45 degreesC. Among other parameters, we measured the C/25 capacity every 4 weeks during the test. Differentiation of the C/25 voltage versus capacity data with respect to capacity yielded dV/dQ curves. Analysis of Q(0) dV/dQ curves has shown that capacity fade in high-power lithium-ion cells can be complex. From the analysis, the anode material in a significant fraction of the cells showed two types of capacity loss. The loss of accessible material tended to happen early in cell life, either during formation or during the first 4 weeks of testing. Most likely this was caused by a physical rather than chemical process. After 4 weeks, the principal cause of capacity loss was side reactions. (C) 2004 Elsevier B.V. All rights reserved. C1 Argonne Natl Lab, Electrochem Technol Program, Argonne, IL 60439 USA. Idaho Natl Engn & Environm Lab, Idaho Falls, ID 83415 USA. RP Bloom, I (reprint author), Argonne Natl Lab, Electrochem Technol Program, 9700 S Cass Ave, Argonne, IL 60439 USA. EM bloom@cmt.anl.gov NR 8 TC 34 Z9 36 U1 3 U2 28 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0378-7753 J9 J POWER SOURCES JI J. Power Sources PD JAN 4 PY 2005 VL 139 IS 1-2 BP 304 EP 313 DI 10.1016/j.jpowsour.2004.07.022 PG 10 WC Chemistry, Physical; Electrochemistry; Energy & Fuels; Materials Science, Multidisciplinary SC Chemistry; Electrochemistry; Energy & Fuels; Materials Science GA 886XG UT WOS:000226265800041 ER PT J AU Ding, L Weiss, TM Fragneto, G Liu, WH Yang, L Huang, HW AF Ding, L Weiss, TM Fragneto, G Liu, WH Yang, L Huang, HW TI Distorted hexagonal phase studied by neutron diffraction: Lipid components demixed in a bent monolayer SO LANGMUIR LA English DT Article ID FUSION INTERMEDIATE STRUCTURE; MEMBRANE-FUSION; ELASTIC PROPERTIES; STALK MODEL; CURVATURE; PORES; PHOSPHOLIPIDS; TRANSITIONS; ENERGETICS; BILAYERS AB The recent discovery of a distorted hexagonal phase in 1,2-dioleoyl-sn-glycero-3-phosphatidylethanolamine/ 1,2-dioleoyl-sn-glycero-3-phosphatidylcholine (DOPE/DOPC) mixtures raised the intriguing question as to whether lipid mixtures demix in a bent monolayer. We performed neutron diffraction on a mixture of headgroup deuterated DOPC-d(13) and nondeuterated DOPE to study the lipid distribution in the distorted hexagonal phase. The 1:1 lipid mixture in full hydration and 25 degreesC was in a homogeneous lamellar phase. Upon dehydration the mixture transformed to a rhombohedral phase, then to a distorted inverted hexagonal phase, and finally to a regular inverted hexagonal phase. In the distorted hexagonal phase, the diffraction pattern showed a two-dimensional monoclinic lattice with two reciprocal vectors of equal length (1.5 nm(-1)) forming an angle 53degrees between them. Diffraction intensities measured while varying the D2O/H2O ratio in the humidity was used to solve the phase problem. The neutron scattering length density distribution of the distorted hexagonal phase was constructed. The constant density contours are approximately elliptical. The difference in the eccentricities of the contours between the water and lipid distributions indicates that the DOPE/DOPC ratio is not uniform around the elliptical lipid tube in the unit cell. DOPE is preferentially distributed at the vertex regions where the curvature is the highest. Thus for the first time it is shown that when a monolayer of a homogeneous lipid mixture is bent, the lipid components are partially demixed in reaching the free energy minimum. C1 Rice Univ, Dept Phys & Astron, Houston, TX 77251 USA. European Synchrotron Radiat Facil, F-38043 Grenoble 9, France. Inst Max Von Laue Paul Langevin, F-38042 Grenoble 9, France. Brookhaven Natl Lab, Natl Synchrotron Light Source, Upton, NY 11973 USA. RP Huang, HW (reprint author), Rice Univ, Dept Phys & Astron, Houston, TX 77251 USA. EM hwhuang@rice.edu RI Yang, Lin/D-5872-2013 OI Yang, Lin/0000-0003-1057-9194 FU NCRR NIH HHS [RR14812]; NIGMS NIH HHS [GM55203] NR 28 TC 17 Z9 19 U1 0 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 JAN 4 PY 2005 VL 21 IS 1 BP 203 EP 210 DI 10.1021/la047876u PG 8 WC Chemistry, Multidisciplinary; Chemistry, Physical; Materials Science, Multidisciplinary SC Chemistry; Materials Science GA 886MW UT WOS:000226232700029 PM 15620304 ER PT J AU Gillooly, JF Allen, AP West, GB Brown, JH AF Gillooly, JF Allen, AP West, GB Brown, JH TI The rate of DNA evolution: Effects of body size and temperature on the molecular clock SO PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA LA English DT Article DE mutation; metabolic theory; allometry; substitution ID METAZOAN PHYLA; METABOLIC-RATE; FOSSIL RECORD; TIME; ORIGIN; GENERATION AB Observations that rates of molecular evolution vary widely within and among lineages have cast doubts on the existence of a single "molecular clock." Differences in the timing of evolutionary events estimated from genetic and fossil evidence have raised further questions about the accuracy of molecular clocks. Here, we present a model of nucleotide substitution that combines theory on metabolic rate with the now-classic neutral theory of molecular evolution. The model quantitatively predicts rate heterogeneity and may reconcile differences in molecular- and fossil-estimated dates of evolutionary events. Model predictions are supported by extensive data from mitochondrial and nuclear genomes. By accounting for the effects of body size and temperature on metabolic rate, this model explains heterogeneity in rates of nucleotide substitution in different genes, taxa, and thermal environments. This model also suggests that there is indeed a single molecular clock, as originally proposed by Zuckerkandl and Pauling [Zuckerkandl, E. & Pauling, L. (1965) in Evolving Genes and Proteins, eds. Bryson, V. & Vogel, H. J. (Academic, New York), pp. 97-166], but that it "ticks" at a constant substitution rate per unit of mass-specific metabolic energy rather than per unit of time. This model therefore links energy flux and genetic change. More generally, the model suggests that body size and temperature combine to control the overall rate of evolution through their effects on metabolism. C1 Univ New Mexico, Dept Biol, Albuquerque, NM 87131 USA. Santa Fe Inst, Santa Fe, NM 87501 USA. Los Alamos Natl Lab, Div Theoret Phys, Los Alamos, NM 87545 USA. RP Gillooly, JF (reprint author), Univ New Mexico, Dept Biol, Albuquerque, NM 87131 USA. EM gillooly@unm.edu RI Allen, Andrew/B-8045-2011 OI Allen, Andrew/0000-0003-0304-7544 NR 29 TC 251 Z9 265 U1 2 U2 62 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 JAN 4 PY 2005 VL 102 IS 1 BP 140 EP 145 DI 10.1073/pnas.0407735101 PG 6 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 886HB UT WOS:000226216400026 PM 15618408 ER PT J AU Wolf, D Yamakov, V Phillpot, SR Mukherjee, A Gleiter, H AF Wolf, D Yamakov, V Phillpot, SR Mukherjee, A Gleiter, H TI Deformation of nanocrystalline materials by molecular-dynamics simulation: relationship to experiments? SO ACTA MATERIALIA LA English DT Review ID X-RAY-DIFFRACTION; SEVERE PLASTIC-DEFORMATION; BOUNDARY DIFFUSION CREEP; EMBEDDED-ATOM METHOD; AMORPHOUS INTERGRANULAR FILMS; FINE-GRAINED MATERIALS; STACKING-FAULT ENERGY; HALL-PETCH BEHAVIOR; MECHANICAL-PROPERTIES; NANOSTRUCTURED METAL AB We review the results of recent molecular-dynamics simulations of the structure and deformation behavior of nanocrystalline materials, i.e., polycrystalline materials with a grain size of typically less than about 100 nm. These simulations have now become large enough and sophisticated enough that they are beginning to cover the entire range of grain sizes over which the experimentally suggested transition from a dislocation-based deformation mechanism to one involving GB processes takes place. Their atomic-level resolution provides novel insights into the intricate interplay between the dislocation and GB processes responsible for this cross-over. These simulations also reveal how and why this crossover in the dominant mechanism leads to a transition in the mechanical behavior. However, in spite of these early successes, these simulations are inherently limited to rather idealized model microstructures and extremely high deformation rates. We therefore address the critical question as to the degree to which they begin to capture the experimentally observed. albeit controversial. deformation behavior of real nanocrystalline materials. (Supplementary material to this article, in the form of color graphs of some of the figures and several deformation-simulation movies, can be viewed at http://phillpot.mse.ufl.edu/review.html.) (C) 2004 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved. C1 Argonne Natl Lab, Argonne, IL 60439 USA. Natl Inst Aerosp, Hampton, VA 23666 USA. Univ Florida, Dept Mat Sci & Engn, Gainesville, FL 32611 USA. Univ Calif Davis, Davis, CA 95616 USA. Forschungszentrum Karlsruhe, Inst Nanotechnol, D-76021 Karlsruhe, Germany. RP Argonne Natl Lab, 9700 S Cass Ave, Argonne, IL 60439 USA. EM wolf@anl.gov RI Phillpot, Simon/J-9117-2012; OI Phillpot, Simon/0000-0002-7774-6535 NR 180 TC 443 Z9 449 U1 20 U2 233 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 1359-6454 EI 1873-2453 J9 ACTA MATER JI Acta Mater. PD JAN 3 PY 2005 VL 53 IS 1 BP 1 EP 40 DI 10.1016/j.actamat.2004.08.045 PG 40 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA 879LA UT WOS:000225718100001 ER PT J AU Vitek, JM AF Vitek, JM TI The effect of welding conditions on stray grain formation in single crystal welds - theoretical analysis SO ACTA MATERIALIA LA English DT Article DE laser welding; nickel alloys; single crystal growth; solidification; stray grains ID BASE SUPERALLOY WELDS; ELECTRON-BEAM WELDS; MICROSTRUCTURE; SOLIDIFICATION AB Stray grain formation during solidification of nickel-based single crystal superalloy welds leads to a degradation of mechanical properties and cracking. Based on the mechanism of constitutional supercooling ahead of the advancing dendritic growth front. the effect of welding conditions (weld speed and power) on the tendency to form stray grains, during solidification was evaluated. A simple 3D thermal model was combined with a geometric model to determine the extent of stray grain formation as a function of welding conditions and position in the weld pool, taking into account the influence of dendrite growth orientation. A parameter describing the degree of stray grain formation. averaged over the entire solidification front. was calculated. Processing maps that show the severity of stray grain formation as a function of weld speed, power and orientation were developed. It was; found that low power and high weld speed were optimal for minimizing the stray grain formation potential. The effect of crystallographic orientation of the weld on the overall tendency to form stray grains was minimal, although local variations based or. orientation were quantified. The theoretical analysis was compared to earlier experimental work on laser welded nickel-based single crystal and all of the experimental observations could be reproduced in the calculations. Published by Elsevier Ltd on behalf of Acta Materialia Inc. C1 Oak Ridge Natl Lab, Div Met & Ceram, Oak Ridge, TN 37831 USA. RP Vitek, JM (reprint author), Oak Ridge Natl Lab, Div Met & Ceram, POB 2008, Oak Ridge, TN 37831 USA. EM vitekjm@ornl.gov NR 17 TC 53 Z9 53 U1 4 U2 35 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 1359-6454 J9 ACTA MATER JI Acta Mater. PD JAN 3 PY 2005 VL 53 IS 1 BP 53 EP 67 DI 10.1016/j.actamat.2004.08.039 PG 15 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA 879LA UT WOS:000225718100003 ER PT J AU Bei, H George, EP AF Bei, H George, EP TI Microstructures and mechanical properties of a directionally solidified NiAl-Mo eutectic alloy SO ACTA MATERIALIA LA English DT Article DE intermetallic; NiAl; composite; directional solidification; eutectic microstructure; mechanical property ID INDENTATION EXPERIMENTS; FRACTURE-BEHAVIOR; CR-CR3SI ALLOYS; SINGLE-CRYSTALS; V EUTECTICS; COMPOSITES; LAMELLAR; CR; DUCTILITY; MODULUS AB A NiAl-Mo ternary eutectic alloy, having the nominal composition Ni-45.5Al-9Mo (at.%). was directionally solidified in a high-temperature optical floating zone furnace. Well-aligned rod-like microstructures were obtained, consisting of NiAl matrix and 14% (by volume) continuous Mo fibers having a square cross-section. With increasing growth rate (from 20 to 80 mm/h). the spacing, and size of the Mo fibers decreased. from approximate to2 to 1 mum (fiber spacing) and 800 to 400 nm (fiber size). X-ray microprobe analyse revealed hat the NiAl matrix contained essentially no Mo (<0.1 at.%) and had the composition Ni-45.2Al (at.%). while the composition of the Mo fibers was Mo-10.1Al-3.9Ni (at.%). From electron back-scatter diffraction patterns, the following orientation relationships were obtained: <100>(NiAl)//<100>(Mo), and {011}(NiAl)//{011}(Mo). The growth directions and Mo/NiAl interface boundaries were found to be parallel to <100> and {011}, respectively, in both Mo and NiAl. Nanoindentation was used to probe the mechanical properties of the individual phases in the eutectic microstructure and the modulus and hardness of the NiAl matrix were determined to be 180 and 2.9 GPa, respectively, and those of the Mo fibers 270 and 4.8 GPa. Tensile tests were used to investigate the temperature dependence of the strength and ductility of the composite. Its ductile-to-brittle transition temperature was found to be similar to675 degreesC. and its yield strength about 25-30% higher than that of <100> NiAl single crystals over the temperature range 600-1000 degreesC. (C) 2004 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved. C1 Univ Tennessee, Dept Mat Sci & Engn, Knoxville, TN 37996 USA. Oak Ridge Natl Lab, Div Met & Ceram, Oak Ridge, TN 37831 USA. RP Bei, H (reprint author), Univ Tennessee, Dept Mat Sci & Engn, 434 Dougherty Hall, Knoxville, TN 37996 USA. EM Hbei1@utk.edu; georgeep@ornl.gov RI George, Easo/L-5434-2014; OI Bei, Hongbin/0000-0003-0283-7990 NR 41 TC 124 Z9 128 U1 5 U2 40 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 1359-6454 EI 1873-2453 J9 ACTA MATER JI Acta Mater. PD JAN 3 PY 2005 VL 53 IS 1 BP 69 EP 77 DI 10.1016/j.actamat.2004.09.003 PG 9 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA 879LA UT WOS:000225718100004 ER PT J AU Siegel, DJ Hamilton, JC AF Siegel, DJ Hamilton, JC TI Computational study of carbon segregation and diffusion within a nickel grain boundary SO ACTA MATERIALIA LA English DT Article DE grain boundary segregation; grain boundary diffusion; magnetic properties; nickel alloys; first principles; electron theory ID AB-INITIO; CU; METALS; FILMS; ELECTRODEPOSITION; PSEUDOPOTENTIALS; ALLOYS; ATOMS AB Using density functional theory, we study the segregation and diffusion of carbon interstitials at a nickel Sigma3 (1 1 (2) over bar) tilt grain boundary (GB) as a function of C coverage and Ni magnetic state. We find that segregation is most favorable for a "checkerboard" configuration at a coverage of 1/2 monolayer in both non-magnetic (NM) and ferromagnetic (FM) states, with FM (NM) heats of segregation approaching -0.5 (-0.3) eV per C atom. Segregation is 0.1-0.2 eV stronger in the FM state, because C interstitials suppress Ni magnetism, and this suppression is minimized when C resides at the boundary. Carbon GB diffusion is predicted to be highly anisotropic: calculated energy barriers (E-a) for migration parallel to the [1 (1) over bar 0] tilt axis are significantly smaller (E-a = 0.44-0.77 eV) than for lattice diffusion (E-a = 1.62 eV), while barriers perpendicular to [1 (1) over bar 0] are comparable to those of lattice diffusion. Changes in barrier height due to Ni magnetism are (with one exception) relatively small, and are evident only when the diffusion pathway bisects highly compressed GB sites. (C) 2004 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved. C1 Sandia Natl Labs, Dept Mat Phys, Livermore, CA 94551 USA. RP USN, Res Lab, Ctr Computat Mat Sci, Code 6390,4555 Overlook Ave SW, Washington, DC 20375 USA. EM dsiegel@dave.nrl.navy.mil RI Siegel, Donald/B-4048-2013 OI Siegel, Donald/0000-0001-7913-2513 NR 47 TC 19 Z9 20 U1 7 U2 23 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 1359-6454 EI 1873-2453 J9 ACTA MATER JI Acta Mater. PD JAN 3 PY 2005 VL 53 IS 1 BP 87 EP 96 DI 10.1016/j.actamat.2004.09.006 PG 10 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA 879LA UT WOS:000225718100006 ER PT J AU Misra, A Zhang, X Hammon, D Hoagland, RG AF Misra, A Zhang, X Hammon, D Hoagland, RG TI Work hardening in rolled nanolayered metallic composites SO ACTA MATERIALIA LA English DT Article ID STRAINED EPITAXIAL LAYER; HIGH-TENSILE DUCTILITY; NANOCRYSTALLINE COPPER; NANOSTRUCTURED METAL; MISFIT DISLOCATIONS; THIN-FILMS; MULTILAYERS; DEFORMATION; MECHANISMS; BEHAVIOR AB The strength of room temperature rolled sputter deposited nanolayered Cu-Nb composites is evaluated. Self-supported Cu-Nb foils with initial individual layer thickness varying from 32 to 75 nm were rolled to the same final layer thickness of 30 nm. Nanoindentation hardness measurements were used to study the change in hardness with rolling strain. The resulting, work hardening, is compared to bulk Cu and mechanisms that give rise to work hardening in nanolayered metals. in the absence of dislocation cell structure formation. are discussed. (C) 2004 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved. C1 Los Alamos Natl Lab, Div Mat Sci & Technol, Los Alamos, NM 87545 USA. RP Misra, A (reprint author), Los Alamos Natl Lab, Div Mat Sci & Technol, MS G755, Los Alamos, NM 87545 USA. EM amisra@lanl.gov RI Hoagland, Richard/G-9821-2012; Misra, Amit/H-1087-2012; Zhang, Xinghang/H-6764-2013 OI Zhang, Xinghang/0000-0002-8380-8667 NR 34 TC 69 Z9 73 U1 4 U2 32 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 1359-6454 J9 ACTA MATER JI Acta Mater. PD JAN 3 PY 2005 VL 53 IS 1 BP 221 EP 226 DI 10.1016/j.actamat.2004.09.018 PG 6 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA 879LA UT WOS:000225718100018 ER PT J AU Rodriguez, BJ Nemanich, RJ Kingon, A Gruverman, A Kalinin, SV Terabe, K Liu, XY Kitamura, K AF Rodriguez, BJ Nemanich, RJ Kingon, A Gruverman, A Kalinin, SV Terabe, K Liu, XY Kitamura, K TI Domain growth kinetics in lithium niobate single crystals studied by piezoresponse force microscopy SO APPLIED PHYSICS LETTERS LA English DT Article ID FERROELECTRIC DOMAIN; LINBO3; LITAO3; WALLS AB The kinetics of sidewise domain growth in an inhomogeneous electric field has been investigated in stoichiometric LiNbO3 single crystals by measuring the lateral domain size as a function of the voltage pulse magnitude and duration using piezoresponse force microscopy. The domain size increases linearly with the voltage magnitude suggesting that the domain size is kinetically limited in a wide range of pulse magnitudes and durations. In spite of that, the written domains exhibit strong retention behavior. It is suggested that the switching behavior can be described by the universal scaling curve. Domain kinetics can be described as an activation process by calculating the field distribution using the charged sphere model under the assumption of an exponential field dependence of the wall velocity. The activation energy is found to be a function of the external field. (C) 2005 American Institute of Physics. C1 N Carolina State Univ, Dept Phys, Raleigh, NC 27695 USA. N Carolina State Univ, Dept Mat Sci, Raleigh, NC 27695 USA. Oak Ridge Natl Lab, Condensed Matter Sci Div, Oak Ridge, TN 37831 USA. Natl Inst Mat Sci & Technol NIMS, Tsukuba, Ibaraki 3050044, Japan. RP N Carolina State Univ, Dept Phys, Raleigh, NC 27695 USA. EM alexei_gruverman@ncsu.edu RI Liu, Xiaoyan/H-5741-2011; Kalinin, Sergei/I-9096-2012; Rodriguez, Brian/A-6253-2009; Gruverman, alexei/P-3537-2014 OI Kalinin, Sergei/0000-0001-5354-6152; Rodriguez, Brian/0000-0001-9419-2717; Gruverman, alexei/0000-0003-0492-2750 NR 19 TC 124 Z9 124 U1 3 U2 48 PU AMER INST PHYSICS PI MELVILLE PA 1305 WALT WHITMAN RD, STE 300, MELVILLE, NY 11747-4501 USA SN 0003-6951 EI 1077-3118 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD JAN 3 PY 2005 VL 86 IS 1 AR 012906 DI 10.1063/1.1845594 PG 3 WC Physics, Applied SC Physics GA 893ED UT WOS:000226701200071 ER PT J AU Tok, JBH Bi, LR AF Tok, JBH Bi, LR TI A comparative binding study of BIV Tat peptide against its TAR RNA duplex, RNA-DNA heteroduplex and DNA duplex SO BIOORGANIC & MEDICINAL CHEMISTRY LETTERS LA English DT Article DE peptides; fluorescence; nucleic acids; circular dichroism; DNA melt ID RIBOSOMAL-RNA; AMINOGLYCOSIDE ANTIBIOTICS; CIRCULAR-DICHROISM; SMALL MOLECULES; COMPLEX; LIGANDS; STABILIZATION; CONFORMATION; ACTIVATOR; CONSTRUCT AB Association between RNA and DNA strands to form RNA-DNA heteroduplex is important in many biological processes such as transcription. DNA replication and reverse transcription. Herein, binding affinities of a 17-mer BIV Tat peptide is compared with TAR DNA duplex. TAR RNA-DNA heteroduplex and TAR RNA duplex. It was observed that binding affinities of Tat peptide is comparable against DNA-RNA heteroduplex and RNA duplex, whereas DNA duplex binding is decidedly poor. (C) 2004 Published by Elsevier Ltd. C1 CUNY York Coll, Dept Chem, Jamaica, NY 11451 USA. CUNY, Grad Ctr, Jamaica, NY 11451 USA. RP Tok, JBH (reprint author), Lawrence Livermore Natl Lab, Chem & Mat Sci Directorate, 7000 East Ave,L-234, Stanford, CA 94305 USA. EM tok2@llnl.gov FU NIGMS NIH HHS [GM 08153-26] NR 35 TC 0 Z9 0 U1 1 U2 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0960-894X J9 BIOORG MED CHEM LETT JI Bioorg. Med. Chem. Lett. PD JAN 3 PY 2005 VL 15 IS 1 BP 129 EP 133 DI 10.1016/j.bmcl.2004.10.030 PG 5 WC Chemistry, Medicinal; Chemistry, Organic SC Pharmacology & Pharmacy; Chemistry GA 880FE UT WOS:000225773600024 PM 15582425 ER PT J AU Dilustro, JJ Collins, B Duncan, L Crawford, C AF Dilustro, JJ Collins, B Duncan, L Crawford, C TI Moisture and soil texture effects on Soil CO2 efflux components in southeastern mixed pine forests SO FOREST ECOLOGY AND MANAGEMENT LA English DT Article DE soil CO2 efflux; soil respiration; mixed pine; soil temperature; microbial biomass carbon ID FINE-ROOT PRODUCTION; MICROBIAL BIOMASS; RESPIRATION; PLANTATIONS; CARBON; TEMPERATURE; AVAILABILITY; DEPENDENCE; ECOSYSTEM; GRADIENT AB Monitoring soil CO2 efflux rates and identifying controlling factors, such as forest composition or soil texture, can help guide forest management and will likely gain relevance as atmospheric CO2 continues to increase. We examined soil CO2 efflux and potential controlling factors in managed mixed pine forests in southwestern Georgia. Soil CO2 efflux was monitored periodically in two stands that differed in soil texture in 2001 and 2002, and in six additional stands in 2003. We also monitored controlling factors: soil temperature, moisture, organic layer mass, and A layer depth. Soil moisture and CO2 efflux varied with soil texture differences among the stands. As expected, soil temperature had a strong influence on soil CO2 efflux. Soil moisture, organic layer mass, and A layer depth also were correlated with soil CO2 efflux during periods of water stress, but these relationships differed with soil texture. Forest management activities can alter components of soil CO2 efflux, including soil carbon pools, temperature, and moisture; understanding the underlying variation of these components and resultant CO2 efflux over soil types can help guide management toward desired forest carbon balance trends in southeastern mixed pine forests. (C) 2004 Elsevier B.V. All rights reserved. C1 Univ Georgia, Savannah River Ecol Lab, Aiken, SC 29802 USA. RP Dilustro, JJ (reprint author), Univ Georgia, Savannah River Ecol Lab, Drawer E, Aiken, SC 29802 USA. EM dilustro@srel.edu NR 35 TC 47 Z9 76 U1 1 U2 22 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0378-1127 J9 FOREST ECOL MANAG JI For. Ecol. Manage. PD JAN 3 PY 2005 VL 204 IS 1 BP 85 EP 95 DI 10.1016/j.foreco.2004.09.001 PG 11 WC Forestry SC Forestry GA 886VY UT WOS:000226262200007 ER PT J AU Nagarajan, R Xu, Z Edgar, JH Baig, F Chaudhuri, J Rek, Z Payzant, EA Meyer, HM Pomeroy, J Kuball, M AF Nagarajan, R Xu, Z Edgar, JH Baig, F Chaudhuri, J Rek, Z Payzant, EA Meyer, HM Pomeroy, J Kuball, M TI Crystal growth of B12As2 on SiC substrate by CVD method SO JOURNAL OF CRYSTAL GROWTH LA English DT Article DE characterization; crystal growth; chemical vapor deposition processes ID CHEMICAL-VAPOR-DEPOSITION; BORON PHOSPHIDE; THIN-FILMS; BP; SYSTEM AB The growth of B12As2 by chemical vapor deposition on 6H-SiC substrates using hydrides B2H6 and AsH3 as the reactants is described. The growth rate increased from 1.5 mum/h at 1100degreesC to a maximum of 5mum/h at 1400degreesC, and decreased at higher temperatures. X-ray diffraction indicates that the deposits were amorphous when the deposition temperature was below 1150degreesC. Strongly c-axis oriented crystalline B12As2, films were obtained at temperatures higher than 1150degreesC. The orientation relationship of the B12As2 on 6H-SiC was (0001)<10 (1) over bar0>parallel to(0001)<11 (2) over bar0>. The surface morphology of the B12As2, film grown at 1150degreesC consisted of isolated triangular crystallites. A continuous film forms as the arowth temperature is progressively increased up to 1450degreesC. (C) 2004 Elsevier B.V. All rights reserved. C1 Kansas State Univ, Dept Chem Engn, Manhattan, KS 66506 USA. Wichita State Univ, Dept Mech Engn, Wichita, KS 67260 USA. Stanford Synchrotron Radiat Lab, Stanford, CA 94305 USA. Oak Ridge Natl Lab, High Temp Mat Lab, Oak Ridge, TN 37831 USA. Univ Bristol, HH Wills Phys Lab, Bristol BS8 1TL, Avon, England. RP Nagarajan, R (reprint author), Kansas State Univ, Dept Chem Engn, 105 Durland Hall, Manhattan, KS 66506 USA. EM raj@ksu.edu RI Payzant, Edward/B-5449-2009; Chaudhuri, Jharna/E-8863-2013 OI Payzant, Edward/0000-0002-3447-2060; NR 28 TC 17 Z9 17 U1 0 U2 7 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-0248 J9 J CRYST GROWTH JI J. Cryst. Growth PD JAN 3 PY 2005 VL 273 IS 3-4 BP 431 EP 438 DI 10.1016/j.jcrysgro.2004.07.068 PG 8 WC Crystallography; Materials Science, Multidisciplinary; Physics, Applied SC Crystallography; Materials Science; Physics GA 886QJ UT WOS:000226243100014 ER PT J AU Martinez-Inesta, MM Peral, I Proffen, T Lobo, RF AF Martinez-Inesta, MM Peral, I Proffen, T Lobo, RF TI A pair distribution function analysis of zeolite beta SO MICROPOROUS AND MESOPOROUS MATERIALS LA English DT Article DE zeolite beta; pair distribution function; stacking faults; disorder; structure refinement ID MOLECULAR-SIEVES; DIFFRACTION; REFINEMENT; FAUJASITE; PROGRAM; CONNECTIVITY; SIMULATIONS; SEGREGATION; MIXTURES; TOPOLOGY AB We describe the structural refinement of zeolite beta using the local structure obtained with the pair distribution function (PDF) method. A high quality synchrotron and two neutron scattering datasets were obtained on two samples of siliceous zeolite beta. The two polytypes that make up zeolite beta have the same local structure; therefore refinement of the two structures was possible using the same experimental PDF. Optimized structures of polytypes A and B were used to refine the structures using the program PDFfit. Refinements using only the synchrotron or the neutron datasets gave results inconsistent with each other but a cyclic refinement with the two datasets gave a good fit to both PDFs. The results show that the PDF method is a viable technique to analyze the local structure of disordered zeolites. However, given the complexity of most zeolite frameworks, the use of both X-ray and neutron radiation and high-resolution patterns is essential to obtain reliable refinements. (C) 2004 Elsevier Inc. All rights reserved. C1 Univ Delaware, Ctr Catalyt Sci & Technol, Dept Chem Engn, Newark, DE 19716 USA. Los Alamos Natl Lab, Manuel Lujan Jr Neutron Scattering Ctr, Los Alamos Neutron Scattering Ctr, Los Alamos, NM 87545 USA. RP Martinez-Inesta, MM (reprint author), Univ Delaware, Ctr Catalyt Sci & Technol, Dept Chem Engn, 150 Acad St,315 Colburn Lab, Newark, DE 19716 USA. EM martinm@che.udel.edu; lobo@che.udel.edu RI Lujan Center, LANL/G-4896-2012; Proffen, Thomas/B-3585-2009; Peral Alonso, Inmaculada/P-5298-2016; OI Proffen, Thomas/0000-0002-1408-6031; Peral Alonso, Inmaculada/0000-0002-6994-1277; Lobo, Raul/0000-0003-4027-3129 NR 43 TC 22 Z9 22 U1 2 U2 21 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 JAN 3 PY 2005 VL 77 IS 1 BP 55 EP 66 DI 10.1016/j.micromeso.2004.07.040 PG 12 WC Chemistry, Applied; Chemistry, Physical; Nanoscience & Nanotechnology; Materials Science, Multidisciplinary SC Chemistry; Science & Technology - Other Topics; Materials Science GA 878NB UT WOS:000225652400003 ER PT J AU Hurth, T Lunghi, E Porod, W AF Hurth, T Lunghi, E Porod, W TI Untagged (B)over-bar -> Xs+d gamma CP asymmetry as a probe for new physics SO NUCLEAR PHYSICS B LA English DT Article ID SUPERSYMMETRIC STANDARD MODEL; TO-LEADING ORDER; RENORMALIZATION-GROUP EQUATIONS; EFFECTIVE GAUGE-THEORIES; HIGGS-BOSON MASSES; RADIATIVE B-DECAYS; X-S-GAMMA; 2-LOOP CORRECTIONS; INCLUSIVE DECAY; MESON DECAY AB The direct CP asymmetry in the untagged inclusive channel (B) over bar --> X(s+d)gamma provides a strict test of the standard model. It has been shown beyond the partonic level that this asymmetry is negligibly small thanks to U-spin relations and to the unitarity of the CKM matrix. In the present paper we investigate this relation beyond the SM; in particular, we analyse to which extent deviations from this prediction are possible in supersymmetric scenarios. We analyse the minimal flavour violation scenario, including tan beta-enhanced terms and using the complete two-loop renormalization group running. Our analysis fully takes into account also the EDM constraints on the supersymmetric phases. We also investigate possible correlations between the tagged and the untagged CP asymmetries and the indirect sensitivity of the latter to the (B) over bar --> X(d)gamma CP asymmetry. Furthermore, we derive general model-independent formulae for the branching ratios and CP asymmetries for the inclusive (B) over bar --> X(s)gamma and (B) over bar --> X(s)gamma modes, and update the corresponding SM predictions. We obtain for a photon energy cut-off E-0 = 1.6 GeV: B[(B) over bar --> X(s)gamma] = (3.61(-0.40)(0.24)\(mc/mb) +/- 0.02(CKM) +/- 0.24(param.) +/- 0.14(scale)) x 10(-4), A(CP)[(B) over bar --> X(s)gamma] = (0.42(-0.08)(+0.08)\(mc/mb) +/- 0.03(CKM-0.08)(0.15)\(scale))%. (C) 2004 Elsevier B.V. All rights reserved. C1 CERN, Div Phys Theor, CH-1211 Geneva 23, Switzerland. Stanford Univ, Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. Univ Zurich, Inst Theoret Phys, CH-8057 Zurich, Switzerland. RP Lunghi, E (reprint author), CERN, Div Phys Theor, CH-1211 Geneva 23, Switzerland. EM lunghi@physik.unizh.ch NR 76 TC 94 Z9 94 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0550-3213 EI 1873-1562 J9 NUCL PHYS B JI Nucl. Phys. B PD JAN 3 PY 2005 VL 704 IS 1-2 BP 56 EP 74 DI 10.1016/j.nuclphysb.2004.10.024 PG 19 WC Physics, Particles & Fields SC Physics GA 886HO UT WOS:000226217700002 ER PT J AU Alexander, S Becker, K Becker, M Dasgupta, K Knauf, A Tatar, R AF Alexander, S Becker, K Becker, M Dasgupta, K Knauf, A Tatar, R TI In the realm of the geometric transitions SO NUCLEAR PHYSICS B LA English DT Article ID DIMENSIONAL STRING COMPACTIFICATIONS; YANG-MILLS THEORY; PROBING F-THEORY; MATRIX MODELS; LARGE N; MIRROR SYMMETRY; GRAVITATIONAL COUPLINGS; TOPOLOGICAL STRINGS; SIGMA-MODELS; O-PLANES AB We complete the duality cycle by constructing the geometric transition duals in the type IIB, type I and heterotic theories. We show that in the type IIB theory the background on the closed string side is a Kahler deformed conifold. as expected. even though the mirror type IIA backgrounds are non-Kahler (both before and after the transition). On the other hand, the type I and heterotic backgrounds are non-Kahler. Therefore, on the heterotic side these backgrounds give rise to new torsional manifolds that have not been studied before. We show the consistency of these backgrounds by verifying the torsional equation. (C) 2004 Elsevier B.V. All rights reserved. C1 Stanford Univ, Dept Phys, Stanford, CA 94305 USA. Stanford Univ, Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. Univ Utah, Dept Phys, Salt Lake City, UT 84112 USA. Univ Maryland, Dept Phys, College Pk, MD 20742 USA. Univ Hamburg, Inst Theoret Phys 2, D-22761 Hamburg, Germany. LBL Berkeley, Theoret Phys Grp, Berkeley, CA 94720 USA. RP Alexander, S (reprint author), Stanford Univ, Dept Phys, Stanford, CA 94305 USA. EM stephon@itp.stanford.edu; katrin@physics.utah.edu; melanieb@physics.umd.edu; keshav@itp.stanford.edu; anke@umd.edu; rtatar@socrates.berkeley.edu NR 98 TC 33 Z9 33 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0550-3213 J9 NUCL PHYS B JI Nucl. Phys. B PD JAN 3 PY 2005 VL 704 IS 1-2 BP 231 EP 278 DI 10.1016/j.nuclphysb.2004.10.036 PG 48 WC Physics, Particles & Fields SC Physics GA 886HO UT WOS:000226217700008 ER PT J AU Raebiger, JW DuBois, DL AF Raebiger, JW DuBois, DL TI Thermodynamic studies of HRh(depx)(2) and [(H)(2)Rh(depx)(2)](CF3SO3): Relationships between five-coordinate monohydrides and six-coordinate dihydrides SO ORGANOMETALLICS LA English DT Article ID HYDRIDE DONOR ABILITIES; TRANSITION-METAL COMPLEXES; BITE ANGLE; HETEROLYTIC CLEAVAGE; RH-RH; BOND; HYDROGEN; PROTON; NI; DIPHOSPHINES AB Four new rhodium complexes, [Rh(depx)(2)](CF3SO3), [(H)(2)Rh(depx)(2)](CF3SO3),[HRh(dePX)(2)(CH3CN)](CF3SO3)(2), and HRh(depx)(2) (where depx = alpha,alpha'-bis(diethylphosphino)xylene), have been synthesized and characterized. The pK(a) values of [(H)(2)Rh(depx)(2)](+) (30.6 +/- 0.3) and [HRh(depx)(2)(CH3CN)](2+) (11.5 +/- 0.4) in acetonitrile were determined by equilibrium reactions with appropriate bases. The hydride donor ability of [(H)(2)Rh(depx)(2)](+) (71.6 +/- 1.0 kcal/mol) was determined by the heterolytic cleavage of hydrogen by [HRh(depx)(2)(CH3CN)](2+) to form [(H)(2)Rh(depx)(2)](+) in the presence of thioacetamide or benzamide. These equilibrium measurements, the half-wave potentials for the Rh(+1/0) and Rh(0/-1) couples of [Rh(depx)(2)](+), and the reversible one-electron oxidation of HRh(depx)(2) (all measured at 22 +/- 1.5 degreesC) were used to establish nine heterolytic and homolytic bond-dissociation free energies in acetonitrile. From these relationships, and those established previously for analogous cobalt and platinum complexes, we conclude that the homolytic bond-dissociation free energies of six-coordinate dihydride species are approximately 2 kcal/mol less than those of the corresponding five-coordinate monohydride species derived by deprotonation. Similarly, the pK(a) values of six-coordinate dihydride complexes are approximately 2 units lower than the corresponding five-coordinate species formally derived by homolytic bond cleavage. C1 Natl Renewable Energy Lab, Golden, CO 80401 USA. RP DuBois, DL (reprint author), Natl Renewable Energy Lab, 1617 Cole Blvd, Golden, CO 80401 USA. EM dan_dubois@nrel.gov NR 33 TC 37 Z9 37 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0276-7333 J9 ORGANOMETALLICS JI Organometallics PD JAN 3 PY 2005 VL 24 IS 1 BP 110 EP 118 DI 10.1021/om049437w PG 9 WC Chemistry, Inorganic & Nuclear; Chemistry, Organic SC Chemistry GA 884GK UT WOS:000226072600018 ER PT J AU Gibson, JK Haire, RG AF Gibson, JK Haire, RG TI Activation of pentamethylcyclopentadiene by Bk+, Cf+ and Es+ ions in the gas phase: Probing electronic structures of transcurium actinides SO ORGANOMETALLICS LA English DT Article ID HYDROCARBON ACTIVATION; LANTHANIDE CATIONS; ORGANOMETALLIC CHEMISTRY; METAL; REACTIVITY; COMPLEXES; URANIUM; CALIFORNIUM; CHARACTER; ENERGIES AB Reactions of monopositive actinide ions, An(+), and lanthanide ions, Ln(+), with 1,2,3,4,5-pentamethylcyclopentadiene, HCp*, were studied by mass spectrometry. This was the first study of the M+/HCp* reaction for M+ = Cm+, Cf+, and Es+; results for M+ = Am+, Bk+, Pr+, Eu+, and Tm+ are compared with those from previous studies. Different product distributions for the present experiments versus previous results for the same reactions are traced to a pressure effect whereby higher reactant pressures favor certain reaction channels. Each of the eight metal ions, M+, reacted with HCp* to produce [MCp*](+) (+ H), as well as additional products. Both Cf+ and Es+ have previously been found to be inert toward most alkenes, but efficiently reacted with HCp* to induce (1) H-loss and [AnCp*](+); (2) H-2-loss and [AnC(5)(CH3)(4)(CH2)](+); and (3) CH3-loss and [AnC(5)(CH3)(4)H](+) (An = Cf, Es). These are the first organoeinsteinium complexes derived from activation of an organic substrate. The exhibited types of reactivity, i.e., product distributions, for the studied ions correlate with the energies to excite the ground-state atomic ions to configurations with two non-f valence electrons. It is concluded that the unidentified lowest-lying [Rn]5f(5)6d7s configuration of Cf+ is similar to2.5 eV above the [Rn]5P(5)7s ground-state configuration. Secondary products included [MCP*(2)](+) (M = Am, Cm, Bk, Cf, Es, Tm, and Pr), the compositions of which correspond to the metallocene sandwich complexes. C1 Oak Ridge Natl Lab, Div Chem Sci, Oak Ridge, TN 37831 USA. RP Gibson, JK (reprint author), Oak Ridge Natl Lab, Div Chem Sci, Oak Ridge, TN 37831 USA. EM gibsonjk@ornl.gov NR 37 TC 7 Z9 7 U1 1 U2 11 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0276-7333 J9 ORGANOMETALLICS JI Organometallics PD JAN 3 PY 2005 VL 24 IS 1 BP 119 EP 126 DI 10.1021/om049387v PG 8 WC Chemistry, Inorganic & Nuclear; Chemistry, Organic SC Chemistry GA 884GK UT WOS:000226072600019 ER PT J AU Breault, RW Ludlow, CJ Yue, PC AF Breault, RW Ludlow, CJ Yue, PC TI Cluster particle number and granular temperature for cork particles at the wall in the riser of a CFB SO POWDER TECHNOLOGY LA English DT Article DE clusters; granular temperature; CFB AB Operating conditions within a circulating fluidized bed (CFB) many times results in the grouping of circulating particles into clusters. Because of their different relative motion with respect to the balance of the flow, these clusters are believed to demonstrate different transport properties when compared to the balance of the particles. To investigate these differences, it is first necessary to have an objective means of identifying those particles that are within a cluster and those that are not. The concept of granular temperature is used to make this distinction. Using laser Doppler velocimetry (LDV) data for 800-mum cork particles, it has been found that groupings of six or more particles demonstrate a different distribution of granular temperatures than groupings with fewer particles. Based on this fact, it is concluded that groups of six particles as measured in the axial flow direction are the fewest number which can be still considered to be in a cluster for this bed material. Additionally, particles considered to be in the dispersed phase have granular temperatures which are low at low solids concentrations, again low at very high solids concentrations and pass through a maximum at intermediate values of solids flow and gas flow. Published by Elsevier B.V. C1 US DOE, NETL Inst, Morgantown, WV 26507 USA. RP Breault, RW (reprint author), US DOE, NETL Inst, 3610 Collins Ferry Rd, Morgantown, WV 26507 USA. EM Ronald.Breault@NETL.DOE.GOV OI Breault, Ronald/0000-0002-5552-4050 NR 13 TC 27 Z9 28 U1 1 U2 11 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0032-5910 J9 POWDER TECHNOL JI Powder Technol. PD JAN 3 PY 2005 VL 149 IS 2-3 BP 68 EP 77 DI 10.1016/j.powtec.2004.11.003 PG 10 WC Engineering, Chemical SC Engineering GA 896KJ UT WOS:000226932700003 ER PT J AU Ye, XR Wai, CM Lin, YH Young, JS Engelhard, MH AF Ye, XR Wai, CM Lin, YH Young, JS Engelhard, MH TI Supercritical fluid immersion deposition: a new process for selective deposition of metal films on silicon substrates SO SURFACE & COATINGS TECHNOLOGY LA English DT Article DE supercritical CO2; immersion deposition; palladium; copper; silicon substrates; palladium silicide ID CHEMICAL-VAPOR-DEPOSITION; CARBON-DIOXIDE SOLUTION; ETCHED POROUS SILICON; ELECTROLESS DEPOSITION; N-SI(111)-H ELECTRODES; REACTIVE DEPOSITION; COPPER DEPOSITION; NICKEL FILMS; X-RAY; PALLADIUM AB Supercritical CO2 is used as a new solvent for immersion deposition, a galvanic displacement process traditionally carried out in aqueous HF solutions containing metal ions, to selectively develop metal films on silicon substrates. Components of supercritical fluid immersion deposition (SFID) solutions for fabricating Cu and Pd films on silicon substrates are described along with the corresponding experimental setup and procedures. Through this method, only silicon surfaces exposed to SFID solutions can be coated. The highly pressurized and gas-like supercritical CO2, combined with the galvanic displacement property of immersion deposition, enables the SFID technique to deposit metal films selectively in small features. Annealing of thin palladium films deposited by SFID can lead to the formation of palladium silicide in small features on silicon substrates. (C) 2004 Elsevier B.V. All rights reserved. C1 Univ Idaho, Dept Chem, Moscow, ID 83844 USA. Pacific NW Natl Lab, Environm Mol Sci Lab, Richland, WA 99352 USA. RP Wai, CM (reprint author), Univ Idaho, Dept Chem, POB 442343, Moscow, ID 83844 USA. EM cwai@uidaho.edu; yuehe.lin@pnl.gov RI Engelhard, Mark/F-1317-2010; Lin, Yuehe/D-9762-2011; OI Lin, Yuehe/0000-0003-3791-7587; Engelhard, Mark/0000-0002-5543-0812 NR 57 TC 13 Z9 18 U1 0 U2 10 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0257-8972 J9 SURF COAT TECH JI Surf. Coat. Technol. PD JAN 3 PY 2005 VL 190 IS 1 BP 25 EP 31 DI 10.1016/j.surfcoat.2004.06.023 PG 7 WC Materials Science, Coatings & Films; Physics, Applied SC Materials Science; Physics GA 873TZ UT WOS:000225305300004 ER PT J AU Hellgren, N Guo, JH Luo, Y Sathe, C Agui, A Kashtanov, S Nordgren, J Agren, H Sundgren, JE AF Hellgren, N Guo, JH Luo, Y Sathe, C Agui, A Kashtanov, S Nordgren, J Agren, H Sundgren, JE TI Electronic structure of carbon nitride thin films studied by X-ray spectroscopy techniques SO THIN SOLID FILMS LA English DT Article DE X-ray spectroscopy; carbon nitride; thin film ID ABSORPTION FINE-STRUCTURE; NEAR-EDGE; HIGH-RESOLUTION; PHOTOELECTRON-SPECTROSCOPY; HARDENING MECHANISMS; THERMAL-STABILITY; BONDING STRUCTURE; BINDING-ENERGIES; CNX FILMS; SPECTRA AB Magnetron-sputtered carbon nitride thin films with different structures and compositions were analyzed by X-ray and ultraviolet photoelectron spectroscopy (XPS and UPS), near-edge X-ray absorption fine structure spectroscopy (NEXAFS), as well as X-ray emission spectroscopy (XES). In all techniques, the carbon spectra are broad and featureless with little variation depending on growth conditions. The nitrogen spectra, on the other hand, show more distinct features, providing a powerful tool for structural characterization. By comparing the experimental spectra with calculations on different model systems, we are able to identify three major bonding structures of the nitrogen-N1: nitrile (C equivalent to N) bonds; N2: Pyridine-like N, i.e., N bonded to two C atoms; and N3: graphite-like N, i.e., N bonded to three C atoms as if substituted in a graphitic network, however, possibly positioned in a pentagon and/or with sp(3) carbon neighbors. The presence of N2 and N3 are best detected by XPS, while N1 is better detected by NEXAFS. The calculated XES spectra also give good indications how valence band spectra should be interpreted. Films grown at the higher temperatures ( greater than or equal to 350 degreesC) show a pronounced angular dependence of the incoming photon beam in NEXATS measurements, which suggests a textured microstructure with standing graphitic basal planes, while amorphous films grown at low temperatures show isotropic properties. (C) 2004 Elsevier B.V. All rights reserved. C1 Linkoping Univ, Dept Phys, Thin Film Phys Div, S-58183 Linkoping, Sweden. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. Royal Inst Technol, S-10691 Stockholm, Sweden. Univ Uppsala, Dept Phys, S-75121 Uppsala, Sweden. RP Hellgren, N (reprint author), Intel Corp, Portland Technol Dev, RA3-301,5200 NE Elam Young Pkwy, Hillsboro, OR 97124 USA. EM niklas.hellgren@intel.com RI Luo, Yi/B-1449-2009; Agren, Hans/H-7715-2016; Sathe, Conny/P-8139-2016 OI Luo, Yi/0000-0003-0007-0394; Sathe, Conny/0000-0001-7799-8575 NR 70 TC 97 Z9 99 U1 4 U2 49 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0040-6090 J9 THIN SOLID FILMS JI Thin Solid Films PD JAN 3 PY 2005 VL 471 IS 1-2 BP 19 EP 34 DI 10.1016/j.tsf.2004.03.027 PG 16 WC Materials Science, Multidisciplinary; Materials Science, Coatings & Films; Physics, Applied; Physics, Condensed Matter SC Materials Science; Physics GA 879NM UT WOS:000225724500003 ER PT J AU Kundu, S Olsen, LC AF Kundu, S Olsen, LC TI Chemical bath deposited zinc sulfide buffer layers for copper indium gallium sulfur-selenide solar cells and device analysis SO THIN SOLID FILMS LA English DT Article DE solar cells; X-ray photoelectron spectroscopy; ZnS; quantum efficiency ID ACID DISSOCIATION-CONSTANT; THIN-FILMS; MEDIA; H2S AB Cadmium-five copper indium gallium sulfur-selenide (CIGSS) thin film solar cells have been fabricated using chemical bath deposited (CBD) zinc sulfide (ZnS) buffer layers. Shell Solar Industries provided high quality CIGSS absorber layers. The use of CBD-ZnS, which is a higher band gap material than CdS, improved the quantum efficiency of fabricated cells at lower wavelengths, leading to an increase in short circuit current. The best cell to date yielded an active area (0.43 cm(2)) efficiency of 13.3%. The effect of the ZnS buffer layer thickness on device performance was studied carefully. This paper also presents a discussion of issues relevant to the use of the CBD-ZnS buffer material for improving device performance. (C) 2004 Elsevier B.V. All rights reserved. C1 Pacific NW Natl Lab, Phys Vapor Deposit Grp, Richland, WA 99352 USA. RP Kundu, S (reprint author), Pacific NW Natl Lab, Phys Vapor Deposit Grp, POB 999,MS K3-59, Richland, WA 99352 USA. EM Sambhu.kundu@pnl.gov NR 25 TC 26 Z9 31 U1 0 U2 20 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0040-6090 J9 THIN SOLID FILMS JI Thin Solid Films PD JAN 3 PY 2005 VL 471 IS 1-2 BP 298 EP 303 DI 10.1016/j.tsf.2004.05.127 PG 6 WC Materials Science, Multidisciplinary; Materials Science, Coatings & Films; Physics, Applied; Physics, Condensed Matter SC Materials Science; Physics GA 879NM UT WOS:000225724500046 ER PT J AU Tebbs, RS Hinz, JM Yamada, NA Wilson, JB Salazar, EP Thomas, CB Jones, IM Jones, NJ Thompson, LH AF Tebbs, RS Hinz, JM Yamada, NA Wilson, JB Salazar, EP Thomas, CB Jones, IM Jones, NJ Thompson, LH TI New insights into the Fanconi anemia pathway from an isogenic FancG hamster CHO mutant SO DNA REPAIR LA English DT Article DE FancG; Fanconi anemia; replication fork; Rad51 foci; homologous recombination ID STRAND BREAK REPAIR; DNA-DAMAGING AGENTS; HOMOLOGOUS RECOMBINATION; COMPLEMENTATION GROUP; NUCLEAR-COMPLEX; MITOMYCIN-C; CHROMOSOMAL INSTABILITY; SENSITIVE MUTANTS; DIVERSE MUTAGENS; PROTEINS FANCA AB The Fanconi anemia (FA) proteins overlap with those of homologous recombination through FANCD1/BRCA2, but the biochemical functions of other FA proteins are largely unknown. By constructing and characterizing a null fancg mutant (KO40) of hamster CHO cells, we show that FancG protects cells against a broad spectrum of genotoxic agents. KO40 is consistently hypersensitive to both alkylating agents that produce monoadducts and those that produce interstrand crosslinks. KO40 cells were no more sensitive to mitomycin C (3x) and diepoxybutane (2x) than to 6-thioguanine (5x), ethylnitrosourea (3x), or methyl methanesulfonate (MMS) (3x). These results-contrast with the pattern of selective sensitivity to DNA crosslinking agents seen historically with cell lines from FA patients. The hypersensitivity of KO40 to MMS was not associated with a higher level of initial DNA single-strand breaks; nor was there a defect in removing MNU-induced methyl groups from DNA. Both control and MMS-treated synchronized G1-phase KO40 cells progressed through S phase at a normal rate but showed a lengthening of G2 phase compared with wild type. MMS-treated and untreated early S-phase KO40 cells had increased levels of Rad51 foci compared with wild type. Asynchronous KO40 treated with ionizing radiation (IR) exhibited a normal Rad51 focus response, consistent with KO40 having only slight sensitivity to killing by IR. The plating efficiency and doubling time of KO40 cells were nearly normal, and they showed no increase in spontaneous chromosomal aberrations or sister chromatid exchanges. Collectively, our results do not support a role for FancG during DNA replication that deals specifically with processing DNA crosslinks. Nor do they suggest that the main function of the FA protein "pathway" is to promote efficient homologous recombination. We propose that the primary function of FA proteins is to maintain chromosomal continuity by stabilizing replication forks that encounter nicks, gaps, or replication-blocking lesions. (C) 2004 Elsevier B.V. All rights reserved. C1 Lawrence Livermore Natl Lab, Biol & Biotechnol Res Program, Livermore, CA 94551 USA. Univ Liverpool, Sch Biol Sci, Liverpool L69 7ZB, Merseyside, England. RP Thompson, LH (reprint author), Lawrence Livermore Natl Lab, Biol & Biotechnol Res Program, POB 808, Livermore, CA 94551 USA. EM thompson14@llnl.gov RI Jones, Nigel/D-1997-2010 FU NCI NIH HHS [CA89405] NR 77 TC 48 Z9 48 U1 1 U2 6 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 1568-7864 J9 DNA REPAIR JI DNA Repair PD JAN 2 PY 2005 VL 4 IS 1 BP 11 EP 22 DI 10.1016/j.dnarep.2004.06.013 PG 12 WC Genetics & Heredity; Toxicology SC Genetics & Heredity; Toxicology GA 874DR UT WOS:000225331600002 PM 15533833 ER PT B AU Smith, JA Silvestri, NM Oswalt, TD Harris, HC Kleinman, SJ Munn, JA Nitta, A Rudkin, MA AF Smith, JA Silvestri, NM Oswalt, TD Harris, HC Kleinman, SJ Munn, JA Nitta, A Rudkin, MA BE Koester, D Moehler, S TI Sloan Digital Sky Survey: Proper motion systems containing white dwarfs SO 14TH EUROPEAN WORKSHOP ON WHITE DWARFS, PROCEEDINGS SE Astronomical Society of the Pacific Conference Series LA English DT Proceedings Paper CT 14th European Workshop on White Dwarfs CY JUN 19-JUL 23, 2004 CL Kiel, GERMANY ID 1ST DATA RELEASE; CATALOG; STARS AB We present plans to develop a catalog of common proper motion binaries containing at least one white dwarf component from the Sloan Digital Sky Survey. We base the search on the public Sloan Digital Sky Survey data releases to date (DR-1; DR-2, and DR-3) and the subsequent white dwarf catalogs drawn from these data. The listings will include the spectroscopically identified white dwarfs (generally hot) and the proper motion identified white dwarfs (generally cooler). C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Smith, JA (reprint author), Los Alamos Natl Lab, D448, Los Alamos, NM 87545 USA. EM toswalt@fit.edu; sjnk@apo.nmsu.edu; ank@apo.nmsu.edu NR 14 TC 0 Z9 0 U1 0 U2 0 PU ASTRONOMICAL SOC PACIFIC PI SAN FRANCISCO PA 390 ASHTON AVE, SAN FRANCISCO, CA 94112 USA BN 1-58381-197-4 J9 ASTR SOC P PY 2005 VL 334 BP 127 EP 130 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BDY48 UT WOS:000236131800027 ER PT B AU Tierney, BL Gunter, DK AF Tierney, BL Gunter, DK GP IEEE TI Techniques for tuning workflows in cluster environments SO 14TH IEEE INTERNATIONAL SYMPOSIUM ON HIGH PERFORMANCE DISTRIBUTED COMPUTING, PROCEEDINGS LA English DT Proceedings Paper CT 14th IEEE International Symposium on High Performance Distributed Computing CY JUL 24-27, 2005 CL Res Triangle Pk, NC SP IEEE, IEEE Comp Soc AB An important class of parallel processing jobs on clusters today are workflow-based applications that process large amounts of data in parallel. Traditional cluster performance tools are designed for tightly coupled parallel jobs, and not as effective for this type of application. We describe how the NetLogger Toolkit methodology is more appropriate for this class of cluster computing, and describe our new automatic workflow anomaly detection component. We also describe how this methodology is being used by the Nearby Supernova Factory (SNfactory) project at Lawrence Berkeley National Laboratory. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Distributed Syst Dept, Berkeley, CA 94720 USA. RP Tierney, BL (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Distributed Syst Dept, Berkeley, CA 94720 USA. NR 2 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-9037-7 PY 2005 BP 303 EP 305 PG 3 WC Computer Science, Theory & Methods SC Computer Science GA BCX63 UT WOS:000231776400038 ER PT B AU Mezzacappa, A AF Mezzacappa, A BE Turatto, M Benetti, S Zampieri, L Shea, W TI The core collapse supernova mechanism: Current models, gaps, and the road ahead SO 1604-2004: Supernovae as Cosmological Lighthouses SE ASTRONOMICAL SOCIETY OF THE PACIFIC CONFERENCE SERIES LA English DT Proceedings Paper CT Conference on 1604-2004 - Supernovae as Cosmological Lighthouses CY JUN 15-19, 2004 CL Univ Degli Studi Padova, Padua, ITALY HO Univ Degli Studi Padova ID RADIATION HYDRODYNAMICS; NEUTRINO TRANSPORT; EXPLOSIONS; EQUATION; MATTER; STATE; INSTABILITIES; MULTIGROUP; SIMULATION; CONVECTION AB The pursuit of the core collapse supernova explosion mechanism continues. While such efforts have been undertaken over the last four decades, it is only in the last decade that multidimensional models have been developed, and only in the last few years that significant components of supernova, models, such as the neutrino transport, have been modeled with sufficient realism, We can now identify what are arguably the important components that must be included in any realistic three-dimensional supernova model. The challenge we now face is to include all of these in the models. C1 Oak Ridge Natl Lab, Div Phys, Oak Ridge, TN 37831 USA. RP Mezzacappa, A (reprint author), Oak Ridge Natl Lab, Div Phys, Oak Ridge, TN 37831 USA. RI Mezzacappa, Anthony/B-3163-2017 OI Mezzacappa, Anthony/0000-0001-9816-9741 NR 38 TC 10 Z9 10 U1 0 U2 0 PU ASTRONOMICAL SOC PACIFIC PI SAN FRANCISCO PA 390 ASHTON AVE, SAN FRANCISCO, CA 94112 USA BN 1-58381-209-1 J9 ASTR SOC P PY 2005 VL 342 BP 175 EP 183 PG 9 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BDX50 UT WOS:000235953000028 ER PT B AU Nugent, P AF Nugent, P BE Turatto, M Benetti, S Zampieri, L Shea, W TI Ultraviolet Spectroscopy of type Ia supernovae at low and high-redshift SO 1604-2004: Supernovae as Cosmological Lighthouses SE ASTRONOMICAL SOCIETY OF THE PACIFIC CONFERENCE SERIES LA English DT Proceedings Paper CT Conference on 1604-2004 - Supernovae as Cosmological Lighthouses CY JUN 15-19, 2004 CL Univ Degli Studi Padova, Padua, ITALY HO Univ Degli Studi Padova ID ACCELERATING UNIVERSE; DECELERATION AB In the past three years two separate programs were initiated to study the rest-frame UV properties of Type Ia Supernovae (SNe). The low-redshift study was carried out using several ground-based facilities coupled with HST/STIS observations. The high-redshift program is an offshoot of the CFHT Legacy Survey and uses Keck/LRIS to obtain spectra. Here we present the preliminary results from each program and their implications for current cosmology measurements. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Nugent, P (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, MS 50F-1650,1 Cyclotron Rd, Berkeley, CA 94720 USA. NR 10 TC 0 Z9 0 U1 0 U2 0 PU ASTRONOMICAL SOC PACIFIC PI SAN FRANCISCO PA 390 ASHTON AVE, SAN FRANCISCO, CA 94112 USA BN 1-58381-209-1 J9 ASTR SOC P PY 2005 VL 342 BP 224 EP 228 PG 5 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BDX50 UT WOS:000235953000038 ER PT B AU O'Keefe, M Walkowicz, K Hendricks, T AF O'Keefe, M Walkowicz, K Hendricks, T BE Selvaraj, H Muthukumar, V TI A technology optimization process for heavy hybrid electric vehicle systems using computational models SO 18th International Conference on Systems Engineering, Proceedings LA English DT Proceedings Paper CT 18th International Conference on Systems Engineering (ICSEng 2005) CY AUG 16-18, 2005 CL Univ Nevada Las Vegas, Las Vegas, NV SP ALDEC, Project Performance Int HO Univ Nevada Las Vegas AB We have developed a computer-based technology optimization process to define vehicle systems that meet specified goals and constraints using a minimum amount of resources. The process is built around answering three questions: Where are we now? Where do we want to go? And what is the best way to get there? A technical target selling algorithm helps answer the last question. The target setting algorithm uses computational models that predict system responses for various combinations of technology attributes, quantitatively defined requirements and goals, and relationships between improvements in technology attributes and resource requirements. The algorithm yields the mix of technologies that achieve overall program and vehicle goals using a minimum amount of resources. This process was developed for and applied to the U.S. Department of Energy's Advanced Heavy Hybrid Propulsion Systems activity. In this paper, we describe the technology optimization process, with a focus on technical target setting, and illustrate its use with a simple example. C1 Natl Renewable Energy Lab, Golden, CO 80401 USA. RP O'Keefe, M (reprint author), Natl Renewable Energy Lab, Golden, CO 80401 USA. NR 2 TC 3 Z9 3 U1 0 U2 0 PU IEEE COMPUTER SOC PI LOS ALAMITOS PA 10662 LOS VAQUEROS CIRCLE, PO BOX 3014, LOS ALAMITOS, CA 90720-1264 USA BN 0-7695-2359-5 PY 2005 BP 475 EP 480 DI 10.1109/ICSENG.2005.13 PG 6 WC Automation & Control Systems; Computer Science, Artificial Intelligence; Computer Science, Hardware & Architecture; Computer Science, Theory & Methods; Engineering, Industrial SC Automation & Control Systems; Computer Science; Engineering GA BEA45 UT WOS:000236450300076 ER PT S AU Chandonia, JM Brenner, SE AF Chandonia, J. -M. Brenner, S. E. GP IEEE TI Update on the Pfam5000 strategy for selection of structural genomics targets SO 2005 27th Annual International Conference of the IEEE Engineering in Medicine and Biology Society, Vols 1-7 SE PROCEEDINGS OF ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY LA English DT Proceedings Paper CT 27th Annual International Conference of the IEEE-Engineering-in-Medicine-and-Biology-Society CY AUG 31-SEP 03, 2005 CL Shanghai, PEOPLES R CHINA SP IEEE Engn Med & Biol Soc, Chinese Acad Engn Sci ID HIDDEN MARKOV-MODELS; DATABASE; BIOLOGY; PREDICTION AB Structural Genomics is an international effort to determine the three-dimensional shapes of all important biological macromolecules, with a primary focus on proteins. Target proteins should be selected according to a strategy that is medically and biologically relevant, of good financial value, and tractable. In 2003, we presented the "Pfam5000" strategy, which involves selecting the 5,000 most important famines from the Pfam database as sources for targets. In this update, we show that although both the Pfam database and the number of sequenced genomes have increased in size, the expected benefits of the Pfam5000 strategy have not changed substantially. Solving the structures of proteins from the 5,000 largest Pfam families would allow accurate fold assignment for approximately 65% of all prokaryotic proteins (covering 54% of residues) and 63% of eukaryotic proteins (42% of residues). Fewer than 2,300 of the largest families on this list remain to be solved, making the project feasible in the next five years given the expected throughput to be achieved in the production phase of the Protein Structure Initiative. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Phys Biosci Div, Berkeley Struct Genom Ctr, Berkeley, CA 94720 USA. RP Chandonia, JM (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Phys Biosci Div, Berkeley Struct Genom Ctr, Berkeley, CA 94720 USA. RI Brenner, Steven/A-8729-2008 OI Brenner, Steven/0000-0001-7559-6185 NR 23 TC 1 Z9 2 U1 0 U2 3 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1094-687X BN 0-7803-8740-6 J9 P ANN INT IEEE EMBS PY 2005 BP 751 EP 755 DI 10.1109/IEMBS.2005.1616523 PG 5 WC Engineering, Biomedical SC Engineering GA BER00 UT WOS:000238998400197 ER PT S AU Maltz, JS Ng, TSC Li, DJ Wang, J Wang, K Bergeron, W Martin, R Budinger, TF AF Maltz, Jonathan S. Ng, Thomas S. C. Li, Dustin J. Wang, Jian Wang, Kang Bergeron, William Martin, Ron Budinger, Thomas F. GP IEEE TI The Trauma Patient Tracking System: implementing a wireless monitoring infrastructure for emergency response SO 2005 27th Annual International Conference of the IEEE Engineering in Medicine and Biology Society, Vols 1-7 SE PROCEEDINGS OF ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY LA English DT Proceedings Paper CT 27th Annual International Conference of the IEEE-Engineering-in-Medicine-and-Biology-Society CY AUG 31-SEP 03, 2005 CL Shanghai, PEOPLES R CHINA SP IEEE Engn Med & Biol Soc, Chinese Acad Engn Sci DE biomonitoring; trauma; emergency; wireless monitoring AB In mass trauma situations, emergency personnel are challenged with the task of prioritizing the care of many injured victims. We propose a trauma patient tracking system (TPTS) where first-responders tag all patients with a wireless monitoring device that continuously reports the location of each patient. The system can be used not only to prioritize patient care, but also to determine the time taken for each patient to receive treatment. This is important in training emergency personnel and in identifying bottlenecks in the disaster response process. In situations where biochemical agents are involved, a TPTS may be employed to determine sites of cross-contamination. In order to track patient location in both outdoor and indoor environments, we employ both Global Positioning System (GPS) and Television/Radio Frequency (TVRF) technologies. Each patient tag employs IEEE 802.11 (Wi-Fi)/TCP/IP networking to communicate with a central server via any available Wi-Fi basestation. A key component to increase TPTS fault-tolerance is a mobile Wi-Fi basestation that employs redundant Internet connectivity to ensure that tags at the disaster scene can send information to the central server even when local infrastructure is unavailable for use. We demonstrate the robustness of the system in tracking multiple patients in a simulated trauma situation in an urban environment. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Dept Funct Imaging, Berkeley, CA 94720 USA. RP Maltz, JS (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Dept Funct Imaging, Berkeley, CA 94720 USA. NR 4 TC 2 Z9 2 U1 0 U2 4 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1094-687X BN 0-7803-8740-6 J9 P ANN INT IEEE EMBS PY 2005 BP 2441 EP 2446 DI 10.1109/IEMBS.2005.1616962 PG 6 WC Engineering, Biomedical SC Engineering GA BER00 UT WOS:000238998402064 ER PT S AU Luo, ZC Benveniste, H Yu, M Du, CW AF Luo, ZC Benveniste, H Yu, M Du, CW GP IEEE TI Activation-blood flow coupling during direct somatosensory cortical stimulation in living rat brain SO 2005 2ND INTERNATINOAL IEEE/EMBS CONFERENCE ON NEURAL ENGINEERING SE International IEEE EMBS Conference on Neural Engineering LA English DT Proceedings Paper CT 2nd International IEEE/EMBS Conference on Neural Engineering CY MAR 16-20, 2005 CL Arlington, VA SP IEEE, EMBS, Natl Sci Fdn, Inst Phys, Off Naval Res Global ID LASER-DOPPLER FLOWMETRY; CORTEX; OXYGENATION; VOLUME AB Laser Doppler flowmetry was used to characterize the cortical activation-blood flow coupling due to direct stimulation in somatosensory cortex of rat brain in vivo. Both amplitude and duration of the flow response increased along with the increases in stimulation current. Flow response became to saturate in a high-grade stimulation with the current above 0.3 mA. The flow response also featured a fast activation due to the stimulus and a slow recovery, which may imply an indirect coupling between neural activity and recruitment of local blood delivery. C1 Brookhaven Natl Lab, Dept Med, Upton, NY 11973 USA. RP Luo, ZC (reprint author), Brookhaven Natl Lab, Dept Med, Upton, NY 11973 USA. NR 15 TC 5 Z9 5 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1948-3546 BN 0-7803-8709-0 J9 I IEEE EMBS C NEUR E PY 2005 BP 664 EP 666 PG 3 WC Computer Science, Artificial Intelligence; Computer Science, Interdisciplinary Applications; Engineering, Biomedical SC Computer Science; Engineering GA BCI92 UT WOS:000229610400177 ER PT B AU Barrett, LM Skulan, AJ Singh, AK Cummings, EB Fiechtner, GJ AF Barrett, LM Skulan, AJ Singh, AK Cummings, EB Fiechtner, GJ GP IEEE TI Insulating dielectrophoresis for the continuous separation and concentration of Bacillus subtilis. SO 2005 3rd IEEE/EMBS Special Topic Conference on Microtechnology in Medicine and Biology SE IEEE Engineering in Medicine and Biology Society Annual Conference (EMBS) LA English DT Proceedings Paper CT 3rd IEEE/EMBS Special Topic Conference on Microtechnology in Medicine and Biology CY MAY 12-15, 2005 CL Oahu, HI SP IEEE, EMBS DE dielectrophoresis; separation; cells; particles; Bacillus subtilis ID BACTERIA; LIVE AB This paper presents a novel microdevice for the dielectrophoretic manipulation of particles and cells for sample preparation and analysis. A two level isotropic etch of a glass substrate was used to create insulating ridges in micron sized channels. These ridges created a non-uniform field when a direct current field was applied across the channel and the dielectrophoretic force that resulted from the ridge was used to manipulate particles. We show the continuous concentration and separation of Bacillus subtilis from a two component sample mixture. When the applied voltage is at or above 30V/mm the flow of Bacillus subtilis was restricted to the central channel as a result of negative DEP away from the field concentration produced by the insulating ridges. Under the same applied electric fields the 200-nm polystyrene particles DEP away from the insulating ridges was negligible for the 200-nm particles, which flowed uninhibited down the three exit channels. C1 Sandia Natl Labs, Livermore, CA 94550 USA. RP Barrett, LM (reprint author), Sandia Natl Labs, Livermore, CA 94550 USA. NR 6 TC 0 Z9 0 U1 2 U2 2 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-8711-2 J9 ENG MED BIOL SOC ANN PY 2005 BP 3 EP 4 DI 10.1109/MMB.2005.1548366 PG 2 WC Engineering, Biomedical SC Engineering GA BDL92 UT WOS:000234204800003 ER PT B AU Herr, AE Throckmorton, DJ Singh, AK AF Herr, AE Throckmorton, DJ Singh, AK GP IEEE TI Electrophoretic immunoassays for oral diagnostics SO 2005 3rd IEEE/EMBS Special Topic Conference on Microtechnology in Medicine and Biology SE IEEE Engineering in Medicine and Biology Society Annual Conference (EMBS) LA English DT Proceedings Paper CT 3rd IEEE/EMBS Special Topic Conference on Microtechnology in Medicine and Biology CY MAY 12-15, 2005 CL Oahu, HI SP IEEE, EMBS DE electrophoresis; immunoassay; medical diagnostic; microfluidic; saliva ID CHIP; DISEASE AB Analysis of oral fluid (e.g., saliva) has the potential to aid diagnosis of both oral and systemic diseases. Oral fluids offer advantages over other bodily fluids, including quick, non-invasive, and inexpensive collection in both clinical and non-clinical settings. Nevertheless, current assay techniques using saliva are time-consuming, require large sample volumes, and are not amenable to automation or portability. We report on a robust microfluidic platform that performs rapid immunoassay-based analysis (< 3 minutes) of saliva with low sample volume requirements (10 mu L) and appreciable sensitivity (10(-12) M) with a high-degree of autonomy. Immunoassays for the detection of the systemic disease biomarker, C-reactive protein, and the cytokines interleukin-6 and tumor necrosis factor-alpha were conducted in spiked human saliva using a microfluidic chip. The immunoassay developed is based on binding of fluorescently-labeled reporter antibodies to analytes followed by electrophoretic separation and quantitation of bound and unbound reporter. The separation selectivity was achieved using native polyacrylamide gel electrophoresis in microchip containing in situ photolithographically patterned cross-linked polyacrylamide. Native electrophoresis conditions maintained the integrity of fragile immune complexes and provided rapid separations of complex samples. On-going work focuses on integration of the on-chip immunoassay with miniaturized hardware towards developing a portable prototype. C1 Sandia Natl Labs, Biosyst Res Dept, Livermore, CA 94550 USA. RP Herr, AE (reprint author), Sandia Natl Labs, Biosyst Res Dept, Livermore, CA 94550 USA. NR 5 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-8711-2 J9 ENG MED BIOL SOC ANN PY 2005 BP 53 EP 55 DI 10.1109/MMB.2005.1548382 PG 3 WC Engineering, Biomedical SC Engineering GA BDL92 UT WOS:000234204800019 ER PT B AU Skulan, AJ Barrett, LM Fiechtner, GJ Singh, AK Cummings, EB Simmons, BA AF Skulan, AJ Barrett, LM Fiechtner, GJ Singh, AK Cummings, EB Simmons, BA GP IEEE TI Particle mixing and concentration through competing electrokinetic and hydrodynamic flows SO 2005 3rd IEEE/EMBS Special Topic Conference on Microtechnology in Medicine and Biology SE IEEE Engineering in Medicine and Biology Society Annual Conference (EMBS) LA English DT Proceedings Paper CT 3rd IEEE/EMBS Special Topic Conference on Microtechnology in Medicine and Biology CY MAY 12-15, 2005 CL Oahu, HI SP IEEE, EMBS ID MICROFLUIDIC SYSTEMS; CHANNELS C1 Sandia Natl Labs, Livermore, CA 94550 USA. RP Skulan, AJ (reprint author), Sandia Natl Labs, 7011 E Ave,MS 9951, Livermore, CA 94550 USA. NR 5 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-8711-2 J9 ENG MED BIOL SOC ANN PY 2005 BP 280 EP 281 DI 10.1109/MMB.2005.1548448 PG 2 WC Engineering, Biomedical SC Engineering GA BDL92 UT WOS:000234204800085 ER PT B AU Trebotich, D Miller, GH AF Trebotich, D Miller, GH GP IEEE TI Modeling and simulation of DNA flow in a microfluidic-based pathogen detection system SO 2005 3rd IEEE/EMBS Special Topic Conference on Microtechnology in Medicine and Biology SE IEEE Engineering in Medicine and Biology Society Annual Conference (EMBS) LA English DT Proceedings Paper CT 3rd IEEE/EMBS Special Topic Conference on Microtechnology in Medicine and Biology CY MAY 12-15, 2005 CL Oahu, HI SP IEEE, EMBS DE DNA; polymer flow; pathogen detection; bioMEMS; PCR; microfluidics; modeling ID ADAPTIVE MESH REFINEMENT; EMBEDDED BOUNDARY METHOD; NAVIER-STOKES EQUATIONS; PROJECTION METHOD AB We present simulation results from a new computational model of DNA flow in microfluidic devices. This work is important because computational models are needed to design miniaturized biomedical devices that are becoming the state-of-the-art in many significant applications including pathogen detection as well as continuous monitoring and drug delivery. Currently advanced algorithms in design tools are non-existent but necessary to understand the complex fluid and polymer dynamics involved in biological flow at small scales. Our model is based on a fully coupled fluid-particle numerical algorithm with both stochastic and deterministic components in a bead-rod polymer representation. We have applied this work to DNA extraction configurations in a microfluidic PCR chamber used in a pathogen detection system. We demonstrate our method on the test problem of flow of a single DNA molecule in a 2D packed array microchannel. We are also investigating mechanisms for molecular "sticking" using short range forces. C1 Lawrence Livermore Natl Lab, Ctr Appl Sci Comp, Livermore, CA 94551 USA. RP Trebotich, D (reprint author), Lawrence Livermore Natl Lab, Ctr Appl Sci Comp, POB 808,L-560, Livermore, CA 94551 USA. NR 9 TC 0 Z9 0 U1 0 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-8711-2 J9 ENG MED BIOL SOC ANN PY 2005 BP 353 EP 355 DI 10.1109/MMB.2005.1548471 PG 3 WC Engineering, Biomedical SC Engineering GA BDL92 UT WOS:000234204800108 ER PT S AU Gurvits, L Samorodnitsky, A AF Gurvits, Leonid Samorodnitsky, Alex GP IEEE TI A note on common quadratic Lyapunov functions for linear inclusions : Exact results and Open Problems SO 2005 44TH IEEE CONFERENCE ON DECISION AND CONTROL & EUROPEAN CONTROL CONFERENCE, VOLS 1-8 SE IEEE Conference on Decision and Control LA English DT Proceedings Paper CT 44th IEEE Conference on Decision Control/European Control Conference (CCD-ECC) CY DEC 12-15, 2005 CL Seville, SPAIN SP IEEE Control Syst Soc, European Union Control Assoc, IFAC, INFORMS, SIAM, SICE, Honeywell, MathWorks AB We prove several exact results on approximability of joint spectral radius by matrix norms induced by Euclidean norms. We point out, perhaps for the first time in this context, a difference between complex and real cases. New connections of joint spectral radius to convex geometry and combinatorics are established. Several open problems are posed. C1 Los Alamos Natl Lab, Los Alamos, NM USA. RP Gurvits, L (reprint author), Los Alamos Natl Lab, POB 1663, Los Alamos, NM USA. EM gurvits@lanl.gov; salex@cs.huji.ac.il NR 4 TC 2 Z9 2 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 0191-2216 BN 0-7803-9567-0 J9 IEEE DECIS CONTR P PY 2005 BP 2350 EP 2355 PG 6 WC Automation & Control Systems SC Automation & Control Systems GA BFB21 UT WOS:000240653702051 ER PT B AU Amin, K von Laszewski, G Sosonkin, M Mikler, AR Hategan, M AF Amin, K von Laszewski, G Sosonkin, M Mikler, AR Hategan, M GP IEEE TI Ad hoc Grid security infrastructure SO 2005 6TH INTERNATIONAL WORKSHOP ON GRID COMPUTING (GRID) LA English DT Proceedings Paper CT 6th International Workshop on Grid Computing CY NOV 13-14, 2005 CL Seattle, WA SP IEEE Comp Soc, TCSC, ACM AB This paper describes an ad hoc Grid security infrastructure developed as a part of the Java CoG Kit project. It supports several requirements specific to the sporadic nature of ad hoc Grids. It focuses on identity management, identity verification, and authorization control in spontaneous Grid collaborations without pre-established policies or environments. It adopts established community standards, with modifications where needed. This paper also discusses the integration of the ad hoc Grid security infrastructure in an ad hoc Grid implementation. The implementation supports secure collaboration in ad hoc Grids using commodity technologies such as the Java CoG Kit, JXTA, GSI, and XACML. C1 Argonne Natl Lab, Div Math & Comp Sci, Argonne, IL 60439 USA. RP Argonne Natl Lab, Div Math & Comp Sci, Argonne, IL 60439 USA. EM gregor@mcs.anl.gov RI von Laszewski, Gregor/C-2808-2012 OI von Laszewski, Gregor/0000-0001-9558-179X NR 17 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-9492-5 PY 2005 BP 69 EP 76 PG 8 WC Computer Science, Theory & Methods SC Computer Science GA BDZ76 UT WOS:000236352900010 ER PT B AU Sonnek, JD Weissman, JB AF Sonnek, JD Weissman, JB GP IEEE TI A quantitative comparison of reputation systems in the grid SO 2005 6TH INTERNATIONAL WORKSHOP ON GRID COMPUTING (GRID) LA English DT Proceedings Paper CT 6th International Workshop on Grid Computing CY NOV 13-14, 2005 CL Seattle, WA SP IEEE Comp Soc, TCSC, ACM DE grid computing; reputation systems; trust models; resource scheduling AB Reputation systems have been a hot topic in the peer-to-peer community for several years. In a services-oriented distributed computing environment like the Grid, reputation systems can be utilized by clients to select between competing service providers. In this paper, we selected several existing reputation algorithms and adapted them to the problem of service selection in a Grid-like environment. We performed a quantitative comparison of both the accuracy and overhead associated with these techniques under common scenarios. The results indicate that using a reputation system to guide service selection can significantly improve client satisfaction with minimal overhead. In addition, we show that the most appropriate algorithm depends on the kinds of anticipated attacks. A new algorithm we've proposed appears to be the approach of choice if clients can misreport service ratings. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. EM jsonnek@gmail.com; jon@cs.umn.edu NR 13 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-9492-5 PY 2005 BP 242 EP 249 PG 8 WC Computer Science, Theory & Methods SC Computer Science GA BDZ76 UT WOS:000236352900032 ER PT B AU Tuncer, E Bowler, N AF Tuncer, E Bowler, N TI An empirical dielectric mixture expression and its application to composites SO 2005 Annual Report Conference on Electrical Insulation and Dielectric Phenomena LA English DT Proceedings Paper CT Annual Conference on Electrical Insulation and Dielectric Phenomena (CEIDP) CY OCT 16-19, 2005 CL Nashville, TN SP IEEE, Dielectr & Elect Insulat Soc ID BOUNDS; RELAXATION; CONSTANT AB In this contribution, we focus not only on predicting the dielectric properties of heterogeneous media but also on extracting the topological description of such materials. We propose a novel empirical expression for binary dielectric mixtures with phase permittivities epsilon(1) and epsilon(2). The expression is derived for a scaled permittivity level, denoted with xi[= (epsilon(e) - epsilon(l))(epsilon(2) - epsilon(1))(-1)], here subscript W represents the permittivity of the effective medium. The proposed expression yields the volume fraction of constituents and topological information when the permittivities of the constituents are known in advance. We apply the expression to various selected composites to acquire the structure-property relationship in these materials. C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Tuncer, E (reprint author), Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. OI Tuncer, Enis/0000-0002-9324-4324 NR 17 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-9257-4 PY 2005 BP 152 EP 154 PG 3 WC Engineering, Electrical & Electronic; Physics, Condensed Matter SC Engineering; Physics GA BDX16 UT WOS:000235927000037 ER PT B AU Tuncer, E AF Tuncer, E TI Dielectric relaxation and dielectric mixtures: Similarities SO 2005 Annual Report Conference on Electrical Insulation and Dielectric Phenomena LA English DT Proceedings Paper CT Annual Conference on Electrical Insulation and Dielectric Phenomena (CEIDP) CY OCT 16-19, 2005 CL Nashville, TN SP IEEE, Dielectr & Elect Insulat Soc ID 2-COMPONENT COMPOSITE-MATERIAL; ANALYTIC CONTINUATION; EFFECTIVE PARAMETERS; RIGOROUS BOUNDS; CONSTANT; MEDIA AB Spectral density representation is a tool to analyze electrical properties of material mixtures and the geometrical description of the system. The aim of this paper is to derive an expression for the spectral density representation, which favors dielectric relaxation phenomenon. This unfamiliar form is distinct in a way that the excisting dielectric relaxation models and data analysis tools can be employed for extracting the spectral density function of a given system. C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Tuncer, E (reprint author), Oak Ridge Natl Lab, POB 2008, Oak Ridge, TN 37831 USA. OI Tuncer, Enis/0000-0002-9324-4324 NR 24 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-9257-4 PY 2005 BP 725 EP 726 PG 2 WC Engineering, Electrical & Electronic; Physics, Condensed Matter SC Engineering; Physics GA BDX16 UT WOS:000235927000179 ER PT B AU Rudd, JV Law, RJ Atherton, BW Luk, TS Cameron, SM AF Rudd, JV Law, RJ Atherton, BW Luk, TS Cameron, SM GP IEEE TI High-power optical parametric chirped-pulse amplifier system with 1.6-mu m signal and 1.064-mu m pump SO 2005 Conference on Lasers & Electro-Optics (CLEO), Vols 1-3 LA English DT Proceedings Paper CT Conference on Lasers and Electro-Optics (CLEO) CY MAY 22-27, 2005 CL Baltimore, MD AB Optical parametric chirped-pulse amplifiers utilizing a 300-ps Nd:YAG pump system, a tunable 1.6-mu m fiber signal, and KNbO3, KTA, RTP, or BBO nonlinear crystals were designed and built. Gain > 10(9), and peak powers > 30GW were obtained. (c) 2005 Optical Society of America. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Rudd, JV (reprint author), Sandia Natl Labs, POB 5800,MS1153, Albuquerque, NM 87185 USA. NR 2 TC 0 Z9 0 U1 0 U2 0 PU OPTICAL SOC AMERICA PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA BN 1-55752-795-4 PY 2005 BP 22 EP 24 PG 3 WC Optics SC Optics GA BDP70 UT WOS:000234819900008 ER PT B AU Tsao, JY AF Tsao, JY GP IEEE TI Solid-state lighting: Lamps, chips and materials for tomorrow SO 2005 Conference on Lasers & Electro-Optics (CLEO), Vols 1-3 LA English DT Proceedings Paper CT Conference on Lasers and Electro-Optics (CLEO) CY MAY 22-27, 2005 CL Baltimore, MD AB In this talk, we give an overview of some of the key challenges that solid-state lighting technology faces if it is to achieve its potential for general white lighting. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Tsao, JY (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU OPTICAL SOC AMERICA PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA BN 1-55752-795-4 PY 2005 BP 143 EP 143 PG 1 WC Optics SC Optics GA BDP70 UT WOS:000234819900049 ER PT B AU Negres, RA DeMange, P Radousky, HB Demos, SG AF Negres, RA DeMange, P Radousky, HB Demos, SG GP IEEE TI Investigation of laser-induced damage in KDP crystals under simultaneous exposure to laser harmonics SO 2005 Conference on Lasers & Electro-Optics (CLEO), Vols 1-3 LA English DT Proceedings Paper CT Conference on Lasers and Electro-Optics (CLEO) CY MAY 22-27, 2005 CL Baltimore, MD ID KH2PO4 AB We investigate the laser-induced damage behavior of KDP and DKDP crystals under simultaneous multi - wavelength irradiation as a function of laser fluences to approximate conditions during frequency conversion. Our results reveal fundamental behaviors of damage initiation. C1 Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. RP Negres, RA (reprint author), Lawrence Livermore Natl Lab, POB 808,7000 E Ave, Livermore, CA 94551 USA. NR 6 TC 0 Z9 0 U1 1 U2 1 PU OPTICAL SOC AMERICA PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA BN 1-55752-795-4 PY 2005 BP 241 EP 243 PG 3 WC Optics SC Optics GA BDP70 UT WOS:000234819900084 ER PT B AU Page, RH Beach, RJ Kanz, VK Krupke, WF AF Page, RH Beach, RJ Kanz, VK Krupke, WF GP IEEE TI First demonstration of a diode-pumped gas (alkali vapor) laser SO 2005 Conference on Lasers & Electro-Optics (CLEO), Vols 1-3 LA English DT Proceedings Paper CT Conference on Lasers and Electro-Optics (CLEO) CY MAY 22-27, 2005 CL Baltimore, MD AB We report the first diode-pumped gas laser-rubidium vapor. A short cell charged with a Rb/ethane/He mixture pumped at 780 nm produced several mW in a near-confocal cavity. Issues involved in power-scaling will be discussed. (c) 2005 Optical Society of America. C1 Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. RP Page, RH (reprint author), Lawrence Livermore Natl Lab, 7000 East Ave, Livermore, CA 94551 USA. NR 7 TC 0 Z9 0 U1 1 U2 2 PU OPTICAL SOC AMERICA PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA BN 1-55752-795-4 PY 2005 BP 467 EP 469 PG 3 WC Optics SC Optics GA BDP70 UT WOS:000234819900160 ER PT B AU Rademaker, K Krupke, WF Payne, SA Heumann, E Huber, G Kueck, S Isaenko, LI Burger, A AF Rademaker, K Krupke, WF Payne, SA Heumann, E Huber, G Kueck, S Isaenko, LI Burger, A GP IEEE TI Laser activity at 1.18, 1.07, and 0.97 mu m and depopulation mechanisms of the lower laser levels in Nd3+ doped KPb2Br5 and RbPb2Br5 SO 2005 Conference on Lasers & Electro-Optics (CLEO), Vols 1-3 LA English DT Proceedings Paper CT Conference on Lasers and Electro-Optics (CLEO) CY MAY 22-27, 2005 CL Baltimore, MD ID CRYSTALS AB Laser activity has been achieved in low-phonon energy, moisture-resistant neodymium-doped bromide host crystals, also resulting from the F-4(5/2)+2H(9/2) level for the first time in any solid-state material. Pump-probe spectra reveal mechanisms feasible for more efficient laser operation. (c) 2005 Optical Society of America. C1 Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Rademaker, K (reprint author), Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RI Isaenko, Ludmila/H-7620-2013; Isaenko, Ludmila/A-5272-2014 NR 7 TC 0 Z9 0 U1 0 U2 1 PU OPTICAL SOC AMERICA PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA BN 1-55752-795-4 PY 2005 BP 927 EP 929 PG 3 WC Optics SC Optics GA BDP70 UT WOS:000234819901053 ER PT B AU Efimov, A Taylor, AJ Omenetto, FC AF Efimov, A Taylor, AJ Omenetto, FC GP IEEE TI Analysis of supercontinuum generation in soft glass photonic crystal fibers with cross-correlation frequency-resolved optical gating SO 2005 Conference on Lasers & Electro-Optics (CLEO), Vols 1-3 LA English DT Proceedings Paper CT Conference on Lasers and Electro-Optics (CLEO) CY MAY 22-27, 2005 CL Baltimore, MD ID ULTRASHORT PULSES; PHASE AB Initial stages of supercontinuum generation in SF6 extruded photonic crystal fiber are experimentally studied with X-FROG and spectral measurements. Self-steepening is clearly observed and its role in generation of anti-Stokcs blueshifted spectral components is highlighted. (c) 2005 Optical Society of America. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Efimov, A (reprint author), Los Alamos Natl Lab, MST-10,MSK764, Los Alamos, NM 87545 USA. NR 7 TC 0 Z9 0 U1 1 U2 1 PU OPTICAL SOC AMERICA PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA BN 1-55752-795-4 PY 2005 BP 1223 EP 1225 PG 3 WC Optics SC Optics GA BDP70 UT WOS:000234819901154 ER PT B AU Fortier, TM Bartels, A Diddams, SA AF Fortier, TM Bartels, A Diddams, SA GP IEEE TI A 600 MHz octave-spanning femtosecond laser for optical frequency measurements and comparisons SO 2005 CONFERENCE ON LASERS & ELECTRO-OPTICS (CLEO), VOLS 1-3 LA English DT Proceedings Paper CT Conference on Lasers and Electro-Optics (CLEO) CY MAY 22-27, 2005 CL Baltimore, MD AB We demonstrate a self-referenced 600 MHz, octave-spanning laser capable of measuring beat signals against atomic standards over an optical bandwidth from (532 nm - 1200 nm) without additional broadening in optical fiber. C1 Los Alamos Natl Lab, Div Phys, Los Alamos, NM 87545 USA. RP Los Alamos Natl Lab, Div Phys, P-23,Mail Stop H803, Los Alamos, NM 87545 USA. EM fortier@boulder.nist.gov RI Diddams, Scott/L-2819-2013 NR 7 TC 0 Z9 0 U1 0 U2 0 PU OPTICAL SOC AMERICA PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA BN 1-55752-795-4 PY 2005 BP 1632 EP 1634 PG 3 WC Optics SC Optics GA BDP70 UT WOS:000234819902027 ER PT B AU Rudd, JV Zutavern, FJ Collins, RT McPherson, LA Nelson, TR Luk, TS Cameron, SM AF Rudd, JV Zutavern, FJ Collins, RT McPherson, LA Nelson, TR Luk, TS Cameron, SM GP IEEE TI Plasma sources & sensors of near terahertz radiation SO 2005 Conference on Lasers & Electro-Optics (CLEO), Vols 1-3 LA English DT Proceedings Paper CT Conference on Lasers and Electro-Optics (CLEO) CY MAY 22-27, 2005 CL Baltimore, MD AB Terahertz radiation from optically-induced plasmas on metal, semiconductor, and dielectric surfaces is compared to electron-hole plasma radiation from GaAs and Ge. Electro-optic sampling and electric-field probes measure radiated field waveforms and distributions to 0.350 THz. (c) 2005 Optical Society of America. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Rudd, JV (reprint author), Sandia Natl Labs, POB 5800,MS1153, Albuquerque, NM 87185 USA. NR 4 TC 0 Z9 0 U1 0 U2 0 PU OPTICAL SOC AMERICA PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA BN 1-55752-795-4 PY 2005 BP 1948 EP 1950 PG 3 WC Optics SC Optics GA BDP70 UT WOS:000234819902134 ER PT B AU Tsang, T AF Tsang, T GP IEEE TI Multiple-harmonic generation on ZnO nanocrystalline film SO 2005 Conference on Lasers & Electro-Optics (CLEO), Vols 1-3 LA English DT Proceedings Paper CT Conference on Lasers and Electro-Optics (CLEO) CY MAY 22-27, 2005 CL Baltimore, MD ID 3RD-HARMONIC GENERATION AB Second, third, and fifth harmonics to wavelengths of UV and VUV are generated on a thin film of ZnO nanocrystal using a similar to 15-femtosecond Ti:sapphire laser oscillator. The third-harmonic conversion efficiency is one of the highest among all other dielectric materials. A 3(rd)-order interferometric autocorrelation is demonstrated for routine diagnostic of the femtosecond beam and the 5(th)-order autocorrelation is now possible. (c) 2005 Optical Society of America. C1 Brookhaven Natl Lab, Upton, NY 11973 USA. RP Tsang, T (reprint author), Brookhaven Natl Lab, Mail Stop 535B, Upton, NY 11973 USA. NR 6 TC 0 Z9 0 U1 0 U2 0 PU OPTICAL SOC AMERICA PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA BN 1-55752-795-4 PY 2005 BP 2103 EP 2104 PG 2 WC Optics SC Optics GA BDP70 UT WOS:000234819902186 ER PT B AU O'Hara, JF Averitt, RD Taylor, AJ AF O'Hara, JF Averitt, RD Taylor, AJ GP IEEE TI Terahertz surface plasmon polariton generation with metallic gratings and silicon prisms SO 2005 CONFERENCE ON LASERS & ELECTRO-OPTICS (CLEO), VOLS 1-3 LA English DT Proceedings Paper CT Conference on Lasers and Electro-Optics (CLEO) CY MAY 22-27, 2005 CL Baltimore, MD ID PROPAGATION; DISTANCES AB Terahertz time-domain spectroscopy is used to generate surface plasmon polaritons via metallic gratings and silicon prisms. Grating measurements indicate efficient narrowband coupling. Prism measurements show broadband coupling with substantial promise for guided-wave spectroscopy applications. (c) 2005 Optical Society of America C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Los Alamos Natl Lab, MST-10, Los Alamos, NM 87545 USA. EM johara@lanl.gov NR 11 TC 0 Z9 0 U1 0 U2 0 PU OPTICAL SOC AMERICA PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA BN 1-55752-795-4 PY 2005 BP 2275 EP 2277 PG 3 WC Optics SC Optics GA BDP70 UT WOS:000234819902246 ER PT B AU Fortier, TM Bartels, A Diddams, SA AF Fortier, TM Bartels, A Diddams, SA GP IEEE TI A 600 MHz octave-spanning Ti : sapphire laser for optical frequency measurements and comparisons SO 2005 Digest of the LEOS Summer Topical Meetings LA English DT Proceedings Paper CT Digest of the LEOS Summer Topical Meeting CY JUL 25-27, 2005 CL San Diego, CA ID HG-199(+) AB We demonstrate a self-referenced 600 MHz, octave-spanning laser capable of measuring beat signals against atomic optical standards at 563 nm and 534 nm without additional broadening in optical fiber. C1 Los Alamos Natl Lab, Div Phys, Los Alamos, NM 87545 USA. RP Fortier, TM (reprint author), Los Alamos Natl Lab, Div Phys, P-23,Mail Stop H803, Los Alamos, NM 87545 USA. RI Diddams, Scott/L-2819-2013 NR 10 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-8981-6 PY 2005 BP 89 EP 90 PG 2 WC Optics SC Optics GA BCY18 UT WOS:000231847800043 ER PT B AU Edmonds, N Stark, D Davis, J AF Edmonds, N Stark, D Davis, J GP IEEE TI MASS: Mle odular architecture for sensor systems SO 2005 Fourth International Symposium on Information Processing in Sensor Networks LA English DT Proceedings Paper CT 4th International Symposium on Information Processing in Sensor Networks CY APR 25-27, 2005 CL Univ Calif Los Angeles, Los Angeles, CA SP ACM SIGBED, IEEE Signal Proc Soc HO Univ Calif Los Angeles AB Recent advances in low power microprocessors and power storage technology have allowed for the design of a broad range of sensor network platforms. Current sensor network platforms fall into one of two main categories, low power, application specific platforms and full featured general purpose platforms with higher power consumption. The former generally consist of a power-efficient microprocessor and a few application specific resources, while the latter generally have a general purpose processor and a full complement of resources available via a GPIO interface. General purpose platforms are readily available and can be adapted to almost any application but are less efficient with respect to power consumption than application specific solutions. Application specific solutions are extremely efficient and well suited to the problem they are designed for, but are time consuming and expensive to build. MASS is a modular sensor node architecture that enables rapid development of an application specific solution. While not as power-efficient as a completely custom solution, MASS provides application flexibility while being much more efficient than common-off-the-shelf general purpose sensor platforms. Because MASS is modular in both it's software and hardware design, it is straightforward to extend both the software platform and the hardware supporting it to suit an application. What this means is that a custom sensor network solution is now available at a much lower cost, and in a much shorter time-frame than was previously available. This makes a whole new class of sensor network applications feasible. C1 Sandia Natl Labs, Embedded Reasoning Inst, Livermore, CA 94550 USA. RP Edmonds, N (reprint author), Sandia Natl Labs, Embedded Reasoning Inst, Livermore, CA 94550 USA. NR 8 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-9201-9 PY 2005 BP 393 EP 397 PG 5 WC Telecommunications SC Telecommunications GA BCO87 UT WOS:000230452800053 ER PT B AU Burke, GJ White, DA Thompson, CA AF Burke, GJ White, DA Thompson, CA GP IEEE TI Optimization of aperiodic waveguide mode converters SO 2005 IEEE/ACES International Conference on Wireless Communications and Applied Computational Electromagnetics LA English DT Proceedings Paper CT IEEE/ACES International Conference on Wireless Communications and Applied Computational Electromagnetics CY APR 03-07, 2005 CL Honolulu, HI SP IEEE, Appl Computat Electromagnet Soc AB Stepped aperiodic waveguide structures are designed for mode conversion by numerical optimization coupled with a mode matching solver. Several configurations and design goals are evaluated for performance and dimensional tolerances. Results are validated against a FDTD code. C1 Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Burke, GJ (reprint author), Lawrence Livermore Natl Lab, POB 5508, Livermore, CA 94550 USA. NR 4 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-9068-7 PY 2005 BP 156 EP 159 PG 4 WC Engineering, Electrical & Electronic; Telecommunications SC Engineering; Telecommunications GA BDB79 UT WOS:000232402200039 ER PT B AU Pingenot, J Rieben, R White, D AF Pingenot, J Rieben, R White, D GP IEEE TI Full wave analysis of RF signal attenuation in a lossy cave using a high order time domain vector finite element method SO 2005 IEEE/ACES International Conference on Wireless Communications and Applied Computational Electromagnetics LA English DT Proceedings Paper CT IEEE/ACES International Conference on Wireless Communications and Applied Computational Electromagnetics CY APR 03-07, 2005 CL Honolulu, HI SP IEEE, Appl Computat Electromagnet Soc AB We present a computational study of signal propagation and attenuation of a 200 MHz dipole antenna. in a cave environment. The cave is modeled as a straight and lossy random rough wall. To simulate a broad frequency band, the full wave Maxwell equations are solved directly in the time domain via a high order vector finite element discretization using the massively parallel CEM code EMSolve. The simulation is performed for a series of random meshes in order to generate statistical data for the propagation and attenuation properties of the cave environment. Results for the power spectral density and phase of the electric field vector components are presented and discussed. C1 Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Pingenot, J (reprint author), Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. NR 8 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-9068-7 PY 2005 BP 658 EP 661 PG 4 WC Engineering, Electrical & Electronic; Telecommunications SC Engineering; Telecommunications GA BDB79 UT WOS:000232402200161 ER PT B AU Min, MS AF Min, MS GP IEEE TI Discontinuous Galerkin method based on quadrilateral mesh for Maxwell's equations SO 2005 IEEE/ACES International Conference on Wireless Communications and Applied Computational Electromagnetics LA English DT Proceedings Paper CT IEEE/ACES International Conference on Wireless Communications and Applied Computational Electromagnetics CY APR 03-07, 2005 CL Honolulu, HI SP IEEE, Appl Computat Electromagnet Soc DE discontinuous Galerkin method; spectral element discritizations AB Discontinuous Galerkin (DG) methods based on quadrilateral spectral element discritizations are applied to the eletromagnetic wave time-domain simulations in free space. The 2D Maxwell's equations in transverse-magnetic mode are described in conservation form. Numerical flux is used for the communication at the interface between elements and boundary condition. Computational results on the field distribution are demonstrated, including h- and p-convergence in maximum norm with this method. This work is our first step toward two- and three-dimensional nanophotonic simulations using this higher order method. C1 Argonne Natl Lab, Div Math & Comp Sci, Argonne, IL 60439 USA. RP Min, MS (reprint author), Argonne Natl Lab, Div Math & Comp Sci, 9700 S Cass Ave, Argonne, IL 60439 USA. NR 5 TC 0 Z9 0 U1 1 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-9068-7 PY 2005 BP 719 EP 723 PG 5 WC Engineering, Electrical & Electronic; Telecommunications SC Engineering; Telecommunications GA BDB79 UT WOS:000232402200174 ER PT B AU Hussein, YA Spencer, JE AF Hussein, YA Spencer, JE GP IEEE TI Hybrid FDTD analysis for periodic on-chip terahertz (THz) structures SO 2005 IEEE/ACES International Conference on Wireless Communications and Applied Computational Electromagnetics LA English DT Proceedings Paper CT IEEE/ACES International Conference on Wireless Communications and Applied Computational Electromagnetics CY APR 03-07, 2005 CL Honolulu, HI SP IEEE, Appl Computat Electromagnet Soc AB We present electromagnetic analysis and radiation efficiency calculations for on-chip terahertz (THz) structures based on a hybrid, finite-difference, time-domain (HFDTD) technique. The method employs the FDTD technique to calculate S-parameters for one cell of a periodic structure. The transmission ABCD matrix is then estimated and multiplied by itself n times to obtain the n-cell periodic structure ABCD parameters that are then converted back to S-parameters: Validation of the method is carried out by comparing the results of the hybrid technique with FDTD calculations of the entire periodic structure as well as with HFSS which all agree quite well. This procedure reduces the CPU-time and allows efficient design and optimization of periodic THz radiation sources. Future research will involve coupling of Maxwell's equations with a more detailed, physics-based transport model for higher-order effects. C1 Stanford Univ, Stanford Linear Accelerator Ctr, Menlo Pk, CA 94025 USA. RP Hussein, YA (reprint author), Stanford Univ, Stanford Linear Accelerator Ctr, Menlo Pk, CA 94025 USA. NR 4 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-9068-7 PY 2005 BP 797 EP 800 PG 4 WC Engineering, Electrical & Electronic; Telecommunications SC Engineering; Telecommunications GA BDB79 UT WOS:000232402200192 ER PT S AU Miller, J Guetersloh, SB Heilbronn, LH Zeitlin, CJ AF Miller, Jack Guetersloh, Stephen B. Heilbronn, Lawrence H. Zeitlin, Cary J. GP IEEE TI Simulating elements of the space radiation environment on Earth SO 2005 IEEE Aerospace Conference, Vols 1-4 SE IEEE AEROSPACE CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 2005 IEEE Aerospace Conference CY MAR 05-12, 2005 CL Big Sky, MT SP IEEE ID FRAGMENTATION; FE-56 AB Space radiation research is. laying the groundwork for addressing the problem of radiation exposure to humans on extended space missions. This research relies heavily on investigations at ground-based proton and heavy ion accelerators. The interpretation of the data from these experiments depends sensitively on the details of how these heavily ionizing particles deposit their energy in beamline materials and in the instruments used to measure the radiation. We report on the results of measurements with ion beams at several accelerators, including the Bevalac (Lawrence Berkeley National Laboratory), AGS (Brookhaven National Laboratory), HIMAC (National Institute of Radiological Sciences, Chiba, Japan), and the new NASA Space Radiation Laboratory (NSRL) at Brookhaven. These measurements illustrate some of the critical features of heavy charged particle interactions. C1 Lawrence Berkeley Lab, Life Sci Div, Berkeley, CA 94720 USA. RP Miller, J (reprint author), Lawrence Berkeley Lab, Life Sci Div, Berkeley, CA 94720 USA. RI Heilbronn, Lawrence/J-6998-2013 OI Heilbronn, Lawrence/0000-0002-8226-1057 NR 12 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1095-323X BN 0-7803-8869-0 J9 AEROSP CONF PROC PY 2005 BP 698 EP 703 PG 6 WC Engineering, Aerospace SC Engineering GA BEN93 UT WOS:000238379000066 ER PT S AU Porter, R Chakrabarti, C Harvey, N Kenyon, G AF Porter, R. Chakrabarti, C. Harvey, N. Kenyon, G. GP IEEE TI A scalable learning system for video recognition SO 2005 IEEE Aerospace Conference, Vols 1-4 SE IEEE AEROSPACE CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 2005 IEEE Aerospace Conference CY MAR 05-12, 2005 CL Big Sky, MT SP IEEE AB Learning has become an essential part of many image and video processing systems, but it is not often used as an end-to-end solution. Some of the most successful demonstrations of end-to-end learning have been with convolutional, or shared weight networks. We are interested in how this approach can scale and have developed a flexible framework for implementing and training large scale convolutional networks called Harpo. We present an overview of the Harpo framework and describe a multilevel learning strategy used to optimize convolutional networks for particular features of interest in video data streams. Harpo is designed to exploit reconfigurable hardware to accelerate massively parallel convolutional network components and achieve real-time processing speeds. In this paper we present initial software experiments which use the system to segment exhaust plumes coming from military vehicles in Unmanned Aerial Vehicle video data. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Porter, R (reprint author), Los Alamos Natl Lab, Los Alamos, NM 87545 USA. NR 13 TC 0 Z9 0 U1 0 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1095-323X BN 0-7803-8869-0 J9 AEROSP CONF PROC PY 2005 BP 2228 EP 2235 PG 8 WC Engineering, Aerospace SC Engineering GA BEN93 UT WOS:000238379001113 ER PT S AU Ericson, MN Hasanuzzaman, M Terry, SC Britton, CL Ohme, B Frank, SS Richmond, JA Blalock, BJ AF Ericson, M. N. Hasanuzzaman, M. Terry, S. C. Britton, C. L. Ohme, B. Frank, S. S. Richmond, J. A. Blalock, B. J. GP IEEE TI 1/f noise and DC characterization of partially depleted SOIN- and P-MOSFETs from 20 degrees C-250 degrees C SO 2005 IEEE Aerospace Conference, Vols 1-4 SE IEEE AEROSPACE CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 2005 IEEE Aerospace Conference CY MAR 05-12, 2005 CL Big Sky, MT SP IEEE ID CMOS; DESIGN AB A summary of measured small-signal parameters and low frequency noise characterized over temperature is presented for N- and P- MOSFETs fabricated in a partially depleted SOI 0.8-mu m process. Small-signal dc parameters critical in analog circuit design are reported including device transconductance efficiency (g(m)/I-d), output resistance (r(ds)), and threshold voltage (V-t). These parameters are summarized as a function of both gate length (0.8 mu m, 2.0 mu m, 5.0 mu m, and 20 mu m) and temperature (20 degrees to 300 degrees C). Noise characterization of these devices is also presented with an emphasis on flicker noise over temperature (20 degrees to 250 degrees C). Data is presented in terms of both drain current and inversion coefficient, where appropriate. Use of this information provides the designer with an excellent tool for estimating analog circuit performance in applications. where wide temperature range performance is required . C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Ericson, MN (reprint author), Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RI Ericson, Milton/H-9880-2016 OI Ericson, Milton/0000-0002-6628-4865 NR 11 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1095-323X BN 0-7803-8869-0 J9 AEROSP CONF PROC PY 2005 BP 2661 EP 2673 PG 13 WC Engineering, Aerospace SC Engineering GA BEN93 UT WOS:000238379002048 ER PT S AU Amidan, BG Ferryman, TA AF Amidan, Brett G. Ferryman, Thomas A. GP IEEE TI Atypical event and typical pattern detection within complex systems SO 2005 IEEE Aerospace Conference, Vols 1-4 SE IEEE AEROSPACE CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 2005 IEEE Aerospace Conference CY MAR 05-12, 2005 CL Big Sky, MT SP IEEE AB Algorithms(1,2) have been developed to find typical patterns and atypical events within complex data systems. A software package called The Morning Report was developed in which these algorithms were applied to digital flight data for commercial airlines. These systems contain many sets of data with hundreds of variables being measured over time, generally resulting in many gigabytes of data to be analyzed. Using statistical and mathematically based algorithms this software identifies atypical flights as well as which flight parameters and which flight phases are atypical. These algorithms also cluster the flights into a finite number of distinct patterns. This clustering allows the flight analyst to focus on atypical flights as well as the typical flight patterns discovered, removing the need to explore each flight separately. The Morning Report software was designed to run each night, producing a report in the morning. This report identifies the characteristics of only the newly added flights, but it uses data from previous flights to help establish the baseline. The report consists of interactive analysis tools that allow for plotting of significant flight parameters for each atypical flight as compared to the typical flights, as well as plots that contrast a flight pattern of interest to any other flight pattern or to all patterns combined. The approach, algorithms, and software are extendable to a large variety of domains to identify the typical patterns, atypical reports, and provide a plain English explanation. C1 Battelle Pacific NW Div, Richland, WA 99352 USA. RP Amidan, BG (reprint author), Battelle Pacific NW Div, 902 Battelle Blvd, Richland, WA 99352 USA. NR 3 TC 8 Z9 8 U1 0 U2 2 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1095-323X BN 0-7803-8869-0 J9 AEROSP CONF PROC PY 2005 BP 3620 EP 3631 DI 10.1109/AERO.2005.1559667 PG 12 WC Engineering, Aerospace SC Engineering GA BEN93 UT WOS:000238379003023 ER PT S AU Zuffranieri, JV Robinson, DG AF Zuffranieri, Jason V. Robinson, David G. GP IEEE TI A Bayesian approach for health monitoring of critical systems SO 2005 IEEE Aerospace Conference, Vols 1-4 SE IEEE AEROSPACE CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 2005 IEEE Aerospace Conference CY MAR 05-12, 2005 CL Big Sky, MT SP IEEE AB Bayesian medical(1) monitoring(2) is a concept based on using real-time performance-related data to make statistical predictions about a patient's future health. The following paper discusses the fundamentals behind the medical monitoring concept and the application to monitoring the health of nuclear reactors. Necessary assumptions are discussed regarding distributions and failure-rate calculations. A simple example is performed to illustrate the effectiveness of the methods. The methods perform very well for the thirteen subjects in the example, with a clear failure sequence identified for eleven of the subjects. C1 Sandia Natl Labs, Risk & Raliabil Anal, Albuquerque, NM 87185 USA. RP Zuffranieri, JV (reprint author), Sandia Natl Labs, Risk & Raliabil Anal, POB 5800, Albuquerque, NM 87185 USA. NR 3 TC 0 Z9 0 U1 0 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1095-323X BN 0-7803-8869-0 J9 AEROSP CONF PROC PY 2005 BP 3641 EP 3646 PG 6 WC Engineering, Aerospace SC Engineering GA BEN93 UT WOS:000238379003025 ER PT S AU Amidan, BG Ferryman, TA Cooley, SK AF Amidan, Brett G. Ferryman, Thomas A. Cooley, Scott K. GP IEEE TI Data outlier detection using the Chebyshev theorem SO 2005 IEEE Aerospace Conference, Vols 1-4 SE IEEE AEROSPACE CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 2005 IEEE Aerospace Conference CY MAR 05-12, 2005 CL Big Sky, MT SP IEEE AB During data collection and analysis(1,2), it is often necessary to identify and possibly remove outliers that exist. An objective method for identifying outliers to be removed is critical. Many automated outlier detection methods are available. However, many are limited by assumptions of a distribution or require upper and lower predefined boundaries in which the data should exist. If there is a known distribution for the data, then using that distribution can aid in finding outliers. Often, a distribution is not known, or the experimenter does not want to make an assumption about a certain distribution. Also, enough information may not exist about a set of data to be able to determine reliable upper and lower boundaries. For these cases, an outlier detection method, using the empirical data and based upon Chebyshev's inequality, was formed. This method allows for detection of multiple outliers, not just one at a time. This method also assumes that the data are independent measurements and that a relatively small percentage of outliers is contained in the data. Chebyshev's inequality gives a bound of what percentage of the data falls outside of k standard deviations from the mean. This calculation holds no assumptions about the distribution of the data. If the data are known to be unimodal without a known distribution, then the method can be improved by using the unimodal Chebyshev inequality. The Chebyshev Outlier Detection method uses the Chebyshev inequality to calculate upper and lower outlier detection limits. Data values that are not within the range of the upper and lower limits would be considered data outliers. Outliers could be due to erroneous data or could indicate that the data are correct but highly unusual. This algorithm does not ascertain the reason for the outlier; it identifies potential outlier data, allowing for domain experts to investigate the cause. C1 Battelle Pacific NW Div, Richland, WA 99352 USA. RP Amidan, BG (reprint author), Battelle Pacific NW Div, 902 Battelle Blvd, Richland, WA 99352 USA. NR 1 TC 24 Z9 26 U1 0 U2 2 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1095-323X BN 0-7803-8869-0 J9 AEROSP CONF PROC PY 2005 BP 3814 EP 3819 DI 10.1109/AERO.2005.1559688 PG 6 WC Engineering, Aerospace SC Engineering GA BEN93 UT WOS:000238379003044 ER PT S AU Love, LJ Yeary, LW Moon, JW Phelps, TJ Rondinone, AJ AF Love, LJ Yeary, LW Moon, JW Phelps, TJ Rondinone, AJ GP IEEE TI Characterization of bio-synthesized magnetic nanoparticles SO 2005 IEEE/ASME INTERNATIONAL CONFERENCE ON ADVANCED INTELLIGENT MECHATRONICS, VOLS 1 AND 2 SE IEEE ASME International Conference on Advanced Intelligent Mechatronics LA English DT Proceedings Paper CT IEEE/ASME International Conference on Advanced Intelligent Mechatronics CY JUL 24-28, 2005 CL Monterey, CA SP IEEE, Amer Soc Mech Engineers ID BACTERIA; FERROFLUIDS; PARTICLES AB Magnetic nanoparticles have potential utility in a variety of applications ranging from ferrofluids to highly sensitive transduction mechanisms for monitoring and controlling biological activities at the molecular level. This paper describes a novel methodology for bacterial synthesis of a wide range of magnetite-based magnetic nanoparticles. First, this approach is highly scalable and low cost enabling production of large volumes of nanoparticles. Second, like the chemical co-precipitation technique, biologically synthesized materials have the ability to dope magnetite with a wide range of elements enabling fine control over magnetic and thermal properties of the particles. Third, unlike chemical co-precipitation techniques which restrict particle sizes below 20 tint, bacterial synthesis enables control of particle sizes from 10 nm to 100 nm. Finally, we show that some forms of the bio-synthesized materials have a significantly higher saturation magnetization than typical chemically synthesized materials. C1 Oak Ridge Natl Lab, Robot & Energet Syst Grp, Oak Ridge, TN 37831 USA. RP Love, LJ (reprint author), Oak Ridge Natl Lab, Robot & Energet Syst Grp, Oak Ridge, TN 37831 USA. RI Moon, Ji-Won/A-9186-2011; phelps, tommy/A-5244-2011; Rondinone, Adam/F-6489-2013 OI Moon, Ji-Won/0000-0001-7776-6889; Rondinone, Adam/0000-0003-0020-4612 NR 28 TC 0 Z9 0 U1 0 U2 3 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 2159-6255 BN 0-7803-9046-6 J9 IEEE ASME INT C ADV PY 2005 BP 111 EP 115 PG 5 WC Automation & Control Systems; Computer Science, Artificial Intelligence; Engineering, Electrical & Electronic; Engineering, Mechanical; Robotics SC Automation & Control Systems; Computer Science; Engineering; Robotics GA BCZ07 UT WOS:000232003500020 ER PT B AU Havre, SL Webb-Robertson, BJ Shah, A Posse, C Gopalan, B Brockman, FJ AF Havre, SL Webb-Robertson, BJ Shah, A Posse, C Gopalan, B Brockman, FJ GP IEEE Comp Soc TI Bioinformatic insights from metagenomics through visualization SO 2005 IEEE Computational Systems Bioinformatics Conference, Proceedings LA English DT Proceedings Paper CT IEEE Computational Systems Bioinformatics Conference CY AUG 08-11, 2005 CL Stanford, CA SP IEEE Comp Soc Tech Comm Bioinformat DE bioinformatics; visualization; metagenomics; categorical; nominal AB Cutting-edge biological and bioinformatics research seeks a systems perspective through the analysis of multiple types of high-throughput and other experimental data for the same sample. Systems-level analysis requires the integration and fusion of such data, typically through advanced statistics and mathematics. Visualization is a complementary computational approach that supports integration and analysis of complex data or its derivatives. We present a bioinformatics visualization prototype, Juxter, which depicts categorical information derived from or assigned to these diverse data for the purpose of comparing patterns across categorizations. The visualization allows users to easily, discern correlated and anomalous patterns in the data. These patterns, which might not be detected automatically by, algorithms, may, reveal valuable information leading to insight and discovery. We describe the visualization and interaction capabilities and demonstrate its utility in a new field, metagenomics, which combines molecular biology and genetics to identify and characterize genetic material from multi-species microbial samples. C1 Pacific NW Natl Lab, Richland, WA 99352 USA. RP Havre, SL (reprint author), Pacific NW Natl Lab, Richland, WA 99352 USA. NR 21 TC 6 Z9 8 U1 0 U2 2 PU IEEE COMPUTER SOC PI LOS ALAMITOS PA 10662 LOS VAQUEROS CIRCLE, PO BOX 3014, LOS ALAMITOS, CA 90720-1264 USA BN 0-7695-2344-7 PY 2005 BP 341 EP 350 DI 10.1109/CSB.2005.19 PG 10 WC Biotechnology & Applied Microbiology; Computer Science, Interdisciplinary Applications; Genetics & Heredity SC Biotechnology & Applied Microbiology; Computer Science; Genetics & Heredity GA BCX83 UT WOS:000231800100038 PM 16447991 ER PT S AU Little, C Peters, R AF Little, C Peters, R GP IEEE TI Simulated mobile self-location using 3D range sensing and an a-priori map SO 2005 IEEE International Conference on Robotics and Automation (ICRA), Vols 1-4 SE IEEE INTERNATIONAL CONFERENCE ON ROBOTICS AND AUTOMATION LA English DT Proceedings Paper CT IEEE International Conference on Robotics and Automation (ICRA) CY APR 18-22, 2005 CL Barcelona, SPAIN SP IEEE DE mobile robot navigation; localization AB Self-location is a critical component of unmanned ground vehicle operation. While GPS has met this need for many applications, there are others, indoors and outdoors, where GPS is not available or reliable. This paper discusses the investigation of a method to self-locate using an onboard 3D range sensor, when a 3D map of the environment is available. We have examined the performance in terms of what is needed for data coverage and terrain types. Localization is accomplished through surface fitting. Surface fitting is an important component of Simultaneous Localization and Mapping (SLAM) for 3D terrains. Three environments were chosen for testing, including a hilly desert scene, an indoor corridor scene, and a forest scene. A simulated 3D range sensor was used to scan models corresponding to these three environments. Various parameters were modified to identify strong and weak points in the scheme. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Little, C (reprint author), Sandia Natl Labs, Albuquerque, NM 87185 USA. NR 11 TC 1 Z9 1 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1050-4729 BN 0-7803-8914-X J9 IEEE INT CONF ROBOT PY 2005 BP 1459 EP 1464 PG 6 WC Robotics SC Robotics GA BDU48 UT WOS:000235460101042 ER PT B AU Daily, MR AF Daily, MR GP IEEE TI A structured process for transitioning new technology into fieldable products SO 2005 IEEE International Engineering Management Conference, Vols 1 and 2 LA English DT Proceedings Paper CT IEEE International Engineering Management Conference CY SEP 11-13, 2005 CL St Johns, CANADA SP IEEE Engn Management Soc, IEE Management Profess Network, IEEE Newfoundland & Labrador Sect, IEEE Canada ID CUSTOMER AB Through insight and experience Sandia National Laboratories has developed and refined a structured process to realize complex, heterogeneously integrated microsystem products. We have identified major obstacles to successful realization of microsystem products and have formalized a process to maximize development success and product realization. Over the last seven years Sandia's complex microsystems product development business has grown by an annualized rate of 40% per year. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. NR 15 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-9139-X PY 2005 BP 77 EP 81 PG 5 WC Engineering, Multidisciplinary; Management SC Engineering; Business & Economics GA BDV17 UT WOS:000235633100016 ER PT B AU Banerjee, B AF Banerjee, B GP IEEE TI Applying EVM principles to Tevatron Beam Position Monitor project SO 2005 IEEE International Engineering Management Conference, Vols 1 and 2 LA English DT Proceedings Paper CT IEEE International Engineering Management Conference CY SEP 11-13, 2005 CL St Johns, CANADA SP IEEE Engn Management Soc, IEE Management Profess Network, IEEE Newfoundland & Labrador Sect, IEEE Canada AB At Fermi National Accelerator Laboratory (Fermilab), the Tevatron high energy particle collider must meet the increasing scientific demand of higher beam luminosity. To achieve this higher luminosity goal, U. S. Department of Energy (DOE) sponsored a major upgrade of capabilities of Fermilab's accelerator complex that spans five years and costs over fifty million dollars. Tevatron Beam Position Monitor (BPM) system upgrade is a part of this project, generally called RunII upgrade project. Since the purpose of the Tevatron collider is to detect the smashing of proton and anti-protons orbiting the circular accelerator in opposite directions, capability to detect positions of both protons and antiprotons at a high resolution level is a desirable functionality of the monitoring system. The original system was installed during early 1980s, along with the original construction of the Tevatron. However, electronic technology available in 1980s did not allow for the detection of significantly smaller resolution of antiprotons. The objective of the upgrade project is to replace the existing BPM system with a new system utilizing capabilities of modern electronics enhanced by a front-end software driven by a real-time operating software. The new BPM system is designed to detect both protons and antiprotons with increased resolution of up to an order of magnitude. The new system is capable of maintaining a very high-level of data integrity and system reliability. The system consists of 27 VME crates installed at 27 service buildings around the Tevatron ring servicing 236 beam position monitors placed underground, inside the accelerator tunnel. Each crate consists of a single Timing Generator Fanout module, custom made by Fermilab staff, one MVME processor card running VxWorks 5.5, multiple Echotek Digital Receiver boards complimented by custom made Filter Board. The VxWorks based front-end software communicates with the Main Accelerator Control software via a special-purpose network called ACNET. New software algorithms are designed to decouple antiproton signals from the mixed proton and antiproton signals. Along with many technical challenges, it was necessary to meet various project management challenges as well. Since 1999, U.S. Department of Energy (DOE) has taken various measures to improve project management of the acquisition of capital assets. U.S. National Laboratories, with their charter of driving scientific efforts of DOE, have put into place project management methodologies recommended by DOE. One of the outcomes of such measures is the deployment of a formal project management system for large projects. This recommendation is detailed in the DOE order M 413.3. The Tevatron BPM Upgrade project, as a part of the Run 11 Upgrade project, used the methodology prescribed in the DOE order. Particular attention was concentrated on the performance management since the accelerator complex will be in operation for several years in the future. Because of the cost and schedule constraints on the project, it was also important to deploy Earned Value Management (EVM) methodology recommended by the DOE orders. In this paper, we discuss how the earned value project management methodology was implemented using a work breakdown structure based on system life cycle phases. Tevatron BPM upgrade project, now nearing completion, has been a significant learning experience for the organization. We discuss important lessons learned from the phase-dependant earned value management project model. Hardware and software co-design along with simultaneously developed highprecision algorithm was a major challenge. Since formal project management process is not fully ingrained into the cultural environment of the laboratory dedicated to highenergy physics research, we also gained significant experience with the planning for schedule and cost in this environment. We also present a set of earned value project management data that may serve as a baseline for future projects. C1 Fermilab Natl Accelerator Lab, Batavia, IL 60510 USA. NR 3 TC 0 Z9 0 U1 0 U2 2 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-9139-X PY 2005 BP 589 EP 593 PG 5 WC Engineering, Multidisciplinary; Management SC Engineering; Business & Economics GA BDV17 UT WOS:000235633100120 ER PT B AU Tanner, DM Walraven, JA Dugger, MT Parson, TB AF Tanner, DM Walraven, JA Dugger, MT Parson, TB GP IEEE TI Accelerating aging failures in MEMS devices SO 2005 IEEE INTERNATIONAL RELIABILITY PHYSICS SYMPOSIUM PROCEEDINGS - 43RD ANNUAL SE INTERNATIONAL RELIABILITY PHYSICS SYMPOSIUM LA English DT Proceedings Paper CT 43rd Annual IEEE International Reliability Physics Symposium CY APR 17-21, 2005 CL San Jose, CA SP IEEE Electron Devices Soc, IEEE Reliabil Soc DE MEMS; MEMS dormant storage; MEMS; accelerated life tests; VSAM degradation ID SELF-ASSEMBLED MONOLAYERS; ADHESION AB The feasibility of using temperature and humidity to age vapor-deposited SAM-coated electrostatic-actuated MEMS devices with contacting surfaces was determined. Failures were dependent on both temperature and humidity. The trend indicated longer life at both lower temperatures and lower humidity levels. Using cantilever beams, measurements reveal degradation of the VSAM surface coating when stressed at 300 degrees C with controlled humidity environments of 500 and 2000 ppmv. In particular, we have seen the surface adhesion change for these beams stressed at 300 degrees C for time intervals of 10, 24, 50, 100, and 200 hours. However, there is no measurable change after 2 hours. The higher humidity case promotes the same surface adhesion change in a factor of ten less time. The complex MEMS devices tested followed the same trends as the beam test structures. We definitely observe a failure of the MEMS devices due to the environment with most failures occurring at 300 degrees C and some failures at 200 degrees C. These failures are due to an adhesion site in the hub of the load gear where the typical gap is 0.3 mu m. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Tanner, DM (reprint author), Sandia Natl Labs, POB 5800,MS 1310, Albuquerque, NM 87185 USA. EM tannerdm@sandia.gov NR 11 TC 6 Z9 6 U1 0 U2 3 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-8803-8 J9 INT REL PHY PY 2005 BP 317 EP 324 DI 10.1109/RELPHY.2005.1493105 PG 8 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA BCM84 UT WOS:000230058000052 ER PT B AU Webster, JR Dyck, CW Nordquist, CD Felix, JA Shaneyfelt, M Schwank, JR Banks, JC AF Webster, JR Dyck, CW Nordquist, CD Felix, JA Shaneyfelt, M Schwank, JR Banks, JC GP IEEE TI Process-induced trapping of charge in PECVD dielectrics for RF MEMS capacitive switches SO 2005 IEEE INTERNATIONAL RELIABILITY PHYSICS SYMPOSIUM PROCEEDINGS - 43RD ANNUAL SE INTERNATIONAL RELIABILITY PHYSICS SYMPOSIUM LA English DT Proceedings Paper CT 43rd Annual IEEE International Reliability Physics Symposium CY APR 17-21, 2005 CL San Jose, CA SP IEEE Electron Devices Soc, IEEE Reliabil Soc DE RF MEMS; capacitive switch; dielectric charging; charge metrology; plasma damage ID DEPOSITED SILICON-NITRIDE; DIOXIDE AB Charge-induced failure is recognized as the primary reliability issue in RF MEMS capacitive switches. In this paper, we present a simplified method for quantifying the effects of process-induced charging of plasma-enhanced, chemical vapor deposition (PECVD) dielectrics commonly used in the fabrication of these devices. Using this method, based on capacitance-voltage (C-V) measurements of MIS (metal-insulator-semiconductor) devices, we examined the charge behavior of PECVD silicon dioxide, nitride, and oxynitride films deposited at substrate temperatures of 250-350 degrees C. The results show that these PECVD dielectrics contain sufficient incorporated charge in their as-deposited state to inhibit reliable switch operation. Post-deposition, plasma-induced and electrical stresses were also found to negatively impact the charge behavior of these films. However, after an initial period of instability, chemical analysis showed film composition to be highly consistent, both across deposition runs and with post-deposition stress. Of the four candidate dielectrics considered, silicon oxynitride exhibited the least charge incorporation for as-deposited films and also the least sensitivity to electrical stress. However, it showed significant sensitivity to plasma-induced stress after deposition, possibly caused by damage to the film leading to increased passivation of active charge trapping sites. We conclude by presenting potential techniques for mitigation of the incorporated charge observed in these PECVD dielectrics. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Webster, JR (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. EM jrwebst@sandia.gov NR 15 TC 8 Z9 8 U1 0 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-8803-8 J9 INT REL PHY PY 2005 BP 330 EP 336 DI 10.1109/RELPHY.2005.1493107 PG 7 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA BCM84 UT WOS:000230058000054 ER PT B AU Okandan, M Draper, B Wessendorf, K Pearson, S Young, R AF Okandan, M Draper, B Wessendorf, K Pearson, S Young, R GP IEEE TI Retinal implant electrode arrays with 10V SOICMOS circuitry SO 2005 IEEE International SOI Conference, Proceedings LA English DT Proceedings Paper CT IEEE International SOI Conference CY OCT 03-06, 2005 CL Honolulu, HI SP IEEE Electron Devices Soc C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Okandan, M (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-9212-4 PY 2005 BP 198 EP 199 DI 10.1109/SOI.2005.1563587 PG 2 WC Engineering, Electrical & Electronic; Physics, Applied; Physics, Condensed Matter SC Engineering; Physics GA BDQ53 UT WOS:000234923200071 ER PT S AU Donde, V Hiskens, IA AF Donde, V Hiskens, IA GP IEEE TI Observed hybrid oscillations in an electrical distribution system SO 2005 IEEE INTERNATIONAL SYMPOSIUM ON CIRCUITS AND SYSTEMS (ISCAS), VOLS 1-6, CONFERENCE PROCEEDINGS SE IEEE International Symposium on Circuits and Systems LA English DT Proceedings Paper CT IEEE International Symposium on Circuits and Systems (ISCAS) CY MAY 23-26, 2005 CL Kobe, JAPAN SP IEEE Circuits & Syst Soc, Sci Council Japan, Inst Elect, Informat & Commun Engineers, Inst Elect Engineers Japan, Informat Proc Soc Japan AB Slow oscillations, with a period of around 15 minutes, were observed in an 11kV electrical distribution system. Investigations determined that the oscillations were a result of interactions between tap-changing transformers and switched capacitors. Analysis required a hybrid systems framework, due to the non-smooth (switched) nature of these interactions. It was found that the oscillations could be suppressed by adjusting the lower limit of the capacitor deadband. A grazing bifurcation separated oscillatory from steady-state behaviour. C1 Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. RP Donde, V (reprint author), Lawrence Berkeley Natl Lab, 1 Cyclotron Rd, Berkeley, CA 94720 USA. EM VDonde@lbl.gov; hiskens@engr.wisc.edu NR 11 TC 0 Z9 0 U1 0 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 0271-4302 BN 0-7803-8834-8 J9 IEEE INT SYMP CIRC S PY 2005 BP 4179 EP 4182 DI 10.1109/ISCAS.2005.1465552 PG 4 WC Engineering, Electrical & Electronic SC Engineering GA BCZ06 UT WOS:000232002404002 ER PT B AU Bardeen, M Gilbert, E Jordan, T Nepywoda, P Quigg, E Wilde, M Zhao, Y AF Bardeen, M Gilbert, E Jordan, T Nepywoda, P Quigg, E Wilde, M Zhao, Y GP IEEE TI The QuarkNet/grid collaborative learning e-Lab SO 2005 IEEE International Symposium on Cluster Computing and the Grid, Vols 1 and 2 LA English DT Proceedings Paper CT 5th IEEE International Symposium on Cluster Computing and the Grid (CCGrid 2005) CY MAY 09-12, 2005 CL Cardiff, WALES SP IEEE Comp Soc, AMD, hp, IBM, Cardiff Caerdydd, COMPUSYS, Cardiff Univ, Cybula, Foundry Networks, GRIDtoday, BLC, MCNC, Oracle, Sun Q Associates, WDA ID COSMIC-RAY DETECTORS AB We describe a case study that uses grid computing techniques to support the collaborative learning of high school students investigating cosmic rays. Students gather and upload science data to our e-Lab portal. They explore those data using techniques from the GriPhyN collaboration. These techniques include virtual data transformations, workflows, metadata cataloging and indexing, data product provenance and persistence, as well as job planners. Students use web browsers and a custo, interface that extends the GriPhYN Chiron portal to perform all of these tasks. They share results in the form of online posters and ask each other questions in this asynchronous environment. Students can discover and extend the research of other students, modeling the processes of modern large-scale scientific collaborations. Also, the e-Lab portal provides tools for teachers to guide student work throughout an investigation. C1 Fermilab Natl Accelerator Lab, Batavia, IL 60510 USA. RP Bardeen, M (reprint author), Fermilab Natl Accelerator Lab, Batavia, IL 60510 USA. NR 14 TC 1 Z9 1 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-9074-1 PY 2005 BP 27 EP 34 PG 8 WC Computer Science, Theory & Methods SC Computer Science GA BCW26 UT WOS:000231526600004 ER PT B AU Schwidder, J Talbott, T Myers, J AF Schwidder, J Talbott, T Myers, J GP IEEE TI Bootstrapping to a semantic grid SO 2005 IEEE International Symposium on Cluster Computing and the Grid, Vols 1 and 2 LA English DT Proceedings Paper CT 5th IEEE International Symposium on Cluster Computing and the Grid (CCGrid 2005) CY MAY 09-12, 2005 CL Cardiff, WALES SP IEEE Comp Soc, AMD, hp, IBM, Cardiff Caerdydd, COMPUSYS, Cardiff Univ, Cybula, Foundry Networks, GRIDtoday, BLC, MCNC, Oracle, Sun Q Associates, WDA AB The Scientific Annotation Middleware (SAM) is a set of components and - services that enable researchers, applications, problem solving environments (PSE) and software agents to create metadata and annotations about data objects and document the semantic relationships between them. Developed starting in 2001, SAM allows applications to encode metadata within files or to manage metadata at the level of individual relationships as desired. SAM then provides mechanisms to expose metadata and relationships encoded either way as WebDAV properties. In this paper, we report on work to further map this metadata into RDF and discuss the role of middleware such as SAM in bridging between traditional and semantic grid applications. C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Schwidder, J (reprint author), Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. OI Myers, James/0000-0001-8462-650X NR 11 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-9074-1 PY 2005 BP 176 EP 181 PG 6 WC Computer Science, Theory & Methods SC Computer Science GA BCW26 UT WOS:000231526600023 ER PT B AU Sulakhe, D Rodriguez, A D'Souza, M Wilde, M Nefedova, V Foster, I Maltsev, N AF Sulakhe, D Rodriguez, A D'Souza, M Wilde, M Nefedova, V Foster, I Maltsev, N GP IEEE TI GNARE: An environment for grid-based high-throughput genome analysis SO 2005 IEEE INTERNATIONAL SYMPOSIUM ON CLUSTER COMPUTING AND THE GRID, VOLS 1 AND 2 LA English DT Proceedings Paper CT 5th IEEE International Symposium on Cluster Computing and the Grid (CCGrid 2005) CY MAY 09-12, 2005 CL Cardiff, WALES SP IEEE Comp Soc, AMD, hp, IBM, Cardiff Caerdydd, COMPUSYS, Cardiff Univ, Cybula, Foundry Networks, GRIDtoday, BLC, MCNC, Oracle, Sun Q Associates, WDA ID DATABASE; PROTEIN; ANNOTATION; RESOURCE; BLAST; FASTA AB Recent progress in genomics and experimental biology has brought exponential growth of the biological information available for computational analysis in public genomics databases. However, applying the potentially enormous scientific value of this information to the understanding of biological systems requires computing and data storage technology of an unprecedented scale. The Grid, with its aggregated and distributed computational and storage infrastructure, offers an ideal platform for high-throughput bioinformatics analysis. To leverage this we have developed the Genome Analysis Research Environment (GNARE) - a scalable computational system for the high-throughput analysis of genomes, which provides an integrated database and computational backend for data-driven bioinformatics applications. GNARE efficiently automates the major steps of genome analysis including acquisition of data from multiple genomic databases; data analysis by a diverse set of bioinformatics tools; and storage of results and annotations. High-throughput computations in GNARE are performed using distributed heterogeneous Grid computing resources such as Grid2003, TeraGrid, and the DOE Science Grid. Multi-step genome analysis workflows involving massive data processing, the use of application-specific tools and algorithms and updating of an integrated database to provide interactive web access to results are all expressed and controlled by a "virtual data" model which transparently maps computational workflows to distributed Grid resources. This paper describes how Grid technologies such as Globus, Condor, and the Gryphyn Virtual Data System were applied in the development of GNARE. It focuses on our approach to Grid resource allocation and to the use of GNARE as a computational framework for the development of bioinformatics applications. C1 Argonne Natl Lab, Div Math & Comp Sci, Argonne, IL 60439 USA. RP Argonne Natl Lab, Div Math & Comp Sci, 9700 S Cass Ave, Argonne, IL 60439 USA. NR 28 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-9074-1 PY 2005 BP 455 EP 462 PG 8 WC Computer Science, Theory & Methods SC Computer Science GA BCW26 UT WOS:000231526600057 ER PT B AU Ross, R Latham, R Gropp, W Thakur, R Toonen, B AF Ross, R Latham, R Gropp, W Thakur, R Toonen, B GP IEEE TI Implementing MPI-IO atomic mode without file system support SO 2005 IEEE INTERNATIONAL SYMPOSIUM ON CLUSTER COMPUTING AND THE GRID, VOLS 1 AND 2 LA English DT Proceedings Paper CT 5th IEEE International Symposium on Cluster Computing and the Grid (CCGrid 2005) CY MAY 09-12, 2005 CL Cardiff, WALES SP IEEE Comp Soc, AMD, hp, IBM, Cardiff Caerdydd, COMPUSYS, Cardiff Univ, Cybula, Foundry Networks, GRIDtoday, BLC, MCNC, Oracle, Sun Q Associates, WDA AB The ROMIO implementation of the MPI-IO standard provides a portable infrastructure for use on top of any number of different underlying storage targets. These different targets vary widely in their capabilities, and in some cases, additional effort is needed within ROMIO to support the complete MPI-IO semantics. One aspect of the interface that can be problematic to implement is the MPI-IO atomic mode. This mode requires enforcing strict consistency semantics. For some file systems, native locks may be used to enforce these semantics, but not all file systems have lock support. In this work, we describe two algorithms for implementing efficient mutex locks using MPI-1 and MPI-2 capabilities. We then show how these algorithms may be used to implement a portable MPI-IO atomic mode for ROMIO. We evaluate the performance of these algorithms and show that they impose little additional overhead on the system. Because of the low-overhead nature of these algorithms, they are likely useful in a variety of situations where distributed locks are needed in the MPI-2 environment. C1 Argonne Natl Lab, Div Math & Comp Sci, Argonne, IL 60439 USA. RP Argonne Natl Lab, Div Math & Comp Sci, 9700 S Cass Ave, Argonne, IL 60439 USA. EM rross@mcs.anl.gov; robl@mcs.anl.gov; gropp@mcs.anl.gov; thakur@mcs.anl.gov; toonen@mcs.anl.gov OI Latham, Rob/0000-0002-5285-6375; Gropp, William/0000-0003-2905-3029 NR 12 TC 1 Z9 1 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-9074-1 PY 2005 BP 1135 EP 1142 PG 8 WC Computer Science, Theory & Methods SC Computer Science GA BCW26 UT WOS:000231526600142 ER PT B AU Silvers, KL Burghard, BJ Skorpik, JR Clark, DA AF Silvers, KL Burghard, BJ Skorpik, JR Clark, DA GP IEEE TI Implementation of an electronic media security system SO 2005 IEEE International Workshop on Measurement Systems for Homeland Security, Contraband Detection & Personal Safety LA English DT Proceedings Paper CT IEEE International Workshop on Measurement Systems for Homeland Security, Contraband Detection and Personal Safety CY MAR 29-30, 2005 CL Orlando, FL SP IEEE DE electronic media security system (EMSS); classified removable electronic media (CREM); central alarm system (CAS); iButtons; central reporting station AB Recent security lapses within the Department of Energy Laboratories prompted the establishment and implementation of additional procedures and training for operations involving classified removable electronic media (CREM) storage. In addition, the definition of CREM has been expanded and the number of CREM has increased significantly. Procedures now require that all CREM be inventoried and accounted for on a weekly basis. Weekly inventories consist of a physical comparison of each item against the reportable inventory listing. Securing and accounting for CREM is a continuous challenge for existing security systems. To address the challenge, Pacific Northwest National Laboratory (PNNL) has developed an automated Electronic Media Security System (EMSS) for a weekly CREM inventory collection and reporting system. The EMSS approach is to tag the CREM with an electronically readable unique identification code and automatically collect data on the inventory in each security container or vault at a user-defined interval and upon detection of an access event; thus eliminating the need for hand-written inventory sheets while allowing automated transfer of the collected inventory data to an electronic reporting system. An electronic log of CREM access events is maintained, providing enhanced accountability, for daily/weekly checks, routine audits, and follow-up investigations. The key attributes of the EMSS include improved accountability, reduced risk of human error, improved accuracy and timeliness of inventory data, and reduced costs as a result of man-hour reductions. C1 Pacific NW Natl Lab, Richland, WA 99352 USA. RP Silvers, KL (reprint author), Pacific NW Natl Lab, Richland, WA 99352 USA. NR 0 TC 0 Z9 0 U1 0 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-9120-9 PY 2005 BP 35 EP 41 PG 7 WC Computer Science, Artificial Intelligence; Computer Science, Interdisciplinary Applications; Engineering, Multidisciplinary SC Computer Science; Engineering GA BDG35 UT WOS:000233365000007 ER PT B AU Caldwell, M Higgins, M AF Caldwell, M Higgins, M GP IEEE TI Electromagnetic test facilities at Sandia National Laboratories SO 2005 IEEE International Workshop on Measurement Systems for Homeland Security, Contraband Detection & Personal Safety LA English DT Proceedings Paper CT IEEE International Workshop on Measurement Systems for Homeland Security, Contraband Detection and Personal Safety CY MAR 29-30, 2005 CL Orlando, FL SP IEEE DE testing; facilities; lightning; mode-stirred chambers; anechoic chambers; TEM cells AB Described below are major electromagnetic test facilities at Sandia National Laboratories; each has undergone recent upgrades. This paper will discuss each facility, their uses, and upgrades pertaining to the facilities performance and diagnostic capabilities. The facilities discussed here are the Sandia Lightning Simulator, the Electromagnetic Environments Simulator, the Mode-Stirred Chamber, and Anechoic Chamber. Sandia's expertise in electromagnetics also extends to theoretical analysis and modeling, which can be done in conjunction with tests or experiments. C1 Sandia Natl Labs, Appl Accelerator & Electromagnet Technol Dept, Albuquerque, NM 87185 USA. RP Caldwell, M (reprint author), Sandia Natl Labs, Appl Accelerator & Electromagnet Technol Dept, POB 5800,MS 1152, Albuquerque, NM 87185 USA. NR 3 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-9120-9 PY 2005 BP 57 EP 62 PG 6 WC Computer Science, Artificial Intelligence; Computer Science, Interdisciplinary Applications; Engineering, Multidisciplinary SC Computer Science; Engineering GA BDG35 UT WOS:000233365000010 ER PT S AU Klimov, VI AF Klimov, VI GP IEEE TI Controlled generation of multiexciton states of various multiplicities by single photons in semiconductor nanocrystals SO 2005 IEEE LEOS Annual Meeting Conference Proceedings (LEOS) SE IEEE Lasers and Electro-Optics Society (LEOS) Annual Meeting LA English DT Proceedings Paper CT 18th Annual Meeting of the IEEE-Lasers-and-Electro-Optical-Society CY OCT 22-28, 2005 CL Sydney, AUSTRALIA SP IEEE Lasers & Elect Opt Soc ID SOLAR-CELLS; QUANTUM DOTS; PBSE C1 Los Alamos Natl Lab, Div Chem, Los Alamos, NM 87544 USA. RP Klimov, VI (reprint author), Los Alamos Natl Lab, Div Chem, POB 1663, Los Alamos, NM 87544 USA. NR 7 TC 0 Z9 0 U1 0 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1092-8081 BN 0-7803-9217-5 J9 IEEE LEOS ANN MTG PY 2005 BP 456 EP 457 PG 2 WC Engineering, Electrical & Electronic; Optics SC Engineering; Optics GA BDR62 UT WOS:000235109700231 ER PT S AU Prasankumar, RP Averitt, RD Taylor, AJ Weisse-Bernstein, N Rotella, P von Winckel, G Stintz, A Krishna, S AF Prasankumar, RP Averitt, RD Taylor, AJ Weisse-Bernstein, N Rotella, P von Winckel, G Stintz, A Krishna, S GP IEEE TI Ultrafast relaxation processes in nanostructured materials SO 2005 IEEE LEOS Annual Meeting Conference Proceedings (LEOS) SE IEEE Lasers and Electro-Optics Society (LEOS) Annual Meeting LA English DT Proceedings Paper CT 18th Annual Meeting of the IEEE-Lasers-and-Electro-Optical-Society CY OCT 22-28, 2005 CL Sydney, AUSTRALIA SP IEEE Lasers & Elect Opt Soc ID A-WELL DETECTOR AB Time-resolved dynamics of an InAs/InGaAs quantum-dots-in-a-well detector are measured at 3.9, 7.5, and 10 pm. This technique enables us to track carrier relaxation from three to two to zero dimensions for the first time. C1 Los Alamos Natl Lab, Mat Sci & Technol Div, Los Alamos, NM 87545 USA. RP Prasankumar, RP (reprint author), Los Alamos Natl Lab, Mat Sci & Technol Div, Los Alamos, NM 87545 USA. NR 5 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1092-8081 BN 0-7803-9217-5 J9 IEEE LEOS ANN MTG PY 2005 BP 905 EP 906 PG 2 WC Engineering, Electrical & Electronic; Optics SC Engineering; Optics GA BDR62 UT WOS:000235109700459 ER PT S AU Hussein, YA El-Ghazaly, SM Goodnick, SM AF Hussein, YA El-Ghazaly, SM Goodnick, SM GP IEEE TI Efficient modeling of PIN diode switches employing time-domain electromagnetic-physics-based simulators SO 2005 IEEE MTT-S International Microwave Symposium, Vols 1-4 SE IEEE MTT-S INTERNATIONAL MICROWAVE SYMPOSIUM DIGEST LA English DT Proceedings Paper CT IEEE MTT-S International Microwave Symposium CY JUN 11-17, 2005 CL Long Beach, CA SP IEEE Microwave Theory & Technol Soc DE device transport physics; global modeling; Maxwell's equations; PIN diode switches AB This paper presents an efficient full-wave time-domain simulator for accurate modeling of PIN diode switches. An equivalent circuit of the PIN diode is extracted under different bias conditions using a drift-diffusion physical model. Net recombination is modeled using a Shockley-Read-Hall process, while generation is assumed to be dominated by impact ionization. The device physics is coupled to Maxwell's equations using extended-FDTD formulism. A complete set of results is presented for the on and off states of the PIN switch. The results are validated through comparison with independent measurements, where good agreement is observed. Using this modeling approach, it is demonstrated that one can efficiently optimize PIN switches for better performance. C1 Stanford Univ, Stanford Linear Accelerator Ctr, Menlo Pk, CA 94304 USA. RP Hussein, YA (reprint author), Stanford Univ, Stanford Linear Accelerator Ctr, Menlo Pk, CA 94304 USA. NR 10 TC 1 Z9 1 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 0149-645X BN 0-7803-8845-3 J9 IEEE MTT-S PY 2005 BP 325 EP 328 DI 10.1109/MWSYM.2005.1516592 PG 4 WC Engineering, Electrical & Electronic; Telecommunications SC Engineering; Telecommunications GA BDO34 UT WOS:000234561200075 ER PT B AU Yoo, TS Garcia, HE AF Yoo, TS Garcia, HE GP IEEE TI New results on discrete-event counting under reliable and unreliable observation information SO 2005 IEEE Networking, Sensing and Control Proceedings LA English DT Proceedings Paper CT IEEE International Conference on Networking, Sensing and Control CY MAR 19-22, 2005 CL Tucson, AZ SP IEEE Syst, Man & Cybernet Soc, Univ Arizona, PARCS Res Ctr DE networked sensor design; integration; and fusion; fault detection; information systems; discrete-event systems; unreliable sensor accommodation ID SYSTEMS; DIAGNOSABILITY; DIAGNOSIS AB We present an approach for addressing the issues of detecting repeated fault events in the framework of model-based monitoring of discrete-event systems (DES) under reliable and unreliable observation information. The analysis task is to determine whether a certain observation configuration is capable of reporting the occurrence of fault events while satisfying the performance requirements. If the reliability of observation information is assured, the assessment is accomplished by evaluating diagnosability notions of interest. To evaluate the notions of diagnosability regarding repeated fault counting, polynomial-time verification algorithms are developed. In order to deal with unreliable observation information, the concept of detection confidence is introduced, which measures the quality of fault counting. An algorithm computing detection confidence is conjectured. For on-line fault counting, we develop a new on-line fault counting algorithm assuming observation reliability. The developed algorithm has lower time and space complexities than air online diagnosis algorithm reported in literature for counting the occurrence of repeated faults. This on-line algorithm is naturally extended to handle the unreliable observation information. C1 Idaho Natl Lab, Idaho Falls, ID USA. RP Yoo, TS (reprint author), Idaho Natl Lab, Idaho Falls, ID USA. NR 15 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-8812-7 PY 2005 BP 688 EP 693 PG 6 WC Automation & Control Systems; Computer Science, Artificial Intelligence; Computer Science, Cybernetics; Computer Science, Information Systems SC Automation & Control Systems; Computer Science GA BCP51 UT WOS:000230555300121 ER PT S AU Burks, M Chivers, D Cork, C Cunningham, M Fabris, L Gunter, D Hull, E Lange, D Manini, H Mihailescu, L Nelson, K Niedermayr, T Valentine, J Vetter, K Wright, D AF Burks, Morgan Chivers, Dan Cork, Chris Cunningham, Mark Fabris, Lorenzo Gunter, Donald Hull, Ethan Lange, David Manini, Hugh Mihailescu, Lucian Nelson, Karl Niedermayr, Thomas Valentine, John Vetter, Kai Wright, Doug BE Yu, B TI Imaging performance of the Si/Ge hybrid Compton imager SO 2005 IEEE Nuclear Science Symposium Conference Record, Vols 1-5 SE IEEE NUCLEAR SCIENCE SYMPOSIUM - CONFERENCE RECORD LA English DT Proceedings Paper CT Nuclear Science Symposium/Medical Imaging Conference CY OCT 23-29, 2005 CL Fajardo, PR SP IEEE Nucl & Plasma Sci Soc, Brookhaven Natl Lab, CEA Saclay, DOE, CERN, Lawrence Berkeley Natl Lab, Lawrence Livermore Natl Lab, Stanford Linear Accelerator Ctr, Univ Calif Davis, Univ Washington AB The point spread function (PSF) of a fully instrumented silicon/germanium Compton telescope has been measured as a function of energy and angle. Overall, the resolution was 3 degrees to 4 degrees FWHM over most of the energy range and field of view. The various contributions to the resolution have been quantified. These contributions include the energy and position uncertainty of the detector; source energy; Doppler broadening; and the 1/r broadening characteristic of Compton back-projection. Furthermore, a distortion of the PSF is observed for sources imaged off-axis from the detector. These contributions are discussed and compared to theory and simulations. C1 Lawrence Livermore Natl Lab, Livermore, CA USA. RP Burks, M (reprint author), Lawrence Livermore Natl Lab, Livermore, CA USA. RI Fabris, Lorenzo/E-4653-2013 OI Fabris, Lorenzo/0000-0001-5605-5615 NR 2 TC 0 Z9 0 U1 0 U2 2 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1082-3654 BN 0-7803-9221-3 J9 IEEE NUCL SCI CONF R PY 2005 BP 6 EP 10 PG 5 WC Instruments & Instrumentation; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Instruments & Instrumentation; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA BFH22 UT WOS:000241851900002 ER PT S AU Hengartner, N Borozdin, K Fraser, A Klimemko, A Pfiedhorsky, W Schultz, L AF Hengartner, Nicolas Borozdin, Konstantin Fraser, Andrew Klimemko, Alexei Pfiedhorsky, William Schultz, Larry BE Yu, B TI Information extraction for muon radiography SO 2005 IEEE Nuclear Science Symposium Conference Record, Vols 1-5 SE IEEE NUCLEAR SCIENCE SYMPOSIUM - CONFERENCE RECORD LA English DT Proceedings Paper CT Nuclear Science Symposium/Medical Imaging Conference CY OCT 23-29, 2005 CL Fajardo, PR SP IEEE Nucl & Plasma Sci Soc, Brookhaven Natl Lab, CEA Saclay, DOE, CERN, Lawrence Berkeley Natl Lab, Lawrence Livermore Natl Lab, Stanford Linear Accelerator Ctr, Univ Calif Davis, Univ Washington AB The paths of muons traveling through matter are affected by Coulomb multiple scattering. The magnitude of that interaction depends on the radiation length of the traversed medium, with high-Z matter scattering more than low-Z matter. The net effect on the path of a muon through an object is both a change in the direction and an orthogonal displacement orthogonal. Both these quantities can be measured experimentally for individual muons, opening the possibility of tomographic reconstruction of the radiation lengths of unknown complex objects. We present a framework to characterize the ability to reconstruct the scattering density from muon scattering data for detecting and locating areas of high Z material. Our analysis shows the importance of having detectors with large aperture, and the importance of using both the change in angle and displacement. C1 Los Alamos Natl Lab, Stat Sci Grp, Los Alamos, NM 87545 USA. RP Hengartner, N (reprint author), Los Alamos Natl Lab, Stat Sci Grp, Los Alamos, NM 87545 USA. OI Priedhorsky, William/0000-0003-0295-9138 NR 5 TC 0 Z9 0 U1 1 U2 3 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1082-3654 BN 0-7803-9221-3 J9 IEEE NUCL SCI CONF R PY 2005 BP 11 EP 15 PG 5 WC Instruments & Instrumentation; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Instruments & Instrumentation; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA BFH22 UT WOS:000241851900003 ER PT S AU Vanier, PE Forman, L AF Vanier, Peter E. Forman, Leon BE Yu, B TI Demonstration of a directional fast neutron detector SO 2005 IEEE Nuclear Science Symposium Conference Record, Vols 1-5 SE IEEE NUCLEAR SCIENCE SYMPOSIUM - CONFERENCE RECORD LA English DT Proceedings Paper CT Nuclear Science Symposium/Medical Imaging Conference CY OCT 23-29, 2005 CL Fajardo, PR SP IEEE Nucl & Plasma Sci Soc, Brookhaven Natl Lab, CEA Saclay, DOE, CERN, Lawrence Berkeley Natl Lab, Lawrence Livermore Natl Lab, Stanford Linear Accelerator Ctr, Univ Calif Davis, Univ Washington AB A detector array consisting of 8 photomultiplier tubes equipped with liquid organic scintillators and arranged in two planes has been demonstrated to be capable of detecting both neutrons and gamma rays and distinguishing them by time-of-flight. Moreover, the neutron double-scatter events can be analyzed to determine both the energy spectrum and the probable direction to the source. This information can help to improve the capability to distinguish a localized man-made isotopic source of neutrons from natural background events generated ubiquitously by cosmic rays. The system was constructed using mostly commercial off-the-shelf components, and the, analysis is performed with some customized software algorithms. C1 Brookhaven Natl Lab, Nonproliferat & Natl Secur Dept, Upton, NY 11973 USA. RP Vanier, PE (reprint author), Brookhaven Natl Lab, Nonproliferat & Natl Secur Dept, Upton, NY 11973 USA. NR 4 TC 3 Z9 3 U1 0 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1082-3654 BN 0-7803-9221-3 J9 IEEE NUCL SCI CONF R PY 2005 BP 116 EP 119 PG 4 WC Instruments & Instrumentation; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Instruments & Instrumentation; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA BFH22 UT WOS:000241851900025 ER PT S AU Armstrong, S Baines, JTM Casado, P Clark, A Conde-Muino, P Damazio, D De Santo, A Gomez, MD Emeliyanov, D Gaumer, O George, S Goncalo, R Khomich, A Kilvington, G Konstantinidis, N Kootz, A Lowe, A McMahon, T Mello, AG Osuna, C Padilla, C Parodi, F Reale, VP Pretzl, K Santamarina, C Schiavi, C Sivoklokov, S Stefanidis, E Sutton, M Thomas, E Teixeira-Dias, P Watson, A Wielers, M Woehring, E Wu, X AF Armstrong, S. Baines, J. T. M. Casado, P. Clark, A. Conde-Muino, P. Damazio, D. De Santo, A. Gomez, M. Diaz Emeliyanov, D. Gaumer, O. George, S. Goncalo, R. Khomich, A. Kilvington, G. Konstantinidis, N. Kootz, A. Lowe, A. McMahon, T. Mello, A. G. Osuna, C. Padilla, C. Parodi, F. Reale, V. Perez Pretzl, K. Santamarina, C. Schiavi, C. Sivoklokov, S. Stefanidis, E. Sutton, M. Thomas, E. Teixeira-Dias, P. Watson, A. Wielers, M. Woehring, E. Wu, X. CA ATLAS High Level Trigger Grp BE Yu, B TI Overview of the high-level trigger electron and photon selection for the ATLAS experiment at the LHC SO 2005 IEEE Nuclear Science Symposium Conference Record, Vols 1-5 SE IEEE NUCLEAR SCIENCE SYMPOSIUM - CONFERENCE RECORD LA English DT Proceedings Paper CT Nuclear Science Symposium/Medical Imaging Conference CY OCT 23-29, 2005 CL Fajardo, PR SP IEEE Nucl & Plasma Sci Soc, Brookhaven Natl Lab, CEA Saclay, DOE, CERN, Lawrence Berkeley Natl Lab, Lawrence Livermore Natl Lab, Stanford Linear Accelerator Ctr, Univ Calif Davis, Univ Washington DE ATLAS; LHC; trigger; electron; photon AB The ATLAS experiment is one of two general purpose experiments to start running at the Large Hadron Collider in 2007. The short bunch crossing period of 25 ns and the large background of soft-scattering events overlapped in each bunch crossing pose serious challenges that the ATLAS trigger must overcome in order to efficiently select interesting events. The ATLAS trigger consists of a hardware-based First-Level Trigger and of a software-based High-Level Trigger, which can be further divided into the Second-Level Trigger and the Event Filter. This paper presents the current state of development of methods to be used in the High-Level Trigger to select events containing electrons or photons with high transverse momentum. The performance of these methods is presented, resulting from both simulation studies, timing measurements, and test beam studies. C1 Brookhaven Natl Lab, Upton, NY 11973 USA. RP Armstrong, S (reprint author), Brookhaven Natl Lab, Upton, NY 11973 USA. RI Conde Muino, Patricia/F-7696-2011; Santamarina Rios, Cibran/K-4686-2014; OI Conde Muino, Patricia/0000-0002-9187-7478; Santamarina Rios, Cibran/0000-0002-9810-1816; Goncalo, Jose/0000-0002-3826-3442 NR 18 TC 0 Z9 0 U1 0 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1082-3654 BN 0-7803-9221-3 J9 IEEE NUCL SCI CONF R PY 2005 BP 167 EP 172 PG 6 WC Instruments & Instrumentation; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Instruments & Instrumentation; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA BFH22 UT WOS:000241851900036 ER PT S AU Cancelo, GI AF Cancelo, Gustavo I. BE Yu, B TI Track clustering and vertexing algorithm for L1 trigger SO 2005 IEEE Nuclear Science Symposium Conference Record, Vols 1-5 SE IEEE NUCLEAR SCIENCE SYMPOSIUM - CONFERENCE RECORD LA English DT Proceedings Paper CT Nuclear Science Symposium/Medical Imaging Conference CY OCT 23-29, 2005 CL Fajardo, PR SP IEEE Nucl & Plasma Sci Soc, Brookhaven Natl Lab, CEA Saclay, DOE, CERN, Lawrence Berkeley Natl Lab, Lawrence Livermore Natl Lab, Stanford Linear Accelerator Ctr, Univ Calif Davis, Univ Washington AB One of the keystones of the canceled BTeV experiment (proposed at Fermilab's Tevatron) was its sophisticated three-level trigger[1]. The trigger was designed to reject 99.9% of light-quark background events and retain a large number of B decays. The BTeV Pixel Detector provided a 3-dimensional, high resolution tracking system to detect B signatures. The Level 1 pixel detector trigger was proposed as a two stage process, a track-segment finder and a vertex finder which analyzed every accelerator crossing. In simulations the track-segment finder stage outputs an average of 200 track-segments per accelerator crossing (2.5MHz). The vertexing stage rinds vertices and associates track-segments with the vertices found. This paper proposes a novel adaptive pattern recognition model to find the number and the estimated location of vertices, and to cluster track-segments around those vertices. The track clustering and vertex finding is done in parallel. The pattern recognition model also generates the estimate of other important parameters such as the covariance matrix of the cluster vertices and the minimum distances from the tracks to the vertices needed to compute detached tracks. C1 Fermilab Natl Accelerator Lab, Batavia, IL 60510 USA. RP Cancelo, GI (reprint author), Fermilab Natl Accelerator Lab, Batavia, IL 60510 USA. NR 4 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1082-3654 BN 0-7803-9221-3 J9 IEEE NUCL SCI CONF R PY 2005 BP 264 EP 268 PG 5 WC Instruments & Instrumentation; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Instruments & Instrumentation; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA BFH22 UT WOS:000241851900056 ER PT S AU Milbrath, BD Choate, BJ Fast, JE Kouzes, RT Schweppe, JE AF Milbrath, Brian D. Choate, Bethany J. Fast, James E. Kouzes, Richard T. Schweppe, John E. BE Yu, B TI Comparison of LaBr3 : Ce and NaI(Tl) scintillators for radio-isotope identification devices SO 2005 IEEE Nuclear Science Symposium Conference Record, Vols 1-5 SE IEEE NUCLEAR SCIENCE SYMPOSIUM - CONFERENCE RECORD LA English DT Proceedings Paper CT Nuclear Science Symposium/Medical Imaging Conference CY OCT 23-29, 2005 CL Fajardo, PR SP IEEE Nucl & Plasma Sci Soc, Brookhaven Natl Lab, CEA Saclay, DOE, CERN, Lawrence Berkeley Natl Lab, Lawrence Livermore Natl Lab, Stanford Linear Accelerator Ctr, Univ Calif Davis, Univ Washington ID GAMMA-RAY SPECTROSCOPY; LACL3-CE AB LaBr3:Ce scintillators offer significantly better resolution (< 3% at 662 keV) relative to Nal(TI) and have recently become commercially available in sizes large enough for the handheld, Radio-Isotope Identification Device (RIID) market. Drawbacks to lanthanum halide detectors, however, include internal radioactivity contributing to spectral counts, and a low-energy response which can cause detector resolution to be worse than that of Nal(TI) below 100 keV. To study the potential of this new material for RIIDs we performed a series of measurements comparing a 1.5" x 1.5" LaBr3:Ce detector with an Exploranium GR-135 RIID, which contains a 1.5" x 2.2" NaI(TI) detector. Measurements were taken for short timeframes, as typifies MID usage. Measurements included examples of naturally occurring radioactive material (NORM), typically found in cargo, and special nuclear materials. Some measurements were non-contact, involving short distances or cargo shielding scenarios. To facilitate direct comparison, spectra from the different detectors were analyzed with the same isotope-identification software (ORTEC ScintiVision). C1 PNNL, Richland, WA 99352 USA. RP Milbrath, BD (reprint author), PNNL, Richland, WA 99352 USA. NR 21 TC 1 Z9 1 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1082-3654 BN 0-7803-9221-3 J9 IEEE NUCL SCI CONF R PY 2005 BP 283 EP 287 PG 5 WC Instruments & Instrumentation; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Instruments & Instrumentation; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA BFH22 UT WOS:000241851900060 ER PT S AU Seitz, SL Blackadar, JM Almecci, SK Nelson, MA Gardner, GH Rawool-Sullivan, M Rees, BG Bounds, JA Casson, WH Garner, SE Sullivan, CJ AF Seitz, Sharon L. Blackadar, John M. Almecci, Sarmadi K. Nelson, Mark A. Gardner, Gary H. Rawool-Sullivan, Mohini Rees, Brian G. Bounds, John A. Casson, William H. Garner, Scott E. Sullivan, Clair J. BE Yu, B TI Radiation detection evaluation: RadAssessor characterizes integrated findings SO 2005 IEEE Nuclear Science Symposium Conference Record, Vols 1-5 SE IEEE NUCLEAR SCIENCE SYMPOSIUM - CONFERENCE RECORD LA English DT Proceedings Paper CT Nuclear Science Symposium/Medical Imaging Conference CY OCT 23-29, 2005 CL Fajardo, PR SP IEEE Nucl & Plasma Sci Soc, Brookhaven Natl Lab, CEA Saclay, DOE, CERN, Lawrence Berkeley Natl Lab, Lawrence Livermore Natl Lab, Stanford Linear Accelerator Ctr, Univ Calif Davis, Univ Washington DE detectors; gamma-ray detectors; gamma-ray spectroscopy; isotope identification; isotope; neutron detectors; radiation detectors; radiation monitoring; radioactive material; shielding; spectral analysis AB Radiation handheld instruments perform an integral role in first responder programs to detect illicit radioactive materials and reduce terrorist attacks. A comprehensive understanding of each commercial instrument's performance facilitates rapid and accurate data interpretation and threat assessment. RadAssessor was developed as a radiation detector database to characterize and evaluate commercial handheld instrument findings. Under laboratory conditions, previously reported instrument performance data have been expanded both in terms of the number of instruments tested and sources measured as well as including gamma isotope identification and neutron response findings. Instrument performance data and findings captured within RadAssessor include: radiation detectors, radioactive sources, shielding, experiments, detailed measurements, spectra, and measurement performance categorizations. Measurement performance categorizations are an approach to categorizing gamma identification results based on defining the most abundant isotopes (MAIs) identified during a measurement. There are two category systems that provide both a high-level understanding of instrument performance and a more detailed understanding with additional granularity. RadAssessor features a web-based interface for selecting instruments, isotopes, and shielding combinations. Users are provided with dynamically generated screens based on the most recent data loaded in the RadAssessor database. Graphical and textual results are generated and presented instantaneously for enhanced decision aides. C1 Los Alamos Natl Lab, Adv Nucl Technol Grp, Los Alamos, NM 87545 USA. RP Seitz, SL (reprint author), Los Alamos Natl Lab, Adv Nucl Technol Grp, POB 1663, Los Alamos, NM 87545 USA. OI Sullivan, Clair/0000-0003-4827-5348 NR 12 TC 0 Z9 0 U1 0 U2 2 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1082-3654 BN 0-7803-9221-3 J9 IEEE NUCL SCI CONF R PY 2005 BP 288 EP 291 PG 4 WC Instruments & Instrumentation; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Instruments & Instrumentation; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA BFH22 UT WOS:000241851900061 ER PT S AU McCormick, K Stromswold, D Ely, J Schweppe, J Kouzes, R AF McCormick, Kathleen Stromswold, David Ely, James Schweppe, John Kouzes, Richard BE Yu, B TI Spectroscopic radiation portal monitor prototype SO 2005 IEEE Nuclear Science Symposium Conference Record, Vols 1-5 SE IEEE NUCLEAR SCIENCE SYMPOSIUM - CONFERENCE RECORD LA English DT Proceedings Paper CT Nuclear Science Symposium/Medical Imaging Conference CY OCT 23-29, 2005 CL Fajardo, PR SP IEEE Nucl & Plasma Sci Soc, Brookhaven Natl Lab, CEA Saclay, DOE, CERN, Lawrence Berkeley Natl Lab, Lawrence Livermore Natl Lab, Stanford Linear Accelerator Ctr, Univ Calif Davis, Univ Washington AB A spectroscopic radiation portal monitor (SPM) prototype consisting of four 10.16-cm x 10.16-cm x 40.64-cm sodium iodide (NaI) crystals has been constructed at Pacific Northwest National Laboratory (PNNL). The prototype was put through a variety of tests, including measurements of the absolute detection efficiency of unshielded sources and the detection efficiency and isotopic identification capability of the detector for shielded isotopic sources. The monitor's response to various types of cargo and source configurations was also studied. The results of these tests are presented in this report. C1 Pacific NW Natl Lab, Richland, WA 99352 USA. RP McCormick, K (reprint author), Pacific NW Natl Lab, Richland, WA 99352 USA. NR 2 TC 2 Z9 2 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1082-3654 BN 0-7803-9221-3 J9 IEEE NUCL SCI CONF R PY 2005 BP 292 EP 296 PG 5 WC Instruments & Instrumentation; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Instruments & Instrumentation; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA BFH22 UT WOS:000241851900062 ER PT S AU Schweppe, JE Ely, JH Kouzes, RT McConn, RJ Pagh, RT Robinson, SM Siciliano, ER Borgardt, JD Bender, SE Earnhart, AH AF Schweppe, John E. Ely, James H. Kouzes, Richard T. McConn, Ronald J., Jr. Pagh, Richard T. Robinson, Sean M. Siciliano, Edward R. Borgardt, James D. Bender, Sarah E. Earnhart, Alison H. BE Yu, B TI Validation of computer models for homeland security purposes SO 2005 IEEE Nuclear Science Symposium Conference Record, Vols 1-5 SE IEEE NUCLEAR SCIENCE SYMPOSIUM - CONFERENCE RECORD LA English DT Proceedings Paper CT Nuclear Science Symposium/Medical Imaging Conference CY OCT 23-29, 2005 CL Fajardo, PR SP IEEE Nucl & Plasma Sci Soc, Brookhaven Natl Lab, CEA Saclay, DOE, CERN, Lawrence Berkeley Natl Lab, Lawrence Livermore Natl Lab, Stanford Linear Accelerator Ctr, Univ Calif Davis, Univ Washington AB At Pacific Northwest National Laboratory, we are developing computer models of radiation portal monitors for screening vehicles and cargo. Detailed models of the radiation detection equipment, vehicles, cargo containers, cargos, and radioactive sources have been created. These are used to determine the optimal configuration of detectors and the best alarm algorithms for the detection of items of interest while minimizing nuisance alarms due to the presence of legitimate radioactive material in the commerce stream. Most of the modeling is done with the Monte Carlo code MCNP to describe the transport of gammas and neutrons from extended sources through large, irregularly shaped absorbers to large detectors. A fundamental prerequisite is the validation of the computational models against field measurements. We describe the first step of this validation process, the comparison of the models to measurements with bare static sources. C1 Pacific NW Natl Lab, Richland, WA 99352 USA. RP Schweppe, JE (reprint author), Pacific NW Natl Lab, Richland, WA 99352 USA. NR 1 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1082-3654 BN 0-7803-9221-3 J9 IEEE NUCL SCI CONF R PY 2005 BP 297 EP 301 PG 5 WC Instruments & Instrumentation; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Instruments & Instrumentation; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA BFH22 UT WOS:000241851900063 ER PT S AU Sullivan, CJ Martinez, ME Garner, SE AF Sullivan, C. J. Martinez, M. E. Garner, S. E. BE Yu, B TI Wavelet analysis of sodium iodide spectra SO 2005 IEEE Nuclear Science Symposium Conference Record, Vols 1-5 SE IEEE NUCLEAR SCIENCE SYMPOSIUM - CONFERENCE RECORD LA English DT Proceedings Paper CT Nuclear Science Symposium/Medical Imaging Conference CY OCT 23-29, 2005 CL Fajardo, PR SP IEEE Nucl & Plasma Sci Soc, Brookhaven Natl Lab, CEA Saclay, DOE, CERN, Lawrence Berkeley Natl Lab, Lawrence Livermore Natl Lab, Stanford Linear Accelerator Ctr, Univ Calif Davis, Univ Washington DE gamma-ray spectroscopy; isotope identification; wavelet analysis AB Wavelet analysis is a mathematical technique that was presented in the mid-1980s to solve a variety of problems in signal analysis where the signal is aperiodic, noisy, transient, etc. More recently, wavelets have been applied to other problems such as feature detection and localization, making it a very promising tool for the analysis of gamma-ray spectra. Recent results have also shown that this technique has the potential to benefit over other approaches due to the fact that the signal can simultaneously be analyzed over multiple scales by using wavelet analysis, thus eliminating potential false isotope identifications from artifacts such as the Compton edge and backscatter peaks. This implies that this peak localization algorithm is no longer a function of detector resolution, which changes with energy. We will present our results evaluating the technique of wavelet analysis for low-resolution (NaI) gamma-ray spectra. Emphasis will be placed on wavelet selection and the incorporation of a simple algorithm to the problem of isotope identification. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Sullivan, CJ (reprint author), Los Alamos Natl Lab, POB 1663,MS B228, Los Alamos, NM 87545 USA. OI Sullivan, Clair/0000-0003-4827-5348 NR 10 TC 1 Z9 1 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1082-3654 BN 0-7803-9221-3 J9 IEEE NUCL SCI CONF R PY 2005 BP 302 EP 306 PG 5 WC Instruments & Instrumentation; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Instruments & Instrumentation; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA BFH22 UT WOS:000241851900064 ER PT S AU Cunningham, M Burks, M Chivers, D Cork, C Fabris, L Gunter, D Krings, T Lange, D Hull, E Mihailescu, L Nelson, K Niedermayr, T Protic, D Valentine, J Vetter, K Wright, D AF Cunningham, Mark Burks, Morgan Chivers, Dan Cork, Chris Fabris, Lorenzo Gunter, Donald Krings, Thomas Lange, David Hull, Ethan Mihailescu, Lucian Nelson, Karl Niedermayr, Thomas Protic, Davor Valentine, John Vetter, Kai Wright, Doug BE Yu, B TI First-generation hybrid compact Compton imager SO 2005 IEEE Nuclear Science Symposium Conference Record, Vols 1-5 SE IEEE NUCLEAR SCIENCE SYMPOSIUM - CONFERENCE RECORD LA English DT Proceedings Paper CT Nuclear Science Symposium/Medical Imaging Conference CY OCT 23-29, 2005 CL Fajardo, PR SP IEEE Nucl & Plasma Sci Soc, Brookhaven Natl Lab, CEA Saclay, DOE, CERN, Lawrence Berkeley Natl Lab, Lawrence Livermore Natl Lab, Stanford Linear Accelerator Ctr, Univ Calif Davis, Univ Washington AB At Lawrence Livermore National Laboratory, we are pursuing the development of a gamma-ray imaging system using the Compton effect. We have built our first generation hybrid Compton imaging system, and we have conducted initial calibration and image measurements using this system. In this paper, we present the details of the hybrid Compton imaging system and initial calibration and image measurements. C1 Lawrence Livermore Natl Lab, Livermore, CA USA. RP Cunningham, M (reprint author), Lawrence Livermore Natl Lab, Livermore, CA USA. RI Fabris, Lorenzo/E-4653-2013 OI Fabris, Lorenzo/0000-0001-5605-5615 NR 4 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1082-3654 BN 0-7803-9221-3 J9 IEEE NUCL SCI CONF R PY 2005 BP 312 EP 315 PG 4 WC Instruments & Instrumentation; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Instruments & Instrumentation; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA BFH22 UT WOS:000241851900066 ER PT S AU Kouzes, RT Ely, JH Milbrath, BD Schweppe, JE Siciliano, ER Stromswold, DC AF Kouzes, R. T. Ely, J. H. Milbrath, B. D. Schweppe, J. E. Siciliano, E. R. Stromswold, D. C. BE Yu, B TI Spectroscopic and non-spectroscopic radiation portal applications to border security SO 2005 IEEE Nuclear Science Symposium Conference Record, Vols 1-5 SE IEEE NUCLEAR SCIENCE SYMPOSIUM - CONFERENCE RECORD LA English DT Proceedings Paper CT Nuclear Science Symposium/Medical Imaging Conference CY OCT 23-29, 2005 CL Fajardo, PR SP IEEE Nucl & Plasma Sci Soc, Brookhaven Natl Lab, CEA Saclay, DOE, CERN, Lawrence Berkeley Natl Lab, Lawrence Livermore Natl Lab, Stanford Linear Accelerator Ctr, Univ Calif Davis, Univ Washington AB Countries around the world are deploying radiation portal monitor (RPM) systems and other radiation detection instrumentation to interdict the illegal shipment of radioactive material crossing international borders. These efforts include deployments in the U.S. and in a number of other countries by governments and international organizations. Because of their high efficiency for gamma-ray detection, most deployed RPM systems are based on plastic scintillators. Such systems, however, are largely non-spectroscopic in capability. Fully capable spectroscopic portal monitor (SPM) systems are undergoing engineering development for deployment in the near term. These SPM systems are mostly based upon NaI(TI) gamma ray detector technology and include the ability to identify the detected radioisotopes under many conditions. This identification capability may allow improved operational handling of radiation alarms, particularly those arising from the normal cargo stream of naturally occurring radioactive material (NORM), commercial radioactive sources, and individuals treated with medical radiopharmaceuticals. The goal for improved RPM systems, whether they are spectroscopic or non-spectroscopic, is to increase the sensitivity to threats while reducing the impact that nuisance alarms have on operations. Four hypotheses about radiation screening at borders are conjectured. C1 PNNL, Richland, WA 99352 USA. RP Kouzes, RT (reprint author), PNNL, Richland, WA 99352 USA. NR 8 TC 0 Z9 0 U1 0 U2 3 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1082-3654 BN 0-7803-9221-3 J9 IEEE NUCL SCI CONF R PY 2005 BP 321 EP 325 PG 5 WC Instruments & Instrumentation; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Instruments & Instrumentation; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA BFH22 UT WOS:000241851900068 ER PT S AU Moss, CE Hollas, CL McKinney, GW Myers, WL AF Moss, C. E. Hollas, C. L. McKinney, G. W. Myers, W. L. BE Yu, B TI Comparison of active interrogation techniques SO 2005 IEEE Nuclear Science Symposium Conference Record, Vols 1-5 SE IEEE NUCLEAR SCIENCE SYMPOSIUM - CONFERENCE RECORD LA English DT Proceedings Paper CT Nuclear Science Symposium/Medical Imaging Conference CY OCT 23-29, 2005 CL Fajardo, PR SP IEEE Nucl & Plasma Sci Soc, Brookhaven Natl Lab, CEA Saclay, DOE, CERN, Lawrence Berkeley Natl Lab, Lawrence Livermore Natl Lab, Stanford Linear Accelerator Ctr, Univ Calif Davis, Univ Washington ID HIGHLY ENRICHED URANIUM AB Active interrogation is necessary to detect highly enriched uranium in large cargo containers and trucks. To achieve sufficient penetration, most nuclear techniques first interrogate an object with high-energy photons or neutrons, to produce fission in any highly enriched uranium that may be present, and then detect the gamma rays or neutrons that are produced. Pulsed beams allow the detection of delayed gamma rays or neutrons from fission products between pulses. Many different systems have been proposed recently. This report presents the results for several techniques, both from measurements and from extensive simulations with the MCNPX code. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Moss, CE (reprint author), Los Alamos Natl Lab, Los Alamos, NM 87545 USA. NR 16 TC 1 Z9 1 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1082-3654 BN 0-7803-9221-3 J9 IEEE NUCL SCI CONF R PY 2005 BP 329 EP 332 PG 4 WC Instruments & Instrumentation; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Instruments & Instrumentation; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA BFH22 UT WOS:000241851900070 ER PT S AU Warren, GA Smith, LE Cooper, M Kaye, W AF Warren, Glen A. Smith, L. Eric Cooper, Matt Kaye, William BE Yu, B TI Evaluation framework for search instruments SO 2005 IEEE Nuclear Science Symposium Conference Record, Vols 1-5 SE IEEE NUCLEAR SCIENCE SYMPOSIUM - CONFERENCE RECORD LA English DT Proceedings Paper CT Nuclear Science Symposium/Medical Imaging Conference CY OCT 23-29, 2005 CL Fajardo, PR SP IEEE Nucl & Plasma Sci Soc, Brookhaven Natl Lab, CEA Saclay, DOE, CERN, Lawrence Berkeley Natl Lab, Lawrence Livermore Natl Lab, Stanford Linear Accelerator Ctr, Univ Calif Davis, Univ Washington AB A framework for quantitatively evaluating current and proposed gamma-ray instruments intended for search applications has been developed. The framework is designed to generate a large library of "virtual neighborhoods" that can be used to assess the performance of nearly any gamma-ray sensor type (e.g. handhelds or Compton imagers). Calculating nuisance-source emissions and combining various sources to create a large number of random virtual scenes places a significant computational burden on the development of the framework. To reduce this burden, a number of radiation transport simplifications have been made which maintain the essential physics ingredients for the quantitative assessment of search instruments while significantly reducing computational times. The general approach to creating the evaluation framework and the simplifying transport assumptions employed to make it computationally tractable are discussed, and examples of how such a framework might be utilized by the national and homeland security communities are provided. C1 Pacific NW Natl Lab, Richland, WA 99352 USA. RP Warren, GA (reprint author), Pacific NW Natl Lab, POB 999,MSIN P8-20, Richland, WA 99352 USA. NR 3 TC 2 Z9 2 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1082-3654 BN 0-7803-9221-3 J9 IEEE NUCL SCI CONF R PY 2005 BP 333 EP 337 PG 5 WC Instruments & Instrumentation; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Instruments & Instrumentation; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA BFH22 UT WOS:000241851900071 ER PT S AU Wurtz, R Ziock, KP Fabris, L Graham, R AF Wurtz, Ron Ziock, Klaus-Peter Fabris, Lorenzo Graham, Rion BE Yu, B TI Comparing imaging and non-imaging techniques for reducing background clutter and resolving distant point sources SO 2005 IEEE Nuclear Science Symposium Conference Record, Vols 1-5 SE IEEE NUCLEAR SCIENCE SYMPOSIUM - CONFERENCE RECORD LA English DT Proceedings Paper CT Nuclear Science Symposium/Medical Imaging Conference CY OCT 23-29, 2005 CL Fajardo, PR SP IEEE Nucl & Plasma Sci Soc, Brookhaven Natl Lab, CEA Saclay, DOE, CERN, Lawrence Berkeley Natl Lab, Lawrence Livermore Natl Lab, Stanford Linear Accelerator Ctr, Univ Calif Davis, Univ Washington AB To reach maximum sensitivity, any method used to search for orphan sources must be insensitive to local variations of the background. Using imaging and non-imaging techniques, we analyzed the same data acquired by a large-area, coded-mask-imager search instrument. Data from many passes past a 1 mCi source at 65 m from the instrument were used to construct a model of the instrument response. We then used the model to "hide" the source in data taken in a light urban environment. We compared the success of detecting the hidden sources using coded-mask imaging methods, pseudo-imaging based on a zero-area matched filter, and non-imaging using simple thresholding. The results clearly indicate the superiority of imaging with the coded-mask techniques returning the best results. C1 Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Wurtz, R (reprint author), Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RI Fabris, Lorenzo/E-4653-2013 OI Fabris, Lorenzo/0000-0001-5605-5615 NR 5 TC 1 Z9 1 U1 0 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1082-3654 BN 0-7803-9221-3 J9 IEEE NUCL SCI CONF R PY 2005 BP 338 EP 342 PG 5 WC Instruments & Instrumentation; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Instruments & Instrumentation; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA BFH22 UT WOS:000241851900072 ER PT S AU Aryaeinejad, R Hartwell, JK Spencer, DF AF Aryaeinejad, Rahmat Hartwell, John K. Spencer, David F. BE Yu, B TI Comparison between digital and analog pulse shape discrimination techniques for neutron and gamma ray separation SO 2005 IEEE Nuclear Science Symposium Conference Record, Vols 1-5 SE IEEE NUCLEAR SCIENCE SYMPOSIUM - CONFERENCE RECORD LA English DT Proceedings Paper CT Nuclear Science Symposium/Medical Imaging Conference CY OCT 23-29, 2005 CL Fajardo, PR SP IEEE Nucl & Plasma Sci Soc, Brookhaven Natl Lab, CEA Saclay, DOE, CERN, Lawrence Berkeley Natl Lab, Lawrence Livermore Natl Lab, Stanford Linear Accelerator Ctr, Univ Calif Davis, Univ Washington DE digital signal processing; gamma ray/neutron pulse shape discrimination ID IDENTIFICATION; PHOTODIODE AB Recent advancements in digital signal processing (DSP) using fast processors and a computer allows one to envision using it in pulse shape discrimination. In this study, we have investigated the feasibility of using a DSP to distinguish between neutrons and gamma rays by the shape of their pulses in a liquid scintillator detector (BC501). For neutron/gamma discrimination, the advantage of using a DSP over the analog method is that in an analog system, two separate charge-sensitive ADCs are required. One ADC is used to integrate the beginning of the pulse rise time while the second ADC is for integrating the tail part. In DSP techniques the incoming pulses coming directly from the detector are immediately digitized and can be decomposed into individual pulses waveforms. This eliminates the need for separate ADCs as one can easily get the integration of two parts of the pulse from the digital waveforms. This work describes the performance of these DSP techniques and compares the results with the analog method. C1 Idaho Natl Engn Lab, Idaho Falls, ID 83415 USA. RP Aryaeinejad, R (reprint author), Idaho Natl Engn Lab, Idaho Falls, ID 83415 USA. NR 12 TC 2 Z9 2 U1 2 U2 4 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1082-3654 BN 0-7803-9221-3 J9 IEEE NUCL SCI CONF R PY 2005 BP 500 EP 504 PG 5 WC Instruments & Instrumentation; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Instruments & Instrumentation; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA BFH22 UT WOS:000241851900108 ER PT S AU Mengesha, W Mascarenhas, N Peel, J Sunnarborg, D AF Mengesha, W. Mascarenhas, N. Peel, J. Sunnarborg, D. BE Yu, B TI 14-MeV neutron directional fiber detector modeling using GEANT SO 2005 IEEE Nuclear Science Symposium Conference Record, Vols 1-5 SE IEEE NUCLEAR SCIENCE SYMPOSIUM - CONFERENCE RECORD LA English DT Proceedings Paper CT Nuclear Science Symposium/Medical Imaging Conference CY OCT 23-29, 2005 CL Fajardo, PR SP IEEE Nucl & Plasma Sci Soc, Brookhaven Natl Lab, CEA Saclay, DOE, CERN, Lawrence Berkeley Natl Lab, Lawrence Livermore Natl Lab, Stanford Linear Accelerator Ctr, Univ Calif Davis, Univ Washington DE neutron; directional fiber detector; scintillating fiber; GEANT AB GEANT4 Monte Carlo simulation tool was used to model a prototype 14 MeV neutron fiber detector under development at the Sandia National Laboratories (SNL). Detail geometric design features of the prototype fiber detector were implemented in the modeling to assess directionality and performance of the detector. BCF-12, plastic fiber material, produced by Saint-Gobain, was used in the prototype development. The fiber consists of a core scintillating material of polystyrene with 0.48 mm x 0.48 mm dimension and an acrylic outer cladding of 0.02 mm thickness. A total of 64 square fibers, each with a cross-sectional area of 0.25 mm(2) and length of 100 mm positioned parallel with a fiber pitch of 2.3 mm, were used in the tracking of 14-MeV neutron induced recoil proton (n-p) events. Neutron induced recoil proton events, resulting energy deposition in two collinear fibers, were considered in reconstructing a two dimensional (21)) direction of incident neutrons. Energy resolution of the fiber detector was also considered to account uncertainty in direction reconstruction. Reconstructed direction has a limiting angular resolution of 3 degrees due to fiber dimension. Energy resolution of the fiber, which was estimated to be 10% at 14 MeV proton energy, resulted in further broadening of the reconstructed direction and the simulated angular resolution was 20 degrees. These values were determined when incident neutron beam makes an angle of 45 degree relative to the front surface of the detector. Comparable values were obtained at other angles of incidence. Results from the present simulation have demonstrated promising directionality of the scintillating fiber detector under development. C1 Sandia Natl Labs, Livermore, CA 94550 USA. RP Mengesha, W (reprint author), Sandia Natl Labs, 7011 East Ave, Livermore, CA 94550 USA. NR 11 TC 1 Z9 1 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1082-3654 BN 0-7803-9221-3 J9 IEEE NUCL SCI CONF R PY 2005 BP 535 EP 539 PG 5 WC Instruments & Instrumentation; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Instruments & Instrumentation; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA BFH22 UT WOS:000241851900115 ER PT S AU Gardner, GH Murray, WS Trowbridge, LD Simmons, DW AF Gardner, G. H. Murray, W. S. Trowbridge, L. D. Simmons, D. W. BE Yu, B TI A miniature, self-contained, CdZnTe gamma spectrometer for use in unattended nuclear material monitoring SO 2005 IEEE Nuclear Science Symposium Conference Record, Vols 1-5 SE IEEE NUCLEAR SCIENCE SYMPOSIUM - CONFERENCE RECORD LA English DT Proceedings Paper CT Nuclear Science Symposium/Medical Imaging Conference CY OCT 23-29, 2005 CL Fajardo, PR SP IEEE Nucl & Plasma Sci Soc, Brookhaven Natl Lab, CEA Saclay, DOE, CERN, Lawrence Berkeley Natl Lab, Lawrence Livermore Natl Lab, Stanford Linear Accelerator Ctr, Univ Calif Davis, Univ Washington ID PHASE; UF6 AB A small, self-contained, CdZnTe-based data acquisition system has been developed at Los Alamos National Laboratory that can be used for the unattended monitoring of gaseous uranium hexafluoride (UF6) processes. The miniature device uses a twin-detector design with a unique collimation and shielding system to assist with gaseous UF6 wall-deposit characterization. The detectors are fully supported with bias voltages, read-out electronics, a multichannel analyzer, and a microprocessor, all within a compact package that can be run on DC power. First-generation, automated data collection and analysis software provides change-of-state detection capability and the unattended measurement of UF6 gas enrichment. Significant changes in the detector count rate trigger new gas measurements. All information and analysis results are stored onboard and may be accessed later. The software has been developed and tested using actual UF6 material in a test loop at Oak Ridge National Laboratory. This paper discusses the system hardware and software specifications and capabilities, and reports on the UF6 gas measurement results. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Gardner, GH (reprint author), Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. NR 6 TC 0 Z9 0 U1 1 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1082-3654 BN 0-7803-9221-3 J9 IEEE NUCL SCI CONF R PY 2005 BP 545 EP 549 PG 5 WC Instruments & Instrumentation; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Instruments & Instrumentation; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA BFH22 UT WOS:000241851900117 ER PT S AU Scates, W Hartwell, JK Aryaeinejad, R McIlwain, ME AF Scates, W. Hartwell, J. K. Aryaeinejad, R. McIlwain, M. E. BE Yu, B TI Optimization studies of a Compton Suppression Spectrometer using experimentally validated Monte Carlo simulations SO 2005 IEEE Nuclear Science Symposium Conference Record, Vols 1-5 SE IEEE NUCLEAR SCIENCE SYMPOSIUM - CONFERENCE RECORD LA English DT Proceedings Paper CT Nuclear Science Symposium/Medical Imaging Conference CY OCT 23-29, 2005 CL Fajardo, PR SP IEEE Nucl & Plasma Sci Soc, Brookhaven Natl Lab, CEA Saclay, DOE, CERN, Lawrence Berkeley Natl Lab, Lawrence Livermore Natl Lab, Stanford Linear Accelerator Ctr, Univ Calif Davis, Univ Washington AB Recent developments associated with room temperature semiconductor detectors and inorganic scintillators suggest that these detectors may be viable alternatives for the primary detector in a Compton Suppression Spectrometer (CSS). The room temperature operation of these detectors allows removal of a substantial amount of material from between primary and secondary detector and, if properly designed should afford substantially better suppression factors than can be achieved by germanium-based spectrometers. We have chosen to study the optimum properties of a CSS with a LaX3:Ce scintillator (where X is chloride or bromide) as the primary gamma ray detector. A Monte Carlo photon transport model is used to determine the optimum geometric properties of this spectrometer. To validate the assumptions and basic design of the Monte Carlo simulations, the energy distribution of a Cs-137 point source is measured and simulated for two experimental systems. Comparison of the suppression factors for the measured and simulated data validates the model accuracy. A range of CSS physical parameters are studied to determine optimal detector geometry and to maximize the Compton suppression factor. These physical parameters and their optimum values are discussed. C1 Idaho Natl Lab, Dept Chem Sci, Idaho Falls, ID 83415 USA. RP Scates, W (reprint author), Idaho Natl Lab, Dept Chem Sci, Idaho Falls, ID 83415 USA. NR 9 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1082-3654 BN 0-7803-9221-3 J9 IEEE NUCL SCI CONF R PY 2005 BP 550 EP 554 PG 5 WC Instruments & Instrumentation; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Instruments & Instrumentation; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA BFH22 UT WOS:000241851900118 ER PT S AU Scates, DM Hartwell, JK AF Scates, Dawn M. Hartwell, John K. BE Yu, B TI A comparison of the high count rate performance of several commercially available digital signal processors SO 2005 IEEE Nuclear Science Symposium Conference Record, Vols 1-5 SE IEEE NUCLEAR SCIENCE SYMPOSIUM - CONFERENCE RECORD LA English DT Proceedings Paper CT Nuclear Science Symposium/Medical Imaging Conference CY OCT 23-29, 2005 CL Fajardo, PR SP IEEE Nucl & Plasma Sci Soc, Brookhaven Natl Lab, CEA Saclay, DOE, CERN, Lawrence Berkeley Natl Lab, Lawrence Livermore Natl Lab, Stanford Linear Accelerator Ctr, Univ Calif Davis, Univ Washington AB Three commercial gamma-ray digital signal processors (DSPs), a Canberra InSpector 2000, an ORTEC DigiDART, and an X-Ray Instrumentation Associates (XIA) Polaris system, coupled to a Canberra 2002C resistive-feedback preamplifier-equipped high-purity germanium (HPGe) detector, were performance tested to input rates of 440 kHz. This is a continuation study of work that was performed at the Idaho National Lab. In the first phase of this study the Canberra DSA2000 and the ORTEC DSPECPLUS were coupled to a transistor reset pre-amplifier (TRP) equipped HPGe gamma-ray detector and performance tested to input rates of 603 kHz. All spectrometers were evaluated on their throughput, stability and peak shape performance. The accuracy of their quantitative corrections for dead-time and pile-up were also tested. All of the tested units performed well at input rates that strain most analog spectroscopy systems. C1 Idaho Natl Lab, Idaho Falls, ID 83415 USA. RP Scates, DM (reprint author), Idaho Natl Lab, POB 1625, Idaho Falls, ID 83415 USA. NR 10 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1082-3654 BN 0-7803-9221-3 J9 IEEE NUCL SCI CONF R PY 2005 BP 555 EP 559 PG 5 WC Instruments & Instrumentation; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Instruments & Instrumentation; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA BFH22 UT WOS:000241851900119 ER PT S AU Britton, CL Bryan, WL Wintenberg, AL Clonts, LG Warmack, RJ McKnight, TE Frank, SS Cooper, RG Dudney, NJ Veith, GM AF Britton, Charles L. Bryan, William L. Wintenberg, Alan L. Clonts, Lloyd G. Warmack, Robert J. McKnight, Timothy E. Frank, S. Shane Cooper, Ronald G. Dudney, Nancy J. Veith, Gabriel M. BE Yu, B TI A detector for 2-d neutron imaging for the spallation neutron source SO 2005 IEEE Nuclear Science Symposium Conference Record, Vols 1-5 SE IEEE NUCLEAR SCIENCE SYMPOSIUM - CONFERENCE RECORD LA English DT Proceedings Paper CT Nuclear Science Symposium/Medical Imaging Conference CY OCT 23-29, 2005 CL Fajardo, PR SP IEEE Nucl & Plasma Sci Soc, Brookhaven Natl Lab, CEA Saclay, DOE, CERN, Lawrence Berkeley Natl Lab, Lawrence Livermore Natl Lab, Stanford Linear Accelerator Ctr, Univ Calif Davis, Univ Washington AB We have designed, built, and tested a 2-D pixellated thermal neutron detector. The detector is modeled after the MicroMegas-type structure previously published for collider-type experiments. The detector consists of a 4X4 square array of 1cm(2) pixels each of which is connected to an individual preamplifier-shaper-data acquisition system. The neutron converter is a B-10 film on an aluminum substrate. We describe the construction of the detector and the test results utilizing Cf-252 sources in Lucite to thermalize the neutrons. C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Britton, CL (reprint author), Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RI McKnight, Tim/H-3087-2011; Dudney, Nancy/I-6361-2016 OI McKnight, Tim/0000-0003-4326-9117; Dudney, Nancy/0000-0001-7729-6178 NR 3 TC 0 Z9 0 U1 1 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1082-3654 BN 0-7803-9221-3 J9 IEEE NUCL SCI CONF R PY 2005 BP 616 EP 618 PG 3 WC Instruments & Instrumentation; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Instruments & Instrumentation; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA BFH22 UT WOS:000241851900132 ER PT S AU De Lurgio, PM Farrar, KA Kreps, AS Madden, TJ Naday, I Weizeorick, JT Hammonds, JP Miller, ME Schultz, AJ AF De Lurgio, Patrick M. Farrar, Kelly A. Kreps, Andrew S. Madden, Timothy J. Naday, Istvan Weizeorick, John T. Hammonds, John P. Miller, Martha E. Schultz, Arthur J. BE Yu, B TI 2-D scintillation position-sensitive neutron detector SO 2005 IEEE Nuclear Science Symposium Conference Record, Vols 1-5 SE IEEE NUCLEAR SCIENCE SYMPOSIUM - CONFERENCE RECORD LA English DT Proceedings Paper CT Nuclear Science Symposium/Medical Imaging Conference CY OCT 23-29, 2005 CL Fajardo, PR SP IEEE Nucl & Plasma Sci Soc, Brookhaven Natl Lab, CEA Saclay, DOE, CERN, Lawrence Berkeley Natl Lab, Lawrence Livermore Natl Lab, Stanford Linear Accelerator Ctr, Univ Calif Davis, Univ Washington DE single crystal diffraction; neutron; position-sensitive; scintillation AB A new 2-dimensional scintillation Position-Sensitive Neutron Detector (PSND) with an active area of 155 x 155 mm(2) was developed for use on the Single Crystal Diffractometer at the Intense Pulsed Neutron Source at Argonne National Laboratory. The detector is based on the well-proven Anger camera technique and uses a Li-6 glass scintillator as the neutron converter. This PSND incorporates a 6 x 6 PMT array with 29.6 mm pitch and optimized optics to achieve an average spatial resolution of 1.75 mm full width at half maximum. The detector read-out has separate electronics for each PMT and the neutron position is calculated by a microprocessor during acquisition. A newly developed position extraction algorithm makes use of an analytical calculation to determine the event position. This new method improves the linearity of the calculated position, provides a slight improvement in resolution, and in principle allows for the correct determination of position to the edge of the scintillator. The design of the detector enclosure allows multiple detectors to be tiled with minimal dead space between them. In addition, the design incorporates a means of attaching external shielding plates that minimizes the shielding surface area required. C1 Argonne Natl Lab, Argonne, IL 60439 USA. RP De Lurgio, PM (reprint author), Argonne Natl Lab, 9700 S Cass Ave, Argonne, IL 60439 USA. NR 4 TC 1 Z9 1 U1 1 U2 2 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1082-3654 BN 0-7803-9221-3 J9 IEEE NUCL SCI CONF R PY 2005 BP 648 EP 653 PG 6 WC Instruments & Instrumentation; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Instruments & Instrumentation; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA BFH22 UT WOS:000241851901007 ER PT S AU Watson, SA Appleby, M Klinger, J Balzer, S Lebeda, C Bowman, D Montoya, J Bultman, D Vecere, C Gossein, C AF Watson, S. A. Appleby, M. Klinger, J. Balzer, S. Lebeda, C. Bowman, D. Montoya, J. Bultman, D. Vecere, C. Gossein, C. BE Yu, B TI Design, fabrication and testing of a large anti-scatter grid for Megavolt gamma-ray imaging SO 2005 IEEE Nuclear Science Symposium Conference Record, Vols 1-5 SE IEEE NUCLEAR SCIENCE SYMPOSIUM - CONFERENCE RECORD LA English DT Proceedings Paper CT Nuclear Science Symposium/Medical Imaging Conference CY OCT 23-29, 2005 CL Fajardo, PR SP IEEE Nucl & Plasma Sci Soc, Brookhaven Natl Lab, CEA Saclay, DOE, CERN, Lawrence Berkeley Natl Lab, Lawrence Livermore Natl Lab, Stanford Linear Accelerator Ctr, Univ Calif Davis, Univ Washington DE Bucky grid; gamma ray; scatter; radiography; NDE AB Despite a century-old patent, and wide application at lower energies, the fabrication of thick anti-scatter "Bucky" grids for application at megavolt energies has been an elusive goal. We discuss the design, fabrication and testing of a 45 cm-diameter grid with a focal length of 525cm for use at the 20MeV DARHT flash radiographic facility. The predominant difficulties overcome were: (1) understanding the performance of such grids prior to fabrication, and (2) the precision fabrication itself. To understand the former, we employed a specially modified version of the MCNP Monte Carlo code run on the ASC Blue-Mountain supercomputer at Los Alamos to explore and optimize the parameter space. These calculations were benchmarked at the Los Alamos Microtron facility using a small prototype grid. To have useful scatter rejection at megavolt energies, grid ratios of several hundred-to-one are required. State-of-the-art grids used in medical radiography have grid ratios of ten-to-one. We demonstrate a unique casting technology capable of accurately manufacturing large grids with very high grid ratios. Promising initial test results are also presented. It is our belief that similar grids will prove useful in a wide range of potential applications including: megavolt NDE radiography, Compton scatter radiography, balloon-born gamma-ray astronomy, medical therapy, and in the intended application of flash radiography at Los Alamos' DARHT facility. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Watson, SA (reprint author), Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. NR 15 TC 3 Z9 4 U1 0 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1082-3654 BN 0-7803-9221-3 J9 IEEE NUCL SCI CONF R PY 2005 BP 717 EP 721 PG 5 WC Instruments & Instrumentation; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Instruments & Instrumentation; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA BFH22 UT WOS:000241851901022 ER PT S AU Cardoso, G Turqueti, MA Andresen, J Appel, JA Christian, DC Chramowicz, J Deuerling, G Hoff, JR Kwan, SW Mekkaoui, A Prosser, AG Uplegger, L Yarema, R AF Cardoso, G. Turqueti, M. A. Andresen, J. Appel, J. A. Christian, D. C. Chramowicz, J. Deuerling, G. Hoff, J. R. Kwan, S. W. Mekkaoui, A. Prosser, A. G. Uplegger, L. Yarema, R. BE Yu, B TI An overview of packaging and characterization results of pixel multichip modules at Feermilab SO 2005 IEEE Nuclear Science Symposium Conference Record, Vols 1-5 SE IEEE NUCLEAR SCIENCE SYMPOSIUM - CONFERENCE RECORD LA English DT Proceedings Paper CT Nuclear Science Symposium/Medical Imaging Conference CY OCT 23-29, 2005 CL Fajardo, PR SP IEEE Nucl & Plasma Sci Soc, Brookhaven Natl Lab, CEA Saclay, DOE, CERN, Lawrence Berkeley Natl Lab, Lawrence Livermore Natl Lab, Stanford Linear Accelerator Ctr, Univ Calif Davis, Univ Washington AB At Fermilab, there is an ongoing pixel detector R&D effort for High Energy Physics with the objective of developing high performance vertex detectors suitable for the next generation of HEP experiments. The pixel module presented here is a direct result of work undertaken for the cancelled BTeV experiment. It is a very mature piece of hardware, having many characteristics of high performance, low mass and radiation hardness driven by the requirements of the BTeV experiment. The detector presented in this paper consists of three basic devices; the readout integrated circuit (IC) FPIX2A [2] [5], the pixel sensor (TESLA p-spray) [6] and the high density interconnect (HDI) flex. circuit [1][3] that is capable of supporting eight readout ICs. The characterization of the pixel multichip module prototype as well as the baseline design of the eight-chip pixel module and its capabilities are presented. The PCI test adapter (PTA) card used to characterize the pixel module prototypes is also presented. These prototypes were characterized for threshold and noise dispersion. The bump-bonds of the pixel module were examined using an X-ray inspection system. Furthermore, the connectivity of the bump-bonds was tested using a radioactive source (Sr-90), while the absolute calibration of the modules was achieved using an X-ray source. This paper provides a view of the integration of the three components that together comprise the pixel multichip module. C1 Fermilab Natl Accelerator Lab, Batavia, IL 60510 USA. RP Cardoso, G (reprint author), Fermilab Natl Accelerator Lab, Batavia, IL 60510 USA. NR 6 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1082-3654 BN 0-7803-9221-3 J9 IEEE NUCL SCI CONF R PY 2005 BP 819 EP 822 PG 4 WC Instruments & Instrumentation; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Instruments & Instrumentation; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA BFH22 UT WOS:000241851901045 ER PT S AU Avramidou, R AF Avramidou, Rachel BE Yu, B TI Sagitta studies for the endcap muon chambers of the ATLAS spectrometer SO 2005 IEEE Nuclear Science Symposium Conference Record, Vols 1-5 SE IEEE NUCLEAR SCIENCE SYMPOSIUM - CONFERENCE RECORD LA English DT Proceedings Paper CT Nuclear Science Symposium/Medical Imaging Conference CY OCT 23-29, 2005 CL Fajardo, PR SP IEEE Nucl & Plasma Sci Soc, Brookhaven Natl Lab, CEA Saclay, DOE, CERN, Lawrence Berkeley Natl Lab, Lawrence Livermore Natl Lab, Stanford Linear Accelerator Ctr, Univ Calif Davis, Univ Washington AB The ATLAS detector for the Large Hadron Collider at CERN will study the products of protons collisions at. energies of up to 14 TeV. One of its subdetectors is a high-resolution Muon Spectrometer designed to exploit the physics potentials. A system test of the ATLAS Muon Spectrometer has been performed in the H8 test beam area at the CERN SPS. C1 US DOE, Washington, DC 20585 USA. Natl Tech Univ Athens, GR-10682 Athens, Greece. Univ Michigan, Ann Arbor, MI 48109 USA. RP Avramidou, R (reprint author), US DOE, Washington, DC 20585 USA. NR 1 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1082-3654 BN 0-7803-9221-3 J9 IEEE NUCL SCI CONF R PY 2005 BP 834 EP 837 PG 4 WC Instruments & Instrumentation; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Instruments & Instrumentation; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA BFH22 UT WOS:000241851901049 ER PT S AU Khan, A Schofield, K Wright, D AF Khan, Akram Schofield, Katharine Wright, Dennis BE Yu, B TI Validation of Geant4 electromagnetic and hadronic processes in the BABAR detector SO 2005 IEEE Nuclear Science Symposium Conference Record, Vols 1-5 SE IEEE NUCLEAR SCIENCE SYMPOSIUM - CONFERENCE RECORD LA English DT Proceedings Paper CT Nuclear Science Symposium/Medical Imaging Conference CY OCT 23-29, 2005 CL Fajardo, PR SP IEEE Nucl & Plasma Sci Soc, Brookhaven Natl Lab, CEA Saclay, DOE, CERN, Lawrence Berkeley Natl Lab, Lawrence Livermore Natl Lab, Stanford Linear Accelerator Ctr, Univ Calif Davis, Univ Washington DE Geant4 validation; electromagnetic calorimeter AB BABAR was the first large experiment to use the Geant4 toolkit to build its simulation code. The production version of the simulation has been running since July 2001 and has so far produced 7 x 10(9) fully reconstructed events. Extensive validations of the simulation continue to be performed by comparing the simulated results in various BABAR subdetectors to data. The most stringent test is the examination of electromagnetic shower shapes in the electromagnetic calorimeter (EMC). Agreement of these shower shapes with data represent an important confirmation of both the geometry and material composition of the BABAR detector and of the validity of the Geant4 standard electromagnetic processes invoked by the simulation. As important, but more difficult to test, is the validity of Geant4 hadronic processes. This study led to the choice of the best-performing hadronic model from three available in the Geant4 toolkit. A brief description of the BaBar Detector and a summary of the Geant4 physics processes used to simulate it are presented here. Validation plots comparing actual shower shapes with the simulation, and comparing predicted secondary particle distributions with data are shown. C1 Brunel Univ, Uxbridge UB8 3PH, Middx, England. Univ Liverpool, Liverpool L69 3BX, Merseyside, England. Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. RP Khan, A (reprint author), Brunel Univ, Uxbridge UB8 3PH, Middx, England. NR 3 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1082-3654 BN 0-7803-9221-3 J9 IEEE NUCL SCI CONF R PY 2005 BP 844 EP 846 PG 3 WC Instruments & Instrumentation; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Instruments & Instrumentation; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA BFH22 UT WOS:000241851901051 ER PT S AU Re, V Manghisoni, M Ratti, L Hoff, J Mekkaoui, A Yarema, R AF Re, Valerio Manghisoni, Massimo Ratti, Lodovico Hoff, Jim Mekkaoui, Abderrezak Yarema, Ray BE Yu, B TI FSSR2, a self-triggered low noise readout chip for silicon strip detectors SO 2005 IEEE NUCLEAR SCIENCE SYMPOSIUM CONFERENCE RECORD, VOLS 1-5 SE IEEE Nuclear Science Symposium Conference Record LA English DT Proceedings Paper CT Nuclear Science Symposium/Medical Imaging Conference CY OCT 23-29, 2005 CL Fajardo, PR SP IEEE Nucl & Plasma Sci Soc, Brookhaven Natl Lab, CEA Saclay, DOE, CERN, Lawrence Berkeley Natl Lab, Lawrence Livermore Natl Lab, Stanford Linear Accelerator Ctr, Univ Calif Davis, Univ Washington ID SUBMICRON CMOS TECHNOLOGIES; CIRCUITS; BTEV AB The FSSR2 is the second release of the Fermilab Silicon Strip Readout Chip. The chip has been designed and fabricated in a 0.25 mu m CMOS technology for high radiation tolerance. The first release, simply called the FSSR, was a prototype version with many different analog front-end configurations. The best solution was chosen for the FSSR2 chip to optimize the noise, according to criteria discussed in this paper. The FSSR2 has been designed for the silicon strip detectors of the BTeV experiment. The chip services 128 strips and provides address, time and magnitude information for all hits. Several programmable features are included in FSSR2, such as an internal pulser, a baseline restorer and a signal peaking time selectable among four values in the range between 65 ns and 125 ns. The circuit design and the performances of FSSR2 are discussed in this paper. C1 Fermilab Natl Accelerator Lab, Batavia, IL 60510 USA. RP Re, V (reprint author), Fermilab Natl Accelerator Lab, POB 500, Batavia, IL 60510 USA. EM valerio.re@unibg.it; lodovico.ratti@unipv.it; yarema@fnal.gov RI Ratti, Lodovico/I-8836-2012; OI RATTI, LODOVICO/0000-0003-1906-1076; Re, Valerio/0000-0003-0697-3420; Manghisoni, Massimo/0000-0001-5559-0894 NR 10 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1082-3654 BN 0-7803-9221-3 J9 IEEE NUCL SCI CONF R PY 2005 BP 896 EP 900 PG 5 WC Instruments & Instrumentation; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Instruments & Instrumentation; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA BFH22 UT WOS:000241851901063 ER PT S AU Junnarkar, SS Kandasamy, A Fried, J O'Connor, P Polychronakos, V Gratchev, V Tcherniatine, V Khodinov, A Maramraju, SH Srauss, E AF Junnarkar, Sachin S. Kandasamy, Anand Fried, Jack O'Connor, Paul Polychronakos, V. Gratchev, Vadim Tcherniatine, V. Khodinov, A. Maramraju, Sri Harsha Srauss, Emanuel BE Yu, B TI Advanced front end signal processing electronics for ATLAS cathode strip chamber system SO 2005 IEEE Nuclear Science Symposium Conference Record, Vols 1-5 SE IEEE NUCLEAR SCIENCE SYMPOSIUM - CONFERENCE RECORD LA English DT Proceedings Paper CT Nuclear Science Symposium/Medical Imaging Conference CY OCT 23-29, 2005 CL Fajardo, PR SP IEEE Nucl & Plasma Sci Soc, Brookhaven Natl Lab, CEA Saclay, DOE, CERN, Lawrence Berkeley Natl Lab, Lawrence Livermore Natl Lab, Stanford Linear Accelerator Ctr, Univ Calif Davis, Univ Washington AB The ATLAS muon spectrometer will employ Cathode Strip Chambers (CSC) to measure high momentum muons in the extreme forward regions. Preamplifcation of the charge on the strips is performed in the Amplifier Shaper Module I. Amplifier Shaper Module II performs the analog buffering, digitization of the charge signals from individual cathode strips and multiplexes the data into two fibre optics links at 1 Gbps each. We present the design architecture of the complete front end electronics chain and its performance. We also report on the production and testing status of overall on detector electronics. C1 Brookhaven Natl Lab, Upton, NY 11973 USA. RP Junnarkar, SS (reprint author), Brookhaven Natl Lab, Upton, NY 11973 USA. OI KHODINOV, ALEKSANDR/0000-0003-3551-5808 NR 6 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1082-3654 BN 0-7803-9221-3 J9 IEEE NUCL SCI CONF R PY 2005 BP 909 EP 913 PG 5 WC Instruments & Instrumentation; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Instruments & Instrumentation; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA BFH22 UT WOS:000241851901066 ER PT S AU Junnarkar, SS Purschke, M Pratte, JF Park, SJ O'Connor, P Fontaine, R AF Junnarkar, Sachin S. Purschke, Martin Pratte, Jean-Francois Park, Sang-June O'Connor, Paul Fontaine, Rejean BE Yu, B TI An FPGA-based, 12-channel TDC and digital signal processing module for the RatCAP scanner SO 2005 IEEE Nuclear Science Symposium Conference Record, Vols 1-5 SE IEEE NUCLEAR SCIENCE SYMPOSIUM - CONFERENCE RECORD LA English DT Proceedings Paper CT Nuclear Science Symposium/Medical Imaging Conference CY OCT 23-29, 2005 CL Fajardo, PR SP IEEE Nucl & Plasma Sci Soc, Brookhaven Natl Lab, CEA Saclay, DOE, CERN, Lawrence Berkeley Natl Lab, Lawrence Livermore Natl Lab, Stanford Linear Accelerator Ctr, Univ Calif Davis, Univ Washington ID PET AB Front end digital signal processing and VME based DAQ electronics for the RatCAP (Rat Conscious Animal PET) is discussed. All digital approach to front end signal processing for the mobile animal PET scanner is presented. Altera Cyclone family FPGA based realization of the 12 channel TDC (Time to Digital Converter), address serial decoder and VME based DAQ system development is discussed in detail. Routing delays between LABS combined with propagation delay of logic cells were used to generate different clock phases, to achieve sub clock speed resolution. Altera LogicLock(TM) toolsets were used for replicable and tighter placements of the supporting logic to achieve the required timing performance. TDC realized using controlled placements of the logic elements to specific logic cells within a specific LAB (Logic Array Block) has the maximum DNL of 0.7 us. VME based custom designed board with FIFO memory constituted the DAQ electronics. Test results with full 12 blocks, RatCAP front end electronics are presented. TDC realization and characterization is discussed in details. Timing spectrum obtained for 12 blocks, 384 channels of full RatCAP scanner is also presented. C1 Brookhaven Natl Lab, Upton, NY 11973 USA. RP Junnarkar, SS (reprint author), Brookhaven Natl Lab, Upton, NY 11973 USA. NR 9 TC 3 Z9 3 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1082-3654 BN 0-7803-9221-3 J9 IEEE NUCL SCI CONF R PY 2005 BP 919 EP 923 PG 5 WC Instruments & Instrumentation; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Instruments & Instrumentation; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA BFH22 UT WOS:000241851901068 ER PT S AU Yu, B De Geronimo, G Fried, J Kandasamy, A Makowiecki, DS Smith, GC Radeka, V Hoblit, S Sandorfi, AM Thorn, CE Norum, BE Wang, K Mahon, JC AF Yu, B. De Geronimo, G. Fried, J. Kandasamy, A. Makowiecki, D. S. Smith, G. C. Radeka, V. Hoblit, S. Sandorfi, A. M. Thorn, C. E. Norum, B. E. Wang, K. Mahon, J. C. BE Yu, B TI A GEM based TPC for the LEGS experiment SO 2005 IEEE Nuclear Science Symposium Conference Record, Vols 1-5 SE IEEE NUCLEAR SCIENCE SYMPOSIUM - CONFERENCE RECORD LA English DT Proceedings Paper CT Nuclear Science Symposium/Medical Imaging Conference CY OCT 23-29, 2005 CL Fajardo, PR SP IEEE Nucl & Plasma Sci Soc, Brookhaven Natl Lab, CEA Saclay, DOE, CERN, Lawrence Berkeley Natl Lab, Lawrence Livermore Natl Lab, Stanford Linear Accelerator Ctr, Univ Calif Davis, Univ Washington AB A compact Time Projection Chamber (TPC) has been constructed for the LEGS (Laser Electron Gamma Source) experiment at BNL. The TPC uses double GEMS as the amplification stage. Position encoding is achieved through charge division using zigzag shaped anode pads. The TPC has a 35cm diameter active area and a 50cm long drift depth. It has more than 7000 channels of readout electronics in the form of custom designed ASICs. A novel peak sensing circuit is used to measure simultaneously the amplitude and timing of the signal peak from an anode pad. Test results from a shorter prototype version of the TPC as well as the construction of the final detector are discussed. C1 Brookhaven Natl Lab, Upton, NY 11973 USA. RP Yu, B (reprint author), Brookhaven Natl Lab, Bldg 535B, Upton, NY 11973 USA. NR 3 TC 0 Z9 0 U1 1 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1082-3654 BN 0-7803-9221-3 J9 IEEE NUCL SCI CONF R PY 2005 BP 924 EP 928 PG 5 WC Instruments & Instrumentation; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Instruments & Instrumentation; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA BFH22 UT WOS:000241851901069 ER PT S AU Dodd, J Galea, R Leltchouk, M Ju, Y Willis, W Rehak, P Tcherniatine, V Buzulutskov, A Pavlyuchenko, D AF Dodd, J. Galea, R. Leltchouk, M. Ju, Y. Willis, W. Rehak, P. Tcherniatine, V. Buzulutskov, A. Pavlyuchenko, D. BE Yu, B TI GEM performance in He, Ne, He+H-2 and Ne+H-2 at low temperatures SO 2005 IEEE Nuclear Science Symposium Conference Record, Vols 1-5 SE IEEE NUCLEAR SCIENCE SYMPOSIUM - CONFERENCE RECORD LA English DT Proceedings Paper CT Nuclear Science Symposium/Medical Imaging Conference CY OCT 23-29, 2005 CL Fajardo, PR SP IEEE Nucl & Plasma Sci Soc, Brookhaven Natl Lab, CEA Saclay, DOE, CERN, Lawrence Berkeley Natl Lab, Lawrence Livermore Natl Lab, Stanford Linear Accelerator Ctr, Univ Calif Davis, Univ Washington DE gas electron multiplier; cryogenic noble gases; penning mixtures; electron bubble; helium; neon ID OPERATION AB The performance of Gas Electron Multipliers (GEMS) in gaseous He, Ne, He+H-2 and Ne+H-2 was studied at temperatures in the range of 3-293K. This paper reports on previously published measurements and additional studies on the effects of the purity of the gases in which the GEM performance is evaluated. In He, at temperatures between 77 and 293K, triple-GEM structures operate at rather high gains, exceeding 1000. There is an indication that this high gain is achieved through the Penning effect as a result of impurities in the gas. At lower temperatures the gain-voltage characteristics are significantly modified probably due to the freeze-out of these impurities. Double-GEM and single-GEM structures can operate down to 3K at gains reaching only several tens at a gas density of about 0.5g/l; at higher densities the maximum gain drops further. In Ne, the maximum gain also drops at cryogenic temperatures. The gain drop in Ne at low temperatures can be reestablished in Penning mixtures of Ne+H-2: very high gains, exceeding 10(4), have been obtained in these mixtures at 30-60K, at a density of 9.2g/l which corresponds to saturated Ne vapor density at 27K. The addition of small amounts of H-2 in He also showed a dramatic increase in the GEM gain above 30K but no gain was observed in He+H-2 at 4K and a density of 1.7g/l. These studies are, in part, being pursued in the development of two-phase He and Ne detectors for solar neutrino detection. C1 Brookhaven Natl Lab, Upton, NY 11973 USA. RP Dodd, J (reprint author), Brookhaven Natl Lab, Upton, NY 11973 USA. NR 8 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1082-3654 BN 0-7803-9221-3 J9 IEEE NUCL SCI CONF R PY 2005 BP 932 EP 934 PG 3 WC Instruments & Instrumentation; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Instruments & Instrumentation; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA BFH22 UT WOS:000241851901071 ER PT S AU De Geronimo, G Bolotnikov, AE Carini, G Fried, J O'Connor, P Soldner, SA AF De Geronimo, Gianluigi Bolotnikov, Aleksey E. Carini, Gabriella Fried, Jack O'Connor, Paul Soldner, Stephen A. BE Yu, B TI ASIC for CPG sensors with grid-only depth-of-interaction sensing SO 2005 IEEE Nuclear Science Symposium Conference Record, Vols 1-5 SE IEEE NUCLEAR SCIENCE SYMPOSIUM - CONFERENCE RECORD LA English DT Proceedings Paper CT Nuclear Science Symposium/Medical Imaging Conference CY OCT 23-29, 2005 CL Fajardo, PR SP IEEE Nucl & Plasma Sci Soc, Brookhaven Natl Lab, CEA Saclay, DOE, CERN, Lawrence Berkeley Natl Lab, Lawrence Livermore Natl Lab, Stanford Linear Accelerator Ctr, Univ Calif Davis, Univ Washington ID CDZNTE DETECTORS AB A new version of the front-end Application Specific Integrated Circuit (ASIC) for Coplanar-Grid sensors is presented. Compared to the first version the ASIC is optimized for signal/noise performance, modified in peaking time, and it implements timing signals to measure the depth of interaction using the grids signals only. Experimental results using state-of the-art CPG sensors and different approaches for reducing the error due to electron trapping are reported. A new technique that makes use of the sum and difference of the grids signals is also presented. C1 Brookhaven Natl Lab, Instrumentat Div, Upton, NY 11973 USA. RP De Geronimo, G (reprint author), Brookhaven Natl Lab, Instrumentat Div, Upton, NY 11973 USA. NR 12 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1082-3654 BN 0-7803-9221-3 J9 IEEE NUCL SCI CONF R PY 2005 BP 945 EP 949 PG 5 WC Instruments & Instrumentation; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Instruments & Instrumentation; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA BFH22 UT WOS:000241851901074 ER PT S AU Norman, DR Jones, JL Haskell, KJ Vanier, PE Forman, L AF Norman, Daren R. Jones, James L. Haskell, Kevin J. Vanier, Peter E. Forman, Leon BE Yu, B TI Active nuclear material detection and imaging SO 2005 IEEE Nuclear Science Symposium Conference Record, Vols 1-5 SE IEEE NUCLEAR SCIENCE SYMPOSIUM - CONFERENCE RECORD LA English DT Proceedings Paper CT Nuclear Science Symposium/Medical Imaging Conference CY OCT 23-29, 2005 CL Fajardo, PR SP IEEE Nucl & Plasma Sci Soc, Brookhaven Natl Lab, CEA Saclay, DOE, CERN, Lawrence Berkeley Natl Lab, Lawrence Livermore Natl Lab, Stanford Linear Accelerator Ctr, Univ Calif Davis, Univ Washington AB An experimental evaluation has been conducted to assess the operational performance of a coded-aperture, thermal neutron imaging system and its detection and imaging capability for shielded nuclear material in pulsed photonuclear environments. This evaluation used an imaging system developed by Brookhaven National Laboratory. The active photonuclear environment was produced by an operationally-flexible, Idaho National Laboratory (INL) pulsed electron accelerator. The neutron environments were monitored using INL photonuclear. neutron detectors. Results include experimental images, operational imaging system assessments and recommendations that would enhance nuclear material detection and imaging performance. C1 Idaho Natl Lab, Idaho Falls, ID 83415 USA. RP Norman, DR (reprint author), Idaho Natl Lab, Idaho Falls, ID 83415 USA. NR 3 TC 1 Z9 1 U1 1 U2 3 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1082-3654 BN 0-7803-9221-3 J9 IEEE NUCL SCI CONF R PY 2005 BP 1004 EP 1008 PG 5 WC Instruments & Instrumentation; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Instruments & Instrumentation; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA BFH22 UT WOS:000241851901087 ER PT S AU Robinson, SM Kouzes, R McConn, RJ Pagh, R Schweppe, JE Sicifano, ER AF Robinson, S. M. Kouzes, R. McConn, R. J., Jr. Pagh, R. Schweppe, J. E. Sicifano, E. R. BE Yu, B TI Creation of realistic radiation transport models of radiation portal monitors for homeland security purposes SO 2005 IEEE Nuclear Science Symposium Conference Record, Vols 1-5 SE IEEE NUCLEAR SCIENCE SYMPOSIUM - CONFERENCE RECORD LA English DT Proceedings Paper CT Nuclear Science Symposium/Medical Imaging Conference CY OCT 23-29, 2005 CL Fajardo, PR SP IEEE Nucl & Plasma Sci Soc, Brookhaven Natl Lab, CEA Saclay, DOE, CERN, Lawrence Berkeley Natl Lab, Lawrence Livermore Natl Lab, Stanford Linear Accelerator Ctr, Univ Calif Davis, Univ Washington AB Much of the data used to analyze and calibrate alarm algorithms for radiation portal monitor (RPM) systems has come from actual measurements of vehicles passing through RPMs. Due to the inherent limitations and expense of taking data with controlled radioactive sources, the majority of these data contain no sources except for naturally occurring radioactive material cargo sources in the presence of natural background. Advances in computing capabilities have made it feasible to simulate "in-the-field" detector responses from a wide variety of source/cargo configurations, and to produce data matching that generated in the field. Computational models have been developed by the RPM Project for many detectors, vehicles, cargo configurations, and sources. These models are being used to simulate RPM responses to complicated source/cargo configurations for vehicles with and without sources. The simulated data is, and will be used to 1) complement existing field data: 2) help guide the progress,of future data taking, 3) improve our ability to calibrate and refine alarm algorithms, 4) verify the causes of effects seen in the field, and 5) look for unknown effects not corresponding to theoretical models. A large set of simulated data that has been validated against field data will allow for indepth testing of detection alarm algorithms for a variety of. source scenarios. C1 Pacific NW Natl Lab, Richland, WA 99352 USA. RP Robinson, SM (reprint author), Pacific NW Natl Lab, Richland, WA 99352 USA. NR 5 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1082-3654 BN 0-7803-9221-3 J9 IEEE NUCL SCI CONF R PY 2005 BP 1014 EP 1018 PG 5 WC Instruments & Instrumentation; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Instruments & Instrumentation; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA BFH22 UT WOS:000241851901089 ER PT S AU Bell, ZW Pozzi, SA Padovani, E AF Bell, Zane W. Pozzi, Sara A. Padovani, Enrico BE Yu, B TI Monte Carlo analysis of energy deposition in a cryogenic neutron detector SO 2005 IEEE Nuclear Science Symposium Conference Record, Vols 1-5 SE IEEE NUCLEAR SCIENCE SYMPOSIUM - CONFERENCE RECORD LA English DT Proceedings Paper CT Nuclear Science Symposium/Medical Imaging Conference CY OCT 23-29, 2005 CL Fajardo, PR SP IEEE Nucl & Plasma Sci Soc, Brookhaven Natl Lab, CEA Saclay, DOE, CERN, Lawrence Berkeley Natl Lab, Lawrence Livermore Natl Lab, Stanford Linear Accelerator Ctr, Univ Calif Davis, Univ Washington ID TRANSITION-EDGE SENSOR; MICROCALORIMETER AB In this paper we present the results of modeling the absorption of neutrons in blocks of B-10 and (LiF)-Li-6 with the MCNP-PoliMi code. MCNP-PoliMi correctly links secondary gamma ray production to the neutron interaction type and permits an accurate accounting of the energy deposited as a result of capture reactions (kinetic energy of reaction products), the energy deposited by recoiling ions (elastic and inelastic scattering), and the energy deposited by de-excitation gammas resulting from inelastic scattering on an event-by-event basis. The response to spontaneous fission sources, as well as monoenergetic sources, is presented. C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Bell, ZW (reprint author), Oak Ridge Natl Lab, POB 2008, Oak Ridge, TN 37831 USA. OI Bell, Zane/0000-0003-1115-8674 NR 9 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1082-3654 BN 0-7803-9221-3 J9 IEEE NUCL SCI CONF R PY 2005 BP 1057 EP 1061 PG 5 WC Instruments & Instrumentation; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Instruments & Instrumentation; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA BFH22 UT WOS:000241851901098 ER PT S AU Jarman, KD Smith, LE Heredia-Langner, A Renholds, AR Kaye, W Miller, SD AF Jarman, Kenneth D. Smith, L. Eric Heredia-Langner, Alejandro Renholds, Andrea R. Kaye, William Miller, Steven D. BE Yu, B TI Optimal design of passive gamma-ray spectrometers SO 2005 IEEE Nuclear Science Symposium Conference Record, Vols 1-5 SE IEEE NUCLEAR SCIENCE SYMPOSIUM - CONFERENCE RECORD LA English DT Proceedings Paper CT Nuclear Science Symposium/Medical Imaging Conference CY OCT 23-29, 2005 CL Fajardo, PR SP IEEE Nucl & Plasma Sci Soc, Brookhaven Natl Lab, CEA Saclay, DOE, CERN, Lawrence Berkeley Natl Lab, Lawrence Livermore Natl Lab, Stanford Linear Accelerator Ctr, Univ Calif Davis, Univ Washington AB Passive gamma-ray spectrometers composed of attenuation filters and integrating detector materials provide important advantages in terms of zero-power operation and ruggedness for long-term monitoring scenarios (e.g. national security or environmental remediation). However, the many design parameters, including attenuation filter material and thickness and number of pixels (filter/integrating material combinations), present a challenging optimization problem in designing spectrometers for different applications. In many of these applications, the goal is simply one of anomaly detection-deciding that there is a gamma-ray source not normally found in the nuisance source populations of that particular measurement environment. A passive spectrometer design study approach using an anomaly detection metric is presented here, and is founded on "injecting" target sources of interest (e.g. Co-57, Ba-133, Cs-137) into a nuisance source population that represents the widely varying backgrounds typical of long-term monitoring scenarios. The design evaluation metric is quantified by the probability of detection given a required probability of false alarm. A genetic algorithm employs this metric to probe the large design space and identify superior spectrometer designs. C1 Pacific NW Natl Lab, Richland, WA 99352 USA. RP Jarman, KD (reprint author), Pacific NW Natl Lab, POB 999, Richland, WA 99352 USA. RI Jarman, Kenneth/B-6157-2011 OI Jarman, Kenneth/0000-0002-4396-9212 NR 9 TC 1 Z9 1 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1082-3654 BN 0-7803-9221-3 J9 IEEE NUCL SCI CONF R PY 2005 BP 1062 EP 1066 PG 5 WC Instruments & Instrumentation; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Instruments & Instrumentation; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA BFH22 UT WOS:000241851901099 ER PT S AU Fairfield, JA AF Fairfield, Jessamyn A. BE Yu, B TI Improved spatial resolution in thick, fully-depleted CCDs with enhanced red sensitivity SO 2005 IEEE Nuclear Science Symposium Conference Record, Vols 1-5 SE IEEE NUCLEAR SCIENCE SYMPOSIUM - CONFERENCE RECORD LA English DT Proceedings Paper CT Nuclear Science Symposium/Medical Imaging Conference CY OCT 23-29, 2005 CL Fajardo, PR SP IEEE Nucl & Plasma Sci Soc, Brookhaven Natl Lab, CEA Saclay, DOE, CERN, Lawrence Berkeley Natl Lab, Lawrence Livermore Natl Lab, Stanford Linear Accelerator Ctr, Univ Calif Davis, Univ Washington AB The point spread function (PSF) is an important measure of spatial resolution in CCDs for point-like objects, since it can affect use in imaging and spectroscopic applications. We present new data and theoretical developments in the study of lateral charge diffusion in thick, fully-depleted charge-coupled devices (CCDs) developed at Lawrence Berkeley National Laboratory (LBNL). Because they are fully depleted, the LBNL devices have no field-free region, and diffusion can be controlled through the application of an external bias voltage. We give results for a 3512x3512 format, 10.5 mu m pixel back-illuminated p-channel CCD developed for the SuperNova/ Acceleration Probe (SNAP), a proposed satellite-based experiment designed to study dark energy. The PSF was measured at substrate bias voltages between 3 V and 115 V. At a bias voltage of 115V, we measure an rms diffusion of 3.7 +/- 0.2 mu m. Lateral charge diffusion in LBNL CCDs is thus expected to meet the SNAP requirements. C1 Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. RP Fairfield, JA (reprint author), Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. OI Fairfield, Jessamyn/0000-0002-2143-9077 NR 5 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1082-3654 BN 0-7803-9221-3 J9 IEEE NUCL SCI CONF R PY 2005 BP 1072 EP 1076 PG 5 WC Instruments & Instrumentation; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Instruments & Instrumentation; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA BFH22 UT WOS:000241851901101 ER PT S AU Stanitzki, M AF Stanitzki, Marcel BE Yu, B TI Operational experience with the CDF RUN II silicon detector SO 2005 IEEE Nuclear Science Symposium Conference Record, Vols 1-5 SE IEEE NUCLEAR SCIENCE SYMPOSIUM - CONFERENCE RECORD LA English DT Proceedings Paper CT Nuclear Science Symposium/Medical Imaging Conference CY OCT 23-29, 2005 CL Fajardo, PR SP IEEE Nucl & Plasma Sci Soc, Brookhaven Natl Lab, CEA Saclay, DOE, CERN, Lawrence Berkeley Natl Lab, Lawrence Livermore Natl Lab, Stanford Linear Accelerator Ctr, Univ Calif Davis, Univ Washington AB The CDF (Collider Detector at Fermilab) Silicon Vertex detector consists of three subdetectors: SVX-II, ISL and LOO. Altogether it consists of 8 layers of Silicon with more than 720000 readout channels. This detector is essential for CDF's high precision tracking. It is also vital for the forward tracking capabilities and the identification of heavy flavour decays. After four years of data taking in Run-II and a delivered luminosity of more than 1.2 fb(-1), a summary of the operational experiences with a silicon detector at CDF is given. Besides being very important for the tracking, the Silicon detector also plays a vital role in Level 2 decision of the CDF Trigger system. Finally, aspects of the longevity of this detector and the impact on the CDF physics programme are presented. C1 Yale Univ, CDF MS 318, Fermilab, Batavia, IL 60510 USA. RP Stanitzki, M (reprint author), Yale Univ, CDF MS 318, Fermilab, POB 500, Batavia, IL 60510 USA. NR 9 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1082-3654 BN 0-7803-9221-3 J9 IEEE NUCL SCI CONF R PY 2005 BP 1101 EP 1105 PG 5 WC Instruments & Instrumentation; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Instruments & Instrumentation; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA BFH22 UT WOS:000241851901108 ER PT S AU Li, Z Verbitskaya, E Eremin, V Ivanov, A Harkonen, J Tuovinen, E Luukka, P AF Li, Zheng Verbitskaya, E. Eremin, V. Ivanov, A. Harkonen, J. Tuovinen, E. Luukka, P. BE Yu, B TI Detector recovery/improvement via elevated-temperature-annealing (DRIVE) - A new approach for Si detector applications in high radiation environment in SLHC SO 2005 IEEE Nuclear Science Symposium Conference Record, Vols 1-5 SE IEEE NUCLEAR SCIENCE SYMPOSIUM - CONFERENCE RECORD LA English DT Proceedings Paper CT Nuclear Science Symposium/Medical Imaging Conference CY OCT 23-29, 2005 CL Fajardo, PR SP IEEE Nucl & Plasma Sci Soc, Brookhaven Natl Lab, CEA Saclay, DOE, CERN, Lawrence Berkeley Natl Lab, Lawrence Livermore Natl Lab, Stanford Linear Accelerator Ctr, Univ Calif Davis, Univ Washington ID IRRADIATED SILICON DETECTORS; N-EFF; NEUTRON; RESISTIVITY; PROTON AB A new approach to improve Si detector radiation hardness/tolerance, termed as DRIVE (Detector Recovery/Improvement Via Elevated-temperature-annealing), has been realized by annealing of oxygen-rich (magnetic CZ, MCZ), proton-irradiated Si detectors (with negative space charge before annealing) at medium temperature for a few hours. The DRIVE approach has been proved to lead to the dramatic decrease in detector leakage current, decrease in detector negative space charge concentration, and an eventual space charge sign inversion from negative to positive. Defect studies have shown significant reduction in overall defect concentrations after annealing. C1 Brookhaven Natl Lab, Upton, NY 11973 USA. RP Li, Z (reprint author), Brookhaven Natl Lab, Upton, NY 11973 USA. RI Verbitskaya, Elena/D-1521-2014 NR 13 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1082-3654 BN 0-7803-9221-3 J9 IEEE NUCL SCI CONF R PY 2005 BP 1106 EP 1111 PG 6 WC Instruments & Instrumentation; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Instruments & Instrumentation; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA BFH22 UT WOS:000241851901109 ER PT S AU Tesarek, RJ D'Auria, S Dong, P Hocker, A Kordas, K McGimpsey, S Nicolas, L Wallny, R Schmitt, W Worm, S AF Tesarek, Richard J. D'Auria, Saverio Dong, Peter Hocker, Andy Kordas, Kostas McGimpsey, Susan Nicolas, Ludovic Wallny, Rainer Schmitt, Wayne Worm, Steven CA CDF Radiation Monitoring Grp BE Yu, B TI Single event effects and their mitigation for the collider detector at Fermilab SO 2005 IEEE Nuclear Science Symposium Conference Record, Vols 1-5 SE IEEE NUCLEAR SCIENCE SYMPOSIUM - CONFERENCE RECORD LA English DT Proceedings Paper CT Nuclear Science Symposium/Medical Imaging Conference CY OCT 23-29, 2005 CL Fajardo, PR SP IEEE Nucl & Plasma Sci Soc, Brookhaven Natl Lab, CEA Saclay, DOE, CERN, Lawrence Berkeley Natl Lab, Lawrence Livermore Natl Lab, Stanford Linear Accelerator Ctr, Univ Calif Davis, Univ Washington DE radiation damage; single event effects; single event upset; single event burn-out; ionizing radiation; radiation field AB We present an overview of radiation induced failures and operational experiences from the Collider Detector at Fermilab (CDF). In our summary, we examine single event effects (SEE) in electronics located in and around the detector. We present results of experiments to identify the sources and composition of the radiation and steps to reduce the rate of SEES in our electronics. Our studies have led to a better, more complete understanding of the radiation environment in a modern hadron collider experiment. C1 Fermilab Natl Accelerator Lab, Batavia, IL 60510 USA. RP Tesarek, RJ (reprint author), Fermilab Natl Accelerator Lab, POB 500, Batavia, IL 60510 USA. NR 11 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1082-3654 BN 0-7803-9221-3 J9 IEEE NUCL SCI CONF R PY 2005 BP 1112 EP 1116 PG 5 WC Instruments & Instrumentation; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Instruments & Instrumentation; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA BFH22 UT WOS:000241851901110 ER PT S AU Derenzo, SE Bourret-Courchesne, E James, FJ Klintenberg, MK Porter-Chapman, Y Wang, J Weber, MJ AF Derenzo, Stephen E. Bourret-Courchesne, Edith James, Floyd J. Klintenberg, Mattias K. Porter-Chapman, Yetta Wang, Jie Weber, Marvin J. BE Yu, B TI Identifying semiconductors by DC ionization conductivity SO 2005 IEEE Nuclear Science Symposium Conference Record, Vols 1-5 SE IEEE NUCLEAR SCIENCE SYMPOSIUM - CONFERENCE RECORD LA English DT Proceedings Paper CT Nuclear Science Symposium/Medical Imaging Conference CY OCT 23-29, 2005 CL Fajardo, PR SP IEEE Nucl & Plasma Sci Soc, Brookhaven Natl Lab, CEA Saclay, DOE, CERN, Lawrence Berkeley Natl Lab, Lawrence Livermore Natl Lab, Stanford Linear Accelerator Ctr, Univ Calif Davis, Univ Washington ID DETECTORS; PBI2 AB We describe a method for identifying semiconductor radiation detector materials based on the mobility of internally generated electrons and holes. It was designed for the early stages of exploration, when samples are not available as single crystals, but as crystalline powders. Samples are confined under pressure in an electric field and semiconductors are identified by an increase in d.c. conductivity during exposure to a high-intensity source of Co-60 gamma rays. Using this method, we have determined that BiOI, PbIF, BiPbO2Cl, BiPbO2Br, BIPbO2I, Bi2GdO4Cl, Pb3O2I2, and Pb5O4I2 are semiconductors. C1 Lawrence Berkeley Lab, Div Life Sci, Berkeley, CA 94720 USA. RP Derenzo, SE (reprint author), Lawrence Berkeley Lab, Div Life Sci, Berkeley, CA 94720 USA. NR 10 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1082-3654 BN 0-7803-9221-3 J9 IEEE NUCL SCI CONF R PY 2005 BP 1132 EP 1134 PG 3 WC Instruments & Instrumentation; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Instruments & Instrumentation; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA BFH22 UT WOS:000241851901114 ER PT S AU Ziock, KP Caffrey, G Lebrun, A Forman, L Vanier, P Wharton, J AF Ziock, Klaus-Peter Caffrey, Gus Lebrun, Alain Forman, Leon Vanier, Peter Wharton, Jason BE Yu, B TI Radiation imaging of dry-storage casks for spent nuclear fuel SO 2005 IEEE Nuclear Science Symposium Conference Record, Vols 1-5 SE IEEE NUCLEAR SCIENCE SYMPOSIUM - CONFERENCE RECORD LA English DT Proceedings Paper CT Nuclear Science Symposium/Medical Imaging Conference CY OCT 23-29, 2005 CL Fajardo, PR SP IEEE Nucl & Plasma Sci Soc, Brookhaven Natl Lab, CEA Saclay, DOE, CERN, Lawrence Berkeley Natl Lab, Lawrence Livermore Natl Lab, Stanford Linear Accelerator Ctr, Univ Calif Davis, Univ Washington ID ARRAYS; IMAGES AB We report the results of a measurement campaign conducted on six dry-storage, spent-nuclear-fuel storage casks at the Idaho National Laboratory. A gamma-ray imager, a thermal-neutron imager and a Ge-spectrometer were used to collect data. The campaign was conducted to examine the feasibility of using cask radiation signatures as unique identifiers for individual casks as part of a safeguards regime. The results clearly show different morphologies for the various cask types although the signatures are deemed insufficient to uniquely identify individual casks of the same type. Based on results with the Ge-spectrometer and differences between thermal neutron images and neutron-dose meters, this result is attributed to the limitations of the extant imagers used, rather than of the basic concept. C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Ziock, KP (reprint author), Oak Ridge Natl Lab, POB 2008, Oak Ridge, TN 37831 USA. NR 11 TC 1 Z9 1 U1 0 U2 3 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1082-3654 BN 0-7803-9221-3 J9 IEEE NUCL SCI CONF R PY 2005 BP 1163 EP 1167 PG 5 WC Instruments & Instrumentation; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Instruments & Instrumentation; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA BFH22 UT WOS:000241851901121 ER PT S AU Hartwell, JK Scates, DM Drigert, MW AF Hartwell, John K. Scates, Dawn M. Drigert, Mark W. BE Yu, B TI Design of an on-line, multi-spectrometer fission product monitoring system (FPMS) to support advanced (gas reactor (AGR) fuel testing and qualification in the advanced test reactor SO 2005 IEEE Nuclear Science Symposium Conference Record, Vols 1-5 SE IEEE NUCLEAR SCIENCE SYMPOSIUM - CONFERENCE RECORD LA English DT Proceedings Paper CT Nuclear Science Symposium/Medical Imaging Conference CY OCT 23-29, 2005 CL Fajardo, PR SP IEEE Nucl & Plasma Sci Soc, Brookhaven Natl Lab, CEA Saclay, DOE, CERN, Lawrence Berkeley Natl Lab, Lawrence Livermore Natl Lab, Stanford Linear Accelerator Ctr, Univ Calif Davis, Univ Washington AB The US Department of Energy (DOE) is embarking on a series of tests of TRIstructural ISOtropic (TRISO) coated-particle reactor fuel for the Advanced Gas Reactor (AGR). As one part of this fuel development program, a series of eight (8) fuel irradiation tests are planned for the Idaho National Laboratory's (INL's) Advanced Test Reactor (ATR). The first test in this series (AGR-1) will incorporate six separate capsules irradiated simultaneously, each containing about 51,000 TRISO-coated fuel particles supported in a graphite matrix and continuously swept with inert gas during irradiation. The effluent gas from each of the six capsules must be independently monitored in near real time and the activity of various fission gas nuclides determined and reported. A set of seven heavily-shielded, high-purity germanium (HPGe) gamma-ray spectrometers and sodium iodide [NaI(TI)] scintillation detector-based total radiation detectors have been designed and are being configured and tested for use during the AGR-1 experiment. The AGR-1 test specification requires that the fission product measurement system (FPMS) have sufficient sensitivity to detect the failure of a single coated fuel particle and sufficient range to allow it to "count" multiple (up to 250) successive particle failures. This paper describes the design and expected performance of the AGR-1 FPMS. C1 Idaho Natl Engn Lab, Idaho Falls, ID 83415 USA. RP Hartwell, JK (reprint author), Idaho Natl Engn Lab, POB 1625, Idaho Falls, ID 83415 USA. NR 10 TC 0 Z9 0 U1 0 U2 2 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1082-3654 BN 0-7803-9221-3 J9 IEEE NUCL SCI CONF R PY 2005 BP 1168 EP 1172 PG 5 WC Instruments & Instrumentation; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Instruments & Instrumentation; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA BFH22 UT WOS:000241851901122 ER PT S AU Schaknowski, NA Smith, GC Yu, B Doumas, J AF Schaknowski, Neil A. Smith, Graham C. Yu, Bo Doumas, Jerry BE Yu, B TI Two-dimensional, He-3 neutron detectors with pad readout for high rates SO 2005 IEEE Nuclear Science Symposium Conference Record, Vols 1-5 SE IEEE NUCLEAR SCIENCE SYMPOSIUM - CONFERENCE RECORD LA English DT Proceedings Paper CT Nuclear Science Symposium/Medical Imaging Conference CY OCT 23-29, 2005 CL Fajardo, PR SP IEEE Nucl & Plasma Sci Soc, Brookhaven Natl Lab, CEA Saclay, DOE, CERN, Lawrence Berkeley Natl Lab, Lawrence Livermore Natl Lab, Stanford Linear Accelerator Ctr, Univ Calif Davis, Univ Washington AB We describe initial results from a new technical approach aimed at providing advanced, two-dimensional, thermal neutron detectors for high rate applications at new facilities such as the Spallation Neutron Source. The concept is based on neutron conversion in He-3. The gas mixture is contained in a grid-less ionization chamber, with the conversion depth bounded by an entrance window and an anode plane comprising discrete pixels, or pads, that are read-out in parallel. Weighting field calculations show that a ratio of gas depth to anode pad spacing of around 7 :1 or greater will permit observation of almost all of the primary ionization on one pad, or a small group of adjacent pads. We illustrate with prototype detector measurements that it should be possible to construct large 1m(2) devices that are capable of sustaining rates up to 10(8)n s(-1), with position resolution of a mm or so. Operating with unity gain, this technique is extremely reliable and should provide advanced solutions to small angle scattering and reflectometry instruments. C1 Brookhaven Natl Lab, Instrumentat Div, Upton, NY 11973 USA. RP Schaknowski, NA (reprint author), Brookhaven Natl Lab, Instrumentat Div, Upton, NY 11973 USA. NR 2 TC 1 Z9 1 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1082-3654 BN 0-7803-9221-3 J9 IEEE NUCL SCI CONF R PY 2005 BP 1201 EP 1204 PG 4 WC Instruments & Instrumentation; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Instruments & Instrumentation; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA BFH22 UT WOS:000241851901129 ER PT S AU De Lurgio, PM Hessler, JP Weizeorick, JT Kreps, AS Molitsky, MJ Naday, I Drake, GR Jennings, G AF De Lurgio, Patrick M. Hessler, Jan P. Weizeorick, John T. Kreps, Andrew S. Molitsky, Michael J. Naday, Istvan Drake, Gary R. Jennings, Guy BE Yu, B TI A new detector for time-resolved small-angle X-ray scattering studies SO 2005 IEEE Nuclear Science Symposium Conference Record, Vols 1-5 SE IEEE NUCLEAR SCIENCE SYMPOSIUM - CONFERENCE RECORD LA English DT Proceedings Paper CT Nuclear Science Symposium/Medical Imaging Conference CY OCT 23-29, 2005 CL Fajardo, PR SP IEEE Nucl & Plasma Sci Soc, Brookhaven Natl Lab, CEA Saclay, DOE, CERN, Lawrence Berkeley Natl Lab, Lawrence Livermore Natl Lab, Stanford Linear Accelerator Ctr, Univ Calif Davis, Univ Washington DE X-ray; synchrotron; front-end electronics; silicon strip detector; small-angle scattering; time-resolved scattering AB Anew detector for Time-Resolved Small-Angle X-Ray Scattering has been designed and built for experiments at the Advanced Photon Source of Argonne National Laboratory. This detector is made from a 500 mu m thick by 150 mm diameter ultra-high purity silicon wafer, which directly converts x-rays into electron-hole pairs. The electrodes are concentric rings that integrate the scattered x-rays over the azimuthal angle. The widths of the rings are optimized for the size of the x-ray beam and its energy spread. Only 128 rings, or channels, are needed to measure a scattering profile. The read-out electronics consist of preamplifiers with pulse-shaping, which are mounted on the detector, and 12-bit, 20 MHz digitizers. The resolving time of the electronics is 300 ns, which is sufficient to isolate a single pulse of scattered x-rays when the synchrotron is operated with a hybrid or asymmetric 611 pattern. The data acquisition hardware can average a programmable number of digital samples, up to 64, every 3.68 mu s (the period of the synchrotron) to provides a single 12-bit average of the voltage from the analog amplifier chain. The temporal range of the detector is 3.68 seconds or longer and may be controlled by the experimenter. An alpha source is used to calibrate the detector and electronics, and document their performance. Preliminary results obtained during the commissioning of the detector are presented. C1 Argonne Natl Lab, Argonne, IL 60439 USA. RP De Lurgio, PM (reprint author), Argonne Natl Lab, 9700 S Cass Ave, Argonne, IL 60439 USA. NR 3 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1082-3654 BN 0-7803-9221-3 J9 IEEE NUCL SCI CONF R PY 2005 BP 1215 EP 1222 PG 8 WC Instruments & Instrumentation; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Instruments & Instrumentation; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA BFH22 UT WOS:000241851901133 ER PT S AU Seifert, A Milbrath, B Pitts, WK Smith, E AF Seifert, Allen Milbrath, Brian Pitts, W. K. Smith, Eric BE Yu, B TI Implementation of a noise mitigation strategy for a high-pressure xenon detector SO 2005 IEEE Nuclear Science Symposium Conference Record, Vols 1-5 SE IEEE NUCLEAR SCIENCE SYMPOSIUM - CONFERENCE RECORD LA English DT Proceedings Paper CT Nuclear Science Symposium/Medical Imaging Conference CY OCT 23-29, 2005 CL Fajardo, PR SP IEEE Nucl & Plasma Sci Soc, Brookhaven Natl Lab, CEA Saclay, DOE, CERN, Lawrence Berkeley Natl Lab, Lawrence Livermore Natl Lab, Stanford Linear Accelerator Ctr, Univ Calif Davis, Univ Washington AB High-pressure xenon (HPXe) detectors have historically been unable to achieve or even approach the theoretically predicted energy resolution, a phenomenon usually attributed to problems with microphonic, vibrational, or acoustic noise. All these noises are expected to have characteristic frequency signatures. We have determined the effects of external acoustic noise signals on the resolution of HPXe spectrometers and implemented a technique to reduce or eliminate the resolution loss caused by external acoustic noise in real time. Using a precision waveform generator as the driver on a 400-watt speaker, we determined the response of a commercial HPXe detector to a variety of constant frequency acoustic noise signals by performing a fast Fourier transform on a buffered detector output signal and noting distortions to the spectral response of the frequency domain. A data acquisition package was developed using the frequency response information to perform realtime digital signal noise filtering on each gamma-ray pulse. With external acoustic noise, the measured resolution of HPXe gamma-ray energy spectra was degraded by a factor of 2 to 3. With the noise mitigating data acquisition package the spectroscopic resolution was restored to values comparable to the resolution measured under ideal (non-noisy) conditions. C1 Pacific NW Natl Lab, Richland, WA 99352 USA. RP Seifert, A (reprint author), Pacific NW Natl Lab, Richland, WA 99352 USA. NR 3 TC 2 Z9 3 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1082-3654 BN 0-7803-9221-3 J9 IEEE NUCL SCI CONF R PY 2005 BP 1262 EP 1266 PG 5 WC Instruments & Instrumentation; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Instruments & Instrumentation; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA BFH22 UT WOS:000241851902011 ER PT S AU Goedeke, SM Hollerman, WA Allison, SW Gray, PA Lewis, LA Smithwick, RW Boatner, LA Glasgow, DC Ivanov, IN Wise, H AF Goedeke, S. M. Hollerman, W. A. Allison, S. W. Gray, P. A. Lewis, L. A. Smithwick, R. W., III Boatner, L. A. Glasgow, D. C. Ivanov, I. N. Wise, H. BE Yu, B TI Cathodoluminescence emission studies for selected phosphor-based sensor materials SO 2005 IEEE Nuclear Science Symposium Conference Record, Vols 1-5 SE IEEE NUCLEAR SCIENCE SYMPOSIUM - CONFERENCE RECORD LA English DT Proceedings Paper CT Nuclear Science Symposium/Medical Imaging Conference CY OCT 23-29, 2005 CL Fajardo, PR SP IEEE Nucl & Plasma Sci Soc, Brookhaven Natl Lab, CEA Saclay, DOE, CERN, Lawrence Berkeley Natl Lab, Lawrence Livermore Natl Lab, Stanford Linear Accelerator Ctr, Univ Calif Davis, Univ Washington ID SINGLE-CRYSTAL AB The current interest in returning to the Moon and Mars by 2030 makes cost effective and low mass health monitoring sensors essential for spacecraft development. In space, there are many surface measurements that are required to monitor the condition of the spacecraft including: surface temperature, radiation dose, and impact. Through the use of phosphors, these conditions can be monitored. Practical space-based phosphor sensors will depend heavily upon research investigating the resistance of phosphors to ionizing radiation and the ability to anneal or self-heal from damage caused by ionizing radiation. The cathodoluminescence (CL) testing was performed using the Low Energy Electron system located at the NASA Marshall Space Flight Center (MSFC) in Huntsville, Alabama. For the materials tested, several interesting results were observed. For most materials, increases in both beam energy and current density improved the CL fluorescence yield. It was also noted that YAG:Nd,Ce has the greatest near infrared intensity for any of the tested materials. The evaluation of dopant concentration in YPO4:Nd showed minimal differences in spectral shape and intensity. While the total electron dose was small, the intention was to maximize the number of irradiated materials. C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Goedeke, SM (reprint author), Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RI ivanov, ilia/D-3402-2015; OI ivanov, ilia/0000-0002-6726-2502; Allison, Stephen/0000-0002-5887-5403; Boatner, Lynn/0000-0002-0235-7594 NR 11 TC 1 Z9 1 U1 0 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1082-3654 BN 0-7803-9221-3 J9 IEEE NUCL SCI CONF R PY 2005 BP 1279 EP 1283 PG 5 WC Instruments & Instrumentation; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Instruments & Instrumentation; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA BFH22 UT WOS:000241851902015 ER PT S AU Pla-Dalmau, A Bross, AD Rykalin, VV Wood, BM AF Pla-Dalmau, Anna Bross, Alan D. Rykalin, Victor V. Wood, Brian M. BE Yu, B TI Extruded plastic scintillator for MINERvA SO 2005 IEEE Nuclear Science Symposium Conference Record, Vols 1-5 SE IEEE NUCLEAR SCIENCE SYMPOSIUM - CONFERENCE RECORD LA English DT Proceedings Paper CT Nuclear Science Symposium/Medical Imaging Conference CY OCT 23-29, 2005 CL Fajardo, PR SP IEEE Nucl & Plasma Sci Soc, Brookhaven Natl Lab, CEA Saclay, DOE, CERN, Lawrence Berkeley Natl Lab, Lawrence Livermore Natl Lab, Stanford Linear Accelerator Ctr, Univ Calif Davis, Univ Washington AB An extrusion line has recently been installed at Fermilab in collaboration with NICADD (Northern Illinois Center for Accelerator and Detector Development). This new facility will serve to further develop and improve extruded plastic scintillator. Since polystyrene is widely used in the consumer industry, the logical path was to investigate the extrusion of commercial-grade polystyrene pellets with dopants to yield high quality plastic scintillator. The D0 and MINOS experiments are already using extruded scintillator strips in their detectors. A new experiment at Fermilab is pursuing the use of extruded plastic scintillator. A new plastic scintillator strip is being tested and its properties characterized. The initial results are presented here. C1 Fermilab Natl Accelerator Lab, Batavia, IL 60510 USA. RP Pla-Dalmau, A (reprint author), Fermilab Natl Accelerator Lab, POB 500, Batavia, IL 60510 USA. NR 3 TC 1 Z9 1 U1 1 U2 2 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1082-3654 BN 0-7803-9221-3 J9 IEEE NUCL SCI CONF R PY 2005 BP 1298 EP 1300 PG 3 WC Instruments & Instrumentation; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Instruments & Instrumentation; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA BFH22 UT WOS:000241851902020 ER PT S AU McIntyre, JI Schrom, B Aalseth, CE Cooper, M Hayes, JC Heimbigner, TR Hossbach, T Hubbard, C Litke, KE Ripplinger, M Seifert, CE Suarez, R AF McIntyre, Justin I. Schrom, Brian Aalseth, Craig E. Cooper, Matthew Hayes, James C. Heimbigner, Tom R. Hossbach, Todd Hubbard, Charlie Litke, Kevin E. Ripplinger, Michael Seifert, Carolyn E. Suarez, Reynold BE Yu, B TI Beta-gamma coincidence counting using an yttrium aluminum perovskit and bismuth germanate phoswich scintillator SO 2005 IEEE Nuclear Science Symposium Conference Record, Vols 1-5 SE IEEE NUCLEAR SCIENCE SYMPOSIUM - CONFERENCE RECORD LA English DT Proceedings Paper CT Nuclear Science Symposium/Medical Imaging Conference CY OCT 23-29, 2005 CL Fajardo, PR SP IEEE Nucl & Plasma Sci Soc, Brookhaven Natl Lab, CEA Saclay, DOE, CERN, Lawrence Berkeley Natl Lab, Lawrence Livermore Natl Lab, Stanford Linear Accelerator Ctr, Univ Calif Davis, Univ Washington AB Phoswich detectors (two scintillators; attached to the same photomultiplier-tube) have been used in the past to measure either betas or gammas separately but were not used to measure beta-gamma coincidence signatures. These coincidence signatures are very important for the detection of many fission products and are exploited to detect four radioxenon isotopes using the Automated Radioxenon Sampler/Analyzer (ARSA) [1]. Previous PNNL work with a phoswich detector used a commercially available, thin disk of scintillating CaF2(Eu) and a 2" thick NaI(TI) crystal in a phoswich arrangement. Studies with this detector measured the beta-gamma coincidence signatures from Xe-133, Pb-214 and Bi-214 [2]. This scintillator combination worked but was not a good match in scintillation light decay times, 940-ns for CaF2(Eu) and 230 ns for NaI(TI). Additionally, a 6-mm thick quartz window was placed between the NaI(TI) and the CaF2 to ensure a hermetic seal for the NaI(TI) crystal. This dead layer significantly reduced the detection probability of the low energy x-rays and gammas that are part of the coincidence signatures for Pb-214, Bi-214 and the radioxenons. Further research showed that Yttrium aluminum perovskit (YAP) and bismuth germanate (BGO) have very good scintillation light characteristics and no hermetic seal requirements. The 27-ns scintillation light decay time of YAP and the 300-ns decay time for BGO are a good match between fast and slow light output. The scintillation light output was measured using XIA (TM) digital signal processing readout electronics, and the fast (YAP) and slow (BGO) light components allowed discrimination between the beta and gamma contributions of the radioactive decays. In this paper we discuss the experimental setup and results obtained with this new phoswich detector and the applications beyond radioxenon gas measurements. A companion paper using plastic scintillator and CsI(Na) has also shown very promising results, [5]. C1 Pacific NW Natl Lab, Richland, WA 99353 USA. RP McIntyre, JI (reprint author), Pacific NW Natl Lab, 902 Battelle Blvd, Richland, WA 99353 USA. RI McIntyre, Justin/P-1346-2014 OI McIntyre, Justin/0000-0002-3706-4310 NR 6 TC 0 Z9 0 U1 0 U2 5 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1082-3654 BN 0-7803-9221-3 J9 IEEE NUCL SCI CONF R PY 2005 BP 1301 EP 1304 PG 4 WC Instruments & Instrumentation; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Instruments & Instrumentation; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA BFH22 UT WOS:000241851902021 ER PT S AU Seifert, CE Orrell, JL Coomes, DE LaMarche, BL Bliss, M Lynn, KG Jones, KA Campi, G AF Seifert, Carolyn E. Orrell, John. L. Coomes, Donald E. LaMarche, Brian L. Bliss, Mary Lynn, Kelvin G. Jones, Kelly A. Campi, Guido BE Yu, B TI Performance of CdZnTe detectors grown by low-pressure Bridgman SO 2005 IEEE Nuclear Science Symposium Conference Record, Vols 1-5 SE IEEE NUCLEAR SCIENCE SYMPOSIUM - CONFERENCE RECORD LA English DT Proceedings Paper CT Nuclear Science Symposium/Medical Imaging Conference CY OCT 23-29, 2005 CL Fajardo, PR SP IEEE Nucl & Plasma Sci Soc, Brookhaven Natl Lab, CEA Saclay, DOE, CERN, Lawrence Berkeley Natl Lab, Lawrence Livermore Natl Lab, Stanford Linear Accelerator Ctr, Univ Calif Davis, Univ Washington AB Recent advances in the growth and doping of CdZnTe using low-pressure Bridgman methods have allowed for the production of high-resistivity crystals. In this work, we present electrical characterization measurements on samples of CdZnTe grown at Washington State University. We demonstrate the capabilities of the CdZnTe material to perform as radiation detectors and correlate detector performance with crystal growth conditions. C1 Pacific NW Natl Lab, Richland, WA 99352 USA. RP Seifert, CE (reprint author), Pacific NW Natl Lab, Richland, WA 99352 USA. RI Bliss, Mary/G-2240-2012 OI Bliss, Mary/0000-0002-7565-4813 NR 0 TC 0 Z9 0 U1 0 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1082-3654 BN 0-7803-9221-3 J9 IEEE NUCL SCI CONF R PY 2005 BP 1383 EP 1385 PG 3 WC Instruments & Instrumentation; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Instruments & Instrumentation; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA BFH22 UT WOS:000241851902039 ER PT S AU Chen, W Beuttenmuller, RH Elliott, DC Fried, J DeGeronimo, G Li, Z O'Connor, P Pinelli, DA Radeka, V Rehak, P Smith, GC Wall, JS Yu, B AF Chen, W. Beuttenmuller, R. H. Elliott, D. C. Fried, J. DeGeronimo, G. Li, Z. O'Connor, P. Pinelli, D. A. Radeka, V. Rehak, P. Smith, G. C. Wall, J. S. Yu, B. BE Yu, B TI Development of X-ray active matrix pixel sensors for detection of electrons in scanning transmission electron microscope SO 2005 IEEE NUCLEAR SCIENCE SYMPOSIUM CONFERENCE RECORD, VOLS 1-5 SE IEEE Nuclear Science Symposium Conference Record LA English DT Proceedings Paper CT Nuclear Science Symposium/Medical Imaging Conference CY OCT 23-29, 2005 CL Fajardo, PR SP IEEE Nucl & Plasma Sci Soc, Brookhaven Natl Lab, CEA Saclay, DOE, CERN, Lawrence Berkeley Natl Lab, Lawrence Livermore Natl Lab, Stanford Linear Accelerator Ctr, Univ Calif Davis, Univ Washington ID HIGH-RESISTIVITY SILICON AB A method developed to produce an X-ray Active Matrix Pixel Sensor (XAMPS) is reported. Several problems had been encountered during the production, but solutions to all of them were found. We will present the design of the detector, justifying the choice of high resistivity silicon as the material for XAMPS. Production processing will be described with emphasis on encountered problems and their solutions. The detectors were produced and one of them was tested within the BNL Scanning Transmission Electron Microscope (STEM) for recording data. C1 Brookhaven Natl Lab, Upton, NY 11973 USA. RP Chen, W (reprint author), Brookhaven Natl Lab, Upton, NY 11973 USA. EM weichen@bnl.gov; rehak@bnl.gov NR 7 TC 0 Z9 1 U1 0 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1082-3654 BN 0-7803-9221-3 J9 IEEE NUCL SCI CONF R PY 2005 BP 1431 EP 1435 PG 5 WC Instruments & Instrumentation; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Instruments & Instrumentation; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA BFH22 UT WOS:000241851902051 ER PT S AU Mascarenhas, N Lund, J Peel, J Sunnarborg, D AF Mascarenhas, Nicholas Lund, James Peel, Justin Sunnarborg, Duane BE Yu, B TI Development of a directional 14 MeV neutron detector using scintillating fibers SO 2005 IEEE Nuclear Science Symposium Conference Record, Vols 1-5 SE IEEE NUCLEAR SCIENCE SYMPOSIUM - CONFERENCE RECORD LA English DT Proceedings Paper CT Nuclear Science Symposium/Medical Imaging Conference CY OCT 23-29, 2005 CL Fajardo, PR SP IEEE Nucl & Plasma Sci Soc, Brookhaven Natl Lab, CEA Saclay, DOE, CERN, Lawrence Berkeley Natl Lab, Lawrence Livermore Natl Lab, Stanford Linear Accelerator Ctr, Univ Calif Davis, Univ Washington AB We have developed a directional detector for 14 MeV neutrons. The detector consists of an 8x8 array of plastic scintillating fibers coupled to a multi-anode photomultiplier tube. Protons in the fibers are scattered by incident neutrons and are detected as they pass through multiple fibers. The direction of the flux of incident neutrons is determined using the energy and direction of the recoil proton. The advantages of the detector are its small size and ability to detect fast neutrons. We used GEANT4 to simulate the detector performance, and report the results of experimental studies with neutrons from a 14 MeV pulsed D-T neutron generator. C1 Sandia Natl Labs, Livermore, CA 94550 USA. RP Mascarenhas, N (reprint author), Sandia Natl Labs, Livermore, CA 94550 USA. NR 7 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1082-3654 BN 0-7803-9221-3 J9 IEEE NUCL SCI CONF R PY 2005 BP 1515 EP 1518 PG 4 WC Instruments & Instrumentation; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Instruments & Instrumentation; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA BFH22 UT WOS:000241851902068 ER PT S AU Aykac, D Price, JR Wall, JS AF Aykac, Deniz Price, Jeffery R. Wall, Jonathan S. BE Yu, B TI 3D segmentation of the mouse spleen in microCT via active contours SO 2005 IEEE NUCLEAR SCIENCE SYMPOSIUM CONFERENCE RECORD, VOLS 1-5 SE IEEE Nuclear Science Symposium Conference Record LA English DT Proceedings Paper CT Nuclear Science Symposium/Medical Imaging Conference CY OCT 23-29, 2005 CL Fajardo, PR SP IEEE Nucl & Plasma Sci Soc, Brookhaven Natl Lab, CEA Saclay, DOE, CERN, Lawrence Berkeley Natl Lab, Lawrence Livermore Natl Lab, Stanford Linear Accelerator Ctr, Univ Calif Davis, Univ Washington DE level sets; active contours; 3D segmentation; microCT; spleen AB We present in this paper a novel method for 3D segmentation of the mouse spleen in x-ray CT (microCT) data. Our approach is based upon the 2D "active contours for smooth without edges" algorithm. We introduce a simple statistical weighting scheme that improves region contrast and segmentation performance. We extend the 2D approach to 3D by slice-to-slice processing, including the 31) flow of image statistics. The technique requires no training and operates semiautomatically, requiring only the entry of a single seed point within the spleen. Results are shown that demonstrate the effectiveness of our approach. C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Aykac, D (reprint author), Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. EM aykacdb@ornl.gov; pricejr@ornl.gov; jwall@mc.utmck.edu NR 8 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1082-3654 BN 0-7803-9221-3 J9 IEEE NUCL SCI CONF R PY 2005 BP 1542 EP 1545 PG 4 WC Instruments & Instrumentation; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Instruments & Instrumentation; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA BFH22 UT WOS:000241851902074 ER PT S AU Huber, JS Choong, WS Moses, WW Qi, J Hu, J Wang, GC Wilson, D Oh, S Huesman, RH Derenzo, SE AF Huber, J. S. Choong, W. S. Moses, W. W. Qi, J. Hu, J. Wang, G. C. Wilson, D. Oh, S. Huesman, R. H. Derenzo, S. E. BE Yu, B TI Characterization of a PET camera optimized for prostate imaging SO 2005 IEEE Nuclear Science Symposium Conference Record, Vols 1-5 SE IEEE NUCLEAR SCIENCE SYMPOSIUM - CONFERENCE RECORD LA English DT Proceedings Paper CT Nuclear Science Symposium/Medical Imaging Conference CY OCT 23-29, 2005 CL Fajardo, PR SP IEEE Nucl & Plasma Sci Soc, Brookhaven Natl Lab, CEA Saclay, DOE, CERN, Lawrence Berkeley Natl Lab, Lawrence Livermore Natl Lab, Stanford Linear Accelerator Ctr, Univ Calif Davis, Univ Washington ID DESIGN AB We present the characterization of a positron emission tomograph for prostate imaging that centers a patient between a pair of external curved detector banks (ellipse: 45 cm minor, 70 cm major axis). The distance between detector banks adjusts to allow patient access and to position the detectors as closely as possible for maximum sensitivity with patients of various sizes. Each bank is composed of two axial rows of 20 HR+ block detectors for a total of 80 detectors in the camera. The individual detectors are angled in the transaxial plane to point towards the prostate to reduce resolution degradation in that region. The detectors are read out by modified HRRT data acquisition electronics. Compared to a standard whole-body PET camera, our dedicated-prostate camera has the same sensitivity and resolution, less background (less randoms and lower scatter fraction) and a lower cost. We have completed construction of the camera. Characterization data and reconstructed images of several phantoms are shown. Sensitivity of a point source in the center is 946 cps/mu Ci. Spatial resolution is 4 mm FWHM in the central region. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Huber, JS (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Mailstop 55-121,1 Cycltron Rd, Berkeley, CA 94720 USA. NR 9 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1082-3654 BN 0-7803-9221-3 J9 IEEE NUCL SCI CONF R PY 2005 BP 1556 EP 1559 PG 4 WC Instruments & Instrumentation; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Instruments & Instrumentation; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA BFH22 UT WOS:000241851902077 ER PT S AU Weisenberger, AG Lee, Z Majewski, S Kross, B Popov, V Welch, B Wojcik, R Zorn, C AF Weisenberger, A. G. Lee, Z. Majewski, S. Kross, B. Popov, V. Welch, B. Wojcik, R. Zorn, C. BE Yu, B TI Development of a triple modality small animal planar imaging system SO 2005 IEEE Nuclear Science Symposium Conference Record, Vols 1-5 SE IEEE NUCLEAR SCIENCE SYMPOSIUM - CONFERENCE RECORD LA English DT Proceedings Paper CT Nuclear Science Symposium/Medical Imaging Conference CY OCT 23-29, 2005 CL Fajardo, PR SP IEEE Nucl & Plasma Sci Soc, Brookhaven Natl Lab, CEA Saclay, DOE, CERN, Lawrence Berkeley Natl Lab, Lawrence Livermore Natl Lab, Stanford Linear Accelerator Ctr, Univ Calif Davis, Univ Washington ID ULTRA-HIGH-RESOLUTION; PINHOLE SPECT; DETECTOR AB Recently small animal research utilizing nuclear medicine based imaging has been combined with structural anatomical imaging from x-ray radiography providing a powerful tool for animal researchers. The addition of a third modality is the goal of our instrumentation development. Thomas Jefferson National Accelerator Facility and Case Western Reserve University have been collaborating on the development of a planar imaging system which in addition to radiopharmaccutical based functional imaging and x-ray radiography structural imaging also allows for the in vivo bioluminescence imaging thus providing another functional imaging modality. For the gamma camera we use is a Hamamatsu position sensitive photomultiplier tube coupled to a pixellated NaI(TI) scintillator array with individual crystal elements 1 mm x 1 mm x 5 mm in size and a 0.25 mm septum between each element. The gamma camera has a 10 cm diameter active area and can be used for I-125, T-99m and In-111 radionuclide imaging. To acquire anatomical information we are using a Rad-Icon Shad-o-Box x-ray detector that provides a field of view of 5 cm x 10 cm. The x-ray source is a Source-Ray compact x-ray generator. We are using a Princeton Instruments cooled CCD based detector for the imaging of the bio-distribution of bioluminescence. All three imaging instruments will be integrated into a single light tight/x-ray tight enclosure. C1 Jefferson Lab, Newport News, VA USA. RP Weisenberger, AG (reprint author), Jefferson Lab, Newport News, VA USA. NR 12 TC 1 Z9 1 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1082-3654 BN 0-7803-9221-3 J9 IEEE NUCL SCI CONF R PY 2005 BP 1761 EP 1764 PG 4 WC Instruments & Instrumentation; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Instruments & Instrumentation; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA BFH22 UT WOS:000241851902123 ER PT S AU Tran, VH Smith, MF Meikle, SR Welch, BL Goddard, JS Baba, JS Weisenberger, AG AF Tran, V. H. Smith, M. F. Meikle, S. R. Welch, B. L. Goddard, J. S. Baba, J. S. Weisenberger, A. G. BE Yu, B TI Geometry calibration of a dual headed SPECT system, with rocking motion correction, for small animal imaging SO 2005 IEEE Nuclear Science Symposium Conference Record, Vols 1-5 SE IEEE NUCLEAR SCIENCE SYMPOSIUM - CONFERENCE RECORD LA English DT Proceedings Paper CT Nuclear Science Symposium/Medical Imaging Conference CY OCT 23-29, 2005 CL Fajardo, PR SP IEEE Nucl & Plasma Sci Soc, Brookhaven Natl Lab, CEA Saclay, DOE, CERN, Lawrence Berkeley Natl Lab, Lawrence Livermore Natl Lab, Stanford Linear Accelerator Ctr, Univ Calif Davis, Univ Washington ID PINHOLE SPECT AB A method for simultaneous geometry calibration of a dual detector SPELT system for small animal imaging is presented. For multi-headed SPELT systems, it is desirable that all detectors are calibrated with respect to a common spatial coordinate system, so that projection data from both detectors can be used to reconstruct the common object in the same image space. We adapted Beque's geometry calibration procedure. We show that the procedure can be applied to a dual-headed imaging system by optimizing the combined objective function. Initially, the measured and predicted paths of calibration point sources had significant systematic differences which were dominant in the axial direction. The problem was caused by flexing of the gantry support due to the heavy weight of the detectors. While various correction models of different complexity and assumptions could be applied, we found that the errors were corrected well by including an angle-dependent sinusoidal function to the z-coordinate, which is in the axial direction. C1 Thomas Jefferson Natl Accelerator Facil, Newport News, VA 23606 USA. RP Tran, VH (reprint author), Thomas Jefferson Natl Accelerator Facil, Newport News, VA 23606 USA. RI Meikle, Steven/A-5470-2009 OI Meikle, Steven/0000-0001-7397-0364 NR 4 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1082-3654 BN 0-7803-9221-3 J9 IEEE NUCL SCI CONF R PY 2005 BP 2089 EP 2093 PG 5 WC Instruments & Instrumentation; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Instruments & Instrumentation; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA BFH22 UT WOS:000241851903059 ER PT S AU Huber, JS Moses, WW Pouliot, J Hsu, IC AF Huber, J. S. Moses, W. W. Pouliot, J. Hsu, I. C. BE Yu, B TI Dual-modality PET/ultrasound imaging of the prostate SO 2005 IEEE Nuclear Science Symposium Conference Record, Vols 1-5 SE IEEE NUCLEAR SCIENCE SYMPOSIUM - CONFERENCE RECORD LA English DT Proceedings Paper CT Nuclear Science Symposium/Medical Imaging Conference CY OCT 23-29, 2005 CL Fajardo, PR SP IEEE Nucl & Plasma Sci Soc, Brookhaven Natl Lab, CEA Saclay, DOE, CERN, Lawrence Berkeley Natl Lab, Lawrence Livermore Natl Lab, Stanford Linear Accelerator Ctr, Univ Calif Davis, Univ Washington ID DESIGN AB Functional imaging with positron emission tomography (PET) will detect malignant tumors in the prostate and/or prostate bed, as well as possibly help determine tumor "aggressiveness." However, the relative uptake in a prostate tumor can be so great that few other anatomical landmarks are visible in a PET image. Ultrasound imaging with a transrectal probe provides anatomical detail in the prostate region that can be co-registered with the sensitive functional information from the PET imaging. Imaging the prostate with both PET and transrectal ultrasound (TRUS) will help determine the location of any cancer within the prostate region. This dual-modality imaging should help provide better detection and treatment of prostate cancer. LBNL has built a high performance positron emission tomograph optimized to image the prostate. Compared to a standard whole-body PET camera, our prostate-optimized PET camera has the same sensitivity and resolution, less backgrounds and lower cost. We plan to develop the hardware and software tools needed for a validated dual PET/TRUS prostate imaging system. We also plan to develop dual prostate imaging with PET and external transabdominal ultrasound, in case the TRUS system is too uncomfortable for some patients. We present the design and intended clinical uses for these dual imaging systems. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Huber, JS (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Mailstop 55-121,1 Cyclotron Rd, Berkeley, CA 94720 USA. NR 11 TC 2 Z9 2 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1082-3654 BN 0-7803-9221-3 J9 IEEE NUCL SCI CONF R PY 2005 BP 2187 EP 2190 PG 4 WC Instruments & Instrumentation; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Instruments & Instrumentation; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA BFH22 UT WOS:000241851903081 ER PT S AU Reutter, BW Oh, S Gullberg, GT Huesman, RH AF Reutter, Bryan W. Oh, Sang Gullberg, Grant T. Huesman, Ronald H. BE Yu, B TI Improved quantitation of dynamic SPECT via fully 4-d joint estimation of compartmental models and blood input function directly from projections SO 2005 IEEE NUCLEAR SCIENCE SYMPOSIUM CONFERENCE RECORD, VOLS 1-5 SE IEEE Nuclear Science Symposium Conference Record LA English DT Proceedings Paper CT Nuclear Science Symposium/Medical Imaging Conference CY OCT 23-29, 2005 CL Fajardo, PR SP IEEE Nucl & Plasma Sci Soc, Brookhaven Natl Lab, CEA Saclay, DOE, CERN, Lawrence Berkeley Natl Lab, Lawrence Livermore Natl Lab, Stanford Linear Accelerator Ctr, Univ Calif Davis, Univ Washington ID KINETIC-PARAMETER ESTIMATION; SPATIOTEMPORAL DISTRIBUTIONS; RECONSTRUCTION AB Quantitative kinetic analysis of dynamic cardiac single-photon emission computed tomography (SPECT) data provides unique information that can enable improved discrimination between healthy and diseased tissue, compared to static imaging. In particular, compartmental model analysis can provide quantitative measures of myocardial perfusion, viability, and coronary How reserve. In this work we investigate whether precision of kinetic parameter estimates is improved by additional temporal regularization provided by estimating compartmental models directly from projection data, rather than using "semidirect" methods that estimate time-activity curves first and then fit compartmental models to the curves. Methods are implemented to accelerate fully 4-D direct joint estimation of compartmental models for tissue volumes and B-spline time-activity curves for the blood input and other volumes that do not obey a compartmental model. Computer simulations of a dynamic (99m)Tc-teboroxime cardiac SPECT study show that the additional temporal regularization provided by direct compartmental modeling results in improved precision of parameter estimates, as well as comparable or improved accuracy. Notably, for small myocardial defects the sample standard deviation of uptake and washout parameters was reduced by 17-41%. These results suggest that direct joint estimation of compartmental models and blood input function can improve quantitation of dynamic SPECT. These methods can also be applied to dynamic positron emission tomography (PET). C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Dept Funct Imaging, Berkeley, CA 94720 USA. RP Reutter, BW (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Dept Funct Imaging, Berkeley, CA 94720 USA. EM bwreutter@lbl.gov NR 16 TC 8 Z9 8 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1082-3654 BN 0-7803-9221-3 J9 IEEE NUCL SCI CONF R PY 2005 BP 2337 EP 2341 PG 5 WC Instruments & Instrumentation; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Instruments & Instrumentation; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA BFH22 UT WOS:000241851903115 ER PT S AU Sitek, A Klein, GJ Reutter, BW Huesman, RH Gullberg, GT AF Sitek, Arkadiusz Klein, Gregory J. Reutter, Bryan W. Huesman, Ronald H. Gullberg, Grant T. BE Yu, B TI Measurement of the biomechanics of 3-D cardiac function with gated nuclear medicine studies SO 2005 IEEE Nuclear Science Symposium Conference Record, Vols 1-5 SE IEEE NUCLEAR SCIENCE SYMPOSIUM - CONFERENCE RECORD LA English DT Proceedings Paper CT Nuclear Science Symposium/Medical Imaging Conference CY OCT 23-29, 2005 CL Fajardo, PR SP IEEE Nucl & Plasma Sci Soc, Brookhaven Natl Lab, CEA Saclay, DOE, CERN, Lawrence Berkeley Natl Lab, Lawrence Livermore Natl Lab, Stanford Linear Accelerator Ctr, Univ Calif Davis, Univ Washington DE gated; cardiac; SPECT; PET; biomechanics AB A new model to quantify functional and structural parameters of the myocardium from gated SPECT or PET data was developed. The model consisted of a set of nodes that move with the deformation of the left ventricle. Initially node positions were determined automatically using the prolatespheroidal transform of an image of the left ventricle in, a single gate of the cardiac cycle. The nodes were connected creating a set of tetrahedral volume elements that filled the space of the left ventricular muscle. Next, optimum node positions in each gate and node intensities were determined by least squares fitting the model intensities at each node for each gate to the measured data. The optimization of the node placements was driven by the gated nuclear medicine images with the optimization procedure regularized by constraining: (1) local cardiac muscle incompressibility, (2) fiber extension uniformity over the entire myocardium, and (3) smoothness of the node trajectories over time and space. We used microPET (18)FDG-rat data to test our method by determining optimum positions for 774 nodes (3040 elements) in eight gates. Values of node intensities unchanged between the gates were also determined. In addition to blood pool volumes, the quantitative parameters describing cardiac biomechanics of myocardium volumes, regional fiber stretch values, and regional wall thickening values were also measured. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94597 USA. RP Sitek, A (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, 1 Cyclotron Rd MS55R0121, Berkeley, CA 94597 USA. OI Sitek, Arkadiusz/0000-0002-0677-4002 NR 6 TC 3 Z9 3 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1082-3654 BN 0-7803-9221-3 J9 IEEE NUCL SCI CONF R PY 2005 BP 2346 EP 2349 PG 4 WC Instruments & Instrumentation; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Instruments & Instrumentation; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA BFH22 UT WOS:000241851903117 ER PT S AU Hu, JC Sitek, A Reutter, BW Huesman, RH Gullberg, GT AF Hu, Jicun Sitek, Arkadiusz Reutter, Bryan W. Huesman, Ronald H. Gullberg, Grant T. BE Yu, B TI A new approach of dynamic pinhole SPECT imaging for evaluation of sympathetic nervous system function in animal models of cardiac hypertrophy SO 2005 IEEE Nuclear Science Symposium Conference Record, Vols 1-5 SE IEEE NUCLEAR SCIENCE SYMPOSIUM - CONFERENCE RECORD LA English DT Proceedings Paper CT Nuclear Science Symposium/Medical Imaging Conference CY OCT 23-29, 2005 CL Fajardo, PR SP IEEE Nucl & Plasma Sci Soc, Brookhaven Natl Lab, CEA Saclay, DOE, CERN, Lawrence Berkeley Natl Lab, Lawrence Livermore Natl Lab, Stanford Linear Accelerator Ctr, Univ Calif Davis, Univ Washington ID RECONSTRUCTION AB Typically I-123-MIBG is used for the study of innervation and function of the sympathetic nervous system in heart failure. The protocol involves two studies: first a planar or SPECT scan is performed to measure initial uptake of the tracer, followed some 3-4 hours later by another study measuring the wash-out of the tracer from the heart. A fast wash-out is indicative of a compromised heart. In this work, a dual head pinhole SPECT system was used for imaging the distribution and kinetics of I-123-MIBG in the myocardium of spontaneous hypertensive rats (SHR) and normotensive Wistar Kyoto (WKY) rats. The system geometry was calibrated based on a nonlinear point projection fitting method using a three-point source phantom. The angle variation effect of the parameters was modeled with a sinusoidal function. A dynamic acquisition was performed by injecting I-123-MIBG into rats immediately after starting the data acquisition. The detectors rotated continuously traversing 3601 every 90 seconds. We applied the FADS method to obtain time activity curves in the blood pool and myocardium. Since the initial injection bolus is too fast to obtain a consistent tomographic data set in the first minute of the study, we applied the FADS method directly to projections during the first rotation. In the future, the method will be applied to determine if there are differences in the kinetics between SHR and WKY rats. This approach requires less time by replacing the delayed scan at 3-4 hours after injection with a dynamic acquisition of 90 to 120 minutes. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Dept Med Nucl & Funct Imaging, Berkeley, CA 94720 USA. RP Hu, JC (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Dept Med Nucl & Funct Imaging, Berkeley, CA 94720 USA. OI Sitek, Arkadiusz/0000-0002-0677-4002 NR 7 TC 4 Z9 4 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1082-3654 BN 0-7803-9221-3 J9 IEEE NUCL SCI CONF R PY 2005 BP 2542 EP 2546 PG 5 WC Instruments & Instrumentation; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Instruments & Instrumentation; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA BFH22 UT WOS:000241851904023 ER PT S AU Vaska, P Bolotnikov, A Carini, G Camarda, G Pratte, JF Dilmanian, FA Park, SJ James, RB AF Vaska, P. Bolotnikov, A. Carini, G. Camarda, G. Pratte, J. -F. Dilmanian, F. A. Park, S. J. James, R. B. BE Yu, B TI Studies of CZT for PET applications SO 2005 IEEE Nuclear Science Symposium Conference Record, Vols 1-5 SE IEEE NUCLEAR SCIENCE SYMPOSIUM - CONFERENCE RECORD LA English DT Proceedings Paper CT Nuclear Science Symposium/Medical Imaging Conference CY OCT 23-29, 2005 CL Fajardo, PR SP IEEE Nucl & Plasma Sci Soc, Brookhaven Natl Lab, CEA Saclay, DOE, CERN, Lawrence Berkeley Natl Lab, Lawrence Livermore Natl Lab, Stanford Linear Accelerator Ctr, Univ Calif Davis, Univ Washington ID PERFORMANCE; DETECTORS; SCANNER AB CdZnTe (CZT) has been investigated by several researchers as a detector material for positron emission tomography (PET) applications. CZT detectors can be manufactured into 1 cm(3) or larger detectors with pixelated anodes, providing high spatial resolution at the 1 mm level or smaller. Indeed the spatial and energy resolution of CZT can be far superior to those of current state-of-the-art PET detectors, most of which are scintillator-based. On the other hand, at 511 keV its timing performance and photopeak detection efficiency are generally inferior, which pose challenges that must be surmounted. In order to obtain sufficient efficiency with a practical number of electronics channels and interconnections in a realistic full-scale system, the focus is on thick detectors (similar to 10. mm). However, the timing becomes more challenging With increasing thickness due to the low charge mobility. We evaluated planar and coplanar grid CZT detectors, as well as position-sensitive pixel-anode detectors to assess methods of improving timing performance. For a 7.5-mm thick coplanar grid detector at 1000 V bias, we obtained a preliminary time resolution vs. BaF2 detector of 21 ns FWHM by fitting the digitally sampled rising edge of the cathode signal. Optimization of the front-end electronics and data-processing methods is expected to further improve these results. We are currently characterizing the performance of a pixel cube detector of similar to 1 cm(3) in size with a single cathode and a 4 x 4 array of anodes with 2.5mm pitch on the opposing side, for which a data acquisition system has been designed and fabricated. C1 Brookhaven Natl Lab, Upton, NY 11973 USA. RP Vaska, P (reprint author), Brookhaven Natl Lab, Upton, NY 11973 USA. NR 9 TC 3 Z9 4 U1 0 U2 2 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1082-3654 BN 0-7803-9221-3 J9 IEEE NUCL SCI CONF R PY 2005 BP 2799 EP 2802 PG 4 WC Instruments & Instrumentation; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Instruments & Instrumentation; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA BFH22 UT WOS:000241851904082 ER PT S AU Krishnamoorthy, S Vaska, P Stoll, S Purschke, M Pratte, JF Woody, CL Schlyer, DJ O'Connor, P AF Krishnamoorthy, S. Vaska, P. Stoll, S. Purschke, M. Pratte, J. -F. Woody, C. L. Schlyer, D. J. O'Connor, P. BE Yu, B TI A prototype anger-type detector for PET using LSO and large-area APDs SO 2005 IEEE Nuclear Science Symposium Conference Record, Vols 1-5 SE IEEE NUCLEAR SCIENCE SYMPOSIUM - CONFERENCE RECORD LA English DT Proceedings Paper CT Nuclear Science Symposium/Medical Imaging Conference CY OCT 23-29, 2005 CL Fajardo, PR SP IEEE Nucl & Plasma Sci Soc, Brookhaven Natl Lab, CEA Saclay, DOE, CERN, Lawrence Berkeley Natl Lab, Lawrence Livermore Natl Lab, Stanford Linear Accelerator Ctr, Univ Calif Davis, Univ Washington ID RESOLUTION; SCANNER; MICROPET; MODULES AB Spatial resolution in positron emission tomography has steadily improved over the years, but remains substantially worse than in other imaging modalities, currently at similar to 2 mm for the most popular commercial tomographs. This is a serious limitation particularly for imaging mice, which have great potential in preclinical PET research because of their compatibility with genetic manipulation. A novel gamma-ray detector design which can achieve high resolution and sensitivity and also facilitates depth of interaction measurement has been developed. It consists of a slab of LSO and arrays of large-area avalanche photodiodes (APDs) on both sides which are used in a light sharing (Anger-type) scheme. A fully instrumented prototype detector has been constructed comprising a 10 mm thick LSO crystal and an array of 7 square APDs (each 11 mm x 11 mm in area) optically coupled to each side. Preliminary measurements carried with a collimated source mounted on a computer controlled X-Y translational stage demonstrate a resolution of similar to 2.5mm FWHM between the center of two APDs. Optimization of electronics noise factors is critical to improving detector performance. C1 Brookhaven Natl Lab, Upton, NY 11973 USA. RP Krishnamoorthy, S (reprint author), Brookhaven Natl Lab, Upton, NY 11973 USA. NR 11 TC 2 Z9 2 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1082-3654 BN 0-7803-9221-3 J9 IEEE NUCL SCI CONF R PY 2005 BP 2845 EP 2848 PG 4 WC Instruments & Instrumentation; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Instruments & Instrumentation; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA BFH22 UT WOS:000241851904091 ER PT S AU Purschke, ML Kandasamy, A O'Connor, P Pratte, JF Schlyer, D Junnakar, S Park, SJ Stoll, SP Vaska, P Woody, CL AF Purschke, M. L. Kandasamy, A. O'Connor, P. Pratte, J. -F. Schlyer, D. Junnakar, S. Park, S-J. Stoll, S. P. Vaska, P. Woody, C. L. BE Yu, B TI The data acquisition system of the RatCAP conscious small animal PET Tomograph SO 2005 IEEE Nuclear Science Symposium Conference Record, Vols 1-5 SE IEEE NUCLEAR SCIENCE SYMPOSIUM - CONFERENCE RECORD LA English DT Proceedings Paper CT Nuclear Science Symposium/Medical Imaging Conference CY OCT 23-29, 2005 CL Fajardo, PR SP IEEE Nucl & Plasma Sci Soc, Brookhaven Natl Lab, CEA Saclay, DOE, CERN, Lawrence Berkeley Natl Lab, Lawrence Livermore Natl Lab, Stanford Linear Accelerator Ctr, Univ Calif Davis, Univ Washington AB We describe the progress made data acquisition system for the RatCAP Tomograph [1], [2]. RatCAP is a small, head-mounted PET detector designed to image the brain of an awake rat. At its core, the tomograph consists of a number of LSO crystals read out with an array of APDs. The data are collected through a custom-designed ASIC, along with a custom VME board. We describe the design, implementation, and performance of a versatile VME-based data acquisition system which will be used to read out the VME board, as well as other off-the-shelf data acquisition electronics. C1 Brookhaven Natl Lab, Upton, NY 11973 USA. RP Purschke, ML (reprint author), Brookhaven Natl Lab, Upton, NY 11973 USA. NR 4 TC 0 Z9 0 U1 2 U2 2 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1082-3654 BN 0-7803-9221-3 J9 IEEE NUCL SCI CONF R PY 2005 BP 2942 EP 2943 PG 2 WC Instruments & Instrumentation; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Instruments & Instrumentation; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA BFH22 UT WOS:000241851904114 ER PT S AU Proffitt, J Hammond, W Majewski, S Popov, V Raylman, RR Weisenberger, AG Wojcik, R AF Proffitt, J. Hammond, W. Majewski, S. Popov, V. Raylman, R. R. Weisenberger, A. G. Wojcik, R. BE Yu, B TI A flexible high-rate USB2 data acquisition system for PET and SPECT imaging SO 2005 IEEE Nuclear Science Symposium Conference Record, Vols 1-5 SE IEEE NUCLEAR SCIENCE SYMPOSIUM - CONFERENCE RECORD LA English DT Proceedings Paper CT Nuclear Science Symposium/Medical Imaging Conference CY OCT 23-29, 2005 CL Fajardo, PR SP IEEE Nucl & Plasma Sci Soc, Brookhaven Natl Lab, CEA Saclay, DOE, CERN, Lawrence Berkeley Natl Lab, Lawrence Livermore Natl Lab, Stanford Linear Accelerator Ctr, Univ Calif Davis, Univ Washington AB A new flexible data acquisition system has been developed to instrument gamma-ray imaging detectors designed by the Jefferson Lab Detector and Imaging Group. Hardware consists of 16-channel data acquisition modules installed on USB2 carrier boards. Carriers have been designed to accept one, two, and four modules. Application trigger rate and channel density determines the number of acquisition boards and readout computers used. Each channel has an independent trigger, gated integrator and a 2.5MHz 12-bit ADC. Each module has an FPGA foe analog control and signal processing. Processing includes a 5ns 40-bit trigger time stamp and programmable triggering, gating, ADC timing, offset and gain correction, charge and pulse-width discrimination, sparsification, event counting, and event assembly. The carrier manages global triggering and transfers module data to a USB buffer. High-granularity time-stamped triggering is suitable for modular detectors. Time stamped events permit dynamic studies, complex offline event assembly, and high-rate distributed data acquisition. A sustained USB data rate of 20Mbytes/s, a sustained trigger rate of 300 kHz for 32 channels, and a peak trigger rate of 2.5MHz to FIFO memory were achieved. Different trigger, gating, processing, and event assembly techniques were explored. Target applications include > 100 kHz coincidence rate PET detectors, dynamic SPECT detectors, miniature and portable gamma detectors for small-animal and clinical use. C1 Thomas Jefferson Natl Accelerator Facil, Newport News, VA USA. RP Proffitt, J (reprint author), Thomas Jefferson Natl Accelerator Facil, Newport News, VA USA. NR 2 TC 12 Z9 12 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1082-3654 BN 0-7803-9221-3 J9 IEEE NUCL SCI CONF R PY 2005 BP 2971 EP 2975 PG 5 WC Instruments & Instrumentation; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Instruments & Instrumentation; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA BFH22 UT WOS:000241851904121 ER PT S AU Vaska, P Woody, CL Schlyer, DJ Radeka, V O'Connor, P Pratte, JF Shokouhi, S Stoll, SP Junnarkar, SS Purschke, M Park, SJ Southekal, S Dzhordzhadze, V Schiffer, W Neill, J Murphy, M Aubele, T Kristiansen, R Villanueva, A Boose, S Kandasamy, A Yu, B Kriplani, A Krishnamoorthy, S Lecomte, R Fontaine, R AF Vaska, P. Woody, C. L. Schlyer, D. J. Radeka, V. O'Connor, P. Pratte, J. -F. Shokouhi, S. Stoll, S. P. Junnarkar, S. S. Purschke, M. Park, S. -J. Southekal, S. Dzhordzhadze, V. Schiffer, W. Neill, J. Murphy, M. Aubele, T. Kristiansen, R. Villanueva, A. Boose, S. Kandasamy, A. Yu, B. Kriplani, A. Krishnamoorthy, S. Lecomte, R. Fontaine, R. BE Yu, B TI Initial performance of the RatCAP, a PET camera for conscious rat brain imaging SO 2005 IEEE Nuclear Science Symposium Conference Record, Vols 1-5 SE IEEE NUCLEAR SCIENCE SYMPOSIUM - CONFERENCE RECORD LA English DT Proceedings Paper CT Nuclear Science Symposium/Medical Imaging Conference CY OCT 23-29, 2005 CL Fajardo, PR SP IEEE Nucl & Plasma Sci Soc, Brookhaven Natl Lab, CEA Saclay, DOE, CERN, Lawrence Berkeley Natl Lab, Lawrence Livermore Natl Lab, Stanford Linear Accelerator Ctr, Univ Calif Davis, Univ Washington ID HEAD-MOUNTED PET; MICROPET; SCANNER; TOMOGRAPHS AB The first fully functional prototype of the RatCAP (Rat Conscious Animal PET) scanner has been constructed and preliminary evaluations have been performed. RatCAP is a miniature, high performance PET,scanner designed specifically image the brain of a rat while directly attached to its head. The goal is to eliminate the need for anesthesia which can confound quantitative brain studies and prevent simultaneous correlations of neurochemistry and behavior. RatCAP is a fully 3D tomograph with a transaxial (axial) field-of-view of 38 (18) mm, outside diameter 72 mm, and weight < 200 g which is supported by a small tether. A total of 384 LSO crystals are divided among 12 independent detector blocks, each of which contains an avalanche photodiode (APD) photosensor array and a custom-designed ASIC for highly integrated front-end processing. A custom FPGA-based time-stamp module has been designed and implemented, achieving a preliminary system resolution of 13.9 ns FWHM. With a point source in the FOV center, spatial resolution is 2.1 mm FWHM, energy resolution averages 23% FWHM, and sensitivity is 0.7% at an average threshold of 150 keV. Novel offline data processing algorithms have been developed including methods for time and energy calibrations, corrections for physical effects, and a highly accurate iterative image reconstruction. Initial phantom and rat brain images have been obtained. C1 Brookhaven Natl Lab, Upton, NY 11973 USA. RP Vaska, P (reprint author), Brookhaven Natl Lab, Upton, NY 11973 USA. OI LECOMTE, Roger/0000-0002-8541-0783 NR 13 TC 0 Z9 0 U1 2 U2 2 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1082-3654 BN 0-7803-9221-3 J9 IEEE NUCL SCI CONF R PY 2005 BP 3040 EP 3044 PG 5 WC Instruments & Instrumentation; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Instruments & Instrumentation; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA BFH22 UT WOS:000241851904137 ER PT B AU Novokhatski, A AF Novokhatski, A GP IEEE TI HOM effects in vacuum chamber with short bunches SO 2005 IEEE PARTICLE ACCELERATOR CONFERENCE (PAC), VOLS 1-4 SE IEEE Particle Accelerator Conference LA English DT Proceedings Paper CT 21st Particle Accelerator Conference (PAC) CY MAY 16-20, 2005 CL Knoxville, TN SP IEEE AB High luminosity in electron-positron factories requires high currents of very short bunches. SLAC PEP-II and KEKB B-factories are progressively increasing currents gaining more and more luminosity [1-2]. Simultaneously the interaction of high currents and vacuum chamber elements becomes more important for operation of the rings. High Order Modes excited by short intense bunches are propagating along the vacuum chamber, penetrating and dissipating inside vital vacuum elements, like shielded bellows, vacuum valves and vacuum pump. As a result these elements get large temperature rise or temperature oscillations. Often HOM heating has a resonance character. HOM heating of vacuum pumps leads to increasing of the vacuum pressure. High frequency modes "check" the quality of vacuum chamber: they detect small gaps, weak RF screens or feed-through. Smooth tapers and collimators become the source of HOM production. We will discuss the physical nature of these exciting HOM effects. C1 Stanford Univ, SLAC, Stanford, CA USA. RP Novokhatski, A (reprint author), Stanford Univ, SLAC, Stanford, CA USA. EM novo@slac.stanford.edu NR 4 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-8859-3 J9 IEEE PART ACC CONF PY 2005 BP 11 EP 15 PG 5 WC Instruments & Instrumentation; Physics, Particles & Fields SC Instruments & Instrumentation; Physics GA BDV94 UT WOS:000235745200003 ER PT B AU Rimmer, RA Benesch, J Preble, J Reece, C AF Rimmer, RA Benesch, J Preble, J Reece, C GP IEEE TI SRF performance of CEBAF after thermal cycle to ambient temperature SO 2005 IEEE PARTICLE ACCELERATOR CONFERENCE (PAC), VOLS 1-4 SE IEEE Particle Accelerator Conference LA English DT Proceedings Paper CT 21st Particle Accelerator Conference (PAC) CY MAY 16-20, 2005 CL Knoxville, TN SP IEEE AB In September 2003, in the wake of Hurricane Isabel, JLab was without power for four days after a tree fell on the main power lines feeding the site. This was long enough to lose insulating vacuum in the cryomodules and cryogenic systems resulting in the whole accelerator warming up and the total loss of the liquid helium inventory. This thermal cycle stressed many of the cryomodule components causing several cavities to become inoperable due to helium to vacuum leaks. At the same time the thermal cycle released years of adsorbed gas from the cold surfaces. Over the next days and weeks this gas was pumped away, the insulating vacuum was restored and the machine was cooled back down and recommissioned. In a testament to the robustness of SRF technology, only a small loss in energy capability was apparent, although individual cavities had quite different field-emission characteristics compared to before the event. In Summer 2004 a section of the machine was again cycled to room temperature during the long maintenance shutdown. We report on the overall SRF performance of the machine after these major disturbances and on efforts to characterize and optimize the new behavior for high-energy running. C1 JLab, Newport News, VA 23606 USA. RP Rimmer, RA (reprint author), JLab, Newport News, VA 23606 USA. NR 3 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-8859-3 J9 IEEE PART ACC CONF PY 2005 BP 28 EP 30 PG 3 WC Instruments & Instrumentation; Physics, Particles & Fields SC Instruments & Instrumentation; Physics GA BDV94 UT WOS:000235745200007 ER PT B AU Reijonen, J Lawrence, EO AF Reijonen, J Lawrence, EO GP IEEE TI Compact neutron generators for medical, home land security, and planetary exploration SO 2005 IEEE PARTICLE ACCELERATOR CONFERENCE (PAC), VOLS 1-4 SE IEEE Particle Accelerator Conference LA English DT Proceedings Paper CT 21st Particle Accelerator Conference (PAC) CY MAY 16-20, 2005 CL Knoxville, TN SP IEEE ID ION-SOURCE; NUCLEAR TECHNIQUES; EXTRACTION; SIMULATION; SYSTEM AB The Plasma and Ion Source Technology Group at Lawrence Berkeley National Laboratory has developed various types of advanced D-D (neutron energy 2.5 MeV), D-T (14 MeV) and T-T (0 - 9 MeV) neutron generators for wide range of applications. These applications include medical (Boron Neutron Capture Therapy), homeland security (Prompt Gamma Activation Analysis, Fast Neutron Activation Analysis and Pulsed Fast Neutron Transmission Spectroscopy) and planetary exploration with a sub-surface material characterization on Mars. These neutron generators utilize RF induction discharge to ionize the deuterium/tritium gas. This discharge method provides high plasma density for high output current, high atomic species from molecular gases, long life operation and versatility for various discharge chamber geometries. Four main neutron generator developments are discussed here: high neutron output co-axial neutron generator for BNCT applications, point neutron generator for security applications, compact and sub-compact axial neutron generator for elemental analysis applications. Current status of the neutron generator development with experimental data will be presented. C1 EO Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. RP Reijonen, J (reprint author), EO Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. NR 23 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-8859-3 J9 IEEE PART ACC CONF PY 2005 BP 34 EP 38 PG 5 WC Instruments & Instrumentation; Physics, Particles & Fields SC Instruments & Instrumentation; Physics GA BDV94 UT WOS:000235745200009 ER PT B AU Li, DR AF Li, DR CA US Neutrino Factory GP IEEE TI Status of neutrion factory design and R&D SO 2005 IEEE PARTICLE ACCELERATOR CONFERENCE (PAC), VOLS 1-4 SE IEEE Particle Accelerator Conference LA English DT Proceedings Paper CT 21st Particle Accelerator Conference (PAC) CY MAY 16-20, 2005 CL Knoxville, TN SP IEEE AB Neutrino physics has become increasingly interesting to the high-energy physics community, as it may provide clues to new physics beyond the standard model. The physics potential of a Neutrino Factory-a facility to produce high-energy, high-intensity, high-brightness neutrino beams from decays of muons stored in a muon storage ring-is thus very high. There has been a global R&D effort aimed at a Neutrino Factory design that meets the physics requirements and addresses the key technologies, such as targetry, muon ionization cooling and acceleration. Tremendous progress has been made in the past few years in many aspects of accelerator technology. In this paper, we will review recent worldwide progress toward a cost-effective Neutrino Factory design, with emphasis on the associated R&D programs under the auspices of the U.S. Neutrino Factory and Muon Collider Collaboration [1]. C1 Lawrence Berkeley Lab, Ctr Beam Phys, US Neutrino Fact & Muon Collider Collaborat, Berkeley, CA 94720 USA. RP Li, DR (reprint author), Lawrence Berkeley Lab, Ctr Beam Phys, US Neutrino Fact & Muon Collider Collaborat, Berkeley, CA 94720 USA. EM DLi@lbl.gov NR 4 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-8859-3 J9 IEEE PART ACC CONF PY 2005 BP 61 EP 65 PG 5 WC Instruments & Instrumentation; Physics, Particles & Fields SC Instruments & Instrumentation; Physics GA BDV94 UT WOS:000235745200016 ER PT B AU Lessner, ES Ostroumov, PN AF Lessner, ES Ostroumov, PN GP IEEE TI Reliability and availability studies in the RIA driver linac SO 2005 IEEE PARTICLE ACCELERATOR CONFERENCE (PAC), VOLS 1-4 SE IEEE Particle Accelerator Conference LA English DT Proceedings Paper CT 21st Particle Accelerator Conference (PAC) CY MAY 16-20, 2005 CL Knoxville, TN SP IEEE AB The Rare Isotope Accelerator (RIA) facility will include various complex systems and must provide radioactive beams to many users simultaneously. The availability of radioactive beams for most experiments at the fully-commissioned facility should be as high as possible within design cost limitations. To make a realistic estimate of the achievable reliability a detailed analysis is required. The RIA driver linac is a complex machine containing a large number of superconducting (SC) resonators and capable of accelerating multiple-charge-state beams [1]. At the pre-CDR stage of the design it is essential to identify critical facility subsystem failures that can prevent the driver linac from operating. The reliability and availability of the driver linac were studied using expert information and data from operating machines such as ATLAS, APS, JLab, and LANL. Availability studies are performed with a Monte-Carlo simulation code previously applied to availability assessments of the NLC facility [2] and the results used to identify subsystem failures that most affect the availability and reliability of the RIA driver, and guide design iterations and component specifications to address identified problems. C1 Argonne Natl Lab, Argonne, IL 60439 USA. RP Lessner, ES (reprint author), Argonne Natl Lab, 9700 S Cass Ave, Argonne, IL 60439 USA. EM esl@phy.anl.gov NR 2 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-8859-3 J9 IEEE PART ACC CONF PY 2005 BP 74 EP 76 PG 3 WC Instruments & Instrumentation; Physics, Particles & Fields SC Instruments & Instrumentation; Physics GA BDV94 UT WOS:000235745200019 ER PT B AU Anderson, SG Brown, WJ Gibson, DJ Hartemann, FV Jacob, JS Tremaine, AM Lim, JK Frigola, P Musumeci, P Rosenzweig, JB Travish, G AF Anderson, SG Brown, WJ Gibson, DJ Hartemann, FV Jacob, JS Tremaine, AM Lim, JK Frigola, P Musumeci, P Rosenzweig, JB Travish, G GP IEEE TI Ultra-high density electron beams for beam radiation and beam plasma interaction SO 2005 IEEE PARTICLE ACCELERATOR CONFERENCE (PAC), VOLS 1-4 SE IEEE Particle Accelerator Conference LA English DT Proceedings Paper CT 21st Particle Accelerator Conference (PAC) CY MAY 16-20, 2005 CL Knoxville, TN SP IEEE ID MULTIPOLE MAGNETS; SCATTERING AB Current and future applications of high brightness electron beams, which include advanced accelerators such as the plasma wake-field accelerator (PWFA) and beam-radiation interactions such as inverse-Compton scattering (ICS), require both transverse and longitudinal beam sizes on the order of tens of microns. Ultra-high density beams may be produced at moderate energy (50 MeV) by compression and subsequent strong focusing of low emittance, photoinjector sources. We describe the implementation of this method used at the PLEIADES ICS x-ray source in which the photoinjector-generated beam has been compressed to 300 fsec duration using the velocity bunching technique and focused to 20 mu m rms size using an extremely high gradient, permanent magnet quadrupole (PMQ) focusing system. C1 LLNL, Livermore, CA 94550 USA. RP Anderson, SG (reprint author), LLNL, Livermore, CA 94550 USA. NR 23 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-8859-3 J9 IEEE PART ACC CONF PY 2005 BP 82 EP 85 PG 4 WC Instruments & Instrumentation; Physics, Particles & Fields SC Instruments & Instrumentation; Physics GA BDV94 UT WOS:000235745200021 ER PT B AU Bhat, CM AF Bhat, CM GP IEEE TI ISO-adiabatic merging of pbar stacks in the Fermilab Recycler SO 2005 IEEE PARTICLE ACCELERATOR CONFERENCE (PAC), VOLS 1-4 SE IEEE Particle Accelerator Conference LA English DT Proceedings Paper CT 21st Particle Accelerator Conference (PAC) CY MAY 16-20, 2005 CL Knoxville, TN SP IEEE ID RING AB Considerable longitudinal emittance (LE) dilution is seen during merging of two stacks of pbars in the Fermilab Recycler. The emittance dilution results from the sequence of RF manipulations used for merging. Here I present a new scheme for merging two stacks adiabatically. This involves energy matching of the two stacks before merging. An analytical expression is derived for energy matching condition. The scheme is illustrated with multi-particle beam dynamics simulations and beam measurements. The beam experiments have shown that one can preserve the emittance to better than 15%. C1 Fermilab Natl Accelerator Lab, Batavia, IL 60510 USA. RP Bhat, CM (reprint author), Fermilab Natl Accelerator Lab, POB 500, Batavia, IL 60510 USA. EM cbhat@fnal.gov NR 14 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-8859-3 J9 IEEE PART ACC CONF PY 2005 BP 112 EP 114 PG 3 WC Instruments & Instrumentation; Physics, Particles & Fields SC Instruments & Instrumentation; Physics GA BDV94 UT WOS:000235745200030 ER PT B AU Chou, W Wildman, D Takagi, A Zheng, H AF Chou, W Wildman, D Takagi, A Zheng, H GP IEEE TI Barrier RF system and applications in Main Injector SO 2005 IEEE PARTICLE ACCELERATOR CONFERENCE (PAC), VOLS 1-4 SE IEEE Particle Accelerator Conference LA English DT Proceedings Paper CT 21st Particle Accelerator Conference (PAC) CY MAY 16-20, 2005 CL Knoxville, TN SP IEEE ID BEAM AB A novel broadband RF system - the barrier RF - has been designed, fabricated and installed in the Fermilab Main Injector (MI). It uses nanocrystal magnetic alloy called Finemet and high voltage fast MOSFET switches. The system delivers +/- 10 kV square pulses at 90 kHz. It can stack two proton batches injected from the Booster and squeeze them into the size of one so that the bunch intensity is increased. The high intensity beams have been successfully accelerated to 120 GeV with small losses. The problem of large longitudinal emittance growth is under investigation. A second system will be installed during the fall shutdown and be tested for the so-called fast stacking scheme to continuously stack up to 12 Booster batches in the MI. This system is also used for cleaning up the leaking-out dc beams from slip stacking to reduce beam loss. This work is part of the US-Japan collaborative agreement. C1 Fermilab Natl Accelerator Lab, Batavia, IL 60510 USA. RP Chou, W (reprint author), Fermilab Natl Accelerator Lab, POB 500, Batavia, IL 60510 USA. EM chou@fnal.gov NR 8 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-8859-3 J9 IEEE PART ACC CONF PY 2005 BP 118 EP 120 PG 3 WC Instruments & Instrumentation; Physics, Particles & Fields SC Instruments & Instrumentation; Physics GA BDV94 UT WOS:000235745200032 ER PT B AU Chou, W Bryant, H Drozhdin, A Hill, C Kostin, M Macek, R Ostiguy, JF Rees, GH Tang, Z Yoon, P AF Chou, W Bryant, H Drozhdin, A Hill, C Kostin, M Macek, R Ostiguy, JF Rees, GH Tang, Z Yoon, P GP IEEE TI 8 GeVH(-) ions: Transport and injection SO 2005 IEEE PARTICLE ACCELERATOR CONFERENCE (PAC), VOLS 1-4 SE IEEE Particle Accelerator Conference LA English DT Proceedings Paper CT 21st Particle Accelerator Conference (PAC) CY MAY 16-20, 2005 CL Knoxville, TN SP IEEE ID RELATIVISTIC H-IONS; CROSS-SECTIONS; THIN FOILS; HYDROGEN; TRANSMISSION; ATOMS AB Fermilab is working on the design of all 8 GeV superconducting RF H(-) linac called the Proton Driver. The energy of H(-) beam will be an order of magnitude higher than the existing ones. This brings up a number of technical challenges to transport and injection of H(-) ions. This paper will focus on the subjects of stripping losses (including stripping by black-body radiation, field and residual gas) and carbon foil stripping efficiency, along with a brief discussion on other issues such as Stark states lifetime of hydrogen atoms, single and multiple Coulomb scattering, foil heating and stress, radiation activation, collimation and jitter correction, etc. C1 Fermilab Natl Accelerator Lab, Batavia, IL 60510 USA. RP Chou, W (reprint author), Fermilab Natl Accelerator Lab, POB 500, Batavia, IL 60510 USA. EM chou@fnal.gov NR 16 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-8859-3 J9 IEEE PART ACC CONF PY 2005 BP 121 EP 123 PG 3 WC Instruments & Instrumentation; Physics, Particles & Fields SC Instruments & Instrumentation; Physics GA BDV94 UT WOS:000235745200033 ER PT B AU Wu, V Bhat, CM Chase, BE Dey, JE Meisner, KG AF Wu, V Bhat, CM Chase, BE Dey, JE Meisner, KG GP IEEE TI Experimental test of a new antiproton acceleration scheme in the Fermilab Main Injector SO 2005 IEEE PARTICLE ACCELERATOR CONFERENCE (PAC), VOLS 1-4 SE IEEE Particle Accelerator Conference LA English DT Proceedings Paper CT 21st Particle Accelerator Conference (PAC) CY MAY 16-20, 2005 CL Knoxville, TN SP IEEE AB In an effort to provide higher intensity and lower emittance antiproton beam to the Tevatron collider for high luminosity operation, a new Main Injector (MI) antiproton acceleration scheme has been developed [1-4]. In this scheme, beam is accelerated from 8 to 27 GeV using the 2.5 MHz rf system and from 27 to 150 GeV using the 53 MHz rf system. This paper reports the experimental results of beam study. Simulation results are reported in a different PAC'05 paper [5]. Experiments are conducted with proton beam from the Booster. Acceleration efficiency, emittance growth and beam harmonic transfer between 2.5 MHz (h=28) and 53 MHz (h=588) buckets have been studied. Beam study shows that one can achieve an overall acceleration efficiency of about 100%, longitudinal emittance growth less than 20% and negligible transverse emittance growth. C1 Fermilab Natl Accelerator Lab, Batavia, IL 60510 USA. RP Wu, V (reprint author), Fermilab Natl Accelerator Lab, POB 500, Batavia, IL 60510 USA. EM vincentw@fnal.gov NR 9 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-8859-3 J9 IEEE PART ACC CONF PY 2005 BP 124 EP 126 PG 3 WC Instruments & Instrumentation; Physics, Particles & Fields SC Instruments & Instrumentation; Physics GA BDV94 UT WOS:000235745200034 ER PT B AU Xiao, MQ AF Xiao, MQ GP IEEE TI Calculation of the orbit length change of the Recycler due to Main Injector ramp SO 2005 IEEE PARTICLE ACCELERATOR CONFERENCE (PAC), VOLS 1-4 SE IEEE Particle Accelerator Conference LA English DT Proceedings Paper CT 21st Particle Accelerator Conference (PAC) CY MAY 16-20, 2005 CL Knoxville, TN SP IEEE AB Orbit length of a beam in the Recycler changes during the Main Injector ramps. Unknown kicks from the effects generated by a stray field distribute around the ring. Particularly we observed additional effects from the MI lambertsons and the C-magnets during their ramps for a beam transfer. To estimate the changes, simulated virtual kicks are created in the Recycler lattice. The difference of the orbit lengths is calculated by comparing the horizontal closed orbit of the beam with a reference orbit. Calculation results show that strong effect came from the buses. In this report, we describe the calculation methods. Also presented are the analysis including the calculation of the orbit length changes and the strength of the simulated kicks before and after we shield the buses. C1 Fermilab Natl Accelerator Lab, Batavia, IL 60510 USA. RP Xiao, MQ (reprint author), Fermilab Natl Accelerator Lab, POB 500, Batavia, IL 60510 USA. EM meiqin@fnal.gov NR 2 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-8859-3 J9 IEEE PART ACC CONF PY 2005 BP 127 EP 129 PG 3 WC Instruments & Instrumentation; Physics, Particles & Fields SC Instruments & Instrumentation; Physics GA BDV94 UT WOS:000235745200035 ER PT B AU Huang, H Ahrens, LA Bai, M Brown, K Courant, ED Gardner, C Glenn, JW Gupta, RC Luccio, AU MacKay, WW Ptitsyn, V Roser, T Tepikian, S Tsoupas, N Willen, E Zelenski, A Zeno, K Okamura, M Takano, J Lin, F AF Huang, H Ahrens, LA Bai, M Brown, K Courant, ED Gardner, C Glenn, JW Gupta, RC Luccio, AU MacKay, WW Ptitsyn, V Roser, T Tepikian, S Tsoupas, N Willen, E Zelenski, A Zeno, K Okamura, M Takano, J Lin, F GP IEEE TI Acceleration of polarized protons in the AGS with two helical partial snakes SO 2005 IEEE PARTICLE ACCELERATOR CONFERENCE (PAC), VOLS 1-4 SE IEEE Particle Accelerator Conference LA English DT Proceedings Paper CT 21st Particle Accelerator Conference (PAC) CY MAY 16-20, 2005 CL Knoxville, TN SP IEEE AB The RHIC spin program requires 2x10(11) proton/bunch with 70% polarization. As the injector to RHIC, AGS is the bottleneck for preserving polarization: there is no space for a full snake to overcome numerous depolarizing resonances. An ac dipole and a partial snake have been used to preserve beam polarization in the past few years. Two helical snakes have been built and installed in the AGS. With careful setup of optics at injection and along the ramp, this combination can eliminate all depolarizing resonances encountered during acceleration. This paper presents the setup and preliminary results. C1 BNL, Upton, NY USA. RP Huang, H (reprint author), BNL, Upton, NY USA. NR 5 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-8859-3 J9 IEEE PART ACC CONF PY 2005 BP 130 EP 132 PG 3 WC Instruments & Instrumentation; Physics, Particles & Fields SC Instruments & Instrumentation; Physics GA BDV94 UT WOS:000235745200036 ER PT B AU Hu, M Nagaitsev, S AF Hu, M Nagaitsev, S GP IEEE TI Observation of longitudinal diffusion and cooling due to intrabeam scattering at the Fermilab Recycler Ring SO 2005 IEEE PARTICLE ACCELERATOR CONFERENCE (PAC), VOLS 1-4 SE IEEE Particle Accelerator Conference LA English DT Proceedings Paper CT 21st Particle Accelerator Conference (PAC) CY MAY 16-20, 2005 CL Knoxville, TN SP IEEE AB The Fermilab Recycler Ring is a high-vacuum fixed energy antiproton storage ring with both stochastic (at present) and the future electron cooling systems. In this paper the technique for diffusion rate measurement, beam parameters and the analysis of data are presented, as well as the effect of intrabeam scattering on the operational considerations for the storage and cooling of the antiproton beam in the Recycler. C1 Fermilab Natl Accelerator Lab, Batavia, IL 60510 USA. RP Hu, M (reprint author), Fermilab Natl Accelerator Lab, POB 500, Batavia, IL 60510 USA. EM martinhu@fnal.gov NR 3 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-8859-3 J9 IEEE PART ACC CONF PY 2005 BP 136 EP 138 PG 3 WC Instruments & Instrumentation; Physics, Particles & Fields SC Instruments & Instrumentation; Physics GA BDV94 UT WOS:000235745200038 ER PT B AU Yang, X Ankenbrandt, CM Pellico, WA Lackey, J Padilla, R AF Yang, X Ankenbrandt, CM Pellico, WA Lackey, J Padilla, R GP IEEE TI Booster 6-GeV study SO 2005 IEEE PARTICLE ACCELERATOR CONFERENCE (PAC), VOLS 1-4 SE IEEE Particle Accelerator Conference LA English DT Proceedings Paper CT 21st Particle Accelerator Conference (PAC) CY MAY 16-20, 2005 CL Knoxville, TN SP IEEE AB A wider aperture, which has been obtained along the Booster beam line recently, brings the opportunity to run beams with the intensity higher than ever before. Sooner or later, the available RF accelerating voltage will become a new limit for the beam intensity. Extra accelerating voltages can be achieved either by increasing the RFSUM or by reducing the accelerating rate via a slower acceleration, and this motivates the 6-GeV study. C1 Fermilab Natl Accelerator Lab, Batavia, IL 60510 USA. RP Yang, X (reprint author), Fermilab Natl Accelerator Lab, POB 500, Batavia, IL 60510 USA. NR 7 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-8859-3 J9 IEEE PART ACC CONF PY 2005 BP 139 EP 141 PG 3 WC Instruments & Instrumentation; Physics, Particles & Fields SC Instruments & Instrumentation; Physics GA BDV94 UT WOS:000235745200039 ER PT B AU Cousineau, S Danilov, V Henderson, S Holmes, J Plum, M AF Cousineau, S Danilov, V Henderson, S Holmes, J Plum, M GP IEEE TI Studies performed in preparation for the Spallation Neutron Source accumulator ring commissioning SO 2005 IEEE PARTICLE ACCELERATOR CONFERENCE (PAC), VOLS 1-4 SE IEEE Particle Accelerator Conference LA English DT Proceedings Paper CT 21st Particle Accelerator Conference (PAC) CY MAY 16-20, 2005 CL Knoxville, TN SP IEEE AB The Spallation Neutron Source accumulator ring will compress 1.5x10(14), 1 GeV protons from a 1 ms bunch train to a single 695 ns proton bunch for use in neutron spallation. Due to the high beam power, unprecedented control of beam loss will be required in order to control radiation and allow for hands-on maintenance in most areas of the ring. A number of detailed investigations have been performed to understand the primary sources of beam loss and to predict and mitigate problems associated with radiation hot spots in the ring. The ORBIT particle tracking code is used to perform realistic simulations of the beam accumulation in the ring, including detailed modeling of the injection system, transport through the measured magnet fields including higher order multipoles, and beam loss and collimation. In this paper we present the results of a number of studies performed in preparation for the 2006 commissioning of the accumulator ring. C1 Oak Ridge Natl Lab, SNS, Oak Ridge, TN 37830 USA. RP Cousineau, S (reprint author), Oak Ridge Natl Lab, SNS, Oak Ridge, TN 37830 USA. NR 2 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-8859-3 J9 IEEE PART ACC CONF PY 2005 BP 154 EP 156 PG 3 WC Instruments & Instrumentation; Physics, Particles & Fields SC Instruments & Instrumentation; Physics GA BDV94 UT WOS:000235745200044 ER PT B AU Ahrens, L Alessi, J Benjamin, J Blaskiewicz, M Brennan, JM Brown, KA Carlson, C DeLong, J Gardner, CJ Glenn, JW Hayes, T MacKay, WW Marr, G Morris, J Roser, T Severino, F Smith, KS Steski, D Tsoupas, N Zaltsman, A Zeno, K AF Ahrens, L Alessi, J Benjamin, J Blaskiewicz, M Brennan, JM Brown, KA Carlson, C DeLong, J Gardner, CJ Glenn, JW Hayes, T MacKay, WW Marr, G Morris, J Roser, T Severino, F Smith, KS Steski, D Tsoupas, N Zaltsman, A Zeno, K GP IEEE TI Setup and performance of the RHIC injector accelerators for the 2005 run with copper ions SO 2005 IEEE PARTICLE ACCELERATOR CONFERENCE (PAC), VOLS 1-4 SE IEEE Particle Accelerator Conference LA English DT Proceedings Paper CT 21st Particle Accelerator Conference (PAC) CY MAY 16-20, 2005 CL Knoxville, TN SP IEEE AB Copper ions for the 2005 run [1] of the Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory (BNL) are accelerated in the Tandem, Booster and AGS prior to injection into RHIC. The setup and performance of these accelerators with copper are reviewed in this paper. C1 Brookhaven Natl Lab, Upton, NY 11973 USA. RP Ahrens, L (reprint author), Brookhaven Natl Lab, Upton, NY 11973 USA. EM cgardner@bnl.gov NR 8 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-8859-3 J9 IEEE PART ACC CONF PY 2005 BP 169 EP 171 PG 3 WC Instruments & Instrumentation; Physics, Particles & Fields SC Instruments & Instrumentation; Physics GA BDV94 UT WOS:000235745200049 ER PT B AU Mallory, ML Ball, JB Dowling, DT Hudson, ED Lord, RS Tatum, BA AF Mallory, ML Ball, JB Dowling, DT Hudson, ED Lord, RS Tatum, BA GP IEEE TI ORIC beam energy increase SO 2005 IEEE PARTICLE ACCELERATOR CONFERENCE (PAC), VOLS 1-4 SE IEEE Particle Accelerator Conference LA English DT Proceedings Paper CT 21st Particle Accelerator Conference (PAC) CY MAY 16-20, 2005 CL Knoxville, TN SP IEEE ID CYCLOTRON AB The detection of and solution to a beam interference problem in the Oak Ridge Isochronous Cyclotron (ORIC) extraction system has yielded a 20% increase in the proton beam energy. The beam from ORIC was designed to be extracted before the v(r) = 1 resonance. Most cyclotrons extract after the v(r) = 1 resonance, thus getting more usage of the magnetic field for energy acceleration. Attempts to increase the ORIC extraction radius over the past 40 years have failed. We determined that the electrostatic deflector septum in ORIC interferes with the last accelerated orbit, with the highest extraction efficiency being obtained near the maximum v(r). This v(r) provides a rotation in the betatron oscillation amplitude that is equal to the same length as the electrostatic septum thus allowing the beam to jump over an interference problem with the septum. With a thinned septum we were able to tune the beam to the v(r) = 1 resonance and achieve a 20% increase in beam energy. However, the method of extraction with v(r) > 1 may be useful for very high field cyclotrons since it provides greater clearance at extraction than that obtained from dee voltage gain, thus allowing the possibility of utilizing a magnetic extractor. C1 ORNL, Oak Ridge, TN 37831 USA. RP Mallory, ML (reprint author), ORNL, Oak Ridge, TN 37831 USA. NR 8 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-8859-3 J9 IEEE PART ACC CONF PY 2005 BP 172 EP 174 PG 3 WC Instruments & Instrumentation; Physics, Particles & Fields SC Instruments & Instrumentation; Physics GA BDV94 UT WOS:000235745200050 ER PT B AU Dodson, GW Williams, TL AF Dodson, GW Williams, TL GP IEEE TI Operational availability of the SNS during beam commissioning SO 2005 IEEE PARTICLE ACCELERATOR CONFERENCE (PAC), VOLS 1-4 SE IEEE Particle Accelerator Conference LA English DT Proceedings Paper CT 21st Particle Accelerator Conference (PAC) CY MAY 16-20, 2005 CL Knoxville, TN SP IEEE AB The Spallation Neutron Source accelerator systems will deliver a 1 GeV, 1.44 MW proton beam to a mercury target for neutron production. The beam commissioning of the accelerator systems is taking place in modules, as components are installed and tested. To date there have been four beam commissioning runs, the H- injector, Drift Tube Linac Tank 1, Drift Tube Linac Tanks 1-3 and Drift Tube Linac Tanks 4-6 plus CCL modules 1-3. Among the critical performance goals have been achieved are, demonstration of design 38 mA beam peak current, 1 msec long beam pulse, and 1 mA average beam. Results of accelerator availability during beam commissioning program are presented. C1 Oak Ridge Natl Lab, SNS Project, Oak Ridge, TN 37830 USA. RP Dodson, GW (reprint author), Oak Ridge Natl Lab, SNS Project, Oak Ridge, TN 37830 USA. NR 4 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-8859-3 J9 IEEE PART ACC CONF PY 2005 BP 175 EP 177 PG 3 WC Instruments & Instrumentation; Physics, Particles & Fields SC Instruments & Instrumentation; Physics GA BDV94 UT WOS:000235745200051 ER PT B AU Raparia, D Alessi, J Ruggiero, A Weng, WT AF Raparia, D Alessi, J Ruggiero, A Weng, WT GP IEEE TI Injector linac for the BNL super neutrino beam project SO 2005 IEEE PARTICLE ACCELERATOR CONFERENCE (PAC), VOLS 1-4 SE IEEE Particle Accelerator Conference LA English DT Proceedings Paper CT 21st Particle Accelerator Conference (PAC) CY MAY 16-20, 2005 CL Knoxville, TN SP IEEE AB BNL plans to upgrade the AGS proton beam power from the present 0.14 MW to higher than 1.0 MW and beyond for a neutrino facility. We have examined possible upgrade to the AGS accelerator complex that would meet the requirements of the proton beam of 1.0 MW for neutrino superbeam facility. The major contribution for the higher power is from the increase of the repetition rate of the AGS from 0.3 Hz to 2.5 Hz, with moderate increase from the intensity. To increase the AGS repetition rate we are proposing to replace booster with a 1.5 GeV linac. We will replace part of existing 200 MeV linac with coupled cavity structure from 116 MeV to 400 MeV and then add an additional 1.1 GeV superconducting linac to reach a final energy of 1.5 GeV for direct H- injection into the AGS. We will present possible choices for the upgrade and our choice and its design. C1 Brookhaven Natl Lab, Upton, NY 11973 USA. RP Raparia, D (reprint author), Brookhaven Natl Lab, Upton, NY 11973 USA. EM raparia@bnl.gov NR 7 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-8859-3 J9 IEEE PART ACC CONF PY 2005 BP 213 EP 215 PG 3 WC Instruments & Instrumentation; Physics, Particles & Fields SC Instruments & Instrumentation; Physics GA BDV94 UT WOS:000235745200064 ER PT B AU Liu, Y Beene, JR Havener, CC Liang, JF Havener, AC AF Liu, Y Beene, JR Havener, CC Liang, JF Havener, AC GP IEEE TI Isobar suppression by photodetachment in a gas-filled RF quadrupole ion guide SO 2005 IEEE PARTICLE ACCELERATOR CONFERENCE (PAC), VOLS 1-4 SE IEEE Particle Accelerator Conference LA English DT Proceedings Paper CT 21st Particle Accelerator Conference (PAC) CY MAY 16-20, 2005 CL Knoxville, TN SP IEEE ID NEGATIVE-IONS AB A novel technique based on selective non-resonant laser photodetachment in a radio frequency quadrupole ion guide is demonstrated for efficient suppression of isobaric contaminants in negative ion beams. The use of the quadrupole ion guide substantially increases the interaction time of the ions with the laser, significantly increasing the efficiency of the photodetachment process. In a proof-of-principle experiment, we achieved 95% suppression of (59)Co(-) ions by photodetachment while under identical conditions only 10% of (58)Ni(-) ions were neutralized. C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Liu, Y (reprint author), Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. EM liuy@ornl.gov NR 7 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-8859-3 J9 IEEE PART ACC CONF PY 2005 BP 222 EP 224 PG 3 WC Instruments & Instrumentation; Physics, Particles & Fields SC Instruments & Instrumentation; Physics GA BDV94 UT WOS:000235745200067 ER PT B AU Ostroumov, PN Shepard, KW Foster, GW Gonin, IV Romanov, GV AF Ostroumov, PN Shepard, KW Foster, GW Gonin, IV Romanov, GV GP IEEE TI Front end design of a multi-GeV H-minus linac SO 2005 IEEE PARTICLE ACCELERATOR CONFERENCE (PAC), VOLS 1-4 SE IEEE Particle Accelerator Conference LA English DT Proceedings Paper CT 21st Particle Accelerator Conference (PAC) CY MAY 16-20, 2005 CL Knoxville, TN SP IEEE AB The proposed 8-GeV driver at FNAL [1] is based on similar to 430 independently phased SC resonators. Significant cost savings are expected by using an rf power fan-out from high-power klystrons to multiple cavities. Successful development of superconducting (SQ multi-spoke resonators operating at similar to 345-350 MHz provides a strong basis for their application in the front end of multi-GeV linear accelerators. Such a front-end operating at 325 MHz would enable direct transition to high-gradient 1300 MHz SC TESLA-style cavities at similar to 400 MeV. The proposed front end consists of 5 sections: a conventional RFQ, room-temperature (RT) cross-bar H-type (CH) cavities, single-, double- and triple-spoke superconducting resonators. It is effective to use short RT CH-cavities between the RFQ and SC sections in the energy range 310 MeV as is discussed below. C1 Argonne Natl Lab, Div Phys, Argonne, IL 60439 USA. RP Ostroumov, PN (reprint author), Argonne Natl Lab, Div Phys, Argonne, IL 60439 USA. EM ostroumov@phy.anl.gov NR 9 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-8859-3 J9 IEEE PART ACC CONF PY 2005 BP 225 EP 227 PG 3 WC Instruments & Instrumentation; Physics, Particles & Fields SC Instruments & Instrumentation; Physics GA BDV94 UT WOS:000235745200068 ER PT B AU Ostroumov, PN Kolomiets, AA Aseev, VN AF Ostroumov, PN Kolomiets, AA Aseev, VN GP IEEE TI Heavy-ion beam dynamics in the RIA post-accelerator SO 2005 IEEE PARTICLE ACCELERATOR CONFERENCE (PAC), VOLS 1-4 SE IEEE Particle Accelerator Conference LA English DT Proceedings Paper CT 21st Particle Accelerator Conference (PAC) CY MAY 16-20, 2005 CL Knoxville, TN SP IEEE AB The RIA post-accelerator (RIB) includes three main sections: a room temperature injector with design ion charge-to-mass ratio 1/240 and output energy of similar to 93 keV/u, a superconducting (SC) linac for ions with charge-to-mass ratio 1/66 or higher up to an energy of similar to 1 MeV/u and a hip-her energy SC linac including existing ATLAS to produce 10 MeV/u beams up to uranium. Two strippers are installed between the sections. Extensive accelerator design studies and end-to-end beam dynamics simulations have been performed to minimize the cost of the linac while providing high-quality and high-intensity radioactive beams. Specifically, we have found that cost-effective acceleration in the front end can be provided by several hybrid RFQs proposed and developed for acceleration of low-velocity heavy ions. For beam focusing in the second section it is appropriate to use electrostatic lenses and SC quadrupoles inside common cryostats with the resonators. C1 Argonne Natl Lab, Argonne, IL 60439 USA. RP Ostroumov, PN (reprint author), Argonne Natl Lab, 9700 S Cass Ave, Argonne, IL 60439 USA. EM ostroumov@phy.anl.gov NR 9 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-8859-3 J9 IEEE PART ACC CONF PY 2005 BP 228 EP 230 PG 3 WC Instruments & Instrumentation; Physics, Particles & Fields SC Instruments & Instrumentation; Physics GA BDV94 UT WOS:000235745200069 ER PT B AU Ostroumov, PN Shepard, KW Delayen, JR AF Ostroumov, PN Shepard, KW Delayen, JR GP IEEE TI Review of a spoke-cavity design option for the RIA driver linac SO 2005 IEEE PARTICLE ACCELERATOR CONFERENCE (PAC), VOLS 1-4 SE IEEE Particle Accelerator Conference LA English DT Proceedings Paper CT 21st Particle Accelerator Conference (PAC) CY MAY 16-20, 2005 CL Knoxville, TN SP IEEE AB A design option for the 1.4 GV, multiple-charge-state driver linac required for the U. S. Rare Isotope Accelerator Project based on 345 MHz, 3-cell spoke-loaded cavities has been previously discussed [1]. This paper updates consideration of design options for the RIA driver, including recent results from numerically-modeling the multi-charge-state beam dynamics and also cold test results for prototype superconducting niobium three-spoke-loaded cavities. C1 Argonne Natl Lab, Argonne, IL 60439 USA. RP Ostroumov, PN (reprint author), Argonne Natl Lab, 9700 S Cass Ave, Argonne, IL 60439 USA. EM ostroumov@phy.anl.gov NR 9 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-8859-3 J9 IEEE PART ACC CONF PY 2005 BP 231 EP 233 PG 3 WC Instruments & Instrumentation; Physics, Particles & Fields SC Instruments & Instrumentation; Physics GA BDV94 UT WOS:000235745200070 ER PT B AU Aleksandrov, A Bartkoski, D Chu, P Cousineau, S Danilov, V Dodson, G Galambos, J Henderson, S Jeon, D Plum, M Stockli, M AF Aleksandrov, A Bartkoski, D Chu, P Cousineau, S Danilov, V Dodson, G Galambos, J Henderson, S Jeon, D Plum, M Stockli, M GP IEEE TI Beam dynamics studies and beam quality in the SNS normal-conducting linac SO 2005 IEEE PARTICLE ACCELERATOR CONFERENCE (PAC), VOLS 1-4 SE IEEE Particle Accelerator Conference LA English DT Proceedings Paper CT 21st Particle Accelerator Conference (PAC) CY MAY 16-20, 2005 CL Knoxville, TN SP IEEE AB The Spallation Neutron Source accelerator systems will provide a 1 GeV, 1.44 MW proton beam to a liquid mercury target for neutron production. The accelerator complex consists of an H- injector capable of producing 38 mA peak current, a I GeV linear accelerator, an accumulator ring and associated transport lines. The linear accelerator consists of a Drift Tube Linac, a Coupled-Cavity Linac and a Superconducting Linac which provide 1.5 mA average current to the accumulator ring. The staged beam commissioning of the accelerator complex is proceeding as component installation progresses. Recently, the normal-conducting linear accelerator was beam commissioned. A number of beam dynamics and beam quality measurements will be reported, including the measurement of transverse emittances in the H- injector, and the evolution of halo and emittance along the linac. C1 Oak Ridge Natl Lab, Spallat Neutron Source Project, Oak Ridge, TN 37830 USA. RP Aleksandrov, A (reprint author), Oak Ridge Natl Lab, Spallat Neutron Source Project, Oak Ridge, TN 37830 USA. NR 4 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-8859-3 J9 IEEE PART ACC CONF PY 2005 BP 234 EP 236 PG 3 WC Instruments & Instrumentation; Physics, Particles & Fields SC Instruments & Instrumentation; Physics GA BDV94 UT WOS:000235745200071 ER PT B AU Henderson, S Campisi, I Galambos, J Jeon, D Zhang, Y AF Henderson, S Campisi, I Galambos, J Jeon, D Zhang, Y GP IEEE TI Spallation Neutron Source Superconducting linac commissioning algorithms SO 2005 IEEE PARTICLE ACCELERATOR CONFERENCE (PAC), VOLS 1-4 SE IEEE Particle Accelerator Conference LA English DT Proceedings Paper CT 21st Particle Accelerator Conference (PAC) CY MAY 16-20, 2005 CL Knoxville, TN SP IEEE AB We describe the techniques which will be employed for establishing RF setpoints in the SNS Superconducting linac. The longitudinal tuneup will be accomplished using phase-scan methods, as well as a technique that makes use of the beam induced field in the unpowered cavity [1]. C1 Oak Ridge Natl Lab, Spallat Neutron Source Project, Oak Ridge, TN 37830 USA. RP Henderson, S (reprint author), Oak Ridge Natl Lab, Spallat Neutron Source Project, Oak Ridge, TN 37830 USA. NR 5 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-8859-3 J9 IEEE PART ACC CONF PY 2005 BP 237 EP 239 PG 3 WC Instruments & Instrumentation; Physics, Particles & Fields SC Instruments & Instrumentation; Physics GA BDV94 UT WOS:000235745200072 ER PT B AU Jeon, DO Chu, CM Danilov, V AF Jeon, DO Chu, CM Danilov, V GP IEEE TI Transverse matching techniques for the SNS linac SO 2005 IEEE PARTICLE ACCELERATOR CONFERENCE (PAC), VOLS 1-4 SE IEEE Particle Accelerator Conference LA English DT Proceedings Paper CT 21st Particle Accelerator Conference (PAC) CY MAY 16-20, 2005 CL Knoxville, TN SP IEEE AB It is crucial to minimize beam loss and machine activation by establishing optimal transverse matching for high intensity linear accelerator such as the Spallation Neutron Source linac. For matching DTL to CCL. there are four wire-scanners installed in series in CCL module I as proposed in [1]. A series of measurements was conducted to minimize envelope breathing and the results are presented here. As an independent approach, Chu et al is developing an application based on another technique by estimating rms emittance using the wire scanner profile data [2]. For matching MEBT to DTL, a technique of minimizing rms emittance was used and emittance data show that tail is minimized as well. C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Jeon, DO (reprint author), Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. EM jeond@ornl.gov NR 4 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-8859-3 J9 IEEE PART ACC CONF PY 2005 BP 240 EP 241 PG 2 WC Instruments & Instrumentation; Physics, Particles & Fields SC Instruments & Instrumentation; Physics GA BDV94 UT WOS:000235745200073 ER PT B AU Roy, PK Yu, SS Henestroza, E Eylon, S Waldron, WL Bieniosek, FM Leitner, M Shuman, D Greenway, WG Vanecek, DL Coleman, J Baca, D Logan, BG Welch, DR Rose, DV Thoma, C Davidson, RC Efthimion, RC Kaganovich, I Gilson, E Sefkov, AB Sharp, WM AF Roy, PK Yu, SS Henestroza, E Eylon, S Waldron, WL Bieniosek, FM Leitner, M Shuman, D Greenway, WG Vanecek, DL Coleman, J Baca, D Logan, BG Welch, DR Rose, DV Thoma, C Davidson, RC Efthimion, RC Kaganovich, I Gilson, E Sefkov, AB Sharp, WM GP IEEE TI Initial results on neutralized drift compression experiments (NDCX-IA) for high intensity ion beam SO 2005 IEEE PARTICLE ACCELERATOR CONFERENCE (PAC), VOLS 1-4 SE IEEE Particle Accelerator Conference LA English DT Proceedings Paper CT 21st Particle Accelerator Conference (PAC) CY MAY 16-20, 2005 CL Knoxville, TN SP IEEE AB Ion beam neutralization and compression experiments are designed to determine the feasibility of using compressed high intensity ion beams for high energy density physics (HEDP) experiments and for inertial fusion power. To quantitatively ascertain the various mechanisms and methods for beam compression, die Neutralized Drift Compression Experiment (NDCX) facility is being constructed at Lawrence Berkeley National Laboratory (LBNL). In the first neutralized drift compression experiment, a 280 KeV, 25 mA, K+ ion beam is longitudinally 50-fold compressed using an induction core to produce a velocity tilt. This compression ratio is measured using various diagnostics. C1 Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Roy, PK (reprint author), Lawrence Berkeley Lab, Berkeley, CA 94720 USA. NR 7 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-8859-3 J9 IEEE PART ACC CONF PY 2005 BP 263 EP 265 PG 3 WC Instruments & Instrumentation; Physics, Particles & Fields SC Instruments & Instrumentation; Physics GA BDV94 UT WOS:000235745200081 ER PT B AU Spampinato, PT Graves, VB Gabriel, TA Rennich, MJ Kirk, H Simos, N Tsang, T McDonald, K Titus, P Fabich, A Haseroth, H Lettry, J AF Spampinato, PT Graves, VB Gabriel, TA Rennich, MJ Kirk, H Simos, N Tsang, T McDonald, K Titus, P Fabich, A Haseroth, H Lettry, J GP IEEE TI A free-jet mercury system for use in a high-power target experiment SO 2005 IEEE PARTICLE ACCELERATOR CONFERENCE (PAC), VOLS 1-4 SE IEEE Particle Accelerator Conference LA English DT Proceedings Paper CT 21st Particle Accelerator Conference (PAC) CY MAY 16-20, 2005 CL Knoxville, TN SP IEEE AB A proof-of-principle experiment to investigate the interaction of a proton beam, high magnetic field, and high-Z target is planned for testing at CERN in 2007. The experiment is a multi-laboratory, international endeavor underwritten by the Muon Collider Collaboration. A freejet mercury target system that interacts with a high-power (1-MW) proton beam in a high magnetic field (15 T) is being designed. The mercury jet target is configured for insertion into the 15-cm-diameter bore of a high-field solenoid. The target features a hermetically sealed primary-containment volume that is enclosed in a secondary containment to ensure isolation of mercury vapors from the surrounding environment. The jet diameter is I cm, and the jet velocity will be up to 20 m/s. An optical diagnostic is incorporated into the target design to pen-nit observation of the dispersal of the mercury as a result of interaction with a 24-GeV proton beam with up to 20 x 10(12) protons per pulse. The target system also includes titanium alloy beam windows for the primary and secondary containments. C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Spampinato, PT (reprint author), Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. EM spampinatop@ornl.gov NR 2 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-8859-3 J9 IEEE PART ACC CONF PY 2005 BP 269 EP 271 PG 3 WC Instruments & Instrumentation; Physics, Particles & Fields SC Instruments & Instrumentation; Physics GA BDV94 UT WOS:000235745200083 ER PT B AU Plum, MA Holding, M McManamy, T AF Plum, MA Holding, M McManamy, T GP IEEE TI Beam parameter measurement and control at the SNS target SO 2005 IEEE PARTICLE ACCELERATOR CONFERENCE (PAC), VOLS 1-4 SE IEEE Particle Accelerator Conference LA English DT Proceedings Paper CT 21st Particle Accelerator Conference (PAC) CY MAY 16-20, 2005 CL Knoxville, TN SP IEEE AB The spallation neutron production target at the SNS facility is designed for 1.4 MW beam power. Both beam position and profile must be carefully controlled within narrow margins to avoid damage to the target. The position must be within 2 mm of the target center, and 90% of the beam must be within the nominal 70 mm. x 200 mm, spot size, without exceeding 0.18 A/m(2) peak beam current density This is a challenging problem, since most of the diagnostics are more than 9 in upstream of the target, and because the high beam power limits the lifetime of intercepting diagnostics. Our design includes a thermocouple halo monitor approximately 2 m upstream of the target face, and a beam position monitor, an insertable harp profile monitor, and a beam shape monitor approximately 9 m upstream. In this paper we will discuss our strategy to commission the beam delivery system and to meet target requirements during nominal operation. C1 Oak Ridge Natl Lab, Spallat Neutron Source, Oak Ridge, TN 37831 USA. RP Plum, MA (reprint author), Oak Ridge Natl Lab, Spallat Neutron Source, Oak Ridge, TN 37831 USA. NR 2 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-8859-3 J9 IEEE PART ACC CONF PY 2005 BP 272 EP 274 PG 3 WC Instruments & Instrumentation; Physics, Particles & Fields SC Instruments & Instrumentation; Physics GA BDV94 UT WOS:000235745200084 ER PT B AU Thoma, CH Welch, DR Eylon, S Henestroza, E Gilson, EP AF Thoma, CH Welch, DR Eylon, S Henestroza, E Gilson, EP GP IEEE TI LSP simulations of the neutralized drift compression experiment SO 2005 IEEE PARTICLE ACCELERATOR CONFERENCE (PAC), VOLS 1-4 SE IEEE Particle Accelerator Conference LA English DT Proceedings Paper CT 21st Particle Accelerator Conference (PAC) CY MAY 16-20, 2005 CL Knoxville, TN SP IEEE AB The Neutralized Drift Compression Experiment (NDCX) at Lawrence Berkeley National Laboratory involves the longitudinal compression of a singly-stripped K ion beam with a mean energy of 280 keV in a meter long plasma. We present simulation results of compression of the NDCX beam using the PIC code LSP. The NDCX beam encounters an acceleration gap with a time-dependent voltage that decelerates the head and accelerates the tail of a 500 ns pulse which is to be compressed 130 cm downstream. Results show good longitudinal compression without significant emittance growth, but a time-dependent focal length limits the beam radius. An explanation is given for the sizable defocusing effect of the voltage gap. An envelope calculation including the time-dependent focusing effect is in good agreement with the LSP simulations. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Thoma, CH (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. EM Carsten.Thoma@atk.com NR 2 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-8859-3 J9 IEEE PART ACC CONF PY 2005 BP 281 EP 283 PG 3 WC Instruments & Instrumentation; Physics, Particles & Fields SC Instruments & Instrumentation; Physics GA BDV94 UT WOS:000235745200087 ER PT B AU Vay, JL Furman, MA Cohen, RH Friedman, A Grote, DP AF Vay, JL Furman, MA Cohen, RH Friedman, A Grote, DP GP IEEE TI Initial self-consistent 3D electron-cloud simulations of the LHC beam with the code WARP plus POSINST SO 2005 IEEE PARTICLE ACCELERATOR CONFERENCE (PAC), VOLS 1-4 SE IEEE Particle Accelerator Conference LA English DT Proceedings Paper CT 21st Particle Accelerator Conference (PAC) CY MAY 16-20, 2005 CL Knoxville, TN SP IEEE AB We present initial results for the self-consistent beamcloud dynamics simulations for a sample LHC beam, using a newly developed set of modeling capability based on a merge [1] of the three-dimensional parallel Particle-In-Cell (PIC) accelerator code WARP [2] and the electron-cloud code POSINST [3]. Although the storage ring model we use as a test bed to contain the beam is much simpler and shorter than the LHC, its lattice elements are realistically modeled, as is the beam and the electron cloud dynamics. The simulated mechanisms for generation and absorption of the electrons at the walls are based on previously validated models available in POSINST [3, 4]. C1 LBNL, Berkeley, CA 94720 USA. RP Vay, JL (reprint author), LBNL, Berkeley, CA 94720 USA. EM jlvay@lbl.gov NR 12 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-8859-3 J9 IEEE PART ACC CONF PY 2005 BP 312 EP 314 PG 3 WC Instruments & Instrumentation; Physics, Particles & Fields SC Instruments & Instrumentation; Physics GA BDV94 UT WOS:000235745200098 ER PT B AU Wu, JH Raubenheimer, TO AF Wu, JH Raubenheimer, TO GP IEEE TI Luminosity optimization with offset, crossing angle, and distortion SO 2005 IEEE PARTICLE ACCELERATOR CONFERENCE (PAC), VOLS 1-4 SE IEEE Particle Accelerator Conference LA English DT Proceedings Paper CT 21st Particle Accelerator Conference (PAC) CY MAY 16-20, 2005 CL Knoxville, TN SP IEEE AB In a linear collider, sources of beam jitter due to kicker noise, quadrupole vibration and long-range transverse wakefields will lead to beam offsets and tilts at the Intersection Point (IP). In addition, sources of emittance dilution such as short-range transverse wakefields or dispersive errors will lead to internal beam distortions. When the IP disruption parameter is large, these beam imperfections will be amplified by a single bunch kink instability which will lead to luminosity loss. In this paper, we study the luminosity loss and then the optimization required to partially cancel the luminosity loss both analytically and with direct simulation. C1 SLAC, Menlo Pk, CA 94025 USA. RP Wu, JH (reprint author), SLAC, Menlo Pk, CA 94025 USA. EM jhwu@SLAC.Stanford.EDU NR 6 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-8859-3 J9 IEEE PART ACC CONF PY 2005 BP 315 EP 317 PG 3 WC Instruments & Instrumentation; Physics, Particles & Fields SC Instruments & Instrumentation; Physics GA BDV94 UT WOS:000235745200099 ER PT B AU Wu, JH Raubenheimer, TO Chao, AO Seryi, A Sramek, CK AF Wu, JH Raubenheimer, TO Chao, AO Seryi, A Sramek, CK GP IEEE TI Luminosity loss due to beam distortion and the beam-beam instability SO 2005 IEEE PARTICLE ACCELERATOR CONFERENCE (PAC), VOLS 1-4 SE IEEE Particle Accelerator Conference LA English DT Proceedings Paper CT 21st Particle Accelerator Conference (PAC) CY MAY 16-20, 2005 CL Knoxville, TN SP IEEE AB In a linear collider, sources of emittance dilution such as transverse wakefields or dispersive errors will couple the vertical phase space to the longitudinal position within the beam (the so-called 'banana effect'). When the Intersection Point (IP) disruption parameter is large, these beam distortions will be amplified by a single bunch kink instability which will lead to luminosity loss. We study this phenomena both analytically using linear theory and via numerical simulation. In particular, we examine the dependence of the luminosity loss on the wavelength of the beam distortions and the disruption parameter. This analysis may prove useful when optimizing the vertical disruption parameter for luminosity operation with given beam distortions. C1 SLAC, Menlo Pk, CA 94025 USA. RP Wu, JH (reprint author), SLAC, Menlo Pk, CA 94025 USA. EM jhwu@SLAC.Stanford.EDU NR 8 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-8859-3 J9 IEEE PART ACC CONF PY 2005 BP 318 EP 320 PG 3 WC Instruments & Instrumentation; Physics, Particles & Fields SC Instruments & Instrumentation; Physics GA BDV94 UT WOS:000235745200100 ER PT B AU Wang, L Hseuh, H Lee, YY Raparia, D Wei, J Cousineau, S Henderson, S AF Wang, L Hseuh, H Lee, YY Raparia, D Wei, J Cousineau, S Henderson, S GP IEEE TI Electron cloud in the collimator- and injection-region of the Spallation Neutron Source's accumulator ring SO 2005 IEEE PARTICLE ACCELERATOR CONFERENCE (PAC), VOLS 1-4 SE IEEE Particle Accelerator Conference LA English DT Proceedings Paper CT 21st Particle Accelerator Conference (PAC) CY MAY 16-20, 2005 CL Knoxville, TN SP IEEE AB Beam loss along the Spallation Neutron Source's accumulator ring is mainly located at the collimator region and injection region. This paper discusses the electron cloud build-up, control and collection at these two regions simulated with the three-dimension program CLOUDLAND. C1 Brookhaven Natl Lab, Upton, NY 11973 USA. RP Wang, L (reprint author), Brookhaven Natl Lab, Upton, NY 11973 USA. NR 5 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-8859-3 J9 IEEE PART ACC CONF PY 2005 BP 327 EP 329 PG 3 WC Instruments & Instrumentation; Physics, Particles & Fields SC Instruments & Instrumentation; Physics GA BDV94 UT WOS:000235745200104 ER PT B AU Davidson, RC Startsev, EA Kaganovich, I Qin, H AF Davidson, RC Startsev, EA Kaganovich, I Qin, H GP IEEE TI Multispecies Weibel instability for intense ion beam propagation through background plasma SO 2005 IEEE PARTICLE ACCELERATOR CONFERENCE (PAC), VOLS 1-4 SE IEEE Particle Accelerator Conference LA English DT Proceedings Paper CT 21st Particle Accelerator Conference (PAC) CY MAY 16-20, 2005 CL Knoxville, TN SP IEEE AB Properties of the multi-species electromagnetic Weibel instability are investigated for an intense ion beam propagating through background plasma. Assuming that the background plasma electrons provide complete charge and current neutralization, detailed linear stability properties are calculated within the framework of a macroscopic cold-fluid model for a wide range of system parameters. C1 Princeton Univ, Plasma Phys Lab, Princeton, NJ 08543 USA. RP Davidson, RC (reprint author), Princeton Univ, Plasma Phys Lab, Princeton, NJ 08543 USA. NR 8 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-8859-3 J9 IEEE PART ACC CONF PY 2005 BP 330 EP 332 PG 3 WC Instruments & Instrumentation; Physics, Particles & Fields SC Instruments & Instrumentation; Physics GA BDV94 UT WOS:000235745200105 ER PT B AU Kaganovich, ID Startsev, EA Davidson, RC AF Kaganovich, ID Startsev, EA Davidson, RC GP IEEE TI Hybrid quantum mechanical - Quasi-classical model for evaluating ionization and stripping cross sections in atom-ion collisions SO 2005 IEEE PARTICLE ACCELERATOR CONFERENCE (PAC), VOLS 1-4 SE IEEE Particle Accelerator Conference LA English DT Proceedings Paper CT 21st Particle Accelerator Conference (PAC) CY MAY 16-20, 2005 CL Knoxville, TN SP IEEE AB Ion-atom ionization cross sections are needed in many applications employing the propagation of fast ions through matter. When experimental data or full-scale theoretical calculations are non-existent, approximate methods must be used. The most robust and easy-to-use approximations include the Born approximation of quantum mechanics and the quasi-classical approach utilizing classical mechanics to-ether with the Bohr-Sommerfeld quantization rule. A hybrid method has been developed for calculation of the ionization and stripping cross sections of ions or atoms by fast ions by combining the Born approximation of quantum mechanics and the quasi-classical approach in the regions of impact parameters in which they are valid and summing the results to obtain the total cross section. The results of the modified approach agree better with the experimental data than either the Born approximation or the quasi-classical approach, applied separately. A new scaling formula for the ionization and stripping cross section of atoms and ions by fully stripped projectiles has been also proposed. The scaling has no fitting., Parameters and has been checked against I I different pairs of projectile and target atoms. All of the experimental data overlap on a single curve in the proposed scaled coordinates. C1 Princeton Univ, Plasma Phys Lab, Princeton, NJ 08543 USA. RP Kaganovich, ID (reprint author), Princeton Univ, Plasma Phys Lab, Princeton, NJ 08543 USA. EM ikaganov@pppl.gov NR 9 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-8859-3 J9 IEEE PART ACC CONF PY 2005 BP 333 EP 335 PG 3 WC Instruments & Instrumentation; Physics, Particles & Fields SC Instruments & Instrumentation; Physics GA BDV94 UT WOS:000235745200106 ER PT B AU Kaganovich, ID Startsev, EA Davidson, RC AF Kaganovich, ID Startsev, EA Davidson, RC GP IEEE TI Ion beam pulse interaction with background plasma in a solenoidal magnetic field SO 2005 IEEE PARTICLE ACCELERATOR CONFERENCE (PAC), VOLS 1-4 SE IEEE Particle Accelerator Conference LA English DT Proceedings Paper CT 21st Particle Accelerator Conference (PAC) CY MAY 16-20, 2005 CL Knoxville, TN SP IEEE ID FUSION; CHAMBER; TRANSPORT AB Background plasma can be used as an effective neutralization scheme to transport and compress intense ion beam pulses, and the application of a solenoidal magnetic field allows additional control and focusing of the beam pulse. Ion beam pulse propagation in a background plasma immersed in an applied solenoidal magnetic field has been studied both analytically and numerically with three different particle-in-cell codes (LSP, OOPIC-Pro and EDPIC) to cross-check the validity of the results. Very good charge and current neutralization is observed for high values of the solenoidal magnetic field. However, for intermediate values of the solenoidal magnetic field, current neutralization is a complex process, and a sizable self-magnetic field is generated at the head of the beam. Collective wave excitations are also generated ahead of the beam pulse. C1 Princeton Univ, Plasma Phys Lab, Princeton, NJ 08543 USA. RP Kaganovich, ID (reprint author), Princeton Univ, Plasma Phys Lab, Princeton, NJ 08543 USA. EM ikaganov@pppl.gov NR 12 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-8859-3 J9 IEEE PART ACC CONF PY 2005 BP 336 EP 338 PG 3 WC Instruments & Instrumentation; Physics, Particles & Fields SC Instruments & Instrumentation; Physics GA BDV94 UT WOS:000235745200107 ER PT B AU Qin, H Davidson, RC Hudson, SR Startsev, EA AF Qin, H Davidson, RC Hudson, SR Startsev, EA GP IEEE TI Nonlinear delta f particle simulations of collective effects in high-intensity bunched beams SO 2005 IEEE PARTICLE ACCELERATOR CONFERENCE (PAC), VOLS 1-4 SE IEEE Particle Accelerator Conference LA English DT Proceedings Paper CT 21st Particle Accelerator Conference (PAC) CY MAY 16-20, 2005 CL Knoxville, TN SP IEEE ID TEMPERATURE ANISOTROPY AB The collective effects in high-intensity bunched beams are described self-consistently by the nonlinear Vlasov-Maxwell equations. The nonlinear delta f method, a particle simulation method for solving the nonlinear Vlasov-Maxwell equations, is being used to study the collective effects in high-intensity bunched beams. The delta f method, as a nonlinear perturbative scheme, splits the distribution function into equilibrium and perturbed parts. The perturbed distribution function is represented as a weighted summation over discrete particles, where the particle orbits are advanced by equations of motion in the focusing field and self-generated fields, and the particle weights are advanced by the coupling between the perturbed fields and the zero-order distribution function. The nonlinear delta f method exhibits minimal noise and accuracy problems in comparison with standard particle-in-cell simulations. A self-consistent kinetic equilibrium is first established for high intensity bunched beams. Then, the collective excitations of the equilibrium are systematically investigated using the delta f method implemented in the Beam Equilibrium Stability and Transport (BEST) code. C1 Princeton Univ, Plasma Phys Lab, Princeton, NJ 08543 USA. RP Qin, H (reprint author), Princeton Univ, Plasma Phys Lab, Princeton, NJ 08543 USA. NR 10 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-8859-3 J9 IEEE PART ACC CONF PY 2005 BP 339 EP 341 PG 3 WC Instruments & Instrumentation; Physics, Particles & Fields SC Instruments & Instrumentation; Physics GA BDV94 UT WOS:000235745200108 ER PT B AU Covo, MK Molvik, A Friedman, A Westenskow, G Barnard, JJ Cohen, R Lund, SM Grote, D Seidl, P Kwan, JW Baca, D Bieniosek, F Celata, CM Vay, JL Vujic, JL AF Covo, MK Molvik, A Friedman, A Westenskow, G Barnard, JJ Cohen, R Lund, SM Grote, D Seidl, P Kwan, JW Baca, D Bieniosek, F Celata, CM Vay, JL Vujic, JL GP IEEE TI Beam energy scaling of ion-induced electron yield from K+ ions impact on stainless steel surfaces SO 2005 IEEE PARTICLE ACCELERATOR CONFERENCE (PAC), VOLS 1-4 SE IEEE Particle Accelerator Conference LA English DT Proceedings Paper CT 21st Particle Accelerator Conference (PAC) CY MAY 16-20, 2005 CL Knoxville, TN SP IEEE ID EMISSION; DEPENDENCE AB The cost of accelerators for heavy-ion inertial fusion energy (HIF) can be reduced by using the smallest possible clearance between the beam and the wall from the beamline. This increases beam loss to the walls, generating ion-induced electrons that could be trapped by beam space charge potential into an "electron cloud", which can cause degradation or loss of the ion beam. In order to test the physical mechanism model of ion-induced electrons production we have measured the impact of K+ ions with energies up to 400 KeV on stainless steel surfaces near grazing incidence, using the ion source test stand (STS-500) at LLNL. The electron yield will be discussed and compared with experimental measurements from I MeV K+ ions in the High-Current Experiment at LBN-L. C1 Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Covo, MK (reprint author), Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. EM michel@nuc.berkeley.edu RI J, H/C-1544-2012 NR 7 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-8859-3 J9 IEEE PART ACC CONF PY 2005 BP 345 EP 346 PG 2 WC Instruments & Instrumentation; Physics, Particles & Fields SC Instruments & Instrumentation; Physics GA BDV94 UT WOS:000235745200110 ER PT B AU Lund, SM Chawla, SR AF Lund, SM Chawla, SR GP IEEE TI Space-charge transport limits in periodic channels SO 2005 IEEE PARTICLE ACCELERATOR CONFERENCE (PAC), VOLS 1-4 SE IEEE Particle Accelerator Conference LA English DT Proceedings Paper CT 21st Particle Accelerator Conference (PAC) CY MAY 16-20, 2005 CL Knoxville, TN SP IEEE AB It has been empirically observed in both experiments and particle-in-cell simulations that space-charge-dominated beams suffer strong emittance growth and particle losses in alternating gradient quadrupole transport channels when the undepressed phase advance sigma(0) increases beyond about 85 degrees per lattice period. Although this criteria has been used extensively in practical designs of intense beam transport lattices, no theory exists that explains the limit. We propose a mechanism for the transport limit resulting from classes of halo particle resonances near the core of the beam that allow near-edge particles to rapidly increase in oscillation amplitude when the space-charge intensity and the flutter of the matched beam envelope are both sufficiently large. Due to a finite beam edge and/or perturbations, this mechanism can result in dramatic halo-driven increases in statistical beam phase space area, lost particles, and degraded transport. A core-particle model for a uniform density elliptical beam in a periodic focusing lattice is applied to parametrically analyze this process. C1 Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Lund, SM (reprint author), Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. NR 5 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-8859-3 J9 IEEE PART ACC CONF PY 2005 BP 347 EP 349 PG 3 WC Instruments & Instrumentation; Physics, Particles & Fields SC Instruments & Instrumentation; Physics GA BDV94 UT WOS:000235745200111 ER PT B AU McCarrick, JF Capotaso, GJ Chen, YJ AF McCarrick, JF Capotaso, GJ Chen, YJ GP IEEE TI Beam transport in a compact dielectric wall induction accelerator system for pulsed radiography SO 2005 IEEE PARTICLE ACCELERATOR CONFERENCE (PAC), VOLS 1-4 SE IEEE Particle Accelerator Conference LA English DT Proceedings Paper CT 21st Particle Accelerator Conference (PAC) CY MAY 16-20, 2005 CL Knoxville, TN SP IEEE AB Using dielectric wall accelerator technology, we are developing a compact induction accelerator system primarily intended for pulsed radiography. The accelerator would provide a 2-kA beam with an energy of 8 MeV, for a 20-30 ns flat-top. The design goal is to generate a 2-mm diameter, 10-rad x-ray source. We have a physics design of the system from injector to the x-ray converter. We present the results of injector modeling and PIC simulations of beam transport. We also discuss the predicted spot size and the on-axis x-ray dose. C1 Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. RP McCarrick, JF (reprint author), Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. NR 1 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-8859-3 J9 IEEE PART ACC CONF PY 2005 BP 350 EP 352 PG 3 WC Instruments & Instrumentation; Physics, Particles & Fields SC Instruments & Instrumentation; Physics GA BDV94 UT WOS:000235745200112 ER PT B AU Malitsky, N Brown, K Imperio, ND Kewisch, J Fedotov, A Luccio, A Pilat, F Ptitsyn, V Satogata, T Tepikian, S Wei, J Talman, R AF Malitsky, N Brown, K Imperio, ND Kewisch, J Fedotov, A Luccio, A Pilat, F Ptitsyn, V Satogata, T Tepikian, S Wei, J Talman, R GP IEEE TI Joining the RHIC online and off-line models SO 2005 IEEE PARTICLE ACCELERATOR CONFERENCE (PAC), VOLS 1-4 SE IEEE Particle Accelerator Conference LA English DT Proceedings Paper CT 21st Particle Accelerator Conference (PAC) CY MAY 16-20, 2005 CL Knoxville, TN SP IEEE AB The paper presents an interface encompassing the RHIC online ramp model and the UAL off-line simulation framework. The resulting consolidating facility aims to minimize the gap between design and operation data as well as to facilitate analysis of the RHIC performance and future upgrades. The interface is based on the Accelerator Description Exchange Format (ADXF[l]) that represents a snapshot of the RHIC online model. The same approach is also considered for integrating the AGS and RHIC modeling environments. C1 Brookhaven Natl Lab, Upton, NY 11973 USA. RP Malitsky, N (reprint author), Brookhaven Natl Lab, Upton, NY 11973 USA. EM malitsky@bnl.gov NR 7 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-8859-3 J9 IEEE PART ACC CONF PY 2005 BP 356 EP 358 PG 3 WC Instruments & Instrumentation; Physics, Particles & Fields SC Instruments & Instrumentation; Physics GA BDV94 UT WOS:000235745200114 ER PT B AU Lebrun, PLG Sen, T You, HM Yuan, ZW Todesco, E AF Lebrun, PLG Sen, T You, HM Yuan, ZW Todesco, E GP IEEE TI A betatron tune fitting package for the Tevatron 21.4 MHz Schottky SO 2005 IEEE PARTICLE ACCELERATOR CONFERENCE (PAC), VOLS 1-4 SE IEEE Particle Accelerator Conference LA English DT Proceedings Paper CT 21st Particle Accelerator Conference (PAC) CY MAY 16-20, 2005 CL Knoxville, TN SP IEEE AB The Fermilab Tevatron is equipped with two independent Schottky monitors for measurement of betatron tunes, one operating at 21.4 MHz and the other at 1.7 GHz. A new front-end and related data acquisition for the 21.4 MHz resonator has been installed and commissioned during the FY04 Collider RunII. Sophisticated fitting strategies are required to analyze the spectra. Optimization of this fitting package allows us to report tune and chromaticity measurements at almost I Hz. C1 Fermilab Natl Accelerator Lab, Batavia, IL 60510 USA. RP Lebrun, PLG (reprint author), Fermilab Natl Accelerator Lab, POB 500, Batavia, IL 60510 USA. EM lebrun@fnal.gov NR 9 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-8859-3 J9 IEEE PART ACC CONF PY 2005 BP 359 EP 361 PG 3 WC Instruments & Instrumentation; Physics, Particles & Fields SC Instruments & Instrumentation; Physics GA BDV94 UT WOS:000235745200115 ER PT B AU Michelotti, L Ostiguy, JF AF Michelotti, L Ostiguy, JF GP IEEE TI CHEF: An interactive program for accelerator optics SO 2005 IEEE PARTICLE ACCELERATOR CONFERENCE (PAC), VOLS 1-4 SE IEEE Particle Accelerator Conference LA English DT Proceedings Paper CT 21st Particle Accelerator Conference (PAC) CY MAY 16-20, 2005 CL Knoxville, TN SP IEEE AB We report the current status and our plans for the completion of CHEF, an interactive application for performing optics calculations in accelerator physics. CHEF uses high level graphical user interfaces to facilitate the exploitation of lower level tools incorporated into a hierarchy of C++ class libraries, making them usable by those not familiar with C++ programming. C1 Fermilab Natl Accelerator Lab, Batavia, IL 60510 USA. RP Michelotti, L (reprint author), Fermilab Natl Accelerator Lab, Batavia, IL 60510 USA. NR 2 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-8859-3 J9 IEEE PART ACC CONF PY 2005 BP 362 EP 364 PG 3 WC Instruments & Instrumentation; Physics, Particles & Fields SC Instruments & Instrumentation; Physics GA BDV94 UT WOS:000235745200116 ER PT B AU Bolshakov, TB Lebrun, P Panacek, S Papadimitriou, V Slaughter, J Xiao, A AF Bolshakov, TB Lebrun, P Panacek, S Papadimitriou, V Slaughter, J Xiao, A GP IEEE TI SDA-based diagnostic and analysis tools for collider run II SO 2005 IEEE PARTICLE ACCELERATOR CONFERENCE (PAC), VOLS 1-4 SE IEEE Particle Accelerator Conference LA English DT Proceedings Paper CT 21st Particle Accelerator Conference (PAC) CY MAY 16-20, 2005 CL Knoxville, TN SP IEEE AB Operating and improving the understanding of the Fermilab Accelerator Complex for the colliding beam experiments requires advanced software methods and tools. The Shot Data Analysis (SDA) has been developed to fulfill this need. Data from the Fermilab Accelerator Complex is stored in a relational database, and is served to programs and users via Web-based tools. Summary tables are systematically generated during and after a store. These tables (the Supertable, the Recomputed Emittances, the Recomputed Intensities and other tables) are discussed here. C1 Fermilab Natl Accelerator Lab, Batavia, IL 60510 USA. RP Bolshakov, TB (reprint author), Fermilab Natl Accelerator Lab, Batavia, IL 60510 USA. EM tbolsh@fnal.gov NR 4 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-8859-3 J9 IEEE PART ACC CONF PY 2005 BP 368 EP 370 PG 3 WC Instruments & Instrumentation; Physics, Particles & Fields SC Instruments & Instrumentation; Physics GA BDV94 UT WOS:000235745200118 ER PT B AU Allen, CK Schuster, E AF Allen, CK Schuster, E GP IEEE TI Automated beam steering using optimal control SO 2005 IEEE PARTICLE ACCELERATOR CONFERENCE (PAC), VOLS 1-4 SE IEEE Particle Accelerator Conference LA English DT Proceedings Paper CT 21st Particle Accelerator Conference (PAC) CY MAY 16-20, 2005 CL Knoxville, TN SP IEEE AB We present a steering algorithm which, with the aid of a model, allows the user to specify beam behavior throughout a beamline, rather than just at specified beam position monitor (BPM) locations. The model is used primarily to compute the values of the beam phase vectors from BPM measurements, and to define cost functions that describe die steering objectives. The steering problem is formulated as constrained optimization problem; however, by applying optimal control theory we can reduce it to an unconstrained optimization whose dimension is the number of control signals. C1 Los Alamos Natl Lab, Los Alamos, NM 87544 USA. RP Allen, CK (reprint author), Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87544 USA. EM ckallen@lanl.gov NR 7 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-8859-3 J9 IEEE PART ACC CONF PY 2005 BP 371 EP 373 PG 3 WC Instruments & Instrumentation; Physics, Particles & Fields SC Instruments & Instrumentation; Physics GA BDV94 UT WOS:000235745200119 ER PT B AU Beebe-Wang, J AF Beebe-Wang, J GP IEEE TI Fast automated decoupling at RHIC SO 2005 IEEE PARTICLE ACCELERATOR CONFERENCE (PAC), VOLS 1-4 SE IEEE Particle Accelerator Conference LA English DT Proceedings Paper CT 21st Particle Accelerator Conference (PAC) CY MAY 16-20, 2005 CL Knoxville, TN SP IEEE AB Coupling correction is essential for the operational performance of RHIC. The independence of the transverse degrees of freedom makes diagnostics and tune control easier, and it is advantageous to operate an accelerator close to the coupling resonance to minimize nearby nonlinear sidebands. An automated coupling correction application has been developed for RHIC routine operations. The application decouples RHIC globally by minimizing the tune separation through finding the optimal settings of two orthogonal skew quadrupole families. The program provides options of automatic, semi-automatic and manual decoupling operations. It accesses tune information from all RHIC tune measurement systems: the PLL (phase lock loop), the high frequency Schottky system, and the tune meter. It also supplies tune and skew quadrupole scans, finding the minimum tune separation, display the real time results and interface with the RHIC control system. We summarize the capabilities of the coupling correction application, and discuss the operational protections incorporated in the program. C1 Brookhaven Natl Lab, Upton, NY 11973 USA. RP Beebe-Wang, J (reprint author), Brookhaven Natl Lab, Upton, NY 11973 USA. EM bbwang@bnl.gov NR 2 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-8859-3 J9 IEEE PART ACC CONF PY 2005 BP 374 EP 376 PG 3 WC Instruments & Instrumentation; Physics, Particles & Fields SC Instruments & Instrumentation; Physics GA BDV94 UT WOS:000235745200120 ER PT B AU Xiao, A Bolshakov, T Lebrun, P McCrory, E Papadimitriou, V Slaughter, AJ AF Xiao, A Bolshakov, T Lebrun, P McCrory, E Papadimitriou, V Slaughter, AJ GP IEEE TI Tevatron beam lifetimes at injection using the Shot Data Analysis system SO 2005 IEEE PARTICLE ACCELERATOR CONFERENCE (PAC), VOLS 1-4 SE IEEE Particle Accelerator Conference LA English DT Proceedings Paper CT 21st Particle Accelerator Conference (PAC) CY MAY 16-20, 2005 CL Knoxville, TN SP IEEE AB The purpose of the Shot Data Acquisition and Analysis (SDA) system is to provide summary data on the Fermilab RunII accelerator complex and provide related software for detailed analyses. In this paper, we discuss such a specific analysis on Tevatron beam lifetimes at injection. These results are based on SDA data, tools and methodology. Beam lifetime is one of our most important diagnostics. An analysis of it can give information on intra beam scattering, aperture limitations, instabilities and most importantly beam-beam effects. Such an analysis gives us a better understanding of our machine, and will lead to an improved performance in the future. C1 Fermilab Natl Accelerator Lab, Batavia, IL 60510 USA. RP Xiao, A (reprint author), Fermilab Natl Accelerator Lab, POB 500, Batavia, IL 60510 USA. EM xiaoam@fnal.gov NR 3 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-8859-3 J9 IEEE PART ACC CONF PY 2005 BP 377 EP 379 PG 3 WC Instruments & Instrumentation; Physics, Particles & Fields SC Instruments & Instrumentation; Physics GA BDV94 UT WOS:000235745200121 ER PT B AU Pelaia, T Chu, P AF Pelaia, T Chu, P GP IEEE TI Beam trajectory correction for SNS SO 2005 IEEE PARTICLE ACCELERATOR CONFERENCE (PAC), VOLS 1-4 SE IEEE Particle Accelerator Conference LA English DT Proceedings Paper CT 21st Particle Accelerator Conference (PAC) CY MAY 16-20, 2005 CL Knoxville, TN SP IEEE AB Automated beam trajectory correction with dipole correctors is developed and tested during the Spallation Neutron Source (SNS) warm linac commissioning periods. The application is based on the XAL Java framework with newly developed optimization tools. Also, dipole trajectory corrector polarities and strengths, and beam position monitor (BPM) polarities were checked by an orbit difference program. The online model is used in both the orbit difference and the trajectory correction applications. Experimental data for both applications will be presented. C1 Oak Ridge Natl Lab, Spallat Neutron Source, Oak Ridge, TN 37831 USA. RP Pelaia, T (reprint author), Oak Ridge Natl Lab, Spallat Neutron Source, Oak Ridge, TN 37831 USA. NR 1 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-8859-3 J9 IEEE PART ACC CONF PY 2005 BP 383 EP 385 PG 3 WC Instruments & Instrumentation; Physics, Particles & Fields SC Instruments & Instrumentation; Physics GA BDV94 UT WOS:000235745200123 ER PT B AU Galambos, J Aleksandrov, A Deibele, C Henderson, S AF Galambos, J Aleksandrov, A Deibele, C Henderson, S GP IEEE TI Pasta - An RF phase scan and tuning application SO 2005 IEEE PARTICLE ACCELERATOR CONFERENCE (PAC), VOLS 1-4 SE IEEE Particle Accelerator Conference LA English DT Proceedings Paper CT 21st Particle Accelerator Conference (PAC) CY MAY 16-20, 2005 CL Knoxville, TN SP IEEE AB To assist the beam commissioning in the Spallation Neutron Source (SNS) linac, a general purpose Radio Frequency (RF) tuning application has been written to help set RF phase and amplitude. The method involves varying an Rf cavity amplitude and phase settings over a fairly large range and comparing the measured downstream beam phase response "signatures" to model predictions. The model input for cavity phase, cavity amplitude, and the beam energy are varied to best match observations. This scheme has advantages over other RF tuning techniques of not requiring intercepting devices (e.g. Faraday Cups), and not being restricted to a small linear response regime near the design values. The application developed here is general and can be applied to different RF structure types in the SNS linac. Example application for the SNS Drift Tube Linac (DTL) and Coupled Cavity Linac (CCL) structures will be shown. C1 Oak Ridge Natl Lab, Spallat Neutron Source, Oak Ridge, TN 37831 USA. RP Galambos, J (reprint author), Oak Ridge Natl Lab, Spallat Neutron Source, Oak Ridge, TN 37831 USA. NR 8 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-8859-3 J9 IEEE PART ACC CONF PY 2005 BP 386 EP 388 PG 3 WC Instruments & Instrumentation; Physics, Particles & Fields SC Instruments & Instrumentation; Physics GA BDV94 UT WOS:000235745200124 ER PT B AU Yin, L Kwan, TJT DeVolder, BG Snell, CM Bowers, KJ Smith, JR Carlson, R AF Yin, L Kwan, TJT DeVolder, BG Snell, CM Bowers, KJ Smith, JR Carlson, R GP IEEE TI Electron dynamics of the rod-pinch diode in the Cygnus experiment at Los Alamos SO 2005 IEEE PARTICLE ACCELERATOR CONFERENCE (PAC), VOLS 1-4 SE IEEE Particle Accelerator Conference LA English DT Proceedings Paper CT 21st Particle Accelerator Conference (PAC) CY MAY 16-20, 2005 CL Knoxville, TN SP IEEE ID RADIOGRAPHY SOURCE; MV AB In this work, two-dimensional particle-in-cell simulations are used to examine the electron physics in the rod-pinch diode, a device that can be used to produce a relatively low-energy (a few MeV) radiographic electron source. It is found that with diode parameters for which the electrons' dominant dynamics are approximated well as a magnetized fluid, the diode produces an electron source with a desired small spot size as the electrons drift to and impinge on the anode tip. However, for a large cathode-to-anode radius ratio, a population of electrons that consists predominantly of electrons emitted from the downstream surface of the cathode is found to propagate in the upstream direction and the diode may perform anomalously as a consequence. A method is proposed for improving the quality of the electron source by suppressing electron emission from the downstream cathode surface to reduce the presence of unmagnetized electrons. C1 LANL, Los Alamos, NM 87545 USA. RP Yin, L (reprint author), LANL, Los Alamos, NM 87545 USA. EM lyin@lanl.gov NR 10 TC 0 Z9 0 U1 3 U2 3 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-8859-3 J9 IEEE PART ACC CONF PY 2005 BP 400 EP 402 PG 3 WC Instruments & Instrumentation; Physics, Particles & Fields SC Instruments & Instrumentation; Physics GA BDV94 UT WOS:000235745200129 ER PT B AU Celata, CM Bieniosek, FM Seidl, PA Friedman, A Grote, DP Prost, L AF Celata, CM Bieniosek, FM Seidl, PA Friedman, A Grote, DP Prost, L GP IEEE TI The dynamic aperture of an electrostatic quadrupole lattice SO 2005 IEEE PARTICLE ACCELERATOR CONFERENCE (PAC), VOLS 1-4 SE IEEE Particle Accelerator Conference LA English DT Proceedings Paper CT 21st Particle Accelerator Conference (PAC) CY MAY 16-20, 2005 CL Knoxville, TN SP IEEE AB In heavy-ion-driven inertial fusion accelerator concepts, dynamic aperture is important to the cost of the accelerator, most especially for designs which envision multibeam linacs, where extra clearance for each beam greatly enlarges the transverse scale of the machine. In many designs the low-energy end of such an accelerator uses electrostatic quadrupole focusing. The dynamic aperture of such a lattice has been investigated here for intense, space-charge-dominated ion beams using the 2-D transverse slice version of the 3-D particle-in-cell simulation code WARP. The representation of the focusing field used is a 3-D solution of the Laplace equation for the biased focusing elements, as opposed to previous calculations, which used a less-accurate multipole approximation. 80-85% radial filling of the aperture is found to be possible. Results from the simulations, as well as corroborating data from the High Current Experiment at LBNL, are presented. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Celata, CM (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. NR 7 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-8859-3 J9 IEEE PART ACC CONF PY 2005 BP 403 EP 405 PG 3 WC Instruments & Instrumentation; Physics, Particles & Fields SC Instruments & Instrumentation; Physics GA BDV94 UT WOS:000235745200130 ER PT B AU Henestroza, E Peters, C Yu, SS Grote, DP Briggs, RJ AF Henestroza, E Peters, C Yu, SS Grote, DP Briggs, RJ GP IEEE TI Extraction compression and acceleration of high line charge density ion beams SO 2005 IEEE PARTICLE ACCELERATOR CONFERENCE (PAC), VOLS 1-4 SE IEEE Particle Accelerator Conference LA English DT Proceedings Paper CT 21st Particle Accelerator Conference (PAC) CY MAY 16-20, 2005 CL Knoxville, TN SP IEEE AB High Energy Density Physics (HEDP) applications require high line charge density ion beams. An efficient method to obtain this type of beams is to extract a long pulse, high current beam from a gun at high energy, and let the beam pass through a decelerating field to compress it. The low energy beam-bunch is loaded into a solenoid and matched to a Brillouin flow. The Brillouin equilibrium is independent of the energy if the relationship between the beam size (a), solenoid magnetic field strength (B) and line charge density is such that (Ba)<^>2 is proportional to the line charge density. Thus it is possible to accelerate a matched beam at constant line charge density. An experiment, NDCX-1c is being designed to test the feasibility of this type of injectors, where we will extract a I microsecond, 100 mA, potassium beam at 160 keV, decelerate it to 55 keV (density similar to 0.2 mu C/m), and load it into a 2.5 T solenoid where it will be accelerated to 100-150 keV (head to tail) at constant line charge density. The head-to-tail velocity tilt can be used to increase bunch compression and to control longitudinal beam expansion. We will present the physics design and numerical simulations of the proposed experiment. C1 LBNL, Berkeley, CA 94720 USA. RP Henestroza, E (reprint author), LBNL, Berkeley, CA 94720 USA. EM EHENESTROZA@LBL.GOV NR 3 TC 0 Z9 0 U1 0 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-8859-3 J9 IEEE PART ACC CONF PY 2005 BP 406 EP 408 PG 3 WC Instruments & Instrumentation; Physics, Particles & Fields SC Instruments & Instrumentation; Physics GA BDV94 UT WOS:000235745200131 ER PT B AU Waldron, WL Reginato, LL Briggs, RJ AF Waldron, WL Reginato, LL Briggs, RJ GP IEEE TI High voltage operation of helical pulseline structures for ion acceleration SO 2005 IEEE PARTICLE ACCELERATOR CONFERENCE (PAC), VOLS 1-4 SE IEEE Particle Accelerator Conference LA English DT Proceedings Paper CT 21st Particle Accelerator Conference (PAC) CY MAY 16-20, 2005 CL Knoxville, TN SP IEEE AB To accelerate ions using a helical pulseline requires the launching of a high voltage traveling wave with a waveform determined by the beam transport physics in order to maintain stability and acceleration. This waveform is applied to the front of the helix, creating a steep voltage ramp that moves down the helix, accelerating ions over distances much longer than the ramp length, An oil dielectric helix to demonstrate ion acceleration has been designed and fabricated. Helix design parameters, high voltage issues, input coupling methods, termination methods, and pulsers are described. Waveforms from the initial characterization of the oil dielectric helix are also described. C1 LBNL, Berkeley, CA 94720 USA. RP Waldron, WL (reprint author), LBNL, Berkeley, CA 94720 USA. NR 2 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-8859-3 J9 IEEE PART ACC CONF PY 2005 BP 409 EP 411 PG 3 WC Instruments & Instrumentation; Physics, Particles & Fields SC Instruments & Instrumentation; Physics GA BDV94 UT WOS:000235745200132 ER PT B AU Zhang, W Sandberg, J Weng, WT AF Zhang, W Sandberg, J Weng, WT GP IEEE TI High energy pulsed power system for AGS super neutrino focusing horn SO 2005 IEEE PARTICLE ACCELERATOR CONFERENCE (PAC), VOLS 1-4 SE IEEE Particle Accelerator Conference LA English DT Proceedings Paper CT 21st Particle Accelerator Conference (PAC) CY MAY 16-20, 2005 CL Knoxville, TN SP IEEE AB This paper present a preliminary design of a 300 kA. 2.5 Hz pulsed power system. This system will drive the focusing horn of proposed Brookhaven AGS Neutrino Super Beam Facility for Very Long Baseline Neutrino Oscillation Experiment. The peak output power of the horn pulsed power system will reach Giga-watts, and the upgraded AGS will be capable of delivering 1 MW in beam power. C1 Brookhaven Natl Lab, Upton, NY 11973 USA. RP Zhang, W (reprint author), Brookhaven Natl Lab, Upton, NY 11973 USA. NR 8 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-8859-3 J9 IEEE PART ACC CONF PY 2005 BP 415 EP 417 PG 3 WC Instruments & Instrumentation; Physics, Particles & Fields SC Instruments & Instrumentation; Physics GA BDV94 UT WOS:000235745200134 ER PT B AU Reeves, SR Jensen, CC AF Reeves, SR Jensen, CC GP IEEE TI NuMI proton kicker extraction magnet termination resistor system SO 2005 IEEE PARTICLE ACCELERATOR CONFERENCE (PAC), VOLS 1-4 SE IEEE Particle Accelerator Conference LA English DT Proceedings Paper CT 21st Particle Accelerator Conference (PAC) CY MAY 16-20, 2005 CL Knoxville, TN SP IEEE AB The temperature stability of the kicker magnet termination resistor assembly directly affects the field flatness and amplitude stability. Comprehensive thermal enhancements were made to the existing Main Injector resistor assembly design to satisfy NuMl performance specifications. Additionally, a fluid-processing system utilizing Fluorinert (c) FC-77 high-voltage dielectric was built to precisely control the setpoint temperature of the resistor assembly from 70 to 120F, required to maintain constant resistance during changing operational modes. The Fluorinert R must be continually processed to remove hazardous breakdown products caused by radiation exposure to prevent chemical attack of system components. Design details of the termination resistor assembly and Fluorinert (c) processing system are described. Early performance results will be presented. C1 Fermilab Natl Accelerator Lab, Batavia, IL 60510 USA. RP Reeves, SR (reprint author), Fermilab Natl Accelerator Lab, POB 500, Batavia, IL 60510 USA. NR 2 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-8859-3 J9 IEEE PART ACC CONF PY 2005 BP 418 EP 420 PG 3 WC Instruments & Instrumentation; Physics, Particles & Fields SC Instruments & Instrumentation; Physics GA BDV94 UT WOS:000235745200135 ER PT B AU Caporaso, GJ Briggs, RJ Poole, BR Nelson, SD AF Caporaso, GJ Briggs, RJ Poole, BR Nelson, SD GP IEEE TI Dispersion analysis of the pulseline accelerator SO 2005 IEEE PARTICLE ACCELERATOR CONFERENCE (PAC), VOLS 1-4 SE IEEE Particle Accelerator Conference LA English DT Proceedings Paper CT 21st Particle Accelerator Conference (PAC) CY MAY 16-20, 2005 CL Knoxville, TN SP IEEE AB We analyze the sheath helix model of the pulseline accelerator [1]. We find the dispersion relation for a shielded helix with a dielectric material between the shield and the helix and compare it against the results from 3-D electromagnetic simulations. Expressions for the fields near the beam axis are obtained. A scheme to taper the properties of the helix to maintain synchronism with the accelerated ions is described. An approximate circuit model of the system that includes beam loading is derived. C1 Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. RP Caporaso, GJ (reprint author), Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. NR 5 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-8859-3 J9 IEEE PART ACC CONF PY 2005 BP 424 EP 426 PG 3 WC Instruments & Instrumentation; Physics, Particles & Fields SC Instruments & Instrumentation; Physics GA BDV94 UT WOS:000235745200137 ER PT B AU Chen, YJ McCarrick, JF Nelson, SD AF Chen, YJ McCarrick, JF Nelson, SD GP IEEE TI Transverse beam instability in a compact dielectric wall induction accelerator SO 2005 IEEE PARTICLE ACCELERATOR CONFERENCE (PAC), VOLS 1-4 SE IEEE Particle Accelerator Conference LA English DT Proceedings Paper CT 21st Particle Accelerator Conference (PAC) CY MAY 16-20, 2005 CL Knoxville, TN SP IEEE AB Using the dielectric wall accelerator technology, we are developing a compact induction accelerator system primarily intended for pulsed radiography. Unlike the typical induction accelerator cell that is long compared with its accelerating gap width, the proposed dielectric wall induction accelerator cell is short and its accelerating gap width is comparable with the cell length. In this geometry, the RF modes may be coupled from one cell to the next. We will present recent results of RF modeling of the cells and a prediction of the transverse beam instability on a 2-kA, 8-MeV beam. C1 LLNL, Livermore, CA 94550 USA. RP Chen, YJ (reprint author), LLNL, Livermore, CA 94550 USA. NR 4 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-8859-3 J9 IEEE PART ACC CONF PY 2005 BP 427 EP 429 PG 3 WC Instruments & Instrumentation; Physics, Particles & Fields SC Instruments & Instrumentation; Physics GA BDV94 UT WOS:000235745200138 ER PT B AU DeHope, WJ Goerz, DA Kihara, R Ong, MM Vogtlin, GE Zentler, JM AF DeHope, WJ Goerz, DA Kihara, R Ong, MM Vogtlin, GE Zentler, JM GP IEEE TI An induction linac test stand SO 2005 IEEE PARTICLE ACCELERATOR CONFERENCE (PAC), VOLS 1-4 SE IEEE Particle Accelerator Conference LA English DT Proceedings Paper CT 21st Particle Accelerator Conference (PAC) CY MAY 16-20, 2005 CL Knoxville, TN SP IEEE ID ELECTRONS AB A single-cell test stand has been constructed at LLNL for studies aimed at improving the performance of the FXR radiographic facility. It has guided the development of diagnostics, pulsed power improvements, machine maintenance, and interface issues relevant to the entire accelerator. Based on this work, numerous machine improvements have been made which have resulted in demonstrable improvements in radiographic resolution and overall machine performance. C1 Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. RP DeHope, WJ (reprint author), Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. EM dehope1@llnl.gov NR 9 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-8859-3 J9 IEEE PART ACC CONF PY 2005 BP 430 EP 432 PG 3 WC Instruments & Instrumentation; Physics, Particles & Fields SC Instruments & Instrumentation; Physics GA BDV94 UT WOS:000235745200139 ER PT B AU Nelson, SD Caporaso, G Friedman, A Poole, BR Briggs, R Waldron, W AF Nelson, SD Caporaso, G Friedman, A Poole, BR Briggs, R Waldron, W GP IEEE TI Electromagnetic simulations of helical-based ion acceleration structures SO 2005 IEEE PARTICLE ACCELERATOR CONFERENCE (PAC), VOLS 1-4 SE IEEE Particle Accelerator Conference LA English DT Proceedings Paper CT 21st Particle Accelerator Conference (PAC) CY MAY 16-20, 2005 CL Knoxville, TN SP IEEE AB Helix structures have been proposed [1] for accelerating low energy ion beams using NW/m fields in order to increase the coupling efficiency of the pulsed power system and to tailor the electromagnetic wave propagation speed with the particle beam speed as the beam gains energy. Calculations presented here show the electromagnetic field as it propagates along the helix structure, field stresses around the helix structure (for voltage breakdown determination), optimizations to the helix and driving pulsed power waveform, and simulations showing test particles interacting with the simulated time varying fields. C1 LLNL, Livermore, CA 94550 USA. RP Nelson, SD (reprint author), LLNL, Livermore, CA 94550 USA. NR 4 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-8859-3 J9 IEEE PART ACC CONF PY 2005 BP 433 EP 435 PG 3 WC Instruments & Instrumentation; Physics, Particles & Fields SC Instruments & Instrumentation; Physics GA BDV94 UT WOS:000235745200140 ER PT B AU Nelson, SD Poole, BR AF Nelson, SD Poole, BR GP IEEE TI Electromagnetic simulations of Dielectric Wall Accelerator structures for electron beam acceleration SO 2005 IEEE PARTICLE ACCELERATOR CONFERENCE (PAC), VOLS 1-4 SE IEEE Particle Accelerator Conference LA English DT Proceedings Paper CT 21st Particle Accelerator Conference (PAC) CY MAY 16-20, 2005 CL Knoxville, TN SP IEEE AB Dielectric Wall Accelerator (DWA) technology incorporates the energy storage mechanism, the switching mechanism, and the acceleration mechanism for electron beams. Electromagnetic simulations of DWA structures includes these effects and also details of the switch configuration and how that switch time affects the electric field pulse which accelerates the particle beam. DWA structures include both bi-linear and bi-spiral configurations with field gradients on the order of 20MV/m and the simulations include the effects of the beampipe, the beampipe walls, and the DWA High Gradient Insulator (HGI) insulating stack. Design trade-offs include the transmission line impedance (typically a few ohms), equilibration ring optimization, driving switch inductances, and layer-to-layer coupling effects and the associated affect on the acceleration pulse's peak value. C1 LLNL, Livermore, CA 94550 USA. RP Nelson, SD (reprint author), LLNL, Livermore, CA 94550 USA. NR 2 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-8859-3 J9 IEEE PART ACC CONF PY 2005 BP 436 EP 438 PG 3 WC Instruments & Instrumentation; Physics, Particles & Fields SC Instruments & Instrumentation; Physics GA BDV94 UT WOS:000235745200141 ER PT B AU Poole, BR Nelson, SD Langdon, S AF Poole, BR Nelson, SD Langdon, S GP IEEE TI Advanced electric and magnetic material models for FDTD electromagnetic codes SO 2005 IEEE PARTICLE ACCELERATOR CONFERENCE (PAC), VOLS 1-4 SE IEEE Particle Accelerator Conference LA English DT Proceedings Paper CT 21st Particle Accelerator Conference (PAC) CY MAY 16-20, 2005 CL Knoxville, TN SP IEEE AB The modeling of dielectric and magnetic materials in the time domain is required for pulse power applications, pulsed induction accelerators', and advanced transmission lines. For example, most induction accelerator modules require the use of magnetic materials to provide adequate Volt-sec during the acceleration pulse. These models require hysteresis and saturation to simulate die saturation wavefront in a multipulse environment. In high voltage transmission line applications such as shock or soliton lines the dielectric is operating in a highly nonlinear regime, which require nonlinear models. Simple 1-D models are developed for fast parameterization of transmission line structures. In the case of nonlinear dielectrics, a simple analytic model describing the permittivity in terms of electric field is used in a 3-D finite difference time domain code (FDTD). In the case of magnetic materials, both rate independent and rate dependent Hodgdon magnetic material models have been implemented into 3-D FDTD codes and 1-D codes. C1 LLNL, Livermore, CA 94550 USA. RP Poole, BR (reprint author), LLNL, Livermore, CA 94550 USA. NR 3 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-8859-3 J9 IEEE PART ACC CONF PY 2005 BP 439 EP 441 PG 3 WC Instruments & Instrumentation; Physics, Particles & Fields SC Instruments & Instrumentation; Physics GA BDV94 UT WOS:000235745200142 ER PT B AU Wang, L Houck, T Westenskow, G AF Wang, L Houck, T Westenskow, G GP IEEE TI Design and simulation of an anode stalk support insulator SO 2005 IEEE PARTICLE ACCELERATOR CONFERENCE (PAC), VOLS 1-4 SE IEEE Particle Accelerator Conference LA English DT Proceedings Paper CT 21st Particle Accelerator Conference (PAC) CY MAY 16-20, 2005 CL Knoxville, TN SP IEEE AB An anode stalk support insulator in a magnetically insulated transmission line was designed and modeled. One of the important design criteria is that within space constraints, the electric field along the insulator surface has to be minimized in order to prevent a surface flashover. In order to further reduce the field on the insulator surface, metal rings between insulator layers were also specially shaped. To facilitate the design process, electric field simulations were performed to determine the maximum field stress on the insulator surfaces and the transmission line chamber. C1 LLNL, Livermore, CA 94550 USA. RP Wang, L (reprint author), LLNL, Livermore, CA 94550 USA. NR 1 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-8859-3 J9 IEEE PART ACC CONF PY 2005 BP 442 EP 444 PG 3 WC Instruments & Instrumentation; Physics, Particles & Fields SC Instruments & Instrumentation; Physics GA BDV94 UT WOS:000235745200143 ER PT B AU Soliday, R AF Soliday, R GP IEEE TI A Tcl/Tk widget for display of MEDM screens SO 2005 IEEE PARTICLE ACCELERATOR CONFERENCE (PAC), VOLS 1-4 SE IEEE Particle Accelerator Conference LA English DT Proceedings Paper CT 21st Particle Accelerator Conference (PAC) CY MAY 16-20, 2005 CL Knoxville, TN SP IEEE AB A new Tcl/Tk widget has been created to display MEDM screens inside a Tcl/Tk application. Tcl/Tk parses the MEDM input files and the appropriate widgets are created and linked to the associated process variables. One advantage of this approach is that an X-Windows emulator is not required to view and manipulate the MEDM screen Under a Windows operating system. Another benefit is that the MEDM screen can now be tightly integrated into a scripting language to attach higher-level logic to various process variable manipulations. Further details and examples of the new widget will be discussed. C1 Argonne Natl Lab, Argonne, IL 60439 USA. RP Soliday, R (reprint author), Argonne Natl Lab, 9700 S Cass Ave, Argonne, IL 60439 USA. NR 3 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-8859-3 J9 IEEE PART ACC CONF PY 2005 BP 479 EP 481 PG 3 WC Instruments & Instrumentation; Physics, Particles & Fields SC Instruments & Instrumentation; Physics GA BDV94 UT WOS:000235745200156 ER PT B AU Soliday, R Borland, M AF Soliday, R Borland, M GP IEEE TI Creating EPICS soft channels the easy way with sddspcas: Features and applications SO 2005 IEEE PARTICLE ACCELERATOR CONFERENCE (PAC), VOLS 1-4 SE IEEE Particle Accelerator Conference LA English DT Proceedings Paper CT 21st Particle Accelerator Conference (PAC) CY MAY 16-20, 2005 CL Knoxville, TN SP IEEE AB Using sddspcas, a portable channel access server that is configured by SDDS input files, it is relatively simple to create process variables (PVs). It can be run in a standalone mode or it can be run so that the PVs are checked to ensure that they don't conflict with other IOCs or portable channel access servers. It can also be run using the Run Control facility to prevent additional instances of the same sddspcas from being run. The SDDS configuration file provides the PV names, upper and lower limits, units, element counts if the PVs are waveforms, and the types of PVs. Valid types include various precision floats and integers as well as strings. One simple application of this program is that software developers can quickly test their code without requiring the coordination needed to update an IOC database to create PVs. Further details of the features. configuration, and applications of sddspcas will be discussed. C1 Argonne Natl Lab, Argonne, IL 60439 USA. RP Soliday, R (reprint author), Argonne Natl Lab, 9700 S Cass Ave, Argonne, IL 60439 USA. NR 7 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-8859-3 J9 IEEE PART ACC CONF PY 2005 BP 482 EP 484 PG 3 WC Instruments & Instrumentation; Physics, Particles & Fields SC Instruments & Instrumentation; Physics GA BDV94 UT WOS:000235745200157 ER PT B AU Brown, KA Binello, S Harvey, M Morris, J Rusek, A Tsoupas, N AF Brown, KA Binello, S Harvey, M Morris, J Rusek, A Tsoupas, N GP IEEE TI Event driven auto matic state modification of BNL's Booster for NASA Space Radiation Laboratory solar particle simulator SO 2005 IEEE PARTICLE ACCELERATOR CONFERENCE (PAC), VOLS 1-4 SE IEEE Particle Accelerator Conference LA English DT Proceedings Paper CT 21st Particle Accelerator Conference (PAC) CY MAY 16-20, 2005 CL Knoxville, TN SP IEEE AB The NASA Space Radiation Laboratory (NSRL) was constructed in collaboration with NASA for the purpose of performing radiation effect Studies for the NASA space program. The NSRL makes use of heavy ions in the range of 0.05 to 3 GeV/n slow extracted from BNL's AGS Booster. NASA is interested in reproducing the energy spectrum from a solar flare in the space environment, 161 a single ion species. To do this we have built and tested a set of software tools which allow the state of the Booster and the NSRL beam line to be changed automatically. In this report we will describe the system and present results of beam tests. C1 Brookhaven Natl Lab, C AD Dept, Upton, NY 11973 USA. RP Brown, KA (reprint author), Brookhaven Natl Lab, C AD Dept, Upton, NY 11973 USA. EM kbrown@bnl.gov NR 6 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-8859-3 J9 IEEE PART ACC CONF PY 2005 BP 485 EP 487 PG 3 WC Instruments & Instrumentation; Physics, Particles & Fields SC Instruments & Instrumentation; Physics GA BDV94 UT WOS:000235745200158 ER PT B AU Carcagno, RH Feher, S Lamm, M Makulski, A Nehring, R Orris, DF Pischalnikov, Y Tartaglia, M AF Carcagno, RH Feher, S Lamm, M Makulski, A Nehring, R Orris, DF Pischalnikov, Y Tartaglia, M GP IEEE TI An FPGA-based quench detection and protection system for superconducting accelerator magnets SO 2005 IEEE PARTICLE ACCELERATOR CONFERENCE (PAC), VOLS 1-4 SE IEEE Particle Accelerator Conference LA English DT Proceedings Paper CT 21st Particle Accelerator Conference (PAC) CY MAY 16-20, 2005 CL Knoxville, TN SP IEEE AB A new quench detection and protection system for superconducting accelerator magnets was developed for the Fermilab's Magnet Test Facility (MTF). This system is based on a Field-Programmable Gate Array (FPGA) module, and it is made of mostly commercially available, integrated hardware and software components. It provides all the functions of our existing VME-based quench detection and protection system, but in addition the new system is easily scalable to protect multiple magnets powered independently and provides a more powerful user interface and analysis tools. The new system has been used successfully for testing LHC Interaction Region Quadrupoles correctors and High Field Magnet HFDM04. In this paper we describe the system and present results. C1 Fermilab Natl Accelerator Lab, Batavia, IL 60510 USA. RP Carcagno, RH (reprint author), Fermilab Natl Accelerator Lab, POB 500, Batavia, IL 60510 USA. EM ruben@fnal.gov NR 4 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-8859-3 J9 IEEE PART ACC CONF PY 2005 BP 488 EP 490 PG 3 WC Instruments & Instrumentation; Physics, Particles & Fields SC Instruments & Instrumentation; Physics GA BDV94 UT WOS:000235745200159 ER PT B AU Allison, T Powers, T AF Allison, T Powers, T GP IEEE TI CEBAF distributed data acquisition system SO 2005 IEEE PARTICLE ACCELERATOR CONFERENCE (PAC), VOLS 1-4 SE IEEE Particle Accelerator Conference LA English DT Proceedings Paper CT 21st Particle Accelerator Conference (PAC) CY MAY 16-20, 2005 CL Knoxville, TN SP IEEE AB There are thousands of signals distributed throughout Jefferson Lab's Continuous Electron Beam Accelerator Facility (CEBAF) that are useful for troubleshooting and identifying instabilities. Many of these signals are only available locally or monitored by systems with small bandwidths that cannot identify fast transients. The Distributed Data Acquisition (Dist DAQ) system will sample and record these signals simultaneously at rates up to 40 Msps. Its primary function will be to provide waveform records from signals throughout CEBAF to the Experimental Physics and Industrial Control System (EPICS). The waveforms will be collected after the occurrence of an event trigger. These triggers will be derived from signals such as periodic timers or accelerator faults. The waveform data can then be processed to quickly identify beam transport issues, thus reducing down time and increasing CEBAF performance. The Dist DAQ system will be comprised of multiple standalone chassis distributed throughout CEBAF They will be interconnected via a fiber optic network to facilitate the global triggering of events. All of the chassis will also be connected directly to the CEBAF Ethernet and run EPICS locally. This allows for more flexibility than the typical configuration of a single board computer and other custom printed circuit boards (PCB) installed in a card cage. C1 Jefferson Lab, Newport News, VA 23606 USA. RP Allison, T (reprint author), Jefferson Lab, Newport News, VA 23606 USA. EM allison@jlab.org NR 0 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-8859-3 J9 IEEE PART ACC CONF PY 2005 BP 491 EP 493 PG 3 WC Instruments & Instrumentation; Physics, Particles & Fields SC Instruments & Instrumentation; Physics GA BDV94 UT WOS:000235745200160 ER PT B AU Bannister, ME Meyer, FW Sinclair, J AF Bannister, ME Meyer, FW Sinclair, J GP IEEE TI Control system for the ORNL Multicharged Ion Research Facility high-voltage platform SO 2005 IEEE PARTICLE ACCELERATOR CONFERENCE (PAC), VOLS 1-4 SE IEEE Particle Accelerator Conference LA English DT Proceedings Paper CT 21st Particle Accelerator Conference (PAC) CY MAY 16-20, 2005 CL Knoxville, TN SP IEEE AB A control system for the 250-kV platform and beamlines for accelerating and transporting ions produced by an all-permanent-magnet ECR ion source has been developed at the ORNL Multicharged Ion Research Facility. This system utilizes the Experimental Physics and Industrial Control System (EPICS) software to manipulate a programmable logic controller (PLC) and its associated I/O points. Additional control points are accessed by the EPICS Input/Output Controller (IOC) via RS-232 and GPIB interfaces. The Allen Bradley ControlLogix chassis located at each of the electrical potentials of the installation, that is at the source, platform, and ground potentials, are interconnected via Ethernet utilizing fiber optic transmission to bridge the different high voltage environments. The user interface for the EPICS IOC is built with the Extensible Display Manager (EDM) software. Performance of the control system during initial experiments using the high-voltage platform will be reported. C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Bannister, ME (reprint author), Oak Ridge Natl Lab, POB 2008, Oak Ridge, TN 37831 USA. EM bannisterme@ornl.gov NR 3 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-8859-3 J9 IEEE PART ACC CONF PY 2005 BP 494 EP 496 PG 3 WC Instruments & Instrumentation; Physics, Particles & Fields SC Instruments & Instrumentation; Physics GA BDV94 UT WOS:000235745200161 ER PT B AU Evans, K Smith, M AF Evans, K Smith, M GP IEEE TI Experience with the EPICS PV gateway at the APS SO 2005 IEEE PARTICLE ACCELERATOR CONFERENCE (PAC), VOLS 1-4 SE IEEE Particle Accelerator Conference LA English DT Proceedings Paper CT 21st Particle Accelerator Conference (PAC) CY MAY 16-20, 2005 CL Knoxville, TN SP IEEE AB The EPICS Process Variable Gateway [1] has become a stable, high-performance application that provides access to process variables while minimizing the impact on critical Input-Output Controllers (IOCs) and implementing additional access security. The additional access security typically prevents write access but is highly configurable. The Advanced Photon Source (APS) currently uses 40 Gateways running on 11. workstations to provide access to the machine subnet from the offices and for the individual experimental teams. These include reverse Gateways that allow administration of all 40 APS Gateways from a single MEDM [2] screen, even though the Gateways are running on separate networks. This administration includes starting, stopping, making and viewing reports, and viewing and editing access security files. There is one Gateway that provides process variable renaming. This paper provides an overview of the Gateways at the APS and describes the procedures that have been set LIP to use and administer them. C1 Argonne Natl Lab, Argonne, IL 60439 USA. RP Evans, K (reprint author), Argonne Natl Lab, 9700 S Cass Ave, Argonne, IL 60439 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-8859-3 J9 IEEE PART ACC CONF PY 2005 BP 497 EP 499 PG 3 WC Instruments & Instrumentation; Physics, Particles & Fields SC Instruments & Instrumentation; Physics GA BDV94 UT WOS:000235745200162 ER PT B AU Peng, S Hoff, L Smith, KS AF Peng, S Hoff, L Smith, KS GP IEEE TI The SNS ring LLRF control system SO 2005 IEEE PARTICLE ACCELERATOR CONFERENCE (PAC), VOLS 1-4 SE IEEE Particle Accelerator Conference LA English DT Proceedings Paper CT 21st Particle Accelerator Conference (PAC) CY MAY 16-20, 2005 CL Knoxville, TN SP IEEE AB The low-level RF control system for the SNS Ring differs considerably from that for the Linac. To accommodate requirements for higher data throughput and improved performance the system is based on a PCI interfaced Digital Signal Processor (DSP). In accordance with SNS standards, a VME-based PowerPC (c) is used, but advantage is taken of the on-board PMC slot which houses a Bittware (c) Hammerhead (c) PMC card with four AD-21162 DSPs. The EPICS system handles system configuration and data traffic while the DSP performs the low-level RF controls. Protocol and software to support both the PowerPC and the DSP have been developed. This paper presents the system design and initial testing experience. C1 Oak Ridge Natl Lab, SNS, Oak Ridge, TN 37830 USA. RP Peng, S (reprint author), Oak Ridge Natl Lab, SNS, Oak Ridge, TN 37830 USA. EM pengs@sns.gov NR 1 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-8859-3 J9 IEEE PART ACC CONF PY 2005 BP 500 EP 502 PG 3 WC Instruments & Instrumentation; Physics, Particles & Fields SC Instruments & Instrumentation; Physics GA BDV94 UT WOS:000235745200163 ER PT B AU Tang, J Ladd, P Williams, D Crandall, J AF Tang, J Ladd, P Williams, D Crandall, J GP IEEE TI The design and performance of the integrated spallation neutron source vacuum control system SO 2005 IEEE PARTICLE ACCELERATOR CONFERENCE (PAC), VOLS 1-4 SE IEEE Particle Accelerator Conference LA English DT Proceedings Paper CT 21st Particle Accelerator Conference (PAC) CY MAY 16-20, 2005 CL Knoxville, TN SP IEEE AB The Spallation Neutron Source (SNS) vacuum control systems have been developed within a collaboration of Lawrence Berkeley National Laboratory (LBNL), Los Alamos National Laboratory (LANL), Thomas Jefferson National Accelerator Facility (TJNAF), and Brookhaven National Laboratory (BNL). Each participating lab is responsible for a different section of the machine: LBNL for the Front-End section, LANL for the warm LINAC section, TJNAF for the cold LINAC section and BNL for the Ring section. Although a great deal of effort has been made to standardize vacuum instrumentation, components and global control system interfaces, the varied requirements of the different sections of the machine have made horizontal integration of the individual vacuum control systems both interesting and challenging. To support machine commissioning, the SNS control and vacuum teams have developed and implemented a series of test strategies and interlock schemes that have allowed horizontal vacuum system integration to be achieved in an effective manner. The design of the vacuum control system interlock schemes developed will be discussed together with the results of performance measurements made and experience gained in developing real-time control with an industrial Ethernet for this application. C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Tang, J (reprint author), Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. EM jtang@ornl.gov NR 5 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-8859-3 J9 IEEE PART ACC CONF PY 2005 BP 503 EP 505 PG 3 WC Instruments & Instrumentation; Physics, Particles & Fields SC Instruments & Instrumentation; Physics GA BDV94 UT WOS:000235745200164 ER PT B AU Feschenko, A Kiselev, Y Kovalishin, A Kravchuk, L Kvasha, A Tang, J Aleksandrov, A Champion, M Gibson, P Schubert, J AF Feschenko, A Kiselev, Y Kovalishin, A Kravchuk, L Kvasha, A Tang, J Aleksandrov, A Champion, M Gibson, P Schubert, J GP IEEE TI Spallation neutron source drift tube linac Resonance Control Cooling System modeling SO 2005 IEEE PARTICLE ACCELERATOR CONFERENCE (PAC), VOLS 1-4 SE IEEE Particle Accelerator Conference LA English DT Proceedings Paper CT 21st Particle Accelerator Conference (PAC) CY MAY 16-20, 2005 CL Knoxville, TN SP IEEE AB The Resonance Control Cooling System (RCCS) was designed by Los Alamos National Laboratory for the warm linac of the Spallation Neutron Source. The primary design focus was directed on water-cooling of individual component contributions. The sizing of the RCCS water skid was accomplished by means of a specially created SINDA/FLUINT model tailored to these system requirements. A new model was developed in Matlab Simulink and incorporates actual operational values and control valve interactions. The model took into consideration the dependence of RF input power on cavity detuning values during transients, time delays that resulted from water flows through the heat exchanger, the dynamic process of water warm-up in the cooling system due to dissipated RF power on the cavity surface, differing contributions on the cavity detuning due to drift tube and wall heating, and a dynamic model of the heat exchanger with characteristics, which were in close agreement to the real unit. Because of the Matlab Simulink model, investigation of a wide range of operating issues during both transient and steady state operation is now possible. Some results of the DTL RCCS modeling are presented. C1 Oak Ridge Natl Lab, SNS, Oak Ridge, TN 37831 USA. RP Feschenko, A (reprint author), Oak Ridge Natl Lab, SNS, Oak Ridge, TN 37831 USA. NR 1 TC 0 Z9 0 U1 0 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-8859-3 J9 IEEE PART ACC CONF PY 2005 BP 506 EP 508 PG 3 WC Instruments & Instrumentation; Physics, Particles & Fields SC Instruments & Instrumentation; Physics GA BDV94 UT WOS:000235745200165 ER PT B AU DeVan, W Hicks, S Lawson, G Wagner, W Wantland, D Williams, E AF DeVan, W Hicks, S Lawson, G Wagner, W Wantland, D Williams, E GP IEEE TI Using a control system Ethernet network as a field bus SO 2005 IEEE PARTICLE ACCELERATOR CONFERENCE (PAC), VOLS 1-4 SE IEEE Particle Accelerator Conference LA English DT Proceedings Paper CT 21st Particle Accelerator Conference (PAC) CY MAY 16-20, 2005 CL Knoxville, TN SP IEEE AB A major component of a typical accelerator distributed control system (DCS) is a dedicated, large-scale local area communications network (LAN). The SNS EPICS-based control system uses a LAN based on the popular IEEE-802.3 set of standards (Ethernet). Since the control system network infrastructure is available throughout the facility, and since Ethernet-based controllers are readily available, it is tempting to use the control system LAN for "fieldbus" communications to low-level control devices. These devices may or may not be compatible with the communications protocols, traffic levels, etc. This paper presents some of the benefits and risks of combining high-level DCS communications with low-level "field bus" communications on the same network, and describes measures taken at SNS to promote compatibility between devices connected to the control system network. C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP DeVan, W (reprint author), Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-8859-3 J9 IEEE PART ACC CONF PY 2005 BP 521 EP 523 PG 3 WC Instruments & Instrumentation; Physics, Particles & Fields SC Instruments & Instrumentation; Physics GA BDV94 UT WOS:000235745200170 ER PT B AU Portmann, G Corbett, J Terebilo, A AF Portmann, G Corbett, J Terebilo, A GP IEEE TI An accelerator control middle layer using Matlab SO 2005 IEEE PARTICLE ACCELERATOR CONFERENCE (PAC), VOLS 1-4 SE IEEE Particle Accelerator Conference LA English DT Proceedings Paper CT 21st Particle Accelerator Conference (PAC) CY MAY 16-20, 2005 CL Knoxville, TN SP IEEE AB Matlab is an interpretive programming language originally developed for convenient use with the UNPACK and EISPACK libraries. Matlab is appealing for accelerator physics because it is matrix-oriented, provides an active workspace for system variables, powerful graphics capabilities, built-in math libraries, and platform independence. A number of accelerator software toolboxes have been written in Matlab - the Accelerator Toolbox (AT) for model-based machine simulations, LOCO for on-line model calibration, and Matlab Channel Access (MCA) to connect with EPICS. The function of the MATLAB 'Middle Layer' is to provide a scripting language for machine simulations and on-line control, including non-EPICS based control systems. The Middle Layer has simplified and streamlined development of high-level applications including configuration control, energy ramp, orbit correction, photon beam steering, ID compensation, beam-based alignment, tune correction and response matrix measurement. The database-driven Middle Layer software is largely machine-independent and easy to port. Six accelerators presently use the software package with more scheduled to come on line soon. C1 LBNL, Berkeley, CA 94720 USA. RP Portmann, G (reprint author), LBNL, Berkeley, CA 94720 USA. NR 9 TC 0 Z9 0 U1 0 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-8859-3 J9 IEEE PART ACC CONF PY 2005 BP 527 EP 529 PG 3 WC Instruments & Instrumentation; Physics, Particles & Fields SC Instruments & Instrumentation; Physics GA BDV94 UT WOS:000235745200172 ER PT B AU Adelmann, A Ryne, RD Shalf, JM Siegerist, C AF Adelmann, A Ryne, RD Shalf, JM Siegerist, C GP IEEE TI H5PART: A portable high performance parallel data interface for particle simulations SO 2005 IEEE PARTICLE ACCELERATOR CONFERENCE (PAC), VOLS 1-4 SE IEEE Particle Accelerator Conference LA English DT Proceedings Paper CT 21st Particle Accelerator Conference (PAC) CY MAY 16-20, 2005 CL Knoxville, TN SP IEEE AB The very largest parallel particle simulations, for problems involving six dimensional phase space.. generate vast quantities of data. It is desirable to store such enormous datasets efficiently and also to share data effortlessly between data analysis tools such as PartView I I] and extensions to AVS/Express among other groups who are working on particle-based accelerator simulations. We define a very simple file schema built on top of HDF5 [2] (Hierarchical Data Format version 5) as well as an API that simplifies the reading/writing of the data to the HDF5 file format. HDF5 offers a self-describing machine-independent binary file format that supports scalable parallel I/O performance for MPI codes on computer systems ranging from laptops to supercomputers. The sample H5Part API is available for C, C++, and Fortran codes. The common file format will enable groups that use completely different simulation implementations to transparently share datasets and custom data analysis tools like PartView. We will show examples and benchmark data for various platforms. C1 LBNL, AFR, Berkeley, CA 94720 USA. RP Adelmann, A (reprint author), LBNL, AFR, Berkeley, CA 94720 USA. NR 2 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-8859-3 J9 IEEE PART ACC CONF PY 2005 BP 545 EP 547 PG 3 WC Instruments & Instrumentation; Physics, Particles & Fields SC Instruments & Instrumentation; Physics GA BDV94 UT WOS:000235745200178 ER PT B AU Tenenbaum, P AF Tenenbaum, P GP IEEE TI Lucretia: A matlab-based toolbox for the modelling and simulation of single-pass electron beam transport systems SO 2005 IEEE PARTICLE ACCELERATOR CONFERENCE (PAC), VOLS 1-4 SE IEEE Particle Accelerator Conference LA English DT Proceedings Paper CT 21st Particle Accelerator Conference (PAC) CY MAY 16-20, 2005 CL Knoxville, TN SP IEEE AB We report on Lucretia, a new simulation tool for the study of single-pass electron beam transport systems. Lucretia supports a combination of analytic and tracking techniques to model the tuning and operation of bunch compressors, linear accelerators, and beam delivery systems of linear colliders and linac-driven Free Electron Laser (FEL) facilities. Extensive use of Matlab scripting, graphics, and numerical capabilities maximize the flexibility of the system, and emphasis has been placed on representing and preserving the fixed relationships between elements (common girders. power supplies, etc.) which must be respected in the design of tuning algorithms. An overview of the code organization, some simple examples, and plans for future development are discussed. C1 SLAC, Stanford, CA USA. RP Tenenbaum, P (reprint author), SLAC, Stanford, CA USA. EM quarkpt@slac.stanford.edu NR 6 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-8859-3 J9 IEEE PART ACC CONF PY 2005 BP 551 EP 553 PG 3 WC Instruments & Instrumentation; Physics, Particles & Fields SC Instruments & Instrumentation; Physics GA BDV94 UT WOS:000235745200180 ER PT B AU Borland, M AF Borland, M GP IEEE TI elegantRingAnalysis: An interface for high-throughput analysis of storage ring lattices using elegant SO 2005 IEEE PARTICLE ACCELERATOR CONFERENCE (PAC), VOLS 1-4 SE IEEE Particle Accelerator Conference LA English DT Proceedings Paper CT 21st Particle Accelerator Conference (PAC) CY MAY 16-20, 2005 CL Knoxville, TN SP IEEE AB The code elegant is widely used for simulation of linacs for drivers for free-electron lasers. Less well known is that elegant is also a very capable code for simulation of storage rings. In this paper, we show a newly developed,graphical user interface that allows the user to easily take advantage of these capabilities. The interface is designed for use on a Linux cluster, providing very high throughput. It can also be used on a single computer. Among the features it gives access to are basic calculations (Twiss parameters, radiation integrals), phase-space tracking, nonlinear dispersion, dynamic aperture (on- and off-momentum), frequency map analysis, and collective effects (IBS, bunch-lengthening). Using a cluster, it is easy to get highly detailed dynamic aperture and frequency map results in a surprisingly short time. C1 Argonne Natl Lab, Argonne, IL 60439 USA. RP Borland, M (reprint author), Argonne Natl Lab, 9700 S Cass Ave, Argonne, IL 60439 USA. EM borland@aps.anl.gov NR 8 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-8859-3 J9 IEEE PART ACC CONF PY 2005 BP 554 EP 556 PG 3 WC Instruments & Instrumentation; Physics, Particles & Fields SC Instruments & Instrumentation; Physics GA BDV94 UT WOS:000235745200181 ER PT B AU Garnett, RW Wangler, TP Billen, JH Qiang, J Ryne, R Crandall, KR Ostroumov, P York, RC Zhao, Q AF Garnett, RW Wangler, TP Billen, JH Qiang, J Ryne, R Crandall, KR Ostroumov, P York, RC Zhao, Q GP IEEE TI Advanced beam-dynamics simulation tools for RIA SO 2005 IEEE PARTICLE ACCELERATOR CONFERENCE (PAC), VOLS 1-4 SE IEEE Particle Accelerator Conference LA English DT Proceedings Paper CT 21st Particle Accelerator Conference (PAC) CY MAY 16-20, 2005 CL Knoxville, TN SP IEEE AB We are developing multi-particle beam-dynamics simulation codes for RIA driver-linac simulations extending from the low-energy beam transport (LEBT) line to the end of the linac. These codes run on the NERSC parallel supercomputing platforms at LBNL, which allow us to run simulations with large numbers of macroparticles. The codes have the physics capabilities needed for RIA, including transport and acceleration of multiple-charge-state beams, beam-line elements such as high-voltage platforms within the linac, interdigital accelerating structures, charge-stripper foils, and capabilities for handling the effects of machine errors and other off-normal conditions. This year will mark the end of our project. In this paper we present the status of the work, describe some recent additions to the codes, and show some preliminary simulation results. C1 LANL, Los Alamos, NM 87544 USA. RP Garnett, RW (reprint author), LANL, Los Alamos, NM 87544 USA. NR 15 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-8859-3 J9 IEEE PART ACC CONF PY 2005 BP 557 EP 559 PG 3 WC Instruments & Instrumentation; Physics, Particles & Fields SC Instruments & Instrumentation; Physics GA BDV94 UT WOS:000235745200182 ER PT B AU Shang, H Borland, M AF Shang, H Borland, M GP IEEE TI A parallel Simplex optimizer and its application to high-brightness storage ring design SO 2005 IEEE PARTICLE ACCELERATOR CONFERENCE (PAC), VOLS 1-4 SE IEEE Particle Accelerator Conference LA English DT Proceedings Paper CT 21st Particle Accelerator Conference (PAC) CY MAY 16-20, 2005 CL Knoxville, TN SP IEEE AB An efficient parallel Simplex optimizer was developed that can on run Solaris and Linux clusters. It can optimize the result of running essentially any program or script that returns a penalty function value. We have used this optimizer with elegant to optimize the dynamic aperture of storage ring designs. This paper discusses the optimization algorithm and performance, design of penalty functions, optimization results, and applications in storage ring design. C1 Argonne Natl Lab, Argonne, IL 60439 USA. RP Shang, H (reprint author), Argonne Natl Lab, 9700 S Cass Ave, Argonne, IL 60439 USA. EM shang@aps.anl.gov NR 8 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-8859-3 J9 IEEE PART ACC CONF PY 2005 BP 560 EP 562 PG 3 WC Instruments & Instrumentation; Physics, Particles & Fields SC Instruments & Instrumentation; Physics GA BDV94 UT WOS:000235745200183 ER PT B AU Shang, H Borland, M Yao, CY Guo, W AF Shang, H Borland, M Yao, CY Guo, W GP IEEE TI ExperimentDesigner: A Tcl/Tk interface for creating experiments in EPICS SO 2005 IEEE PARTICLE ACCELERATOR CONFERENCE (PAC), VOLS 1-4 SE IEEE Particle Accelerator Conference LA English DT Proceedings Paper CT 21st Particle Accelerator Conference (PAC) CY MAY 16-20, 2005 CL Knoxville, TN SP IEEE AB Experiment-Designer is a Tcl/Tk interface that allows users to easily design and run complicated experiments using a convenient graphical user interface (GUI). Features include: process variable monitoring, which pauses the experiment when values are out of range; user-defined initialization, execution, and finalization sequences; support of complex execution chains containing actions such as setting controls, reading values, running external programs, interacting with the user, etc.; Collection Of Output data for convenient postprocessing; saving and loading of experiment configurations; convenient use of SDDS Toolkit programs; and execution of experiments from the command line without a GUI. C1 Argonne Natl Lab, Argonne, IL 60439 USA. RP Shang, H (reprint author), Argonne Natl Lab, 9700 S Cass Ave, Argonne, IL 60439 USA. EM shang@aps.anl.gov NR 6 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-8859-3 J9 IEEE PART ACC CONF PY 2005 BP 563 EP 565 PG 3 WC Instruments & Instrumentation; Physics, Particles & Fields SC Instruments & Instrumentation; Physics GA BDV94 UT WOS:000235745200184 ER PT B AU Bane, KLF Emma, P AF Bane, KLF Emma, P GP IEEE TI LiTrack: A fast longitudinal phase space tracking code with graphical user interface SO 2005 IEEE PARTICLE ACCELERATOR CONFERENCE (PAC), VOLS 1-4 SE IEEE Particle Accelerator Conference LA English DT Proceedings Paper CT 21st Particle Accelerator Conference (PAC) CY MAY 16-20, 2005 CL Knoxville, TN SP IEEE AB Linac-based light sources and linear colliders typically apply longitudinal phase space manipulations in their design, including electron bunch compression and wakefield-induced energy spread control. Several computer codes handle such issues, but most also require detailed information on the transverse focusing lattice. In fact, in most linear accelerators, the transverse distributions do not significantly affect the longitudinal, and can be ignored initially. This allows the use of a fast 2D code to study longitudinal aspects without time-consuming considerations of the transverse focusing. LiTrack is based on a 15-year old code (same name) originally written by one of us (KB), which is now a Matlab [1] code with additional features, such as graphical user interface, prompt output plotting, and functional call within a script. This single-bunch tracking code includes RF acceleration, bunch compression to 3rd order, geometric and resistive short-range wakefields, aperture limits, synchrotron radiation, and flexible output plotting. The code was used to design both the LCLS [2] and the SPPS [3] projects at SLAC and typically runs 10(5) particles in < 1 minute. We describe the features, show some examples, and provide free access to the code. C1 Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. RP Bane, KLF (reprint author), Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. EM Emma@SLAC.Stanford.edu NR 7 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-8859-3 J9 IEEE PART ACC CONF PY 2005 BP 566 EP 568 PG 3 WC Instruments & Instrumentation; Physics, Particles & Fields SC Instruments & Instrumentation; Physics GA BDV94 UT WOS:000235745200185 ER PT B AU Seeman, J AF Seeman, J GP IEEE TI PEP-II and KEKB operational status SO 2005 IEEE PARTICLE ACCELERATOR CONFERENCE (PAC), VOLS 1-4 SE IEEE Particle Accelerator Conference LA English DT Proceedings Paper CT 21st Particle Accelerator Conference (PAC) CY MAY 16-20, 2005 CL Knoxville, TN SP IEEE AB The present two B-Factories, PEP-II at SLAC in California and KEKB at KEK in Tsukuba, Japan, operate at the Upsilon 4S and have reached parameter levels unprecedented for e+e- colliders. They have provided very large data samples for their respective particle detectors, BaBar and BELLE. Luminosity has exceeded 1.5 x 10(34)/cm(2)/s. Beam currents have reached 2.5 A with 1600 positron bunches spaced by 4 nsec. Continuous injection with the detectors taking data has added significantly to data collection rates by about 40%. Bunch-by-bunch feedback systems damp strong longitudinal and transverse coupled bunch instabilities. The beam-beam interaction has allowed high tune shift levels even in the presence of parasitic crossing and crossing angle effects. Both B-Factory colliders have significant near term luminosity improvement programs. C1 Stanford Linear Accelerator Ctr, Menlo Pk, CA 94025 USA. RP Seeman, J (reprint author), Stanford Linear Accelerator Ctr, Menlo Pk, CA 94025 USA. EM seeman@slac.stanford.edu NR 8 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-8859-3 J9 IEEE PART ACC CONF PY 2005 BP 572 EP 576 PG 5 WC Instruments & Instrumentation; Physics, Particles & Fields SC Instruments & Instrumentation; Physics GA BDV94 UT WOS:000235745200187 ER PT B AU Roser, T AF Roser, T GP IEEE TI RHIC operational status SO 2005 IEEE PARTICLE ACCELERATOR CONFERENCE (PAC), VOLS 1-4 SE IEEE Particle Accelerator Conference LA English DT Proceedings Paper CT 21st Particle Accelerator Conference (PAC) CY MAY 16-20, 2005 CL Knoxville, TN SP IEEE AB As the first hadron accelerator and collider consisting of two independent superconducting rings RHIC has operated with a wide range of beam energies and particle species. Machine operation and performance will be reviewed that includes high luminosity gold-on-gold and copper-on-copper collisions at design beam energy (100 GeV/u), asymmetric deuteron-on-gold collisions as well as high energy polarized proton-proton collisions (100 GeV on 100 GeV). Plans for future upgrades of RHIC will also be discussed. C1 Brookhaven Natl Lab, Upton, NY 11793 USA. RP Roser, T (reprint author), Brookhaven Natl Lab, Upton, NY 11793 USA. NR 17 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-8859-3 J9 IEEE PART ACC CONF PY 2005 BP 577 EP 581 PG 5 WC Instruments & Instrumentation; Physics, Particles & Fields SC Instruments & Instrumentation; Physics GA BDV94 UT WOS:000235745200188 ER PT B AU McGinnis, D AF McGinnis, D GP IEEE TI Fermilab Tevatron operational status* SO 2005 IEEE PARTICLE ACCELERATOR CONFERENCE (PAC), VOLS 1-4 SE IEEE Particle Accelerator Conference LA English DT Proceedings Paper CT 21st Particle Accelerator Conference (PAC) CY MAY 16-20, 2005 CL Knoxville, TN SP IEEE AB The Fermilab Tevatron Proton-Antiproton Collider is currently the world's highest energy hadron collider. The luminosity of the Fermilab collider has been significantly increased with the Main Injector operating at its design goals. Further increases in luminosity have been the result of combining antiprotons from the Recycler and Accumulator storage rings. Recent commissioning of proton slip-stacking in the Main Injector has noticeably increased the antiproton accumulation rate. The increased stacking rate permits the sustained operation of using antiprotons from both the Accumulator and Recycler. Further increases in peak luminosity are expected from electron cooling in the Recycler and increased antiproton flux from the Antiproton Source. C1 Fermilab Natl Accelerator Lab, Batavia, IL 60510 USA. RP McGinnis, D (reprint author), Fermilab Natl Accelerator Lab, POB 500, Batavia, IL 60510 USA. NR 25 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-8859-3 J9 IEEE PART ACC CONF PY 2005 BP 582 EP 586 PG 5 WC Instruments & Instrumentation; Physics, Particles & Fields SC Instruments & Instrumentation; Physics GA BDV94 UT WOS:000235745200189 ER PT B AU Annala, G Bauer, P Bottura, L Martens, MA Sammut, N Velev, G Shiltsev, V AF Annala, G Bauer, P Bottura, L Martens, MA Sammut, N Velev, G Shiltsev, V GP IEEE TI Advances in the understanding and operations of superconducting colliders SO 2005 IEEE PARTICLE ACCELERATOR CONFERENCE (PAC), VOLS 1-4 SE IEEE Particle Accelerator Conference LA English DT Proceedings Paper CT 21st Particle Accelerator Conference (PAC) CY MAY 16-20, 2005 CL Knoxville, TN SP IEEE ID MAGNETS AB Chromaticity drift during injection is a well-known phenomenon in superconducting colliders, such as the Tevatron, HERA and RHIC. Imperfect compensation of the drift effects can contribute to beam loss and emittance growth. It is caused by the drift of the sextupole component in the dipole magnets due to current redistribution in its superconducting coils. Recently extensive studies of chromaticity drift were conducted at the Tevatron, aiming at the improvement of the luminosity performance in the ongoing run II. These studies included not only beam experiments, but also extensive off-fine magnetic measurements on spare Tevatron dipoles. Less known, until recently, is that chromaticity drift is often accompanied by tune and coupling drift. This was recently discovered in the Tevatron. We believe that these effects are the product of systematic beam offset in conjunction with the sextupole drifts (and their compensation in the chromaticity correctors). These discoveries are most relevant to the upcoming LHC, where the drift effects will have even more dramatic consequences given the high beam current. It is therefore not a surprise that CERN has been the source of major advances in the understanding of dynamic effects during the LHC superconducting magnet development. The following will briefly review the CERN results as well as those of the recent Fermilab studies. A new result, which will be presented here also, is related to fast drifts Occurring in the first few seconds of the injection plateau. Again, these fast drifts were observed first in the Tevatron and efforts are underway to explain them. Finally this paper will attempt to derive the implications of these drift effects on LHC commissioning and operation. C1 Fermilab Natl Accelerator Lab, Batavia, IL 60510 USA. RP Annala, G (reprint author), Fermilab Natl Accelerator Lab, POB 500, Batavia, IL 60510 USA. EM pbauer@fnal.gov NR 15 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-8859-3 J9 IEEE PART ACC CONF PY 2005 BP 587 EP 591 PG 5 WC Instruments & Instrumentation; Physics, Particles & Fields SC Instruments & Instrumentation; Physics GA BDV94 UT WOS:000235745200190 ER PT B AU Fischer, W AF Fischer, W GP IEEE TI Performance limitations in high-energy ion colliders SO 2005 IEEE PARTICLE ACCELERATOR CONFERENCE (PAC), VOLS 1-4 SE IEEE Particle Accelerator Conference LA English DT Proceedings Paper CT 21st Particle Accelerator Conference (PAC) CY MAY 16-20, 2005 CL Knoxville, TN SP IEEE AB High-energy ion colliders (hadron colliders operating with ions other than protons) are premier research tools for nuclear physics. The collision energy and high luminosity are important design and operations considerations. The experiments also expect flexibility with frequent changes the collision energy. detector fields, and ion species, including asymmetric collisions. For the creation, acceleration, and storage of bright intense ion beams limits are set by space charge, charge exchange, and intrabeam scattering effects. The latter leads to luminosity lifetimes of only a few hours for intense heavy ions beams. Currently, the Relativistic Heavy Ion Collider (RHIC) at BNL is the only operating high-energy ion collider. Later this decade the Large Hadron Collider (LHC), under construction at CERN, will also run with heavy ions. C1 Brookhaven Natl Lab, Upton, NY 11973 USA. RP Fischer, W (reprint author), Brookhaven Natl Lab, Upton, NY 11973 USA. EM Wolfram.Fischer@bnl.gov NR 31 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-8859-3 J9 IEEE PART ACC CONF PY 2005 BP 592 EP 596 PG 5 WC Instruments & Instrumentation; Physics, Particles & Fields SC Instruments & Instrumentation; Physics GA BDV94 UT WOS:000235745200191 ER PT B AU Seiya, K Berenc, T Dey, J Chase, B Kourbanis, I MacLachlan, J Meisner, K Pasquinelli, R Reid, J Rivetta, C Steimel, J AF Seiya, K Berenc, T Dey, J Chase, B Kourbanis, I MacLachlan, J Meisner, K Pasquinelli, R Reid, J Rivetta, C Steimel, J GP IEEE TI Status of slip stacking at Fermilab Main Injector SO 2005 IEEE PARTICLE ACCELERATOR CONFERENCE (PAC), VOLS 1-4 SE IEEE Particle Accelerator Conference LA English DT Proceedings Paper CT 21st Particle Accelerator Conference (PAC) CY MAY 16-20, 2005 CL Knoxville, TN SP IEEE AB To achieve an increase in proton intensity, the Fermilab Main Injector (MI) is using a stacking process called "slip stacking" [1]. The intensity will be doubled by injecting one train of bunches at a slightly lower energy, another at a slightly higher energy, then bringing them together for the final capture. Beam studies have been performed for this process and we have verified that, at least for low beam intensities, the stacking procedure works as expected [2]. For high intensity operation, an upgrade of the 4 kW solid state drivers to 8 kW was done during the last machine shut down, from August to November 2004. Slip stacking became operational in December 2004. C1 Fermilab Natl Accelerator Lab, Batavia, IL 60510 USA. RP Seiya, K (reprint author), Fermilab Natl Accelerator Lab, Batavia, IL 60510 USA. NR 5 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-8859-3 J9 IEEE PART ACC CONF PY 2005 BP 600 EP 602 PG 3 WC Instruments & Instrumentation; Physics, Particles & Fields SC Instruments & Instrumentation; Physics GA BDV94 UT WOS:000235745200193 ER PT B AU Alexahin, Y AF Alexahin, Y GP IEEE TI Theory and reality of beam-beam effects at hadron colliders SO 2005 IEEE PARTICLE ACCELERATOR CONFERENCE (PAC), VOLS 1-4 SE IEEE Particle Accelerator Conference LA English DT Proceedings Paper CT 21st Particle Accelerator Conference (PAC) CY MAY 16-20, 2005 CL Knoxville, TN SP IEEE AB The beam-beam phenomena in hadron colliders is just as rich as in e+e- machines: orbit and focusing perturbations, excitation of nonlinear resonances, coherent tuneshifts. Moreover, the absence of radiation damping and long duration of a store permit even high-order (and correspondingly weak) resonances to manifest themselves presenting a major challenge for both theoretical analysis and machine operation. The recent progress in understanding of and coping with the beam-beam effects at hadron colliders, primarily at the Tevatron is discussed. C1 Fermilab Natl Accelerator Lab, Batavia, IL 60510 USA. RP Alexahin, Y (reprint author), Fermilab Natl Accelerator Lab, POB 500, Batavia, IL 60510 USA. NR 10 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-8859-3 J9 IEEE PART ACC CONF PY 2005 BP 606 EP 610 PG 5 WC Instruments & Instrumentation; Physics, Particles & Fields SC Instruments & Instrumentation; Physics GA BDV94 UT WOS:000235745200195 ER PT B AU Luo, Y Cameron, P DellaPenna, A Fischer, W Laster, J Marusic, A Pilat, R Roser, T Trbojevic, D AF Luo, Y Cameron, P DellaPenna, A Fischer, W Laster, J Marusic, A Pilat, R Roser, T Trbojevic, D GP IEEE TI Global decoupling on the RHIC ramp SO 2005 IEEE PARTICLE ACCELERATOR CONFERENCE (PAC), VOLS 1-4 SE IEEE Particle Accelerator Conference LA English DT Proceedings Paper CT 21st Particle Accelerator Conference (PAC) CY MAY 16-20, 2005 CL Knoxville, TN SP IEEE AB The global betatron decoupling on the ramp is an important issue for the operation of the Relativistic Heavy Ion Collider (RHIC), especially in the RHIC polarized proton (pp) run. To avoid the major betatron and spin resonances on the ramp, the betatron tunes are constrained. And the rms value of the vertical closed orbit should be smaller than 0.5 mm. Both require the global coupling on the ramp to be well corrected. Several ramp decoupling schemes were found and tested at RHIC, like N-turn map decoupling, three-ramp correction, coupling amplitude modulation, and coupling phase modulation. In this article, the principles of these methods are shortly reviewed and compared. Among them, coupling angle modulation is a robust and fast one. It has been applied to the global decoupling in the routine RHIC operation. C1 Brookhaven Natl Lab, Upton, NY 11973 USA. RP Luo, Y (reprint author), Brookhaven Natl Lab, Upton, NY 11973 USA. NR 11 TC 0 Z9 0 U1 0 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-8859-3 J9 IEEE PART ACC CONF PY 2005 BP 614 EP 616 PG 3 WC Instruments & Instrumentation; Physics, Particles & Fields SC Instruments & Instrumentation; Physics GA BDV94 UT WOS:000235745200197 ER PT B AU Martens, MA Annala, J Bauer, P Shiltsev, V Velev, G AF Martens, MA Annala, J Bauer, P Shiltsev, V Velev, G GP IEEE TI Studies of the chromaticity, tune, and coupling drift in the Tevatron SO 2005 IEEE PARTICLE ACCELERATOR CONFERENCE (PAC), VOLS 1-4 SE IEEE Particle Accelerator Conference LA English DT Proceedings Paper CT 21st Particle Accelerator Conference (PAC) CY MAY 16-20, 2005 CL Knoxville, TN SP IEEE AB Chromaticity drift is a well-known and more or less well-understood phenomenon in superconducting colliders such as the Tevatron. Less known is the effect of tune and coupling drift, also observed in the Tevatron during injection. These effects are caused by field drifts in the superconducting magnets. Controlling the behavior of the tune, coupling, and chromaticity is an important part of reducing beam loss at injection and at the start of the Tevatron ramp. In this context we conducted several beam-studies during the period of April to August 2004 in which we measured the drift in the Tevatron chromaticity, tunes, and coupling during the injection porch. In some cases we also measured the snapback at the start of the ramp. We will present the results of these studies data and put them into context of the results of off-line magnetic measurements conducted in spare Tevatron dipoles. C1 Fermilab Natl Accelerator Lab, Batavia, IL 60510 USA. RP Martens, MA (reprint author), Fermilab Natl Accelerator Lab, Batavia, IL 60510 USA. NR 7 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-8859-3 J9 IEEE PART ACC CONF PY 2005 BP 617 EP 619 PG 3 WC Instruments & Instrumentation; Physics, Particles & Fields SC Instruments & Instrumentation; Physics GA BDV94 UT WOS:000235745200198 ER PT B AU Leitner, D Lyneis, CM AF Leitner, D Lyneis, CM GP IEEE TI High intensity high charge state ECR ion sources SO 2005 IEEE PARTICLE ACCELERATOR CONFERENCE (PAC), VOLS 1-4 SE IEEE Particle Accelerator Conference LA English DT Proceedings Paper CT 21st Particle Accelerator Conference (PAC) CY MAY 16-20, 2005 CL Knoxville, TN SP IEEE ID BEAMS; GHZ AB The next-generation heavy ion beam accelerators such as the proposed Rare Isotope Accelerator (RIA), the Radioactive Ion Beam Factory at RrKEN, the GSI upgrade project, the LHC-upgrade, and IMP in Lanzhou require a great variety of high charge state ion beams with a magnitude higher beam intensity than currently achievable. High performance Electron Cyclotron Resonance (ECR) ion sources can provide the flexibility since they can routinely produce beams from hydrogen to uranium. Over the last three decades, ECR ion sources have continued improving the available ion beam intensities by increasing the magnetic fields and ECR heating frequencies to enhance the confinement and the plasma density. With advances in superconducting magnet technology, a new generation of high field superconducting sources is now emerging. They are designed to meet the requirements of these next generation accelerator projects. The paper will briefly review the field of high performance ECR ion sources and the latest developments for high intensity ion beam production. The currently most advanced next-generation superconducting ECR ion source VENUS will be described in more detail. C1 Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. RP Leitner, D (reprint author), Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. NR 17 TC 0 Z9 0 U1 0 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-8859-3 J9 IEEE PART ACC CONF PY 2005 BP 620 EP 624 PG 5 WC Instruments & Instrumentation; Physics, Particles & Fields SC Instruments & Instrumentation; Physics GA BDV94 UT WOS:000235745200199 ER PT B AU Vinogradov, NE Aseev, VN Kern, MRL Ostroumov, PN Pardo, RC Scott, R AF Vinogradov, NE Aseev, VN Kern, MRL Ostroumov, PN Pardo, RC Scott, R GP IEEE TI Progress with the 2Q-LEBT facility for the RIA project SO 2005 IEEE PARTICLE ACCELERATOR CONFERENCE (PAC), VOLS 1-4 SE IEEE Particle Accelerator Conference LA English DT Proceedings Paper CT 21st Particle Accelerator Conference (PAC) CY MAY 16-20, 2005 CL Knoxville, TN SP IEEE AB The design goal of 400 kW uranium beam in the Rare Isotope Accelerator (RIA) Driver Linac can be achieved employing a concept of simultaneous acceleration of two charge states. It has been undertaken to build a prototype 2Q-injector of the RIA Driver Linac which includes an ECR ion source, a LEBT and one-segment of the prototype RFQ. The project called the 2Q-LEBT Facility is being developed in the Physics Division of ANL. Currently, the 2Q-LEBT Facility consists of BIE-100 ECR ion source. The reassembly and commissioning of the source has been completed. During the commissioning process we redesigned and manufactured a few components of the source to increase the beam production performance. A new diagnostic station has been designed and built for accurate measurements of the output beam emittance. The further development of the 2Q-LEBT Facility comprises installation of the source on 100 kV high-voltage platform, building an achromatic bending and transport system including the multi-harmonic buncher, and a full power 57.5 MHz RFQ segment. This report includes a detailed description of the 2Q-LEBT design and beam dynamics simulations along with emittance measurements for various beams. C1 Argonne Natl Lab, Argonne, IL 60439 USA. RP Vinogradov, NE (reprint author), Argonne Natl Lab, 9700 S Cass Ave, Argonne, IL 60439 USA. EM Vinogradov@phy.anl.gov NR 6 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-8859-3 J9 IEEE PART ACC CONF PY 2005 BP 625 EP 627 PG 3 WC Instruments & Instrumentation; Physics, Particles & Fields SC Instruments & Instrumentation; Physics GA BDV94 UT WOS:000235745200200 ER PT B AU Alessi, JG Beebe, EN Gould, O Kponou, A Lockey, R Pikin, A Prelec, K Raparia, D Ritter, J AF Alessi, JG Beebe, EN Gould, O Kponou, A Lockey, R Pikin, A Prelec, K Raparia, D Ritter, J GP IEEE TI Progress on test EBIS and the design of an EBIS-based RHIC preinjector SO 2005 IEEE PARTICLE ACCELERATOR CONFERENCE (PAC), VOLS 1-4 SE IEEE Particle Accelerator Conference LA English DT Proceedings Paper CT 21st Particle Accelerator Conference (PAC) CY MAY 16-20, 2005 CL Knoxville, TN SP IEEE AB Following the successful development of the Test EBIS at BNL [1-3], we now have a design for an EBIS-based heavy ion preinjector which would serve as an alternative to the Tandem Van de Graaffs in providing beams for RHIC and the NASA Space Radiation Laboratory. This baseline design includes an EBIS producing mA-level currents of heavy ions (ex. Au(32+)) in similar to 10-20 mu s pulses, injecting into an RFQ which accelerates the beams to 300 keV/amu, followed by an IH linac accelerating to 2 MeV/amu. Some details of this design are presented, as well as recent experimental results on the Test EBIS. C1 BNL, Upton, NY 11967 USA. RP Alessi, JG (reprint author), BNL, Upton, NY 11967 USA. EM alessi@bnl.gov NR 7 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-8859-3 J9 IEEE PART ACC CONF PY 2005 BP 628 EP 630 PG 3 WC Instruments & Instrumentation; Physics, Particles & Fields SC Instruments & Instrumentation; Physics GA BDV94 UT WOS:000235745200201 ER PT B AU Welton, RF Stockli, MP Murray, SN Keller, R AF Welton, RF Stockli, MP Murray, SN Keller, R GP IEEE TI Advances in the performance of the SNS ion source SO 2005 IEEE PARTICLE ACCELERATOR CONFERENCE (PAC), VOLS 1-4 SE IEEE Particle Accelerator Conference LA English DT Proceedings Paper CT 21st Particle Accelerator Conference (PAC) CY MAY 16-20, 2005 CL Knoxville, TN SP IEEE ID SPALLATION NEUTRON SOURCE AB The ion source developed for the Spallation Neutron Source* (SNS) is a radio frequency, multi-cusp source designed to produce similar to 40 mA of H with a normalized rms emittance of less than 0.2 pi(.)mm(.)mrad. To date the source has been utilized in commissioning the SNS accelerator, delivering beams of 10-50 mA with duty-factors of typically similar to 0.1% for operational periods of several weeks, achieving an availability of similar to 99%. Ultimately the SNS facility will require beam duty-factors of 6% (1 ms pulse length, 60 Hz repetition rate, 21 day run-period). Over the last year, several experiments were performed in which the ion source was continuously operated at full duty-factor and maximum beam current on a test stand. Average beam attenuation rates of similar to 5 mA/day were observed and beams in excess of 30 mA could only be sustained for periods of several hours. Recently, a breakthrough in our understanding of the Cs release process has led to the development of a new source conditioning technique which resulted in a dramatic increase in beam persistence with time. H(-) beam attenuation rates have been improved to similar to 0.4 mA/day, allowing beams in excess of 30 mA to be delivered continuously at full duty factor for periods of similar to 16 days. C1 Oak Ridge Natl Lab, Oak Ridge, TN 37830 USA. RP Welton, RF (reprint author), Oak Ridge Natl Lab, POB 2008, Oak Ridge, TN 37830 USA. NR 12 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-8859-3 J9 IEEE PART ACC CONF PY 2005 BP 631 EP 633 PG 3 WC Instruments & Instrumentation; Physics, Particles & Fields SC Instruments & Instrumentation; Physics GA BDV94 UT WOS:000235745200202 ER PT B AU Lewellen, JW AF Lewellen, JW GP IEEE TI Future directions in electron sources SO 2005 IEEE PARTICLE ACCELERATOR CONFERENCE (PAC), VOLS 1-4 SE IEEE Particle Accelerator Conference LA English DT Proceedings Paper CT 21st Particle Accelerator Conference (PAC) CY MAY 16-20, 2005 CL Knoxville, TN SP IEEE ID RF GUNS AB The emittance-compensated rf photoinjector is in the process of evolving from an experiment in and of itself, to a laboratory instrument, to a workhorse component of large user facilities such as next-generation light sources. In recent years the performance achieved by the standard pi-mode design has approached the levels predicted by theory and simulation. The basic design has been scaled from X-band down to less than 1 GHz in terms of operating frequency, and superconducting designs are presently undergoing initial testing at various locations. The requirements for linac-based light sources will require at least one order of magnitude improvement in beam quality; other applications, such as electron microscopes or high-energy electron lithography, require still greater improvements. The migration towards fully superconducting accelerators provides some additional design challenges. This paper briefly presents requirements for some future applications, and presents four new approaches to extending injector performance: the diamond-emitter photocathode, the planar focusing cathode, the magnetic-mode emittance compensation technique, and the field-emission-gated cathode. C1 Argonne Natl Lab, Argonne, IL 60439 USA. RP Lewellen, JW (reprint author), Argonne Natl Lab, 9700 S Cass Ave, Argonne, IL 60439 USA. EM Lewellen@aps.anl.gov NR 22 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-8859-3 J9 IEEE PART ACC CONF PY 2005 BP 639 EP 643 PG 5 WC Instruments & Instrumentation; Physics, Particles & Fields SC Instruments & Instrumentation; Physics GA BDV94 UT WOS:000235745200204 ER PT B AU Loos, H Dowell, D Gilevich, S Limborg-Deprey, C Shen, Y Murphy, J Sheehy, B Tsang, T Wang, X Wu, Z Serafini, L Boscolo, M Ferrario, M Petrarca, M Vicario, C AF Loos, H Dowell, D Gilevich, S Limborg-Deprey, C Shen, Y Murphy, J Sheehy, B Tsang, T Wang, X Wu, Z Serafini, L Boscolo, M Ferrario, M Petrarca, M Vicario, C GP IEEE TI Temporal e-beam shaping in an S-band accelerator SO 2005 IEEE PARTICLE ACCELERATOR CONFERENCE (PAC), VOLS 1-4 SE IEEE Particle Accelerator Conference LA English DT Proceedings Paper CT 21st Particle Accelerator Conference (PAC) CY MAY 16-20, 2005 CL Knoxville, TN SP IEEE AB New short-wavelength SASE light sources will require very bright electron beams, brighter in some cases than is now possible. One method for improving brightness involves the careful shaping of the electron bunch to control the degrading effects of its space charge forces. We study this experimentally in an S-band system, by using an acousto-optical programmable dispersive filter to shape the photocathode laser pulse that drives the RF photoinjector. We report on the efficacy of shaping from the IR through the UV, and the effects of shaping on the electron beam dynamics. C1 SLAC, Menlo Pk, CA 94025 USA. RP Loos, H (reprint author), SLAC, Menlo Pk, CA 94025 USA. EM loos@slac.slanford.edu NR 6 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-8859-3 J9 IEEE PART ACC CONF PY 2005 BP 644 EP 646 PG 3 WC Instruments & Instrumentation; Physics, Particles & Fields SC Instruments & Instrumentation; Physics GA BDV94 UT WOS:000235745200205 ER PT B AU Cousineau, S AF Cousineau, S GP IEEE TI Benchmark of space charge simulations and comparison with experimental results for high intensity, low energy accelerators SO 2005 IEEE PARTICLE ACCELERATOR CONFERENCE (PAC), VOLS 1-4 SE IEEE Particle Accelerator Conference LA English DT Proceedings Paper CT 21st Particle Accelerator Conference (PAC) CY MAY 16-20, 2005 CL Knoxville, TN SP IEEE AB Space charge effects are a major contributor to beam halo and emittance growth leading to beam loss in high intensity, low energy accelerators. As future accelerators strive toward unprecedented levels of beam intensity and beam loss control, a more comprehensive understanding of space charge effects is required. A wealth of simulation tools have been developed for modeling beams in linacs and rings, and with the growing availability of high-speed computing systems, computationally expensive problems that were inconceivable a decade ago are now being handled with relative ease. This has opened the field for realistic simulations of space charge effects, including detailed benchmarks with experimental data. A great deal of effort is being focused in this direction, and several recent benchmark studies have produced remarkably successful results. This paper reviews the achievements in space charge benchmarking in the last few years, and discusses challenges that remain. C1 Oak Ridge Natl Lab, Oak Ridge, TN 37830 USA. RP Cousineau, S (reprint author), Oak Ridge Natl Lab, Oak Ridge, TN 37830 USA. NR 21 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-8859-3 J9 IEEE PART ACC CONF PY 2005 BP 661 EP 665 PG 5 WC Instruments & Instrumentation; Physics, Particles & Fields SC Instruments & Instrumentation; Physics GA BDV94 UT WOS:000235745200210 ER PT B AU Ranjbar, VH AF Ranjbar, VH GP IEEE TI Chromaticity and impedance effect on the Transverse motion of longitudinal bunch slices in the Tevatron SO 2005 IEEE PARTICLE ACCELERATOR CONFERENCE (PAC), VOLS 1-4 SE IEEE Particle Accelerator Conference LA English DT Proceedings Paper CT 21st Particle Accelerator Conference (PAC) CY MAY 16-20, 2005 CL Knoxville, TN SP IEEE AB The Transverse turn-by-turn evolution of a bunch slice are examined considering chromatic and impedance effects. A quasi-analytical approximation is developed using perturbative expansion of Hills equation with a wake field. This approximation is compared to turn-by-turn measurements taken in the Tevatron and from this linear and second order chromaticity, and Impedance are calculated as well as beam stability thresholds. C1 Fermilab Natl Accelerator Lab, Batavia, IL USA. RP Ranjbar, VH (reprint author), Fermilab Natl Accelerator Lab, Batavia, IL USA. NR 4 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-8859-3 J9 IEEE PART ACC CONF PY 2005 BP 672 EP 674 PG 3 WC Instruments & Instrumentation; Physics, Particles & Fields SC Instruments & Instrumentation; Physics GA BDV94 UT WOS:000235745200213 ER PT B AU Cai, Y Seeman, J Kozanecki, W Ohmi, K Tawada, M AF Cai, Y Seeman, J Kozanecki, W Ohmi, K Tawada, M GP IEEE TI Simulations and experiments of beam-beam effects in e(+)e(-) storage rings SO 2005 IEEE PARTICLE ACCELERATOR CONFERENCE (PAC), VOLS 1-4 SE IEEE Particle Accelerator Conference LA English DT Proceedings Paper CT 21st Particle Accelerator Conference (PAC) CY MAY 16-20, 2005 CL Knoxville, TN SP IEEE ID ELECTRON-POSITRON COLLIDERS AB Over the past decade, extensive simulations of beam-beam effects in e(+)e(-) colliders, based on the particle-in-cell (PIC) method, were developed to explain many complex experimental observations. Recently, such simulations were used to predict the future luminosity performance of e(+)e(-) colliders. Some predictions have been proven to be correct in the existing accelerators. In this paper, many effects such as the beam-beam limit, crossing angle, parasitic collisions, betatron spectrum, and the beam-beam lifetime, will be directly compared between simulations and experiments. C1 SLAC, Menlo Pk, CA 94025 USA. RP Cai, Y (reprint author), SLAC, Menlo Pk, CA 94025 USA. EM yunhai@slac.stanford.edu NR 8 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-8859-3 J9 IEEE PART ACC CONF PY 2005 BP 675 EP 679 PG 5 WC Instruments & Instrumentation; Physics, Particles & Fields SC Instruments & Instrumentation; Physics GA BDV94 UT WOS:000235745200214 ER EF